RESUMEN
Candida albicans is an opportunistic fungal pathogen that can cause systemic infections in immunocompromised individuals. Morphological transition and biofilm formation are major virulence factors of C. albicans. Moreover, biofilm enhances resistance to antifungal agents. Therefore, it is urgent to identify new and effective compounds to target the biofilm of C. albicans. In the present study, the antifungal activities of equol against C. albicans were investigated. In vitro, the microdilution analysis and spot assay result showed that equol exhibited potent inhibitory activities against C. albicans. Further investigations confirmed that the antifungal effects of equol involved interference with the transition from yeast to hypha and biofilm formation of C. albicans. In addition, transcriptome sequencing and reverse transcription-quantitative PCR (qRT-PCR) analysis showed that equol significantly downregulated the expression of several genes in the Ras1-cAMP-PKA pathway related to hyphae and biofilm formation and significantly upregulated the expression of the negative transcriptional repressors RFG1 and TUP1. Moreover, equol effectively reduced the production of cAMP, a key messenger in the Ras1-cAMP-PKA pathway, while supplementation with cAMP partly rescued the equol-induced defects in hyphal development. Furthermore, in a mouse model of systemic candidiasis (SC), equol treatment significantly decreased the fungal burden (liver, kidneys, and lung) in mice and local tissue damage, while enhancing the production of interleukin-10 (IL-10). Together, these findings confirm that equol is a potentially effective agent for treatment of SC.
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Antifúngicos , Biopelículas , Candida albicans , Candidiasis , Equol , Candida albicans/efectos de los fármacos , Candida albicans/genética , Animales , Biopelículas/efectos de los fármacos , Biopelículas/crecimiento & desarrollo , Antifúngicos/farmacología , Antifúngicos/uso terapéutico , Ratones , Candidiasis/microbiología , Candidiasis/tratamiento farmacológico , Equol/farmacología , Femenino , Modelos Animales de Enfermedad , Pruebas de Sensibilidad Microbiana , Hifa/efectos de los fármacos , Hifa/crecimiento & desarrollo , Regulación Fúngica de la Expresión Génica/efectos de los fármacos , Ratones Endogámicos BALB C , Proteínas Fúngicas/genética , Proteínas Fúngicas/metabolismoRESUMEN
Replicating the complex 3D microvascular architectures found in biological systems is a critical challenge in tissue engineering and other fields requiring efficient mass transport. Conventional microfabrication techniques often face limitations in creating extensive hierarchical networks, especially within bulk materials. Here, we report a versatile bioinspired approach to generate optimized 3D microvascular networks within transparent glass matrix by transcribing the natural growth patterns of plants and fungi. Plant seeds or fungal spores are first cultivated on nanoparticle-based culture media. Subsequent heat treatment removes the biological species while sintering the surrounding compound into a solidified chip with replica root/hyphal architectures as open microchannels. A diverse range of architectures, including the hierarchical branching of plant roots and the intricate networks formed by fungal hyphae, can be faithfully replicated. The resultant glass microvascular networks exhibit high chemical and thermal stability, enabling applications under harsh conditions. Fluid flow experiments validate the functionalities of the fabricated channels. By co-cultivating plants and fungi, hierarchical multi-scale architectures mimicking natural vascular systems are achieved. This bioinspired manufacturing technique leverages autonomous biological growth for architectural optimization, offering a complementary approach to existing microfabrication methods. The transparent nature of the glass chips allows for direct optical inspection, potentially facilitating integration with imaging components. This versatile platform holds promise for various engineering applications, such as microreactors, heat exchangers, and advanced filtration systems.
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Vidrio , Hifa , Raíces de Plantas , Vidrio/química , Raíces de Plantas/microbiología , Hifa/crecimiento & desarrollo , Ingeniería de Tejidos/métodos , Hongos/metabolismoRESUMEN
During opportunistic pathogenic episodes, Candida albicans employs classical strategies such as the yeast-to-hyphae transition and immunogenic masking. In this issue of Cell Host & Microbe, Luo et al. unveil that the effector protein Cmi1 can be translocated into host cells and targets TBK1, thereby negatively regulating the host's antifungal immune responses.
