Pathogenesis of Trichomonas vaginalis: Investigation in a modified mouse model and the interaction with Lactobacillus acidophilus.

Abstract

Recent work with a mouse model of T. vaginalis indicated that only 25% of mice harbour Lactobacillus spp. and T. vaginalis introduced in the vagina persisted for about 7 days after which it was rapidly eliminated. In an attempt to establish a better model of intravaginal infection that resembles human disease we established Lactobacillus acidophilus in estrogenized Balb/c mice. Rates of T. vaginalis infection in this group were then compared to a control group of mice who were not treated with L. acidophilus. The addition of L. acidophilus did not significantly alter the resident mouse vaginal flora. The interaction observed in the model between T. vaginalis and L. acidophilus was then examined in in-vitro competitive assays between the two organisms. Interesting was the deleterious effect of T. vaginalis on L. acidophilus seen in the combined cultures with the reduction in bacteria seen at a much greater rate than in matched controls. Finally, this modified model was employed in preliminary immunological studies of T. vaginalis infection. Mice immunized with T. vaginalis prior to intravaginal challenge were less likely to develop infection than controls. (Abstract shortened by UMI.)