In Vitro Adherence of Staphylococcus Aureus to Bovine Mammary Gland Epithelial Cells

摘要

A simple in vitro test system to study the adherence of bacteria to bovine mammary gland epithelial cells is described. This test system can be used as a laboratory model to study the relative attachment of bacterial species associated with mastitis. The effects of a number of physical, chemical, enzymatic and biological factors on the adherence of a strain of Staphylococcus aureus were studied using this test system. The numbers of bacteria adhering to epithelial cells were higher when logarithmic growth phase cultures were used (4–6 h). Adherence was not affected by pretreatment of bacteria with NaCl or EDTA, or within the pH range 6–8, but was inhibited by heat (60°C for 30 min) and trypsin and papain pretreatments, whereas wheat germ lipase pretreatment enhanced adherence. Sodium lauryl sulphate, Triton X-100, and Tween 80 inhibited adherence. Adherence was also inhibited by milk from a quarter infected with S. aureus and by specific anti-staphylococcal antiserum. These findings suggest that the staphylococcal adhesin may be protein in nature.