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1.
Front Cell Infect Microbiol ; 14: 1372779, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38596652

RESUMO

Aflatoxins (AFs) are produced by fungi such as Aspergillus flavus and A. parasiticus and are one of the most toxic mycotoxins found in agricultural products and food. Aflatoxin contamination, which requires the control of A. flavus, remains problematic because of the lack of effective strategies and the exploration of new compounds that can inhibit A. flavus growth and mycotoxin production is urgently required to alleviate potential deleterious effects. Acetohydroxy acid synthase (AHAS) and dihydroxy acid dehydratase are important enzymes in the biosynthetic pathways of branched-chain amino acids (BCAAs), including isoleucine, leucine, and valine. Enzymes involved in BCAA biosynthesis are present in bacteria, plants, and fungi, but not in mammals, and are therefore, attractive targets for antimicrobial and herbicide development. In this study, we characterized AflaILVB/G/I and AflaILVD, which encode the catalytic and regulatory subunits of AHAS and dihydroxy acid dehydratase, from the pathogenic fungus Aspergillus flavus. The AflaILVB/G/I and AflaILVD deletion mutant grew slower and produced smaller colonies than the wild-type strain when grown on glucose minimal medium, potato dextrose agar, and yeast extract medium for three days at 28°C, and disruption of AflaILVB/G/I caused a significant reduction in conidia production when grown on all kinds of media. Cellular stress assays determined that all strains were sensitive to H2O2. Importantly, the pathogenicity and aflatoxin production were affected when AflaILVB/G/I and AflaILVD were knocked out, particularly AflaILVB/G/I. A series of genes that encoded enzymes involved in aflatoxin synthesis were downregulated, meaning that the knockout of AflaILVB/G/I influenced aflatoxin synthesis in A. flavus strain WT. Collectively, our results demonstrate the potential value of antifungals targeting AflaILVB/G/I in A. flavus.


Assuntos
Aflatoxinas , Aspergillus flavus , Animais , Aspergillus flavus/genética , Virulência , Peróxido de Hidrogênio/metabolismo , Hidroliases , Mamíferos
2.
Microbiol Res ; 283: 127710, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38593581

RESUMO

Aflatoxin B1 (AFB1), a highly toxic secondary metabolite produced by Aspergillus flavus, poses a severe threat to agricultural production, food safety and human health. The methylation of mRNA m6A has been identified as a regulator of both the growth and AFB1 production of A. flavus. However, its intracellular occurrence and function needs to be elucidated. Here, we identified and characterized a m6A methyltransferase, AflIme4, in A. flavus. The enzyme was localized in the cytoplasm, and knockout of AflIme4 significantly reduced the methylation modification level of mRNA. Compared with the control strains, ΔAflIme4 exhibited diminished growth, conidial formation, mycelial hydrophobicity, sclerotium yield, pathogenicity and increased sensitivity to CR, SDS, NaCl and H2O2. Notably, AFB1 production was markedly inhibited in the A. flavus ΔAflIme4 strain. RNA-Seq coupled with RT-qPCR validation showed that the transcriptional levels of genes involved in the AFB1 biosynthesis pathway including aflA, aflG, aflH, aflK, aflL, aflO, aflS, aflV and aflY were significantly upregulated. Methylated RNA immunoprecipitation-qPCR (MeRIP-qPCR) analysis demonstrated a significant increase in m6A methylation modification levels of these pathway-specific genes, concomitant with a decrease in mRNA stability. These results suggest that AflIme4 attenuates the mRNA stability of genes in AFB1 biosynthesis by enhancing their mRNA m6A methylation modification, leading to impaired AFB1 biosynthesis. Our study identifies a novel m6A methyltransferase AflIme4 and highlights it as a potential target to control A. flavus growth, development and aflatoxin pollution.


Assuntos
Aflatoxinas , Aspergillus flavus , Humanos , Aspergillus flavus/genética , Aflatoxina B1/genética , Aflatoxina B1/metabolismo , Metiltransferases/genética , Metiltransferases/metabolismo , Peróxido de Hidrogênio/metabolismo , RNA Mensageiro/metabolismo , Aflatoxinas/genética , Aflatoxinas/metabolismo
3.
Med Mycol ; 62(4)2024 Mar 28.
Artigo em Inglês | MEDLINE | ID: mdl-38578660

