Aerial, Illkirch, France.
Université Paris-Saclay, INRAE, AgroParisTech, Micalis Institute, Jouy-en-Josas, France.
Methods Mol Biol. 2025;2852:105-122. doi: 10.1007/978-1-0716-4100-2_7.
In food industry, Listeria monocytogenes contamination can occur accidentally despite the quality control of raw materials and factory. Decontamination processes or inhibitory effects of ingredients/additives in food products are set up to ensure compliance with hygiene and microbiological criteria. These actions represent stresses for the pathogenic agent, causing fluctuations in its physiological states. Moreover, during these environmental stresses, Listeria monocytogenes can enter in a viable but nonculturable (VBNC) state which is not detected by plate counting but by flow cytometry. This technique coupled with cell staining by fluorescent dyes offers the possibility to assess different physiological states based on different cellular parameters: enzymatic activity, transmembrane integrity, membrane potential, and respiratory activity. In this chapter, we present a method to assess the viability of foodborne pathogens using a double-staining principle based on the assessment of membrane integrity and intracellular esterase activity.
在食品工业中，尽管对原材料和工厂进行了质量控制，但李斯特菌污染仍可能偶然发生。为了确保符合卫生和微生物标准，建立了食品中成分/添加剂的去污过程或抑制作用。这些操作代表了对病原体的应激，导致其生理状态发生波动。此外，在这些环境应激下，李斯特菌可能进入存活但非可培养（VBNC）状态，这种状态无法通过平板计数检测，而只能通过流式细胞术检测。该技术与荧光染料对细胞进行染色相结合，提供了基于不同细胞参数评估不同生理状态的可能性：酶活性、跨膜完整性、膜电位和呼吸活性。在本章中，我们提出了一种使用基于膜完整性和细胞内酯酶活性评估的双重染色原理来评估食源性病原体活力的方法。
