Amphotericin B and micafungin duo-loaded nanoemulsion as a potential strategy against Candida auris biofilms.

Candida auris is a multidrug-resistant yeast that has seen a worrying increase during the COVID-19 pandemic. Give7/n this, new therapeutic options, such as controlled-release nanomaterials, may be promising in combating the infection. Therefore, this study aimed to develop amphotericin B (AmB) and micafungin (MICA)-loaded nanoemulsions (NEMA) and evaluated against biofilms of C. auris. Nanoemulsions (NEs) were characterized and determined minimum inhibitory concentration MIC90, checkerboard and anti-biofilm. NEMA presented a size of 53.7 and 81.4 nm for DLS and NTA, respectively, with good stability and spherical morphology. MICAmB incorporated efficiency was 88.4 and 99.3%, respectively. The release results show that AmB and MICA obtained a release of 100 and 63.4%, respectively. MICAmB and NEMA showed MIC90 values of 0.015 and 0.031 ug/mL, respectively and synergism. NEMA showed greater metabolic inhibition and morphological changes in mature biofilms. This drugs combination and co-encapsulation proved to be a promising therapy against C. auris biofilms.

Resistance and virulence genes characteristic of a South Asia Clade (I) Candida auris strain isolated from blood in Beijing.

INTRODUCTION: Candida auris is a globally disseminated invasive ascomycetous yeast, that imposes a substantial burden on healthcare systems. It has been documented to have spread to over 40 countries across six continents, necessitating in-depth comprehension through advanced techniques like Whole-Genome Sequencing. METHOD: This study entailed the isolation and Whole-Genome Sequencing of a fluconazole-resistant C. auris strain (CA01) obtained from a patient's blood in Beijing. Genome analysis was conducted to classify the strain, and molecular docking was performed to understand the impact of mutations on drug resistance. RESULTS: Genome analysis revealed that CA01 belongs to the South Asia Clade (I) and shares the closest genetic relationship with previously reported strains BJCA001 and BJCA002. Notably, unlike BJCA001, CA01 exhibits significant resistance to fluconazole primarily due to the A395T mutation in the ERG11 gene. Molecular docking studies demonstrated that this mutation leads to geometric changes in the active site where fluconazole binds, resulting in decreased binding affinity. Additionally, the present findings have identified several core virulence genes in C. auris, such as RBF1. DISCUSSION: The findings from this study expand the understanding of the genetic diversity and adaptive mechanisms of C. auris within the South Asia Clade (I). The observed fluconazole resistance driven by the ERG11 mutation A395T highlights the need for heightened awareness and adaptation in clinical treatment strategies in China. This study provides critical insights into drug resistance and virulence profiles at a genetic level, which could guide future therapeutic and management strategies for C. auris infections.

Small molecule inhibitors of fungal Δ(9) fatty acid desaturase as antifungal agents against Candida auris.

Candida auris has emerged as a significant healthcare-associated pathogen due to its multidrug-resistant nature. Ongoing constraints in the discovery and provision of new antifungals create an urgent imperative to design effective remedies to this pressing global blight. Herein, we screened a chemical library and identified aryl-carbohydrazide analogs with potent activity against both C. auris and the most prevalent human fungal pathogen, C. albicans. SPB00525 [N'-(2,6-dichlorophenyl)-5-nitro-furan-2-carbohydrazide] exhibited potent activity against different strains that were resistant to standard antifungals. Using drug-induced haploinsufficient profiling, transcriptomics and metabolomic analysis, we uncovered that Ole1, a Δ(9) fatty acid desaturase, is the likely target of SPB00525. An analog of the latter, HTS06170 [N'-(2,6-dichlorophenyl)-4-methyl-1,2,3-thiadiazole-5-carbohydrazide], had a superior antifungal activity against both C. auris and C. albicans. Both SPB00525 and HTS06170 act as antivirulence agents and inhibited the invasive hyphal growth and biofilm formation of C. albicans. SPB00525 and HTS06170 attenuated fungal damage to human enterocytes and ameliorate the survival of Galleria mellonella larvae used as systemic candidiasis model. These data suggest that inhibiting fungal Δ(9) fatty acid desaturase activity represents a potential therapeutic approach for treating fungal infection caused by the superbug C. auris and the most prevalent human fungal pathogen, C. albicans.