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Candida albicans , Candidiasis , Interacciones Huésped-Patógeno , Evasión Inmune , Candida albicans/inmunología , Humanos , Interacciones Huésped-Patógeno/inmunología , Candidiasis/inmunología , Candidiasis/microbiología , Proteínas Fúngicas/inmunología , Proteínas Fúngicas/metabolismo , Proteínas Serina-Treonina Quinasas/metabolismo , Animales , Hifa/inmunologíaRESUMEN
The hyphal surface of cells of filamentous fungi is covered with cell wall, which is mainly composed of polysaccharides. Since the cell wall is the first structure to come in contact with the infection host, the environment, and the fungus itself, the elucidation of the cell wall structure and biogenesis is essential for understanding fungal ecology. Among filamentous fungi, the genus Aspergillus is an important group in the industrial, food, and medical fields. It is known that Aspergillus species form hyphal pellets in shake liquid culture. The authors previously found the role of α-1,3-glucan in hyphal aggregation in Aspergillus species. In addition, extracellular polysaccharide galactosaminogalactan contributed to hyphal aggregation as well, and dual disruption of biosynthesis genes of α-1,3-glucan and galactosaminogalactan resulted in complete hyphal dispersion in shake liquid culture. The characteristic of mycelia to form pellets under liquid culture conditions was the main reason why the growth measurement methods used for unicellular organisms could not be applied. We reported that hyphal growth of the dual disruption mutant could be measured by optical density. A real-time plate reader could be used to determine the growth curve of the mycelial growth of the dual disruption mutant. This measurement approach not only provides basic microbiological insights in filamentous fungi, but also has the potential to be applied to high-throughput screening of anti-Aspergillus drugs.
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Aspergillus , Pared Celular , Hifa , Hifa/crecimiento & desarrollo , Aspergillus/genética , Glucanos/metabolismo , Microbiología Industrial/métodosRESUMEN
Candida albicans has been listed in the critical priority group by the WHO in 2022 depending upon its contribution in invasive candidiasis and increased resistance to conventional drugs. Drug repurposing offers an efficient, rapid, and cost-effective solution to develop alternative therapeutics against pathogenic microbes. Alexidine dihydrochloride (AXD) and hexachlorophene (HCP) are FDA approved anti-cancer and anti-septic drugs, respectively. In this study, we have shown antifungal properties of AXD and HCP against the wild type (reference strain) and clinical isolates of C. albicans. The minimum inhibitory concentrations (MIC50) of AXD and HCP against C. albicans ranged between 0.34 and 0.69 µM and 19.66-24.58 µM, respectively. The biofilm inhibitory and eradication concentration of AXD was reported comparatively lower than that of HCP for the strains used in the study. Further investigations were performed to understand the antifungal mode of action of AXD and HCP by studying virulence features like cell surface hydrophobicity, adhesion, and yeast to hyphae transition, were also reduced upon exposure to both the drugs. Ergosterol content in cell membrane of the wild type strain was upregulated on exposure to AXD and HCP both. Biochemical analyses of the exposed biofilm indicated reduced contents of carbohydrate, protein, and e-DNA in the extracellular matrix of the biofilm when compared to the untreated control biofilm. AXD exposure downregulated activity of tissue invading enzyme, phospholipase in the reference strain. In wild type strain, ROS level, and activities of antioxidant enzymes were found elevated upon exposure to both drugs. FESEM analysis of the drug treated biofilms revealed degraded biofilm. This study has indicated mode of action of antifungal potential of alexidine dihydrochloride and hexachlorophene in C. albicans.
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Antifúngicos , Biopelículas , Candida albicans , Reposicionamiento de Medicamentos , Pruebas de Sensibilidad Microbiana , Candida albicans/efectos de los fármacos , Candida albicans/genética , Antifúngicos/farmacología , Biopelículas/efectos de los fármacos , Humanos , Amidinas/farmacología , Hifa/efectos de los fármacos , Hifa/crecimiento & desarrollo , Ergosterol/metabolismo , Candidiasis/tratamiento farmacológico , Candidiasis/microbiología , Virulencia/efectos de los fármacos , BiguanidasRESUMEN
BACKGROUND: The incidence of invasive fungal diseases (IFDs), represented by Candida albicans infection, is increasing year by year. However, clinically available antifungal drugs are very limited and encounter challenges such as limited efficacy, drug resistance, high toxicity, and exorbitant cost. Therefore, there is an urgent need for new antifungal drugs. PURPOSE: This study aims to find new antifungal compounds from plants, preferably those with good activity and low toxicity, and reveal their antifungal targets. METHODS: In vitro antifungal activities of compounds were investigated using broth microdilution method, spot assay, hyphal growth assay and biofilm formation assay. Synergistic effects were assessed using broth microdilution checkerboard technique. In vivo antifungal activities were evaluated using Galleria mellonella and murine candidiasis models. Cytotoxicity of compounds was investigated using Cell Counting Kit-8 (CCK-8). Discovery and validation of antifungal targets of compounds were conducted by using monoallelic knockout library of C. albicans, haploinsufficiency profiling (HIP), thermal shift assay (TSA), enzyme inhibitory effect assay, molecular docking, and in vitro and in vivo antifungal studies. RESULTS: 814 plant products were screened, among which petroselinic acid (PeAc) was found as an antifungal molecule. As a rare fatty acid isolated from coriander (Coriandrum sativum), carrot (Daucus carota) and other plants of the Apiaceae family, PeAc had not previously been found to have antifungal effects. In this study, PeAc was revealed to inhibit the growth of various pathogenic fungi, exhibited synergistic effects with fluconazole (FLC), inhibited the formation of C. albicans hyphae and biofilms, and showed antifungal effects in vivo. PeAc was less toxic to mammalian cells. Fructose-1,6-bisphosphate aldolase (Fba1p) was identified as a target of PeAc by using HIP, TSA, enzyme inhibitory effect assay and molecular docking methods. PeAc exerted antifungal effects more effectively on fba1Δ/FBA1 than wild-type (WT) strain both in vitro and in vivo. CONCLUSIONS: PeAc is an effective and low toxic antifungal compound. The target of PeAc is Fba1p. Fba1p is a promising target for antifungal drug development.
