A new Multi-PCR-SSCP assay for simultaneous detection of isoniazid and rifampin resistance in Mycobacterium tuberculosis

Prompt detection of drug resistance in Mycobacterium tuberculosis is essential for effective control of tuberculosis (TB). We developed a Multi-PCR-SSCP method that detects more than 80% commonly observed isoniazid (INH) and rifampin (RIF) resistance M. tuberculosis in a single assay. The usefulness of the newly developed method was evaluated with 116 clinical isolates of M. tuberculosis. Distinct SSCP patterns were observed for different mutations and the correlation between Multi-PCR-SSCP results and DNA sequencing data was strong. Using the culture-based phenotypic drug susceptibility testing as a reference, the sensitivity of the newly developed Multi-PCR-SSCP assay was determined to be 80% and 81.8% for INH and RIF, respectively. The specificity of the assay was 100% and 92%, for INH and RIF, respectively. Multi-PCR-SSCP provides a rapid and potentially more cost-effective method of detecting multidrug-resistant TB.