Publications
| Title | Abstract | Year Filter | PMID(sorted descending) Filter |
|---|
| completion of the porcine epidemic diarrhoea coronavirus (pedv) genome sequence. | the sequence of the replicase gene of porcine epidemic diarrhoea virus (pedv) has been determined. this completes the sequence of the entire genome of strain cv777, which was found to be 28,033 nucleotides (nt) in length (excluding the poly a-tail). a cloning strategy, which involves primers based on conserved regions in the predicted orf1 products from other coronaviruses whose genome sequence has been determined, was used to amplify the equivalent, but as yet unknown, sequence of pedv. primary ... | 2001 | 11724265 |
| ribosomal pausing at a frameshifter rna pseudoknot is sensitive to reading phase but shows little correlation with frameshift efficiency. | here we investigated ribosomal pausing at sites of programmed -1 ribosomal frameshifting, using translational elongation and ribosome heelprint assays. the site of pausing at the frameshift signal of infectious bronchitis virus (ibv) was determined and was consistent with an rna pseudoknot-induced pause that placed the ribosomal p- and a-sites over the slippery sequence. similarly, pausing at the simian retrovirus 1 gag/pol signal, which contains a different kind of frameshifter pseudoknot, also ... | 2001 | 11713298 |
| reverse genetics system for the avian coronavirus infectious bronchitis virus. | major advances in the study of the molecular biology of rna viruses have resulted from the ability to generate and manipulate full-length genomic cdnas of the viral genomes with the subsequent synthesis of infectious rna for the generation of recombinant viruses. coronaviruses have the largest rna virus genomes and, together with genetic instability of some cdna sequences in escherichia coli, this has hampered the generation of a reverse-genetics system for this group of viruses. in this report, ... | 2001 | 11711626 |
| further identification and characterization of novel intermediate and mature cleavage products released from the orf 1b region of the avian coronavirus infectious bronchitis virus 1a/1b polyprotein. | the coronavirus 3c-like proteinase is one of the viral proteinases responsible for processing of the 1a and 1a/1b polyproteins to multiple mature products. in cells infected with avian coronavirus infectious bronchitis virus (ibv), three proteins of 100, 39, and 35 kda, respectively, were previously identified as mature cleavage products released from the 1b region of the 1a/1b polyprotein by the 3c-like proteinase. in this report, we show the identification of two more cleavage products of 68 a ... | 2001 | 11601893 |
| origin and evolution of georgia 98 (ga98), a new serotype of avian infectious bronchitis virus. | we previously identified ga98, a new serotype of infectious bronchitis virus (ibv), which is closely related to the de072 serotype of ibv genetically, but not antigenically. herein, we analyzed the 421bp sequence of a hypervariable region (hvr) (position 114-534, counting from the atg start site) of the s1 subunit of ga98 ibvs to further examine the evolution of these viruses. these viruses were isolated between the years 1997 and 2000. phylogenetic analysis of the deduced amino acid sequence on ... | 2001 | 11597746 |
| cases of swollen head syndrome in broiler chickens in greece. | from 50 commercial broiler flocks included in a study concerning respiratory disease, signs of swollen head syndrome (shs) were shown in eight. postmortem examination was performed in eight birds showing signs of shs from each flock. the trachea and head from each bird were collected for laboratory investigation. an enzyme-linked immunosorbent assay (elisa) was used for the detection of viral and avian mycoplasma antigens in the trachea, and bacteriologic examinations were performed from the inf ... | 2001 | 11569754 |
| infectious bronchitis serology in broilers and broiler breeders: correlations between antibody titers and performance in vaccinated flocks. | in this study, a follow-up was made between 1993 and 1997 from broiler breeders at birth down to offspring broilers at processing, through vertically integrated registration of infectious bronchitis virus (ibv) antibody titers and performance data. all measurements were used two by two in a simple correlation study to calculate the degree to which they were linearly correlated. the antibody patterns in the broiler breeders indicated frequent field infections breaking through vaccinal immunity. s ... | 2001 | 11569734 |
| localization to the nucleolus is a common feature of coronavirus nucleoproteins, and the protein may disrupt host cell division. | the subcellular localization of transmissible gastroenteritis virus (tgev) and mouse hepatitis virus (mhv) (group i and group ii coronaviruses, respectively) nucleoproteins (n proteins) were examined by confocal microscopy. the proteins were shown to localize either to the cytoplasm alone or to the cytoplasm and a structure in the nucleus. this feature was confirmed to be the nucleolus by using specific antibodies to nucleolin, a major component of the nucleolus, and by confocal microscopy to im ... | 2001 | 11533198 |
| the autocatalytic release of a putative rna virus transcription factor from its polyprotein precursor involves two paralogous papain-like proteases that cleave the same peptide bond. | the largest replicative protein of coronaviruses is known as p195 in the avian infectious bronchitis virus (ibv) and p210 (p240) in the mouse hepatitis virus. it is autocatalytically released from the precursors pp1a and pp1ab by one zinc finger-containing papain-like protease (plpro) in ibv and by two paralogous plpros, pl1pro and pl2pro, in mouse hepatitis virus. the plpro-containing proteins have been recently implicated in the control of coronavirus subgenomic mrna synthesis (transcription). ... | 2001 | 11431476 |
| molecular characterization of infectious bronchitis virus isolates foreign to the united states and comparison with united states isolates. | eleven infectious bronchitis virus (ibv) isolates foreign to the united states were analyzed by using reverse transcriptase (rt)-polymerase chain reaction (pcr)/restriction fragment length polymorphism (rflp) and s1 glycoprotein gene sequencing. two of the isolates generated rflp patterns that resembled the mass 41 strain. seven novel rflp patterns were detected among the other nine foreign ibv isolates. five of the foreign isolates were further analyzed by s1 glycoprotein gene sequencing in our ... | 2001 | 11417834 |
| characterization of three infectious bronchitis virus isolates from china associated with proventriculus in vaccinated chickens. | outbreaks of an avian disease in infectious bronchitis-vaccinated chickens in china have led to the characterization of coronaviral isolates q1, j2, and t3, which were isolated from proventricular tissues of the affected young layer flocks. serologic analysis revealed that they could induce high titers of infectious bronchitis virus (ibv) antibodies in inoculated specific-pathogen-free (spf) chickens in indirect enzyme-linked immunosorbent assay but were not neutralized by antisera specific to t ... | 2001 | 11417821 |
| spike glycoprotein cleavage recognition site analysis of infectious bronchitis virus. | the spike glycoprotein of infectious bronchitis virus (ibv), a coronavirus, is translated as a precursor protein (so), then cleaved into two subunits (s1 and s2) by host cell serine proteases. in this study, we compared the cleavage recognition site of 55 ibv isolates to determine if the cleavage recognition site sequence, which consists of five basic amino acid residues, correlates with host cell range, serotype, geographic origin, and pathogenicity as it does in orthomyxoviruses and paramyxovi ... | 2001 | 11417816 |
