Search Results (385)

This study investigated the molecular epidemiological characteristics of Cryptococcus neoformans (C. neoformans) isolates from AIDS patients with cryptococcal meningitis (CM) in southern China and examined their associations with clinical features and outcomes. A total of 100 clinical isolates were identified by MALDI-TOF MS and genotyped by multilocus sequence typing (MLST). Antifungal susceptibility to five agents was assessed using the FUNGUS 3 system. Baseline demographic, clinical manifestations, radiological, and laboratory data were collected from the corresponding 100 patients, and outcomes were evaluated at weeks 4, 12, 24, and 48. Seven sequence types (STs) were identified: ST5 (83/100, 83.0%), ST4 (5/100, 5.0%), ST31 (3/100, 3.0%), ST43 (1/100, 1.0%), ST93 (4/100, 4.0%), ST395 (1/100, 1.0%), and a presumptive novel ST685 (3/100, 3.0%). Most patients were male (80.0%), and headache was the most common symptom (85.0%). Susceptibility rates for 5-flucytosine, amphotericin B, fluconazole, itraconazole, and voriconazole were 98.9% (94/95), 71.9% (69/96), 82.3% (79/96), 59.4% (41/69), and 86.8% (59/68), respectively. Cumulative mortality reached 16%, 33%, 37%, and 39% at weeks 4, 12, 24, and 48. No significant differences were observed between 83 patients infected with ST5 and 17 patients with non-ST5 in clinical presentations or antifungal susceptibility. However, patients infected with ST5 exhibited consistently better survival rates across all time points; the 12-week non-survival rates were highest for patients infected with ST93 and ST395. Accordingly, ST5 is the dominant sequence type of C. neoformans in HIV-associated CM in southern China; meanwhile, non-ST5 types could have worse prognosis, indicating ST sequence typing may act as a prognostic biomarker in AIDS patients with CM. Full article

Cryptococcosis, caused by Cryptococcus neoformans, remains a major cause of mortality in immunocompromised patients, with treatment increasingly limited by resistance and toxicity associated with Amphotericin B (Amp B). In this study, methylglyoxal (MG) was evaluated as a virulence-targeted antifungal strategy, with emphasis on its liposomal delivery. MG exhibited superior antifungal activity as compared to Amp B, demonstrating lower MIC values and significantly enhanced inhibition of biofilm formation and laccase activity, key determinants of cryptococcal pathogenicity. Notably, MG showed potent intracellular antifungal activity within macrophages, where C. neoformans persists. Liposomal MG (Lip-MG) markedly reduced macrophage-associated fungal burden under the tested conditions, markedly outperforming both free MG and Amp B formulations. In a leukopenic mouse model of systemic infection, liposomal MG significantly improved survival (up to ~70%) and reduced pulmonary fungal burden as compared to Amp B, which showed limited therapeutic benefit. Importantly, MG-based formulations exhibited a favorable safety profile, with significantly lower nephrotoxicity than Amp B. Collectively, these findings demonstrate that Lip-MG acts through a dual virulence-targeted activity mechanism while effectively eliminating intracellular infection. This dual action, combined with improved safety, highlights MG-based nanotherapy as a promising and translational alternative for the treatment of drug-resistant cryptococcosis. Full article

Fucoidan is a sulfated polysaccharide derived from brown seaweed, reported to possess diverse biological activities that make it a molecule of great interest for nutraceutical and biomedical applications. A significant challenge to its wider implementation is a lack of understanding of the relationship between fucoidan’s structural and chemical characteristics with its biological activity. So far, approaches to identifying these relationships have been limited to qualitative comparisons of chemical and biological datasets or through chemically modified fucoidans. This work aimed to apply a formal methodology to elucidate potential relationships worthy of further exploration. The biological activity of commercial fucoidan extracts was assessed after detailed chemical characterization. The extracts exhibited multiple bioactivities, notably antioxidant activity, antiviral activity against Nipah virus, antifungal activity against Candida dubliensis and prebiotic effects on Lactobacillus casei, with no antifungal activity against Candida albicans, Candida auris and Cryptococcus neoformans, nor antibacterial effects against Klebsiella pneumoniae. Correlation analysis of biological activity and extract chemical characterization data identified several potential key quality attributes. Other than high fucose content, high sulfate content is identified as potentially important for antioxidant, antiviral, antifungal, and prebiotic activities. This work addressed the literature’s debate regarding the optimal molecular weight for bioactivity, suggesting that it depends on the specific microbe to which a fucoidan extract is applied. This study demonstrated that a formalized comparative approach, linking chemical and structural data with biological activity, can effectively identify important characteristics of fucoidan for a specific bioactivity. Future work will focus on expanding this approach by assessing the bioactivity of a wider array of chemically characterized fucoidan extracts. Additionally, extracts possessing identified quality attributes should be produced and employed in mechanistic bioactive studies to further validate the correlations drawn in this work. Full article

