Alternaria toxins alternariol and alternariol monomethyl ether in grain foods in Canada

Development of a high-throughput UHPLC-MS/MS method for the analysis of Fusarium and Alternaria toxins in cereals and cereal-based food

A QuEChERS (quick, easy, cheap, effective, rugged, and safe)-based multi-mycotoxin method was developed, analyzing 24 (17 free and 7 modified) Alternaria and Fusarium toxins in cereals via ultrahigh-performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS). A modified QuEChERS approach was optimized for sample preparation. Quantification was conducted using a combination of stable isotope dilution analysis (SIDA) for nine toxins and matrix-matched calibration for ten toxins. Quantification via a structurally similar internal standard was conducted for four analytes. Alternariol-9-sulfate (AOH-9-S) was measured qualitatively. Limits of detection (LODs) were between 0.004 µg/kg for enniatin A1 (ENN A1) and 3.16 µg/kg for nivalenol (NIV), while the limits of quantification were between 0.013 and 11.8 µg/kg, respectively. The method was successfully applied to analyze 136 cereals and cereal-based foods, including 28 cereal-based infant food products. The analyzed samples were frequently contaminated with Alternaria toxins, proving their ubiquitous occurrence. Interestingly, in many of those samples, some modified Alternaria toxins occurred, mainly alternariol-3-sulfate (AOH-3-S) and alternariol monomethyl ether-3-sulfate (AME-3-S), thus highlighting the importance of including modified mycotoxins in the routine analysis as they may significantly add to the total exposure of their parent toxins. Over 95% of the analyzed samples were contaminated with at least one toxin. Despite the general contamination, no maximum or indicative levels were exceeded.

Identification of mycotoxins in yogurt samples using an optimized QuEChERS extraction and UHPLC-MS/MS detection

Yogurt, a milk-derived product, is susceptible to mycotoxin contamination. While various methods have been developed for the analysis of dairy products, only a few have been specifically validated for yogurt. In addition, these methods are primarily focus on detecting aflatoxins and zearalenone. This study aimed to conduct a preliminary investigation into the presence of regulated, emerging, and modified mycotoxins in natural and oat yogurts available in the Spanish market. For this, a QuEChERS-based extraction method was optimized and then validated to detect and quantify 32 mycotoxins using ultra-high-performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS). The method was in-house validated for the analysis of natural and oat yogurt in terms of linearity, matrix effect, sensitivity, accuracy, and precision. Satisfactory performance characteristics were achieved; for most of the analytes, LOQs were lower than 2 ng/g, and recoveries ranged from 60 to 110% with a precision, expressed as the relative standard deviation of the recovery, lower than 15%. Subsequently, the validated method was applied to analyze commercial yogurt samples, revealing a notable incidence of beauvericin and enniatins, with some analogues found in up to 100% of the samples. Alternariol methyl ether was also frequently found, appearing in 50% of the samples. Additionally, the study identified regulated toxins such as fumonisins, ochratoxin A , and HT-2 toxin. These results provide new incidence data in yogurt, raising concerns about potential health risks for consumers.

Comprehensive identification and risk assessment of regulated and emerging mycotoxins in infant foods and related raw materials and risk management advice: A case study of an infant food company in China

This study evaluated muti-mycotoxins in 199 samples including processed infant foods and raw materials collected randomly from an infant food company and assessed their role in dietary exposure in infants and young children via probabilistic risk assessment. Approximately 79.6 % (74/93) of the processed infant foods and 65.1 % (69/106) of the raw materials were contaminated by mycotoxins, with a mean occurrence level of 3.66-321.8 µg/kg. Deoxynivalenol (DON) and tenuazonic acid (TeA) were the more prevalent mycotoxins detected, based on their higher frequencies and levels across samples. Co-occurrence of more than two mycotoxins was detected in 61.3 % (57/93) of the processed infant foods and 53.8 % (57/106) of the raw materials. Wheat flour and derived products (e.g., infant noodles and infant biscuits) were contaminated with higher contamination levels and a greater variety of mycotoxins than other samples (e.g., infant cereal and rice grains). The estimated daily exposure to OTA, DON, ZEN, and TEN was lower than the corresponding reference health-based guidance values, indicating acceptable health risks. However, the estimated dietary exposure to alternariol monomethyl ether (AME), alternariol (AOH), and tenuazonic acid (TeA) exceeded the corresponding thresholds of toxicological concern values, indicating potential dietary intake risks. Among the various samples, cereals and cereal-based infant foods emerged as the primary contributors to mycotoxin exposure. Further research is advised to address the uncertainties surrounding the toxicity associated with emerging Alternaria mycotoxins and to conduct cumulative risk assessments concerning multiple mycotoxin exposure in infants and young children.

Genotoxic and Mutagenic Effects of the Alternaria Mycotoxin Alternariol in Combination with the Process Contaminant Acrylamide

Humans are constantly exposed to mixtures of different xenobiotics through their diet. One emerging concern is the Alternaria mycotoxin alternariol (AOH), which can occur in foods typically contaminated by the process contaminant acrylamide (AA). AA is a byproduct of the Maillard reaction produced in carbohydrate-rich foods during thermal processing. Given the genotoxic properties of AOH and AA as single compounds, as well as their potential co-occurrence in food, this study aimed to assess the cytotoxic, genotoxic, and mutagenic effects of these compounds in combination. Genotoxicity was assessed in HepG2 cells by quantifying the phosphorylation of the histone γ-H2AX, induced as a response to DNA double-strand breaks (DSBs). Mutagenicity was tested in Salmonella typhimurium strains TA98 and TA100 by applying the Ames microplate format test. Our results showed the ability of AOH and AA to induce DSBs and increase revertant numbers in S. typhimurium TA100, with AOH being more potent than AA. However, no synergistic effects were observed during the combined treatments. Notably, the results of the study suggest that the compounds exert mutagenic effects primarily through base pair substitutions. In summary, the data indicate no immediate cause for concern regarding synergistic health risks associated with the consumption of foods co-contaminated with AOH and AA.

