Publications
| Title | Abstract | Year(sorted descending) Filter | PMID Filter |
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| significance of the genetic relationships deduced from partial nucleotide sequencing of infectious bursal disease virus genome segments a or b. | the rapid genomic characterization of infectious bursal disease virus (ibdv) requires determining which partial nucleotide (nt) sequences derived from ibdv segments a or b would produce phylogenetic information as significant as sequencing the whole corresponding segments. long nt coding sequences of 27 ibdv segments a (aa 20-991) and 21 segments b (aa 7-stop codon) were retrieved from databanks and used to compute reference phylogenetic trees using neighbor joining (nj) and parsimony (p): clust ... | 2005 | 15503222 |
| molecular studies on suspect very virulent infectious bursal disease virus genomic rna samples. | infectious bursal disease (ibd) associated with high mortality was first observed in europe in the mid-1980s. the viruses identified in those outbreaks were described as being very virulent infectious bursal disease virus (vvibdv) strains. these viruses have spread to nearly every continent but have not yet been identified in north america, australia, and new zealand. there is a real and immediate concern that the very virulent form of ibdv will continue to spread until it is present on every co ... | 2005 | 16094830 |
| purification of capsid-like particles of infectious bursal disease virus (ibdv) vp2 expressed in e. coli with a metal-ion affinity membrane system. | protein vp2, matured from the polyprotein encoded by the genome of infectious bursal disease virus (ibdv) and the primary host-protective immunogen of this virus, together with its two n-terminal truncated mutants were cloned and expressed in escherichia coli. to obtain pure recombinant proteins for the development of an efficient subunit vaccine against ibdv infection, these three proteins were fused with six additional histidine residues at their c-termini as a his-purification-tag. following ... | 2005 | 16040134 |
| structural polymorphism of the major capsid protein of a double-stranded rna virus: an amphipathic alpha helix as a molecular switch. | the infectious bursal disease virus t=13 viral particle is composed of two major proteins, vp2 and vp3. here, we show that the molecular basis of the conformational flexibility of the major capsid protein precursor, pvp2, is an amphipatic alpha helix formed by the sequence gfkdiirair. vp2 containing this alpha helix is able to assemble into the t=13 capsid only when expressed as a chimeric protein with an n-terminal his tag. an amphiphilic alpha helix, which acts as a conformational switch, is t ... | 2005 | 16004873 |
| structure of birnavirus-like particles determined by combined electron cryomicroscopy and x-ray crystallography. | birnaviruses possess a capsid with a single protein layer in contrast to most double-stranded rna viruses infecting multicellular eukaryotes. using freeze-drying and heavy metal shadowing, the capsids of two birnaviruses, infectious bursal disease virus (ibdv) and infectious pancreatic necrosis virus, as well as of an ibdv virus-like particle (vlp) are shown to follow the same t=13 laevo icosahedral geometry. the structure of the vlp was determined at a resolution of approximately 15 a (1.5 nm) ... | 2005 | 16033982 |
| infectious bursal disease virus (ibdv) induces apoptosis in chicken b cells. | the ability of infectious bursal disease virus (ibdv) serotypes 1 and 2, and the role of vp4 of both serotypes as well as the capacity of three ibdv intermediate serotype 1-specific vaccine strains to induce apoptosis in a chicken b-lymphocyte cell line, dt40, were investigated using the tunel technique. it was observed that ibdv serotype 1 infected the dt40 cell line and directly induced apoptosis. in contrast, the non-pathogenic serotype 2 neither infected nor induced apoptosis, but was able t ... | 2005 | 16188316 |
| identification of neutralizing epitopes on the vp2 protein of infectious bursal disease virus by phage-displayed heptapeptide library screening and synthetic peptide mapping. | infectious bursal disease virus (ibdv) is the causative agent of infectious bursal disease, which is one of the most important and widespread infectious diseases in commercial chickens. conformational epitopes have been reported in the highly variable region of the vp2 protein of ibdv. in the present study, a random heptapeptide library was screened by using monoclonal antibodies (mabs), ynw17 and ynw29, directed to the vp2 of ibdv and two peptide motifs, d-x-p-r and a-r-g, were identified. the ... | 2005 | 16212534 |
| preparation of chil-2 and ibdv vp2 fusion protein by baculovirus expression system. | this study aims to produce an effective subunit vaccine against infectious bursal disease virus (ibdv). the genes of chicken interleukin-2 (chil-2) and ibdv viral protein 2 (vp2) were amplified and fused by splice overlap extension-polymerase chain reaction (soe-pcr). the fusion gene was digested by ecor i/kpn i and inserted into pbacpak8 vector, resulting in recombinant transfer plasmid pbacpakvp2-il2. the recombinant plasmid was transfected into sf-9 cells accompanied with hybrid nuclear polyh ... | 2005 | 16212892 |
| vaccination against very virulent infectious bursal disease virus using recombinant t4 bacteriophage displaying viral protein vp2. | in order to develop a desirable inexpensive, effective and safe vaccine against the very virulent infectious bursal disease virus (vvibdv), we tried to take advantage of the emerging t4 bacteriophage surface protein display system. the major immunogen protein vp2 from the vvibdv strain hk46 was fused to the nonessential t4 phage surface capsid protein, a small outer capsid (soc) protein, resulting in the 49 kda soc-vp2 fusion protein, which was verified by sodium dodecylsulfate polyacrylamide ge ... | 2005 | 16215632 |
| temporal and spatial analysis of the 1999 outbreak of acute clinical infectious bursal disease in broiler flocks in denmark. | the objective of this study was to describe the spatial and temporal dynamics of the 1999 outbreak of acute clinical infectious bursal disease (ibd) in broiler chicken farms in denmark. the analysis was performed using data from all broiler farms located in the jutland peninsula and the island of funen (168 municipalities). the moran's index i, k-functions and scan statistics were used to describe the dynamics of the epidemic. in addition, spatially correlated survival analyses were performed an ... | 2005 | 16227094 |
| viral genotyping of infectious bursal disease viruses isolated from the 2002 acute outbreak in spain and comparison with previous isolates. | an infectious bursal disease (ibd) outbreak occurred in the east region of spain in the spring of 2002 and rapidly spread thorough the whole country, although proper vaccination programs were applied. in this report, 33 infectious bursal disease viruses (ibdvs) isolated from this outbreak were characterized by nucleotide sequencing of the vp2 gene hypervariable region and were compared with reference ibd strains and the 1990s spanish ibdvs in order to determine possible emergence of ibdv isolate ... | 2005 | 16252484 |
| reproduction of proventriculitis in commercial and specific-pathogen-free broiler chickens. | proventriculitis was studied by experimentally reproducing the disease in broiler chickens. one-day-old infectious bursal disease virus (ibdv) and infectious bronchitis virus (ibv) antibody positive commercial broilers and 1-day-old antibody negative specific-pathogen-free (spf) broilers were orally gavaged with proventricular homogenates produced from the proventriculi of broilers with proventriculitis. at 7 and 14 days, both commercial and spf broilers had enlargement of the proventriculus wit ... | 2005 | 16252487 |
