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1.
Immunity ; 44(3): 659-671, 2016 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-26982366

RESUMO

Interleukin-17 (IL-17) and IL-17 receptor (IL-17R) signaling are essential for regulating mucosal host defense against many invading pathogens. Commensal bacteria, especially segmented filamentous bacteria (SFB), are a crucial factor that drives T helper 17 (Th17) cell development in the gastrointestinal tract. In this study, we demonstrate that Th17 cells controlled SFB burden. Disruption of IL-17R signaling in the enteric epithelium resulted in SFB dysbiosis due to reduced expression of α-defensins, Pigr, and Nox1. When subjected to experimental autoimmune encephalomyelitis, IL-17R-signaling-deficient mice demonstrated earlier disease onset and worsened severity that was associated with increased intestinal Csf2 expression and elevated systemic GM-CSF cytokine concentrations. Conditional deletion of IL-17R in the enteric epithelium demonstrated that there was a reciprocal relationship between the gut microbiota and enteric IL-17R signaling that controlled dysbiosis, constrained Th17 cell development, and regulated the susceptibility to autoimmune inflammation.


Assuntos
Encefalomielite Autoimune Experimental/imunologia , Infecções por Bactérias Gram-Positivas/imunologia , Bactérias Gram-Positivas Formadoras de Endosporo/imunologia , Intestinos/fisiologia , Receptores de Interleucina-17/metabolismo , Células Th17/imunologia , Animais , Disbiose/genética , Fator Estimulador de Colônias de Granulócitos e Macrófagos/sangue , Fator Estimulador de Colônias de Granulócitos e Macrófagos/genética , Fator Estimulador de Colônias de Granulócitos e Macrófagos/metabolismo , Interações Hospedeiro-Patógeno , Imunidade nas Mucosas/genética , Interleucina-17/metabolismo , Intestinos/microbiologia , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Microbiota , NADH NADPH Oxirredutases/genética , NADH NADPH Oxirredutases/metabolismo , NADPH Oxidase 1 , Receptores de Superfície Celular/genética , Receptores de Superfície Celular/metabolismo , Receptores de Interleucina-17/genética , Transdução de Sinais/genética , Células Th17/microbiologia , alfa-Defensinas/genética , alfa-Defensinas/metabolismo
2.
J Immunol Methods ; 421: 104-111, 2015 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-25858227

RESUMO

Segmented filamentous bacteria (SFB) are Gram-positive, anaerobic, spore-forming commensals that reside in the gut of many animal species. Described more than forty years ago, SFB have recently gained interest due to their unique ability to modulate the host immune system through induction of IgA and Th17 cells. Here, we describe a collection of methods to detect and quantify SFB and SFB adhesion in intestinal mucosa, as well as SFB-specific CD4 T cells in the lamina propria. In addition, we describe methods for purification of SFB from fecal material of SFB-monoassociated gnotobiotic mice. Using these methods we examine the kinetics of SFB colonization and Th17 cell induction. We also show that SFB colonize unevenly the intestinal mucosa and that SFB adherence occurs predominantly in the terminal ileum and correlates with an increased proportion of SFB-specific Th17 cells.


Assuntos
Infecções por Bactérias Gram-Positivas/imunologia , Bactérias Gram-Positivas Formadoras de Endosporo/imunologia , Mucosa Intestinal/imunologia , Mucosa Intestinal/microbiologia , Células Th17/imunologia , Animais , Aderência Bacteriana/imunologia , Fezes/microbiologia , Camundongos , Camundongos Endogâmicos C57BL , Microbiota/imunologia , Simbiose
3.
Appl Biochem Biotechnol ; 174(8): 2748-61, 2014 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-25227686

RESUMO

The screening for hydrolases-producing, halotolerant, and spore-forming gram-positive bacteria from the root, rhizosphere, and non-rhizosphere soil of Blutaparon portulacoides, a plant found in the Restinga de Jurubatiba located at the northern region of Rio de Janeiro State, Brazil, resulted in the isolation of 22 strains. These strains were identified as Halobacillus blutaparonensis (n = 2), Oceanobacillus picturae (n = 5), and Oceanobacillus iheyensis (n = 15), and all showed the ability to produce different extracellular enzymes. A total of 20 isolates (90.9 %) showed activity for protease, 5 (22.7 %) for phytase, 3 (13.6 %) for cellulase, and 2 (9.1 %) for amylase. Some bacterial strains were capable of producing three (13.6 %) or two (9.1 %) distinct hydrolytic enzymes. However, no bacterial strain with ability to produce esterase and DNase was observed. The isolate designated M9, belonging to the species H. blutaparonensis, was the best producer of protease and also yielded amylase and phytase. This strain was chosen for further studies regarding its protease activity. The M9 strain produced similar amounts of protease when grown either without or with different NaCl concentrations (from 0.5 to 10 %). A simple inspection of the cell-free culture supernatant by gelatin-sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) revealed the presence of three major alkaline proteases of 40, 50, and 70 kDa, which were fully inhibited by phenylmethylsulfonyl fluoride (PMSF) and tosyl-L-phenylalanine chloromethyl ketone (TPCK) (two classical serine protease inhibitors). The secreted proteases were detected in a wide range of temperature (from 4 to 45 °C) and their hydrolytic activities were stimulated by NaCl (up to 10 %). The serine proteases produced by the M9 strain cleaved gelatin, casein, albumin, and hemoglobin, however, in different extensions. Collectively, these results suggest the potential use of the M9 strain in biotechnological and/or industrial processes.


