1. 1 University of Agricultural Sciences and Veterinary Medicine Department of Infectious Diseases 400372 Cluj-Napoca Manastur 3–5 Romania
2. 2 University of Agricultural Sciences and Veterinary Medicine Discipline of Cellular Biology, Histology and Embryology, Faculty of Veterinary Medicine 400372 Cluj-Napoca Manastur 3–5 Romania
3. 3 Szent István University Department of Microbiology and Infectious Diseases, Faculty of Veterinary Science H-1143 Budapest Hungária krt. 23–25 Hungary
4. 4 Central Veterinary Institute Budapest Hungary