Toxicological evaluation of trichothecenes in animal feed

The effect of feeding a diet naturally contaminated with deoxynivalenol on production traits and selected biochemical indicators of broiler chickens

The effect of feeding a diet naturally contaminated with deoxynivalenol (DON) (0-21 days: 1.50 mg·kg-1; 22-39 days: 1.54 mg·kg-1) was studied in 40 broiler chickens. Birds were divided into two groups fed a control diet and a diet contaminated with DON (n = 20 in each). Feed intake was measured daily and individual live weight weekly; daily weight gain and feed to gain ratio were calculated. Five animals from each group were euthanized on days 21and 39 when blood (blood plasma and red blood cell haemolysates) and liver samples were collected. Concentration of triglyceride, uric acid and glucose and activities of ALT, AST and LDH were measured in blood plasma. Indicators of lipid peroxide and glutathione redox status, malondialdehyde and reduced glutathione concentration and glutathione-peroxidase activity were measured in blood plasma, red blood cell haemolysates and liver homogenates. The low dose of DON did not cause difference in the production traits, but caused significantly lower concentration of uric acid and glucose, and significantly higher concentration of triglyceride in blood plasma on day 21. Enzyme activities in blood plasma did not differ significantly between the treatment groups. Among the markers of lipid peroxide and glutathione redox status, malondialdehyde content was significantly higher in liver homogenate on day 21 in the group fed with DON contaminated diet, but reduced glutathione content and glutathione peroxidase activity did not differ significantly between the treatment groups. The results showed that diet contaminated even with a low content of deoxynivalenol caused alterations in selected biochemical indicators of blood and liver of broiler chicken.

Mechanisms of mycotoxin-induced neurotoxicity through oxidative stress-associated pathways

Among many mycotoxins, T-2 toxin, macrocyclic trichothecenes, fumonisin B(1) (FB(1)) and ochratochin A (OTA) are known to have the potential to induce neurotoxicity in rodent models. T-2 toxin induces neuronal cell apoptosis in the fetal and adult brain. Macrocyclic trichothecenes bring about neuronal cell apoptosis and inflammation in the olfactory epithelium and olfactory bulb. FB(1) induces neuronal degeneration in the cerebral cortex, concurrent with disruption of de novo ceramide synthesis. OTA causes acute depletion of striatal dopamine and its metabolites, accompanying evidence of neuronal cell apoptosis in the substantia nigra, striatum and hippocampus. This paper reviews the mechanisms of neurotoxicity induced by these mycotoxins especially from the viewpoint of oxidative stress-associated pathways.

N-acetyl-cysteine protects chicken growth plate chondrocytes from T-2 toxin-induced oxidative stress

T-2 toxin is now considered to be related to bone malformation such as incomplete ossification, absence of bones and fused bones. In this study, primary cultures of chicken tibial growth plate chondrocytes (GPCs) were treated with various concentrations of T-2 toxin (5, 50, and 500 n m) in the absence and presence of N-acetyl-cysteine (NAC) to investigate the effects of the antioxidant NAC on T-2 toxin-induced toxicity. Our results showed that T-2 toxin markedly decreased cell viability, alkaline phosphatase activity and glutathione content (P < 0.05). In addition, T-2 toxin significantly increased reactive oxygen species levels and malondialdehyde in a dose-dependent manner. However, the T-2 toxin-induced cytotoxicity was reversed, in part, by the antioxidant NAC (P < 0.05). These results suggest that T-2 toxin inhibits the proliferation and differentiation of GPCs in vitro by altering cellular homeostasis and NAC can protect GPCs against T-2 toxin cytotoxicity by reducing the T-2 toxin-induced oxidative stress.

Effects of excessive selenium supplementation to diet contaminated with deoxynivalenol on blood phagocytic activity and antioxidative status of broilers

