RESUMEN

Cladosporium cladosporioides are the pigmented soil fungi containing melanin. The aim of this work was to determine the influence of amphotericin B on free radicals in the natural melanin isolated from pigmented fungi Cladosporium cladosporioides and to compare it with the effect in synthetic DOPA-melanin. Electron paramagnetic resonance (EPR) spectra were measured at X-band (9.3 GHz) with microwave power in the range of 2.2-70 mW. Amplitudes, integral intensities, linewidths of the EPR spectra, and g factors, were analyzed. The concentrations of free radicals in the tested melanin samples were determined. Microwave saturation of EPR lines indicates the presence of pheomelanin in addition to eumelanin in Cladosporium cladosporioides. o-Semiquinone free radicals in concentrations ~1020 [spin/g] exist in the tested melanin samples and in their complexes with amphotericin B. Changes in concentrations of free radicals in the examined synthetic and natural melanin point out their participation in the formation of amphotericin B binding to melanin. A different influence of amphotericin B on free radical concentration in Cladosporium cladosporioides melanin and in DOPA-melanin may be caused by the occurrence of pheomelanin in addition to eumelanin in Cladosporium cladosporioides. The advanced spectral analysis in the wide range of microwave powers made it possible to compare changes in the free radical systems of different melanin polymers. This study is important for knowledge about the role of free radicals in the interactions of melanin with drugs.

Asunto(s)

Anfotericina B , Cladosporium , Melaninas , Melaninas/metabolismo , Cladosporium/efectos de los fármacos , Espectroscopía de Resonancia por Spin del Electrón/métodos , Anfotericina B/farmacología , Radicales Libres/metabolismo , Dihidroxifenilalanina/química , Dihidroxifenilalanina/metabolismo , Dihidroxifenilalanina/análogos & derivados

RESUMEN

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

Asunto(s)

Anfotericina B , Antifúngicos , Candida auris , Candidiasis , Farmacorresistencia Fúngica , Pruebas de Sensibilidad Microbiana , Humanos , Anfotericina B/farmacología , Antifúngicos/farmacología , China/epidemiología , Farmacorresistencia Fúngica/genética , Candidiasis/microbiología , Candidiasis/tratamiento farmacológico , Candida auris/genética , Candida auris/efectos de los fármacos , Evolución Molecular , Masculino , Mutación , Femenino , Persona de Mediana Edad , Proteínas Fúngicas/genética

RESUMEN

Introduction. Sporotrichosis is a subcutaneous infection caused by dimorphic Sporothrix species embedded in the clinical clade. Fungi have virulence factors, such as biofilm and melanin production, which contribute to their survival and are related to the increase in the number of cases of therapeutic failure, making it necessary to search for new options.Gap statement. Proton pump inhibitors (PPIs) have already been shown to inhibit the growth and melanogenesis of other fungi.Aim. Therefore, this study aimed to evaluate the effect of the PPIs omeprazole (OMP), rabeprazole (RBP), esomeprazole, pantoprazole and lansoprazole on the susceptibility and melanogenesis of Sporothrix species, and their interactions with itraconazole, terbinafine and amphotericin B.Methodology. The antifungal activity of PPIs was evaluated using the microdilution method, and the combination of PPIs with itraconazole, terbinafine and amphotericin B was assessed using the checkerboard method. The assessment of melanogenesis inhibition was assessed using grey scale.Results. The OMP and RBP showed significant MIC results ranging from 32 to 256 µg ml-1 and 32 to 128 µg ml-1, respectively. Biofilms were sensitive, with a significant reduction (P<0.05) in metabolic activity of 52% for OMP and 50% for RBP at a concentration of 512 µg ml-1 and of biomass by 53% for OMP and 51% for RBP at concentrations of 512 µg ml-1. As for the inhibition of melanogenesis, only OMP showed inhibition, with a 54% reduction.Conclusion. It concludes that the PPIs OMP and RBP have antifungal activity in vitro against planktonic cells and biofilms of Sporothrix species and that, in addition, OMP can inhibit the melanization process in Sporothrix species.

Asunto(s)

Anfotericina B , Antifúngicos , Melanogénesis , Inhibidores de la Bomba de Protones , Sporothrix , Esporotricosis , Humanos , Anfotericina B/farmacología , Anfotericina B/uso terapéutico , Antifúngicos/farmacología , Antifúngicos/uso terapéutico , Biopelículas/efectos de los fármacos , Biopelículas/crecimiento & desarrollo , Itraconazol/farmacología , Melaninas/biosíntesis , Melaninas/metabolismo , Melanogénesis/efectos de los fármacos , Pruebas de Sensibilidad Microbiana , Inhibidores de la Bomba de Protones/farmacología , Inhibidores de la Bomba de Protones/uso terapéutico , Sporothrix/efectos de los fármacos , Sporothrix/metabolismo , Esporotricosis/tratamiento farmacológico , Esporotricosis/microbiología , Terbinafina/farmacología

