RESUMO
The development of effective therapy is necessary because the patients have to contend with long-term therapy as skin fungal infections usually relapse and are hardly treated. Despite being a potent antifungal agent, luliconazole (LCZ) has certain shortcomings such as limited skin penetration, low solubility in aqueous medium, and poor skin retention. Solid Lipid Nanoparticles (SLNs) were developed using biodegradable lipids by solvent injection method and were embodied into the gel base for topical administration. After in-vitro characterizations of the formulations, molecular interactions of the drug with excipients were analyzed using in-silico studies. Ex-vivo release was determined in contrast to the pure LCZ and the commercial formulation followed by in-vivo skin localization, skin irritation index, and antifungal activity. The prepared SLNs have an average particle size of 290.7 nm with no aggregation of particles and homogenous gels containing SLNs with ideal rheology and smooth texture properties were successfully prepared. The ex-vivo LCZ release from the SLN gel was lower than the commercial formulation whereas its skin deposition and skin retention were higher as accessed by CLSM studies. The drug reaching the systemic circulation and the skin irritation potential were found to be negligible. The solubility and drug retention in the skin were both enhanced by the development of SLNs as a carrier. Thus, SLNs offer significant advantages by delivering long lasting concentrations of LCZ at the site of infection for a complete cure of the fungal load together with skin localization of the topical antifungal drug.
Assuntos
Antifúngicos , Géis , Imidazóis , Nanopartículas , Tamanho da Partícula , Pele , Solubilidade , Antifúngicos/administração & dosagem , Antifúngicos/farmacocinética , Antifúngicos/farmacologia , Nanopartículas/química , Pele/metabolismo , Pele/efeitos dos fármacos , Animais , Imidazóis/administração & dosagem , Imidazóis/farmacocinética , Imidazóis/química , Imidazóis/farmacologia , Administração Tópica , Química Farmacêutica/métodos , Absorção Cutânea/efeitos dos fármacos , Lipídeos/química , Portadores de Fármacos/química , Administração Cutânea , Excipientes/química , Liberação Controlada de FármacosRESUMO
BACKGROUND: The incidence of fungal urinary tract infections (UTIs) has dramatically increased in the past decades, with Candida arising as the predominant etiological agent. Managing these infections poses a serious challenge to clinicians, especially with the emergence of fluconazole-resistant (FLC-R) Candida species. In this study, we aimed to determine the mechanisms of fluconazole resistance in urinary Candida spp. isolated from hospitalized patients in Alexandria, Egypt, assess the correlation between fluconazole resistance and virulence, and explore potential treatment options for UTIs caused by FLC-R Candida strains. RESULTS: Fluconazole susceptibility testing of 34 urinary Candida isolates indicated that 76.5% were FLC-R, with a higher prevalence of resistance recorded in non-albicans Candida spp. (88.9%) than in Candida albicans (62.5%). The calculated Spearman's correlation coefficients implied significant positive correlations between fluconazole minimum inhibitory concentrations and both biofilm formation and phospholipase production. Real-time PCR results revealed that most FLC-R isolates (60%) significantly overexpressed at least one efflux pump gene, while 42.3% significantly upregulated the ERG11 gene. The most prevalent mutation detected upon ERG11 sequencing was G464S, which is conclusively linked to fluconazole resistance. The five repurposed agents: amikacin, colistin, dexamethasone, ketorolac, and sulfamethoxazole demonstrated variable fluconazole-sensitizing activities in vitro, with amikacin, dexamethasone, and colistin being the most effective. However, the fluconazole/colistin combination produced a notable reduction (49.1%) in bladder bioburden, a 50% decrease in the inflammatory response, and tripled the median survival span relative to the untreated murine models. CONCLUSIONS: The fluconazole/colistin combination offers a promising treatment option for UTIs caused by FLC-R Candida, providing an alternative to the high-cost, tedious process of novel antifungal drug discovery in the battle against antifungal resistance.
Assuntos
Antifúngicos , Biofilmes , Candida , Candidíase , Reposicionamento de Medicamentos , Farmacorresistência Fúngica , Fluconazol , Testes de Sensibilidade Microbiana , Infecções Urinárias , Fluconazol/farmacologia , Egito , Humanos , Farmacorresistência Fúngica/genética , Antifúngicos/farmacologia , Candida/efeitos dos fármacos , Candida/genética , Candida/isolamento & purificação , Candida/classificação , Candidíase/microbiologia , Candidíase/tratamento farmacológico , Candidíase/urina , Infecções Urinárias/microbiologia , Infecções Urinárias/tratamento farmacológico , Animais , Biofilmes/efeitos dos fármacos , Biofilmes/crescimento & desenvolvimento , Camundongos , Virulência/genética , Virulência/efeitos dos fármacos , Feminino , Masculino , Fosfolipases/genética , Fosfolipases/metabolismo , Proteínas Fúngicas/genética , Proteínas Fúngicas/metabolismoRESUMO
Xiaozhou mustard (Brassica napiformis) root tuber, a traditional fermented vegetable, has a long history in Rongan County, Guangxi Province. However, the frequent occurrence of root tuber sour rot by Geotrichum candidum (G. candidum) has seriously reduced Xiaozhou mustard production and quality in recent years. The objective of the present study is to investigate the antifungal efficacy of 2-chloro-5-trifluoromethoxybenzeneboronic acid (Cl-F-BBA) against G. candidum and its possible mechanisms. The results revealed that a concentration of 0.25 mg/mL Cl-F-BBA completely halted mycelial growth and spore germination. Furthermore, a slightly lower concentration of 0.20 mg/mL was sufficient to compromise the integrity of the plasma membrane in mycelia and mitochondria, leading to a reduction in respiratory rate, activities of malate dehydrogenase (MDH), and succinate dehydrogenase (SDH), ATP content, and energy charge. This concentration also significantly disordered antioxidant metabolism, resulting in the accumulation of reactive oxygen species (ROS) and malondialdehyde (MDA), and caused intracellular leakage in mycelia. In vivo experiments further demonstrated that Xiaozhou mustard root tubers treated with Cl-F-BBA exhibited markedly lower decay rates and lesion diameters compared to the control group. In summary, Cl-F-BBA presents a promising solution for controlling root tuber sour rot in Xiaozhou mustard caused by G. candidum.
