Dieter Liebhart

1. IntroductionThe Newcastle disease virus (NDV), a member of the Paramyxoviridae family, poses a global threat to poultry and wild birds due to its worldwide distribution and ability to infect various avian species [1]. Infection of birds with highly virulent strains of NDV results in immunosuppression, which at least in part results from profound depletion of lymphoid tissues [2,3].NDV has also ...

Escherichia coli resides as a gut commensal in healthy chickens but also causes the extraintestinal disease called colibacillosis. Pathotype definition is primarily based on the clinical condition of the host, but it is still not definite due to the lack of genetic traits to differentiate between commensal and harmful isolates, which has led to divided views with regard to the pathogenicity of E. ...