Genotyping of Chlamydia trachomatis strains from male patients with urethritis in sexually transmitted disease clinic / 中华皮肤科杂志

ABSTRACT

Objective To investigate the serovar distribution of Chlamydia trachomatis (Ct) isolated from male patients with urethritis in sexually transmitted disease (STD) clinic.Methods Urine specimens were collected from male patients with urethritis in STD clinic at Hospital of Dermatology,Chinese Academy of Medical Sciences between January 2013 and December 2013.Fluorescence-based quantitative PCR was performed to detect Ct DNA in these specimens.DNA was extracted from Ct-positive urine specimens,and nested PCR was conducted to amplify the VS1-VS2 regions of the outer membrane protein A (ompA) gene,followed by gene sequencing.The resulting sequences were aligned to reference sequences by the DNAStar5.0 software to determine Ct serovars.Results A total of 432 urine specimens were collected,and 33.1％ (143/432) of them were positive for Ct.The VS1-VS2 regions of the ompA gene were amplified from 127 out of the 143 Ct-positive specimens,but not from the other 16 specimens.Nine serovars were identified by gene sequencing among the 127 specimens,including serovar E (29 strains,22.83％),F (28 strains,22.05％),D (19 strains,14.96％),G (16 strains,12.60％),J (16 strains,12.60％),K (8 strains,6.30％),H (5 strains,3.94％),I (3 strains,2.36％) and B (3 strains,2.36％),and Ct serovars E,F,D,J and G accounted for 85.02％ among all the strains.Synonymous mutations were identified in 14 out of the 127 strains when compared with reference strains.Conclusions E,F,D and G serovars were the main Ct serovars in male patients with urethritis in STD clinic.The proportion of Ct serovar E strain was decreased,but that of serovar J strain was increased compared with 20 years ago.