Infectious Bursal Disease Virus Antigen Research Articles

Infectious bursal disease virus structural proteins expressed in a baculovirus recombinant confer protection in chickens

Plasmids were prepared that contained cDNA segments of the large genomic segment A of infectious bursal disease virus (IBDV) strain GLS-5. The genes encoding the IBDV structural proteins (VP2, VP3 and VP4) were introduced into the baculovirus transfer vector pBlueBacI to obtain a recombinant baculovirus vIBD-7. When insect cells were infected with recombinant viruses, the result was synthesis of IBDV precursor proteins which were processed by the viral protease. The recombinant IBDV antigens were characterized by immunoprecipitation with monoclonal antibodies (MAbs) and polyclonal antiserum to IBDV, and by antigen-capture ELISA using a panel of IBDV-specific MAbs. The recombinant IBDV antigens closely resembled the native IBDV proteins and reacted with all the GLS-5 strain-specific neutralizing MAbs that recognize only conformational epitopes of IBDV. When susceptible chickens were inoculated with the recombinant IBDV antigens, virus-neutralizing antibodies were induced that conferred up to 79% protection against IBDV challenge.

The use of monoclonal antibody probes for the detection of infectious bursal disease virus antigens

Two monoclonal antibodies (MAb), 2E6 and 2G10, were used against infectious bursal disease virus (IBVD) P3009 in an immuno-dot assay to detect IBDV antigens from cell culture, and from bursa and spleen tissue samples of chickens. The limit of viral antigens detected by using both MAb probes was 48 ng. The probes were used to detect five serotype 1 IBDV isolates and one serotype 2 IBDV strain. The result indicated that these probes had broad specificity. The probes, however, did not cross-react with viral antigens prepared from seven unrelated avian viruses. The probes detected IBDV antigens in bursa and spleen tissues collected from chicks as early as 2 days after inoculation. The IBDV antigens in bursa tissue samples from six poultry farms were detected by both probes. However, tissue samples from two of six farms did not react with probe 2E6. The data suggest that it is possible to use two MAb probes for diagnosis of IBDV infection in poultry farms.

A monoclonal antibody‐based agar gel precipitin test for antigenic assessment of infectious bursal disease viruses

Five monoclonal antibodies (MAbs) directed at different neutralization epitopes of infectious bursal disease virus (IBDV) precipitated IBDV antigens in double immunodiffusion. Based on the positive or negative reaction of some of the MAbs in agar gel precipitin tests (AGPT), four different antigenic species of IBDV could be discerned. Although the antigen-capture enzyme-linked immunosorbent assays (AC-ELISA) were more sensitive than AGPTs for differentiating IBDV types, use of the MAbs in AGPT did offer a useful and accessible technique for differentiating wild type IBDV directly from infected tissues taken in the field.

Pathogenicity of an isolate of infectious bursal disease virus in local Nigerian ducks

Three to six-week old local Nigerian ducks were inoculated orally and intraocularly with an isolate of infectious bursal disease virus (IBDV) serotype 1 which was pathogenic for chickens. Neither clinical signs nor gross or microscopic lesions were observed. IBDV antigen was not detected in the bursa by the agar gel diffusion precipitation test. Precipitins and neutralising antibodies to IBDV were also not detected in the serum samples and IBDV was not isolated from the bursa, spleen and liver of the ducks. The above observations suggest that the ducks might be resistant to IBDV infection.

Note préliminaire sur la prévalence de la maladie de Gumboro chez les volailles au Cameroun

The occurrence of infectious bursal disease (IBD) in industrial poultry flocks in Cameroon was investigated by serological and virological techniques. Antibody to IBD virus was detected in 118 (33.9%) out of 348 serum samples collected in seven randomly selected areas. On the other hand, virological examination was performed on bursa of Fabricius samples obtained post-mortem from flocks in which there was a high mortality among young birds. This virological examination revealed the presence of IBD virus antigen. These observations confirm the occurrence of infectious bursal disease in Cameronian industrial poultry flocks.

Group and Strain-Specific Neutralization Sites of Infectious Bursal Disease Virus Defined with Monoclonal Antibodies

Two somatic cell hybridizations were performed utilizing splenocytes from mice immunized with one or more strains of infectious bursal disease virus (IBDV). Supernatants from hybridoma cell lines were initially screened by the enzyme-linked immunosorbent assay (ELISA) against multiple strains of IBDV. Cell lines that secreted antibodies with ELISA reactivity patterns of interest were cloned, and their monoclonal antibodies (MCAs) were subsequently tested in cross-virus-neutralization tests. Two of the nine MCAs selected exhibited strong neutralizing activity and precipitated IBDV antigens in agar gel precipitin tests as well. MCA B69 significantly neutralized only the cloned D78 strain of IBDV, whereas MCA R63 neutralized all IBDV strains (representing both serotype I and II viruses) against which it was tested. Results of competitive ELISAs that used the R63 and B69 MCAs showed that the two neutralization sites on the D78 strain were not overlapping.

Susceptibility of Laboratory Rats and Guinea-pigs to Infectious Bursal Disease Virus Infection

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Counter immunoelectroosmophoresis in the diagnosis of infectious bursal disease of poultry.

Infectious bursal disease virus antigen was detected in the bursa of Fabricius of infected birds by the use of the counter immunoelectroosmophoresis technique. Eight suspected outbreaks were confirmed in this way and 82 out of 89 bursal samples submitted for laboratory confirmation were positive. The test was also suitable for the detection of antibody to infectious bursal disease virus in sera of infected birds. Precipitin lines were visible within 30 min as compared with 18 to 24 h with the Ouchterlony agar gel precipitation test. Counter immunoelectroosmophoresis is recommended for rapid confirmation of infectious bursal disease of poultry.

牛血清中にみられる伝染性ファブリキウス嚢病ウイルスのプラーク形成に対する抑制物質の性状

Sixty-six serum samples from field cattle (field sera) and 17 samples of commercially available sera (calf and fetal bovine sera) for cell cultures were tested for inhibitory effect on the growth of infectious bursal disease virus (IBDV) by plaque assay. The average plaque reduction due to the field and calf sera was more than 90%, whereas that of the fetal bovine sera was less than 29%.The serum with high inhibitory effect did not react with IBDV antigen in the immunodiffusion test. This suggested that the effect might not be due to specific antibodies against IBDV.When the serum with inhibitory effect was fractionated by DEAE-cellulose column chromatography, it was found that the inhibitory effect was mainly associated with the IgG fraction, and relatively low in other pooled fractions. The activity was destroyed by treatment with either trypsin or ethyl ether but not with kaolin, acetone, heparin or receptor-destroying enzyme.The fluorescent antibody test showed that the serum with high inhibitory effect was attached nonspecifically to chicken embryo fibroblasts.

An Outbreak of Infectious Bursal Disease among Chickens between 16 and 20 Weeks Old

Infectious bursal disease (IBD) was diagnosed in a flock of 1,031 broilers and cockerels aged between 16 and 20 weeks. Affected birds passed whitish, watery feces. On postmortem examination, the bursa of Fabricius (bursa) was enlarged and the kidney tubules were well distended. Histopathological sections of the bursa were characterized by edema, destruction of lymphocytes, and heterophilic infiltration. Spread was rapid, and the average mortality rate was 3.5%. Bursal homogenates from dead chicks produced precipitation lines with known IBD antiserum in the agar-gel diffusion precipitation test. Sera collected from surviving chicks 10 days after the onset of the outbreak also gave precipitation lines with known IBD virus antigen. Fresh bursal homogenates from dead chicks administered intraconjunctivally to susceptible chicks exhibited typical IBD.