RESUMEN

Leishmaniasis, attributed to the protozoan parasite Leishmania, manifests in diverse clinical forms, including cutaneous, mucocutaneous, and visceral leishmaniasis; VL constitutes a significant global health menace. Prevalent in tropical and subtropical regions, this affliction disproportionately impacts individuals below the poverty threshold, transmitted through the bite of female sandflies. Existing treatments, such as pentavalent antimony, miltefosine, and Amphotericin B, exhibit limitations. Despite the emergence of liposomal Amphotericin B (AmBisome) as a promising antileishmanial agent, its utility is impeded by adverse effects, elevated production expenses, and cytotoxicity. To address these challenges, our investigation introduces a potential remedy─a citrate-coated gold Amphotericin B nanoparticle formulation. Characterized using dynamic light scattering and transmission electron microscopy, this pioneering formulation exhibited efficacy against L. donovani Ag83 promastigotes as demonstrated by MTT cell viability testing. Evaluating internal reactive oxygen species (ROS) levels and dual staining with acridine orange and ethidium bromide unveiled its consequential impact on cell death. Significantly, our study discloses this novel nanoformulation's unprecedented inhibition of the trypanothione reductase enzyme. The findings posit the citrate-coated gold Amphotericin B nanoformulation as a promising and targeted antileishmanial agent, representing potential advancements in leishmaniasis therapeutics.

Asunto(s)

Anfotericina B , Antiprotozoarios , Oro , Nanopartículas del Metal , Oro/química , Oro/farmacología , Anfotericina B/farmacología , Anfotericina B/química , Antiprotozoarios/farmacología , Antiprotozoarios/química , Antiprotozoarios/síntesis química , Nanopartículas del Metal/química , Tamaño de la Partícula , Nanoconjugados/química , Ensayo de Materiales , Leishmania donovani/efectos de los fármacos , Materiales Biocompatibles/química , Materiales Biocompatibles/farmacología , Materiales Biocompatibles/síntesis química , Supervivencia Celular/efectos de los fármacos , Pruebas de Sensibilidad Parasitaria , Especies Reactivas de Oxígeno/metabolismo , Humanos

Asunto(s)

Anfotericina B , Antifúngicos , Candida , Farmacorresistencia Fúngica Múltiple , Sinergismo Farmacológico , Lansoprazol , Anfotericina B/farmacología , Antifúngicos/farmacología , Lansoprazol/farmacología , Humanos , Candida/efectos de los fármacos , Pruebas de Sensibilidad Microbiana , Candidiasis/microbiología , Candidiasis/tratamiento farmacológico

RESUMEN

Cryptococcosis is a fungal infection that is becoming increasingly prevalent worldwide, particularly among individuals with compromised immune systems, such as HIV patients. Amphotericin B (AmB) is the first-line treatment mainly combined with flucytosine. The scarcity and the prohibitive cost of this regimen urge the use of fluconazole as an alternative, leading to increased rates of treatment failure and relapses. Therefore, there is a critical need for efficient and cost-effective therapy to enhance the efficacy of AmB. In this study, we evaluated the efficacy of the HIV protease inhibitors (PIs) to synergize the activity of AmB in the treatment of cryptococcosis. Five PIs (ritonavir, atazanavir, saquinavir, lopinavir, and nelfinavir) were found to synergistically potentiate the killing activity of AmB against Cryptococcus strains with Æ©FICI ranging between 0.09 and 0.5 against 20 clinical isolates. This synergistic activity was further confirmed in a time-kill assay, where different AmB/PIs combinations exhibited fungicidal activity within 24 hrs. Additionally, PIs in combination with AmB exhibited an extended post-antifungal effect on treated cryptococcal cells for approximately 10 hrs compared to 4 hours with AmB alone. This promising activity against cryptococcal cells did not exhibit increased cytotoxicity towards treated kidney cells, ruling out the risk of drug combination-induced nephrotoxicity. Finally, we evaluated the efficacy of AmB/PIs combinations in the Caenorhabditis elegans model of cryptococcosis, where these combinations significantly reduced the fungal burden of the treated nematodes by approximately 2.44 Log10 CFU (92.4%) compared to the untreated worms and 1.40 Log10 ((39.4%) compared to AmB alone. The cost-effectiveness and accessibility of PIs in resource-limited geographical areas compared to other antifungal agents, such as flucytosine, make them an appealing choice for combination therapy.

Asunto(s)

Anfotericina B , Antifúngicos , Criptococosis , Sinergismo Farmacológico , Inhibidores de la Proteasa del VIH , Anfotericina B/farmacología , Anfotericina B/uso terapéutico , Antifúngicos/farmacología , Antifúngicos/uso terapéutico , Inhibidores de la Proteasa del VIH/uso terapéutico , Inhibidores de la Proteasa del VIH/farmacología , Animales , Criptococosis/tratamiento farmacológico , Humanos , Caenorhabditis elegans/microbiología , Caenorhabditis elegans/efectos de los fármacos , Pruebas de Sensibilidad Microbiana , Cryptococcus neoformans/efectos de los fármacos , Quimioterapia Combinada , Ritonavir/uso terapéutico , Ritonavir/farmacología , Cryptococcus/efectos de los fármacos

