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... is used to treat certain infections caused by bacteria, such as bronchitis; gonorrhea; Lyme disease; and infections ... antibiotics. It works by stopping the growth of bacteria. Antibiotics will not work for colds, flu, or ...
Pharmacokinetics of cefuroxime in infants and children with bacterial meningitis.
del Rio, M de los A; Chrane, D F; Shelton, S; McCracken, G H; Nelson, J D
A total of 38 patients with bacterial meningitis received either 50 or 75 mg of cefuroxime per kg of body weight given as a 15-min intravenous infusion during the first to third days of therapy. The mean peak plasma concentrations of cefuroxime after doses of 50 and 75 mg/kg were 105 and 152 micrograms/ml, respectively. In five patients, pharmacokinetic values were determined after multiple doses of 50 mg of cefuroxime per kg every 6 h. The mean peak plasma concentrations were 120 micrograms/ml after the first dose and 130 micrograms/ml after the last dose. The concentrations at 6 h were 3.25 and 11.0 micrograms/ml after the first and last doses, respectively. The elimination half-life was approximately 1.5 h, and the apparent volume of distribution was 650 ml/kg. The plasma clearance rate was 195 to 198 ml/min per 1.73 m2. Penetration into the cerebrospinal fluid, expressed as the ratio of the cerebrospinal fluid to serum areas under the curve times 100, was 6.4% in patients given 50 mg of cefuroxime per kg and 10% in those who received 75 mg/kg. The cerebrospinal bactericidal activity in 27 patients was less than or equal to 1:8; only 2 patients had bactericidal activity of less than or equal to 1:2. PMID:7159072
Role of liquid membrane phenomenon in the anti-bacterial activity of Cefuroxime Sodium
Nagesh, C.; Shankaraiah, M. M.; Venkatesh, J. S.; Setty, S. Ramachandra
The role of liquid membrane phenomenon has been studied in the anti bacterial activity of cephalosporins i.e. Cefuroxime sodium. In our earlier publication [1] it was reported that hydraulic permeability data obtained to demonstrate the existence of liquid membrane in series with supporting membrane generated by Cefuroxime sodium. Transport of selected permeants (glucose, PABA, glycine, and ions like Mg++, NH4+, PO4-, Ca++, Na+, K+ and Cl-) through liquid membrane generated by Cefuroxime sodium in series with supporting membrane has been studied. The results indicated that the liquid membrane generated by Cefuroxime sodium inhibit the transport of various essential bio-molecules and permeants in to the cell. This modification in permeability of different permeants in the presence of the liquid membranes is likely to play significant role in the biological actions of Cefuroxime sodium. The anti-bacterial activity of Cefuroxime sodium further confirmed that the generation of liquid membrane by Cefuroxime sodium is also contributing for the antibacterial activity of them. PMID:24825969
Targeting cefuroxime plasma concentrations during coronary artery bypass graft surgery with cardiopulmonary bypass.
Aalbers, Marieke; Ter Horst, Peter G J; Hospes, Wobbe; Hijmering, Michel L; Spanjersberg, Alexander J
Backgound Patients are at risk for severe postoperative infections after coronary artery bypass graft (CABG) surgery. Clinical laboratory data showed that unbound plasma concentrations of cefuroxime were not always adequate, therefore we developed a new dosing regimen. Objective The aim of this prospective study is to evaluate the new dosing strategy by monitoring patients for unbound cefuroxime plasma concentrations during CABG surgery with cardiopulmonary bypass (CPB). Setting A Dutch teaching hospital. Methods In this prospective trial, patients scheduled for CABG surgery with CPB were included. A starting dose of 1500Āmg cefuroxime was given with anesthesia induction, followed by 750Āmg cefuroxime every hour until wound closure. In case of renal failure the dosing regimen was adapted. Serial blood samples were collected before, during and after the CPB process. Pharmacokinetic modelling was performed by using an 'iterative two-stage Bayesian population procedure'. Main outcome measure Unbound plasma concentrations of cefuroxime. Results 22 patients were included, data could be evaluated of 21 patients. In 24Ā% of the patients the unbound cefuroxime plasma concentration was below the target range during surgery before CPB started. Patients with a bodyweight above 100Ākg or age <60Āyears were more likely to have unbound plasma concentrations below the target range (PĀ=Ā0.030 and PĀ=Ā0.008). During CPB, the half-life of unbound cefuroxime increased by 17Ā% and the clearance decreased by 11Ā% compared to before CPB (PĀ=Ā0.033 and PĀ=Ā0.014). The mean pharmacokinetic parameters before, during and after CPB were as follows: elimination half-life 72, 84 and 76Āmin; clearance of unbound cefuroxime (Clu) 14.2, 12.7, 13.8Āl/h and volume of distribution (Vu) 0.280, 0.284 and 0.290Āl/kg respectively. Variations in unbound fractions before, during and after CPB were below 2Ā%, implicating the unbound fraction of cefuroxime is not influenced by CPB. Conclusion Our results show that CPB during CABG surgery does not lead to inadequate unbound cefuroxime concentrations. Age, renal function and possibly also weight are more important factors that can result in unbound plasma cefuroxime concentrations below the target value. PMID:25791346
Improvement in Dissolution Rate of Cefuroxime Axetil by using Poloxamer 188 and Neusilin US2.
Sruti, J; Patra, Ch N; Swain, S K; Beg, S; Palatasingh, H R; Dinda, S C; Rao, M E Bhanoji
A combination of fusion and surface adsorption techniques was used to enhance the dissolution rate of cefuroxime axetil. Solid dispersions of cefuroxime axetil were prepared by two methods, namely fusion method using poloxamer 188 alone and combination of poloxamer 188 and Neusilin US2 by fusion and surface adsorption method. Solid dispersions were evaluated for solubility, phase solubility, flowability, compressibility, Kawakita analysis, Fourier transform-infrared spectra, differential scanning calorimetry, powder X-ray diffraction study, in vitro drug release, and stability study. Solubility studies showed 12- and 14-fold increase in solubility for solid dispersions by fusion method, and fusion and surface adsorption method, respectively. Phase solubility studies showed negative ?G (0) tr values for poloxamer 188 at various concentrations (0, 0.25, 0.5, 0.75 and 1%) indicating spontaneous nature of solubilisation. Fourier transform-infrared spectra and differential scanning calorimetry spectra showed that drug and excipients are compatible with each other. Powder X-ray diffraction study studies indicated that presence of Neusilin US2 is less likely to promote the reversion of the amorphous cefuroxime axetil to crystalline state. in vitro dissolution studies, T50% and mean dissolution time have shown better dissolution rate for solid dispersions by fusion and surface adsorption method. Cefuroxime axetil release at 15 min (Q15) and DE15 exhibited 23- and 20-fold improvement in dissolution rate. The optimized solid dispersion formulation was stable for 6 months of stability study as per ICH guidelines. The stability was ascertained from drug content, in vitro dissolution, Fourier transform-infrared spectra and differential scanning calorimetry study. Hence, this combined approach of fusion and surface adsorption can be used successfully to improve the dissolution rate of poorly soluble biopharmaceutical classification system class II drug cefuroxime axetil. PMID:23901163
Improvement in Dissolution Rate of Cefuroxime Axetil by using Poloxamer 188 and Neusilin US2
Sruti, J.; Patra, Ch. N.; Swain, S. K.; Beg, S.; Palatasingh, H. R.; Dinda, S. C.; Rao, M. E. Bhanoji
A combination of fusion and surface adsorption techniques was used to enhance the dissolution rate of cefuroxime axetil. Solid dispersions of cefuroxime axetil were prepared by two methods, namely fusion method using poloxamer 188 alone and combination of poloxamer 188 and Neusilin US2 by fusion and surface adsorption method. Solid dispersions were evaluated for solubility, phase solubility, flowability, compressibility, Kawakita analysis, Fourier transform-infrared spectra, differential scanning calorimetry, powder X-ray diffraction study, in vitro drug release, and stability study. Solubility studies showed 12- and 14-fold increase in solubility for solid dispersions by fusion method, and fusion and surface adsorption method, respectively. Phase solubility studies showed negative ?G0tr values for poloxamer 188 at various concentrations (0, 0.25, 0.5, 0.75 and 1%) indicating spontaneous nature of solubilisation. Fourier transform-infrared spectra and differential scanning calorimetry spectra showed that drug and excipients are compatible with each other. Powder X-ray diffraction study studies indicated that presence of Neusilin US2 is less likely to promote the reversion of the amorphous cefuroxime axetil to crystalline state. in vitro dissolution studies, T50% and mean dissolution time have shown better dissolution rate for solid dispersions by fusion and surface adsorption method. Cefuroxime axetil release at 15 min (Q15) and DE15 exhibited 23- and 20-fold improvement in dissolution rate. The optimized solid dispersion formulation was stable for 6 months of stability study as per ICH guidelines. The stability was ascertained from drug content, in vitro dissolution, Fourier transform-infrared spectra and differential scanning calorimetry study. Hence, this combined approach of fusion and surface adsorption can be used successfully to improve the dissolution rate of poorly soluble biopharmaceutical classification system class II drug cefuroxime axetil. PMID:23901163
[Cefuroxime axetil, a new oral cephalosporin for treating infections of the ORL field: clinical synthesis].
Westphal, J F
Cefuroxime axetil (C.A.E.) is a broad spectrum cephalosporin, suitable for oral route. Its antibacterial activity includes all the pathogens usually responsible for E.N.T. infection, with low M.I.C.'s: H. influenzae, S. pneumoniae, S. aureus, S. pyogene. The stability of the drug against betalactamases, especially those produced by H. influenzae, associated with good bio availability (50%) and tissue penetration (30%) account for the potent in vivo bactericidal activity and clinical efficacy of cefuroxime axetil. More than 1,000 patients had been enrolled in controlled clinical trials: the success rates yielded by C.A.E. were 98%, 96% and 91%, respectively for pharingitis/tonsilitis, otitis media and acute sinusitis. C.A.E. is at least as effective as amoxycillin/clavulanic acid and safety appears to be better. PMID:2087617
Assay of Diastereoisomers of Cefuroxime Axetil in Amorphous and Crystalline Forms Using UHPLC-DAD.
Garbacki, Piotr; Te?yk, Artur; Zalewski, Przemys?aw; Jeli?ska, Anna; Paczkowska, Magdalena; Talczy?ska, Alicja; Oszczapowicz, Irena; Cielecka-Piontek, Judyta
A sensitive UHPLC-DAD method was developed for determination of diastereoisomers of cefuroxime axetil in bulk substance in amorphous and crystalline forms as well as in pharmaceutical preparations. Chromatographic separation was achieved on Kinetex C-18 (100ĀmmĀūĀ2.1Āmm, 1.7ĀĄm) column with mobile phase consisting of 0.1Ā% formic acid:methanol (88:12, v/v), at the flow rate of 0.7ĀmLĀmin(-1) and total run time of 3Āmin. The wavelength of the DAD detector was set at 278Ānm. Inter-day precision (RSD) was less than 3Ā% and accuracy level ranged between 98.31 and 104.99Ā%. Degradation products of cefuroxime axetil in aqueous solutions and in the solid state were identified with a EIS-Q-MS mass spectrometer. The solubility of above-mentioned polymorphic forms of cefuroxime axetil in suitable solvents is a crucial factor during preparation of samples and is essential for chromatographic separation of its diastereoisomers. PMID:25400288
Comparison of moxifloxacin and cefuroxime axetil in the treatment of acute maxillary sinusitis. Sinusitis Infection Study Group.
Burke, T; Villanueva, C; Mariano, H; Huck, W; Orchard, D; Haverstock, D; Heyd, A; Church, D
The aim of this prospective, multicenter, randomized, double-masked clinical trial was to compare the efficacy and safety of moxifloxacin with those of cefuroxime axetil for the treatment of community-acquired acute sinusitis. Five hundred forty-two adult patients with symptoms and radiographic evidence of acute maxillary sinusitis received a 10-day oral regimen of either moxifloxacin (400 mg once daily) or cefuroxime axetil (250 mg twice daily). Acute signs and symptoms at presentation had lasted >7 days but <4 weeks. Clinical response at the end of therapy (7 to 14 days after treatment) was the primary efficacy variable. Four hundred fifty-seven of the patients (223 moxifloxacin, 234 cefuroxime axetil) were included in the clinical efficacy analysis. Moxifloxacin was found to be similar in effectiveness to cefuroxime axetil at the end-of-therapy visit (90% vs. 89%, respectively; 95% confidence interval, -5.1% to 6.2%). Clinical relapse at the follow-up visit was reported for only 8 patients (3 moxifloxacin, 5 cefuroxime axetil). No clinically significant differences were observed with respect to the number of patients experiencing a successful clinical response based on demographic or infection characteristics. Five of the 542 enrolled patients were lost to follow-up. Of the 537 patients in the intent-to-treat population, drug-related adverse events were reported in 37% of moxifloxacin-treated patients and in 26% of cefuroxime axetil-treated patients (P = 0.006). Adverse-event profiles were comparable in the 2 treatment groups, with the exception of nausea, which was reported by 11% of moxifloxacin-treated patients compared with 4% of cef uroxime axetil-treated patients (P = 0.003). In this study, moxifloxacin was as effective as cefuroxime axetil in the treatment of community-acquired acute sinusitis. PMID:10566563
Bioequivalence evaluation of two brands of cefuroxime 500 mg tablets (Cefuzime? and Zinnat?) in healthy human volunteers
Mansour S. Al-Said; Khalil I. Al-Khamis; Esmail M. Niazy; Yousry M. El-Sayed; Khalid A. Al-Rashood; Sulaiman Al-Bella; Mohd A Al-Yamani; Tawfeeq A Al-Najjar; Syed M Alam; Ruwayda Dham; Q Zaman Qumaruzaman
A bioequivalence study of two oral formulations of 500 mg cefuroxime axetil was carried out in 24 healthy volunteers following a single dose, standard two-treatment cross-over design at the College of Pharmacy, King Saud University, Riyadh, Saudi Arabia, working jointly with King Khalid University Hospital. The two formulations used were Cefuzime« (Julphar, United Arab Emirates) as the test and Zinnat«
Prospective randomized comparison of cefodizime versus cefuroxime for perioperative prophylaxis in patients undergoing coronary artery bypass grafting.
Wenisch, C; Bartunek, A; Zedtwitz-Liebenstein, K; Hiesmayr, M; Parschalk, B; Pernerstorfer, T; Graninger, W
The effects of cefodizime and cefuroxime on neutrophil phagocytosis and reactive oxygen production in 54 patients undergoing elective coronary artery bypass grafting were studied. Both drugs were administered twice at a dosage of 40 mg/kg of body weight (pre- and intraoperative). Phagocytic capacity was assessed by measuring the uptake of fluorescein isothiocyanate-labeled Escherichia coli and Staphylococcus aureus by flow cytometry. Reactive oxygen generation after phagocytosis was estimated by determining the amount of dihydrorhodamine 123 converted to rhodamine 123 intracellularly. In both groups the mean phagocytic ability for E. coli and S. aureus decreased during surgery (-21 and -8%, respectively, for the cefodizime group and -39 and -38%, respectively, for the cefuroxime group; P < 0.05 for all). In the cefodizime group a normalization of mean E. coli and S. aureus neutrophil phagocytosis was seen on day 5 (+9 and -4% compared to preoperative values; P > 0.35 for both), whereas in cefuroxime-treated patients phagocytic ability remained depressed (-37 and -31%; P < 0.04 for both). In both groups mean neutrophil reactive oxygen intermediate (ROI) production after E. coli and S. aureus phagocytosis increased during cardiopulmonary bypass (+44 and +83%, respectively, in the cefodizime group and +58 and +73%, respectively, in the cefuroxime group; P < 0.05 for all). One day after surgery E. coli- and S. aureus-driven neutrophil ROI production was not different from the preoperative values (-2 and +12%, respectively, for the cefodizime group and +7 and +15%, respectively, for the cefuroxime group; P > 0.15 for all). Postoperative serum levels of the C-reactive protein on days 2 and 7 were lower in cefodizime-treated patients (19 +/- 6 and 4 +/- 2 mg/liter versus 23 +/- 6 and 11 +/- 5 mg/liter; P < 0.05 for both). In addition to cefodizime's antimicrobial activity during perioperative prophylaxis, its use in coronary artery bypass grafting can prevent procedure-related prolonged postoperative neutrophil phagocytosis impairment. PMID:9210690
Simple and Robust Analysis of Cefuroxime in Human Plasma by LC-MS/MS: Application to a Bioequivalence Study.
Hu, Xingjiang; Huang, Mingzhu; Liu, Jian; Chen, Junchun; Shentu, Jianzhong
A simple, robust LC-MS/MS assay for quantifying cefuroxime in human plasma was developed. Cefuroxime and tazobactam, as internal standard (IS), were extracted from human plasma by methanol to precipitate protein. Separation was achieved on a Zorbax SB-Aq (4.6 ū 250?mm, 5? ? m) column under isocratic conditions. The calibration curve was linear in the concentration range of 0.0525-21.0? ? g/mL (r = 0.9998). The accuracy was higher than 90.92%, while the intra- and interday precision were less than 6.26%. The extraction procedure provides recovery ranged from 89.44% to 92.32%, for both analyte and IS. Finally, the method was successfully applied to a bioequivalence study of a single 500?mg dose of cefuroxime axetil in 22 healthy Chinese male subjects under fasting condition. Bioequivalence was determined by calculating 90% Cls for the ratios of C max, AUC0-t , and AUC0-? values for the test and reference products, using logarithmic transformed data. The 90% Cls for the ratios of C max (91.4%~104.2%), AUC0-t (97.4%~110.9%), and AUC0-? (97.6%~111.1%) values were within the predetermined range. It was concluded that the two formulations (test for capsule, reference for tablet) analyzed were bioequivalent in terms of rate and extent of absorption and the method met the principle of quick and easy clinical analysis. PMID:24864138
Removal of amoxicillin and cefuroxime axetil by advanced membranes technology, activated carbon and micelle-clay complex.
Awwad, Mohammad; Al-Rimawi, Fuad; Dajani, Khuloud Jamal Khayyat; Khamis, Mustafa; Nir, Shlomo; Karaman, Rafik
Two antibacterials, amoxicillin trihydrate and cefuroxime axetil spiked into wastewater were completely removed by sequential wastewater treatment plant's membranes, which included activated sludge, ultrafiltration (hollow fibre and spiral wound membranes with 100 and 20?kDa cut-offs), activated carbon column and reverse osmosis. Adsorption isotherms in synthetic water which employed activated carbon and micelle-clay complex (octadecyltrimethylammonium-montmorillonite) as adsorbents fitted the Langmuir equation. Qmax of 100 and 90.9?mg?g(-1), and K values of 0.158 and 0.229?L?mg(-1) were obtained for amoxicillin trihydrate using activated carbon and micelle-clay complex, respectively. Filtration of antibacterials in the ppm range, which yielded variable degrees of removal depending on the volumes passed and flow rates, was simulated and capacities for the ppb range were estimated. Stability study in pure water and wastewater revealed that amoxicillin was totally stable for one month when kept at 37░C, whereas cefuroxime axetil underwent slow hydrolysis to cefuroxime. PMID:25686519
Development and Validation of a Rapid Turbidimetric Assay to Determine the Potency of Cefuroxime Sodium in Powder for Injection
Vieira, Daniela C. M.; Fiuza, Thalita F. M.; Salgado, Hķrida R.N.
The cefuroxime sodium is a second generation cephalosporin indicated for infections caused by Gram-positive and Gram-negative microorganisms. Although this drug is highly studied and researched regarding the antimicrobial activity, pharmacokinetics and pharmacodynamics, there are few studies regarding the development of analytical methodology for this cephalosporin. Thus, research involving analytical methods is essential and highly relevant to optimize its analysis in the pharmaceutical industry and guarantee the quality of the product already sold. This study describes the development and validation of a microbiological assay applying the turbidimetric method for the determination of cefuroxime, using Micrococcus luteus ATCC 9341 as micro-organism test and 3x3 parallel line assay design, with nine tubes for each assay, as recommended by the Brazilian Pharmacopoeia. The developed and validated method showed excellent results of linearity, seletivity, precision and robustness, in the concentration range from 30.0 to 120.0 mg/mL, with 100.21% accuracy and content 99.97% to cefuroxime sodium in injectable pharmaceutical form. PMID:25438016
Cefuroxime axetil loaded solid lipid nanoparticles for enhanced activity against S. aureus biofilm.
Singh, Bhupender; Vuddanda, Parameswara Rao; M R, Vijayakumar; Kumar, Vinod; Saxena, Preeti S; Singh, Sanjay
The present research work is focused on the development of solid lipid nanoparticles of cefuroxime axetil (CA-SLN) for its enhanced inhibitory activity against Staphylococcus aureus produced biofilm. CA-SLN was prepared by solvent emulsification/evaporation method using single lipid (stearic acid (SA)) and binary lipids (SA and tristearin (TS)). Process variables such as volume of dispersion medium, concentration of surfactant, homogenization speed and time were optimized. The prepared SLN were characterized for encapsulation efficiency, drug polymer interaction studies (DSC and FT-IR), shape and surface morphology (SEM and AFM), in vitro drug release, stability studies and in vitro anti biofilm activity against S. aureus biofilm. Among the process variables, increased volume of dispersion medium, homogenization speed and time led to increase in particle size whereas increase in surfactant concentration decreased the particle size. SLN prepared using binary lipids exhibited higher entrapment efficiency than the single lipid. DSC and FT-IR studies showed no incompatible interaction between drug and excipients. CA-SLN showed two folds higher anti-biofilm activity in vitro than pristine CA against S. aureus biofilm. PMID:24945607
Enhancement in photocatalytic activity of NiO by supporting onto an Iranian clinoptilolite nano-particles of aqueous solution of cefuroxime pharmaceutical capsule
NASA Astrophysics Data System (ADS)
Pourtaheri, Asieh; Nezamzadeh-Ejhieh, Alireza
NiO/nano-clinoptilolite (NiO-NCP) was prepared by ion exchanging process of the prepared ball-mill nano-clinoptilolite particles with nickel(II) chloride aqueous solution. The prepared composite was characterized by XRD, UV-Vis DRS, TEM and FT-IR and then used as a catalyst in the photodegradation of cefuroxime (CF) using Hg lamp. The best experimental parameters were obtained as: 0.025 g L-1 of the photocatalyst containing 13.3% NiO, 50 times diluted cefuroxime solution at pH 5. The degradation extent was monitored by UV-Vis spectroscopy and the results were confirmed by HPLC and COD. The kinetics of the photodegradation process obeyed the Langmuir-Hinshelwood model.