Assuntos
Amaranthaceae/microbiologia , Proteínas de Bactérias/biossíntese , Ecossistema , Bactérias Gram-Positivas Formadoras de Endosporo , Peptídeo Hidrolases/biossíntese , Rizoma/microbiologia , Bactérias Gram-Positivas Formadoras de Endosporo/enzimologia , Bactérias Gram-Positivas Formadoras de Endosporo/genética
4.
FEMS Microbiol Rev ; 38(3): 393-448, 2014 May.
Artigo em Inglês | MEDLINE | ID: mdl-24118059

RESUMO

Thermophilic microorganisms are attractive candidates for conversion of lignocellulose to biofuels because they produce robust, effective, carbohydrate-degrading enzymes and survive under harsh bioprocessing conditions that reflect their natural biotopes. However, no naturally occurring thermophile is known that can convert plant biomass into a liquid biofuel at rates, yields and titers that meet current bioprocessing and economic targets. Meeting those targets requires either metabolically engineering solventogenic thermophiles with additional biomass-deconstruction enzymes or engineering plant biomass degraders to produce a liquid biofuel. Thermostable enzymes from microorganisms isolated from diverse environments can serve as genetic reservoirs for both efforts. Because of the sheer number of enzymes that are required to hydrolyze plant biomass to fermentable oligosaccharides, the latter strategy appears to be the preferred route and thus has received the most attention to date. Thermophilic plant biomass degraders fall into one of two categories: cellulosomal (i.e. multienzyme complexes) and noncellulosomal (i.e. 'free' enzyme systems). Plant-biomass-deconstructing thermophilic bacteria from the genera Clostridium (cellulosomal) and Caldicellulosiruptor (noncellulosomal), which have potential as metabolic engineering platforms for producing biofuels, are compared and contrasted from a systems biology perspective.


Assuntos
Biocombustíveis , Bactérias Gram-Positivas Formadoras de Endosporo/enzimologia , Lignina/metabolismo , Celulossomas/genética , Celulossomas/metabolismo , Bactérias Gram-Positivas Formadoras de Endosporo/classificação , Bactérias Gram-Positivas Formadoras de Endosporo/genética , Temperatura Alta , Dados de Sequência Molecular , Plantas/metabolismo , Microbiologia do Solo
5.
Gene ; 537(1): 85-92, 2014 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-24325907

RESUMO

The human gut microbiota and microbial influences on lipid and glucose metabolism, satiety, and chronic low-grade inflammation are known to be involved in metabolic syndrome. Fermentation end products, especially short chain fatty acids, are believed to engage the epigenetic regulation of inflammatory reactions via FFARs (free fatty acid receptor) and other short chain fatty acid receptors. We studied a potential interaction of the microbiota with epigenetic regulation in obese and type 2 diabetes patients compared to a lean control group over a four month intervention period. Intervention comprised a GLP-1 agonist (glucagon-like peptide 1) for type 2 diabetics and nutritional counseling for both intervention groups. Microbiota was analyzed for abundance, butyryl-CoA:acetate CoA-transferase gene and for diversity by polymerase chain reaction and 454 high-throughput sequencing. Epigenetic methylation of the promoter region of FFAR3 and LINE1 (long interspersed nuclear element 1) was analyzed using bisulfite conversion and pyrosequencing. The diversity of the microbiota as well as the abundance of Faecalibacterium prausnitzii were significantly lower in obese and type 2 diabetic patients compared to lean individuals. Results from Clostridium cluster IV and Clostridium cluster XIVa showed a decreasing trend in type 2 diabetics in comparison to the butyryl-CoA:acetate CoA-transferase gene and according to melt curve analysis. During intervention no significant changes were observed in either intervention group. The analysis of five CpGs in the promoter region of FFAR3 showed a significant lower methylation in obese and type 2 diabetics with an increase in obese patients over the intervention period. These results disclosed a significant correlation between a higher body mass index and lower methylation of FFAR3. LINE-1, a marker of global methylation, indicated no significant differences between the three groups or the time points, although methylation of type 2 diabetics tended to increase over time. Our results provide evidence that a different composition of gut microbiota in obesity and type 2 diabetes affect the epigenetic regulation of genes. Interactions between the microbiota and epigenetic regulation may involve not only short chain fatty acids binding to FFARs. Therefore dietary interventions influencing microbial composition may be considered as an option in the engagement against metabolic syndrome.


