Stevenson G W, Kiupel M, Mittal S K, Choi J, Latimer K S, Kanitz C L
Department of Veterinary Pathobiology, Purdue University, West Lafayette, IN 47907, USA.
J Vet Diagn Invest. 2001 Jan;13(1):57-62. doi: 10.1177/104063870101300111.
Congenital tremors (CT) type A2 is associated with porcine circovirus (PCV) and deficient and abnormal myelin. The aim of this study was to determine the tissue distribution and genetic type of PCV in 1-2-day-old pigs with naturally occurring CT type A2 using in situ hybridization, polymerase chain reaction (PCR), and indirect fluorescent antibody tests on frozen tissue sections. CT-affected and clinically normal pigs were selected from 4 farms in the midwestern USA that were undergoing outbreaks of CT type A2. All CT and most normal pigs were infected with PCV. PCV was widely distributed in tissues of infected pigs and was most common in tissues of the central nervous system and liver. In all infected pigs, there were more PCV-infected cells in brain and spinal cord than in nonneural tissues. CT pigs had many more PCV-infected cells in the brain and spinal cord than did clinically normal pigs because of a more diffuse distribution and a larger proportion of infected cells. The cells most commonly infected with PCV in brain and spinal cord were large neurons. In nonneural tissues, macrophages were the most frequent cell type infected. PCR analysis demonstrated only PCV type 2 and not PCV type 1 in all PCV-infected pigs on all 4 farms.
A2型先天性震颤（CT）与猪圆环病毒（PCV）以及髓磷脂缺乏和异常有关。本研究的目的是通过对冷冻组织切片进行原位杂交、聚合酶链反应（PCR）和间接荧光抗体检测，确定自然发生A2型CT的1 - 2日龄仔猪中PCV的组织分布和基因类型。从美国中西部4个正在爆发A2型CT的农场中选取受CT影响和临床正常的仔猪。所有受CT影响的仔猪以及大多数正常仔猪都感染了PCV。PCV广泛分布于感染仔猪的组织中，在中枢神经系统和肝脏组织中最为常见。在所有感染仔猪中，脑和脊髓中的PCV感染细胞比非神经组织中的更多。由于分布更广泛且感染细胞比例更大，患CT的仔猪脑和脊髓中的PCV感染细胞比临床正常仔猪多得多。脑和脊髓中最常被PCV感染的细胞是大神经元。在非神经组织中，巨噬细胞是最常被感染的细胞类型。PCR分析表明，在所有4个农场的所有PCV感染仔猪中，仅检测到PCV2型，未检测到PCV1型。
