Abstract:

Objective To establish a mouse model for genital tract infection with different serovars of Chlamydia trachomatis （Ct）, and to provide a basis for understanding the relationship between Ct serovars and virulence. Methods Six-week-old female BALB/c mice were divided into 4 groups: study group （pretreated with progesterone and inoculated with 4.0 × 107 inclusion-forming units （IFU） of Ct serovar E, F, J and K, respectively）, progesterone-control group （pretreated with progesterone and inoculated with culture medium of McCoy cells）, non progesterone-control group （inoculated with 4.0 × 107 IFU of Ct serovar F）, blank control group receiving no treatment. At 4 and 7 days after the inoculation, the appearance of vulva was observed, vaginal swab specimens were obtained and subjected to cell culture, direct immunofluorescence assay and real-time fluorescence-based PCR for the detection of Ct. Results A slight inflammation of the genital tract was observed in the mice 4 days after the inoculation with Ct serovar E, F, J or K in the study group. Cell culture, direct immunofluorescence assay and real-time fluorescence-based PCR all confirmed that Ct was present in vaginal specimens from the study group, but absent from the control groups. The longest duration of infection was 21 days in 1 out of 11 mice inoculated with Ct serovar K, followed by 17 days in 1 out of 11 mice inoculated with Ct serovar J, 14 days in 5 out of 11 mice with Ct serovar F and in 2 out of 11 mice with Ct serovar K. Conclusion The model for genital tract infection with different serovars of Ct can be established in mice at a right age by pretreatment with progesterone and inoculation with a certain amount of Ct.

Key words: Model