TABLE 1.
Susceptibility profiles of C. freundii clinical isolates from the patient and after ceftazidime-avibactam passaging experiments
| Antimicrobial agent(s) | MIC (µg/ml) of isolatea
|
|||
|---|---|---|---|---|
| Initial isolate from patient (blaKPC-2 WT) |
Follow-up isolate (blaKPC-2-D179Y [11%]) |
Passaged on ceftazidime- avibactam at fixed concn of 4 µg/ml of inhibitor (blaKPC-2-D176Y [78%]) |
Passaged on ceftazidime- avibactam at 4:1 ratio (blaKPC-2-R164S + P174L [82%]) |
|
| Ceftazidime-avibactam | 4 | 64 | 32 | 64 |
| Ceftazidime | 512 | >512 | 512 | >512 |
| Ceftriaxone | >64 | >64 | >64 | >64 |
| Cefepime | >64 | >64 | >64 | 64 |
| Ampicillin-sulbactam | >32 | >32 | >32 | >32 |
| Piperacillin-tazobactam | >64 | >64 | >64 | >64 |
| Doripenem | >8 | >8 | >8 | >8 |
| Imipenem | 32 | 16 | 8 | 8 |
| Meropenem | 64 | 32 | 32 | 16 |
| Aztreonam | >16 | >16 | >16 | >16 |
| Doxycycline | 4 | 4 | 4 | 8 |
| Tetracycline | 8 | 8 | 8 | 8 |
| Ciprofloxacin | >4 | >4 | >4 | >4 |
| Levofloxacin | >4 | >4 | >4 | >4 |
| Trimethoprim-sulfamethoxazole | >4 | >4 | >4 | >4 |
| Colistin | 0.12 | 1 | 0.12 | ≤0.06 |
| Amikacin | 8 | 8 | 4 | 8 |
| Tobramycin | >8 | >8 | >8 | >8 |
a
The percentages of DNA sequence reads displaying mutations on blaKPC-2 leading to the alteration described are shown in brackets.