| intracellular interference of infectious bursal disease virus. | a search for dominant-negative mutant polypeptides hampering infectious bursal disease virus (ibdv) replication has been undertaken. we have found that expression of a mutant version of the vp3 structural polypeptide known as vp3/m3, partially lacking the domain responsible for the interaction with the virus-encoded rna polymerase, efficiently interferes with the ibdv replication cycle. transformed cells stably expressing vp3/m3 show a significant reduction (up to 96%) in their ability to suppor ... | 2005 | 16254378 |
| differentiation of five strains of infectious bursal disease virus: development of a strain-specific multiplex pcr. | infectious bursal disease virus (ibdv) is a major cause of disease problems in the poultry industry and vaccination has therefore been applied intensively to control the infection. the classical methods of detection and characterization of ibdv are by the use of immunodiffusion test and histopathology. since these methods are laborious and have low specificity alternatives are needed. in the present study, we report the development of a strain-specific multiplex rt-pcr technique, which can detec ... | 2005 | 15994031 |
| real-time rt-pcr analysis of two epitope regions encoded by the vp2 gene of infectious bursal disease viruses. | infectious bursal disease virus (ibdv) causes an immunosuppressive disease in chickens and leads to severe economic losses in the poultry industry. vaccination may not be effective if there is exposure of the vaccinated flock to a different antigenic subtype, which reinforces the importance of identification of new ibdv variants. the virus outer capsid is constituted of vp2, in which the major neutralizing epitopes are located. forty-eight bursa samples collected from ibdv infected commercial br ... | 2005 | 16023522 |
| infectious bursal disease virus recovery from vero cells transfected with rna transcripts is enhanced by expression of the structural proteins in trans. | positive sense rna transcripts of infectious bursal disease (ibd) virus genome segments a and b have previously been shown to be infectious. in this study we demonstrate that recovery of ibd virus from the transfection of vero cells with positive sense rna transcripts of genome segments a and b was enhanced by expression of the viral structural proteins vp2 with vp3 or by expression of viral polyprotein vp243 from dna plasmids in trans. expression of individual viral proteins vp2, vp3, or vp4 al ... | 2005 | 16086099 |
| development of a one-step strip test for the diagnosis of chicken infectious bursal disease. | a rapid diagnostic strip for chicken infectious bursal disease (ibd) was developed based on membrane chromatography using high-affinity monoclonal antibodies directed to chicken infectious bursal disease virus (ibdv). the diagnostic strip has high specificity for detection of chicken ibdv antigen and recognizes a variety of the virus isolates, including virulent and attenuated strains, with no cross-reactivity to other viruses, such as newcastle disease virus, marek's disease virus, infectious b ... | 2005 | 16094819 |
| molecular epidemiology of infectious bursal disease viruses: distribution and genetic analysis of newly emerging viruses in the united states. | genetic mutations in the genome of infectious bursal disease virus (ibdv) have resulted in antigenic and pathogenic variants that continue to cause disease in commercially reared chickens. the extent of the genetic diversity among ibdv strains circulating in the united states is unknown. this study was designed to identify newly emerging viruses infecting chickens on poultry farms experiencing immune suppression-related problems. fifty ibdv-positive samples were identified from 273 bursa samples ... | 2005 | 16094826 |
| protective efficacy of intermediate and intermediate plus infectious bursal disease virus (ibdv) vaccines against very virulent ibdv in commercial broilers. | the evolution of very virulent (vv) infectious bursal disease virus (ibdv) has led to significant economic losses in many poultry-producing areas. despite vigorous vaccination strategies, ibdv has been difficult to control. the protective efficacy of ibdv vaccines is traditionally evaluated in specific pathogen-free (spf) chickens. but under field conditions, residual maternal antibody (mab) levels may interfere with vaccine efficacy. in this study, commercial broilers with various levels of mat ... | 2005 | 16094828 |
| synthesis of reassortant infectious bursal disease virus in chickens injected directly with infectious clones from different virus strains. | the infectious bursal disease virus (ibdv), a member of the birnaviridae family, containing a bisegmented double-stranded rna genome, encodes four structural viral proteins, vp1, vp2, vp3, and vp4, as well as a non-structural protein, vp5. in the present paper, the segment a from two ibdv strains, field isolate zj2000 and attenuated strain hz2, were inserted into one naei site by site-directed silent mutagenesis and subcloned into the eukaryotic expression plasmid pci under the control of the hu ... | 2005 | 15756422 |
| enhanced immunopathology induced by very virulent infectious bursal disease virus. | immunohistochemical and flow cytometric analyses of the bursa, spleen and thymus following infection with the very virulent infectious bursal disease virus (vvibdv) strain uk661 revealed discrete differences from classical virulent infectious bursal disease virus strains. bu-1+, immunoglobulin (ig)m+ and igg+ cells were all depleted from the bursa, spleen and thymus, suggesting loss of both immature and mature b lymphocytes. small numbers of bu-1+ cells repopulated the bursa 14 days post-infecti ... | 2005 | 15763733 |
| early and transient induction of nitric oxide (no) in infectious bursal disease virus infection is t-cell dependent: a study in cyclosporin-a treated chicken-model. | the level of nitric oxide (no) in the supernatants of mitogen (pha) stimulated lymphocyte cultures from infectious bursal disease (ibd) virus infected t-cell suppressed and immune competent chickens was monitored. the immune competent chickens when infected with ibd virus showed 4-6 folds increased levels of no as compared to uninfected chickens. the levels of no in t-cell suppressed chickens were comparable to uninfected control chickens, in spite of markedly increased hemorrhage suggesting tha ... | 2005 | 15782823 |
| infectious bursal disease virus-induced immunosuppression in the chick is associated with the presence of undifferentiated follicles in the recovering bursa. | infectious bursal disease virus (ibdv) causes an acute cytolytic infection in chicken b lymphocytes resulting in destruction of the b-cell population. most severe depletion occurs in the bursa of fabricius, where the immunoglobulin repertoire is developed by gene conversion. chicks surviving ibdv infection are immunosuppressed despite repopulation of the bursa with b cells. here we show that infection of neonatal chicks with a classical virulent ibdv strain (f52/70) causes severe bursal bcell de ... | 2005 | 15802957 |
| pigeon paramyxovirus: association with common avian pathogens in chickens and serologic survey in wild birds. | pigeon paramyxovirus-1 (ppmv-1) was isolated from pigeons from east-central alabama and used in association with chicken anemia virus (cav), infectious bursal disease virus (ibdv), or finch mycoplasma gallisepticum (mg) in specific-pathogen-free chickens to assess dinical disease and pathology. ppmv-1 infection in all groups was conducted at day 10 of age via the ocular route. the low passage ppmv-1 isolate was inoculated into chickens in different groups at 10 days post-cav infection, 6 days po ... | 2005 | 15839419 |