Mechanisms of Alternaria pathogenesis in animals and plants

Alternaria species are cosmopolitan fungi darkly pigmented by melanin that infect numerous plant species causing economically important agricultural spoilage of various food crops. Alternaria spp. also infect animals, being described as entomopathogenic fungi but also infecting warm-blooded animals, including humans. Their clinical importance in human health, as infection agents, lay in the growing number of immunocompromised patients. Moreover, Alternaria spp. are considered some of the most abundant and potent sources of airborne sensitizer allergens causing allergic respiratory diseases, as severe asthma. Among the numerous strategies deployed by Alternaria spp. to attack their hosts, the production of toxins, carrying critical concerns to public health as food contaminant, and the production of hydrolytic enzymes such as proteases, can be highlighted. Alternaria proteases also trigger allergic symptoms in individuals with fungal sensitization, acting as allergens and facilitating antigen access to the host subepithelium. Here, we review the current knowledge about the mechanisms of Alternaria pathogenesis in plants and animals, the strategies used by Alternaria to cope with the host defenses, and the involvement Alternaria allergens and mechanisms of sensitization.

Survey and toxigenic abilities of Aspergillus, Fusarium, and Alternaria fungi from wheat and paddy grains in Shanghai, China

A systematic study was carried out on 638 wheat and paddy grains (including fresh and stored samples) collected in 2021 from Shanghai, China, to identify the major mycobiota and their toxigenic abilities. A total of 349 fungi, namely, 252 Fusarium, 53 Aspergillus, and 44 Alternaria, were characterized by morphological and molecular identification. Fusarium and Aspergillus were more frequently isolated in paddy with Fusarium sambucinum species complex and Aspergillus section flavi as the predominant species, respectively. The genus Alternaria was the most frequently isolated fungal species in wheat. The toxin-producing potentials of the identified fungi were further evaluated in vitro. Deoxynevalenol (DON) was produced by 34.5% of Fusarium isolates and zearalenone (ZEN) was produced by 47.6% of them, and one isolate also processed the abilities for fumonisin B1 (FB1), B2 (FB2), and B3 (FB3) productions. Aflatoxin B1 (AFB1), B2 (AFB2), and G1 (AFG1) were only generated by Aspergillus section flavi, with the production rate of 65.5%, 27.6%, and 13.8%, respectively. Alternariol (AOH) was the most prevalent Alternaria toxin, which could be produced by 95.5% of the isolates, followed by alternariol monomethyl ether (AME) (72.7%), altenuene (ALT) (52.3%), tenuazonic acid (TeA) (45.5%), tentoxin (TEN) (29.5%), and altenusin (ALS) (4.5%). A combinational analysis of mycobiota and toxigenic ability allowed us to provide comprehensive information about the production mechanisms of mycotoxins in wheat and paddy in a specific geographic area, and will be helpful for developing efficient prevention and control programs.

Mycotoxin source and its exposure causing mycotoxicoses

Mycotoxins are toxic compounds produced by fungi such as Aspergillus, Penicillium, Rhizopus, Fusarium spp., and mushrooms. They are present in the mycelium or in the spores of the fungus. They cause human health problems once ingested. This is common in countries with high ambient temperature and relative humidity such as in the tropical regions. The consumption of moldy food and feeds are injurious to people and animals. The linked acute and chronic diseases target organs in humans and animals. The clinical symptoms depend on the intrinsic toxic features of the mycotoxin, the quantity, and length of exposure. The diseases caused by ingesting mycotoxins are reffred as mycotoxicoses. Therefore, it is of interest to document known data on the mycotoxin source and its exposure causing human hazards leading to mycotoxicoses.

Probabilistic Risk Assessment of Combined Exposure to Deoxynivalenol and Emerging Alternaria Toxins in Cereal-Based Food Products for Infants and Young Children in China

Deoxynivalenol (DON) and emerging Alternaria toxins often co-occur in cereal-based products, but the current risk assessment is commonly conducted for only one type of mycotoxin at a time. Compared to adults, infants and young children are more susceptible to mycotoxins through food consumption, especially with cereal-based food products which are the main source of exposure. This study aimed to perform a probabilistic risk assessment of combined exposure to DON and three major Alternaria toxins, namely including alternariol monomethyl ether (AME), alternariol (AOH), and tenuazonic acid (TeA) through consumption of cereal-based foods for Chinese infants and young children. A total of 872 cereal-based food products were randomly collected and tested for the occurrence of DON and three major Alternaria toxins. The results on mycotoxin occurrence showed the DON, TeA, AOH, and AME was detected in 56.4%, 47.5%, 7.5%, and 5.7% of the samples, respectively. Co-contamination of various mycotoxins was observed in 39.9% of the analyzed samples. A preliminary cumulative risk assessment using the models of hazard index (HI) and combined margin of exposure (MoET) was performed on DON and Alternaria toxins that were present in cereal-based food products for infants and young children in China for the first time. The results showed that only 0.2% and 1.5%, respectively, of individuals exceeded the corresponding reference value for DON and TeA, indicating a low health risk. However, in the case of AME and AOH, the proportion of individuals exceeding the reference value was 24.1% and 33.5%, respectively, indicating the potential health risks. In the cumulative risk assessment of AME and AOH, both HI and MoET values indicated a more serious risk than that related to individual exposure. Further research is necessary to reduce the uncertainties that are associated with the toxicities of the Alternaria toxins and cumulative risk assessment methods.

Characteristics of Fungal Communities and Internal Mildew Occurrence during the Stages of Planting and Storing of Sunflower Seed in China

Internally mildewed sunflower seeds pose a significant risk to human health. To control internal mildew, it is imperative to study its source in the main production area of China, which has been little investigated. Here, high-throughput sequencing was used to characterize the fungal and fungus-seed communities. Alpha diversity and ANOSIM analyses showed mildew did not alter the fungal compositions significantly. STAMP analysis showed that the sunflower seeds were most vulnerable to internal mildew during the field-planting stage. Alternaria was the predominant mildew-causing pathogen of sunflower seeds for consumption, which may originate from seed transmission and colonize at the seed-development stage. Finally, only a few seeds developed internal mildew with a worrisome level of Alternaria contamination in the humid field climate. NMDS analysis showed that climatic factors also played important roles in shaping microbial change during storage, with a relative humidity (RH) of 67% being the critical threshold in normal-temperature warehouses. Internal mildew never occurred below the RH threshold for the microbial community structure, which hardly changed after an average storage duration. The results indicated that a combination of field management to combat Alternaria, pretreatment with 5 KGy γ-irradiation and drying at the time of storage will minimize or prevent internal mildew. This work also provides an empirical framework for studies of mildewing in other shelled seeds.

