Publications
| Title | Abstract | Year Filter | PMID(sorted descending) Filter |
|---|
| protection of broiler breeders by an inactivated combined water-in-oil-in-water viral vaccine. | a four-component vaccine, prepared by combining the single vaccines, contains subunits of newcastle disease and infectious bronchitis viruses, as well as whole inactivated infectious bursal disease and egg drop syndrome viruses. the vaccine is prepared in the form of a low-viscosity water-in-oil-in-water emulsion with low mineral oil content. heavy breeders were vaccinated at the age of 20 weeks by intramuscular administration of 0.5 ml vaccine/bird in an experiment carried out under field condi ... | 1998 | 9704508 |
| identification of amino acids involved in a serotype and neutralization specific epitope within the s1 subunit of avian infectious bronchitis virus. | localization of neutralizing, serotype specific epitopes of infectious bronchitis virus has been difficult because these epitopes are conformationally dependent. we identified amino acids involved in a serotype specific, conformationally dependent epitope by analysis of the s1 gene of 13 monoclonal antibody-neutralization-resistant mutants. substitutions in the predicted amino acid sequence of these mutants were located at residues 304 and/or 386. most of the substitutions at residue 304 were fr ... | 1997 | 9672590 |
| proteolytic mapping of the coronavirus infectious bronchitis virus 1b polyprotein: evidence for the presence of four cleavage sites of the 3c-like proteinase and identification of two novel cleavage products. | we have previously reported that the 3c-like proteinase of the coronavirus infectious bronchitis virus (ibv) is responsible for processing of the 1a and 1a/1b polyproteins to three mature products of 24, 10, and 100 kda (liu et al., 1994, 1997; ng and liu, 1998). the c-terminal cleavage site of the 100-kda protein was defined to be the q891(1b)-s892(1b) dipeptide bond encoded by nucleotides 15,129 to 15,134 (liu and brown, 1995). in this report, other cleavage sites of the 3c-like proteinase in ... | 1998 | 9657947 |
| infectious bronchitis virus antibodies in tears and their relationship to immunity. | antibodies to infectious bronchitis virus (ibv) in chicken tears were investigated to determine if they could be used as an indicator of protective immunity. antibody production in tears and serum was measured by enzyme-linked immunosorbent assay (elisa) in specific-pathogen-free (spf) white leghorn and broiler chickens vaccinated with a live attenuated vaccine containing the massachusetts (mass) connaught strain of ibv. the effect of virulent infectious bursal disease virus (ibdv) infection on ... | 1998 | 9645328 |
| serotype identification of avian infectious bronchitis virus by rt-pcr of the peplomer (s-1) gene. | the s-1 peplomer gene sequences of 31 strains of avian coronavirus infectious bronchitis virus (ibv) from north america, europe, and australia were compared to identify common and unique regions for possible diagnostic applications. s-1 sequences that were conserved among serotypes and sequences that were variable between serotypes were identified. based on conserved s-1 gene sequences, "general" degenerate oligonucleotide primers were designed that amplified ibv genomic rna by the reverse trans ... | 1998 | 9645318 |
| genetic resistance to avian viruses. | viral infections of poultry can be catastrophic in terms of both welfare and economics, and although vaccines have been very successful in combating these diseases, new forms of viruses have evolved which present increasing difficulties for vaccine control. differences in genetic susceptibility are known to exist for many of the major viral pathogens of poultry. consequently, an increase in the level of genetic resistance provides a possible means of enhancing protection of flocks. this is parti ... | 1998 | 9638814 |
| characterization of the two overlapping papain-like proteinase domains encoded in gene 1 of the coronavirus infectious bronchitis virus and determination of the c-terminal cleavage site of an 87-kda protein. | in a previous report, we showed that proteolytic processing of an 87-kda mature viral protein from the coronavirus infectious bronchitis virus (ibv) 1a and 1a/1b polyproteins was mediated by two putative overlapping papain-like proteinase domains (plpds) encoded within the region from nucleotides 4243 to 5553 of orf 1a (liu et al., 1995). in this study, we demonstrate that only the first domain, plpd-1, is responsible for this cleavage, as deletion of the second domain did not affect the formati ... | 1998 | 9636369 |
| cloacal inoculation with the connecticut strain of avian infectious bronchitis virus: an attempt to produce nephropathogenic virus by in vivo passage using cloacal inoculation. | avian infectious bronchitis virus (ibv) strain connecticut a-5968 isolated from respiratory tissue of chickens in usa in the 1960s, is considered as representative of respiratory disease causing ibv strains. specific pathogen free chicks inoculated with the strain via the cloaca replicated the virus more rapidly in their kidneys than did chicks inoculated with the same virus intratracheally. virus passaged thirteen-times via the cloaca caused stronger nephrotropism and nephropathogenicity than t ... | 1998 | 9592724 |
| induction of protective immunity in chickens vaccinated with infectious bronchitis virus s1 glycoprotein expressed by a recombinant baculovirus. | a recombinant baculovirus containing the s1 glycoprotein gene of the virulent nephropathogenic km91 strain of infectious bronchitis virus (ibv) was constructed in order to investigate protective immunity in vaccinated chickens. results from the protection test were evaluated by re-isolation of virus from the kidneys and tracheas of vaccinated chickens after challenge with strain km91. after three immunizations, the recombinant s1 (rs1) glycoprotein induced 50% protection of the kidney, whilst in ... | 1998 | 9568966 |
| a common rna motif in the 3' end of the genomes of astroviruses, avian infectious bronchitis virus and an equine rhinovirus. | in the 3' non-coding region of the genomes of infectious bronchitis virus, an avian coronavirus and the picornavirus equine rhinovirus serotype 2, there is a motif with remarkable similarity, both in sequence and folding, to the second rna stem-loop from the 3' end of the genomes of human astroviruses. this motif was also found in astroviruses of sheep, pig and turkey, suggesting that it is a common feature of all astroviruses. the conserved nature of the motif indicates that there has been stro ... | 1998 | 9568965 |
| identification of a 24-kda polypeptide processed from the coronavirus infectious bronchitis virus 1a polyprotein by the 3c-like proteinase and determination of its cleavage sites. | we report here the identification of a 24-kda polypeptide in ibv-infected vero cells by immunoprecipitation with a region-specific antiserum raised in rabbits against the ibv sequence encoded between nucleotides 10,928 and 11,493. coexpression, deletion, and mutagenesis studies have demonstrated that this protein is encoded by orf 1a from nucleotide 10,915 to 11,544 and is released from the 1a polyprotein by the 3c-like proteinase-mediated proteolysis. a previously predicted q-s (q3462s3463) dip ... | 1998 | 9568037 |
