Table 3.
MICs of S. officinalis used alone and in combination with four antibiotics
| Antibiotics | Strains | MIC (μg/ml) | FICI a | Interaction b | ||
|---|---|---|---|---|---|---|
| S.officinalis | Antibiotic | S. officinalis + Antibiotic | ||||
| CLR | SS1 | 160 | 0.016 | 160 + 0.001/10 + 0.016 | 1.0625 | Additive |
| LQ2# | 320 | 6.4 | 160 + 1.6/10 + 6.4 | 0.75/1.031 | Additive | |
| LEF | SS1 | 160 | 1.6 | 160 + 0.05 | 1.0625 | Additive |
| 700,392 | 160 | 0.8 | 160 + 0.05/10 + 0.8 | 1.0625 | Additive | |
| MTZ | SS1 | 160 | 1.6 | 80 + 0.8 | 1.0 | Additive |
| 700,392 | 160 | 1.6 | 160 + 0.1/10 + 1.6 | 1.0625 | Additive | |
| LQ2# | 320 | 6.4 | 160 + 3.2 | 1.0 | additive | |
| AMO | SS1 | 160 | 0.4 | 160 + 0.025/10 + 0.4 | 1.0625 | Additive |
| 700,392 | 160 | 0.1 | 160 + 0.006 | 1.0625 | Additive | |
| LQ2# | 320 | 3.2 | 160 + 1.6 | 1.0 | Additive | |
aFractional inhibitory concentration index, FICI = (MIC of S. officinalis in combination/MIC of S. officinalis alone + MIC of Antibiotic in combination/MIC of Antibiotic alone). bInteraction between S. officinalis and every antibiotic was defined according to the following principle: FICI ≤ 0.5, synergistic; 0.5 < FICI ≤ 4, additive; FICI > 4, antagonistic