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BMC Microbiology Aug 2021Aspergillus species cause aflatoxin contamination in groundnut kernels, being a health threat in agricultural products and leading to commodity rejection by domestic and...
BACKGROUND
Aspergillus species cause aflatoxin contamination in groundnut kernels, being a health threat in agricultural products and leading to commodity rejection by domestic and international markets. Presence of Aspergillus flavus and A. parasiticus colonizing groundnut in eastern Ethiopia, as well as presence of aflatoxins have been reported, though in this region, no genetic studies have been done of these species in relation to their aflatoxin production.
RESULTS
In this study, 145 Aspergillus isolates obtained from groundnut kernels in eastern Ethiopia were genetically fingerprinted using 23 Insertion/Deletion (InDel) markers within the aflatoxin-biosynthesis gene cluster (ABC), identifying 133 ABC genotypes. Eighty-four isolates were analyzed by Ultra-Performance Liquid Chromatography (UPLC) for in vitro aflatoxin production. Analysis of genetic distances based on the approximately 85 kb-ABC by Neighbor Joining (NJ), 3D-Principal Coordinate Analysis (3D-PCoA), and Structure software, clustered the isolates into three main groups as a gradient in their aflatoxin production. Group I, contained 98% A. flavus, including L- and non-producers of sclerotia (NPS), producers of B and B aflatoxins, and most of them collected from the lowland-dry Babile area. Group II was a genetic admixture population of A. flavus (NPS) and A. flavus S morphotype, both low producers of aflatoxins. Group III was primarily represented by A. parasiticus and A. flavus S morphotype isolates both producers of B, B and G, G aflatoxins, and originated from the regions of Darolabu and Gursum. The highest in vitro producer of aflatoxin B was A. flavus NPS N1436 (77.98 μg/mL), and the highest producer of aflatoxin G was A. parasiticus N1348 (50.33 μg/mL), these isolates were from Gursum and Darolabu, respectively.
CONCLUSIONS
To the best of our knowledge, this is the first study that combined the use of InDel fingerprinting of the ABC and corresponding aflatoxin production capability to describe the genetic diversity of Aspergillus isolates from groundnut in eastern Ethiopia. Three InDel markers, AFLC04, AFLC08 and AFLC19, accounted for the main assignment of individuals to the three Groups; their loci corresponded to aflC (pksA), hypC, and aflW (moxY) genes, respectively. Despite InDels within the ABC being often associated to loss of aflatoxin production, the vast InDel polymorphism observed in the Aspergillus isolates did not completely impaired their aflatoxin production in vitro.
Topics: Aflatoxins; Agriculture; Arachis; Aspergillus flavus; DNA Fingerprinting; Ethiopia; Food Contamination; Multigene Family
PubMed: 34454439
DOI: 10.1186/s12866-021-02290-3 -
Toxins Sep 2022Aflatoxin B1 (AFB1), a common contaminant in food and feed during storage, does great harm to human and animal health. Five essential oils (thymol, carvacrol,...
Aflatoxin B1 (AFB1), a common contaminant in food and feed during storage, does great harm to human and animal health. Five essential oils (thymol, carvacrol, cinnamaldehyde, eugenol, and citral) were tested for their inhibition effect against Aspergillus flavus (A. flavus) in broth and feed. Cinnamaldehyde and citral were proven to be most effective against A. flavus compared to others and have a synergistic effect when used simultaneously. The broth supplemented with cinnamaldehyde and citral was inoculated with A. flavus (106 CFU/mL) by using the checkerboard method, and mold counts and AFB1 production were tested on days 0, 1, 3, and 5. Similarly, 100 g poultry feed supplemented with the mixture of cinnamaldehyde and citral at the ratio 1:1 was also inoculated with A. flavus, and the same parameters were tested on days 0, 7, 14, and 21. In poultry feed, cinnamaldehyde and citral significantly reduced mold counts and AFB1 concentrations (p < 0.05). Results showed that cinnamaldehyde and citral have a positive synergy effect and could both inhibit at least 90% the fungal growth and aflatoxin B1 production at 40 μg/mL in broth and poultry feed, and could be an alternative to control aflatoxin contamination in food and feed in future.
