Publications
| Title | Abstract | Year Filter | PMID(sorted ascending) Filter |
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| isolation and characterization of an antigenically distinct 68-kd protein from nonviral intracytoplasmic inclusions in boa constrictors chronically infected with the inclusion body disease virus (ibdv: retroviridae). | the relationship between a retroviral infection and the development of nonviral intracytoplasmic inclusion bodies was studied in a boa constrictor model. twelve juvenile age- and size-matched inclusion body disease (ibd)-negative boas were randomly divided into three groups. each group was inoculated intraperitoneally with 1 ml of an ibd virus (ibdv)-infected liver homogenate or 1 ml of normal boa liver homogenate (sham-inoculated control) or was left untreated. all boas were monitored for devel ... | 2000 | 11055868 |
| vp5, the nonstructural polypeptide of infectious bursal disease virus, accumulates within the host plasma membrane and induces cell lysis. | infectious bursal disease virus (ibdv) encodes a 17-kda nonstructural polypeptide known as vp5. this polypeptide is not essential for virus replication in vitro but it plays an important role in in vivo dissemination and pathogenesis. we have characterized the expression of vp5 in three eukaryotic systems: (i) ibdv-infected chicken embryo fibroblasts; (ii) bsc-1 cells infected with a recombinant vaccinia virus vector; and (iii) cos-1 cells transiently transfected with a plasmid vector. immunoflu ... | 2000 | 11080482 |
| antigen quantification as in vitro alternative for potency testing of inactivated viral poultry vaccines. | routine batch control of licensed inactivated viral vaccines for poultry usually includes a potency assay as a measure of vaccine efficacy. potency assays often consist of vaccination-challenge experiments in the target species or in laboratory animals. instead of measuring the protection of vaccinated animals against virulent pathogens, the serological response after vaccination can be quantified for some vaccines. in vitro antigen quantification assays would be attractive alternatives for the ... | 2000 | 11087135 |
| different architectures in the assembly of infectious bursal disease virus capsid proteins expressed in insect cells. | infectious bursal disease virus (ibdv) capsid is formed by the processing of a large polyprotein and subsequent assembly of vpx/vp2 and vp3. to learn more about the processing of the polyprotein and factors affecting the correct assembly of the viral capsid in vitro, different constructs were made using two baculovirus transfer vectors, pfastbac and pacym1. surprisingly, the expression of the capsid proteins gave rise to different types of particles in each system, as observed by electron micros ... | 2000 | 11118356 |
| vp5 and the n terminus of vp2 are not responsible for the different pathotype of serotype i and ii infectious bursal disease virus. | two serotypes have been identified in infectious bursal disease virus (ibdv), a member of the family birnaviridae: a reverse genetics system was used for generation of chimeras in genome segment a of the two serotypes, in which the complete viral vp5 gene and 3' noncoding region (ncr), or parts thereof, were exchanged. the engineered viruses were characterized in vitro and in vivo in comparison to serotype i and ii ibdv. our results show that ibdv chimeras exhibit a different phenotype in cell c ... | 2001 | 11125169 |
| immune responses to intermediate strain ibd vaccine at different levels of maternal antibody in broiler chickens. | 2000 | 11147275 | |
| [proliferation of attenuated infections bursal disease virus(ibdv) on vero cell on large scale]. | vero cell was selected as productive carrier in production of attenuated ibdv. the optimal conditions in culturing ibdv in agitating bottle were figured out. after proliferation, supernatant was harvested in batch process under the condition of five-liter-agitated fermenter. the result shows it was successful to culture ibdv by this methodology. | 2000 | 11191776 |
| serological monitoring on layer farms with specific pathogen-free chickens. | to monitor the existence of avian pathogens in laying chicken flocks, specific pathogen-free (spf) chickens were introduced into two layer farms and reared with laying hens for 12 months. spf chickens were bled several times after their introduction and examined for their sero-conversion to avian pathogens. as a result, antibodies to eight or ten kinds of pathogens were detected in spf chickens on each farm. antibodies to infectious bronchitis virus (ibv), avian nephritis virus, mycoplasma galli ... | 2000 | 11193353 |
| [workshop: immunosuppression in chickens]. | 2001 | 11194506 | |
| antibody titers to infectious bursal disease virus in broiler chicks after vaccination at one day of age with infectious bursal disease virus and marek's disease virus. | the effect of day-of-age vaccination with infectious bursal disease virus (ibdv) alone or in combination with marek's disease virus (mdv) in broiler chicks was investigated. one-day-old commercial broiler progeny obtained from ibdv-immunized breeder flocks were vaccinated subcutaneously according to the manufacturer's directions with live-attenuated commercially available vaccines as follows: ibdv alone, mdv alone, ibdv + mdv, and unvaccinated control. ibdv was not detected after vaccination by ... | 2000 | 11195642 |
| serologic survey of slaughter-age ostriches (struthio camelus) for antibodies to selected avian pathogens. | serum samples from 163 slaughter-age ostriches (struthio camelus) in ohio and indiana were tested for antibodies to avian influenza virus (aiv), newcastle disease virus (ndv), paramyxovirus (pmv) 2, pmv3, pmv7, infectious bursal disease virus (ibdv), bordetella avium, mycoplasma synoviae, mycoplasma gallisepticum, ornithobacterium rhinotracheale, salmonella pullorum, salmonella gallinarum, and salmonella typhimurium. one ostrich had antibodies to aiv h5n9, 57% of the ostriches had antibodies to ... | 2000 | 11195659 |
| immune responses to marek's disease virus infection. | 2001 | 11217429 | |
| development of probes for differentiation of infectious bursal disease virus strains of various virulence by dot-blot hybridization. | two different radio-labeled nucleic acid probes, prepared from reverse transcription-polymerase chain reaction (rt-pcr) amplified variable region of vp2 and vp1 gene sequences of a highly virulent infectious bursal disease virus (ibdv), were tested for their ability to detect field isolates of ibdv directly in clinical bursal tissue specimens and vaccine strains of ibdv in tissue cultures. the vp2 gene probe was able to detect both field isolates and vaccine strains of ibdv under high as well as ... | 2000 | 11252670 |
| isolation of monoclonal antibodies that inhibit the binding of infectious bursal disease virus to lscc-bk3 cells. | three hybridoma cell lines producing monoclonal antibodies (mabs) against lscc-bk3 cells which are susceptible to infectious bursal disease virus (ibdv) infection were produced and characterized. the mabs, designated t7, q11 and q13, inhibited the attachment of ibdv to lscc-bk3 cells. furthermore, these mabs bound to lscc-bk3 but not to nonpermissive cells in flow cytometry. mab t7 detected a 110-kda membrane protein of lscc-bk3 cells, whereas q11 and q13 reacted with membrane proteins of molecu ... | 2001 | 11258465 |
| detection of cell membrane proteins that interact with virulent infectious bursal disease virus. | to detect the molecules that interact with infectious bursal disease virus (ibdv), the chicken b lymphoblastoid cell line, lscc-bk3, which is permissive for virulent ibdv infection was investigated. the sodium dodecyl sulfate-solubilized plasma membrane fraction from the cells was subjected to a virus overlay protein binding assay. the ibdv specifically bound to proteins in lscc-bk3 plasma membranes with molecular weights of 70, 82 and 110 kda. this is the first report to demonstrate cellular mo ... | 2001 | 11258466 |