Genetic microevolution of clinical Candida auris with reduced Amphotericin B sensitivity in China.

The global rate of Amphotericin B (AmB) resistance in Candida auris has surpassed 12%. However, there is limited data on available clinical treatments and microevolutionary analyses concerning reduced AmB sensitivity. In this study, we collected 18 C. auris isolates from five patients between 2019 and 2022. We employed clinical data mining, genomic, and transcriptomic analyses to identify genetic evolutionary features linked to reduced AmB sensitivity in these isolates during clinical treatment. We identified six isolates with a minimum inhibitory concentration (MIC) of AmB below 0.5 µg/mL (AmB0.5) and 12 isolates with an AmB-MIC of 1 µg/mL (AmB1) or ≥ 2 µg/mL (AmB2). All five patients received 24-hour AmB (5 mg/L) bladder irrigation treatment. Evolutionary analyses revealed an ERG3 (c923t) mutation in AmB1 C. auris. Additionally, AmB2 C. auris was found to contain a t2831c mutation in the RAD2 gene. In the AmB1 group, membrane lipid-related gene expression (ERG1, ERG2, ERG13, and ERG24) was upregulated, while in the AmB2 group, expression of DNA-related genes (e.g. DNA2 and PRI1) was up-regulated. In a series of C.auris strains with reduced susceptibility to AmB, five key genes were identified: two upregulated (IFF9 and PGA6) and three downregulated (HGT7, HGT13,and PRI32). In this study, we demonstrate the microevolution of reduced AmB sensitivity in vivo and further elucidate the relationship between reduced AmB sensitivity and low-concentration AmB bladder irrigation. These findings offer new insights into potential antifungal drug targets and clinical markers for the "super fungus", C. auris.

Genotypic and phenotypic characterisation of a nosocomial outbreak of Candida auris in Spain during 5 years.

OBJECTIVES: The investigation of Candida auris outbreaks is needed to provide insights into its population structure and transmission dynamics. We genotypically and phenotypically characterised a C. auris nosocomial outbreak occurred in Consorcio Hospital General Universitario de Valencia (CHGUV), Spain. METHODS: Data and isolates were collected from CHGUV from September 2017 (first case) until September 2021. Thirty-five isolates, including one from an environmental source, were randomly selected for whole genome sequencing (WGS), and the genomes were analysed along with a database with 335 publicly available genomes, assigning them to one of the five major clades. In order to identify polymorphisms associated with drug resistance, we used the fully susceptible GCA_003014415.1 strain as reference sequence. Known mutations in genes ERG11 and FKS1 conferring resistance to fluconazole and echinocandins, respectively, were investigated. Isolates were classified into aggregating or non-aggregating. RESULTS: All isolates belonged to clade III and were from an outbreak with a single origin. They clustered close to three publicly available genomes from a hospital from where the first patient was transferred, being the probable origin. The mutation VF125AL in the ERG11 gene, conferring resistance to fluconazole, was present in all the isolates and one isolate also carried the mutation S639Y in the FKS1 gene. All the isolates had a non-aggregating phenotype (potentially more virulent). CONCLUSIONS: Isolates are genotypically related and phenotypically identical but one with resistance to echinocandins, which seems to indicate that they all belong to an outbreak originated from a single isolate, remaining largely invariable over the years. This result stresses the importance of implementing infection control practices as soon as the first case is detected or when a patient is transferred from a setting with known cases.

Candida auris: Understanding the dynamics of C. auris infection versus colonization.

