Antimicrobial activities of plant essential oils and their components against antibiotic-susceptible and antibiotic-resistant foodborne pathogens

Food processors, regulatory agencies, microbiologists, physicians, and the general public have been increasingly concerned with the growing number of foodborne illness outbreaks caused by pathogens. This chapter summarizes the authors' own studies designed to define relative activities (potencies) of essential oils (EOs) and oil constituents against foodborne pathogens in buffers and in food. Mycobacterium avium subspecies paratuberculosis (MAP) is responsible for serious infections in cattle, causing Johne's disease. Its role in humans is not well elucidated, but it may be associated with Crohn's disease and diabetes. Oregano oil was the most effective antimicrobial of the compounds tested against all of the bacteria. Phenolic EOs apparently exert their lethal effect by permeabilizing the membrane of cells. In a collaborative study, the heat resistance of a cocktail of eight Salmonella serotypes is assessed in raw ground beef in the presence of sodium lactate, oregano oil, and in combinations of these two GRAS-listed ingredients.