Assuntos
Diabetes Mellitus Tipo 2/genética , Epigênese Genética , Ácidos Graxos Voláteis/metabolismo , Trato Gastrointestinal/microbiologia , Obesidade/genética , Receptores Acoplados a Proteínas-G/genética , Adulto , Idoso , Biodiversidade , Índice de Massa Corporal , Estudos de Casos e Controles , Coenzima A-Transferases/genética , Metilação de DNA , Diabetes Mellitus Tipo 2/tratamento farmacológico , Diabetes Mellitus Tipo 2/microbiologia , Fezes/microbiologia , Comportamento Alimentar , Feminino , Peptídeo 1 Semelhante ao Glucagon/agonistas , Peptídeo 1 Semelhante ao Glucagon/análogos & derivados , Peptídeo 1 Semelhante ao Glucagon/uso terapêutico , Bactérias Gram-Positivas/fisiologia , Bactérias Gram-Positivas Formadoras de Endosporo/genética , Humanos , Liraglutida , Elementos Nucleotídeos Longos e Dispersos , Masculino , Microbiota/fisiologia , Pessoa de Meia-Idade , Obesidade/microbiologia , Regiões Promotoras Genéticas
6.
J Agric Food Chem ; 61(47): 11468-76, 2013 Nov 27.
Artigo em Inglês | MEDLINE | ID: mdl-24199681

RESUMO

The rare sugar d-psicose is an ideal sucrose substitute for food products, due to having 70% of the relative sweetness but 0.3% of the energy of sucrose. It also shows important physiological functions. d-Tagatose 3-epimerase (DTEase) family enzymes can produce d-psicose from d-fructose. In this paper, a new member of the DTEase family of enzymes was characterized from Desmospora sp. 8437 (GenBank accession no. WP_009711885 ) and was named Desmospora sp. d-psicose 3-epimerase (DPEase) due to its highest substrate specificity toward d-psicose. Desmospora sp. DPEase was strictly metal-dependent and displayed maximum activity in the presence of Co(2+). The optimum pH and temperature were 7.5 and 60 °C, respectively. The enzyme was relatively thermostable below 50 °C, but easily lost initial activity when preincubated at 60 °C. The thermostability property was almost not affected by the addition of Co(2+). Desmospora sp. DPEase had relatively high catalysis efficiency for the substrates d-psicose and d-fructose, which were measured to be 327 and 116 mM(-1) min(-1), respectively. The equilibrium ratio between d-psicose and d-fructose of Desmospora sp. DPEase was 30:70. The enzyme could produce 142.5 g/L d-psicose from 500 g/L of d-fructose, suggesting that the enzyme is a potential d-psicose producer for industrial production.


Assuntos
Frutose/metabolismo , Bactérias Gram-Positivas Formadoras de Endosporo/enzimologia , Metais/metabolismo , Racemases e Epimerases/genética , Racemases e Epimerases/metabolismo , Clonagem Molecular , Estabilidade Enzimática , Bactérias Gram-Positivas Formadoras de Endosporo/genética , Concentração de Íons de Hidrogênio , Cinética , Filogenia , Temperatura
7.
Environ Microbiol Rep ; 5(6): 911-24, 2013 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-24249300

RESUMO

In this study, we developed and validated a culture-independent method for diversity surveys to specifically detect endospore-forming Firmicutes. The global transcription regulator of sporulation (spo0A) was identified as a gene marker for endospore-forming Firmicutes. To enable phylogenetic classification, we designed a set of primers amplifying a 602 bp fragment of spo0A that we evaluated in pure cultures and environmental samples. The amplification was positive for 35 strains from 11 genera, yet negative for strains from Alicyclobacillus and Sulfobacillus. We also evaluated various DNA extraction methods because endospores often result in reduced yields. Our results demonstrate that procedures utilizing increased physical force improve DNA extraction. An optimized DNA extraction method on biomass pre-extracted from the environmental sample source (indirect DNA extraction) followed by amplification with the aforementioned primers for spo0A was then tested in sediments from two different sources. Specifically, we validated our culture-independent diversity survey methodology on a set of 8338 environmental spo0A sequences obtained from the sediments of Lakes Geneva (Switzerland) and Baikal (Russia). The phylogenetic affiliation of the environmental sequences revealed a substantial number of new clades within endospore-formers. This novel culture-independent approach provides a significant experimental improvement that enables exploration of the diversity of endospore-forming Firmicutes.


