Validation of Sensititre Dry-Form Broth Microdilution Panels for Susceptibility Testing of Ceftazidime-Avibactam, a Broad-Spectrum-β-Lactamase Inhibitor Combination

Antimicrob Agents Chemother. 2015 Aug;59(8):5036-9. doi: 10.1128/AAC.00021-15. Epub 2015 May 26.


Ceftazidime-avibactam is a broad-spectrum-β-lactamase inhibitor combination in late-stage clinical development for the treatment of serious infections. In preparation for clinical microbiology laboratory use, a validation experiment was initiated to evaluate a commercial broth microdilution product (Sensititre dried MIC susceptibility system) compared to reference panels using 525 recent clinical isolates. Among 11 pathogen groups, all had Sensititre MIC/reference MIC ratios predominantly at 1 (47.5% to 97.5%), and automated and manual endpoint results did not differ. Enterobacteriaceae MIC comparisons showed a modest skewing of Sensititre MIC results toward an elevated MIC (33.9%), but the essential agreement was 98.9% with 100.0% reproducibility. In conclusion, Sensititre panels produced accurate ceftazidime-avibactam MIC results, allowing quality MIC guidance for therapy following regulatory approvals.

Publication types

  • Research Support, Non-U.S. Gov't
  • Validation Study

MeSH terms

  • Anti-Bacterial Agents / pharmacology*
  • Azabicyclo Compounds / pharmacology*
  • Ceftazidime / pharmacology*
  • Drug Combinations
  • Enterobacteriaceae / drug effects*
  • Enterobacteriaceae / isolation & purification
  • Enterobacteriaceae Infections / drug therapy
  • Gram-Positive Bacteria / drug effects*
  • Gram-Positive Bacteria / isolation & purification
  • Gram-Positive Bacterial Infections / drug therapy
  • Humans
  • Microbial Sensitivity Tests
  • Pseudomonas Infections / drug therapy
  • Pseudomonas aeruginosa / drug effects*
  • beta-Lactamase Inhibitors / pharmacology*


  • Anti-Bacterial Agents
  • Azabicyclo Compounds
  • Drug Combinations
  • avibactam, ceftazidime drug combination
  • beta-Lactamase Inhibitors
  • Ceftazidime