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Biomedical subjects

C S Eidson

Publications and source records attributed to C S Eidson.

81 records · Page 5Linked to original sources
PubMedDate not supplied

Airsacculitis induced in broilers with a combination of Mycoplasma gallinarum and respiratory viruses.

Mycoplasma gallinarum was isolated from tracheas and air-sac lesions from broilers in flocks having higher than normal condemnations due to airsacculitis. A representative M. gallinarum isolant, given by aerosol or by air-sac inoculation, produced air-sac lesions in young chickens when given in combination with a vaccine combining Newcastle disease and infectious bronchitis or with a field strain of infectious bronchitis virus.

Agglutination Tests↗
PubMedDate not supplied

Studies on interferon induction by infectious bursal disease virus (IBDV). II. Interferon production in White Leghorn chickens infected with an attenuated or pathogenic isolant of IBDV.

Infectious bursal disease virus (IBDV) isolants that differed in virulence for chickens, were compared as to: 1) induction of interferon in serum and tissues; and 2) stimulation of IBDV serum antibody. Specific-pathogen-free chickens were infected at one day and four weeks of age by the subcutaneous and intranasal routes of inoculation. The pathogenic isolant induced a more generalized interferon response than the attenuated isolant, independent of age or route of inoculation. Pathogenic IBDV stimulated interferon in serum, kidney, lung, thymus, spleen, and bursa of Fabricius. The attenuated virus induced interferon only in the bursa. The serum interferon response was greater following inoculation with pathogenic IBDV than with the attenuated virus. Serum interferon titers peaked 2-3 1/2 days after inoculation. The pathogenic and attenuated viruses stimulated similar IBDV-neutralizing antibody responses, which occurred after peak serum interferon activity.

Animals↗
PubMedDate not supplied

Immunization of broiler breeder chickens against Newcastle disease with an oil-emulsion vaccine.

Antibody response was rapid and high in broiler breeder chickens receiving 1 or 2 vaccinations with oil-emulsion vaccine against Newcastle disease at 23 or at 23 and 26 weeks old. The antibody titers remained high during the 41-week experimental period. At 64 weeks old, about 41 weeks after vaccination, the geometric mean hemagglutination-inhibition antibody titer was 67 from the single vaccination, and 103 from the double vaccination. The immune response to live-virus vaccine given at 2, 9, 20, 30, 42, or 54 weeks of age via the drinking water was high, but uniformity was lacking in the antibody response in the breeders and maternal antibody response in the progeny. Maternal antibody levels in one-day-old chicks were related to the titers of antibody in the dams. Maternal antibody titers of chicks originated from breeder flocks that were vaccinated with the oil-emulsion vaccine remained high for all hatches.

Administration, Oral↗
PubMedDate not supplied

A comparison of immune responses of broiler chickens to different methods of vaccination against Newcastle disease.

One-day-old broiler chicks from 4 groups of broiler breeder chickens were immunized by different methods of vaccination: 1) aerosol; 2) intratracheal; 3) drinking water; or 4) unvaccinated. The breeder flock from which the chicks were derived was vaccinated by one of the following methods: 1) a single injection of an oil-emulsion Newcastle disease virus (NDV) vaccine; 2) two vaccinations with oil-emulsion NDV vaccine; 3) vaccination with a live NDV vaccine; and 4) unvaccinated controls. Aerosol vaccination induced higher serologic responses than water and intratracheal vaccination, as well as giving the highest levels of protection against challenge. Mortality ranged from 20% to 66% in all eight groups of birds vaccinated intratracheally and challenged at 6 weeks of age. Results of challenge tests, in agreement with results of HI tests, further demonstrated that intratracheal vaccination at one day of age does not elicit a satisfactory immune response in birds with a maternal antibody titer of 15 or higher.

Administration, Oral↗
PubMedDate not supplied

Viral tissue tropisms and interferon production in white leghorn chickens infected with two avian reovirus strains.

Inoculation of 6-day-old and 4-week-old chickens with pathogenic or attenuated avian reovirus resulted in an inapparent infection. The virus had a greater tissue distribution and persisted longer in tissues of 6-day-old chickens. Interferon was detected in only the serum and lung of infected chickens and appeared to be related to route of inoculation. Titers of interferon were greater and appeared sooner in the tissues of older chickens. Reovirus-neutralizing antibody was not detected in the serum of chickens of either age 120 days postinfection.

Age Factors↗
PubMedDate not supplied

Studies on interferon induction and interferon sensitivity of avian reoviruses.

Four strains of avian reovirus were ineffective inducers of interferon (IFN) in chicken kidney (CK) cell cultures. All strains were similar in single-cycle replication curves. At multiplicities of infection between 0.20 and 10 plaque-forming units per cell, IFN was not induced in CK cells. Reovirus did not produce an IFN blocker in CK cells. Attenuated reovirus did induce IFN in aged chicken embryo fibroblast (CEF) cell cultures. By priming cells with a low dose of IFN before infection with reovirus, IFN formation by CEF could be enhanced. Ultraviolet-inactivated avian reovirus was an effective inducer of IFN in both CK and CEK cell cultures. The sensitivity of avian reoviruses (Fahey-Crawley, Reo-25, S-1133, Reo-V) to chicken interferon (Ch-IFN) was studied by the plaque-reduction method. Avian reoviruses were less sensitive to Ch-IFN than was vesicular stomatitis virus or Semliki Forest virus and appeared to be as resistant to IFN as was Newcastle disease virus.

Animals↗