1. Institute of Medical Microbiology and Hygiene, University of Saarland Hospital, D-66421 Homburg/Saar, Germany
2. Institute of Microbiology, University Hospital of Muenster, D-48149 Muenster, Germany
3. Department of Laboratory Medicine, Karolinska Institutet, Huddinge University Hospital, S-141 86 Huddinge, Sweden
4. Department of Medicine 1, University Hospital Heidelberg, D-69115 Heidelberg, Germany