Assuntos
Geotrichum , Doenças das Plantas , Raízes de Plantas , Geotrichum/efeitos dos fármacos , Raízes de Plantas/efeitos dos fármacos , Raízes de Plantas/microbiologia , Raízes de Plantas/crescimento & desenvolvimento , Doenças das Plantas/microbiologia , Doenças das Plantas/prevenção & controle , Mostardeira , Ácidos Borônicos/farmacologia , Antifúngicos/farmacologia , Micélio/efeitos dos fármacos , Micélio/crescimento & desenvolvimento , Espécies Reativas de Oxigênio/metabolismo , Tubérculos/microbiologiaRESUMO
Background: Pythium insidiosum (P. insidiosum) is the causative agent of pythiosis, an infectious disease with a high morbidity and fatality rate. Pythiosis cases have increased dramatically during the past ten years, particularly in tropical and subtropical areas. Sadly, microbiologists and medical professionals know very little about pythiosis, and the disease is frequently challenging to identify. It is frequently misdiagnosed as a fungal infection. Methods: We report two cases of pythiosis, one was Pythium keratitis, the other was cutaneous pythiosis. The patient with corneal infection had no underlying disease, while the patient with cutaneous pythiosis had a history of liver cirrhosis, diabetes, and psoriasis. The corneal sample and subcutaneous pus were sent for metagenomic Next-Generation Sequencing (mNGS). To further diagnose the isolated strain, P. insidiosum zoospores were induced to produce by co-incubation with sterile grass leaves in sterile pond water. Their zoospores were used as an inoculum for drug susceptibility testing by disk diffusion and broth microdilution method. Results: The mNGS of two cases were reported as P. insidiosum. Zoospores were produced after incubation 48h. The zoospores were collected for drug susceptibility assay. All antifungal drugs, antibacterial drugs of ß-Lactams, vancomycin, levofloxacin, ciprofloxacin, gentamicin, trimethoprim-sulfamethoxazole, clindamycin have no inhibitory activity against P. insidiosum in vitro. Minocycline, tigecycline, linezolid, erythromycin and azithromycin have significant in vitro activity against P. insidiosum. Based on the susceptibility results, the drug was changed from itraconazole to linezolid and minocycline, along with multiple debridements and drainage for cutaneous pythiosis. The patient was discharged after 24 days of treatment. Conclusions: Early and accurate identification, combined with aggressive surgical debridement and appropriate drug therapy, can greatly improve patient managements. Conventional culture and zoospore induction remain gold standard for diagnosis; however, DNA-based method should be performed simultaneously. The drug susceptibility testing provides profound effects on proper drug selection against P. insidiosum.
Assuntos
Antifúngicos , Testes de Sensibilidade Microbiana , Pitiose , Pythium , Pythium/isolamento & purificação , Pythium/efeitos dos fármacos , Pythium/genética , Humanos , Pitiose/diagnóstico , Pitiose/microbiologia , Pitiose/tratamento farmacológico , Antifúngicos/farmacologia , Antifúngicos/uso terapêutico , Masculino , Erros de Diagnóstico , Doenças Transmissíveis Emergentes/microbiologia , Doenças Transmissíveis Emergentes/diagnóstico , Doenças Transmissíveis Emergentes/tratamento farmacológico , Ceratite/microbiologia , Ceratite/diagnóstico , Ceratite/tratamento farmacológico , Pessoa de Meia-Idade , Sequenciamento de Nucleotídeos em Larga Escala , Feminino , IdosoRESUMO
Background: In the face of increasing antifungal resistance among Candida albicans biofilms, this study explores the efficacy of a combined treatment using Kangbainian lotion (KBN) and miconazole nitrate (MN) to address this challenge. Methods: Using UPLC-Q-TOF/MS Analysis for Identification of Active Compounds in KBN Lotion; FICI for synergy evaluation, XTT and ROS assays for biofilm viability and oxidative stress, fluorescence and confocal laser scanning microscopy (CLSM) for structural and viability analysis, and real-time fluorescence for gene expression. Conclusion: Our study indicates that the combined application of KBN and MN somewhat impacts the structural integrity of Candida albicans biofilms and affects the expression of several key genes involved in biofilm formation, including ALS1, ALS3, HWP1, HSP90, and CSH1. These preliminary findings suggest that there may be a synergistic effect between KBN and MN, potentially influencing not only the structural aspects of fungal biofilms but also involving the modulation of genetic pathways during their formation.