| apoptosis is induced by infectious bursal disease virus replication in productively infected cells as well as in antigen-negative cells in their vicinity. | the kinetics of infectious bursal disease virus (ibdv) replication and induction of apoptosis were investigated in vitro and in vivo. after infection of chicken embryo (ce) cells with ibdv strain cu-1, the proportion of apoptotic cells increased from 5.8% at 4 h post-infection (p.i.) to 64.5% at 48 h p.i. the proportion of apoptotic cells correlated with ibdv replication. uv-inactivated ibdv particles did not induce apoptosis. double labelling revealed that, early after infection, the majority o ... | 2001 | 11297685 |
| recombinant semliki forest virus vector exhibits potential for avian virus vaccine development. | the semliki forest virus (sfv) expression system was evaluated as a basis for avian vaccine development. initial studies indicated that 1-day-old specific pathogen-free (spf) chicks were susceptible to infection with an infectious strain of sfv, producing sfv-specific antibodies but no clinical disease. one-day-old spf chicks immunised intramuscularly with recombinant replication-defective sfv (rsfv) particles expressing the escherichia coli (e. coli) lacz reporter gene developed high titres of ... | 2001 | 11312006 |
| separation of pure and immunoreactive virus-like particles using gel filtration chromatography following immobilized metal ion affinity chromatography. | a purification process was developed to obtain highly pure rvp2h particles, formed by a structural protein (vp2) of the infectious bursal disease virus (ibdv) with six additional histidine residues at its c-terminus. the ultimate goal was the development of an efficient subunit vaccine against ibdv infection. the particles within the infected high-five (hi-5) cell lysates were partially purified by employing immobilized metal ion (ni(2+)) affinity chromatography (imac). the initial step could re ... | 2001 | 11312710 |
| genetic stability of the vp2 hypervariable region of four infectious bursal disease virus isolates after serial passage in specific-pathogen-free chicken embryos. | infectious bursal disease virus strains u2, 586, l1, and q2 were isolated from pooled bursal samples collected from commercially reared broilers. these viruses were propagated in specific-pathogen-free (spf) embryonated chicken eggs for 24 or 25 passages. nucleotide sequences of a 743-bp reverse transcription (rt)/polymerase chain reaction (pcr) product containing the vp2 hypervariable region were compared before and after passage of the viruses in embryonated chicken eggs. to determine the gene ... | 2001 | 11332470 |
| safety and efficacy of in ovo administration of infectious bursal disease viral vaccines. | in ovo vaccination against marek's disease virus and infectious bursal disease virus (ibdv) in commercial broilers in the united states is common. little information exists as to the safety and efficacy of intermediate ibdv vaccines given in ovo. experiments were initiated to determine the safety and efficacy of three commercially available live intermediate ibdv vaccines by in ovo route. commonly used vaccines were given at 18 days of embryonation to specific-pathogen-free (spf) broiler embryos ... | 2001 | 11332475 |
| molecular typing of infectious bursal disease virus of israeli field and vaccine strains by the reverse transcription/polymerase chain reaction/restriction fragment length polymorphism assay. | infectious bursal disease viruses (ibdvs) were examined by testing bursa samples from 37 commercially reared chicken flocks and three vaccine strains by the reverse transcription (rt)/polymerase chain reaction (pcr)/restriction fragment length polymorphism assay (rflp). the assay was conducted with a 717-bp fragment of the vp2 gene with the restriction enzymes bstni and mboi. the presence of a restriction site for sspi was used to predict a very virulent phenotype. results indicated the existenc ... | 2001 | 11332486 |
| detection of infectious bursal disease virus in experimentally infected chickens by in situ hybridization. | in situ hybridization was used in a pathogenesis study of three vaccine pathotypes (delaware variant a, d78, and bursavac) of infectious bursal disease virus (ibdv). tissues were excised (bursa, thymus, spleen, proventriculus, and cecal tonsils), fixed in formalin, and paraffin embedded at 12, 24, 48, 72, and 120 hr postinoculation (hpi). with an antisense vp2 gene probe, viral nucleic acid was detected in bursas from both d78- and bursavac-infected chickens at 24, 48, 72, and 120 hpi. however, ... | 2001 | 11332493 |
| the exacerbating effect of infectious bronchitis virus infection on the infectious bursal disease virus-induced suppression of opsonization by escherichia coil antibody in chickens. | chickens infected with infectious bronchitis virus (ibv) and infectious bursal disease virus (ibdv) commonly develop secondary infection of the respiratory tract with escherichia coli, resulting in significant economic losses. to understand the host factors that may contribute to the e. coli infection, we investigated macrophage-mediated e. coli phagocytosis, intracellular bacterial killing, and development of opsonizing antibody in previously uninfected chickens and in those infected with ibv, ... | 2001 | 11332499 |
| immunogenicity and antigenicity of very virulent strains of infectious bursal disease viruses. | the immunogenicity and antigenicity of three very virulent (vv) strains of infectious bursal disease viruses (ibdvs) from turkey (oa), holland (hol), and taiwan (pt) were investigated, and their antigenic relationships with the american classic sal, variant in serotype 1, and serotype 2 oh ibdvs were studied. in the present study, the vvibdvs were passaged eight times in chicken embryos and were characterized by reverse transcription/polymerase chain reaction-restriction fragment length polymorp ... | 2001 | 11332505 |
| construction of avian adenovirus celo recombinants in cosmids. | the avian adenovirus celo is a promising vector for gene transfer applications. in order to study this potentiality, we developed an improved method for construction of adenovirus vectors in cosmids that was used to engineer the celo genome. for all the recombinant viruses constructed by this method, the ability to produce infectious particles and the stability of the genome were evaluated in a chicken hepatocarcinoma cell line (lmh cell line). our aim was to develop a replication-competent vect ... | 2001 | 11333910 |
| selection of an infectious bursal disease virus mutant with increased immunogenicity following passage under humoral immune pressure. | it is generally known that the pathogenicity of infectious bursal disease virus (ibdv) strains decreases following passage in cell culture. however, there is no information about the effect of passage under immune pressure on the phenotypic and molecular properties of ibdv. in the present study, a small plaque mutant virus with poor neutralization capability, but showing similar growth characteristics as the parental virus strain, qc2, was isolated after serial passage in vero cells in presence ... | 2001 | 11346261 |
| molecular characterisation of very virulent infectious bursal disease viruses in taiwan. | the very virulent infectious bursal disease virus (vv ibdv) rna in the bursa of fabricius and spleen from experimentally infected chickens or field samples was detected by in situ hybridisation (ish) with subsequent reverse transcription (rt)-polymerase chain reaction (pcr) and sequence analysis. the vp 2 gene of vv ibdv was detected by ish in infected chicken tissues with a cloned digoxigenin (dig)-labelled cdna probe. to verify ish, rt - pcr was used to amplify two 643- and 500-base pair fragm ... | 2001 | 11356093 |
