A microbiota-generated bile salt induces biofilm formation in Clostridium difficile Article - 2019

Thomas Dubois, Yannick D. N. Tremblay, Audrey Hamiot, Isabelle Martin-Verstraete, Julien Deschamps, Marc Monot, Romain Briandet, Bruno Dupuy

Thomas Dubois, Yannick D. N. Tremblay, Audrey Hamiot, Isabelle Martin-Verstraete, Julien Deschamps, Marc Monot, Romain Briandet, Bruno Dupuy, « A microbiota-generated bile salt induces biofilm formation in Clostridium difficile  », npj Biofilms and Microbiomes, 2019, np. ISSN 2055-5008

Abstract

Clostridium difficile is a major cause of nosocomial infections. Bacterial persistence in the gut is responsible for infection relapse ; sporulation and other unidentified mechanisms contribute to this process. Intestinal bile salts cholate and deoxycholate stimulate spore germination, while deoxycholate kills vegetative cells. Here, we report that sub-lethal concentrations of deoxycholate stimulate biofilm formation, which protects C. difficile from antimicrobial compounds. The biofilm matrix is composed of extracellular DNA and proteinaceous factors that promote biofilm stability. Transcriptomic analysis indicates that deoxycholate induces metabolic pathways and cell envelope reorganization, and represses toxin and spore production. In support of the transcriptomic analysis, we show that global metabolic regulators and an uncharacterized lipoprotein contribute to deoxycholate-induced biofilm formation. Finally, Clostridium scindens enhances biofilm formation of C. difficile by converting cholate into deoxycholate. Together, our results suggest that deoxycholate is an intestinal signal that induces C. difficile persistence and may increase the risk of relapse.

Voir la notice complète sur HAL

Actualités