Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 27
Filtrar
Más filtros












Base de datos
Intervalo de año de publicación
1.
Cureus ; 15(11): e49021, 2023 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-38111399

RESUMEN

Tuberculous spondylodiscitis (Pott's spine) is a complex extrapulmonary manifestation of tuberculosis (TB) that poses significant medical challenges, characterized by vertebral destruction affecting approximately 2% of all TB cases. The management of this condition involves a multidisciplinary approach, with surgical intervention indicated for specific cases, including those with neurological complications, spinal instability, and kyphosis. We report a case of a 49-year-old female with a confirmed diagnosis of tuberculous spondylodiscitis who had undergone eight months of tuberculostatic therapy. She was referred for neurosurgical consultation due to uncontrollable axial pain, despite favorable clinical and imaging responses, which had rendered her immobile for six months. Imaging revealed a complete collapse of the L5 vertebral body, and a complementary dual x-ray absorptiometry (DEXA) scan demonstrated severe osteoporosis. A two-stage surgical approach was chosen to address her condition, involving corpectomy through an anterior approach, followed by lumbopelvic stabilization. Postoperative recovery was uneventful, with progressive improvement in pain and mobility. This case highlights the challenges of managing tuberculous spondylodiscitis and underscores the significance of early detection to prevent complications like severe osteoporosis. In this case, delayed referral for surgery following an extended period of immobility added complexity to an already difficult case. The severe osteoporosis, with a t-score of -5.7, had a substantial impact on surgical planning, leading to a more robust approach to arthrodesis with substantial lumbopelvic instrumentation in order to mitigate the risks associated with implant failure. This case shows that timely intervention and a comprehensive multidisciplinary approach are essential for the effective management of tuberculous spondylodiscitis, especially in cases complicated by severe osteoporosis.

2.
Nucleic Acids Res ; 51(D1): D785-D791, 2023 01 06.
Artículo en Inglés | MEDLINE | ID: mdl-36350610

RESUMEN

YEASTRACT+ (http://yeastract-plus.org/) is a tool for the analysis, prediction and modelling of transcription regulatory data at the gene and genomic levels in yeasts. It incorporates three integrated databases: YEASTRACT (http://yeastract-plus.org/yeastract/), PathoYeastract (http://yeastract-plus.org/pathoyeastract/) and NCYeastract (http://yeastract-plus.org/ncyeastract/), focused on Saccharomyces cerevisiae, pathogenic yeasts of the Candida genus, and non-conventional yeasts of biotechnological relevance. In this release, YEASTRACT+ offers upgraded information on transcription regulation for the ten previously incorporated yeast species, while extending the database to another pathogenic yeast, Candida auris. Since the last release of YEASTRACT+ (January 2020), a fourth database has been integrated. CommunityYeastract (http://yeastract-plus.org/community/) offers a platform for the creation, use, and future update of YEASTRACT-like databases for any yeast of the users' choice. CommunityYeastract currently provides information for two Saccharomyces boulardii strains, Rhodotorula toruloides NP11 oleaginous yeast, and Schizosaccharomyces pombe 972h-. In addition, YEASTRACT+ portal currently gathers 304 547 documented regulatory associations between transcription factors (TF) and target genes and 480 DNA binding sites, considering 2771 TFs from 11 yeast species. A new set of tools, currently implemented for S. cerevisiae and C. albicans, is further offered, combining regulatory information with genome-scale metabolic models to provide predictions on the most promising transcription factors to be exploited in cell factory optimisation or to be used as novel drug targets. The expansion of these new tools to the remaining YEASTRACT+ species is ongoing.


