Search Results (978)

Background/Objectives: Cutaneous leishmaniasis (CL) remains a major neglected tropical disease, and current chemotherapeutic options are limited by toxicity and emerging resistance. Repurposing azole antifungals is a promising approach, as they target ergosterol biosynthesis, a pathway also essential in Leishmania spp. This study investigated the antileishmanial potential of econazole through in vitro and in vivo assays. Methods: Econazole activity was evaluated against Leishmania amazonensis promastigotes and intracellular amastigotes using MTT and luminescence-based methods. Cytotoxicity in NCTC cells was determined to calculate the selectivity index (SI). Drug interactions with miltefosine were assessed by fixed-ratio isobologram analysis. In vivo efficacy was examined in BALB/c mice infected with L. amazonensis and orally treated with econazole (2.5, 5, or 10 mg/kg/day) for 28 days. Lesion development and parasite burden were monitored. Molecular docking simulations were performed using SwissDock. Results: Econazole showed potent in vitro activity, with EC₅₀ values of 8.9 µM for promastigotes and 11 µM for intracellular amastigotes, and a CC₅₀ of 31 µM. Isobologram analysis revealed additive interactions with miltefosine (ΣFIC 0.5–1.2; mean 0.95). In vivo, econazole reduced lesion size and parasite load, achieving up to 75% reduction at 10 mg/kg/day. Docking results suggested that econazole may inhibit sterol biosynthesis, potentially through interaction with 14α-demethylase. Conclusions: These findings provide the first evidence of econazole activity against L. amazonensis in vitro and in vivo. Its exploratory efficacy and compatibility with miltefosine support further investigation of econazole as a repurposed candidate for CL, including optimization of dosing strategies and combination regimens. Full article

Background: Antifungal resistance among Candida species and related genera, coupled with the lack of new drugs, poses a significant threat to public health. Several studies have demonstrated a relationship between virulence factors and resistance. Current objectives include identifying new targets and searching for new natural molecules. Carvacrol, a natural phenolic compound, has been shown to have antimicrobial properties; however, its impact on the virulence of species other than Candida albicans and related yeast genera remains underexplored. Methods: The antifungal activity of carvacrol was evaluated against clinical isolates of Candidozyma auris, Meyerozyma guilliermondii, and Candida dubliniensis, as well as its effect on adhesion, hydrophobicity, biofilm formation and osmotic stress tolerance. In vivo activity was assessed using the Galleria mellonella infection model at MIC concentrations. Results: Carvacrol inhibited adherence and significantly reduced both early and preformed biofilms in M. guilliermondii and C. dubliniensis. In C. auris, the compound produced a modest reduction in biofilm activity but significantly enhanced larval survival in the in vivo model (~20%, p < 0.01). Carvacrol also induced increased tolerance of C. auris to osmotic stress, suggesting activation of adaptive pathways. Conclusions: Carvacrol exhibits species-specific effects, acting as an antivirulence modulator in M. guilliermondii and C. dubliniensis and attenuating virulence in vivo in C. auris. These findings support the potential of carvacrol as an adjuvant antifungal strategy, particularly against C. auris, and highlight the relevance of targeting virulence traits to reduce selective pressure and limit antifungal resistance. Full article

Currently, the increased incidence of invasive fungal infections globally is posing a significant challenge to public health. Due to drug resistance issues, the clinical efficacy of existing antifungal drugs is seriously insufficient, while new drug development progresses slowly. Consequently, there is an urgent need to discover and develop novel antifungal therapeutics. Natural products have the characteristics of wide sources and few adverse reactions and are one of the sources for developing antifungal drugs. Numerous studies have shown that many compounds isolated from plants and traditional Chinese medicine have antifungal activity and diverse antifungal mechanisms. Thymol, a monoterpene phenol compound from thyme (Lamiaceae), has multiple biological functions such as antibacterial, antioxidant, and anti-inflammatory. Recent research has found that thymol has strong antifungal activity, and its molecular mechanisms involve cell membrane rupture, interference with cell wall synthesis, disruption of mitochondrial function and energy metabolism, inhibition of biofilm, inhibition of virulence factor expression, inhibition of key enzymes, and induction of cell apoptosis. This review aimed to summarize the antifungal activity of thymol and the underlying molecular mechanisms, safety, and potential clinical applications. Emerging technologies in thymol delivery systems and future research directions are also discussed. The comprehensive analysis aims to provide a detailed understanding of fungal infections and the role of thymol in antifungal treatment, offering insights for further research and clinical practice. 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

