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Biomedical subjects

R B Davis

Publications and source records attributed to R B Davis.

At least 181 records · Page 10Linked to original sources

Fowl cholera immunization in turkeys. I. Efficacy of various cell fractions of Pasteurella multocida as vaccines.

Cell fractions of Pastuerella multocida (P-1059) were tested as vaccines against fowl cholera in turkeys. These fractions were culture filtrate, cell wall, and cytoplasm. A second culture filtrate preparation made from cells grown on blood-agar rather than the standard medium was also tested along with a "combination" preparation made by recombination of the cell fractions. Each preparation was tested in three vehicles: saline, alum (0.5%), and Freund Incomplete Adjuvant (50%). The turkeys vaccinated with these preparations were challenged by exposure to an experimental epornitic of fowl cholera. The combination fraction appeared to be the most promising vaccine when compared to the protective action of the commercial bacterin included in the test as a positive control.

Agar↗

Fowl cholera immunization in turkeys. II. Use of experimental epornitic method to study vaccine efficacy in flocks of turkeys.

Groups of turkeys were challenged with Pasteurella multocida (P-1059) by the contact method. In this method, turkeys are artificially infected by the intramuscular injection of P. multocida organisms and are then introduced into the test group. The death patterns resulting from this contact method of challenge are either normally distributed or skewed to the right.

Animals↗

Fowl cholera immunization in turkeys. 3. Significance of market quality in the evaluation of fowl cholera vaccines.

Turkeys vaccinated with various experimental vaccines and a commerical bacterin for fowl cholera and surviving an artificially induced epornitic were killed, and their carcasses were examined for wholesomeness. It was evident that, if the "fitness for human consumption" judgement was considered in addition to mortality, efficacy ratings of the various vaccines changed. This suggests that the "fitness for human consumption" factor be considered in future evaluation of biologicals for use in meat-producing birds.

Agar↗

Immunization of mice with components of Pasteurella multocida.

Log-phase cells of Pasteurella multocida strain P-1059 were used to prepare isolated culture filtrate, cell wall, and cytoplasmic components. Culture filtrate was further separated by column chromatography. A portion of cytoplasm and culture filtrate was conjugated to ferritin by means of metaxylylene diisocyanate. Cell walls induced more protection in mice than the conjugated or unconjugated cytoplasm or culture filtrate. The cell walls caused edema and erythema when given intradermally in rabbits, whereas cytoplasm and culture filtrate produced dermal necrosis. The first of four chromatographically separated fractions of culture filtrate was possibly more immunogenic in mice than cell walls. This fraction was less reactive intradermally in rabbits than cell walls but more reactive than the other fractions.

Acrylates↗

Antibiotic treatment of ulcerative enteritis of bobwhite quail.

Penicillin-streptomycin, bacitracin methylene disalicylate, zinc bacitracinm, soluble bacitracin methylene disalicylate, streptomycin (25%) and spectinomycin were used as prophylactic and therapeutic treatments for ulcerative enteritis in bobwhite quail (Colinus virginianus). Penicillin-streptomycin was the most effective prophylactic and streptomycin (25%) was the most effective therapeutic agent.

Animals↗