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Antifúngicos , Candida albicans , Candidiasis , Fructosa-Bifosfato Aldolasa , Pruebas de Sensibilidad Microbiana , Simulación del Acoplamiento Molecular , Antifúngicos/farmacología , Antifúngicos/química , Animales , Candida albicans/efectos de los fármacos , Ratones , Fructosa-Bifosfato Aldolasa/metabolismo , Candidiasis/tratamiento farmacológico , Biopelículas/efectos de los fármacos , Sinergismo Farmacológico , Hifa/efectos de los fármacos , Petroselinum/química , Mariposas Nocturnas/efectos de los fármacos , Modelos Animales de EnfermedadRESUMEN
Glucocorticoids are a major class of therapeutic anti-inflammatory and immunosuppressive drugs prescribed to patients with inflammatory diseases, to avoid transplant rejection, and as part of cancer chemotherapy. However, exposure to these drugs increases the risk of opportunistic infections such as with the fungus Aspergillus fumigatus, which causes mortality in >50% of infected patients. The mechanisms by which glucocorticoids increase susceptibility to A. fumigatus are poorly understood. In this article, we used a zebrafish larva Aspergillus infection model to identify innate immune mechanisms altered by glucocorticoid treatment. Infected larvae exposed to dexamethasone succumb to infection at a significantly higher rate than control larvae. However, both macrophages and neutrophils are still recruited to the site of infection, and dexamethasone treatment does not significantly affect fungal spore killing. Instead, the primary effect of dexamethasone manifests later in infection with treated larvae exhibiting increased invasive hyphal growth. In line with this, dexamethasone predominantly inhibits neutrophil function rather than macrophage function. Dexamethasone-induced mortality also depends on the glucocorticoid receptor. Dexamethasone partially suppresses NF-κB activation at the infection site by inducing the transcription of IκB via the glucocorticoid receptor. Independent CRISPR/Cas9 targeting of IKKγ to prevent NF-κB activation also increases invasive A. fumigatus growth and larval mortality. However, dexamethasone treatment of IKKγ crispant larvae further increases invasive hyphal growth and host mortality, suggesting that dexamethasone may suppress other pathways in addition to NF-κB to promote host susceptibility. Collectively, we find that dexamethasone acts through the glucocorticoid receptor to suppress NF-κB-mediated neutrophil control of A. fumigatus hyphae in zebrafish larvae.
Asunto(s)
Aspergilosis , Aspergillus fumigatus , Dexametasona , Glucocorticoides , FN-kappa B , Neutrófilos , Pez Cebra , Animales , Aspergillus fumigatus/inmunología , Neutrófilos/inmunología , Neutrófilos/efectos de los fármacos , Pez Cebra/inmunología , FN-kappa B/metabolismo , Aspergilosis/inmunología , Dexametasona/farmacología , Glucocorticoides/farmacología , Hifa/inmunología , Hifa/crecimiento & desarrollo , Hifa/efectos de los fármacos , Larva/inmunología , Larva/microbiología , Receptores de Glucocorticoides/metabolismo , Macrófagos/inmunología , Macrófagos/efectos de los fármacos , Modelos Animales de Enfermedad , Inmunidad Innata/efectos de los fármacos , HumanosRESUMEN
Candida albicans is a common opportunistic fungus in humans, whose morphological switch between yeast and hyphae forms represents a key virulence trait. Developing strategies to inhibit C. albicans hyphal growth may provide insights into designs of novel antivirulent therapeutics. Importantly, the gut commensal bacterium, Enterococcus faecalis, secretes a bacteriocin EntV which has potent antivirulent and antifungal effects against C. albicans in infection models; however, hampered by the challenges to access large quantities of bioactive EntV, the detailed understanding of its mechanisms on C. albicans has remained elusive. In this work, we biochemically reconstituted the proteolytic cleavage reaction to obtain recombinant EntV88-His6 on a large preparative scale, providing facile access to the C-terminal EntV construct. Under in vitro C. albicans hyphal assay with specific inducers, we demonstrated that EntV88-His6 exhibits potent bioactivity against GlcNAc-triggered hyphal growth. Moreover, with fluorescent FITC-EntV88-His6, we revealed that EntV88-His6 enters C. albicans via endocytosis and perturbs the proper localization of the polarisome scaffolding Spa2 protein. Our findings provide important clues on EntV's mechanism of action. Surprisingly, we showed that EntV88-His6 does not affect C. albicans yeast cell growth but potently exerts cytotoxicity against C. albicans under hyphal-inducing conditions in vitro. The combination of EntV88-His6 and GlcNAc displays rapid killing of C. albicans, rendering it a promising antivirulent and antifungal agent.
