Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 12 de 12
Filtrar
Mais filtros










Intervalo de ano de publicação
1.
Rev. peru. biol. (Impr.) ; 30(1)ene. 2023.
Artigo em Inglês | LILACS-Express | LILACS | ID: biblio-1450328

RESUMO

Trehalose is a type of carbohydrate that protects against different types of stress and is also used as a source of carbon storage in prokaryotes. There are four different ways of synthesizing trehalose in Acidithiobacillus ferrivorans and two in Acidithiobacillus ferrooxidans, but its purpose remains unknown. This study aimed to measure the production of trehalose under different conditions by quantifying it in three culture media at two different temperatures. The growth kinetics of both species were also assessed, and the trehalose concentration was analysed during the early stationary phase using an enzymatic method. The results showed that the modified 9K medium with ferrous iron at 28°C had the highest production of trehalose, with A. ferrivorans CF27 having a higher production of 0.34 µmol/mg protein compared to A. ferrooxidans ATCC 23270 at 0.31 µmol/mg protein. When using CuS, the production of trehalose was lower, with 0.02 and 0.03 µmol/mg protein for A. ferrivorans CF27 and A. ferrooxidans ATCC 23270, respectively, while no trehalose was detected in the presence of zinc. At 15°C, the enzymatic method did not detect any trehalose in all three culture media, this would indicate that this carbohydrate does not protect against low temperatures in either species.


La trehalosa es un tipo de carbohidrato, que en procariotas protege contra diferentes tipos de estrés y también se utiliza como fuente de almacenamiento de carbono. Hay cuatro formas diferentes de sintetizar trehalosa en Acidithiobacillus ferrivorans y dos en Acidithiobacillus ferrooxidans, pero su propósito sigue siendo desconocido. Este estudio tuvo como objetivo medir la producción de trehalosa en diferentes condiciones mediante su cuantificación en tres medios de cultivo a dos temperaturas diferentes. También se evaluó la cinética de crecimiento de ambas especies y se analizó la concentración de trehalosa durante la fase estacionaria temprana mediante un método enzimático. Los resultados mostraron que el medio 9K modificado con hierro ferroso a 28 °C tuvo la mayor producción de trehalosa, con A. ferrivorans CF27 con una mayor producción de 0.34 µmol/mg de proteína en comparación con A. ferrooxidans ATCC 23270 a 0.31 µmol/mg de proteína. Al utilizar CuS, la producción de trehalosa fue menor, con 0.02 y 0.03 µmol/mg de proteína para A. ferrivorans CF27 y A. ferrooxidans ATCC 23270, respectivamente, mientras que en presencia de zinc no se detectó trehalosa. A 15°C, el método enzimático no detectó trehalosa en los tres medios de cultivo, lo que indicaria que este carbohidrato no protege contra las bajas temperaturas en ninguna de las especies.

2.
Rev. chil. obstet. ginecol. (En línea) ; 86(6): 516-520, dic. 2021. tab
Artigo em Espanhol | LILACS | ID: biblio-1388692

RESUMO

INTRODUCCIÓN Y OBJETIVO: El rol de la testosterona exógena en la función sexual femenina ha sido estudiado durante muchos años, con resultados contradictorios. En el último tiempo se ha promovido el uso de pellets de testosterona como una solución para mejorar la libido femenina, la cognición, la fuerza muscular y los sistemas cardiovascular y óseo, e incluso evitar el envejecimiento. Por ello, revisamos las publicaciones para tratar de responder si esto es una moda o el tratamiento más innovador del último tiempo. MÉTODO: Se analizaron las bases de datos PubMed/Medline, Trip Database, Cochrane, SciELO, Scopus, UpToDate, Ovid, ProQuest, Science Direct y ResearchGate. RESULTADOS: De acuerdo con la evidencia, la mejor testosterona disponible es la transdérmica y debe ser usada solo en el trastorno del deseo sexual hipoactivo (TDSH). Los trabajos que evalúan los pellets de testosterona tienen sesgos metodológicos importantes. Si bien son útiles para mejorar la función sexual femenina, producen concentraciones plasmáticas suprafisiológicas de testosterona, por lo que no se puede establecer su seguridad a largo plazo. Tampoco hay datos suficientes que avalen su uso para mejorar el rendimiento cognitivo y el bienestar general, en el tratamiento de enfermedades cardiovasculares o en la prevención de enfermedad ósea. CONCLUSIONES: La testosterona solo se recomienda en el tratamiento del TDSH por vía transdérmica. No recomendamos el uso de pellets de testosterona para el tratamiento de la disfunción sexual ni como hormona antienvejecimiento, ya que no hay estudios consistentes sobre su seguridad, eficacia y efectos adversos a largo plazo.


