Ho M S, Barr B C, Rowe J D, Anderson M L, Sverlow K W, Packham A, Marsh A E, Conrad P A
Department of Pathology, Microbiology and immunology, School of Veterinary Medicine, University of California, Davis 95616, USA.
J Parasitol. 1997 Jun;83(3):508-14.
Neospora sp. can cause fetal abortion or neurological disease in congenitally infected calves. Latent tissue stages in infected cows may contribute to vertical transmission of Neospora sp. from dam to offspring in multiple pregnancies. In this investigation, the polymerase chain reaction (PCR) and Neospora-specific assay were employed to detect Neospora sp. by amplification of nuclear small-subunit rRNA gene sequences in infected cattle tissues. Tissues from 11 cattle, including 6 experimentally and 2 naturally infected cows, 1 naturally infected newborn calf, and 2 uninfected control cows, were evaluated in this study. Neospora-specific PCR products were amplified from DNAs of different bovine tissues, including brain, spinal cord, heart, lung, kidney, diaphragm, skeletal muscle, and placenta, as well as amniotic fluid samples of infected cattle. The PCR-based amplification and probe hybridization system proved useful in assessing the location of tissue-stage parasites in naturally and experimentally infected cattle, even when Neospora sp. antibody titers fall below normal cut-off values by an indirect immunofluorescent antibody test.
新孢子虫可导致先天性感染犊牛出现流产或神经疾病。感染母牛体内的潜伏组织阶段可能会导致新孢子虫在多次妊娠中从母体垂直传播给后代。在本研究中，采用聚合酶链反应（PCR）和新孢子虫特异性检测方法，通过扩增感染牛组织中的核小亚基rRNA基因序列来检测新孢子虫。本研究评估了11头牛的组织，包括6头实验感染和2头自然感染的母牛、1头自然感染的新生犊牛以及2头未感染的对照母牛。从不同牛组织的DNA中扩增出新孢子虫特异性PCR产物，这些组织包括脑、脊髓、心脏、肺、肾、膈肌、骨骼肌和胎盘，以及感染牛的羊水样本。基于PCR的扩增和探针杂交系统被证明可用于评估自然感染和实验感染牛体内组织阶段寄生虫的位置，即使通过间接免疫荧光抗体试验检测到新孢子虫抗体滴度低于正常临界值时也是如此。
