Genetic Profiling of Aspergillus Isolates with Varying Aflatoxin Production Potential from Different Maize-Growing Regions of Kenya

Oloo, Richard Dooso; Okoth, Sheila; Wachira, P. M.; Mutiga, Samuel; Ochieng, Phillis Emelda; Kago, Leah; Ngángá, Fredrick; Entfellner, Jean-Baka Domelevo; Ghimire, Sita R.

doi:10.3390/toxins11080467

Cited by 19 publications

(13 citation statements)

References 50 publications

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“…The aflR and aflD peaked at 6 and 9 dpi, respectively. AflD is an early gene encoding a reductase responsible for the conversion of norsolorinic acid to averantin [45][46][47]. The temporal shift of three days observed in this study analysing aflR and aflD transcriptional profiles could be due to the role of aflR that, being a transcription activator of the aflatoxin biosynthetic pathway, was earlier induced, and showed a higher magnitude of activation in comparison to aflD.…”

Section: Discussionmentioning

confidence: 61%

Fusarium verticillioides and Aspergillus flavus Co-Occurrence Influences Plant and Fungal Transcriptional Profiles in Maize Kernels and In Vitro

Lanubile

Giorni

Bertuzzi

et al. 2021

Toxins

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Climate change will increase the co-occurrence of Fusarium verticillioides and Aspergillus flavus, along with their mycotoxins, in European maize. In this study, the expression profiles of two pathogenesis-related (PR) genes and four mycotoxin biosynthetic genes, FUM1 and FUM13, fumonisin pathway, and aflR and aflD, aflatoxin pathway, as well as mycotoxin production, were examined in kernels and in artificial medium after a single inoculation with F. verticillioides or A. flavus or with the two fungi in combination. Different temperature regimes (20, 25 and 30 °C) over a time-course of 21 days were also considered. In maize kernels, PR genes showed the strongest induction at 25 °C in the earlier days post inoculation (dpi)with both fungi inoculated singularly. A similar behaviour was maintained with fungi co-occurrence, but with enhanced defence response at 9 dpi under 20 °C. Regarding FUM genes, in the kernels inoculated with F. verticillioides the maximal transcript levels occurred at 6 dpi at 25 °C. At this temperature regime, expression values decreased with the co-occurrence of A. flavus, where the highest gene induction was detected at 20 °C. Similar results were observed in fungi grown in vitro, whilst A. flavus presence determined lower levels of expression along the entire time-course. As concerns afl genes, considering both A. flavus alone and in combination, the most elevated transcript accumulation occurred at 30 °C during all time-course both in infected kernels and in fungi grown in vitro. Regarding mycotoxin production, no significant differences were found among temperatures for kernel contamination, whereas in vitro the highest production was registered at 25 °C for aflatoxin B1 and at 20 °C for fumonisins in the case of single inoculation. In fungal co-occurrence, both mycotoxins resulted reduced at all the temperatures considered compared to the amount produced with single inoculation.

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Section: Discussionmentioning

confidence: 61%

Fusarium verticillioides and Aspergillus flavus Co-Occurrence Influences Plant and Fungal Transcriptional Profiles in Maize Kernels and In Vitro

Lanubile

Giorni

Bertuzzi

et al. 2021

Toxins

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“…Aspergillus was the most common fungi in the gut of organisms Aspergillus minisclerotigenes produced mycotoxin, , which exerted neurotoxic effects on brain tissues . Recent evidence demonstrated that inhalation of Aspergillus variegatus could induce neuroinflammation, destroyed neuroimmune homeostasis, and led to cognitive and emotional defects in children and adults.…”

Section: Discussionmentioning

confidence: 99%

Effect of Probiotic Fungi against Cognitive Impairment in Mice via Regulation of the Fungal Microbiota–Gut–Brain Axis

Yuan

Kong

et al. 2022

J. Agric. Food Chem.

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The fungal microbiota may be involved in the regulation of cognition and behavior, while the role of probiotic fungi against cognitive impairment is unclear. Here, we explored the idea that probiotic Saccharomyces boulardii could participate in the regulation of microglia-induced neuroinflammation in Alzheimer's disease (AD) model mice. Cognitive deficits, deposits of amyloidβ (Aβ) and phosphorylation of tau, synaptic plasticity, microglia activation, and neuroinflammatory reactions were observed. The expression levels of Toll-like receptors (TLRs) pathway-related proteins were detected. Meanwhile, intestinal barrier integrity and fungal microbiota composition were evaluated. Our results showed fungal microbiota dysbiosis in APP/PS1 mice, which might result in the neuroinflammation of AD. The increased levels of interleukin (IL)-6, IL-1β, and cluster of differentiation 11b (CD11b) were observed in APP/PS1 mice, which were associated with activation of microglia, indicative of a broader recognition of neuroinflammation mediated by fungal microbiota compared to hitherto appreciated. Probiotic S. boulardii treatment improved dysbiosis, alleviated the neuroinflammation as well as synaptic injury, and ultimately improved cognitive impairment. Moreover, S. boulardii therapy could inhibit microglia activation and the TLRs pathway, which were reversed by antifungal treatment. These findings revealed that S. boulardii actively participated in regulating the TLRs pathway to inhibit the neuroinflammation via the gut− brain axis.

