Abstract

RELATIONSHIP BETWEEN MUTATION IN RPO B GENE AND RESISTANCE OF MYCOBACTERIUM TUBERCULOSIS TO RIFAMPICIN IN KASHMIR (J&K), INDIA

Zafar Nowshad*, Abhishek Mathur and K. Ravi Kumar

ABSTRACT

Rifampicin is a first line anti Tuberculosis drug active against bacilli in logarithmic and stationary phase, which interferes with RNA synthesis by binding to bacterial RNA polymerase. Tuberculosis bacilli achieve resistance to rifampicin by accumulation of mutations in a short-81bp region of the rpoB gene. Among many mutations identified in the rpo B gene, few were verified by molecular genetic methods as responsible for resistance to rifampicin. In this study, 8-different mutations were identified in an 81-bp section of a “hot spot” region of rpoB gene of rifampicin resistant strain of Mycobacterium tuberculosis. The clinical strains were evaluated in respect to drug resistance. It was found that the mutations in positions 526 (H/D) 516 (D/V) and 531(S/L) codons result in high level resistance to rifampicin. Mutations in position 516(D/Y) 515(M/I) 510 (Q/H) or a double mutation in codons 512(S/I) and 516 (D/G) relates to low level of resistance.

Keywords: Tuberculosis, rifampicin resistant M. tuberculosis, drug resistance, mutations, codons.