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BackgroundRapid identification of causative agents from positive blood culture (PBC) can aid earlier targeted therapy, as well as reduce mortality, length of stay, and costs associated with systemic infections. The BioFire® Blood Culture Identification 2 (BCID2) Panel being developed by BioFire Diagnostics, LLC, aims to maintain or improve the performance of the BioFire® FilmArray® Blood Culture Identification (BCID) Panel with updated and novel assays (15 new analytes: six antimicrobial resistance (AMR), six bacterial, and three fungal analytes). The performance of an RUO BioFire BCID2 Panel during a prospective pilot study is compared with standard of care (SoC), as well as independent PCR comparator assay (compPCR) results.MethodsTwo pilot sites enrolled de-identified PBC (<24 hours post-positivity) for which clinician-ordered SoC tests had been performed. Aliquots of residual PBC and isolates were frozen for compPCR testing of AMR markers and discrepancy resolution. 100 aerobic PBC (A-PBC) and 85 anaerobic PBC (AN-PBC) were tested with the BioFire BCID2 Panel; 70 A-PBCs and 56 AN-PBCs were concurrently tested on BioFire BCID Panel. Also, isolates from PBCs positive for AMR markers were tested using compPCR.ResultsThe BioFire BCID2 Panel results matched SoC results in 176/177 detections from 100 A-PBC, and in 167/168 detections from 85 AN-PBC. Both BioFire panels detected Candida glabrata and Candida parapsilosis from an A-PBC with only C. parapsilosis SOC result; interestingly, C. glabrata was detected by SoC in the paired AN-PBC. False-positive Bacteroides fragilis detection in an AN-PBC was resolved favorably by compPCR. Two patient samples, positive in both A-PBC and AN-PBC by SoC, were not detected by either the Staphylococcus epidermidis or the Staphylococcus spp. assays on the BioFire BCID2 Panel. All 26 AMR marker detections in both types of PBC were concordant with either SoC or compPCR results.ConclusionWith an expanded menu, >99% specificity, and >97% sensitivity, the BioFire BCID2 Panel is expected to provide rapid and accurate results for key pathogens associated with systemic infections, as well as important AMR markers.RUO products used in this study have not been evaluated by the FDA or other regulatory agencies for In Vitro Diagnostic use.Disclosures U. Spaulding, BioFire Diagnostics, LLC: Employee, Salary. J. Stone, BioFire Diagnostics, LLC: Employee, Salary. K. Koch, BioFire Diagnostics, LLC: Employee, Salary. J. Antosch, BioFire Diagnostics, LLC: Employee, Salary. M. Jones, BioFire Diagnostics, LLC: Employee, Salary. Z. Lu, BioFire Diagnostics, LLC: Employee, Salary. T. Todorov, BioFire Diagnostics, LLC: Employee, Salary. S. Kerr, BioFire Diagnostics, LLC: Employee, Salary. K. Holmberg, BioFire Diagnostics, LLC: Employee, Salary. M. Rogatcheva, BioFire: Employee, Salary.