Asunto(s)
Programas Informáticos , Transcripción Genética , Levaduras , Bases de Datos Genéticas , Regulación Fúngica de la Expresión Génica , Redes Reguladoras de Genes , Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/metabolismo , Factores de Transcripción/genética , Factores de Transcripción/metabolismo , Levaduras/genética
3.
Microb Cell ; 9(11): 174-189, 2022 Nov 07.
Artículo en Inglés | MEDLINE | ID: mdl-36448018

RESUMEN

The emergence of drug resistance significantly hampers the treatment of human infections, including those caused by fungal pathogens such as Candida species. Candida glabrata ranks as the second most common cause of candidiasis worldwide, supported by rapid acquisition of resistance to azole and echinocandin antifungals frequently prompted by single nucleotide polymorphisms (SNPs) in resistance associated genes, such as PDR1 (azole resistance) or FKS1/2 (echinocandin resistance). To determine the frequency of polymorphisms and genome rearrangements as the possible genetic basis of C. glabrata drug resistance, we assessed genomic variation across 94 globally distributed isolates with distinct resistance phenotypes, whose sequence is deposited in GenBank. The genomes of three additional clinical isolates were sequenced, in this study, including two azole resistant strains that did not display Gain-Of-Function (GOF) mutations in the transcription factor encoding gene PDR1. Genomic variations in susceptible isolates were used to screen out variants arising from genome diversity and to identify variants exclusive to resistant isolates. More than half of the azole or echinocandin resistant isolates do not possess exclusive polymorphisms in PDR1 or FKS1/2, respectively, providing evidence of alternative genetic basis of antifungal resistance. We also identified copy number variations consistently affecting a subset of chromosomes. Overall, our analysis of the genomic and phenotypic variation across isolates allowed to pinpoint, in a genome-wide scale, genetic changes enriched specifically in antifungal resistant strains, which provides a first step to identify additional determinants of antifungal resistance. Specifically, regarding the newly sequenced strains, a set of mutations/genes are proposed to underlie the observed unconventional azole resistance phenotype.

4.
Commun Biol ; 5(1): 1118, 2022 10 21.
Artículo en Inglés | MEDLINE | ID: mdl-36271293

RESUMEN

The increasing prevalence of candidosis caused by Candida glabrata is related to its ability to acquire azole resistance. Although azole resistance mechanisms are well known, the mechanisms for azole import into fungal cells have remained obscure. In this work, we have characterized two hexose transporters in C. glabrata and further investigate their role as potential azole importers. Three azole susceptible C. glabrata clinical isolates were evolved towards azole resistance and the acquired resistance phenotype was found to be independent of CgPDR1 or CgERG11 mutations. Through whole-genome sequencing, CgHXT4/6/7 was found to be mutated in the three evolved strains, when compared to their susceptible parents. CgHxt4/6/7 and the 96% identical CgHxt6/7 were found to confer azole susceptibility and increase azole accumulation in C. glabrata cells, strikingly rescuing the susceptibility phenotype imposed by CgPDR1 deletion, while the identified loss-of-function mutation in CgHXT4/6/7, leads to increased azole resistance. In silico docking analysis shows that azoles display a strong predicted affinity for the glucose binding site of CgHxt4/6/7. Altogether, we hypothesize that hexose transporters, such as CgHxt4/6/7 and CgHxt6/7, may constitute a family of azole importers, involved in clinical drug resistance in fungal pathogens, and constituting promising targets for improved antifungal therapy.


Asunto(s)
Azoles , Candida glabrata , Candida glabrata/genética , Azoles/farmacología , Azoles/uso terapéutico , Farmacorresistencia Fúngica/genética , Antifúngicos/farmacología , Glucosa , Evolución Molecular , Hexosas
5.
Methods Mol Biol ; 2477: 419-437, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35524130

