Comparison of commercial antimicrobial susceptibility test methods for testing of Staphylococcus aureus and Enterococci against vancomycin, daptomycin, and linezolid

Stefan Riedel; Kar Mun Neoh; Stephen W Eisinger; Lisa M Dam; Tsigereda Tekle; Karen C Carroll

doi:10.1128/JCM.00957-14

Comparison of commercial antimicrobial susceptibility test methods for testing of Staphylococcus aureus and Enterococci against vancomycin, daptomycin, and linezolid

J Clin Microbiol. 2014 Jun;52(6):2216-22. doi: 10.1128/JCM.00957-14. Epub 2014 Apr 9.

Authors

Stefan Riedel¹, Kar Mun Neoh², Stephen W Eisinger², Lisa M Dam³, Tsigereda Tekle⁴, Karen C Carroll⁵

Affiliations

¹ The Johns Hopkins University, School of Medicine, Department of Pathology, Division of Microbiology, Baltimore, Maryland, USA Johns Hopkins Bayview Medical Center, Baltimore, Maryland, USA sriedel2@jhmi.edu.
² The Johns Hopkins University, School of Medicine, Department of Pathology, Division of Microbiology, Baltimore, Maryland, USA.
³ Johns Hopkins Bayview Medical Center, Baltimore, Maryland, USA.
⁴ The Johns Hopkins Hospital, Baltimore, Maryland, USA.
⁵ The Johns Hopkins University, School of Medicine, Department of Pathology, Division of Microbiology, Baltimore, Maryland, USA The Johns Hopkins Hospital, Baltimore, Maryland, USA.

Abstract

Three commercial antimicrobial susceptibility testing (AST) methods were compared to broth microdilution for testing of Staphylococcus aureus and enterococci against vancomycin, daptomycin, and linezolid. Despite high levels of categorical agreement and essential agreement, vancomycin MICs determined by MicroScan were often 1 log2 concentration higher and MICs determined by Phoenix 1 log2 concentration lower. Daptomycin MICs were 1 to 2 log2 concentrations higher by all AST methods, except Etest, potentially impacting definitive antimicrobial therapy for bloodstream infections due to these organisms.

Publication types

Comparative Study
Evaluation Study
Research Support, Non-U.S. Gov't

MeSH terms

Acetamides / pharmacology
Anti-Bacterial Agents / pharmacology*
Daptomycin / pharmacology
Enterococcus / drug effects*
Humans
Linezolid
Microbial Sensitivity Tests / methods*
Oxazolidinones / pharmacology
Staphylococcus aureus / drug effects*
Vancomycin / pharmacology

Substances

Acetamides
Anti-Bacterial Agents
Oxazolidinones
Vancomycin
Linezolid
Daptomycin