1. Department of Statistics; College of Agriculture and Life Sciences; Iowa State University; Ames IA USA
2. Department of Veterinary Diagnostic and Production Animal Medicine; College of Veterinary Medicine; Iowa State University; Ames IA USA
3. Diagnostic Bacteriology Laboratory; National Veterinary Services Laboratories, USDA-APHIS; Ames IA USA
4. US Department of Agriculture; Bacterial Epidemiology and Antimicrobial Resistance Research Unit; Russell Research Center; Athens GA USA
5. Department of Veterinary Microbiology and Preventive Medicine; College of Veterinary Medicine; Iowa State University; Ames IA USA