| functional restoration of the bursa of fabricius following in ovo infectious bursal disease vaccination. | the primary role of the avian bursa of fabricius is to provide an essential microenvironment for b-lymphocytes to diversify their immunoglobulin genes by gene hyperconversion. infectious bursal disease (ibd) vaccination using intermediate plus vaccine strains can temporarily deplete the bursal follicles and interrupt the normal b-cell development, which is generally followed by b-cell repopulation and histological regeneration. to find evidence that functional restoration of the bursa of fabrici ... | 2001 | 11389958 |
| molecular and antigenic characterization of bangladeshi isolates of infectious bursal disease virus demonstrate their similarities with recent european, asian and african very virulent strains. | three isolates of infectious bursal disease virus (ibdv), obtained from chickens in bangladesh in 1999 and designated as bd 1/99, bd 2/99 and bd 3/99, were characterized. in an antigen capture enzyme-linked immunosorbent assay using a panel of vp2-specific neutralizing monoclonal antibodies (mab), all three isolates showed a mab-binding profile similar to that of very virulent ibdv (vvibdv) strains. in contrast to the classical virulent strains, they did not react with mab 3 and mab 4. molecular ... | 2001 | 11393817 |
| pathological and immunological study of an in ovo complex vaccine against infectious bursal disease. | the appearance of very virulent strains of infectious bursal disease (ibd) virus at the end of the 1980s made it necessary to develop more effective immunization procedures. to facilitate this, the immunogenicity and the immunosuppressive effect of a mild (g-87), an intermediate (libd) and an intermediate-plus (ibdv 2512) ibdv strain were tested after the in ovo inoculation of 18-day-old spf and broiler chicken embryos. it was established that no noteworthy difference existed between the immuniz ... | 2000 | 11402661 |
| immunostimulatory effects of the muramyl dipeptide analogue lk415 in chickens immunized with a vaccine strain of infectious bursal disease virus. | the effects of muramyl dipeptide (mdp) synthetic analogue lk415 on the immune response of chickens immunized with a live vaccine against infectious bursal disease (ibd) were studied in two independent trials, using levamisole hydrochloride as comparative immunostimulant. groups of five-week-old commercial chickens (isa brown) were immunized orally with 10 doses of the vaccine strain of ibdv (winterfield strain). the chickens were then given four injections of the mdp analogue lk415 in a dosage o ... | 2000 | 11402707 |
| induction of apoptosis in vitro by the 17-kda nonstructural protein of infectious bursal disease virus: possible role in viral pathogenesis. | infectious bursal disease virus (ibdv) causes severe immunodeficiency in young chickens by destroying the precursors of antibody-producing b cells in the bursa of fabricius. it has been shown that ibdv infection induces apoptosis in chicken embryo and tissue culture cells. we previously reported that an ibdv mutant lacking the expression of 17-kda nonstructural (ns) protein exhibited decreased apoptotic effects in cell culture as compared to the parental ibdv, suggesting that the ns protein may ... | 2001 | 11414805 |
| molecular characterization of brazilian infectious bursal disease viruses. | a reverse transcriptase-polymerase chain reaction (rt-pcr) procedure was used to amplify a vp2 gene fragment (248 bp) from infectious bursal disease virus (ibdv). the procedure allowed the detection of known ibdv strains from the united states, along with field isolates and commercial vaccines produced in brazil. amplified vp2 fragments were further characterized by restriction fragment length polymorphism (rflp) analysis. from 55 brazilian commercial flocks, 48 field samples were ibdv positive ... | 2001 | 11417808 |
| amino acid comparison of infectious bursal disease viruses placed in the same or different molecular groups by rt/pcr-rflp. | infectious bursal disease virus (ibdv) strains have been identified and placed into molecular groups by a reverse transcriptase (rt)/polymerase chain reaction (pcr)-restriction fragment length polymorphism (rflp) assay. the predicted amino acid sequences corresponding to the region of the genome examined by rflp were determined and compared for 14 ibdv strains from different molecular groups and 11 ibdv strains that were identified in molecular group 6. among the viruses within molecular group 6 ... | 2001 | 11417812 |
| the in vivo and in vitro effects of chicken interferon alpha on infectious bursal disease virus and newcastle disease virus infection. | the in vitro and in vivo effects of chicken interferon alpha on infectious bursal disease virus (ibdv) infection were investigated in this study. a cdna of interferon alpha was first cloned from a chinese strain chicken shiqi by reverse transcription-polymerase chain reaction. the deduced amino acid sequence has one amino acid substitution with chicken interferon alpha 1 at residue 65 (n to s) and two amino acid substitutions with chicken interferon alpha 2 at residues 50 (n to s) and 58 (p to l ... | 2001 | 11417818 |
| in situ localization of infectious bursal disease virus-binding cells by a biotin-streptavidin system. | a biotin-streptavidin system was established to directly visualize infectious bursal disease virus (ibdv)-binding cells in cell culture or in fresh tissues. the cells or tissue sections were first incubated with a biotinylated, purified ibdv strain gz911 and then with a streptavidin-beta-galactosidase conjugate. in the presence of the enzyme substrate x-gal, ibdv-binding cells were labeled in blue color. by applying this method to frozen tissue sections, virus-binding sites were localized in sit ... | 2001 | 11417836 |
| one-step rt-pcr for the detection of infectious bursal disease virus in clinical samples. | a single-tube, non-interrupted, one-step rt-pcr has been standardized to amplify the hypervariable region of the vp2 gene sequence of infectious bursal disease virus (ibdv). the technique standardized on purified viral rna was successfully applied to the detection of the virus directly in clinical samples. the amplified products were confirmed to be ibdv specific by their size in ethidium bromide-stained agarose gel, nested pcr and restriction enzyme digestion. digestion of the amplicons with st ... | 2001 | 11469514 |
| immune response and resistance to infectious bursal disease virus of chicken lines selected for high or low antibody response to escherichia coli. | two experimental broiler lines were developed by divergent selection for high (hh) and low (ll) antibody response to escherichia coli. antibody response of these lines to immunization with a commercial vaccine (whole inactivated virus, wiv) against infectious bursal disease virus (ibdv) or with proteins vp2 and vp3 of that virus, and their resistance to challenge with a virulent ibdv, were tested. the study was performed with 213 male and female chicks from the tenth generation of the hh and ll ... | 2001 | 11469649 |
| comparison of rna and cdna transfection methods for rescue of infectious bursal disease virus. | specific alterations in the genetic material of rna viruses rely on a technique known as reverse genetics. transfection of cells with the altered generic material is a critical step of this procedure. in this report we have compared rna and cdna transfection methods for the efficiency of transient protein expression and rescue of (recombinant) infectious bursal disease virus (ibdv). quantitative expression analysis of the secreted alkaline phosphatase reporter protein, and qualitative expression ... | 2001 | 11483218 |
