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Biomedical subjects

J K Cook

Publications and source records attributed to J K Cook.

At least 19 recordsLinked to original sources
PubMed1992

Characterisation of an infectious bronchitis virus isolated from vaccinated broiler breeder flocks.

Four apparently serologically closely related isolates of infectious bronchitis virus were obtained from two flocks of vaccinated broiler breeders, one mile apart, which were experiencing increased mortality and decreases in egg production. The isolates were serologically distinct from isolates previously described and capable of causing characteristic infectious bronchitis-like respiratory infection in young chicks. In one experiment, the H120 vaccine strain of the virus did not protect the trachea against challenge with the new isolates 21 days later.

Animals↗
PubMed1991

A recombinant fowlpox virus that expresses the VP2 antigen of infectious bursal disease virus induces protection against mortality caused by the virus.

The coding sequences of VP2 from a virulent strain, 52/70, of infectious bursal disease virus (IBDV) were excised from a cDNA clone and inserted into a fowlpox plasmid insertion vector. The resulting plasmid, pIBD 1, was used to construct a recombinant fowlpox virus, fpIBD 1, which expressed VP 2 as a beta-galactosidase fusion protein. Chickens vaccinated with fpIBD 1 at 1 and 14 days of age, were challenged at 28 days with either IBDV strain 52/70 or the highly virulent strain CS 89. These chickens were protected against mortality, but not against damage to the bursa of Fabricius. The protection achieved by the use of fpIBD 1 shows that VP 2 is a host protective antigen.

Amino Acid Sequence↗
PubMed1991

Effect of in ovo bursectomy on the course of an infectious bronchitis virus infection in line C White Leghorn chickens.

White Leghorn line C chicks were surgically bursectomised (Bx) in ovo to eliminate antibody production. After inoculation with infectious bronchitis virus (IBV) at 14 days after hatching, Bx chicks experienced a more severe and longer lasting infection than intact chicks. The severity and duration of clinical infection in the Bx chicks resembled that previously observed in the highly susceptible line 15I chicks, however no increase in mortality was observed, in contrast to the high levels of mortality recorded in IBV-inoculated line 15I chicks. After secondary challenge the degree of damage to the ciliated epithelium of the trachea was greater in the Bx chicks than in the intact chicks. The results indicate that, although antibodies play an important role in recovery from IBV infection, other immunological factor(s) may also be involved.

Animals↗
PubMed1990

A method for the rapid purification of serum IgM for the diagnosis of recent viral infections of chickens.

The rapid purification of chicken IgM from serum was achieved by affinity chromatography. IgM immunoadsorbent gels were prepared using monoclonal antibodies specific to chicken IgM. Five different eluting agents were compared for the dissociation of the adsorbed IgM; the most convenient for routine purposes was 2 M NaCl, Tris-HCl, EDTA (NTE), as this enabled direct assay of eluents by ELISA without requiring the intermediate step of dialysis, which the other eluting agents did. Eluents prepared from sera obtained from infectious bronchitis virus (IBV) and infectious laryngotracheitis (ILTV)-infected chickens, together with samples of the same serum fractionated by gel chromatography, were tested by ELISA for virus-specific antibodies and to confirm the identity of the antibody class. In the case of both IBV and ILTV, similar results were obtained using immunoaffinity and gel chromatography. IBV-specific IgM, as determined by both methods in the ELISA, reached its highest concentration at the 8th day after inoculation and was virtually absent by the 24th day, whilst the highest concentration of ILT-specific IgM was detected at 6 days and no or little IgM was present at 16 days after inoculation. Purification of serum IgM by affinity chromatography followed by ELISA was considered suitable for routine serological diagnosis of IB and ILT, since the time required to complete the assay (3 hours) was considerably less than that for gel chromatography and many samples could be assayed simultaneously.

Animals↗
PubMed1989

Genetic differences in susceptibility to a mixture of avian infectious bronchitis virus and Escherichia coli.

