Reduction of in vitro growth in Flavobacterium columnare and Saprolegnia parasitica by products containing peracetic acid

摘要

Commercial products containing peracetic acid (PAA) are strong disinfectants with a wide spectrum of antimicrobial activity and have been suggested as potential therapeutic agents in aquaculture. The aim of this study was to compare the in vitro reduction of growth on two fish pathogens, Flavobacterium columnare and Saprolegnia parasitica, by seven commercial PAA-containing products. Flavobacterium columnare was exposed to 1, 2, 4, 6, 8 and 10 mg?L?1 PAA and S. parasitica was exposed to 0.5, 1, 2, 4, 6, 8 and 10?mg?L?1 PAA in petri dishes for 24?h incubation. The reduction of growth was measured in comparison to a PAA-free control. A reduction of the growth was observed for both pathogens with increasing PAA concentration. Hydrogen peroxide (H₂O₂) possibly has a role in the effectiveness of the products, since products with lower PAA concentrations had a higher concentration of H₂O₂. The commercial products with a low concentration of PAA and a low PAA:H₂O₂-ratio were generally more effective against pathogens. The practical application of the products with low PAA concentration should be prioritized.