| effect of moi ratio on the composition and yield of chimeric infectious bursal disease virus-like particles by baculovirus co-infection: deterministic predictions and experimental results. | virus-like particles (vlps) are empty particles consisting of virus capsid proteins that closely resemble native virus but are devoid of the native viral nucleic acids and therefore have attracted significant attention as noninfectious vaccines. a recombinant baculovirus, vibd-7, which encodes the structural proteins (vp2, vp3, and vp4) of infectious bursal disease virus (ibdv), produces native ibd vlps in infected spodoptera frugiperda insect cells. another baculovirus, vedlh-22, encodes vp2 th ... | 2001 | 11536133 |
| molecular characterization of seven field isolates of infectious bursal disease virus obtained from commercial broiler chickens. | specific-pathogen-free sentinel birds were used as an initial biological system to isolate infectious bursal disease virus (ibdv) field isolates from commercial broiler farms exhibiting recurrent respiratory problems and poor performance. reverse transcription (rt)-polymerase chain reaction (pcr) was used to amplify a 248-bp product encompassing the hypervariable region of the ibdv vp2 gene. restriction fragment length polymorphism (rflp) analysis of the rt-pcr products was performed with the re ... | 2001 | 11569735 |
| detection and persistence of infectious bursal disease virus in specific-pathogen-free and commercial broiler chickens. | in an earlier study, specific-pathogen-free (spf) chickens were inoculated with infectious bursal disease virus (ibdv) at 3 wk of age. their bursas were examined for virus at different intervals postinoculation (pi) by reverse transcriptase (rt)/polymerase chain reaction (pcr) and by virus isolation in chicken embryos up to 21 days pi. the rt/pcr was positive, but attempts to isolate infectious virus from bursal homogenates failed. this prompted us to investigate the persistence of ibdv or its r ... | 2001 | 11569738 |
| use of a genetic marker for wild-type potentially pathogenic infectious bursal disease viruses. | an amino acid mutation at residue 284 (ala to thr) in the vp2 protein of infectious bursal disease viruses (ibdvs) has been correlated with the ability to replicate in cell culture. in this study, we designed a molecular test for this mutation. the reverse transcriptase/polymerase chain reaction (rt/pcr) was used to amplify a 743-bp region of the vp2 gene that contained the codon for amino acid 284. the restriction endonuclease ngomiv was selected for this study because the first three nucleotid ... | 2001 | 11569747 |
| c terminus of infectious bursal disease virus major capsid protein vp2 is involved in definition of the t number for capsid assembly. | infectious bursal disease virus (ibdv), a member of the birnaviridae family, is a double-stranded rna virus. the ibdv capsid is formed by two major structural proteins, vp2 and vp3, which assemble to form a t=13 markedly nonspherical capsid. during viral infection, vp2 is initially synthesized as a precursor, called vpx, whose c end is proteolytically processed to the mature form during capsid assembly. we have computed three-dimensional maps of ibdv capsid and virus-like particles built up by v ... | 2001 | 11602723 |
| dna-mediated vaccination against infectious bursal disease in chickens. | the objective of the present study was to investigate the feasibility of a dna vaccine to protect chickens against infectious bursal disease virus (ibdv) infection. a plasmid dna carrying vp2, vp4, and vp3 genes of the standard challenge (stc) strain of ibdv was constructed and designated as pcr3.1-vp243-stc. one-day-old chickens were intramuscularly injected with the plasmid pcr3.1-vp243-stc once (group d1), twice (group d2), or three times (group d3) at weekly intervals. chickens at 3 weeks ol ... | 2001 | 11672894 |
| characterisation of new zealand isolates of infectious bursal disease virus. | isolates of infectious bursal disease virus (ibdv) were obtained from domestic poultry in new zealand in 1997 and 1998. an in-vivo pathogenicity study carried out in specific pathogen free (spf) chickens demonstrated the low virulence of one of the virus isolates. the nucleotide sequences of the hypervariable region of the vp2 gene of two isolates were determined and compared with published sequences of strains from other countries. the deduced amino acid sequence of the two new zealand ibdv iso ... | 2001 | 11676418 |
| a simple method for screening bacterial colonies for mutagenized sites in plasmid dna. | because of the multiple-step process that is involved in the detection of mutagenized restriction enzyme sites in plasmid dna, a simple and accurate method was developed to analyse the plasmid dna of site-directed mutagenesis experiments from bacterial colonies. the desired mutated part is located between the eco ri restriction site on puc19. two mutagenic primers were designed to replace only one nucleotide on segments a and b of the bi-segmented genome of infectious bursal disease virus (ibdv) ... | 2002 | 11684307 |
| molecular determinants of virulence, cell tropism, and pathogenic phenotype of infectious bursal disease virus. | infectious bursal disease viruses (ibdvs), belonging to the family birnaviridae, exhibit a wide range of immunosuppressive potential, pathogenicity, and virulence for chickens. the genomic segment a encodes all the structural (vp2, vp4, and vp3) and nonstructural proteins, whereas segment b encodes the viral rna-dependent rna polymerase (vp1). to identify the molecular determinants for the virulence, pathogenic phenotype, and cell tropism of ibdv, we prepared full-length cdna clones of a virulen ... | 2001 | 11711587 |
| rescue of infectious bursal disease virus from mosaic full-length clones composed of serotype i and ii cdna. | infectious bursal disease virus (ibdv) is the causative agent of one of the most important and wide-spread infectious diseases among commercial chicken flocks. ibdv causes a depletion of b-lymphoid cells in the bursa of fabricius, inducing immunosuppression, morbidity, or even acute mortality. because currently used live ibdv vaccines are derivatives from field isolates no serologic discrimination between field isolates and live vaccines can be made. the recently developed reverse genetics techn ... | 2001 | 11722019 |
| alteration of amino acids in vp2 of very virulent infectious bursal disease virus results in tissue culture adaptation and attenuation in chickens. | reverse genetics technology offers the possibility to study the influence of particular amino acids of infectious bursal disease virus (ibdv) on adaptation to tissue culture. genomic segments a and b of the very virulent (vv) ibdv field strain uk661 were completely cloned and sequenced, and the strain was rescued from full-length cdna copies of both segments (uk661rev). using site-directed mutagenesis, alteration of a single amino acid in the segment a-encoded vp2 (a284t) resulted in a limited c ... | 2002 | 11752708 |
| efficacy and safety of an infectious bursal disease virus intermediate vaccine in ovo. | the study was divided into two experiments. in the first experiment, the efficacy of in ovo intermediate vaccine against infectious bursal disease virus (ibdv) was determined by challenge at 21 days of age with virulent ibdv in specific-pathogen-free (spf) and commercial chickens. this vaccine was able to induce active immunity and to protect spf chickens to challenge; protection was not complete in commercial chickens, as testified by bursal lesions, bursal index after challenge, and vaccine im ... | 2001 | 11785875 |