| interference between mild and pathogenic strains of infectious bursal disease virus in chickens. | infectious bursal disease virus is a contagious, immunosuppressive disease of young chickens that is controlled by vaccination. cross-protection occurs between different strains of the virus as a result of shared neutralizing epitopes. however, interactions between two antigenically similar strains (a mild and a pathogenic) coinfecting the same host have not been investigated. groups of specific-pathogen-free chickens were inoculated with a mild strain followed by a pathogenic strain at 0, 16, 2 ... | 2005 | 15839420 |
| infection and activation of bursal macrophages by virulent infectious bursal disease virus. | in this study the effect of infectious bursal disease virus (ibdv) on bursal macrophages during the acute phase of the infection was examined. specific-pathogen-free (spf) chickens were exposed to virulent ibdv and bursal adherent cells were examined by immunohistochemisrty and rt-pcr for virus infection and by real-time quantitative rt-pcr (qrt-pcr) for mrna transcripts of proinflammatory cytokines and inos. viral genome was detected in bursal macrophages at 3, 5 and 7 days post-infection (dpi) ... | 2005 | 15893401 |
| real-time rt-pcr differentiation and quantitation of infectious bursal disease virus strains using dual-labeled fluorescent probes. | a real-time rt-pcr assay was developed utilizing dual-labeled fluorescent probes binding to vp4 sequence that are specific to the classical (cl), variant (v) and very virulent (vv) strains of infectious bursal disease virus (ibdv). the assay was highly sensitive and could detect as little as 3 x 10(2) to 3 x 10(3) copies of viral template. viral genomic copy number could be accurately assayed over a broad range of 7-8 logs of viral genome. the variant sequence-specific probe was found to be high ... | 2005 | 15893570 |
| differences in the immunopathogenesis of infectious bursal disease virus (ibdv) following in ovo and post-hatch vaccination of chickens. | not much is known about ibdv-pathogenesis and immune mechanisms following in ovo vaccination. in this study, we compared the immunopathogenesis of an intermediate ibdv-vaccine in post-hatch- and in ovo-inoculated chickens. in ovo-vaccinated birds recovered significantly faster from lesions of the bursa of fabricius than post-hatch vaccinated (p<0.05). a significant accumulation of intrabursal cd8(+) t cells was observed in post-hatch but not in in ovo-vaccinated chickens (p<0.05). the innate imm ... | 2005 | 15911001 |
| molecular characterization of infectious bursal disease virus isolates from nepal based on hypervariable region of vp2 gene. | two infectious bursal disease virus (ibdv) isolates, np1ssh and np2k were obtained from a severe infectious bursal disease (ibd) outbreak in nepal in 2002. the hypervariable (hv) region of vp2 gene (1326 bp) of the isolates was generated by rt-pcr and sequenced. the obtained nucleotide sequences were compared with those of twenty other ibdv isolates/strains. phylogenetic analysis based on this comparison revealed that np1ssh and np2k clustered with very virulent (vv) ibdv strains of serotype 1. ... | 2005 | 15929400 |
| vaccine and adjuvant activity of recombinant subunit b of e. coli enterotoxin produced in yeast. | escherichia coli heat-labile enterotoxin (lt) and cholera toxin (ct) have been studied intensively as vaccines against diseases caused by those bacteria and as adjuvants for mucosal vaccination. two major problems interfere with the use of these promising adjuvants: their toxicity and the residual bacterial endotoxins mixed with the desired lt. in this study, subunit b of lt was expressed in pichia pastoris yeast cells (yrltb) and the recombinant protein was purified and concentrated by ion-exch ... | 2005 | 15951067 |
| oesophageal tonsil of the chicken. | the oesophageal tonsil of the chicken is a novel member of the mucosal-associated lymphoid tissue (malt), which is located around the entrance of the proventriculus. it consists of 6 to 8 single units, which are surrounded by a thin fibrous capsule. each one is organised around the bottom of the longitudinal folds of the oesophagus, and serves as a 'tonsillar crypt'. stratified squamous epithelium is infiltrated by lymphoid cells, i.e. t cells, plasma cells, macrophages, and dendritic cells, but ... | 2005 | 15959976 |
| dna immunization against very virulent infectious bursal disease virus with vp2-4-3 gene and chicken il-6 gene. | the present study was to investigate the feasibility and efficiency of the dna vaccine to protect chickens against very virulent infectious bursal disease virus (vvibdv) infection. a plasmid dna carrying vp2-4-3 genes of vvibdv sh95 and a plasmid dna carrying chicken interleukin-6 (chil-6) genes were constructed and designated as palter-max-vp2-4-3 and palter-max-chil-6 respectively. several dna vaccination experiments were performed: 1-week-old chickens were intramuscularly injected with only p ... | 2005 | 15702994 |
| effects of dietary ratio of linoleic to linolenic acid on performance, antibody production, and in vitro lymphocyte proliferation in two strains of leghorn pullet chicks. | the effects of dietary ratio of linoleic acid to linolenic acid on performance, mitogenic lymphocyte proliferation, and antibody production were evaluated in leghorn pullets during a rigorous vaccination program. diets were supplemented with flaxseed and corn oil to achieve 4 dietary ratios of linoleic acid to linolenic acid [17:1 (control), 8:1, 4:1, or 2:1]. each diet was fed to hyline brown or w-36 pullets from 1 d to 16 wk of age. day-old pullets were randomly assigned to 8 replicate cages w ... | 2005 | 15971520 |
| delayed vaccine virus replication in chickens vaccinated subcutaneously with an immune complex infectious bursal disease vaccine: quantification of vaccine virus by real-time polymerase chain reaction. | the distribution of the immune complex vaccine virus for infectious bursal disease (ibd) in tissue was examined and the viral loads of the organs were quantitatively compared. one-day-old specific pathogen free (spf) and maternally immune broiler chickens were injected subcutaneously with the vaccine. lymphoid and non-lymphoid tissues were collected at various time intervals during the experiment to test for infectious bursal disease virus (ibdv)-rna by using reverse transcriptase-polymerase cha ... | 2005 | 15971678 |
| development of recombinant vp2 vaccine for the prevention of infectious bursal disease of chickens. | the objective of the present study was to investigate the feasibility of a subunit vaccine and a live bacteria vaccine to protect chickens against infectious bursal disease virus (ibdv) infection. the gene for vp2 of a new wild-type very virulent ibdv (vvibdv) strain was cloned into an escherichia coli expression system. following expression, the recombinant vp2 and the induced expression bacteria were used to vaccinate chickens against virulent ibdv (vibdv). three weeks after the vaccination, c ... | 2005 | 15979770 |
| an elisa for detection of infectious bursal disease virus and differentiation of very virulent strains based on single chain recombinant chicken antibodies. | two chicken single-chain variable antibody fragments (scfv) designated scfv154 and scfv88, previously shown to react with either all or very virulent (vv) infectious bursal disease virus (ibdv) strains, respectively, were evaluated for use in an enzyme-linked immunosorbent assay (elisa) for differentiation of vvibdv. specificity and sensitivity of the vvibdv elisa was assessed when scfv154 and scfv88 were expressed as soluble antibodies (sab), phage antibodies (pab) or hyper-phage antibodies (hp ... | 2005 | 16537158 |
