Rapid Identification of Mycobacterium tuberculosis and Non Tuberculous Mycobacterium Isolates from Pulmonary and Extra Pulmonary Samples using MGIT320 Liquid Culture System and MPT64 Antigen Test

Tuberculosis (TB) is a major public health problem in India and a leading cause of death in adults, especially among the economically productive age group. Historically TB has been associated with significant morbidity and mortality and remains a major global health problem. The present study was initiated to determine the prevalence of Mycobacterium tuberculosis, Non Tuberculous Mycobacterium and its resistance to first line Anti-Tubercular drug from both pulmonary and extra pulmonary samples A total of 583 properly collected samples (226 pulmonary and 357 extra pulmonary) from patients with clinical/radiological suspicion of Tubercular infection were included in this study. All the samples were screened by Zeihl-Neelsen AFB microscopy, and subjected to liquid culture using Mycobacterium Growth Indicator Tube (MGIT-320). Positive cultures were differentiated into Mycobacterium tuberculosis complex (MTBc) or non-tubercular mycobacterium (NTM) by immunochromatography assay using MPT-64 antigen. Further it was followed by drug susceptibility testing of MTBc isolates thereby identifying multi-drug resistant strains. Out of 583 samples, 141 strains were isolated on MGIT-320 (81 pulmonary, 60 Extrapulmonary) and the detection time was 15 days. Mycobacterium complex isolates were 116 and Nontuberculous Mycobacteria were 25. Among Mycobacterium tuberculosis complex isolates 92(56 pulmonary, 36 Extrapulmonary) were sensitive to all the drugs and 24(16 pulmonary, 8 Extrapulmonary) were resistant to one or more drugs. Multiple drug resistant (MDR) isolates were 7(6 pulmonary, 1 Extrapulmonary). MDR-TB is gradually increasing due to improper diagnosis and inadequate treatment. Differentiating mycobacterium as MTBc and NTM supported by sensitivity testing by using liquid culture has proved to be helpful in early decision for chemotherapy in MDR-TB patients.