1. Department of Veterinary and Biomedical Science, College of Veterinary Medicine, University of Minnesota, St. Paul, MN 55108, USA.
2. Biomedical Genomics Center, University of Minnesota, St. Paul, MN 55108, USA.
3. Department of Microbiology and Immunology, Weill Medical College and Program in Immunology, Weill Graduate School of Medical Sciences of Cornell University, New York, NY 10021, USA.
4. Department of Veterinary Pathobiology, College of Veterinary Medicine, Texas A&M University, College Station, TX 77843, USA.
5. Division of Infectious Diseases, Tufts University School of Veterinary Medicine, North Grafton, MA 01536, USA.