1. Central Unit for Animal Research and Animal Welfare Affairs, University Hospital, Heinrich - Heine - University, Düsseldorf, Germany
2. Retired - Microbiological Diagnostics, German Cancer Research Centre, Heidelberg, Germany
3. Biological and Medical Research Center (BMFZ), Heinrich-Heine-University, Düsseldorf, Germany
4. Leibniz Institute DSMZ - German Collection of Microorganisms and Cell Cultures, Inhoffenstraße 7B, 38124 Braunschweig, Germany
5. Department of Veterinary and Animal Science, Faculty of Health and Medical Sciences, University of Copenhagen, København, Denmark