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crystallization and preliminary x-ray diffraction studies of infectious bronchitis virus nonstructural protein 9.avian infectious bronchitis virus (ibv), which causes respiratory disease in infected birds, belongs to coronavirus group 3. ibv encodes 15 nonstructural proteins (nsp2-nsp16) which play crucial roles in rna transcription and genome replication. nonstructural protein 9 (nsp9) has been identified as a protein that is essential to viral replication because of its single-stranded rna-binding ability. the gene segment encoding ibv nsp9 has been cloned and expressed in escherichia coli. the protein h ...201020516605
proteomic analysis of purified coronavirus infectious bronchitis virus particles.abstract:201020534109
differential sensitivity of well-differentiated avian respiratory epithelial cells to infection by different strains of infectious bronchitis virus.infectious bronchitis virus (ibv) is an avian coronavirus affecting the respiratory tract of chickens. to analyze ibv infection of the lower respiratory tract, we applied a technique that uses precision-cut lung slices (pclss). this method allows infection of bronchial cells within their natural tissue composition under in vitro conditions. we demonstrate that ibv strains 4/91, italy02, and qx infect ciliated and mucus-producing cells of the bronchial epithelium, whereas cells of the parabronchi ...201020538853
rapid heat-treatment attenuation of infectious bronchitis virus.in the present study we describe the rapid development of an attenuated live vaccine for ga08, a new serotype of infectious bronchitis virus, using a heat-treatment method. incubation of the ga08 strain of ibv at 56 degrees c and passage in embryonated eggs was used as a method to fast track the attenuation process. the virus was incubated in a 56 degrees c water bath and aliquots were removed every 5 min for up to 1 h, and then each aliquot was inoculated into 10-day-old embryonated eggs. virus ...201020544430
genetic analysis revealed lx4 genotype strains of avian infectious bronchitis virus became predominant in recent years in sichuan area, china.between 2008 and 2010, 19 strains of infectious bronchitis virus (ibv) were isolated from the vaccinated chicken flocks in sichuan province, china. the s1 genes of the isolates were amplified and sequenced. phylogenetic analysis revealed that the 19 isolates and 37 reference ibv strains can be grouped into eight genotypes. although ibvs of taiwan-i type, massachusetts type, and proventriculitis type were isolated, but most isolates were lx4 genotype. homology analysis of the sequences of s1 gene ...201020556502
comparative histopathology and immunohistochemistry of qx-like, massachusetts and 793/b serotypes of infectious bronchitis virus infection in chickens.the aim of this study was to compare experimentally the pathogenicity and tissue distribution of the recently emerged qx-like strain of infectious bronchitis virus (ibv) with the widespread m41 and 793/b serotypes of the virus. histopathological and immunohistochemical methods were employed to define the main sites of virus replication. one-day-old specific pathogen free chickens were inoculated with five different qx-like strains, or with the m41 and 793/b ibv strains and monitored for 42 days ...201020570279
the cellular rna helicase ddx1 interacts with coronavirus nonstructural protein 14 and enhances viral replication.the involvement of host proteins in the replication and transcription of viral rna is a poorly understood area for many rna viruses. for coronaviruses, it was long speculated that replication of the giant rna genome and transcription of multiple subgenomic mrna species by a unique discontinuous transcription mechanism may require host cofactors. to search for such cellular proteins, yeast two-hybrid screening was carried out by using the nonstructural protein 14 (nsp14) from the coronavirus infe ...201020573827
naturally occurring recombination between distant strains of infectious bronchitis virus.new variants of infectious bronchitis virus (ibv) have emerged in australia despite its geographical isolation and intensive vaccination programs. in the present study, the 3' terminal 7.2 kb of the genome of a recently isolated variant of ibv (n1/03) was sequenced and compared with the sequences of classical and novel strains of ibv, the two main groups of these viruses in australia. the comparison revealed that recombination between classical and novel ibvs was responsible for the emergence of ...201020574643
[expression and biological function analysis of chicken aminopeptidase n].to clone and express the gene encoding chicken aminopeptidase n (chapn), and analysis the biological function of chapn expressed in escherichia coli (e. coli). the chapn gene was amplified by rt-pcr from the kidney cells of chicken embryo and then cloned into the prokaryotic expression vector pcold-tf. recombinant expression plasmid of pcold-tf-chapn was constructed and then transformed into the competent e. coli bl21(de3) cells for expression under different conditions such as induction time an ...201020575434
analysis of newcastle disease virus quasispecies and factors affecting the emergence of virulent virus.genome sequence analysis of a number of avirulent field isolates of newcastle disease virus revealed the presence of viruses (within their quasispecies) that contained virulent f0 sequences. detection of these virulent sequences below the ~1% level, using standard cloning and sequence analysis, proved difficult, and thus a more sensitive reverse-transcription real-time pcr procedure was developed to detect both virulent and avirulent ndv f0 sequences. reverse-transcription real-time pcr analysis ...201020602243
host intraspatial selection of infectious bronchitis virus populations.arkansas (ark)-type infectious bronchitis virus (ibv) subpopulations with an s gene sequence distinct from the vaccine predominant consensus were previously found in the upper respiratory tract of chickens within 3 days after inoculation. this finding indicated that a distinct virus subpopulation was rapidly positively selected by the chicken upper respiratory tract. we hypothesized that during host invasion, the replicating ibv population further changes as it confronts the distinct environment ...201020608523
molecular epidemiology of avian infectious bronchitis in brazil from 2007 to 2008 in breeders, broilers, and layers.multiple lineages of brazilian strains from 2007 to 2008 of avian infectious bronchitis virus (ibv) were detected in flocks of breeders, broilers, and layers. organs samples from 20 ibv-positive flocks with variable clinical signs were submitted to the partial amplification of s gene (nucleotides 726-1071) of ibv. fifteen of the 20 sequenced strains segregated in a unique brazilian cluster subdivided in three subclusters (brazil 01, 02, and 03). whereas three strains could be classified as massa ...201020608535
treatment of eggshell abnormalities and reduced egg production caused by mycoplasma synoviae infection.eggshell abnormalities were seen in the apex of eggs in two of three flocks of multi-age, hy-line layer chickens housed on a farm in northern italy. approximately 1.3% to 1.8% of eggs in one flock were affected, amounting to 300-400 eggs per day; the abnormalities resulted in a great deal of breakage and spoilage of healthy eggs. the mean weight of eggs was also reduced. egg abnormalities in a second flock were less severe. mycoplasma synoviae was detected in birds from both of the affected floc ...201020608549
