1. Institute for Molecular Biology of Infectious Diseases; Julius Maximilians University Würzburg, Josef-Schneider-Str. 2/Bau D15, D-97080 Würzburg, and Institute for Hygiene, University of Münster; Robert-Koch-Str. 41 D-48149 Münster Germany
2. Institute for Molecular Biology of Infectious Diseases; Julius Maximilians University Würzburg; Josef-Schneider-Str. 2/Bau D15 D-97080 Würzburg Germany
3. Institute for Molecular Biology of Infectious Diseases; Julius Maximilians University Würzburg, Josef-Schneider-Str. 2/Bau D15, D-97080 Würzburg, and German Academy of Sciences Leopoldina; Emil-Abderhalden-Str. 37 D-06108 Halle/Saale Germany