Activity of ceftolozane/tazobactam, imipenem/relebactam and ceftazidime/avibactam against clinical Gram-negative isolates—SMART United States 2019–21
Why this work is in the frame
A frame that forgets how it found something cannot be audited. These are the routes that admitted this work.
Bibliographic record
Abstract
Abstract Background Ongoing national and international surveillance efforts are critical components of antimicrobial stewardship, resistance monitoring, and drug development programs. In this report, we summarize the results of ceftolozane/tazobactam, imipenem/relebactam, ceftazidime/avibactam and comparator agent testing against 10 509 Enterobacterales and 2524 Pseudomonas aeruginosa collected by USA clinical laboratories in 2019–21 as part of the SMART global surveillance programme. Methods MICs were determined by CLSI broth microdilution and interpreted using 2023 CLSI M100 breakpoints. Results Most Enterobacterales were ceftazidime/avibactam susceptible (>99%), meropenem susceptible (99%) and ceftolozane/tazobactam susceptible (94%). Non-Morganellaceae Enterobacterales were also highly susceptible to imipenem/relebactam (99%). Ceftolozane/tazobactam inhibited 94% of Escherichia coli and 89% of Klebsiella pneumoniae with ceftriaxone non-susceptible/non-carbapenem-resistant phenotypes. Against P. aeruginosa, ceftolozane/tazobactam (97% susceptible) was more active than ceftazidime/avibactam (95%) and imipenem/relebactam (91%). MDR and difficult-to-treat resistance (DTR) phenotypes were identified in 13% and 7% of P. aeruginosa isolates, respectively. Ceftolozane/tazobactam remained active against 78% of MDR P. aeruginosa (13% and 23% higher than ceftazidime/avibactam and imipenem/relebactam, respectively) and against 74% of DTR P. aeruginosa (24% and 37% higher than ceftazidime/avibactam and imipenem/relebactam, respectively). Length of hospital stay at the time of specimen collection, ward type and infection type resulted in percent susceptible value differences of >5% across isolate demographic strata for some antimicrobial agent/pathogen combinations. Conclusions We conclude that in the USA, in 2019–21, carbapenem (meropenem) resistance remained uncommon in Enterobacterales and ceftolozane/tazobactam was more active than both ceftazidime/avibactam and imipenem/relebactam against P. aeruginosa.
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Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.001 | 0.001 |
| Meta-epidemiology (narrow) | 0.001 | 0.001 |
| Meta-epidemiology (broad) | 0.001 | 0.000 |
| Bibliometrics | 0.000 | 0.001 |
| Science and technology studies | 0.000 | 0.001 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.001 | 0.000 |
| Research integrity | 0.001 | 0.000 |
| Insufficient payload (model declined to judge) | 0.000 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from it