Table. 2. Results of the combination of gentamicin and methylxanthines, caffeine and theophylline against S. aureus and P. aeruginosa.
| Bacterial | strains | Agent | MIC (μg/mL) | FIC | FICI | Outcome | |
|---|---|---|---|---|---|---|---|
| Alone | Gentamicin + Extract | ||||||
| S. aureus | 1 | gentamicin | > 80 | > 80 | 1 | 2 | Indifference |
| S. aureus | 2 | methylxanthines | > 200 | > 80 | 1 | 0.56 | Partial synergy |
| gentamicin | 12.5 | 6.25 | 0.5 | ||||
| S. aureus | 3 | methylxanthines | > 200 | 12.5 | 0.06 | 2 | Indifference |
| gentamicin | > 80 | > 80 | 1 | ||||
| S. aureus | 4 | methylxanthines | > 200 | > 80 | 1 | 2 | Indifference |
| gentamicin | > 80 | > 80 | 1 | ||||
| S. aureus (ATCC 6538p) | 5 | methylxanthines | > 200 | > 80 | 1 | 2 | Indifference |
| gentamicin | 0.312 | 0.312 | 1 | ||||
| P. aeruginosa (ATCC 9027) | 1 | methylxanthines | > 200 | 200 | 1 | 2 | Indifference |
| gentamicin | 0.312 | 0.312 | 1 | ||||
S. aureus, Staphylococcus aureus; P. aeruginosa, Pseudomonas aeruginosa; MIC, minimum inhibitory concentration; FICI, fraction inhibitory concentration index.