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1.
Rev Soc Bras Med Trop ; 53: e20190214, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32049200

RESUMO

INTRODUCTION: The aim of this study was to evaluate some virulence factors in Candida albicans isolates from patients with onychomycosis and determine the correlation between these factors and the antifungal resistance profile. METHODS: Seventy species of C. albicans were confirmed using polymerase chain reaction amplification of the HWP1 gene. According to the Clinical & Laboratory Standards Institute guidelines, the susceptibility profile of four antifungal agents was investigated, and the production of aspartyl protease, phospholipase, haemolysin, and biofilm was determined. The correlation between these profiles was also investigated. RESULTS: The isolates indicated different levels of resistance and production of virulence factors. Significant correlations were observed between the minimum inhibitory concentration (MIC) of fluconazole/itraconazole and biofilm production, between phospholipase production and fluconazole/itraconazole MIC, and between fluconazole MIC and hemolytic activity in C. albicans isolates. The results also showed significant correlations between phospholipase activity and biofilm production. CONCLUSIONS: Our findings will contribute to a better understanding of the pathogenesis of C. albicans and characterize the relationship between virulence factors and antifungal resistance, which may suggest new therapeutic strategies considering the possible involvement of the virulence mechanism in the effectiveness of treatment.


Assuntos
Antifúngicos/farmacologia , Candida albicans/patogenicidade , Unhas/microbiologia , Onicomicose/microbiologia , Fatores de Virulência , Ácido Aspártico Proteases/biossíntese , Biofilmes/crescimento & desenvolvimento , Candida albicans/efeitos dos fármacos , Candida albicans/ultraestrutura , Farmacorresistência Fúngica , Hemólise , Humanos , Testes de Sensibilidade Microbiana , Microscopia Eletrônica de Varredura , Fosfolipases/biossíntese , Reação em Cadeia da Polimerase
2.
PLoS Genet ; 16(1): e1008582, 2020 01.
Artigo em Inglês | MEDLINE | ID: mdl-31961865

RESUMO

Metabolic adaptation is linked to the ability of the opportunistic pathogen Candida albicans to colonize and cause infection in diverse host tissues. One way that C. albicans controls its metabolism is through the glucose repression pathway, where expression of alternative carbon source utilization genes is repressed in the presence of its preferred carbon source, glucose. Here we carry out genetic and gene expression studies that identify transcription factors Mig1 and Mig2 as mediators of glucose repression in C. albicans. The well-studied Mig1/2 orthologs ScMig1/2 mediate glucose repression in the yeast Saccharomyces cerevisiae; our data argue that C. albicans Mig1/2 function similarly as repressors of alternative carbon source utilization genes. However, Mig1/2 functions have several distinctive features in C. albicans. First, Mig1 and Mig2 have more co-equal roles in gene regulation than their S. cerevisiae orthologs. Second, Mig1 is regulated at the level of protein accumulation, more akin to ScMig2 than ScMig1. Third, Mig1 and Mig2 are together required for a unique aspect of C. albicans biology, the expression of several pathogenicity traits. Such Mig1/2-dependent traits include the abilities to form hyphae and biofilm, tolerance of cell wall inhibitors, and ability to damage macrophage-like cells and human endothelial cells. Finally, Mig1 is required for a puzzling feature of C. albicans biology that is not shared with S. cerevisiae: the essentiality of the Snf1 protein kinase, a central eukaryotic carbon metabolism regulator. Our results integrate Mig1 and Mig2 into the C. albicans glucose repression pathway and illuminate connections among carbon control, pathogenicity, and Snf1 essentiality.


Assuntos
Candida albicans/genética , Proteínas Fúngicas/metabolismo , Regulação Fúngica da Expressão Gênica , Glucose/metabolismo , Fatores de Transcrição/metabolismo , Animais , Biofilmes , Candida albicans/efeitos dos fármacos , Candida albicans/patogenicidade , Linhagem Celular , Farmacorresistência Fúngica , Células Endoteliais/microbiologia , Proteínas Fúngicas/genética , Humanos , Macrófagos/microbiologia , Camundongos , Proteínas Serina-Treonina Quinases/metabolismo , Fatores de Transcrição/genética
3.
PLoS Pathog ; 15(12): e1007823, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-31809527