RESUMEN

As comparative pharmacokinetic/pharmacodynamic (PK/PD) studies of liposomal amphotericin B (L-AMB) against Candida spp. are lacking, we explored L-AMB pharmacodynamics against different Candida species in an in vitro PK/PD dilution model. Eight Candida glabrata, Candida parapsilosis, and Candida krusei isolates (EUCAST/CLSI AMB MIC 0.125-1 mg/L) were studied in the in vitro PK/PD model simulating L-AMB Cmax = 0.25-64 mg/L and t1/2 = 9 h. The model was validated with one susceptible and one resistant Candida albicans isolate. The Cmax/MIC-log10CFU/mL reduction from the initial inoculum was analyzed with the Emax model, and Monte Carlo analysis was performed for the standard (3 mg/kg with Cmax = 21.87 ± 12.47 mg/L) and higher (5 mg/kg with Cmax = 83 ± 35.2 mg/L) L-AMB dose. A ≥1.5 log10CFU/mL reduction was found at L-AMB Cmax = 8 mg/L against C. albicans, C. parapsilosis, and C. krusei isolates (MIC 0.25-0.5 mg/L) whereas L-AMB Cmax ≥ 32 mg/L was required for C. glabrata isolates. The in vitro PK/PD relationship followed a sigmoidal pattern (R2 ≥ 0.85) with a mean Cmax/MIC required for stasis of 2.1 for C. albicans (close to the in vivo stasis), 24/17 (EUCAST/CLSI) for C. glabrata, 8 for C. parapsilosis, and 10 for C. krusei. The probability of target attainment was ≥99% for C. albicans wild-type (WT) isolates with 3 mg/kg and for wild-type isolates of the other species with 5 mg/kg. L-AMB was four- to eightfold less active against the included non-C. albicans species than C. albicans. A standard 3-mg/kg dose is pharmacodynamically sufficient for C. albicans whereas our data suggest that 5 mg/kg may be recommendable for the included non-C. albicans species.

Asunto(s)

Anfotericina B , Antifúngicos , Candida , Pruebas de Sensibilidad Microbiana , Método de Montecarlo , Anfotericina B/farmacocinética , Anfotericina B/farmacología , Antifúngicos/farmacocinética , Antifúngicos/farmacología , Candida/efectos de los fármacos , Farmacorresistencia Fúngica , Candida glabrata/efectos de los fármacos , Candida albicans/efectos de los fármacos , Candidiasis/tratamiento farmacológico , Candidiasis/microbiología , Humanos

RESUMEN

Keratitis is a corneal infection caused by various bacteria and fungi. Eye drop treatment of keratitis involves significant challenges due to difficulties in administration, inefficiencies in therapeutic dosage, and frequency of drug applications. All these are troublesome and result in unsuccessful treatment, high cost, time loss, development of drug resistance by microorganisms, and a massive burden on human health and the healthcare system. Most of the antibacterial and antifungal medications are non-water-soluble and/or include toxic drug formulations. Here, the aim was to develop drug-loaded contact lenses with therapeutic dosage formulations and extended drug release capability as an alternative to eye drops, by employing supercritical carbon dioxide (ScCO2) as a drug impregnation solvent to overcome inefficient ophthalmic drug use. ScCO2, known as a green solvent, has very low viscosity which provides high mass transfer power and could enhance drug penetration into contact lenses much better with respect to drug loading using other solvents. Here, moxifloxacin (MOX) antibiotic and amphotericin B (AMB) antifungal medicines were separately loaded into commercially available silicone hydrogel contact lenses through 1) drug adsorption from the aqueous solutions and 2) impregnation techniques via ScCO2 and their efficacies were compared. Drug impregnation parameters, i.e., 8-25 MPa pressure, 310-320 K temperature, 2-16-hour impregnation times, and the presence of ethanol as polar co-solvent were investigated for the optimization of the ScCO2 drug impregnation process. The highest drug loading and long-term release kinetic from the contact lenses were obtained at 25 MPa and 313 K with 2.5 h impregnation time by using 1 % ethanol (by volume). Furthermore, antibacterial/antifungal activities of the MOX- and AMB-impregnated contact lenses were effective against in vitro Pseudomonas aeruginosa (ATCC 10145) bacteria and Fusarium solani (ATCC 36031) fungus for up to one week. Consequently, the ScCO2 method can be effectively used to impregnate commercial contact lenses with drugs, and these can then be safely used for the treatment of keratitis. This offers a sustainable delivery system at effective dosage formulations with complete bacterial/fungal inhibition and termination, making it viable for real animal/human applications.

Asunto(s)

Anfotericina B , Antibacterianos , Antifúngicos , Dióxido de Carbono , Queratitis , Moxifloxacino , Dióxido de Carbono/química , Queratitis/tratamiento farmacológico , Queratitis/microbiología , Antibacterianos/química , Antibacterianos/administración & dosificación , Antibacterianos/farmacología , Antifúngicos/química , Antifúngicos/administración & dosificación , Moxifloxacino/administración & dosificación , Moxifloxacino/química , Moxifloxacino/farmacología , Anfotericina B/administración & dosificación , Anfotericina B/química , Anfotericina B/farmacología , Liberación de Fármacos , Lentes de Contacto/microbiología , Fusarium/efectos de los fármacos , Humanos , Hidrogeles/química , Sistemas de Liberación de Medicamentos , Solventes/química , Infecciones Fúngicas del Ojo/tratamiento farmacológico , Infecciones Fúngicas del Ojo/microbiología

RESUMEN

Fusarium oxysporum is a cross-kingdom pathogen that infects humans, animals, and plants. The primary concern regarding this genus revolves around its resistance profile to multiple classes of antifungals, particularly azoles. However, the resistance mechanism employed by Fusarium spp. is not fully understood, thus necessitating further studies to enhance our understanding and to guide future research towards identifying new drug targets. Here, we employed an untargeted proteomic approach to assess the differentially expressed proteins in a soil isolate of Fusarium oxysporum URM7401 cultivated in the presence of amphotericin B and fluconazole. In response to antifungals, URM7401 activated diverse interconnected pathways, such as proteins involved in oxidative stress response, proteolysis, and lipid metabolism. Efflux proteins, antioxidative enzymes and M35 metallopeptidase were highly expressed under amphotericin B exposure. Antioxidant proteins acting on toxic lipids, along with proteins involved in lipid metabolism, were expressed during fluconazole exposure. In summary, this work describes the protein profile of a resistant Fusarium oxysporum soil isolate exposed to medical antifungals, paving the way for further targeted research and discovering new drug targets.

