Simple and reliable enzyme-linked immunosorbent assay with monoclonal antibodies for detection of Escherichia coli heat-stable enterotoxins.
We have developed a sensitive and specific competitive enzyme-linked immunosorbent assay for Escherichia coli heat-stable enterotoxins consisting of methanol-soluble, suckling mouse active peptides with similar core sequences (STa) by using monoclonal antibodies prepared against STa purified from a human isolate. The assay can detect 3 to 20 pg of purified STa, depending on the monoclonal antibody used in the assay. The assay is rapid, requiring ca. 1 h to complete. With this competitive enzyme-linked immunosorbent assay, we measured STa production by enterotoxigenic E. coli directly in Casamino Acid-yeast extract culture supernatants. The assay was suitable for measuring STa in culture supernatants from human, bovine, and porcine E. coli isolates. No cross-reactivity was observed with heat-labile enterotoxin, cholera toxin, or heat-stable enterotoxin STb, which is a methanol-insoluble peptide(s) active in the ligated pig jejunal loop test. A 100% correlation of toxin production was found by comparing the enzyme-linked immunosorbent assay with the previously established radioimmunoassay for STa and with suckling mouse activity.
D000818:Animals; D000911:Antibodies, Monoclonal; D001427:Bacterial Toxins; D002417:Cattle; D004768:Enterotoxins / Q000032:analysis*; D004797:Enzyme-Linked Immunosorbent Assay; D029968:Escherichia coli Proteins; D006801:Humans; D011863:Radioimmunoassay; D013552:Swine
D000911:Antibodies, Monoclonal; D001427:Bacterial Toxins; D004768:Enterotoxins; D029968:Escherichia coli Proteins; C034151:heat stable toxin (E coli)