Search Results (400)

In this study, a series of novel β-phenylalanine derivatives were synthesised and evaluated for their anticancer activity. The 3-(4-methylbenzene-1-sulfonamido)-3-phenylpropanoic acid (2) was prepared using β-phenylalanine as a core scaffold. The β-amino acid derivative 2 was converted to the corresponding hydrazide 4, which enabled the development of structurally diverse heterocyclic derivatives including pyrrole 5, pyrazole 6, thiadiazole 8, oxadiazole 11, triazoles 9 and 12 with Schiff base analogues 13 and series1,2,4-triazolo [3,4-b][1,3,4]thiadiazines 14. These modifications were designed to enhance chemical stability, solubility, and biological activity. All compounds were initially screened for cytotoxicity against the A549 human lung adenocarcinoma cell line, identifying N-[3-(3,5-dimethyl-1H-pyrazol-1-yl)-3-oxo-1-phenylpropyl]-4-methylbenzenesulfonamide (5) and (E)-N-{2-[4-[(4-chlorobenzylidene)amino]-5-thioxo-4,5-dihydro-1H-1,2,4-triazol-3-yl]-1-phenylethyl}-4-methylbenzenesulfonamide (13b) as the most active. The two lead candidates were further evaluated in H69 and H69AR small cell lung cancer lines to assess activity in drug-sensitive and multidrug-resistant models. Schiff base 13b containing a 4-chlorophenyl moiety, retained potent antiproliferative activity in both H69 and H69AR cells, comparable to cisplatin, while compound 5 lost efficacy in the resistant phenotype. These findings suggest Schiff base derivative 13b may overcome drug resistance mechanisms, a limitation commonly encountered with standard chemotherapeutics such as doxorubicin. These results demonstrate the potential role of β-phenylalanine derivatives, azole-containing sulphonamides, as promising scaffolds for the development of novel anticancer agents, particularly in the context of lung cancer and drug-resistant tumours. Full article

Background/Objectives: The diminished efficacy of azoles in treating fungal infections is attributed to the emergence of resistance among pathogenic fungi. Employing a synergistic approach with other compounds to enhance the antifungal activity of azoles has shown promise, yet the availability of clinically valuable adjuvants for azoles and allylamines remains limited. Studies have demonstrated that the human host environment provides multiple carbon sources, which can influence the susceptibility of C. albicans to antifungal agents. Therefore, a comprehensive investigation into the mechanisms by which carbon sources modulate the susceptibility of C. albicans to azoles may uncover a novel pathway for enhancing the antifungal efficacy of azoles. Methods: This study explored the impact of various carbon sources on the antifungal efficacy of azoles through methodologies including minimum inhibitory concentration (MIC) assessments, super-MIC growth (SMG) assays, disk diffusion tests, and spot assays. Additionally, the mechanism by which galactose augments the antifungal activity of azoles was investigated using a range of experimental approaches, such as gene knockout and overexpression techniques, quantitative real-time PCR (qRT-PCR), Western blot analysis, and cycloheximide (CHX) chase experiments. Results: This study observed that galactose enhances the efficacy of azoles against C. albicans by inhibiting the translation of Erg1. This results in the suppression of Erg1 protein levels and subsequent inhibition of ergosterol biosynthesis in C. albicans. Conclusions: In C. albicans, the translation of Erg1 is inhibited when galactose is utilized as a carbon source instead of glucose. This novel discovery of galactose’s inhibitory effect on Erg1 translation is expected to enhance the antifungal efficacy of azoles. 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

Azole resistance in dermatophytes, particularly Trichophyton indotineae, has become a growing global concern. Current antifungal susceptibility testing protocols (EUCAST, CLSI) have limitations in reproducibility and sensitivity. This study aimed to evaluate how medium composition, incubation temperature, and spore concentration influence itraconazole susceptibility testing across various dermatophyte species. Thirty-eight clinical isolates representing Trichophyton, Microsporum, and Epidermophyton species were tested using a microplate laser nephelometry system (MLN). IC₅₀ values for itraconazole were determined in three different media (Sabouraud glucose (SG), RPMI-based (RG), and RG supplemented with casein (RGC)) at 28 °C and 34 °C. Effects of spore concentration on growth dynamics and lag phase were also analyzed. SG medium provided clear phenotypic separation between resistant and sensitive isolates. In contrast, RG and RGC showed overlapping IC₅₀ values. Lower spore concentrations revealed underlying growth differences, which were masked at higher inoculum levels. Temperature and media composition significantly affected IC₅₀ outcomes. Genotypic analysis confirmed resistance-associated Erg11B point mutations and genomic amplifications in T. indotineae, particularly in combination with Erg1 mutations, forming distinct subpopulations. SG medium combined with reduced spore concentrations offered improved differentiation of resistant versus sensitive strains. These findings support the development of more accurate susceptibility testing protocols and highlight the need to establish species-specific ECOFF values for dermatophytes. Full article

