Antifungal susceptibility and virulence determinants profile of candida species isolated from patients with candidemia.

Candida is the most prevalent fungal bloodstream infection (BSI) with a high mortality rate among hospitalized patients. Another concern facing physicians is rising global incidence of drug-resistant Candida. This study aimed to characterize the prevalence, antifungal susceptibility, biofilm formation, and virulence genes (HWP1, ALS1, SAP2) of different Candida spp. isolated from patients with candidemia. 52 isolates of Candida spp. were identified from blood cultures by chromogenic Candida agar and confirmed by the VITEK 2 system. Isolates were tested for antifungal susceptibility by disk diffusion and VITEK 2 system. Biofilm formation and investigated genes were detected by the Congo red method and conventional PCR, respectively. Candida spp. caused 2.3% of detected BSIs, of which 32.7% were caused by Candida albicans (C. albicans) and 67.3% by non-albicans Candida (NAC), with the predominance of C. tropicalis (25%), followed by C. parapsilosis (17.3%), and C. krusei (13.5%). The susceptibility rates to fluconazole, voriconazole, caspofungin, micafungin, amphotericin B, and flucytosine were 64.7%, 76.5%, 100.0%, 100%, 100.0%, and 100.0% in C. albicans, while 53.6%, 71.4%, 91.4%, 91.4%, 94.3%, and 94.3% in NAC, respectively. Biofilm production, HWP1, ALS1, and SAP2 were detected in 70.6%, 82.4%, 76.5%, and 52.9% of C. albicans and 74.3%, 85.7%, 80.0%, and 48.6% of NAC, respectively. There is remarkable shift to NAC BSIs and high azole resistance. Antifungal stewardship and analysis of risk factors associated with this shift are needed.

Treatment of vaginitis caused by non-albicans Candida species.

INTRODUCTION: In the face of increased frequency of non-albicans Candida vulvovaginitis (VVC) reported worldwide, there is a paucity of effective oral and topical antifungal drugs available. Drug selection is further handicapped by an absence of data of clinical efficacy of available antifungal drugs for these infections. AREAS COVERED: In this review, attention is directed at the cause of drug shortage as well as increased frequency of non-albicans Candida (NAC) vulvovaginitis. There is widespread recognition of reduced in vitro azole drug susceptibility in NAC species. Moreover, antifungal susceptibility tests have not been standardized or validated for NAC isolates, hence clinicians rely on an element of empiricism especially given the absence of randomized controlled comparative studies targeting NAC species. Clinical spectrum of NAC species isolates is highly variable with ongoing difficulty in determining a causal role in symptomatic patients. EXPERT OPINION: We have entered the era of demand for Candida species-specific therapy and although consensus treatment guidelines are emerging, new antifungal agents that target these multiple-azole resistant or relatively resistant vaginal NAC species are urgently needed.

Silver(I) complexes with voriconazole as promising anti-Candida agents.

Recognizing that metal ions play an important role in modifying the pharmacological properties of known organic-based drugs, the present manuscript addresses the complexation of the antifungal agent voriconazole (vcz) with the biologically relevant silver(I) ion as a strategy for the development of new antimycotics. The synthesized silver(I) complexes with vcz were characterized by mass spectrometry, IR, UV-Vis and NMR spectroscopy and single-crystal X-ray diffraction analysis. The crystallographic results showed that complexes {[Ag(vcz)(H2O)]CH3SO3}n (1), {[Ag(vcz)2]BF4}n (2) and {[Ag(vcz)2]PF6}n (3) have polymeric structures in the solid state, in which silver(I) ions have a distorted tetrahedral geometry. On the other hand, DFT calculations revealed that the investigated silver(I) complexes 1-3 in DMSO exist as linear [Ag(vcz-N2)(vcz-N19)]+ (1a), [Ag(vcz-N2)(vcz-N4)]+ (2a) and [Ag(vcz-N4)2]+ (3a) species, respectively. The evaluated complexes showed an enhanced anti-Candida activity compared to the parent drug with minimal inhibitory concentration (MIC) values in the range of 0.02-1.05 µM. In comparison with vcz, the corresponding silver(I) complexes showed better activity in prevention hyphae and biofilm formation of C. albicans, indicating that they could be considered as promising agents against Candida that significantly inhibit its virulence. Also, these complexes are much better inhibitors of ergosterol synthesis in the cell membrane of C. albicans at the concentration of 0.5 × MIC. This is also confirmed by a molecular docking, which revealed that complexes 1a - 3a showed better inhibitory activity than vcz against the sterol 14α-demethylase enzyme cytochrome P450 (CYP51B), which plays a crucial role in the formation of ergosterol.