| study of protection by recombinant fowl poxvirus expressing c-terminal nucleocapsid protein of infectious bronchitis virus against challenge. | a stable recombinant fowl poxvirus (rfpv) expressing the c-terminal region (119 amino acids) of the nucleocapsid (n) protein of an infectious bronchitis virus (ibv) strain ch3 was constructed by inserting the coding sequence within the thymidine kinase gene of fowl poxvirus (fpv) by homologous recombination. the n protein was expressed under control of the vaccinia virus promoter p7.5 in chicken embryo fibroblast cell cultures as seen in immunofluorescence assay and in rfpv-inoculated specific-p ... | 2001 | 11417813 |
| induction of caspase-dependent apoptosis in cultured cells by the avian coronavirus infectious bronchitis virus. | avian coronavirus infectious bronchitis virus (ibv) is the causative agent of chicken infectious bronchitis, an acute, highly contagious viral respiratory disease. replication of ibv in vero cells causes extensive cytopathic effects (cpe), leading to destruction of the entire monolayer and the death of infected cells. in this study, we investigated the cell death processes during acute ibv infection and the underlying mechanisms. the results show that both necrosis and apoptosis may contribute t ... | 2001 | 11413307 |
| nucleocapsid protein gene sequence analysis reveals close genomic relationship between turkey coronavirus and avian infectious bronchitis virus. | antibodies to infectious bronchitis virus (ibv) cross-react with turkey coronavirus (tcv) in immunofluorescence assay (ifa) indicating that ibv and tcv may share an amino acid sequence similarity. to determine its extent, the gene encoding the nucleocapsid (n) protein of tcv was amplified by reverse transcription-pcr (rt-pcr) from rna purified from intestines of embryos of turkeys infected with various tcv isolates and from allantoic fluid of chicken embryos infected with ibv m41 strain, the obt ... | 2001 | 11394575 |
| maternal antibody to infectious bronchitis virus: its role in protection against infection and development of active immunity to vaccine. | chicks hatched with high levels of maternal antibody had excellent protection (>95%) against infectious bronchitis virus (ibv) challenge at 1 day of age, but not at 7 days (<30%). this protection significantly (p<0.05) correlated with levels of local respiratory antibody and not with serum antibody.a high percentage of both maternal antibody-positive (mab+) and maternal antibody-negative (mab-) chicks failed to produce ibv antibody when vaccinated at 1 day of age by the intraocular route. in add ... | 2001 | 11356248 |
| the exacerbating effect of infectious bronchitis virus infection on the infectious bursal disease virus-induced suppression of opsonization by escherichia coil antibody in chickens. | chickens infected with infectious bronchitis virus (ibv) and infectious bursal disease virus (ibdv) commonly develop secondary infection of the respiratory tract with escherichia coli, resulting in significant economic losses. to understand the host factors that may contribute to the e. coli infection, we investigated macrophage-mediated e. coli phagocytosis, intracellular bacterial killing, and development of opsonizing antibody in previously uninfected chickens and in those infected with ibv, ... | 2001 | 11332499 |
| molecular epidemiology of infectious bronchitis virus isolates from china and southeast asia. | in order to trace the origin and evolution of avian infectious bronchitis virus (ibv) isolates in china and southeast asia, genomic sequencing was used for molecular characterization of 24 ibv isolates and two reference strains in comparison with the published sequences. the 5' region of the s1 genes, containing hypervariable regions i and ii, and 3' region of the nucleocapsid genes, containing cytotoxic t lymphocyte epitopes, were used to construct phylogenetic trees for analysis. the results s ... | 2001 | 11332484 |
| identification and analysis of the georgia 98 serotype, a new serotype of infectious bronchitis virus. | twenty-five field infectious bronchitis viruses (ibvs) similar to, but genetically distinct from, the de072 serotype were isolated from several states in the united states from 1990 through 1999 and were examined molecularly and antigenically. a 421-bp sequence in the hypervariable region of the s1 gene was examined, and phylogenetic analysis on that region indicated that these viruses are closely related but fall into unique groups. cross-virus neutralization testing and entire s1 sequence anal ... | 2001 | 11332478 |
| baculovirus expression of turkey coronavirus nucleocapsid protein. | the nucleocapsid (n) gene of turkey coronavirus (tcv) was amplified by reverse transcriptase-polymerase chain reaction, cloned, and expressed in the baculovirus expression system. a recombinant baculovirus containing the tcv n gene (rbtcv/n) was identified by polymerase chain reaction and expression of tcv n protein as determined by western immunoblot analysis. two tcv-specific proteins, 52 and 43 kda, were expressed by rbtcv/n; one of these proteins, p52, was comparable in size to native tcv n ... | 2001 | 11332474 |
| the missing link in coronavirus assembly. retention of the avian coronavirus infectious bronchitis virus envelope protein in the pre-golgi compartments and physical interaction between the envelope and membrane proteins. | one missing link in the coronavirus assembly is the physical interaction between two crucial structural proteins, the membrane (m) and envelope (e) proteins. in this study, we demonstrate that the coronavirus infectious bronchitis virus e can physically interact, via a putative peripheral domain, with m. deletion of this domain resulted in a drastic reduction in the incorporation of m into virus-like particles. immunofluorescent staining of cells coexpressing m and e supports that e interacts wi ... | 2001 | 11278557 |
| spike gene analysis of the de072 strain of infectious bronchitis virus: origin and evolution. | the entire s2 gene of the de072 strain of infectious bronchitis virus (ibv) was sequenced. the nucleotide and amino acid sequence was most similar to the d1466 strain and was 84.8% and 89.9% identity, respectively. the nucleotide and amino acid sequence similarity among the de072 strain and other ibv strains was less than 71.9% and 76.6%, respectively. phylogenetic analysis, based on both nucleotide and amino acid sequence, showed that ibv isolates were divided into two distinct groups. the de07 ... | 2001 | 11210943 |
| characterization of mexican strains of avian infectious bronchitis isolated during 1997. | ten infectious bronchitis virus (ibv) isolates were recovered from broiler chickens in the states of queretaro and guanajuato in mexico. the viruses were isolated from trachea, lung, kidney, and cecal tonsils of birds that showed respiratory signs in spite of vaccination with massachusetts (mass) and connecticut strains of ibv. each isolate was identified by an accession number from 1 to 10. six of the isolates were neutralized by mass monoclonal antibodies, whereas the other four were not. in a ... | 2000 | 11195651 |
| experimental escherichia coli respiratory infection in broilers. | this study determined optimal conditions for experimental reproduction of colibacillosis by aerosol administration of avian pathogenic escherichia coli to 2-to-4-wk-old broiler chickens. the basic model for reproducing disease was intranasal administration of approximately 10(4) mean embryo infectious dose of infectious bronchitis virus (ibv) followed by aerosol administration of an 02 or an 078 strain of e. coli in a horsfall unit (100 ml of a suspension of 10(9) colony-forming units/ml over 40 ... | 2000 | 11195629 |
