Accumulation of type A trichothecenes in maize, wheat and rice by Fusarium sporotrichioides isolates under diverse culture conditions

Convalescent action of menthol against T-2 mycotoxin-induced toxicity: An in vitro study with HaCaT cells

Only T-2 mycotoxin is emitted as an aerosol and is the most toxic fungal secondary metabolite among mycotoxins. In its clinical condition, the skin is severely irritated and painful due to lesions and alimentary toxic aleukia. Herein, we have assessed various bioactive molecules, viz. kaempferol, menthol, curcumin, and quercetin, against T-2-induced toxicity in HaCaT cells. Menthol offered exceptional protection, protecting 92% of HaCaT cells after exposure to 300 nM T-2 and reducing LDH leakage by up to 42%. Its pre-treatment provided considerable protection against T-2 toxicity, as evidenced by the assessment of mitochondrial membrane potential. Propidium iodide staining revealed a cell cycle halt at the G1, S, and M phases and a significant increase in the sub-G1 percentage in T-2-challenged cells, indicating cell death. However, pre-treatment with menthol promoted cell cycle progression in cells exposed to T-2. Immunoblotting results demonstrated that menthol resulted in a discernible down-regulation of i-NOS expression in T-2-challenged HaCaT cells.

A new headspace solid-phase microextraction coupled with gas chromatography-tandem mass spectrometry method for the simultaneous quantification of 21 microbial volatile organic compounds in urine and blood

Mold growth can cause the development of several metabolites including microbial volatile organic compounds (mVOCs). These latter may be considered as potential biomarkers of fungal presence and have been detected in human biological matrices such as urine and blood. Exposure to molds and their metabolites (e.g., mVOCs, mycotoxins) in occupational settings, is responsible for several health effects. Thus, this exposure cannot be neglected and must be evaluated. Herein, a method has been developed to quantify 21 mVOCs in urine and human blood by headspace solid phase micro-extraction (HS-SPME) coupled with gas chromatography-triple quadrupole mass spectrometry (GC-MS/MS). The parameters influencing the extraction process, such as the type of fiber, the incubation and extraction time and temperature and the desorption time, have been optimized to ensure better mVOCs extraction. The developed method showed good linearity over the concentration range of the compounds (R² ˃ 0.995) for all the mVOCs in all the matrices. The low limits of detection (LOD) ranging from 0.7 to 417 ng/L in urine and from 1 to 507 ng/L in blood, make the developed methods sensitive and effective for biomonitoring of exposure at low levels. Recoveries, at low and high concentrations, were between 87% and 120% in urine and between 83% and 118% in blood. The repeatability and the intermediate precision in terms of coefficients of variation (CV%) was lower than 13% and 8.58% respectively for all compounds in all matrices. These values show satisfactory accuracy and precision of the developed method. Thus, this practical, simple, and sensitive method is well suited for the simultaneous quantification of target mVOCs.

Determination of T-2 and HT-2 Toxins in Seed of Milk Thistle [Silybum marianum (L.) Gaertn.] Using Immunoaffinity Column by UPLC-MS/MS

Milk thistle [Silybum marianum (L.) Gaertn.] achieved a significant increase in interest over the past few years from local and foreign pharmaceutical corporations. The silymarin complex of constituents extracted from milk thistle achenes provides compelling health benefits primarily thanks to antioxidant activities and hepatoprotective effects. However, consuming mycotoxin-contaminated plant material can cause immunosuppression and hepatotoxic problems. The aim of this study was to develop and validate a method for the determination of mycotoxin content in milk thistle. Fusarium toxins as T-2 and HT-2 toxins in grown milk thistle harvested from a breeding station in the Czech Republic during 2020-2021 were studied. The analysis of T-2 and HT-2 toxins was performed by UPLC-MS/MS after immunoaffinity columns EASI-EXTRACT® T-2 & HT-2 clean up. All analysed samples of milk thistle were contaminated with T-2 toxin and HT-2 toxin. The content of T-2 toxin in the samples from 2020 was in the range of 122.7-290.2 µg/kg and HT-2 toxin 157.0-319.0 µg/kg. In 2021, the content of T-2 toxin was in the range of 28.8-69.9 µg/kg and HT-2 toxin was 24.2-75.4 µg/kg. The results show that the climatic conditions of the year of harvesting have a highly statistically significant effect on the content of T-2 and HT-2 toxins in milk thistle.

Reduction of the Fusarium Mycotoxins: Deoxynivalenol, Nivalenol and Zearalenone by Selected Non-Conventional Yeast Strains in Wheat Grains and Bread

Mycotoxins, toxic secondary metabolites produced by fungi, are important contaminants in food and agricultural industries around the world. These toxins have a multidirectional toxic effect on living organisms, causing damage to the kidneys and liver, and disrupting the functions of the digestive tract and the immune system. In recent years, much attention has been paid to the biological control of pathogens and the mycotoxins they produce. In this study, selected yeasts were used to reduce the occurrence of deoxynivalenol (DON), nivalenol (NIV), and zearalenone (ZEA) produced by Fusarium culmorum, F. graminearum, and F. poae on wheat grain and bread. In a laboratory experiment, an effective reduction in the content of DON, NIV, and ZEA was observed in bread prepared by baking with the addition of an inoculum of the test yeast, ranging from 16.4% to 33.4%, 18.5% to 36.2% and 14.3% to 35.4%, respectively. These results indicate that the selected yeast isolates can be used in practice as efficient mycotoxin decontamination agents in the food industry.