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Antifúngicos , Candida albicans , Enterococcus faecalis , Hifa , Candida albicans/efectos de los fármacos , Enterococcus faecalis/efectos de los fármacos , Antifúngicos/farmacología , Antifúngicos/química , Hifa/efectos de los fármacos , Hifa/crecimiento & desarrollo , Proteínas Recombinantes/farmacología , Proteínas Recombinantes/genética , Bacteriocinas/farmacología , Bacteriocinas/química , Pruebas de Sensibilidad Microbiana , Humanos , Proteínas Fúngicas/genética , Proteínas Fúngicas/metabolismo , Proteínas Fúngicas/química , Endocitosis/efectos de los fármacosRESUMEN
Apple Valsa canker disease, caused by Valsa mali Miyabe et Yamada, severely endangers the healthy growth of apple trees. The Som1, located downstream of the cyclic AMP-dependent protein kinase A (cAMP-PKA) pathway, plays crucial roles in the growth, development, morphological differentiation, and virulence of filamentous fungi. In this study, we identify and functionally characterize VmSom1, a homolog of Som1, in Valsa mali. The VmSom1 gene is located on chromosome 12, encoding an 824 amino acid protein. Phylogenetic analysis reveals VmSom1 as a fungal Som1 homolog. The VmSom1 deletion mutants exhibit slower growth rates and fail to produce pycnidia. Additionally, their hyphal growth is significantly inhibited on media containing Calcofluor White, Congo Red, NaCl, and sorbitol. The growth rate of VmSom1 deletion mutants is reduced on maltose, lactose, sucrose and fructose media but increases on glucose medium. Moreover, the mycelial growth rate of the VmSom1 deletion mutant is significantly lower than that of the wild-type strain in peptone, NH4SO4, NaNO3, and no nitrogen. Notably, the distances between the septa increase, and chitin concentration shifts to the hyphal tip in the VmSom1 deletion mutant. Furthermore, compared with the wild-type strain, the VmSom1 deletion mutant exhibits fewer diseased spots on apple fruit and branches. Overall, our findings demonstrate that VmSom1 is involved in regulating the growth and development, colony surface hydrophobicity, osmotic stress, cell wall integrity maintenance, carbon and nitrogen source utilization, septa formation, and virulence of V. mali.
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Pared Celular , Proteínas Fúngicas , Malus , Filogenia , Enfermedades de las Plantas , Pared Celular/metabolismo , Virulencia , Malus/microbiología , Enfermedades de las Plantas/microbiología , Proteínas Fúngicas/genética , Proteínas Fúngicas/metabolismo , Hifa/crecimiento & desarrollo , Hifa/genética , Hifa/metabolismo , Eliminación de Gen , Regulación Fúngica de la Expresión Génica , Ascomicetos/genética , Ascomicetos/patogenicidad , Ascomicetos/crecimiento & desarrollo , Ascomicetos/metabolismoRESUMEN
Candida albicans is an opportunistic yeast accounting for about 50-90 % of all cases of candidiasis in humans, ranging from superficial to systemic potentially life-threatening infections. The presence of several virulence factors, including biofilm, hyphal transition, and proteolytic enzymes production, worsens the fungal infections burden on healthcare system resources. Hence, developing new bioactive compounds with antifungal activity is a pressing urgence for the scientific community. In this perspective, we evaluated the anti-Candida potential of the N-Nitroso-N-phenylhydroxylamine ammonium salt (cupferron) against standard and clinical C. albicans strains. Firstly, the in vitro cytotoxicity of cupferron was checked in the range 400-12.5 µg/mL against human microglial cells (HMC-3). Secondly, its antifungal spectrum was explored via disk diffusion test, broth-microdilution method, and time-killing curve analysis, validating the obtained results through scanning electron microscopy (SEM) observations. Additionally, we evaluated the cupferron impact on the main virulence determinants of Candida albicans. At non-toxic concentrations (100-12.5 µg/mL), the compound exerted interesting anti-Candida activity, registering a minimum inhibitory concentration (MIC) between 50 and 100 µg/mL against the tested strains, with a fungistatic effect until 100 µg/mL. Furthermore, cupferron was able to counteract fungal virulence at MIC and sub-MIC values (50-12.5 µg/mL). These findings may propose cupferron as a new potential antifungal option for the treatment of Candida albicans infections.
