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1.
Microb Pathog ; 188: 106537, 2024 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-38211834

RESUMEN

Paracoccidioidomycosis (PCM) is a systemic mycosis caused by Paracoccidioides spp. The interaction mediated by the presence of adhesins on the fungal surface and receptors in the extracellular matrix of the host, as well as the biofilm formation, is essential in its pathogenesis. Adhesins such as gp43, enolase, GAPDH (glyceraldehyde-3-phosphate dehydrogenase), and 14-3-3 have been demonstrated in the Paracoccidioides brasiliensis (Pb18) strain and recognized as necessary in the fungus-host interaction. The Pb 18 strain silenced to 14-3-3 showed changes in morphology, virulence, and adhesion capacity. The study aimed to evaluate the role of adhesin 14-3-3 in P. brasiliensis biofilm formation and the differential expression of genes related to adhesins, comparing planktonic and biofilm forms. The presence of biofilm was also verified in sutures in vitro and in vivo. The silenced strain (Pb14-3-3 aRNA) was compared with the wild type Pb18, determining the differential metabolic activity between the strains by the XTT reduction assay; the biomass by violet crystal and the polysaccharides by safranin, even as morphological differences by microscopic techniques. Differential gene expression for adhesins was also analyzed, comparing the relative expression of these in planktonic and biofilm forms at different times. The results suggested that the silencing of 14-3-3 protein altered the ability to form biofilm and its metabolism. The quantity of biomass was similar in both strains; however, the formation of exopolymeric substances and polysaccharide material was lower in the silenced strain. Our results showed increased expression of enolase, GAPDH, and 14-3-3 genes in the first periods of biofilm formation in the Pb18 strain. In contrast, the silenced strain showed a lower expression of these genes, indicating that gene silencing can influence the expression of other genes and be involved in the biofilm formation of P. brasiliensis. In vitro and in vivo assays using sutures confirmed this yeast's ability to form biofilm and may be implicated in the pathogenesis of paracoccidioidomycosis.


Asunto(s)
Paracoccidioides , Paracoccidioidomicosis , Paracoccidioides/genética , Proteínas 14-3-3/genética , Proteínas 14-3-3/metabolismo , Gliceraldehído-3-Fosfato Deshidrogenasas , Biopelículas , Adhesinas Bacterianas/metabolismo , Fosfopiruvato Hidratasa/genética
2.
Altern Lab Anim ; 52(1): 60-68, 2024 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-38061994

RESUMEN

The Brazilian National Network of Alternative Methods (RENAMA), which is linked to the Ministry of Science, Technology and Innovation, is currently comprised of 51 laboratories from CROs, academia, industry and government. RENAMA's aim is to develop and validate new approach methodologies (NAMs), as well as train researchers and disseminate information on their use - thus reducing Brazilian, and consequently Latin American, dependence on external technology. Moreover, it promotes the adoption of NAMs by educators and trained researchers, as well as the implementation of good laboratory practice (GLP) and the use of certified products. The RENAMA network started its activities in 2012, and was originally comprised of three central laboratories - the National Institute of Metrology, Quality and Technology (INMETRO); the National Institute of Quality Control in Health (INCQS); and the National Brazilian Biosciences Laboratory (LNBio) - and ten associated laboratories. In 2022, RENAMA celebrated its 10th anniversary, a milestone commemorated by the organisation of a meeting attended by different stakeholders, including the RENAMA-associated laboratories, academia, non-governmental organisations and industry. Ninety-six participants attended the meeting, held on 26 May 2022 in Balneário Camboriú, SC, Brazil, as part of the programme of the XXIII Brazilian Congress of Toxicology 2022. Significant moments of the RENAMA were remembered, and new goals and discussion themes were established. The lectures highlighted recent innovations in the toxicological sciences that have translated into the assessment of consumer product safety through the use of human-relevant NAMs instead of the use of existing animal-based approaches. The challenges and opportunities in accepting such practices for regulatory purposes were also presented and discussed.


