1. VIB, Department of Molecular and Cellular Interactions, Laboratory of Microbial Interactions, Vrije Universiteit Brussel, Building E, room 6.6, Pleinlaan 2, B-1050 Brussels, Belgium
2. UMR6026, Interactions Cellulaires et Moléculaires, Université de Rennes 1, Campus de Beaulieu, avenue du Général Leclerc, 35042 Rennes cedex, France