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Environmental Health Insights 2024Contamination of maize adversely affects maize quality, yield, and export creating a gap in the attainment of food security, which is a millenium development goal in...
Contamination of maize adversely affects maize quality, yield, and export creating a gap in the attainment of food security, which is a millenium development goal in Nigeria. The study determined fungal abundance, genetic variability, and prevalence of toxigenic fungi in maize grains consumed in North Central, Nigeria. Sixty composite stored maize samples were collected and fungi were isolated and identified after which a multiplex polymerase chain reaction was used to confirm the presence of mycotoxin regulatory genes in suspected toxigenic fungi. The genetic relationship among the toxigenic fungi was determined and the genetic correlation between isolates was established through Restriction fragment length polymorphism (RFLP) analysis. About 389 (64.83%) of the total maize samples collected had fungal species belonging to the genera , and associated with them. Among the regions surveyed, Kogi State exhibited the highest maize contamination rate at 89 samples, accounting for 22.9% of the total samples collected. In Benue and Kogi, the genus exhibited the highest relative abundance, with percentages of 76.6% and 76.3%, respectively. Among its species, and were the most predominant. Kwara State had the highest fungal diversity with a value of 1.711 ( < .05). Benue State had 11 isolates (4.6%) with genes encoding for mycotoxin production, the highest recorded. Conversely, Nasarawa and Niger States each had the lowest count, with 4 isolates possessing such genes. Out of the 238 fungi suspected to be mycotoxigenic that were isolated, 39 have genes that encode for mycotoxin synthesis. Low divergence existed between toxigenic fungal species using the alpha diversity index. This study confirmed that the grains were contaminated with closely related fungal strains, and concluded that maize grains consumed in North Central Nigeria showed high association with fungal microbiota, including species capable of contaminating the grains with mycotoxins.
PubMed: 38721401
DOI: 10.1177/11786302241249858 -
Toxicon : Official Journal of the... May 2024Aspergillus flavus(A. flavus), a common humic fungus known for its ability to infect agricultural products, served as the subject of investigation in this study. The...
Aspergillus flavus(A. flavus), a common humic fungus known for its ability to infect agricultural products, served as the subject of investigation in this study. The primary objective was to assess the antifungal efficacy and underlying mechanisms of binary combinations of five volatile organic compounds (VOCs) produced by lactic acid bacteria, specifically in their inhibition of A. flavus. This assessment was conducted through a comprehensive analysis, involving biochemical characterization and transcriptomic scrutiny. The results showed that VOCs induce notable morphological abnormalities in A. flavus conidia and hyphae. Furthermore, they disrupt the integrity of the fungal cell membrane and cell wall, resulting in the leakage of intracellular contents and an increase in extracellular electrical conductivity. In terms of cellular components, VOC exposure led to an elevation in malondialdehyde content while concurrently inhibiting the levels of total lipids, ergosterol, soluble proteins, and reducing sugars. Additionally, the impact of VOCs on A. flavus energy metabolism was evident, with significant inhibition observed in the activities of key enzymes, such as Na/K-ATPase, malate dehydrogenase, succinate dehydrogenase, and chitinase. And they were able to inhibit aflatoxin B synthesis. The transcriptomic analysis offered further insights, highlighting that differentially expressed genes (DEGs) were predominantly associated with membrane functionality and enriched in pathways about carbohydrate and amino acid metabolism. Notably, DEGs linked to cellular components and energy-related mechanisms exhibited down-regulation, thereby corroborating the findings from the biochemical analyses. In summary, these results elucidate the principal antifungal mechanisms of VOCs, which encompass the disruption of cell membrane integrity and interference with carbohydrate and amino acid metabolism in A. flavus.
Topics: Volatile Organic Compounds; Aspergillus flavus; Antifungal Agents; Lactobacillales
PubMed: 38710308
DOI: 10.1016/j.toxicon.2024.107749 -
Plant Physiology and Biochemistry : PPB Jun 2024In this study, we have investigated the effect of carbon quantum dots (FM-CQDs) synthesized from marine fungal extract on Curcuma longa to improve the plant growth and...
