Antibody-based detection of acid-shocked, acid-adapted, and apple juice-incubated Escherichia coli O157:H7

Sandwich enzyme-linked immunosorbent assays (sELISA) allow for rapid detection of Escherichia coli (E. coli) O157:H7. Acidic conditions similar to those in certain foods and juices may reduce the ability to detect E. coli O157:H7. Growth of E. coli O157:H7 at pH 4 compared to pH 5-7 reduced fluorescent signal at the lower bacterial concentrations without altering the range of detection. Both acid-adaptation and a subsequent pH 7 incubation reversed sensitivity. Incubation in apple juice was not deleterious to sELISA detection. Exposure to acidic conditions can cause a small reduction in sELISA sensitivity used to detect E. coli O157:H7.