1. KU Leuven, Department of Microbiology and Immunology, Rega Institute, Herestraat 49, B-3000 Leuven, Belgium.
2. VIB, Center for the Biology of Disease, Herestraat 49, B-3000 Leuven, Belgium.
3. Microbiology Unit, Faculty of Sciences and Bioengineering Sciences, Vrije Universiteit Brussel, Pleinlaan 2, B-1050 Brussels, Belgium.