Asunto(s)
Aniversarios y Eventos Especiales , Laboratorios , Animales , Humanos , Brasil
3.
Chem Biodivers ; 20(8): e202300329, 2023 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-37402173

RESUMEN

Varronia curassavica displays anti-inflammatory, antiulcerogenic, and antioxidant activities. Herein, we employed new UHPLC -UV green chromatographic methods for the analysis of in vitro antioxidant and anti-inflammatory activities of V. curassavica and its embryotoxicity in Zebrafish. Cordialin A, brickellin, and artemetin were purified from the ethanol (EtOH) extract of V. Curassavica leaves and identified using spectrometric techniques. In line with Green Analytical Chemistry principles, the proposed UHPLC methods involve the use of ethanol as organic modifier with low mobile phase consumption, and without sample pretreatment (OLE-UHPLC-UV). The application of the Agree and HPLC-EAT tools for greenness assessment yielded this pattern: HPLC-UV (reference)

Asunto(s)
Antioxidantes , Extractos Vegetales , Animales , Extractos Vegetales/química , Antioxidantes/química , Pez Cebra , Antiinflamatorios/farmacología , Hojas de la Planta/química , Etanol
4.
Antimicrob Agents Chemother ; 65(12): e0090421, 2021 11 17.
Artículo en Inglés | MEDLINE | ID: mdl-34516241

RESUMEN

Cryptococcosis is associated with high rates of morbidity and mortality, especially in AIDS patients. Its treatment is carried out by combining amphotericin B and azoles or flucytosine, which causes unavoidable toxicity issues in the host. Thus, the urgency in obtaining new antifungals drives the search for antimicrobial peptides (AMPs). This study aimed to extend the understanding of the mechanism of action of an AMP analog from wasp peptide toxins, MK58911-NH2, on Cryptococcus neoformans. We also evaluated if MK58911-NH2 can act on cryptococcal cells in macrophages, biofilms, and an immersion zebrafish model of infection. Finally, we investigated the structure-antifungal action and the toxicity relationship of MK58911-NH2 fragments and a derivative of this peptide (MH58911-NH2). The results demonstrated that MK58911-NH2 did not alter the fluorescence intensity of the cell wall-binding dye calcofluor white or the capsule-binding dye 18b7 antibody-fluorescein isothiocyanate (FITC) in C. neoformans but rather reduced the number and size of fungal cells. This activity reduced the fungal burden of C. neoformans in both macrophages and zebrafish embryos as well as within biofilms. Three fragments of the MK58911-NH2 peptide showed no activity against Cryptococcus and not toxicity in lung cells. The derivative peptide MH58911-NH2, in which the lysine residues of MK58911-NH2 were replaced by histidines, reduced the activity against extracellular and intracellular C. neoformans. On the other hand, it was active against biofilms and showed reduced toxicity. In summary, these results showed that peptide MK58911-NH2 could be a promising agent against cryptococcosis. This work also opens a perspective for the verification of the antifungal activity of other derivatives.


Asunto(s)
Antifúngicos/farmacología , Péptidos Antimicrobianos/farmacología , Cryptococcus neoformans , Animales , Biopelículas , Criptococosis/tratamiento farmacológico , Cryptococcus neoformans/efectos de los fármacos , Humanos , Macrófagos/microbiología , Pruebas de Sensibilidad Microbiana , Pez Cebra
5.
Mem Inst Oswaldo Cruz ; 115: e200238, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-32756740

RESUMEN

BACKGROUND Paracoccidioides spp. causes paracoccidioidomycosis (PCM), an important and frequent systemic mycosis that occurs in Latin America. The infectious process begins with contact between the fungus and lung cells, and the molecular pattern of this interaction is currently poorly understood. MicroRNAs (miRNAs) are small non-coding RNAs that regulate the gene expression in many biological processes, including in the infections. OBJECTIVE This study aimed to analyse the expression of miRNAs in lung cells as response to infection by Paracoccidioides spp. METHODS A quantitative real-time polymerase chain reaction (RT-qPCR) based screening was employed to verify differentially expressed miRNAs in human lung cells infected with three different species; Paracoccidioides lutzii, Paracoccidioides americana, and Paracoccidioides brasiliensis. Furthermore, the in silico predictions of target genes and pathways for miRNAs were obtained. FINDINGS The results showed that miRNAs identified in the lung cells were different according to the species studied. However, based on the predicted targets, the potential signaling pathways regulated by miRNAs are common and related to adhesion, actin cytoskeleton rearrangement, apoptosis, and immune response mediated by T cells and TGF-ß. MAIN CONCLUSIONS In summary, this study showed the miRNAs pattern of epithelial cells in response to infection by Paracoccidioides species and the potential role of these molecules in the regulation of key pathogenesis mechanisms of PCM.