RESUMO

Inside the human host, the pathogenic yeast Candida albicans colonizes predominantly oxygen-poor niches such as the gastrointestinal and vaginal tracts, but also oxygen-rich environments such as cutaneous epithelial cells and oral mucosa. This suppleness requires an effective mechanism to reversibly reprogram the primary metabolism in response to oxygen variation. Here, we have uncovered that Snf5, a subunit of SWI/SNF chromatin remodeling complex, is a major transcriptional regulator that links oxygen status to the metabolic capacity of C. albicans. Snf5 and other subunits of SWI/SNF complex were required to activate genes of carbon utilization and other carbohydrates related process specifically under hypoxia. snf5 mutant exhibited an altered metabolome reflecting that SWI/SNF plays an essential role in maintaining metabolic homeostasis and carbon flux in C. albicans under hypoxia. Snf5 was necessary to activate the transcriptional program linked to both commensal and invasive growth. Accordingly, snf5 was unable to maintain its growth in the stomach, the cecum and the colon of mice. snf5 was also avirulent as it was unable to invade Galleria larvae or to cause damage to human enterocytes and murine macrophages. Among candidates of signaling pathways in which Snf5 might operate, phenotypic analysis revealed that mutants of Ras1-cAMP-PKA pathway, as well as mutants of Yak1 and Yck2 kinases exhibited a similar carbon flexibility phenotype as did snf5 under hypoxia. Genetic interaction analysis indicated that the adenylate cyclase Cyr1, a key component of the Ras1-cAMP pathway interacted genetically with Snf5. Our study yielded new insight into the oxygen-sensitive regulatory circuit that control metabolic flexibility, stress, commensalism and virulence in C. albicans.


Assuntos
Candida albicans/metabolismo , Candida albicans/patogenicidade , Regulação Fúngica da Expressão Gênica/fisiologia , Virulência/fisiologia , Animais , Candida albicans/genética , Proteínas Fúngicas/metabolismo , Interações entre Hospedeiro e Microrganismos/fisiologia , Humanos , Fatores de Transcrição/metabolismo
4.
Nat Commun ; 10(1): 4566, 2019 10 08.
Artigo em Inglês | MEDLINE | ID: mdl-31594939

RESUMO

Fungal dissemination into the bloodstream is a critical step leading to invasive fungal infections. Here, using intravital imaging, we show that Kupffer cells (KCs) in the liver have a prominent function in the capture of circulating Cryptococcus neoformans and Candida albicans, thereby reducing fungal dissemination to target organs. Complement C3 but not C5, and complement receptor CRIg but not CR3, are involved in capture of C. neoformans. Internalization of C. neoformans by KCs is subsequently mediated by multiple receptors, including CR3, CRIg, and scavenger receptors, which work synergistically along with C5aR signaling. Following phagocytosis, the growth of C. neoformans is inhibited by KCs in an IFN-γ independent manner. Thus, the liver filters disseminating fungi from circulation via KCs, providing a mechanistic explanation for the enhanced risk of cryptococcosis among individuals with liver diseases, and suggesting a therapeutic strategy to prevent fungal dissemination through enhancing KC functions.


Assuntos
Infecções Fúngicas Invasivas/imunologia , Macrófagos do Fígado/imunologia , Fígado/imunologia , Fagocitose , Animais , Candida albicans/imunologia , Candida albicans/isolamento & purificação , Candida albicans/patogenicidade , Complemento C3/genética , Complemento C3/imunologia , Complemento C3/metabolismo , Cryptococcus neoformans/imunologia , Cryptococcus neoformans/isolamento & purificação , Cryptococcus neoformans/patogenicidade , Modelos Animais de Doenças , Feminino , Humanos , Microscopia Intravital , Infecções Fúngicas Invasivas/sangue , Infecções Fúngicas Invasivas/microbiologia , Macrófagos do Fígado/metabolismo , Macrófagos do Fígado/microbiologia , Fígado/citologia , Fígado/diagnóstico por imagem , Masculino , Camundongos , Camundongos Knockout , Microscopia Confocal , Receptores de Complemento/genética , Receptores de Complemento/imunologia , Receptores de Complemento/metabolismo
5.
Int J Med Microbiol ; 309(6): 151330, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31471070

RESUMO

OBJECTIVE: Alcohol dehydrogenase I is encoded by ADH1 in Candida albicans, and is one of the key enzymes in fungal metabolism by which it catalyzes the conversion from acetaldehyde to ethanol. The role of the associated protein Adh1p, encoded by ADH1 in fungal pathogenicity has not been thoroughly studied despite its near ubiquity in the fungal kingdom. Using C. albicans as a model, this study proposes to determine the possible pathogenic roles for ADH1 and its possible underlying mechanisms. METHODS: The SAT1 flipper strategy was used to construct the ADH1 deletion mutant. Growth curves and spot assay were used to compare growth and cell viability of the mutant to wild type C. albicans. Three host model systems (infected mice, C. elegans, and G. mellonella) were used to investigate the effects of ADH1 deletion in vivo on C. albicans pathogenicity. Then, adhesion, hyphal formation, biofilm formation, cell surface hydrophobicity (CSH) and RT-qPCR were performed to investigate the effects of ADH1 deletion in vitro on C. albicans virulence. Finally, Xfe 96 seahorse assay, ROS level, mitochondrial membrane potential, and intracellular ATP content were used to determine the effects of ADH1 deletion on bioenergetics. RESULTS: ADH1 deletion has no effects on the growth and cell viability of C. albicans, but significantly prolongs survival time in each of the three host models, decreases fungal burden in kidney and liver, and lessens pathological tissue damage (P <  0.05). In addition, ADH1 deletion significantly increases CSH and reduces C. albicans virulence in terms of adhesion, hyphal formation and biofilm formation in accord with the downregulation of virulence-related genes such as ALS1, ALS3, HWP1, and CSH1 (P <  0.05). For bioenergetics, ADH1 deletion has no obvious effect on glycolysis, but a lack of ADH1 significantly increases ROS levels and decreases mitochondrial membrane potential and intracellular ATP content even through the mitochondrial oxygen consumption rate and NADH/NAD+ ratio are elevated (P <  0.05). CONCLUSION: Our results suggest that the fermentative enzyme ADH1 is required for the pathogenicity of C. albicans under one of the presumed mechanisms viaits effects on oxidative phosphorylation activities in mitochondria.