Asunto(s)

Anfotericina B , Antifúngicos , Fluconazol , Proteínas Fúngicas , Fusarium , Proteómica , Microbiología del Suelo , Fusarium/efectos de los fármacos , Fusarium/metabolismo , Fusarium/genética , Antifúngicos/farmacología , Antifúngicos/metabolismo , Fluconazol/farmacología , Anfotericina B/farmacología , Proteínas Fúngicas/genética , Proteínas Fúngicas/metabolismo , Farmacorresistencia Fúngica , Pruebas de Sensibilidad Microbiana , Proteoma/análisis

RESUMEN

Cryptococcus neoformans is at the top of the list of "most wanted" human pathogens. Only three classes of antifungal drugs are available for the treatment of cryptococcosis. Studies on antifungal resistance mechanisms are limited to the investigation of how a particular antifungal drug induces resistance to a particular drug, and the impact of stresses other than antifungals on the development of antifungal resistance and even cross-resistance is largely unexplored. The endoplasmic reticulum (ER) is a ubiquitous subcellular organelle of eukaryotic cells. Brefeldin A (BFA) is a widely used chemical inducer of ER stress. Here, we found that both weak and strong selection by BFA caused aneuploidy formation in C. neoformans, mainly disomy of chromosome 1, chromosome 3, and chromosome 7. Disomy of chromosome 1 conferred cross-resistance to two classes of antifungal drugs: fluconazole and 5-flucytosine, as well as hypersensitivity to amphotericin B. However, drug resistance was unstable, due to the intrinsic instability of aneuploidy. We found overexpression of AFR1 on Chr1 and GEA2 on Chr3 phenocopied BFA resistance conferred by chromosome disomy. Overexpression of AFR1 also caused resistance to fluconazole and hypersensitivity to amphotericin B. Furthermore, a strain with a deletion of AFR1 failed to form chromosome 1 disomy upon BFA treatment. Transcriptome analysis indicated that chromosome 1 disomy simultaneously upregulated AFR1, ERG11, and other efflux and ERG genes. Thus, we posit that BFA has the potential to drive the rapid development of drug resistance and even cross-resistance in C. neoformans, with genome plasticity as the accomplice.

Asunto(s)

Aneuploidia , Antifúngicos , Brefeldino A , Cryptococcus neoformans , Farmacorresistencia Fúngica , Cryptococcus neoformans/efectos de los fármacos , Cryptococcus neoformans/genética , Brefeldino A/farmacología , Antifúngicos/farmacología , Farmacorresistencia Fúngica/genética , Fluconazol/farmacología , Anfotericina B/farmacología , Proteínas Fúngicas/genética , Proteínas Fúngicas/metabolismo , Pruebas de Sensibilidad Microbiana , Flucitosina/farmacología , Humanos , Estrés del Retículo Endoplásmico/efectos de los fármacos

RESUMEN

BACKGROUND: Bacterial aggregation has been shown to occur in synovial fluid which are resistant to high concentrations of antibiotics. Yet the propensity of Candida spp. to form aggregates is unknown. OBJECTIVE: To assess the ability of numerous Candida spp. to form synovial fluid aggregates and the clinical ramifications of the aggregates. METHODS: Nine different Candidal prosthetic joint infection clinical isolates were evaluated for their ability to form aggregates at static and dynamic conditions and their resistance to high concentrations of amphotericin. Furthermore, the ability of tissue plasminogen activator (TPA) to disrupt the aggregates and enhance amphotericin activity was assessed. RESULTS: The results show that all species of Candida spp. evaluated formed aggregates in synovial fluid under dynamic conditions that were resistant to amphotericin. Yet no aggregates formed in tryptic soy broth under any conditions or in synovial fluid under static conditions. As well, when TPA was combined with amphotericin there was a statistically significant decrease (p < .005) in the amount of colony forming units per mL for all Candidal species evaluated. Interestingly, for Candida krusei there was no colony forming units observed after exposure to TPA and amphotericin. CONCLUSION: Our findings suggest that Candidal species form synovial fluid aggregates that are resistant to high dose amphotericin similar to those that occur with bacteria. However, the varying ability of the different Candida spp. to form hyphae and pseudohyphae compared to yeast cells may have direct impacts on the hardiness of the aggregates and thereby have clinical ramifications with respect to treatment durations.