INTRODUCTION AND OBJECTIVE: The role of exogenous testosterone in female sexual function has been studied for many years with contradictory results. In recent times, the use of testosterone pellets has been promoted as a solution to improve female libido, cognition, muscle strength, cardiovascular system, bone and even prevent aging. Therefore, we will review the publications in order to answer whether this is a fad or the most innovative treatment of recent times. METHOD: The databases PubMed/Medline, Trip Database, Cochrane, SciELO, Scopus, UpToDate, Ovid, ProQuest, Science Direct and ResearchGate were analyzed. RESULTS: So far, the evidence best testosterone available is transdermal testosterone and that it should be used only in hypoactive sexual desire disorder (HSDD). Papers evaluating testosterone pellets have significant methodological biases. While they are useful in improving female sexual function, they produce supra-physiological plasma levels of testosterone, so their long-term safety cannot be established. There is also insufficient data to support their use in improving cognitive performance and general well-being, treatment of cardiovascular disease or prevention of bone disease. CONCLUSIONS: Testosterone is only recommended for the tratment of HSDD via the transdermal route. We do not recommended the use of testosterone pellets for the treatment of sexual dysfunction or as an anti aging hormone, as there are no consistent studies on its safety, efficacy, and long-term adverse effects.


Assuntos
Humanos , Feminino , Testosterona/administração & dosagem , Disfunções Sexuais Psicogênicas/tratamento farmacológico , Implantes de Medicamento , Androgênios/biossíntese
3.
Con-ciencia (La Paz) ; 9(2): [1-14], nov. 2021.
Artigo em Espanhol | LILACS | ID: biblio-1349123

RESUMO

INTRODUCCIÓN: la presente revisión bibliográfica referencia diversos estudios que describen la biosíntesis de alcaloides en la familia Amaryllidacea. Se toman en cuenta los procesos enzimáticos que rigen la biosíntesis de los metabolitos secundarios y los métodos de estimulación y mejoramiento de la producción de alcaloides. OBJETIVO: determinar, mediante una amplia revisión bibliográfica, los posibles métodos de mejora de la producción de alcaloides. METODOLOGÍA: se realizó una revisión bibliográfica de los documentos más relevantes sobre la biosíntesis de alcaloides de Amaryllidaceae. RESULTADOS: en esta revisión, es posible establecer una metodología de mejoramiento de la producción de alcaloides tipo crinina/haemantamina en plantas de la familia Amaryllidaceae nativas de Bolivia y evaluar la posibilidad de aplicarla con éxito para la obtención de mejores rendimientos.(AU)


INTRODUCTION: the referenced studies in this bibliographic review show the alkaloid biosynthesis in the Amaryllidaceae family. Some of the processes involved in the improvement and stimulation of alkaloid production are also taken into account and the enzymatic processes that rule secondary metabolites synthesis are described. OBJECTIVE: to determine, through a bibliographic review, possible methods of improving alkaloid production. METHODS: a wide bibliographic review of the most relevant articles about the Amaryllidaceae family alkaloid production was applied. RESULTS: it was possible to demonstrate that there is the possibility to stablish and develop a successful method to improve the production of crinine/haemanthamine type alkaloids in the Bolivian native family Amaryllidacea and to evaluate the possibility of applying it successfully to obtain better yields.(AU)


