Quantification of Escherichia Coli Biofilm Gene Expression Among Interactions of Crohn’s-Associated Adherent Invasive Escherichia Coli and Enterococcus Faecalis

Crohn’s disease (CD) is a form of inîammatory bowel disease (IBD) characterized by chronic inîammation throughout the gastrointestinal (GI) tract. While the precise etiology of CD remains unknown, the abundance and translocation of pathobiont microbes have consistently been implicated in pathogenesis and diagnosis. Various types of pro-inîammatory bacteria contribute to this inîammation, colonizing diìerent regions of the GI tract and persisting through the formation of bioílms. A notable strain of Escherichia coli (E. coli) known as adherent invasive E. coli (AIEC) is a pathobiont that colonizes the mucosal tissues of CD patients and contributes to intestinal inîammation. AIEC is often found in bioílms within the mucosa, which enhances survival and proliferation by providing protective mechanisms against host immune responses. In addition to AIEC, Enterococcus faecalis (E. faecalis) is another bioílm-forming pathogen displaying a high colonization rate in CD and thrives within a polymicrobial bioílm alongside E. coli. While many researchers have concentrated on host-microbe interactions concerning IBD pathogenesis, progression, and inîammatory responses, relatively little is known about the potential microbe-microbe interactions that may also contribute to these processes. Characterizing these interactions is essential for understanding their implications for bacterial persistence, host immune responses, and progression of CD. This research aims to identify beneícial interactions between AIEC and E. faecalis, which may aid their persistence in inîamed GI regions, by examining changes in bioílm phenotype and gene expression related to E. coli bioílm production in co-cultures. Our previous índings indicate that AIEC exhibits a distinctive wrinkled colony morphology when co-cultured with E. faecalis, suggesting that this interaction may promote bioílm formation. To further analyze this dual-bioílm interaction, gene expression of key elements in E. coli bioílm was targeted in AIEC/non-AIEC isolates to quantify transcriptional changes when co-cultured with E. faecalis. A deeper understanding of these bioílms' structure and mechanisms is crucial, as they play a signiícant role in the gut microbial communities associated with IBD.