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Journal of Fungi (Basel, Switzerland) Mar 2021Members of are broadly distributed across subtropical and tropical areas of southwest and southern China. This host provides multiple substrates that can be richly...
Members of are broadly distributed across subtropical and tropical areas of southwest and southern China. This host provides multiple substrates that can be richly colonized by numerous undescribed fungal species. There is a severe lack of microfungal studies on in China, and consequently, the diversity, phylogeny and taxonomy of these microorganisms are all largely unknown. This paper presents two new genera and four new species in three orders of Dothideomycetes gathered from dead twigs of in Honghe, China. All new collections were made within a selected area in Honghe from a single sp. This suggests high fungal diversity in the region and the existence of numerous species awaiting discovery. Multiple gene sequences (non-translated loci and protein-coding regions) were analysed with maximum likelihood and Bayesian analyses. Results from the phylogenetic analyses supported placing gen. et sp. in the Teratosphaeriaceae family. Analysis of sequences resulted in sp. nov., while analysed Lophiostomataceae sequences revealed gen. et sp. nov. Finally, phylogeny based on a combined dataset of pyrenochaeta-like sequences demonstrates strong statistical support for placing sp. nov. in Parapyrenochaetaceae. Morphological and updated phylogenetic circumscriptions of the new discoveries are also discussed.
PubMed: 33802406
DOI: 10.3390/jof7030180 -
PloS One 2018The first draft genome sequencing of the non-model fungal pathogen Pyrenochaeta lycopersici showed an expansion of gene families associated with heterokaryon...
The first draft genome sequencing of the non-model fungal pathogen Pyrenochaeta lycopersici showed an expansion of gene families associated with heterokaryon incompatibility and lacking of mating-type genes, providing insights into the genetic basis of this "imperfect" fungus which lost the ability to produce the sexual stage. However, due to the Illumina short-read technology, the draft genome was too fragmented to allow a comprehensive characterization of the genome, especially of the repetitive sequence fraction. In this work, the sequencing of another P. lycopersici isolate using long-read Single Molecule Real-Time sequencing technology was performed with the aim of obtaining a gapless genome. Indeed, a gapless genome assembly of 62.7 Mb was obtained, with a fraction of repetitive sequences representing 30% of the total bases. The gene content of the two P. lycopersici isolates was very similar, and the large difference in genome size (about 8 Mb) might be attributable to the high fraction of repetitive sequences detected for the new sequenced isolate. The role of repetitive elements, including transposable elements, in modulating virulence effectors is well established in fungal plant pathogens. Moreover, transposable elements are of fundamental importance in creating and re-modelling genes, especially in imperfect fungi. Their abundance in P. lycopersici, together with the large expansion of heterokaryon incompatibility genes in both sequenced isolates, suggest the presence of possible mechanisms alternative to gene re-assorting mediated by sexual recombination. A quite large fraction (~9%) of repetitive elements in P. lycopersici, has no homology with known classes, strengthening this hypothesis. The availability of a gapless genome of P. lycopersici allowed the in-depth analysis of its genome content, by annotating functional genes and TEs. This goal will be an important resource for shedding light on the evolution of the reproductive and pathogenic behaviour of this soilborne pathogen and the onset of a possible speciation within this species.
Topics: Ascomycota; Chromosome Mapping; Computer Systems; DNA Transposable Elements; DNA, Fungal; Genome, Fungal; Molecular Sequence Annotation; Phylogeny; Sequence Analysis, DNA
PubMed: 29979772
DOI: 10.1371/journal.pone.0200217 -
Frontiers in Microbiology 2016Opportunistic subcutaneous fungal infections are increasing nowadays due to the growing number of medical conditions causing immunosuppression, especially organ...
Opportunistic subcutaneous fungal infections are increasing nowadays due to the growing number of medical conditions causing immunosuppression, especially organ transplant. The incidence rate of subcutaneous phaeohyphomycosis is very low. Most studies found are case reports. They showed a wide variation of clinical presentations. Pyrenochaeta romeroi, a fungus from the Dematiaceae group is a saprophyte found in soil and plants and a possible causative agent of phaeohyphomycosis. We present a rare case of subcutaneous phaeohyphomycosis caused by P. romeroi mimicking a synovial cyst in a diabetic patient.
