Search Results (470)

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

Candida spp. are important opportunistic human fungal pathogens. This study aimed to identify and characterize Candida spp. obtained from patients admitted to an Intensive Care Unit (ICU), focusing on virulence attributes and susceptibility to antifungal agents. A total of 131 isolates from oral and tracheobronchial secretions of adult ICU patients were evaluated. Phenotypic identification was performed using chromogenic culture media for Candida, followed by MALDI-TOF mass spectrometry, with representative isolates confirmed by ITS sequencing. Antifungal susceptibility to fluconazole, ketoconazole, and amphotericin B was determined only by the agar disk diffusion method, and virulence was assessed through esterase, DNase, protease, and hemolytic activity assays. C. albicans was the prevalent species, followed by C. tropicalis, C. krusei, C. glabrata, C. parapsilosis, C. dubliniensis, C. lusitaniae, and C. guilliermondii. Antifungal resistance rates reached 51.1% for fluconazole, 42.7% for ketoconazole, and 19.1% for amphotericin B, as determined by disk diffusion method. Overall, 64.9% of the isolates exhibited esterase activity, 18.3% DNase, 45.8% protease, and 67.2% exhibited hemolytic activity. Oral isolates were more frequent than tracheal isolates and demonstrated a higher prevalence of antifungal resistance and virulence traits. These findings underscore the epidemiological importance of characterizing Candida species in hospitals to better understand the yeast profile and to support adequate clinical management. Full article

Candidozyma auris (formerly Candida auris) is an emerging multidrug-resistant fungal pathogen with confirmed cases in over 30 countries. Although whole-genome sequencing (WGS) analysis defined distinct clades during characterization of underlying genetic mechanism behind multidrug resistance, Clade II remains under-evaluated. In this study, a three-level comparative genomic strategy (Global, Clade, Phenotype) was employed by integration of unbiased genome-wide comparative SNP screening (GATK v4.1.9.0), targeted BLAST profiling (BLAST+ v2.17.0), and in silico protein analysis (ColabFold v1.5.5; DynaMut2 v2.0) for systematic evaluation of mechanisms of antifungal resistance in thirty-nine Clade II C. auris clinical isolates and fourteen reference strains. Global and clade-level analyses confirmed that all the clinical isolates belong to Clade II, according to phylogenetic clustering and mating type locus (MTL) conservation. At the phenotype level, a distinct subclade of fluconazole-resistant mutants was identified to have a heterogenous network of mutations in seven key enzymes associated with cell membrane dynamics and the metabolic stress response. Among these, four core mutations (TAC1B, CAN2, NIC96, PMA1) were confirmed as functional drivers based on strict criteria during multitier in silico protein analysis: cross-species conservation, surface exposure, active site proximity, thermodynamic stability, and protein interface interaction. On the other hand, three high-level fluconazole-resistant clinical isolates (≥128 μg/mL) that lacked these functional drivers were subjected to comprehensive subtractive genomic profiling analysis. The absence of coding mutations in validated resistance drivers, yeast orthologs, and convergent variants suggests that there is an alternative novel non-coding or regulatory mechanism behind fluconazole resistance. These findings highlight Clade II’s evolutionary divergence into two distinct trajectories towards the development of a high level of fluconazole resistance: canonical protein alteration versus regulatory modulation. Full article

Candidozyma auris (previously named Candida auris) has been recognized as a significant public health threat due to its extensive transmission in hospital settings, high mortality rates, and multidrug resistance. Evidence regarding optimal antifungal treatment in children remains limited. The present systematic review aims to synthesize available evidence on pediatric C. auris infections, focusing on antifungal treatment, resistance profiles, and clinical outcomes. A systematic search was conducted across PubMed, Scopus, and Web of Science, identifying case reports and case series of pediatric patients with confirmed C. auris infection. Data were extracted on demographics, comorbidities, infection site, antifungal therapy, and outcomes. Risk of bias was assessed using JBI Critical Appraisal checklists. Fourteen studies comprising 62 patients were included, with most cases being bloodstream infections. C. auris showed widespread fluconazole resistance and variable susceptibility to amphotericin B. Echinocandins were the most commonly used agents, generally associated with survival. Overall mortality was 35%, similar to that reported for adults. Combination therapy showed numerically higher survival, although given the small sample size and heterogeneity of treatment regimens, no comparative inferences can be made. Pediatric C. auris infections mirror adult patterns of antifungal resistance and mortality. Echinocandins remain first line therapy; however, the emergence of echinocandin resistance underscores the urgent need for antifungal stewardship, standardized pediatric guidelines, and novel antifungal development. Full article

