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1.
Braz J Microbiol ; 54(4): 2609-2615, 2023 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-37606863

RESUMEN

INTRODUCTION: Candida tropicalis is a common non-albicans Candida (NAC) species that causes numerous fungal infections. Increasing antifungal resistance to azoles in NAC is becoming a major health problem worldwide; however, in Egypt, almost no data is available regarding fluconazole resistance mechanisms in C. tropicalis. The current study aims to investigate two possible important molecular mechanisms involved in fluconazole resistance in C. tropicalis isolates. MATERIALS: Fifty-four clinical C. tropicalis isolates were included. Identification and antifungal susceptibility profiles of the isolates were carried out using the VITEK 2 compact system. The molecular investigation of fluconazole resistance included the expression of the CDR1 and MDR1 genes by quantitative real-time RT-PCR as well as the sequence analysis of the ERG11 gene. RESULTS: Antifungal susceptibility testing identified 30 fluconazole-non-susceptible isolates. Statistically, CDR1 gene expression in fluconazole-non-susceptible isolates was significantly higher than that in fluconazole-susceptible isolates, with MDR1 gene expression levels that were similar in both non-susceptible and susceptible isolates. Sequence analysis of the ERG11 gene of 26 fluconazole-resistant isolates identified two missense mutations: A395T (Y132F) and G1390A (G464S). CONCLUSIONS: This study has highlighted the role of overexpression of the CDR1 gene and ERG11 gene mutations in fluconazole non-susceptibility. Further studies in Egypt are required to investigate other possible molecular mechanisms involved in azole resistance.


Asunto(s)
Antifúngicos , Candidiasis , Humanos , Antifúngicos/farmacología , Fluconazol/farmacología , Candida tropicalis/genética , Candida tropicalis/metabolismo , Egipto , Candidiasis/microbiología , Azoles/farmacología , Candida/genética , Candida/metabolismo , Expresión Génica , Farmacorresistencia Fúngica/genética , Pruebas de Sensibilidad Microbiana , Proteínas Fúngicas/genética , Proteínas Fúngicas/metabolismo , Candida albicans/genética
2.
Chem Biol Interact ; 382: 110639, 2023 Sep 01.
Artículo en Inglés | MEDLINE | ID: mdl-37468117

RESUMEN

Lectins are proteins of non-immunological origin with the ability to bind to carbohydrates reversibly. They emerge as an alternative to conventional antifungals, given the ability to interact with carbohydrates in the fungal cell wall inhibiting fungal growth. The lectin from D. violacea (DVL) already has its activity described as anti-candida in some species. Here, we observed the anti-candida effect of DVL on C. albicans, C. krusei and C. parapsilosis and its multiple mechanisms of action toward the yeasts. Additionally, it was observed that DVL induces membrane and cell wall damage and ROS overproduction. DVL was also able to cause an imbalance in the redox system of the cells, interact with ergosterol, inhibit ergosterol biosynthesis, and induce cytochrome c release from the mitochondrial membrane. These results endorse the potential application of DVL in developing a new antifungal drug to fight back against fungal resistance.


Asunto(s)
Dioclea , Lectinas , Lectinas/farmacología , Candida/metabolismo , Dioclea/metabolismo , Lectinas de Plantas/farmacología , Lectinas de Plantas/metabolismo , Antifúngicos/farmacología , Carbohidratos , Semillas/metabolismo , Ergosterol , Candida albicans , Pruebas de Sensibilidad Microbiana
3.
Molecules ; 28(2)2023 Jan 10.
Artículo en Inglés | MEDLINE | ID: mdl-36677748

RESUMEN

Invasive fungal infections represent a public health problem that worsens over the years with the increasing resistance to current antimycotic agents. Therefore, there is a compelling medical need of widening the antifungal drug repertoire, following different methods such as drug repositioning, identification and validation of new molecular targets and developing new inhibitors against these targets. In this work we developed a structure-based strategy for drug repositioning and new drug design, which can be applied to infectious fungi and other pathogens. Instead of applying the commonly accepted off-target criterion to discard fungal proteins with close homologues in humans, the core of our approach consists in identifying fungal proteins with active sites that are structurally similar, but preferably not identical to binding sites of proteins from the so-called "human pharmacolome". Using structural information from thousands of human protein target-inhibitor complexes, we identified dozens of proteins in fungal species of the genera Histoplasma, Candida, Cryptococcus, Aspergillus and Fusarium, which might be exploited for drug repositioning and, more importantly, also for the design of new fungus-specific inhibitors. As a case study, we present the in vitro experiments performed with a set of selected inhibitors of the human mitogen-activated protein kinases 1/2 (MEK1/2), several of which showed a marked cytotoxic activity in different fungal species.