detection of infectious bronchitis virus strain n1/88 from the oviduct and feces of experimentally infected vaccinated and unvaccinated hens.hens were vaccinated during the rearing phase with infectious bronchitis virus (ibv) vaccines commercially available in australia (vic s and a3) or left unvaccinated and then challenged with the n1/88 strain of ibv at 30 wk of age. oviduct and fecal samples were collected at regular intervals after n1/88 challenge. a locked nucleic acid probe-based reverse transcription real-time pcr test was designed and used to detect the ibv strain n1/88 from the oviduct and feces of unvaccinated and vaccinat ...201020634513
complete genome sequence and recombination analysis of infectious bronchitis virus attenuated vaccine strain h120.the strain h120 of infectious bronchitis virus (ibv) is one of the earliest and representative attenuated live infectious bronchitis vaccine strains. to investigate the genomic feature of h120 and further understand its role in the epidemiology of ibv, complete genome of h120 was sequenced and compared with sequences of other ibv strains by phylogenetic and recombination analysis. the complete genome of h120 is 27631 nucleotides in length and has a similar structure with that of beaudette strain ...201020652731
coronavirus genomics and bioinformatics analysis.the drastic increase in the number of coronaviruses discovered and coronavirus genomes being sequenced have given us an unprecedented opportunity to perform genomics and bioinformatics analysis on this family of viruses. coronaviruses possess the largest genomes (26.4 to 31.7 kb) among all known rna viruses, with g + c contents varying from 32% to 43%. variable numbers of small orfs are present between the various conserved genes (orf1ab, spike, envelope, membrane and nucleocapsid) and downstrea ...201021994708
application of high-resolution melt curve analysis for classification of infectious bronchitis viruses in field specimens.a real-time polymerase chain reaction (pcr)/high-resolution melt (hrm) curve analysis protocol was developed in our laboratory to differentiate infectious bronchitis (ib) virus reference strains. in the current study, this method was used to detect and classify ib viruses in field submissions.201020854299
development of a porcine epidemic diarrhea virus m protein-based elisa for virus detection.a membrane (m), protein-based elisa was developed to detect porcine epidemic diarrhea virus (pedv). the m gene of pedv was expressed in escherichia coli. the purified recombinant m protein was used to immunize rabbits to generate a polyclonal antibody. immunofluorescence analysis indicated that the anti-pedv-m antibody reacted with pedv-infected cells. the antibody was utilized to develop an indirect elisa to detect pedv. other viruses, porcine transmissible gastroenteritis coronavirus, avian in ...201020882317
anti-infectious bronchitis virus (ibv) activity of 1,8-cineole: effect on nucleocapsid (n) protein.in the present study, anti-ibv (infectious bronchitis virus) activity of 1,8-cineole was studied by mtt assay, as well as docking and molecular dynamic (md) simulations. the cc50 of 1,8-cineole was above 10 mm. and the maximum noncytotoxic concentration (td0) of 1,8-cineole was determined to be 3.90 ± 0.22 mm, which was much higher than that of ribavirin (0.78 ± 0.15 mm). 1,8-cineole could inhibit ibv with an ic(50) of 0.61 mm. mtt assay showed that the inhibition of ibv by 1, 8-cineole appears ...201020919748
detection of avian nephritis virus in australian chicken flocks.avian nephritis virus (anv) is thought to infect poultry flocks worldwide, but no confirmed case has been reported in australia. the first such case is described in this study. cases of young chickens with clinical signs of dehydration and diarrhea were submitted to our laboratory and histopathology detected interstitial nephritis. vaccine strains of infectious bronchitis virus were detected in some of these cases but were not considered to be the causative agent. a total of seven fresh submissi ...201020945778
construction and immunogenicity of a recombinant fowlpox vaccine coexpressing s1 glycoprotein of infectious bronchitis virus and chicken il-18.infectious bronchitis virus (ibv) poses a major threat to the chicken industry worldwide. in this study, we developed a recombinant fowlpox virus (rfpv) vaccine expressing the ibv s1 gene and chicken interleukin-18 gene (il-18), rfpv-s1/il18. recombinant plasmid psy-s1/il18 was constructed by cloning chicken il-18 into fowlpox virus transfer plasmid containing s1 gene and transfected into the chicken embryo fibroblasts cell pre-infected with s-fpv-017 to generate rfpv-s1/il18. expression of the ...201020951182
the hydrophobic domain of infectious bronchitis virus e protein alters the host secretory pathway and is important for release of infectious virus.the coronavirus (cov) e protein plays an important role in virus assembly. the e protein is made in excess during infection and has been shown to have ion channel activity in planar lipid bilayers. however, a role in infection for the unincorporated e or its ion channel activity has not been described. to further investigate the function of the infectious bronchitis virus (ibv) e protein, we developed a recombinant version of ibv in which the e protein was replaced by a mutant containing a heter ...201021047962
infectious bronchitis viruses with naturally occurring genomic rearrangement and gene deletion.infectious bronchitis viruses (ibvs) are group iii coronaviruses that infect poultry worldwide. genetic variations, including whole-gene deletions, are key to ibv evolution. australian subgroup 2 ibvs contain sequence insertions and multiple gene deletions that have resulted in a substantial genomic divergence from international ibvs. the genomic variations present in australian ibvs were investigated and compared to those of another group iii coronavirus, turkey coronavirus (tcov). open reading ...201021049275
prevalence and phylogeny of coronaviruses in wild birds from the bering strait area (beringia).coronaviruses (covs) can cause mild to severe disease in humans and animals, their host range and environmental spread seem to have been largely underestimated, and they are currently being investigated for their potential medical relevance. infectious bronchitis virus (ibv) belongs to gamma-coronaviruses and causes a costly respiratory viral disease in chickens. the role of wild birds in the epidemiology of ibv is poorly understood. in the present study, we examined 1,002 cloacal and faecal sam ...201021060827
preparation and characterization of polyclonal antibody against severe acute respiratory syndrome-associated coronavirus spike protein.a truncated gene (designated s1) encoding the receptor-binding domain (rbd) in the spike (s) protein of severe acute respiratory syndrome-associated coronavirus (sars-cov) was amplified by pcr. the gene was cloned into prokaryotic expression vector pgex-6p-1, resulting in a recombinant plasmid pgex-sars-s1. subsequently, pgex-sars-s1 was transformed into host cells bl21(de3)plyss, and the expression of the s1 protein was induced by isopropyl β-d-thiogalactoside (iptg). polyclonal antibody agains ...201021087096
reverse transcription loop-mediated isothermal amplification for rapid detection of transmissible gastroenteritis virus.transmissible gastroenteritis virus (tgev) is the causative agent of porcine transmissible gastroenteritis, and sensitive detection methods are required for preventing the disease. in this article, reverse transcription-loop-mediated isothermal amplification (rt-lamp) was developed to detect tgev. three pairs of primers targeting the nucleocapsid (n) gene of tgev were synthesized and used in the rt-lamp. the optimization, sensitivity, and specificity of the rt-lamp were evaluated. our results sh ...201021127872
