Description
This media basically conforms to the formulation of Vogel and Johnson1 for the isolation of coagulase positive mannitol fermenting Staphylococcus aureus from foods and clinical specimens and complies with the specifications of the United States Pharmacopoeia USP2. Staph.aureus appear as characteristic black colonies surrounded by a yellow zone which indicates mannitol fermentation and is the differentiating characteristic of the majority of strains of Staphylococcus aureus. from other staphylococci. Most other bacteria are inhibited by the combination of glycine, lithium chloride and tellurite3. The tellurite is reduced by staphylococci to give the black colonies and fermentation of mannitol by coagulase positive staphylococci is indicated by the change in colour of the phenol red indicator from red to yellow. If mannitol is not fermented, the yellow zone does not develop and the medium around the colonies stays red, and can darken.