Invasive Candida infections in the neonatal intensive care unit (NICU) are associated with significant morbidity and mortality, particularly among extremely preterm neonates. Early treatment with antifungals is critical to improve survival rates and avoid long-term adverse outcomes. Prevention with antifungal prophylaxis in high-risk neonates has been shown to reduce the prevalence of invasive Candida infections effectively. However, the irrational and/or inappropriate use of antifungals has been documented. This narrative review aims to provide an overview of the rationales for the inappropriate use of antifungals in the NICU, the consequences that ensue, and the promising strategy of antifungal stewardship programs to optimize antifungal use. The nonspecific clinical presentation of systemic Candida infections and the lack of rapid, accurate diagnostic techniques for Candida identification and specification in most settings lead to a high rate of empirical treatment in neonates without a proven infection. Moreover, evidence on the optimal dosing of antifungal agents and the treatment duration in the neonatal population is lacking, which may result in excessive or subtherapeutic drug exposure. Antifungal misuse is associated with microbiological consequences, including the emergence of antifungal-resistant Candida strains, and clinical consequences, such as drug toxicities and alterations in the intestinal mycobiome. It is therefore imperative to optimize antifungal use in the NICU. The implementation of antifungal stewardship programs, which, through a multidisciplinary approach, aim to improve diagnosis and guide clinicians on antifungal selection, dosing, and duration for both prevention and treatment according to the local epidemiology, represents a promising strategy for antifungal optimization in the NICU. Full article

Diseases associated with yeast pathogens have become an increasingly serious global health issue. The range of virulence factors and the development of mechanisms of resistance have posed a significant challenge in the fight against these types of infections. Lectins, proteins capable of reversibly binding to carbohydrates and glycoconjugates, have been assessed as antifungal agents. This review shows that lectins have demonstrated versatility and significant potential as therapeutic agents against Candida, Nakaseomyces and Cryptococcus. These molecules act through diverse mechanisms, including disruption of fungal cell membranes, induction of oxidative stress, inhibition of ergosterol biosynthesis, and interference with mitochondrial and lysosomal functions. Some lectins have been shown to inhibit yeast-to-hyphae morphological transitions and biofilm formation, which are critical virulence factors for pathogenic yeasts. Moreover, some lectins have shown potential to enhance the efficacy of conventional antifungal drugs through synergistic interactions, though these effects can depend on the fungal isolate. Beyond in vitro activity, translational considerations remain underdeveloped in the context of antifungal applications of lectins. Some lectins exhibit minimal toxicity, while others require careful dosing due to potential toxicity or undesired immunogenicity. Delivery and stability also present challenges, though strategies such as chemical modifications and topical, mucosal, or nanoparticle-based formulations show promise. Overall, the multifaceted antifungal activities of lectins highlight their promising role as innovative candidates in the development of novel therapies to address the growing challenge of yeast pathogen resistance. However, significant knowledge gaps persist, highlighting the urgent need for coordinated research that bridges in vitro findings with practical pharmacological applications. Full article

Candida albicans, a commensal and opportunistic fungal pathogen, is a major clinical concern due to its ability to cause infections ranging from mild mucosal conditions to life-threatening systemic diseases, particularly in immunocompromised patients. Its capacity to form biofilms on medical devices further complicates treatment by enhancing antifungal resistance and immune evasion. In the search for novel therapeutic strategies, the lysine-enriched amphibian-derived temporin B analog, TB_KKG6K, has emerged as a promising antifungal agent. This study demonstrates that TB_KKG6K exhibits potent fungicidal activity against planktonic C. albicans cells, with a low potential to induce adaptation or resistance. TB_KKG6K has no adverse impact on the anti-Candida efficacy of standard antifungal drugs when applied in combination, interacting additively with amphotericin B and caspofungin in a fungicidal mode of action. Additionally, TB_KKG6K effectively reduces biofilm maturation on silicone elastomers, a material commonly used in medical devices, further highlighting its therapeutic potential. These data together with our previous documentation of minimal cytotoxicity and irritation potential in human cells makes TB_KKG6K a strong candidate for combating both planktonic and biofilm-associated C. albicans infections. These findings underscore the dual efficacy of TB_KKG6K and its potential to address the challenges posed by C. albicans in clinical settings. Full article

This study evaluated the in vitro interaction of 5-fluorouridine (5-FUrd) with antifungal drugs and examined the role of efflux pumps in 5-FUrd resistance. Eleven reference Candida strains and twenty-three clinical C. albicans isolates from gynecological patients were tested. The antifungal activity of 5-FUrd alone and in combination with amphotericin B, fluconazole, voriconazole, caspofungin, and flucytosine was assessed using the checkerboard microdilution method. Efflux pump activity was evaluated using two inhibitors: carbonyl cyanide 3-chlorophenylhydrazone (CCCP) and verapamil. 5-FUrd exhibited antifungal activity against both the reference and clinical Candida strains, with MIC values ranging from 0.1 µg/mL to 409.6 µg/mL. The checkerboard assays revealed primarily no interactions in the reference Candida strains, whereas the reference C. albicans and clinical C. albicans isolates showed notable synergy between 5-FUrd and fluconazole, voriconazole, or caspofungin. The efflux pump inhibitors reduced the MICs of 5-FUrd in the resistant strains of C. lusitaniae, C. kefyr, and particularly C. krusei, suggesting efflux-mediated resistance mechanisms. This study highlights the potential of 5-FUrd, alone or combined with azoles or caspofungin, as an adjunct therapy against Candida infections. It also suggests that reduced susceptibility may be linked to efflux pump activity in certain strains. Full article

