Novel real-time polymerase chain reaction assay for quantitative detection of Chlamydia trachomatis in vaginal and cervical secretions

Chlamydia trachomatis (C. trachomatis) is an important sexually transmitted disease pathogen associated with infertility and several urogenital infectious diseases. A variety of detection methods have been developed for C. trachomatis, including the isolated cell culture method, PCR, and real-time polymerase chain reaction (RT-PCR). These methods have inherent limitations, however. The current study developed a novel RT-PCR assay specific for quantitative detection of C. trachomatis elementary bodies (EBs) in vaginal and cervical secretions without DNA extraction. Based on homology analysis between Chlamydia and other common genital tract infectious pathogens, oligonucleotide primers were designed to target the C. trachomatis ompA(70-213) (ompA1) gene. These primers were confirmed in HeLa 229 cells infected with C. trachomatis and in a mouse model of genital C. trachomatis infection. Moreover, RT-PCR was used to detect C. trachomatis in vaginal and cervical secretions from 86 female patients. These results were compared with those of the traditional C. trachomatis isolated cell culture method, evaluating the sensitivity and specificity of this novel RT-PCR assay. The ompA1 gene was found to have high homology across several Chlamydia serotypes. The newly developed RT-PCR assay provided highly sensitive detection of EBs in genital tracts of the mouse model and in vaginal and cervical secretions of the 86 female patients, compared with the traditional detected method.