Salmonella is one of major foodborne pathogens and the leading cause of foodborne illness-related hospitalizations and deaths. It is critical to develop a sensitive and rapid detection assay that can identify Salmonella to ensure food safety. In this study, a DNA sensor-based suspension array system of high multiplexing ability was developed to identify eight Salmonella serovars commonly associated with foodborne outbreaks to the serotype level. Each DNA sensor was prepared by activating pre-encoded microspheres with oligonucleotide probes that are targeting virulence genes and serovar-specific regions. The mixture of 12 different types of DNA sensors were loaded into a 96-well microplate and used as a 12-plex DNA sensor array platform. DNA isolated from Salmonella was amplified by multiplex polymerase chain reaction (mPCR), and the presence of Salmonella was determined by reading fluorescent signals from hybridization between probes on DNA sensors and fluorescently labeled target DNA using the Bio-Plex® system. The developed multiplex array was able to detect synthetic DNA at the concentration as low as 100 fM and various Salmonella serovars as low as 100 CFU/mL within 1 h post-PCR. Sensitivity of this assay was further improved to 1 CFU/mL with 6-h enrichment. The array system also correctly and specifically identified serotype of tested Salmonella strains without any cross-reactivity with other common foodborne pathogens. Our results indicate the developed DNA sensor suspension array can be a rapid and reliable high-throughput method for simultaneous detection and molecular identification of common Salmonella serotypes.

沙门氏菌是主要的食源性病原体之一，也是食源性疾病相关住院和死亡的主要原因。开发能够识别沙门氏菌的灵敏，快速的检测方法至关重要，以确保食品安全。在这项研究中，开发了一种具有高多重能力的基于DNA传感器的悬浮阵列系统，以鉴定通常与食源性暴发相关的八种沙门氏菌血清型。通过用靶向毒力基因和血清型特异性区域的寡核苷酸探针激活预编码的微球来制备每个DNA传感器。将12种不同类型的DNA传感器的混合物装入96孔微孔板中，并用作12重DNA传感器阵列平台。从中分离出的DNA沙门氏菌通过多重聚合酶链反应（mPCR）扩增，沙门氏菌的存在是通过使用Bio-Plex®系统读取DNA传感器上探针之间的杂交荧光信号和荧光标记的目标DNA来确定的。开发的多重阵列能够在PCR后1小时内检测低至100 fM的合成DNA和低至100 CFU / mL的多种沙门氏菌血清。通过6小时的富集，该测定的灵敏度进一步提高到1 CFU / mL。阵列系统还可以正确，明确地鉴定被测沙门氏菌的血清型与其他常见食源性病原体没有任何交叉反应性的菌株。我们的结果表明，开发的DNA传感器悬浮阵列可以是一种快速，可靠的高通量方法，用于同时检测和分子鉴定常见的沙门氏菌血清型。