Topics: Animals; Humans; Aspergillus flavus; Aflatoxin B1; Oils, Volatile; Eugenol; Thymol; Poultry; Aflatoxins
PubMed: 36287924
DOI: 10.3390/toxins14100655 -
Toxins Nov 2021poses a threat to society economy and public health due to aflatoxin production. is a gene located in the aflatoxin gene cluster, but the function of AflN is undefined...
poses a threat to society economy and public health due to aflatoxin production. is a gene located in the aflatoxin gene cluster, but the function of AflN is undefined in . In this study, is knocked out and overexpressed to study the function of AflN. The results indicated that the loss of AflN leads to the defect of aflatoxin biosynthesis. AflN is also found to play a role in conidiation but not hyphal growth and sclerotia development. Moreover, AlfN is related to the response to environmental oxidative stress and intracellular levels of reactive oxygen species. At last, AflN is involved in the pathogenicity of to host. These results suggested that AflN played important roles in aflatoxin biosynthesis, conidiation and reactive oxygen species generation in , which will be helpful for the understanding of function, and will be beneficial to the prevention and control of and aflatoxins contamination.
Topics: Aflatoxins; Aspergillus flavus; Fungal Proteins; Gene Expression Regulation, Fungal; Multigene Family; Oxidative Stress; Reactive Oxygen Species
PubMed: 34822615
DOI: 10.3390/toxins13110831 -
Toxins Apr 2023Recently, aflatoxin exposure especially through maize and groundnuts has been associated with growth impairment in children. Infants and children are considered to be...
Recently, aflatoxin exposure especially through maize and groundnuts has been associated with growth impairment in children. Infants and children are considered to be more susceptible to toxins because of their lower body weight, higher metabolic rate, and lower ability to detoxify. On the other hand, for women of reproductive age, aflatoxin exposure may not only affect their health but also that of their foetus in the case of pregnancy. This study focused on investigating AFB contamination in maize and groundnut from respondent households, exposure among women of reproductive age and associations of aflatoxin contamination with growth retardation among children in Mtwara region, Tanzania. The highest maximum AFB contamination levels from all samples obtained were in maize grain (2351.5 μg/kg). From a total of 217 maize samples collected, aflatoxins were above European Union (EU) and East African Community (EAC) tolerable limits in 76.0% and 64.5% of all samples. Specifically, maize grain had the highest proportion of samples contaminated above tolerable limits (80.3% and 71.1% for EU and EAC limits). Groundnut had 54.0% and 37.9% of samples above EU and EAC maximum tolerable limits. The lowest proportion of contaminated samples on the other hand was for bambara nut (37.5% and 29.2% for EU and EAC limits, respectively). Aflatoxin exposure in our surveyed population was much higher than previous observations made in Tanzania and also higher than those observed in Western countries such as Australia and the USA. Among children, AFB concentration was associated with lower weight for height z scores and weight for age z scores in the univariate model ( < 0.05). In summary, these results indicate the seriousness of aflatoxin contamination in foods commonly consumed in the vulnerable population assessed. Strategies both from the health, trade, and nutrition sectors should therefore be designed and implemented to address aflatoxin and mycotoxin contamination in diets.