Fungal Species and Multi-Mycotoxin Associated with Post-Harvest Sorghum (Sorghum bicolor (L.) Moench) Grain in Eastern Ethiopia

Sorghum is the main staple food crop in developing countries, including Ethiopia. However, sorghum grain quantity and quality are affected by contaminating fungi both under field and post-harvest stage. The aim of the current study was to assessed fungal species and multi-mycotoxins associated with sorghum grain in post-harvest samples collected from eastern Ethiopia. Fungal genera of Aspergillus, Alternaria, Bipolaris, Fusarium, Mucor, Penicillium, and Rhizoctonia were recovered in the infected grain. A liquid chromatography-tandem mass spectrometric (LC-MS/MS) was used for quantification of multiple mycotoxins/fungal metabolites. Overall, 94 metabolites were detected and grouped into eight categories. All metabolites were detected either in one or more samples. Among major mycotoxins and derivatives, deoxynivalenol (137 μg/kg), zearalenone (121 μg/kg), ochratoxin A (115 μg/kg), and fumonisin B₁ (112 μg/kg) were detected with maximum concentrations, while aflatoxin B₁ had relatively lower concentrations (23.6 μg/kg). Different emerging mycotoxins were also detected, with tenuazonic acid (1515 μg/kg) occurring at the maximum concentration among Alternaria metabolites. Fusaric acid (2786 μg/kg) from Fusarium metabolites and kojic acid (4584 μg/kg) were detected with the maximum concentration among Fusarium and Aspergillus metabolites, respectively. Unspecific metabolites were recognized with neoechinulin A (1996 μg/kg) at the maximum concentration, followed by cyclo (L-Pro-L-Tyr) (574 μg/kg) and cyclo (L-Pro-L-Val) (410 μg/kg). Moreover, metabolites form other fungal genera and bacterial metabolites were also detected at varying levels. Apparently, the study revealed that sorghum grains collected across those districts were significantly contaminated with co-occurrences of several mycotoxins. Farmers should be the main target groups to be trained on the improved management of sorghum production.

Distinction of Alternaria Sect. Pseudoalternaria Strains among Other Alternaria Fungi from Cereals

Species of the genus Alternaria are ubiquitous and frequently isolated from various plants, including crops. There are two phylogenetically and morphologically close Alternaria sections: the relatively well-known Infectoriae and the rarely mentioned Pseudoalternaria. Currently, the latter includes at least seven species that are less studied and sometimes misidentified. To perform precise identification, two primers (APsF and APsR) were designed and a sect. Pseudoalternaria-specific PCR method was developed. Thirty-five Russian A. infectoria-like strains were then examined. Five strains were found to be the members of the sect. Pseudoalternaria. Additionally, specificity of the previously developed primer set (Ain3F and Ain4R) was checked. It was found to be highly specific for sect. Infectoriae and did not amplify sect. Pseudoalternaria DNA. Identification of strains of the sect. Pseudoalternaria was supported and refined by phylogenetic reconstruction based on analysis of two loci, the glyceraldehyde-3-phosphate dehydrogenase gene (gpd), and the plasma membrane ATPase gene (ATP). These fungi belonged to Alternaria kordkuyana and A. rosae, which were the first detection of those taxa for the Eastern Europe. Alternaria kordkuyana was isolated from cereal seeds and eleuthero leaves. Alternaria rosae was obtained from oat seed. All strains of sect. Pseudoalternaria were not able to produce alternariol mycotoxin, as well as the majority of A. sect. Infectoriae strains.

Natural Occurrence of Alternaria Fungi and Associated Mycotoxins in Small-Grain Cereals from The Urals and West Siberia Regions of Russia

Alternaria fungi dominate the grain microbiota in many regions of the world; therefore, the detection of species that are able to produce mycotoxins has received much attention. A total of 178 grain samples of wheat, barley and oat obtained from the Urals and West Siberia regions of Russia in 2017–2019 were included in the study. Grain contamination with Alternaria fungi belonging to sections Alternaria and Infectoriae was analysed using qPCR with specific primers. The occurrence of four mycotoxins produced by Alternaria, AOH, AME, TEN, and TeA, was defined by HPLC-MS/MS. Alternaria DNA was found in all analysed grain samples. The prevalence of DNA of Alternaria sect. Alternaria fungi (range 53 × 10⁻⁴–21,731 × 10⁻⁴ pg/ng) over the DNA of Alternaria sect. Infectoriae (range 11 × 10⁻⁴‒4237 × 10⁻⁴ pg/ng) in the grain samples was revealed. Sixty-two percent of grain samples were contaminated by at least two Alternaria mycotoxins. The combination of TEN and TeA was found most often. Eight percent of grain samples were contaminated by all four mycotoxins, and only 3% of samples were free from the analysed secondary toxic metabolites. The amounts varied in a range of 2–53 µg/kg for AOH, 3–56 µg/kg for AME, 3–131 µg/kg for TEN and 9–15,000 µg/kg for TeA. To our knowledge, a new global maximum level of natural contamination of wheat grain with TeA was detected. A positive correlation between the amount of DNA from Alternaria sect. Alternaria and TeA was observed. The significant effects of cereal species and geographic origin of samples on the amounts of DNA and mycotoxins of Alternaria spp. in grain were revealed. Barley was the most heavily contaminated with fungi belonging to both sections. The content of AOH in oat grain was, on average, higher than that found in wheat and barley. The content of TEN in the grain of barley was lower than that in wheat and similar to that in oat. The content of TeA did not depend on the cereal crop. The effect of weather conditions (summer temperature and rainfall) on the final fungal and mycotoxin contamination of grain was discussed. The frequent co-occurrence of different Alternaria fungi and their mycotoxins in grain indicates the need for further studies investigating this issue.

