Specific Detection of Extended‐Spectrum β‐Lactamase Activities with a Ratiometric Fluorescent Probe

Abstract

The dissemination of antimicrobial resistance around the world is one of the biggest threats to global public health. The acquisition and expression of extended-spectrum β-lactamases (ESBLs) in pathogenic bacterial are mainly responsible for bacterial resistance to third-generation cephalosporins. Reported herein is a ratiometric fluorescent probe for the detection of the activity of ESBLs. This imaging reagent adopts the core structure of cefotaxime as an enzymatic recognition moiety, and exhibits excellent selectivity to ESBLs over other β-lactamases. The specific activation of this sensor by ESBLs can lead to over 2500-fold changes in the fluorescent ratio, which is independent of the concentration of the probe and environmental conditions. Further experiments have demonstrated that this ratiometric fluorescent probe can distinguish bacteria with extended-spectrum antibiotic resistance from a group of clinically important pathogens within a short period of time.

A dual-caged resorufin probe for rapid screening of infections resistant to lactam antibiotics

“…Modification on the lactam structure for ESBL or carbapenemase specific substrates may further differentiate these mechanisms. 33,65,66 After a simple two-step filtration, our CDA/H 2 O 2 assay has been demonstrated to report 10 3 c.f.u./mL of cephalosporin-and carbapenem-resistant bacteria in urine within 2 hours at room temperature. The detection limit may be further improved for example using droplet-based microfluidics.…”

Fluorescent antibiotics for real-time tracking of pathogenic bacteria

“…Furthermore, near-infrared (sensing wavelength in the region of 650–900 nm) fluorophores conjugated with antibiotic can be used for fluorescent imaging of bacterial infections in vivo (detail description in section 4.2 ) [ 39 ]. In addition, the fluorogenic probe (the probe presenting turn-on or ratiometric signal while identifying target in situ) is created by linking one or two selective fluorophores to an antibiotic for real-time detection of target objects (detail description in section 4.3 ) [ 40 , 41 ].…”

“…Using this ratiometric probe, β-Lactamase was detected in real-time to measure gene expression in single live mammalian cells with high sensitivity. In addition, various ratiometric fluorescent antibiotics based on cephalosporin were developed by attaching different fluorophores [ 40 , 86 , 87 ]. Ratiometric fluorescent probe C-2 with fluorescein and rhodamine donor-acceptor pair was used for screening microbes resistant to methoxyimino cephalosporins [ 87 ].…”

Chemiluminescence Detection of Hydrogen Sulfide Release by β-Lactamase-Catalyzed β-Lactam Biodegradation: Unprecedented Pathway for Monitoring β-Lactam Antibiotic Bacterial Resistance

“…Such assays typically require incubation times of 10 to 48 h even after initial isolation of the infecting strain. For direct detection of β-lactamase activity, artificial substrates or reagents leading to either color, fluorescence, or chemiluminescence signal formation are required. − During the last four years, we have developed new chemiluminescence luminophores, which are highly emissive under aqueous conditions. − Very recently, we reported a new sensitive chemiluminescent probe for detection of carbapenemase activity, which incorporates such a highly emissive luminophore . We demonstrated the ability of the probe to detect a number of clinically relevant carbapenemases in bacterial cultures, such as those used for clinical diagnosis.…”