| molecular characterization of an infectious bronchitis virus strain isolated from an outbreak in vaccinated layers. | an infectious bronchitis virus (ibv) strain ct/7852/97 was isolated from a commercial layer flock experiencing decreased egg production and poor egg quality. reciprocal virus neutralization test demonstrated that the isolate was closely related to massachusetts, arkansas, and jmk. with the use of both reverse transcription-polymerase chain reaction-restriction fragment length polymorphism and multiplex polymerase chain reaction methods, results consistently showed that ct/7852/97 isolate was mas ... | 2000 | 11195625 |
| serological monitoring on layer farms with specific pathogen-free chickens. | to monitor the existence of avian pathogens in laying chicken flocks, specific pathogen-free (spf) chickens were introduced into two layer farms and reared with laying hens for 12 months. spf chickens were bled several times after their introduction and examined for their sero-conversion to avian pathogens. as a result, antibodies to eight or ten kinds of pathogens were detected in spf chickens on each farm. antibodies to infectious bronchitis virus (ibv), avian nephritis virus, mycoplasma galli ... | 2000 | 11193353 |
| effect of liquid paraffin on antibody responses and local adverse reactions of bivalent oil adjuvanted vaccines containing newcastle disease virus and infectious bronchitis virus. | effects of liquid paraffin on antibody responses and local adverse reactions after intramuscular injection of oil adjuvanted vaccines containing newcastle disease (nd) and infectious bronchitis (ib) virus were investigated in chickens. each vaccine was prepared with a liquid paraffin such as carnation, crystol 52 and lytol. these vaccines induced sustained antibody responses against nd and ib. among local adverse reactions, lytol induced granulomatous reactions and abscesses, but carnation and c ... | 2000 | 11193350 |
| a serological survey for avian infectious bronchitis virus and newcastle disease virus antibodies in backyard (free-range) village chickens in mexico. | the commercial flocks in yucatan, mexico are free of newcastle disease virus (ndv) in its velogenic viscerotropic form, but little is known about the disease status of backyard poultry. a seroprevalence survey in 30 villages using haemagglutination inhibition (hi) tests for infectious bronchitis virus (ibv) and ndv antibodies was carried out from december 1997 to june 1998. the seroprevalences were 56.5% (95% ci 50-63%) for ibv and 2.2% (95% ci 0.5-3.8%) for ndv. all the villages had chickens th ... | 2000 | 11147278 |
| the coronavirus infectious bronchitis virus nucleoprotein localizes to the nucleolus. | the coronavirus nucleoprotein (n) has been reported to be involved in various aspects of virus replication. we examined by confocal microscopy the subcellular localization of the avian infectious bronchitis virus n protein both in the absence and in the context of an infected cell and found that n protein localizes both to the cytoplasmic and nucleolar compartments. | 2001 | 11119619 |
| cis-acting sequences required for coronavirus infectious bronchitis virus defective-rna replication and packaging. | the parts of the rna genome of infectious bronchitis virus (ibv) required for replication and packaging of the rna were investigated using deletion mutagenesis of a defective rna (d-rna) cd-61 (6.1 kb) containing a chloramphenicol acetyltransferase reporter gene. a d-rna with the first 544, but not as few as 338, nucleotides (nt) of the 5' terminus was replicated; the 5' untranslated region (utr) comprises 528 nt. region i of the 3' utr, adjacent to the nucleocapsid protein gene, comprised 212 n ... | 2001 | 11119581 |
| antigen quantification as in vitro alternative for potency testing of inactivated viral poultry vaccines. | routine batch control of licensed inactivated viral vaccines for poultry usually includes a potency assay as a measure of vaccine efficacy. potency assays often consist of vaccination-challenge experiments in the target species or in laboratory animals. instead of measuring the protection of vaccinated animals against virulent pathogens, the serological response after vaccination can be quantified for some vaccines. in vitro antigen quantification assays would be attractive alternatives for the ... | 2000 | 11087135 |
| evidence of genetic diversity generated by recombination among avian coronavirus ibv. | previously, we demonstrated that the de072 strain of ibv is a recombinant which has an ibv strain d1466-like sequence in the s gene. herein, we analyzed the remaining 3.8 kb 3' end of the genome, which includes gene 3, gene 4, gene 5, gene 6, and the 3' non-coding region of the de072 and d1466 strains. those two viruses had high nucleotide similarity in gene 4. however, the other individual genes had a much different level of sequence similarity with the same gene of the other ibv strains. the g ... | 2000 | 11087096 |
| utilizing fowlpox virus recombinants to generate defective rnas of the coronavirus infectious bronchitis virus. | coronavirus defective rnas (d-rnas) have been used as rna vectors for the expression of heterologous genes and as vehicles for reverse genetics by modifying coronavirus genomes by targetted recombination. d-rnas based on the avian coronavirus infectious bronchitis virus (ibv) d-rna cd-61 have been rescued (replicated and packaged into virions) in a helper virus-dependent manner following electroporation of in vitro-generated t7 transcripts into ibv-infected cells. in order to increase the effici ... | 2000 | 11086116 |
| redesign of primer and application of the reverse transcriptase-polymerase chain reaction and restriction fragment length polymorphism test to the de072 strain of infectious bronchitis virus. | diagnosis of the de072 strain of infectious bronchitis virus (ibv) by the reverse transcriptase-polymerase chain reaction (rt-pcr) and restriction fragment length polymorphism (rflp) serotype identification test was not possible because the primer used in the rt-pcr did not amplify the s1 gene of the de072 strain. the 3' end of the polymerase gene and the 5' end of the s2 gene of the de072 strain were sequenced and compared with the forward and reverse rt-pcr primers, respectively. a 2-bp mismat ... | 2000 | 11007014 |
| characterization of infectious bronchitis viruses isolated from outbreaks of disease in commercial flocks in brazil. | fifteen isolations of infectious bronchitis (ib) virus were made from a total of 126 brazilian poultry flocks of all ages that were examined. these flocks (14 chicken and 1 quail) were experiencing a variety of ib-like conditions including respiratory disease, digestive and kidney problems, and drops in egg production. one of the isolates was of the massachusetts serotype. the remainder were examined by means of cross-neutralization tests in tracheal organ cultures and were shown to belong to at ... | 2000 | 11007005 |
| emergence of subtype strains of the arkansas serotype of infectious bronchitis virus in delmarva broiler chickens. | infectious bronchitis virus (ibv) field isolates of the arkansas (ark) serotype were identified by reverse transcription-polymerase chain reaction (rt-pcr) as the most common serotype isolated from 1993 to 1997. these isolates were recovered from broiler flocks with respiratory disease raised on the delmarva peninsula in spite of ark vaccination in the region. for the purposes of investigating this apparently paradoxical finding, five rt-pcr ark-positive field isolates recovered in 1995 and 1996 ... | 2000 | 11007004 |
