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1.
Int. microbiol ; 22(4): 403-409, dic. 2019. graf, tab
Artigo em Inglês | IBECS | ID: ibc-185058

RESUMO

A biofilm is a community of microorganisms attached to a surface and embedded in a matrix of extracellular polymeric substances. Biofilms confer resistance towards conventional antibiotic treatments; thus, there is an urgent need for newer and more effective antimicrobial agents that can act against these biofilms. Due to this situation, various studies have been done to investigate the anti-biofilm effects of natural products including bioactive compounds extracted from microorganisms such as Actinobacteria. This review provides an insight into the anti-biofilm potential of Actinobacteria against various pathogenic bacteria, which hopefully provides useful information, guidance, and improvements for future antimicrobial studies. Nevertheless, further research on the anti-biofilm mechanisms and compound modifications to produce more potent anti-biofilm effects are required


No disponible


Assuntos
Actinobacteria/isolamento & purificação , Streptomyces/fisiologia , Biofilmes/efeitos dos fármacos , Testes de Sensibilidade Microbiana , Actinobacteria/genética , Actinobacteria/efeitos dos fármacos
2.
Int. microbiol ; 22(4): 451-459, dic. 2019. graf, tab
Artigo em Inglês | IBECS | ID: ibc-185063

RESUMO

An endophytic actinomycete strain SKH1-2 isolated from Musa (ABB) cv. 'Kluai Sao Kratuep Ho' collected in Suphan Buri province (14° 54′ 22.5″ N/100° 04′ 50″ E), Thailand, was identified as Streptomyces pseudovenezuelae based on phenotypic and chemotaxonomic characteristics, and 16S rRNA sequence analyses. A chemical investigation led to the isolation of two polyketide molecules from the n-butanol crude extract of the strain SKH1-2 culture broth. The compounds were purified using various chromatographic techniques and identified using spectroscopic methods compared with earlier published data. Compound 1, chartreusin, is known as an anti-Gram (+) bacterial compound and was active against Bacillus subtilis ATCC 6633, Kocuria rhizophila ATCC 9341 and Staphylococcus aureus ATCC 6538p with MIC values of 3.1, 1.6 and 12.5 μg/mL, respectively. Compound 2, lumichrome, did not show activity against all tested microbes. To our knowledge, this is the first report of chartreusin and lumichrome isolated from S. pseudovenezuelae. Taken together, it could be proved that Thai plant species are valuable reservoirs of interesting endophytic actinomycetes producing several interesting biologically active compounds


No disponible


Assuntos
Policetídeos/isolamento & purificação , Streptomyces/isolamento & purificação , RNA Ribossômico 16S/isolamento & purificação , Staphylococcus aureus/isolamento & purificação , Streptomyces/classificação , Musa/química , Musa/microbiologia , RNA Ribossômico 16S/química , Análise Espectral
3.
Int. microbiol ; 22(3): 343-353, sept. 2019. ilus, graf, tab
Artigo em Inglês | IBECS | ID: ibc-184841

RESUMO

The objective of the present study was to isolate Actinobacteria, preferably Streptomyces spp. from the rhizosphere soils of three ethno-medicinal plants collected in Serbia (Papaver rhoeas, Matricaria chamomilla, and Urtica dioica) and to screen their antifungal activity against Candida spp. Overall, 103 sporulating isolates were collected from rhizosphere soil samples and determined as Streptomyces spp. Two different media and two extraction procedures were used to facilitate identification of antifungals. Overall, 412 crude cell extracts were tested against Candida albicans using disk diffusion assays, with 42% (43/103) of the strains showing the ability to produce antifungal agents. Also, extracts inhibited growth of important human pathogens: Candida krusei, Candida parapsilosis, and Candida glabrata. Based on the established degree and range of antifungal activity, nine isolates, confirmed as streptomycetes by 16S rRNA sequencing, were selected for further testing. Their ability to inhibit Candida growth in liquid culture, to inhibit biofilm formation, and to disperse pre-formed biofilms was assessed with active concentrations from 8 to 250 μg/mL. High-performance liquid chromatographic profiles of extracts derived from selected strains were recorded, revealing moderate metabolic diversity. Our results proved that rhizosphere soil of ethno-medicinal plants is a prolific source of streptomycetes, producers of potentially new antifungal compounds


