1. Tanga Centre, National Institute for Medical Research, Tanga P.O. Box 5004, Tanzania
2. Department of Clinical Sciences, Lund University, 221 84 Lund, Sweden
3. Bacterial Reference Center, Statens Serum Institut, 2300 Copenhagen, Denmark
4. Department of Bacteria, Statens Serum Institut, Parasites and Fungi, 2300 Copenhagen, Denmark