Synergism between hydrogen peroxide and seventeen acids against six bacterial strains.
Résumé
AIMS: The objective of this study was to evaluate the bactericidal efficacy of hydrogen peroxide administered in combination with 17 mineral and organic acids authorized for use in the food industry. METHODS AND RESULTS: The assays were performed on a 96-well microplate using a microdilution technique based on the checkerboard titration method. The six selected strains were reference strains and strains representative of contaminating bacteria in the food industry. Each synergistic hydrogen peroxide/acid combination found after 5-min contact time at 20°C in distilled water was then tested in conditions simulating four different use conditions. Thirty-two combinations were synergistic in distilled water; twenty-five of these remained synergistic with one or more of the four mineral and organic interfering substances selected. Hydrogen peroxide/formic acid combination was synergistic for all six bacterial strains in distilled water and remained synergistic with interfering substances. Six other combinations maintained their synergistic effect in the presence of an organic load but only for one or two bacterial strains. CONCLUSIONS: Synergistic combinations of disinfectants were revealed, among them the promising hydrogen peroxide/formic acid combination. SIGNIFICANCE AND IMPACT OF THE STUDY: A rapid screening method was proposed and used to reveal the synergistic potential of disinfectant and/or sanitizer combinations.