1. Institute of Medical Microbiology, University Hospital Münster, Münster, Germany
2. Statens Serum Institute, Copenhagen, Denmark
3. Department of Veterinary Medicine, University of Cambridge, Cambridge, United Kingdom
4. Department of Medical Microbiology, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
5. Institute of Hygiene, University Hospital Münster, Münster, Germany