PDF(Pubmed)
Abstract：
Current diagnostic methods for detecting foodborne pathogens are time-consuming, require sophisticated equipment, and have a low specificity and sensitivity. Magnetic nanoparticles (MNPs) and plasmonic/colorimetric biosensors like gold nanoparticles (GNPs) are cost-effective, high-throughput, precise, and rapid. This study aimed to validate the use of MNPs and GNPs for the early detection of Escherichia coli O157:H7, Salmonella enterica spp., Campylobacter jejuni, and Listeria monocytogenes in bovine fecal samples. The capture efficiency (CE) of the MNPs was determined by using Salmonella Typhimurium (ATCC_13311) adjusted at an original concentration of 1.5 × 108 CFU/mL. One (1) mL of this bacterial suspension was spiked into bovine fecal suspension (1 g of fecal sample in 9 mL PBS) and serially diluted ten-fold. DNA was extracted from Salmonella Typhimurium to determine the analytical specificity and sensitivity/LOD of the GNPs. The results showed that the CE of the MNPs ranged from 99% to 100% and could capture as little as 1 CFU/mL. The LOD of the GNPs biosensor was 2.9 µg/µL. The GNPs biosensor was also tested on DNA from 38 naturally obtained bovine fecal samples. Out of the 38 fecal samples tested, 81.6% (31/38) were positive for Salmonella enterica spp., 65.8% (25/38) for C. jejuni, 55.3% (21/38) for L. monocytogenes, and 50% (19/38) for E. coli O157:H7. We have demonstrated that MNP and GNP biosensors can detect pathogens or their DNA at low concentrations. Ensuring food safety throughout the supply chain is paramount, given that these pathogens may be present in cattle feces and contaminate beef during slaughter.
摘要：
目前检测食源性病原体的诊断方法耗时,需要先进的设备，特异性和敏感性较低。磁性纳米粒子（MNPs）和等离子/比色生物传感器（如金纳米粒子（GNPs））具有成本效益，高通量，精确，和快速。本研究旨在验证MNPs和GNPs在早期检测大肠杆菌O157：H7，沙门氏菌中的应用。,空肠弯曲杆菌,牛粪便样本中的单核细胞增生李斯特菌。通过使用以1.5X108CFU/mL的原始浓度调节的鼠伤寒沙门氏菌(ATCC_13311)测定MNPs的捕获效率(CE)。将一(1)mL该细菌悬浮液掺加到牛粪便悬浮液(在9mLPBS中的Ig粪便样品)中并连续稀释十倍。从鼠伤寒沙门氏菌中提取DNA以确定GNP的分析特异性和灵敏度/LOD。结果表明，MNPs的CE范围为99％至100％，可以捕获低至1CFU/mL。GNPs生物传感器的LOD为2.9µg/µL。还在来自38个天然获得的牛粪便样品的DNA上测试了GNP生物传感器。在测试的38个粪便样本中，81.6%(31/38)为肠沙门氏菌阳性。,空肠弯曲菌65.8%(25/38)，55.3%（21/38）为单核细胞增生李斯特菌，和50%(19/38)的大肠杆菌O157:H7。我们已经证明MNP和GNP生物传感器可以在低浓度下检测病原体或其DNA。确保整个供应链的食品安全至关重要，鉴于这些病原体可能存在于牛的粪便中，并在屠宰过程中污染牛肉。
