1. Department of Microbiology and Infection Control, Statens Serum Institut, Copenhagen S, Denmark.
2. Department of Clinical Microbiology, Slagelse Sygehus, Slagelse, Denmark.
3. Department of Clinical Microbiology, Odense University Hospital, Odense, Denmark.
4. Department of Clinical Microbiology, Aalborg University Hospital, Aalborg, Denmark.
5. Department of Clinical Microbiology, Copenhagen University Hospital, Hvidovre Hospital, Hvidovre, Denmark.