1. Agriculture and Agri-Food Canada, London, ON, Canada N5V 4T3
2. Department of Infectious Diseases, Institute of Biomedicine, Sahlgrenska Academy, and Centre for Antibiotic Resistance Research (CARe), University of Gothenburg, SE-413 46, Gothenburg, Sweden
3. USDA-Agriculture Research Service, Lincoln, NE 68583, USA
4. Zoetis, 1930 Zaventem, Belgium
5. University of Helsinki, Department of Microbiology, 00014 Helsinki, Finland