Comparison of Clostridium sordellii toxins HT and LT with toxins A and B of C. difficile

J Med Microbiol. 1992 Jan;36(1):30-6. doi: 10.1099/00222615-36-1-30.


Clostridium sordellii produces two toxins, designated HT (haemorrhagic toxin) and LT (lethal toxin), that are similar to toxins A and B of C. difficile. The physicochemical properties of toxins HT and A were remarkably similar. The specific biological activities of toxin HT were almost the same as those of toxin A, and their NH2-terminal sequences shared close homology. The properties of toxins LT and B were similar, as were their NH2-terminal sequences, but toxin B was much more cytotoxic than toxin LT. Immunodiffusion analysis with specific antibodies showed that although toxins B and LT shared major antigenic determinants, each had unique epitopes. The results suggest that toxins B and LT have diverged more than toxins A and HT. Immunoblotting with antibodies to the toxins of C. difficile showed that toxins HT and LT had common antigenic determinants.

Publication types

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

MeSH terms

  • Amino Acid Sequence
  • Amino Acids / analysis
  • Bacterial Proteins*
  • Bacterial Toxins / chemistry*
  • Bacterial Toxins / immunology
  • Bacterial Toxins / isolation & purification
  • Clostridium / chemistry*
  • Clostridium difficile / chemistry*
  • Enterotoxins / chemistry*
  • Enterotoxins / immunology
  • Enzyme-Linked Immunosorbent Assay
  • Epitopes
  • Hemagglutination Tests
  • Immunoelectrophoresis
  • Molecular Sequence Data
  • Peptide Mapping


  • Amino Acids
  • Bacterial Proteins
  • Bacterial Toxins
  • Enterotoxins
  • Epitopes
  • hemorrhagic toxin HT, Clostridium sordellii
  • lethal toxin LT, Clostridium sordellii
  • tcdA protein, Clostridium difficile
  • toxB protein, Clostridium difficile