Assuntos
Álcool Desidrogenase/metabolismo , Candida albicans/patogenicidade , Candidíase/metabolismo , Proteínas Fúngicas/metabolismo , Fosforilação Oxidativa , Virulência/genética , Álcool Desidrogenase/genética , Animais , Biofilmes/crescimento & desenvolvimento , Caenorhabditis elegans , Candida albicans/genética , Candidíase/microbiologia , Adesão Celular , Modelos Animais de Doenças , Proteínas Fúngicas/genética , Regulação Fúngica da Expressão Gênica , Hifas/crescimento & desenvolvimento , Camundongos Endogâmicos ICR , Mitocôndrias/metabolismo , Mariposas , Espécies Reativas de Oxigênio/metabolismo , Deleção de Sequência
6.
BMC Infect Dis ; 19(1): 716, 2019 Aug 14.
Artigo em Inglês | MEDLINE | ID: mdl-31412796

RESUMO

BACKGROUND: Asymptom of invasive candidiasis (IC) and low positive rate of blood culture lead to delay diagnose of neonatal infection. Serum (1,3)-ß-D-glucan (BDG) performs well in adult IC, but its use in neonatal IC is unclear. We evaluated the use of BDG, procalcitonin (PCT), high-sensitive C-reactive protein (hsCRP) or platelet count (PC) in neonatal IC. METHODS: We collected the data of neonates admitted to our institute. Eighty neonates were enrolled, and divided into IC group, bacterial infection (BI) group and control (CTRL) group. We analyzed the difference of these indicators between groups, and generated Receiver operator characteristic (ROC) curve. The value of BDG in antifungal therapy efficacy assessment was also investigated. RESULTS: The BDG level was higher in IC group compared with BI and CTRL group. C. albicans lead to significant increase of BDG compared with C. parapsilosis. IC group had highest hsCRP level and lowest PC. PCT level was similar between groups. ROC showed that BDG or hsCRP performs well in neonatal IC, the optimal cut-off for BDG was 13.69 mg/ml. Combined BDG with hsCRP, PCT and PC increased diagnostic value. Serum BDG level was decreased during antifungal treatment. CONCLUSION: Serum BDG performs well in identification of neonatal IC and in monitoring the antifungal therapy efficacy.


Assuntos
Biomarcadores/sangue , Candidíase Invasiva/sangue , beta-Glucanas/sangue , Adulto , Antifúngicos/uso terapêutico , Proteína C-Reativa/análise , Candida albicans/patogenicidade , Candida parapsilosis/patogenicidade , Candidemia/sangue , Candidemia/tratamento farmacológico , Candidemia/microbiologia , Candidíase Invasiva/tratamento farmacológico , Candidíase Invasiva/microbiologia , Feminino , Ruptura Prematura de Membranas Fetais , Humanos , Recém-Nascido , Doenças do Recém-Nascido/tratamento farmacológico , Doenças do Recém-Nascido/microbiologia , Masculino , Gravidez , Curva ROC , Estudos Retrospectivos , Especificidade da Espécie , Resultado do Tratamento
7.
J Mycol Med ; 29(3): 210-218, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31400863

RESUMO

OBJECTIVE: The rise in fungal infections is alarming due to emergence of multidrug drug resistance (MDR). Hence elucidating novel drug targets to circumvent the problem of MDR warrants immediate attention. This study analyzes the effect of retrograde (RTG) signaling disruption on major MDR mechanisms and virulence of the human pathogenic fungal species Candida albicans. MATERIAL AND METHODS: Drug transporter activity was measured by rhodamine 6G (R6G) efflux. Membrane damage was studied by propidium iodide intake and ergosterol level determination. Cell wall effect was estimated by quantifying chitin levels and cell sedimentation rate. Biofilm formation was visualized by calcoflour white and crystal violet staining and measured by dry mass and MTT assay. Cell adherence to buccal epithelial cell was determined by trypan blue staining and MTT assay. Virulence was studied using nematode model Caenorhabditis elegans. RESULT: We demonstrated that mutant of transcription factor CaRTG3 leads to impaired efflux activity of ATP Binding Cassette (ABC) superfamily multidrug transporters. We further uncover that rtg3 mutant exhibited a disrupted membrane, decreased ergosterol levels and increased chitin content. Furthermore, RTG signaling disruption leads to inhibited biofilm formation and cell adherence to buccal epithelial cells. Lastly, rtg3 mutant displayed a reduced infectivity in C. elegans illustrating its vulnerability as antifungal target. Interestingly, all the abrogated phenotypes could be rescued in the revertant strain of rtg3 mutant. CONCLUSION: Present study establishes a link between RTG signaling, drug efflux and biofilm formation and validates CaRTG3 as antifungal target. Intricate studies are needed to further understand and exploit this therapeutic opportunity.


