TABLE 5.
AI-1 potentiation of antibiotic activity in A. baylyi mutantsa
| Strain | Genotype | Vancomycin MIC (μM AI-1) |
Clarithromycin MIC (μM AI-1) |
||||||
|---|---|---|---|---|---|---|---|---|---|
| 0 | 15 | 20 | ΔMIC | 0 | 15 | 20 | ΔMIC | ||
| MAY116 | Wild type | 256 | 16 | 16 | 8 | 0.5 | 16 | ||
| MAY156 | ΔlptE | 2 | 0.5 | 4 | 0.25 | 0.125 | 2 | ||
| MAY157 | ΔlpxL | 128 | 24 ± 9 | 5.3 | 8 | 0.5 | 16 | ||
| MAY158 | ΔlpxM | 28 ± 5 | 16 | 1.8 | 4 | 0.5 | 8 | ||
| MAY154 | ΔmlaBCDEF ΔpldA | 128 | 53 ± 18 | 2.4 | 2 | 0.5 | 4 | ||
| MAY155 | ΔmlaBCDEF ΔpldA ΔlpxA | 4 | 4 | 1 | 0.0625 | 0.0625 | 1 | ||
a
Values represent means of two to three broth microdilution assays in LB at 45 to 48 h with nonzero sample standard deviations shown. The MIC of AI-1 alone was ≥50 μM for all strains (not shown). MAY116 and MAY154 carry nptII in place of an IS element (see Materials and Methods).