Toxins最新文献

Cyanobacteria harmful algal blooms (CHABs) are most commonly caused by the proliferation of the toxic species, Microcystis aeruginosa. It is therefore of considerable interest to develop biological control processes which are economically feasible and scalable for this cyanobacteria that produces the cyanotoxin, microcystin. Some gastropods that are abundant in freshwater ecosystems can filter feed on floating planktonic microphytes. We investigated this in the freshwater snail, Sinotaia aeruginosa which indiscriminately accumulated M. aeruginosa, Chlorella vulgaris, and Trichormus variabilis (syn. Anabaena variabilis) The initial filtration rates were approx. 44 and 19 mL · g_wwt^-1 · h^-1 for unicellular and colony-forming M. aeruginosa, respectively. The pseudofaeces that were formed directly by filtration possessed a limited period of stability, and the bulk of the M. aeruginosa from pseudofaeces was eventually released back to the water column as undigested cyanobacteria. Nevertheless, the rate of sequestration of colonial M. aeruginosa into pseudofaeces was greater than its rate of release, thereby indicating that the temporary stability of pseudofaeces alone would be adequate to impede bloom formation. Therefore, these results provide evidence for using this gastropod in an effective preventative strategy for CHABs formation. Our results highlight the importance of understanding the impact of feeding mechanisms on ecosystem structure when proposing their use in biomanipulative processes aimed at correcting cyanobacteria impacted ecosystems.

Mycotoxins are toxic secondary metabolites produced by filamentous fungi that contaminate agricultural commodities, posing risks to food safety, animal productivity, and human health. The gastrointestinal tract is the first and most critical site of exposure, where the intestinal epithelium functions as both a physical and immunological barrier against luminal toxins and pathogens. While extensive research has demonstrated that mycotoxins disrupt epithelial integrity through tight junction impairment, oxidative stress, apoptosis, and inflammation, their effects on the intestinal stem cell (ISC) compartment and epithelial regeneration remain insufficiently understood. This review integrates recent findings from in vivo, cell culture, and advanced 3D intestinal organoid and gut-on-chip models to elucidate how mycotoxins such as deoxynivalenol and zearalenone impair ISC proliferation, alter Wnt/Notch signaling, and compromise mucosal repair. We also discuss dose relevance, species differences, and the modulatory roles of the microbiome and short-chain fatty acids, as well as emerging evidence of additive or synergistic toxicity under co-exposure conditions. By bridging well-established mechanisms of barrier disruption with the emerging concept of ISC-driven regenerative failure, this review identifies a critical knowledge gap in mycotoxin toxicology and highlights the need for integrative models that link epithelial damage to impaired regeneration. Collectively, these insights advance understanding of mycotoxin-induced intestinal dysfunction and provide a foundation for developing nutritional, microbial, and pharmacological strategies to preserve gut integrity and repair.

Fumonisins are among the most prevalent mycotoxins in maize and maize-based products, posing significant food safety and public health risks due to their hepatotoxic, nephrotoxic, and potential carcinogenic effects. Given the strict regulatory limits set by the European Commission and Codex Alimentarius, the development of reliable, sensitive, and matrix-robust analytical methods remain a priority for routine monitoring in both food and feed systems. In this study, a reusable immuno-affinity purification methodology for the quantitative determination of fumonisin mycotoxins (FB1, FB2 and FB3) in foods and feeds (maize matrix) was developed. A single extraction protocol using 2% formic acid in water was employed, followed by cleanup with an immuno-affinity purification column and toxin elution by methanol/PBS (1:1, v/v). Detection and quantification of the mycotoxins was achieved by a normal phase ultra-high performance liquid chromatography coupled with electrospray ionisation triple quadrupole mass spectrometry (UHPLC/ESI-MS/MS). The chromatographic mobile phase utilised was a linear gradient of methanol/water containing 0.1% formic acid. The developed method has a limit of detection of 2.5 ng/g and a limit of quantification of 5 ng/g, all well below the European commission's guidance values of 1000 ng/g for corn destined for human consumption and 800 ng/g for maize-based breakfast cereals and snacks. While the recovery rates of the method in this study ranged from 65-70% for the three fumonisin analogues in solutions, when tested in maize matrix, recoveries were markedly lower (~30%) due to pronounced matrix suppression. Good repeatability (standard deviation <10%) was achieved for all the fumonisin analogues. The developed method, although quick and effective in solvent systems, suffered limitations to its practical usage due to matrix suppression of the extracts derived from the immuno-affinity purification column, thus significantly reducing the application of the method in measuring fumonisin mycotoxins in food and feed samples. Overall, the method was effective in quantification of fumonisin mycotoxins in solvent solutions but not in food and feed matrices, thus necessitating further optimisation for practical usage. The performance of the developed method was compared to a commercial lateral flow immunochromatographic assay which proved to be better than the developed method in the quantification of toxins in food matrices, as the commercial lateral flow immunochromatographic assay outperformed the developed method in maize matrices. These findings highlight the need for matrix-based validation and further refinement of antibody stability to ensure robust application in regulatory monitoring of fumonisins using immunoaffinity purification methods.

