Effectiveness of mycotoxin sequestration activity of micronized wheat fibres on distribution of ochratoxin A in plasma, liver and kidney of piglets fed a naturally contaminated diet

In Vitro Digestion and Intestinal Absorption of Mycotoxins Due to Exposure from Breakfast Cereals: Implications for Children's Health

Breakfast cereals play a crucial role in children's diets, providing essential nutrients that are vital for their growth and development. Children are known to be more susceptible than adults to the harmful effects of food contaminants, with mycotoxins being a common concern in cereals. This study specifically investigated aflatoxin B1 (AFB1), enniatin B (ENNB), and sterigmatocystin (STG), three well-characterized mycotoxins found in cereals. The research aimed to address existing knowledge gaps by comprehensively evaluating the bioaccessibility and intestinal absorption of these three mycotoxins, both individually and in combination, when consumed with breakfast cereals and milk. The in vitro gastrointestinal method revealed patterns in the bioaccessibility of AFB1, ENNB, and STG. Overall, bioaccessibility increased as the food progressed from the stomach to the intestinal compartment, with the exception of ENNB, whose behavior differed depending on the type of milk. The ranking of overall bioaccessibility in different matrices was as follows: digested cereal > cereal with semi-skimmed milk > cereal with lactose-free milk > cereal with soy beverage. Bioaccessibility percentages varied considerably, ranging from 3.1% to 86.2% for AFB1, 1.5% to 59.3% for STG, and 0.6% to 98.2% for ENNB. Overall, the inclusion of milk in the ingested mixture had a greater impact on bioaccessibility compared to consuming the mycotoxins as a single compound or in combination. During intestinal transport, ENNB and STG exhibited the highest absorption rates when ingested together. This study highlights the importance of investigating the combined ingestion and transport of these mycotoxins to comprehensively assess their absorption and potential toxicity in humans, considering their frequent co-occurrence and the possibility of simultaneous exposure.

Risks for animal health related to the presence of ochratoxin A (OTA) in feed

In 2004, the EFSA Panel on Contaminants in the Food Chain (CONTAM) adopted a Scientific Opinion on the risks to animal health and transfer from feed to food of animal origin related to the presence of ochratoxin A (OTA) in feed. The European Commission requested EFSA to assess newly available scientific information and to update the 2004 Scientific Opinion. OTA is produced by several fungi of the genera Aspergillus and Penicillium. In most animal species it is rapidly and extensively absorbed in the gastro-intestinal tract, binds strongly to plasma albumins and is mainly detoxified to ochratoxin alpha (OTalpha) by ruminal microbiota. In pigs, OTA has been found mainly in liver and kidney. Transfer of OTA from feed to milk in ruminants and donkeys as well as to eggs from poultry is confirmed but low. Overall, OTA impairs function and structure of kidneys and liver, causes immunosuppression and affects the zootechnical performance (e.g. body weight gain, feed/gain ratio, etc.), with monogastric species being more susceptible than ruminants because of limited detoxification to OTalpha. The CONTAM Panel considered as reference point (RP) for adverse animal health effects: for pigs and rabbits 0.01 mg OTA/kg feed, for chickens for fattening and hens 0.03 mg OTA/kg feed. A total of 9,184 analytical results on OTA in feed, expressed in dry matter, were available. Dietary exposure was assessed using different scenarios based on either model diets or compound feed (complete feed or complementary feed plus forage). Risk characterisation was made for the animals for which an RP could be identified. The CONTAM Panel considers that the risk related to OTA in feed for adverse health effects for pigs, chickens for fattening, hens and rabbits is low.

Enzymatic degradation of ochratoxin A in the gastrointestinal tract of piglets

Animal feeds are often contaminated with ochratoxin A (OTA), a potent natural mycotoxin hazardous to animal and human health that accumulates in blood and tissues. To the best of our knowledge, this study is the first to investigate the in vivo application of an enzyme (OTA amidohydrolase; OAH) that degrades OTA into the nontoxic molecules phenylalanine and ochratoxin α (OTα) in the gastrointestinal tract (GIT) of pigs. Piglets were fed six experimental diets over 14 days, varying in OTA contamination level (50 or 500 μg/kg; OTA50 and OTA500) and presence of OAH; a negative control diet (no OTA added) and a diet containing OTα at 318 µg/kg (OTα318). The absorption of OTA and OTα into the systemic circulation (plasma and dried blood spots, DBS), their accumulation in kidney, liver, and muscle tissues, and excretion through feces and urine were assessed. The efficiency of OTA degradation in the digesta content of the GIT was also estimated. At the end of the trial, accumulation of OTA in blood was significantly higher in OTA groups (OTA50 and OTA500) in comparison to enzyme groups (OAH50 and OAH500, respectively). The supplementation of OAH explicitly reduced the absorption of OTA (P < 0.005) into plasma by 54% and 59% (from 40.53 ± 3.53 to 18.66 ± 2.28 ng/mL in piglets fed the 50 μg OTA/kg diets and from 413.50 ± 71.88 to 168.35 ± 41.02 ng/mL in piglets fed the 500 μg OTA/kg diets, respectively) and in DBS by 50% and 53% (from 22.79 ± 2.63 to 10.67 ± 1.93 ng/mL in piglets fed the 50 μg OTA/kg diets and from 232.85 ± 35.16 to 105.71 ± 24.18 ng/mL in piglets fed the 500 μg OTA/kg diets, respectively). The OTA concentrations in plasma were positively associated with the OTA levels detected in all tissues analyzed; adding OAH reduced OTA levels in the kidney, liver, and muscle (P < 0.005) by 52%, 67%, and 59%, respectively. The analysis of GIT digesta content showed that OAH supplementation led to OTA degradation in the proximal GIT where natural hydrolysis is inefficient. Overall, the data of present in vivo study demonstrated that supplementation of swine feeds with OAH successfully reduced OTA levels in blood (plasma and DBS) as well as in kidney, liver, and muscle tissues. Therefore, an approach to use enzymes as feed additives might be most promising to mitigate the harmful effects of OTA on the productivity and welfare of pigs and at the same time improving the safety of pig-derived food products.

