Molecular identification of novel duck associated Chapparvovirus in ducks, first report from China

Duck Associated Chapparvovirus (DaChPV) is a newly discovered virus within the Chaphamparvovirus genus, and first identified from Canadian wild ducks in 2021. In this study, DaChPV DNA was detected in 14 out of 137 tissues samples collected from diarrhea ducks across various provinces in China. Subsequently, eight complete genome sequences were amplified using overlapping primers and sequenced. Comparative analysis revealed that the amino acid (aa) sequences of NS1 and VP1 from these eight DaChPV strains shared identity with reference strains, ranging from 81.43 % to 98.81 % for NS1 and 76.95 % to 98.39 % for VP1, respectively. Phylogenetic analysis of the genome sequences showed that the newly identified DaChPVs and reference DaChPV strains formed an independent cluster, indicating a close genetic relationship. The strains of AH2301, HN2201 and HN2301 identified in this study were classified as belonging to Duck Associated Chaphamapavovirus 1. In contrast, AH2401, HN2401, and SD2301 were grouped with Duck Associated Chaphamapavovirus 2. The remaining two strains, HeB2201 and HeB2401, may represent variant strains that cluster independently, which is further supported by the evolutionary tree results of VP1 and NS1. Additionally, inter-type recombinations were predicted for these DaChPV strains. The contained multiple specific mutation sites, including 63, 76, 78, 303, and 305 that located on the predicted antigenic epitopes. This research firstly determined the evolutionary trends of DaChPV in China, offering valuable insights for understanding of spread, evolution, and molecular epidemiology of DaChPV on a global scale.