Molecular Dynamics Simulation of the Complex PBP-2x with Drug Cefuroxime to Explore the Drug Resistance Mechanism of Streptococcus suis R61
Xia, Yingjie; Yang, Ming; Xiao, Jingfa; Yu, Jun
Drug resistance of Streptococcus suis strains is a worldwide problem for both humans and pigs. Previous studies have noted that penicillin-binding protein (PBPs) mutation is one important cause of ?-lactam antibiotic resistance. In this study, we used the molecular dynamics (MD) method to study the interaction differences between cefuroxime (CES) and PBP2x within two newly sequenced Streptococcus suis: drug-sensitive strain A7, and drug-resistant strain R61. The MM-PBSA results proved that the drug bound much more tightly to PBP2x in A7 (PBP2x-A7) than to PBP2x in R61 (PBP2x-R61). This is consistent with the evidently different resistances of the two strains to cefuroxime. Hydrogen bond analysis indicated that PBP2x-A7 preferred to bind to cefuroxime rather than to PBP2x-R61. Three stable hydrogen bonds were formed by the drug and PBP2x-A7, while only one unstable bond existed between the drug and PBP2x-R61. Further, we found that the Gln569, Tyr594, and Gly596 residues were the key mutant residues contributing directly to the different binding by pair wise energy decomposition comparison. By investigating the binding mode of the drug, we found that mutant residues Ala320, Gln553, and Thr595 indirectly affected the final phenomenon by topological conformation alteration. Above all, our results revealed some details about the specific interaction between the two PBP2x proteins and the drug cefuroxime. To some degree, this explained the drug resistance mechanism of Streptococcus suis and as a result could be helpful for further drug design or improvement. PMID:22563422
Determination of cefuroxime lysine in rat brain microdialysates by ultra-fast liquid chromatography with UV and tandem mass spectrometry: application to an acute toxicokinetic study.
Zhao, Longshan; Li, Qing; Zhu, Heyun; Chen, Xiaohui; Bi, Kaishun
Cefuroxime lysine is a new second-generation cephalosporins, which can penetrate the blood-brain barrier to cure the meningitis. In order to investigate its acute toxicokinetic study after intraperitoneal injection of 675?mg/kg cefuroxime lysine, a sensitive and clean ultra-fast liquid chromatography-tandem mass spectrometry (UFLC-MS/MS) method for the determination of cefuroxime lysine in microdialysate samples was developed and validated, which was compared with UFLC-UV as a reference method. Chromatographic separation was performed on a Shim-pack XR-ODS C18 column (75?ū?3.0?mm, 2.2?Ąm), with an isocratic elution of 0.1% formic acid in acetonitrile-0.1% formic acid in water (45:55, v/v) for LC-MS and acetonitrile-20?mm potassium dihydrogen phosphate (pH?3.0,20:80, v/v) for LC-UV. The lower limit of detection was 0.01?Ąg/mL for LC-MS and 0.1?Ąg/mL for LC-UV method, with the same corresponding linearity range of 0.1-50?Ąg/mL. The intra- and inter-day precisions (relative standard deviation) for both methods were from 1.1 to 8.9%, while the accuracy was all within ▒10.9%. The results of both methods were finally compared using paired t-test; the results indicated that the concentrations measured by the two methods correlated significantly (p?0.05), which suggested that the two methods based on LC-MS and LC-UV were suitable for the acute toxicokinetic study. PMID:24519907
Continuous versus Short-Term Infusion of Cefuroxime: Assessment of Concept Based on Plasma, Subcutaneous Tissue, and Bone Pharmacokinetics in an Animal Model
Bibby, Bo M.; Hardlei, Tore F.; Bue, Mats; Kerrn-Jespersen, Sigrid; Fuursted, Kurt; S°balle, Kjeld; Birke-S°rensen, Hanne
The relatively short half-lives of most ?-lactams suggest that continuous infusion of these time-dependent antimicrobials may be favorable compared to short-term infusion. Nevertheless, only limited solid-tissue pharmacokinetic data are available to support this theory. In this study, we randomly assigned 12 pigs to receive cefuroxime as either a short-term or continuous infusion. Measurements of cefuroxime were obtained every 30 min in plasma, subcutaneous tissue, and bone. For the measurements in solid tissues, microdialysis was applied. A two-compartment population model was fitted separately to the drug concentration data for the different tissues using a nonlinear mixed-effects regression model. Estimates of the pharmacokinetic parameters and time with concentrations above the MIC were derived using Monte Carlo simulations. Except for subcutaneous tissue in the short-term infusion group, the tissue penetration was incomplete for all tissues. For short-term infusion, the tissue penetration ratios were 0.97 (95% confidence interval [CI], 0.67 to 1.39), 0.61 (95% CI, 0.51 to 0.73), and 0.45 (95% CI, 0.36 to 0.56) for subcutaneous tissue, cancellous bone, and cortical bone, respectively. For continuous infusion, they were 0.53 (95% CI, 0.33 to 0.84), 0.38 (95% CI, 0.23 to 0.57), and 0.27 (95% CI, 0.13 to 0.48) for the same tissues, respectively. The absolute areas under the concentration-time curve were also lower in the continuous infusion group. Nevertheless, a significantly longer time with concentrations above the MIC was found for continuous infusion up until MICs of 4, 2, 2, and 0.5 ?g/ml for plasma and the same three tissues mentioned above, respectively. For drugs with a short half-life, like cefuroxime, continuous infusion seems to be favorable compared to short-term infusion; however, incomplete tissue penetration and high MIC strains may jeopardize the continuous infusion approach. PMID:25313214
In vitro activities of streptomycin and 11 oral antimicrobial agents against clinical isolates of Klebsiella rhinoscleromatis.
Perkins, B A; Hamill, R J; Musher, D M; O'Hara, C
We tested in vitro the activities of streptomycin and tetracycline--antibiotics that have long been used to treat rhinoscleroma--as well as several newer oral agents by using 23 isolates of the causative organism Klebsiella rhinoscleromatis. All isolates were inhibited by clinically achievable concentrations of trimethoprim-sulfamethoxazole, amoxicillin-clavulanate, chloramphenicol, ciprofloxacin, cephalexin, cefuroxime, and cefpodoxime. PMID:1416867
Beta-lactam antibiotics modulate T-cell functions and gene expression via covalent binding to cellular albumin
Mor, Felix; Cohen, Irun R.
Recent work has suggested that beta-lactam antibiotics might directly affect eukaryotic cellular functions. Here, we studied the effects of commonly used beta-lactam antibiotics on rodent and human T cells in vitro and in vivo on T-cell¢mediated experimental autoimmune diseases. We now report that experimental autoimmune encephalomyelitis and adjuvant arthritis were significantly more severe in rats treated with cefuroxime and other beta-lactams. T cells appeared to mediate the effect: an anti-myelin basic protein T-cell line treated with cefuroxime or penicillin was more encephalitogenic in adoptive transfer experiments. The beta-lactam ampicillin, in contrast to cefuroxime and penicillin, did not enhance encephalomyelitis, but did inhibit the autoimmune diabetes developing spontaneously in nonobese diabetic mice. Gene expression analysis of human peripheral blood T cells showed that numerous genes associated with T helper 2 (Th2) and T regulatory (Treg) differentiation were down-regulated in T cells stimulated in the presence of cefuroxime; these genes were up-regulated in the presence of ampicillin. The T-cell protein that covalently bound beta-lactam antibiotics was found to be albumin. Human and rodent T cells expressed albumin mRNA and protein, and penicillin-modified albumin was taken up by rat T cells, leading to enhanced encephalitogenicity. Thus, beta-lactam antibiotics in wide clinical use have marked effects on T-cell behavior; beta-lactam antibiotics can function as immunomodulators, apparently through covalent binding to albumin. PMID:23382225
Extended spectrum beta-lactamase production and fluorquinolone resistance in pathogens associated with community acquired urinary tract infection
Martin Cormican; Dearbhaile Morris; Geraldine Corbett-Feeeney; John Flynn
We have evaluated the susceptibility of 199 pathogens isolated in pure culture from consecutive urine samples submitted from the community. Rates of susceptibility for all organisms were ampicillin, 48%; amoxycillin\\/clavulanic acid, 88%; cephalothin, 57%; cefuroxime axetil, 74%; nalidixic acid, 85%; ciprofloxacin, 99%; nitrofurantoin, 78%; and trimethoprim, 67%. Ciprofloxacin resistance and production of extended spectrum ?-lactamase enzymes were detected in Escherichia
Environmental assessment of Norwegian priority pharmaceuticals based on the EMEA guideline
Merete Grung; Torsten Kõllqvist; Solveig Sakshaug; Svetlana Skurtveit; Kevin V. Thomas
An environmental risk assessment of eleven pharmaceuticals according to the guideline recommended by the European Medicines Evaluation Agency (EMEA) was performed. Cefuroxime, ciprofloxacin, cyclophosphamide, diclofenac, ethinylestradiol, ibuprofen, metoprolol, paracetamol, sulfamethoxazole, tetracycline and trimethoprim were selected for assessment by the Norwegian Pollution Control Authority. Predicted environmental concentrations (PECs) were calculated according to both the EMEA guideline and a conventional model for
Study of the in vitro activity of amoxicillin/clavulanic acid and other beta-lactam antibiotics against Escherichia coli isolated from urine specimens.
Vanhoof, R; Carpentier, M; Delannoy, P; Fagnart, O; Lontie, M; Mans, I; Nyssen, H J; Van Nimmen, L
A total of 205 serial, unduplicated urinary isolates of Escherichia coli was collected from June through August 1998 in 2 community and 3 hospital laboratories. By using the NCCLS broth microdilution technique, their in vitro susceptibility to ampicillin, amoxicillin/clavulanic acid, cefuroxime, cefuroxime axetil, ticarcillin/clavulanic acid and piperacillin/tazobactam was determined. One hundred and twenty isolates were from hospitalised patients, 85 from ambulatory, 129 community acquired and 76 nosocomial. Half of the nosocomial isolates were obtained from naturally produced and half from alternatively produced urine specimens. In general, the highest susceptibility rates, following NCCLS criteria, were found for piperacillin/tazobactam (93.2%) followed by cefuroxime (92.2%) and amoxicillin/clavulanic acid (82.9%). Ampicillin showed a clear bimodal distribution with a clear peak for the resistant population. The highest degree of ampicillin resistance was found in nosocomial isolates. Overall, ampicillin showed the lowest degree of susceptibility. Most of the ampicillin resistant isolates remained susceptible to piperacillin/tazobactam, cefuroxime and amoxicillin/clavulanic acid. In general, the community acquired isolates had higher susceptibility rates than the nosocomial isolates. PMID:11307481
Clinical Efficacy of Intravenous followed by Oral Azithromycin Monotherapy in Hospitalized Patients with Community-Acquired Pneumonia
Plouffe, Joseph; Schwartz, Douglas B.; Kolokathis, Antonia; Sherman, Bruce W.; Arnow, Paul M.; Gezon, John A.; Suh, Byungse; Anzuetto, Antonio; Greenberg, Richard N.; Niederman, Michael; Paladino, Joseph A.; Ramirez, Julio A.; Inverso, Jill; Knirsch, Charles A.
The purpose of this study was to evaluate intravenous (i.v.) azithromycin followed by oral azithromycin as a monotherapeutic regimen for community-acquired pneumonia (CAP). Two trials of i.v. azithromycin used as initial monotherapy in hospitalized CAP patients are summarized. Clinical efficacy is reported from an open-label randomized trial of azithromycin compared to cefuroxime with or without erythromycin. Bacteriologic and clinical efficacy results are also presented from a noncomparative trial of i.v. azithromycin that was designed to give additional clinical experience with a larger number of pathogens. Azithromycin was administered to 414 patients: 202 and 212 in the comparative and noncomparative trials, respectively. The comparator regimen was used as treatment for 201 patients; 105 were treated with cefuroxime alone and 96 were given cefuroxime plus erythromycin. In the comparative trial, clinical outcome data were available for 268 evaluable patients with confirmed CAP at the 10- to 14-day visit, with 106 (77%) of the azithromycin patients cured or improved and 97 (74%) of the comparator patients cured or improved. Mean i.v. treatment duration and mean total treatment duration (i.v. and oral) for the clinically evaluable patients were significantly (P < 0.05) shorter for the azithromycin group (3.6 days for the i.v. group and 8.6 days for the i.v. and oral group) than for the evaluable patients given cefuroxime plus erythromycin (4.0 days for the i.v. group and 10.3 days for the i.v. and oral group). The present comparative study demonstrates that initial therapy with i.v. azithromycin for hospitalized patients with CAP is associated with fewer side effects and is equal in efficacy to a 1993 American Thoracic Society-suggested regimen of cefuroxime plus erythromycin when the erythromycin is deemed necessary by clinicians. PMID:10858333
Susceptibility-resistance profile of micro-organisms isolated from herbal medicine products sold in Nigeria
ceporex (cephalexin) 80%, cefuroxime 100%), chloramphenicol (66.7%), nitrofurantoin (100%) and cotrimoxazole (93.3%). Most of the fungal isolates were resistant to griseofulvin (67.3%) but susceptible to nystatin (73.1%), ketoconazole (98.1%), tioconazole (100%), clotrimazole (78.9%) and miconazole (88.5%). A significant proportion of bacteria and fungi isolated from these HMPs demonstrated resistance to conventional antibiotics. The present study therefore reveals that HMPs may
Sequence of the 68,869 bp IncP-1? plasmid pTB11 from a waste-water treatment plant reveals a highly conserved backbone, a Tn 402-like integron and other transposable elements
Thomas Tennstedt; Rafael Szczepanowski; Irene Krahn; Alfred P³hler; Andreas Schl³ter
To analyse the significance of conjugative broad-host-range IncP-1? plasmids for the spread of antibiotic resistance determinants in waste-water treatment plants we isolated and characterised five different IncP-1? plasmids from bacteria of activated sludge and the final effluents of a municipal waste-water treatment plant. These plasmids mediate resistance to ampicillin, cefaclor, cefuroxime, gentamicin, kanamycin, spectinomycin, streptomycin, tetracycline, tobramycin, and trimethoprim. The
A randomised, multicentre study of ceftriaxone versus standard therapy in the treatment of lower respiratory tract infections
G. J. de Klerk; J. H. M. van Steijn; S. Lobatto; C. A. J. J. Jaspers; W. C. J. van Veldhuizen; C. A. J. Hensing; M. C. M. Bunnik; W. H. Geraedts; A. S. M. Dofferhof; J. Van Den Berg; J. H. J. M. Melis; A. I. M. Hoepelman
In this study the efficacy and cost-effectiveness of i.v. ceftriaxone 1 g once daily (CTX) was compared with standard i.v. antibiotic treatment (STD) for lower respiratory tract infections (LRTI). STD was given according to the guidelines of the American Thoracic Society and consisted of either cefuroxime 1500 mg three times daily (q8h), amoxicillin\\/clavulanic acid 1200 mg q8h or ceftriaxone 2
evaluation of Eigh different Cephalosporins for Detection of Cephalosporin Resistance in Salmonella enterica and Escherichia coli
Frank M. Aarestrup; Henrik Hasman; Kees Veldman; Dik Mevius
This study evaluates the efficacy of eight different cephalosporins for detection of cephalosporin resistance mediated by extended spectrum beta-lactamases (ESBL) and plasmidic AmpC beta-lactamases in Salmonella and Escherichia coli. A total of 138 E. coli and 86 Salmonella isolates with known beta-lactamase genes were tested for susceptibility toward cefoperazone, cefotaxime, cefpodoxime, cefquinome, ceftazidime, ceftiofur, ceftriaxone, and cefuroxime using minimum inhibitory
Bacterial contaminants and antibiotic prophylaxis in total hip arthroplasty.
Al-Maiyah, M; Hill, D; Bajwa, A; Slater, S; Patil, P; Port, A; Gregg, P J
We have investigated the contaminating bacteria in primary hip arthroplasty and their sensitivity to the prophylactic antibiotics currently in use. Impressions (627) of the gloved hands of the surgical team in 50 total hip arthroplasties were obtained on blood agar. The gloves were changed after draping, at intervals of 20 minutes thereafter, and before using cement. Changes were also undertaken whenever a visible puncture was detected. The culture plates were incubated at 37 degrees C for 48 hours. Isolates were identified and tested for sensitivity to flucloxacillin, which is a recognised indicator of sensitivity to cefuroxime. They were also tested against other agents depending upon their appearance on Gram staining. We found contamination in 57 (9%) impressions and 106 bacterial isolates. Coagulase-negative staphylococci were seen most frequently (68.9%), but we also isolated Micrococcus (12.3%), diphtheroids (9.4%), Staphylococcus aureus (6.6%) and Escherichia coli (0.9%). Of the coagulase-negative staphylococci, only 52.1% were sensitive to flucloxacillin and therefore to cefuroxime. We believe that it is now appropriate to review the relevance of prophylaxis with cefuroxime and to consider the use of other agents. PMID:16129753
Resistance pattern of clinical isolates involved in surgical site infections.
Arsalan, Adeel; Naqvi, Syed Baqar-Shyum; Sabah, Arif; Bano, Rahila; Ali, Syed Imran
Wound infections due to the incursion of microbes need to be averted or to heal the wounds by antibiotics. Antibiotics are not only aid in cure of infections but also help to prevent the flourishing and production of one or more species of microorganism, resultant in purulent discharge. This current study was carried out to evaluate the resistance pattern of clinical isolates from surgical site infections by the Kirby Bauer disc diffusion method. A total of 257 clinical isolates were collected from different hospitals in Karachi and evaluated by using fifteen antibiotics belonging to different groups. Staphylococcus aureus (n=87), Escherichia coli (n=76), Pseudomonas aeruginosa (n=56), Proteus (n=21) and Klebsiella (n=17) species are the most common clinical isolates of surgical site infections. Among the semi-synthetic penicillins, ampicillin was found to be resistant to nearly all clinical isolates but amoxicillin was moderately sensitive to S. aureus. Combinations of semi-synthetic penicillins are more sensitive than the penicillin alone. Co-amoxiclave exhibits superior sensitivity to all the surgical infection isolates except Pseudomonas aeruginosa which showed 68.75% resistance. Pseudomonas aeruginosa was highly resistant to cephalosporin except ceftraixone which showed 21.88% resistance. S. aureus was slightly responsive to cefazolin, cephradine, cefaclor, ceftizoxime, cefuroxime and ceftriaxone. E. coli, Gram-negative clinical isolate was showed 25% and 31.25% resistance to ceftriaxone and cefuroxime. In the Klebsiella species, 71.42% and 64.29% resistance to cefazolin and cefuroxime respectively, was observed. Aminoglycosides such as gentamycin and tobramycin were found to be more susceptible to all the clinical isolates. Quinolones like ofloxacin and enoxacin were showed good sensitivity to nearly all the clinical isolates.On the basis of the present study, it is recommended to adopt a rational use of antibiotics in prophylaxis and the utilization of a coordinated scheme of surgical wound inspections. PMID:24374459
Novel water soluble neutral vanadium(IV)-antibiotic complex: Antioxidant, immunomodulatory and molecular docking studies.
Datta, Chitraniva; Das, Dharitri; Mondal, Paritosh; Chakraborty, Biswajit; Sengupta, Mahuya; Bhattacharjee, Chira R
A novel water soluble five coordinate oxovanadium(IV) complex, [VO(C16H15N4O8S)HSO4] incorporating cefuroxime, a cephalosporin group of antibiotic have been prepared from an interaction of vanadyl sulfate and cefuroxime in aqueous solution. The compound was characterized by Fourier transform infrared spectroscopy (FTIR), CHN microanalyses, ultraviolet-visible spectroscopy (UV-Vis), fast atom bombardment (FAB) mass spectrometry and thermogravimetric analysis (TGA). Density Functional Theory (DFT) computation using Gaussian 09 program at B3LYP level revealed a distorted square pyramidal energy optimized geometry for the vanadyl(IV) complex. The molecular docking studies show that the interaction between the vanadium complex and protein receptor, clathrin is dominated by hydrophobic forces. The experimental (1)H nuclear magnetic resonance (NMR) features of the analogous Zn(II) complex matched well with the theoretically computed values further affirming the distorted square pyramidal geometry for the vanadyl(IV) complex. Cyclic voltammetry revealed a metal centered single-electron oxidation-reduction response for VO(IV)/VO(V) couple. The antioxidant activity of the vanadium(IV)-complex vis-Ó-vis the antibiotic has been assessed by 1,1-diphenyl-2-picrylhydrazyl (DPPH) method. The vanadium complex showed comparatively better radical scavenging ability compared to the antibiotic cefuroxime. The antimicrobial activity of the compound has been assayed for five different microbial strains using minimum inhibitory concentration (MIC) method. Immunomodulatory studies carried out using phagocytosis index, myeloperoxidase release and cytokine assay indicated the vanadium(IV)-complex to be immunosuppressant. The cytotoxicity of the compound was evaluated by MTT (3-(4, 5-dimethyl thiazol-2-yl)-2, 5-diphenyl tetrazolium bromide) reduction assay. PMID:25982330
Surveillance of pneumococcal resistance in Belgium during winter 1996-1997.
Vanhoof, R; Carpentier, M; Glupczynski, Y; Gordts, B; Magerman, K; Mans, Y; Nyssen, H J; Simon, A; Surmont, I; Van De Vyvere, M; Van Landuyt, H; Van Nimmen, L; Van Noyen, R
This study tested 212 pneumococcal isolates from 9 institutions for their susceptibilities to penicillin, ampicillin, amoxycillin, amoxycillin/clavulanate, cefaclor, cefuroxime, cefotaxime, imipenem, tetracycline, erythromycin, and clarithromycin using NCCLS-standardized microdilution. Penicillin-insusceptibility was 12.3% [5.7% intermediate (0.12-1 microgram/ml) and 6.6% high-level (> or = 2 micrograms/ml)], tetracycline-insusceptibility (> or = 4 micrograms/ml) 31.1%, and erythromycin-insusceptibility (> or = 0.5 microgram/ml) 31.1% as well. Erythromycin-insusceptible isolates showed cross-insusceptibility to clarithromycin. Penicillin-susceptible isolates were susceptible to all beta-lactams. MICs of all beta-lactams rose with those of penicillin for penicillin-insusceptible isolates. Ampicillin and penicillin were equally potent against penicillin-insusceptible isolates, imipenem, cefotaxime, and amoxycillin +/- clavulanate were more potent (generally 5, 1, and 1 doubling dilution, respectively), and cefuroxime and cefaclor less potent (generally 1 and 6 doubling dilutions, respectively). Most penicillin-insusceptible isolates were high-level resistant to cefaclor (> or = 32 micrograms/ml). Although MICs of all beta-lactams rose with those of penicillin, resistance to penicillin was not absolute in terms of cross-resistance. Most penicillin-intermediate and high-level penicillin-resistant isolates remained fully susceptible and intermediate, respectively, to amoxycillin +/- clavulanate, cefotaxime, and imipenem, but not to cefuroxime. Penicillin-susceptible isolates were 76.9%, 42.3%, and 34.6% co-insusceptible to tetracycline, erythromycin, and tetracycline plus erythromycin, respectively. Most penicillin-, tetracycline-, and erythromycin-insusceptible isolates were of capsular types 23 > 6 > 19 > 32, 19 > 6 > 28 > 23, and 19 > 6 > 14 > 23, respectively. Compared to winter 1994-1995, insusceptibility to penicillin, tetracycline, and erythromycin rose by some 4%, 4%, and 13%, respectively. PMID:9795449
Impact of a Change in Antibiotic Prophylaxis on Total Antibiotic Use in a Surgical Intensive Care Unit
E. Meyer; F. Schwab; A. Pollitt; W. Bettolo; B. Schroeren-Boersch; M. Trautmann
\\u000a Abstract\\u000a \\u000a \\u000a Objective:\\u000a ĀĀThe aim of this study was to evaluate the impactof reducing the length of antibiotic prophylaxis for cerebrospinalshunts on\\u000a total antibiotic use and key resistantpathogens.\\u000a \\u000a \\u000a \\u000a \\u000a \\u000a Methods:\\u000a ĀĀIn January 2004, the use of antibiotic prophylaxiswas reduced to a single shot dose with cefuroxime in anintensive care unit\\u000a (ICU). Prior to this intervention, prophylaxiswith second-generation cephalosporins wasadministered during the entire
In vitro susceptibilities of 176 clinical isolates of Streptococcus pneumoniae to 11 beta-lactams, erythromycin, and tetracycline.