Fungi constitute a diverse kingdom of eukaryotic organisms with remarkable adaptability, ranging from saprophytic decomposers to lethal human pathogens. This review synthesizes current insights into fungal adaptations that underline pathogenesis, focusing on enzymatic strategies including hydrolytic enzymes, metabolic and physiological plasticity such as thermotolerance and nutrient flexibility, and evasion of host immunity via mechanisms like melanin production and biofilm formation. We detail fungal survival tactics including spore formation and genomic and epigenetic plasticity, which contribute to resilience and evolution under environmental and host-imposed stresses. The escalating emergence of antifungal resistance and the global impact of environmental changes underscore urgent clinical challenges. Advances in diagnostics, novel therapeutics incorporating AI-assisted drug discovery, and integrated One Health approaches are poised to combat this growing threat. This comprehensive overview aims to guide future research and inform clinical management of fungal infections in an era of dynamic microbial evolution and environmental upheaval. Full article

Invasive pulmonary aspergillosis (IPA), traditionally associated with severe immunosuppression and neutropenia, is increasingly reported among non-neutropenic patients. This epidemiological shift highlights the need for a revised understanding of IPA’s pathogenesis, clinical presentation, and management strategies. The rising incidence in these populations likely reflects improved diagnostic capabilities and recognition of additional predisposing factors. Although profound immunosuppression remains a key risk, even moderate alterations in innate or adaptive immunity can promote Aspergillus spp. invasion. This review summarizes current knowledge and recent advances in the diagnosis and treatment of IPA. Specifically, treatment strategies must be tailored to comorbidities, infection severity, and drug tolerance. Early diagnosis and prompt antifungal therapy are crucial for improving outcomes. Voriconazole remains the first-line treatment, though therapeutic drug monitoring is essential to ensure efficacy and minimize toxicity. Isavuconazole represents an effective alternative, offering comparable efficacy, improved safety, predictable pharmacokinetics, and convenient once-daily dosing. Liposomal amphotericin B serves as a valuable option in severe or refractory cases due to its broad-spectrum activity and reduced nephrotoxicity. Supportive measures—such as respiratory optimization, comorbidity management, and immunomodulatory therapies—are integral to care. Prognosis depends on infection extent, immune status, and timeliness of therapy. Emerging antifungal agents, including olorofim, ibrexafungerp, and fosmanogepix, show promise against resistant Aspergillus species, expanding treatment options. Overall, IPA management in non-neutropenic patients requires a multidisciplinary, patient-centered approach integrating established antifungals, supportive care, and novel therapeutic advances. Full article

Candida biofilms play a critical role in clinical settings, contributing to persistent and device-associated infections and conferring resistance to antifungal agents, particularly in immunocompromised or hospitalized patients. Biofilm formation varies among Candida species, including C. albicans and non-albicans species, such as C. glabrata, C. tropicalis, C. parapsilosis, and C. auris, due to species-specific transcriptional networks that regulate modes of biofilm development, extracellular matrix composition, and metabolic reprogramming. These differences influence biofilm responses to treatment and the severity of infections, which can be further complicated in polymicrobial biofilms that modulate colonization and virulence. Understanding the mechanisms driving biofilm formation and interspecies interactions is essential for developing effective therapies and requires appropriate experimental models. Available models range from simplified in vitro systems to more complex ex vivo and in vivo approaches. Static in vitro models remain widely used due to their simplicity and reproducibility, but they poorly mimic physiological conditions and require careful standardization. Ex vivo tissue models offer a balance between practicality and biological relevance, enabling the study of biofilm physiology, host–microbe interactions and immune responses. In vivo models, primarily in mice, remain the gold standard for testing antifungal therapies, while alternative systems such as Galleria mellonella larvae provide simpler, cost-effective approaches. Advanced in vitro platforms, including organ-on-chip systems, bridge the gap between simplified tests and physiological relevance by simulating fluid dynamics, tissue architecture, and immune complexity. This review aims to examine Candida biofilms across species, highlighting differences in structural diversity and clinical implications, and to provide a guide to the most widely used experimental models supporting studies on Candida biofilm biology for the development of new therapeutic targets or drug testing. Full article