| evaluation of the enzyme-linked immunosorbent assay for the detection of antibodies against infectious bursal disease virus (ibdv) and the estimation of the optimal age for ibdv vaccination in broilers. | in order to evaluate the usefulness of the enzyme-linked immunosorbent assay (elisa) in determining the optimal age for infectious bursal disease virus (ibdv) vaccination in broilers under field circumstances, the percentage of birds susceptible to vaccine at vaccination age was estimated in 12 flocks on the basis of elisa titres in newborn chicks. the effective percentage of susceptible birds at the day of vaccination was checked by comparing virus neutralization (vn) titres measured in sera ta ... | 2005 | 16537166 |
| detection of vvibdv in vaccinated spf chickens. | the purpose of our experiment was to investigate, if apparently healthy, vaccinated chickens may be involved in maintaining and spreading infectious bursal disease virus (ibdv) in poultry environments. we aimed at simultaneous detection and identification of very virulent field strain ibdv (vvibdv) as well as vaccine strain ibdv in experimentally infected chickens. two groups of specific pathogen free (spf) chickens were vaccinated using the intermediate infectious bursal disease (ibd) vaccine d ... | 2005 | 16398333 |
| genotyping of infectious bursal disease virus strains by restriction fragment length polymorphism analysis of the vp1, vp2, and vp3 genes. | summary. this study aimed to genotype infectious bursal disease virus (ibdv) isolates from the minas gerais state poultry industry. rna was extracted from bursae obtained from field cases without passage or commercial vaccines. genetic subtyping of ibdv isolates and vaccine strains was carried out by the reverse transcriptase-polymerase chain reaction (rt-pcr) and restriction fragment length polymorphism (rflp) analysis. a 588-bp fragment in the vp1 gene, an 847-bp fragment in the vp2 gene, and ... | 2005 | 16404990 |
| detection of infectious bursal disease virus in various lymphoid tissues of experimentally infected specific pathogen free chickens by different reverse transcription polymerase chain reaction assays. | infectious bursal disease (ibd) is a worldwide distributed immunosuppressive viral disease in young chickens, controlled by vaccination. emergence of several strains of ibd virus (ibdv) has created a demand for strain-specific diagnostic tools. in the present experiment, five different reverse transcription polymerase chain reaction (rt-pcr) assays, including two recently developed strain-specific assays, were employed for detection of ribonucleic acid (rna) from three different ibdv strains in ... | 2005 | 16404995 |
| [cloning, expression and preparation of polyclonal antibody for ibdv non-structure protein gene]. | infectious bursal disease virus (ibdv) vp5 gene was amplified and cloned into an n-terminal gst-tag fusion expression vector, pgex-4t-2, which was controlled by t7 promoter. the sequencing result showed that the vp5 gene was composed of 438 base pairs, and coded 145 amino acids. high vp5 product was expressed in e. coli bl21 induced by iptg, and the gst-vp5 fusion protein existed in inclusion. high titer anti-vp5 serum was also prepared in new zealand rabbit immunized with purified fusion protei ... | 2005 | 16342772 |
| aflatoxicosis, infectious bursal disease and immune response to newcastle disease vaccination in rural chickens. | to investigate the immunosuppressive effects of infectious bursal disease virus (ibdv) and aflatoxin in indigenous chickens of uganda, newcastle disease (nd) seronegative chicks were randomly allocated to two treatment groups. group a chicks were injected intramuscularly at the age of 3 weeks every 2 days up to four times with 0.250 mg aflatoxin b1 per bird, group b was infected occulo-nasally with ibdv 3 days prior to vaccination, while group c was left as a control group. all the chicks from t ... | 2005 | 16147568 |
| evaluation of the suitability of six host genes as internal control in real-time rt-pcr assays in chicken embryo cell cultures infected with infectious bursal disease virus. | infectious bursal disease virus (ibdv) can cause disease in chickens characterized by immunosuppression and high mortality. currently, real-time rt-pcr has been used to quantitate virus-specific rna and to better understand host response to infection. however, normalization of quantitative real-time rt-pcr is needed to a suitable internal control. we thus investigated the expression pattern of six chicken genes, including beta-actin, 28s rrna, 18s rrna, glyceraldehyde-3-phosphate dehydrogenase ( ... | 2005 | 16159698 |
| two outbreaks of very virulent infectious bursal disease virus in pakistan. | 2005 | 16361477 | |
| haematological and histological findings in leghorn chickens infected with infectious bursal disease virus strain 73688. | in the present study, specific-pathogen-free, 2-week-old leghorn chickens were experimentally infected with strain 73688 of infectious bursal disease virus (ibdv) in order to evaluate haematological and histological changes that might suggest a pathomechanism for haemorrhages in this disease. at 96 hours post infection (hpi) a significant increase in prothrombin time was detected in the absence of visible lesions in myeloid bone marrow tissue and of significant thrombocytopenia. the aforemention ... | 2005 | 16363151 |
| secreted expression of the vp2 protein of very virulent infectious bursal disease virus in the methylotrophic yeast pichia pastoris. | the vp2-encoding gene of very virulent infectious bursal disease virus (vvibdv) was amplified using reverse transcription (rt)-polymerase chain reaction (pcr) and inserted into ppiczalphaa vector. recombinant plasmid dna was integrated into the chromosome of the transformed pichia pastoris by electroporation and expressed protein identified by sds-page and western blotting. high-level secreted expression was performed by determining the mut+ phenotype and secreting multi-copy integrants in the r ... | 2005 | 15620405 |
| virus strains from a flock exhibiting unusually high mortality due to infectious bursal disease. | to characterise infectious bursal disease viruses (ibdvs) isolated from commercial broiler flocks exhibiting unusually high mortality due to infectious bursal disease (ibd). | 2004 | 15648939 |
| the enhanced virulence of very virulent infectious bursal disease virus is partly determined by its b-segment. | there is a remarkable difference in virulence of infectious bursal disease virus (ibdv) strains ranging from sub-clinical infections for serotype 2 and cell culture adapted serotype 1 strains, to 100% mortality for very virulent serotype 1 strains in young spf chickens. it is known that cell culture adaptation related attenuation is determined by distinct mutations in the hypervariable region of the vp2 outer capsid protein, encoded on the a-segment. amino acid mutations in the hypervariable vp2 ... | 2004 | 15654506 |
| a very virulent genotype of infectious bursal disease virus predominantly associated with recurrent infectious bursal disease outbreaks in tunisian vaccinated flocks. | outbreaks of infectious bursal disease (ibd) still continue to afflict the tunisian poultry industry even in those flocks where the vaccination program is strictly applied. to characterize the viruses that circumvent protection provided by vaccination, field isolates of infectious bursal disease virus (ibdv) obtained from vaccinated flocks that have repeatedly experienced ibdv outbreak episodes were analyzed from bursal samples by reverse transcription coupled with polymerase chain reaction and ... | 2004 | 15666864 |
