Presence Of Deoxynivalenol Research Articles

Separation and quantification of mycotoxins in floral tissue of hemp (Cannabis sativa) infected with Fusarium graminearum

AbstractBackgroundThe fungal pathogen Fusarium graminearum produces mycotoxins when it infects grains. This pathogen also infects hemp (Cannabis sativa L. containing less than 0.3% tetrahydrocannabinol or THC). The presence of trichothecene mycotoxins like deoxynivalenol (DON) has not been reported in floral tissue of hemp infected with F. graminearum. The object of this study was to develop a method to extract three trichothecene mycotoxins—DON, 3‐acetyldeoxynivalenol (3‐ADON), and 15‐acetyldeoxynivalenol (15‐ADON)—from hemp floral tissue, and to quantify the mycotoxins by high‐performance liquid chromatography (HPLC) with ultraviolet detection.ResultsStandards of nivalenol (NIV), DON‐3‐glucoside (D3G), DON, 3‐ADON, and 15‐ADON were separated from each other and from standards of several cannabinoids. Standard curves were linear (R‐squared values >0.99). Recoveries from hemp spiked with 36 μg/g mycotoxins were 86%–90% for DON, 75%–77% for 15‐ADON, and 86%–101% for 3‐ADON. In extracts of hemp inflorescences infected with different strains of F. graminearum (15‐ADON chemotypes), DON was detected in one sample. Other samples contained 15‐ADON but no detectable DON, or neither mycotoxin in detectable amounts.ConclusionMycotoxins were separated from cannabinoids. DON was also separated from matrix components, and 15‐ADON and 3‐ADON were partially separated from matrix components. The presence of DON in hemp may depend on fungal strain or stage of disease development, as well as the sensitivity of the method. The current method could quantify DON and 15‐ADON at about 3 μg/g in hemp floral tissue, and 3‐ADON at about 6 μg/g.

A highly sensitive SERS aptasensor using a novel truncated aptamer for the detection of Deoxynivalenol

Deoxynivalenol (DON) is a common mycotoxin in nature, which is not only widely distributed, but also can cause human and animal poisoning, posing a serious threat to food safety and social economy. Therefore, it is very important to develop a sensitive and stable method to detect DON. In this research, the optimal aptamer D40 was obtained by molecular docking prediction and truncation based on molecular docking results. Then, we labeled the Cy3 Raman reporter molecule with D40, as a capture probe for the aptasensor. Finally, the porous π-rich structure Cu@C derived from the thermal decomposition of CuBTC is combined with AuNPs to generate abundant hot spots, and the Cy3-aptamers are adsorbed to the composite by the π-π to produce sharp and significant Raman signals. In the presence of DON, Cy3-aptamers bind to DON specifically and dissociate from the composite material, and the Raman signal decreases. The prepared SERS aptasensor was capable of detecting DON in a wide range from 0.01 to 10,000 ng/mL with a detection limit of 4.56 pg/mL, and the recovery rate of 94.42–107.04 % was obtained in two real samples, which indicated that the aptasensor proposed in this study exhibited outstanding practical performance and had potential application value in the field of food safety.

Prediction of Deoxynivalenol Contamination in Wheat via Infrared Attenuated Total Reflection Spectroscopy and Multivariate Data Analysis.

The climate crisis further exacerbates the challenges for food production. For instance, the increasingly unpredictable growth of fungal species in the field can lead to an unprecedented high prevalence of several mycotoxins, including the most important toxic secondary metabolite produced by Fusarium spp., i.e., deoxynivalenol (DON). The presence of DON in crops may cause health problems in the population and livestock. Hence, there is a demand for advanced strategies facilitating the detection of DON contamination in cereal-based products. To address this need, we introduce infrared attenuated total reflection (IR-ATR) spectroscopy combined with advanced data modeling routines and optimized sample preparation protocols. In this study, we address the limited exploration of wheat commodities to date via IR-ATR spectroscopy. The focus of this study was optimizing the extraction protocol for wheat by testing various solvents aligned with a greener and more sustainable analytical approach. The employed chemometric method, i.e., sparse partial least-squares discriminant analysis, not only facilitated establishing robust classification models capable of discriminating between high vs low DON-contaminated samples adhering to the EU regulatory limit of 1250 μg/kg but also provided valuable insights into the relevant parameters shaping these models.

