| studies on avian infectious bronchitis virus (ibv). i. resistance of ibv to chemical and physical treatments. | the resistance of avian infectious bronchitis virus (ibv) to several chemical and physical treatments was studied. ten strains, including four japanese strains, were used. 1. all strains were sensitive to heating at 56 degrees c for 15 minutes; although two of them, kh and massachusetts-41, were resistant to heating at 45 degrees c for 90 minutes. 2. all strains were resistant to ph 3.0 and most of the strains were sensitive to ph 11.0. 3. all strains were completely inactivated by chloroform an ... | 1979 | 39536 |
| effect of incubation temperature on infectivity titration of mouse brain-passaged avian infectious bronchitis virus in laboratory host systems. | mouse brain-passaged infectious bronchitis virus (ibv) could not be assayed for its infectivity at 39.5 degrees c, but could be so at 37 degrees c and 39.5 degrees c. antigen accumulation was not detected by immunofluorescence in cek cells infected with mouse brain-passaged ibv at 39.5 degrees c, perhaps due to the difference in the cellular environments. | 1979 | 42299 |
| use of the indirect fluorescent antibody method for detecting antibodies to infectious bronchitis virus in chickens serum. | | 1975 | 167061 |
| letter: infectious bronchitis in vaccinated poultry. | | 1975 | 167505 |
| two new isolants of infectious bronchitis virus with polyvalent immunogenicity. | the immunizing capacity of two new field isolants of avian infectious bronchitis virus (ibv) was tested in vivo. chickens vaccinated with either isolant resisted challenge with 6 serotypes of ibv, including some of the types most commonly isolated from chickens. the two new isolants, identified herein as california "g" and california "s," appear to be immunologically different from each other and from the other 6 types tested. the polyvalent immunogenicity of both g and s is noteworthy, and pote ... | 1975 | 168851 |
| identification of infectious bronchitis virus by interference with the b-1 isolant of newcastle disease virus. waxing and waning of interference. | the massachusetts and the connecticut types of infectious bronchitis virus (ibv) were identified by interference in embryonating chicken eggs (ece) with the production of hemagglutinin by the b-1 isolant of newcastle disease virus (ndv). this interference test appears to be specific because the above interference was eliminated by adding type-specific anti-ibv serum to the ibv-ndv system; however, interference was not detectable when fowlpox virus (fpv) and infectious laryngotracheitis virus (lt ... | 1975 | 168852 |
| serotyping of avian infectious bronchitis viruses by the virus-neutralization test. | the antigenic relationships of 12 strains of infectious bronchitis virus (ibv) were evaluated by a virus-neutralization procedure similar to that used in typing human rhinoviruses. such a procedure consists of reciprocal neutralization tests performed by reacting 32-320 eid50 or plaque-forming units of virus with 20 antibody units of antiserum. eight serologic groups were identified by chicken embryo assay, and 4 by plaque-reduction (90%). in general, serologic groupings were not distinct but re ... | 1975 | 169804 |
| vaccination of young chickens with live vaccine against some new zealand isolates of infectious bronchitis virus. | | 1975 | 170569 |
| comparison of a microneutralization test in cell culture and virus neutralization test in embryonated eggs for determining infectious bronchitis virus antibodies. | a microneutralization test (mnt) system utilizing cytopathic effect end points was effective in determing neutralization indexes for infectious bronchitis virus antibodies. the system is reproducible within 1 index unit at the 95% level of probability. comparison of the mnt to tests in eggs resulted in a positive correlation (b =0.81), which was significant (p greater than 0.01). the quantitative dose-response relationship of the mnt is linear (p greater than 0.005), with the 95% prediction limi ... | 1976 | 176174 |
| heterogeneity of infectious bronchitis virus grown in eggs. | egg-grown infectious bronchitis virus, strain beaudette, was concentrated and centrifuged on sucrose density gradients to separate the virus into five peaks with densities of 1.144, 1.160, 1.172, 1.191 and 1.218 g/cm3. all peaks retained infectivity, complement fixation activity and were labelled with 3h-uridine. morphologically the densest peak consisted of very large virus particles and amorphous material, the other peaks consisted of mainly intact particles although small differences in size ... | 1976 | 176969 |
| identification of seven isolants of infectious bronchitis virus by interference with the b-1 isolant of newcastle disease virus. | seven isolants of infectious bronchitis virus (ibv) interfered with the development of hemagglutinins (ha) by the b-1 isolant of newcaslte disease virus (ndv) in eggs previously inoculated with these ibv isolants. the i50 [defined as the minimum amount of ibv needed to produce, upon inoculation in embryonating chicken eggs (ece), ha interference in 50% of these ece reioculated 10 hr later with 10(2,41 eid50 (ha) of the b-1 strain of ndv] was less than 1 eid50. the interference was considered spe ... | 1976 | 176988 |
