Bovine herpesvirus 4 isolates: a comparison of three major glycoproteins.

Twenty-four Belgian field isolates of bovine herpesvirus 4 (BHV-4), together with four reference strains were compared by radio-immunoprecipitation and western blotting using a polyvalent antiserum and monoclonal antibodies raised against major glycoproteins. Most of these strains showed the same protein profile as the European reference strain Movar 33/63. For two strains the molecular weight of gp 6, p (gp 10/gp 17) and gp 10 were the same as those of the American reference strain DN 599. No relationship could be established between the protein profiles and origin of the isolates or with the restriction patterns. This study provides a view of the molecular weight variations of the major BHV-4 glycoproteins among field isolates.     

Detection of rotavirus in faecal specimens with a monoclonal antibody enzyme-linked immunosorbent assay: Comparison with polyclonal antibody enzyme immuno-assays and a latex agglutination test

Monoclonal antibodies have been produced against the 81/36F strain of rotavirus. One of them, was chosen as diagnostic reagent: it showed high ELISA reactivity with all the bovine, human and porcine rotavirus strains tested and reacted with VP6, structural protein product known to support the common rotavirus antigen.

A sandwich ELISA procedure using the chosen monoclonal as “capture and detecting” antibody was performed to detect rotavirus in faecal samples from experimentally inoculated newborn calves: it always gave a negative response with meconium and a positive response for the stool specimens which rotavirus have been isolated. This assay was compared with Enzygnost and Slidex Rota Kit tests and with a non-commercial sandwich ELISA test using polyclonal antibodies: it showed more sensitivity than the agglutination test and was as sensitive as the other two tests to detect rotavirus in routine diagnostic material. The test evaluated showed no equivocal results.     

Molecular biology of bovine herpesvirus type 4.

Bovine herpesvirus type 4 (BHV-4) is a ubiquitous virus of cattle. Its genome is a 144 +/- 6 kb double-stranded DNA consisting of a unique central part (L-DNA) flanked at both ends by tandem repeats called polyrepetitive DNA (prDNA or H-DNA). The overall arrangement of genes has been obtained by the analysis of homologies between short BHV-4 DNA sequences and corresponding genes of Epstein-Barr virus (EBV) and herpesvirus saimiri (HVS). The gene expression is temporally regulated. Glycoprotein precursor p (gp10/gp17) is expressed as gamma 1 polypeptide. Glycoproteins gp1, gp8, gp11 and their precursors are gamma 2 proteins. The analysis of strain variations allows the definition of two types of strains, based on the DNA patterns: the Movar 33/63-like and the DN 599-like strains. Only the M40 strain, isolated in India, fails to fit this classification. The genomic variations have been compiled to build a dendrogram showing three levels of divergence between BHV-4 strains or isolates. The available molecular data indicate that the BHV-4 genome shares much similarity with the DNA of EBV and HVS, two representative members of the gammaherpesvirinae. BHV-4 may therefore be classified in the subfamily gammaherpesvirinae.     

Serological survey concerning the IBR, CHV2, BVD, PI3, BRS and rinderpest viruses in small ruminants in Zaire

More than 400 small ruminant sera from Za?re were screened for antibodies to IBR, CHV2, BVD, bovine and ovine PI3, BRS and rinderpest viruses. Sera from local animals were negative for BVD, PI3 and rinderpest viruses: 8% of sera were positive for IBR virus, all with higher titers to CHV2; 31% of sera were positive to BRS virus.     

A survey of the transmission of infectious diseases/infections between wild and domestic ungulates in Europe

ABSTRACT: The domestic animals/wildlife interface is becoming a global issue of growing interest. However, despite studies on wildlife diseases being in expansion, the epidemiological role of wild animals in the transmission of infectious diseases remains unclear most of the time. Multiple diseases affecting livestock have already been identified in wildlife, especially in wild ungulates. The first objective of this paper was to establish a list of infections already reported in European wild ungulates. For each disease/infection, three additional materials develop examples already published, specifying the epidemiological role of the species as assigned by the authors. Furthermore, risk factors associated with interactions between wild and domestic animals and regarding emerging infectious diseases are summarized. Finally, the wildlife surveillance measures implemented in different European countries are presented. New research areas are proposed in order to provide efficient tools to prevent the transmission of diseases between wild ungulates and livestock.     

A field trial in Belgium to control fox rabies by oral immunisation

Campaigns of fox vaccination against rabies were carried out in Belgium in September 1986 and June and September 1987. The SAD B19 attenuated strain of rabies virus was inserted into baits which were distributed over an area of 2100 km2 at a density of 11 baits/km2. As recommended by the World Health Organisation, the efficacy and the innocuity of the method were controlled in the field and in the laboratory. Samples of blood and brain and jaw were taken from foxes which were shot or found dead in the vaccination area, for the diagnosis of rabies, the titration of antirabies antibody and the detection of tetracycline marker. In rabid animals, the virus strain was characterised by immunofluorescence using monoclonal antibodies. In September 1987, the uptake of the baits had reached 72 per cent by 14 days after distribution. Several wild species competed with foxes in taking the baits. After the last campaign, tetracycline was found in 65 per cent of the healthy foxes collected and rabies virus neutralising antibodies were detected in 77 per cent of them. In 1987, the incidence of rabies decreased markedly in the vaccination area compared with the untreated areas. No vaccine virus was isolated either from rabid animals or from 228 small mammals trapped in the vaccination area.     

Therapy of Aujeszky's disease (pseudorabies) in naturally infected and artificially inoculated piglets using BW B759U (9-[1,3-dihydroxy-2-propoxymethyl] guanine)

Two experimental porcine models of Aujeszky's disease (AD) were compared for assessing the efficacy of potential antiviral compounds. While signs were the same following intranasal inoculation and in-contact transmission of the causal herpesvirus, SHV-1 (Suid herpesvirus), the time-course of the disease was different. There was less variation in clinical signs between pigs following artificial infection, but the disease was more severe, making this a consistent but also more stringent test system. A nucleoside analogue, BW B759U (9-[1,3-dihydroxy-2-propoxy-methyl] guanine), was administered intramuscularly in divided twice daily doses at 50 mg kg-1 to three-week-old piglets in these two SHV-1 disease models. In artificially infected animals, in which treatment was begun 1.5 hours preinfection and continued for six days, there was a delay in the onset of clinical signs (4.8 compared with 3.2 days), a 1 log10 reduction in virus shedding, and a 1 to 2 log10 reduction in virus recovered from tissues, but all the treated piglets died from AD. In contrast, none of the BW B759U-treated piglets in the in-contact model system died during the eight-day medication period, although two piglets died subsequently. Mean serum concentrations of BW B759U two hours after intramuscular dosing were about 45 microM, at nine hours 15 to 20 microM and at 17 hours 3.5 microM. The in vitro IC50 of BW B759U against SHV-1 varies from 1.5 to 80 microM depending on the cell line in which the assay is carried out. There were no overt signs of BW B759U toxicity in the treated piglets.