Spatial periodicity of Escherichia coli K-12 biofilm microstructure initiates during a reversible, polar attachment phase of development and requires the polysaccharide adhesin PGA
Spatial periodicity of Escherichia coli K-12 biofilm microstructure initiates during a reversible, polar attachment phase of development and requires the polysaccharide adhesin PGA
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DOI：
10.1128/jb.187.24.8237-8246.2005
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发表时间：
2005-12-01
影响因子：
3.2
通讯作者：
Romeo, T
中科院分区：
文献类型：
--
作者：
Agladze, K;Wang, X;Romeo, T
使用快速傅立叶变换 (FFT) 分析，我们之前观察到大肠杆菌生物膜内的细胞以非随机或周期性空间模式组织（K. Agladze 等人，J. Bacteriol. 185:5632-5638, 2003）。在这里，我们开发了一种重力位移测定法来检查细胞粘附，并用它来定量监测早期生物膜发育过程中两种不同形式的细胞附着（临时和永久）的形成。临时附着的细胞主要通过细胞极进行表面连接；永久附着是通过侧细胞表面进行的。虽然临时依恋先于永久依恋，但这两种形式可以在群体中共存。将附着的细胞暴露在重力下，释放出未附着的群体，该群体能够快速重新组装新的单层，该单层由临时附着的细胞组成，并具有周期性。 csrA突变体比其野生型亲本更强有力地形成生物膜，表现出永久附着细胞比例增加以及亲本菌株中不明显的附着形式，即永久极性附着。然而，它形成了周期性的依恋模式。相比之下，脂多糖合成（waaG）改变的生物膜突变体表现出细胞间相互作用增加，绕过极性附着步骤，并产生非周期性细胞分布特征的FFT光谱。缺乏多糖粘附素β-1,6-N-乙酰基-D-葡萄糖胺（Delta pgaC）的突变体也表现出非周期性细胞分布，但没有明显的细胞间相互作用，并且在形成永久附着方面存在缺陷。因此，生物膜微结构的空间周期性是由基因决定的，并且在临时细胞表面附着物的形成过程中是明显的。
Using fast Fourier transform (FFT) analysis, we previously observed that cells within Escherichia coli biofilm are organized in nonrandom or periodic spatial patterns (K. Agladze et al., J. Bacteriol. 185:5632-5638, 2003). Here, we developed a gravity displacement assay for examining cell adherence and used it to quantitatively monitor the formation of two distinct forms of cell attachment, temporary and permanent, during early biofilm development. Temporarily attached cells were mainly surface associated by a cell pole; permanent attachments were via the lateral cell surface. While temporary attachment precedes permanent attachment, both forms can coexist in a population. Exposure of attached cells to gravity liberated an unattached population capable of rapidly reassembling a new monolayer, composed of temporarily attached cells, and possessing periodicity. A csrA mutant, which forms biofilm more vigorously than its wild-type parent, exhibited an increased proportion of permanently attached cells and a form of attachment that was not apparent in the parent strain, permanent polar attachment. Nevertheless, it formed periodic attachment patterns. In contrast, biofilm mutants with altered lipopolysaccharide synthesis (waaG) exhibited increased cell-cell interactions, bypassed the polar attachment step, and produced FFT spectra characteristic of aperiodic cell distribution. Mutants lacking the polysaccharide adhesin beta-1,6-N-acetyl-D-glucosamine (Delta pgaC) also exhibited aperiodic cell distribution, but without apparent cell-cell interactions, and were defective in forming permanent attachments. Thus, spatial periodicity of biofilm microstructure is genetically determined and evident during the formation of temporary cell surface attachments.