Reducing time-to-result in bloodstream infections: comparative evaluation of VITEK® REVEAL™ and QuickMIC® for rapid...

Bloodstream infections (BSI) require rapid and targeted antimicrobial therapy to improve clinical outcomes and reduce mortality. Conventional antimicrobial susceptibility testing (AST) requires 24-48 h to provide phenotypic susceptibility results and Minimum Inhibitory Concentration (MIC) values. In this study, we evaluated two rapid phenotypic AST systems, VITEK® REVEAL™ (bioMérieux, France) and QuickMIC® (Gradientech AB, Uppsala Science Park, Sweden), using the MicroScan WalkAway (Beckman Coulter, USA) system as reference method.

81 monomicrobial Gram-negative Positive Blood Cultures (PBC) were collected between November 2024 and September 2025 at AOU Città della Salute e della Scienza, including multidrug-resistant isolates and ESBL/carbapenemase producers. Performance was assessed by calculating Categorical Agreement (CA), Essential Agreement (EA), Very Major Errors (VME), Major Errors (ME), minor Errors (mE) and bias.

VITEK® REVEAL™ demonstrated excellent overall performances, with CA and EA values of 96.8% and 97.5%, respectively. QuickMIC® showed high overall CA and EA (97.1% and 96.8%, respectively), but a higher proportion of invalid results (6.5%). Overall, both systems displayed better performances for Enterobacterales, whereas lower concordance and higher error rates were observed for P. aeruginosa, highlighting the challenge associated with this pathogen. Regarding Turn-Around-Time (TTR), QuickMIC® provided results significantly earlier than VITEK® REVEAL™ (mean 3.3 h vs 5.5 h), although it required more extensive manual preparation.

Overall, both platforms proved to be reliable tools for rapid AST directly from PBC, with distinct advantages and limitations. Their integration into routine clinical workflows may support earlier targeted therapy and improve antimicrobial stewardship in the management of BSI.