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observations on experimental infection of chicks with escherichia coli.a study was made of the pathogenesis of colibacillosis in chicks in order to develop a reproducible model for the induction of the disease by inoculation. in experimental infections with escherichia coli (e. coli), serotype 026k60 was pathogenic only during the first week of age, whereas serotype 078k80 caused lesions during the first 3 weeks. natural resistance against e. coli occurred after 1 and 3 weeks respectively. chicks were much more susceptible to intratracheal than to oral inoculation. ...197818770374
histopathological changes in the oviduct of hens producing shell-less eggs associated with precipitins to adenovirus.histopathological changes in oviducts of laying hens which produced shell-less eggs associated with the presence of precipitins to adenovirus appeared to be limited to the uterus (shell-gland). changes could not be seen macroscopically. microscopically extensive atrophy of the glandular tissue, oedema and infiltration by plasma cells and lymphocytes in the uterine villi were observed. the changes are compared with those described for infectious bronchitis virus infection.197818770379
organ culture in avian virology: a review.a review has been made of the applications of organ culture techniques in studies with viruses associated with avian disease. after a brief historical introduction, the discussion has been confined to viruses which relate directly to disease in domestic poultry, and has not included viruses which primarily affect man and other animals. the literature reviewed concerns a number of the recognised families of viruses, including poxviridae, herpetoviridae, adenoviridae, orthomyxoviridae, paramyxovir ...197818770387
studies on the antigenic relationship between an isolate (127) from the egg drop syndrome 1976 and a fowl adenovirus.birds infected with fowl adenovirus type 1 (fav-1) developed precipitating antibody to fav-1 but not to haemagglutinating virus 127 isolated from flocks with a depressed egg production syndrome. once the precipitating antibody to fav-1 was no longer detectable, the birds were then infected with 127 virus. they developed precipitating and haemagglutination-inhibiting antibody to 127 virus. they also developed precipitating antibody to the adenovirus group antigen. birds infected only with 127 vir ...197818770415
the response of the harderian gland of the fowl to antigen given by the ocular route. i. histological changes.during a study of local immunity in the fowl, histological examination was made of the harderian and lachrymal glands after eye-drop application of sheep erythrocytes (srbc), or live vaccine strains of newcastle disease virus (ndv) and infectious bronchitis virus (ibv). as judged by counts of lymphoid foci and russell body (rb-containing cells each treatment resulted in heightened lymphoid activity and increase in plasma cell numbers in both glands. however, the changes were more apparent in the ...197918770429
immunosuppressive effect of infectious bursal disease virus on vaccination against infectious bronchitis.groups of broiler chicks hatched with parental antibodies to infectious bursal disease virus (ibdv) and infectious bronchitis virus (ibv) were vaccinated against ibv at 1 day of age via the oculonasal routes and inoculated with virulent ibdv at 1, 5, 10, 15 or 20 days of age. while the non-ibdv inoculated birds were solidly immune against ibv challenge at an age of 29 days, immunity in the ibdv infected birds was depressed. this depression, which was most serious in the birds ibdv inoculated at ...197918770430
effects on biological properties of embryo-adapted beaudette strain of infectious bronchitis virus of passage through chick embryo trachea organ culture.two substrains derived from an uncloned 71st embryo (e71) passage and a cloned 71st embryo-10th chick embryo kidney cell (e71cek10) passage of the beaudette strain of avian infectious bronchitis virus were back-passaged through organ cultures of chick embryo trachea. the organ culture-passaged viruses had altered biological properties such as absence of or delayed lethality for chick embryos and lack or diminution of plaque-forming ability in chick embryo kidney monolayers but they showed no cle ...197918770459
the response of the harderian gland of the fowl to antigen given by the ocular route. ii. antibody production.after ocular administration to young chickens of sheep erythrocytes (srbc), newcastle disease virus (ndv), infectious bronchitis virus (ibv) or mycoplasma gallisepticum, homologous antibody was detected in serum and in saline extracts of harderian glands. parenteral immunisation with srbc or ndv stimulated moderately high serum antibody titres but did not evoke a measurable antibody response by the harderian gland.197918770464
viral nucleolar localisation signals determine dynamic trafficking within the nucleolus.localisation of both viral and cellular proteins to the nucleolus is determined by a variety of factors including nucleolar localisation signals (nolss), but how these signals operate is not clearly understood. the nucleolar trafficking of wild type viral proteins and chimeric proteins, which contain altered nolss, were compared to investigate the role of nolss in dynamic nucleolar trafficking. three viral proteins from diverse viruses were selected which localised to the nucleolus; the coronavi ...200818775548
a chromatographic strip test for rapid detection of one lineage of the h5 subtype of highly pathogenic avian influenza.a rapid immune colloidal gold test strip for detecting 1 lineage of the h5 subtype of highly pathogenic avian influenza was developed based on membrane chromatography with monoclonal antibodies (mabs) against hemagglutinin (ha) of the h5 subtype of avian influenza virus (aiv). bagg albino c mice that were immunized with aiv a/goose/guangdong/3/96(h5n1) yielded 4 hybridomas secreting mabs (1a6, 1b8, 3c4, and 8f6) specific for ha. monoclonal antibody 3c4 was conjugated with colloidal gold as the d ...200818776087
the histopathogenesis of the nephrosis-nephritis syndrome.chickens were infected with the australian t-strain of infectious bronchitis virus. histologically the disease started as a mild tracheo-bronchitis, accompanied by severe degenerative changes of the renal epithelia and marked inflammatory changes in the intertubular interstitium of renal cortex and medulla and in the propria and submucosa of the ureters and the main collecting ducts. there was a good correlation between the sequence of clinical signs and pathophysiological changes of the disease ...197418777251
[differentiation of haemophilus strains isolated from chickens. iii. pathogenicity tests in chickens].pathogenicity tests of 6 isolates of the haemophilus-group i (h. paragallinarum) and 8 isolates of the haemophilus-group ii isolated from chickens in the federal german republic and one strain of h. parainfluenzae isolated from man were carried out in 6-week old spf-chickens. infectious coryza (coryza contagiosa gallinarum) could be produced in chickens with all strains of group i after experimental inoculation and by contact exposure. at necropsy 3 weeks post inoculation (p.i.) organisms of gro ...197518777310
