Yeast Form Research Articles

Intravaginal cooling provides symptom relief in women with vulvovaginal candidiasis and reduces immunopathology in an accompanying mouse model

Abstract Background Vulvovaginal candidiasis (VVC), caused primarily by Candida albicans, is currently treated with either prescription or over-the-counter antifungal drugs, often with variable efficacy and relapses. New and improved therapeutic strategies, including drug-free treatment alternatives, are needed. Upon overgrowth or environmental triggers, C. albicans yeast transitions into hyphae that results in an aberrant immunopathologic response by neutrophils, contributing to the characteristic vulvovaginal symptoms. The purpose of this study was to evaluate the efficacy of a patented intravaginal cooling device (Vlisse®) to provide symptom relief in women with VVC via putative reversal of C. albicans hyphae to the commensal yeast form, with additional proof of principle in an animal model. Methods This pilot clinical trial involved five women with VVC who used the device twice daily for three days. Vulvovaginal symptoms were monitored and scored for each use, followed by pelvic examination 30 days post-treatment. An established mouse model of VVC, using cooled magnetic micro stir rods for vaginal cooling, was employed to evaluate the effect on fungal morphology and vaginal immunopathology. Results Clinical cure, defined as complete reduction in symptoms without recurrence over a 30-day follow-up period, was achieved in all women. In the mouse model, the insertion of pre-cooled magnetic rods intravaginally for short periods, twice daily for 3 days, reduced the immunopathogenic neutrophil infiltration and hyphal presence. Conclusions Intravaginal cooling treatment provides clinical cure for VVC with strong proof of concept in an accompanying animal model. The therapeutic efficacy of Vlisse® warrants further testing in large-scale long-term clinical trials.

From High Protection to Lethal Effect: Diverse Outcomes of Immunization Against Invasive Candidiasis with Different Candida albicans Extracellular Vesicles

Extracellular vesicles (EVs) from Candida albicans can elicit immune responses, positioning them as promising acellular vaccine candidates. We characterized EVs from an avirulent C. albicans cell wall mutant (ecm33Δ) and evaluated their protective potential against invasive candidiasis. EVs from the yeast (YEVs) and hyphal (HEVs) forms of the SC5314 wild-type strain were also tested, yielding high survival rates with SC5314 YEV (91%) and ecm33 YEV immunization (64%). Surprisingly, HEV immunization showed a dual effect, resulting in 36% protection but also causing premature death in some mice. Proteomic analyses revealed distinct profiles among the top 100 proteins in the different EVs, which may explain these effects: a shared core of 50 immunogenic proteins such as Pgk1, Cdc19, and Fba1; unique, relevant immunogenic proteins in SC5314 YEVs; and proteins linked to pathogenesis, like Ece1 in SC5314 HEVs. Sera from SC5314 YEV-immunized mice showed the highest IgG2a titers and moderate IL-17, IFN-γ, and TNF-α levels, indicating the importance of both humoral and cellular responses for protection. These findings highlight the distinct immunogenic properties of C. albicans EVs, suggesting their potential in acellular vaccine development while emphasizing the need to carefully evaluate pathogenic risks associated with certain EVs.