| heteroduplex mobility assay for genotyping infectious bursal disease virus. | a heteroduplex mobility assay (hma) was developed to genotype infectious bursal disease virus (ibdv). this method analyzed 390-base pair (bp) polymerase chain reaction (pcr) products, encompassing the hypervariable region of the vp2 gene. ibdv strains from the united states and other countries were analyzed. the hma was able to differentiate standard, antigenic variants and very virulent strains of ibdv. minor differences between different strains from the same subtype were also detected. close ... | 2004 | 15666866 |
| history of biological control of poultry diseases in the usa. | 2004 | 15077792 | |
| changes in vp2 gene during the attenuation of very virulent infectious bursal disease virus strain gx isolated in china. | very virulent (vv) infectious bursal disease virus (ibdv) gx strain with high pathogenicity was attenuated through replication in specific-pathogen-free (spf) chicken embryos and in chicken embryo fibroblast (cef) cell cultures. the changes in vp2 nucleotide and the deduced amino acid sequences were obtained during attenuation of vvibdv in cef culture. sequence analysis of selected passages from numbers 0 to 20 in cefs (designated here gx to cef-20) showed that no changes were detectable in the ... | 2004 | 15077800 |
| relationship of campylobacter isolated from poultry and from darkling beetles in new zealand. | campylobacter, a foodborne pathogen closely associated with poultry, is considered to be an important agent of human gastroenteritis in new zealand. the pathways involved in the contamination of poultry flocks remain unclear; however, many vectors, such as insects, rodents, and wild birds, have been implicated. infestation of poultry houses by insects, particularly darkling beetles (alphitobius diaperinus), is difficult to control. furthermore, darkling beetles are known vectors for a variety of ... | 2004 | 15077807 |
| effect of diffferent levels of maternally derived antibodies on protection against infectious bursal disease virus. | fertile eggs were obtained from three different broiler breeder flocks with different levels of virus neutralizing antibodies to infectious bursal disease virus. egg yolk from these flocks was tested for antibody titers by the virus neutralization test. flock i eggs had no antibodies, flock ii had medium level antibodies (1:200-1600; geometric mean = 1:975), and flock iii had a high level of antibodies (1:1600-6400; geometric mean = 1:3365). chicks from the above flocks were challenged each with ... | 2004 | 15077812 |
| genetic resistance of egyptian chickens to infectious bursal disease and newcastle disease. | genetic resistance of native egyptian breeds to very virulent infectious bursal disease virus (vvibdv) and newcastle disease virus (ndv) was investigated in two experiments. in the first experiment, birds from four breeds (gimmizah, sina, dandrawi and mandarah) were challenged with vvibdv. the mandarah chickens had the lowest mortalities (10%) compared to the gimmizah, sina and dandrawi chickens (55%, 35%, and 55%, respectively). antibody response, lymphocyte response to mitogen, and bursal lesi ... | 2004 | 14979553 |
| antigenic and genetic diversity of early european isolates of infectious bursal disease virus prior to the emergence of the very virulent viruses: early european epidemiology of infectious bursal disease virus revisited? | eleven polish and hungarian isolates of infectious bursal disease virus (ibdvs) obtained in the 70/80s (early ibdv) and in the 90s (recent ibdv) were characterized in an antigen-capture-elisa with a panel of neutralizing monoclonal antibodies (mabs), and by nucleotide sequencing of the vp2 variable domain (vvp2). the viruses were compared with reference ibdv strains, among others with faragher 52/70 (f52/70, classical, isolated 1970), 89163 (typical very virulent-vvibdv, isolated 1989) and 91168 ... | 2004 | 14991437 |
| partial protection against infectious bursal disease virus through dna-mediated vaccination with the vp2 capsid protein and chicken il-2 genes. | several dna vaccination experiments were performed to determine the protective capability of a plasmid dna molecule encoding the vp2 capsid protein gene of infectious bursal disease virus (ibdv) injected into chickens in the presence or absence of chicken interleukin 2 (il-2) plasmid dna. the results of these experiments indicate that partial protection against ibdv can be achieved by using the vp2 gene of ibdv as a dna vaccine. furthermore, the simultaneous injection of chicken il-2 plasmid dna ... | 2004 | 15003654 |
| the last c-terminal residue of vp3, glutamic acid 257, controls capsid assembly of infectious bursal disease virus. | infectious bursal disease virus (ibdv) is a nonenveloped virus with an icosahedral capsid composed of two proteins, vp2 and vp3, that derive from the processing of the polyprotein nh(2)-pvp2-vp4-vp3-cooh. the virion contains vp1, the viral polymerase, which is both free and covalently linked to the two double-stranded rna (dsrna) genomic segments. in this study, the virus assembly process was studied further with the baculovirus expression system. while expression of the wild-type polyprotein wa ... | 2004 | 15016850 |
| high sequence diversity in infectious bursal disease virus serotype 1 in poultry and turkey suggests west-african origin of very virulent strains. | fifty-eight outbreaks of infectious bursal disease virus (ibdv) were observed in vaccinated chicken flocks in four southwestern states of nigeria between 1995 and 2000. bursa samples from 40 flocks were found virus-positive in vp2-specific nested rt-pcr. sequences of the hypervariable region of vp2 were compared to reference strains of the different ibdv variants including also 1988 isolates from nigeria. sequence analysis revealed that all 40 nigerian isolates belonged to the very virulent (vv) ... | 2004 | 15045556 |
| avian adenovirus celo recombinants expressing vp2 of infectious bursal disease virus induce protection against bursal disease in chickens. | to develop a celo virus vector that can induce protection against infectious bursal disease, celo viruses expressing the host-protective antigen vp2 of infectious bursal disease virus (ibdv) were constructed. in the engineered recombinants, the vp2 gene (the 441-first codons of the ibda polyprotein) was placed under the control of the cmv promoter. two positions in the celo genome were chosen to insert the vp2 expression cassette. the recombinants were found apathogenic, when inoculated by diffe ... | 2004 | 15149796 |
| a serological survey for pathogens in old fancy chicken breeds in central and eastern part of the netherlands. | to get an impression of the presence of pathogens in multi-aged flocks of old fancy chicken breeds in the netherlands, plasma samples originating from 24 flocks were examined for antibodies against 17 chicken pathogens. these flocks were housed mainly in the centre and east of the netherlands, regions with a high poultry density. the owners of the tested flocks showed their chicken at national and international poultry exhibitions. antibodies against avian influenza, egg drop syndrome '76 virus, ... | 2004 | 15185615 |
| protection against very virulent infectious bursal disease virus in chickens immunized with dna vaccines. | plasmid dna vaccines pcdna-vp2 expressing only vp2 protein and pcdna-vp243 expressing vp2, vp4 and vp3 proteins of very virulent infectious bursal disease virus (vvibdv) korean sh/92 strain were constructed. the expression of viral proteins from constructed dna vaccines was confirmed by an in vitro transcription/translation system and transfection in cos-7 cells. to investigate the protective efficacy of these dna vaccines, 2-week-old chickens were injected intramuscularly and intraperitoneally ... | 2004 | 15201032 |
