Search Results (692)

Green synthesis of gold nanoparticles (AuNPs) provides a significantly eco-friendly and low-impact counterpart to conventional chemical methods. In the present study, we synthesized gold nanoparticles using Schinus molle (P-AuNPs) aqueous extract as a reducing and stabilizing agent. The obtained nanoparticles were then stabilized by another biocompatible agent, the chiral amino acids L-cysteine (L-Cys-AuNPs) and D-cysteine (D-Cys-AuNPs), to estimate the potential of the surface modification for enhancing AuNPs surface chemistry and antimicrobial action. The synthesized gold nanoparticles were confirmed by UV-Vis spectroscopy, FTIR, XRD, and circular dichroism to validate their formation, crystalline structure, surface properties, and chirality. Physicochemical characterization confirmed the formation of crystalline AuNPs with size and morphology modulated by chiral functionalization. TEM and DLS analyses showed that L-cysteine-functionalized AuNPs were smaller and more uniform, while FTIR and circular dichroism spectroscopy confirmed surface binding and the induction of optical activity, respectively. L-Cys-AuNPs exhibited the highest antimicrobial efficacy against a broad spectrum of microorganisms, including Escherichia coli, Salmonella enterica, Listeria monocytogenes, Staphylococcus aureus, Staphylococcus epidermidis, and, notably, Candida albicans. L-Cys-AuNPs showed the lowest MIC and MBC values, highlighting the synergistic effect of chirality on biological performance. These findings suggest that L-cysteine surface engineering significantly enhances the therapeutic potential of AuNPs, particularly in combating drug-resistant fungal pathogens such as C. albicans. This research paves the way for the development of next-generation antimicrobial agents, reinforcing the relevance of green nanotechnology in the field of materials science and nanotechnology. Full article

Bee products, in particular honey, propolis and bee venom, are of growing scientific interest due to their broad spectrum of antimicrobial activity. In the face of increasing antibiotic resistance and the limitations of conventional therapies, natural bee-derived substances offer a promising alternative or support for the treatment of infections. This paper summarizes the current state of knowledge on the chemical composition, biological properties and antimicrobial activity of key bee products. The main mechanisms of action of honey, propolis and bee venom are presented, and their potential applications in the prevention and treatment of bacterial, viral and fungal infections are discussed. Data on their synergy with conventional drugs and prospects for use in medicine and pharmacology are also included. The available findings suggest that, with appropriate standardization and further preclinical and clinical analyses, bee products could become an effective support for the treatment of infections, especially those caused by pathogens resistant to standard therapies. Full article

Cancer and infectious diseases are major causes of global morbidity and mortality stressing the need to find novel drugs with promising dual anticancer and antimicrobial efficacy. Gold complexes have been studied for the past years due to their anticancer properties, with a few of them displaying antimicrobial properties, which support their pharmacological interest. Within this scope, we investigated six gold bisdithiolate complexes [Au (bdt)₂]⁻ (1), [Au (dcbdt)₂]⁻ (2), [Au (3-cbdt)₂]⁻ (3), [Au (4-cbdt)₂]⁻ (4), [Au (pdt)₂]⁻ (5) and [Au (dcdmp)₂]⁻ (6), and) against the ovarian cancer cell lines A2780 and A2780cisR, the Gram-positive bacteria Staphylococcus aureus Newman, the Gram-negative bacteria Escherichia coli ATCC25922 and Burkholderia contaminans IST408, and the pathogenic yeasts Candida glabrata CBS138 and Candida albicans SC5134. Complexes 2 and 6, with ligands containing aromatic pyrazine or phenyl rings, substituted with two cyanonitrile groups, showed after 24 h of incubation high anticancer activities against A2780 ovarian cancer cells (IC₅₀~5 µM), being also able to overcome cisplatin resistance in A2780cisR cells. Both complexes induced the formation of ROS, activated caspase-3/7, and induced necrosis (LDH release) in a dose-dependent way, in a greater extent in the case of 6. Among the bacterial and fungal strains tested, only complex 6 presented antimicrobial activity against S. aureus Newman, indicating that this complex is a potential novel anticancer and antibacterial agent. These results delve into the structure-activity relationship of the complexes, considering molecular alterations such as replacing a phenyl group for a pyrazine group, and the inclusion of one or two cyanonitrile appendage groups, and their effects on biological activity. Overall, both complexes were found to be promising leads for the development of future anticancer drugs against low sensitive or cisplatin resistant tumors. Full article

