Co-Occurrence of Regulated, Masked and Emerging Mycotoxins and Secondary Metabolites in Finished Feed and Maize-An Extensive Survey

In vitro and in vivo evaluation of AFB1 and OTA-toxicity through immunofluorescence and flow cytometry techniques: A systematic review

Due to the globalization, mycotoxins have been considered a major risk to human health being the main contaminants of foodstuffs. Among them, AFB1 and OTA are the most toxic and studied. Therefore, the goal of this review is to deepen the knowledge about the toxicological effects that AFB1 and OTA can induce on human health by using flow cytometry and immunofluorescence techniques in vitro and in vivo models. The examination of the selected reports shows that the majority of them are focused on immunotoxicity while the rest are concerned about nephrotoxicity, hepatotoxicity, gastrointestinal toxicity, neurotoxicity, embryotoxicity, reproductive system, breast, esophageal and lung toxicity. In relation to immunofluorescence analysis, biological processes related to AFB1- and OTA-toxicity were evaluated such as inflammation, neuronal differentiation, DNA damage, oxidative stress and cell death. In flow cytometry analysis, a wide range of assays have been performed across the reviewed studies being apoptosis assay, cell cycle analysis and intracellular ROS measurement the most employed. Although, the toxic effects of AFB1 and OTA have been reported, further research is needed to clarify AFB1 and OTA-mechanism of action on human health.

Evaluation of a Yeast Hydrolysate from a Novel Strain of Saccharomyces cerevisiae for Mycotoxin Mitigation using In Vitro and In Vivo Models

Mycotoxicoses in animals are caused by exposure to mycotoxin-contaminated feeds. Disease risk is managed using dietary adsorbing agents which reduce oral bioavailability. The objective of this work was to evaluate the efficacy of three selected yeast products as mycotoxin binders using in vitro and in vivo models. Their capacity to adsorb deoxynivalenol (DON), zearalenone (ZEA), and ochratoxin A (OTA) was evaluated using an in vitro model designed to simulate the pH conditions during gastric passage in a monogastric animal. Results showed that only one product, an enzymatic yeast hydrolysate (YHY) of a novel strain Saccharomyces cerevisiae, adsorbed about 45% of DON in solution. Next, we determined the effect of YHY on oral absorption of a DON, ZEA, and OTA mixture using a toxicokinetic model in swine. Toxicokinetic modeling of the plasma concentration-time profiles of DON, OTA, and zearalenone-glucuronide (ZEA-GlcA) showed that YHY tended to reduce the maximal plasma concentration of OTA by 17%. YHY did not reduce oral bioavailability of OTA, DON, and ZEA-GlcA. Within the context of this experiment, and despite some positive indications from both the in vitro and in vivo models employed, we conclude that the YHY prototype was not an effective agent for multiple mycotoxin adsorption.

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.

Zearalenone Exposure Disrupts Blood-Testis Barrier Integrity through Excessive Ca2+-Mediated Autophagy

Zearalenone (ZEA), a common mycotoxin in grains and animal feeds, has been associated with male reproductive disorders. However, the potential toxicity mechanism of ZEA is not fully understood. In this study, in vivo and in vitro models were used to explore the effects of ZEA on the blood-testis barrier (BTB) and related molecular mechanisms. First, male BALB/C mice were administered ZEA orally (40 mg/kg·bw) for 5-7 d. Sperm motility, testicular morphology, and expressions of BTB junction proteins and autophagy-related proteins were evaluated. In addition, TM4 cells (mouse Sertoli cells line) were used to delineate the molecular mechanisms that mediate the effects of ZEA on BTB. Our results demonstrated that ZEA exposure induced severe testicular damage in histomorphology and an ultrastructural, time-dependent decrease in the expression of blood-testis barrier junction-related proteins, accompanied by an increase in the expression of autophagy-related proteins. Additionally, similar to the in vitro results, the dose-dependent treatment of ZEA increased the level of cytoplasmic Ca²⁺ and the levels of the autophagy markers LC3-II and p62, in conjunction with a decrease in the BTB junction proteins occludin, claudin-11, and Cx43, with the dislocation of the gap junction protein Cx43. Meanwhile, inhibition of autophagy by CQ and 3-MA or inhibition of cytoplasmic Ca²⁺ by BAPTA-AM was sufficient to reduce the effects of ZEA on the TM4 cell BTB. To summarize, this study emphasizes the role of Ca²⁺-mediated autophagy in ZEA-induced BTB destruction, which deepens our understanding of the molecular mechanism of ZEA-induced male reproductive disorders.

Isoflavones in Animals: Metabolism and Effects in Livestock and Occurrence in Feed

Soybeans are a common ingredient of animal feed. They contain isoflavones, which are known to act as phytoestrogens in animals. Isoflavones were described to have beneficial effects on farm animals. However, there are also reports of negative outcomes after the consumption of isoflavones. This review summarizes the current knowledge of metabolization of isoflavones (including the influence of the microbiome, phase I and phase II metabolism), as well as the distribution of isoflavones and their metabolites in tissues. Furthermore, published studies on effects of isoflavones in livestock species (pigs, poultry, ruminants, fish) are reviewed. Moreover, published studies on occurrence of isoflavones in feed materials and co-occurrence with zearalenone are presented and are supplemented with our own survey data.

Mycotoxins—Prevention, Detection, Impact on Animal Health

Mycotoxins are defined as secondary metabolites of some species of mold fungi. They are present in many foods consumed by animals. Moreover, they most often contaminate products of plant and animal origin. Fungi of genera Fusarium, Aspergillus, and Penicillum are most often responsible for the production of mycotoxins. They release toxic compounds that, when properly accumulated, can affect many aspects of breeding, such as reproduction and immunity, as well as the overall liver detoxification performance of animals. Mycotoxins, which are chemical compounds, are extremely difficult to remove due to their natural resistance to mechanical, thermal, and chemical factors. Modern methods of analysis allow the detection of the presence of mycotoxins and determine the level of contamination with them, both in raw materials and in foods. Various food processes that can affect mycotoxins include cleaning, grinding, brewing, cooking, baking, frying, flaking, and extrusion. Most feeding processes have a variable effect on mycotoxins, with those that use high temperatures having the greatest influence. Unfortunately, all these processes significantly reduce mycotoxin amounts, but they do not completely eliminate them. This article presents the risks associated with the presence of mycotoxins in foods and the methods of their detection and prevention.

Enniatin B and Deoxynivalenol Activity on Bread Wheat and on Fusarium Species Development

Fusarium head blight (FHB) is a devastating wheat disease, mainly caused by Fusarium graminearum (FG)-a deoxynivalenol (DON)-producing species. However, Fusarium avenaceum (FA), able to biosynthesize enniatins (ENNs), has recently increased its relevance worldwide, often in co-occurrence with FG. While DON is a well-known mycotoxin, ENN activity, also in association with DON, is poorly understood. This study aims to explore enniatin B (ENB) activity, alone or combined with DON, on bread wheat and on Fusarium development. Pure ENB, DON, and ENB+DON (10 mg kg-1) were used to assess the impacts on seed germination, seedling growth, cell death induction (trypan blue staining), chlorophyll content, and oxidative stress induction (malondialdehyde quantification). The effect on FG and FA growth was tested using ENB, DON, and ENB+DON (10, 50, and 100 mg kg-1). Synergistic activity in the reduction of seed germination, growth, and chlorophyll degradation was observed. Conversely, antagonistic interaction in cell death and oxidative stress induction was found, with DON counteracting cellular stress produced by ENB. Fusarium species responded to mycotoxins in opposite directions. ENB inhibited FG development, while DON promoted FA growth. These results highlight the potential role of ENB in cell death control, as well as in fungal competition.

