for the initiation of antimicrobial therapy (Kothavade RJ et al., 2012). Description Gram-positive, nonmotile and acid-fast rods (1-3 µm x 0.2-0.4 µm). Sometimes long rods with occasional beaded or swollen cells having non-acid-fast ovoid bodies at one end. Colony characteristics Smooth hemispheric colonies, usually off-white or cream colored. May be butyrous, waxy, multilobate and even rosette clustered (dilute inocula). On Malachite green containing media, such as Löwenstein-Jensen media, colonies can absorb the green dye. Physiology Rapid growth on Löwenstein-Jensen media within 2–4 days. No growth at 45 °C, but grows on MacConkey agar. Differential characteristics Differentiation from M. fortuitum subsp. acetamidolyticum by its ability to use L-glutamate and its inability to use acetamide as simultaneous nitrogen and carbon source. Both subspecies share an identical 5'-16S rDNA sequence. However, the ITS sequences are different. Pathogenesis Different types of sporadic infections: pulmonary disease, local abscesses. Postoperative sternal wound infections, endocarditis, meningitis, and osteomyelitis. Has produced postoperative infections after breast augmentation surgery. Biosafety level 2 Treatment The 2007 guideline “Official American Thoracic Society (ATS) and Infectious Diseases Society of America (IDSA) statement: diagnosis, treatment, and prevention of non-tuberculosis mycobacterial diseases”, notes that M. fortuitum isolates are usually susceptible to multiple oral antimicrobial agents, including the macrolides, quinolones, some tetracyclines, and sulfonamides, as well as the intravenous carbapenems (e.g. imipenem). Ondansetron HCL (Zofran) is an antiemetic often given to offset the nausea and vomiting that are a common side effect of Imipenem. Severe infections require IV treatment combined with oral antibiotics for a prolonged period, up to several months. The guideline recommends “for serious skin, bone, and soft tissue M fortuitum disease, a minimum of 4 months of therapy with at least two agents with in vitro activity against the clinical isolate is necessary to provide a high likelihood of cure. Surgery is generally indicated with extensive disease, abscess formation, or where drug therapy is difficult.” Type strain Found world-wide in soil, dust, rivers, lakes and tap water. First isolated from a 25-year-old patient (syringe abscess) in Rio de Janeiro. Also isolated from lymph glands of cattle and systemic or nodular infection of frogs. Strain ATCC 6841 = CCUG 20994 = CIP 104534 = DSM 46621 = IFO (now NBRC) 13159 = JCM 6387 = NCTC 10394. Subsequently, this species has been divided into subspecies M. fortuitum subsp. acetamidolyticum References Further reading National Institutes of Health, Office of Rare Disease Research, Genetic and Rare