Homologs of the LapD-LapG c-di-GMP Effector System Control Biofilm Formation by Bordetella bronchiseptica
Homologs of the LapD-LapG c-di-GMP Effector System Control Biofilm Formation by Bordetella bronchiseptica
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DOI：
10.1371/journal.pone.0158752
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发表时间：
2016-07-05
期刊：
影响因子：
3.7
通讯作者：
Sisti, Federico
中科院分区：
文献类型：
--
作者：
Ambrosis, Nicolas;Boyd, Chelsea D.;Sisti, Federico
生物膜的形成对于许多病原体的感染是重要的。支气管败血波氏杆菌引起哺乳动物的呼吸道感染，并在感染小鼠的鼻上皮中形成生物膜结构。我们以前证明，环二GMP参与生物膜形成在B。支气管炎在本工作中，基于它们在荧光假单胞菌中的功能，我们在B中鉴定了三个基因。可能参与c-di-GMP依赖性生物膜形成的支气管败血症基因组：brtA、lapD和lapG。遗传分析证实了BrtA，LapD和LapG在生物膜形成中的作用，使用微量滴定板测定，以及扫描电子和荧光显微镜分析缺乏这些蛋白质的突变体的表型。体外和体内研究表明，B.支气管败血症病毒裂解BrtA的N-末端结构域，以及荧光假单胞菌的LapA蛋白，表明这些物种之间的功能保守性。此外，虽然BrtA和LapG似乎对小鼠感染模型中的定殖具有很少或没有影响，但a B.与野生型相比，缺乏LapG蛋白酶的支气管败血症菌株具有显著更高的诱导严重疾病结果的比率。这些发现支持c-di-GMP通过BrtA/LapD/LapG调节生物膜形成以及影响B的发病机制的作用。支气管
Biofilm formation is important for infection by many pathogens. Bordetella bronchiseptica causes respiratory tract infections in mammals and forms biofilm structures in nasal epithelium of infected mice. We previously demonstrated that cyclic di-GMP is involved in biofilm formation in B. bronchiseptica. In the present work, based on their previously reported function in Pseudomonas fluorescens, we identified three genes in the B. bronchiseptica genome likely involved in c-di-GMP-dependent biofilm formation: brtA, lapD and lapG. Genetic analysis confirmed a role for BrtA, LapD and LapG in biofilm formation using microtiter plate assays, as well as scanning electron and fluorescent microscopy to analyze the phenotypes of mutants lacking these proteins. In vitro and in vivo studies showed that the protease LapG of B. bronchiseptica cleaves the N-terminal domain of BrtA, as well as the LapA protein of P. fluorescens, indicating functional conservation between these species. Furthermore, while BrtA and LapG appear to have little or no impact on colonization in a mouse model of infection, a B. bronchiseptica strain lacking the LapG protease has a significantly higher rate of inducing a severe disease outcome compared to the wild type. These findings support a role for c-di-GMP acting through BrtA/LapD/LapG to modulate biofilm formation, as well as impact pathogenesis, by B. bronchiseptica