Potentiated antimicrobial agents

A method for treating and/or preventing a microbial infection in a subject, comprising co-administrating in the subject in need thereof an antimicrobial agent and a compound having the following formula I:

• wherein R1, R2, R3 are each, independently of one another, H, OH, a (C1-C6)alkyl, (C2-C6)alkenyl, (C1-C6)haloalkyl, (C1-C6)alkoxy, (C2-C6)alkenoxy, (C1-C6)haloalkoxy, —O—CO—(C1-C6)alkyl group,
• A is a heteroatom or a -(Het)-R′ or R-(Het)-R′ group wherein R, R′, are each, independently of one another, a (C1-C4)alkanediyl group optionally substituted by C1-C4 alkyl radicals and Het is a heteroatom,
• in a compound of formula (I):
• antimicrobial agent mass ratio, ranging from 8:1 to 1:10,
• in that the antimicrobial agent is not a terpenoid or a phenylpropanoid,
• 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
• wherein [C] is the concentration according to the invention of compound (I) to be used on the strain A,
• [MIC] is the MIC measured for compound (I), alone, on this strain A,
• x is higher than or equal to 100.