Introduction: Due to the emergence of multidrug/extensively drug-resistant TB and the lack of new anti-TB drugs, tracing the infectious source and monitoring the transmission of drug-resistant TB strains have become critically important.
Methods: To determine which VNTR locus set is more suitable for use in Zunyi, China, we used 19 VNTR loci including 4 recommended by the China CDC, 4 recommended a group of scientists from Europe and USA, and 11 recommended by both for molecular typing of 100 clinical M. tuberculosis isolates from Zunyi, Guizhou Province of China. PCR amplified DNA fragments were analyzed by comparing their sizes on the gel images with those amplified from the reference M. tuberculosis H37Rv strain at each of the 19 corresponding VNTR loci to determine copy numbers of each VNTR. The cluster analysis was carried out by using the Bionumerica 5.0 software.
Results: High polymorphism in loci MIRU26, Mtub4, Mtub21, QUB11B, and QUB26, and low polymorphism in loci ETRC and MIRU23 were detected in 100 M. tuberculosis strains isolated from Zunyi, Guizhou Province of China. The Hunter-Gaston index values for 15-VNTRChina and 15-VNTRInternation are 0.9992 and 1 respectively.
Conclusion: Results from this study indicate that the 15-VNTRInternation has the higher discrimination power than the 15-VNTRChina for molecular genotyping of clinical M. tuberculosis isolates from Zunyi, and is an appropriate tool for molecular epidemiological studies of M. tuberculosis in Zunyi, Guizhou Province of China.
Published on: Jun 26, 2015 Pages: 1-6