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1.
Int J Syst Evol Microbiol ; 70(5): 2988-2997, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-32369000

RESUMO

A novel, Gram-stain-positive, rod-shaped, non-motile, non-spore-forming, obligately anaerobic bacterium, designated strain ZHW00191T, was isolated from human faeces and characterized by using a polyphasic taxonomic approach. Growth occurred at 25-45 °C (optimum, 37-42 °C), at pH 5.5-10.0 (optimum, pH 6.5-7.0) and with 0-2 % (w/v) NaCl (optimum, 0 %). The end products of glucose fermentation were acetic acid, isobutyric acid and isovaleric acid and a small amount of propionic acid. The dominant cellular fatty acids (>10 %) of strain ZHW00191T were C16 : 0, C18 : 1 ω9с and C18 : 2ω6,9с. Its polar lipid profile comprised diphosphatidylglycerol, phosphatidylglycerol, three unidentified phospholipids and ten unidentified glycolipids. Respiratory quinones were not detected. The cell-wall peptidoglycan contained meso-2,6-diaminopimelic acid, and the whole-cell sugars were ribose and glucose. The genomic DNA G+C content was 32.8 mol%. Analysis of the 16S rRNA gene sequence indicated that ZHW00191T was most closely related to Clostridium hiranonis TO-931T (95.3 % similarity). Average nucleotide identity (ANI) and digital DNA-DNA hybridization (dDDH) analyses with closely related reference strains indicated that reassociation values were both well below the thresholds of 95-96% and 70 % for species delineation, respectively. Based on phenotypic, chemotaxonomic and genetic studies, a novel genus, Peptacetobacter gen. nov., is proposed. The novel isolate ZHW00191T (=JCM 33482T=GDMCC 1.1530T) is proposed as the type strain of the type species Peptacetobacter hominis gen. nov., sp. nov. of the proposed new genus. Furthermore, it is proposed that Clostridium hiranonis be transferred to this novel genus, as Peptacetobacter hiranonis comb. nov.


Assuntos
Clostridium/classificação , Fezes/microbiologia , Bacilos Gram-Positivos Formadores de Endosporo/classificação , Filogenia , Adulto , Técnicas de Tipagem Bacteriana , Composição de Bases , China , DNA Bacteriano/genética , Ácido Diaminopimélico/química , Ácidos Graxos/química , Glicolipídeos/química , Bacilos Gram-Positivos Formadores de Endosporo/isolamento & purificação , Humanos , Masculino , Hibridização de Ácido Nucleico , Peptidoglicano/química , Fosfolipídeos/química , RNA Ribossômico 16S/genética , Análise de Sequência de DNA
2.
Nat Commun ; 11(1): 468, 2020 01 24.
Artigo em Inglês | MEDLINE | ID: mdl-31980603

RESUMO

Bone loss is a frequent but not universal complication of hyperparathyroidism. Using antibiotic-treated or germ-free mice, we show that parathyroid hormone (PTH) only caused bone loss in mice whose microbiota was enriched by the Th17 cell-inducing taxa segmented filamentous bacteria (SFB). SFB+ microbiota enabled PTH to expand intestinal TNF+ T and Th17 cells and increase their S1P-receptor-1 mediated egress from the intestine and recruitment to the bone marrow (BM) that causes bone loss. CXCR3-mediated TNF+ T cell homing to the BM upregulated the Th17 chemoattractant CCL20, which recruited Th17 cells to the BM. This study reveals mechanisms for microbiota-mediated gut-bone crosstalk in mice models of hyperparathyroidism that may help predict its clinical course. Targeting the gut microbiota or T cell migration may represent therapeutic strategies for hyperparathyroidism.


Assuntos
Microbioma Gastrointestinal/imunologia , Osteoporose/etiologia , Hormônio Paratireóideo/imunologia , Subpopulações de Linfócitos T/imunologia , Células Th17/imunologia , Animais , Transplante de Microbiota Fecal , Feminino , Vida Livre de Germes , Bacilos Gram-Positivos Formadores de Endosporo/imunologia , Hiperparatireoidismo Primário/complicações , Hiperparatireoidismo Primário/imunologia , Hiperparatireoidismo Primário/microbiologia , Intestinos/imunologia , Intestinos/microbiologia , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Osteoporose/imunologia , Osteoporose/microbiologia , Fator de Necrose Tumoral alfa/imunologia
3.
Infect Control Hosp Epidemiol ; 40(1): 47-52, 2019 01.
Artigo em Inglês | MEDLINE | ID: mdl-30426908