АНАЛИЗ ДИНАМИКИ МИКРОБИОЛОГИЧЕСКИХ ПОКАЗАТЕЛЕЙ ЭМУЛЬСИОННЫХ ПИЩЕВЫХ СИСТЕМ В ПРОЦЕССЕ ХРАНЕНИЯ

The purpose of the study is to analyze the microbiological safety indicators of double emulsion food systems during storage, taking into account the influence of ultrasonic homogenization and storage processes. The study of sanitary-significant microbiological safety indicators (QMAFAnM, BGKP), pathogenic (Salomonella) and spoilage microorganisms (molds and yeasts) of double emulsion food systems water-oil-water and oil-water-oil obtained by ultrasonic homogenization, and control samples – direct and reverse emulsions obtained in the traditional way, were carried out using standard methods after 7, 14 and 21 days of storage. According to the results of the study, the absence of an increase in sanitary-significant microbiological indicators during the storage of emulsion food systems was established. During storage, the absence of bacteria of the Escherichia coli group, pathogenic microorganisms, including bacteria of the genus Salmonella, was revealed, the fungal microbiota was characterized by a lack of growth in all types of emulsion food systems, including control samples. The QMAFAnM indicator and the number of yeast forms of the double food emulsion system (water-oil-water) and the control sample – direct emulsion (oil in water) during storage were characterized by the absence of growth, while for these indicators of the double food emulsion system (oil-water-oil ) and the control sample - inverse emulsion (water in oil) showed a slight increase. The influence of the factors "shelf life" and "type of emulsion" on the microbial contamination of emulsion food systems has been established. The interaction of two factors had the most significant effect on the value of QMAFAnM indicators and the amount of yeast in emulsion food systems; "shelf life" was higher than the influence of the "type of emulsion" factor.

Engineering Adhesion of the Probiotic Strain Escherichia coli Nissle to the Fungal Pathogen Candida albicans.

Engineering live biotherapeutic products against fungal pathogens such as Candida albicans has been suggested as a means to tackle the increasing threat of fungal infections and the development of resistance to classical antifungal treatments. One important challenge in the design of live therapeutics is to control their localization inside the human body. The specific binding capability to target organisms or tissues would greatly increase their effectiveness by increasing the local concentration of effector molecules at the site of infection. In this study, we utilized surface display of carbohydrate binding domains to enable the probiotic E. coli Nissle 1917 to adhere specifically to the pathogenic yeast Candida albicans. Binding was quantified using a newly developed method based on the automated analysis of microscopic images. In addition to a rationally selected chitin binding domain, a synthetic peptide of identical length but distinct sequence also conferred binding. Efficient binding was specific to fungal hyphae, the invasive form of C. albicans, while the yeast form, as well as abiotic cellulose and PET particles, was only weakly recognized.

A Comprehensive Review of Plant Based Extracts for Preventing and Controlling Candida albicans

A common fungal pathogen Candida albicans can cause infections ranging from simple mucosal infections to serious systemic illnesses especially in people with weakened immune systems. Normally found in the human microbiome it turns harmful when the immune system is weakened. Its dimorphism—the capacity to transition between hyphal, and yeast forms—is a primary factor contributing to its pathogenicity, and is essential for both tissue penetration, and dissemination. This transition is crucial for tissue invasion, biofilm formation, and dissemination within the host. The infection mechanism involves adhesion to host cells, biofilm formation, epithelial invasion, and bloodstream dissemination. Furthermore, Candida albicans may use different carbon sources to adapt metabolically increasing its survival in a variety of host environments. Recent study revealed that Candida albicans possesses a parasexual cycle that allows for genetic diversity without requiring sexual reproduction. Plant-based remedies have become viable substitutes for conventional pharmaceutical antifungals with benefits including a decreased chance of drug resistance, fewer side effects, and cheaper expenses. Plant extracts offer several advantages, including a reduced likelihood of resistance development, fewer adverse side effects, and lower treatment costs. In particular, herbal medicines are emerging as safer, more sustainable options for managing C. albicans infections. As a result, plant based treatments are becoming increasingly recognized for their role in supporting antifungal therapy and enhancing overall treatment efficacy. In treating Candida albicans infections, herbal medicine is becoming more and more recognized as a useful tool due to its ability to offer safer, and more sustainable treatments. This pathogen can severely reduce crop yield and quality, posing a significant threat to global food security and agricultural economies, particularly in regions where these crops are staples. This review as an attempt to study their potential to address some of the limitations of current antifungal therapies, such as toxicity and resistance against C. albicans makes them an important area of research.

Multiple Abscesses and Plaques in an Immunocompetent Patient.

