Contamination Of Grains Research Articles

RNAi-Based Approaches to Control Mycotoxin Producers: Challenges and Perspectives.

Mycotoxin contamination of food and feed is a worldwide problem that needs to be addressed with highly efficient and biologically safe techniques. RNA interference (RNAi) is a natural mechanism playing an important role in different processes in eukaryotes, including the regulation of gene expression, maintenance of genome stability, protection against viruses and others. Recently, RNAi-based techniques have been widely applied for the purposes of food safety and management of plant diseases, including those caused by mycotoxin-producing fungi. In this review, we summarize the current state-of-the-art RNAi-based approaches for reducing the aggressiveness of key toxigenic fungal pathogens and mycotoxin contamination of grain and its products. The ways of improving RNAi efficiency for plant protection and future perspectives of this technique, including progress in methods of double-stranded RNA production and its delivery to the target cells, are also discussed.

Postharvest blown-arc plasma treatment did not reduce Fusarium graminearum or its mycotoxins in field-infested wheat grain

The increasing prevalence of Fusarium graminearum, a major causative pathogen of Fusarium head blight in cereal crops, leads to contamination of grain with mycotoxins, which necessitates the development of effective management strategies. This study investigated whether postharvest Blown-Arc plasma treatment could reduce F. graminearum and associated mycotoxins in field-infested grain. Postharvest Blown-Arc plasma treatment for 60 or 180 s was trialled to reduce Fusarium graminearum and deoxynivalenol (DON) mycotoxins in field-infested wheat grain. Changes in fungal components of the grain microbiome following the treatment were assessed using metabarcoding analysis of the nuclear ribosomal internal transcribed spacer gene region, and liquid chromatography mass spectrophotometry was used to measure changes in concentrations of the mycotoxins deoxynivalenol (DON), DON-3-glucoside (DON3-G) and 3-acetyl-DON (3-ADON). Fusarium spp. were the most common taxa in the grain over two seasons, with the relative abundance being higher in 2020 (72%) compared to 2021 (45%). Postharvest plasma treatment of field-infested grain for 60 or 180 s did not significantly lower Fusarium abundance. Alpha and beta diversity of the natural mycobiota in the grain were also unaffected. The concentrations of mycotoxins were not significantly different after the treatments, except that in the 2021 trial, the 180 s treatment caused a significant increase in DON concentration. We concluded that the postharvest plasma treatment used in this study did not reduce Fusarium contamination or the concentration of mycotoxins, DON, DON3-G and 3-ADON in field-infested grain. The results highlight the importance of using field-infested grain in experiments, as opposed to grain inoculated under laboratory conditions, which provides only superficial infection. This approach is crucial for accurately understanding the dynamics of treatment efficacy.

Farmers’ willingness to adopt precision agricultural technologies to reduce mycotoxin contamination in grain: evidence from grain farmers in Spain and Lithuania

PurposeThis study examines the willingness of Spanish and Lithuanian grain farmers to adopt a combined approach of preventive site-specific spraying (PSSS) and selective harvesting (SH), two precision agricultural technologies (below referred to as PSSS-SH) aimed at mitigating the risk of mycotoxin contamination in barley and wheat.MethodsData were collected from 190 commercial grain farmers using a choice experimental survey. The empirical analysis relied on the estimation of mixed logit and integrated latent class models.ResultsThe surveyed farmers were heterogeneous in their preference for the PSSS-SH technology, with a majority (81%) reporting that they were willing to adopt and pay for the PSSS-SH technology. Furthermore, the farmers’ willingness to adopt PSSS-SH technology was influenced by the trade-offs between the potential production, economic and environmental changes.ConclusionProfit maximization is not the only motivation for a farmer’s decision to adopt PSSS-SH, there are also important non-financial benefits that align with the observed choices. Furthermore, the perceived usefulness of the technology, the willingness and readiness to use the technology, and the farmer characteristics (e.g. cooperative membership, employment status, share of household income from grain production and past experience with precision farming technology) were positively associated with uptake of the PSSS-SH technology. Therefore, extension programmes should have a special focus on the perceived usefulness of the technology, the willingness and readiness of farmers to use it, and its unique characteristics.

