Comparing BioFire FilmArray BCID2 and BCID Panels for Direct Detection of Bacterial Pathogens and Antimicrobial Resistance Genes from Positive Blood Cultures
Venere Cortazzo, Tiziana D’Inzeo, Liliana Giordano, Giulia Menchinelli, Flora Marzia Liotti, Barbara Fiori, Flavio De Maio, Francesco Luzzaro, Maurizio Sanguinetti, Brunella Posteraro, Teresa Spanu
Abstract
A mong molecular assays currently developed for detection and identification of pathogens (and their antimicrobial resistance genes) in positive blood cultures (BCs) (1), the BioFire FilmArray blood culture identification (BCID) panel (bioMérieux, Marcy l'Etoile, France), a multiplex PCR assay with ,2 min of hands-on time and an ;1-h turnaround time, allows for syndromic diagnosis of bloodstream infection (BSI) (2, 3).Previously, the panel could identify 24 etiological agents of BSI (11 Gram-negative bacteria, 8 Gram-positive bacteria, and 5 yeast species), as well as three antimicrobial resistance genes (mecA, vanA/B, and bla KPC , which encodes Klebsiella pneumoniae carbapenemase).Now, the BioFire FilmArray BCID2 panel encompasses 43 molecular targets associated with BSI, including 15 Gram-negative bacteria, 11 Gram-positive bacteria, 7 yeast species, and 10 antimicrobial resistance genes (https://www.biomerieux-diagnostics.com/biofire-bcid-panel).The last targets include genes encoding carbapenemases (IMP, KPC, OXA-48-like, NDM, and VIM), colistin resistance (mcr-1), extendedspectrum b-lactamase (ESBL) (CTX-M), methicillin resistance (mecA/C and, specifically for methicillin-resistant Staphylococcus aureus [MRSA], mecA/C and MREJ [mec right-extremity junction]), or vancomycin resistance (vanA/B).Unlike BCID, no published studies to date reported on BCID2 performance.This study evaluated and compared the accuracy of BCID2 with that of BCID to identify bacterial species and relative antimicrobial resistance genes directly from positive BCs.We used archived samples from positive BCs (1.5 ml thereof mixed with 100 ml of dimethyl sulfoxide and stored at 280°C), which had prospectively been processed with the BD Bactec 9240 (BD Diagnostic Systems, Sparks, MD), BacTAlert 3D (bioMérieux), or BacTAlert Virtuo (bioMérieux) system at two hospital microbiology laboratories from January 2018 to August 2020.For BCID2 testing, samples were thawed and allowed to reach room temperature, and a 200-ml aliquot was lysed and processed following the manufacturer's instructions.We compared BCID2 results with those of conventional identification or detection (i.e., MALDI BioTyper analysis and, relative to antimicrobial resistance genes, PCR sequencing, both performed on microbial isolates subcultured from positive BC samples), which was considered the reference method in this evaluation, or with those of the BCID.