Development of a Bead-Based Multiplex Assay for the Simultaneous Quantification of Three Staphylococcal Enterotoxins in Food by Flow Cytometry

Food-borne diseases are widespread; one of the reasons is contamination with staphylococcal pathogens that can produce enterotoxins of the protein, causing numerous diseases in humans. The long-term stability of the toxins requires that the methods for foodstuff quality control be refined to prevent contamination with staphylococcal enterotoxins. We developed a bead-based multiplex assay for the simultaneous detection of three staphylococcal enterotoxins (staphylococcal enterotoxin A (SEA), staphylococcal enterotoxin B (SEB), staphylococcal enterotoxin H (SEH)) by flow cytometry. For detection, we used functional beads coupled with monoclonal capture antibodies, biotinylated monoclonal detection antibodies, and streptavidin conjugated to phycoerythrin. The linear ranges of detection of SEA, SEB, and SEH were 0.02-20 ng/mL, 0.2-30 ng/mL, and 0.2-20 ng/mL, respectively. Each toxin was specifically detected without cross-reactions. An efficient use of the developed method for the analysis of foodstuffs was reported.