Polymicrobial biofilms involving fungal and bacterial species are increasingly recognized as contributors to persistent infections, particularly in the oral cavity. Candida albicans and Aggregatibacter actinomycetemcomitans are two commensals that can turn into opportunistic pathogens and are able to form robust biofilms. Objectives: This study aimed to assess the interaction dynamics between these two microorganisms and to evaluate their susceptibility to fluconazole and azithromycin in single- and mixed-species forms. Methods: Biofilm biomass was quantified using crystal violet assays, while biofilm cell viability was assessed through CFU enumeration (biofilm viability assay). To assess the resistance properties of single versus mixed-species coincubations, we applied the antimicrobial susceptibility test (AST) to each drug, and analysed spatial organization with confocal laser scanning microscopy, using PNA-FISH. Results: The results indicated that both species can coexist without significant mutual inhibition. However, a non-reciprocal synergism was also observed, whereby mixed-species biofilm conditions promoted the growth of A. actinomycetemcomitans, while C. albicans growth remained stable. As expected, antimicrobial tolerance was elevated in mixed cultures, likely due to enhanced extracellular matrix production and potential quorum-sensing interactions, contributing to increased resistance against azithromycin and fluconazole. Conclusions: This study provides novel insights into previously rarely explored interactions between C. albicans and A. actinomycetemcomitans. These findings underscore the importance of investigating interspecies interactions within polymicrobial biofilms, as understanding their mechanisms, such as quorum-sensing molecules and metabolic cooperation, can contribute to improved diagnostics and more effective targeted therapeutic strategies against polymicrobial infections. Full article

Invasive fungal infections (IFIs) represent a growing global health threat, particularly for immunocompromised populations, with mortality exceeding 1.5 million deaths annually. Despite their clinical and economic burden—costing billions in healthcare expenditures—fungal infections remain underprioritized in public health agendas. This review examines the current landscape of antifungal therapy, focusing on advances, challenges, and future directions. Key drug classes (polyenes, azoles, echinocandins, and novel agents) are analyzed for their mechanisms of action, pharmacokinetics, and clinical applications, alongside emerging resistance patterns in pathogens like Candida auris and azole-resistant Aspergillus fumigatus. The rise of resistance, driven by agricultural fungicide use and nosocomial transmission, underscores the need for innovative antifungals, rapid diagnostics, and stewardship programs. Promising developments include next-generation echinocandins (e.g., rezafungin), triterpenoids (ibrexafungerp), and orotomides (olorofim), which target resistant strains and offer improved safety profiles. The review also highlights the critical role of “One Health” strategies to mitigate environmental and clinical resistance. Future success hinges on multidisciplinary collaboration, enhanced surveillance, and accelerated drug development to address unmet needs in antifungal therapy. Full article

The worldwide increase in antifungal resistance, particularly in Candida sp., requires the exploration of novel therapeutic agents. Natural compounds have been a rich source of antimicrobial molecules, where peptides constitute the class of the most bioactive components. Therefore, this study looks into the target-specific binding efficacy of insect-derived antifungal peptides (n = 37) as possible alternatives to traditional antifungal treatments. Using computational methods, namely the HPEPDOCK and HDOCK platforms, molecular docking was performed to evaluate the interactions between selected key fungal targets, lanosterol 14-demethylase, or LDM (PDB ID: 5V5Z), secreted aspartic proteinase-5, or Sap-5 (PDB ID: 2QZX), N-myristoyl transferase, or NMT (PDB ID: 1NMT), and dihydrofolate reductase, or DHFR, of C. albicans. The three-dimensional peptide structure was modelled through the PEP-FOLD 3.5 tool. Further, we predicted the physicochemical properties of these peptides through the ProtParam and PEPTIDE 2.0 tools to assess their drug-likeness and potential for therapeutic applications. In silico results show that Blap-6 from Blaps rhynchopeter and Gomesin from Acanthoscurria gomesiana have the most antifungal potential against all four targeted proteins in Candida sp. Additionally, a molecular dynamics simulation study of LDM-Blap-6 was carried out at 100 nanoseconds. The overall predictions showed that both have strong binding abilities and are good candidates for drug development. In in vitro studies, Gomesin achieved complete biofilm eradication in three out of four Candida species, while Blap-6 showed moderate but consistent reduction across all species. C. tropicalis demonstrated relative resistance to complete eradication by both peptides. The present study provides evidence to support the antifungal activity of certain insect peptides, with potential to be used as alternative drugs or as a template for a new synthetic or modified peptide in pursuit of effective therapies against Candida spp. Full article

