1. Department of Veterinary Science and Microbiology, University of Arizona, Tucson, Arizona 85721
2. Anaerobe Reference Laboratory, University Hospital of Wales, Heath Park, Cardiff CF4 4XW, United Kingdom
3. Rollins Animal Disease Diagnostic Laboratory, Raleigh, North Carolina 27607
4. Ontario Veterinary College, University of Guelph, Guelph, Ontario N1G2W1, Canada