The administration of diets contaminated with low to intermediate doses of deoxynivalenol and supplemented with antioxidants and binding agents slightly affects the growth, antioxidant status, and vaccine response in weanling pigs

This study aimed to evaluate the impact of grading levels of deoxynivalenol (DON) in the diet of weaned pigs, as well as the effects of a supplementation with antioxidants (AOX), hydrated sodium calcium aluminosilicates (HSCAS), and their combination on the growth, AOX status, and immune and vaccine responses against the porcine reproductive and respiratory syndrome virus (PRRSV) and porcine circovirus type 2 (PCV2). At weaning, 336 piglets were allocated to six dietary treatments according to a randomized complete block design. Treatments were as follows: basal diet (CTRL); basal diet containing DON at 1.2 mg/kg (DON1.2); basal diet containing DON at 2.4 mg/kg (DON2.4); DON2.4 diet + a mix of AOX which included vitamins A and E at 20,000 IU and 200 IU/kg feed respectively, selenized yeast at 0.3 mg/kg, and a grape seed extracts at 100 mg/kg feed (DON2.4 + AOX); DON2.4 diet + the mix of AOX and the modified HSCAS mentioned above (DON2.4 + AOX + HSCAS); DON2.4 + AOX + HSCAS. Pigs were vaccinated against PRRSV and PCV2 at 7 d; on 0, 14, and 35 d, growth performance was recorded, and blood samples were collected in order to evaluate the oxidative status, inflammatory blood markers, lymphocyte blastogenic response, and vaccine antibody response. Increasing intake of DON resulted in a quadratic effect at 35 d in the lymphocyte proliferative response to concanavalin A and PCV2 as well as in the anti-PRRSV antibody response, whereas the catalase activity decreased in DON2.4 pigs compared with the CTRL and DON1.2 groups (P ≤ 0.05). Compared with the DON2.4 diet, the AOX supplementation slightly reduced gain to feed ratio (P = 0.026) and increased the ferric reducing ability of plasma as well as α-tocopherol concentration (P < 0.05), whereas the association of AOX + HSCAS increased the anti-PRRSV IgG (P < 0.05). Furthermore, the HSCAS supplement reduced haptoglobin levels in serum at 14 d compared with the DON2.4 group; however, its concentration decreased in all the experimental treatments from 14 to 35 d and particularly in the DON2.4 + AOX pigs, whereas a different trend was evidenced in the DON2.4 + HSCAS group, where over the same period haptoglobin concentration increased (P < 0.05). Overall, our results show that the addition of AOX and HSCAS in the diet may alleviate the negative effects due to DON contamination on the AOX status and immune response of vaccinated weanling pigs.

Determination of principal ergot alkaloids in swine feeding

BACKGROUND

Ergot alkaloids are secondary metabolites produced by fungi in the genus Claviceps. They contaminate a large variety of cereals, such as rye, triticale, wheat and barley. The ingestion of contaminated cereals might cause adverse health effects in humans and animals. In fact, pigs, cattle, sheep, and poultry are involved in sporadic outbreaks and, although there are several studies about occurrence of ergot alkaloids in grain cereals, there are scarce studies focused on compound feed.

RESULTS

Twelve ergot alkaloids have been quantified in 228 feed samples intended for swine. The analytes were extracted using QuEChERS with Z-Sep+ as sorbent in the clean-up step, which reduced the matrix effect, allowing limits of quantification between 2.1 and 21.7 μg kg^-1 . The analytes were subsequently quantified by ultra-high-performance liquid chromatography with tandem mass spectrometry (UHPLC-MS/MS). A total of 29 samples (12.7%) revealed contamination by at least one ergot alkaloid, and among contaminated samples, 65% were contaminated by more than one. Only 6 of 12 target ergot alkaloids showed concentrations above the limit of quantification. The concentrations for individual ergot alkaloids ranged between 5.9 μg kg^-1 for ergosinine to 145.3 μg kg^-1 for ergometrine (the predominant ergot alkaloid), while the total ergot alkaloid content ranged from 5.9 to 158.7 μg kg^-1 .

CONCLUSIONS

The occurrence of ergot alkaloids in feed samples in Spain seems to be lower than in other regions of Europe. All the samples fulfilled current recommendations of the feed industry about practical limits for ergot alkaloids in pig feeds. This suggests that the feeds are safe for pig consumption, regarding the presence of ergot alkaloids. © 2021 Society of Chemical Industry.

Mycotoxin Biomarkers in Pigs-Current State of Knowledge and Analytics

Farm animals are frequently exposed to mycotoxins, which have many adverse effects on their health and become a significant food safety issue. Pigs are highly exposed and particularly susceptible to mycotoxins, which can cause many adverse effects. For the above reasons, an appropriate diagnostic tool is needed to monitor pig' exposure to mycotoxins. The most popular tool is feed analysis, which has some disadvantages, e.g., it does not include individual exposure. In recent years, the determination of biomarkers as a method to assess the exposure to mycotoxins by using concentrations of the parent compounds and/or metabolites in biological matrices is becoming more and more popular. This review provides a comprehensive overview of reported in vivo mycotoxin absorption, distribution, metabolism and excretion (ADME) and toxicokinetic studies on pigs. Biomarkers of exposure for aflatoxins, deoxynivalenol, ochratoxin A, fumonisins, T-2 toxin and zearalenone are described to select the most promising compound for analysis of porcine plasma, urine and faeces. Biomarkers occur in biological matrices at trace levels, so a very sensitive technique-tandem mass spectrometry-is commonly used for multiple biomarkers quantification. However, the sample preparation for multi-mycotoxin methods remains a challenge. Therefore, a summary of different biological samples preparation strategies is included in that paper.

Integrated Mycotoxin Management System in the Feed Supply Chain: Innovative Approaches

Exposure to mycotoxins is a worldwide concern as their occurrence is unavoidable and varies among geographical regions. Mycotoxins can affect the performance and quality of livestock production and act as carriers putting human health at risk. Feed can be contaminated by various fungal species, and mycotoxins co-occurrence, and modified and emerging mycotoxins are at the centre of modern mycotoxin research. Preventing mould and mycotoxin contamination is almost impossible; it is necessary for producers to implement a comprehensive mycotoxin management program to moderate these risks along the animal feed supply chain in an HACCP perspective. The objective of this paper is to suggest an innovative integrated system for handling mycotoxins in the feed chain, with an emphasis on novel strategies for mycotoxin control. Specific and selected technologies, such as nanotechnologies, and management protocols are reported as promising and sustainable options for implementing mycotoxins control, prevention, and management. Further research should be concentrated on methods to determine multi-contaminated samples, and emerging and modified mycotoxins.