Antifungal activity of bio-active cell-free culture extracts and volatile organic compounds (VOCs) synthesised by endophytic fungal isolates of Garden Nasturtium.

Antimicrobial resistance in fungal pathogens (both human and plant) is increasing alarmingly, leading to massive economic crises. The existing anti-fungal agents are becoming ineffective, and the situation worsens on a logarithmic scale. Novel antifungals from unique natural sources are highly sought to cope sustainably with the situation. Metabolites from endophytic microbes are the best-fitted alternatives in this case. Endophytes are the untapped sources of 'plants' internal microbial population' and are promising sources of effective bio-therapeutic agents. Fungal endophytes were isolated from Tropaeolum majus and checked for antifungal activity against selected plant and human pathogens. Bioactive metabolites were identified through chromatographic techniques. The mode of action of those metabolites was evaluated through various spectroscopic techniques. The production of antifungal metabolite was optimized also. In particular VOCs (volatile organic compounds) of TML9 were tested in vitro for their anti-phytopathogenic activity. Ethyl acetate (EA) extract of cell-free culture components of Colletotrichum aenigma TML3 exhibited broad-spectrum antifungal activity against four species of Candida and the major constituents reported were 6-pentyl-2H-pyran-2-one, 2-Nonanone, 1 propanol 2-amino. The volatile metabolites, trans-ocimene, geraniol, and 4-terpinyl acetate, produced from Curvularia lunata TML9, inhibited the growth of some selected phyto pathogens. EA extract hampered the biofilm formation, minimised the haemolytic effect, and blocked the transformation of Candida albicans (MTCC 4748) from yeast to hyphal form with a Minimum Fungicidal Concentration (MFC) of 200-600 µg mL-1. Central carbohydrate metabolism, ergosterol synthesis, and membrane permeability were adversely affected and caused the lethal leakage of necessary macromolecules of C. albicans. Volatile metabolites inhibited the growth of phytopathogens i.e., Rhizoctonia solani, Alternaria alternata, Botrytis cinerea, Cercospora beticola, Penicillium digitatum, Aspergillus fumigatus, Ceratocystis ulmi, Pythium ultimum up to 89% with an IC50 value of 21.3-69.6 µL 50 mL-1 and caused leakage of soluble proteins and other intracellular molecules. Citrusy sweet odor volatiles of TML9 cultured in wheat-husk minimised the infections of Penicillium digitatum (green mold), in VOC-exposed sweet oranges (Citrus sinensis). Volatile and non-volatile antifungal metabolites of these two T. majus endophytes hold agricultural and pharmaceutical interests. Metabolites of TML3 have strong anti-Candida activity and require further assessment for therapeutic applications. Also, volatile metabolites of TML9 can be further studied as a source of antifungals. The present investigational outcomes bio-prospects the efficacy of fungal endophytes of Garden Nasturtium.

Exploring the antifungal, antibiofilm and antienzymatic potential of Rottlerin in an in vitro and in vivo approach.

Candida species have been responsible for a high number of invasive infections worldwide. In this sense, Rottlerin has demonstrated a wide range of pharmacological activities. Therefore, this study aimed to evaluate the antifungal, antibiofilm and antivirulence activity of Rottlerin in vitro against Candida spp. and its toxicity and antifungal activity in vivo. Rottlerin showed antifungal activity against all yeasts evaluated, presenting Minimum Inhibitory and Fungicidal Concentration (MIC and MFC) values of 7.81 to > 1000 µg/mL. Futhermore, it was able to significantly inhibit biofilm production, presenting Biofilm Inhibitory Concentration (MICB50) values that ranged from 15.62 to 250 µg/mL and inhibition of the cell viability of the biofilm by 50% (IC50) from 2.24 to 12.76 µg/mL. There was a considerable reduction in all hydrolytic enzymes evaluated, with emphasis on hemolysin where Rottlerin showed a reduction of up to 20%. In the scanning electron microscopy (SEM) analysis, Rottlerin was able to completely inhibit filamentation by C. albicans. Regarding in vivo tests, Rottlerin did not demonstrate toxicity at the therapeutic concentrations demonstrated here and was able to increase the survival of C. elegans larvae infected. The results herein presented are innovative and pioneering in terms of Rottlerin's multipotentiality against these fungal infections.

