Concentrations Of Fluconazole Research Articles

Population pharmacokinetics of fluconazole for prevention or treatment of invasive candidiasis in Chinese young infants.

The dosing of fluconazole for young infants remains empirical because of the limited pharmacokinetic (PK) data. We aimed to establish a population PK model and assess the systematic exposure-response of commonly used regimens of fluconazole in Chinese infants.We included infants with a postnatal age of less than 120 days and received intravenous fluconazole. Both scheduled and scavenged plasma samples were collected, and fluconzaole concentration was determined by a validated ultra-performance liquid chromatography-tandem mass spectrometry assay. Population PK analysis was conducted using Phoenix NLME, and then Monte Carlo simulation was conducted to predict the probability of target attainment (PTA) of empirically used regimens of both prophylactic and therapeutic purposes.Based on 304 plasma samples from 183 young infants, fluconazole concentration data was best described by a one-compartment model with first-order elimination. Gestational Age (GA), postnatal age (PNA), and body weight (BW) were included in the final model as CL = 0.02*(GA/214)2.77*(PNA/13)0.24*exp(nCL); V = 1.56*(BW/1435)0.90*exp(nV). Model validation revealed the final model had qualified stability and acceptable predictive properties. Monte Carlo simulation indicated that under the same minimum inhibitory concentration (MIC) value and administration regimen, PTA decreased with GA and PNA. The commonly used prophylactic regimens can meet the clinical need, while higher doses might be needed for treatment of invasive candidiasis.This population PK model of fluconazole discriminated the impact of GA and PNA on CL and BW on V. Dosing adjustment was needed according to the GA and PNA of infants to achieve targeted exposures.

The replacement of ergosterol with alternative sterols affects the physiological function of the yeast plasma membrane, including its H+-ATPase activity and resistance to antifungal drugs

Sterols perform essential structural and signalling functions in living organisms. Ergosterol contributes to the fluidity, permeability, microdomain formation and functionality of proteins in the yeast membrane. In our study, desmosterol was the most successful at compensating for the lack of ergosterol in Saccharomyces cerevisiae, besides stigmasterol and sitosterol. These three sterols supported cell growth without causing severe morphological defects, unlike cholesterol, 7-dehydrocholesterol, lathosterol, cholestanol or lanosterol. Together with ergosterol, they were also able to bring the plasma membrane potential of hem1Δ cells closer to the level of the wild type. In addition, desmosterol conferred even higher thermotolerance to yeast than ergosterol. Some sterols counteracted the antifungal toxicity of polyenes, azoles and terbinafine to hem1Δ cells. Plant sterols (stigmasterol, sitosterol) and desmosterol ensured the glucose-induced activation of H+-ATPase in hem1Δ cells analogously to ergosterol, whereas cholesterol and 7-dehydrocholesterol were less effective. Exogenous ergosterol, stigmasterol, sitosterol, desmosterol and cholesterol also improved the growth of Candida glabrata and Candida albicans in the presence of inhibitory concentration of fluconazole. The proper incorporation of exogenous sterols into the membrane with minimal adverse side effects on membrane functions was mainly influenced by the structure of the sterol acyl chain, and less by their ring structures.

Erg251 has complex and pleiotropic effects on sterol composition, azole susceptibility, filamentation, and stress response phenotypes.

