Allergenic activity and biochemical analysis of three soluble antigen preparations from Brucella abortus strain 45/20.
Three Brucella abortus strain 45/20 antigen preparations were compared with regard to their chemical composition and allergenic potential. A popular method of extracting soluble antigens from whole cells with hypertonic saline solution and ethanol precipitation was compared with the method of trichloroacetic acid (TCA) or ammonium sulfate (AS) precipitation of antigens released into solution by ultrasonic cell disruption. Biochemical analysis of the preparations revealed that TCA and AS precipitates had considerably more protein and DNA and less carbohydrates and RNA than did the saline-ethanol extracts. Strain 19-vaccinated cattle were simultaneously skin tested with the three antigen preparations which had been standardized to an equal protein content. Significant (P less than 0.01) delayed hypersensitivity reactions were observed in response to all three antigen preparations. However, TCA-prepared allergens were more active in eliciting delayed hypersensitivity (P less tha 0.05) than were the two other allergens. Increased agglutinating antibodies were not observed in response to the skin-test reagents.
D000485:Allergens / Q000276:immunology* / Q000302:isolation & purification; D000818:Animals; D000942:Antigens, Bacterial / Q000276:immunology* / Q000302:isolation & purification; D002003:Brucella abortus / Q000276:immunology*; D002417:Cattle / Q000276:immunology; D012882:Skin Tests
D000485:Allergens; D000942:Antigens, Bacterial