Mycotoxin exposure biomonitoring in breastfed and non-exclusively breastfed Nigerian children

A multi-specimen, multi-mycotoxin approach involving ultra-sensitive LC-MS/MS analysis of breast milk, complementary food and urine was applied to examine mycotoxin co-exposure in 65 infants, aged 1-18 months, in Ogun state, Nigeria. Aflatoxin M₁ was detected in breast milk (4/22 (18%)), while six other classes of mycotoxins were quantified; including dihydrocitrinone (6/22 (27%); range: 14.0-59.7 ng/L) and sterigmatocystin (1/22 (5%); 1.2 ng/L) detected for the first time. Seven distinct classes of mycotoxins including aflatoxins (9/42 (21%); range: 1.0-16.2 µg/kg) and fumonisins (12/42 (29%); range: 7.9-194 µg/kg) contaminated complementary food. Mycotoxins covering seven distinct classes with diverse structures and modes of action were detected in 64/65 (99%) of the urine samples, demonstrating ubiquitous exposure. Two aflatoxin metabolites (AFM₁ and AFQ₁) and FB₁ were detected in 6/65 (9%), 44/65 (68%) and 17/65 (26%) of urine samples, respectively. Mixtures of mycotoxin classes were common, including 22/22 (100%), 14/42 (33%) and 56/65 (86%) samples having 2-6, 2-4, or 2-6 mycotoxins present, for breast milk, complementary food and urine, respectively. Aflatoxin and/or fumonisin was detected in 4/22 (18%), 12/42 (29%) and 46/65 (71%) for breast milk, complimentary foods and urine, respectively. Furthermore, the detection frequency, median concentrations and occurrence of mixtures were typically greater in urine of non-exclusively breastfed compared to exclusively breastfed infants. The study provides novel insights into mycotoxin co-exposures in early-life. Albeit a small sample set, it highlights transition to higher levels of infant mycotoxin exposure as complementary foods are introduced, providing impetus to mitigate during this critical early-life period and encourage breastfeeding.

Biomonitoring of Multiple Mycotoxins in Urine by GC-MS/MS: A Pilot Study on Patients with Esophageal Cancer in Golestan Province, Northeastern Iran

A pilot study to investigate the occurrence of 10 mycotoxins (deoxynivalenol, DON; 3-acetyldeoxynivalenol, 3-ADON; 15-acetyldeoxynivalenol, 15-ADON; fusarenon-X, FUS-X; diacetoxyscirpenol, DAS; nivalenol, NIV; neosolaniol, NEO; zearalenone, ZON; zearalanone, ZAN; T-2 toxin, T-2; and HT-2 toxin, HT-2) in esophageal cancer patients was performed with the urinary biomarkers approach in Golestan, Iran. Urine multimycotoxin analysis was performed by dispersive liquid–liquid microextraction and gas chromatography–tandem mass spectrometry (GC–MS/MS) analysis, and values were normalized with urinary creatinine (μg/g). Four mycotoxins, namely NEO (40%), HT-2 (17.6%), DON (10%), and HT-2 (5.8%), were detected in the analyzed urine samples. DON was only detected in the control group (5.09 μg/g creatinine), while T-2 (44.70 μg/g creatinine) was only present in the esophageal cancer group. NEO and HT-2 were quantified in both control and case groups, showing average of positive samples of 9.09 and 10.45 μg/g creatinine for NEO and 16.81 and 29.09 μg/g creatinine for HT-2, respectively. Mycotoxin co-occurrence was observed in three samples as binary (NEO/HT-2 and T-2/HT-2) and ternary (DON/NEO/HT-2) combinations, reaching total concentrations of 44.58, 79.13, and 30.04 µg/g creatinine, respectively. Further investigations are needed to explore a causal association between mycotoxin contamination and esophageal cancer. For this pilot study in Golestan, the low sample size was a very limiting factor.