RESUMEN

The ability of living organisms to survive changing environmental conditions is dependent on the implementation of gene expression programs underlying adaptation and fitness. Transcriptional networks can be exceptionally complex: a single transcription factor (TF) may regulate hundreds of genes, and multiple TFs may regulate a single gene-depending on the environmental conditions. Moreover, the same TF may act as an activator or repressor in distinct conditions. In turn, the activity of regulators themselves may be dependent on other TFs, as well as posttranscriptional and posttranslational regulation. These traits greatly contribute to the intricate networks governing gene expression programs.In this chapter, a step-by-step guide of how to use PathoYeastract, one of several interconnecting databases within the YEASTRACT+ portal, to predict gene and genomic regulation in Candida spp. is provided. PathoYeastract contains a set of analysis tools to study regulatory associations in human pathogenic yeasts, enabling: (1) the prediction and ranking of TFs that contribute to the regulation of individual genes; (2) the prediction of the genes regulated by a given TF; and (3) the prediction and ranking of TFs that regulate a genome-wide transcriptional response. These capabilities are illustrated, respectively, with the analysis of: (1) the TF network controlling the C. glabrata QDR2 gene; (2) the regulon controlled by the C. glabrata TF Rpn4; and (3) the regulatory network controlling the C. glabrata transcriptome-wide changes induced upon exposure to the antifungal drug fluconazole. The newest potentialities of this information system are explored, including cross-species network comparison. The results are discussed considering the performed queries and integrated with the current knowledge on the biological data for each case-study.


Asunto(s)
Candida , Genómica , Candida/genética , Candida/metabolismo , Regulación Fúngica de la Expresión Génica , Redes Reguladoras de Genes , Genómica/métodos , Regulón , Factores de Transcripción/genética , Factores de Transcripción/metabolismo
6.
J Fungi (Basel) ; 8(1)2022 Jan 07.
Artículo en Inglés | MEDLINE | ID: mdl-35050001

RESUMEN

The prevalence of antifungal resistance in Candida glabrata, especially against azole drugs, results in difficult-to-treat and potentially life-threatening infections. Understanding the molecular basis of azole resistance in C. glabrata is crucial to designing more suitable therapeutic strategies. In this study, the role of the transcription factor encoded by ORF CAGL0B03421g, here denominated as CgMar1 (Multiple Azole Resistance 1), in azole susceptibility was explored. Using RNA-sequencing, CgMar1 was found to regulate 337 genes under fluconazole stress, including several related to lipid biosynthesis pathways. In this context, CgMar1 and its target CgRSB1, encoding a predicted sphingoid long-chain base efflux transporter, were found to contribute to plasma membrane sphingolipid incorporation and membrane permeability, decreasing fluconazole accumulation. CgMar1 was found to associate with the promoter of CgRSB1, which contains two instances of the CCCCTCC consensus, found to be required for CgRSB1 activation during fluconazole stress. Altogether, a regulatory pathway modulating azole susceptibility in C. glabrata is proposed, resulting from what appears to be a neofunctionalization of a Hap1-like transcription factor.

7.
Commun Biol ; 4(1): 886, 2021 07 20.
Artículo en Inglés | MEDLINE | ID: mdl-34285314

RESUMEN

Candida glabrata is an opportunistic pathogen that adheres to human epithelial mucosa and forms biofilm to cause persistent infections. In this work, Single-cell Force Spectroscopy (SCFS) was used to glimpse at the adhesive properties of C. glabrata as it interacts with clinically relevant surfaces, the first step towards biofilm formation. Following a genetic screening, RNA-sequencing revealed that half of the entire transcriptome of C. glabrata is remodeled upon biofilm formation, around 40% of which under the control of the transcription factors CgEfg1 and CgTec1. Using SCFS, it was possible to observe that CgEfg1, but not CgTec1, is necessary for the initial interaction of C. glabrata cells with both abiotic surfaces and epithelial cells, while both transcription factors orchestrate biofilm maturation. Overall, this study characterizes the network of transcription factors controlling massive transcriptional remodelling occurring from the initial cell-surface interaction to mature biofilm formation.


Asunto(s)
Biopelículas/crecimiento & desarrollo , Candida glabrata/fisiología , Genoma Fúngico , Factores de Transcripción/genética , Candida glabrata/genética , Factores de Transcripción/metabolismo
8.
Int J Mol Sci ; 22(3)2021 Jan 29.
Artículo en Inglés | MEDLINE | ID: mdl-33573089

