71株浙江省结核分枝杆菌临床分离株MLVA基因分型研究

目的初步探讨浙江省结核分枝杆菌的数目可变串联重复序列（VNTR）的分型及分布特征。方法随机选取浙江省结核分枝杆菌临床分离菌株，常规培养，收集菌体，提取基因组DNA，采用聚合酶链反应（PCR）分别对VNTR位点进行检测分析，基因分型聚类分析采用BioNumerics软件。结果对71株结核分枝杆菌临床分离株的15个VNTR位点进行检测。结果显示明显的基因多态性。经基因聚类分析，可分4个基因群（I群、Ⅱ群、Ⅲ群、Ⅳ群），58个基因型。分别为I群占8．5％，含5个基因型，Ⅱ群占18．3％，含13个基因型，Ⅲ群占70．4％，含38个基因型，Ⅳ群占2．8％，含2个基因型。结论初步证实浙江省结核分枝杆菌VNTRs基因存在明显的多态性，至少存在4个VNTR型，主要流行型为Ⅲ型。

Analysis on the Genotyping of 71 Mycobacterium Tuberculosis Clinical Strains Isolated from Zhejiang Province with MLVA

Objective To investigate the genotyping and distribution pattern of the variable number tandem repeats （VNTR） of Mycobacterium tuberculosis clinincal isolates in Zhejiang province with Multiple - locus VNTR analysis （MLVA） preliminarily. Methods M. tuberculosis clinical isolates selected from Zhejiang province randomly were cultured with Lowenstein - Jensen medium. The bacteria from which the genome DNA was extracted were collected. The polymorphism of VNTR locus was tested in the DNA samples with PCR respectively. The clustering of genotype was analyzed with BioNumeries （ Version 5.0 ）. Chi - square test was used for statistical analysis. Results 15 VNTR loci of 71 M. tuberculosis clinical isolates were analyzd respectively. The results showed that there were obvious polymorphisms of VNTRs. The clustering of genotype showed that these strains could be categorized into 4 gene clusters （ I , Ⅱ, Ⅲ, IV ） and 58 genotypes. 8.5% were cluster I including 5 geno- types, 18. 3% were cluster Ⅱ including 13 genotypes, 70.4% were cluster Ⅲ including 38 genotypes, and 2. 8% were cluster IV including 2 genotypes. Conclusion The results showed that there were obvious polymorphisms of VNTRs of M. tuberculosis cilinical strains preliminarily. There were at least 4 clusters of VNTR genotype and cluster Ⅲ was the predominant prevalent strain in Zhejiang province.