a type-specific blocking elisa for the detection of infectious bronchitis virus antibody.infectious bronchitis virus (ibv) infection has been a major threat to the poultry industry worldwide. current commercially available elisa kits detect group-specific antibodies; however, to understand the status of field infection, a monoclonal antibody (mab) blocking elisa (b-elisa) against local ibvs was developed. the selected mab showed specificity to taiwan ibv strains but had no cross-reactivity with the vaccine strain h120. using the hemagglutination inhibition (hi) test as a standard, t ...201021192982
structures of the n- and c-terminal domains of mhv-a59 nucleocapsid protein corroborate a conserved rna-protein binding mechanism in coronavirus.coronaviruses are the causative agent of respiratory and enteric diseases in animals and humans. one example is sars, which caused a worldwide health threat in 2003. in coronaviruses, the structural protein n (nucleocapsid protein) associates with the viral rna to form the filamentous nucleocapsid and plays a crucial role in genome replication and transcription. the structure of n-terminal domain of mhv n protein also implicated its specific affinity with transcriptional regulatory sequence (trs ...201021203940
isolation and molecular characterization of sul/01/09 avian infectious bronchitis virus, indicates the emergence of a new genotype in the middle east.infectious bronchitis virus (ibv) was isolated from trachea and kidney tissues of eight broiler farms in kurdistan region of north iraq from 2008 to 2010. the birds were suffering from respiratory and nephropathological symptoms and lesions. a 1116 bp hyper mutable spike glycoprotein (s1) gene was amplified and sequenced using conventional rt-pcr. sequence analysis and blast homology search in genbank data base indicate that two of the farms were infected with the 4/91 strain, one with an uniden ...201021216111
development of a real-time taqman rt-pcr assay for the detection of infectious bronchitis virus in chickens, and comparison of rt-pcr and virus isolation.a sensitive and specific method for the diagnosis of infectious bronchitis virus (ibv) is of great importance. in this study the development of a real-time taqman rt-pcr targeting the highly conserved nucleocapsid (n) gene of ibv and including an internal pcr control is described. the assay was specific for ibv and did not detect other avian pathogens, including turkey coronaviruses. a comparative limit of detection was determined for m41, an embryo-adapted strain, and is/885/00, a poorly embryo ...201019781572
the infection of primary avian tracheal epithelial cells with infectious bronchitis virus.here we introduce a culture system for the isolation, passaging and amplification of avian tracheal epithelial (ate) cells. the ate medium, which contains chicken embryo extract and fetal bovine serum, supports the growth of ciliated cells, goblet cells and basal cells from chicken tracheas on fibronectin- or matrigel-coated dishes. non-epithelial cells make up less than 10% of the total population. we further show that ate cells support the replication and spread of infectious bronchitis virus ...201019793537
emergence of a group 3 coronavirus through recombination.analyses of turkey coronavirus (tcov), an enteric disease virus that is highly similar to infectious bronchitis virus (ibv) an upper-respiratory tract disease virus in chickens, were conducted to determine the adaptive potential, and genetic changes associated with emergence of this group 3 coronavirus. strains of tcov that were pathogenic in poults and nonpathogenic in chickens did not adapt to cause disease in chickens. comparative genomics revealed two recombination sites that replaced the sp ...201020022075
isolation and genetic analysis revealed no predominant new strains of avian infectious bronchitis virus circulating in south china during 2004-2008.twenty-seven strains of avian infectious bronchitis virus (ibv) were isolated from dead or diseased chickens at different chicken farms in south china during 2004-2008, of which the s1 gene was sequenced. phylogenetic analysis of the s1 gene sequences of the isolated 27 strains together with 29 strains published in genbank revealed that all ibv strains except for one isolated and one published were clustered into six distinct genotypes i-vi. 26 isolated strains belong to genotypes i, ii, and iii ...201020022714
classification of ibv s1 genotypes by direct reverse transcriptase-polymerase chain reaction (rt-pcr) and relationship between serotypes and genotypes of strains isolated between 1998 and 2008 in japan.in this study, we attempted to establish a simple detection method for classification of ibv s1 genotypes by direct reverse transcriptase-polymerase chain reaction (rt-pcr). then, to evaluate the usefulness of the s1 genotype-specific rt-pcr, we examined the relationship between s1 genotypes and serotypes of ibv in japan. sequencing of the s1 genes of ibv and phylogenetic tree analysis were conducted. on the basis of the sequencing data of the s1 genotype samples, we determined primer sets speci ...201020093802
qx-type infectious bronchitis virus in commercial flocks in the uk. 201021262653
detection of ibv qx in commercial broiler flocks in the uk. 201021262658
elucidation of the avian nucleolar proteome by quantitative proteomics using silac and changes in cells infected with the coronavirus infectious bronchitis virus.the nucleolus is a dynamic subnuclear compartment involved in ribosome subunit biogenesis, regulation of cell stress and modulation of cellular growth and the cell cycle, among other functions. the nucleolus is composed of complex protein/protein and protein/rna interactions. it is a target of virus infection with many viral proteins being shown to localize to the nucleolus during infection. perturbations to the structure of the nucleolus and its proteome have been predicted to play a role in bo ...201020827733
genotyping of newly isolated infectious bronchitis virus isolates from northeastern georgia.sixteen infectious bronchitis virus (ibv) field isolates obtained from vaccinated commercial broiler chickens showing clinical respiratory disease were characterized by reverse transcriptase-polymerase chain reaction and sequence analysis of the hypervariable region of the s1 spike glycoprotein gene. the genetic relationship among these variants and reference strains was determined by phylogenetic analysis and use of the basic local alignment search tool. all the isolates formed a distinct phylo ...201021313832
genetic diversity of avian infectious bronchitis virus isolated from domestic chicken flocks and coronaviruses from feral pigeons in brazil between 2003 and 2009.to detect the presence of infectious bronchitis virus or avian coronavirus, a nested reverse transcriptase pcr (rt-pcr) method was developed with the aim of amplifying a fragment of 530 bases, comprising the gene coding s1 protein. in the first step, all samples were submitted to rna extraction, rt-pcr, and nested pcr. next, only the positive nested-pcr samples were propagated in specific-pathogen-free (spf) embryonated chicken eggs for virus isolation. positive samples were then sequenced and a ...201021313839
protection induced by infectious laryngotracheitis virus vaccines alone and combined with newcastle disease virus and/or infectious bronchitis virus vaccines.two types of live attenuated vaccines have been used worldwide for the control of infectious laryngotracheitis virus (iltv): 1) chicken embryo origin (ceo) vaccines; and 2) tissue culture origin vaccines (tco). however, the disease persists in spite of extensive use of vaccination, particularly in areas of intense broiler production. among the factors that may influence the efficiency of iltv live attenuated vaccines is a possible interference of newcastle disease virus (ndv) and infectious bron ...201021313841
