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1.
Life Sci Alliance ; 7(7)2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38719750

RESUMO

Celiac disease (CD) is an autoimmune enteropathy resulting from an interaction between diet, genome, and immunity. Although many patients respond to a gluten-free diet, in a substantive number of individuals, the intestinal injury persists. Thus, other factors might amplify the ongoing inflammation. Candida albicans is a commensal fungus that is well adapted to the intestinal life. However, specific conditions increase Candida pathogenicity. The hypothesis that Candida may be a trigger in CD has been proposed after the observation of similarity between a fungal wall component and two CD-related gliadin T-cell epitopes. However, despite being implicated in intestinal disorders, Candida may also protect against immune pathologies highlighting a more intriguing role in the gut. Herein, we postulated that a state of chronic inflammation associated with microbial dysbiosis and leaky gut are favorable conditions that promote C. albicans pathogenicity eventually contributing to CD pathology via a mast cells (MC)-IL-9 axis. However, the restoration of immune and microbial homeostasis promotes a beneficial C. albicans-MC cross-talk favoring the attenuation of CD pathology to alleviate CD pathology and symptoms.


Assuntos
Candida albicans , Doença Celíaca , Homeostase , Mastócitos , Doença Celíaca/imunologia , Doença Celíaca/microbiologia , Doença Celíaca/metabolismo , Humanos , Candida albicans/patogenicidade , Candida albicans/imunologia , Mastócitos/imunologia , Mastócitos/metabolismo , Microbioma Gastrointestinal/imunologia , Disbiose/imunologia , Candidíase/imunologia , Candidíase/microbiologia , Animais , Candida/patogenicidade , Candida/imunologia , Mucosa Intestinal/microbiologia , Mucosa Intestinal/imunologia , Mucosa Intestinal/metabolismo
2.
PLoS One ; 19(5): e0303373, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38728271

RESUMO

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


Assuntos
Antifúngicos , Candida , Testes de Sensibilidade Microbiana , Quinoxalinas , Antifúngicos/farmacologia , Antifúngicos/química , Quinoxalinas/farmacologia , Quinoxalinas/química , Animais , Candida/efeitos dos fármacos , Camundongos , Modelos Animais de Doenças , Candidíase/tratamento farmacológico , Candidíase/microbiologia , Feminino
3.
Int J Mol Sci ; 25(9)2024 Apr 27.
Artigo em Inglês | MEDLINE | ID: mdl-38731993

RESUMO

Extracellular proteases are key factors contributing to the virulence of pathogenic fungi from the genus Candida. Their proteolytic activities are crucial for extracting nutrients from the external environment, degrading host defenses, and destabilizing the internal balance of the human organism. Currently, the enzymes most frequently described in this context are secreted aspartic proteases (Saps). This review comprehensively explores the multifaceted roles of Saps, highlighting their importance in biofilm formation, tissue invasion through the degradation of extracellular matrix proteins and components of the coagulation cascade, modulation of host immune responses via impairment of neutrophil and monocyte/macrophage functions, and their contribution to antifungal resistance. Additionally, the diagnostic challenges associated with Candida infections and the potential of Saps as biomarkers were discussed. Furthermore, we examined the prospects of developing vaccines based on Saps and the use of protease inhibitors as adjunctive therapies for candidiasis. Given the complex biology of Saps and their central role in Candida pathogenicity, a multidisciplinary approach may pave the way for innovative diagnostic strategies and open new opportunities for innovative clinical interventions against candidiasis.


Assuntos
Ácido Aspártico Proteases , Candidíase , Interações Hospedeiro-Patógeno , Humanos , Ácido Aspártico Proteases/metabolismo , Candidíase/microbiologia , Candida/patogenicidade , Candida/enzimologia , Biofilmes/crescimento & desenvolvimento , Animais , Proteínas Fúngicas/metabolismo
4.
Arch Microbiol ; 206(6): 255, 2024 May 11.
Artigo em Inglês | MEDLINE | ID: mdl-38734793