Mycotoxins of Concern in Children and Infant Cereal Food at European Level: Incidence and Bioaccessibility

Cereals are of utmost importance for the nutrition of infants and children, as they provide important nutrients for their growth and development and, in addition, they are easily digestible, being the best choice for the transition from breast milk/infant formula to solid foods. It is well known that children are more susceptible than adults to toxic food contaminants, such as mycotoxins, common contaminants in cereals. Many mycotoxins are already regulated and controlled according to strict quality control standards in Europe and around the world. There are, however, some mycotoxins about which the level of knowledge is lower: the so-called emerging mycotoxins, which are not yet regulated. The current review summarizes the recent information (since 2014) published in the scientific literature on the amounts of mycotoxins in infants’ and children’s cereal-based food in Europe, as well as their behaviour during digestion (bioaccessibility). Additionally, analytical methods used for mycotoxin determination and in vitro methods used to evaluate bioaccessibility are also reported. Some studies demonstrated the co-occurrence of regulated and emerging mycotoxins in cereal products used in children’s food, which highlights the need to adopt guidelines on the simultaneous presence of more than one mycotoxin. Although very little research has been done on the bioaccessibility of mycotoxins in these food products, very interesting results correlating the fiber and lipid contents of such products with a higher or lower bioaccessibility of mycotoxins were reported. LC-MS/MS is the method of choice for the detection and quantification of mycotoxins due to its high sensibility and accuracy. In vitro static digestion models are the preferred ones for bioaccessibility evaluation due to their simplicity and accuracy.

Investigation of ochratoxin a in blood sausages in the Czech Republic: Comparison with data over Europe

Blood sausages consisting of groats, pork, porcine offal, fat, blood, and spices are very popular in the Czech Republic. All these ingredients are potential sources of dietary exposure to ochratoxin A (OTA). OTA has a strong affinity to serum proteins in porcine blood. Thus, the contamination of blood sausages with OTA can be expected. This study aims to evaluate OTA in 200 samples of porcine blood sausages purchased at the Czech market during 2020-2021. The analytical method high-performance liquid chromatography coupled with fluorescence detection with pre-treatment using immunoaffinity columns was employed to determine OTA. The limit of detection was 0.03 ng/g and the limit of quantification 0.10 ng/g. Recovery was 71.6 %. All samples were positive at contents ranging from 0.15 to 5.68 ng/g with a mean of 1.47 ng/g, and a median of 1.26 ng/g. A total of 66% of these samples contained OTA content exceeding the maximum limit of 1 ng/g set in Italy. This study demonstrates that the Czech population is exposed to OTA from blood sausages. The proposed preliminary action limit for OTA in blood sausages should be set at 1 ng/g. No regulatory limits for OTA in blood sausages have been established yet in the European Union legislation. To protect human health, further monitoring of OTA in these products is necessary.

Simultaneous Removal of Mycotoxins by a New Feed Additive Containing a Tri-Octahedral Smectite Mixed with Lignocellulose

Simultaneous removal of mycotoxins has been poorly addressed, and a limited number of studies have reported the efficacy of feed additives in sequestering a large spectrum of mycotoxins. In this study, a new mycotoxin-adsorbing agent was obtained by properly mixing a tri-octahedral smectite with a lignocellulose-based material. At a dosage of 1 mg mL⁻¹, these materials simultaneously adsorbed frequently occurring mycotoxins and did not exert a cytotoxic effect on intestinal cells. Chyme samples obtained by a simulated GI digestion did not affect the viability of Caco-2TC7 cells as measured by the MTT test. In addition, the chyme of the lignocellulose showed a high content of polyphenols (210 mg mL⁻¹ catechin equivalent) and good antioxidant activity. The properties of the individual constituents were maintained in the final composite, and were unaffected by their combination. When tested with a pool of seven mycotoxins at 1 µg mL⁻¹ each and pH 5, the composite (5 mg mL⁻¹) simultaneously sequestered AFB₁ (95%), FB₁ (99%), ZEA (93%), OTA (80%), T-2 (63%), and DON (22%). HT-2 adsorption did not occur. Mycotoxin adsorption increased exponentially as dosage increased, and occurred at physiological pH values. AFB₁, ZEA and T-2 adsorption was not affected by pH in the range 3–9, whereas OTA and FB₁ were adsorbed at pH values of 3–5. The adsorbed amount of AFB₁, ZEA and T-2 was not released when pH rose from 3 to 7. FB₁ and OTA desorption was less than 38%. Langmuir adsorption isotherms revealed high capacity and affinity for adsorption of the target mycotoxins. Results of this study are promising and show the potential of the new composite to remove mycotoxins in practical scenarios where several mycotoxins can co-occur.