The Occurrence of Mycotoxins in Raw Materials and Fish Feeds in Europe and the Potential Effects of Deoxynivalenol (DON) on the Health and Growth of Farmed Fish Species-A Review

The first part of this study evaluates the occurrence of mycotoxin patterns in feedstuffs and fish feeds. Results were extrapolated from a large data pool derived from wheat (n = 857), corn (n = 725), soybean meal (n = 139) and fish feed (n = 44) samples in European countries and based on sample analyses by liquid chromatography/tandem mass spectrometry (LC-MS/MS) in the period between 2012-2019. Deoxynivalenol (DON) was readily present in corn (in 47% of the samples) > wheat (41%) > soybean meal (11%), and in aquafeeds (48%). Co-occurrence of mycotoxins was frequently observed in feedstuffs and aquafeed samples. For example, in corn, multi-mycotoxin occurrence was investigated by Spearman's correlations and odd ratios, and both showed co-occurrence of DON with its acetylated forms (3-AcDON, 15-AcDON) as well as with zearalenone (ZEN). The second part of this study summarizes the existing knowledge on the effects of DON on farmed fish species and evaluates the risk of DON exposure in fish, based on data from in vivo studies. A meta-analytical approach aimed to estimate to which extent DON affects feed intake and growth performance in fish. Corn was identified as the ingredient with the highest risk of contamination with DON and its acetylated forms, which often cannot be detected by commonly used rapid detection methods in feed mills. Periodical state-of-the-art mycotoxin analyses are essential to detect the full spectrum of mycotoxins in fish feeds aimed to prevent detrimental effects on farmed fish and subsequent economic losses for fish farmers. Because levels below the stated regulatory limits can reduce feed intake and growth performance, our results show that the risk of DON contamination is underestimated in the aquaculture industry.

Changes in the Intestinal Histomorphometry, the Expression of Intestinal Tight Junction Proteins, and the Bone Structure and Liver of Pre-Laying Hens Following Oral Administration of Fumonisins for 21 Days

Fumonisins (FB) are metabolites found in cereal grains (including maize), crop products, and pelleted feed. There is a dearth of information concerning the effects of FB intoxication on the intestinal histomorphometry, the expression of intestinal tight junction proteins, and the bone structure and liver in pre-laying hens. The current experiment was carried out on hens from the 11th to the 14th week of age. The hens were orally administered an extract containing fumonisin B1 (FB1) and fumonisin B2 (FB2) at doses of 0.0 mg/kg b.w. (body weight), 1.0 mg/kg b.w., 4.0 mg/kg b.w., and 10.9 mg/kg b.w. for 21 days. Following FB intoxication, the epithelial integrity of the duodenum and jejunum was disrupted, and dose-dependent degenerative changes were observed in liver. An increased content of immature collagen was observed in the bone tissue of FB-intoxicated birds, indicating intensified bone turnover. A similar effect was observed with regards to the articular cartilage, where enhanced fibrillogenesis was observed mainly in the group of birds that received the FB extract at a dose of 10.9 mg/kg b.w. In conclusion, FB intoxication resulted in negative structural changes in the bone tissue of the hens, which could result in worsened bone mechanics and an increase in the risk of bone fractures. Fumonisin administration, even at a dose of 1.0 mg/kg b.w., can lead to degradation of the intestinal barrier and predispose hens to intestinal disturbances later in life.

Versicolorin A enhances the genotoxicity of aflatoxin B1 in human liver cells by inducing the transactivation of the Ah-receptor

Aflatoxins are a group of mycotoxins that have major adverse effects on human health. Aflatoxin B1 (AFB1) is the most important aflatoxin and a potent carcinogen once converted into a DNA-reactive form by cytochrome P450 enzymes (CYP450). AFB1 biosynthesis involves the formation of Versicolorin A (VerA) which shares structural similarities with AFB1 and can be found in contaminated commodities, often co-occurring with AFB1. This study investigated and compared the toxicity of VerA and AFB1, alone or in combination, in HepG2 human liver cells. Our results show that both toxins have similar cytotoxic effects and are genotoxic although, unlike AFB1, the main genotoxic mechanism of VerA does not involve the formation of DNA double-strand breaks. Additionally, we show that VerA activates the aryl hydrocarbon receptor (AhR) and significantly induce the expression of the CYP450-1A1 (CYP1A1) while AFB1 did not induce AhR-dependent CYP1A1 activation. Combination of VerA with AFB1 resulted in enhanced genotoxic effects, suggesting that AhR-activation by VerA influences AFB1 genotoxicity by promoting its bioactivation by CYP450s to a highly DNA-reactive metabolite. Our results emphasize the need for expanding the toxicological knowledge regarding mycotoxin biosynthetic precursors to identify those who may pose, directly or indirectly, a threat to human health.

An up-converting phosphor technology-based lateral flow assay for rapid detection of major mycotoxins in feed: Comparison with enzyme-linked immunosorbent assay and high-performance liquid chromatography-tandem mass spectrometry

Current methods for detection of mycotoxin in feed are time-consuming and tedious. An up-converting phosphor technology-based lateral flow (UPT-LF) assay system is a new emerging technique for analytes detection. The aim of this study was to compare the performance of UPT-LF, an enzyme-linked immunosorbent assay (ELISA) and high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) for detecting aflatoxin B₁ (AFB₁), zearalenone (ZEN) and deoxynivalenol (DON) in feed. The results showed that the use of UPT-LF for AFB₁, ZEN and DON detection exhibited the following: limits of detection of 3, 50 and 200 μg/kg; average recoveries of 104.39%, 102.94% and 103.65%; and precision of 13.96%, 13.71% and 12.56%; respectively. UPT-LF required 45 min to determine one mycotoxin and 1.5 h to determine three mycotoxins in a sample, which took the shortest time. Besides, there were positive correlations between the UPT-LF, ELISA and HPLC/MS/MS methods. In conclusion, UPT-LF can be used to detect and quantify AFB₁, ZEN and DON in feed samples. Though the sensitivity, accuracy and precision of UPT-LF are inferior to those of HPLC-MS/MS and ELISA, the UPT-LF assay is the most convenient and rapid technique for on-site detection among the three methods.

Multi-Mycotoxin Contamination of Maize Silages in Flanders, Belgium: Monitoring Mycotoxin Levels from Seed to Feed

Maize silage, which in Europe is the main feed for dairy cattle in winter, can be contaminated by mycotoxins. Mycotoxigenic Fusarium spp. originating from field infections may survive in badly sealed silages or re-infect at the cutting edge during feed-out. In this way, mycotoxins produced in the field may persist during the silage process. In addition, typical silage fungi such as Penicillium spp. and Aspergillus spp. survive in silage conditions and produce mycotoxins. In this research, 56 maize silages in Flanders were sampled over the course of three years (2016-2018). The concentration of 22 different mycotoxins was investigated using a multi-mycotoxin liquid chromatography-tandem mass spectrometry (LC-MS/MS) method, and the presence of DNA of three Fusarium spp. (F. graminearum, F. culmorum and F. verticillioides) was analyzed in a selection of these samples using quantitative polymerase chain reaction (qPCR). Every maize silage contained at least two different mycotoxins. Nivalenol (NIV) and deoxynivalenol (DON) were the most prevalent (both in 97.7% of maize silages), followed by ENN B (88.7%). Concentrations often exceeded the EU recommendations for DON and zearalenone (ZEN), especially in 2017 (21.3% and 27.7% of the maize silages, respectively). No correlations were found between fungal DNA and mycotoxin concentrations. Furthermore, by ensiling maize with a known mycotoxin load in a net bag, the mycotoxin contamination could be monitored from seed to feed. Analysis of these net bag samples revealed that the average concentration of all detected mycotoxins decreased after fermentation. We hypothesize that mycotoxins are eluted, degraded, or adsorbed during fermentation, but certain badly preserved silages are prone to additional mycotoxin production during the stable phase due to oxygen ingression, leading to extremely high toxin levels.