PubMed: 27630637
DOI: 10.3389/fmicb.2016.01405 -
Marine Drugs Jan 2024Co-cultivation, coupled with the OSMAC approach, is considered an efficient method for expanding microbial chemical diversity through the activation of cryptic...
Co-cultivation, coupled with the OSMAC approach, is considered an efficient method for expanding microbial chemical diversity through the activation of cryptic biosynthetic gene clusters (BGCs). As part of our project aiming to discover new fungal metabolites for crop protection, we previously reported five polyketides, the macrolides dendrodolides E () and N (), the azaphilones spiciferinone () and 8-hydroxy-spiciferinone (), and the -naphtho--pyrone cephalochromin () from the solid Potato Dextrose Agar (PDA) co-culture of two marine sediment-derived fungi, and . However, some of the purified metabolites could not be tested due to their minute quantities. Here we cultivated these fungi (both axenic and co-cultures) in liquid regime using three different media, Potato Dextrose Broth (PDB), Sabouraud Dextrose Broth (SDB), and Czapek-Dox Broth (CDB), with or without shaking. The aim was to determine the most ideal co-cultivation conditions to enhance the titers of the previously isolated compounds and to produce extracts with stronger anti-phytopathogenic activity as a basis for future upscaled fermentation. Comparative metabolomics by UPLC-MS/MS-based molecular networking and manual dereplication was employed for chemical profiling and compound annotations. Liquid co-cultivation in PDB under shaking led to the strongest activity against the phytopathogen . Except for compound , all target compounds were detected in the co-culture in PDB. Compounds and were produced in lower titers, whereas the azaphilones ( and ) were overexpressed in PDB compared to PDA. Notably, liquid PDB co-cultures contained meroterpenoids and depside clusters that were absent in the solid PDA co-cultures. This study demonstrates the importance of culture regime in BGC regulation and chemical diversity of fungal strains in co-culture studies.
Topics: Coculture Techniques; Chromatography, Liquid; Tandem Mass Spectrometry; Metabolome; Culture Media; Glucose
PubMed: 38393037
DOI: 10.3390/md22020066 -
Journal of Nematology Jun 1996Twenty-one isolates of 18 fungal species were tested on water agar for their pathogenicity to eggs of Heterodera glycines. An egg-parasitic index (EPI) for each of these...
Twenty-one isolates of 18 fungal species were tested on water agar for their pathogenicity to eggs of Heterodera glycines. An egg-parasitic index (EPI) for each of these fungi was recorded on a scale from 0 to 10, and hatch of nematode eggs was determined after exposure to the fungi on water agar for 3 weeks at 24 C. The EPI for Verticillium chlamydosporium was 7.6, and the fungus reduced hatch 74%. Pyrenochaeta terrestris and two sterile fungi also showed a high EPI and reduced hatch 42-73%. Arthrobotrys dactyloides, Fusarium oxysporum, Paecilomyces lilacinus, Stagonospora heteroderae, Neocosmospora vasinfecta, Fusarium solani, and Exophiala pisciphila were moderately pathogenic to eggs (EPI was 2.0-4.5, and hatch was reduced 21-56%). Beauveria bassiana, Hirsutella rhossiliensis, Hirsutella thompsonii, Dictyochaeta heteroderae, Dictyochaeta coffeae, Gliocladium catenulatum, and Cladosporium sp. showed little parasitism of nematode eggs but reduced hatch. A negative correlation was observed between hatch and fungal parasitism of eggs. Fusarium oxysporum, H. rhossiliensis, P. lilacinus, S. heteroderae, V. chlamydosporium, and sterile fungus 1 also were tested in soil in a greenhouse test. After 3 months, the nematode densities were lower in soil treated with H. rhossiliensis and V. chlamydosporium than in untreated soil. The nematode population densities were correlated negatively with the EPI, but not with the percentage of cysts colonized by the fungi. Plant weights and heights generally increased in the soil treated with the fungi.