Asunto(s)

Anfotericina B , Antifúngicos , Candida , Infecciones Relacionadas con Prótesis , Líquido Sinovial , Líquido Sinovial/microbiología , Candida/efectos de los fármacos , Candida/aislamiento & purificación , Candida/clasificación , Humanos , Infecciones Relacionadas con Prótesis/microbiología , Infecciones Relacionadas con Prótesis/tratamiento farmacológico , Antifúngicos/farmacología , Antifúngicos/uso terapéutico , Anfotericina B/farmacología , Anfotericina B/uso terapéutico , Pruebas de Sensibilidad Microbiana , Candidiasis/microbiología , Candidiasis/tratamiento farmacológico , Activador de Tejido Plasminógeno , Farmacorresistencia Fúngica

RESUMEN

BACKGROUND: Candida vulturna is an emerging pathogen belonging to the Metshnikowiaceae family together with Candida auris and Candida haemulonii species complex. Some strains of this species were reported to be resistant to several antifungal agents. OBJECTIVES: This study aims to address identification difficulties, evaluate antiungal susceptibilities and explore the molecular mechanisms of azole resistance of Candida vulturna. METHODS: We studied five C. vulturna clinical strains isolated in three Colombian cities. Identification was performed by phenotypical, proteomic and molecular methods. Antifungal susceptibility testing was performed following CLSI protocol. Its ERG11 genes were sequenced and a substitution was encountered in azole resistant isolates. To confirm the role of this substitution in the resistance phenotype, Saccharomyces cerevisiae strains with a chimeric ERG11 gene were created. RESULTS: Discrepancies in identification methods are highlighted. Sequencing confirmed the identification as C. vulturna. Antifungal susceptibility varied among strains, with four strains exhibiting reduced susceptibility to azoles and amphotericin B. ERG11 sequencing showed a point mutation (producing a P135S substitution) that was associated with the azole-resistant phenotype. CONCLUSIONS: This study contributes to the understanding of C. vulturna's identification challenges, its susceptibility patterns, and sheds light on its molecular mechanisms of azole resistance.

Asunto(s)

Antifúngicos , Azoles , Candida , Candidiasis , Pruebas de Sensibilidad Microbiana , Antifúngicos/farmacología , Azoles/farmacología , Candida/efectos de los fármacos , Candida/genética , Candida/clasificación , Candida/aislamiento & purificación , Candidiasis/microbiología , Humanos , Farmacorresistencia Fúngica Múltiple/genética , Colombia , Anfotericina B/farmacología , Farmacorresistencia Fúngica/genética , Mutación Puntual , Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/efectos de los fármacos , Sistema Enzimático del Citocromo P-450/genética , Proteínas Fúngicas/genética , Análisis de Secuencia de ADN , Proteínas de Saccharomyces cerevisiae

RESUMEN

BACKGROUND: Vulvovaginal candidiasis is a common fungal infection that affects the female lower genital tract. This study determined the major risk factors associated with vulvovaginal infection (VVI) in the Ashanti region of Ghana and also determined the antifungal resistance patterns of Candida albicans isolates to some antifungals. METHODS: Three hundred and fifty (350) high vaginal swab (HVS) samples were collected from women who presented with signs and symptoms of VVI. A structured questionnaire was administered to one hundred and seventy-two (172) of the women. HVS samples were cultured on Sabouraud dextrose agar with 2% chloramphenicol. The polymerase chain reaction was employed to confirm C. albicans. Antifungal susceptibility testing was performed and the susceptibility of C. albicans isolates to fluconazole, clotrimazole, amphotericin B, nystatin, miconazole and 5-flurocytosine were assessed. RESULTS: Vaginal infection was most prevalent amongst females in their reproductive age (21 to 30 years; 63.0%). The study found a significant association between vaginal infections and some risk factors such as sexual practices (p < 0.001), antibiotic misuse (p < 0.05), poor personal hygiene (p < 0.005) and birth control methods (p < 0.049). Out of the 350 HVS samples collected, 112 yielded yeast cells with 65 (58%) identified as C. albicans. The C. albicans isolates were resistant to 5' flucytosine (100%), fluconazole (70%), voriconazole (69.2%), miconazole (58.5%) and nystatin (49.2%). C. albicans isolates were more susceptible to amphotericin B (53.8%) and clotrimazole (45.1%), although an appreciable number of isolates showed resistance (46.1% and 52.3%, respectively). CONCLUSION: There should be nationwide education on all associated risk factors of VVI. Also, use of the various antifungal agents in vaginal candidiasis should proceed after antifungal susceptibility testing to ensure efficacious use of these agents.

Asunto(s)

Antifúngicos , Candida albicans , Candidiasis Vulvovaginal , Farmacorresistencia Fúngica , Pruebas de Sensibilidad Microbiana , Humanos , Femenino , Candidiasis Vulvovaginal/microbiología , Candidiasis Vulvovaginal/epidemiología , Candidiasis Vulvovaginal/tratamiento farmacológico , Ghana/epidemiología , Candida albicans/aislamiento & purificación , Candida albicans/efectos de los fármacos , Adulto , Antifúngicos/farmacología , Antifúngicos/uso terapéutico , Adulto Joven , Factores de Riesgo , Adolescente , Vagina/microbiología , Recurrencia , Centros de Atención Terciaria/estadística & datos numéricos , Anfotericina B/uso terapéutico , Anfotericina B/farmacología , Persona de Mediana Edad

RESUMEN

Leishmaniases, caused by Leishmania parasites, are widespread and pose significant health risks globally. Visceral leishmaniasis (VL) is particularly prevalent in Brazil, with high morbidity and mortality rates. Traditional treatments, such as pentavalent antimonials, have limitations due to toxicity and resistance. Therefore, exploring new compounds like lectins is crucial. Concanavalin A (ConA) has shown promise in inhibiting Leishmania growth. This study aimed to evaluate its leishmanicidal effect on L. infantum promastigotes and understand its mechanism of action. In vitro tests demonstrated inhibition of promastigote growth when treated with ConA, with IC50 values ranging from 3 to 5 µM over 24-72 h. This study suggests that ConA interacts with L. infantum glycans. Additionally, ConA caused damage to the membrane integrity of parasites and induced ROS production, contributing to parasite death. Scanning electron microscopy confirmed morphological alterations in treated promastigotes. ConA combined with the amphotericin B (AmB) showed synergistic effects, reducing the required dose of AmB, and potentially mitigating its toxicity. ConA demonstrated no cytotoxic effects on macrophages, instead stimulating their proliferation. These findings reinforce that lectin exhibits promising leishmanicidal activity against L. infantum promastigotes, making ConA a potential candidate for leishmaniasis treatment.