Ochratoxin A (OTA) is a major mycotoxin contaminant in grapes and their products, and Aspergillus carbonarius is its main producer. Controlling the growth of A. carbonarius is therefore critical for mitigating OTA contamination. Plant-derived perillaldehyde, with good antifungal activity and safety, has garnered growing attention. However, current understanding of how perillaldehyde affects A. carbonarius growth and OTA production remains poorly characterized. In this study, we systematically investigated the antifungal and antimycotoxigenic effects of perillaldehyde against A. carbonarius and explored the underlying mechanisms. The results showed that perillaldehyde could alter the mycelial morphology and damage the cell integrity of A. carbonarius. Additionally, perillaldehyde could diminish the total antioxidant capacity and impair the energy metabolism of A. carbonarius. Transcriptome analysis showed that the expressions of all the known conserved OTA biosynthetic genes and two OTA transport-related genes were significantly down-regulated, indicating that perillaldehyde could directly inhibit their expression. In conclusion, perillaldehyde can significantly inhibit OTA production by directly disrupting OTA biosynthesis and transport and inhibiting the growth of A. carbonarius. Thus, perillaldehyde has the potential to be used as a natural fungicide or alternative food preservative in grapes and their products, owing to its strong antifungal and antimycotoxigenic effects on A. carbonarius.

With anthrax toxin as a pioneer, several bacterial toxins have been engineered to deliver proteins of interest into the cytosol of specific mammalian cells. Such targeted protein toxins combine the ability to deliver cargo molecules into cells with designed receptor interaction for targeting selected cells. This review summarizes the actual knowledge of modified anthrax toxin. Moreover, the significant efforts which have been made to utilize other bacterial toxins are discussed. The targeted protein toxins described in this review include single-chain toxins, pore-forming toxins, and injection machineries.

This study assessed mycotoxin contamination in roasted peanut snacks and kluiklui (fried pressed peanut cake), and consumer exposure in southern Benin. Roasted peanut snacks and kluiklui were sampled from markets across six municipalities, and their production follow-up was conducted on two sites using different processing methods. Mycotoxins were quantified using UPLC-MS/MS, while fungal species were identified via culture-based methods. Exposure to aflatoxin B1, total aflatoxins and ochratoxin A was estimated. Aflatoxin B1 predominated, reaching 169 µg/kg in roasted peanut snacks and 2144.64 µg/kg in marketed kluiklui. In contrast, just-produced kluiklui contained much lower levels (11.73-37.78 µg/kg). Aspergillus flavus and Aspergillus niger predominated in kluiklui from the first processing site, while Aspergillus chevalieri dominated in kluiklui from the second processing site. The grinding step (using public grinder) was identified as the main contamination point. The significative higher mycotoxin levels in kluiklui sampled on markets compared to just-produced kluiklui are probably due to poor storage conditions. Dietary exposure estimates revealed that margins of exposure for aflatoxins were far below the safety threshold of 10,000, and liver cancer risk estimates were particularly high for kluiklui consumers. Kluiklui consumption poses a significant health risk in Benin. Improved hygiene in public grinders and better storage practices are urgently needed to reduce contamination and protect consumers' health.

Aflatoxins (AFs) and fumonisins (FUMs) are among the most prevalent and toxic mycotoxins affecting maize production globally. In Mexico, their co-occurrence poses a significant public health concern, as maize is not only a dietary staple but also predominantly grown and consumed at the household level. This review examines the multifactorial nature of AFs and FUMs contamination in Mexican maize systems, considering the roles of maize germplasm, agricultural practices, environmental conditions, and soil microbiota. Maize landraces, well-adapted to diverse agroecological zones, exhibit potential resistance to AFs contamination and should be prioritized in breeding programs. Sustainable agricultural practices and biocontrol strategies, including the use of atoxigenic Aspergillus flavus strains, are presented as promising interventions. Environmental factors and soil characteristics further influence fungal proliferation and mycotoxin biosynthesis. Advances in microbiome engineering, biological breeding approaches, and predictive modeling offer novel opportunities for prevention and control. The synergistic toxicity of AFs and FUMs significantly increases health risks, particularly for liver cancer, highlighting the urgency of integrated mitigation strategies. While Mexico has regulatory limits for AFs, the lack of legal thresholds for FUMs remains a critical gap in food safety legislation. This comprehensive review underscores the need for biomarker-based exposure assessments and coordinated national policies, alongside multidisciplinary strategies to reduce mycotoxin exposure and enhance food safety in maize systems.

