Surgical stress shifts the intestinal Eschericia coli population to that of a more adherent phenotype: Role in barrier regulation

Background. We have shown that the combination of surgical stress and starv ation in mice is associated with a defect in epithelial permeability and in creased numbers of mucosa-associated Escherichia coli in the cecum. The aim of this study was to determine the specific role of mucosa-associated E co li on epithelial barrier dysfunction in this model. Methods, Cecal E coli were harvested from mice 48 hours after a sham operat ion (control mice) or after a 30% surgical hepatectomy with only water prov ided ad libitum (short-term starvation) after the surgical procedure. Strai ns were tested for their ability to adhere to and alter the transepithelial electrical resistance (TEER) of cultured young adult mouse colon epithelia l cells. TEER changes were further characterized by mannitol fluxes to conf irm a defect in paracellular permeability. Results. Strains of cecal E coli harvested from hepatectomy-starved mice ad hered to and altered the permeability of young adult mouse colon cells, whe reas E. coli from the cecum of control mice were less adherent and had no e ffect on epithelial permeability. The effect of the strains harvested from mice after hepatectomy on the TEER of young adult mouse colon cells was inh ibited by mannose and reversed by ciprofloxacin. Conclusion. The combination of surgical stress and short-term starvation is associated with a greater abundance of adherent and barrier-altering strai ns of E. coli in the mouse cecum.