Indolamine derivatives for detecting peptidase activity in culture media

A method for revealing a peptidase activity in a microorganism culture medium comprising the steps of:

• adding to the culture medium at least one compound of formula (I):
• X—NH—R (I)
• in which X represents an optionally substituted indol-3-yl group and R represents the acyl residue of an amino acid or of a peptide, the amine group(s) present in R being optionally in by protected form, with the exception of a compound of formula (I) for which X represents a 5-bromoindol-3-yl group and R represents a leucyl or alanyl residue,
• detecting the formation of a coloured or fluorescent product in said medium, and
• correlating the formation or absence of formation of a coloured or fluorescent product with the presence or absence of said peptidase activity, respectively.

Method for detecting a microorganism or a group of microorganisms in a sample which contains said microorganism or said group of microorganisms or which is likely to contain said microorganism or said group of microorganisms, comprising the steps of:

• adding to the culture medium at least one compound of formula (I):
• X—NH—R (I)
• in which X represents an optionally substituted indol-3-yl group and R represents the acyl residue of an amino acid or of a peptide, the amine group(s) present in R being optionally in protected form, with the exception of a compound of formula (I) for which X represents a 5-bromoindol-3-yl group and R represents a leucyl or alanyl residue,
• detecting the formation of a coloured or fluorescent product in said culture medium, and
• comparing, where appropriate, the coloration or fluorescence obtained with that obtained with an authentic sample of the microorganism or of the group of microorganisms sought.