RESUMO

Cystic fibrosis (CF) is an inherited disease that results from mutations in the gene responsible for the cystic fibrosis transmembrane conductance regulator (CFTR). The airways become clogged with thick, viscous mucus that traps microbes in respiratory tracts, facilitating colonization, inflammation and infection. CF is recognized as a biofilm-associated disease, it is commonly polymicrobial and can develop in biofilms. This review discusses Candida spp. and both Gram-positive and Gram-negative bacterial biofilms that affect the airways and cause pulmonary infections in the CF context, with a particular focus on mixed-species biofilms. In addition, the review explores the intricate interactions between fungal and bacterial species within these biofilms and elucidates the underlying molecular mechanisms that govern their dynamics. Moreover, the review addresses the multifaceted issue of antimicrobial resistance in the context of CF-associated biofilms. By synthesizing current knowledge and research findings, this review aims to provide insights into the pathogenesis of CF-related infections and identify potential therapeutic approaches to manage and combat these complex biofilm-mediated infections.


Assuntos
Biofilmes , Candida , Fibrose Cística , Biofilmes/crescimento & desenvolvimento , Fibrose Cística/microbiologia , Humanos , Candida/fisiologia , Candida/genética , Candidíase/microbiologia , Bactérias Gram-Negativas/fisiologia , Bactérias Gram-Negativas/genética , Antibacterianos/farmacologia
6.
Front Cell Infect Microbiol ; 14: 1322847, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38707513

RESUMO

The aetiology of chronic aseptic meningitis is difficult to establish. Candida meningitis in particular is often diagnosed late, as cerebrospinal fluid (CSF) work-up and imaging findings are nonspecific. A 35-year-old patient with chronic aseptic meningitis, for which repeated microbiological testing of CSF was unrevealing, was finally diagnosed with Candida albicans (C. albicans) meningitis with cauda equina involvement using metagenomic next-generation sequencing (mNGS). This report highlights the diagnostic challenges and the difficulties of treating shunt-associated fungal meningitis.


Assuntos
Candida albicans , Sequenciamento de Nucleotídeos em Larga Escala , Meningite Fúngica , Metagenômica , Humanos , Adulto , Candida albicans/genética , Candida albicans/isolamento & purificação , Meningite Fúngica/diagnóstico , Meningite Fúngica/microbiologia , Meningite Fúngica/tratamento farmacológico , Metagenômica/métodos , Candidíase/diagnóstico , Candidíase/microbiologia , Candidíase/líquido cefalorraquidiano , Masculino , Doença Crônica , Antifúngicos/uso terapêutico , Meningite Asséptica/diagnóstico
7.
Front Cell Infect Microbiol ; 14: 1295841, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38707510

RESUMO

Introduction: Although the existence of Candida species in the respiratory tract is often considered commensal, it is crucial to recognize the significance of Candida colonization in immunocompromised or COVID-19 patients. The emergence of Candida auris as an emerging pathogen further emphasizes the importance of monitoring yeast infection/colonization, particularly in COVID-19 patients. Methods: In this study, respiratory samples mainly from COVID-19 patients, primarily those suspected of having a fungal infection, were cultured on Sabouraud dextrose agar plates and the yeast colonies were identified using a two-step multiplex PCR method. The samples suspected of C. auris underwent specific nested PCR followed by sequence analysis. Results: A total of 199 respiratory samples were collected from 73 women and 126 men, ranging in age from 1.6 to 88 years. Among the patients, 141 had COVID-19, 32 had cancer, 5 were hospitalized in ICU, 2 had chronic obstructive pulmonary disease)COPD(, and others were patients with combination diseases. From these samples, a total of 334 yeast strains were identified. C. albicans (n=132, 39.52%) was the most common species, followed by C. tropicalis (n=67, 20%), C. glabrata (n=56, 16.76%), C. krusei (n=18, 5.4%), C. parapsilosis (n=17, 5.08%), Saccharomyces cerevisiae (n=10, 3%), C. kefyr (n=9, 2.6%), C. dubliniensis (n=7, 2.1%), C. lusitaniae (n=5, 1.5%), C. auris (n=3, 0.9%), C. guilliermondii (n=2, 0.6%), C. rugosa (n=1, 0.3%), C. intermedia (n=1, 0.3%), and Trichosporon spp. (n=1, 0.3%). C. auris was detected in a patient in ICU and two COVID-19 patients. While its presence was confirmed through sequence analysis, our extensive efforts to isolate C. auris were unsuccessful. Conclusion: While C. albicans colonization remains prevalent, our study found no evidence of Candida lung infection. Since the role of Candida colonization in airway secretions remains ambiguous due to limited research, further studies are imperative to shed light on this matter.


