Osaka Institute of Public Health.
Biol Pharm Bull. 2024;47(11):1931-1936. doi: 10.1248/bpb.b24-00352.
Escherichia coli O157:H7 and Salmonella spp. are common foodborne pathogens. Simple, rapid and accurate methods to detect and enumerate these pathogens are required to prevent outbreaks of foodborne illness. Here, a microfluidic system with on-chip staining and semi-automated counting functionality was combined with the use of immunomagnetic separation to collect E. coli O157:H7 and Salmonella Typhimurium without an enrichment step. The recovery of bacteria from lettuce at different spiking ratios of the two species was 61-83%. In the range 3.5 × 10 to 3.3 × 10 cells/g of lettuce, there was a good linear relationship (R = 0.9997-0.9998) between the average counts from the microfluidic quantification method and conventional immunofluorescence microscopy. Detection took <3 h. The limit of detection of the microfluidic device was 4 × 10 cells/g, comparable to that of plate culture and real-time PCR methods. Our microfluidic approach has potential for rapid on-site detection of multiple pathogenic bacteria in foods.
大肠杆菌 O157:H7 和沙门氏菌属是常见的食源性病原体。需要简单、快速和准确的方法来检测和计数这些病原体，以防止食源性疾病的爆发。在这里，我们将具有芯片上染色和半自动化计数功能的微流控系统与免疫磁分离结合使用，无需进行富集步骤即可收集大肠杆菌 O157:H7 和肠炎沙门氏菌。从生菜中回收两种细菌的回收率为 61-83%。在生菜中两种细菌的浓度为 3.5×10 到 3.3×10 个细胞/g 的范围内，微流控定量方法的平均计数与传统免疫荧光显微镜之间存在良好的线性关系（R=0.9997-0.9998）。检测时间<3 小时。微流控装置的检测限为 4×10 个细胞/g，与平板培养和实时 PCR 方法相当。我们的微流控方法有可能快速现场检测食品中的多种致病菌。