No disponible


Assuntos
Antifúngicos/metabolismo , Candida/efeitos dos fármacos , Rizosfera , Microbiologia do Solo , Streptomyces/isolamento & purificação , Candida/crescimento & desenvolvimento , RNA Ribossômico 16S/genética , Sérvia , Streptomyces/classificação , Streptomyces/genética , Análise por Conglomerados , DNA Bacteriano/química , DNA Bacteriano/genética , DNA Ribossômico/química , DNA Ribossômico/genética
4.
Rev. iberoam. micol ; 29(1): 29-33, ene.-mar. 2012.
Artigo em Espanhol | IBECS | ID: ibc-96548

RESUMO

Antecedentes: El cribado farmacológico y el uso de productos naturales para el tratamiento de las enfermedades humanas tiene un largo historial que comienza en la medicina tradicional y se extiende hasta los fármacos modernos. La mayoría de los fármacos modernos proceden principalmente de productos naturales. Objetivo. El objetivo del presente estudio fue valorar la actividad inhibidora of 5-(2,4-dimetilbencil) pirrolidin-2-uno (DMBPO) extraído de Streptomyces VITSVK5 sp. marino aislado de muestras de sedimento recolectadas en la costa de Marakkanam de la bahía de Bengala, India. Métodos. El compuesto principal se aisló mediante extracción bioactiva guiada y se purificó mediante cromatografía de columna de gel de sílice. La dilucidación estructural del compuesto principal se efectuó utilizando datos espectrales de las técnicas UV, FT-IR, 1H NMR, 13C NMR, DEPT y HR-MS. Resultados. El cribado sistemático de los aislamientos en busca de actividad antimicrobiana dio lugar a la identificación de una cepa potencial, Streptomyces VITSVK5 sp. (GQ848482). Con la extracción bioactiva guiada se obtuvo un compuesto DMBPO y su actividad inhibidora se examinó frente a cepas bacterianas y fúngicas seleccionadas. DMBPO mostró una actividad máxima frente a Escherichia coli con un valor de la concentración inhibitoria mínima (CIM) de 187mg/ml, seguida de Klebsiella pneumoniae (CIM de 220mg/ml y zona de inhibición de 10,3mm), Staphylococcus aureus (CIM>1.000mg/ml y zona de inhibición de 4,4mm) y Bacillus subtilis (CIM de 850mg/ml y zona de inhibición de 2,6mm). Además, se puso de relieve que DMBPO también fue un inhibidor potente de los patógenos fúngicos oportunistas. Se demostró una actividad máxima frente a Aspergillus niger con un valor de CIM de 1mg/ml y una zona de inhibición de 28mm. Conclusión. El resultado del presente estudio indica que DMBPO posee actividad antibiótica frente a patógenos bacterianos y fúngicos seleccionados y exhibió una mejor actividad frente a hongos que bacterias(AU)


Background. Pharmacological screening and usage of natural products for the treatment of human diseases has had a long history from traditional medicine to modern drugs. The majority of modern drugs are reported to be mostly from natural products. Objective. The aim of the present study was to evaluate the inhibitory activity of 5-(2,4-dimethylbenzyl) pyrrolidin-2-one (DMBPO) extracted from marine Streptomyces VITSVK5 spp. isolated from sediment samples collected at Marakkanam coast of Bay of Bengal, India. Methods. The lead compound was isolated by bioactive guided extraction and purified by silica gel column chromatography. Structural elucidation of the lead compound was carried out by using UV, FT-IR, 1H NMR, 13C NMR, DEPT and HR-MS spectral data. Results. Systematic screening of isolates for antimicrobial activity lead to identification of a potential strain, Streptomyces VITSVK5 spp. (GQ848482). Bioactivity guided extraction yielded a compound DMBPO and its inhibitory activity was tested against selected bacterial and fungal strains. DMBPO showed maximal activity against Escherichia coli with a MIC value of 187mg/ml, followed by Klebsiella pneumoniae (MIC of 220mg/ml and 10.3mm zone of inhibition), Staphylococcus aureus (MIC of >1000mg/ml and 4.4mm zone of inhibition) and Bacillus subtilis (MIC of 850m/ml and 2.6mm zone of inhibition). Furthermore, DMBPO was found to be a potent inhibitor of opportunistic fungal pathogens too. It showed a maximum activity against Aspergillus niger with a MIC value of 1mg/ml and 28mm zone of inhibition. Conclusion. The result of this study indicates that DMBPO possess antibiotic activity to selected bacterial and fungal pathogens and exhibited better activity against fungi than bacteria(AU)