Antifungal Potential of Secondary Metabolites Derived from Arcangelisia flava (L.) Merr.: An Analysis of In Silico Enzymatic Inhibition and In Vitro Efficacy against Candida Species.

Considering the escalating resistance to conventional antifungal medications, it is critical to identify novel compounds that can efficiently counteract this challenge. The purpose of this research was to elucidate the fungicidal properties of secondary metabolites derived from Arcangelisia flava, with a specific focus on their efficacy against Candida species. This study utilized a combination approach comprising laboratory simulations and experiments to discern and evaluate the biologically active constituents present in the dichloromethane extract of A. flava. The in vitro experiments demonstrated that compounds 1 (palmatine) and 2 (fibraurin) exhibited antifungal properties. The compounds exhibited minimum inhibitory concentrations (MICs) ranging from 15.62 to 62.5 µg/mL against Candida sp. Moreover, compound 1 demonstrated a minimum fungicidal concentration (MFC) of 62.5 µg/mL against Candida glabrata and C. krusei. In contrast, compound 2 exhibited an MFC of 125 µg/mL against both Candida species. Based on a molecular docking study, it was shown that compounds 1 and 2 have a binding free energy of -6.6377 and -6.7075 kcal/mol, respectively, which indicates a strong affinity and specificity for fungal enzymatic targets. This study utilized pharmacophore modeling and Density Functional Theory (DFT) simulations to better understand the interaction dynamics and structural properties crucial for antifungal activity. The findings underscore the potential of secondary metabolites derived from A. flava to act as a foundation for creating novel and highly efficient antifungal treatments, specifically targeting fungal diseases resistant to existing treatment methods. Thus, the results regarding these compounds can provide references for the next stage in antifungal drug design. Further investigation is necessary to thoroughly evaluate these natural substances' clinical feasibility and safety characteristics, which show great potential as antifungal agents.

The laboratory investigation, management, and infection prevention and control of Candida auris: a narrative review to inform the 2024 national guidance update in England.

The emergent fungal pathogen Candida auris is increasingly recognised as an important cause of healthcare-associated infections globally. It is highly transmissible, adaptable, and persistent, resulting in an organism with significant outbreak potential that risks devastating consequences. Progress in the ability to identify C. auris in clinical specimens is encouraging, but laboratory diagnostic capacity and surveillance systems are lacking in many countries. Intrinsic resistance to commonly used antifungals, combined with the ability to rapidly acquire resistance to therapy, substantially restricts treatment options and novel agents are desperately needed. Despite this, outbreaks can be interrupted, and mortality avoided or minimised, through the application of rigorous infection prevention and control measures with an increasing evidence base. This review provides an update on epidemiology, the impact of the COVID-19 pandemic, risk factors, identification and typing, resistance profiles, treatment, detection of colonisation, and infection prevention and control measures for C. auris. This review has informed a planned 2024 update to the United Kingdom Health Security Agency (UKHSA) guidance on the laboratory investigation, management, and infection prevention and control of Candida auris. A multidisciplinary response is needed to control C. auris transmission in a healthcare setting and should emphasise outbreak preparedness and response, rapid contact tracing and isolation or cohorting of patients and staff, strict hand hygiene and other infection prevention and control measures, dedicated or single-use equipment, appropriate disinfection, and effective communication concerning patient transfers and discharge.

A novel functionalized CuTi hybrid nanocomposites: facile one-pot mycosynthesis, characterization, antimicrobial, antibiofilm, antifouling and wastewater disinfection performance.