Background: Nosocomial infections represent a significant clinical burden due to high morbidity, mortality and healthcare costs. Invasive fungal infections, particularly those caused by Candida species, are of growing concern due to increasing antifungal resistance, which limits therapeutic options and worsens patient outcomes. This study aimed to characterize the prevalence, species distribution, antifungal susceptibility profiles, and molecular mechanisms of resistance in clinical Candida isolates from hospitalized patients. Methods: A cross-sectional study was conducted involving 55 hospitalized patients, yielding 60 isolates from blood, secretions, fluids, and catheter tips. Species identification was performed using chromogenic media and confirmed by MALDI-TOF MS. Antifungal susceptibility testing followed CLSI M27-A4 broth microdilution guidelines for amphotericin B, fluconazole and 5-flucytosine. Gene expression of ERG2, ERG11 and MDR1 was evaluated by RT-qPCR after exposure to subinhibitory antifungal concentrations using the 2^−∆∆Ct method. Results:Candida albicans was the most frequent species, followed by Nakaseomyces glabratus, C. tropicalis and C. parapsilosis. Resistance varied among species, with elevated rates for fluconazole. ERG2 was notably overexpressed in amphotericin B-resistant isolates, while ERG11 and MDR1 showed species-dependent variation. Conclusions: Resistance mechanisms in Candida are species-specific and drug-dependent. Accurate species identification and understanding their molecular profiles are essential to guide targeted antifungal therapy and improve clinical outcomes. Full article

Microalgae are extremely diverse photosynthetic organisms, adapted to live in different habitat conditions, from freshwater to marine environments. This adaptability is also associated with the ability to produce several metabolites. Polyunsaturated aldehydes (PUAs), first identified in 1999 in Thalassiosira gravida and Skeletonema costatum, are known to influence the development of their predators, having teratogenic effects and blocking their development. PUAs have shown several activities, such as antitumor, antimicrobial and antiparasite. Another relevant compound is pheophorbide a (PPBa), a chlorophyll degradation product, which has previously shown properties useful to be considered as a photosensitizer in photodynamic therapy, demonstrating cytotoxic effects on various tumor cell lines. It has also been shown to have activity against some bacteria and fungi. Considering the growing problem of multi-antibiotic resistance of human pathogenic bacteria and the increasing market demand for new drugs, the aim of our work was to screen two PUAs, i. e., 2,4-octadienal and trans,trans-2,4-decadienal, and PPBa against a panel of human pathogenic bacteria and fungi: Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, Candida albicans and Aspergillus fumigatus. The antimicrobial activity was evaluated through MIC (Minimum Inhibitory Concentration) and MFC/MBC (Minimum Fungicidal/Bactericidal Concentration), demonstrating that the two PUAs had a greater antimicrobial activity than PPBa on both bacteria and fungi, except for P. aeruginosa, where the antimicrobial activity was low. The compound 2,4-Octadienal showed extremely high antifungal activity, especially against the fungus A. fumigatus, where the MIC and MFC were 0.001 µL/mL and 0.004 µL/mL, respectively. These results are shedding light on the antimicrobial activity of microalgal compounds and their possible applications for different human infection diseases. Full article

A novel series of Schiff bases (3a–3k), incorporating tranexamic acid (TXA) and phenol-derived aldehydes via imine linkers, was synthesized and structurally characterized. The antimicrobial activity of the compounds was evaluated against a range of clinically and environmentally relevant bacterial and fungal strains. Among them, derivatives 3i and 3k, bearing bromine and chlorine substituents on the phenol ring, exhibited the most potent antimicrobial effects, particularly against Penicillium italicum and Proteus mirabilis (MIC as low as 0.014 mg/mL). To elucidate the underlying mechanism of action, in silico molecular docking studies were conducted, revealing strong binding affinities of 3i and 3k toward fungal sterol 14α-demethylase (CYP51B), with predicted binding energies surpassing those of the reference antifungal ketoconazole. Additionally, UV-Vis and fluorescence spectroscopy assays demonstrated good stability of compound 3k in PBS and its effective binding to human serum albumin (HSA), respectively. ADMET and ProTox-II predictions further supported the drug-likeness, low toxicity (Class 4), and favorable pharmacokinetic profile of compound 3k. Collectively, these findings highlight TXA–phenol imine derivatives as promising scaffolds for the development of next-generation antimicrobial agents, particularly targeting resistant fungal pathogens. Full article

Coccidioides immitis and C. posadasii are the causative agents of coccidioidomycosis (CM) or Valley Fever, endemic to the alkaline deserts of North and South America. Clinical treatment of CM is predominantly limited to the triazole and polyene drug classes. There are limited therapeutic options for the treatment of CM, most commonly requiring prolonged courses of therapy with established antifungal agents such as azoles and Amphotericin B, which often lead to toxicity and drug resistance. Clearly, there is a need to develop novel and better antifungal drugs against CM. This review examines both repurposed and recently discovered compounds in various stages of development for the treatment of CM. Full article