High Levels Of Fumonisins Research Articles

Financial losses due to fumonisin contamination in the Texas High Plains maize

Fumonisins are one of the main problems affecting maize production in the Texas High Plains (THP), where its agroclimatic conditions make it a perennial hotspot for mycotoxin contamination. In 2017, a fumonisin outbreak in the THP maize motivated stakeholders’ request to repeal a subsection of the Texas Administrative Code, §61.61(a)(7) (Fumonisin Rule), and its related Texas Feed Industry Memorandum (Memo 5–20), which previously permitted the blending of maize containing high fumonisin levels with maize containing ≥ 5 mg/kg under state authority, and pivot to FDA fumonisin guidance. Shortly after, the USDA Risk Management Agency (RMA's) reintroduced Discount Factors (DFs) in annual Special Provisions (SP) that outline price reductions related to fumonisin contamination in maize. In this research, we estimate the potential economic burden posed by these changes through a two-part approach. In part one, we construct a decision model that explores the final disposition of fumonisin-contaminated maize based on blending permissions, fumonisin levels, and crop insurance status. In part two, we estimate the economic impact by inserting output values of the decision model into financial equations that consider testing costs, transportation fees, and discounts from crop insurance and grain elevators when applicable. Our economic analysis projects that the financial losses during a THP crop year with high fumonisin levels could range from $15.1 to $135.5 million without the option to blend under conditions of the revised RMA discount schedule. Findings further highlight crop insurance as the most promising risk management strategy for farmers in areas susceptible to fumonisin contamination.

Underreported Human Exposure to Mycotoxins: The Case of South Africa.

South Africa (SA) is a leading exporter of maize in Africa. The commercial maize farming sector contributes to about 85% of the overall maize produced. More than 33% of South Africa’s population live in rural settlements, and their livelihoods depend entirely on subsistence farming. The subsistence farming system promotes fungal growth and mycotoxin production. This review aims to investigate the exposure levels of the rural population of South Africa to dietary mycotoxins contrary to several reports issued concerning the safety of South African maize. A systematic search was conducted using Google Scholar. Maize is a staple food in South Africa and consumption rates in rural and urban communities are different, for instance, intake may be 1–2 kg/person/day and 400 g/person/day, respectively. Commercial and subsistence maize farming techniques are different. There exist differences influencing the composition of mycotoxins in food commodities from both sectors. Depending on the levels of contamination, dietary exposure of South Africans to mycotoxins is evident in the high levels of fumonisins (FBs) that have been detected in SA home-grown maize. Other potential sources of exposure to mycotoxins, such as carryover effects from animal products and processed foods, were reviewed. The combined effects between FBs and aflatoxins (AFs) have been reported in humans/animals and should not be ignored, as sporadic breakouts of aflatoxicosis have been reported in South Africa. These reports are not a true representation of the entire country as reports from the subsistence-farming rural communities show high incidence of maize contaminated with both AFs and FBs. While commercial farmers and exporters have all the resources needed to perform laboratory analyses of maize products, the greater challenge in combatting mycotoxin exposure is encountered in rural communities with predominantly subsistence farming systems, where conventional food surveillance is lacking.

Multi-Mycotoxin Long-Term Monitoring Survey on North-Italian Maize over an 11-Year Period (2011-2021): The Co-Occurrence of Regulated, Masked and Emerging Mycotoxins and Fungal Metabolites.

Maize is considered one of the most susceptible crops to mycotoxin-producing fungi throughout the world, mainly belonging to the Fusarium spp. and Aspergillus spp. Maize is mainly used as animal feeds in Italy, as well as for human consumption, being essential for all the protected designation of origin (DOP) products. Our study investigated the occurrence of regulated mycotoxins in 3769 maize grain samples collected from 88 storage centers by the National Monitoring Network over an 11-year period (2011–2021). Moreover, an in-depth survey over a 4-year period, characterized by extremely different meteorological conditions, was conducted to investigate the co-occurrence of regulated, masked, and emerging mycotoxins. The survey confirmed that Fusarium spp. was the most frequent fungi and fumonisins were the main mycotoxins that were constantly detected in the different years and areas. Moreover, the areas characterized by high fumonisin levels were also the most prone to contamination by emerging mycotoxins produced by the same Fusarium species of the Liseola section. On the other hand, as a result of climatic changes, maize grains have also been affected by the increased frequency of aflatoxin accumulation. Deoxynivalenol, zearalenone, and other emerging mycotoxins produced by the same Fusarium species as the Discolor section occurred more abundantly in some areas in Northern Italy and in years characterized by predisposing meteorological conditions.

