ABSTRACT
Background: Silent presence of non-tuberculous mycobacterium (NTM) has been observed since the last 100 years, but now the increasing incidence of NTM is of great concern for clinical microbiologists as well as clinicians. Although many advanced efforts are being made for identification and control of Mycobacterium tuberculosis, still the silently growing menace of non-tuberculous mycobacteria is receiving negligible attention. Objectives: This study was aimed to find NTMs in positive cultures and identify them up to species level. Material & Methods: During the study period, i.e. from January 2009 to June 2011, a total of 4104 positive cultures were subjected to species identification by different morphological and biochemical tests. All the tests for identification were performed as per standard procedure along with the standard strains of NTM provided by JALMA, Agra. Results: The identification of positive cultures showed 4044/15581 (25.95%) Mycobacterium tuberculosis complex and 60/15581(0.38%) NTM. The mycobacterium species identification results showed that out of total 60 NTM, 21 different species of NTM were found and they belonged to all the four groups of runyon. The most common species identified in this study was M.simiae (07) followed by M.avium(06), M.gordonae(05), M.kansasii(05), M.fortuitum(05), M.chelonae(05), M.pheli(05), M.terrae(04), M.szulgai(02), M.vaccae(02), M.flavescens(02), M. trivale(02), M.malmoense(01), M.scrofulaceum(01), M.intracellulare(01), M.xenopi(01), M.ulcerans(01), M.tusciae(01), M.triplex(01), M.septicum(01), M.mucogenicum(01). Conclusion: The isolation of NTMs from different clinical samples indicated that they may be the causative agents for pulmonary and extra-pulmonary non-tuberculous diseases. Elaborate and focused studies are needed to differentiate NTMs amongst commensal/colonizer, pathogen and laboratory contaminants.