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.