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1.
Biomolecules ; 14(6)2024 May 27.
Artículo en Inglés | MEDLINE | ID: mdl-38927033

RESUMEN

It is known that selenium (Se) is an essential trace element, important for the growth and other biological functions of fish. One of its most important functions is to contribute to the preservation of certain biological components, such as DNA, proteins, and lipids, providing protection against free radicals resulting from normal metabolism. The objective of this study was to evaluate and optimize selenium accumulation in the native yeast Rhodotorula mucilaginosa 6S. Sodium selenite was evaluated at different concentrations (5-10-15-20-30-40 mg/L). Similarly, the effects of different concentrations of nitrogen sources and pH on cell growth and selenium accumulation in the yeast were analyzed. Subsequently, the best cultivation conditions were scaled up to a 2 L reactor with constant aeration, and the proteome of the yeast cultured with and without sodium selenite was evaluated. The optimal conditions for biomass generation and selenium accumulation were found with ammonium chloride and pH 5.5. Incorporating sodium selenite (30 mg/L) during the exponential phase in the bioreactor after 72 h of cultivation resulted in 10 g/L of biomass, with 0.25 mg total Se/g biomass, composed of 25% proteins, 15% lipids, and 0.850 mg total carotenoids/g biomass. The analysis of the proteomes associated with yeast cultivation with and without selenium revealed a total of 1871 proteins. The results obtained showed that the dynamic changes in the proteome, in response to selenium in the experimental medium, are directly related to catalytic activity and oxidoreductase activity in the yeast. R. mucilaginosa 6S could be an alternative for the generation of selenium-rich biomass with a composition of other nutritional compounds also of interest in aquaculture, such as proteins, lipids, and pigments.


Asunto(s)
Proteómica , Rhodotorula , Selenio , Rhodotorula/metabolismo , Rhodotorula/crecimiento & desarrollo , Rhodotorula/efectos de los fármacos , Selenio/metabolismo , Selenio/farmacología , Proteómica/métodos , Biomasa , Reactores Biológicos/microbiología , Selenito de Sodio/metabolismo , Selenito de Sodio/farmacología , Concentración de Iones de Hidrógeno , Proteoma/metabolismo , Proteínas Fúngicas/metabolismo
2.
Molecules ; 26(8)2021 Apr 18.
Artículo en Inglés | MEDLINE | ID: mdl-33919590

RESUMEN

Seaweed processing generates liquid fraction residual that could be used as a low-cost nutrient source for microbial production of metabolites. The Rhodotorula strain is able to produce antimicrobial compounds known as sophorolipids. Our aim was to evaluate sophorolipid production, with antibacterial activity, by marine Rhodotorula rubra using liquid fraction residual (LFR) from the brown seaweed Macrocystis pyrifera as the nutrient source. LFR having a composition of 32% w/w carbohydrate, 1% w/w lipids, 15% w/w protein and 52% w/w ash. The best culture condition for sophorolipid production was LFR 40% v/v, without yeast extract, artificial seawater 80% v/v at 15 °C by 3 growth days, with the antibacterial activity of 24.4 ± 3.1 % on Escherichia coli and 21.1 ± 3.8 % on Staphylococcus aureus. It was possible to identify mono-acetylated acidic and methyl ester acidic sophorolipid. These compounds possess potential as pathogen controllers for application in the food industry.


Asunto(s)
Macrocystis/química , Ácidos Oléicos/química , Extractos Vegetales/farmacología , Rhodotorula/efectos de los fármacos , Organismos Acuáticos/química , Ácidos Oléicos/farmacología , Extractos Vegetales/química , Rhodotorula/patogenicidad
3.
Rev Iberoam Micol ; 37(2): 47-52, 2020.
Artículo en Español | MEDLINE | ID: mdl-32709501

RESUMEN

BACKGROUND: Candida albicans and Rhodotorula mucilaginosa are yeasts of clinical importance in the oral cavity. In immunocompromised patients they can cause some pathologies that must be controlled with antimicrobials. AIMS: To evaluate and compare the antimicrobial efficacy of commercially available mouthrinses against strains of C. albicans and R. mucilaginosa. METHODS: The six mouthwashes studied in vitro were formulated (alone or in combination) with chlorhexidine (CHX) 0.12%, CHX 0.1%, CHX 0.05%, cetylpyridinium chloride (CPC) 0.075%, CPC 0.05%, and essential oils. Ten C. albicans and R. mucilaginosa isolates each were studied. The agar diffusion method (Mueller Hinton II), with incubation at 32°C was used to evaluate the antifungal activity. RESULTS: The results of this study indicate that mouthwashes with CHX 0.1%, CHX 0.12%, CHX 0.05% + CPC 0.05%, CHX 0.12% + CPC 0.05% and CPC 0.075% have an antifungal effect against C. albicans and R. mucilaginosa. CHX 0.1% led to the broadest inhibition zone for C. albicans and R. mucilaginosa (25.65±2.39mm and 40.05±3.31mm). Essential oils did not show any antifungal activity. Statistical analysis showed no statistical difference between mouth rinses CHX 0.1%, CHX 0.12% and CHX 0.12% + CPC 0.05% (p=0.0001) against C. albicans and R. mucilaginosa. CONCLUSIONS: Mouthwashes with CHX showed higher antifungal activity against C. albicans and R. mucilaginosa than other mouthwashes studied.


