1. Outbreaks Section of the Eastern Laboratory, Richard B. Russell Agricultural Research Center, Food Safety Inspection Service, U.S. Department of Agriculture, Athens, Georgia.
2. Bacterial Epidemiology and Antimicrobial Resistance Research Unit, Richard B. Russell Agricultural Research Center, Agriculture Research Service, U.S. Department of Agriculture, Athens, Georgia.
3. Department of Population Health and Pathobiology, College of Veterinary Medicine, North Carolina State University, Raleigh, North Carolina.