Asunto(s)
Antifúngicos , Micosis , Humanos , Antifúngicos/farmacología , Antifúngicos/metabolismo , Candida/metabolismo , Proteínas Fúngicas/química , Dominio Catalítico , Hongos/metabolismo
4.
Chem Biol Drug Des ; 101(2): 350-363, 2023 02.
Artículo en Inglés | MEDLINE | ID: mdl-36053023

RESUMEN

The high morbidity and mortality rates of Candida infections, especially among immunocompromised patients, are related to the increased resistance rate of these species and the limited therapeutic arsenal. In this context, we evaluated the anti-Candida potential and the cytotoxic profile of eugenol derivatives. Anti-Candida activity was evaluated on C. albicans and C. parapsilosis strains by minimum inhibitory concentration (MIC), scanning electron microscopy (SEM), and molecular docking calculations at the site of the enzyme lanosterol-14-α-demethylase active site, responsible for ergosterol formation. The cytotoxic profile was evaluated in HepG2 cells, in the presence and absence of the metabolizing system (S9 system). The results indicated compounds 1b and 1d as the most active ones. The compounds have anti-Candida activity against both strains with MIC ranging from 50 to 100 µg ml-1 . SEM analyses of 1b and 1d indicated changes in the envelope architecture of both C. albicans and C. parapsilosis like the ones of eugenol and fluconazole, respectively. Docking results of the evaluated compounds indicated a similar binding pattern of fluconazole and posaconazole at the lanosterol-14-α-demethylase binding site. In the presence of the S9 system, compound 1b showed the same cytotoxicity profile as fluconazole (1.08 times) and compound 1d had 1.23 times increase in cytotoxicity. Eugenol and other evaluated compounds showed a significant increase in cytotoxicity. Our results suggest compound 1b as a promising starting point candidate to be used in the design of new anti-Candida agent prototypes.


Asunto(s)
Candida , Fluconazol , Humanos , Candida/metabolismo , Fluconazol/farmacología , Antifúngicos/farmacología , Antifúngicos/química , Eugenol/farmacología , Simulación del Acoplamiento Molecular , Lanosterol , Candida albicans/metabolismo , Pruebas de Sensibilidad Microbiana , Esterol 14-Desmetilasa/metabolismo
5.
Bioprocess Biosyst Eng ; 45(7): 1149-1162, 2022 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-35585433

RESUMEN

Lipases (E.C. 3.1.1.3) have buried active sites and used access tunnels in the transport of substrates and products for biotransformation processes. Computational methods are used to predict the trajectory and energy profile of ligands through these tunnels, and they complement the experimental methodologies because they filter data, optimizing laboratory time and experimental costs. Access tunnels of Burkholderia cepacia lipase (BCL), Candida rugosa lipase (CRL), and porcine pancreas lipase (PPL) and the transport of fatty acids, alcohols and esters through the tunnels were evaluated using the online server CaverWeb V1.0, and server calculation results were compared with experimental data (productivity). BCL showed higher productivity with palmitic acid-C16:0 (4029.95 µmol/h mg); CRL obtained productivity for oleic acid-C18:1 (380.80 µmol/h mg), and PPL achieved productivity for lauric acid-C12:0 (71.27 µmol/h mg). The highest probability of transport for BCL is through the tunnels 1 and 2, for CRL through the tunnel 1, and for PPL through the tunnels 1, 2, 3 and 4. Thus, the best in silico result was the transport of the substrates palmitic acid and ethanol and product ethyl palmitate in tunnel 1 of BCL. This result corroborates with the best result for the productivity data (higher productivity for BCL with palmitic acid-4029.95 µmol/h mg). The combination of in silico evaluation and experimental data gave similar results, demonstrating that in silico approaches are a promising alternative for reducing screening tests and minimizing laboratory time in the bio-catalysis area by identifying the lipases with the greatest reaction potential, as in the case of this proposal.


