1. Regional Laboratory for Medical Microbiology, Dordrecht, the Netherlands
2. Beatrix hospital/Rivas Group, Gorinchem, the Netherlands
3. Albert Schweitzer Hospital, Dordrecht, the Netherlands
4. Department of Medical Microbiology and Infectious Diseases, Erasmus University Medical Centre, Rotterdam, the Netherlands
5. Department of Biostatistics, Erasmus University Medical Centre, Rotterdam, the Netherlands
6. Department of Medical Microbiology, University Medical Centre, Groningen, the Netherlands