Immunohistochemical and molecular detection of duck enteritis virus in liver tissues of experimentally infected ducklings

Duck viral enteritis (DVE)or duck plague is an acute, sometimes chronic, contagious and lethal disease that attacks ducks, geese, swans, and other members of the family Anatidae of the order Anseriformes. Accurate diagnosis of the disease is very important for control of duck plague. In this study, findings of polymerase chain reaction (PCR) for detection of viral DNA, the histopathologicalchanges and immuno-histochemical (IHC) techniques for detection of the viral antigens in tissues, in an experimental infection of duck enteritis virus (DEV) in ducklings have been described.Histopathological examination revealed characteristic changes of vacuolar degeneration, proliferation of bile ductules and inclusion bodies in infected liver tissues. A positive IHC staining reaction indicated the presence of DEV antigens at various tissue locations mainly associated with necrotic foci in the liver.The DEV DNA was detected in the liver tissue samples of ducklings by PCR amplification of DNA polymerase and gp300 genes of DEV. Sequencing of the amplified products revealed the identity of 99%-100%, with published sequence of DNA polymerase and gp300 genes of DEVavailable in the NCBI database.These findings may be useful for a confirmatory diagnosis of duck plague during outbreaks, epidemiological investigations and also for study of pathogenesis of duck plague, in whichhistopathology, IHC techniques in conjunction with molecular tools may be recommended.