Prevalence of Mycobacterium tuberculosis Strains Isolated from Both Pulmonary and Extra Pulmonary Samples and Their Resistance to Rifampicin: A Study from Kolkata and Surrounding Suburbs

Tuberculosis (TB) is one of the major causes of morbidity and mortality worldwide. In India, nearly 1.8 million new cases of TB are reported annually, which accounts for a fifth of new cases in the world—greater than in any other country. Anti-tubercular drugs (ATDs) have been used for decades, and widespread resistance to them is a very serious public health concern in any part of the world. Aim of this study was to determine the prevalence of Rifampicin (the first line Anti-TB drug) resistance among both pulmonary and extra-pulmonary samples tested positive for Mycobacterium tuberculosis and thereby predict the prevalence of Multi-drug resistant (MDR) tuberculosis in Kolkata and its Suburban regions. All 331 randomly collected clinical samples (both Pulmonary and Extra Pulmonary) were initially screened by Zeihl-Neelsen AFB staining followed by culture on BacT/Alert 3D system and on Lowenstein-Jensen medium and the positive samples were subjected to detection of Mycobacterium tuberculosis complex (MTBC) and simultaneous analysis of Rifampicin resistance by Xpert MTB/RIF assay. Out of the 51 (15.40%) culture positive samples, 13.7% of pulmonary samples and 9.09% of extra-pulmonary samples were Rifampicin resistant. The prevalence of Rifampicin resistant TB in our study is high and the possible reasons can be mixing of new as well as retreatment cases and smaller sample size but, yet it can help Government and public health regulatory bodies to formulate adequate strategies to fight against drug resistant tuberculosis, especially in this part of the world.