TABLE 4.
In vitro activity of ceftazidime-avibactam and comparative agents against ceftazidime-nonsusceptible Gram-negative isolates for all randomized patientsa
| Baseline pathogen and agent (no. of pathogens tested) | MIC (mg/liter) |
||
|---|---|---|---|
| Range | MIC50 | MIC90 | |
| All Enterobacteriaceae (109) | |||
| Ceftazidime-avibactam | ≤0.008 to >256 | 0.25 | 2 |
| Ceftazidime | 8 to >64 | 32 | >64 |
| Amikacin | 0.5 to >64 | 4 | >64 |
| Aztreonam | 0.12 to >64 | 64 | >64 |
| Cefepime | 0.06 to >16 | >16 | >16 |
| Ceftaroline | 0.25 to >256 | >256 | >256 |
| Ceftriaxone | 1 to >32 | >32 | >32 |
| Gentamicin | ≤0.12 to >16 | >16 | >16 |
| Imipenem | 0.06 to 16 | 0.12 | 2 |
| Levofloxacin | 0.03 to >8 | >8 | >8 |
| Meropenem | 0.015 to >8 | 0.03 | 0.5 |
| Piperacillin-tazobactam | 0.25 to >128 | 16 | >128 |
| Tigecycline | 0.12 to 8 | 0.5 | 2 |
| Trimethoprim-sulfamethoxazole | ≤0.25 to >8 | >8 | >8 |
| Enterobacter cloacae (10) | |||
| Ceftazidime-avibactam | 0.25 to >256 | 1 | >256 |
| Ceftazidime | 16 to >64 | >64 | >64 |
| Amikacin | 2 to >64 | 4 | 16 |
| Aztreonam | 8 to >64 | >64 | >64 |
| Cefepime | 2 to >16 | >16 | >16 |
| Ceftaroline | 32 to >256 | >256 | >256 |
| Ceftriaxone | 32 to >32 | >32 | >32 |
| Gentamicin | 0.25 to >16 | >16 | >16 |
| Imipenem | 0.25 to 8 | 0.5 | 8 |
| Levofloxacin | 0.5 to >8 | 8 | >8 |
| Meropenem | 0.03 to >8 | 0.06 | 8 |
| Piperacillin-tazobactam | 4 to >128 | 64 | >128 |
| Tigecycline | 0.5 to 8 | 0.5 | 4 |
| Trimethoprim-sulfamethoxazole | ≤0.25 to >8 | >8 | >8 |
| Escherichia coli (59) | |||
| Ceftazidime-avibactam | ≤0.008 to 4 | 0.12 | 2 |
| Ceftazidime | 8 to >64 | 32 | >64 |
| Amikacin | 0.5 to >64 | 4 | 8 |
| Aztreonam | 8 to >64 | 64 | >64 |
| Cefepime | 0.06 to >16 | >16 | >16 |
| Ceftaroline | 0.25 to >256 | >256 | >256 |
| Ceftriaxone | 1 to >32 | >32 | >32 |
| Gentamicin | 0.25 to >16 | 2 | >16 |
| Imipenem | 0.06 to 0.5 | 0.12 | 0.25 |
| Levofloxacin | 0.03 to >8 | >8 | >8 |
| Meropenem | 0.015 to 0.5 | 0.015 | 0.03 |
| Piperacillin-tazobactam | 1 to >128 | 8 | >128 |
| Tigecycline | 0.12 to 1 | 0.25 | 0.5 |
| Trimethoprim-sulfamethoxazole | ≤0.25 to >8 | >8 | >8 |
| Klebsiella pneumoniae (27) | |||
| Ceftazidime-avibactam | 0.12 to >256 | 0.5 | 2 |
| Ceftazidime | 8 to >64 | >64 | >64 |
| Amikacin | 0.5 to >64 | 2 | >64 |
| Aztreonam | 2 to >64 | >64 | >64 |
| Cefepime | 0.25 to >16 | >16 | >16 |
| Ceftaroline | 8 to >256 | >256 | >256 |
| Ceftriaxone | 8 to >32 | >32 | >32 |
| Gentamicin | ≤0.12 to >16 | >16 | >16 |
| Imipenem | 0.12 to 16 | 0.12 | 8 |
| Levofloxacin | 0.06 to >8 | >8 | >8 |
| Meropenem | 0.015 to >8 | 0.03 | 8 |
| Piperacillin-tazobactam | 4 to >128 | 128 | >128 |
| Tigecycline | 0.5 to 4 | 1 | 4 |
| Trimethoprim-sulfamethoxazole | ≤0.25 to >8 | >8 | >8 |
| Pseudomonas aeruginosa (6) | |||
| Ceftazidime-avibactam | 8 to 32 | NA | NA |
| Ceftazidime | 32 to >64 | NA | NA |
| Amikacin | 8 to >64 | NA | NA |
| Cefepime | 16 to >16 | NA | NA |
| Ceftriaxone | >32 to >32 | NA | NA |
| Ciprofloxacin | >4 to >4 | NA | NA |
| Gentamicin | 2 to >16 | NA | NA |
| Imipenem | 1 to 16 | NA | NA |
| Levofloxacin | >8 to >8 | NA | NA |
| Meropenem | 2 to >8 | NA | NA |
| Piperacillin-tazobactam | 32 to >128 | NA | NA |
Total of 1,066 randomized patients. NA, not applicable (MIC50 and MIC90 were not calculated for pathogens identified in <10 patients). Data are provided for pathogens identified in at least 10 patients, with the exception of Pseudomonas aeruginosa, n = 6; ceftazidime-avibactam MIC values for other pathogens are as follows: Citrobacter freundii complex (n = 3), MIC range, 0.25 to 0.5 mg/liter; Enterobacter aerogenes (n = 1), MIC, 2 mg/liter, Proteus mirabilis (n = 5), MIC range, 0.015 to 2 mg/liter; other Enterobacteriaceae (n = 4), MIC range, 0.03 to 0.12 mg/liter; Alcaligenes faecalis (n = 3), MIC range, 4 to 4 mg/liter; and Comamonas testosteroni (n = 1), MIC, >256 mg/liter. A patient could have more than one pathogen isolated. Multiple isolates of the same species from the same patient were counted only once using the isolate with the highest MIC to the study drug received. For bacteremic patients, multiple isolates of the same species from the same patient were counted only once using the isolate with the highest MIC to the study drug received across culture source (intra-abdominal site or blood).