Antibacterial activity evaluation of microcin J25 against diarrheagenic Escherichia coli.

The inhibitory activities of known microcins were evaluated against some diarrheagenic Escherichia coli strains. Some antibacterial properties of microcin J25, the most active one, were studied. A rapid two-step purification was performed. The MIC and the minimum bactericidal concentration of J25 against E. coli O157:H7 were 1 and 100 μg ml−1, respectively. A 104-CFU ml−1 contamination by this strain was destroyed in milk and meat extract by 6.25 μg of J25 ml−1 and in half-diluted egg yolk by 50 μg of J25 ml−1.