Ureaplasma urealyticum and male infertility: an animal model. I. Artificial infection, breeding experiments and histological preparation of organs.

Male Wistar rats were infected with Ureaplasma urealyticum, serotype 3 or 7, by injecting broth containing organisms into the urinary bladder following laparatomy. Animals were sacrificed 3, 7 and 21 days after infection. Ureaplasmas were detected in the organs of the genital tract by culture in 43% (serotype 3) and in 60% (serotype 7) of the animals. Type-specific ureaplasma antigen was detected in the genital organs in 44% (serotype 3) and 45% (serotype 7) of the animals. Control animals injected with sterile bouillon were negative for organisms and antigen. Male Wistar rats artificially infected with Ureaplasma urealyticum, serotype 3, were mated 3 and 6 months after infection with ureaplasma free female rats. The mating experiment revealed a smaller mean litter size and a lower birth weight in the offspring of infected males compared with the control animals, but no general influence on the fertility of infected animals.