Abstract
Increasingly difficult-to-treat infections by antibiotic-resistant bacteria have become a major public health challenge. Rapid detection of common resistance mechanisms before empiric antibiotic usage is essential for optimizing therapeutic outcomes and containing further spread of resistance to antibiotics among other bacteria. Herein, we present a bioluminogenic probe, D-Bluco, for rapid detection of β-lactamase activity in viable pathogenic bacteria. D-Bluco is a pro-luciferin caged by a β-lactamase-responsive cephalosporin structure and further conjugated with a dabcyl quencher. The caging and quenching significantly decreased the initial background emission and increased the signal-to-background ratio by more than 1200-fold. D-Bluco was shown to detect a broad range of β-lactamases at the femtomolar level. An ultrasensitive RAPID bioluminescence assay using D-Bluco can detect 10(2) to 10(3) colony forming unit per milliliter (cfu/mL) of β-lactamase-producing Enterobacterales in urine samples within 30 min. The high sensitivity and rapid detection make the assay attractive for the use of point-of-care diagnostics for lactam-resistant pathogens.