Newly developed primers for comprehensive amplification of the rpoB gene and detection of rifampin resistance in Mycobacterium tuberculosis.

New rpoB gene primers for detecting Rif(r) in Mycobacterium tuberculosis complex bacteria achieved 100% specificity and 88% (fresh sputa) and 92% (ethanol-preserved sputa) diagnostic sensitivity and detected up to 4 CFU/sample. Of the 99 Rif(r) isolates examined, 97% had mutations within cluster I, 2% at codon 176, and 1% at codon 497.