Isolation and molecular identification of Deoxynivalenol and Fumonisin producing genes from maize feed contaminated with Fusarium fungus in silos of dairy farms in Fars province-Iran

Mycotoxins are the toxins produced by various types of fungi, including Fusarium, which can produce different types of mycotoxins such as Deoxynivalenol (DON), Zearalenone (ZEN), T-2 toxin, and Fumonisins (FUM). Mycotoxins have the potential to reduce the quality of crops and pose health risks to both humans and animals. This can result in reduced animal production and substantial economic consequences on a global scale. Extensive research has been carried out to investigate the high incidence of contamination in grains by Fusarium fungi. In this study, 80 samples of maize from silos of dairy farms in Fars province, Iran were taken and examined for fungal contamination by Fusarium and potential production of DON and FUM. For this purpose, identification using specific primers for different genes was carried out by PCR test and gel electrophoresis with agarose (1%). Among different counties, the silos in Kharameh with 47.05% and Jahrom with 46.15% had the highest contamination rate, and the lowest contamination rate belonged to Kazeroon with 27.27%. Out of the 30 positive samples contaminated by Fusarium, 21 produced FUM, four produced DON, and five produced both toxins. Fusarium species that contaminated the maize samples were also identified, including 13, 10, and 7 samples contaminated by F. proliferatum, F. verticillioides, and F. graminearum, respectively. As a conclusion, the findings of the study indicate that 37.5% of the corn samples from dairy farm silos in Fars province were contaminated with the Fusarium fungus, which had the potential to produce the toxic mycotoxins, deoxynivalenol and fumonisins.

Edeine B1 produced by Brevibacillus brevis reduces the virulence of a plant pathogenic fungus by inhibiting mitochondrial respiration.

Plant pathogenic fungi cause serious diseases, which result in the loss of crop yields and reduce the quality of crops worldwide. To counteract the escalating risks of chemical fungicides, interest in biological control agents to manage plant diseases has significantly increased. In this study, we comprehensively screened microbial culture filtrates using a yeast screening system to find microbes exhibiting respiratory inhibition activity. Consequently, we found a soil-borne microbe Brevibacillus brevis HK544 strain exhibiting a respiration inhibitory activity and identified edeine B1 (EB1) from the culture filtrate of HK544 as the active compound of the respiration inhibition activity. Furthermore, against a plant pathogenic fungus Fusarium graminearum, our results showed that EB1 has effects on multiple aspects of respiration with the downregulation of most of the mitochondrial-related genes based on transcriptome analysis, differential EB1-sensitivity from targeted mutagenesis, and the synergistic effects of EB1 with electron transport chain complex inhibitors. With the promising plant disease control efficacy of B. brevis HK544 producing EB1, our results suggest that B. brevis HK544 has potential as a biocontrol agent for Fusarium head blight.IMPORTANCEAs a necrotrophic fungus, Fusarium graminearum is a highly destructive pathogen causing severe diseases in cereal crops and mycotoxin contamination in grains. Although chemical control is considered the primary approach to control plant disease caused by F. graminearum, fungicide-resistant strains have been detected in the field after long-term continuous application of fungicides. Moreover, applying chemical fungicides that trigger mycotoxin biosynthesis is a great concern for many researchers. Biocontrol of Fusarium head blight (FHB) by biological control agents (BCAs) represents an alternative approach and could be used as part of the integrated management of FHB and mycotoxin production. The most extensive studies on bacterial BCAs-fungal communications in agroecosystems have focused on antibiosis. Although many BCAs in agricultural ecology have already been used for fungal disease control, the molecular mechanisms of antibiotics produced by BCAs remain to be elucidated. Here, we found a potential BCA (Brevibacillus brevis HK544) with a strong antifungal activity based on the respiration inhibition activity with its active compound edeine B1 (EB1). Furthermore, our results showed that EB1 secreted by HK544 suppresses the expression of the mitochondria-related genes of F. graminearum, subsequently suppressing fungal development and the virulence of F. graminearum. In addition, EB1 exhibited a synergism with complex I inhibitors such as rotenone and fenazaquin. Our work extends our understanding of how B. brevis HK544 exhibits antifungal activity and suggests that the B. brevis HK544 strain could be a valuable source for developing new crop protectants to control F. graminearum.