A 40-year-old immunocompetent man experiencing housing insecurity presented with a two-week history of fluctuant abscesses on the left forehead and supraorbital area that became crusted, scaly plaques, a pink plaque on the right dorsal hand, and a necrotic ulcer on the right great toe, resistant to two weeks of doxycycline. Shave biopsy of a new plaque on the right cheek revealed large, broad-based fungal yeast forms and concomitant right middle lobe consolidating pneumonia suggestive of a rare case of disseminated blastomycosis with fluctuant abscesses. Fungal cultures confirmed infection with blastomycosis, and patient was started on a six-month course of itraconazole.

Morphological transformation and pathogenicity of Metschnikowia bicuspidata in Chinese mitten crab (Eriocheir sinensis)

Metschnikowia bicuspidata, the causative agent of “milky disease” in Eriocheir sinensis, Chinese mitten crab, significantly threatens the crab aquaculture industry. Identifying morphological characteristics is crucial for disease prevention and control. Therefore, we characterized the yeast, pseudohyphal, and hyphal forms of M. bicuspidata, established stable culture methods, and elucidated the morphological transitions between the yeast and hyphal phases. Comparative analysis of the pathogenicity of these morphotypes revealed that the pseudohyphal form can be induced in a V8 juice medium supplemented with mannitol and dipotassium phosphate at 25 °C, whereas the hyphal form can be induced in yeast-leaching powder peptone dextrose agar (YPD) liquid medium supplemented with N-acetylglucosamine and serum at 37 °C and can revert to the yeast form during further incubation at 25 °C. In the pathogenicity assays, the yeast form exhibited the strongest adhesion, whereas the hyphal form demonstrated the highest virulence, with a higher pathogenicity towards healthy E. sinensis than the yeast and pseudohyphal forms. In crabs infected with the hyphal form, the progression of “milky disease” was accelerated, and the degree of hemolymph cloudiness was increased. Furthermore, the hyphal form showed greater sensitivity to antifungal agents, including amphotericin B, fluconazole, voriconazole, and 5-fluorocytosine, than the other forms. This study established cultivation methods for different morphotypes of M. bicuspidata, elucidated their pathogenicity, and provided insights into the life cycle of M. bicuspidata and potential avenues for precise disease management and control.

Chromium supplementation and type 2 diabetes mellitus: an extensive systematic review.

Diabetes is a global public health concern with increasing prevalence worldwide. Chromium (Cr), a trace element found in soil, water, and food, has been proposed to have a possible positive effect in glucose metabolism and diabetes mellitus prevention. However, the relationship between trivalent chromium [Cr(III)] exposure, mainly through the consumption of diet supplements, and type 2 diabetes mellitus (T2DM) remains controversial. An extensive systematic review of the current literature on randomized controlled studies (RCTs) was conducted from 1 January 2000, to January 2024 using the databases PubMed, Scopus, ScienceDirect, and Cochrane, with specific keywords and inclusion as well as exclusion criteria. After close screening of the research studies retrieved from the mentioned websites was conducted, the most related studies were included in the final systematic review. The studies were evaluated for the degree of relevance, quality, and risk bias, using appropriate quality assessment tools. Several of the included RCT studies reported possible benefits of Cr(III) supplementation, mainly in the form of chromium picolinate (CrPic), chromium yeast (CY), chromium chloride (CrCl3), and chromium nicotinate (CrN). The dosage of chromium was between 50 and 1000μg/day and it was consumed from 2 to 6months. Glycemic control markers, including FPG, insulin, HbA1C, and HOMA-IR levels, significantly decrease following chromium supplementation, mainly in studies with a longer intervention period. Supplementing with chromium (Cr) indicated that could significantly improve lipid profile by raising high-density lipoprotein and lowering triglyceride and total cholesterol while having little effect on low-density lipoprotein. However, most research findings include significant limitations, such as inconsistent dosage and type of chromium, formulation of supplements, and study duration. Further well-designed and high-quality research is needed to fully understand the role of chromium dietary supplementation and the potential risks related to its mechanisms of action, type, and dose, in the prevention and treatment of type 2 diabetes mellitus.