Assuntos
Plantas , Alcaloides de Amaryllidaceae , Alcaloides , Registros , Amaryllidaceae
4.
Rev Iberoam Micol ; 36(3): 120-128, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31443947

RESUMO

BACKGROUND: In the last three decades the species of Candida have been of great interest due to the high mortality rates that they cause in immunocompromised and hospitalized patients. These species are opportunistic pathogens and they have inhabited other environments long before colonizing human cells. Among these environments we find wastewater from mines, and water from aquifers and soils that contain high concentrations of precious metals as well as toxic and base metals. AIMS: The aim of this study was to assess whether Candida albicans and Candida glabrata are able to maintain homeostasis in the presence of zinc, copper, cobalt or silver. METHODS: To achieve the objective, each of the Candida species was exposed to every single metal individually in a salt solution. Subsequently the treated cells were lysed to evaluate the compounds formed by means of Scanning Electron Microscopy-Energy Dispersive X-ray spectroscopy (SEM-EDS). RESULTS: When analyzing the compounds that both C. albicans and C. glabrata formed in the presence of each of the metals, we found that they had synthesized silver sulfide (Ag2S), cobalt sulfate (CoSO4), zinc phosphate (Zn3(PO4)2), or copper oxide (CuO). CONCLUSIONS: Our results indicate that both C. albicans and C. glabrata have enzymatic and non-enzymatic mechanisms that allow them to achieve homeostasis in a different specific manner for each of the single metals to which they were exposed. To our knowledge, this is the first work reporting that C. albicans and C. glabrata can reduce different metals, with the subsequent formation of sulfides, sulfates, phosphates and oxides. This ability, developed over time by these Candida species, is probably a kind of biochemical mechanism in order to survive and colonize many different environments, from water or soil to humans. For this reason, C. albicans and C. glabrata make up an excellent model of study, both from a medical and biotechnical point of view.


Assuntos
Candida albicans/metabolismo , Candida glabrata/metabolismo , Cobalto/metabolismo , Cobre/metabolismo , Prata/metabolismo , Zinco/metabolismo , Homeostase , Fosfatos/metabolismo , Compostos de Prata/metabolismo , Compostos de Zinco/metabolismo
5.
Rev. argent. microbiol ; 51(2): 103-109, jun. 2019. ilus, graf, tab
Artigo em Inglês | LILACS | ID: biblio-1013358

RESUMO

In the present work, the biosynthesis of silver-nanoparticles (AgNP) was evaluated using the aqueous extract from Justicia spicigera. The obtained silver nanoparticles were characterized using UV-visible spectroscopic techniques, energy dispersive X-ray spectrometers (EDS), zeta potential and dynamic light scattering. The antimicrobial activity of biosynthesized AgNP was tested against foodborne bacteria (Bacillus cereus, Klebsiella pneumoniae and Enterobacter aerogenes) and phytopathogenic fungi (Colletotrichum sp., Fusarium solani, Alternaria alternata and Macrophomina phaseolina). The elemental profile of synthesized nanoparticles using J. spicigera shows higher counts at 3 keV due to silver, confirming the formation of silver nanoparticles. Scanning electron microscopy (SEM) analysis showed a particle size between 86 and 100 nm with spherical morphology. AgNP showed effective antibacterial and antifungal activity against the tested organisms principally with B. cereus, K. pneumoniae, E. aerogenes, A. alternata and M. phaseolina. Therefore, further studies are needed to confirm the potential of AgNP from J. spicigera in the control of indicator organisms under field conditions.