Topics: Infant; Pregnancy; Humans; Female; Child; Aflatoxins; Tanzania; Food Contamination; Agriculture; Edible Grain; Fabaceae; Zea mays
PubMed: 37104195
DOI: 10.3390/toxins15040257 -
Toxins Sep 2021Aflatoxins (AFs) are secondary metabolites that represent serious threats to human and animal health. They are mainly produced by strains of the saprophytic fungus ,... (Review)
Review
Aflatoxins (AFs) are secondary metabolites that represent serious threats to human and animal health. They are mainly produced by strains of the saprophytic fungus , which are abundantly distributed across agricultural commodities. AF contamination is receiving increasing attention by researchers, food producers, and policy makers in China, and several interesting review papers have been published, that mainly focused on occurrences of AFs in agricultural commodities in China. The goal of this review is to provide a wider scale and up-to-date overview of AF occurrences in different agricultural products and of the distribution of across different food and feed categories and in Chinese traditional herbal medicines in China, for the period 2000-2020. We also highlight the health impacts of chronic dietary AF exposure, the recent advances in biological AF mitigation strategies in China, and recent Chinese AF standards.
Topics: Aflatoxins; Aspergillus; China; Crops, Agricultural; Drug Contamination; Drugs, Chinese Herbal; Food Contamination; Humans
PubMed: 34678973
DOI: 10.3390/toxins13100678 -
Toxins Nov 2019This study investigated the aflatoxin production potentials of selected fungi using a polyphasic approach. Internally transcribed spacer region of the fungi was...
This study investigated the aflatoxin production potentials of selected fungi using a polyphasic approach. Internally transcribed spacer region of the fungi was amplified using the polymerase chain reaction. Forty-five strains were further assessed for aflatoxin production using the conventional methods such as growth on yeast extract sucrose, β-cyclodextrin neutral red desiccated coconut agar (β-CNRDCA); expression of the aflatoxin regulatory genes and the use of both thin-layer chromatography (TLC) and high-performance liquid chromatography (HPLC). A large proportion (82.22%) of the isolates harbored the -1 gene while 55.56%, 68.89%, and 80% possessed the -1, -A, and R genes, respectively. All 100% the isolates harbored the J gene. Twenty-three isolates were positive for aflatoxin production based on the yeast extract sucrose medium (YES) test; ammonium vapor test (51%), yellow pigment production (75.5%), and β-CNRDCA tests; and blue/green fluorescence (57.7%). Based on TLC detection 42.2% produced aflatoxins while in the HPLC, total aflatoxin (AFTOT) production concentrations ranged from 6.77-71,453 µg/g. Detectable aflatoxin B1 (AFB1) concentrations obtained from the HPLC ranged between 3.76 and 70,288 µg/g; 6.77 and 242.50 µg/g for aflatoxin B2 (AFB2); 1.87 and 745.30 µg/g for aflatoxin G1 (AFG1); and 1.67 and 768.52 µg/g for aflatoxin G2 (AFG2). AFTOT contamination levels were higher than European Union tolerable limits (4 µg/kg). The regression coefficient was one ( = 1) while significant differences exist in the aflatoxin concentrations of ( ≤ 0.05). This study reports the potentials of previously known as a non-aflatoxin producer to produce AFG1, AFG2, AFB1, and AFB2 toxins. species in feedlots of animals reared for food are capable of producing aflatoxins which could pose hazards to health.
Topics: Aflatoxins; Animal Feed; Aspergillus; Aspergillus oryzae; Biosynthetic Pathways; Chromatography, High Pressure Liquid; Culture Media; Genes, Fungal; Polymerase Chain Reaction
PubMed: 31779084
DOI: 10.3390/toxins11120692 -
Frontiers in Public Health 2022Aflatoxin B and ochratoxin A are mycotoxins produced by filamentous fungi that attack crops on field and storage. Both mycotoxins present a risk on public health since...
BACKGROUND
Aflatoxin B and ochratoxin A are mycotoxins produced by filamentous fungi that attack crops on field and storage. Both mycotoxins present a risk on public health since aflatoxin B is a hepatotoxic and hepatocarcinogenic agent while ochratoxin A can be nephrotoxic. Those mycotoxins can be found in several food items including spices, herbs, and nuts.
OBJECTIVES
In Lebanon, few studies address aflatoxin B and ochratoxin A contamination in spices, herbs, and nuts. So, the aim of this study is to investigate the concentrations of those two mycotoxins particularly in spices and herbs and the concentration of aflatoxin B in nuts, and to determine the dietary exposure of the Lebanese population and their possible attribution to liver cancer and renal damage.
