1. Molecular Identification Services Unit, Centre for Infections, Health Protection Agency, 61 Colindale Avenue, London NW9 5EQ, UK
2. Kennedy Institute of Rheumatology Division, Faculty of Medicine, Imperial College, ARC Building, 1 Aspenlea Road, London W6 8LH, UK
3. Applied and Functional Genomics Unit, Centre for Infections, Health Protection Agency, 61 Colindale Avenue, London NW9 5EQ, UK