Fungal Cell Wall Research Articles

Penicilloneines A and B, Quinolone-Citrinin Hybrids from a Starfish-Derived Penicillium sp.

Penicilloneines A (1) and B (2) are the first reported quinolone-citrinin hybrids. They were isolated from the starfish-derived fungus Penicillium sp. GGF16-1-2, and their structures were elucidated using spectroscopic, chemical, computational, and single-crystal X-ray diffraction methods. Penicilloneines A (1) and B (2) share a common 4-hydroxy-1-methyl-2(1H)-quinolone unit; however, they differ in terms of citrinin moieties, and these two units are linked via a methylene bridge. Penicilloneines A (1) and B (2) exhibited antifungal activities against Colletotrichum gloeosporioides, with lethal concentration 50 values of 0.02 and 1.51 μg/mL, respectively. A mechanistic study revealed that 1 could inhibit cell growth and promote cell vacuolization and consequent disruption of the fungal cell walls via upregulating nutrient-related hydrolase genes, including putative hydrolase, acetylcholinesterase, glycosyl hydrolase, leucine aminopeptidase, lipase, and beta-galactosidase, and downregulating their synthase genes 3-carboxymuconate cyclase, pyruvate decarboxylase, phosphoketolase, and oxalate decarboxylase.

Antagonistic Activity of Cellulase-Producing Yeasts Isolated from Cocoa Fermentation Against Pathogenic Molds Collected from Damaged Cocoa Fruits

The presence of pathogenic molds in post-harvested cocoa beans poses a significant problem to most Indonesian farmers. Pathogenic molds secrete phytopathogenic toxins which cause rotting, seriously damaging the cocoa fruits. The common pathogenic molds found in damaged cocoa beans are Phytophthora palmivora and Phytophthora megakarya. These molds are so far controlled by using chemical pesticides, whose long-term use is potentially harmful to human health and the environment. Thus, a healthier and safer alternative is needed, especially using biological agents such as yeasts. Some yeasts produce cellulose-degrading enzymes that can possibly break down the fungal cell wall which is composed mostly of the polysaccharide’s chitin and glucan. In this study, yeasts were isolated during the cocoa fermentation process, followed by screening for cellulolytic activity using direct planting and paste method, and subsequent antagonistic testing by double culture technique. Out of 128 yeast isolates, 77 possessed cellulase activity, with 6 of them having the highest activity index. Antagonistic activity test of these 6 isolates (C1.0.4, C1.1.3, C2.3.10, C2.3.14, C3.5.11, and C3.3.1) against the pathogenic molds resulted in isolate C3.3.1 showing the highest inhibition percentage from the 2

Poacic Acid, a Plant-Derived Stilbenoid, Augments Cell Wall Chitin Production, but Its Antifungal Activity Is Hindered by This Polysaccharide and by Fungal Essential Metals.

Climate and environmental changes have modified the habitats of fungal pathogens, inflicting devastating effects on livestock and crop production. Additionally, drug-resistant fungi are increasing worldwide, driving the urgent need to identify new molecular scaffolds for the development of antifungal agents for humans, animals, and plants. Poacic acid (PA), a plant-derived stilbenoid, was recently discovered to be a novel molecular scaffold that inhibits the growth of several fungi. Its antifungal activity has been associated with perturbation of the production/assembly of the fungal cell wall β-1,3-glucan, but its mode of action is not resolved. In this study, we investigated the antifungal activity of PA and its derivatives on a panel of yeast. PA had a fungistatic effect on S. cerevisiae and a fungicidal effect on plasma membrane-damaged Candida albicans mutants. Live cell fluorescence microscopy experiments revealed that PA increases chitin production and modifies its cell wall distribution. Chitin production and cell growth returned to normal after prolonged incubation. The antifungal activity of PA was reduced in the presence of exogenous chitin, suggesting that the potentiation of chitin production is a stress response that helps the yeast cell overcome the effect of this antifungal stilbenoid. Growth inhibition was also reduced by metal ions, indicating that PA affects the metal homeostasis. These findings suggest that PA has a complex antifungal mechanism of action that involves perturbation of the cell wall β-1,3-glucan production/assembly, chitin production, and metal homeostasis.

Enhancing tomato disease resistance through endogenous antifungal proteins and introduced nematode-targeting dsRNA of biocontrol agent Bacillus velezensis HS-3.