molecular analysis of infectious bronchitis viruses isolated in slovenia between 1990 and 2005: a retrospective study.fifteen infectious bronchitis viruses (ibv) isolated from broiler and broiler breeder flocks in slovenia between 1990 and 2005 were molecularly characterised. ibv strains were divided into four genotypes by the analysis of the s1 gene region. four strains belonged to the massachusetts genotype, one strain was placed into the qx genotype, one strain formed a cluster together with the b1648 strain and nine strains were classified into the 624/i genotype. nine slovenian strains of the 624/i genotyp ...201020844944
reverse transcription loop-mediated isothermal amplification for the rapid detection of infectious bronchitis virus in infected chicken tissues.a reverse transcription loop-mediated isothermal amplification (rt-lamp) assay targeting the nucleocapsid phosphoprotein gene of infectious bronchitis virus (ibv) was developed. the detection limits for the ibv rt-lamp assay were 10(1) 50% egg infection dose (eid(50)) per 50 microl of titrated viruses and no cross-reaction of ibv rt-lamp was found when tested with other viruses including newcastle disease virus (ndv), avian reovirus (arv), and infectious laryngotrachietis virus (iltv) due to the ...201019835950
detection and molecular characterization of gene 3 and 5 of turkey coronavirus from turkeys with severe enteritis in brazil.turkey coronavirus (tcov) is a causative agent associated with poult enteritis and mortality syndrome (pems) in turkeys worldwide. the disease is an acute, highly contagious enteric disease that is characterized by depression, anorexia, diarrhea, and high mortality in commercial turkey flocks. the presence of tcov in 12 intestinal-content samples, from turkey flocks aged between 10 and 104 days and exhibiting severe enteritis, was monitored during the period of 2004 to 2006. tcov detection was a ...200919848072
characterization of new variants of avian infectious bronchitis virus in tunisia.three infectious bronchitis virus (ibv) strains, isolated from suspected tunisian broiler flocks, were characterized as variant viruses using genotyping and serotyping techniques. they were compared with commonly used vaccine strains, including 793/b, d274, and massachusetts types. reverse transcription-pcr-restriction fragment length polymorphism, nucleotide sequencing, and genbank blast database analyses of the hypervariable region of the s1 subunit of the virus spike gene showed that the thre ...200919848084
identification of a novel linear b-cell epitope in the m protein of avian infectious bronchitis coronaviruses.this report describes the identification of a novel linear b-cell epitope at the c-terminus of the membrane (m) protein of avian infectious bronchitis virus (ibv). a monoclonal antibody (mab) (designated as 15e2) against the ibv m protein was prepared and a series of 14 partially-overlapping fragments of the ibv m gene were expressed with a gst tag. these peptides were subjected to enzyme-linked immunosorbent assay (elisa) and western blotting analysis using mab 15e2 to identify the epitope. a l ...200919851732
rapid detection of infectious bursal disease virus by reverse transcription loop-mediated isothermal amplification assay.a reverse transcription loop-mediated isothermal amplification (rt-lamp) assay was developed for the rapid identification of infectious bursal disease virus (ibdv). the rt-lamp assay used a set of 4 primers to amplify the viral protein 2 gene of ibdv for the detection of ibdv, showing not only high efficiency but also analytic specificity. the data demonstrated that the rt-lamp assay detected 30 different ibdv isolates, had no cross-reaction with 3 other avian viruses (infectious bronchitis viru ...200919901286
multiplex polymerase chain reaction for the detection and differentiation of avian influenza viruses and other poultry respiratory pathogens.a multiplex reverse transcription-pcr (mrt-pcr) was developed and standardized for the detection of type a influenza viruses, avian influenza virus (aiv) subtype h7, h9, and h5 hemagglutinin gene with simultaneous detection of 3 other poultry respiratory pathogens, newcastle disease virus (ndv), infectious bronchitis virus (ibv), and infectious laryngotracheitis virus (iltv). seven sets of specific oligonucleotide primers were used in this study for the m gene of aiv and hemagglutinin gene of su ...200919903950
pathogenicity and antigenicity of a new variant of korean nephropathogenic infectious bronchitis virus.despite the existence of an active vaccination program, recently emerged strains of nephropathogenic infectious bronchitis virus (ibv) in korea have caused significant economic losses in the poultry industry. in this study, we assessed the pathogenic and antigenic characteristics of a k-iib type field strain of ibv that emerged in korea since 2003, such as kr/q43/06. specific pathogen free 1-week-old chickens exhibited severe respiratory symptoms (dyspnea) and nephropathogenic lesions (swollen k ...200919934604
effect of a live mycoplasma synoviae vaccine on the production of eggshell apex abnormalities induced by a m. synoviae infection preceded by an infection with infectious bronchitis virus d1466.an experimental study was conducted to assess the effect of a live mycoplasma synoviae vaccine (vaxsafe ms; bioproperties pty ltd, ringwood, victoria, australia) on m. synoviae-induced eggshell apex abnormalities (eaa). four experimental groups of specified-pathogen-free white laying hens were made. all groups were inoculated with infectious bronchitis virus d1466 at 18 weeks of age. one group did not receive further treatment (non-vaccinated non-challenged (nvnc)). two groups were vaccinated at ...200919937520
comparison of the pathogenicity of qx-like, m41 and 793/b infectious bronchitis strains from different pathological conditions.five qx-like infectious bronchitis virus (ibv) strains, isolated from different field outbreaks and two reference ibv strains of known serotypes (m41 and 793/b), were used in the present study to investigate and compare their pathogenicity for 1-day-old specific pathogen free chickens. the ability of the strains to inhibit trachea epithelium ciliary activity, to induce immune response, to replicate and to cause histopathological lesions in designated organs was followed by repeated samplings dur ...200919937534
immunohistochemistry for detection of avian infectious bronchitis virus strain m41 in the proventriculus and nervous system of experimentally infected chicken embryos.infectious bronchitis virus primarily induces a disease of the respiratory system, different ibv strains may show variable tissue tropisms and also affect the oviduct and the kidneys. proventriculitis was also associated with some new ibv strains. aim of this study was to investigate by immunohistochemistry (ihc) the tissue tropism of avian infectious bronchitis virus (ibv) strain m41 in experimentally infected chicken embryos.200919196466
identification of sequence changes responsible for the attenuation of avian infectious bronchitis virus strain arkansas dpi.infectious bronchitis virus (ibv) is the causal agent of infectious bronchitis, which still remains one of the most important poultry diseases worldwide because of numerous serotypes and variants. a virulent strain of ibv, isolated from arkansas (ark), was propagated in embryonated eggs (ark dpi 11). following 101 serial passages in embryonated eggs, an attenuated strain of ibv was established (ark dpi 101) that does not induce histopathological lesions in the tracheae of infected chicks. to ide ...200919219402