Background/Objectives: Skin candidiasis is a key contributor to chronic, non-healing wounds, largely due to persistent microbial infections. Candida species can colonize the skin, form protective biofilms, and interfere with enzyme activity, leading to extracellular matrix degradation, changes in pigmentation, and impaired wound healing. The rising prevalence of antifungal resistance challenges its management, underscoring the need for more effective antifungal therapies. Therefore, this study aimed to assess the antifungal effects and wound-healing potential of essential oils (EOs) from Ferulago spp. Methods: The antifungal activity of the EOs from five Ferulago species was evaluated against Candida spp. and Cryptococcus neoformans. The most active EOs were further investigated for their effects on C. albicans virulence factors, including germ tube formation, as well as biofilm formation and disruption. These effects were assessed using microscopic observation, XTT reduction assay, and crystal violet and safranin stainings. The wound-healing potential of the EOs was evaluated using the scratch-wound assay on fibroblasts and keratinocytes. Additionally, the effect on tyrosinase and elastase activity, was also investigated. Results:F. silaifolia and F. cassia essential oils showed fungicidal activity against Candida spp. and Cryptococcus neoformans. F. silaifolia displayed greater potency, with lower MIC and MLC values. Both oils inhibited key C. albicans virulence factors at sub-MIC concentrations. F. silaifolia EO was more effective in preventing biofilm formation whereas F. cassia EO showed notable tyrosinase inhibitory effect. Conclusions: These findings align with traditional uses and suggest that F. silaifolia and F. cassia EOs exhibit antifungal activity alongside properties associated with wound healing, supporting their potential as topical antifungal agents and thereby justifying further investigation. Full article

In this study, we developed a multiplex one-tube nested real-time fluorescent quantitative PCR (mONRT-PCR) assay integrated with a portable, fully automated nucleic acid point-of-care testing (POCT) platform for the detection of Haemophilus influenzae (H. influenzae), Listeria monocytogenes (L. monocytogenes), and Cryptococcus neoformans (C. neoformans) in cerebrospinal fluid (CSF). The assay enables nested amplification within a closed system using conventional primers and probes, thereby reducing operational complexity and minimizing contamination risk. Analytical evaluation demonstrated limits of detection of 10⁰ copies/μL for H. influenzae and L. monocytogenes, and 10¹ copies/μL for C. neoformans using recombinant plasmids, as well as 10⁻⁷ to 10⁻⁶ ng/μL using genomic DNA. No cross-reactivity was observed when tested against a panel of 17 common non-target microorganisms encountered in clinical microbiology laboratories. In simulated CSF samples, the assay maintained detectable amplification at low pathogen concentrations. When implemented on the POCT platform, detection limits reached 5, 10, and 50 CFU/mL for the three pathogens, respectively. Clinical evaluation using 43 CSF samples showed almost perfect agreement with conventional qPCR (κ = 0.861, p < 0.001). Notably, additional C. neoformans detections were observed by mONRT-PCR-POCT compared with qPCR, suggesting improved sensitivity under clinical conditions. The assay yielded results within approximately 1 h and 47 min. These findings indicate that the proposed assay provides a rapid, sensitive, and integrated approach for meningitis pathogen detection, while maintaining a practical balance between analytical performance and operational simplicity. Further validation in larger cohorts is warranted. Full article

