Salmonella spp. is a high-risk bacterial pathogen that is monitored in imported animal-derived feedstuffs. Serratia fonticola is the bacterial species most frequently confused with Salmonella spp. in traditional identification methods based on biochemical characteristics, which are time-consuming and labor-intensive, and thus unsuitable for daily inspection and quarantine work. In this study, we established a duplex real-time qPCR method with invA- and gyrB-specific primers and probes corresponding to Salmonella spp. and S. fonticola. The method could simultaneously detect both pathogens in imported feedstuffs, with a minimum limit of detection for Salmonella spp. and S. fonticola of 197 copies/μL and 145 copies/μL, respectively (correlation coefficient R² = 0.999 in both cases). The amplification efficiency for Salmonella spp. and S. fonticola was 98.346% and 96.49%, respectively. Detection of fishmeal was consistent with method GB/T 13091-2018, and all seven artificially contaminated imported feed samples were positively identified. Thus, the developed duplex real-time qPCR assay displays high specificity and sensitivity, and can be used for the rapid and accurate detection of genomic DNA from Salmonella spp. and S. fonticola within hours. This represents a significant improvement in the efficiency of detection of both pathogens in imported feedstuffs.

沙门氏菌属。是一种高风险细菌病原体，在进口的动物饲料中进行监控。沙雷氏菌是最经常与沙门氏菌（Salmonella spp）混淆的细菌。传统的基于生化特性的鉴定方法耗时且费力，因此不适合日常检查和检疫工作。在这项研究中，我们建立了invA和gyrB特异性引物和对应于沙门氏菌属的探针的双链实时qPCR方法。和S. fonticola。该方法可以同时检测进口饲料中的两种病原体，最低检出限为沙门氏菌属。和S. fonticola分别为197拷贝/μL和145拷贝/μL（ 两种情况下的相关系数R ² = 0.999）。沙门氏菌的扩增效率。和S. fonticola分别为98.346％和96.49％。鱼粉的检测与GB / T 13091-2018方法一致，并且对所有七个人工污染的进口饲料样品进行了阳性鉴定。因此，开发的双工实时qPCR测定法显示出高特异性和敏感性，可用于快速准确地检测沙门氏菌属的基因组DNA 。和S. fonticola在几个小时内。这代表了进口饲料中两种病原体检测效率的显着提高。