RESUMO

Aspergillus flavus is a commonly encountered pathogen responsible for fungal rhinosinusitis (FRS) in arid regions. The species is known to produce aflatoxins, posing a significant risk to human health. This study aimed to investigate the aflatoxin profiles of A. flavus isolates causing FRS in Sudan. A total of 93 clinical and 34 environmental A. flavus isolates were studied. Aflatoxin profiles were evaluated by phenotypic (thin-layer and high-performance chromatography) and genotypic methods at various temperatures and substrates. Gene expression of aflD and aflR was also analyzed. A total of 42/93 (45%) isolates were positive for aflatoxin B1 and AFB2 by HPLC. When the incubation temperature changed from 28°C to 36°C, the number of positive isolates decreased to 41% (38/93). Genetic analysis revealed that 85% (79/93) of clinical isolates possessed all seven aflatoxin biosynthesis-associated genes, while 27% (14/51) of non-producing isolates lacked specific genes (aflD/aflR/aflS). Mutations were observed in aflS and aflR genes across both aflatoxin-producers and non-producers. Gene expression of aflD and aflR showed the highest expression between the 4th and 6th days of incubation on the Sabouraud medium and on the 9th day of incubation on the RPMI (Roswell Park Memorial Institute) medium. Aspergillus flavus clinical isolates demonstrated aflatoxigenic capabilities, influenced by incubation temperature and substrate. Dynamic aflD and aflR gene expression patterns over time enriched our understanding of aflatoxin production regulation. The overall findings underscored the health risks of Sudanese patients infected by this species, emphasizing the importance of monitoring aflatoxin exposure.


Aspergillus flavus, mainly causing fungal rhinosinusitis in Sudan, poses health risks due to aflatoxin production. This study revealed diverse levels of aflatoxin and gene expression of clinical isolates by pheno- and genotypic methods, emphasizing the need for vigilant monitoring in the region.


Assuntos
Aflatoxinas , Aspergillus flavus , Sinusite , Aspergillus flavus/genética , Aspergillus flavus/isolamento & purificação , Aspergillus flavus/classificação , Sudão , Humanos , Sinusite/microbiologia , Aspergilose/microbiologia , Temperatura , Rinite/microbiologia , Genótipo , Proteínas Fúngicas/genética , 60523
4.
Food Res Int ; 184: 114256, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38609234

RESUMO

Mycotoxins are important risk factors in beer. In this study, a liquid chromatography tandem mass spectrometry (LC-MS/MS) method was developed to determine 10 mycotoxins in beer within 6 min. The method is fast, efficient, and has a simple and quick sample preparation. Validation was conducted based on the performance standards specified in Commission Decision 657/2002/EC, and the results demonstrated excellent linearity (R2 > 0.99), repeatability (RSD < 5 %), quantification limits (0.005-20.246 µg/L), and recovery rates (77 %-118 %). The prevalence of the 10 mycotoxins in 96 beers purchased from the Chinese market was analyzed, and the exposure of the Chinese population to mycotoxins through beer consumption was assessed. Deoxynivalenol (DON) was detected in 93.75 % of the beers, and the incidence of fumonisins (FBs) and zearalenone (ZEN) exceeded 50 %. Beer intake contributed significantly to the exposure of aflatoxins (AFs) and DON, especially in males. Correlation analysis between mycotoxin content in beer, raw materials, and the brewing process revealed that the brewing process significantly affected the content of DON (P < 0.001), while auxiliary materials also had a significant impact on the content of FBs and DON (P < 0.001). This study holds great significance in producing higher quality and safer beer.


Assuntos
Aflatoxinas , Micotoxinas , Masculino , Humanos , Cerveja , Cromatografia Líquida , Espectrometria de Massas em Tandem
5.
Environ Microbiol Rep ; 16(2): e13249, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38634243

RESUMO

Aspergillus flavus is the most frequently identified producer of aflatoxins. Non-aflatoxigenic members of the A. flavus L strains are used in various continents as active ingredients of bioprotectants directed at preventing aflatoxin contamination by competitive displacement of aflatoxin producers. The current research examined the genetic diversity of A. flavus L strain across southern Europe to gain insights into the population structure and evolution of this species and to evaluate the prevalence of genotypes closely related to MUCL54911, the active ingredient of AF-X1. A total of 2173L strain isolates recovered from maize collected across Greece, Spain, and Serbia in 2020 and 2021 were subjected to simple sequence repeat (SSR) genotyping. The analysis revealed high diversity within and among countries and dozens of haplotypes shared. Linkage disequilibrium analysis indicated asexual reproduction and clonal evolution of A. flavus L strain resident in Europe. Moreover, haplotypes closely related to MUCL54911 were found to belong to the same vegetative compatibility group (VCG) IT006 and were relatively common in all three countries. The results indicate that IT006 is endemic to southern Europe and may be utilized as an aflatoxin mitigation tool for maize across the region without concern for potential adverse impacts associated with the introduction of an exotic microorganism.


