Histopathological changes in the lower genital tract. a Vagina, day 3 PI, haematoxylin and eosin (HE), showing subepithelial stromal and perivascular infiltrations of mononuclear, lymphoid cells, and dilated lymphatic vessels (*); b Vagina, day 3 PI (serial section of a): IHC staining of CD3 showing positive staining in some, but not all of the infiltrating cells (arrows); c Vagina, day 3 PI, HE, showing neutrophils extravasating in the subepithelial stroma (enlarged in insert, arrow); d Vagina, HE, control tissue; e Cervix, day 5 PI, HE, showing a dense subepithelial infiltrate of mononuclear cells (arrowhead); f Cervix, HE, control tissue. Genital tract lesions in sexually mature G ö ttingen minipigs during the initial stages of experimental vaginal infection with Chlamydia trachomatis serovar D. BMC Veterinary Research. Not Altered. CC.