Characterizing the Phenotypic Changes in E. coli Linked to IBD-related Fibrosis


Dana Battle, Junior, Biology and Chemistry, College of STEM

Faculty Mentor(s):

Rachel Bleich, University Of North Carolina at Chapel Hill




Inflammatory Bowel Disease (IBD) is characterized by chronic inflammation in the digestive tract with about 30% of patients developing fibrosis. IBD patients have an increased amount of E. coli in their digestive tract, with many of these E. coli producing Yersiniabactin (Ybt). Ybt is a siderophore that binds metal, providing nutrients to the bacteria. Changes to the ybt pathway are linked to fibrosis incidence in mice. My project focused on studying how ybt pathway mutations affected the behavior of the bacteria in vitro. My hypothesis is that mutations to the ybt pathway will cause phenotypic changes in the bacteria linked to metal availability. Growth curves were used to show the rate in which zinc (Zn) affected the growth of ybt-mutant E. coli compared to mutants without added metals and wild-type control. Other behaviors important for persistence in the gut, including motility and biofilm formation, were assayed with the ybt-mutants with added zinc. There were varied phenotypic changes depending on the assay, but results displayed that adding Zn did not impact bacterial growth or biofilm formation, but increased bacterial motility. Previous research reveals higher fibrosis incidence in mice colonized with ΔfyuA E. coli, however this  ybt-transporter mutant showed no phenotypic changes compared to other strains in our in vitro study. Next steps include changing the amount of Zn or changing the metal to Fe or Cu.


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