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

The rising global incidence of Candida parapsilosis infections is increasingly complicated by antifungal resistance, resulting in frequent therapeutic failure. This study investigated the potential of the natural compound catechin to enhance the efficacy of fluconazole through synergistic interaction. We evaluated the susceptibility of C. parapsilosis clinical isolates and a reference strain to combinations of catechin and fluconazole using standardized microbiological assays and molecular techniques. In vivo efficacy was assessed using the Galleria mellonella infection model. Mechanistic studies included the measurement of intracellular reactive oxygen species (ROS) production and plasma membrane permeability. Catechin alone caused growth retardation in all strains. However, the combination of catechin and fluconazole resulted in complete growth inhibition of the reference strain and significant growth reduction in azole-resistant clinical isolates. While the combination slightly increased intracellular ROS production, no significant changes in plasma membrane permeability or membrane potential were observed. Notably, catechin induced the expression of the resistance-associated genes CpTAC1 and CpCDR1B in resistant isolates. In vivo experiments demonstrated that catechin significantly reduced mortality in G. mellonella larvae infected with C. parapsilosis. These findings suggest that catechin is a promising candidate for developing synergistic antifungal therapies against resistant Candida species. Full article

Purpose: Candida bloodstream infections remain a major global health challenge, with mortality rates approaching 40%. Beyond classical immunocompromised status, recent evidence highlights additional risk factors, including iatrogenic immunosuppression, advanced age, prolonged hospitalization, exposure to broad-spectrum antibiotics, and total parenteral nutrition. While Candida albicans (C. albicans) remains the most common species in Europe and the USA, non-albicans species, particularly Nakaseomyces glabratus (N. glabratus), Candida tropicalis (C. tropicalis), and Candida parapsilosis (C. parapsilosis), are emerging worldwide. Methods: This retrospective observational cohort study was conducted at the University Hospital “San Giovanni di Dio e Ruggi d’Aragona” in Salerno, Italy, from January 2015 to December 2024. It included all patients with at least one positive blood culture for Candida species. Demographic data, hospital ward of admission, and antifungal susceptibility profiles were collected and analyzed using SPSS software (IBM SPSS Statistics for Mac, version 30 (IBM Corp., Armonk, NY, USA)). Results: The incidence rate is 48.7 new isolates per one thousand patient-days, with a trend of increasing episodes over time among a total of 364 patients. Most cases occurred in medical wards (59.5%), where patients were older (median age 76 (17). C. albicans accounted for 57.9% of isolates, and a significant association was found between species distribution and hospital unit (p < 0.05). Resistance to fluconazole, voriconazole, and amphotericin B increased among C. albicans, with similar trends in N. glabratus and C. parapsilosis. Conclusions: This large single-center cohort highlights both the persistent dominance of C. albicans and the worrisome rise in resistance among C. parapsilosis. Given the aging patient population and increasing antifungal resistance, local epidemiological data are crucial to guide empirical therapy. Our findings underscore the need for multidisciplinary antifungal stewardship programs to optimize personalized treatment strategies and contain the emergence of resistant strains. 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

In the context of evolving antifungal resistance and increasing reports of clinical outbreaks of non-albicans Candida spp. invasive infections, the rapid detection of resistant patterns is of the utmost importance. Currently, an azole-resistant Candida parapsilosis clinical outbreak is ongoing at Pisa University Hospital. Resistant isolates bear both Y132F and S862C amino acid substitutions. Based on the data and isolates retrieved during the clinical outbreak, mass spectrometry was used to investigate the differences between fluconazole-resistant and -susceptible clinical strains directly from yeast colonies isolated from agar culture media. A total of 39 isolates, 16 susceptible and 23 resistant, were included. Spectra were processed following a standardized pipeline. Several supervised machine learning classifiers such as Random Forest, Light Gradient Boosting Machine, and Support Vector Machine, with and without principal component analysis were implemented to discriminate resistant from susceptible isolates. Support Vector Machine with principal component analysis showed the highest sensitivity in detecting fluconazole resistance (100%). Despite these promising results, external prospective validation of the algorithm with a higher number of clinical isolates retrieved from multiple clinical centers is required. 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

Purpureocillium lilacinum is an emerging pathogen that can cause severe ocular infections. This study aimed to investigate the risk factors, clinical manifestations, antifungal susceptibilities, and outcomes of ocular infections caused by P. lilacinum at a large ophthalmic center in Southern China. This retrospective study reviewed the medical records of 34 patients with culture-proven P. lilacinum oculomycosis treated at the Zhongshan Ophthalmic Center from January 2020 to December 2024. The study included 34 patients (17 males, 17 females). The most common risk factor was ocular trauma (38.2%). In vitro susceptibility testing revealed high resistance to fluconazole and caspofungin, but general susceptibility to voriconazole (median MIC 0.25 mg/L). Despite 97.1% of patients receiving voriconazole therapy, outcomes were generally poor, with 54.5% of patients experiencing a poor outcome (vision worse than counting fingers). A significantly shorter time to microbiological diagnosis was associated with a favorable outcome (median 26 days vs. 65 days, p = 0.007). In conclusion, the visual outcomes of this infection remain generally poor, with the major clinical challenge being the delay in diagnosis. Therefore, prompt microbiological investigation is recommended for patients with suspected intraocular infection. Voriconazole remains the first-line therapeutic choice, the therapeutic potential of newer triazoles warrants further investigation. Full article

