1. Bacteriology Division, Scientific Institute of Public Health, 14 Wytsman street, B-1050 Brussels, Belgium 2,4Laboratory of Microbiology, Faculty of Sciences2 and BCCMTM/LMG Bacteria Collection4, Ghent University, K. L. Ledeganckstraat 35, B-9000 Ghent, Belgium 3AFSSA, 31 Av. Tony Garnier, 69364 Lyon cedex 07, France