BackgroundRapid diagnosis of causative agents of bloodstream infections improves patient outcomes and antibiotic stewardship. BioFire Diagnostics, LLC, is developing the BioFire® Blood Culture Identification 2 (BCID2) Panel, increasing the coverage of the BioFire® FilmArray® Blood Culture Identification (BCID) Panel for key pathogens and antimicrobial resistance (AMR) markers in aerobic and anaerobic positive blood culture (PBC). This revision expands the menu from 27 to 42 targets, with 26 bacterial (14 revised, six new) and seven fungal analytes (two revised, three new), as well as nine AMR markers (one revised, six new). Notable additions include the anaerobe Bacteroides fragilis, the emerging fungus Candida auris, and the mobile colistin resistance gene, mcr-1. This study details the reactivity and specificity of an RUO BioFire BCID2 panel.MethodsThe prototype was tested with fungal and bacterial isolates, some carrying AMR markers, at two sites by multiple operators. Reactivity was assessed at 106 CFU/mL for 301 analytes, and specificity at 108 CFU/mL for 43 on-panel and 93 off-panel strains. Evaluation included multiple strains for species level and AMR marker assays, as well as multiple species for family/genus level assays. Concordance with standard of care (SoC) results was examined for 126 archived PBC.ResultsTesting against 136 on-panel organisms, phylogenetic-neighbors, and normal cutaneous flora, showed 100% specificity for 41/42 targets. Reactivity was confirmed for 346/351 target analytes, and comprehensive detection was observed for the revised family-level Enteric assay (90/90) and genus-level Staphylococcus spp. (51/51), Streptococcus spp. (17/17), and Candida spp. (67/71) assays. The prototype showed excellent sensitivity (97.1%) and specificity (99.7%) compared with SoC with archived PBC.ConclusionPerformance of this RUO BioFire BCID2 Panel indicates that many key pathogens implicated in bloodstream infections can be identified with high sensitivity and specificity, and highlights the utility of the expanded menu to provide actionable information. Future panel versions will address observed deficiencies.RUO products used in this study have not been evaluated by the FDA or other regulatory agencies for In Vitro Diagnostic use.Disclosures J. Antosch, BioFire Diagnostics, LLC: Employee, Salary. U. Spaulding, BioFire Diagnostics, LLC: Employee, Salary. J. Stone, BioFire Diagnostics, LLC: Employee, Salary. C. Later, BioFire Diagnostics, LLC: Employee, Salary. K. Koch, BioFire Diagnostics, LLC: Employee, Salary. I. Kavetska, BioFire Diagnostics, LLC: Employee, Salary. H. Ton, BioFire Diagnostics, LLC: Employee, Salary. C. Alberti-Segui, bioMérieux: Employee, Salary. A. Grange, bioMereiux, Inc.: Employee, Salary. C. Dubost, bioMérieux: Employee, Salary. M. Rogatcheva, BioFire: Employee, Salary.

Background The US Food and Drug Administration (FDA) has granted Emergency Use Authorization (EUA) for multiple PCR-based tests to aid in the diagnosis and containment of COVID-19. A vast majority of these tests detect only SARS-CoV-2 which causes symptoms similar to those caused by other respiratory pathogens. Hence, other etiologies or co-infections requiring a different therapy may be missed. The prototype BioFire® Respiratory Panel 2.1 (RP2.1) continues the syndromic approach of the FDA-cleared BioFire® Respiratory Panel 2 (RP2), to provide the ability to simultaneously detect 22 common respiratory pathogens, including SARS-CoV-2, from nasopharyngeal swab (NPS) specimens. The goal of this study was to rapidly develop a RP2.1 prototype that contains high-performing SARS-CoV-2 assays and maintains the performance of assays retained from RP2. Methods Twelve assays designed for four SARS-CoV-2 genes were tested for compatibility with the RP2 assays and conditions. All retained RP2 assays were evaluated to verify established RP2 performance. The sensitivity of novel SARS-CoV-2 assays was estimated with nucleic acids at BioFire and contrived live virus NPS samples at MRIGlobal. Primer homology of SARS-CoV-2 assays to &gt; 15,000 SARS-CoV-2 genomes from accessible databases was assessed for in silico inclusivity Results A prototype multiplexed PCR panel containing assays for 22 pathogens was developed in a 5-week period. Of the 12 SARS-CoV-2 assays, 7 were compatible with the RP2 conditions; 2 were selected for the prototype. No false positive results due to cross-reactivity with unintended analytes or non-specific amplification in negative samples were observed for any assays. All retained RP2 assays were detected at or near their established LoD. The SARS-CoV-2 LoD was estimated at 103 -102 genomes/mL with both nucleic acid and live virus spiked into NPS. Together, the assays are 100% inclusive for all 15,370 complete SARS-CoV-2 genomes assessed in silico for reactivity. Conclusion The results of this study indicate a strong potential for RP2.1 to serve as a sensitive comprehensive syndromic option to aid in the diagnosis of COVID-19 as well as respiratory syndromes caused by other pathogens, including co-infections. This study was performed with a test not cleared for diagnostic use. Disclosures All Authors: No reported disclosures