Asunto(s)
MicroARNs , Paracoccidioides , Paracoccidioidomicosis , Humanos , América Latina , Pulmón/citología , MicroARNs/metabolismo , Paracoccidioides/patogenicidad , Reacción en Cadena en Tiempo Real de la Polimerasa
6.
Artículo en Inglés | MEDLINE | ID: mdl-31451502

RESUMEN

The available antifungal therapeutic arsenal is limited. The search for alternative drugs with fewer side effects and new targets remains a major challenge. Decyl gallate (G14) is a derivative of gallic acid with a range of biological activities and broad-spectrum antifungal activity. Previously, our group demonstrated the promising anti-Paracoccidioides activity of G14. In this work, to evaluate the antifungal characteristics of G14 for Paracoccidioides lutzii, a chemical-genetic interaction analysis was conducted on a Saccharomyces cerevisiae model. N-glycosylation and/or the unfolded protein response pathway was identified as a high-confidence process for drug target prediction. The overactivation of unfolded protein response (UPR) signaling was confirmed using this model with IRE1/ATF6/PERK genes tagged with green fluorescent protein (GFP). In P. lutzii, this prediction was confirmed by the low activity of glycosylated enzymes [α-(1,3)-glucanase, N-acetyl-ß-d-glucosaminidase (NAGase), and α-(1,4)-amylase], by hyperexpression of genes involved with the UPR and glycosylated enzymes, and by the reduction in the amounts of glycosylated proteins and chitin. All of these components are involved in fungal cell wall integrity and are dependent on the N-glycosylation process. This loss of integrity was confirmed by the reduction in mitochondrial activity, impaired budding, enhancement of wall permeability, and a decrease in viability. These events led to a reduction of the ability of fungi to adhere on human lung epithelial cells (A549) in vitro Therefore, G14 may have an important role in balancing the inflammatory reaction caused by fungal infection, without interfering with the microbicidal activity of nitric oxide. This work provides new information on the activity of G14, a potential anti-Paracoccidioides compound.


Asunto(s)
Antifúngicos/farmacología , Ácido Gálico/farmacología , Glicosilación/efectos de los fármacos , Paracoccidioides/efectos de los fármacos , Células A549 , Línea Celular Tumoral , Pared Celular/efectos de los fármacos , Pared Celular/metabolismo , Quitina/metabolismo , Proteínas Fúngicas/metabolismo , Proteínas Fluorescentes Verdes/metabolismo , Humanos , Pulmón/microbiología , Mitocondrias/efectos de los fármacos , Mitocondrias/metabolismo , Paracoccidioides/metabolismo , Paracoccidioidomicosis/tratamiento farmacológico , Paracoccidioidomicosis/metabolismo , Paracoccidioidomicosis/microbiología , Saccharomyces cerevisiae/efectos de los fármacos , Saccharomyces cerevisiae/metabolismo , Respuesta de Proteína Desplegada/efectos de los fármacos
7.
Med Mycol ; 57(7): 900-904, 2019 Oct 01.
Artículo en Inglés | MEDLINE | ID: mdl-30476159

RESUMEN

The Paracoccidioides brasiliensis strain downregulated the expression of adhesin Pb14-3-3 (Pb14-3-3 aRNA) was evaluated in a murine model of paracoccidioidomycosis (PCM). Pb14-3-3 aRNA displays attenuated virulence and triggered the formation of fewer granulomas by lowering the fungal burden in the lungs. Additionally, the Pb14-3-3 aRNA showed more elongated yeast cells and less ability to induce pneumocytes apoptosis in vitro. Our results show that 14-3-3 is an important virulence factor in P. brasiliensis-induced pulmonary infection.


Asunto(s)
Proteínas 14-3-3/genética , Proteínas Fúngicas/genética , Paracoccidioides/genética , Paracoccidioides/patogenicidad , Factores de Virulencia/genética , Células Epiteliales Alveolares/microbiología , Células Epiteliales Alveolares/patología , Animales , Apoptosis/genética , Modelos Animales de Enfermedad , Expresión Génica , Pulmón/citología , Pulmón/microbiología , Ratones , Ratones Endogámicos BALB C , Paracoccidioidomicosis/microbiología
8.
Med Mycol ; 56(3): 374-377, 2018 Apr 01.
Artículo en Inglés | MEDLINE | ID: mdl-28637229

RESUMEN

Paracoccidioidomycosis (PCM) is a fungal disease restricted to Latin countries, and its etiologic agents derive from the Paracoccidioides genus. Attenuation or loss of virulence in Paracoccidioides spp. following successive subculturing has been described. However, virulence can be recovered by passage in mammalian host. In this study, the recovery of adhesion of P. brasiliensis through passage in mice was compared to that in the insect Galleria mellonella. Analysis of in vitro fungal-host cell interaction, gene expression of adhesins, and analysis of the survival curves revealed that Galleria mellonella is useful for the reactivation of P. brasiliensis adhesion.