| national surveillance of poultry diseases in lebanon. | from 1992 to mid-1996, a national survey of poultry diseases in lebanon was conducted. this surveillance included meat breeder, layer breeder, commercial layer and chicken broiler flocks. the history, signs, lesions and laboratory tests of poultry were used in the diagnosis of prevalent poultry diseases. culture techniques were used to screen for bacterial diseases; serological techniques and, to a lesser extent, culture techniques were used to diagnose viral diseases; and both serological and c ... | 1997 | 9567302 |
| detection and classification of infectious bronchitis viruses isolated in korea by dot-immunoblotting assay using monoclonal antibodies. | dot-immunoblotting assay (dia) using five monoclonal antibodies (mabs) to infectious bronchitis virus (ibv) was used to detect and classify the viruses propagated in embryonated chicken eggs. using a group-specific mab 3f5, 10 reference strains and 12 korean isolates of ibv were successfully detected by dia, and the lowest virus titer of ibv detected by dia was approximately less than 10(3.8) mean embryo infective dose/ml. for evaluating the diagnostic efficiency, dia was compared with the conve ... | 1998 | 9533085 |
| recombinant nucleocapsid protein is potentially an inexpensive, effective serodiagnostic reagent for infectious bronchitis virus. | the nucleocapsid protein of the gray strain of infectious bronchitis virus (ibv) is highly immunogenic and cross-reactive among various distinct serotypes. recombinant nucleocapsid polypeptide expressed in bacteria with a histidine tag at the amino terminus has been used as antigen for developing an assay to detect ibv-specific antibody. this fusion protein was produced readily in bacteria and easily purified with a nickel column which bound to the histidine tag. conditions were optimized for us ... | 1998 | 9506811 |
| protection by a commercial arkansas-type infectious bronchitis virus vaccine against a field isolate of the same serotype. | a late-breaking infectious bronchitis virus (ibv)-associated respiratory disease was a chronic problem in georgia broilers in 1995. the predominant virus isolated from diseased birds was the arkansas (ark) type of ibv. because broilers in georgia are currently vaccinated with the arkansas serotype, there was concern that a phenotypic and/or genotypic change had occurred in the field virus so it could break through immunity conferred by commercial vaccines. the purpose of this study was to determ ... | 1997 | 9454933 |
| comparison of the efficacies of three fluoroquinolone antimicrobial agents, given as continuous or pulsed-water medication, against escherichia coli infection in chickens. | this study compared the efficacy of continuous or pulsed-water medication with enrofloxacin, danofloxacin, and sarafloxacin in eight groups of 90 chicks each by using an infectious bronchitis virus-escherichia coli model of colisepticemia. the model produced lesions of typical those occurring in birds with severe colisepticemia; for the infected, nonmedicated birds the mortality was 43.5% and the morbidity was 89%, 17.8% of birds had severe lesions, and the birds had a mean air sac lesion score ... | 1998 | 9449265 |
| fragmentation of a golgi-localized chimeric protein allows detergent solubilization and reveals an alternate conformation of the cytoplasmic domain. | golgi resident proteins maintain their localization despite a continual protein and lipid flux through the organelle. to study golgi retention mechanisms, we have focused upon the chimeric protein gm1. this protein contains the golgi transmembrane domain targeting signal from the infectious bronchitis virus m protein and the lumenal and cytoplasmic domain of the vesicular stomatitis virus glycoprotein (vsv g). the gm1 protein is targeted to the golgi where it forms an unusually stable detergent- ... | 1998 | 9425038 |
| ceramide accumulation uncovers a cycling pathway for the cis-golgi network marker, infectious bronchitis virus m protein. | the m glycoprotein from the avian coronavirus, infectious bronchitis virus (ibv), contains information for localization to the cis-golgi network in its first transmembrane domain. we hypothesize that localization to the golgi complex may depend in part on specific interactions between protein transmembrane domains and membrane lipids. because the site of sphingolipid synthesis overlaps the localization of ibv m, we asked whether perturbation of sphingolipids affected localization of ibv m. short ... | 1997 | 9396747 |
| cytotoxic activity of cells recovered from the respiratory tracts of chickens inoculated with infectious bronchitis virus. | previously uninoculated control chickens and chickens exposed to infectious bursal disease virus (ibdv) at 1 day of age were intranasally exposed to the m41 strain of infectious bronchitis virus (ibv) at 5 wk of age. between 7 and 13 days after inoculation with ibv, cells were collected from the respiratory tracts of both groups of chickens and assayed for in vitro cytotoxic activity against a lymphoblastoid lscc-rp9 target cell line using a 4-hr 51chromium-release assay (cra). compared to thymo ... | 1997 | 9356717 |
| antigenic and s-1 genomic characterization of the delaware variant serotype of infectious bronchitis virus. | a previously unrecognized infectious bronchitis virus (ibv) serotype, referred to hereafter as the delaware variant (de var), was isolated from commercial broiler chickens during a severe, widespread respiratory disease epornitic in the delmarva peninsula region of the united states in january-march 1992. the de var serotype was found to be antigenically unrelated by virus-neutralization (vn) test to nine reference ibv serotypes from north america. additional vn tests indicated that the de var i ... | 1997 | 9356713 |
| pathogenicity of attenuated infectious bronchitis viruses for oviducts of chickens exposed in ovo. | a fixed effects, completely randomized factorial design was used to study the effect of infectious bronchitis virus (ibv) inoculation at two different exposure ages and three postinoculation (pi) durations on chick oviduct pathology. maternal antibody-positive chicken embryos at 18 days of embryonation (ed) and newly hatched chicks were inoculated with an ibv vaccine (v-ibv) or with an ibv vaccine that had been serially passaged 21 times in chick kidney tissue culture (p-ibv). hatchability of eg ... | 1997 | 9356705 |
| antigenic characterization of a turkey coronavirus identified in poult enteritis- and mortality syndrome-affected turkeys. | a turkey coronavirus (tcv [nc95]) was characterized by antigenic comparison with other avian and mammalian coronaviruses using immunofluorescence (fa) and immunoperoxidase (ip) procedures. based on fa and ip procedures, tcv (nc95) was determined to be antigenically indistinguishable from turkey enteric (bluecomb) coronavirus (tecv). in addition, tcv (nc95) and tecv were found to be closely related to infectious bronchitis virus (ibv); a one-way antigenic relationship was demonstrated. polyclonal ... | 1997 | 9356703 |
| systemic and local antibody responses to infectious bronchitis virus in chickens inoculated with infectious bursal disease virus and control chickens. | serum and local (respiratory) antibody responses to infectious bronchitis virus (ibv) were studied in 5-wk-old white leghorn-type control chickens and chickens inoculated with infectious bursal disease virus (ibdv) at 1 day of age. of the chickens inoculated with ibv alone, 93% had detectable levels of ibv antibodies in the sera and 87% had detectable antibodies in the respiratory lavage fluids. compared to this group, only 73% and 65% of ibdv-ibv inoculated chickens had serum and respiratory an ... | 1997 | 9356695 |
