Identification and characterization of the first G8P[1] sheep rotavirus strain in China: Genetic similarity to human rotavirus and zoonotic potential.

Abstract

Rotavirus (RV) is a major cause of gastroenteritis in both humans and many mammals, including livestock. However, information regarding RV in sheep remains limited, particularly in China. This study reports the first isolation and characterization of the G8-P[1]-I2-R2-C2-M2-A11-N2-T6-E2-H3 type sheep RV strain (GS13) in China. Anal swab and small intestinal tissue samples were collected from clinically diarrheic sheep, and RV was detected via PCR and immunohistochemistry. The virus was successfully isolated using MA-104 cells, with transmission electron microscopy revealing "wheel-shaped" particles of 70-80 nm in diameter. The GS13 strain showed 98.61 %, 97.14 %, 97.09 %, and 96.76 % nucleotide similarity in the VP6, NSP1, NSP2, and NSP4 genes with human RV strains, and phylogenetic analysis placed both strains in the same branch. Pathogenicity testing in suckling mice demonstrated significant diarrhea, highlighting the potential zoonotic risk of this strain. These findings provide critical insights into the genetic identity, pathogenicity, and human infectious potential of sheep RV.