changes in the harderian gland of the chicken following conjunctival and intranasal infection with infectious bronchitis virus in one- and 20-day-old chickens.three days after conjunctival and intranasal infection with ib vaccine virus a great increase in the number of plasma cells together with an increase in vascularization was observed in the stroma of the harderian gland of chickens vaccinated either at one day of age or 20 days old. from 7 days to 21 days after vaccination a pronounced formation of follicles occurred which were composed of lymphocytes. birds exposed to diluted allantoic fluid showed a limited increase of plasma cells only; follic ...197618777328
preliminary evaluation of the haemagglutination and haemagglutination inhibition tests for avian infectious bronchitis virus.four of the 9 strains of infectious bronchitis virus which were concentrated and treated with phospholipase c type 1 showed haemagglutination activity. these strains, holte, massachusetts 41 (m41), h120 and connecticut, were distinguishable by the haemagglutination inhibition (hi) test but showed much closer relationships than could be detected by the plaque reduction (pr) test. the four haemagglutinating strains were used to compare the hi and pr titres of 17 anti sera prepared against referenc ...197618777337
observations on the effects of the h52 and h120 vaccine strains of infectious bronchitis virus in the domestic fowl.the pathogenicity of h120 and h52 infectious bronchitis vaccine viruses was compared in one-day-old and 12-weeks-old chickens. both viruses produced moderate respiratory symptoms. both were also nephrotropic but whereas h52 was accompanied by gross and microscopic kidney changes, which probably accounted for the mortality which occurred, h120 produced no change in the kidney and no mortality. both viruses caused gross and microscopic changes in the bursa of fabricius.197618777342
dropped egg production, soft shelled and shell-less eggs associated with appearance of precipitins to adenovirus in flocks of laying fowls.two outbreaks of dropped egg production and production of soft shelled and shell-less eggs are described. the outbreaks were selected from a larger number of flocks with similar problems in the field. the drop in egg production was closely correlated with the appearance of precipitins to adenovirus in the laying birds. birds were also infected with mycoplasma synoviae. a number of other infectious causes of production problems could be excluded in these outbreaks. in particular infectious bronch ...197618777355
the survival of infectious bronchitis (ib) virus in water.observations on the survival of infectious bronchitis virus in 3 mains waters showed that it survived for a much shorter period in one of them which contained a relatively high content of copper (0.2 mg/1). other factors adversely affecting survival were 5 ppm of free residual chlorine and increase in temperature over the range of 20-35 degrees c. survival of virus was prolonged in the presence of 0.1% w/v powdered skim milk (psm), 1,0% w/v poultry mash, 1,0% w/v fresh poultry droppings, rust an ...197318777388
a virus neutralization screening test: its limitations in classifying field isolates of infectious bronchitis virus.a virus neutralization screening test using a 1:5 serum dilution of known antisera against approximately 100 embryo infective doses50 of an unknown virus was used to classify field isolates of infectious bronchitis virus. such a test will detect the major antigen and antibody relationships. the weakness of a screening test is that it does not quantitatively measure the minor antigen-antibody relationships between strains which would be essential to develop a classification scheme for infectious ...197318777389
the combined influence of age of embryo and temperature and duration of incubation on the replication and yield of avian infectious bronchitis (ib) virus in the developing chick embryo.two experiments were undertaken to investigate the combined influence of the age of embryo at infection and the temperature and duration of incubation on the replication and yield of the beaudette strain of ib virus lin allantoic fluid and the chorio allantoic membrane. in general a higher titre of virus was found in the allantoic fluid and chorioallantoic membrane of living embryos than of dead ones and with continued incubation of dead embryos the titre of virus fell still further. for embryos ...197318777405
characterization and membrane gene-based phylogenetic analysis of avian infectious bronchitis virus chinese strain hh06.a chinese isolate of avian infectious bronchitis virus (ibv) designated hh06 was isolated from the kidney tissues of a chicken flock experiencing an outbreak of nephritis. in vivo pathogenicity of the ibv isolate hh06 was determined by inoculating specific pathogen-free (spf) chickens. the clinical signs and related gross lesions of hh06 infected chickens were similar with those of the field-infected chickens. spf embryonated eggs were inoculated with virus suspension for serial passage and thei ...200918792774
pathogenicity of a qx strain of infectious bronchitis virus in specific pathogen free and commercial broiler chickens, and evaluation of protection induced by a vaccination programme based on the ma5 and 4/91 serotypes.the aims of this study were firstly to evaluate the pathogenicity of an italian isolate of the qx strain of infectious bronchitis (ib) virus using 1-day-old female specific pathogen free chicks (layer type) and 1-day-old female commercial broiler type chickens, and secondly to assess the level of protection induced in these birds by a vaccination programme including the ib massachusetts and 4/91 serotype live attenuated vaccines. unvaccinated birds showed clinical signs of varying severity, pred ...200818798022
the immunoreactivity of a chimeric multi-epitope dna vaccine against ibv in chickens.epitope-based vaccines designed to induce cellular immune response and antibody responses specific for infectious bronchitis virus (ibv) are being developed as a means for increasing vaccine potency. in this study, we selected seven epitopes from the spike (s1), spike (s2), and nucleocapsid (n) protein and constructed a multi-epitope dna vaccine. the 7-day-old chickens were immunized intramuscularly with multi-epitope dna vaccine encapsulated by liposome and boosted two weeks later, and were cha ...200818840402
transmissibility of infectious bronchitis virus h120 vaccine strain among broilers under experimental conditions.the aim of this study was to quantify transmission of infectious bronchitis virus (ibv) h120 vaccine strain among broilers, and to assess whether birds that have been exposed to vaccine strain-shedding birds were protected against clinical signs after infection with a virulent strain of the same serotype. a transmission experiment and a replicate were carried out, each with six groups of commercial broilers. at day of hatch (n = 30) or at 15 days of age (n = 20), half of each group was inoculate ...200818939636
lna probe-based real-time rt-pcr for the detection of infectious bronchitis virus from the oviduct of unvaccinated and vaccinated laying hens.in the present study, lna-probe based real-time pcr was designed for the detection and absolute quantification of infectious bronchitis virus (ibv) from the oviduct of unvaccinated and vaccinated hens after ibv challenge. using a recombinant plasmid standard, the detection limit of the reaction was found to be 10 copies and independent assay runs showed reproducible ct values. amongst the unvaccinated hens, the virus could be detected between 6 and 20 days post-infection (p.i.), with a peak of v ...200918955085