Fumonisins in African Countries.

Maize and other cereals are the commodities most contaminated with fumonisins. The maize acreage is increasing in Africa, and the maize harvest provides important foods for humans and feeds for domestic animals throughout the continent. In North Africa, high levels of fumonisins have been reported from Algeria and Morocco, while low levels have been detected in the rather few fumonisin analyses reported from Tunisia and Egypt. The West African countries Burkina Faso, Cameroon, Ghana, and Nigeria all report high levels of fumonisin contamination of maize, while the few maize samples analysed in Togo contain low levels. In Eastern Africa, high levels of fumonisin contamination have been reported from the Democratic Republic of Congo, Ethiopia, Kenya, Tanzania, and Uganda. The samples analysed from Rwanda contained low levels of fumonisins. Analysis of maize from the Southern African countries Malawi, Namibia, South Africa, Zambia, and Zimbabwe revealed high fumonisin levels, while low levels of fumonisins were detected in the few analyses of maize from Botswana and Mozambique.

Molecular Determination of Toxigenic Potential of Fusarium spp. Isolated from Seeds of Wheat (Triticum aestivum) Genotypes and Evaluation of Levels of Fumonisins in the Grains at Harvest in Three Major Wheat Producing Counties in Kenya

Infestation of cereals such as wheat by pathogenic Fusarium species (Fusarium spp.) is associated with over 25% weight loss of the grain and accumulation of hazardous mycotoxins. Potential management strategies against the pathogens include the development of more resistant wheat genotypes and the development of rapid and accurate Fusarium spp. identification methods, among other control measures. This study evaluated the toxigenic potential in populations of Fusarium spp. isolated from seeds of locally developed wheat genotypes and levels of fumonisins in the grains at harvest in three counties in Kenya. The sampling of the wheat grains took place between September 2016 and October 2017. Determination of toxigenic potential was PCR based using Tri13F/Tri13DONR and FUM1F/FUM1R specific primer pairs while detection of fumonisin levels was done using Total Fumonisin Assay 0.25/5.0 ELISA kit. Data were analyzed using ANOVA and the Tukey HSD test. FUM1 gene was detected in 60% of the Fusarium spp. analyzed. The distribution of the gene within the isolates across the three regions was as follows: Narok: 54%, Uasin Gishu: 25%, and Nakuru: 21%. Tri13DON gene was not detected in the assessed potential deoxynivalenol (DON) producers. Fumonisin levels in the wheat samples from the three counties were significantly different ( p < 0.001 ). The highest fumonisin levels, 9.6 ppm, occurred in 30.7% of the grains of the studied wheat genotypes. Relatively high fumonisin levels occurred in Njoro II, Eagle 10, Robin, and Korongo wheat genotypes with no significant difference at 0.05 confidence interval. In conclusion, the toxigenic potential amongst the Fusarium spp. studied was confirmed based on the occurrence of FUM1 gene and the detection of fumonisins in 76% of the sampled wheat grains. More research is recommended to ascertain the prevalence of the genes determining the production of DON and the other trichothecenes in Fusarium spp. prevalent in the developed wheat genotypes in the different agroecological regions in Kenya. In addition, the assessment of the occurrence and levels of the respectful mycotoxins also needs further research. These would provide additional information for the improvement of strategies put in place to manage the effects of the pathogenic Fusarium spp. in the crop and to ensure mycotoxin safety of the wheat food chain for both livestock and human consumption. It also shows the need for the development of more disease-resistant wheat varieties by wheat seed-producing companies.

Role of Sesamia nonagrioides and Ostrinia nubilalis as Vectors of Fusarium spp. and Contribution of Corn Borer-Resistant Bt Maize to Mycotoxin Reduction.

