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Salmonella is a crucial food‐borne pathogen causing food poisoning, leading to severe public health events. Here, we developed a technique by integrating recombinase polymerase amplification with CRISPR‐LbCas12a and employing two targets with engineered crRNA for detection of Salmonella (RPA‐LbCas12a‐TTECDS). Our findings revealed that this novel method rapidly detects trace Salmonella in food through fluorescence intensity and provides a template for other food‐borne pathogen detection methods. Further, crRNA was optimized to increase detection sensitivity. Double targets were used to enhance the detection accuracy, reaching the level of qPCR, which was superior to fluorescent RPA. The RPA‐LbCas12a‐TTECDS system specifically detected Salmonella levels as low as 50 CFU per ml at 37°C in 1 h. In summary, a simple, rapid, sensitive and high accuracy detection technique based on CRISPR‐Cas12a was created for Salmonella detection without complicated equipment. Significance and Impact of the Study: The emergence of CRISPR‐Cas12a provides a new technique for detection methods. In this study, we developed a rapid, sensitive, and high accuracy RPA‐LbCas12a‐TTECDS based toolbox for Salmonella detection. This method is easy to operate with a completion span of 50 min by a fluorescence detector. The simple and quick‐to‐read method is potentially useful as point‐of‐care testing for Salmonella. [ABSTRACT FROM AUTHOR]

Droplet digital polymerase chain reaction (ddPCR) is one of the newest and most promising tools providing absolute quantification of target DNA molecules. Despite its emerging applications in microorganisms, few studies reported its use for detecting lactic acid bacteria. This study evaluated the applicability of a ddPCR assay targeting molecular genes obtained from in silico analysis for detecting Lactiplantibacillus plantarum subsp. plantarum, a bacterium mainly used as a starter or responsible for fermentation in food. The performance characteristics of a ddPCR were compared to those of a quantitative real-time PCR (qPCR). To compare the linearity and sensitivity of a qPCR and ddPCR, the calibration curve for a qPCR and the regression curve for a ddPCR were obtained using genomic DNA [102–108 colony-forming units (CFU)/mL] extracted from a pure culture and spiked food sample. Both the qPCR and ddPCR assays exhibited good linearity with a high coefficient of determination in the pure culture and spiked food sample (R2 ≥ 0.996). The ddPCR showed a 10-fold lower limit of detection, suggesting that a ddPCR is more sensitive than a qPCR. However, a ddPCR has limitations in the absolute quantitation of high bacterial concentrations (>106 CFU/mL). In conclusion, a ddPCR can be a reliable method for detecting and quantifying lactic acid bacteria in food. [ABSTRACT FROM AUTHOR]