Chicken Astrovirus (CAstV) Molecular Studies Reveal Evidence of Multiple Past Recombination Events in Sequences Originated from Clinical Samples of White Chick Syndrome (WCS) in Western Canada

In this study, we aimed to molecularly characterize 14 whole genome sequences of chicken astrovirus (CAstV) isolated from samples obtained from white chick syndrome (WCS) outbreaks in Western Canada during the period of 2014–2019. Genome sequence comparisons showed all these sequences correspond to the novel Biv group from which no confirmed representatives were published in GenBank. Molecular recombination analyses using recombination detection software (i.e., RDP5 and SimPlot) and phylogenetic analyses suggest multiple past recombination events in open reading frame (ORF)1a, ORF1b, and ORF2. Our findings suggest that recombination events and the accumulation of point mutations may have contributed to the substantial genetic variation observed in CAstV and evidenced by the current seven antigenic sub-clusters hitherto described. This is the first paper that describes recombination events in CAstV following analysis of complete CAstV sequences originated in Canada.