High genetic diversity among Mycobacterium tuberculosis strains in Tehran, Iran. (May 2018)

• Record Type: Journal Article
• Authors: Azimi, Taher; Nasiri, Mohammad Javad; Zamani, Samin; Hashemi, Ali; Goudarzi, Hossein; Fooladi, Abbas Ali Imani; Feizabadi, Mohammad Mehdi; Fallah, Fatemeh
• Is Part Of: Journal of clinical tuberculosis and other mycobacterial diseases. Volume 11(2018)
• Page Start: 1
• Page End: 6
• Publication Date: 2018-05
• Subjects: Mycobacterium tuberculosis -- Genotyping -- MIRU-VNTR -- Tehran -- Iran; Tuberculosis -- Periodicals; Mycobacterial diseases -- Periodicals; 616.995
• DOI: 10.1016/j.jctube.2018.01.001
• Languages: English
• ISSNs: 2405-5794

Abstract

Abstract: Introduction: Tuberculosis (TB) still remains an important public health problem in Iran. The genotyping of Mycobacterium tuberculosis isolates is expected to lead to a better understanding of M. tuberculosis transmission in Tehran, the most populated city of Iran. Materials and Methods: A total of 2300 clinical specimens were obtained from TB suspected patients who were referred to a TB center in Tehran from Jan 2014 to Dec 2016. Identification was performed using both conventional and molecular methods. The presence of resistance to rifampicin was examined by the GeneXpert MTB/RIF. The standard 15-locus mycobacterial interspersed repetitive units-variable number of tandem repeats (MIRU-VNTR) typing method was applied to genotype of clinical isolates. Results: Of 2300 specimens, 80 isolates were identified as M. tuberculosis by using biochemical and molecular tests. Of 80 M. tuberculosis isolates, 76 (95%) had unique genotypic profiles and 4 (5%) shared a profile with one or more other strains. Based on single loci variation (SLV) 4 clonal complexes were observed. NEW-1 was found to be the most predominant lineage (22.5%) followed by West African (1.25%), Central Asian (CAS)/Delhi (1.25%), Bovis (1.25%), H37Rv (1.25%) and multiple matches (1.25%). Loci MIRU10, MIRU26, MTUB21 and QUB26 were found as highly discriminative. No mutation was detected in the hotspot region of rifampicin by using GeneXpert MTB/RIF. Conclusions: Our study findings show that there was considerable genotypic diversity among M. tuberculosis isolates in Tehran. The 15-locus MIRU-VNTR showed high HGDI and could be used as a first-line genotyping method for epidemiological studies.