For quick and multiple detection of the contamination of foodborne pathogens in infant milk powder, a dual enzymatic recombinase amplification (ERA) method for the rapid detection of Cronobacter, Salmonella, Listeria monocytogenes and Staphylococcus aureus were established in this study. Firstly, specific and efficient primers and probes were selected for these foodborne pathogens. Then, two groups of dual-ERA systems were established and optimized. The minimum detection limit was 10^-2 ng/μL for Salmonella, L. monocytogenes and S. aureus, and 1 ng/μL for Cronobacter. The results of simulated contamination test showed that the four foodborne pathogens could be detected simultaneously after 6 hours of enrichment culture at an initial contamination level of 1 CFU/mL. When this method and real-time polymerase chain reaction (PCR) were used to detect commercial infant milk powder, consistent results were obtained, which confirmed the accuracy and reliability of the dual-ERA method. This method could simultaneously detect the four foodborne pathogens in about 20 minutes. Compared with the traditional method and real-time PCR, the detection efficiency was significantly improved, which is of great significance for promoting the rapid screening of foodborne pathogens.

Three rapid visual methods, namely chromogenic, fluorescence and test strip, for the rapid detection of Burkholderia gladioli pv. cocovenenans in foods were established based on enzymatic recombinase amplification (ERA). Primers and probes were designed and screened based on the bonM gene of B. gladioli pv. cocovenenans. Then the specificity and sensitivity of the three methods were evaluated, as well as their applicability and accuracy in the detection of commercial food samples. The results showed that three strains of B. gladioli pv. cocovenenans, but not other common foodborne pathogens and other B. gladioli strains, were amplified by the three methods, indicating their good specificity. The detection limits of these methods were all 10^-2 ng/μL, and their sensitivity was good. Out of 15 commercial samples, two tested positive by each of these methods with a detection rate of 13.3%. This result was consistent with that of the national standard method, indicating that our methods had good applicability and accuracy. All three methods give results that can be observed by the naked eye after amplification at 37 ℃ for 15 min, which provide a new and simple strategy for the rapid, visual and on-site screening of B. gladioli pv. cocovenenans in foods.