Expression analysis of efflux gene Rv1634 in drug resistance Mycobacterium tuberculosis isolates

Drug resistant tuberculosis (DR-TB) is a serious health issue worldwide and a number of mechanisms have been suggested which are involved in developing resistance in Mycobacterium tuberculosis to anti-tuberculosis drugs. In the Indian perspective, the pattern and prevalence of drug-resistant tuberculosis (DR-TB) are heterogeneous across regions and settings. Notably, isoniazid (INH), rifampicin (RIF) and ethambutol (EMB) are the most effective drugs in tuberculosis therapy. Understanding the pattern of resistance to these drugs in the Indian population is essential in quick diagnosis of multidrug-resistant (MDR) tuberculosis and extensive DR-TB (XDR-TB). A total of 36 Mycobacterium isolates from the North Indian population were exposed and tested for drug susceptibility with INH, RIF and EMB in vitro and results showed that 25, 24 and 24 isolates were resistant to INH, RIF and EMB respectively. Gene expression analysis revealed that approximately 50% of isolates under the stress of these three anti-tuberculosis drugs showed overexpression of efflux gene Rv1634. Moreover, overexpression of gene Rv1634 contributes to the emergence of drug resistance in M. tuberculosis and inhibition of Rv1634 along with other efflux pump genes and may provide a promising strategy for improving tuberculosis treatment outcomes in North India.