Aim and Background:Non-tuberculous mycobacteria have long been identified as capable of causing human disease. Several reports have suggested increasing trend to available treatment regimes. The aim of this study was to evaluate antibiotic susceptibility of clinically significant NTM using standard micro broth dilution test.

Material and methods:The antimicrobial susceptibility testing was performed following National Committee for Clinical Laboratory Standards (NCCLS) method for 88 clinical isolates of slowly growing mycobacteria (SGM) and 154 clinical isolates of rapidly growing mycobacteria (RGM).

Results:Among the 40 isolates of M. kansasii, all were susceptible to Ethambutol, Isoniazid, Clarithromycin, Moxifloxacin and Linezolid. The isolates also were resistant to Doxycycline and 50% isolates were resistant to Rifampicin and Ciprofloxacin.

Conclusion:The presence of high variations in susceptibility among clinically important NTM to the currently available antimicrobial agents confirms the need for accurate identification as well as performing standard susceptibility testing of any clinically important isolate.