| proliferation of lung macrophages in acute fatal viral infections in chickens. | marked proliferation of macrophages engulfing yellow pigments and fragmented erythrocytes were seen in the air capillaries and blood capillaries of the lungs of chickens affected with acute fatal viral hydropericardium syndrome, highly pathogenic infectious bursal disease, and highly pathogenic avian influenza. proliferation of lung macrophages was associated with systemic proliferation of macrophages. acute destruction of erythrocytes in these infections may have induced systemic hyperplasia of ... | 2001 | 11785886 |
| viral and bacterial agents associated with experimental transmission of infectious proventriculitis of broiler chickens. | proventriculitis of broilers can be reproduced by oral inoculation of day-old chicks with a proventricular homogenate from affected 3-wk-old broilers. the objective of the following studies was to isolate from this homogenate viral and bacterial isolates that could produce proventriculitis. a monoclonal antibody to infectious bursal disease virus (ibdv) was used to precipitate virus from the homogenate. a primary chicken digestive tract cell culture system was also used to isolate virus from a 0 ... | 2001 | 11785888 |
| pathogenicity of cell culture-derived and bursa-derived infectious bursal disease viruses in specific-pathogen-free chickens. | that passage of infectious bursal disease virus (ibdv) 30 and 40 times in an established cell line (bgm-70) resulted in loss of pathogenicity has been reported; however, both viruses maintained antigenicity and immunogenicity. that the passaged virus might have lost some ability to replicate in the natural host, resulting in lack of antigenic stimulation and a poor immune response, was speculated. in this study, the pathogenicity and the replication of the serorype 1 variant in strain were inves ... | 2001 | 11785889 |
| molecular characteristics of full-length genomic segment a of three infectious bursal disease viruses in china: two attenuated strains and one virulent field strain. | the full-length cdna of genomic segment a of three infectious bursal disease viruses, two attenuated strains (hz2 and jd1) and one virulent field strain (zj2000), was amplified in a single step by reverse transcription-polymerase chain reaction, cloned into pgem-t easy vector, and sequenced. the full length of cloned segment a contains 3259 nucleotides, which includes two partially overlapping open reading fragments (orfs) orf1 and orf2, flanked by 5' and 3' noncoding regions. these strains shar ... | 2001 | 11785891 |
| detection of infectious bursal disease vaccine viruses in lymphoid tissues after in ovo vaccination of specific-pathogen-free embryos. | control of infectious bursal disease virus (ibdv) by vaccination is important for poultry production worldwide. two vaccines, an ibdv immune complex (icx) vaccine and an ibdv-2512 vaccine, were administered at 100 mean embryo infectious dose to specific-pathogen-free 18-day-old broiler embryos in ovo. at 3, 6, 9, 15, and 21 days post in ovo vaccination (piov), bursa, spleen, and thymus tissues were collected and analyzed for virus protein by antigen capture chemiluminescent enzyme-linked immunos ... | 2001 | 11785894 |
| the genome segment b encoding the rna-dependent rna polymerase protein vp1 of very virulent infectious bursal disease virus (ibdv) is phylogenetically distinct from that of all other ibdv strains. | a full-length cdna clone of the segment b of the very virulent infectious bursal disease virus (ibdv) strain bd 3/99 was constructed and the full-length nucleotide sequence was established. the nucleotide sequence encoding vp1, an rna-dependent rna polymerase, of bd 3/99 was aligned with that of 17 other ibdv strains including six very virulent, three classical virulent, five classical attenuated, one antigenic variant and two serotype 2 strains. the vp1 genes of all very virulent strains were 9 ... | 2001 | 11811695 |
| the maturation process of pvp2 requires assembly of infectious bursal disease virus capsids. | infectious bursal disease virus (ibdv) is a nonenveloped avian virus with a two-segment double-stranded rna genome. its t=13 icosahedral capsid is most probably assembled with 780 subunits of vp2 and 600 copies of vp3 and has a diameter of about 60 nm. vp1, the rna-dependent rna polymerase, resides inside the viral particle. using a baculovirus expression system, we first observed that expression of the pvp2-vp4-vp3 polyprotein encoded by the genomic segment ibda results mainly in the formation ... | 2002 | 11836416 |
| the capsid of infectious bursal disease virus contains several small peptides arising from the maturation process of pvp2. | the capsid proteins vp2 and vp3 of infectious bursal disease virus, a birnavirus, are derived from the processing of a large polyprotein: nh2-pvp2-vp4-vp3-cooh. although the primary cleavage sites at the pvp2-vp4 and vp4-vp3 junctions have been identified, the proteolytic cascade involved in the processing of this polyprotein is not yet fully understood, particularly the maturation of pvp2. by using different approaches, we showed that the processing of pvp2 (residues 1 to 512) generated vp2 and ... | 2002 | 11836417 |
| fate of plasmid dna encoding infectious bursal disease virus vp2 capsid protein gene after injection into the pectoralis muscle of the chicken. | the objective of this study was to determine whether recombinant plasmid dna injected intramuscularly into chickens expressed the gene of interest in vivo and could be subsequently detected in primary and secondary lymphoid tissues with polymerase chain reaction (pcr). the vp2 capsid protein gene of the standard challenge strain (stc) of infectious bursal disease virus (ibdv) was cloned into a eukaryotic plasmid, and purified dna was prepared. fourteen 2-wk-old chickens were injected in the pect ... | 2002 | 11873829 |
| site-directed mutagenesis of avibirnavirus vp4 gene. | virus protein vp4 of infectious bursal disease virus (ibdv) is a protease which separates vpx and vp3 from the polyprotein. we studied the importance of serine and aspartic acid on cleavage at the vpx/vp4 junction and analysed the role of the proposed h547, d590, and s653 catalytic site using five different mutations on vp4. our results suggest that the replacement of serine by lysine in axaas motifs in serotype ii ibdv influences polyprotein (pp) processing by vp4 and also indicate the presence ... | 2002 | 11878927 |
| nucleotide sequence and phylogenetic analysis of a segment of a highly virulent strain of infectious bursal disease virus. | the complete nucleotide sequences encoding precursor polyprotein (vp2-vp3-vp4) and vp5 of a highly virulent (hv) infectious bursal disease virus (ibdv), upm97/61 was determined. comparison of the deduced amino acid sequences with the published ones revealed 8 common amino acid substitutions, which were found only in the hv ibdv including the upm97/61 strain. three of the amino acid substitutions (222 ala, 256 ile and 294 ile) were used as a marker for determining hv ibdv strains. the other five ... | 2001 | 11885928 |
| role of intrabursal t cells in infectious bursal disease virus (ibdv) infection: t cells promote viral clearance but delay follicular recovery. | infectious bursal disease virus (ibdv) induces an acute, highly contagious immunosuppressive disease in young chickens. we examined the role of t cells in ibdv-induced immunopathogenesis and tissue recovery. t cell-intact chickens and birds compromised in their t cell function by a combination of surgical thymectomy and cyclosporin a treatment (tx-csa) were infected with an intermediate vaccine strain of ibdv (bursine 2, fort dodge). our data revealed that functional t cells were needed to contr ... | 2002 | 11890524 |
