Table 1. Bacterial isolates included in the study.
| Strain | Synonym | Year | Stx | Source | Origin |
| NVH-734a | NIPH-11060424 | 2006 | stx2 | Patient no 2 | Norway |
| NVH-847 | NIPH-11060708 | 2006 | stx2 | Patient no 9 | Norway |
| NVH-848 | NIPH-11060707 | 2006 | - | Patient no 9 | Norway |
| NVH-849 | NIPH-11060747 | 2006 | - | Patient no 10 | Norway |
| NVH-760 | 625/06 | 2006 | - | Fermented sausage, home of patient 7 | Norway |
| NVH-737 | 2006 | - | Fermented sausage | Norway | |
| NVH-763 | 2006 | - | Food | Norway | |
| NVH-661 | NIPH-10306923 | 2003 | stx2 | Patient | Norway |
| NVH-731 | NIPH-11051601 | 2005 | stx2 | Patient | Norway |
| cdc-08-201 | Not known | Maine, USA | |||
| cdc-08-202 | Not known | Virginia, USA |
All isolates are E. coli O103:H25.
a
Referred to as Norwegian outbreak strain (NOS).