Enhancement of in vitro phagocytosis of Staphylococcus aureas by polymorphonuclear leucocytes

Polymorphs collected from ewes which had been infected with live staphylococci and immunised with a killed staphylococcal vacccine, had significantly enhanced capacity for phagocytosis of staphylococci compared with polymorphs from ewes which received only a killed vaccine. The numbers of viable bacteria were greatly reduced when blood serum or whey were incorporated in incubation mixtures compared to incubation mixtures containing only polymorphs and staphylococci. When serum was used in the incubation mixtures, the numbers of staphylococci which survived were significantly less than when colostral or milk whey was used. No significant difference was observed between whey collected from locally immunised mammary glands and that from non-immunised glands within each group.