A Novel Polyomavirus (Goose Hemorrhagic Polyomavirus) Is the Agent of Hemorrhagic Nephritis Enteritis of Geese

Abstract

We have identified the etiological agent of hemorrhagic nephritis enteritis of geese (HNEG), a fatal disease of European geese. HNEG has been recognized in almost all goose breeding areas, with an epizootic pattern, and up to now, the infectious agent has remained unknown. In order to identify the causative agent, infected tissues from HNEG-affected geese were inoculated to 1-day-old goslings, which then developed clinical signs typical of HNEG. Tissue homogenates from these birds were subjected to Freon extraction followed by sucrose density gradient ultracentrifugation. The resulting main band was examined by electron microscopy and consisted of spherical, naked, papovavirus-like particles approximately 45 nm in diameter. The virus was isolated and propagated in goose kidney cell primary culture. Tissue-or culture-purified virus allowed the experimental reproduction of the disease in goslings. Random PCR amplification of viral nucleic acid produced a 1,175-bp fragment which was shown to be associated with field samples collected from geese affected by HNEG on commercial farms in France. Sequence analysis of the PCR product revealed a unique open reading frame, showing 63 to 72% amino acid similarity with the major capsid protein (VP1) of several polyomaviruses. Finally, based on phylogenetic analysis, we conclude that the causative agent of HNEG is closely related to but clearly distinct from other polyomaviruses; we thus have named this newly identified virus Goose hemorrhagic polyomavirus.

Preliminary survey of the occurrence of goose haemorrhagic polyomavirus (GHPV) in wild birds in Poland

“…All avian polyomaviruses have an additional ORF located upstream of the VP2-encoding region, which in the case of GHPV encodes protein homologous to VP4 (designated as product of ORV-X) (10). The phylogenetic analysis carried out on the basis of the VP1 gene sequence confirmed that this virus is significantly divergent from other polyomaviruses and represents a distinct virus species in the Polyomavirus genus (8).…”

“…High replication levels of GHPV in these birds have suggested that ducks may be a subclinical reservoir of the virus (17). The occurrence of the GHPV infection in other avian species seems to be very likely, because subclinical infections have been reported in migrating wild geese (8).…”

“…The purpose of this study was to evaluate the prevalence of GHPV infections in different species of wild birds in Poland due to the fact that the significance of GHPV, the second polyomavirus in wild birds, remains unclear and because GHPV infections in migrating wild geese have been reported (8). The paper presents preliminary results of the study on the prevalence of GHPV in different species of wild birds inhabiting Polish territory.…”

“…The first one, APV, was isolated from nestling budgerigars with acute fatal disease and designated as budgerigar fledgling disease virus (BFDV), but now it is called APV because of its broad host range (3,9). GHPV was identified as the aetiological agent of haemorrhagic nephritis and enteritis of geese (HNEG) in 2000 (8). In 2006, two additional polyomaviruses were detected in the wild bird populations and characterised by genome sequencing (12).…”

“…An accurate biological method for GHPV titration is inoculation of goose embryos onto the chorioallantoic membrane (CAM) (1). The detection of viral genetic material by PCR assays is a much more effective method of identification of the causative agent (8,14). PCR allows to detect DNA extracted from infected tissues with primers designed on VP1 gene, which is remarkably conserved among GHPV isolates from different countries (11,15).…”