Two-week-old chickens of 9 inbred and partially inbred lines of chickens were challenged intranasally with a mixed infection consisting of a pool of virulent strains of infectious bronchitis virus and a pool of pathogenic strains of Escherichia coli. 2. Wide differences in mortality were observed in the different lines, ranging from 3% in a Brown Leghorn line to 87% in White Leghorn line 7(2). 3. Experiments involving challenge with E. coli alone or virus alone suggested that this variation reflected resistance to the virus rather than to E. coli. 4. Reciprocal F1 matings suggested these differences in mortality were not attributable to maternal effects and indicated that the inheritance of resistance was fully dominant. 5. The pattern of mortality in F2 and backcross progeny of matings was compatible with the inheritance of a dominant autosomal resistance gene and showed no evidence of association with the major histocompatibility complex.

Animals↗
PubMed1988

Antibiotic resistance of Escherichia coli strains isolated from chickens with colisepticaemia in Morocco.

Sixty-two strains of Escherichia coli were isolated in 58 farms from broiler chickens showing respiratory signs and lesions characteristic of avian colibacillosis. Serological examination of these strains showed that the types 078, 01 and 02 (for the somatic antigen) and K1 (for the capsular antigen) were the most frequently found. Newcastle disease virus was also isolated in two cases. All the strains of E. coli isolated were sensitive to colistin, flumequine and gentamicin. A few strains were resistant to neomycin, nalidixic acid and trimethoprim. The frequency of strains resistant to nitrofurans, sulfonamides, chloramphenicol, spectinomycin and ampicillin was intermediate. Most strains were resistant to tetracycline. Multiple resistance was common.

Animals↗
PubMed1987

Expression of the infectious bronchitis virus spike protein by recombinant vaccinia virus and induction of neutralizing antibodies in vaccinated mice.

A cDNA clone of the infectious bronchitis virus (IBV) spike protein gene has been recombined into vaccinia virus. Cells infected with the recombinant virus synthesized IBV spike antigen which was recognized by antibody raised against purified spike protein. Immunofluorescence showed that the IBV spike antigen was transported to the infected cell surface membrane and immunoprecipitation showed the presence of the glycosylated 180K mol. wt. polypeptide precursor of the two spike subunits S1 and S2 that comigrated with this antigen from IBV-infected cells. Vaccinated mice produced antibody that recognized the IBV spike antigen by ELISA and which neutralized IBV infectivity as shown by ciliostasis tests on tracheal organ cultures.

Antibody Formation↗
PubMed1986

Infectious bronchitis immunity: its study in chickens experimentally infected with mixtures of infectious bronchitis virus and Escherichia coli.

The live infectious bronchitis (IB) vaccine, H120, protected chickens against intranasal challenge with a mixture of Escherichia coli strains (E. coli Pool) and IB virus (IBV) strains of the same (Massachusetts) serotype as H120; it usually also protected against challenge with the E. coli Pool and IBV strains of other serological types. When these challenge strains were themselves used as vaccines they usually protected against challenge with a mixture of the E. coli Pool and an IBV strain of the Massachusetts serotype (VF69-149) or an IBV strain not of the Massachusetts serotype (HVI-116). Poor protection, when observed, was most common in those experiments involving a minority of the IBV strains that had been incriminated in recent outbreaks of disease in vaccinated flocks of chickens. Much lower concentrations of IBV strain VF69-149 and E. coli O18 were found in the nose, trachea and spleen of H120-vaccinated chickens killed at different times after they were given a mixture of these organisms than were found in these sites in similarly challenged unvaccinated chickens. Some protection against challenge with IBV and the E. coli Pool was also observed in chickens vaccinated with an inactivated IBV strain; it was much less effective than that obtained following vaccination with the corresponding live IBV strain.

Administration, Intranasal↗
PubMed1985

The experimental infection of chickens with mixtures of infectious bronchitis virus and Escherichia coli.