| new strains of infectious bronchitis virus isolated in maine. | twelve ibv isolants from diseased chickens in maine were studied by serum-neutralization tests in chicken tracheal culture. six isolants were neutralized by mass-type antisera. the serum-neutralizing characteristics of six other isolants from vaccine breaks differed from any of the standard ibv viruses and appear to comprise three new strains, maine 209, 212,and 246. the data provide additional evidence that strains of ibv responsible for disease probably vary from region to region and that the ... | 1976 | 176989 |
| cross-protection studies with a holland strain (noblis h-52) of infectious bronchitis virus. | | 1976 | 176990 |
| immunity to infectious bronchitis virus from spray vaccination with derivatives of a holland strain. | study was made of the protection of chickens from spray vaccination with different modifications of a holland (h) strain of infectious bronchitis virus (ibv). noted in each trial were the virus-serum-neutralizing antibody titers induced and the virulence of the vaccine virus at different passage levels. protection against respiratory signs was good from challenge with a homologous virus serotype as well as with 5 heterologous ibv isolates. this occurred from vaccinating day-old chicks possessing ... | 1976 | 176991 |
| the isolation and some biological properties of a variant avian infectious bronchitis virus. | a virus isolated from a respiratory disease in chickens was identified as infectious bronchitis virus (ibv). by serum neutralisation tests the virus was shown to be serologically distinct from the massachusetts type but to possess a one-way relationship with the connecticut type. experimentally, it caused a relatively mild respiratory disease in baby chicks. vaccination of young chicks with h-120 massachusetts ibv vaccine afforded a high degree of protection against challenge with the isolate. s ... | 1976 | 179183 |
| vaccination and revaccination with a holland (h) strain of infectious bronchitis virus. | one-day-old chickens possessing maternally derived immunity to massachusetts-type infectious bronchitis virus (ibv) were vaccinated by the eyedrop route with a holland (h) ibv strain of the massachusetts type. vaccination was done with the 72nd and 92nd passages in chicken embryos. attenuation of the virus was done in the authors' laboratory. four weeks postvaccination the immunity was challenged with 8 different ibv serotypes. a broad spectrum of protection from respiratory signs was obtained i ... | 1976 | 180959 |
| letter: protection by ibv vaccine. | | 1976 | 181893 |
| [the influence of infectious bronchitis virus on egg production, fertility, hatchability and mortality rate in chickens (author's transl)]. | in 35 flocks comprising almost 100,000 white plymouth rock birds producing hatching eggs, infectious bronchitis (ib) caused a decline in production which appeared to be connected with the age of the birds, when the outbreak started (table i). in outbreaks of ib in pullets 3-4 weeks before they are ready to lay there is a considerable risk of delay of production and a generally too low yield (fig 1). egg laying birds, 25-34 weeks of age, suffered a drop in production from 20-80% (on an average 40 ... | 1976 | 183182 |
| serologic differences between strains of infectious bronchitis virus from new zealand, australia, and the united states. | the antigenic relationships of strains of infectious bronchitis virus from new zealand, australia, and the united states were evaluated by a virus-neutralization procedure similar to that used in typing human rhinoviruses. the four previously described new zealand serotypes were antigenically distinct from all the other strains tested. | 1976 | 183648 |
| organ culture studies on the efficiency of infection of chicken tissues with avian infectious bronchitis virus. | long-term organ cultures of a range of tissues collected from specific pathogen-free chickens were employed to determine their susceptibility, and their capacity for subsequent virus production, following inoculation with avian infectious bronchitis (aib) virus. when inoculated with approximately 2-0 log10 median ciliostatic doses (cd50) of a classical highly egg-adapted vaccine strain (h120) of aib virus, 9 of 23 tissues were shown to be susceptible, namely the nasal turbinates, trachea, air sa ... | 1976 | 183805 |
| electron microscope observations on the entry of avian infectious bronchitis virus into susceptible cells. | infectious bronchitis virus was observed to enter cells of chicken chorioallantoic membrane by viropexis. there was no support for the suggestion that entry took place by fusion of viral and plasma membranes. the results of electron microscopy showed that virus attachment occurred both at 4 degrees and at 37 degrees c. viropexis was not observed until the preparations were warmed. similar results were obtained using chicken kidney cells. quantitative data obtained from a plaque counting system e ... | 1976 | 187152 |
| a study of two avian adenovirus serotypes alone or in combination with avian infectious bronchitis in day-old chicks. | | 1977 | 190275 |
| the histopathology of infectious bronchitis in fowls infected with a nephrotropic "t" strain of virus. | the histopathology of the infectious bronchitis caused by the cumming "t" strain of virus is described in fowls exposed to infection by an aerosol method. desquamation of the ciliated and glandular epithelium throughout the trachea was seen 24 hours after exposure to virus. this was followed by rapid proliferation presumably of residual basal cells with the production of a stratified undifferentiated epithelial covering. small areas of the tracheal submucosa showed lymphocytic infiltration by th ... | 1976 | 186001 |
