Novel electronic biosensor for automated inoculum preparation to accelerate antimicrobial susceptibility testing

Sci Rep. 2021 May 31;11(1):11360. doi: 10.1038/s41598-021-90830-2.

Abstract

A key predictor of morbidity and mortality for patients with a bloodstream infection is time to appropriate antimicrobial therapy. Accelerating antimicrobial susceptibility testing from positive blood cultures is therefore key to improving patient outcomes, yet traditional laboratory approaches can require 2-4 days for actionable results. The eQUANT-a novel instrument utilizing electrical biosensors-produces a standardized inoculum equivalent to a 0.5 McFarland directly from positive blood cultures. This proof-of-concept study demonstrates that eQUANT inocula prepared from clinically significant species of Enterobacterales were comparable to 0.5 McF inocula generated from bacterial colonies in both CFU/ml concentration and performance in antimicrobial susceptibility testing, with ≥ 95% essential and categorical agreement for VITEK2 and disk diffusion. The eQUANT, combined with a rapid, direct from positive blood culture identification technique, can allow the clinical laboratory to begin antimicrobial susceptibility testing using a standardized inoculum approximately 2-3 h after a blood culture flags positive. This has the potential to improve clinical practice by accelerating conventional antimicrobial susceptibility testing and the resulting targeted antibiotic therapy.

MeSH terms

  • Algorithms
  • Automation
  • Biosensing Techniques
  • Colony Count, Microbial
  • Electronics*
  • Evaluation Studies as Topic
  • Feasibility Studies
  • Microbial Sensitivity Tests / methods*
  • Microbial Sensitivity Tests / standards
  • Proof of Concept Study