Asunto(s)
Antifúngicos/farmacología , Candida albicans/efectos de los fármacos , Antisépticos Bucales/farmacología , Rhodotorula/efectos de los fármacos , Cetilpiridinio/farmacología , Clorhexidina/farmacología , Pruebas Antimicrobianas de Difusión por Disco , Evaluación Preclínica de Medicamentos , Humanos , Aceites Volátiles/farmacología
4.
Braz J Microbiol ; 51(1): 95-98, 2020 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-31776863

RESUMEN

Infections caused by Rhodotorula spp. are increasing worldwide. This study identified, through the light of the new taxonomic advances on the subphylum Pucciniomycotina, 16 isolates from blood cultures and compared their antifungal susceptibility on microdilution and gradient diffusion methods. Internal transcriber spacer sequencing identified Rhodotorula mucilaginosa (n = 12), Rhodotorula toruloides (n = 2), Rhodotorula dairenensis (n = 1), and Cystobasidium minutum (n = 1). Amphotericin B was the most effective drug. A good essential agreement was observed on MIC values of amphotericin B and voriconazole determined by the two methods. Therefore, the gradient method is useful for susceptibility tests of R. mucilaginosa against these drugs.


Asunto(s)
Antifúngicos/farmacología , Pruebas de Sensibilidad Microbiana/métodos , Micosis/microbiología , Rhodotorula/clasificación , Rhodotorula/efectos de los fármacos , Anfotericina B/farmacología , Cultivo de Sangre , Brasil , ADN Intergénico/genética , Difusión , Humanos , Micosis/sangre , Rhodotorula/genética , Voriconazol/farmacología
5.
Molecules ; 24(15)2019 Aug 01.
Artículo en Inglés | MEDLINE | ID: mdl-31374810

RESUMEN

Capsaicin is a chemical compound found in pungent chili peppers (Capsicum spp.). In biotechnology, capsaicin has been proposed as a pathogen control; however, its low solubility in water and high instability limits its uses. The aim of this work was to study the effect of high concentrations of capsaicin on the synthesis of nanoparticles and to evaluate their inhibitory effect on the growth of Rhodotorula mucilaginosa yeast. Bovine serum albumin (BSA)-capsaicin nanoparticles were formulated at 0, 16.2, 32.5, 48.7 and 65.0 µg of capsaicin per mg of BSA. Nanoparticle properties were evaluated and they were added to cultures of R. mucilaginosa to quantify their effect on cell viability. We found that increased capsaicin levels caused several changes to the physicochemical parameters, probably due to changes in the hydrophobicity sites of the albumin during the nanostructuration. The administration of nanoparticles to cultures of R. mucilaginosa produced a maximal viability with nanoparticles at 16.2 µg/mg; on the contrary, nanoparticles at 65.0 µg/mg caused maximal cell death. R. mucilaginosa cells displayed a hormesis effect in response to the nanoparticle dose concentration. The nanoparticles showed different responses during the uptake process, probably as a consequence of the nanostructural properties of capsaicin in the BSA molecules.


Asunto(s)
Capsaicina/química , Nanopartículas/química , Rhodotorula/efectos de los fármacos , Capsaicina/farmacología , Línea Celular , Supervivencia Celular/efectos de los fármacos , Hormesis , Humanos , Rhodotorula/patogenicidad , Albúmina Sérica Bovina/química
6.
Mycopathologia ; 184(1): 35-43, 2019 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-30632048

RESUMEN

Rhodotorula species are emerging as opportunistic pathogens, causing catheter-associated fungemia in patients with compromised immunity. R. mucilaginosa is considered the most common species involved in human infections. Correct identification and susceptibility testing of Rhodotorula isolates recovered from the blood stream or central nervous system are essential to determine the best management of this unusual infection. The antifungal susceptibility tests showed that Rhodotorula was susceptible to low concentrations of amphotericin B (AMB) but was less susceptible to voriconazole. Combinations of AMB plus several non-antifungal medications were evaluated against 35 susceptible (Rm AMB-S) and resistant (Rm AMB-R) clinical Rhodotorula isolates using the broth microdilution checkerboard technique. We showed that in vitro exposure to increasing concentrations of AMB changed the susceptibility profile to these strains, which were named the Rm AMB-R group. The most synergistic interactions were AMB + simvastatin, followed by AMB + amlodipine and AMB + warfarin. Synergism and antagonism were observed in both groups for the combination AMB + cyclosporine A. AMB combined with a fluoroquinolone (AMB + levofloxacin) also demonstrated antagonism for the Rm AMB-S strains, but a high percentage of synergistic interactions was observed for the Rm AMB-R group. A combination drug approach can provide a different strategy to treat infections caused by AMB-resistant R. mucilaginosa.