Risks to human and animal health related to the presence of deoxynivalenol and its acetylated and modified forms in food and feed

Deoxynivalenol (DON) is a mycotoxin primarily produced by Fusarium fungi, occurring predominantly in cereal grains. Following the request of the European Commission, the CONTAM Panel assessed the risk to animal and human health related to DON, 3-acetyl-DON (3-Ac-DON), 15-acetyl-DON (15-Ac-DON) and DON-3-glucoside in food and feed. A total of 27,537, 13,892, 7,270 and 2,266 analytical data for DON, 3-Ac-DON, 15-Ac-DON and DON-3-glucoside, respectively, in food, feed and unprocessed grains collected from 2007 to 2014 were used. For human exposure, grains and grain-based products were main sources, whereas in farm and companion animals, cereal grains, cereal by-products and forage maize contributed most. DON is rapidly absorbed, distributed, and excreted. Since 3-Ac-DON and 15-Ac-DON are largely deacetylated and DON-3-glucoside cleaved in the intestines the same toxic effects as DON can be expected. The TDI of 1 μg/kg bw per day, that was established for DON based on reduced body weight gain in mice, was therefore used as a group-TDI for the sum of DON, 3-Ac-DON, 15-Ac-DON and DON-3-glucoside. In order to assess acute human health risk, epidemiological data from mycotoxicoses were assessed and a group-ARfD of 8 μg/kg bw per eating occasion was calculated. Estimates of acute dietary exposures were below this dose and did not raise a health concern in humans. The estimated mean chronic dietary exposure was above the group-TDI in infants, toddlers and other children, and at high exposure also in adolescents and adults, indicating a potential health concern. Based on estimated mean dietary concentrations in ruminants, poultry, rabbits, dogs and cats, most farmed fish species and horses, adverse effects are not expected. At the high dietary concentrations, there is a potential risk for chronic adverse effects in pigs and fish and for acute adverse effects in cats and farmed mink.

Multidetection of urinary ochratoxin A, deoxynivalenol and its metabolites: pilot time-course study and risk assessment in Catalonia, Spain

The presence of two main mycotoxins, ochratoxin A (OTA) and deoxynivalenol (DON), is widespread in cereal-based foodstuffs marketed in Europe. The objectives of this study were to develop and validate a multi-detection analytical methodology to simultaneously assess the urinary concentrations of OTA, DON and their metabolites, and to apply this methodology in a preliminary follow-up trial in Catalonia (Spain). Hence, an ultra-performance liquid chromatography with tandem mass spectrometry method was developed to simultaneously assess the urinary levels of OTA, DON, deoxynivalenol-3-glucoside (DON-3-glucoside), deoxynivalenol-3-glucuronide (DON-3-glucuronide), 3-acetyldeoxynivalenol (3-ADON) and de-epoxy-deoxynivalenol (DOM-1). Urine mycotoxins levels and food dietary intake were prospectively monitored in a group of volunteers throughout a restriction period followed by a free-diet period. The proposed multi-detection methodology for urinary OTA and DON metabolites was validated, providing suitable recovery, linearity and precision. The results from the pilot trial showed that urinary OTA, DON and its metabolites were detected in most background samples, displaying moderate reductions after the restriction period and subsequently recovering the background levels. Despite the restriction period, some DON metabolites, such as 3-ADON or DOM-1, were still found in urine samples, placing alternative sources of DON exposure other than the ones considered in the study under suspicion. DON and DON-3-glucuronide were significantly associated with consumption of bread, pasta and pastries, while OTA was only associated with consumption of wine and breakfast cereals. The urinary levels of OTA were significantly correlated with plasmatic levels of OTA and ochratoxin α, supporting the results from the multidetection method in urine. The results also showed that the high exposure to DON could be held throughout the time by the same person, exceeding the tolerable daily intake systematically instead of eventually. The estimates of OTA exposure through urine are largely higher than those obtained with the dietary approach. The background levels found in urine revealed that the exposure to DON and OTA could be of concern for the Catalonian population, thus, further studies applying this biomonitoring methodology in a larger sample of Catalonian population are needed to accurately characterise the human health risks at population level.

