Search Results (115)

Ovarian cancer stem cells (OvCSCs) are one of the main factors contributing to post-treatment recurrence and the poor prognosis of patients with ovarian cancer. Therefore, the development of therapeutic strategies targeting OvCSCs is needed to improve patient survival. We previously reported the high expression of survivin/BIRC5 in OvCSCs and also that targeting pathways regulating survivin expression effectively suppressed OvCSC survival. In the present study, we tested a panel of agents consisting of FDA-approved drugs and compounds under clinical studies for their ability to suppress survivin expression in OvCSCs and identified clotrimazole (CTZ) as a potent candidate. The effects of CTZ on survivin expression were examined by RT-PCR and Western blot analyses. The effects of CTZ alone or in combination with anticancer agents on OvCSCs were evaluated using WST-8, PI uptake, and colony formation assays. CTZ preferentially impaired OvCSC survival by suppressing the c-myc–survivin axis without affecting normal fibroblasts and enhanced the efficacy of platinum- and taxane-based chemotherapeutic agents. These results suggest that CTZ suppresses survivin expression in OvCSCs and enhances the effects of conventional ovarian cancer chemotherapeutic agents, supporting further investigations of this approach as a potential strategy for ovarian cancer treatment. Full article

Background/Objectives: Otomycosis is a recurrent fungal infection of the external auditory canal. This disease is difficult to manage with current antifungal agents due to irritation, ototoxicity risk, and emerging resistance. Natural essential oils have been proposed as alternatives, yet their clinical application in otic formulations remains limited due to their poor solubility and stability. In this study, we report the first ear-drop formulation combining microemulsified Ocimum gratissimum essential oil and acetic acid for otomycosis treatment. Methods: The essential oil was quality-validated with eugenol content superior to 60%. A systematic formulation study was performed, and the Tween 20/isopropanol (4:1, w/w) mixture was selected as the optimal surfactant system, yielding a stable microemulsion with high encapsulation efficiency (~98%) and relevant physicochemical stability (up to 28 days). The final formulation containing 1% acetic acid and 0.3% micro-emulsified essential oil met pharmacopeial requirements in terms of appearance, pH, viscosity, and microbial limits. Results: Importantly, this micro-emulsified eardrop demonstrated significantly greater in vitro antifungal activity than 3% boric acid and 2% acetic acid eardrops in twelve clinical fungal isolates from Vietnamese swimmers, especially on Curvularia, Cunninghamella, Aspergillus terreus, and Bipolaris. Although less pronounced than 1% clotrimazole, the finalized formulation demonstrates better antifungal kinetics and a broader activity spectrum. Conclusions: This work provides relevant experimental evidence on the use of Ocimum gratissimum essential oil in a microemulsion delivery system and demonstrates its efficacy against clinically relevant otomycosis pathogens. The results establish a foundation for future in vivo and clinical studies. Full article

Malassezia are commensal lipid dependent yeasts which can cause opportunistic skin infection. Topical imidazole antifungals such as clotrimazole and ketoconazole are the frontline treatment. However, the tendency of fungal infections to recur, combined with the emergence of multi-azole-resistant Malassezia isolates means that many patients have used these antifungal treatments repeatedly or for extended durations with limited efficacy. While the impact of single azole treatments has been studied, the ability of specific azoles to induce cross-resistance is unclear. Understanding the effect of prior exposure of one treatment on susceptibility to other antifungals is important in the selection of the appropriate treatment to avoid driving the evolution of greater resistance. We previously identified drug transporters from the ATP-Binding Cassette (ABC) and Major Facilitator Superfamily (MFS) to be upregulated on extended exposure to clotrimazole. In this study, we investigated the effect of extended clotrimazole, ketoconazole and fluconazole exposure on antifungal cross-resistance profiles and examined the expression of the MFS transporters OPT1 and FLR1 in resistance emergence. We observed that treatment with clotrimazole was associated with increased cross-resistance to other antifungals. Ketoconazole treatment caused elevated MICs in all tested antifungals that did not decrease after drug removal. These findings advance our understanding of fungal adaptive resistance mechanisms and inform improved antifungal strategies to mitigate resistance development. Full article