This study examined the effects of excessive dietary supplementation with organic selenium on phagocytic activity and antioxidative status of chickens for fattening fed diet contaminated with deoxynivalenol (DON). Sixty chickens of Ross 308 hybrids were at day of hatching divided into four groups with 15 birds in each. The background DON dietary levels in both negative and positive control groups were 0.2 mg/kg. The complete feed for positive control group was supplemented with Se dose 1 mg/kg in the form of Se-yeast. Group 3 was fed diet with DON level 3 mg/kg while diet for group 4 combined DON level 3 mg/kg with a excessive supplement of Se-yeast (Se dose 1 mg/kg). After 6 weeks of dietary intake, six randomly-chosen chickens from each group were sampled. Feeding of contaminated diet resulted in significantly reduced blood phagocytic activity (19.5 ± 1.1% in the negative control vs. 12.8 ± 0.8% in the DON-treated group, p < 0.05). Se-yeast supplemented to the DON contaminated diet prevented suppression of phagocytic activity. Dietary intake of DON at levels 3 mg/kg did not influence the plasma α-tocopherol level while excessive dietary Se dose reduced it in both Se supplemented groups. Neither the birds of DON-treated group nor the birds from group 4 with DON and Se-yeast showed any response in plasma γ-glutamyltransferase (GGT) activity. Subtoxic dietary level of DON significantly increased the activity of glutathione peroxidase (GPx) in the duodenal mucosa, while additional Se supplementation prevented such a response to mycotoxin. On the other hand, both Se supplemented groups showed significantly elevated GPx activities in blood, liver and kidney, (p < 0.05). The results suggest a potential ability of excessive supplementation of organic selenium to prevent the blood phagocytic activity suppression and changes in GPx activity in duodenal tissue induced in broilers by subtoxic dietary levels of DON.

Integrated transcriptional and proteomic analysis with in vitro biochemical assay reveal the important role of CYP3A46 in T-2 toxin hydroxylation in porcine primary hepatocytes

Both T-2 toxin and its metabolites are highly potent mycotoxins that can cause severe human and animal diseases upon exposure. Understanding the toxic mechanism and biotransformation process of T-2 toxin at a cellular level is essential for the development of counter-measures. We investigated the effect of T-2 toxin in porcine primary hepatocytes using porcine genome array and two-dimensional difference gel electrophoresis with matrix-assisted laser desorption/ionization tandem time of flight mass spectrometry. Integrated transcriptional and proteomic analysis demonstrated that T-2 toxin adversely affected porcine hepatocytes by initiating lipid metabolism disorder, oxidative stress response, and apoptosis. In addition, xenobiotic metabolism genes, including cytochrome P450 3As (CYP3A46 and CYP3A39), carboxylesterase 1Cs (CES1C4 and CES1C5), and epoxide hydrolase (EPHX1), increased in T-2 toxin treatment cells. Using HepG2 cells to over-express the recombinant xenobiotic metabolism genes above and rapid resolution liquid chromatography/tandem mass spectrometry to detect metabolites of T-2 toxin, we determined that porcine CYP3A46 mainly catalyzed T-2 to form 3'-hydroxy-T-2, which was further confirmed by purified CYP3A46 protein. However, recombinant porcine CES1C5 and EPHX1 did not enhance hydrolysis and de-epoxidation of T-2 implying that other esterases and epoxide hydrolases may play dominant roles in those reactions.

Efficacy of detoxification of deoxynivalenol-contaminated corn by Bacillus sp. LS100 in reducing the adverse effects of the mycotoxin on swine growth performance

Biodetoxification of mycotoxins is a novel strategy to control mycotoxicoses in animals. Bacillus sp. LS100, which transforms deoxynivalenol (DON) to a less toxic chemical de-epoxy DON (DOM-1), was evaluated for its efficacy in reducing the adverse effects of DON on swine growth performance. A feeding trial was conducted in growing pigs with four treatments: (1) corn meal without detectable DON served as control (Non-toxic Corn); (2) Fusarium-infected corn giving a toxic diet containing 5 µg DON g(-1) (Toxic Corn); (3) Toxic Corn detoxified with Bacillus sp. LS100 giving a detoxified diet containing 5 µg DOM-1 g(-1) (LS100-De-toxic Corn); (4) Non-toxic Corn treated with Bacillus sp. LS100 serving as bacterial control (LS100-Non-toxic Corn). During 9 days of exposure to the treatments, pigs on Toxic Corn showed a significant reduction in daily feed consumption, daily weight gain and feed efficiency by 29, 48 and 29%, respectively, compared to pigs on Non-toxic Corn. These parameters of the pigs fed LS100-De-toxic Corn diet were 45, 82 and 32% greater, respectively, than those of pigs fed Toxic Corn diet, and were similar to those pigs fed Non-toxic Corn and LS100-Non-toxic Corn diets. There were no significant differences between the treatments of LS100-Non-toxic Corn and Non-toxic Corn diets, implying that the bacterial isolate might not have significantly affected nutrition and palatability of the feed or had negative effects on the pig's feeding performance. The results have proved that microbial detoxification of DON in contaminated feed can eliminate negative effects of the mycotoxin, and the pre-feeding detoxification approach may be applied in the livestock industry.