Removal of Aflatoxins Using Agro-Waste-Based Materials and Current Characterization Techniques Used for Biosorption Assessment

Aflatoxins are the most hazardous fungal-generated secondary metabolites produced by toxigenic Aspergillus species. These toxins are frequently detected in food and feed and impose either acute or chronic effects in humans and animals, causing great public concern. Because of the adverse effects of aflatoxins, many physical, chemical, and biological decontamination approaches have been developed. However, the most commonly used procedure is the addition of adsorbent materials into aflatoxin-contaminated diets to reduce toxin absorption and distribution to blood and target organs. In recent times, sorption technology with agro-waste-based materials has appeared as a promising alternative over conventional binding agents with the benefits of low cost, higher rentability, feasibility, and exceptional efficiencies. This review is mainly focused on discussing the most important agro-waste-based materials able to adsorb aflatoxins such as pomaces, seeds, stems, hulls, peels, leaves, berries, lignins, fibers, weeds, and various horticultural byproducts. Further data of the in vitro, in vivo, and in silico efficacy of these biomaterials to adsorb and then desorb aflatoxins are given. Besides, an overview of the main characterization techniques used to elucidate the most important physical and chemical mechanisms involved in the biosorption is presented. Finally, conclusions and future research necessities are also outlined.

Deoxynivalenol: Mechanisms of action and its effects on various terrestrial and aquatic species

Deoxynivalenol, a type B trichothecene mycotoxin produced by Fusarium species of fungi, is a ubiquitious contaminant of cereal grains worldwide. Chronic, low dose consumption of feeds contaminated with DON is associated with a wide range of symptoms in terrestrial and aquatic species including decreased feed intake and feed refusal, reduced weight gain, and altered nutritional efficiency. Acute, high dose exposure to DON may be associated with more severe symptoms such as vomiting, diarrhea, intestinal inflammation and gastrointestinal hemorrhage. The toxicity of DON is partly related to its ability to disrupt eukaryotic protein synthesis via binding to the peptidyl transferase site of the ribosome. Moreover, DON exerts its effects at the cellular level by activating mitogen activated protein kinases (MAPK) through a process known as the ribotoxic stress response (RSR). The outcome of DON-associated MAPK activation is dose and duration dependent; acute low dose exposure results in immunostimulation characterized by the upregulation of cytokines, chemokines and other proinflammatory-related proteins, whereas longer term exposure to higher doses generally results in apoptosis, cell cycle arrest, and immunosuppression. The order of decreasing sensitivity to DON is considered to be: swine > rats > mice > poultry ≈ ruminants. However, studies conducted within the past 10 years have demonstrated that some species of fish, such as rainbow trout, are highly sensitive to DON. The aims of this review are to explore the effects of DON on terrestrial and aquatic species as well as its mechanisms of action, metabolism, and interaction with other Fusarium mycotoxins. Notably, a considerable emphasis is placed on reviewing the effects of DON on different species of fish.

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.

Efficient Adsorption of Deoxynivalenol by Porous Carbon Prepared from Soybean Dreg

A novel porous carbon adsorbent for the removal of deoxynivalenol was prepared from soybean dreg (SD). The new material was characterized by scanning electron microscopy equipped with energy dispersive X-ray spectroscopy (SEM-EDS), transmission electron microscopy (TEM), Brunauer-Emmett-Teller (BET) analysis, N2 adsorption/desorption measurement techniques, X-ray diffraction (XRD), Raman spectroscopy, Fourier transform infrared (FTIR) spectroscopy and X-ray photoelectron spectroscopy (XPS). The specific surface area of the SDB-6-KOH was found to be 3655.95 m2 g-1, the pore volume was 1.936 cm3 g-1 and the average pore size was 2.125 nm. The high specific surface area and effective functional groups of the carbon material promoted the adsorption of deoxynivalenol. By comparing the adsorption effect of SDB-6-X prepared with different activators (X: KOH, K2CO3, KHCO3), SDB-6-KOH had the highest adsorption capacity. The maximum adsorption capacity of SDB-6-KOH to deoxynivalenol was 52.9877 µg mg-1, and the removal efficiency reached 88.31% at 318 K. The adsorption kinetic and isotherm data were suitable for pseudo-second-order and Langmuir equations, and the results of this study show that the novel carbon material has excellent adsorptive ability and, thus, offers effective practical application potential for the removal of deoxynivalenol.

Physical and Chemical Methods for Reduction in Aflatoxin Content of Feed and Food

Aflatoxins (AFs) are among the most harmful fungal secondary metabolites imposing serious health risks on both household animals and humans. The more frequent occurrence of aflatoxins in the feed and food chain is clearly foreseeable as a consequence of the extreme weather conditions recorded most recently worldwide. Furthermore, production parameters, such as unadjusted variety use and improper cultural practices, can also increase the incidence of contamination. In current aflatoxin control measures, emphasis is put on prevention including a plethora of pre-harvest methods, introduced to control Aspergillus infestations and to avoid the deleterious effects of aflatoxins on public health. Nevertheless, the continuous evaluation and improvement of post-harvest methods to combat these hazardous secondary metabolites are also required. Already in-use and emerging physical methods, such as pulsed electric fields and other nonthermal treatments as well as interventions with chemical agents such as acids, enzymes, gases, and absorbents in animal husbandry have been demonstrated as effective in reducing mycotoxins in feed and food. Although most of them have no disadvantageous effect either on nutritional properties or food safety, further research is needed to ensure the expected efficacy. Nevertheless, we can envisage the rapid spread of these easy-to-use, cost-effective, and safe post-harvest tools during storage and food processing.

