254In Vitro Activity of Ceftazidime in Combination with Avibactam vs 1825 Pseudomonas aeruginosa Clinical Isolates Obtained from across Canada as Part of the CANWARD Study, 2009-2013
Bibliographic record
Abstract
Background. Avibactam is a non-beta lactam beta-lactamase inhibitor, with activity against molecular class A, class C, and some class D beta-lactamase enzymes. The purpose of this study was to evaluate the in vitro activity of ceftazidime in combination with avibactam against a large collection of Pseudomonas aeruginosa clinical isolates obtained as part of the CANWARD study (2009-2013). Methods. From January 2009 to December 2013, inclusive, 12 to 15 sentinel hospitals across Canada submitted clinical isolates from patients attending ERs, medical and surgical wards, hospital clinics, and ICUs (CANWARD). Each center was asked to submit clinical isolates (consecutive, one per patient/infection site) from blood (100 to 165), respiratory (100), urine (25 to 50), and wound (25 to 50) infections. Susceptibility testing was performed using broth microdilution as described by CLSI. Doubling concentrations of ceftazidime were evaluated in combination with a fixed concentration of avibactam (4 µg/mL). Results. 1825 P. aeruginosa clinical isolates were obtained as a part of CANWARD. The antimicrobial susceptibility profile of these isolates is presented in the table. Two-hundred and fifty-seven isolates (14% of the total) were multidrug-resistant (non-susceptible to at least one antimicrobial from 3 or more classes). Ceftazidime-avibactam demonstrated an MIC of ≤8 µg/mL (ceftazidime susceptibility breakpoint) vs 70.4% of MDR isolates. Further, 67.4% of ceftazidime non-susceptible isolates and 79.9% of meropenem non-susceptible isolates had an MIC of ≤8 µg/mL for ceftazidime-avibactam. Conclusion. The combination of ceftazidime-avibactam demonstrated improved in vitro activity over ceftazidime alone vs P. aeruginosa clinical isolates obtained from patients across Canada (4-fold reduction in MIC90). Over two-thirds of MDR isolates evaluated were inhibited by ≤8 µg/mL of ceftazidime-avibactam. Disclosures. D. Hoban, Abbot: Research relationship, Research support; Astellas Pharma Canada: Research relationship, Research support; AstraZeneca: Research relationship, Research support; Cubist Pharmaceuticals: Research relationship, Research support; Merck Canada Inc.: Research relationship, Research support; Optimer: Research relationship, Research support; Pfizer: Research relationship, Research support; Sunovion: Research relationship, Research support; The Medicines Company: Research relationship, Research support; Theravance: Research relationship, Research support; Triton Pharma: Research relationship, Research support; Trius: Research relationship, Research support G. Zhanel, Abbot: Research relationship, Research support; Astellas Pharma Canada: Research relationship, Research support; AstraZeneca: Research relationship, Research support; Cubist Pharmaceuticals: Research relationship, Research support Merck Canada Inc.: Research relationship, Research support; Optimer: Research relationship, Research support; Pfizer: Research relationship, Research support; Sunovion: Research relationship, Research support; The Medicines Company: Research relationship, Research support; Theravance: Research relationship, Research support; Triton Pharma: Research relationship, Research support; Trius: Research relationship, Research support
Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.
How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.001 | 0.001 |
| Meta-epidemiology (narrow) | 0.001 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 0.000 |
| Bibliometrics | 0.001 | 0.002 |
| Science and technology studies | 0.001 | 0.001 |
| Scholarly communication | 0.001 | 0.000 |
| Open science | 0.000 | 0.001 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.001 | 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 itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".