Asunto(s)

Antiprotozoarios , Canavalia , Concanavalina A , Leishmania infantum , Leishmania infantum/efectos de los fármacos , Concanavalina A/farmacología , Animales , Antiprotozoarios/farmacología , Antiprotozoarios/química , Semillas/química , Especies Reactivas de Oxígeno/metabolismo , Ratones , Anfotericina B/farmacología , Lectinas/farmacología , Lectinas/química , Lectinas/metabolismo , Lectinas de Plantas/farmacología , Lectinas de Plantas/química , Macrófagos/efectos de los fármacos , Macrófagos/metabolismo , Macrófagos/parasitología

RESUMEN

Liposomal amphotericin B is an important frontline drug for the treatment of visceral leishmaniasis, a neglected disease of poverty. The mechanism of action of amphotericin B (AmB) is thought to involve interaction with ergosterol and other ergostane sterols, resulting in disruption of the integrity and key functions of the plasma membrane. Emergence of clinically refractory isolates of Leishmania donovani and L. infantum is an ongoing issue and knowledge of potential resistance mechanisms can help to alleviate this problem. Here we report the characterisation of four independently selected L. donovani clones that are resistant to AmB. Whole genome sequencing revealed that in three of the moderately resistant clones, resistance was due solely to the deletion of a gene encoding C24-sterol methyltransferase (SMT1). The fourth, hyper-resistant resistant clone (>60-fold) was found to have a 24 bp deletion in both alleles of a gene encoding a putative cytochrome P450 reductase (P450R1). Metabolic profiling indicated these parasites were virtually devoid of ergosterol (0.2% versus 18% of total sterols in wild-type) and had a marked accumulation of 14-methylfecosterol (75% versus 0.1% of total sterols in wild-type) and other 14-alpha methylcholestanes. These are substrates for sterol 14-alpha demethylase (CYP51) suggesting that this enzyme may be a bona fide P450R specifically involved in electron transfer from NADPH to CYP51 during catalysis. Deletion of P450R1 in wild-type cells phenocopied the metabolic changes observed in our AmB hyper-resistant clone as well as in CYP51 nulls. Likewise, addition of a wild type P450R1 gene restored sterol profiles to wild type. Our studies indicate that P450R1 is essential for L. donovani amastigote viability, thus loss of this gene is unlikely to be a driver of clinical resistance. Nevertheless, investigating the mechanisms underpinning AmB resistance in these cells provided insights that refine our understanding of the L. donovani sterol biosynthetic pathway.

Asunto(s)

Resistencia a Medicamentos , Leishmania donovani , Leishmaniasis Visceral , Esterol 14-Desmetilasa , Leishmania donovani/enzimología , Esterol 14-Desmetilasa/metabolismo , Esterol 14-Desmetilasa/genética , Leishmaniasis Visceral/parasitología , Leishmaniasis Visceral/tratamiento farmacológico , Anfotericina B/farmacología , Proteínas Protozoarias/metabolismo , Proteínas Protozoarias/genética , NADPH-Ferrihemoproteína Reductasa/metabolismo , NADPH-Ferrihemoproteína Reductasa/genética , Antiprotozoarios/farmacología , Humanos , Ergosterol/metabolismo

RESUMEN

Aim: To evaluate the antifungal activity of mangiferin against Candida spp. resistant to fluconazole.Materials & methods: The antifungal activity of mangiferin was assessed using broth microdilution and its interaction with azoles and amphotericin B was evaluated by checkerboard. The activity of mangiferin against Candida spp. biofilms was assessed using the MTT colorimetric assay and its possible mechanism of action was evaluated using flow cytometry.Results: Mangiferin showed activity against Candida albicans, Candida tropicalis and Candida parapsilosis resistant to fluconazole and showed synergism with azoles and amphotericin B. Mangiferin increased the activity of antifungals against Candida biofilms and caused depolarization of the mitochondrial membrane and externalization of phosphatidylserine, suggesting apoptosis.Conclusion: mangiferin combined with antifungals has potential against Candida spp.

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Candida is a type of fungus that can make people ill. Over time, many species of Candida have found ways to resist the drugs used to kill them. It is important to find new drugs. We decided to see if a substance called mangiferin works against Candida. We found that mangiferin works against Candida and may help other drugs to work better. We still need to do more studies to find out whether mangiferin can help prevent diseases caused by Candida in the future.