| genetic and phenotypic correlations between antibody responses to escherichia coli, infectious bursa disease virus (ibdv), and newcastle disease virus (ndv), in broiler lines selected on antibody response to escherichia coli. | the genetic control of antibody (ab) response to escherichia coli (ec), infectious bursa disease virus, and newcastle disease virus and the genetic and phenotypic correlation between these ab responses, were evaluated under farm conditions in which chicks were simultaneously exposed to these antigens. the experimental population comprised five groups: two lines divergently selected for high (hh) or low (ll) ab response to ec vaccination; a commercial broiler dam-line (cc), from which hh and ll h ... | 2002 | 11902404 |
| [enhanced immunogenicity of plasmid encoding polyprotein gene of infectious bursal disease virus by co-administration of chicken interleukin 2 (il-2)]. | chicken interleukin 2 (il-2) is one of important nonmammalian cytokines isolated recently. the influencing of il-2 on immunogenicity of dna vaccine was examined using infectious bursal disease virus as a model. the il-2 cdna of xiaoshan chicken and the polyprotein gene of ibdv-zj2000 were amplified by rt-pcr, cloned, sequenced and inserted into the control of cmv promoter and enhancer of pci vector. 14-day-old chickens were vaccinated intramuscularly with dna vaccine, two weeks later, they were ... | 2001 | 11910759 |
| changes in serum ovotransferrin levels in chickens with experimentally induced inflammation and diseases. | a competitive enzyme immunoassay was developed to measure the changes in serum levels of ovotransferrin (otf) during inflammation and infectious diseases in chickens. the assay is based on the competition of serum otf with a fixed concentration of biotin-labeled otf to bind to a rabbit anti-chicken transferrin antibody immobilized on microtiter wells. after several washing steps, the antibody-bound biotinylated otf is probed with streptavidin-horseradish peroxidase conjugate (hrp) followed by a ... | 2002 | 11922323 |
| pathogenesis and tissue distribution of a variant strain of infectious bursal disease virus in commercial broiler chickens. | the detection of either infectious virus, viral antigen, and/or viral rna in different tissues of commercial broilers inoculated at 1 day of age with e/del variant strain of infectious bursal disease virus (ibdv) was investigated at 2, 4, and 6 wk postinoculation (pi). virus was readily isolated from homogenates of bursa, cecal tonsils, and bone marrow at 2 and 4 wk pi. virus isolation coupled with immunoperoxidase assay or reverse transcription-polymerase chain reaction for ibdv-specific rna ex ... | 2002 | 11922329 |
| complete, long-lasting protection against lethal infectious bursal disease virus challenge by a single vaccination with an avian herpesvirus vector expressing vp2 antigens. | marek's disease herpesvirus is a vaccine vector of great promise for chickens; however, complete protection against foreign infectious diseases has not been achieved. in this study, two herpesvirus of turkey recombinants (rhvts) expressing large amounts of infectious bursal disease virus (ibdv) vp2 antigen under the control of a human cytomegalovirus (cmv) promoter or cmv/beta-actin chimera promoter (pec promoter) (rhvt-cmvvp2 and rhvt-pecvp2) were constructed. rhvt-pecvp2, which expressed the v ... | 2002 | 11991992 |
| specific b lymphocyte suppression by infectious bursal agent (gumboro disease virus) in chickens. | chickens infected experimentally with infectious bursal agent (iba) during embryonation or early after hatching show a severe depression of bursa-dependent lymphoid components, and associated immune functions. data presented here and elsewhere show that the degree of b cell suppression correlates with the time of infection. this would be compatible with a virus-induced block in b lymphocyte differentiation. accordingly, the virus may be cytopathic for early (bursal) but not late (circulating) b ... | 1975 | 11993333 |
| virus enhancement following infection with antibody-coated infectious bursal disease virus (ibdv) in chickens. | a novel concept of vaccination, employing virus-antibody complex has been reported for the control of infectious bursal disease in chickens. a comparison of virus replication, serum neutralizing antibody response and pathogenicity in chickens inoculated with the antibody coated virus, prepared by mixing virus and antibody in different ratios (1:1, 1:0.1, 1: 0.01) and virus alone without antibody, has been made. antibody coated virus (when mixed in certain crucial ratios) replicated to a higher m ... | 2001 | 12018533 |
| antigenic and molecular characterization of recent infectious bursal disease virus isolates in china. | eleven infectious bursal disease virus (ibdv) strains isolated recently from china were compared with the early classical virulent strain cj801, the chicken embryo fibroblast-adapted (cef) variant strain gz902, and the attenuated vaccine strains bj836, bk912, and lm to discern the evolutionary characteristics of ibdv in china at both antigenic and genetic levels. virus neutralization (vn) assay showed that all ten very virulent (vv) ibdv strains belong to the same subtype as attenuated strains, ... | 2002 | 12018704 |
| molecular cloning and characterization of antheraea mylitta cytoplasmic polyhedrosis virus genome segment 9. | genome segment 9 of the 11-segment rna genomes of three cytoplasmic polyhedrosis virus (cpv) isolates from antheraea mylitta (amcpv), antheraea assamensis (aacpv) and antheraea proylei (apcpv) were converted to cdna, cloned and sequenced. in each case, this genome segment consists of 1473 nucleotides with one long orf of 1035 bp and encodes a protein of 345 amino acids, termed nsp38, with a molecular mass of 38 kda. secondary structure prediction showed the presence of nine alpha-helices in the ... | 2002 | 12029164 |
| major histocompatibility complex-linked immune response of young chickens vaccinated with an attenuated live infectious bursal disease virus vaccine followed by an infection. | the influence of the mhc on infectious bursal disease virus (ibdv) vaccine response in chickens was investigated in three different chicken lines containing four different mhc haplotypes. two mhc haplotypes were present in all three lines with one haplotype (b19) shared between the lines. line 1 further contains the bw1 haplotype isolated from a red jungle fowl. line 131 further contains the b131 haplotype isolated from a meat-type chicken. finally, line 21 further contains the international b21 ... | 2002 | 12033414 |
| detection of infectious bursal disease virus in different lymphoid organs by single-step reverse transcription polymerase chain reaction and microplate hybridization assay. | a rapid and sensitive method for the detection of infectious bursal disease virus (ibdv) rna in different chicken lymphoid organs was developed. the method is based on a single-step reverse transcription polymerase chain reaction (rt-pcr) procedure and the enzyme-linked immunosorbent assay (elisa) detection method of amplified products. vaccinal ibdv strain and field isolates were used for the optimization of rt-pcr and for the determination of conditions for microplate hybridization and colorim ... | 2002 | 12033682 |
| chicken anemia virus and infectious bursal disease virus interfere with transcription of chicken ifn-alpha and ifn-gamma mrna. | chicken anemia virus (cav) and infectious bursal disease virus (ibdv) are the two most important viruses that cause immunosuppression in commercial chickens. because inapparent, subclinical infections by these viruses cause immunosuppression, there is need for assessment of the immune status of chickens. interference with induction of transcription for chicken interferon-alpha (chifn-alpha) and chifn-gamma was noted after subclinical infections with either cav or ibdv. because the immunosuppress ... | 2002 | 12034026 |
