A biosensor method for detection of staphylococcal enterotoxin A in raw whole egg

Abstract

Staphylococcal enterotoxin A (SEA) is the most commonly recovered staphylococcal enterotoxin in food poisoning outbreaks. Our research objective was to develop a competitive immunoassay using a surface plasmon resonance (SPR) biosensor for the detection of SEA in raw eggs. Homogenized raw eggs were spiked with SEA and clarified by centrifugation at 14,989 × g. Anti-SEA was added to aliquots of the egg supernatants allowing SEA to bind with anti-SEA. The bound complex was separated from the free immunoglobulin G (IgG) by centrifugation. The supernatant was automatically sampled and injected over the SEA sensor surface of the SPR system. The IgG-bound response units were plotted against spiked SEA concentration. SEA was detected in whole egg at 1-40 ng/mL (ppb). The biosensor analysis including the sensor regeneration was 15 min per sample in an automated system. This biosensor assay can be utilized for SEA detection in liquid eggs. © 2006, The Author(s).