Assuntos
Proteínas de Bactérias/genética , Bactérias Gram-Positivas Formadoras de Endosporo/genética , Esporos Bacterianos/genética , Fatores de Transcrição/genética , Sequência de Bases , Biodiversidade , DNA Bacteriano/genética , Genes Bacterianos , Marcadores Genéticos , Bactérias Gram-Positivas Formadoras de Endosporo/classificação , Bactérias Gram-Positivas Formadoras de Endosporo/metabolismo , Dados de Sequência Molecular , Técnicas de Amplificação de Ácido Nucleico , Filogenia , RNA Ribossômico 16S/genética , Alinhamento de Sequência , Análise de Sequência de DNA , Esporos Bacterianos/crescimento & desenvolvimento , Esporos Bacterianos/metabolismo
8.
Appl Environ Microbiol ; 79(17): 5302-12, 2013 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-23811505

RESUMO

Bacterial endospores are highly specialized cellular forms that allow endospore-forming Firmicutes (EFF) to tolerate harsh environmental conditions. EFF are considered ubiquitous in natural environments, in particular, those subjected to stress conditions. In addition to natural habitats, EFF are often the cause of contamination problems in anthropogenic environments, such as industrial production plants or hospitals. It is therefore desirable to assess their prevalence in environmental and industrial fields. To this end, a high-sensitivity detection method is still needed. The aim of this study was to develop and evaluate an approach based on quantitative PCR (qPCR). For this, the suitability of functional genes specific for and common to all EFF were evaluated. Seven genes were considered, but only spo0A was retained to identify conserved regions for qPCR primer design. An approach based on multivariate analysis was developed for primer design. Two primer sets were obtained and evaluated with 16 pure cultures, including representatives of the genera Bacillus, Paenibacillus, Brevibacillus, Geobacillus, Alicyclobacillus, Sulfobacillus, Clostridium, and Desulfotomaculum, as well as with environmental samples. The primer sets developed gave a reliable quantification when tested on laboratory strains, with the exception of Sulfobacillus and Desulfotomaculum. A test using sediment samples with a diverse EFF community also gave a reliable quantification compared to 16S rRNA gene pyrosequencing. A detection limit of about 10(4) cells (or spores) per gram of initial material was calculated, indicating this method has a promising potential for the detection of EFF over a wide range of applications.


Assuntos
Carga Bacteriana/métodos , Proteínas de Bactérias/genética , Bactérias Gram-Positivas Formadoras de Endosporo/genética , Bactérias Gram-Positivas Formadoras de Endosporo/isolamento & purificação , Reação em Cadeia da Polimerase em Tempo Real/métodos , Primers do DNA/genética , Sensibilidade e Especificidade
9.
Prikl Biokhim Mikrobiol ; 48(4): 376-82, 2012.
Artigo em Russo | MEDLINE | ID: mdl-23035569

RESUMO

As a result of sequencing the genome of the termophilic alkali-tolerant lipolytic bacterium Thermosyntropha lipolytica, the gene encoding a lipase secreted into the medium was identified. The recombinant enzyme was expressed in Escherichia coli. It was isolated, purified, and functionally characterized. The lipase exhibited hydrolytic activity toward para-nitrophenyl esters of various chain lengths, as well as triglycerides, including vegetable oils. The optimal reaction conditions were achieved at temperatures from 70 to 80 degrees C and pH 8.0. Enzyme saved more than 80% of its activity in the presence of 10% methanol. This new thermostable lipase may be a promising biocatalyst for organic synthesis; it may find application in the food and detergent industry and biodiesel production.


Assuntos
Proteínas de Bactérias/genética , Genoma Bacteriano , Bactérias Gram-Positivas Formadoras de Endosporo/enzimologia , Lipase/genética , Óleos Vegetais/metabolismo , Álcalis , Sequência de Aminoácidos , Proteínas de Bactérias/isolamento & purificação , Proteínas de Bactérias/metabolismo , Clonagem Molecular , Escherichia coli , Bactérias Gram-Positivas Formadoras de Endosporo/genética , Temperatura Alta , Concentração de Íons de Hidrogênio , Lipase/isolamento & purificação , Lipase/metabolismo , Lipólise , Dados de Sequência Molecular , Nitrofenóis , Proteínas Recombinantes/genética , Proteínas Recombinantes/isolamento & purificação , Proteínas Recombinantes/metabolismo , Triglicerídeos/metabolismo
10.
Extremophiles ; 16(6): 829-39, 2012 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-22956355

