Interactions between Listeria monocytogenes and food-associated or environmental bacteria are critical not only for the growth but also for a number of key biological processes of the microorganism. In this regard, limited information exists on the impact of other microorganisms on the virulence of L. monocytogenes. In this study, the growth of L. monocytogenes was evaluated in a single culture or in coculture with L. innocua, Bacillus subtilis, Lactobacillus plantarum, or Pseudomonas aeruginosa in tryptic soy broth (10°C/10 days and 37°C/24 h). Transcriptional levels of 9 key virulence genes (inlA, inlB, inlC, inlJ, sigB, prfA, hly, plcA, and plcB) and invasion efficiency and intracellular growth in Caco-2 cells were determined for L. monocytogenes following growth in mono- or coculture for 3 days at 10°C or 9 h at 37°C. The growth of L. monocytogenes was negatively affected by the presence of L. innocua and B. subtilis, while the effect of cell-to-cell contact on L. monocytogenes growth was dependent on the competing microorganism. Cocultivation affected the in vitro virulence properties of L. monocytogenes in a microorganism-specific manner, with L. innocua mainly enhancing and B. subtilis reducing the invasion of the pathogen in Caco-2 cells. Assessment of the mRNA levels of L. monocytogenes virulence genes in the presence of the four tested bacteria revealed a complex pattern in which the observed up- or downregulation was only partially correlated with growth or in vitro virulence and mainly suggested that L. monocytogenes may display a microorganism-specific transcriptional response.

中文翻译：

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李斯特菌李斯特菌适应性，体外毒力和毒力相关基因转录响应不同微生物的存在的差异调制。

单核细胞增生李斯特菌与食物相关或环境细菌之间的相互作用不仅对于微生物的生长至关重要，而且对微生物的许多关键生物学过程也至关重要。在这方面，关于其他微生物对单核细胞增生李斯特氏菌毒力的影响的信息有限。在这项研究中，在胰蛋白酶大豆肉汤中（10°C / 10天和37°C / 24），在单一培养物中或与无毒李斯特菌，枯草芽孢杆菌，植物乳杆菌或铜绿假单胞菌共培养中评估了单核细胞增生李斯特菌的生长。H）。9个关键毒力基因（inlA，inlB，inlC，inlJ，SIGB，PRFA，hly启动，PLCA，和plcB基因）和Caco-2细胞侵袭效率和细胞内生长的测定李斯特菌以下在10℃下在单生长或共培养3天或在9ħ 37℃。单核细胞增生李斯特氏菌的生长受到无毒李斯特菌和枯草芽孢杆菌的负面影响，而细胞间接触对单核细胞增生李斯特氏菌生长的影响取决于竞争微生物。共培养影响了体外的毒力特性单核细胞增生李斯特氏菌以微生物特异的方式出现，其中无毒李斯特菌主要增强枯草芽孢杆菌，而枯草芽孢杆菌则减少了病原体在Caco-2细胞中的入侵。在四种被测细菌的存在下，对单核细胞增生李斯特菌毒力基因mRNA水平的评估揭示了一种复杂的模式，其中观察到的上调或下调仅与生长或体外毒力部分相关，并且主要表明单核细胞增生李斯特菌可能显示微生物特异性转录反应。