Acoustic sensing of deoxynivalenol in co-occurrence with zearalenone and T-2/HT-2 toxin in winter wheat cultivar Sirvinta from Lithuania

A fast acoustic screening method in combination with an ELISA method was applied for the detection of deoxynivalenol (DON) in co-occurrence with some trichothecenes such as zearalenone (ZEA) and T-2/HT-2 toxins in winter wheat grains (Triticum aestivum L.) of the most popular Lithuanian cultivar Sirvinta. Strong correlations between the amplitude of the acoustic signal that penetrated the wheat samples and DON as well as total amount of mentioned trichothecenes quantified by ELISA method were found (R2=0.787 and R2=0.794, respectively). It turned out that weak correlations between the acoustic signal and the concentrations of ZEA and T-2/HT-2 were found. These correlations suggest that DON is the marker of the Fusarium infected wheat grain. This statement is also strengthened by the fact that DON is the most significant trichothecene contaminant of cereal grains in the world and levels are generally higher in the wetter climates. The dependency determined between the acoustic signal and structural physical characteristics (1000-kernel-weight) of the grain matrix could therefore be the basis for the developed rapid acoustic method for cereal quality and safety control. Additional examination of microstructure of wholesome and Fusarium-affected kernels under the scanning electron microscope revealed that obvious damage to the starch granules and lack of protein matrix was caused by the increase in several enzyme activities in the infected grains. Moderate positive relationships between α-amylase, protease and xylanase activities, and the degree of Fusarium infection were found (for α-amylase R2=0.623, for protease R2=0.823, and for xylanase R2=0.682). An intriguing characterisation may contribute to explanations as to how and to what extent wheat starch granules of different sizes stay more or less intact by slightly infected grains while the wheat starch granules are damaged and/ or completely destroyed by seriously infected grains. The changes of the protease activity had a slightly detectable influence on the crude protein content in seriously infected grain samples which might have an effect on dough properties and the quality of bread.

Cross-reactivity of antibodies in some commercial deoxynivalenol test kits against some fusariotoxins

Cross-reactivity of antibodies in AGRAQUANT, DON EIA, VERATOX, ROSA LF-DONQ, and MYCONTROLDON designed for deoxynivalenol (DON) determination in food and feedstuffs was evaluated against nivalenol, 3-acetylDON, 15-acetylDON, de-epoxy metabolite 1 of DON, DON-3β-glucoside, T2-toxin, HT2-toxin, fusarenone X, diacetoxyscirpenol, verrucarol, and zearalenone. Cross-reactivity measurements were run in water using the 50% reduction of absorbance of the blank for ELISA kits or through direct DON determination upon using the standards of mycotoxins via ROSA LF-DONQ or MYCONTROLDON. For the tested toxin concentrations, all DON kits have low cross-reactivity toward diacetoxyscirpenol, T2-toxin, HT2-toxin, verrucarol, and zearalenone and moderate cross-reactivity toward 15-AcetylDON and fusarenone X. AGRAQUANT, DON EIA, and VERATOX kits showed high cross-reactivity in various ranking orders against DON-3-Glc, DOM-1, and 3AcDON. DON EIA showed also high cross-reactivity against nivalenol and fusarenone X. These mycotoxins could coexist in food or feedstuffs, and analytical results can be wrongly interpreted. Cross-reactivity does not allow checking the compliance with the legal norms, but it does allow an overall risk assessment for the consumers. Updating regularly the cross-reactivity evaluation of the produced batches is recommended for 3-acetylDON, nivalenol, DON-3-Glc, de-epoxy metabolite 1, and fusarenone X.

Toxicological mechanisms and potential health effects of deoxynivalenol and nivalenol

Produced by the mould genus Fusarium, the type B trichothecenes include deoxynivalenol (DON), nivalenol (NIV) and their acetylated precursors. These mycotoxins often contaminate cereal staples, posing a potential threat to public health that is still incompletely understood. Understanding the mechanistic basis by which these toxins cause toxicity in experimental animal models will improve our ability to predict the specific thresholds for adverse human effects as well as the persistence and reversibility of these effects. Acute exposure to DON and NIV causes emesis in susceptible species such as pigs in a manner similar to that observed for certain bacterial enterotoxins. Chronic exposure to these mycotoxins at low doses causes growth retardation and immunotoxicity whereas much higher doses can interfere with reproduction and development. Pathophysiological events that precede these toxicities include altered neuroendocrine responses, upregulation of proinflammatory gene expression, interference with growth hormone signalling and disruption of gastrointestinal tract permeability. The underlying molecular mechanisms involve deregulation of protein synthesis, aberrant intracellular cell signalling, gene transactivation, mRNA stabilisation and programmed cell death. A fusion of basic and translational research is now needed to validate or refine existing risk assessments and regulatory standards for DON and NIV. From the perspective of human health translation, biomarkers have been identified that potentially make it possible to conduct epidemiological studies relating DON consumption to potential adverse human health effects. Of particular interest will be linkages to growth retardation, gastrointestinal illness and chronic autoimmune diseases. Ultimately, such knowledge can facilitate more precise science-based risk assessment and management strategies that protect consumers without reducing availability of critical food sources.

