Comparison of EDTA and Apo-Lactoferrin with Lysozyme on the Growth of Foodborne Pathogenic and Spoilage Bacteria.

Combinations of ethylenediaminetetraacetic acid (EDTA) or apo-lactoferrin (Apo-Lf) and lysozyme were evaluated for their antimicrobial effectiveness in ultra-high temperature pasteurized milk against Pseudomonas fluorescens , Salmonella typhimurium , Escherichia coli O157:H7, and Listeria monocytogenes . Neither P. fluorescens nor S. typhimurium growth was influenced by EDTA, Apo-Lf or lysozyme alone or in combinations. Escherichia coli O157:H7 was inhibited by EDTA alone, but no increase in antimicrobial effectiveness was noted in the presence of lysozyme. In contrast, EDTA and lysozyme had a significant interactive antimicrobial effect against L. monocytogenes . Apo-Lf, at concentrations up to 2.5 mg/ml, displayed similar inhibition patterns with lysozyme against the E. coli O157:H7 and L. monocytogenes however, the magnitude of inhibition was much less and of little practical significance. When evaluated over time, EDTA (1.5-2.5 mg/ml)-lysozyme (150 μg/ml) slowed growth of E. coli and was bactericidal to L monocytogenes . Apo-lactoferrin (15 mg/ml)-lysozyme (150 μg/ml) had little practical effect on E. coli growth but did slow growth of L. monocytogenes .