Relationship between Mycotoxin Content in Winter Wheat Grain and Aspirated Dust Collected during Harvest and after Storage

A total of 323 paired grain and grain dust samples (particle size <1650 μm) were collected from combines at harvest (56%), on-farm bins (28%), and experimental minibins seeded with an ochratoxin A (OTA)/Penicillium verrucosum hot spots (15%) of which >98% were soft red winter wheat. Liquid chromatography-tandem mass spectrometry (LC-MS/MS) was used to detect 21 mycotoxins, including deoxynivalenol (DON) and its plant-conjugated form, deoxynivalenol 3-β-d-glucoside (DON 3-Glc). Except for DON 3-Glc, all mycotoxin concentrations found in grain dust were higher than in grain (p < 0.0030). Pearson correlation coefficients and two-variable regression show a significant (p < 0.0001) linear relationship between the mycotoxin content in grain and that in grain dust with 19 toxins. In only five mycotoxins (DON, OTA, ochratoxin B, citrinin, and enniatin A₁), more than 82% of the variation in the data is explained by the two-variable regression model. Because of its higher mean concentration and detection frequency, only DON produced a strong relationship (p < 0.0001, r ² = 0.949) with low root-mean-square error (RMSE) (293.41 ng/g). The results suggest that modeling levels in grain based upon levels in grain dust can be used to estimate DON in grain bulk.

Ochratoxin A: Carryover from animal feed into livestock and the mitigation strategies

This review aims to highlight the effects of ochratoxin A (OTA) in the feed of meat-producing animals. The accumulation of OTA in feed and its distribution in various farm animals were compared and evaluated. Primarily, the oral administration of OTA-contaminated feed and the predisposition in an animal's vital organ were critically examined in this work. The collated reports show that OTA directly associated with endemic nephropathy and its high concentration leads to degeneration of liver cells, and necrosis of intestinal and lymphoid tissues. At present, limited reports are available in the recent literature on the problems and consequences of OTA in feed. Therefore, this review focused on the OTA carryover from feed to farm animals and the interaction of its secondary metabolites on their biochemical parameters. Hence, this report provides greater insights into animal health related to OTA residues in meat and meat products. This article also explores mitigation strategies that can be used to prevent the carryover effects of OTA in livestock feeds and the effects in the food chain.

A Study of Carry-Over and Histopathological Effects after Chronic Dietary Intake of Citrinin in Pigs, Broiler Chickens and Laying Hens

Citrinin (CIT) is a polyketide mycotoxin occurring in a variety of food and feedstuff, among which cereal grains are the most important contaminated source. Pigs and poultry are important livestock animals frequently exposed to mycotoxins, including CIT. Concerns are rising related to the toxic, and especially the potential nephrotoxic, properties of CIT. The purpose of this study was to clarify the histopathological effects on kidneys, liver, jejunum and duodenum of pigs, broiler chickens and laying hens receiving CIT contaminated feed. During 3 weeks, pigs (n = 16) were exposed to feed containing 1 mg CIT/kg feed or to control feed (n = 4), while 2 groups of broiler chickens and laying hens (n = 8 per group) received 0.1 mg CIT/kg feed (lower dose group) and 3 or 3.5 mg CIT/kg feed (higher dose group), respectively, or control feed (n = 4). CIT concentrations were quantified in plasma, kidneys, liver, muscle and eggs using a validated ultra-high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) method. Kidneys, liver, duodenum and jejunum were evaluated histologically using light microscopy, while the kidneys were further examined using transmission electron microscopy (TEM). Histopathology did not reveal major abnormalities at the given contamination levels. However, a significant increase of swollen and degenerated mitochondria in renal cortical cells from all test groups were observed (p < 0.05). These observations could be related to oxidative stress, which is the major mechanism of CIT toxicity. Residues of CIT were detected in all collected tissues, except for muscle and egg white from layers in the lowest dose group, and egg white from layers in the highest dose group. CIT concentrations in plasma ranged between 0.1 (laying hens in lower dose group) and 20.8 ng/mL (pigs). In tissues, CIT concentrations ranged from 0.6 (muscle) to 20.3 µg/kg (liver) in pigs, while concentrations in chickens ranged from 0.1 (muscle) to 70.2 µg/kg (liver). Carry-over ratios from feed to edible tissues were between 0.1 and 2% in pigs, and between 0.1 and 6.9% in chickens, suggesting a low contribution of pig and poultry tissue-derived products towards the total dietary CIT intake for humans.