Ergosterol is essential for fungal cell membrane integrity and growth, and numerous antifungal drugs target ergosterol. Inactivation or modification of ergosterol biosynthetic genes can lead to changes in antifungal drug susceptibility, filamentation and stress response. Here, we found that the ergosterol biosynthesis gene ERG251 is a hotspot for point mutations during adaptation to antifungal drug stress within two distinct genetic backgrounds of Candida albicans. Heterozygous point mutations led to single allele dysfunction of ERG251 and resulted in azole tolerance in both genetic backgrounds. This is the first known example of point mutations causing azole tolerance in C. albicans. Importantly, single allele dysfunction of ERG251 in combination with recurrent chromosome aneuploidies resulted in bona fide azole resistance. Homozygous deletions of ERG251 caused increased fitness in low concentrations of fluconazole and decreased fitness in rich medium, especially at low initial cell density. Homozygous deletions of ERG251 resulted in accumulation of ergosterol intermediates consistent with the fitness defect in rich medium. Dysfunction of ERG251, together with FLC exposure, resulted in decreased accumulation of the toxic sterol (14-ɑ-methylergosta-8,24(28)-dien-3β,6α-diol) and increased accumulation of non-toxic alternative sterols. The altered sterol composition of the ERG251 mutants had pleiotropic effects on transcription, filamentation, and stress responses including cell membrane, osmotic and oxidative stress. Interestingly, while dysfunction of ERG251 resulted in azole tolerance, it also led to transcriptional upregulation of ZRT2, a membrane-bound Zinc transporter, in the presence of FLC, and overexpression of ZRT2 is sufficient to increase azole tolerance in wild-type C. albicans. Finally, in a murine model of systemic infection, homozygous deletion of ERG251 resulted in decreased virulence while the heterozygous deletion mutants maintain their pathogenicity. Overall, this study demonstrates that single allele dysfunction of ERG251 is a recurrent and effective mechanism of acquired azole tolerance. We propose that altered sterol composition resulting from ERG251 dysfunction mediates azole tolerance as well as pleiotropic effects on stress response, filamentation and virulence.

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

ABSTRACT 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.

Alteration of β-glucan in the emerging fungal pathogen Candida auris leads to immune evasion and increased virulence

Candida auris is an emerging pathogenic yeast that has been categorized as a global public health threat and a critical priority among fungal pathogens. Despite this, the immune response against C. auris infection is still not well understood. Hosts fight Candida infections through the immune system that recognizes pathogen-associated molecular patterns such as β-glucan, mannan, and chitin on the fungal cell wall. In this study, levels of β-glucan and mannan exposures in C. auris grown under different physiologically relevant stimuli were quantified by flow cytometry-based analysis. Lactate, hypoxia, and sublethal concentration of fluconazole trigger a decrease in surface β-glucan while low pH triggers an increase in β-glucan. There is no inverse pattern between exposure levels of β-glucan and mannan in the cell wall architecture among the three clades. To determine the effect of cell wall remodeling on the immune response, a phagocytosis assay was performed, followed by quantification of released cytokines by ELISA. Lactate-induced decrease in β-glucan leads to reduced uptake of C. auris by PMA-differentiated THP-1 and RAW 264.7 macrophages. Furthermore, reduced production of CCL3/MIP-1⍺ but not TNF-⍺ and IL-10 were observed. An in vivo infection analysis using silkworms reveals that a reduction in β-glucan triggers an increase in the virulence of C. auris. This study demonstrates that β-glucan alteration occurs in C. auris and serves as an escape mechanism from immune cells leading to increased virulence.

Integrated management of cryptococcal meningitis and concurrent opportunistic infections to improve outcomes in advanced HIV disease: a randomised strategy trial.

