Metagenomic identification, isolation, and complete genome characterization of two novel picornaviruses in wild duck from Northeastern Siberia.

Duck hepatitis A virus (DHAV, Avihepatovirus ahepati species) is a well-known pathogen of domestic ducks, causing fatal disease in ducklings and posing a significant burden to duck poultry farms. Avihepatovirus ahepati is the sole species within the genus Avihepatovirus and is classified into three distinct genotypes: DHAV-1, DHAV-2, and DHAV-3. In our study, we detected and isolated two strains belonging to the Picornaviridae family from Anas crecca in Northeastern Asia. One of the isolates is related to the DHAV-1 group; however, its polyprotein gene sequence shares only 77.83% nucleotide identity and 89.68% amino acid identity with the most closely related DHAV-1 sequence available, suggesting it represents a highly divergent lineage. The second isolated duck picornavirus shows 60.16% nucleotide identity to the polyprotein gene sequence of the previously described duck picornavirus strain detected during an outbreak in domestic ducks in China. The identification of these two novel picornaviruses in wild ducks, along with their efficient replication in duck embryos and primary cell cultures, emphasizes the need for comprehensive studies of their prevalence in wild ducks and their biological traits to assess potential risks for wildlife and poultry farming. The obtained complete genome sequences and viral isolates enhance our understanding of the diversity, evolution, and ecology of avian picornaviruses.