Staphylococcus Aureus in Cheddar Cheese

Abstract

Summary Experiments were carried out to determine the factors affecting the growth of staphylococci in raw milk and Cheddar cheese. Milk with a relatively low standard plate count was found to support an active growth at 32° C. and a moderate growth at 22° C.; whereas, almost no growth took place, even at 32° C., in milk with a high standard plate count. Large numbers of staphylococci in milk would he most apt to occur when bacteriologically clean milk is held at a fairly high temperature. Staphylococci grew poorly during cheese-making and most of them were concentrated in the curd. The initial staphylococcus count of milk seems to be the most important factor determining the number of staphylococci in cheese. Prompt cooling of milk after milking and heat treatment before cheese-making are suggested to minimize any public health hazard associated with the presence of staphylococci in cheese.