Characterization of surface layer proteins from different Clostridium difficile clinical isolates

Microb Pathog. 2000 Jun;28(6):363-72. doi: 10.1006/mpat.2000.0356.


In a previous study we suggested that two surface proteins of a Clostridium difficile strain were involved in the formation of a regularly assembled surface layer (S-layer) external to the cell wall. In the present paper six C. difficile strains isolated from cases and healthy carriers were studied. By using freeze-etching and negative staining techniques two superimposed structurally different lattices were detected on the cell surface of the different C. difficile strains. In each strain, the outer S-layer lattice was arranged in a square symmetry and the inner S-layer lattice in hexagonal symmetry. The S-layer proteins from the different strains were isolated and characterized. Each strain showed two distinct S-layer glycoproteins ranging in molecular mass 36-56 kDa. Antigenic cross-reactivity among the S-layer proteins of higher molecular masses extracted from each strain was demonstrated whereas no antigenic relationship was observed among the different S-layer proteins of lower molecular masses. N-terminal sequence analysis showed the presence of common structural motifs conserved among the high S-layer proteins as well as among the low S-layer proteins. These data indicate that the presence of S-layer on C. difficile strains is common and that its glycoprotein subunits show a certain degree of heterogeneity.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Amino Acid Sequence
  • Bacterial Outer Membrane Proteins / analysis*
  • Bacterial Outer Membrane Proteins / chemistry
  • Bacterial Outer Membrane Proteins / ultrastructure
  • Blotting, Western
  • Cell Wall / chemistry
  • Cell Wall / drug effects
  • Cell Wall / ultrastructure
  • Child
  • Clostridium difficile / chemistry*
  • Clostridium difficile / genetics
  • Clostridium difficile / ultrastructure
  • Electrophoresis, Polyacrylamide Gel
  • Enterocolitis, Pseudomembranous / microbiology
  • Freeze Etching
  • Glycoproteins / analysis*
  • Humans
  • Immune Sera
  • Infant, Newborn
  • Microscopy, Electron
  • Molecular Sequence Data
  • Urea


  • Bacterial Outer Membrane Proteins
  • Glycoproteins
  • Immune Sera
  • Urea