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1.
An Acad Bras Cienc ; 91(3): e20180694, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31618412

RESUMO

The strains CM-Z19 and CM-Z6, which are capable of highly degrading chlorpyrifos-methyl, were isolated from soil. They were identified as Bacillus megaterium CM-Z19 and Pseudomonas syringae CM-Z6, respectively, based on the 16S rRNA and an analysis of their morphological, physiological and biochemical characteristics. The strain CM-Z19 showed 92.6% degradation of chlorpyrifos-methyl (100 mg/L) within 5 days of incubation, and the strain CM-Z6 was 99.1% under the same conditions. In addition, the degradation characteristics of the two strains were compared and studied, and the results showed that the strain CM-Z19 had higher phosphoesterase activity and ability to degrade the organophosphorus pesticide than did the strain CM-Z6. However, the strain CM-Z19 could not degrade its first hydrolysis metabolite 3,5,6-trichloro-2-pyridinol (TCP) and could not completely degrade chlorpyrifos-methyl. The strain CM-Z6 could effectively degrade TCP and could degrade chlorpyrifos-methyl more quickly than strain CM-Z19.


Assuntos
Bacillus megaterium/metabolismo , Biodegradação Ambiental , Clorpirifos/análogos & derivados , Praguicidas/metabolismo , Pseudomonas syringae/metabolismo , Bacillus megaterium/isolamento & purificação , Clorpirifos/isolamento & purificação , Clorpirifos/metabolismo , Inseticidas/isolamento & purificação , Inseticidas/metabolismo , Praguicidas/isolamento & purificação , Pseudomonas syringae/isolamento & purificação , RNA Ribossômico 16S/metabolismo , Microbiologia do Solo
2.
Pestic Biochem Physiol ; 159: 68-79, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31400786

RESUMO

Chlorpyrifos is a pesticide frequently detected in food and has been reported to disturb endocrine and gut health, which was regulated by gut microbiota and enteroendocrine cells. In this study, newly weaned (3 week) and adult (8 week) male rats fed a normal- or high- fat diet were chronically exposed to 0.3 mg chlorpyrifos/kg bodyweight/day. The effects of chlorpyrifos exposure on serum hormone levels, proinflammatory cytokines and gut microbiota were evaluated. Chronic exposure to chlorpyrifos significantly decreased the concentrations of luteinizing hormone, follicule stimulating hormone and testosterone, which was found only in the normal-fat diet. The counteracted effect of high-fat diet was also found in gut hormones and proinflammatory cytokines. Significantly higher concentrations of glucagon-like peptide-1, pancreatic polypeptide, peptide tyrosine tyrosine (PYY), ghrelin, gastric inhibitory poly-peptide, IL-6, monocyte chemoattractant protein-1, and TNF-α were found in rats exposed to chlorpyrifos beginning at newly weaned, whereas only the PYY, ghrelin and IL-6 concentrations increased significantly in rats exposed in adulthood. Furthermore, a decrease in epinephrine induced by chlorpyrifos exposure was found in rats exposed to chlorpyrifos beginning at newly weaned, regardless of their diet. Chlorpyrifos-induced disturbances in the microbiome community structure were more apparent in rats fed a high-fat diet and exposed beginning at newly weaned. The affected bacteria included short-chain fatty acid-producing bacteria (Romboutsia, Turicibacter, Clostridium sensu stricto 1, norank_f_Coriobacteriaceae, Faecalibaculum, Parasutterella and norank_f__Erysipelotrichaceae), testosterone-related genus (Turicibacter, Brevibacterium), pathogenic bacteria (Streptococcus), and inflammation-related bacteria (unclassified_f__Ruminococcaceae, Ruminococcaceae_UCG-009, Parasutterella, Oscillibacter), which regulated the endocrine system via the hypothalamic-pituitary-adrenal axis, as well as the immune response and gut barrier. Early exposure accelerated the endocrine-disturbing effect and immune responses of chlorpyrifos, although these effects can be eased or recovered by a high-fat diet. This study helped clarify the relationship between disrupted endocrine function and gut microbiota dysbiosis induced by food contaminants such as pesticides.


