Spatiotemporal assessment of post-harvest mycotoxin contamination in rural North Indian food systems.

The spatiotemporal trends in aflatoxin B1 (AFB1), fumonisin B1 (FB1), and deoxynivalenol (DON) accumulation were analyzed in a range of food commodities (maize, groundnut, pearl millet, rice, and wheat) in village settings in Unnao, Uttar Pradesh, India. Samples (n = 1549) were collected across six communities and six time points spanning a calendar year and were analyzed for mycotoxins using enzyme-linked immunosorbent assays. AFB1 and FB1 were common across surveyed villages, with moderate to high detection rates (45-75%) observed across commodities. AFB1 levels in maize and groundnuts and FB1 levels in maize and pearl millet frequently exceeded regulatory threshold levels of 15 µg/kg (AFB1) and 2 µg/g (FB1). DON was analyzed in wheat, with 3% of samples yielding detectable levels and none exceeding 1 µg/g. In rice, AFB1 levels were highest in the bran and husk and lower in the kernel. Commodity type significantly influenced AFB1 detection status, while commodity type, season, and visual quality influenced samples' legal status. Storage characteristics and household socioeconomic status indicators did not have significant effects on contamination. No significant effects of any variables on FB1 detection or legal status were observed. Data on mycotoxin contamination, combined with data on local dietary intake, were used to estimate spatiotemporal mycotoxin exposure profiles. Estimated seasonal per capita exposure levels for AFB1 (5.4-39.3 ng/kg body weight/day) and FB1 (~0-2.4 µg/kg body weight/day) exceeded provisional maximum tolerable daily intake levels (1 ng/kg body weight/day for AFB1 and 2 µg/kg body weight/day for FB1) in some seasons and locations. This study demonstrates substantial dietary mycotoxin exposure risk in Unnao food systems and serves as an evidentiary foundation for participatory food safety intervention in the region.

Risk of dietary and breastmilk exposure to mycotoxins among lactating women and infants 2-4 months in northern India.

Mycotoxins are carcinogenic secondary metabolites of fungi that have been linked to infant growth faltering. In this study, we quantified co-occurring mycotoxins in breast milk and food samples from Haryana, India, and characterized determinants of exposure. Deterministic risk assessment was conducted for mothers and infants. We examined levels of eight mycotoxins (Aflatoxin B1 , B2 , G1 , G2 , M1 , M2 ; Ochratoxin A, B) in 100 breast milk samples (infants 2-4 months) using ultra-high-performance liquid chromatography tandem mass spectrometry. Aflatoxin B1 (AFB1 ), fumonisin B1 (FB1 ) and deoxynivalenol (DON) were detected in several food items (n = 298) using enzyme-linked immunosorbent assays. We report novel data on the presence of mycotoxins in breast milk samples from India. Whereas breast milk concentrations (AFM1 median: 13.7; range: 3.9-1200 ng/L) remain low, AFM1 was detected above regulatory limits in 27% of animal milk samples. Additionally, 41% of infants were above provisional maximum tolerable daily intake (PMTDI) limits for AFM1 due to consumption of breast milk (mean: 3.04, range: 0.26-80.7 ng kg-1 bw day-1 ). Maternal consumption of breads (p < 0.05) was associated with breast milk AFM1 exposure. AFB1 (µg/kg) was detected in dried red chilies (15.7; 0-302.3), flour (3.13; 0-214.9), groundnuts (0; 0-249.1), maize (56.0; 0-836.7), pearl millet (1.85; 0-160.2), rice (0; 0-195.6), wheat (1.9; 0-196.0) and sorghum (0; 0-63.5). FB1 (mg/kg) was detected in maize (0; 0-61.4), pearl millet (0; 0-35.4) and sorghum (0.95; 0-33.2). DON was not detected in food samples. Mothers in our study exceeded PMTDI recommendations for AFB1 due to consumption of rice and flour (mean: 75.81; range: 35.2-318.2 ng kg-1 bw day-1 ). Our findings show the presence of Aflatoxin B1 and M1 at various levels of the food chain and in breast milk, with estimated intakes exceeding PMTDI recommendations. Aflatoxins are known carcinogens and have also been linked to stunting in children. Their presence across the food system and in breast milk is concerning, thus warranting further research to replicate and expand on our findings and to understand implications for maternal and child health.