Asunto(s)
Adhesinas Bacterianas/metabolismo , Mariposas Nocturnas/microbiología , Paracoccidioides/patogenicidad , Paracoccidioidomicosis/microbiología , Paracoccidioidomicosis/mortalidad , Factores de Virulencia/metabolismo , Adhesinas Bacterianas/genética , Animales , Modelos Animales de Enfermedad , Perfilación de la Expresión Génica , Regulación de la Expresión Génica/fisiología , Masculino , Ratones , Ratones Endogámicos BALB C , Paracoccidioides/genética , Paracoccidioidomicosis/patología , Tasa de Supervivencia , Virulencia/genética , Factores de Virulencia/genética
9.
Molecules ; 23(10)2018 Sep 20.
Artículo en Inglés | MEDLINE | ID: mdl-30241381

RESUMEN

This study evaluated the influence of the extract of Eugenia uniflora in adhesion to human buccal epithelial cells (HBEC) biofilm formation and cell surface hydrophobicity (CSH) of Candida spp. isolated from the oral cavity of kidney transplant patients. To evaluate virulence attributes in vitro, nine yeasts were grown in the presence and absence of 1000 µg/mL of the extract. Adhesion was quantified using the number of Candida cells adhered to 150 HBEC determined by optical microscope. Biofilm formation was evaluated using two methodologies: XTT (2,3-bis(2-methoxy-4-nitro-5-sulfophenyl)-2H-tetrazolium-5-carboxanilide) and crystal violet assay, and further analyzed by electronic scan microscopy. CSH was quantified with the microbial adhesion to hydrocarbons test. We could detect that the extract of E. uniflora was able to reduce adhesion to HBEC and CSH for both Candida albicans and non-Candida albicansCandida species. We also observed a statistically significant reduced ability to form biofilms in biofilm-producing strains using both methods of quantification. However, two highly biofilm-producing strains of Candida tropicalis had a very large reduction in biofilm formation. This study reinforces the idea that besides growth inhibition, E. uniflora may interfere with the expression of some virulence factors of Candida spp. and may be possibly applied in the future as a novel antifungal agent.


Asunto(s)
Antifúngicos/farmacología , Candida albicans/efectos de los fármacos , Extractos Celulares/química , Eugenia/química , Antifúngicos/química , Biopelículas/efectos de los fármacos , Candida albicans/patogenicidad , Adhesión Celular/efectos de los fármacos , Extractos Celulares/farmacología , Células Epiteliales/química , Células Epiteliales/efectos de los fármacos , Humanos , Interacciones Hidrofóbicas e Hidrofílicas/efectos de los fármacos , Trasplante de Riñón/efectos adversos , Boca/efectos de los fármacos , Mucosa Bucal/química , Propiedades de Superficie/efectos de los fármacos , Factores de Virulencia/química
10.
Med Mycol ; 55(8): 890-894, 2017 Nov 01.
Artículo en Inglés | MEDLINE | ID: mdl-28339963

RESUMEN

Apoptosis is considered an escape mechanism from the host immune system for the fungus Paracoccidioides spp, and it serves as a vehicle for entry into macrophages without stimulating microbicidal activities. Recently, gp43 of P. brasiliensis was demonstrated to be involved in this process. Therefore, as a new therapeutic alternative, it is very important to study compounds that could reduce the modulation of the induction of apoptosis caused by this fungus. Decyl gallate (G14) is a known antifungal compound, and we decided to investigate its anti-apoptotic properties. Our results demonstrate that G14 was effective against apoptosis induced by gp43, as observed in epithelial cells, and led to a reduction in DNA damage, Bak down-regulation and Bcl-2 up-regulation. Together, these data show that G14 presents promising anti-apoptotic activity.


