A novel herpesvirus in three species of pheasants: Mountain peacock pheasant (Polyplectron inopinatum) Malayan peacock pheasant (Polyplectron malacense) and Congo peafowl (Afropavo congensis)

摘要

The mountain peacock pheasant (Polyplectron inopinatum), the Malayan peacock pheasant (Polyplectron malacense), and the Congo peafowl (Afropavo congensis), are all listed as vulnerable to extinction under the International Union for Conservation of Nature (IUCN) Red List of Threatened Species. Here we report fatal infection with a novel herpesvirus in all three species of birds. DNA was extracted from the livers of birds with hepatocellular necrosis and intranuclear eosinophilic inclusions consistent with herpesvirus infection. Using degenerate herpesvirus primers and polymerase chain reaction, 220 and 519 base pair products of the herpes DNA polymerase and DNA terminase genes, respectively, were amplified. Sequence analysis revealed that all birds were likely infected with the same virus. At the nucleotide level the pheasant herpes virus had 92% identity with Gallid herpesvirus 3 (GaHV-3) and 77.7% identity with Gallid herpesvirus 2 (GaHV-2). At the amino acid level the herpes virus had 93.8% identity with GaHV-3 and 89.4% identity with GaHV-2. These findings indicate that the closest relative to this novel herpesvirus is GaHV-3, a non-pathogenic virus used widely in a vaccine against Marek’s disease. In situ hybridization using probes specific to the peacock pheasant herpesvirus DNA polymerase revealed strong intranuclear staining in the necrotic liver lesions of an infected Malayan peacock pheasant, but no staining in normal liver from an uninfected bird. The Phasianid herpesvirus reported here is a novel member of the genus Mardivirus of the subfamily alphaherpesvirinae, and is distinct from other galliform herpesviruses.