Development of rapid detection method of viable Escherichia coli and coli-form

制备了3株抗大肠杆菌的单抗。其中，单抗-C对大肠杆菌的特异性最强。该单抗与产气肠杆菌、肺炎克雷伯菌、普通变形杆菌、粘质沙雷氏菌、鼠伤寒沙门氏菌等细菌均无反应。作为建立活细胞快速检测的初步实验，对用膜过滤器收集的大肠杆菌进行了ATP检测。通过光发射检测，检测到约10^4CFU的大肠杆菌。用过氧化物酶标记的MAb-C处理同一膜，与鲁米诺溶液反应后测量发光(MAb法)。用单抗试验检测到约10^3CFU的大肠杆菌。当膜在35ﾟC的营养肉汤中孵育6小时时，两种方法都能在1cfu的条件下检测到大肠杆菌。初始细胞数与滤光片上的总发光计数或总发光点数有很强的相关性。总发光数和总发光点的相关系数分别为0.95和0.89。在单抗检测的情况下，初始细胞数与总发光点之间的相关性不是很强(r=0.76)。进一步的工作正在进行中，以获得更具特异性的抗大肠杆菌单抗。

Three anti-E.coli monoclonal antibodies were prepared. Among them, MAb-C was most specific to E.coli. The MAb did not react with other bacteria such as Enterobacter aerogenes, Klebsiella pneumoniae, Proteus vulgaris, Serratia marcescens, and Salmonella typhimurium. As a preliminary experiment to develop rapid detection of viable cells, ATP assay was performed on E.coli harvested on a membrane filter. By measuring light emission, about 10^4 CFU of E.coli was detected. The same membrane was treated with peroxidase-labeled MAb-C and light emission was measured after reaction with luminol solution (MAb assay). About 10^3 CFU of E.coli were detected with the Mab assay. When the membrane was incubated in Nutrient broth for 6 hr at 35ﾟC , E.coli was detected at 1 CFU by both methods. Initial cell nember and total light emission counts or total light emission points on the filter was strongly correlated. Correlation coefficients were calculated to be 0.95 and 0.89, respectively, for total light emission counts and total light emission points. In the case of MAb assay, correlation was not so strong between initial cell number and total light emission points (r=0,76). Further work is under way to obtain more specific MAb to E.coli.