Mycotoxins: Biosecurity and Food Safety

NON-TECHNICAL SUMMARY: Mycotoxins are metabolites of fungi that can adversely affect animal and human health. Mycotoxins can be produced in grain during storage or processing, but are most frequently associated with fungal infection that occur before harvest. Environmental factors that determine fungal infection and mycotoxin production are complex. Generally, a basal level of mycotoxins is present in US grain; however, in some years, environmental conditions lead to localized or widespread outbreaks of mycotoxin contamination. However, there is no organized monitoring system for tracking the incidence and severity of mycotoxin contamination at either the national or regional levels. Although breeding and transgenic technologies have shown promise for reducing the risk of mycotoxin contamination of grain, to date no commercial variety of any major US crop is available with either genetic or transgenic resistance to mycotoxin contamination. This project will address the needs of the stakeholders as follows. First, the research will advance detection technologies that can be used by private companies which provide mycotoxin analysis services to food industries. This will include development of new techniques and validation of their current methodology. Second, the research will generate new protocols for monitoring mycotoxins in agricultural products that will be incorporated by biosecurity agencies. Third, US and international government policy makers (USFDA, JECFA, IARC) will use our research information in their risk assessments for mycotoxins. The outcome of risk assessment has been government recommendations on maximum mycotoxin levels for agriculture products, which affects national and international use of products. Finally, we anticipate that our research information will have a major impact on the decision making by providing mode of toxicity data, survey data, and data aimed at understanding how food components affect mycotoxin biosynthesis. <P>

APPROACH: <BR> Objective 1 deals with the need for information applicable to the risk assessment process. The research team working on this objective will look specifically at the toxic effects of fumonisin and fumonisin conjugates. Animal models, target species and cell cultures will be used to determine the effects of the mycotoxin on the whole organism, target organs, cellular and subcelluar changes, and gene expression. <BR>Objective 2 addresses the stakeholders' continuing need for new detection methods. A team of researchers will 1) evaluate new antibodies to detect the presence of fumonisin, DON and other mycotoxin analogs present after processing, 2) develop a library of PCR primers for detecting mycotoxigenic fungi, and 3) develop and evaluate optical detection technology that detects fungal-contaminated commodities. In addition, this NC group of experts will serve as an unique resource to address mycotoxin issues as they relate to potential bioterrorism or outbreaks of plant, animal or human disease. No other such group exists in the US. <BR>Objective 3 will evaluate the efficacy of various management procedures, including physical, chemical, and biological approaches, to help prevent mycotoxin-related problems during grain handling, storing, processing and feeding. <BR>Finally, the goal of the team working on Objective 4 is to provide basic knowledge about the biochemical and molecular factors that regulate the biosynthesis of aflatoxins and fumonisins. As one example, researchers will collaborate to 1) generate disruption mutants for genes expressed during fumonisin biosynthesis and 2) evaluate gene expression profiles in wild type and the fck1 mutant of F. verticillioides cultured on various corn kernel tissues. This will reveal critical points in the regulation where targeted inhibitors could be designed.