In this study, we have investigated the effect of carbon quantum dots (FM-CQDs) synthesized from marine fungal extract on Curcuma longa to improve the plant growth and curcumin production. The isolated fungus, Aspergillus flavus has produced a high amount of indole-3-acetic acid (IAA) (0.025 mg g), when treated with tryptophan. CQDs were synthesized from the A. flavus extract and it was characterized using ultraviolet visible spectrophotometer (UV-Vis) and high-resolution transmission electron microscopy (HR-TEM). The synthesized CQDs were excited at 365 nm in an UV-Vis and the HR-TEM analysis showed approximately 7.4 nm in size with a spherical shape. Both fungal crude extract (FCE) at 0-100 mg L and FM-CQDs 0-5 mg L concentrations were tested on C. longa. About 80 mg L concentration FCE treated plants has shown a maximum height of 21 cm and FM-CQDs at 4 mg L exhibited a maximum height of 25 cm compared to control. The FM-CQDs significantly increased the photosynthetic pigments such as total chlorophyll (1.08 mg g FW) and carotenoids (17.32 mg g FW) in C. longa. Further, antioxidant enzyme analysis confirmed that the optimum concentrations of both extracts did not have any toxic effects on the plants. FM-CQDs treated plants increased the curcumin content up to 0.060 mg g by HPLC analysis. Semi quantitative analysis revealed that FCE and FM-CQDs significantly upregulated ClCURS1 gene expression in curcumin production.
Topics: Quantum Dots; Curcuma; Carbon; Curcumin; Aspergillus flavus; Indoleacetic Acids; Endophytes
PubMed: 38710114
DOI: 10.1016/j.plaphy.2024.108644 -
Journal of Visualized Experiments : JoVE Apr 2024Aflatoxins are highly carcinogenic secondary metabolites of some fungal species, particularly Aspergillus flavus. Aflatoxins often contaminate economically important...
Aflatoxins are highly carcinogenic secondary metabolites of some fungal species, particularly Aspergillus flavus. Aflatoxins often contaminate economically important agricultural commodities, including peanuts, posing a high risk to human and animal health. Due to the narrow genetic base, peanut cultivars demonstrate limited resistance to fungal pathogens. Therefore, numerous wild peanut species with tolerance to Aspergillus have received substantial consideration by scientists as sources of disease resistance. Exploring plant germplasm for resistance to aflatoxins is difficult since aflatoxin accumulation does not follow a normal distribution, which dictates the need for the analyses of thousands of single peanut seeds. Sufficiently hydrated peanut (Arachis spp.) seeds, when infected by Aspergillus species, are capable of producing biologically active stilbenes (stilbenoids) that are considered defensive phytoalexins. Peanut stilbenes inhibit fungal development and aflatoxin production. Therefore, it is crucial to analyze the same seeds for peanut stilbenoids to explain the nature of seed resistance/susceptibility to the Aspergillus invasion. None of the published methods offer single-seed analyses for aflatoxins and/or stilbene phytoalexins. We attempted to fulfill the demand for such a method that is environment-friendly, uses inexpensive consumables, and is sensitive and selective. In addition, the method is non-destructive since it uses only half of the seed and leaves the other half containing the embryonic axis intact. Such a technique allows germination and growth of the peanut plant to full maturity from the same seed used for the aflatoxin and stilbenoid analysis. The integrated part of this method, the manual challenging of the seeds with Aspergillus, is a limiting step that requires more time and labor compared to other steps in the method. The method has been used for the exploration of wild Arachis germplasm to identify species resistant to Aspergillus and to determine and characterize novel sources of genetic resistance to this fungal pathogen.
Topics: Arachis; Seeds; Aflatoxins; Phytoalexins; Stilbenes; Sesquiterpenes; Chromatography, High Pressure Liquid
PubMed: 38709040
DOI: 10.3791/66574 -
Microscopy Research and Technique May 2024Traditional medicinal plants play an important role in primary health care worldwide. The phytochemical screening and activities of Geranium pusillum were investigated...