En el presente trabajo se evaluó la biosíntesis de nanopartículas de plata (AgNP) en presencia de una sal de plata y extractos acuosos de Justicia spicigera. Las nanopartículas así obtenidas fueron caracterizadas mediante técnicas espectroscópicas UV-visibles, espectrómetros de rayos X de energía dispersiva (EDS), potencial zeta y dispersión de luz dinámica. La actividad antimicrobiana de las AgNP biosintetizadas se probó frente a diversas bacterias transmitidas por alimentos (Bacillus cereus, Klebsiella pneumoniae y Enterobacter aerogenes) y hongos fitopatógenos (Colletotrichum sp., Fusarium solani, Alternaria alternata y Macrophomina phaseolina). El perfil elemental de las nanopartículas sintetizadas utilizando el extracto de J. spicigera mostró valores altos a 3 keV, lo que confirma la formación de nanopartículas de plata. El análisis por microscopía electrónica de barrido (SEM) reveló un tamaño de partícula entre 86 y 100 nm, con morfología esférica. Las AgNP mostraron una actividad antibacteriana y antifúngica efectiva contra los organismos evaluados, principalmente contra B. cereus, K. pneumoniae, E. aerogenes, A. alternata y M. phaseolina. Se necesitan más estudios para confirmar el potencial de las AgNP derivadas de J. spicigera en el control de organismos indicadores en condiciones de campo.


Assuntos
Prata/uso terapêutico , Controle Biológico de Vetores , Nanopartículas Metálicas/análise , Doenças Transmitidas por Alimentos/microbiologia , Doenças Transmitidas por Alimentos/prevenção & controle , Anti-Infecciosos , Antifúngicos
6.
Rev Argent Microbiol ; 51(2): 103-109, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30029815

RESUMO

In the present work, the biosynthesis of silver-nanoparticles (AgNP) was evaluated using the aqueous extract from Justicia spicigera. The obtained silver nanoparticles were characterized using UV-visible spectroscopic techniques, energy dispersive X-ray spectrometers (EDS), zeta potential and dynamic light scattering. The antimicrobial activity of biosynthesized AgNP was tested against foodborne bacteria (Bacillus cereus, Klebsiella pneumoniae and Enterobacter aerogenes) and phytopathogenic fungi (Colletotrichum sp., Fusarium solani, Alternaria alternata and Macrophomina phaseolina). The elemental profile of synthesized nanoparticles using J. spicigera shows higher counts at 3keV due to silver, confirming the formation of silver nanoparticles. Scanning electron microscopy (SEM) analysis showed a particle size between 86 and 100nm with spherical morphology. AgNP showed effective antibacterial and antifungal activity against the tested organisms principally with B. cereus, K. pneumoniae, E. aerogenes, A. alternata and M. phaseolina. Therefore, further studies are needed to confirm the potential of AgNP from J. spicigera in the control of indicator organisms under field conditions.


Assuntos
Bactérias , Agentes de Controle Biológico , Microbiologia de Alimentos , Fungos , Justicia/metabolismo , Nanopartículas Metálicas , Prata/metabolismo , Doenças das Plantas/microbiologia
7.
Bol. latinoam. Caribe plantas med. aromát ; 17(1): 36-52, ene. 2018. ilus, graf, tab
Artigo em Inglês | LILACS | ID: biblio-915054

RESUMO

A comparative study of antioxidant properties, platelet antiaggregation activity and transcriptional analysis of flavonoid biosynthesis genes were performed in Fragaria x ananassa, F. vesca and F. chiloensis subsp chiloensis f. chiloensis and f. patagonica. Furthermore, differences in flavonoid content were found by UHPLC-MS. The highest free radical scavenging activity by DPPH assay was observed in F. chiloensis f. chiloensis, meanwhile, F. vesca presented the highest antioxidant capacity by FRAP. Biosynthetic flavonoids- related transcripts were higher abundant in F. x ananassa and lower in F. vesca. Additionally, all strawberry extracts showed antiaggregant effect (1 mg mL-1), but F. vesca and F. chiloensis subsp. chiloensis f. patagonica were still active at lower concentration. This study suggests that platelet antiaggregation effect of different strawberries could be due to isoflavones and flavonoids precursors in addition to anthocyanins. Results could usefully to take decisions in future breeding programs to improve the content of healthy compounds in strawberry fruits.


