Surface Structures of C. difficile and Other Clostridia: Implications for Pathogenesis and Immunity
Jenny Emerson and Neil Fairweather
from: Clostridia: Molecular Biology in the Post-genomic Era (Edited by: Holger Brüggemann and Gerhard Gottschalk). Caister Academic Press, U.K. (2009)
The cell wall of Clostridium difficile has an architecture typical of other Gram-positive bacteria. A thick peptidoglycan layer lies external to the cell membrane with many associated cell wall proteins. In C. difficile two major cell wall proteins constitute the S-layer, a paracrystalline two-dimensional array surrounding the entire cell. The sequences of these S layer proteins (SLPs) are variable between strains, perhaps reflecting immunological pressures on the cell. The genome sequence reveals a family of proteins with homology to the high molecular weight SLP; each of these proteins have a second unique domain but their functions remain largely uncharacterised. This family of cell wall proteins is also found in some other species, for example C. botulinum and C. tetani, but not in others such as C. perfringens. Some cell wall proteins of C. difficile, including the SLPs, have properties that imply an involvement in pathogenesis, particularly in binding to host cell tissues. The cell wall proteins of C. difficile may also act as immunogens to induce a partially protective immune response to infection, and may be considered as components of future vaccines against C. difficile associated disease read more ...