A goose-origin velogenic Newcastle disease virus strain firstly isolated from muscovy ducks

Newcastle disease virus (NDV) is a virus that causes a huge threat to the poultry industry. Highly virulent NDV has a strong pathogenicity to chickens and can cause a 100% mortality rate. Waterfowl have a relatively strong resistance to NDV. However, in recent years, the pathogenicity of NDV to waterfowl has increased. Newcastle disease (ND) has broken out many times in duck farms and goose farms, causing huge losses. In this study, a goose-origin NDV strain, Muscovy Duck/Guangdong/JM1/2023 (JM1), was isolated from a duck farm where the laying rate had significantly decreased. This is the first strain of goose-origin NDV that broke out in muscovy ducks and was isolated. This is the strong evidence of the cross-species transmission of NDV strains. The cleavage site of the F protein of JM1 is 112/K-R-Q-K-R-F/117, the MDT is 52.8 and the ICPI is 1.73, indicating that JM1 is a velogenic strain. JM1 belongs to genotype XII.2 of class Ⅱ, and it has a low homology with traditional vaccine strains and numerous amino acid mutations in the F protein and HN protein. JM1 has pathogenicity to both chickens and ducks. It causes a 100% mortality rate in chickens and severely damages the reproductive system of muscovy ducks, resulting in a significant decline in laying rate. These results remind us that the pathogenicity of NDV towards waterfowl is increasing, and traditional commercial vaccines may not provide adequate protection. Therefore, it is necessary for us to conduct further research on the pathogenic mechanism of NDV in waterfowl, and develop effective vaccines against waterfowl NDV.