Asunto(s)
Antifúngicos/farmacología , Apoptosis/efectos de los fármacos , Glicoproteínas/fisiología , Paracoccidioides/fisiología , Células A549 , Células Epiteliales Alveolares/microbiología , Células Epiteliales Alveolares/patología , Antígenos Fúngicos/metabolismo , Línea Celular , Daño del ADN/efectos de los fármacos , Proteínas Fúngicas/metabolismo , Regulación de la Expresión Génica/efectos de los fármacos , Genes bcl-2/genética , Humanos , Paracoccidioidomicosis/fisiopatología , Proteína Destructora del Antagonista Homólogo bcl-2/genética
11.
FEMS Yeast Res ; 16(7)2016 11.
Artículo en Inglés | MEDLINE | ID: mdl-27634774

RESUMEN

Paracoccidioides spp., which are temperature-dependent dimorphic fungi, are responsible for the most prevalent human systemic mycosis in Latin America, the paracoccidioidomycosis. The aim of this study was to characterise the involvement of elongation factor Tu (EF-Tu) in Paracoccidioides brasiliensis-host interaction. Adhesive properties were examined using recombinant PbEF-Tu proteins and the respective polyclonal anti-rPbEF-Tu antibody. Immunogold analysis demonstrated the surface location of EF-Tu in P. brasiliensis. Moreover, PbEF-Tu was found to bind to fibronectin and plasminogen by enzyme-linked immunosorbent assay, and it was determined that the binding to plasminogen is at least partly dependent on lysine residues and ionic interactions. To verify the participation of EF-Tu in the interaction of P. brasiliensis with pneumocytes, we blocked the respective protein with an anti-rPbEF-Tu antibody and evaluated the consequences on the interaction index by flow cytometry. During the interaction, we observed a decrease of 2- and 3-fold at 8 and 24 h, respectively, suggesting the contribution of EF-Tu in fungal adhesion/invasion.


Asunto(s)
Interacciones Huésped-Patógeno , Paracoccidioides/enzimología , Factor Tu de Elongación Peptídica/metabolismo , Factores de Virulencia/metabolismo , Células Epiteliales Alveolares/microbiología , Adhesión Celular , Línea Celular , Fibronectinas/metabolismo , Humanos , Proteínas de la Membrana/metabolismo , Paracoccidioides/fisiología , Plasminógeno/metabolismo , Unión Proteica
12.
BMC Microbiol ; 15: 256, 2015 Nov 04.
Artículo en Inglés | MEDLINE | ID: mdl-26537993

RESUMEN

BACKGROUND: 14-3-3 proteins comprise a family of eukaryotic multifunctional proteins involved in several cellular processes. The Pb14-3-3 of Paracoccidioides brasiliensis seems to play an important role in the Paracoccidioides-host interaction. Paracoccidioides brasiliensis is an etiological agent of paracoccidioidomycosis, which is a systemic mycosis that is endemic in Latin America. In the initial steps of the infection, Paracoccidioides spp. synthetizes adhesins that allow it to adhere and invade host cells. Therefore, the aim of this work was to perform a functional analysis of Pb14-3-3 using Saccharomyces cerevisiae as a model. RESULTS: The functional analysis of Pb14-3-3 was performed in S. cerevisiae, and it was found that Pb14-3-3 partially complemented S. cerevisiae proteins Bmh1p and Bmh2p, which are recognized as two yeast 14-3-3 homologues. When we evaluated the adhesion profile of S. cerevisiae transformants, Pb14-3-3 acted as an adhesin in S. cerevisiae; however, Bmh1p did not show this function. The influence of Pb14-3-3 in S. cerevisiae ergosterol pathway was also evaluated and our results showed that Pb14-3-3 up-regulates genes involved in ergosterol biosynthesis. CONCLUSIONS: Our data showed that Pb14-3-3 was able to partially complement Bmh1p and Bmh2p proteins in S. cerevisiae; however, we suggest that Pb14-3-3 has a differential role as an adhesin. In addition, Pb-14-3-3 may be involved in Paracoccidioides spp. ergosterol biosynthesis which makes it an interest as a therapeutic target.


Asunto(s)
Proteínas 14-3-3/metabolismo , Proteínas Fúngicas/metabolismo , Paracoccidioides/genética , Saccharomyces cerevisiae/genética , Proteínas 14-3-3/genética , Clonación Molecular , Ergosterol/metabolismo , Proteínas Fúngicas/genética , Perfilación de la Expresión Génica , Regulación Fúngica de la Expresión Génica , Prueba de Complementación Genética , Paracoccidioides/metabolismo , Saccharomyces cerevisiae/metabolismo , Proteínas de Saccharomyces cerevisiae/metabolismo
13.
BMC Microbiol ; 14: 302, 2014 Dec 13.
Artículo en Inglés | MEDLINE | ID: mdl-25609357