Asunto(s)
Anfotericina B/farmacología , Antifúngicos/farmacología , Sinergismo Farmacológico , Inhibidores Enzimáticos/farmacología , Rhodotorula/efectos de los fármacos , Humanos , Pruebas de Sensibilidad Microbiana
7.
Sci Rep ; 8(1): 798, 2018 01 15.
Artículo en Inglés | MEDLINE | ID: mdl-29335484

RESUMEN

Bacterial species are able to colonize and establish communities in biotic and abiotic surfaces. Moreover, within the past five decades, incidence of bacterial strains resistant to currently used antibiotics has increased dramatically. This has led to diverse health issues and economical losses for different industries. Therefore, there is a latent need to develop new and more efficient antimicrobials. This work reports an increased production of an exopolysaccharide in a native yeast strain isolated from the Mexican Northeast, Rhodotorula mucilaginosa UANL-001L, when co-cultured with E. coli. The exopolysaccharide produced is chemically and physically characterized and its applications as an antimicrobial and antibiofilm are explored. The exopolysaccharide is capable of inhibiting planktonic growth and biofilm formation in Escherichia coli, Pseudomonas aeruginosa and Staphylococcus aureus. Additionally, the exopolysaccharide studied here does not exhibit cytotoxic effects when assessed both, in vitro against an H9c2 mammalian cell line, and in vivo in a murine toxicity model. Taken together, the properties of this exopolysaccharide indicate that it has potential applications to inhibit bacterial colonization in medical and industrial settlings.


Asunto(s)
Antiinfecciosos/farmacología , Escherichia coli/crecimiento & desarrollo , Polisacáridos/biosíntesis , Rhodotorula/crecimiento & desarrollo , Animales , Apoptosis/efectos de los fármacos , Biopelículas/efectos de los fármacos , Línea Celular , Escherichia coli/efectos de los fármacos , Escherichia coli/metabolismo , Cinética , Microscopía Electrónica de Rastreo , Polisacáridos/química , Polisacáridos/farmacología , Pseudomonas aeruginosa/fisiología , Ratas , Rhodotorula/efectos de los fármacos , Rhodotorula/metabolismo , Espectroscopía Infrarroja por Transformada de Fourier , Staphylococcus aureus/fisiología
8.
Braz J Microbiol ; 46(1): 117-23, 2015 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-26221096

RESUMEN

In this study, we isolated and phenotypically identified 108 yeast strains from various clinical specimens collected from 100 hospitalized patients at three tertiary hospitals in São Luís-Maranhão, Brazil, from July to December 2010. The isolates were analyzed for their susceptibility to four of the most widely used antifungal agents in the surveyed hospitals, amphotericin B, fluconazole, 5-flucytosine and voriconazole. The species identified were Candida albicans (41.4%), Candida tropicalis (30.1%), C. glabrata (7.4%), Candida parapsilosis (5.5%), Candida krusei (4.6%), Cryptococcus neoformans (4.6%), Trichosporon spp . (3.7%), Candida norvegensis (0.9%), Rhodotorula glutinis (0.9%) and Pichia farinosa (0.9%). A higher isolation rate was observed in the following clinical specimens: urine (54 isolates; 50%), respiratory tract samples (21 isolates; 19.4%) and blood (20 isolates; 18.6%). Candida albicans isolates were 100% sensitive to all antifungal agents tested, whereas Candida krusei and Crytococcus neoformans displayed intermediate resistance to 5-flucytosine, with Minimal Inhibitory Concentration (MIC) values of 8 mg/mL and 16 mg/mL, respectively. Both strains were also S-DD to fluconazole with an MIC of 16 mg/mL. C. tropicalis was resistant to 5-flucytosine with an MIC of 32 µg/mL. This study demonstrates the importance of identifying the yeast species involved in community and nosocomial infections.