| effect of cytoxan-induced heteropenia on the response of specific-pathogen-free chickens to infectious bronchitis. | epithelial damage in infectious bronchitis occurs early in the disease process. heterophil infiltration into the tracheal mucosa is greatest at that time. to determine the contribution of heterophils to tracheal epithelial damage of infectious bronchitis, eight 3-wk-old specific-pathogen-free chickens were made heteropenic by four daily intramuscular injections of cyclophosphamide at 75 mg/kg body weight. infection with massachusetts 41 infectious bronchitis virus was timed to coordinate heterop ... | 1997 | 9356694 |
| effect of dietary fatty acids on humoral immune response of turkeys. | 1. this study examined the effect of increasing amounts of dietary polyunsaturated fatty acids on the fatty acid composition in serum and antibody production following a standard vaccination programme in growing turkeys. turkey poults were fed on 5 diets containing 75g/kg added fat made up of different proportions of palm and soyabean oils, and were vaccinated against newcastle disease, infectious bronchitis and necrotic enteritis according to a standard vaccination programme. blood samples were ... | 1997 | 9347140 |
| dietary fish oil alters specific and inflammatory immune responses in chicks. | two experiments were designed to determine the effects of dietary (n-3) fatty acids and grain source on the growth-suppressive effects of the inflammatory response and indices of specific immunity. in experiment 1, chicks were fed diets containing 0.5, 1, or 2 g/100 g of either corn oil or fish oil. in experiment 2, chicks were fed diets containing up to 2 g/100 g of either fish oil, linseed oil or corn oil as the source of dietary fat, in either cereal grain- or corn-based diets. in each experi ... | 1997 | 9311962 |
| the carboxyl-terminal 120-residue polypeptide of infectious bronchitis virus nucleocapsid induces cytotoxic t lymphocytes and protects chickens from acute infection. | specific cytotoxic t-lymphocyte (ctl) responses to nucleocapsid of infectious bronchitis virus (ibv) were identified by using target cells infected with a semliki forest virus (sfv) vector. effector cells for ctl assays were collected from chickens infected with the gray strain of ibv or inoculated with a dna plasmid encoding nucleocapsid proteins. ibv-specific ctl epitopes were mapped within the carboxyl-terminal 120 amino acids of the nucleocapsid protein. ctl lysis of target cells infected wi ... | 1997 | 9311878 |
| towards the routine application of nucleic acid technology for avian disease diagnosis. | the use of nucleic acid technology (polymerase chain reaction, probing, restriction fragment analysis and nucleotide sequencing) in the study of avian diseases has largely been confined to fundamental analysis and retrospective studies. more recently these approaches have been applied to diagnosis and what one might call real-time epidemiological studies on chickens and turkeys. at the heart of these approaches is the identification and characterisation of pathogens based on their genetic materi ... | 1997 | 9276989 |
| expression of a coronavirus ribosomal frameshift signal in escherichia coli: influence of trna anticodon modification on frameshifting. | eukaryotic ribosomal frameshift signals generally contain two elements, a heptanucleotide slippery sequence (xxxyyyn) and an rna secondary structure, often an rna pseudoknot, located downstream. frameshifting takes place at the slippery sequence by simultaneous slippage of two ribosome-bound trnas. all of the trnas that are predicted to decode frameshift sites in the ribosomal a-site (xxxyyyn) possess a hypermodified base in the anticodon-loop and it is conceivable that these modifications play ... | 1997 | 9237903 |
| experimental confirmation of recombination upstream of the s1 hypervariable region of infectious bronchitis virus. | chimeric infectious bronchitis virus (ibv) genomes with cross-over sites in the s1 gene were generated by co-infection with two distinct ibv strains. recombinant viruses were collected from chicken embryos, embryonic cultured cells and chickens co-infected with ark99 and mass41 strains and purified by differential centrifugation. the recombinant s1 genes were identified by reverse transcription polymerase chain reaction (rtpcr) using heterologous primers and confirmed by nucleotide sequencing. t ... | 1997 | 9213388 |
| a novel protein polymorphism differentiates the california serotype of infectious bronchitis from other serotypes common to california. | the california (cal) serotype of infectious bronchitis virus (ibv) was isolated from layer flocks in southern california in the early 1980s. since then, it has spread to the broiler-producing regions of central california, where it has been implicated in respiratory disease outbreaks in vaccinated flocks. lack of a procedure for quickly identifying ibv serotypes in commercial chicken flocks has prevented the causal association of the ibv cal serotype with respiratory disease outbreaks. a protein ... | 1997 | 9211233 |
| effects of newcastle disease vaccines and newcastle disease/infectious bronchitis combination vaccines on the head-associated lymphoid tissues of the chicken. | ten newcastle disease virus (ndv) and 10 ndv and infectious bronchitis virus (ibv) combination vaccines (ndv/ibv) were evaluated for their effect on the head-associated lymphoid tissue (halt) of 2-wk-old chicks. after vaccination, the chicks were subjected to an in vivo assay that measures the ability of the gland of harder (gh) to respond to killed brucella abortus antigen given in the eye by titering b. abortus antibodies in the tears. following this, several sites in the halt and trachea were ... | 1997 | 9201406 |
| infectious bronchitis: effect of viral doses and routes on specific lacrimal and serum antibody responses in chickens. | an enzyme-linked immunosorbent assay was used to measure the effect of various infectious bronchitis virus (ibv) (strain h-120) vaccine doses and routes of immunization on specific lacrimal and serum antibody responses. the results of the first trial showed that the maximum dose, 10(6) median embryo infective doses (eid50s), delivered by the ocular route elicited both a systemic and a local antibody response in the vaccinated chickens. lower doses of vaccinal virus, 10(4) (median dose) and 10(2) ... | 1997 | 9201403 |
| isolation and identification of infectious bronchitis virus from chickens in sichuan, china. | a nonhemagglutinating virus was isolated from kidneys and lungs of chickens suspected of having infectious bronchitis infection. specific-pathogen-free embryonated chicken eggs were used as the cultural system. with the use of the ciliary activity of chicken embryo tracheal organ cultures as indicator system, the physicochemical properties of one of the isolated strains (saib3) were shown to be similar to infectious bronchitis virus (ibv) strain m41 (standard strain); whereas electron microscopy ... | 1997 | 9201388 |
| specific cytotoxic t lymphocytes are involved in in vivo clearance of infectious bronchitis virus. | cytotoxic t-lymphocyte (ctl) responses to infectious bronchitis virus (ibv) were determined at regular intervals between 3 and 30 days postinfection (p.i.). the maximum response with 82% lysis of labeled target cells was detected at 10 days p.i. the specific ctl response did not begin to decline until the amount of virus, which peaked at day 8 p.i. in both the kidneys and lungs, started to decrease. clinical respiratory signs of illness also correlated with amount of virus. ctl activity was show ... | 1997 | 9188584 |
