Abstract:
Capsular antigens of "Staphylococcus aureus" Smith and 2-8 strains were evaluated for immunogenicity in mice. Cultural conditions necessary for maximum expression of the antigens were also defined. Actively growing "S. aureus" Smith strain culture was used to challenge lactating GF-1 strain mice which had been vaccinated with various capsule
antigen preparations. Capsule antigen production was evaluated using shaker flask and fermenter cultures. Immunogenicity evaluations using single vaccinations showed that semi-purified capsule preparations elicited a protective response against challenge. Mice vaccinated twice showed that oil and aluminum hydroxide adjuvanted capsule
antigens protected against challenge, but DDA (dimethyldioctadecylammonium bromide) adjuvanted capsule antigens resulted in more mastitis than non-vaccinated controls. Cultural evaluations showed that media high in nitrogen and
carbohydrate content and grown at pH 5.5 resulted in the greatest amount of capsule antigen production. Capsular antigens may be more useful in preventing "S. aureus" mastitis than whole cell preparations. Media containing high concentrations of nitrogen source and carbohydrate are necessary to obtain large amount of capsular antigen. A
culture pH of 5.5 promotes the production of additional antigens not found when grown at higher or lower pH levels.
