Thermal inactivation of extraintestinal pathogenic Escherichia coli suspended in ground chicken meat

Extraintestinal pathogenic Escherichia coli (ExPEC)is a foodborne pathogen responsible for urinary tract infections, sepsis, and neonatal meningitis. Retail poultry meat has been identified as a reservoir for ExPEC. Information regarding virulence factors (VF)or antibiotic resistance (AR)involvement in resistance to food processing technologies is lacking. In this study, ground chicken meat (GCM)was inoculated three different ExPEC multiisolate cocktails, including Uropathogenic E.coli (UPEC), Neonatal Meningitis causing E.coli (NMEC), and Food-Source (FS)isolates. D ₁₀ (55, 60, and 65 °C)(e.g. 7.34, 0.56, 0.05 min, respectively)and z-values (4.62–5.89 °C)were found consistent with, or slightly lower than, those of E. coli O157:H7 in low fat meat and poultry. There was little difference in D ₁₀ and z-value when ExPEC were recovered on APC Petrifilms versus E. coli Petrifilms. The D ₁₀ of 19 individual ExPEC isolates determined at 55 °C ranged from 1.84 to 7.58 min, with an average of 4.46 min. Differences in D ₁₀ were found between isolates possessing or lacking the fdeC, sinH, cnf1, gad, ompT, iha, FimH and Sat genes. These results indicate the ExPEC can be inactivated in poultry meat using the same conditions that are used for E. coli O157:H7. While the possibility exists that ExPEC genotype (VF)can influence survival to thermal processing, AR had no effect on resistance to heat in this study.