The Research Of Identification Of Mycobacterium Tuberculosis Isolates By DNA Typing Technique

Objective To assess the application of 186110-restriction fragment length polymorphism (RFLP), Spoligotyping and mycobacterial interspersed repetitive unit(MIRU) in the epidemiology of tuberculosis, and to discuss the characteristic of the Mycobacterium tuberculosis strains in different regions in China. Methods Mycobacterium tuberculosis strains, totally 158 isolates, isolated from Beijing, HeiLongJiang, Guangdong tinner Mongolia and Tibet, were subjected to IS6110-RFLP ,Spoligotyping and MIRU.Result The discriminatory power of IS6110-RFLP is higher than that of Spoligotyping. But when the copies of IS6110 are lower than 10, the discriminatory power of Spoligotyping improved obviously. There was significantly difference among the mycobacterium tuberculosis in the different regions in clustered rate and the proportion of Beijing genotype (p<0. 05). The result of Spoligotyping was compared with international Spoligotype database. Fourteen types belonged to the shared types, in which the type 1 is epidemic and widely. The discriminatory power of MIRU typing was close to that of IS6110-RFLP for typing of M. tuberculosis. In MIRU loci, there were four loci(loci 4, 10, 26, 40) with higher diversity. Conclusion The results of this study indicated that either IS6110-RFLP , Spoligotyping or MIRU technique is very useful for the epidemiological investigation of tuberculosis in China. The strains in different regions have different character in China. Especially MIRU typing that is easy to popularize will exert important function in the epidemiological investigation of tuberculosis.