| protective immunity to infectious bronchitis in broilers vaccinated against marek's disease either in ovo or at hatch and against infectious bronchitis at hatch. | two experiments were conducted using commercial broiler chickens to determine if marek's disease (md) vaccines hvt/sb-1 and hvt plus cvi-988 given either in ovo or at hatch adversely affected the efficacy of infectious bronchitis (ib) vaccines (ark and mass serotypes) given by eyedrop on the day of hatch. nonvaccinated negative controls and controls that received only ib vaccines were included in each study. birds were challenged with either infectious bronchitis virus (ibv) mass-41 or ibv ark-9 ... | 2000 | 11007000 |
| morphologic observations on respiratory tracts of chickens after hatchery infectious bronchitis vaccination and formaldehyde fumigation. | the histologic changes in the respiratory tracts of chickens were evaluated after hatchery fumigation with 40% formaldehyde vapors and vaccination against infectious bronchitis virus with live attenuated vaccine (massachusetts serotype). one-day-old chickens were housed in four isolation units in controlled environmental conditions, fed and watered ad libitum, and separated into four groups: 1) fumigated and vaccinated birds (fv group); 2) nonfumigated and vaccinated birds (nfv group); 3) fumiga ... | 2000 | 11006997 |
| detection of antibody to turkey coronavirus by antibody-capture enzyme-linked immunosorbent assay utilizing infectious bronchitis virus antigen. | an antibody-capture enzyme-linked immunosorbent assay (elisa) for detection of antibody to turkey coronavirus (tcv) utilizing infectious bronchitis virus (ibv) antigen was developed. anti-tcv hyperimmune turkey serum and normal turkey serum were used as positive or negative control serum for optimization of the elisa system. goat anti-turkey immunoglobulin g (light plus heavy chains) conjugated with horseradish peroxidase was used as detector antibody. the performance of the elisa system was eva ... | 2000 | 11006996 |
| avian infectious bronchitis virus. | infectious bronchitis virus (ibv) is prevalent in all countries with an intensive poultry industry, with the incidence of infection approaching 100% in most locations. vaccination is only partially successful due to the continual emergence of antigenic variants. at many sites, multiple antigenic types are simultaneously present, requiring the application of multiple vaccines. although many countries share some common antigenic types, ibv strains within a geographic region are unique and distinct ... | 2000 | 10935276 |
| increased tracheal colonization in chickens without impairing pathogenic properties of avian pathogenic escherichia coli mt78 with a fimh deletion. | several studies suggest that the expression of f1 fimbriae could be involved in the virulence of escherichia coli for chickens. f1 fimbriae display multivalent properties such as adhesion to epithelia or interaction with the immune system that imply specific interactions between the adhesin fimh and different cell receptors. we constructed a delta fimh mutant of the avian pathogenic e. coli mt78 and evaluated its in vivo colonization and pathogenicity, as compared to that of the parent strain. t ... | 2000 | 10879915 |
| identification of avian infectious bronchitis virus by direct automated cycle sequencing of the s-1 gene. | direct automated cycle sequencing (dacs) of a reverse transcription-polymerase chain reaction (rt-pcr) product of the s-1 subunit of the spike peplomer gene was used to identify infectious bronchitis virus (ibv) serotypes. degenerate primers ck4 and ck2, utilized previously in our laboratory, were selected for dacs because they successfully amplify a wide range of serotypes represented by various reference strains and field isolates and the resulting polymerase chain reaction (pcr) product conta ... | 2000 | 10879913 |
| further characterization of the coronavirus infectious bronchitis virus 3c-like proteinase and determination of a new cleavage site. | coronavirus infectious bronchitis virus (ibv) encodes a trypsin-like proteinase (3c-like proteinase) by orf 1a, which has been demonstrated to play a pivotal role in proteolytic processing of gene 1-encoded polyproteins. in our previous studies, the proteinase was identified as a 33-kda protein in ibv-infected cells, and its catalytic center was shown to consist of h(2820) and c(2922) residues. it is released from the 1a and 1a/1b polyproteins by autoprocessing at two q-s dipeptide bonds (q(2779 ... | 2000 | 10873746 |
| localization of linear b-cell epitopes on infectious bronchitis virus nucleocapsid protein. | the nucleocapsid (n) protein of many viruses is highly conserved, immunogenic, and abundantly expressed during infection. these features make it a suitable candidate for diagnostic applications. the nucleocapsid protein of infectious bronchitis virus (ibv) was dissected into 12 fragments and expressed in escherichia coli. sera against australia t, china ch5, singapore p4, usa m41 and china t3 isolates were used to study the conservation and localization of the antigenic region on the ibv nucleoc ... | 2000 | 10865148 |
| expression of reporter genes from the defective rna cd-61 of the coronavirus infectious bronchitis virus. | the defective rna (d-rna) cd-61, derived from the beaudette strain of the avian coronavirus infectious bronchitis virus (ibv), was used as an rna vector for the expression of two reporter genes, luciferase and chloramphenicol acetyltransferase (cat). d-rnas expressing the cat gene were demonstrated to be capable of producing cat protein in a helper-dependent expression system to about 1.6 microgram per 10(6) cells. the reporter genes were expressed from two different sites within the cd-61 seque ... | 2000 | 10859373 |
| kinetics of lymphocytic subsets in chicken tracheal lesions infected with infectious bronchitis virus. | the kinetics of t-cells (cd3 positive (+), cd4+ and cd8+ cells) and b-cells (igg+, igm+ and iga+ cells) in chicken trachea were studied immunohistochemically and histopathologically following an intratracheal inoculation of infectious bronchitis virus (ibv). viral antigen was detected in the cytoplasm of tracheal epithelium from 16 hr to 6 days post-inoculation (p.i.) with a peak on 4 days p.i. a few igg+, igm+ and iga+ cells were detected in the submucosa from 8 hr p.i. thereafter igg+ and igm+ ... | 2000 | 10823726 |
| the amino and carboxyl domains of the infectious bronchitis virus nucleocapsid protein interact with 3' genomic rna. | previous studies indicated that the nucleocapsid (n) protein of infectious bronchitis virus (ibv) interacted with specific sequences in the 3' non-coding region of ibv rna. in order to identify domains in the n protein that bind to rna, the whole protein (409 amino acids) and six overlapping fragments were expressed as fusion polypeptides with six histidine-tags. using gel shift assays, the intact n protein and amino polypeptides, from residues 1 to 171 and residues 1 to 274, and carboxyl polype ... | 2000 | 10773316 |
| structure, stability and function of rna pseudoknots involved in stimulating ribosomal frameshifting. | programmed -1 ribosomal frameshifting has become the subject of increasing interest over the last several years, due in part to the ubiquitous nature of this translational recoding mechanism in pathogenic animal and plant viruses. all cis-acting frameshift signals encoded in mrnas are minimally composed of two functional elements: a heptanucleotide "slippery sequence" conforming to the general form x xxy yyz, followed by an rna structural element, usually an h-type rna pseudoknot, positioned an ... | 2000 | 10764589 |
