1. Department of Nutrition & Food Science and Joint Institute for Food Safety & Applied Nutrition, University of Maryland, College Park, Maryland, USA
2. Division of Microbiology, Office of Regular Science, Center for Food Safety & Applied Nutrition, U.S. Food & Drug Administration, College Park, Maryland, USA
3. Biostatistics Branch, Center for Food Safety & Applied Nutrition, U.S. Food & Drug Administration, College Park, Maryland, USA
4. Department of Microbiology & Immunology, Stanford School of Medicine, Stanford University, Palo Alto, California, USA
5. Division of Animal & Food Microbiology, Office of Research, Center for Veterinary Medicine, U.S. Food & Drug Administration, Laurel, Maryland, USA