Histoplasmosis associated hemophagocytosis- a rare cause of pancytopenia in an immunocompetent patient

Pancytopenia as a result of hemophagocytosis in a middle-aged man presenting with high-grade fever of unknown etiology could be a rare consequence of Histoplasmosis infection. In the past, many cases of patients with human immunodeficiency virus infection contracting histoplasmosis-induced hemophagocytosis have been well documented, however, little data has been entered in the setting of HIV non-reactive status. Interestingly, we report a case of histoplasmosis in an immunocompetent male with the presence of yeast forms of H. capsulatum in the bone marrow smears. The patient was subsequently placed on Amphotericin B and corticosteroids but lost to the infectious disease. Cases like this, highlight the importance of taking into account the early decision for bone marrow sampling with careful attention to microscopic details as incidental pathologies may be elicited which could have significant effects on patient’s prognosis.

Auranofin is active against Histoplasma capsulatum and reduces the expression of virulence-related genes.

Auranofin is an approved anti-rheumatic drug that has a broad-range inhibitory action against several microorganisms, including human pathogenic fungi. The auranofin activity against Histoplasma capsulatum, the dimorphic fungus that causes histoplasmosis, has not been properly addressed. Since there are few therapeutic options for this life-threatening systemic mycosis, this study evaluated the effects of auranofin on H. capsulatum growth and expression of virulence factors. Minimal inhibitory and fungicidal concentrations (MIC and MFC, respectively) of auranofin against 15 H. capsulatum strains with distinct genetic backgrounds were determined using the yeast form of the fungus and a microdilution protocol. Auranofin activity was also assessed on a macrophage model of infection and on a Tenebrio molitor invertebrate animal model. Expression of virulence-related genes was compared between auranofin treated and untreated H. capsulatum yeast cells using a quantitative PCR assay. Auranofin affected the growth of different strains of H. capsulatum, with MIC and MFC values ranging from 1.25 to 5.0 μM and from 2.5 to >10 μM, respectively. Auranofin was able to kill intracellular H. capsulatum yeast cells and conferred protection against the fungus in the experimental animal model of infection. Moreover, the expression of catalase A, HSP70, superoxide dismutase, thioredoxin reductase, serine proteinase, cytochrome C peroxidase, histone 2B, formamidase, metallopeptidase, Y20 and YPS3 proteins were reduced after six hours of auranofin treatment. CONCLUSIONS/SIGNIFICANCE: Auranofin is fungicidal against H. capsulatum and reduces the expression of several virulence-related genes, which makes this anti-rheumatic drug a good candidate for new medicines against histoplasmosis.

In vivo anti-diabetic and anti-lipidemic evaluations of an excellent synthetic α-glucosidase inhibitor with dihydropyrano[3,2-c]quinoline skeleton.

The in vivo assay is a key step in the development of a new bioactive compound as a lead drug structure. Based on importance of α-glucosidase inhibitors in the control of blood glucose level (BGL) in diabetes, in the present work, 3-amino-1-(4-chlorophenyl)-12-oxo-11,12-dihydro-1H-benzo[h]pyrano[3,2-c]quinoline-2-carbonitrile (ACODDHBPQC) that showed excellent inhibitory activity on the yeast form of α-glucosidase was selected for in vivo anti-diabetic assay. The in vivo anti-diabetic and anti-lipidemic effects of this synthetic compound were evaluated using by a streptozotocin (STZ)-induced diabetic Wistar rat model. In silico docking study of ACODDHBPQC was performed by Atodock tools and absorption, distribution, metabolism, excretion, and toxicity (ADMET) properties of this compound was predicted by PreADMT online software. The obtained results revealed that selected compound ACODDHBPQC showed a significant anti-diabetic effect on diabetic rats. In vivo anti-lipidemic assay also demonstrated that ACODDHBPQC had favorable effects on cholesterol and LDL levels. Furthermore, in silico studies showed that ACODDHBPQC interacted with key residues of the α-glucosidase active site and had good pharmacokinetic and toxicity properties. In summary, anti-hyperglycemic effects of ACODDHBPQC was confirmed by in vivo study. However, more evaluations are needed to introduce ACODDHBPQC as a lead drug compound.

