OBJECTIVE

To assess the application of IS6110-restriction fragment length polymorphism (RFLP), Spoligotyping and mycobacterial interspersed repetitive unit (MIRU) in epidemiological studies of tuberculosis and to discuss the characteristics of Mycobacterium tuberculosis strains in different regions in China.

METHODS

Mycobacterium tuberculosis strains, with a total number of 158 isolates, were subjected to IS6110-RFLP, Spoligotyping and MIRU.

RESULTS

The numbers of patterns produced by IS6110-RFLP, Spoligotyping, and MIRU typing were 118, 20 and 105 respectively. The discriminatory power of IS6110-RFLP was higher than that of Spoligotyping. However, when the copies of IS6110 were lower than 10, the discriminatory power of Spoligotyping improved obviously. The discriminatory power of MIRU typing was close to that of IS6110-RFLP for typing of Mycobacterium tuberculosis. In MIRU loci, there were four loci (loci 4, 10, 26, 40) with higher diversity. Significant differences among the Mycobacterium tuberculosis between Guangdong and other regions in clustered rate and the proportion of Beijing genotype (P < 0.05) were found. The clustered rates and the proportion of Beijing genotype in Guangdong were lower than that in other regions.

CONCLUSION

The results of this study indicated that either IS6110-RFLP, Spoligotyping or MIRU technique was useful for epidemiological studies on tuberculosis in China and the strains in different regions had different characterishes in China.