RESUMO

The Tinto River (Huelva, Spain) is a natural acidic rock drainage environment produced by the bio-oxidation of metallic sulfides from the Iberian Pyritic Belt. A geomicrobiological model of the different microbial cycles operating in the sediments was recently developed through molecular biological methods, suggesting the presence of iron reducers, methanogens, nitrate reducers and hydrogen producers. In this study, we used a combination of molecular biological methods and targeted enrichment incubations to validate this model and prove the existence of those potential anaerobic activities in the acidic sediments of Tinto River. Methanogenic, sulfate-reducing, denitrifying and hydrogen-producing enrichments were all positive at pH between 5 and 7. Methanogenic enrichments revealed the presence of methanogenic archaea belonging to the genera Methanosarcina and Methanobrevibacter. Enrichments for sulfate-reducing microorganisms were dominated by Desulfotomaculum spp. Denitrifying enrichments showed a broad diversity of bacteria belonging to the genera Paenibacillus, Bacillus, Sedimentibacter, Lysinibacillus, Delftia, Alcaligenes, Clostridium and Desulfitobacterium. Hydrogen-producing enrichments were dominated by Clostridium spp. These enrichments confirm the presence of anaerobic activities in the acidic sediments of the Tinto River that are normally assumed to take place exclusively at neutral pH.


Assuntos
Bactérias/metabolismo , Biodiversidade , Sedimentos Geológicos/microbiologia , Methanobrevibacter/metabolismo , Methanosarcina/metabolismo , Anaerobiose , Bactérias/genética , Bactérias/isolamento & purificação , Técnicas de Tipagem Bacteriana , Sequência de Bases , DNA Arqueal/química , DNA Bacteriano/química , Ecossistema , Sedimentos Geológicos/química , Bactérias Gram-Positivas Formadoras de Endosporo/genética , Bactérias Gram-Positivas Formadoras de Endosporo/isolamento & purificação , Bactérias Gram-Positivas Formadoras de Endosporo/metabolismo , Concentração de Íons de Hidrogênio , Metano/metabolismo , Methanobrevibacter/genética , Methanobrevibacter/isolamento & purificação , Methanosarcina/genética , Methanosarcina/isolamento & purificação , Dados de Sequência Molecular , Nitratos/metabolismo , Filogenia , Espanha , Sulfatos/metabolismo
11.
Pak J Pharm Sci ; 25(4): 715-9, 2012 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-23009985

RESUMO

Valeriana wallichii DC (Valerianaceae) is one of the most widely used traditional remedies for various complications associated with nervous system and digestion. No antimicrobial and anti-inflammatory studies have so far been carried out on the aerial parts of the plant. The present work was focused to evaluate the antimicrobial (antifungal and antibacterial) and anti-inflammatory properties of V. wallichii using reported methods. Chloroform fraction (VW-2) and hexane fraction (VW-3) exhibited significant activity against S. aureus and B. subtilus, respectively. The chloroform fraction (VW-2) showed significant activity against S. aureus with 0.27 mg/ml MIC, where 0.31 mg/ml MIC was deduced for VW-3 fraction against B. subtilus. VW-3 fraction was also found to be the most potent inhibitor of M. canis, showing 70% inhibition with an MIC value of 0.19 mg/ml. Considerable inhibitory activity was also observed for VW-2 and water fraction (VW-6) against M. canis and A. flavus. A remarkable anti-inflammatory like activity was observed for the crude extract at a dose of 200 mg/kg at all observed durations. Other doses of the sample also showed excellent activity. Looking to these results it may be concluded that V. wallichii may be a potential source for activity guided isolation of natural products with antimicrobial and anti-inflammatory-like properties.


Assuntos
Antibacterianos/farmacologia , Anti-Inflamatórios/farmacologia , Antifúngicos/farmacologia , Edema/prevenção & controle , Bactérias Gram-Positivas Formadoras de Endosporo/efeitos dos fármacos , Fungos Mitospóricos/efeitos dos fármacos , Valeriana , Animais , Antibacterianos/química , Antibacterianos/isolamento & purificação , Anti-Inflamatórios/química , Anti-Inflamatórios/isolamento & purificação , Antifúngicos/química , Antifúngicos/isolamento & purificação , Aspergillus flavus/efeitos dos fármacos , Aspergillus flavus/crescimento & desenvolvimento , Bacillus subtilis/efeitos dos fármacos , Bacillus subtilis/crescimento & desenvolvimento , Carragenina , Clorofórmio/química , Modelos Animais de Doenças , Relação Dose-Resposta a Droga , Edema/induzido quimicamente , Bactérias Gram-Positivas Formadoras de Endosporo/crescimento & desenvolvimento , Hexanos/química , Masculino , Testes de Sensibilidade Microbiana , Microsporum/efeitos dos fármacos , Microsporum/crescimento & desenvolvimento , Fungos Mitospóricos/crescimento & desenvolvimento , Folhas de Planta , Ratos , Ratos Wistar , Solventes/química , Staphylococcus aureus/efeitos dos fármacos , Staphylococcus aureus/crescimento & desenvolvimento , Valeriana/química
12.
Genome Res ; 22(6): 1107-19, 2012 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-22434425

