1. Department of Internal Medicine, Division of Nephrology University of Groningen, University Medical Center Groningen Groningen The Netherlands
2. Department of Medical Microbiology University of Groningen, University Medical Center Groningen Groningen The Netherlands
3. Department of Pathology & Medical Biology Division of Pathology University of Groningen, University Medical Center Groningen Groningen The Netherlands
4. Department of Epidemiology University of Groningen, University Medical Center Groningen Groningen The Netherlands
5. Department of Medical Microbiology University of Utrecht University Medical Center Utrecht Utrecht The Netherlands