| sequence analysis of gene 3, gene 4 and gene 5 of avian infectious bronchitis virus strain cu-t2. | we have previously reported the nucleotide sequences of gene 2 (spike (s) protein gene), gene 6 (nucleocapsid (n) protein gene), and the 3' end untranslated region of a novel avian infectious bronchitis virus (ibv) strain, cu-t2 [jia et al. (1995) arch. virol. 140, 259 271]. in the present report we describe the sequences of the remaining genes of this strain (gene 3, 4 and 5) with the exception of gene 1 (rna polymerase gene). gene 3 contained three open reading frames (orfs), 3a, 3b and 3c of ... | 1997 | 9168126 |
| isolation and identification of ornithobacterium rhinotracheale from commercial broiler flocks on the delmarva peninsula. | the growth and biological characteristics of isolates of ornithobacterium rhinotracheale (ort) from commercial broiler chickens in the mid-atlantic region of the u.s.a. appear to be identical to those previously reported in the literature. the clinical disease and lesions are also similar to those reported from other poultry growing regions including south africa and europe. the diagnostic cases included in this report were often associated with known respiratory pathogens, namely, lentogenic ne ... | 1997 | 9087345 |
| experimental production of ascites in broiler chickens using infectious bronchitis virus and escherichia coli. | common commercial strain male broilers were intratracheally inoculated with 0.3 ml of fluid containing 10(3.7) embryo infective doses of infectious bronchitis virus (ibv) at 14 days of age and 7.5 x 10(6) colony-forming units of escherichia coli at 18 days of age. ascites was detected in 15 out of 100 infected birds, which was significantly higher than in a control group of 100 mock-infected birds (p < 0.01). some parabronchi were blocked by copious exudate containing heterophils and fibrin in t ... | 1997 | 9087339 |
| further development and use of a molecular serotype identification test for infectious bronchitis virus. | previously, we developed a rapid serotype identification test for infectious bronchitis virus (ibv) that utilizes the reverse transcriptase-polymerase chain reaction (rt-pcr) and restriction fragment length polymorphism analysis. the rt-pcr is used to amplify the s1 gene from rna extracted from the virus grown in eggs. restriction enzyme digestion and electrophoresis of that pcr product is used to determine the serotype of the virus. the purpose of this study was threefold. first, using a modifi ... | 1997 | 9087326 |
| attempts to reproduce a runting/stunting-type syndrome using infectious agents isolated from affected mississippi broilers. | various organisms, including 12 aerobic and 2 anaerobic bacteria, an infectious bronchitis virus (ibv), a reovirus, and 2 bacteriophages, were isolated from intestinal tracts of commercial broiler chicks undergoing a runting/stunting-type condition. in a series of trials, these agents were given alone and in combination to 1-day-old chicks in an attempt to reproduce the field condition. because the agents were isolated and evaluated over time, an augmented designs variation of the analysis of va ... | 1997 | 9087323 |
| rapid diagnosis of avian infectious bronchitis virus by the polymerase chain reaction. | a simple, sensitive and specific polymerase chain reaction (pcr) procedure was developed in order to detect infectious bronchitis virus (ibv) directly in tissue samples. viral rna was extracted from allantoic fluids and cell cultures infected experimentally with different strains of ibv and from tissues of naturally infected birds. viral rna was then amplified and identified by a nested rt-pcr assay using two sets of primers flanking a well-conserved region of the nucleocapsid gene. the selected ... | 1997 | 9079758 |
| growth of infectious bronchitis virus vaccines in oviducts derived from oestrogen-treated chicks and embryos. | six commercial infectious bronchitis virus (ibv) vaccines and five ibv field strains were titrated in tracheal organ cultures (toc) and oviduct organ cultures (ooc). endpoints were determined in three different ways: ciliostasis (cd50), immunofluorescence staining (ifid50) and organ culture infectivity (ocid50). for the two most attenuated vaccine viruses, infectivity assessed by ifid50 and ocid50 was significantly higher than that assessed by cd50. no significant differences were found between ... | 1997 | 9066033 |
| derivatives of activated h-ras lacking c-terminal lipid modifications retain transforming ability if targeted to the correct subcellular location. | to examine the ability of ras to activate signal transduction pathways in the absence of lipid modifications, fusion proteins were constructed that target raswt or activated ras61l to cellular membranes as integral membrane proteins, using the first transmembrane domain of the e1 protein of avian infectious bronchitis virus (ibv), which contains a cis-golgi targeting signal. golgi-targeted derivatives of activated ras were completely inactive in transformation assays. however, when examined in f ... | 1997 | 9050994 |
| proteolytic processing of the coronavirus infectious bronchitis virus 1a polyprotein: identification of a 10-kilodalton polypeptide and determination of its cleavage sites. | proteolytic processing of the polyprotein encoded by mrna 1 is an essential step in coronavirus rna replication and gene expression. we have previously reported that an open reading frame (orf) 1a-specific proteinase of the picornavirus 3c proteinase group is involved in processing of the coronavirus infectious bronchitis virus (ibv) 1a/1b polyprotein, leading to the formation of a mature viral protein of 100 kda. we report here the identification of a novel 10-kda polypeptide and the involvemen ... | 1997 | 9032311 |
| outbreak of infectious bursal disease associated with acute septicaemic colibacillosis in adult prelayer hens. | an outbreak of infectious bursal disease (ibd) occurred concurrently with acute septicaemic colibacillosis in 15 week old prelayer hens. the septicaemia was preceded by a subclinical ibd. mortality in the outbreak began with lesions of septicaemia and escherichia coli was isolated from the heart blood of the birds. after antibiotic treatment of the bacteraemia, mortality continued, spiked, declined and then ceased. ibd was confirmed by bursal lesions characterized by severe lymphocytolysis and c ... | 1996 | 9008959 |
| protectotypic differentiation of avian infectious bronchitis viruses using an in vitro challenge model. | two vaccine and three virulent strains of infectious bronchitis virus (ibv) were used to infect day-old specific-pathogen-free chickens. precocious development of oviducts was induced in young female chicks by oestrogen injections. tracheal and oviduct organ cultures prepared from immunised chickens were challenged in vitro with homologous and heterologous viruses to assess tracheal and oviduct cross-protection. tracheal cross-protection was seen between serologically related and unrelated virus ... | 1996 | 9008335 |
| experimental infection in turkeys and chickens with ornithobacterium rhinotracheale. | ornithobacterium rhinotracheale was found to cause growth retardation in both turkeys and chickens after experimental intra-air sac administration and to cause growth retardation together with airsacculitis and pneumonia after aerosol administration. both turkey and chicken isolates of o. rhinotracheale were able to induce the same kind of respiratory inflammations and weight-gain losses in chickens as well as turkeys. turkey rhinotracheitis virus was found to have a triggering effect on the o. ... | 1996 | 8980818 |
