1. Medical Faculty of the University of Tübingen; D-72076 Tübingen Germany
2. Cellular and Molecular Microbiology Division, Interfaculty Institute of Microbiology and Infection Medicine; University of Tübingen; D-72076 Tübingen Germany
3. German Center for Infection Research; Partner site Tübingen; D-72076 Tübingen Germany
4. Department of Orthopaedic Surgery; University Hospital of Tübingen; D-72076 Tübingen Germany