Esophageal Cancer in Golestan Province, Iran: A Review of Genetic Susceptibility and Environmental Risk Factors

Esophageal squamous cell carcinoma (ESCC) is an aggressive tumor that is typically diagnosed only when the tumor has gained remarkable size, extended to peripheral tissues, and led to dysphagia. Five-year survival of advanced cancer is still very poor (19%), even with improved surgical techniques and adjuvant chemoradiation therapy. Therefore, early detection and prevention are the most important strategies to reduce the burden of ESCC. Our review will focus on the studies conducted in Golestan province, an area with a high prevalence of ESCC in northern Iran. We review three aspects of the research literature on ESCC: epidemiological features, environmental factors (including substance abuse, environmental contaminants, dietary factors, and human papillomavirus [HPV]), and molecular factors (including oncogenes, tumor suppressor genes, cell cycle regulatory proteins, and other relevant biomarkers). Epidemiological and experimental data suggest that some chemicals and lifestyle factors, including polycyclic aromatic hydrocarbons (PAHs), cigarette smoking, opium use, and hot tea drinking are associated with the development of ESCC in Golestan. HPV infects the esophageal epithelium, but so far, no firm evidence of its involvement in esophageal carcinogenesis has been provided. Some of these factors, notably hot tea drinking, may render the esophageal mucosa more susceptible to injury by other carcinogens. There are few studies at molecular level on ESCC in Golestan. Increasing awareness about the known risk factors of ESCC could potentially reduce the burden of ESCC in the region. Further studies on risk factors, identifying high risk populations, and early detection are needed.

Deoxynivalenol and fumonisin exposure in children and adults in a family study in rural Tanzania

The relationship between child and parent exposure and excretion of deoxynivalenol (DON) and fumonisin B1 (FB1), were compared in rural Tanzania. Morning urine samples from matched child-mother-father in 50 families of the Iringa district were collected and analysed for urinary DON and FB1 using LC-MS methods. Maize intake was obtained using a seven-day food frequency questionnaire and a duplicate diet method. The urinary DON geometric means were 15.4, 45.0 and 42.0 ng/ml in children, mothers and fathers, respectively, and the urinary FB1 were 0.62, 1.25 and 1.38 ng/ml, respectively. Children had significantly lower levels of urinary DON and FB1 than their parents (P<0.001 and P=0.009, respectively) but the difference became non-significant when corrected for creatinine concentration. Both DON and FB1 were detected in urine samples from all adults and >96% of the children, respectively and were positively correlated between the child and the mother (P=0.007 and 0.02, respectively). DON or FB1 biomarkers were not correlated with maize intake. Children who were fully weaned had 3-fold higher urinary DON than those on partial breastfeeding (P=0.002). In adults, maize brew (a local produced beer) showed a strong positive correlation with both urinary DON and FB1 levels (P<0.001). The ratio of daily urinary excretion of DON between children and adult, based on assumed urine volume, was 1:2.26, but the excretion of FB1 was similar between children and adults. The study showed that DON and FB1 exposure are prevalent in rural Tanzania. Further study is required to determine the mechanism for the lower excretion of DON in children compared to adults. There is a good correlation between child and mother’s exposure levels to DON and FB1. Increased exposure risk through maize brew in adults is highlighted in this study.

Deoxynivalenol exposure assessment in young children in Tanzania

SCOPE

This study assessed deoxynivalenol (DON) exposure in children from three geographic locations within Tanzania, over three time points in 1 year, using a urinary biomarker of exposure.