As a type of biological control agent (BCA), Bacillus velezensis possesses the efficacy of inhibiting pathogenic microorganisms, promoting plant growth, and overcoming continuous cropping obstacles (CCOs). However, there is limited reporting on the optimization of the cultivation conditions for such biocontrol agents and their role as double-stranded RNA (dsRNA) delivery vectors. In this study, a Bacillus velezensis strain HS-3 was isolated from the root zone of tomato plants with in vitro anti-Botrytis cinerea activity. The investigation into active compounds revealed that HS-3 predominantly employs proteins with molecular weights greater than 3 kDa for its antifungal activity. Liquid chromatography-tandem mass spectrometry (LC-MS/MS) analysis identified various proteases and chitosanase, further suggesting that HS-3 most likely employs these enzymes to degrade fungal cell walls for its antifungal effect. To optimize the production of extracellular proteins, fermentation parameters for HS-3 were systematically optimized, leading to an optimized medium (OP-M). HS-3 cultured in OP-M demonstrated enhanced capacity to assist tomato plants in withstanding CCOs. However, the presence of excessive nematodes in diseased soil resulted in the disease severity index (DSI) remaining high. An RNA interference mechanism was further introduced to HS-3, targeting the nematode tyrosine phosphatase (TP) gene. Ultimately, HS-3 expressing dsRNA of TP in OP-M effectively assisted tomatoes in mitigating CCOs, reducing DSI to 2.2% and 17.8% of the control after 45 and 90 days of growth, respectively. The advantages of Bacillus velezensis in crop disease management and the mitigation of CCOs become even more pronounced when utilizing both optimized levels of endogenous enzymes and introduced nematode-targeting dsRNA. © 2024 Society of Chemical Industry.

TRICHODERMA AS A PROFICIENT BIOCONTROL AGENT FOR PHYTO-PATHOGENIC FUNGI – MECHANISM OF ACTION AND GENETIC ADVANCES

Plant disease management presently relies heavily on chemical fungicides. However, their harmful impact on human and ecosystem, and development of fungicide-resistant strains has emphasized on biological control as alternative eco-friendly strategy for disease management and sustainable agriculture. Trichoderma is a widely used as biocontrol agent against various phyto pathogenic fungi owing to its effective strategies to suppress plant pathogens. The control phenomenon involves direct mechanisms like mycoparasitism, secretion of hydrolytic enzymes which degrade the cell walls of pathogenic fungi, and indirect mechanisms like competition for resources, induction of plant defense mechanism and antibiosis. Trichoderma’s multifaceted approach to biological control makes it environment-friendly option for managing plant diseases. Recent biotechnological approaches have simplified the isolation and characterization of efficient biocontrol agents, along with the identification of their genetic by-products. These techniques facilitate the cloning of these microbes in plants, with aim to bolster their resistance to both biotic and abiotic stresses. Biotechnological advances have not only reinforced the symbiotic interaction between microbes and plants but also allowed the modification of processes through microbial biocontrol agents (MCBAs). Genome sequencing of MBCAs has provided valuable insights into their genetic makeup, aiding their characterization. The present comprehensive review provides an insight to the existing and recent molecular advances utilized to enhance the efficiency of MBCAs in managing plant diseases and understanding biocontrol mechanisms through various omics technologies.

Conversion of β-1,6-Glucans to Gentiobiose using an endo-β-1,6-Glucanase PsGly30A from Paenibacillus sp. GKG.

A plethora of di- and oligosaccharides isolated from the natural sources are used in food and pharmaceutical industry. An enzymatic hydrolysis of fungal cell wall β-glucans is a good alternative to produce the desired oligosaccharides with different functionalities, such as the flavour enhancer gentiobiose. We have previously identified PsGly30A as a potential yeast cell wall degrading β-1,6-glycosidase. The aim of this study is to characterise the PsGly30A enzyme, a member of the GH30 family, and to evaluate its suitability for the production of gentiobiose from β-1,6-glucans. An endo-β-1,6-glucanase PsGly30A encoding gene from Paenibacillus sp. GKG has been cloned and overexpressed in Escherichia coli. The recombinant enzyme has been active towards pustulan and yeast β-glucan, but not on laminarin from the Laminaria digitata, confirming the endo-β-1,6-glucanase mode of action. The PsGly30A shows the highest activity at pH 5.5 and 50 °C. The specific activity of PsGly30A on pustulan (1262±82 U/mg) is among the highest reported for GH30 β-1,6-glycosidases. Moreover, gentiobiose is the major reaction product when pustulan, yeast β-glucan or yeast cell walls have been used as a substrate. Therefore, PsGly30A is a promising catalyst for valorisation of the yeast-related by-products.