Analysis of the impact of drying on common wheat quality and safety

Mycotoxin contamination in grain has been an ongoing concern in the world. Wheat, as a staple crop in China, is particularly notable for its mycotoxin contamination. The main mycotoxins in wheat include deoxynivalenol (DON) and its derivates, zearalenone (ZEN) and aflatoxin B1 (AFB1). After harvest, drying process is an effective technique and a necessary step to ensure the long-term safe storage of wheat. In this study, the moisture content, the concentrations of total fungi and main mycotoxins in post-harvest wheat of three wheat growing areas in the North China Plain were examined, and the effect of different drying methods on wheat quality was evaluated. The results showed that 87.5% of wheat samples were simultaneously contaminated with two or more mycotoxins. Due to the pre-harvest heavy rainfall, the moisture content, the levels of total fungi and mycotoxins in wheat samples of Liaocheng city were significantly higher compared to other regions. Moreover, the effects of different drying methods on the starch gelatinization and viscosity properties of wheat were investigated. The results showed that both natural air drying and dryer drying altered the crystal structure within starch particles and affected the gelatinization and viscosity properties of wheat starch. However, there is no significant difference between the wheat samples treated with two drying methods.

Evaluation of Pesticides and Trace Metal Contaminants in Grains, Fresh Fruits and Vegetables from Odoluwa Market Ile Oluji; Ondo State Nigeria

Vegetables, fruits and grains are sources of food rich in vitamins, minerals, and fibers and also have beneficial ant oxidative effects Pesticides and trace metals typically contaminate these food products. Pesticides and trace metals are not biodegradable and have the potential for accumulation in different body organs, leading to unwanted side effects This study investigated the concentration of pesticide residues and some selected Trace metals in Vegetables, fruits and grains from Odolua market Ile-Oluji Ondo State. Samples were collected randomly from the market, representative portion of the samples was chopped into small pieces and blended using a blender..Quantitative determination of the pesticide for Herbicides, organochlorine and organophosphate was carried out using Gas Chromatography-Mass Spectrometer after liquid-liquid extraction. Trace Metal was determined using Inductively coupled plasma - optical emission spectrometry (ICP-OES). The results reveal the presence of pesticide residues in all the samples. The mean concentration of pesticides in the samples was below the maximum residue limits (MRs) value for World health organization (WHO) while some were higher. The results also shows that all the trace metals analyzed are present in the samples except for Cadmium which is below the detection limit while Lead and Cobalt are only detected in one sample each. Some concentrations of the trace metals were below the permissible limit for WHO while others were higher than the permissible limit.

Ecological Traits and Socio-Economic Impacts of the Alien Invader Weed Parthenium hysterophorus L. in South Africa’s Rangeland Ecosystems: A Review

Parthenium hysterophorus L. (Asteraceae), commonly known as famine weed in South Africa, is one of the most invasive weeds worldwide, accountable for losses to biodiversity, agriculture, the economy, and the health of livestock and human beings. The spread of this weed is not easy to manage or reverse. With globalization, trade, and human movement, it will continue to spread, allowing its range to expand into new areas. This weed has serious adverse effects on rangeland and agricultural crop production. Because of its unique characteristics, its invasiveness and competitive success rates are attributed to its high reproductive ability, fast growth rate, tolerance to environmental stresses, climate change adaptability, allelopathic potential, and unpalatability to animals. Parthenium hysterophorus dominates diverse habitats by spreading quickly as a contaminant of grain and other crop products and through farm machinery. It is widely distributed and has become problematic in various countries, including South Africa. It has successfully invaded several provinces in the country since its introduction in 1880. Since plant invasions are not universal, this study aimed to review research that has been conducted on the aggressive weed P. hysterophorus to understand the ecological characteristics that enable its successful establishment, the economic costs associated with its detrimental impacts, and to briefly assess knowledge gaps to improve its management strategies.

Identification and characterization of Achromobacter spanius P-9 and elucidation of its deoxynivalenol-degrading potential.

