Transmissão venérea de Toxoplasma gondii em camundongos experimentalmente infectados com oocistos da cepa ME49

Abstract

The objective of this study was to verify the venereal transmission of Toxoplasma gondii in mice experimentally infected with oocysts of the ME49 strain. The first experiment studied the presence and distribution of T. gondii in the reproduction organs of experimentally infected male mice, in the acute infection phase. Five experimental groups were formed (MG1, MG2, MG3, MG4 and CG-control), inoculated with 50, 100, 500 and 1000 oocysts, respectively. The proof of infection was carried out by an antibodies study and the presence of parasitic DNA in the blood, urine and reproductive tissues. Reproductive tissues were histologically evaluated for the study of suggestive lesions from the infection. Suggestive forms of T. gondii were observed in the urine at the 7th and 15th post-infection days. In the serology only one animal from the MG2 and all from MG3 and MG4 presented antibodies IgM and IgG. In the PCR-Nested, 80% of animals from MG1 and MG2 were positive in the DNA blood study and no animals from MG3 and MG4 were positive. None of the animals from the control group were positive in serology and molecular techniques. Of the males from the infected groups, 30% presented parasitic DNA in the prostate, 40% in the testicle and epididymis and 60% in the seminal vesicle. In the histopathology, testicular degeneration, focal mononuclear infiltration and more accentuated olygospermia were observed in the animals from MG3 and MG4, but not in the CG. The second experiment was carried out with the objective of studying the venereal transmission of T. gondii and the reproductive disturbances in female mice divided in four groups and mated with experimentally infected males between the 2nd and 14th post-infection days. The infection was proven by using the serology and molecular techniques. Histopathology was carried out in reproductive tissues of males (prostate, seminal vesicle, testicles and epididymis) and females (uterus and ovaries). One hundred percent of males presented parasitic DNA in tissues of the reproductive organ or in the blood. However, only one male inoculated with 100 oocysts and 10 inoculated with 500 and 1000 oocysts soroconverted, respectively. Reproductive problems were also observed in mated females, however, they did not present antibodies anti-T. gondii and 75% of them (23/40) were positive in the PCR-Nested. The results obtained in this study conclude that the venereal transmission of the parasite occurs in mice experimentally infected with the ME49 strain in the doses used.