1. Department of Veterinary Pathobiology, College of Veterinary Medicine, Texas A&M University, College Station, Texas
2. Department of Veterinary Integrated Biomedical Sciences, College of Medicine, Texas A&M University System Health Science Center, College Station, Texas
3. Department of Medical Microbiology and Immunology, University of California, Davis, California
4. Department of Medical Microbial and Molecular Pathogenesis, College of Medicine, Texas A&M University System Health Science Center, College Station, Texas