西藏藏族结核分枝杆菌临床分离株的MIRU-VNTR基因多态性分析与评价

Evaluation and analysis on genetic diversity of clinical Mycobacterium tuberculosis isolates from Tibetan patients by variable-number tandem repeats of mycobacterial interspersed repetitive units

目的了解西藏地区藏族人群中结核分枝杆菌24位点MIRU-VNTR的基因多态性及其评价。方法应用欧盟推荐的24位点MIRU-VNTR分型方法,将本次分型结果与MIRU-VNTRplus数据库进行比对,并应用BioNumerics5.0软件进行聚类分析。结果 577株结核分枝杆菌分为347种基因型,其中299株分为69个基因簇,另278株表现为独特的基因型。MIRU31、Qub11b2、Qub26、Qub4156c、Mtub21、MIRU20和MIRU26七个位点对西藏地区藏族人群中结核分枝杆菌临床分离株的分辨力较高,另17个位点的分辨力较低,其中MIRU24位点分辨率为0。结论西藏地区藏族人群中结核分枝杆菌MIRU-VNTR分型具有良好的多态性,且该地区以现代型结核分枝杆菌为流行优势菌。

The genetic diversity of Tibetan clinical Mycobacterium tuberculosis （M. tuberculosis） was analyzed by varia- ble-number tandem repeats of mycobacterial interspersed repetitive units （MIRU-VNTR） with 24 loci. A total of 577 clinical Mycobacterium tuberculosis isolates were collected from Tibetan patients with tuberculosis for genotyping by means of the 24 loci MIRU-VNTR, and the results were analyzed by BioNumerics 5.0 and then blasted with the data of MIRU-VNTR plus in website of http..//www, miru-vntrplus, org. Of 577 M. tuberculosis strains were identified as 347 genotypes, in which 299 strains were identified as 69 genetic clusters and 278 strains showed unique genotype. Seven loci of MIRU31, Qubllb2, Qub26, Qub4156c, Mtub21, MIRU20, and MIRU26 had high discriminatory power for Tibetan M. tuberculosis, the discrimi- natory power Of other loci were low, and the discriminatory power of MIRU24 was zero. There are significant genetic diversi- ties of Tibetan M. tuberculosis with MIRU-VNTR analysis, and modern M. tuberculosis Beijing genotype was prevalent in Ti- bet areas.