Search Results (5,578)

Macrofungi are key decomposers of organic matter and play an active role in biogeochemical cycles, thereby contributing to carbon sequestration in forest ecosystems. Floodplain forests (várzeas) are characterized by the dynamics of rising and receding waters, which are rich in suspended material and influence species variation and adaptation. The knowledge about the distribution of macrofungi in várzea environments in the Brazilian Amazon is limited. This study aims to evaluate the diversity and composition of macrofungi on three várzea forest islands, while also examining differences in species richness and abundance between seasonal periods. A total of 88 macrofungal species that belong to the phylum Basidiomycota were identified. The findings revealed significant variations in species composition, yet no notable differences in species richness or abundance were observed between the seasonal periods. The environmental conditions and resources available to macrofungi appear to be consistent among the islands, which leads to a balanced diversity. However, additional research is essential to uncover the true distribution patterns of macrofungi in the várzeas of the Brazilian Amazon, an area under significant threat to its biodiversity. Full article

Tinea nigra (TN) is a superficial fungal infection caused by the melanized fungus Hortaea werneckii, characterized by irregular dark patches, typically on the palms. This systematic review aims to evaluate the epidemiology, demographic characteristics, lesion distribution, diagnostic approaches, causative agents, and treatment outcomes of TN. The PubMed and MEDLINE databases were systematically searched using relevant keywords from January 1990 to January 2025, yielding a total of 102 cases across 42 studies. TN is more prevalent in tropical regions, with a higher incidence in the Americas (64 cases), particularly Mexico (23 cases), Brazil (17 cases), and Cuba (8 cases). The infection is more commonly observed in females (58 cases) than males (44 cases), with a mean patient age of 16.7 years (SD ± 13.58). The most frequently affected anatomical site is the palm, with 41 cases on the left palm, 34 on the right, and 5 involving both palms. Other affected sites include the soles and interdigital areas. Diagnosis typically involves direct microscopic examination using potassium hydroxide (KOH) preparation, which was performed in all cases, while cultures were conducted in 96 cases and dermoscopy was used in 14 cases. Hortaea werneckii was the predominant species isolated (74 cases), followed by Exophiala werneckii (14 cases), Pullularia werneckii (4 cases), and Aureobasidium melanogenum (3 cases). Recently, a new etiologic agent, Cyphellophora ludoviensis, was reported, among others. Over 25 treatment modalities were reported, with topical therapies being the most common. Whitfield’s ointment was used in 12 cases, followed by ketoconazole 2% cream (11 cases), and terbinafine 1% cream and isoconazole 1% cream (10 cases each). Spontaneous resolution occurred in two cases. The average treatment duration across all modalities was 4 weeks, with a 100% resolution rate. This systematic review emphasizes the importance of understanding TN’s clinical presentation, diagnostic techniques, and therapeutic strategies to optimize patient care and guide future research on this relatively uncommon fungal infection. Full article

Caves can be regarded as extreme environments, and fungi are known as omnipresent and highly adaptable organisms that can easily colonize such environments. The primary objective of this study was to use the statistical analysis of sequences stored in the NCBI database, together with related metadata, to find and uncover statistically significant distribution patterns of fungi occupying different substrata inside the caves. The obtained list included a total of 1447 sequences corresponding to fungi isolated from various substrata within cave environments around the world, which corresponds to 445 fungal species, members of the 394 genera. Ascomycota was the most dominant phylum and Eurotiomycetes the dominant class of fungal dwellers in these environments. The highest species richness is detected for the genus Penicillium (57), followed by Aspergillus (51). On the other hand, the most frequently documented single species was Pseudogymnoascus destructans, isolated mostly from hibernating bats and guano, followed by Penicillium chrysogenum. Because caves have stable, nutrient-limited, low-competition microhabitats that support unusual or cryptic species, many new fungal taxa have been reported as well (such as Aspergillus, Apiotrichum, and Cephalotrichum species). Finally, cutting-edge molecular technologies and better sampling methods are revealing hitherto undiscovered fungal diversity in caves worldwide. Full article