Assuntos
Aflatoxinas , Aspergillus flavus , Aflatoxinas/genética , Zea mays , Grécia , Espanha , Sérvia
6.
World J Microbiol Biotechnol ; 40(6): 164, 2024 Apr 17.
Artigo em Inglês | MEDLINE | ID: mdl-38630373

RESUMO

The aim of this study was to investigate the mechanisms by which yeasts (Saccharomyces cerevisiae) control the toxic effects of aflatoxins, which are not yet fully understood. Radiolabeled aflatoxin B1 (AFB13H) was administered by gavage to Wistar rats fed with aflatoxin (AflDiet) and aflatoxin supplemented with active dehydrated yeast Y904 (AflDiet + Yeast). The distribution of AFB13H and its metabolites were analyzed at 24, 48 and 72 h by tracking back of the radioactivity. No significant differences were observed between the AflDiet and AflDiet + Yeast groups in terms of the distribution of labeled aflatoxin. At 72 h, for the AflDiet group the radiolabeled aflatoxin was distributed as following: feces (79.5%), carcass (10.5%), urine (1.7%), and intestine (7.4%); in the AflDiet + Yeast the following distribution was observed: feces (76%), carcass (15%), urine (2.9%), and intestine (4.9%). These values were below 1% in other organs. These findings indicate that even after 72 h considerable amounts of aflatoxins remains in the intestines, which may play a significant role in the distribution and metabolism of aflatoxins and its metabolites over time. The presence of yeast may not significantly affect this process. Furthermore, histopathological examination of hepatic tissues showed that the presence of active yeast reduced the severity of liver damage caused by aflatoxins, indicating that yeasts control aflatoxin damage through biochemical mechanisms. These findings contribute to a better understanding of the mechanisms underlying the protective effects of yeasts against aflatoxin toxicity.


Assuntos
Aflatoxinas , Saccharomyces cerevisiae , Ratos , Animais , Ratos Wistar , Aflatoxinas/toxicidade , Suplementos Nutricionais , Fezes
7.
Toxins (Basel) ; 16(3)2024 Feb 29.
Artigo em Inglês | MEDLINE | ID: mdl-38535785

RESUMO

Magnetic molecularly imprinted polymers (MMIPs) have fused molecular imprinting technology with magnetic separation technology, emerging as an innovative material capable of recognizing specific molecules and efficiently separating target substances. Their application to the extraction and purification of mycotoxins has great potential, due to the toxicity and economic impact of these contaminants. In this work, MMIP has been proposed as a sample treatment for the determination of main four aflatoxins (B1, B2, G1 and G2) in pig feed. The MMIP was formed through the integration of magnetic material (Fe3O4) with commercial molecularly imprinted polymers, avoiding the synthesis step and, therefore, simplifying the process. The analyses were carried out by high-performance liquid chromatography with fluorescence detection and the method was validated and limits of quantification (LOQs) between 0.09 and 0.47 ng/g were obtained, below the allowed or recommended levels by the European Union. Repeatability and intermediate precision showed relative standard deviations lower than 10% in all cases and trueness ranged from 92 to 111%. Finally, the proposed method was applied to 31 real pig feed samples, detecting aflatoxins with concentrations between 0.2 and 3.2 ng/g.


Assuntos
Aflatoxinas , Micotoxinas , Animais , Suínos , Polímeros Molecularmente Impressos , Cromatografia Líquida de Alta Pressão , União Europeia
8.
Toxins (Basel) ; 16(3)2024 Mar 08.
Artigo em Inglês | MEDLINE | ID: mdl-38535807

