Publications
| Title | Abstract | Year(sorted ascending) Filter | PMID Filter |
|---|
| research on infectious bursal disease--the past, the present and the future. | infectious bursal disease (ibd) virus (ibdv) is the etiological agent of "gumboro disease". although first observed about 40 years ago, this disease continues to pose an important threat to the commercial poultry industry. the emergence of antigenic variant as well as very virulent strains in vaccinated flocks considerably stimulated research efforts on both, ibd and ibdv. in this review, some of the recent advances in the understanding of the structure, morphogenesis and molecular biology of th ... | 2003 | 14637046 |
| generation of chicken single chain antibody variable fragments (scfv) that differentiate and neutralize infectious bursal disease virus (ibdv). | phage-displayed recombinant antibody libraries derived from splenic mrna of chickens immunized with an australian strain of infectious bursal disease virus (ibdv) were constructed as single chain variable fragments (scfv) by either overlap extension polymerase chain reaction (pcr) or sequential ligation of the individual heavy (v(h)) and light (v(l)) chain variable gene segments. sequential cloning of the individual v(h) and v(l) genes into a newly constructed pcantab-link vector containing the ... | 2003 | 12607101 |
| the immunologists' debt to the chicken. | the immune system of the chicken is an invaluable model for studying basic immunology and has made seminal contributions to fundamental immunological principles. graft versus host responses and the key role of lymphocytes in adaptive immunity were first described in work with chicken embryos and chickens. 2. most notably, the bursa of fabricius provided the first substantive evidence that there are two major lineages of lymphocytes. bursa-derived lymphocytes, or b cells, make antibodies while th ... | 2003 | 12737220 |
| isolates of infectious bursal disease virus from india are of very virulent phenotype. | four indian field isolates, a classical virulent and an attenuated vaccine strains of infectious bursal disease virus (ibdv) have been characterized by sequence analysis of part of the vp1 gene (from nucleotide 1538-1979) comprising one of viral rna dependent rna polymerase motifs. sequence alignment of these viruses with reported viruses of other countries revealed indian ibdv field isolates to be 100% similar to very virulent japanese (okym), european (uk661) and bangladesh (bd3/99) ibd viruse ... | 2003 | 14658846 |
| characterization of the rna-binding activity of vp3, a major structural protein of infectious bursal disease virus. | infectious bursal disease virus (ibdv) is the agent of an immune-depressive disease affecting the poultry industry worldwide. infection of ibdv leads to expression of five mature virus-encoded proteins. proteolytic processing of the virus-encoded polyprotein generates vp3 which coats the inner surface of the ibdv capsid. in this report, we describe the characterization of the rna-binding activity of vp3. for these studies, the vp3 coding region was fused to a histidine tag and expressed in insec ... | 2003 | 12664296 |
| sequence and analysis of genomic segment a and b of very virulent infectious bursal disease virus isolated from china. | a very virulent infectious bursal disease virus (vvibdv) field strain, named sh95, was identified and characterized from flocks with vaccination failure in shanghai. the use of random primer and a reverse transcriptase lacking rnase-h activity produced full-length cdna copies of the viral genomic a and b segments of sh95. the 3259 base pairs (bp) of segment a and 2827 bp of segment b were amplified by long and accurate pcr in a single step, then successfully cloned and sequenced. there were five ... | 2003 | 12667193 |
| identification of crucial residues of conformational epitopes on vp2 protein of infectious bursal disease virus by phage display. | a new method for identifying epitopes in viral proteins expressed by filamentous phage has been developed. filamentous phage fuse 1 containing the variable region of the vp2 gene of infectious bursal disease virus (ibdv) strain 002-73 was constructed. neutralizing monoclonal antibodies 17-82 and 33-10 raised against vp2 protein were used to bind phage containing the original variable region of vp2. the phage bound to monoclonal antibodies, were removed by protein g sepharose and the unbound phag ... | 2003 | 12668271 |
| [rapid construction of infectious clones of infectious bursal disease virus]. | a rapid procedure was established for rescuing infectious bursal disease virus (ibdv), an important pathogen in poultry. a full-length cdna clone of the segment b of a cef-adapted ibdv strain hz2 was constructed by long rt-pcr, and the 2827 bp nucleotide sequence, including the 5 - and 3 -noncoding regions (ncr), was established. then the cdna clone of segment b was engineered to make it contain three silent nucleotide changes, creating a new ecorv site that was different from the parent virus s ... | 2003 | 12673387 |