RESUMO

OBJECTIVE: Hospital environmental surfaces are frequently contaminated by microorganisms. However, the causal mechanism of bacterial contamination of the environment as a source of transmission is still debated. This prospective study was performed to characterize the nature of multidrug-resistant organism (MDRO) transmission between the environment and patients using standard microbiological and molecular techniques. SETTING: Prospective cohort study at 2 academic medical centers. DESIGN: A prospective multicenter study to characterize the nature of bacterial transfer events between patients and environmental surfaces in rooms that previously housed patients with 1 of 4 'marker' MDROs: methicillin-resistant Staphylococcus aureus, vancomycin-resistant enterococci, Clostridium difficile, and MDR Acinetobacter baumannii. Environmental and patient microbiological samples were obtained on admission into a freshly disinfected inpatient room. Repeat samples from room surfaces and patients were taken on days 3 and 7 and each week the patient stayed in the same room. The bacterial identity, antibiotic susceptibility, and molecular sequences were compared between organisms found in the environment samples and patient sources. RESULTS: We enrolled 80 patient-room admissions; 9 of these patients (11.3%) were asymptomatically colonized with MDROs at study entry. Hospital room surfaces were contaminated with MDROs despite terminal disinfection in 44 cases (55%). Microbiological Bacterial Transfer events either to the patient, the environment, or both occurred in 12 patient encounters (18.5%) from the microbiologically evaluable cohort. CONCLUSIONS: Microbiological Bacterial Transfer events between patients and the environment were observed in 18.5% of patient encounters and occurred early in the admission. This study suggests that research on prevention methods beyond the standard practice of room disinfection at the end of a patient's stay is needed to better prevent acquisition of MDROs through the environment.


Assuntos
Infecção Hospitalar/microbiologia , Desinfecção , Farmacorresistência Bacteriana Múltipla , Contaminação de Equipamentos , Bacilos Gram-Negativos Anaeróbios Facultativos/isolamento & purificação , Bacilos Gram-Positivos Formadores de Endosporo/isolamento & purificação , Idoso , Equipamentos e Provisões Hospitalares , Feminino , Instalações de Saúde , Humanos , Masculino , Pessoa de Meia-Idade , North Carolina , Quartos de Pacientes , Estudos Prospectivos
4.
J Proteomics ; 154: 1-12, 2017 02 10.
Artigo em Inglês | MEDLINE | ID: mdl-27939684

RESUMO

Using the combination of affinity enrichment and high-resolution LC-MS/MS analysis, we performed a large-scale lysine malonylation analysis in the model representative of Gram-positive plant growth-promoting rhizobacteria (PGPR), Bacillus amyloliquefaciens FZB42. Altogether, 809 malonyllysine sites in 382 proteins were identified. The bioinformatic analysis revealed that lysine malonylation occurs on the proteins involved in a variety of biological functions including central carbon metabolism, fatty acid biosynthesis and metabolism, NAD(P) binding and translation machinery. A group of proteins known to be implicated in rhizobacterium-plant interaction were also malonylated; especially, the enzymes responsible for antibiotic production including polyketide synthases (PKSs) and nonribosomal peptide synthases (NRPSs) were highly malonylated. Furthermore, our analysis showed malonylation occurred on proteins structure with higher surface accessibility and appeared to be conserved in many bacteria but not in archaea. The results provide us valuable insights into the potential roles of lysine malonylation in governing bacterial metabolism and cellular processes. BIOLOGICAL SIGNIFICANCE: Although in mammalian cells some important findings have been discovered that protein malonylation is related to basic metabolism and chronic disease, few studies have been performed on prokaryotic malonylome. In this study, we determined the malonylation profiles of Bacillus amyloliquefaciens FZB42, a model organism of Gram-positive plant growth-promoting rhizobacteria. FZB42 is known for the extensive investigations on its strong ability of producing antimicrobial polyketides and its potent activities of stimulating plant growth. Our analysis shows that malonylation is highly related to the polyketide synthases and the proteins involved bacterial interactions with plants. The results not only provide one of the first malonylomes for exploring the biochemical nature of bacterial proteins, but also shed light on the better understanding of bacterial antibiotic biosynthesis and plant-microbe interaction.


Assuntos
Bacillus amyloliquefaciens/química , Proteínas de Bactérias/metabolismo , Malonatos/metabolismo , Plantas/microbiologia , Policetídeos/metabolismo , Bacillus amyloliquefaciens/metabolismo , Bactérias/citologia , Bactérias/metabolismo , Biologia Computacional , Bacilos Gram-Positivos Formadores de Endosporo , Lisina/metabolismo , Plantas/metabolismo
5.
Infect Control Hosp Epidemiol ; 37(12): 1426-1432, 2016 12.
Artigo em Inglês | MEDLINE | ID: mdl-27619507

RESUMO

OBJECTIVE To determine the typical microbial bioburden (overall bacterial and multidrug-resistant organisms [MDROs]) on high-touch healthcare environmental surfaces after routine or terminal cleaning. DESIGN Prospective 2.5-year microbiological survey of large surface areas (>1,000 cm2). SETTING MDRO contact-precaution rooms from 9 acute-care hospitals and 2 long-term care facilities in 4 states. PARTICIPANTS Samples from 166 rooms (113 routine cleaned and 53 terminal cleaned rooms). METHODS Using a standard sponge-wipe sampling protocol, 2 composite samples were collected from each room; a third sample was collected from each Clostridium difficile room. Composite 1 included the TV remote, telephone, call button, and bed rails. Composite 2 included the room door handle, IV pole, and overbed table. Composite 3 included toileting surfaces. Total bacteria and MDROs (ie, methicillin-resistant Staphylococcus aureus, vancomycin-resistant enterococci [VRE], Acinetobacter baumannii, Klebsiella pneumoniae, and C. difficile) were quantified, confirmed, and tested for drug resistance. RESULTS The mean microbial bioburden and range from routine cleaned room composites were higher (2,700 colony-forming units [CFU]/100 cm2; ≤1-130,000 CFU/100 cm2) than from terminal cleaned room composites (353 CFU/100 cm2; ≤1-4,300 CFU/100 cm2). MDROs were recovered from 34% of routine cleaned room composites (range ≤1-13,000 CFU/100 cm2) and 17% of terminal cleaned room composites (≤1-524 CFU/100 cm2). MDROs were recovered from 40% of rooms; VRE was the most common (19%). CONCLUSIONS This multicenter bioburden summary provides a first step to determining microbial bioburden on healthcare surfaces, which may help provide a basis for developing standards to evaluate cleaning and disinfection as well as a framework for studies using an evidentiary hierarchy for environmental infection control. Infect Control Hosp Epidemiol 2016;1426-1432.


