1. Department of Medical Microbiology and Genito-Urinary Medicine, University of Liverpool, Liverpool L69 3GA, UK
2. Centre for Microbiology Research, Kenya Medical Research Institute, PO Box 43640, Nairobi, Kenya
3. Department of Medical Microbiology, Kenyatta National Hospital, PO Box 20723, Nairobi, Kenya
4. Central Veterinary Investigations Laboratory, PO Private Bag, Kabete, Kenya