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Candida albicans is one of the agents of invasive candidiasis, a life-threatening disease strongly associated with hospitalization, particularly among patients in intensive care units with central venous catheters. This study aimed to evaluate the synergistic activity of the antifungal peptide ToAP2 combined with fluconazole against C. albicans biofilms grown on various materials. We tested combinations of different concentrations of the peptide ToAP2 with fluconazole on C. albicans biofilms. These biofilms were generated on 96-well plates, intravenous catheters, and infusion tubes in RPMI medium at two maturation stages. Scanning electron microscopy and atomic force microscopy were employed to assess the biofilm structure. We also evaluated the expression of genes previously proven to be involved in C. albicans biofilm formation in planktonic and biofilm cells after treatment with the peptide ToAP2 using qPCR. ToAP2 demonstrated a synergistic effect with fluconazole at concentrations up to 25 µM during both the early and mature stages of biofilm formation in 96-well plates and on medical devices. Combinations of 50, 25, and 12.5 µM of ToAP2 with 52 µM of fluconazole significantly reduced the biofilm viability compared to individual treatments and untreated controls. These results were supported by substantial structural changes in the biofilms observed through both scanning and atomic force microscopy. The gene expression analysis of C. albicans cells treated with 25 µM of ToAP2 revealed a decrease in the expression of genes associated with membrane synthesis, along with an increase in the expression of genes involved in efflux pumps, adhesins, and filamentation. Our results highlight the efficacy of the combined ToAP2 and fluconazole treatment against C. albicans biofilms. This combination not only shows therapeutic potential but also suggests its utility in developing preventive biofilm tools for intravenous catheters.
Assuntos
Antifúngicos , Biofilmes , Candida albicans , Sinergismo Farmacológico , Fluconazol , Biofilmes/efeitos dos fármacos , Biofilmes/crescimento & desenvolvimento , Fluconazol/farmacologia , Candida albicans/efeitos dos fármacos , Candida albicans/fisiologia , Antifúngicos/farmacologia , Peptídeos Antimicrobianos/farmacologia , Testes de Sensibilidade Microbiana , Humanos , Microscopia de Força Atômica , Regulação Fúngica da Expressão Gênica/efeitos dos fármacos , Proteínas Fúngicas/genética , Proteínas Fúngicas/metabolismoRESUMO
INTRODUCTION: The study of Candida glabrata genes associated with fluconazole resistance, from a molecular perspective, increases the understanding of the phenomenon with a view to its clinical applicability. OBJECTIVE: We sought to establish the predictive molecular profile of fluconazole resistance in Candida glabrata by analyzing the ERG11, ERG3, CgCDR1, and CgSNQ2 genes. METHOD: Expression was quantified using RT-qPCR. Metrics were obtained through molecular docking and Fisher discriminant functions. Additionally, a predictive classification was made against the susceptibility of C. glabrata to fluconazole. RESULTS: The relative expression of the ERG3, CgCDR1, and CgSNQ2 genes was higher in the fluconazole-resistant strains than in the fluconazole-susceptible, dose-dependent strains. The gene with the highest relative expression in the fluconazole-exposed strains was CgCDR1, and in both the resistant and susceptible, dose-dependent strains exposed to fluconazole, this was also the case. The molecular docking model generated a median number of contacts between fluconazole and ERG11 that was lower than the median number of contacts between fluconazole and ERG3, -CgCDR1, and -CgSNQ2. The predicted classification through the multivariate model for fluconazole susceptibility achieved an accuracy of 73.5%. CONCLUSION: The resistant strains had significant expression levels of genes encoding efflux pumps and the ERG3 gene. Molecular analysis makes the identification of a low affinity between fluconazole and its pharmacological target possible, which may explain the lower intrinsic susceptibility of the fungus to fluconazole.
