Novel Recombinant Seneca Valley Virus Isolated from Slaughtered Pigs in Guangdong Province

Seneca valley virus (SVV) associated porcine idiopathic vesicular disease showed increasing geographic distribution in major pig-raising countries and it is important to monitor the epidemic strains. Here, two newly identified recombinant SVV strains, CH-GDFS-2018 and CH-GDJY-2018, which were isolated from slaughtered pigs in Guangdong Province, were performed genetic, phylogenetic and recombination analyses to determine their characterization. Genetic analysis revealed that CH-GDFS-2018 was closely related to KS15-01 and US-15-39812IA, while CH-GDJY-2018 was closely related to SVA/CHN/07/2017. Phylogenetic analysis indicated that these two strains were clustered with previous strains circulating in China in 2017 and belonged to the US SVV branch. Recombination analysis showed that the genome of CH-GDFS-2018 consisted of two fragments from USA-IA46008/2015-Passage 1 and one fragment from CH-GDYD-2017. Similarly, the recombinant genome of CH-GDJY-2018 consisted of two fragments from SVA-CHN-07-2017 and one fragment from GD01-2017. Although the significance of recombination in different regions of SVV genome needs further research, the findings of recombinant strains may help in developing better prevention strategies against outbreaks.