Abstract
Rapid and accurate diagnosis of bacterial carbapenemases remains a major challenge for clinical laboratories. A novel assay was developed here using fluorescence identification of β-lactamase activity (FIBA) to permit rapid detection and classification of bacterial carbapenemases. By mixing a fluorogenic β-lactamase substrate, β-LEAF (β-lactamase enzyme-activated fluorophore), with bacterial isolates plus the respective inhibitor (imipenem for noncarbapenemase β-lactamases, clavulanic acid for type A carbapenemases, and EDTA for type B carbapenemases), objective results with 95% to 100% sensitivity and specificity were generated in 10 min. FIBA is ≈$1/test and consists of only a single mixing step. Given the combination of rapidity, accuracy, low cost, and simplicity, this novel carbapenemase detection and classification assay is well positioned to be applied in clinical microbiology laboratories to provide guidance for the choice of proper treatment and control of globally prevalent carbapenemase-positive infections.