RESUMO

During an experiment where we were cultivating aflatoxigenic Aspergillus flavus on peanuts, we accidentally discovered that a bacterium adhering to the peanut strongly inhibited aflatoxin (AF) production by A. flavus. The bacterium, isolated and identified as Klebsiella aerogenes, was found to produce an AF production inhibitor. Cyclo(l-Ala-Gly), isolated from the bacterial culture supernatant, was the main active component. The aflatoxin production-inhibitory activity of cyclo(l-Ala-Gly) has not been reported. Cyclo(l-Ala-Gly) inhibited AF production in A. flavus without affecting its fungal growth in a liquid medium with stronger potency than cyclo(l-Ala-l-Pro). Cyclo(l-Ala-Gly) has the strongest AF production-inhibitory activity among known AF production-inhibitory diketopiperazines. Related compounds in which the methyl moiety in cyclo(l-Ala-Gly) is replaced by ethyl, propyl, or isopropyl have shown much stronger activity than cyclo(l-Ala-Gly). Cyclo(l-Ala-Gly) did not inhibit recombinant glutathione-S-transferase (GST) in A. flavus, unlike (l-Ala-l-Pro), which showed that the inhibition of GST was not responsible for the AF production-inhibition of cyclo(l-Ala-Gly). When A. flavus was cultured on peanuts dipped for a short period of time in a dilution series bacterial culture broth, AF production in the peanuts was strongly inhibited, even at a 1 × 104-fold dilution. This strong inhibitory activity suggests that the bacterium is a candidate for an effective biocontrol agent for AF control.


Assuntos
Aflatoxinas , Aspergillus flavus , Klebsiella , Dipeptídeos , Arachis , Glutationa Transferase
9.
J Appl Microbiol ; 135(4)2024 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-38520150

RESUMO

AIMS: In this study, the control effects of synthetic microbial communities composed of peanut seed bacteria against seed aflatoxin contamination caused by Aspergillus flavus and root rot by Fusarium oxysporum were evaluated. METHODS AND RESULTS: Potentially conserved microbial synthetic communities (C), growth-promoting synthetic communities (S), and combined synthetic communities (CS) of peanut seeds were constructed after 16S rRNA Illumina sequencing, strain isolation, and measurement of plant growth promotion indicators. Three synthetic communities showed resistance to root rot and CS had the best effect after inoculating into peanut seedlings. This was achieved by increased defense enzyme activity and activated salicylic acid (SA)-related, systematically induced resistance in peanuts. In addition, CS also inhibited the reproduction of A. flavus on peanut seeds and the production of aflatoxin. These effects are related to bacterial degradation of toxins and destruction of mycelia. CONCLUSIONS: Inoculation with a synthetic community composed of seed bacteria can help host peanuts resist the invasion of seeds by A. flavus and seedlings by F. oxysporum and promote the growth of peanut seedlings.


Assuntos
Aflatoxinas , Sementes , RNA Ribossômico 16S/genética , Sementes/microbiologia , Fungos/genética , Plântula/microbiologia , Bactérias/genética , Arachis/microbiologia
10.
Int J Food Microbiol ; 416: 110661, 2024 May 02.
Artigo em Inglês | MEDLINE | ID: mdl-38457888

RESUMO

Aspergillus flavus and its toxic metabolites-aflatoxins infect and contaminate maize kernels, posing a threat to grain safety and human health. Due to the complexity of microbial growth and metabolic processes, dynamic mechanisms among fungal growth, nutrient depletion of maize kernels and aflatoxin production is still unclear. In this study, visible/near infrared (Vis/NIR) hyperspectral imaging (HSI) combined with the scanning electron microscope (SEM) was used to elucidate the critical organismal interaction at kernel (macro-) and microscopic levels. As kernel damage is the main entrance for fungal invasion, maize kernels with gradually aggravated damages from intact to pierced to halved kernels with A. flavus were cultured for 0-120 h. The spectral fingerprints of the A. flavus-maize kernel complex over time were analyzed with principal components analysis (PCA) of hyperspectral images, where the pseudo-color score maps and the loading plots of the first three PCs were used to investigate the dynamic process of fungal infection and to capture the subtle changes in the complex with different hardness of the maize matrix. The dynamic growth process of A. flavus and the interactions of fungus-maize complexes were explained on a microscopic level using SEM. Specifically, fungus morphology, e.g., hyphae, conidia, and conidiophore (stipe) was accurately captured on the microscopic level, and the interaction process between A. flavus and nutrient loss from the maize kernel tissues (i.e., embryo, and endosperm) was described. Furthermore, the growth stage discrimination models based on PLSDA with the results of CCRC = 100 %, CCRV = 97 %, CCRIV = 93 %, and the prediction models of AFB1 based on PLSR with satisfactory performance (R2C = 0.96, R2V = 0.95, R2IV = 0.93 and RPD = 3.58) were both achieved. In conclusion, the results from both macro-level (Vis/NIR-HSI) and micro-level (SEM) assessments revealed the dynamic organismal interactions in A. flavus-maize kernel complex, and the detailed data could be used for modeling, and quantitative prediction of aflatoxin, which would establish a theoretical foundation for the early detection of fungal or toxin contaminated grains to ensure food security.