Assuntos
Infecção Hospitalar/microbiologia , Contaminação de Equipamentos , Bacilos Gram-Negativos Anaeróbios Facultativos/isolamento & purificação , Bacilos Gram-Positivos Formadores de Endosporo/isolamento & purificação , Desinfetantes/administração & dosagem , Farmacorresistência Bacteriana Múltipla , Equipamentos e Provisões Hospitalares , Instalações de Saúde , Humanos , Quartos de Pacientes , Estudos Prospectivos
6.
Med Chem ; 12(6): 544-52, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-26825066

RESUMO

BACKGROUND: The frequent use of antibacterial agents and the exposure of the patients to lifesaving intervention processes are consistently associated with the increased chance of nosocomial infections and the emergence of multidrug resistant microorganisms in the hospital environment. Thus, new antimicrobial agents are of unmet need to treat the severe nosocomial infections caused by these putative pathogens resistant to currently available agents. METHOD: Design, synthesis, and biological evaluation of analogues of nitazoxanide (NTZ), an FDA approved thiazolide antiparasitic, as new antimicrobial agents against nosocomial pathogens were described. The NTZ analogues were rationally explored on the basis of either increasing the electronic resonance effects at the nitrothiazolide moiety or improving the anionic form of the whole NTZ structure. RESULTS: The MICs and MBCs values of these NTZ analogues against prevalent nosocomial pathogens were measured. The benzologous analogues 3a and 4a and p-chlorobenzenesulfonamides 8d and 9d exhibited tremendous antimicrobial activities, which were 100- to 2000-fold more potent than NTZ and ciprofloxacin. CONCLUSION: The results demonstrated that delicate manipulation of the NTZ core structure could lead to promising antimicrobial agents against the nosocomial pathogens.


Assuntos
Antibacterianos/farmacologia , Tiazóis/farmacologia , Antibacterianos/síntese química , Ciprofloxacino/farmacologia , Infecção Hospitalar/microbiologia , Bactérias Gram-Negativas/efeitos dos fármacos , Bacilos Gram-Positivos Formadores de Endosporo/efeitos dos fármacos , Testes de Sensibilidade Microbiana , Ftalimidas/síntese química , Ftalimidas/farmacologia , Relação Estrutura-Atividade , Sulfonamidas/síntese química , Sulfonamidas/farmacologia , Tiazóis/síntese química
9.
PLoS One ; 10(3): e0119508, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25799047

RESUMO

Members of the bacterial genus Caldicellulosiruptor are the most thermophilic cellulolytic microbes described with ability to digest lignocellulosic biomass without conventional pretreatment. The cellulolytic ability of different species varies dramatically and correlates with the presence of the multimodular cellulase CelA, which contains both a glycoside hydrolase family 9 endoglucanase and a glycoside hydrolase family 48 exoglucanase known to be synergistic in their activity, connected by three cellulose-binding domains via linker peptides. This architecture exploits the cellulose surface ablation driven by its general cellulase processivity as well as excavates cavities into the surface of the substrate, revealing a novel paradigm for cellulase activity. We recently reported that a deletion of celA in C. bescii had a significant effect on its ability to utilize complex biomass. To analyze the structure and function of CelA and its role in biomass deconstruction, we constructed a new expression vector for C. bescii and were able, for the first time, to express significant quantities of full-length protein in vivo in the native host. The protein, which contains a Histidine tag, was active and excreted from the cell. Expression of CelA protein with and without its signal sequence allowed comparison of protein retained intracellularly to protein transported extracellularly. Analysis of protein in culture supernatants revealed that the extracellular CelA protein is glycosylated whereas the intracellular CelA is not, suggesting that either protein transport is required for this post-translational modification or that glycosylation is required for protein export. The mechanism and role of protein glycosylation in bacteria is poorly understood and the ability to express CelA in vivo in C. bescii will allow the study of the mechanism of protein glycosylation in this thermophile. It will also allow the study of glycosylation of CelA itself and its role in the structure and function of this important enzyme in biomass deconstruction.


