A Comparative Assessment of Media for the Isolation and Enumeration of Coagulase Positive Staphylococci from Foods. A Report from a Working Party of the Public Health Laboratory Service*

S ummary : A direct plating procedure was used in 7 laboratories for detecting and enumerating coagulase positive staphylococci in 424 foods and for the recovery of staphylococci from 233 foods experimentally inoculated in the laboratory. Coagulase positive staphylococci were isolated from 46 (10·9%) of the 424 routine foods. For general use a reliable and selective medium is required which is inexpensive, simple to prepare and stable on storage. Eleven selective media were tested and of these phenolphthalein‐diphosphate agar with polymyxin, milk‐ or cream‐salt agar and mannitol‐salt agar were considered to be the most useful.