Vulvovaginal candidiasis (VVC) is a common fungal infection among reproductive-age women and is increasingly challenged by the emergence of non-albicans Candida species and reduced azole susceptibility. This prospective cross-sectional study investigated 235 symptomatic reproductive-age women attending two healthcare facilities in Ho Chi Minh City, Vietnam, to determine VVC prevalence, Candida species distribution, pregnancy-associated patterns, antifungal susceptibility, and diagnostic performance. Vaginal swabs were cultured on Sabouraud Dextrose Agar and CHROMagar™ Candida, while species identification was confirmed by PCR-RFLP targeting the ITS region. Susceptibility to fluconazole and clotrimazole was assessed using the disk diffusion method. Candida spp. was detected in 55.7% of participants. C. albicans accounted for 50.3% of isolates, whereas non-albicans Candida species represented 49.7%, indicating a substantial species shift. VVC was more frequent among pregnant women, particularly in the third trimester. Most C. albicans, C. tropicalis, and C. parapsilosis isolates remained susceptible to azoles; however, C. glabrata showed markedly reduced susceptibility to fluconazole and clotrimazole. CHROMagar™ Candida reliably identified C. albicans but misclassified several non-albicans Candida isolates compared with PCR-RFLP. These findings highlight the need for routine species-level diagnosis, antifungal susceptibility testing, and strengthened VVC surveillance in reproductive and antenatal healthcare settings in Vietnam. Full article

Yeasts have attracted increasing attention as potential alternatives to traditional bacterial probiotic strains due to their physiological resilience and functional versatility. However, the probiotic potential of yeast strains associated with Mexican cocoa bean fermentation remains largely unexplored. Therefore, this study aimed to conduct a preliminary screening of physiological and surface-related traits associated with probiotic functionality in four autochthonous Saccharomyces cerevisiae strains (YCTA5, YCTA9, YCTA14, and YCTA16), previously isolated from cocoa fermentation, using Saccharomyces boulardii (Jarrow Formulas^®) as a reference strain. Evaluated parameters included tolerance to temperature, pH, and bile salts; hemolytic activity; survival in vitro under gastrointestinal (GI) conditions; bile salt hydrolase activity; auto-aggregation; co-aggregation; hydrophobicity; and response to antifungal agents (fluconazole, ciclopirox, nystatin, and clotrimazole). All yeast strains grew at 37 °C and at pH 4–8 and showed no hemolytic activity. All strains exhibited high auto-aggregation (>70%) and hydrophobicity values ranging from 55 to 88%. In the coaggregation assay, strains YCTA9, YCTA14, and YCTA16 showed moderate interactions with Escherichia coli, Bacillus cereus, and Listeria innocua, with some combinations exceeding 50%. Nevertheless, none of the yeast strains exhibited measurable growth at pH 2; bile salt tolerance was limited to 0.1% Oxgall, and viability decreased by approximately 54–56% after simulated gastrointestinal transit. These findings indicate that although some strains exhibited promising surface-related properties, significant physiological constraints restrict their probiotic potential under the tested conditions. Therefore, the studied yeast strains should be regarded as preliminary candidates requiring further validation. This work provides a first-stage evaluation for identifying functional yeast strains from Mexican cocoa bean fermentation, serving as a basis for future in vitro and in vivo studies. Full article

Candida species can shift from commensal organisms to opportunistic pathogens. Both Candida albicans and non-albicans Candida (NAC) species colonize oral biofilms and periodontal pockets, where they may contribute to inflammation and the progression of periodontal disease. This study aimed to determine the prevalence and antifungal susceptibility profiles of Candida species in individuals with different stages of periodontal disease. A cross-sectional study was conducted in 100 participants whose periodontal status was clinically evaluated. Saliva samples were cultured on chromogenic agar for yeast isolation, species identification was confirmed by MALDI-TOF MS, and antifungal susceptibility to fluconazole, clotrimazole, nystatin, and amphotericin B was assessed. Candida spp. was detected in 35% of participants, where C. albicans was the most prevalent species, followed by Nakaseomyces glabratus (formerly Candida glabrata), Candida parapsilosis, Candida dubliniensis, and Candida tropicalis. Species distribution varied according to periodontal status, with N. glabratus predominating in early periodontitis and C. albicans appeared more frequently in higher severe stages of periodontitis. Susceptibility testing showed resistance of C. albicans to clotrimazole (63.6%) and nystatin (22.7%), whereas amphotericin B and fluconazole remained effective. NAC species, particularly N. glabratus, exhibited resistance to nystatin and variable resistance to clotrimazole but remained susceptible to amphotericin B. These findings underscore the importance of early detection and personalized antifungal strategies for managing periodontal disease complicated by Candida colonization. Full article

