A survey of the natural occurrence ofFusarium toxins in wheat grown ina southwestern area of Germany

Phenotypic, endocrinological, and metabolic effects of zearalenone exposure and additive effect of heat stress in prepubertal female pigs

Independently, both heat stress (HS) and zearalenone (ZEN) compromise female reproduction, thus the hypothesis that ZEN would affect phenotypic, endocrine, and metabolic parameters in pigs with a synergistic and/or additive impact of HS was investigated. Prepubertal gilts (n = 6-7) were assigned to: thermoneutral (TN) vehicle control (TC; n = 6); TN ZEN (40 μg/kg; TZ; n = 6); pair-fed (PF; n = 6) vehicle control (PC; n = 6); PF ZEN (40 μg/kg; PZ; n = 6); HS vehicle control (HC; n = 7); and HS ZEN (40 μg/kg; HZ; n = 7) and experienced either constant 21.0 ± 0.10 °C (TN and PF) or 35.0 ± 0.2 °C (12 h) and 32.2 ± 0.1 °C (12 h) to induce HS for 7 d. Elevated rectal temperature (P < 0.01) and respiration rate (P < 0.01) confirmed induction of HS. Rectal temperature was decreased (P = 0.03) by ZEN. Heat stress decreased (P < 0.01) feed intake, body weight, and average daily gain, with absence of a ZEN effect (P > 0.22). White blood cells, hematocrit, and lymphocytes decreased (P < 0.04) with HS. Prolactin increased (P < 0.01) in PC and PZ and increased in HZ females (P < 0.01). 17β-estradiol reduced (P < 0.01) in HC and increased in TZ females (P = 0.03). Serum metabolites were altered by both HS and ZEN. Neither HS nor ZEN impacted ovary weight, uterus weight, teat size or vulva area in TN and PF treatments, although ZEN increased vulva area (P = 0.02) in HS females. Thus, ZEN and HS, independently and additively, altered blood composition, impacted the serum endocrine and metabolic profile and increased vulva size in prepubertal females, potentially contributing to infertility.

Key Global Actions for Mycotoxin Management in Wheat and Other Small Grains

Mycotoxins in small grains are a significant and long-standing problem. These contaminants may be produced by members of several fungal genera, including Alternaria, Aspergillus, Fusarium, Claviceps, and Penicillium. Interventions that limit contamination can be made both pre-harvest and post-harvest. Many problems and strategies to control them and the toxins they produce are similar regardless of the location at which they are employed, while others are more common in some areas than in others. Increased knowledge of host-plant resistance, better agronomic methods, improved fungicide management, and better storage strategies all have application on a global basis. We summarize the major pre- and post-harvest control strategies currently in use. In the area of pre-harvest, these include resistant host lines, fungicides and their application guided by epidemiological models, and multiple cultural practices. In the area of post-harvest, drying, storage, cleaning and sorting, and some end-product processes were the most important at the global level. We also employed the Nominal Group discussion technique to identify and prioritize potential steps forward and to reduce problems associated with human and animal consumption of these grains. Identifying existing and potentially novel mechanisms to effectively manage mycotoxin problems in these grains is essential to ensure the safety of humans and domesticated animals that consume these grains.

TRI Genotyping and Chemotyping: A Balance of Power

Fusarium is among the top 10 most economically important plant pathogens in the world. Trichothecenes are the principal mycotoxins produced as secondary metabolites by select species of Fusarium and cause acute and chronic toxicity in animals and humans upon exposure either through consumption and/or contact. There are over 100 trichothecene metabolites and they can occur in a wide range of commodities that form food and feed products. This review discusses strategies to mitigate the risk of mycotoxin production and exposure by examining the Fusarium-trichothecene model. Fundamental to mitigation of risk is knowing the identity of the pathogen. As such, a comparison of current, recommended molecular approaches for sequence-based identification of Fusaria is presented, followed by an analysis of the rationale and methods of trichothecene (TRI) genotyping and chemotyping. This type of information confirms the source and nature of risk. While both are powerful tools for informing regulatory decisions, an assessment of the causes of incongruence between TRI genotyping and chemotyping data must be made. Reconciliation of this discordance will map the way forward in terms of optimization of molecular approaches, which includes data validation and sharing in the form of accessible repositories of genomic data and browsers for querying such data.

