Abstract: Objective To investigate Chlamydia trachomatis infection and gene variants in child-bearing women in Beijing. Methods Endocervical samples were collected from 177 patients in a family planning clinic and a gynecologic clinic. C.trachomatis infection was screened with a fast diagnostic kit. Major outer membrane protein(MOMP) gene was amplified by a nested PCR. A 1.1kb amplified product was obtained and studied by restriction fragment length polymorphism analysis(RFLP). Variant domains of MOMP gene VS1,VS2,VS3,VS4 were sequenced with 373A automated sequencing system. Results C. trachomatis was found in 9 of 177 samples. Four samples were identified as F genotype, 3 E genotype and 2 D genotype. Variant domains of MOMP gene, VS1, VS2, VS3, VS4 were sequenced and the results were consistent with those of RFLP, however, mutations were found in MOMP gene in 4 samples. Conclusion C.trachomatis urogenital infection has been identified in a portion of child-bearing women in Beijing. C.trachomatis can be well genotyped with RFLP or gene sequencing of MOMP gene.

Key words: Chlamydia trachomatis, Major outer membrane protein, Polymorphism, restriction fragment length, Sequence analysis, DNA