Ecophysiology of Fusarium chaquense a Novel Type A Trichothecene Producer Species Isolated from Natural Grasses

Fusarium chaquense, a recently formally described novel species, has been identified as an T-2 toxin (T-2), HT-2 toxin (HT-2) and other toxins producer in natural grasses (Poaceae) from Argentina. The major objective of this study was to describe the effect of water activity (aW, 0.995, 0.98, 0.95, 0.93 and 0.91), temperature (15, 25 and 30 °C) and incubation time (5, 15 and 25 days) on growth and to evaluate the production of T-2, HT-2 toxins and beauvericin (BEA) by two F. chaquense strains in a grass-based media. The results showed a wide range of conditions for F. chaquense growth and mycotoxin production. Both strains had a maximum growth rate at the highest aW (0.995) and 25 °C. Regarding mycotoxin production, more T-2 than the other analysed mycotoxins were produced by the two strains. T-2 production was favoured at 0.995 aW and 30 °C, while HT-2 production at 0.98-0.95 aW and 15 °C. The maximum levels of BEA were produced at 0.995 aW and 25-30 °C. Two-dimensional profiles of aW by temperature interactions were obtained from these data in order to identify areas where conditions indicate a significant risk of mycotoxins accumulation on grass. For its versatility on growth and mycotoxin production in a wide range of aW and temperatures, F. chaquense would have an adaptive advantage over other Fusarium species, and this would explain its high frequency of isolation in natural grasses grown up in the Chaco wetlands.

A fluorescence aptasensor based on controlled zirconium-based MOFs for the highly sensitive detection of T-2 toxin

T-2 toxin is one of class A trichothecene mycotoxins produced by Fusarium, presenting genotoxic, cytotoxicity, and immunotoxicity for animals and humans. Therefore, It is urgent to establish a rapid test method with high sensitivity, good selectivity and reliability. In this research, by adjusting the synthesis conditions, a kind of NH₂-UiO-66 with high quenching efficiency was screened out. On this basis, we constructed a novel fluorescence sensor via Cy3-labeled aptamer (Cy3-aptamer). With the help of π-π interaction, hydrogen bond and coordination, NH₂-UiO-66 could adsorb and quench the fluorescence of Cy3-aptamer based on FRET and PET. In the presence of T-2 toxin, it recognized and bound to Cy3-aptamer, leading to the disintegration of the NH₂-UiO-66/Cy3-aptamer compound. As the energy transfer process was blocked, the fluorescence intensity was restored, enabling a highly sensitive response to T-2 toxin. There was a good linear correlation between fluorescence intensity and T-2 toxin concentration in the range of 0.5-100 ng ml ^-1. The LOD of this fluorescence aptasensor was 0.239 ng ml^-1 (S/N = 3). Besides, the recoveries of milk and beer were 89.86-108.99% (RSD = 2.0-2.6%) and 92.31-111.51% (RSD = 2.3-2.9%), respectively. The fluorescence aptasensor exhibited advantages of excellent analytical performance, convenient operation procedure and good selectivity. Predictably, the aptasensor was supposed to detect antibiotics and other pollutants, describing an intriguing blueprint and potential application prospect in food safety, biochemical sensing and environmental conservation.

Trichothecenes in Food and Feed, Relevance to Human and Animal Health and Methods of Detection: A Systematic Review

Trichothecene mycotoxins are sesquiterpenoid compounds primarily produced by fungi in taxonomical genera such as Fusarium, Myrothecium, Stachybotrys, Trichothecium, and others, under specific climatic conditions on a worldwide basis. Fusarium mold is a major plant pathogen and produces a number of trichothecene mycotoxins including deoxynivalenol (or vomitoxin), nivalenol, diacetoxyscirpenol, and T-2 toxin, HT-2 toxin. Monogastrics are sensitive to vomitoxin, while poultry and ruminants appear to be less sensitive to some trichothecenes through microbial metabolism of trichothecenes in the gastrointestinal tract. Trichothecene mycotoxins occur worldwide however both total concentrations and the particular mix of toxins present vary with environmental conditions. Proper agricultural practices such as avoiding late harvests, removing overwintered stubble from fields, and avoiding a corn/wheat rotation that favors Fusarium growth in residue can reduce trichothecene contamination of grains. Due to the vague nature of toxic effects attributed to low concentrations of trichothecenes, a solid link between low level exposure and a specific trichothecene is difficult to establish. Multiple factors, such as nutrition, management, and environmental conditions impact animal health and need to be evaluated with the knowledge of the mycotoxin and concentrations known to cause adverse health effects. Future research evaluating the impact of low-level exposure on livestock may clarify the potential impact on immunity. Trichothecenes are rapidly excreted from animals, and residues in edible tissues, milk, or eggs are likely negligible. In chronic exposures to trichothecenes, once the contaminated feed is removed and exposure stopped, animals generally have an excellent prognosis for recovery. This review shows the occurrence of trichothecenes in food and feed in 2011-2020 and their toxic effects and provides a summary of the discussions on the potential public health concerns specifically related to trichothecenes residues in foods associated with the exposure of farm animals to mycotoxin-contaminated feeds and impact to human health. Moreover, the article discusses the methods of their detection.