Assuntos
Antifúngicos , Biofilmes , Candida albicans , Farmacorresistência Fúngica , Sinergismo Farmacológico , Miconazol , Testes de Sensibilidade Microbiana , Biofilmes/efeitos dos fármacos , Candida albicans/efeitos dos fármacos , Antifúngicos/farmacologia , Miconazol/farmacologia , Espécies Reativas de Oxigênio/metabolismo , Viabilidade Microbiana/efeitos dos fármacos , Estresse Oxidativo/efeitos dos fármacos , Extratos Vegetais/farmacologia , Proteínas Fúngicas/genética , Proteínas Fúngicas/metabolismo , Regulação Fúngica da Expressão Gênica/efeitos dos fármacos , HumanosRESUMO
BACKGROUND: Sophorolipids are glycolipid biosurfactants with potential antibacterial, antifungal, and anticancer applications, rendering them promising for research. Therefore, this study hypothesizes that sophorolipids may have a notable impact on disrupting membrane integrity and triggering the production of reactive oxygen species, ultimately resulting in the eradication of pathogenic microbes. RESULTS: The current study resulted in the isolation of two Metschnikowia novel yeast strains. Sophorolipids production from these strains reached maximum yields of 23.24 g/l and 21.75 g/l, respectively, at the bioreactors level. Biosurfactants sophorolipids were characterized using FTIR and LC-MS techniques and found to be a mixture of acidic and lactonic forms with molecular weights of m/z 678 and 700. Our research elucidated sophorolipids' mechanism in disrupting bacterial and fungal membranes through ROS generation, confirmed by transmission electron microscopy and FACS analysis. The results showed that these compounds disrupted the membrane integrity and induced ROS production, leading to cell death in Klebsiella pneumoniae and Fusarium solani. In addition, the anticancer properties of sophorolipids were investigated on the A549 lung cancer cell line and found that sophorolipid-11D (SL-11D) and sophorolipid-11X (SL-11X) disrupted the actin cytoskeleton, as evidenced by immunofluorescence microscopy. The A549 cells were stained with Acridine orange/Ethidium bromide, which showed that they underwent necrosis. This was confirmed by flow cytometric analysis using Annexin/PI staining. The SL-11D and SL-11X molecules exhibited low levels of haemolytic activity and in-vitro cytotoxicity in HEK293, Caco-2, and L929 cell lines. CONCLUSION: In this work, novel yeast species CIG-11DT and CIG-11XT, isolated from the bee's gut, produce significant yields of sophorolipids without needing secondary oil sources, indicating a more economical production method. Our research shows that sophorolipids disrupt bacterial and fungal membranes via ROS production. They suggest they may act as chemo-preventive agents by inducing apoptosis in lung cancer cells, offering the potential for enhancing anticancer therapies.
Assuntos
Antifúngicos , Antineoplásicos , Metschnikowia , Estresse Oxidativo , Espécies Reativas de Oxigênio , Tensoativos , Antifúngicos/farmacologia , Antifúngicos/química , Antifúngicos/metabolismo , Humanos , Tensoativos/farmacologia , Tensoativos/metabolismo , Tensoativos/química , Estresse Oxidativo/efeitos dos fármacos , Antineoplásicos/farmacologia , Espécies Reativas de Oxigênio/metabolismo , Células A549 , Metschnikowia/metabolismo , Metschnikowia/efeitos dos fármacos , Fusarium/efeitos dos fármacos , Fusarium/metabolismo , Klebsiella pneumoniae/efeitos dos fármacos , Glicolipídeos/farmacologia , Glicolipídeos/metabolismo , Testes de Sensibilidade Microbiana , Ácidos OleicosRESUMO
Pichia kudriavzevii (formerly Candida krusei) poses a significant threat to immunocompromised patients due to its inherent resistance to various antifungal drugs. This study explored the anticandidal potential of citral, linalool, and carvacrol in combination with nystatin against P. kudriavzevii strains.Using the microdilution method following CLSI guidelines, Minimum Inhibitory Concentrations (MICs) and fungicidal concentrations (MFCs) were determined. Citral exhibited MIC values ranging from 50 to 100 µg/ml, averaging 70.24 ± 16.99 µg/ml, while carvacrol had MIC values of 50 to 100 µg/ml, averaging 86.90 ± 16.99 µg/ml. Linalool demonstrated weaker antifungal activity, with MIC values between 100 and 200 µg/ml, averaging 150 ± 38.73 µg/ml. The study assessed the synergistic effectsof these phenols with nystatin through fractional inhibitory concentration indices (FICIS). In addition, flow cytometry was employed to assess apoptosis induction in P. kudriavzevii cells.Carvacrol displayed a remarkable synergistic effect in combination with nystatin against all 21 isolates tested. Conversely, linalool showed synergy in 17 isolates, while citral exhibited synergy in only 2 isolates. These findings highlight distinct patterns of synergy between the different compounds and nystatin against P. kudriavzevii. Also, Carvacrol emerged as the most potent inducer of apoptosis across all P. kudriavzevii strains, followed by citral and linalool. This suggests that carvacrol not only possesses a stronger antifungal effect but also has a more pronounced ability to trigger programmed cell death in P. kudriavzevii. In conclusion, the study supports the potential of carvacrol, citral and linalool, as anticandidal agents, suggesting their supplementation with nystatin for treating P. kudriavzevii infections.