Assessing the Effect of Flour (White or Whole-Grain) and Process (Direct or Par-Baked) on the Mycotoxin Content of Bread in Spain.

Bread is the staple food in many parts of the world. Like other foods, bread can contain mycotoxins resulting from microbial development throughout the supply chain (from field to table). In this study, baguette-style bread from small artisanal bakeries (direct) and supermarkets (par-baked loaves made by large companies) in Castile and Leon (Spain) was analyzed. Both white and whole-grain breads were collected from all retail outlets. The mycotoxins analyzed included deoxynivalenol (DON), ochratoxin (OTA), and aflatoxin B1 and B2 (AFB1, AFB2). All of the bread samples studied had mycotoxin levels below the maximum limits established by legislation. The presence of DON was higher than that of OTA, and AFB1 and AFB2 could not be quantified. Industrial breads had higher levels of DON and OTA (only in the whole-grain breads) compared to artisanal breads. However, no significant differences were found between white and industrial breads beyond those mentioned above. These results demonstrate that the established control chains ensure low mycotoxin content in bread of this type.

ZIF-8 labelled a new electrochemical aptasensor based on PEI-PrGO/AuNWs for DON detection

In this work, a novel ultrasensitive aptasensor for deoxynivalenol (DON) detection based on the polyethyleneimine-functionalised porous reduced graphene oxide loaded gold nanowires (PEI-PrGO/AuNWs) and methylene blue (MB)-labelled zeolitic imidazolate framework-8 (ZIF-8) signal amplification strategy was proposed. PEI-PrGO/AuNWs with large surface area and excellent conductivity were used as modification materials on bare gold electrodes, which could increase the combining of complementary strand (cDNA) on the electrode substrate and accelerate the electron transfer efficiency. Furthermore, a novel electrochemical signal probe was synthesized using streptavidin-modified zeolitic imidazolate framework-8 (ZIF-8/SA) as a carrier loaded with MB and reverse complementary chain (sDNA). In the presence of DON, the signal probe was introduced to the electrode surface by Watson-Crick base pairing after specific binding of DON to the aptamer (Apt). As expected, under the optimal conditions, the DON concentration was linearly related to the peak current generated by the prepared aptasensor, and the measured data were combined with theoretical calculations to obtain a detection limit of 2.23 × 10−9 mg/mL.

A sensitive electrochemiluminescence resonance energy transfer system between Ru-MOFs and Bi2S3 for deoxynivalenol detection

This study reports the fabrication of a novel “off-on” electrochemiluminescent (ECL) aptsensor based on ECL resonance energy transfer (RET) for the detection of deoxynivalenol (DON) in wheat and corn. Ru-MOF nanosheets (Ru-MOFs) using tris (4,4′-dicarboxylic acid-2,2′-bipyridine) ruthenium(II) as organic ligands exhibited a high ECL intensity. However, in the presence of Bi2S3 nanorods, the ECL intensity of Ru-MOFs was significantly quenched owing to the efficient ECL-RET system. The function of the Ru-MOFs and Bi2S3 nanorods as ECL energy donors and acceptors, respectively, were thoroughly investigated. For the construction of ECL-RET based aptasensor, a complementary sequence (cDNA) was immobilized onto Bi2S3 @AuNPs to improve the binding efficiency on the sulfhydryl-modified aptamer (SH-Apt), thus reducing the distance between the donors and acceptors and triggering ECL-RET. In the presence of DON, the specificity and strong binding of DON to Apt induced a drop in Bi2S3 @AuNPs-cDNA on the Ru-MOFs surface, thus restoring the ECL intensity. Under optimized conditions, the ECL biosensor showed excellent linearity over the concentration range of 0.01–500 μg kg−1 DON and a low detection limit of 9 × 10−3 μg kg−1 (S/N = 3). Consequently, the proposed strategy provides an effective analytical tool for food safety detection and drug analysis.