Vanhoof, R; Carpentier, M; Glupczynski, Y; Gordts, B; Magerman, K; Nyssen, H J; Simon, A; Surmont, I; Van de Vyvere, M; Van Landuyt, H; Van Nimmen, L; Van Noyen, R
One hundred seventy six consecutive, non-duplicate pneumococcal isolates from clinical specimens collected from November 1994 through February 1995 in nine general hospitals throughout Belgium were tested for their in vitro susceptibilities to penicillin, ampicillin, amoxycillin with and without clavulanate, cefaclor, cefuroxime, cefonicid, cefprozil, cefpodoxime, cefotaxime, imipenem, tetracycline, and erythromycin by means of the NCCLS microdilution test. The overall rate of decreased susceptibility to penicillin was 12.5%, including 6.3% of intermediately and 6.3% of fully resistant isolates. Penicillin, ampicillin amoxycillin, amoxycillin/clavulanate, cefuroxime, cefotaxime and imipenem had the highest activity on a weight basis (MIC50 < or = 0.008 microgram/ml), followed by cefpodoxime and erythromycin (MIC50 of 0.015 microgram/ml), cefprozil and tetracycline (MIC50 of 0.12 microgram/ml), and eventually, cefaclor and cefonicid (MIC50 of 0.5 microgram/ml). Aggregate rates of susceptible plus intermediately resistant isolates at NCCLS-recommended breakpoints, i.e. overall percentages of isolates likely to respond to increased antibiotic doses in vivo (except for meningitis), were 100.0% for imipenem and cefotaxime, 98.9% for amoxycillin with and without clavulanate, 93.8% for penicillin, and 90.9% for cefuroxime. Overall rates of susceptibility to erythromycin and tetracycline amounted to 78.4% and 72.7%, respectively. MIC values of all beta-lactams increased with those of penicillin. Ampicillin was equally active as penicillin against isolates with reduced susceptibility to the latter (MIC90 of 2 micrograms/ml); imipenem, cefotaxime, and amoxycillin with and without clavulanate however, were more active (MIC90 3, 1, and 1 doubling dilution, respectively, below that of penicillin), while cefpodoxime, cefuroxime, cefprozil, cefonicid, and cefaclor on the other hand, were less active (MIC90, 1, 1, 2, 5, and 5 doubling dilutions, respectively, above that of penicillin). In conclusion, the present data confirm that pneumococcal resistance to penicillin has increased in Belgium, suggest that resistance to erythromycin may have stabilised, and reveal an unexpectedly high rate of resistance to tetracycline. Imipenem was the most active antibiotic tested overall, and amoxycillin with or without clavulanate the most active oral antibiotic, with activity almost similar to that of cefotaxime. PMID:8997755
Activity of cefotiam in combination with beta-lactam antibiotics on enterobacterial hospital strains.
Vanhoof, R; Hubrechts, J M; Nyssen, H J; Nulens, E; Leger, J; de Schepper, N; Kupperberg, E; Couvreur, M L
By using checkerboard titrations the effect of cefotiam combined with different beta-lactam antibiotics on fifty strains of Enterobacteriaceae moderately susceptible (minimal inhibiting concentration greater than or equal to 8 mg/l) or resistant (minimal inhibiting concentration greater than or equal to 64 mg/l) to cefotiam was evaluated. The following compounds were tested: cefamandole, cefazolin, cefmenoxime, cefotaxime, cefotiam, ceftazidime, cefuroxime, mecillinam and piperacillin. The synergistic effect varied markedly. The combination cefotiam-mecillinam showed the highest rate of synergistic activity. Antagonism was found in 1% of the combinations. PMID:2371139
Antimicrobial Resistance of Salmonella enterica Isolates from Tonsil and Jejunum with Lymph Node Tissues of Slaughtered Swine in Metro Manila, Philippines
Ng, Kamela Charmaine S.; Rivera, Windell L.
Due to frequent antibiotic exposure, swine is now recognized as potential risk in disseminating drug-resistant Salmonella enterica strains. This study thus subjected 20 randomly selected S. enterica isolates from tonsil and jejunum with lymph node (JLN) tissues of swine slaughtered in Metro Manila, Philippines, to VITEK 2 antimicrobial susceptibility testing (AST). The test revealed all 20 isolates had resistance to at least one antimicrobial agent, in which highest occurrence of resistance was to amikacin (100%), cefazolin (100%), cefuroxime (100%), cefuroxime axetil (100%), cefoxitin (100%), and gentamicin (100%), followed by ampicillin (50%), and then by sulfamethoxazole trimethoprim (30%). Three multidrug-resistant (MDR) isolates were detected. The sole S. enterica serotype Enteritidis isolate showed resistance to 12 different antibiotics including ceftazidime, ceftriaxone, amikacin, gentamicin, and tigecycline. This study is the first to report worldwide on the novel resistance to tigecycline of MDR S. enterica serotype Enteritidis isolated from swine tonsil tissues. This finding poses huge therapeutic challenge since MDR S. enterica infections are associated with increased rate of hospitalization or death. Thus, continual regulation of antimicrobial use in food animals and prediction of resistant serotypes are crucial to limit the spread of MDR S. enterica isolates among hogs and humans. PMID:24724034
In vitro selective antibiotic concentrations of beta-lactams for penicillin-resistant Streptococcus pneumoniae populations.
Negri, M C; Morosini, M I; Loza, E; Baquero, F
Therapeutic regimens containing beta-lactam antibiotics are selecting penicillin-resistant Streptococcus pneumoniae populations all over the world. The selective pressure after 4 h of exposure to different concentrations of amoxicillin, cefixime, cefuroxime, and cefotaxime for low-level or high-level penicillin-resistant S. pneumoniae was evaluated in an in vitro model with mixed populations with penicillin susceptibilities of 0.015, 0.5, 1, and 2 micrograms/ml. The antibiotic concentration selecting for low-level resistance strongly reduced the susceptible population. Increasing antibiotic concentrations tended to decrease the total proportion of penicillin-resistant bacteria because of reduced numbers of the low-level-resistant population. The antibiotic concentration selecting for high-level resistance produced fewer resistant populations, but most of the organisms selected represented high-level resistance. In general, amoxicillin was a good selector for the low-level-resistant population and a poor selector for high-level resistance; cefuroxime and cefotaxime were poor selectors for low-level resistance and better selectors than amoxicillin for high-level penicillin resistance. Cefixime was the best selector of low-level penicillin resistance. When only resistant populations were mixed, the strains with high-level resistance were selected even at low antibiotic concentrations. Determination of the effects of selective antibiotic concentrations on mixed cultures of bacteria expressing different antibiotic resistance levels may help researchers to understand the ecology and epidemiology of penicillin-resistant S. pneumoniae populations. PMID:8141563
Ultrafast quantification of ?-lactam antibiotics in human plasma using UPLC-MS/MS.
Carlier, Mieke; Stove, Veronique; De Waele, Jan J; Verstraete, Alain G
There is an increasing interest in monitoring plasma concentrations of ?-lactam antibiotics. The objective of this work was to develop and validate a fast ultra-performance liquid chromatographic method with tandem mass spectrometric detection (UPLC-MS/MS) for simultaneous quantification of amoxicillin, cefuroxime, ceftazidime, meropenem and piperacillin with minimal turn around time. Sample clean-up included protein precipitation with acetonitrile containing 5 deuterated internal standards, and subsequent dilution of the supernatant with water after centrifugation. Runtime was only 2.5 min. Chromatographic separation was performed on a Waters Acquity UPLC system using a BEH C18 column (1.7 ?m, 100 mm ū 2.1 mm) applying a binary gradient elution of water and methanol both containing 0.1% formic acid and 2 mmol/L ammonium acetate on a Water TQD instrument in MRM mode. All compounds were detected in electrospray positive ion mode and could be quantified between 1 and 100 mg/L for amoxicillin and cefuroxime, between 0.5 and 80 mg/L for meropenem and ceftazidime, and between 1 and 150 mg/L for piperacillin. The method was validated in terms of precision, accuracy, linearity, matrix effect and recovery and has been compared to a previously published UPLC-MS/MS method. PMID:25531875
Evaluation of eight different cephalosporins for detection of cephalosporin resistance in Salmonella enterica and Escherichia coli.
Aarestrup, Frank M; Hasman, Henrik; Veldman, Kees; Mevius, Dik
This study evaluates the efficacy of eight different cephalosporins for detection of cephalosporin resistance mediated by extended spectrum beta-lactamases (ESBL) and plasmidic AmpC beta-lactamases in Salmonella and Escherichia coli. A total of 138 E. coli and 86 Salmonella isolates with known beta-lactamase genes were tested for susceptibility toward cefoperazone, cefotaxime, cefpodoxime, cefquinome, ceftazidime, ceftiofur, ceftriaxone, and cefuroxime using minimum inhibitory concentration determinations and disc diffusion. The collection consisted of 84 ampicillin-susceptible, 57 ampicillin-resistant but cephalosporin-susceptible, 56 ESBL isolates and 19 isolates with plasmidic AmpC, as well as 10 ampC hyper-producing E. coli. The minimum inhibitory concentration distributions and zone inhibitions varied with the tested compound. Ampicillin-resistant isolates showed reduced susceptibility to the cephalosporins compared to ampicillin-susceptible isolates. Cefoperazone, cefquinome, and cefuroxime were not useful in detecting isolates with ESBL or plasmidic AmpC. The best substances for detection were cefotaxime, cefpodoxime, and ceftriaxone, whereas ceftazidime and ceftiofur were not as efficient. Ceftriaxone may be the recommended substance for monitoring because of some ability in separating ampC hyper-producing E. coli from ESBL and plasmidic AmpC isolates. PMID:20624078
Antibiotic Prescribing Trends in an Omani Paediatric Population
Al-Balushi, Khalid; Al-Ghafri, Fatma; Al-Sawafi, Fatma; Al-Zakwani, Ibrahim
Objectives: This study aimed to evaluate antibiotic prescribing patterns for paediatric patients at Sultan Qaboos University Hospital (SQUH), a tertiary care hospital in Muscat, Oman. Methods: This retrospective cross-sectional study included all 1,186 prescriptions issued for 499 patients at the paediatric outpatient clinic and paediatric inpatient ward at SQUH between March and May 2012. Results: Of the 499 patients, 138 (27.6%) were prescribed a total of 28 different antibiotics. A total of 185 (15.6%) antibiotic prescriptions were issued among the total drug prescriptions. Preschool children aged 0¢6 years were prescribed antibiotics most frequently (n = 110). Co-amoxiclav was the most commonly prescribed antibiotic in both inpatients and outpatients (27.0% and 33.9%, respectively), followed by cefuroxime in inpatients (13.5%) and azithromycin in outpatients (18.6%). Co-amoxiclav was the most commonly prescribed antibiotic in both 0¢6 (31.3%) and 7¢11 (23.3%) year-olds, while cefuroxime was most commonly prescribed in children ?12 years old (25.0%). Conclusion: Antibiotic prescription patterns in this population were similar to those in North America, Europe and Asia. To confirm the findings of this study, further research on antibiotic prescription trends across the wider paediatric population of Oman should be initiated. PMID:25364552
In vitro study on the antimicrobial activity of various antibiotics against clinical isolates of Streptococcus pneumoniae from Belgium collected during winter 1998-1999.
Vanhoof, R; Carpentier, M; Fagnart, O; Garrino, M G; Glupczynski, Y; Gordts, B; Govaerts, D; Magerman, K; Mans, Y; Nyssen, H J; Surmont, I; Schwam, V; Van De Vyvere, M; Van Landuyt, H; Van Nimmen, L; Van Noyen, R
A total of 205 isolates of Streptococcus pneumoniae obtained from 10 different centres were included in this study. The susceptibilities to penicillin, ampicillin, amoxicillin, amoxicillin/clavulanic acid, cefaclor, cefuroxime, cefotaxime, imipenem, ciprofloxacin, gemifloxacin, grepafloxacin, levofloxacin, trovafloxacin, erythromycin, clarithromycin, miocamycin, clindamycin and tetracycline were determined by a microdilution technique following NCCLS recommendations. Decreased susceptibility to penicillin was 16.1% [6.8% intermediate (0.12-1 microgram/mL) and 9.3% high-level (> or = 2 micrograms/mL)], cefotaxime insusceptibility (> or = 1 microgram/mL) 12.7%, ciprofloxacine insusceptibility (> or = 2 micrograms/mL) 15.6% with 1.5% of high level resistance (> or = 4 micrograms/mL), erythromycin insusceptibility (> or = 0.5 microgram/mL) 36.1% and tetracycline insusceptibility (> or = 4 micrograms/mL) 22.9%. Decreased susceptibility to cefotaxime was found in 78.8% of the penicillin-insusceptible isolates. No decreased susceptibility was found for gemifloxacin (> or = 0.5 microgram/mL) and trovafloxacin (> or = 1 microgram/mL). Compared to the 1996-1997 surveillance, penicillin, cefotaxime and erythromycin insusceptibility rose by 3.8%, 5.2% and 5.0% respectively, while tetracycline insusceptibility decreased with 8.2%. MICs of all beta-lactams rose with those of penicillin for penicillin-insusceptible isolates. Amoxicillin +/- clavulanate, cefotaxime and imipenem were generally 1, 1 and 5 doubling dilutions respectively more potent than penicillin on these isolates. Penicillin, ampicillin and cefuroxime were equally active while cefaclor was generally 5 dilutions less potent. Most penicillin-insusceptible isolates remained fully susceptible to amoxicillin +/- clavulanate and imipenem. The penicillin-insusceptible isolates were 36.4%, 27.3% and 3.0% co-insusceptible to erythromycin, erythromycin plus tetracycline and tetracycline respectively. A subpopulation of 52 isolates obtained from children aged < or = 3 years was also studied. Compared to the other isolates we found a statistically significant increase in insusceptibility for penicillin, cefaclor, cefuroxime, erythromycin, clarithromycin and tetracycline while a significant decrease was found for ciprofloxacin. PMID:11484422
Evaluation and Complications of Direct Graft Puncture in Thrombolysis and Other Interventional Techniques
Cowling, Mark G.; Belli, Anna-Maria; Buckenham, Timothy M. [Department of Diagnostic Radiology, St. George's Hospital, Blackshaw Road, Tooting, London SW17 0QT (United Kingdom)
Purpose: To evaluate the value and complications of direct graft puncture in conducting interventional procedures in synthetic vascular bypass grafts. Methods: We retrospectively reviewed 65 direct graft punctures in 50 patients undergoing a variety of interventional vascular procedures. In two patients the grafts were found to be infected and the procedures abandoned. Results: Complications encountered included hematomas that did not require treatment in three patients, and four hematomas requiring surgical drainage. One graft became infected (despite prophylactic cefuroxime), after three consecutive punctures over a 10-day period for a variety of interventions. All the patients who developed hematomas had undergone pharmacological thrombolysis. Conclusion: Direct graft puncture is a relatively safe technique, with a minimal risk of infection and hemostatic complications attributable to thrombolysis. In 31 of the 41 patients undergoing successful thrombolysis, additional percutaneous procedures were undertaken, and these were facilitated by the direct graft puncture route.
Comparative in-vitro activity of tigemonam, a new monobactam.
Rylander, M; Gezelius, L; Norrby, S R
The in-vitro activity against Gram-negative aerobic bacterial pathogens of a new oral monobactam, tigemonam, was compared with those of amoxycillin/clavulanic acid, aztreonam, cefaclor, ceftazidime, cefuroxime, ciprofloxacin, co-trimoxazole and gentamicin, by an agar-dilution method. Tigemonam inhibited 90% of strains tested of Escherichia coli, Klebsiella spp., Proteus spp., Salmonella spp., Haemophilus influenzae and Branhamella catarrhalis at concentrations of 0.25 mg/l or below. The MIC90 for Enterobacter spp. was 16 mg/l and for Citrobacter 4 mg/l. Pseudomonas aeruginosa was resistant to tigemonam but susceptible to aztreonam. In comparison with the other oral antibiotics tested, tigemonam was generally more active. Tigemonam showed minimal inoculum dependence, between 10(2) and 10(6) cfu per spot. It is concluded that tigemonam is a candidate for clinical trials in patients with infections caused by Gram-negative aerobes other than pseudomonas and acinetobacter. PMID:3182428
Chromatographic studies of some cephalosporins on thin layers of silica gel G-zinc ferrocyanide.
Singh, Dhruv K; Maheshwari, Gunjan
A simple, selective and precise thin-layer chromatographic method has been developed for the analysis of eight cephalosporin antibiotics, namely cephadroxil, cephalexin, cefixime, cefaclor, cefpodoxime proxetil, cefuroxime axetil, cefotaxime sodium and ceftriaxone sodium. The hR(F) values of these cephalosporins were investigated on silica gel G-zinc ferrocyanide layers. Mixing of zinc ferrocyanide with silica gel G resulted in a decrease in hR(F) values, removal of tailing and better resolutions. The influence of silica gel G-zinc ferrocyanide ratio and mobile phases on the chromatographic behavior of cephalosporins on thin layers was investigated. Cephalosporins were selectively separated in their binary and ternary synthetic mixtures and pharmaceutical formulations. Quantitative separations of cephalosporins from their synthetic mixtures were also achieved with good recoveries (97.8-100.3%). PMID:20853462
Selective decontamination of the gastrointestinal tract as an infection control measure.
Taylor, M E; Oppenheim, B A
An outbreak caused by a Klebsiella aerogenes resistant to ceftazidime, cefuroxime, cefotaxime, ampicillin and piperacillin and sensitive to aminoglycosides, imipenem and temocillin occurred in a teaching hospital's busy multi-disciplinary Intensive Care Unit over a 3-month period. Four patients had bacteraemia and a further four were colonized. Traditional infection control measures failed to eradicate the outbreak. The introduction of a selective gastrointestinal decontamination regimen consisting of tobramycin, amphotericin and colistin as a gel to the oropharynx, nose and rectum and a suspension via a nasogastric tube resulted in rapid disappearance of the outbreak strain with no new isolates being detected clinically or in surveillance specimens over an 8-week period. PMID:1677652
Multiple resistant Pseudomonas aeruginosa in contemporary medical practice: findings from urinary isolates at a Nigerian University Teaching Hospital.
Jombo, G T A; Jonah, P; Ayeni, J A
Pseudomonas aeruginosa is a bacterium that is often encountered in urinary tract infection (UTI) worldwide and has shown varied antibiotic susceptibility patterns. This study was therefore designed to ascertain the antibiotic susceptibility patterns of the organism in Jos. Data on antimicrobial susceptibility of P. aeruginosa generated from urine samples by the Microbiology laboratory of Jos University Teaching Hospital (JUTH) was compiled for a period of three years (July 2001-June 2004). Additional information was obtained from the records department of the hospital. Samples were collected, stored and processed using standard laboratory procedures. The rate of isolation of P. aeruginosa from urine samples was found to be 4.6% (n=127) from 12,458 samples. From male population 34% (n=43) were isolated and 66 % (n=84) were recovered from females population with a significant (P < 0.05) gender difference. All the 100 % isolates of P. aeruginosa were resistant to penicillin, cloxacillin, tetracycline, nitrofurantoin and nalidixic acid. while 67% were sensitive to augmentin, sensitivity to ofloxacin was 92%, ciprofloxacin 92% and cefuroxime (86%). The resistance pattern of P. aeruginosa from urine against antibiotics was extremely high. Prophylactic antibiotic medication against UTI should be carefully weighed against this undesirable possible outcome (resistance). Susceptibility testing should be adopted as a basic routine laboratory procedure in hospitals and clinics in order to guide appropriately on the right choice of antibiotics. Finally, ofloxacin, ciprofloxacin, and cefuroxime should be considered on isolation of P. aeruginosa from UTI, especially in the absence of a sensitivity report as well as for prophylactic options. PMID:19434224
Incidence and transferability of antibiotic resistance in the enteric bacteria isolated from hospital wastewater.
Alam, Mohammad Zubair; Aqil, Farrukh; Ahmad, Iqbal; Ahmad, Shamim
This study reports the occurrence of antibiotic resistance and production of ?-lactamases including extended spectrum beta-lactamases (ES?L) in enteric bacteria isolated from hospital wastewater. Among sixty-nine isolates, tested for antibiotic sensitivity, 73.9% strains were resistant to ampicillin followed by nalidixic acid (72.5%), penicillin (63.8%), co-trimoxazole (55.1%), norfloxacin (53.6%), methicillin (52.7%), cefuroxime (39.1%), cefotaxime (23.2%) and cefixime (20.3%). Resistance to streptomycin, chloramphenicol, nitrofurantoin, tetracycline, and doxycycline was recorded in less than 13% of the strains. The minimum inhibitory concentration (MIC) showed a high level of resistance (800-1600 ?g/mL) to one or more antibiotics. Sixty three (91%) isolates produced ?-lactamases as determined by rapid iodometric test. Multiple antibiotic resistances were noted in both among ES?L and non-ES?L producers. The ?-lactamases hydrolyzed multiple substrates including penicillin (78.8% isolates), ampicillin (62.3%), cefodroxil (52.2%), cefotoxime (21.7%) and cefuroxime (18.8%). Fifteen isolates producing ES?Ls were found multidrug resistant. Four ES?L producing isolates could transfer their R-plasmid to the recipient strain E. coli K-12 with conjugation frequency ranging from 7.0 ū 10(-3) to 8.8 ū 10(-4). The findings indicated that ES?L producing enteric bacteria are common in the waste water. Such isolates may disseminate the multiple antibiotic resistance traits among bacterial community through genetic exchange mechanisms and thus requires immediate attention. PMID:24516448
Heat inactivation of beta-lactam antibiotics in milk.