Assuntos
Biofilmes/crescimento & desenvolvimento , Candida albicans/metabolismo , Quitina/análise , Ergosterol/análise , Proteínas de Membrana Transportadoras/genética , Transdução de Sinais , Animais , Transporte Biológico , Caenorhabditis elegans/microbiologia , Candida albicans/genética , Candida albicans/patogenicidade , Candidíase/microbiologia , Modelos Animais de Doenças , Proteínas de Membrana Transportadoras/metabolismo , Virulência
8.
Infect Immun ; 87(10)2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31383746

RESUMO

Candida albicans, a major opportunistic fungal pathogen, is frequently found together with Streptococcus mutans in dental biofilms associated with severe childhood caries (tooth decay), a prevalent pediatric oral disease. However, the impact of this cross-kingdom relationship on C. albicans remains largely uncharacterized. Here, we employed a novel quantitative proteomics approach in conjunction with transcriptomic profiling to unravel molecular pathways of C. albicans when cocultured with S. mutans in mixed biofilms. RNA sequencing and iTRAQ (isobaric tags for relative and absolute quantitation)-based quantitative proteomics revealed that C. albicans genes and proteins associated with carbohydrate metabolism were significantly enhanced, including sugar transport, aerobic respiration, pyruvate breakdown, and the glyoxylate cycle. Other C. albicans genes and proteins directly and indirectly related to cell morphogenesis and cell wall components such as mannan and glucan were also upregulated, indicating enhanced fungal activity in mixed-species biofilm. Further analyses revealed that S. mutans-derived exoenzyme glucosyltransferase B (GtfB), which binds to the fungal cell surface to promote coadhesion, can break down sucrose into glucose and fructose that can be readily metabolized by C. albicans, enhancing growth and acid production. Altogether, we identified key pathways used by C. albicans in the mixed biofilm, indicating an active fungal role in the sugar metabolism and environmental acidification (key virulence traits associated with caries onset) when interacting with S. mutans, and a new cross-feeding mechanism mediated by GtfB that enhances C. albicans carbohydrate utilization. In addition, we demonstrate that comprehensive transcriptomics and quantitative proteomics can be powerful tools to study microbial contributions which remain underexplored in cross-kingdom biofilms.


Assuntos
Biofilmes/crescimento & desenvolvimento , Candida albicans/genética , Regulação Bacteriana da Expressão Gênica , Regulação Fúngica da Expressão Gênica , Streptococcus mutans/genética , Transcriptoma , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Candida albicans/metabolismo , Candida albicans/patogenicidade , Metabolismo dos Carboidratos , Parede Celular/metabolismo , Criança , Técnicas de Cocultura , Cárie Dentária/microbiologia , Cárie Dentária/patologia , Glucanos/metabolismo , Glucosiltransferases/genética , Glucosiltransferases/metabolismo , Humanos , Proteômica , Streptococcus mutans/metabolismo , Streptococcus mutans/patogenicidade , Simbiose/genética
9.
BMC Infect Dis ; 19(1): 698, 2019 Aug 06.
Artigo em Inglês | MEDLINE | ID: mdl-31387541

RESUMO

BACKGROUND: Candida albicans is an opportunistic pathogen, but since it also belongs to the normal fungal flora, positive sputum culture as the solely basis for the diagnosis of invasive Candida albicans pneumonia can easily lead to excessive antifungal therapy. Therefore, identification of a pneumonia biomarker might improve diagnostic accuracy. METHODS: A rabbit model was established by inoculating 5 × 107 cfu/mL C. albicans into the trachea of 20 rabbits with 20 rabbits as control group. Infection was monitored by chest thin-layer computed tomography (CT). 2 mL blood samples were collected daily during each infection and serum levels of potential biomarkers were measured by enzyme-linked immunosorbent assay (ELISA). Seven-day post-inoculation the rabbits were sacrificed by CO2 asphyxiation and lung tissue was histopathologically examined and blood was brought to culture. Data were statistically analyzed. RESULTS: Infection became evident as early as day 3 post-inoculation. The levels of soluble triggering receptor expressed on myeloid cells-1 (sTREM-1), soluble hemoglobin-haptoglobin scavenger receptor (sCD163), procalcitonin (PCT) and tumor necrosis factor-α (TNF-α) were elevated in the experimental group compared to the control (P < 0.01), whereas the levels of C-reactive protein (CRP), interleukin-6 (IL-6), IL-8 and IL-10 showed no significant differences (P > 0.05). The dynamic curves of the levels of CRP, IL-6, IL-8, IL-10, SCD163 and TNF-α in both groups demonstrated a similar trend during infection but differences between the groups was observed only in the sTREM-1 levels. Receiver-operating characteristics (ROC) curve analysis showed that the sensitivity and specificity were 85 and 80% for sTREM-1 (cut-off value: 45.88 pg/mL) and 80 and 75% for SCD163 (cut-off value: 16.44 U/mL), respectively. The values of the area under the ROC curve (AUCROC) of sTREM-1 and SCD163 were 0.882 (95% CI: 0.922-0.976) and 0.814 (95% CI: 0.678-0.950), respectively. Other markers did not exhibit significant differences. CONCLUSION: sTREM-1 and SCD163 might be suitable biomarkers for pneumonia.