Dissecting Symptomatology and Fumonisin Contamination Produced by Fusarium verticillioides in Maize Ears.

The fungus Fusarium verticillioides can infect maize ears, contaminating the grain with mycotoxins, including fumonisins. This global public health threat can be managed by breeding maize varieties that are resistant to colonization by F. verticillioides and by sorting grain after harvest to reduce fumonisin levels in food systems. Here, we employed two F. verticillioides inoculation techniques representing distinct infection pathways to dissect ear symptomatology and morphological resistance mechanisms in a diverse panel of maize inbred lines. The "point" method involved penetrating the ear with a spore-coated toothpick and the "inundative" method introduced a liquid spore suspension under the husk of the ear. We evaluated quantitative and qualitative indicators of external and internal symptom severity as low-cost proxies for fumonisin contamination, and found that kernel bulk density was predictive of fumonisin levels (78 to 84% sensitivity; 97 to 99% specificity). Inundative inoculation resulted in greater disease severity and fumonisin contamination than point inoculation. We also found that the two inoculation methods implicated different ear tissues in defense, with cob morphology being a more important component of resistance under point inoculation. Across both inoculation methods, traits related to cob size were positively associated with disease severity and fumonisin content. Our work demonstrates that (i) the use of diverse modes of inoculation is necessary for combining complementary mechanisms of genetic resistance, (ii) kernel bulk density can be used effectively as a proxy for fumonisin levels, and (iii) trade-offs may exist between yield potential and resistance to fumonisin contamination.

Mycotoxins and bone growth: a review of the literature on associations between xenobiotic exposure and bone growth and development.

Mycotoxins are secondary metabolites of fungi that are known to be associated with linear growth faltering because of their impact on inflammation, intestinal damage, inhibition of protein synthesis, and micronutrient absorption. In this narrative review, we aim to extend this analysis to further explore associations between mycotoxins (aflatoxins, ochratoxins, trichothecenes including deoxynivalenol, T-2 toxin, and fumonisins) and long-bone growth, particularly during the saltatory periods of development. Linear growth is a direct function of skeletal development and long-bone growth. We therefore explored biological pathways and mechanisms of impact of these toxins in both animal and human studies, in addition to the epidemiology literature (post-2020). Given what is known of the effects of individual and combinations of mycotoxins based on the animal literature, we have identified a need for further research and examination of how these toxins and exposures may be studied in humans to elucidate the downstream impact on bone-related biomarkers and anthropometric indices used to identify and predict stunting in population-based studies.

Why Plants Harbor Complex Endophytic Fungal Communities: Insights From Perennial Bunchgrass Stipagrostis sabulicola in the Namib Sand Sea.

All perennial plants harbor diverse endophytic fungal communities, but why they tolerate these complex asymptomatic symbioses is unknown. Using a multi-pronged approach, we conclusively found that a dryland grass supports endophyte communities comprised predominantly of latent saprophytes that can enhance localized nutrient recycling after senescence. A perennial bunchgrass, Stipagrostis sabulicola, which persists along a gradient of extreme abiotic stress in the hyper-arid Namib Sand Sea, was the focal point of our study. Living tillers yielded 20 fungal endophyte taxa, 80% of which decomposed host litter during a 28-day laboratory decomposition assay. During a 6-month field experiment, tillers with endophytes decomposed twice as fast as sterilized tillers, consistent with the laboratory assay. Furthermore, profiling the community active during decomposition using next-generation sequencing revealed that 59-70% of the S. sabulicola endophyte community is comprised of latent saprophytes, and these dual-niche fungi still constitute a large proportion (58-62%) of the litter community more than a year after senescence. This study provides multiple lines of evidence that the fungal communities that initiate decomposition of standing litter develop in living plants, thus providing a plausible explanation for why plants harbor complex endophyte communities. Using frequent overnight non-rainfall moisture events (fog, dew, high humidity), these latent saprophytes can initiate decomposition of standing litter immediately after tiller senescence, thus maximizing the likelihood that plant-bound nutrients are recycled in situ and contribute to the nutrient island effect that is prevalent in drylands.