Assuntos
Aflatoxinas , Aspergillus flavus , Humanos , Aspergillus flavus/metabolismo , Zea mays/microbiologia , Imageamento Hiperespectral , Tecnologia
11.
J Hazard Mater ; 469: 133916, 2024 May 05.
Artigo em Inglês | MEDLINE | ID: mdl-38479137

RESUMO

Aflatoxins from the fungus Aspergillus flavus (A. flavus) that contaminate stored peanuts is a major hazard to human health worldwide. Reducing A. flavus in soil can decrease the risk of aflatoxins in stored peanuts. In this experiment, we determined whether peanuts grown on soil fumigated with dazomet (DZ), metham sodium (MS), allyl isothiocyanate (AITC), chloropicrin (PIC) or dimethyl disulfide (DMDS) would reduce of the quantity of A. flavus and its toxin's presence. The results of bioassays and field tests showed that PIC was the most effective fumigant for preventing and controlling A. flavus, followed by MS. PIC and MS applied to the soil for 14 d resulted in LD50 values against A. flavus of 3.558 and 4.893 mg kg-1, respectively, leading to almost 100% and 98.82% effectiveness of A. flavus, respectively. Peanuts harvested from fumigated soil and then stored for 60 d resulted in undetectable levels of aflatoxin B1 (AFB1) compared to unfumigated soil that contained 0.64 ug kg-1 of AFB1, which suggested that soil fumigation can reduce the probability of aflatoxin contamination during peanut storage and showed the potential to increase the safety of peanuts consumed by humans. Further research is planned to determine the practical value of our research in commercial practice.


Assuntos
Aflatoxina B1 , Aflatoxinas , Humanos , Aflatoxina B1/toxicidade , Aflatoxina B1/análise , Arachis , Solo , Desinfecção , Aspergillus flavus , Aflatoxinas/toxicidade , Aflatoxinas/análise
12.
Sci Rep ; 14(1): 6864, 2024 03 22.
Artigo em Inglês | MEDLINE | ID: mdl-38514765

RESUMO

Aflatoxin B1 (AFB1) is widespread and seriously threatens public health worldwide. This study aimed to investigate AFB1 in imported hazelnut samples in northwest of Iran (Eastern Azerbaijan Province) using High-Performance Liquid Chromatography with a Fluorescent Detector (HPLC-FLD). In all tested samples AFB1 was detected. The mean concentration of AFB1 was 4.20 µg/kg and ranged from 3.145 to 8.13 µg/kg. All samples contained AFB1 levels within the maximum acceptable limit except for one sample. Furthermore, the human health risk assessment of AFB1 from consuming imported hazelnuts by Iranian children and adults was evaluated based on the margin of exposure (MoE) and quantitative liver cancer risk approaches. The MoE mean for children was 2529.76, while for adults, it was 8854.16, indicating a public health concern. The present study found that the risk of developing liver cancer among Iranian children was 0.11100736 per 100,000 people, and in the Iranian adult population was 0.0314496 cancers per 100,000 people. Since environmental conditions potentially affect aflatoxin levels in nuts, countries are advised to monitor aflatoxin contents in imported nuts, especially from countries with a conducive climate for mold growth.


Assuntos
Aflatoxinas , Corylus , Neoplasias Hepáticas , Adulto , Criança , Humanos , Aflatoxina B1/análise , Irã (Geográfico)/epidemiologia , Azerbaijão , Contaminação de Alimentos/análise , Aflatoxinas/análise , Medição de Risco , Cromatografia Líquida de Alta Pressão/métodos
13.
Environ Int ; 185: 108537, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38452463

RESUMO

This study aimed to present the occurrence of sixteen mycotoxins in 105 meat alternatives based on wheat, legumes, and vegetables from Italy. The targeted mycotoxins were aflatoxins (AFB1, AFB2, AFG1, AFG2), fumonisins B1 and B2 (FB1, FB2), alternariol (AOH), alternariol monomethyl ether (AME), tentoxin (TEN), ochratoxin A (OTA), zearalenone (ZEN), T-2/HT-2 toxin, deoxynivalenol (DON), enniatin B (ENNB), and beauvericin (BEA). The occurrence of mycotoxins was between 0% (AFB2) - 97.4% (ENNB). Mycotoxin co-occurrence varied from binary combinations up to mixtures of twelve. To assess the dietary exposure and potential health risks we simulated the replacement of meat consumption for Italian consumers with meat alternatives. The cumulative exposure to Alternaria mycotoxins and trichothecenes indicated a potential health risk while the exposure to aflatoxins and ochratoxin A indicated a potential health concern related to liver and renal cancer in the model scenario. Moreover, we estimated the risk of liver cancer from exposure to AFB1 and quantified the potential burden using Disability-Adjusted Life Years (DALYs). Luckily, the potential risk of liver cancer was low between 0 and 0.05/100,000 individuals with an associated burden of disease of 0.83 DALYs/100,000 individuals. Taking into consideration the presence of meat alternatives on the food market and the ongoing shift towards plant-based diets there is a need for continuous monitoring to keep the occurrence at safe levels. More attention is needed from the regulatory side for policymakers to consider the legislations of mycotoxins in meat alternatives.


