1. Catholic University Leuven, Research Group for Microbial Adhesion, Department of Periodontology, Kapucijnenvoer 7, 3000 Leuven, Belgium;
2. UCLA, School of Dentistry, 10833 Le Conte Avenue, Los Angeles, CA, USA;
3. Catholic University Leuven, Centre for Molecular Diagnostics, Herestraat 49, 3000 Leuven, Belgium; and
4. Catholic University Leuven, Centre for Human Genetics, Herestraat 49, 3000 Leuven, Belgium