1. Department of Microbiology and Immunology, Midwestern University, Glendale, AZ, USA
2. Prion Research Center, Department of Microbiology, Immunology, and Pathology, College of Veterinary Medicine and Biomedical Sciences, Colorado State University, Fort Collins, CO, USA
3. Colorado Department of Agriculture, Animal Health Division, Broomfield, CO, USA
4. United States Department of Agriculture, APHIS, VS, National Veterinary Services Laboratory, Ames, IA, USA
5. United States Department of Agriculture, APHIS, VS, Center for Veterinary Biologics, Ames, IA, USA