Asunto(s)

Anfotericina B , Antifúngicos , Biopelículas , Candida , Farmacorresistencia Fúngica , Sinergismo Farmacológico , Fluconazol , Pruebas de Sensibilidad Microbiana , Xantonas , Antifúngicos/farmacología , Xantonas/farmacología , Fluconazol/farmacología , Biopelículas/efectos de los fármacos , Farmacorresistencia Fúngica/efectos de los fármacos , Anfotericina B/farmacología , Candida/efectos de los fármacos , Humanos , Apoptosis/efectos de los fármacos , Candida albicans/efectos de los fármacos , Azoles/farmacología

RESUMEN

PURPOSE: Due to the potential for Aspergillus species to cause lethal infections and the rising rates of antifungal resistance, the significance of antifungal susceptibility tests has increased. We aimed to assess the sensitivities of Aspergillus species to amphotericin B (AMB), voriconazole (VOR), itraconazole (ITZ), and caspofungin (CAS) using disk diffusion (DD) and gradient diffusion (GD) methods and compare them with broth microdilution (BMD) as the reference susceptibility method. METHODS: The study involved 62 Aspergillus fumigatus, 28 Aspergillus flavus, and 16 Aspergillus terreus isolates, totaling 106 Aspergillus isolates. BMD and DD methods were performed in accordance with CLSI M38-A2 and CLSI M51-A documents, respectively. The GD method utilized nonsupplemented Mueller Hinton agar (MHA) as the medium. RESULTS: In the BMD method, the lowest minimal inhibitory concentration (MIC)90 or minimal effective concentration (MEC)90 values were observed for VOR and CAS (0.5 µg/mL and 0.06 µg/mL, respectively). AMB and ITZ MIC90 values were both 2 µg/mL. In our comparison of the GD method with the BMD method at ±2 dilution, we observed essential agreement rates of 91.6%, 99.1%, 100%, and 38.6% for AMB, VOR, ITZ, and CAS, respectively. When comparing DD and BMD methods, we found categorical agreement rates of 65.1%, 99.1%, 77.3%, and 100% for AMB, VOR, ITZ, and CAS, respectively. For GD and BMD methods, these rates were 79.2%, 99.1%, 87.8%, and 100%. CONCLUSIONS: Given the high essential and categorical agreement rates, we posit that the GD method is a viable alternative to the BMD method for AMB, ITZ and VOR but not for CAS. In addition, the use of nonsupplemented MHA in the GD method proves advantageous due to its cost-effectiveness and widespread availability compared to other growth media.

Asunto(s)

Antifúngicos , Aspergilosis , Aspergillus , Pruebas de Sensibilidad Microbiana , Voriconazol , Antifúngicos/farmacología , Humanos , Aspergillus/efectos de los fármacos , Aspergillus/aislamiento & purificación , Pruebas de Sensibilidad Microbiana/métodos , Aspergilosis/microbiología , Voriconazol/farmacología , Anfotericina B/farmacología , Caspofungina/farmacología , Itraconazol/farmacología , Equinocandinas/farmacología

RESUMEN

In recent years, the incidence and drug resistance of Candida parapsilosis have increased. Our study aimed to determine the antifungal sensitivity of C. parapsilosis and the clinical and demographic characteristics of children with candidemia. Two hundred pediatric patients with C. parapsilosis candidemia were included in the study between 1 January 2010 and 1 August 2023. Clinical samples were evaluated on a BACTEC-FX-40 automatic blood culture device (Becton Dickinson, USA). Yeast isolates were identified to the species level via identification cards (YST) using the VITEK 2 Compact (bioMeriéux, France) system. Antifungal susceptibility was performed using antifungal cell cards (AST-YST01). Approval for the study was received from the "University Faculty of Medicine" Hospital Clinical Research Ethics Committee. Non-catheter candidemia was detected in 127 (63.5%) patients, and catheter-related candidemia was detected in 73 (36.5%) patients. It was observed that the patients' history of malignancy, mechanical ventilation, urinary catheter, nasogastric tube, and intensive care unit stay was associated with C. parapsilosis mortality. The mortality rate from candidemia was 9.5%. The most frequently preferred antifungal agents were amphotericin B and fluconazole. The fluconazole drug resistance rate was found to be 6%, and the amphotericin B drug resistance rate was 4%. Because C. parapsilosis candidemia mortality rates can be high depending on risk factors and clinical characteristics, it is important to initiate appropriate and timely antifungal therapy. We think that our study can provide important information about the clinical profiles, distributions, susceptibility profiles, and control of antifungal resistance of C. parapsilosis isolates. IMPORTANCE: It has been observed that the frequency and antifungal resistance of Candida parapsilosis have increased recently. In our study, we aimed to determine the antifungal sensitivity of C. parapsilosis and the clinical and demographic characteristics of children with candidemia. It was observed that the patients' history of malignancy, mechanical ventilation, urinary catheter, nasogastric tube, and intensive care stay was associated with C. parapsilosis mortality. The mortality rate from candidemia was 9.5%. The most frequently preferred antifungal agents were amphotericin B and fluconazole. The fluconazole drug resistance rate was found to be 6%, and the amphotericin B drug resistance rate was 4%. Because C. parapsilosis candidemia mortality rates can be high depending on risk factors and clinical characteristics, it is important to initiate appropriate and timely antifungal therapy.

