大肠杆菌O157胶体金免疫层析快速筛查方法的建立

目的建立一种大肠杆菌O157的胶体金免疫层析快速筛查方法。方法利用胶体金免疫层析技术,采用双抗体夹心法检测大肠杆菌O157,对该法进行敏感性、特异性和食品样品的适用性分析。结果该法能在15分钟内完成检测,检测不同的肠杆菌科细菌(非O157型大肠杆菌、沙门菌、志贺菌、变形杆菌、柠檬酸杆菌、肠杆菌、沙雷菌、耶尔森菌)、葡萄球菌、李斯特菌、气单胞菌、弧菌等共24种30株常见细菌,未发现有交叉反应,显示该法特异性良好。检测大肠杆菌O157的最低检出浓度为1×105cfu/ml。方法适用于奶粉、面粉、淀粉、咖啡粉、饼干、蛋糕、果冻、燕窝和果汁等食品样品的检测。结论新建立的大肠杆菌O157胶体金免疫层析试验简便、快速,特异性和灵敏度较好,适用于现场样品的快速筛查。

Development of a gold-immunochromatography test for rapid detecting E. coli O157

OBJECTIVE: To develop a method for rapid detecting Escherichia coli (E. coli) O157 on site. METHODS: A colloidal gold immunochromatography test based on double-antibody sandwich assay for detecting E. coli O157 was developed. Its sensitivity and specificity were then evaluated, and its feasibility of screening food samples were evaluated by analyzing various samples added with E. coli O157. RESULTS: Typical detecting time is less than 15 minutes per sample. The sensitivity of the test is 1 x 10(5) cfu/ml. No any cross-reaction with 30 strains of 24 species in Enterobacteriaceae (including non-O157 E. coli, Salmonella, Shigella, Proteus, Citrobacter, Enterobacter, Serratia and Yersinia), Staphylococus, Listeria, Aeromonas and Vibrios was found. The test could be used to detect E. coli O157 in various samples such as milk powder, flour, starch, coffee, biscuit, cake, jelly and juice. CONCLUSION: The gold-immunochromatography test appears to be a rapid, convenient, specific and sensitive test for detecting E. coli O157: H7 on site.