RESUMEN

Candida glabrata is an emerging fungal pathogen whose success depends on its ability to resist antifungal drugs but also to thrive against host defenses. In this study, the predicted multidrug transporter CgTpo4 (encoded by ORF CAGL0L10912g) is described as a new determinant of virulence in C. glabrata, using the infection model Galleria mellonella. The CgTPO4 gene was found to be required for the C. glabrata ability to kill G. mellonella. The transporter encoded by this gene is also necessary for antimicrobial peptide (AMP) resistance, specifically against histatin-5. Interestingly, G. mellonella's AMP expression was found to be strongly activated in response to C. glabrata infection, suggesting AMPs are a key antifungal defense. CgTpo4 was also found to be a plasma membrane exporter of polyamines, especially spermidine, suggesting that CgTpo4 is able to export polyamines and AMPs, thus conferring resistance to both stress agents. Altogether, this study presents the polyamine exporter CgTpo4 as a determinant of C. glabrata virulence, which acts by protecting the yeast cells from the overexpression of AMPs, deployed as a host defense mechanism.


Asunto(s)
Candida glabrata/genética , Candidiasis/microbiología , Proteínas Fúngicas/genética , Proteínas Asociadas a Resistencia a Múltiples Medicamentos/genética , Poliaminas/farmacología , Proteínas Citotóxicas Formadoras de Poros/farmacología , Antifúngicos/metabolismo , Antifúngicos/farmacología , Candida glabrata/efectos de los fármacos , Candida glabrata/metabolismo , Candida glabrata/patogenicidad , Candidiasis/tratamiento farmacológico , Candidiasis/metabolismo , Farmacorresistencia Fúngica , Proteínas Fúngicas/metabolismo , Regulación Fúngica de la Expresión Génica , Genes Fúngicos , Histatinas/metabolismo , Histatinas/farmacología , Humanos , Proteínas Asociadas a Resistencia a Múltiples Medicamentos/metabolismo , Poliaminas/metabolismo , Proteínas Citotóxicas Formadoras de Poros/metabolismo , Virulencia
9.
Genomics ; 113(2): 530-539, 2021 03.
Artículo en Inglés | MEDLINE | ID: mdl-33482324

RESUMEN

Although Saccharomyces cerevisiae and S. cerevisiae var. boulardii share more than 95% genome sequence homology, only S. cerevisiae var. boulardii displays probiotic activity. In this study, the transcriptomic differences exhibited by S. cerevisiae and S. cerevisiae var. boulardii in intestinal like medium were evaluated. S. cerevisiae was found to display stress response overexpression, consistent with higher ability of S. cerevisiae var. boulardii to survive within the human host, while S. cerevisiae var. boulardii exhibited transcriptional patterns associated with probiotic activity, suggesting increased acetate biosynthesis. Resorting to the creation of a S. cerevisiae var. boulardii genomic database within Yeastract+, a possible correlation between loss or gain of transcription factor binding sites in S. cerevisiae var. boulardii promoters and the transcriptomic pattern is discussed. This study suggests that S. cerevisiae var. boulardii probiotic activity, when compared to S. cerevisiae, relies, at least partially, on differential expression regulation, based on promoter variability.


Asunto(s)
Polimorfismo Genético , Probióticos , Regiones Promotoras Genéticas , Saccharomyces cerevisiae/genética , Transcriptoma , Regulación Fúngica de la Expresión Génica , Proteínas de Saccharomyces cerevisiae/metabolismo , Factores de Transcripción/metabolismo , Activación Transcripcional
10.
Virulence ; 11(1): 1522-1538, 2020 12.
Artículo en Inglés | MEDLINE | ID: mdl-33135521

