TABLE 3.
Isoelectric points and susceptibilities of AmpC-producing isolates of K. pneumoniae
| Strain | Hospital site | PFGE type | pIa | MIC (μg/ml) ofb:
|
||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| AMP | CAZ | CAZ/CLA | CRO | ATM | FEP | FOX | PIP | PIP/TZB | CIP | LVX | IMP | ERT | ||||
| MCV-4 | 123 | B1 | 9.0, 5.4 | >4,096 | 64 | 64 | 32 | 32 | 0.13 | 1,024 | 128 | 64 | 0.06 | 0.13 | 0.5 | 0.5 |
| MCV-80G | 123 | H1 | 9.0, 5.4, 7.6 | >4,096 | 64 | 64 | 8 | 32 | 0.13 | 512 | >1,024 | 32 | 0.06 | 0.06 | 0.5 | 0.5 |
| MCV-63 | 123 | C1 | 7.2, 5.6, 7.6 | 4,096 | 128 | 32 | 8 | 4 | 0.5 | 512 | 1,024 | 32 | 8 | 8 | 0.5 | 0.13 |
| MCV-29 | 155 | O1 | 7.3, 5.8 | >4,096 | 128 | 64 | 8 | 16 | 0.5 | 256 | 1,024 | 64 | 32 | 32 | 0.03 | 0.06 |
| MCV-30 | 155 | P1 | 7.3, 5.6 | >4,096 | 64 | 32 | 8 | 4 | 1 | 256 | 128 | 64 | 0.5 | 1 | 0.03 | 0.03 |
a
The first isoelectric point listed for each isolate corresponds to the cloxacillin-inhibited band (AmpC); additional pIs correspond to CLA-inhibited bands.
b
Abbreviations: AMP, ampicillin; CAZ, ceftazidime; CLA, clavulanic acid (4 μg/ml); CRO, ceftriaxone; ATM, aztreonam; FEP, cefepime; FOX, cefoxitin; PIP, piperacillin; TZB, tazobactam (4 μg/ml); CIP, ciprofloxacin; LVX, levofloxacin; IMP, imipenem; ERT, ertapenem.