Table 1.
Antimicrobial susceptibility results by broth microdilution and gradient strips for KPC-producing E. coli isolates (Ec-1 and Ec-2), KPC-producing E. coli transformants (pKPC-3-TM and pKPC-49-TM), the isogenic E. coli DH5α strain, KPC-producing K. pneumoniae transformants (pKPC-3-TM and pKPC-49-TM), and the SHV-5-producing K. pneumoniae CSUB10R strain (ΔompK35; ΔompK36; ΔompK37).
| Broth Microdilution (mg/L) (Interpretation) | Gradient Strips (mg/L) (Interpretation) | |||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Antimicrobials | Ec-1 | Ec-2 |
E. coli pKPC-3-TM |
E. coli pKPC-49-TM |
E. coli DH5α |
K. pneumoniae pKPC-3-TM | K. pneumoniae pKPC-49-TM | K. pneumoniae CSUB10R |
E. coli pKPC-3-TM |
E. coli pKPC-49-TM |
E. coli DH5α |
K. pneumoniae pKPC-3-TM | K. pneumoniae pKPC-49-TM | K. pneumoniae CSUB10R |
| Piperacillin-tazobactam | >64/4 (R) | 16/4 (I) | ≤4/4 (S) | ≤4/4 (S) | ≤4/4 (S) | >64/4 (R) | >64/4 (R) | >64/4 (R) | - | - | - | - | - | - |
| Ceftazidime | >32 (R) | >32 (R) | 1 (S) | 2 (I) | ≤0.25 (S) | >32 (R) | >32 (R) | >32 (R) | 0.25 (S) | 1 (S) | 0.19 (S) | >256 (R) | >256 (R) | >256 (R) |
| Cefotaxime | >32 (R) | >32 (R) | ≤0.25 (S) | ≤0.25 (S) | ≤0.25 (S) | >32 (R) | >32 (R) | >32 (R) | 0.032 (S) | 0.047 (S) | 0.032 (S) | >256 (R) | >256 (R) | >256 (R) |
| Cefepime | >64 (R) | 64 (R) | ≤0.125 (S) | 0.25 (S) | ≤0.125 (S) | >64 (R) | >64 (R) | 64 (R) | 0.047 (S) | 0.047 (S) | 0.023 (S) | >256 (R) | >256 (R) | 32 (R) |
| Aztreonam | >32 (R) | >32 (R) | 4 (I) | ≤0.5 (S) | ≤0.5 (S) | >32 (R) | >32 (R) | >32 (R) | - | - | - | - | - | - |
| Ceftazidime-avibactam | 0.5/4 (S) | 16/4 (R) | ≤0.125/4 (S) | ≤0.125/4 (S) | ≤0.125/4 (S) | 4/4 (S) | 4/4 (S) | 2/4 (S) | 0.047/4 (S) | 0.094/4 (S) | 0.094/4 (S) | 2/4 (S) | 12/4 (R) | 2/4 (S) |
| Imipenem | 4 (I) | 2 (S) | 0.5 (S) | ≤0.25 (S) | ≤0.25 (S) | >16 (R) | >16 (R) | 2 (S) | 0.25 (S) | 0.25 (S) | 0.38 (S) | >32 (R) | 4 (I) | 0.75 (S) |
| Meropenem | 8 (I) | 0.5 (S) | ≤0.125 (S) | ≤0.125 (S) | ≤0.125 (S) | 16 (R) | 8 (I) | 2 (S) | 0.023 (S) | 0.023 (S) | 0.032 (S) | 6 (I) | 2 (S) | 2 (S) |
| Gentamicin | >8 (R) | >8 (R) | ≤8 (S) | ≤8 (S) | ≤8 (S) | ≤8 (S) | ≤8 (S) | ≤8 (S) | - | - | - | - | - | - |
| Amikacin | ≤8 (S) | ≤8 (S) | ≤8 (S) | ≤8 (S) | ≤8 (S) | ≤8 (S) | ≤8 (S) | ≤8 (S) | - | - | - | - | - | - |
| Tobramycin | >8 (R) | >8 (R) | ≤8 (S) | ≤8 (S) | ≤8 (S) | ≤8 (S) | ≤8 (S) | ≤8 (S) | - | - | - | - | - | - |
| Ciprofloxacin | >2 (R) | >2 (R) | ≤2 (S) | ≤2 (S) | ≤2 (S) | >2 (R) | >2 (R) | >2 (R) | - | - | - | - | - | - |
| Tigecycline | ≤0.5 (S) | ≤0.5 (S) | ≤0.5 (S) | ≤0.5 (S) | ≤0.5 (S) | ≤0.5 (S) | ≤0.5 (S) | ≤0.5 (S) | - | - | - | - | - | - |
| Colistin | ≤2 (S) | ≤2 (S) | ≤2 (S) | ≤2 (S) | ≤2 (S) | ≤2 (S) | ≤2 (S) | ≤2 (S) | - | - | - | - | - | - |
| Fosfomycin | ≤32 (S) | ≤32 (S) | ≤32 (S) | ≤32 (S) | ≤32 (S) | >32 (S) | >32 (S) | >32 (S) | - | - | - | - | - | - |