Table 1.
MIC (μg/ml) and in vitro cytotoxicity of test and reference compounds
| E.coli | K.pneumoniae | P.aeruginosa | A.baumannii | Cytotox (HK-2 IC50 relative to PMB) | |||||
|---|---|---|---|---|---|---|---|---|---|
| Cpd | ATCC 25922 | IHMA 940398 | ATCC 4352 | IHMA 652780 | ATCC 27853 | IHMA 517175 | NCTC 13424 | IHMA 863866 | |
| 1 | 0.25 | 16 | 0.125 | 4.0 | 0.5 | 8.0 | 0.25 | 32 | 1 |
| 2a | 0.25 | 32 | 0.25 | 16 | 0.5 | 32 | 0.5 | >64 | 16.6 |
| 2b | 0.03 | 2.0 | 0.03 | 2.0 | 0.25 | 2.0 | 0.125 | 2.0 | 8.8 |
| 2c | 0.06 | 16 | 0.125 | 4.0 | 0.06 | 8.0 | 0.25 | >64 | 6.9 |
| 2d | 0.25 | 32 | 0.125 | ND | 0.125 | 8.0 | 0.125 | >64 | 12.0 |
| 3a | 0.5 | 4.0 | 0.5 | 0.5 | 0.5 | 2.0 | 0.5 | 4.0 | ND |
| 5a | 1.0 | 8.0 | 0.5 | 0.5 | 1.0 | 2.0 | 1.0 | 16 | 0.14 |
| 5b | 1.0 | 32 | 1.0 | ND | 1.0 | 32 | 2.0 | ND | 0.7 |
| 9a | 0.125 | 8.0 | 0.25 | 0.5 | 0.5 | 4.0 | 0.125 | 4.0 | 2.4 |
| 9b | 0.25 | 2.0 | 0.25 | 0.5 | 0.5 | 1.0 | 0.25 | 0.5 | 1.2 |
| 10 | 0.5 | 8.0 | 0.5 | 1.0 | 1.0 | 4.0 | 0.5 | 32 | ND |
| 13a | 0.5 | 8.0 | ND | 2.0 | 0.5 | 2.0 | 0.125 | 32 | ND |
| 13b | 0.25 | 16 | 0.06 | 4.0 | 0.25 | 4.0 | 0.125 | 64 | 5.2 |
| 13c | 0.125 | 32 | ND | 4.0 | 0.25 | 8.0 | 0.06 | 64 | 2.4 |
MICs determined by broth microdilution using cation-adjusted Mueller-Hinton broth (Oxoid, CM0405) according to CLSI guidelines.18 In vitro cytotoxicity was measured against the human kidney proximal tubule epithelial cell line (HK-2) and is presented as the ratio of the IC50 of test compound to that of polymyxin B19.