Publications
| Title | Abstract | Year(sorted descending) Filter | PMID Filter |
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| relationship between serotypes and genotypes based on the hypervariable region of the s1 gene of infectious bronchitis virus. | to group infectious bronchitis virus (ibv) isolates, a genetic grouping method based on hypervariable region 1 (hvr 1, nucleotides 168 to 197) was compared with that based on the whole s1 gene. both methods resulted in the same grouping data. so the grouping method based on hvr 1 could represent the grouping method based on the whole s1 gene. taiwan isolates could not be placed within the existing groups. in order to test the correlation between genotype and serotype, a one-way neutralization te ... | 2000 | 10752554 |
| infectious bronchitis virus e protein is targeted to the golgi complex and directs release of virus-like particles. | the coronavirus e protein is a poorly characterized small envelope protein present in low levels in virions. we are interested in the role of e in the intracellular targeting of infectious bronchitis virus (ibv) membrane proteins. we generated a cdna clone of ibv e and antibodies to the e protein to study its cell biological properties in the absence of virus infection. we show that ibv e is an integral membrane protein when expressed in cells from cdna. epitope-specific antibodies revealed that ... | 2000 | 10756047 |
| structure, stability and function of rna pseudoknots involved in stimulating ribosomal frameshifting. | programmed -1 ribosomal frameshifting has become the subject of increasing interest over the last several years, due in part to the ubiquitous nature of this translational recoding mechanism in pathogenic animal and plant viruses. all cis-acting frameshift signals encoded in mrnas are minimally composed of two functional elements: a heptanucleotide "slippery sequence" conforming to the general form x xxy yyz, followed by an rna structural element, usually an h-type rna pseudoknot, positioned an ... | 2000 | 10764589 |
| the amino and carboxyl domains of the infectious bronchitis virus nucleocapsid protein interact with 3' genomic rna. | previous studies indicated that the nucleocapsid (n) protein of infectious bronchitis virus (ibv) interacted with specific sequences in the 3' non-coding region of ibv rna. in order to identify domains in the n protein that bind to rna, the whole protein (409 amino acids) and six overlapping fragments were expressed as fusion polypeptides with six histidine-tags. using gel shift assays, the intact n protein and amino polypeptides, from residues 1 to 171 and residues 1 to 274, and carboxyl polype ... | 2000 | 10773316 |
| kinetics of lymphocytic subsets in chicken tracheal lesions infected with infectious bronchitis virus. | the kinetics of t-cells (cd3 positive (+), cd4+ and cd8+ cells) and b-cells (igg+, igm+ and iga+ cells) in chicken trachea were studied immunohistochemically and histopathologically following an intratracheal inoculation of infectious bronchitis virus (ibv). viral antigen was detected in the cytoplasm of tracheal epithelium from 16 hr to 6 days post-inoculation (p.i.) with a peak on 4 days p.i. a few igg+, igm+ and iga+ cells were detected in the submucosa from 8 hr p.i. thereafter igg+ and igm+ ... | 2000 | 10823726 |
| expression of reporter genes from the defective rna cd-61 of the coronavirus infectious bronchitis virus. | the defective rna (d-rna) cd-61, derived from the beaudette strain of the avian coronavirus infectious bronchitis virus (ibv), was used as an rna vector for the expression of two reporter genes, luciferase and chloramphenicol acetyltransferase (cat). d-rnas expressing the cat gene were demonstrated to be capable of producing cat protein in a helper-dependent expression system to about 1.6 microgram per 10(6) cells. the reporter genes were expressed from two different sites within the cd-61 seque ... | 2000 | 10859373 |
| localization of linear b-cell epitopes on infectious bronchitis virus nucleocapsid protein. | the nucleocapsid (n) protein of many viruses is highly conserved, immunogenic, and abundantly expressed during infection. these features make it a suitable candidate for diagnostic applications. the nucleocapsid protein of infectious bronchitis virus (ibv) was dissected into 12 fragments and expressed in escherichia coli. sera against australia t, china ch5, singapore p4, usa m41 and china t3 isolates were used to study the conservation and localization of the antigenic region on the ibv nucleoc ... | 2000 | 10865148 |
| further characterization of the coronavirus infectious bronchitis virus 3c-like proteinase and determination of a new cleavage site. | coronavirus infectious bronchitis virus (ibv) encodes a trypsin-like proteinase (3c-like proteinase) by orf 1a, which has been demonstrated to play a pivotal role in proteolytic processing of gene 1-encoded polyproteins. in our previous studies, the proteinase was identified as a 33-kda protein in ibv-infected cells, and its catalytic center was shown to consist of h(2820) and c(2922) residues. it is released from the 1a and 1a/1b polyproteins by autoprocessing at two q-s dipeptide bonds (q(2779 ... | 2000 | 10873746 |