Effects of feeding diets contaminated with Fusarium mycotoxins on blood biochemical parameters of broiler chickens

This study was conducted to investigate the effects of deoxynivalenol (DON) and zearalenone (ZEA) on some biochemical indices of broiler chickens. Twenty-four Ross 308 hybrid broiler chickens of both sexes were fed diets containing maize contaminated with Fusarium mycotoxins. The diets included a control diet (DON 0.60 mg/kg feed; ZEA 0.07 mg/kg feed), an experimental 1 diet (DON 3.4 mg kg⁻¹ feed; ZEA 3.4 mg kg⁻¹ feed), and an experimental 2 diet (DON 8.2 mg kg⁻¹ feed; ZEA 8.3 mg kg⁻¹ feed). Contaminated diets were fed from 14 days of age for 14 days. Blood samples were collected from 4-week-old birds. Chicks fed a diet containing a low level of contaminated maize (experimental 1) had decreased plasma potassium, magnesium, phosphorus, total protein, albumin, triglycerides, free glycerol concentrations and increased cholesterol and calcium levels as well as alkaline phosphatase (ALP) and aspartate aminotransferase (AST) enzyme activities as compared to the control. Feeding a diet contaminated with high levels of mycotoxins (experimental 2) resulted in decreased plasma potassium, magnesium, total protein, albumin, triglycerides, free glycerol concentrations and increased plasma ALP, alanine aminotransferase (ALT) and AST enzyme activities. The effect of mycotoxin-contaminated diets on ALP activity was dose dependent. Chloride concentration was not affected by the diets. It can be concluded that feeding diets contaminated with both levels of Fusarium mycotoxins significantly affected protein, lipid and mineral metabolism as well as AST and ALP enzyme activities in broiler chickens.

Biomonitoring of Fusarium spp. Mycotoxins: Perspectives for an Individual Exposure Assessment Tool

Fusarium species are probably the most prevalent toxin-producing fungi of the northern temperate regions and are commonly found on cereals grown in the temperate regions of America, Europe and Asia. Among the toxins formed by Fusarium we find trichothecenes of the A-type or B-type, zearalenone, fumonisins or nivalenol. The current exposure assessment consists of the qualitative and/or quantitative evaluation based on the knowledge of the mycotoxin occurrence in the food and the dietary habits of the population. This process permits quantifying the mycotoxin dietary intake through deterministic or probabilistic methods. Although these methods are suitable to assess the exposure of populations to contaminants and to identify risk groups, they are not recommended to evaluate the individual exposition, due to a low accuracy and sensitivity. On the contrary, the use of biochemical indicators has been proposed as a suitable method to assess individual exposure to contaminants. In this work, several techniques to biomonitor the exposure to fumonisins, deoxynivalenol, zearalenone or T-2 toxin have been reviewed.

Effects of deoxynivalenol (DON) in the lactation diet on the feed intake and fertility of sows

A diet contaminated with 2.8 mg deoxynivalenol (DON)/kg was fed at 6 kg per day to 32 mycotoxin-exposed pluriparous sows (M) during lactation. The 31 control sows (C) received 6 kg of an uncontaminated diet. Although more contaminated diet was refused (P = 0.05), DON exposure had no effect (P > 0.1) on body weight loss of the sows during lactation (M: 27.9 ± 12.3 kg; C: 29.7 ± 10.2 kg), the number of weaned piglets (M: 9.8 ± 1.4; C: 9.7 ± 1.6) and their daily weight gain (M: 266 ± 70 g; C: 272 ± 64 g). Several sows were culled after weaning for reasons unrelated to the experiment. Compared with the remaining 21 C sows, the remaining 26 M sows had an identical interval between weaning and the next farrowing (M: 120 ± 1 days; C: 120 ± 1 days) and a similar litter size (M: 14.5 ± 2.7; C: 14.9 ± 3.0; P > 0.10). The daily intake of 17 mg DON during lactation thus did not affect the reproductive performance of the sows.

