CAG Student Prize Paper – A3 ESCHERICHIA COLI PATHOBIONTS ISOLATED FROM ULCERATIVE COLITIS PATIENTS HARBOUR NUMEROUS PROTEINS THAT DEGRADE HUMAN COLONIC MUCUS

作者：A. Gilliland, A. Melville-Bowser, D. Tertigas, I. Ng, Y. Chen, M. Surette, B. Bressler, B. Vallance · 发表于：Journal of the Canadian Association of Gastroenterology · 年份：2026 · DOI：10.1093/jcag/gwaf042.003

Abstract Background The etiology of ulcerative colitis (UC) remains elusive, with current evidence suggesting weakened mucosal barriers allow noxious luminal stimuli to escape the colonic lumen and trigger inflammation. Escherichia coli pathobionts, particularly of phylogroup B2, have been associated with active UC, however their role in disease is unclear. We previously showed that UC-associated E. coli p19A can penetrate the mucus barrier of UC air-liquid interface (ALI) monolayers. We hypothesize that E. coli pathobionts carried by UC patients degrade their colonic mucosal barriers, thereby contributing to the onset, severity, and chronicity of UC. Aims Using healthy and UC patient biopsy-derived colonic organoids and an ALI monolayer model, we investigated the ability of p19A as well as other E. coli isolates from UC patients to degrade human colonic mucus. Methods ALI monolayers from non-IBD and UC patients were grown, with apical mucus collected, then incubated with secreted proteins from E. coli p19A. Degraded mucus was detected by protein gel and MUC2 western blot. To expand our understanding of UC-isolated E. coli mucus degradation, we analyzed the phylogeny and the mucinases present in the genomes of 92 E. coli strains isolated from UC patients as well as assessed a subset of isolates ability to degrade human mucus. Results We show that p19A degrades human ALI monolayer-derived mucus, with UC ALI-mucus more readily degraded. We identified the known mucinases Pic and...