sequence and phylogenetic analysis of s1, s2, m, and n genes of infectious bronchitis virus isolates from malaysia.two malaysian infectious bronchitis virus isolates, mh5365/95 and v9/04 were characterized based on sequence and phylogenetic analyses of s1, s2, m, and n genes. nucleotide sequence alignments revealed many point mutations, short deletions, and insertions in s1 region of both ibv isolates. phylogenetic analysis of s1 gene and sequences analysis of m gene indicated that mh5365/95 and v9/04 belong to non-massachusetts strain. however, both isolates share only 77% identity. analysis based on s1 gen ...200919242786
interaction of the coronavirus infectious bronchitis virus membrane protein with beta-actin and its implication in virion assembly and budding.coronavirus m protein is an essential component of virion and plays pivotal roles in virion assembly, budding and maturation. the m protein is integrated into the viral envelope with three transmembrane domains flanked by a short amino-terminal ectodomain and a large carboxy-terminal endodomain. in this study, we showed co-purification of the m protein from coronavirus infectious bronchitis virus (ibv) with actin. to understand the cellular factors that may be involved in virion assembly, buddin ...200919287488
rapid detection and non-subjective characterisation of infectious bronchitis virus isolates using high-resolution melt curve analysis and a mathematical model.infectious bronchitis virus (ibv) is a coronavirus that causes upper respiratory, renal and/or reproductive diseases with high morbidity in poultry. classification of ibv is important for implementation of vaccination strategies to control the disease in commercial poultry. currently, the lengthy process of sequence analysis of the ibv s1 gene is considered the gold standard for ibv strain identification, with a high nucleotide identity (e.g. > or =95%) indicating related strains. however, this ...200919301093
molecular characterization of avian infectious bronchitis virus strains from outbreaks in argentina (2001-2008).twenty infectious bronchitis virus isolates were recovered from broilers and layers in different outbreaks amongst commercial poultry flocks in different geographic regions of argentina from 2001 to 2008. the viruses were isolated from the tracheas, lungs, and caecal tonsils of birds that were showing respiratory signs. further analysis based on their nucleotide and amino acid sequences in hypervariable region (hvr) 1 and the intervening sequence including hvrs 1 and 2 (hvr1/2) of the s1 gene wa ...200919322714
infectious bronchitis virus in jordanian chickens: seroprevalence and detection.infectious bronchitis (ib) is one of the most important viral diseases of poultry; it causes major economic losses to the poultry industry. this study was conducted to investigate the prevalence of infectious bronchitis virus (ibv) in commercial chicken flocks in jordan. serum samples from 70 commercial chicken flocks (40 broilers, 18 layers, and 12 broiler breeders) free from respiratory disease were collected and screened for the presence of massachusetts-41 (m-41), d274, and 4/91 strain antig ...200919337618
[use of multiplex pcr method with real-time detection for differential diagnosis of respiratory viral infections].multiplex real-time polymerase chain reaction test-system with fluorescent detection (rt-pcr) for simultaneous identification of main agents of acute respiratory viral infections: influenza a (iav) and b viruses (ibv), parainfluenza viruses types 1, 2, 3, 4 (piv 1 - 4), adenoviruses (adv), respiratory syncitial virus (rsv), rhinoviruses (rv) and enteroviruses (ev), in presence internal positive control (ipc) represented by vaccine strain of rubella virus ra 27/3. using multiplex rt-pcr method, r ...200919338239
genetic diversity of avian infectious bronchitis viruses in japan based on analysis of s2 glycoprotein gene.to understand the genetic diversity of the s2 gene of infectious bronchitis viruses (ibv) isolated in japan, we determined the nucleotide sequences of these ibvs using the reverse transcriptase polymerase chain reaction method coupled with direct sequencing. ibv isolated in japan were classified into six different groups by phylogenetic analysis based on the s2 gene. however, the classification based on the s2 gene of ibv isolated in japan was different for some of the strains from those obtaine ...200919346695
broadly targeted multiprobe qpcr for detection of coronaviruses: coronavirus is common among mallard ducks (anas platyrhynchos).coronaviruses (covs) can cause trivial or fatal disease in humans and in animals. detection methods for a wide range of covs are needed, to understand viral evolution, host range, transmission and maintenance in reservoirs. a new concept, "multiprobe qpcr", which uses a balanced mixture of competing discrete non- or moderately degenerated nuclease degradable (taqman) probes was employed. it provides a broadly targeted and rational single tube real-time reverse transcription pcr ("nqpcr") for the ...200919406168
towards construction of viral vectors based on avian coronavirus infectious bronchitis virus for gene delivery and vaccine development.manipulation of the coronavirus genome to accommodate and express foreign genes is an attractive approach for gene delivery and vaccine development. by using an infectious cloning system developed recently for the avian coronavirus infectious bronchitis virus (ibv), the enhanced green fluorescent protein (egfp) gene, the firefly luciferase gene and several host and viral genes (eif3f, sars orf6, dengue virus 1 core protein gene) were inserted into various positions of the ibv genome, and the eff ...200919409420
identification of in vivo-interacting domains of the murine coronavirus nucleocapsid protein.the coronavirus nucleocapsid protein (n), together with the large, positive-strand rna viral genome, forms a helically symmetric nucleocapsid. this ribonucleoprotein structure becomes packaged into virions through association with the carboxy-terminal endodomain of the membrane protein (m), which is the principal constituent of the virion envelope. previous work with the prototype coronavirus mouse hepatitis virus (mhv) has shown that a major determinant of the n-m interaction maps to the carbox ...200919420077
rapid subtyping of h9n2 influenza virus by a triple reverse transcription polymerase chain reaction.the aim of this study was to develop a rapid, cost-saving triple reverse transcription polymerase chain reaction (triple rt-pcr) for subtyping h9n2 avian influenza viruses (aivs). the three primer pairs for amplification of target sequences of nucleoprotein (np), hemagglutinin (ha) and neuraminidase (na) genes, respectively, were designed for subtyping the viruses in the triple rt-pcr. the sensitivity of triple rt-pcr was found to be 10(2) copies per reaction for each of np, h9 and n2 gene. the ...200919428570
massachusetts live vaccination protects against a novel infectious bronchitis virus s1 genotype dmv/5642/06.four infectious bronchitis virus (ibv) isolates were recovered from commercial broiler chicken flocks located on the delmarva peninsula (east coast of the united states) in the spring of 2006. sequence analysis of the s1 subunit of the spike glycoprotein gene showed the four isolates were highly related to each other (> or = 99.6% nucleotide identity; > or = 98.9% amino acid identity). basic local alignment search tool analysis indicated the highest s1 amino acid identity of isolate dmv/5642/06, ...200919432014
