Integrated RPA–CRISPR/Cas12a Technology for Rapid Detection of Salmonella enterica

Background/Objectives: Rapid identification of foodborne pathogens is of high practical significance because it enables prompt epidemiological response, timely patient management, and effective sanitary control of food products. In this study, we developed an integrated molecular platform combining recombinase polymerase amplification (RPA) with CRISPR/Cas12a technology for rapid, sensitive, and specific detection of Salmonella enterica. Methods: Four virulence genes (sirA, stn, siiD, and pagN) were selected as targets to ensure reliable pathogen identification. Reaction conditions were optimized using the Moraxella bovoculi Cas12a (MbCas12a) nuclease. The study focused on integrating isothermal amplification with a custom-engineered hardware solution for visual fluorescence detection. Results: The developed method demonstrated sensitive and specific detection, with no cross-reactivity to non-target microorganisms. Optimization allowed for a substantially reduced assay time of approximately 30 min. As a result, a portable fluorescence visualization approach was developed, featuring a 3D-printed housing and an integrated ultraviolet light source for direct visual fluorescence detection. This allows rapid differentiation of samples without specialized laboratory equipment, making it suitable for field applications. Conclusions: The combination of isothermal amplification, MbCas12a-based detection, and the portable fluorescence visualization approach provides a versatile platform for rapid diagnostics and food safety monitoring. This approach has strong potential to improve public health outcomes and enhance the resilience of food supply chains by enabling accessible, field-deployable pathogen detection.