Use of Conventional Media and Thin Agar Layer Method for Recovery of Foodborne Pathogens from Pressure-treated Poultry Products

The recovery of 5 pathogens from minced chicken (MC) and liquid whole egg (LWE) was determined with tryptone soya agar (TSA), selective medium, and thin agar layer (TAL; selective medium overlaid with TSA) to evaluate high-pressure effects at 200, 300, 400, and 500 MPa for 1 and 5 min at 20 °C. At 400 MPa for 5 min, Escherichia coli inactivation was 4 log in MC and 5.5 log in LWE, whereas no Salmonella Typhimurium, Yersinia enterocolitica, or Listeria monocytogenes were detected in either product. Staphylococcus aureus was the most pressure-resistant. In general, counts on the 3 media were not different. The TAL method allows differentiation of the inoculated pathogens from background microbiota.