A comparative analysis of performance and time-to-result for VITEK REVEAL versus MicroScan during antimicrobial...

Fast and reliable antimicrobial susceptibility testing (AST) is essential for timely optimization of therapy in patients with bloodstream infections. This multicenter study assessed the performance of the bioMérieux VITEK REVEAL (VITEK REVEAL) system in comparison with the Beckman Coulter MicroScan (MicroScan) using positive blood culture (PBC) isolates. A total of 553 gram-negative PBCs were obtained from six clinical sites, with Enterobacterales representing the majority (91.1%, 504/553). Overall, 7,945 antimicrobial/organism combinations were evaluated to compare AST performance between VITEK REVEAL and MicroScan. VITEK REVEAL demonstrated strong concordance with MicroScan, achieving 98.1% essential agreement (EA) and 96.0% categorical agreement (CA). High agreement rates were observed for most antimicrobials, including amikacin, ceftazidime-avibactam, and meropenem-vaborbactam, each showing 100% EA and CA. Across all evaluations, discrepancies included 38 very major discrepancies (VMDs), 64 major discrepancies (MDs), and 218 minor discrepancies. Reference broth microdilution discrepant testing resolved most VMDs in favor of VITEK REVEAL, whereas most MDs aligned with MicroScan results. Species-level performance demonstrated strong agreement: Escherichia coli (98.1% EA, 95.6% CA), Klebsiella pneumoniae (99.2% EA, 97.7% CA), and Pseudomonas aeruginosa (97.4% EA, 95.1% CA). Time-to-result (TTR) analysis highlighted a major advantage of the VITEK REVEAL system. The mean overall TTR was 7.9 h (SD 0.4 h); sequential reporting enabled earlier results with a mean TTR of 6.5 h (SD 1.1 h). On average, VITEK REVEAL provided AST results 26-32 h (includes 18-24 h subculture for MicroScan) earlier than MicroScan, supporting its utility for fast, accurate AST reporting and potentially improving early antimicrobial decision-making.IMPORTANCEThis study represents one of the largest evaluations of VITEK REVEAL for fast antimicrobial susceptibility testing (AST) systems, including 553 gram-negative positive blood cultures across six clinical sites in the United States. The findings provide critical evidence for laboratories considering the adoption of fast AST, demonstrating that VITEK REVEAL delivers a strong combination of essential and categorical agreement (98.1% essential agreement [EA], 96.0% categorical agreement [CA] across 7,945 antimicrobial/organism combinations) and markedly reduced time-to-result (TTR). VITEK REVEAL performed consistently across key Enterobacterales and non-fermenters, including resistant phenotypes and β-lactam/β-lactamase inhibitor agents, underscoring its utility in diverse clinical scenarios. By providing susceptibility results 26-32 h earlier than MicroScan, this system may contribute to nimbler clinical decision-making, allowing for better antimicrobial stewardship practices.