Mortality associated with HIV-associated cryptococcal meningitis remains high even in the context of clinical trials (24-45% at 10 weeks); mortality at 12-months is up to 78% in resource limited settings. Co-prevalent tuberculosis (TB) is common and preventable, and likely contributes to poor patient outcomes. Innovative strategies to increase TB preventative therapy (TPT) provision and uptake within this high-risk group are needed. The IMPROVE trial (Integrated management of cryptococcal meningitis and concurrent opportunistic infections to improve outcomes in advanced HIV disease) is a nested open label, two arm, randomised controlled strategy trial to evaluate the safety (adverse events) and feasibility (adherence and tolerability) of two ultra-short course TPT strategies, in the context of recent diagnosis and treatment for cryptococcal meningitis. We will enrol 205 adults with HIV-associated cryptococcal meningitis from three hospitals in Uganda. Participants will be randomised to either inpatient initiation (early) or outpatient initiation (standard, week 6) of 1HP (one month of isoniazid and rifapentine). Participant follow-up is to include TB screening, 1HP pill counts and tolerability reviews on alternate weeks until week-18. The trial primary endpoint is TB-disease free 1HP treatment completion at 18-weeks, secondary endpoints: 1HP treatment completion, 1HP discontinuation, grade ≥3 adverse events and serious adverse events, drug-induced liver injury, incident active TB, 18-week survival; rifapentine, fluconazole and dolutegravir concentrations will be measured with intensive sampling in a pharmacokinetic sub-study of 15 eligible participants. The IMPROVE trial will provide preliminary safety and feasibility data to inform 1HP TPT strategies for adults with advanced HIV disease and cryptococcal meningitis. The potential impact of demonstrating that inpatient initiation of 1HP TPT is safe and feasible amongst this high-risk subpopulation with advanced HIV disease, would be to expand the range of clinical encounters in which clinicians can feasibly provide 1HP, and therefore increase the reach of TPT as a preventative intervention. ISRCTN18437550 (05/11/2021).

Potent anti-biofilm properties of plumbagin against fluconazole-resistant Candida auris

Background and aimThe escalation of fungal infections is driving an increase in disease and mortality rates. In particular, the emergence of Candida auris (C. auris), which shows powerful resistance to the antifungal drug fluconazole, is becoming a global concern. Furthermore, several biological hurdles need to be overcome by candidate therapeutics because C. auris has the ability to form biofilm. Therefore, this study aimed to investigate the antifungal and anti-biofilm effects of plumbagin, a natural extract, against fluconazole-resistant C. auris (FRCA). Experimental procedureThe minimum inhibitory concentrations (MICs) of fluconazole and plumbagin were determined against clinically isolated C. auris. Inhibition of biofilm formation and eradication effects of plumbagin against FRCA were confirmed through minimum biofilm inhibition concentration (MBIC) and minimum biofilm eradication concentration (MBEC) assays. Additionally, the inhibition of metabolic activity in biofilm cells was verified through quantification by XTT reduction assay and visualization by confocal laser scanning microscopy (CLSM). The relative expression levels of the azole resistant gene ERG11, the efflux pump gene CDR1, and the extracellular matrix gene KRE6, were measured. Results and conclusionPlumbagin exhibits antifungal efficacy against C. auris and has been shown to effectively inhibit both the formation and eradication of biofilms produced by FRCA. Furthermore, the metabolic activity inhibition in biofilm cells was both quantified and visually observed. The downregulation of all genes (ERG11, CDR1, and KRE6) by plumbagin was confirmed. Taken together, this study demonstrates that plumbagin has antifungal and anti-biofilm efficacy against FRCA, indicating its potential as an alternative to antifungal agents and a valuable resource in combating FRCA infections.

Distribution of antibiotic resistance genes and antibiotic residues in drinking water production facilities: Links to bacterial community.

There is a rapid spread of antibiotic resistance in the environment. However, the impact of antibiotic resistance in drinking water is relatively underexplored. Thus, this study aimed to quantify antibiotic resistance genes (ARGs) and antibiotic residues in two drinking water production facilities (NW-E and NW-C) in North West Province, South Africa and link these parameters to bacterial communities. Physicochemical and ARG levels were determined using standard procedures. Residues (antibiotics and fluconazole) and ARGs were quantified using ultra-high performance liquid chromatography (UHPLC) chemical analysis and real-time PCR, respectively. Bacterial community compositions were determined by high-throughput 16S rRNA sequencing. Data were analysed using redundancy analysis and pairwise correlation. Although some physicochemical levels were higher in treated than in raw water, drinking water in NW-E and NW-C was safe for human consumption using the South African Water Quality Guideline (SAWQG). ARGs were detected in raw and treated water. In NW-E, the concentrations of ARGs (sul1, intl1, EBC, FOX, ACC and DHA) were higher in treated water than in raw water. Regarding antimicrobial agents, antibiotic and fluconazole concentrations were higher in raw than in treated water. However, in NW-C, trimethoprim concentrations were higher in raw than in treated water. Redundancy analysis showed that bacterial communities were not significantly correlated (Monte Carlo simulations, p-value >0.05) with environmental factors. However, pairwise correlation showed significant differences (p-value <0.05) for Armatimonas, CL500-29 marine group, Clade III, Dickeya and Zymomonas genera with environmental factors. The presence of ARGs and antibiotic residues in the current study indicated that antibiotic resistance is not only a clinical phenomenon but also in environmental settings, particularly in drinking water niches. Consumption of NW-E and NW-C treated water may facilitate the spread of antibiotic resistance among consumers. Thus, regulating and monitoring ARGs and antibiotic residues in drinking water production facilities should be regarded as paramount.

