The Verigene BC-GN assay correctly identified all 51 Gram-negative bacilli (GNB) from positive blood cultures and all 14 carbapenemase enzymes tested. The assay gave organism identification (ID) results an average of 24 h faster compared to conventional identifications. Medical management could have been modified for 31.8% of patients an average 33 h sooner. In conclusion, the BC-GN assay is a very accurate, rapid assay which would allow for more-immediate medical management decisions in patients with bacteremia from GNB. Early and appropriate therapeutic interventions have been shown to reduce mortality associated with hospital-acquired bloodstream infections (BSIs) (1, 2). The clinical decision of whether to broaden antimicrobial coverage from that of initial empirical therapy or to narrow coverage is supported by knowledge of the organism identification (ID) and antimicrobial susceptibility testing (AST) profile. Since the 1970s, the prevalence of Gram-positive pathogens causing BSIs has typically exceeded that of Gram-negative bacilli (GNB). However, in recent years, the incidence of BSIs caused by GNB has been increasing (3). Additionally, there has been a dramatic increase of antibiotic resistance in GNB mediated by extended-spectrum ␤-lactamase (ESBL) and carbapenemase enzymes.The current workup of a positive blood culture includes Gram staining, plating to solid medium, spot testing for ID, and/or automated ID assays. This process can take up to 18 to 24 h for an ID result and up to an additional 24 h for AST results. The Verigene Gram-negative blood culture (BC-GN) assay (Nanosphere, Inc., Northfield, IL) is a FDA-approved, random-access, automated, multiplexed nucleic acid test for the rapid ID of the most common GNB (and selected resistance markers [RMs]) from blood cultures within 2 h of positivity (4). The assay will allow detection of the following organisms and RMs: Escherichia coli, Klebsiella pneumoniae, Klebsiella oxytoca, Enterobacter species, Citrobacter species, Proteus species, Acinetobacter species, Pseudomonas aeruginosa, CTX-M, KPC, NDM, VIM, IMP, and OXA. This study was undertaken with the following aims: (i) to determine the accuracy of this new assay for the ID of GNB and RM detection, (ii) to review turnaround times (TAT) for molecular ID compared to routine culture ID, and (iii) to ascertain whether/when medical management could have changed based on the BC-GN result in comparison to conventional methods.(This study was partially presented in poster form at the 113th General Meeting of the American Society for Microbiology, 2013.)Fifty-four consecutive inpatient positive blood cultures received from August 2013 to January 2014 that gave positive results between 7 a.m. and 11 p.m. were tested immediately by the BC-GN assay upon confirmation of GNB by Gram staining. All patients with positive blood cultures for Gram-negative bacilli detected during these hours were included in this analysis, but only the initial positive blood culture for each patient was included in the study. The re...