Maize expressing Cry1Ab insecticidal toxin (Bt maize) is an effective method to control Sesamia nonagrioides and Ostrinia nubilalis, the most damaging corn borers of southern Europe. In this area, maize is prone to Fusarium infections, which can produce mycotoxins that pose a serious risk to human and animal health, causing significant economic losses in the agrifood industry. To investigate the influence of corn borer damage on the presence of Fusarium species and their mycotoxins, Bt maize ears and insect-damaged ears of non-Bt maize were collected from commercial fields in three Bt maize growing areas in Spain, and differences in contamination were assessed. Additionally, larvae of both borer species were collected to evaluate their role as vectors of these molds. Non-Bt maize ears showed significantly higher presence of F. verticillioides, F. proliferatum, and F. subglutinans than Bt maize ears. For the first time, Fusarium species have been isolated from larvae of the two species. The most frequently found mycotoxins in ears were fumonisins, with non-Bt ears being significantly more contaminated than those of Bt maize. High levels of fumonisins were shown to correlate with the occurrence of corn borers in the ear and the presence of F. verticillioides and F. proliferatum.

Screening of Regulated and Emerging Mycotoxins in Bulk Milk Samples by High-Resolution Mass Spectrometry

In this work, a retrospective screening based on ultra-high-performance liquid chromatography (UHPLC) coupled with high-resolution mass spectrometry (HRMS) based on Orbitrap-Q-Exactive Focus™ was used to check the occurrence of regulated and emerging mycotoxins in bulk milk samples. Milk samples were collected from dairy farms in which corn silage was the main ingredient of the feeding system. The 45 bulk milk samples were previously analyzed for a detailed untargeted metabolomic profiling and classified into five clusters according to the corn silage contamination profile, namely: (1) low levels of Aspergillus- and Penicillium-mycotoxins; (2) low levels of fumonisins and other Fusarium-mycotoxins; (3) high levels of Aspergillus-mycotoxins; (4) high levels of non-regulated Fusarium-mycotoxins; (5) high levels of fumonisins and their metabolites. Multivariate statistics based on both unsupervised and supervised analyses were used to evaluate the significant fold-change variations of the main groups of mycotoxins detected when comparing milk samples from clusters 3, 4, and 5 (high contamination levels of the corn silages) with cluster 1 and 2 (low contamination levels of the corn silages). Overall, 14 compounds showed a significant prediction ability, with antibiotic Y (VIP score = 2.579), bikaverin (VIP score = 1.975) and fumonisin B2 (VIP score = 1.846) being the best markers. The k-means clustering combined with supervised statistics showed two discriminant groups of milk samples, thus revealing a hierarchically higher impact of the whole feeding system (rather than the only corn silages) together with other factors of variability on the final mycotoxin contamination profile. Among the discriminant metabolites we found some Fusarium mycotoxins, together with the tetrapeptide tentoxin (an Alternaria toxin), the α-zearalenol (a catabolite of zearalenone), mycophenolic acid and apicidin. These preliminary findings provide new insights into the potential role of UHPLC-HRMS to evaluate the contamination profile and the safety of raw milk to produce hard cheese.

Changes of Milk Metabolomic Profiles Resulting from a Mycotoxins-Contaminated Corn Silage Intake by Dairy Cows.

In this study, an untargeted metabolomics approach based on ultra-high-performance liquid chromatography coupled with high-resolution mass spectrometry (UHPLC-HRMS) was used for investigating changes in chemical profiles of cow milk considering diets based on mycotoxins-contaminated corn silages. For this purpose, 45 milk samples were classified into five clusters according to the corn silage contamination profile, namely (1) low levels of Aspergillus- and Penicillium-mycotoxins; (2) low levels of fumonisins and other Fusarium-mycotoxins; (3) high levels of Aspergillus-mycotoxins; (4) high levels of non-regulated Fusarium-mycotoxins; (5) high levels of fumonisins and their metabolites, and subsequently analyzed by UHPLC-HRMS followed by a multivariate statistical analysis (both unsupervised and supervised statistical approaches). Overall, the milk metabolomic profile highlighted potential correlations between the quality of contaminated corn silages (as part of the total mixed ration) and milk composition. Metabolomics allowed to identify 628 significant milk metabolites as affected by the five levels of corn silage contamination considered, with amino acids and peptides showing the highest metabolite set enrichment (134 compounds). Additionally, 78 metabolites were selected as the best discriminant of the prediction model built, possessing a variable importance in projection score >1.2. The average Log Fold-Change variations of the discriminant metabolites provided evidence that sphingolipids, together with purine and pyrimidine-derived metabolites were the most affected chemical classes. Also, metabolomics revealed a significant accumulation of oxidized glutathione in milk samples belonging to the silage cluster contaminated by emerging Aspergillus toxins, likely involved in the oxidative imbalance. These preliminary findings provide new insights into the potential role of milk metabolomics to provide chemical indicators of mycotoxins-contaminated corn silage feeding systems.

