Molecular diagnosis of Zoonotic Mycobacterium bovis infection in Melghat, India

Abstract

Mycobacterium bovis (M. bovis) infection in humans is not adequately diagnosed since classical biochemical and cultural tests are both sophisticated and time consuming. However, being intrinsically resistant to Pyrazinamide, the species-specific identification of M. bovis is clinically significant. The present study was performed to determine the prevalence of Zoonotic M. bovis-induced tuberculosis (TB) in the malnourished tribal population of Melghat using a duplex PCR assay targeting the regions of difference (RD) 1 and 4. A prospective cohort study was carried over a period of 2 years from 2011 to 2013 in the Melghat region of Maharashtra, India. A total number of 347 blood samples were collected from participants recruited through camps organized in 10 different villages of Melghat. The samples were then subjected to duplex PCR assay for differential identification of the mycobacterial pathogens viz., M. tuberculosis (M. tb), M. bovis and M. bovis BCG. The duplex PCR assay identified M. bovis in 2.59% (9/347) and M. tb in 17.29% (60/347) of samples. Altogether the 9 M. bovis positive cases had exposure to domesticated animals or consumed raw, unpasteurized milk. This study provided a rapid and cost effective molecular tool for screening of M. bovis in the isolated regions of Melghat.