A Two-Year Occurrence of Fusarium T-2 and HT-2 Toxin in Croatian Cereals Relative of the Regional Weather

To investigate into the T-2 and HT-2 toxin occurrence, 240 samples of unprocessed cereals (maize, wheat, barley, and oats) were sampled from different fields located in three Croatian regions during 2017-2018. In all samples, sum concentrations of T-2/HT-2 toxin were determined using the ELISA method, while the LC-MS/MS was used as a confirmatory method for both mycotoxins in positive samples (>LOD) and the establishment of T-2 over HT-2 toxin ratios. The results showed oats to be the most contaminated cereal, with T-2/HT-2 toxins detected in 70.0% of samples, followed by barley (40.9%), maize (26.8%) and wheat (19.2%), with the mean T-2/HT-2 ratio ranging from 1:2.7 in maize to 1:4.4 in oats. Sum T-2/HT-2 concentrations in two maize samples were higher than the indicative level recommended by the European Commission, necessitating subsequent investigations into the conditions under which these poorly investigated mycotoxins are produced. Statistically significantly (p < 0.05) higher concentrations of T-2/HT-2 toxin were determined in oats throughout study regions as compared to those found in wheat, but not maize and barley, while the concentrations of these mycotoxins were related to the regional weather in Croatia.

Distribution and persistence of residual T-2 and HT-2 toxins from moldy feed in broiler chickens

T-2 and HT-2 widely found in food products can seriously affect human and animal health. In this study, sterilized corn was inoculated with F. poae and incubated to allow fungal growth before being examined via liquid chromatography coupled to tandem mass spectrometry (HPLC-MS/MS) to determine the concentrations of T-2/HT-2. Broilers were then fed with a mix of moldy corn and normal feed at different ratios to obtain different toxin doses. After 35 days, the contaminated feed was replaced with mycotoxin-free feed and the distribution and concentration of residual toxins in the tissues and organs of the chickens were examined at different time points. The results showed that at the time of feed replacement (0 h), T-2 residue was present at significantly higher concentrations in the lungs and small intestines than in other tissues (P < 0.05). In addition, T-2 concentrations increased in a dose-dependent manner in the tissues of chickens in the low-, medium-, and high-dose groups; however, the differences in concentration between the groups were not statistically significant. The HT-2 content (0 h) in the livers and small intestines was significantly higher than that in other tissues (P < 0.05). At 48 h post-feed replacement, the concentration of T-2 dropped below detectable levels in all tissues while HT-2 could still be detected at 192 h post-feed replacement. Thus, this study reveals the distribution and persistence of residual T-2/HT-2 from moldy feed in broilers, providing a reference for the detection of these toxins in animal-derived food products and a theoretical basis for formulating food-safety and quality standards.

Effects of T-2 toxin on digestive enzyme activity, intestinal histopathology and growth in shrimp Litopenaeus vannamei

T-2 toxin (T-2), a naturally occurring mycotoxin that often accumulates in aquatic animals via contaminated feed, is toxic to animals, including humans. In this study, six groups of shrimp (n = 30 shrimps/group) were given T-2 in feed at concentrations of 0–12.2 mg/kg for 20 days. T-2 accumulation, intestinal histopathology, digestive enzyme activities and subsequent effects on shrimp are reported. Compared to the control, T-2 significantly reduced weight gain, specific growth rate, and survival. The histopathology of shrimp intestine showed concentration-dependent degenerative and necrotic changes in response to dietary T-2. Progressive damage to the microstructures of shrimp intestine occurred with increasing dietary T-2 concentrations, with initial inflammation of the mucosal tissue at T-2 concentrations of 0.5 and 1.2 mg/kg, progressing to disappearance of intestinal villi and degeneration and necrosis of the submucosa at 12.2 mg/kg. Intestinal amylase and protease activities increased at low T-2 concentrations but showed significant inhibition at high concentrations; however, the opposite trend occurred for lipase activity. Collectively, these results indicate that digestive enzyme activities and mucosal structures are markedly affected by exposure to T-2, and these may have contributed to the lower survival rate of shrimp.

Effects of T-2 toxin on histopathology, fatty acid and water distribution of shrimp (Litopenaeus vannamei) muscle

T-2 toxin (T-2), one of the naturally occurring mycotoxins, often accumulates in aquatic animals from contaminated feed. Shrimp (n = 30 per group) were fed with different concentrations (0, 0.5, 1.5, 4.5 and 13.5 mg kg^-1) of T-2 for 20 days. Changes in histopathology, fatty acid and water distribution of shrimp muscle were analyzed. Histopathology of shrimp muscle showed dose-dependent marked degenerative and necrotic changes on exposure to dietary T-2. The T-2 significantly (P < 0.05) affected the muscle fatty acid composition. ∑SFA, ∑MUFA and ∑PUFA initially decreased and then increased slowly in the high-dosed groups. C16:0, C18:1n-9 and C18:2n-6 were the main saturated fatty acid (SFA), monounsaturated fatty acid (MUFA) and polyunsaturated fatty acid (PUFA), respectively. Also, T-2 significantly affected water distribution in shrimp muscle. High doses of T-2 reduced free water content, resulting in a reduction in the water holding capacity and hence changes to the shrimp muscle quality. Collectively, these results illustrated that T-2 significantly affects the fatty acid and water distribution, and also muscle histopathology, all of which would result in a reduction in the quality and nutritional value of shrimp.

