1. 1Department of Food Science (Food Microbiology), The Queen's University of Belfast, Newforge Lane, Belfast BT9 7AD, Northern Ireland
2. 2Northern Ireland Public Health Laboratory, Department of Bacteriology, Belfast City Hospital, Belfast BT9 7AD, Northern Ireland
3. 3Department of Agriculture and Rural Development for Northern Ireland, Department of Food Microbiology, Newforge Lane, Belfast BT9 7AD, Northern Ireland