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Antifúngicos , Biopelículas , Candida albicans , Pruebas de Sensibilidad Microbiana , Candida albicans/efectos de los fármacos , Antifúngicos/farmacología , Humanos , Biopelículas/efectos de los fármacos , Candidiasis/microbiología , Candidiasis/tratamiento farmacológico , Factores de Virulencia , Línea Celular , Hifa/efectos de los fármacos , Microscopía Electrónica de Rastreo , Virulencia/efectos de los fármacos , Proteínas Fúngicas/metabolismoRESUMEN
Candida albicans is the most common agent in human fungal infections; nevertheless, in the last decades, the closely related yeasts Candida dubliniensis and Candida africana have emerged as pathogens. The purpose of this study was to compare tobacco agar with another five agars prepared from plant extracts (Origanum vulgare, Rosmarinus officinalis, Solanum rudepannum, Solanum oblongifolium and Brugmansia arborea) on the differentiation of C. albicans complex. The hyphae and chlamyconidia formation and the color and margin of the colonies of 200 clinical isolates of C. albicans, C. dubliniensis and C. africana were evaluated. After seven days of incubation at 28 °C, Tobacco agar, S. rudepannum and B. arborea agars allowed the differentiation of 100 % C. dubliniensis. Additionally, 24% of C. africana isolates produced brownish colonies in the medium prepared from Rosmarinus officinalis (rosemary) extract. These results indicate that S. rudepannun, B. arborea and rosemary agar could be used as screening for the phenotypic differentiation between the species of C. albicans complex. Rosemary agar could be used to aid in the differentiation of C. albicans from C. africana. These culture media based on plants, could be used as simple and inexpensive screening methods in the phenotypic differentiation of C. dubliniensis and C. africana.
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Candida albicans , Medios de Cultivo , Extractos Vegetales , Candida albicans/aislamiento & purificación , Candida/clasificación , Candida/aislamiento & purificación , Agar , Humanos , HifaRESUMEN
P. umbellatus sclerotium is a traditional Chinese medicine that is widely utilized in China, Korea, Japan, and other countries due to its diverse medicinal activities, such as diuretic, antitumor, anticancer, and immune system enhancement effects. Conidia, which are common asexual spores in various fungi, are not universally present in Polyporus species. In this study, the asexual life cycle of P. umbellatus was elucidated. Conidia, i.e. arthorconidia, were produced by both dikaryotic and monokaryotic strains. In the dikaryotic strain, binucleate, uninucleate, and nuclei-free conidia were identified with proportions of 67.9 %, 12.4 %, and 19.7 %, respectively. Conversely, the monokaryotic strain did not produce binucleate conidia. This discrepancy suggests that binucleate spores are heterokaryons, while uninucleate spores are homokaryons. Clamp connections were observed in dikaryotic hyphae, but were absent in monokaryotic hyphae. Monokaryotic strains were obtained from conidia of the dikaryotic strain. Additionally, mating types were determined through pairing tests, and successful crossbreeding occurred between monokaryotic strains derived from conidia and basidiospores from different strains. This study introduced the first crossbreeding strategy for P. umbellatus.
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Polyporus , Esporas Fúngicas , Esporas Fúngicas/crecimiento & desarrollo , Polyporus/crecimiento & desarrollo , Polyporus/metabolismo , Núcleo Celular , Reproducción Asexuada , Hifa/crecimiento & desarrollo , Estadios del Ciclo de Vida , Genes del Tipo Sexual de los HongosRESUMEN
The development of new effective antifungal agents is essential to combat fungal infections. Tetrahydrocarbazole has been exploited as a promising skeleton against various pathogenic microorganisms and is used to search for novel active antifungal compounds. In this study, a library composed of small tetrahydrocarbazole compounds was screened, and a potent antifungal agent, CAR-8, was identified with a minimum inhibitory concentration of 2-4 µg/mL against Candida albicans. CAR-8 showed strong fungicidal activities and killed almost all C. albicans within 3 h at a concentration of 16 µg/mL. At concentrations of 2 and 8 µg/mL, CAR-8 significantly inhibited the formation of hyphae and biofilms. Moreover, CAR-8 at 10 and 20 mg/kg reduced the fungal load and improved the survival in the C. albicans infection model in the invertebrate Galleria mellonella. Transcriptome analysis revealed significant changes in the expression of genes associated with protein processing in the endoplasmic reticulum (ER), ER-associated degradation, and unfolded protein response (UPR), which suggested that CAR-8 treatment induced ER stress. Moreover, CAR-8 treatment resulted in various phenotypes similar to tunicamycin, a classical ER stress inducer. These included nonconventional splicing of HAC1 mRNA, the fragmented morphology of ER, the distribution changes of GFP-Snc1 in Saccharomyces cerevisiae, and cell apoptosis probably caused by ER stress. More importantly, the disruption of IRE1 or HAC1 increased the sensitivity of C. albicans to CAR-8, confirming that the UPR signaling pathway was critical for CAR-8 resistance. Overall, our study identifies a potent ER stress-induced antifungal compound that will help the discovery of new antifungal drugs.
