Table 1.
Bacterial stains used in this study.
| Strain | Source | Serotype | Sorbitol | Type of Stx | eae | CD50/ml* ± standard deviation (×1011) |
|---|---|---|---|---|---|---|
| EDL933 | Reference strain | O157:H7 | – | 1/2 | γ | 8·5 ± 2·9 |
| 1271–84 | Reference strain | O157:H7 | – | 2/2c | γ | 2·6 ± 0·5 |
| 125/99 | HUS | O157:H7 | – | 2 | γ | 17·0 ± 6·2 |
| 119/01 | NBD | O157:H7 | – | 2 | γ | 40·9 ± 4·1 |
| 108/01 | HUS | O157:H7 | – | 2 | γ | 17·1 ± 5·9 |
| 605/03 | NBD | O157:H7 | – | – | γ | – |
*
CD50/ml was determined on Vero cells by triplicate, as described in Materials and methods. The cytotoxic effect was neutralized using Shiga toxin 1 (Stx1)- and Stx2-specific monoclonal antibodies (mAb 13C4 and BC5BB12 respectively), provided by Dr N. A. Strockbine, Centers for Disease Control and Prevention, Atlanta, GA, USA (CDC). NBD, non-bloody diarrhoea; HUS, haemolytic uraemic syndrome.