Candida auris is a pathogen of growing public health concern worldwide. However, risk factors contributing to C. auris infection in patients colonized with C. auris remain unclear. Understanding these risk factors is crucial to prevent colonization-to-infection transition and devise effective preventive strategies. This study aimed to investigate risk factors associated with C. auris infection compared to colonization. The study included 97 patients who acquired laboratory-confirmed C. auris in either matrix-assisted laser desorption/ionization-time of flight (MALDI-TOF) mass spectrometry or VITEK 2 system from October 2019 to June 2023. Baseline demographics and known risk factors associated with C. auris infection were collected from electronic medical records. The infection group had C. auris from a sterile site or non-sterile site with evidence of infection. The colonization group was followed up for a median of 30 days for any signs of infection. Associations between relevant variables and C. auris infection were assessed using multivariable logistic regression. The infection group (n = 31) was more likely to be bedbound, with longer hospital stays and more arterial catheters. Chronic kidney disease (odds ratio [OR] 45.070), carriage of multidrug-resistant organisms (OR 64.612), and vasopressor use for > 20 days (OR 68.994) were associated with C. auris infection, after adjusting for sex, age, and prior colonization with C. auris. Chronic kidney disease, carriage of multidrug-resistant organisms, and prolonged vasopressor use emerged as significant risk factors for C. auris infection compared to colonization. They could be used to predict C. auris infection early in patients colonized with C. auris.

Identifying risk factors for Candida auris infection should be an essential component of care in patients colonized with C. auris. Chronic kidney disease, carriage of multidrug-resistant organisms, and prolonged vasopressor use emerged as significant risk factors for C. auris infection.

Candida auris: A focused review for emergency clinicians.

INTRODUCTION: Candida auris is an emerging pathogen and human health threat. However, diagnosis and treatment of fungal infection due to C. auris are challenging. OBJECTIVE: This narrative review provides a focused overview of C. auris for the emergency clinician. DISCUSSION: C. auris was first identified in 2009 and is currently present on all continents except Antarctica. C. auris possesses multiple genetic factors resulting in antimicrobial resistance, increased virulence and survival within the host, and environmental adaptation. It is readily transmitted from person to person and from the environment to a person, resulting in colonization. Infection may develop days to months following colonization, most commonly in those with immunocompromised state, significant comorbidities or other underlying conditions, healthcare exposure, and recent antimicrobial therapy. Candidemia, device infection (e.g., central venous catheter), soft tissue or wound infection, burn infection, osteomyelitis, myocarditis, meningitis, and urinary tract infection have been associated with C. auris. Samples should be obtained from the suspected site of infection for microbiological culture. Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) with reference databases to differentiate C. auris from other species is optimal for diagnosis, though other molecular testing methods are available. Treatment is challenging due to antifungal resistance, with over 90% resistant to fluconazole. Echinocandins are most commonly used as the first line therapy. Prevention of colonization and infection are vital and include screening in high-risk populations and strict adherence to infection prevention practices with contact precautions and hand hygiene, as well as appropriate decontamination of patient areas. CONCLUSION: An understanding of C. auris can assist emergency clinicians in the care of infected or colonized patients.

Transcriptome Analysis of Human Dermal Cells Infected with Candida auris Identified Unique Pathogenesis/Defensive Mechanisms Particularly Ferroptosis.

Candida auris is an emerging multi-drug resistant yeast that can cause life-threatening infections. A recent report clarified the ability of C. auris to form a biofilm with enhanced drug resistance properties in the host skin's deep layers. The formed biofilm may initiate further bloodstream spread and immune escape. Therefore, we propose that secreted chemicals from the biofilm may facilitate fungal pathogenesis. In response to this interaction, the host skin may develop potential defensive mechanisms. Comparative transcriptomics was performed on the host dermal cells in response to indirect interaction with C. auris biofilm through Transwell inserts compared to planktonic cells. Furthermore, the effect of antifungals including caspofungin and fluconazole was studied. The obtained data showed that the dermal cells exhibited different transcriptional responses. Kyoto Encyclopedia of Genes and Genomes and Reactome analyses identified potential defensive responses employed by the dermal cells and potential toxicity induced by C. auris. Additionally, our data indicated that the dominating toxic effect was mediated by ferroptosis; which was validated by qRT-PCR, cytotoxicity assay, and flow cytometry. On the other hand, the viability of C. auris biofilm was enhanced and accompanied by upregulation of MDR1, and KRE6 upon interaction with dermal cells; both genes play significant roles in drug resistance and biofilm maturation, respectively. This study for the first-time shed light on the dominating defensive responses of human dermal cells, microbe colonization site, to C. auris biofilm and its toxic effects. Further, it demonstrates how C. auris biofilm responds to the defensive mechanisms developed by the human dermal cells.

