大理地区结核分枝杆菌MIRU-VNTR位点的多态性分析  

Analysis of polymorphisms in Mycobacterium tuberculosis from Dali based on MIRU-VNTRs

作　　者：董毅[1] 吴利先[1] 

机构地区：[1]大理学院基础医学院微生物学与免疫学教研室,云南大理671000

出　　处：《中国病原生物学杂志》2014年第4期312-315,共4页Journal of Pathogen Biology

基　　金：国家自然科学基金项目(No.81260456)

摘　　要：目的了解大理地区结核分枝杆菌基因组中的数目可变串联重复序列(variable number tandem repeat,VNTR)即MIRU(mycobacterium interspersed repetitive unit)基因多态性,探讨MIRU-VNTR位点多态性的应用价值。方法采用PCR和琼脂糖凝胶电泳检测大理地区临床分离的60株结核分枝杆菌7个VNTR位点,采用MIRU-VNTR技术进行分型,利用Hunter-Gaston指数(HGI)对各MIRU进行分辨力评价,并应用Quantity one软件和BioNumerics6.6软件进行数字化和聚类分析。结果 60株结核分枝杆菌分为5个基因群(Ⅰ、Ⅱ、Ⅲ、Ⅳ、Ⅴ群)52个基因型。Ⅰ群占56.77%,含有29个基因型;Ⅱ群占25.00%,含有13个基因型;Ⅲ群占8.33%,含有5个基因型;Ⅳ群占6.67%,含有3个基因型;Ⅴ群占3.33%,含有2个基因型。7位点组合总分辨力为0.900,最高ETR-E位点0.735,最低ETR-C位点0.455。结论大理地区分离株结核分枝杆菌存在基因多态性,7位点MIRU-VNTR分型简便快速,分辨力高,适合用于大理地区结核分枝杆菌的基因分型检测。Objectives To determine the polymorphisms and proportion of variable numbers of tandem repeats（VNTRs）in genes of Mycobacterium tuberculosis isolates from Dali and to use different VNTR loci to genotype M.tuberculosis from Dali. Methods Sixty clinical isolates of M.tuberculosis from the Dali region were cultured in Lowenstein-Jensen medium.The isolates were genotyped based on VNTRs of mycobacterial interspersed repetitive units（MIRUs）and were evaluated using the Hunter-Gaston index（HGI）.Polymorphisms of 7VNTR loci in DNA samples were analyzed using PCR and 1.5%agarose gel electrophoresis.The clustering of genotypes was analyzed with Quantity One and BioNumerics 6.6software. Results Seven VNTR loci of 60 M.tuberculosis clinical isolates were analyzed.Results indicated that there were obvious polymorphisms of VNTRs.Genotype clustering indicated that these strains could be grouped into5gene clusters（Ⅰ,Ⅱ,Ⅲ,Ⅳ,and Ⅴ）and 52genotypes.Of these strains,56.77% were cluster Ⅰ,which included 29genotypes,25.00% were cluster Ⅱ,which included 13genotypes,8.33% were cluster Ⅲ,which included 5genotypes,6.67% were cluster Ⅳ,which included 3genotypes,and 3.33% were cluster Ⅴ,which included 2genotypes.The cumulative discriminatory power of the 7MIRU-VNTR loci was 0.900,with ETR-E having the highest（0.735）and ETRC having the lowest（0.455）.ETR-E resulted in the greatest resolving power,followed by ETRA,MIRU27,ETR-B,ETR-D,MIRU24,and then ETR-C. Conclusion Results indicated that there were obvious polymorphisms of VNTRs of clinical isolates of M.tuberculosis.This suggests that surveillance of prevalent genotypes needs to be enhanced.The 7MIRU-VNTR loci found in Dali may prove useful because of their convenience and discriminatory power.

关 键 词：结核分枝杆菌 基因分型 多位点可变串联重复序列 多态性 Hunter-Gaston指数 

分 类 号：R378.911[医药卫生—病原生物学]