Ochratoxin A induces liver inflammation: involvement of intestinal microbiota

BACKGROUND

Ochratoxin A (OTA) is a widespread mycotoxin and induces liver inflammation to human and various species of animals. The intestinal microbiota has critical importance in liver inflammation; however, it remains to know whether intestinal microbiota mediates the liver inflammation induced by OTA. Here, we treated ducklings with oral gavage of OTA (235 μg/kg body weight) for 2 weeks. Then, the microbiota in the cecum and liver were analyzed with 16S rRNA sequencing, and the inflammation in the liver was analyzed. To explore the role of intestinal microbiota in OTA-induced liver inflammation, intestinal microbiota was cleared with antibiotics and fecal microbiota transplantation was conducted.

RESULTS

Here, we find that OTA treatment in ducks altered the intestinal microbiota composition and structure [e.g., increasing the relative abundance of lipopolysaccharides (LPS)-producing Bacteroides], and induced the accumulation of LPS and inflammation in the liver. Intriguingly, in antibiotic-treated ducks, OTA failed to induce these alterations in the liver. Notably, with the fecal microbiota transplantation (FMT) program, in which ducks were colonized with intestinal microbiota from control or OTA-treated ducks, we elucidated the involvement of intestinal microbiota, especially Bacteroides, in liver inflammation induced by OTA.

CONCLUSIONS

These results highlight the role of gut microbiota in OTA-induced liver inflammation and open a new window for novel preventative or therapeutic intervention for mycotoxicosis.

Decontamination of Mycotoxin-Contaminated Feedstuffs and Compound Feed

Mycotoxins are known worldwide as fungus-produced toxins that adulterate a wide heterogeneity of raw feed ingredients and final products. Consumption of mycotoxins-contaminated feed causes a plethora of harmful responses from acute toxicity to many persistent health disorders with lethal outcomes; such as mycotoxicosis when ingested by animals. Therefore, the main task for feed producers is to minimize the concentration of mycotoxin by applying different strategies aimed at minimizing the risk of mycotoxin effects on animals and human health. Once mycotoxins enter the production chain it is hard to eliminate or inactivate them. This paper examines the most recent findings on different processes and strategies for the reduction of toxicity of mycotoxins in animals. The review gives detailed information about the decontamination approaches to mitigate mycotoxin contamination of feedstuffs and compound feed, which could be implemented in practice.

Comparative efficacy of agricultural by-products in sequestering mycotoxins

BACKGROUND

Biosorption using agricultural by-products has been proven as a low-cost and safe way to sequester mycotoxins. Few agricultural by-products have been studied for their efficacy in adsorbing simultaneously a large range of mycotoxins. The present work compared the ability of 51 agricultural by-products to adsorb mycotoxins from liquid mediums simulating physiological pH values, and it studied the mechanism for mycotoxin adsorption by isotherm adsorption experiments.

RESULTS

Grape pomaces, artichoke wastes, and almond hulls were selected as promising biosorbents for mycotoxins, being quite effective towards aflatoxin B₁ (AFB₁ ), zearalenone (ZEA), and ochratoxin A (OTA). Their adsorption was not affected by medium pH, and the adsorbed fraction was not released when pH rose from acid to neutral values. Fumonisin B₁ (FB₁ ) was adsorbed to a lesser extent, and deoxynivalenol adsorption was not recorded. For the selected biosorbents, maximum adsorption capacity calculated by the best fitting model (Freundlich, Langmuir, or Sips equation) ranged from 1.2 to 2.9 µg mg^-1 for AFB₁ , 1.3 to 2.7 µg mg^-1 for ZEA, 0.03 from 2.9 µg mg^-1 for OTA, and 0.01-1.1 µg mg^-1 for FB₁ .

CONCLUSION

This study confirms that some agricultural by-products can find technological applications as feed/food additives for mycotoxin reduction. © 2018 Society of Chemical Industry.

A review of the mycotoxin adsorbing agents, with an emphasis on their multi-binding capacity, for animal feed decontamination

Contamination of animal feed with mycotoxins still occurs very often, despite great efforts in preventing it. Animal feeds are contaminated, at low levels, with several mycotoxins, particularly with those produced by Aspergillus and Fusarium genera (Aflatoxin B_1, Ochratoxin A, Zearalenone, Deoxynivalenol and Fumonisina B₁). In animal feed, to date, only Aflatoxin B₁ is limited through EU regulation. Consequently, mycotoxins cause serious disorders and diseases in farm animals. In 2009, the European Union (386/2009/EC) approved the use of mycotoxin-detoxifying agents, as feed additives, to prevent mycotoxicoses in farm animals. The present review gives an overview of the problem of multi-mycotoxin contamination of feed, and aims to classify mycotoxin adsorbing agents (minerals, organic, and synthetic) for feed decontamination, focusing on adsorbents with the ability to bind to multiple mycotoxins, which should have a more effective application in farms but they are still little studied in scientific literature.

Occurrence of Ochratoxin a in Animal Tissues and Feeds in Poland in 2014-2016

Introduction

Ochratoxin A (OTA) is a toxic metabolite mainly produced by Aspergillus spp. and Penicillum spp. fungi. Research on the contamination of cereals, complete feeds, and tissues with this mycotoxin has indicated that it can be a toxicological problem impacting animal health and food safety in temperate climes. OTA contamination mainly besets the global pig industry, necessitating the monitoring of feeds and animal tissues. The aim of the study was to present the results of the official monitoring of OTA in animal tissues and feeds in Poland in 2014–2016 and determine the possible correlation between the presence of OTA in different types of samples.

