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

Lab Chip. 2024 Sep 24;24(19):4659-4668. doi: 10.1039/d4lc00672k.

Abstract

Escherichia coli O157:H7 is a major foodborne pathogen that poses a significant threat to food safety and human health. Rapid and sensitive detection of viable Escherichia coli O157:H7 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 O157:H7 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 O157:H7. 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 O157:H7 and provides reliable guidance for food safety testing.

MeSH terms

  • Azides* / chemistry
  • Clustered Regularly Interspaced Short Palindromic Repeats
  • Escherichia coli O157* / isolation & purification
  • Food Microbiology / instrumentation
  • Lab-On-A-Chip Devices
  • Limit of Detection
  • Microbial Viability
  • Microfluidic Analytical Techniques / instrumentation
  • Propidium* / analogs & derivatives
  • Propidium* / chemistry

Substances

  • propidium monoazide
  • Azides
  • Propidium