RESUMO

Segmented filamentous bacteria (SFB) are host-specific intestinal symbionts that comprise a distinct clade within the Clostridiaceae, designated Candidatus Arthromitus. SFB display a unique life cycle within the host, involving differentiation into multiple cell types. The latter include filaments that attach intimately to intestinal epithelial cells, and from which "holdfasts" and spores develop. SFB induce a multifaceted immune response, leading to host protection from intestinal pathogens. Cultivation resistance has hindered characterization of these enigmatic bacteria. In the present study, we isolated five SFB filaments from a mouse using a microfluidic device equipped with laser tweezers, generated genome sequences from each, and compared these sequences with each other, as well as to recently published SFB genome sequences. Based on the resulting analyses, SFB appear to be dependent on the host for a variety of essential nutrients. SFB have a relatively high abundance of predicted proteins devoted to cell cycle control and to envelope biogenesis, and have a group of SFB-specific autolysins and a dynamin-like protein. Among the five filament genomes, an average of 8.6% of predicted proteins were novel, including a family of secreted SFB-specific proteins. Four ADP-ribosyltransferase (ADPRT) sequence types, and a myosin-cross-reactive antigen (MCRA) protein were discovered; we hypothesize that they are involved in modulation of host responses. The presence of polymorphisms among mouse SFB genomes suggests the evolution of distinct SFB lineages. Overall, our results reveal several aspects of SFB adaptation to the mammalian intestinal tract.


Assuntos
Proteínas de Bactérias/genética , Genoma Bacteriano , Bactérias Gram-Positivas Formadoras de Endosporo/fisiologia , Intestinos/microbiologia , Análise de Célula Única/métodos , ADP Ribose Transferases/genética , ADP Ribose Transferases/metabolismo , Adaptação Fisiológica , Sequência de Aminoácidos , Animais , Proteínas de Bactérias/metabolismo , Diferenciação Celular/genética , DNA Ribossômico , Células Epiteliais/microbiologia , Bactérias Gram-Positivas Formadoras de Endosporo/genética , Camundongos , Técnicas Analíticas Microfluídicas , Dados de Sequência Molecular , Filogenia , Polimorfismo Genético , Análise de Sequência de DNA
13.
Anaerobe ; 18(1): 172-3, 2012 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-22155447

RESUMO

Robinsoniella peoriensis is a recently described anaerobic, spore-forming, Gram positive bacillus originally recovered from swine-manure and clinical human samples. In this study, R. peoriensis was isolated from the feces of one set of twin premature neonates. It suggests that this anaerobic bacillus may be a commensal bacterium of human gut.


Assuntos
Fezes/microbiologia , Bactérias Gram-Positivas Formadoras de Endosporo/isolamento & purificação , Antibacterianos/farmacologia , Técnicas de Tipagem Bacteriana , Feminino , Bactérias Gram-Positivas Formadoras de Endosporo/classificação , Humanos , Recém-Nascido , Recém-Nascido Prematuro , Testes de Sensibilidade Microbiana , RNA Ribossômico 16S
14.
Extremophiles ; 15(5): 565-71, 2011 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-21761211

RESUMO

An anaerobic, halophilic, and fermentative bacterium, strain S200(T), was isolated from a core sample of a deep hypersaline oil reservoir. Cells were rod-shaped, non-motile, and stained Gram-positive. It grew at NaCl concentrations ranging from 6 to 26% (w/v), with optimal growth at 15% (w/v) NaCl, and at temperatures between 25 and 47°C with an optimum at 40-45°C. The optimum pH was 7.3 (range 6.2-8.8; no growth at pH 5.8 and pH 9). The doubling time in optimized growth conditions was 3.5 h. Strain S200(T) used exclusively carbohydrates as carbon and energy sources. The end products of glucose degradation were lactate, formate, ethanol, acetate, H(2), and CO(2). The predominant cellular fatty acids were non-branched fatty acids C(16:1), C(16:0), and C(14:0). The G + C mole% of the DNA was 32.7%. Phylogenetic analysis based on the 16S rRNA gene sequence revealed that strain S200(T) formed a distinct lineage within the family Halobacteroidaceae, order Halanaerobiales, and was most closely related to Halanaerobaculum tunisiense DSM 19997(T) and Halobacteroides halobius DSM 5150(T), with sequence similarity of 92.3 and 91.9%, respectively. On the basis of its physiological and genotypic properties, strain S200(T) is proposed to be assigned to a novel species of a novel genus, for which the name Halanaerocella petrolearia is proposed. The type strain of Halanaerocella petrolearia is strain S200(T) (=DSM 22693(T) = JCM 16358(T)).


