结核分枝杆菌可变数目串联重复基因分型

Study on genityping of Mycobacterium tuberculosis strains isolated from patients of rural origin with variable number tandem repeat

目的运用可变数目串联重复(VNTR)分型方法研究农村结核病研究现场的结核分杆菌分离株的分子特征,分析与VNTR优势基因型相关的因素。方法经PCR扩增各分离株的5种确切串联重复位点(ETR-A^ETR-E)。根据扩增产物大小,确定各串联重复单元的拷贝数,得出每个菌株的VNTR基因型。结果研究现场的101株菌株共分为37个不同的VNTR类型,22名病人分离株为单一基因型,79名病人的菌株分属于15个簇,VNTR42435类型占研究菌株总数的38.6%,但该基因型与卡介苗(BCG)接种耐4种一线药的相关性差异均无统计意学义。结论VNTR分型方法简单快速、分型结果数字化,可以把研究菌株分为不同的群。尚不能认为VNTR 42435的优势来自某些抗痨药和BCG接种。

Objective To characterize the Mycobacterium tuberculosis （M.TB）isolates recovered from tuberculosis patients of rual morth Jiangsu province with variable-number tandem-repeat（VNTR）genotyping, and analyze factors related to the dominant VNTR genotype. Methods Five exact tandem repeat（ETR-A-ETR-E）loci were amplified by PCR and run on a Caliper 1 000 analyzer for all the isolates. VNTR genotype for every isolates were created by the copy number of each tandem repeats determind according to the size of PCR products. Results A total of 37 different allele ptofiles were identified by the VNTR for all the 101 isolates fell into 15 clusters. 38.6% of the strains studied were dominant VNTR pattern 42435,VNTR 42435 was not significantly associated with resistance to all the four drugs and BCG vaccination. Conclusion VNTR typing is a simple and rapid tool which generates numerical genotypes, It does enable M. TB isolates to be grouped into distinct groups. The advantages of the VNTR 42435 pattern cannot be considered to be coming from some drug resistanges or BCG vaccination.