The Caryopsis of Red-Grained Rice Has Enhanced Resistance to Fungal Attack

Seed persistence in the soil is threatened by microorganisms, but the seed coat helps protect the seed from them. Although modern rice (Oryza sativa L.) cultivars have a whitish caryopsis, some varieties have a red caryopsis coat, a trait typical of wild Oryza species. The red colour is due to the oxidation of proanthocyanidins, a class of flavonoids that is found in the outer layers of the seed in many species. We aimed to assess whether these natural compounds (proanthocyanidins and proanthocyanidin-derived pigment) have some protective effect against microbial attacks. Dehulled caryopses of white-grained and red-grained rice genotypes were employed to assay fungal infection. Specifically, three white-grained rice cultivars (Perla, Augusto, and Koral) and three red-grained rice varieties (Perla Rosso, Augusto Rosso, and Koral Rosso) were used. In a first test, the caryopses were infected with Epicoccum nigrum at 10 °C, and seedling growth was then assessed at 30 °C. In a second test, the degree of infection by the mycotoxigenic fungus Fusarium sporotrichioides was assayed by measuring the accumulation of T-2/HT-2 toxins in the caryopses. Infection was performed at 10 °C to prevent rice germination while allowing fungal growth. In both the tests, red caryopses showed reduced, or delayed, infection with respect to white ones. One black-grained cultivar (Venere) was assayed for the accumulation of T-2/HT-2 toxins as well, with results corresponding to those of the red-grained rice varieties. We argue that the red pigment accumulating in the caryopsis coat, and/or the proanthocyanidins associated with it, provides a protective barrier against challenging microorganisms.

Deoxynivalenol and zearalenone in unprocessed cereals and soybean from different cultivation regions in Croatia

The aim of this study was to investigate the occurrence of deoxynivalenol (DON) and zearalenone (ZEN) in unprocessed cereals and soybean sampled in 2014 and 2015 from different fields located in Croatian regions. A total of 306 samples were analysed for DON and 415 samples for ZEN concentrations using quantitative ELISA methods. In 2014, DON and ZEN were determined in all samples in the mean concentrations of 1,461 ± 2,265 µg/kg and 656 ± 853 µg/kg, respectively, while in 2015 these means were 2,687 ± 2,731 µg/kg and 1,140 ± 1,630 µg/kg, respectively. The cultivation year significantly (p < 0.05) influenced mycotoxin concentrations, whereas the influence of cultivation region was seen with ZEN for all cereals except soybean, and not seen with DON at all. A higher contamination determined during 2015 could be explained by high to extreme humidity evidenced in the period of cereals' growth and harvesting.

Deoxynivalenol in wheat, maize, wheat flour and pasta: surveys in Hungary in 2008-2015

Among Fusarium mycotoxins, deoxynivalenol (DON) is the most common contaminant in case of cereals and cereal-based foods in Hungary. In this study, Hungarian wheat (n = 305), maize (n = 108), wheat flour (n = 179) and pasta (n = 226) samples were analysed (N = 818). The samples were collected during 2008-2015 in Hungary. Applied methods of analysis were enzyme-linked immunosorbent assay and liquid-chromatography coupled with a mass spectrometer. Results were compared and evaluated with Hungarian weather data. Among cereal samples, in 2011, wheat was contaminated with DON (overall average ± standard deviation was 2159 ± 2818 µg kg^-1), which was above the maximum limit (ML). In case of wheat flour and pasta, no average values above ML were found during 2008-2015, but higher DON contamination could be observed in 2011 as well (wheat flour: 537 ± 573 µg kg^-1; pasta: 511 ± 175 µg kg^-1).

Identification and Characterization of Spontaneous Auxotrophic Mutants in Fusarium langsethiae

Analysis of 49 strains of Fusarium langsethiae originating from northern Europe (Russia, Finland, Sweden, UK, Norway, and Latvia) revealed the presence of spontaneous auxotrophic mutants that reflect natural intraspecific diversity. Our investigations detected that 49.0% of F. langsethiae strains were auxotrophic mutants for biotin, and 8.2% of the strains required thiamine as a growth factor. They failed to grow on vitamin-free media. For both prototrophic and auxotrophic strains, no growth defect was observed in rich organic media. Without essential vitamins, a significant reduction in the growth of the auxotrophic strains results in a decrease of the formation of T-2 toxin and diacetoxyscirpenol. In addition, all analysed F. langsethiae strains were distinguished into two subgroups based on PCR product sizes. According to our results, 26 and 23 strains of F. langsethiae belong to subgroups I and II respectively. We determined that the deletion in the intergenic spacer (IGS) region of the rDNA of F. langsethiae belonging to subgroup II is linked with temperature sensitivity and causes a decrease in strain growth at 30 °C. Four thiamine auxotrophic strains were found in subgroup I, while 21 biotin auxotrophic strains were detected in subgroups II. To the best of our knowledge, the spontaneous mutations in F. langsethiae observed in the present work have not been previously reported.

High-sensitivity chemiluminescent immunoassay investigation and application for the detection of T-2 toxin and major metabolite HT-2 toxin

BACKGROUND

T-2 toxin is a widely distributed mycotoxin in cereals. HT-2 toxin is the major metabolite, which is also a contaminant in cereals. T-2 toxin and HT-2 toxin have been identified as having carcinogenic, hepatotoxic, teratogenic and immunotoxic properties. To reduce the risk of contamination, a rapid, highly sensitive and inexpensive assay for the detection is required.