Co-Occurrence of Regulated and Emerging Mycotoxins in Corn Silage: Relationships with Fermentation Quality and Bacterial Communities.

Sixty-four corn silages were characterized for chemicals, bacterial community, and concentrations of several fungal metabolites. Silages were grouped in five clusters, based on detected mycotoxins, and they were characterized for being contaminated by (1) low levels of Aspergillus- and Penicillium-mycotoxins; (2) low levels of fumonisins and other Fusarium-mycotoxins; (3) high levels of Aspergillus-mycotoxins; (4) high levels of non-regulated Fusarium-mycotoxins; (5) high levels of fumonisins and their metabolites. Altersetin was detected in clusters 1, 3, and 5. Rugulusovin or brevianamide F were detected in several samples, with the highest concentration in cluster 3. Emodin was detected in more than 50.0% of samples of clusters 1, 3 and 5, respectively. Kojic acid occurred mainly in clusters 1 and 2 at very low concentrations. Regarding Fusarium mycotoxins, high occurrences were observed for FB3, FB4, FA1, whereas the average concentrations of FB6 and FA2 were lower than 12.4 µg/kg dry matter. Emerging Fusarium-produced mycotoxins, such as siccanol, moniliformin, equisetin, epiequisetin and bikaverin were detected in the majority of analyzed corn silages. Pestalotin, oxaline, phenopirrozin and questiomycin A were detected at high incidences. Concluding, this work highlighted that corn silages could be contaminated by a high number of regulated and emerging mycotoxins.

Natural Occurrence of Mycotoxin-Producing Fusaria in Market-Bought Peruvian Cereals: A Food Safety Threat for Andean Populations.

Consumption of cereals contaminated by mycotoxins poses health risks. For instance, Fumonisins B, mainly produced by Fusarium verticillioides and Fusarium proliferatum, and the type B trichothecene deoxynivalenol, typically produced by Fusarium graminearum, are highly prevalent on cereal grains that are staples of many cultural diets and known to represent a toxic risk hazard. In Peru, corn and other cereals are frequently consumed on a daily basis under various forms, the majority of food grains being sold through traditional markets for direct consumption. Here, we surveyed mycotoxin contents of market-bought grain samples in order to assess the threat these mycotoxins might represent to Peruvian population, with a focus on corn. We found that nearly one sample of Peruvian corn out of six was contaminated with very high levels of Fumonisins, levels mostly ascribed to the presence of F. verticillioides. Extensive profiling of Peruvian corn kernels for fungal contaminants could provide elements to refine the potential risk associated with Fusarium toxins and help define adapted food safety standards.

Multi-Mycotoxin Occurrence and Exposure Assessment Approach in Foodstuffs from Algeria.