| isolation of infectious bronchitis virus from broiler chickens in chile. | an infectious-bronchitis-like virus was isolated from 6-week-old broiler chickens unvaccinated with infectious bronchitis virus (ibv). the isolate produced lesions in embryonating chicken eggs (ece) and clinical signs in birds characteristic of ibv. serum-neutralization and agar-gel diffusion tests demonstrated the serological relationship of this isolate to ibv. | 1976 | 183652 |
| correlation of cytopathic effect, fluorescent-antibody microneutralization, and plaque reduction test results for determining avian infectious bronchitis virus antibodies. | a microneutralization fluorescent-antibody (mfa) test was effective in determining the level of antibodies to avian infectious bronchitis virus. a comparison of the mfa test with the cytopathic effect microneutralization (mnt) test and 50% plaque reduction (pr) test resulted in positive correlations that were significant (p less than 0.001). the pr test was more sensitive than either the mfa or the mnt test, but there was no significant difference between the sensitivities of the mfa and mnt tes ... | 1977 | 192758 |
| presence of infectious polyadenylated rna in coronavirus avian bronchitis virus. | | 1977 | 193262 |
| comparative tests on safety and potency of iba vaccines. | during a comparative test on the pathogenicity and immunogenicity of a non-adapted and an embryo-adapted ida virus, following observations were made: 1) the non-adapted virus remained pathogenic as determined by weight loss and bursal lesions. clinical signs and mortality did not occur. a change in the virulence did not occur during back passages; 2) the immunosuppressive effect of the non-adapted virus was diminished by maternal antibodies; 3) the embryo-adapted virus produced little pathogenic ... | 1976 | 182590 |
| the proposed international standard for infectious bronchitis vaccine (live). | an h-120 strain of infectious bronchitis virus was prepared in a form suitable to serve as an international standard for infectious bronchitis vaccine (live). accelerated degradation studies carried out on this vaccine showed it to be of suitable stability to serve as a standard. results from a collaborative assay involving ten laboratories demonstrated that the proposed standard reduced the variation in virus titrations both within and between laboratories. this assay also showed that firstly ... | 1976 | 182587 |
| local immunity in newcastle disease: some recent experiments. | following primary exposure by the ocular route to lentogenic newcastle disease virus (ndv) the lacrymal fluid, saliva and tracheal washes of three-week old specific pathogen free chickens acquired specific virus-neutralizing activity which considerably exceeded transudation of circulating antibody. all three secretions contain iga which, at least in saliva, accounted for 85% of its activity, the remanider being due to igg. antibody in secretions limited, but did not prevent, reinfection of the ... | 1976 | 182586 |
| variant infectious bronchitis virus isolated from indiana chickens. | infectious bronchitis virus (ibv) associated with a catarrhal tracheitis, sudden decline in egg production, and reduced shell quality was isolated from an indiana white leghorn breeder flock. it was found to be serologically different from massachusetts, connecticut, iowa 97, iowa 609, florida, arkansas 99, jmk, holte, gray and se 17 ibv serotypes. two different massachusetts vaccine strains protected chickens from respiratory signs but not against virus infection using the isolant for challenge ... | 1976 | 181740 |
| comparative ultrastructural studies on endemic (balkan) nephropathy and chicken embryo nephritis caused by infectious bronchitis virus. i. endemic (balkan) nephropathy. | | 1977 | 196485 |
| comparative ultrastructural studies on endemic (balkan) nephropathy and chicken embryo nephritis caused by infectious bronchitis virus. ii. chick embryo nephritis. | | 1977 | 196486 |
| genome of infectious bronchitis virus. | techniques are described for the growth and rapid purification of the avian coronavirus infectious bronchitis virus (ibv). purified ibv has a sedimentation coefficient of 320s and a buoyant density of 1.22 g/ml in sucrose-deuterium oxide equilibrium gradients. ibv rna extracted by proteinase k in the presence of sodium dodecyl sulfate and further purified by phenol extraction and gradient centrifugation is single stranded and has a sedimentation coefficient of 64s, as determined by isokinetic gr ... | 1977 | 198590 |
| strains of infectious bronchitis virus on the delmarva peninsula and in arkansas. | the constant-virus variable-serum neutralization test in chicken tracheal cultures was used to serotype infectious bronchitis virus (ibv) isolants from the delmarva peninsula and arkansas. of 106 isolants obtained from delmarva in 1971-1974, 93 were found to be the jmk strain, 5 massachusetts (mass), 5 connecticut (conn), 2 a new strain designated maryland (md) 27, and 1 a new strain designated md 31. of 26 isolants obtained from arkansas between october, 1971, and february, 1973, 17 were arkans ... | 1976 | 180960 |