RESULTS

In this study a high-sensitivity chemiluminescent enzyme-linked immunoassay (CL-ELISA) of T-2 toxin and HT-2 toxin was developed. With the help of the chemiluminescent substrate, this protocol showed a highly sensitive character with an IC₅₀ as low as 33.28 ng mL^-1 and 27.27 ng mL^-1 for T-2 and HT-2, respectively. In addition, this method had no cross-reaction with other structurally related mycotoxins.

CONCLUSION

These results indicated that the developed CL-ELISA could be applied for the detection of T-2 toxin and HT-2 toxin in actual samples without complicated steps. © 2016 Society of Chemical Industry.

Growth Inhibition and Morphological Alteration of Fusarium sporotrichioides by Mentha piperita Essential Oil

OBJECTIVE

The aim of this study is to determine the phytochemical composition, antifungal activity of Mentha piperita essential oil (MPE) against Fusarium sporotrichioides.

METHODS

The phytochemical composition was conducted by gas chromatography mass spectrometry (GC MS) analysis and mycelia growth inhibition was determined by minimum inhibitory concentration (MIC) and minimum fungicidal concentration (MFC), the morphological characterization was observed by scanning electron microscopy. Finally, the membrane permeability was determined by the release of extracellular constituents, pH, and total lipid content.

RESULT

In GC MS analysis, 22 metabolites were identified such as menthol, l menthone, pulegone, piperitone, caryophyllene, menthol acetate, etc. The antifungal activity against targeted pathogen, with MIC and MFC 500 μg/mL and 1000 μg/mL, respectively. The MPE altered the morphology of F. sporotrichoides hyphae with the loss of cytoplasm content and contorted the mycelia. The increasing concentration of MPE showed increase in membrane permeability of F. sporotrichoides as evidenced by the release of extracellular constituents and pH with the disruption of cell membrane indicating decrease in lipid content of F. sporotrichoides.

CONCLUSION

The observed results showed that MPE exhibited promising new antifungal agent against Fusarium sporotrichioides.

SUMMARY

F. sporotrichioides, filamentous fungi contaminate to corn and corn--based productsF. sporotrichioides mainly responsible for the production of T-2 toxinPhytochemical composition was conducted by gas chromatography--mass spectrometry analysisMentha piperita essential oil (MPE) is commonly known as peppermintThe F. sporotrichioides growth was inhibited by MPE (minimum inhibitory concentration, minimum fungicidal concentration)Morphological observation by scanning electron microscope. Abbreviations Used: Cfu: Colony forming unit; DMSO: Dimethyl sulfoxide, °C: Degree celsius; F. Sporotrichoides: Fusarium sporotrichioides; EOs: Essential oils; M: Molar, g: Gram/gravity, mg: Milligram; μg: Microgram, ml: Milliliter; mm: Millimeter, min: Minutes; M. piperita: Mentha piperita, MIC: Minimum inhibitory concentration; MFC: Minimum fungicidal concentration; MAE: Mentha arvensis essential oil; Na2SO4: Sodium sulfate; pH: Potential Hydrogen; PDB: Potato Dextrose Broth; SEM: Scanning electron microscope.

Microbe-Mediated Control of Mycotoxigenic Grain Fungi in Stored Rice with Focus on Aflatoxin Biodegradation and Biosynthesis Inhibition

Rice contaminated with fungal species during storage is not only of poor quality and low economic value, but may also have harmful effects on human and animal health. The predominant fungal species isolated from rice grains during storage belong to the genera Aspergillus and Penicillium. Some of these fungal species produce mycotoxins; they are responsible for adverse health effects in humans and animals, particularly Aspergillus flavus, which produces the extremely carcinogenic aflatoxins. Not surprisingly, there have been numerous attempts to devise safety procedure for the control of such harmful fungi and production of mycotoxins, including aflatoxins. This review provides information about fungal and mycotoxin contamination of stored rice grains, and microbe-based (biological) strategies to control grain fungi and mycotoxins. The latter will include information regarding attempts undertaken for mycotoxin (especially aflatoxin) bio-detoxification and microbial interference with the aflatoxin-biosynthetic pathway in the toxin-producing fungi.

A non-linear model for temperature-dependent sporulation and T-2 and HT-2 production of Fusarium langsethiae and Fusarium sporotrichioides

This research has produced new quantitative data on the sporulation and T-2+HT-2 toxin production that could be further integrated to develop a comprehensive disease or toxin prediction model for Fusarium langsethiae and Fusarium sporotrichioides. Experiments were conducted to determine the effect of temperature or incubation time on sporulation and the effect of temperature on T-2+HT-2 toxin production of strains of the two species. F. sporotrichioides demonstrated a preference for higher temperatures than F. langsethiae during sporulation; the optimum temperature was 24.5 ± 0.7 °C for F. langsethiae and 32.3 ± 2.1 °C for F. sporotrichioides, according to the Beta equation fitted to the data. The dynamics of sporulation over different incubation times were fitted by a Gompertz function. The maximum spore production was estimated to be after 18 and 8 d incubation at optimum temperatures for F. langsethiae and F. sporotrichioides, respectively. F. sporotrichioides produced more T-2+HT-2 than F. langsethiae. The best fit of the effect of temperature on T-2+HT-2 production in wheat grains was obtained with a Beta equation showing an optimum temperature of 14.7 ± 0.8 °C for F. langsethiae and 12.1 ± 0.2 °C for F. sporotrichioides. The optimum temperature for mycotoxin production was lower than for sporulation.

