Thermal Inactivation of Shiga-Toxin Producing Escherichia Coli (Stec) in Frozen Ground Beef

Approach:
Ground beef will be purchased from a local retailer, inoculated with a five-strain cocktail of pathogenic E. coli, formed into patties, and held frozen for up to 3 months. The patties will be cooked, with and without prior thawing, on commercial grills and pathogen viability will be quantified. Parameters to be evaluated will include the fat content of ground beef, serotype of E. coli, freezing duration and thawing regimen for patties, cooking temperature, and grill type as detailed in Appendix A. The experimental design was derived from multiple conversations between key players from both FSIS and ARS. Ongoing discussions between ARS and FSIS as to the nature, number, and scope of the project may necessitate that the timeframe for completion be extended and/or the cost be increased.