Fluorescent Probe for the pH-Independent Rapid and Sensitive Direct Detection of Urease-Producing Bacteria

Area of Science:

• Biomedical Engineering
• Microbiology
• Materials Science

Background:

• Urease-producing bacteria are significant pathogens linked to peptic ulcer disease, gastric cancer, and various infections.
• Current detection methods often rely on indirect metabolite quantification, which can be affected by environmental factors.
• There is a need for sensitive, selective, and robust methods for direct urease activity detection.

Purpose of the Study:

• To design and develop fluorescent polymeric nanoparticles (PNP_FITC) for direct detection of urease activity.
• To evaluate the performance of PNP_FITC in detecting urease and urease-producing bacteria.
• To compare the novel method with existing standard techniques for bacterial detection.

Main Methods:

• Design of fluorescent polymeric particles (PNP_FITC) that degrade upon urease enzymatic activity.
• Quantification of urease activity by measuring the increase in fluorescent signal intensity.
• Testing PNP_FITC with specific urease-producing bacterial strains (Klebsiella pneumoniae, Enterobacter cloacae) and comparing with a pH-based method.

Main Results:

• PNP_FITC demonstrated a linear response to urease in the range of 0-7.5 U/mL, with a limit of detection of 0.4 U/mL.
• The fluorescent particles successfully detected urease-producing bacteria at a concentration of 10^3 bacteria/mL.
• The PNP_FITC method showed superior sensitivity and robustness compared to the reference pH-based detection method.

Conclusions:

• PNP_FITC provides a direct, sensitive, and selective method for detecting urease activity.
• This approach overcomes limitations of standard methods, offering improved performance for bacterial detection.
• PNP_FITC holds promise for developing advanced point-of-care diagnostics for prompt bacterial infection identification.