comparative analysis of the effect of glycyrrhizin diammonium and lithium chloride on infectious bronchitis virus infection in vitro.the effects of glycyrrhizin diammonium (gd) and lithium chloride (licl) on cell infection by avian infectious bronchitis virus (ibv) were investigated using cytopathic effect observation, plaque-reduction assay and reverse transcriptase-polymerase chain reaction. the anti-viral effect of gd and licl on virus, on virus-infected cells or on cells pre-treated by both drugs was analysed, respectively. our results showed that gd had a direct antiviral activity, leading to complete inhibition of cell ...200919468938
genetic analysis of the s1 gene of 4/91 type infectious bronchitis virus isolated in japan.s1 gene sequences for infectious bronchitis virus (ibv) strains of the 4/91 genotype (commonly called 793b) isolated from field outbreaks in japan were analyzed to ascertain the relationship to 4/91 vaccine strain. three field isolates (jp/wakayama/2003, jp/iwate/2005 and jp/saitama/2006) from flocks not immunized with a 4/91 type live ibv vaccine and one isolate (jp/wakayama-2/2004) from a flock immunized with a 4/91 type live vaccine were examined. the amino acid identities among jp/wakayama/2 ...200919498283
altered pathogenicity, immunogenicity, tissue tropism and 3'-7kb region sequence of an avian infectious bronchitis coronavirus strain after serial passage in embryos.in this study, we attenuated a chinese lx4-type nephropathogenic infectious bronchitis virus (ibv) strain, ck/ch/lhlj/04v, by serial passage in embryonated chicken eggs. based on sequence analysis of the 3'-7kb region, the ck/ch/lhlj/04v virus population contained subpopulations with a mixture of genetic mutants. the titers of the virus increased gradually during serial passage, but the replication capacity decreased in chickens. the virus was partially attenuated at passage 40 (p40) and p70, an ...200919523910
coadministration of chicken gm-csf with a dna vaccine expressing infectious bronchitis virus (ibv) s1 glycoprotein enhances the specific immune response and protects against ibv infection.various approaches have been developed to improve the efficacy of dna vaccination, such as the use of plasmids expressing cytokines as molecular adjuvants. the purpose of the present study was to determine whether co-administration of a plasmid containing a chicken granulocyte-macrophage colony-stimulating factor (gm-csf) gene and a plasmid containing the s1 gene of infectious bronchitis virus (ibv) could enhance the immune response and protection efficacy in chickens against challenge by virule ...200919543689
proteolytic activation of the spike protein at a novel rrrr/s motif is implicated in furin-dependent entry, syncytium formation, and infectivity of coronavirus infectious bronchitis virus in cultured cells.the spike (s) protein of the coronavirus (cov) infectious bronchitis virus (ibv) is cleaved into s1 and s2 subunits at the furin consensus motif rrfrr(537)/s in virus-infected cells. in this study, we observe that the s2 subunit of the ibv beaudette strain is additionally cleaved at the second furin site (rrrr(690)/s) in cells expressing s constructs and in virus-infected cells. detailed time course experiments showed that a peptide furin inhibitor, decanoyl-arg-val-lys-arg-chloromethylketone, b ...200919553314
the protective immune response against infectious bronchitis virus induced by multi-epitope based peptide vaccines.peptide vaccine was found to be an effective and powerful approach to a variety of pathogens. to explore multi-epitope based peptide vaccines against infectious bronchitis virus (ibv), the immunogenic peptides were fused to the 3' terminal of glutathione s transferase gene (gst) and expressed in escherichia coli. elisa and western blot analysis showed that the purified fusion proteins had excellent immune activity with chicken anti-ibv serum. during the vaccination course, the candidate peptide ...200919584555
molecular characterization and pathogenicity of infectious bronchitis coronaviruses: complicated evolution and epidemiology in china caused by cocirculation of multiple types of infectious bronchitis coronaviruses.to monitor and study the molecular epidemiology, evolution and pathogenicity of infectious bronchitis viruses (ibvs) in china in recent years and further our knowledge of the evolution of ibvs.200919590226
genetically diverse coronaviruses in wild bird populations of northern england.infectious bronchitis virus (ibv) causes a costly respiratory viral disease of chickens. the role of wild birds in the epidemiology of ibv is poorly understood. we detected diverse coronaviruses by pcr in wildfowl and wading birds in england. sequence analysis showed some viruses to be related to ibv.200919624927
characterization of a new genotype and serotype of infectious bronchitis virus in western africa.between 2002 and 2007, more than 1000 chickens from commercial farms, live bird markets and backyard farms in nigeria and niger were tested for the presence of the infectious bronchitis virus (ibv) genome. phylogenetic analysis of full-length sequences of the spike 1 (s1) gene revealed a new genotype of ibv that we refer to as 'ibadan'. the minimum genetic distance to the closest 'non-ibadan' strains (uk/7/93 at the nucleotide level; h120 and m41 at the amino acid level) reached 24 and 32 % at t ...200919625463
infectious bronchitis virus field vaccination coverage and persistence of arkansas-type viruses in commercial broilers.to determine the coverage of infectious bronchitis virus (ibv) vaccine field boost in commercial broilers, estimate the relative amount of vaccine virus in the trachea, and follow the clearance of the vaccine, we collected approximately 100 tracheal swabs at various times postvaccination from 10 different flocks and used real-time reverse transcriptase-pcr (rt-pcr) to detect the virus. this allowed us to detect vaccine virus in as few as 3% of the birds in a flock of 20,000 birds with a 95% conf ...200919630221
cpg oligodeoxynucleotides activate innate immune response that suppresses infectious bronchitis virus replication in chicken embryos.the understanding of innate immune modulation by pathogens and immune-modulating agents, including synthetic oligodeoxynucleotides (cpg odns), has offered several new approaches to improve prophylactic and therapeutic strategies against infectious diseases in humans and animals. however, in this regard not much work has been done in avian medicine. in the present study, we analyzed the kinetics of interferon (ifn), cytokine, and chemokine mrna expression in chicken embryonic spleen at 6 hr, 24 h ...200919630234
expression, crystallization and preliminary x-ray diffraction analysis of the n-terminal domain of nsp2 from avian infectious bronchitis virus.avian infectious bronchitis virus (ibv) is a prototype of the group iii coronaviruses and encodes 15 nonstructural proteins which make up the transcription/replication machinery. the nsp2 protein from ibv has a unique and novel sequence and has no experimentally confirmed function in replication, whereas it has been proposed to be crucial for early viral infection and may inhibit the early host immune response. the gene that encodes a double-mutant ibv nsp2 n-terminal domain (residues 9-393 of t ...200919652340
