From cell-to-cell heterogeneity to collective behaviors in bacterial biofilms

项目摘要 细菌生物膜是由自生的聚合物基质粘在一起的细菌群落。 它们几乎存在于地球上的每一个环境中，是大多数医院传播疾病的原因。 感染.这些附着的群落对抗生素及其极端的耐药性非常高。 弹性不能仅仅归因于药物分子不能穿透生物膜 矩阵很明显，生物膜中的突发多细胞行为赋予了独特的 生存策略近年来，我们已经了解了基因调控的详细机制， 和单个细菌细胞的表型异质性，但我们既没有探索这些 细胞现象的背景下拥挤，多细胞生物膜，我们也不知道如何 多细胞行为源自这些单细胞特性。我的实验室下一个目标 五年的时间将用来了解单细胞的特性和当地环境的物理学 在生物膜中产生有益的涌现行为。有了这个MIRA奖，我的团队将 通过关注两种集体现象来探索这些问题：1）细胞间的电 通信和2）在生物膜期间运动和基质产生细胞的模式的出现 发展我们将使用空间基因表达测量来解决这些问题， 生物膜的单细胞水平延时成像，以及用于电成像的新型晶体管器件。 生物膜的扰动为了探索群体行为从单细胞特性中的出现， 我们将使用实验性生物膜模型物种枯草芽孢杆菌来干扰已知的细胞间 通讯机制和基因调控回路。我们的数据将提供定量信息， 多细胞现象的模型，这将给我们一个系统级的理解， 微生物的多细胞行为，以及提出新的假设和目标， 破坏了使生物膜逃避治疗的紧急行为。

PROJECT SUMMARY Bacterial biofilms are communities of bacteria stuck together by a self-produced polymer matrix. They exist in nearly every environment on earth and are the cause of most hospital-borne infections. These adherent communities are highly tolerant of antibiotics and their extreme resilience cannot merely be attributed to the inability of drug molecules to penetrate the biofilm matrix. It has become clear that emergent, multicellular behaviors in biofilms impart unique survival strategies. In recent years, we have learned detailed mechanisms of gene regulation and phenotypic heterogeneity of single bacterial cells, but we have neither explored these cellular phenomena in the context of crowded, multicellular biofilms, nor do we understand how multicellular behaviors emerge from these single-cell properties. The goal of my lab for the next five years will be to understand how single-cell properties and physics of the local environment give rise to beneficial emergent behaviors in biofilms. With this MIRA award, my group will explore these questions by focusing on two collective phenomena: 1) electrical cell-to-cell communication and 2) emergence of patterns of motile and matrix-producing cells during biofilm development. We will approach these problems using spatial gene expression measurements, single-cell-level time-lapse imaging of biofilms, and novel transistor devices for electrical perturbation of biofilms. To probe the emergence of group behaviors from single-cell properties, we will use the experimental biofilm model species Bacillus subtilis to perturb known cell-to-cell communication mechanisms and gene regulatory circuits. Our data will inform quantitative models of multicellular phenomena, which will give us a system-level understanding of multicellular behaviors in microbes, as well as suggesting new hypotheses and targets for disrupting the emergent behaviors that allow biofilms to elude treatment.