Isolation and characterization of a Pseudomonas poae JSU-Y1 with patulin degradation ability and biocontrol potential against Penicillium expansum

Patulin, one of the most common mycotoxins produced primarily by the Penicillium, Aspergillus and Byssochlamys species, is often associated with fruits and fruit-based products. Biodegradation by microbes is an effective method to remove or detoxify mycotoxins. In this study, a bacterial strain with patulin degradation capability was selectively isolated using oxindole, an analogue to patulin, as the sole carbon source, and identified as Pseudomonas poae JSU-Y1 by phylogenetic analysis on the basis of 16S rRNA sequence. This isolated bacterium could inhibit the growth of Penicillium expansum both on plate medium and apple fruit with inhibition ratio of 30.3% and 44.9%, respectively. Up to 87.7% of the initial patulin (2.5 μg/mL) was removed after incubation with Pseudomonas poae JSU-Y1 in liquid medium at 30 °C for 72 h. When challenged with apple juice, 79% of patulin could be degraded by this isolated strain. Additionally, ascladiol was tentatively identified as the patulin degradation intermediate by LC-MS analysis. Taken together, the experiment results indicated that the isolated Pseudomonas poae JSU-Y1 would be a promising bacterial resource to control patulin contamination and toxigenic fungal growth in agricultural products.

Mycotoxins Analysis in Cereals and Related Foodstuffs by Liquid Chromatography-Tandem Mass Spectrometry Techniques

In the entire world, cereals and related foodstuffs are used as an important source of energy, minerals, and vitamins. Nevertheless, their contamination with mycotoxins kept special attention due to harmful effects on human health. The present paper was conducted to evaluate published studies regarding the identification and characterization of mycotoxins in cereals and related foodstuffs by liquid chromatography coupled to (tandem) mass spectrometry (LC-MS/MS) techniques. For sample preparation, published studies based on the development of extraction and clean-up strategies including solid-phase extraction, solid-liquid extraction, and immunoaffinity columns, as well as on methods based on minimum clean-up (quick, easy, cheap, effective, rugged, and safe (QuEChERS)) technology, are examined. LC-MS/MS has become the golden method for the simultaneous multimycotoxin analysis, with different sample preparation approaches, due to the range of different physicochemical properties of these toxic products. Therefore, this new strategy can be an alternative for fast, simple, and accurate determination of multiclass mycotoxins in complex cereal samples.

Co-Occurrence and Levels of Mycotoxins in Fish Feeds in Kenya

This study determined the presence, levels and co-occurrence of mycotoxins in fish feeds in Kenya. Seventy-eight fish feeds and ingredients were sampled from fish farms and fish feed manufacturing plants and analysed for 40 mycotoxins using high-performance liquid chromatography-high resolution mass spectrometry. Twenty-nine (73%) mycotoxins were identified with 76 (97%) samples testing positive for mycotoxins presence. Mycotoxins with the highest prevalences were enniatin B (91%), deoxynivalenol (76%) and fumonisin B1 (54%) while those with the highest maximum levels were sterigmatocystin (<30.5-3517.1 µg/kg); moniliformin (<218.9-2583.4 µg/kg) and ergotamine (<29.3-1895.6 µg/kg). Mycotoxin co-occurrence was observed in 68 (87%) samples. Correlations were observed between the fumonisins; enniatins B and zearalenone and its metabolites. Fish dietary exposure estimates ranged between <0.16 and 43.38 µg/kg body weight per day. This study shows evidence of mycotoxin presence and co-occurrence in fish feeds and feed ingredients in Kenya. Fish exposure to these levels of mycotoxins over a long period of time may lead to adverse health effects due to their possible additive, synergistic or antagonist toxic effects. Measures to reduce fish feed mycotoxin contamination should be taken to avoid mycotoxicosis in fish and subsequently in humans and animals through residues.

Suppression of Trichothecene-Mediated Immune Response by the Fusarium Secondary Metabolite Butenolide in Human Colon Epithelial Cells

Butenolide (BUT, 4-acetamido-4-hydroxy-2-butenoic acid gamma-lactone) is a secondary metabolite produced by several Fusarium species and is co-produced with the major trichothecene mycotoxin deoxynivalenol (DON) on cereal grains throughout the world. BUT has low acute toxicity and only very limited occurrence and exposure data are available. The intestinal epithelium represents the first physiological barrier against food contaminants. We aimed to elucidate the intestinal inflammatory response of the human, non-cancer epithelial HCEC-1CT cells to BUT and to characterize potential combinatory interactions with co-occurring trichothecenes, such as DON and NX-3. Using a reporter gene approach, BUT (≥5 μM, 20 h) was found to decrease lipopolysaccharide (LPS; 10 ng/mL) induced nuclear factor kappa B (NF-κB) activation in a dose-dependent manner, and in combinatory treatments BUT represses trichothecene-induced enhancement of this important inflammatory pathway. Analysis of transcription and secretion levels of NF-κB-dependent, pro-inflammatory cytokines, revealed a significant down-regulation of IL-1β, IL-6, and TNF-α in IL-1β-stimulated (25 ng/mL) HCEC-1CT cells after BUT exposure (10 μM). Trichothecene-induced expression of pro-inflammatory cytokines by the presence of 1 μM DON or NX-3 was substantially suppressed in the presence of 10 μM BUT. The emerging mycotoxin BUT has the ability to suppress NF-κB-induced intestinal inflammatory response mechanisms and to modulate substantially the immune responsiveness of HCEC-1CT cells after trichothecene treatment. Our results suggest that BUT, present in naturally occurring mixtures of Fusarium fungal metabolites, should be increasingly monitored, and the mechanism of inhibition of NF-κB that might affect the pathogenesis or progression of intestinal inflammatory disorders, should be further investigated.