serological studies of infectious bronchitis vaccines against japanese field isolates of homologous and heterologous genotypes.the genetic diversity of the partial s1 gene involving the hyper variable region for infectious bronchitis (ib) vaccine strains in japan were compared with those of ib virus isolated from the field in japan. field isolates have mainly been classified into three major genotypes, jp-i, jp-ii and jp-iii, since 2003; however, the 4/91 genotype was detected from recent field isolates in japan. the virus neutralization (vn) activity with vaccine immunized serum was investigated to evaluate the protect ...200919652475
detection and molecular characterization of infectious bronchitis virus isolated from recent outbreaks in broiler flocks in thailand.thirteen field isolates of infectious bronchitis virus (ibv) were isolated from broiler flocks in thailand between january and june 2008. the 878-bp of the s1 gene covering a hypervariable region was amplified and sequenced. phylogenetic analysis based on that region revealed that these viruses were separated into two groups (i and ii). ibv isolates in group i were not related to other ibv strains published in the genbank database. group 1 nucleotide sequence identities were less than 85% and am ...200919687622
comparative evaluation of real-time pcr and conventional rt-pcr during a 2 year surveillance for influenza and respiratory syncytial virus among children with acute respiratory infections in kolkata, india, reveals a distinct seasonality of infection.acute respiratory tract infections (artis) are one of the most common causes of morbidity and mortality in young children worldwide. influenza virus and respiratory syncytial virus (rsv) are the predominant aetiological agents during seasonal epidemics, and thus rapid and sensitive molecular tests for screening for such agents and timely identification of epidemics are required. this study compared real-time quantitative pcr (qpcr) with conventional rt-pcr for parallel identification of influenz ...200919713363
detection and differentiation of four poultry diseases using asymmetric reverse transcription polymerase chain reaction in combination with oligonucleotide microarrays.asymmetric reverse transcription polymerase chain reaction (rt-pcr) and microarrays were combined to distinguish 4 viruses, including avian influenza virus (aiv), newcastle disease virus (ndv), infectious bronchitis virus (ibv), and infectious bursal disease virus (ibdv), and hemagglutinin (ha) subtypes h5, h7, and h9, and neuraminidase (na) subtypes n1 and n2 of aiv. the aiv matrix protein (m), and ha and na genes, ibv nucleoprotein (np) gene, ndv np gene, and ibdv a fragment gene were cloned i ...200919737757
inhibition of protein kinase r activation and upregulation of gadd34 expression play a synergistic role in facilitating coronavirus replication by maintaining de novo protein synthesis in virus-infected cells.a diversity of strategies is evolved by rna viruses to manipulate the host translation machinery in order to create an optimal environment for viral replication and progeny production. one of the common viral targets is the alpha subunit of eukaryotic initiation factor 2 (eif-2alpha). in this report, we show that phosphorylation of eif-2alpha was severely suppressed in human and animal cells infected with the coronavirus infectious bronchitis virus (ibv). to understand whether this suppression i ...200919776135
characterization and membrane gene-based phylogenetic analysis of avian infectious bronchitis virus chinese strain hh06.a chinese isolate of avian infectious bronchitis virus (ibv) designated hh06 was isolated from the kidney tissues of a chicken flock experiencing an outbreak of nephritis. in vivo pathogenicity of the ibv isolate hh06 was determined by inoculating specific pathogen-free (spf) chickens. the clinical signs and related gross lesions of hh06 infected chickens were similar with those of the field-infected chickens. spf embryonated eggs were inoculated with virus suspension for serial passage and thei ...200918792774
lna probe-based real-time rt-pcr for the detection of infectious bronchitis virus from the oviduct of unvaccinated and vaccinated laying hens.in the present study, lna-probe based real-time pcr was designed for the detection and absolute quantification of infectious bronchitis virus (ibv) from the oviduct of unvaccinated and vaccinated hens after ibv challenge. using a recombinant plasmid standard, the detection limit of the reaction was found to be 10 copies and independent assay runs showed reproducible ct values. amongst the unvaccinated hens, the virus could be detected between 6 and 20 days post-infection (p.i.), with a peak of v ...200918955085
comparative analysis of complete genome sequences of three avian coronaviruses reveals a novel group 3c coronavirus.in this territory-wide molecular epidemiology study of coronaviruses (covs) in hong kong involving 1,541 dead wild birds, three novel covs were identified in three different bird families (bulbul cov hku11 [bucov hku11], thrush cov hku12 [thcov hku12], and munia cov hku13 [mucov hku13]). four complete genomes of the three novel covs were sequenced. their genomes (26,396 to 26,552 bases) represent the smallest known cov genomes. in phylogenetic trees constructed using chymotrypsin-like protease ( ...200918971277
course of infection and immune responses in the respiratory tract of ibv infected broilers after superinfection with e. coli.colibacillosis results from infection with avian pathogenic escherichia coli bacteria. healthy broilers are resistant to inhaled e. coli, but previous infection with vaccine or virulent strains of infectious bronchitis virus (ibv) predisposes birds for severe colibacillosis. the aim of this study was to investigate how ibv affects the course of events upon infection with e. coli. broilers were inoculated with ibv h120 vaccine virus or virulent m41 and challenged 5 days later with e. coli 506. a ...200918976820
crystal structures of two coronavirus adp-ribose-1''-monophosphatases and their complexes with adp-ribose: a systematic structural analysis of the viral adrp domain.the coronaviruses are a large family of plus-strand rna viruses that cause a wide variety of diseases both in humans and in other organisms. the coronaviruses are composed of three main lineages and have a complex organization of nonstructural proteins (nsp's). in the coronavirus, nsp3 resides a domain with the macroh2a-like fold and adp-ribose-1"-monophosphatase (adrp) activity, which is proposed to play a regulatory role in the replication process. however, the significance of this domain for ...200918987156
progression of lesions in the respiratory tract of broilers after single infection with escherichia coli compared to superinfection with e. coli after infection with infectious bronchitis virus.the progression of escherichia coli lesions was studied in the respiratory tract of 4-week-old commercial broilers. lesions were induced after a single intratracheal e. coli infection, and after an infection with e. coli preceded 5 days earlier by an oculo-nasal and intratracheal infectious bronchitis virus (ibv) infection of either the virulent m41 strain or the h120 vaccine strain. trachea, lung and thoracic airsac lesions were examined macroscopically and microscopically. tissue samples were ...200919004507
formation of stable homodimer via the c-terminal alpha-helical domain of coronavirus nonstructural protein 9 is critical for its function in viral replication.coronaviruses devote more than three quarters of their coding capacity to encode two large polyproteins (1a and 1ab polyproteins), which are proteolytically processed into 15-16 mature, nonstructural replicase proteins (nsp1 to 16). these cleavage products are believed to play essential roles in replication of the giant rna genome of approximately 30 kb and transcription of a nested set of 5 to 9 subgenomic rna species by a unique discontinuous transcription mechanism. in this report, one of the ...200919022466