Emerging mycotoxins in infant and children foods: A review

A proper nutrition is crucial for children's healthy development. Regardless of the usual recommendations to follow a varied diet, some foods can be a source of toxic natural contaminants such as mycotoxins, potent secondary metabolites produced by filamentous fungi. In addition to the most well-known mycotoxins, many of which are subject to tight regulation regarding the maximum levels allowed in different types of food, there is a large group of mycotoxins, the so-called emerging mycotoxins, about which less knowledge has already been acquired, which have gradually been the target of interest from the scientific community due to their prevalence in most foodstuffs, particularly in cereals and cereal-based products. Alternariol and his metabolite alternariol mono-methyl ether, beauvericin, citrinin, culmorin, enniatins, ergot alkaloids, fusaproliferin, kojic acid, moniliformin, sterigmatocystin, tentoxin and tenuazonic acid are the most representative of them. The current review gathered the information of the last ten years that have been published on the levels of emerging mycotoxins in food products dedicated for infants and children. European Union countries are responsible for most of the reported studies, which showed levels that can reach hundreds of mg/kg.

Antimycotoxigenic Activity of Beetroot Extracts against Alternaria alternata Mycotoxins on Potato Crop

Alternaria species, mainly air-borne fungi, affect potato plants, causing black spots symptoms. Morphological identification, pathogenicity assessment, and internal transcribed spacer (ITS) molecular identification confirmed that all isolates were Alternaria alternata. The annotated sequences were deposited in GenBank under accession numbers MN592771–MN592777. HPLC analysis revealed that the fungal isolates KH3 (133,200 ng/g) and NO3 (212,000 ng/g) produced higher levels of tenuazonic acid (TeA) and alternariol monomethyl ether (AME), respectively. Beet ethanol extract (BEE) and beet methanol extract (BME) at different concentrations were used as antimycotoxins. BME decreased the production of mycotoxins by 66.99–99.79%. The highest TeA reduction rate (99.39%) was reported in the KH3 isolate with 150 µg/mL BME treatment. In comparison, the most effective AME reduction rate (99.79%) was shown in the NO3 isolate with 150 µg/mL BME treatment. In the same way, BEE application resulted in 95.60–99.91% mycotoxin reduction. The highest TeA reduction rate (99.91%) was reported in the KH3 isolate with 150 µg/mL BEE treatment, while the greatest AME reduction rate (99.68%) was shown in the Alam1 isolate with 75 µg/mL BEE treatment. GC-MS analysis showed that the main constituent in BME was the antioxidant compound 1-dodecanamine, n,n-dimethyl with a peak area of 43.75%. In contrast, oxirane, methyl- (23.22%); hexadecanoic acid, methyl ester (10.72%); and n-hexadecanoic acid (7.32%) were the main components in BEE found by GC-MS. They are probably antimicrobial molecules and have an effect on the mycotoxin in general. To our knowledge, this is the first study describing the antimycotoxigenic activity of beet extracts against A. alternata mycotoxins-contaminated potato crops in Egypt, aimed to manage and save the environment.

Natural Co-Occurrence of Multiple Mycotoxins in Unprocessed Oats Grown in Ireland with Various Production Systems

The natural co-occurrence of 42 mycotoxins was investigated in unprocessed oat grains grown in Ireland. The sample set included a total of 208 oat crops harvested during 2015–2016 and produced using conventional, organic, or gluten free farming systems. A range of different toxins was identified, including the major type A (neosolaniol, HT-2 and T-2 toxins, T-2 triol, and T-2-glucoside, co-occurring in 21 samples) and B trichothecenes (deoxynivalenol, nivalenol, and deoxynivalenol-3-glucoside), enniatins (B1, B, and A1, co-occurring in 12 samples), as well as beauvericin, alternariol, mycophenolic acid, and sterigmatocystin. The influences of sowing season, year, and production system were investigated, eventually indicating that the latter factor may have a higher impact than others on the production of certain mycotoxins in oats. The most frequently quantified compounds were HT-2 (51%) and T-2 (41%) toxins, with gluten free oats containing significantly lower concentrations of HT-2 compared to conventionally produced oats. Although the prevalence and concentrations of mycotoxin found in oat samples in this study should be substantially reduced by processing. However, as mycotoxin occurrence is clearly influenced by multiple factors, controlled field trials should be carried out to define optimal agronomic practices and mitigate mycotoxin production. Furthermore, this work highlights the need for regularly testing cereal-based foods with multi-residue analytical methods with wider specificities than the traditionally screened and regulated toxins, to generate knowledge on the occurrence of several mycotoxins that are, to date, rarely investigated.

Growth characterization and predictive behavior of Eurotium species in a feedstuff matrix

Animal feeds are characterized by low water activity values. Nevertheless, fungal contamination with Eurotium species are quite common, causing nutritional depletion, spoilage and economic losses. The aim of this work was to assess Eurotium amstelodami, E. chevalieri, E. repens and E. rubrum growth in a feed matrix at different conditions of water activity (0.71-0.97) and temperature (5, 15, 25, 30 and 37°C). It was found that Eurotium species are able to grow in a wide range of water activity and temperature in a short period of time (7 days) and faster than in synthetic media. Rosso and probabilistic models were applied in order to determine the limiting and optimum growth conditions as well as growth probability at certain combinations of environmental factors. Both models provided an accurate fit to the cardinal parameters and good performance for growth/no growth cases. This is the first report assessing the growth parameters of Eurotium species directly in animal feed. Data obtained in the present study is useful to predict and avoid Eurotium species growth in animal feed.

