Analysis on genetic diversity of multi-drug-resistant tuberculosis in Wuhan with MIRU-VNTR method

Objective To determine the genotype and cluster characteristics of multi-drug-resistant (MDR) mycobacterium tuberculosis in Wuhan City. Mehtods 98 mycobacterium tuberculosis isolates from MDR tuberculosis (MDR-TB) patients were genotyped by mycobacterial interspersed repetitive unit-variable number tandem repeat typing (MIRU-VNTR). Allelic diversity, Hunter-Gaston discriminatory index (HGDI), cumulative clustering rate and minimum infection rate estimation were calculated. Results The cumulative allelic diversity was 0.960 4. The discriminatory power was 0.970 8. Gene locus with the highest h and HGDI were Mtub21 and MIRU26 respectively. Seven clusters and 65 unique genotype were identified from 98 isolates, and the cluster rate was 33.67% and the least estimated proportion of recent transmission was 26.53%. Conclusions The 15 locus MIRU-VNTR method demonstrate relatively high discriminatory power and it is suitable for MDR mycobacterium tuberculosis isolates genotyping. Although the epidemic of MDR-TB in Wuhan is mainly due to reactivation, there is still a partial contribution from recent transmission.