TABLE 3.
Concentration of AMA needed to restore the activity of different β-lactam antibiotics to the level seen with their EUCAST susceptibility breakpoint concentration in MBL-producing E. coli BW25113 ΔbamB ΔtolCa
| MBL | [AMA] at the susceptibility breakpoint of the antibiotic (μg/ml)b |
||
|---|---|---|---|
| Meropenem | Doripenem | Ampicillin | |
| NDM-1 | 8 | 12 | 32 |
| NDM-4 | 16 | 24 | >64 |
| NDM-5 | 16 | 24 | >64 |
| NDM-6 | 12 | 24 | >64 |
| VIM-2 | 8 | 8 | 24 |
| IMP-7 | 24 | 24 | >64 |
| CphA2 | 64 | >64 | ≤0.5 |
| AIM-1 | 64 | 64 | >64 |
a
All 8 MBL genes were cloned into the pGDP2 vector. All bioassays were conducted in duplicate. This table shows the results from replicate 1.
b
The EUCAST susceptibility breakpoint concentrations for meropenem, doripenem, and ampicillin are 2, 1 and 8 μg/ml, respectively.