RESUMEN

BACKGROUND: Paracoccidioides spp is a fungi genus and the agent of paracoccidioidomycosis. The strategies of infection used by these pathogens involve the expression of proteins related to adaptation to the host, particularly regarding the uptake of micronutrients. This study analyzed the adhesion of Paracoccidioides lutzii during conditions of copper (Cu) and iron (Fe) deprivation, while also evaluating the proteins expressed in conditions of Cu depletion in the presence of four extracellular matrix (ECM) components (laminin, fibronectin and types I and IV collagen). RESULTS: We cultured the P. lutzii in a chemically defined media without Cu and Fe. The fungus was then placed in contact with different ECM components and adhesion was evaluated. A significant increase in binding to all ECM components was observed when the fungus was cultured without Cu; which might be related to some adhesins expression. A proteomic assay was developed and revealed 39 proteins expressed that are involved in processes such as virulence, protein synthesis, metabolism, energy, transcription, transport, stress response and the cell cycle when the fungus was interacting with the ECM components. The up-regulated expression of two important adhesins, enolase and 14-3-3, was observed at the fungal cell wall during the interaction with the ECM components, indicating the role of these proteins in the Paracoccidioides-host interaction. CONCLUSIONS: This study is important for determining prospective proteins that may be involved in the interaction of Paracoccidioides with a host. Understanding the adaptive response to different growth conditions, elucidating the processes of adhesion and cell invasion, and identifying the proteins that are differentially expressed during the fungus-host interaction may help elucidate mechanisms used for survival and growth of Paracoccidioides in various human tissues.


Asunto(s)
Adhesión Celular , Cobre/metabolismo , Proteínas de la Matriz Extracelular/metabolismo , Expresión Génica/efectos de los fármacos , Paracoccidioides/fisiología , Animales , Medios de Cultivo/química , Proteínas Fúngicas/análisis , Hierro/metabolismo , Paracoccidioides/genética , Paracoccidioides/crecimiento & desarrollo , Paracoccidioides/metabolismo , Proteoma/análisis , Conejos
14.
Eukaryot Cell ; 12(7): 1033-8, 2013 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-23709181

RESUMEN

The MAT1-1 and MAT1-2 idiomorphs associated with the MAT1 locus of Histoplasma capsulatum were identified by PCR. A total of 28 fungal isolates, 6 isolates from human clinical samples and 22 isolates from environmental (infected bat and contaminated soil) samples, were studied. Among the 14 isolates from Mexico, 71.4% (95% confidence interval [95% CI], 48.3% to 94.5%) were of the MAT1-2 genotype, whereas 100% of the isolates from Brazil were of the MAT1-1 genotype. Each MAT1 idiomorphic region was sequenced and aligned, using the sequences of the G-217B (+ mating type) and G-186AR (- mating type) strains as references. BLASTn analyses of the MAT1-1 and MAT1-2 sequences studied correlated with their respective + and - mating type genotypes. Trees were generated by the maximum likelihood (ML) method to search for similarity among isolates of each MAT1 idiomorph. All MAT1-1 isolates originated from Brazilian bats formed a well-defined group; three isolates from Mexico, the G-217B strain, and a subgroup encompassing all soil-derived isolates and two clinical isolates from Brazil formed a second group; last, one isolate (EH-696P) from a migratory bat captured in Mexico formed a third group of the MAT1-1 genotype. The MAT1-2 idiomorph formed two groups, one of which included two H. capsulatum isolates from infected bats that were closely related to the G-186AR strain. The other group was formed by two human isolates and six isolates from infected bats. Concatenated ML trees, with internal transcribed spacer 1 (ITS1) -5.8S-ITS2 and MAT1-1 or MAT1-2 sequences, support the relatedness of MAT1-1 or MAT1-2 isolates. H. capsulatum mating types were associated with the geographical origin of the isolates, and all isolates from Brazil correlated with their environmental sources.


Asunto(s)
Genes del Tipo Sexual de los Hongos/genética , Sitios Genéticos/genética , Variación Genética , Histoplasma/genética , Histoplasma/aislamiento & purificación , Secuencia de Bases , Brasil , ADN Intergénico/genética , Humanos , Funciones de Verosimilitud , México , Datos de Secuencia Molecular
15.
J Fungi (Basel) ; 10(5)2024 May 20.
Artículo en Inglés | MEDLINE | ID: mdl-38786716