| [sensitivity of japanese quail, embryos and embryonal tissue culture to infection with several avian viruses]. | the sensitivity of the biological system japanese quail-embryo-quail fibroblast cultures to some common fowl viruses (newcastle disease virus, infectious laryngotracheitis and infectious bronchitis viruses) was studied. japanese quails, their embryos and embryo cell cultures were found to be sensitive to newcastle disease virus infection. the virus reproduction was accompanied by death of embryos and destruction of cell culture. japanese quails are sensitive to infectious laryngotracheitis virus ... | 1977 | 198966 |
| growth kinetic studies of avian infectious bronchitis virus in tracheal organ cultures. | an egg-adapted vaccine strain (h120) and an organ culture-passaged field strain (hv-10) of avian infectious bronchitis (aib) virus were propagated in tracheal organ cultures and their growth kinetics examined using nine-day-old embryonated fowl eggs and chick tracheal explants for virus assay. when the h120 strain was assayed in embryonated eggs, titres were approximately log10 2-0 id50 (50 per cent infectious dose) per ml higher than when assays were performed in tracheal explants. the hv-10 st ... | 1976 | 180581 |
| the use of chicken tracheal organ cultures for the isolation and assay of avian infectious bronchitis virus. | a study has been made of the use of chicken tracheal organ cultures for the isolation and assay of avian infectious bronchitis (aib) virus from both naturally and experimentally infected chickens. six strains of aib virus were investigated, 3 of which had been isolated from natural outbreaks of disease. two of the virus isolations from the outbreaks of aib were made directly into tracheal organ cultures without passage in embryonated eggs. organ cultures prepared from 20-day-old embryos were use ... | 1976 | 176965 |
| [studies on the serological differentiation of field virus isolates and the protective action of vaccines in infectious bronchitis]. | | 1976 | 174542 |
| [economic effectiveness of specific preventive measures against infectious bronchitis of chickens]. | | 1977 | 201081 |
| small infective material coexistent with, but distinct from, avian infectious bronchitis virus. | | 1977 | 201199 |
| the polypeptide composition of avian infectious bronchitis virus. | avian infectious bronchitis virus grown in ovo was purified by differential centrifugation and isopycnic sedimentation in density gradients. the purified virus was analysed by sds polyacrylamide gel electrophoresis and found to comprise up to sixteen polypeptides, four of which were glycopeptides. bromelain treatment of the particles removed three polypeptides and two glycopeptides. | 1975 | 174524 |
| isolation of avian infectious bronchitis virus from experimentally infected chickens. | virus was recovered from the faeces of chickens infected at three or four weeks of age for more than 20 weeks after infection with commercial vaccines or with the t strain of avian infectious bronchitis virus (ibv). virus was not recovered from the trachea, liver, spleen, bursa or kidneys of t strain infected birds longer than 29 days after infection at which point ibv was recovered from the bursa of a single infected bird. in a subsequent experiment ibv was recovered from the caecal lymph nodes ... | 1977 | 203987 |
| comparative growth kinetic studies on avian infectious bronchitis virus in different systems. | | 1975 | 171289 |
| [the influence of temperature and incubation time on the propagation rate of the chicken infectious bronchitis virus in egg culture]. | | 1978 | 205206 |
| haemagglutination by avian infectious bronchitis virus-a coronavirus. | the haemagglutinating ability of three strains of ibv was investigated. it was shown that whereas strain beaudette had no detectable haemagglutinin, both connecticut and massachusetts agglutinated red cells of various species. the haemagglutinin of connecticut was detectable after sucrose gradient purification whereas that of massachusetts required both the purification step and incubation with the enzyme phospholipase c to reveal it. the agglutination could be inhibited by specific antisera. so ... | 1975 | 170378 |
| morphological changes of chicken tracheas and tracheal organ cultures infected with avian infectious bronchitis virus studied in scanning electron microscope. | chicken tracheas infected in vitro in organ culture and in vivo with avian infectious bronchitis virus (ibv) were studied by scanning electron microscopy. in in vitro infection in organ culture the columnar epithelial cells lining the tracheal ring lost their cilia and rounded up in 48 hr. there were numerous elevations and holes on the infected cell surface. subsequently the cells sloughed off. in in vivo infection the tracheal epithelial cells lost their cilia in 4 days. these cells without ci ... | 1975 | 169800 |
| typing field isolates of infectious bronchitis by the plaque-reduction test. | a technique is described for typing field isolates of infectious bronchitis virus by plaque-reduction assay of the serum antibody response of chickens experimentally infected with such isolates. also reported are use of the technique with field isolates and a comparison of results obtained in plaque-reduction assay and in tracheal-ring organ-culture assay. | 1978 | 206255 |
