Scientific Publications by FDA Staff

Appl Environ Microbiol 2013 Mar;79(5):1422-7

Novel platform for the detection of Staphylococcus aureus enterotoxin B in foods.

Tallent SM, Degrasse JA, Wang N, Mattis DM, Kranz DM

Staphylococcal contamination of food products and staphylococcal foodborne illnesses continue to be a problem worldwide. Screening food for the presence of Staphylococcal aureus and/or enterotoxins using traditional methods is laborious. Reliable and rapid multiplex detection methods from a single food extract or culture supernatant would simplify testing. A fluorescence-based cytometric bead array was developed for the detection of staphylococcal enterotoxin B (SEB) using magnetic microspheres coupled with either an engineered, enterotoxin specific, Vbeta domain of the T-cell receptor (Vbeta TCR) or polyclonal antibodies. The binding affinity of the Vbeta TCR SEB has been shown to be in the picomolar range, comparable to the best monoclonal antibodies. The coupled beads were validated with purified enterotoxins and tested in a variety of food matrices spiked with enterotoxins. The Vbeta TCR or antibody was shown to specifically bind SEB in four different food matrices including milk, mashed potatoes, vanilla pudding and cooked chicken. The use of traditional polyclonal antibodies and Vbeta TCR provides a redundant system that ensures accurate identification of the enterotoxin and the use of labeled microspheres permits simultaneous testing of multiple enterotoxins from a single sample.