BACKGROUND: The continuous progress in nanotechnology is rapid and extensive with overwhelming futuristic aspects. Through modernizing inventive synthesis protocols, a paradigm leapfrogging in novelties and findings are channeled toward fostering human health and sustaining the surrounding environment. Owing to the overpricing and jeopardy of physicochemical synthesizing approaches, the quest for ecologically adequate schemes is incontestable. By developing environmentally friendly strategies, mycosynthesis of nanocomposites has been alluring. RESULTS: Herein, a novel architecture of binary CuO and TiO2 in nanocomposites form was fabricated using bionanofactory Candida sp., for the first time. For accentuating the structural properties of CuTi nanocomposites (CuTiNCs), various characterization techniques were employed. UV-Vis spectroscopy detected SPR at 350 nm, and XRD ascertained the crystalline nature of a hybrid system. However, absorption peaks at 8, 4.5, and 0.5 keV confirmed the presence of Cu, Ti and oxygen, respectively, in an undefined assemblage of polygonal-spheres of 15-75 nm aggregated in the fungal matrix of biomolecules as revealed by EDX, SEM and TEM. However, FTIR, ζ-potential and TGA reflected long-term stability (- 27.7 mV) of self-functionalized CuTiNCs. Interestingly, a considerable and significant biocide performance was detected at 50 µg/mL of CuTiNCs against some human and plant pathogens, compared to monometallic counterparts. Further, CuTiNCs (200 µg/mL) ceased significantly the development of Staphylococcus aureus, Pseudomonas aeruginosa and Candida albicans biofilms by 80.3 ± 1.4, 68.7 ± 3.0 and 55.7 ± 3.0%, respectively. Whereas, 64.63 ± 3.5 and 89.82 ± 4.3% antimicrofouling potentiality was recorded for 100 and 200 µg/ml of CuTiNCs, respectively; highlighting their destructive effect against marine microfoulers cells and decaying of their extracellular polymeric skeleton as visualized by SEM. Moreover, CuTiNCs (100 and 200 µg/ml) exerted significantly outstanding disinfection potency within 2 h by reducing the microbial load (i.e., total plate count, mold & yeast, total coliforms and faecal Streptococcus) in domestic and agricultural effluents reached >50%. CONCLUSION: The synergistic efficiency provided by CuNPs and TiNPs in mycofunctionalized CuTiNCs boosted its recruitment as antiphytopathogenic, antibiofilm, antimicrofouling and disinfectant agent in various realms.

Synthesis, In Silico Study, and In Vitro Antifungal Activity of New 5-(1,3-Diphenyl-1H-Pyrazol-4-yl)-4-Tosyl-4,5-Dihydrooxazoles.

The increase in multi-drug resistant Candida strains has caused a sharp rise in life-threatening fungal infections in immunosuppressed patients, including those with SARS-CoV-2. Novel antifungal drugs are needed to combat multi-drug-resistant yeasts. This study aimed to synthesize a new series of 2-oxazolines and evaluate the ligands in vitro for the inhibition of six Candida species and in silico for affinity to the CYP51 enzymes (obtained with molecular modeling and protein homology) of the same species. The 5-(1,3-diphenyl-1H-pyrazol-4-yl)-4-tosyl-4,5-dihydrooxazoles 6a-j were synthesized using the Van Leusen reaction between 1,3-diphenyl-4-formylpyrazoles 4a-j and TosMIC 5 in the presence of K2CO3 or KOH without heating, resulting in short reaction times, high compound purity, and high yields. The docking studies revealed good affinity for the active site of the CYP51 enzymes of the Candida species in the following order: 6a-j > 4a-j > fluconazole (the reference drug). The in vitro testing of the compounds against the Candida species showed lower MIC values for 6a-j than 4a-j, and for 4a-j than fluconazole, thus correlating well with the in silico findings. According to growth rescue assays, 6a-j and 4a-j (like fluconazole) inhibit ergosterol synthesis. The in silico toxicity assessment evidenced the safety of compounds 6a-j, which merit further research as possible antifungal drugs.

Disclosing the Antifungal Mechanisms of the Cyclam Salt H4[H2(4-CF3PhCH2)2Cyclam]Cl4 against Candida albicans and Candida krusei.