PubMed: 19277130
DOI: No ID Found -
PloS One 2014Dematiaceous fungi (black fungi) are a heterogeneous group of fungi present in diverse environments worldwide. Many species in this group are known to cause allergic... (Clinical Trial)
Clinical Trial
Dematiaceous fungi (black fungi) are a heterogeneous group of fungi present in diverse environments worldwide. Many species in this group are known to cause allergic reactions and potentially fatal diseases in humans and animals, especially in tropical and subtropical climates. This study represents the first survey of dematiaceous fungi in Malaysia and provides observations on their diversity as well as in vitro response to antifungal drugs. Seventy-five strains isolated from various clinical specimens were identified by morphology as well as an internal transcribed spacer (ITS)-based phylogenetic analysis. The combined molecular and conventional approach enabled the identification of three classes of the Ascomycota phylum and 16 genera, the most common being Cladosporium, Cochliobolus and Neoscytalidium. Several of the species identified have not been associated before with human infections. Among 8 antifungal agents tested, the azoles posaconazole (96%), voriconazole (90.7%), ketoconazole (86.7%) and itraconazole (85.3%) showed in vitro activity (MIC ≤ 1 µg/mL) to the largest number of strains, followed by anidulafungin (89.3%), caspofungin (74.7%) and amphotericin B (70.7%). Fluconazole appeared to be the least effective with only 10.7% of isolates showing in vitro susceptibility. Overall, almost half (45.3%) of the isolates showed reduced susceptibility (MIC >1 µg/mL) to at least one antifungal agent, and three strains (one Pyrenochaeta unguis-hominis and two Nigrospora oryzae) showed potential multidrug resistance.
Topics: Ascomycota; Cladosporium; Cross Infection; Female; Hospitals; Humans; Malaysia; Male; Mycoses; Tropical Climate
PubMed: 25098697
DOI: 10.1371/journal.pone.0104352 -
Journal of Clinical Microbiology Oct 2006Black-grain mycetomas are subcutaneous devastating chronic infections due to several dematiaceous fungi. They are diagnosed mostly in tropical countries. Identification...
Black-grain mycetomas are subcutaneous devastating chronic infections due to several dematiaceous fungi. They are diagnosed mostly in tropical countries. Identification of these fungi with standard mycological procedures is difficult because of their poor or delayed sporulation. The aim of this study was thus to assess the accuracy of molecular identification of these fungi. A total of 54 strains, mostly of clinical origin, were used, including 15 Madurella mycetomatis, 6 Madurella grisea, 12 Leptosphaeria senegalensis, 4 Leptosphaeria tompkinsii, 6 Pyrenochaeta spp., 4 Curvularia lunata, and 7 Exophiala jeanselmei strains. The internal transcribed spacer 1 (ITS1)-5.8S-ITS2 DNA region was amplified by using universal fungal primers and sequenced. Both intra- and interspecies sequence similarities were assessed. Madurella mycetomatis appeared to be a homogeneous species. More intraspecies variations were found for C. lunata and E. jeanselmei, leading, in some instances, to changes in the initial identification. L. senegalensis and L. tompkinsii showed intraspecies similarities of >99%, but similarity between the two species was <88%. Intergenera and interspecies variations were important, with sequence homologies of <81% between genera. In contrast, Pyrenochaeta romeroi and M. grisea appeared to be heterogeneous, with intraspecies similarities of 40 to 100% and 53 to 100%, respectively, which suggest either erroneous identification or the need for taxonomic revision. Epidemiological and therapeutic studies could benefit from a precise identification of the fungi responsible for black-grain mycetoma based not only on phenotypical characteristics but also on ITS sequencing.
Topics: DNA, Fungal; DNA, Intergenic; Humans; Mitosporic Fungi; Mycoses; Phylogeny; Species Specificity
PubMed: 17021076
DOI: 10.1128/JCM.00862-06 -
Metabolites Nov 2020The interaction between plant defensive metabolites and different plant-associated fungal species is of high interest to many disciplines. Volatile organic compounds...
The interaction between plant defensive metabolites and different plant-associated fungal species is of high interest to many disciplines. Volatile organic compounds (VOCs) are natural products that are easily evaporated under ambient conditions. They play a very important role in inter-species communication of microbes and their hosts. In this study, the VOCs produced by 43 different fungal isolates of endophytic and soil fungi during growth on horseradish root () extract or malt extract agar were examined, by using headspace-gas chromatography-mass spectrometry (headspace-GC-MS) and a high relative surface agar film as a medium. The proposed technique enabled sensitive detection of several typical VOCs (acetone, methyl acetate, methyl formate, ethyl acetate, methyl butanol isomers, styrene, beta-phellandrene), along with glucosinolate decomposition products, including allyl cyanide and allyl isothiocyanate and other sulfur-containing compounds-carbon disulfide, dimethyl sulfide. The VOC patterns of fungi belonging to , , , , , , and genera were described for the first time. The VOC pattern was significantly different among the isolates. The pattern was indicative of putative myrosinase activity for many tested isolates. On the other hand, endophytes and soil fungi as groups could not be separated by VOC pattern or intensity.
