Table 2.
Synergistic effect of EGCG in combination with tetracycline against reference and V. cholerae MDR strains.
| Strain | MIC (µg/mL) of Extracts (a) | FIC (a) | MIC (µg/mL) of Tetracycline (b) | FIC (b) | FICI | Outcome | ||
|---|---|---|---|---|---|---|---|---|
| Alone | Combination | Alone | Combination | |||||
| P48 (O1) | 125.0 | 0.97 | 0.008 | 62.5 | 0.061 | 0.001 | 0.009 | Synergistic |
| 22136 (O139) | 125.0 | 0.97 | 0.008 | 0.78 | 0.008 | 0.01 | 0.018 | Synergistic |
| N16961 (Reference) |
125.0 | 0.97 | 0.008 | 3.91 | 0.004 | 0.001 | 0.009 | Synergistic |
Abbreviations: EGCG, (−)-epigallocatechin gallate; FIC, fractional inhibitory concentration; FICI, fractional inhibitory concentration index; MIC, minimum inhibitory concentration. FIC (a) = MIC of EGCG in the combination/MIC of EGCG alone; FIC (b) = MIC of tetracycline in the combination/MIC of tetracycline alone; FICI = FIC (a) + FIC (b). The values were interpreted as a synergistic effect for FICI ≤ 0.5.