Unraveling multi-template molecularly imprinted polymer for selective extraction of triazole antifungals: Theoretical and experimental investigation

Fungal coinfection is an emerging problem in the COVID-19 pandemic. Aspergillus and Candida species are the most prevalent pathogens. Therapeutic drug monitoring of triazole antifungals as a first-line therapy is required to increase their effectiveness and minimize toxicity. Bioanalysis of triazole antifungals requires selective extraction because of the complexity of matrices. Molecularly imprinted polymers (MIP) are potential solutions for increasing selectivity. This study aimed to synthesize a selective MIP sorbent to simultaneously determine voriconazole, itraconazole, and fluconazole concentrations through computational and laboratory studies. The host-guest interaction was used in the selection of monomer and solvent. The synthesis was optimized by precipitation and bulk methods using single and multi-template. Adsorption tests, characterizations, and application to the sample were performed to analyze the MIP performance. The optimal synthesis obtained using the precipitation method with mol ratio of template:monomer:crosslinker was 1:4:20. Adsorption equilibrium was established within 3 h and following pseudo-second-order kinetic. The MIP-P9 provided the highest adsorption capacity and followed the Freundlich isotherm. Characterization of MIP confirmed the successful synthesis and template removal of MIP. MIP was selective to triazole antifungals and had higher recovery than NIP and SPE C18. Based on these findings, MIP can be utilized for direct separation in clinical analysis.

Embryotoxicity of fluconazole on developing chick embryos

Abstract Background Fluconazole is a first-generation triazole used as an antifungal treatment for skin, hair, and nail infections. The study aimed to assess the embryotoxicity and teratological effects of fluconazole on chick embryos. Fertilized eggs were divided into four groups: two experimental groups treated with different concentrations of fluconazole (0.1 ml/egg, 0.2 ml/egg) containing 12 and 11 eggs, respectively, one group treated with distilled water (10 eggs), and a control group (10 eggs) left untreated. The liquid form of fluconazole was administered on the 4th day of incubation, and observations were made on the 9th day. Results There were different anomalies observed in them like hydrocephaly, microcephaly shorting of the beak, agenesis, Amelia, micromelia, anophthalmia, microphthalmia, and kyphosis. There were also observed the morphometric measurements with a difference of significant (p &lt; 0.001) and (p &lt; 0.01) in CR length, body weight, head circumference, eye circumference, forelimb, and hind limb. Different vital organ defects were also observed in histological studies. Fluconazole in various combinations has been found to cause embryotoxicity and teratological consequences in chick embryos. Conclusion The current study showed that fluconazole is teratogenic in creating chick undeveloped organisms. The embryotoxic impacts were recorded on structural morphometric and graphic levels.

A ketogenic diet enhances fluconazole efficacy in murine models of systemic fungal infection.