RESUMEN

Candida glabrata is a prominent pathogenic yeast which exhibits a unique ability to survive the harsh environment of host immune cells. In this study, we describe the role of the transcription factor encoded by the gene CAGL0F09229g, here named CgTog1 after its Saccharomyces cerevisiae ortholog, as a new determinant of C. glabrata virulence. Interestingly, Tog1 is absent in the other clinically relevant Candida species (C. albicans, C. parapsilosis, C. tropicalis, C. auris), being exclusive to C. glabrata. CgTog1 was found to be required for oxidative stress resistance and for the modulation of reactive oxygen species inside C. glabrata cells. Also, CgTog1 was observed to be a nuclear protein, whose activity up-regulates the expression of 147 genes and represses 112 genes in C. glabrata cells exposed to H2O2, as revealed through RNA-seq-based transcriptomics analysis. Given the importance of oxidative stress response in the resistance to host immune cells, the effect of CgTOG1 expression in yeast survival upon phagocytosis by Galleria mellonella hemocytes was evaluated, leading to the identification of CgTog1 as a determinant of yeast survival upon phagocytosis. Interestingly, CgTog1 targets include many whose expression changes in C. glabrata cells after engulfment by macrophages, including those involved in reprogrammed carbon metabolism, glyoxylate cycle and fatty acid degradation. In summary, CgTog1 is a new and specific regulator of virulence in C. glabrata, contributing to oxidative stress resistance and survival upon phagocytosis by host immune cells.


Asunto(s)
Candida glabrata/genética , Candida glabrata/patogenicidad , Proteínas Fúngicas/genética , Regulación Fúngica de la Expresión Génica , Estrés Oxidativo/genética , Factores de Transcripción/genética , Factores de Virulencia/genética , Animales , Candida glabrata/efectos de los fármacos , Hemocitos/microbiología , Peróxido de Hidrógeno/farmacología , Mariposas Nocturnas/citología , Mariposas Nocturnas/microbiología , Fagocitosis , Saccharomyces cerevisiae/genética , Factores de Transcripción/metabolismo , Virulencia/genética
11.
J Fungi (Basel) ; 6(2)2020 Jun 04.
Artículo en Inglés | MEDLINE | ID: mdl-32512834

RESUMEN

Saccharomyces boulardii is a probiotic yeast often used for the treatment of GI tract disorders such as diarrhea symptoms. It is genetically close to the model yeast Saccharomyces cerevisiae and its classification as a distinct species or a S. cerevisiae variant has long been discussed. Here, we review the main genetic divergencies between S. boulardii and S. cerevisiae as a strategy to uncover the ability to adapt to the host physiological conditions by the probiotic. S. boulardii does possess discernible phenotypic traits and physiological properties that underlie its success as probiotic, such as optimal growth temperature, resistance to the gastric environment and viability at low pH. Its probiotic activity has been elucidated as a conjunction of multiple pathways, ranging from improvement of gut barrier function, pathogen competitive exclusion, production of antimicrobial peptides, immune modulation, and trophic effects. This review summarizes the participation of S. boulardii in these mechanisms and the multifactorial nature by which this yeast modulates the host microbiome and intestinal function.

12.
Artículo en Inglés | MEDLINE | ID: mdl-32571817

RESUMEN

The ability to acquire azole resistance is an emblematic trait of the fungal pathogen Candida glabrata Understanding the molecular basis of azole resistance in this pathogen is crucial for designing more suitable therapeutic strategies. This study shows that the C. glabrata transcription factor (TF) CgRpn4 is a determinant of azole drug resistance. RNA sequencing during fluconazole exposure revealed that CgRpn4 regulates the expression of 212 genes, activating 80 genes and repressing, likely in an indirect fashion, 132 genes. Targets comprise several proteasome and ergosterol biosynthesis genes, including ERG1, ERG2, ERG3, and ERG11 The localization of CgRpn4 to the nucleus increases upon fluconazole stress. Consistent with a role in ergosterol and plasma membrane homeostasis, CgRpn4 is required for the maintenance of ergosterol levels upon fluconazole stress, which is associated with a role in the upkeep of cell permeability and decreased intracellular fluconazole accumulation. We provide evidence that CgRpn4 directly regulates ERG11 expression through the TTGCAAA binding motif, reinforcing the relevance of this regulatory network in azole resistance. In summary, CgRpn4 is a new regulator of the ergosterol biosynthesis pathway in C. glabrata, contributing to plasma membrane homeostasis and, thus, decreasing azole drug accumulation.


