In this study, we compared the effectiveness of armoise and clove bud essential oils (EOs) and the combination of low concentrations of copper (Cu) and lactic acid (LA) against E. coli O157:H7 in a laboratory medium. Three strains of Escherichia coli O157:H7 (ATCC700599, ATCC51659, and ATCC43895) were used in this study. Antibacterial activity was determined by measuring the turbidity of a broth medium and by determination of bacterial populations. Our results showed that armoise (0.15% v/v), clove bud (0.1% v/v) EOs, or Cu (50 ppm) in combination with LA (0.2% v/v) caused a minimum 5.0 log reduction of E. coli O157:H7 in the laboratory medium. Cu in combination with LA may thus be preferable to EOs in food in order to control the growth of foodborne pathogens. In addition, the combination treatment of Cu and LA could provide the food industry with a practical approach to reducing the risk of foodborne pathogens.
Keywords: E. coli O157:H7; armoise; clove bud; copper; essential oil; lactic acid.