1. Foodborne Toxin Detection & Prevention Research Unit, Western Regional Research Center, USDA-ARS, 800 Buchanan St., Albany, CA 94710, USA
2. Department of Medicine and Epidemiology, School of Veterinary Medicine, University of California at Davis, One Shields Avenue, Davis, CA 95616, USA
3. Department of Pathology, Microbiology, and Immunology, School of Veterinary Medicine, University of California at Davis, One Shields Avenue, Davis, CA 95616, USA
4. Department of Pathology, Microbiology, and Immunology, School of Veterinary Medicine & California Animal Health and Food Safety Laboratory, University of California at Davis, One Shields Avenue, Davis, CA 95616, USA
5. Department of Biological Sciences, University of the Pacific, 3601 Pacific Avenue, Stockton, CA 95211, USA