Isolation, recombinant rescue and pathogenicity of a porcine-bovine reassortant G5P[7] group A rotavirus

Abstract Porcine rotavirus (PoRV) induces severe gastroenteritis in both suckling and weaned piglets, resulting in substantial economic losses to the global swine industry. In this study, a group A PoRV (PoRVA) strain, designated RShanD1, was isolated from the intestinal contents of a piglet suffering from severe diarrhea. Whole-genome sequencing analysis revealed that the genotype of RShanD1 is G5-P[7]-I5-C1-M1-R1-A1-N1-T1-E1-H1. Phylogenetic analysis indicated that RShanD1 is a porcine-bovine reassortant rotavirus. By cotransfecting 11 plasmids encoding viral structural and nonstructural proteins, along with a plasmid expressing the African swine fever virus (ASFV) capping enzyme NP868R, into BHK-T7 cells (baby-hamster kidney cells stably expressing T7 RNA polymerase), we established a complete reverse genetics system for RShanD1. Compared with those of the parental strain wtRShanD1, the plaque sizes and growth kinetics of the rescued virus, rRShanD1, were comparable. We also assessed the pathogenicity of rRShanD1 and wtRShanD1 using a suckling mouse infection model, and the results demonstrated that both parental wtRShanD1 and rescued rRShanD1 tended to exhibit similar changes in average daily weight, viral shedding, and intestinal histopathology. Overall, we isolated and identified a porcine–bovine reassortant rotavirus and successfully established a reverse genetics system, which not only facilitates the study of PoRV biology but also paves the way for advancing the development of PoRV vaccines.