| replication and packaging of coronavirus infectious bronchitis virus defective rnas lacking a long open reading frame. | the construction of a full-length clone of the avian coronavirus infectious bronchitis virus (ibv) defective rna (d-rna), cd-91 (9,080 nucleotides [z. penzes et al., virology 203:286-293]), downstream of the bacteriophage t7 promoter is described. electroporation of in vitro t7-transcribed cd-91 rna into ibv helper virus-infected primary chick kidney cells resulted in the production of cd-91 rna as a replicating d-rna in subsequent passages. three cd-91 deletion mutants were constructed--cd-44, ... | 1996 | 8970992 |
| isolation of 'variant' strains of infectious bronchitis virus from vaccinated chickens in great britain. | 1996 | 8961529 | |
| involvement of gicerin, a cell adhesion molecule, in tracheal development and regeneration. | gicerin is a novel cell adhesion protein that belongs to the immunoglobulin superfamily. gicerin protein adheres to neurite outgrowth factor, an extracellular matrix protein in the laminin family, and also exhibits homophilic adhesion. in the present study, we investigated the involvement of gicerin and neurite outgrowth factor in tracheal development and regeneration. in an early embryonic stage, gicerin protein was highly expressed in tracheal epithelial cells, but not in loosely arranged mese ... | 1996 | 8959345 |
| novel variation in the n protein of avian infectious bronchitis virus. | the nucleocapsid protein of coronaviruses has been considered highly conserved, showing greater than 94% conservation within strains of a given species. we determined the nucleotide sequence of the n gene and the 3' untranslated region (utr) of eight naturally occurring strains of ibv which differed in pathogenicity and tissue tropism. in pairwise comparisons, the deduced amino acid sequences of n of five strains vic s, n1/62, n9/74, n2/75, and v5/90 (group i) shared 92.3-98.8% identity. the thr ... | 1996 | 8955062 |
| local antibody production in the oviduct and gut of hens infected with a variant strain of infectious bronchitis virus. | following infection of 16-week old specific pathogen-free (spf) female chickens with an enterotropic variant of infectious bronchitis virus (ibv) strain g, ibv-specific immunoglobulin g (igg) and iga were detected in tears, tracheal washes, oviduct washes, duodenal and caecal contents using class-specific monoclonal antibodies in enzyme linked immunosorbent assays (elisa). igg antibody content was highest in tears on day 7 post-infection (p.i.) and was still detectable on day 23 p.i. significant ... | 1996 | 8941976 |
| local and systemic specific antibody response of different chicken lines after ocular vaccination against infectious bronchitis. | the specific lacrimal fluid iga levels and the specific serum igg levels of broiler chicks (meat type hybrids (mt)), brown-egg layer chicks (heavy layer (hl)), and white leghorn chicks (light layer (ll)) were compared after infectious bronchitis virus (ibv) ocular vaccination at 1 day of age. all birds were maintained as a mixed population throughout the experiment of 45 days. the class specific antibody levels were determined at regular intervals by enzyme-linked immunosorbent assays. all birds ... | 1996 | 8921732 |
| genetic grouping for the isolates of avian infectious bronchitis virus in taiwan. | in order to differentiate recent isolates of avian infectious bronchitis virus (ibv) in taiwan, polymerase chain reaction (pcr), restriction fragment length polymorphism (rflp), and direct sequencing methods were used to type 25 ibv taiwan isolates. two conserved sequences that flank the hypervariable region i (hvr i) in the n-terminus of s1 protein gene were chosen as primers. sequences of 228-231 base pairs (bp) were amplified by pcr from 25 taiwan isolates and 4 reference strains (h120, conn, ... | 1996 | 8893790 |
| divergent antibody responses to vaccines and divergent body weights of chicken lines selected for high and low humoral responsiveness to sheep red blood cells. | primary and secondary antibody responses to intramuscularly administered proteins of eschericia coli (f11), newcastle disease virus (ncd), infectious bronchitis virus (ib), and infectious bursal disease virus (ibd), respectively, were measured at weekly intervals in two chicken lines. the latter had been divergently selected for high and low antibody responses to sheep red blood cells (srbc), and in a random-bred control line. an oil-based adjuvant was required to induce primary and secondary an ... | 1996 | 8883795 |
| isolation, pathogenicity, and h120 protection efficacy of infectious bronchitis viruses isolated in taiwan. | seven isolates of infectious bronchitis (ib) virus (ibv) were isolated from two breeder farms and five broiler farms in taiwan in 1992. the cardinal signs of disease in breeders were egg production drops and watery albumen, and those in broilers were respiratory distress and renal urate deposition or death. all diseased chickens had been vaccinated with ib vaccines (mostly h120). the viruses were isolated and identified by chicken embryo inoculation and electron microscopy. the genomes of the is ... | 1996 | 8883793 |
| attenuation of lentogenic newcastle disease virus strain b-1 by cold adaptation. | the hitchner b-1 strain of newcastle disease virus was plaque-cloned and then serially passaged 36 times in specific-pathogen-free (spf) chicken embryos incubated at two different temperatures. virus passaged at a reduced temperature (29 c) was identified as cold-adapted (ca) and virus passaged at the normal temperature (37 c) was designated non-cold-adapted (non-ca). the ca and non-ca b-1 viruses were compared with the parent b-1 and a commercial b-1 vaccine. in vitro ca b-1 characteristics inc ... | 1996 | 8883791 |
| serological survey for avian viruses in houbara bustards (chlamydotis undulata macqueenii). | 1996 | 8883351 | |
| a region of the coronavirus infectious bronchitis virus 1a polyprotein encoding the 3c-like protease domain is subject to rapid turnover when expressed in rabbit reticulocyte lysate. | in order to investigate the mechanisms involved in the processing of infectious bronchitis virus polyproteins, several candidate regions of the genome have been cloned and expressed in vitro. during these studies it was observed that the translation product encoded by one of these clones (pkt205) was poorly expressed. biochemical and genetic analyses revealed that the basis for the poor expression was a post-translational event involving ubiquitination of the protein and degradation by an atp-de ... | 1995 | 8847511 |
| generation of a defective rna of avian coronavirus infectious bronchitis virus (ibv). defective rna of coronavirus ibv. | the beaudette strain of ibv was passaged 16 times in chick kidney (ck) cells. total cellular rna was analyzed by northern hybridization and was probed with 32p-labeled cdna probes corresponding to the first 2 kb of the 5' end of the genome, but excluding the leader, and to the last 1.8 kb of the 3' end of the genome. a new, defective ibv rna species (cd-91) was detected at passage six. the defective rna, present in total cell extract rna and in oligo-(dt)30-selected rna from passage 15, was ampl ... | 1995 | 8830542 |