Toxicity and oxidative stress induced by T-2 toxin and HT-2 toxin in broilers and broiler hepatocytes

T-2 and HT-2 toxins belong to mycotoxins which are found in human foods and animal chow. We investigated the toxicity and oxidative stress induced by T-2/HT-2 in broilers and chicken hepatocytes. Maize cultures of Fusarium poae was fed to broilers for 42 d, and the physiological index, biochemical index and expression of mRNAs related to oxidative stress were analyzed. Chicken hepatocytes were treated with different levels of T-2/HT-2, and the following parameters were detected: cell viability, GSH and MDA concentration, LDH leakage, activities of ALT/AST, ROS, GSH-PX, SOD and CAT, and expression of mRNA related to oxidative stress. In vivo, high levels of mycotoxins (4 mg/kg T-2 and 0.667 mg/kg HT-2) in feed caused significant reductions in body weight, weight gain, and serum total protein, and significant increases in feed conversion ratio, ALP, ALT/AST activities, and expression of mRNA related to oxidative stress. In vitro, cells treated with T-2/HT-2 showed reductions of GSH concentration and significant increases in LDH leakage, ALT/AST ROS, GSH-PX, SOD and CAT activities, MDA concentration, and expression of mRNA related to oxidative stress. Consequently, F. poae culture material and T-2/HT-2 induced toxicity and oxidative stress in vivo and in vitro, respectively.

Natural incidence of zearalenone in Croatian pig feed, urine and meat in 2014

The aim of this study was to determine the levels of zearalenone (ZEN) in different feed materials and feedstuffs for pigs, as well as in pig urine and pig meat following contaminated feed consumption. In total, 253 feed material and feedstuff samples were collected from Croatian pig farms. The results revealed the presence of ZEN in significant concentrations, the maximal being found in maize (5522 µg/kg), wheat (3366 µg/kg) and pig fattening feed (1949 µg/kg). In farms in which high feed contamination and pig hyperestrogenism were observed, samples of pig urine (n=30) and meat (n=30) were retrieved as well. The mean ZEN concentrations in pig urine and pig meat were 206±20.6 µg/L and 0.62±0.14 µg/kg, respectively. Despite high contamination of feedstuffs responsible for farmed pigs' intoxication, ZEN levels determined in pig meat were shown to be of little significance for human safety.

Toxicity induced by F. poae-contaminated feed and the protective effect of Montmorillonite supplementation in broilers

The T-2 and HT-2 toxins, the main metabolites of Fusarium poae, induce toxicity in broilers and accumulate in tissues. Consequently, during the breeding process of broilers, diets are frequently supplemented with physical adsorbents to protect birds against the toxicity induced by mycotoxins. In the present research, T-2 and HT-2 were produced in maize inoculated with F. poae. Mont, the strongest adsorbent based on in vitro adsorption ratios, was added to the contaminated diet. One-day-old chickens were randomly and equally divided into the following four groups: control diet group, Mont supplemented diet group, contaminated diet group and detoxification diet group. The experiment lasted for 42 days. Compared to the control group, the contaminated group showed significant decrease in body weight, feed intake and TP (P < 0.05), and marked increase in FCR, ALP, AST and ALT activity, T-2/HT-2 residues in the tissues and the relative expressions of apoptosis-related mRNAs (P < 0.05). Mont supplementation provided protection for the treated broilers in terms of performance, blood biochemistry, hepatic function, T-2/HT-2 residue of tissues and apoptosis. Therefore, Mont may be suitable as a detoxification agent for T-2/HT-2 in feed for broilers.

Liquid chromatography-tandem mass spectrometry method for toxicokinetics, tissue distribution, and excretion studies of T-2 toxin and its major metabolites in pigs

A rapid and sensitive high-performance liquid chromatography-tandem mass spectrometry (LC-MS/MS) method was developed and validated for quantitatively analyzing T-2 toxin and its major metabolites (HT-2 toxin and T-2 triol) in swine biological samples. For all matrices, liquid-liquid extraction (ethyl acetate or acetonitrile) and Varian Bond-Elut MycoSep cartridges for solid phase extraction were used for sample preparation. The analytes were separated via a Zorbax XDB-C18 column and were detected using LC-MS/MS with an electrospray ionization interface in positive ion mode. The resulting calibration curves offered satisfactory linearity (r(2)>0.992) within the test range. The limits of quantification for T-2 toxin, HT-2 toxin, and T-2 triol were 1ng/mL (μg/kg), 2ng/mL (μg/kg), and 5ng/mL (μg/kg), respectively. The recovery rates in different matrices ranged from 74.3% to 102.4%, and the interday and intraday precisions were all less than 10.2% for the target analytes. The developed method was successfully applied to toxicokinetics, tissue distribution, and excretion studies of T-2 toxin and its major metabolites after intravenous (i.v.) administration in pigs. The results provide important information for evaluating and controlling human exposure to residual T-2 toxin and its major metabolites in animal-derived food.

High specific monoclonal antibody production and development of an ELISA method for monitoring T-2 toxin in rice

This research produced a highly-specific and sensitive anti-T-2 toxin monoclonal antibody (mAb), and developed a rapid and sensitive competitive indirect enzyme-linked immunosorbent assay (ELISA) method for monitoring T-2 toxin in rice. The mAb showed a negligible cross-reactivity value (CR) to most of the mycotoxins, and it could specifically bind to T-2 toxin without other mycotoxins, including HT-2 toxin (CR value at 3.08%), which exhibited a similar structure to T-2 toxin. The limit of detection (LOD) value, measured by IC10, was 5.80 μg/kg. In spiked samples, mean recoveries ranged from 72.0% to 108.5% with intraday and interday variation less than 16.8 and 13.7%. This proposed protocol was significantly confirmed by a reliable ultrahigh performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) method and significant correlation was obtained.