Invasive fungal infections are a significant public health concern, with mortality rates ranging from 20% to 85% despite current treatments. Therefore, we examined whether a ketogenic diet could serve as a successful treatment intervention in murine models of Cryptococcus neoformans and Candida albicans infection in combination with fluconazole-a low-cost, readily available antifungal therapy. The ketogenic diet is a high-fat, low-carbohydrate diet that promotes fatty acid oxidation as an alternative to glycolysis through the production of ketone bodies. In this series of experiments, mice fed a ketogenic diet prior to infection with C. neoformans and treated with fluconazole had a significant decrease in fungal burden in both the brain (mean 2.66 ± 0.289 log10 reduction) and lung (mean 1.72 ± 0.399 log10 reduction) compared to fluconazole treatment on a conventional diet. During C. albicans infection, kidney fungal burden of mice in the keto-fluconazole combination group was significantly decreased compared to fluconazole alone (2.37 ± 0.770 log10-reduction). Along with higher concentrations of fluconazole in the plasma and brain tissue, fluconazole efficacy was maximized at a significantly lower concentration on a keto diet compared to a conventional diet, indicating a dramatic effect on fluconazole pharmacodynamics. Our findings indicate that a ketogenic diet potentiates the effect of fluconazole at multiple body sites during both C. neoformans and C. albicans infection and could have practical and promising treatment implications.IMPORTANCEInvasive fungal infections cause over 2.5 million deaths per year around the world. Treatments for fungal infections are limited, and there is a significant need to develop strategies to enhance antifungal efficacy, combat antifungal resistance, and mitigate treatment side effects. We determined that a high-fat, low-carbohydrate ketogenic diet significantly potentiated the therapeutic effect of fluconazole, which resulted in a substantial decrease in tissue fungal burden of both C. neoformans and C. albicans in experimental animal models. We believe this work is the first of its kind to demonstrate that diet can dramatically influence the treatment of fungal infections. These results highlight a novel strategy of antifungal drug enhancement and emphasize the need for future investigation into dietary effects on antifungal drug activity.

Resazurin to determine the minimum inhibitory concentration on antifungal susceptibility assays for Fonsecaea sp. using a modified EUCAST protocol.

Chromoblastomycosis is a fungal chronic disease, which affects humans, especially in cutaneous and subcutaneous tissues. There is no standard treatment for Chromoblastomycosis, and it is a therapeutic challenge, due natural resistance of their causative agents, inadequate response of patients and common cases of relapse. Protocols for determination of antifungal drugs susceptibility are not standardized for chromoblastomycosis agents and endpoint definition is usually based on visual inspection, which depends on the analyst, making it sometimes inaccurate. We presented a colorimetric and quantitative methodology based on resazurin reduction to resofurin to determine the metabolic status of viable cells of Fonsecaea sp. Performing antifungal susceptibility assay by a modified EUCAST protocol allied to resazurin, we validated the method to identify the minimum inhibitory concentrations of itraconazole, fluconazole, amphotericin B, and terbinafine for eight Fonsecaea clinical isolates. According to our data, resazurin is a good indicator of metabolic status of viable cells, including those exposed to antifungal drugs. This work aimed to test resazurin as an indicator of the metabolic activity of Fonsecaea species in susceptibility assays to antifungal drugs. Species of this genus are the main causative agents of Chromoblastomycosis, which affects humans.

Integrated management of cryptococcal meningitis and concurrent opportunistic infections to improve outcomes in advanced HIV disease: a randomised strategy trial