Assuntos
Metabolismo dos Carboidratos/fisiologia , Bactérias Gram-Positivas Formadoras de Endosporo/genética , Bactérias Gram-Positivas Formadoras de Endosporo/metabolismo , Filogenia , Anaerobiose/fisiologia , Sequência de Bases , Genótipo , Bactérias Gram-Positivas Formadoras de Endosporo/citologia , Bactérias Gram-Positivas Formadoras de Endosporo/isolamento & purificação , Concentração de Íons de Hidrogênio , Dados de Sequência Molecular , Salinidade
15.
PLoS One ; 6(2): e17049, 2011 Feb 25.
Artigo em Inglês | MEDLINE | ID: mdl-21364875

RESUMO

In the NOD mouse, the incidence of type-1 diabetes is thought to be influenced by the degree of cleanliness of the mouse colony. Studies collectively demonstrate that exposure to bacterial antigen or infection in the neonatal period prevents diabetes [1], [2], [3], [4], [5], [6], [7], [8], [9], [10], supporting the notion that immunostimulation can benefit the maturation of the postnatal immune system [11]. A widely accepted extrapolation from this data has been the notion that NOD mice maintained under germ-free conditions have an increased incidence of diabetes. However, evidence supporting this influential concept is surprisingly limited [12]. In this study, we demonstrate that the incidence of diabetes in female NOD mice remained unchanged under germ-free conditions. By contrast, a spontaneous monoculture with a gram-positive aerobic spore-forming rod delayed the onset and reduced the incidence of diabetes. These findings challenge the view that germ-free NOD mice have increased diabetes incidence and demonstrate that modulation of intestinal microbiota can prevent the development of type-1 diabetes.


Assuntos
Diabetes Mellitus Tipo 1/epidemiologia , Diabetes Mellitus Tipo 1/etiologia , Vida Livre de Germes , Camundongos Endogâmicos NOD/microbiologia , Animais , Animais Recém-Nascidos , Diabetes Mellitus Tipo 1/imunologia , Diabetes Mellitus Tipo 1/microbiologia , Feminino , Bactérias Gram-Positivas Formadoras de Endosporo/fisiologia , Incidência , Intestinos/microbiologia , Intestinos/patologia , Metagenoma/imunologia , Metagenoma/fisiologia , Camundongos
16.
Trends Microbiol ; 19(2): 85-94, 2011 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-21112786

RESUMO

Under conditions that are not conducive to growth, such as nutrient depletion, many members of the orders Bacillales and Clostridiales can sporulate, generating dormant and resistant spores that can survive in the absence of nutrients for years under harsh conditions. However, when nutrients are again present, these spores can return to active growth through the process of germination. Many of the components of the spore germination machinery are conserved between spore forming members of the Bacillales and Clostridiales orders. However, recent studies have revealed significant differences between the germination of spores of Clostridium perfringens and that of spores of a number of Bacillus species, both in the proteins and in the signal transduction pathways involved. In this review, the roles of components of the spore germination machinery of C. perfringens and several Bacillus species and the bioinformatic analysis of germination proteins in the Bacillales and Clostridiales orders are discussed and models for the germination of spores of these two orders are proposed.


Assuntos
Bacillales/fisiologia , Proteínas de Bactérias/metabolismo , Bactérias Gram-Positivas Formadoras de Endosporo/fisiologia , Esporos Bacterianos/crescimento & desenvolvimento , Transdução de Sinais
17.
Anaerobe ; 16(5): 543-6, 2010 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-20674754

RESUMO

Segmented filamentous bacteria (SFB) colonize in the ileum. They promote the development of intraepithelial lymphocytes and immunoglobulin A (IgA)-producing cells in the small intestine. In SFB-monoassociated mice, changes in SFB colonization of the small intestine were related to the level of IgA derived from maternal milk during the suckling period and self-produced in the small intestine after weaning. In this study, we investigated whether or not maternal and neonatal IgA influence the colonization of SFB in conventional mice from 18 to 105 days old. The pups were forcedly weaned at 20 days old. SFB could be detected in the distal small intestine after day 22, and their number rapidly reached a maximum on day 28. Thereafter, they gradually declined to one-fourth of the maximum level. The lowest concentrations of IgA in the small intestinal and cecal contents were detected on day 22. Thereafter, they increased as the age of the mice increased. The expression of the polymeric immunoglobulin receptor gene in the distal small intestine increased after weaning. These results suggested that the colonization of SFB in the pre-weaning and post-weaning periods might be prevented with IgA derived from maternal milk and self-produced IgA, respectively.