Antifungal Drug Resistance in Candida albicans: Identifying Novel Targets for the Development of Effective Antifungal Agents.

Candidiasis, a fungal infection initiated primarily through Candida albicans, affects various portions of the human body and is particularly prevalent in immunocompromised individuals. The pathogenicity of C. albicans is facilitated by numerous virulence causes, including adhesins, morphogenesis, and phenotypic switching. The organism’s capability in the direction of switching between yeast and hyphal forms contributes to the severity of infections. The appearance of resistant strains has rendered current treatments less effective, necessitating the exploration of new drug targets and the progress of novel antifungal agents. Antifungal drug resistance is a multifaceted phenomenon involving genetic mutations, overexpression of efflux pumps, epigenetic changes, and biofilm formation, all regulated by complex genetic and transcriptional networks. These resistance mechanisms can cause treatment failures, highlighting the need for new antifungal agents and improved diagnostic tools. The identification of potential drug targets in C. albicans is critical due to increasing resistance to existing antifungal agents. Recent studies have identified promising targets, for example the riboflavin metabolic pathway and unique protein kinases involved in regulating virulence and pathogenicity. Developing new antifungals is difficult due to C. albicans’ eukaryotic nature and resistance. Ongoing research is essential to find novel targets and strategies, especially with the limited antifungal drug classes available.

Ume6-dependent pathways of morphogenesis and biofilm formation in Candida auris.

Candida auris is a yeast pathogen causing nosocomial outbreaks of candidemia. Its ability to adhere to inert surfaces and to be transmitted from one patient to another via medical devices is of particular concern. Like other Candida spp., C. auris has the ability to transition from the yeast form to pseudohyphae and to build biofilms. Moreover, some isolates have a unique capacity to form aggregates. These morphogenetic changes may impact virulence. In this study, we demonstrated the role of the transcription factor Ume6 in C. auris morphogenesis. Genetic hyperactivation of Ume6 induced filamentation and aggregation. The Ume6-hyperactivated strain (UME6HA) also exhibited increased adhesion to inert surface and formed biofilms of higher biomass compared to the parental strain. Transcriptomic analyses of UME6HA revealed enrichment of genes encoding for adhesins, proteins involved in cell wall organization, sterol biosynthesis, and aspartic protease activities. The three most upregulated genes compared to wild-type were those encoding for the agglutin-like sequence adhesin Als4498, the C. auris-specific adhesin Scf1, and the hypha-specific G1 cyclin-related protein Hgc1. The deletion of these genes in the UME6HA background showed that Ume6 controls filamentation via Hgc1 and aggregation via Als4498 and Scf1. Adhesion to inert surface was essentially triggered by Scf1. However, Als4498 and Hgc1 were also crucial for biofilm formation. Our data show that Ume6 is a universal regulator of C. auris morphogenesis via distinct modulators.IMPORTANCEC. auris represents a public health threat because of its ability to cause difficult-to-treat infections and hospital outbreaks. The morphogenetic plasticity of C. auris, including its ability to filament, to form aggregates or biofilms on inert surfaces, is important to the fungus for interhuman transmission, skin or catheter colonization, tissue invasion, antifungal resistance, and escape of the host immune system. This work deciphered the importance of Ume6 in the control of distinct pathways involved in filamentation, aggregation, adhesion, and biofilm formation of C. auris. A better understanding of the mechanisms of C. auris morphogenesis may help identify novel antifungal targets.

Biochemical Characterization of Recombinant Enterococcus faecalis EntV Peptide to Elucidate Its Antihyphal and Antifungal Mechanisms against Candida albicans.

