Identification and genomic characterization of a goose astrovirus in Henan Province, China

Goose astrovirus (GAstV) is an emerging pathogen that primarily causes gout in goslings under 4 weeks of age, resulting in substantial economic losses to the goose industry in China. In this study, we isolated and identified a GAstV strain, designated GAstV/HNJZ, from infected goslings in Henan Province, China. Infected goslings exhibited typical pathological lesions: the surfaces of the heart, liver, and kidneys were covered with urate membranes, and a "villous heart" was formed due to urate deposits. The kidneys and the joints were swollen. Massive urate deposits were observed in the tarsal and toe joints. Sequence analysis revealed that the complete genome of GAstV/HNJZ isolate was 7,183 nt in length, sharing the highest nucleotide identity (99.6%) with the virulent GAstV strain AAstV/Goose/CHN/2023/HR2306/1 from Anhui Province. Phylogenetic analysis demonstrated that the GAstV/HNJZ isolate belonged to genotype GAstV-II, subgenotype IId, indicating that GAstV-II remains the predominant circulating genotype in China. Several specific amino acid mutations were identified in the N-terminal capsid core domain (H26Q, A228T, A/T289T, and N380S). Selection pressure analysis revealed that Chinese GAstV strains have evolved in a relatively conserved and stable manner. This finding provides a theoretical basis for further research on the pathogenic mechanism, targeted vaccines and antiviral drugs against goose astrovirus.