Assuntos
COVID-19 , Candida auris , Candidíase , SARS-CoV-2 , Humanos , COVID-19/microbiologia , Idoso , Pessoa de Meia-Idade , Feminino , Masculino , Idoso de 80 Anos ou mais , Adulto , Pré-Escolar , Candidíase/microbiologia , Criança , Adolescente , Adulto Jovem , SARS-CoV-2/genética , SARS-CoV-2/isolamento & purificação , Lactente , Candida auris/genética , Candida auris/isolamento & purificação , Candida/isolamento & purificação , Candida/classificação , Candida/genética , Sistema Respiratório/microbiologia , Sistema Respiratório/virologia , Reação em Cadeia da Polimerase Multiplex
8.
Mycopathologia ; 189(3): 40, 2024 May 05.
Artigo em Inglês | MEDLINE | ID: mdl-38704798

RESUMO

Candida parapsilosis complex has recently received special attention due to naturally occurring FKS1 polymorphism associated with high minimal inhibitory concentrations for echinocandin and the increase of clonal outbreaks of strains resistant to commonly used antifungals such as fluconazole. Despite the previous fact, little is known about the genetic mechanism associated with echinocandin resistance. Therefore, the present study was designed to investigate the mechanism of acquired echinocandin resistance in C. parapsilosis complex strains. A total of 15 clinical C. parapsilosis complex isolates were sub-cultured for 30 days at a low concentration of micafungin at ½ the lowest MIC value of the tested isolates (0.12 µg/ml). After culturing, all the isolates were checked phenotypically for antifungal resistance and genotypically for echinocandin resistance by checking FKS1 gene hot spot one (HS1) and HS2 mutations. In vitro induction of echinocandin resistance confirmed the rapid development of resistance at low concentration micafungin, with no difference among C. parapsilosis, C. metapsilosis, and C. orthopsilosis in the resistance development. For the first time we identified different FKS1 HS1 and or HS2 mutations responsible for echinocandin resistance such as R658S and L1376F in C. parapsilosis, S656X, R658X, R658T, W1370X, X1371I, V1371X, and R1373X (corresponding to their location in C. parapsilosis) in C. metapsilosis, and L648F and R1366H in C. orthopsilosis. Our results are of significant concern, since the rapid development of resistance may occur clinically after short-term exposure to antifungals as recently described in other fungal species with the potential of untreatable infections.


Assuntos
Antifúngicos , Candida parapsilosis , Farmacorresistência Fúngica , Equinocandinas , Testes de Sensibilidade Microbiana , Farmacorresistência Fúngica/genética , Antifúngicos/farmacologia , Equinocandinas/farmacologia , Humanos , Candida parapsilosis/genética , Candida parapsilosis/efeitos dos fármacos , Candidíase/microbiologia , Proteínas Fúngicas/genética , Glucosiltransferases/genética , Mutação de Sentido Incorreto , Micafungina/farmacologia , Mutação
9.
J Med Microbiol ; 73(5)2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38743468

RESUMO

Introduction. Innovative antifungal therapies are of crucial importance to combat the potentially life-threatening infections linked to the multidrug-resistant fungal pathogen Candida auris. Induction of regulated cell death, apoptosis, could provide an outline for future therapeutics. Human antimicrobial peptides (AMPs), well-known antifungal compounds, have shown the ability to induce apoptosis in pathogenic fungi.Hypothesis/Gap Statement . Although it is known that AMPs possess antifungal activity against C. auris, their ability to induce apoptosis requires further investigations.Aim. This study evaluated the effects of AMPs on the induction of apoptosis in C. auris.Methods. Human neutrophil peptide-1 (HNP-1), human ß-Defensins-3 (hBD-3) and human salivary histatin 5 (His 5) were assessed against two clinical C. auris isolates. Apoptosis hallmarks were examined using FITC-Annexin V/PI double labelling assay and terminal deoxynucleotidyl transferase deoxynucleotidyl transferase nick-end labelling (TUNEL) to detect phosphatidylserine externalization and DNA fragmentation, respectively. Then, several intracellular triggers were studied using JC-10 staining, spectrophotometric assay and 2',7'-dichlorofluorescin diacetate staining to measure the mitochondrial membrane potential, cytochrome-c release and reactive oxygen species (ROS) production, respectively.Results and conclusion. FITC-Annexin V/PI staining and TUNEL analysis revealed that exposure of C. auris cells to HNP-1 and hBD-3 triggered both early and late apoptosis, while His 5 caused significant necrosis. Furthermore, HNP-1 and hBD-3 induced significant mitochondrial membrane depolarization, which resulted in substantial cytochrome c release. In contrast to His 5, which showed minimal mitochondrial depolarization and no cytochrome c release. At last, all peptides significantly increased ROS production, which is related to both types of cell death. Therefore, these peptides represent promising and effective antifungal agents for treating invasive infections caused by multidrug-resistant C. auris.