Background/Objectives: Inclusion complexes among drugs and cyclodextrin-modified polymers are a topic of recent interest in pharmaceutical research and industry as they might expand the solubility, bioavailability, and stability of the guest molecules. Polyurethanes derived from cyclodextrins show some biomedical applications. In this study, two cross-linked polyurethane networks based on hydroxypropyl-β-cyclodextrin (HPβCD) and polyethylene glycols (PEG 2000 or PEG 6000) were synthesized with NCO/OH molar ratio 4.3 and 6.3 by the typical two-step polymerization method. Methods: Inclusion complexes of clotrimazole (CLOT) with two HPβCD-modified polyurethane networks and their corresponding physical mixtures were prepared using kneading methods and physical mixing in a 1:6 weight ratio of CLOT:HPβCD. Results: Obtained prepolymers, previously end-capped with isocyanate groups forming urethane links with HPβCD, which were confirmed by FTIR analysis. TGA results indicate a slight increase in thermal stability of the prepared complexes. The characteristic endothermic peak of the CLOT at around 145.90 °C did not appear in the DSC curve of the drug-loaded inclusion complexes. The XRD patterns of physical mixtures showed specific peaks corresponding to pure clotrimazole. SEM micrographs confirmed an elliptical/spherical- and plate-shaped particles without phase segregation, indirectly confirming that CLOT is not separately present due to inclusion into HPβCD and entrapment into polyurethane networks. Novel complexes PUR2/HPβCD-CLOT-IC and PUR3/HPβCD-CLOT-IC were applied as drug carriers, and diffusion-controlled kinetics of CLOT release were best described using Higuchi model. Conclusions: The obtained in vitro results showed surprisingly slow/prolonged clotrimazole release from modified polyurethane networks due to the significant influence of NCO/OH molar ratio and the chosen polyol soft segments chain length with potential in vivo applications. Full article

Sterol regulatory element-binding proteins (SREBPs) regulate lipid homeostasis and coordinate sterol metabolism and carotenogenesis in the astaxanthin-producing yeast Phaffia rhodozyma. While Sre1, the SREBP ortholog, and the site-2 protease Stp1 have been identified as essential components of this pathway in P. rhodozyma, additional factors involved in Sre1 processing or regulation remain unknown. In Aspergillus species, a signal peptide peptidase contributes to the activation of the SREBP ortholog, raising the possibility of a similar role in this yeast. In this work, we identified and characterized the P. rhodozyma signal peptide peptidase (SppA) homolog. Sequence analysis, domain prediction, and phylogenetic analyses supported its classification within the SPP family of intramembrane aspartyl proteases. To evaluate its functional role, ΔsppA mutants were constructed in genetic backgrounds with constitutive Sre1 activity, including the cyp61⁻ mutant and a strain expressing the active form of Sre1 (Sre1N). Deletion of SPPA did not alter sensitivity to clotrimazole or cobalt chloride, nor affect pigmentation, indicating that SppA is not required for Sre1 activation in P. rhodozyma. Transcriptomic analyses further showed that expression of SRE1 and of its known target genes remained unchanged upon SPPA deletion. Interestingly, the loss of SppA in the Sre1N background caused marked downregulation of genes associated with protein refolding and unfolded protein binding. In agreement with these transcriptional changes, the Sre1NΔsppA strain displayed increased sensitivity to dithiothreitol. These findings suggest that, although SppA is not involved in Sre1 activation in P. rhodozyma, it may play a role in protein stress-related processes. Future studies will be required to define the molecular mechanisms underlying this role and its integration with protein homeostasis networks. Full article

Sterol regulatory element-binding proteins (SREBPs) are transcription factors that regulate lipid homeostasis and have been associated with hypoxia adaptation in fungi. In the yeast Phaffia rhodozyma, the SREBP ortholog named Sre1 regulates sterol biosynthesis, but its contribution to stress-responsive transcriptional programs remains poorly understood. We performed RNA-seq analyses to evaluate the transcriptional responses of wild-type (WT) and ∆sre1 mutant strains exposed to hypoxia, cobalt chloride (CoCl₂), and clotrimazole treatments. Differentially expressed genes (DEGs) were analyzed using KEGG mapping to assess the treatment-induced transcriptional changes in both strains and to evaluate the potential contribution of Sre1 to these responses. In the WT strain, hypoxia induced the most extensive transcriptional changes, while CoCl₂ elicited a moderate response partially overlapping with hypoxia. Downregulated DEGs predominated in both conditions, and all CoCl₂-associated KEGG pathways were also identified under hypoxia. In contrast, the Δsre1 mutant showed an increased number of DEGs in response to clotrimazole and CoCl₂, with most clotrimazole-responsive genes being mutant-specific, indicating distinct Sre1-associated transcriptional responses under these conditions. Shared downregulated DEGs under CoCl₂ and hypoxia suggest that basal Sre1 activity may contribute to modulation of gene expression programs related to core cellular processes. However, Sre1-dependent regulation alone did not account for the extensive transcriptional reprogramming observed under the applied hypoxic treatment. Full article