Asunto(s)
Candida/aislamiento & purificación , Micosis/microbiología , Pichia/aislamiento & purificación , Rhodotorula/aislamiento & purificación , Trichosporon/aislamiento & purificación , Anciano , Anciano de 80 o más Años , Antifúngicos/farmacología , Brasil , Candida/efectos de los fármacos , Femenino , Humanos , Masculino , Pruebas de Sensibilidad Microbiana , Persona de Mediana Edad , Micosis/epidemiología , Pichia/efectos de los fármacos , Prevalencia , Rhodotorula/efectos de los fármacos , Centros de Atención Terciaria , Trichosporon/efectos de los fármacos
9.
Braz. j. microbiol ; Braz. j. microbiol;46(1): 117-123, 05/2015. tab
Artículo en Inglés | LILACS | ID: lil-748245

RESUMEN

In this study, we isolated and phenotypically identified 108 yeast strains from various clinical specimens collected from 100 hospitalized patients at three tertiary hospitals in São Luís-Maranhão, Brazil, from July to December 2010. The isolates were analyzed for their susceptibility to four of the most widely used antifungal agents in the surveyed hospitals, amphotericin B, fluconazole, 5-flucytosine and voriconazole. The species identified were Candida albicans (41.4%), Candida tropicalis (30.1%), C. glabrata (7.4%), Candida parapsilosis (5.5%), Candida krusei (4.6%), Cryptococcus neoformans (4.6%), Trichosporon spp. (3.7%), Candida norvegensis (0.9%), Rhodotorula glutinis (0.9%) and Pichia farinosa (0.9%). A higher isolation rate was observed in the following clinical specimens: urine (54 isolates; 50%), respiratory tract samples (21 isolates; 19.4%) and blood (20 isolates; 18.6%). Candida albicans isolates were 100% sensitive to all antifungal agents tested, whereas Candida krusei and Crytococcus neoformans displayed intermediate resistance to 5-flucytosine, with Minimal Inhibitory Concentration (MIC) values of 8 mg/mL and 16 mg/mL, respectively. Both strains were also S-DD to fluconazole with an MIC of 16 mg/mL. C. tropicalis was resistant to 5-flucytosine with an MIC of 32 μg/mL. This study demonstrates the importance of identifying the yeast species involved in community and nosocomial infections.


Asunto(s)
Anciano , Anciano de 80 o más Años , Femenino , Humanos , Masculino , Persona de Mediana Edad , Candida/aislamiento & purificación , Micosis/microbiología , Pichia/aislamiento & purificación , Rhodotorula/aislamiento & purificación , Trichosporon/aislamiento & purificación , Antifúngicos/farmacología , Brasil , Candida/efectos de los fármacos , Pruebas de Sensibilidad Microbiana , Micosis/epidemiología , Prevalencia , Pichia/efectos de los fármacos , Rhodotorula/efectos de los fármacos , Centros de Atención Terciaria , Trichosporon/efectos de los fármacos
10.
Antimicrob Agents Chemother ; 57(1): 382-9, 2013 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-23114761

RESUMEN

Rhodotorula species are emergent fungal pathogens capable of causing invasive infections, primarily fungemia. They are particularly problematic in immunosuppressed patients when using a central venous catheter. In this study, we evaluated the species distribution of 51 clinical and 8 environmental Rhodotorula species isolates using the ID32C system and internal transcribed spacer (ITS) sequencing. Antifungal susceptibility testing and biofilm formation capability using a crystal violet staining assay were performed. Using ITS sequencing as the gold standard, the clinical isolates were identified as follows: 44 R. mucilaginosa isolates, 2 R. glutinis isolates, 2 R. minuta isolates, 2 R. dairenensis isolates, and 1 Rhodosporidium fluviale isolate. The environmental isolates included 7 R. mucilaginosa isolates and 1 R. slooffiae isolate. Using the ID32C system, along with a nitrate assimilation test, only 90.3% of the isolates tested were correctly identified. In the biofilm formation assay, R. mucilaginosa and R. minuta exhibited greater biofilm formation ability compared to the other Rhodotorula species; the clinical isolates of R. mucilaginosa showed greater biofilm formation compared to the environmental isolates (P = 0.04). Amphotericin B showed good in vitro activity (MIC ≤ 1 µg/ml) against planktonic cells, whereas voriconazole and posaconazole showed poor activity (MIC(50)/MIC(90), 2/4 µg/ml). Caspofungin and fluconazole MICs were consistently high for all isolates tested (≥64 µg/ml and ≥ 4 µg/ml, respectively). In this study, we emphasized the importance of molecular methods to correctly identify Rhodotorula species isolates and non-R. mucilaginosa species in particular. The antifungal susceptibility profile reinforces amphotericin B as the antifungal drug of choice for the treatment of Rhodotorula infections. To our knowledge, this is the first study evaluating putative differences in the ability of biofilm formation among different Rhodotorula species.


