Biological control of postharvest decays of apple can prevent growth of Escherichia coli O157 : H7 in apple wounds

Fresh cells of the antagonist Pseudomonas syringae at 2.4 x 10(8) CFU/ml in oculated into wounds of 'Golden Delicious' apple prevented Escherichia coli O157:H7 (concentrations ranging from 2.4 x 10(5) to 2.4 x 10(7) CFU/ml) fr om growing in the wounds. This occurred when the two microorganisms were co -inoculated or inoculation with E. coli O157:H7 was conducted 1 or 2 days a fter inoculation with the antagonist. In similar tests, application of the commercial formulation of this antagonist prevented the growth of E, coli O 157:H7 in wounds when inoculated 1 or 2 days after application of the antag onist. Populations of E. coli O157:H7 in wounds treated with water (control ) before inoculation with this pathogen increased approximately 2 log units during the first 48 h after inoculation. These results indicate that bioco ntrol agents developed for controlling storage decays of fruits may have th e additional benefit of preventing the growth of foodborne pathogens in fre shly wounded tissue of intact and fresh-cut fruits.