| influence of early or late start of first feeding on growth and immune phenotype of broilers. | 1. the changes in body weight (bw) gain, immune phenotype and viability of commercial broilers, either given feed and water immediately after hatch or food-deprived for 24 or 48 h, were analysed in order to study the effect of early or late start of first feeding. 2. chickens fed immediately had a 6.1% higher bw at slaughter age than those food-deprived for 48 h, while those chickens food-deprived for 24 h only had a 1.4% higher weight than those deprived for 48 h. 3. those fed immediately and t ... | 2004 | 15222418 |
| rapid serological profiling by an immunocomb-based dot-enzyme-linked immunosorbent test for three major poultry diseases. | an immunocomb-based dot-elisa, employing specially designed apparatus, was used to measure the antibody status for the three major poultry diseases--newcastle disease, infectious bursal disease and infectious bronchitis--in single test sera. positive samples could be classified into strong, moderate and weak positives by comparison with the colour reaction given by known strong and weak positive serum controls. the simultaneous dot-immunobinding assay gave reproducible results and allowed consid ... | 2004 | 15222738 |
| very virulent infectious bursal disease virus in egypt: epidemiology, isolation and immunogenicity of classic vaccine. | infectious bursal disease (ibd) is still a significant threat facing the egyptian poultry industry. in this study, eight very virulent ibd viruses (vvibdv), originating from acute ibd outbreaks recorded in lower and upper egypt, were studied with respect to their ability to replicate in cell culture, antigenicity and immunogenicity of classic vaccine. six continuous cell lines and one primary cell culture were tested for replication of the vvibdvs. none of the vvibdv isolates could be adapted to ... | 2004 | 15222739 |
| comparison of in ovo and post-hatch vaccination with particular reference to infectious bursal disease. a review. | in ovo vaccination is an alternative approach to post-hatch vaccination of chickens, particularly in broilers. vaccination at embryonation day 18 helps to 'close the window' of susceptibility i.e. the time between vaccination and early exposure to infectious agents compared with post-hatch vaccination. attempts on embryonal vaccination as a mode of vaccine delivery were approached from the observation that chickens already develop certain immunologic functions before hatching. the immune system ... | 2004 | 15230052 |
| detection of infectious bursal disease virus by elisa using an antipeptide antibody raised against vp3 region. | antigenic determinant analysis was carried out on vp3, one of major immunogenic proteins of infectious bursal disease virus (ibdv) using computer algorithms. altogether 17 peptides were synthesized for predicted putative regions and were tested for their reactivity with ibdv-positive polyclonal sera as well as with antisera to other common avian viruses to confirm specificity and to rule out cross reactivity. of 17 peptides tested, three were selected and synthesized in multiple antigenic peptid ... | 2004 | 15230474 |
| sequence analysis of the variable vp2 gene of infectious bursal disease viruses passaged in vero cells. | korean field infectious bursal disease viruses (ibdvs) were isolated from ibdv suspected commercial chickens. a previous study revealed that these ibdv field isolates were virulent or very virulent ibdvs. the isolates were passaged three times in the chorioallantoic membrane of specific-pathogen-free embryonated chicken eggs and four times in vero cells. after passage, viral rnas were isolated and purified to determine the genetic changes. the hypervariable regions of the vp2 gene were amplified ... | 2004 | 15266110 |
| expression of immunogenic vp2 protein of infectious bursal disease virus in arabidopsis thaliana. | vp2 protein is the major host-protective immunogen of infectious bursal disease virus (ibdv) of chickens. transgenic lines of arabidopsis thaliana expressing recombinant vp2 were developed. the vp2 gene of an ibdv antigenic variant e strain was isolated, amplified by rt-pcr and introduced into a plant expression vector, pe1857, having a strong promoter for plant expression. a resulting construct with a bar gene cassette for bialaphos selection in plant (rpe-vp2) was introduced into agrobacterium ... | 2004 | 15269548 |
| quantification of infectious bursal disease viral proteins 2 and 3 in inactivated vaccines as an indicator of serological response and measure of potency. | viral protein 2 and viral protein 3 (vp2 and vp3) were quantified in a series of inactivated infectious bursal disease oil emulsion vaccines using enzyme-linked immunosorbent assay, and the dependence of the serological response on vaccine antigen content was studied. large differences in antigen content, up to 50-fold, were found between vaccines. neutralizing antibody titres at 3 to 6 weeks after vaccination varied from 3 log2 to 16 log2. none of the vaccines induced an antibody titre equal to ... | 2004 | 15276978 |
| reversion of molecularly engineered, partially attenuated, very virulent infectious bursal disease virus during infection of commercial chickens. | a molecularly cloned, tissue culture-adapted infectious bursal disease virus (bd-3tc) was generated from a very virulent strain by the reverse genetics approach following site-directed mutagenesis (q253h and a284t in vp2). the pathogenicity of bd-3tc was tested in commercial chickens. the wild-type strain (bd-3wt) and the molecularly cloned parental strain (bd-3mc) were included for comparison. the subclinical course of the disease, with delayed and milder pathological lesions followed by quick ... | 2004 | 15276985 |
| dogs as potential carriers of infectious bursal disease virus. | in this study, the possibility that dogs could eventually be carriers of infectious bursal disease virus (ibdv) after having eaten (voluntarily or accidentally) ibdv-infected chicks has been evaluated. a single beagle dog was fed chicks infected by a very virulent ibdv strain (vvibdv). afterwards, the presence and viability of ibdv in the faeces was assessed. viable vvibdv was detected in the dog's faeces for 2 days after the initial ingestion, which indicates excretion of vvibdv. comparison by ... | 2004 | 15276989 |
| proventriculitis in broiler chickens: effects of immunosuppression. | proventriculitis in broilers causes carcass condemnation when swollen proventriculi tear during evisceration. the cause of this proventriculitis is unknown, but several infectious agents have been associated with it. one such agent, infectious bursal disease virus (ibdv), has been implicated as a cause of proventriculitis, but a direct effect of this virus on the proventriculus has not been proven. the role of ibdv in proventriculitis may be indirect as a result of its ability to cause immunosup ... | 2004 | 15283417 |
| effect of a variant infectious bursal disease virus (e/del) on salmonella typhimurium infection in commercial broiler chickens. | the effect of infectious bursal disease virus (ibdv) on salmonella typhimurium (st) infections in broilers was investigated in terms of salmonella shedding and persistence, pathogenicity, and isotype specific humoral immune responses. thirty-six, 1-day-old, straight-run commercial broiler chickens that were salmonella negative by polymerase chain reaction (pcr) and culture were divided into two groups of 18 chicks each (st and st-ibdv). one group (st-ibdv) of chicks received the e/del strain of ... | 2004 | 15283423 |