Traditional medicinal plants play an important role in primary health care worldwide. The phytochemical screening and activities of Geranium pusillum were investigated in this research. The dried plant leaves were extracted with ethanol, n-hexane, chloroform, dichloromethane, methanol, acetone, and aqueous solvents. These extracts were qualitatively analyzed, GC-MS, antimicrobial activities by using the disc diffusion method, antioxidant activity was determined by 2,2-diphenyl-1-picryl-hydrazyl-hydrate (DPPH) radical scavenging, and cytotoxic activity was analyzed by the hemolytic activity of human red blood cells. The results showed phytochemicals such as flavonoids, terpenoids, steroids, phenols, saponins, tannins, and cardiac glycosides were detected in plant leaves. The ethanol extract at a concentration of 10 mg/mL showed a maximum inhibition zone 17.5 ± 0.09, 15.6 ± 0.11, 14.2 ± 0.17, 18.4 ± 0.11, 16.6 ± 0.15, 12.5 ± 0.13, 15.9 ± 0.10, and 13.1 ± 0.11 mm, and at 15 mg/mL showed 24.5 ± 0.09, 27.2 ± 0.12, 26.3 ± 0.17, 28.4 ± 0.10, 27.9 ± 0.16, 22.5 ± 0.13, 27.1 ± 0.10, and 24.1 ± 0.16 mm against Escherichia coli, Pasturella multocida (gram-negative), Staphylococcus aureus, Bacillus subtilus (gram-positive), Rhizopus solani, Aspergillus flavus, Aspergillus niger, and Alternaria alternate (fungal strain), respectively, and dichloromethane showed a minimum inhibition zone as compared to other extracts against bacterial as well as fungal strains. Chloroform extract had maximum antioxidant activity (45.00 ± 0.08%) and minimum in dichloromethane (12.20 ± 0.04%). Cytotoxic activity was found maximum in acetone extract (19.83 ± 0.07%) and minimum in ethanol extract (4.72 ± 0.04%). It is concluded that phytochemicals like phenols, flavonoids, and others may be responsible for these activities, which is why this plant is used for traditional medicine. RESEARCH HIGHLIGHTS: Geranium pusillum has therapeutic properties that exhibit various biological activities beneficial for human health. G. pusillum has significant inhibitory effects against bacterial and fungal strains. Chloroform solvent extract indicates potential free radical scavenging abilities. Acetone extract exhibits notable effects on human red blood cells and demonstrates significant cytotoxic activity.
PubMed: 38706433
DOI: 10.1002/jemt.24579 -
Environmental Monitoring and Assessment May 2024Edible oils are imported and produced in Ethiopia, notably in Gondar, and their production has expanded considerably in recent years. The expansion of locally produced...
Edible oils are imported and produced in Ethiopia, notably in Gondar, and their production has expanded considerably in recent years. The expansion of locally produced edible vegetable oils with severe quality control, substandard edible oil production, and quality deterioration may contribute to the contamination of microbes, which may cause public health problems. This study determines the microbiological quality of edible vegetable oils being produced and marketed in Gondar City, Northwest Ethiopia, in 2021. A laboratory-based cross-sectional study design was conducted from May to July 2021 in Gondar City. A simple random sampling technique was used to collect 17 edible vegetable oil samples. Aseptically collected samples were analyzed in the microbiology lab room. The microbiological quality of vegetable oil was assessed using standard microbiological procedures and techniques. The collected data were entered into a Microsoft Excel 2016 spreadsheet and Stata Version 14. A non-parametric Kruskal-Wallis test was used to assess significant variation. Seventeen edible vegetable oil samples were examined and found to contain a varying number of bacteria, yeast, and molds. Staphylococcus aureus, Klebsiella Pneumoniae, and Pseudomonas aeruginosa were the identified bacteria, whereas Saccharomyces cerevisiae, Aspergillus niger, Aspergillus flavus, and Aspergillus fumigatus were the identified fungi. Total coliform and fecal coliform isolates were also identified in the oil samples. A level of microbial contamination that has public health importance was observed in some of the oil samples analyzed, and the isolated microorganisms indicate unhygienic handling, processing, and storage practices in the oil production and market sites. The introduction of strict rules, regulations, and updated manufacturing technologies and processes to ensure food safety and quality is needed.
