TABLE 2.
MICs (μg/ml) of indicated P. aeruginosa strains.
| strains | Imipenem (μg/ml)a | Ampicillin (μg/ml) | Meropenem (μg/ml)a | Biapenem (μg/ml)b |
| ISP50 | 0.3125 | ND | 3.125 | 0.78125 |
| IRP41 | 10 | ND | 6.25 | 6.25 |
| ISP50/pUCP24 | 0.3125 | ND | 3.125 | 0.78125 |
| IRP41/pUCP24 | 10 | ND | 6.25 | 6.25 |
| IRP41/pUCP24-oprDISP50 | 0.625 | ND | 3.125 | 3.125 |
| IRP41/pUCP24-oprDIRP41 | 10 | ND | 6.25 | 6.25 |
| IRP41/pUCP24-ldcAISP50 | 5 | ND | 3.125 | 3.125 |
| IRP41/pUCP24-ldcAIRP41 | 10 | ND | 6.25 | 6.25 |
| PAO1 | 1.5625 | 625 | 3.125 | 1.5625 |
| PAO1ΔldcA | 0.78125 | 1250 | 1.5625 | 0.78125 |
| PA14 | 1.5625 | 312.5 | 1.5625 | 1.5625 |
| PA14ΔldcA | 0.78125 | 1250 | 0.3906 | 0.3906 |
ND, not determined; aClinical Laboratory Standards Institute (CLSI) susceptibility breakpoints: imipenem, meropenem ≤ 2 μg/ml, resistance breakpoints: imipenem, meropenem ≥ 8 μg/ml. b no CLSI breakpoint concentrations for biapenem have been established, but previous studies suggested that MIC ≤ 4 μg/ml is sensitive and MIC ≥ 16 μg/ml is resistant (Hoban et al., 1993; Hang et al., 2018).