| pathogenicity and molecular analysis of an infectious bursal disease virus isolated from malaysian village chickens. | the characteristics of the pathogenic infectious bursal disease virus (ibdv) that infected avian species other than commercial chickens were largely unknown. in this study, by using in vivo and molecular methods, we had characterized an ibdv isolate (named 94268) isolated from an infectious bursal disease (ibd) outbreak in malaysian village chickens--the adulterated descendant of the southeast asian jungle fowl (gallus bankiva) that were commonly reared in the backyard. the 94268 isolate was gro ... | 2004 | 15283430 |
| infectious bursal disease virus polyprotein expression arrests growth and mitogenic stimulation of b lymphocytes. | infectious bursal disease virus (ibdv) causes lymphocytolysis and immunosuppression in infected poultry. the ibdv genome encodes a polyprotein vp243 that is post-translationally cleaved by the vp4 protease into the two structural proteins pvp2 and vp3. the objective of the present study was to determine if ibdv polyprotein induced suppression of bursal b lymphocyte growth and their capacity for proliferation. bursal b cells were examined both for chickens infected with ibdv and for chickens oral ... | 2004 | 15290373 |
| development of a multiplex pcr for detection of avian adenovirus, avian reovirus, infectious bursal disease virus, and chicken anemia virus. | a multiplex polymerase chain reaction (mpcr) was developed and optimized for the simultaneous detection and differentiation of avian reovirus (arv), avian adenovirus group i (aav-i), infectious bursal disease virus (ibdv), and chicken anemia virus (cav). four sets of specific oligonucleotide primers were used in this test for arv, aav-i, ibdv, and cav. the mpcr dna products were visualized by gel electrophoresis and consisted of fragments of 365 bp for ibdv, 421 bp for aav-i, 532 bp for arv, and ... | 2004 | 15294316 |
| generation of serotype 1/serotype 2 reassortant viruses of the infectious bursal disease virus and their investigation in vitro and in vivo. | infectious bursal disease virus (ibdv) is the causative agent of acute or immunosuppressive disease in chickens. serotype 1 strains are pathogenic whereas serotype 2 strains neither cause disease nor protect against infection with the serotype 1 strains. the target organ of serotype 1 strains is the bursa fabricii (bf). the molecular determinants of this tropism, and therefore pathogenicity, are poorly understood. ibdv is a non-enveloped icosahedral virus particle of 60 nm in diameter, which con ... | 2004 | 15325078 |
| comparative analysis of viral rna and apoptotic cells in bursae following infection with infectious bursal disease virus. | specific-pathogen-free (spf) chickens infected with very virulent (vv) infectious bursal disease virus (ibdv) upm94/273 developed lower pathogenicity compared to upm97/61. sequence analysis indicated that upm94/273 is an exceptional vvibdv. in this study, a sybr green i based real-time reverse transcriptase reaction assay was developed to measure viral rna in the bursae of spf chickens infected with ibdv. specificity of the amplified products was confirmed by melting temperature analysis. a line ... | 2004 | 15325516 |
| a recombinant newcastle disease virus (ndv) expressing vp2 protein of infectious bursal disease virus (ibdv) protects against ndv and ibdv. | infectious bursal disease virus (ibdv) causes a highly immunosuppressive disease in chickens. currently available, live ibdv vaccines can lead to generation of variant viruses. we have developed an alternative vaccine that will not create variant ibdv. by using the reverse genetics approach, we devised a recombinant newcastle disease virus (ndv) vector from a commonly used vaccine strain lasota to express the host-protective immunogen vp2 of a variant ibdv strain gls-5. the gene encoding the vp2 ... | 2004 | 15331738 |
| extensive antigenic changes in an atypical isolate of very virulent infectious bursal disease virus and experimental clinical control of this virus with an antigenically classical live vaccine. | the 99323 egyptian isolate of infectious bursal disease (ibd) virus (ibdv) was identified during an international survey of acute ibd cases. its unique antigenicity was characterized by a markedly reduced binding of neutralizing monoclonal antibodies 3, 4, 5, 6, 8 and 9 in an antigen-capture enzyme-linked immunosorbent assay. nucleotide sequencing of the genome region encoding the vp2 major immunogenic domain in 99323 revealed amino acid changes occurring at positions critical for antigenicity, ... | 2004 | 15370040 |
| characterization of particles formed by the precursor protein vpx of infectious bursal disease virus in insect hi-5 cells: implication on its proteolytic processing. | the precursor (vpx) of host immunogen vp2 protein for infectious bursal disease virus (ibdv) was expressed in insect sf9 and hi-5 cells, and the types of particles generated as well as the immunogenicity induced by these particles were examined. recombinant vpxh (rvpxh) protein, expressed in hi-5 cells at an expression level 4x higher than in sf9 cells, was efficiently processed by proteases to yield vp2-like proteins with corresponding molecular weight, a phenomenon not observed previously. at ... | 2004 | 15381356 |
| molecular characterization of an infectious bursal disease virus isolate from iran. | the segment a of an infectious bursal disease virus (ibdv) isolate from iran was amplified by reverse transcription-polymerase chain reaction (rt-pcr), sequenced and compared with published sequences of 26 ibdv isolates from other parts of the world. the iranian isolate showed 8 unique amino acid differences. in addition, 9 common amino acid differences, namely 3 in vp2, (222 ala, 256 lie and 294 lie), 3 in vp4 (685 asn/ser, 715 ser and 751 asp), 2 in vp3 (990 val and 1005 ala), and 1 in vp5 (49 ... | 2004 | 15462282 |
| enhancement of the immunogenicity of dna vaccine against infectious bursal disease virus by co-delivery with plasmid encoding chicken interleukin 2. | the immunoregulatory activity of a nonmammalian interleukin 2 (il-2), chicken il-2 (chil-2), was investigated using a dna vaccine against infectious bursal disease virus (ibdv) as a model. coadministration of a plasmid encoding the vp2 gene of ibdv (pci-vp2) and a plasmid encoding chicken il-2 gene (pci-chil-2) enhances bursal protection against both the homologous ibdv strain zj2000 and the heterologous strain bc6/85 compared to administration of pci-vp2 alone. vaccination with pci-vp2 alone in ... | 2004 | 15476877 |
| vp1, the rna-dependent rna polymerase and genome-linked protein of infectious bursal disease virus, interacts with the carboxy-terminal domain of translational eukaryotic initiation factor 4aii. | infectious bursal disease virus (ibdv), a member of the family birnaviridae, is a non-enveloped, double-stranded rna virus. viral protein 1 (vp1), the putative rna-dependent rna polymerase, occurs in virions both as a free polypeptide and as a genome-linked protein, called vpg. to gain more insight in its function, we initiated a yeast two-hybrid screen. with this approach we identified the carboxy-terminal domain of eukaryotic translation initiation factor 4aii (eif4aii) as an interactor for vp ... | 2004 | 15503210 |
| vp1 protein of infectious bursal disease virus modulates the virulence in vivo. | infectious bursal disease viruses (ibdvs), belonging to the birnaviridae family, cause severe immunodeficiency in young chickens by destroying the precursors of antibody-producing b cells in the bursa of fabricius (bf). different pathotypes of ibdvs, including cell culture-adapted viruses, differ markedly in virulence, which is characterized by mortality and bursal damage. to study the molecular determinants of virulence in ibdv, the genomic segments a and b of gls bursa-derived (glsbd) and tiss ... | 2004 | 15527834 |
