1. Department of Pathobiology, 264 Greene Hall, College of Veterinary Medicine, Auburn University, Auburn, AL 36849
2. Population Health and Reproduction, School of Veterinary Medicine, University of California, Davis, CA 95616
3. University of California, California Animal Health and Food Safety Laboratory Tulare Branch, 18830 Road 112, Tulare, CA 93274
4. Foster Farms, 14519 Collier Road, Livingston, CA 95315