ICMSF methods studies. X. An international comparative study of four media for the enumeration of Staphylococcus aureus in foods

Abstract

An international comparative study, undertaken by 6 laboratories to assess the performance of 4 selective media commonly used for the enumeration of S. aureus in foods, revealed that Baird-Parker agar performed most satisfactorily. There was no significant difference among milk salt, tellurite polymyxin egg yolk and [potassium rhodanide-atidione-sodium azide-egg yolk-pyruvate] agars. The type of food examined appeared to influence the performance of the media, but no specific patterns could be determined. Cultures yielding 3+ and 4+ coagulase reactions are most likely to possess thermostable nuclease activity, and are therefore most likely to be S. aureus.