Phylogenetic and genome analysis of seven senecavirus A isolates in China.

Senecavirus A (SVA) is the only member of genus Senecavirus that causes vesicular lesions in pigs. We have characterized seven SVA isolates from different swine farms in Guangdong, China. The most variable isolate, CH-DL-01-2016, contained a single amino acid insertion at position 219-220 and a 16 amino acid insertion at position 250-251. The VP1 protein also had four nucleotide changes when compared to 31 other SVA VP1 sequences obtained from GenBank. These mutations have not been identified before. Phylogenetic trees demonstrated that the new SVA isolates were clustered into two different clades and shared 96.3%-97.1% similarity with US strains and 97.9%-98.3% similarity with Brazilian stains on nucleotide level, respectively. Prediction of antigenic epitope indicated that SVA VP1 protein contained both potential B-cell and potential T-cell epitopes. This report provides information about variation analysis in SVA in southern China.