Zorraquino, M A; Roca, M; Fernandez, N; Molina, M P; Althaus, R
The presence of residues of antimicrobial substances in milk is one of the main concerns of the milk industry, as it poses a risk of toxicity to public health, and can seriously influence the technological properties of milk and dairy products. Moreover, the information available on the thermostability characteristics of these residues, particularly regarding the heat treatments used in control laboratories and the dairy industry, is very scarce. The aim of the study was, therefore, to analyze the effect of different heat treatments (40 degrees C for 10 min, 60 degrees C for 30 min, 83 degrees C for 10 min, 120 degrees C for 20 min, and 140 degrees C for 10 s) on milk samples fortified with three concentrations of nine beta-lactam antibiotics (penicillin G: 3, 6, and 12 microg/liter; ampicillin: 4, 8, and 16 microg/liter; amoxicillin: 4, 8, and 16 microg/liter; cloxacillin: 60, 120, and 240 microg/liter; cefoperazone: 55, 110, and 220 microg/liter; cefquinome: 100, 200, and 400 microg/liter; cefuroxime: 65, 130, and 260 microg/liter; cephalexin: 80, 160, and 220 microg/ liter; and cephalonium: 15, 30, and 60 microg/liter). The method used was a bioassay based on the inhibition of Geobacillus stearothermophilus var. calidolactis. The results showed that heating milk samples at 40 degrees C for 10 min hardly produced any heat inactivation at all, while the treatment at 83 degrees C for 10 min caused a 20% loss in penicillin G, 27% in cephalexin, and 35% in cefuroxime. Of the three dairy industry heat treatments studied in this work, low pasteurization (60 degrees C for 30 min) and treatment at 140 degrees C for 10 s only caused a small loss of antimicrobial activity, whereas classic sterilization (120 degrees C for 20 min) showed a high level of heat inactivation of over 65% for penicillins and 90% for cephalosporins. PMID:18592745
A Systematic Review and Meta-Analysis of Antibiotic-Impregnated Bone Cement Use in Primary Total Hip or Knee Arthroplasty
Cheng, Tao; Peng, Xiaochun; Zhang, Wen; Qin, Hui; Zhang, Xianlong
Background Antibiotic-impregnated bone cement (AIBC) has been widely used for the treatment of infected revision arthroplasty, but its routine use in primary total joint arthroplasty (TJA) remains considerably controversial. With this meta-analysis of published randomized controlled trials, we intended to assess the antimicrobial efficacy and safety of AIBC for its prophylactic use in primary TJA. Methods A literature search was performed in MEDLINE, Embase, CBMdisc and the Cochrane Library until June, 2013. The studies were divided into two sub-groups according to the type of the control group. Outcomes of interest included postoperative infection rates, radiographic outcomes and clinical joint score. Study quality was evaluated using the Jadad scale (five points). Results In total, eight studies were included, with a sample size of 6,381 arthroplasties. The overall pooled data demonstrated that, compared with the control (plain cement or systemic antibiotic), AIBC did not reveal an advantage in decreasing the rate of superficial infection (relative risk [RR] = 1.47; 95% CI, 1.13¢1.91; P=0.004), while there were significant differences in deep infection rate between the AIBC and control group (RR = 0.41; 95% CI, 0.17¢0.97; P=0.04). For the analysis of gentamicin and cefuroxime subgroups, the gentamicin was superior to the cefuroxime in reducing deep infection rate (P=0.0005 versus P= 0.10). However, no significant differences were found in their radiographic outcomes and clinical joint score. Conclusion This meta-analysis had proven that the prophylactic use of AIBC could lower the deep infection rate in primary TJA, while AIBC did not show an improvement in reducing the superficial infection rate compared with the control. More sufficiently powered studies would be required to further evaluate the efficacy and safety of AIBC for primary TJA. PMID:24349353
Hospital antibiotic prescribing successfully modified by 'immediate concurrent feedback'.
Seto, W H; Ching, T Y; Kou, M; Chiang, S C; Lauder, I J; Kumana, C R
1. To determine the effectiveness of ongoing immediate concurrent feedback (ICF) in minimizing 'inappropriate' sultamicillin or co-amoxiclav prescribing via the parenteral route (i.e. when the oral route was accessible and not contraindicated), a prospective controlled audit was carried out on hospital inpatients over a 20 month period. 2. After an education programme to promote oral rather than unnecessary intravenous (i.v.) use of sultamicillin, co-amoxiclav and certain other drugs, an ongoing ICF strategy was instituted. 3. ICF entailed issue of memos on the following day to prescribers of i.v. sultamicillin or co-amoxiclav for inpatients in whom this route was deemed 'inappropriate', by a specially trained nurse using strict objective criteria. The memos recommended oral prescribing (particularly of co-amoxiclav, currently the less expensive alternative). 4. After starting ICF, there were consistent, clinically and statistically significant reductions in the monthly proportions of (i) admissions prescribed i.v. sultamicillin or co-amoxiclav (38% P < 0.001), (ii) those in whom the route was 'inappropriate' (75%, P < 0.001), and (iii) corresponding ratios of i.v./oral usage and expenditure, oral sultamicillin/co-amoxiclav usage and expenditure, as well as total and per admission expenditure on i.v. forms (> or = 43%, P < 0.01). 5. For i.v. cefuroxime (for which there was no ICF) and its oral counterpart cefuroxime-axetil, there were no comparable changes in usage or expenditure. 6. This simple, ongoing ICF strategy was effective and well accepted; estimated net monthly savings being HK$26-30,000. PMID:8866923
In vitro studies of fleroxacin (Ro 23-6240), a new trifluorinated quinolone derivative.
Digranes, A; Benonisen, E; Salveson, A; Zahm, F
The in vitro activity of fleroxacin (Ro 23-6240) against 441 bacterial isolates was compared with those of ciprofloxacin, ofloxacin, amoxycillin, cefadroxil, cefuroxime and tobramycin. An agar dilution method was used for the determination of minimal inhibitory concentrations (MICs). Ciprofloxacin showed the highest activity against the Enterobacteriaceae, 95% of the isolates were inhibited by 0.06 mg/l, but fleroxacin and ofloxacin were also highly active (MIC 90% = 0.5 and 0.25 mg/l, respectively). Ciprofloxacin was the most active agent against Pseudomonas aeruginosa (MIC 90% = 0.12 mg/l), whereas the activities of fleroxacin and ofloxacin were more variable. Tobramycin was highly active against P. aeruginosa, 75% of the isolates were inhibited by 0.5 mg/l or less. The quinolones and tobramycin exhibited high activity against Acinetobacter calcoaceticus, the great majority of the isolates being susceptible to 0.5 mg/l or less of any agent. All the quinolones showed high activity against Staphylococcus aureus, but fleroxacin was less active against Staphylococcus epidermidis and Staphylococcus saprophyticus than were the other derivatives. The pneumococcal and streptococcal isolates were markedly less susceptible to fleroxacin than to the other quinolones tested (MIC range 4-32 mg/l). All isolates of Haemophilus influenzae and Neisseria gonorrhoeae were inhibited by the lowest concentration of the quinolones employed in the study (0.03 mg/l). Cefuroxime was also highly active against N. gonorrhoeae, whether the strains were beta-lactamase-producing or not, but was somewhat less active against H. influenzae. The quinolones displayed moderate and similar activity against Bacteroides fragilis isolates (MIC range 1-16 mg/l). The MICs of fleroxacin against gram-negative rods were generally 4-16 times higher at pH 8.8 than those obtained at pH 5.8 and 7.3. The activity against gram-positive cocci was not markedly influenced by changes in pH. PMID:3141116
A simple assay to screen antimicrobial compounds potentiating the activity of current antibiotics.
Iqbal, Junaid; Siddiqui, Ruqaiyyah; Kazmi, Shahana Urooj; Khan, Naveed Ahmed
Antibiotic resistance continues to pose a significant problem in the management of bacterial infections, despite advances in antimicrobial chemotherapy and supportive care. Here, we suggest a simple, inexpensive, and easy-to-perform assay to screen antimicrobial compounds from natural products or synthetic chemical libraries for their potential to work in tandem with the available antibiotics against multiple drug-resistant bacteria. The aqueous extract of Juglans regia tree bark was tested against representative multiple drug-resistant bacteria in the aforementioned assay to determine whether it potentiates the activity of selected antibiotics. The aqueous extract of J. regia bark was added to Mueller-Hinton agar, followed by a lawn of multiple drug-resistant bacteria, Salmonella typhi or enteropathogenic E. coli. Next, filter paper discs impregnated with different classes of antibiotics were placed on the agar surface. Bacteria incubated with extract or antibiotics alone were used as controls. The results showed a significant increase (>30%) in the zone of inhibition around the aztreonam, cefuroxime, and ampicillin discs compared with bacteria incubated with the antibiotics/extract alone. In conclusion, our assay is able to detect either synergistic or additive action of J. regia extract against multiple drug-resistant bacteria when tested with a range of antibiotics. PMID:23865073
Microbial fuel cell-based diagnostic platform to reveal antibacterial effect of beta-lactam antibiotics.
Schneider, Gy÷rgy; Czeller, Mikl¾s; Rostßs, Viktor; Kovßcs, Tamßs
Beta-lactam antibiotics comprise the largest group of antibacterial agents. Due to their bactericidal properties and limited toxicity to humans they are preferred in antimicrobial therapy. In most cases, therapy is empiric since susceptibility testing in diagnostic laboratories takes a relatively long time. This paper presents a novel platform that is based on the microbial fuel cell (MFC) technology and focuses on the early antibiogram determination of isolates against a series of beta-lactam antibiotics. An advantage of the system is that it can be integrated into traditional microbiological diagnostic laboratory procedures. Tested bacterium suspensions are uploaded into the anodic chambers of each miniaturized MFC unit integrated into a panel system, containing different antibiotic solutions. Electronic signals gained in each MFC unit are continuously monitored and are proportional to the metabolic activity of the presenting test bacterium. Using this method, antibiotic susceptibility can be evaluated in 2-4h after inoculation. Hereby we demonstrate the efficacy of the platform in antibiogram determination by testing the susceptibilities of Escherichia coli strain ATCC 25922 and Staphylococcus aureus strain ATCC 29213 against 10 beta-lactam antibiotics (penicillin, ampicillin, ticarcillin, cefazolin, cefuroxime, cefoperazone, cefepime, cefoxitin, cefaclor, imipenem). This paper also presents the construction of the background instrumentation and the panel system into which a printed circuit board (PCB) based electrode was integrated. Our results suggest that MFC based biosensors have the potential to be used in diagnostics for antibiogram determination. PMID:26002505
Ceftriaxone-Resistant Salmonella enterica Serotype Typhimurium Sequence Type 313 from Kenyan Patients Is Associated with the blaCTX-M-15 Gene on a Novel IncHI2 Plasmid
Okoro, Chinyere; Kiiru, John; Omuse, Geoffrey; Langridge, Gemma; Kingsley, Robert A.; Dougan, Gordon; Revathi, Gunturu
Multidrug-resistant bacteria pose a major challenge to the clinical management of infections in resource-poor settings. Although nontyphoidal Salmonella (NTS) bacteria cause predominantly enteric self-limiting illness in developed countries, NTS is responsible for a huge burden of life-threatening bloodstream infections in sub-Saharan Africa. Here, we characterized nine S. Typhimurium isolates from an outbreak involving patients who initially failed to respond to ceftriaxone treatment at a referral hospital in Kenya. These Salmonella enterica serotype Typhimurium isolates were resistant to ampicillin, chloramphenicol, cefuroxime, ceftriaxone, aztreonam, cefepime, sulfamethoxazole-trimethoprim, and cefpodoxime. Resistance to ?-lactams, including to ceftriaxone, was associated with carriage of a combination of blaCTX-M-15, blaOXA-1, and blaTEM-1 genes. The genes encoding resistance to heavy-metal ions were borne on the novel IncHI2 plasmid pKST313, which also carried a pair of class 1 integrons. All nine isolates formed a single clade within S. Typhimurium ST313, the major clone of an ongoing invasive NTS epidemic in the region. This emerging ceftriaxone-resistant clone may pose a major challenge in the management of invasive NTS in sub-Saharan Africa. PMID:25779570
Resistance phenotypes and genotypes among multiple-antimicrobial-resistant Salmonella enterica subspecies enterica serovar Choleraesuis strains isolated between 2008 and 2012 from slaughter pigs in Okinawa Prefecture, Japan
MATAYOSHI, Masanao; KITANO, Takashi; SASAKI, Tetsu; NAKAMURA, Masaji
A total of 349 Salmonella enterica subspecies enterica serovar Choleraesuis (S. Choleraesuis) strains, which were isolated between 2008 and 2012 from 349 pigs at two slaughterhouses in Okinawa Prefecture, Japan, were investigated for antimicrobial susceptibility and the presence of antimicrobial resistance genes. All isolates were resistant to at least four antimicrobial agents. The antimicrobial agents for which isolates showed a high incidence of resistance were as follows: ampicillin (100%) and streptomycin (100%), followed by gentamicin (99.7%), oxytetracycline (99.7%), sulfamethoxazole/trimethoprim (99.4%), nalidixic acid (40.1%) and oxolinic acid (40.1%). All isolates were sensitive to cefuroxime, ceftiofur, colistin, fosfomycin, enrofloxacin, orbifloxacin and danofloxacin. The predominant resistance phenotypes and genotypes were: resistance to ampicillin, streptomycin, gentamicin, oxytetracycline and sulfamethoxazole/trimethoprim (58.5%, 204/349) and blaTEM-strA-strB-aadA1-aadA2-aacC2-tet (B)-sul1-sul2-dhfrXII-dhfrXIII (36.1%, 126/349). The quinolone resistance-determining regions (QRDRs) of gyrA, gyrB, parC and parE of the quinolone-resistant isolates (n=12) showed amino acid substitutions of Ser-83?Phe or Asp-87?Tyr in GyrA and Ser-107?Ala in ParC. To our knowledge, this is the first report on the molecular characterization of antimicrobial resistance among S. Choleraesuis strains in Japan. PMID:25715779
Identification of penicillinase producing Neisseria gonorrhoeae in Chile during clinical and microbiological study of gonococcal susceptibility to antimicrobial agents.
Garcia Moreno, J; Dillon, J R; Arroyave, R; Maldonado, A; Fich, F; Salvo, A; Villalobos, D; Vincent, P; Pauze, M
The first penicillinase producing isolates of Neisseria gonorrhoeae (PPNG) identified in Chile were discovered during a clinical and microbiological study to compare the efficacy of penicillin (4.8 MIU aqueous procaine penicillin G plus 1 g oral probenecid) and tetracycline (1.5 g followed by 500 mg four times daily for four days) treatment regimens for acute uncomplicated gonorrhoea. Penicillin treatment was effective in 93.1% (282) of 303 patients, whereas tetracycline was effective in 98.3% (233) of 237 patients. Six of the penicillin treatment failures were attributable to PPNG strains. In all, 21 PPNG strains were identified during the study. They were genetically identical, having a wild type auxotype, a WII/III serotype (serovar Bajk), and carrying cryptic and transfer plasmids and an Asian type penicillinase producing plasmid. In addition, 674 non-PPNG isolates were tested for their susceptibility to eight antimicrobials. Over 95% were sensitivie to 1 mg/l of penicillin, ampicillin, cefotaxime, cefuroxime, and erythromycin, over 90% were sensitive to 1 mg/l of tetracycline and 2 mg/l of thiamphenicol, and all were sensitive to spectinomycin. Of 226 non-PPNG isolates characterised for plasmid content and auxotype, 90% (205) were either wild type or proline requiring, 67% (153) carried only the cryptic plasmid, and a further 31% (71) carried both cryptic and transfer plasmids. Unusually, three of four isolates lacking the cryptic plasmid carried only the transfer plasmid. Images PMID:3102348
Ceftriaxone-Resistant Salmonella enterica Serotype Typhimurium Sequence Type 313 from Kenyan Patients Is Associated with the blaCTX-M-15 Gene on a Novel IncHI2 Plasmid.
Kariuki, Samuel; Okoro, Chinyere; Kiiru, John; Njoroge, Samuel; Omuse, Geoffrey; Langridge, Gemma; Kingsley, Robert A; Dougan, Gordon; Revathi, Gunturu
Multidrug-resistant bacteria pose a major challenge to the clinical management of infections in resource-poor settings. Although nontyphoidal Salmonella (NTS) bacteria cause predominantly enteric self-limiting illness in developed countries, NTS is responsible for a huge burden of life-threatening bloodstream infections in sub-Saharan Africa. Here, we characterized nine S. Typhimurium isolates from an outbreak involving patients who initially failed to respond to ceftriaxone treatment at a referral hospital in Kenya. These Salmonella enterica serotype Typhimurium isolates were resistant to ampicillin, chloramphenicol, cefuroxime, ceftriaxone, aztreonam, cefepime, sulfamethoxazole-trimethoprim, and cefpodoxime. Resistance to ?-lactams, including to ceftriaxone, was associated with carriage of a combination of blaCTX-M-15, blaOXA-1, and blaTEM-1 genes. The genes encoding resistance to heavy-metal ions were borne on the novel IncHI2 plasmid pKST313, which also carried a pair of class 1 integrons. All nine isolates formed a single clade within S. Typhimurium ST313, the major clone of an ongoing invasive NTS epidemic in the region. This emerging ceftriaxone-resistant clone may pose a major challenge in the management of invasive NTS in sub-Saharan Africa. PMID:25779570
The antibiotic sensitivity of bacteria isolated from the blood of patients in St Thomas' Hospital, 1969-1988.
Phillips, I; King, A; Gransden, W R; Eykyn, S J
We have monitored the antibiotic sensitivity of bloodstream isolates of common bacteria over a period of 20 years. Among the Gram-positive bacteria, the proportion of isolates of Staphylococcus aureus resistant to methicillin, erythromycin, fusidate, or gentamicin has increased marginally, while that of coagulase-negative staphylococci (mostly Staph. epidermidis) has increased markedly. Enterococci are becoming serially more resistant to high concentrations of aminoglycosides. The Enterobacteriaceae have become considerably less sensitive to ampicillin (and amoxycillin) and trimethoprim but more sensitive to the aminoglycosides, whilst their susceptibility to cefotaxime, ceftazidime, cefepime, cefpirome, imipenem, meropenem and temocillin has remained constant. We have some evidence that in-vitro resistance is clinically relevant since the mortality rate rises if inappropriate antibiotics are used empirically. Although many drug regimens could be used, we are able to recommend initial therapy with a combination of gentamicin and cefuroxime for most of our patients, the exceptions being those known to be infected with resistant organisms before the onset of septicaemia. PMID:2112124
Ultrasound-assisted matrix solid phase dispersive extraction for the simultaneous analysis of ?-lactams (four penicillins and eight cephalosporins) in milk by high performance liquid chromatography with photodiode array detection.
Karageorgou, Eftichia G; Samanidou, Victoria F; Papadoyannis, Ioannis N
The application of ultrasound-assisted matrix solid phase dispersive extraction for the confirmatory analysis of 12 ?-lactam antibiotics in milk by high performance liquid chromatography with photodiode array detection has been proposed herein. Four penicillins (cloxacillin, dicloxacillin, oxacillin, and amoxicillin) and eight cephalosporins (cefaclor, cefadroxil, ceftiofur, cefuroxime, cefoperazone, cefazolin, cephalexin, and cefotaxime) are effectively extracted using a mixed sorbent of Quick Easy Cheap Effective Rugged Safe technique and OASIS HLB providing a matrix free from any endogenous interference. Examined analytes were well resolved on an Inertsil ODS-3 analytical column with a mobile phase of CH(3)COONH(4) (0.05 M) and acetonitrile delivered under a gradient program. 1,7-Dimethyl-xanthine was used as internal standard. The method was validated meeting the European Legislation determining linearity, selectivity, stability, decision limit, detection capability, accuracy, precision, and ruggedness according to the Youden approach. Recoveries of all antibiotics rated from 85.0 to 115.7%, while RSD values were <12.7%. Finally, the method was successfully applied to milk samples purchased from local market. PMID:22941669
Antibiotic resistance pattern of Pseudomonas aeruginosa isolated from urine samples of Urinary Tract Infections patients in Karachi, Pakistan
Shah, Dania Aijaz; Wasim, Shehnaz; Essa Abdullah, Farhan
Objective: The aim of this study was to evaluate the antibiotic resistance pattern of Psedomonas aeruginosa and its prevalence in patients with urinary tract infections (UTI) for effective treatment in a developing country like Pakistan. Methods: This is an observational study conducted for a period of ten months which ended on December 2013 at the Dr. Essa Laboratory and Diagnostic Centre in Karachi. A total of 4668 urine samples of UTI patients were collected and standard microbiological techniques were performed to identify the organisms in urine cultures. Antibiotic susceptibility testing was performed by Kirby-Bauer technique for twenty five commonly used antimicrobials and then analyzed on SPSS version 17. Results: P. aeruginosa was isolated in 254 cultures (5.4%). The most resistant drugs included Ceclor(100%) and Cefizox (100%) followed by Amoxil/Ampicillin (99.6%), Ceflixime (99.6%), Doxycycline (99.6%), Cefuroxime (99.2%), Cephradine (99.2%), Cotrimoxazole (99.2%), Nalidixic acid (98.8%), Pipemidic acid (98.6%) and Augmentin (97.6%). Conclusion: Emerging resistant strains of Pseudomonas aeruginosa are potentially linked to injudicious use of drugs leading to ineffective empirical therapy and in turn, appearance of even more resistant strains of the bacterium. Therefore, we recommend culture and sensitivity testing to determine the presence of P.aeruginosa prior to specific antimicrobial therapy.
Prevalence, Spectrum and Antibiotic Susceptibility of Bacterial and Candida Colonization between the 21st and 33rd Week of Gestation in Women with PPROM ¢ 5 Years? Experience in 1 Perinatal Center
Reinhard, J.; Sõnger, N.; Hanker, L. C.; Peiffer, S.; Yuan, J.; Kempf, V. A. J.; Louwen, F.
