1. Department of Microbiology; University Hospital of Antwerp; Wilrijkstraat 10 Edegem Belgium
2. Department of Infectious and Parasitic Diseases; Faculty of Veterinary Medicine; Université de Liège; Boulevard de Colonster, 20, B42 Sart-Tilman 4000 Liège Belgium
3. Department of Animal Health; Institute of Tropical Medicine; Nationalestraat 155 2000 Antwerp Belgium
4. Department of Bacteriology and Immunology; Veterinary and Agrochemical research Centre; Groeselenberg 99 1190 Brussels Belgium