A survey on 120 cereal samples (barley, maize, rice and wheat) from Algerian markets has been carried out to evaluate the presence of 15 mycotoxins (ochratoxin A, deoxynivalenol, fumonisin B1 and B2, T-2 and HT-2 toxins, zearalenone, fusarenon X, citrinin, sterigmatocystin, enniatins A, A1, B and B1, and beauvericin). With this purpose, a QuEChERS-based extraction and ultra-high performance liquid chromatography coupled to tandem mass spectrometry (UHPLC-MS/MS) were used. Analytical results showed that 78 cereal samples (65%) were contaminated with at least one toxin, while 50% were contaminated with three to nine mycotoxins. T-2 toxin, citrinin, beauvericin and deoxynivalenol were the most commonly found mycotoxins (frequency of 50%, 41.6%, 40.8% and 33.3%, respectively). Fumonisins (B1 + B2), enniatins B and B1, deoxynivalenol and zearalenone registered high concentrations (289–48878 µg/kg, 1.2–5288 µg/kg, 15–4569 µg/kg, 48–2055 µg/kg and 10.4–579 µg/kg, respectively). Furthermore, concentrations higher than those allowed by the European Union (EU) were observed in 21, 8 and 1 samples for fumonisins, zearalenone and deoxinivalenol, respectively. As a conclusion, the high levels of fumonisins (B1 + B2) in maize and deoxynivalenol, zearalenone and HT-2 + T-2 toxins in wheat, represent a health risk for the average adult consumer in Algeria. These results pointed out the necessity of a consistent control and the definition of maximum allowed levels for mycotoxins in Algerian foodstuffs.

Risk assessment of the exposure to mycotoxins in dogs and cats through the consumption of commercial dry food

Dry feed for dogs and cats sold in Europe are mostly formulated with cereals and cereal by-products, so the contamination of this food with mycotoxins represents a potential risk for these pets. We analyzed a representation of the best-selling feed brands in Spain. The presence of Aflatoxins (B1, B2, G1, and G2), Ochratoxin A, T-2 and HT-2 toxins, Deoxynivalenol, Zearalenone, and Fumonisins (B1 and B2) was quantified, using immunoaffinity columns and LC-MS/MS. In general, mycotoxins were frequently and simultaneously (6–11) detected, with AFB1, FB1, FB2, Deoxynivalenol, and HT-2 detected in 100% of the samples. However, the concentrations of most of them are among the lowest reported so far. Fumonisins were the exception since we report the highest concentrations to date, particularly in cat feed. We practically found no significant differences in the level of mycotoxin contamination in relation to the presumed quality of the feed. We also calculated the daily exposure, and evaluated the acute and chronic health risk posed by these feeds. None of the brands analyzed presented acute risk for any of the mycotoxins. However, the high levels of fumonisins found in some samples could become problematic, if there are hidden forms of them. This is also evident in relation to long-term risk, since in the case of fumonisins the level of exposure exceeds the tolerable daily intake level in 3.5 and 12 times, for dogs and cats respectively. The exposure levels to zearalenone and deoxynivalenol could also be of long-term concern, especially considering the possibility that the continuous exposure to several mycotoxins simultaneously might produce potentiated toxic effects as a result of their synergistic action. Further research on the potential adverse health effects deriving from chronic exposure to low doses of multi-mycotoxin mixtures in pets is needed.

Fumonisin B1, B2 and B3 in Muscle and Liver of Broiler Chickens and Turkey Poults Fed with Diets Containing Fusariotoxins at the EU Maximum Tolerable Level.

Although provisional maximum tolerable daily intake and recommended guidelines have been established for fumonisins (FB) in food, few data are available concerning levels of FB in edible animal tissues. Such data are of particular interest in avian species that can tolerate relatively high levels of fumonisins in their feed. Also, even if multiple contamination of animal feed by toxins produced by Fusarium is very frequent, little is known about the consequences of multiple contamination for FB levels in tissues. The aim of this study was to analyze the concentrations of FB in the muscle and liver of chickens and turkeys fed with FB alone and with FB combined with deoxynivalenol (DON), and with zearalenone (ZEN). Experimental diets were formulated by incorporating ground cultured toxigenic Fusarium strains in corn-soybean based feeds. Control diets were free of mycotoxins, FB diets contained 20 mg FB1+FB2/kg, and FBDONZEN diets contained 20, 5, and 0.5 mg/kg of FB1+FB2, DON, and ZEN, respectively. Animals were reared in individual cages with free access to water and feed. The feed was distributed to male Ross chickens from the 1st to the 35th day of age and to male Grade Maker turkeys from the 55th to the 70th day of age. On the last day of the study, the birds were starved for eight hours, killed, and autopsied for tissues sampling. No sign of toxicity was observed. A UHPLC-MS/MS method with isotopic dilution and immunoaffinity clean-up of samples has been developed for analysis of FB in muscle (n = 8 per diet) and liver (n = 8 per diet). Only traces of FB that were below the LOQ of 0.25 µg/kg were found in most of the samples of animals fed with the control diets. Mean concentrations of FB1, FB2, and FB3 in muscle were 17.5, 3.39, and 1.26 µg/kg, respectively, in chickens, and 5.77, 1.52, and 0.54 µg/kg in turkeys, respectively. In the liver, the respective FB1, FB2, and FB3 concentrations were 44.7, 2.61, and 0.79 µg/kg in chickens, and 41.47, 4.23, and 1.41 µg/kg, in turkeys. Cumulated level of FB1+FB2+FB3 in the highly contaminated samples were above 60 and 100 µg/kg in muscle and liver, respectively. The concentrations of FB in the tissues of animals fed the FBDONZEN diet did not greatly differ from the concentrations measured in animals fed the diet containing only FB.