Assuntos
Aflatoxinas , Neoplasias Hepáticas , Micotoxinas , Toxina T-2 , Humanos , Micotoxinas/efeitos adversos , Exposição Dietética/efeitos adversos , 60450 , Contaminação de Alimentos/análise , Efeitos Psicossociais da Doença
14.
Arch Toxicol ; 98(4): 1081-1093, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38436695

RESUMO

Large interspecies differences between rats and mice concerning the hepatotoxicity and carcinogenicity of aflatoxin B1 (AFB1) are known, with mice being more resistant. However, a comprehensive interspecies comparison including subcellular liver tissue compartments has not yet been performed. In this study, we performed spatio-temporal intravital analysis of AFB1 kinetics in the livers of anesthetized mice and rats. This was supported by time-dependent analysis of the parent compound as well as metabolites and adducts in blood, urine, and bile of both species by HPLC-MS/MS. The integrated data from intravital imaging and HPLC-MS/MS analysis revealed major interspecies differences between rats and mice: (1) AFB1-associated fluorescence persisted much longer in the nuclei of rat than mouse hepatocytes; (2) in the sinusoidal blood, AFB1-associated fluorescence was rapidly cleared in mice, while a time-dependent increase was observed in rats in the first three hours after injection followed by a plateau that lasted until the end of the observation period of six hours; (3) this coincided with a far stronger increase of AFB1-lysine adducts in the blood of rats compared to mice; (4) the AFB1-guanine adduct was detected at much higher concentrations in bile and urine of rats than mice. In both species, the AFB1-glutathione conjugate was efficiently excreted via bile, where it reached concentrations at least three orders of magnitude higher compared to blood. In conclusion, major differences between mice and rats were observed, concerning the nuclear persistence, formation of AFB1-lysine adducts, and the AFB1-guanine adducts.


Assuntos
Aflatoxinas , Ratos , Camundongos , Animais , Aflatoxinas/metabolismo , Aflatoxinas/toxicidade , Lisina/metabolismo , 60705 , Espectrometria de Massas em Tandem , Fígado/metabolismo , Aflatoxina B1/toxicidade , Guanina/metabolismo , Microscopia Intravital
15.
Mycotoxin Res ; 40(2): 309-318, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38530632

RESUMO

Aflatoxins are one of the major factors that affect the quality and safety of feeds. They can be transferred into livestock through contaminated feed and then onto humans via animal sources of food such as milk, meat, and eggs. The objective of this study was to detect and quantify the level of aflatoxins (B1, B2, G1, G2, and total aflatoxin) in dairy feeds, poultry (layer and broiler) feeds, and feed ingredients produced in Addis Ababa. A total of 42 feeds and feed ingredients consisting of dairy feeds (n = 5), poultry broiler feeds (n = 6), layer feeds (n = 6), and feed ingredients (n = 25) were collected from feed factories in the city and analyzed in fresh weigh basis. The aflatoxins were analyzed using high-performance liquid chromatography after clean-up with immunoaffinity columns. Aflatoxin B1 levels in feeds ranged from 51.66 to 370.51 µg/kg in dairy cattle feed, from 1.45 to 139.51 µg/kg in poultry layer feed, and from 16.49 to 148.86 µg/kg in broiler feed. Aflatoxin B1 levels in maize ranged from 2.64 to 46.74 µg/kg and in Niger seed cake from 110.93 to 438.86 µg/kg. Aflatoxin B1 levels in wheat bran, wheat middling, and soybean were below 5 µg/kg. 100% of dairy feeds, 67% of poultry layer, 67% of broiler feeds, and 24% of ingredients contained aflatoxin in levels higher than the maximum tolerable limit set by the US Food and Drug Administration and Ethiopian Standard Agency. This shows the need for strong regulatory monitoring and better feed management practices to prevent consumers of animal-source foods from significant health impacts associated with aflatoxins.