Asunto(s)
Burkholderia cepacia , Lipasa , Animales , Candida/metabolismo , Lipasa/química , Ácido Oléico , Ácidos Palmíticos , Porcinos
6.
Arch Microbiol ; 204(6): 346, 2022 May 24.
Artículo en Inglés | MEDLINE | ID: mdl-35608680

RESUMEN

Lectins participate in the defense against microorganisms and in signaling the damage caused by pathogens to the cell surface and/or intracellular in plants. This study aims to analyze the antifungal potential of lectins extracted from seeds of Canavalia ensiformis (L.) DC and Canavalia rosea (Sw.) DC, against Candida albicans and Candida tropicalis. The antimicrobial tests were performed by microdilution against Candida spp. The test to verify the combined lectin/fluconazole effect was performed using subinhibitory concentrations of lectins and with antifungal ranging from 0.5 to 512 µg/mL. The ability to inhibit the morphological transition of Candida spp. was evaluated by microcultivation in a moist chamber. The results of the minimum inhibitory concentration revealed no antifungal activity against the tested strains. However, lectins modified the action of fluconazole, reducing the IC50 of the drug against C. albicans. Lectins were also able to discretely modulate the morphological transition of the tested strains.


Asunto(s)
Candida albicans , Candida tropicalis , Antifúngicos/farmacología , Canavalia/metabolismo , Candida/metabolismo , Concanavalina A , Fluconazol/farmacología , Lectinas/farmacología , Pruebas de Sensibilidad Microbiana , Plancton
7.
Chem Biodivers ; 19(3): e202100757, 2022 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-35092349

RESUMEN

Candida species are responsible for causing invasive candidiasis with high mortality rate and their resistance to available antifungal drugs is a major clinical challenge. Biotransformation process of the labdane diterpene ent-labd-8(17)-en-15,18-dioic acid (1) carried out with Cunninghamella elegans afforded five new derivatives (compounds 2-6). Unusual regioselective hydroxylation of the methyl group at the C-20 position of labdane-type diterpene was achieved and all compounds were subjected to cytotoxicity and antifungal evaluations. Compound 1 and its derivatives were not cytotoxic to normal (MCF-10A) and tumor (MCF-7) cell lines. Compounds 2 and 3 exhibited fungistatic activity against all tested Candida strains at lower concentrations than fluconazole. Both compounds also showed the strongest fungicidal activity against C. albicans, which is the most prevalent fungal agent involved in candidemia.


Asunto(s)
Candida , Diterpenos , Antifúngicos/farmacología , Biotransformación , Candida/metabolismo , Cunninghamella , Diterpenos/metabolismo , Diterpenos/farmacología , Fluconazol , Pruebas de Sensibilidad Microbiana
8.
Biotechnol Lett ; 44(1): 89-99, 2022 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-34738223

RESUMEN

OBJECTIVES: To immobilize Candida rugosa lipase in Accurel MP 1000 (CRL-AMP) by physical adsorption in organic medium and apply in the synthesis of wax esters dodecanoyl octadecanoate 1 and hexadecanoyl octadecanoate 2 in a heptane medium, as well as evaluating the stability and recyclability of CRL-AMP in six reaction cycles. RESULTS: The specific activity (Asp) for CRL-AMP was 200 ± 20 U mg-1. Its catalytic activity was 1300 ± 100 U g-1. CRL-AMP was used in the synthesis of esters in heptane medium with a 1:1 acid:alcohol molar ratio at 45 °C and 200 rpm. In synthesis 1, conversion was 62.5 ± 3.9% in 30 min at 10% m v-1 and 56.9 ± 2.8% in 54 min at 5% m v-1; while in synthesis 2, conversion was 79.0 ± 3.9% in 24 min at 10% m v-1, and 46.0 ± 2.4% in 54 min at 5% m v-1. Reuse tests after six consecutive cycles of reaction showed that the biocatalyst retained approximately 50% of its original activity for both reaction systems. CONCLUSIONS: CRL-AMP showed a high potential in the production of wax esters, since it started from low enzymatic load and high specific activities and conversions were obtained, in addition to allowing an increase in stability and recyclability of the prepared biocatalyst.