New Vision of Cell Walls in Aspergillus fumigatus from Solid-State NMR Spectroscopy.

The fungal cell wall plays a critical role in regulating cellular integrity and communication, and serves as a frontline defense against stress. It is also a prime target for the development of antifungal agents. The cell wall is comprised of diverse polysaccharides and proteins and poses a challenging target for high-resolution structural characterization. Recently, the solid-state nuclear magnetic resonance (ssNMR) analysis of intact Aspergillus fumigatus cells has provided atomic-level insights into the structural polymorphism and functional assembly principles of carbohydrate components within the cell wall. This physical perspective, alongside structural information from biochemical assays, offers a renewed understanding of the cell wall as a highly complex and dynamic organelle. Here, we summarize key conceptual advancements in the structural elucidation of A. fumigatus mycelial and conidial cell walls and their responses to stressors. We also highlight underexplored areas and discuss the opportunities facilitated by technical advancements in ssNMR spectroscopy.

Role of beta-(1→3)(1→6)-D-glucan derived from yeast on natural killer (NK) cells and breast cancer cell lines in 2D and 3D cultures

BackgroundBeta-(1,3)(1,6)-D-glucan is a complex polysaccharide, which is found in the cell wall of various fungi, yeasts, bacteria, algae, barley, and oats and has immunomodulatory, anticancer and antiviral effects. In the present study, we investigated the effect of beta-(1,3)(1,6)-D-glucan derived from yeast on the proliferation of primary NK cells and breast cancer cell lines in 2D and 3D models, and on the cytotoxicity of primary NK cells against breast cancer cell lines in 2D and 3D models.MethodsIn this study, we investigated the effects of different concentrations of yeast-derived beta-(1→3)(1→6)-D-glucan on the proliferation and cytotoxicity of human NK cells and breast cancer cell lines in 2D and 3D models using the XTT cell proliferation assay and the CellTiter-Glo® 2.0 assay to determine the cytotoxicity of human NK cells on breast cancer cell lines in 2D and 3D models.ResultsWe found that the co-incubation of NK cells with beta-glucan in the absence of IL2 at 48 h significantly increased the proliferation of NK cells, whereas the co-incubation of NK cells with beta-glucan in the presence of IL2 (70 U/ml) increased the proliferation of NK cells but not significantly. Moreover, beta-glucan significantly inhibited the proliferation of breast cancer cell lines in 2D model and induced a weak, non-significant growth inhibitory effect on breast cancer multicellular tumor spheroids (3D). In addition, the cytotoxicity of NK cells against breast cancer cell lines was examined in 2D and 3D models, and beta-glucan significantly increased the cytotoxicity of NK cells against MCF-7 (in 2D).ConclusionsYeast derived beta-(1,3)(1,6)-D-glucan could contribute to the treatment of cancer by enhancing NK cell immune response as well as contributing to inhibition of breast cancer cell growth.

Chitinase Enzyme-Producing Endophytic Bacterias From the Roots of the Plant Gembolo (Dioscorea bulbifera): Isolation, Characterization and its Potential as an Antifungal Agent

Chitinase is an enzyme of the chitinolytic group that has many roles in agriculture, especially as an antifungal, because chitin is one of the constituent components of the fungal cell wall. This study aimed to isolate and identify endophytic bacteria from gembolo (Dioscorea bulbifera) roots and to characterize the chitinase enzyme from these endophytic bacteria to be used as an antifungal. Isolation and identification of gembolo plant root endophytic bacteria using PCR method of 16S rRNA gene amplification and sequencing. Characterization of the chitinase enzyme produced includes determining of optimum pH, temperature, and substrate UV-Vis spectrophotometer. Antagonistic test of the chitinase enzyme and endophytic bacterial isolates (isolate K4) Fusarium oxysporum. The results showed that bacterial isolate K4 had with chitinolytic index of 2.45 mm. Electrophoresis results with PCR 16s rRNA gene; the length of the amplified fragment is the position of 1300 bp. By doing the BLAST process in GenBank, the bacterial isolate has 97.93% similarity with Enterobacter cloacae. Then, this endophytic bacteria is called Enterobacter cloacae K4-G. This bacterium produced chitinase enzyme reaching maximum chitinase activity at the 38 hours with an activity of 0.0312 U/mL. The chitinase characterization results of E. cloacae K4-G showed that the optimum conditions were reached at at pH 6, temperature 45 ᵒC, and 2.5% substrate with a chitinase activity value of 0.2467 U/mL. Chitinase enzyme and bacteria Enterobacter cloacae K4-G can inhibit the growth of the fungus Fusarium oxysporum. Therefore, Chitinase from Enterobacter cloacae K4-G can be used as an antifungal pathogen in plants.
 
