Rapid detection of MDR-Mycobacterium tuberculosis using modified PCR-SSCP from clinical Specimens

ABSTRACT

Objective: To design a rapid test to detect the rifampin (RIF) and isoniazid (INH) resistant mutant based on polymerase chain reaction-single strand conformation polymorphism (PCR-SSCP) technique that analyzes the katG, rpoB genes.Methods:tuberculosis. To determine the susceptibility of isolates to anti TB drugs, the proportional method was used. Mutations presented within the amplified products of the katG, rpoB genes were evaluated by SSCP.Results:Using proportional method, 12 (11.6%) and 9 (8.7%) isolates were resistant respectively Biochemical test as well as IS6110 targeting PCR revealed 103 clinical samples were to INH and RIF and 9 (8.7%) isolates showed resistance to both drug (multi-drug resistant tuberculosis). Three (2.9%) multi-drug resistant tuberculosis and two INH resistant isolates were detected by the PCR-SSCP and sequencing. The sensitivity and specificity of PCR-SSCP for multi-drug resistant isolates were 33% and 100%, respectively.Conclusions:Complete agreement between SSCP and sequencing can indicate that resistance-associated mutations have occurred in other genes except our considered genes.