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Antifúngicos , Candida albicans , Carbazoles , Estrés del Retículo Endoplásmico , Pruebas de Sensibilidad Microbiana , Antifúngicos/farmacología , Candida albicans/efectos de los fármacos , Estrés del Retículo Endoplásmico/efectos de los fármacos , Carbazoles/farmacología , Animales , Biopelículas/efectos de los fármacos , Candidiasis/microbiología , Candidiasis/tratamiento farmacológico , Respuesta de Proteína Desplegada/efectos de los fármacos , Hifa/efectos de los fármacosRESUMEN
Fleagrass, a herb known for its pleasant aroma, is widely used as a mosquito repellent, antibacterial agent, and for treating colds, reducing swelling, and alleviating pain. The antifungal effects of the essential oils of fleagrass and carvacrol against Candida albicans were investigated by evaluating the growth and the mycelial and biofilm development of C. albicans. Transmission electron microscopy was used to evaluate the integrity of the cell membrane and cell wall of C. albicans. Fleagrass exhibited high fungicidal activity against C. albicans at concentrations of 0.5% v/v (via the Ras1/cAMP/PKA pathway). Furthermore, transmission electron microscopy revealed damage to the cell wall and membrane after treatment with the essential oil, which was further confirmed by the increased levels of ß-1,3-glucan and chitin in the cell wall. This study showed that fleagrass exerts good fungicidal and hyphal growth inhibition activity against C. albicans by disrupting its cell wall, and thus, fleagrass may be a potential antifungal drug.
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Antifúngicos , Biopelículas , Candida albicans , Pared Celular , Pruebas de Sensibilidad Microbiana , Aceites Volátiles , Candida albicans/efectos de los fármacos , Pared Celular/efectos de los fármacos , Pared Celular/ultraestructura , Antifúngicos/farmacología , Biopelículas/efectos de los fármacos , Biopelículas/crecimiento & desarrollo , Aceites Volátiles/farmacología , Hifa/efectos de los fármacos , Hifa/crecimiento & desarrollo , Monoterpenos/farmacología , beta-Glucanos/metabolismo , beta-Glucanos/farmacología , Quitina/farmacología , Quitina/metabolismo , Microscopía Electrónica de Transmisión , Fabaceae/química , Fabaceae/microbiología , CimenosRESUMEN
Major Candida albicans virulence traits include its ability to make hyphae, to produce a biofilm, and to damage host cells. These traits depend upon expression of hypha-associated genes. A gene expression comparison among clinical isolates suggested that transcription factor Rme1, established by previous studies to be a positive regulator of chlamydospore formation, may also be a negative regulator of hypha-associated genes. Engineered RME1 overexpression supported this hypothesis, but no relevant rme1Δ/Δ mutant phenotype was detected. We reasoned that Rme1 may function within a specific regulatory pathway. This idea was supported by our finding that an rme1Δ/Δ mutation relieves the need for biofilm regulator Brg1 in biofilm formation. The impact of the rme1Δ/Δ mutation is most prominent under static or "biofilm-like" growth conditions. RNA sequencing (RNA-seq) of cells grown under biofilm-like conditions indicates that Brg1 activates hypha-associated genes indirectly via repression of RME1: hypha-associated gene expression levels are substantially reduced in a brg1Δ/Δ mutant and partially restored in a brg1Δ/Δ rme1Δ/Δ double mutant. An rme1Δ/Δ mutation does not simply bypass Brg1, because iron homeostasis genes depend upon Brg1 regardless of Rme1. Rme1 thus connects Brg1 to the targets relevant to hypha and biofilm formation under biofilm growth conditions.IMPORTANCECandida albicans is a major fungal pathogen of humans, and its ability to grow as a surface-associated biofilm on implanted devices is a common cause of infection. Here, we describe a new regulator of biofilm formation, RME1, whose activity is most prominent under biofilm-like growth conditions.