| amplification and cloning by long rt-pcr of full-length genome of larger segment of chicken infectious bursal disease virus. | to develop the genetic rescue techniques for infectious bursal disease virus (ibdv), birnaviridae family, the full-length cdna of the larger segment of the chicken ibdv was amplified and cloned by long rt-pcr. a comparison of four purification and extraction methods of rna from ibdv infected chicken embryoid fibroblasts (cef) showed that the ultracentrifugation followed by proteinase kdigestion extracted dsrna more effectively. then reverse transcription was carried out at 50 degrees using super ... | 2001 | 12050800 |
| egyptian propolis: 2. chemical composition, antiviral and antimicrobial activities of east nile delta propolis. | three propolis samples from east nile delta, egypt were collected. propolis samples were investigated by gc/ms,103 compounds were identified, 20 being new for propolis. dakahlia propolis was a typical poplar propolis but it contained two new caffeate esters and two new triterpenoids. ismailia propolis was characterized by the presence of new triterpenic acid methyl esters and it did not contain any aromatic acids, esters and flavonoids. sharkia propolis was characterized by the presence of caffe ... | 2002 | 12064745 |
| birnavirus vp1 proteins form a distinct subgroup of rna-dependent rna polymerases lacking a gdd motif. | we have cloned and characterized the drosophila x virus (dxv) genome segment b and its encoded vp1, the putative rna-dependent rna polymerase (rdrp) present in the virion. the 2991-bp open reading frame encodes the largest birnavirus vp1 at 977 aa, with a calculated m(r) of 112.8 kda. as with the vp1 proteins of the type species of the other two genera in the family birnaviridae, namely, infectious pancreatic necrosis virus (genus aquabirnavirus) and infectious bursal disease virus (genus avibir ... | 2002 | 12069523 |
| infectious bursal disease virus structural protein vp2 expressed by a baculovirus recombinant in bombyx mori. | vp2 cdna gene of the infectious bursal disease virus hz96 strain, encoding a major host-protective antigen, was cloned into baculovirus transfer vector pbacpak8, resulting in a recombinant transfer vector pbacpak-vp2. the vector pbacpak-vp2 and linearized dna of modified baculovirus bm-bacpak6 were co-transfected into the cultured bombyx mori (bm) n cells, in which homologous recombination occurred. then, baculovirus recombinants were screened out. the bm cells and bm larvae were infected with t ... | 2000 | 12075455 |
| intentional coinfection of patients with hcv infection using avian infection bursal disease virus. | 2002 | 12085374 | |
| characterisation of an indonesian very virulent strain of infectious bursal disease virus. | an indonesian very virulent (vv) strain of infectious bursal disease virus (ibdv), designated tasik94, was characterised both in vivo and at the molecular level. inoculation of tasik94 into 5-week-old specific-pathogen-free (spf) chickens resulted in 100% morbidity and 45% mortality. the complete nucleotide and predicted amino acid sequences of genomic segments a and b were determined. across each of the three deduced open reading frames (orfs), tasik94 shared the greatest nucleotide homology to ... | 2002 | 12111410 |
| high immunogenicity of the pressure-inactivated virus. | effects of high hydrostatic pressure on the activity of infectious bursal disease virus (ibdv) was described. the infectivity of ibdv decreased with the increasing of pressure and pressurizing time and may be completely lost, indicated by the tests with chicken embryo fibrablast cell and young chicken as models. how-ever, pressure-inactivated ibdv still remained high immunogenicity and might induce high levels of protecting serum antibody. fluorescence spectroscopy showed obvious differences bet ... | 1999 | 12136191 |
| sequence and phylogenetic analysis of the vp2 gene of very virulent infectious bursal disease virus isolates. | previously we have shown that very virulent infectious bursal disease viruses (vvibdv) that are sspi, taqi and styi positive (92/04, 97/61 and 94/b551) but not sspi and taqi positive and styi negative (94/273) cause high mortality, up to 80% in specific-pathogen-free chickens with significant damage of the bursal as well as nonbursal tissues. in this study, we sequenced the vp2 gene (1351 bp) of the 92/04, 94/273 and 94/b551 and compared them with other ibdv strains. all the isolates have the un ... | 2002 | 12186763 |
| a novel transcutaneous plasmid-dimethylsulfoxide delivery technique for avian nucleic acid immunization. | in this report, we show that dimethylsulfoxide (dmso) enhances liposome-mediated transfection of nucleic acid in chicken macrophage cells and that this could be exploited for the transcutaneous delivery of naked dna through the intact skin of chickens. we found that dmso enhanced transfection efficiencies of lipofectamine and polyethyleneimine in hd-11 chicken macrophage cells. based on this principle, we showed that transcutaneous delivery of a dna plasmid-dimethylsulfoxide mixture (1:1) to unt ... | 2002 | 12208052 |
| exchange of the c-terminal part of vp3 from very virulent infectious bursal disease virus results in an attenuated virus with a unique antigenic structure. | infectious bursal disease virus (ibdv) is the major viral pathogen in the poultry industry. live attenuated serotype 1 vaccine strains are commonly used to protect susceptible chickens during their first 6 weeks of life. wild-type serotype 1 ibdv strains are highly pathogenic only in chickens, whereas serotype 2 strains are apathogenic in chickens and other birds. here we describe the replacement of the genomic double-stranded rna (dsrna) encoding the n- or c-terminal part of vp3 of serotype 1 v ... | 2002 | 12239311 |
| quantitative measures of disease in broiler breeder chicks of different major histocompatibility complex genotypes after challenge with infectious bursal disease virus. | criteria for evaluating genetic differences in resistance and susceptibility to infectious bursal disease (ibd) within a commercial broiler breeder line of chickens were compared. line a broiler breeder chickens were challenged with graded doses of animal and plant health inspection service (aphis) strain ibd virus (ibdv) and evaluated at 2 time points, 3 days postinoculation (pi) and 10 days pi. measures obtained at both time points included bursa to body weight, bursa histology, bursa lymphocy ... | 2002 | 12243521 |
| field trial in commercial broilers with a multivalent in ovo vaccine comprising a mixture of live viral vaccines against marek's disease, infectious bursal disease, newcastle disease, and fowl pox. | a multivalent in ovo vaccine (miv) was tested for safety and efficacy in a commercial broiler complex. the miv comprised five replicating live viruses including serotypes 1, 2, and 3 of marek's disease virus (mdv), an intermediate infectious bursal disease virus (ibdv) and a recombinant fowl poxvirus (fpv) vector vaccine containing hn and f genes of newcastle disease virus (ndv). the performance of miv-vaccinated broilers was compared with that of hatchmates that received turkey herpesvirus (hvt ... | 2002 | 12243525 |
| hypoglycemia spiking mortality syndrome in broilers with rickets and a subsequent investigation of feed restriction as a contributing factor. | several cases of elevated mortality with neurologic signs in 14-to-16-day-old broilers were presented to the poultry diagnostic and research center from one local integrated company. suspected of "spiking mortality" associated with hypoglycemia, blood glucose levels were <150 mg/dl overall, with several birds with blood glucose levels as low as 30 mg/dl. tissues, submitted for histopathology, revealed rickets in 50% of the birds. virus isolation and serology for reovirus and infectious bursal di ... | 2002 | 12243543 |