Assuntos
Antifúngicos , Apoptose , Candida auris , Histatinas , Espécies Reativas de Oxigênio , Apoptose/efeitos dos fármacos , Humanos , Antifúngicos/farmacologia , Histatinas/farmacologia , Espécies Reativas de Oxigênio/metabolismo , Candida auris/efeitos dos fármacos , beta-Defensinas/farmacologia , Potencial da Membrana Mitocondrial/efeitos dos fármacos , alfa-Defensinas/farmacologia , Testes de Sensibilidade Microbiana , Peptídeos Antimicrobianos/farmacologia , Peptídeos Antimicrobianos/química , Citocromos c/metabolismo , Fragmentação do DNA/efeitos dos fármacos , Candidíase/tratamento farmacológico , Candidíase/microbiologia
10.
Nat Commun ; 15(1): 3926, 2024 May 09.
Artigo em Inglês | MEDLINE | ID: mdl-38724513

RESUMO

Patients with decreased levels of CD18 (ß2 integrins) suffer from life-threatening bacterial and fungal infections. CD11b, the α subunit of integrin CR3 (CD11b/CD18, αMß2), is essential for mice to fight against systemic Candida albicans infections. Live elongating C. albicans activates CR3 in immune cells. However, the hyphal ligands that activate CR3 are not well defined. Here, we discovered that the C. albicans Als family proteins are recognized by the I domain of CD11b in macrophages. This recognition synergizes with the ß-glucan-bound lectin-like domain to activate CR3, thereby promoting Syk signaling and inflammasome activation. Dectin-2 activation serves as the "outside-in signaling" for CR3 activation at the entry site of incompletely sealed phagosomes, where a thick cuff of F-actin forms to strengthen the local interaction. In vitro, CD18 partially contributes to IL-1ß release from dendritic cells induced by purified hyphal Als3. In vivo, Als3 is vital for C. albicans clearance in mouse kidneys. These findings uncover a novel family of ligands for the CR3 I domain that promotes fungal clearance.


Assuntos
Antígenos CD18 , Candidíase , Proteínas Fúngicas , Lectinas Tipo C , Macrófagos , Animais , Camundongos , beta-Glucanas/metabolismo , beta-Glucanas/imunologia , Candida albicans/imunologia , Candidíase/imunologia , Candidíase/microbiologia , Antígeno CD11b/metabolismo , Antígeno CD11b/imunologia , Antígenos CD18/metabolismo , Células Dendríticas/imunologia , Células Dendríticas/metabolismo , Proteínas Fúngicas/metabolismo , Proteínas Fúngicas/imunologia , Lectinas Tipo C/metabolismo , Lectinas Tipo C/imunologia , Macrófagos/imunologia , Macrófagos/metabolismo , Transdução de Sinais
11.
Arch Microbiol ; 206(6): 253, 2024 May 10.
Artigo em Inglês | MEDLINE | ID: mdl-38727738