Asunto(s)
Candida glabrata , Fluconazol , Factores de Transcripción , Antifúngicos/farmacología , Candida glabrata/genética , Candida glabrata/metabolismo , Membrana Celular/metabolismo , Farmacorresistencia Fúngica/genética , Ergosterol , Fluconazol/farmacología , Proteínas Fúngicas/genética , Proteínas Fúngicas/metabolismo , Regulación Fúngica de la Expresión Génica , Permeabilidad , Factores de Transcripción/genética , Factores de Transcripción/metabolismo
13.
Nucleic Acids Res ; 48(D1): D642-D649, 2020 01 08.
Artículo en Inglés | MEDLINE | ID: mdl-31586406

RESUMEN

The YEASTRACT+ information system (http://YEASTRACT-PLUS.org/) is a wide-scope tool for the analysis and prediction of transcription regulatory associations at the gene and genomic levels in yeasts of biotechnological or human health relevance. YEASTRACT+ is a new portal that integrates the previously existing YEASTRACT (http://www.yeastract.com/) and PathoYeastract (http://pathoyeastract.org/) databases and introduces the NCYeastract (Non-Conventional Yeastract) database (http://ncyeastract.org/), focused on the so-called non-conventional yeasts. The information in the YEASTRACT database, focused on Saccharomyces cerevisiae, was updated. PathoYeastract was extended to include two additional pathogenic yeast species: Candida parapsilosis and Candida tropicalis. Furthermore, the NCYeastract database was created, including five biotechnologically relevant yeast species: Zygosaccharomyces baillii, Kluyveromyces lactis, Kluyveromyces marxianus, Yarrowia lipolytica and Komagataella phaffii. The YEASTRACT+ portal gathers 289 706 unique documented regulatory associations between transcription factors (TF) and target genes and 420 DNA binding sites, considering 247 TFs from 10 yeast species. YEASTRACT+ continues to make available tools for the prediction of the TFs involved in the regulation of gene/genomic expression. In this release, these tools were upgraded to enable predictions based on orthologous regulatory associations described for other yeast species, including two new tools for cross-species transcription regulation comparison, based on multi-species promoter and TF regulatory network analyses.


Asunto(s)
Biología Computacional/métodos , Bases de Datos Genéticas , Regulación Fúngica de la Expresión Génica , Genoma Fúngico , Genómica , Levaduras/genética , Sitios de Unión , Candida tropicalis/genética , Redes Reguladoras de Genes , Kluyveromyces/genética , Filogenia , Regiones Promotoras Genéticas , Saccharomyces cerevisiae/genética , Programas Informáticos , Especificidad de la Especie , Factores de Transcripción/genética , Transcripción Genética , Yarrowia/genética , Zygosaccharomyces/genética
14.
Microbiol Resour Announc ; 8(35)2019 Aug 29.
Artículo en Inglés | MEDLINE | ID: mdl-31467089

RESUMEN

Here, we report the draft genome sequences of three Candida glabrata clinical isolates, 040, 044, and OL152. The isolates were recovered from patients admitted to Centro Hospitalar de S. João (CHSJ) in Porto, Portugal. Isolates 040 and 044 were taken from blood samples, while isolate OL152 was collected from urine.

15.
Int J Mol Sci ; 20(9)2019 May 11.
Artículo en Inglés | MEDLINE | ID: mdl-31083555

RESUMEN

Candida albicans and Candida glabrata are the two most prevalent etiologic agents of candidiasis worldwide. Although both are recognized as pathogenic, their choice of virulence traits is highly divergent. Indeed, it appears that these different approaches to fungal virulence may be equally successful in causing human candidiasis. In this review, the virulence mechanisms employed by C. albicans and C. glabrata are analyzed, with emphasis on the differences between the two systems. Pathogenesis features considered in this paper include dimorphic growth, secreted enzymes and signaling molecules, and stress resistance mechanisms. The consequences of these traits in tissue invasion, biofilm formation, immune system evasion, and macrophage escape, in a species dependent manner, are discussed. This review highlights the observation that C. albicans and C. glabrata follow different paths leading to a similar outcome. It also highlights the lack of knowledge on some of the specific mechanisms underlying C. glabrata pathogenesis, which deserve future scrutiny.


