Microfluidic isothermal amplification strategy coupled with improved propidium monoazide (PMAxx) for rapid detection of six viable foodborne pathogens

Based on the combination of the centrifugal microfluidic chip, programable loop-mediated isothermal amplification (pLAMP), and improved propidium monoazide (PMAxx), a new method called PMAxx-mpLAMP was developed for the quantitative determination of six viable foodborne pathogens in real food samples. Specific target genes and primers were designed and verified, and the PMAxx conditions were optimized. Treatment with PMAxx before pLAMP eliminated false-positive outcomes from dead bacteria and identified viable target bacteria with good specificity and sensitivity. The PMAxx-mpLAMP strategy could detect approximately 102 ∼ 103 CFU/mL pathogens without any pre-enrichment and 101 CFU/mL after a short period of enrichment. In addition, the PMAxx-mpLAMP strategy was performed in the presence of a high concentration of dead bacteria and non-target bacteria. Therefore, the established PMAxx-mpLAMP strategy in this study has potential value for the rapid and sensitive detection of foodborne pathogens.