comparative analysis of complete genome sequences of three avian coronaviruses reveals a novel group 3c coronavirus.in this territory-wide molecular epidemiology study of coronaviruses (covs) in hong kong involving 1,541 dead wild birds, three novel covs were identified in three different bird families (bulbul cov hku11 [bucov hku11], thrush cov hku12 [thcov hku12], and munia cov hku13 [mucov hku13]). four complete genomes of the three novel covs were sequenced. their genomes (26,396 to 26,552 bases) represent the smallest known cov genomes. in phylogenetic trees constructed using chymotrypsin-like protease ( ...200918971277
course of infection and immune responses in the respiratory tract of ibv infected broilers after superinfection with e. coli.colibacillosis results from infection with avian pathogenic escherichia coli bacteria. healthy broilers are resistant to inhaled e. coli, but previous infection with vaccine or virulent strains of infectious bronchitis virus (ibv) predisposes birds for severe colibacillosis. the aim of this study was to investigate how ibv affects the course of events upon infection with e. coli. broilers were inoculated with ibv h120 vaccine virus or virulent m41 and challenged 5 days later with e. coli 506. a ...200918976820
crystal structures of two coronavirus adp-ribose-1''-monophosphatases and their complexes with adp-ribose: a systematic structural analysis of the viral adrp domain.the coronaviruses are a large family of plus-strand rna viruses that cause a wide variety of diseases both in humans and in other organisms. the coronaviruses are composed of three main lineages and have a complex organization of nonstructural proteins (nsp's). in the coronavirus, nsp3 resides a domain with the macroh2a-like fold and adp-ribose-1"-monophosphatase (adrp) activity, which is proposed to play a regulatory role in the replication process. however, the significance of this domain for ...200918987156
progression of lesions in the respiratory tract of broilers after single infection with escherichia coli compared to superinfection with e. coli after infection with infectious bronchitis virus.the progression of escherichia coli lesions was studied in the respiratory tract of 4-week-old commercial broilers. lesions were induced after a single intratracheal e. coli infection, and after an infection with e. coli preceded 5 days earlier by an oculo-nasal and intratracheal infectious bronchitis virus (ibv) infection of either the virulent m41 strain or the h120 vaccine strain. trachea, lung and thoracic airsac lesions were examined macroscopically and microscopically. tissue samples were ...200919004507
qx genotypes of infectious bronchitis virus circulating in europe. 200819011250
formation of stable homodimer via the c-terminal alpha-helical domain of coronavirus nonstructural protein 9 is critical for its function in viral replication.coronaviruses devote more than three quarters of their coding capacity to encode two large polyproteins (1a and 1ab polyproteins), which are proteolytically processed into 15-16 mature, nonstructural replicase proteins (nsp1 to 16). these cleavage products are believed to play essential roles in replication of the giant rna genome of approximately 30 kb and transcription of a nested set of 5 to 9 subgenomic rna species by a unique discontinuous transcription mechanism. in this report, one of the ...200919022466
the preparation of chicken tracheal organ cultures for virus isolation, propagation, and titration.chicken tracheal organ cultures (tocs), comprising transverse sections of chick embryo trachea with beating cilia, have proved useful in the isolation of several respiratory viruses and as a viral assay system, using ciliostasis as the criterion for infection. a simple technique for the preparation of chicken tracheal organ cultures in glass test tubes, in which virus growth and ciliostasis can be readily observed, is described.200819057860
rt-pcr detection of avian coronaviruses of galliform birds (chicken, turkey, pheasant) and in a parrot.of the many primer combinations that we have investigated for the detection of avian coronaviruses, two have worked better than any of the others: they worked with the largest number of strains/samples of a given coronavirus and the most species of avian coronavirus, and they also produced the most sensitive detection tests. the primer combinations were: oligonucleotide pair 2bp/4bm, which is in a region of gene 1 that is moderately conserved among all species of coronavirus (1); and utr11-/utr4 ...200819057865
transient dominant selection for the modification and generation of recombinant infectious bronchitis coronaviruses.we have developed a reverse genetics system for the avian coronavirus infectious bronchitis virus (ibv) in which a full-length cdna corresponding to the ibv genome is inserted into the vaccinia virus genome under the control of a t7 promoter sequence. vaccinia virus as a vector for the full-length ibv cdna has the advantage that modifications can be introduced into the ibv cdna using homologous recombination, a method frequently used to insert and delete sequences from the vaccinia virus genome. ...200819057872
generation of recombinant coronaviruses using vaccinia virus as the cloning vector and stable cell lines containing coronaviral replicon rnas.coronavirus reverse genetic systems have become valuable tools for studying the molecular biology of coronavirus infections. they have been applied to the generation of recombinant coronaviruses, selectable replicon rnas, and coronavirus-based vectors for heterologous gene expression. here we provide a collection of protocols for the generation, cloning, and modification of full-length coronavirus cdna using vaccinia virus as a cloning vector. based on cloned coronaviral cdna, we describe the ge ...200819057873
generating antibodies to the gene 3 proteins of infectious bronchitis virus.infectious bronchitis virus (ibv), a group 3 coronavirus, produces three proteins (ibv e, ibv 3a, and ibv 3b) from subgenomic mrna 3 during infection. ibv e, a viral envelope protein, plays a role in virus budding, possibly by altering membrane morphology at the virus assembly site. in addition to this role, ibv e may also function as a viroporin, although no data from infected cells have confirmed this possibility definitively. conversely, the ibv 3a and ibv 3b proteins are nonstructural protei ...200819057877
isolation and propagation of coronaviruses in embryonated eggs.the embryonated egg is a complex structure comprising an embryo and its supporting membranes (chorioallantoic, amniotic, yolk). the developing embryo and its membranes provide the diversity of cell types that are needed for successful replication of a wide variety of different viruses. within the family coronaviridae, the embryonated egg has been used as a host system primarily for two group 3 coronaviruses, infectious bronchitis virus (ibv) and turkey coronavirus (tcov), but it also has been sh ...200819057881
infectious bronchitis virus induces acute interferon-gamma production through polyclonal stimulation of chicken leukocytes.infectious bronchitis virus, a member of the coronaviridae, is a respiratory pathogen in poultry. we found that in vitro stimulation with ibv resulted in chifn-gamma production in splenocytes of both infected birds and uninfected birds. the non-specific stimulation did not occur when other avian viruses or other coronaviruses were used or when mammalian cells were stimulated with ibv. inactivation of ibv reduced chifn-gamma production, but chifn-gamma remained elevated compared to unstimulated c ...200919070879
