Antagonistic Action of Lactobacillus acidophilus Toward Intestinal and Foodborne Pathogens in Associative Cultures 1.

Lactobacillus acidophilus exerted antagonistic actions on growth of Staphylococcus aureus , Salmonella typhimurium , enteropathogenic Escherichia coli , and Clostridium perfringens when grown with each in associative cultures. S. aureus and C. perfringens were more sensitive to the inhibition than were S. typhimurium and E. coli . The amount of the antagonism produced varied among strains of L. acidophilus and could not be directly related to amounts of acid produced; hydrogen peroxide produced by the lactobacilli appeared to be partially responsible for the antagonistic interaction. The inhibitory effect was produced also under anaerobic conditions in a pre-reduced medium.