Search Results (431)

Background: In the last decade, infections caused by Candida species have increased. Although C. albicans remains the most predominant species, fungal infections caused by non-albicans Candida (NAC) species have also been rising. This study aimed to determine which Candida spp. are most frequently associated with oral candidiasis. Methods: In accordance with PRISMA guidelines, a literature search was conducted in the PubMed, Cochrane Library, and ScienceDirect databases. The search used the keyword combination “candida spp” AND “oral candidiasis” AND “oral isolates” and included articles published between 2013 and 31 October 2025. Results: A total of 658 articles were identified, of which 24 met the inclusion criteria. Across these studies, 12,750 isolates were reported. C. albicans was the most prevalent species, accounting for 81.7% of all isolates. NAC species were detected at lower frequencies, including C. tropicalis (7.2%), C. glabrata (4.5%), C. krusei (4.1%), C. parapsilosis (1.0%), C. dubliniensis (0.8%), C. kefyr (0.2%), C. guilliermondii (0.1%), C. lusitaniae (0.1%), and other rare or unidentified species (0.2%). The increasing prevalence of Candida infections is associated with a growing population of immunocompromised individuals, and treatment remains challenging due to rising antifungal resistance. Conclusions: Although C. albicans remains the most prevalent, the appearance of NAC species is gradually increasing. With the increase of Candida spp. resistant to conventional antifungal agents and with the competitive or synergistic interaction between Candida spp., it is necessary to develop new therapeutic approaches. 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

Blood culture remains the gold standard for identifying bloodstream infections caused by bacteria and fungi. Isolation of the culprit microorganism onto agar plates also facilitates antimicrobial susceptibility testing. The purpose of this study was to determine the contamination rates, pathogen profile, and antimicrobial resistance in a secondary healthcare setting in a two-year timeframe. In this study, data regarding blood cultures of the years 2023 and 2024 were retrospectively analyzed to address the above questions. Blood cultures were incubated for seven days before being discarded as negative. The percentage of positive blood cultures for both years was 14.3%. Most positive cultures contained Gram-positive cocci, with a prevalence of coagulase-negative Staphylococci. In descending order, 72.72% were coagulase-negative Staphylococci, 15.15% were Staphylococcus aureus, and 12.12% were Streptococci. One strain of S. aureus was methicillin-resistant (MRSA), and one strain of Enterococcus faecium was vancomycin-resistant (VRE). Of the Gram-negative rods, 78.3% were Enterobacterales. Of these, Escherichia coli, Klebsiella pneumoniae, and Proteus mirabilis were the top pathogens. The remainder comprised eight strains of Pseudomonas aeruginosa, four strains of Acinetobacter baumannii (one pandrug-resistant), three strains of Stenotrophomonas maltophilia, one strain of Sphingomonas paucimobilis, and one strain of Campylobacter jejuni. The isolated fungi comprised Candida parapsilosis, Candida glabrata, and Candida tropicalis. Of the isolated Escherichia coli strains, 39.5% were resistant to ciprofloxacin regardless of origin (outpatient or hospitalized patients). Outpatient samples were taken in a Hemodialysis Unit that collaborates with our laboratory, obtained from patients with fever or other signs of infection. Distinguishing true bacteremia from contamination remains challenging. The contamination rate in our study was quite high at 5.3%. Since there is no dedicated phlebotomy team in our healthcare setting, in light of our results, educational courses have been conducted to demonstrate the best practices for sample collection. 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

Background/Objectives: Fingernail onychomycosis differs etiologically and epidemiologically from toenail infections and is frequently complicated by colonization and mixed growth. Reliable interpretation of microscopy–culture correlations is essential for avoiding overdiagnosis and guiding therapy. This study aimed to characterize the diagnostic structure, species distribution, and antifungal susceptibility patterns of fingernail onychomycosis in a large routine-laboratory cohort, and to evaluate the performance of a five-tier operational classification integrating microscopy and semi-quantitative culture. Methods: Laboratory records from 1075 patients with clinically suspected fingernail onychomycosis (including nail and periungual samples) were analyzed retrospectively (2017–2024). Direct microscopy with calcofluor white, semi-quantitative culture, and MALDI-TOF MS identification were performed. Cases were categorized based on predefined criteria combining microscopic elements with colony quantity and purity. Species distribution, age–sex patterns, diagnostic concordance between microscopy and culture, and results of EUCAST broth microdilution testing for selected yeasts were assessed. Results: The overall proportion of mycologically positive cases was similar in women and men, although age-dependent patterns differed. Microscopic findings correlated with culture outcomes, with hyphae predicting dermatophytes, yeast cells predicting ascomycetous yeasts, and negative slides aligning with the absence of growth. Yeasts predominated (Candida parapsilosis 30.9%, C. albicans 18.5%), dermatophytes were mainly Trichophyton rubrum, and molds were uncommon. Periungual swabs showed species distributions closely matching those from nail samples and demonstrated high analytical concordance. EUCAST MICs revealed species-dependent variation, including elevated amorolfine MICs in C. parapsilosis and reduced fluconazole activity in Wickerhamomyces pararugosa. Conclusions: Fingernail onychomycosis in this cohort was predominantly yeast-associated, with predictable microscopy–culture relationships and distinct age–sex patterns. The five-tier operational framework improved classification of infection versus colonization, and is proposed as a preliminary tool requiring clinical validation, while contemporary MIC data highlighted clinically relevant interspecies differences. The absence of clinical correlation data (symptoms, severity, treatment history) remains the primary limitation, preventing definitive distinction between infection and colonization in all cases. 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

