1. 1 Leeds Teaching Hospitals NHS Trust, Leeds LS1 3EX, UK
2. 2 CHU de Nancy, Service de Maladies Infectieuses, Nancy, France
3. 3 Université de Lorraine, Université Paris Descartes, EA 4360 Apemac, Nancy, France
4. 4 Infectious Diseases Unit, Hospital Carlos G Durand, Buenos Aires, Argentina
5. 5 Leeds Institute for Health Sciences, University of Leeds, Leeds LS2 9LJ, UK
6. 6 Microbiology, Aberdeen Royal Infirmary, Foresterhill, Aberdeen AB25 2ZN, UK
7. 7 Infection Control Programme, Geneva University Hospitals and Faculty of Medicine, Geneva, Switzerland
8. 8 Ninewells Hospital and Medical School, Dundee DD1 9SY, UK