Laboratory of Molecular Microbiology, Global Health Institute, School of Life Sciences, Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland.
Laboratory of Molecular Microbiology, Global Health Institute, School of Life Sciences, Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland
J Bacteriol. 2021 Mar 23;203(8). doi: 10.1128/JB.00034-21.
is a severe threat to human health as a frequently multidrug-resistant hospital-acquired pathogen. Part of the danger from this bacterium comes from its genome plasticity and ability to evolve quickly by taking up and recombining external DNA into its own genome in a process called natural competence for transformation. This mode of horizontal gene transfer is one of the major ways that bacteria can acquire new antimicrobial resistances and toxic traits. Because these processes in are not well studied, we herein characterized new aspects of natural transformability in this species that include the species' competence window. We uncovered a strong correlation with a growth phase-dependent synthesis of a type IV pilus (TFP), which constitutes the central part of competence-induced DNA uptake machinery. We used bacterial genetics and microscopy to demonstrate that the TFP is essential for the natural transformability and surface motility of , whereas pilus-unrelated proteins of the DNA uptake complex do not affect the motility phenotype. Furthermore, TFP biogenesis and assembly is subject to input from two regulatory systems that are homologous to , namely, the PilSR two-component system and the Pil-Chp chemosensory system. We demonstrated that these systems affect not only the piliation status of cells but also their ability to take up DNA for transformation. Importantly, we report on discrepancies between TFP biogenesis and natural transformability within the same genus by comparing data for our work on to data reported for , the latter of which served for decades as a model for natural competence. Rapid bacterial evolution has alarming negative impacts on animal and human health which can occur when pathogens acquire antimicrobial resistance traits. As a major cause of antibiotic-resistant opportunistic infections, is a high-priority health threat which has motivated renewed interest in studying how this pathogen acquires new, dangerous traits. In this study, we deciphered a specific time window in which these bacteria can acquire new DNA and correlated that with its ability to produce the external appendages that contribute to the DNA acquisition process. These cell appendages function doubly for motility on surfaces and for DNA uptake. Collectively, we showed that is similar in its TFP production to , though it differs from the well-studied species .
是一种严重威胁人类健康的医院获得性多药耐药病原体。这种细菌的部分危险来自于其基因组的可塑性和快速进化的能力，通过将外部 DNA 吸收并重组到自身基因组中，从而产生自然转化的能力。这种水平基因转移的模式是细菌获得新的抗生素耐药性和毒性特征的主要途径之一。由于对 中的这些过程研究不足，我们在此描述了该物种自然转化能力的一些新方面，包括该物种的感受态窗口。我们发现了与一种依赖于生长阶段的 IV 型菌毛（TFP）合成之间的强烈相关性，这构成了感受态诱导 DNA 摄取机制的核心部分。我们利用细菌遗传学和显微镜技术证明，TFP 是 自然转化能力和表面运动性所必需的，而与 DNA 摄取复合物无关的菌毛相关蛋白不会影响运动表型。此外，TFP 的生物发生和组装受到两个与 同源的调控系统的输入，即 PilSR 双组分系统和 Pil-Chp 化学感受系统。我们证明，这些系统不仅影响细胞的菌毛状态，还影响它们摄取 DNA 进行转化的能力。重要的是，我们通过比较我们在 上的工作数据和几十年来一直作为自然感受态模型的 报告的数据，报告了同一属内 TFP 生物发生和自然转化能力之间的差异。当病原体获得抗生素耐药性特征时，快速的细菌进化会对动物和人类健康产生惊人的负面影响。 作为抗生素耐药性机会性感染的主要原因，是一个高度优先的健康威胁，这促使人们重新关注研究这种病原体如何获得新的、危险的特征。在这项研究中，我们破译了这些细菌可以获得新 DNA 的特定时间窗口，并将其与产生有助于 DNA 摄取过程的外部附属物的能力相关联。这些细胞附属物对表面运动和 DNA 摄取都有双重作用。总的来说，我们表明，尽管与研究充分的物种 不同，但 在 TFP 产生方面与其相似。
