European Brown Hare Syndrome Virus Research Articles

Microheterogeneity of p60 capsid protein and the encoding gene among contemporary isolates of rabbit hemorrhagic disease virus.

The gene encoding the p60 capsid protein from a Spanish isolate of the rabbit hemorrhagic disease virus (RHDV) has been cloned and sequenced. Both cDNA and the derived protein sequences have been compared with those from several contemporary European RHDV isolates. Genetic heterogeneity among co-circulating viruses is nearly constant along the p60-encoding gene, around 0.034 substitutions per nucleotide, and it does not allow prediction of the preferential regions for long-term fixation of mutations. However, sequence comparisons with the more distant, but phylogenetically closely related calicivirus, the European brown hare syndrome virus (EBHSV), reveal a great extent of genetic variability within both a segment of p60 gene (nucleotides 900-1300) and the encoded polypeptide, suggesting the existence of strong selective pressures acting over this region of the capsid protein.

Antigenicity of the rabbit hemorrhagic disease virus studied by its reactivity with monoclonal antibodies

A panel of anti-rabbit hemorrhagic disease virus (anti-RHDV) monoclonal antibodies was produced and characterized. The ability of the MAbs to recognize epitopes present on RHDV capsids, European brown hare syndrome virus capsids and RHDV subunits was determined. Preliminary results on the neutralizing capacity of the MAbs were obtained by in vivo protection experiments. The antigenic map of RHDV obtained by this study is consistent with the current models of the calicivirus structure.

European brown hare syndrome virus: relationship to rabbit hemorrhagic disease virus and other caliciviruses.

Monoclonal antibodies directed against the capsid protein of rabbit hemorrhagic disease virus (RHDV) were used to identify field cases of European brown hare syndrome (EBHS) and to distinguish between RHDV and the virus responsible for EBHS. Western blot (immunoblot) analysis of liver extract of an EBHS virus (EBHSV)-infected hare revealed a single major capsid protein species of approximately 60 kDa that shared epitopes with the capsid protein of RHDV. RNA isolated from the liver of an EBHSV-infected hare contained two viral RNA species of 7.5 and 2.2 kb that comigrated with the genomic and subgenomic RNAs of RHDV and were recognized by labeled RHDV cDNA in Northern (RNA) hybridizations. The nucleotide sequence of the 3' 2.8 kb of the EBHSV genome was determined from four overlapping cDNA clones. Sequence analysis revealed an open reading frame that contains part of the putative RNA polymerase gene and the complete capsid protein gene. This particular genome organization is shared by RHDV but not by other known caliciviruses. The deduced amino acid sequence of the capsid protein of EBHSV was compared with the capsid protein sequences of RDDV and other caliciviruses. The amino acid sequence comparisons revealed that EBHSV is closely related to RHDV and distantly related to other caliciviruses. On the basis of their genome organization, it is suggested that caliciviruses be divided into three groups.

Clinical evolution and diagnosis of an outbreak of European brown hare syndrome in hares reared in captivity.

The authors studied an outbreak of an acute form of European brown hare syndrome (EBHS) in captive hares. The farm involved had shown negative results in a previous serological test for EBHS conducted on approximately 8% of the animals. Hares which succumbed during the outbreak were submitted to an anatomo-pathological examination and the livers of these animals were collected for laboratory analysis. Examination by immunoelectron microscopy and enzyme-linked immunosorbent assay confirmed the diagnosis of EBHS virus (EBHSV). An initial serological survey conducted on the survivors twenty-two days after the outbreak demonstrated an immunological response against EBHSV. During the outbreak, data were collected on morbidity, mortality, incidence of the disease in various age groups, and also on the antigenic characteristics of the virus responsible for the outbreak.

European brown hare syndrome and associated virus particles in the UK.

European brown hare syndrome and associated virus particles in the UK.