Infectivity and pathogenicity of wild bird-derived rotavirus A strains in domestic chickens

Rotavirus A (RVA) is one of the major agents of juvenile diarrhoea in poultry. RVA basically persists within an identical animal species, though several cases of interspecies transmission of RVA strains to birds other than their host species have been reported. However, it remains unclear whether RVA strains in wild birds, which are widely known to transmit a variety of pathogenic microorganisms to poultry, pose risks for poultry hygiene. This study investigated the infectivity and pathogenicity in poultry of the wild bird-derived RVA strains RK1 and PO-13 isolated from a duck and a pigeon, respectively. An infection experiment using a chicken model revealed that these wild bird-derived RVA strains were infectious to, and induced diarrhoea in, juvenile individuals. In addition, the faecal properties were classified into three categories (scores of 0–2), and the mean cumulative scores of each strain were compared. The cumulative scores of chickens inoculated with the RK1 and PO-13 strains (3.2 and 1.8, respectively) were comparable to those of chickens inoculated with the chicken-derived RVA strain (2.8). These results demonstrate for the first time that some of the wild bird-derived RVAs can infect poultry and possess pathogenic risks comparable to those of poultry-derived RVA. The findings of this study provide useful information to control and prevent RVA infections in the poultry industry.RESEARCH HIGHLIGHTS This study conducted an experiment on chicken infection with rotavirus A (RVA) strains.Two wild bird-derived RVA strains (RK1 and PO-13) caused diarrhoea in young chickens.The enteropathogenicity of these strains was comparable to that of a chicken strain.The findings indicate the risk of wild bird-derived RVAs in the poultry industry.