Molecular characterization of Mycobacterium tuberculosis isolates from Tehran, Iran by restriction fragment length polymorphism analysis and spoligotyping

• Published in: Revista da Sociedade Brasileira de Medicina Tropical Vol. 49; no. 2; pp. 204 - 210
• Main Authors: Feyisa, Seifu Gizaw, Haeili, Mehri, Zahednamazi, Fatemeh, Mosavari, Nader, Taheri, Mohammad Mohammad, Hamzehloo, Gholamreza, Zamani, Samin, Feizabadi, Mohammad Mehdi
• Format: Journal Article
• Language: English
• Published: Brazil Sociedade Brasileira de Medicina Tropical 01-04-2016; Sociedade Brasileira de Medicina Tropical - SBMT; Sociedade Brasileira de Medicina Tropical (SBMT)
• Subjects: Bacterial Typing Techniques - methods; Cluster Analysis; DNA Fingerprinting; DNA, Bacterial - genetics; Genetic diversity; Genetic Variation - genetics; Genotype; Humans; Iran; IS6110-RFLP; Molecular Epidemiology; Multidrug resistant organisms; Mycobacterium tuberculosis; Mycobacterium tuberculosis - genetics; Mycobacterium tuberculosis - isolation & purification; Polymorphism; Polymorphism, Restriction Fragment Length; Spoligotyping; TROPICAL MEDICINE; Tuberculosis; Tuberculosis - microbiology; Mycobacterium tuberculosis; Spoligotyping; IS6110-RFLP
• ISSN: 0037-8682; 1678-9849; 1678-9849; 0037-8682
• DOI: 10.1590/0037-8682-0405-2015

INTRODUCTION Characterization of Mycobacterium tuberculosis (MTB) isolates by DNA fingerprinting has contributed to tuberculosis (TB) control. The aim of this study was to determine the genetic diversity of MTB isolates from Tehran province in Iran. METHODS MTB isolates from 60 Iranian and 10 Afghan TB patients were fingerprinted by standard IS6110-restriction fragment length polymorphism (RFLP) analysis and spoligotyping. RESULTS The copy number of IS6110 ranged from 10-24 per isolate. The isolates were classified into 22 clusters showing ≥ 80% similarity by RFLP analysis. Fourteen multidrug-resistant (MDR) isolates were grouped into 4 IS6110-RFLP clusters, with 10 isolates [71% (95% CI: 45-89%)] in 1 cluster, suggesting a possible epidemiological linkage. Eighteen Iranian isolates showed ≥ 80% similarity with Afghan isolates. There were no strains with identical fingerprints. Spoligotyping of 70 isolates produced 23 distinct patterns. Sixty (85.7%) isolates were grouped into 13 clusters, while the remaining 10 isolates (14.2%) were not clustered. Ural (formerly Haarlem4) (n = 22, 31.4%) was the most common family followed by Central Asian strain (CAS) (n = 18, 25.7%) and T (n = 9, 12.8%) families. Only 1strain was characterized as having the Beijing genotype. Among 60 Iranian and 10 Afghan MTB isolates, 25% (95% CI: 16-37) and 70% (95% CI: 39-89) were categorized as Ural lineage, respectively. CONCLUSIONS A higher prevalence of Ural family MTB isolates among Afghan patients than among Iranian patients suggests the possible transmission of this lineage following the immigration of Afghans to Iran.