PubMed: 33171636
DOI: 10.3390/metabo10110451 -
Marine Drugs Jan 2020Microbial co-cultivation is employed for awakening silent biosynthetic gene clusters (BGCs) to enhance chemical diversity. However, the selection of appropriate partners...
Microbial co-cultivation is employed for awakening silent biosynthetic gene clusters (BGCs) to enhance chemical diversity. However, the selection of appropriate partners for co-cultivation remains a challenge. Furthermore, competitive interactions involving the suppression of BGCs or upregulation of known, functional metabolite(s) during co-cultivation efforts is also common. Herein, we performed an alternative approach for targeted selection of the best co-cultivation pair. Eight marine sediment-derived fungi were classified as strong or weak, based on their anti-phytopathogenic potency. The fungi were co-cultured systematically and analyzed for their chemical profiles and anti-phytopathogenic activity. Based on enhanced bioactivity and a significantly different metabolite profile including the appearance of a co-culture specific cluster, the co-culture of (strong) and (weak) was prioritized for chemical investigation. Large-scale co-cultivation resulted in isolation of five polyketide type compounds: two 12-membered macrolides, dendrodolide E () and its new analog dendrodolide N (), as well as two rare azaphilones spiciferinone () and its new analog 8a-hydroxy-spiciferinone (). A well-known -naphtho-γ-pyrone type mycotoxin, cephalochromin (), whose production was specifically enhanced in the co-culture, was also isolated. Chemical structures of compounds - were elucidated by NMR, HRMS and [] analyses. Compound showed the strongest anti-phytopathogenic activity against and with IC values of 0.9 and 1.7 µg/mL, respectively.
Topics: Agrochemicals; Aquatic Organisms; Biological Products; Coculture Techniques; Fungi; Geologic Sediments; Industrial Microbiology; Inhibitory Concentration 50; Magnetic Resonance Spectroscopy; Metabolomics; Phytophthora infestans; Polyketides; Research Design; Xanthomonas campestris
PubMed: 31979232
DOI: 10.3390/md18020073 -
Frontiers in Microbiology 2021Manganese (Mn) oxides are among the strongest oxidants and sorbents in the environment, and Mn(II) oxidation to Mn(III/IV) (hydr)oxides includes both abiotic and...
Manganese (Mn) oxides are among the strongest oxidants and sorbents in the environment, and Mn(II) oxidation to Mn(III/IV) (hydr)oxides includes both abiotic and microbially-mediated processes. While white-rot Basidiomycete fungi oxidize Mn(II) using laccases and manganese peroxidases in association with lignocellulose degradation, the mechanisms by which filamentous Ascomycete fungi oxidize Mn(II) and a physiological role for Mn(II) oxidation in these organisms remain poorly understood. Here we use a combination of chemical and in-gel assays and bulk mass spectrometry to demonstrate secretome-based Mn(II) oxidation in three phylogenetically diverse Ascomycetes that is mechanistically distinct from hyphal-associated Mn(II) oxidation on solid substrates. We show that Mn(II) oxidative capacity of these fungi is dictated by species-specific secreted enzymes and varies with secretome age, and we reveal the presence of both Cu-based and FAD-based Mn(II) oxidation mechanisms in all 3 species, demonstrating mechanistic redundancy. Specifically, we identify candidate Mn(II)-oxidizing enzymes as tyrosinase and glyoxal oxidase in sp. SRC1lsM3a, bilirubin oxidase in sp. and AP3s5-JAC2a, and GMC oxidoreductase in all 3 species, including sp. DS3sAY3a. The diversity of the candidate Mn(II)-oxidizing enzymes identified in this study suggests that the ability of fungal secretomes to oxidize Mn(II) may be more widespread than previously thought.
PubMed: 33643238
DOI: 10.3389/fmicb.2021.610497