Table 2.
Effects of ciprofloxacin and azithromycin at subinhibitory concentrations on Shiga toxin (Stx) 1 and/or Stx2 production by various clinical isolates.
| Fold increase in Stxa | |||||
|---|---|---|---|---|---|
| Ciprofloxacin | Azithromycin | ||||
| Strain | Toxin | Stx1 | Stx2 | Stx1 | Stx2 |
| 86-24 | Stx2 | … | 67–188 | … | 0.2–0.8 |
| 94–9004 | Stx2 | … | 154–499 | … | 1–2 |
| 92–9140 | Stx2 | … | 111–418 | … | 0.025–0.5 |
| 95–8061 | Stx2c | … | 111–243 | … | 0.9–1.1 |
| 94–8052 | Stx1 | 1–2 | … | 1–2 | … |
| 92–9204 | Stx1 | 1–2 | … | 1–2 | … |
| 97–8075 | Stx1/Stx2 | 1–2 | ~500 | 1–2 | ~1 |
| 97–8023 | Stx1/Stx2 | 3–4 | 700 | 3–4 | 1 |
a
Toxin production values were calculated as fold increases (Stx concentration in the test tube with antibiotic/Stx concentration in control tube without antibiotic). Results are given as ranges for the subinhibitory concentration of each antibiotic.