Low-cost, real-time detection of bacterial growth via diffraction-based sensing

Area of Science:

• Microbiology
• Biophysics
• Biosensing

Background:

• Antibacterial resistance poses a global health threat, particularly in developing nations.
• Current antibiotic susceptibility testing (AST) methods are often slow and costly, limiting their use in low-resource settings.
• There is a critical need for rapid, affordable diagnostics to guide effective antimicrobial treatment.

Purpose of the Study:

• To develop a simple, cost-effective method for rapid bacterial growth detection.
• To demonstrate the feasibility of using diffraction sensing as a precursor to AST.
• To provide a potential solution for accessible diagnostics in resource-limited healthcare environments.

Main Methods:

• Fabrication of bacterial diffraction gratings (1D) using soft agar gel templates.
• Directing bacterial (Escherichia coli DH5α) attachment to form gratings with minimal background signal.
• Monitoring diffraction spot intensities with a basic laser and photodetector setup under growth and no-growth conditions.

Main Results:

• Bacterial growth was detectable within 10-20 minutes.
• Significant differences in diffraction spot intensities were observed between growth and no-growth (ampicillin) conditions.
• The method demonstrated high sensitivity at room temperature.

Conclusions:

• The developed diffraction sensing approach is a rapid and cost-effective method for detecting bacterial growth.
• This technique shows promise as an accessible alternative for point-of-care antibiotic susceptibility testing.
• Further adaptation could significantly improve infectious disease management in resource-limited settings.