Candida albicans is a common opportunistic fungus in humans, whose morphological switch between yeast and hyphae forms represents a key virulence trait. Developing strategies to inhibit C. albicans hyphal growth may provide insights into designs of novel antivirulent therapeutics. Importantly, the gut commensal bacterium, Enterococcus faecalis, secretes a bacteriocin EntV which has potent antivirulent and antifungal effects against C. albicans in infection models; however, hampered by the challenges to access large quantities of bioactive EntV, the detailed understanding of its mechanisms on C. albicans has remained elusive. In this work, we biochemically reconstituted the proteolytic cleavage reaction to obtain recombinant EntV88-His6 on a large preparative scale, providing facile access to the C-terminal EntV construct. Under in vitro C. albicans hyphal assay with specific inducers, we demonstrated that EntV88-His6 exhibits potent bioactivity against GlcNAc-triggered hyphal growth. Moreover, with fluorescent FITC-EntV88-His6, we revealed that EntV88-His6 enters C. albicans via endocytosis and perturbs the proper localization of the polarisome scaffolding Spa2 protein. Our findings provide important clues on EntV's mechanism of action. Surprisingly, we showed that EntV88-His6 does not affect C. albicans yeast cell growth but potently exerts cytotoxicity against C. albicans under hyphal-inducing conditions in vitro. The combination of EntV88-His6 and GlcNAc displays rapid killing of C. albicans, rendering it a promising antivirulent and antifungal agent.

The yeast Dothiora sorbi IOJ-3 naturally produced various filamentous sectors with distinct abilities by undergoing DNA demethylation

Some fungi have demonstrated the ability to adapt rapidly to changing environments by exhibiting morphological plasticity, a trait influenced by species and environmental factors. Here, an anamorphic yeast strain IOJ-3 exhibited unique sectorization characteristics, naturally producing diverse filamentous sectors when cultivated on potato dextrose agar (PDA) medium or natural culture medium for durations exceeding 13 days. The strain IOJ-3 and its filamentous sectors were identified as Dothiora sorbi. The morphology of the sectors was consistent and heritable. The life cycle of strain IOJ-3 was investigated through microscopic observation, emphasizing the development of conidiogenous cells as a crucial stage, from which filamentous sectors originate. Some physiological characteristics of IOJ-3 and filamentous sectors are compared, and strain IOJ-3 has a higher antibiotic tolerance than two filamentous sectors, IOJ-3a expands faster on the culture medium, and IOJ-3b can penetrate cellophane. A transcriptomic analysis was conducted to investigate the differentially expressed genes between the yeast form IOJ-3 and its two filamentous sectors, revealing a total of 594 genes that exhibited consistent differential expression relative to IOJ-3, including 44 silencing genes in IOJ-3 that were activated. Gene Ontology analysis indicated that these differentially expressed genes were primarily associated with the cellular component category. Furthermore, adding 5-Azacytidine accelerated filamentous sectorization and increased the proportion of filamentous cells of strain IOJ-3 in PD liquid media, suggesting that the filamentous sectorization observed in strain IOJ-3 is linked to processes of DNA demethylation. In conclusion, this study sheds light on the biological characteristics of D. sorbi regarding morphological transitions and provides substantial direction for exploring genes related to fungal filamentous development.

Sinefungin, a natural nucleoside analog of S-adenosyl methionine, impairs the pathogenicity of Candida albicans

Candida albicans, an opportunistic fungal pathogen, causes life-threatening infections in immunocompromised patients. Current antifungals are limited by toxicity, drug-drug interactions, and emerging resistance, underscoring the importance of identifying novel treatment approaches. Here, we elucidate the impact of sinefungin, an analog of S-adenosyl methionine, on the virulence of C. albicans strain SC5314 and clinical isolates. Our data indicate that sinefungin impairs pathogenic traits of C. albicans including hyphal morphogenesis, biofilm formation, adhesion to epithelial cells, and virulence towards Galleria mellonella, highlighting sinefungin as an avenue for therapeutic intervention. We determine that sinefungin particularly disturbs N6-methyladenosine (m6A) formation. Transcriptome analysis of C. albicans hyphae upon sinefungin treatment reveals an increase in transcripts related to the yeast form and decrease in those associated with hyphae formation and virulence. Collectively, our data propose sinefungin as a potent molecule against C. albicans and emphasize further exploration of post-transcriptional control mechanisms of pathogenicity for antifungal design.