Quercetin attenuates deoxynivalenol-induced intestinal barrier dysfunction by activation of Nrf2 signaling pathway in IPEC-J2 cells and weaned piglets

The presence of deoxynivalenol (DON), one of the most frequently occurring mycotoxin, in food and feed has been considered a risk factor to both human and animal health. Molecular mechanisms that regulate DON effects in tissues are still poorly understood. However, recent evidence suggests that nuclear factor erythroid 2-like 2 (Nrf2) may be a major target during mycotoxin-induced intestinal barrier dysfunction. Although quercetin, a plant-derived flavonoid, is known to induce the activation of Nrf2 signaling pathway, its potential to mitigate effects of DON and the implication of Nrf2 in its physiological effects is poorly understood. Therefore, this study was conducted to investigate the protective effects of quercetin in alleviating the DON-induced barrier loss and intestinal injuries in IPEC-J2 cells and weaned piglets and determine the potential role of Nrf2. Quercetin treatment dose-dependently increased mRNA expression of Nrf2 target gene, NQO-1, and concomitantly increased the expression of claudin-4 at both mRNA and protein levels. Quercetin supplementation also reversed the reduction of claudin-4 caused by DON exposure in vivo and in vitro. The decreased membrane presence of claudin-4 and ZO-1 induced by DON was also blocked by quercetin. Furthermore, quercetin attenuated the endocytosis and degradation of claudin-4 caused by DON exposure. The effects of quercetin also included the restoration of transepithelial electrical resistance (TEER) and reduction of FITC-dextran permeability that have been perturbed by DON. However, the protective effects of quercetin against DON exposure were abolished by a specific Nrf2 inhibitor (brusatol), confirming the importance of Nrf2 in the regulation of TJP expression and barrier function by quercetin. In vivo study in weaned pigs showed that DON exposure impaired villus-crypt morphology as indicated by diffuse apical villus necrosis, villus atrophy and fusion. Notably, intestinal injuries caused by DON administration were partly mitigated by quercetin supplementation. Collectively, this study shows that quercetin could be used to prevent the DON-induced gut barrier dysfunction in humans and animals and the protective effects of quercetin against DON-induced intestinal barrier disruption is partly through Nrf2-dependent signaling pathway.

ПАТОМОРФОЛОГИЧЕСКИЕ ИЗМЕНЕНИЯ У ПОРОСЯТ ПРИ ТРИХОТЕЦЕНОВОМ МИКОТОКСИКОЗЕ

The aim of the study was to identify pathomorphological changes in combined deoxynivalenol and T-2 toxicosis in piglets of the rearing group. The material of the study was 19 weaned piglets aged 52‒63 days, in which mycotoxicosis was suspected during their lifetime. The material for the study also served as 10 samples of full-grain granular compound feed SK-4 for piglets aged 1.5‒2 months, fed in groups of the studied animals. We conducted a pathoanatomic study using the method of complete evisceration according to G.V. Shor. During the autopsy, liver and kidney samples were taken from piglets for histological examination. The pathological material was fixed in a 10% solution of neutral formalin. Then the filling was carried out in paraffin and sections 5‒7 microns thick were made on a rotary microtome. The sections were stained with hematoxylin and eosin. The quantitative content of mycotoxins in feed samples was determined in the laboratory of biochemical analysis of the Federal Scientific Center All-Russian Scientific Research and Technological Institute of Poultry Farming using the method of high-performance chromatography in tandem with mass spectrometry (HPLC-MS/MS). As a result of the study, the content of T-2 toxin in the concentration from 0.03 to 0.89 mg/kg and the presence of deoxynivalenol (DON) toxin in the concentration from 0.5 to 4.9 mg/kg were found in the feed samples, which significantly exceeded the maximum permissible levels of these mycotoxins in pig feed. At the autopsy, hemorrhages, foci of necrosis and erosion in the skin, anemia, foci of necrosis, erosion, hemorrhages, catarrhal inflammation in the stomach, hemorrhages and inflammation in the intestines, pulmonary edema and acute reactive hepatitis were found in piglets. Histological examination of the liver revealed granular and watery dystrophy, necrosis of hepatocytes, leukocyte infiltration of Disse spaces. In the kidneys - watery dystrophy and necrosis of the epithelial cells of the renal tubules.

ZIF-8 base-aptamer "gate-lock" probes enable the visualization of a cascade response between deoxynivalenol and cytochrome c inside living cells.