Assuntos
Proteínas de Bactérias/metabolismo , Celulase/metabolismo , Celulose/metabolismo , Bacilos Gram-Positivos Formadores de Endosporo/enzimologia , Proteínas de Bactérias/genética , Proteínas de Bactérias/isolamento & purificação , Biomassa , Celulase/genética , Celulase/isolamento & purificação , Glicosídeo Hidrolases/metabolismo , Glicosilação , Hidrólise , Processamento de Proteína Pós-Traducional
10.
Mem Inst Oswaldo Cruz ; 110(1): 65-74, 2015 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-25742265

RESUMO

Aiming to identify new sources of bioactive secondary metabolites, we isolated 82 endophytic fungi from stems and barks of the native Brazilian tree Caesalpinia echinata Lam. (Fabaceae). We tested their ethyl acetate extracts in several in vitro assays. The organic extracts from three isolates showed antibacterial activity against Staphylococcus aureus and Escherichia coli [minimal inhibitory concentration (MIC) 32-64 µg/mL]. One isolate inhibited the growth of Salmonella typhimurium (MIC 64 µg/mL) and two isolates inhibited the growth of Klebsiella oxytoca (MIC 64 µg/mL), Candida albicans and Candida tropicalis (MIC 64-128 µg/mL). Fourteen extracts at a concentration of 20 µg/mL showed antitumour activities against human breast cancer and human renal cancer cells, while two isolates showed anti-tumour activities against human melanoma cancer cells. Six extracts were able to reduce the proliferation of human peripheral blood mononuclear cells, indicating some degree of selective toxicity. Four isolates were able to inhibit Leishmania (Leishmania) amazonensis and one isolate inhibited Trypanosoma cruzi by at least 40% at 20 µg/mL. The trypanocidal extract obtained from Fusarium sp. [KF611679] culture was subjected to bioguided fractionation, which revealed beauvericin as the compound responsible for the observed toxicity of Fusarium sp. to T. cruzi. This depsipeptide showed a half maximal inhibitory concentration of 1.9 µg/mL (2.43 µM) in a T. cruzi cellular culture assay.


Assuntos
Caesalpinia/microbiologia , Depsipeptídeos/farmacologia , Endófitos/isolamento & purificação , Fusarium/isolamento & purificação , Tripanossomicidas/farmacologia , Trypanosoma cruzi/efeitos dos fármacos , Anti-Infecciosos/isolamento & purificação , Anti-Infecciosos/farmacologia , Candida albicans/efeitos dos fármacos , Linhagem Celular Tumoral/efeitos dos fármacos , Fracionamento Químico , Misturas Complexas , Primers do DNA , Depsipeptídeos/isolamento & purificação , Endófitos/classificação , Enterobacteriaceae/efeitos dos fármacos , Fusarium/metabolismo , Bacilos Gram-Positivos Formadores de Endosporo/efeitos dos fármacos , Humanos , Leishmania/efeitos dos fármacos , Leucócitos Mononucleares/efeitos dos fármacos , Testes de Sensibilidade Microbiana , Pseudomonas aeruginosa/efeitos dos fármacos , Tripanossomicidas/isolamento & purificação
11.
Int J Syst Evol Microbiol ; 65(Pt 4): 1193-8, 2015 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-25609678

RESUMO

A Gram-stain-positive, spore-forming, obligately anaerobic bacterium, designated LAM201(T), was isolated from sediment samples from an alkaline-saline lake located in Daqing oilfield, Daqing City, PR China. Cells of strain LAM201(T) were non-motile and straight or spiral rod-shapes. Strain LAM201(T) was able to utilize glucose, fructose, maltose, trehalose and sorbitol as the sole carbon source. Acetic acid, ethanol, iso-butanoic acid and iso-valeric acid were the main products of glucose fermentation. The major fatty acids of LAM201(T) were C(16 : 0) (26.7%) and C(18 : 0) (11.2%). The main polar lipids were four unknown glycolipids and five unknown phospholipids. The predominant cell-wall sugars were ribose and galactose. The cell-wall peptidoglycan of strain LAM201(T) contained alanine, glycine, glutamic acid and aspartic acid. Sodium sulfite was used as the electron acceptor. The G+C content of the genomic DNA was 32±0.8 mol%, as determined by the T(m) method. Analysis of the 16S rRNA gene sequence indicated that the isolate belonged to the genus Romboutsia and was most closely related to Romboutsia lituseburensis DSM 797(T) and Romboutsia ilealis CRIB(T) with 97.3% and 97.2% similarities, respectively. The DNA-DNA hybridization values between strain LAM201(T) and the two reference strains were 37% and 31%, respectively. On the basis of its phenotypic, phylogenetic and chemotaxonomic characteristics, strain LAM201(T) is suggested to represent a novel species within the genus Romboutsia , for which the name Romboutsia sedimentorum sp. nov. is proposed. The type strain is LAM201(T) ( = ACCC 00717(T) = JCM 19607(T)).


