Recently, Prof. Yingjian Lu's team from Nanjing University of Finance and Economics (NUFE) published a research paper entitled “Rapid and accurate AuNPs-sodium deoxycholate-propidium monoazide-qPCR technique for simultaneous detection of viable Listeria monocytogenes and Salmonella” in Food Control (CAS 1, IF=5.6), an authoritative food journal. Rapid and accurate AuNPs-sodium deoxycholate-propidium monoazide-qPCR technique for simultaneous detection of viable Listeria monocytogenes and Salmonella”. Dr. Huang Jiaming was the first author, and Ms. Sun Jing and Prof. Lu Yingjian were the co-corresponding authors.

Listeria monocytogenes and Salmonella monocytogenes are common pathogens in dairy products that can cause foodborne illness. Rapid and accurate detection is essential for effective control of their infections. In this study, highly specific primers for Listeria monocytogenes (AX10_RS05385) and Salmonella (SEEPA511_RS03120) were screened using bioinformatics methods and combined to construct a dual qPCR system. On this basis, propidium azide bromide (PMA) was used to make up for the defect that qPCR could not distinguish between viable and non-viable bacteria, and the optimal processing conditions of PMA were explored (including 20 μM PMA, incubation time: 8 min, exposure time: 5 min). The addition of sodium deoxycholate (SD) could maximize the efficiency of PMA to inhibit the amplification of non-viable bacteria. Gold nanoparticles (AuNPs) enhanced the fluorescence signal of the qPCR system by about 20%, thus establishing a rapid, highly specific and sensitive AuNPs-SD-PMA-qPCR assay. After 6 hours of enrichment, the method could accurately detect Listeria monocytogenes and Salmonella monocytogenes in dairy products down to 5 × 101 CFU/g. Therefore, AuNPs-SD-PMA-qPCR is valuable for the simultaneous detection of Listeria monocytogenes and Salmonella in food products.

Link: https://doi.org/10.1016/j.foodcont.2024.110711