1. Department of Physiology and Pharmacology, Karolinska Institutet, Stockholm, Sweden;
2. Centre for Clinical Research Västmanland, Uppsala University, Västmanland County Hospital, Västerås, Sweden;
3. Department of Clinical Microbiology, Västmanlands Hospital, Västerås, Sweden;
4. Unit of Infectious Diseases, Department of Medicine Huddinge, Karolinska Institutet, Stockholm, Sweden