1. Department of Genetics, University of Groningen and University Medical Center Groningen , Groningen, the Netherlands
2. Medical Center - University of Freiburg, Institute for Infection Prevention and Hospital Epidemiology , Freiburg, Germany
3. Department of Medical Microbiology, University of Groningen and University Medical Center Groningen , Groningen, the Netherlands
4. Department of Pediatrics, University of Groningen and University Medical Center Groningen , Groningen, the Netherlands
5. Department of Gastroenterology and Hepatology, University of Groningen and University Medical Center Groningen , Groningen, the Netherlands