一种新型仔猪先天性震颤及其病原的初步研究

为了解国内猪群是否存在新型仔猪先天性震颤及其病原，本试验对临床疑似仔猪先天性震颤病例进行剖检，观察组织脏器的病理变化；根据GenBank上登录的瘟病毒基因组序列设计2对引物，以典型震颤仔猪的病料RNA为模板，进行RT-PCR，并对阳性产物进行测序；用DNAStar和Mega 7.0软件对所测序列进行分析，绘制系统进化树。结果表明，疑似仔猪先天性震颤病猪的组织脏器病理变化与猪瘟的病理变化相似，但无明显的脾脏梗死和淋巴结周边出血；从采集的病料中均扩增到与预期大小基本一致的条带；所测序列经BLAST比对，均为仔猪先天性震颤瘟病毒（APPV）的相应基因序列片段；系统进化树结果显示，哺乳动物瘟病毒可分为两大进化分支，APPV为单独一分支，其他瘟病毒为另一分支，两分支的同源性低于70%；所测的NS2-3和NS5B基因序列与GenBank上登录的APPV相应序列同源性在76.9%~98.8%之间，表明本研究所测定的序列是APPV的基因组序列；测定的7条NS2-3基因序列之间的同源性在89.7%~94.8%之间，12条NS5B基因序列的同源性在82.2%~100.0%之间。本试验首次证实国内猪群中存在新型仔猪先天性震颤病及其病原（APPV）。

Preliminary Study on a Novel Atypical Congenital Tremor of Piglets and Its Etiology

To investigate the infection of atypical porcine pestivirus (APPV) in China, autopsywas carried out for clinical suspected piglet of congenital tremor, viscera pathologic changes were observed. Two pairs of primersfor detection of the NS2-3 and NS5B genes by RT-PCR were designed according to the genome of APPV. The positive product was sequenced using DNAStar and Mega 7.0 softwares,and drawing the molecular evolution trees. The results showed that the lesions were similar to classical swine fever, but without infarction of the spleen and peripheral hemorrhage of the mandibular lymph node.Epidemic materials amplified products were consistent with the expected size, the sequences were APPV fragments by BLAST. APPV and other pestivirus belonged to two branch with the homologies about 70%. The homologies of NS2-3 and NS5B genes among the isolates and the APPV reference strains were about 76.9% to 98.8%, and the homologies of NS2-3 gene of 7 isolates were 89.7% to 94.8%,the homologies of NS5B gene of 12 isolates were 82.2% to 100.0%. This was the first report for the infection of APPV in piglets in China.