1. 1Public Health England, Food, Water and Environmental Microbiology Laboratory Porton, Porton Down, Salisbury, SP4 0JG, UK
2. 2Public Health England, Food, Water and Environmental Microbiology Laboratory London, 61 Colindale Avenue, London, NW9 5EQ, UK
3. 3University of Liverpool, Institute of Infection and Global Health, Liverpool, L69 7BE, UK
4. 4Gastrointestinal Bacteria Reference Unit, Public Health England, 61 Colindale Avenue, London, NW9 5EQ, UK
5. 5Public Health England, Food, Water and Environmental Microbiology Laboratory York, National Agri-Food Innovation Campus, Sand Hutton York, YO41 1LZ, UK
6. 6Public Health England, Food Water and Environmental Microbiology Laboratory Preston, Royal Preston Hospital, Sharoe Green Lane, Fulwood Preston, PR2 9HT, UK
7. 7Public Health England, Food, Water and Environmental Microbiology Laboratory Birmingham, Good Hope Hospital, Rectory Road, Sutton Coldfield, B75 7RR, UK