Abstract: A plating medium for the presumptive identification of Bacillus cereus, Bacillus thuringiensis and/or Bacillus anthrasis that includes a nutrient base to facilitate growth of Bacillus cereus, Bacillus thuringiensis and Bacillus anthrasis, a chromogenic substrate that changes color responsive to the presence of PC-PLC enzymes, and an ingredient that promotes the expression of the PC-PLC enzyme. In a preferred embodiment, the medium includes a second chromogenic substrate that changes color responsive to the presence of PI-PLC enzymes and an ingredient that promotes the expression of the PI-PLC enzyme.

Abstract: An isolation plating medium for the identification of Salmonella bacteria in a sample containing a plurality of different bacteria comprising a mixture of a carbohydrate capable of being a metabolic source for Salmonella bacteria and supporting colonies of Salmonella bacteria, a pH indicator dye that changes the color of the plating medium to a first color different from the color of the medium responsive to a change in the pH of the medium, a first substrate that does not react with Salmonella bacteria and injects color into the medium of a second color responsive to the presence of beta-galactosidase, the second color contrasting with the first color and the color of the medium, a second substrate that does not react with Salmonella bacteria and injects color into the medium of substantially the same color as the second color responsive to the presence of beta=galactosidase, and an ingredient for thickening the mixture in sufficient quantity to solidify the mixture.