Zeolitic imidazolate framework (ZIF-8) base-aptamer "gate-lock" biomaterial probes have been synthesizedfor monitoring intracellular deoxynivalenol (DON) and cytochrome c (cyt c) levels. The aptamer and organic fluorescent dye were regarded as a recognition element and a sensing element, respectively. In the presence of DON, the aptamers of DON and cyt c were specifically bound with the DON and induced cyt c, leading to the dissociation of aptamers from the porous surface of the probes. The gate was subsequently opened to release methylene blue (MB) and Rhodamine 6G (Rh6G), and their fluorescence (emission of MB at 700nm and Rh6G at 550nm) significantly recovered within 6h. Cell imaging successfully monitored the exposure of DON and the biological process of cyt c discharge triggered by the activation of the DON-induced apoptosis pathway. In addition, the response between DON and cyt c was observed during the apoptosis process, which is of high significance for the comprehensive and systematic development of mycotoxins cytotoxicity.

Selenomethionine Alleviates DON-Induced Oxidative Stress via Modulating Keap1/Nrf2 Signaling in the Small Intestinal Epithelium.

The small intestinal epithelium is regulated in response to various beneficial or harmful environmental information. Deoxynivalenol (DON), a mycotoxin widely distributed in cereal-based feeds, induces oxidative stress damage in the intestine due to the mitochondrial stress. As a functional nutrient, selenomethionine (Se-Met) is involved in synthesizing several antioxidant enzymes, yet whether it can replenish the intestinal epithelium upon DON exposure remains unknown. Therefore, the in vivo model C57BL/6 mice and the in vitro model MODE-K cells were treated with l-Se-Met and DON alone or in combination to confirm the status of intestinal stem cell (ISC)-driven epithelial regeneration. The results showed that 0.1 mg/kg body weight (BW) Se-Met reinstated the growth performance and integrity of jejunal structure and barrier function in DON-challenged mice. Moreover, Lgr5+ ISCs and PCNA+ mitotic cells in crypts were prominently increased by Se-Met in the presence of DON, concomitant with a significant increase in absorptive cells, goblet cells, and Paneth cells. Simultaneously, crypt-derived jejunal organoids from the Se-Met + DON group exhibited more significant growth advantages ex vivo. Furthermore, Se-Met-stimulated Keap1/Nrf2-dependent antioxidant system (T-AOC and GSH-Px) to inhibit the accumulation of ROS and MDA in the jejunum and serum. Moreover, Se-Met failed to rescue the DON-triggered impairment of cell antioxidant function after Nrf2 perturbation using its specific inhibitor ML385 in MODE-K cells. In conclusion, Se-Met protects ISC-driven intestinal epithelial integrity against DON-induced oxidative stress damage by modulating Keap1/Nrf2 signaling.

An electrochemical immunosensor based on prussian blue@zeolitic imidazolate framework-8 nanocomposites probe for the detection of deoxynivalenol in grain products

The presence of deoxynivalenol (DON) in grains poses a threat to human health, which is critical for sensitive detection of DON. In this electrochemical immunosensor, zeolitic imidazolate framework-8 (ZIF-8) loaded with Prussian blue (PB) nanoparticles was coated by polydopamine (PDA) as a redox probe. The high porosity of ZIF-8, the unique electrochemical activity of PB and the outstanding electrical conductivity of PDA improved the sensitivity of the immunosensor. Under the optimized conditions, the peak current in differential pulse voltammetry displayed a good linear relationship over DON concentrations in a range of 0.1–5000 pg mL−1 with a detection limit of 0.0186 pg mL−1. In addition, the immunosensor also had good selectivity and stability. Good recoveries of 85.67 to 118.00 % have been achieved for the detection of DON in spiked grain products. This new strategy exhibits great potential for simple and rapid detection of DON in grain and feed products.

Does Deoxynivalenol Affect Amoxicillin and Doxycycline Absorption in the Gastrointestinal Tract? Ex Vivo Study on Swine Jejunum Mucosa Explants.

