Abstract:

Gao Xibo, Xiao Meng, Zhang Xinmei, Ma Jingyue, Wang Jing, Liu Quanzhong, Qi Manli. Department of Dermatovenereology, General Hospital, Tianjin Medical University, Tianjin 300052, China 【Abstract】 Objective To optimize immunodominant protein combinations for serological screening for Chlamydia trachomatis （Ct） infection. Methods Both serum and genital swab samples were collected from 50 patients with Ct infection confirmed by colloidal gold immunochromatographic assay （GICA）, and 30 GICA-negative clients without Ct infection at a sexually transmitted disease （STD） clinic in Tianjin Medical University General Hospital. The 30 serum samples from GICA-negative clients were also negative for microimmunofluorescence （MIF） assay. Eight Ct immunodominant proteins, including Pgp3, CPAF, CT143, CT101, CT694, CT875, CT813 and IncA, were selected as antigens to detect corresponding antibodies in the serum samples by enzyme-linked immunosorbent assay （ELISA） with the Ct proteins Hsp60 and major outer membrane protein （MOMP） as references. The results of ELISA were compared with those of the traditional gold standard method MIF assay to determine the immunodominant protein combination with the highest sensitivity and specificity. Results Of the 50 serum samples from patients with Ct infection, 44 were positive and 6 negative by MIF. The results of ELISA with the combination of immunodominant proteins Pgp3, CT694 and CT875 as antigens were 97.73% （43/44） consistent to those of MIF assay. Of the 30 serum samples from GICA-negative clients, all were negative by MIF. Meanwhile, no antibody was detected against any of the immunodominant proteins Pgp3, CT694 and CT875 in any of the serum samples from GICA-negative clients. Conclusions The ELISA with the combination of immunodominant proteins Pgp3, CT694 and CT875 as antigens has good sensitivity and specificity for serological screening for Ct infection, and is simple to operate and easy to popularize.