 Keywords: Chitinase, endophytic bacteria, Enterobacter cloacae

Antifungal activity of Fe3O4@SiO2/Schiff-base/Cu(II) magnetic nanoparticles against pathogenic Candida species

The antifungal efficacy and cytotoxicity of a novel nano-antifungal agent, the Fe3O4@SiO2/Schiff-base complex of Cu(II) magnetic nanoparticles (MNPs), have been assessed for targeting drug-resistant Candida species. Due to the rising issue of fungal infections, especially candidiasis, and resistance to traditional antifungals, there is an urgent need for new therapeutic strategies. Utilizing Schiff-base ligands known for their broad-spectrum antimicrobial activity, the Fe3O4@SiO2/Schiff-base/Cu(II) MNPs have been synthesized. The Fe3O4@SiO2/Schiff-base/Cu(II) MNPs was characterized by Fourier Transform-Infrared Spectroscopy (FT-IR), X-ray Diffraction (XRD), Transmission Electron Microscopy (TEM), Scanning Electron Microscopy (SEM), Dynamic Light Scattering (DLS), Energy-dispersive X-ray (EDX), Vibrating Sample Magnetometer (VSM), and Thermogravimetric analysis (TGA), demonstrating successful synthesis. The antifungal potential was evaluated against six Candida species (C. dubliniensis, C. krusei, C. tropicalis, C. parapsilosis, C. glabrata, and C. albicans) using the broth microdilution method. The results indicated strong antifungal activity in the range of 8–64 μg/mL with the lowest MIC (8 μg/mL) observed against C. parapsilosis. The result showed the MIC of 32 μg/mL against C. albicans as the most common infection source. The antifungal mechanism is likely due to the disruption of the fungal cell wall and membrane, along with increased reactive oxygen species (ROS) generation leading to cell death. The MTT (3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide) assay for cytotoxicity on mouse L929 fibroblastic cells suggested low toxicity and even enhanced cell proliferation at certain concentrations. This study demonstrates the promise of Fe3O4@SiO2/Schiff-base/Cu(II) MNPs as a potent antifungal agent with potential applications in the treatment of life-threatening fungal infections, healthcare-associated infections, and beyond.

Mesoporous zinc oxide-based drug delivery system offers an antifungal and immunoregulatory strategy for treating keratitis

Fungal keratitis is a refractory eye disease that is prone to causing blindness. Fungal virulence and inflammatory responses are two major factors that accelerate the course of fungal keratitis. However, the current antifungal drugs used for treatment usually possess transient residence time on the ocular surface and low bioavailability deficiencies, which limit their therapeutic efficacy. In this work, natamycin (NATA)-loaded mesoporous zinc oxide (Meso-ZnO) was synthesized for treating Aspergillus fumigatus keratitis with excellent drug-loading and sustained drug release capacities. In addition to being a carrier for drug delivery, Meso-ZnO could restrict fungal growth in a concentration-dependent manner, and the transcriptome analysis of fungal hyphae indicated that it inhibited the mycotoxin biosynthesis, oxidoreductase activity and fungal cell wall formation. Meso-ZnO also promoted cell migration and exhibited anti-inflammatory role during fungal infection by promoting the activation of autophagy. In mouse models of fungal keratitis, Meso-ZnO/NATA greatly reduced corneal fungal survival, alleviated tissue inflammatory damage, and reduced neutrophils accumulation and cytokines expression. This study suggests that Meso-ZnO/NATA can be a novel and effective treatment strategy for fungal keratitis.

Histatin 5-Inspired Short-Chain Peptides Selectively Combating Pathogenic Fungi with Multifaceted Mechanisms.

