# Molecular identification of Mycobacterium bovis in patients with tuberculosis attending a tertiary care hospital in South India

## TL;DR

The study found that Mycobacterium bovis is rare among tuberculosis cases in a South Indian hospital, suggesting it poses little public health risk there.

## Contribution

The paper provides empirical evidence on the low prevalence of M. bovis in TB patients in South India using molecular diagnostics.

## Key findings

- All pulmonary TB samples were identified as M. tuberculosis or M. canettii.
- Only 1% of extrapulmonary TB samples were M. bovis BCG.
- M. bovis appears to be uncommon in the studied Indian population.

## Abstract

Mycobacterium (M.) bovis is a member of Mycobacterium tuberculosis complex (MTBC). Clinical infection caused by M. bovis is indistinguishable from other MTBC and could pose a potential challenge for control of TB epidemic due to its zoonotic nature. Availability of reliable molecular diagnostic methods such as Genotype MTBC based on line probe assay (LPA) paves way for reliable differentiation of M. bovis from other MTBC.

To determine the proportion of Mycobacterium bovis among the Mycobacterium tuberculosis complex isolates from patients with tuberculosis.

In our study, we analysed MGIT positive cultures and performed Line probe assay (LPA) for identification of MTBC isolates. Total of 206 patient samples were taken, 104 pulmonary and 102 from extrapulmonary sites.

M.tuberculosis/M.canettii was isolated in all pulmonary specimens (100%). Among 102 extrapulmonary samples, 99 % was identified as M.tuberculosis/M.canettii, and 1 % as M. bovis BCG.

Our study suggests that zoonotic TB by M. bovis may not be as prevalent in India and hence may not constitute a significant risk to public health in India.