Mycoses are one of the major causes of morbidity/mortality among immunocompromised individuals. Considering the importance of these infections, the World Health Organization (WHO) defined a priority list of fungi for health in 2022 that include Candida albicans as belonging to the critical priority group and Pichia kudriavzevii (Candida krusei) to the medium priority group. The existence of few available antifungal drugs, their high toxicity, the acquired fungal resistance, and the appearance of new species with a broader spectrum of resistance, points out the need for searching for new antifungals, preferably with new and multiple mechanisms of action. The cyclam salt H4[H2(4-CF3PhCH2)2Cyclam]Cl4 was previously tested against several fungi and revealed an interesting activity, with minimal inhibitory concentration (MIC) values of 8 µg/mL for C. krusei and of 128 µg/mL for C. albicans. The main objective of the present work was to deeply understand the mechanisms involved in its antifungal activity. The effects of the cyclam salt on yeast metabolic viability (resazurin reduction assay), yeast mitochondrial function (JC-1 probe), production of reactive oxygen species (DCFH-DA probe) and on intracellular ATP levels (luciferin/luciferase assay) were evaluated. H4[H2(4-CF3PhCH2)2Cyclam]Cl4 induced a significant decrease in the metabolic activity of both C. albicans and C. krusei, an increase in Reactive Oxygen Species (ROS) production, and an impaired mitochondrial function. The latter was observed by the depolarization of the mitochondrial membrane and decrease in ATP intracellular levels, mechanisms that seems to be involved in the antifungal activity of H4[H2(4-CF3PhCH2)2Cyclam]Cl4. The interference of the cyclam salt with human cells revealed a CC50 value against HEK-293 embryonic kidney cells of 1.1 µg/mL and a HC10 value against human red blood cells of 0.8 µg/mL.

Virulence factors, antifungal susceptibility and molecular profile in Candida species isolated from the hands of health professionals before and after cleaning with 70% ethyl alcohol-based gel.

Fungal infections in neonatal intensive care units (NICU) are mainly related to Candida species, with high mortality rates. They are predominantly of endogenous origin, however, cross-infection transmitted by healthcare professionals' hands has occurred. The aim of this study was to identify Candida species isolated from the hands of healthcare professionals in a NICU before and after hygiene with 70% ethanol-based gel and evaluate virulence factors DNase, phospholipase, proteinase, hemolysin, biofilm biomass production, and metabolic activity. In vitro antifungal susceptibility testing and similarity by random amplified polymorphic DNA (RAPD) were also performed. C. parapsilosis complex was the most frequent species (57.1%); all isolates presented at least one virulence factor; three isolates (Candida parapsilosis complex) were resistant to amphotericin B, two (Candida famata [currently Debaryomyces hansenii] and Candida guilliermondii [currently Meyerozyma guilliermondii]) was resistant to micafungin, and six (Candida parapsilosis complex, Candida guilliermondii [=Meyerozyma guilliermondii], Candida viswanathi, Candida catenulata [currently Diutina catenulata] and Candida lusitaniae [currently Clavispora lusitaniae]) were resistant to fluconazole. Molecular analysis by RAPD revealed two clusters of identical strains that were in the hands of distinct professionals. Candida spp. were isolated even after hygiene with 70% ethanol-based gel, highlighting the importance of stricter basic measures for hospital infection control to prevent nosocomial transmission.

The fungicidal effectiveness of 2-Chloro-3-hydrazinylquinoxaline, a newly developed quinoxaline derivative, against Candida species.

BACKGROUND: Candida represents a prevalent fungal infection, notable for its substantial implications on morbidity and mortality rates. In the landscape of prospective treatments, quinoxaline derivatives emerge as a category of compact compounds exhibiting notable potential in addressing infections. These derivatives showcase promising antimicrobial efficacy coupled with favorable pharmacokinetic and safety characteristics. AIMS: The central aim of this investigation was to examine the antifungal characteristics of 2-Chloro-3-hydrazinylquinoxaline against diverse strains of Candida and Aspergillus in vitro. Additionally, we endeavored to assess the in vivo efficacy of 2-Chloro-3-hydrazinylquinoxaline using a murine model for oral candidiasis induced by C. albicans cells ATCC 10231. RESULTS: 2-Chloro-3-hydrazinylquinoxaline demonstrated noteworthy effectiveness when tested against various reference strains of Candida species. It exhibited heightened efficacy, particularly against Candida krusei isolates. However, its performance against Candida albicans, Candida tropicalis, Candida glabrata, Candida parapsilosis, and Candida auris isolates exhibited variability. Notably, 2-Chloro-3-hydrazinylquinoxaline manifests variable efficacy against Aspergillus fumigatus, Aspergillus niger, Aspergillus terreus and Aspergillus flavus and no effect against Aspergillus brasiliensis. In a murine model, 2-Chloro-3-hydrazinylquinoxaline exhibited significant efficacy in combating the C. albicans cells ATCC 10231 strain, underscoring its potential as a viable treatment option. CONCLUSION: 2-Chloro-3-hydrazinylquinoxaline has demonstrated substantial potential in effectively addressing various Candida and Aspergillus species, showcasing dual attributes of antifungal and anti-inflammatory properties. However, to attain a more comprehensive understanding of its therapeutic capabilities, further investigations, incorporating additional tests and experiments, are imperative.

