1. Department of Anesthesiology and Intensive Care Medicine, Faculty of Medicine, University Hospital of Cologne, University of Cologne, Kerpener Straße 62, 50937 Cologne, Germany
2. Institute for Medical Microbiology, Immunology and Hygiene, Faculty of Medicine, University Hospital of Cologne, University of Cologne, Goldenfelsstraße 19-21, 50935 Cologne, Germany