流式细胞术检测单增李斯特菌与酿酒酵母

Detection of Saccharomyces cerevisiae and Listeria monoeytogenes by Flow Cytometry

摘要:

为探讨流式细胞术对单增李斯特菌和酿酒酵母的活菌与热灭活菌的检出效果，本文采用荧光染色试剂SYTO-9和碘化乙锭（PI）对单增李斯特菌和酿酒酵母的活菌与热灭活菌的细胞悬液进行染色，采用流式细胞仪同时测量红色荧光与绿色荧光从而得出细胞悬液中的细菌和酵母的含量。结果表明经核酸荧光染料染色后，再结合流式细胞术对细菌与酵母菌进行检测，步骤简单、耗时短。该法不仅简化了测量步骤且分辨率高，对单增李斯特菌和酿酒酵母均具有良好的检出结果，能分辨同一体系中同一菌种的活细胞与热灭活细胞和同一体系中的细菌与酵母活细胞；该法检出限低，将单增李斯特菌稀释后，最低检出限可达1.2×104 cells/mL，将酿酒酵母稀释后，最低检出限可达6×103 Cells/mL，因此能大大缩短增菌时间或者避免繁复的增菌步骤。

Abstract:

The viable and heat-treated microorganisms such as Listeria monocytogenes and Saccharomyces cerevisiae were investigated in this study. They were stained by fluorescent staining reagents SYTO-9 and Propidium Iodide (PI) and then the red and green fluorescence signals were detected using flow cytometry to get the concentration of cells in samples. The results showed that flow cytometry was able to detect bacteria and yeast after the nucleic acid fluorescent staining. This method simplified the procedure for L. monocytogenes and S. cerevisiae detection, shortened the time of detection procedures, and also distinguished viable with heat-treated micrograms and viable bacteria with yeast in the same system. This method was capable of detecting as few as 1.2×104 cells/mL L. monocytogenes and 6 × 103 cells/mL S. cerevisiae. This improvement might shorten the time consuming of culture enrichment or simplify the process.