Background: Mortality associated with HIV-associated cryptococcal meningitis remains high even in the context of clinical trials (24–45% at 10 weeks); mortality at 12-months is up to 78% in resource limited settings. Co-prevalent tuberculosis (TB) is common and preventable, and likely contributes to poor patient outcomes. Innovative strategies to increase TB preventative therapy (TPT) provision and uptake within this high-risk group are needed. Protocol: The IMPROVE trial is a nested open label, two arm, randomised controlled strategy trial to evaluate the safety (adverse events) and feasibility (adherence and tolerability) of two ultra-short course TPT strategies, in the context of recent diagnosis and treatment for cryptococcal meningitis. We will enrol 205 adults with HIV-associated cryptococcal meningitis from three hospitals in Uganda. Participants will be randomised to either inpatient initiation (early, week 2) or outpatient initiation (standard, week 6) of 1HP (one month of isoniazid and rifapentine). Participant follow-up is to include TB screening, pill counts and tolerability reviews on alternate weeks until week-18. The trial primary endpoint is TB-disease free 1HP treatment completion at 18-weeks, secondary endpoints: 1HP treatment completion, 1HP discontinuation, grade ≥3 adverse events and serious adverse events, drug-induced liver injury, incident active TB, 18-week survival; rifapentine, fluconazole and dolutegravir concentrations will be measured in a drug-drug interaction sub-study of 15 eligible participants. Discussion: The IMPROVE trial will provide preliminary safety and feasibility data to inform 1HP TPT strategies for adults with advanced HIV disease and cryptococcal meningitis. The potential impact of demonstrating that inpatient initiation of 1HP TPT is safe and feasible amongst this high-risk subpopulation with advanced HIV disease, would be to expand the range of clinical encounters in which clinicians can feasibly provide 1HP, and therefore increase the reach of TPT as a preventative intervention. ISRCTN registration: ISRCTN18437550 (05/11/2021)

Evaluation of antifungal activity of natural compounds on growth and aflatoxin B1 production of Aspergillus parasiticus and Aspergillus flavus.

Aspergillus species cause broad spectrum infections especially invasive lethal infections in immunocompromised patients. This study aimed to assess the antifungal activity of plants and compounds including Aloe vera, Thyme, carvacrol, and nano-encapsulation of carvacrol on the growth and production of aflatoxin B1 production by Aspergillus parasiticus and Aspergillus flavus. Minimum inhibitory concentrations of extracts Aloe vera, Thyme, carvacrol, and nanocarvacrol, and fluconazole as a control were determined according to Clinical and Laboratory Standards Institute by serial microdilution protocol. Then, the effect of inhibitory concentrations of these compounds on the aflatoxin B1 production level was evaluated by real-time PCR and high-performance liquid chromatography. Our results indicate that the Aspergillus parasiticus and Aspergillus flavusare sensitive to selected plants and compounds. Our findings showed that the compounds are appropriate alternative candidates against growth and production of aflatoxin of Aspergillus spp.

Parallel evolution of fluconazole resistance and tolerance in Candida glabrata.

With the growing population of immunocompromised individuals, opportunistic fungal pathogens pose a global health threat. Candida species, particularly C. albicans and non-albicans Candida species such as C. glabrata, are the most prevalent pathogenic fungi. Azoles, especially fluconazole, are widely used therapeutic options. This study investigates how C. glabrata adapts to fluconazole, with a focus on understanding the factors regulating fluconazole tolerance and its relationship to resistance. This study compared the factors regulating fluconazole tolerance between C. albicans and C. glabrata. We analyzed the impact of temperature on fluconazole tolerance, and requirement of calcineurin and Hsp90 for maintenance of fluconazole tolerance. We isolated colonies from edge, inside and outside of inhibition zone in disk diffusion assays. And we exposed C. glabrata strain to high concentrations of fluconazole and investigated the mutants for development of fluconazole resistance and tolerance. We found temperature modulated tolerance in the opposite way in C.albicans strain YJB-T1891 and C. glabrata strain CG4. Calcineurin and Hsp90 were required for maintenance of fluconazole tolerance in both species. Colonies from inside and outside of inhibition zones did not exhibited mutated phenotype, but colonies isolated from edge of inhibition zone exhibited diverse phenotype changes. Moreover, we discovered that high concentrations (16-128 μg/mL) of fluconazole induce the simultaneous but parallel development of tolerance and resistance in C. glabrata, unlike the sole development of tolerance in C. albicans. This study highlights that while tolerance to fluconazole is a common response in Candida species, the specific molecular mechanisms and evolutionary pathways that lead to this response vary between species. Our findings emphasize the importance of understanding the regulation of fluconazole tolerance in different Candida species to develop effective therapeutic strategies.

Antifungal Drug Susceptibility Profile of Candida kefyr Isolated from Clinical Samples and Dairy Products.

