1. Department of Biology and Wildlife Diseases; Faculty of Veterinary Hygiene and Ecology; University of Veterinary and Pharmaceutical Sciences Brno; Brno; Czech Republic
2. Department of Diagnostic Medicine and Pathobiology; College of Veterinary Medicine; Kansas State University; Manhattan; KS; USA
3. Institute of Microbiology and Epizootics; Veterinary Faculty; Free University Berlin; Berlin; Germany