| serological responses of broiler-type chickens, with and without newcastle disease and infectious bronchitis vaccine, to experimental infection with mycoplasma synoviae by foot pad, air sac and aerosol. | serum plate (sp) and tube agglutination (ta) reactions and geometric mean mycoplasma synoviae (ms.) hemagglutination-inhibition (hi) titers were determined on chickens infected at 21 days of age with ms. by foot pad, air sac and aerosol. one-half had been given newcastle disease (nd) and infectious bronchitis (ib) vaccine in the water at 20 days of age, and the other half had not been vaccinated with nd and ib vaccine. blood was taken at 3, 4, 6 and 8 weeks after ms. infection. geometric mean hi ... | 1975 | 168564 |
| a long-term study of the pathogenesis of infection of fowls with three strains of avian infectious bronchitis virus. | | 1978 | 206936 |
| unexpected isolation of a newcastle disease virus. | | 1977 | 207254 |
| unexpected isolation of a newcastle disease virus. | | 1977 | 207255 |
| effect of infectious bronchitis vaccination on the performance of live newcastle disease vaccine. | | 1975 | 166478 |
| in vitro cultivation of cells from the chorioallantoic membrane of chick embryos. | by treatment of chorioallantoic membranes from embryonated eggs with collagenase and hyaluronidase before the conventional application of trypsin cells could be grown in culture which supported growth of a large variety of myxoviruses, herpesviruses, avian reoviruses and the infectious bronchitis virus of chickens. the cultures could be used for sensitive plaque assays and neutralization tests. | 1975 | 165393 |
| some immunological aspects of a recent australian isolate of infectious bronchitis virus. | an infectious bronchitis virus, designated g48, isolated from birds during an outbreak of nephritis in a previously vaccinated broiler flock, overcame the resistance induced in birds vaccinated with 2 commercially available vaccines. birds vaccinated with the a isolate of infectious bronchitis resisted challenge with this new virus. cross neutralisation studies revealed that the new virus was serologically distinct from the 4 viruses tested. homologous antiserum to g48 did not neutralise the oth ... | 1976 | 62570 |
| avian infectious bronchitis vaccine: primordial or derived virus? | vaccine formulations of virulent, modified/attenuated, or inactivated mono- or multivalent types of chicken embryo-propagated avian infectious bronchitis virus (ibv) at different passage levels and administered by non-parenteral routes have been used for immunization of chickens against the disease. two doses of vaccines are generally used: 1) high level virus of lessened virulence, antigenicity and immunogenicity as "derived" from its parental virus via serial passage in and selective adaptatio ... | 1976 | 60263 |
| potential for polyvalent infectious bronchitis vaccines. | numerous antigenic types and subtypes of infectious bronchitis virus (ibv) have been isolated and characterized from field epornitics of infectious bronchitis (ib). thus obvious failures in obtaining the necessary protection from vaccination have been documented and they underscore the urgent need for vaccines which stimulate a broader spectrum of protection from heterologous ibv challenge than is presently obtained. if polyvalent ib vaccines are to be employed, assurance must be provided that v ... | 1975 | 47726 |
| vaccination immunity to selected diseases in chickens fed the androgen analog mibolerone. | chickens fed the androgen analog mibolerone during the first 7 weeks of life regress their bursa of fabricius but can be properly immunized by vaccination against avian pathogens of major economic importance such as newcastle disease virus, infectious laryngotracheitis virus, avian encephalomyelitis virus, infectious bronchitis virus, fowl pox virus, marek's disease virus, and pasteurella multocida, the pathogen causing fowl cholera. these findings on immunocompetence to infectious agents are im ... | 1978 | 209430 |
| avian infectious bronchitis: characteristics of the virus and antigenic types. | | 1975 | 47725 |
| [measures against infectious bronchitis in chickens]. | | 1978 | 211704 |
| report of iabs committee on avian product standardization. | the international association of biological standardization (iabs) organized an international symposium in august 1973 on the "requirements for poultry virus vaccines" at lyon (france). the proceedings of this symposium were subsequently published as "developments in biological standardization", volume 25. at the conclusion of this symposium, it was resolved that an avian biological products standardization committee should be established, this committee including four subcommittees, each under ... | 1978 | 38158 |
| differentiation of avian infectious bronchitis virus isolates by thermal sensitivity. | six isolates of avian infectious bronchitis virus (ibv) at different passage levels in the chicken embryo were tested for sensitivity at 56 c, with the following results: 1) isolates differed in thermal sensitivity; 2) virus was inactivated in a first-order exponential-kinetics 2-component fashion indicative of a heterogeneous population with a preponderance, 98% or more, of thermal-sensitive (s) virions over thermal-resistant (r) virons; 3) r virions 2-component populations were inactivated; 4) ... | 1978 | 212002 |
| the genomes of three coronaviruses. | | 1978 | 212316 |