Determination of T-2 and HT-2 toxins in food and feed: an update

Based on the recent scientific opinion of the European Food Safety Authority (EFSA) Panel on Contaminants in the Food Chain on the risks to human and animal health related to the presence of T-2 and HT-2 toxins in food and feed that was published by EFSA in the EFSA Journal, this article provides an update on the determination of these Fusarium mycotoxins. After a brief introduction into the chemistry of these toxins, both chromatographic and immuno-analytical methods are discussed for the determination of these type A trichothecenes. During the last decade, liquid chromatography with (tandem) mass spectrometry has become the most frequently used method for the determination of T-2 and HT-2 toxins, often within a multi-analyte approach. However, complex matrices and the resulting signal suppression effects, as observed particularly in electrospray-mass spectrometry methods owing to matrix effects, may require careful optimisation of clean-up, usage of matrix matched standards, or e.g. the use of internal standards. For specific purposes where extremely low limits of quantification are needed, e.g. for the analysis of duplicate diets, a dedicated gas chromatography method with multistage mass spectrometry has become available. Other novel analytical approaches to determine T-2 and HT-2 toxins in food and feed include biosensor-based methods in surface plasmon resonance and electrochemical formats, as well as DNA microchip assays. For rapid screening, several immunochemical methods (mostly ELISAs) have become available and some are sold as commercial test kits. Whereas these methods work fast, cross-reactivities with other trichothecenes can have an undesired effect on their accuracy. While proficiency tests including T-2 and HT-2 toxins have been carried out, none of the chromatographic or immunochemical methods have been formally validated in interlaboratory validation studies. There are no certified reference materials available for T-2 and HT-2 toxins.

Analysis of T-2 and HT-2 toxins in oats and other cereals by means of HPLC with fluorescence detection

Bearing in mind the high toxicity of T-2 and HT-2 toxins which occur in cereals (mainly in oats) EU plans legal limits for these mycotoxins. The occurrence data are insufficient because reliable and sensitive analysis methods are not available.A sensitive HPLC gradient method was developed which is applicable with common HPLC equipment (HPLC with fluorescence detection). After extraction of the toxins from sample matrix with methanol/water the diluted extracts were cleaned-up using immunoaffinity columns and then derivatized with 1-anthroylnitrile/DMAP. The T-2 and HT-2 toxins were separated from peaks of the cereal matrix and derivatization reagent by means of a relatively complex HPLC gradient method. The method was validated for oats, wheat, rye, barley, and maize. The recovery rates were in the range of 70-99%, the precision (RSDR) of 3-8%. The limits of detection of T-2 and HT-2 toxins were 1 μg/kg. A total of 119 samples of cereals and cereal products was analyzed according to the optimized method. The analyses of 54 samples of dehulled oats and of 11 samples of processed oat products from food industry had a contamination frequency of 100%. The contents (sum of T-2 and HT-2 toxins) amounted to 3 to 174 μg/kg for the dehulled oats and to 4 to 48 μg/kg for the processed oat products. 29 samples of maize and maize products had a contamination frequency of 80% (2-106 μg/kg in the sum of T-2 and HT-2 toxins). In the samples of wheat and barley the toxins were detected only occasionally (contents: 1-10 μg/kg), in rye not at all.

Trichothecenes and zearalenone production by Fusarium equiseti and Fusarium semitectum species isolated from Argentinean soybean

Fusarium equiseti and Fusarium semitectum represent the most abundant species in the Fusarium complex isolated from flowers, soybean pods and seeds in Argentina. The aim of the present study was to assess the production of major type A and type B trichothecenes (diacetoxyscirpenol, neosolaniol, T-2 toxin and HT-2 toxin, nivalenol, deoxynivalenol) and zearalenone by 40 F. equiseti and 22 F. semitectum isolates on rice culture. Mycotoxins were determined by HPLC with fluorescence detection after derivatisation with 1-anthronylnitrile for type A trichothecenes (i.e. diacetoxyscirpenol, neosolaniol, T-2 toxin and HT-2 toxin), by HPLC with UV detection for type B trichothecenes (i.e. nivalenol and deoxynivalenol), and by TLC for zearalenone. A total of 22 of 40 F. equiseti isolates produced diacetoxyscirpenol, nivalenol and ZEA alone or in combination, whereas only two of 20 F. semitectum isolates were nivalenol and ZEA producers. Both Fusarium species did not produce any deoxynivalenol, neosolaniol, T-2 toxin and HT-2 toxin. The variable retention in toxigenicity displayed by both fungal species suggests that these species have a saprophytic lifestyle in the soybean agroecosystem in Argentina.

Contamination level of T-2 and HT-2 toxin in cereal crops from Aba area in Sichuan Province, China

The contamination level of T-2 and HT-2 toxin in cereal crops from Aba area in Sichuan Province of China was investigated by rapid liquid chromatography-tandem mass spectrometry (HPLC-MS/MS). The results revealed the high incidence of T-2 and HT-2 toxin and relatively low contamination level in the samples. The incidence of HT-2 toxin was 49.74% and its average level was 3.746 μg/kg. The incidence of toxin was 11.64% and the average level was 0.565 μg/kg. The maximum of T-2 and HT-2 toxin concentration was 3.332 and 34.510 μg/kg, respectively. In addition, contaminated samples not only included homegrown products, but included external purchased rice and flour, which may be attributed to bad storage environment and sanitary conditions.

