Genotypic detection of mutations in rifampicin resistant clinical isolates ofMycobacterium tuberculosis.

The resistance of majority ofM. tuberculosis strains to rifampicin a key drug in the tuberculosis therapy, has been cause of major alarm world-wide. Such an association of strain with the drug takes a long time i.e. 2-3 months. We have modified a method for rapid detection of rifampicin resistant strains by screening them through PCR-SSCP.We have identified mutations in rpo, β region of the gene encoding, β sub-unit of RNA polymerase in rifampicin resistant 67 clinical isolates ofM. tuberculosis. Mutations were screened in these isolates by single strand confirmation polymorphism (SSCP). When DNA sequencing data was compared with the result of SSCP analysis, direct PCR sequencing results were more easily interpreted and contatined more sequence dependent information. These findings provide the basis for rapid detection of rifampicin esistance, a marker of multidrug resistance.