Decoding host cell interaction- and fluconazole-induced metabolic alterations and drug resistance in Candida auris.

Candida auris is an emerging drug-resistant pathogen associated with high mortality rates. This study aimed to explore the metabolic alterations and associated pathogenesis and drug resistance in fluconazole-treated Candida auris-host cell interaction. Compared with controls, secreted metabolites from fluconazole-treated C. auris and fluconazole-treated C. auris-host cell co-culture demonstrated notable anti-Candida activity. Fluconazole caused significant reductions in C. auris cell numbers and aggregated phenotype. Metabolites produced by C. auris with potential fungal colonization, invasion, and host immune evasion effects were identified. Metabolites known to enhance biofilm formation produced during C. auris-host cell interaction were inhibited by fluconazole. Fluconazole enhanced the production of metabolites with biofilm inhibition activity, including behenyl alcohol and decanoic acid. Metabolites with potential Candida growth inhibition activity such as 2-palmitoyl glycerol, 1-tetradecanol, and 1-nonadecene were activated by fluconazole. Different patterns of proinflammatory cytokine expression presented due to fluconazole concentration and host cell type (fibroblasts versus macrophages). This highlights the immune response's complexity, emphasizing the necessity for additional research to comprehend cell-type-specific responses to antifungal therapies. Both host cell interaction and fluconazole treatment increased the expression of CDR1 and ERG11 genes, both associated with drug resistance. This study provides insights into pathogenesis in C. auris due to host cell interaction and fluconazole treatment. Understanding these interactions is crucial for enhancing fluconazole sensitivity and effectively combating C. auris.

Antifungal susceptibility pattern of Candida auris strains: Analysis of clinical strains in a tertiary-care educational university hospital.

Herein, we aimed to investigate the antifungal susceptibility pattern of Candida auris clinical strains in our setting Bahrain Oncology Center-King Hamad University Hospital-Bahrain. C. auris strains isolated from different clinical specimens in the Microbiology Laboratory from October-2021 to November-2022 were evaluated. Species-level identification of fungi was performed by MALDI-TOF (Bruker, Germany). Minimum inhibitory concentration (MIC) was determined either by E-test strips or by MICRONAUT MIC system based on CDC guidelines for C. auris antifungal interpretation. Fluconazole, amphotericin-B, voriconazole, and caspofungin susceptibility data of the clinical strains were analyzed. A total of 40 clinical isolates were included: 25% were blood culture isolates, 65% were urinary, and 10% were soft tissue isolates. Only 29 strains could be tested for amphotericin-B and 32 for voriconazole. Overall resistance pattern was as follows: 100% resistance to fluconazole, 2.5% resistance to caspofungin, and 0% resistance to amphotericin b. Median voriconazole MIC was 0.015 ug/ml (min 0.08, max= 0.064 ug/ml). We had no fluconazole-sensitive strain and only one caspofungin-resistant strain. A single isolate (2.5%), which was associated with candidemia, demonstrated resistance to two antifungal agents: fluconazole and caspofungin. No triple or quadruple drug resistant strain existed.

Evolutionary accumulation of FKS1 mutations from clinical echinocandin-resistant Candida auris.

INTRODUCTION: Drug resistance to echinocandins, first-line drugs used to treat Candida auris infection, is rapidly emerging. However, the accumulation of mutations in genes other than FKS1 (before an isolate develops to resistance via FKS1 mutations), remains poorly understood. Methods: Four clinical cases and 29 isolates associated with the incremental process of echinocandin resistance were collected and analyzed using antifungal drug susceptibility testing and genome sequencing to assess the evolution of echinocandin resistance. FINDINGS: Six echinocandin minimum inhibitory concentration (MIC)-elevated C. auris strains and seven resistant strains were isolated from the urinary system of patients receiving echinocandin treatment. Meanwhile, phylogenetic analyses illustrated that the echinocandin-resistant strains were closely related to other strains in the same patient. Genomic data revealed that the echinocandin-resistant strains had FKS1 mutations. Furthermore, three categories (ECN-S/E/R) of non-synonymous mutant SNP genes (such as RBR3, IFF6, MKC1, MPH1, RAD2, and MYO1) in C. auris appeared to be associated with the three-stage-evolutionary model of echinocandin resistance in C. glabrata: cell wall stress, drug adaptation, and genetic escape (FKS mutation). INTERPRETATION: Echinocandin-resistant C. auris undergoes spatial and temporal phase changes closely related to echinocandin exposure, particularly in the urinary system. These findings suggest that FKS1 mutations mediate an evolutionary accumulation of echinocandin resistance followed by modulation of chromosome remodelling and DNA repair processes that ultimately lead to FKS1 hot spot mutations and the development of drug resistance. This study provides an in-depth exploration of the molecular pathways involved in the evolution of Candida auris echinocandin resistance.