Assuntos
Antígenos CD/sangue , Antígenos de Diferenciação Mielomonocítica/sangue , Biomarcadores/sangue , Pneumonia/sangue , Receptores de Superfície Celular/sangue , Receptor Gatilho 1 Expresso em Células Mieloides/sangue , Animais , Proteína C-Reativa/análise , Candida albicans/patogenicidade , Candidíase/sangue , Candidíase/microbiologia , Modelos Animais de Doenças , Masculino , Pneumonia/diagnóstico , Pneumonia/microbiologia , Curva ROC , Coelhos , Sensibilidade e Especificidade , Fator de Necrose Tumoral alfa/sangue
10.
mSphere ; 4(4)2019 08 21.
Artigo em Inglês | MEDLINE | ID: mdl-31434751

RESUMO

Matt Anderson works in the field of genetics and infectious disease, with a focus on the human fungal pathogen Candida albicans In this mSphere of Influence article, he reflects on how two papers, "Gene Flow Contributes to Diversification of the Major Fungal Pathogen Candida albicans" (J. Ropars, C. Maufrais, D. Diogo, M. Marcet-Houben, A. Perin, et al., Nat Commun 9:2253, 2018, https://doi.org/10.1038/s41467-018-04787-4) and "Selection of Candida albicans Trisomy during Oropharyngeal Infection Results in a Commensal-Like Phenotype" (A. Forche, N. V. Solis, M. Swidergall, R. Thomas, A. Guyer, et al., PLoS Genet 15:e1008137, 2019, https://doi.org/10.1371/journal.pgen.1008137), made an impact on him by incorporating less commonly investigated mechanisms of genome evolution into the context of microbial adaptation.


Assuntos
Candida albicans/genética , Candida albicans/patogenicidade , Virulência
11.
PLoS Biol ; 17(7): e3000358, 2019 07.
Artigo em Inglês | MEDLINE | ID: mdl-31283755

RESUMO

Hsp90 is a conserved molecular chaperone that assists in the folding and function of diverse cellular regulators, with a profound impact on biology, disease, and evolution. As a central hub of protein interaction networks, Hsp90 engages with hundreds of protein-protein interactions within eukaryotic cells. These interactions include client proteins, which physically interact with Hsp90 and depend on the chaperone for stability or function, as well as co-chaperones and partner proteins that modulate chaperone function. Currently, there are no methods to accurately predict Hsp90 interactors and there has been considerable network rewiring over evolutionary time, necessitating experimental approaches to define the Hsp90 network in the species of interest. This is a pressing challenge for fungal pathogens, for which Hsp90 is a key regulator of stress tolerance, drug resistance, and virulence traits. To address this challenge, we applied a novel biochemical fractionation and quantitative proteomic approach to examine alterations to the proteome upon perturbation of Hsp90 in a leading human fungal pathogen, Candida albicans. In parallel, we performed affinity purification coupled to mass spectrometry to define physical interacting partners for Hsp90 and the Hsp90 co-chaperones and identified 164 Hsp90-interacting proteins, including 111 that are specific to the pathogen. We performed the first analysis of the Hsp90 interactome upon antifungal drug stress and demonstrated that Hsp90 stabilizes processing body (P-body) and stress granule proteins that contribute to drug tolerance. We also describe novel roles for Hsp90 in regulating posttranslational modification of the Rvb1-Rvb2-Tah1-Pih1 (R2TP) complex and the formation of protein aggregates in response to thermal stress. This study provides a global view of the Hsp90 interactome in a fungal pathogen, demonstrates the dynamic role of Hsp90 in response to environmental perturbations, and highlights a novel connection between Hsp90 and the regulation of mRNA-associated protein granules.