Assuntos
Humanos , Masculino , Feminino , Pirrolidinas/isolamento & purificação , Pirrolidinas/metabolismo , Programas de Rastreamento/métodos , Streptomyces/isolamento & purificação , Produtos Biológicos/isolamento & purificação , Produtos Biológicos/uso terapêutico , Medicina Tradicional/métodos , Medicina Tradicional , Produtos Biológicos/análise , Produtos Biológicos/biossíntese , Produtos Biológicos/farmacocinética , Escherichia coli/isolamento & purificação
5.
Int. microbiol ; 12(1): 13-21, mar. 2009. ilus, tab, graf
Artigo em Inglês | IBECS | ID: ibc-72360

RESUMO

A newly identified extracellular laccase produced by Streptomyces ipomoea CECT 3341 (SilA) was cloned and overexpressed, and its physicochemical characteristics assessed together with its capability to decolorize and detoxify an azotype dye. Molecular analysis of the deduced sequence revealed that SilA contains a TAT-type signal peptide at the N-terminus and only two cupredoxine domains; this is consistent with reports describing two other Streptomyces laccases but contrasts with most laccases, which contain three cupredoxine domains. The heterologous expression and purification of SilA revealed that the homodimer is the only active form of the enzyme. Its stability at high pH and temperature, together with its resistance to high concentrations of NaCl and to typical laccase inhibitors such as sodium azide confirmed the unique properties of this novel laccase. The range of substrates that SilA is able to oxidize was found to be pH-dependent; at alkaline pH, SilA oxidized a wide range of phenolic compounds, including the syringyl and guayacil moieties derived from lignin. The oxidative potential of this enzyme to use phenolic compounds as natural redox mediators was shown through the coordinated action of SilA and acetosyringone (as mediator), which resulted in the complete detoxification of the azo-type dye Orange II (AU)


No disponible


Assuntos
Streptomyces/isolamento & purificação , Corantes/isolamento & purificação , Lacase/análise , Antibacterianos/farmacocinética
6.
Int. microbiol ; 12(1): 23-28, mar. 2009. tab, graf, ilus
Artigo em Inglês | IBECS | ID: ibc-72361

RESUMO

Uptake hydrogenase is an enzyme that is beneficial for nitrogen fixation in bacteria. Recent studies have shown that Frankia sp. has two sets of uptake hydrogenase genes, organized in synton 1 and synton 2. In the present study, phylogenetic analysis of the structural subunits of hydrogenase syntons 1 and 2 showed a distinct clustering pattern between the proteins of Frankia strains that were isolated from different host plants and non-Frankia organisms. The structural subunits of hydrogenase synton 1 of Frankia sp. CpI1, Frankia alni ACN14a, and F. alni AvCI1 were grouped together while those of Frankia spp. CcI3, KB5, UGL140104, and UGL011102 formed another group. The structural subunits of hydrogenase synton 2 of F. alni ACN14a and Frankia spp. CcI3 and BCU110501 grouped together, but those of Frankia spp. KB5 and CpI1, F. alni ArI3, and F. alniAvCI1 comprised a separate group. The structural subunits of hydrogenase syntons 1 and 2 of Frankia sp. EAN1pec were more closely related to those of non-Frankia bacteria, i.e., Streptomyces avermitilis and Anaeromyxobacter sp., respectively, than to those of other Frankia strains, suggesting the occurrence of lateral gene transfer between these organisms. In addition, the accessory Hyp proteins of hydrogenase syntons 1 and 2 of F. alni ACN14a and Frankia sp. CcI3 were shown to be phylogenetically more related to each other than to those of Frankia EAN1pec (AU)


No disponible


Assuntos
Hidrogenase/síntese química , Bactérias/genética , Filogenia , Streptomyces/genética , Myxococcales/genética
7.
Int. microbiol ; 11(2): 133-141, jun. 2008. ilus
Artigo em Inglês | IBECS | ID: ibc-67275