RESUMO

Candida auris is an invasive fungal pathogen of high concern due to acquired drug tolerance against antifungals used in clinics. The prolonged persistence on biotic and abiotic surfaces can result in onset of hospital outbreaks causing serious health threat. An in depth understanding of pathology of C. auris is highly desirable for development of efficient therapeutics. Non-coding RNAs play crucial role in fungal pathology. However, the information about ncRNAs is scanty to be utilized. Herein our aim is to identify long noncoding RNAs with potent role in pathobiology of C. auris. Thereby, we analyzed the transcriptomics data of C. auris infection in blood for identification of potential lncRNAs with regulatory role in determining invasion, survival or drug tolerance under infection conditions. Interestingly, we found 275 lncRNAs, out of which 253 matched with lncRNAs reported in Candidamine, corroborating for our accurate data analysis pipeline. Nevertheless, we obtained 23 novel lncRNAs not reported earlier. Three lncRNAs were found to be under expressed throughout the course of infection, in the transcriptomics data. 16 of potent lncRNAs were found to be coexpressed with coding genes, emphasizing for their functional role. Noteworthy, these ncRNAs are expressed from intergenic regions of the genes associated with transporters, metabolism, cell wall biogenesis. This study recommends for possible association between lncRNA expression and C. auris pathogenesis.


Assuntos
Candida auris , Candidíase , Interações entre Hospedeiro e Microrganismos , RNA Longo não Codificante , RNA Longo não Codificante/genética , RNA Longo não Codificante/isolamento & purificação , Perfilação da Expressão Gênica , Simulação por Computador , Estudo de Associação Genômica Ampla , Candida auris/genética , Candida auris/patogenicidade , Candidíase/sangue , Candidíase/microbiologia , Sepse/microbiologia , Interações entre Hospedeiro e Microrganismos/genética , Humanos
12.
J Proteome Res ; 23(5): 1634-1648, 2024 May 03.
Artigo em Inglês | MEDLINE | ID: mdl-38572994

RESUMO

The delay in making a correct diagnosis of Candida auris causes concern in the healthcare system setting, and immunoproteomics studies are important to identify immunoreactive proteins for new diagnostic strategies. In this study, immunocompetent murine systemic infections caused by non-aggregative and aggregative phenotypes of C. auris and by Candida albicans and Candida haemulonii were carried out, and the obtained sera were used to study their immunoreactivity against C. auris proteins. The results showed higher virulence, in terms of infection signs, weight loss, and histopathological damage, of the non-aggregative isolate. Moreover, C. auris was less virulent than C. albicans but more than C. haemulonii. Regarding the immunoproteomics study, 13 spots recognized by sera from mice infected with both C. auris phenotypes and analyzed by mass spectrometry corresponded to enolase, phosphoglycerate kinase, glyceraldehyde-3-phosphate dehydrogenase, and phosphoglycerate mutase. These four proteins were also recognized by sera obtained from human patients with disseminated C. auris infection but not by sera obtained from mice infected with C. albicans or Aspergillus fumigatus. Spot identification data are available via ProteomeXchange with the identifier PXD049077. In conclusion, this study showed that the identified proteins could be potential candidates to be studied as new diagnostic or even therapeutic targets for C. auris.


Assuntos
Candida , Candidíase , Imunoglobulina G , Animais , Camundongos , Candida/imunologia , Candida/patogenicidade , Humanos , Candidíase/imunologia , Candidíase/microbiologia , Candidíase/sangue , Imunoglobulina G/sangue , Antígenos de Fungos/imunologia , Antígenos de Fungos/sangue , Proteômica/métodos , Candida albicans/imunologia , Candida albicans/patogenicidade , Proteínas Fúngicas/imunologia , Fosfoglicerato Mutase/imunologia , Fosfoglicerato Quinase/imunologia , Gliceraldeído-3-Fosfato Desidrogenases/imunologia , Gliceraldeído-3-Fosfato Desidrogenases/metabolismo , Anticorpos Antifúngicos/sangue , Anticorpos Antifúngicos/imunologia , Feminino , Virulência
13.
mBio ; 15(5): e0057024, 2024 May 08.
Artigo em Inglês | MEDLINE | ID: mdl-38587425

