Evaluation of enzyme-linked immunosorbent assay (ELISA) for detection of staphylococcal enterotoxin in foods.

Two ELISA kits were employed to detect staphylococcal enterotoxin A, B, C and D in foods to which enterotoxin had been added or which had been artificially contaminated with enterotoxin-producing strains of Staphylococcus aureus. The sensitivity was satisfactory, and enterotoxins were detected by both ELISA kits in all positive samples. Weak positive reactions with one ELISA kit caused some difficulties in evaluation of samples. Enterotoxins A, B and C detected in small amounts (2-22 ng/ml) in minced fried beef were not detectable after heating at 80 degrees C, whereas enterotoxin D detected in considerably greater amounts (783 ng/ml) was reduced to 0.4% of this amount.