Rapid nucleic acid detection of Escherichia coli O157:H7 based on CRISPR/Cas12a system

Escherichia coli O157:H7 ( E. coli O157:H7) is one of the most dangerous foodborne pathogens causing severe illnesses in the elderly, children and immunocompromised people. Traditional methods could not meet the detection requirements of high speed, sensitivity, and specificity. The clustered regularly interspaced short palindromic repeats (CRISPR)-based diagnostic is a novel high sensitivity and specificity detection method. In this study, a rapid nucleic acid of Escherichia coli O157:H7 was detected using rfbE gene based on CRISPR/Cas12a system. The limit of detection for DNA and bacterial concentrations was 0.9 pg/μL and 6.5 × 10 4  CFU/mL, respectively. Furthermore, when the initial bacterial inoculum was 14 CFU/mL in the ground beef sample, the target was detected after 4 h of culture through Metal Organic Framework immunomagnetic beads (Fe 3 O 4 @ [email protected] 2 ) enrichment.