Genetic diversity of Mycobacterium tuberculosis isolates obtained from three distinct population groups in the Central Province, Sri Lanka

Objective: To characterize the Mycobacterium tuberculosis (M. tuberculosis) isolates by\udspoligotyping and mycobacterial interspersed repetitive unit-variable number tandem repeat\ud(MIRU-VNTR) typing to understand how M. tuberculosis strains transmit among the study\udpopulation.\udMethods: Spoligotyping and MIRU-VNTR were used to genotype M. tuberculosis isolates\udobtained from three distinct population groups in Sri Lanka. General population suspected of\udhaving tuberculosis attending the Chest Clinic, Kandy (n = 78), patients having tuberculosis in\udBogambara prison, Kandy (n = 22) and estate workers having tuberculosis in the Central Province,\udSri Lanka (n = 50), from January 2012 to April 2014 were included in the study.\udResults: Among 150 isolates, a total of 19 distinct families were observed including 6 major\udspoligotyping-based families; East-African-Indian (39.33%), Haarlem (20%), Beijing (8.6%),\udCentral European family T (6.5%), European family X (5.2%) and Central and Middle Eastern\udAsian (0.6%). Beijing strains were only identified among the general population. MANU strains\udwere significant (36.36%) among the prisoners who had clustered with the MANU strains of\udthe general population indicating contact cases and a possible transmission index within a\udparticular geographical area. Haarlem 3 (34%) was the predominant strain among the estate\udworkers. There was a close epidemiological relationship between the prisoners and the estate\udworkers in the population.\udConclusions: The first insight of 15 loci MIRU-VNTR typing in conjunction with spoligotyping\udin a population in Sri Lanka demonstrated the feasibility and the applicability of these\udtechniques to differentiate strains, their heterogeneity and the predominance of several\udworldwide distributed spoligotypes