The Fusarium toxins deoxynivalenol (DON) and zearalenone (ZON) in animal feeding

The contamination of cereal grains with toxic secondary metabolites of fungi, mycotoxins, is a permanent challenge in animal nutrition as health and performance of the animals may be compromised as well as the quality of animal derived food. Therefore the present article reviews the issue of mycotoxins in animal nutrition. As the Fusarium toxins deoxynivalenol (DON) and zearalenone (ZON) are of particular importance under the production conditions in central Europe and Germany, with respect to their frequent occurrence in toxicologically relevant concentrations, special emphasis is layed on those mycotoxins. The effects of DON and ZON on susceptible animals as well as management strategies to cope with the contamination of grain with those toxins are reviewed.     

Mycotoxins in foods and feeds in the United States.

Mycotoxins are considered unavoidable contaminants in foods and feeds because agronomic technology has not yet advanced to the stage at which preharvest infection of susceptible crops by fungi can be eliminated. The aflatoxins have received greater attention than any of the other mycotoxins because of their demonstrated carcinogenic effects in susceptible animals and their acute toxic effects in humans. Since 1965, the U.S. Food and Drug Administration (FDA) has enforced regulatory limits on the concentrations of these toxins in foods and feeds involved in interstate commerce. The FDA routinely monitors the food and feed industries through compliance programs to ensure that the levels of exposure to these toxins are kept as low as practical. This report summarizes data generated from compliance programs on aflatoxins for the fiscal years 1989, 1990, and the first half of 1991. Commodities sampled included peanuts and peanut products, tree nuts, corn and corn products, cottonseed, and milk. Higher than usual levels of contamination were found in corn examined from all areas of the United States in 1989 as a result of the severe drought that affected the 1988 corn crop. The drought in parts of the South and Southeast in 1990 resulted in increased contamination in corn and peanuts from those areas. A review of the surveillance data obtained on deoxynivalenol, zearalenone, ochratoxin A, sterigmatocystin, penicillic acid, and patulin over the years along with available toxicological data for these mycotoxins indicated that no regulatory actions were warranted. The lack of sufficient surveillance data on other mycotoxins that occur in the United States can be attributed in part to the unavailability of reliable analytical methodology.     

Implications of mycotoxins in animal disease

Mycotoxins are formed on animal feeds when conditions of moisture and temperature permit the growth of naturally occurring toxigenic fungi. In general, mycotoxins are low molecular weight, nonantigenic substances, many of which are relatively heat stable. Mycotoxins can cause acute disease episodes when animals consume critical quantities of them. Specific toxins affect specific organs or tissues such as the liver, kidney, oral and gastric mucosa, brain, or reproductive tract. In acute mycotoxicoses, the signs of disease often are marked and directly referable to the affected target organs. Most frequently, however, concentrations of mycotoxin in feeds are below those that cause acute disease. At lower concentrations, the effects of mycotoxins are more protean. They reduce the growth rate of young animals, and some interfere with native mechanisms of resistance and impair immunologic responsiveness, making the animals more susceptible to infection. These effects on immunity and resistance are difficult to recognize because the signs of disease are associated with the infection rather than with the mycotoxin that predisposed the animal to infection. Animals vary in their susceptibility to some mycotoxins, according to the species and age of animal; young growing animals are more susceptible to certain mycotoxins than are adults. The major effects, sources, and dose response relationships of mycotoxins important to the health of food-producing animals are presented in accompanying tables.     