Short-chain antifungal peptides (AFPs) inspired by histatin 5 have been designed to address the problem of antifungal drug resistance. These AFPs demonstrate remarkable antifungal activity, with a minimal inhibitory concentration as low as 2µg mL-1. Notably, these AFPs display a strong preference for targeting fungi rather than bacteria and mammalian cells. This is achieved by binding the histidine-rich domains of the AFPs to the Ssa1/2 proteins in the fungal cell wall, as well as the reduced membrane-disrupting activity due to their low amphiphilicity. These peptides disrupt the nucleus and mitochondria once inside the cells, leading to reactive oxygen species production and cell damage. In a mouse model of vulvovaginal candidiasis, the AFPs demonstrate not only antifungal activity, but also promote the growth of beneficial Lactobacillus spp. This research provides valuable insights for the development of fungus-specific AFPs and offers a promising strategy for the treatment of fungal infectious diseases.

Effect of pH on Trace Elements Removal from Batteries and Compact Disks by Aspergillus terreus Pellets

Background: The aim of this study is the removal of three trace elements (Nickle Ni, Cadmium Cd and Lead Pb) by an environmentally friendly method from Batteries and compact discs. This study aimed to rapidly remove trace elements from E-waste (batteries) by filamentous fungi pellets. Methods: Aspergillus was the best heavy metal tolerated isolate under the following incubation parameters: pH (5), temperature (25°C), ground electronic waste powder doses (0.5, 1 and 1.5 g/L) absorbed by fungal pellets biomass 10 gm/L of wet weight. Result: The results showed the best removal percentage R% of Ni, Cd and Pb removal were (89,91and 96) observed at pH 5. Images from SEM showed accumulations of metal particles on the surface of the fungal hyphae and Fourier Transform Infra-Red Spectroscopy (FT-IR) was used to determine the effective groups in the fungal cell wall responsible of biosorption of trace elements and This study indicates that an application may be possible Aspergillus terreus as a promising candidate for biological sorption and recycling of trace elements and as an ecologically friendly and effective process in terms of time and cost.

Proteomic Analysis of Cell Wall Proteins with Various Linkages in Fusarium graminearum.

The fungal cell wall, primarily comprising a glucan-chitin matrix and cell wall proteins (CWPs), serves as a key mediator for fungal interactions with the environment and plays a pivotal role in virulence. In this study, we employed a comprehensive proteomics approach to analyze the CWPs in the plant pathogenic fungus Fusarium graminearum. Our methodology successfully extracted and identified 1373 CWPs, highlighting their complex linkages, including noncovalent bonds, disulfide bridges, alkali-sensitive linkages, and glycosylphosphatidylinositol (GPI) anchors. A significant subset of these proteins, enriched in Gene Ontology terms, suggest multifunctional roles of CWPs. Through the integration of transcriptomic and proteomic data, we observed differential expression patterns of CWPs across developmental stages. Specifically, we focused on two genes, Fca7 and Cpd1, which were upregulated in planta, and confirmed their localization predominantly outside the plasma membrane, primarily in the cell wall and periplasmic space. The disruption of FCA7 reduced virulence on wheat, aligning with previous findings and underscoring its significance. Overall, our findings offer a comprehensive proteomic profile of CWPs in F. graminearum, laying the groundwork for a deeper understanding of their roles in the development and interactions with host plants.

Colonic in vitro fermentation of mycoprotein promotes shifts in gut microbiota, with enrichment of Bacteroides species

Mycoprotein is a fungal-derived ingredient used for meat alternative products whose fungal cell walls are rich in dietary fibre (β-glucans and chitin) and defines its structure. Several health benefits have been reported after mycoprotein consumption, however, little is known about the impact of mycoprotein fermentation on the gut microbiota. This study aims to identify changes in microbiome composition and microbial metabolites during colonic fermentation of mycoprotein following simulated upper gastrointestinal digestion. Changes in microbial populations and metabolites produced by the fermentation of mycoprotein fibre were investigated and compared to a plant (oat bran) and an animal (chicken) comparator. In this model fermentation system, mycoprotein and oat showed different but marked changes in the microbial population compared to chicken, which showed minimal differentiation. In particular, Bacteroides species known for degrading β-glucans were found in abundance following fermentation of mycoprotein fibre. Mycoprotein fermentation resulted in short-chain fatty acid production comparable with oat and chicken at 72 h. Significantly higher branched-chain amino acids were observed following chicken fermentation. This study suggests that the colonic fermentation of mycoprotein can promote changes in the colonic microbial profile. These results highlight the impact that the unique structure of mycoprotein can have on digestive processes and the gut microbiota.

