1. Department of Production Animal Clinical Sciences; Norwegian School of Veterinary Science; PB 8146 Dep, 0033 Oslo Norway
2. Department of Basic Sciences and Aquatic Medicine; Norwegian School of Veterinary Science; PB 8146 Dep, 0033 Oslo Norway
3. Department of Food Safety and Infection Biology; Norwegian School of Veterinary Science; PB 8146 Dep, 0033 Oslo Norway