Table 1.
Characteristics of KPC-4- and KPC-5-producing K. pneumoniae strains and their E. coli DH10B transformants
| Isolatea | β-Lactamase(s) | MIC (μg/ml)b |
||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| IMP | MER | ERT | DOR | CAZ | CTX | CEF | ATM | TIC-CLAV | PIP-TAZ | AMI | TOB | DOX | CIP | LEV | SXT | TGC | COL | PLB | ||
| BK31551 | TEM-1, SHV-11, KPC-4 | 2 | 0.5 | 1 | 1 | >16 | >32 | 4 | >16 | 128/2 | 64/4 | ≤4 | ≤1 | >16 | 1 | 2 | >4/76 | 1 | 0.5 | 1 |
| T-BK31551 | TEM-1, KPC-4 | 1 | 0.5 | 0.5 | 0.5 | >16 | 16 | 8 | >16 | >128/2 | >64/4 | ≤4 | 4 | ≤2 | ≤0.25 | ≤1 | >4/76 | ≤0.25 | ≤0.25 | 0.5 |
| BK31572 | TEM-1, SHV-11, KPC-4 | 4 | 1 | 4 | 2 | >16 | >32 | 4 | >16 | >128/2 | >64/4 | ≤4 | ≤1 | ≤2 | ≤0.25 | ≤1 | >4/76 | ≤0.25 | 0.5 | 1 |
| T-BK31572 | TEM-1, KPC-4 | 2 | 1 | 1 | 0.5 | >16 | >32 | 8 | >16 | >128/2 | 64/4 | ≤4 | 2 | 2 | ≤0.25 | ≤1 | >4/76 | ≤0.25 | ≤0.25 | 0.5 |
| BK31567 | SHV-1, KPC-5 | 2 | 1 | 4 | 0.5 | >16 | 32 | ≤2 | >16 | >128/2 | >64/4 | ≤4 | ≤1 | 4 | >2 | ≤1 | >4/76 | 1 | 0.5 | 1 |
| T-BK31567 | KPC-5 | 1 | 0.5 | 0.5 | 0.5 | >16 | 4 | ≤2 | >16 | >128/2 | 16/4 | ≤4 | ≤1 | ≤2 | ≤0.25 | ≤1 | >4/76 | ≤0.25 | ≤0.25 | 0.5 |
T-, E. coli DH10B transformant.
MICs were determined using broth microdilution; resistance is indicated in boldface. IMP, imipenem; MER, meropenem; ERT, ertapenem; DOR, doripenem; CAZ, ceftazidime; CTX, cefotaxime; CEF, cefepime; ATM, aztreonam; TIC-CLAV, ticarcillin-clavulanate; PIP-TAZ, piperacillin-tazobactam; AMI, amikacin; TOB, tobramycin; DOX, doxycycline; CIP, ciprofloxacin; LEV, levofloxacin; SXT, trimethoprim-sulfamethoxazole; TGC, tigecycline; COL, colistin; PLB, polymyxin B. The 2012 CLSI breakpoints were used to interpret the MIC results for carbapenem-susceptible (S), -intermediate (I), and -resistant (R) isolates, as follows (S/I/R): imipenem, ≤1/2/≥4 μg/ml; meropenem, ≤1/2/≥4 μg/ml; ertapenem, ≤0.5/1/≥2 μg/ml; and doripenem ≤1/2/≥4 μg/ml (25).