Long-Term Occurrence of Deoxynivalenol in Feed and Feed Raw Materials with a Special Focus on South Korea

The Fusarium fungi produce toxic substances called mycotoxins, which can cause disease and harmful effects in grains, livestock, and humans. Deoxynivalenol (DON), also known as vomitoxin, is one of the Fusarium mycotoxins that is known to cause vomiting in livestock. This study shows the occurrence of deoxynivalenol in feedstuffs (compound feed and feed ingredients) between 2009 and 2016 in South Korea. A total of 653 domestic samples were collected at five time points, including 494 compound feed samples and 159 feed ingredient samples. DON contamination levels were analyzed using high-performance liquid chromatography (HPLC) with pretreatment using an immunoaffinity column (IAC). The limit of detection (LOD) and the limit of quantification (LOQ) were estimated at 1–10 µg/kg and 3–35 µg/kg, respectively. Two compound feeds (two gestating sow feed samples) out of 160 pig feed samples exceeded the European Commission (EC) guidance value, while no feed ingredient samples exceeded the EC or South Korean guidance values. There were statistically significant differences in the mean contamination levels of compound feed and feed ingredients that indicated a decreasing trend over time.

Analytical Methods for Trichothecenes Surveillance — An Overview Over the Period 1990—2000

This article reviews some aspects of analytical methods used to determine the occurrence of type A and B trichothecenes in grains and foodstuffs and their trends during the decade 1999—2000. A pronounced tendency to use extraction solvents less toxic than chloroform became evident. There was not a prevalent clean up process that pointed there were problems to obtain good recoveries of those mycotoxins. Taking into account the mean values of contamination found in the literature and the provisional maximum tolerable daily intake, a methodology suitable for a surveillance work should have a limit of quantification not greater than 50 μg/kg for deoxynivalenol and less than 10 μg/kg for T-2 and HT-2 toxins. Therefore, gas chromatography or thin layer chromatography could be used for type B trichothecenes while for type A trichothecenes, gas chromatography with electron capture or mass spectrometric detectors is the mandatory quantification method.

Natural Co-Occurrence of Mycotoxins in Foods and Feeds and Their in vitro Combined Toxicological Effects

Some foods and feeds are often contaminated by numerous mycotoxins, but most studies have focused on the occurrence and toxicology of a single mycotoxin. Regulations throughout the world do not consider the combined effects of mycotoxins. However, several surveys have reported the natural co-occurrence of mycotoxins from all over the world. Most of the published data has concerned the major mycotoxins aflatoxins (AFs), ochratoxin A (OTA), zearalenone (ZEA), fumonisins (FUM) and trichothecenes (TCTs), especially deoxynivalenol (DON). Concerning cereals and derived cereal product samples, among the 127 mycotoxin combinations described in the literature, AFs+FUM, DON+ZEA, AFs+OTA, and FUM+ZEA are the most observed. However, only a few studies specified the number of co-occurring mycotoxins with the percentage of the co-contaminated samples, as well as the main combinations found. Studies of mycotoxin combination toxicity showed antagonist, additive or synergic effects depending on the tested species, cell model or mixture, and were not necessarily time- or dose-dependent. This review summarizes the findings on mycotoxins and their co-occurrence in various foods and feeds from all over the world as well as in vitro experimental data on their combined toxicity.

Correlation of rainfall and levels of deoxynivalenol in wheat from Uruguay, 1997-2003

A total of 286 wheat samples for human consumption collected during 1997-2003 from four wheat-producing localities of south-western Uruguay were screened for deoxynivalenol (DON). Quantification was carried on by an immunochemical method using immunoaffinity columns and fluorimetric detection. The incidence of DON was high during the whole survey (58.5-100%), except in 1998 and 1999 in which no contamination occurred. During 2001 and 2002, 100% of samples contained detectable levels of DON, being the mean DON contents 6593 and 5880 µg kg(-1), respectively. The annual maximum levels ranged from 8800 to 11,400 µg kg(-1). A positive correlation between DON levels and precipitation was seen. The 70% of wheat samples destined for human consumption were contaminated with DON. To avoid the introduction of contaminated materials into the food chain process, the adoption of regular screening of the DON level in wheat is recommended, particularly in years with heavy rainfall during the flowering-to-early stages of grain maturity months.

