Allele Specific-PCR method for rapid detection of gyrA gene mutaions in clinical isolates of Mycobacterium tuberculosis

Resistance to Fluroquinolones drugs are increasingly expanded. A molecular method was designed and compared for rapid detection of resistance to ofloxacin in clinical isolates of Mycobacterium tuberculosis. Materials and method s: From 136 M. tuberculosis clinical isolates, 41 strains were used for comparison of detection of mutations associated with resistance in gyrA gene by Allele Specific-PCR (AS PCR). Specific i nternal primers were designed for detecting any changes in 90, 91 and 94 codons. Sequencing method was accomplished for evaluation of the results as gold standard. AS-PCR method could detect mutations by formation or not formation of internal bounds and had good performance. Totally, from 37 strains phenotypically resistant to ofloxacine 32 strains were mutant and 5 strains were non mutant that have Sensitivity and specificity, 86/11% and 100%, respectively. Sequence results were concordant by results molecular methods. Discussion and Results of the study showed that AS-PCR method could be used as a routine test for fast detection of resistance to fluroquinolones in M. tuberculosis.