Assuntos
Monoterpenos Acíclicos , Antifúngicos , Apoptose , Cimenos , Sinergismo Farmacológico , Testes de Sensibilidade Microbiana , Monoterpenos , Nistatina , Pichia , Antifúngicos/farmacologia , Cimenos/farmacologia , Monoterpenos Acíclicos/farmacologia , Nistatina/farmacologia , Apoptose/efeitos dos fármacos , Humanos , Monoterpenos/farmacologia , Pichia/efeitos dos fármacos , Pichia/isolamento & purificaçãoRESUMO
There is growing interest in designing multidrug therapies that leverage tradeoffs to combat resistance. Tradeoffs are common in evolution and occur when, for example, resistance to one drug results in sensitivity to another. Major questions remain about the extent to which tradeoffs are reliable, specifically, whether the mutants that provide resistance to a given drug all suffer similar tradeoffs. This question is difficult because the drug-resistant mutants observed in the clinic, and even those evolved in controlled laboratory settings, are often biased towards those that provide large fitness benefits. Thus, the mutations (and mechanisms) that provide drug resistance may be more diverse than current data suggests. Here, we perform evolution experiments utilizing lineage-tracking to capture a fuller spectrum of mutations that give yeast cells a fitness advantage in fluconazole, a common antifungal drug. We then quantify fitness tradeoffs for each of 774 evolved mutants across 12 environments, finding these mutants group into classes with characteristically different tradeoffs. Their unique tradeoffs may imply that each group of mutants affects fitness through different underlying mechanisms. Some of the groupings we find are surprising. For example, we find some mutants that resist single drugs do not resist their combination, while others do. And some mutants to the same gene have different tradeoffs than others. These findings, on one hand, demonstrate the difficulty in relying on consistent or intuitive tradeoffs when designing multidrug treatments. On the other hand, by demonstrating that hundreds of adaptive mutations can be reduced to a few groups with characteristic tradeoffs, our findings may yet empower multidrug strategies that leverage tradeoffs to combat resistance. More generally speaking, by grouping mutants that likely affect fitness through similar underlying mechanisms, our work guides efforts to map the phenotypic effects of mutation.
Mutations in an organism's DNA make the individual more likely to survive and reproduce in its environment, passing on its mutations to the next generation. Mutations can alter the proteins that a gene codes for in many ways. This leads to a situation where seemingly similar mutations such as two mutations in the same gene can have different effects. For example, two different mutations could affect the primary function of the encoded protein in the same way but have different side effects. One mutation might also cause the protein to interact with a new molecule or protein. Organisms possessing one or the other mutation will thus have similar odds of surviving and reproducing in some environments, but differences in environments where the new interaction is important. In microorganisms, mutations can lead to drug resistance. If drug-resistant mutations have different side effects, it can be challenging to treat microbial infections, as drug-resistant pathogens are often treated with sequential drug strategies. These strategies rely on mutations that cause resistance to the first drug all having susceptibility to the second drug. But if similar seeming mutations can have diverse side effects, predictions about how they will respond to a second drug are more complicated. To address this issue, Schmidlin, Apodaca et al. collected a diverse group of nearly a thousand mutant yeast strains that were resistant to a drug called fluconazole. Next, they asked to what extent the fitness the ability to survive and reproduce of these mutants responded similarly to environmental change. They used this information to cluster mutations into groups that likely have similar effects at the molecular level, finding at least six such groups with unique trade-offs across environments. For example, some groups resisted only low drug concentrations, and others were unique in that they resisted treatment with two single drugs but not their combination. These diverse types of fluconazole-resistant yeast lineages highlight the challenges of designing a simple sequential drug treatment that targets all drug-resistant mutants. However, the results also suggest some predictability in how drug-resistant infections can evolve and be treated.
