Multiple-locus variable number tandem repeat analysis on genotypes of 80 strains of Mycobacterium tuberculosis in Changle, Fujian province

Objective To understand the genotype distribution of the clinical isolates of Mycobacterium tuberculosis, major circulating strains and related circulating patterns in Changle, Fujian province. Methods Fifteen locus of variable number tandem repeats(VNTR)were used to detect 80 clinical strains of M. tuberculosis isolated in Changle, and clustering analysis of the strains were performed by using BioNumerics 5.0. Results The 80 M. tuberculosis strains were classified into 7 gene groups, i.e. Ⅰ, Ⅱ, Ⅲ, Ⅳ,Ⅴ, Ⅶ and Ⅷ. GroupⅠwas the major group which had 59 strains(73.8%). The gene groups of M. tuberculosis wereⅠ, Ⅱ, Ⅳ, Ⅶ and Ⅷ were detected in floating population andⅠ, Ⅱ, Ⅲ, Ⅳ,Ⅴand Ⅷ were detected in local population. The VNTR analysis indicated that some differences existed in the genotypes of M. tuberculosis detected between floating population and local population, but gene group I was predominant in two populations. No significant difference was detected in drug resistance between the isolates in groupⅠand other groups(P0.05). Conclusion Seven gene groups of M. tuberculosis were detected and obvious gene polymorphism was observed in Changle. GroupⅠwas the predominant genotype in both floating population and local population. It is necessary to strengthen the surveillance for the circulating of the strains in this gene group.