Asunto(s)
Ésteres , Lipasa , Biocatálisis , Candida/metabolismo , Emolientes , Estabilidad de Enzimas , Enzimas Inmovilizadas/metabolismo , Esterificación , Lipasa/metabolismo , Saccharomycetales
9.
Cleft Palate Craniofac J ; 59(8): 1056-1063, 2022 08.
Artículo en Inglés | MEDLINE | ID: mdl-34259068

RESUMEN

OBJECTIVE: To examine oral colonization and virulence factors of Candida spp. in patients aged from 0 to 18 months with cleft palate (CP). MATERIALS AND METHODS: Sixty babies were allocated into 3 groups: CP, CP with orthodontic plate (CPwP), and control group (Ctrl) without CP. Information on feeding habits, hygiene, and history of candidosis was collected. The presence of Candida spp. was investigated in samples of saliva. Fungal hydrophobicity, protease, esterase, phospholipase, and hemolysin were evaluated in a semiquantitative manner. RESULTS: Positive oral isolations of Candida spp. were detected in CP (89.5%), CPwP (100%), and Ctrl (44%) groups. Candidosis was more reported in the cleft groups than in the Ctrl group (P ≤ .023). There was a higher prevalence of Candida albicans, followed by Candida krusei, Candida tropicalis, and Candida parapsilosis in all groups. There was no uniformity of expression of virulence factors, either among different species or among different groups. CONCLUSION: Candida spp. colonization occurred in all groups, being superior in CPwP group. Candidosis episodes were more reported in patients from CPwP than in other groups, although candidosis was also registered in other groups. Candida albicans was the predominant species and virulence factors did not exhibit any pattern for species or groups of patients.


Asunto(s)
Candida , Fisura del Paladar , Candida/metabolismo , Humanos , Lactante , Saliva/microbiología , Factores de Virulencia/metabolismo
10.
Arch Microbiol ; 203(5): 2219-2228, 2021 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-33630118

RESUMEN

Candida genus comprises several species that can be found in the oral cavity and the gastrointestinal and genitourinary tracts of healthy individuals. Under certain conditions, however, they behave as opportunistic pathogens that colonize these tissues, most frequently when the immune system is compromised by a disease or under certain medical treatments. To colonize the human host, these organisms require to express cell wall proteins (CWP) that allowed them to adhere and adapt to the reactive oxygen (ROS) and nitrogen (RNS) species produced in the macrophage during the respiratory burst. The aim of this study was to determine how four Candida species respond to the oxidative stress imposed by cumene hydroperoxide (CHP). To this purpose, C. albicans, C. glabrata, C. krusei and C. parapsilosis were exposed to this oxidant which is known to generate ROS in the membrane phospholipids. Accordingly, both mock and CHP-exposed cells were used to extract and analyze CWP and also to measure catalase activity and the levels of protein carbonylation. Results indicated that all four species express different CWP to neutralize ROS. Most relevant among these proteins were the glycolytic enzymes enolase and glyceraldehyde-3-phosphate dehydrogenase, known as moonlight proteins because in addition to participate in glycolysis they play an important role in the cell response to ROS. In addition, a thiol-specific antioxidant enzyme (Tsa) was also found to counteract ROS.


Asunto(s)
Derivados del Benceno/farmacología , Candida/clasificación , Candida/metabolismo , Oxidantes/farmacología , Estrés Oxidativo/efectos de los fármacos , Antioxidantes/metabolismo , Candida/enzimología , Pared Celular/metabolismo , Tracto Gastrointestinal/microbiología , Gliceraldehído-3-Fosfato Deshidrogenasas/metabolismo , Humanos , Macrófagos/inmunología , Boca/microbiología , Fosfopiruvato Hidratasa/metabolismo , Proteómica , Especies de Nitrógeno Reactivo/metabolismo , Especies Reactivas de Oxígeno/metabolismo , Sistema Urogenital/microbiología
11.
Acta Sci Pol Technol Aliment ; 20(1): 93-102, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-33449523