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Vulvovaginal candidiasis (VVC) is an opportunistic infection caused by a fungus of the Candida genus, affecting approximately 75 % of women during their lifetime. Fungal resistance cases and adverse effects have been the main challenges of oral therapies. In this study, the topical application of thin films containing fluconazole (FLU) and thymol (THY) was proposed to overcome these problems. Vaginal films based only on chitosan (CH) or combining this biopolymer with pectin (PEC) or hydroxypropylmethylcellulose acetate succinate (HPMCAS) were developed by the solvent casting method. In addition to a higher swelling index, CH/HPMCAS films showed to be more plastic and flexible than systems prepared with CH/PEC or only chitosan. Biopolymers and FLU were found in an amorphous state, contributing to explaining the rapid gel formation after contact with vaginal fluid. High permeability rates of FLU were also found after its immobilization into thin films. The presence of THY in polymer films increased the distribution of FLU in vaginal tissues and resulted in improved anti-Candida activity. A significant activity against the resistant C. glabrata was achieved, reducing the required FLU dose by 50 %. These results suggest that the developed polymer films represent a promising alternative for the treatment of resistant vulvovaginal candidiasis, encouraging further studies in this context.
Assuntos
Antifúngicos , Candidíase Vulvovaginal , Fluconazol , Timol , Feminino , Candidíase Vulvovaginal/tratamento farmacológico , Candidíase Vulvovaginal/microbiologia , Fluconazol/farmacologia , Fluconazol/química , Fluconazol/administração & dosagem , Antifúngicos/farmacologia , Antifúngicos/química , Antifúngicos/administração & dosagem , Biopolímeros/química , Timol/química , Timol/farmacologia , Farmacorresistência Fúngica/efeitos dos fármacos , Humanos , Quitosana/química , Testes de Sensibilidade Microbiana , Animais , Portadores de Fármacos/química , Permeabilidade , Candida glabrata/efeitos dos fármacosRESUMO
While fluconazole use is generally considered safe and well-tolerated, there has been an increasing number of reports regarding several adverse events. Therefore, the present study aimed to present a unique case in which photobiomodulation therapy (PBMT) was employed to manage bullous erythema multiforme lesions secondary to fluconazole intake. A 32-year-old female patient sought emergency dental care due to painful orofacial lesions that had developed two days after oral fluconazole use for recurrent vulvovaginal candidiasis. Given the acute clinical features, a diagnosis of bullous erythema multiforme secondary to fluconazole was established. Prednisone 20 mg was then prescribed for five days, and fluconazole intake was immediately discontinued. As the initial treatment strategies failed to show improvement in the clinical condition, three PBMT sessions were proposed every other day. Within seven days, almost complete wound healing was observed, and any pain complaints were no longer present. The resolution of orofacial lesions within a short period suggests that PBMT could be a promising tool for managing drug-induced bullous erythema multiforme. However, more studies are needed to confirm this statement.
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As the prevalence of drug-resistant Candida isolates continues to rise, the imperative for identifying novel compounds to enhance the arsenal of antifungal drugs becomes increasingly critical. Consequently, exploring new treatment strategies, including synthesizing molecular hybrids and applying combination therapy, is essential. For this reason, this study evaluated the efficacy of ten molecular hybrids of aza-bicyclic 2-isoxazoline-acylhydrazone belonging to two series 90 and 91 as possible anti-Candida agents. In addition, we also investigated the interaction between the hybrids and fluconazole, a commonly used antifungal drug. We evaluated the antifungal effect of aza-bicyclic 2-isoxazoline-acylhydrazone hybrid compounds against six Candida spp. strains that target planktonic cells. However, none of these new molecules were inhibitory active at the tested concentrations (2 to 1,024 µg/mL). Moreover, we analyzed the interaction between the ten new hybrid molecules and fluconazole using the checkerboard assay, employing two different methodologies for reading the plate. For this, one isolate fluconazole-resistant was selected. We observed that only one combination, 6-(4-tert-butylbenzoil)-4,5,6,6a-tetrahydro-3a-H-pirrole[3,2-d]isoxazole-3-carboxylic(furan-2-metilidene)-hydrazide (91e) and fluconazole, exhibited a synergistic interaction (FICI range 0.0781 to 0.4739). The combination successfully inhibited the growth of C. albicans CA2 fluconazole-resistant, and no interaction was observed in an isolate susceptible to fluconazole. Additionally, these results emphasize the continued need for research into new compounds and the importance of using combined approaches to increase their activity.