Assuntos
Candida albicans/metabolismo , Proteínas Fúngicas/metabolismo , Proteínas de Choque Térmico HSP90/metabolismo , Chaperonas Moleculares/metabolismo , Proteômica/métodos , Candida albicans/genética , Candida albicans/patogenicidade , Candidíase/microbiologia , Proteínas Fúngicas/genética , Redes Reguladoras de Genes , Proteínas de Fluorescência Verde/genética , Proteínas de Fluorescência Verde/metabolismo , Proteínas de Choque Térmico HSP90/genética , Humanos , Microscopia Confocal , Chaperonas Moleculares/genética , Complexos Multiproteicos/genética , Complexos Multiproteicos/metabolismo , Ligação Proteica , Proteoma/genética , Proteoma/metabolismo , Virulência/genética
12.
Biomed Res Int ; 2019: 1851740, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31275963

RESUMO

The human opportunistic fungal pathogen Candida albicans causes a severe health burden while the biofilms formed by C. albicans present a kind of infections that are hard to cure, highlighting the pressing need for new antifungal drugs against C. albicans. This study was to explore the antifungal activities of lycorine hydrochloride (LH) against C. albicans. The minimal inhibitory concentration (MIC) of LH against C. albicans SC5314 was 64 µM. Below its MIC, LH demonstrated antivirulence property by suppressing adhesion, filamentation, biofilm formation, and development, as well as the production of extracellular phospholipase and exopolymeric substances (EPS). The cytotoxicity of LH against mammalian cells was low, with half maximal inhibitory concentrations (IC50) above 256 µM. Moreover, LH showed a synergistic effect with AmB, although its interaction with fluconazole, as well as caspofungin, was indifferent. Thus, our study reports the potential use of LH, alone or in combination with current antifungal drugs, to fight C. albicans infections.


Assuntos
Alcaloides de Amaryllidaceae/farmacologia , Candida albicans/patogenicidade , Fenantridinas/farmacologia , Adesividade/efeitos dos fármacos , Alcaloides de Amaryllidaceae/química , Alcaloides de Amaryllidaceae/toxicidade , Antifúngicos/química , Antifúngicos/farmacologia , Antifúngicos/toxicidade , Biofilmes/efeitos dos fármacos , Candida albicans/efeitos dos fármacos , Candida albicans/fisiologia , Morte Celular/efeitos dos fármacos , AMP Cíclico/metabolismo , Matriz Extracelular de Substâncias Poliméricas/metabolismo , Células Endoteliais da Veia Umbilical Humana/efeitos dos fármacos , Humanos , Hifas/efeitos dos fármacos , Fenantridinas/química , Fenantridinas/toxicidade , Fosfolipases/metabolismo , Virulência/efeitos dos fármacos
13.
Artigo em Inglês | MEDLINE | ID: mdl-31293987

RESUMO

Candida albicans is the major pathogen isolated from nosocomial bloodstream infections, leading to higher mortality rates. Thus, due to its clinical relevance, studies aiming to understand host-pathogen interactions in C. albicans infection are necessary. Therefore, we performed proteomic analysis using a murine model of serial systemic infection by C. albicans to evaluate possible changes in the protein profile of the pathogen over time. Firstly, we observed a reduction in the median survival time of infected animals with increasing passage number, suggesting a higher pathogenicity acquired during repeated infections. By LC-MS/MS, it was possible to obtain protein profiles from the wild-type strain (WT) and compare them to proteins extracted from Candida cells recovered from infected tissues during passages one, three, and four (P1, P3, and P4). We obtained 56, 29, and 97 proteins in P1, P3, P4, respectively, all varying in abundance. Regarding biological processes, the majority of proteins were related to carbohydrate metabolism, stress responses and amino acid metabolism. The proteins were also categorized according to their potential role in virulence traits, such as biofilm production, yeast-to-hyphae transition, phenotypic switching, proteins related to stress responses, and uncharacterized proteins. Therefore, serial infection in combination with proteomic approach enabled us to deepen the existing knowledge about host-pathogen interactions.


Assuntos
Candida albicans/metabolismo , Candidíase/metabolismo , Proteínas Fúngicas/metabolismo , Interações Hospedeiro-Patógeno/fisiologia , Proteômica , Aminoácidos/metabolismo , Animais , Biofilmes , Candida albicans/patogenicidade , Candidíase/microbiologia , Metabolismo dos Carboidratos , Cromatografia Líquida , Modelos Animais de Doenças , Feminino , Camundongos , Camundongos Endogâmicos BALB C , Espectrometria de Massas em Tandem , Virulência , Fatores de Virulência/metabolismo
14.
PLoS One ; 14(7): e0219715, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31295309

