Reverse line probe assay for the rapid detection of rifampicin resistance in Mycobacterium leprae

Mutations in the rpoB gene of 40 biopsy isolates of Mycobacterium leprae were analyzed by reverse hybridization-based line probe assay after PCR, and nine distinct single-nucleotide substitutions were found. Among them, a 3-nucleotide substitution was found in two, and 2-nucleotide substitutions were found in seven isolates. This is a new finding of multiple mutations in a single point of the rpoB gene for rifampicin resistance. This investigation demonstrates that the pattern of mutations in the rpoB gene for rifampicin resistance in Nepal involves more variety.