Asunto(s)
Candida albicans/patogenicidad , Candida glabrata/patogenicidad , Animales , Biopelículas/crecimiento & desarrollo , Candida albicans/inmunología , Candida albicans/fisiología , Candida glabrata/inmunología , Candida glabrata/fisiología , Interacciones Huésped-Patógeno/inmunología , Humanos , Evasión Inmune , Virulencia/inmunología
16.
Microb Cell ; 6(3): 142-159, 2019 Feb 08.
Artículo en Inglés | MEDLINE | ID: mdl-30854392

RESUMEN

Infections by the pathogenic yeasts Candida albicans and Candida glabrata are among the most common fungal diseases. The success of these species as human pathogens is contingent on their ability to resist antifungal therapy and thrive within the human host. C. glabrata is especially resilient to azole antifungal treatment, while C. albicans is best known for its wide array of virulence features. The core mechanisms that underlie antifungal resistance and virulence in these pathogens has been continuously addressed, but the investigation on how such mechanisms evolve according to each environment is scarcer. This review aims to explore current knowledge on micro-evolution experiments to several treatment and host-associated conditions in C. albicans and C. glabrata. The analysis of adaptation strategies that evolve over time will allow to better understand the mechanisms by which Candida species are able to achieve stable phenotypes in real-life scenarios, which are the ones that should constitute the most interesting drug targets.

17.
Prog Mol Subcell Biol ; 58: 155-193, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-30911893

RESUMEN

Candida glabrata is the second most common cause of candidemia worldwide and its prevalence has continuously increased over the last decades. C. glabrata infections are especially worrisome in immunocompromised patients, resulting in serious systemic infections, associated to high mortality rates. Intrinsic resistance to azole antifungals, widely used drugs in the clinical setting, and the ability to efficiently colonize the human host and medical devices, withstanding stress imposed by the immune system, are thought to underlie the emergence of C. glabrata. There is a clear clinical need to understand drug and stress resistance in C. glabrata. The increasing prevalence of multidrug resistant isolates needs to be addressed in order to overcome the decrease of viable therapeutic strategies and find new therapeutic targets. Likewise, the understanding of the mechanisms underlying its impressive ability thrive under oxidative, nitrosative, acidic and metabolic stresses, is crucial to design drugs that target these pathogenesis features. The study of the underlying mechanisms that translate C. glabrata plasticity and its competence to evade the immune system, as well as survive host stresses to establish infection, will benefit from extensive scrutiny. This chapter provides a review on the contribution of genome-wide studies to uncover clinically relevant drug resistance and stress response mechanisms in the human pathogenic yeast C. glabrata.


Asunto(s)
Candida glabrata/efectos de los fármacos , Candida glabrata/genética , Candidemia/microbiología , Farmacorresistencia Fúngica/genética , Genoma Fúngico/efectos de los fármacos , Genoma Fúngico/genética , Estrés Fisiológico/efectos de los fármacos , Estrés Fisiológico/genética , Antifúngicos/farmacología , Azoles/farmacología , Candida glabrata/patogenicidad , Candidemia/tratamiento farmacológico , Farmacorresistencia Fúngica/efectos de los fármacos , Genómica , Humanos
18.
Artículo en Inglés | MEDLINE | ID: mdl-30348666

RESUMEN

Candida glabrata is an emerging fungal pathogen. Its increased prevalence is associated with its ability to rapidly develop antifungal drug resistance, particularly to azoles. In order to unravel new molecular mechanisms behind azole resistance, a transcriptomics analysis of the evolution of a C. glabrata clinical isolate (isolate 044) from azole susceptibility to posaconazole resistance (21st day), clotrimazole resistance (31st day), and fluconazole and voriconazole resistance (45th day), induced by longstanding incubation with fluconazole, was carried out. All the evolved strains were found to accumulate lower concentrations of azole drugs than the parental strain, while the ergosterol concentration remained mostly constant. However, only the population displaying resistance to all azoles was found to have a gain-of-function mutation in the C. glabrataPDR1 gene, leading to the upregulation of genes encoding multidrug resistance transporters. Intermediate strains, exhibiting posaconazole/clotrimazole resistance and increased fluconazole/voriconazole MIC levels, were found to display alternative ways to resist azole drugs. Particularly, posaconazole/clotrimazole resistance after 31 days was correlated with increased expression of adhesin genes. This finding led us to identify the Epa3 adhesin as a new determinant of azole resistance. Besides being required for biofilm formation, Epa3 expression was found to decrease the intracellular accumulation of azole antifungal drugs. Altogether, this work provides a glimpse of the transcriptomics evolution of a C. glabrata population toward multiazole resistance, highlighting the multifactorial nature of the acquisition of azole resistance and pointing out a new player in azole resistance.