RESUMO

Gene manipulation and epitope tagging are essential tools for understanding the molecular function of specific genes. The opportunistic human pathogen Candida albicans is a diploid fungus that utilizes a non-canonical genetic code. Since selection markers available in this organism are scarce, several tools based on recyclable markers have been developed for gene disruption, such as the Clox system. This system relies on the Cre recombinase, which recycles selection markers flanked by loxP sites with high efficiency, facilitating single marker or multi-marker recycling. However, PCR-based modules for epitope tagging, such the pFA-modules, mainly use limited non-recyclable auxotrophic markers. To solve this problem, we have used a Gibson assembly strategy to construct a set of new plasmids where the auxotrophic markers of the pFA vectors were swapped with five recyclable marker modules of the Clox system, enhancing the versatility of the pFA plasmids. This new toolkit, named pFA-Clox, is composed of 36 new vectors for gene disruption and epitope tagging (GFP, 3xGFP, mCherry, 3xHA, 5xmyc and TAP). These plasmids contain the dominant NAT1 marker, as well as URA3, HIS1 and ARG4 cassettes, thereby permitting functional analysis of laboratory strains as well as clinical isolates of C. albicans. In summary, we have adapted the Clox system to the pFA-backbone vectors. Thus, the set of primers used for the amplification of previously published pFA modules can also be utilized in this new pFA-Clox system. Therefore, this new toolkit harbors the advantages of both systems, allowing accelerated gene modification strategies that could reduce time and costs in strain construction for C. albicans.


Assuntos
Candida albicans/genética , Epitopos/genética , Técnicas Genéticas , Transformação Genética , Candida albicans/imunologia , Candida albicans/patogenicidade , Mapeamento de Epitopos/métodos , Epitopos/imunologia , Vetores Genéticos/genética , Proteínas de Fluorescência Verde/genética , Humanos , Integrases/genética , Plasmídeos/genética
15.
BMC Infect Dis ; 19(1): 570, 2019 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-31262263

RESUMO

BACKGROUND: Kodamaea ohmeri is a yeast is frequently mistaken for Candida, which belongs to the same family. This micro-organism has been reported to cause life-threatening infections in humans. CASE PRESENTATION: A 81-year-old woman developed a severe fungemic pulmonary infection due to Kodamaea ohmeri that was identified from bronchoalveolar fluid and blood cultures, which is unusual in immunocompetent patients. Because K. ohmeri was first wrongly identified as Candida albicans, the patient inadequately received caspofungin, which was clinically ineffective, especially as the strain was resistant to echinocandins. Clinical cure was obtained after treatment was switched to voriconazole. CONCLUSIONS: An increasing number of serious infections due to K. ohmeri has been reported in the literature, but the correct identification of this micro-organism remains difficult.


Assuntos
Fungemia/tratamento farmacológico , Fungemia/microbiologia , Saccharomycetales/patogenicidade , Idoso de 80 Anos ou mais , Antifúngicos/uso terapêutico , Candida albicans/patogenicidade , Erros de Diagnóstico , Farmacorresistência Fúngica/efeitos dos fármacos , Equinocandinas/uso terapêutico , Feminino , Humanos , Testes de Sensibilidade Microbiana , Saccharomycetales/efeitos dos fármacos , Voriconazol/uso terapêutico
16.
Curr Pharm Biotechnol ; 20(12): 1055-1063, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31333126

RESUMO

OBJECTIVE: The present study was aimed to evaluate the effect of the aqueous extract of Tinospora cordifolia (AETC) against cyclophosphamide-induced immunosuppression and systemic Candida albicans infection in a murine model. METHODS: The protective effect of AETC against cyclophosphamide-induced leukopenia was evaluated by quantitative and qualitative analysis of the leukocytes. The immune-stimulating potential of AETC on macrophages was assessed by determining the levels of secreted cytokines. To determine the direct antifungal activity, AETC or fluconazole was administered to C. albicans infected mice. The efficacy of treatment was assessed by determining the survival rate, kidney fungal burden, the organ index and liver inflammation parameters. RESULTS: Cyclophosphamide administration resulted in substantial depletion of leukocytes, whereas AETC treatment induced the recovery of leukocytes in cyclophosphamide-injected mice. Moreover, AETC treatment of macrophages resulted in enhanced secretion of IFN-γ, TNF-α and IL-1ß. C. albicans infected mice treated with AETC at the doses of 50 and 100 mg/kg exhibited 40% and 60% survival rate, whereas the mice treated with fluconazole at a dose of 50 mg/kg showed 20% survival rate. Like survival data, the fungal load was found to be the lowest in the kidney tissues of mice treated with AETC at a dose of 100 mg/kg. Interestingly, mice infected with C. albicans demonstrated improvement in the organ indices and liver functioning after AETC treatment. CONCLUSION: These results suggest that AETC may potentially be used to rejuvenate the weakened immune system and eliminate systemic candidiasis in mice.


Assuntos
Antifúngicos/uso terapêutico , Candidíase/tratamento farmacológico , Candidíase/imunologia , Fluconazol/uso terapêutico , Extratos Vegetais/uso terapêutico , Tinospora/química , Animais , Candida albicans/efeitos dos fármacos , Candida albicans/patogenicidade , Ciclofosfamida/farmacologia , Hospedeiro Imunocomprometido , Imunossupressores/farmacologia , Rim/efeitos dos fármacos , Rim/microbiologia , Macrófagos/efeitos dos fármacos , Macrófagos/imunologia , Camundongos , Extratos Vegetais/isolamento & purificação , Fator de Necrose Tumoral alfa/imunologia
17.
Pak J Pharm Sci ; 32(3 (Supplementary)): 1185-1192, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-31303589