| cloning and nucleotide analysis of segment a gene of infectious bursal disease virus detected in korea. | a strain of infectious bursal disease virus (ibdv) was detected from bursal tissues of chicks which suffered from infectious bursal disease (ibd) in chinju, korea and provisionally named as chinju strain. a full-length cdna clone for segment a gene of the virus was constructed, and complete nucleotide sequence of the gene including noncoding region was determined and analyzed by comparison with that of other ibdv strains. the segment a gene of chinju strain consisted of 3,269 nucleotides includi ... | 2003 | 12680697 |
| structure-dependent efficacy of infectious bursal disease virus (ibdv) recombinant vaccines. | the immunogenicity and protective capability of several baculovirus-expressed infectious bursal disease virus (ibdv)-derived assemblies as vp2 capsids, vpx tubules and polyprotein (pp)-derived mixed structures, were tested. four-week-old chickens were immunised subcutaneously with one dose of each particulate antigen. vp2 icosahedral capsids induced the highest neutralising response, followed by pp-derived structures and then vpx tubules. all vaccinated animals were protected when challenged wit ... | 2003 | 12706682 |
| differentiation of infectious bursal disease viruses isolated in croatia. | infectious bursal disease viruses (ibdvs) in 26 ibdv-positive bursa samples collected in croatia during the period 1996-2000 and in two commercially available vaccines were differentiated by the presence or absence of the cfoi, saci, sspi, stui, and taqi restriction sites in the 422-bp fragment of segment a of the vp2 gene (nt 732-1153). the fragments from 14 (54%) field isolates were taqi+ stui+ sspi+ and saci- cfoi-, indicating their very virulent (vv) character. the presence of cfoi restricti ... | 2003 | 12713159 |
| comparative immunopathogenesis of mild, intermediate, and virulent strains of classic infectious bursal disease virus. | differences in the immunopathogenesis of several strains of infectious bursal disease virus (ibdv) were compared. the strains included a virulent virus (ibdv-im) and three vaccine viruses that included an intermediate vaccine virus (ibdv-b2) and two mild vaccine viruses (ibdv-lukert and ibdv-bvm). the most significant differences were found in the systemic effects of these strains. in comparison with other strains, ibdv-im antigen was detectable for up to 8 days postinfection (pi) in lymphoid ti ... | 2003 | 12713160 |
| the oligomerization domain of vp3, the scaffolding protein of infectious bursal disease virus, plays a critical role in capsid assembly. | infectious bursal disease virus (ibdv) capsids are formed by a single protein layer containing three polypeptides, pvp2, vp2, and vp3. here, we show that the vp3 protein synthesized in insect cells, either after expression of the complete polyprotein or from a vp3 gene construct, is proteolytically degraded, leading to the accumulation of product lacking the 13 c-terminal residues. this finding led to identification of the vp3 oligomerization domain within a 24-amino-acid stretch near the c-term ... | 2003 | 12743301 |
| dna vaccination with plasmids containing various fragments of large segment genome of infectious bursal disease virus. | the present study was undertaken to determine the effectiveness in including vp2 gene of the large segment genome of infectious bursal disease virus (ibdv) in the dna vaccine for protection of chickens against infectious bursal disease (ibd). different fragments of the large segment gene of ibdv standard challenge (stc) strain were successfully amplified by reverse transcription-polymerase chain reaction (rt-pcr) followed by cloning into a eukaryotic expression plasmid vector (pcr3.1) as dna vac ... | 2003 | 12531650 |
| identification and molecular characterization of the rna polymerase-binding motif of infectious bursal disease virus inner capsid protein vp3. | infectious bursal disease virus (ibdv), a member of the birnaviridae family, is the causative agent of one of the most important infectious poultry diseases. major aspects of the molecular biology of ibdv, such as assembly and replication, are as yet poorly understood. we have previously shown that encapsidation of the putative virus-encoded rna-dependent rna polymerase vp1 is mediated by its interaction with the inner capsid protein vp3. here, we report the characterization of the vp1-vp3 inter ... | 2003 | 12551984 |
| very virulent infectious bursal disease virus in southeastern europe. | clinical outbreaks of severe acute infectious burial disease (ibd) were recorded since the mid- and late 1990s in several countries in the southeastern part of europe. epidemiologic data showed that both infectious bursal disease virus (ibdv)-vaccinated and ibdv-nonvaccinated chickens were affected with acute ibd and mortality up to 50% independent of the ibdv vaccination status of the appropriate parent flocks. for investigation of the causative agent of acute ibd, the variable region of vp2 wa ... | 2003 | 12713176 |
| sequence analysis of segment a of a field virus isolate from an outbreak of infectious bursal disease in india. | sequence analysis of genome segment a of an indian infectious bursal disease virus (ibdv) field isolate (kt1/99) revealed total 95 nucleotide substitutions, resulting in 17 amino acid changes. of these, five amino acid changes, namely f60s, t137i, i374v, v519i and e682d were unique to the kt1/99 isolate. the amino acid change p222a and the proposed hot mutation spot 680y, reported to be present in very virulent ibdv isolates were also found in kt1/99. this isolate had nucleotide divergence of 1. ... | 2003 | 14524472 |
