Effect of antibodies to staphylococcal α and β 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 α and β 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 α and β toxins of S aureus and culture supernatant; cell damage and S aureus adherence to cells were measured. Results - Antisera to α, β, and α + β toxins inhibited cytotoxicity of S aureus culture supernatant. Antiserum to α + β toxin was the most effective inhibitor of cytotoxicity and antiserum to β 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 α and α + β toxins decreased the number of S aureus clusters per dish, but antiserum to β toxin had no significant effect. Antiserum to α + β toxin decreased the percentage of epithelial cells with adhered S aureus, but neither antiserum to α nor β toxin had significant effect. Antiserum to S aureus decreased the percentage of S aureus adhered, number of clusters per dish, number of organisms per cluster, and percentage of epithelial cells with S aureus adhered. Conclusions - Antibodies to staphylococcal α and β 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.