pathogenicity of infectious bronchitis virus isolates from ontario chickens.infectious bronchitis (ib) is one of the important viral diseases of chickens, and in spite of regular vaccination, ib is a continuous problem in canadian poultry operations. in an earlier study using sentinel chickens we determined the incidence of infectious bronchitis virus (ibv) in ontario commercial layer flocks. the objective of this study was to determine the pathogenicity of 5 nonvaccine-related ibv isolates recovered from the sentinel birds. the clinical signs, gross, and histological l ...200819086372
identification of taiwan and china-like recombinant avian infectious bronchitis viruses in taiwan.infectious bronchitis virus (ibv) infections in poultry cause great economic losses to the poultry industry worldwide. the emergence of viral variants complicates disease control. the ibv strains in taiwan were clustered into two groups, taiwan group i and taiwan group ii, based on the s1 gene. a variant was previously identified and showed a distinct s1 gene homology with other local strains. this study investigated the 3' 7.3 kb genome of eight taiwan strains isolated from 1992 to 2007. the ge ...200919100792
complete genomic sequence analysis of infectious bronchitis virus ark dpi strain and its evolution by recombination.an infectious bronchitis virus arkansas dpi (ark dpi) virulent strain was sequenced, analyzed and compared with many different ibv strains and coronaviruses. the genome of ark dpi consists of 27,620 nucleotides, excluding poly (a) tail, and comprises ten open reading frames. comparative sequence analysis of ark dpi with other ibv strains shows striking similarity to the conn, gray, jmk, and ark 99, which were circulating during that time period. furthermore, comparison of the ark genome with oth ...200819102764
existence of avian infectious bronchitis virus with a european-prevalent 4/91 genotype in japan.eight isolates of infectious bronchitis virus (ibv) were obtained from various prefectures in japan during 2003-2007 and were genetically analyzed by reverse transcriptase-polymerase chain reaction (rt-pcr) coupled with direct sequencing. these ibv isolates were classified into three genetic groups, including two that have already been reported (jp-i and jp-iii). the remaining group is related to the 4/91 (also known as 793/b) type, prevalent mainly in european countries, and has not been identi ...200819122402
comparative analysis of the sialic acid binding activity and the tropism for the respiratory epithelium of four different strains of avian infectious bronchitis virus.avian infectious bronchitis virus (ibv) is a major pathogen in commercial poultry flocks. we recently demonstrated that sialic acid serves as a receptor determinant for ibv on the tracheal epithelium. here we compared the ibv strains beaudette, 4/91, italy02, and qx for their sialic acid-binding properties. we demonstrate that sialic acid binding is important for the infection of primary chicken kidney cells and the tracheal epithelium by all four strains. there were only slight differences betw ...200919156578
induction of eggshell apex abnormalities by mycoplasma synoviae: field and experimental studies.a novel eggshell pathology, characterized by an altered shell surface, thinning, increased translucency, and cracks and breaks in the eggshell apex, has become increasingly common in layer flocks of various breeds in the netherlands. two field studies found an association between the eggshell apex abnormalities (eaa) and infection with mycoplasma synoviae. m. synoviae was isolated from the oviduct of birds that produced abnormal eggs, but not from birds in control flocks, although both affected ...200919156584
backyard chicken flocks pose a disease risk for neotropic birds in costa rica.pathogens of free-ranging chickens create a risk of disease for wild birds, some of which migrate to the united states, as well as potential economic losses for resource-poor farmers. free-roaming backyard chickens are commonly kept in shade-grown coffee plantations, habitats that attract large numbers of wild birds. the husbandry and pathogen prevalence of backyard chicken flocks in san luis, costa rica, were investigated. based on serologic evidence, newcastle disease virus, infectious laryngo ...200819166045
infectious bronchitis virus in the chicken harderian gland and lachrymal fluid: viral load, infectivity, immune cell responses, and effects of viral immunodeficiency.we compared detection of infectious bronchitis virus (ibv) by quantitative rt-pcr (qrt-pcr) in tears and trachea of ibv-infected chickens and found that quantitative detection of ibv rna in tears is more sensitive than in tracheal homogenates. furthermore, we demonstrated that ibv contained in chicken lachrymal fluid is infectious and that tears of ibv-infected chickens can be used to infect naive chickens. we compared the immune responses to ibv in the harderian gland and cecal tonsils of immun ...200819166051
isolation of 4/91 type of infectious bronchitis virus as a new variant in japan and efficacy of vaccination against 4/91 type field isolate.among field isolates of infectious bronchitis virus (ibv) from recent outbreaks, some isolates that were classified into the 4/91 genotype, by analysis of the s1 gene, have been confirmed to be a new variant in japan. to elucidate the characteristics of these isolates, pathogenicity in chicks and the efficacy of vaccines against this new variant were examined. severe respiratory symptoms were observed in 4-day-old specific pathogen free chicks inoculated with a 4/91 genotype isolate, either jp/w ...200819166052
effects of infectious bronchitis virus vaccine on the oviduct of hens.in australia, currently, all pullets reared for egg production are vaccinated with live attenuated strains of infectious bronchitis virus. various vaccines and protocols to control this viral disease have been developed, although the severity of the disease varies from place to place and flock to flock. in the present trial, the effects of vaccine strains a3 and vic s on the oviduct of laying hens were assessed by histopathology, electron microscopy, serology and also by determining the presence ...200919174178
crystal structures of the x-domains of a group-1 and a group-3 coronavirus reveal that adp-ribose-binding may not be a conserved property.the polyproteins of coronaviruses are cleaved by viral proteases into at least 15 nonstructural proteins (nsps). consisting of five domains, nsp3 is the largest of these (180-210 kda). among these domains, the so-called x-domain is believed to act as adp-ribose-1''-phosphate phosphatase or to bind poly(adp-ribose). however, here we show that the x-domain of infectious bronchitis virus (strain beaudette), a group-3 coronavirus, fails to bind adp-ribose. this is explained on the basis of the cryst ...200919177346
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.200019184793
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 ...200019184806
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 ...200019184836
detection of infectious bronchitis virus in experimentally infected chickens by an antigen-competitive elisa.an antigen-competitive enzyme-linked immunosorbent assay (ag-c-elisa) was developed for the detection of infectious bronchitis virus (ibv) antigens, m41 strain, in tissues from experimentally infected chickens, or in allantoic fluid harvested from inoculated embryonated eggs. the detection limit of ibv in the ag-c-elisa was 10(4.1) median embryo infective doses (eid(50))/well. tracheal and lung samples from chickens vaccinated with 10(2.5) eid(50) of live attenuated infectious bronchitis (h120) ...200119184876
