Blood culture identification (BCID) performance in polymicrobial bacteremia

• DOI: 10.1016/j.diagmicrobio.2023.116086
• Publication Date: 2023-09-14T01:31:20Z
• Authors: William S. Bradford; Monica A. Donnelley; Jeffrey R. Fine; Scott J. Crabtree
• Keywords: Bacteremia; Blood Culture; Multiplex

The rapid multiplex PCR (rmPCR)-based FilmArray® blood culture identification (BCID) assay reduces time from positive blood culture to organism identification. Polymicrobial bacteremia (PMB) is a known area of reduced diagnostic fidelity for BCID and remains incompletely characterized. All cases of clinically confirmed PMB at a large academic single center from a 23-month period were evaluated in a retrospective cohort analysis. A total of 207 samples were identified and studied. Overall, 49.3% (N = 102) of polymicrobial cultures were incompletely identified by FilmArray® result. There were no significant between-group differences in comorbidity status, length of stay, mortality, or source between patients with PMB who had complete versus incomplete BCID identification. Our results suggest that rmPCR-based assays frequently miss organisms in PMB and should be interpreted accordingly.