Mycotoxin Occurrence, Exposure and Health Implications in Infants and Young Children in Sub-Saharan Africa: A Review

Infants and young children (IYC) remain the most vulnerable population group to environmental hazards worldwide, especially in economically developing regions such as sub-Saharan Africa (SSA). As a result, several governmental and non-governmental institutions including health, environmental and food safety networks and researchers have been proactive toward protecting this group. Mycotoxins, toxic secondary fungal metabolites, contribute largely to the health risks of this young population. In SSA, the scenario is worsened by socioeconomic status, poor agricultural and storage practices, and low level of awareness, as well as the non-establishment and lack of enforcement of regulatory limits in the region. Studies have revealed mycotoxin occurrence in breast milk and other weaning foods. Of concern is the early exposure of infants to mycotoxins through transplacental transfer and breast milk as a consequence of maternal exposure, which may result in adverse health effects. The current paper presents an overview of mycotoxin occurrence in foods intended for IYC in SSA. It discusses the imperative evidence of mycotoxin exposure of this population group in SSA, taking into account consumption data and the occurrence of mycotoxins in food, as well as biomonitoring approaches. Additionally, it discusses the health implications associated with IYC exposure to mycotoxins in SSA.

Combination of Antimicrobial Starters for Feed Fermentation: Influence on Piglet Feces Microbiota and Health and Growth Performance, Including Mycotoxin Biotransformation in vivo

The aim of this study was to apply a combination of the microbial starters Lactobacillus uvarum LUHS245, Lactobacillus casei LUHS210, Pediococcus acidilactici LUHS29, and Pediococcus pentosaceus LUHS183 for feed fermentation and to evaluate the influence of fermentation on feed acidity and microbiological characteristics, as well as on the piglet feces microbiota, health, and growth performance. Additionally, mycotoxin biotransformation was analyzed, including masked mycotoxins, in feed and piglet feces samples. The 36-day experiment was conducted using 25-day-old Large White/Norwegian Landrace (LW/NL) piglets with an initial body weight of 6.9–7.0 kg, which were randomly distributed into two groups (in each 100 piglets): control group, fed with basal diet (based on barley, wheat, potato protein, soybean protein concentrate, and whey powder), and treated group, fed with fermented feed at 500 g kg⁻¹ of total feed. Compared to a commercially available lactic acid bacteria (LAB) combination, the novel LAB mixture effectively reduced feed pH (on average pH 3.65), produced a 2-fold higher content of L(+) lactic acid, increased viable LAB count [on average 8.8 log₁₀ colony-forming units (CFU) g⁻¹], and led to stable feed fermentation during the entire test period (36 days). Fecal microbiota analysis showed an increased number of probiotic bacteria in the treated group, particularly Lactobacillus, when compared with the control group at the end of experiment. This finding indicates that fermented feed can modify microbial profile change in the gut of pigs. In treated piglets' blood (at day 61), the serum high-density lipoprotein (HDL) cholesterol and triglycerides (TG) were significantly higher, but the levels of T4, glucose, K, alkaline phosphatase (AP), and urea were significantly decreased (p ≤ 0.05) compared with the control group. Mycotoxin analysis showed that alternariol monomethyl ether (AME) and altenuene were found in 61-day-old control piglets' feces and in fermented feed samples. However, AME was not found in treated piglets' feces. Feed fermentation with the novel LAB combination is a promising means to modulate piglets' microbiota, which is essential to improve nutrient absorption, growth performance, and health parameters. The new LAB composition suggests a novel dietary strategy to positively manipulate fermented feed chemicals and bio-safety and the piglet gut microbial ecology to reduce antimicrobials use in pig production and increase local feed stock uses and economical effectiveness of the process.

Chemotaxonomic Profiling of Canadian Alternaria Populations Using High-Resolution Mass Spectrometry

Alternaria spp. occur as plant pathogens worldwide under field and storage conditions. They lead to food spoilage and also produce several classes of secondary metabolites that contaminate the food production chain. From a food safety perspective, the major challenge of assessing the risk of Alternaria contamination is the lack of a clear consensus on their species-level taxonomy. Furthermore, there are currently no reliable DNA sequencing methods to allow for differentiation of the toxigenic potential of these fungi. Our objective was to determine which species of Alternaria exist in Canada, and to describe the compounds they make. To address these issues, we performed metabolomic profiling using liquid chromatography high-resolution mass spectrometry (LC-HRMS) on 128 Canadian strains of Alternaria to determine their chemotaxonomy. The Alternaria strains were analyzed using principal component analysis (PCA) and unbiased k-means clustering to identify metabolites with significant differences (p < 0.001) between groups. Four populations or 'chemotypes' were identified within the strains studied, and several known secondary metabolites of Alternaria were identified as distinguishing metabolites, including tenuazonic acid, phomapyrones, and altenuene. Though species-level identifications could not be concluded for all groups through metabolomics alone, A. infectoria was able to be identified as a distinct population.

Food Consumption Data as a Tool to Estimate Exposure to Mycoestrogens

Zearalenone and alternariol are mycotoxins produced by Fusarium and Alternaria species, respectively, that present estrogenic activity and consequently are classified as endocrine disruptors. To estimate the exposure of the Portuguese population to these two mycotoxins at a national level, a modelling approach, based on data from 94 Portuguese volunteers, was developed considering as inputs: i) the food consumption data generated within the National Food and Physical Activity Survey; and ii) the human biomonitoring data used to assess the exposure to the referred mycotoxins. Six models of association between mycoestrogens urinary levels (zearalenone, total zearalenone and alternariol) and food items (meat, cheese, and fresh-cheese, breakfast cereals, sweets) were established. Applying the obtained models to the consumption data (n = 5811) of the general population, the median estimates of the probable daily intake revealed that a fraction of the Portuguese population might exceed the tolerable daily intake defined for zearalenone. A reference intake value for alternariol is still lacking, thus the characterization of risk due to the exposure to this mycotoxin was not possible to perform. Although the unavoidable uncertainties, these results are important contributions to understand the exposure to endocrine disruptors in Portugal and the potential Public Health consequences.