Understanding the mechanism of action of protease inhibitors in controlling the growth of the Candida Genus: potential candidates for development of new antifungal molecules.

There is a growing imperative for research into alternative compounds for the treatment of the fungal infections. Thus, many studies have focused on the analysis of antifungal proteins and peptides from different plant sources. Among these molecules are protease inhibitors (PIs). Previously, PIs present in the peptide-rich fractions called PEF1, PEF2 and PEF3 were identified from Capsicum chinense seeds, which have strong activity against phytopathogenic fungi. The aim of this study was to evaluate the mechanism of action and antimicrobial activity of PIs from PEF2 and PEF3 on the growth of yeasts of the genus Candida. In this work, analyses of their antimicrobial activity and cell viability were carried out. Subsequently, the mechanism of action by which the PIs cause the death of the yeasts was evaluated. Cytotoxicity was assessed in vitro by erythrocytes lysis and in vivo in Galleria mellonella larvae. PEF2 and PEF3 caused 100% of the growth inhibition of C. tropicalis and C. buinensis. For C. albicans inhibition was approximately 60% for both fractions. The PEF2 and PEF3 caused a reduction in mitochondrial functionality of 54% and 46% for C. albicans, 26% and 30% for C. tropicalis, and 71% and 68% for C. buinensis, respectively. These fractions induced morphological alterations, led to membrane permeabilization, elevated ROS levels, and resulted in necrotic cell death in C. tropicalis, whilst demonstrating low toxicity toward host cells. From the results obtained here, we intend to contribute to the understanding of the action of PIs in the control of fungal diseases of medical importance.

Oral candidiasis in liver transplant patients: species identification and antifungal susceptibility profile.

OBJECTIVE: This study aimed to verify oral candidiasis, identify the causative species, and investigate the antifungal susceptibility of yeasts isolated from liver transplant patients. METHODS: A descriptive analysis of 97 patients who underwent liver transplantation was conducted at a hospital. Two clinical examinations (Collections A and B) of the oral cavity were performed. Oral material was collected from all patients, inoculated in Sabouraud Dextrose Agar, and incubated at 35℃ for 48 hours. Samples were identified by molecular sequencing of the internal trascribed space region of rDNA. RESULTS: An antifungal susceptibility test with fluconazole, amphotericin B, and micafungin was performed using the Clinical and Laboratory Standards Institute yeast broth microdilution method. Among the patients, 15 presented with oral candidiasis: eight in Collection A and seven in Collection B. The primary type of candidiasis was atrophic, followed by pseudomembranous candidiasis. The most prevalent species was Candida albicans (nine), followed by Candida glabrata (three), Candida tropicalis (two), and Candida dubliniensis (one). Regarding susceptibility to fluconazole, of the 15 samples, 11 were susceptible, three were susceptible in a dose-dependent manner, and one was resistant. CONCLUSION: The most commonly identified type of candidiasis was atrophic, with C. albicans and C. glabrata being the most prevalent causative species. One fluconazole-resistant isolate each of C. tropicalis and C. albicans were identified.

Spectrum of activity and mechanisms of azole-bisphosphonate synergy in pathogenic Candida.