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Antifúngicos , Candida albicans , Farmacorresistência Fúngica , Sinergismo Farmacológico , Fluconazol , Hidrazonas , Isoxazóis , Testes de Sensibilidade Microbiana , Antifúngicos/farmacologia , Antifúngicos/química , Fluconazol/farmacologia , Candida albicans/efeitos dos fármacos , Hidrazonas/farmacologia , Hidrazonas/química , Isoxazóis/farmacologia , Isoxazóis/química , HumanosRESUMO
Trichosporon spp. is an emerging opportunistic pathogen and a common cause of both superficial and invasive infections. Although Trichosporon asahii is the most frequently isolated species, Trichosporon cutaneum is also widely observed, as it is the predominant agent in cases of white Piedra and onychomycosis. Trichosporon spp. is a known to produce biofilms, which serve as one of its virulence mechanisms, however, there is limited data available on biofilms formed by T. cutaneum. Thus, the aim of this study was to assess the adhesion and biofilm formation of two clinical isolates of T. cutaneum under various environmental conditions (including temperature, nutrient availability, and carbon source), as well as their tolerance to fluconazole. Adhesion was tested on common abiotic substrates (such as silicone, glass, and stainless steel), revealing that T. cutaneum readily adhered to all surfaces tested. CV staining was applied for the evaluation of the environment influence on biofilm efficiency and it was proved that the nutrient availability has a major impact. Additionaly, fluorescent staining was employed to visualize the morphology of T. cutaneum biofilm and its survival in the presence of fluconazole. Hyphae production was shown to play a role in elevated biofilm production in minimal medium and increased tolerance to fluconazole.
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Biofilmes , Trichosporon , Biofilmes/crescimento & desenvolvimento , Trichosporon/fisiologia , Trichosporon/isolamento & purificação , Trichosporon/efeitos dos fármacos , Humanos , Tricosporonose/microbiologia , Antifúngicos/farmacologia , Fluconazol/farmacologiaRESUMO
Antifungal therapy, especially with the azoles, could promote the incidence of less susceptible isolates of Cryptococcus neoformans and C. gattii species complexes (SC), mostly in developing countries. Given that these species affect mostly the immunocompromised host, the infections are severe and difficult to treat. This review encompasses the following topics: 1. infecting species and their virulence, 2. treatment, 3. antifungal susceptibility methods and available categorical endpoints, 4. genetic mechanisms of resistance, 5. clinical resistance, 6. fluconazole minimal inhibitory concentrations (MICs), clinical outcome, 7. environmental influences, and 8. the relevance of host factors, including pharmacokinetic/pharmacodynamic (PK/PD) parameters, in predicting the clinical outcome to therapy. As of now, epidemiologic cutoff endpoints (ECVs/ECOFFs) are the most reliable antifungal resistance detectors for these species, as only one clinical breakpoint (amphotericin B and C. neoformans VNI) is available.
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AIM: This study aims to incorporate alginate microparticles containing berberine and fluconazole into two different types of pharmaceutical formulations, to subsequently evaluate the antifungal activity against Candida albicans. METHODS AND RESULTS: Alginate microparticles containing BBR (berberine) and FLU (fluconazole) were produced by the spray-drying technique, characterized and incorporated in two pharmaceutical formulations, a vaginal cream and artificial saliva. Broth microdilution, checkerboard, time-kill curve, and scanning electron microscopy were carried out to determine the antifungal effects of BBR and FLU against C. albicans. The minimum inhibitory concentration (MIC) and minimum fungicidal concentration (MFC) values of free BBR were 125 µg ml-1. Synergism between BBR and FLU was demonstrated by a fractional inhibitory concentration index (FICI) = 0.0762. The time-kill curve for the combination BBR + FLU showed a more pronounced decrease in fungal growth in comparison to free drugs, and an antibiofilm effect of BBR occurred in the formation and preformed biofilm. CONCLUSION: Alginate microparticles containing BBR and FLU were obtained and incorporated in a vaginal cream and artificial saliva. Both formulations showed good stability, antifungal effects, and organoleptic characteristics, which suggest that BBR-FLU microparticles in formulations have potential as antifungal therapy.