Mycotoxins in the environment: I. Production and emission from an agricultural test field

Mycotoxins are secondary metabolites that are naturally produced by fungi which infest and contaminate agricultural crops and commodities (e.g., small grain cereals, fruits, vegetables, and organic soil material). Although these compounds have extensively been studied in food and feed, only little is known about their environmental fate. Therefore, we investigated over nearly two years the occurrence of various mycotoxins in a field cropped with winter wheat of the variety Levis, which was artificially inoculated with Fusarium spp., as well as their emission via drainage water. Mycotoxins were regularly quantified in whole wheat plants (0.1-133 mg/kg(dry weight), for deoxynivalenol), and drainage water samples (0.8 ng/L to 1.14 μg/L, for deoxynivalenol). From the mycotoxins quantified in wheat (3-acetyl-deoxynivalenol, deoxynivalenol, fusarenone-X, nivalenol, HT-2 toxin, T-2 toxin, beauvericin, and zearalenone), only the more hydrophilic ones or those prevailing at high concentrations were detected in drainage water. Of the total amounts produced in wheat plants (min: 2.3; max: 292 g/ha/y), 0.5-354 mg/ha/y, i.e. 0.002-0.12%, were emitted via drainage water. Hence, these compounds add to the complex mixture of natural and anthropogenic micropollutants particularly in small rural water bodies, receiving mainly runoff from agricultural areas.

Occurrence, Rapid Analysis, and Detoxification of Fumonisins in Maize and its Feeds: Review

Maize (Zea mays L.) is one of the main cereals as a source of food, forage and processed products for industry, especially for feeds. However, in worldwide approximately 25% of crops are affected by mycotoxins annually, especially in feeds with fumonisins(FUM). Moreover, the exact mechanism of FUM toxicity is not completely established. This paper gives an overview about the occurrence, toxicity, rapid non-invasive analysis, and detoxification of FUM in maize and its feeds. Due to economic losses engendered by FUM and its impact on animal and human health, several strategies for detecting mycotoxins with non-invasive methods and detoxifying contaminated feeds have been described.

Within-field variation of Fusarium graminearum isolates for aggressiveness and deoxynivalenol production in wheat head blight

Fusarium head blight (FHB), caused by Fusarium graminearum sensu stricto (s.s.), causes tremendous annual yield losses in wheat worldwide. Variation of aggressiveness of isolates from individual field populations in terms of FHB infection and deoxynivalenol (DON) concentration in the host are important population parameters reflecting parasitic ability. Our main objective was to estimate the variation of both traits within three populations of F. graminearum s.s., each consisting of 30 single-spore isolates collected from small wheat fields in Germany, and to compare it with 11 isolates of a collection (F. graminearum collection) from four countries. The same isolates were characterized using 19 single-sequence repeat markers. All isolates were spray inoculated on a moderately resistant spring wheat cultivar at two field locations over 2 years (i.e., in four environments). The genotypic proportion of phenotypic variance (σ(2)(G)) within populations was significant (P < 0.01) for both traits, and the σ(2)(G) × environment interaction was even more important for mean FHB severity. Ranges in mean FHB severity and DON concentration in the host were only slightly smaller for the field populations than for the F. graminearum collection. Both traits were significantly (P < 0.05) correlated within and across populations. A further partitioning of σ(2)(G) revealed 72% of σ(2)(G) within and 28% of σ(2)(G) across populations for both traits. Molecular variance of the three populations was similarly distributed (73.6% within versus 26.4% between populations). In view of this high within-field variation for traits of parasitic ability and selection, neutral molecular markers, multiple resistance genes of different origin should be employed in wheat breeding programs to obtain a long-term stable FHB resistance.