Deoxynivalenol (DON) poses significant challenges due to its frequent contamination of grains and associated products. Microbial strategies for mitigating DON toxicity showed application potential. Eight bacterial isolates with DON degradation activity over 5% were obtained from various samples of organic fertilizer in this study. One of the isolates emerged as a standout, demonstrating a substantial degradation capability, achieving a 99.21% reduction in DON levels. This isolate, underwent thorough morphological, biochemical, and molecular characterization to confirm its identity, and was identified as a new strain of Achromobacter spanius P-9. Subsequent evaluations revealed that the strain P-9 retains its degradation activity after a 24-h incubation, reaching optimal performance at 35°C with a pH of 8.0. Further studies indicated that Ca2+ ions enhance the degradation process, whereas Zn2+ ions exert an inhibitory effect. This is the pioneering report of DON degradation by Achromobacter spanius, illuminating its prospective utility in addressing DON contamination challenges.

Acetyl-CoA carboxylase as potential molecular target of dimethyl trisulfide on inhibiting the Aspergillus flavus growth and aflatoxins production

Aspergillus flavus and the produced aflatoxins are common hazardous contaminants in grains and food, which generated great damage to food security and human health. Acetyl-CoA carboxylase (ACC), catalyzing acetyl-CoA to malonyl-CoA, is the first and speed-determining step in fatty acid biosynthesis (cell membrane composition) and aflatoxins biosynthesis process in A. flavus. Here, we demonstrated that dimethyl trisulfide (DMTS), emitted from bacteria, could interact with ACC, decrease the enzymatic activity from 377.62 to 191.42 kat/g in vitro, down-regulate the expression of ACC and other important genes in fatty acid and aflatoxin biosynthesis pathway, reduce the content of hexadecanoic acid, octadecanoic acid and eicosanoic acid, and finally prevent A. flavus growth and aflatoxins production. Two binding sites containing 19 amino acids were detected between DMTS and ACC through molecular docking analysis. These amino acids were highly conserved in different filamentous fungi, which accounted for the broad antifungal spectrum of DMTS. Therefore, we concluded that ACC is the molecular target of DMTS on A. flavus growth and aflatoxins production. These results elucidate the inhibitory mechanism of DMTS on fungal pathogens, and provide basic theories for the development of novel antifungal agents.

The effectiveness of bacterial contamination of beetles during their transfer to wheat bran

The study of the mechanisms of transfer of bacteria during contamination of insect surfaces during food invasion is of current interest. Additionally, the increasing antibiotic resistance of clinical bacterial strains over the past decade has highlighted the importance of understanding the mechanisms of bacterial circulation among insects, especially antibiotic-resistant strains. Our modeling study demonstrates that the transfer of the Escherichia coli Rif (+) marker strain on the surface and inside the intestine of adult beetles Tenebrio molitor contributes to bacterial contamination of wheat bran. The isolation of E. coli Rif (+) in high titers from the beetle’s surface and feces continued for three days. The ability of beetles to carry allochthonous bacteria on their surface and inside their intestines can contribute to contamination of grains, flour, and wheat bran with antibiotic-resistant bacterial strains. In the future, the use of the Escherichia coli Rif (+) strain may help to better understand the mechanisms of how insects transfer antibiotic-resistant bacteria from one place to another during their invasion of food sources.

Reducing cadmium accumulation and increasing grain yield with proper timing of flood irrigation in the second season of ratoon rice