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Biopelículas , Candida albicans , Proteínas Fúngicas , Regulación Fúngica de la Expresión Génica , Hifa , Factores de Transcripción , Candida albicans/genética , Candida albicans/fisiología , Proteínas Fúngicas/genética , Proteínas Fúngicas/metabolismo , Hifa/genética , Hifa/crecimiento & desarrollo , Biopelículas/crecimiento & desarrollo , Factores de Transcripción/genética , Factores de Transcripción/metabolismo , ADN Helicasas/genética , ADN Helicasas/metabolismo , Virulencia/genética , MutaciónRESUMEN
Candida albicans is the most prevalent fungal pathogen associated with candidemia. Similar to other fungi, the complex life cycle of C. albicans has been challenging to study with high-resolution microscopy due to its small size. Here, we employed ultrastructure expansion microscopy (U-ExM) to directly visualise subcellular structures at high resolution in the yeast and during its transition to hyphal growth. N-hydroxysuccinimide (NHS)-ester pan-labelling in combination with immunofluorescence via snapshots of various mitotic stages provided a comprehensive map of nucleolar and mitochondrial segregation dynamics and enabled the resolution of the inner and outer plaque of spindle pole bodies (SPBs). Analyses of microtubules (MTs) and SPBs suggest that C. albicans displays a side-by-side SPB arrangement with a short mitotic spindle and longer astral MTs (aMTs) at the pre-anaphase stage. Modifications to the established U-ExM protocol enabled the expansion of six other human fungal pathogens, revealing that the side-by-side SPB configuration is a plausibly conserved feature shared by many fungal species. We highlight the power of U-ExM to investigate subcellular organisation at high resolution and low cost in poorly studied and medically relevant microbial pathogens.
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Hifa , Microtúbulos , Microtúbulos/ultraestructura , Microtúbulos/metabolismo , Hifa/ultraestructura , Hifa/crecimiento & desarrollo , Candida albicans/ultraestructura , Cuerpos Polares del Huso/metabolismo , Cuerpos Polares del Huso/ultraestructura , Saccharomycetales/ultraestructura , Mitocondrias/ultraestructura , Microscopía/métodos , HumanosRESUMEN
The antagonistic interplay between phosphorus (P) and zinc (Zn) in plants is well established. However, the molecular mechanisms mediating those interactions as influenced by arbuscular mycorrhizal (AM) symbiosis remain unclear. We investigated Zn concentrations, root AM symbiosis, and transcriptome profiles of maize roots grown under field conditions upon different P levels. We also validated genotype-dependent P-Zn uptake in selected genotypes from a MAGIC population and conducted mycorrhizal inoculation experiments using mycorrhizal-defective mutant pht1;6 to elucidate the significance of AM symbiosis in P-Zn antagonism. Finally, we assessed how P supply affects Zn transporters and Zn uptake in extraradical hyphae within a three-compartment system. Elevated P levels led to a significant reduction in maize Zn concentration across the population, correlating with a marked decline in AM symbiosis, thus elucidating the P-Zn antagonism. We also identified ZmPht1;6 is crucial for AM symbiosis and confirmed that P-Zn antagonistic uptake is dependent on AM symbiosis. Moreover, we found that high P suppressed the expression of the fungal RiZRT1 and RiZnT1 genes, potentially impacting hyphal Zn uptake. We conclude that high P exerts systemic regulation over root and AM hyphae-mediated Zn uptake in maize. These findings hold implications for breeding Zn deficiency-tolerant maize varieties.
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Regulación de la Expresión Génica de las Plantas , Micorrizas , Fósforo , Suelo , Simbiosis , Zea mays , Zinc , Zea mays/microbiología , Zea mays/metabolismo , Zea mays/genética , Micorrizas/fisiología , Zinc/metabolismo , Fósforo/metabolismo , Suelo/química , Transporte Biológico , Raíces de Plantas/microbiología , Raíces de Plantas/metabolismo , Proteínas de Plantas/metabolismo , Proteínas de Plantas/genética , Hifa , Genotipo , Mutación/genéticaRESUMEN
A range of fungal species showed variable abilities to colonize and penetrate a mortar substrate. Calcium biomineralization was a common feature with calcium-containing crystals deposited in the microenvironment or encrusting hyphae, regardless of the specific mortar composition. Several species caused significant damage to the mortar surface, exhibiting burrowing and penetration, surface etching, and biomineralization. In some cases, extensive biomineralization of hyphae, probably by carbonatization, resulted in the formation of crystalline tubes after hyphal degradation on mortar blocks, including those amended with Co or Sr carbonate. Ca was the only metal detected in the biomineralized formations with Co or Sr undetectable. Aspergillus niger, Stemphylium sp. and Paecilomyces sp. could penetrate mortar with differential responses depending on the porosity. Fluorescent staining of thin sections recorded penetration depths of â¼530 um for A. niger and â¼620 um for Stemphylium sp. Penetration depth varied inversely with porosity and greater penetration depths were achieved in mortar with a lower porosity (lower water/cement ratio). These results have provided further understanding of biodeteriorative fungal interactions with cementitious substrates that can clearly affect structural integrity. The potential significance of fungal colonization and such biodeteriorative phenomena should not be overlooked in built environment contexts, including radionuclide storage and surface decontamination.
