Table 1.
Antibacterial effect of CA, LFX and CA + LFX.
| Group | MIC for single drug (MICs, μg/mL) | MIC for drug combination (MICc, μg/mL) | |||
|---|---|---|---|---|---|
| CA | LFX | CA | LFX | FICI | |
| Strain A | 2047.96 ± 3.70 | 31.93 ± 3.24 | 512 | 8 | 0.25 |
| Strain B | 2047.78 ± 5.43 | 64.02 ± 7.15 | 512 | 16 | 0.16 |
| Strain C | 2048.22 ± 6.31 | 32.11 ± 2.84 | 512 | 8 | 0.25 |
Data are expressed as mean ± SD for each group, the experiment was repeated by three independent experiments. MIC Minimal inhibitory concentration, CA Chlorogenic acid, LFX Levofloxacin, FICI Fractional inhibitory concentration index. FICI ≤ 0.5 indicates synergy, FICI > 0.5–4.0 indicates no interaction, FICI > 4.0 indicates antagonism. Strain A, B and C are the three strongest ESBLs biofilm positive strains from the 20 strains of ESBLs biofilm positive strains.