1. Department of Microbiology, University of Medicine, 4 Chałubińskiego Street, 50-368 Wrocław, Poland
2. Department of Hygiene of Food of Animal Origin, National Veterinary Research Institute, 57 Partyzantów Street, 24-100 Puławy, Poland
3. Military Institute of Hygiene and Epidemiology, 2 Lubelska Street, 24-100 Puławy, Poland