1. Institute for Medical Microbiology, Immunology and Hygiene, University Hospital Cologne and Faculty of Medicine, University of Cologne, Cologne, Germany
2. Institute for Medical Microbiology and Virology, University of Oldenburg, Oldenburg, Germany
3. German Centre for Infection Research (DZIF)
4. Goethe University Frankfurt, University Hospital, Institute of Medical Microbiology and Infection Control, Frankfurt am Main, Germany
5. Institute of Medical Microbiology and Hygiene, University Hospital Tuebingen, Tuebingen, Germany
6. National Reference Laboratory for Multidrug-Resistant Gram-negative Bacteria, Department of Medical Microbiology, Ruhr-University Bochum, Bochum, Germany