Cryptococcosis is a severe systemic mycosis affecting humans and animals, caused primarily by members of the Cryptococcus neoformans/Cryptococcus gattii species complex. In cats, it is the most common systemic fungal infection and may present with non-specific signs involving the upper respiratory tract, skin, lymph nodes, eyes, or the central nervous system. This study presents two feline cases of cryptococcosis diagnosed by cytological examination and provides an updated literature review. Fine-needle aspiration biopsies were performed in two cats with chronic nasal swelling and submandibular enlargement. Cytological smears stained with hematoxylin and eosin revealed spherical to oval yeast-like organisms with a characteristic thick, non-staining capsule, narrow-based budding, and absence of pseudohyphae, consistent with Cryptococcus spp. Based on cytological findings, both patients were treated with oral itraconazole, resulting in favorable clinical outcomes. A limitation of this study is the lack of mycological culture or molecular confirmation, owing to the owners’ refusal of further diagnostic testing. These cases highlight the diagnostic value of cytology as a rapid tool for differentiating fungal infections from neoplastic processes. Early diagnosis and antifungal therapy are crucial for successful management. From a One Health perspective, feline cryptococcosis may indicate shared environmental exposure risks relevant to both animal and human health. Full article

Cryptococcus neoformans is a major fungal pathogen responsible for life-threatening meningitis, especially in immunocompromised individuals. Although the gut–lung axis is known to regulate immune responses in respiratory infections, its role in cryptococcosis remains unclear. This study aimed to define the dynamic changes in the gut and lung microbiota and their relationship with host immunity during C. neoformans infection. Using a mouse model, we found that pulmonary infection induced significant dysbiosis in both the lung and gut microbiota, marked by decreased beneficial commensals and increased opportunistic pathogens. Integrated analysis showed these microbial shifts were closely associated with distinct immune responses: lung dysbiosis correlated with a strong IL-17-mediated pulmonary inflammatory response, while gut dysbiosis was linked to systemic immune activation in the spleen. Functional metagenomic prediction further revealed widespread disruption in microbial metabolic pathways, including energy metabolism and biosynthesis, in both sites. Importantly, a positive correlation was observed between lung and gut dysbiosis, indicating an interconnected gut–lung axis during cryptococcosis. These findings demonstrate that C. neoformans infection causes coordinated disruptions in microbiota and immunity across the gut–lung axis, underscoring the microbiome as a critical modulator of host response and suggesting potential avenues for microbiome-targeted therapies. Full article

In 2022, the World Health Organization (WHO) released a list of four fungi identified as the most medically important global pathogens, resulting in Cryptococcus neoformans, Candidozyma auris (formerly Candida auris), Aspergillus fumigatus and Candida albicans being classified as the critical priority fungi. The purpose of this list is to encourage the prioritization of fungal research and public policies to strengthen its control and combat fungal diseases. Among the criteria used in the analysis by the WHO to determine these critical threat pathogens were numbers of deaths; annual incidence; current global distribution; trends in the last 10 years; hospitalization; complications and sequelae; preventability; access to diagnostic tests; evidence-based treatments; and antifungal resistance. Difficulties in treatment, including due to antifungal resistance, are a major factor in the morbidity and mortality of these fungi. The fungal cell wall plays a fundamental role in maintaining cellular architecture and contributing to fungal survival. Thus, new approaches targeting the cell wall have been and are being developed. This review article aims to bring together studies from the last ten years focusing on the development of new treatment alternatives targeting the cell walls of the four critical priority fungi and discussing their potential for combating these deadly fungi of worldwide clinical importance. Full article

The World Health Organization WHO considers fungal infections as a significant global risk that necessitates the development of new therapies. The arsenal of antifungals is limited, and the eukaryotic organization of fungi makes it difficult to find selective antifungal targets. In the search for potential targets for the design of new antifungals, the Stress-Activated Protein Kinase (SAPKs) pathways, and specifically, the two-component system, could be a plausible option since this upstream signaling system is absent in metazoans. SAPK pathways are involved in the response and adaptation to different environmental conditions. In pathogenic fungi, these signaling pathways are crucial for virulence, and some of them become activated in response to certain antifungals. Although further experimental evidence is required on the role of SAPKs in antifungal signaling and resistance, the possibility of impairing SAPK signaling by tagging the two-component system can be considered a useful strategy for implementing future antifungal therapies. In particular, the beneficial value of SAPK modulators combined with antifungal drugs should be a preferred line of research. In this review, we focused on the connection between the SAPK pathways and antifungal signaling in the four fungal priority pathogens, Cryptococcus neoformans, Candidozyma (formerly Candida) auris, Aspergillus fumigatus, and Candida albicans, defined by the WHO. Full article