Se realizó un estudio comparativo de propiedades antioxidantes, actividad de antiagregacion plaquetaria, análisis transcripcional de genes de biosíntesis de flavonoides y contenido de estos en Fragaria x ananassa, F. vesca and F. chiloensis subsp chiloensis f. chiloensis and f. patagonica. La mayor actividad removedora de radicales libres por DPPH se observó en F. chiloensis f. chiloensis, mientras F. vesca presentó la mayor capacidad antioxidante mediante FRAP. Transcritos relacionados con biosíntesis de flavonoides fueron mas abundantes en F. x ananassa y menores en F. vesca. Adicionalmente, todos los extractos de frutillas mostraron efectos antiagregante (1 mg mL-1), pero F. vesca and F. chiloensis subsp. chiloensis f. patagonica fueron activos a concentraciones menores. Este estudio sugiere que efectos de antiagregación plaquetaria en distintas frutillas podría deberse a isoflavonas y precursores de flavonoides además de antocianinas. Los resultados podrían ser útiles en programas de mejoramiento genético para mejorar el contenido de compuestos saludables en frutilla.


Assuntos
Extratos Vegetais/química , Fragaria/química , Antioxidantes/química , Flavonoides/análise , Flavonoides/genética , Flavonoides/metabolismo , Inibidores da Agregação Plaquetária/farmacologia , Extratos Vegetais/farmacologia , Expressão Gênica , Sequestradores de Radicais Livres , Cromatografia Líquida de Alta Pressão/métodos , Recuperação de Fluorescência Após Fotodegradação , Reação em Cadeia da Polimerase em Tempo Real , Antioxidantes/farmacologia
8.
Int. j. morphol ; 35(1): 26-33, Mar. 2017. ilus
Artigo em Espanhol | LILACS | ID: biblio-840927

RESUMO

En los últimos años microorganismos tales como hongos, levaduras y, en especial, las bacterias han sido utilizadas para realizar biosíntesis de nanopartículas. Existen varios tipos de bacterias descritas como productoras de nanopartículas, sin embargo, las bacterias psicrófilas y psicrotolerantes no han sido ampliamente estudiadas, aun cuando su utilización en la producción de nanopartículas podría entregar ventajas relacionadas con su estabilidad, el gasto energético de su producción, al mismo tiempo que son una alternativa amigable con el medio ambiente. Este artículo entrega una breve revisión de las bacterias antárticas psicrófilas y psicrotolerantes sintetizadoras de nanopartículas, los posibles mecanismos que se asocian a esta síntesis y perspectivas futuras relacionadas a la biosíntesis bacteriana de nanopartículas.


In recent years microorganisms as fungi, yeasts and especially bacteria have been used to produce nanoparticles biosynthesis. Several types of bacteria are described as nanoparticles producers, however, psychrophilic and psychrotolerant bacterias have not been studied widely, although its use in the production of nanoparticles could provide advantages related to the stability of nanoparticles, energy expenditure on its production, while being an environmentally friendly alternative. This article provides a brief overview of Antarctic bacterias, both psychrophilic and psychrotolerant that synthesis nanoparticles, possible mechanisms associated to this synthesis and future perspectives related to bacterial biosynthesis of nanoparticles.


