Fluorescent Mesoporous Nanoparticles for β-Lactamase Screening Assays

Area of Science:

• Biochemistry
• Nanotechnology
• Microbiology

Background:

• Antibiotic resistance is a growing global health threat.
• Beta-lactamase enzymes are a primary mechanism of resistance to beta-lactam antibiotics.
• Rapid detection of beta-lactamase activity is crucial for effective clinical treatment.

Purpose of the Study:

• To develop a sensitive and rapid screening method for determining beta-lactamase activity.
• To utilize pH-sensitive fluorescent dye-doped mesoporous silica nanoparticles for detection.
• To identify antibiotic-resistant and susceptible bacterial strains from clinical samples.

Main Methods:

• Encapsulation of penicillin G substrate within mesoporous silica nanoparticles doped with a pH-sensitive fluorescent dye.
• Monitoring fluorescence quenching due to pH changes upon penicillin G hydrolysis by beta-lactamase.
• Testing the method on 25 clinical bacterial samples.

Main Results:

• The nanoparticles enhanced the beta-lactamase-catalyzed reaction rate and stabilized the substrate.
• The method successfully identified antibiotic-resistant and susceptible strains among the tested samples.
• Detection of beta-lactamase activity was achieved in less than one hour with a low detection limit of 7.8×10^-4 U/mL within two hours.

Conclusions:

• The proposed method offers a sensitive and rapid approach for detecting beta-lactamase activity in clinically relevant samples.
• This assay can aid in the timely identification of antibiotic-resistant bacteria.
• The use of dye-doped nanoparticles provides an effective platform for enzyme activity-based bacterial detection.