Transmissible Diseases Laboratory, Center of Rural Health and Technology, UFCG, Federal University of Campina Grande, Paraíba, Brazil.
Department of Veterinary Sciences, UFPB, Federal University of Paraíba, Paraíba, Brazil.
Anim Reprod Sci. 2020 Aug;219:106530. doi: 10.1016/j.anireprosci.2020.106530. Epub 2020 Jun 27.
Leptospirosis is a globally distributed disease associated with reproductive failures in livestock; however, its pathogenesis has not been fully elucidated. Results from the present study indicate there is a presence of Leptospira sp. in organs and fluids of fetuses from ewes slaughtered in the semiarid region of Brazil. Twenty-nine fetuses from 23 ewes determined to be Leptospira sp.-positive using PCR were sampled (14 and 15 in dry and rainy seasons, respectively). Fetal samples of blood, central nervous system (CNS), lung, liver, spleen, stomach contents, peritoneal fluid, kidney, bladder, urine and reproductive system were collected. Diagnostic methods included the microscopic agglutination test (MAT), polymerase chain reaction (PCR) and bacterial isolation. Of the 29 fetuses, 24 (82.8 %) had at least one Leptospira sp.-positive organ or fluid, as determined using PCR, and of a total of 209 samples, 62 (29.7 %) contained leptospiral DNA. Of the 99 samples collected during the dry season, 42 (42.4 %) were positive, and of 110 samples collected during the rainy season, 20 (18.2 %) were positive (P = 0.0001). There was deoxyribonucleic acid (DNA) sequencing of three samples of kidney, CNS and liver, and in all of these, there was 99.3 % similarity with Leptospira interrogans. Leptospires were present in cultures of pooled samples from fetuses with deformities. Results indicate there is vertical (maternal-to-fetus) transmission which would represent an alternative transmission route for the spread of Leptospira sp. in ewes, suggesting molecular detection is essential in the investigation of leptospirosis in fetuses to identify animals that have been infected with this bacterium.
钩端螺旋体病是一种在全球范围内传播的疾病，与家畜的繁殖失败有关；然而，其发病机制尚未完全阐明。本研究结果表明，在巴西半干旱地区屠宰的母羊的胎儿器官和液体中存在钩端螺旋体。从 23 只经 PCR 确定为钩端螺旋体阳性的母羊中采集了 29 只胎儿样本（分别为干季和雨季各 14 只和 15 只）。采集了胎儿的血液、中枢神经系统（CNS）、肺、肝、脾、胃内容物、腹腔液、肾、膀胱、尿液和生殖系统样本。诊断方法包括显微镜凝集试验（MAT）、聚合酶链反应（PCR）和细菌分离。在 29 只胎儿中，24 只（82.8%）至少有一个 PCR 阳性的器官或液体，在总共 209 个样本中，有 62 个（29.7%）含有钩端螺旋体 DNA。在干季采集的 99 个样本中，有 42 个（42.4%）为阳性，在雨季采集的 110 个样本中，有 20 个（18.2%）为阳性（P = 0.0001）。对来自肾脏、中枢神经系统和肝脏的三个样本进行了脱氧核糖核酸（DNA）测序，在所有这些样本中，与钩端螺旋体 interrogans 的相似度为 99.3%。在胎儿畸形的混合样本培养物中存在钩端螺旋体。结果表明存在垂直（母体-胎儿）传播，这将是钩端螺旋体在母羊中传播的另一种传播途径，这表明分子检测对于调查胎儿钩端螺旋体病以识别已感染该细菌的动物至关重要。
