Development of a Blocking Enzyme-Linked Immunosorbent Assay for Detection of Serum Antibodies to O157 Antigen of Escherichia Coli

Clin Diagn Lab Immunol. 1998 Mar;5(2):242-6.


The O157 antigen of Escherichia coli shares structural elements with lipopolysaccharide (LPS) antigens of other bacterial species, notably Brucella abortus and Yersinia enterocolitica 09, a fact that confounds the interpretation of assays for anti-O157 antibodies. To address this problem, a blocking enzyme-linked immunosorbent assay (bELISA) was designed with E. coli O157:H7 LPS as the antigen and a monoclonal antibody specific for E. coli O157, designated 13B3, as the competing antibody. The bELISA had equivalent sensitivity to, and significantly higher specificity than, the indirect ELISA (iELISA), detecting anti-O157 antibodies in sera from cattle experimentally inoculated with O157:H7. Only 13% of sera from naive heifers vaccinated for or experimentally infected with B. abortus had increased anti-O157 bELISA titers, while 61% of anti-O157 iELISA titers were increased. The bELISA is a sensitive and specific method for the detection of serum antibodies resulting from exposure to E. coli O157.

MeSH terms

  • Animals
  • Antibodies, Bacterial / blood*
  • Antibodies, Bacterial / immunology
  • Antigens, Bacterial / blood*
  • Antigens, Bacterial / immunology
  • Cattle
  • Enzyme-Linked Immunosorbent Assay / methods*
  • Escherichia coli Infections / blood
  • Escherichia coli Infections / immunology*
  • Escherichia coli O157 / immunology*
  • Sensitivity and Specificity


  • Antibodies, Bacterial
  • Antigens, Bacterial