Real and perceived risks for mycotoxin contamination in foods and feeds: challenges for food safety control

Mycotoxins are toxic compounds, produced by the secondary metabolism of toxigenic moulds in the Aspergillus, Alternaria, Claviceps, Fusarium, Penicillium and Stachybotrys genera occurring in food and feed commodities both pre- and post-harvest. Adverse human health effects from the consumption of mycotoxins have occurred for many centuries. When ingested, mycotoxins may cause a mycotoxicosis which can result in an acute or chronic disease episode. Chronic conditions have a much greater impact, numerically, on human health in general, and induce diverse and powerful toxic effects in test systems: some are carcinogenic, mutagenic, teratogenic, estrogenic, hemorrhagic, immunotoxic, nephrotoxic, hepatotoxic, dermotoxic and neurotoxic. Although mycotoxin contamination of agricultural products still occurs in the developed world, the application of modern agricultural practices and the presence of a legislatively regulated food processing and marketing system have greatly reduced mycotoxin exposure in these populations. However, in developing countries, where climatic and crop storage conditions are frequently conducive to fungal growth and mycotoxin production, much of the population relies on subsistence farming or on unregulated local markets. Therefore both producers and governmental control authorities are directing their efforts toward the implementation of a correct and reliable evaluation of the real status of contamination of a lot of food commodity and, consequently, of the impact of mycotoxins on human and animal health.

Effects of fusarium infection on the phenolics in emmer and naked barley

Inoculated or non-inoculated naked barley and emmer cultivars were investigated with regard to their influence on phenolic acid profiles and their arabinoxylan content. Two groups of phenolic compounds were differentiated-methanol-soluble and hydrolyzable covalent-bound phenolic compounds. Chromatographic methods were applied for their analysis. The results showed ferulic acid as the predominant phenol in both total and covalent-bound fractions. The inoculation significantly reduced the ferulic acid content within a range of 5.6-6.6% in the two cereals and all their cultivars. Naked barley cultivars additionally contained the flavonoid catechin in the soluble fraction. The innoculation led here to a significant increase in the catechin content of about 4.5%. These results document an induction of the synthesis of catechin in naked barley after artificial Fusarium infection, whereas the ferulic acid content declined.

Study on the effect of T-2 toxin combined with low nutrition diet on rat epiphyseal plate growth and development

The purpose of this study was to observe early lesions of rat epiphyseal plates and metaphysis caused by T-2 toxin and T-2 toxin combined with a low nutrition diet to determine possible pathogenic factors of Kashin-Beck disease (KBD). Ninety Wistar rats were divided into three groups. Group A was fed with a normal diet as control; group B was fed with a normal diet and T-2 toxin; and group C was fed with a low nutrition diet and T-2 toxin. The left knee specimens were collected, fixed in formaldehyde solution, stained by hematoxylin and eosin and Masson. After two weeks, the epiphyseal plate showed necrosis of chondrocytes in groups B and C. After four weeks, more obvious chondrocyte necrosis appeared. The positive rate of Lamellar necrosis in group C was significantly higher than that in groups B and A (P < 0.01). Metaphyseal trabecular bone showed sparse disorder and disruption in group C. T-2 toxin combined with a low nutrition diet could lead to more serious chondrocyte necrosis in the epiphyseal plate and disturb metaphyseal trabecular bone formation.

Assessment of deoxynivalenol (DON) adsorbents and characterisation of their efficacy using complementary in vitro tests

Deoxynivalenol (DON) is a prevalent and resistant mycotoxin found in cereals and related products. Adsorbents appear to provide an opportunity to decrease DON absorption in animals but, due to their specificity, it is very difficult to evaluate their actual efficacy. It is pointless to extrapolate results obtained with one mycotoxin to another and even to extrapolate results obtained in vitro in buffer to an in vivo situation. We carried out experiments to characterize the properties of potential DON adsorbents. Initial tests in buffer pH 7 allowed us to focus on six adsorbents: activated charcoal, cholestyramin, Saccharomyces cerevisiae mannans, algal beta-glycan, fungal beta-glycan and leguminous plant. The use of equilibrium sorption models suggested a non-saturated phenomenon and involved variable mechanisms according to the specific material. Subsequent tests with a Caco-2 cell model showed a high reduction in DON cytotoxicity on proliferative intestinal cells and DON absorption by differentiated intestinal cells when adsorbent was added (except for cholestyramin). Otherwise, values were not always in accordance with those obtained in buffer. Our work allowed us to identify five potential DON adsorbents and to propose a complementary in vitro test allowing improved determination of adsorbent properties.

