12 novel atypical porcine pestivirus genomes from neonatal piglets with congenital tremors: A newly emerging branch and high prevalence in China.

Atypical porcine pestivirus (APPV), a newly discovered member of the genus Pestivirus, is considered to be associated with congenital tremors (CT) in piglets. From June 2016 to January 2018, 440 serum and tissue samples from CT-affected piglets in Anhui, Guangdong and Guangxi provinces were collected to detect APPV. The results showed a high level of 63.4% preference for APPV in 27 swine farms and complicated co-infection cases between APPV and other 12 swine viruses. Meanwhile, 12 novel APPV genomes were screened and identified. Results showed that complete genomes, Npro and NS5A genes of these novel 12 APPV sequences revealed 80.5%-99.8%, 78%-100% and 76.9%-99.8% nucleotide identities, respectively. Phylogenetic analyses based on sequences of full-length genomes, Npro and NS5A genes of APPV indicated three well-defined clades including a newly emerging branch in China. This study provides novel epidemiological information of APPV in China.

Detection and genome sequencing of porcine circovirus 3 in neonatal pigs with congenital tremors in South China.

Porcine circovirus 3 (PCV3) is a novel circovirus first discovered in the United States in piglets and sows with porcine dermatitis and nephropathy syndrome, reproductive failure, cardiac and multisystemic inflammation. Here, seven PCV3 strains were identified for the first time from neonatal pigs with clinical signs of congenital tremors (CT) in South China. The tissue tropism of PCV3 in CT-affected piglets was analysed by the real-time quantitative PCR, and the result showed that high loads of viral genomes were detected in the brains and hearts. The complete genomes of seven new PCV3 revealed 96.8%-99.6% nucleotide identities with eleven other PCV3 strains previously reported from the United States and China. Phylogenetic analysis based on the complete genome sequences showed that all PCV3 strains clustered together and were clearly separated from other circovirus species. This study reports on the first identification of PCV3 in CT-affected newborn piglets and provides the epidemiological information of neonatal piglets with CT in Guangdong and Guangxi Provinces of China.