1. Institute of Medical Immunology CVK; Charité-University Medical Center; Berlin; Germany
2. Institute for Microbiology and Hygiene CBF, Charité-University Medical Center; Berlin; Germany
3. Department of Gastroenterology, Hepatology and Infectious Diseases; Otto-von-Guericke University; Magdeburg; Germany
4. Department of Internal Medicine and Gastroenterology; SCHLEI-Klinikum Schleswig MLK GmbH; Schleswig; Germany