By inoculating chickens intranasally with a collection of strains of infectious bronchitis virus (IBV) of the Massachusetts serotype and of Escherichia coli of different serotypes, a pool of viral and bacterial strains was selected which, on inoculation, consistently produced a highly lethal disease closely resembling the natural disease produced by these two organisms. The conditions for reproducing the experimental disease were not rigorous in that, within broad limits, the size of the viral and bacterial inocula were not important; neither were the times at which both organisms were administered in relation to each other. The breed or strain of chicken used was important and the resistance of chickens to fatal infection increased with age. When the E. coli strains of the pool were inoculated intranasally without the IBV component, the chickens remained well; bacteriological examination of chickens inoculated with one of the E. coli strains, O18, revealed little evidence of invasion of the tissues or even of persistence of the inoculated E. coli strain in the upper respiratory tract. A minority of the IBV strains examined were lethal for chickens when inoculated without E. coli but many of them only produced a substantial mortality when the E. coli were included in the inoculum; IBV strains in this latter category included the vaccine strains H52 and H120. High concentrations of IBV strain M41 and E. coli O18 persisted in the upper respiratory tract for a number of days after they had been inoculated together. Much lower concentrations of IBV M41 were found in the internal organs, such as the spleen; E. coli O18 was only found in these sites in some of the inoculated chickens. Coliform organisms proliferated in the upper respiratory tract of chickens inoculated with IBV alone; they were rarely found in their internal organs.

Animals↗
PubMed1983

The use of an enzyme-linked immunosorbent assay to detect IgG antibodies to serotype-specific and group-specific antigens of fowl adenovirus serotypes 2, 3 and 4.

A sensitive enzyme-linked immunosorbent assay (ELISA) has been developed which can detect serotype and group-specific antibodies (IgG) to fowl adenovirus serotypes 2, 3 and 4. The chickens produced principally type-specific antibodies after a single oral inoculation of virus which enabled that strain to be identified by the ELISA. However, inoculation of an heterologous serotype, although inducing strain-specific antibodies to itself, also induced high levels of antibody to the group-specific antigens. This masked the serotype-specific antibodies in the ELISA to the first serotype. The ELISA, which has similar sensitivity to the serum neutralisation test, could be used as a rapid, easily performed test to identify fowl adenovirus-specific antibodies.

Adenoviridae↗
PubMed1979

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 were then tested by neutralisation against 1.5--2.5 log10 CD50 of each strain. Clusters of both strains and antisera in turn were established by methods of numerical taxonomy using as measures of resemblance Euclidean distance and correlation coefficient, and by analysis by principal components. These analyses identified a group of 8 similar strains; neutralisation of the remaining 16 strains was slight. Similar results were obtained by classifying antisera, except that a further group of 3 antisera was demonstrated, each having a neutralising capacity for most strains. Implications for vaccine formulation are discussed.

Animals↗
PubMed1979

The susceptibility of chicken kidney and oviduct organ cultures to a vaccine strain of avian infectious bronchitis virus.

The minimal infectious dose of the H52 strain of infectious bronchitis virus for organ cultures of oviduct and kidney was compared in chickens of different ages. Organ cultures of oviduct were found to be highly susceptible to infection regardless of the age of chicken and no difference in susceptibility could be demonstrated between cultures of the magnum and uterus regions of the mature oviduct. Kidney organ cultures were less susceptible and resistance to infection increased significantly (P less than 0.001) with the age of the chicken from which cultures were prepared.

Age Factors↗
PubMed1978

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 certain tissues produced virus. It is suggested that the method has a potential value in determining the virulence of different strains of IBV by comparing their pathogenesis of chicken tissues in vitro.

Animals↗
PubMed1976

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 used since they were found to be somewhat more sensitive in virus assay than those derived from chickens of up to 31 days of age. Ciliostasis, which was used as the marker of infectivity, was complete by 3 days after inoculation with each strain of virus examined. Virus could be isolated from both respiratory and non-respiratory tissue in tracheal organ cultures and these cultures were found to be at least as sensitive as 9-day-old embryonated eggs in detecting AIB virus either in pathological material or in serial dilutions. When virus was assayed in both systems, the titres were very similar. It is considered, therefore, that chicken embryo tracheal organ cultures offer a reliable alternative system to embryonated eggs for studying AIB virus.

Animals↗