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Toxins Feb 2020The study of fungal species evolved radically with the development of molecular techniques and produced new evidence to understand specific fungal mechanisms such as the... (Review)
Review
The study of fungal species evolved radically with the development of molecular techniques and produced new evidence to understand specific fungal mechanisms such as the production of toxic secondary metabolites. Taking advantage of these technologies to improve food safety, the molecular study of toxinogenic species can help elucidate the mechanisms underlying toxin production and enable the development of new effective strategies to control fungal toxicity. Numerous studies have been made on genes involved in aflatoxin B1 (AFB1) production, one of the most hazardous carcinogenic toxins for humans and animals. The current review presents the roles of these different genes and their possible impact on AFB1 production. We focus on the toxinogenic strains and primary contaminants and major producers of AFB1 in crops. However, genetic reports on are also included because of the capacity of this fungus to produce sterigmatocystin, the penultimate stable metabolite during AFB1 production. The aim of this review is to provide a general overview of the AFB1 enzymatic biosynthesis pathway and its link with the genes belonging to the AFB1 cluster. It also aims to illustrate the role of global environmental factors on aflatoxin production and the recent data that demonstrate an interconnection between genes regulated by these environmental signals and aflatoxin biosynthetic pathway.
Topics: Aflatoxins; Animals; Gene-Environment Interaction; Humans
PubMed: 32121226
DOI: 10.3390/toxins12030150 -
Toxins Apr 2022Aflatoxin, a type of mycotoxin, is mostly produced by and It is responsible for the loss of billions of dollars to the world economy, by contaminating different crops... (Review)
Review
Aflatoxin, a type of mycotoxin, is mostly produced by and It is responsible for the loss of billions of dollars to the world economy, by contaminating different crops such as cotton, groundnut, maize, and chilies, and causing immense effects on the health of humans and animals. More than eighteen different types of aflatoxins have been reported to date, and among them, aflatoxins B1, B2, G1, and G2 are the most prevalent and lethal. Early detection of fungal infection plays a key role in the control of aflatoxin contamination. Therefore, different methods, including culture, chromatographic techniques, and molecular assays, are used to determine aflatoxin contamination in crops and food products. Many countries have set a maximum limit of aflatoxin contamination (2-20 ppb) in their food and agriculture commodities for human or animal consumption, and the use of different methods to combat this menace is essential. Fungal infection mostly takes place during the pre- and post-harvest stage of crops, and most of the methods to control aflatoxin are employed for the latter phase. Studies have shown that if correct measures are adopted during the crop development phase, aflatoxin contamination can be reduced by a significant level. Currently, the use of bio-pesticides is the intervention employed in many countries, whereby atoxigenic strains competitively reduce the burden of toxigenic strains in the field, thereby helping to mitigate this problem. This updated review on aflatoxins sheds light on the sources of contamination, and the on occurrence, impact, detection techniques, and management strategies, with a special emphasis on bio-pesticides to control aflatoxins.
Topics: Aflatoxins; Animals; Aspergillus flavus; Crops, Agricultural; Pesticides; Zea mays
PubMed: 35622554
DOI: 10.3390/toxins14050307 -
Toxins Jun 2021In the early 1960s the discovery of aflatoxins began when a total of 100,000 turkey poults died by hitherto unknown turkey "X" disease in England. The disease was... (Review)
Review
In the early 1960s the discovery of aflatoxins began when a total of 100,000 turkey poults died by hitherto unknown turkey "X" disease in England. The disease was associated with Brazilian groundnut meal affected by . The toxin was named toxin-aflatoxin. From the point of view of agriculture, aflatoxins show the utmost importance. Until now, a total of 20 aflatoxins have been described, with B, B, G, and G aflatoxins being the most significant. Contamination by aflatoxins is a global health problem. Aflatoxins pose acutely toxic, teratogenic, immunosuppressive, carcinogenic, and teratogenic effects. Besides food insecurity and human health, aflatoxins affect humanity at different levels, such as social, economical, and political. Great emphasis is placed on aflatoxin mitigation using biocontrol methods. Thus, this review is focused on aflatoxins in terms of historical development, the principal milestones of aflatoxin research, and recent data on their toxicity and different ways of mitigation.