Candidiasis places a significant burden on human health and can range from common superficial vulvovaginal and oral infections to invasive diseases with high mortality. The most common Candida species implicated in human disease is Candida albicans, but other species like Candida glabrata are emerging. The use of azole antifungals for treatment is limited by increasing rates of resistance. This study explores repositioning bisphosphonates, which are traditionally used for osteoporosis, as antifungal synergists that can improve and revitalize the use of azoles. Risedronate, alendronate, and zoledronate (ZOL) were tested against isolates from six different species of Candida, and ZOL produced moderate antifungal activity and strong synergy with azoles like fluconazole (FLC), particularly in C. glabrata. FLC:ZOL combinations had increased fungicidal and antibiofilm activity compared to either drug alone, and the combination prevented the development of antifungal resistance. Mechanistic investigations demonstrated that the synergy was mediated by the depletion of squalene, resulting in the inhibition of ergosterol biosynthesis and a compromised membrane structure. In C. glabrata, synergy compromised the function of membrane-bound multidrug transporters and caused an accumulation of reactive oxygen species, which may account for its acute sensitivity to FLC:ZOL. The efficacy of FLC:ZOL in vivo was confirmed in a Galleria mellonella infection model, where combinations improved the survival of larvae infected with C. albicans and C. glabrata to a greater extent than monotherapy with FLC or ZOL, and at reduced dosages. These findings demonstrate that bisphosphonates and azoles are a promising new combination therapy for the treatment of topical candidiasis. IMPORTANCE: Candida is a common and often very serious opportunistic fungal pathogen. Invasive candidiasis is a prevalent cause of nosocomial infections with a high mortality rate, and mucocutaneous infections significantly impact the quality of life of millions of patients a year. These infections pose substantial clinical challenges, particularly as the currently available antifungal treatment options are limited in efficacy and often toxic. Azoles are a mainstay of antifungal therapy and work by targeting the biosynthesis of ergosterol. However, there are rising rates of acquired azole resistance in various Candida species, and some species are considered intrinsically resistant to most azoles. Our research demonstrates the promising therapeutic potential of synergistically enhancing azoles with non-toxic, FDA-approved bisphosphonates. Repurposing bisphosphonates as antifungal synergists can bypass much of the drug development pipeline and accelerate the translation of azole-bisphosphonate combination therapy.

Drug-resistant oral candidiasis in patients with HIV infection: a systematic review and meta-analysis.

BACKGROUND: Oral candidiasis (OC) is a prevalent opportunistic infection in patients with human immunodeficiency virus (HIV) infection. The increasing resistance to antifungal agents in HIV-positive individuals suffering from OC raised concerns. Thus, this study aimed to investigate the prevalence of drug-resistant OC in HIV-positive patients. METHODS: Pubmed, Web of Science, Scopus, and Embase databases were systematically searched for eligible articles up to November 30, 2023. Studies reporting resistance to antifungal agents in Candida species isolated from HIV-positive patients with OC were included. Baseline characteristics, clinical features, isolated Candida species, and antifungal resistance were independently extracted by two reviewers. The pooled prevalence with a 95% confidence interval (CI) was calculated using the random effect model or fixed effect model. RESULTS: Out of the 1942 records, 25 studies consisting of 2564 Candida species entered the meta-analysis. The pooled prevalence of resistance to the antifungal agents was as follows: ketoconazole (25.5%, 95% CI: 15.1-35.8%), fluconazole (24.8%, 95% CI: 17.4-32.1%), 5-Flucytosine (22.9%, 95% CI: -13.7-59.6%), itraconazole (20.0%, 95% CI: 10.0-26.0%), voriconazole (20.0%, 95% CI: 1.9-38.0%), miconazole (15.0%, 95% CI: 5.1-26.0%), clotrimazole (13.4%, 95% CI: 2.3-24.5%), nystatin (4.9%, 95% CI: -0.05-10.3%), amphotericin B (2.9%, 95% CI: 0.5-5.3%), and caspofungin (0.1%, 95% CI: -0.3-0.6%). Furthermore, there were high heterogeneities among almost all included studies regarding the resistance to different antifungal agents (I2 > 50.00%, P < 0.01), except for caspofungin (I2 = 0.00%, P = 0.65). CONCLUSIONS: Our research revealed that a significant number of Candida species found in HIV-positive patients with OC were resistant to azoles and 5-fluocytosine. However, most of the isolates were susceptible to nystatin, amphotericin B, and caspofungin. This suggests that initial treatments for OC, such as azoles, may not be effective. In such cases, healthcare providers may need to consider prescribing alternative treatments like polyenes and caspofungin. REGISTRATION: The study protocol was registered in the International Prospective Register of Systematic Reviews as PROSPERO (Number: CRD42024497963).

Comparison of fungemia caused by Candida and non-Candida rare yeasts: a retrospective study from a tertiary care hospital.