Effect of Atmospheric Cold Plasma Treatments on Reduction of Alternaria Toxins Content in Wheat Flour

Beside Fusarium toxins, Alternaria toxins are among the most commonly found mycotoxins in wheat and wheat products. Currently, investigations of possibilities of reduction of Alternaria toxins in the wheat-processing chain are limited. Therefore, the aim of this study was to explore the potency of cold atmospheric plasma treatments, as a new non-thermal approach, for reduction of alternariol (AOH), alternariol monomethyl ether (AME) and tentoxin (TEN) content in spiked white wheat flour samples. Samples were treated with plasma generated in the air during 30 s to 180 s, with an increment step of 30 s, and at four varying distances from the cold plasma source (6 mm, 21 mm, 36 mm and 51 mm). The reduction of the Alternaria toxins content in samples after treatment was monitored by high performance liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS). The maximum reduction of the examined Alternaria toxins was obtained by treatment performed at 6 mm distance from the plasma source, lasting 180 s, resulting in reductions of 60.6%, 73.8% and 54.5% for AOH, AME and TEN, respectively. According to the obtained experimental results, five empirical models in the form of the second-order polynomials were developed for the prediction of AOH, AME and TEN reduction, as well as the temperature and the moisture content of the wheat flour, that gave a good fit to experimental data and were able to predict the response variables successfully. The developed second-order polynomial models showed high coefficients of determination for prediction of experimental results (between 0.918 and 0.961).

Purification, crystallization and anticancer activity evaluation of the compound alternariol methyl ether from endophytic fungi Alternaria alternata

AIMS

Medicinal plant-associated endophytic fungi are important sources of precious bioactive compounds, contributing more than 80% of the natural drugs for various ailments. The present study was aimed at evaluating the anticancer activity of the crystallized compound alternariol methyl ether (AME) against hepatocellular carcinoma (HCC) both in vitro and in vivo from an endophytic fungus residing in the medicinal plant Vitex negundo.

METHODS AND RESULTS

The secondary metabolites from the endophytic fungus Alternaria alternata MGTMMP031 were isolated. Purification and characterization of the compound was performed and the potential compound was identified as AME. The crystal structure of AME was unambiguously confirmed by X-ray analysis. AME has been checked for its antibacterial and anticancer properties which showed its effectiveness against various bacteria and demonstrated marked anti-proliferative activity against the human HCC cells (HUH-7) both in vitro and in vivo. Mode of actions included cell cycle arrest, reducing the level of markers enzymes of liver cancer and preventing tumour growth.

CONCLUSIONS

Alternariol methyl ether acts as a potential therapeutic target against HCC. The compound was isolated and the crystal structure was obtained for the first time from the endophytic fungus A. alternata MGTMMP031. In the present study, the crystallized structure of AME was obtained by slow evaporation technique. It can be concluded that AME acts as a potential therapeutic target against HCC.

SIGNIFICANCE AND IMPACT OF THE STUDY

Endophytic fungi residing in the medicinal plants have strong biological significance and bioactive compounds from these fungi provide better therapeutic targets against diseases.

Analysis of Mycotoxins Contamination in Poultry Feeds Manufactured in Selected Provinces of South Africa Using UHPLC-MS/MS

A total of 105 different types of poultry feed samples from South Africa were simultaneously analysed for the presence of 16 mycotoxins using ultra-high-performance liquid chromatography coupled to a triple quadrupole mass spectrometer (UHPLC-MS/MS). The data revealed the presence of 16 mycotoxins in the various poultry feed samples. Fumonisin B₁ (FB₁) was the most dominant recovered from 100% of samples analysed at concentrations ranging between 38.7 and 7125.3 µg/kg. This was followed by zearalenone (ZEN) (range: 0.1–429 µg/kg) and deoxynivalenol (DON) (range: 2.5–154 µg/kg). Samples were also found to be contaminated with fumonisin B₂ (FB₂) (range: 0.7–125.1 µg/kg), fumonisin B₃ (FB₃) (range: 0.1–125.1 µg/kg), α-zearalenol (α-ZEL) (range: 0.6–20 µg/kg ), β-zearalenol (β-ZEL) (range: 0.2–22.1 µg/kg), 3-acetyldeoxynivalenol (3-ADON) (range: 0.1–12.9 µg/kg) and 15-acetyldeoxynivalenol (15-ADON) (range: 1.7–41.9 µg/kg). Alternaria mycotoxin, i.e., Alternariol monomethyl ether (AME) was recovered in 100% of samples at concentrations that ranged from 0.3–155.5 µg/kg. Aflatoxins (AFs) had an incidence rate of 92% with generally low concentration levels ranging from 0.1–3.7 µg/kg. Apart from these metabolites, 2 type A trichothecenes (THs), i.e., HT-2 toxin (HT-2) (range: 0.2–5.9 µg/kg) and T-2 toxin (T-2) (range: 0.1–15.3 µg/kg) were also detected. Mycotoxin contamination in South African poultry feed constitutes a concern as correspondingly high contamination levels, such as those observed herein are likely to affect birds, which can be accompanied by severe health implications, thus compromising animal productivity in the country. Such exposures, primarily to more than one mycotoxin concurrently, may elicit noticeable synergistic and or additive effects on poultry birds.

Alternaria mycotoxins in grains from Albania: alternariol, alternariol monomethyl ether, tenuazonic acid and tentoxin

The presence of four Alternaria toxins in maize and wheat harvested in 2014 and 2015 in Albania was investigated. In total, 45 samples of maize and 71 samples of wheat were collected from the country’s main producing regions. The presence of alternariol (AOH), alternariol monomethyl ether (AME), tenuazonic acid (TeA) and tentoxin (TTX) was studied by an LC-MS/MS method. The incidence of Alternaria toxins in maize was 45.2% in the year 2014 and 7.1% in 2015, and the contamination rate in wheat was 82.9% in 2014 and 86.1% in 2015. Considering maize and wheat samples together, 65.2 and 64.0% of samples were contaminated by Alternaria toxins in the harvesting years 2014 and 2015, respectively. The occurrence rate was much higher in wheat than in maize, but the concentrations were higher in maize. The highest concentration of total Alternaria toxins in maize was 1,283 μg/kg (mean 243.0 μg/kg, median 110.2 μg/kg), while the maximum concentration in wheat was 175.7 μg/kg (mean 29.9 μg/kg, median 16.5 μg/kg). TeA was the major Alternaria mycotoxin detected. It was found in 70 out of 116 samples (60.3%). Chronic exposure of the adult population in Albania to Alternaria toxins through cereal consumption was assessed by the estimated daily intake (EDI) taking into account daily consumption of wheat and maize of 380 and 4.9 g, respectively. The main contribution to chronic dietary exposure was by TeA originating from wheat, with EDIs of 88.6-94.1 ng/kg body weight (bw) per day in 2014 and 152.7-155.5 ng/kg bw per day in 2015. TTX EDIs were 7.8- 34.0 and 10.6-38.7 ng/kg bw per day in 2014 and 2015, respectively. The contribution of AOH and AME originating from wheat was 0-31.7 ng/kg bw per day. The contribution of Alternaria toxins through maize consumption was significantly lower.