Effect of T-2 and HT-2 Toxin during the Growing Period on Body Weight, Lipid Peroxide and Glutathione Redox Status of Broiler Chickens

The effect of T-2 and HT-2 toxin using different doses in the starter (0-21 days: 1.04 mg T-2 toxin and 0.49 mg HT-2 toxin kg-1feed), and finisher diets (22-39 days: 0.12 mg T-2 toxin and 0.02 mg HT-2 toxin kg-1feed) was investigated in broiler chickens. Birds were divided into two groups fed with control and T-2 and HT-2 toxin contaminated diets. Pathological signs of toxicity were investigated on days 21 and 39 of the trial, individual liveweight was measured weekly. Five birds from each group were sacrificed on the 21st and 39th days of treatment, when blood plasma, red blood cell, liver and kidney samples were taken, in which malondialdehyde and reduced glutathione concentration and glutathione-peroxidase activity were determined. Pathological signs (lesions in the oral cavity and on the tongue, inflammation in the small intestine) were found in the group fed T-2 and HT-2 toxin contaminated feed on day 21 compared to control. Body weight was significantly lower as a result of feeding T-2 and HT-2 toxin contaminated diet. However, the contamination did not cause a significant increase of malondialdehyde content in the analysed tissues. Reduced glutathione content was significantly lower in the liver homogenate on day 39 than that of the control. Glutathione peroxidase activity also did not differ significantly in blood plasma, red blood cell haemolysates and kidney homogenates, while it was significantly higher in the liver homogenates of the mycotoxin-challenged birds. In conclusion, it can be stated that T-2 and HT-2 toxin exposure has long-term effects in broiler chickens.

Development of a pig jejunal explant culture for studying the gastrointestinal toxicity of the mycotoxin deoxynivalenol: histopathological analysis

The digestive tract is a target for the mycotoxin deoxynivalenol (DON), a major cereals grain contaminant of public health concern in Europe and North America. Pig, the most sensitive species to DON toxicity, can be regarded as the most relevant animal model for studying the intestinal effects of DON. A pig jejunal explants culture was developed to assess short-term effects of DON. In a first step, jejunal explants from 9-13 week-old and from 4-5 week-old pigs were cultured in vitro for up to 8h. Explants from younger animals were better preserved after 8h, as assessed by morphological scores and by villi lengths. In a second step, DON dose-related alterations of the jejunal tissue were observed, including shortened and coalescent villi, lysis of enterocytes, oedema. After 4h of DON exposure of explants from 4-5 week-old pigs, a no-effect concentration level of 1 microM was estimated (corresponding to diet contaminated with 0.3mg DON/kg) based on morphological scores, and of 0.2 microM based on villi lengths. In conclusion, our data indicate that pig intestinal explants represent a relevant and sensitive model to investigate the effects of food contaminants.

Effects of a diet containing fusarium toxins on the fertility of gilts and on bulbourethral gland weight in barrows

Nine gilts weighing 80 kg at the beginning of the trial were fed a mycotoxin contaminated diet containing 2 mg deoxynivalenol (DON) and 0.4 mg zearalenone (ZON) per kg (Diet M). Their daily weight gain until 103 kg BW was reduced in comparison to the nine control animals fed an uncontaminated diet (Diet C) (763 vs. 912 g; p = 0.02). There was no treatment effect on the age at first observed oestrus. Seven and eight gilts receiving Diet M and C, respectively, became pregnant after being mated once or being again mated three weeks later. The examination of the uteri of gilts slaughtered 35-61 days after mating showed that the exposure to DON and ZON had no effect on the number of foetuses per gilt (p = 0.54), but increased their growth rate (p = 0.003). Thus, low dietary DON and ZON levels had no negative effects on the reproductive parameters examined. The hypothesis that the bulbourethral gland weight of barrows can be used for the bioassay of low dietary ZON levels was rejected since feeding Diet M from 80-103 kg BW did not increase the weight of that accessory sex gland (p = 0.51).

Effect of combined treatment with aflatoxin B1 and T-2 toxin and metabolites on some production traits and lipid peroxide status parameters of broiler chickens

Three groups of cockerels were fed with a control diet, with a diet contaminated with T-2 and HT-2 toxin (0.31 and 0.26 mg/kg) or with that containing a combination of T-2 and HT-2 toxin (0.32 and 0.25 mg/kg) and aflatoxin B1 (AFB1, 0.38 mg/kg) for 21 days. Body weight gain and feed conversion ratio did not differ significantly among the groups. Malondialdehyde concentration of the liver was lower in the group fed the diet contaminated with the combination of T-2 + HT-2 toxin and aflatoxin B1 as compared to the control group or the group fed T-2 + HT-2 toxins. Reduced glutathione (GSH) content of the liver was lower in the T-2 + HT-2 group than in the group fed a combination of T-2, HT-2 and aflatoxin. Reduced glutathione content of the heart was higher in the T-2 + HT-2 group than in the control group. Mycotoxin contamination had no effect on glutathione peroxidase (GSH-Px) activity in comparison to the control, but significantly lower GSH-Px activity was found in the heart of chickens in the T-2 + HT-2 + AFB1 group than in the T-2 + HT-2 group. In this study, T-2 + HT-2 toxin and aflatoxin B1 contamination of the diets did not affect the production traits adversely and did not exert additive effects on lipid peroxidation and on the glutathione redox system.

