Department of Microbiology, All India Institute of Medical Sciences, New Delhi, India.
Department of Dermatology and Venereology, All India Institute of Medical Sciences, New Delhi, India.
Indian J Med Res. 2019 May;149(5):662-670. doi: 10.4103/ijmr.IJMR_1171_17.
BACKGROUND & OBJECTIVES: Limited data are available on the typing of Chlamydia trachomatis in India. Serovars D to K of C. trachomatis are chiefly responsible for urogenital infections. Thus, this study was conducted to determine the distribution of C. trachomatis serovars in patients with urogenital infections and to characterize omp A gene of the detected C. trachomatis isolates by sequence analysis. Presence of other co-infections was also evaluated.
Endocervical swabs were collected from 324 women and urethral swabs/urine were collected from 193 men attending the sexually transmitted diseases outpatient clinic. The samples were screened for C. trachomatis by cryptic plasmid PCR and omp A gene PCR. Genotyping was performed by PCR-restriction fragment length polymorphism (RFLP) and sequencing of the omp A gene. Samples were screened for genital mycoplasmas, Neisseria gonorrhoeae, Treponema pallidum and human immunodeficiency virus (HIV).
C. trachomatis was found in 15.0 per cent men and 10.8 per cent women. Serovar D was the most prevalent followed by serovars E, F, I and G. Twenty two C. trachomatis isolates were selected for omp A gene sequencing. No mixed infection was found. Variability in omp A sequences was seen in 31.8 per cent cases. Both PCR-RFLP and omp A gene sequencing showed concordant results. The presence of Ureaplasma spp. and Mycoplasma hominis was observed in 18.7 and 9.5 per cent patients, respectively. Co-infection of C. trachomatis was significantly associated with Ureaplasma urealyticum and HIV.
INTERPRETATION & CONCLUSIONS: The high occurence of C. trachomatis infections warrants its screening in addition to other sexually transmitted infections namely U. urealyticum and HIV. Genotyping of the omp A gene may provide additional information for vaccine development.
印度有关沙眼衣原体（Chlamydia trachomatis）分型的数据有限。沙眼衣原体血清型 D 至 K 主要引起泌尿生殖道感染。因此，本研究旨在确定泌尿生殖道感染患者中沙眼衣原体血清型的分布，并通过序列分析对检测到的沙眼衣原体分离株的 omp A 基因进行特征描述。同时还评估了其他合并感染的情况。
从 324 名女性和 193 名男性的性传播疾病门诊采集宫颈拭子和尿道拭子/尿液。采用隐蔽质粒 PCR 和 omp A 基因 PCR 对样本进行沙眼衣原体筛查。通过 PCR-限制性片段长度多态性（RFLP）和 omp A 基因测序进行基因分型。对生殖器支原体、淋病奈瑟菌、梅毒螺旋体和人类免疫缺陷病毒（HIV）进行筛查。
男性沙眼衣原体感染率为 15.0%，女性为 10.8%。最常见的血清型为 D 型，其次是 E、F、I 和 G 型。选择 22 株沙眼衣原体分离株进行 omp A 基因测序。未发现混合感染。31.8%的病例 omp A 序列存在变异性。PCR-RFLP 和 omp A 基因测序结果一致。分别有 18.7%和 9.5%的患者存在解脲脲原体和人型支原体。沙眼衣原体的合并感染与解脲脲原体和 HIV 显著相关。
沙眼衣原体感染发生率较高，除了其他性传播感染（如解脲脲原体和 HIV）外，还需要对其进行筛查。omp A 基因分型可为疫苗开发提供更多信息。