| infectious bronchitis virus e protein is targeted to the golgi complex and directs release of virus-like particles. | the coronavirus e protein is a poorly characterized small envelope protein present in low levels in virions. we are interested in the role of e in the intracellular targeting of infectious bronchitis virus (ibv) membrane proteins. we generated a cdna clone of ibv e and antibodies to the e protein to study its cell biological properties in the absence of virus infection. we show that ibv e is an integral membrane protein when expressed in cells from cdna. epitope-specific antibodies revealed that ... | 2000 | 10756047 |
| relationship between serotypes and genotypes based on the hypervariable region of the s1 gene of infectious bronchitis virus. | to group infectious bronchitis virus (ibv) isolates, a genetic grouping method based on hypervariable region 1 (hvr 1, nucleotides 168 to 197) was compared with that based on the whole s1 gene. both methods resulted in the same grouping data. so the grouping method based on hvr 1 could represent the grouping method based on the whole s1 gene. taiwan isolates could not be placed within the existing groups. in order to test the correlation between genotype and serotype, a one-way neutralization te ... | 2000 | 10752554 |
| a rapid-plate hemagglutination assay for the detection of infectious bronchitis virus. | a rapid-plate hemagglutination (ha) test to detect infectious bronchitis virus (ibv) in allantoic fluid of embryonated eggs was introduced into routine procedures for ibv identification. this system was tested in 468 diagnostic cases received by the poultry diagnostic and research center at the university of georgia. allantoic fluids from inoculated embryos were harvested and treated with commercially available neuraminidase enzyme. ibv in neuraminidase-treated allantoic fluid was identified by ... | 2000 | 10737649 |
| genetic relationships of infectious bronchitis virus isolates from mississippi broilers. | a 582-base pair segment located in the nucleocapsid protein terminal part of the s1 gene of 26 arkansas (ark)-type infectious bronchitis virus (ibv) isolates from mississippi broilers was amplified and sequenced. reverse transcription-polymerase chain reaction and cycle sequencing techniques were used to elucidate the genetic and deduced amino acid relationships among the isolates. analysis suggested that the nucleotide and amino acid sequences of the isolates were highly conserved, with greater ... | 2000 | 10737646 |
| characterization of the stunting syndrome agent: relatedness to known viruses. | an enteric disease of young turkeys, referred to as stunting syndrome (ss), causes reduced growth and impaired feed efficiency. a recently isolated virus, stunting syndrome agent, (ssa) has been found to be the etiologic agent of ss. the objective of the present study was to determine relatedness of the ssa with other viral agents. serologic (viral neutralization and enzyme-linked immunosorbent assay [elisa]) assays and a reverse transcriptase-polymerase chain reaction (rt-pcr) were used. the an ... | 2000 | 10737643 |
| adoptive transfer of infectious bronchitis virus primed alphabeta t cells bearing cd8 antigen protects chicks from acute infection. | infectious bronchitis virus (ibv) infection and associated illness may be dramatically modified by passive transfer of immune t lymphocytes. lymphocytes collected 10 days postinfection were transferred to naive chicks before challenge with virus. as determined by respiratory illness and viral load, transfer of syngeneic immune t lymphocytes protected chicks from challenge infection, whereas no protection was observed in the chicks receiving the mhc compatible lymphocytes from uninfected chicks. ... | 2000 | 10725210 |
| epithelial cell kinetics in the inflammatory process of chicken trachea infected with infectious bronchitis virus. | all stages of degeneration and regeneration in chicken tracheal epithelium were studied morphologically following an intratracheal inoculation of infectious bronchitis virus (ibv). viral antigen was detected in the cytoplasm of tracheal epithelium from 1 to 7 days post-inoculation (d.p.i.) with a peak on 3 d.p.i. at 1 d.p.i., almost all epithelial cells were involved in the degeneration. at this time, labelling index of bromodeoxyuridine (brdu) in the basal cells showed significantly high value ... | 2000 | 10720181 |
| avian infectious bronchitis virus: isolation of an apparently new variant in italy. | 2000 | 10718592 | |
| cytotoxic t lymphocytes are critical in the control of infectious bronchitis virus in poultry. | various strains of infectious bronchitis virus (ibv) cause respiratory, kidney, enteric and reproductive illnesses in chickens, especially in newly hatched chicks. assays have been developed to identify gray strain ibv-specific cytotoxic t lymphocyte (ctl) responses using viral infected antigen presenting cells (apc) and using the semliki forest virus vector infected apc expressing individual viral polypeptides. it was shown that major histocompatibility complex restricted ctl are responsible fo ... | 2000 | 10717287 |
| performance of an rt-nested pcr elisa for detection of newcastle disease virus. | a sensitive and specific rt-nested pcr coupled with an elisa detection system for detecting newcastle disease virus is described. two nested pairs of primer which were highly specific to all the three different pathotypes of ndv were designed from the consensus fusion gene sequence. no cross-reactions with other avian infectious agents such as infectious bronchitis virus, infectious bursal disease virus, influenza virus, and fowl pox virus were observed. based on agarose electrophoresis detectio ... | 2000 | 10713378 |
| leader switching occurs during the rescue of defective rnas by heterologous strains of the coronavirus infectious bronchitis virus. | a defective rna (d-rna), cd-61, derived from the beaudette strain of the avian coronavirus infectious bronchitis virus (ibv), was rescued (replicated and packaged) using four heterologous strains of ibv as helper virus. sequence analysis of the genomic rna from the four heterologous ibv strains (m41, h120, hv10 and d207) identified nucleotide differences of up to 17% within the leader sequence and up to 4.3% within the whole of the adjacent 5' untranslated region (utr). analysis of the 5' ends o ... | 2000 | 10675417 |
| identification of a novel cleavage activity of the first papain-like proteinase domain encoded by open reading frame 1a of the coronavirus avian infectious bronchitis virus and characterization of the cleavage products. | the coronavirus avian infectious bronchitis virus (ibv) employs polyprotein processing as a strategy to express its gene products. previously we identified the first cleavage event as proteolysis at the gly(673)-gly(674) dipeptide bond mediated by the first papain-like proteinase domain (plpd-1) to release an 87-kda mature protein. in this report, we demonstrate a novel cleavage activity of plpd-1. expression, deletion, and mutagenesis studies showed that the product encoded between nucleotides ... | 2000 | 10644337 |
| the q-base of asparaginyl-trna is dispensable for efficient -1 ribosomal frameshifting in eukaryotes. | the frameshift signal of the avian coronavirus infectious bronchitis virus (ibv) contains two cis-acting signals essential for efficient frameshifting, a heptameric slippery sequence (uuuaaac) and an rna pseudoknot structure located downstream. the frameshift takes place at the slippery sequence with the two ribosome-bound trnas slipping back simultaneously by one nucleotide from the zero phase (u uua aac) to the -1 phase (uuu aaa). asparaginyl-trna, which decodes the a-site codon aac, has the m ... | 2000 | 10623518 |