Quantitation of Six Alternaria Toxins in Infant Foods Applying Stable Isotope Labeled Standards

Alternaria fungi are widely distributed saprophytes and plant pathogens. As pathogens, Alternaria fungi infect crops and vegetables and cause losses in the fields and during postharvest storage. While farmers suffer from declining yields, consumers are endangered by the formation of secondary metabolites, because some of these exhibit a pronounced toxicological potential. The evaluation of the toxicological capabilities is still ongoing and will contribute to a valid risk assessment. Additionally, data on the incidence and the quantity of Alternaria mycotoxins found in food products is necessary for dietary exposure evaluations. A sensitive LC-MS/MS method for the determination of the Alternaria mycotoxins alternariol (AOH), alternariol monomethylether (AME), tentoxin (TEN), altertoxin I (ATX I), alterperylenol (ALTP), and tenuazonic acid (TA) was developed. AOH, AME, and TA were quantified using stable-isotopically labeled standards. TEN, ATX I, and ALTP were determined using matrix matched calibration. The developed method was validated by using starch and fresh tomato matrix and resulted in limits of detection ranging from 0.05 to 1.25 μg/kg for starch (as a model for cereals) and from 0.01 to 1.36 μg/kg for fresh tomatoes. Limits of quantification were determined between 0.16 and 4.13 μg/kg for starch and between 0.02 and 5.56 μg/kg for tomatoes. Recoveries varied between 83 and 108% for starch and between 95 and 111% for tomatoes. Intra-day precisions were below 4% and inter-day precisions varied from 3 to 8% in both matrices. Various cereal based infant foods, jars containing vegetables and fruits as well as tomato products for infants were analyzed for Alternaria mycotoxin contamination (n = 25). TA was the most frequently determined mycotoxin and was detected in much higher contents than the other toxins. AME and TEN were quantified in many samples, but in low concentrations, whereas AOH, ATX I, and ALTP were determined rarely, among which AOH had higher concentration. Some infant food products were highly contaminated with Alternaria mycotoxins and the consumption of these individual products might pose a risk to the health of infants. However, when the mean or median is considered, no toxicological risk was obvious.

Alternaria species associated to wheat black point identified through a multilocus sequence approach

Black point is one of the most important wheat disease and its incidence is increasing worldwide due to climate change too. Among the fungal genera that can cause black point, Alternaria is one of the predominant genus, often associated with mycotoxin contamination. The correct identification is the baseline for prevention and control of the disease. Taxonomy of the genus Alternaria is not completely clear yet, since its species can be differentiated for few morphological traits and, in some cases, also molecular phylogeny is not very effective in establishing species boundaries. In this study, one-hundred sixty-four strains, isolated from wheat kernels affected by black point sampled worldwide, were analyzed in order to assess their identity. Sequences of elongation factor, β-tubulin, glyceraldehyde-3-phosphate dehydrogenase and allergen alt-a1 genes were used to identify the variability of this population and their phylogenetic relationships. Isolates were grouped in two main clades: the Alternaria section, including A. alternata, A. tenuissima and A. arborescens species, and the Infectoriae section, that includes the two species A. infectoria and A. triticina. Comparison of isolates according with their area of isolation did not show a correlation between phylogeny and geographic origin. Indeed, the isolates grouped on the base of only their phylogenetic relationship. Due to the data arisen by our study, we strongly recommend a multilocus sequence approach to define Alternaria species, based on common genes and procedures to be unanimously shared by scientific community dealing with Alternaria genus. Moreover, we suggest that A. alternata, A. tenuissima, A. turkisafria and A. limoniasperae species would be merged in the defined species A. alternata. Finally we recommend to consider a taxonomic re-evaluation of the Infectoriae section that, for the morphology, sexuality, genetic and mycotoxin profile of the species included, could be defined as different fungal genus from Alternaria.

Alternaria toxins in Argentinean wheat, bran, and flour

Alternaria species have been reported to infect a wide variety of vegetables, fruits, and cereal crops. Wheat is one of the most consumed cereal worldwide. A sensitive HPLC-DAD methodology was applied to quantify alternariol (AOH), alternariol methyl ether (AME) and tenuazonic acid (TeA) in 65 samples of whole wheat, bran, and flour. The extraction methodology allowed extracting the three toxins simultaneously. Limits of detection in wheat were 3.4, 4.5, and 0.5 µg kg^-1 for AOH, AME and TeA, respectively. For bran, these data were 3.1, 4.5, and 12 µg kg^-1 and for flour 50, 70, and 14 µg kg^-1, respectively. The studied recoveries were higher than 70% and RSD was below 10%. Wheat and bran samples showed low AOH and AME contamination compared to TeA. The averages levels found for TeA in wheat, bran and flour were 19,190, 16,760, and 7360 µg kg^-1, respectively.

Simple Approach for the Rapid Detection of Alternariol in Pear Fruit by Surface-Enhanced Raman Scattering with Pyridine-Modified Silver Nanoparticles

A simple method based on surface-enhanced Raman scattering (SERS) was developed for the rapid determination of alternariol (AOH) in pear fruits using an easily prepared silver-nanoparticle (AgNP) substrate. The AgNP substrate was modified by pyridine to circumvent the weak affinity of the AOH molecules to the silver surface and to improve the sensitivity of detection. Quantitative analysis was performed in AOH solutions at concentrations ranging from 3.16 to 316.0 μg/L, and the limit of detection was 1.30 μg/L. The novel method was also applied to the detection of AOH residues in pear fruits purchased from the market and in pear fruits that were artificially inoculated with Alternaria alternata. AOH was not found in any of the fresh fruit, whereas it resided in the rotten and inoculated fruits. Finally, the SERS method was cross validated against HPLC. It was revealed that the SERS method has great potential utility in the rapid detection of AOH in pear fruits and other agricultural products.