RESUMEN

BACKGROUND: Omega fatty acids are a family of polyunsaturated fats associated with several health benefits. Lipases are enzymes with potential application in several food processes such as flavor and aroma, surfactants and formulations for the dairy and bakery industries. In this study, single cell oil and lipase production by Candida viswanathii CCR8137 were evaluated simultaneously from renewable carbon sources under nitrogen limitation. METHODS: Enzyme and single cell oil were obtained in submerged cultivations supplemented with triolein, tributyrin, corn oil, sunflower oil, canola oil and olive oil. The effects of glucose on lipid accumulation, fatty acid profile, enzyme production and cell morphology were also evaluated. RESULTS: The highest lipid accumulation (44.5%, w/w) was obtained from triolein, whereas olive oil was the best inducer of lipase synthesis (26.8 U/mL). Nitrogen limiting cultivations were a key parameter for an organic source which showed higher lipid accumulation and enzyme production than the tested inorganic nitrogen source. Glucose was a poor inducer of lipase synthesis, though increased values of lipid accumulation were observed from this carbon source with a maximum of 63.1% (w/w). The fatty acid profile of lipids produced by C. viswanathii CCR8137 showed a high content of omega-9 fatty acid (C18:1 n-9). The addition of glucose to the culture media resulted in the synthesis of essential fatty acids: vaccenic, linolenic and eicosadienoic acids. CONCLUSIONS: Therefore, C. viswanathii CCR8137 strain can be considered as an oleaginous yeast able to accumulate high concentrations of intracellular lipids, which are potential additives for food industry applications as well as being able to simultaneously synthesize high yields of lipase.


Asunto(s)
Candida/metabolismo , Glucosa/farmacología , Lipasa/metabolismo , Aceites de Plantas/farmacología , Triglicéridos/farmacología , Trioleína/farmacología , Glucosa/metabolismo , Metabolismo de los Lípidos , Aceites de Plantas/metabolismo , Análisis de la Célula Individual , Triglicéridos/metabolismo , Trioleína/metabolismo
12.
Electron. j. biotechnol ; Electron. j. biotechnol;46: 14-21, jul. 2020. tab, graf, ilus
Artículo en Inglés | LILACS | ID: biblio-1223215

RESUMEN

BACKGROUND: Biosurfactants are biomolecules that have the potential to be applied in food formulations due to their low toxicity and ability to improve sensory parameters. Considering the ability of yeasts to produce biosurfactants with food-friendly properties, the aim of the present study was to apply a biosurfactant produced by Candida utilis in the formulation of cookies. RESULTS: The biosurfactant was obtained with a yield of 24.22 ± 0.23 g/L. The characterization analysis revealed that the structure of a metabolized fatty acid with high oleic acid content (68.63 ± 0.61%), and the thermogravimetric analysis demonstrated good stability at temperatures lower than 200°C, potential for food applications. The biosurfactant also exhibited satisfactory antioxidant activity at concentrations evaluated, without cytotoxic potential for cell strains, L929 and RAW 264.7, according to the (3-(4,5-dimethylthiazol-2- yl)-2,5-diphenyltetrazolium bromide (MTT) assay. The incorporation of the surfactant into the dough of a standard cookie formulation to replace animal fat was carried out, achieving a softer, spongier product without significantly altering the physical and physicochemical properties or energy value. CONCLUSION: The thermal stability and antioxidant activity of the biosurfactant produced by C. utilis were verified, besides the positive contribution in the texture analysis of the cookies. Therefore, this biomolecule presents itself as a potential ingredient in flour-based sweet food formulations.


Asunto(s)
Tensoactivos/metabolismo , Candida/metabolismo , Alimentos Formulados , Bizcochos , Temperatura , Levaduras , Industria de Alimentos , Aditivos Alimentarios , Antioxidantes
13.
Bioprocess Biosyst Eng ; 43(11): 2107-2115, 2020 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-32594315

RESUMEN

Lipase stability in organic solvent is crucial for its application in many biotechnological processes as biocatalyst. One way to improve lipase's activity and stability in unusual reaction medium is its immobilization on inert supports. Here, lipases from different sources and immobilized through weak chemical interactions on hydrophobic and ionic supports had their transesterification ability dramatically dependent on the support and also on the solvent that had been used. The ethanolysis of sardine oil was carried out at the presence of cyclohexane and tert-amyl alcohol, in which Duolite A568-Thermomyces lanuginosa lipase derivative achieved 49% of ethyl esters production after 24 h in cyclohexane. The selectivity of immobilized lipases was also studied and, after 3 h of synthesis, the reaction with Duolite A568-Thermomyces lanuginosa derivative in cyclohexane produced 24% ethyl ester of eicosapentaenoic acid and 1.2% ethyl ester of docosahexaenoic acid, displaying a selectivity index of 20 times the ethyl ester of eicosapentaenoic acid. Different derivatives of Candida antarctica lipases fraction B (CALB) and phospholipase Lecitase® Ultra (Lecitase) were also investigated. Along these lines, a combination between these factors may be applied to improve the activity and selectivity of immobilized lipases, decreasing the total cost of the process.


