Pathogenesis of Vascular Infections Unit, INSERM, Institut Pasteur, 75015 Paris, France.
Service de Physique de l'Etat Condensé, CEA, CNRS, Université Paris-Saclay, 91191 Gif-sur-Yvette, France.
Cell. 2018 Jun 28;174(1):143-155.e16. doi: 10.1016/j.cell.2018.04.010. Epub 2018 May 17.
Neisseria meningitidis, a bacterium responsible for meningitis and septicemia, proliferates and eventually fills the lumen of blood capillaries with multicellular aggregates. The impact of this aggregation process and its specific properties are unknown. We first show that aggregative properties are necessary for efficient infection and study their underlying physical mechanisms. Micropipette aspiration and single-cell tracking unravel unique features of an atypical fluidized phase, with single-cell diffusion exceeding that of isolated cells. A quantitative description of the bacterial pair interactions combined with active matter physics-based modeling show that this behavior relies on type IV pili active dynamics that mediate alternating phases of bacteria fast mutual approach, contact, and release. These peculiar fluid properties proved necessary to adjust to the geometry of capillaries upon bacterial proliferation. Intermittent attractive forces thus generate a fluidized phase that allows for efficient colonization of the blood capillary network during infection.
脑膜炎奈瑟菌是一种导致脑膜炎和败血症的细菌，它会增殖并最终在毛细血管的管腔中形成多细胞聚集物。目前尚不清楚这种聚集过程及其特定性质的影响。我们首先表明，聚集特性是有效感染所必需的，并研究了它们的潜在物理机制。微吸管抽吸和单细胞跟踪揭示了非典型流变体的独特特征，单细胞扩散超过了孤立细胞的扩散。细菌对相互作用的定量描述结合基于活性物质物理的建模表明，这种行为依赖于 IV 型菌毛的活跃动力学，该动力学介导了细菌快速相互接近、接触和释放的交替阶段。这些特殊的流体特性对于细菌增殖时适应毛细血管的几何形状是必要的。因此，间歇的吸引力产生了一种流变体，使得在感染过程中能够有效地定殖于血毛细血管网络。