Chitinase-functionalized UiO-66 framework nanoparticles active against multidrug-resistant Candida Auris.

Candida auris (C. auris) is a yeast that has caused several outbreaks in the last decade. Cell wall chitin plays a primary role in the antifungal resistance of C. auris. Herein, we investigated the potential of chitinase immobilized with UiO-66 to act as a potent antifungal agent against C. auris. Chitinase was produced from Talaromyces varians SSW3 in a yield of 8.97 U/g dry substrate (ds). The yield was statistically enhanced to 120.41 U/g ds by using Plackett-Burman and Box-Behnken design. We synthesized a UiO-66 framework that was characterized by SEM, TEM, XRD, FTIR, a particle size analyzer, and a zeta sizer. The produced framework had a size of 70.42 ± 8.43 nm with a uniform cubic shape and smooth surface. The produced chitinase was immobilized on UiO-66 with an immobilization yield of 65% achieved after a 6 h loading period. The immobilization of UiO-66 increased the enzyme activity and stability, as indicated by the obtained Kd and T1/2 values. Furthermore, the hydrolytic activity of chitinase was enhanced after immobilization on UiO-66, with an increase in the Vmax and a decrease in the Km of 2- and 38-fold, respectively. Interestingly, the antifungal activity of the produced chitinase was boosted against C. auris by loading the enzyme on UiO-66, with an MIC50 of 0.89 ± 0.056 U/mL, compared to 5.582 ± 0.57 U/mL for the free enzyme. This study offers a novel promising alternative approach to combat the new emerging pathogen C. auris.

Suppressing the virulence factors of Candida auris with baicalein through multifaceted mechanisms.

Candida auris, a rapidly spreading multi-drug-resistant fungus, is causing lethal infections under certain conditions globally. Baicalin (BE), an active ingredient extracted from the dried root of Scutellaria baicalensis Georgi, exhibits antifungal activity. However, studies have shown the distinctive advantages of Traditional Chinese medicine in combating fungal infections, while the effect of BE, an active ingredient extracted from the dried roots of Scutellaria baicalensis Georgi, on C. auris, remains unknown. Therefore, this study aims to evaluate the potential of BE as an antifungal agent against the emerging multidrug-resistant C. auris. Various assays and models, including microbroth dilution, time growth curve analysis, spot assays, adhesion tests, flocculation test, cell surface hydrophobicity assay, hydrolase activity assays, XTT assay, violet crystal assay, scanning electron microscope (SEM), confocal laser scanning microscope (CLSM), flow cytometry, Live/dead fluorescent staining, reactive oxygen species (ROS), cell wall assay, aggregation assay, porcine skin model, Galleria mellonella larvae (G. mellonella larvae) infection model, and reverse transcription-quantitative polymerase chain reaction (RT-PCR) were utilized to investigate how baicalein suppresses C. auris through possible multifaceted mechanisms. The findings indicate that BE strongly inhibited C. auris growth, adhesion, and biofilm formation. It also effectively reduced drug resistance and aggregation by disrupting the cell membrane and cell wall while reducing colonization and invasion of the host. Transcriptome analysis showed significant modulation in gene expression related to different virulence factors post-BE treatment. In conclusion, BE exhibits significant effectiveness against C. auris, suggesting its potential as a viable treatment option due to its multifaceted suppression mechanisms.

Increase in candidemia cases and emergence of fluconazole-resistant Candida parapsilosis and C. auris isolates in a tertiary care academic hospital during the COVID-19 pandemic, Greece, 2020 to 2023.