Assuntos
Bactérias Gram-Positivas Formadoras de Endosporo/imunologia , Imunidade Materno-Adquirida , Imunoglobulina A/metabolismo , Intestino Delgado/microbiologia , Animais , Feminino , Bactérias Gram-Positivas Formadoras de Endosporo/crescimento & desenvolvimento , Intestino Delgado/imunologia , Masculino , Camundongos , Camundongos Endogâmicos BALB C
19.
Curr Microbiol ; 61(6): 525-33, 2010 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-20397018

RESUMO

Thermophilic bacteria that form highly heat-resistant spores constitute an important group of spoilage bacteria of low-acid canned food. A PCR assay was developed in order to rapidly trace these bacteria. Three PCR primer pairs were designed from rRNA gene sequences. These primers were evaluated for the specificity and the sensitivity of detection. Two primer pairs allowed detection at the species level of Geobacillus stearothermophilus and Moorella thermoacetica/thermoautrophica. The other pair allowed group-specific detection of anaerobic thermophilic bacteria of the genera Thermoanaerobacterium, Thermoanaerobacter, Caldanerobium and Caldanaerobacter. After a single enrichment step, these PCR assays allowed the detection of 28 thermophiles from 34 cans of spoiled low-acid food. In addition, 13 ingredients were screened for the presence of these bacteria. This PCR assay serves as a detection method for strains able to spoil low-acid canned food treated at 55°C. It will lead to better reactivity in the canning industry. Raw materials and ingredients might be qualified not only for quantitative spore contamination, but also for qualitative contamination by highly heat-resistant spores.


Assuntos
Técnicas Bacteriológicas/métodos , Alimentos em Conserva/microbiologia , Bactérias Gram-Positivas Formadoras de Endosporo/genética , Bactérias Gram-Positivas Formadoras de Endosporo/isolamento & purificação , Reação em Cadeia da Polimerase/métodos , Primers do DNA/genética , DNA Bacteriano/genética , DNA Ribossômico/genética , Conservação de Alimentos/métodos , Genes de RNAr , Bactérias Gram-Positivas Formadoras de Endosporo/classificação , Temperatura Alta , Sensibilidade e Especificidade
20.
Int J Syst Evol Microbiol ; 60(Pt 6): 1383-6, 2010 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-19671721

RESUMO

A Gram-stain-positive, halotolerant, neutrophilic, rod-shaped bacterium, strain MF38(T), was isolated from a saline-alkaline soil in China and subjected to a polyphasic taxonomic characterization. The isolate grew in the presence of 0-15 % (w/v) NaCl and at pH 6.5-8.5; optimum growth was observed with 3.0 % (w/v) NaCl and at pH 7.0. Chemotaxonomic analysis showed menaquinone MK-7 as the predominant respiratory quinone and anteiso-C(15 : 0), anteiso-C(17 : 0), iso-C(15 : 0), C(17 : 0) and C(16 : 0) as major fatty acids. The genomic DNA G+C content was 35.3 mol%. 16S rRNA gene sequence similarities of strain MF38(T) with type strains of described Gracilibacillus species ranged from 95.3 to 97.7 %. Strain MF38(T) exhibited the closest phylogenetic affinity to the type strain of Gracilibacillus dipsosauri, with 97.7 % 16S rRNA gene sequence similarity. The DNA-DNA reassociation between strain MF38(T) and G. dipsosauri DSM 11125(T) was 45 %. On the basis of phenotypic and genotypic data, strain MF38(T) represents a novel species of the genus Gracilibacillus, for which the name Gracilibacillus ureilyticus sp. nov. (type strain MF38(T) =CGMCC 1.7727(T) =JCM 15711(T)) is proposed.


Assuntos
Bactérias Gram-Positivas Formadoras de Endosporo/isolamento & purificação , Filogenia , Microbiologia do Solo , Composição de Bases , DNA Bacteriano/genética , Bactérias Gram-Positivas Formadoras de Endosporo/classificação , Bactérias Gram-Positivas Formadoras de Endosporo/genética , Bactérias Gram-Positivas Formadoras de Endosporo/crescimento & desenvolvimento , Dados de Sequência Molecular , RNA Bacteriano/genética , RNA Ribossômico 16S/genética , Esporos Bacterianos/classificação , Esporos Bacterianos/genética
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