TABLE 2.
On-to-off switching in strains used in this study
| Strain | Serotype | Switching frequencya |
|---|---|---|
| STEC strains | ||
| 97E12 | O26:H11 | 0.101 |
| 97E16 | O26:H11 | 0.147 |
| 97E2 | O111:H− | 0.168 |
| 97E22 | O111:H− | 0.154 |
| Non-ST-producing O157 strains | ||
| 96-39 | O157:H45 | 0.110 |
| 96-11 | O157:H45 | 0.101 |
| EPEC strains | ||
| 1646-3 | O55:H− | 0.186 |
| 2 | O55:H6 | 0.035 |
| 85/91-5 | O55:H7 | 0.134 |
| 70 | O55:H7 | 0.021 |
| F57076 | O55:H7 | 0.101 |
| PE163 | O55:H7 | 0.001 |
| PE182 | O55:H7 | 0.029 |
| 807-257 | O55:H7 | 0.077 |
| F43341 | O111:H12 | 0.077 |
| 118 | O111:H12 | 0.134 |
| ETEC strains | ||
| CH5667 | 0.027 | |
| CH28991 | 0.001 | |
| O22 | 0.004 | |
| EAggEC strains | ||
| 17-2 | 0.022 | |
| 253-1-1 | 0.026 | |
| K-12 strain (DH5α) | 0b |
a
Switching frequency per cell per generation. Rates were determined as the means of the frequencies calculated from three separate colonies based on a method described previously (11).
b
The transition rates from fimbriate to nonfimbriate of the K-12 strain CSH50 were reported as 0.001 per cell per generation (7).