Effects of deoxynivalenol (DON, vomitoxin) on in utero development in rats

Deoxynivalenol (DON, vomitoxin), is one of the most common contaminants of cereal grains world-wide. The effects of DON on fetal development were assessed in Charles River Sprague-Dawley rats. Pregnant female rats were gavaged once daily with DON at doses of 0, 0.5, 1, 2.5, or 5 mg/kg body weight on gestation days (GD) 6-19. At cesarean section on GD 20, reproductive and developmental parameters were measured. All females survived to cesarean section. DON caused a dose-related increase in excessive salivation by the pregnant females, a reaction probably linked to the lack of emetic reflex in rats. At 5 mg/kg, feed consumption and mean body weight gain were significantly decreased throughout gestation, mean weight gain (carcass weight), and gravid uterine weight were significantly reduced, 52% of litters (12/23) were totally resorbed, the average number of early and late deaths per litter was significantly increased, average fetal body weight and crown-rump length were significantly decreased, the incidence of runts was significantly increased, and the ossification of fetal sternebrae, centra, dorsal arches, vertebrae, metatarsals, and metacarpals was significantly decreased. At 2.5 mg/kg, DON significantly decreased average fetal body weight, crown-rump length, and vertebral ossification. These effects may be secondary to maternal toxicity and the reduced size of the fetuses. The incidence of misaligned and fused sternebrae was significantly increased at 5.0 mg/kg. No adverse developmental effects were observed at 0.5 and 1.0 mg/kg. Dose-related increases in maternal liver weight-to-body weight ratios were observed in all treated groups (significant at 1, 2.5, and 5 mg/kg). The weight changes were correlated with dose-related cytoplasmic alterations of hepatocytes. The NOEL for maternal toxicity for this study is 0.5 mg/kg based on the dose-related increase in liver-body weight ratio at 1 mg/kg. The NOEL for fetal toxicity is 1 mg/kg based on the general reduction in fetal development at 2.5 and 5 mg/kg. DON is considered a teratogen at 5 mg/kg day in Sprague-Dawley rats based on the anomalous development of the sternebrae.

Liquid chromatography/tandem mass spectrometry for the identification and determination of trichothecenes in maize

A reliable, sensitive and selective liquid chromatography/tandem mass spectrometry (LC/MS/MS) method has been developed to determine four trichothecene mycotoxins (nivalenol, deoxynivalenol, fusarenon X and 3-acetyldeoxynivalenol) in maize. Sample preparation was performed by extracting the analytes with a mixture of acetonitrile and water, followed by a solid-phase extraction with Carbograph-4 cartridges as the purification step. For the LC/MS/MS analysis two interfacing systems, Turbo IonSpray (TISP) and atmospheric pressure chemical ionization (APCI), were compared in both negative and positive ion modes. LC and MS parameters were optimized to achieve better results and sensitivity. The effect of mobile phase modifiers such as ammonium acetate and formic acid on the ionization yield was also evaluated. The best results were obtained using the electrospray ionization (ESI) interface in negative ion mode and the multiple reaction monitoring mode (MRM) for the quantitation. The detection limits ranged between 10 ng/g for fusarenon X and 1.5 ng/g for deoxynivalenol. A linear working range was achieved with a standard deviation between 3 and 10% and recovery rates from the maize samples above 81%. The procedure was applied to the analysis of a set of maize samples collected from farms located in different areas of northern and central Italy. The investigated samples turned out to be contaminated primarily with deoxynivalenol and, to a minor extent, with its derivatives.

Evaluation of mycotoxin-contaminated cereals for their use in animal feeds in Hungary

In the period between December 5, 1991 and September 17, 1998, 760 maize, 367 wheat, 119 soybean, 222 barley, 85 bran, 32 triticale, 60 oat, 14 rye and 22 sunflower samples were investigated for the presence and concentration of seven fusariotoxins (T-2 toxin, zearalenone, deoxynivalenol, nivalenol, diacetoxyscirpenol, HT-2 toxin, fusarenone-X) and OTA. The comparison of analytical data with those of the relevant literature revealed that although the incidence rate and/or concentration of Fusarium mycotoxins and OTA in Hungarian-grown cereals is occasionally considerable, the position of the country is not worse that the average of countries. Our findings indicate that soybean tends to be good substrate for trichothecene-producing fungi and the rate of contamination is regarded as substantial. The commodities were assorted into one of three quality categories. The proportion of objectionable samples was only 3.0, 2.2, 2.3 and 1.7% in maize, wheat, barley and soybean samples, respectively. However, this low rate of objection might still be a source of great economic loss. The proportion of objectionable samples was much higher in the case of bran, oat and triticale (7.1, 6.7, and 6.3%, respectively). The results of the present investigation indicate a need for regular screening for mycotoxins of importance and individual appraisal of each commodity from the point of their use in animal feeds.

