State Key Laboratory of Food Science and Technology, Nanchang University, Nanchang, 330047, PR China.
State Key Laboratory of Food Science and Technology, Nanchang University, Nanchang, 330047, PR China; Jiangxi Institute for Food Control, Nanchang, 330001, PR China.
Anal Biochem. 2022 Jun 1;646:114647. doi: 10.1016/j.ab.2022.114647. Epub 2022 Mar 12.
Salmonella infection could come from eating contaminated meat or raw eggs, and drinking milk or water contaminated by Salmonella enteritidis. Therefore, it is necessary to explore a fast and easy method for the detection of S. enteritidis in these diverse samples. For this purpose, a novel particle size sensing tool was designed for ultrasensitive and accurate S. enteritidis detection. This assay consisted of rolling circle amplification (RCA) with dynamic light scattering (DLS) using gold nanoparticles (AuNPs) modified with DNA probe as DNA-AuNPs as the capture surface into a hybrid RCA-DLS assay combined with asymmetric polymerase chain reaction (aPCR) and subsequent detection. Under optimal experimental conditions, the novel hybrid RCA-DLS assay combined with aPCR for S. enteritidis reached a limit of detection (LOD) as low as 3 × 10 CFU/mL in pure culture. In spiked milk samples, the LOD was 2.0 × 10 CFU/mL without pre-enriched bacteria. The total time of RCA-DLS assay was about 6 h which including genomic DNA extraction, aPCR, RCA and DLS determination. The hybrid RCA-DLS assay combined with aPCR holds promise in the specific and sensitive S. enteritidis detection.
沙门氏菌感染可能来自食用受污染的肉类或生鸡蛋，以及饮用受肠炎沙门氏菌污染的牛奶或水。因此，有必要探索一种在这些不同样本中快速、简便的方法来检测肠炎沙门氏菌。为此，设计了一种新型的粒径传感工具，用于超灵敏和准确地检测肠炎沙门氏菌。该测定法由滚环扩增（RCA）与使用 DNA 探针修饰的金纳米粒子（AuNPs）的动态光散射（DLS）组成，DNA-AuNPs 作为 DNA-AuNPs 作为捕获表面，结合不对称聚合酶链反应（aPCR）和后续检测，形成杂交 RCA-DLS 测定法。在最佳实验条件下，新型杂交 RCA-DLS 测定法结合 aPCR 对肠炎沙门氏菌的检测限（LOD）低至纯培养物中的 3×10 CFU/mL。在添加牛奶样品中，未经预富集细菌的 LOD 为 2.0×10 CFU/mL。RCA-DLS 测定法的总时间约为 6 小时，包括基因组 DNA 提取、aPCR、RCA 和 DLS 测定。该杂交 RCA-DLS 测定法结合 aPCR 有望用于肠炎沙门氏菌的特异性和敏感性检测。
