Molecular detection of mutations in isolates of multidrug resistant tuberculosis and tuberculosis suspects by multiplex allele specific PCR

For lowering prevalence of drug resistance it is necessary to diagnose TB in tuberculosis sputum suspect patients instead of TB-cultured samples which required a long time of culturing. Comparison of the results of drug resistant bacterial genes in both tuberculosis suspect sputum and multi-drug resistant DNA isolates detected by MAS-PCR. In the current study, the genetic mutations linked with INH, RIF as well as EMB drugs were detected by MAS-PCR simultaneously in MDR as well as TB suspect sputum isolates. 175/291 samples belonged to MDR and 116/291 samples belonged to tuberculosis suspect group. In all the isolates, presence of Mycobacterium tuberculosis-species (100%) was confirmed by targeting hupB gene. In MDR group, maximum prevalence of gene mutation was detected in rpoB531 (92.57%) and embB306 (97.71%) while in TB-suspect group, equal percentage (96.55%) of mutation was detected in rpoB531 and embB306 by MAS-PCR. Collectively, rpoB531 (n=274, 94.15%) and embB306 (n=283, 97.25%) mutation were observed in maximum tuberculosis cases. MAS-PCR technique yielded reliable results and showed massive Isoniazid, Rifampicin and Ethambutol drugs resistance in TB-isolates from Pakistan; hence it can be used in clinical laboratories with high burden of tuberculosis to detect drug resistance rapidly and cost effectively.