Drug resistance in Candida may result in either a fitness cost or a fitness advantage. Candida auris, whose intrinsic drug resistance remains unclear, has emerged as a significant human pathogen. We aimed to investigate whether Candida fitness, including early interaction with the host innate immune system, depends on the antifungal susceptibility phenotype and putative-associated resistance mutations. We compared interleukin-1β, interleukin-6, interleukin-8, and tumor necrosis factor α production by human colorectal adenocarcinoma cells stimulated by fluconazole-susceptible and fluconazole-resistant strains of Candida albicans, C. parapsilosis, C. tropicalis, and C. glabrata, as well as fluconazole-resistant C. auris strains. Sensitive Candida strains induced lower cytokine levels compared with C. auris and resistant strains, except for TNF a. Resistant strains induced cytokine levels like C. auris, except for higher IL-1β and lower TNF-α. Susceptible strains exhibited cytokine profiles distinct from those of resistant strains. C. auris induced cytokine levels comparable to resistant strains but displayed profiles resembling those of susceptible strains. This study highlights the relationship among antifungal susceptibility, fungal fitness and host early immunity. C. auris behavior appears to be between fluconazole-sensitive and fluconazole-resistant strains. Understanding these dynamics may enhance the knowledge of the survival and reproduction of resistant Candida and the epidemiology of fungal infections. Full article

Background: Fungal infections, particularly those caused by Candida species, pose a serious threat to immunocompromised individuals, and therapeutic options are limited due to toxicity and resistance concerns. This in vitro study aimed to explore the feasibility of using liquid fractions of autologous platelet concentrates (APCs), namely concentrated platelet-rich fibrin (c-PRF) and liquid-phase concentrated growth factor (LPCGF), as carriers for antifungal drugs. Methods: The research was conducted in two phases: first, to evaluate the inherent antifungal properties of different APCs; and second, to assess their effectiveness as drug carriers for fluconazole and voriconazole against Candida albicans, Candida glabrata, and Candida krusei. Results: Results showed that APCs alone exhibited no direct antifungal effects. However, when combined with antifungal agents, notable inhibition zones were observed—especially with voriconazole against C. krusei and fluconazole against C. glabrata using c-PRF. Both c-PRF and LPCGF were compatible with the drugs and did not hinder clot formation. Conclusions: These findings suggest that APCs can act as effective vehicles for localized antifungal drug delivery and warrant further investigation for clinical application in treating fungal-related oral diseases. Full article

Background/Objectives: There is an increasing incidence of fungal infections in conjunction with the rise in resistance to medical treatment. Antimicrobial resistance is frequently associated with virulence factors such as adherence and the capacity of biofilm formation, which facilitates the evasion of the host immune response and resistance to drug action. Novel therapeutic strategies have been developed to overcome antimicrobial resistance, including the use of different type of nanomaterials: metallic (Au, Ag, Fe₃O₄ and ZnO), organic (e.g., chitosan, liposomes and lactic acid) or carbon-based (e.g., quantum dots, nanotubes and graphene) materials. The objective of this study was to evaluate the action of nanoparticles of different synthesis and with different coatings on fungi of medical interest. Methods: Literature research was conducted using PubMed and Google Scholar databases, and the following terms were employed in articles published up to June 2025: ‘nanoparticles’ in combination with ‘fungal biofilm’, ‘Candida biofilm’, ‘Aspergillus biofilm’, ‘Cryptococcus biofilm’, ‘Fusarium biofilm’ and ‘dermatophytes biofilm’. Results: The utilization of nanoparticles was found to exert a substantial impact on the reduction in fungal biofilm, despite the presence of substantial variability in minimum inhibitory concentration (MIC) values attributable to variations in nanoparticle type and the presence of capping agents. It was observed that the MIC values were lower for metallic nanoparticles, particularly silver, and for those synthesized with polylactic acid compared to the others. Conclusions: Despite the limited availability of data concerning the stability and biocompatibility of nanoparticles employed in the treatment of fungal biofilms, it can be posited that these results constitute a significant initial step. Full article