Material and Methods

The presence of ochratoxin A was determined using accepted procedures based on liquid chromatography with fluorescence detection after immunoaffinity column clean-up. Determination of OTA was afforded in the range of 0.3 µg/kg to 300 µg/kg in complete feeds and from 0.2 µg/kg to 150 µg/kg in the kidneys, liver, and muscles.

Results

Over the three year span, about 23.5% of the animal tissues samples were contaminated by ochratoxin A. In the 2014 survey, 10% of the sample tissues contained 5–10 µg/kg (only one sample above 10 μg/kg), and in 2015 and 2016, 24% of samples showed levels above the limit of quantification 0.2 μg/kg, while none of the samples exceeded the established provisional action level of 5 μg/kg for animal tissues. The animal feed analysis showed that 9% was contaminated with ochratoxin A above the limit of quantification of 0.3μg/kg. In 2% of feed samples the OTA concentration was greater than 50 μg/kg.

Conclusion

The results confirm the appropriacy of OTA contamination monitoring and help to increase food safety.

Tissue distribution of ochratoxin A in pigs after administration of two-levels contaminated diets

The aim of the present study was to determine the levels of ochratoxin A (OTA) in pigs experimentally exposed to this mycotoxin and to evaluate if bile may be used to assess exposure to OTA. Twelve hybrid pigs were divided into 3 equal groups, a control group D0, and 2 experimental groups, D1 fed with 50 µg OTA/kg diet, and D2 fed with 500 µg OTA/kg diet for 15 days. At the end of the test, the animals were euthanized and samples of different tissues and biological fluids were analysed by HPLC-fluorescence detection for the presence of OTA. Samples of unconventional edible tissues such as lung and heart were also taken for analysis because they are used in typical Italian regional dishes. The Italian guidance value for OTA of 1 µg/kg established for pork meat and derived products has been exceeded in all the matrices from both the experimental groups. The comparison between OTA levels detected in D1 and D2 groups showed clearly a linear dose-response relationship. Based on the mean values measured, OTA distribution follows the order blood plasma > lung > kidney (in D1 group), heart (in D2 group) > heart (in D1 group), kidney (in D2 group) > bile > liver > fat > muscle. Analysis of bile can be useful for the detection of OTA in pigs. However, since blood can easily be taken from pigs, and given the correlation between the mycotoxin concentration detected in this matrix and the concentrations detected in the others, OTA level in blood is a more viable approach to assessing the presence of OTA in edible tissues. As lung and heart may contain high concentrations of OTA, the analytical controls should also include these matrices.

Grape Pomace, an Agricultural Byproduct Reducing Mycotoxin Absorption: In Vivo Assessment in Pig Using Urinary Biomarkers

The efficacy of four agricultural byproducts (ABPs) and two commercial binders (CBs) to reduce the gastrointestinal absorption of a mixture of mycotoxins was tested in piglets using urinary mycotoxin biomarkers as indicator of the absorbed mycotoxins. Twenty-eight piglets were administered a bolus contaminated with the mycotoxin mixture containing or not ABP or CB. Twenty-four hour urine was collected and analyzed for mycotoxin biomarkers by using a multiantibody immunoaffinity-based LC-MS/MS method. Each bolus contained 769 μg of fumonisin B1 (FB1), 275 μg of deoxynivalenol (DON), 29 μg of zearalenone (ZEN), 6.5 μg of aflatoxin B1 (AFB1) and 6.6 μg of ochratoxin A (OTA) corresponding to 2.2, 0.8, 0.08, 0.02, and 0.02 μg/g in the daily diet, respectively. The percentage of ABP in each bolus was 50%, whereas for the two CBs the percentages were 5.2 and 17%, corresponding to 2.8, 0.3, and 0.9% in the daily diet, respectively. The reduction of mycotoxin absorption was up to 69 and 54% for ABPs and CBs, respectively. White grape pomace of Malvasia was the most effective material as it reduced significantly (p < 0.05) urinary mycotoxin biomarker of AFB1 (67%) and ZEN (69%), whereas reductions statistically not significant were observed for FB1 (57%), DON (40%), and OTA (27%). This study demonstrates that grape pomace reduces the gastrointestinal absorption of mycotoxins. This agricultural byproduct can be considered an alternative to commercial products and used in the feed industries as an effective, cheap, and natural binder for multiple mycotoxins.

A review of the efficacy of mycotoxin detoxifying agents used in feed in light of changing global environment and legislation

In the recent years, mycotoxins have undoubtedly gained a keen interest of the scientific community studying food safety. The main reason is their profound impact on both human and animal health. International surveys reveal a low percentage of feed samples being contaminated above permitted/guideline levels, developed to protect consumers of animal derived products. However, the deleterious impact of feed co-contaminated at low levels with numerous both known and regulated as well as novel mycotoxins on producing animals has been described. Associated effects on agro-economics world-wide include substantial pecuniary losses which are borne by the society as a whole. Even though good agronomic practice is thought to be the most effective way of preventing animal feed contamination, the EC have recognised the need to introduce an additional means of management of feed already contaminated with low-levels of mycotoxins to alleviate detrimental effects on agricultural production efficiency. This review discusses types of feed detoxifying agents described in scientific literature, their reported efficacy in both in vitro and in vivo systems, and comparison with available commercial formulations in the light of increasing knowledge regarding mycotoxin prevalence in the changing global environment.