| identification of avian infectious bronchitis virus by direct automated cycle sequencing of the s-1 gene. | direct automated cycle sequencing (dacs) of a reverse transcription-polymerase chain reaction (rt-pcr) product of the s-1 subunit of the spike peplomer gene was used to identify infectious bronchitis virus (ibv) serotypes. degenerate primers ck4 and ck2, utilized previously in our laboratory, were selected for dacs because they successfully amplify a wide range of serotypes represented by various reference strains and field isolates and the resulting polymerase chain reaction (pcr) product conta ... | 2000 | 10879913 |
| increased tracheal colonization in chickens without impairing pathogenic properties of avian pathogenic escherichia coli mt78 with a fimh deletion. | several studies suggest that the expression of f1 fimbriae could be involved in the virulence of escherichia coli for chickens. f1 fimbriae display multivalent properties such as adhesion to epithelia or interaction with the immune system that imply specific interactions between the adhesin fimh and different cell receptors. we constructed a delta fimh mutant of the avian pathogenic e. coli mt78 and evaluated its in vivo colonization and pathogenicity, as compared to that of the parent strain. t ... | 2000 | 10879915 |
| avian infectious bronchitis virus. | infectious bronchitis virus (ibv) is prevalent in all countries with an intensive poultry industry, with the incidence of infection approaching 100% in most locations. vaccination is only partially successful due to the continual emergence of antigenic variants. at many sites, multiple antigenic types are simultaneously present, requiring the application of multiple vaccines. although many countries share some common antigenic types, ibv strains within a geographic region are unique and distinct ... | 2000 | 10935276 |
| detection of antibody to turkey coronavirus by antibody-capture enzyme-linked immunosorbent assay utilizing infectious bronchitis virus antigen. | an antibody-capture enzyme-linked immunosorbent assay (elisa) for detection of antibody to turkey coronavirus (tcv) utilizing infectious bronchitis virus (ibv) antigen was developed. anti-tcv hyperimmune turkey serum and normal turkey serum were used as positive or negative control serum for optimization of the elisa system. goat anti-turkey immunoglobulin g (light plus heavy chains) conjugated with horseradish peroxidase was used as detector antibody. the performance of the elisa system was eva ... | 2000 | 11006996 |
| morphologic observations on respiratory tracts of chickens after hatchery infectious bronchitis vaccination and formaldehyde fumigation. | the histologic changes in the respiratory tracts of chickens were evaluated after hatchery fumigation with 40% formaldehyde vapors and vaccination against infectious bronchitis virus with live attenuated vaccine (massachusetts serotype). one-day-old chickens were housed in four isolation units in controlled environmental conditions, fed and watered ad libitum, and separated into four groups: 1) fumigated and vaccinated birds (fv group); 2) nonfumigated and vaccinated birds (nfv group); 3) fumiga ... | 2000 | 11006997 |
| protective immunity to infectious bronchitis in broilers vaccinated against marek's disease either in ovo or at hatch and against infectious bronchitis at hatch. | two experiments were conducted using commercial broiler chickens to determine if marek's disease (md) vaccines hvt/sb-1 and hvt plus cvi-988 given either in ovo or at hatch adversely affected the efficacy of infectious bronchitis (ib) vaccines (ark and mass serotypes) given by eyedrop on the day of hatch. nonvaccinated negative controls and controls that received only ib vaccines were included in each study. birds were challenged with either infectious bronchitis virus (ibv) mass-41 or ibv ark-9 ... | 2000 | 11007000 |
| emergence of subtype strains of the arkansas serotype of infectious bronchitis virus in delmarva broiler chickens. | infectious bronchitis virus (ibv) field isolates of the arkansas (ark) serotype were identified by reverse transcription-polymerase chain reaction (rt-pcr) as the most common serotype isolated from 1993 to 1997. these isolates were recovered from broiler flocks with respiratory disease raised on the delmarva peninsula in spite of ark vaccination in the region. for the purposes of investigating this apparently paradoxical finding, five rt-pcr ark-positive field isolates recovered in 1995 and 1996 ... | 2000 | 11007004 |
| characterization of infectious bronchitis viruses isolated from outbreaks of disease in commercial flocks in brazil. | fifteen isolations of infectious bronchitis (ib) virus were made from a total of 126 brazilian poultry flocks of all ages that were examined. these flocks (14 chicken and 1 quail) were experiencing a variety of ib-like conditions including respiratory disease, digestive and kidney problems, and drops in egg production. one of the isolates was of the massachusetts serotype. the remainder were examined by means of cross-neutralization tests in tracheal organ cultures and were shown to belong to at ... | 2000 | 11007005 |
| redesign of primer and application of the reverse transcriptase-polymerase chain reaction and restriction fragment length polymorphism test to the de072 strain of infectious bronchitis virus. | diagnosis of the de072 strain of infectious bronchitis virus (ibv) by the reverse transcriptase-polymerase chain reaction (rt-pcr) and restriction fragment length polymorphism (rflp) serotype identification test was not possible because the primer used in the rt-pcr did not amplify the s1 gene of the de072 strain. the 3' end of the polymerase gene and the 5' end of the s2 gene of the de072 strain were sequenced and compared with the forward and reverse rt-pcr primers, respectively. a 2-bp mismat ... | 2000 | 11007014 |
