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United States Department of Agriculture

Agricultural Research Service

Research Project: INNOVATIVE MATERIALS FOR USE IN MYCOTOXIN DETECTION

Location: Bacterial Foodborne Pathogens & Mycology Research Unit

Title: Detection of “masked” trichothecenes by immunoassay

Author
item Maragos, Chris

Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: January 31, 2014
Publication Date: January 31, 2014
Citation: Maragos, C.M. 2014. Detection of “masked” trichothecenes by immunoassay [abstract]. U.S.-Japan Panel on Toxic Microorganisms.

Technical Abstract: Plants, animals, and microbes can metabolize toxic compounds oftentimes adding polar groups such as sulfates or sugars. Generally such metabolism is considered detoxification, because it may make the toxin more easily excreted or prevent it from interacting with its main target site. Such metabolites are often not detected by commonly used methods that have been designed to detect the original ‘parent’ toxins. These types of metabolites have been termed “masked”, to imply that they are hidden from the most commonly used analytical methods. Although novel (undiscovered) toxins might also be considered as hidden, the masked mycotoxins are generally distinguished as being metabolites or precursors of known toxins. In addition to concern about the toxicity of the masked mycotoxins themselves, there is concern about the possibility that they may be metabolized back to the parent toxin. That is, that they might serve as reservoirs of the toxin. Trichothecene mycotoxins, such as T-2 toxin and deoxynivalenol (DON), are common contaminants of commodities and foodstuffs. Recently the glucosides of T-2 toxin and related HT-2 toxin were discovered in fungal cultures and their presence was detected in wheat and oats. These “masked” forms of T-2 and HT-2 can be detected using chromatographic methods such as LC-MS/MS. However, because of costs or because they do not have access to the instrumentation or the trained personnel needed for such analyses, many laboratories use antibody-based methods for detection. This is particularly true where large numbers of samples need to be tested rapidly and inexpensively. In those situations an antibody-based method that could detect masked mycotoxins might be useful. To help detect masked forms of T-2 toxin, we developed several antibodies capable of binding both the T2-glucosides and the unconjugated T-2 toxin. Ten antibodies were developed and evaluated using an enzyme linked immunosorbent assay (ELISA) format. The most sensitive of these antibodies, which cross-reacted well with T-2 toxin, was also evaluated in a biosensor format. The biosensor, based upon the principle of biolayer interferometry, allowed multiple samples to be tested simultaneously. The strong cross-reactivity of the assay with both T-2 toxin and its glucoside suggests that detection of the two analytes together, as a combined response, may be feasible.

Last Modified: 11/20/2014
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