Table 2.
Minimum inhibitory concentration (MIC) of purified Ltnα, Ltnα–H23S and Ltnα–A27S alone, and in combination with equimolar concentrations of purified Ltnβ, against various Gram-positive organisms
| Peptide | L. lactis AM2 | S. aureus NCDO1499a | S. thermophilus NCDO2525 | S. aureus Newman | S. aureus Farm1 | E. casseliflavus 5053 | E. faecium 5119 | L. lactis HP |
|---|---|---|---|---|---|---|---|---|
| Ltnα + Ltnβ | 0.03125 | 0.500 | 0.03125 | 2.5 | 0.156 | 0.250 | 0.250 | 0.0156 |
| LtnαH23S + Ltnβ | 0.03125 | 0.250 | 0.03125 | 5.0 | 0.312 | 0.500 | 0.500 | 0.0313 |
| LtnαA27S + Ltnβ | 0.062 | ND | 0.0625 | ND | ND | ND | ND | ND |
| Ltnα | 0.937 | 1.875 | 0.937 | > 10 | 10 | > 3.75 | 3.75 | 0.937 |
| LtnαH23S | 0.468 | 1.875 | 0.937 | > 10 | > 10 | > 3.75 | > 3.75 | 1.875 |
| LtnαA27S | 1.874 | ND | 3.784 | ND | ND | ND | ND | ND |
a
Clinical mastitis isolate.
Values given are identical results from three independent determinations (μM). Those values in bold represent MICs that are improved relative to that of the wild-type against the relevant strain.
ND, not determined.