1. Center for Veterinary Medicine, U.S. Food and Drug Administration, Laurel, Maryland, USA.
2. Division of Foodborne, Waterborne, and Environmental Diseases, National Center for Emerging and Zoonotic Infectious Diseases, Centers for Disease Control and Prevention, Atlanta, Georgia, USA.
3. National Center for Toxicological Research, U.S. Food and Drug Administration, Jefferson, Arkansas, USA.
4. Food Safety and Inspection Service, U.S. Department of Agriculture, Athens, Georgia, USA.