基于环介导恒温扩增技术的大肠杆菌O157:H7快速检测试剂盒的评价

【目的】评价基于环介导恒温扩增技术(LAMP)的大肠杆菌O157:H7(Escherichia coli O157:H7)快速检测试剂盒的实效性。【方法】测定快速检测试剂盒的特异性、灵敏度、重复性、保质期以及运输稳定性,并与传统方法对比检测实际样品。【结果】大肠杆菌O157:H7标准菌株样品均检测为阳性,非大肠杆菌O157:H7标准菌株样品均检测为阴性,未发现有交叉反应;试剂盒最低检验限为29 CFU;该试剂盒的特异性、灵敏度及准确度与传统方法相比具有较高的一致性;试剂盒对高菌量目标菌和阴性菌样品的检测重复率均为100%,对低菌量目标菌样品的批间检测重复率为94%。试剂盒可在4°C保存9个月以上,并且可进行变温储存72 h以上。【结论】该试剂盒特异性好,灵敏度高,重复性好,储存方便,检测结果稳定、可靠,适用于对食品中大肠杆菌O157:H7的检测需求。

Evaluation of loop-mediated isothermal amplification based kits for rapid detection of Escherichia coli O157:H7

Objective] To evaluate the efficacy of loop-mediated isothermal amplification (LAMP) based kits for rapid detection of Escherichia coli O157:H7. Methods] Specificity, sensitivity, repeatability and stability of the kits were evaluated, and the result detected by LAMP kits was compared with the detection result by traditional microbiological detection method in practical samples. Results] All E. coli O157:H7 standard strain samples were detected positive, while all non-E. coli O157:H7 samples were detected negative, showing that the detection had no cross reaction. The minimum test limit of the kit was 29 CFU. Detection specificity, accuracy and sensitivity of the kit were preeminent, and the detection result was highly consistent with that obtained by traditional microbiological detection method. The detecting repetition rate for high concentration of target bacteria and negative bacteria samples detected by the kits was 100%, and the inter-batch testing repetition rate for low concentration of target bacteria samples was 94%. This kit could be preserved for more than 9 months at 4 °C, and it remained its efficacy after a variable temperature storage for more than 72 h. Conclusion] The kit has high specificity, sensitivity, repeatability and easy storage characteristics, which make it applicable for rapid detection of E. coli O157:H7.