Rapid genotypic detection of rifampin- and isoniazid-resistant Mycobacterium tuberculosis directly in clinical specimens

A multiplex PCR DNA strip assay (Genotype MTBDR) designed to detect rifampin (rpoB) and high-level isoniazid (katG) resistance mutations in Mycobacterium tuberculosis isolates was optimized for clinical specimens. Successful genotypic results were achieved with 36 of 38 (95%) smear-positive respiratory. specimens. allowing rapid therapeutic adjustments in transmittable drug-resistant tuberculosis.