BackgroundThe COVID-19 pandemic and the emergence of Candida auris have changed the epidemiological landscape of candidaemia worldwide.AimWe compared the epidemiological trends of candidaemia in a Greek tertiary academic hospital before (2009-2018) and during the early COVID-19 (2020-2021) and late COVID-19/early post-pandemic (2022-2023) era.MethodsIncidence rates, species distribution, antifungal susceptibility profile and antifungal consumption were recorded, and one-way ANOVA or Fisher's exact test performed. Species were identified by MALDI-ToF MS, and in vitro susceptibility determined with CLSI M27-Ed4 for C. auris and the EUCAST-E.DEF 7.3.2 for other Candida spp.ResultsIn total, 370 candidaemia episodes were recorded during the COVID-19 pandemic. Infection incidence (2.0 episodes/10,000 hospital bed days before, 3.9 during the early and 5.1 during the late COVID-19 era, p < 0.0001), C. auris (0%, 9% and 33%, p < 0.0001) and fluconazole-resistant C. parapsilosis species complex (SC) (20%, 24% and 33%, p = 0.06) infections increased over time, with the latter not associated with increase in fluconazole/voriconazole consumption. A significant increase over time was observed in fluconazole-resistant isolates regardless of species (8%, 17% and 41%, p < 0.0001). Resistance to amphotericin B or echinocandins was not recorded, with the exception of a single pan-echinocandin-resistant C. auris strain.ConclusionCandidaemia incidence nearly tripled during the COVID-19 era, with C. auris among the major causative agents and increasing fluconazole resistance in C. parapsilosis SC. Almost half of Candida isolates were fluconazole-resistant, underscoring the need for increased awareness and strict implementation of infection control measures.

Detection and characterisation of a sixth Candida auris clade in Singapore: a genomic and phenotypic study.

BACKGROUND: The emerging fungal pathogen Candida auris poses a serious threat to global public health due to its worldwide distribution, multidrug resistance, high transmissibility, propensity to cause outbreaks, and high mortality. We aimed to characterise three unusual C auris isolates detected in Singapore, and to determine whether they constitute a novel clade distinct from all previously known C auris clades (I-V). METHODS: In this genotypic and phenotypic study, we characterised three C auris clinical isolates, which were cultured from epidemiologically unlinked inpatients at a large tertiary hospital in Singapore. The index isolate was detected in April, 2023. We performed whole-genome sequencing (WGS) and obtained hybrid assemblies of these C auris isolates. The complete genomes were compared with representative genomes of all known C auris clades. To provide a global context, 3651 international WGS data from the National Center for Biotechnology Information (NCBI) database were included in a high-resolution single nucleotide polymorphism (SNP) analysis. Antifungal susceptibility testing was done and antifungal resistance genes, mating-type locus, and chromosomal rearrangements were characterised from the WGS data of the three investigated isolates. We further implemented Bayesian logistic regression models to classify isolates into known clades and simulate the automatic detection of isolates belonging to novel clades as their WGS data became available. FINDINGS: The three investigated isolates were separated by at least 37 000 SNPs (range 37 000-236 900) from all existing C auris clades. These isolates had opposite mating-type allele and different chromosomal rearrangements when compared with their closest clade IV relatives. The isolates were susceptible to all tested antifungals. Therefore, we propose that these isolates represent a new clade of C auris, clade VI. Furthermore, an independent WGS dataset from Bangladesh, accessed via the NCBI Sequence Read Archive, was found to belong to this new clade. As a proof-of-concept, our Bayesian logistic regression model was able to flag these outlier genomes as a potential new clade. INTERPRETATION: The discovery of a new C auris clade in Singapore and Bangladesh in the Indomalayan zone, showing a close relationship to clade IV members most commonly found in South America, highlights the unknown genetic diversity and origin of C auris, particularly in under-resourced regions. Active surveillance in clinical settings, along with effective sequencing strategies and downstream analysis, will be essential in the identification of novel strains, tracking of transmission, and containment of adverse clinical effects of C auris infections. FUNDING: Duke-NUS Academic Medical Center Nurturing Clinician Researcher Scheme, and the Genedant-GIS Innovation Program.

Clinical and microbiological characteristics of a hospital outbreak of Candida auris in a referral hospital in Lima, Peru.

