1. Department of Veterinary Pathobiology, Texas A&M University, College Station, Texas, USA
2. Department of Agricultural Sciences, West Texas A&M University, Canyon, Texas, USA
3. Department of Veterinary Integrative Biosciences, Texas A&M University, College Station, Texas, USA
4. School of Veterinary Medicine, Texas Tech University, Amarillo, Texas, USA
5. U.S. Department of Agriculture, Agricultural Research Service, College Station, Texas, USA
6. Center for Food Safety, University of Georgia, Griffin, Georgia, USA