Genotyping of Endocervical Chlamydia trachomatis Strains and Detection of Serological Markers of Acute and Chronic Inflammation in Their Host

Background: Chlamydia trachomatis (C. trachomatis) is the most prevalent cause of bacterial sexually transmitted infections (STI) recognized throughout the world. The aim of this study is to determine different genotypes of genital C. trachomatis and the association between the serological markers of inflammation and genotypes of C. trachomatis in sexually active women (n=80) attending Shahid Beheshti Hospital in Isfahan, Iran. Materials and Methods: In this descriptive study, endocervical swabs were collected from 80 women. There were 17 endocervical samples that showed positivity for C. trachomatis by plasmid polymerase chain reaction (PCR) using KL1 and KL2 primers. The omp1 gene was directly amplified in 17 plasmid PCR positive samples and was used to differentiate the clinical genotypes by omp1 gene PCR-restriction fragment length polymorphism (PCR-RFLP). The levels of IgG and IgA specific to C. trachmatis and C-reactive protein (CRP) were evaluated. Results: Based on restriction-digestion patterns, four genotypes were identified. Genotypes E (35.3%) and F (35.3%) were the most prevalent, followed by D/Da (23.5%) and K (5.9%). There was no significant association between genotypes and the presence of IgG and CRP. Patients infected with genotype E showed a serological marker of chronic inflammation, i.e. IgA seropositivity, significantly more than patients infected with other genotypes (p=0.042). Conclusion: Nested PCR could increase the sensitivity of omp1 amplification. Based on the presence of IgA, chronic C. trachomatis infections were observed more frequently among genotype E-infected patients in our population.