Assuntos
Bactérias/metabolismo , Nanopartículas/química
9.
Rev. peru. med. exp. salud publica ; 32(1): 11-18, ene.-mar. 2015. tab
Artigo em Espanhol | LILACS, LIPECS, INS-PERU | ID: lil-745214

RESUMO

Objetivos. Analizar la participación de la caperuza metil-guanosín-trifosfato (5´cap) y de la región inicial del ARN genómico del virus dengue serotipo 2 (DENV-2) genotipo Americano en la traducción, utilizando un sistema libre de células obtenido de placenta humana. Materiales y métodos. Se preparó el plásmido recombinante pTZ18R-D2 conteniendo el ADN que codifica la 5´UTR y los primeros 201 nucleótidos de la cápside viral. Este plásmido se utilizó para transcribir el ARN correspondiente (ARN-D2), sin la 5´cap. El ARN-D2 fue traducido en un sistema constituido por la fracción posmitocondrial (S-30) de placenta humana y se evaluó la incorporación de [14C] aminoácidos en presencia del ARN-D2 y en su ausencia (control). Se diseñaron siete oligonucleótidos antisentido (OAs1-7) dirigidos contra secuencias de las estructuras SLA, SLB y cHP del ARN-D2 y se analizó el efecto de los mismos sobre la traducción ARN-D2. Resultados.El ARN-D2 produjo un incremento significativo (p<0,001) en la incorporación de [14C] aminoácidos, con estimulación del 75% de la actividad traduccional respecto al control. El análisis de los productos de traducción mostró un pico de incorporación correspondiente a péptidos con peso molecular aparente cercano al esperado (7,746 kDa). El OAs5, complementario a una secuencia de la estructura SLB del ARN-D2, inhibió completamente la traducción. Conclusiones. El ARN-D2 fue traducido de manera específica y eficiente, bajo condiciones semejantes a las intracelulares en humanos, por un mecanismo alternativo independiente de la 5´cap, que involucraría a la estructura SLB. Este mecanismo podría considerarse como blanco en el desarrollo de terapias antisentido para inhibir la reproducción del virus.


Objetives. To analyze the involvement of methyl guanosine triphosphate cap (5Æcap) and the start site of the genomic RNA of Dengue virus serotype 2 (DENV-2) American genotype in translation, using a cell-free system prepared from human placenta. Materials and methods. The recombinant plasmid pTZ18R-D2 was prepared containing DNA encoding the 5ÆUTR and the first 201 nucleotides of the viral capsid. This plasmid was used to transcribe the corresponding RNA (RNA-D2) without the 5Æ cap. The RNA-D2 was translated in a system consisting of the postmitochondrial fraction (S-30) from human placenta and the incorporation of [14C] aminoacids in the presence of RNA-D2 and in its absence (control) was evaluated. Seven antisenseoligonucleotides (OAs1-7) directed against sequences of the SLA, SLB and CHP structures of RNA-D2 were designed and the effect thereof on RNA-D2 translation was analyzed. Results.The RNA-D2 produced a significant increase (p<0.001) in the incorporation of [14C] amino acids, with 75% stimulation of translational activity compared to the control. Analysis of the translation products showed peak incorporation corresponding to peptides with apparent molecular weight close to the expected (7.746 kDa).The OAs5, complementary to a sequence of SLB structure of RNA-D2, completely inhibited translation. Conclusions. The RNA-D2 was translated specifically and efficiently under conditions similar to human intracellular conditions, by an alternative 5Æ cap-independent mechanism, which would involve the SLB structure. This mechanism might be seen as an aim in the development of antisense therapies to inhibit virus replication.


Assuntos
Humanos , Biossíntese de Proteínas , Oligonucleotídeos Antissenso , Vírus da Dengue
10.
Biomédica (Bogotá) ; 34(supl.1): 41-49, abr. 2014. ilus, tab
Artigo em Inglês | LILACS | ID: lil-712420

