The object of the invention is to provide a potentiated antimicrobial agent for use in treating a microbial infection, characterized in that the antimicrobial agent is used in combination with a compound of the following formula I:in a compound of formula (I): antimicrobial agent mass ratio, ranging from 8:1 to 1:10 and in that the microbial infection is induced in particular by a strain A pathogen and in that on this strain A, the concentration of compound (I) meets the following equation:[C]<；[MIC]/x where [C] is the concentration according to the invention of compound (I) to be used on the strain A[MIC] is the MIC measured for the compound (I), alone, on this strain A x is higher than or equal to 100, advantageously to 1 000, more advantageously x is between 2 000 and 10 000, or even higher than 50 000.
