Mutation of rpoB gene in M leprae isolates from Korea

Kim, Jong Pill; Kim, Yeon sil

Abstract

Global efforts to control leprosy by intensive chemotherapy, including rifampin, have led to a significant decrease in the number of registered patients. But emergence of rifampin-resistant strains of pathogenic mycobacteria has threatened the usefulness of this drug in treating mycobacterial diseases. Mutations in the rpoB gene, encoding the betasubunit of RNA polymerase, were reported to result in resistance to rifampin in several mycobacterial species, including M leprae. To prevent the emergence and transmission of drug-resistant leprosy and to identify and treat existing cases, it is necessary to establish rapid methods for detection of drug resistance in M leprae. However, M. leprae has not been cultivated on artificial media; therefore, to identify drug susceptibility patterns, bacteria must be tested using Shepard's mouse footpad assay. This in vivo method requires at least 6 months and relatively large numbers of bacteria. Recently, there have been advances in the elucidation of molecular events responsible for drug resistance in mycobacteria Sequences of the rpoB, genes were analyzed for 43 isolates of Mycobacterium leprae from leprosy patients in Korea. Three isolates(6.98%) showed representative mutations in the rpoB, genes, suggesting the emergence of rifampin-resistant M. leprae.