School of Health Science and Engineering, University of Shanghai for Science and Technology, Shanghai 200093, Shanghai, China; School of Food and Drugs, Shanghai Zhongqiao Vocational and Technical University, Shanghai 201514, Shanghai, China.
School of Health Science and Engineering, University of Shanghai for Science and Technology, Shanghai 200093, Shanghai, China.
Food Res Int. 2022 Jun;156:111143. doi: 10.1016/j.foodres.2022.111143. Epub 2022 Mar 16.
Listeria monocytogenes is a gram-positive pathogen, that usually adheres to stainless steel (SS), and other abiotic surfaces in food processing that undergo repeated cleaning and cause the spread of Listeria. Through the enumeration of biofilm cells, extracellular polymeric substance (EPS) component and the scanning electron microscopy (SEM) analysis of biofilms, it was found that the ratio of cells and extracellular matrix is affected by nutrition status. Regardless of the temperature, all strains exhibited a higher adhesion ability when exposed to 10-fold diluted TSB-YE (DTSB-YE, nutrition deficiency). Three hour initial adhesion was significantly positively correlated with biofilm formation (p＜0.01). DTSB-YE enhances initial attachment and subsequently promotes biofilm formation. The SEM analysis also showed that in DTSB-YE the adhesion and covered area of the attached cells were higher than those in TSB-YE (rich media). The amount of both extracellular polysaccharides and proteins was significantly higher when incubated in DTSB-YE than TSB-YE. The highest biofilm formation of Lm83 was observed in DTSBYE independent of temperature. The effects of nutrition deficiency on the expression of critical biofilm-associated genes of Lm 83 planktonic and biofilm cells were measured. The gene expression levels of inlA and sigB in biofilm cells in TSB-YE and DTSB-YE were approximately 95.7% and 88.0% and 42.2% and 45.7% lower than those in planktonic cells, respectively. However, the expression of inlA in DTSB-YE was significantly higher (p＜0.05) than that in TSB-YE for the same cell state. Interestingly, the gene expression of motB was considerably higher in DTSB-YE than in TSBYE, regardless of the state. These results indicate that better cell motility in nutrient deficiencies might facilitate the cell aggression to promote biofilm formation.
李斯特菌 monocytogenes 是一种革兰氏阳性病原体，通常附着在不锈钢 (SS) 和食品加工中的其他非生物表面上，这些表面会经历反复的清洁，导致李斯特菌的传播。通过对生物膜细胞的计数、细胞外聚合物质 (EPS) 成分和生物膜的扫描电子显微镜 (SEM) 分析，发现细胞和细胞外基质的比例受到营养状态的影响。无论温度如何，所有菌株在暴露于 10 倍稀释 TSB-YE（DTSB-YE，营养缺乏）时表现出更高的粘附能力。三小时初始粘附与生物膜形成呈显著正相关（p＜0.01）。DTSB-YE 增强初始附着，随后促进生物膜形成。SEM 分析还表明，在 DTSB-YE 中，附着细胞的粘附和覆盖面积高于 TSB-YE（富营养培养基）。在 DTSB-YE 中孵育时，细胞外多糖和蛋白质的量明显高于 TSB-YE。无论温度如何，Lm83 的生物膜形成量在 DTSBYE 中最高。测量了营养缺乏对 Lm 83 浮游和生物膜细胞关键生物膜相关基因表达的影响。在 TSB-YE 和 DTSB-YE 中，生物膜细胞中 inlA 和 sigB 的基因表达水平分别比浮游细胞低约 95.7%和 88.0%和 42.2%和 45.7%。然而，在相同的细胞状态下，DTSB-YE 中 inlA 的表达明显高于 TSB-YE（p＜0.05）。有趣的是，无论细胞状态如何，DTSB-YE 中 motB 的基因表达都明显高于 TSBYE。这些结果表明，在营养缺乏时，更好的细胞迁移能力可能有助于细胞侵袭，促进生物膜形成。