a nomenclature for avian coronavirus isolates and the question of species status.currently, there is no agreed naming system for isolates of infectious bronchitis virus (ibv), whose host is the domestic fowl (gallus gallus domesticus). a uniform, informative system for naming ibv isolates would be very helpful. furthermore, the desirability of a single naming system has become more important with the recent discoveries that coronaviruses with genome organizations and gene sequences very similar to those of ibv have been isolated from turkeys (meleagris gallopavo) and pheasan ...200119184884
infectious bronchitis virus vaccine interferes with the replication of avian pneumovirus vaccine in domestic fowl.experiments were performed in chickens to ascertain whether application of infectious bronchitis (ib) h120 vaccine had an effect on the replication of an attenuated avian pneumovirus (apv) strain, using as indicators virus detection, humoral antibody responses and clinical protection against in vivo apv challenge. a preliminary experiment demonstrated that pharyngeal swabs were as efficient for recovery of apv as were buccal cavity swabs, and that either site was superior to swabbing the nasal c ...200119184905
detection of a coronavirus from turkey poults in europe genetically related to infectious bronchitis virus of chickens.intestinal contents of 13-day-old turkey poults in great britain were analysed as the birds showed stunting, unevenness and lameness, with 4% mortality. at post mortem examination, the main gross features were fluid caecal and intestinal contents. histological examination of tissues was largely unremarkable, apart from some sections that showed crypt dilation and flattened epithelia. negative contrast electron microscopy of caecal contents revealed virus particles, which in size and morphology h ...200119184921
epidemiology of infectious bronchitis virus in belgian broilers: a retrospective study, 1986 to 1995.infectious bronchitis virus (ibv) was isolated from each of 236 broiler flocks that had respiratory infection (86%), impaired growth, enteritis and/or nephritis (14%), over a 10-year period from 1986 to 1995 in belgium. among them, 65% of the investigated flocks had not been vaccinated against infectious bronchitis. type-specific reverse transcriptase polymerase chain reactions (rt-pcrs) were used after propagation of the isolates in embryonated eggs in order to detect and differentiate massachu ...200119184926
protection of chickens against renal damage caused by a nephropathogenic infectious bronchitis virus.the ability of the infectious bronchitis (ib) ma5 and 4/91 live-attenuated vaccines to protect against kidney damage caused by a nephropathogenic strain of ib virus (b1648) was investigated. protection parameters considered were gross and microscopic renal pathology, and the use of a polymerase chain reaction to detect ib rna in kidney tissue. by each parameter, ma5 vaccine alone provided poor protection, but 4/91 alone or the combined program both protected well.200119184927
safety and efficacy of water-in-oil-in-water emulsion vaccines containing newcastle disease virus haemagglutinin-neuraminidase glycoprotein.subunit vaccines containing haemagglutinin-neuraminidase (hn) glycoprotein of newcastle disease virus (ndv), formulated as water-in-oil-in-water (w/o/w) emulsions, were prepared. first, the suitable constituents of a w/o/w emulsion adjuvant were investigated with polyvalent vaccines using ndv, infectious bronchitis virus and haemophilus paragallinarum. the w/o/w emulsion adjuvant, composed of the antigen in phosphate-buffered saline (pbs), liquid paraffin, squalene, diglyceryl monooleate, polyso ...200119184940
sequence analysis of nephropathogenic infectious bronchitis virus strains of the massachusetts genotype in beijing.the first 440 nucleotides of the s1 part of the spike protein (s) gene of three nephropathogenic infection bronchitis virus (ibv) strains (bj1, bj2 and bj3), isolated from three rural chicken farms of beijing with outbreaks of avian infectious bronchitis, were sequenced after reverse transcriptasenested polymerase chain reaction amplification. the sequence data were analyzed and compared with the standard ibv strains m41, beaudette, vaccine strain h120 and chinese vaccine strain d41. the three i ...200119184943
innovation and discovery: the application of nucleic acid-based technology to avian virus detection and characterization.polymerase chain reaction (pcr)-based approaches to the detection, differentiation and characterization of avian pathogens continue to be developed and refined. the pcrs, or reverse transcriptase-pcrs, may be general, designed to detect all or most variants of a pathogen, or to be serotype, genotype or pathotype specific. progress is being made with respect to making nucleic acid approaches more suitable for use in diagnostic laboratories. robotic workstations are now available for extraction of ...200119184952
immunohistochemistry for detection of avian infectious bronchitis virus strain m41 in the proventriculus and nervous system of experimentally infected chicken embryos.infectious bronchitis virus primarily induces a disease of the respiratory system, different ibv strains may show variable tissue tropisms and also affect the oviduct and the kidneys. proventriculitis was also associated with some new ibv strains. aim of this study was to investigate by immunohistochemistry (ihc) the tissue tropism of avian infectious bronchitis virus (ibv) strain m41 in experimentally infected chicken embryos.200919196466
identification of sequence changes responsible for the attenuation of avian infectious bronchitis virus strain arkansas dpi.infectious bronchitis virus (ibv) is the causal agent of infectious bronchitis, which still remains one of the most important poultry diseases worldwide because of numerous serotypes and variants. a virulent strain of ibv, isolated from arkansas (ark), was propagated in embryonated eggs (ark dpi 11). following 101 serial passages in embryonated eggs, an attenuated strain of ibv was established (ark dpi 101) that does not induce histopathological lesions in the tracheae of infected chicks. to ide ...200919219402
sequence and phylogenetic analysis of s1, s2, m, and n genes of infectious bronchitis virus isolates from malaysia.two malaysian infectious bronchitis virus isolates, mh5365/95 and v9/04 were characterized based on sequence and phylogenetic analyses of s1, s2, m, and n genes. nucleotide sequence alignments revealed many point mutations, short deletions, and insertions in s1 region of both ibv isolates. phylogenetic analysis of s1 gene and sequences analysis of m gene indicated that mh5365/95 and v9/04 belong to non-massachusetts strain. however, both isolates share only 77% identity. analysis based on s1 gen ...200919242786
interaction of the coronavirus infectious bronchitis virus membrane protein with beta-actin and its implication in virion assembly and budding.coronavirus m protein is an essential component of virion and plays pivotal roles in virion assembly, budding and maturation. the m protein is integrated into the viral envelope with three transmembrane domains flanked by a short amino-terminal ectodomain and a large carboxy-terminal endodomain. in this study, we showed co-purification of the m protein from coronavirus infectious bronchitis virus (ibv) with actin. to understand the cellular factors that may be involved in virion assembly, buddin ...200919287488