Topics: Ethiopia; Plant Oils; Bacteria; Fungi; Food Microbiology; Cross-Sectional Studies; Food Contamination; Cities
PubMed: 38703327
DOI: 10.1007/s10661-024-12641-y -
Polish Journal of Microbiology Jun 2024This study aimed to investigate azole resistance mechanisms in which involve 51A and 51B genes. Real-time Reverse Transcriptase qPCR method was applied to determine the...
This study aimed to investigate azole resistance mechanisms in which involve 51A and 51B genes. Real-time Reverse Transcriptase qPCR method was applied to determine the overexpression of 51A and 51B genes for 34 isolates. PCR sequencing of these two genes was used to detect the presence of gene mutations. Susceptibility test found sensitivity to voriconazole (VOR) in all strains. 14.7% and 8.8% of isolates were resistant to itraconazole (IT) and posaconazole (POS), respectively, with a cross-resistance in 5.8%. For the double resistant isolates (IT/POS), the expression of 51A was up to 17-fold higher. PCR sequencing showed the presence of 2 mutations in 51A: a synonymous point mutation (P61P) in eight isolates, which did not affect the structure of CYP51A protein, and another non synonymous mutation (G206L) for only the TN-33 strain (cross IT/POS resistance) causing an amino acid change in the protein sequence. However, we noted in 51B the presence of the only non-synonymous mutation (L177G) causing a change in amino acids in the protein sequence for the TN-31 strain, which exhibits IT/POS cross-resistance. A short single intron of 67 bp was identified in the 51A gene, whereas three short introns of 54, 53, and 160 bp were identified in the 51B gene. According to the models provided by PatchDock software, the presence of non-synonymous mutations did not affect the interaction of CYP51A and CYP51B proteins with antifungals. In our study, the overexpression of the 51A and 51B genes is the primary mechanism responsible for resistance in collection. Nevertheless, other resistance mechanisms can be involved.
Topics: Aspergillus flavus; Fungal Proteins; Cytochrome P-450 Enzyme System; Drug Resistance, Fungal; Antifungal Agents; Azoles; Microbial Sensitivity Tests; Humans; Aspergillosis; Mutation; Voriconazole; Triazoles
PubMed: 38700908
DOI: 10.33073/pjm-2024-001 -
Plant Methods May 2024Artemisia campestris L. (AC) leaves are widely recognized for their importance in traditional medicine. Despite the considerable amount of research conducted on this...
BACKGROUND
Artemisia campestris L. (AC) leaves are widely recognized for their importance in traditional medicine. Despite the considerable amount of research conducted on this plant overworld, the chemical composition and the biological activity of the leaves grown in Tunisia remains poorly investigated. In this study of AC, a successive extraction method was employed (hexane, ethyl acetate and methanol) to investigate its bioactive constituents by LC-MS analysis, and their antioxidant, antibacterial, antifungal, and anticancer activities.
RESULTS
Data analysis revealed diverse compound profiles in AC extracts. Methanolic and ethyl acetate extracts exhibited higher polyphenolic content and antioxidant activities, while Hexane showed superior phytosterol extraction. Ethyl acetate extract displayed potent antibacterial activity against multi-resistant Staphylococcus aureus and Pseudomonas aeruginosa. Additionally, all extracts demonstrated, for the first time, robust antifungal efficacy against Aspergillus flavus and Aspergillus niger. Cytotoxicity assays revealed the significant impact of methanolic and ethyl acetate extracts on metastatic breast cancer and multiple myeloma, examined for the first time in our study. Moreover, further analysis on multiple myeloma cells highlighted that the ethyl acetate extract induced apoptotic and necrotic cell death and resulted in an S phase cell cycle blockage, underscoring its therapeutic potential.
CONCLUSIONS
This investigation uncovers novel findings in Tunisian AC, notably the identification of lupeol, oleanolic acid, ursolic acid, stigmasterol and β-sitosterol. The study sheds light on the promising role of AC extracts in therapeutic interventions and underscores the need for continued research to harness its full potential in medicine and pharmaceutical development.
PubMed: 38698384
DOI: 10.1186/s13007-024-01185-4 -
BMC Plant Biology May 2024Aspergillus flavus is an important agricultural and food safety threat due to its production of carcinogenic aflatoxins. It has high level of genetic diversity that is...
