A putative short-chain dehydrogenase Rv0148 of <i>Mycobacterium tuberculosis</i> affects bacterial survival and virulence

During infection, Mycobacterium tuberculosis combats the stress generated by the host cells through the action of short-chain dehydrogenases/reductases (SDRs). Rv0148 belongs to the oxidoreductase family with the SDRs domain, which regulates the homeostasis of M. tuberculosis. In our earlier studyusing knockout mutant strain (∆0148), we reported that Rv0148 is involved in intermediary metabolism, drug resistance and cell homeostasis of M. tuberculosis . In the current study, we explored the functional role of Rv0148 using gene knockout mutant in-vitro and in-vivo models of infection. We report the ∆0148 is attenuated for virulence of M. tuberculosis. During human monocyte (THP-1) cell line infection, M. tuberculosis Δ0148 displayed reduced intracellular survival compared to the wild type at successive time points. Similarly, in a guinea pig animal model of aerosol infection, Δ0148 displayed a growth attenuation at 5- and 10-week post-infection in the lungs and spleen compared to the wild-type M. tuberculosis and Rv0148-complemented Δ0148 strains. Our study suggest that Rv0148 has a distinct role in the intracellular virulence of M. tuberculosis.