METHODS
In this work, a total of 198 samples of spices, herbs, and nuts were collected from different sites. Aflatoxin B and ochratoxin A were quantified using immune-affinity columns. A food frequency questionnaire was used to quantify the consumption of spices, herbs, and nuts in Lebanon. Exposure to aflatoxin B and ochratoxin A was calculated accordingly and liver and kidney cancer risks were evaluated.
RESULTS
Aflatoxin B was respectively found in 100, 20.4, and 98.6% of the spices, herbs, and nuts samples, while ochratoxin A was found in 100 and 44.4% of spices and herbs, respectively. Aflatoxin B was found at mean concentration of 0.97, 0.27, and 0.40 μg/kg in spices, herbs, and nuts, respectively while ochratoxin A was found at mean concentrations of 38.8 and 1.81 μg/kg in spices and herbs, respectively. Aflatoxin B occurrence was shown to be associated in this study with 0.017 additional cancer cases per 100,000 persons per year, and ochratoxin A weekly exposure was shown to be 5.04 ng/kg bw less than the Provisional Tolerable Weekly Intake of 100 ng/kg bw which indicates low risk of renal damage from spices and herbs consumption.
CONCLUSION
The consumption of spices, herbs, and nuts in Lebanon could lead to an increase in health risks associated with aflatoxin B and ochratoxin A, specifically spices. The reported occurrence may be directly related to poor storage conditions.
Topics: Aflatoxin B1; Nuts; Public Health; Lebanon; Food Contamination; Mycotoxins
PubMed: 36699892
DOI: 10.3389/fpubh.2022.1072727 -
Contrast Media & Molecular Imaging 2022With the development of the economy, the food safety problems caused by aflatoxin have become increasingly prominent. With regard to the control of aflatoxin pollution,... (Review)
Review
With the development of the economy, the food safety problems caused by aflatoxin have become increasingly prominent. With regard to the control of aflatoxin pollution, the Chinese government has promulgated a series of legal documents on food safety related to aflatoxin pollution, such as the formulation of industry standards for allowable limits of aflatoxin and various penalties for violators. Although these measures have achieved good results to some extent, there are still many legal problems. This study reviews the current situation of aflatoxin pollution control in food in China. The court judgment documents related to aflatoxin pollution from January 1st 2014 to January 1st 2020 are investigated to analyze the accountability status of aflatoxin pollution treatment in China. Furthermore, this study mainly cross verified the above problems by means of the literature survey and an organization interview and proposed solutions on the basis of in-depth analysis of their causes. Finally, some suggestions are put forward to solve the problem of aflatoxin pollution accountability in China.
Topics: Aflatoxins; China; Criminals; Environmental Pollution; Humans; Judgment
PubMed: 36003998
DOI: 10.1155/2022/8212370 -
Volatiles of antagonistic soil yeasts inhibit growth and aflatoxin production of Aspergillus flavus.Microbiological Research Oct 2022Minimizing Aspergillus flavus growth is an effective strategy to mitigate aflatoxin contamination in food and agricultural products. In the present investigation, we...
