Microbiology and Immunology 4100A Lecture Notes - Lecture 14: Spi1, Intestinal Epithelium, Zipper
22 Dec 2019
School
Department
Professor
Document Summary
Family of gram negative enteropathogenic bacteria that colonize a wide range of animal hosts. Agent of gastroenteritis and typhoid fever (cause by s. typhi) Virulence strategies depend on invasion of non-phagocytize epithelial cells > may be followed by systemic spread (to liver and spleen) All salmonella have the capacity to invade epithelial cells, causing enteric infections. M cells are specialized intestinal epithelial cells that are not ciliated and function to sample antigens present on the intestinal epithelium. Will then present the antigen to the underlying macrophage and dcs. Many bacteria use m cells to enter into the tissue. Are not ciliated and not have have as much mucous covering them (cid:12254) Salmonella pathogenicity islands spi-1 and spi-2 are necessary for enteric and systemic infections. Invasion and replication is dependent on their possession of pathogenicity islands. Pathogenicity islands are part of the accessory genome. Only present in some strains and not in others. Are clusters of genes that encode specialized functions.
