title: Development of a blocking enzyme-linked immunosorbent assay for detection of serum antibodies to O157 antigen of Escherichia coli.
abstract: 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.
authors.affiliation: U.S. Meat Animal Research Center, USDA Agricultural Research Service, Clay Center, Nebraska 68933, USA. laegreid@aux.marc.usda.gov
authors.forename: W
authors.initials: W
authors.lastname: Laegreid
authors.forename: M
authors.initials: M
authors.lastname: Hoffman
authors.forename: J
authors.initials: J
authors.lastname: Keen
authors.forename: R
authors.initials: R
authors.lastname: Elder
authors.forename: J
authors.initials: J
authors.lastname: Kwang
mesh_terms: D000818:Animals; D000907:Antibodies, Bacterial / Q000097:blood* / Q000276:immunology; D000942:Antigens, Bacterial / Q000097:blood* / Q000276:immunology; D002417:Cattle; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods*; D004927:Escherichia coli Infections / Q000097:blood / Q000276:immunology*; D019453:Escherichia coli O157 / Q000276:immunology*; D012680:Sensitivity and Specificity
chemical_list: D000907:Antibodies, Bacterial; D000942:Antigens, Bacterial