Topics: Aflatoxins; Animals; Food Contamination; History, 20th Century; History, 21st Century; Humans
PubMed: 34205163
DOI: 10.3390/toxins13060399 -
Cells Sep 2022is a representative fungal species in the section Flavi and has been used as a model system to gain insights into fungal development and toxin production. has several... (Review)
Review
is a representative fungal species in the section Flavi and has been used as a model system to gain insights into fungal development and toxin production. has several adverse effects on humans, including the production of the most carcinogenic mycotoxin aflatoxins and causing aspergillosis in immune-compromised patients. In addition, infection of crops results in economic losses due to yield loss and aflatoxin contamination. is a saprophytic fungus that disperses in the ecosystem mainly by producing asexual spores (conidia), which also provide long-term survival in the harsh environmental conditions. Conidia are composed of the rodlet layer, cell wall, and melanin and are produced from an asexual specialized structure called the conidiophore. The production of conidiophores is tightly regulated by various regulators, including the central regulatory cascade composed of BrlA-AbaA-WetA, the fungi-specific velvet regulators, upstream regulators, and developmental repressors. In this review, we summarize the findings of a series of recent studies related to asexual development in and provide insights for a better understanding of other fungal species in the section Flavi.
Topics: Aflatoxins; Aspergillus flavus; Ecosystem; Fungal Proteins; Gene Expression Regulation, Fungal; Humans; Melanins; Spores, Fungal
PubMed: 36139369
DOI: 10.3390/cells11182796 -
Toxins Jan 2021Mycotoxin contamination causes significant economic loss to food and feed industries and seriously threatens human health. Aflatoxins (AFs) are one of the most harmful... (Review)
Review
Mycotoxin contamination causes significant economic loss to food and feed industries and seriously threatens human health. Aflatoxins (AFs) are one of the most harmful mycotoxins, which are produced by , , and other fungi that are commonly found in the production and preservation of grain and feed. AFs can cause harm to animal and human health due to their toxic (carcinogenic, teratogenic, and mutagenic) effects. How to remove AF has become a major problem: biological methods cause no contamination, have high specificity, and work at high temperature, affording environmental protection. In the present research, microorganisms with detoxification effects researched in recent years are reviewed, the detoxification mechanism of microbes on AFs, the safety of degrading enzymes and reaction products formed in the degradation process, and the application of microorganisms as detoxification strategies for AFs were investigated. One of the main aims of the work is to provide a reliable reference strategy for biological detoxification of AFs.
Topics: Aflatoxins; Animals; Food Contamination; Humans; Lactobacillus; Saccharomyces
PubMed: 33435382
DOI: 10.3390/toxins13010046 -
Toxins Jul 2023Aflatoxins are potent carcinogenic compounds, mainly produced by fungi species of the genus in the soil. Because of their stability, they are difficult to remove... (Review)
Review
Aflatoxins are potent carcinogenic compounds, mainly produced by fungi species of the genus in the soil. Because of their stability, they are difficult to remove completely, even under extreme conditions. Aflatoxin contamination is one of the main causes of safety in peanuts, maize, wheat and other agricultural products. Aflatoxin contamination originates from the soil. Through the investigation of soil properties and soil microbial distribution, the sources of aflatoxin are identified, aflatoxin contamination is classified and analysed, and post-harvest crop detoxification and corresponding contamination prevention measures are identified. This includes the team's recent development of the biofungicide ARC-BBBE (Aflatoxin Rhizobia Couple-, . , . , . ) for field application and nanomaterials for post-production detoxification of cereals and oilseed crops, providing an effective and feasible approach for the prevention and control of aflatoxin contamination. Finally, it is hoped that effective preventive and control measures can be applied to a large number of cereal and oilseed crops.
