Highly sensitive protein translation assay for trichothecene toxicity in airborne particulates: Comparison with cytotoxicity assays

Screening assays for environmental mycotoxins in bulk samples currently use cytotoxicity in cell cultures, but their application to air particulate sa mples often lacks sensitivity and specificity for fungal spores. An assay b ased on inhibition of protein synthesis using translation of firefly lucife rase in a rabbit reticulocyte system has been developed for the detection o f trichothecene mycotoxins found in the spores of toxigenic fungi. Ethanol extracts of air particulates trapped on polycarbonate filters are ultrafilt ered and applied at several dilutions to a translation reaction mixture. Th e activity of translated luciferase is measured directly in a luminometer, eliminating the need for radioisotopes and time-consuming sample processing . Parallel standard curves using a commercially available trichothecene pro vide for expression of the results in T-2 toxin equivalents per cubic meter of air. The assay can be completed in 2 h and is readily applicable to mul tiple samples. Comparison to the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenylt etrazolium bromide cytotoxicity assay indicates a 400-fold increase in sens itivity of trichothecene detection in addition to a much higher specificity for these toxins. Initial field testing indicates a strong correlation bet ween the measured level of toxicity and the presence of toxigenic fungi det ected with microbiological methods. In conclusion, this luciferase translat ion assay offers a rapid and highly sensitive and specific method for quant itative detection of trichothecene mycotoxin activity in air particulate sa mples.