RESUMO
In this study, histopathological and immunohistochemical changes of the posterior vaginal fornix's and upper portion of the vagina were compared on rats infected with symptomatic and asymptomatic human isolates. Eighteen symptomatic and asymptomatic female isolates were used [nine/ each]. Two groups of infected female rats were included in this study [3 rats /isolate]. The results showed that there were no differences between symptomatic and asymptomatic isolates in histopathological changes; T. vaginalis of both isolates adhered to PAS epithelial cells at the surface and traversed under these cells. Both isolates were PAS and cathepsn D positive. By scanning electron microscopy many of T. vaginalis of the isolates adhered to microvilli of the epithelium cells in the same manner. Transmission electron microscopy proved that both isolates used the pseudopodia to adhere to the vagina upper part cells. The experimental infections did not differentiate between symptomatic and asymptomatic human isolates regarding histopathological and immunohistochemical changes