Publications
| Title | Abstract | Year Filter | PMID(sorted ascending) Filter |
|---|
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| isolation of 'variant' strains of infectious bronchitis virus from vaccinated chickens in great britain. | 1996 | 8961529 | |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| the early history of infectious bronchitis. | 1998 | 9876830 | |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| serological evidence for a 793/b related avian infectious bronchitis virus in india. | 1999 | 10204229 | |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 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 |
| 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 |
| 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 |
| csiro's 'natural' vaccines. | 1999 | 10561787 | |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| avian infectious bronchitis virus: isolation of an apparently new variant in italy. | 2000 | 10718592 | |
| 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 |