Topics: Aflatoxins; Soil; Aflatoxin B1; Agriculture; Arachis; Crops, Agricultural; Edible Grain
PubMed: 37624232
DOI: 10.3390/toxins15080475 -
Molecular Medicine Reports Mar 2020Achalasia is characterized by impaired swallowing due to lower esophageal sphincter (LES) dysfunction and an increased risk of esophageal carcinoma. Aflatoxin is a known... (Clinical Trial)
Clinical Trial
Achalasia is characterized by impaired swallowing due to lower esophageal sphincter (LES) dysfunction and an increased risk of esophageal carcinoma. Aflatoxin is a known carcinogen. Esophageal retention is relieved by per oral endoscopic myotomy (POEM), which lowers the esophageal cancer risk. The present study determined whether aflatoxin is involved in the pathogenesis of achalasia or esophageal cancer. A total of 75 patients with achalasia were prospectively enrolled from a tertiary center. Aflatoxin levels in their esophageal contents were measured using ELISA, and esophageal mucosal specimens were immunohistochemically evaluated for Ki67 and p53 expression prior to and 3 months after POEM. The effect of aflatoxin on esophageal contractility was assessed using murine specimens. Aflatoxin was detected in 67 patients before POEM and only 2 patients after POEM. The number of Ki67‑ and p53‑immunopositive cells in the esophageal mucosa significantly decreased after POEM: [Ki67: 27.8% (95% confidence interval (CI), 25.98‑29.70) vs. 20.7% (95% CI, 19.78‑24.03), P=0.04 and p53: 2.14% (95% CI, 1.85‑2.41) vs. 1.45% (95% CI, 1.22‑1.68), P=0.03]. In vitro experiments revealed that 500 ng/ml aflatoxin significantly increased the amplitude (P<0.05) and frequency (P<0.05) of spontaneous LES contractions compared with the control group. These increases were blocked by co‑treatment with atropine sulfate (P<0.05), but not with a nitric oxide synthase inhibitor (P>0.05). Aflatoxin was found in most patients with achalasia and was eliminated following POEM. Reduced Ki67 and p53 expression after POEM indicated a decreased risk of carcinogenesis. Aflatoxin accumulation increased LES contractility via cholinergic signaling. Therefore, aflatoxin may maintain achalasia symptoms and increase esophageal cancer risk.
Topics: Adolescent; Adult; Aflatoxins; Aged; Aged, 80 and over; Animals; Esophageal Achalasia; Esophageal Mucosa; Esophageal Neoplasms; Female; Humans; Male; Mice; Middle Aged; Prospective Studies; Pyloromyotomy; Risk Factors
PubMed: 31922241
DOI: 10.3892/mmr.2020.10914 -
Toxins Apr 2021Aflatoxins are poisonous carcinogens produced by fungi, mainly and . Aflatoxins can contaminate a variety of livestock feeds and cause enormous economic losses,... (Review)
Review
Aflatoxins are poisonous carcinogens produced by fungi, mainly and . Aflatoxins can contaminate a variety of livestock feeds and cause enormous economic losses, estimated at between US$52.1 and US$1.68 billion annually for the U.S. corn industry alone. In addition, aflatoxin can be transferred from the diet to the milk of cows as aflatoxin M1 (AFM1), posing a significant human health hazard. In dairy cows, sheep and goats, chronic exposure to dietary aflatoxin can reduce milk production, impair reproduction and liver function, compromise immune function, and increase susceptibility to diseases; hence, strategies to lower aflatoxin contamination of feeds and to prevent or reduce the transfer of the toxin to milk are required for safeguarding animal and human health and improving the safety of dairy products and profitability of the dairy industry. This article provides an overview of the toxicity of aflatoxin to ruminant livestock, its occurrence in livestock feeds, and the effectiveness of different strategies for preventing and mitigating aflatoxin contamination of feeds.