METHODS AND RESULTS

A total of 166 children aged 6-14 months were studied at a maize harvest and followed up twice at 6-month intervals. On two consecutive days, morning urine was collected from each child and urinary DON was measured using an LC-MS method, with and without β-glucuronidase hydrolysis in order to assess free DON (fDON) and glucuronide DON. Overall, urinary DON increased significantly along with the three visits (geometric mean 1.1, 2.3, and 5.7 ng/mL, at visits 1, 2, and 3, respectively, p < 0.01). fDON was 22% of urinary total DON. Urinary DON excretion rate was 74% in village Kikelelwa based on food DON level and food consumption. Assuming 360 mL of urine excreted per day, 10, 19, and 29% of children at visits 1, 2, and 3, respectively, exceeded the provisional maximum tolerable daily intake of 1000 ng/kg b.w./day.

CONCLUSION

Young children in Tanzania are chronically exposed to DON due to eating contaminated maize, although exposure levels varied markedly by region and season.

Mycotoxin exposure in rural residents in northern Nigeria: a pilot study using multi-urinary biomarkers

A pilot, cross-sectional, correlational study was conducted in eight rural communities in northern Nigeria to investigate mycotoxin exposures in 120 volunteers (19 children, 20 adolescents and 81 adults) using a modern LC-MS/MS based multi-biomarker approach. First morning urine samples were analyzed and urinary biomarker levels correlated with mycotoxin levels in foods consumed the day before urine collection. A total of eight analytes were detected in 61/120 (50.8%) of studied urine samples, with ochratoxin A, aflatoxin M1 and fumonisin B1 being the most frequently occurring biomarkers of exposure. These mycotoxin biomarkers were present in samples from all age categories, suggestive of chronic (lifetime) exposures. Rough estimates of mycotoxin intake suggested some exposures were higher than the tolerable daily intake. Overall, rural consumer populations from Nasarawa were more exposed to several mixtures of mycotoxins in their diets relative to those from Kaduna as shown by food and urine biomarker data. This study has shown that mycotoxin co-exposure may be a major public health challenge in rural Nigeria; this calls for urgent intervention.

Assessment of multi-mycotoxin exposure in southern Italy by urinary multi-biomarker determination

Human exposure assessment to deoxynivalenol (DON), aflatoxin B1 (AFB1), fumonisin B1 (FB1), zearalenone (ZEA) and ochratoxin A (OTA) can be performed by measuring their urinary biomarkers. Suitable biomarkers of exposure for these mycotoxins are DON + de-epoxydeoxynivalenol (DOM-1), aflatoxin M1 (AFM1), FB₁, ZEA + α-zearalenol (α-ZOL) + β-zearalenol (β-ZOL) and OTA, respectively. An UPLC-MS/MS multi-biomarker method was used to detect and measure incidence and levels of these biomarkers in urine samples of 52 volunteers resident in Apulia region in Southern Italy. The presence of ZEA + ZOLs, OTA, DON, FB1 and AFM1 were detected in 100%, 100%, 96%, 56% and 6%, of samples, respectively. All samples contained biomarkers of two or more mycotoxins. The mean concentrations of biomarkers ranged from 0.055 ng/mL (FB1) to 11.89 ng/mL (DON). Urinary biomarker concentrations were used to estimate human exposure to multiple mycotoxin. For OTA and DON, 94% and 40% of volunteers, respectively exceeded the tolerable daily intake (TDI) for these mycotoxins. The estimated human exposure to FB1 and ZEA was largely below the TDI for these mycotoxins for all volunteers.

Biomonitoring study of deoxynivalenol exposure and association with typical cereal consumption in Swedish adults