| blotched snakehead virus is a new aquatic birnavirus that is slightly more related to avibirnavirus than to aquabirnavirus. | by different approaches, we characterized the birnavirus blotched snakehead virus (bsnv). the sequence of genomic segment a revealed the presence of two open reading frames (orfs): a large orf with a 3,207-bp-long nucleotide sequence and a 417-nucleotide-long small orf located within the n-terminal half of the large orf, but in a different reading frame. the large orf was found to encode a polyprotein cotranslationally processed by the viral protease vp4 to generate pvp2 (the vp2 precursor), a 7 ... | 2003 | 12477876 |
| ability of lactococcus lactis to export viral capsid antigens: a crucial step for development of live vaccines. | the food grade bacterium lactococcus lactis is a potential vehicle for protein delivery in the gastrointestinal tract. as a model, we constructed lactococcal strains producing antigens of infectious bursal disease virus (ibdv). ibdv infects chickens and causes depletion of b-lymphoid cells in the bursa of fabricius and subsequent immunosuppression, morbidity, or acute mortality. the two major ibdv antigens, i.e., vp2 and vp3, that form the viral capsid were expressed and targeted to the cytoplas ... | 2003 | 14660377 |
| protection from infectious bursal disease virus (ibdv)-induced immunosuppression by immunization with a fowlpox recombinant containing ibdv-vp2. | immunosuppression resulting from infectious bursal disease virus (ibdv) infection has critical health and welfare implications for birds, yet it is incompletely understood and largely overlooked as a measure of vaccine efficacy. the ability of a fowlpoxvirus recombinant (fpibd1) containing the vp2 protein of ibdv to protect against ibdv-induced immunosuppression was investigated by measuring the convalescent chicken's ability to mount antibody responses to ibdv infection, and to inactivated ibdv ... | 2003 | 14676010 |
| characterization of egyptian field strains of infectious bursal disease virus. | the reverse transcriptase-polymerase chain reaction/restriction fragment length polymorphism (rt-pcr/rflp) technique was used for identification and characterization of egyptian field strains of infectious bursal disease viruses (ibdvs) that caused severe outbreaks with (30%-60%) mortality rate. twenty-four bursal samples collected from 24 field outbreaks in commercially reared chicken flocks experiencing signs typical of infectious bursal disease (ibd) were used. ten of the bursal samples exami ... | 2003 | 14708996 |
| sequence analysis of infectious bursal disease virus isolates from india: phylogenetic relationships. | prevalence of infectious bursal disease (ibd) among chickens in different parts of tamil nadu, india, has been studied by collection of bursal samples from suspected flocks and by performing reverse transcription-polymerase chain reaction (rt-pcr) for amplification of a specific product of 474 bp from the variable region of the vp2 gene. among 53 bursal samples examined by rt-pcr, 40 showed a positive reaction. the amplified products were subjected to nucleotide sequencing and the obtained seque ... | 2003 | 14658839 |
| efficacy of dna vaccines against infectious bursal disease virus in chickens enhanced by coadministration with cpg oligodeoxynucleotide. | the objective of the present study was to investigate the feasibility of a dna vaccine and cpg oligodeoxynucleotide (odn) to protect chickens against infectious bursal disease virus (ibdv) infection. two plasmids dna carrying vp2 genes of the very virulent (vv) strain of ibdv were constructed with reverse transcription-polymerase chain reaction and designated as pcdna3.1-vp2 and pci-vp2. the vp2 protein expressed in cos-7 cells transfected with the plasmid was confirmed by indirect immunofluores ... | 2003 | 14708976 |
| chicken anemia virus in broilers: dynamics of the infection in two commercial broiler flocks. | chicken anemia virus (cav) can cause a disease syndrome characterized by severe anemia, bone marrow atrophy, and severe immunosuppression in young chicks. maternal antibodies prevent these clinical signs but do not prevent infection, transmission of the virus, or immunosuppression. the clinical disease is rare today because of the widespread practice of vaccinating breeders, but the subclinical form of the disease is ubiquitous. the dynamics of cav infection, cav antibody responses, relative lym ... | 2003 | 14708998 |
| effects of early age feed restriction and heat conditioning on heat shock protein 70 expression, resistance to infectious bursal disease, and growth in male broiler chickens subjected to heat stress. | the effects of early age feed restriction and heat conditioning on heat shock protein (hsp) 70 expression, antibody production, resistance to infectious bursal disease (ibd), and growth of heat-stressed male broiler chickens were investigated. chicks were divided into 4 groups: 60% feed restriction on d 4,5, and 6 (fr); exposure to 36 +/- 1 degrees c for 1 h from d 1 to 21 (ht); combination of fr and ht (frht); and control. from d 35 to 50, heat stress was induced by exposing birds to 38 +/- 1 d ... | 2003 | 14717545 |
