Efficacy of Petrifilm™ E. coli Count Plates for E. coli and Coliform Enumeration.

The Petrifilm E. coli Count plate (PEC) method was compared to the AOAC MPN method to determine the efficacy of the PEC method to detect E. coli and coliforms in 115 inoculated cheese samples, 94 vegetables samples, and in 100 naturally contaminated poultry samples. The PEC method was compared to two other coliform plate count methods. The 24 h PEC method is as good as or better than the AOAC MPN method for the detection of E. coli. In addition, qualitative results suggest that the PEC method may be more sensitive than the 9 tube MPN method for the detection of very low numbers of E. coli. Comparable coliform results were obtained.