1. Departments of Microbiology1 and
2. Infectious Diseases,2 Umeå University, S-901 87 Umeå, Sweden;
3. Unité de Bactériologie Moléculaire et Médicale, Institut Pasteur, Paris, France3; and
4. Department of Occupational and Public Health, The Faeroese Hospital System, FR 100 Tórshavn, The Faeroe Islands4