Abstract
1 Department of Veterinary Clinical Sciences, College of Veterinary Medicine, University of Minnesota, St Paul, MN, USA
2 Department of Microbiology, Immunology and Molecular Genetics, University of Kentucky College of Medicine, Lexington, KT, USA
3 Department of Microbiology and Immunology, Virginia Commonwealth University School of Medicine, Richmond, VA, USA
4 Department of Pathology, Microbiology and Immunology, School of Veterinary Medicine, Davis, CA, USA