Table 2.
Effects of phenolic compound-antibiotic combinations on the inhibition of Escherichia coli ATCC25922.
| Drug Combinations | FICI |
|---|---|
| GA + AMP | 0.504 (A) |
| GA + Amoxicillin | 1.008 (I) |
| GA + Ceftiofur | 1.001 (I) |
| GA + Penicillin G | 1.004 (I) |
| GA + Cefotaxime | 0.563 (A) |
| GA + ERY | 1.002 (I) |
| GA + Thiamphenicol | 0.281 (S) |
| GA + Marbofloxacin | 0.625 (A) |
| HAMA + AMP | 1.001 (I) |
| HAMA + Amoxicillin | 0.625 (A) |
| HAMA + Ceftiofur | 1.002 (I) |
| HAMA + Penicillin G | 1.002 (I) |
| HAMA + Cefotaxime | 1.001 (I) |
| HAMA + ERY | 0.375 (S) |
| HAMA + Thiamphenicol | 0.500 (S) |
| HAMA + Marbofloxacin | 0.625 (A) |
| Epicatechin + AMP | 1.004 (I) |
| Epicatechin + Amoxicillin | 1.001 (I) |
| Epicatechin + Ceftiofur | 0.625 (A) |
| Epicatechin + Penicillin G | 1.002 (I) |
| Epicatechin + Cefotaxime | 0.563 (A) |
| Epicatechin + ERY | 0.504 (A) |
| Epicatechin + Thiamphenicol | 1.008 (I) |
| Epicatechin + Marbofloxacin | 0.504 (A) |
| AMP + Epicatechin gallate | 1.004 (I) |
| Amoxicillin + Epicatechin gallate | 1.001 (I) |
| Ceftiofur + Epicatechin gallate | 0.625 (A) |
| Penicillin-G + Epicatechin gallate | 1.002 (I) |
| Cefotaxime + Epicatechin gallate | 1.002 (I) |
| ERY + Epicatechin gallate | 1.001 (I) |
| Thiamphenicol + Epicatechin gallate | 0.625 (A) |
| Marbofloxacin + Epicatechin gallate | 0.516 (A) |
| Epigallocatechin + AMP | 0.504 (A) |
| Epigallocatechin + Amoxicillin | 1.008 (I) |
| Epigallocatechin + Ceftiofur | 0.625 (A) |
| Epigallocatechin + Penicillin G | 1.008 (I) |
| Epigallocatechin + Cefotaxime | 0.502 (A) |
| Epigallocatechin + ERY | 0.516 (A) |
| Epigallocatechin + Thiamphenicol | 1.008 (I) |
| Epigallocatechin + Marbofloxacin | 0.504 (A) |
Five independent experiments (n = 5) were performed. A, additive; AMP, ampicillin; ERY, erythromycin; FICI, fractional inhibitory concentration index; GA, gallic acid; HAMA, hamamelitannin; I, indifferent; S, synergy; Synergy, FICI ≤ 0.5; Additive, 0.5 < FICI ≤ 1; Indifferent, 1 < FICI ≤ 4; Antagonist, FICI > 4.