The presence of deoxynivalenol (DON) in feed may increase intestinal barrier permeability. Disturbance of the intestinal barrier integrity may affect the absorption of antibiotics used in animals. Since the bioavailability of orally administered antibiotics significantly affects their efficacy and safety, it was decided to evaluate how DON influences the absorption of the most commonly used antibiotics in pigs, i.e., amoxicillin (AMX) and doxycycline (DOX). The studies were conducted using jejunal explants from adult pigs. Explants were incubated in Ussing chambers, in which a buffer containing DON (30 µg/mL), AMX (50 µg/mL), DOX (30 µg/mL), a combination of AMX + DON, or a combination of DOX + DON was used. Changes in transepithelial electrical resistance (TEER), the flux of transcellular and intracellular transport markers, and the flux of antibiotics across explants were measured. DON increased the permeability of small intestine explants, expressed by a reduction in TEER and an intensification of transcellular marker transport. DON did not affect AMX transport, but it accelerated DOX transport by approximately five times. The results suggest that DON inhibits the efflux transport of DOX to the intestinal lumen, and thus significantly changes its absorption from the gastrointestinal tract.

Comparison of Antifungal Activity of Bacillus Strains against Fusarium graminearum In Vitro and In Planta

Fusarium graminearum (Fg) causes Fusarium head blight (FHB) disease in wheat and barley. This pathogen produces mycotoxins including deoxynivalenol (DON), the T-2 and fumorisin B1. Translocation of the mycotoxins in grains causes important losses in yields and contributes to serious health problems in humans and livestock. We tested the Bacillus strains, two commercial, QST713 (Serenade®) and FZB24 (TAEGRO®) and one non-commercial strain EU07 as microbial biological control agents against the F. graminearum strain Fg-K1-4 both in vitro and in planta. The EU07 strain showed better performance in suppressing the growth of Fg-K1-4. Cell-free bacterial cultures displayed significant antagonistic activity on Fg-K1-4. Remarkably, heat and proteinase K treatment of bacterial broths did not reduce the antagonistic activity of Bacillus cultures. DON assays showed that Bacillus strain was not affected by the presence of DON in the media. Leaf and head infection assays using Brachypodium distachyon (Bd-21) indicated that EU07 inhibits Fg-K1-4 growth in vivo and promotes plant growth. Overall, the EU07 strain performed better, indicating that it could be explored for the molecular investigations and protection of cereal crops against FHB disease.

Deoxynivalenol contamination in cereal-based foodstuffs from Spain: Systematic review and meta-analysis approach for exposure assessment

The presence of deoxynivalenol (DON) has been repeatedly detected in cereal-based products collected from Spanish markets over the last years. Hence, the aim of this study was to conduct a systematic review and meta-analysis of the concentration and prevalence of DON in cereals and cereal-based products from Spanish markets intended for human consumption, in order to integrate the available data. Then, an exposure assessment was performed based on national consumption data. Results revealed a strong impact of DON in breakfast cereals (pooled concentration = 105.34 ng/g; pooled prevalence = 58%) and bread and derived products (pooled concentration = 95.17 ng/g; pooled prevalence = 67%). Meta-regression showed a decrease in DON prevalence ( p -value = 0.761) and concentration ( p -value = 0.027) over the last 15 years. Exposure assessment outlined a high exposure to DON, especially in infants and children below 3 years old that showed a 175% and 119% of the tolerable daily intake (TDI). Bread and derived products were the main contributor to DON throughout age groups, with %TDI values ranging from 12% to 34%. Therefore, the here-presented results provide more evidence about the non-negligible impact of DON in Spain as result of cereal-based products consumption. • First meta-analysis of DON contamination in cereal products from Spain. • Significant decrease of DON concentration in cereal products over time. • Non-significant decrease of DON prevalence in cereal products over time. • Bread and derived products were the main contributors to DON exposure. • Exposure to DON in population below 3 years old exceeded the TDI.

Natural Occurrence of Deoxynivalenol in Cereal-Based Baby Foods for Infants from Western Poland.

The study examined 110 samples of baby products based on rice, wheat, maize and multi-grains available on the western Polish market in order to detect the level of deoxynivalenol (DON) by means of HPLC (high-performance liquid chromatography) with a fluorescence detector (HPLC-FLD). DON was detected in 9.09% of the infant food samples, with an average and maximum level of 107.8 ± 30 and 148 μg/kg, respectively. The highest concentration of DON was detected in food for infants: wheat-based (mean 121 ± 7.07, 4.8%), multi-grain (mean 118 ± 5.65, 4.25%) and maize-based (mean 100 ± 37.96; 35.30%). No high DON content and high estimated daily intake were observed in the analyzed products. However, in order to minimize the harmfulness associated with the presence of DON in food for infants and young children, a risk assessment should be performed based on the monitoring results.