Mycotoxin production of Fusarium langsethiae and Fusarium sporotrichioides on cereal-based substrates

The present study investigated and compared the mycotoxin production of two Fusarium species, F. sporotrichioides and F. langsethiae, isolated from grain samples. Fusarium strains were cultivated at 25°C for 7 days on two types of solid media, i.e. rice-flour and cereal-flour agar. Toxins produced were measured after the incubation period with a multi-mycotoxin method based on liquid chromatography-tandem mass spectrometry (LC-MS/MS). Both F. sporotrichioides and F. langsethiae synthesised type-A trichothecenes, i.e. T-2 and HT-2 toxins, diacetoxyscirpenol (DAS) and neosolaniol (NEO). In addition, both species could be verified as beauvericin producers. The toxin production occurred in both cereal-based assays but was more predominant on the carbohydrate-rich rice-flour medium. The two species were potent producers of T-2 toxin, the highest amounts measured being at a level of 20,000 μg/kg after 7 days' incubation. Differences between the species were observed regarding the quantitative production of the other trichothecenes: F. sporotrichioides was a more prolific producer of HT-2 toxin and beauvericin, whereas F. langsethiae produced higher amounts of DAS and NEO. On rice-flour assay, the toxin production was monitored during the growth period. The production started rapidly at an early growth phase and several toxins could be detected already after the 1st day of incubation, the highest concentrations being at mg/kg level. The results also indicated that the biosynthesis by F. sporotrichioides and F. langsethiae shifted towards the other type-A trichothecenes at the expense of T-2 toxin at the end of the cultivation.

T-2 toxin, a trichothecene mycotoxin: review of toxicity, metabolism, and analytical methods

This review focuses on the toxicity and metabolism of T-2 toxin and analytical methods used for the determination of T-2 toxin. Among the naturally occurring trichothecenes in food and feed, T-2 toxin is a cytotoxic fungal secondary metabolite produced by various species of Fusarium. Following ingestion, T-2 toxin causes acute and chronic toxicity and induces apoptosis in the immune system and fetal tissues. T-2 toxin is usually metabolized and eliminated after ingestion, yielding more than 20 metabolites. Consequently, there is a possibility of human consumption of animal products contaminated with T-2 toxin and its metabolites. Several methods for the determination of T-2 toxin based on traditional chromatographic, immunoassay, or mass spectroscopy techniques are described. This review will contribute to a better understanding of T-2 toxin exposure in animals and humans and T-2 toxin metabolism, toxicity, and analytical methods, which may be useful in risk assessment and control of T-2 toxin exposure.

Influence of barley malting operating parameters on T-2 and HT-2 toxinogenesis of Fusarium langsethiae, a worrying contaminant of malting barley in Europe

The fungus Fusarium langsethiae, exclusively described in Europe at present, seems to have taken the place of other Fusarium species in barley fields over the last 5 years. It has proved to be a highly toxic type-A trichothecene producer (T-2 and HT-2 toxins). The aim of this work was to study the ecotoxinogenesis of this fungus the better to identify and manage the health risk it may pose during the beer manufacturing process. The influence of temperature and water activity on its growth rate and production of toxins are particularly assessed from a macroscopic point of view. Different cultures were grown on sterilized rehydrated barley with a water activity between 0.630 and 0.997 and a temperature ranging from 5 to 35 degrees C. Biomass specific to F. langsethiae and T-2 and HT-2 toxins were quantified by real-time polymerase chain reaction and liquid chromatography-mass spectrometry, respectively. It appears that the optimal temperature and water activity for F. langsethiae toxinogenesis are 28 degrees C and 0.997. This fungus was able to produce 2.22 g kg(-1) of these toxins in 16 days on barley in optimal production conditions. The malting process seems to be a critical step because, in its temperature range, specific production was six times higher than under optimal temperatures for fungus growth. In the short-term, this work will help redefine the process conditions for malting. In the medium-term, the results will contribute to the development of a molecular tool to diagnose the presence of this contaminant and the detection of the toxins in barley, from fields to the end product.

Temperature and water activity effects on production of T-2 and HT-2 by Fusarium langsethiae strains from north European countries

This study has examined the effect of ecophysiological factors, water activity (a(w), 0.995-0.90) and temperature (10-37 °C), on the T-2 and HT-2 toxins production by Fusarium langsethiae. Two dimensional profiles for optimum and marginal conditions have been built for two strains from each of four northern European countries (UK, Norway, Sweden, Finland) on an oat-based medium. This showed that the optimum a(w) and temperature conditions for T-2 + HT-2 production was between 0.98-0.995, and 20-30 °C respectively. Kruskal-Wallis analysis of ranks showed a statistically significant differences between the different a(w) levels examined (P < 0.001) but no significant effect of the temperatures examined. The ratio of HT-2/T-2 was investigated and non-uniform distribution of HT-2 toxin was found under different ecological conditions. No statistically significant differences were found for the mean toxin production between strains from the different countries. Intra-strain differences in toxin production was only found for those from Finland (P-value = 0.0247). The growth/no growth and toxin/no toxin conditions in relation to a(w) x temperature have been constructed for the first time. This knowledge will be useful in developing prevention strategies to minimise T-2 and HT-2 toxin contamination by strains of F. langsethiae on important small grain cereals.