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“…Phylogenetically, during studies of endophytic fungi as sources of bioactive metabolites, molecular identification is typically performed using the ITS sequences or GenBank BLAST search ( Raja et al, 2017 ; Zhang X. G. et al, 2020 ). However, the two approaches have distinct limitations, because they may not be able to distinguish some members with close phylogenetic relationships of certain genera ( Oloo et al, 2019 ), and more than 1/4 GenBank fungal ITS sequences were submitted without sufficient taxonomic confirmation ( Raja et al, 2017 ). Therefore, in this study, molecular identification was carried out using protein-coding and ribosomal genes, mainly including LSU, ITS, and TUB.…”

Section: Discussionmentioning

confidence: 99%

Multigene Phylogeny, Diversity and Antimicrobial Potential of Endophytic Sordariomycetes From Rosa roxburghii

Zhang

Wei

et al. 2021

Front. Microbiol.

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Rosa roxburghii Tratt. is widely applied in food, cosmetics, and traditional medicine, and has been demonstrated to possess diverse bioactivities. Plant endophytic fungi are important microbial resources with great potential for application in many fields. They not only establish mutualistic symbiosis with host plants but also produce a variety of bioactive compounds. Therefore, in the present study, endophytic fungi were isolated from R. roxburghii, the diversity and antimicrobial activities were evaluated. As a result, 242 strains of endophytic Sordariomycetes were successfully isolated. Multigene phylogenetic analyses showed that these isolates included eight orders, 19 families, 33 genera. The dominant genera were Diaporthe (31.4%), Fusarium (14.4%), Chaetomium (7.9%), Dactylonectria (7.0%), Graphium (4.5%), Colletotrichum (4.1%), and Clonostachys (4.1%). For different tissues of R. roxburghii, alpha diversity analysis revealed that the diversity of fungal communities decreased in the order of root, fruit, stem, flower, leaf, and seed, and Clonostachys and Dactylonectria exhibited obvious tissue specificity. Meanwhile, functional annotation of 33 genera indicated that some fungi have multitrophic lifestyles combining endophytic, pathogenic, and saprophytic behavior. Additionally, antimicrobial activities of endophytic Sordariomycetes against Lasiodiplodia theobromae, Botryosphaeria dothidea, Colletotrichum capsici, Pyricularia oryzae, Rhizoctonia solani, Fusarium oxysporum, Pseudomonas syringae, Pantoea agglomerans, Staphylococcus aureus, Bacillus subtilis, Escherichia coli, and Pseudomonas aeruginosa were screened. Dual culture test assays showed that there were 40 different endophytic species with strong inhibition of at least one or moderate inhibition of two or more against the 12 tested strains. The results from the filter paper diffusion method suggested that extracellular metabolites may be more advantageous than intracellular metabolites in the development of antimicrobial agents. Eleven isolates with good activities were screened. In particular, Hypomontagnella monticulosa HGUP194009 and Nigrospora sphaerica HGUP191020 have shown promise in both broad-spectrum and intensity. Finally, some fungi that commonly cause disease have been observed to have beneficial biological activities as endophytic fungi. In conclusion, this study showed the species composition, alpha diversity, and lifestyle diversity of endophytic Sordariomycetes from R. roxburghii and demonstrated these isolates are potential sources for exploring antimicrobial agents.

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Genetic Profiling of Aspergillus Isolates with Varying Aflatoxin Production Potential from Different Maize-Growing Regions of Kenya

Cited by 19 publications

References 50 publications

Fusarium verticillioides and Aspergillus flavus Co-Occurrence Influences Plant and Fungal Transcriptional Profiles in Maize Kernels and In Vitro

Fusarium verticillioides and Aspergillus flavus Co-Occurrence Influences Plant and Fungal Transcriptional Profiles in Maize Kernels and In Vitro

Effect of Probiotic Fungi against Cognitive Impairment in Mice via Regulation of the Fungal Microbiota–Gut–Brain Axis

Multigene Phylogeny, Diversity and Antimicrobial Potential of Endophytic Sordariomycetes From Rosa roxburghii

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