广西性病门诊患者泌尿生殖道沙眼衣原体株高分辨多位点测序分型研究

High-resolution multilocus sequence typing of urogenital Chlamydia trachomatis among STD clinic outpatients in Guangxi Zhuang Autonomous Region

目的：了解广西性病门诊患者中泌尿生殖道沙眼衣原体型别分布，同时对随访患者沙眼衣原体的感染情况进行分析。方法在广西壮族自治区皮肤病防治所收集泌尿生殖道沙眼衣原体感染患者，采集男性尿道和女性宫颈拭子标本，并对初筛阳性患者在治疗完成后进行随访和标本采集，同时采集患者基本信息和临床信息。应用QIAxtractor全自动核酸纯化仪提取DNA，巢式PCR扩增沙眼衣原体主要外膜蛋白基因（ompA）和MLST（高分辨多位点测序分型）所需的CT046（hctB）、CT058、CT144、CT172和CT682（pbpB）5个基因。对PCR产物进行序列测定，经序列比对和MLST型别分析获得菌株的ompA基因分型和型别，并用BioNumerics7软件对广西和意大利沙眼衣原体株绘制最小生成树。结果在44份来自初诊患者和6份来自随访患者的沙眼衣原体阳性样本中，42份成功进行沙眼衣原体ompA和MLST分型。共发现7种ompA基因型和15种hr-MLST分型的ST型别，其中有3种ST型别为首次报道。广西地区沙眼衣原体基因型别较意大利地区具有特征性。6例随访患者经分型方法鉴定3例为再次的新发感染，3例因未能成功进行基因分型而未能确诊。结论广西性病门诊患者感染的沙眼衣原体具有独特的型别，在随访中出现泌尿生殖道沙眼衣原体再感染病例。

Objective To investigate the type distribution of urogenital Chlamydia trachomatis（Ct）among STD clinic outpatients in Guangxi Zhuang Autonomous Region, and to estimate the prevalence of Ct infection among the patients during posttreatment follow-up. Methods Urethral and cervical swabs were collected from male and female outpatients with confirmed urogenital Ct infection, respectively, in Institute of Dermatology of Guangxi Zhuang Autonomous Region. The patients with positive results in preliminary screening tests were followed up after treatment, and specimens were collected at follow-up visits. General and clinical information was also obtained from these patients. DNA was extracted from these samples by using the QIAxtractor instrument. Nested PCR was performed to amplify the major outer membrane protein A（ompA）gene for ompA typing, and to amplify CT046（hctB）, CT058, CT144, CT172 and CT682 （pbpB） genes for high-resolution multilocus sequence typing （hr-MLST）. Then, PCR products were sequenced, and ompA and MLST types of Ct were determined by sequence alignment and MLST analysis, respectively. The obtained MLST sequence types （STs） were compared with those from an Italian population by using the BioNumerics7 software, and a minimum spanning tree（MST）was generated. Results Totally, 44 and 6 Ct-positive specimens were collected at first visits and follow-up visits respectively. Among the 50 specimens, 42 underwent successful ompA typing and hr-MLST, and 7 ompA genotypes and 15 hr-MLST STs were identified, including 3 first reported STs. The distribution of STs of Ct isolates from Guangxi Zhuang Autonomous Region was significantly different from that from the Italian population. Among the 6 followed patients with posttreatment Ct infection, 3 were confirmed to be reinfected with Ct, and the other 3 failed to be diagnosed because of unsuccessful genotyping. Conclusion The genotypes of Ct strains isolated from STD clinic outpatients in Guangxi Autonomous Region were characteristic, and Ct reinfection occurred in some patients during follow-up.