rapid detection and non-subjective characterisation of infectious bronchitis virus isolates using high-resolution melt curve analysis and a mathematical model.infectious bronchitis virus (ibv) is a coronavirus that causes upper respiratory, renal and/or reproductive diseases with high morbidity in poultry. classification of ibv is important for implementation of vaccination strategies to control the disease in commercial poultry. currently, the lengthy process of sequence analysis of the ibv s1 gene is considered the gold standard for ibv strain identification, with a high nucleotide identity (e.g. > or =95%) indicating related strains. however, this ...200919301093
molecular characterization of avian infectious bronchitis virus strains from outbreaks in argentina (2001-2008).twenty infectious bronchitis virus isolates were recovered from broilers and layers in different outbreaks amongst commercial poultry flocks in different geographic regions of argentina from 2001 to 2008. the viruses were isolated from the tracheas, lungs, and caecal tonsils of birds that were showing respiratory signs. further analysis based on their nucleotide and amino acid sequences in hypervariable region (hvr) 1 and the intervening sequence including hvrs 1 and 2 (hvr1/2) of the s1 gene wa ...200919322714
infectious bronchitis virus in jordanian chickens: seroprevalence and detection.infectious bronchitis (ib) is one of the most important viral diseases of poultry; it causes major economic losses to the poultry industry. this study was conducted to investigate the prevalence of infectious bronchitis virus (ibv) in commercial chicken flocks in jordan. serum samples from 70 commercial chicken flocks (40 broilers, 18 layers, and 12 broiler breeders) free from respiratory disease were collected and screened for the presence of massachusetts-41 (m-41), d274, and 4/91 strain antig ...200919337618
[use of multiplex pcr method with real-time detection for differential diagnosis of respiratory viral infections].multiplex real-time polymerase chain reaction test-system with fluorescent detection (rt-pcr) for simultaneous identification of main agents of acute respiratory viral infections: influenza a (iav) and b viruses (ibv), parainfluenza viruses types 1, 2, 3, 4 (piv 1 - 4), adenoviruses (adv), respiratory syncitial virus (rsv), rhinoviruses (rv) and enteroviruses (ev), in presence internal positive control (ipc) represented by vaccine strain of rubella virus ra 27/3. using multiplex rt-pcr method, r ...200919338239
genetic diversity of avian infectious bronchitis viruses in japan based on analysis of s2 glycoprotein gene.to understand the genetic diversity of the s2 gene of infectious bronchitis viruses (ibv) isolated in japan, we determined the nucleotide sequences of these ibvs using the reverse transcriptase polymerase chain reaction method coupled with direct sequencing. ibv isolated in japan were classified into six different groups by phylogenetic analysis based on the s2 gene. however, the classification based on the s2 gene of ibv isolated in japan was different for some of the strains from those obtaine ...200919346695
broadly targeted multiprobe qpcr for detection of coronaviruses: coronavirus is common among mallard ducks (anas platyrhynchos).coronaviruses (covs) can cause trivial or fatal disease in humans and in animals. detection methods for a wide range of covs are needed, to understand viral evolution, host range, transmission and maintenance in reservoirs. a new concept, "multiprobe qpcr", which uses a balanced mixture of competing discrete non- or moderately degenerated nuclease degradable (taqman) probes was employed. it provides a broadly targeted and rational single tube real-time reverse transcription pcr ("nqpcr") for the ...200919406168
towards construction of viral vectors based on avian coronavirus infectious bronchitis virus for gene delivery and vaccine development.manipulation of the coronavirus genome to accommodate and express foreign genes is an attractive approach for gene delivery and vaccine development. by using an infectious cloning system developed recently for the avian coronavirus infectious bronchitis virus (ibv), the enhanced green fluorescent protein (egfp) gene, the firefly luciferase gene and several host and viral genes (eif3f, sars orf6, dengue virus 1 core protein gene) were inserted into various positions of the ibv genome, and the eff ...200919409420
identification of in vivo-interacting domains of the murine coronavirus nucleocapsid protein.the coronavirus nucleocapsid protein (n), together with the large, positive-strand rna viral genome, forms a helically symmetric nucleocapsid. this ribonucleoprotein structure becomes packaged into virions through association with the carboxy-terminal endodomain of the membrane protein (m), which is the principal constituent of the virion envelope. previous work with the prototype coronavirus mouse hepatitis virus (mhv) has shown that a major determinant of the n-m interaction maps to the carbox ...200919420077
rapid subtyping of h9n2 influenza virus by a triple reverse transcription polymerase chain reaction.the aim of this study was to develop a rapid, cost-saving triple reverse transcription polymerase chain reaction (triple rt-pcr) for subtyping h9n2 avian influenza viruses (aivs). the three primer pairs for amplification of target sequences of nucleoprotein (np), hemagglutinin (ha) and neuraminidase (na) genes, respectively, were designed for subtyping the viruses in the triple rt-pcr. the sensitivity of triple rt-pcr was found to be 10(2) copies per reaction for each of np, h9 and n2 gene. the ...200919428570
massachusetts live vaccination protects against a novel infectious bronchitis virus s1 genotype dmv/5642/06.four infectious bronchitis virus (ibv) isolates were recovered from commercial broiler chicken flocks located on the delmarva peninsula (east coast of the united states) in the spring of 2006. sequence analysis of the s1 subunit of the spike glycoprotein gene showed the four isolates were highly related to each other (> or = 99.6% nucleotide identity; > or = 98.9% amino acid identity). basic local alignment search tool analysis indicated the highest s1 amino acid identity of isolate dmv/5642/06, ...200919432014
comparative analysis of the effect of glycyrrhizin diammonium and lithium chloride on infectious bronchitis virus infection in vitro.the effects of glycyrrhizin diammonium (gd) and lithium chloride (licl) on cell infection by avian infectious bronchitis virus (ibv) were investigated using cytopathic effect observation, plaque-reduction assay and reverse transcriptase-polymerase chain reaction. the anti-viral effect of gd and licl on virus, on virus-infected cells or on cells pre-treated by both drugs was analysed, respectively. our results showed that gd had a direct antiviral activity, leading to complete inhibition of cell ...200919468938
genetic analysis of the s1 gene of 4/91 type infectious bronchitis virus isolated in japan.s1 gene sequences for infectious bronchitis virus (ibv) strains of the 4/91 genotype (commonly called 793b) isolated from field outbreaks in japan were analyzed to ascertain the relationship to 4/91 vaccine strain. three field isolates (jp/wakayama/2003, jp/iwate/2005 and jp/saitama/2006) from flocks not immunized with a 4/91 type live ibv vaccine and one isolate (jp/wakayama-2/2004) from a flock immunized with a 4/91 type live vaccine were examined. the amino acid identities among jp/wakayama/2 ...200919498283