Asunto(s)

Antifúngicos , Candida parapsilosis , Candidemia , Farmacorresistencia Fúngica , Pruebas de Sensibilidad Microbiana , Centros de Atención Terciaria , Humanos , Candidemia/microbiología , Candidemia/tratamiento farmacológico , Candidemia/mortalidad , Antifúngicos/farmacología , Antifúngicos/uso terapéutico , Masculino , Femenino , Turquía/epidemiología , Niño , Preescolar , Candida parapsilosis/efectos de los fármacos , Candida parapsilosis/aislamiento & purificación , Lactante , Adolescente , Fluconazol/uso terapéutico , Fluconazol/farmacología , Anfotericina B/uso terapéutico , Anfotericina B/farmacología , Recién Nacido , Candida/efectos de los fármacos , Candida/aislamiento & purificación , Candida/clasificación

RESUMEN

Cryptococcus neoformans causes cryptococcosis, one of the most prevalent fungal diseases, generally characterized by meningitis. There is a limited and not very effective number of drugs available to combat this disease. In this manuscript, we show the host defense peptide mimetic brilacidin (BRI) as a promising antifungal drug against C. neoformans. BRI can affect the organization of the cell membrane, increasing the fungal cell permeability. We also investigated the effects of BRI against the model system Saccharomyces cerevisiae by analyzing libraries of mutants grown in the presence of BRI. In S. cerevisiae, BRI also affects the cell membrane organization, but in addition the cell wall integrity pathway and calcium metabolism. In vivo experiments show BRI significantly reduces C. neoformans survival inside macrophages and partially clears C. neoformans lung infection in an immunocompetent murine model of invasive pulmonary cryptococcosis. We also observed that BRI interacts with caspofungin (CAS) and amphotericin (AmB), potentiating their mechanism of action against C. neoformans. BRI + CAS affects endocytic movement, calcineurin, and mitogen-activated protein kinases. Our results indicate that BRI is a novel antifungal drug against cryptococcosis. IMPORTANCE: Invasive fungal infections have a high mortality rate causing more deaths annually than tuberculosis or malaria. Cryptococcosis, one of the most prevalent fungal diseases, is generally characterized by meningitis and is mainly caused by two closely related species of basidiomycetous yeasts, Cryptococcus neoformans and Cryptococcus gattii. There are few therapeutic options for treating cryptococcosis, and searching for new antifungal agents against this disease is very important. Here, we present brilacidin (BRI) as a potential antifungal agent against C. neoformans. BRI is a small molecule host defense peptide mimetic that has previously exhibited broad-spectrum immunomodulatory/anti-inflammatory activity against bacteria and viruses. BRI alone was shown to inhibit the growth of C. neoformans, acting as a fungicidal drug, but surprisingly also potentiated the activity of caspofungin (CAS) against this species. We investigated the mechanism of action of BRI and BRI + CAS against C. neoformans. We propose BRI as a new antifungal agent against cryptococcosis.

Asunto(s)

Antifúngicos , Criptococosis , Cryptococcus neoformans , Saccharomyces cerevisiae , Antifúngicos/farmacología , Cryptococcus neoformans/efectos de los fármacos , Animales , Ratones , Criptococosis/tratamiento farmacológico , Criptococosis/microbiología , Saccharomyces cerevisiae/efectos de los fármacos , Saccharomyces cerevisiae/genética , Modelos Animales de Enfermedad , Macrófagos/microbiología , Macrófagos/efectos de los fármacos , Macrófagos/inmunología , Pruebas de Sensibilidad Microbiana , Caspofungina/farmacología , Femenino , Membrana Celular/efectos de los fármacos , Membrana Celular/metabolismo , Anfotericina B/farmacología

RESUMEN

Aim: Currently, we have limited armamentarium of antifungal agents against Mucorales. There is an urgent need to discover novel antifungal agents that are effective, safe and affordable. Materials & methods: In this study, the anti-Mucorale action of native lactoferrin (LF) and its functional fragments CLF, RR6 and LFcin against three common Mucorale species are reported. The synergistic action of LF with antifungal agents like amphotericin B, isavuconazole and posaconazole was analyzed using checkerboard technique. Results: All the three mucor species showed inhibition when treated with fragments. The checkerboard assay confirmed that native LF showed the best synergistic action against Mucorales in combination with Amphotericin B. Conclusion: These results highlight the potential therapeutic value of native LF against Mucorales.

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Black fungus, or 'mucormycosis', is a dangerous fungal infection. Normally, it affects people with a weakened immune system. It is only treatable when diagnosed early. It spreads by breathing the fungus in, eating contaminated food or direct contact with an infected wound. There are not many medicines that can treat this type of fungus, so it is important to find new ones. In this study, we tested a natural protein called lactoferrin and some of its building blocks, called peptides, to see if they could stop the fungus from growing. Lactoferrin and its peptides could stop the fungus from growing, especially when used with a medicine called amphotericin B. This means that lactoferrin could potentially be a helpful treatment for this fungal infection.

Asunto(s)

Anfotericina B , Antifúngicos , Sinergismo Farmacológico , Lactoferrina , Pruebas de Sensibilidad Microbiana , Mucormicosis , Lactoferrina/farmacología , Lactoferrina/uso terapéutico , Antifúngicos/farmacología , Antifúngicos/uso terapéutico , Mucormicosis/tratamiento farmacológico , Mucormicosis/microbiología , Anfotericina B/farmacología , Humanos , Triazoles/farmacología , Triazoles/uso terapéutico , Mucorales/efectos de los fármacos , Mucor/efectos de los fármacos , Piridinas/farmacología , Piridinas/uso terapéutico , Nitrilos/farmacología , Nitrilos/uso terapéutico