| efficacy of a recombinant vaccine hvt-vp2 against gumboro disease in the presence of maternal antibodies. | 2003 | 14965139 | |
| [establishment and biological properties of hybridoma cell lines secreting anti-ibdv idiotypic antibodies]. | in recent years, the prevention and cure of infectious bursal disease (ibd) have become more and more difficult due to the emergence of very virulent strains of infectious bursal disease virus (vvibdv) and the variant strains of ibdv. in this research, the hybridoma cell lines which secretes anti-idiotypic antibodies against anti-ibdv igg were established. according to the jerne's theory of immune network, the use of the anti-idiotypic antibodies as a vaccine will be a new method for the prevent ... | 2003 | 15969065 |
| [expression of the infectious bursal disease virus polyprotein in vero cells using attenuated salmonella typhimurium as transgenic carrier]. | to examine if polyprotein gene (vp2/vp4/vp3) of infectious bursal disease virus (ibdv) could be delivered into mammalian cells and expressed using attenuated salmonella typhimurium as vector. the ibdv polyprotein gene was amplified by rt-pcr and inserted in to pci, an eukaryotic expression plasmid. the resulting recombinant pci-vp2/vp4/vp3 was transformed by electroporation into attenuated salmonella typhimurium strain zj111 (dam- and phop-), which was then use to transfect the vero cells. gene ... | 2004 | 15971620 |
| 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 |
| 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 |
| examination of the value of treatment of decompensated viral hepatitis patients by intentionally coinfecting them with an apathogenic ibdv and using the lessons learnt to seriously consider treating patients infected with hiv using the apathogenic hepatitis g virus. | hepatitis virus infection persistent worldwide (approximately 600 m people) results in chronic hepatitis progressing to hepatocellular carcinoma (hcc) in many (approximately 1 m deaths/year). the review examines the usefulness of treating chronic viral hepatitis, including decompensated patients, by intentional coinfection with an attenuated infectious bursal disease virus (ibdv; apathogenic in man, stable at ph 2, orally administered). learning lessons from the ibdv studies, the case is made to ... | 2004 | 15519701 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| base usage and dinucleotide frequency of infectious bursal disease virus. | base usage and dinucleotide frequency have been extensively studied in many eukaryotic organisms and bacteria, but not for viruses. in this paper, a comprehensive analysis of these aspects for infectious bursal disease virus (ibdv) was presented. the analysis of base usage indicated that all of the ibdv genes possess equivalent overall nucleotide distributions. however when the base usage at each codon positions was analysed by using cluster analysis, the vp5 open reading frame (orf) formed a di ... | 2004 | 14739650 |
| sequence analysis of both genome segments of two very virulent infectious bursal disease virus field isolates with distinct pathogenicity. | the deduced amino acid sequences of segment a and b of two very virulent infectious bursal disease virus (vvibdv) isolates, upm94/273 and upm97/61 were compared with 25 other ibdv strains. twenty amino acid residues (8 in vp1, 5 in vp2, 2 in vp3, 4 in vp4, 1 in vp5) that were common to vvibdv strains were detected. however, upm94/273 is an exceptional vvibdv with usual amino acid substitutions. the differences in the divergence of segment a and b indicated that the vvibdv strains may have been d ... | 2004 | 14745606 |
| 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 |
| 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 |
| 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 | |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| history of biological control of poultry diseases in the usa. | 2004 | 15077792 | |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| two outbreaks of very virulent infectious bursal disease virus in pakistan. | 2005 | 16361477 | |
| 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 |
| 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 |
| 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 |
| health evaluation of free-ranging and captive blue-fronted amazon parrots (amazona aestiva) in the gran chaco, bolivia. | bolivia has a total of 47 species of psittacidae, seven of which have been identified in our study site, the semiarid gran chaco of the isoso. one species, the blue-fronted parrot (amazona aestiva), is frequently captured by local isoseño guaraní indians for exploitation on the national and international market. these birds are often temporarily housed in small villages under unhygienic conditions with poultry and other domestic species. on occasion, these parrots escape back to the wild. additi ... | 2005 | 17312715 |
| 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 |