Assuntos
Aflatoxinas , Ração Animal , Contaminação de Alimentos , Aves Domésticas , Ração Animal/análise , Animais , Etiópia , Aflatoxinas/análise , Contaminação de Alimentos/análise , Bovinos , Galinhas , Cromatografia Líquida de Alta Pressão/métodos
16.
BMC Vet Res ; 20(1): 108, 2024 Mar 18.
Artigo em Inglês | MEDLINE | ID: mdl-38500117

RESUMO

BACKGROUND: Camel milk and silymarin have many different beneficial effects on several animal species. Meanwhile, Aflatoxins are mycotoxins with extraordinary potency that pose major health risks to several animal species. Additionally, it has been documented that aflatoxins harm the reproductive systems of a variety of domestic animals. The present design aimed to investigate the impact of aflatoxin B1 (AFB1) on rat body weight and reproductive organs and the ameliorative effects of camel milk and silymarin through measured serum testosterone, testes pathology, and gene expression of tumor necrosis factor (TNF-α), luteinizing hormone receptor (LHR), and steroidogenic acute regulatory protein (StAR) in the testes. A total of sixty mature male Wister white rats, each weighing an average of 83.67 ± 0.21 g, were used. There were six groups created from the rats. Each division had ten rats. The groups were the control (without any treatment), CM (1 ml of camel milk/kg body weight orally), S (20 mg silymarin/kg b. wt. suspension, orally), A (1.4 mg aflatoxin/kg diet), ACM (aflatoxin plus camel milk), and AS (aflatoxin plus silymarin). RESULTS: The results indicated the positive effects of camel milk and silymarin on growth, reproductive organs, and gene expression of TNF-α, LHR, and StAR with normal testicular architecture. Also, the negative effect of AFB1 on the rat's body weight and reproductive organs, as indicated by low body weight and testosterone concentration, was confirmed by the results of histopathology and gene expression. However, these negative effects were ameliorated by the ingestion of camel milk and silymarin. CONCLUSION: In conclusion, camel milk and silymarin could mitigate the negative effect of AFB1 on rat body weight and reproductive organs.


Assuntos
Aflatoxinas , Silimarina , Masculino , Ratos , Animais , Aflatoxina B1/toxicidade , Aflatoxina B1/metabolismo , Silimarina/farmacologia , Camelus , Leite , Fator de Necrose Tumoral alfa/metabolismo , Ratos Wistar , Testículo/metabolismo , Testosterona/metabolismo , Peso Corporal
17.
Int J Mol Sci ; 25(5)2024 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-38474096

RESUMO

Aflatoxins are harmful natural contaminants found in foods and are known to be hepatotoxic. However, recent studies have linked chronic consumption of aflatoxins to nephrotoxicity in both animals and humans. Here, we conducted a systematic review of active compounds, crude extracts, herbal formulations, and probiotics against aflatoxin-induced renal dysfunction, highlighting their mechanisms of action in both in vitro and in vivo studies. The natural products and dietary supplements discussed in this study alleviated aflatoxin-induced renal oxidative stress, inflammation, tissue damage, and markers of renal function, mostly in animal models. Therefore, the information provided in this review may improve the management of kidney disease associated with aflatoxin exposure and potentially aid in animal feed supplementation. However, future research is warranted to translate the outcomes of this study into clinical use in kidney patients.


Assuntos
Aflatoxinas , Produtos Biológicos , Nefropatias , Animais , Humanos , Aflatoxinas/toxicidade , Aflatoxina B1/toxicidade , Suplementos Nutricionais
18.
Artigo em Inglês | MEDLINE | ID: mdl-38315775

RESUMO

Garri is a granular, starchy food prepared by the fermentation of mashed cassava. Hydrogen cyanide (HCN) and mycotoxins are contaminants in certain foods at different points along the food value chain. The incidence and contamination levels of HCN and multi-mycotoxins in garri from five agroecological zones of Nigeria were determined using a spectrophotometric method and ultra-high-performance liquid chromatography-tandem mass spectroscopy (UHPLC-MS/MS), respectively. The health risk associated with the consumption of contaminated garri was assessed. The health risk assessment model was used to calculate the dietary exposure of humans to the mycotoxins in garri. This was done by estimating the daily intake (EDI), the percentage tolerable daily intake (%TDI), the annual hepatocellular carcinoma (HCC) cases attributable to exposure to aflatoxins (AFs) in garri, as well as the HCC risk. The average intake of garri was estimated at 0.303 kg/day for a Nigerian adult. The incidence of HCN was 98.3% (0.056-2.463 mg/kg), and fermentation reduced the HCN level in garri more than other processing steps. The twenty-one mycotoxins identified and quantified were all within maximum levels, as applicable to those that are regulated by the EU. The %TDI for the other mycotoxins, with the exception of AFs, showed no alarming health risk with garri consumption. Annual HCC cases resulting from AF in garri were estimated at 10-60 cases for HBsAg + ve individuals and 4-23 cases for HBsAg - ve individuals based on 8.1% hepatitis B virus (HBV) incidence. Results further revealed no interdependence between HCN levels and mycotoxin content. This work suggests an unlikely chance of acute toxicity from HCN and major mycotoxins from a garri-based diet in Nigeria. Hence, it is recommended that concerned regulatory bodies maintain the existing permissible limits for HCN in Garri.


