1. Department of Pathology, Bacteriology and Avian Diseases; Faculty of Veterinary Medicine; Ghent University; Merelbeke Belgium
2. Department of Biomedical molecular biology; Faculty of Sciences; Ghent University; Gent Belgium
3. Veterinary Research Institute; Brno Czech Republic
4. Department of Virology, Parasitology, Immunology; Faculty of Veterinary Medicine; Ghent University; Merelbeke Belgium