From Etest to Vitek 2: Impact of Enterococcal Linezolid Susceptibility Testing Methodology on Time to Active Therapy

Cynthia T Nguyen; Cindy Bethel; Natasha N Pettit; Angella Charnot-Katsikas

doi:10.1128/AAC.00302-20

From Etest to Vitek 2: Impact of Enterococcal Linezolid Susceptibility Testing Methodology on Time to Active Therapy

Antimicrob Agents Chemother. 2020 Aug 20;64(9):e00302-20. doi: 10.1128/AAC.00302-20. Print 2020 Aug 20.

Authors

Cynthia T Nguyen¹, Cindy Bethel², Natasha N Pettit³, Angella Charnot-Katsikas²

Affiliations

¹ Department of Pharmacy, University of Chicago Medicine, Chicago, Illinois, USA [email protected].
² Department of Pathology, University of Chicago Medicine, Chicago, Illinois, USA.
³ Department of Pharmacy, University of Chicago Medicine, Chicago, Illinois, USA.

Abstract

Different linezolid antimicrobial susceptibility testing (AST) methodologies yield various results. In 2018, we transitioned our linezolid AST methodology from the Etest to Vitek 2. We sought to evaluate the impact of this change on antibiotic use among 181 inpatients with vancomycin-resistant enterococcal (VRE) infections. The transition from Etest to Vitek 2 resulted in an increase in linezolid susceptibility (38% versus 96%; P < 0.001) and a reduction in time to active antibiotic therapy (3 versus 2.6 days; P = 0.007).

Keywords: linezolid; microbial sensitivity tests; vancomycin-resistant enterococci.

MeSH terms

Anti-Bacterial Agents / pharmacology
Disk Diffusion Antimicrobial Tests
Enterococcus* / genetics
Gram-Positive Bacterial Infections* / drug therapy
Humans
Linezolid / pharmacology
Microbial Sensitivity Tests

Substances

Anti-Bacterial Agents
Linezolid