| first experimental evidence of recombination in infectious bronchitis virus. recombination in ibv. | a high frequency of recombination has been shown to occur during replication of the coronavirus mouse hepatitis virus (mhv) in vitro as well as in vivo. although sequencing of field strains of coronavirus infectious bronchitis virus (ibv) has indicated that ibv strains also undergo recombination, there has been no experimental evidence to support this deduction. to investigate whether recombination occurs in ibv, embryonated eggs were coinfected with ibv-beaudette and ibv-m41. potential recombin ... | 1995 | 8830540 |
| interactions between the ibv nucleocapsid protein and rna sequences specific for the 3' end of the genome. | the infectious bronchitis virus (ibv) nucleocapsid protein was expressed as a fusion protein in bacteria. the coding sequence differed from the native protein only in the addition of six histidine residues at the amino terminus which were used for enrichment with a nickel affinity column. in gel shift assays, the mobility of labelled g rna was decreased with increasing concentrations of the fusion protein. competitive gel shift assays with labelled g rna indicated that the protein interacted wit ... | 1995 | 8830535 |
| involvement of viral and cellular factors in processing of polyprotein encoded by orf1a of the coronavirus ibv. | 1995 | 8830517 | |
| identification of a trypsin-like serine proteinase domain encoded by orf 1a of the coronavirus ibv. | 1995 | 8830516 | |
| production and immunogenicity of multiple antigenic peptide (map) constructs derived from the s1 glycoprotein of infectious bronchitis virus (ibv). | synthetic peptides were prepared as multiple antigenic peptide (map) constructs to the s1 glycoprotein of infectious bronchitis virus (ibv). the map system has been used in the production of anti-peptide and anti-protein antibodies. it has an advantage over linking peptides to a highly immunogenic carrier molecule because antibodies are not produced to the map core matrix of lysine residues. two 25-residue peptides were synthesized to the arkansas serotype and two were synthesized to the massach ... | 1995 | 8830482 |
| analysis of the serotype-specific epitopes of avian infectious bronchitis virus strains ark99 and mass41. | the ark and mass serotype-specific epitopes of infectious bronchitis virus were studied by immunofluorescence and immunoprecipitation of mutant and recombinant spike glycoproteins (s protein) expressed in mouse l cells. serotype-specific monoclonal antibodies could bind to the recombinant proteins of ark99 and mass41 expressed from the chimeras in which the n-terminal thirds of the s1 sequences were reciprocally exchanged. therefore, it appears that the respective serotype-specific epitopes of b ... | 1996 | 8794378 |
| concomitant ornithobacterium rhinotracheale and newcastle disease infection in broilers in south africa. | ornithobacterium rhinotracheale was first isolated from broilers in south africa in 1991. the importance of o. rhinotracheale infections has been established, with growth suppression, respiratory symptoms, and arthritis commonly seen as complications. dual infection with newcastle disease and o. rhinotracheale in 28-day-old broilers led to more severe respiratory lesions and higher mortality rates than in birds with only newcastle disease. it was concluded that the pathogenicity of newcastle dis ... | 1996 | 8790906 |
| antimicrobial activity of chicken and turkey heterophil peptides chp1, chp2, thp1, and thp3. | four avian heterophil antimicrobial cationic peptides (chicken heterophil peptides 1 and 2, and turkey heterophil peptides 1 and 3) were evaluated for in vitro microbicidal activity against selected avian pathogens and human pathogens which are harbored by birds. at concentrations of 16-2 micrograms/ml, all four avian peptides effected a greater than 90% reduction in the survival of candida albicans, salmonella enteriditis, and campylobacter jejuni. none of the peptides, including the known anti ... | 1995 | 8748545 |
| comparison of the effects of infectious bronchitis and infectious laryngotracheitis on the chicken respiratory tract. | in infectious bronchitis (ib) virus infection of the chicken the upper and lower respiratory tracts were damaged, but infectious laryngotracheitis (ilt) virus caused lesions only in the upper respiratory tract. secondary infection with escherichia coli was apparent in the trachea of birds inoculated with either virus but was more striking in those given ib virus. serum alpha 1-acid glycoprotein, an acute-phase protein, occurred in higher concentrations in chickens inoculated with ib virus than i ... | 1996 | 8729076 |
| detection of contamination of vaccines with the reticuloendotheliosis virus by reverse transcriptase polymerase chain reaction (rt-pcr). | the reverse transcriptase polymerase chain reaction (rt-pcr) was applied to detect contamination of marek's disease (md) vaccine with reticuloendotheliosis virus (rev). the env primers were used for the 1st rt-pcr to amplify the dna fragments of rev-a and -t. the rel and env primers were used for nested-pcr to confirm the sites deleted from rev-t and rev-a. specific amplification products were detected in the 1st rt-pcr with these primers. by nested pcr with the env and the rel primer pairs, the ... | 1996 | 8725107 |
| embryo vaccination of chickens with infectious bronchitis virus: histologic and ultrastructural lesion response and immunologic response to vaccination. | chicken embryos 18 days of age and newly hatched chicks were vaccinated with an infectious bronchitis virus (ibv) vaccine (v-ibv) or with an ibv vaccine that had been serially passaged 40 times in chick kidney tissue culture (p-ibv). immunologic and pathologic changes in the chicks were compared at selected intervals until the 35th day. pathologic changes were evaluated by light, transmission, and scanning electron microscopy. immunologic changes were assayed by a constant virus-diluting serum p ... | 1995 | 8719209 |
| experimental reproduction of severe hypoglycemia and spiking mortality syndrome using field-derived and embryo-passaged preparations. | the clinical signs, enteritis, weight depression, and hypoglycemia of spiking mortality syndrome were experimentally reproduced in broiler breeders and broiler chicks. inocula included 1) virus-like particles from intestines of chicks with spiking mortality syndrome that had been banded in a discontinuous renograffin gradient, 2) homogenized darkling beetles collected from litter of farms where spiking mortality syndrome had occurred repeatedly, and 3) homogenized embryos which had been inoculat ... | 1996 | 8713030 |
| avian infectious bronchitis: viral persistence in the harderian gland and histological changes after eyedrop vaccination. | the histological changes in the harderian gland (hg) induced by the attenuated h-120 infectious bronchitis virus (ibv) vaccine strain and the persistence of this virus in the stroma of the gland was evaluated in chickens after eyedrop vaccination. virus replication induced an increase in ibv-specific enzyme-linked immunosorbent assay antibody levels from marginal levels at vaccination (26 days of age) to significantly higher levels 10 days after exposure. ibv antigen was detected in the hg by bo ... | 1996 | 8713024 |
| z-membranes: artificial organelles for overexpressing recombinant integral membrane proteins. | we have expressed a fusion protein formed between the avian infectious bronchitis virus m protein and the bacterial enzyme beta-glucuronidase in transgenic tobacco cells. electron microscope images of such cells demonstrate that overexpression of this fusion protein gives rise to a type of endoplasmic reticulum membrane domain in which adjacent membranes become zippered together apparently as a consequence of the oligomerizing action of beta-glucuronidase. these zippered (z-) membranes lack mark ... | 1996 | 8700911 |
