Comparison of Growth Kinetics of Various Pathogenic E. coli on Fresh Perilla Leaf

Growth kinetics for Escherichia coli O157:H7 in perilla leaves were compared to those of pathogenic E. coli strains, including enteropathogenic (EPEC), enterotoxigenic (ETEC), enteroinvasive (EIEC) and other enterohemorrhagic (EHEC) at 13, 17, 24, 30 and 36 °C. Models for lag time (LT), specific growth rate (SGR) and maximum population density (MPD) as a function of temperature were developed. The performance of the models was quantified using the ratio method and an acceptable prediction zone method. Significant differences in SGR and LT among the strains were observed at all temperatures. Overall, the shortest LT was observed with E. coli O157:H7, followed by EPEC, other EHEC, EIEC and ETEC, while the fastest growth rates were noted in EPEC, followed by E. coli O157:H7, ETEC, other EHEC and EIEC. The models for E. coli O157:H7 in perilla leaves was suitable for use in making predictions for EPEC and other EHEC strains. Keywords: E. coli O157:H7; pathogenic E. coli; perilla leaves; growth model; validation