Genotyping of Isolates from Hormozgan Province of Iran Based on 15-Locus MIRU-VNTR and Spoligotyping.

. Considering that Hormozgan province in Iran (southern part of Iran on the Persian Gulf) is among the areas with high prevalence of MDR-MTB and attracts so many sailors and tourists, genetic diversity of MTB isolates circulating in this part of Iran was evaluated. Pattern of TB transmission was also examined. . A total of 38 isolates of MTB were cultured from TB patients from Hormozgan province of Iran and standard MIRU-VNTR typing and spoligotyping were applied to genotype these isolates. Drug susceptibility testing was performed using proportion method. . There were 28 VNTR profiles comprising 5 clusters and 23 unique isolates compared to 21 spoligotyping profiles, which contained 9 clusters and 12 unique isolates. Latin American-Mediterranean ( = 9, 23.6%) was found to be the most predominant lineage. MIRU-VNTR analysis, with an HGDI of 0.975, was more discriminating than spoligotyping, which had an HGDI of 0.955. The estimated proportion of TB cases due to recent transmission was 26.3% and 44.7% by MIRU-VNTR and spoligotyping, respectively. The rates of monodrug resistance and MDR were 15.8% and 7.9%, respectively. Two of 3 MDR strains were found to be related to MIRU-VNTR and belonged to the same spoligotyping cluster characterized with T1/SIT53 genotype. . The high genetic diversity among MTB isolates suggests that transmission occurred from different sources to this area. Reactivation of a priori, latent MTB infection was found to contribute mainly to TB cases in this geographic region.