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

Background/Objectives: Candida biofilms exhibit high resistance to antifungal treatment, motivating investigation of adjunctive physical disinfection methods. To quantitatively assess the effect of Er:YAG laser fluence on growth inhibition and viability of single-species Candida biofilms in vitro using a 7 mm full-beam handpiece. Methods: Biofilms of Candida albicans ATCC 10231, C. glabrata ATCC 90030, C. parapsilosis ATCC 22019, and C. krusei ATCC 6258 were grown on Sabouraud agar. In phase 1, growth inhibition zones (GIZs) were evaluated after non-contact Er:YAG irradiation (2 Hz, 300 µs, 10 mm distance, no air or water spray) at fluences from 0.3 to 3.4 J/cm², with incubation for 24 to 96 h. In phase 2, 96 h mature biofilms were irradiated for 120 s at 0.8, 1.0, 1.5, or 2.0 J/cm², and viability was quantified by colony-forming unit (CFU) imprinting. All experimental conditions were tested in quadruplicate. Results: GIZ diameters increased significantly with fluence for all species (p < 0.05) and remained stable up to 96 h. At the highest fluence, mean GIZs reached approximately 8.0 mm for C. albicans, 7.7 mm for C. parapsilosis, 7.0 mm for C. krusei, and 5.2 mm for C. glaxfbrata. In mature biofilms, CFU counts decreased significantly with increasing fluence (p < 0.05). For C. albicans, CFUs were reduced from 164.0 ± 25.1 at 0.8 J/cm² to 16.5 ± 5.2 at 2.0 J/cm², while C. glabrata decreased from 103.5 ± 5.4 to 20.8 ± 1.7. C. parapsilosis and C. krusei showed maximal reductions at 1.0–1.5 J/cm², followed by partial CFU rebound at 2.0 J/cm². Conclusions: Er:YAG irradiation delivered over a large, uniformly illuminated area induces stable, fluence-dependent inhibition and significant reduction of Candida biofilm viability in vitro. Optimal fluence ranges are species specific, underscoring the need for parameter optimization and further evaluation in more complex biofilm models before clinical extrapolation. 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

Background: Surface contamination in healthcare environments plays a key role in the persistence and transmission of microorganisms. Long-lasting antimicrobial coatings based on copper–polymer complexes offer a promising passive strategy to minimize environmental contamination and healthcare-associated infections. Methods: This study evaluated a copper-alloy polymeric tape through physicochemical, in vitro, and hospital-based assessments. Structural analyses (XRD, Raman, SEM, EDX) were used to characterize the material, while antimicrobial efficacy was determined against Gram-positive and Gram-negative bacteria following ISO 22196:2011. A randomized 19-week clinical study was conducted in the Emergency and Urgent Unit of the University Hospital of Brasília to quantify microbial loads on high-touch surfaces covered with the copper-alloy tape or a non-antimicrobial control. Results: Structural characterization techniques validated the integrity and heterogeneous distribution of copper within the polymeric matrix. All tested bacterial strains exhibited complete growth inhibition on the copper-alloy tape, with final counts consistently below the detection threshold (<1.00 log10 CFU/mL). Human keratinocytes analyzed by SEM showed preserved morphology. In hospital conditions, treated surfaces maintained significantly lower microbial loads than controls over 19 weeks. The number of yeast-positive samples was small compared to the total number of samples collected during the study, but Candida parapsilosis was the most frequently identified species. Conclusions: These findings support its use as a sustainable intervention to reduce environmental contamination and infection risks in healthcare settings. Full article

Background/Objectives: Fungal keratitis (FK) is a current challenge in ophthalmology due to its association with severe visual impairment and the limitations of current antifungal therapies. We aim to evaluate the antifungal activity of essential oils (EOs) from the aromatic and medicinal plants Cymbopogon citratus and Lavandula pedunculata against selected FK pathogens collected from FK patients in two Portuguese hospitals. Methods: The antifungal activity of the EOs was tested at concentrations of 25%, 50%, 75%, and 100% for up to 7 days using the solid-phase disk diffusion in vitro assay. Results: Candida albicans was the most prevalent pathogen (28.6%), followed by Candida parapsilosis (21.4%) and Dicyma olivacea (14.2%). The other identified species were Aspergillus fumigatus and Scedosporium boydii (7.1%). Clinical diagnostic methodologies showed agreement with the molecular identification. Cymbopogon citratus EO showed higher antifungal activity than Lavandula pedunculata EO. The highest antifungal activity was observed against Aspergillus fumigatus and Scedosporium boydii (inhibition zone diameter, IZD = 90.0 mm) after 7 (Cymbopogon citratus EO) or 3 days of incubation (Lavandula pedunculata EO). While the antifungal activity of Cymbopogon citratus EO was maintained during the study (for Aspergillus fumigatus, Candida albicans, and Scedosporium boydii), the antifungal activity of Lavandula pedunculata EO decreased with time. Conclusions: Cymbopogon citratus EO and Lavandula pedunculata EO showed optimal antifungal activity against molds (Aspergillus fumigatus and Scedosporium boydii) after 3 days of incubation. Against yeasts (Candida albicans and Candida parapsilosis), the EOs showed lower activity. Our study sheds light on the development of new pharmacological strategies for FK based on EOs extracted from aromatic and medicinal plants. Full article