Mycotoxin deoxynivalenol affects myoblast differentiation via downregulating cytoskeleton and ECM-integrin-FAK-RAC-PAK signaling pathway

As a common mycotoxin, deoxynivalenol (DON) contaminates cereal grains and feed in field or during processing and storage. DON elicits a spectrum of adverse effects in animals including anorexia and growth retardation. Especially, the presence of DON has also been detected in muscle, suggesting that DON may has the potential to affect the development of muscle. However, the relevant research is very rare and the molecular mechanism remains unclear. Myoblasts differentiation into multinucleated myotubes is one of the crucial steps of skeletal muscle development. In the present study, we investigated the effects of DON on differentiation of myoblasts using murine C2C12 cells model. The results indicated that DON dose-dependent inhibited the formation of myotubes in C2C12 cells. After performing omics techniques, a total of 149 differentially expressed genes were identified. The expression of cytoskeleton proteins and extracellular matrix (ECM) proteins were downregulated by DON. Furthermore, DON significantly downregulated the expression of integrin αv and integrin β5, leading to inhibition of the ECM-integrin receptor interaction. The focal adhesion kinase (FAK) and phosphorylated forms, ras-related C3 botulinum toxin substrate (RAC) and p21-activated kinases 1 (PAK1) were also downregulated by DON. Taken together, our findings suggest that DON has the potent to affect the differentiation of myoblasts via downregulating of cytoskeleton and ECM-integrin-FAK-RAC-PAK signaling pathway.

Tracking Zearalenone and Type-B Trichothecene Mycotoxins in the Commercial Production of Beer and Brewers’ Spent Grains

The contamination of brewers’ spent grains (BSG) with mycotoxins may pose a significant threat to the health of domestic animals that consume BSG as feed. New information is needed regarding the presence of mycotoxins throughout commercial beer and BSG production. Samples (n = 106) were collected during production of a single batch of commercial beer, including malt (n = 54), mash (n = 6), wort (n = 6), fermentation, (n = 14), beer (n = 3), and BSG (n = 23) and analyzed for the presence of deoxynivalenol (DON), 3-acetyldeoxnivalenol (3ADON), 15-acetyldeoxynivalenol (15ADON), and zearalenone (ZEN) using gas chromatography–mass spectrometry (GC-MS). DON, 3ADON, 15ADON, and ZEN were observed at low levels (<0.05 mg kg−1) throughout the production of the beer. Despite most of the samples having low levels of mycotoxins, qualitative analyses showed trace levels of DON, 15ADON, and ZEN in barley malt, solid-fractions of mash, and BSG. Overall, results from this study suggest that low-levels of mycotoxins are retained in BSG, which may consumed by livestock. Results may help brewers and animal producers to consider storage and feeding procedures for BSG.

A highly-sensitive and selective antibody-like sensor based on molecularly imprinted poly(L-arginine) on COOH-MWCNTs for electrochemical recognition and detection of deoxynivalenol

A new strategy to mimic antibody for electrochemical recognition and detection of deoxynivalenol (DON) using a highly-sensitive and selective antibody-like sensor based on molecularly imprinted poly(l-arginine) (P-Arg-MIP) on carboxylic acid functionalized carbon nanotubes (COOH-MWCNTs) was proposed. l-arginine as functional monomer was screened to prepare imprinted electrode via its electro-polymerization in the presence of DON onto the surface of COOH-MWCNTs electrode coupled with theoretical calculation. Surface morphology, structural characteristics, and electrochemical properties of P-Arg-MIP/COOH-MWCNTs were characterized by SEM, EDS, FTIR, and CV, respectively. P-Arg-MIP/COOH-MWCNTs displayed relatively high conductivity, high effective surface area, antibody-like molecular recognition and affinity, and a good response towards DON in a linear range from 0.1 to 70 μM with LOD of 0.07 μM in wheat flour samples with satisfactory recovery and feasible practicability in comparison with HPLC. This method provides a promising biomimetic sensing platform for the determination of mycotoxins in food and agro-products.