Occurrence, prevention and remediation of toxigenic fungi and mycotoxins in silage: a review

Ruminants are considered to be less sensitive towards mycotoxins than monogastric animals because rumen microbiota have mycotoxin-detoxifying capacities. Therefore the effect of mycotoxins towards ruminants has been studied to a lesser extent compared with monogastric animals. Worldwide, a high proportion of the ruminant diet consists of silages made of forage crops (i.e. all parts of the crop above the stubble are harvested). In practice, silages are often contaminated with multiple mycotoxins. Exposure to a cocktail of mycotoxins can hamper animal production and have severe health consequences. In this article the different aspects associated with mycotoxin contamination of silage are reviewed 'from seed to feed'. An overview is given on the occurrence of toxigenic fungal species and their concomitant mycotoxins in forage crops before and after ensiling. The mycotoxin load of visually non-mouldy samples and mouldy hot spots within the same silo is also compared. Subsequently, this review delves into different problem-solving strategies. A logical first step is prevention of mould growth and mycotoxin production in the field, during harvest and during ensiling. If prevention should fail, several remediation strategies are available. These are listed, mainly focusing on the possibilities of microbial degradation of mycotoxins in vivo in silage. © 2015 Society of Chemical Industry.

Contribution of organ vasculature in rat renal analysis for ochratoxin a: relevance to toxicology of nephrotoxins

Assumptions surrounding the kidney as a target for accumulation of ochratoxin A (OTA) are addressed because the contribution of the toxin in blood seems invariably to have been ignored. Adult rats were maintained for several weeks on toxin-contaminated feed. Using standard perfusion techniques, animals were anaesthetised, a blood sample was taken, one kidney was ligated, and the other kidney perfused with physiological saline in situ under normal blood pressure. Comparative analysis of OTA in pairs of kidneys showed marked reduction in the perfused organ in the range 37%-98% (mean 75%), demonstrating the general efficiency of perfusion supported also by histology, and implying a major role of blood in the total OTA content of kidney. Translation of OTA values in plasma to whole blood, and its predicted contribution as a 25% vascular compartment in kidney gave values similar to those in non-perfused kidneys. Thus, apparent 'accumulation' of OTA in kidney is due to binding to plasma proteins and long half-life in plasma. Attention should be re-focused on whole animal pharmacokinetics during chronic OTA exposure. Similar principles may be applied to DNA-OTA adducts which are now recognised as occurring in blood; application could also extend to other nephrotoxins such as aristolochic acid. Thus, at least, quantitative reassessment in urological tissues seems necessary in attributing adducts specifically as markers of potentially-tumourigenic exposure.

Feeding a diet contaminated with ochratoxin A for broiler chickens at the maximum level recommended by the EU for poultry feeds (0.1 mg/kg). 2. Effects on meat quality, oxidative stress, residues and histological traits

The European Commission Recommendation 2006/576/EC indicates that the maximum tolerable level of ochratoxin A (OTA) in poultry feeds is 0.1 mg OTA/kg. Thirty-six 1-day-old male broiler chicks were divided into two groups, a control (basal diet) and an OTA (basal diet + 0.1 mg OTA/kg) group. The OTA concentration was quantified in serum, liver, kidney, breast and thigh samples. The thiobarbituric acid reactive substances (TBARS) content were evaluated in the liver, kidney, breast and thigh samples. The glutathione (GSH) content, and catalase (CAT) and superoxide dismutase (SOD) activity were measured in the liver and kidney samples. Histopathological traits were evaluated for the spleen, bursa of Fabricius and liver samples. Moreover, the chemical composition of the meat was analysed in breast and thigh samples. In the OTA diet-fed animals, a serum OTA concentration of 1.15 ± 0.35 ng/ml was found, and OTA was also detected in kidney and liver at 3.58 ± 0.85 ng OTA/g f.w. and 1.92 ± 0.21 ng OTA/g f.w., respectively. The TBARS content was higher in the kidney of the ochratoxin A group (1.53 ± 0.18 nmol/mg protein vs. 0.91 ± 0.25 nmol/mg protein). Feeding OTA at 0.1 mg OTA/kg also resulted in degenerative lesions in the spleen, bursa of Fabricius and liver. The maximum tolerable level of 0.1 mg OTA/kg, established for poultry feeds by the EU, represents a safe limit for the final consumer, because no OTA residues were found in breast and thigh meat. Even though no clinical signs were noticed in the birds fed the OTA-contaminated diet, moderate histological lesions were observed in the liver, spleen and bursa of Fabricius.

Determination of ochratoxin A in serum and urine of pigs

The objective of the study was to determine ochratoxin A (OTA) concentrations in serum and urine of pigs during 30-day OTA treatment. OTA was administered orally to the experimental group (n=5) at a dose of 0.78 mg per animal per day, whereas control animals (n=5) were left untreated. OTA concentrations were determined using a validated enzyme-linked immunosorbent assay (ELISA). Method validation resulted in mean recoveries of 93-101% for serum and 98-106% for urine, with acceptable mean inter- and intraday relative standard deviations (<8% for urine and <7% for serum). The ELISA method can be effectively used as a simple screening method to determine OTA exposure in pigs during fattening. The maximum mean OTA concentration in serum was recorded on day 22 (8.75±2.93 ng/ml) and in urine on day 20 (43.56±35.76 ng/ml), indicating significant differences in OTA concentrations between these two matrices.