| the resistance to reinfection of tracheal organ cultures from chickens previously infected with avian infections bronchitis virus. | lower titres of avian infectious bronchitis (aib) virus were found following the infection of tracheal organ cultures prepared from chickens that had been given aib virus intranasally six weeks previously than were found following the infection of organ cultures prepared from untreated or from passively-immune chickens. no infectious virus was found in the tracheal organ cultures at the time they were prepared. | 1978 | 212798 |
| effect of ph on the growth and cytopathogenicity of avian infectious bronchitis virus in chick kidney cells. | the growth of avian infectious bronchitis virus (ibv) in chick kidney cells at different ph values in the range 6.0-9.0 demonstrated that although the virus was released at a much faster rate at the higher ph values the titre tended to drop more quickly. at the acid ph values the virus was released more slowly but reached a maximum titre similar to that at the higher ph values and showed only minimum reduction in infectivity up to 49 hours post inoculation. the stability of virus in tissue cultu ... | 1975 | 2145 |
| gumboro disease and infectious bronchitis. | | 1977 | 190759 |
| morphogenesis of avian infectious bronchitis virus in primary chick kidney cells. | primary chick kidney cells were infected with avian infectious bronchitis virus (ibv) and examined by electron microscopy. virus particles entered the cells by viropexis and distinction could be made between engulfment by cell processes (phagocytosis) and entry by micropinocytosis in coated transport vesicles. virus maturation occurred by budding into either the cisternae of the endoplasmic reticulum or cytoplasmic vacuoles, and evidence was obtained to suggest that the viral surface projections ... | 1976 | 187144 |
| [vaccination of chicks against infectious bronchitis and newcastle disease]. | | 1978 | 216138 |
| effect of infectious bursal disease on the response of chickens to mycoplasma synoviae, newcastle disease virus, and infectious bronchitis virus. | at 35 days of age, chickens which as 1-day-old chicks were inoculated with the infectious bursal disease virus (ibdv) had significantly lower antibody titers against mycoplasma synoviae, newcastle disease virus, and infectious bronchitis virus than did those never inoculated with ibdv. the ibdv also had a marked effect on the development of air-sac lesions. birds infected with ibdv that were later inoculated with m synoviae (day 14), newcastle disease virus (days 14 and 28) experienced an increa ... | 1977 | 190926 |
| the characterisation of the virion rna of avian infectious bronchitis virus. | | 1977 | 193735 |
| [infectious bronchitis and colibacteriosis in chickens]. | | 1976 | 194387 |
| immunosuppressive effects of the infectious bursal agent and relationships to other poultry diseases. | | 1976 | 220631 |
| [infectious bronchitis and pullorum disease in chickens]. | | 1979 | 222043 |
| [infectious bronchitis of chickens in azerbaijan]. | | 1976 | 194388 |
| studies on avian infectious bronchitis virus (ibv). ii. propagation of ibv in several cultured cells. | the growth of ten strains of avian infectious bronchitis virus (ibv) in several cultured cells was examined. the cultured cells used were chick kidney (ck), chick embryo (ce), hela and bhk-21 cells. the results obtained can be summarized as follows. 1. all the strains showed similar growth curves in ck cells. progeny viruses appeared in the culture medium 4 to 6 hours after inoculation and peak virus titers of 10(6.5)--10(8.5) tcid50 per 0.1 ml were obtained after 36 hours. a cytopathogenic effe ... | 1979 | 226034 |
| influence of environment on airsacculitis: effects of relative humidity and air temperature on broilers infected with mycoplasma synoviae and infectious bronchitis. | mycoplasma synoviae (ms) obtained from broiler chickens condemned for airsacculitis was used to determine the influence of air temperature and relative humidity on the severity of airsacculitis produced experimentally. infectious bronchitis virus was administered to 3-week-old broilers 5 days before aerosol exposure to ms broth cultures, producing extensive airsacculitis within 21-day study periods. high (31-32 c), medium (19-24 c), and low (7-10 c) air temperatures were studied in conjection wi ... | 1977 | 194567 |
| taxonomic studies on strains of avian infectious bronchitis virus using neutralisation tests in tracheal organ cultures. | the antigenic relationships of 24 strains of avian infectious bronchitis virus (ibv) were investigated by serum neutralisation tests performed in chick embryo tracheal organ cultures. the serum dilution that neutralised 100 median ciliostatic doses (cd50) of virus was estimated from the linear relationship between varying concentrations of each virus strain and the neutralisation titre of homologous antiserum; this dilution defined 1 antibody unit. antisera diluted to contain 20 antibody units w ... | 1979 | 227344 |
| [respiratory diseases in poultry caused by viruses--occurrence and diagnosis (author's transl)]. | the highly intensive conditions, that economic necessity has forced upon the poultry industry, have resulted in strongly changed environmental conditions and management which combined with the use of a constantly increasing number of live vaccines has highly complicated clearing up the etiology in diseased flocks. this is true not least as far as respiratory diseases concerns, which thereby often run an atypical course. a review, however, not complete, is given of the occurrence and diagnostic p ... | 1977 | 198739 |