Although Candida species are the most common cause of fungemia, non-Candida rare yeasts (NCY) have been increasingly reported worldwide. Although the importance of these yeast infections is recognized, current epidemiological information about these pathogens is limited, and they have variable antifungal susceptibility profiles. In this study, we aimed to evaluate the clinical characteristics for fungemia caused by NCY by comparing with candidemia. The episodes of NCY fungemia between January 2011 and August 2023 were retrospectively evaluated in terms of clinical characteristics, predisposing factor, and outcome. In addition, a candidemia group, including patients in the same period was conducted for comparison. Antifungal susceptibility tests were performed according to the reference method. A total of 85 patients with fungemia episodes were included: 25 with NCY fungemia and 60 with candidemia. Fluconazole had high minimal inhibitory concentration (MIC) values against almost all NCY isolates. The MIC values for voriconazole, posaconazole, and amphotericin B were ≤ 2 µg/ml, and for caspofungin and anidulafungin were ≥ 1 µg/ml against most of isolates. Hematological malignancies, immunosuppressive therapy, neutropenia and prolonged neutropenia, polymicrobial bacteremia/fungemia, preexposure to antifungal drugs, and breakthrough fungemia were associated with NCY fungemia, whereas intensive care unit admission, diabetes mellitus, urinary catheters, and total parenteral nutrition were associated with candidemia. In conclusion, the majority of fungemia due to NCY species was the problem, particularly in hematology units and patients with hematological malignancy. Preexposure to antifungal drugs likely causes a change in the epidemiology of fungemia in favor of non-albicans Candida and/or NCY.

Among all fungemia episodes, hematological malignancies, immunosuppressive therapy, neutropenia, and preexposure to antifungals were risk factors for non-Candida yeast fungemia; diabetes mellitus, urinary catheters, and total parenteral nutrition were risks for candidemia.

Epidemiology, clinical characteristics, outcome and biofilm forming properties in candidaemia: A single-centre retrospective 4-year analysis from Hungary.

BACKGROUND: Candidaemia is a life-threatening disease that is associated with high mortality, especially in intensive care units (ICUs). The number of comprehensive studies dealing with the epidemiologic characteristics of biofilm-related properties is limited. OBJECTIVE: This study evaluated the clinical characteristics of candidaemia, to assess the biofilm-forming properties of isolates, and to identify the risk factors of mortality. PATIENTS AND METHODS: A total of 149 candidaemia episodes from the University of Debrecen, Clinical Centre, between January 2020 and December 2023 were investigated retrospectively. The susceptibility of Candida isolates to fluconazole, amphotericin B, anidulafungin, caspofungin, and micafungin was evaluated and compared to the susceptibility of 1-day-old biofilms. Multivariate logistic regression analysis was applied to identify the independent predictors of 30-day mortality rate. RESULTS: The most common Candida species was Candida albicans (41%), followed by C. parapsilosis (20%), C. glabrata (14%), C. tropicalis (13%), rare Candida species (7%), and C. krusei (5%). Sixty-six percent of Candida isolates were biofilm formers and 44% had high metabolic activity. The 30-day mortality rate was 52%, which was higher in ICUs (65%). The logistic regression analysis revealed several factors significantly influencing mortality including ICU admission (odds ratio [OR] 2.99, 95% confidence interval [CI] 1.17-8.04, p = 0.025), fluconazole treatment (OR 4.12, 95% CI 1.62-11.42, p = .004), and pneumonia (OR 0.261, 95% CI 0.1-0.67, p = .006). CONCLUSIONS: This comprehensive analysis supports the better characterisation of candidaemia in healthcare settings, which ultimately may reduce mortality among patients.

A dual-targeting antifungal is effective against multidrug-resistant human fungal pathogens.

Drug-resistant fungal infections pose a significant threat to human health. Dual-targeting compounds, which have multiple targets on a single pathogen, offer an effective approach to combat drug-resistant pathogens, although ensuring potent activity and high selectivity remains a challenge. Here we propose a dual-targeting strategy for designing antifungal compounds. We incorporate DNA-binding naphthalene groups as the hydrophobic moieties into the host defence peptide-mimicking poly(2-oxazoline)s. This resulted in a compound, (Gly0.8Nap0.2)20, which targets both the fungal membrane and DNA. This compound kills clinical strains of multidrug-resistant fungi including Candida spp., Cryptococcus neoformans, Cryptococcus gattii and Aspergillus fumigatus. (Gly0.8Nap0.2)20 shows superior performance compared with amphotericin B by showing not only potent antifungal activities but also high antifungal selectivity. The compound also does not induce antimicrobial resistance. Moreover, (Gly0.8Nap0.2)20 exhibits promising in vivo therapeutic activities against drug-resistant Candida albicans in mouse models of skin abrasion, corneal infection and systemic infection. This study shows that dual-targeting antifungal compounds may be effective in combating drug-resistant fungal pathogens and mitigating fungal resistance.