BACKGROUND: Candida auris, a multidrug-resistant fungal pathogen, has received considerable attention owing to its recent surge, especially in South America, which coincides with the ongoing global COVID-19 pandemic. Understanding the clinical and microbiological characteristics of outbreaks is crucial for their effective management and control. OBJECTIVE: This retrospective observational study aimed to characterize a C. auris outbreak at a Peruvian referral hospital between January 2021 and July 2023. METHODS: Data were collected from hospitalized patients with positive C. auris culture results. Microbiological data and antifungal susceptibility test results were analysed. Additionally, infection prevention and control measures have been described. Statistical analysis was used to compare the characteristics between the infected and colonized patients. RESULTS: Thirty-three patients were identified, mostly male (66.7%), with a median age of 53 years. Among them, 18 (54.5%) were colonized, and 15 (45.5%) were infected. Fungemia was the predominant presentation (80%), with notable cases of fungemia in tuberculosis patients with long-stay devices for parenteral anti-tuberculosis therapy. Seventy-five percent of the isolates exhibited fluconazole resistance. Echinocandins were the primary treatment, preventing fungemia recurrence within 30 days. Infected patients had significantly longer hospital stays than colonized patients (100 vs. 45 days; p = .023). Hospital mortality rates were 46.7% and 25% in the infected and fungemia patients, respectively. Simultaneous outbreaks of multidrug-resistant bacteria were documented. CONCLUSIONS: This study underscores the severity of a C. auris outbreak at a referral hospital in Peru, highlighting its significant impact on patient outcomes and healthcare resources. The high prevalence of fluconazole-resistant isolates, leading to prolonged hospital stay and high mortality rates, particularly in cases of fungemia, underscores the critical need for effective infection prevention and control strategies.

Antifungal activity of synthetic xanthenone against fluconazole-resistant Candida auris and its mechanism of action.

Candida auris, an emerging multidrug-resistant fungal pathogen discovered in Japan in 2009, poses a significant global health threat, with infections reported in about 25 countries. The escalation of drug-resistant strains underscores the urgent need for new treatment options. This study aimed to investigate the antifungal potential of 2,3,4,4a-tetrahydro-1H-xanthen-1-one (XA1) against C. auris, as well as its mechanism of action and toxic profile. The antifungal activity of XA1 was first evaluated by determining the minimum inhibitory concentration (MIC), time-kill kinetics and biofilm inhibition. In addition, structural changes, membrane permeability, reactive oxygen species (ROS) production, and in vitro and in vivo toxicity of C. auris after exposure to XA1 were investigated. The results indicated that XA1 exhibited an MIC of 50 µg/mL against C. auris, with time-kill kinetics highlighting its efficacy. Field emission scanning electron microscopy (FE-SEM) showed structural damage in XA1-treated cells, supported by increased membrane permeability leading to cell death. Furthermore, XA1 induced ROS production and significantly inhibited biofilm formation. Importantly, XA1 exhibited low cytotoxicity in human epidermal keratinocytes (HaCaT), with a cell viability of over 90 % at 6.25 µg/mL. In addition, an LD50 of 17.68 µg/mL was determined in zebrafish embryos 24 h post fertilization (hpf), with developmental delay observed at prolonged exposure at 6.25 µg/mL (48-96 hpf). These findings position XA1 as a promising candidate for further research and development of an effective antifungal agent.

Screening of the global health priority BoxⓇ reveals potential new disinfectants against the emerging multidrug-resistant pathogen Candida auris.