Objective: The aim of this study was to evaluate the prevalence, spectrum and antibiotic susceptibility of bacterial and Candida colonization of the vagina between the 21st and the 33rd week of gestation in women who had preterm premature rupture of membranes (PPROM). Study design: High vaginal swabs from 245 subjects with PPROM were analyzed in a retrospective cohort study using cultivation-dependent methods. Patients were additionally divided into two groups: women with PPROM between the 21st and 27th week of gestation (group A) and women with PPROM between the 28th and 33rd week of gestation (group B). A subgroup analysis comparing the two groups was done. Results: The prevalence of pathological bacterial colonization was similar in both study groups (40.8 vs. 41.4?%; p?>?0.05), however, a difference in antibiotic susceptibility was noted, which did not reach statistical significance (resistance to ampicillin 71.4 vs. 52.5?%; cefuroxime 9.5 vs. 11.7?%; gentamicin 28.6 vs. 16.4?%; ciprofloxacin 5.0 vs. 5.4?%). In group A there was a statistically significant lower rate of Candida colonization (11.1 vs. 24.3?%; p?=?0.04). Conclusion: In patients with early PPROM, the rate of Candida colonization (group A) is lower and there are indications of a difference in antibiotic susceptibility of the colonizing bacteria depending on gestational age. Larger study groups are required to confirm these preliminary results. PMID:24771885
In Vitro Activities of Cephalosporins and Quinolones against Escherichia coli Strains Isolated from Diarrheic Dairy Calves
Orden, Josķ Antonio; Ruiz-Santa-Quiteria, Josķ Antonio; GarcĒa, Silvia; Cid, Dolores; de la Fuente, Ricardo
The in vitro activities of several cephalosporins and quinolones against 195 strains of Escherichia coli isolated from dairy calves affected by neonatal diarrhea were determined. One hundred thirty-seven of these strains produced one or more potential virulence factors (F5, F41, F17, cytotoxic necrotizing factor, verotoxin, and the eae gene), but the remaining 58 strains did not produce any of these factors. From 11 to 18% of the E. coli strains were resistant to cephalothin, nalidixic acid, enoxacin, and enrofloxacin. However, cefuroxime, cefotaxime, and cefquinome were highly effective against the E. coli isolates tested. Some significant differences (P < 0.05) in resistance to quinolones between the strains producing potential virulence factors and nonfimbriated, nontoxigenic, eae-negative strains were found. Thus, eae-positive, necrotoxigenic, and verotoxigenic (except for nalidixic acid) E. coli strains were significantly more sensitive to nalidixic acid, enoxacin, and enrofloxacin than nonfimbriated, nontoxigenic, eae-negative strains. Moreover, eae-positive strains were significantly more sensitive to enoxacin and enrofloxacin than F5-positive strains. Thus, the results of this study suggest that the bovine E. coli strains that produce some potential virulence factors are more sensitive to quinolones than those that do not express these factors. PMID:10049259
In vitro activities of cephalosporins and quinolones against Escherichia coli strains isolated from diarrheic dairy calves.
Orden, J A; Ruiz-Santa-Quiteria, J A; GarcĒa, S; Cid, D; De La Fuente, R
The in vitro activities of several cephalosporins and quinolones against 195 strains of Escherichia coli isolated from diary calves affected by neonatal diarrhea were determined. One hundred thirty-seven of these strains produced one or more potential virulence factors (F5, F41, F17, cytotoxic necrotizing factor, verotoxin, and the eae gene), but the remaining 58 strains did not produce any of these factors. From 11 to 18% of the E. coli strains were resistant to cephalothin, nalidixic acid, enoxacin, and enrofloxacin. However, cefuroxime, cefotaxime, and cefquinome were highly effective against the E. coli isolates tested. Some significant differences (P < 0.05) in resistance to quinolones between the strains producing potential virulence factors and nonfimbriated, nontoxigenic, eae-negative strains were found. Thus, eae-positive, necrotoxigenic, and verotoxigenic (except for nalidixic acid) E. coli strains were significantly more sensitive to nalidixic acid, enoxacin, and enrofloxacin than nonfimbriated, nontoxigenic, eae-negative strains. Moreover, eae-positive strains were significantly more sensitive to enoxacin and enrofloxacin than F5-positive strains. Thus, the result of this study suggest that the bovine E. coli strains that produce some potential virulence factors are more sensitive to quinolones than those that do not express these factors. PMID:10049259
Combinations of cefoxitin plus other ?-lactams are synergistic in vitro against community associated methicillin-resistant Staphylococcus aureus.
Banerjee, R; Fernandez, M G; Enthaler, N; Graml, C; Greenwood-Quaintance, K E; Patel, R
In vitro studies demonstrate that oxacillin minimal inhibitory concentrations (MICs) of methicillin-resistant S. aureus (MRSA) strains USA300 and 400 decrease in the presence of cefoxitin. The aim of this study was to characterize the activity of cefoxitin plus ?-lactams against a collection of MRSA isolates. We assessed the in vitro antimicrobial activity of a selection of ?-lactams alone and together with subinhibitory concentrations of cefoxitin against a collection of MRSA, methicillin-susceptible S. aureus (MSSA), and vancomycin-intermediate S. aureus (VISA) isolates using MICs and time kill assays. For community-associated (CA) MRSA strains USA300 and USA400, MICs of nafcillin, cefazolin, cephalexin, cefuroxime, ceftriaxone and cefotaxime decreased by 8- to 64-times in the presence of 10 ?g/ml cefoxitin. In contrast, for hospital-associated (HA) strains COLn, N315, and Mu50, there was no change in any ?-lactam MIC in the presence of cefoxitin. When combined with cefoxitin, the cephalexin MIC decreased for eight CA-MRSA and five MSSA sequence types but did not change for seven HA-MRSA sequence types. ?-lactam/cefoxitin combinations were synergistic against CA- but not HA-MRSA strains in time kill assays. Cefoxitin combined with a variety of ?-lactams enhances their activity against CA-MRSA strains in vitro. Further studies of combination ?-lactam therapy may provide insight into ?-lactam biology, penicillin binding protein cooperativity, and novel therapeutic strategies against MRSA. PMID:23340864
Antibiotic Resistance in Uropathogenic E. Coli Strains Isolated from Non-Hospitalized Patients in Pakistan
Ali, Ihsan; Kumar, Neeraj; Ahmed, Safia
Purpose: To study multidrug-resistance in Uropathogenic E. Coli (UPEC) isolated from non-hospitalized patients. Materials and Methods: Altogether, 250 bacterial samples were collected from non-hospitalized patients. Their identifications were done on basis of Gram-staining, colony morphology, biochemical testing and PCR. Susceptibility testing was performed by using standard protocols which were recommended by CLSI. Statistical analysis: For comparisons, statistical analysis was performed by using software, Graphpad Prism 5.0 Results: In total, 32% (n = 80) of the isolates were identified as E. Coli strains and their susceptibility patterns for different antibiotics were determined. The data indicated least resistance against tazocin [(TZP) -1.25%], amikacin [(AK) -1.8%], tigecycline [(TGC)- 2.5%] and nitrofurantoin [(F) -3.75%]. For both minocycline (MH) and sulzone (SUL), resistance rate was 5%, for gentamicin (CN), it was 16.25%, while higher resistances were observed against cephalothine [(KF)- 70%], cefotaxime [(CTX) -58.5%], ceftazidime [(CAZ)- 57.5%], cefepime [(FEP) -55%], cefuroxime and cefixime [(CXM) (CFM)- 53.75 %]. Resistance against ciprofloxacin (CIP) was 57.5%, for norfloxacine (NOR), it was 52.5% and incase of sparfloxacin (SPX), it remained 55%. High percentage of the isolates were resistant to cotrimoxazole [(SXT) -86%] and Amoxicillin [AMX-CLA (AMC)- 76%]. No resistance against meropenem (MEM) was observed. Conclusion: Highest level of drug-resistance was observed against trimethoprim-sulfamethoxazole (TMP-SMZ) among clinical isolates of uropathogenic E. Coli collected from non-hospitalized patients. PMID:25386430
Minimum inhibitory concentrations of selected antimicrobials against Escherichia coli and Trueperella pyogenes of bovine uterine origin.
de Boer, Melvin; Heuer, Cord; Hussein, Hassan; McDougall, Scott
Minimum inhibitory concentrations (MIC) of 9 antimicrobials for isolates of 2 common bovine intrauterine bacterial pathogens, Escherichia coli (n=209) and Trueperella pyogenes (n=35), were determined using broth microdilution methodology. The isolates were recovered from dairy cows from 7 herds postpartum using the cytobrush technique. The pathogens were initially identified using phenotypic techniques. Additionally, PCR was used to confirm the identity of T. pyogenes isolates and to categorize the E. coli isolates into phylogenetic groups A, B1, B2, and D. Minimum inhibitory concentrations in excess of published cut-points or bimodal distributions of MIC indicated potential antimicrobial resistance to ampicillin, cefuroxime, cephapirin, and oxytetracycline for E. coli, and to oxytetracycline for T. pyogenes. Of the antimicrobials tested, ticarcillin/clavulanic acid, ceftiofur, and enrofloxacin had the lowest MIC for these 2 pathogens. Differences in MIC of some antimicrobials were found between herds, age, breeds, and E. coli phylogenetic groups. Isolation of E. coli with an MIC ?8?g/mL of oxytetracycline at 23d postpartum was associated with a lower probability of pregnancy within 6wk of commencement of breeding compared with those isolates with an MIC <8?g/mL (relative risk=0.66). Minimum inhibitory concentrations for uterine pathogens were determined for isolates from New Zealand dairy cows. However, in the absence of either epidemiological or clinical interpretive criteria, the interpretation of these MIC remains unclear. Further studies are required to define interpretative criteria, including determination of pharmacokinetic and pharmacodynamic profiles for antimicrobials. PMID:25935246
Antimicrobial Susceptibilities of 1,684 Streptococcus pneumoniae and 2,039 Streptococcus pyogenes Isolates and Their Ecological Relationships: Results of a 1-Year (1998¢1999) Multicenter Surveillance Study in Spain
Pķrez-Trallero, E.; Fernßndez-Mazarrasa, C.; GarcĒa-Rey, C.; Bouza, E.; Aguilar, L.; GarcĒa-de-Lomas, J.; Baquero, F.
A nationwide multicenter susceptibility surveillance study which included 1,684 Streptococcus pneumoniae and 2,039 S. pyogenes isolates was carried out over 1 year in order to assess the current resistance patterns for the two most important gram-positive microorganisms responsible for community-acquired infections in Spain. Susceptibility testing was done by a broth microdilution method according to National Committee for Clinical Laboratory Standards M100-S10 interpretative criteria. For S. pneumoniae, the prevalences of highly resistant strains were 5% for amoxicillin and amoxicillin-clavulanic acid; 7% for cefotaxime; 22% for penicillin; 31% for cefuroxime; 35% for erythromycin, clarithromycin, and azithromycin; and 42% for cefaclor. For S. pyogenes, the prevalence of erythromycin resistance was 20%. Efflux was encountered in 90% of S. pyogenes and 5% of S. pneumoniae isolates that exhibited erythromycin resistance. Erythromycin resistance was associated with clarithromycin and azithromycin in both species, regardless of phenotype. Despite the different nature of the mechanisms of resistance, a positive correlation (r = 0.612) between the two species in the prevalence of erythromycin resistance was found in site-by-site comparisons, suggesting some kind of link with antibiotic consumption. Regarding ciprofloxacin, the MIC was ?4 ?g/ml for 7% of S. pneumoniae and 3.5% of S. pyogenes isolates. Ciprofloxacin resistance (MIC, ?4 ?g/ml) was significantly (P < 0.05) associated with macrolide resistance in both S. pyogenes and S. pneumoniae and with penicillin nonsusceptibility in S. pneumoniae. PMID:11709305
Antibiotic pharmacoeconomics: an attempt to find the real cost of hospital antibiotic prescribing.
Kerr, J. R.; Barr, J. G.; Smyth, E. T.; O'Hare, J.; Bell, P. M.; Callender, M. E.
Antibiotics account for a large part of all hospital pharmacy budgets, but the actual cost of their prescription is unknown. These costs include intravenous administration, labour, serum antibiotic assay, monitoring of haematological and biochemical indices, disposal of sharps and adverse effects. An in-house method of costing antibiotic therapy is presented, to quantify these hidden expenses. Since not only an awareness, but an accurate quantification, of hidden costs is required, a study of various hospital procedures relating directly to antibiotic therapy was undertaken in an acute medical ward; this involved the identification of particular staff members performing various procedures, consumables used and time taken. The cost of five-day courses of gentamicin, penicillin G, ampicillin, flucloxacillin, cefuroxime, ceftotaxime and erythromycin has been calculated; drug and hidden costs for each are presented graphically for comparison. The breakdown cost for gentamicin is presented to illustrate the method. The costing of adverse effects has not been attempted. We suggest that costings of this sort are used in cost-benefit analysis of antibiotic use. These calculations have been incorporated into a computer spreadsheet and this costing service will be offered to clinical areas of our hospital. PMID:8516976
[Tinea capitis profunda due to Trichophyton verrucosum with cMRSA superinfection in an infant].
Bl÷mer, R-H; Keilani, N; Faber, A; Rodeck, B; Kr³ger, C; Uhrla▀, S; Grõser, Y; Nenoff, P
A 28-month-old boy developed a cutaneous and subcutaneous lesion of the scalp together with alopecia. Treatment with sulfadiazine silver ointment and oral administration of cefaclor failed. The boy lived on a farm where cows and calves were present. He presented with a 5 cm erythematous, erosive, edematous, and sharply defined lesion with yellow crusts and circumscribed alopecia on the temporoparietal scalp. Peripheral hairs were easily epilated. Swabs from the wound revealed cMRSA (community acquired methicillin-resistant Staphylococcus aureus, Panton Valentine Leukocidin [PVL] toxin negative). There was no improvement after treatment with cefuroxime intravenously over 3 days. Therapy was changed to vancomycin and fosfomycin. Because of the purulent abscess, surgical incision was performed. PCR (polymerase chain reaction)-Elisa assay detected Trichophyton (T.) interdigitale-DNA from wound secretion and skin biopsy. Because of the clinical and molecular diagnosis of tinea capitis, oral antifungal therapy with fluconazole 5 mg kg(-1) body weight was started, along with cotrimoxazole and fosfomycin for the cMRSA. After 4 weeks incubation, the causative agent T. verrucosum was grown on culture and its identity confirmed by sequencing of the "internal transcribed spacer" (ITS) region of the ribosomal DNA. After 4 weeks of fluconazole, the lesion was nearly healed. PMID:22406762
Antimicrobial Susceptibilities of Aeromonas spp. Isolated from Environmental Sources?
Huddleston, Jennifer R.; Zak, John C.; Jeter, Randall M.
Aeromonas spp. are ubiquitous aquatic bacteria that cause serious infections in both poikilothermic and endothermic animals, including humans. Clinical isolates have shown an increasing incidence of antibiotic and antimicrobial drug resistance since the widespread use of antibiotics began. A total of 282 Aeromonas pure cultures were isolated from both urban and rural playa lakes in the vicinity of Lubbock, Texas, and several rivers in West Texas and New Mexico. Of these, at least 104 were subsequently confirmed to be independent isolates. The 104 isolates were identified by Biolog and belonged to 11 different species. The MICs of six metals, one metalloid, five antibiotics, and two antimicrobial drugs were determined. All aeromonads were sensitive to chromate, cobalt, copper, nickel, zinc, cefuroxime, kanamycin, nalidixic acid, ofloxacin, tetracycline, and sulfamethoxazole. Low incidences of trimethoprim resistance, mercury resistance, and arsenite resistance were found. Dual resistances were found in 5 of the 104 Aeromonas isolates. Greater numbers of resistant isolates were obtained from samples taken in March versus July 2002 and from sediment versus water. Plasmids were isolated from selected strains of the arsenite- and mercury-resistant organisms and were transformed into Escherichia coli XL1-Blue MRF?. Acquisition of the resistance phenotypes by the new host showed that these resistance genes were carried on the plasmids. Mercury resistance was found to be encoded on a conjugative plasmid. Despite the low incidence of resistant isolates, the six playa lakes and three rivers that were sampled in this study can be considered a reservoir for antimicrobial resistance genes. PMID:16950901
An outbreak of caprine meningoencephalitis due to Escherichia coli O157:H7.
Filioussis, George; Petridou, Evanthia; Karavanis, Emmanouel; Giadinis, Nektarios D; Xexaki, Anna; Govaris, Alexandros; Kritas, Spyridon K
Five 1-month-old kid goats from a local herd in Kozani (northwest Greece) developed neurological disorders characterized by decreased appetite, ataxia, and head pressing. The animals received a 3-day course of treatment with intramuscular administration of enrofloxacin and ketoprofen. However, no significant clinical improvement was achieved, and 2 kids died. The remaining 3 animals were euthanized, and a necropsy was performed within 1 hr. Macroscopic lesions were confined to the central nervous system, with congestion and petechiae in the meninges. Microscopic lesions in all 3 animals revealed multifocal acute meningoencephalitis characterized by infiltrations composed of mononuclear inflammatory cells, lesser numbers of lymphocytes, and occasionally neutrophils and eosinophils. Additionally, in the kidney, there was multifocal expansion of the glomerular tufts by eosinophilic amorphous material, multifocal interstitial hemorrhages, and multifocal glomerular hypercellularity. The above noted lesions are consisted with an acute ongoing nephropathy indicative of a septicemic-toxemic procedure at its primary stages. Small, gray bacterial colonies, 3-4 mm in diameter, were obtained in pure culture from the brain of all 3 necropsied animals and were confirmed as Escherichia coli O157:H7 by use of phenotypic and genotypic methods. The isolates were sensitive to cefuroxime, ceftazidime, and gentamicin. In contrast, resistance to enrofloxacin, trimethoprim-sulfamethoxazole, and tetracycline was displayed. Additionally the bacterial isolates were found to carry a plasmid that harbored qnrS, sulII, and tetB genes that contribute to high-level resistance to fluoroquinolones, co-trimoxazole, and tetracycline, respectively. PMID:24153034
In vitro activities of 36 antimicrobial agents against clinically isolated Bacteroides fragilis.
Teng, L J; Ho, S W; Chang, S C; Luh, K T; Hsieh, W C
Thirty-six antimicrobial agents were evaluated for in vitro activities against 100 clinical isolates of Bacteroides fragilis. The minimal inhibitory concentration (MIC) of each agent for each isolate was determined by the agar dilution method. Among 25 beta-lactam antibiotics, the most active agent was imipenem with an MIC90 and a geometric mean of 1 and 0.15 micrograms/ml, respectively; followed by ticarcillin-clavulanic acid, and amoxicillin-clavulanic acid. Ampicillin-sulbactam, piperacillin-tazobactam, moxalactam, and flomoxef were the next most active agents. Piperacillin, ticarcillin, ceftizoxime, cefotaxime, cefuzonam, cefoxitin, and cefmetazole were equally active with the MIC50s ranging from 4 to 16 micrograms/ml, and MIC90s ranging from 32 to greater than or equal to 256 micrograms/ml. The remaining 10 beta-lactam antibiotics, ampicillin, amoxicillin, cefazolin, cefuroxime, cefoperazone, cefmenoxime, ceftazidime, cefpirome, aztreonam, and carumonam were less active. All isolates were resistant to cefotiam at a low breakpoint. Among 6 quinolones, ciprofloxacin was the most active agent with an MIC50 and an MIC90 of 4 and 16 micrograms/ml, respectively. All isolates were resistant to nalidixic acid, pipemidic acid, cinoxacin, enoxacin, and norfloxacin. Among 5 frequently used agents, chloramphenicol, ornidazole, and metronidazole were the most effective agents which inhibited 100% of the isolates at 8, 2, and 2 micrograms/ml, respectively; while clindamycin and minocycline had less activity. PMID:1683376
Comparison of two prophylactic single-dose intravenous antibiotic regimes in the treatment of patients undergoing elective colorectal surgery in a district general hospital.
Kingston, R D; Kiff, R S; Duthie, J S; Walsh, S; Spicer, A; Jeacock, J
Two hundred and twenty-nine patients were entered into a study to compare the effectiveness and safety of two single-shot antibiotic regimes in patients undergoing elective colorectal surgery in two district general hospitals. A single shot of intravenous (IV) latamoxef disodium was as effective as an IV combination of cefuroxime and metronidazole in control of wound infection following elective large bowel surgery when given as a bolus at the time of anaesthetic induction. The incidence of major wound infection was 6% and was evenly distributed in the two treatment groups. Half the major wound infections were associated with faecal fistulae. A single shot of IV antibiotic at the time of anaesthetic induction was safe, simple and an effective prophylaxis against major wound infection. There was a low incidence (1.3%) of serious postoperative bleeding and no serious adverse reactions were noted. The overall mortality was 9%. Death was significantly related to elderly patients, a poor performance status, operative contamination and wound infections. PMID:2810183
[Antibacterial activity of carumonam and cefpirome on hospital strains resistant to gentamicin and cephalothin: comparison with other beta-lactam antibiotics, new fluoroquinolones, aminoglycosides and other antibiotics].