Fate of deoxynivalenol (DON) and impact on the soil microflora and soil fauna

Fusarium graminearum is a plant-pathogenic fungus that causes the devastating disease “Fusarium head blight” (FHB) in cereal crops such as wheat (Triticum aestivum). It also contaminates grains with mycotoxins, including deoxynivalenol (DON), which turn toxic to humans and animals. This fungus overwinters in crop residues left in the field. The fate of mycotoxins in these crop residues in the soil and their ecological role are still unexplored. Therefore, our objective was to assess whether mycotoxins are maintained in the soil, impact the soil biome and benefit the survival of F. graminearum. A six-month study in microcosms was performed to examine the fate of DON in F. graminearum-contaminated wheat straw and soil, and its impact on soil communities. DON was extracted from straw and soil mixtures, and quantified by high-performance liquid chromatography (HPLC). Fusarium graminearum and total fungal and bacterial molecular biomasses were quantified using real-time polymerase chain reaction (Q-PCR). Nematode and earthworm densities were quantified through binocular observations. Changes in the genetic structure of fungi, bacteria, protozoa, and nematodes communities were determined by terminal restriction fragment length polymorphism (T-RFLP) analyses. Results revealed that DON disappeared from the straw and the soil over time. The rate of disappearance was accelerated when straw was incorporated into the soil and when microcosms contained earthworms. Fungal and bacterial biomass, first stimulated during the incorporation of straw, decreased after 2 weeks and until the end of the experiment (24 weeks). It decreased more strongly in the presence of DON. This negative impact of DON was temporary and at the end of the experiment, the bacterial and fungal biomass was higher in the treatments that received DON than in the other treatments while the population of F. graminearum was unaffected. Similarly, DON modified the community structures of fungi, bacteria and protozoa to various extents but not that of nematodes. DON-contaminated straw was found attractive for earthworms, and its presence stimulated their reproduction or cocoon hatching. The major conclusion is that DON briefly affected soil communities, disappeared over time and gave no observable advantage to soil-borne F. graminearum populations.

Effects of Deoxynivalenol-Contaminated Diets on Metabolic and Immunological Parameters in Broiler Chickens.

Simple SummaryMycotoxin contamination in feed is a significant problem worldwide because these toxic metabolites can have serious adverse effects on animals, resulting great economic loss. Deoxynivalenol (DON) is the most commonly detected mycotoxin in cereals and therefore in poultry feed. This mycotoxin could adversely affect the health of birds. In this work, broiler chickens were exposed to two different levels of DON (5 and 15 mg/kg feed) for 42 days. The results revealed that broilers fed the high level (15 mg/kg) had DON-3-sulphate (a specific metabolite of DON) deposited in the liver and had reduced blood hematological parameters. The ingestion of the guidance level (5 mg DON/kg fee) affected the immune system parameters in broiler chickens. Both levels did not adversely affect the broiler’s welfare related-parameters.The current study was conducted to examine the effects of deoxynivalenol (DON) at different levels (5 and 15 mg/kg feed) on the metabolism, immune response and welfare parameters of male broiler chickens (Ross 308) at 42 days old. Forty-five 1 day-old broiler chickens were randomly distributed into three different dietary treatments: (1) control, (2) DON-contaminated diet with 5 mg DON/kg of feed (guidance level), and (3) DON-contaminated diet with 15 mg DON/kg of feed. Five replicated cages with three birds each were used for each treatment in a randomized complete block design. The results showed that DON was detected in excreta of birds fed contaminated diets compared with controls. The metabolite DON-3 sulphate (DON-3S) was detected in plasma and excreta in both treated groups, as well as in the liver (but only at 15 mg/kg feed). The increase in the level of DON decreased the hemoglobin concentration (p < 0.001), whereas the erythrocyte counts were only decreased at 15 mg DON/kg feed. No effect of DON on the responses to common vaccines was observed. In plasma, interleukin 8 levels in both contaminated groups were significantly higher than in the control group. The expression of interleukin 6, interleukin 1β and interferon-γ increased in jejunum tissues of broilers fed 5 mg/kg of DON compared with controls. The stress index (heterophil to lymphocyte ratio) was not affected by DON-contaminated diets compared with controls. The plasma corticosterone level was significantly lower in both DON groups compared with controls. In conclusion, DON-3S could be used as a specific biomarker of DON in different biological matrices, while the immune response in broiler chickens is stimulated by the presence of DON at the guidance level, but no adverse effect was observed on physiological stress parameters.