| sequence analysis of the turkey coronavirus nucleocapsid protein gene and 3' untranslated region identifies the virus as a close relative of infectious bronchitis virus. | the 3' end of the turkey coronavirus (tcv) genome (1740 bases) including the nucleocapsid (n) gene and 3' untranslated region (utr) were sequenced and compared with published sequences of other avian and mammalian coronaviruses. the deduced sequence of the tcv n protein was determined to be 409 amino acids with a molecular mass of approximately 45 kda. the tcv n protein was identical in size and had greater than 90% amino acid identity with published n protein sequences of infectious bronchitis ... | 1999 | 10581391 |
| csiro's 'natural' vaccines. | 1999 | 10561787 | |
| infectious bronchitis virus s2 gene sequence variability may affect s1 subunit specific antibody binding. | the s2 gene of several strains of infectious bronchitis virus (ibv) belonging to the arkansas, connecticut, and florida serotypes was sequenced. phylogenetic analysis of the s2 gene nucleotide and deduced amino acid sequence data resulted in groups of strains that were the same as groupings observed when s1 sequence data was used. thus, it appears that s2 subunits are conserved within a serotype but not between serotypes. although the sequence differences were small, we found that only a few ami ... | 1999 | 10541018 |
| serum levels of chicken mannan-binding lectin (mbl) during virus infections; indication that chicken mbl is an acute phase reactant. | mannan-binding lectin (mbl) is a serum collectin which is believed to be an opsonin of the innate immune defence against various microorganisms. mbl is a minor acute phase reactant in man. we investigated the concentration of serum mbl in chickens infected with infectious bronchitis virus (ibv) and infectious laryngotracheitis virus (iltv). the concentration of serum mbl increased about twofold (from approximately 6 to 12 microg/ml) due to these viral infections. the concentration peaked 3-7 day ... | 1999 | 10507370 |
| a reverse transcription-polymerase chain reaction assay for the detection of avian pneumovirus (colorado strain). | a reverse transcription-polymerase chain reaction assay was developed for the detection of avian pneumovirus (colorado strain) (apv-col). the specific primers were designed from the published sequence of the matrix protein gene of apv-col. the primers amplified a product of 631 nucleotides from apv-col. the assay identified only apv-col and did not react with newcastle disease virus and infectious bronchitis virus. | 1999 | 10494434 |
| comparison of the immunofluorescent assay and reverse transcription-polymerase chain reaction to detect and type infectious bronchitis virus. | indirect fluorescent antibody (ifa) assay and reverse transcription-polymerase chain reaction (rt-pcr) are two current methods commonly used for the detection of infectious bronchitis virus (ibv) and its serotypes. the objectives of this study were to compare the two methods relative to detecting ibv in chicken embryos that were artificially inoculated with mass41, ark99, or mass41/ark99 in serial embryo passages and in tracheas and cecal tonsils collected from vaccinated commercial flocks with ... | 1999 | 10494432 |
| a liquid phase blocking elisa for the detection of antibodies against infectious bronchitis virus. | a liquid phase blocking elisa (lpb-elisa) was developed for the detection and measurement of antibodies against infectious bronchitis virus (ibv). the purified and nonpurified virus used as antigen, the capture and detector antibodies, and the chicken hyperimmune sera were prepared and standardized for this purpose. a total of 156 sera from vaccinated and 100 from specific pathogen-free chickens with no recorded contact with the virus were tested. the respective serum titers obtained in the seru ... | 1999 | 10412553 |
| development of a nested pcr assay for the detection of canine coronavirus. | a diagnostic test for canine coronavirus (ccv) infection based on a nested polymerase chain reaction (n-pcr) assay was developed and tested using the following coronavirus strains: ccv (usda strain), ccv (45/93, field strain), feline infectious peritonitis virus (fipv, field strain), transmissible gastroenteritis virus (tgev, purdue strain), bovine coronavirus (bcv, 9wbl-77 strain), infectious bronchitis virus (ibv, m-41 strain) and fecal samples of dogs with ccv enteritis. a 230-bp segment of t ... | 1999 | 10403671 |
| sequence analysis of the matrix/nucleocapsid gene region of turkey coronavirus. | a reverse transcriptase, polymerase chain reaction (rt-pcr) procedure was used to amplify a segment of the genome of turkey coronavirus (tcv) spanning portions of the matrix and nucleocapsid (mn) protein genes (approximately 1.1 kb). the mn gene region of three epidemiologically distinct tcv strains (minnesota, nc95, indiana) was amplified, cloned into puc19, and sequenced. tcv mn gene sequences were compared with published sequences of other avian and mammalian coronaviruses. a high degree of s ... | 1999 | 10393500 |
| phylogenetic analysis of a highly conserved region of the polymerase gene from 11 coronaviruses and development of a consensus polymerase chain reaction assay. | viruses in the genus coronavirus are currently placed in three groups based on antigenic cross-reactivity and sequence analysis of structural protein genes. consensus polymerase chain reaction (pcr) primers were used to obtain cdna, then cloned and sequenced a highly conserved 922 nucleotide region in open reading frame (orf) 1b of the polymerase (pol) gene from eight coronaviruses. these sequences were compared with published sequences for three additional coronaviruses. in this comparison, it ... | 1999 | 10392726 |
| activity of a purified his-tagged 3c-like proteinase from the coronavirus infectious bronchitis virus. | previous studies in vitro of the processing of cloned polyprotein fragments from the coronavirus infectious bronchitis virus (ibv) large open reading frame (orf1), confirmed the activity of a predicted 3c-like proteinase (3clp) domain and suggested that the proteinase is released autocatalytically from the polyprotein in the form of a 35 kda protein, 3clpro, capable of further cleavages in trans. in order to identify such cleavages within the orf1 polyprotein mediated by 3clpro, the proteinase w ... | 1999 | 10392722 |
| health evaluation of free-ranging rockhopper penguins (eudyptes chrysocomes) in argentina. | as part of annual colony counts in santa cruz province, argentina, a health survey of rockhopper penguins (eudyptes chrysocomes) was conducted in 1994. forty-five birds were examined during handling procedures, and blood and fecal samples were collected for laboratory analysis. all birds appeared to be in good condition. no ecto- or endoparasites were found. hematology, plasma chemistry, and plasma mineral levels were measured and correlated with the results of bacterial and viral serology. anti ... | 1999 | 10367640 |
| evidence for an rna pseudoknot loop-helix interaction essential for efficient -1 ribosomal frameshifting. | rna pseudoknots are structural elements that participate in a variety of biological processes. at -1 ribosomal frameshifting sites, several types of pseudoknot have been identified which differ in their organisation and functionality. the pseudoknot found in infectious bronchitis virus (ibv) is typical of those that possess a long stem 1 of 11-12 bp and a long loop 2 (30-164 nt). a second group of pseudoknots are distinguishable that contain stems of only 5 to 7 bp and shorter loops. the nmr str ... | 1999 | 10329145 |