Vanhoof, R; Nyssen, H J; Nulens, E; Roebben, E; Hubrechts, J M
The antibacterial in vitro activity of carumonam, a new monobactam, and cefpirome, a new cephalosporin, was studied on 483 hospital strains resistant to gentamicin and cephalothin, in comparison with amikacin, azlocillin, aztreonam, cefmenoxim, cefoperazone, cefotaxim, cefsulodin (for Pseudomonas), ceftazidime, ceftriaxone, cefuroxim, chloramphenicol, ciprofloxacin, doxycycline, enoxacin, netilmicin, norfloxacin, pefloxacin, piperacillin, rifampicin, tobramycin and trimethoprim. In general the two compounds have a very good in vito activity on Enterobacteriaceae but are less active on non-fermenting microorganisms. For the Enterobacteriaceae the minimal inhibitory concentrations 90% for carumonam was less than or equal to 1.1 mg/l excepted for Enterobacter spp. (43,6 mg/l) and M. morganii (56.8 mg/l) . All the Enterobacteriaceae are susceptible to cefpirome (minimal inhibitory concentrations 90% less than or equal to 5.3 mg/l). The activity of carumonam and cefpirome on Enterobacteriaceae is comparable with that of the third generation cephalosporins. Carumonam is more active than cefpirome and other beta-lactams, ceftazidime excepted, on Pseudomonas aeruginosa and Pseudomonas spp. On the other hand, both compounds reveal to have only a low activity on the other non-fermenters which minimal inhibitory concentrations 90% values of 115.4 mg/l for carumonam and 32.0 mg/l for cefpirome. PMID:2165238
Bayes, M; Rabasseda, X; Prous, J R
Gateways to Clinical Trials is a guide to the most recent clinical trials in current literature and congresses. The data in the following tables has been retrieved from the Clinical Studies knowledge area of Prous Science Integrity, the world's first drug discovery and development portal, and provides information on study design, treatments, conclusions and references. This issue focuses on the following selection of drugs: Abiciximab, acetylcholine chloride, acetylcysteine, alefacept, alemtuzumab, alicaforsen, alteplase, aminopterin, amoxicillin sodium, amphotericin B, anastrozole, argatroban monohydrate, arsenic trioxide, aspirin, atazanavir, atorvastatin, augmerosen, azathioprine; Benzylpenicillin, BMS-284756, botulinum toxin type A, botulinum toxin type B, BQ-123, budesonide, BXT-51072; Calcium folinate, carbamazepine, carboplatin, carmustine, ceftriaxone sodium, cefuroxime axetil, chorionic gonadotropin (human), cimetidine, ciprofloxacin hydrochloride, cisplatin, citalopram hydrobromide, cladribine, clarithromycin, clavulanic acid, clofarabine, clopidogrel hydrogensulfate, clotrimazole, CNI-1493, colesevelam hydrochloride, cyclophosphamide, cytarabine; Dalteparin sodium, daptomycin, darbepoetin alfa, debrisoquine sulfate, dexrazoxane, diaziquone, didanosine, docetaxel, donezepil, doxorubicin hydrochloride liposome injection, DX-9065a; Eberconazole, ecogramostim, eletriptan, enoxaparin sodium, epoetin, epoprostenol sodium, erlizumab, ertapenem sodium, ezetimibe; Fampridine, fenofibrate, filgrastim, fluconazole, fludarabine phosphate, fluorouracil, 5-fluorouracil/epinephrine, fondaparinux sodium, formoterol fumarate; Gabapentin, gemcitabine, gemfibrozil, glatiramer; Heparin sodium, homoharringtonine; Ibuprofen, iloprost, imatinib mesilate, imiquimod, interferon alpha-2b, interferon alpha-2c, interferon-beta; KW-6002; Lamotrigine, lanoteplase, metoprolol tartrate, mitoxantrone hydrochloride; Naproxen sodium, naratriptan, Natalizumab, nelfinavir mesilate, nevirapine, nifedipine, NSC-683864; Oral heparin; Paclitaxel, peginterferon alfa-2b, phenytoin, pimecrolimus, piperacillin, pleconaril, pramipexole hydrochloride, prednisone, pregabalin, progesterone; Rasburicase, ravuconazole, reteplase, ribavirin, rituximab, rizatriptan, rosiglitazone maleate, rotigotine; Semaxanib, sildenafil citrate, simvastatin, stavudine, sumatriptan; Tacrolimus, tamoxifen citrate, tanomastat, tazobactam, telithromycin, tenecteplase, tolafentrine, tolterodine tartrate, triamcinolone acetonide, trimetazidine, troxacitabine; Valproic acid, vancomycin hydrochloride, vincristine, voriconazole, Warfarin sodium; Ximelagatran, Zidovudine, zolmitriptan. PMID:12087878
Antibiotic Selection of Escherichia coli Sequence Type 131 in a Mouse Intestinal Colonization Model
L°bner-Olesen, Anders; Frimodt-M°ller, Niels
The ability of different antibiotics to select for extended-spectrum ?-lactamase (ESBL)-producing Escherichia coli remains a topic of discussion. In a mouse intestinal colonization model, we evaluated the selective abilities of nine common antimicrobials (cefotaxime, cefuroxime, dicloxacillin, clindamycin, penicillin, ampicillin, meropenem, ciprofloxacin, and amdinocillin) against a CTX-M-15-producing E. coli sequence type 131 (ST131) isolate with a fluoroquinolone resistance phenotype. Mice (8 per group) were orogastrically administered 0.25 ml saline with 108 CFU/ml E. coli ST131. On that same day, antibiotic treatment was initiated and given subcutaneously once a day for three consecutive days. CFU of E. coli ST131, Bacteroides, and Gram-positive aerobic bacteria in fecal samples were studied, with intervals, until day 8. Bacteroides was used as an indicator organism for impact on the Gram-negative anaerobic population. For three antibiotics, prolonged colonization was investigated with additional fecal CFU counts determined on days 10 and 14 (cefotaxime, dicloxacillin, and clindamycin). Three antibiotics (cefotaxime, dicloxacillin, and clindamycin) promoted overgrowth of E. coli ST131 (P < 0.05). Of these, only clindamycin suppressed Bacteroides, while the remaining two antibiotics had no negative impact on Bacteroides or Gram-positive organisms. Only clindamycin treatment resulted in prolonged colonization. The remaining six antibiotics, including ciprofloxacin, did not promote overgrowth of E. coli ST131 (P > 0.95), nor did they suppress Bacteroides or Gram-positive organisms. The results showed that antimicrobials both with and without an impact on Gram-negative anaerobes can select for ESBL-producing E. coli, indicating that not only Gram-negative anaerobes have a role in upholding colonization resistance. Other, so-far-unknown bacterial populations must be of importance for preventing colonization by incoming E. coli. PMID:25092712
Antibiotic Susceptibility Pattern of ES?L Producing Klebsiella pneumoniae Isolated from Urine Samples of Pregnant Women in Karnataka
N G, Manjula; C Math, Girish; Nagshetty, Kavita; Patil, Shripad A; Gaddad, Subhashchandra M
Background: Klebsiella pneumoniae possess a new problem to health care professionals worldwide, which complicates and limits therapeutic options. It is one of the leading nosocomial bacterial pathogens, and the present study aims to determine the prevalence of ES?L producing K. pneumoniae isolates with their antibiotic susceptibility pattern in urine samples of the pregnant women with UTI. Materials and Methods: Using standard isolation and identification procedures a total of 41 isolates were obtained from 417 midstream urine samples of pregnant women with suspected UTI in Karnataka. The antibiotic resistance profile of each isolate was performed by Kirby-Bauer disc diffusion method and ES?L production by standard phenotypic method. Results: Isolation rate of K. pneumoniae in pregnant women was 19.9% and overall incidence rate was 9.8%. Among the 41 K. pneumoniae isolates, 26 (63.4%) were ES?L producers and all were found to be Multi Drug Resistance (MDR). The antibiotic susceptibility test (AST) for the isolates revealed that the highest number of K. pneumoniae were resistant to ampicillin (75.6%) followed by, nitrofurontoin and cefuroxime (73.1%) and least to chloramphenicol (12.1%). ES?L producers were highly resistance to nitrofurontoin (69.2%) and cotrimonazole (65.2%) and lower resistance was (7.6%) to amaikacin, observed. A higher resistance pattern to these two antibiotics was observed against ES?L non producing K. pneumonia but lowest to polymyxin B (13.3%) instead of amikacin (26.6%). All the isolates were found to be susceptible to imipenem. Conclusion: Present investigation revealed high prevalence of MDR- ES?L producing Klebsiella pneumoniae, which indicates dire need for effective ES?L surveillance in the community by using cost effective antimicrobials agents. PMID:25478341
Antimicrobial resistance of Campylobacter jejuni and Campylobacter coli from poultry in Italy.
Giacomelli, Martina; Salata, Cristiano; Martini, Marco; Montesissa, Clara; Piccirillo, Alessandra
This study was aimed at assessing the antimicrobial resistance (AMR) of Campylobacter isolates from broilers and turkeys reared in industrial farms in Northern Italy, given the public health concern represented by resistant campylobacters in food-producing animals and the paucity of data about this topic in our country. Thirty-six Campylobacter jejuni and 24 Campylobacter coli isolated from broilers and 68 C. jejuni and 32 C. coli from turkeys were tested by disk diffusion for their susceptibility to apramycin, gentamicin, streptomycin, cephalothin, cefotaxime, ceftiofur, cefuroxime, ampicillin, amoxicillin+clavulanic acid, nalidixic acid, flumequine, enrofloxacin, ciprofloxacin, erythromycin, tilmicosin, tylosin, tiamulin, clindamycin, tetracycline, sulfamethoxazole+trimethoprim, chloramphenicol. Depending on the drug, breakpoints provided by Comitķ de l'antibiogramme de la Sociķtķ Franńaise de Microbiologie, Clinical and Laboratory Standards Institute, and the manufacturer were followed. All broiler strains and 92% turkey strains were multidrug resistant. Very high resistance rates were detected for quinolones, tetracycline, and sulfamethoxazole+trimethoprim, ranging from 65% to 100% in broilers and from 74% to 96% in turkeys. Prevalence of resistance was observed also against ampicillin (97% in broilers, 88% in turkeys) and at least three cephalosporins (93-100% in broilers, 100% in turkeys). Conversely, no isolates showed resistance to chloramphenicol and tiamulin. Susceptibility prevailed for amoxicillin+clavulanic acid and aminoglycosides in both poultry species, and for macrolides and clindamycin among turkey strains and among C. jejuni from broilers, whereas most C. coli strains from broilers (87.5%) were resistant. Other differences between C. jejuni and C. coli were observed markedly in broiler isolates, with the overall predominance of resistance in C. coli compared to C. jejuni. This study provides updates and novel data on the AMR of broiler and turkey campylobacters in Italy, revealing the occurrence of high resistance to several antimicrobials, especially key drugs for the treatment of human campylobacteriosis, representing a potential risk for public health. PMID:24320689
pspK gene prevalence and characterization of non-typable Streptococcus pneumonia isolates from Asian countries.
Na, In Young; Baek, Jin Yang; Park, In Ho; Kim, Dae Hun; Song, Jae-Hoon; Ko, Kwan Soo
Recently, it has been reported that some non-typable (NT) Streptococcus pneumoniae isolates from Korea and other countries contained a novel gene pspK in the capsular polysaccharide synthesis (cps) locus. In this study, we investigated the presence of pspK in 120 NT S. pneumoniae isolates from 12 Asian countries; isolate characteristics were also examined. The presence of pspK was assayed by PCR. Clonality of NT S. pneumoniae isolates containing pspK was investigated by MLST and PFGE. Antimicrobial susceptibility testing was performed and the structure of pspK was also determined. Nineteen NT isolates (15.8?%) were identified as containing pspK: two isolates from Korea, four from Vietnam, two from Hong Kong, eight from Thailand, and one each from Taiwan, the Philippines and Saudi Arabia. Seven isolates from Korea, Vietnam and Thailand were identified as ST1106, whereas just one or two belonged to ST310, ST393, ST10137, ST2754 or ST4136. All but one of the ST1106 NT isolates showed non-susceptibility to penicillin, and all isolates were resistant to cefuroxime, erythromycin, clindamycin and trimethoprim/sulfamethoxazole. The structure of pspK was similar amongst 20 isolates, which had a R1-R2-like region and a variable number of repeats in the repetitive region. However, one isolate (P05-11) from the Philippines lacked the R1-R2 region. NT S. pneumoniae isolates containing pspK were distributed across several Asian countries. Although MLST analysis suggested that most pspK-containing NT S. pneumoniae isolates may have emerged independently, ST1106 isolates with the selective advantage of antimicrobial resistance may have disseminated clonally throughout the countries. PMID:25750083
Combination of essential oils and antibiotics reduce antibiotic resistance in plasmid-conferred multidrug resistant bacteria.
Yap, Polly Soo Xi; Lim, Swee Hua Erin; Hu, Cai Ping; Yiap, Beow Chin
In this study we investigated the relationship between several selected commercially available essential oils and beta-lactam antibiotics on their antibacterial effect against multidrug resistant bacteria. The antibacterial activity of essential oils and antibiotics was assessed using broth microdilution. The combined effects between essential oils of cinnamon bark, lavender, marjoram, tea tree, peppermint and ampicillin, piperacillin, cefazolin, cefuroxime, carbenicillin, ceftazidime, meropenem, were evaluated by means of the checkerboard method against beta-lactamase-producing Escherichia coli. In the latter assays, fractional inhibitory concentration (FIC) values were calculated to characterize interaction between the combinations. Substantial susceptibility of the bacteria toward natural antibiotics and a considerable reduction in the minimum inhibitory concentrations (MIC) of the antibiotics were noted in some paired combinations of antibiotics and essential oils. Out of 35 antibiotic-essential oil pairs tested, four of them showed synergistic effect (FIC?0.5) and 31 pairs showed no interaction (FIC>0.5-4.0). The preliminary results obtained highlighted the occurrence of a pronounced synergistic relationship between piperacillin/cinnamon bark oil, piperacillin/lavender oil, piperacillin/peppermint oil as well as meropenem/peppermint oil against two of the three bacteria under study with a FIC index in the range 0.26-0.5. The finding highlighted the potential of peppermint, cinnamon bark and lavender essential oils being as antibiotic resistance modifying agent. Reduced usage of antibiotics could be employed as a treatment strategy to decrease the adverse effects and possibly to reverse the beta-lactam antibiotic resistance. PMID:23537749
Effect of hyperproduction of TEM-1 beta-lactamase on in vitro susceptibility of Escherichia coli to beta-lactam antibiotics.
Wu, P J; Shannon, K; Phillips, I
The susceptibility of 173 TEM-1-producing isolates of Escherichia coli was assessed by determination of MICs by the agar dilution method. MICs of amoxicillin, mezlocillin, cephaloridine, and, to a smaller extent, amoxicillin-clavulanic acid (but not cephalexin, cefuroxime, cefotaxime, ceftazidime, or imipenem) were higher for isolates that produced large amounts of beta-lactamase than for isolates that produced smaller amounts. The effect of fixed concentrations of clavulanic acid on resistance to amoxicillin was assessed for 34 selected TEM-1-producing isolates. Low concentrations of the inhibitor (0.5 to 1 microgram/ml) reduced the amoxicillin MICs substantially for almost all the isolates, although the reductions were not sufficient to render any of the isolates amoxicillin susceptible. Higher concentrations of clavulanic acid had progressively greater effects on amoxicillin MICs, but even at 8 micrograms/ml some of the isolates with high beta-lactamase activities remained resistant or only moderately susceptible to amoxicillin. All the isolates were inhibited by clavulanic acid (in the absence of amoxicillin) at concentrations of 16 to 32 micrograms/ml. TEM-1 beta-lactamase activity was inhibited in vitro by clavulanic acid, but not totally, with approximately 2% of the initial activity remaining at 2 micrograms/ml and 0.4% remaining at 8 micrograms/ml. These findings suggest that the amount of beta-lactamase activity is a major determinant of the degree of resistance to several beta-lactam antibiotics and can make the difference between susceptibility and resistance to some compounds, notably the combination of amoxicillin with clavulanic acid. PMID:8203843
Diverse modulation of spa transcription by cell wall active antibiotics in Staphylococcus aureus
Background The aim of this study was to investigate the effect of various classes of clinically relevant antibiotics at sub-lethal concentrations on virulence gene expression and biofilm formation in Staphylococcus aureus. Findings LacZ promoter fusions of genes related to staphylococcal virulence were used to monitor the effects of antibiotics on gene expression in a disc diffusion assay. The selected genes were hla and spa encoding ?-hemolysin and Protein A, respectively and RNAIII, the effector molecule of the agr quorum sensing system. The results were confirmed by quantitative real-time PCR. Additionally, we monitored the effect of subinhibitory concentrations of antibiotics on the ability of S. aureus to form biofilm in a microtiter plate assay. The results show that sub-lethal antibiotic concentrations diversely modulate expression of RNAIII, hla and spa. Consistently, expression of all three genes were repressed by aminoglycosides and induced by fluoroquinolones and penicillins. In contrast, the ?-lactam sub-group cephalosporins enhanced expression of RNAIII and hla but diversely affected expression of spa. The compounds cefalotin, cefamandole, cefoxitin, ceftazidime and cefixine were found to up-regulate spa, while down-regulation was observed for cefuroxime, cefotaxime and cefepime. Interestingly, biofilm assays demonstrated that the spa-inducing cefalotin resulted in less biofilm formation compared to the spa-repressing cefotaxime. Conclusions We find that independently of the cephalosporin generation, cephalosporins oppositely regulate spa expression and biofilm formation. Repression of spa expression correlates with the presence of a distinct methyloxime group while induction correlates with an acidic substituted oxime group. As cephalosporines target the cell wall penicillin binding proteins we speculate that subtle differences in this interaction fine-tunes spa expression independently of agr. PMID:22920188
Antibiotic resistance and molecular typing among cockle (Anadara granosa) strains of Vibrio parahaemolyticus by polymerase chain reaction (PCR)-based analysis.
Sahilah, A M; Laila, R A S; Sallehuddin, H Mohd; Osman, H; Aminah, A; Ahmad Azuhairi, A
Genomic DNA of Vibrio parahaemolyticus were characterized by antibiotic resistance, enterobacterial repetitive intergenic consensus-polymerase chain reaction (ERIC-PCR) and random amplified polymorphic DNA-polymerase chain reaction (RAPD-PCR) analysis. These isolates originated from 3 distantly locations of Selangor, Negeri Sembilan and Melaka (East coastal areas), Malaysia. A total of 44 (n = 44) of tentatively V. parahaemolyticus were also examined for the presence of toxR, tdh and trh gene. Of 44 isolates, 37 were positive towards toxR gene; while, none were positive to tdh and trh gene. Antibiotic resistance analysis showed the V. parahaemolyticus isolates were highly resistant to bacitracin (92%, 34/37) and penicillin (89%, 33/37) followed by resistance towards ampicillin (68%, 25/37), cefuroxime (38%, 14/37), amikacin (6%, 2/37) and ceftazidime (14%, 5/37). None of the V. parahaemolyticus isolates were resistant towards chloramphenicol, ciprofloxacin, ceftriaxone, enrofloxacin, norfloxacin, streptomycin and vancomycin. Antibiogram patterns exhibited, 9 patterns and phenotypically less heterogenous when compared to PCR-based techniques using ERIC- and RAPD-PCR. The results of the ERIC- and RAPD-PCR were analyzed using GelCompare software. ERIC-PCR with primers ERIC1R and ERIC2 discriminated the V. parahaemolyticus isolates into 6 clusters and 21 single isolates at a similarity level of 80%. While, RAPD-PCR with primer Gen8 discriminated the V. parahaemolyticus isolates into 11 clusters and 10 single isolates and Gen9 into 8 clusters and 16 single isolates at the same similarity level examined. Results in the presence study demonstrated combination of phenotypically and genotypically methods show a wide heterogeneity among cockle isolates of V. parahaemolyticus. PMID:24068534
Bacteriological study of paediatric and adult chronic suppurative otitis media.
Saini, Santosh; Gupta, Naveen; Aparna; Seema; Sachdeva, O P
Chronic suppurative otitis media (CSOM) is one of the commonest illnesses in ENT practice which requires medical attention all the more in children of poor socio-economic status having in past inadequate treatment and negligent medical care. The present study was conducted to find out the various aerobic and anaerobic microorganisms associated with CSOM in paediatric and adult cases and their current antimicrobial susceptibility pattern as a guide to therapy. Samples were collected from 109 clinically diagnosed cases of CSOM and processed according to standard protocols. Out of 74 paediatric CSOM cases, 72 (97.2%) were bacterial culture positive while out of 35 adult CSOM cases, 28 (80%) were culture positive. Bilateral CSOM was slightly more common in adults (25%) than paediatric (21.4%) age group. Polymicrobial nature of CSOM was noted in both paediatric (70.8%) and adult (71.4%) cases while number of organisms isolated per lesion was slightly higher in adults (2.5) as compared to paediatric (1.95) cases. In paediatric CSOM, Staphylococcus aureus was the commonest aerobic isolate while in adult CSOM, Pseudomonas aeruginosa was the commonest one. Among anaerobes Peptostreptococcus spp. was commonest in CSOM where as Prevotella melaninogenica in adult CSOM. Sensitivity of S. aureus to cefuroxime was 72.2% while that of gram negative bacilli was higher to cefotaxime (90 to 100%). Among anaerobes higher sensitivity was seen to metronidazole (98.6%), clindamycin (95.7%) and chloramphenicol (98.6%). In view of the polymicrobial etiology of CSOM, prompt appropriate antimicrobial therapy can effectively reverse the disease process thereby preventing longterm sequelae. PMID:16761774
Antibiogram of Stenotrophomonas maltophilia Isolated From Nkonkobe Municipality, Eastern Cape Province, South Africa
Adegoke, Anthony Ayodeji; Okoh, Anthony I.
Background: Assessment of resistance genes is imperative, as they become disseminated to bacterial flora in plants and to the indigenous bacterial community, and thus ultimately contributes to the clinical problems of antibiotic resistant pathogens. Objectives: The research was to assess the antibiotic characteristics and incidence of sul3 genes of Stenotrophomonas maltophilia isolates recovered from rhizospheres plant in Nkonkobe Municipality. Materials and Methods: Identification and assessment of resistance genes (sul2 and sul3 genes) were carried out using polymerase chain reaction (PCR). Analytical profile index (API) was used for biochemical characterization for identification before the PCR. Antibiotic susceptibility test was carried out using the approved guidelines and standards of Clinical Laboratory Standard Institute (CLSI). Results: A total of 125 isolates were identified, composed of 120 (96%) from grass root rhizosphere and 5 (4%) from soil butternut root rhizosphere. In vitro antibiotic susceptibility tests showed varying resistances to meropenem (8.9%), cefuroxime (95.6 %), ampicillin-sulbactam (53.9%), ceftazidime (10.7%), cefepime (29.3 %), minocycline (2.2%), kanamycin (56.9%), ofloxacin (2.9%), levofloxacin (1.3%), moxifloxacin (2.8%), ciprofloxacin (24.3%), gatifloxacin (1.3%), polymyxin B (2.9 %), cotrimoxazole (26.1%), trimethoprim (98.6%) and aztreonam (58%). The isolates were susceptible to the fluoroquinolones (74.3-94.7%), polymycin (97.1%) and meropenem (88.1%). The newest sulphonamide resistance gene, sul3, was detected among the trimethoprim-sulfamethoxazole (cotrimoxazole)-resistant isolates, while the most frequent sulphonamide-resistant gene in animal source isolates, sul2, was not. Conclusions: The commensal S. maltophilia isolates in the Nkonkobe Municipality environment harbored the resistant gene sul3 as clinical counterparts, especially from the perspective of reservoirs of antibiotic resistance determinants. PMID:25789125
Risk of AKI with Gentamicin as Surgical Prophylaxis
Davey, Peter; Nathwani, Dilip; Marwick, Charis; Vadiveloo, Thenmalar; Sneddon, Jacqueline; Patton, Andrea; Bennie, Marion; Fleming, Stewart; Donnan, Peter T.