An in vitro 3D model using fungus colonized Reconstructed Human Epidermis (RHE) represents an effective preclinical model to simulate the pathological conditions of onychomycosis. We evaluated the suitability of this 3D onychomycosis model and use it to assess the effects of topical products on fungus growth and nail structure. Five sets of differentiated RHE were colonized with Trichophyton rubrum and covered with bovine nails. Colonized RHE with no product application (CNA) served as the control. Four different products classified as medical devices were applied once daily on the nails: Urgo Damaged Nails (UDN), Excilor (EXlor), Poderm Purifying (PDermP), Poderm Booster (PDermB). After 5 days, T. rubrum presence was visualized by the Grott Methenamine Silver staining method and quantified as the sum signal intensity of processed acquisitions. Fungal hyphae and the nail structure were analyzed by SEM. A semi-quantitative evaluation of fungal presence showed a reduction after UDN (−34%, p < 0.001) and EXlor (−28%, p < 0.020) applications compared to CNA. No significant difference was observed after PDermP applications (−2%). The nail structure appeared preserved after UDN applications and severely damaged after EXlor and PDermP applications. These findings demonstrate significant effects of different products on fungal growth and nail structure, suggesting that this 3D model might be a valuable tool for predicting the effects of antimycotic treatment in humans. Full article

Candida glabrata is an opportunistic, pathogenic fungus that is increasingly isolated from hospitalized patients. The incidence of drug tolerance, heteroresistance, and resistance is on the rise due to an overuse of antifungal drugs. The aim of this study was to expose a sensitive C. glabrata strain to sequentially increasing concentrations of two antifungal drugs, fluconazole, an azole that targets ergosterol biosynthesis, or caspofungin, an echinocandin that targets cell wall glucan synthesis. Analysis of the drug-exposed isolates showed development of antifungal tolerance, chromosomal abnormalities, decreased adhesion, attenuated virulence, and an increase in efflux pump activity. Furthermore, whole genome sequencing of all isolates exposed to different concentrations of fluconazole or caspofungin was performed to determine mutations in key genes that could correlate with the observed phenotypes. Mutations were found in genes implicated in adhesion, such as in the AWP, PWP, and EPA family of genes. Isolates exposed to higher drug concentrations displayed more mutations than those at lower concentrations. Full article

Recently, Fusarium root rot (FRR)-like symptoms were observed in Uganda’s agroecology zones, prompting the National Agricultural Organisation (NARO) to conduct a disease survey. The survey reports indicated FRR as the second most prevalent root rot disease of common bean in Uganda after Southern blight. Ninety nine Fusarium spp. strains were obtained from samples collected during the surveys. The strains were morphologically and pathogenically characterised and confirmed to cause Fusarium root rot as observed in the field. However, molecular characterization of the strains was not conducted. In this study, therefore, 80 of the strains were characterized using partial sequences of translation elongation factor 1-alpha (TEF-1α) gene, beta tubulin (β tubulin) gene and internal transcribed spacers (ITS) region of ribosomal RNA to determine species diversity. High-quality Sanger sequences from the target genes were compared to the sequences from Fusarium species available in the National Centre for Biotechnology Information coding sequences (NCBI-CDS) database to determine the most likely species the strains belonged. The sequences from our strains were deposited into the NCBI gene bank under ID#288420, 2883276, 2873058 for TEF-1α, β tubulin and ITS respectively. The Fusarium species identified included; F. oxysporum, F. solani, F. equiseti F. delphinoides, F. commune, F. subflagellisporum, F. fabacearum, F. falciforme, F. brevicaudatum, F. serpentimum, F. fredkrugeri and F. brachygibbosum. The diversity of these Fusarium species needs to be taken into consideration when developing breeding programs for management of the disease since currently there is no variety of common bean resistant to FRR in Uganda. Full article

Codon optimization is a widely employed strategy to enhance protein expression. However, it occasionally leads to unexpected transcriptional repression despite preserving amino acid sequences. This study investigates the mechanistic basis of such transcriptional attenuation by analyzing two gene candidates (0432 and Fluc) in the common expression chassis P. pastoris. Both genes experienced severe mRNA reduction following codon optimization. Evidenced by histone H3 chromatin immunoprecipitation (ChIP) and a DNase I hypersensitivity assay, gene sequences with transcriptional repression displayed elevated nucleosome occupancy and reduced chromatin accessibility. The above change was caused by an ORF sequence change independent of the promoter, since transcriptional attenuation and compromised chromatin accessibility were still observed after replacing the strong promoter P_GAP with P_por1 or P_rps8b. Our findings challenge the conventional view of codon optimization as solely translation-centric, revealing its capacity to preemptively modulate transcription through chromatin accessibility. This work underscores the necessity of integrating chromatin-level considerations into synthetic gene design to avoid unintended transcriptional silencing and optimize expression outcomes. Full article