| the role of rna pseudoknot stem 1 length in the promotion of efficient -1 ribosomal frameshifting. | the ribosomal frameshifting signal present in the genomic rna of the coronavirus infectious bronchitis virus (ibv) contains a classic hairpin-type rna pseudoknot that is believed to possess coaxially stacked stems of 11 bp (stem 1) and 6 bp (stem 2). we investigated the influence of stem 1 length on the frameshift process by measuring the frameshift efficiency in vitro of a series of ibv-based pseudoknots whose stem 1 length was varied from 4 to 13 bp in single base-pair increments. efficient fr ... | 1999 | 10329144 |
| serological evidence for a 793/b related avian infectious bronchitis virus in india. | 1999 | 10204229 | |
| coronavirus pneumonia following autologous bone marrow transplantation for breast cancer. | infectious bronchitis virus, otherwise known as coronavirus, can cause mild upper respiratory tract illnesses in children and adults. rarely has coronavirus been linked, either by serology or nasal wash, to pneumonia. we report a case of a young woman who, following treatment for stage iiia breast cancer using a high-dose chemotherapy regimen followed by autologous bone marrow and stem cell transplantation, developed respiratory failure and was found to have coronavirus pneumonia as diagnosed by ... | 1999 | 10084516 |
| a multiplex pcr for massachusetts and arkansas serotypes of infectious bronchitis virus. | infectious bronchitis virus (ibv), the prototype of the coronavirus family, is an enveloped, single-stranded rna virus with a genome size of approximately 27.6 kilobase. infectious bronchitis virus causes an acute, highly contagious respiratory and urogenital disease of chickens which results in significant economic losses in commercial broilers, layers and breeders. a rapid, highly sensitive and specific method is needed in the differential diagnosis of infections of different serotypes. a mult ... | 1999 | 10024427 |
| construction and characterization of avian escherichia coli cya crp mutants. | we constructed delta cya delta crp mutants of two avian septicemic escherichia coli strains and evaluated their attenuation in virulence. the p1 phage was used to transfer cya::tn10 from an e. coli k-12 strain into virulent avian o78 and o2 e. coli isolates. tetracycline-resistant transductants were plated on bochner-maloy medium, and tetracycline-sensitive colonies were selected, then tested by polymerase chain reaction to confirm that they had deletions of the cya gene. deletions of crp were c ... | 1998 | 9876838 |
| safety of a temperature-sensitive clone of mycoplasma synoviae as a live vaccine. | a temperature-sensitive (ts+) clone derived from the australian mycoplasma synoviae (ms) field isolate 86079/7ns was produced by chemical mutagenesis with n-methyl-n'-nitro-n-nitrosoguanidine and assessed for safety as a live vaccine. this clone, designated ms-h, was assessed for pathogenicity in three different models with air sac lesions as the criterion. no air sac lesions were observed when ms-h was administered to specific-pathogen-free hybrid white leghorn (hwl) chickens by eyedrop at 10 t ... | 1998 | 9876835 |
| efficacy of a temperature-sensitive mycoplasma synoviae live vaccine. | a temperature-sensitive clone of mycoplasma synoviae (ms), ms-h, derived from the chemical mutagenesis of the australian field isolate 86079/7ns, was investigated for efficacy as a live vaccine. titers of ms-h vaccine ranged between 1.16 x 10(8) and 8.4 x 10(8) color changing units/ml when incubated at 33 c and were consistently > or = 10(2) lower when incubated at 39.5 c. laboratory-produced ms-h vaccine protected 8 out of 10 specific-pathogen-free webster white leghorn chickens against a combi ... | 1998 | 9876834 |
| the early history of infectious bronchitis. | 1998 | 9876830 | |
| does ibv change slowly despite the capacity of the spike protein to vary greatly? | we have sequenced that part of the spike protein (s) gene which encodes the aminoterminal and most variable quarter (hypervariable region, hvr) of the s1 subunit of 28 isolates of the 793/b (also known as cr88 and 4/91) serotype of infectious bronchitis virus (ibv) and the whole of s1 for nine of them. the isolates were from france and britain between the years 1985 (first isolation) and 1996. the maximum nucleotide and amino acid differences between the first isolate and the others were 4.1% an ... | 1998 | 9782351 |
| utilising a defective ibv rna for heterologous gene expression with potential prophylactic application. | based on the natural ability of coronaviruses to undergo homologous rna recombination, we are working to produce infectious bronchitis virus (ibv) recombinants using rna generated from recombinant fowlpox viruses (fpv). the aim is to replace the spike (s) gene of an existing ibv vaccine strain with the s gene of a heterologous strain. cd-61 is an ibv defective rna (d-rna) derived from a naturally occurring ibv d-rna (cd-91). cd-61 d-rna is being investigated as an rna vector for the expression o ... | 1998 | 9782345 |
| pathogenesis of coronavirus-induced infections. review of pathological and immunological aspects. | coronaviruses and arteriviruses infect multiple species of mammals, including humans, causing diseases that range from encephalitis to enteritis. several of these viruses infect domestic animals and cause significant morbidity and mortality, leading to major economic losses. in this category are included such pathogens as transmissible gastroenteritis virus, porcine respiratory and reproductive virus and infectious bronchitis virus. the feline coronaviruses (fecv) generally do not cause infectio ... | 1998 | 9782322 |
| a monoclonal antibody blocking elisa for the detection of ibv antibodies in fowl. | a murine monoclonal antibody (mab) reacting with the spike protein of seven field and laboratory strains of infectious bronchitis virus (ibv) was characterised. neutralisation tests performed in chicken tracheal organ culture showed that the mab is directed against a conserved neutralising epitope. a monoclonal antibody blocking elisa (b-elisa) was developed based on the mab. the sensitivity and specificity of the test was evaluated by examining sera and egg yolk from ibv-free, vaccinated or nat ... | 1998 | 9782321 |
| cytotoxic t lymphocyte responses to infectious bronchitis virus infection. | cytotoxic t lymphocyte (ctl) activity to infectious bronchitis virus (ibv) was examined at regular intervals between 3 and 30 days post infection (p.i.). the maximal ctl lysis of target cells infected with ibv with 82% was detected at 10 days p.i. the specific ctl activity began to decrease only after viral loads, which peaked at day 8 p.i. in both kidneys and lungs, started to decline. therefore, the ctl response correlated with elimination of acute infection. igm antibody did not appear until ... | 1998 | 9782315 |
| regulation of mrna 1 expression by the 5'-untranslated region (5'-utr) of the coronavirus infectious bronchitis virus (ibv). | in this report, we show that expression of the coronavirus ibv mrna1 is regulated by its 5'-utr. evidence presented demonstrates that the ibv sequence from nucleotide 1 to 1904 directs very inefficient synthesis of a product of approximately 43 kda. deletion of either the first 362 bp or the whole part of the 5'-utr, however, dramatically increased the expression of the 43 kda protein species. the mechanisms involved were investigated by two different approaches. firstly, translation of the same ... | 1998 | 9782297 |
