Role of lipopolysaccharide of actinobacillus pleuropneumoniae in biofilm formation and pathogenesis

胸膜肺炎放线杆菌脂多糖在生物膜形成和发病机制中的作用

• 批准号: 3428-2011
• 负责人: Jacques, Mario
• 金额: $ 4.08万
• 依托单位: Université de Montréal
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2013
• 资助国家: 加拿大
• 起止时间: 2013-01-01 至 2014-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=520578
• 关键词: Role; lipopolysaccharide; actinobacillus; pleuropneumoniae; biofilm

The long-term objective of this research program is to gain a better understanding of the virulence factors involved in the Gram-negative bacterial pathogens colonization of the host's respiratory tract. Actinobacillus pleuropneumoniae (App), the etiological agent of porcine pleuropneumonia, is our model. We have generated a collection of lipopolysaccharide (LPS) mutants of App using transposon mutagenesis. We have shown that App LPS is involved in colonization of porcine respiratory tract and that deletion of specific residues in the LPS outer core results in the attenuation of the virulence of App. We hypothesize that LPS are involved in biofilm formation in App and that biofilm formation is a complex and finely regulated process which plays an important role in pathogenesis. The short-term objectives of this research program are: (1) to characterize the relation between LPS and biofilm formation. We will first characterize the collection of App LPS mutants we have generated and determine their ability to form biofilms. We will use a standard static biofilm assay in microtiter plates as well as a drip-flow cell which is more representative of the air-liquid interface found in the lungs. We will use phage display technology to select peptides with a strong affinity for purified LPS molecules. We will then quantify the affinity of these peptides using surface plasmon resonance and determine whether these peptides can interfere with biofilm formation or with other biological activities of LPS. (2) to use genomic (transposon mutagenesis) and transcriptomic (DNA microarray) approaches to identify additional genes involved in App biofilm formation. A better understanding of surface polysaccharides of App and of the genes expressed during biofilm formation will lead to the development of effective infection-control strategies such as novel molecules that can block the activity of important virulence factors or inhibit biofilm formation of App and, potentially, other pathogens of farm animals.

本研究计划的长期目标是更好地了解革兰氏阴性细菌病原体在宿主呼吸道定植的毒力因子。猪胸膜肺炎的病原菌是胸膜肺炎放线杆菌（Actinobacillus pleuropneumoniae，App）。我们已经产生了一个收集的脂多糖（LPS）突变体的应用转座子诱变。我们已经表明，应用程序LPS参与猪呼吸道的定植，并在LPS外核的特定残基的删除导致应用程序的毒力衰减。我们假设，LPS参与生物膜形成的应用程序和生物膜的形成是一个复杂的和精细的调节过程中起着重要作用的发病机制。本研究的近期目标是：（1）表征LPS与生物膜形成的关系。我们将首先表征我们已经产生的App LPS突变体的集合，并确定它们形成生物膜的能力。我们将使用微量滴定板中的标准静态生物膜测定以及更能代表肺中发现的气液界面的滴流式细胞仪。我们将使用噬菌体展示技术来选择对纯化的LPS分子具有强亲和力的肽。然后，我们将使用表面等离子体共振定量这些肽的亲和力，并确定这些肽是否可以干扰生物膜形成或LPS的其他生物活性。(2)使用基因组学（转座子诱变）和转录组学（DNA微阵列）方法来鉴定涉及App生物膜形成的其他基因。更好地了解应用程序的表面多糖和生物膜形成过程中表达的基因，将导致开发有效的感染控制策略，如新的分子，可以阻止重要的毒力因子的活性或抑制生物膜形成的应用程序，并可能，其他病原体的农场动物。