1. Institute for Hygiene and the National Consulting Laboratory on Hemolytic Uremic Syndrome, University of Münster, Robert-Koch-Str. 41, 48149 Münster, Germany
2. National Reference Center for Salmonella and Other Enteric Pathogens, Robert Koch Institute, Branch Wernigerode, Burgstr. 37, 38855 Wernigerode, Germany
3. Departments of Pediatrics and Molecular Microbiology, Washington University School of Medicine, 660 S. Euclid Ave., St. Louis, Missouri