Shi Li, Fan Xin-jian, Wan Kang-lin
West China Medical School, Sichuan University, Chengdu 610041, China.
Zhonghua Liu Xing Bing Xue Za Zhi. 2007 May;28(5):477-81.
To investigate the application of the multiple locus variable numbers of tandem repeats (MLVA) in genotype Mycobacterium tuberculosis strains isolated from Tibet, and to understand the characteristics of genotype and distribution.
217 M. tuberculosis strains were collected from six regions of Tibet. Twenty tandem repeats loci in the total genome of M. tuberculosis (MTB) were analyzed by PCR and agarose gel electrophoresis method. The characteristics on polymorphism of DNA fingerprinting of 217 MTB strains were analyzed with BioNumerics 3.0 software.
217 M. tuberculosis strains detected with 20 MLVA loci were classified to 19 genotypes with 87.6% of the stains belonging to Beijing genotype and the other 18 genotypes were scattered,accounted for 1.38% and 0.92% strains, respectively. Beijing genotype was not significantly associated with the resistance to all of the four drugs and BCG vaccination.
It is concluded that the strains of MTB isolated in Tibet present definite polymorphism and most of the epidemic strains belonged to Beijing family genotype and MTB genotyping. The Beijing genotype was not recognized as the one transferred from some of the drug resistance strains or from BCG vaccination. Being a fast and simple technique, MLVA method, seemed a better molecular typing method and could be used for genotyping in M. tuberculosis and monitoring pathogen.
探讨多位点串联重复序列（MLVA）在西藏分离的结核分枝杆菌菌株基因分型中的应用，了解其基因分型特征及分布情况。
从西藏6个地区收集217株结核分枝杆菌菌株。采用聚合酶链反应（PCR）和琼脂糖凝胶电泳法分析结核分枝杆菌全基因组中的20个串联重复序列位点。用BioNumerics 3.0软件分析217株结核分枝杆菌菌株DNA指纹图谱的多态性特征。
217株结核分枝杆菌菌株经20个MLVA位点检测，分为19种基因型，其中87.6%的菌株属于北京基因型，其他18种基因型较为分散，分别占菌株总数的1.38%和0.92%。北京基因型与对四种药物的耐药性及卡介苗接种均无显著相关性。
得出结论，西藏分离的结核分枝杆菌菌株呈现出一定的多态性，大多数流行菌株属于北京家族基因型及结核分枝杆菌基因分型。北京基因型并非来自某些耐药菌株或卡介苗接种。MLVA方法作为一种快速简便的技术，似乎是一种较好的分子分型方法，可用于结核分枝杆菌的基因分型及病原体监测。