| utilizing fowlpox virus recombinants to generate defective rnas of the coronavirus infectious bronchitis virus. | coronavirus defective rnas (d-rnas) have been used as rna vectors for the expression of heterologous genes and as vehicles for reverse genetics by modifying coronavirus genomes by targetted recombination. d-rnas based on the avian coronavirus infectious bronchitis virus (ibv) d-rna cd-61 have been rescued (replicated and packaged into virions) in a helper virus-dependent manner following electroporation of in vitro-generated t7 transcripts into ibv-infected cells. in order to increase the effici ... | 2000 | 11086116 |
| evidence of genetic diversity generated by recombination among avian coronavirus ibv. | previously, we demonstrated that the de072 strain of ibv is a recombinant which has an ibv strain d1466-like sequence in the s gene. herein, we analyzed the remaining 3.8 kb 3' end of the genome, which includes gene 3, gene 4, gene 5, gene 6, and the 3' non-coding region of the de072 and d1466 strains. those two viruses had high nucleotide similarity in gene 4. however, the other individual genes had a much different level of sequence similarity with the same gene of the other ibv strains. the g ... | 2000 | 11087096 |
| antigen quantification as in vitro alternative for potency testing of inactivated viral poultry vaccines. | routine batch control of licensed inactivated viral vaccines for poultry usually includes a potency assay as a measure of vaccine efficacy. potency assays often consist of vaccination-challenge experiments in the target species or in laboratory animals. instead of measuring the protection of vaccinated animals against virulent pathogens, the serological response after vaccination can be quantified for some vaccines. in vitro antigen quantification assays would be attractive alternatives for the ... | 2000 | 11087135 |
| detection of infectious bronchitis virus. | the detection methods for infectious bronchitis virus (ibv) are reviewed. advantages and disadvantages of available techniques of ibv detection by virus isolation, antigen or genome detection, and serology are discussed. factors of influence on the level of success in detection of ibv after a disease outbreak are discussed, as are the possibilities and dangers of strain classification by protectotyping, serotyping, epitope-typing and genotyping. | 2000 | 19184793 |
| turkey coronavirus is more closely related to avian infectious bronchitis virus than to mammalian coronaviruses: a review. | turkey coronavirus (tcov) is the cause of an acute highly contagious enteric disease of turkeys. in recent years, tcov has been increasingly recognized in north america as an important pathogen of young turkeys, resulting in economic loss due to impaired growth and poor feed conversion. while the epidemiology and pathogenesis of tcov have been extensively studied, tcov remains one of the least characterized of the known coronaviruses. avian and mammalian coronaviruses have been subdivided into d ... | 2000 | 19184806 |
| use of reverse transcriptase-polymerase chain reaction-restriction fragment length polymorphism to examine the interaction between infectious bronchitis virus strains massachusetts 41 and jmk in ovo. | the reverse transcriptase-polymerase chain reaction-restriction fragment length polymorphism (rtpcr-rflp) technique has been developed and used in the serotype diagnosis of infectious bronchitis virus (ibv) infection. in this report, we first demonstrate that the rt-pcr-rflp was sensitive in detecting both massachusetts 41 (mass 41) and jmk strains of ibv singly; the detection limit for both was approximately 0.15ng viral rna using gel electrophoresis. subsequently, the ability of the technique ... | 2000 | 19184836 |
| 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 |
| longitudinal field studies of infectious bronchitis virus and avian pneumovirus in broilers using type-specific polymerase chain reactions. | in longitudinal studies, 13 flocks were swabbed twice each week for the life of the flock (up to 46 days). the swabs were analyzed by type-specific reverse transcriptase polymerase chain reactions. massachusetts type vaccinal infectious bronchitis virus (ibvs), applied at the hatchery, were usually maximal during the first week, as expected and, notably, remained detectable for 3 to 4 weeks, occasionally longer. ibv of the 793/b type (also known as 4/91 and cr88) was detected in 11/13 flocks (85 ... | 1999 | 27266431 |
| co-circulation of four types of infectious bronchitis virus (793/b, 624/i, b1648 and massachusetts). | eighteen isolates of infectious bronchitis virus (ibv) from italy and poland in 1997 to 1998 were comprehensively analysed by serum haemagglutination inhibition and virus neutralization tests, and by type-specific polymerase chain reactions and spike protein s1 gene sequencing. four types of ibv (793/b, 624/i, b1648 and massachusetts) were detected in italy, while the presence of 793/b was confirmed in poland. this showed that not only were four types of ibv co-existing within a single year, but ... | 1999 | 27266430 |
