中文摘要：

【目的】对青海藏区沙眼患者标本进行沙眼衣原体分离培养与鉴定。【方法】分别采集患者的单眼结膜和结膜囊拭子标本至1 mL样本保护培养基中。取50μL样本采用离心法感染BGM细胞,37°C培养72 h,连续传代3次,相差显微镜观察衣原体包涵体。对临床样本和分离株分别进行主要外膜蛋白基因ompA序列分析。【结果】共采集了45例活动性沙眼患者的115份临床样本,其中54份样本为ompA PCR阳性,15份样本为沙眼衣原体培养阳性。ompA分析发现,青海藏区沙眼衣原体有3个不同的同源ompA变异株,均为基因B型,都包含有一个泌尿生殖道型沙眼衣原体特有密码子。分离株QH111L和QH111R分别来自编号111患者的左眼和右眼样本,它们ompA基因的可变区有一个非同义碱基差异。该碱基变异仅存在于111号患者的左眼样本中,说明QH111L可能是新出现的ompA突变体。【结论】青海藏区的眼型沙眼衣原体流行株为基因B型,至少存在3个不同的ompA变异株。从青海藏区分离培养了15株眼型沙眼衣原体,发现同一患者的左右眼样本中的沙眼衣原体有不同ompA。本研究为研制沙眼疫苗和诊断试剂奠定了基础,也将有助于理解沙眼的进化和传播。

英文摘要：

[Objective] To isolate and characterize ocular Chlamydia trachomatis from trachoma samples of Tibetan children from Qinghai province. [Methods] Swabs of left and right conjunctivas and conjunctival sacs were collected into one milliliter of transportation media. Fifty microliters of each sample were used to infect BGM cells by using centrifugation. Infected cells were cultured at 37 ℃ for 72 h, and were passaged for three successive times. Chlamydial inclusions were observed using phase microscopy. Chlamydial cultures and clinical samples were characterized by using ompA gene sequence analyses. [Results] A total of 115 samples from 45 trachoma patients were collected. 54 samples were ompA-PCR positive and 15 samples were culture positive. All ompA genes of these samples belong to genotype B, are grouped into 3 variants and have a UGT-type codon. Chlamydial isolates QHlllL and QHlllR were from left and right conjunctival samples of No. 111 patient, respectively, but their ompA genes have a nonsynonymous base difference. This single nucleotide change was only found in left conjunctiva of No. 111 patient, suggesting that QHlllL may be a newly emerged ompA variant. [Conclusion] 15 ocular Chlamydia trachomatis strains were isolated from Tibetan children of Qinghai. All strains belong to genotype B and three different ompA variants. Isolates from a same patient＇s separate conjunctivas were found to have different ompA genes. Identification and characterization of these newly isolated strains will further our understanding of trachoma epidemiology and evolution.