1. Northern Ireland Public Health Laboratory, Department of Bacteriology, Belfast City Hospital, Belfast, Northern Ireland, UK
2. Laboratory for Molecular Biology, School of Environmental Health Sciences, Azabu University, Sagamihara, Japan
3. School of Biomedical Sciences, University of Ulster, Coleraine
4. School of Dentistry, Queen's University of Belfast, Royal Group of Hospitals, Grosvenor Road, Belfast, Northern Ireland, UK