1. Universitätsklinik für Viszerale Chirurgie und Medizin, Inselspital, Bern University Hospital, Department for BioMedical Research (DBMR), University of Bern, Murtenstrasse 35, 3008 Bern, Switzerland.
2. Institute for Medical Microbiology, RWTH University Hospital, Pauwelsstrasse 30, D-52074 Aachen, Germany.