| anti-idiotypic antibody specific for an infectious bursal disease virus-neutralizing monoclonal antibody does not interfere with the virus infection. | infectious bursal disease virus (ibdv) capsid protein, vp2, contains a hypervariable domain that is recognized by virus-neutralizing antibodies. the virus-neutralizing epitope is highly conformation-dependent and the domain is speculated to be involved in the virus-target cell interaction. in this study, a polyclonal anti-idiotypic antibody (anti-id) was generated by the sequential immunization of a rabbit with a virus-neutralizing monoclonal antibody gi-11 which recognizes the vp2 hypervariable ... | 2002 | 12376762 |
| the value of tissue imprint hybridization for rapid detection of infectious bursal disease virus from field outbreaks. | the use of a peroxidase labelled pcr generated probe followed by enhanced chemiluminescence hybridization assay detected infectious bursal disease virus directly from bursal imprints on a nylon membrane. tissue imprint hybridization proved to be a simple, rapid and safe means of detecting ibd virus for screening large numbers of field samples. the pcr generated probe was highly specific for ibd virus and did not hybridize with cellular nucleic acids in control imprints. tissue imprint hybridizat ... | 2002 | 12379057 |
| protective immunity against infectious bursal disease virus in chickens in the absence of virus-specific antibodies. | the role of cell-mediated immunity (cmi) in pathogenesis of infectious bursal disease virus (ibdv) was investigated. one-day-old specific pathogen-free chickens were treated with 3mg of cyclophosphamide (cy) per chicken for 4 consecutive days and, 3 weeks later, infected with the ibdv-im strain. chickens were examined for: (a) mitogenic response of splenocytes to cona, as an indicator of t-cell functions in vitro, (b) antibody against ibdv by elisa, (c) ibdv genome in various tissues by rt-pcr a ... | 2002 | 12383646 |
| the role of t cells in protection by an inactivated infectious bursal disease virus vaccine. | the current belief is that the humoral immune response plays the principal role in defense against virulent infectious bursal disease virus (ibdv). in this study we used a model, in which chickens were compromised in functional t cells by neonatal thymectomy and cyclosporin a (txcsa) treatment, to demonstrate the role of t cells in protective immunity against ibdv. we demonstrated that t cells were necessary to achieve full protection against virulent ibdv. when t cell compromised txcsa-treated ... | 2002 | 12383647 |
| [expression of polyprotein of infectious bursal disease virus in bombyx mori]. | segment a of the genome of infectious bursal disease virus(ibdv) encodes structure protein vp2 and vp3 and protease vp4. in this study a polyprotein gene of ibdv was inserted into a bombyx mori baculovirus transfer vector pachlt--c and contransfected into bmn cells with linear genome dna of virus bm-bacpak6. dot hybridization suggested that the segment a of the virus genome was inserted in the genome of bm-bacpak6. the silkworm of fifth instars were infected by the recombinant virus and the immu ... | 2002 | 12385246 |
| nucleotide sequence analysis of variable region of vp2 gene of two infectious bursal disease virus isolates from commercial poultry farms. | two infectious bursal disease virus (ibdv) isolates were obtained from commercial poultry farms with a history of severe outbreaks. a 474-bp product encompassing hypervariable region of ibdv vp2 gene was amplified by reverse transcription-polymerase chain reaction (rt-pcr). the nucleotide sequences of two isolates, vmb1 and vmb2, were determined and compared with those of twenty ibdv strains, including seven very virulent, four classical virulent, four classical attenuated, three antigenic varia ... | 2002 | 12387501 |
| infectious bursal disease virus capsid protein vp3 interacts both with vp1, the rna-dependent rna polymerase, and with viral double-stranded rna. | infectious bursal disease virus (ibdv) is a double-stranded rna (dsrna) virus of the birnaviridae family. its two genome segments are encapsidated together with multiple copies of the viral rna-dependent rna polymerase, vp1, in a single-shell capsid that is composed of vp2 and vp3. in this study we identified the domains responsible for the interaction between vp3 and vp1. using the yeast two-hybrid system we found that vp1 binds to vp3 through an internal domain, while vp3 interacts with vp1 so ... | 2002 | 12388690 |
| susceptibility of vaccinated and unvaccinated egyptian chickens to very virulent infectious bursal disease virus. | the responses of vaccinated and unvaccinated chickens of different breeds to infection with very virulent infectious bursal disease virus (vvibdv) were investigated. five-week-old chickens of five egyptian breeds (fayoumi, balady, golden, mandarah, and gimmizah), and foreign white leghorn pullets were tested. in unvaccinated birds, mortality, relative bursa and spleen weight, bursal lesion score, antibody titres and the response of blood lymphocytes to mitogens were examined. the gimmizah and fa ... | 2002 | 12396359 |
| risk factors associated with the introduction of acute clinical infectious bursal disease among danish broiler chickens in 1998. | the objective of the present study was to investigate risk factors associated with the introduction of acute clinical infectious bursal disease (ibd) among danish broiler chickens in 1998. data on 218 flocks were collected from hatcheries, abattoirs, farmers and veterinarians; 49 of the flocks had experienced acute clinical ibd (cases), 169 were unexposed (controls). the study was carried out using a case-control design. cases were defined as the first flock on each premises to experience acute ... | 2002 | 12425789 |
| characterization of the antigenic, immunogenic, and pathogenic variation of infectious bursal disease virus due to propagation in different host systems (bursa, embryo, and cell culture). i. antigenicity and immunogenicity. | in vitro and in ovo virus neutralization assays were conducted to assess the role of different host systems in infectious bursal disease virus (ibdv) antigenic and immunogenic variation. four different strains, two variant (1084 e and gls) and two standard (edgar and stc), were propagated separately in the bursa of fabricius and embryos, and were compared with cell culture-adapted preparations of the homologous strains. chicken polyclonal antisera were prepared against each ibdv and neutralizing ... | 2002 | 12427340 |
| characterization of the antigenic, immunogenic, and pathogenic variation of infectious bursal disease virus due to propagation in different host systems (bursa, embryo, and cell culture). ii. antigenicity at the epitope level. | antigenic variation of infectious bursal disease virus (ibdv) due to propagation in different host systems (bursa of fabricius, embryos, or cell cultures) was determined by enzyme-linked immunosorbent assay (indirect and antigen capture) and western blot analysis. to conduct this study, we used 27 non-neutralizing anti-vp(2) monoclonal antibodies, a reference panel of nine neutralizing monoclonal antibodies, and 13 neutralizing anti-ibdv chicken polyclonal antibodies. changes occurred in neutral ... | 2002 | 12427341 |
| characterization of the antigenic, immunogenic, and pathogenic variation of infectious bursal disease virus due to propagation in different host systems (bursa, embryo, and cell culture). iii. pathogenicity. | differences in the relative pathogenicity of variant (1084 e and gls) and standard (edgar and stc) infectious bursal disease virus (ibdv) strains were observed after propagation in the bursa of fabricius, embryos, or cell cultures. bursa-derived ibdv induced the most severe lesions in the bursa of fabricius when compared with strains propagated in embryos or cell cultures. embryo-derived ibdv induced moderate gross bursal lesions, whereas cell culture-derived ibdv did not damage the bursa grossl ... | 2002 | 12427342 |