单端孢霉烯族毒素生物脱毒技术研究进展

单端孢霉烯族毒素在粮食和饲料中污染严重,主要是T-2毒素和脱氧雪腐镰刀烯醇(DON)等,其毒性作用强,对人和动物产生严重危害。因此,单端孢霉烯族毒素的脱毒方式逐渐成为研究热点,尤其是生物脱毒。很多微生物被证实能够降解霉菌毒素,包括细菌、真菌和酵母菌,可将毒素降解成低毒或无毒的产物。论文以生物脱毒为出发点,从细菌、真菌和酵母菌三个角度概述了单端孢霉烯族毒素中T-2毒素和DON的脱毒研究现状,以期为后续开发并挖掘更加安全高效的生物脱毒方式提供参考。     

Dietary origin of mycotoxins with estrogenic potential and possible health implications to female dogs

In Poland, occurrence of toxigenic fungi in cereals, foods, feeds and their components as well as mycotoxins accumulation in such material has been studied by numerous teams including our research group for over thirty years since 1969. Mostly cereal kernels and feeds have been examined for presence of toxigenic fungi, their toxigenic potential and natural contamination with mycotoxins. Ochratoxin A, deoxynivalenol, nivalenol and moniliformin were found to be significant contaminants of agricultural products in high percentage of cereal grain samples. The profile of toxic metabolites was similar but the concentration levels of the toxins were lower when compared to already published data of the same climate zone. Zearalenone (ZEA), a nonsteroidal mycotoxin with estrogen-like activity, is synthesized by molds (Fusarium) commonly contaminating poorly stored agricultural products and foodstuffs. Since in the course of examinations and during surgical procedures performed in dogs, ovarian cysts were detected and because frequently this is the first stage of the endometrica pyometra complex (EPC) found in approximately 30% of the females we assume that both factors, mycotoxins (ZEA) and pathological aberrations are possibly related in these animals. Similar activity of the toxin (possibly present in pelleted dog feed) and effects including infertility of female dogs is speculated with indication and suggestion on necessity of additional studies on the problem.     

电化学生物传感器在真菌毒素检测中的研究进展

真菌毒素是真菌在食品或饲料中生长所产生的代谢产物,这些低分子质量化合物既是天然存在的,同时也是无法避免的。真菌通过两种途径进入食物链,一方面可以直接从受真菌毒素污染的植物性食品成分进入食物链;另一方面也可以通过食物中产毒真菌生长的间接污染进入食物链。真菌毒素广泛存在于成熟的玉米、谷物、大豆、高粱、花生和饲料作物中。食用受真菌毒素污染的食物或饲料会对人和动物造成急性或慢性毒性。真菌毒素除了有直接食用受霉菌毒素污染的食物和饲料造成的不良影响外,还有因为摄入动物源性食品,如肉类、牛奶或鸡蛋,含有真菌毒素的残留物或代谢物而引起的公众健康问题。目前虽然已经鉴定出超过400种真菌毒素,但食物中广泛存在的6种毒素：黄曲霉毒素、赭曲霉毒素、玉米赤霉烯酮、伏马菌素、呕吐毒素及T-2毒素,已在世界范围内引发了持续的食品安全问题。该论文总结了6种真菌毒素的毒性,重点分析了近年来电化学生物传感器在这几种真菌毒素检测中的研究进展,旨在通过一系列的总结分析去展望其在真菌毒素检测方面的发展前景。     

The effects of mycotoxins, fungal food contaminants, on the intestinal epithelial cell-derived innate immune response

Mycotoxins are structurally diverse fungal metabolites that can contaminate a variety of dietary components consumed by animals and humans. It is considered that 25% of the world crop production is contaminated by mycotoxins. The clinical toxicological syndromes caused by ingestion of moderate to high amounts of mycotoxins and their effect on the immune system have been well characterized. However, no particular attention has been focused on the effects of mycotoxins on the local intestinal immune response. Because of their location, intestinal epithelial cells (IECs) could be exposed to high doses of mycotoxins. As a component of the innate local immune response, intestinal epithelial cells have developed a variety of mechanisms which act to reduce the risk of infection by microorganisms or intoxication by toxic compounds. This review summarises the innate immune response developed by intestinal epithelial cells and reports the literature concerning the effects of mycotoxins on them. Particularly, the effects of mycotoxins on the maintenance of a physical barrier by epithelial cells will be discussed together with their effect on extrinsic protective components of the innate intestinal immunity: mucus secretion, antimicrobial peptide generation, IgA and pro-inflammatory cytokine release.     