Assuntos
Antifúngicos , Farmacorresistência Fúngica , Fluconazol , Aptidão Genética , Mutação , Saccharomyces cerevisiae , Fluconazol/farmacologia , Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/efeitos dos fármacos , Antifúngicos/farmacologia , Farmacorresistência Fúngica/genéticaAssuntos
Antifúngicos , Aspergillus fumigatus , Azóis , Farmacorresistência Fúngica , Aspergillus fumigatus/efeitos dos fármacos , Aspergillus fumigatus/isolamento & purificação , Humanos , Dinamarca/epidemiologia , Azóis/farmacologia , Azóis/uso terapêutico , Antifúngicos/uso terapêutico , Antifúngicos/farmacologia , Aspergilose/microbiologia , Aspergilose/epidemiologia , Aspergilose/tratamento farmacológicoRESUMO
In Candida albicans, Cdr1 pumps azole drugs out of the cells to reduce intracellular accumulation at detrimental concentrations, leading to azole-drug resistance. Milbemycin oxime, a veterinary anti-parasitic drug, strongly and specifically inhibits Cdr1. However, how Cdr1 recognizes and exports azole drugs, and how milbemycin oxime inhibits Cdr1 remain unclear. Here, we report three cryo-EM structures of Cdr1 in distinct states: the apo state (Cdr1Apo), fluconazole-bound state (Cdr1Flu), and milbemycin oxime-inhibited state (Cdr1Mil). Both the fluconazole substrate and the milbemycin oxime inhibitor are primarily recognized within the central cavity of Cdr1 through hydrophobic interactions. The fluconazole is suggested to be exported from the binding site into the environment through a lateral pathway driven by TM2, TM5, TM8 and TM11. Our findings uncover the inhibitory mechanism of milbemycin oxime, which inhibits Cdr1 through competition, hindering export, and obstructing substrate entry. These discoveries advance our understanding of Cdr1-mediated azole resistance in C. albicans and provide the foundation for the development of innovative antifungal drugs targeting Cdr1 to combat azole-drug resistance.
Assuntos
Antifúngicos , Azóis , Candida albicans , Microscopia Crioeletrônica , Proteínas Fúngicas , Proteínas de Membrana Transportadoras , Candida albicans/efeitos dos fármacos , Candida albicans/metabolismo , Proteínas Fúngicas/metabolismo , Proteínas Fúngicas/química , Proteínas Fúngicas/antagonistas & inibidores , Antifúngicos/farmacologia , Antifúngicos/química , Azóis/farmacologia , Azóis/química , Proteínas de Membrana Transportadoras/metabolismo , Proteínas de Membrana Transportadoras/química , Proteínas de Membrana Transportadoras/ultraestrutura , Farmacorresistência Fúngica , Fluconazol/farmacologia , Sítios de LigaçãoRESUMO
Caspofungin, a lipopeptide, is an antifungal drug that belong to the class of echinocandin. It inhibits fungal cell wall ß-(1,3)-glucan synthase activity and is the second-line of drug for invasive aspergillosis, a fatal infection caused mainly by Aspergillus fumigatus. On the other hand, Enfumafungin is a natural triterpene glycoside also with a ß-(1,3)-glucan synthase inhibitory activity and reported to have antifungal potential. In the present study, we compared the growth as well as modifications in the A. fumigatus cell wall upon treatment with Caspofungin or Enfumafungin, consequentially their immunomodulatory capacity on human dendritic cells. Caspofungin initially inhibited the growth of A. fumigatus, but the effect was lost over time. By contrast, Enfumafungin inhibited this fungal growth for the duration investigated. Both Caspofungin and Enfumafungin caused a decrease in the cell wall ß-(1,3)-glucan content with a compensatory increase in the chitin, and to a minor extent they also affected cell wall galactose content. Treatment with these two antifungals did not result in the exposure of ß-(1,3)-glucan on A. fumigatus mycelial surface. Enzymatic digestion suggested a modification of ß-(1,3)-glucan structure, specifically its branching, upon Enfumafungin treatment. While there was no difference in the immunostimulatory capacity of antifungal treated A. fumigatus conidia, alkali soluble-fractions from Caspofungin treated mycelia weakly stimulated the dendritic cells, possibly due to an increased content of immunosuppressive polysaccharide galactosaminogalactan. Overall, we demonstrate a novel mechanism that Enfumafungin not only inhibits ß-(1,3)-glucan synthase activity, but also causes modifications in the structure of ß-(1,3)-glucan in the A. fumigatus cell wall.
Assuntos
Antifúngicos , Aspergillus fumigatus , Caspofungina , Parede Celular , Células Dendríticas , Equinocandinas , Glucosiltransferases , Aspergillus fumigatus/efeitos dos fármacos , Aspergillus fumigatus/enzimologia , Humanos , Parede Celular/efeitos dos fármacos , Células Dendríticas/efeitos dos fármacos , Antifúngicos/farmacologia , Equinocandinas/farmacologia , Caspofungina/farmacologia , Glucosiltransferases/antagonistas & inibidores , Glucosiltransferases/metabolismo , beta-Glucanas/farmacologia , Lipopeptídeos/farmacologia , Células Cultivadas , Quitina/farmacologia , Glicosídeos , TriterpenosRESUMO
Invasive fungal infections are associated with high mortality, which is exacerbated by the limited antifungal drug armamentarium and increasing antifungal drug resistance. Echinocandins are a frontline antifungal drug class targeting ß-glucan synthase (GS), a fungal cell wall biosynthetic enzyme. Echinocandin resistance is generally low but increasing in species like Candida glabrata, an opportunistic yeast pathogen colonizing human mucosal surfaces. Mutations in GS-encoding genes (FKS1 and FKS2 in C. glabrata) are strongly associated with clinical echinocandin failure, but epidemiological studies show that other, as yet unidentified factors also influence echinocandin susceptibility. Furthermore, although the gut is known to be an important reservoir for emergence of drug-resistant strains, the evolution of resistance is not well understood. Here, we studied the evolutionary dynamics of C. glabrata colonizing the gut of immunocompetent mice during treatment with caspofungin, a widely-used echinocandin. Whole genome and amplicon sequencing revealed rapid genetic diversification of this C. glabrata population during treatment and the emergence of both drug target (FKS2) and non-drug target mutations, the latter predominantly in the FEN1 gene encoding a fatty acid elongase functioning in sphingolipid biosynthesis. The fen1 mutants displayed high fitness in the gut specifically during caspofungin treatment and contained high levels of phytosphingosine, whereas genetic depletion of phytosphingosine by deletion of YPC1 gene hypersensitized the wild type strain to caspofungin and was epistatic to fen1Δ. Furthermore, high resolution imaging and mass spectrometry showed that reduced caspofungin susceptibility in fen1Δ cells was associated with reduced caspofungin binding to the plasma membrane. Finally, we identified several different fen1 mutations in clinical C. glabrata isolates, which phenocopied the fen1Δ mutant, causing reduced caspofungin susceptibility. These studies reveal new genetic and molecular determinants of clinical caspofungin susceptibility and illuminate the dynamic evolution of drug target and non-drug target mutations reducing echinocandin efficacy in patients colonized with C. glabrata.
