Synergistic effect of nisin and heat treatment on the growth of Escherichia coli O157:H7

A combination of nisin and heat treatment was found to inhibit Escherichia coli O157:H7 effectively. After organisms were heated at 50, 52.5, and 55 degrees C for 5, 10, and 15 min, respectively, nisin was incorporated into the plates of E. coli O157:H7 at 0, 25, 50, and 100 IU/ml. The concentration of 100 IU/ml nisin significantly inhibited the growth of E. coli O157:H7 heated at 50 and 52.5 degrees C for 15 min. Nisin treatment at 100 IU/ml for 6 h resulted in the elimination of E. coli O157:H7 heated at 55 degrees C for 10 and 15 min.