1. Medical Microbiology & Virology, Aberdeen Royal Infirmary, Foresterhill, Aberdeen AB25 2ZN, UK
2. Department of Microbiology, Royal Infirmary of Edinburgh, 51 Little France Crescent, Edinburgh EH16 4SA, UK
3. Strathclyde Institute of Pharmacy and Biomedical Science, University of Strathclyde, 161 Cathedral Street, Glasgow G4 0RE, UK