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Infectious bursal disease virus*

Infectious bursal disease virus (IBDV) is an important member of the Birnaviridae family. IBUV mainly targets the bursa of Fabricius, the central immune organ of chicken, resulting in chicken infectious bursal disease (IBD). IBD represents one of the great challenges for ongoing development of the poultry industry. Reverse genetics for IBDV emerged over twenty years ago. Since then, the technologies behind virus rescue have continually improved leading to a deep understanding of IBDV gene function and tailored vaccine development. Our lab has also been instrumental in the field of IBDV research. Here we review studies on the pathogenic mechanism and the effective prevention and control of IBD.
Animals ; Birnaviridae Infections ; virology ; Chickens ; Infectious bursal disease virus ; genetics ; physiology ; Poultry Products ; virology ; Reverse Genetics

Infectious bursal disease virus (IBDV) is responsible for a highly contagious disease of poultry causing severe immunosuppression in chickens. A double antibody sandwich ELISA (DAS-ELISA) was developed to detect IBDV from clinical samples. Two kinds of anti-IBDV antibodies, monoclonal antibody R63 and chicken anti-IBDV sera, were used for DAS-ELISA. Detection limit of IBDV by DAS-ELISA was approximately 10(2.7) EID(50)/ml. The DAS-ELISA detected IBDV from most (13/14) of vaccine products including mild, intermediate and intermediate-plus types. The DAS-ELISA also detected IBDV from all (19/19) of field Korean isolates including very virulent and intermediate-plus phenotypes. Our results indicate that the DAS-ELISA would provide useful diagnostic tool to detect IBDV from clinical samples as well as rapid quantitative detection of IBDV.
Antibodies, Monoclonal ; Chickens ; Enzyme-Linked Immunosorbent Assay ; Immunosuppression ; Infectious bursal disease virus ; Limit of Detection ; Phenotype ; Poultry ; Viruses

The resistance effect on Newcastle disease virus (NDV) and Infectious Bursal Disease Virus(IBDV) in vitro of a new antimicrobial substance (AS), which produced by a Bacillus subtilis strain named B. subtilis fmbJ. Results showed that the TD50 and TD0 value of this AS on Chicken Embryo Fibroblasts cell (CEF) were 128.95mg/L and 25.79mg/L, respectively. This AS could strongly inhibit the cytopathic effects of cell induced by NDV as well as IBDV, and increase the survival rate of cell remarkably. This AS could inhibit the function of NDV and IBDV, and it could defend against the infection and inhibit multiplication of NDV and IBDV, and the effect was the same as the antiviral medicine Ribavirin. It had lower toxicity to CEF cell, therefore we would study it further that it was as antiviral medicine.
Animals ; Antiviral Agents ; metabolism ; toxicity ; Bacillus subtilis ; metabolism ; Chick Embryo ; cytology ; Fibroblasts ; cytology ; drug effects ; Infectious bursal disease virus ; drug effects ; Newcastle disease virus ; drug effects

Infectious bursal disease virus (IBDV) is a member of the Avibirnavirus genus of the Birnaviridae family which genome consists of two segments (A and B) of double stranded RNA. Segment A gene of KNU08010 isolate, which was isolated from a 15-day-old chicken flock in 2008, was sequenced and compared with other IBDV isolates including SH/92 strain, the first Korean very virulent (vv) IBDV isolate. The amino acid sequences of segment A gene showed that KNU08010 had 99.2% homology with SH92 strain. KNU08010 isolate had specific amino acids A222, I242, I256, I294 and S299 which are highly conserved among vvIBDV strains. Phylogenetic analysis based on the nucleotide sequences of variable region of the VP2 gene of 18 IBDV strains revealed that KNU08010 was grouped with vvIBDVs and was closely related to Korean vvIBDVs isolated from wild birds.
Amino Acid Sequence ; Amino Acids ; Avibirnavirus ; Base Sequence ; Birds ; Birnaviridae ; Chickens ; Genes, vif ; Genome ; Humans ; Infectious bursal disease virus ; Korea ; RNA, Double-Stranded ; Sequence Analysis ; Sprains and Strains

Infectious bursal disease virus (IBDV) causes a highly contagious and immunosuppressive disease of chicken. Agar gel immunodiffusion using IBDV antigen extracted from bursa of Fabricius of infected chicken has been used officially for diagnosis of IBDV in Korea. In this study, in order to replace the IBDV whole virus antigen with non-infectious antigen, recombinant VP2 protein (rVP2) of IBDV was produced using recombinant baculovirus expression system. Purified baculovirus-expressed rVP2 was used as an antigen in an agar gel immunodiffusion (AGID). rVP2 antigen precipitated specifically IBDV antibodies. AGID using rVP2 antigen detected anti-IBDV antibodies from 6 dpi to 28 dpi (termination of the experiment) when specific pathogen free chickens were experimentally infected with IBDV 52/70 strain. This was consistent with result by AGID using IBDV antigen, virus neutralization test (VNT) and a commercial ELISA kit (except for one serum). The sensitivity of rVP2 was the same with that of IBDV antigen when field sera (n=324) were tested by AGID. However, AGID using rVP2 antigen detected maternal antibodies from broiler chickens (n=20) on a broiler farm up to 15 days old, although the detection rate of the AGID was relatively low compared to a commercial ELISA kit. Our results indicate that IBDV whole virus antigen from IBDV infected chickens would be replaced with recombinant VP2 protein as an antigen for AGID.
Agar ; Animals ; Antibodies ; Baculoviridae ; Bursa of Fabricius ; Chickens ; Enzyme-Linked Immunosorbent Assay ; Immunodiffusion ; Infectious bursal disease virus ; Korea ; Neutralization Tests ; Specific Pathogen-Free Organisms ; Sprains and Strains ; Staphylococcal Protein A ; Viruses

