setCDQR regulon of the integrating and conjugative elements of the SXT/R391 family: a genetic and molecular study / Étude génétique et moléculaire du régulon setCDR des ICE SXT/R391

SXT/R391 家族整合和共轭元件的 setCDQR 调节：遗传和分子研究 / âtude génétique et moléculaire du régulon setCDR des ICE SXT/R391

• 批准号: 326810-2011
• 负责人: Burrus, Vincent
• 金额: $ 4.08万
• 依托单位: Université de Sherbrooke
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2014
• 资助国家: 加拿大
• 起止时间: 2014-01-01 至 2015-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=548898
• 关键词: setCDQR; regulon; integrating; conjugative; elements

Integrating conjugative elements (ICEs) are mobile gene clusters that are exchanged between bacteria during a direct cell-to-cell contact. ICEs allow microorganisms to exchange genes conferring an advantage in specific environments such as resistance to antibiotics and enhanced virulence. A family of ICE originally identified in Vibrio cholerae, the causative agent of the diarrheal disease cholera, is rapidly spreading among environmental and clinical strains of diverse human and animal pathogens dwelling in aquatic environments. As a consequence, this family of ICEs contributes to the rapid spread of multi-resistance to antibiotics within populations of pathogenic microorganisms worldwide. While the environmental stimuli that trigger the exchange of ICEs between bacteria are well known, the molecular mechanisms of this activation are not well understood. The goal of this research project is to investigate and understand in detail the cascade of events initiated by the stimulus (DNA-damaging agents such as UV light and some antibiotics) that leads to the exchange of ICEs between donor and recipient cells. We will study regulator proteins (activators and repressors) encoded by the ICEs that control the expression of ICE-borne genes involved in the formation of the mating bridge that connect the donor and recipient cell to allow ICE transfer. Furthermore, recent evidence indicate that some of these activators stimulate the expression of genes of the host bacterium together with ICE-borne genes. We will investigate the scale of this phenomenon in order to assess the impact of the acquisition of an ICE by a bacterial cell on the expression of its own genes and its virulence. This research project is part of a larger program aimed at understanding better the molecular aspects of the mechanisms of gene exchange between microorganisms, as well as the role of gene exchange on bacterial genome evolution and on the population dynamics of pathogens in aquatic environments.

集成共轭元素（ICE）是在直接细胞对细胞接触过程中细菌之间交换的移动基因簇。 ICE允许微生物交换在特定环境中赋予优势的基因，例如对抗生素和增强的毒力。最初在腹泻病霍乱的病因霍乱中鉴定出的一个冰家族迅速在水生环境中居住的多种人和动物病原体的环境和临床菌株之间迅速扩散。结果，这个冰的家族有助于全球致病微生物种群中多种耐药性迅速传播。尽管众所周知，触发冰之间的环境刺激是众所周知的，但这种激活的分子机制尚不清楚。该研究项目的目的是详细研究和理解刺激引发的事件的级联（DNA受损剂，例如紫外线和某些抗生素），从而导致供体和受体细胞之间的ICE交换。我们将研究由冰的编码的调节蛋白（激活剂和阻遏物），这些冰是控制着与供体和受体细胞相连的配合桥形成的冰培养基因表达的表达，以允许冰的传递。此外，最近的证据表明，这些激活剂中的一些刺激宿主细菌的基因与冰播基因的表达。我们将研究这种现象的规模，以评估细菌细胞对冰的采集对其自身基因表达及其毒力的影响。该研究项目是一个较大计划的一部分，旨在更好地理解微生物之间基因交换机制的分子方面，以及基因交换对细菌基因组进化的作用以及在水生环境中病原体的种群动态。