altered pathogenicity, immunogenicity, tissue tropism and 3'-7kb region sequence of an avian infectious bronchitis coronavirus strain after serial passage in embryos.in this study, we attenuated a chinese lx4-type nephropathogenic infectious bronchitis virus (ibv) strain, ck/ch/lhlj/04v, by serial passage in embryonated chicken eggs. based on sequence analysis of the 3'-7kb region, the ck/ch/lhlj/04v virus population contained subpopulations with a mixture of genetic mutants. the titers of the virus increased gradually during serial passage, but the replication capacity decreased in chickens. the virus was partially attenuated at passage 40 (p40) and p70, an ...200919523910
coadministration of chicken gm-csf with a dna vaccine expressing infectious bronchitis virus (ibv) s1 glycoprotein enhances the specific immune response and protects against ibv infection.various approaches have been developed to improve the efficacy of dna vaccination, such as the use of plasmids expressing cytokines as molecular adjuvants. the purpose of the present study was to determine whether co-administration of a plasmid containing a chicken granulocyte-macrophage colony-stimulating factor (gm-csf) gene and a plasmid containing the s1 gene of infectious bronchitis virus (ibv) could enhance the immune response and protection efficacy in chickens against challenge by virule ...200919543689
proteolytic activation of the spike protein at a novel rrrr/s motif is implicated in furin-dependent entry, syncytium formation, and infectivity of coronavirus infectious bronchitis virus in cultured cells.the spike (s) protein of the coronavirus (cov) infectious bronchitis virus (ibv) is cleaved into s1 and s2 subunits at the furin consensus motif rrfrr(537)/s in virus-infected cells. in this study, we observe that the s2 subunit of the ibv beaudette strain is additionally cleaved at the second furin site (rrrr(690)/s) in cells expressing s constructs and in virus-infected cells. detailed time course experiments showed that a peptide furin inhibitor, decanoyl-arg-val-lys-arg-chloromethylketone, b ...200919553314
the protective immune response against infectious bronchitis virus induced by multi-epitope based peptide vaccines.peptide vaccine was found to be an effective and powerful approach to a variety of pathogens. to explore multi-epitope based peptide vaccines against infectious bronchitis virus (ibv), the immunogenic peptides were fused to the 3' terminal of glutathione s transferase gene (gst) and expressed in escherichia coli. elisa and western blot analysis showed that the purified fusion proteins had excellent immune activity with chicken anti-ibv serum. during the vaccination course, the candidate peptide ...200919584555
molecular characterization and pathogenicity of infectious bronchitis coronaviruses: complicated evolution and epidemiology in china caused by cocirculation of multiple types of infectious bronchitis coronaviruses.to monitor and study the molecular epidemiology, evolution and pathogenicity of infectious bronchitis viruses (ibvs) in china in recent years and further our knowledge of the evolution of ibvs.200919590226
genetically diverse coronaviruses in wild bird populations of northern england.infectious bronchitis virus (ibv) causes a costly respiratory viral disease of chickens. the role of wild birds in the epidemiology of ibv is poorly understood. we detected diverse coronaviruses by pcr in wildfowl and wading birds in england. sequence analysis showed some viruses to be related to ibv.200919624927
characterization of a new genotype and serotype of infectious bronchitis virus in western africa.between 2002 and 2007, more than 1000 chickens from commercial farms, live bird markets and backyard farms in nigeria and niger were tested for the presence of the infectious bronchitis virus (ibv) genome. phylogenetic analysis of full-length sequences of the spike 1 (s1) gene revealed a new genotype of ibv that we refer to as 'ibadan'. the minimum genetic distance to the closest 'non-ibadan' strains (uk/7/93 at the nucleotide level; h120 and m41 at the amino acid level) reached 24 and 32 % at t ...200919625463
infectious bronchitis virus field vaccination coverage and persistence of arkansas-type viruses in commercial broilers.to determine the coverage of infectious bronchitis virus (ibv) vaccine field boost in commercial broilers, estimate the relative amount of vaccine virus in the trachea, and follow the clearance of the vaccine, we collected approximately 100 tracheal swabs at various times postvaccination from 10 different flocks and used real-time reverse transcriptase-pcr (rt-pcr) to detect the virus. this allowed us to detect vaccine virus in as few as 3% of the birds in a flock of 20,000 birds with a 95% conf ...200919630221
cpg oligodeoxynucleotides activate innate immune response that suppresses infectious bronchitis virus replication in chicken embryos.the understanding of innate immune modulation by pathogens and immune-modulating agents, including synthetic oligodeoxynucleotides (cpg odns), has offered several new approaches to improve prophylactic and therapeutic strategies against infectious diseases in humans and animals. however, in this regard not much work has been done in avian medicine. in the present study, we analyzed the kinetics of interferon (ifn), cytokine, and chemokine mrna expression in chicken embryonic spleen at 6 hr, 24 h ...200919630234
expression, crystallization and preliminary x-ray diffraction analysis of the n-terminal domain of nsp2 from avian infectious bronchitis virus.avian infectious bronchitis virus (ibv) is a prototype of the group iii coronaviruses and encodes 15 nonstructural proteins which make up the transcription/replication machinery. the nsp2 protein from ibv has a unique and novel sequence and has no experimentally confirmed function in replication, whereas it has been proposed to be crucial for early viral infection and may inhibit the early host immune response. the gene that encodes a double-mutant ibv nsp2 n-terminal domain (residues 9-393 of t ...200919652340
serological studies of infectious bronchitis vaccines against japanese field isolates of homologous and heterologous genotypes.the genetic diversity of the partial s1 gene involving the hyper variable region for infectious bronchitis (ib) vaccine strains in japan were compared with those of ib virus isolated from the field in japan. field isolates have mainly been classified into three major genotypes, jp-i, jp-ii and jp-iii, since 2003; however, the 4/91 genotype was detected from recent field isolates in japan. the virus neutralization (vn) activity with vaccine immunized serum was investigated to evaluate the protect ...200919652475
detection and molecular characterization of infectious bronchitis virus isolated from recent outbreaks in broiler flocks in thailand.thirteen field isolates of infectious bronchitis virus (ibv) were isolated from broiler flocks in thailand between january and june 2008. the 878-bp of the s1 gene covering a hypervariable region was amplified and sequenced. phylogenetic analysis based on that region revealed that these viruses were separated into two groups (i and ii). ibv isolates in group i were not related to other ibv strains published in the genbank database. group 1 nucleotide sequence identities were less than 85% and am ...200919687622
