He Qiyi, Pan Junkang, Xu Zhihao, Hammock Bruce D, Li Dongyang
College of Biosystems Engineering and Food Science, Zhejiang University, Hangzhou 310058, People's Republic of China.
Department of Entomology and Nematology and UCD Comprehensive Cancer Center, University of California, Davis, Davis, California 95616, United States.
Food Chem. 2025 May 1;473:142987. doi: 10.1016/j.foodchem.2025.142987. Epub 2025 Jan 23.
Rapid and accurate detection of foodborne pathogens is crucial for food safety. E. coli O157:H7, a major foodborne pathogen, can cause severe illness even at low concentration, highlighting the necessity for effective detection methods. This study focuses on developing nanobodies specific to E. coli O157:H7, aiming to provide a more efficient, cost-effective, and stable analytical reagents which can be available internationally. An alpaca was immunized and a phage-displayed nanobody library was constructed. Following panning, nanobodies were expressed and characterized for their affinity and specificity. A nanobody-based immunoassay was developed, with a limit of detection of 8.7 × 10 cfu/mL. The matrix effect was evaluated, and the assay successfully detected E. coli O157:H7 in various food samples (with 5 cfu spiked), including ground beef, orange juice, and milk. The study developed a nanobody-based immunoassay for E. coli O157:H7 detection, underscoring the practical applicability of nanobodies for testing food safety monitoring.
快速准确地检测食源性病原体对食品安全至关重要。大肠杆菌O157:H7是一种主要的食源性病原体，即使在低浓度下也能导致严重疾病，这凸显了有效检测方法的必要性。本研究专注于开发针对大肠杆菌O157:H7的纳米抗体，旨在提供一种更高效、经济且稳定的分析试剂，该试剂可在国际上获得。对一只羊驼进行免疫并构建了噬菌体展示纳米抗体文库。经过淘选后，表达纳米抗体并对其亲和力和特异性进行表征。开发了一种基于纳米抗体的免疫测定方法，检测限为8.7×10 cfu/mL。评估了基质效应，该测定方法成功检测了各种食品样品（加标5 cfu）中的大肠杆菌O157:H7，包括碎牛肉、橙汁和牛奶。该研究开发了一种基于纳米抗体的免疫测定方法用于检测大肠杆菌O157:H7，强调了纳米抗体在食品安全监测检测中的实际适用性。