Isolation, characterization and toxicological potential of Alternaria-mycotoxins (TeA, AOH and AME) in different Alternaria species from various regions of India

Alternaria species produce various sorts of toxic metabolites during their active growth and causes severe diseases in many plants by limiting their productivity. These toxic metabolites incorporate various mycotoxins comprising of dibenzo-α-pyrone and some tetramic acid derivatives. In this study, we have screened out total 48 isolates of Alternaria from different plants belonging to different locations in India, on the basis of their pathogenic nature. Pathogenicity testing of these 48 strains on susceptible tomato variety (CO-3) showed 27.08% of the strains were highly pathogenic, 35.41% moderately pathogenic and 37.5% were less pathogenic. Phylogenetic analysis showed the presence of at least eight evolutionary cluster of the pathogen. Toxins (TeA, AOH and AME) were isolated, purified on the basis of column chromatography and TLC, and further confirmed by the HPLC-UV chromatograms using standards. The final detection of toxins was done by the LC-MS/MS analysis by their mass/charge ratio. The present study develops an approach to classify the toxicogenic effect of each of the individual mycotoxins on tomato plant and focuses their differential susceptibility to develop disease symptoms. This study represents the report of the natural occurrence and distribution of Alternaria toxins in various plants from India.

Occurrence of Regulated Mycotoxins and Other Microbial Metabolites in Dried Cassava Products from Nigeria

Dried cassava products are perceived as one of the potential sources of mycotoxin ingestion in human foods. Processing either contributes to the reduction of toxins or further exposes products to contamination by microorganisms that release metabolic toxins into the products. Thus, the prevalence of microbial metabolites in 373 processed cassava products was investigated in Nigeria. With the use of liquid chromatography tandem-mass spectrometry (LC-MS/MS) for the constituent analysis, a few major mycotoxins (aflatoxin B₁ and G₁, fumonisin B₁ and B₂, and zearalenone) regulated in food crops by the Commission of the European Union were found at concentrations which are toxicologically acceptable in many other crops. Some bioactive compounds were detected at low concentrations in the cassava products. Therefore, the exposure of cassava consumers in Nigeria to regulated mycotoxins was estimated to be minimal. The results provide useful information regarding the probable safety of cassava products in Nigeria.

AlternariaMycotoxins in Food and Feed: An Overview

Alternariais one of the major mycotoxigenic fungal genera with more than 70 reported metabolites.Alternariamycotoxins showed notably toxicity, such as mutagenicity, carcinogenicity, induction of DNA strand break, sphingolipid metabolism disruption, or inhibition of enzymes activity and photophosphorylation. This review reports on the toxicity, stability, metabolism, current analytical methods, and prevalence ofAlternariamycotoxins in food and feed through the most recent published research. Half of the publications were focused on fruits, vegetables, and derived products—mainly tomato and apples—while cereals and cereal by-products represented 38%. The most studied compounds were alternariol, alternariol methyl ether, tentoxin, and tenuazonic acid, but altenuene, altertoxins (I, II, and III), and macrosporin have been gaining importance in recent years. Solid-liquid extraction (50%) with acetonitrile or ethyl acetate was the most common extraction methodology, followed by QuEChERS and dilution-direct injection (both 14%). High- and ultraperformance liquid chromatography coupled with tandem mass spectrometry was the predominant determination technique (80%). The highest levels of alternariol and alternariol methyl ether were found in lentils, oilseeds, tomatoes, carrots, juices, wines, and cereals. Tenuazonic acid highest levels were detected in cereals followed by beer, while alternariol, alternariol methyl ether, tenuazonic acid, and tentoxin were found in legumes, nuts, and oilseeds.

Identification of six new Alternaria sulfoconjugated metabolites by high-resolution neutral loss filtering

RATIONALE

Many species of Alternaria damage important agricultural crops, including small grains and tomatoes. These fungi can produce a variety of secondary metabolites, some of which are toxic to humans and animals. Interest in screening for conjugated or 'modified' mycotoxins has increased because of their tendency to evade traditional analytical screening methods. Two sulfoconjugated Alternaria toxins have been reported and the potential exists for many more.

METHODS

One hundred and forty-eight Canadian strains of Alternaria spp., about half of them isolated from grain, were grown on Potato Dextrose Agar in Petri dishes for 7 days. Plugs of each strain were removed, extracted and screened by a rapid liquid chromatography (LC)/data-dependent tandem mass spectrometry (MS(2)) method in negative electrospray ionization mode. Data generated on an Orbitrap Q-Exactive mass spectrometer was processed by post-acquisition neutral loss filtering (NLF). Seven isolates that produced sulfoconjugates of known Alternaria toxins were selected for growth on three additional types of fermentation media.

RESULTS

Collision-induced dissociation of sulfoconjugated ions displayed a distinctive neutral loss of SO3 (79.957 Da) that was detected in the MS(2) datasets using post-acquisition NLF. A total of 108 of the 148 isolates screened produced sulfoconjugated metabolites on agar plates. Analysis of the seven isolates grown in liquid culture, on rice and Cheerios, led to the discovery of six new, two previously reported and 30 unidentified sulfoconjugated compounds.

CONCLUSIONS

NLF of HRMS(2) data from an Orbitrap Q-Exactive is a powerful tool for the rapid discovery of sulfoconjugated fungal metabolites. This technique could also be applied to the detection of other important conjugated mycotoxins such as glucosides. The majority of the Canadian isolates of Alternaria spp. studied produced sulfoconjugated metabolites, some of which had no known 'free' Alternaria precursor metabolite, indicating that they are possibly new metabolites. The advantage of sulfoconjugation to Alternaria spp. is unknown, and warrants further study into the mechanisms behind the sulfur assimilatory pathways.

Rapid detection of Fusarium wilt in basil (Ocimum sp.) leaves by desorption electrospray ionization mass spectrometry (DESI MS) imaging

A rapid method to unravel the spatial distribution ofFusarium/other pathogen-contamination in asymptomatic leaves under ambient conditions.