Assuntos
Bacilos Gram-Positivos Formadores de Endosporo/classificação , Lagos/microbiologia , Filogenia , Bactérias Anaeróbias/classificação , Bactérias Anaeróbias/genética , Bactérias Anaeróbias/isolamento & purificação , Técnicas de Tipagem Bacteriana , Composição de Bases , China , DNA Bacteriano/genética , Ácidos Graxos/química , Sedimentos Geológicos/microbiologia , Glicolipídeos/química , Bacilos Gram-Positivos Formadores de Endosporo/genética , Bacilos Gram-Positivos Formadores de Endosporo/isolamento & purificação , Dados de Sequência Molecular , Hibridização de Ácido Nucleico , Peptidoglicano/química , Fosfolipídeos/química , RNA Ribossômico 16S/genética , Salinidade , Análise de Sequência de DNA
12.
BMC Genomics ; 15: 1107, 2014 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-25511286

RESUMO

BACKGROUND: Bacteria of the genus Sulfobacillus are found worldwide as members of microbial communities that accelerate sulfide mineral dissolution in acid mine drainage environments (AMD), acid-rock drainage environments (ARD), as well as in industrial bioleaching operations. Despite their frequent identification in these environments, their role in biogeochemical cycling is poorly understood. RESULTS: Here we report draft genomes of five species of the Sulfobacillus genus (AMDSBA1-5) reconstructed by cultivation-independent sequencing of biofilms sampled from the Richmond Mine (Iron Mountain, CA). Three of these species (AMDSBA2, AMDSBA3, and AMDSBA4) have no cultured representatives while AMDSBA1 is a strain of S. benefaciens, and AMDSBA5 a strain of S. thermosulfidooxidans. We analyzed the diversity of energy conservation and central carbon metabolisms for these genomes and previously published Sulfobacillus genomes. Pathways of sulfur oxidation vary considerably across the genus, including the number and type of subunits of putative heterodisulfide reductase complexes likely involved in sulfur oxidation. The number and type of nickel-iron hydrogenase proteins varied across the genus, as does the presence of different central carbon pathways. Only the AMDSBA3 genome encodes a dissimilatory nitrate reducatase and only the AMDSBA5 and S. thermosulfidooxidans genomes encode assimilatory nitrate reductases. Within the genus, AMDSBA4 is unusual in that its electron transport chain includes a cytochrome bc type complex, a unique cytochrome c oxidase, and two distinct succinate dehydrogenase complexes. CONCLUSIONS: Overall, the results significantly expand our understanding of carbon, sulfur, nitrogen, and hydrogen metabolism within the Sulfobacillus genus.


Assuntos
Genoma Bacteriano , Bacilos Gram-Positivos Formadores de Endosporo/genética , Proteínas de Bactérias/classificação , Proteínas de Bactérias/genética , Carbono/metabolismo , Metabolismo Energético/genética , Bacilos Gram-Positivos Formadores de Endosporo/isolamento & purificação , Hidrogênio/metabolismo , Nitrogênio/metabolismo , Oxirredução , Filogenia , RNA Ribossômico 16S/química , RNA Ribossômico 16S/genética , Proteínas Ribossômicas/classificação , Proteínas Ribossômicas/genética , Análise de Sequência de RNA , Enxofre/metabolismo
13.
J Biol Chem ; 289(52): 35907-17, 2014 Dec 26.
Artigo em Inglês | MEDLINE | ID: mdl-25359777

RESUMO

Exopolysaccharides are required for the development and integrity of biofilms produced by a wide variety of bacteria. In staphylococci, partial de-N-acetylation of the exopolysaccharide poly-ß-1,6-N-acetyl-d-glucosamine (PNAG) by the extracellular protein IcaB is required for biofilm formation. To understand the molecular basis for PNAG de-N-acetylation, the structure of IcaB from Ammonifex degensii (IcaBAd) has been determined to 1.7 Å resolution. The structure of IcaBAd reveals a (ß/α)7 barrel common to the family four carbohydrate esterases (CE4s) with the canonical motifs circularly permuted. The metal dependence of IcaBAd is similar to most CE4s showing the maximum rates of de-N-acetylation with Ni(2+), Co(2+), and Zn(2+). From docking studies with ß-1,6-GlcNAc oligomers and structural comparison to PgaB from Escherichia coli, the Gram-negative homologue of IcaB, we identify Arg-45, Tyr-67, and Trp-180 as key residues for PNAG binding during catalysis. The absence of these residues in PgaB provides a rationale for the requirement of a C-terminal domain for efficient deacetylation of PNAG in Gram-negative species. Mutational analysis of conserved active site residues suggests that IcaB uses an altered catalytic mechanism in comparison to other characterized CE4 members. Furthermore, we identified a conserved surface-exposed hydrophobic loop found only in Gram-positive homologues of IcaB. Our data suggest that this loop is required for membrane association and likely anchors IcaB to the membrane during polysaccharide biosynthesis. The work presented herein will help guide the design of IcaB inhibitors to combat biofilm formation by staphylococci.


