Agricultural University of Athens, Department of Food Science and Human Nutrition, Laboratory of Food Quality Control and Hygiene, Athens, Greece.
Agricultural University of Athens, Department of Food Science and Human Nutrition, Laboratory of Dairy Research, Athens, Greece.
Appl Environ Microbiol. 2020 Aug 18;86(17). doi: 10.1128/AEM.01165-20.
Interactions between 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 In this study, the growth of was evaluated in a single culture or in coculture with , , , or in tryptic soy broth (10°C/10 days and 37°C/24 h). Transcriptional levels of 9 key virulence genes (, , , , , , , , and ) and invasion efficiency and intracellular growth in Caco-2 cells were determined for following growth in mono- or coculture for 3 days at 10°C or 9 h at 37°C. The growth of was negatively affected by the presence of and , while the effect of cell-to-cell contact on growth was dependent on the competing microorganism. Cocultivation affected the virulence properties of in a microorganism-specific manner, with mainly enhancing and reducing the invasion of the pathogen in Caco-2 cells. Assessment of the mRNA levels of 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 virulence and mainly suggested that may display a microorganism-specific transcriptional response. is the etiological agent of the severe foodborne disease listeriosis. Important insight regarding the physiology and the infection biology of this microorganism has been acquired in the past 20 years. However, despite the fact that coexists with various microorganisms throughout its life cycle and during transmission from the environment to foods and then to the host, there is still limited knowledge related to the impact of surrounding microorganisms on ' biological functions. In this study, we showed that modulates specific biological activities (i.e., growth and virulence potential) as a response to coexisting microorganisms and differentially alters the expression of virulence-associated genes when confronted with different bacterial genera and species. Our work suggests that the interaction with different bacteria plays a key role in the survival strategies of and supports the need to incorporate biotic factors into the research conducted to identify mechanisms deployed by this organism for establishment in different environments.
与食物相关或环境细菌之间的相互作用不仅对微生物的生长至关重要，而且对许多关键的生物学过程也至关重要。在这方面，关于其他微生物对 的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 小时）评估了 在单一培养物或与 、 、 或 共培养物中的生长情况。在 10°C 下生长 3 天或在 37°C 下生长 9 小时后，测定了 9 个关键毒力基因（ 、 、 、 、 、 、 和 ）的转录水平以及侵袭效率和在 Caco-2 细胞中的细胞内生长情况。 的生长受到 和 的存在的负面影响，而细胞间接触对 的生长的影响取决于竞争微生物。共培养以特定于微生物的方式影响 的毒力特性，主要增强 和 对 Caco-2 细胞中病原体的侵袭。在存在四种测试细菌的情况下评估 毒力基因的 mRNA 水平表明，观察到的上调或下调与生长或毒力仅部分相关，并且主要表明 可能表现出特定于微生物的转录反应。 是严重食源性疾病李斯特菌病的病原体。在过去的 20 年中，已经获得了有关该微生物生理学和感染生物学的重要见解。然而，尽管 在其生命周期中以及从环境传播到食物再传播到宿主的过程中与各种微生物共存，但有关周围微生物对 生物学功能的影响的知识仍然有限。在这项研究中，我们表明 会针对共存的微生物调节特定的生物学活性（即生长和毒力潜力），并在面对不同的细菌属和种时改变与毒力相关的基因表达。我们的工作表明，与不同细菌的相互作用在 的生存策略中起着关键作用，并支持将生物因素纳入研究的必要性，以识别该生物体在不同环境中建立的机制。