Background: Clotrimazole (CLZ) is an approved antifungal with reported pleiotropic effects. Beyond its antifungal use, CLZ can perturb glycolytic flux and ionic homeostasis, motivating its evaluation as a repurposing candidate in oncology. Objective: We aimed to evaluate CLZ and nitazoxanide (NTZ) as drug repurposing candidates for pancreatic ductal adenocarcinoma (PDAC) in comparison with standard chemotherapeutics gemcitabine (GEM) and 5-fluorouracil (5-FU). Methods: T3M4 PDAC cells were treated (0.1–100 µM; 48–72 h) with 5-FU, GEM, CLZ, and NTZ. Cell viability (MTT) and morphology were assessed, and CLZ-based combinations were analyzed by the Chou–Talalay method. In silico studies provided physicochemical descriptors and ADMET profiles, along with predicted interactions with relevant bioorganic targets (e.g., KCa3.1/KCNN4 ion channels). Results: CLZ produced marked cytotoxicity at 72 h (IC₅₀ ≈ 9 µM) and achieved a greater reduction in cell viability at higher concentrations compared to 5-FU and GEM under identical conditions, whereas NTZ showed modest and inconsistent effects. CLZ combinations with 5-FU or GEM were mainly antagonistic. In silico analyses indicated high membrane permeability and suggested potential interactions with KCa3.1, supporting a hypothesis-generating interpretation of the observed in vitro effects. Conclusions: Within a drug repurposing framework, CLZ exhibited consistent cytotoxic activity as a single agent in a PDAC cell model, whereas NTZ revealed limited effects and CLZ-based combinations were not beneficial under the tested conditions. These findings position CLZ as a monotherapy-oriented repurposing candidate for PDAC and motivate further mechanistic and translational studies to clarify the biological basis of its in vitro activity. Full article

Fungal mastitis is rare but poses a significant problem for dairy farmers. It is often underestimated and under-researched, with most studies and treatments focusing on bacterial infections. Antibiotics are ineffective against fungi, and they exacerbate fungal mastitis. This study aimed to determine the antifungal properties of silver (Ag), gold (Au), copper (Cu), iron with a hydrophilic carbon coating (FeC), and platinum (Pt) nanoparticles (NPs) at five different concentrations, as well as their complexes, on the survival of fungal strains such as Pichia kudriavzevii, Wickerhamiella pararugosa, Saccharomyces cerevisiae, Cutaneotrichosporon mucoides, Wickerhamomyces anomalus, Coniochaeta hoffmannii, and Kluyveromyces marxianus. The strains’ susceptibility to 8 standard antifungals, along with MIC (minimal inhibitory concentration) and MFC (minimal fungicidal concentration) after NP treatment, was assessed. Clotrimazole and ketoconazole (10 µg) were most effective, while fluconazole (10 µg) and flucytosine (1 µg) showed the weakest activity. The AgCuNP complex demonstrated the strongest biocidal activity against all isolated strains, while FeCNPs and PtNPs showed very weak or no biocidal properties. The study’s results provide a basis for further in vivo research, indicating the great potential of nanoparticles in combating fungal mastitis, providing an innovative solution against infections caused by drug-resistant pathogens. Full article

P-glycoprotein (P-gp) is an ATP-dependent efflux transporter that contributes to cellular defense by exporting xenobiotics. While well characterized in mammals, its inducibility and physiological regulation in fish remain poorly understood. This study examined the functional induction of P-gp in juvenile rainbow trout (Oncorhynchus mykiss) hepatocytes following xenobiotic exposure and assessed how energy status (fed vs. fasted) influences both basal and inducible efflux activity. In vivo exposure to clotrimazole, dexamethasone, benzo[a]pyrene, and rifampicin significantly reduced rhodamine 123 (R123) accumulation in hepatocytes, indicating enhanced P-gp activity. Clotrimazole elicited the strongest response, with effects evident by day 3. Induction was dose-dependent and plateaued at doses ≥ 4 mg/kg. A single injection produced transient P-gp activity, while repeated exposures sustained efflux for 28 days. Fasting led to increased R123 accumulation, indicating suppressed basal P-gp function, though inducibility was retained but attenuated. These findings confirm that P-gp is inducible in trout and modulated by nutritional state. This functional plasticity has ecological relevance, as contaminant exposure during energetically limited periods (e.g., migration, overwintering) may compromise chemical defense. Understanding these trade-offs is key to assessing the resilience of wild fish to pollution stressors. Full article