Assuntos
Amidoidrolases/química , Proteínas de Bactérias/química , Bacilos Gram-Positivos Formadores de Endosporo/enzimologia , beta-Glucanas/química , Acetilação , Sequência de Aminoácidos , Domínio Catalítico , Sequência Conservada , Cristalografia por Raios X , Interações Hidrofóbicas e Hidrofílicas , Simulação de Acoplamento Molecular , Dados de Sequência Molecular , Ligação Proteica , Estrutura Secundária de Proteína , Zinco/química
14.
J Nutr ; 144(11): 1787-96, 2014 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-25332478

RESUMO

BACKGROUND: The modulation of gut microbiota is considered to be the first target to establish probiotic efficacy in a healthy population. OBJECTIVE: This study was conducted to determine the impact of a probiotic on the intestinal microbial ecology of healthy volunteers. METHODS: High-throughput 16S ribosomal RNA gene sequencing was used to characterize the fecal microbiota in healthy adults (23-55 y old) of both sexes, before and after 4 wk of daily consumption of a capsule containing at least 24 billion viable Lactobacillus paracasei DG cells, according to a randomized, double-blind, crossover placebo-controlled design. RESULTS: Probiotic intake induced an increase in Proteobacteria (P = 0.006) and in the Clostridiales genus Coprococcus (P = 0.009), whereas the Clostridiales genus Blautia (P = 0.036) was decreased; a trend of reduction was also observed for Anaerostipes (P = 0.05) and Clostridium (P = 0.06). We also found that the probiotic effect depended on the initial butyrate concentration. In fact, participants with butyrate >100 mmol/kg of wet feces had a mean butyrate reduction of 49 ± 21% and a concomitant decrease in the sum of 6 Clostridiales genera, namely Faecalibacterium, Blautia, Anaerostipes, Pseudobutyrivibrio, Clostridium, and Butyrivibrio (P = 0.021), after the probiotic intervention. In contrast, in participants with initial butyrate concentrations <25 mmol/kg of wet feces, the probiotic contributed to a 329 ± 255% (mean ± SD) increment in butyrate concomitantly with an ∼55% decrease in Ruminococcus (P = 0.016) and a 150% increase in an abundantly represented unclassified Bacteroidales genus (P = 0.05). CONCLUSIONS: The intake of L. paracasei DG increased the Blautia:Coprococcus ratio, which, according to the literature, can potentially confer a health benefit on the host. The probiotic impact on the microbiota and on short-chain fatty acids, however, seems to strictly depend on the initial characteristics of the intestinal microbial ecosystem. In particular, fecal butyrate concentrations could represent an important biomarker for identifying subjects who may benefit from probiotic treatment. This trial was registered at www.controlled-trials.com/isrctn as ISRCTN56945491.


Assuntos
Ácido Butírico/química , Fezes/química , Fezes/microbiologia , Bacilos Gram-Positivos Formadores de Endosporo/isolamento & purificação , Lactobacillus , Adulto , Ácido Butírico/metabolismo , Método Duplo-Cego , Feminino , Bacilos Gram-Positivos Formadores de Endosporo/classificação , Humanos , Masculino , Pessoa de Meia-Idade , Probióticos , Adulto Jovem
15.
Orthopedics ; 37(8): e669-72, 2014 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-25102500

RESUMO

Bone grafts are used for reconstructing bone defects caused by implant-associated complications, trauma, and tumors. Surgery with bone allografts is complex and time consuming; therefore, it is prone to a higher infection rate (2.0%-2.5%). In the case of site infection, systemically administered antibiotics cannot reach the infected bone graft. This study evaluated the use of resorbable bone graft substitute powder (HERAFILL; Heraeus Medical GmbH, Wehrheim, Germany) as a bone void-filling material as well as an antibiotic carrier for mixing with bone grafts. The antibiotic activity of the bone chips mixed with HERAFILL powder was measured by drug release tests and bacterial susceptibility with Bacillus subtilis, Staphylococcus epidermidis, and Staphylococcus aureus. HERAFILL powder was added to the bone chips (bone chips/HERAFILL; w/w = 1:1), mixed with a spatula, and vortexed for 1 minute. Gentamicin base release was evaluated in phosphate-buffered saline for up to 7 days using B subtilis bioassay. Antimicrobial efficacy was tested with S aureus and S epidermidis. The average amount of gentamicin base released from bone chips mixed with HERAFILL at 0 to 12 hours was 99.66 mg/mL. On day 7, the gentamicin base released 0.42 mg/mL. The elution released from bone chips mixed with HERAFILL promoted the formation of a zone of inhibition on S epidermidis and S aureus plates. This study confirmed the capacity of bone grafts to act as antibiotic carriers once mixed with HERAFILL powder. Bone chips mixed with HERAFILL showed efficacy against S aureus and S epidermidis.


Assuntos
Antibacterianos/farmacologia , Substitutos Ósseos , Gentamicinas/farmacologia , Bacilos Gram-Positivos Formadores de Endosporo/efeitos dos fármacos , Antibacterianos/administração & dosagem , Bacillus subtilis/efeitos dos fármacos , Substitutos Ósseos/farmacologia , Carbonato de Cálcio , Portadores de Fármacos , Gentamicinas/administração & dosagem , Humanos , Testes de Sensibilidade Microbiana , Pós , Staphylococcus aureus/efeitos dos fármacos , Staphylococcus epidermidis/efeitos dos fármacos
16.
Appl Biochem Biotechnol ; 174(4): 1613-1630, 2014 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-25138597