Amphotericin: B (AmpB)-resistant Candida (C.) species, such as C. parapsilosis, are among the most common causes of invasive fungal infections, posing significant challenges in hospital settings. Although AmpB is considered the first-line treatment owing to its broad-spectrum fungicidal activity, its use is hampered by severe side effects and the emergence of acquired resistance, particularly in C. parapsilosis, which exhibits reduced susceptibility to polyene, azole, and echinocandin-based antifungal drugs. Here, we present findings on photodynamic therapy (PDT) that targets the opportunistic fungal pathogens C. parapsilosis and C. albicans via the use of photosensitizers from the iodocyanine and newly developed iodinated Methylene blue families. These compounds contain heavy iodine atoms that increase the production of reactive oxygen species (ROS), the agents responsible for oxidative cellular damage, via the heavy-atom effect, which promotes intersystem crossing (ISC) and triplet-state formation. A strong antifungal effect was observed against AmpB-resistant C. parapsilosis, indicating a correlation between the quantum yield of ROS generation and the photosensitizing efficacy under near-infrared (NIR) light irradiation. The combination of efficient cellular uptake and enhanced ROS generation positions iodinated photosensitizers as promising candidates for the treatment of drug-resistant Candida strains. 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

Candida and other pathogenic yeast species, able to transition from non-invasive commensal organisms to invasive pathogens, are characterized by a high ability to adapt to stress conditions encountered in the human host, such as pH and temperature shifts, CO₂ and oxygen level variations, and nutritional limitations. Although Candida albicans remains the main cause of Candida-related infections, non-albicans Candida (NAC) species, including C. tropicalis, C. parapsilosis, C. krusei, and non-Candida species such as Yarrowia lipolytica, Candidozyma auris, and Nakaseomyces glabratus, are gaining clinical importance. These species exhibit diverse mechanisms of pathogenicity, including morphological transition, modulation of gene expression pathways (cAMP-PKA/MAPK, Hsp, calcineurin, GlcNAc-mediated signaling), cell wall remodeling, post-translational reprogramming, biofilm formation, antifungal resistance, and enzyme secretion. C. albicans exhibits high morphological and metabolic plasticity for survival across body niches. N. glabratus and C. tropicalis show strong azole resistance and biofilm formation, while C. parapsilosis and C. krusei pose risks through surface adhesion and treatment resistance. C. auris stands out for heat tolerance, multidrug resistance, and outbreak potential. Y. lipolytica, though rare, forms persistent filamentous biofilms in critical care settings. Cryptococcus neoformans remains a life-threatening pathogen capable of immune evasion and crossing the blood–brain barrier. This review compares molecular mechanisms of pathogenicity across these fungi, emphasizing environmental adaptation, conserved and species-specific responses, and potentially highlighting targets for therapeutic management. Full article

Inflammatory bowel diseases (IBDs), including Crohn’s disease and ulcerative colitis, are chronic inflammatory disorders of the gastrointestinal tract, and current therapies are limited by adverse side effects. Combretum micranthum G. Don (kinkeliba), a medicinal plant traditionally used in West Africa, has been reported to possess pharmacological activities and a favorable safety profile. In this study, an ethanolic extract of Combretum micranthum (EECM) was characterized using HPLC-DAD-ESI-MS to identify its phenolic constituents. Acute colitis was induced in C57BL/6 mice using 3% DSS, while EECM (100 and 200 mg/kg) was administered orally for seven days. Disease Activity Index was monitored daily, and colonic injuries were evaluated through macroscopic and histological analyses, as well as hematological and biochemical assessments. In vitro, EECM contained 293.54 mg/g of total phenolic compounds and showed strong antioxidant activity in DPPH, ABTS, and FRAP assays. Furthermore, the extract exhibited antibacterial activity against Bacillus subtilis, Staphylococcus aureus, Salmonella enterica, and Streptococcus pyogenes at various concentrations. In contrast, Enterococcus faecalis, Escherichia coli, and Pseudomonas aeruginosa were not affected at the tested concentrations. No antifungal activity was detected against the filamentous fungus Aspergillus brasiliensis and the yeasts Saccharomyces cerevisiae, Candida parapsilosis, and Candida albicans. In vivo, EECM alleviated the clinical signs of colitis, reduced histological damage, and modulated hematological and biochemical parameters. Overall, EECM exhibited significant antioxidant and anti-inflammatory activities and may represent a promising natural candidate for IBD management. Further investigations into chronic experimental models are necessary to establish their therapeutic relevance. Full article