直接ELISA检测沙门氏菌方法的建立及其应用研究

A Direct ELISA for the Detection of Salmonella spp.inDifferent Specimens

从已获得的４株沙门氏菌属特异杂交瘤单克隆抗体中，筛选出ＣＢ８和ｄｅ７两株单抗组合成酶标检测试剂，并建立了检测沙门氏菌的直接ＥＬＩＳＡ方法。它能检出沙门氏菌属９９％的菌株，而不与其他肠道杆菌反应（包括大肠杆菌、阴沟杆菌、产气杆菌、志贺氏菌、枸椽酸杆菌、克雷伯氏菌、变形杆菌和沙雷氏菌）。应用本方法检测粪样、鱼粉、奶样，其敏感性和特异性分别高达１００％和９７．６％，仅出现２．４％的假阳性率。该法不受各种样品成分的影响，而且在２～３ｄ即可完成样品筛选。直接ＥＬＩＳＡ具有快速简便、易于推广的优点，有重要实用价值。

A direct ELISA based on monoclonal antibodies(McAbs )for the rapiddetection of Salmonella spp.in specimens of food and faeces was developed. TwoMcAbs,CB8 and de7 complemented cach other in terms of binding reactivities with dif-ferent serovar from Group O2(A)to O67 of the Genus Salmonella were used in this sys-tem。 It takes several days to detect Salmonella organisms in specimens with convention-almethod,whereas thedirect ELISA can finish the detection within 6 hours.Tbe testwas sensitive and specific ,showing virtually no cross reactivity to other organisms inthe Family Enterobacteriaceac. After selective enrichment,additional to post enrichment(M-broth),it can eliminate the higher optical density baseline value of certain samples。As the presence of other organisms, such as E. coli, were 100 times greater thanSalmonella,it had no effect on the reaction. 870 specimens was tested by the directELISA,as compared with the standard culture method,the sensitivity and specificity ofthe direct ELISA were 100% and 97.9%。 These results showed that the direct ELISAmay serve as a useful and rapid screen method for the detection of Salmonella in foods,feeding stuffs or clinical specimens。