Assuntos
Antifúngicos , Candida glabrata , Candidíase , Caspofungina , Farmacorresistência Fúngica , Mutação , Esfingolipídeos , Candida glabrata/genética , Candida glabrata/efeitos dos fármacos , Candida glabrata/metabolismo , Caspofungina/farmacologia , Camundongos , Antifúngicos/farmacologia , Animais , Esfingolipídeos/biossíntese , Esfingolipídeos/metabolismo , Farmacorresistência Fúngica/genética , Candidíase/tratamento farmacológico , Candidíase/microbiologia , Proteínas Fúngicas/genética , Proteínas Fúngicas/metabolismo , Glucosiltransferases/genética , Glucosiltransferases/metabolismo , Testes de Sensibilidade Microbiana , Equinocandinas/farmacologia , HumanosRESUMO
Fungi play critical roles in the homeostasis of ecosystems globally and have emerged as significant causes of an expanding repertoire of devastating diseases in plants, animals, and humans. In this Commentary, we highlight the importance of fungal pathogens and argue for concerted research efforts to enhance understanding of fungal virulence, antifungal immunity, novel drug targets, antifungal resistance, and the mycobiota to improve human health.
Assuntos
Fungos , Micoses , Fungos/patogenicidade , Humanos , Micoses/microbiologia , Micoses/imunologia , Animais , Farmacorresistência Fúngica , Antifúngicos/farmacologia , VirulênciaRESUMO
BACKGROUND: Terbinafine is widely used to treat onychomycosis caused by dermatophyte fungi. Terbinafine resistance in recent years is causing concern. Resistance has so far been associated with single-nucleotide substitutions in the DNA sequence of the enzyme squalene epoxidase (SQLE) but how this affects SQLE functionality is not understood. OBJECTIVES: The aim of this study was to understand newly discovered resistance in two Australian strains of Trichophyton interdigitale. PATIENTS/METHODS: Resistance to terbinafine was tested in four newly isolated strains. Three-dimensional SQLE models were prepared to investigate how the structure of their SQLE affected the binding of terbinafine. RESULTS: This study found the first Australian occurrences of terbinafine resistance in two T. interdigitale strains. Both strains had novel deletion mutations in erg1 and frameshifts during translation. Three-dimensional models had smaller SQLE proteins and open reading frames as well as fewer C-terminal α-helices than susceptible strains. In susceptible strains, the lipophilic tail of terbinafine was predicted to dock stably into a hydrophobic pocket in SQLE lined by over 20 hydrophobic amino acids. In resistant strains, molecular dynamics simulations showed that terbinafine docking was unstable and so terbinafine did not block squalene metabolism and ultimately ergosterol production. The resistant reference strain ATCC MYA-4438 T. rubrum showed a single erg1 mutation that resulted in frameshift during translation, leading to C-terminal helix deletion. CONCLUSIONS: Modelling their effects on their SQLE proteins will aid in the design of potential new treatments for these novel resistant strains, which pose clinical problems in treating dermatophyte infections with terbinafine.