infectious bronchitis virus induces acute interferon-gamma production through polyclonal stimulation of chicken leukocytes.infectious bronchitis virus, a member of the coronaviridae, is a respiratory pathogen in poultry. we found that in vitro stimulation with ibv resulted in chifn-gamma production in splenocytes of both infected birds and uninfected birds. the non-specific stimulation did not occur when other avian viruses or other coronaviruses were used or when mammalian cells were stimulated with ibv. inactivation of ibv reduced chifn-gamma production, but chifn-gamma remained elevated compared to unstimulated c ...200919070879
identification of taiwan and china-like recombinant avian infectious bronchitis viruses in taiwan.infectious bronchitis virus (ibv) infections in poultry cause great economic losses to the poultry industry worldwide. the emergence of viral variants complicates disease control. the ibv strains in taiwan were clustered into two groups, taiwan group i and taiwan group ii, based on the s1 gene. a variant was previously identified and showed a distinct s1 gene homology with other local strains. this study investigated the 3' 7.3 kb genome of eight taiwan strains isolated from 1992 to 2007. the ge ...200919100792
comparative analysis of the sialic acid binding activity and the tropism for the respiratory epithelium of four different strains of avian infectious bronchitis virus.avian infectious bronchitis virus (ibv) is a major pathogen in commercial poultry flocks. we recently demonstrated that sialic acid serves as a receptor determinant for ibv on the tracheal epithelium. here we compared the ibv strains beaudette, 4/91, italy02, and qx for their sialic acid-binding properties. we demonstrate that sialic acid binding is important for the infection of primary chicken kidney cells and the tracheal epithelium by all four strains. there were only slight differences betw ...200919156578
induction of eggshell apex abnormalities by mycoplasma synoviae: field and experimental studies.a novel eggshell pathology, characterized by an altered shell surface, thinning, increased translucency, and cracks and breaks in the eggshell apex, has become increasingly common in layer flocks of various breeds in the netherlands. two field studies found an association between the eggshell apex abnormalities (eaa) and infection with mycoplasma synoviae. m. synoviae was isolated from the oviduct of birds that produced abnormal eggs, but not from birds in control flocks, although both affected ...200919156584
effects of infectious bronchitis virus vaccine on the oviduct of hens.in australia, currently, all pullets reared for egg production are vaccinated with live attenuated strains of infectious bronchitis virus. various vaccines and protocols to control this viral disease have been developed, although the severity of the disease varies from place to place and flock to flock. in the present trial, the effects of vaccine strains a3 and vic s on the oviduct of laying hens were assessed by histopathology, electron microscopy, serology and also by determining the presence ...200919174178
crystal structures of the x-domains of a group-1 and a group-3 coronavirus reveal that adp-ribose-binding may not be a conserved property.the polyproteins of coronaviruses are cleaved by viral proteases into at least 15 nonstructural proteins (nsps). consisting of five domains, nsp3 is the largest of these (180-210 kda). among these domains, the so-called x-domain is believed to act as adp-ribose-1''-phosphate phosphatase or to bind poly(adp-ribose). however, here we show that the x-domain of infectious bronchitis virus (strain beaudette), a group-3 coronavirus, fails to bind adp-ribose. this is explained on the basis of the cryst ...200919177346
serosurvey of five viruses in chickens on smallholdings in bangladesh.a serologic survey was undertaken in chickens in smallholdings in bangladesh for avian influenza a virus (aiv), egg drop syndrome '76 virus (eds'76v), infectious bronchitis virus (ibv), newcastle disease virus (ndv) and reovirus (rv) in three phases: january 2002-may 2003, september 2003-august 2004, and august 2005-march 2006. four hundred thirty-six sera collected in the 2nd phase, 295 in the first phase, 755 in the 1st plus 2nd phases and 295 in the 1st phase were investigated for aiv, eds'76 ...200918723236
complete genome sequence analysis of a predominant infectious bronchitis virus (ibv) strain in china.infectious bronchitis (ib) is one of the major diseases in poultry flocks all over the world caused by infectious bronchitis virus (ibv). in the study, the complete genome sequence of strain a2 was sequenced and analyzed, which was a predominant ibv strain in china. the results indicated that there were mutations, insertions, and deletions distributed in the whole genome. the a2 virus had the highest identity to s14 and bj in terms of full genome, whereas had a further distance to massachusetts ...200918770015
evaluation of the protection conferred by commercial vaccines and attenuated heterologous isolates in china against the ck/ch/ldl/97i strain of infectious bronchitis coronavirus.avian infectious bronchitis virus (ibv) causes tremendous economic losses to the poultry industry worldwide. different serotypes of this virus show little cross-protection. the present study investigated the genotypic relationship between ck/ch/ldl/97i-type strains and reference ibvs based on s1 gene comparisons and the protection provided by vaccination with commercial vaccines and attenuated homologous and heterologous strains. phylogenetic analysis and the comparison of s1 showed that ck/ch/l ...200917936045
[avian infectious bronchitis disease in tunisia: seroprevalence, pathogenicity and compatibility studies of vaccine-field isolates].a sero-epidemiological study was carried out on 5660 sera collected, between 2006 and 2008, from different flocks in different regions of the country. the elisa results showed low levels of antibodies indicating vaccination failures. 45 to 69% of the flocks showed positive levels of antibodies and only 5 to 15% of these were protected. the pathogenicity studies of the tunisian field isolates tn20/00 and tn335/01 demonstrated high clinical and lesion scores indicating the pathogenic effect of the ...200920707223
characteristics of a very virulent infectious bursal disease virus from california.an outbreak of infectious bursal disease (ibd) in two california layer flocks resulted in the isolation of two infectious bursal disease viruses designated ra and rb. increased mortality plus gross and histopathology in the layer flocks suggested ra and rb could be very virulent infectious bursal disease virus (vvibdv). preliminary studies indicated that high mortality resulted when bursa homogenates from the layer farms were used to inoculate specific-pathogen-free (spf) chicks. in addition, ra ...200920095162
multivalent dna vaccine enhanced protection efficacy against infectious bronchitis virus in chickens.for efficacious dna vaccine development against infectious bronchitis virus (ibv), the immunogenicity of a multivalent dna vaccine was evaluated. three expression plasmids each targeting spike protein (s1), nucleocapsid protein (n), and membrane protein (m) of ibv were prepared. chickens were immunized with either individual plasmids (monovalent) or with a combination of all plasmids (multivalent). immunization with the multivalent dna vaccine induced synergistic augmentation of humoral and cell ...200920046025
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