Fungal infections are recognized as a global health issue, in particular considering the spread of different forms of resistance to the commonly used antifungal drugs and their involvement in the occurrence of co-infections in hospitalized and immunocompromised patients. In this paper, a small series of hybrid compounds were designed and synthesized by linking the privileged chromone and xanthone scaffolds, endowed with recognized antimicrobial potential, to the tert-butylbenzylamino portion of the antifungal drug butenafine, through selected linkers. The results showed for the xanthone-based compound 3 a promising activity towards C. auris, C. tropicalis, and C. neoformans, for which a high degree of resistance is commonly observed, together with a significant antibacterial potency towards Gram-positive bacteria, such as S. aureus. Considering that compound 3 displayed favorable selectivity and therapeutic indexes (9.1 and >16, respectively), it appeared as a valuable prototype, deserving further hit-to-lead optimization. Full article

Tuberculosis (TB) poses a persistent global health threat exacerbated by the emergence of drug-resistant strains; hence, there is a continuous quest for novel antimicrobial agents. Despite efforts to develop effective therapies, existing treatments require a relatively long duration of therapy to eradicate the pathogen due to its virulence factors, pathogenesis patterns, and ability to enter dormant states. This can lead to a higher risk of treatment failure due to poor patient adherence to the complex regimen. As a result, considerable research is necessary to identify alternative antituberculosis agents. The marine environment, particularly marine-derived fungi, has recently gained interest due to its potential as an abundant source of bioactive natural products. This review covers 19 genera of marine-derived fungi and 139 metabolites, 131 of which exhibit antimycobacterial activity. The integrated dataset pinpoints the fungal genera and chemical classes that most frequently yield potent antimycobacterial hits while simultaneously exposing critical gaps, such as the minimal evaluation of compounds against dormant bacilli and the presence of underexplored ecological niches and fungal genera. Several compounds exhibit potent activity through uncommon mechanisms, including the inhibition of mycobacterial protein tyrosine phosphatases (MptpB/MptpA), protein kinase PknG, ATP synthase and the disruption of mycobacterial DNA via G-quadruplex stabilization. Structure–activity relationship (SAR) trends are highlighted for the most potent agents, illuminating how specific functional groups underpin target engagement and potency. This review also briefly proposes a dereplication strategy and approaches for toxicity mitigation in the exploration of marine-derived fungi’s natural products. Through this analysis, we offer insights into the potency and challenges of marine-derived fungi’s natural products as hit compounds or scaffolds for further antimycobacterial research. Full article

Antimicrobial resistance represents one of the most critical public health challenges of the 21st century. The emergence of multidrug resistance (MDR) in bacterial and fungal pathogens to diverse chemical agents severely impedes the effective treatment of diseases such as cancer and systemic infections. The rapid escalation of microbial resistance underscores the urgent need for the discovery of novel antimicrobial agents and innovative approaches to drug development. In both clinical and industrial contexts, the identification of new antibiotics and antifungals remains pivotal for pathogen control. Current research efforts focus on the development of alternative formulations that offer high efficacy, reduced resistance potential, minimal side effects, and synergistic interactions, particularly those derived from natural sources. Filamentous fungi originating from extreme environments have evolved to thrive under harsh conditions, making them promising reservoirs of bioactive metabolites with unique structural and functional properties. These fungi exhibit potent antimicrobial activity through diverse mechanisms that disrupt essential cellular processes in pathogens. Despite their remarkable potential, the bioprospecting of extremophilic filamentous fungi for drug development remains underexplored. This highlights the necessity for expanded research into the efficacy and safety of their derived compounds. This review aims to emphasize the capacity of extremophilic fungi to produce antimicrobial agents, elucidate resistance mechanisms, characterize fungal bioactive extracts, and analyze their molecular actions in the context of their extreme ecological niches. Full article

Candida auris is an emerging fungal pathogen characterized by high levels of antifungal drug resistance and hospital outbreaks in a global distribution. Since introduction to the United States, it has been identified most frequently in New York, Illinois, California, Florida, and Nevada. Its surge poses significant risk as a nosocomial infection with multi-drug resistance, with clades bearing resistance to fluconazole, micafungin, and amphotericin B. Within the state of Nevada, and specifically the greater Las Vegas area in the southern part of the state, there are ongoing outbreaks from clade I and clade III, with 1728 confirmed clinical cases identified as of January 2025. In northern Nevada, three clinical cases have been identified to date, with two occurring at our facility. Both patients had been hospitalized at facilities in Las Vegas, Nevada. The C. auris strains isolated from these two cases have been identified as belonging to clade III and demonstrate resistance to fluconazole. Genome sequencing of the C. auris isolates indicates close genetic identity to strains from the Las Vegas outbreak. These data indicate that the spread of these clonal isolates is due to hospitalization and subsequent patient relocation to northern Nevada, revealing the ongoing importance of screening for geographic spread. Full article