Low Doses of Mycotoxin Mixtures below EU Regulatory Limits Can Negatively Affect the Performance of Broiler Chickens: A Longitudinal Study

Several studies have reported a wide range of severe health effects as well as clinical signs, when livestock animals are exposed to high concentration of mycotoxins. However, little is known regarding health effects of mycotoxins at low levels. Thus, a long-term feeding trial (between May 2017 and December 2019) was used to evaluate the effect of low doses of mycotoxin mixtures on performance of broiler chickens fed a naturally contaminated diet. In total, 18 successive broiler performance trials were carried out during the study period, with approximately 2200 one-day-old Ross-308 chicks used for each trial. Feed samples given to birds were collected at the beginning of each trial and analysed for multi-mycotoxins using a validated LC-MS/MS method. Furthermore, parameters including feed intake, body weight and feed efficiency were recorded on a weekly basis. In total, 24 mycotoxins were detected in samples analysed with deoxynivalenol (DON), zearalenone (ZEN), fumonisins (FBs), apicidin, enniatins (ENNs), emodin and beauvericin (BEV), the most prevalent mycotoxins. Furthermore, significantly higher levels (however below EU guidance values) of DON, ZEN, FBs, BEV, ENNs and diacetoxyscirpenol (DAS) were detected in 6 of the 18 performance trials. A strong positive relationship was observed between broilers feed efficiency and DON (R2 = 0.85), FBs (R2 = 0.53), DAS (R2 = 0.86), ZEN (R2 = 0.92), ENNs (R2 = 0.60) and BEV (R2 = 0.73). Moreover, a three-way interaction regression model revealed that mixtures of ZEN, DON and FBs (p = 0.01, R2 = 0.84) and ZEN, DON and DAS (p = 0.001, R2 = 0.91) had a statistically significant interaction effect on the birds' feed efficiency. As farm animals are often exposed to low doses of mycotoxin mixtures (especially fusarium mycotoxins), a cumulative risk assessment in terms of measuring and mitigating against the economic, welfare and health impacts is needed for this group of compounds.

Zearalenone (ZEN) in Livestock and Poultry: Dose, Toxicokinetics, Toxicity and Estrogenicity

One of the concerns when using grain ingredients in feed formulation for livestock and poultry diets is mycotoxin contamination. Aflatoxin, fumonisin, ochratoxin, trichothecene (deoxynivalenol, T-2 and HT-2) and zearalenone (ZEN) are mycotoxins that have been frequently reported in animal feed. ZEN, which has raised additional concern due to its estrogenic response in animals, is mainly produced by Fusarium graminearum (F. graminearum), F. culmorum, F. cerealis, F. equiseti, F. crookwellense and F. semitectums, and often co-occurs with deoxynivalenol in grains. The commonly elaborated derivatives of ZEN are α-zearalenol, β-zearalenol, zearalanone, α-zearalanol, and β-zearalanol. Other modified and masked forms of ZEN (including the extractable conjugated and non-extractable bound derivatives of ZEN) have also been quantified. In this review, common dose of ZEN in animal feed was summarized. The absorption rate, distribution (“carry-over”), major metabolites, toxicity and estrogenicity of ZEN related to poultry, swine and ruminants are discussed.

Challenges Associated with Byproducts Valorization-Comparison Study of Safety Parameters of Ultrasonicated and Fermented Plant-Based Byproducts

In order to promote the efficient use of byproducts from the production of plant-based beverages, which still contain a large amount of nutritional and functional compounds, microbiological and chemical safety characteristics should be evaluated and, if needed, improved. Many challenges are associated with byproducts valorization, and the most important ones, which should be taken into account at the further steps of valorization, are biological and chemical safety. For safety improving, several technological treatments (biological, physical etc.) can be used. In this study, the influence of low-frequency ultrasonication (US) and fermentation with Lactobacillus casei LUHS210 strain, as physical and biotechnological treatments, on the safety characteristics of the byproducts (BYs) from the processing of rice, soy, almond, coconut, and oat drinks was compared. Ultrasonication, as well as fermentation, effectively improved the microbiological safety of BYs. Ultrasonication and fermentation reduced the concentration of deoxynivalenol, on average, by 24% only in soy BYs. After fermentation, 15-acetyldeoxynivalenol was formed in all samples (<12 µg kg-1), except for soy BYs. The lowest total biogenic amines content was found in fermented rice BYs and ultrasonicated coconut BYs. When comparing untreated and fermented BYs, significant changes in macro- and micro-elements content were found. Ultrasonication at 37 kHz did not significantly influence the concentrations of macro- and micro-elements, while fermentation affected most of the essential micro-elements. Consequently, while ultrasonication and fermentation can enhance the safety of BYs, the specific effects must be taken into account on biogenic amines, mycotoxins, and micro and macro elements.

Development and Validation of a QuEChERS-Based Liquid Chromatography Tandem Mass Spectrometry Multi-Method for the Determination of 38 Native and Modified Mycotoxins in Cereals

Here, a reliable and sensitive method for the determination of 38 (modified) mycotoxins was developed. Using a QuEChERS-based extraction method [acetonitrile/water/formic acid (75:20:5, v/v/v)], followed by two runs of high performance liquid chromatography tandem mass spectrometry with different conditions, relevant mycotoxins in cereals were analyzed. The method was validated according to the performance criteria defined by the European Commission (EC) in Commission Decision no. 657/2002. Limits of quantification ranged from 0.05 to 150 μg/kg. Good linearity (R² > 0.99), recovery (61-120%), repeatability (RSDr < 15%), and reproducibility (RSDR < 20%) were obtained for most mycotoxins. However, validation results for Alternaria toxins and fumonisins were unsatisfying. Matrix effects (-69 to +59%) were compensated for using standard addition. Application on reference materials gave correct results while analysis of samples from local retailers revealed contamination, especially with deoxynivalenol, deoxynivalenol-3-glucoside, fumonisins, and zearalenone, in concentrations up to 369, 58, 1002, and 21 μg/kg, respectively.

Pro-Inflammatory Effects of NX-3 Toxin Are Comparable to Deoxynivalenol and not Modulated by the Co-Occurring Pro-Oxidant Aurofusarin

The type A trichothecene NX-3, produced by certain Fusarium graminearum strains, is similar to the mycotoxin deoxynivalenol (DON), with the exception that it lacks the carbonyl moiety at the C-8 position. NX-3 inhibits protein biosynthesis and induces cytotoxicity to a similar extent as DON, but so far, immunomodulatory effects have not been assessed. In the present study, we investigated the impact of NX-3 on the activity of the nuclear factor kappa B (NF-κB) signaling pathway in direct comparison to DON. Under pro-inflammatory conditions (IL-1β treatment), the impact on cytokine mRNA levels of NF-κB downstream genes was studied in human colon cell lines, comparing noncancer (HCEC-1CT) and cancer cells (HT-29). In addition, potential combinatory effects with the co-occurring Fusarium secondary metabolite aurofusarin (AURO), a dimeric naphthoquinone known to induce oxidative stress, were investigated. NX-3 and DON (1&nbsp;μM, 20 h) significantly activated a NF-κB regulated reporter gene to a similar extent. Both trichothecenes also enhanced transcript levels of the known NF-κB-dependent pro-inflammatory cytokines IL-8, IL-6, TNF-α and IL-1β. Comparing the colon cancer HT-29 and noncancer HCEC-1CT cells, significant differences in cytokine signaling were identified. In contrast, AURO did not affect NF-κB pathway activity and respective cytokine expression levels at the tested concentration. Despite its pro-oxidant potency, the combination with AURO did not significantly affect the immunomodulatory effects of the tested trichothecenes. Taken together, the present study reveals comparable potency of DON and NX-3 with respect to immunomodulatory and pro-inflammatory potential. Consequently, not only DON but also NX-3 should be considered as factors contributing to intestinal inflammatory processes.

