Rapid detection of bacterial cells using photon correlation spectroscope technique on HACCP

我们开发了一种利用光子相关光谱仪(PCS)技术快速检测细菌细胞的新系统。1.超声振动去除细菌细胞为了去除海产品(鱼制品)表面的细菌细胞，使用超声波能量。超声波处理可以在5分钟内去除海鲜中几乎所有的细胞。应用流式细胞仪(FCM)技术测定水产品中微生物细胞总数。FCM测定的细胞数与传统的菌落计数法测定的细胞数在105-109个/g范围内具有良好的相关性，一次FCM检测可在60s内完成，包括微生物细胞的制备在内的总检测时间在30min内。2.应用PCS技术快速检测沙门氏菌细胞。该方法是基于沙门氏菌与抗沙门氏菌抗体反应的细胞能够通过PCS技术进行分析。当沙门氏菌细胞与抗体小球反应时，抗体小球的大小分布向更大范围移动。相比之下，在参比细菌细胞(大肠杆菌)中，大小分布几乎没有变化。这一现象被认为是由于抗体与沙门氏菌细胞发生选择性反应，它们与细菌细胞聚集在一起，分布尺寸增大。因此，使用PCS技术可以区分目标硝化细菌和其他细菌细胞香料。一次分析可在10min内完成，包括样品制备在内的PCS分析总时间在60min以内。

We developed new system for rapid detection of bacteria cells using photon correlation spectroscope (PCS) technique.1.Removal of bacterial cells by ultrasonic vibrationTo remove bacterial cells from the surface of seafood products (Surimi-based products, fish), ultrasonic energy was used. Almost of all cells can be removed from seafood in 5 min with ultrasonic treatment. Flow cytometry (FCM) technique applied to the determination of total number of microbial cells grown on seafood products. Cell numbers determined by FCM well paralleled that measured by traditional colony counting method in the range of 105-109 cells/g. One FCM assay could be completed within 60 sec and the total assay time including the preparation of microbial cells was within 30 min.2.Rapid detection of Salmonella cells by PCS techniqueRapid detection system for nitrifying bacteria was developed using PCS technique. The method is based on that Salmonella cells reacted with anti-Salmonella antibody were able to analyze by PCS technique. When Salmonella cells were reacted with the antibody beads, the size distribution was shifted to larger range. In contrast, in the reference bacterial cells (Escherichia coli), the size distribution shows little change. The phenomenon was assumed that since the antibody reacted with Salmonella cells selectively, they were aggregated with bacterial cells, and the distribution size increased. Thus, it is possible to discriminate between aimed nitrifying bacteria and other spices of bacterial cells using PCS technique. One assay could be completed in 10 min, and the total PCS assay time including sample preparation was within 60 min.