Context or problemThe second season of ratoon rice (ratoon crop, RC) exhibits a high risk of cadmium (Cd) contamination in grains, requiring effective irrigation management strategies to reduce its grain Cd concentration. Objective or research questionThis study aimed to determine the crucial growing period for Cd accumulation and provide irrigation recommendations for reducing grain Cd concentrations with limited water input in the ratoon season. MethodsA two-year field experiment was conducted in Hubei province, central China. The entire growth duration of RC was divided into three short periods: from harvest of the main crop (HM) to initial heading of RC (IH), from IH to full heading of RC (FH), and from FH to maturity of RC (MR). During each growth period of RC, two water regimes (flooded and rainfed) were established. Therefore, there were a total of eight water treatment combinations in this experiment, using a randomized complete block design. Two hybrid varieties were planted in this study. ResultsAcross years, varieties and treatments, the grain Cd concentration of RC ranged from 27.8 to 314.1 µg kg−1, with 37.5% of rice samples exceeding the national food safety standard for Cd (200 µg kg−1). RC grown under continuous flooding conditions produced the lowest grain Cd concentration and highest grain yield. Compared with rainfed conditions, maintaining flooded conditions from HM to IH, from IH to FH, and from FH to MR resulted in decreases of 28.4%, 62.7%, and 12.0% in grain Cd concentration and decreases of 25.5%, 49.9%, and 16.3% in total Cd accumulation at maturity, respectively. RC took up the most Cd during the period from IH to FH under rainfed conditions; however, maintaining flooded conditions reduced Cd uptake by 95.4% during this period. Moreover, flooding from IH to FH had the most positive impact on the grain yield of RC, with an increase of 8.1% compared with rainfed conditions. ConclusionsMaintaining flooded conditions from initial to full heading for 15–18 days was not only effective in reducing grain Cd concentration but also beneficial for improving grain yield in the ratoon season. Implications and significanceThis study clarified the effects of water management during different growing periods on Cd accumulation and grain yield in the ratoon season. We emphasized the necessity of flooding during heading period to control Cd accumulation in RC grains, especially in areas with limited water resources and high soil Cd concentration.

Evaluation of mycotoxins in grains sold in Idah, Ajaka and Ogbogbo areas of Nigeria.

Mycotoxin contamination in grains is a significant concern due to its adverse effects on human and animal health. Understanding the levels and patterns of mycotoxin contamination in different regions and storage conditions is crucial for developing effective control strategies. This study aimed to assess mycotoxin levels in stored and recently harvested grains in three regions (Idah, Ajaka, and Ogbogbo) and investigate the implications for food safety. The study involved the analysis of mycotoxin levels in maize, rice, sorghum, and millet using appropriate mycotoxin extraction method based on the mycotoxins of interest and a suitable HPLC system. The findings revealed the presence of mycotoxins such as aflatoxins (1±0.2-5±0.4 µg kg-1), deoxynivalenol (520±0.8-700±1.2 µg kg-1), zearalenone (200±0.4-370±0.6 µg kg-1), ochratoxins (2±0.2-4±0.3 µg kg-1), and fumonisin (0±0.0-4±0.3 µg kg-1) in both recently harvested and stored grains. Patulin was absent in most of the samples. Variations in mycotoxin levels were observed among different grains and regions, highlighting the need for targeted interventions. The European Commission mycotoxin standards in grains for human consumption are: aflatoxins 4 µg kg-1 in maize, millet and sorghum while rice is 8 µg kg-1, deoxynivalenal 1750 µg kg-1, zearalenone 100 µg kg-1, ochratoxin A 5 µg kg-1 for maize, rice and millet, then 10 µg kg-1 for sorghum. Fumonisin is 4000 µg kg-1 but no level for rice and patulin is 50 µg kg-1 for rice and none for the other grains. This study demonstrates the persistence of mycotoxin contamination in stored grains and the importance of considering specific crop types and geographical locations when addressing mycotoxin contamination. The findings underscore the significance of implementing effective control measures to mitigate mycotoxin contamination and enhance food safety. The study provides valuable insights into mycotoxin contamination and emphasizes the need for comprehensive risk assessment studies and appropriate regulatory measures.

Effect of heavy metal ions on rice protein fibrillation: Structure, morphology, and functionality

Heavy metal ions, the common contaminants in grain growing environment and food processing, pose an important effect on the aggregation behavior of food proteins. In this work, the effects of heavy metal ions Zn2+, Cd2+ and Cu2+ on rice protein (RP) fibrillation were investigated, and the relationship between fibril structures, morphology and functional properties was also discussed. Specifically, Zn2+ and Cd2+ not only facilitated the formation of rice protein fibrils (RPFs) by promoting the generation of β-sheet structures (57.3% and 54.4%, respectively), but also transformed the fibrils into long and straight rigid structures. Cu2+ led to more disordered structures (23.1%), inhibited RP fibrillation and induced branching/tangling structure. The result of the intrinsic fluorescence showed that Cu2+ could obviously decrease the fluorescence intensity of RPFs, indicating that the microenvironment of RP was changed by Cu2+. Correspondingly, Zn2+ and Cd2+ improved the solubility, emulsifying and foaming properties of RPFs, while Cu2+ enhanced the rheological properties.