Trichothecenes in cereal grains

Trichothecenes are sesquiterpenoid mycotoxins associated with fusarium head blight (FHB) of cereals, with worldwide economic and health impacts. While various management strategies have been proposed to reduce the mycotoxin risk, breeding towards FHB-resistance appears to be the most effective means to manage the disease, and reduce trichothecene contamination of cereal-based food products. This review provides a brief summary of the trichothecene synthesis in Fusarium species, their toxicity in plants and humans, followed by the current methods of screening and breeding for resistance to FHB and trichothecene accumulation.

T-2 toxin-induced toxicity in pregnant mice and rats

T-2 toxin is a cytotoxic secondary fungal metabolite that belongs to the trichothecene mycotoxin family. This mycotoxin is a well known inhibitor of protein synthesis through its high binding affinity to peptidyl transferase, which is an integral part of the ribosomal 60s subunit, and it also inhibits the synthesis of DNA and RNA, probably secondary to the inhibition of protein synthesis. In addition, T-2 toxin is said to induce apoptosis in many types of cells bearing high proliferating activity. T-2 toxin readily passes the placenta and is distributed to embryo/fetal tissues, which include many component cells bearing high proliferating activity. This paper reviews the reported data related to T-2 toxin-induced maternal and fetal toxicities in pregnant mice and rats. The mechanisms of T-2 toxin-induced apoptosis in maternal and fetal tissues are also discussed in this paper.

Fumonisins, trichothecenes and zearalenone in cereals

Fumonisins are phytotoxic mycotoxins which are synthesized by various species of the fungal genus Fusarium such as Fusarium verticillioides (Sacc.) Nirenberg (ex F.moniliforme Sheldon) and Fusarium proliferatum. The trichothecene (TC) mycotoxins are secondary metabolites produce by species that belong to several fungal genera, especially Fusarium, Stachybotrys, Trichothecium, Trichoderma, Memnoniella and Myrothecium. Fusarium mycotoxins are widely dispersed in cereals and their products. Zearalenone (ZEA) is an estrogenic compound produced by Fusarium spp. such as F. graminearum and F. culmorum. Fumonisins, the TCs and ZEA are hazardous for human and animal health. Contamination with TCs causes a number of illnesses in human and animal such as decrease in food consumption (anorexia), depression or inhibition on immune system function and haematoxicity. The purpose of this paper is to give a review of the papers published on the field of fumonisin, TC and ZEA mycotoxins in cereals consumed in the world.

Immunomodulatory effects of feed-borne Fusarium mycotoxins in chickens infected with coccidia

The potential for Fusarium mycotoxins to modulate immunity was studied in chickens raised to 10 weeks of age using an enteric coccidial infection model. Experimental diets included: control, diets containing grains naturally contaminated with Fusarium mycotoxins, and diets containing contaminated grains + 0.2% polymeric glucomannan mycotoxin adsorbent (GMA). Contaminated diets contained up to 3.8 microg/g deoxynivalenol (DON), 0.3 microg/g 15-acetyl DON and 0.2 microg/g zearalenone. An optimized mixture (inducing lesions without mortality) of Eimeria acervulina, E. maxima and E. tenella was used to challenge birds at 8 weeks of age. Immune parameters were studied prior to challenge, at the end of the challenge period (7 days post-inoculation, PI), and at the end of the recovery period (14 days PI). Total serum immunoglobulin (Ig) A and IgG concentrations in challenged birds fed the contaminated diet were higher than controls at the end of the challenge period. Serum concentration of IgA, but not IgG, was significantly decreased at the end of the recovery period in birds fed the contaminated diet. The percentage of CD4+ and CD8+ cell populations in blood mononuclear cells decreased significantly at the end of the challenge period in birds fed the control or the contaminated diet compared to their percentages prior to challenge. The pre-challenge percentage of CD8+ population was restored at the end of the recovery period only in birds fed the control diet. Interferon-gamma (IFN-gamma) gene expression in caecal tonsils was up-regulated in challenged birds fed the contaminated diet at the end of the challenge period. No significant effect of diet was observed on oocyst counts despite the changes in the studied immune parameters. It was concluded that Fusarium mycotoxins modulate the avian immune system. This modulation involves alteration of gene expression but apparently does not enhance susceptibility or resistance to a primary coccidial challenge.

