为了建立一种能快速、灵敏、特异检测鼠伤寒沙门氏菌(Salmonella typhimurium，ST)的方法，本研究以荧光微球(FM)为标记物建立了荧光微球免疫层析检测法(FM-ICA)，将羧基化的磁性微球与抗体偶联制备了抗-ST免疫磁珠(IMB)，并将FM-ICA与IMB联合用于富集和检测三种食品样本中的ST。在优化条件下，FM-ICA检测的线性范围为3.16×106~2×109 CFU/mL，回收率为80%~120%，变异系数均小于5%。当菌液浓度大于1×108 CFU/mL时，结果显示与同属沙门氏菌的交叉反应；而当菌液浓度小于或等于1×108 CFU/mL时，常见的12株非目标菌检测结果为阴性，特异性较好。FM-ICA+IMB联合检测三种模拟食品时的回收率为38%~55%，其中，西红柿对回收率影响较小，鸡蛋和猪肉影响较大。然而，联合检测的灵敏度可达到1×105 CFU/mL，比单一FM-ICA方法提高了30倍，同时，整个检测过程可在2 h内完成。本检测方法的建立对于快速筛查鼠伤寒沙门氏菌具有重要意义。

Immunochromatography assay (ICA) was established in this study by using fluorescent microspheres (FMs) as the probe to obtain a rapid, sensitive and specific method for the detection of Salmonella typhimurium (ST). Anti- ST immunomagnetic beads (IMB) was prepared by coupling magnetic carboxyl-microspheres with antibodies, and FM-ICA was combined with IMB for enrichment and detection of ST in three food samples. Under optimal conditions, the linear range of FM-ICA was 3.16×106 ~ 2×109 CFU/mL with the recovery of 80% ~ 120%, and the coefficient of variation was less than 5%. The results showed a cross-reaction with Salmonella when the concentration of bacteria was more than 1×108 CFU/mL , and the test results of other 12 non-target bacteria were negative when the concentration was less than 1×108 CFU/mL.. The recoveries of three simulated foods by FM-ICA+IMB were 38%~55%. Thetomato samples had little effect on the recovery while eggs and pork showed significant effectson the recovery. In addition, the sensitivity of the combined method could be 1×105 CFU/mL, which was a 30 times higher than that of FM-ICA method, and the detection process could be completed within 2 hours. The combined method established in this study was of great significance for rapid screening of Salmonella typhimurium.

“十二五”国家科技支撑计划项目（2012BAK08B07）；广东省科技计划项目（2017A020208014）