Metabolic adaption to extracellular pyruvate triggers biofilm formation in Clostridioides difficile. Metabolic adaption to extracellular pyruvate triggers biofilm formation in Clostridioides difficile

We applied time-course transcriptomics and genetics to identify sigma factors, metabolic processes and adhesins that drive biofilm formation. These analyses revealed that extracellular pyruvate induces biofilm formation in the presence of DOC. In the absence of DOC, pyruvate supplementation was sufficient to induce biofilm formation in a process that was dependent on pyruvate transport by the membrane protein CstA. Overall design: Total RNA was extracted from 3 independent biological replicates of 630 C. difficile strains at 3 conditions with 120µM, 240µM and without Deoxycholate at 9h, 14h, 24h and 48h (36 samples).

本研究采用时间进程转录组学（time-course transcriptomics）与遗传学分析手段，筛选驱动生物膜形成（biofilm formation）的σ因子（sigma factor）、代谢过程及黏附素（adhesin）。上述分析显示，在脱氧胆酸盐（Deoxycholate, DOC）存在的条件下，胞外丙酮酸可诱导生物膜形成；而在缺失脱氧胆酸盐的环境中，仅添加丙酮酸即可诱导生物膜形成，该过程依赖于膜蛋白CstA介导的丙酮酸转运。总实验设计：从艰难梭菌（C. difficile）630菌株的3组独立生物学重复中提取总RNA（total RNA），样本涵盖3种脱氧胆酸盐处理条件（120μM、240μM以及无脱氧胆酸盐），采样时间点为9h、14h、24h及48h，共计36个样本。