Reduction in fusarium toxin levels in corn silage with low dry matter and storage time

Under unfavorable climatic conditions, Fusarium spp. can contaminate corn plants in the field and produce toxins that are present at the time of ensiling. The stability of deoxynivalenol, fumonisins B1 and B2, and zearalenone in corn silage was tested over two consecutive years. Variables studied were corn dry matter (DM) and storage length and temperature. The concentration of all Fusarium toxins decreased upon ensiling ( P < 0.001). Increasing the length of storage and ensiling with low DM resulted in a higher rate of toxin disappearance, particularly for the water soluble toxins deoxynivalenol and fumonisin B1. Toxin disappearance ranged from 50% for zearalenone to 100% for deoxynivalenol. In contrast, temperature did not have any effect on stability ( P > 0.05). These results indicate that low DM at ensiling as well as a prolonged storage could be a practical way to reduce or eliminate some Fusarium toxins in contaminated silages.

T-2 Toxin: Incidence and Toxicity in Poultry

T-2 toxin is the most toxic type A trichothecene mycotoxin. It is the secondary metabolite of the Fusarium fungi, and is common in grain and animal feed. Toxic effects have been shown both in experimental animals and in livestock. It has been implicated in several outbreaks of human mycotoxicoses. Toxic effects in poultry include inhibition of protein, DNA, and RNA synthesis, cytotoxicity, immunomodulation, cell lesions in the digestive tract, organs and skin, neural disturbances and low performance in poultry production (decreased weight gain, egg production, and hatchability). Concentrations of T-2 toxin in feed are usually low, and its immunosuppressive effects and secondary infections often make diagnosis difficult. If at the onset of the disease, a change in diet leads to health and performance improvements in animals, this may point to mycotoxin poisoning. Regular control of grain and feed samples is a valuable preventive measure, and it is accurate only if representative samples are tested. This article reviews the incidence and toxic effects of T-2 toxin in poultry.

Screening of fermentative bacteria for their ability to bind and biotransform deoxynivalenol, zearalenone and fumonisins in an in vitro simulated corn silage model

Fermentative bacteria can potentially be utilized to detoxify corn silage contaminated by Fusarium toxins. The objective of the present study was to test a large number of these bacteria for their ability to bind and/or biotransform deoxynivalenol (DON), zearalenone (ZEN) and fumonisins B(1) and B(2) (FB(1), FB(2)) in conditions simulating corn silage. A total of 202 strains were screened in contaminated, pH 4, corn infusion inoculated with 5 x 10(8) CFU ml(-1). Eight Lactobacilli and three Leuconostoc biotransformed ZEN into alpha-zearalenol, but no biotransformation was detected for DON and fumonisins. In contrast, most strains were capable of binding Fusarium toxins. The most effective genera were Streptococcus and Enterococcus, capable of binding up to 33, 49, 24 and 62% of DON, ZEN, FB(1) and FB(2), respectively. The ability to bind Fusarium toxins seems to be a common property of fermentative bacteria and could help to decrease their toxicity in animals.

Dose-dependent effects of T-2 toxin on performance, lipid peroxidation, and genotoxicity in broiler chickens

The objective of the present study was to evaluate the effects of different concentrations of T-2 toxin in feed on performance, lipid peroxidation, and genotoxicity in vivo. For a 17-d period, T-2 toxin was added to the diet of the chickens. Fifty 22-d-old male broiler chickens were divided into 5 groups that were supplemented with different concentrations of T-2 toxin: control (0.0 mg/kg of feed), T 0.5 (0.5 mg/kg of feed), T 1.5 (1.5 mg/kg of feed), T 4.5 (4.5 mg/kg of feed), and T 13.5 (13.5 mg/kg of feed). Deoxyribonucleic acid fragmentation in spleen leukocytes, malondialdehyde in plasma and liver, total plasma antioxidative status, glutathione peroxidase activity, and total serum Ig (IgA and IgG) were measured. Feed consumption and BW gain decreased when the concentration of T-2 toxin was 4.5 and 13.5 mg/kg of feed. Compared with the control group, the rate of DNA damage increased significantly in the group fed 13.5 mg of T-2 toxin/kg of feed. In contrast to DNA fragmentation, indicators of oxidative stress did not show differences between groups fed T-2 toxin and the control. More serum IgA was detected in the group T 13.5 compared with the control, whereas there were no differences in serum IgG levels. The results of the present study indicate that impaired performance, DNA fragmentation in spleen leukocytes, and elevated serum IgA levels induced by T-2 toxin are dose-dependent. Based on our results, we could not confirm the hypothesis that oxidative stress is among the mechanisms by which T-2 toxin induces DNA fragmentation.