Table 2 Antimicrobial susceptibility testing of blaNDM-positive clinical strains and E. coli strains harboring natural and recombinant blaNDM-carrying plasmids
Strain | MIC of different β-lactam antibiotics for blaNDM variants (μg/mL) | |||||
|---|---|---|---|---|---|---|
Meropenem | Imipenem | Aztreonam | Ticarcillin | Ceftazidime | Ceftiofur | |
Original bacteria | ||||||
YZLc5-3 | 256 | 256 | 256 | 512 | > 512 | > 512 |
YZLc1-3 | > 512 | > 512 | 512 | 512 | > 512 | > 512 |
YZMc3-1 | 512 | 512 | 512 | > 152 | > 512 | > 512 |
YZLc23-1 | > 512 | 512 | 256 | 512 | > 512 | > 512 |
YZLc4-1 | > 512 | > 512 | 256 | > 512 | > 512 | > 512 |
Transconjugants | ||||||
E. coli C600 | ≤ 0.125 | ≤ 0.125 | ≤ 0.125 | 4 | 2 | 1 |
C600 + NDM-5 | 256 | 128 | ≤ 0.125 | 512 | 256 | > 512 |
C600 + NDM-9 | 256 | 256 | 0.5 | > 152 | > 512 | 512 |
C600 + NDM-13 | 256 | 256 | 1 | 512 | 512 | > 512 |
C600 + NDM-27 | 512 | 256 | 1 | > 512 | 512 | 512 |
Transformants | ||||||
BL21 + pET28a | ≤ 0.125 | ≤ 0.125 | ≤ 0.125 | 1 | 0.5 | ≤ 0.125 |
BL21 + pET28a_NDM-1 | 2 | 1 | 0.25 | 4 | 4 | 4 |
BL21 + pET28a_NDM-5 | 4 | 2 | ≤ 0.125 | 8 | 4 | 4 |
BL21 + pET28a_NDM-9 | 2 | 2 | 0.25 | 4 | 4 | 8 |
BL21 + pET28a_NDM-13 | 4 | 2 | 0.5 | 8 | 8 | 8 |
BL21 + pET28a_NDM-27 | 8 | 4 | 0.5 | 8 | 8 | 8 |