Patent ID: 7563592

Claim:
A composition for detecting at least one strain and/or species of microorganism, comprising a culture medium, at least one type of divalent or trivalent metal cation and a chromogenic substrate with the following general formula: in which: R 1 is a target part or H, and R 2 is a target part or H, with at least one of R 1 and R 2 being a target part, R 3 is H, SO 3 H, Cl, Br, F, I, NO 2 , NH 2 , NR 9 R 10 , or an acylamino, aminoaryl or aminoacylamino group of the type NHCOX, with X being an alkyl, aryl or aralkyl group or an α-amino acid residue, R 4 is H, SO 3 H, Cl, Br, F, I, NO 2 , NH 2 , NR 9 R 10 , OH or an acylamino aminoaryl or aminoacylamino group of the type NHCOX, with X being an alkyl, aryl or aralkyl group or an α-amino acid residue, alternatively, R 3 and R 4 form bonds with one another to create a ring with at least five sides, R 5 , R 6 , R 7 and R 8 are each independently selected from the group consisting of H, a halogen, OH, SO 3 H, an alkyl group and an alkoxy group, and R 9 and R 10 are independently an alkyl, aryl, aralkyl group, or either R 9 or R 10 is a ring structure with the other, either R 10 or R 9 , being a hydrogen atom.