In vitro biological control of Pyrrhoderma noxium using volatile compounds produced by termite gut-associated streptomycetes.

Pyrrhoderma noxium is a plant pathogen that causes economic losses in agricultural and forestry industries, including significant destruction to amenity trees within the city of Brisbane in Australia. Use of chemical control agents are restricted in public areas, there is therefore an urgent need to investigate biological control approaches. Members of the phylum Actinomycetota, commonly known as actinomycetes, are known for their industrially important secondary metabolites including antifungal agents. They have proven to be ideal candidates to produce environmentally friendly compounds including the volatile organic compounds (VOCs) which can be used as biofumigants. Different Streptomyces species (n=15) previously isolated from the guts of termites and stored in the University of the Sunshine Coast'sMicrobial Library were tested for their antifungal VOCs against Pyrrhoderma noxium. Fourteen of them were found to display inhibition (39.39-100%) to the mycelial development of the pathogen. Strongest antifungal activity displaying isolates USC-592, USC-595, USC-6910 and USC-6928 against the pathogen were selected for further investigations. Their VOCs were also found to have plant growth promotional activity observed for Arabidopsis thaliana with an increase of root length (22-36%) and shoot length (26-57%). The chlorophyll content of the test plant had a slight increase of 11.8% as well. Identified VOCs included geosmin, 2-methylisoborneol, 2-methylbutyrate, methylene cyclopentane, β-pinene, dimethyl disulfide, ethyl isovalerate, methoxyphenyl-oxime and α-pinene. Additionally, all 15 Streptomyces isolates were found to produce siderophores and indole acetic acid as well as the enzyme chitinase which is known to break down the fungal cell wall. Findings indicate that termite gut-associated streptomycetes might be used to control Pyrrhoderma noxium by utilizing their wide range of inhibitory mechanisms.

Recent Developments and Future Prospects of Natural Antimicrobial Bioactive Metabolites Obtained from Endophytic Bacterial Isolate

Background: Adathoda beddomei (Adosa), a kind of softwood, evergreen, perennial shrub, has been used as a source of endophyte bacteria. Adhatoda beddomei has a wide variety of chemicals, including anthocyanins, aminophylline, alkaloids, cardiac glycosides, isoprenaline, triterpenoids, resins, flavonoids, tannins, sterol, saponins, etc. The root, stem, and leaf parts of Adathoda beddomei are most often used in indigenous medicine. Moreover, the root bark is also used to cure several conditions, including leprosy, fever, and bleeding. Objective: Some important bioactive metabolites were obtained from endophytes bacteria and analyzed through various techniques (NMR, MASS, FTIR, HPLC, and UV- spectrophotometer) for their bioactive secondary metabolites. Methods: In silico calculation was performed to reveal bioactive metabolites with the potential to be antibacterial, and their primary mode of action may include dissolving bacterial and fungal cell walls. Results: The antimicrobial activity of Adathoda beddomei was demonstrated against different pathogenic and non-pathogenic bacteria. Identification of endophytes was done based on external morphological characteristics with the help of a scanning electron microscope (SEM). Conclusion: Natural compounds derived from endophyte bacteria with a very low molecular mass can be used to discover new and important structures for different pharmaceuticals and agrochemicals.

Fungal Cell Wall-Associated Effectors: Sensing, Integration, Suppression, and Protection.

The cell wall (CW) of plant-interacting fungi, as the direct interface with host plants, plays a crucial role in fungal development. A number of secreted proteins are directly associated with the fungal CW, either through covalent or non-covalent interactions, and serve a range of important functions. In the context of plant-fungal interactions many are important for fungal development in the host environment and may therefore be considered fungal CW-associated effectors (CWAEs). Key CWAE functions include integrating chemical/physical signals to direct hyphal growth, interfering with plant immunity, and providing protection against plant defenses. In recent years, a diverse range of mechanisms have been reported that underpin their roles, with some CWAEs harboring conserved motifs or functional domains, while others are reported to have novel features. As such, the current understanding regarding fungal CWAEs is systematically presented here from the perspective of their biological functions in plant-fungal interactions. An overview of the fungal CW architecture and the mechanisms by which proteins are secreted, modified, and incorporated into the CW is first presented to provide context for their biological roles. Some CWAE functions are reported across a broad range of pathosystems or symbiotic/mutualistic associations. Prominent are the chitin interacting-effectors that facilitate fungal CW modification, protection, or suppression of host immune responses. However, several alternative functions are now reported and are presented and discussed. CWAEs can play diverse roles, some possibly unique to fungal lineages and others conserved across a broad range of plant-interacting fungi. [Formula: see text] Copyright © 2024 The Author(s). This is an open access article distributed under the CC BY 4.0 International license.

