PRODUCTION, CHARACTERIZATION AND IMMUNODIAGNOSTIC APPLICATION OF A MONOCLONAL-ANTIBODY TO SHIGA TOXIN

A mouse monoclonal antibody (MAb ICT7) that is specific for Shiga toxi n was produced. The MAb neutralises the cytotoxic effects of both puri fied Shiga toxin and culture extracts of Shigella dysenteriae type 1 i n HeLa cells. Using MAb ICT7 and polyclonal rabbit antiserum, a sandwi ch ELISA was developed, This test detects Shiga toxin in both S. dysen teriae type 1 bacterial extracts and in stools of patients with S, dys enteriae type 1 infection. The ELISA also detects toxin in enterohaemo rrhagic Escherichia coli (EHEC) strains positive for Shiga-like toxin I, The test could detect a minimum of 100 pg of purified Shiga toxin, Furthermore, the ELISA did not detect toxin in non-S. dysenteriae type 1 Shigella species or Shiga-like toxin II produced by EHEC strains.