ABSTRACT
The organism can be found throughout the gastrointestinal tract; however it appears to have an affinity for epithelial cells in the jejunum. ileum and proximal colon. Cholangiocytes are also susceptible to infection. and apoptosis of these epithelial cells likely contributes to biliary tract disease. The respiratory tract also appears to be a site of infection in irnmunocompromised individuals. Epithelial cell death. by both apoptotic and necrotic mechanisrus. has been noted in involved regions. There is evidence that infected epithelial cdIs can induce apoptosis in neighboring uninfected cells. Epithelial cell infection usually culminates in dysregulation of cell signaling pathways including upregulation of proinBarnmatory cascades as well as cyclooxygenase-2. prostaglandins and neuropeptide production. These perturbations result in epithelial barrier dysfunction. augmented intestinal permeability. dysregulation of electrolyte absorption and secretion and fluid malabsorption. Accordingly. symptomatic infection usually manifests as watery diarrhea.