Asunto(s)
Anfotericina B/farmacología , Antifúngicos/farmacología , ADN Espaciador Ribosómico/genética , Fungemia/microbiología , Rhodotorula/efectos de los fármacos , Rhodotorula/genética , Microbiología del Suelo , Biopelículas/efectos de los fármacos , Biopelículas/crecimiento & desarrollo , ADN Espaciador Ribosómico/clasificación , Fungemia/tratamiento farmacológico , Violeta de Genciana , Humanos , Pruebas de Sensibilidad Microbiana , Viabilidad Microbiana/efectos de los fármacos , Microscopía Electrónica de Rastreo , Filogenia , Plancton/efectos de los fármacos , Plancton/crecimiento & desarrollo , Rhodotorula/clasificación , Rhodotorula/aislamiento & purificación , Análisis de Secuencia de ADN , Especificidad de la Especie
11.
Biometals ; 25(3): 517-27, 2012 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-22391792

RESUMEN

In order to understand the mechanism involved in Rhodotorula mucilaginosa RCL-11 resistance to copper a proteomic study was conducted. Atomic absorption spectroscopy showed that the copper concentration in the medium decreased from 0.5 to 0.19 mM 48 h after inoculation of the yeast. Analysis of one-dimensional gel electrophoresis of crude cell extracts revealed expression of differential bands between cells with and without copper. In order to study this difference, two-dimensional electrophoresis of R. mucilaginosa RCL-11 exposed to Cu for 16, 24, and 48 h was carried out. Identification of differentially expressed proteins was performed by MALDI-TOF/TOF. Ten of the 16 spots identified belonged to heat shock proteins. Superoxide dismutase, methionine synthase and beta-glucosidase were also found over-expressed at high copper concentrations. The results obtained in the present work show that when R. mucilaginosa RCL-11 is exposed to 0.5 mM copper, differential proteins, involved in cell resistance mechanisms, are expressed.


Asunto(s)
Cobre/farmacología , Proteómica/métodos , Rhodotorula/metabolismo , 5-Metiltetrahidrofolato-Homocisteína S-Metiltransferasa/metabolismo , Biodegradación Ambiental , Electroforesis en Gel Bidimensional , Rhodotorula/efectos de los fármacos , Superóxido Dismutasa/metabolismo , beta-Glucosidasa/metabolismo
12.
Rev Iberoam Micol ; 28(1): 32-5, 2011.
Artículo en Español | MEDLINE | ID: mdl-21147249

RESUMEN

BACKGROUND: Yeasts represent the second cause of nail fungal infection in the world, and Candida albicans and Candida parapsilosis are the two most common species. OBJECTIVES: To determine the yeast species frequency and their in vitro antifungal susceptibility, obtained from patients with clinical features suggestive of onychomycosis. METHODS: A prospective study was carried out in four dermatological care centers in Mexico from 2004 to 2007. Clinical diagnosis was corroborated by direct examination and culture. The yeast species was determined by morphological and biochemical tests. An antifungal susceptibility test to ketoconazole, itraconazole and fluconazole by the broth microdilution method was performed on each isolate (document M27-A2). RESULTS: One hundred sixty-six yeast isolates were obtained; the most frequently found species were C. parapsilosis (31.9%), C. albicans (22.4%) and Candida guilliermondii (12.7%). Of all isolates, 51 showed resistance to one or several of the azole compounds: 33 to itraconazole, 12 to ketoconazole and 6 to fluconazole. It was remarkable that the four Candida glabrata isolates were resistant to the three azole compounds; C. guilliermondii and Candida famata were resistant to itraconazole in 42.9% and 54.5%, respectively. CONCLUSION: The results obtained show the importance of identifying the aetiological agent and antifungal susceptibility testing in order to avoid therapeutic failures in onychomycosis.


Asunto(s)
Antifúngicos/farmacología , Onicomicosis/microbiología , Levaduras/aislamiento & purificación , Adulto , Candida/efectos de los fármacos , Candida/aislamiento & purificación , Candidiasis Cutánea/epidemiología , Candidiasis Cutánea/microbiología , Farmacorresistencia Fúngica , Fluconazol/farmacología , Humanos , Itraconazol/farmacología , Cetoconazol/farmacología , México/epidemiología , Onicomicosis/epidemiología , Pichia/efectos de los fármacos , Pichia/aislamiento & purificación , Estudios Prospectivos , Rhodotorula/efectos de los fármacos , Rhodotorula/aislamiento & purificación , Especificidad de la Especie , Trichosporon/efectos de los fármacos , Trichosporon/aislamiento & purificación , Levaduras/efectos de los fármacos
13.
Lett Appl Microbiol ; 51(4): 370-6, 2010 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-20723041