Mycotoxicosis: mechanisms of immunosuppression.

Mycotoxins are structurally diverse secondary metabolites of fungi that grow on feedstuffs consumed by animals and man. The clinical toxicologic syndromes caused by ingestion of fungal toxins have been characterized in domestic animals, poultry and laboratory animals and range from acute mortality to decreased production. Consumption of some mycotoxins, at levels that do not cause overt clinical mycotoxicosis, suppress immune functions and may decrease resistance to infectious disease. The sensitivity of the immune system to mycotoxin-induced immunosuppression arises from the vulnerability of the continually proliferating and differentiating cells that participate in immunemediated activities and regulate the complex communication network between cellular and humoral components. Mycotoxin-induced immunosuppression may be manifested as depressed T or B lymphocyte activity, suppressed immunoglobulin and antibody production, reduced complement or interferon activity, and impaired macrophage-effector cell function. Although the cellular-molecular basis for many of the specific immunosuppressive effects of mycotoxins are presently unclear, inhibition of DNA, RNA and protein synthesis via a variety of different mechanisms appears to be directly or indirectly responsible for the immunosuppressive action of many mycotoxins.     

青贮饲料中霉菌毒素的产生、毒性作用及脱毒研究进展

青贮饲料是反刍动物日粮中重要的组成部分,但青贮饲料在收获前、发酵期间及青贮完成后都会受到多种霉菌毒素污染。反刍动物摄入霉菌毒素后会对其健康和生产性能产生不利影响,并对食品安全及人类健康构成威胁。青贮饲料中优势霉菌包括镰刀菌属(Fusarium)、曲霉属(Aspergillus)、青霉属(Penicillium)和链格孢属(Alternaria)真菌,所产生的主要霉菌毒素包括单端孢霉烯族毒素、伏马菌素、玉米赤霉烯酮、黄曲霉毒素、赭曲霉毒素、蓝酪霉菌毒素、霉酚酸和麦角生物碱等。本文将对上述毒素在青贮饲料中的产生、影响、预防和脱毒的方法进行简要综述,以期为生产优质青贮饲料提供理论支持。     

Vomitoxin and amino acid supplements in rat feed

In Finland grain has during some years contained considerable amounts of mycotoxins depending on the weather conditions, harvesting and preservation methods. The most common of these mycotoxins are Fusariumtoxins: zearalenone and trichotechenes. The trichotechene group is large, but only a few of the toxins are of practical interest in that they cause health disorders to farm animals. The most common toxin of the trichotechenes is deoksinivalenol or vomitoxin (DON), which causes, especially in pigs, vomiting and reduction in feed palatability.     

霉菌毒素对畜禽的危害及削减方法研究进展

霉菌毒素是由不同种属真菌产生的次级代谢物,其对多种动物（包括人在内）具有显著毒性效果,如降低畜禽生产性能、损害脏器功能、影响机体免疫功能、造成细胞和DNA氧化损伤,甚至导致动物死亡等。饲料及其原料霉菌毒素污染是一个广泛的、全球性的问题,既可在作物田间生长时产生,也可在仓储期间产生,给畜禽养殖业造成了巨大的经济损失,防控霉菌生长及去除饲料中霉菌毒素已成为国内外研究的热点。实际上,不同霉菌毒素对不同动物的损害具有差异性,而在畜禽养殖过程中添加适当物质（如蒙脱石和酶制剂等）可有效抑制霉菌毒素活性,缓解霉菌毒素的毒性。作者详细论述了玉米赤霉烯酮、烟曲霉毒素、呕吐毒素、T-2毒素、黄曲霉毒素和烟曲霉毒素对畜禽的危害,并从物理、化学、生物角度介绍了削减饲料及其原料中霉菌毒素的方法,旨在为合理有效防控霉菌毒素毒害及保障畜禽健康养殖提供参考。     

Plant hazards.

