1. Department of Medical Microbiology, Leiden University Medical Center, Leiden, the Netherlands
2. Surveillance and Response Support Unit, European Centre for Disease Prevention and Control, Stockholm, Sweden
3. Institut für Hygiene und Umweltmedizin, Charité Universitätsmedizin Berlin, Berlin, Germany
4. Microbiology Unit, Université Catholique de Louvain, Louvain-la-Neuve, Brussels, Belgium
5. Department of Microbiology, East-Tallinn Central Hospital, Tallinn, Estonia
6. Department of Infectious Disease Surveillance and Control, Bacteriology Unit, National Institute for Health and Welfare, Helsinki, Finland
7. Hôpital Saint-Antoine, Paris, France
8. National Reference Laboratory for Clostridium difficile, Pierre et Marie Curie University, Paris, France
9. Department of Hospital Epidemiology and Hygiene, National Center for Epidemiology, Budapest, Hungary
10. Departments of Infection Prevention and Microbiology, Oslo University Hospital Rikshospitalet, Oslo, Norway
11. Department of Medical Microbiology, Medical University of Warsaw, Warsaw, Poland
12. National Institute for Microbiology and Immunology, Laboratory of Anaerobic Bacteria, Cantacuzino Institute, Bucharest, Romania
13. Department of Microbiology, Clinical Center of Serbia, Belgrade, Serbia
14. Health Protection Scotland, Glasgow, United Kingdom
15. Austrian Agency for Health and Food Safety (AGES), Vienna, Austria
16. Department of Microbiology and Infection Control, Statens Serum Institut, Copenhagen, Denmark
17. University of Leeds, Leeds, United Kingdom
18. Leeds Teaching Hospitals NHS Trust, Leeds, United Kingdom