RESUMEN

AIMS: This study was undertaken to detect, identify and determine antifungal susceptibility of yeast strains isolated from dental solid waste and to evaluate airborne fungi in the Brazilian dental health care environment and in the waste storage room. METHODS AND RESULTS: A group of 17 yeast strains were identified by macroscopic and microscopic characteristics, API 20C Aux system and Multiplex PCR. All 104 airborne fungal colonies were identified by macroscopic and microscopic morphology. The CLSI broth microdilution method was utilized as the susceptibility test. Candida parapsilosis was the prevailing yeast species recovered from waste, followed by Rhodotorula glutinis. Three strains of Candida guilliermondii presented minimal inhibitory concentration values considered to be susceptible dose dependent (2 µg ml(-1)) to voriconazole. Of all airborne fungal species, 69% were recovered from the waste storage room and 31% were recovered from the clinical/surgical environment. Most of them were identified as Cladosporium spp. CONCLUSIONS: These findings reinforce the potential risk of waste handling and point out the need for safe management to minimize the spread of these agents to the environment. Filamentous fungi isolation in almost all sampled environments indicates that a periodic monitoring of airborne microbiota in the dental health care service environment is required. SIGNIFICANCE AND IMPACT OF THE STUDY: The survival of yeast strains for 48 h suggests that dental waste should be carefully controlled and monitored.


Asunto(s)
Microbiología del Aire , Servicios de Salud Dental , Residuos Dentales/análisis , Hongos/aislamiento & purificación , Antifúngicos/farmacología , Brasil , Candida/clasificación , Candida/efectos de los fármacos , Candida/aislamiento & purificación , Hongos/clasificación , Hongos/efectos de los fármacos , Hongos/genética , Humanos , Pruebas de Sensibilidad Microbiana , Reacción en Cadena de la Polimerasa/métodos , Rhodotorula/clasificación , Rhodotorula/efectos de los fármacos , Rhodotorula/aislamiento & purificación , Especificidad de la Especie
14.
Photochem Photobiol Sci ; 9(8): 1145-51, 2010 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-20571712

RESUMEN

In this paper we report the relationship between carotenoids and ergosterol and cell UV-B resistance in different strains of the yeast Rhodotorula mucilaginosa. Cell survival was studied using a set of 13 strains; additionally, two mutants (a hyper-producing one and a colourless one) in combination with diphenylamine (DPA), a carotenogenesis inhibitor, were used. A positive correlation between total carotenoids and survival to UV-B radiation was found. However, when individual carotenoid concentrations were tested, only torularhodin was found to be significantly related to UV-B survival. On the contrary, ergosterol did not affect survival. The hyper-pigmented strain showed an enhanced survival (up to 250%) compared to the parental strain, while the survival of the albino mutant was similar to that experienced by the parental strain; however, observed changes in survival were dose dependent. The cyclobutane pyrimidine dimers (CPDs), one of the major forms of DNA damage caused by UV exposure, appears as unrelated to the accumulation of carotenoids and cell survival. These results indicate that bearing higher torularhodin concentrations enhances UV-B survival in yeasts and, thus, the accumulation of this pigment constitutes an important mechanism that improves the resistance of yeasts to UV-B.


Asunto(s)
Carotenoides/fisiología , Rhodotorula/efectos de la radiación , Carotenoides/farmacología , Supervivencia Celular , Daño del ADN , Difenilamina/farmacología , Ergosterol/farmacología , Dímeros de Pirimidina/química , Rhodotorula/efectos de los fármacos , Rayos Ultravioleta
15.
Water Sci Technol ; 60(5): 1225-32, 2009.
Artículo en Inglés | MEDLINE | ID: mdl-19717909

RESUMEN

The present study explored the ability of the yeast Rhodotorula mucilaginosa RCL-11 to adapt to increasing Cu(II) concentrations, measuring oxidative stress through superoxide dismutase and catalase activity in two parallel sequential batch assays. One assay was performed in Erlenmeyer flasks without aeration and a second in a fermentor in which the dissolved oxygen was maintained at 30% saturation. Both assays were carried out by increasing Cu(II) concentrations in five sequential steps: 0; 0.1; 0.2; 0.5 and 1 mM. Each assay was incubated at 30 degrees C, 250 rpm and pH 5.5. While growth parameters of R. mucilaginosa RCL-11 decreased 90-95% with increasing Cu(II) concentration in the culture medium, the oxidative stress level increased from 30 to 55% in both assays. Cells grown under controlled oxygen conditions showed 30% more copper bioaccumulation and 10% glucose consumption when compared with cells grown without aeration. SOD activity was higher under controlled than without aeration, whereas CAT activity was similar under both test conditions. Cu(II) bioaccumulation by R. mucilaginosa RCL-11 and a possible increase in this capacity by adaptation of the strain under controlled aeration represent a potential valuable tool for treatment of effluents or water bioremediation with high copper contents.