Staphylococcus aureus (S. aureus) is a major cause of human morbidity and mortality worldwide. Hemolysis caused by S. aureus cytotoxins is important for the acquisition of iron and subsequent bacterial survival during infection. S. aureus can express numerous hemolysins that have been shown to target human erythrocytes. However, the relative importance of each of these for causing hemolysis during pathogenesis in humans is not clear. In this study, we have examined the hemolytic capacity of different methicillin-resistant S. aureus (MRSA) deletion mutants against human erythrocytes in suspension using two separate assays. The first assay measured hemolysis caused by extracellular factors produced by MRSA, while the second measured hemolysis following co-culture of MRSA with human erythrocytes. Results from both assays demonstrated that phenol-soluble modulin-α peptides (PSMα) play a dominant role in causing hemolysis of human erythrocytes, highlighting a prominent target for novel therapeutic strategies designed to limit S. aureus iron acquisition and survival during human disease.

Cannabis plants are susceptible to microbial contamination, including fungi capable of producing harmful mycotoxins. The presence of these toxins in cannabis products poses serious health risks, especially when used for medical purposes in immunocompromised people. This study evaluated the presence of fungi and mycotoxins in dried cannabis buds following gamma irradiation, using culture-based techniques, PCR/qPCR, and ELISA. Irradiation significantly reduced fungal and bacterial loads, eliminating culturable bacteria but did not achieve complete sterilization. Viable spores of toxigenic fungal genera, such as Aspergillus, Penicillium, and Fusarium, persisted. Sequencing of ITS amplicons revealed dominant mycotoxigenic fungi in non-irradiated (NR), irradiated (IR) and licensed producer (LP) samples, while next-generation sequencing (NGS) revealed additional non-culturable toxigenic species. PCR/qPCR detected biosynthetic genes for aflatoxins, trichothecenes, ochratoxins, and deoxynivalenol across all samples, with gene copy numbers remaining stable post-irradiation, suggesting DNA damage without full degradation. ELISA confirmed aflatoxin, ochratoxin, DON, and T2 toxins in both IR and LP samples at variable concentrations. While LP samples showed lower microbial counts and gene abundance, residual DNA and toxins were still detected. Our study shows that while irradiation decreases microbial loads, it does not completely remove toxigenic fungi or their metabolites. Ensuring the safety of cannabis products necessitates a multifaceted assessment that incorporates cultural, molecular, and immunological techniques, in parallel with more stringent microbial standards during production stage.

Mycotoxin contamination is a global threat to food safety and human health, especially in regions facing food insecurity, such as Sub-Saharan Africa. This intervention study evaluates the effectiveness of nixtamalization, a traditional alkaline cooking method, in reducing mycotoxin levels in maize and corresponding urinary biomarkers of exposure. Forty adult healthy volunteers from an informal settlement in Kliptown, Soweto (South Africa), were randomly assigned to consume control maize or visibly moldy maize subjected to nixtamalization. Nixtamalization achieved a reduction in fumonisin B3 and deoxynivalenol (DON) to unquantifiable or undetectable levels in maize, while reducing fumonisin B1 (FB1), fumonisin B2, and zearalenone (ZEN) by 95%, 95%, and 89%, respectively. Aflatoxin B1 was unquantifiable before and eliminated after treatment. Biomarker analysis revealed that after consumption of either control or nixtamalized maize, urinary levels of FB1, ZEN, and its metabolites α- and β-zearalenol (α- and β-ZEL) did not show significant differences between groups (p > 0.05). DON and tenuazonic acid levels were not affected by the intervention (p > 0.05), with urinary detection frequencies remaining above 90%. These results demonstrate nixtamalization effectively lowers mycotoxin levels in maize, resulting in exposure levels comparable to control maize, and highlight human biomonitoring as a sensitive tool for evaluating food safety interventions.