title: Variation in the surface layer proteins of Clostridium difficile.
abstract: Surface layers (S-layers) form regular crystalline structures on the outermost surface of many bacteria. Clostridium difficile possesses such an S-layer consisting of two protein subunits. Treatment of whole cells of C. difficile with 5 M guanidine hydrochloride revealed two major proteins of different molecular masses characteristic of the S-layer on SDS-PAGE. In this study 25 isolates were investigated. A high degree of variability in the molecular mass of the two S-layer proteins was evident. Molecular masses ranged from 48 to 56 kDa for the heavier protein and from 37 to 45 kDa for the lighter protein. A further protein component of 70 kDa was detectable in all isolates. No cross-reaction was seen between the two major proteins from isolates that produced different S-layer patterns, and most S-layer proteins from isolates with the same or similar banding patterns did not cross-react. The S-layer proteins, when detected by a combination of Coomassie blue staining and immunoblotting, are a useful marker for phenotyping.
authors.affiliation: Department of Medical Microbiology, University of Edinburgh Medical School, Teviot Place, Edinburgh, EH8 9AG, UK.
authors.forename: J
authors.initials: J
authors.lastname: McCoubrey
authors.forename: I R
authors.initials: IR
authors.lastname: Poxton
mesh_terms: D000818:Animals; D001425:Bacterial Outer Membrane Proteins / Q000032:analysis / Q000737:chemistry* / Q000276:immunology*; D001426:Bacterial Proteins / Q000032:analysis / Q000737:chemistry* / Q000276:immunology*; D015373:Bacterial Typing Techniques; D016360:Clostridioides difficile / Q000737:chemistry* / Q000145:classification / Q000235:genetics / Q000276:immunology*; D004591:Electrophoresis, Polyacrylamide Gel; D019791:Guanidine; D007106:Immune Sera / Q000276:immunology; D015151:Immunoblotting; D008970:Molecular Weight; D010446:Peptide Fragments / Q000737:chemistry; D011817:Rabbits
chemical_list: D001425:Bacterial Outer Membrane Proteins; D001426:Bacterial Proteins; D007106:Immune Sera; D010446:Peptide Fragments; C070683:surface layer protein A, Bacteria; D019791:Guanidine