Asunto(s)
Reactores Biológicos , Cobre/aislamiento & purificación , Cobre/metabolismo , Contaminantes Ambientales/aislamiento & purificación , Contaminantes Ambientales/metabolismo , Rhodotorula/crecimiento & desarrollo , Rhodotorula/metabolismo , Biodegradación Ambiental , Catalasa/metabolismo , Cobre/toxicidad , Contaminantes Ambientales/toxicidad , Fermentación , Estrés Oxidativo/efectos de los fármacos , Rhodotorula/efectos de los fármacos , Rhodotorula/enzimología , Superóxido Dismutasa/metabolismo
16.
J Basic Microbiol ; 49(4): 395-403, 2009 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-19322830

RESUMEN

The effect of high Cu(II) concentrations on superoxide dismutase (SOD) and catalase (CAT) activity in Candida fukuyamaensis RCL-3 and Rhodotorula mucilaginosa RCL-11, previously isolated from a copper filter at a mine plant in Argentina, was studied. Addition of 0.1, 0.2 and 0.5 mM Cu(II) to the culture medium increased total SOD and CAT activity in both strains. Native polyacrylamide gel electrophoresis revealed two bands with SOD activity for C. fukuyamaensis RCL-3 and only one for R. mucilaginosa RCL-11; the three bands corresponded to MnSOD.Intracellular accumulation of copper and morphological changes was observed using electron microscopy. Dark bodies examined with transmission electron microscopy (TEM) after 48 h of incubation probably corresponded to copper deposits. The number of dark bodies in R. mucilaginosa RCL-11 grew with increasing incubation time, whereas in C. fukuyamaensis RCL-3 the amount decreased. Scanning electron micrographs (SEM) of C. fukuyamaensis RCL-3 did not reveal any differences compared with the control, but R. mucilaginosa RCL-11 cells were bigger than control ones. TEM confirmed absence of compartmentalization mechanisms in Cu(II) detoxification since electron-dense bodies were mainly found in the cytoplasm.


Asunto(s)
Candida/efectos de los fármacos , Cobre/farmacología , Rhodotorula/efectos de los fármacos , Candida/metabolismo , Candida/ultraestructura , Catalasa/metabolismo , Medios de Cultivo/farmacología , Microscopía Electrónica de Rastreo , Microscopía Electrónica de Transmisión , Estrés Oxidativo , Rhodotorula/enzimología , Rhodotorula/ultraestructura , Estrés Fisiológico , Superóxido Dismutasa/metabolismo
17.
FEMS Immunol Med Microbiol ; 55(3): 396-403, 2009 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-19170752

RESUMEN

Onychomycosis is a dermatological problem of high prevalence that mainly affects the hallux toenail. Onychomycosis caused by the yeast Rhodotorula mucilaginosa was identified using colony morphology, light microscopy, urease and carbohydrate metabolism in a 57-year-old immunocompetent patient from Rio de Janeiro, Brazil. High-resolution scanning electron microscopy of nail fragments, processed by a noncoating method, led to the observation with fine detail of the structures of both nail and fungus involved in the infection. Yeasts were mainly found inside grooves in the nail. Budding yeasts presented a spiral pattern of growth and blastoconidia were found in the nail groove region. Keratinase assays and keratin enzymography revealed that this isolate was highly capable of degrading keratin. Antifungal susceptibility tests showed that the fungus was susceptible to low concentrations of amphotericin B and 5-flucytosine and resistant to high concentrations of fluconazole, itraconazole, voriconazole and terbinafine. These findings showed data for the first time concerning the interaction of R. mucilaginosa in toenail infection and suggest that this emerging yeast should also be considered an opportunistic primary causative agent of onychomycosis.


Asunto(s)
Antifúngicos/farmacología , Onicomicosis/microbiología , Rhodotorula/efectos de los fármacos , Rhodotorula/ultraestructura , Brasil , Farmacorresistencia Fúngica , Humanos , Queratinas/metabolismo , Masculino , Pruebas de Sensibilidad Microbiana , Microscopía Electrónica de Rastreo , Persona de Mediana Edad , Técnicas de Tipificación Micológica , Rhodotorula/aislamiento & purificación
18.
Rev Argent Microbiol ; 40(4): 193-7, 2008.
Artículo en Inglés | MEDLINE | ID: mdl-19213239

RESUMEN

We studied fatty acids (FAs) profiles in six carotenoid-producing yeast species isolated from temperate aquatic environments in Patagonia. Total FAs ranged from 2 to 15% of dry biomass. Linoleic, oleic, palmitic and alpha-linolenic acids were the major FAs constituents, which accounted for as much as 40%, 34%, 13% and 9% of total FAs, respectively. The proportion of each FA varied markedly depending on the taxonomic affiliation of the yeast species and on the culture media used. The high percentage of polyunsaturated fatty acids (PUFAs) found in Patagonian yeasts, in comparison to other yeasts, is indicative of their cold-adapted metabolism. Our results suggest that Patagonian yeasts may be considered an interesting source of essential PUFAs.


