Abstract: Objective To investigate the distribution of Chlamydia trachomatis genotypes in high risk populations of STDs from four cities in Southern China.Methods C.trachomatis was detected by a plasmid PCR in 1180 specimens collected in Hengyang,Shanghai,Guangzhou and Jiangmen,and then the major outer membrane protein gene (ompl) was amplified by nested PCR (nPCR) with plasmid-PCR-positive specimens.The amplicons of ompl were digested by restriction endonuclease Alu I,Msp I,EcoR I,or Dde I.C.trachoraatis was genotyped according to the restriction fragment length polymorphism (RFLP) patterns.Results Of 301 plasmid-PCR-positive specimens,286 (48 collected from Hengyang,32 from Shanghai,52 from Guangzhou and 154 from Jiangmen) could be genotyped.The most prevalent genotype was serotype E(30.8%),followed by J(23.8%),D(17.5%),F(10.5%),and G (6.2%).The distribution of various genotypes was not different among different cities.Conelusion Polymorphic genotypes of C.trachomatis are prevalent in Hengyang,Shanghai,Guangzhou and Jiangmen,and there is no significant difference of genotype distribution among these four cities.

Key words: Chlamydia trachomatis, Genes,ompl, Polymorphism,restriction fragment length