Rodrigues Sophie, Paillard Christine, Van Dillen Sabine, Tahrioui Ali, Berjeaud Jean-Marc, Dufour Alain, Bazire Alexis
Laboratoire de Biotechnologie et Chimie Marines (LBCM), EA 3884, LBCM, IUEM Université de Bretagne-Sud, 56100 Lorient, France.
UMR6539, Laboratoire des Sciences de l'Environnement Marin (LEMAR), Centre National de la Recherche Scientifique, Institut Universitaire Européen de la Mer, Université de Brest, UBO, IRD, Ifremer, 29280 Plouzané, France.
Pathogens. 2018 Nov 26;7(4):92. doi: 10.3390/pathogens7040092.
Marine pathogenic bacteria are able to form biofilms on many surfaces, such as mollusc shells, and they can wait for the appropriate opportunity to induce their virulence. can develop such biofilms on the inner surface of shells of the clam, leading to the formation of a brown conchiolin deposit in the form of a ring, hence the name of the disease: Brown Ring Disease. The virulence of is presumed to be related to its capacity to form biofilms, but the link has never been clearly established at the physiological or genetic level. In the present study, we used RNA-seq analysis to identify biofilm- and virulence-related genes displaying altered expression in biofilms compared to the planktonic condition. A flow cell system was employed to grow biofilms to obtain both structural and transcriptomic views of the biofilms. We found that 3615 genes were differentially expressed, confirming that biofilm and planktonic lifestyles are very different. As expected, the differentially expressed genes included those involved in biofilm formation, such as motility- and polysaccharide synthesis-related genes. The data show that quorum sensing is probably mediated by the AI-2/LuxO system in biofilms. The expression of genes encoding the Type VI Secretion System and associated exported proteins are strongly induced, suggesting that activates this virulence factor when living in biofilm.
海洋致病细菌能够在许多表面形成生物膜，比如软体动物的外壳，它们可以等待合适的时机来诱导其毒力。[某种细菌]能够在蛤的贝壳内表面形成这样的生物膜，导致形成呈环状的褐色贝壳硬蛋白沉积物，因此这种疾病被命名为：褐环病。[某种细菌]的毒力被推测与其形成生物膜的能力有关，但在生理或基因水平上，这种联系从未得到明确证实。在本研究中，我们使用RNA测序分析来鉴定与生物膜和毒力相关的基因，这些基因在生物膜中的表达与浮游状态相比发生了改变。采用流动细胞系统来培养生物膜，以获得生物膜的结构和转录组视图。我们发现3615个基因存在差异表达，证实了生物膜和浮游生活方式有很大不同。正如预期的那样，差异表达的基因包括那些参与生物膜形成的基因，如与运动性和多糖合成相关的基因。数据表明，群体感应可能由[某种细菌]生物膜中的AI-2/LuxO系统介导。编码VI型分泌系统及相关输出蛋白的基因表达被强烈诱导，这表明[某种细菌]在生物膜中生活时会激活这种毒力因子。