Deoxynivalenol (DON) is a mycotoxin of the trichothecene family commonly found in cereals infested with different Fusarium species. DON acts primarily on the gastrointestinal and immune system and is suspected to be an underlying agent causing several outbreaks of gastrointestinal disorder among humans, which prompts studies of human exposure and estimations of intake among populations. However, assessing human exposure to mycotoxins is associated with several difficulties. Therefore, a study was undertaken among adults (18-80 years) in a subgroup of Riksmaten, the Swedish national survey investigating dietary habits, examining both the association between urinary DON concentration and dietary intake of cereals, and estimations of daily DON intake. The results indicate that exposure to DON is common among Swedish adults, as this mycotoxin was detected in 292 out of 326 urine samples (90%) at levels ranging from non-detectable to 65.8 ng DON/ml urine with a median level of 2.9 ng/ml. Furthermore, urinary DON (ng/mg creatinine) was associated with intake (g/day) of total cereal grain as well as whole grain. Urinary DON was also significantly associated with breakfast cereals and porridge consumption (P<0.05). Estimated DON intake in this study ranged between 2.5 and 5,443 ng/kg body weight (bw). 1% of the individuals had estimated intakes above the group provisional maximum tolerable daily intake (PMTDI; 1 μg/kg), whereas the mean and median intakes of 159 and 84 ng DON/kg bw, respectively, were considerably below the PMTDI. Along with the toxicological profile of DON, no serious health implications are to be expected for the majority of Swedish adults, although a potential health concern remains for some high cereal consumers. In conclusion, biomonitoring could prove to be a valuable tool for observing DON exposure among populations.

Mycotoxins: occurrence, toxicology, and exposure assessment

Mycotoxins are abiotic hazards produced by certain fungi that can grow on a variety of crops. Consequently, their prevalence in plant raw materials may be relatively high. The concentration of mycotoxins in finished products is usually lower than in raw materials. In this review, occurrence and toxicology of the main mycotoxins are summarised. Furthermore, methodological approaches for exposure assessment are described. Existing exposure assessments, both through contamination and consumption data and biomarkers of exposure, for the main mycotoxins are also discussed.

Urinary analysis reveals high deoxynivalenol exposure in pregnant women from Croatia

In this pilot survey the levels of various mycotoxin biomarkers were determined in third trimester pregnant women from eastern Croatia. First void urine samples were collected and analysed using a "dilute and shoot" LC-ESI-MS/MS multi biomarker method. Deoxynivalenol (DON) and its metabolites: deoxynivalenol-15-glucuronide and deoxynivalenol-3-glucuronide were detected in 97.5% of the studied samples, partly at exceptionally high levels, while ochratoxin A was found in 10% of the samples. DON exposure was primarily reflected by the presence of deoxynivalenol-15-glucuronide with a mean concentration of 120 μg L(-1), while free DON was detected with a mean concentration of 18.3 μg L(-1). Several highly contaminated urine samples contained a third DON conjugate, tentatively identified as deoxynivalenol-7-glucuronide by MS/MS scans. The levels of urinary DON and its metabolites measured in this study are the highest ever reported, and 48% of subjects were estimated to exceed the provisional maximum tolerable daily intake (1 μg kg(-1) b.w.).

Multiple mycotoxin exposure determined by urinary biomarkers in rural subsistence farmers in the former Transkei, South Africa

Subsistence farmers are exposed to a range of mycotoxins. This study applied novel urinary multi-mycotoxin LC-MS/MS methods to determine multiple exposure biomarkers in the high oesophageal cancer region, Transkei, South Africa. Fifty-three female participants donated part of their maize-based evening meal and first void morning urine, which was analysed both with sample clean-up (single and multi-biomarker) and by a 'dilute-and-shoot' multi-biomarker method. Results were corrected for recovery with LOD for not detected. A single biomarker method detected fumonisin B1 (FB1) (87% incidence; mean±standard deviation 0.342±0.466 ng/mg creatinine) and deoxynivalenol (100%; mean 20.4±49.4 ng/mg creatinine) after hydrolysis with β-glucuronidase. The multi-biomarker 'dilute-and-shoot' method indicated deoxynivalenol-15-glucuronide was predominantly present. A multi-biomarker method with β-glucuronidase and immunoaffinity clean-up determined zearalenone (100%; 0.529±1.60 ng/mg creatinine), FB1 (96%; 1.52±2.17 ng/mg creatinine), α-zearalenol (92%; 0.614±1.91 ng/mg creatinine), deoxynivalenol (87%; 11.3±27.1 ng/mg creatinine), β-zearalenol (75%; 0.702±2.95 ng/mg creatinine) and ochratoxin A (98%; 0.041±0.086 ng/mg creatinine). These demonstrate the value of multi-biomarker methods in measuring exposures in populations exposed to multiple mycotoxins. This is the first finding of urinary deoxynivalenol, zearalenone, their conjugates, ochratoxin A and zearalenols in Transkei.

