1. Institute for Medical Microbiology, University of Munich, Veterinaerstr. 13, 80539 Munich, Germany1
2. Department of Pathology, Microbiology and Immunology, School of Veterinary Medicine, University of California, Davis, California, USA2
3. Department of Veterinary Tropical Diseases, Faculty of Veterinary Science, University of Pretoria, Onderstepoort, South Africa3