The cyclic adamantane framework possesses unique properties such as bulkiness, symmetry, and high lipophilicity. Research aimed at discovering new pharmaceutical agents within the adamantane series continues. In the present work, a targeted modification was carried out to combine two pharmacophore fragments—adamantane and piperidine—within a single molecule. Based on a series of N-substituted piperidin-4-ones, the corresponding secondary alcohols were obtained by reduction with sodium borohydride in isopropanol and subsequent acylation of these alcohols with adamantane carbonyl chloride yielded the corresponding adamantane-carboxylate esters. The structure of the synthesized compounds was studied by NMR methods, including COSY (¹H-¹H), HMQC (¹H-¹³C) and HMBC (¹H-¹³C) techniques. The values of chemical shifts, multiplicities, and integrated intensities of ¹H and ¹³C signals in one-dimensional NMR spectra were determined. The results of COSY (¹H-¹H), HMQC (¹H-¹³C), and HMBC (¹H-¹³C) revealed homo- and heteronuclear interactions, confirming the structure of the studied compounds. The cytotoxic activities of the synthesized compounds were studied. It was found that the synthesized substituted piperidines bearing an adamantane fragment exhibit in vitro antimicrobial and antifungal activity against museum microbial strains (Escherichia coli ATCC 8739, Staphylococcus aureus ATCC 6538-P, Candida albicans ATCC 10231, Cryptococcus neoformans) and demonstrate significant advantages over the reference drugs used in clinical practice, such as fluconazole and ampicillin. These compounds are therefore recommended for further in-depth studies. Full article

Since 1997, a laboratory-based survey on cryptococcosis has been conducted in Colombia. We present the results for the period 2017–2024. A total of 891 surveys were received. The overall incidence was 0.22 cases per 100,000 people. Among those living with HIV, the incidence was 38, and among HIV-negative people, it was 0.08. Cryptococcosis demonstrated a higher prevalence among men than women (3.2:1). Among patients living with Human Immunodeficiency Virus (HIV), the condition primarily affected younger adults (26–40 years). In contrast, among HIV-negative people, it was mostly observed in older adults (≥60 years). HIV infection was the most significant risk factor (63%), but another cause of immunosuppression was identified in 21.2% cases. Neurocryptococcosis was the most common form of presentation (62.2%), followed by disseminated cryptococcosis (31.1%). The diagnosis was confirmed by culture in 99.4% of patients; the most important sample was cerebrospinal fluid (67.3%), followed by blood (35.4%). Cryptococcus neoformans was identified in 93.1% of cases, and Cryptococcus gatti in 6.9%. Predominant molecular patterns were VNI (92.4%) and VGII (45.3%). The epidemiology of cryptococcosis in Colombia is changing, with a progressive decrease in HIV coinfection and an increase in other immunosuppressive conditions in older people. This study highlights the importance of cryptococcosis in Colombia and the need to report it in order to improve knowledge and thereby promote the quality of diagnosis and the opportunity for more effective treatment. Full article

Ellagic acid (EA), a naturally occurring phenolic compound, has garnered significant interest as a potential antifungal agent owing to increasing fungal resistance and a scarce therapeutic pipeline. This review consolidates the evidence of the broad-spectrum activity of EA against critical priority pathogens, including Candida auris and Cryptococcus neoformans. We highlight its multi-target mechanisms of action, such as the impairment of cell wall integrity and plasma membrane disruption resulting from the inhibition of ergosterol biosynthesis, and inhibition of key enzymes, such as laccase. In addition to its direct growth-inhibitory effects, EA exhibits antivirulence properties, reducing biofilm formation and hyphal morphogenesis. Notably, it demonstrates synergistic potential with conventional antifungals, such as fluconazole, enhancing efficacy and potentially hindering the emergence of resistance. Although its poor solubility and bioavailability pose therapeutic challenges, advanced formulations such as liposomal systems show promise for improving its delivery. We conclude that EA is a promising candidate for developing new antifungal strategies, particularly as a synergistic agent or in nanoformulations, warranting further investigation to translate its potential into clinical practice. Full article

