Patent ID: 6617149
Filing Date: 2003-09-09
Classification: C12Q,G01N

Abstract:
An isolation plating medium for use in processes for the presumptive identification of Escherichia coli 0157:H7 from a test sample that also contains other bacteria including other strains of Escherichia coil, both Escherichia coil 0157:H7 and the other strains of Escherichia coil being beta-galactosidase producers during metabolism, comprising at least one carbohydrate that is a member of the group sorbitol, salicin, inositol, adonitol, mannitol, dulcitol, d-sorbitol, L-arabinose, L-rhamnose, d-xylose, trehalose, d-mannose, and melibiose, Escherichia coil 0157:H7 being incapable of fermenting said carbohydrate but other strains of Escherichia coli fermenting said carbohydrate, a pH indicator dye that changes the color of the plating medium to a first color when the pH of the medium changes, a chromogenic substrate that reacts to beta-galactosidase to form a precipitate in the plating medium of a second color which contrasts with the first color, whereby a microorganism which ferments the carbohydrate but does not produce beta-galactosidase will produce colonies in the plating medium of the first color, a microorganism which does not ferment the carbohydrate but produces beta-galactosidase including Escherichia coli 0157:H7 will produce colonies in the plating medium of the second color, and microorganisms which ferment the carbohydrate and produce beta-galactosidase including the other strains of Escherichia coli will produce colonies in the plating medium of a third color which is the color that results from the mixing of the first and second colors, and a sufficient mass of an agent to solidify the mixture.