RESUMEN

Histoplasma capsulatum causes a fungal respiratory disease. Some studies suggest that the fungus requires zinc to consolidate the infection. This study aimed to investigate the influence of zinc and the metal chelator TPEN on the growth of Histoplasma in planktonic and biofilm forms. The results showed that zinc increased the metabolic activity, cell density, and cell viability of planktonic growth. Similarly, there was an increase in biofilm metabolic activity but no increase in biomass or extracellular matrix production. N'-N,N,N,N-tetrakis-2-pyridylmethylethane-1,2 diamine (TPEN) dramatically reduced the same parameters in the planktonic form and resulted in a decrease in metabolic activity, biomass, and extracellular matrix production for the biofilm form. Therefore, the unprecedented observations in this study highlight the importance of zinc ions for the growth, development, and proliferation of H. capsulatum cells and provide new insights into the role of metal ions for biofilm formation in the dimorphic fungus Histoplasma, which could be a potential therapeutic strategy.

16.
Front Microbiol ; 15: 1354140, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38516014

RESUMEN

The genus Paracoccidioides includes Paracoccidioides lutzii and the Paracoccidioides brasiliensis complex, which comprises four phylogenetic species. A key feature distinguishing planktonic growth from biofilm is the presence of a 3D extracellular matrix (ECM). Therefore, in this study, we analyzed biofilm formation in different species of Paracoccidioides yeast phase, characterized the structural elements of the matrix of P. brasiliensis (Pb18), P. lutzii (Pl01 and 8334) and P. restrepiensis (339 and 192) and evaluated the expression of glucan genes, according to the stage of biofilm evolution for P. brasiliensis. The strains were cultivated in planktonic and biofilm form for 24-144 h. The fungi biomass and metabolic activity were determined by crystal violet and tetrazolium salt reduction (XTT) tests and colony-forming unit (CFU) by plating. The biofilm structure was designed using scanning electron microscopy and confocal laser scanning microscopy techniques. The extracellular matrix of P. brasiliensis and P. lutzii biofilms was extracted by sonication, and polysaccharides, proteins, and extracellular DNA (eDNA) were quantified. The RNA was extracted with the Trizol® reagent and quantified; then, the cDNA was synthesized to analyze the enolase expression, 14-3-3, FKS1, AGS1, GEL3, and KRE6 genes by real-time PCR. All strains of Paracoccidioides studied form a biofilm with more significant metabolic activity and biomass values in 144 h. The extracellular matrix of P. brasiliensis and P. lutzii had a higher content of polysaccharides in their composition, followed by proteins and eDNA in smaller quantities. The P. brasiliensis biofilm kinetics of formation showed greater expression of genes related to glucan's synthesis and its delivery to the external environment in addition adhesins during the biofilm's adhesion, initiation, and maturation. The GEL3 and enolase genes increased in expression within 24 h and during the biofilm maturation period, there was an increase in 14-3-3, AGS1, and FKS1. Furthermore, at 144 h, there was a decrease in KRE6 expression and an increase in GEL3. This study highlights the potential for biofilm formation for three species of Paracoccidioides and the main components of the extracellular matrix that can contribute to a better understanding of biofilm organization.

17.
J Control Release ; 365: 744-758, 2024 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-38072085

RESUMEN

Amphotericin B (AmB) is the gold standard for antifungal drugs. However, AmB systemic administration is restricted because of its side effects. Here, we report AmB loaded in natural rubber latex (NRL), a sustained delivery system with low toxicity, which stimulates angiogenesis, cell adhesion and accelerates wound healing. Physicochemical characterizations showed that AmB did not bind chemically to the polymeric matrix. Electronic and topographical images showed small crystalline aggregates from AmB crystals on the polymer surface. About 56.6% of AmB was released by the NRL in 120 h. However, 33.6% of this antifungal was delivered in the first 24 h due to the presence of AmB on the polymer surface. The biomaterial's excellent hemo- and cytocompatibility with erythrocytes and human dermal fibroblasts (HDF) confirmed its safety for dermal wound application. Antifungal assay against Candida albicans showed that AmB-NRL presented a dose-dependent behavior with an inhibition halo of 30.0 ± 1.0 mm. Galleria mellonella was employed as an in vivo model for C. albicans infection. Survival rates of 60% were observed following the injection of AmB (0.5 mg.mL-1) in G. mellonella larvae infected by C. albicans. Likewise, AmB-NRL (0.5 mg.mL-1) presented survival rates of 40%, inferring antifungal activity against fungus. Thus, NRL adequately acts as an AmB-sustained release matrix, which is an exciting approach, since this antifungal is toxic at high concentrations. Our findings suggest that AmB-NRL is an efficient, safe, and reasonably priced ($0.15) dressing for the treatment of cutaneous fungal infections.