An overview of various stages and morphology of Histoplasma capsulatum var. farciminosum in the horse.

This article describes the development of the pathogenic dimorphic fungus Histoplasma capsulatum var. farciminosum (HCF), which is the causative agent of Equine epizootic lymphangitis (EEL), from the mycelial form in the soil to the yeast form in the horse. In this study, the stages and morphology of HCF were identified through histopathological analysis and culture with various samples collected in Ethiopia from 15 horses showing clinical signs of EEL. In equids, especially cart horses in Ethiopia, poor-quality harnesses cause cutaneous wounds, which often attract flies facilitating the transmission of the fungus. Also, HCF infection occurs through open wounds or ocular mucous membranes when horses roll on contaminated damp soil. Respiratory histoplasmosis can occur through inhaling fungal spores, which is rare. HCF microconidia enter the lungs and skin wounds and are phagocytized by tissue-resident macrophages. The spores undergo intracellular replication within the macrophages transitioning into yeasts. The infected macrophages undergo lysis releasing pathogenic yeast cells into the surrounding tissue. Consequently, yeast-rich purulent exudate is produced, contaminating the soil in stables where yeast cells germinate into the mycelial form, and the entire process starts from the beginning.

Yeast and filamentous Candida auris stimulate distinct immune responses in the skin.

Candida auris, an emerging multidrug-resistant fungal pathogen, predominately colonizes the human skin long term leading to subsequent life-threatening invasive infections. Fungal morphology is believed to play a critical role in modulating mucocutaneous antifungal immunity. In this study, we used an intradermal mouse model of C. auris infection to examine fungal colonization and the associated innate and adaptive immune response to yeast and filamentous C. auris strains. Our results indicate that mice infected with a filamentous C. auris had significantly decreased fungal load compared to mice infected with the yeast form. Mice infected with yeast and filamentous forms of C. auris stimulated distinct innate immune responses. Phagocytic cells (CD11b+Ly6G+ neutrophils, CD11b+Ly6Chi inflammatory monocytes, and CD11b+MHCII+CD64+ macrophages) were differentially recruited to mouse skin tissue infected with yeast and filamentous C. auris. The percentage and absolute number of interleukin 17 (IL-17) producing innate lymphoid cells, TCRγδ+, and CD4+ T cells in the skin tissue of mice infected with filamentous C. auris were significantly increased compared to the wild-type of yeast strain. Furthermore, complementation of filamentous mutant strain of C. auris (Δelm1 + ELM1) strain exhibited wild-type yeast morphology in vivo and induced comparable level of skin immune responses similar to mice infected with yeast strain. Collectively, our findings indicate that yeast and filamentous C. auris induce distinct local immune responses in the skin. The decreased fungal load observed in mouse skin infected with filamentous C. auris is associated with a potent IL-17 immune response induced by this morphotype.IMPORTANCECandida auris is a globally emerging fungal pathogen that transmits among individuals in hospitals and nursing home residents. Unlike other Candida species, C. auris predominantly colonizes and persists in skin tissue resulting in outbreaks of systemic infections. Understanding the factors that regulate C. auris skin colonization and host immune response is critical to develop novel preventive and therapeutic approaches against this emerging pathogen. We identified that yeast and filamentous forms of C. auris induce distinct skin immune responses in the skin. These findings may help explain the differential colonization and persistence of C. auris morphotypes in skin tissue. Understanding the skin immune responses induced by yeast and filamentous C. auris is important to develop novel vaccine strategies to combat this emerging fungal pathogen.