Fumonisin biomarkers in maize eaters and implications for human disease

Maize is the predominant food source contaminated by fumonisins and this has particular health risks for communities consuming maize as a staple diet. The main biochemical effect of fumonisins is the inhibition of ceramide biosynthesis causing an increase in sphingoid bases and sphingoid base 1-phosphates and a depletion of the complex sphingolipids, thereby disrupting lipid metabolism and sphingolipid-mediated processes and signalling systems. Attempts to use the elevation of sphinganine as a human biomarker of fumonisin exposure have to date been unsuccessful. Consequently, recent research has focussed on developing a urinary exposure biomarker based on the measurement of the nonmetabolised toxin. In animals, fumonisins are poorly absorbed in the gut and are mostly excreted unmetabolised in faeces, with only a small percentage (0.25-2.0%) in urine. This appears to also be true in humans were fumonisin B1 (FB1) is detectable in urine soon after exposure, but in very small amounts relative to total intake. However, with modern sensitive and selective analytical methods such as liquid chromatography-tandem mass spectrometry, these low levels can be readily determined. The first study to show a positive correlation between consumption of maize and urinary FB1 was conducted in a Mexican population consuming tortillas as a staple food. Further validation of this relationship was achieved in a South African subsistence farming community with a positive correlation between urinary FB1 and fumonisin exposure, as assessed by food analysis and food intake data. The most recent developments are aimed at measuring multiple mycotoxin biomarkers in urine, including FB1. Current exposure studies in Guatemala are combining the urinary biomarker with measurement of sphinganine-1-phosphate in blood spots as a measure of biochemical effect. Thus, the urinary FB1 biomarker could contribute considerably in assessing the adverse health impact of fumonisin exposure.

Geographic differences in trichothecene chemotypes of Fusarium graminearum in the Northwest and North of Iran

The diversity and prevalence of Fusarium species and their chemotypes on wheat in the North-West and North of Iran was determined. Wheat in these areas is severely affected by Fusarium head blight, with Fusarium graminearum as prevalent species causing 96% of the infections in the North-West and 50% in the Northern provinces. Fungal isolates were identified based on morphological characters and sequences of the internal transcribed spacer region, and parts of translation elongation factor 1-? and RNA polymerase subunit II sequences. Phylogenetic and phylogeographic analyses show little haplotype variation between the F. graminearum strains collected from the different locations, but the isolates differ significantly in their trichothecene chemotypes as determined with a multilocus genotyping assay. F. graminearum strains producing 15-acetyldeoxynivalenol were abundant in Ardabil (North-West of Iran), while in Golestan province (North of Iran) at the other side of the Caspian Sea especially nivalenol producing strains and a variety of other Fusarium species were observed. Strains producing 3-acetyldeoxynivalenol were rarely found in both areas. This is the first detailed study on Fusarium infections in Iranian wheat, showing large differences in prevalent etiological agents and in mycotoxin chemotypes geographically.

Developments in mycotoxin analysis: an update for 2011-2012

This review highlights developments in mycotoxin analysis and sampling over a period between mid-2011 and mid- 2012. It covers the major mycotoxins aflatoxins, Alternaria toxins, ergot alkaloids, fumonisins, ochratoxin, patulin, trichothecenes, and zearalenone. A section on mycotoxins in botanicals and spices is also included. Methods for mycotoxin determination continue to be developed using a wide range of analytical systems ranging from rapid immunochemical-based methods to the latest advances in mass spectrometry. This review follows the format of previous reviews in this series (i.e. sections on individual mycotoxins), but due to the rapid spread and developments in the field of multimycotoxin methods by liquid chromatography-tandem mass spectrometry, a separate section has been devoted to advances in this area of research.