| rescue of ibv d-rna by heterologous helper virus strains. | coronavirus defective rna (d-rna) vectors could be developed to deliver selected genes for the production of recombinant coronavirus vaccines. an ibv d-rna, cd-61, derived from a naturally occurring ibv beaudette d-rna, cd-91, is being developed as a d-rna vector for ibv. in order to use cd-61 as a vector it will require rescue by heterologous strains in addition to beaudette. rescue will be determined by recognition of replication and packaging signals within the d-rna by the helper virus. the ... | 1998 | 9782290 |
| sequence elements involved in the rescue of ibv defective rna cd-91. | deletion mutagenesis has been used to identify essential regions for rescue of coronavirus defective rnas (d-rnas). using this technique on a cloned ibv d-rna cd-91, we have identified a region potentially important in its rescue. comparing the sequence of d-rnas rescued with those not rescued we have deduced that a 72 base region corresponding to base number 13,824 to 13,896 in the viral genome is required for rescue. this may be an ibv d-rna packaging signal or a cis-acting element involved in ... | 1998 | 9782289 |
| characterisation of a papain-like proteinase domain encoded by orf1a of the coronavirus ibv and determination of the c-terminal cleavage site of an 87 kda protein. | our previous studies have shown that two overlapping papain-like proteinase domains (plpds) encoded by the ibv sequence from nucleotides 4155 to 5550 is responsible for cleavage of the orf 1a polyprotein to an 87 kda protein. in this study, we demonstrate that only the more 5' one of the two domains, plpd-1 encoded between nucleotides 4155 and 5031, is required for processing to the 87 kda protein. site-directed mutagenesis studies have shown that the cys1274 and his1435 residues are essential f ... | 1998 | 9782279 |
| further characterisation of the coronavirus ibv orf 1a products encoded by the 3c-like proteinase domain and the flanking regions. | coronavirus ibv encodes a piconarvirus 3c-like proteinase. in a previous report, this proteinase was shown to undergo rapid degradation in vitro in reticulocyte lysate due to a posttranslational event involving ubiquitination of the protein. several lines of evidence presented here indicate that the proteinase itself is stable. translation of the ibv sequence from nucleotide 8864 to 9787 resulted in the synthesis of a 33 kda protein, representing the full-length 3c-like proteinase. pulse-chase a ... | 1998 | 9782278 |
| proteolytic processing of the polyprotein encoded by orf1b of the coronavirus infectious bronchitis virus (ibv). | we present here evidence demonstrating that four previously predicted q-s(g) cleavage sites, encoded by the ibv sequences from nucleotide 15,129 to 15,134, 16,929 to 16,934, 18,492 to 18,497, and 19,506 to 19,511, respectively, can be recognised and transcleaved by the 3c-like proteinase. five mature products with sizes of approximately 100 kda, 65 kda, 63 kda, 42 kda and 35 kda are released from the orf1b polyprotein by the 3c-like proteinase-mediated cleavage at these positions. meanwhile, exp ... | 1998 | 9782277 |
| sequence comparison of avian infectious bronchitis virus s1 glycoproteins of the florida serotype and five variant isolates from georgia and california. | the infectious bronchitis virus (ibv) spike glycoprotein s1 subunit is required to initiate infection and contains virus-neutralizing and serotype-specific epitope(s). reported are the s1 gene nucleotide and predicted amino acid sequences for the florida 18288 strain and isolates ga-92, cv-56b, cv-9437, cv-1686, and 1013. these sequences were compared with previously published gene sequences of ibv strains, and phylogenetic relationships are reported. the s1 amino acid sequence of florida 18288 ... | 1998 | 9778790 |
| isolation of georgia variant (georgia isolate 1992) infectious bronchitis virus but not ornithobacterium rhinotracheale from a kentucky broiler complex. | integrated broiler production operations in western kentucky have been very successful. the reason for this success includes the fact that flocks are free of many endemic diseases for a period of time, often years, because birds are raised in virgin, disease-free territory. this case report documents that importation of birds from an area with endemic georgia variant (ga-92) infectious bronchitis virus and ornithobacterium rhinotracheale (ort) bacterial infection resulted in introduction of ga-9 ... | 1998 | 9777165 |
| colonization ability and pathogenic properties of a fim- mutant of an avian strain of escherichia coli. | several studies suggest that the expression of type 1 fimbriae is involved in the virulence of escherichia coli in chickens, by promoting adhesion of bacteria to the respiratory tract, which is most probably the first step to occur in the infection, and by interacting with the immune response. in order to determine to what extent type 1 fimbriae were involved in the pathogenic process, the fim cluster of an avian pathogenic strain of e. coli, mt78 (o2:k1:h+), was modified in vitro and reintroduc ... | 1998 | 9766199 |
| immunosuppressive effect of cryptosporidium baileyi infection on vaccination against avian infectious bronchitis in chicks. | two-day-old commercial chicks were inoculated orally with 2 x 10(6) oocysts of cryptosporidium baileyi and vaccinated with 10(3.5) eid50/head of a commercially available avian infectious bronchitis (ib) live virus vaccine at 4 and 14 days following inoculation. chicks infected with c. baileyi were shown to have an immunosuppressive effect on ib virus. it is concluded that infection with the protozoon in early life may increase their susceptibility to ib. | 1998 | 9755592 |
| humoral and cell-mediated immunopotentiation in vaccinated chicken layers by thymic hormones and zinc. | the humoral and cell-mediated immunities to a trivalent killed vaccine, administered subcutaneously to white leghorn-chicken layers at 29 and 31 weeks of age, and containing antigens of infectious bronchitis virus (ibv), infectious bursal disease virus (ibdv), and newcastle disease virus (ndv), were quantitated in five vaccinated and one unvaccinated-control group. four out of the five vaccinated groups were immunopotentiated by various combinations of zinc and thymic hormones administered intra ... | 1998 | 9713942 |
| influence of inoculation site of combined oil-adjuvanted vaccine on the antibody response in chickens. | inactivated oil-adjuvanted vaccines for nd, ib, and ic serotypes a and c (oilvax nb2ac) have been marketed from 1993. in the outdoors, various inoculation sites have been used in chickens because to make the inoculation procedure easier. we examined whether differences would be obtained in the antibody response according to the inoculation sites; the subcutaneous inoculation into the back of the neck for oilvax use, and the thigh, lower thigh, breast and shoulder muscle for the possible applicat ... | 1998 | 9713811 |
| bacterial respiratory disease of poultry. | bacterial pathogens play an important role in causing respiratory disease in domestic poultry species. in many cases, the bacterial component of a respiratory disease colonizes the respiratory system only after a primary viral or environmental insult. colonization of the airsacs of a chicken by escherichia coli following an infectious bronchitis virus infection is an example of secondary bacterial invasion. in other cases, the bacterial component of the respiratory disease is the primary initiat ... | 1998 | 9706078 |