Evaluation of New Enzyme-Linked Immunosorbent Assay Based on a Supernatant Containing Staphylococcus Aureus Alpha-Toxin Produced by Bacillus Subtilis

J Clin Microbiol. 1993 Nov;31(11):3036-9.


The gene encoding alpha-toxin from Staphylococcus aureus was cloned into a Bacillus subtilis expression vector (pEF 231/alpha-Tox). The protease-deficient B. subtilis strain DB 104 transformed with pEF 231/alpha-Tox expressed and secreted 5 mg of alpha-toxin per liter into the growth medium. The alpha-toxin-containing supernatant was diluted 200-fold and used as coating antigen in an enzyme-linked immunosorbent assay (ELISA) for serodiagnosis of septicemia and endocarditis caused by S. aureus. Paired sera from patients in acute and convalescent stages of S. aureus and non-S. aureus infections were used to evaluate this ELISA. To evaluate the effectiveness of the crude preparation, the results were compared with those of an ELISA based on a commercially available alpha-toxin. Similar rises in serum titers were obtained with either type of alpha-toxin preparation. This is the first time a crude supernatant without any further purification has been used as an ELISA coating antigen. We therefore conclude that B. subtilis is a suitable host organism for cheap and simple production of prokaryotic recombinant antigens to be used in serodiagnosis.

MeSH terms

  • Antibodies, Bacterial / analysis*
  • Bacillus subtilis / genetics*
  • Bacterial Toxins / biosynthesis
  • Bacterial Toxins / genetics
  • Bacterial Toxins / immunology*
  • Enzyme-Linked Immunosorbent Assay
  • Hemolysin Proteins / biosynthesis
  • Hemolysin Proteins / genetics
  • Hemolysin Proteins / immunology*
  • Humans
  • Recombinant Proteins / immunology*
  • Serologic Tests
  • Staphylococcal Infections / diagnosis*
  • Staphylococcus aureus / immunology*


  • Antibodies, Bacterial
  • Bacterial Toxins
  • Hemolysin Proteins
  • Recombinant Proteins
  • staphylococcal alpha-toxin