Sequence analysis and genotyping of genital Chlamydia trachomatis among patients with suspected-Neisseria gonorrhoeae

Abstract

Objective To understand the prevalence rate of genital Chlamydia trachomatis among a population with suspected-Neisseria gonorrhoeae infection,the distribution of Chlamydia trachomatis genotypes,assess changes in omp1 sequences among patients with Neisseria gonorrhoeae and Chlamydia trachomatis coinfections.Methods Four hundred and one swabs were collected.Chlamydia trachomatis and Neisseria gonorrhoeae were detected by Roche Amplicor System.DNA were extracted from those samples and were amplified by nested PCR.PCR products were sequencing and analyzed by software Mega4.0.Results The prevalence of genital Chlamydia trachomatis infection,Neisseria gonorrhoeae infection and coinfection with genital gonorrhoea and genital chlamydia were 82.3%,24.2% and 21.7% each.Eight genotypes were identified in 73 sequences,including E(27.4%),G/Ga(23.3%),D/Da(16.4%),F(13.7%),J (11.0%),H(5.5%),B and K(each 1.4%).Sequencing analysis showed that 3 cases(4.1%) had missense mutation,including genotype D/Da,E,G/Ga.Genotypes F,H,J and K were more variable,however,most of them were silent mutation.Conclusion The prevalence rate of genital Chlamydia trachomatis among a population with Neisseria gonorrhoeae infection was high.The most common genotypes were genotype E,G/Ga,D/Da and F; Sequencing analysis has provided a tool for the molecular epidemiology of genital Chlamydia trachomatis infections. Key words: Gonorrhea; Chlamydia trachomatis; Nested-PCR; Genotyping; Sequencing analysis