Effect of antibodies to staphylococcal alpha and beta toxins and Staphylococcus aureus on the cytotoxicity for and adherence of the organism to bovine mammary epithelial cells

Abstract

Objective: To determine the effect of antibodies to staphylococcal alpha and beta toxins and Staphylococcus aureus on the toxicity for and adherence of S aureus to bovine mammary epithelial cells.

Sample population: Cultured bovine mammary epithelial cells and Staphylococcus aureus obtained from a cow with mastitis.

Procedure: Cultured bovine epithelial cells were incubated with antisera to alpha and beta toxins of S aureus and culture supernatant; cell damage and S aureus adherence to cells were measured.

Results: Antisera to alpha, beta, and alpha + beta toxins inhibited cytotoxicity of S aureus culture supernatant. Antiserum to alpha + beta toxin was the most effective inhibitor of cytotoxicity and antiserum to beta toxin was the least effective. All 3 antisera decreased the percentage of S aureus adhered to the mammary epithelial cell monolayers and numbers of organisms per cluster of adhered bacteria. In this study, antisera to alpha and alpha + beta toxins decreased the number of S aureus clusters per dish, but antiserum to beta toxin had no significant effect. Antiserum to alpha + beta toxin decreased the percentage of epithelial cells with adhered S aureus, but neither antiserum to alpha nor beta toxin had significant effect. Antiserum to S aureus decreased the percentage of S aureus adhered, number of clusters perdish, number of organisms per cluster, and percentage of epithelial cells with S aureus adhered.

Conclusions: Antibodies to staphylococcal alpha and beta toxins inhibit adherence to and cytotoxicity of S aureus for bovine mammary epithelial cells, and antibodies to S aureus inhibit adherence of S aureus to bovine mammary epithelial cells.