Contamination and persistence of polycyclic aromatic hydrocarbons (PAHs) in rice grains after drying in direct-fired dryer.

The objective of this work was to study PAHs contamination in rice grains subjected to different milling types, after drying at different air temperatures in a direct-fired dryer and using firewood with different moisture contents as a heating source. In addition to verifying the persistence of these compounds after storage. Drying of rice grains was performed in a cross-flow dryer at air temperatures of 55 and 65ºC. As heating source firewood containing different moisture contents was used. The presence of nine PAHs was detected. The drying air temperature, as well as the storage time, did not significantly influence the PAHs contamination of grains. The highest PAHs contamination was observed in grains from the brown subgroup. Grain polishing promoted a reduction in the PAH concentration. The grains subjected to parboilization showed a higher PAHs concentration. The use of firewood with higher moisture content promoted greater PAHs contamination in the grains.

Development and Validation of a TaqMan Multiplex Real-Time PCR Assay for High-Throughput Quantification of Fusarium graminearum Biomass in Barley Spikes and Grains

Fusarium head blight (FHB) is a devastating disease primarily caused by Fusarium graminearum that commonly affects North American small grains. Although the disease causes visible symptoms, the more pressing concern is the contamination of grain with trichothecene toxins, especially deoxynivalenol (DON), which can cause toxicity in humans and animals by inhibiting protein biosynthesis. The DON levels are more critical when breeding for resistance, but this does not account for pathogen infection and disease severity. To link DON and Fusarium infection, we optimized and validated a real-time multiplex quantitative PCR protocol for high-throughput quantification of Fusarium biomass based on the Tri5 gene, which encodes trichodiene synthase, the first enzyme involved in trichothecene toxin production. The primers and probes were designed to measure the abundance of Tri5 and normalized to the barley actin gene. The assay is repeatable, robust, and sensitive, up to 0.003 ng/µl of F. graminearum and 0.3 ng/µl of barley DNA. The method is cost-effective and has the potential to quantify Fusarium biomass, monitor disease progression, and determine DON levels in barley spikes and harvested grains. [Formula: see text] Copyright © 2024 The Author(s). This is an open access article distributed under the CC BY-NC-ND 4.0 International license .

Role of mitochondrial farnesyltransferase gene in the prevention of the food spoilage fungi Aspergillus flavus by the antimicrobial natural preservative perillaldehyde

Aspergillus flavus, one of the most widely distributed and abundant genus of Aspergillus worldwide, poses an evident threat as a source of food contamination in grains and cereals. Perillaldehyde (PAE), a volatile essential oil extracted from the stem and leaves of Perilla frutescens L., exhibits potent antifungal activity. In our study, we investigated the role of Cox10, a key enzyme in the heme A synthesis pathway crucial for maintaining mitochondrial function. We found that cox10 is a sensitive gene of A. flavus in response to PAE by gene expression assay and GFP fluorescent localization tagging, and then we found that the deletion of this gene affects the growth and development of A. flavus, but the drug resistance is elevated. Through transcriptome sequencing and its experimental validation, the molecular mechanisms of stress triggered by the deletion of cox10 were further clarified, such as the decrease in intracellular drug content due to the increase in the expression of drug efflux proteins, and the increase in the thickness of cell wall due to the increase in the content of cell wall chitin. Clearly, cox10 plays a critical role in regulating various cellular processes of A. flavus, including growth, reproduction, development, as well as pathogenicity and drug resistance. These significant findings establish a solid theoretical foundation for the development of environmentally friendly, safe, and effective antifungal agents to combat A. flavus contamination.

Elevated CO2 Can Worsen Fusarium Head Blight Disease Severity in Wheat but the Fhb1 QTL Provides Reliable Disease Resistance.

