沙眼衣原体omp1基因VS1-VS2序列分析与基因分型

Genotyping of Chlamydia trachomatis by sequence analysis of VS1-VS2 region of omp1 gene

目的探讨沙眼衣原体omp1基因VS1-VS2序列基因分型和VS1-VS2基因突变率。方法巢式PCR扩增omp1基因的VS1-VS2序列,自动测序仪测序,运用DNAstar软件进行临床菌株与标准菌株序列的比对。结果99株临床标本分离株扩增出约453 bp大小的VS1-VS2片段。与标准株比对,除3株测序出现双峰无法确定基因型外,96株菌株分为9个型,以F型29株(30.2%)、E型22株(22.9%)、J型19株(19.8%)、D型12侏(12.5%)和H型8株(8.3%)为主。序列分析发现7株存在VS1区碱基的突变或插入,多为有义突变,突变率为7.3%,多见于D、E、F和H型。结论沙眼衣原体omp1基因序列分析在分子流行病学上具有一定意义。

Objective To type clinical strains of C. trachomatis by sequence analysis of VS1-VS2 region of ompl gene, and to investigate the mutation rate of this gene. Methods Urogenital specimens were collected from 99 patients attending our STD clinic. The VS1-VS2 region of ompl gene was amplified in these specimens by nested PCR, and sequenced with an automatic sequencer. The sequencing results were blasted against sequences of reference strains by DNAstar software. Results A 435-bp fragment of VS1-VS2 region was amplified from all 99 clinical samples. Three specimens appeared to contain multiple pathogens and could not be genotyped. The remaining 96 strains were classified into 9 genotypes. The most prevalent types in decreasing order were F （ 29, 30.2%）, E （22, 22.9% ）, J （19, 19.8% ）, D （12, 12.5% ） and H （ 8, 8.3% ）. Seven （ 7.3% ） strains showed base mutation or insertion in VS1 region, most of which were sense mutation and primarily occurred among genotypes D, E, F and H. Conclusion Sequencing analysis of omp 1 gene may be useful in the molecular epidemiology of C. trachomatis infection.