The isolation and characterization of Duck astrovirus type-1 remerging in China.

Since the first report from Cherry Valley ducks on a commercial duck farm in China (2008), duck astrovirus type 1(DAstV-1)-associated duck viral hepatitis (DVH) have been detected in several commercial duck flocks. A highly acute disease characterized by hepatitis broke out in ducklings in Shandong Province in March 2021, all diseased ducks have been immunized against the duck viral hepatitis vaccine. One DAstV-1 strain, designated as DAstV-SDWF, was isolated from a diseased duckling. Here, the isolation, cultivation, and characterization of DAstV-1 isolate are described. The isolated astrovirus grew well in the LMH cell line. To determine the entire genomic of the DAstV-SDWF isolate, the next-generation sequencing (NGS) technique was conducted on the Illumina HiSeq platform. Complete genome sequence analysis revealed that DAstV-SDWF isolate was 91.6%-98.6% homology with others DAstV-1 deposited in Genbank. Similar clinical symptoms were successfully reproduced by an experimental infection study using the DAstV-SDWF isolate. DAstV-SDWF is the first DAstV-1 strain whose experimental infection study has been conducted in China. Results of the above data demonstrated that DAstV-1 could be one of the causative agents of the DVH occurring in China. The present works are likely to provide new insights into the pathogenicity and evolution of DAstV-1 in ducks.