| isolation and identification of infectious bronchitis virus from pheasants. | 1996 | 8686155 | |
| a survey of the presence of a new infectious bronchitis virus designated 4/91 (793b). | on the basis of virus isolation and the demonstration of specific neutralising antibody in sera, infectious bronchitis virus (ibv) 4/91 (commonly called 793b) has been shown to be present in broiler, breeder and layer flocks of chickens in many parts of western europe and also in thailand and mexico. these flocks had all been vaccinated against infectious bronchitis and the need for improved methods to control this new virus, still prevalent at least four years after it was first isolated, is di ... | 1996 | 8677618 |
| characterization in vitro of an autocatalytic processing activity associated with the predicted 3c-like proteinase domain of the coronavirus avian infectious bronchitis virus. | a region of the infectious bronchitis virus (ibv) genome between nucleotide positions 8693 and 10927 which encodes the predicted 3c-like proteinase (3clp) domain and several potential cleavage sites has been clones into a t7 transcription vector. in vitro translation of synthetic transcripts generated from this plasmid was not accompanied by detectable processing activity of the nascent polypeptide unless the translation was carried out in the presence of microsomal membrane preparations. the pr ... | 1996 | 8627718 |
| sequence analysis of the s1 glycoprotein of infectious bronchitis viruses: identification of a novel genotypic group in australia. | sequencing of the s1 genes of nine australian strains of infectious bronchitis virus (ibv) identified two genotypically distinct groups of strains. the strains vic s, v5/90, n1/62, n3/62, n9/74, and n2/75 comprised group i, sharing 80.7-98.3% identity in their deduced amino acid sequences. all group i strains were able to replicate in the trachea and kidney but only four strains, vic s, n1/62, n9/74, and n2/75, were nephropathogenic, the latter three causing mortalities ranging from 32 to 96%. g ... | 1996 | 8601775 |
| the infectious bronchitis virus nucleocapsid protein binds rna sequences in the 3' terminus of the genome. | the infectious bronchitis virus (ibv) nucleocapsid protein was expressed as a bacterial fusion protein which differed from the native protein only in the addition of six amino terminus histidine residues. using rna overlay protein blot assays, the recombinant protein was shown to bind to rna fragments specific for the positive sense 3' noncoding end of the ibv genome. at greater concentrations of sodium chloride, the native and fusion nucleocapsid proteins similarly bound to g rna, representing ... | 1996 | 8599203 |
| turkey rhinotracheitis virus isolated from broiler chicken with swollen head syndrome in japan. | turkey rhinotracheitis (trt) virus was first isolated from a commercial broiler chicken with swollen head syndrome (shs) in japan. at the same time, newcastle disease virus (ndv), infectious bronchitis virus (ibv), avian reovirus (arv), escherichia coli (e.coli), morganella morganii, and proteus mirabilis were also isolated from the same broiler chicken. the presence of antibodies to trt virus was confirmed in the sera of 34-day-old chickens of the flock with shs, however the antibodies to trt v ... | 1995 | 8593307 |
| a highly conserved epitope on the spike protein of infectious bronchitis virus. | the predicted amino acid sequence and secondary structures of s1 of the spike protein (s) of infectious bronchitis viral (ibv) strains from europe, the u.s.a., and japan were compared. an antigenic determinant that was highly conserved in both the primary amino acid sequence and secondary structure of all strains was identified between amino acid positions 240 to 255. a synthesized peptide corresponding to this region was found to react with all polyclonal antisera examined from various ibv stra ... | 1995 | 8572941 |
| recent isolates of newcastle disease virus in australia. | forty-five recently isolated strains of newcastle disease virus and the v4 vaccine strain of newcastle disease virus were used to infect experimental chickens. neither v4 nor any of the new strains produced detectable clinical disease. all the viruses produced an antibody response and spread by contact. some of the newly isolated viruses produced a more rapid serological response than v4 virus did. dual or multiple infections with one of the new strains of newcastle disease virus, infectious bro ... | 1995 | 8545958 |
| ribosomal pausing during translation of an rna pseudoknot. | the genomic rna of the coronavirus infectious bronchitis virus contains an efficient ribosomal frameshift signal which comprises a heptanucleotide slippery sequence followed by an rna pseudoknot structure. the presence of the pseudoknot is essential for high-efficiency frameshifting, and it has been suggested that its function may be to slow or stall the ribosome in the vicinity of the slippery sequence. to test this possibility, we have studied translational elongation in vitro on mrnas enginee ... | 1993 | 8413285 |
| retention of a cis golgi protein requires polar residues on one face of a predicted alpha-helix in the transmembrane domain. | the first membrane-spanning domain (m1) of the model cis golgi protein m (formerly called e1) from the avian coronavirus infectious bronchitis virus is required for targeting to the golgi complex. when inserted in place of the membrane-spanning domain of a plasma membrane protein (vesicular stomatitis virus g protein), the chimeric protein ("gm1") is retained in the golgi complex of transfected cells. to determine the precise features of the m1 domain responsible for golgi targeting, we produced ... | 1993 | 8400455 |
| presence of subgenomic mrnas in virions of coronavirus ibv. | the presence of subgenomic mrnas in virions of ibv was examined by probing northern blots of rna extracted from virions using as a probe a cdna of the 3'-terminal nucleocapsid protein (n) gene. this detects all five mrnas because of the 3'-coterminal, nested-set arrangement of coronavirus mrnas. the mrnas were readily detected even after extensive purification of virions and after rnase a treatment of virions. in sucrose gradients the peaks of virus particles, genomic rna (grna), and mrnas were ... | 1993 | 8395112 |
| sequence analysis of strains of avian infectious bronchitis coronavirus isolated during the 1960s in the u.k. | sequencing of parts of the spike, small membrane, and integral membrane protein genes of english isolates of avian infectious bronchitis virus (ibv) isolated in the 1960s revealed that they were not the direct ancestors of those isolated in the 1980s. | 1993 | 8390829 |
| oligonucleotide probes in infectious bronchitis virus diagnosis and strain identification. | genomic rna fingerprints of infectious bronchitis virus (ibv) strains m41 and conn46 were prepared to identify t1 rnase-resistant oligonucleotides 'unique' to each of the two ibv strains. such oligonucleotides were subsequently eluted from the gels and their nucleotide sequences determined. when oligonucleotide probes of those sequences were synthesized and used in a dot-blot hybridization assay, the probes lacked ibv strain-specificity and reacted with the rnas of homologous as well as heterolo ... | 1993 | 8390475 |