| detection and strain differentiation of infectious bronchitis virus in tracheal tissues from experimentally infected chickens by reverse transcription-polymerase chain reaction. comparison with an immunohistochemical technique. | oligonucleotide pairs were constructed for priming the amplification of fragments of nucleocapsid (n) protein and spike glycoprotein (s) genes of avian infectious bronchitis virus (ibv) by reverse transcriptionpolymerase chain reaction (rt-pcr). one oligonucleotide pair amplified a common segment of the n-gene and could detect various strains of ibv in allantoic fluid from inoculated chicken embryos, and in tracheal tissue preparations from experimentally infected chickens. four pairs of oligonu ... | 1999 | 26905488 |
| pathogenicity of mycoplasma imitans in mixed infection with infectious bronchitis virus in chickens. | mycoplasma imitans (mim) has been isolated from ducks, geese and partridges, and is closely related to mycoplasma gallisepticum (mg). the pathogenicity of mim for chicks was investigated in single and mixed infections with infectious bronchitis virus (ibv) by giving ibv strain m41 at 1-day-old and mim 2 days later. single infections with ibv or mim were also performed. no clinical signs or gross lesions were seen in chicks infected with mim or uninfected control chicks, but they were seen in the ... | 1999 | 26915378 |
| 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 |
| 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 |
| 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 |
| 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 |
| transmission of infectious bronchitis virus within vaccinated and unvaccinated groups of chickens. | the aim of this study was to determine whether vaccination against infectious bronchitis virus (ibv) reduces virus transmission, i.e. to test whether ibv transmission among vaccinated chickens is significantly reduced compared to that among unvaccinated chickens. in two vaccinated and two unvaccinated groups of spf chickens, a standard measure for virus transmission, the reproduction ratio (r) was determined. r is defined as the average number of new infections caused by one typical infectious i ... | 1998 | 18484273 |
| detection of specific igm antibodies to infectious bronchitis virus by an antibody-capture elisa. | the results of a new antibody-capture elisa (alpha-igm-ibv elisa), specific for igm directed against infectious bronchitis virus (ibv) show that this assay is a useful tool for diagnosing ibv infections. the data include individual results of the alpha-igm-ibv elisa in sequential spf chicken sera after vaccination with h120 and challenge with m41, the specificity is based on results of 499 spf sera, and the sensitivity on sera from experimentally vaccinated and challenged birds. also reported ar ... | 1998 | 18483980 |
| intracloacal infection with avian infectious bronchitis virus. | an infectious bronchitis virus (ibv) strain hs-91 isolated from kidneys of chicks which died of nephrosis was inoculated via the cloaca of specific pathogen-free (spf) chicks. these chicks showed more severe clinical signs, grosser kidney lesions and higher mortality than chicks inoculated with the same ibv strain via the trachea. | 1998 | 18484004 |
| epidemiological classification of infectious bronchitis virus isolated in korea between 1986 and 1997. | forty korean isolates and four reference strains of infectious bronchitis virus (ibv) were classified by reverse transcriptase-polymerase chain reaction and restriction fragment length polymorphism (rflp) analysis. each korean isolate was isolated from different types of commercial chicken flocks between 1986 and 1997. rflp patterns of an amplified dna fragment (1722 bp) containing the s1 gene of ibv digested by restriction enzyme haeiii showed that the 40 korean isolates were classified into fi ... | 1998 | 18484021 |
| development and application of an aerosol challenge method for reproduction of avian colibacillosis. | we have developed a reliable aerosol challenge method for reproduction of avian colibacillosis. this method involves intranasal administration of infectious bronchitis virus (ibv) to 1-day-old birds followed by three aerosol administrations of .e. coli at 3 to 4-day intervals. in four separate experiments there was no significant difference in virulence for a single isolate of .e. coli (e3) whereas four other field isolates of .e. coli ranged from highly virulent to avirulent. we also observed t ... | 1998 | 18484035 |
| antigenic and immunogenic characterization of infectious bronchitis virus strains isolated in china between 1986 and 1995. | eight strains of infectious bronchitis virus (ibv) were isolated between 1986 and 1995 from broilers and layers at eight different farms in four provinces in china. the viruses were isolated from flocks which suffered from either respiratory disease or nephritis and the majority had not been vaccinated against ibv. six strains were shown by monoclonal antibodies to differ from h120, connecticut and arkansas 99 strains of ibv and also to differ from each other. four of these strains were serotype ... | 1998 | 18484046 |
| 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 |
| 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 |
| 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 |