A variety of plants, seeds, and nuts can cause toxicosis in small animals. Some plants are not as toxic as commonly believed by the general public. Conversely, plants or nuts that are consumed by human beings can be toxic to their pets. Most plant toxins do not have specific treatments or antidotes. As a result, treatment is often limited to decontamination plus symptomatic and supportive care.     

Mycotoxin interactions in poultry and swine

Mycotoxins are toxic compounds produced by fungi. When one mycotoxin is detected, one should suspect that others also are present in a contaminated feed ingredient or finished feeds. The toxicity and clinical signs of observed in animals when more than one mycotoxin is present in feed are complex and diverse. Some mycotoxins, such as the combination of aflatoxin with either ochratoxin A or T-2 toxin, interact to produce synergistic toxicity in broiler chicks. The effects observed during multiple mycotoxin exposure can differ greatly from the effects observed in animals exposed to a single mycotoxin. For example, fatty livers in poultry are used for presumptive diagnostic identification of aflatoxicosis. However, simultaneous presence of ochratoxin A prevents fatty livers. Of the mycotoxin combinations that have been investigated in poultry and swine, the aflatoxin + ochratoxin A and aflatoxin + T-2 toxin interactions appear to be the most toxic.     

Mycotoxins: Their implications for human and animal health

Abstract

Mycotoxins contaminate various feed and food commodities, due to the global occurrence of toxinogenic molds. They exert adverse health effects in human and animals. The nature of these toxic effects varies depending on the chemical structure of the toxin. The degree of these adverse effects is not only determined by the toxin concentration present in foods and feeds, but also by the time of exposure. Whilst in animals, next to acute intoxication, losses in productivity, reduced weight gain and immunosuppression are considered as most important feature of mycotoxicoses, genotoxic effects and the involvement of certain mycotoxins such as aflatoxin, ochratoxins and fumonisins in the etiology of human cancers have obtained particular attention. This implies that recent research activities concentrate on mechanistic aspects of mycotoxin‐ induced pathologies, rather than compiling analytical measures of mycotoxin concentrations in food and feeds.     

Mycotoxins: their implications for human and animal health

Mycotoxins contaminate various feed and food commodities, due to the global occurrence of toxinogenic molds. They exert adverse health effects in human and animals. The nature of these toxic effects varies depending on the chemical structure of the toxin. The degree of these adverse effects is not only determined by the toxin concentration present in foods and feeds, but also by the time of exposure. Whilst in animals, next to acute intoxication, losses in productivity, reduced weight gain and immunosuppression are considered as most important feature of mycotoxicoses, genotoxic effects and the involvement of certain mycotoxins such as aflatoxin, ochratoxins and fumonisins in the etiology of human cancers have obtained particular attention. This implies that recent research activities concentrate on mechanistic aspects of mycotoxin-induced pathologies, rather than compiling analytical measures of mycotoxin concentrations in food and feeds.     

The role of mycotoxins in the health and performance of dairy cows

In comparison to monogastric species, ruminant animals are generally considered to be less susceptible to the adverse effects caused by contamination of feeds with mycotoxins. This is based on the assumption that the rumen flora degrade and inactivate mycotoxins, thus protecting the animal. A number of mycotoxins, however, resist rumen degradation, causing distinct clinical signs of intoxication. Moreover, due to their complex diet, dairy cows may be exposed to a varying number of mycotoxins, originating from different feed materials such as roughage and concentrates. Exposure to these complex mixtures of mycotoxins may result in unexpected health risks. Due to a pre-existing negative energy balance, cows in the transition period are considered to be particularly sensitive to the exposure to feeds contaminated with moulds, fungal spores and mycotoxins.     

Recent progress on analytical techniques for mycotoxins in feedstuffs.

