Analytical performance and potential clinical utility of the GenMark Dx ePlex® blood culture identification gram-positive panel

T P McCarty; C M White; J Meeder; D Moates; H M Pierce; W S Edwards; J Hutchinson; R A Lee; S M Leal Jr

doi:10.1016/j.diagmicrobio.2022.115762

Analytical performance and potential clinical utility of the GenMark Dx ePlex® blood culture identification gram-positive panel

Diagn Microbiol Infect Dis. 2022 Nov;104(3):115762. doi: 10.1016/j.diagmicrobio.2022.115762. Epub 2022 Jul 11.

Authors

T P McCarty¹, C M White², J Meeder³, D Moates³, H M Pierce³, W S Edwards¹, J Hutchinson³, R A Lee¹, S M Leal Jr⁴

Affiliations

¹ Department of Medicine, Division of Infectious Diseases, The University of Alabama at Birmingham, Birmingham, AL, USA.
² Department of Medicine, Division of Infectious Diseases, The University of Alabama at Birmingham, Birmingham, AL, USA; Department of Hospital Medicine, The University of Alabama at Birmingham, Birmingham, AL, USA.
³ UAB Fungal Reference Laboratory, Department of Pathology, Division of Laboratory Medicine, The University of Alabama at Birmingham, Birmingham, AL, USA.
⁴ UAB Fungal Reference Laboratory, Department of Pathology, Division of Laboratory Medicine, The University of Alabama at Birmingham, Birmingham, AL, USA. Electronic address: smleal@uabmc.edu.

PMID: 35988351
DOI: 10.1016/j.diagmicrobio.2022.115762

Abstract

The test performance and potential clinical utility of the ePlex® BCID Gram-Positive (GP) Panel was evaluated relative to MALDI-TOF mass spectrometry on bacterial isolates and traditional antimicrobial susceptibility testing. All GP bacteria (n = 100) in the study were represented on the panel including 50 common skin contaminants, and 7/7 coinfections. The positive percent agreement (PPA) was 97/97 with 2 false positives. Detection of vanA yielded a PPA of 4/4 and NPA of 9/9. mecA gene detection exhibited a PPA of 14/14 and NPA of 14/14 for S. aureus and a PPA of 31/32(97%) and NPA of 16/16 for CNS with 1 false negative. Chart reviews (n = 80) identified a mean 24.4h faster time to organism identification, 53.4h earlier optimization in 15(18.8%) patients based on AMR gene detection, 29.2h earlier optimization for 8(10%) patients infected with organisms, such as streptococci, with very low resistance rates, and 42.9h earlier discontinuation of antimicrobials for 14(17.5%) patients with contaminant cultures.

Keywords: Bacteremia; Blood cultures; Gram positive bacteria; Rapid molecular diagnostics.

MeSH terms

Bacteremia* / microbiology
Blood Culture* / methods
Gram-Positive Bacteria / genetics
Humans
Staphylococcus aureus