(1) Background: Meyerozyma guilliermondii is a yeast species widely distributed in the natural environment and one of the rare emerging pathogens capable of causing difficult to treat, severe infections. The species’ susceptibility profile is not fully defined; however, the species could be more prone to develop resistance than other Candida species. The objective of this research was to determine the susceptibility of a local collection of Meyerozyma guilliermondii clinical isolates to classical antifungal drugs as well as a new one—manogepix. (2) Methods: The study included 20 clinical isolates identified using the MALDI–TOF method followed with sequencing of ITS1-2 region of DNA. Overall, the susceptibility to 12 antifungal drugs was tested. Nine drugs (amphotericin B, flucytosine, fluconazole, itraconazole, posaconazole, voriconazole, anidulafungin, caspofungin, and micafungin) were assessed using the MICRONAUT–AT test. The susceptibility to the new drug, manogepix, as well as isavuconazole, clotrimazole and anidulafungin, was determined using the microdilution method recommended by EUCAST. Additionally, anidulafungin and voriconazole MIC was also examined with commercial gradient tests. (3) Results: Overall, the isolates showed low MIC values for amphotericin B (0.125 to 1 mg/L) and for flucytosine (≤0.06 to 32 mg/L), with the exception of one isolate with a high MIC value. The MIC ranges for azoles were 2–64 mg/L (fluconazole), 0.008–0.5 mg/L (voriconazole), ≤0.03–≥4 mg/L (itraconazole) and 0.008–0.5 mg/L (posaconazole). One isolate showed non-WT phenotype to all tested azoles. For anidulafungin, the MIC values ranged from ≤0.06 to 0.25 mg/L; however, in the reference method, higher values were observed, but they did not exceed 2 mg/L (ECOFF value). For manogepix, the MIC values ranged from 0.002 to 0.125 mg/L. Finally, the comparison of the obtained and published susceptibility data was conducted. (4) Conclusions: The data obtained in this study are consistent with reports by other authors and indicate that resistance to azoles or 5-fluorocytosine among clinical isolates of Meyerozyma guilliermondii should be considered. The low MIC values of manogepix suggest the potentially good efficacy of this drug against Meyerozyma guilliermondii species. Full article

Vulvovaginal candidiasis (VVC) represents a widespread gynaecological challenge, affecting approximately 75% of women at some point during their reproductive years, with a significant subset progressing to recurrent forms (RVVC). Classical azoles and polyenes remain the cornerstone of therapy. However, their clinical utility is undermined by the rise of azole-resistant non-Candida albicans species, the capacity of Candida to form biofilms, and a complex variety of host-related factors that complicate disease expression and therapeutic response. This narrative review provides a critical up-to-date examination of the therapeutic landscape, integrating current diagnostic algorithms with pharmacological strategies for both acute, recalcitrant and recurrent VVCs. We assess the efficacy and safety of established antifungal agents alongside the breakthrough introduction of novel drug classes, with a particular interest in the oral triterpenoid ibrexafungerp and the tetrazole oteseconazole, which offer new mechanisms of action for cases that fail to respond to standard regimens. Furthermore, we address the management of a special clinical scenarios, including pregnancy and lactation, and explore promising emerging innovative approaches such as mucoadhesive formulations, immunomodulatory approaches, and alternative non-antifungal therapies. Ultimately, this review aims to support clinical decision-making by balancing the accessibility and user-friendliness of conventional treatments with the targeted precision offered by modern antifungal agents. Full article

Genitourinary infections caused by Candida spp. and other yeasts have increased in incidence, and the emergence of resistant isolates to commonly prescribed antifungals is becoming more frequent. Thus, the purpose of this study was to characterize the physiological characteristics of 38 yeast isolates (Candida albicans [n = 32], Candida tropicalis [n = 3], and Nakaseomyces glabratus [n = 3]) recovered from genitourinary infections to better understand the diversity of their physiological profiles, their virulence factors, and their role in pathogenicity. In addition, an experimental study was conducted to determine the minimum inhibitory concentration (MIC) of the isolates using the M27-A3 microdilution method described by the Clinical Laboratory and Standards Institute. Clinical isolates of Candida spp. studied showed in vitro susceptibility to both fluconazole and clotrimazole, the latter having greater antifungal activity due to its lower MIC₅₀. Statistically significant differences were found between the MICs obtained for fluconazole and clotrimazole, with the latter showing the highest in vitro activity. Therefore, the clinical use of clotrimazole is recommended, as is the ongoing need for this type of analysis to monitor changes in susceptibility profiles over time. Full article