Mycotoxin co-exposures in infants and young children consuming household- and industrially-processed complementary foods in Nigeria and risk management advice

This study compared mycotoxin levels in 53 household-formulated and 84 industrially-processed complementary foods, assessed co-exposure patterns from consumption of the contaminated foods by infants and young children (IYC) in two Nigerian states, and evaluated the influence of awareness and adopted processing practices at the household levels on toxin levels in the foods. About 42 and 93% of the industrial- and household-processed foods, respectively, were contaminated by mycotoxins. Aflatoxins, alternariol, citrinin and dihydrocitrinone levels were significantly higher in household-formulated foods while fumonisins were similarly higher in the industrially-processed foods. Of the household-formulated items, Tom bran contained higher aflatoxin levels leading to higher exposure (median: 641 ng/kg bw per day) and health risk (β-coefficient: 51.4; p = 0.01) in the IYC. Family cereal and ogi contained the highest levels of fumonisins in the industrial and household food categories, respectively, with the highest exposure estimated for IYC who consumed family cereal (median: 18 μg/kg bw per day). Aflatoxin exposures were higher in children aged 12–24 months compared to those below 12 months of age. About 69 and 75% of IYC who consumed family cereal and Tom bran, respectively, were co-exposed to mycotoxins resulting in commensurate risks of co-exposures. Overall, 47% of the IYC were co-exposed to 2–4 mycotoxins (aflatoxins, citrinin, fumonisins and ochratoxin A) with eight different co-exposure combinations. Only 33% of the respondents were aware of mycotoxins. Length of grain storage influenced food aflatoxin levels. Adequate risk management advice to concerned stakeholders for mycotoxin control in complementary foods in Nigeria is offered herein.

Outbreak of an acute aflatoxicosis in Tanzania during 2016

In June 2016, an outbreak of an unknown disease was reported to affect clusters of families in two regions of the central part of Tanzania. A rapid epidemiological survey was conducted in the affected villages, with a detailed house-to-house survey in selected households. A total of 68 cases occurred between 14 May and 14 November 2016, of which 20 died, making a case fatality rate of 30%. Over 50% of the cases were below the age of 15 years. The cases presented with jaundice (n=60), abdominal pain (n=59), vomiting (n=56), diarrhoea (n=34) and ascites (n=32). The responsible food item appeared to be home grown maize. The rate ratio indicated that the occurrence of illnesses was associated with ingestion of food contaminated with high levels of aflatoxins (contamination range: 10-51,100 μg/kg and 2.4-285 μg/kg for case and control households, respectively). Serum aflatoxin biomarker indicated that cases were more likely to have higher than 1000 pg/mg aflatoxin-albumin adduct level in their sera compared to controls (Odds Ratio = 13.5; 95% confidence intervals = 1.5-165.3; range of aflatoxin-albumin adduct level = 36- 32,800 pg/mg for cases and 10-4020 pg/mg for controls). Beside aflatoxins, maize samples were also contaminated with high levels of fumonisins (range of contamination; 945-12,630 μg/kg) with 8 of 10 samples analysed from case households co-contaminated with both toxins at levels above the maximum limit of 5 or 10 μg/kg set for AFB1 or total aflatoxins and 2,000 μg/kg for fumonisins. Clinical presentation and high levels of aflatoxin in food samples coupled with high levels of serum aflatoxin-albumin adducts among the cases support the causal role of aflatoxins.

