School of Pharmacy and Food Science, Zhuhai College of Science and Technology, Zhuhai 519041, China.
School of Environmental Ecology and Biological Engineering, Wuhan Institute of Technology, Wuhan 430205, China.
Molecules. 2023 Aug 3;28(15):5835. doi: 10.3390/molecules28155835.
O157:H7, , and are major foodborne pathogens that are widespread in nature and responsible for several outbreaks of food safety accidents. Thus, a rapid and practical technique (PMA-mPCR) was developed for the simultaneous detection of viable O157:H7, , and in pure culture and in a food matrix. To eliminate false positive results, propidium monoazide (PMA) was applied to selectively suppress the DNA amplification of dead cells. The results showed the optimum concentration of PMA is 5.0 µg/mL. The detection limit of this assay by mPCR was 10 CFU/mL in the culture broth, and by PMA-mPCR was 10 CFU/mL both in pure culture and a food matrix (milk and ground beef). In addition, the detection of mixed viable and dead cells was also explored in this study. The detection sensitivity ratio of viable and dead counts was less than 1:10. Therefore, the PMA-mPCR assay proposed here might provide an efficient detection tool for the simultaneous detection of viable O157:H7, , and and also have great potential for the detection and concentration assessment of VBNC cells.
O157:H7、、和是广泛存在于自然界中的主要食源性致病菌，它们引发了多起食品安全事故。因此，开发了一种快速实用的技术（PMA-mPCR），用于在纯培养物和食品基质中同时检测活的 O157:H7、、和。为了消除假阳性结果，应用了碘化丙啶（PMA）来选择性地抑制死细胞的 DNA 扩增。结果表明，PMA 的最佳浓度为 5.0 µg/mL。该 mPCR 检测方法在培养肉汤中的检测限为 10 CFU/mL，在纯培养物和食品基质（牛奶和碎牛肉）中的检测限为 10 CFU/mL。此外，本研究还探索了混合活菌和死菌的检测。活菌和死菌计数的检测灵敏度比小于 1:10。因此，这里提出的 PMA-mPCR 检测方法可能为同时检测活的 O157:H7、、和提供一种有效的检测工具，并且对于 VBNC 细胞的检测和浓度评估也具有很大的潜力。