Asunto(s)
Alcoholes/química , Ésteres/química , Proteínas Fúngicas/química , Hexanos/química , Lipasa/química , Compuestos Orgánicos/química , Solventes/química , Adsorción , Animales , Biocatálisis , Candida/metabolismo , Catálisis , Colorimetría/métodos , Ciclohexanos/química , Enzimas Inmovilizadas/química , Esterificación , Etano/química , Etanol/química , Peces , Interacciones Hidrofóbicas e Hidrofílicas , Iones , Pentanoles
14.
Arch Microbiol ; 202(7): 1729-1739, 2020 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-32328754

RESUMEN

We isolated two Candida pseudointermedia strains from the Atlantic rain forest in Brazil, and analyzed cellobiose metabolization in their cells. After growth in cellobiose medium, both strains had high intracellular ß-glucosidase activity [~ 200 U (g cells)-1 for 200 mM cellobiose and ~ 100 U (g cells)-1 for 2 mM pNPßG] and negligible periplasmic cellobiase activity. During batch fermentation, the strain with the best performance consumed all the available cellobiose in the first 18 h of the assay, producing 2.7 g L-1 of ethanol. Kinetics of its cellobiase activity demonstrated a high-affinity hydrolytic system inside cells, with Km of 12.4 mM. Our data suggest that, unlike other fungal species that hydrolyze cellobiose extracellularly, both analyzed strains transport it to the cytoplasm, where it is then hydrolyzed by high-affinity intracellular ß-glucosidases. We believe this study increases the fund of knowledge regarding yeasts from Brazilian microbiomes.


Asunto(s)
Candida/enzimología , Celobiosa/metabolismo , Madera/metabolismo , Madera/microbiología , beta-Glucosidasa/metabolismo , Brasil , Candida/aislamiento & purificación , Candida/metabolismo , Metabolismo de los Hidratos de Carbono , Etanol/metabolismo , Fermentación , Hidrólisis , Cinética
15.
ACS Infect Dis ; 6(5): 1273-1282, 2020 05 08.
Artículo en Inglés | MEDLINE | ID: mdl-32239912

RESUMEN

The polyene amphotericin B (AMB) exerts a powerful and broad antifungal activity. AMB acts by (i) binding to ergosterol, leading to pore formation at the fungal plasma membrane with subsequent ion leakage, and (ii) inducing the intracellular accumulation of reactive oxygen species (ROS). Herein, we have deciphered the AMB resistance mechanisms in clinical isolates of Candida haemulonii complex (C. haemulonii, C. duobushaemulonii, C. haemulonii var. vulnera) in comparison to other clinically relevant non-albicans Candida species. Membrane gas chromatography-mass spectrometry analysis revealed that the vast majority of sterols were composed of ergosterol pathway intermediates, evidencing the absence of AMB target. Supporting this data, C. haemulonii species complex demonstrated poor membrane permeability after AMB treatment. Regarding the oxidative burst, AMB induced the formation of ROS in all species tested; however, this phenomenon was slightly seen in C. haemulonii complex isolates. Our results indicated that these isolates displayed altered respiratory status, as revealed by their poor growth in nonfermented carbon sources, low consumption of oxygen, and derisive mitochondrial membrane potential. The use of specific inhibitors of mitochondrial respiratory chain (complex I-IV) revealed no effects on the yeast growth, highlighting the metabolic shift to fermentative pathway in C. haemulonii strains. Also, C. haemulonii complex proved to be highly resistant to oxidative burst agents, which can be correlated with a high activity of antioxidant enzymes. Our data demonstrated primary evidence suggesting that ergosterol content, mitochondrial function, and fungal redox homeostasis are involved in AMB fungicidal effects and might explain the resistance presented in this multidrug-resistant, emergent, and opportunistic fungal complex.