Asunto(s)
Candidiasis , Infección de Heridas , Humanos , Anfotericina B , Antifúngicos/química , Vendajes , Candida albicans , Candidiasis/tratamiento farmacológico , Látex , Pruebas de Sensibilidad Microbiana , Infección de Heridas/tratamiento farmacológico
18.
Antimicrob Agents Chemother ; 57(5): 2417-21, 2013 05.
Artículo en Inglés | MEDLINE | ID: mdl-23478969

RESUMEN

Biofilms have been observed in the fluid pathways of hemodialysis machines. The impacts of four biocides used for the disinfection of hemodialysis systems were tested against Candida parapsilosis sensu stricto and Candida orthopsilosis biofilms generated by isolates obtained from a hydraulic circuit that were collected in a hemodialysis unit. Acetic acid was shown to be the most effective agent against Candida biofilms. Strategies for effective disinfection procedures used for hemodialysis systems should also seek to kill and inhibit biofilms.


Asunto(s)
Ácido Acético/farmacología , Antifúngicos/farmacología , Biopelículas/efectos de los fármacos , Candida/efectos de los fármacos , Desinfectantes/farmacología , Riñones Artificiales/microbiología , Biopelículas/crecimiento & desarrollo , Candida/crecimiento & desarrollo , Unidades de Hemodiálisis en Hospital , Humanos , Peróxido de Hidrógeno/farmacología , Ácido Peracético/farmacología , Hipoclorito de Sodio/farmacología
19.
Med Mycol ; 51(7): 759-64, 2013 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-23566224

RESUMEN

Paracoccidioidomycosis (PCM) is a chronic granulomatous disease caused by the dimorphic fungus Paracoccidioides brasiliensis, endemic in Latin America. P. brasiliensis has been observed in epithelial cells in vivo and in vitro, as well as within the macrophages. The identification of the mechanism by which it survives within the host cell is fertile ground for the discovery of its pathogenesis since this organism has the ability to induce its own endocytosis in epithelial cells and most likely in macrophages. The study of the expression of endocytic proteins pathway and co-localization of microorganisms enable detection of the mechanism by which microorganisms survive within the host cell. The aim of this study was to evaluate the expression of the endocytic protein EEA1 (early endosome antigen 1) in macrophages infected with P. brasiliensis. For detection of EEA1, three different techniques were employed: immunofluorescence, real-time polymerase chain reaction (PCR) and immunoblotting. In the present study, decreased expression of EEA1 as well as the rearrangement of the actin was observed when the fungus was internalized, confirming that the input mechanism of the fungus in macrophages occurs through phagocytosis.


Asunto(s)
Regulación de la Expresión Génica , Interacciones Huésped-Patógeno , Macrófagos/química , Macrófagos/microbiología , Paracoccidioides/crecimiento & desarrollo , Paracoccidioides/inmunología , Proteínas de Transporte Vesicular/análisis , Actinas/metabolismo , Animales , Línea Celular , Técnica del Anticuerpo Fluorescente , Perfilación de la Expresión Génica , Immunoblotting , Ratones , Fagocitosis , Reacción en Cadena en Tiempo Real de la Polimerasa , Proteínas de Transporte Vesicular/genética
20.
Pharmaceutics ; 15(1)2023 Jan 12.
Artículo en Inglés | MEDLINE | ID: mdl-36678893

RESUMEN

Invasive fungal infections increase mortality and morbidity rates worldwide. The treatment of these infections is still limited due to the low bioavailability and toxicity, requiring therapeutic monitoring, especially in the most severe cases. Voriconazole is an azole widely used to treat invasive aspergillosis, other hyaline molds, many dematiaceous molds, Candida spp., including those resistant to fluconazole, and for infections caused by endemic mycoses, in addition to those that occur in the central nervous system. However, despite its broad activity, using voriconazole has limitations related to its non-linear pharmacokinetics, leading to supratherapeutic doses and increased toxicity according to individual polymorphisms during its metabolism. In this sense, nanotechnology-based drug delivery systems have successfully improved the physicochemical and biological aspects of different classes of drugs, including antifungals. In this review, we highlighted recent work that has applied nanotechnology to deliver voriconazole. These systems allowed increased permeation and deposition of voriconazole in target tissues from a controlled and sustained release in different routes of administration such as ocular, pulmonary, oral, topical, and parenteral. Thus, nanotechnology application aiming to delivery voriconazole becomes a more effective and safer therapeutic alternative in the treatment of fungal infections.

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