Invasive fungal diseases are a significant threat in immunocompromised patients, underscoring the need for rapid and accurate diagnostics. This study describes the development and validation of a real-time PCR-based laboratory-developed assay (LDA) on the Panther Fusion system for the simultaneous detection of Aspergillus fumigatus (AF) and Pneumocystis jirovecii (PJ) in bronchoalveolar lavage fluid (BALF) samples. The assay was evaluated using 239 clinical BALF samples, including cases confirmed positive for AF or PJ by reference mycological methods. Rigorous optimization ensured compatibility with the automated workflow of the Panther Fusion system, which addresses challenges such as BALF viscosity and fungal DNA recovery. No cross-reactivity with non-target fungal species was observed, and the assay demonstrated high analytical sensitivity and specificity. Only two false-negative results were reported, which could plausibly be reclassified as true negatives when interpreted alongside the serum beta-d-glucan and galactomannan assay results. For PJ detection, the assay showed excellent concordance with the OLM PneumID assay, supporting its reliability in clinical settings. The dual-target approach facilitates the simultaneous detection of both pathogens within a single workflow, improving diagnostic efficiency. The AF/PJ LDA represents a robust and scalable alternative to existing molecular assays, with the potential to enhance routine diagnostics for pulmonary fungal infections. Full article

The aim of this study is to share our experience regarding the diagnosis and therapeutic management of primary cutaneous aspergillosis (PCA) in the burn patient, an uncommon infection associated with increased mortality, morbidity, and treatment costs. The uniqueness of this article is the presence of PCA in pediatric patients where the Meek micrografting technique was used. We performed a retrospective study from June 2020 to November 2024. The inclusion criteria were the concomitant presence of burn injuries and confirmed PCA. We identified six patients, aged between 12 and 17 years, admitted with deep burns ranging from 55% to 90% of the total body surface area (TBSA). They required complex ICU treatment and underwent extensive excision–grafting surgeries. The suspicion of infection was raised by changes in the appearance of wounds. Systemic and topical antifungal treatment was established in patients after a PCA diagnosis. Five out of the six cases had a favorable outcome. The use of the Meek micrografting technique in burn treatment represents a new challenge in the treatment of PCA due to the polyamide gauze that covers the micrografts. Early detection and appropriate topical antifungal agents combined with systemic treatment may save the infected grafts and limit the infection spread without necessarily removing the polyamide gauze. Full article

The human gastrointestinal tract harbors a vast array of microorganisms, which play essential roles in maintaining metabolic balance and immune function. While bacteria dominate the gut microbiome, fungi represent a much smaller, often overlooked fraction. Despite their relatively low abundance, fungi may significantly influence both health and disease. Advances in next-generation sequencing, metagenomics, metatranscriptomics, metaproteomics, metabolomics, and computational biology have provided novel opportunities to study the gut mycobiome, shedding light on its composition, functional genes, and metabolite interactions. Emerging evidence links fungal dysbiosis to various diseases, including inflammatory bowel disease, colorectal cancer, metabolic disorders, and neurological conditions. The gut mycobiome also presents a promising avenue for precision medicine, particularly in biomarker discovery, disease diagnostics, and targeted therapeutics. Nonetheless, significant challenges remain in effectively integrating gut mycobiome knowledge into clinical practice. This review examines gut fungal microbiota, highlighting analytical methods, associations with human diseases, and its potential role in precision medicine. It also discusses pathways for clinical translation, particularly in diagnosis and treatment, while addressing key barriers to implementation. Full article