| comparison of duration of immunity in chickens infected with a live infectious bronchitis vaccine by three different routes. | three groups of chicks were vaccinated by aerosol, intra-ocular and drinking water routes with a live infectious bronchitis (ib) vaccine. at one, two, six, 15 and 32 weeks after vaccination five birds from each group were sampled for testing for ib haemagglutination-inhibiting (hi) antibodies and challenged. assessment of susceptibility to infection was measured by recovery of virus from individual tracheas and from kidney and gonad pools four days after challenge. virus was isolated from all ki ... | 1979 | 229532 |
| studies on the structure of a coronavirus-avian infectious bronchitis virus. | when avian infectious bronchitis virus (ibv) is fixed in formaldehyde, negative stain is able to penetrate the particle and an internal component is visualized. this component is seen as a tongue or flask shaped structure attached at one point to the outer virus membrane. a model yielding transmission patterns similar to the virus has been made. gradient centrifugation studies on ibv reveal that the rnp is associated with the internal sac. | 1977 | 199696 |
| ph stability studies with avian infectious bronchitis virus (coronavirus) strains. | a comparison of 17 infectious bronchitis virus strains, using the same test procedure and assay system, demonstrated that stability at an acid ph is a variable characteristic of the avian coronaviruses. | 1975 | 234539 |
| biological properties of avian coronavirus rna. | rna with a sedimentation coefficient of 64s was isolated from infectious bronchitis virus, an avian coronavirus. the sna contained a polyadenylic acid tract and was found to be infectious. | 1977 | 199697 |
| the polypeptide composition of avain infectious bronchitis virus particles. | egg grown avian infectious bronchitis virus (ibv) centrifuged on sucrose density gradients was found to consist of a major virus peak of density 1.17 to 1.18 g/cm(3). three different ibv strains were examined and no morphological differences were detected between virus particles of different densities or from different strains. the polypeptides of the different density virus particles from the three ibv strains were analysed on polyacrylamide gels. in all cases 7 polypeptides were observed, alth ... | 1977 | 200202 |
| polypeptides of the surface projections and the ribonucleoprotein of avian infectious bronchitis virus. | purified avian infectious bronchitis virus was digested with bromelain (0.7 mg/ml), and the surface projections were removed. polyacrylamide gel electrophoresis of the polypeptides from these bromelain-treated particles showed that vp1, vp2, and vp5 were missing from the seven polypeptides. vp1 to vp7, that were present in untreated virus preparations. milder bromelain treatment (0.07 mg/ml) left visible surface projections and polypeptides comprising vp1 and vp2 intact, but removed vp5. thus, t ... | 1977 | 201778 |
| the effect of ascorbic acid on infection chick-embryo ciliated tracheal organ cultures by coronavirus. | chick embryo tracheal organ cultures showed increased resistance to infection by a coronavirus after exposure to ascorbate, while chick respiratory epithelium and allantois-on-shell preparations showed no increase in resistance to infection by an influenza virus or a paramyxovirus. | 1978 | 205194 |
| the purification and polypeptide composition of avian infectious bronchitis virus. | purification of egg-grown infectious bronchitis virus (ibv) by sucrose density gradient centrifugation alone, or sucrose density gradient centrifugation plus ph 8.0 treatment, concanavalin a precipitation or metrizamide density gradient centrifugation, failed to produce any differences in the virus polypeptide pattern following polyacrylamide gel electrophoresis in the presence of sds(sds-page). sds-page of purified ibv on 7.5% acrylamide gels separated 16 polypeptides which were detectable by s ... | 1977 | 205761 |
| stability of live, freeze-dried virus vaccines. | stability of live, freeze-dried vaccines is a major factor for successful vaccinations. vaccines may be stored at -20 degrees c or less for long periods without loss of activity and this storage does not affect stability during subsequent storage. storage in the refrigerator for long periods is harmless for certain very stable vaccines such as influenza, rubella, ndv, marek's. other vaccines, such as ibv, show a significant loss in titer after 2 years. the routine use of an accelerated stability ... | 1976 | 1030427 |
| immune response to infectious bronchitis virus. | | 1975 | 1092219 |
| the ribonucleic acid of infectious bronchitis virus. | analysis of the nucleic acid of infectious bronchitis virus by sds polyacrylamide gel electrophoresis revealed an rna of molecular weight 9.0 times 10-6 daltons. the rna was shown to have a sedimentation coefficient of 50. | 1975 | 1119945 |
| growth comparisons of avian infectious bronchitis virus strains in organ cultures of chicken tissues. | six strains of avian infectious bronchitis virus (ibv) were used to inoculate explants of a range of 15 chicken tissues and virus growth kinetics observed over a period of 96 hours thereafter. similar patterns of virus production were given by all 6 strains from explants of any particular tissue such as the nasal turbinates, trachea, lung, air sacs and oviduct. nevertheless, significant differences in behaviour between strains were noted for different tissues and in the efficiency with which cer ... | 1978 | 206229 |