Exploring drug susceptibility is a critical endeavor in the scientific community, setting the stage for advancements in understanding and combating various pathogens. Candida kefyr has emerged as a significant pathogen, particularly affecting immunocompromised individuals with hematologic malignancies and HIV/AIDS conditions. This study aimed to assess the antifungal susceptibility profile of Candida kefyr isolates obtained from clinical samples and dairy products. A total of 134 Candida kefyr yeast isolates were retrieved from three distinct groups: (1) healthy individuals (n = 41), (2) patients (n = 24) including hematologic malignancy (n = 9), HIV/AIDS (n = 7), and diabetes (n = 8), (3) dairy products (milk, yogurt, and cheese, n = 69) stored at -70°C in the Shiraz University of Medical Science. All Candida kefyr isolates were previously identified using conventional and molecular methods. Susceptibility to antifungal drugs, including caspofungin, fluconazole, itraconazole, voriconazole, and amphotericin B, was determined using the microdilution method following CLSI-M27-A3 protocols, with results interpreted according to CLSI-M27-S4 guidelines. The study emphasizes the clear variation in antifungal susceptibility testing of Candida kefyr strains when compared across different groups, including patients, healthy people, and dairy products. According to the results, across all groups, a high minimum inhibitory concentration of fluconazole is evident, and healthy individuals show the highest minimum inhibitory concentration geometric means (4.0681). Also, 79.1% of the isolates were wild type to amphotericin B, with the lowest minimum inhibitory concentration compared to other antifungals tested. This suggests that amphotericin B was more effective against Candida kefyr. These findings showed fewer susceptibilities of Candida kefyr to both triazole and echinocandin classes of antifungal agents. Additionally, it is noteworthy that individuals without medical conditions exhibited higher minimum inhibitory concentration rates to these antifungal agents in comparison to those with underlying health conditions. Consequently, timely diagnosis and appropriate therapeutic interventions emerge as imperative in the effective management of candidiasis cases.

Synergistic Antifungal Bioassay of Neem Leaves Extract with Essential Oils against Dermatophytes

Introduction: The neem plant is also known as a panacea in dentistry due to its antimicrobial properties and plays vital role in the cosmetic industry as it is extensively used in cosmetic preparations for hair and skin care. Objective: The present study was carried out to evaluate the synergistic activity of essential oils in combination with neem leaves ethanolic extracts. Methods: The antifungal activity of neem leaves (Azadirachta indica) ethanolic extracts in combination with A. indica, Eucalyptus citriodora and Cymbopogon martini essential oils was conducted by agar well diffusion method followed by M38-A2 broth microdilution method on pathogenic dermatophytes strains; Microsporum gypseum, Trichophyton mentagrophytes and T. rubrum. Neem leaves extract was obtained by treating the matured green leaves with ethanol. Moreover, HPLC analysis was performed to narrate the terpenoid content having extensively noted antifungal spectrum. The potent antimycotic fluconazole taken as a positive control. Result: The result exhibited that there was overall growth retardation of the dermatophytes at minimum inhibitory concentration between 125 to 250 μg/mL for leaves extract and between 0.078 to 5.0 μL for selected essential oils. The range of minimum inhibitory concentration (MIC) of fluconazole was found between 0.25 and 0.50 μg/mL. Conclusion: Neem leaves ethanolic extracts analysis showed the possible existence of terpenoids in extracts that are recognized having extensive biological action. The outcomes of this study showed a novel report on the therapeutic potential of neem leaves extract with A. indica, E. citriodora and C. martini to control dermatophytosis. The neem leaf extract and antifungal herbal oil in combination have been proven to improve and broad-spectrum antifungal activity and they can be formulated in suitable formulations for the effective treatment of mycosis.