In 2009, the Scottish government issued a target to reduce Clostridium difficile infection by 30% in 2 years. Consequently, Scottish hospitals changed from cephalosporins to gentamicin for surgical antibiotic prophylaxis. This study examined rates of postoperative AKI before and after this policy change. The study population comprised 12,482 adults undergoing surgery (orthopedic, urology, vascular, gastrointestinal, and gynecology) with antibiotic prophylaxis between October 1, 2006, and September 30, 2010 in the Tayside region of Scotland. Postoperative AKI was defined by the Kidney Disease Improving Global Outcomes criteria. The study design was an interrupted time series with segmented regression analysis. In orthopedic patients, change in policy from cefuroxime to flucloxacillin (two doses of 1 g) and single-dose gentamicin (4 mg/kg) was associated with a 94% increase in AKI (P=0.04; 95% confidence interval, 93.8% to 94.3%). Most patients who developed AKI after prophylactic gentamicin had stage 1 AKI, but some patients developed persistent stage 2 or stage 3 AKI. The antibiotic policy change was not associated with a significant increase in AKI in the other groups. Regardless of antibiotic regimen, however, rates of AKI were high (24%) after vascular surgery, and increased steadily after gastrointestinal surgery. Rates could only be ascertained in 52% of urology patients and 47% of gynecology patients because of a lack of creatinine testing. These results suggest that gentamicin should be avoided in orthopedic patients in the perioperative period. Our findings also raise concerns about the increasing prevalence of postoperative AKI and failures to consistently measure postoperative renal function. PMID:24876113
Direct susceptibility testing by disk diffusion on clinical samples: a rapid and accurate tool for antibiotic stewardship.
Coorevits, L; Boelens, J; Claeys, G
We compared the accuracy of direct susceptibility testing (DST) with conventional antimicrobial susceptibility testing (AST), both using disk diffusion, on clinical samples. A total of 123 clinical samples (respiratory tract samples, urine, vaginal and abdominal abscess discharges, bile fluid and a haematoma punctate) were selected on various indications; direct inoculation on Mueller-Hinton agar and antibiotic paper disks were applied. In parallel, standard culture, identification and AST on the colonies grown overnight was executed. Both AST and DST were interpreted after identification of the isolates. The results from both AST and DST for 11 antibiotics tested on 97 samples with Gram-negative rods showed 93.4Ā% total agreement, 1.6Ā% minor discordances, 4.6Ā% major discordances and 0.4Ā% very major discordances. Analysing the discordant results, DST predominantly resulted in more resistant isolates than AST. This was mostly due to the presence of resistant mutants or an additional isolate. The remaining discordances were seen for isolates with inhibition zones close to the clinical breakpoint. For the 26 samples yielding staphylococci, a total agreement of 100Ā% was observed for the nine antibiotics tested. Overall, the highest percentage of discordant results occurred for the ?-lactam antibiotics amoxicillin-clavulanate (13.4Ā%) and cefuroxime (12.4Ā%). When used selectively and interpreted carefully, DST on clinical samples is potentially very useful in the management of critically ill patients, as the time to results is shortened by approximately 24Āh. However, we recommend to communicate results with reservations and confirm by conventional AST. PMID:25698312
A Mutation of the RNA Polymerase ?? Subunit (rpoC) Confers Cephalosporin Resistance in Bacillus subtilis
Lee, Yong Heon; Nam, Ki Hyun
In bacteria, mutations affecting the major catalytic subunits of RNA polymerase (encoded by rpoB and rpoC) emerge in response to a variety of selective pressures. Here we isolated a Bacillus subtilis strain with high-level resistance to cefuroxime (CEF). Whole-genome resequencing revealed only one missense mutation affecting an invariant residue in close proximity to the C-terminal DNA-binding domain of RpoC (G1122D). Genetic reconstruction experiments demonstrate that this substitution is sufficient to confer CEF resistance. The G1122D mutation leads to elevated expression of stress-responsive regulons, including those of extracytoplasmic function (ECF) ? factors (?M, ?W, and ?X) and the general stress ? factor (?B). The increased CEF resistance of the rpoCG1122D strain is lost in the sigM rpoCG1122D double mutant, consistent with a major role for ?M in CEF resistance. However, a sigM mutant is very sensitive to CEF, and this sensitivity is still reduced by the G1122D mutation, suggesting that other regulatory effects are also important. Indeed, the ability of the G1122D mutation to increase CEF resistance is further reduced in a triple mutant strain lacking three ECF ? factors (?M, ?W, and ?X), which are known from prior studies to control overlapping sets of genes. Collectively, our findings highlight the ability of mutations in RNA polymerase to confer antibiotic resistance by affecting the activity of alternative ? factors that control cell envelope stress-responsive regulons. PMID:23070162
Geographical Variation in Antibiotic-Resistant Escherichia coli Isolates from Stool, Cow-Dung and Drinking Water
Sahoo, Krushna Chandra; Tamhankar, Ashok J.; Sahoo, Soumyakanta; Sahu, Priyadarshi Soumyaranjan; Klintz, Senia Rosales; Lundborg, Cecilia StÕlsby
Little information is available on relationships between the biophysical environment and antibiotic resistance. This study was conducted to investigate the antibiotic resistance pattern of Escherichia coli isolated from child stool samples, cow-dung and drinking water from the non-coastal (230 households) and coastal (187 households) regions of Odisha, India. Susceptibility testing of E. coli isolates (n = 696) to the following antibiotics: tetracycline, ampicillin/sulbactam, cefuroxime, cefotaxime, cefixime, cotrimoxazole, amikacin, ciprofloxacin, norfloxacin and nalidixic acid was performed by the disk diffusion method. Ciprofloxacin minimum inhibitory concentration (MIC) values were determined for ciprofloxacin-resistant isolates (n = 83). Resistance to at least one antibiotic was detected in 90% or more of the E. coli isolates. Ciprofloxacin MIC values ranged from 8 to 32 Ąg/mL. The odds ratio (OR) of resistance in E. coli isolates from childrenÆs stool (OR = 3.1, 95% CI 1.18¢8.01), cow-dung (OR = 3.6, 95% CI 1.59¢8.03, P = 0.002) and drinking water (OR = 3.8, 95% CI 1.00¢14.44, P = 0.049) were higher in non-coastal compared to coastal region. Similarly, the co-resistance in cow-dung (OR = 2.5, 95% CI 1.39¢4.37, P = 0.002) and drinking water (OR = 3.2, 95% CI 1.36¢7.41, P = 0.008) as well as the multi-resistance in cow-dung (OR = 2.2, 95% CI 1.12¢4.34, P = 0.022) and drinking water (OR = 2.7, 95% CI 1.06¢7.07, P = 0.036) were also higher in the non-coastal compared to the coastal region. PMID:22690160
Beta- lactam antibiotics stimulate biofilm formation in non-typeable haemophilus influenzae by up-regulating carbohydrate metabolism.
Wu, Siva; Li, Xiaojin; Gunawardana, Manjula; Maguire, Kathleen; Guerrero-Given, Debbie; Schaudinn, Christoph; Wang, Charles; Baum, Marc M; Webster, Paul
Non-typeable Haemophilus influenzae (NTHi) is a common acute otitis media pathogen, with an incidence that is increased by previous antibiotic treatment. NTHi is also an emerging causative agent of other chronic infections in humans, some linked to morbidity, and all of which impose substantial treatment costs. In this study we explore the possibility that antibiotic exposure may stimulate biofilm formation by NTHi bacteria. We discovered that sub-inhibitory concentrations of beta-lactam antibiotic (i.e., amounts that partially inhibit bacterial growth) stimulated the biofilm-forming ability of NTHi strains, an effect that was strain and antibiotic dependent. When exposed to sub-inhibitory concentrations of beta-lactam antibiotics NTHi strains produced tightly packed biofilms with decreased numbers of culturable bacteria but increased biomass. The ratio of protein per unit weight of biofilm decreased as a result of antibiotic exposure. Antibiotic-stimulated biofilms had altered ultrastructure, and genes involved in glycogen production and transporter function were up regulated in response to antibiotic exposure. Down-regulated genes were linked to multiple metabolic processes but not those involved in stress response. Antibiotic-stimulated biofilm bacteria were more resistant to a lethal dose (10 Ąg/mL) of cefuroxime. Our results suggest that beta-lactam antibiotic exposure may act as a signaling molecule that promotes transformation into the biofilm phenotype. Loss of viable bacteria, increase in biofilm biomass and decreased protein production coupled with a concomitant up-regulation of genes involved with glycogen production might result in a biofilm of sessile, metabolically inactive bacteria sustained by stored glycogen. These biofilms may protect surviving bacteria from subsequent antibiotic challenges, and act as a reservoir of viable bacteria once antibiotic exposure has ended. PMID:25007395
Characterisation of a collection of Streptococcus pneumoniae isolates from patients suffering from acute exacerbations of chronic bronchitis: in vitro susceptibility to antibiotics and biofilm formation in relation to antibiotic efflux and serotypes/serogroups.
Vandevelde, Nathalie M; Tulkens, Paul M; Diaz Iglesias, Yvan; Verhaegen, Jan; Rodriguez-Villalobos, Hector; Philippart, Ivan; Cadrobbi, Julie; Coppens, Nathalie; Boel, An; Van Vaerenbergh, Kristien; Francart, Hugo; Vanhoof, Raymond; Liistro, Giuseppe; Jordens, Paul; d'Odemont, Jean-Paul; Valcke, Yvan; Verschuren, Franck; Van Bambeke, Franńoise
The correlation between Streptococcus pneumoniae serotypes, biofilm production, antibiotic susceptibility and drug efflux in isolates from patients suffering from acute exacerbations of chronic bronchitis (AECB) remains largely unexplored. Using 101 isolates collected from AECB patients for whom partial (n=51) or full (n=50) medical details were available, we determined serotypes (ST)/serogroups (SG) (Quellung reaction), antibiotic susceptibility patterns [MIC (microdilution) using EUCAST and CLSI criteria] and ability to produce biofilm in vitro (10-day model; crystal violet staining). The majority of patients were 55-75 years old and <5% were vaccinated against S. pneumoniae. Moreover, 54% showed high severity scores (GOLD 3-4), and comorbidities were frequent including hypertension (60%), cancer (24%) and diabetes (20%). Alcohol and/or tobacco dependence was >30%. Isolates of SG6-11-15-23, known for large biofilm production and causing chronic infections, were the most prevalent (>15% each), but other isolates also produced biofilm (SG9-18-22-27 and ST8-20 being most productive), except SG7, SG29 and ST5 (<2% of isolates each). Resistance (EUCAST breakpoints) was 8-13% for amoxicillin and cefuroxime, 35-39% for macrolides, 2-8% for fluoroquinolones and 2% for telithromycin. ST19A isolates showed resistance to all antibiotics, ST14 to all except moxifloxacin, and SG9 and SG19 to all except telithromycin, moxifloxacin and ceftriaxone (SG19 only). Solithromycin and telithromycin MICs were similar. No correlation was observed between biofilm production and MIC or efflux (macrolides, fluoroquinolones). S. pneumoniae serotyping may improve AECB treatment by avoiding antibiotics with predictable low activity, but it is not predictive of biofilm production. PMID:25123808
[Study on the drug sensitivity of multiple drug-resistant Staphylococcus aureus].
Deguchi, K; Fukayama, S; Nishimura, Y; Yokota, N; Tanaka, S; Oda, S; Matsumoto, Y; Ikegami, R; Satoh, K; Toyonaga, Y
Of clinically isolated Staphylococcus aureus showing resistance to multiple drugs among penicillins (PCs), cephem antibiotics (CEPs), aminoglycosides (AGs), minocycline (MINO) and fosfomycin (FOM), 64 strains were selected for the determination of MIC. Twenty-one drugs were used for the determination of MIC, with ampicillin (ABPC), cloxacillin (MCIPC), cephalothin (CET), cefazolin (CEZ), cefotiam (CTM), cefuroxime (CXM), cefamandole (CMD), cefotaxime (CTX), ceftizoxime (CZX), cefmenoxime (CMX), cefmetazole (CMZ), cefoxitin (CFX), latamoxef (LMOX), cefotetan (CTT), cefoperazone (CPZ), gentamicin (GM), dibekacin (DKB), tobramycin (TOB), amikacin (AMK), MINO, and FOM. MIC80 of each drug at 10(6) CFU/ml were: ABPC, MCIPC, CEZ, CTM, CXM, CTX, CZX, CMX, CFX, LMOX, CTT, CPZ, GM, DKB and TOB greater than 100 micrograms/ml; CET 50 micrograms/ml; CMD and AMK 25 micrograms/ml; CMZ 12.5 micrograms/ml; FOM 6.25 micrograms/ml; and MINO 0.78 micrograms/ml. The ratio of highly resistant strains with MIC greater than 100 micrograms/ml at 10(6) CFU/ml varied according to drug, and a difference tended to be seen in the degree of influence by resistant factors reflected upon MIC, e.g. drugs for which a high resistance of more than 50% was confirmed were ABPC, CXM, CZX, LMOX and TOB, and 20 approximately 30% MCIPC, CTM, CTX, CMX and CFX. MIC on MCIPC which has a correlation of structural activity with methicillin correlated with cephems (CEPs) resistance to a high degree, but many of the so-called new CEPs showed resistance even to the strains with a low MIC on MCIPC. It was assumed that CEPs resistant strains have multiple drug resistant factors based on the fact that such strains showed multiple drug resistance.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:3852898
Acute otitis media disease management.
Pichichero, M E; Casey, J R
A first step in management decisions regarding otitis media must focus on accurate diagnosis to distinguish normal from acute otitis media (AOM) from otitis media with effusion (OME) or a retracted tympanic membrane without middle ear effusion. There are several classification schemes for AOM that may impact management decisions: patients with acute, persistent, recurrent, or chronic AOM may have a different distribution of bacterial pathogens and a different likelihood of success from antimicrobial therapy. Patient age, prior treatment history and daycare attendance are other important variables. The natural history of AOM without antibiotic treatment is generally favorable; however, from the few studies available, this is difficult to quantitate because the diagnosis was infrequently confirmed by tympanocentesis leaving the possibility that many patients entered into these trials may not have had bacterial AOM. Antibiotic choices should reflect pharmacokinetic/pharmacodynamic data and clinical trial results demonstrating effectiveness in eradication of the most likely pathogens based on tympanocentesis sampling and antibiotic sensitivity testing. Thereafter, compliance factors such as formulation, dosing schedule and duration of treatment and accessibility factors such as availability and cost should be taken into account. The increasing prevalence of antibiotic resistance among AOM pathogens and the changing susceptibility profiles of these bacteria should be considered in antibiotic selection. Current best practice recommends amoxicillin for uncomplicated AOM; continuing or switching to an alternative antibiotic based on clinical response after 48 hours of therapy; and selection of second line antibiotics as first line choices when the patient has already been on an antibiotic within the previous month or is otitis prone. Preferred second-line agents frequently noted in various guidelines include amoxicillin/clavulanate, cefdinir, cefpodoxime, cefprozil, and cefuroxime. Three injections of ceftriaxone or gatifloxacin (when approved) or diagnostic/therapeutic tympanocentisis (when approved) become a third-line treatment option. No single antibiotic or management strategy is ideal for all patients. PMID:14608265
Relationship between antibiotic resistance and sickle cell anemia: preliminary evidence from a pediatric carriage study in Ghana
Donkor, Eric S; Foster-Nyarko, Ebenezer; Enweronu-Laryea, Christabel C
Background Antibiotics are frequently used among people with sickle cell anemia (homozygous SS or HbSS disease), especially for prophylaxis. However, the relationship between antibiotic resistance and people with HbSS disease has not been adequately studied, especially in the developing world. The objectives of the study were (1) to compare antibiotic resistance patterns of nasal Staphylococcus aureus between children with HbSS disease and children without HbSS disease (healthy children) and (2) to evaluate nasopharyngeal carriage of antibiotic-resistant Streptococcus pneumoniae among children with HbSS disease. Methods This was a prospective cross-sectional study, and the subjects were children under 12 years old. Nasal swabs were collected from 50 children with HbSS disease and 50 children without HbSS disease. Nasopharyngeal swabs were collected from another group of 92 children with HbSS disease. The nasal and nasopharyngeal swabs were cultured for S. aureus and S. pneumoniae, respectively. Susceptibility testing was carried out on the S. aureus and S. pneumoniae isolates for various antibiotics, including penicillin, ampicillin, cefuroxime, erythromycin, cloxacillin, and cotrimoxazole. Results The carriage rates of S. aureus among pediatric subjects with HbSS disease and those without HbSS disease were 48% and 50%, respectively (P > 0.05). S. pneumoniae carriage among the pediatric subjects with HbSS disease was 10%. Antibiotic resistance patterns of S. aureus carried by children with HbSS disease and children without HbSS disease were similar, and the S. aureus resistance rates were >40% for the various antibiotics, with the exception of erythromycin and cloxacillin. Low levels of S. pneumoniae resistance (0%¢11%) were observed for the various antibiotics tested except cotrimoxazole, which showed an extremely high-percentage resistance (100%). Conclusion Sickling status is not a risk factor for carriage of S. aureus. In this cohort of Ghanaian children with HbSS disease, S. aureus is higher in carriage and more antibiotic-resistant, compared to S. pneumoniae. PMID:23930075
Bacterial Bloodstream Infections in HIV-infected Adults Attending a Lagos Teaching Hospital
Sulaiman, Akanmu A.; Solomon, Bamiro B.; Chinedu, Obosi A.; Victor, Inem A.
An investigation was carried out during October 2005¢September 2006 to determine the prevalence of bloodstream infections in patients attending the outpatient department of the HIV/AIDS clinic at the Lagos University Teaching Hospital in Nigeria. Two hundred and one patientsŚ86 males and 115 femalesŚaged 14-65 years were recruited for the study. Serological diagnosis was carried out on them to confirm their HIV status. Their CD4 counts were done using the micromagnetic bead method. Twenty mL of venous blood sample collected from each patient was inoculated into a pair of Oxoid Signal blood culture bottles for 2-14 days. Thereafter, 0.1 mL of the sample was plated in duplicates on MacConkey, blood and chocolate agar media and incubated at 37 ░C for 18-24 hours. The CD4+ counts were generally low as 67% of 140 patients sampled had <200 cells/?L of blood. Twenty-six bacterial isolates were obtained from the blood samples and comprised 15 (58%) coagulase-negative staphylococci as follows: Staphylococcus epidermidis (7), S. cohnii cohnii (1), S. cohnii urealyticum (2), S. chromogenes (1), S. warneri (2), S. scuri (1), and S. xylosus (1). Others were 6 (23%) Gram-negative non-typhoid Salmonella spp., S. Typhimurium (4), S. Enteritidis (2); Pseudomonas fluorescens (1), Escherichia coli (1), Ochrobactrum anthropi (1), Moraxella sp. (1), and Chryseobacterium meningosepticum. Results of antimicrobial susceptibility tests showed that coagulase-negative staphylococci had good sensitivities to vancomycin and most other antibiotics screened but were resistant mainly to ampicilin and tetracycline. The Gram-negative organisms isolated also showed resistance to ampicillin, tetracycline, chloramphenicol, and septrin. This study demonstrates that co-agulase-negative staphylococci and non-typhoidal Salmonellae are the most common aetiological agents of bacteraemia among HIV-infected adults attending the Lagos University Teaching Hospital, Nigeria. The organisms were resistant to older-generation antibiotics often prescribed in this environment but were sensitive to vancomycin, cefotaxime, cefuroxime, and other new-generation antibiotics. PMID:20824974
Antibiotic resistance among clinical isolates of Haemophilus influenzae in the United States in 1994 and 1995 and detection of beta-lactamase-positive strains resistant to amoxicillin-clavulanate: results of a national multicenter surveillance study.
Doern, G V; Brueggemann, A B; Pierce, G; Holley, H P; Rauch, A
A total of 1,537 clinical isolates of Haemophilus influenzae were recovered in 30 U.S. medical center laboratories between 1 November 1994 and 30 April 1995 and were characterized in a central laboratory with respect to serotype and beta-lactamase production and the in vitro activities of 15 oral antimicrobial agents. Overall, 36.4% of the isolates were found to produce beta-lactamase. The rank order of activity of six cephalosporins on the basis of MICs was cefixime > cefpodoxime > cefuroxime > loracarbef > or = cefaclor > cefprozil. On the basis of current National Committee for Clinical Laboratory Standards (NCCLS) breakpoints ages of isolates found to be resistant or intermediate to these agents were as follows: 0.1, 0.3, 6.4, 16.3, 18.3, and 29.8, respectively (National Committee for Clinical Laboratory Standards. Methods for dilution antimicrobial susceptibility tests for bacteria that grow aerobically, 4th ed. M7-A4, 1995). Azithromycin was, on a weight basis, the most potent of the macrolides tested in this study, followed by erythromycin and then clarithromycin. Azithromycin was typically fourfold more active than erythromycin, which was, in turn, slightly more active than clarithromycin. However, when compared on the basis of the frequency of resistance determined by using current NCCLS breakpoints, there was essentially no difference between azithromycin and clarithromycin, i.e., 0.5 and 1.9%, respectively (P = 0.086). Interpretive breakpoints for erythromycin MIC tests versus H. influenzae have not been developed. Resistance to other non- beta-lactam agents was variable, as follows: trimethoprim-sulfamethoxazole, 9.0%; chloramphenicol, 0.2%; tetracycline, 1.3%; and rifampin, 0.3%. Two conspicuous findings in this study were the identification of 39 strains H. influenzae that were beta-lactamase negative but ampicillin intermediate or resistant (BLNAR) and, even more surprisingly, 17 beta-lactamase-positive isolates that were resistant to amoxicillin-clavulanate (BLPACR). Strains of H. influenzae in the first group have heretofore been very uncommon; organisms in the second group have not previously been described in the literature. The percentages of all study isolates comprised of BLNAR and BLPACR organisms were 2.5 and 1.1, respectively. Overall resistance to ampicillin was thus 38.9%, and that to amoxicillin-clavulanate was 4.5%. PMID:9021182
Prevalence, antimicrobial resistance and relation to indicator and pathogenic microorganisms of Salmonella enterica isolated from surface waters within an agricultural landscape.