Asunto(s)
Carotenoides/biosíntesis , Frío , Ácidos Grasos/análisis , Levaduras/química , Adaptación Fisiológica , Argentina , Medios de Cultivo/farmacología , Ácidos Grasos Insaturados/análisis , Agua Dulce/microbiología , Ácido Linoleico/análisis , Ácido Oléico/análisis , Ácido Palmítico/análisis , Rhodotorula/química , Rhodotorula/efectos de los fármacos , Rhodotorula/aislamiento & purificación , Rhodotorula/metabolismo , Especificidad de la Especie , Microbiología del Agua , Levaduras/efectos de los fármacos , Levaduras/aislamiento & purificación , Levaduras/metabolismo , Ácido alfa-Linolénico/análisis
19.
Med Mycol ; 46(6): 547-56, 2008 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-19180725

RESUMEN

The emergence of less common fungal pathogens has been increasingly reported in the last decade. We describe 25 cases of Rhodotorula spp. isolated from blood cultures at a large Brazilian tertiary teaching hospital from 1996-2004. We also investigated the in vitro activity of four antifungal drugs, using a standardized method. The median age of patients was 43 years. The majority of patients (88%) had a central venous catheter (CVC) and 10 (40%) were recipients of a bone marrow transplant. The episode was classified as a bloodstream infection (BSI) in 80% of the patients. Amphotericin B deoxycholate was the most common antifungal used and CVC was removed in 89.5% of the patients. Death occurred in four patients (17.4%), all classified as BSI. All strains were identified as R. mucilaginosa by conventional methods. Misidentification of the species was observed in 20% and 5% of the strains with the Vitek Yeast Biochemical Card and API 20C AUX systems, respectively. Amphotericin B demonstrated good in vitro activity (MIC50/90, 0.5 microg/ml) and the MICs for fluconazole were high for all strains (MIC50/90, >64 microg/ml).


Asunto(s)
Candidiasis/microbiología , Fungemia/microbiología , Rhodotorula/aislamiento & purificación , Adolescente , Adulto , Anciano , Anfotericina B/farmacología , Antifúngicos/farmacología , Brasil , Candidiasis/tratamiento farmacológico , Candidiasis/mortalidad , Niño , Preescolar , Femenino , Estudios de Seguimiento , Fungemia/tratamiento farmacológico , Fungemia/mortalidad , Humanos , Masculino , Pruebas de Sensibilidad Microbiana , Persona de Mediana Edad , Estudios Retrospectivos , Rhodotorula/efectos de los fármacos , Adulto Joven
20.
Clin Infect Dis ; 43(6): e60-3, 2006 Sep 15.
Artículo en Inglés | MEDLINE | ID: mdl-16912936

RESUMEN

We reviewed demographic data, risk factors, treatment, and outcomes associated with Rhodotorula fungemia in a tertiary care hospital during 2002-2005. Rhodotorula species caused fungemic episodes in 7 patients during the 4-year period that we studied. The most common predisposing factors were patients with hematological and solid malignancy receiving corticosteroids and cytotoxic drugs, the presence of central venous catheters, and the use of broad-spectrum antibiotics. Because of Rhodotorula species's intrinsic resistance to triazole and echinocandin antifungal agents, patients receiving fluconazole and caspofungin might be susceptible to the development of breakthrough Rhodotorula fungemia.


Asunto(s)
Fungemia/epidemiología , Rhodotorula , Adolescente , Corticoesteroides/uso terapéutico , Adulto , Antibacterianos/uso terapéutico , Antifúngicos/uso terapéutico , Antineoplásicos/uso terapéutico , Caspofungina , Cateterismo Venoso Central/efectos adversos , Niño , Farmacorresistencia Fúngica , Equinocandinas , Femenino , Fluconazol/uso terapéutico , Fungemia/complicaciones , Fungemia/tratamiento farmacológico , Hospitales , Humanos , Lipopéptidos , Masculino , Persona de Mediana Edad , Neoplasias/complicaciones , Neoplasias/tratamiento farmacológico , Péptidos Cíclicos/uso terapéutico , Estudios Retrospectivos , Rhodotorula/efectos de los fármacos , Factores de Riesgo , Resultado del Tratamiento
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