Assuntos
Antifúngicos , Arthrodermataceae , Farmacorresistência Fúngica , Esqualeno Mono-Oxigenase , Terbinafina , Terbinafina/farmacologia , Esqualeno Mono-Oxigenase/genética , Esqualeno Mono-Oxigenase/metabolismo , Farmacorresistência Fúngica/genética , Austrália , Antifúngicos/farmacologia , Humanos , Arthrodermataceae/efeitos dos fármacos , Arthrodermataceae/genética , Arthrodermataceae/enzimologia , Testes de Sensibilidade Microbiana , Onicomicose/microbiologia , Onicomicose/tratamento farmacológico , Proteínas Fúngicas/genética , Proteínas Fúngicas/metabolismo , Modelos MolecularesRESUMO
This study aimed to evaluate the genomic profile of the Antarctic marine Curtobacterium sp. CBMAI 2942, as well as to optimize the conditions for chitinase production and antifungal potential for biological control. Assembly and annotation of the genome confirmed the genomic potential for chitinase synthesis, revealing two ChBDs of chitin binding (Chi C). The optimization enzyme production using an experimental design resulted in a 3.7-fold increase in chitinase production. The chitinase enzyme was identified by SDS-PAGE and confirmed through mass spectrometry analysis. The enzymatic extract obtained using acetone showed antifungal activity against the phytopathogenic fungus Aspergillus sp. series Nigri CBMAI 1846. The genetic capability of Curtobacterium sp. CBMAI 2942 for chitin degradation was confirmed through genomic analysis. The basal culture medium was adjusted, and the chitinase produced by this isolate from Antarctica showed significant inhibition against Aspergillus sp. Nigri series CBMAI 1846, which is a tomato phytopathogenic fungus. This suggests that this marine bacterium could potentially be used as a biological control of agricultural pests.
Assuntos
Antifúngicos , Quitinases , Proteômica , Quitinases/metabolismo , Quitinases/genética , Quitinases/farmacologia , Antifúngicos/farmacologia , Regiões Antárticas , Proteômica/métodos , Genômica/métodos , Aspergillus/enzimologia , Aspergillus/genética , Genoma Bacteriano , Proteínas de Bactérias/metabolismo , Proteínas de Bactérias/genética , Organismos Aquáticos , Quitina/farmacologia , Quitina/metabolismo , Quitina/químicaRESUMO
Candida albicans invasive candidiasis is considered a global health problem. In such cases, biofilm formation on implanted devices represents a therapeutic challenge and the presence of metabolically inactive persistent cells (PCs) in these communities increases their tolerance to fungicidal drugs. This study investigated the influence of amoxicillin, AMX; cefepime, CEF; gentamicin, GEN; amikacin, AMK; vancomycin, VAN; and ciprofloxacin, CIP; on the production of PCs in biofilms of C. albicans bloodstream isolates. 48 h-mature biofilms (n = 6) grown in RPMI-1640 supplemented with antibiotics were treated with 100 µg ml-1 amphotericin B and then evaluated for PCs. Biofilms grown in the presence of antibiotics produced more PCs, up to 10×, when exposed to AMX and CIP; 5 × to CEF; and 6 × to GEN and VAN. The results indicate that antibiotics can modulate PC production in C. albicans biofilms. This scenario may have clinical repercussions in immunocompromised patients under broad-spectrum antibiotic therapy.
Biofilms are microbial communities tolerant to antifungals. Our research showed that antibiotics stimulate the formation of persistent cells within Candida albicans biofilms. These are dormant, metabolically silent cells that resist to therapy and can be related to metastatic and recalcitrant infections.
Assuntos
Antibacterianos , Biofilmes , Candida albicans , Biofilmes/efeitos dos fármacos , Biofilmes/crescimento & desenvolvimento , Candida albicans/efeitos dos fármacos , Candida albicans/fisiologia , Antibacterianos/farmacologia , Humanos , Antifúngicos/farmacologia , Testes de Sensibilidade Microbiana , Ciprofloxacina/farmacologia , Gentamicinas/farmacologia , Amoxicilina/farmacologia , Vancomicina/farmacologia , Amicacina/farmacologia , Cefepima/farmacologia , Anfotericina B/farmacologia , Cefalosporinas/farmacologia , Candidíase/microbiologia , Candidíase/tratamento farmacológicoRESUMO
Candida auris is a multidrug-resistant yeast that has seen a worrying increase during the COVID-19 pandemic. Give7/n this, new therapeutic options, such as controlled-release nanomaterials, may be promising in combating the infection. Therefore, this study aimed to develop amphotericin B (AmB) and micafungin (MICA)-loaded nanoemulsions (NEMA) and evaluated against biofilms of C. auris. Nanoemulsions (NEs) were characterized and determined minimum inhibitory concentration MIC90, checkerboard and anti-biofilm. NEMA presented a size of 53.7 and 81.4 nm for DLS and NTA, respectively, with good stability and spherical morphology. MICAmB incorporated efficiency was 88.4 and 99.3%, respectively. The release results show that AmB and MICA obtained a release of 100 and 63.4%, respectively. MICAmB and NEMA showed MIC90 values of 0.015 and 0.031 ug/mL, respectively and synergism. NEMA showed greater metabolic inhibition and morphological changes in mature biofilms. This drugs combination and co-encapsulation proved to be a promising therapy against C. auris biofilms.