Background/objectives: Candida albicans is a major fungal pathogen that poses a serious threat to immunocompromised individuals. The increasing prevalence of fluconazole-resistant strains presents a critical clinical challenge, emphasizing the urgent need for novel therapeutic strategies. This study aimed to evaluate the prophylactic potential of a new liposomal vaccine formulation, Tuft-lip-WCAgs, comprising Tuftsin and C. albicans whole cell antigens, in providing immune protection against systemic candidiasis. Methods: The vaccine formulation was tested in a murine model of systemic C. albicans infection. The efficacy of the Tuft-lip-WCAg vaccine was evaluated through a survival analysis, fungal burden assessments, and immunological profiling. Immune responses were assessed by measuring serum antibody titers and isotypes, T cell proliferation, and cytokine secretion (IFN-γ and IL-4) from splenocytes. Results: FLZ treatment showed weak antifungal activity, high MIC values, and limited biofilm disruption and failed to ensure long-term survival, resulting in 100% mortality by day 40. In contrast, Tuft-lip-WCAg vaccination was well tolerated and conferred complete protection, with no detectable fungal burden by day 40. Vaccinated mice exhibited significantly elevated total antibody titers (166,667 ± 14,434), increased IgG2a levels, and enhanced T cell proliferation (stimulation index: 3.9 ± 0.84). Splenocytes from immunized mice secreted markedly higher levels of IFN-γ (634 ± 128 pg/mL) and IL-4 (582 ± 82 pg/mL), indicating a balanced Th1/Th2 immune response. Tuft-lip-WCAg vaccination also achieved 100% survival and the lowest kidney fungal burden (556 ± 197 CFUs/g). Conclusions: Tuft-lip-WCAg formulation is a safe, immunogenic, and highly effective vaccine candidate that offers complete protection against drug-resistant C. albicans in a murine model. These findings support its promise as a novel immunoprophylactic strategy, particularly for immunocompromised populations at high risk of invasive candidiasis. Full article

The World Health Organization included Cryptococcus neoformans and Cryptococcus gattii in its priority fungal pathogen list due to their high mortality rates and frequent treatment failures. These facts have driven research toward the discovery of new compounds for the treatment of cryptococcosis. In this study, we investigated the therapeutic potential of two complexes, [Cu(phendione)₃](ClO₄)₂·4H₂O (Cu-phendione) and [Ag(phendione)₂]ClO₄ (Ag-phendione), against drug-resistant clinical isolates of C. gattii and C. neoformans. Both complexes demonstrated anti-Cryptococcus activity, with Cu-phendione exhibiting minimum inhibitory concentration (MIC) values of 6.25 μM for C. gattii and 3.125 μM for C. neoformans, while Ag-phendione showed an MIC of 1.56 μM for both Cryptococcus species. Notably, both Cu-phendione and Ag-phendione complexes exhibited enhanced antifungal activity against reference strains of C. neoformans and C. gattii. In silico analysis identified both complexes as highly promising, exhibiting good oral bioavailability, high gastrointestinal absorption, and moderate skin permeability. Moreover, neither complex demonstrated toxicity toward sheep erythrocytes at concentrations up to 62.5 μM, with a selectivity index (SI) exceeding 10 for Cu-phendione and 40 for Ag-phendione. In vivo testing using the Galleria mellonella model demonstrated that both complexes were non-toxic, with 100% larval survival at concentrations up to 1000 μM and SI exceeding 160 following a single administration. Interestingly, larvae exposed to Cu-phendione at concentrations of 15.6–31.25 μM exhibited a significant increase in the density of hemocytes, the immune cells responsible for defense in invertebrates. Furthermore, multiple treatments with 62.5 μM of complexes caused either no larval mortality, hemocyte alterations, or changes in silk production or coloration, indicating a lack of toxicity. These findings suggest that Cu-phendione and Ag-phendione may serve as promising antifungal alternatives against Cryptococcus, with minimal host toxicity. Full article