1. Division of Animal and Food Microbiology, U.S. FDA, CVM, Laurel, Maryland.
2. Texas Tech University, Department of Animal and Food Science, Lubbock, Texas.
3. U.S. FDA–CFSAN, Office of Applied Research and Safety Assessment (OARSA), Laurel, Maryland.
4. USDA–ARS, U.S. Meat Animal Research Center, Meat Safety and Quality Research Unit, Clay Center, Nebraska.