Detection and analysis of antigen and antibody of Seneca virus from a pig farm in Yangjiang

Seneca virus A(SVA) is a newly discovered picornavirus that produces similar vesicle-like lesions in pigs and causes death of piglets. In recent years it outbroke and showed a trend of spread . The tissues and serum were collected from a pig farm in Yangjiang, for testing and analysis. A specific single band was amplified from RT-PCR of the VP1-2A gene of Seneca virus. Sequence analysis of PCR products showed that this stain was most homologous （99.2%）with USA/GBI29/2015, a strain from USA in 2015, and showed 97.1% homology with CH-HN-2017, a stains from China in 2017. The pathological tissue was grinded and the fluid was inoculated to cell line PK-15, and the cells turned out a significant lesion in the 4 generation, and the titer reached 107 TCID50/0.1mL. The antibody neutralization test of 16 serum samples showed that the highest titer of antibody was 1:4096 in sick breed pigs. All 9 breed pigs were infected with SVA. The incidence of SVA was 66.7% and the total infection rate was 68.8%.