[Study of combinations of antimicrobial agents. Development of the method]

We developed and validated a micromethod similar to the checkerboard method in antibiotherapy to study the efficiency of antiseptic and disinfectant molecules. The determination of the FBC index (Fractional Bactericidal Concentration) on 4 reference strains (Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, Enterococcus hirae) for 4 associations (2-benzyl-4 chlorophenol--iodophor; cetrimide-iodophor, 2 benzyl-4 chlorophenol--formaldehyde; hexamidine--formaldehyde) revealed 2 synergistic associations and 2 antagonistic associations for one or more strains.