1. Institute for Veterinary Medical Research, Centre for Agricultural Research, Hungarian Academy of Sciences, Hungária krt. 21, Budapest 1143, Hungary
2. Virological Research Group, Szentágothai Research Centre, University of Pécs, Pécs, Hungary
3. Institute of Biology, Faculty of Sciences, University of Pécs, Pécs, Hungary
4. KU Leuven-University of Leuven, Department of Microbiology and Immunology, Laboratory for Clinical and Epidemiological Virology, Rega Institute for Medical Research, B-3000 Leuven, Belgium
5. Department of Veterinary Public Health, University of Bari, S.p. per Casamassima km 3, 70010 Valenzano, Bari, Italy