Economou, Vangelis; Gousia, Panagiota; Kansouzidou, Athina; Sakkas, Hercules; Karanis, Panagiotis; Papadopoulou, Chrissanthy
During a 12 month period (June 2007-May 2008), the prevalence and susceptibility of Salmonella serovars and their relation to specific pathogenic and indicator bacteria in river and coastal waters was investigated. A total of 240 water samples were collected from selected sites in Acheron and Kalamas Rivers and the Ionian Sea coast in north western Greece. The samples were analyzed for Salmonella spp., Listeria spp., Campylobacter spp., Escherichia coli O157, Staphylococci, Pseudomonas spp., Total Coliforms, Fecal Coliforms, Fecal Streptococci, Total Heterotrophic Flora at 20░C and at 37░C, fungi and protozoa (Cryptosporidium, Giardia). Susceptibility tests to nine antimicrobials (ampicillin, amikacin, amoxicillin/clavulavic acid, cefuroxime, ciprofloxacin, cefoxitin, tetracycline, ticarcillin/clavulanic acid, ampicillin/sulbactam) were performed using the disk diffusion method for Salmonella isolates. We isolated 28 serovars of Salmonella spp. identified as Salmonella enteritidis (23), Salmonella thompson (3) and Salmonella virchow (2). Multi-drug resistant Salmonella serovars were isolated from both river and marine waters, with 34.8% of S. enteritidis and 100% of S. virchow being resistant to more than 3 antibiotics. Also we isolated 42 strains of Listeria spp. identified as L. monocytogenes (20), L. innocua (9), L. seeligeri (2) and L. ivanovii (11). All the Listeria isolates were susceptible to the tested antibiotics. No Campylobacter spp., E. coli O157, Cryptosporidium and Giardia were detected. The overall ranges (and average counts) of the indicator bacteria were: Total Coliforms 0-4ū10(4)cfu/100ml (3.7ū10(3)cfu/100ml), Fecal Coliforms 0-9ū10(3)cfu/100ml (9.2ū10(2)cfu/100ml), Fecal Streptococci 0-3.5ū10(4)cfu/100ml (1.4ū10(3)cfu/100ml), Total Heterotrophic Flora at 20░C 0-6ū10(3)cfu/ml (10(3)cfu/ml) and at 37░C 0-5ū10(3)cfu/ml (4.9ū10(2)cfu/ml). Weak or non significant positive Spearman correlations (p<0.05, rs range: 0.13-0.77) were obtained between Salmonella, Listeria, fungi and indicator bacteria. The results underline the complexity of the interrelations between pathogens and indicator bacteria, and the necessity to assess the presence of resistant bacteria in the aquatic environments. PMID:22901425
An In Vitro Deletion in ribE Encoding Lumazine Synthase Contributes to Nitrofurantoin Resistance in Escherichia coli
Vervoort, Jascha; Xavier, Basil Britto; Stewardson, Andrew; Coenen, Samuel; Godycki-Cwirko, Maciek; Adriaenssens, Niels; Kowalczyk, Anna; Lammens, Christine; Harbarth, Stephan; Goossens, Herman
Nitrofurantoin has been used for decades for the treatment of urinary tract infections (UTIs), but clinically significant resistance in Escherichia coli is uncommon. Nitrofurantoin concentrations in the gastrointestinal tract tend to be low, which might facilitate selection of nitrofurantoin-resistant (NIT-R) strains in the gut flora. We subjected two nitrofurantoin-susceptible intestinal E. coli strains (ST540-p and ST2747-p) to increasing nitrofurantoin concentrations under aerobic and anaerobic conditions. Whole-genome sequencing was performed for both susceptible isolates and selected mutants that exhibited the highest nitrofurantoin resistance levels aerobically (ST540-a and ST2747-a) and anaerobically (ST540-an and ST2747-an). ST540-a/ST540-an and ST2747-a (aerobic MICs of >64 ?g/ml) harbored mutations in the known nitrofurantoin resistance determinants nfsA and/or nfsB, which encode oxygen-insensitive nitroreductases. ST2747-an showed reduced nitrofurantoin susceptibility (aerobic MIC of 32 ?g/ml) and exhibited remarkable growth deficits but did not harbor nfsA/nfsB mutations. We identified a 12-nucleotide deletion in ribE, encoding lumazine synthase, an essential enzyme involved in the biosynthesis of flavin mononucleotide (FMN), which is an important cofactor for NfsA and NfsB. Complementing ST2747-an with a functional wild-type lumazine synthase restored nitrofurantoin susceptibility. Six NIT-R E. coli isolates (NRCI-1 to NRCI-6) from stools of UTI patients treated with nitrofurantoin, cefuroxime, or a fluoroquinolone harbored mutations in nfsA and/or nfsB but not ribE. Sequencing of the ribE gene in six intestinal and three urinary E. coli strains showing reduced nitrofurantoin susceptibility (MICs of 16 to 48 ?g/ml) also did not identify any relevant mutations. NRCI-1, NRCI-2, and NRCI-5 exhibited up to 4-fold higher anaerobic MICs, compared to the mutants generated in vitro, presumably because of additional mutations in oxygen-sensitive nitroreductases. PMID:25246406
Prevalence of Extended Spectrum ?-lactamase-Producing Klebsiella pneumoniae in Clinical Isolates
Ali Abdel Rahim, Khalid Abdalla; Ali Mohamed, Ahmed Mohamed
Background: Extended spectrum ?-lactamase (ESBL) are gram-negative bacteria that produce the enzyme, ?-lactamase, which can break down commonly used antibiotics, such as penicillin and cephalosporins, making infections with ESBL producing bacteria more difficult to treat. Extended spectrum ?-lactamase-producing Klebsiella pneumoniae were first reported in 1983 from Germany, and since then a steady increase in resistance against cephalosporins has been seen causing health problems. Objectives: The aim of this study was to determine the prevalence of ESBL in strains of K. pneumoniae isolated from different clinical samples. Patients and Methods: One hundred and thirty isolates of K. pneumoniae were isolated from different clinical specimens from King Khalid hospital, Hafr Elbatin, Kingdom Saudi Arabia. These isolates were then characterized, tested for antimicrobial susceptibility and screened for ESBL production by the MicroScan WalkAway-96 SI System. Extended spectrum ?-lactamase production was confirmed by the phenotypic confirmatory disc diffusion test (PCDDT) and the double disc synergy test (DDST). Results: Overall, 76.9% (100) of the isolates were resistant to cefuroxime, cefepime and cefazolin, 69.23% (90) were resistant to cefotaxime, and 46.15% (60) were resistant to cefoxitin. Extended spectrum ?-lactamase was detected in 53.8% (70) of K. pneumoniae as detected by the MicroScan ōWalkAway-96ö SI System and 50.07% (66) by PCDDT and 46.15% (60) by DDST. All K. pneumoniae isolates were resistant to ampicillin followed by both piperacillin and mezlocillin 92.30% (120). K. pneumoniae isolates showed high sensitivity to imipenem (15.38%) (20), followed by ertapenem, tetracycline, tigecycline pipracilline/tazobactam and amikacin (23.07%) (30). Conclusions: Our study showed that the prevalence of ESBL-producing K. pneumoniae at King Khalid Hospital was significantly high. Routine detection of ESBL-producing microorganisms is required by each of the laboratory standard detection methods to control the spread of these infections and allow a proper therapeutic strategy. For detection, the phenotypic confirmatory disc diffusion test is simple, sensitive and cost effective. However, there is a need for larger scale drug susceptibility surveillance. PMID:25774279
Histopathological Studies on Rabbits Infected by Bacteria Causing Infectious Keratitis in Human through Eye Inoculation
Aldebasi, Yousef H.; Mohamed, Hala A.; Aly, Salah M.
Aim This study aimed to investigate the pathogenic effect of bacteria causing infectious keratitis among patients through experimental study conducted on rabbitsÆ eyes with the aid of histopathology as eye infection is a common disease in developing countries that may complicate to loss of vision. Methodology 100 swab samples were collected from human infected eyes, at Qassim region during 2012, for the isolation of Pseudomonas aeruginosa and Staphylococcus aureus. The isolated pathogenic bacteria were tested to various antibiotics using some selected antibiotics discs through agar-well diffusion method. Then, experimental study conducted on 27 rabbits. The rabbits were divided randomly into three equal groups, each containing 9 rabbits. Rabbits of group (1) served as control group (Negative Control) and their eyes were inoculated with the buffer only. Rabbits of group (2) were inoculated through eyes with the isolated Pseudomonas aeruginosa. Rabbits of group (3) were inoculated through eyes with the isolated Staphylococcus aureus. Results Out of 100 collected swab samples from human infected eyes, Pseudomonas aeruginosa and Staphylococcus aureus were isolated with a total percentage of 25.21% and 15.65%; respectively and used in this study. Both bacterial isolates were sensitive to Gentamicin and Cefuroxime. Clinically, experimentally infected rabbits by Pseudomonas aeruginosa, revealed varying degree corneal abrasions, corneal abscess and dense corneal opacity. Histopathologically, at 3rd day post-infection (PI), the cornea revealed polymorpho-nuclear cells infiltration with loss of the outer epithelial lining. At 7th day PI, neutrophils were seen in the stroma. At 15th day PI, proliferation of fibroblasts and new vascularisation were seen in the stroma. Clinically, rabbits experimentally infected with Staphylococcus aureus, revealed corneal ulcers and focal abscesses. Histopathologically, at 3rd and 7th day PI, the cornea revealed edema and infiltration of leukocytes. At 15th day PI, hyperplasia of corneal epithelium and proliferation of keratocytes were evident. The liver and kidneys of experimented rabbits revealed no remarkable histopathological alterations along the period of experiment. Conclusion Pseudomonas aeruginosa and Staphylococcus aureus are common eye infection in human, both induced severe lesions in the eyes of rabbits that could interfere with vision, therefore, strict measures to control these infections in human is recommended. PMID:25505861
Phenotypic and genotypic antimicrobial resistance patterns of Escherichia coli isolated from dairy cows with mastitis.
Srinivasan, Velusamy; Gillespie, Barbara E; Lewis, Mark J; Nguyen, Lien T; Headrick, Susan I; Schukken, Ynte H; Oliver, Stephen P
Pulsed field gel electrophoresis (PFGE) patterns, susceptibility to 26 antimicrobial agents used in veterinary and human medicine, and prevalence of antimicrobial resistance genes of Escherichia coli isolated from cows with mastitis were evaluated. Among 135 E. coli isolates, PFGE analysis revealed 85 different genetic patterns. All E. coli were resistant to two or more antimicrobials in different combinations. Most E. coli were resistant to antimicrobials used in veterinary medicine including ampicillin (98.4%, >or=32 microg/ml) and many E. coli were resistant to streptomycin (40.3%, >or=64 microg/ml), sulfisoxazole (34.1%, >or=512 microg/ml), and tetracycline (24.8%, >or=16 microg/ml). Most E. coli were resistant to antimicrobials used in human medicine including aztreonam (97.7%, >or=32 microg/ml) and cefaclor (89.9%, >or=32 microg/ml). Some E. coli were resistant to nitrofurantoin (38%, >or=128 microg/ml), cefuroxime (22.5%, >or=32 microg/ml), fosfomycin (17.8%, >or=256 microg/ml). All E. coli were susceptible to ciprofloxacin and cinoxacin. Almost 97% (123 of 127) of ampicillin-resistant isolates carried ampC. Eleven of 52 (21.2%) streptomycin-resistant isolates carried strA, strB and aadA together and 29 streptomycin-resistant isolates (55.8%) carried aadA alone. Among 44 sulfisoxazole-resistant E. coli, 1 isolate (2.3%) carried both sulI and sulII, 12 (27.3%) carried sulI and 10 (22.7%) isolates carried sulII. Among 32 tetracycline-resistant isolates, 14 (43.8%) carried both tetA and tetC and 14 (43.8%) carried tetC. Results of this study demonstrated that E. coli from cows with mastitis were genotypically different, multidrug resistant and carried multiple resistance genes. These bacteria can be a reservoir for antimicrobial resistance genes and can play a role in the dissemination of antimicrobial resistance genes to other pathogenic and commensal bacteria in the dairy farm environment. PMID:17544234
Antimicrobial resistance patterns of Shiga toxin-producing Escherichia coli O157:H7 and O157:H7- from different origins.
Srinivasan, Velusamy; Nguyen, Lien T; Headrick, Susan I; Murinda, Shelton E; Oliver, Stephen P
Shiga toxin-producing Escherichia coli (STEC) serotypes including O157:H7 (n = 129) from dairy cows, cull dairy cow feces, cider, salami, human feces, ground beef, bulk tank milk, bovine feces, and lettuce; and O157:H7- (n = 24) isolated from bovine dairy and bovine feedlot cows were evaluated for antimicrobial resistance against 26 antimicrobials and the presence of antimicrobial resistance genes (tetA, tetB, tetC, tetD, tetE, tetG, floR, cmlA, strA, strB, sulI, sulII, and ampC). All E. coli exhibited resistance to five or more antimicrobial agents, and the majority of isolates carried one or more target antimicrobial resistance gene(s) in different combinations. The majority of E. coli showed resistance to ampicillin, aztreonam, cefaclor, cephalothin, cinoxacin, and nalidixic acid, and all isolates were susceptible to chloramphenicol and florfenicol. Many STEC O157:H7 and O157:H7-isolates were susceptible to amikacin, carbenicillin, ceftriaxone, cefuroxime, ciprofloxacin, fosfomycin, moxalactam, norfloxacin, streptomycin, tobramycin, trimethoprim, and tetracycline. The majority of STEC O157:H7 (79.8%) and O157:H7- (91.7%) carried one or more antimicrobial resistance gene(s) regardless of whether phenotypically resistant or susceptible. Four tetracycline resistant STEC O157:H7 isolates carried both tetA and tetC. Other tetracycline resistance genes (tetB, tetD, tetE, and tetG) were not detected in any of the isolates. Among nine streptomycin resistant STEC O157:H7 isolates, eight carried strA-strB along with aadA, whereas the other isolate carried aadA alone. However, the majority of tetracycline and streptomycin susceptible STEC isolates also carried tetA and aadA genes, respectively. Most ampicillin resistant E. coli of both serotypes carried ampC genes. Among sulfonamide resistance genes, sulII was detected only in STEC O157:H7 (4 of 80 sulfonamide-resistant isolates) and sulI was detected in O157:H7- (1 of 16 sulfonamide resistant isolates). The emergence and dissemination of multidrug resistance in STEC can serve as a reservoir for different antimicrobial resistance genes. Dissemination of antimicrobial resistance genes to commensal and pathogenic bacteria could occur through any one of the horizontal gene transfer mechanisms adopted by the bacteria. PMID:17536933
Prevalence, Pathogenesis, Antibiotic Susceptibility Profiles, and In-vitro Activity of Selected Medicinal Plants Against Aeromonas Isolates from Stool Samples of Patients in the Venda Region of South Africa
Obi, C.L.; Ramalivhana, J.; Samie, A.; Igumbor, E.O.
The prevalence, pathogenic indices, such as haemolytic and haemagglutinating activities, antibiograms, and in-vitro activities of local medicinal plants against Aeromonas isolates in Vhembe district of Limpopo province, South Africa, were studied using standard microbiological methods. In total, 309 diarrhoeic stool samples were collected from patients attending five health centres in the region during December 2004¢May 2005. Aeromonas species were identified using the API 20E system. The haemagglutinating and haemolytic activities of isolates on human, sheep, pig and chicken red blood cells were investigated. Antibiotic susceptibility profiles of the isolates to several antibiotics and in-vitro activity of local medicinal plants were also ascertained using previously-reported schemes. Results showed that 104 (33.6%) of the 309 samples were positive for Aeromonas species, of which 89 (85.6%) were Aeromonas hydrophila, 12 (11.5%) A. sobria, and three (2.9%) A. caviae. All strains of A. hydrophila and A. caviae produced haemolysis on sheep blood, while eight of the 12 A. sobria strains were haemolytic on sheep blood. The haemolytic activities of the isolates were variable on other red blood cells tested. High level of resistance was observed to amoxicillin and ampicillin, followed by cefuroxime (79%), chloramphenicol (74%), and erythromycin (65%). The carbapenems were the most active drugs with only 7% resistance to meropenem and 11% to imipenem. About 12% of the isolates were resistant to ciprofloxacin. The extracts of three of seven medicinal plants tested showed inhibitory activity against all Aeromonas isolates; these included acetone and hexane extracts of Pterocarpus angolensis, Syzygium cordatum, and Zornia milneana. The results suggest a high prevalence of Aeromonas species in the region. The isolates demonstrated multiple resistant profiles to different antibiotics tested. Some local medicinal plants were inhibitory to Aeromonas isolates, indicating a potential role in the management of Aeromonas-related infections. Structural elucidation of the active components may pave the way for the discovery of candidate templates for eventual drug design. Most isolates possessed important virulence characteristics based on their haemolytic and haemagglutinating ability. However, the genetic characterization of the isolates will further confirm their pathogenicity and the origin of multiple antibiotic resistance. PMID:18402186
Tonsillitis and sore throat in children
Stelter, Klaus
Surgery of the tonsils is still one of the most frequent procedures during childhood. Due to a series of fatal outcomes after hemorrhage in children in Austria in 2006, the standards and indications for tonsillectomy have slowly changed in Germany. However, no national guidelines exist and the frequency of tonsil surgery varies across the country. In some districts eight times more children were tonsillectomized than in others. A tonsillectomy in children under six years should only be done if the child suffers from recurrent acute bacterially tonsillitis. In all other cases (i.e. hyperplasia of the tonsils) the low risk partial tonsillectomy should be the first line therapy. Postoperative pain and the risk of hemorrhage are much lower in partial tonsillectomy (=tonsillotomy). No matter whether the tonsillotomy is done by laser, radiofrequency, shaver, coblation, bipolar scissor or Colorado needle, as long as the crypts are kept open and some tonsil tissue is left behind. Total extracapsular tonsillectomy is still indicated in severely affected children with recurrent infections of the tonsils, allergy to antibiotics, PFAPA syndrome (periodic fever, aphthous stomatitis, pharyngitis, and cervical adenitis) and peritonsillar abscess. With regard to the frequency and seriousness of the recurrent tonsillitis the indication for tonsillectomy in children is justified if 7 or more well-documented, clinically important, adequately treated episodes of throat infection occur in the preceding year, or 5 or more of such episodes occur in each of the 2 preceding years (according to the paradise criteria). Diagnosis of acute tonsillitis is clinical, but sometimes it is hard to distinguish viral from bacterial infections. Rapid antigen testing has a very low sensitivity in the diagnosis of bacterial tonsillitis and swabs are highly sensitive but take a long time. In all microbiological tests the treating physician has to keep in mind, that most of the bacterials, viruses and fungi belong to the healthy flora and do no harm. Ten percent of healthy children even bear strepptococcus pyogenes all the time in the tonsils with no clinical signs. In these children decolonization is not necessary. Therefore, microbiological screening tests in children without symptoms are senseless and do not justify an antibiotic treatment (which is sometimes postulated by the kindergartens). The acute tonsillitis should be treated with steroids (e.g. dexamethasone), NSAIDs (e.g. ibuprofene) and betalactam antibiotics (e.g. penicillin or cefuroxime). With respect to the symptom reduction and primary healing the short-term late-generation antibiotic therapy (azithromycin, clarithromycin or cephalosporine for three to five days) is comparable to the long-term penicilline therapy. There is no difference in the course of healing, recurrence or microbiological resistance between the short-term penicilline therapy and the standard ten days therapy. On the other hand, only the ten days antibiotic therapy has proven to be effective in the prevention of rheumatic fever and glomerulonephritic diseases. The incidence of rheumatic heart disease is currently 0.5 per 100,000 children of school age. The main morbidity after tonsillectomy is pain and the late haemorrhage. Posttonsillectomy bleeding can occur till the whole wound is completely healed, which is normally after three weeks. Life-threatening haemorrhages occur often after smaller bleedings, which can spontaneously cease. That is why every haemorrhage, even the smallest, has to be treated properly and in ward. Patients and parents have to be informed about the correct behaviour in case of haemorrhage with a written consent before the surgery. The handout should contain important addresses, phone numbers and contact persons. Almost all cases of fatal outcome after tonsillectomy were due to false management of haemorrhage. Haemorrhage in small children can be especially life-threatening because of the lower blood volume and the danger of aspiration with asphyxia. A massive haemorrhage is an extreme challenge for eve
[Tonsillitis and sore throat in childhood].
Stelter, K
Surgery of the tonsils is still one of the most frequent procedures during childhood. Due to a series of fatal outcome after hemorrhage in children in Austria in 2006, the standards and indications for tonsillectomy slowly change in Germany since that. However, there exist no national guidelines and the frequency of tonsil surgery varies in the country. In some districts eight times more children were tonsillectomized than in others. A tonsillectomy in children under 6 years should only be done if the child suffers from recurrent acute bacterially tonsillitis. In all other cases (i. e. hyperplasia of the tonsils) the low risk partial tonsillectomy should be the first line therapy. Postoperative pain and the risk of hemorrhage are much lower in partial tonsillectomy (=?tonsillotomy). No matter whether the tonsillotomy is done by laser, radiofrequency, shaver, coblation, bipolar scissor or Colorado needle, as long as the crypts are kept open and some tonsil tissue is left behind. Total extracapsular tonsillectomy is still indicated in severely affected children with recurrent infections of the tonsils, allergy to antibiotics, PFAPA syndrome (periodic fever, aphthous stomatitis, pharyngitis, and cervical adenitis) and peritonsillar abscess. With regard to the frequency and seriousness of the recurrent tonsillitis the indication for tonsillectomy in children is justified if 7 or more well-documented, clinically important, adequately treated episodes of throat infection occur in the preceding year, or 5 or more such episodes occur in each of the 2 preceding years (according to the paradise criteria). Diagnosis of acute tonsillitis is clinical, but sometimes it is hard to distinguish viral from bacterial infections. Rapid antigen testing has a very low sensitivity in the diagnosis of bacterial tonsillitis and swabs are highly sensitive but take a long time. In all microbiological tests the treating physician has to keep in mind, that most of the bacterials, viruses and fungi belong to the healthy flora and do no harm. Ten percent of the healthy children bear even streptococcus pyogenes all the time in the tonsils with no clinical signs. In these children decolonization is not necessary. Therefore, microbiological screening tests in children without symptoms are senseless and do not justify an antibiotic treatment (which is sometimes postulated by the kindergartens). The acute tonsillitis should be treated with steroids (e.g. dexamethasone), NSAIDs (e.g. ibuprofene) and betalactam antibiotics (e.g. penicillin or cefuroxime). With respect to the symptom reduction and primary healing the short-term late-generation antibiotic therapy (azithromycin, clarithromycin or cephalosporine for 3 to 5 days) is comparable to the long-term penicilline therapy. There is no difference in the course of healing, recurrence or microbiological resistance between the short-term penicilline therapy to the standard 10 days therapy, as well. On the other hand, only the 10 days antibiotic therapy has prooven to be effective in the prevention of rheumatic fever and glomerulonephritic diseases. The incidence of rheumatic heart disease is currently 0.5 per 100.000 children in school age. The main morbidity after tonsillectomy is pain and the late hemorrhage. Posttonsillectomy bleeding can occur till the whole wound is completely healed, which is normally after 3 weeks. Life-threatening hemorrhages occur often after smaller bleedings, which can spontaneously cease. That is why every hemorrhage, even the smallest, has to be treated properly and in ward. Patients and parents have to be informed about the correct behavior in case of hemorrhage with a written consent before the surgery. The handout should contain important adresses, phone numbers and contact persons. Almost all cases of fatal outcome after tonsillectomy were due to false management of hemorrhage. Especially in small children hemorrhage can be life-threatening because of the lower blood volume and the danger of aspiration with asphyxia. A massive hemorrhage is an extreme challenge for every pa