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

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.