Multimycotoxins occurrence in spices and herbs commercialized in Lebanon

Aflatoxins and ochratoxin A are regulated in Europe for some spices (Capsicum spp., Piper spp., Myristica fragrans, Zingiber officinale, Curcuma longa) and mixtures of spices containing one or more of these spices. No mycotoxin limits are in force for herbs. A total of 132 samples of spices (94) and herbs (38) purchased from Beirut in Lebanon were analysed for 12 mycotoxins (AFB1, AFB2, AFG1, AFG2, OTA, FB1, FB2, HT-2, T-2, ZEA, DON, NIV) by using a UPLC-MS/MS method based on ‘dilute and shoot’ approach. The limits of detection (LOD) ranged from 0.1 μg/kg (ZEA) to 20.5 μg/kg (DON) and limits of quantification (LOQ) ranged from 0.3 μg/kg (ZEA) to 68.2 μg/kg (DON). 80% of analysed samples were contaminated by 1–11 mycotoxins. Total aflatoxins and ochratoxin A were detected in 19 and 30% of spices, 8 and 11% of herbs, respectively. Mean levels of total aflatoxins and ochratoxin A were 168.1 and 7.1 μg/kg in positive spices, 36.1 and 7.0 μg/kg in positive herbs, respectively. 78 and 10% of positive spice samples contained aflatoxin and ochratoxin A at levels higher than the limits, respectively. Total aflatoxin levels higher than the European limits were also measured in some non-regulated spices (allspice, cloves, coriander, fenugreek) and some herbs (rosemary, sage and oregano). Within the non-regulated mycotoxins FB1 was the most occurring (60% in spices, 55% in herbs) followed by FB2 (35% in spices, 18% in herbs), ZEA (30% in spices, 3% in herbs), DON (12% in spices, 3% in herbs), T-2 and HT-2 toxins (3–5%), whereas NIV and AFG2 were never detected. Mean levels of FB1, FB2, ZEA and DON in positive samples of spices were 6432.3, 203.2, 30.6, 1751.4 μg/kg, respectively; in positive samples of herbs they were 2826.3, 214.9, 2.8, 589.7 μg/kg, respectively. The whole results demonstrate the higher susceptibility of spices to mycotoxin contamination with respect to herbs. Comparison of results obtained for samples produced with (81) and without (51) HACCP and GMP showed that the implementation of HACCP and GMP practices seems to be effective in reducing the occurrence of regulated mycotoxins but was ineffective for the non-regulated ones. The samples analysed in this study originated from at least 15 Countries and the results obtained gives indications about the occurrence of mycotoxins in relation to the Country of origin of the samples.The high percentages of positive samples and the high levels of some mycotoxins observed in this study highlight the problem of mycotoxin contamination in spices and herbs consumed in Lebanon. The occurrence of high levels of aflatoxins and OTA in some non-regulated spices and herbs suggests the addition of these matrices in the list of regulated ones. The high number of positive samples and the high levels of fumonisins observed in this study suggest the inclusions of these mycotoxins in the list of regulated mycotoxins for these matrices.

Pathogenicity and toxigenicity of Fusarium verticillioides isolates collected from maize roots, stems and ears in South Africa

