Table 3. MIC values of antibiotics and chitosan (2.6 kDa) in a checkerboard assay against S. aureus ATCC 29213.
| Antibiotics (ATB) in the checkerboard assay | ATB MIC alone (μg/ml) |
ATB MIC with chitosan (μg/ml) |
Chitosan MIC alone (mg/ml) |
Chitosan MIC with ATB (mg/ml) | ∑FIC value | Resulta |
|---|---|---|---|---|---|---|
| Gentamicin | 0.5 | 0.06 | 1 | 0.5 | 0.62 | I |
| Erythromycin | 0.5 | 0.12 | 1 | 0.25 | 0.49 | S |
| Vancomycin | 1 | 0.5 | 1 | 0.5 | 1.00 | I |
| Chloramphenicol | 4 | 2 | 1 | 0.5 | 1.00 | I |
| Ciprofloxacin | 0.25 | 0.01 | 1 | 0.5 | 0.54 | BSb |
| Ceftiofur | 0.5 | 0.5 | 1 | 0.5 | 1.50 | I |
| Rifampicin | 0.0025 | 0.0012 | 1 | 0.25 | 0.73 | I |
| Pirlimycin | 0.25 | 0.06 | 1 | 0.5 | 0.74 | I |
| Oxacillin | 0.12 | 0.12 | 1 | 0.5 | 1.50 | I |
a I, indifferent, S, synergy.
b borderline synergy.