Study on the transmission of Toxoplasma gondii by semen in rabbits

To confirm the transmission of Toxoplasma gondii by semen and to investigate the impact of vaginal status on the transmission of T. gondii in female rabbits.

Sixteen male rabbits were infected with T. gondii by intraperitoneal injection each with 1 x 10(5) RH tachyzoites. Eight rabbits died in 8-14 d after infection. unde Artificial vagina was used to collect semen from male rabbits weekly before and after infection for 8 weeks. If more than 2 portions of semen from 8 survived male rabbits were collected after infection, the collected semen was mixed weekly for later use. Twenty-seven female rabbits were divided into 4 groups: group 1 with normal vagina (7 rabbits), group 2 with wounded vagina (7), group 3 with trichomonas vaginitis (7) and group 4 with colpomycosis infection (6). Tachyzoites were found in mixed semen digested by trypsinate, and were used for endovaginal artificial insemination to female rabbits by uterine cavity tube once a week for 8 consecutive weeks. 2-3 d after every insemination, 2 ml blood was collected from helix vein of each rabbit, and stored at -40 degrees C for use. Anti-T. gondii antibody was examined by ELISA and the B1 gene of T. gondii was detected by PCR.

Anti-T. gondii antibody was detected in some rabbits be (2, 3, 1, and 1 rabbits from each of the groups respectively) on the 16th day after the first insemination. The positive rate of ELISA was 25.9%. The amplification of B1 gene (200 bp) by PCR appeared positive from the blood samples on the 3rd day after the first insemination and the last positive one was proved on the 51th day after the first insemination. Number of positive samples was 2, 1, 3 and 1 in the 4 groups respectively, with an overall PCR positive rate of 18.5%. Only 3 of the 27 rabbits were positive by both ELISA and PCR.

T. gondii can be transmitted by semen and the health status of vagina shows no impact on it.