1. Queensland Department of Primary Industries, Animal and Plant Health Service, Oonoonba Veterinary Laboratory, P.O. Box 1085, Townsville, Queensland, Australia, 4810
2. School of Public Health and Tropical Medicine, James Cook University, Douglas, Townsville, Queensland, Australia, 4811
3. Australian Salmonella Reference Centre, Institute of Medical and Veterinary Science, Frome Road, Adelaide, South Australia, Australia, 5000