1. Department of Production Animal Studies, Faculty of Veterinary ScienceUniversity of Pretoria Pretoria South Africa
2. Agriculture Research Council, Onderstepoort Veterinary ResearchBacteriology Laboratory Pretoria South Africa
3. Department of Veterinary Tropical Disease, Faculty of Veterinary SciencesUniversity of Pretoria Pretoria South Africa
4. ECTADFood and Agriculture Organization Dar es Salaam, Tanzania
5. School of Veterinary Medicine, Faculty of Medical SciencesUniversity of the West Indies St. Augustine Trinidad and Tobago