High-Throughput Monitoring of Pathogenic Fungal Growth Using Whole Slide Imaging for Rapid Antifungal Susceptibility Assessment

Invasive fungal infections are a major health threat with high morbidity and mortality, highlighting the urgent need for rapid diagnostic tools to detect antifungal resistance. Traditional culture-based antifungal susceptibility testing (AFST) methods often fall short due to their lengthy process. In our previous research, we developed a whole-slide imaging (WSI) technique for the high-throughput assessment of bacterial antibiotic resistance. Building on this foundation, this study expands the application of WSI by adapting it for rapid AFST through high-throughput monitoring of the growth of hundreds of individual fungi. Due to the distinct “budding” growth patterns of fungi, we developed a unique approach that utilizes specific cell number change to determine fungi replication, instead of cell area change used for bacteria in our previous study, to accurately determine the growth rates of individual fungal cells. This method not only accelerates the determination of antifungal resistance by directly observing individual fungal cell growth, but also yields accurate results. Employing Candida albicans as a representative model organism, reliable minimum inhibitory concentration (MIC) of fluconazole inhibiting 100% cells of Candida albicans (denoted as MIC100) was obtained within 3h using the developed method, while the modified broth dilution method required 72h for the similar reliable result. In addition, our approach was effectively utilized to test blood culture samples directly, eliminating the need to separate the fungi from whole blood samples spiked with Candida albicans. These features indicate the developed method holds great potential serving as a general tool in rapid antifungal susceptibility testing and MIC determination.

Synergistic potential of teriflunomide with fluconazole against resistant Candida albicans in vitro and in vivo.

Candida albicans is the primary cause of systemic candidiasis, which is involved in high morbidity and mortality. Drug resistance exacerbates these problems. In addition, there are limited antifungal drugs available. In order to solve these problems, combination therapy has aroused great interest. Teriflunomide is an immunosuppressant. In the present work, we aimed to identify whether teriflunomide can reverse the resistance of Candida albicans in the presence of sub-inhibitory concentrations of fluconazole in vitro and in vivo. Seven Candida albicans isolates were used in this study. Susceptibility of Candida albicans in vitro to the drugs was determined using a checkerboard microdilution assay in accordance with the recommendations of the Clinical and Laboratory Standards Institute. The effects of drugs on biofilm biomass of Candida albicans were determined by crystal violet staining. The development ability of Candida albicans hyphae was performed using a modified broth microdilution method. Galleria mellonella was used for testing the in vivo efficacy of the combination therapies. We found that the combination of teriflunomide (64 µg/mL) and fluconazole (0.5-1 µg/mL) has a significant synergistic effect in all resistant Candida albicans isolates (n=4). Also, this drug combination could inhibit the immature biofilm biomass and hyphae formation of resistant Candida albicans. Galleria mellonella was used for testing the in vivo efficacy of this combination therapies. As for the Galleria mellonella larvae infected by resistant Candida albicans, teriflunomide (1.6 µg/larvae) combined with fluconazole (1.6 µg/larvae) significantly increased their survival rates, and reduced the fungal burden, as well as damage of tissue in comparison to that in the control group or drug monotherapy group. These results expand our knowledge about the antifungal potential of teriflunomide as an adjuvant of existing antifungal drugs, and also open new perspectives in the treatment of resistant Candida albicans based on repurposing clinically available nonantifungal drugs.

Invitro Antifungal Activity of Ziziphusmauritiana Extraction Against Clinical Isolates of Candida Spp at Khartoum State, 2021

experimental biomedical study was carried out at Omdurman Maternal Hospital, Saudi Maternal Hospital and AlzaiemAlazhari University during the period from September to December 2021. 30 Candida species, of them 17 isolated from urine samples and 13 from vaginal swabs were included in this study. Antifungal activity was performed usingcup plate method using different concentrations of plant extraction (100%, 50% and 25%) and fluconazole(10μg). The statistical analysis was performed using SPSS version 20. Results: the results showed significant increase in antifungal activity with increase in Ziziphusmauritianaconcentration, while fluconazole showed best antifungal activity.However, the fungicidal concentration showed that Ziziphusmauritiana methanol extracts was able to inhibit Candia SPPs rather than C. albicans.