Genotypic and pathotypic characterization of Newcastle disease virus isolated from racing pigeons in China.

A Newcastle disease virus (NDV) isolated from an outbreak in racing pigeons in China was characterized in this study. Complete gene of the NDV isolate was sequenced and phylogenetic analysis. Pathogenicity experiment was carried out in pigeons, chickens, and ducks. Phylogenetic analysis revealed that the strain clustered with the Class II viruses, has highly phylogenetically similar to NDV strains isolated from pigeons in China, but was distant from the viruses prevalence in chickens and vaccine strains used in China. The deduced amino acid sequence of the cleavage site of the fusion (F) protein confirmed that the isolate contained the virulent motif (112)RRQKRF(117) at the cleavage site, but it caused no appearance disease in chickens and ducks. However, the isolate had virulence in pigeons, resulting in severe nervous signs and highly mortality. Pigeons were considered as a potential source of NDV infection and disease for commercial poultry flocks. Therefore, new vaccines to prevent the NDV infection in the pigeon flocks should be developed as soon as possible, and strict biosecurity measures should be taken to reduce the risk of pigeon Newcastle disease outbreaks.