Asunto(s)
Anfotericina B/farmacología , Antifúngicos/farmacología , Candida/efectos de los fármacos , Farmacorresistencia Fúngica , Candida/metabolismo , Humanos , Pruebas de Sensibilidad Microbiana
16.
Microbiol Res ; 230: 126330, 2020 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-31541842

RESUMEN

Glycoconjugates found on cell walls of Candida species are fundamental for their pathogenicity. Laborious techniques have been employed to investigate the sugar composition of these microorganisms. Herein, we prepared a nanotool, based on the fluorescence of quantum dots (QDs) combined with the specificity of Cramoll lectin, to evaluate glucose/mannose profiles on three Candida species. The QDs-Cramoll conjugates presented specificity and bright fluorescence emission. The lectin preserved its biological activity after the conjugation process mediated by adsorption interactions. The labeling of Candida species was analyzed by fluorescence microscopy and quantified by flow cytometry. Morphological analyses of yeasts labeled with QDs-Cramoll conjugates indicated that C. glabrata (2.7 µm) was smaller when compared to C. albicans (4.0 µm) and C. parapsilosis sensu stricto (3.8 µm). Also, C. parapsilosis population was heterogeneous, presenting rod-shaped blastoconidia. More than 90% of cells of the three species were labeled by conjugates. Inhibition and saturation assays indicated that C. parapsilosis had a higher content of exposed glucose/mannose than the other two species. Therefore, QDs-Cramoll conjugates demonstrated to be effective fluorescent nanoprobes for evaluation of glucose/mannose constitution on the cell walls of fungal species frequently involved in candidiasis.


Asunto(s)
Candida/química , Colorantes Fluorescentes/química , Glucosa/análisis , Lectinas/química , Manosa/análisis , Microscopía Fluorescente/métodos , Candida/crecimiento & desarrollo , Candida/aislamiento & purificación , Candida/metabolismo , Candidiasis/diagnóstico , Candidiasis/microbiología , Pared Celular/química , Pared Celular/metabolismo , Glucosa/metabolismo , Humanos , Manosa/metabolismo , Microscopía Fluorescente/instrumentación , Nanopartículas/química , Puntos Cuánticos/química
17.
Braz. arch. biol. technol ; Braz. arch. biol. technol;63: e20180568, 2020. tab, graf
Artículo en Inglés | LILACS | ID: biblio-1132273

RESUMEN

Abstract Sophorolipids are glycolipids that have natural antimicrobial properties and present great potential in the pharmaceutical field. The present study aimed to produce sophorolipids from Candida bombicola using a chicken fat-based medium and evaluate the antimicrobial activity against Gram-negative (Proteus mirabilis, Escherichia coli, Salmonella enterica subsp. enterica) and Gram-positive bacteria (Enterococcus faecium, Staphylococcus aureus and Streptococcus mutans). The production of sophorolipids reached 27.86 g L-1. Based on the structural characterization, 73.55% of the sophorolipids present a mixture of acidic monoacetylated C18:2 and lactonic diacetylated C16:0, and 26.45% were present in the diacetylated C18:1 lactonic form. Bacteria submitted to sophorolipid exposure showed a reduction in viability at doses of 500 μg mL-1 and 2,000 μg mL-1 against Gram-positive and Gram-negative bacteria, respectively. These results suggest that sophorolipids produced in chicken fat medium may be used as antimicrobial agents to prevent or eliminate contamination by different pathogens.


Asunto(s)
Candida/metabolismo , Glucolípidos/farmacología , Enterococcus faecium/efectos de los fármacos , Bacterias Gramnegativas/efectos de los fármacos , Antibacterianos/farmacología , Proteus mirabilis/efectos de los fármacos , Glucolípidos/aislamiento & purificación , Salmonella enterica/efectos de los fármacos , Escherichia coli/efectos de los fármacos , Antibacterianos/aislamiento & purificación
18.
Int J Mol Sci ; 20(22)2019 Nov 19.
Artículo en Inglés | MEDLINE | ID: mdl-31752306

RESUMEN

The synthesis of ethyl butyrate catalyzed by lipases A (CALA) or B (CALB) from Candida antarctica immobilized onto magnetic nanoparticles (MNP), CALA-MNP and CALB-MNP, respectively, is hereby reported. MNPs were prepared by co-precipitation, functionalized with 3-aminopropyltriethoxysilane, activated with glutaraldehyde, and then used as support to immobilize either CALA or CALB (immobilization yield: 100 ± 1.2% and 57.6 ± 3.8%; biocatalysts activities: 198.3 ± 2.7 Up-NPB/g and 52.9 ± 1.7 Up-NPB/g for CALA-MNP and CALB-MNP, respectively). X-ray diffraction and Raman spectroscopy analysis indicated the production of a magnetic nanomaterial with a diameter of 13.0 nm, whereas Fourier-transform infrared spectroscopy indicated functionalization, activation and enzyme immobilization. To determine the optimum conditions for the synthesis, a four-variable Central Composite Design (CCD) (biocatalyst content, molar ratio, temperature and time) was performed. Under optimized conditions (1:1, 45 °C and 6 h), it was possible to achieve 99.2 ± 0.3% of conversion for CALA-MNP (10 mg) and 97.5 ± 0.8% for CALB-MNP (12.5 mg), which retained approximately 80% of their activity after 10 consecutive cycles of esterification. Under ultrasonic irradiation, similar conversions were achieved but at 4 h of incubation, demonstrating the efficiency of ultrasound technology in the enzymatic synthesis of esters.


