Hunan Key Laboratory of Forestry Edible Resources Safety and Processing, National Engineering Research Center of Rice and Byproducts Deep Processing, College of Food Science and Engineering, Central South University of Forestry and Technology, Changsha, Hunan, 410004, China.
Institute of Translational Medicine, Nanchang University, Nanchang, 330031, China.
Biosens Bioelectron. 2024 Nov 15;264:116661. doi: 10.1016/j.bios.2024.116661. Epub 2024 Aug 13.
As a foodborne pathogen capable of causing severe illnesses, early detection of Escherichia coli O157:H7 (E. coli O157:H7) is crucial for ensuring food safety. While Förster resonance energy transfer (FRET) is an efficient and precise detection technique, there remains a need for amplification strategies to detect low concentrations of E. coli O157:H7. In this study, we presented a phage (M13)-induced "one to many" FRET platform for sensitively detecting E. coli O157:H7. The aptamers, which specifically recognize E. coli O157:H7 were attached to magnetic beads as capture probes for separating E. coli O157:H7 from food samples. The peptide O157S, which specifically targets E. coli O157:H7, and streptavidin binding peptide (SBP), which binds to streptavidin (SA), were displayed on the P3 and P8 proteins of M13, respectively, to construct the O157S-M13K07-SBP phage as a detection probe for signal output. Due to the precise distance (≈3.2 nm) between two neighboring N-terminus of P8 protein, the SA-labeled FRET donor and acceptor can be fixed at the Förster distance on the surface of O157S-M13K07-SBP via the binding of SA and SBP, inducing FRET. Moreover, the P8 protein, with ≈2700 copies, enabled multiple FRET (≈605) occurrences, amplifying FRET in each E. coli O157:H7 recognition event. The O157S-M13K07-SBP-based FRET sensor can detect E. coli O157:H7 at concentration as low as 6 CFU/mL and demonstrates excellent performance in terms of selectivity, detection time (≈3 h), accuracy, precision, practical application, and storage stability. In summary, we have developed a powerful tool for detecting various targets in food safety, environmental monitoring, and medical diagnosis.
作为一种能够引起严重疾病的食源性病原体，早期检测大肠杆菌 O157:H7（E. coli O157:H7）对于确保食品安全至关重要。虽然Förster 共振能量转移（FRET）是一种高效、精确的检测技术，但仍需要扩增策略来检测低浓度的大肠杆菌 O157:H7。在本研究中，我们提出了一种噬菌体（M13）诱导的“一到多”FRET 平台，用于灵敏地检测大肠杆菌 O157:H7。特异性识别大肠杆菌 O157:H7 的适体被连接到磁性珠上作为捕获探针，用于从食物样品中分离大肠杆菌 O157:H7。特异性针对大肠杆菌 O157:H7 的肽 O157S 和与链霉亲和素（SA）结合的肽（SBP）分别展示在 M13 的 P3 和 P8 蛋白上，以构建作为信号输出的检测探针的 O157S-M13K07-SBP 噬菌体。由于两个相邻 P8 蛋白的 N 末端之间的精确距离（≈3.2nm），SA 标记的 FRET 供体和受体可以通过 SA 和 SBP 的结合固定在 O157S-M13K07-SBP 表面的 Förster 距离上，从而诱导 FRET。此外，具有≈2700 个拷贝的 P8 蛋白可以实现多个 FRET（≈605）发生，在每个大肠杆菌 O157:H7 识别事件中放大 FRET。基于 O157S-M13K07-SBP 的 FRET 传感器可以检测到低至 6 CFU/mL 的大肠杆菌 O157:H7，并且在选择性、检测时间（≈3 小时）、准确性、精密度、实际应用和存储稳定性方面表现出优异的性能。总之，我们开发了一种用于检测食品安全、环境监测和医疗诊断中各种靶标的强大工具。