RESUMO

The microbial synthesis of environment-friendly poly(3-hydroxybutyrate--co-3-hydroxyvalerate), PHBV, has been performed by using an alkaliphilic microorganism, Alkaliphilus oremlandii OhILAs strain (GenBank Accession number NR_043674.1), at pH 8 and at a temperature of 30-32 °C through the biodegradation of linseed oil-based elastomer. The yield of the copolymer on dry cell weight basis is 90 %. The elastomers used for the biodegradation have been synthesized by cationic polymerization technique. The yield of the PHBV copolymer also varies with the variation of linseed oil content (30-60 %) in the elastomer. Spectroscopic characterization ((1)H NMR and FTIR) of the accumulated product through biodegradation of linseed oil-based elastomers indicates that the accumulated product is a PHBV copolymer consisting of 13.85 mol% of 3-hydroxyvalerate unit. The differential scanning calorimetry (DSC) results indicate a decrease in the melting (T m) and glass transition temperature (T g) of PHBV copolymer with an increase in the content of linseed oil in the elastomer, which is used for the biodegradation. The gel permeation chromatography (GPC) results indicate that the weight average molecular weight (M w) of PHBV copolymer decreases with an increasing concentration of linseed oil in the elastomer. The surface morphology of the elastomer before and after biodegradation is observed under scanning electron microscope (SEM) and atomic force microscope (AFM); these results indicate about porous morphology of the biodegraded elastomer.


Assuntos
Elastômeros/metabolismo , Bacilos Gram-Positivos Formadores de Endosporo/metabolismo , Óleo de Semente do Linho/metabolismo , Poliésteres/metabolismo , Elastômeros/química , Óleo de Semente do Linho/química , Espectroscopia de Ressonância Magnética , Poliésteres/química , Espectroscopia de Infravermelho com Transformada de Fourier
17.
Int J Syst Evol Microbiol ; 64(Pt 11): 3792-7, 2014 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-25142210

RESUMO

A novel bacterial strain designated CB4(T) was isolated from soil from the Hallasan, Jeju, Korea. Strain CB4(T) was found to be strictly aerobic, Gram-stain-positive, rod-shaped, motile and formed creamy greyish colonies on nutrient agar. The major fatty acids were identified as iso-C(15:0) and iso-C(16:0), and the predominant isoprenoid quinone as MK-7. The cell-wall peptidoglycan contained glycine and alanine as the diagnostic amino acids and phosphatidyl-N-methylethanolamine, phosphatidylethanolamine, diphosphatidylglycerol and an unidentified aminophospholipid as the polar lipids. The genomic DNA G+C content of strain CB4(T) was 46.5 mol%. Phylogenetic analysis, based on 16S rRNA gene sequence similarities, showed that strain CB4(T) forms a deep branch within the genus Aneurinibacillus, sharing the highest level of sequence homology with Aneurinibacillus aneurinilyticus DSM 5562(T) (96.5%). On the basis of the phenotypic, chemotaxonomic and phylogenetic characteristics, strain CB4(T) is considered to represent a novel species within the genus Aneurinibacillus, for which the name Aneurinibacillus soli sp. nov. is proposed. The type strain is CB4(T) ( =KCTC 33505(T) =CECT 8566(T)). An emended description of the genus Aneurinibacillus is also proposed.


Assuntos
Bacilos Gram-Positivos Formadores de Endosporo/classificação , Filogenia , Microbiologia do Solo , Técnicas de Tipagem Bacteriana , Composição de Bases , DNA Bacteriano/genética , Ácidos Graxos/química , Bacilos Gram-Positivos Formadores de Endosporo/genética , Bacilos Gram-Positivos Formadores de Endosporo/isolamento & purificação , Dados de Sequência Molecular , Peptidoglicano/química , RNA Ribossômico 16S/genética , República da Coreia , Análise de Sequência de DNA , Vitamina K 2/análogos & derivados , Vitamina K 2/química
18.
Int J Syst Evol Microbiol ; 64(Pt 10): 3375-83, 2014 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-25013225

RESUMO

Three novel moderately anaerobic, thermophilic, rod-shaped bacterial strains, KY38(T), KY46(T) and KA13(T), were isolated from shellfish collected on the Pacific coastline of Enoshima, Japan. Phylogenetic analysis of the 16S rRNA gene sequences indicated that these bacteria belong to the genus Symbiobacterium, sharing sequence similarities of 97.8% (KY38(T)), 96.4% (KY46(T)) and 93.3% (KA13(T)) with the type strain of Symbiobacterium thermophilum, the only species of the genus with a validly published name. These isolates reduced nitrate and grew optimally at 55-60 °C. Strains KY38(T) and KA13(T) formed endospore-like structures in the terminal or subterminal part of their cells at low frequencies. Genomic DNA G+C contents were 68.8 (KY38(T)), 67.2 (KY46(T)) and 67.1 (KA13(T)) mol%. The isolates all presented the predominant menaquinone MK-6, major fatty acids iso-C15:0, C16:0 and iso-C17:0 and the major polar lipids phosphatidylglycerol, phosphatidylethanolamine and unknown glycol-containing phospholipids. On the basis of their morphological, physiological and phylogenetic properties, strains KY38(T), KY46(T) and KA13(T) represent three novel species, for which the names Symbiobacterium ostreiconchae sp. nov. (type strain KY38(T) = DSM 27624(T) = KCTC 4567(T) = JCM 15048(T)), Symbiobacterium turbinis sp. nov. (type strain KY46(T) = DSM 27625(T) = KCTC 4568(T) = JCM 15996(T)) and Symbiobacterium terraclitae sp. nov. (type strain KA13(T) = DSM 27138(T) = KCTC 4569(T) = JCM 15997(T)) are proposed. An emended description of the genus Symbiobacterium is also presented. The phylogenetic distinctiveness of the genus Symbiobacterium indicates its affiliation with a novel family, for which the name Symbiobacteriaceae fam. nov. is proposed.