Ochratoxin a and mitotic disruption: mode of action analysis of renal tumor formation by ochratoxin A

The mycotoxin and food contaminant ochratoxin A (OTA) is a potent renal carcinogen in rodents, but its mode of action (MoA) is still poorly defined. In 2006, the European Food Safety Authority concluded that there is a "lack of evidence for the existence of OTA-DNA adducts" and thus insufficient evidence to establish DNA reactivity as a MoA for tumor formation by OTA. In reviewing the available database on OTA toxicity, a MoA for renal carcinogenicity of OTA is developed that involves a combination of genetic instability and increased proliferative drive as consequences of OTA-mediated disruption of mitosis, whereby the organ- and site-specificity of tumor formation by OTA is determined by selective renal uptake of OTA into the proximal tubule epithelium. The proposed MoA is critically assessed with respect to concordance of dose-response of the suggested key events and tumor formation, their temporal association, consistency, and biological plausibility. Uncertainties, data gaps and needs for further research are highlighted.

Substances for reduction of the contamination of feed by mycotoxins: a review

The global occurrence of mycotoxins is considered to be a major risk factor for human and animal health. Contamination of different agricultural commodities with mycotoxins still occurs despite the most strenuous prevention efforts. As a result, mycotoxin contaminated feed can cause serious disorders and diseases in farm animals. A number of approaches, such as physical and chemical detoxification procedures, have been used to counteract mycotoxins. However, only a few of them have practical application. A recent and promising approach to protect animals against the harmful effects of mycotoxin contaminated feed is the use of substances for reduction of the contamination of feed by mycotoxins. These substances, so-called mycotoxin binders (MB), are added to the diet in order to reduce the absorption of mycotoxins from the gastrointestinal tract and their distribution to blood and target organs, thus preventing or reducing mycotoxicosis in livestock. Recently, the use of such substances as technological feed additives has been officially allowed in the European Union. The efficacy of MB appears to depend on the properties of both the binder and the mycotoxin. Depending on their mode of action, these feed additives may act either by binding mycotoxins to their surface (adsorption), or by degrading or transforming them into less toxic metabolites (biotransformation). Biotransformation can be achieved by mycotoxin-degrading enzymes or by microorganisms producing such enzymes. Various inorganic adsorbents, such as hydrated sodium calcium aluminosilicate, zeolites, bentonites, clays, and activated carbons, have been tested and used as MB. An interesting alternative to inorganic adsorbents for the detoxification of mycotoxins is the use of organic binders, such as yeast cell wall components, synthetic polymers (cholestyramine, polyvinylpyrrolidone), humic substances and dietary fibres. This paper gives an overview of the current knowledge and situation in the field of MB. The most important types of MB, mechanism of their action, and their application as a part of general strategy to counteract mycotoxins are described in this review. Recent advances in the use and study of MB, as well as data of their in vitro and in vivo effectiveness are given. Problems, potential, current trends and perspectives associated with the use of MB are discussed as well in the review.

Effects of ochratoxin a on livestock production

Ochratoxin A (OTA) contamination often causes large economic losses on livestock production. The intake of feed contaminated by OTA also represents a potential risk for animal health and a food safety issue due to the transfer of the toxin through the food chain to humans. The aim of this paper is to review the available literature on: (1) the frequency and degree of occurrence of OTA in different feedstuffs; (2) the toxicological effects of OTA intake on the performance of the main livestock (i.e., poultry, swine, cattle, goats and sheep); and (3) the transfer of OTA, or its metabolites, from animal feed into animal products such as milk, meat and eggs.

Chemical, physical and biological approaches to prevent ochratoxin induced toxicoses in humans and animals

Ochratoxins are polyketide derived fungal secondary metabolites with nephrotoxic, immunosuppressive, teratogenic, and carcinogenic properties. Ochratoxin-producing fungi may contaminate agricultural products in the field (preharvest spoilage), during storage (postharvest spoilage), or during processing. Ochratoxin contamination of foods and feeds poses a serious health hazard to animals and humans. Several strategies have been investigated for lowering the ochratoxin content in agricultural products. These strategies can be classified into three main categories: prevention of ochratoxin contamination, decontamination or detoxification of foods contaminated with ochratoxins, and inhibition of the absorption of consumed ochratoxins in the gastrointestinal tract. This paper gives an overview of the strategies that are promising with regard to lowering the ochratoxin burden of animals and humans.

Developments in mycotoxin analysis: an update for 2008-2009

This review highlights developments in mycotoxin analysis and sampling over a period between mid-2008 and mid-2009. It covers the major mycotoxins: aflatoxins, alternaria toxins, cyclopiazonic acid, fumonisins, ochratoxin, patulin, trichothecenes and zearalenone. Developments in mycotoxin analysis continue, with emphasis on novel immunological methods and further description of LC-MS and LC-MS/MS, particularly as multimycotoxin applications for different ranges of mycotoxins. Although falling outside the main emphasis of the review, some aspects of natural occurrence have been mentioned, especially if linked to novel method developments.