Abstract

To investigate the genetic diversity of Mycobacterium tuberculosis (MTB) strains MIRU-VNTR as a powerful tool was used. In this study 80 isolates from patients were analyzed using primers based on IS6110 gene fragment specific for MTB complex. Then R&D typing based on regions of difference was used to differentiate MTBC members. The MTB isolates were genotyped by 12 loci based MIRU-VNTR. The discriminatory index for each loci was calculated using the Hunter Gaston Discriminatory Index (HGDI), of these, 60 cases were identified as MTB by polymerase chain reaction (PCR) method and RD-PCR typing. Forty eight distinct patterns comprising of 11 clusters and 37 unique patterns were identified. The discriminatory power of MIRU-VNTR typing was high (HGDI= 0.991) for these samples. Also we could detect a case of mixed infection by MIRU-VNTR. The results show that MIRU-VNTR typing is a useful method for studying genetic diversity of MTB in regional settings.

Key words: Mycobacterium tuberculosis, genotyping, mycobacterial interspersed repetitive unit – variable number tandem repeat, Khuzestan, tuberculosis.