RESUMO

Fungal resistance to commonly used medicines is a growing public health threat, and there is a dire need to develop new classes of antifungals. We previously described a peptide produced by Enterococcus faecalis, EntV, that restricts Candida albicans to a benign form rather than having direct fungicidal activity. Moreover, we showed that one 12-amino acid (aa) alpha helix of this peptide retained full activity, with partial activity down to the 10aa alpha helix. Using these peptides as a starting point, the current investigation sought to identify the critical features necessary for antifungal activity and to screen for new variants with enhanced activity using both biofilm and C. elegans infection assays. First, the short peptides were screened for residues with critical activity by generating alanine substitutions. Based on this information, we used synthetic molecular evolution (SME) to rationally vary the specific residues of the 10aa variant in combination to generate a library that was screened to identify variants with more potent antifungal activity than the parent template. Five gain-of-function peptides were identified. Additionally, chemical modifications to the peptides to increase stability, including substitutions of D-amino acids and hydrocarbon stapling, were investigated. The most promising peptides were additionally tested in mouse models of oropharyngeal and systemic candidiasis where their efficacy in preventing infection was demonstrated. The expectation is that these discoveries will contribute to the development of new therapeutics in the fight against antimicrobial resistant fungi. IMPORTANCE: Since the early 1980s, the incidence of disseminated life-threatening fungal infections has been on the rise. Worldwide, Candida and Cryptococcus species are among the most common agents causing these infections. Simultaneously, with this rise of clinical incidence, there has also been an increased prevalence of antifungal resistance, making treatment of these infections very difficult. For example, there are now strains of Candida auris that are resistant to all three classes of currently used antifungal drugs. In this study, we report on a strategy that allows for the development of novel antifungal agents by using synthetic molecular evolution. These discoveries demonstrate that the enhancement of antifungal activity from naturally occurring peptides is possible and can result in clinically relevant agents that have efficacy in multiple in vivo models as well as the potential for broad-spectrum activity.


Assuntos
Antifúngicos , Biofilmes , Caenorhabditis elegans , Candida albicans , Candidíase , Enterococcus faecalis , Testes de Sensibilidade Microbiana , Antifúngicos/farmacologia , Antifúngicos/química , Animais , Camundongos , Candida albicans/efeitos dos fármacos , Candida albicans/genética , Biofilmes/efeitos dos fármacos , Candidíase/tratamento farmacológico , Candidíase/microbiologia , Enterococcus faecalis/efeitos dos fármacos , Enterococcus faecalis/genética , Caenorhabditis elegans/efeitos dos fármacos , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Proteínas de Bactérias/química , Proteínas de Bactérias/farmacologia , Modelos Animais de Doenças , Peptídeos/farmacologia , Peptídeos/genética , Peptídeos/química
14.
mBio ; 15(5): e0064924, 2024 May 08.
Artigo em Inglês | MEDLINE | ID: mdl-38619236

RESUMO

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


Assuntos
Antifúngicos , Candida albicans , Candidíase , Criptococose , Cryptococcus neoformans , Dieta Cetogênica , Modelos Animais de Doenças , Fluconazol , Animais , Fluconazol/farmacologia , Fluconazol/administração & dosagem , Camundongos , Antifúngicos/administração & dosagem , Antifúngicos/farmacologia , Candidíase/tratamento farmacológico , Candidíase/dietoterapia , Candidíase/microbiologia , Candida albicans/efeitos dos fármacos , Cryptococcus neoformans/efeitos dos fármacos , Criptococose/tratamento farmacológico , Criptococose/microbiologia , Criptococose/dietoterapia , Criptococose/prevenção & controle , Feminino , Encéfalo/metabolismo , Encéfalo/efeitos dos fármacos , Pulmão/microbiologia , Pulmão/efeitos dos fármacos
15.
Microb Genom ; 10(4)2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38630608

RESUMO

Fungal pathogens commonly originate from benign or non-pathogenic strains living in the natural environment. The recently emerged human pathogen, Candida auris, is one example of a fungus believed to have originated in the environment and recently transitioned into a clinical setting. To date, however, there is limited evidence about the origins of this species in the natural environment and when it began associating with humans. One approach to overcome this gap is to reconstruct phylogenetic relationships between (1) strains isolated from clinical and non-clinical environments and (2) between species known to cause disease in humans and benign environmental saprobes. C. auris belongs to the Candida/Clavispora clade, a diverse group of 45 yeast species including human pathogens and environmental saprobes. We present a phylogenomic analysis of the Candida/Clavispora clade aimed at understanding the ecological breadth and evolutionary relationships between an expanded sample of environmentally and clinically isolated yeasts. To build a robust framework for investigating these relationships, we developed a whole-genome sequence dataset of 108 isolates representing 18 species, including four newly sequenced species and 18 environmentally isolated strains. Our phylogeny, based on 619 orthologous genes, shows environmentally isolated species and strains interspersed with clinically isolated counterparts, suggesting that there have been many transitions between humans and the natural environment in this clade. Our findings highlight the breadth of environments these yeasts inhabit and imply that many clinically isolated yeasts in this clade could just as easily live outside the human body in diverse natural environments and vice versa.