Assuntos
Berberina , Candidíase , Humanos , Feminino , Fluconazol/farmacologia , Antifúngicos/farmacologia , Antifúngicos/uso terapêutico , Berberina/farmacologia , Saliva Artificial/farmacologia , Saliva Artificial/uso terapêutico , Cremes, Espumas e Géis Vaginais/farmacologia , Cremes, Espumas e Géis Vaginais/uso terapêutico , Candidíase/microbiologia , Candida albicans , Testes de Sensibilidade Microbiana , Alginatos/farmacologia , Sinergismo Farmacológico , Farmacorresistência FúngicaRESUMO
Resumen Los abscesos renales son una complicación poco frecuente de las infecciones del tracto urinario y suelen asociarse con un aumento de la morbi-mortalidad. La mayoría de los casos ocurre en pacientes con factores predisponentes como la inmunosupresión. El diagnóstico requiere de una elevada sospecha clínica y el trata miento consiste en el uso de antibióticos y antifúngicos parenterales asociados o no a intervenciones quirúrgicas como nefrostomía y nefrectomía. Son pocos los casos publicados en la literatura médi ca de abscesos renales bilaterales multifocales y menos aún por Candida albicans. Se presenta el caso de una mujer de 20 años de edad con diabetes mellitus tipo 1 diagnosticada a los 8 años, múltiples internaciones por cetoacidosis diabética y reciente internación por can didemia (Candida albicans) completando tratamiento con fluconazol por 23 días. A los 18 días de su externación, consulta por dolor en flancos de tipo sordo y síntomas ge nerales; se realizó tomografía de abdomen con contraste que mostró abscesos multifocales bilaterales. Aislándose Candida albicans en una de las muestras obtenidas de las lesiones; recibió tratamiento con fluconazol 400 mg por 6 semanas endovenoso y 2 semanas vía enteral, evolu cionando favorablemente con mejoría clínica e image nológica continuando seguimiento clínico ambulatorio. Este reporte resalta la importancia del diagnóstico y tratamiento de esta complicación infrecuente en enfer medades complejas como la diabetes.
Abstract Renal abscesses are a rare complication of urinary tract infections and may be associated with increased morbidity and mortality. Most cases occur in patients with predisposing factors such as immunosuppression. Diagnosis requires high clinical suspicion and its treat ment consists in the use of parenteral antibiotics and antifungals associated or not with surgical interventions such as nephrostomy and nephrectomy. Few cases have been published in the medical literature of multifocal bilateral renal abscesses and even fewer due to Candida albicans. We present the case of a 20-year-old woman with type 1 diabetes mellitus, diagnosed at age 8, multiple hospitalizations for diabetic ketoacidosis, and recent hospitalization for candidemia (Candida albicans) treated with fluconazole for 23 days. Eighteen days after her discharge, she consulted for dull flank pain and gen eral symptoms. Contrast enhanced abdominal tomography showed bilateral multifocal abscesses and Candida albicans was isolated in one of the samples obtained from lesions. She received fluconazole 400 mg, 6 weeks i.v. and 2 weeks via enteral route, evolving favorably with clinical and imag ing improvement, continuing outpatient clinical monitoring. This report highlights the importance of diagnosis and treatment of this rare complication in complex diseases such as diabetes mellitus.
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The increasing antifungal resistance rates against conventional drugs reveal the urgent need to search for new therapeutic alternatives. In this context, natural bioactive compounds have a critical role in antifungal drug development. Since evidence demonstrates that abietic acid, a diterpene found in Pinus species, has significant antimicrobial properties, this study aimed to evaluate the antifungal activity of abietic acid against Candida spp and its ability to potentiate the activity of fluconazole. Abietic acid was tested both individually and in combination with fluconazole against Candida albicans (CA INCQS 40006), Candida krusei (CK INCQS 40095), and Candida tropicalis (CT INCQS 40042). The microdilution method was used to determine the IC50 and the cell viability curve. Minimum Fungicidal Concentration (MFC) was determined by subculture in a solid medium. The plasma membrane permeability was measured using a fluorescent SYTOX Green probe. While the IC50 of the drugs alone ranged between 1065 and 3255 µg/mL, the IC50 resulting from the combination of abietic acid and fluconazole ranged between 7563 and 160.1 µg/mL. Whether used in combination with fluconazole or isolated, abietic acid exhibited Minimum Fungicidal Concentration (MFC) values exceeding 1024 µg/mL against Candida albicans, Candida krusei and Candida tropicalis. However, it was observed that the antifungal effect of fluconazole was enhanced when used in combination with abietic acid against Candida albicans and Candida tropicalis. These findings suggest that while abietic acid alone has limited inherent antifungal activity, it can enhance the effectiveness of fluconazole, thereby reducing antifungal resistance.