Fusarium verticillioides is most frequently associated with maize in South Africa. It colonises maize roots, stems and ears endophytically and causes diseases such as Fusarium ear rot (FER) and stalk rot. Fusarium verticillioides can produce fumonisins, which are toxic secondary metabolites harmful to humans and animals. It is, however, unknown whether endophytic and pathogenic isolates from distinct maize tissues differ in their ability to cause disease and produce fumonisins. In this study, Fusarium spp. were collected from maize roots, stems and kernels for phylogenetic analysis and the F. verticillioides isolates were subjected to pathogenic and toxigenic comparison. The translation elongation 1-α (TEF1) gene of the isolates was sequenced, and a phylogenetic tree constructed with maximum likelihood (ML) and Bayesian interference (BI) inferred. Fumonisin production of F. verticillioides isolates was determined in vitro and in planta by using high performance liquid chromatography, and virulence of the isolates was determined by silk channel inoculation of maize ears under field conditions. F. verticillioides was the species with the highest number of isolates followed by F. temperatum and then F. subglutinans. Phylogenetic analyses clustered the different Fusarium spp. according to species. Fumonisin production by F. verticillioides isolates varied from 0 to 21.3 mg/kg in vitro, and 0–16.2 mg/kg in planta. All the F. verticillioides isolates produced FER symptoms, including isolates from roots and stems. Fusarium verticillioides isolates in South Africa thus presented a species highly diverse in toxigenicity, but not in virulence. This finding has implications for managing mycotoxins in maize, as visible symptoms might be misleading to the actual toxin level present, for example low level of disease severity might represent high fumonisin levels and vice versa. The high numbers of F. temperatum, also a mycotoxin producer highlights the concern that kernels could be contaminated with more than one mycotoxin. Integrated disease management of not only F. verticillioides but all Fusarium spp. should thus focus strongly on reducing fungal contamination of maize and the detoxification of grain with focus on using regionally adapted maize varieties.

Symptomatological aspects associated with fungal incidence and fumonisin levels in corn kernels

Toxigenic fungi that infect corn grains are among the major problems in Brazil as they are associated with toxicological implications for both humans and animals. Mechanical-physical methods have been used to separate contaminated grains in lots of corn kernels based on the symptoms caused by fungi. The objective of this study was to assess whether the presence or the type of symptoms were associated with fungal incidence and total fumonisin levels in corn kernel samples from the field. Kernels of two hybrids were separated visually into three groups: 1) asymptomatic or symptomatic exhibiting 2) kernel rot or 3) kernel streak symptoms. A high frequency of Fusarium spp. was observed in asymptomatic (69.5%) and kernel rot (69.9%). Stenocarpella sp. and Penicillium sp. were found in kernel rot (16.0%) and kernel streak (44.1%), respectively. High fumonisin levels (7.24 μg.g-1), above the maximum tolerated limit, were detected only in kernel rot. No association between fumonisin levels and the frequency of Fusarium spp. in kernels was found.

Assessment of awareness of mycotoxins infections in stored maize (Zea mays L.) and groundnut (arachis hypogea L.) in Kilosa District, Tanzania

Surveys were conducted to determine awareness of mould infection in maize and groundnut in Kilosa District, Eastern Central Tanzania, between August and October 2010. Four villages of Msingisi, Rudewa-Batini, Mamoyo and Mkalama were surveyed. We sampled maize from each household for mycotoxins contamination after nine months of storage. A questionnaire was administered to heads of 72 selected households in the study area. Principal component analysis (PCA) was used to check factor dimensionality. The differences in mean total score of knowledge and awareness between the demographic and socio-economic factors were determined by t-test. Measurements of association were carried by Chi-square test (χ2), while ordinal logistic regression analysis was used to examine the correlations between social variables and awareness of mould infection. We found high levels of fumonisins in maize that ranged from 70.46 to 213.15. Aflatoxin levels in groundnuts ranged from 72.97 to 195.17. Result showed that 97 % of respondents were not aware of mould infection in stored maize and groundnuts. The mean score of mould infections awareness of females (1.7273 ± 0.45055) was significantly higher than that of males (1.5714 ± 13.7). Awareness of mould infection was high among educated (mean score 1.9231.3 ± 0.31470) than the less educated people (mean score 1.8913 ± 0.27175). Results revealed significant association between awareness of mould infection with age (p = 0.006), education (p = 0.039), marital status (p = 0.012), gender (0.037) and income (p = 0.044). Campaigns are needed to improve awareness of mould infection in Kilosa District, Tanzania.

Influence of harvest time on fumonisin contamination of forage maize for whole-crop silage

Forage maize growing in agricultural fields is often contaminated with fumonisins, a group of mycotoxins produced by Fusarium species. We investigated fumonisin accumulation in maize plants from 2 to 10 wk after silking. Our aim was to determine whether harvesting forage maize earlier could be a practical control measure to reduce the fumonisin contamination in whole-crop silage. In a year with high fumonisin levels, the total fumonisin content (consisting of fumonisins B1, B2, and B3) of the maize plants increased 4–8 wk after silking, indicating that the risk of contamination increases with later harvest times.