Evaluation of BacT/Alert 3D Automated Unit for Detection of Nontuberculous Mycobacteria Requiring Incubation at 30°C for Optimal Growth

The reliability of the BacT/Alert 3D unit for automated detection of nontuberculous mycobacteria (NTM) that grow optimally at 30°C was assessed. This system reliably maintained a temperature of 30°C and detected 50 % of the clinical NTM strains (5 Mycobacterium marinum and 3 Mycobacterium gordonae strains) faster than 37°C culture. A wide range of mycobacterial species exist that cause a spectrum of infections, including pulmonary disease and skin, soft tissue, bone, and joint infections (7). Although the majority of mycobacteria grow well at 37°C, there are some species, such as M. marinum, M. chelonae, M. ulcerans, and M. haemophilum, that grow optimally at 30°C (2). This sub-set of mycobacteria is being recovered more frequently from both immunocompromised and immunocompetent patients (2, 6, 7) and is often associated with skin, soft tissue, bone, and joint infections (5). As such, most laboratory protocols for mycobacterial culture recommend that these specimen