Single Escherichia coli bacteria detection using a chemiluminescence digital microwell array chip.

Area of Science:

• Biotechnology
• Analytical Chemistry
• Microbiology

Background:

• Accurate detection of Escherichia coli (E. coli) is crucial for public health, yet conventional methods are time-consuming and lack differentiation between live and dead bacteria.
• Existing rapid methods often require complex equipment and procedures, limiting their field applicability.
• There is a need for a fast, sensitive, and portable method for E. coli detection that can distinguish viable cells.

Purpose of the Study:

• To develop and validate a novel chemiluminescence digital microwell array chip for rapid and sensitive detection of E. coli.
• To enable differentiation between live and dead E. coli cells using the developed platform.
• To assess the performance of the chip compared to standard methods and evaluate its suitability for on-site applications.

Main Methods:

• A chemiluminescence digital microwell array chip was designed utilizing the enzymatic activity of β-D-glucuronidase in E. coli to hydrolyze a substrate.
• Single E. coli cells were encapsulated in picoliter microwells for digital detection and quantification.
• Differentiation of live and dead bacteria was achieved by monitoring bacterial proliferation and enzyme expression over time.
• The chip's performance was tested against samples treated with pH and chlorination to assess viability differentiation.

Main Results:

• The chemiluminescence digital microwell array chip achieved rapid detection of E. coli, reducing testing time from over 24 hours to 2-4 hours.
• The method demonstrated high sensitivity by enabling single bacterial detection and accurate quantification through digital counting.
• The platform successfully differentiated between live and dead E. coli cells, even in the presence of sample turbidity and varying temperatures.
• Performance was comparable to standard plate counting methods, indicating reliability.

Conclusions:

• The developed chemiluminescence digital microwell array chip offers a significant advancement for rapid, sensitive, and accurate E. coli detection.
• Its ability to distinguish live from dead bacteria and its portability make it a promising tool for on-site monitoring in environmental, food, and clinical settings.
• This technology addresses the limitations of conventional methods, providing a faster and more versatile alternative for E. coli analysis.