Title: Causative agents and antimicrobial susceptibilities of urinary tract infections in the northwest of Iran - ScienceDirect
Headings: Causative agents and antimicrobial susceptibilities of urinary tract infections in the northwest of Iran
International Journal of Infectious Diseases
Causative agents and antimicrobial susceptibilities of urinary tract infections in the northwest of Iran
Summary
Background
Methods
Results
Conclusions
Keywords
Introduction
Methods
Study design
Isolation and identification of organisms
Susceptibility testing
Statistical analysis
Results
Isolation and identification of bacteria
Antimicrobial susceptibility
Discussion
References

Content: Table 1. Frequency of isolated bacteria from positive urine samples according to patient age
Organism
Age (years)
Total n (%)

0–9 n (%)
10–19 n (%)
20–29 n (%)
30–39 n (%)
40–49 n (%)
50–59 n (%)
>60 n (%)

Escherichia coli
60 (80)
61 (78.2)
153 (78.5)
77 (72.6)
59 (70.2)
48 (75)
46 (62.2)
504 (74.6)
Klebsiella spp
2 (2.7)
9 (11.5)
19 (9.7)
12 (11.3)
15 (17.9)
7 (10.9)
15 (20.3)
79 (11.7)
Enterobacter spp
2 (2.7)
-
4 (2.1)
-
1 (1.2)
1 (1.6)
-
8 (1.2)
Proteus spp
2 (2.7)
1 (1.3)
2 (1.0)
2 (1.9)
-
1 (1.6)
-
8 (1.2)
Pseudomonas aeruginosa
5 (6.7)
1 (1.3)
1 (0.5)
-
1 (1.2)
-
7 (9.5)
15 (2.2)
Staphylococcus aureus
1 (1.3)
-
4 (2.1)
-
2 (2.4)
2 (3.1)
2 (2.7)
11 (1.6)
Staphylococcus saprophyticus
3 (4)
5 (6.4)
10 (5.1)
11 (10.4)
5 (6.0)
5 (7.8)
4 (5.4)
43 (6.4)
Enterococci
-
1 (1.3)
2 (1.0)
4 (3.8)
1 (1.2)
-
-
8 (1.2)

Total (%)
75 (11.1)
78 (11.5)
195 (28.8)
106 (15.7)
84 (12.4)
64 (9.5)
74 (10.9)
676 (100)
Antimicrobial susceptibility
The rates of resistance of isolates to a panel of antibiotics, including penicillins, cephalosporins, quinolones, aminoglycosides, and trimethoprim–sulfamethoxazole, which are routinely used to treat UTI infections, are shown in Table 2. E. coli as the predominant cause of UTI, showed the highest percentage of resistance to ampicillin (93.1%) and the lowest resistance to amikacin (2.2%). Klebsiella spp as the second most prevalent pathogen of UTI displayed a similar resistance pattern and were resistant to ampicillin in 91.1% of cases and susceptible to amikacin in 98.7% of cases. P. aeruginosa showed the highest antibiotic resistance rate and was significantly resistant to most of the antibiotics ( Table 1 ). In this study, staphylococci were responsible for about 8% of UTI cases; among these, S. saprophyticus was the most common species isolated. S. saprophyticus and Staphylococcus aureus were resistant to ampicillin in 58.1% and 72.7% of cases, respectively, whereas, 46.5% of S. saprophyticus and 36.4% of S. aureus were resistant to oxacillin. Table 2. Resistance rates of isolated bacteria from positive urine samples to commonly used antibiotics
Organism
N
Antibiotic


AMK
GEN
CIP
NIT
NAL
SXT
CEP
AMP
CAR
VAN
OXA
Escherichia coli
504
11 (2.2%)
15 (3.0%)
30 (6.0%)
65 (12.9%)
32 (6.3%)
261 (51.8%)
121 (24.0%)
469 (93.1%)
-
-
-
Klebsiella spp
79
1 (1.3)
15 (19.0%)
1 (1.3%)
36 (45.6%)
11 (13.9%)
32 (40.5%)
27 (34.2%)
72 (91.1%)
-
-
-
Enterobacter spp
8
0 (0%)
2 (25%)
0 (0%)
3 (37.5%)
0 (0%)
3 (37.5%)
3 (37.5%)
8 (100%)
-
-
-
Proteus spp
8
0 (0%)
0 (0%)
0 (0%)
5 (62.5%)
0 (0%)
3 (37.5%)
2 (25%)
8 (100%)
-
-
-
Pseudomonas aeruginosa
15
2 (13.3%)
4 (26.7%)
2 (13.3%)
15 (100%)
15 (100%)
15 (100%)
15 (100%)
15 (100%)
-
-
-
Staphylococcus aureus
11
0 (0%)
0 (0%)
0 (0%)
2 (18.2%)
-
2 (18.2%)
2 (18.2%)
8 (72.7%)
0 (0%)
0 (0%)
4 (36.4%)
Staphylococcus sa