| chemiluminescent detection of infectious bursal disease virus with a pcr-generated nonradiolabeled probe. | a polymerase chain reaction (pcr)-generated digoxigenin-labeled nonradioactive oligonucleotide probe was developed and utilized in slot-blot hybridization coupled with chemiluminescence for the detection of infectious bursal disease virus (ibdv). the probe was prepared from the rna of the standard challenge strain (stc) of ibdv serotype 1 by reverse transcription followed by 2 pcr amplifications with 2 separate sets of primers. rna of stc viruses prepared from bursae infected with stc viruses wa ... | 1993 | 8389597 |
| analysis of a hypervariable region in the 3' non-coding end of the infectious bronchitis virus genome. | previous studies on infectious bronchitis virus (ibv) cdna have identified a region of about 184 bases in the 3' non-coding terminus of both the u.s. prototype strain (beaudette) and a japanese strain (kb8523), that was not present in an antigenically closely related u.s. strain, massachusetts (mass) 41 (boursnell et al., 1985; sutou et al., 1988). in order to investigate the origin and function of this region and its occurrence in nature, the cdna sequences of the 3' non-coding regions of three ... | 1993 | 8388141 |
| a monoclonal antibody blocking elisa to detect serotype-specific infectious bronchitis virus antibodies. | a monoclonal antibody (mab) blocking enzyme-linked immunosorbent assay (b-elisa) was developed and compared to a conventional indirect elisa (i-elisa) and a virus-neutralization (vn) test for detection of specific antibodies to avian infectious bronchitis virus (ibv) serotypes. sera used in this study were derived from chickens experimentally inoculated with the three most prevalent ibv serotypes, arkansas (ark), connecticut (conn), and massachusetts (mass). overall, there was good correlation b ... | 1993 | 8384739 |
| polymerase chain reaction and a biotin-labeled dna probe for detection of infectious bronchitis virus in chickens. | polymerase chain reaction (pcr) and a biotin-labeled dna probe were used to amplify and detect the genome of infectious bronchitis virus (ibv) from tracheal swabs taken from chickens that were experimentally inoculated with the ibv beaudette, arkansas, and gray strains. the viral genome was successfully detected by pcr and confirmed by dot-hybridization assay using a biotin-labeled dna probe on days 1, 3, 9, and 14 after exposure. direct electron microscopy (em) analysis was used to compare the ... | 1993 | 8383958 |
| evidence of natural recombination within the s1 gene of infectious bronchitis virus. | during an outbreak of severe respiratory disease, a field strain of infectious bronchitis virus (ibv), pp14, was isolated from a bird in a texas flock that had been previously vaccinated with an attenuated mass serotype virus. after cloning and sequencing the s1 gene from several ibv strains, it was found that the 5' end of the cdna was 96% identical to the published sequences of mass41 and 77% identical with ark99. the following 402 bases which included the hypervariable regions (hvr) of the s1 ... | 1993 | 8380672 |
| nucleotide sequence of the human coronavirus 229e rna polymerase locus. | the nucleotide sequence of the human coronavirus 229e (hcv 229e) rna polymerase gene and the 5' region of the genome has been determined. the polymerase gene is comprised of two large open reading frames, orf1a and orf1b, that contain 4086 and 2687 codons, respectively. orf1b overlaps orf1a by 43 bases in the (-1) reading frame. the in vitro translation of sp6 transcripts which include hcv 229e sequences encompassing the orf1a/orf1b junction show that expression of orf1b can be mediated by ribos ... | 1993 | 8337838 |
| dot-blot hybridization using digoxigenin-labeled cdna probe complementary to the s1 gene of avian infectious bronchitis virus permits discrimination between virus strains. | digoxigenin-dutp-labeled dna probe was prepared from a cdna clone complementary to the gene encoding s1 region of the spike protein of infectious bronchitis coronavirus (ibv) strain m41. the probe exclusively reacted with four strains at 56 degrees c which were grouped to the same serotype as the strain used for the probe. in contrast, at 68 degrees c, the probe reacted only with the homologous strain and did not react even with the strains belonging to the same serotype. the dot-blot hybridizat ... | 1993 | 8286524 |
| distinct structural elements and internal entry of ribosomes in mrna3 encoded by infectious bronchitis virus. | infectious bronchitis virus (ibv) mrna3 encodes three small proteins, 3a, 3b, and 3c, at its 5' end. recently, it was demonstrated that initiation of protein 3c is dependent on the upstream sequence. monte carlo simulations of rna folding in this tricistronic mrna3 indicate that a highly significant folding region occurs prior to the initiator aug of 3c. the unusual folding region (ufr) of 265 nucleotides (nt) contains the coding sequences of proteins 3a and 3b. details of the structural analyse ... | 1994 | 8259681 |
| antibody detection in matched chicken sera and egg-yolk samples by commercial enzyme-linked immunosorbent assay kits for newcastle disease virus, infectious bronchitis virus, infectious bursal disease virus, and avian reovirus. | elisa kits have been used to detect antibody in egg yolk. the major advantage eggs offer over blood samples is the ability to collect samples without compromising flock biosecurity. a disadvantage to using egg yolk over sera concerns the method of preparing yolk for antibody testing. the technique used in this study involved a simple dilution method with no mixing or extraction. to determine the adequacy of yolk samples to replace serum samples, a serum sample and the first six eggs were obtaine ... | 1993 | 8257378 |
| [serologic monitoring of pullet and laying hen flocks in switzerland: results from the years 1990 and 1991]. | in 1990 and 1991 4522 blood samples from 398 pullet flocks and 1338 blood samples from 128 laying flocks were monitored for antibody against infectious bronchitis virus, infectious laryngotracheitis virus, adenovirus, reovirus, infectious bursal disease virus, newcastle disease virus, mycoplasma gallisepticum and mycoplasma synoviae. the results are discussed for pullets and laying hens. | 1993 | 8211056 |
| characterization of the human coronavirus 229e (hcv 229e) gene 1. | the sequence of the hcv 229e gene 1 has been determined and compared with the homologous sequences of the murine hepatitis virus and the avian infectious bronchitis virus. the coding sequence of gene 1 is 20,273 nucleotides in length. within this coding region are two large open reading frames, orf 1a (4,086 codons) and orf 1b (2,687 codons) which overlap by 40 nucleotides. in the overlapping region, the genomic rna can be folded into a pseudoknot structure, an element which is known to mediate ... | 1993 | 8209774 |
| structural proteins of avian infectious bronchitis virus: role in immunity and protection. | the antigenicity of the s1, m and n proteins of avian infectious bronchitis virus was compared following immunization of chickens with live and inactivated virus. the n protein was immunodominant antigen inducing cross-reactive antibodies in high titres whereas the s1 glycoprotein induced serotype-specific and cross-reactive antibodies. the m glycoprotein elicited antibodies in low titres and of limited cross-reactivity. immunization of chickens with the purified n and m proteins did not induce ... | 1993 | 8209767 |
| characterization of ibv variant strain pl 84084 isolated in france. | 1993 | 8209760 |