BACKGROUND
Aspergillus flavus is an important agricultural and food safety threat due to its production of carcinogenic aflatoxins. It has high level of genetic diversity that is adapted to various environments. Recently, we reported two reference genomes of A. flavus isolates, AF13 (MAT1-2 and highly aflatoxigenic isolate) and NRRL3357 (MAT1-1 and moderate aflatoxin producer). Where, an insertion of 310 kb in AF13 included an aflatoxin producing gene bZIP transcription factor, named atfC. Observations of significant genomic variants between these isolates of contrasting phenotypes prompted an investigation into variation among other agricultural isolates of A. flavus with the goal of discovering novel genes potentially associated with aflatoxin production regulation. Present study was designed with three main objectives: (1) collection of large number of A. flavus isolates from diverse sources including maize plants and field soils; (2) whole genome sequencing of collected isolates and development of a pangenome; and (3) pangenome-wide association study (Pan-GWAS) to identify novel secondary metabolite cluster genes.
RESULTS
Pangenome analysis of 346 A. flavus isolates identified a total of 17,855 unique orthologous gene clusters, with mere 41% (7,315) core genes and 59% (10,540) accessory genes indicating accumulation of high genomic diversity during domestication. 5,994 orthologous gene clusters in accessory genome not annotated in either the A. flavus AF13 or NRRL3357 reference genomes. Pan-genome wide association analysis of the genomic variations identified 391 significant associated pan-genes associated with aflatoxin production. Interestingly, most of the significantly associated pan-genes (94%; 369 associations) belonged to accessory genome indicating that genome expansion has resulted in the incorporation of new genes associated with aflatoxin and other secondary metabolites.
CONCLUSION
In summary, this study provides complete pangenome framework for the species of Aspergillus flavus along with associated genes for pathogen survival and aflatoxin production. The large accessory genome indicated large genome diversity in the species A. flavus, however AflaPan is a closed pangenome represents optimum diversity of species A. flavus. Most importantly, the newly identified aflatoxin producing gene clusters will be a new source for seeking aflatoxin mitigation strategies and needs new attention in research.
Topics: Aspergillus flavus; Aflatoxins; Multigene Family; Genome, Fungal; Secondary Metabolism; Zea mays; Genome-Wide Association Study; Genes, Fungal; Whole Genome Sequencing; Genetic Variation
PubMed: 38693487
DOI: 10.1186/s12870-024-04950-8 -
Journal of Agricultural and Food... May 2024contamination in agriculture and food industries poses threats to human health, leading to a requirement of a safe and effective method to control fungal contamination....
contamination in agriculture and food industries poses threats to human health, leading to a requirement of a safe and effective method to control fungal contamination. Chitosan-based nitrogen-containing derivatives have attracted much attention due to their safety and enhanced antimicrobial applications. Herein, a new benzimidazole-grafted chitosan (BAC) was synthesized by linking the chitosan (CS) with a simple benzimidazole compound, 2-benzimidazolepropionic acid (BA). The characterization of BAC was confirmed by Fourier transform infrared (FTIR) spectroscopy and nuclear magnetic resonance spectroscopy (H and C NMR). Then, the efficiency of BAC against ACCC 32656 was investigated in terms of spore germination, mycelial growth, and aflatoxin production. BAC showed a much better antifungal effect than CS and BA. The minimum inhibitory concentration (MIC) value was 1.25 mg/mL for BAC, while the highest solubility of CS (16.0 mg/mL) or BA (4.0 mg/mL) could not completely inhibit the growth of . Furthermore, results showed that BAC inhibited spore germination and elongation by affecting ergosterol biosynthesis and the cell membrane integrity, leading to the permeabilization of the plasma membrane and leakage of intracellular content. The production of aflatoxin was also inhibited when treated with BAC. These findings indicate that benzimidazole-derived natural CS has the potential to be used as an ideal antifungal agent for food preservation.
Topics: Aspergillus flavus; Benzimidazoles; Chitosan; Fungicides, Industrial; Microbial Sensitivity Tests; Aflatoxins; Antifungal Agents; Spores, Fungal
PubMed: 38687832
DOI: 10.1021/acs.jafc.4c01010