Bloodstream infection survival is linked to timely administration of optimal antimicrobial therapy. Commercial multiplex polymerase chain reaction (PCR) assays, such as the BioFire Blood Culture Identification Panel (BCID) used for the rapid diagnosis of bloodstream infections, have significantly improved the turnaround time for optimisation of antimicrobial therapy. Reported concordance with culture-based methods and multiplex PCR analysis is high and only limited by (1) the range of targets available on the multiplex panel; and (2) the complexity of microorganisms present in the blood culture specimen. In this study, we evaluated the use of the BioFire Blood Culture Identification 2 panel (BCID2), including an expanded repertoire of targets for Gram-positive and Gram-negative bacteria, yeast and antimicrobial resistance genes compared to the BCID panel. The BCID2 panel identified microorganisms in 39/42 (92.9%) blood cultures where monomicrobial growth was detected; the three unidentified blood cultures contained organisms not included in the BCID2 panel. Polymicrobial blood culture analysis revealed a lower degree of concordance (28.6%); however, most disagreement was due to the culture-based identification of off-panel microorganisms of low clinical significance. Turnaround time, from blood culture collection to organism identification on the blood cultures correctly identified by BCID2, was 24.6 (±16.8) hours for the BCID2 panel versus 38.2 (±21.9) hours for conventional methods. Analysis of the theoretical impact of the BCID2 identification on clinical management found therapy would be altered in 45.1% (23/51) of patients. The BCID2 panel is anticipated to improve the diagnosis and antimicrobial management of patients with serious bloodstream infections.
Keywords: Bloodstream; PCR; antimicrobial resistance; blood culture.
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