Table 2.
The interaction of CHEO with gentamicin on MDR MSSA and MDR MRSA isolates by checkerboard titration method.
| Isolate No. | Compounds | MIC |
FIC | FIC index | Interaction | |
|---|---|---|---|---|---|---|
| Alone | Combination | |||||
| MSSA01 | CHEO | 12.0 ± 5.7 | 16.0 | 1.333 | 1.335 | Indifference |
| Gentamicin | 256.0 ± 0.0 | 0.5 | 0.002 | |||
| MSSA02 | CHEO | 16.0 ± 0.0 | 16.0 | 1.000 | 1.001 | Indifference |
| Gentamicin | 48.0 ± 22.6 | 0.063 | 0.001 | |||
| MRSA01 | CHEO | 32.0 ± 0.0 | 0.25 | 0.008 | 0.012 | Synergy |
| Gentamicin | 0.5 ± 0.0 | 0.002 | 0.004 | |||
| MRSA02 | CHEO | 32.0 ± 0.0 | 0.25 | 0.008 | 0.016 | Synergy |
| Gentamicin | 0.3 ± 0.0 | 0.002 | 0.008 | |||
| MRSA03 | CHEO | 16.0 ± 0.0 | 8.0 | 0.500 | 0.531 | Additive |
| Gentamicin | 64.0 ± 0.0 | 2.0 | 0.031 | |||
| MRSA04 | CHEO | 16.0 ± 0.0 | 8.0 | 0.500 | 0.625 | Additive |
| Gentamicin | 128.0 ± 0.0 | 16.0 | 0.125 | |||
| MRSA05 | CHEO | 8.0 ± 0.0 | 8.0 | 1.000 | 1.031 | Indifference |
| Gentamicin | 256.0 ± 0.0 | 8.0 | 0.031 | |||
Values are expressed by mean ± SD of triplicate experiments. MIC and FIC of CHEO are expressed in mg/mL whereas that of gentamicin is expressed in µg/mL.