Table 18.
Results of checkerboard assays of colistin in combination with resveratrol from Cannatelli et al. (2018) [120].
| Strains | Phenotype | Colistin MICs (µg/mL) at Different Resveratrol Concentrations (µg/mL) | ||||||
|---|---|---|---|---|---|---|---|---|
| Resveratrol Concentration (µg/mL) | ||||||||
| 0 | 8 | 16 | 32 | 64 | 128 | 256 | ||
| E. coli LC711/14 | COL-R | 8 | 4 | 2 * | 1 * | 0.25 * | 0.25 * | 0.125 * |
| E. coli LC761/12 | COL-R | 4 | 0.5 * | 0.5 | 0.25 * | 0.125 * | 0.125 * | 0.125 * |
| E. coli FI-4451 | COL-R | 8 | 8 | 8 | 4 | 4 | 4 | 4 |
| E. coli FI-4531 | COL-R | 8 | 4 | 4 | 4 | 4 | 2 * | 2 * |
| E. coli FI-4592 | COL-R | 8 | 4 | 4 | 4 | 4 | 4 | 4 |
| E. coli LC902/14 | COL-R | 8 | 4 | 4 | 4 | 4 | 2 * | 2 * |
| C. braakii CA-26 | COL-R | 8 | 4 | 4 | 4 | 4 | 2 * | 2 * |
| S. maltophilia 157 | COL-R | 32 | 4 | 2 * | 1 * | 0.5 * | 0.125 * | 0.125 * |
| E. cloacae CIP6085 | COL-R | 128 | 128 | 32 * | 8 * | 0.5 * | 0.25 * | 0.125 * |
| K. pneumoniae KKBO-1 a | MDR/ COL-S | 0.5 | 0.5 | 0.5 | 0.5 | 0.5 * | 0.5 | 0.5 |
| K. pneumoniae KKBO-4 | MDR/ COL-R | 64 | 64 | 64 | 16 * | 8 * | 4 * | 4 * |
| K. pneumoniae KPB-1 a | MDR/ COL-S | 0.5 | 0.5 | 0.5 | 0.5 | 0.5 | 0.5 | 0.5 |
| K. pneumoniae KPB-2 | MDR/ COL-R | 4 | 4 | 4 | 4 | 2 | 1 * | 0.5 * |
| K. pneumoniae KK207-1 a | MDR/COL-S | 0.5 | 0.5 | 0.5 | 1 | 0.5 | 0.5 | 0.5 |
| K. pneumoniae KK207-2 | MDR/ COL-R | 64 | 64 | 64 | 64 | 4 * | 1 * | 0.5 * |
| K. pneumoniae 6884 | MDR/ COL-R | 8 | 8 | 8 | 8 | 4 * | 1 * | 1 * |
| K. pneumoniae KPFan b | COL-R | 32 | 32 | 16 | 8 * | 2 * | 1 * | 1 * |
| K. pneumoniae KPGP1 b | COL-R | 32 | 32 | 32 | 32 | 2 * | 1 * | 1 * |
| A. Baumanii N50 | MDR/COL-R | 64 | 64 | 64 | 64 | 8 * | 1 * | 1 * |
| S. marcescens CCUG1647T | COL-R | >128 | >128 | >128 | >128 | 16 * | 1 * | 1 * |
| P. mirabilis NO-051 | COL-R | >128 | >128 | >128 | >128 | >128 | >128 | 8 * |
a These strains were the colistin-susceptible (COL-S) precursors of colistin-resistant (COL-R) K. pneumoniae KKBO-4, K. pneumoniae KPB-2, and K. pneumoniae KK207-2 strains, respectively. Resveratrol MICs were > 512 mg/L for all tested strains. b These COL-R strains were selected in vitro, using two COL-S precursors. Multidrug-resistant phenotypes (MDR) refer to strains resistant to carbapenems (imipenem and meropenem), ciprofloxacin, and amikacin. * Combinations in which colistin/resveratrol combinations yielded a synergistic activity (FICI ≤ 0.5). The lower concentration of resveratrol needed for restoring susceptibility to colistin is shaded in gray.