Assuntos
Candida auris , Candidíase , Humanos , Filogenia , Candidíase/microbiologia , Candida/genética , Evolução Biológica
16.
PLoS Pathog ; 20(4): e1012154, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38603707

RESUMO

Candida albicans chronically colonizes the respiratory tract of patients with Cystic Fibrosis (CF). It competes with CF-associated pathogens (e.g. Pseudomonas aeruginosa) and contributes to disease severity. We hypothesize that C. albicans undergoes specific adaptation mechanisms that explain its persistence in the CF lung environment. To identify the underlying genetic and phenotypic determinants, we serially recovered 146 C. albicans clinical isolates over a period of 30 months from the sputum of 25 antifungal-naive CF patients. Multilocus sequence typing analyses revealed that most patients were individually colonized with genetically close strains, facilitating comparative analyses between serial isolates. We strikingly observed differential ability to filament and form monospecies and dual-species biofilms with P. aeruginosa among 18 serial isolates sharing the same diploid sequence type, recovered within one year from a pediatric patient. Whole genome sequencing revealed that their genomes were highly heterozygous and similar to each other, displaying a highly clonal subpopulation structure. Data mining identified 34 non-synonymous heterozygous SNPs in 19 open reading frames differentiating the hyperfilamentous and strong biofilm-former strains from the remaining isolates. Among these, we detected a glycine-to-glutamate substitution at position 299 (G299E) in the deduced amino acid sequence of the zinc cluster transcription factor ROB1 (ROB1G299E), encoding a major regulator of filamentous growth and biofilm formation. Introduction of the G299E heterozygous mutation in a co-isolated weak biofilm-former CF strain was sufficient to confer hyperfilamentous growth, increased expression of hyphal-specific genes, increased monospecies biofilm formation and increased survival in dual-species biofilms formed with P. aeruginosa, indicating that ROB1G299E is a gain-of-function mutation. Disruption of ROB1 in a hyperfilamentous isolate carrying the ROB1G299E allele abolished hyperfilamentation and biofilm formation. Our study links a single heterozygous mutation to the ability of C. albicans to better survive during the interaction with other CF-associated microbes and illuminates how adaptive traits emerge in microbial pathogens to persistently colonize and/or infect the CF-patient airways.


Assuntos
Biofilmes , Candida albicans , Fibrose Cística , Proteínas Fúngicas , Fatores de Transcrição , Fibrose Cística/microbiologia , Candida albicans/genética , Candida albicans/metabolismo , Humanos , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Biofilmes/crescimento & desenvolvimento , Proteínas Fúngicas/genética , Proteínas Fúngicas/metabolismo , Mutação com Ganho de Função , Pseudomonas aeruginosa/genética , Pseudomonas aeruginosa/metabolismo , Pulmão/microbiologia , Candidíase/microbiologia , Adaptação Fisiológica
17.
Mycopathologia ; 189(3): 35, 2024 Apr 18.
Artigo em Inglês | MEDLINE | ID: mdl-38637433

RESUMO

Candida auris, an emerging and multidrug-resistant fungal pathogen, has led to numerous outbreaks in China. While the resistance mechanisms against azole and amphotericin B have been studied, the development of drug resistance in this pathogen remains poorly understood, particularly in in vivo-generated drug-resistant strains. This study employed pathogen whole-genome sequencing to investigate the epidemiology and drug-resistance mutations of C. auris using 16 strains isolated from two patients. Identification was conducted through Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry, and antimicrobial susceptibilities were assessed using broth microdilution and Sensititre YeastOne YO10. Whole-genome sequencing revealed that all isolates belonged to the South Asian lineage, displaying genetic heterogeneity. Despite low genetic variability among patient isolates, notable mutations were identified, including Y132F in ERG11 and A585S in TAC1b, likely linked to increased fluconazole resistance. Strains from patient B also carried F214L in TAC1b, resulting in a consistent voriconazole minimum inhibitory concentration of 4 µg/mL across all isolates. Furthermore, a novel frameshift mutation in the SNG1 gene was observed in amphotericin B-resistant isolates compared to susceptible ones. Our findings suggest the potential transmission of C. auris and emphasize the need to explore variations related to antifungal resistance. This involves analyzing genomic mutations and karyotypes, especially in vivo, to compare sensitive and resistant strains. Further monitoring and validation efforts are crucial for a comprehensive understanding of the mechanisms of drug resistance in C. auris.