Natural occurrence of Fusarium toxins in oats harvested during five years in an area of southwest Germany

A total of 56, 56, 54, 51, and 55 oats samples used for feed production were collected randomly after the 1987, 1989, 1990, 1991 and 1992 crops, respectively, from farms located in an area of southwest Germany. Deoxynivalenol (DON), 3- and 15-acetyl-deoxynivalenol (3-, 15-ADON), nivalenol (NIV), fusarenon-X (FUS-X), T-2 toxin (T-2), HT-2 toxin (HT-2) and diacetoxyscirpenol (DAS) were determined by gas chromatography with mass selective detection (GC-MS), zearalenone (ZEA), alpha and beta-zearalenol (alpha-, beta-ZOL) by GC-MS or by HPLC. DON was the major toxin with incidences at 49-85% and mean levels in positive samples of 52-302 micrograms/kg. Incidences of ZEA, 3-ADON, NIV, HT-2, and T-2 were at 20-37, 0-30, 18-67, 0-29, and 27-61%, respectively, with mean levels in positive samples at 8-25, 5-63, 11-192, 205-296, and 20-244 micrograms/kg, respectively. alpha- and beta-ZOL and DAS were not detected in any sample. 15-ADON and FUS-X were assayed in samples from 1987, 1991 and 1992. 15-ADON was detected in 9, 4 and 0% of samples, with an average of 9 and 18 micrograms/kg, respectively; FUS-X was not detected. The incidence and levels of toxins varied from year to year. The correlation between the occurrence of toxins and precipitation is discussed.

Deoxynivalenol and Nivalenol Production by Fusarium culmorum Isolates Differing in Aggressiveness Toward Winter Rye

ABSTRACT A susceptible synthetic winter rye population was inoculated with 42 isolates of Fusarium culmorum, originating from nine European countries and Australia, at two field locations in Germany. Significant (P = 0.01) genetic variation in aggressiveness of isolates of F. culmorum was observed across both field locations. Field samples were used to determine deoxynivalenol (DON), nivalenol (NIV), and ergosterol (ERG) contents. The 42 isolates also were incubated on rye grain in vitro, and DON and NIV contents were analyzed. Thirty-four isolates produced DON, and seven isolates produced NIV at both field locations and in vitro. Mean DON contents ranged from 0.5 to 64.6 mg/kg in grain from field trials and from 0.3 to 376.3 mg/kg in grain incubated in vitro; mean NIV contents ranged from 17.6 to 30.4 mg/kg in grain from field trials and from 0.8 to 381.0 mg/kg in grain incubated in vitro. No correlation was found between the DON content of field-grown grain and grain incubated in vitro. NIV-producing isolates originated from the Netherlands, Germany, Italy, and Australia. More aggressive isolates produced higher mean DON contents in grain in field trials (r = 0.69; P = 0.01). However, DON production rate per unit of fungal biomass, estimated as the DON/ERG ratio at harvest, was not correlated with aggressiveness. Toxin production seemed to be a common feature in F. culmorum. In vitro assays reliably distinguished DON- and NIV-producing types of F. culmorum; however, these assays could not predict production of DON by these isolates in the field.

Occurrence of deoxynivalenol and Fusarium graminearum in Argentinian wheat

During the 1993 harvest period there was a high incidence of Fusarium head blight in wheat in Argentina. Fusarium species that produce trichothecenes in wheat have been reported in several countries including Argentina. Several studies have shown that F. graminerarum and deoxynivalenol (DON) were the main contaminants detected in wheat and by-products in Argentina. The objective of this study was to evaluate the occurrence of Fusarium spp. and DON contamination in wheat from Córdoba, Argentina during the 1993/94 harvest season. F. graminearum was the main Fusarium species isolated. From 40 samples analysed, 80% showed DON contamination. The levels of DON found ranged between 300 and 4500 micrograms/kg. There was good correlation between F. graminearum and DON contamination. Only five samples showed levels of DON higher than those established in the guidelines in Canada and the USA for food and feedstuffs.

