VNTR位点对结核分枝杆菌基因分型的研究

A study on genotyping of mycobacterium tuberculosis by variable number tandem repeat analysis method

目的初步评价15个可变串联重复序列(VNTR)位点对结核分枝杆菌临床分离株的分型能力,寻找适合湖州地区结核分枝杆菌基因分型的位点。方法 2011年1—4月连续收集湖州地区结核分枝杆菌临床分离株,采用多位点数目多位点串联系复序列(MLVA)分析方法,对15个VNTR位点进行基因多态性检测,分析单个位点以及15个位点组合的基因分型能力(Hunter-gaston指数,HGDI)。结果分辨率较好的多态性位点有2个:Mtub-21和Mtub-39;分辨率中等的多态性位点共7个:ETR-A,ETR-C,MIRU-10,MIRU-23,MIRU-27,MIRU-40和Mtub-30;分辨率较差的多态性位点有6个:ETR-B,ETR-D,ETR-E,MIRU-16和MIRU-26和MIRU-39。通过计算,本次研究运用15个位点进行基因分型的HGDI为0.99,分辨能力好。结论 VNTR位点对结核分枝杆菌基因的分辨力较好,但还需继续寻找其他丰富多态性的VNTR位点,以便快速分型,提高分辨力。

Objective To preliminarily evaluate the ability of 15 -loci variable number tandem repeats on the genotyping of clinical isolates of mycobacterium tuberculosis,and explore the suitable loci for genotyping of Mycobacterium tuberculosis in Huzhou City.Methods From 201 1 January to 201 1 April,the clinical isolates of mycobacterium tuberculosis were selected from Huzhou area to test the polymorphism of every loci by using MLVA detection method and analyze hunter-gaston discriminatory index of individual locus as well as combinations of 15 locus.Results There were two locus of Mtub-21 and Mtub-39 which had better degree of polymorphism;seven locus of ETR-A,ETR-C,MIRU-10,MIRU-23,MIRU-27,MIRU-40 and Mtub-30 had moderate degree of polymorphism;six locus of ETR-B,ETR-D,ETR-E,MIRU-16,MIRU-26 and MIRU-39 had poor degree of polymorphism.By calculation,the result showed that HGDI was 0.99 by using 15 locus to genotype,which indicated the ability to distinguish the genotype was good.Conclusion We will continue to look for other rich VNTR polymorphism locus to fit the local region fast genotyping of mycobacterium tuberculosis for higher resolution and cost effectiveness of mycobacterium tuberculosis control and prevention.