Assuntos
Antifúngicos , Candidíase , Humanos , Antifúngicos/farmacologia , Candidíase/microbiologia , Candida auris , Candida , Anfotericina B/farmacologia , Farmacorresistência Fúngica/genética , Testes de Sensibilidade Microbiana
18.
Clin Lab ; 70(4)2024 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-38623664

RESUMO

BACKGROUND: Despite the advanced laboratory technologies available today, blood culture is the gold standard method in the diagnosis of bloodstream infections. Automated blood culture devices give blood culture results for laboratories approximately in 2 - 3 days up to 7 days. Moreover, some microorganisms like nonreproducible bacteria, fungi or viruses cannot be produced in culture. Among all samples taken for blood culture on suspicion of infection approximately 10% are determined as positive whereas the false positive rate due to contamination is 5%. Especially in life-threatening severe conditions such as sepsis early diagnosis and prompt treatment are crucial. Based on this the aim of this study is to investigate complete blood count parameters as potential early markers in Escherichia coli, Staphylococcus aureus and Candida albicans bloodstream infections using an ex vivo whole blood model. METHODS: Blood samples collected from healthy donors (n = 10) were treated with suspensions containing a certain concentration of microorganisms (107 CFU/mL for both E. coli ATCC 25922 and S. aureus ATCC 29213, 106 CFU/mL for C. albicans ATCC 14053). After bacteremia and candidemia were induced, complete blood count parameters were analyzed hourly in the samples until the end of the 4th hour with a Mindray BC-6800 hematology analyzer. Statistical analysis was performed by Tukey-Kramer post-hoc multiple comparison test and statistical significance was accepted as p < 0.05. RESULTS: When platelet derived parameter baseline values were compared to hourly values in E. coli and S. aureus induced whole blood samples, it was found that the decrease in PLT, P-LCC and the increase in IPF% was significant from the first hour whereas the increase in IMG% was found to be significant only from the 3rd hour onward. In the experiments with C. albicans, it was observed that the increase in IPF% and IMG% was significant from the 2nd and 3rd hour onward, respectively. There was no relationship between MPV, P-LCR, and NLR baseline and hourly results in any microorganism induced model. CONCLUSIONS: IPF% can guide clinicians in the early diagnosis and management of treatment of infections caused by S. aureus, E. coli, and C. albicans.


Assuntos
Candidemia , Candidíase , Humanos , Escherichia coli , Staphylococcus aureus , Candida albicans , Candidíase/diagnóstico , Candidíase/microbiologia , Candidemia/microbiologia , Contagem de Células Sanguíneas
19.
Emerg Infect Dis ; 30(13): S36-S40, 2024 04.
Artigo em Inglês | MEDLINE | ID: mdl-38561642

RESUMO

Candida auris is an emerging fungal pathogen that typically affects patients in healthcare settings. Data on C. auris cases in correctional facilities are limited but are needed to guide public health recommendations. We describe cases and challenges of providing care for 13 patients who were transferred to correctional facilities during January 2020-December 2022 after having a positive C. auris specimen. All patients had positive specimens identified while receiving inpatient care at healthcare facilities in geographic areas with high C. auris prevalence. Correctional facilities reported challenges managing patients and implementing prevention measures; those challenges varied by whether patients were housed in prison medical units or general population units. Although rarely reported, C. auris cases in persons who are incarcerated may occur, particularly in persons with known risk factors. Measures to manage cases and prevent C. auris spread in correctional facilities should address setting-specific challenges in healthcare and nonhealthcare correctional environments.


Assuntos
Candida , Candidíase , Humanos , Candidíase/microbiologia , Candida auris , Antifúngicos/uso terapêutico , Estabelecimentos Correcionais
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