A Proteogenomic Pipeline for the Analysis of Protein Biosynthesis Errors in the Human Pathogen Candida albicans

Candida albicans is a diploid pathogen known for its ability to live as a commensal fungus in healthy individuals but causing both superficial infections and disseminated candidiasis in immunocompromised patients where it is associated with high morbidity and mortality. Its success in colonizing the human host is attributed to a wide range of virulence traits that modulate interactions between the host and the pathogen, such as optimal growth rate at 37°C, the ability to switch between yeast and hyphal forms, and a remarkable genomic and phenotypic plasticity. A fascinating aspect of its biology is a prominent heterogeneous proteome that arises from frequent genomic rearrangements, high allelic variation, and high levels of amino acid misincorporations in proteins. This leads to increased morphological and physiological phenotypic diversity of high adaptive potential, but the scope of such protein mistranslation is poorly understood due to technical difficulties in detecting and quantifying amino acid misincorporation events in complex protein samples. We have developed and optimized mass spectrometry and bioinformatics pipelines capable of identifying rare amino acid misincorporation events at the proteome level. We have also analyzed the proteomic profile of an engineered C.albicans strain that exhibits high level of leucine misincorporation at protein CUG sites and employed an invivo quantitative gain-of-function fluorescence reporter system to validate our LC-MS/MS data. C.albicans misincorporates amino acids above the background level at protein sites of diverse codons, particularly at CUG, confirming our previous data on the quantification of leucine incorporation at single CUG sites of recombinant reporter proteins, but increasing misincorporation of Leucine at these sites does not alter the translational fidelity of the other codons. These findings indicate that the C.albicans statistical proteome exceeds prior estimates, suggesting that its highly plastic phenome may also be modulated by environmental factors due to translational ambiguity.

Cold atmospheric plasma therapy for Malassezia folliculitis: Laboratory investigations and a randomized clinical trial.

Current treatment options for Malassezia folliculitis (MF) are limited. Recent research has demonstrated the inhibitory effect of cold atmospheric plasma (CAP) on the growth of Malassezia pachydermatis in vitro, suggesting CAP as a potential therapeutic approach for managing MF. The objective of our study is to assess the in vitro antifungal susceptibility of Malassezia yeasts to CAP. Additionally, we aim to evaluate the efficacy and tolerability of CAP in treating patients with MF. We initially studied the antifungal effect of CAP on planktonic and biofilm forms of Malassezia yeasts, using well-established techniques such as zone of inhibition, transmission electron microscopy, colony count assay and 2,3-bis(2-methoxy-4-nitro-5-sulfophenyl)-2H-tetrazolium-5-carboxanilide salt assay. Subsequently, a randomized (1:1 ratio), active comparator-controlled, observer-blind study was conducted comparing daily CAP therapy versus itraconazole 200mg/day for 2weeks in 50 patients with MF. Efficacy outcomes were measured by success rate, negative microscopy rate and changes in Dermatology Life Quality Index (DLQI) and Global Aesthetic Improvement Scale (GAIS) scores. Safety was assessed by monitoring adverse events (AEs) and local tolerability. In laboratory investigations, CAP time-dependently inhibited the growth of Malassezia yeasts in both planktonic and biofilm forms. Forty-nine patients completed the clinical study. At week 2, success was achieved by 40.0% of subjects in the CAP group versus 58.3% in the itraconazole group (p=0.199). The negative direct microscopy rates of follicular samples were 56.0% in the CAP group versus 66.7% in the itraconazole group (p=0.444). No significant differences were found in the proportion of subjects achieving DLQI scores of 0/1 (p=0.456) or in the GAIS responder rates (p=0.588) between the two groups. Three patients in the CAP group and one patient in the itraconazole group reported mild AEs. CAP demonstrated significant antifungal activity against Malassezia yeasts in vitro and exhibited comparable efficacy to itraconazole in treating MF patients. Without the associated adverse effects of oral antifungal drugs, CAP can be considered a promising and safe treatment modality for MF.