Topics: Aflatoxins; Animal Feed; Animal Husbandry; Animals; Cattle; Dairying; Female; Food Contamination; Food Microbiology; Food Supply; Humans; Milk; Risk Assessment
PubMed: 33920591
DOI: 10.3390/toxins13040283 -
Toxins Mar 2023Aflatoxins (AFs) represent one of the main mycotoxins produced by Aspergillus flavus and Aspergillus parasiticus, with the most prevalent and lethal subtypes being AFB1,... (Review)
Review
Aflatoxins (AFs) represent one of the main mycotoxins produced by Aspergillus flavus and Aspergillus parasiticus, with the most prevalent and lethal subtypes being AFB1, AFB2, AFG1, and AFG2. AFs are responsible for causing significant public health issues and economic concerns that affect consumers and farmers globally. Chronic exposure to AFs has been linked to liver cancer, oxidative stress, and fetal growth abnormalities among other health-related risks. Although there are various technologies, such as physical, chemical, and biological controls that have been employed to alleviate the toxic effects of AF, there is still no clearly elucidated universal method available to reduce AF levels in food and feed; the only mitigation is early detection of the toxin in the management of AF contamination. Numerous detection methods, including cultures, molecular techniques, immunochemical, electrochemical immunosensor, chromatographic, and spectroscopic means, are used to determine AF contamination in agricultural products. Recent research has shown that incorporating crops with higher resistance, such as sorghum, into animal feed can reduce the risk of AF contamination in milk and cheese. This review provides a current overview of the health-related risks of chronic dietary AF exposure, recent detection techniques, and management strategies to guide future researchers in developing better detection and management strategies for this toxin.
Topics: Animals; Aflatoxins; Biosensing Techniques; Food Contamination; Immunoassay; Aspergillus flavus
PubMed: 37104184
DOI: 10.3390/toxins15040246 -
Ghana Medical Journal Dec 2021The main aim of this study was to investigate levels of total aflatoxin and aflatoxin M in bokina, a home-made non-alcoholic beverage prepared from dairy milk, millet...
OBJECTIVE
The main aim of this study was to investigate levels of total aflatoxin and aflatoxin M in bokina, a home-made non-alcoholic beverage prepared from dairy milk, millet and sugar.
METHODS
Bokina, dairy milk and millet were purchased monthly over a period of 7 months from bokina producers at Ashaiman and Nima, in Ghana. Total aflatoxin and aflatoxin M levels in these samples were measured using a fluorometric procedure and High-Performance Liquid Chromatography.
RESULTS
Aflatoxin levels in bokina samples ranged from 1.0 to 21.0 ppb for Ashaiman samples and 1.0 to 23.0 ppb for Nima samples. Out of 21 samples from each site 1 from Ashiaman and 2 from Nima had levels total aflatoxin above the acceptable limit of 20 ppb. Similarly, total aflatoxin levels millet samples ranged from 1.0 to 55.0 ppb for Ashaiman and 5.0 to 53.0 ppb for Nima samples, with 2 samples from Ashiaman and 6 from Nima having levels above 20ppb. The levels of Aflatoxin M in milk ranged from 0.09 to 6.20 ppb for Ashaiman samples and 0.13 to 12.55 ppb for Nima samples. Out of the samples, 12 from Ashiaman and 10 from Nima (n=21) had levels of Aflatoxin M above the acceptable limit of 0.5 ppb.
CONCLUSION
Bokina samples tested were contaminated with aflatoxin. All doses of aflatoxin have a cumulative effect on the risk of cancer. Therefore, farmers and bokina producers must be educated on good storage practices and monitored to protect the public from aflatoxin exposure and toxicity.
FUNDING
The study was self-funded.
Topics: Aflatoxin M1; Aflatoxins; Animals; Food Contamination; Ghana; Humans; Milk
PubMed: 35957926
DOI: 10.4314/gmj.v55i4.10