Natural occurrence of Fusarium mycotoxins in field samples from the 1992 Wisconsin corn crop

Analysis of 98 moldy corn samples collected in Wisconsin between November 1992 and January 1993 for Fusarium toxins by various immunochemical assays revealed overall average mycotoxin concentrations of 305.6, 237.7, and 904.3 ng/g for type A trichothecenes (TCTCs), deoxynivalenol (DON)-related type B TCTCs (total DON), and zearalenone (ZE), respectively. A small portion (5.1%) of the samples was found to be contaminated with high levels ( > 1 microgram/g) of type A TCTCs and total DON during the whole survey. Over 40% of the samples had 100 to 1,000 ng of total DON per g, while 17% of the samples had the same levels of type A TCTCs. The analytical data were consistent with those from mycological examinations for the samples in which various toxic Fusarium spp., including F. sporotrichioides, F. poae, and F. graminearum, were found. The samples received in November 1992 had relatively low concentrations of toxin; the average levels of type A TCTCs and total DON were 9.9 and 79 ng/g, respectively. The toxin concentrations became progressively higher in the samples received in December. The average levels for the type A TCTCs and total DON increased to 920 and 335 ng/g, respectively. However, the levels of ZE were higher in the samples collected earlier. The average levels for samples collected in November and late December were 1,195 and 242 ng/g, respectively. Analysis of selected samples by high-performance liquid chromatography monitoring with an enzyme-linked immunosorbent assay revealed that T-2 toxin, HT-2 toxin, diacetoxyscirpenol, neosolaniol, and T-2 tetraol (T-2-4ol) were common in these samples. Statistical analysis revealed a weak correlation between the levels of total type A TCTCs and total DON in the samples (r = 0.18, P = 0.09), but a strong correlation between the levels of ZE and total type B TCTCs (r = 0.75, P < 0.0001) was found. The mycotoxin levels of total type A TCTCs, total DON-related type B TCTCs, and ZE in the cobs (5.2, 3.9, and 21 micrograms/g, respectively) were considerably higher than those in the kernels (1.0, 0.5, and 0.5 microgram/g, respectively). The type A toxin levels increased from a range of 14 to 35 ng/g to a range of 110 to 538 ng/g after the moldy corn samples were held at 5 degrees C for 8 days in the laboratory.

Individual and combined effects of T-2 toxin and DAS in laying hens

1. The individual and combined effects of T-2 toxin and 4,15-diacetoxyscirpenol (DAS) on laying hens were investigated in an experiment consisting of a 2 x 2 completely randomised factorial design with dietary concentrations of 0 and 2 mg/kg T-2 toxin and 0 and 2 mg/kg DAS. 2. Individually, T-2 toxin and DAS induced oral lesions in half of the hens and decreased significantly egg production and food intake. 3. The effects of T-2 toxin and DAS were additive for reduced food consumption and incidence of oral lesions. However, a synergism for reduced egg production was observed during the last experimental period. 4. No effects on body weight were observed during this study. Mild changes in selected plasma enzymes activities and no change in liver malondialdehyde content were detected. 5. The combination of T-2 toxin and DAS was more toxic than the single mycotoxins, for some parameters, and therefore, may pose a greater economic threat to the poultry industry than either of the toxins individually.

[Effect of the fungicide matador (tebuconazole/triadimenol) on mycotoxin production by Fusarium culmorum]

Applications of the fungicide Matador to winter wheat (Slejpner) inoculated at earing with Fusarium culmorum resulted in a considerable decrease in the incidence of Fusarium headblight. In the study presented here, subsequent mycotoxin analyses by selected ion monitoring gas chromatography-mass spectrometry revealed higher levels of nivalenol (NIV) in samples singly treated with Matador at 1 L/ha. Amounts as high as 2432 micrograms NIV/kg and 860 micrograms NIV/kg, representing a 16- or six-fold increase as compared to controls, were found in wheat treated with the fungicide 3 h before or 24 h after inoculation of the grain with F. culmorum, respectively. In parallel, higher cytotoxic activities of these samples were obtained when testing crude sample extracts in the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT)-cell culture bioassay using swine kidney monolayers as target cells. It is concluded that treatment of grain with the fungicide Matador could result in a marked stimulation of the production of NIV by F. culmorum. As the incidence of Fusarium headblight did not correlate with the amount of mycotoxins found, the need for mycotoxin analyses combined with bioassays such as the MTT-cell culture assay is recommended for a meaningful assessment of the quality of grain treated in such a manner.