1. Institute of Mathematics, University of Kassel, 34132 Kassel, Germany
2. CNRS, Inria and the University of Lorraine, 54506 Nancy, France
3. MPI Informatics and Saarland University, 66123 Saarbrücken, Germany
4. Laboratory of Pathogen Host Interactions UMR 5235, University of Montpellier and CNRS, 34095 Montpellier, France