RESUMO

Introduction: Aminoglycosides like streptomycin are well-known for binding at specific regions of ribosome RNA and then acting as translation inhibitors. Nowadays, several pathogens have been detected to acquire an undefined strategy involving mutation at non structural ribosome genes like those acting as RNA methylases. rsmG is one of those genes which encodes an AdoMet-dependent methyltransferase responsible for the synthesis of m 7 G527 in the 530 loop of bacterial 16S rRNA. This loop is universally conserved, plays a key role in ribosomal accuracy, and is a target for streptomycin binding. Loss of the m 7 G527 modification confers low-level streptomycin resistance and may affect ribosomal functioning. Objectives: After taking into account genetic information indicating that some clinical isolates of human pathogens show streptomycin resistance associated with mutations at rsmG , we decided to explore new hot spots for mutation capable of impairing the RsmG in vivo function and of promoting low-level streptomycin resistance. Materials and methods: To gain insights into the molecular and genetic mechanism of acquiring this aminoglycoside resistance phenotype and the emergence of high-level streptomycin resistance in rsmG mutants, we mutated Escherichia coli rsmG and also performed a genotyping study on rpsL from several isolates showing the ability to grow at higher streptomycin concentrations than parental strains. Results: We found that the mutations at rpsL were preferentially present in these mutants, and we observed a clear synergy between rsmG and rpsL genes to induce streptomycin resistance. Conclusion: We contribute to understand a common mechanism that is probably transferable to other ribosome RNA methylase genes responsible for modifications at central sites for ribosome function.


Introducción. Los aminoglucósidos son moléculas antibióticas capaces de inhibir la síntesis de proteínas bacterianas tras su unión al ribosoma procariota. La resistencia a aminoglucósidos está clásicamente asociada a mutaciones en genes estructurales del ribosoma bacteriano; sin embargo, varios estudios recientes han demostrado, de forma recurrente, la presencia de un nuevo mecanismo dependiente de mutación que no involucra genes estructurales. El gen rsmG es uno de ellos y se caracteriza por codificar una metiltransferasa que sintetiza el nucleósido m 7 G527 localizado en el loop 530 del ribosoma bacteriano, este último caracterizado como sitio preferencial al cual se une la estreptomicina. Objetivo. Partiendo de las recientes asociaciones clínicas entre las mutaciones en el gen rsmG y la resistencia a estreptomicina, este estudio se propuso la caracterización de nuevos puntos calientes de mutación en este gen que puedan causar resistencia a estreptomicina usando Escherichia coli como modelo de estudio. Materiales y métodos. Se indagó sobre el mecanismo genético y molecular por el cual se adquiere la resistencia a estreptomicina y su transición a la resistencia a altas dosis mediante mutagénesis dirigida del gen rsmG y genotipificación del gen rpsL . Resultados. Se encontró que la mutación N39A en rsmG inactiva la proteína y se reportó un nuevo conjunto de mutaciones en rpsL que confieren resistencia a altas dosis de estreptomicina. Conclusiones. Aunque los mecanismos genéticos subyacentes permanecen sin esclarecer, se concluyó que dichos patrones secuenciales de mutación podrían tener lugar en otros genes modificadores del ARN bacteriano debido a la conservación evolutiva y al papel crítico que juegan tales modificaciones en la síntesis de proteínas.


Assuntos
Aminoglicosídeos/farmacologia , Antibacterianos/farmacologia , Farmacorresistência Bacteriana/genética , Proteínas de Escherichia coli/genética , Mutação de Sentido Incorreto , Metiltransferases/genética , Mutação Puntual , Processamento Pós-Transcricional do RNA/genética , RNA Bacteriano/metabolismo , /metabolismo , Estreptomicina/farmacologia , Sequência de Aminoácidos , Sítios de Ligação/genética , Domínio Catalítico/genética , Proteínas de Escherichia coli/química , Proteínas de Escherichia coli/metabolismo , Escherichia coli/efeitos dos fármacos , Escherichia coli/enzimologia , Metilação , Modelos Moleculares , Dados de Sequência Molecular , Metiltransferases/química , Metiltransferases/metabolismo , Filogenia , Conformação Proteica , RNA Bacteriano/genética , /genética , Proteínas Recombinantes de Fusão/genética , Proteínas Recombinantes de Fusão/metabolismo , Proteínas Ribossômicas/genética , Proteínas Ribossômicas/metabolismo , S-Adenosilmetionina/metabolismo , Alinhamento de Sequência , Análise de Sequência de DNA , Deleção de Sequência , Homologia de Sequência de Aminoácidos
11.
Rev Iberoam Micol ; 31(1): 16-21, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24257473

