Table 2.
Antibacterial Activity against 7 Strains of A. baumannii Resistant to Polymyxin B and Colistin and 20 Worldwide 2016 and 2017 Isolates Resistant to 18 Classical Antibiotics
| peptide namea | peptide mass | MICGM (μM)b | MICGM (μM)c |
|---|---|---|---|
| With Specificity Determinants | |||
| D87(Lys1-6 Arg-1) | 3033.7 | 0.8 | nd |
| D84(Lys1-6 Lys-1) | 2865.6 | 0.5 | 0.7 |
| D85(Lys1-6 Orn-1) | 2781.5 | 0.5 | nd |
| D86(Lys1-6 Dab-1) | 2697.3 | 1.0 | 1.0 |
| D105(Lys1-6 Dap-1) | 2613.1 | 1.2 | 1.0 |
| D101(Lys1Ser26-5 Lys-1) | 2824.5 | 0.8 | 1.0 |
| D102(Lys1Ser26-5 Dab-1) | 2684.3 | 0.7 | 0.6 |
| Without Specificity Determinants | |||
| D85(K13A/K16A)-(Lys1-6 Orn-1) | 2667.3 | 2.0 | 1.9 |
| D86(K13A/K16A)-(Lys1-6 Dab-1) | 2583.1 | 0.9 | 0.9 |
| D105(K13A/K16A)-(Lys1-6 Dap-1) | 2499.0 | 1.3 | 2.0 |
| Colistin | 1155.5 | >28 | nd |
| Polymyxin B | 1301.6 | >25 | nd |
6 Lys-1 denotes 6 Lys residues on the polar face at positions 3,7, 11, 18, 22, and 26; 5 Lys-1 denotes 5 Lys residues on polar face at positions 3, 7, 11, 18, and 22 (position 26 is substituted by Ser).
MIC is minimal inhibitory concentration (μM) that inhibited growth of different strains in MH medium at 37 °C after 24 h, with the MIC based on three sets of replicates; MICGM is the geometric mean of the MIC values from seven different strains of A. baumanii resistant to polymyxin B and colistin, antibiotics of last resort.
MICGM is the geometric mean of the MIC values for 20 worldwide 2016 and 2017 isolates resistant to 18 classical antibiotics.