Asunto(s)
Antifúngicos/farmacología , Azoles/farmacología , Candida glabrata/efectos de los fármacos , Candida glabrata/genética , Farmacorresistencia Fúngica/genética , Candida glabrata/aislamiento & purificación , Clotrimazol/farmacología , Ergosterol/metabolismo , Fluconazol/farmacología , Regulación Fúngica de la Expresión Génica/efectos de los fármacos , Humanos , Proteínas de Transporte de Membrana/genética , Pruebas de Sensibilidad Microbiana , Factores de Transcripción/genética , Transcriptoma/genética , Triazoles/farmacología , Voriconazol/farmacología
19.
Genes (Basel) ; 9(7)2018 Jul 02.
Artículo en Inglés | MEDLINE | ID: mdl-30004464

RESUMEN

Fungal infections caused by Candida, Aspergillus, and Cryptococcus species are an increasing problem worldwide, associated with very high mortality rates. The successful prevalence of these human pathogens is due to their ability to thrive in stressful host niche colonization sites, to tolerate host immune system-induced stress, and to resist antifungal drugs. This review focuses on the key role played by multidrug resistance (MDR) transporters, belonging to the ATP-binding cassette (ABC), and the major facilitator superfamilies (MFS), in mediating fungal resistance to pathogenesis-related stresses. These clearly include the extrusion of antifungal drugs, with C. albicans CDR1 and MDR1 genes, and corresponding homologs in other fungal pathogens, playing a key role in this phenomenon. More recently, however, clues on the transcriptional regulation and physiological roles of MDR transporters, including the transport of lipids, ions, and small metabolites, have emerged, linking these transporters to important pathogenesis features, such as resistance to host niche environments, biofilm formation, immune system evasion, and virulence. The wider view of the activity of MDR transporters provided in this review highlights their relevance beyond drug resistance and the need to develop therapeutic strategies that successfully face the challenges posed by the pleiotropic nature of these transporters.

20.
Nucleic Acids Res ; 46(D1): D348-D353, 2018 01 04.
Artículo en Inglés | MEDLINE | ID: mdl-29036684

RESUMEN

The YEAst Search for Transcriptional Regulators And Consensus Tracking (YEASTRACT-www.yeastract.com) information system has been, for 11 years, a key tool for the analysis and prediction of transcription regulatory associations at the gene and genomic levels in Saccharomyces cerevisiae. Since its last update in June 2017, YEASTRACT includes approximately 163000 regulatory associations between transcription factors (TF) and target genes in S. cerevisiae, based on more than 1600 bibliographic references; it also includes 247 specific DNA binding consensus recognized by 113 TFs. This release of the YEASTRACT database provides new visualization tools to visualize each regulatory network in an interactive fashion, enabling the user to select and observe subsets of the network such as: (i) considering only DNA binding evidence or both DNA binding and expression evidence; (ii) considering only either positive or negative regulatory associations; or (iii) considering only one set of related environmental conditions. A further tool to observe TF regulons is also offered, enabling a clear-cut understanding of the exact meaning of the available data. We believe that with this new version, YEASTRACT will improve its role as an open web resource instrumental for Yeast Biologists and Systems Biology researchers.


Asunto(s)
Bases de Datos Genéticas , Regulación Fúngica de la Expresión Génica , Redes Reguladoras de Genes , Saccharomyces cerevisiae/genética , Transcripción Genética , Regulón , Factores de Transcripción/metabolismo
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA
...