A medium recommended by the Harmonised European Pharmacopoeia for isolation and identification of Staphylococcus aureus from non-sterile pharmaceutical products.
Conforms to USP/EP/JP performance specification. The peptone and beef extract provide a source of nitrogen, essential vitamins and amino acids. The mannitol is a fermentable carbohydrate and the high level of sodium chloride provides a selective environment favourable to Staphylococcus aureus. Phenol red acts as a pH indicator changing from red to yellow when acid is produced by the fermentation of mannitol. The majority of S. aureus ferment mannitol producing yellow colonies, occasional strains of coagulase-negative Staphylococci may also ferment mannitol. It is necessary to confirm the identity of presumptive S. aureus colonies by other means e.g. coagulase, protein A, DN’ase, thermonuclease or latex agglutination. According to the Harmonised European Pharmacopoeia, subculture is carried out onto the medium after enrichment in Casein Soya Bean Digest Broth.