Molecular typing of Mycobacterium tuberculosis isolated from patients in Srinagarind Hospital: Analysis by mycobacterial interspersed repetitive unit-variable number tandem repeat

Abstract

Tuberculosis is one of the important infectious diseases which has been distributed around the world. The incidence of tuberculosis still presents in the Asia and Africa. Thailand is ranking in 18 of 22 high burden countries in 2014 reported by WHO. The epidemiological study of Mycobacterium tuberculosis based on molecular methods have been developed and widely used to investigate the genetic diversity, control the disease transmission and evaluate drug resistance.  In this study, 27 M. tuberculosis isolates from Srinagarind hospital, Khon Kaen in 2001, were analyzed using 24 loci primers based on mycobacterial interspersed repetitive unit-variable number tandem repeat (MIRU-VNTR) typing. Genotyping revealed a total of 24 MIRU-VNTR profiles comprising of 2 lineages: 14 East-African Indian (EAI) isolates (51.85%) with 11 profiles and 3 Beijing isolates (11.11%) with 3 profiles. The other 10 unique profiles (37.04%) were not identical to any profile in MIRU-VNTRplus database. In addition, the discriminatory index for each loci was calculated using Hunter Gaston Discriminatory Index (HGDI). Mtub04 (0.6), MIRU04 (0.855), MIRU16 (0.613), Q2163b (0.693), ETRA (0.673), ETRB (0.777), Mtub39 (0.780) and QUB26 (0.704) showed high HGDI. These 8 MIRU primers may be appropriate for epidemiology investigation in this region.