Table 2.
Analysis of the Fractional Inhibitory Concentration Index (FICI) of Cysteamine with Cystic Fibrosis-relevant Antibiotics versus P. aeruginosa
| Tobramycin | Ciprofloxacin | Colistin | Gentamicin | |||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Strain | Syn | Add | Ind | Syn | Add | Ind | Syn | Add | Ind | Syn | Add | Ind |
| PAO1 | 6 | 5 | 0 | 0 | 3 | 5 | 3 | 4 | 4 | 1 | 5 | 0 |
| Pa14 | 0 | 7 | 0 | 0 | 2 | 5 | 5 | 7 | 0 | 0 | 5 | 0 |
| Pa058 | 0 | 8 | 0 | 0 | 11 | 1 | 0 | 6 | 4 | 0 | 6 | 0 |
| 57388A | 2 | 5 | 0 | 0 | 2 | 1 | 2 | 6 | 0 | 1 | 6 | 0 |
| 57388D | 4 | 4 | 0 | 0 | 4 | 1 | 2 | 7 | 0 | 1 | 5 | 0 |
Numbers in the table indicate the number of replicates demonstrating these effects. Syn = synergy, Add = Additive, Ind = Indifferent. No antagonism was observed for any of the cysteamine-antibiotic combinations. P. aeruginosa Pa14 is colistin resistant, P. aeruginosa Pa058 is ciprofloxacin resistant, P. aeruginosa 57388A is colistin and tobramycin resistant and P. aeruginosa 57388A is ciprofloxacin and tobramycin resistant. P. aeruginosa PAO1 is sensitive to all antibiotics tested.