Background: Oral candidiasis (OC) and vulvovaginal candidiasis (VVC) are infections caused by species belonging to the genus Candida. In Chile, epidemiological studies on OC/VVC are scarce, leading to an overestimation of the prevalence of C. albicans. Additionally, awareness of the prevalence of species phenotypically and genotypically similar to C. albicans is lacking. The clinical impact of non-albicans species in cases of OC/VVC is also often underestimated. This study aims to determine the distribution of Candida species, their phenotypic and molecular characteristics, and their antifungal susceptibility patterns in incidents of oral and vulvovaginal candidiasis in Chile. Methods: A descriptive analysis was conducted on 101 isolates of Candida spp. obtained from OC/VVC cases. The identification of Candida species was performed using both phenotypic and molecular techniques. Antifungal susceptibility testing was carried out using the Sensititre YeastOne system. Results: Among the analyzed isolates, 89.1% were identified as C. albicans, while 10.9% were categorized as non-albicans species, including C. dubliniensis, C. glabrata sensu stricto, C. bracarensis, C. tropicalis, C. lusitaniae, and C. parapsilosis sensu stricto. The susceptibility pattern was predominantly susceptible, with only 10.9% of the total strains demonstrating resistance, and low antifungal activity in vitro was observed for Fluconazole, Voriconazole, and Posaconazole. Conclusions: The most prevalent species causing OC/VVC in Chile is C. albicans. This study also presents the first report of C. lusitaniae as a causal agent of VVC in the country. The identification of azole-resistant strains emphasizes the critical role of laboratory diagnosis in VVC cases, thereby preventing potential treatment failures. No resistance was observed in the strains associated with OC. Full article

The increasing emergence of antifungal resistance poses potential clinical challenges, particularly among immunocompromised patients with cancer at risk of invasive mold infections, but data on antifungal susceptibility trends specific to this population are few. We evaluated distributions of minimal inhibitory concentrations (MIC), including minimal effective concentrations (MEC) for echinocandins, of 11 antifungal agents for 523 mold isolates (395 Aspergillus spp.) from cancer patients. Based on published Clinical and Laboratory Standards Institute guidelines, isavuconazole had notably high rates of non-wild-type MICs for A. fumigatus (19.6%), A. flavus/oryzae (34.8%), A. niger complex (26.1%), and A. terreus complex (8.33%). Persistent low baseline resistance of A. fumigatus to voriconazole was observed across multiple years (2.4–11.5% per year, average 8.41%) without significant trends in MIC change over time. Itraconazole and posaconazole demonstrated the lowest MIC distributions (MIC₅₀ ≤ 0.06–0.5 µg/mL) of the azoles against Aspergillus spp. Amongst the A. niger complex, 29.4% (27/92) demonstrated non-wild-type MICs to itraconazole. While the A. nidulans group was less frequent (n = 24), bimodal peaks in MIC/MEC were noted for caspofungin (≤0.06 and 1 µg/mL). Non-Aspergillus molds of significance (Zygomycetes, Fusarium spp., Scedosporium spp., and Lomentospora prolificans) demonstrated variable but increased MICs to antifungal agents as previously described. Our results highlight increased rates of non-wild type MICs for Aspergillus spp. to isavuconazole and voriconazole, which are commonly used antifungal agents in cancer patients. Such AST trends should be closely monitored in populations with frequent antifungal use and encourage increased antifungal stewardship efforts. Full article