Simultaneous Determination of Multiple Mycotoxins in Swine, Poultry and Dairy Feeds Using Ultra High Performance Liquid Chromatography-Tandem Mass Spectrometry

A reliable, sensitive and accurate multiple mycotoxin method was developed for the simultaneous determination of 17 mycotoxins in swine, poultry and dairy feeds using stable isotope dilution (¹³C-ISTD) and (ultra)-high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS). A simple QuEChERS-based method (quick, easy, cheap, effective, rugged and safe) was developed consisting of soaking with a solution of 1% formic acid followed by extraction with acetonitrile, clean-up with C18 sorbent and finally adding ¹³C-ISTD before the UHPLC-MS/MS analysis. The chromatographic condition was optimized for separation and detection of the 17 mycotoxins using gradient elution. The method’s performance complied with the SANTE/11813/2017 standard and had mean recovery accuracies in the range 70%–120% and precision testing of % relative standard deviation (RSD) ≤ 20%. The limit of detection and limit of quantification values ranged from 0.25 to 40.0 ng/g and 0.5 to 100.0 ng/g, respectively. Finally, the method was applied to analyze feed samples, with the results showing that fumonisins, zearalenone, aflatoxin B1 and deoxynivalenol were the most prevalent mycotoxins contaminating the feed samples.

Variation of Fusarium Free, Masked, and Emerging Mycotoxin Metabolites in Maize from Agriculture Regions of South Africa

The presence of mycotoxins in cereal grain is a very important food safety issue with the occurrence of masked mycotoxins extensively investigated in recent years. This study investigated the variation of different Fusarium metabolites (including the related regulated, masked, and emerging mycotoxin) in maize from various agriculture regions of South Africa. The relationship between the maize producing regions, the maize type, as well as the mycotoxins was established. A total of 123 maize samples was analyzed by a LC-MS/MS multi-mycotoxin method. The results revealed that all maize types exhibited a mixture of free, masked, and emerging mycotoxins contamination across the regions with an average of 5 and up to 24 out of 42 investigated Fusarium mycotoxins, including 1 to 3 masked forms at the same time. Data obtained show that fumonisin B1, B2, B3, B4, and A1 were the most prevalent mycotoxins and had maximum contamination levels of 8908, 3383, 990, 1014, and 51.5 µg/kg, respectively. Deoxynivalenol occurred in 50% of the samples with a mean concentration of 152 µg/kg (max 1380 µg/kg). Thirty-three percent of the samples were contaminated with zearalenone at a mean concentration of 13.6 µg/kg (max 146 µg/kg). Of the masked mycotoxins, DON-3-glucoside occurred at a high incidence level of 53%. Among emerging toxins, moniliformin, fusarinolic acid, and beauvericin showed high occurrences at 98%, 98%, and 83%, and had maximum contamination levels of 1130, 3422, and 142 µg/kg, respectively. Significant differences in the contamination pattern were observed between the agricultural regions and maize types.

Toxicity of mycotoxins in vivo on vertebrate organisms: A review

Mycotoxins are considered to be a major risk factor affecting human and animal health as they are one of the most dangerous contaminants of food and feed. This review aims to compile the research developed up to date on the toxicological effects that mycotoxins can induce on human health, through the examination of a selected number of studies in vivo. AFB1 shows to be currently the most studied mycotoxin in vivo, followed by DON, ZEA and OTA. Scarce data was found for FBs, PAT, CIT, AOH and Fusarium emerging mycotoxins. The majority of them concerned the investigation of immunotoxicity, whereas the rest consisted in the study of genotoxicity, oxidative stress, hepatotoxicity, cytotoxicity, teratogenicity and neurotoxicity. In order to assess the risk, a wide range of different techniques have been employed across the reviewed studies: qPCR, ELISA, IHC, WB, LC-MS/MS, microscopy, enzymatic assays, microarray and RNA-Seq. In the last decade, the attention has been drawn to immunologic and transcriptomic aspects of mycotoxins' action, confirming their toxicity at molecular level. Even though, more in vivo studies are needed to further investigate their mechanism of action on human health.

Enniatin Production Influences Fusarium avenaceum Virulence on Potato Tubers, but not on Durum Wheat or Peas

Fusarium avenaceum is a generalist pathogen responsible for diseases in numerous crop species. The fungus produces a series of mycotoxins including the cyclohexadepsipeptide enniatins. Mycotoxins can be pathogenicity and virulence factors in various plant–pathogen interactions, and enniatins have been shown to influence aggressiveness on potato tubers. To determine the role of these mycotoxins in other F. avenaceum–host interactions, ENNIATIN SYNTHASE 1 (ESYN1) disruption and overexpression mutants were generated and their ability to infect wheat and peas investigated. As a preliminary study, the transformants were screened for their ability to cause potato tuber necrosis and, consistent with a previous report, enniatin production increased necrotic lesion size on the tubers. By contrast, when the same mutants were assessed in their ability to cause disease in pea roots or durum wheat spikes, no changes in disease symptoms or virulence were observed. While it is known that, at least in the case of wheat, exogenously applied enniatins can cause tissue necrosis, this group of mycotoxins does not appear to be a key factor on its own in disease development on peas or durum wheat.

Impact of fullerol C60(OH)24 nanoparticles on the production of emerging toxins by Aspergillus flavus

The impact of fullerene C₆₀ water soluble daughter molecules - fullerols C₆₀(OH)₂₄ nanoparticles (FNP) on emerging (non-aflatoxin biosynthetic pathway) toxins production in mycelia and yeast extract sucrose (YES) media of A. flavus was investigated under growth conditions of 29 °C in the dark for a 168 h period. The FNP solution (10, 100 and 1000 ng mL⁻¹) contained predominantly nanoparticles of 8 nm diameter and with zeta potential mean value of −33 mV. Ten emerging metabolites were produced at concentrations reaching 1,745,035 ng 50 mL⁻¹ YES medium. Seven of the metabolites were found in mycelia and media, while three were only in mycelia. Majority of the metabolites were detected in higher quantity in mycelia than in media, at a ratio of 99:1 (m/m). However, higher metabolite quantities were found in media following FNP application, while FNP caused a decrease of total metabolite quantities in mycelia. The concentrations of the metabolites in media increased in the presence of 1000 ng mL⁻¹ FNP while mycelial quantities of the metabolites decreased with increased applied FNP dose. The impacts of global climate changes on FNP availability in the environment and on mycotoxin occurrence in crops increase the relevance of this study for risk assessment of nanoparticles. Cordycepin is reported for the first time as metabolite of A. flavus.

Mycotoxins in maize harvested in Republic of Serbia in the period 2012-2015. Part 1: Regulated mycotoxins and its derivatives

The main objective of this study was to apply a liquid chromatography-tandem mass spectrometric method to investigate the presence of 20 mycotoxins in 204 maize samples harvested in Northern Serbia in the period 2012-2015, including seasons with extreme drought (2012), hot and dry conditions (2013 and 2015) and extreme precipitation (2014). Between 2 and 20 mycotoxins contaminated examined samples. In samples collected from each year, all of six examined fumonisins were detected with very high prevalence (from 76% to 100%). Aflatoxin B₁ was detected in 94% and 90% maize samples from 2012 and 2015, respectively. In samples from year 2014, deoxynivalenol, zearalenone and its derivatives were detected in 100% of samples. Furthermore, ochratoxin A (25%) was the most predominant in samples from 2012. The obtained results indicate that changes in weather conditions, recorded in the period of four years, had significant influence on the occurrence of examined mycotoxins in maize.