Cryptococcus neoformans is a pathogenic yeast and the leading cause of cryptococcosis in humans. The calcium-calcineurin signaling pathway plays a central role in stress adaptation and virulence. To identify the uncharacterized regulators of fungal adaptation, we utilized an integrative systems biology approach, combining differential gene expression and network analysis using transcriptomic data from three key components of the calcium-calcineurin pathway (Cna1, Crz1, and Pmc1). Our workflow identified the CNAG_00522 gene product, which we designated tricalbin 1 (TCB1) due to its conserved calcium and lipid-binding C2 domains. TCB1 expression was found to be regulated by both Cna1 and Pmc1. Network analyses positioned Tcb1 as a bottleneck linking general stress response and cellular processes. Further molecular characterization confirmed that TCB1 expression is temperature and calcium-responsive. Functional studies of the tcb1Δ mutant revealed an enlarged capsule, increased GXM shedding, and enhanced viability under host-mimicking conditions. However, phenotypic screening demonstrated that the tcb1Δ mutant does not display sensitivity to cell wall or osmotic stressors, and TCB1 deletion did not attenuate virulence in the Tenebrio larval model. These findings suggest that TCB1 functions as a specialized regulator of fungal growth at 37 °C, capsule size, and GXM shedding. This study validates our integrative approach for guiding the identification of these complex regulators. Full article

The Spt-Ada-Gcn5 acetyltransferase (SAGA) complex is a conserved transcriptional coactivator that coordinates histone modifications and transcriptional regulation in eukaryotes. In Cryptococcus neoformans, SAGA governs key virulence traits, yet the roles of several core scaffold subunits remain undefined. Here, we characterize the functional roles of Spt7, a core SAGA component, in C. neoformans. Comparative genomics revealed that C. neoformans Spt7 retains conserved histone fold and bromodomain motifs. Deletion of SPT7 produced pleiotropic phenotypes, including defective melanization and capsule formation, impaired titan cell development, and heightened sensitivity to thermal, metal, antifungal, and cell wall stresses. The spt7Δ mutant exhibited strong sensitivity to the echinocandin micafungin, implicating Spt7 in maintaining cell wall integrity. The spt7Δ mutant was avirulent in a murine inhalation model. At the chromatin level, SPT7 deletion disrupted SAGA-dependent histone post-translational modifications, increasing H2B ubiquitination while reducing H3K14ac and H3K18ac levels. Proteomic profiling revealed reduced abundance of ribosomal, mitochondrial, and translational proteins and upregulation of lipid metabolic and secretory pathway components. Collectively, our findings establish Spt7 as a central integrator of SAGA-mediated chromatin regulation, proteomic balance, and virulence in C. neoformans and highlight the SAGA core as a potential antifungal target. Full article

Central nervous system (CNS) cryptococcosis caused by Cryptococcus neoformans is a severe opportunistic infection that primarily affects individuals with impaired cellular immunity. Although the classic presentation includes headache, fever, and meningeal signs, chronically immunosuppressed patients may develop atypical neuropsychiatric manifestations, leading to diagnostic delays. We report the case of a 53-year-old man with rheumatoid arthritis (RA) receiving long-term prednisolone and etanercept therapy, who presented with a 7-day history of depressive mood, anhedonia, social withdrawal, irritability, and progressive confusion. Neurological examination revealed disorientation without focal deficits. Brain imaging showed only mild cortical atrophy, and cerebrospinal fluid (CSF) analysis revealed lymphocytic pleocytosis, low glucose, and elevated protein levels. Multiplex PCR (FilmArray^®) of CSF identified Cryptococcus neoformans, CSF positive to C. neoformans. The patient was treated with liposomal amphotericin B followed by fluconazole, resulting in gradual improvement of both neurological and psychiatric symptoms. This case highlights an unusual presentation of CNS cryptococcosis in a non-HIV immunosuppressed patient with RA, emphasizing that acute psychiatric or cognitive changes can be the predominant manifestation. Clinicians should consider fungal infections in the differential diagnosis of acute neuropsychiatric symptoms in patients receiving chronic corticosteroid and biologic therapy. Early recognition and molecular diagnosis can facilitate timely antifungal treatment, potentially improving prognosis and reducing morbidity associated with delayed therapy. This report underscores the importance of awareness of atypical presentations of opportunistic infections in immunosuppressed populations. Full article