Fast and sensitive detection of viable Escherichia coli O157:H7 using a microwell-confined and propidium monoazide-assisted digital CRISPR microfluidic platform.

ABSTRACT

Escherichia coli O157H7 is a major foodborne pathogen that poses a significant threat to food safety and human health. Rapid and sensitive detection of viable Escherichia coli O157H7 can effectively prevent food poisoning. Here, we developed a microwell-confined and propidium monoazide-assisted digital CRISPR microfluidic platform for rapid and sensitive detection of viable Escherichia coli O157H7 in food samples. The reaction time is significantly reduced by minimizing the microwell volume, yielding qualitative results in 5 min and absolute quantitative results in 15 min. With the assistance of propidium monoazide, this platform can eliminate the interference from 99% of dead Escherichia coli O157H7. The direct lysis method obviates the need for a complex nucleic acid extraction process, offering a limit of detection of 3.6 × 101 CFU mL-1 within 30 min. Our results demonstrated that the platform provides a powerful tool for rapid detection of Escherichia coli O157H7 and provides reliable guidance for food safety testing.