Molecular Epidemiological Characteristics of Group A Rotavirus in Sika Deer in Jilin Province, China

This study focuses on epidemiological characteristics and genetic evolution of rotavirus (RV) isolated from sika deer in Jilin Province, China. The objective is to determine the positivity rate and genotypes of rotavirus circulating in diarrheic sika deer fawns. Polymerase chain reaction (PCR) targeting the rotavirus VP6 gene was utilized to detect positive samples from the collected diarrheal samples. The positive samples were subjected to genotyping by amplification of the VP4 and VP7 genes, and then phylogenetic analysis was conducted to analyze the genetic diversity of the virus. As a result, 230 samples tested positive out of 438 diarrheic samples, resulting in a positivity rate of 52.5% in diarrheic samples. The genotyping analysis showed that the genotypes G6, G10, and G8 accounted for 70.59%, 26.47%, and 2.94%, respectively; while types P[1], P[11] and P[14] occupied 42.59%, 37.03% and 20.3%, respectively. Seven genotypic combinations were identified, with G6P[1] (34%) and G6P[11] (30%) being the most dominant. The successfully isolated SY-73 (G8P[1]) strain clustered with bovine RV strains, demonstrating the genetic diversity and recombination traits of the deer-derived RV. It was shown that the isolated SY-73 (G8P[1]) strain caused diarrhea in suckling mice, confirming its pathogenicity. Histopathological analysis further revealed intestinal lesions in infected mice, including villus atrophy and epithelial damage, supporting its in vivo pathogenic effects. This study indicates a relatively high infection rate of rotavirus in sika deer in the studied regions, characterized by complex and variable genotype combinations, with the potential for cross-species transmission.