Susceptibility Provision Enhances Effective De-escalation (SPEED): Utilizing rapid phenotypic susceptibility testing in Gram-negative bloodstream infections and its potential clinical impact

Jack G. Schneider, James B. Wood, Bryan H. Schmitt, Christopher L. Emery, Thomas E. Davis, Nathan W. Smith, Sarah Blevins, Jon Hiles, Armisha Desai, Justin Wrin, Brittany Bocian, John J. Manaloor

Research output: Contribution to journalArticle

3 Scopus citations


Objectives: We evaluated the performance and time to result for pathogen identification (ID) and antimicrobial susceptibility testing (AST) of the Accelerate Pheno™ system (AXDX) compared with standard of care (SOC) methods. We also assessed the hypothetical improvement in antibiotic utilization if AXDX had been implemented. Methods: Clinical samples from patients with monomicrobial Gram-negative bacteraemia were tested and compared between AXDX and the SOC methods of the VERIGENEV® and Bruker MALDI BiotyperV® systems for ID and the VITEKV® 2 system for AST. Additionally, charts were reviewed to calculate theoretical times to antibiotic de-escalation, escalation and active and optimal therapy Results: ID mean time was 21 h for MALDI-TOF MS, 4.4 h for VERIGENEV® and 3.7 h for AXDX. AST mean time was 35 h for VITEKV® 2 and 9.0 h for AXDX. For ID, positive percentage agreement was 95.9% and negative percentage agreement was 99.9%. For AST, essential agreement was 94.5% and categorical agreement was 93.5%. If AXDX results had been available to inform patient care, 25% of patients could have been put on active therapy sooner, while 78% of patients who had therapy optimized during hospitalization could have had therapy optimized sooner. Additionally, AXDX could have reduced time to de-escalation (16 versus 31 h) and escalation (19 versus 31 h) compared with SOC. Conclusions: By providing fast and reliable ID and AST results, AXDX has the potential to improve antimicrobial utilization and enhance antimicrobial stewardship.

Original languageEnglish (US)
Pages (from-to)I16-I23
JournalJournal of Antimicrobial Chemotherapy
StatePublished - Jan 1 2019


ASJC Scopus subject areas

  • Pharmacology
  • Microbiology (medical)
  • Infectious Diseases
  • Pharmacology (medical)

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