1. Department of Chemistry and Pharmacy University of Erlangen-Nürnberg Nikolaus-Fiebiger-Str. 10 91058 Erlangen Germany
2. Institute of Clinical Microbiology and Hygiene University of Regensburg Franz-Josef-Strauß-Allee 11 93053 Regensburg Germany
3. Institute of Medical Microbiology and Hygiene University of Regensburg Franz-Josef-Strauß-Allee 11 93053 Regensburg Germany