Table 2. Antimicrobial drug susceptibilities of the isolates from study of New Delhi metallo-β-lactamase in Klebsiella pneumoniae and Escherichia coli, Canada, 2010*.
| Test/antimicrobial agent | K. pneumoniae N10–0469 | E. coli DH10B (pNDM-Kp10469) | E. coli N10–0505 | E. coli DH10B (pNDM-Ec10505) | E. coli DH10B |
|---|---|---|---|---|---|
| Broth microdilution (MIC, μg/mL) | |||||
| Amoxicillin/clavulanic acid | >32 | >32 | 32 | >32 | 4 |
| Piercillin/tazobactam | >64 | >64 | >64 | >64 | <4 |
| Ampicillin | >16 | >16 | >16 | >16 | 2 |
| Cefazolin | >16 | >16 | >16 | >16 | <8 |
| Cefotaxime | >64 | >64 | >64 | >64 | <0.25 |
| Cefotaxime/clavulanic acid | >64 | >64 | >64 | >64 | <0.12 |
| Ceftazidime | >128 | >128 | >128 | >128 | <0.25 |
| Ceftazidime/clavulanic acid | >128 | >128 | >128 | >128 | 0.25 |
| Cefepime | >16 | 16 | >16 | 16 | <1 |
| Cefoxitin | >64 | >64 | >64 | >64 | 8 |
| Imipenem | >16 | 4 | 2 | 2 | <0.5 |
| Meropenem | >8 | 2 | 8 | 2 | <1 |
| Chloramphenicol | 16 | 4 | 32 | 4 | <2 |
| Tetracycline | >32 | ≤4 | 32 | ≤4 | <4 |
| Amikacin | >64 | >64 | >64 | >64 | 2 |
| Gentamicin | >16 | >16 | >16 | >16 | <0.25 |
| Ciprofloxacin | >2 | <0.015 | >2 | <0.015 | <0.015 |
| Trimethoprim/sulfamethoxazole |
>4 |
<0.12 |
>4 |
<0.12 |
<0.12 |
| Etest (MIC, μg/mL) | |||||
| Aztreonam | >256 | 4 | >256 | 4 | 0.094 |
| Imipenem | >32 | 4 | >32 | 4 | 0.19 |
| Meropenem | >32 | 8 | 32 | 6 | 0.032 |
| Ertapenem | >32 | 16 | >32 | 16 | 0.008 |
| Colistin | 0.38 | ND | 0.38 | ND | ND |
| Polymyxin B | 0.19 | ND | 0.25 | ND | ND |
| Tigecycline |
1.5 |
ND |
0.125 |
ND |
ND |
| Disk diffusion (zone diameter, mm) | |||||
| Imipenem | 6 | 14 | 11 | 13 | 33 |
| Meropenem | 6 | 15 | 10 | 14 | 35 |
| Ertapenem | 6 | 13 | 6 | 13 | 35 |
*NDM, New Delhi metallo-β-lactamase; ND, not done.