Rapid and simultaneous detection of Salmonella, Shigella, and Staphylococcus aureus in food using a multiplex RT-PCR assay based on immunomagnetic separation

Abstract:

[Objective] This study aimed to develop a rapid and simultaneous detection method for Salmonella, Shigella, and Staphylococcus (S.) aureus in food. [Methods] Magnetic beads coated with speci?c antibodies were used to capture target pathogens from 250 mL at 37 °C. After quick DNA extraction, multiplex RT-PCR was applied to detect the target pathogens with three sets of specific primers and probes. [Results] The limit of detections of immunomagnetic separation (IMS)-multiplex real-time PCR (RT-PCR) method were 2.0 CFU/g for Salmonella, 6.8 CFU/g for shigella and 9.6 CFU/g for S. aureus. The sensitivity, specificity, and accuracy of this method were 99.2%, 100%, and 99.5%, respectively. One hundred fifty-one samples were tested using the IMS-multiplex RT-PCR and GB methods, and only one negetive deviation was detected. [Conclusion] The IMS-multiplex RT-PCR method with high sensitivity, specificity and accuracy could enable the simultaneous detection of Salmonella, Shigella, and S. aureus in food within 8 h and offers the opportunity for a quick response in an emergency when these bacteria are detected.