Histopatology of the reproductive tract of Nellore pubertal heifers with genital ureaplasmosis

ABSTRACT In order to study and characterize the lesions in the reproductive tract of Nellore heifers naturally infected with Ureaplasma diversum and presenting granular vulvovaginitis syndrome (GVS), fragments of uterine tube, uterus, cervix, vagina and vulva of 20 animals were evaluated. The macroscopic lesions of the vulvovaginal mucosa were classified in scores of “1” mild, until “4”, severe inflammation and pustular or necrotic lesions. The histopathological evaluation was performed using scores of “1” to “4”, according to the inflammatory alterations. The fragments with severe microscopic lesions (3 and 4) were from the uterine tubes and uterus, which showed leukocytes infiltration and destruction and/or necrosis of epithelium. Alterations in the lower reproductive tract fragments were mild, but characteristics of acute inflammatory processes. The histopathological findings of the reproductive tract of females naturally infected with Ureaplasma diversum are consistent with injuries that compromise the environment from the local where spermatozoa acquires ability to fertilize an oocyte until those where the oocyte is fertilized. Therefore, animals with GVS should be identified early in the herd, because, besides the reduction in the fertility rates caused by tissue damages, they can contribute to disseminate the microorganism. Key words: bovine, tissue evaluation, reproduction, Ureaplasma diversum.摘要 为研究自然感染多样性脲原体（Ureaplasma diversum）且表现出颗粒性外阴阴道炎综合征（GVS）的内洛尔青年母牛生殖道病变特征，本研究对20头试验牛的输卵管、子宫、子宫颈、阴道及外阴组织片段进行了评估。外阴阴道黏膜的肉眼病变按严重程度分为1级（轻度）至4级（重度炎症伴脓疱或坏死性病变）。根据炎症变化情况，本研究采用1至4级评分法开展组织病理学评估。存在重度显微病变（3级和4级）的组织片段取自输卵管与子宫，其病理表现为白细胞浸润、上皮破坏及/或上皮坏死。下生殖道组织片段的病变程度较轻，但仍呈现急性炎症过程的特征。自然感染多样性脲原体的雌性个体生殖道组织病理学结果，与精子获能位点至卵子受精位点间的生殖道微环境受损的病理变化一致。因此，牛群中应尽早检出表现为GVS的个体：此类个体不仅会因组织损伤导致生育率下降，还可促进该微生物的传播扩散。 关键词：牛、组织评估、生殖、多样性脲原体