Two Bangladeshi infectious bursal disease virus (IBDV) isolates collected in 2007, termed GB1 and GB3, were subjected to comparative sequencing and phylogenetic analyses. Sequence analysis of a 474-bp hypervariable region in the VP2 gene revealed that among four major amino acid substitutions observed in the strains, two were unique to GB1 and GB3 (Ser217Leu and Ala270Thr) while one substitution was only found in GB1 (Asn299Ser). Among IBDVs from Bangladesh including GB1 and GB3, the rate of identity and homology was around 97~99%. The amino acid sequences of GB1 and GB3 differ from those of previous Bangladeshi IBDV isolates and contain amino acid substitutions Pro222Ala and Asn299Ser (in GB3 only). Phylogenetic analysis revealed that GB1 and GB3 are grouped with other very virulent IBDVs of European and American origin in contrast to two previously isolated Bangladeshi IBDV strains (GenBank accession Nos. AF362776 and AF260317), which belong to the Asian group. It was concluded that GB1 and GB3 belong to a very virulent group of IBDVs. However, amino acid sequences of GB1 and GB3 differ from those of the other Bangladeshi IBDVs by one or two amino acids encoded in the hypervariable region of the VP2 gene.
Amino Acid Sequence ; Amino Acid Substitution ; Amino Acids ; Asian Continental Ancestry Group ; Bangladesh ; Chickens ; Genetic Markers ; Humans ; Infectious bursal disease virus ; Sequence Analysis

Infectious bursal disease virus (IBDV) VP4 plays an important role in immunosuppression of host. In order to develop monoclonal antibodies (McAbs) against VP4, we vaccinated BALB/c mice with His-VP4, screened and subcloned positive clones. We established 4 hybridoma cell lines that stably secreted McAbs against VP4 and named these cell lines 3B3, 3H11, 4C8 and 4G6, respectively. We tested the dissociation constant (Kd) of these McAbs, and found that their K(d)s were 4.61 x 10(-11), 1.71 x 10(-10), 4.26 x 10(-11), 5.02 x 10(-11), respectively. The isotypes of these McAbs were determined to be IgG1, IgG1, IgG2b and IgG1. These McAbs specifically bound to VP4 in IBDV infected DF-1 cells as demonstrated by Western blotting analysis and fluorescence antibody assay. These McAbs would help to detect IBDV infection and to analyze the biological activities of IBDV VP4.
Animals ; Antibodies, Monoclonal ; biosynthesis ; Blotting, Western ; Cell Line ; Fluorescent Antibody Technique ; Hybridomas ; Infectious bursal disease virus ; Mice ; Mice, Inbred BALB C ; Viral Structural Proteins ; immunology

Infectious bursal disease virus (IBDV) was inactivated by two different chemicals--formaldehyde and binary ethylenimine (BEI). Formaldehyde was used at 0.1% and 0.2%, while BEI was used at concentrations of 0.001 and 0.002 mol/L. These four vaccines were tested for their efficiency in generating humoral immune response in different groups of broiler chicks. Both BEI-inactivated vaccines gave relatively higher antibody titers and were almost twice as efficient as formaldehyde-inactivated ones.
Animals ; Antibodies, Viral ; blood ; Aziridines ; pharmacology ; Chickens ; Formaldehyde ; pharmacology ; Infectious bursal disease virus ; immunology ; Vaccination ; Vaccines, Inactivated ; immunology ; Viral Vaccines ; immunology

To meet the needs of detection of infectious bursal disease virus (IBDV) under high efficient culture, a SYBR Green I real-time RT-PCR (qRT-PCR) was developed using a pair of primers specific to the conserved region of VP4 gene of IBDV and compared with TCID50 method by monitoring the proliferation dynamics of IBDV in DF-1 cell line adherent to micro carrier in tubular reactor. The results showed that the RT-PCRassay was linear in the range of 4. 03 X 10(1)-10(9) copies/microL. The IBDV RNA detection limit was 40 copies/microL, which was 1 000 times more sensitive than conventional PCR. No cross-reactions with other viruses was observed. The intra-assay coefficient of variation was less than 0.05%. There was a parallel correlation of IBDV proliferation dynamics in DF-1 cell under Micro carrier suspension and static adherent culture by the qRT-PCR assay and TCID50 method. The detection results of the IBDV samples from tubular and flask culture showed the differences of the micro carrier and adherent culture by both methods. In conclusion, the qRT-PCR assay is more rapid and sensitive than the TCID50 method, which is more appropriate for the real time detection of IBDV.
Animals ; Calibration ; Cell Line ; Conserved Sequence ; DNA Primers ; genetics ; Infectious bursal disease virus ; genetics ; isolation & purification ; Organic Chemicals ; chemistry ; metabolism ; Real-Time Polymerase Chain Reaction ; methods ; Reproducibility of Results ; Spectrometry, Fluorescence ; Viral Proteins ; genetics ; Virus Replication