comparative evaluation of real-time pcr and conventional rt-pcr during a 2 year surveillance for influenza and respiratory syncytial virus among children with acute respiratory infections in kolkata, india, reveals a distinct seasonality of infection.acute respiratory tract infections (artis) are one of the most common causes of morbidity and mortality in young children worldwide. influenza virus and respiratory syncytial virus (rsv) are the predominant aetiological agents during seasonal epidemics, and thus rapid and sensitive molecular tests for screening for such agents and timely identification of epidemics are required. this study compared real-time quantitative pcr (qpcr) with conventional rt-pcr for parallel identification of influenz ...200919713363
detection and differentiation of four poultry diseases using asymmetric reverse transcription polymerase chain reaction in combination with oligonucleotide microarrays.asymmetric reverse transcription polymerase chain reaction (rt-pcr) and microarrays were combined to distinguish 4 viruses, including avian influenza virus (aiv), newcastle disease virus (ndv), infectious bronchitis virus (ibv), and infectious bursal disease virus (ibdv), and hemagglutinin (ha) subtypes h5, h7, and h9, and neuraminidase (na) subtypes n1 and n2 of aiv. the aiv matrix protein (m), and ha and na genes, ibv nucleoprotein (np) gene, ndv np gene, and ibdv a fragment gene were cloned i ...200919737757
inhibition of protein kinase r activation and upregulation of gadd34 expression play a synergistic role in facilitating coronavirus replication by maintaining de novo protein synthesis in virus-infected cells.a diversity of strategies is evolved by rna viruses to manipulate the host translation machinery in order to create an optimal environment for viral replication and progeny production. one of the common viral targets is the alpha subunit of eukaryotic initiation factor 2 (eif-2alpha). in this report, we show that phosphorylation of eif-2alpha was severely suppressed in human and animal cells infected with the coronavirus infectious bronchitis virus (ibv). to understand whether this suppression i ...200919776135
development of a real-time taqman rt-pcr assay for the detection of infectious bronchitis virus in chickens, and comparison of rt-pcr and virus isolation.a sensitive and specific method for the diagnosis of infectious bronchitis virus (ibv) is of great importance. in this study the development of a real-time taqman rt-pcr targeting the highly conserved nucleocapsid (n) gene of ibv and including an internal pcr control is described. the assay was specific for ibv and did not detect other avian pathogens, including turkey coronaviruses. a comparative limit of detection was determined for m41, an embryo-adapted strain, and is/885/00, a poorly embryo ...201019781572
protection of chickens against infectious bronchitis by a recombinant fowlpox virus co-expressing ibv-s1 and chicken ifngamma.a fowlpox virus expressing the chicken infectious bronchitis virus (ibv) s1 gene of the lx4 strain (rfpv-ibvs1) and a fowlpox virus co-expressing the s1 gene and the chicken type ii interferon gene (rfpv-ibvs1-chifngamma) were constructed. these viruses were assessed for their immunological efficacy on specific-pathogen-free (spf) chickens challenged with a virulent ibv. although the antibody levels in the rfpv-ibvs1-chifngamma-vaccinated group were lower than those in the attenuated live ib vac ...200919786144
the infection of primary avian tracheal epithelial cells with infectious bronchitis virus.here we introduce a culture system for the isolation, passaging and amplification of avian tracheal epithelial (ate) cells. the ate medium, which contains chicken embryo extract and fetal bovine serum, supports the growth of ciliated cells, goblet cells and basal cells from chicken tracheas on fibronectin- or matrigel-coated dishes. non-epithelial cells make up less than 10% of the total population. we further show that ate cells support the replication and spread of infectious bronchitis virus ...201019793537
vaccine efficacy against ontario isolates of infectious bronchitis virus.infectious bronchitis (ib) is an economically important viral disease with worldwide distribution. every country with an intensive poultry industry has infectious bronchitis virus (ibv). the virus rapidly spreads from bird to bird through horizontal transmission by aerosol or ingestion. sentinel bird studies were carried out in southern ontario and ibv has been isolated from layer flocks. genetic analysis of the s1 region of the strains showed that they were not vaccine related. the pathogenicit ...200919794894
the replicase gene of avian coronavirus infectious bronchitis virus is a determinant of pathogenicity.we have previously demonstrated that the replacement of the s gene from an avirulent strain (beaudette) of infectious bronchitis virus (ibv) with an s gene from a virulent strain (m41) resulted in a recombinant virus (beaur-m41(s)) with the in vitro cell tropism of the virulent virus but that was still avirulent. in order to investigate whether any of the other structural or accessory genes played a role in pathogenicity we have now replaced these from the beaudette strain with those from m41. t ...200919816578
reverse transcription loop-mediated isothermal amplification for the rapid detection of infectious bronchitis virus in infected chicken tissues.a reverse transcription loop-mediated isothermal amplification (rt-lamp) assay targeting the nucleocapsid phosphoprotein gene of infectious bronchitis virus (ibv) was developed. the detection limits for the ibv rt-lamp assay were 10(1) 50% egg infection dose (eid(50)) per 50 microl of titrated viruses and no cross-reaction of ibv rt-lamp was found when tested with other viruses including newcastle disease virus (ndv), avian reovirus (arv), and infectious laryngotrachietis virus (iltv) due to the ...201019835950
detection and molecular characterization of gene 3 and 5 of turkey coronavirus from turkeys with severe enteritis in brazil.turkey coronavirus (tcov) is a causative agent associated with poult enteritis and mortality syndrome (pems) in turkeys worldwide. the disease is an acute, highly contagious enteric disease that is characterized by depression, anorexia, diarrhea, and high mortality in commercial turkey flocks. the presence of tcov in 12 intestinal-content samples, from turkey flocks aged between 10 and 104 days and exhibiting severe enteritis, was monitored during the period of 2004 to 2006. tcov detection was a ...200919848072
characterization of new variants of avian infectious bronchitis virus in tunisia.three infectious bronchitis virus (ibv) strains, isolated from suspected tunisian broiler flocks, were characterized as variant viruses using genotyping and serotyping techniques. they were compared with commonly used vaccine strains, including 793/b, d274, and massachusetts types. reverse transcription-pcr-restriction fragment length polymorphism, nucleotide sequencing, and genbank blast database analyses of the hypervariable region of the s1 subunit of the virus spike gene showed that the thre ...200919848084
identification of a novel linear b-cell epitope in the m protein of avian infectious bronchitis coronaviruses.this report describes the identification of a novel linear b-cell epitope at the c-terminus of the membrane (m) protein of avian infectious bronchitis virus (ibv). a monoclonal antibody (mab) (designated as 15e2) against the ibv m protein was prepared and a series of 14 partially-overlapping fragments of the ibv m gene were expressed with a gst tag. these peptides were subjected to enzyme-linked immunosorbent assay (elisa) and western blotting analysis using mab 15e2 to identify the epitope. a l ...200919851732
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