Department of Biological Sciences, Ohio University, Athens, Ohio, USA.
Molecular and Cellular Biology Program, Ohio University, Athens, Ohio, USA.
mSphere. 2021 Mar 17;6(2):e01303-20. doi: 10.1128/mSphere.01303-20.
is an opportunistic pathogen that colonizes the anterior nares of 30 to 50% of the population. Colonization is most often asymptomatic; however, self-inoculation can give rise to potentially fatal infections of the deeper tissues and blood. Like all bacteria, can sense and respond to environmental cues and modify gene expression to adapt to specific environmental conditions. The transition of from the nares to the deeper tissues and blood is accompanied by changes in environmental conditions, such as nutrient availability, pH, and temperature. In this study, we perform transcriptomics and proteomics on cultures growing at three physiologically relevant temperatures, 34°C (nares), 37°C (body), and 40°C (pyrexia), to determine if small scale, biologically meaningful alterations in temperature impact gene expression. Results show that small but definite temperature changes elicit a large-scale restructuring of the transcriptome and proteome in a manner that, most often, inversely correlates with increasing temperature. We also provide evidence that a large majority of these changes are modulated at the posttranscriptional level, possibly by sRNA regulatory elements. Phenotypic analyses were also performed to demonstrate that these changes have physiological relevance. Finally, we investigate the impact of temperature-dependent alterations in gene expression on pathogenesis and demonstrate decreased intracellular invasion of grown at 34°C. Collectively, our results demonstrate that small but biologically meaningful alterations in temperature influence gene expression, a process that is likely a major contributor to the transition from a commensal to pathogen. Enteric bacterial pathogens, like , are known to experience large temperature differences as they are transmitted through the fecal oral route. This change in temperature has been demonstrated to influence bacterial gene expression and facilitate infection. is a human-associated pathogen that can live as a commensal on the skin and nares or cause invasive infections of the deeper tissues and blood. Factors influencing nasal colonization are not fully understood; however, individuals colonized with are at increased risk of invasive infections through self-inoculation. The transition of from the nose (colonization) to the body (infection) is accompanied by a modest but definite temperature increase, from 34°C to 37°C. In this study, we investigate whether these host-associated small temperature changes can influence gene expression. Results show widespread changes in the bacterial transcriptome and proteome at three physiologically relevant temperatures (34°C, 37°C, and 40°C).
是一种机会性病原体，定植于人群中 30%至 50%的人的前鼻孔。定植通常无症状；然而，自身接种可引起深部组织和血液的潜在致命感染。与所有细菌一样，能够感知和响应环境线索，并改变基因表达以适应特定的环境条件。从鼻腔到深部组织和血液的转变伴随着环境条件的变化，如营养物质的可用性、pH 值和温度。在这项研究中，我们对在三个生理相关温度（34°C（鼻腔）、37°C（体温）和 40°C（发热））下生长的培养物进行转录组学和蛋白质组学分析，以确定微小的、有生物学意义的温度变化是否会影响 基因表达。结果表明，微小但明确的温度变化会导致 转录组和蛋白质组的大规模重构，这种重构通常与温度升高呈反比。我们还提供了证据表明，这些变化中的绝大多数是在转录后水平上调节的，可能是通过 sRNA 调节元件。表型分析也表明这些变化具有生理相关性。最后，我们研究了温度依赖性基因表达变化对发病机制的影响，并证明在 34°C 下生长的细菌细胞内入侵减少。总之，我们的研究结果表明，微小但有生物学意义的温度变化会影响 基因表达，这一过程可能是从共生菌到病原体转变的主要因素。像 这样的肠道细菌病原体在通过粪-口途径传播时会经历很大的温度差异。这种温度变化已被证明会影响细菌基因表达并促进感染。 是一种与人类相关的病原体，它可以作为皮肤和鼻腔的共生菌存在，也可以引起深部组织和血液的侵袭性感染。影响 鼻腔定植的因素尚不完全清楚；然而，定植了 的个体通过自身接种感染的风险增加。从鼻腔（定植）到身体（感染）的转变伴随着适度但明确的温度升高，从 34°C 升高到 37°C。在这项研究中，我们研究了这些宿主相关的小温度变化是否会影响 基因表达。结果表明，在三个生理相关温度（34°C、37°C 和 40°C）下，细菌的转录组和蛋白质组发生了广泛变化。