The emergence of antifungal-resistant Aspergillus fumigatus (A. fumigatus) became a serious public health concern, underscoring the need for new effective antifungal agents. Here, we present a strategy based on the in situ generation of radical species that are toxic to the pathogen. The synthesis of an alkoxyamine linked to a peptide substrate recognized by A. fumigatus-secreted dipeptidyl peptidase is described. Kinetic experiments show a stable prodrug prior to enzymatic activation. Ensuing peptide cleavage and spontaneous homolysis resulted in the generation of a stable nitroxide and a reactive alkyl radical moiety. Next, the exposure of A. fumigatus spores to the prodrug lead to pathogen growth inhibition in a compound concentration-dependent fashion (e.g., 42% inhibition at 10 µg/L). Importantly, the designed alkoxyamine inhibited not only the growth of a clinical voriconazole-susceptible A. fumigatus strain, but also the growth of a strain resistant to this azole. To determine the antifungal importance of the reactive alkyl radical, its substitution with a non-radical structure did not prevent A. fumigatus growth. Furthermore, the introduction of succinic group in the peptide substrate resulted in the loss of alkoxyamine antifungal properties. Our work reports a novel chemical strategy for antifungal therapy against A. fumigatus based on the pathogen enzyme-mediated generation of toxic radicals. Significantly, these findings are timely since they could overcome the emerged resistance to conventional drugs that are known to target defined pathogen biologic mechanisms such as ergosterol synthesis. Full article

Candidiasis is a major fungal infection worldwide, with invasive forms linked to high morbidity and mortality. The emergence of azole resistance in Candida parapsilosis causing candidemia led us to examine the epidemiology and antifungal susceptibility of Candida species at the University Hospital of Liège between January 2017 and December 2023. A total of 916 isolates from blood or sterile body fluids, tissues, and abscesses were analyzed. Species identification was performed using MALDI-TOF MS and antifungal susceptibility testing via Sensititre YO10 AST was interpreted according to the CLSI guidelines. Candida albicans remained the predominant species (56%), followed by Nakaseomyces glabratus (19%), Candida parapsilosis (8%), and Candida tropicalis (7%). No significant shift toward non-albicans Candida species (NAC) was observed even during the COVID-19 pandemic, supporting the use of narrow-spectrum empirical therapy in selected patients. Fluconazole susceptibility was high in C. albicans (98.8%), whereas N. glabratus and C. tropicalis showed high resistance rates with 10.1% and 16.9%, respectively. C. parapsilosis showed stable fluconazole susceptibility across the study period. Echinocandins demonstrated excellent activity (95.6–100%), and amphotericin B was effective against nearly all isolates. This seven-year surveillance at the University Hospital of Liège confirms that while C. albicans remains the predominant and highly susceptible species, rising azole resistance in non-albicans Candida—particularly N. glabratus and C. tropicalis—highlights the critical need for ongoing local epidemiological monitoring to guide effective and targeted antifungal therapy. Full article

Fusariosis is an infection caused by the fungus Fusarium spp., which is pathogenic to both plants and humans. The disease presents several clinical manifestations and epidemiological patterns. Current treatment relies on azoles and polyenes, but increasing antifungal resistance requires the exploration of new therapeutic options. This study reviewed patents related to the treatment of Fusariosis from the last 15 years (up to June 2023). The search identified 318 patents, categorized by identification code, publication date, type of application and mechanism of action, using the International Patent Classification and Cooperative Patent Classification systems. In addition, we conducted a bibliographic search in the PubMed database using the same criteria to identify the number of scientific articles. Of the 318 patents, 21 targeted Fusarium infections in humans. The years 2014 and 2018 stood out with three patents each, while the same period recorded an average of 58 published articles. The patents addressed mechanisms such as drug delivery, gene expression, immunotherapy, engineered drugs, and novel compounds. This research highlights the urgent need for continued innovation in therapeutic technologies to effectively treat Fusarium wilt. Full article

To address the surge in Aspergillus fumigatus infections among immunosuppressed patients and azole resistance, this study focused on developing novel inhibitors targeting dihydroorotate dehydrogenase (AfDHODH), a key enzyme in fungal pyrimidine synthesis. The three-dimensional structure of AfDHODH was constructed via homology modeling. Molecular docking, dynamics simulations, and binding free energy calculations systematically elucidated the mechanisms of existing inhibitors. Virtual screening against the ZINC20 and ChEMBL databases yielded 13 candidates, with two micromolar inhibitors (IC₅₀ < 100 μM) identified through in vitro assays. These inhibitors exhibited novel scaffold structures that were distinct from known DHODH inhibitors. The results validate the feasibility of homology modeling-guided antifungal discovery and these findings provide critical insights for the development of new antifungal agents. 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

