免疫磁分离法高效富集牛奶中大肠杆菌O157:H7

Efficient enrichment of Escherichia coli O157:H7 in milk based on immunomagnetic separation

中文关键词:  大肠杆菌O157:H7  纳米磁珠  免疫磁分离  牛奶

英文关键词:Escherichia coli O157:H7  magnetic nanobeads  immunomagnetic separation  milk

中文摘要:

      目的 建立一种免疫磁分离(immunomagnetic separation, IMS)方法高效富集大肠杆菌O157:H7。方法 合成一种核壳型的纳米磁珠(magnetic nanobeads, MNBs), 并基于制备的MNBs构建了IMS。通过优化制备免疫MNBs时抗体浓度, IMS过程免疫MNBs的用量和孵育时间, 构建了高效的IMS方法。结果 构建的IMS方法能够在35 min内完成牛奶中大肠杆菌O157:H7的高效富集, 当大肠杆菌O157:H7浓度低于105 CFU/mL时, 捕获效率高于93.4%, 当菌浓度达到107 CFU/mL, 捕获效率仍大于50%。结论 该方法简单高效, 可被广泛应用于其他食源性致病菌检测的样品前处理。

英文摘要:

      Objective To establish a method for efficient enrichment of the Escherichia coli O157:H7 (E. coli O157:H7) by immunomagnetic separation (IMS). Methods The core-shell magnetic nanobeads (MNBs) were synthesized, and then the IMS was constructed based on the as-prepared MNBs. An efficient IMS method was constructed by optimizing the concentration of antibody in the preparation of immunomagnetic nanobeads (IMNBs), the amount of IMNBs immunized in IMS process and the incubation time. Results The constructed IMS method could complete the efficient enrichment of E. coli O157:H7 in milk within 35 min. When the concentration of E. coli O157:H7 was lower than 105 CFU/mL, the capture efficiency was higher than 93.4%. When the bacterial concentration reached 107 CFU/mL, the capture efficiency was still greater than 50%. Conclusion This method is simple and efficient, and can be widely used for sample pretreatment of other food-borne pathogens.