1. Department of Animal Health and Biomedical Sciences, University of Wisconsin—Madison, 1656 Linden Drive, Madison, Wisconsin 53706
2. Department of Bacteriology, Kimron Veterinary Institute, P.O. Box 12, Bet Dagan 50250, Israel
3. INSERM U431, UFR Médecine, CS83021, Avenue Kennedy, 30908 Nimes Cedex 02, France