RESUMO

A DNA fragment from the lignocellulolytic actinomycete Streptomyces avermitilis CECT 3339 was cloned using a DNA probe from the xylanase gene xysA of Streptomyces halstedii. The nucleotide sequence analysis revealed two potential ORFs, xyl30 and hd30, encoding a deduced multimodular F/10 xylanase with a binding domain and a secreted glycoxyl hydrolase, respectively. In Streptomyces lividans carrying the subcloned DNA fragment, two xylanase activity bands with estimated molecular masses of 42.8 and 35 kDa (named Xyl30 forms «h» and «l», respectively), were detected by zymograms and SDS-PAGE. The two xylanases had identical N-terminal sequences, suggesting that Xyl30 «l» derived from Xyl30 «h» by C-terminal processing in the culture supernatant. No transcripts of hd30 were detected by RT-PCR. Characterization of the partially purified Xyl30 «h» confirmed the presence of a modular endoxylanase containing a xylan-binding domain, which after processing in the culture supernatant loses the aforementioned domain and thus its capacity to bind xylan (Xyl30 «l»). Xyl30 «h» achieved maximal activity at pH 7.5 and 60 degrees C, retaining more than 50% of its activity from pH 3 to 9 and more than 40% after a 1-h incubation at 70 masculineC. Moreover, in the recombinant host strain up to 400 U xylanase/g medium (dry weight) was produced in solid-state fermentation (SSF) using cereal bran as substrate. The high production yields of this enzyme and its biochemical features make it a good candidate for use in industrial applications (AU)


No disponible


Assuntos
Xilanos/genética , Streptomyces/enzimologia , Fermentação/genética , Análise de Sequência/métodos , Leveduras/enzimologia
8.
Int. microbiol ; 11(1): 25-31, mar. 2008. ilus
Artigo em Inglês | IBECS | ID: ibc-67263

RESUMO

The membrane protein complex translocase mediates the translocation of bacterial proteins. In this complex, the SecY, SecE, and SecG proteins constitute an integral membrane domain. Sequence comparison revealed a potential secG-like gene in the gram-positive soil bacterium Streptomyces lividans. Chromosomal deletion of this gene resulted in a sporulation defect and an overall deficiency in secretion. The SecG-depleted strain was able to overproduce and secrete alpha-amylase, but the appearance of the oversynthesized protein outside the cell was delayed compared to the protein produced by the wildtype strain. SecG deficiency was found to result in more pronounced effects in S. lividans than in Bacillus subtilis or Escherichia coli (AU)


No disponible


Assuntos
Streptomyces/imunologia , Translocação Bacteriana/imunologia , Proteínas de Transporte da Membrana Mitocondrial/imunologia , Bacillus subtilis/imunologia , Escherichia coli/imunologia
9.
Rev. clín. esp. (Ed. impr.) ; 207(1): 21-23, ene. 2007. tab
Artigo em Espanhol | IBECS | ID: ibc-052691

RESUMO

Objetivo. Evaluar el significado clínico del aislamiento de Streptomyces en distintas muestras clínicas. Material y métodos. Se revisaron historias clínicas de los pacientes con aislamiento de Streptomyces en cualquier muestra clínica durante un período de siete años en un hospital terciario. Resultados. Se aisló Streptomyces en 13 pacientes. todos tenían enfermedades subyacentes. Sólo en un paciente Streptomyces fue considerado responsable del cuadro clínico. Se presenta el tercer caso de infección asociada a catéter por este microorganismo. Conclusiones. Streptomyces habitualmente se aísla en pacientes con patología subyacente. Su aislamiento debe interpretarse en el contexto clínico del paciente para considerarlo significativo


OBJECTIVES: To evaluate the clinical significance of Streptomyces isolates in different clinical samples. MATERIAL AND METHODS: Review of the records of all cases of Streptomyces isolated from any clinical sample at a tertiary Hospital, during a seven-year period. RESULTS: Streptomyces was isolated from 13 patients. All of them had underlying diseases. Only in one patient Streptomyces was considered to have a pathogenic role in the clinical picture. We report the third case of catheter-related infection caused by this microorganism. CONCLUSIONS: Streptomyces is usually isolated from patients with underlying diseases. Before considering them significative, Streptomyces isolates must be interpreted in the clinical context


Assuntos
Masculino , Adulto , Humanos , Bacteriemia/etiologia , Cateterismo , Contaminação de Equipamentos , Infecções por Bactérias Gram-Positivas/etiologia , Infecções por Bactérias Gram-Positivas/microbiologia , Streptomyces/crescimento & desenvolvimento , Streptomyces/isolamento & purificação
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