Lateral flow assay for rapid detection of Staphylococcus aureus enterotoxin A in milk

Staphylococcus aureus is closely associated with food poisoning incidences, more, because of intoxication due to contamination of food with its enterotoxins. Staphylococcus enterotoxin A (SEA) is highly resistant to heat and other food processing conditions and has been implicated in food borne diseases from dairy products. Here we describe a rapid, gold nanoparticle based lateral flow immunoassay (LFIA) for detecting SEA in milk. Assay is in sandwich format and uses two specific monoclonal antibodies against SEA, one of which is labeled with gold nanoparticles and other is immobilized at control line. We also demonstrate the effect of using a combination of additives in capture antibody in order to enhance assay sensitivity. The developed LFIA is specific and has a lower detection limit of 0.5 mu g/ml. LFIA is tested both on spiked buffer and milk samples and display good reproducibility. The assembled strips stable for a month at 4 degrees C. The method may be suitable for testing SEA in milk samples as it is quick, easy to perform and reproducible. (C) 2017 Elsevier B.V. All rights reserved.