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Materiales de Construcción , Hongos , Materiales de Construcción/microbiología , Hongos/metabolismo , Calcio/metabolismo , Hifa/metabolismo , Hifa/crecimiento & desarrolloRESUMEN
BACKGROUND: Alternaria alternata is the primary pathogen of potato leaf spot disease, resulting in significant potato yield losses globally. Endophytic microorganism-based biological control, especially using microorganisms from host plants, has emerged as a promising and eco-friendly approach for managing plant diseases. Therefore, this study aimed to isolate, identify and characterize the endophytic fungi from healthy potato leaves which had great antifungal activity to the potato leaf spot pathogen of A. alternata in vitro and in vivo. RESULTS: An endophytic fungal strain SD1-4 was isolated from healthy potato leaves and was identified as Talaromyces muroii through morphological and sequencing analysis. The strain SD1-4 exhibited potent antifungal activity against the potato leaf spot pathogen A. alternata Lill, with a hyphal inhibition rate of 69.19%. Microscopic and scanning electron microscope observations revealed that the strain SD1-4 grew parallel to, coiled around, shrunk and deformed the mycelia of A. alternata Lill. Additionally, the enzyme activities of chitinase and ß-1, 3-glucanase significantly increased in the hyphae of A. alternata Lill when co-cultured with the strain SD1-4, indicating severe impairment of the cell wall function of A. alternata Lill. Furthermore, the mycelial growth and conidial germination of A. alternata Lill were significantly suppressed by the aseptic filtrate of the strain SD1-4, with inhibition rates of 79.00% and 80.67%, respectively. Decrease of leaf spot disease index from 78.36 to 37.03 was also observed in potato plants treated with the strain SD1-4, along with the significantly increased plant growth characters including plant height, root length, fresh weight, dry weight, chlorophyll content and photosynthetic rate of potato seedlings. CONCLUSION: The endophyte fungus of T. muroii SD1-4 isolated from healthy potato leaves in the present study showed high biocontrol potential against potato leaf spot disease caused by A. alternata via direct parasitism or antifungal metabolites, and had positive roles in promoting potato plant growth.
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Alternaria , Endófitos , Enfermedades de las Plantas , Hojas de la Planta , Solanum tuberosum , Talaromyces , Alternaria/crecimiento & desarrollo , Alternaria/fisiología , Enfermedades de las Plantas/microbiología , Enfermedades de las Plantas/prevención & control , Solanum tuberosum/microbiología , Talaromyces/genética , Talaromyces/crecimiento & desarrollo , Endófitos/fisiología , Endófitos/aislamiento & purificación , Endófitos/genética , Hojas de la Planta/microbiología , Hifa/crecimiento & desarrollo , Antibiosis , Quitinasas/metabolismo , Agentes de Control Biológico , Control Biológico de Vectores/métodosRESUMEN
The stereotypical tip growth of filamentous fungi supports their lifestyles and functions. It relies on the polarized remodeling and expansion of a protective elastic cell wall (CW) driven by large cytoplasmic turgor pressure. Remarkably, hyphal filament diameters and cell elongation rates can vary extensively among different fungi. To date, however, how fungal cell mechanics may be adapted to support these morphological diversities while ensuring surface integrity remains unknown. Here, we combined super-resolution imaging and deflation assays to measure local CW thickness, elasticity and turgor in a set of fungal species spread on the evolutionary tree that spans a large range in cell size and growth speeds. While CW elasticity exhibited dispersed values, presumably reflecting differences in CW composition, both thickness and turgor scaled in dose-dependence with cell diameter and growth speeds. Notably, larger cells exhibited thinner lateral CWs, and faster cells thinner apical CWs. Counterintuitively, turgor pressure was also inversely scaled with cell diameter and tip growth speed, challenging the idea that turgor is the primary factor dictating tip elongation rates. We propose that fast-growing cells with rapid CW turnover have evolved strategies based on a less turgid cytoplasm and thin walls to safeguard surface integrity and survival.