Assuntos
Aflatoxinas , Carcinoma Hepatocelular , Neoplasias Hepáticas , Micotoxinas , Adulto , Humanos , Micotoxinas/análise , Cianeto de Hidrogênio , Espectrometria de Massas em Tandem , Antígenos de Superfície da Hepatite B , Incidência , Neoplasias Hepáticas/epidemiologia , Aflatoxinas/análise , Contaminação de Alimentos/análise , Medição de Risco
19.
Biotechnol J ; 19(2): e2300675, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38404053

RESUMO

Aureobasidium melanogenum was found to be grown the best at the constant pH 7.0 and to produce the highest amount of liamocins at the constant pH 3.0. Therefore, the wild type strain A. melanogenum 9-1 and the engineered strain V33 constructed in the laboratory were grown at the constant pH 7.0 for 48 h, then, they were continued to be cultivated at the constant pH 3.0. Under such conditions, A. melanogenum 9-1 produced 36.51 ± 0.55 g L-1 of liamocin and its cell mass was 27.43 ± 0.63 and 6.00 ± 0.11 g L-1 of glucose was left in the finished medium within 168 h while the engineered strain V33 secreted 70.86 ± 2.04 g L-1 of liamocin, its cell mass was 31.63 ± 0.74 g L-1 , 0.16 ± 0.01 g L-1 of glucose was maintained in the finished medium. Then, Massoia lactone was released from the produced liamocins. The released Massoia lactone loaded in the nanoemulsions could be used to actively damage cell wall and cell membrane of both spores and mycelia of Aspergillus flavus, leading to its cell necrosis. Massoia lactone loaded in the nanoemulsions also actively inhibited cell growth of A. flavus, its conidia production and aflatoxin biosynthesis on peanuts, indicating that Massoia lactone loaded in the nanoemulsions had highly potential application in controlling cell growth of A. flavus and aflatoxin biosynthesis in foods and feedstuffs.


Assuntos
Aflatoxinas , Aspergillus flavus , Aspergillus flavus/genética , Aspergillus flavus/metabolismo , Fermentação , Lactonas/metabolismo , Aflatoxinas/metabolismo , Concentração de Íons de Hidrogênio , Glucose/metabolismo
20.
J Hazard Mater ; 467: 133755, 2024 Apr 05.
Artigo em Inglês | MEDLINE | ID: mdl-38359765

RESUMO

Covalent organic frameworks (COFs) are promising adsorbents for extraction, but their selectivity for molecular recognition remains a challenging issue due to the very limited structural design with rigid structure. Herein, we report an elegant strategy for the design and synthesis of molecularly imprinted flexible COFs (MI-FCOFs) via one-pot reaction between the flexible building block of 2,4,6-tris(4-formylphenoxy)- 1,3,5-triazine and linear 4-phenylenediamine for selective extraction of aflatoxins. The flexible chain structure enabled the developed MI-FCOF to adjust the shape and conformation of frameworks to suit the template molecule, giving high selectivity for aflatoxins recognition. Moreover, MI-FCOF with abundant imprinted sites and function groups exhibited an exceptional adsorption capacity of 258.4 mg g-1 for dummy template which is 3 times that of no-imprinted FCOF (NI-FCOF). Coupling MI-FCOF based solid-phase extraction with high-performance liquid chromatography gave low detection limits of 0.003-0.09 ng mL-1 and good precision with relative standard deviations ≤ 6.7% for the determination of aflatoxins. Recoveries for the spiked rice, corn, wheat and peanut samples were in the range of 85.4%- 105.4%. The high selectivity of the developed MI-FCOF allows matrix-free determination of AFTs in food samples. This work offers a new way to the design of MI-FCOF for selective molecular recognition.


Assuntos
Aflatoxinas , Estruturas Metalorgânicas , Impressão Molecular , Adsorção , Arachis
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