Analysis of mycotoxins in feedstuffs is a difficult task because only trace amounts of the toxins are present in the sample. However, rapid progress in the area of mycotoxin analysis has been made during the last few years. Simplified sample cleanup protocols and new chromatographic methods, especially HPLC, have been developed. New, more sensitive and versatile instruments such as high-resolution mass spectrometry (MS) and gas chromatography/tandem MS/MS are coming to the market. After 15 yr of laboratory research, immunoassay techniques have gained more acceptance as analytical tools for mycotoxins. Several immunoassay kits for mycotoxins are currently available. The development of these new techniques and their application for monitoring various mycotoxins in foods and feeds are described in this review.     

Ochratoxin A in feed of food-producing animals: an undesirable mycotoxin with health and performance effects

Mycotoxins are secondary fungal metabolites, whose presence in feed- and foodstuffs is unavoidable. Ochratoxin A (OTA) is one of the known mycotoxins with greatest public health and agro-economic significance. Several toxic effects have been ascribed following exposure, namely nephrotoxicity, as well negative impacts in the performance of farm animals, resulting in major economic implications. Of no less importance for the route of human exposure that can also embody the carry-over of OTA from feed into animal-derived products is also a concern. For all these reasons the present article updates the worldwide occurrence of OTA in different raw ingredients and finished feed destined to food-producing animals. After that a brief characterization of specie susceptibility and the major rationales is made. An historical overview of field outbreaks linked to OTA exposure in farm animals, concerning the implicated feeds, contamination levels and major clinical and productivity effects is presented. Finally a review of the major animal health and performance potential impacts of animals being reared on contaminated feed is made allied to a perspective regarding its co-occurrence with other mycotoxins, and simultaneous parasitic and bacterial infections. Ultimately, this article aims to be instructive and draw attention to a mycotoxin so often neglected and elapsed from the list of differential diagnosis in farm practice. For the unpredictability and unavoidability of occurrence, OTA will definitely be an enduring problem in animal production.     

Comparison of the molecular effects of the mycotoxins beta-zearalenol and deoxynivalenol in porcine endometrial cells--a review

The mycotoxins beta-zearalenol (beta-ZOL) and deoxynivalenol (DON) produce toxic effects that result in diseases in humans and animals. The molecular mechanisms that control the mycotoxin-mediated effects are far from being completely understood. Various results show that these mycotoxins could inhibit cell proliferation. In the present short communication, the influence of beta-ZOL and DON on the abundance and phosphorylation state of kinases that are included in regulation of the initiation of mRNA translation (which is correlated with cell proliferation) was compared in porcine endometrial cells (PEC). Our results indicate that these mycotoxins modulate the expression and phosphorylation of these factors in a different manner. Whereas beta-ZOL mainly had an impact on the biological activity of the extracellular signal-regulated protein kinases 1 and 2 (ERK1/2), protein kinase B (Akt), eukaryotic initiation factor 4E (eIF4E) and its repressor 4E binding protein 1 (4E-BP1), DON reduced the abundance of p38 MAPk, Akt and specific 4E-BP1 bands. In summary, these results indicate that beta-ZOL influences molecular events that are included in the initiation of mRNA translation in the porcine endometrium but DON does not alter such processes clearly.     

镰刀菌毒素对动物毒性作用的研究进展

镰刀菌是污染粮食和饲料的主要真菌菌属之一,可产生多种高毒性、低分子量的代谢产物,如玉米赤霉烯酮、脱氧雪腐镰刀菌烯醇、T-2毒素等,这些毒素严重威胁动物和人类的健康。摄入镰刀菌毒素可对动物造成多种毒性作用,包括生殖毒性、免疫毒性、肠道毒性、肝肾毒性、细胞毒性及致癌性等。不同类型镰刀菌毒素引起的毒性作用不尽一致,且不同毒素间存在互作效应。为此,本文对单一或混合镰刀菌毒素毒性的研究进展进行了总结和归纳,为镰刀菌毒素的深入研究提供参考和借鉴。