Clinicopathological study of pigmented fungal lesions with special reference to subcutaneous phaeohyphomycosis: A 3-year study in a tertiary care hospital of Eastern India

Background: Fungal infections are predominantly opportunistic infections in immunocompromised patients and in immunocompetent adults with a history of trauma. Recently, there is an increase in trends of fungal infections in immunocompetent individuals also without any history of trauma. Pigmented fungi are a group of fungi that have pigment in their cell wall and also known as dematiaceous fungi. These pigmented fungi include phaeohyphomycosis with a differential diagnosis of chromoblastomycosis, cryptococcosis, mycetoma, and aspergillus. Phaeohyphomycosis is a subcutaneous or systemic infection characterized histologically by dark-colored fungal hyphae and yeast forms (black yeast). Aims and Objectives: The aim of the present study is to analyze the clinicopathological features of pigmented fungal infections in biopsy specimen based on their histomorphology. Materials and Methods: This was a prospective study in which we have analyzed the dematiaceous fungal species by their histomorphological characteristics in biopsy specimens. Results: A total of 21 cases of biopsy specimens (with the clinical presentation of cutaneous/subcutaneous lesions) were studied histologically which showed 13 cases of phaeohyp homycosis, seven cases of eumycotic mycetoma, and one case of chromoblastomycosis. There was male predominance (17, 80.95%) and the majority of the patients were >60 years (16, 76.19%). Most common site of infection was foot with predominant clinical presentation as subcutaneous mass lesion. Conclusion: All the cases of dematiaceous fungal infections were diagnosed by histopathological examination. Melanin in the cell wall of dematiaceous fungi is the pathogenic factor. Phaeohyphomycosis is no longer considered as a rare infection rather there is an increasingly incidence of recognized infection. Although culture and histopathological study remain important tools for final diagnosis, various molecular studies might be helpful for accurate diagnosis.

Breaking-Down Barriers: Proposal of Using Cellulose Biosynthesis Inhibitors and Cellulase Enzyme as a Novel Treatment Modality for Vision Threatening Pythium Insidiosum Keratitis.

Pythium insidiosum, an Oomycete, causes severe keratitis that endangers vision. Its clinical, morphological, and microbiological characteristics are often indistinguishable from those of fungal keratitis, earning it the moniker "parafungus". Distinctive clinical hallmarks that set it apart from other forms of keratitis include radial keratoneuritis, tentacles, marginal infiltration, and a propensity for rapid limbal spread. The therapeutic approach to Pythium keratitis (PK) has long been a subject of debate, and topical and systemic antifungals and antibacterials have been tried with limited success. Approximately 80% of these eyes undergo therapeutic keratoplasty to salvage the eye. Hence, there is a need to innovate for alternative and better medical therapy to safeguard these eyes. The resistance of Pythium to standard antifungal treatments can be attributed to the absence of ergosterol in its cell wall. Cell walls of plants and algae have cellulose as an essential constituent. Cellulose imparts strength and structure and acts as the "skeleton" of the plant. Fungal and animal cell walls typically lack cellulose. The cellular architecture of Pythium shares a similarity with plant and algal cells through the incorporation of cellulose within its cell wall structure. Inhibitors targeting cellulose biosynthesis (CBI), such as Indaziflam, Isoxaben, and Quinoxyphen, serve as critical tools for elucidating the pathways of cellulose synthesis. Furthermore, the enzymatic action of cellulase is instrumental for the extraction of proteins and DNA. To circumvent this issue, we hypothesize that CBI's and cellulase enzymes can act on the Pythium cell wall and may effectively treat PK. The available literature supporting the hypothesis and proof of concept has also been discussed. We have also discussed these drugs' molecular mechanism of action on the Pythium cell wall. We also aim to propose how these drugs can be procured and used as a potential medical management option for this devastating entity.