Asunto(s)
Butiratos/metabolismo , Candida/metabolismo , Enzimas Inmovilizadas/química , Enzimas Inmovilizadas/metabolismo , Proteínas Fúngicas/metabolismo , Lipasa/metabolismo , Nanopartículas de Magnetita/química , Biocatálisis , Esterificación/fisiología , Glutaral/metabolismo , Ondas Ultrasónicas
19.
Protein Sci ; 28(11): 2024-2029, 2019 11.
Artículo en Inglés | MEDLINE | ID: mdl-31503375

RESUMEN

The LUFS domain (LUG/LUH, Flo8, single-strand DNA-binding protein [SSBP]) is a well-conserved and apparently ancient region found in diverse proteins and taxa. This domain, which has as its most obvious structural feature a series of three helices, has been identified in transcriptional regulator proteins of animals, plants, and fungi. Recently, in these pages (Wang et al., Protein Sci., 2019, 28:788-793), the first crystal structure of a LUFS domain was reported, for the human SSBP2, a transcriptional repressor. We briefly address how the new insights into LUFS structures might contribute to a better understanding of an important transcriptional activator of yeasts that contains the LUFS domain, Flo8, and consider how a focus on the LUFS domain and its variation could help us to understand etiologies of drug resistance in a recently emerged pathogenic fungus, Candida auris.


Asunto(s)
Anfotericina B/farmacología , Antifúngicos/farmacología , Candida/efectos de los fármacos , Proteínas de Unión al ADN/antagonistas & inhibidores , Farmacorresistencia Fúngica/efectos de los fármacos , Secuencia de Aminoácidos , Anfotericina B/química , Antifúngicos/química , Candida/metabolismo , Proteínas de Unión al ADN/química , Proteínas de Unión al ADN/metabolismo , Pruebas de Sensibilidad Microbiana , Modelos Moleculares , Alineación de Secuencia
20.
Braz J Microbiol ; 50(2): 379-388, 2019 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-30826999

RESUMEN

The Asparagaceae family is endemic from America, being the Agave genus the most important. The Agave species possess economic relevance and are use as raw material to produce several distilled alcoholic beverages, as bacanora, tequila, and mezcal. The fermentation process has been carry out either spontaneously or by adding a selected yeast strain. The latter is generally responsible for the production of ethanol and volatile compounds. This study comprised five Agave species (A. angustifolia, A. cupreata, A. durangensis, A. salmiana, and A. tequilana) and eight endogenous yeast strains: five of them were non-Saccharomyces (Torulaspora delbrueckii, Zygosaccharomyces bisporus, Candida ethanolica, and two Kluyveromyces marxianus) and three Saccharomyces cerevisiae strains. The results showed that the S. cerevisiae strains were not able to grow on A. durangensis and A. salmiana juices. The Kluyveromyces marxianus strains grew and fermented all the agave juices and displayed high ethanol production (48-52 g L-1) and volatile compounds. The ethanol production was higher on A. angustifolia juice (1.1-2.8-fold), whereas the volatile compound was dependent on both yeast strain and the Agave species. The use of endogenous non-Saccharomyces yeast strains is feasible, as they may outperform S. cerevisiae regarding the production of fermented beverages from agave plants with a high content of ethanol and aromatic compounds. Graphical abstract.


Asunto(s)
Agave/microbiología , Bebidas Alcohólicas/microbiología , Candida/metabolismo , Kluyveromyces/metabolismo , Saccharomyces cerevisiae/metabolismo , Torulaspora/metabolismo , Zygosaccharomyces/metabolismo , Candida/crecimiento & desarrollo , Etanol/metabolismo , Fermentación/fisiología , Kluyveromyces/crecimiento & desarrollo , Saccharomyces cerevisiae/crecimiento & desarrollo , Torulaspora/crecimiento & desarrollo , Zygosaccharomyces/crecimiento & desarrollo
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