We report a case of a triazole and echinocandin-resistant C. glabrata right shoulder prosthetic joint infection in a 60-year-old woman. The patient underwent surgery and received the novel triterpenoid antifungal agent ibrexafungerp. She initially improved, but relapsed four months post-treatment. This case highlights the potential role of ibrexafungerp in multidrug-resistant Candida infections. Full article

Previous studies have demonstrated that Candida spp. isolates exposed in vitro to the folic acid antagonist methotrexate may develop multidrug cross-resistance to azole antifungals. The aim of this study was to determine whether systemic therapy with antineoplastic antifolates—pemetrexed or methotrexate—constitutes a risk factor for colonization or infection with fluconazole-resistant yeasts. The study group comprised 44 cancer patients who received high-dose systemic antifolate therapy, while the control group consisted of 48 patients without prior exposure to either methotrexate or pemetrexed. Oral swabs and relevant clinical data were collected from all participants. In total, 109 fungal strains representing 13 species were isolated, identified, and subsequently tested for fluconazole susceptibility. Fluconazole-resistant isolates were identified in 4 out of 44 (9.1%) antifolate-treated patients and in 3 out of 48 (6.3%) control patients. Our findings suggest that, although this phenomenon occurs in vitro, systemic antineoplastic antifolate therapy does not induce azole resistance among endogenous yeast species in vivo. Full article

Aspergillus spp., particularly A. fumigatus, are increasingly reported as emerging pathogens in cetaceans, yet their clinical and ecological relevance remains poorly characterized. This systematic review synthesizes evidence from 34 studies involving 106 animals, identifying respiratory, neurological, and otic infections as the most frequent presentations with potential interspecies tropism. Invasive disease, frequently fatal, was linked to co-infections—especially with morbillivirus—and environmental stressors such as pollution- and climate-related immune suppression. Despite cetaceans’ role as sentinel species, antifungal susceptibility testing and species-level identification were inconsistently performed. Additionally, azole-resistant A. fumigatus strains were isolated from wild porpoises, indicating environmental antifungal exposure and potential public health implications. Aspergillosis remains underdiagnosed in free-ranging populations, particularly in remote or pelagic species. Conservation implications were scarcely addressed, despite evidence suggesting that fungal disease may contribute to morbidity, stranding, and population impact. This review underscores the need for enhanced surveillance, integrative diagnostics, and recognition of fungal pathogens in a One Health framework. The growing intersection of climate change, emerging mycoses, and wildlife conservation positions Aspergillus infections in cetaceans as both a marine mammal health concern and an ecological indicator of broader environmental changes. Full article

Understanding the interplay between antifungal resistance, stress adaptation, and virulence in Aspergillus fumigatus is critical for more effective treatment outcomes. In this study, we investigate six clinical isolates of A. fumigatus from the hospitals of the Czech Republic, focusing on their resistance profiles, stress responses, and survival mechanisms under antifungal pressure. Notably, we have shown that azole-susceptible strains were able to form persister cells under supra-MIC concentrations, highlighting an emerging non-genetic survival mechanism. Stress response profiling demonstrated differential susceptibility to agents targeting signal transduction pathways, as principal component analysis proved that even azole-resistant strains might rely on these pathways. Combinatorial treatment with posaconazole and dithiothreitol enhanced antifungal efficacy regardless of the susceptibility of the strains. Fitness assays revealed that azole resistance imposed a competitive disadvantage in azole-free conditions. In vivo virulence assessment in Galleria mellonella larvae revealed strain-specific pathogenicity that did not directly correlate with resistance. Together, our findings illustrate the multifactorial nature of fungal survival and emphasize that stress adaptation, tolerance, and persistence significantly affect treatment efficacy and outcomes, even in the absence of classical resistance mechanisms. Targeting stress response pathways emerges as a promising strategy to enhance the efficacy of existing antifungal agents and manage resistance in A. fumigatus. Full article