Table 2.
Antibacterial activities of melittin and its analogs against Gram-positive and Gram-negative bacteria.
| Microorganism | MIC (μM) | |||||
|---|---|---|---|---|---|---|
| Melittin | Mel-LX1 | Mel-LX2 | Mel-LX3 | Mel-LX4 | Mel-LX5 | |
| Gram-positive organisms | ||||||
| S. aureus (KCTC 1621) | 8 | 64 | 32 | 8 | 32 | >128 |
| S. epidermidis (KCTC 1917) | 8 | 32 | 32 | 16 | 32 | >64 |
| B. subtilis (KCTC 3068) | 16 | 16 | 16 | 16 | 32 | >64 |
| MRSA (CCARM 3090) | 4 | >128 | 128 | 4 | 128 | >128 |
| Gram-negative organisms | ||||||
| E. coli (KCTC 1682) | 8 | 64 | 32 | 16 | 32 | >128 |
| P. aeruginosa (KCTC 1637) | 16 | 64 | 64 | 16 | 64 | >64 |
| S. typhimurium (KCTC 1926) | 16 | 32 | 16 | 16 | 32 | >64 |
| MDRPA (CCARM 2095) | 8 | >128 | 128 | 8 | 128 | >128 |
| GM (μM) a | 10.5 | 98 | 56 | 12.5 | 60 | 192 |
| HC10 (μM) b | 2 | 64 | 128 | 64 | 128 | 128 |
| TI (HC10/GM) c | 0.19 | 0.65 | 2.28 | 5.12 | 2.13 | 0.66 |
a Geometric mean (GM) of the minimum inhibitory concentration (MIC). b HC10 is the minimum inhibitory concentration that causes 10% hemolysis of sRBC. c Therapeutic index (TI) is the ratio of HC10/GM.