RESUMO

Candida albicans was considered as the principal cause of opportunistic candidiasis but nowadays, neglected non-albicans Candida (NAC) species are evolving as more virulent and drug resistant strains. This research was intended to assess pervasiveness of candidiasis mainly caused by NAC species in Karachi city. A total of 562 clinical isolates of Candida spp. collected during the period of one year were identified by microscopic as well as morphological (germ tube formation, characteristics on CHROM agar and Corn meal agar) and Biochemical (sugar assimilation and fermentation) characteristics. Doubtful species were further identified by using Remel RapIDTM yeast plus kit. The results were statistically analyzed by SPSS 16.0 version software. Isolated strains of candida revealed slight predominance of C. albicans (54.5%) over non- albicans Candida species (45.5%). Among NAC species, C. tropicalis and C. glabrata were isolated as the predominant species. These clinical species were procured mainly from urine samples of females (73.7%) of age group 20-30 years. No significant correlations exist between Candida species and their months of isolation as well as their isolation from different districts of Karachi. Emergence of NAC species may predict an upcoming threat in health care facilities and hence, require prompt management and accurate identification to suggest empirical antifungal therapy.


Assuntos
Candida/isolamento & purificação , Candida/patogenicidade , Candidíase/epidemiologia , Candidíase/microbiologia , Adulto , Distribuição por Idade , Idoso , Candida albicans/isolamento & purificação , Candida albicans/patogenicidade , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Doenças Negligenciadas , Paquistão/epidemiologia , Estações do Ano , Urina/microbiologia , Adulto Jovem
18.
mSphere ; 4(3)2019 06 19.
Artigo em Inglês | MEDLINE | ID: mdl-31217300

RESUMO

J. Christian Pérez studies the interplay between Candida albicans and the mammalian host. In this mSphere of Influence article, he reflects on how "Systematic screens of a Candida albicans homozygous deletion library decouple morphogenetic switching and pathogenicity" (S. M. Noble, S. French, L. A. Kohn, V. Chen, et al., Nat Genet 42:590-598, 2010, https://doi.org/10.1038/ng.605) provided tools and a blueprint for open-ended genetic screens in an organism that had been a challenge for genetic manipulation.


Assuntos
Candida albicans/genética , Candida albicans/patogenicidade , Virulência , Animais , Camundongos
19.
mSphere ; 4(3)2019 06 19.
Artigo em Inglês | MEDLINE | ID: mdl-31217302

RESUMO

Teresa O'Meara works in the field of functional genomics of Candida albicans, with a focus on host-pathogen interactions. In this mSphere of Influence article, she reflects on how papers entitled "Systematic Screens of a Candida albicans Homozygous Deletion Library Decouple Morphogenetic Switching and Pathogenicity" by S. M. Noble, S. French, L. A. Kohn, V. Chen, and A. D. Johnson (Nat Genet 42:590-598, 2010, https://doi.org/10.1038/ng.605) and "Exploring Quantitative Yeast Phenomics with Single-Cell Analysis of DNA Damage Foci" by E. B. Styles et al. (Cell Syst 3:264-277.e10, 2016, https://doi.org/10.1016/j.cels.2016.08.008) impacted her research and thinking through pioneering functional genomic screens. These articles show the power of combining defined mutant libraries with screens for interesting phenotypes to understand new biology.


Assuntos
Candida albicans/genética , Candida albicans/patogenicidade , Dano ao DNA , Genômica/métodos , Análise de Célula Única
20.
PLoS One ; 14(6): e0218037, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31170229

RESUMO

Candida albicans, a species of fungi, can thrive in diverse niches of its mammalian hosts; it is a normal resident of the GI tract and mucosal surfaces but it can also enter the bloodstream and colonize internal organs causing serious disease. The ability of C. albicans to thrive in these different host environments has been attributed, at least in part, to its ability to assume different morphological forms. In this work, we examine one such morphological change known as white-opaque switching. White cells are the default state of C. albicans, and most animal studies have been carried out exclusively with white cells. Here, we compared the proliferation of white and opaque cells in two murine models of infection and also monitored, using specially constructed strains, switching between the two states in the host. We found that white cells outcompeted opaque cells in many niches; however, we show for the first time that in some organs (specifically, the heart and spleen), opaque cells competed favorably with white cells and, when injected on their own, could colonize these organs. In environments where the introduced white cells outcompeted the introduced opaque cells, we observed high rates of opaque-to-white switching. We did not observe white-to-opaque switching in any of the niches we examined.


Assuntos
Candida albicans/citologia , Candida albicans/patogenicidade , Candidíase/microbiologia , Especificidade de Órgãos , Pigmentação , Animais , Candidíase/patologia , Contagem de Colônia Microbiana , Modelos Animais de Doenças , Corantes Fluorescentes/metabolismo , Intestinos/microbiologia , Intestinos/patologia , Rim/microbiologia , Rim/patologia , Camundongos
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