| response to several avian respiratory viruses as affected by infectious bursal disease virus. | after being inoculated with the infectious bursal disease virus (ibdv) at one day of age, specific-pathogen-free chickens were inoculated with either newcastle disease virus (ndv), infectious bronchitis virus (ibv), or infectious laryngotracheitis virus (iltv). their immunity was challenged 2-3 weeks later with homologous virus, and antibody titers were determined for iltv and ibv. several studies were made to determine the effects of ibdv on the development of persistent or chronic virus infect ... | 1978 | 206256 |
| ribonucleoprotein-like structures from coronavirus particles. | the structure of the ribonucleoprotein (rnp) complex of three coronaviruses was investigated. a single-stranded helix of diam. 14 to 16 nm and up to 320 nm in length was released from disrupted particles of human coronavirus strain 229e and mouse hepatitis virus strain 3 after incubation in mild conditions. the helical complexes appeared to be composed of globular subunits with long axes of 5 to 7 nm surrounding a hollow core of diam. 3 to 4 nm. the complexes were shown to be sensitive to both p ... | 1978 | 207820 |
| studies on avian infectious bronchitis virus in new zealand. i. serotypes. | | 1977 | 208028 |
| identification of two new polypeptides encoded by mrna5 of the coronavirus infectious bronchitis virus. | the second smallest subgenomic messenger rna, mrna5, of the coronavirus infectious bronchitis virus includes in its "5' unique region" two separate open reading frames (5a and 5b), whose coding function has not so far been established, and thus it may represent a dicistronic messenger rna. we report here that two polypeptides with the sizes expected for the 5a and 5b products can be synthesised by in vitro translation of a single artificial mrna containing both the 5a and 5b orfs. to establish w ... | 1992 | 1309280 |
| coronavirus ibv-induced membrane fusion occurs at near-neutral ph. | the lysosomotropic agent nh4cl caused a reduction of 80-95% in the number of chick kidney (ck) cells and vero cells infected by infectious bronchitis virus (ibv) strain beaudette, as determined by immunofluorescence at the end of the first replication cycle. inhibition only occurred when nh4cl was present during the first 2 h after infection. syncytium formation was studied during replication of ibv-beaudette in vero cells. some cell-cell fusion occurred at ph 7.0 and ph 6.5 but it was optimal a ... | 1992 | 1309994 |
| studies on avian infectious bronchitis virus in new zealand. ii. properties of four serotypes at a low and a high passage level. | | 1977 | 208029 |
| rapid detection and identification of avian infectious bronchitis virus. | a rapid and sensitive method for the detection and unambiguous typing of infectious bronchitis virus (ibv) is described. rna was isolated from ibv-infected allantoic fluid and was transcribed into cdna. this cdna was amplified by the polymerase chain reaction. the polymerase chain reaction products were subsequently analyzed on an agarose gel. the presence of ibv-specific rna in the allantoic fluid then allowed the amplification of a 438-bp dna fragment from the nucleocapsid (n) gene. for the ty ... | 1992 | 1310335 |
| studies on avian infectious bronchitis virus in new zealand. iii. efficacy of an attenuated live infectious bronchitis vaccine of new zealand origin in broiler birds. | | 1977 | 208030 |
| immune electron microscopy of avian infectious bronchitis virus serotypes. | an immune electron microscopy agglutination technique in which emphasis is placed upon the importance of antigen-antibody equivalence has been developed as a possible method for the serotyping of avian infectious bronchitis viruses. the connecticut and massachusetts 41 serotypes were used as a model system. stock virus concentrations were standardized by physical particle counts of virions sedimented directly onto electron microscope specimen grids. suspensions containing approximately 150 virio ... | 1978 | 209056 |
| vaccination against infectious bronchitis and the immunosuppressive effects of infectious bursal disease. | an immunosuppressive effect was demonstrated in chickens which were infected with infectious bursal disease virus (ibdv) early in life and prior to or shortly after vaccination with infectious bronchitis virus (ibv). this effect was evident by an increased susceptibility to respiratory tract infection with ibv and reduced virus-serum neutralizing antibody levels. chickens which were hatched from dams susceptible to infectious bursal disease (ibd) were less responsive to ibv immunization attempts ... | 1978 | 209433 |
| interaction of aflatoxin with infectious bursal disease virus infection in young chickens. | young white leghorn chickens fed 2.5 microgram of aflatoxin (afl) per g of diet from hatching until 4 weeks old and infected with infectious bursal disease virus (ibdv) at 3 weeks old had significantly higher mortality and more severely depressed body weights than chicks with aflatoxicosis or ibd alone. afl-ibdv chicks also had more extensive gross and microscopic changes characteristic of ibd than did ibdv-chicks. none of the treatments significantly reduced antibody responses to newcastle dise ... | 1978 | 212001 |