Abstract # A-48

Rapid Detection of Type A Cultural Botulinal Toxin from Cheese Samples using an Amplified ELISA System. J. L. Ferreira and R. G. Crawford. ORA, FDA, Southeast Regional Lab., Atlanta, GA

Cheese samples were inoculated into tryptone-peptone-glucose-yeast extract toxin-production media, incubated for seven days, and then assayed for toxin comparing the amplified ELISA and the mouse bioassay. The culture supernatants were tested for type A, B, E, and F botulinal toxins. The amplified ELISA system indicated the product contained type A botulinal toxin-producing organisms that produced greater than 1,000 MLD/ml in the culture. No cross-reactivity was noted between the toxic cultures and the other ELISA test types B, E, or F. The sensitivity of this one day ELISA test was ~10 MLD/ml of culture fluid compared to the mouse bioassay test (1 MLD/ml). The advantages of this test are that the toxin type and approximate lethal dose are rapidly determined (one day) compared to longer analytical time (3-5 days) and the necessity of using animals by the classical procedure. The procedure is also useful for the identification of toxin-producing botulinal isolates obtained from agar plates.