Multimycotoxin Determination in Tunisian Farm Animal Feed

Mycotoxins presence was evaluated in animal feed marketed in Tunisia for the first time ever. A QuEChERS method was performed to analyze the natural copresence of 22 mycotoxins (enniatins, beauvericin, ochratoxin A, aflatoxins, alternariol monomethyl ether, alternariol, tentoxin, zearalenone, deoxynivalenol, 3-acetyldeoxynivalenol, 15-acetyldeoxynivalenol, nivalenol, neosolaniol, diacetoxyscirpenol, T-2 toxin, and HT-2 toxin) in 122 Tunisian marketed feed samples, intended for poultry (n = 43), cattle (n = 35), rabbit (n = 12), sheep (n = 16), and horse (n = 16). Analytes detection and quantification were done using both liquid chromatography and gas chromatography coupled to tandem mass spectrometry. The analytical method showed good linearity (R > 0.996) and sensitivity, the limits of quantification ranged from 0.1 ng/g (enniatin A1) to 225 ng/g (3-acetyldeoxynivalenol). Eighty-five percent of the analyzed samples were positive. Poultry (n = 43) and rabbit (n = 12) feed samples were the most contaminated. Enniatin B was the most prevalent mycotoxin with values ranged between 0.5 ng/g for horse feed and 40 ng/g for poultry feed, followed by deoxynivalenol detected from 16 ng/g in cattle feed to 250 ng/g in poultry feed. None exceeded the limits set by EU recommendations for animal feed. Mycotoxins co-occurrence was observed at most by five different mycotoxins (26%) and up to eight mycotoxins was recorded in 5% of samples. Furthermore, a relatively high copresence rate of different fusariotoxins was registered. Even if no toxicological concern was clearly revealed, the contamination is a real fact and will probably present influence on meat production and on food safety.

Mycotoxins in Flanders' Fields: Occurrence and Correlations with Fusarium Species in Whole-Plant Harvested Maize

Mycotoxins are well-known contaminants of several food- and feedstuffs, including silage maize for dairy cattle. Climate change and year-to-year variations in climatic conditions may cause a shift in the fungal populations infecting maize, and therefore alter the mycotoxin load. In this research, 257 maize samples were taken from fields across Flanders, Belgium, over the course of three years (2016-2018) and analyzed for 22 different mycotoxins using a multi-mycotoxin liquid chromatography-tandem mass spectrometry (LC-MS/MS) method. DNA of Fusarium graminearum, F. culmorum and F. verticillioides was quantified using the quantitative polymerase chain reaction (qPCR). Multi-mycotoxin contamination occurred frequently, with 47% of samples containing five or more mycotoxins. Nivalenol (NIV) was the most prevalent mycotoxin, being present in 99% of the samples, followed by deoxynivalenol (DON) in 86% and zearalenone (ZEN) in 50% of the samples. Fumonisins (FUMs) were found in only 2% of the samples in the wet, cold year of 2016, but in 61% in the extremely hot and dry year of 2018. Positive correlations were found between DON and NIV and between F. graminearum and F. culmorum, among others. FUM concentrations were not correlated with any other mycotoxin, nor with any Fusarium sp., except F. verticillioides. These results show that changing weather conditions can influence fungal populations and the corresponding mycotoxin contamination of maize significantly, and that multi-mycotoxin contamination increases the risk of mycotoxicosis in dairy cattle.

The Influence of Steeping Water Change during Malting on the Multi-Toxin Content in Malt

The aim of this study was to assess the impact of steeping water change and Fusarium graminearum contamination level on different multi-toxin types and concentrations in barley malt. Malt samples were subjected to two micromalting regimes-steeping water change and the other with no steeping water change. Malt was contaminated with different F. graminearum contamination levels (0%, 10%, and 20%). The results indicate that malt with higher F. graminearum contamination levels ensured higher concentrations of toxins. Higher fungal metabolite concentrations were determined in samples exposed to freshly-changed steeping water, especially zearalenone and its derivates whose values were three to four times higher than in samples with no water change. Zearalenone-4-sulfate showed four (in 10% contamination) and even thirty times (in 20% contamination) higher concentrations than in samples with no water change. Water change during malting resulted in higher levels of multi-toxins in the final product.

Retrospective and Prospective Look at Aflatoxin Research and Development from a Practical Standpoint

Among the array of structurally and toxicologically diverse mycotoxins, aflatoxins have attracted the most interest of scientific research due to their high toxicity and incidence in foods and feeds. Despite the undeniable progress made in various aspects related to aflatoxins, the ultimate goal consisting of reducing the associated public health risks worldwide is far from being reached due to multiplicity of social, political, economic, geographic, climatic, and development factors. However, a reasonable degree of health protection is attained in industrialized countries owing to their scientific, administrative, and financial capacities allowing them to use high-tech agricultural management systems. Less fortunate situations exist in equatorial and sub-equatorial developing countries mainly practicing traditional agriculture managed by smallholders for subsistence, and where the climate is suitable for mould growth and aflatoxin production. This situation worsens due to climatic change producing conditions increasingly suitable for aflatoxigenic mould growth and toxin production. Accordingly, it is difficult to harmonize the regulatory standards of aflatoxins worldwide, which prevents agri-foods of developing countries from accessing the markets of industrialized countries. To tackle the multi-faceted aflatoxin problem, actions should be taken collectively by the international community involving scientific research, technological and social development, environment protection, awareness promotion, etc. International cooperation should foster technology transfer and exchange of pertinent technical information. This review presents the main historical discoveries leading to our present knowledge on aflatoxins and the challenges that should be addressed presently and in the future at various levels to ensure higher health protection for everybody. In short, it aims to elucidate where we come from and where we should go in terms of aflatoxin research/development.

Synergistic Phytotoxic Effects of Culmorin and Trichothecene Mycotoxins

Species of the fungus Fusarium cause Fusarium head blight (FHB) of cereal crops and contaminate grain with sesquiterpenoid mycotoxins, including culmorin (CUL) and trichothecenes. While the phytotoxicity of trichothecenes, such as deoxynivalenol (DON), and their role in virulence are well characterized, less is known about the phytotoxicity of CUL and its role in the development of FHB. Herein, we evaluated the phytotoxic effects of purified CUL and CUL-trichothecene mixtures using Chlamydomonas reinhardtii growth and Triticum aestivum (wheat) root elongation assays. By itself, CUL did not affect growth in either system. However, mixtures of CUL with DON, 3-acetyldeoxynivalenol, 15-acetyldeoxynivalenol, or NX-3, but not with nivalenol, inhibited growth in a synergistic manner. Synergistic phytotoxic effects of CUL and DON were also observed on multiple plant varieties and species. The severity of wheat FHB caused by 15 isolates of Fusarium graminearum was negatively correlated with the CUL/DON ratio, but positively correlated with the sum of both CUL and DON. Additionally, during the first week of infection, CUL biosynthetic genes were more highly expressed than the TRI5 trichothecene biosynthetic gene. Furthermore, genomic analysis of Fusarium species revealed that CUL and trichothecene biosynthetic genes consistently co-occur among species closely related to F. graminearum.