The role of calcium, an essential secondary messenger, in cell division remains an outstanding question in cell biology despite several significant findings over the past few decades. Among them is the landmark discovery of intracellular calcium waves during cytokinesis, the last stage of cell division, in fish cells. Nevertheless, subsequent studies have been largely unable to determine the underlying molecular mechanism of these cytokinetic transients. At the center of this stalemate stands two challenging questions, how these calcium transients rise and what they do during cytokinesis. Yeast, despite its proven prowess as a model organism to study cell cycle, has not drawn much interest in addressing these questions. However, the recent discovery of cytokinetic calcium spikes in the fission yeast Schizosaccharomyces pombe has provided novel insights into how calcium regulates cytokinesis. In this review, I will primarily focus on our current understanding of the molecular mechanism of cytokinetic calcium transients in yeast cells. First, I will briefly recount the discovery of cytokinetic calcium transients in animal cells. This will be followed by an introduction to the intracellular calcium homeostasis. Next, I will discuss yeast cytokinetic calcium spikes, the ion channel Pkd2 that promotes these spikes, and the potential molecular targets of these spikes. I will also compare the calcium regulation of cytokinesis between yeast and animal cells. I will conclude by presenting a few critical questions in our continued quest to understand how calcium regulates cytokinesis. Full article

Schizophyllum commune, a Basidiomycota fungus with a tetrapolar mating system, serves as a key model for studying sexual reproduction. In this study, two distinct mating subtypes (I and II) were identified in strain 20R-7-ZF01, isolated from subseafloor sediment, which exhibited eight different mating interaction phenotypes. Intra-subtypes exhibited colony-symmetric tetrapolar interactions (G1), whereas inter-subtype crosses yielded colony-asymmetric phenotypes (G2) and a reduced number of fruiting bodies. Nuclear migration analysis revealed that both subtypes follow the same sexual reproductive process, suggesting functional similarities despite the different reproductive outcomes. Gene silencing of mating-type loci identified the genes bbp2-9 and bbp2-7 within the B locus as key factors in determining mating subtype identity. Additionally, a similar pattern of mating subtype differentiation was observed in five other S. commune strains from both subseafloor and terrestrial environments. These findings highlight the genetic diversity within S. commune, challenge the classical understanding of fungal mating systems, and provide new insights into the genetic evolutionary mechanisms governing fungi with tetrapolar mating systems. Full article

Endophytic fungi provide valuable sources for the discovery of secondary metabolites that can be used as lead compounds in drug discovery. In this study, four new sesquiterpenoids with a farnesane backbone, schizophyllol A–B (1–2) and schizophylloside A–B (3–4), together with five known analogues (5–9), were isolated from the plant-derived fungus Schizophyllum sp. HM230. Their structures were established through extensive spectroscopic analyses including HR-ESI-MS and 1D and 2D NMR. The antioxidant activities of all the isolated compounds (compounds 1–9) were evaluated via hydroxyl radical scavenging, DPPH free radical scavenging, and superoxide anion radical scavenging assays. Compounds 1 and 2 displayed stronger antioxidant capacities than the positive control tert-butylhydroquinone. Furthermore, the antifungal activities of the isolated compounds were evaluated against four phytopathogenic fungi: Sclerotinia ginseng, Rhizoctonia solani, Cylindrocarpon destructans, and Exserohilum turcicum. All the test compounds demonstrated inhibitory effects; notably, compound 4 exhibited the strongest activities against the four selected phytopathogenic fungi, with inhibitory rates ranging from 42.3% to 65.4% at 0.2 mg/mL. Full article

The Qinghai-Tibet Plateau, known as “the third pole” of the Earth, boasts unique climatic conditions with abundant sunlight, low temperature, and significant annual temperature variations, nurturing a diverse array of soil microorganisms with rich metabolic products. In this study, 132 fungal isolates were isolated and identified from the soil samples collected in Nyingchi, Tibet, belonging to 32 genera and 59 species, while Ascomycota, Mucoromycota, and Basidiomycota accounted for 91.7%, 7.5%, and 0.8%, respectively. The evolutionary relationships among 59 representative strains were revealed by constructing a phylogenetic tree, while Penicillium, Fusarium, and Aspergillus were the most widespread fungal genera here, and the antibacterial activity of these strains was evaluated by the agar diffusion assay, leading to 27 active strains. Notably, six of them demonstrated significant activities against two or more tested bacteria. The antibacterial efficacy of the extracts of these six fungi, which were derived from four distinct media, was further evaluated at a concentration of 500 μg/mL. This study provides a valuable supplement to the investigations of cultivable soil fungi in Nyingchi, Tibet, laying a foundation for the development of soil fungi and antibacterial lead compounds in the area. Full article