Assuntos
Bacilos Gram-Positivos Formadores de Endosporo/classificação , Filogenia , Frutos do Mar/microbiologia , Técnicas de Tipagem Bacteriana , Composição de Bases , DNA Bacteriano/genética , Ácidos Graxos/química , Bacilos Gram-Positivos Formadores de Endosporo/genética , Bacilos Gram-Positivos Formadores de Endosporo/isolamento & purificação , Japão , Dados de Sequência Molecular , Fosfolipídeos/química , RNA Ribossômico 16S/genética , Análise de Sequência de DNA , Vitamina K 2/análogos & derivados , Vitamina K 2/química
19.
Proc Natl Acad Sci U S A ; 111(24): 8931-6, 2014 Jun 17.
Artigo em Inglês | MEDLINE | ID: mdl-24889625

RESUMO

Ethanol is the most widely used renewable transportation biofuel in the United States, with the production of 13.3 billion gallons in 2012 [John UM (2013) Contribution of the Ethanol Industry to the Economy of the United States]. Despite considerable effort to produce fuels from lignocellulosic biomass, chemical pretreatment and the addition of saccharolytic enzymes before microbial bioconversion remain economic barriers to industrial deployment [Lynd LR, et al. (2008) Nat Biotechnol 26(2):169-172]. We began with the thermophilic, anaerobic, cellulolytic bacterium Caldicellulosiruptor bescii, which efficiently uses unpretreated biomass, and engineered it to produce ethanol. Here we report the direct conversion of switchgrass, a nonfood, renewable feedstock, to ethanol without conventional pretreatment of the biomass. This process was accomplished by deletion of lactate dehydrogenase and heterologous expression of a Clostridium thermocellum bifunctional acetaldehyde/alcohol dehydrogenase. Whereas wild-type C. bescii lacks the ability to make ethanol, 70% of the fermentation products in the engineered strain were ethanol [12.8 mM ethanol directly from 2% (wt/vol) switchgrass, a real-world substrate] with decreased production of acetate by 38% compared with wild-type. Direct conversion of biomass to ethanol represents a new paradigm for consolidated bioprocessing, offering the potential for carbon neutral, cost-effective, sustainable fuel production.


Assuntos
Biocombustíveis , Biomassa , Etanol/química , Bacilos Gram-Positivos Formadores de Endosporo/química , Acetaldeído/química , Álcool Desidrogenase/química , Clostridium thermocellum/enzimologia , Fontes Geradoras de Energia , Fermentação , L-Lactato Desidrogenase/química , Lignina/química , Engenharia de Proteínas
20.
Int J Syst Evol Microbiol ; 64(Pt 8): 2657-61, 2014 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-24827706

RESUMO

A novel strictly anaerobic, halotolerant, organotrophic bacterium, strain P3M-3(T), was isolated from a microbial mat formed under the flow of hot water emerging from a 2775 m-deep well in Tomsk region (western Siberia, Russia). Cells of strain P3M-3(T) were straight and curved rods, 0.2-0.4 µm in width and 1.5-20 µm in length. Strain P3M-3(T) grew optimally at 37 °C, pH 7.0-7.5 and in a NaCl concentration of 15 g l(-1). Under optimum growth conditions, the doubling time was 1 h. The isolate was able to ferment a variety of mono-, di- and polysaccharides, including microcrystalline cellulose. Acetate, ethanol, H2 and CO2 were the main products of glucose fermentation. The DNA G+C content was 33.4 mol%. 16S rRNA gene-based phylogenetic analysis showed that strain P3M-3(T) was a member of family Lachnospiraceae, whose representatives are also found in Clostridium cluster XIVa. 16S rRNA gene sequence similarity with Clostridium jejuense HY-35-12(T), the closest relative, was 93.9%. A novel genus and species, Mobilitalea sibirica gen. nov., sp. nov., are proposed based on phylogenetic analysis and physiological properties of the novel isolate. The type strain of the type species is P3M-3(T) ( = DSM 26468(T) = VKM B-2804(T)).


Assuntos
Bacilos Gram-Positivos Formadores de Endosporo/classificação , Filogenia , Microbiologia da Água , Poços de Água/microbiologia , Bactérias Anaeróbias/classificação , Bactérias Anaeróbias/genética , Bactérias Anaeróbias/isolamento & purificação , Técnicas de Tipagem Bacteriana , Composição de Bases , DNA Bacteriano/genética , Ácidos Graxos/química , Fermentação , Bacilos Gram-Positivos Formadores de Endosporo/genética , Bacilos Gram-Positivos Formadores de Endosporo/isolamento & purificação , Temperatura Alta , Dados de Sequência Molecular , Fosfolipídeos/química , Polissacarídeos/metabolismo , RNA Ribossômico 16S/genética , Federação Russa , Tolerância ao Sal , Análise de Sequência de DNA
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