1. Department of Pathobiology, Pharmacology and Zoological Medicine, Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133, Merelbeke 9820, Belgium
2. Department of Veterinary Pathology, Microbiology, and Parasitology, Faculty of Veterinary Medicine, University of Nairobi, P.O Box 29053, Nairobi 00100, Kenya
3. Department of Animal Science, Chuka University, P.O Box 109-00625, Chuka 00625, Kenya
4. Chair Poultry Health Sciences, Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133, Merelbeke 9820, Belgium
5. Department of Food Sciences, Faculty of Veterinary Medicine, University of Liège, Avenue de Cureghem 10, Liège 4000, Belgium
6. Department of Biology, Faculty of Science and Technology, University of Nairobi, P.O Box 30197 Nairobi 00100, Kenya
7. Consultant, P.O Box 34405, Nairobi 00100, Kenya
8. DSM-BIOMIN Research Center, Technopark 1, Tulln 3430, Austria
9. International Livestock Research Institute (ILRI), P.O Box 30709, Nairobi 00100, Kenya
10. Department of Medical Biochemistry and Microbiology, Uppsala University, Uppsala SE-751 05, Sweden
11. Department of Clinical Sciences, Swedish University of Agricultural Sciences, Uppsala SE-750 07, Sweden