Assuntos
Anfotericina B , Antifúngicos , Biofilmes , Candida auris , Emulsões , Micafungina , Testes de Sensibilidade Microbiana , Biofilmes/efeitos dos fármacos , Antifúngicos/farmacologia , Antifúngicos/química , Antifúngicos/administração & dosagem , Anfotericina B/farmacologia , Anfotericina B/administração & dosagem , Anfotericina B/química , Micafungina/farmacologia , Micafungina/administração & dosagem , Emulsões/farmacologia , Emulsões/química , Candida auris/efeitos dos fármacos , Humanos , SARS-CoV-2/efeitos dos fármacos , COVID-19 , Nanopartículas/químicaAssuntos
Basidiomycota , Tricosporonose , Infecções Urinárias , Humanos , Antifúngicos/farmacologia , Antifúngicos/uso terapêutico , Basidiomycota/efeitos dos fármacos , Basidiomycota/isolamento & purificação , Tricosporonose/diagnóstico , Tricosporonose/tratamento farmacológico , Tricosporonose/microbiologia , Sistema Urinário/microbiologia , Infecções Urinárias/diagnóstico , Infecções Urinárias/tratamento farmacológico , Infecções Urinárias/microbiologiaRESUMO
BACKGROUND: Vulvovaginitis is common in women of reproductive age group characterized by purulent white discharge. The incidence of vulvovaginitis has risen recently due to the resistance of Candida species to commonly used antifungal agents and recurrent infections. OBJECTIVE: The study aimed to determine the prevalence, associated factors, and antifungal susceptibility patterns of vaginal candidiasis among pregnant women attending Bule Hora University Teaching Hospital. METHODS: A hospital-based cross-sectional study was conducted from May 2023 to August 2023. Using systematic random sampling, 317 pregnant women participated in the study. Sabouraud Dextrose Agar and Chromogenic Candida Differential Agar were used to isolate and identify Candida species from clinical samples. Antifungal susceptibility was performed using a modified disc diffusion method. Epi data version 4.6 was used for data entry and Statistical Packages for Social Sciences version 25 was used for statistical analysis. A P-value < 0.05 was declared statistically significant. RESULT: The prevalence of vaginal candidiasis was 26.8% (95%, CI 21.9-31.72%). History of using contraceptives (AOR = 5.03, 95%CI, 1.21-11.37), past vaginal candidiasis (AOR = 6, 95%CI, 1.61-12.92), pregnant women infected with human immunodeficiency virus (HIV) (AOR = 4.24, 95%CI, 1.23-14.14), diabetic mellitus (AOR = 2.17, 95%CI, 1.02-4.64), history of antibiotic use (AOR = 3.55, 95%CI, 1.67-12.75), pregnant women in third trimester (AOR = 8.72, 95%CI, 1.30-23.07), were the significantly associated factors for vaginal candidiasis. The study revealed that itraconazole, amphotericin B, and miconazole were the most effective antifungal drugs for all Candida isolates. CONCLUSION: The present study has identified a high prevalence of vaginal candidiasis among pregnant women. The isolated Candida species showed resistance to fluconazole, ketoconazole, and clotrimazole. Therefore, healthcare providers should increase awareness of the risks of Candida infections to reduce Candida species among pregnant women. Physicians should prescribe suitable medications based on antifungal drug test outcomes to treat pregnant women with vaginal candidiasis.
Assuntos
Antifúngicos , Candida , Candidíase Vulvovaginal , Hospitais de Ensino , Humanos , Feminino , Candidíase Vulvovaginal/epidemiologia , Candidíase Vulvovaginal/tratamento farmacológico , Candidíase Vulvovaginal/microbiologia , Gravidez , Etiópia/epidemiologia , Adulto , Prevalência , Estudos Transversais , Antifúngicos/uso terapêutico , Antifúngicos/farmacologia , Adulto Jovem , Candida/efeitos dos fármacos , Candida/isolamento & purificação , Testes de Sensibilidade Microbiana , Cuidado Pré-Natal , Complicações Infecciosas na Gravidez/epidemiologia , Complicações Infecciosas na Gravidez/microbiologia , Complicações Infecciosas na Gravidez/tratamento farmacológico , Fatores de Risco , Farmacorresistência Fúngica , Adolescente , Miconazol/uso terapêutico , Miconazol/farmacologiaRESUMO
Reptiles in the wild or as pets may act as spreaders of bacteria, viruses, fungi and parasites. However, studies on the mycobiota of these animals are scanty. This study investigates the occurrence of yeasts from the cloacal swabs of snakes of different origins and the antifungal profile of the isolated strains. A total of 180 cloacal samples of snakes were collected from Morocco (Group I: n = 68) and Italy (Group II: n = 112). Yeast species were biochemically and molecularly identified. A total of 72 yeast strains belonging to 13 genera, 8 from snakes in Group I and five from snakes in Group II were identified. The most frequently isolated species were Trichosporon asahii (22.2%) and Candida tropicalis (15.3%) from snakes in Group I and Debaryomyces spp. (16.7%) and Metahyphopichia silvanorum (11.1%) from snakes in Group II. Multiple azole and amphotericin B (AmB) resistance phenomena were detected among isolated yeasts. Azole multi drug resistance phenomena were detected among yeasts from Group I and Rhodotorula mucilaginosa from Group II, whereas AmB resistance phenomena among those from Group II. Data suggest that snakes may harbor pathogenetic yeasts, being potential reservoirs and spreaders of these organisms in the environment. Since the yeast species community from different groups of animals as well as their antifungal profile reflects the epidemiology of human yeast infections in the same geographical areas, the results indicate that snakes may be considered as sentinels for human/animal pathogenic microorganisms and bio-indicators of environmental quality.