Assessment of Dried Blood Spots for Multi-Mycotoxin Biomarker Analysis in Pigs and Broiler Chickens

Dried blood spots (DBSs), a micro-sampling technique whereby a drop of blood is collected on filter paper has multiple advantages over conventional blood sampling regarding the sampling itself, as well as transportation and storage. This is the first paper describing the development and validation of a method for the determination of 23 mycotoxins and phase I metabolites in DBSs from pigs and broiler chickens using liquid chromatography-tandem mass spectrometry (LC-MS/MS). The targeted mycotoxins belong to groups for which the occurrence in feed is regulated by the European Union, namely, aflatoxins, ochratoxin A and several Fusarium mycotoxins, and to two groups of unregulated mycotoxins, namely Alternaria mycotoxins and Fusarium mycotoxins (enniatins and beauvericin). The impact of blood haematocrit, DBS sampling volume and size of the analysed DBS disk on the validation results was assessed. No effects of variation in size of the analysed disk, haematocrit and spotted blood volume were observed for most mycotoxins, except for the aflatoxins and β-zearalanol (BZAL) at the lowest haematocrit (26%) level and for the enniatins (ENNs) at the lowest volume (40 µL). The developed method was transferred to an LC-high resolution mass spectrometry instrument to determine phase II metabolites. Then, the DBS technique was applied in a proof-of-concept toxicokinetic study including a comparison with LC-MS/MS data from plasma obtained with conventional venous blood sampling. A strong correlation (r > 0.947) was observed between plasma and DBS concentrations. Finally, DBSs were also applied in a pilot exposure assessment study to test their applicability under field conditions.

Twenty-Eight Fungal Secondary Metabolites Detected in Pig Feed Samples: Their Occurrence, Relevance and Cytotoxic Effects In Vitro

Feed samples are frequently contaminated by a wide range of chemically diverse natural products, which can be determined using highly sensitive analytical techniques. Next to already well-investigated mycotoxins, unknown or unregulated fungal secondary metabolites have also been found, some of which at significant concentrations. In our study, 1141 pig feed samples were analyzed for more than 800 secondary fungal metabolites using the same LC-MS/MS method and ranked according to their prevalence. Effects on the viability of the 28 most relevant were tested on an intestinal porcine epithelial cell line (IPEC-J2). The most frequently occurring compounds were determined as being cyclo-(L-Pro-L-Tyr), moniliformin, and enniatin B, followed by enniatin B1, aurofusarin, culmorin, and enniatin A1. The main mycotoxins, deoxynivalenol and zearalenone, were found only at ranks 8 and 10. Regarding cytotoxicity, apicidin, gliotoxin, bikaverin, and beauvericin led to lower IC50 values, between 0.52 and 2.43 µM, compared to deoxynivalenol (IC50 = 2.55 µM). Significant cytotoxic effects were also seen for the group of enniatins, which occurred in up to 82.2% of the feed samples. Our study gives an overall insight into the amount of fungal secondary metabolites found in pig feed samples compared to their cytotoxic effects in vitro.

Plant-based milks: unexplored source of emerging mycotoxins. A proposal for the control of enniatins and beauvericin using UHPLC-MS/MS

Mycotoxins have become one of the most common contaminants reported worldwide. Current legislation has established maximum levels only for some well-known mycotoxins; however, there are many other "emerging mycotoxins" for which there is no regulation, as enniatins and beauvericin. An analytical method based on salting-out assisted liquid-liquid extraction followed by ultra-high performance liquid chromatography tandem mass spectrometry is proposed for determination of enniatin A, A1, B, B1, and beauvericin in different plant-based milks, as a possible source of these contaminants, is proposed. The method showed good precision and trueness (RSD <8% and recoveries between 84-97%) with a moderate matrix effect. From a total of 32 samples of plant-based milks of different compositions (including 8 rice milks, 8 oat milks and 16 soy milks), 3 samples were contaminated with the five mycotoxins, while 5 samples were contaminated with four of them, being oat milk the most susceptible for contamination.

Biotransformation of the Mycotoxin Zearalenone to its Metabolites Hydrolyzed Zearalenone (HZEN) and Decarboxylated Hydrolyzed Zearalenone (DHZEN) Diminishes its Estrogenicity In Vitro and In Vivo

Zearalenone (ZEN)-degrading enzymes are a promising strategy to counteract the negative effects of this mycotoxin in livestock. The reaction products of such enzymes need to be thoroughly characterized before technological application as a feed additive can be envisaged. Here, we evaluated the estrogenic activity of the metabolites hydrolyzed zearalenone (HZEN) and decarboxylated hydrolyzed zearalenone (DHZEN) formed by hydrolysis of ZEN by the zearalenone-lactonase Zhd101p. ZEN, HZEN, and DHZEN were tested in two in vitro models, the MCF-7 cell proliferation assay (0.01–500 nM) and an estrogen-sensitive yeast bioassay (1–10,000 nM). In addition, we compared the impact of dietary ZEN (4.58 mg/kg) and equimolar dietary concentrations of HZEN and DHZEN on reproductive tract morphology as well as uterine mRNA and microRNA expression in female piglets (n = 6, four weeks exposure). While ZEN increased cell proliferation and reporter gene transcription, neither HZEN nor DHZEN elicited an estrogenic response, suggesting that these metabolites are at least 50–10,000 times less estrogenic than ZEN in vitro. In piglets, HZEN and DHZEN did not increase vulva size or uterus weight. Moreover, RNA transcripts altered upon ZEN treatment (EBAG9, miR-135a-5p, miR-187-3p and miR-204-5p) were unaffected by HZEN and DHZEN. Our study shows that both metabolites exhibit markedly reduced estrogenicity in vitro and in vivo, and thus provides an important basis for further evaluation of ZEN-degrading enzymes.

MicroRNAs in porcine uterus and serum are affected by zearalenone and represent a new target for mycotoxin biomarker discovery

The mycotoxin zearalenone (ZEN) poses a risk to animal health because of its estrogenic effects. Diagnosis of ZEN-induced disorders remains challenging due to the lack of appropriate biomarkers. In this regard, circulating microRNAs (small non-coding RNAs) have remarkable potential, as they can serve as indicators for pathological processes in tissue. Thus, we combined untargeted and targeted transcriptomics approaches to investigate the effects of ZEN on the microRNA expression in porcine uterus, jejunum and serum, respectively. To this end, twenty-four piglets received uncontaminated feed (Control) or feed containing 0.17 mg/kg ZEN (ZEN low), 1.46 mg/kg ZEN (ZEN medium) and 4.58 mg/kg ZEN (ZEN high). After 28 days, the microRNA expression in the jejunum remained unaffected, while significant changes in the uterine microRNA profile were observed. Importantly, 14 microRNAs were commonly and dose-dependently affected in both the ZEN medium and ZEN high group, including microRNAs from the miR-503 cluster (i.e. ssc-miR-424-5p, ssc-miR-450a, ssc-miR-450b-5p, ssc-miR-450c-5p, ssc-miR-503 and ssc-miR-542-3p). Predicted target genes for those microRNAs are associated with regulation of gene expression and signal transduction (e.g. cell cycle). Although the effects in serum were less pronounced, receiver operating characteristic analysis revealed that several microRNA ratios were able to discriminate properly between non-exposed and ZEN-exposed pigs (e.g. ssc-miR-135a-5p/ssc-miR-432-5p, ssc-miR-542-3p/ssc-miR-493-3p). This work sheds new light on the molecular mechanisms of ZEN, and fosters biomarker discovery.