RESUMO

The global epidemiology of fungal infections is changing. While overall, Candida albicans remains the most common pathogen; several institutions in Europe, Asia and South America have reported the rapid emergence to predominance of Candida parapsilosis. This mini-review examines the impact of gene deletions achieved in C. parapsilosis that have been published to date. The molecular approaches to gene disruption in C. parapsilosis and the molecularly characterized genes to date are reviewed. Similar to C. albicans, factors influencing virulence in C. parapsilosis include adherence, biofilm formation, lipid metabolism, and secretion of hydrolytic enzymes such as lipases, phospholipases and secreted aspartyl proteinases. Development of a targeted gene deletion method has enabled the identification of several unique aspects of C. parapsilosis genes that play a role in host-pathogen interactions - CpLIP1, CpLIP2, SAPP1a, SAPP1b, BCR1, RBT1, CpFAS2, OLE1, FIT-2. This manuscript is part of the series of works presented at the "V International Workshop: Molecular genetic approaches to the study of human pathogenic fungi" (Oaxaca, Mexico, 2012).


Assuntos
Candida/genética , Ácido Aspártico Endopeptidases/genética , Biofilmes , Candida/metabolismo , Candida/patogenicidade , Proteínas de Transporte de Cátions/genética , Ácidos Graxos Dessaturases/genética , Ácido Graxo Sintases/genética , Proteínas Fúngicas/genética , Proteínas Fúngicas/fisiologia , Genes Fúngicos , Glicoproteínas/genética , Interações Hospedeiro-Patógeno/genética , Lipase/genética , Metabolismo dos Lipídeos , Virulência/genética
12.
Rev Iberoam Micol ; 25(3)sept. 2008. tab
Artigo em Espanhol | CUMED | ID: cum-39750

RESUMO

El ácido jasmónico es un regulador del crecimiento de las plantas producidopor algas, microorganismos y plantas superiores, que participa en laactivación de mecanismos de defensa contra patógenos y ante la presenciade heridas en las plantas. En este trabajo se estudió la influencia de larelación carbono:nitrógeno (rC/N: 17, 35 y 70), el tipo de inóculo (esporas omicelio) y la adición de extracto de levadura al medio de cultivo en laproducción de ácido jasmónico por Botryodiplodia theobromae. Los estudiosrevelaron que la producción de ácido jasmónico es estimulada a una rC/N 17.La productividad del ácido jasmónico fue mayor para la inoculación conmicelio y la adición de extracto de levadura al medio de cultivo en 1,7 y 1,3veces, respectivamente(AU)


Jasmonic acid is a native plant growth regulator produced by algae,microorganisms and higher plants. This regulator is involved in the activationof defence mechanisms against pathogens and wounding in plants. Studies concerning the effects of carbon: nitrogen ratio (C/Nr: 17, 35 and 70), type of inoculum (spores or mycelium) and the yeast extract addition in the media on jasmonic acid production by Botryodiplodia theobromae were evaluated. Jasmonic acid production was stimulated at the carbon: nitrogen ratio of 17. jasmonic acid productivity was higher in the media inoculated with mycelium and in the media with yeast extract 1,7 and 1,3 times, respectively(AU)


Assuntos
Carbono/administração & dosagem , Carbono/metabolismo , Misturas Complexas/administração & dosagem , Misturas Complexas/metabolismo , Ciclopentanos/metabolismo , Nitrogênio/administração & dosagem , Nitrogênio/metabolismo , Oxilipinas/metabolismo , Leveduras
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...