Hydrogen sulfide activated chemiluminescence probe for facile and robust discrimination of β-lactam-resistant bacteria.

Antibiotic-resistant bacteria, primarily driven by β-lactamases, significantly undermine the effectiveness of β-lactam antibiotics, posing a grave threat to human health. As such, it is crucial to develop sensitive and rapid diagnostic methods to distinguish antibiotic-resistant bacteria from antibiotic-susceptible ones, thereby guiding clinical drug use. In this study, we present a selective "turn-on" chemiluminescent probe (HS-CL) created by attaching a 2-iodobenzoyl group to a phenoxy-dioxetane scaffold. The interaction of antibiotic-resistant bacteria with β-lactams generates hydrogen sulfide molecules, which selectively trigger probe HS-CL, resulting in a noticeable increase in the chemiluminescent signal. This enables point-of-care testing for bacterial resistance. Probe HS-CL demonstrated excellent specificity and a linear response to hydrogen sulfide concentration ranging from 5 to 100 μM (R2 = 0.9822), with a detection limit of 1.02 μM. We tested this method with four different antibiotic-resistant bacterial strains, including Acinetobacter baumannii, methicillin-resistant Staphylococcus aureus, Escherichia coli, and Klebsiella pneumoniae, and two antibiotic-susceptible strains, Staphylococcus aureus and Escherichia coli. This probe can directly indicate the presence of antibiotic resistance in examined β-lactams. Most notably, when we applied this technique to bacteria isolated from patients, including Escherichia coli, Klebsiella pneumoniae, and Pseudomonas aeruginosa, the chemiluminescence probe successfully distinguished β-lactam-resistant strains from antibiotic-susceptible ones.