Fusarium head blight (FHB) is a destructive fungal disease of wheat that causes significant economic loss due to lower yields and the contamination of grain with fungal toxins (mycotoxins), particularly deoxynivalenol (DON). FHB disease spread and mycotoxin contamination has been shown to worsen at elevated CO2, therefore, it is important to identify climate-resilient FHB resistance. This work evaluates whether wheat with the Fhb1 quantitative trait locus (QTL), the most widely deployed FHB resistance locus in wheat breeding programs, provides reliable disease resistance at elevated CO2. Near-isogenic wheat lines (NILs) derived from either a highly FHB susceptible or a more FHB resistant genetic background, with or without the Fhb1 QTL, were grown in growth chambers at ambient (400 ppm) and elevated (1000 ppm) CO2 conditions. Wheat was inoculated with Fusarium graminearum and evaluated for FHB severity. At elevated CO2, the NILs derived from more FHB-resistant wheat had increased disease spread, greater pathogen biomass and mycotoxin contamination, and lower rates of DON detoxification; this was not observed in wheat from a FHB susceptible genetic background. The Fhb1 QTL was not associated with increased disease severity in wheat grown at elevated CO2 and provided reliable disease resistance.

Low dose dietary contamination with deoxynivalenol mycotoxin exacerbates enteritis and colorectal cancer in mice

BackgroundThe mycotoxin deoxynivalenol (DON) is a frequent contaminant of grain and cereal products worldwide. Exposure to DON can cause gastrointestinal inflammation, disturb gut barrier function, and induce gut dysbiosis in vivo under basal conditions, but little is known about the effects of DON ingestion in individuals with pre-existing gastrointestinal disease. ObjectivesMice were orally exposed to 10 and 100 μg/kg bw/day of DON, corresponding to 10 to 100-fold human tolerable daily intake concentrations, and to the translation in mice of current human daily intake. The effects of DON exposure were explored under steady-state conditions, and in murine models of enteritis and colorectal cancer (CRC). ResultsAfter 8 days of DON exposure, an increase of histomorphological and molecular parameters of epithelial proliferation were observed in normal mice, from the duodenum to the colon. The same exposure in a murine model of indomethacin-induced enteritis led to exacerbation of lesion development and induction of ileal cytokines. DON exposure also worsened the development of colitis-associated CRC in mice as shown by increases in endoscopic and histological colitis scores, tumor grades, and histological hyperplasia. In colon of DON-exposed mice, upstream and downstream ERK signaling genes were upregulated including Mapk1, Mapk3, Map 2k1, Map2k2 core ERK pathway effectors, and Bcl2 and Bcl2l1 antiapoptotic genes. The effects observed in the CRC model were associated with alterations in cecal microbiota taxonomic composition and metabolism of bacterial fucose and rhamnose. Strong Spearman's correlations were revealed between the relative abundance of the changed bacterial genera and CRC-related variables. DiscussionIngestion of DON mycotoxin at concentrations representative of human real-world exposure worsened the development of indomethacin-induced enteritis and colitis-associated CRC in mice. Our results suggest that even at low doses, which are currently tolerated in the human diet, DON could promote the development of intestinal inflammatory diseases and CRC.

Assessing aflatoxin safety awareness among grain and cereal sellers in greater Accra region of Ghana: A machine learning approach

Studies have established high prevalence of aflatoxin contamination in grains and cereals produced in Ghana. Mitigation strategies have focused mainly on capacity building for farmers, agricultural extension officers, bulk distributors and processors to the detriment of the market women who act as the final link between consumers and producers. This study used supervised machine learning algorithms by means of Classification and Regression Trees (CART) to investigate aflatoxin knowledge and awareness of market women in Greater Accra Region of Ghana. A cross-sectional survey and probability sampling methods were employed for data collection. Ninety-two (92%) of participants had never heard about aflatoxins and yet, 62% reported that they usually observe mould growth in their cereals/grains. Unsurprisingly, 97% of participants indicated that they had no knowledge of the aflatoxin bill passed by the government of Ghana parliament. Despite participants not being aware of aflatoxin menace, the percent correctness of their aflatoxin safety measure score was 40%. A regression tree algorithm showed that, participant's ethnic group was the most significant parameter to consider regarding their aflatoxin safety knowledge. Their educational background and age were 95.5% and 72.5% as significant as their ethnic group. A classification tree algorithm showed that, educational level was the most significant parameter to consider when it comes to sorting of grains/cereals. Their ethnic group and marital status were 92.4% and 89.3% as important as educational level. It is therefore imperative for the Ghana government to extend sensitization and awareness programs to these market women, targeting the uneducated and specific age and ethnic groups.