Fluorescence polarization immunoassay for the determination of T-2 and HT-2 toxins and their glucosides in wheat

Authors: LIPPOLIS, VINCENZO - Institute Of Sciences Of Food Production; PORRICELLI, ANNA - Institute Of Sciences Of Food Production; MANCINI, ERMINIA - Institute Of Sciences Of Food Production; CIASCA, BIANCAMARIA - Institute Of Sciences Of Food Production; LATTANZIO, VERONICA - Institute Of Sciences Of Food Production; DE GIROLAMO, ANNALISA - Institute Of Sciences Of Food Production; Maragos, Chris; McCormick, Susan; LI, PEIWU - Chinese Academy Of Agricultural Sciences; LOGRIECO, ANTONIO - Institute Of Sciences Of Food Production; PASCALE, MICHELANGELO - Institute Of Sciences Of Food Production

Submitted to: Toxins
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/18/2019
Publication Date: 7/1/2019
Citation: Lippolis, V., Porricelli, A.C.R., Mancini, E., Ciasca, B., Lattanzio, V.M.T., De Girolamo, A., Maragos, C.M., McCormick, S., Li, P., Logrieco, A.F., Pascale, M. 2019. Fluorescence polarization immunoassay for the determination of T-2 and HT-2 toxins and their glucosides in wheat. Toxins. 11(7):380. https://doi.org/10.3390/toxins11070380.
DOI: https://doi.org/10.3390/toxins11070380

Interpretive Summary: The trichothecenes are toxins that can be produced by fungi that infest oats, wheat, barley, and corn. They are distributed throughout the world and are therefore of international concern. As part of efforts to improve monitoring of these toxins, a method for detecting some of their members (T-2 and HT-2 toxins) in wheat using fluorescence polarization immunoassay (FPIA) was developed at the Institute of Sciences of Food Production (ISPA) in Bari, Italy, with help from scientists with ARS in Peoria, IL. Advantages of the FPIA technology are speed and ease of use. The technique was successfully used to measure T-2 toxin, HT-2 toxin, and related metabolites in wheat. The result is a rapid, sensitive, and easy to use method that can be applied to the monitoring of these toxins in wheat.

Technical Abstract: T-2 and HT-2 toxins and their main modified forms (T-2 glucoside and HT-2 glucoside) may co-occur in cereals and cereal-based products. A fluorescence polarization immunoassay (FPIA) was developed for the simultaneous determination of T-2 toxin, HT-2 toxin and relevant glucosides, expressed as sum. The developed FPIA, using a HT-2-specific antibody, showed high sensitivity (IC50=2.0ng/mL) and high cross-reactivity (100% for T-2 toxin and 80% for T-2 and HT-2 glucosides). The FPIA has been used to develop two rapid and easy-to-use methods using two different extraction protocols, based on the use of organic (methanol/water, 90:10v/v) and non-organic (water) solvents, for the determination of these toxins in wheat. The two proposed methods showed analytical performances in terms of sensitivity (LOD 10 µg/kg) recovery (92-97%) and precision (relative standard deviations = 13%) fulfilling the criteria for acceptability of an analytical method for the quantitative determination of T-2 and HT-2 toxins established by the European Union. Furthermore, the methods were then validated in accordance with the harmonized guidelines for the validation of screening methods included in the Regulation (EU) No 519/2014. The satisfactory analytical performances, in terms of intermediate precision (= 25%), cut-off level (80 and 96 µg/kg for the two methods) and rate of false positives (< 0.1%) confirmed the applicability of the proposed methods as screening method for assessing the content of these toxins in wheat at the EU indicative levels reported for T-2 and HT-2 toxins.