Functionally similar to a plant vacuole or a mammalian lysosome, the fungal vacuole plays a vital role in many cellular processes. Most studies of the vacuole have been performed in the nonpathogenic yeast Saccharomyces cerevisiae; however, the vacuole in pathogenic fungi has recently been implicated in host invasion in both plants and mammals, highlighting an important role for the vacuole in pathogenesis. Here, we report that deletion of C. neoformans vacuolar protein 8 (VAC8) results in fragmented vacuole morphology, impairment of vacuolar fusion, and inability to form titan cells. Additionally, absence of Vac8 results in defective growth at high temperature and in the presence of caffeine, suggesting a defect in cell wall signaling. Interestingly, despite aberrant vacuole morphology, vac8Δ is slightly more resistant to fluconazole treatment, and displays increased resistance to hydrogen peroxide, suggesting the irregular vacuole morphology does not impair vacuolar function. Like S. cerevisiae Vac8, C. neoformans Vac8 is comprised of armadillo repeat regions which form alpha helices that fold to form a superhelix, allowing for increased protein–protein interaction. Many of the known binding partners of S. cerevisiae Vac8 are not present in the C. neoformans genome, suggesting novel functions for Vac8 in this fungus. Notably, deletion of VAC8 affected some virulence traits, providing support for targeting the fungal vacuole as a potential therapeutic intervention. 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

Background: In Saudi Arabia, rising multi-drug-resistant (MDR) fungal infections from broad-spectrum antifungal overuse highlight the urgent need for epidemiological and susceptibility research. Methods: This cross-sectional study analyzed fungal isolates from 55 patients with positive blood cultures in a Riyadh tertiary hospital, with identification and antifungal susceptibility tested via the VITEK-2 compact system. Results: Candida albicans and non-albicans Candida (NAC) were isolated from 11 and 38 patients, respectively. In the NAC group, C. glabrata and C. parapsilosis spp. were predominant. C. glabrata exhibited the highest resistance to antifungals. Increased rates of resistance were shown by fluconazole and itraconazole, whereas voriconazole was the most effective azole with the lowest resistance. No evidence of resistance was found against non-azole antifungals. A single case of triple resistance to ketoconazole, fluconazole, and itraconazole was observed in C. parapsilosis. A single isolate of C. albicans was resistant to all tested azoles. A rare instance of coinfection with C. glabrata and C. albicans was identified in a single male patient with a dual-resistance pattern against posaconazole and itraconazole. Conclusions: The high prevalence of NAC, including tolerant isolates of C. parapsilosis and C. glabrata, along with multi-azole-resistant C. albicans and unique coinfection scenarios, urgently requires robust antifungal resistance surveillance. Full article

Background: Community-onset fungemia is a clinically significant syndrome frequently linked to recent healthcare exposure and significant morbidity and mortality. Methods: We performed a 21-year, single-centre retrospective cohort of consecutive yeast bloodstream infections diagnosed at the Emergency Department (2004–2024). Clinical/epidemiological data, species identification (MALDI-TOF MS), antifungal susceptibility (CLSI M27; Sensititre YO10), and whole-genome sequencing (WGS) were analyzed. Results: Forty-eight episodes (51 isolates) were included; 56.3% were male, median age 74 years (IQR 63–82). Acquisition was healthcare-associated in 38/48 (79.2%). Sources were unknown (36.7%), abdominal (22.4%), urological (22.4%), catheter-related (14.3%), and 2.1% was attributed to a cardiovascular and a joint focus; 18.8% were polymicrobial. Crude mortality was 20.8% at 7 days (10/48) and 29.2% at 30 days (14/48). Species distribution: Candida albicans 41.2%, Nakaseomyces glabratus 27.5%, Candida parapsilosis 11.8%, Candida tropicalis 11.8%, Pichia kudriavzevii 3.9%, Clavispora lusitaniae 1.9%, and Candida orthopsilosis 1.9%. No isolate was resistant to anidulafungin, micafungin, or amphotericin B; one N. glabratus showed reduced susceptibility to caspofungin. Azole resistance was observed in one C. albicans and one N. glabratus isolate. WGS (44 isolates) confirmed MALDI-TOF identifications and characterized resistance markers. All 12 sequenced N. glabratus carried ERG2 I207V, PDR15/PDH1 E839D, and PDR1 V91I/L98S. Notable cases included one N. glabratus caspofungin-intermediate with FKS2 F659C, N. glabratus fluconazole-resistant with multiple PDR1 substitutions including a unique novel G857V, and C. albicans fluconazole-resistant harbouring alterations in MRR1/MRR2, CDR1, and ERG11. Conclusions: In this 21-year cohort, community-onset fungemia was predominantly healthcare-associated, with C. albicans as the predominant species, followed by N. glabratus. Crude mortality reached 29.2% at 30 days. Echinocandin resistance was not observed; azole resistance was uncommon. WGS provided precise speciation and actionable insight into resistance mechanisms, including a putatively novel PDR1 G857V in N. glabratus. Full article