Gottstein B, Hentrich B, Wyss R, Thür B, Bruckner L, Müller N, Kaufmann H, Waldvogel A
Institut für Parasitologie, Universität Bern.
Schweiz Arch Tierheilkd. 1999;141(2):59-68.
Cyst-forming coccidia may cause significant losses in livestock, primarily due to abortion, loss of young animals and neuromuscular diseases. Rather recently, Neospora caninum has been recognized as one of the major protozoal abortion-inducing parasites in cattle. The present study addressed the performance of different diagnostic tools (in vitro-cultivation; histology; immunohistochemistry; serology; PCR) suitable for the direct or indirect detection of N. caninum. By PCR, Neospora-DNA was detected in 24 brains (29%) from 83 bovine abortion, many of these brains were simultaneously characterized by histopathological findings typical for a protozoal, cerebral parasitosis. The diagnostic methods were furthermore assessed using samples of different tissues and body fluids from three experimentally Neospora-infected pregnant cows and their foetuses. The diaplacental passage of N. caninum to the foetus was successful in two of the three cases. In these two cases, PCR was positive for different foetal organs and, additionally, for the abomasal and amniotic fluid. The successfully infected cows developed anti-Neospora serum antibodies between 10 and 17 days post infection, foetuses remained serologically negative in all cases. The results obtained in the present study demonstrated the usefulness of PCR, complemented by serology, for the specific diagnosis of bovine neosporosis. Such tests may prove suitable to perform epidemiological investigations. Taken together, our data indicated that prenatal neosporosis may be an important cause of infectious bovine abortion in Switzerland.
形成囊肿的球虫可能会给家畜造成重大损失，主要原因是流产、幼畜死亡和神经肌肉疾病。最近，犬新孢子虫已被确认为牛体内主要的导致流产的原生动物寄生虫之一。本研究探讨了适用于直接或间接检测犬新孢子虫的不同诊断工具（体外培养、组织学、免疫组织化学、血清学、聚合酶链反应）的性能。通过聚合酶链反应，在83例牛流产病例的24个大脑（29%）中检测到新孢子虫DNA，其中许多大脑同时具有原生动物脑寄生虫病的典型组织病理学特征。此外，还使用来自三只经实验感染新孢子虫的怀孕母牛及其胎儿的不同组织和体液样本对诊断方法进行了评估。在三个病例中的两个病例中，犬新孢子虫成功地通过胎盘传递给了胎儿。在这两个病例中，聚合酶链反应对不同的胎儿器官呈阳性，此外，对皱胃和羊水也呈阳性。成功感染的母牛在感染后10至17天产生了抗新孢子虫血清抗体，所有病例中的胎儿血清学检测均为阴性。本研究获得的结果表明，聚合酶链反应辅以血清学对牛新孢子虫病的特异性诊断是有用的。此类检测可能适合进行流行病学调查。综上所述，我们的数据表明，产前新孢子虫病可能是瑞士传染性牛流产的一个重要原因。