BACKGROUND: Candida auris has been identified by the World Health Organization as a critical pathogen due to its invasive nature, resistance to multiple drugs, and high mortality rates in hospital outbreaks. This fungus can persist on surfaces and human skin for extended periods, complicating infection control efforts. The need for effective disinfection strategies is urgent, as current disinfectants are often ineffective against C. auris biofilms. OBJECTIVE: The study aimed to identify potential disinfectants from a collection of 240 compounds in the Global Health Priority Box® that are effective against C. auris, particularly strains resistant to existing options. METHODS: The research employed a screening protocol using a fluconazole-resistant strain of C. auris (149/23). Antifungal activity was assessed using the microdilution method to determine Minimum Inhibitory Concentrations (MICs) and Minimum Fungicidal Concentrations (MFCs). Additional assays were conducted to evaluate biofilm inhibition, biofilm eradication, cell membrane integrity, nucleotide leakage, sorbitol protection assay, efflux pump inhibition, and hemolysis assay. RESULTS: Two compounds, Hydramethylnon (MMV1577471) and Flufenerim (MMV1794206), demonstrated significant inhibitory effects against C. auris. Hydramethylnon exhibited potent antifungal activity, inhibiting up to 93 % of fungal growth with an MFC of 16 µg/mL. Flufenerim inhibited up to 58 % of fungal growth, showing fungistatic action with an MFC greater than 4 µg/mL. Biofilm inhibition tests showed that both compounds significantly inhibited biofilm formation, with increased efficacy at higher concentrations. Both compounds showed eradication rates in both stages. Furthermore, Hydramethylnon and Flufenerim did not affect cell membrane integrity or nucleotide leakage, suggesting a mode of action not reliant on disrupting these cellular components. The sorbitol protection assay revealed that neither compound caused cell wall damage. In the efflux pump inhibition assay, Hydramethylnon did not activate efflux pumps, while Flufenerim activated efflux pumps, reducing its effectiveness. Hemocompatibility assay showed safety. CONCLUSION: The study highlights Hydramethylnon and Flufenerim as promising candidates for further development as disinfectants, offering potential solutions to the urgent need for effective disinfection agents against C. auris. The findings underscore the value of screening compound collections to identify novel antifungal agents and understand their mechanisms of action, thereby contributing to the advancement of new disinfection strategies in healthcare settings.

Current knowledge and practice of Candida auris screening in France: A nationwide survey from the French Society of Medical Mycology (SFMM).

Due to large outbreaks observed worldwide, Candida auris has emerged as a major threat to healthcare facilities. To prevent these phenomena, a systematic screening should be performed in patients transferred from regions where the pathogen is highly endemic. In this study, we recorded and analyzed French mycologists' current knowledge and practice regarding C. auris screening and diagnosis. Thirty-six centers answered an online questionnaire. Only 11 (30.6 %) participants were aware of any systematic screening for C. auris for patients admitted to their hospital. In the case of post-admission screening, axillae/groins (n = 21), nares (n = 7), rectum (n = 9), and mouth (n = 6) alone or various combinations were the body sites the most frequently sampled. Only six centers (8.3 %) reported using a commercially available plate allowing the differentiation of C. auris colonies from that of other Candida species, while five laboratories (13.8 %) had implemented a C. auris-specific qPCR. Considering the potential impact on infected patients and the risk of disorganization in the care of patients, it is crucial to remember to biologists and clinicians the utmost importance of systematic screening on admission.

The Light-activated Effect of Natural Anthraquinone Parietin against Candida auris and Other Fungal Priority Pathogens.

Antimicrobial photodynamic therapy (aPDT) is an evolving treatment strategy against human pathogenic microbes such as the Candida species, including the emerging pathogen C. auris. Using a modified EUCAST protocol, the light-enhanced antifungal activity of the natural compound parietin was explored. The photoactivity was evaluated against three separate strains of five yeasts, and its molecular mode of action was analysed via several techniques, i.e., cellular uptake, reactive electrophilic species (RES), and singlet oxygen yield. Under experimental conditions (λ = 428 nm, H = 30 J/cm2, PI = 30 min), microbial growth was inhibited by more than 90% at parietin concentrations as low as c = 0.156 mg/L (0.55 µM) for C. tropicalis and Cryptococcus neoformans, c = 0.313 mg/L (1.10 µM) for C. auris, c = 0.625 mg/L (2.20 µM) for C. glabrata, and c = 1.250 mg/L (4.40 µM) for C. albicans. Mode-of-action analysis demonstrated fungicidal activity. Parietin targets the cell membrane and induces cell death via ROS-mediated lipid peroxidation after light irradiation. In summary, parietin exhibits light-enhanced fungicidal activity against all Candida species tested (including C. auris) and Cryptococcus neoformans, covering three of the four critical threats on the WHO's most recent fungal priority list.