Minimizing Aspergillus flavus growth is an effective strategy to mitigate aflatoxin contamination in food and agricultural products. In the present investigation, we attempted to utilize soil-associated yeasts from the Western and Eastern Ghats of India against A. flavus to reduce aflatoxin contamination. Forty-five yeast isolates were screened against A. flavus using overlay and dual plate assays. Among them, 12 isolates effectively inhibited the growth of A. flavus. The 18S rDNA gene sequence analysis identified the twelve antagonistic isolates as belonging to Saccharomyces cerevisiae, Suhomyces xylopsoci, Pichia kudriavzevii, and Candida tropicalis. From the isolated yeasts, S. cerevisiae strains were selected for further evaluation based on the potential antagonistic activity. Volatiles of S. cerevisiae effectively suppressed the mycelial growth of A. flavus (P < 0.05) up to 92.1 % at 7 DAI. Scanning electron microscopic images of the fungus exposed to volatiles showed hyphal deformity and mycelial damage. Aflatoxin B (AFB) production was drastically reduced up to 99.0 % in the volatile-exposed fungus compared to the control. The yeast strain YKK1 showed consistent Aspergillus flavus growth inhibition (80.7 %) and AFB production (98.1 %) for 14 days. Gas chromatography-mass spectrophotometry analysis of the yeast volatiles revealed the presence of antimicrobial compounds, including 1-pentanol, 1-propanol, ethyl hexanol, ethanol, 2-methyl-1-butanol, ethyl acetate, dimethyl trisulfide, p-xylene, styrene, and 1,4-pentadiene. The evaluated compounds of yeast volatiles, including ethyl acetate, hexanal, 1-propanol, 1-heptanol, 1-butanol, and benzothiazole, inhibited the fungal growth and AFB production of Aspergillus flavus when applied as pure chemicals. Benzothiazole at 5 mM was responsible for a high level of growth inhibition (23.6 %) and reduction of AFB synthesis (93.5 %). Hence, volatile compounds produced by soil yeast strains could be a potential biocontrol mechanism against aflatoxin contamination.
Topics: 1-Butanol; 1-Propanol; Aflatoxin B1; Aflatoxins; Aspergillus flavus; Benzothiazoles; Saccharomyces cerevisiae; Soil
PubMed: 35940109
DOI: 10.1016/j.micres.2022.127150 -
Journal of Food Protection Oct 2021This study was carried out to evaluate the prevalence of mycobiota and aflatoxin (AF) B1 contamination in sesame seeds from rainfed and irrigated zones of the Punjab,...
ABSTRACT
This study was carried out to evaluate the prevalence of mycobiota and aflatoxin (AF) B1 contamination in sesame seeds from rainfed and irrigated zones of the Punjab, Pakistan. For this purpose, 100 sesame seed samples were collected directly from the fields of major sesame-producing areas in rainfed and irrigated zones. The agar plate method was used for isolation of mycobiota, and thin-layer chromatography was used to determine AFB1 concentrations. Seed samples were then stored for 12 months. After 12 months, the seeds were again analyzed for mycobiota and AFB1 for comparison. All samples were positive for fungal growth under fresh and stored conditions. Twenty-one fungal species of 10 genera were isolated. Aspergillus flavus was the most prevalent contaminant found in fresh and stored sesame seeds from rainfed and irrigated zones, followed by Aspergillus niger, Alternaria alternata, and Fusarium oxysporum. The least prevalent fungi were Aspergillus ochraceus and Cladosporium oxysporum. Analysis revealed that 92% of fresh and 99% of stored seed samples were contaminated with AFB1. In the rainfed zone, 88% of fresh and 100% of stored seed samples were contaminated with AFB1, with mean concentrations of 15.74 and 33.8 ppb, respectively. In the irrigated zone, 96% of fresh and 98% of stored seed samples were contaminated with AFB1, with mean concentrations of 20.5 and 27.56 ppb, respectively. AFB1 concentrations >20 ppb were found in 20% of fresh and 100% of stored seeds samples from the rainfed zone and in 28% of fresh and 60% of stored samples from the irrigated zone and thus were not fit for human consumption as per the maximum limit (20 ppb) assigned by the U.S. Food and Drug Administration and the Food and Agriculture Organization of the United Nations. This report is the first on the mycobiota and AFB1 contamination in sesame seeds from rainfed and irrigated zones of the Punjab, Pakistan. These baseline data are an initial step in the effort to deal with this significant food safety issue.
Topics: Aflatoxin B1; Aflatoxins; Alternaria; Cladosporium; Food Contamination; Fusarium; Humans; Pakistan; Seeds; Sesamum
PubMed: 34086928
DOI: 10.4315/JFP-21-060