1. Department of Microbiology, The Technical University of Denmark, Lyngby DK-2800, Denmark1;
2. Department of General and Marine Microbiology, Göteborg University, S-413 90 Göteborg, Sweden2;
3. Lehrstuhl für Mikrobiologie, Technische Universität München, D-80290 Munich, Germany3;
4. Institute of Medical Microbiology, University of Aarhus, Århus DK-8000, Denmark4; and
5. School of Microbiology and Immunology, University of New South Wales, Sydney 2052, Australia5