Development of Immunochromatography for Detection of Escherichia coli O157:H7 Contaminated in Meats and Sprouts

Escherichia coli O157:H7 has been considered as a significant food-borne pathogen since its role in causing hemorrhagic colitis and hemolytic uremic syndrome in humans was recognized. In this study, we developed an immunochromatography (ICG) assay for the detection of E. coli O157:H7. E. coli O157:H7 monoclonal antibody (EC MAb) and colloidal gold were conjugated and its specificity was determined by the ICG treated with EC MAb and anti- mouse IgG at test and control lines, respectively. The detection limit of the ICG was 1×10 5 CFU/mL, and no cross- reactivity was observed to other E. coli strains and major food-borne pathogens. To determine the minimum enrichment time for the ICG, meats and sprouts were inoculated with 1×10 CFU/100 µL of E. coli O157:H7. After enrichment time of 10 and 2 h for meats and sprouts, respectively, up to 1×10 CFU/100 µL of E. coli O157:H7 could be detected by ICG.