基于双球信号放大的大肠杆菌O157H7免疫HCR检测方法

Detection method of immune HCR signal amplification of Escherichia coli O157:H7 based on double microspheres

快速准确的检测大肠杆菌O157:H7对食品安全及食源性疾病的早期诊治具有重要意义,免疫学检测方法具有特异性好、操作简便等优点成为最常见的快速检测方法之一,然而灵敏度低限制了其在食源性致病菌检测中的应用。研究将免疫学与HCR相结合建立一种免疫HCR方法检测大肠杆菌O157:H7,并采用双球策略规避了由于抗体与引发链同时标记在同一乳胶微球上存在相互干扰的问题,降低了抗体(mAb)对引发链的干扰,提高引发效率和检测方法的灵敏度。与基于单球的免疫HCR的灵敏度(2.7×10^3 CFU·mL^-1)相比,本方法中基于双球的免疫HCR的灵敏度(4.8×10^2 CFU·mL^-1)提高了5.6倍。

Rapid and accurate detection of Escherichia.coli O157H7(E.coli O157H7)is of great significance for food safety and early diagnosis and treatment of food-borne diseases.The immunological detection method has the advantages of good specificity and simple operation,becoming one of the most common rapid detection methods.However,its low sensitivity limits its application in the detection of food-borne pathogenic bacteria.The study combined immunology with HCR to establish an immune HCR detection method for E.coli O157H7.In addition,the two-sphere strategy was adopted to avoid the mutual interference between the antibody and the trigger chain labeled on the same latex microsphere,and to reduce the interference of the antibody(mAb)on the trigger chain,so as to improve the initiation efficiency and the sensitivity of the detection method.The sensitivity of the immune HCR based on the single sphere(2.7×10^3 CFU·mL^-1)was 5.6 times higher than that based on the single sphere(4.8×10^2 CFU·mL^-1).