| genetic characterization of very virulent infectious bursal disease viruses from latin america. | very virulent infectious bursal disease viruses (vvibdvs) were detected in phenol inactivated bursal samples obtained from brazil, the dominican republic, and venezuela. after nucleotide sequence analysis of the hypervariable region of vp2 gene, the vvibdvs from brazil and venezuela exhibited all of the 14 nucleotide changes that are conserved in the european uk-661 and most other vvibdv strains. however, the vvibdv from the dominican republic presented 11 nucleotide changes that are conserved i ... | 2004 | 15529976 |
| immunization of chickens with vp2 protein of infectious bursal disease virus expressed in arabidopsis thaliana. | transgenic plants represent a safe, effective, and inexpensive way to produce vaccines. the immunogenicity of vp2 protein of an infectious bursal disease (ibd) virus variant e isolate expressed in transgenic arabidopsis thaliana was compared with a commercial vaccine in specific-pathogen-free broiler chickens. the vp2 coding sequence was isolated and integrated into a. thaliana genome by agrobacterium tumefaciens-mediated transformation. soluble vp2 expressed in transgenic plants was used to imm ... | 2004 | 15529992 |
| use of multiple antigenic peptides related to antigenic determinants of infectious bursal disease virus (ibdv) for detection of anti-ibdv-specific antibody in elisa--quantitative comparison with native antigen for their use in serodiagnosis. | multiple antigenic peptides (maps) prepared for the predicted antigenic determinants on the vp2 protein of infectious bursal disease virus (ibdv) were used as antigens in enzyme-linked immunosorbent assay (elisa)--an alternative to whole viral antigen to detect anti-ibdv antibodies in the chicken sera. two maps were synthesized, which could specifically detect the anti-ibdv antibodies in serum samples by elisa. the optimum quantity of map1 and map2 required to coat the wells of the elisa plate w ... | 2004 | 15541277 |
| assessment of genetic, antigenic and pathotypic criteria for the characterization of ibdv strains. | the aim of this work was the selection and comparison of representative infectious bursal disease virus (ibdv) strains. nine strains of ibdv, isolated at different times and from different geographic regions of europe and china, were characterized. batches of all strains were prepared following standardized protocols and checked for the absence of contaminating viruses. criteria used for their characterization were: (i) the nucleotide sequence of the vp2 variable region, (ii) binding to a panel ... | 2004 | 15545026 |
| spontaneous colibacillosis in infectious bursal disease-affected broiler flocks. | 2004 | 15563022 | |
| sequence analysis of an indian field isolate of infectious bursal disease virus shows six unique amino acid changes in the vp1 gene. | 2004 | 15563111 | |
| infiltration by cd4+ and cd8+ lymphocytes in bursa of chickens infected with infectious bursal disease virus (ibdv): strain-specific differences. | in order to investigate if there is any definite correlation between the degree of t-cell response in the bursa of fabricius (bf) and the virulence of infectious bursal disease (ibd) virus strains, chickens were infected with strains of different virulence i.e. mild (lukert strain), intermediate (georgia strain) or invasive intermediate (iv-95 strain). at various times post-inoculation, bursal samples were collected to study virus specific histopathological lesions, the distribution of viral ant ... | 2004 | 15573535 |
| evaluation of immunosuppressants and dietary mechanisms in an experimental disease model for necrotic enteritis. | clostridium perfringens (cp) is the etiologic agent of necrotic enteritis (ne). clinical signs of this disease include depression, decreased appetite, diarrhea, and severe necrosis of the intestinal tract. understanding the disease progression of ne has been difficult due to its complexity and the involvement of multiple factors (dietary components, immunosuppression, and mechanical irritation of the gut) that appear to contribute to this syndrome. in the present investigation, day-of-hatch broi ... | 2004 | 15615005 |
| the c-terminal domain of the pvp2 precursor is essential for the interaction between vp2 and vp3, the capsid polypeptides of infectious bursal disease virus. | the interaction between the infectious bursal disease virus (ibdv) capsid proteins vp2 and vp3 has been analyzed in vivo using baculovirus expression vectors. data presented here demonstrate that the 71-amino acid c-terminal-specific domain of pvp2, the vp2 precursor, is essential for the establishment of the vp2-vp3 interaction. additionally, we show that coexpression of the pvp2 and vp3 polypeptides from independent genes results in the assembly of virus-like particles (vlps). this observation ... | 2004 | 15063123 |
| peptides resulting from the pvp2 c-terminal processing are present in infectious pancreatic necrosis virus particles. | the capsid of birnaviruses contains two proteins, vp2 and vp3, which derive from the processing of a large polyprotein, nh(2)-pvp2-vp4-vp3-cooh. the proteolytic cascade involved in processing the polyprotein, and in the final maturation of pvp2 (the precursor of vp2), has recently been shown to generate vp2 and four structural peptides in infectious bursal disease virus and blotched snakehead virus. the presence of peptides in infectious pancreatic necrosis virus particles was investigated using ... | 2004 | 15269363 |
| vp1 of infectious bursal disease virus is an rna-dependent rna polymerase. | segment b of the bisegmented, double-stranded rna genome of infectious bursal disease virus (ibdv) encodes the viral protein vp1. this has been presumed to represent the rna-dependent rna polymerase (rdrp) as it contains motifs that are typical for the rdrp of plus-strand rna viruses. here it is demonstrated that baculovirus-expressed wild-type but not motif a mutated vp1 acts as an rdrp on ibdv-specific rna templates. thus, on a plus-strand ibdv segment a crna template, minus-strand synthesis o ... | 2004 | 15269362 |
| recent trends in the molecular diagnosis of infectious bursal disease viruses. | infectious bursal disease virus (ibdv) causes an immunosuppressive disease in young chickens. two serotypes of this double-stranded rna virus exist but only serotype 1 viruses cause disease in chickens. detection and strain identification of ibdv is important because antigenic subtypes found within serotype 1 make it necessary to tailor vaccination programs to the antigenic type found in the bird's environment. because conventional virus isolation and characterization are not practical for routi ... | 2004 | 15984346 |
| control of infectious bursal disease virus by vaccination. | in summary, the currently used conventional vaccines are used effectively to control the disease. the promise of the new generation of vaccines has not materialized yet. this is partly due to the incomplete understanding of the molecular basis of immunogenicity resulting in an inadequate immune response. it should be emphasized that rna viruses such as ibdv are prone to change through a variety of mechanisms. this requires vigilance in monitoring field viruses and the natural history of the dise ... | 2004 | 15742625 |
| modifications of the 3'-utr stem-loop of infectious bursal disease virus are allowed without influencing replication or virulence. | many questions regarding the initiation of replication and translation of the segmented, double-stranded rna genome of infectious bursal disease virus (ibdv) remain to be solved. computer analysis shows that the non-polyadenylated extreme 3'-untranslated regions (utrs) of the coding strand of both genomic segments are able to fold into a single stem-loop structure. to assess the determinants for a functional 3'-utr, we mutagenized the 3'-utr stem-loop structure of the b-segment. rescue of infect ... | 2004 | 14718548 |