Assuntos
Clorpirifos/toxicidade , Dieta Hiperlipídica/efeitos adversos , Microbioma Gastrointestinal/efeitos dos fármacos , Inflamação/induzido quimicamente , RNA Ribossômico 16S/metabolismo , Envelhecimento , Animais , Sistema Hipotálamo-Hipofisário/efeitos dos fármacos , Inflamação/metabolismo , Masculino , Sistema Hipófise-Suprarrenal/efeitos dos fármacos , Ratos
3.
J Appl Oral Sci ; 27: e20180635, 2019 Jun 13.
Artigo em Inglês | MEDLINE | ID: mdl-31215600

RESUMO

OBJECTIVE: Acetaldehyde, associated with consumption of alcoholic beverages, is known to be a carcinogen and to be related to the tongue dorsum. The aim of this study was to investigate the relationship between acetaldehyde concentration in mouth air and bacterial characteristics on the tongue dorsum. METHODOLOGY: Thirty-nine healthy volunteers participated in the study. Acetaldehyde concentrations in mouth air were evaluated by a high-sensitivity semiconductor gas sensor. A 16S rRNA gene sequencing technique was used to compare microbiomes between two groups, focusing on the six samples with the highest acetaldehyde concentrations (HG) and the six samples with lowest acetaldehyde concentrations (LG). RESULTS: Acetaldehyde concentration increased in correlation with the increase in bacterial count (p=0.048). The number of species observed in the oral microbiome of the HG was higher than that in the oral microbiome of the LG (p=0.011). The relative abundances of Gemella sanguinis, Veillonella parvula and Neisseria flavescens in the oral microbiome of the HG were higher than those in the oral microbiome of the LG (p<0.05). CONCLUSION: Acetaldehyde concentration in mouth air was associated with bacterial count, diversity of microbiome, and relative abundance of G. sanguinis, V. parvula, and N. flavescens.


Assuntos
Acetaldeído/análise , Microbiota , Boca/química , Língua/microbiologia , Acetaldeído/metabolismo , Adulto , Consumo de Bebidas Alcoólicas/metabolismo , Bactérias/genética , Bactérias/isolamento & purificação , Carga Bacteriana , Candida/isolamento & purificação , Estudos Transversais , Feminino , Humanos , Japão , Masculino , Boca/metabolismo , Boca/microbiologia , RNA Ribossômico 16S/análise , RNA Ribossômico 16S/metabolismo , Valores de Referência , Fumar/metabolismo , Estatísticas não Paramétricas , Inquéritos e Questionários , Língua/metabolismo , Adulto Jovem
4.
Chemosphere ; 231: 457-467, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31151005

RESUMO

In this study, the novel up-flow anaerobic sludge blanket coupled with bioelectrocatalytic system (UASB-BEC) was developed with the attempt to enhance treatment of acetyl pyrimidine-containing wastewater. The results revealed that higher current applied had a positive effect on acetyl pyrimidine (AP) degradation but a negative impact could be followed by the overhigh current (>1.26 A m-3). Removal efficiencies of AP and total organic carbon (TOC) were as high as 96.3 ±â€¯2.6% and 92.9 ±â€¯3.2% while methane production reached up to 0.70 ±â€¯0.03 NL-CH4 L-1-reactor d-1 at applied current of 1.26 A m-3, which were significantly higher those in control system. Moreover, high-throughput 16S rRNA gene pyrosequencing further indicated that Desulfovibrio and Methanimicrococcus species were specially enriched in suspended sludge and cathodic biofilm with current involvement. It could be reasonably speculated that enrichment of Desulfovibrio and Methanimicrococcus species could promote biotransformation of AP and final H2-depended methylotrophic methanogenesis. This study could shed light on better understanding of AP transformation in bioelectrocatalytic system and provide a valuable reference to practical application of anaerobic AP-containing wastewater treatment.


Assuntos
Pirimidinas/metabolismo , Eliminação de Resíduos Líquidos/métodos , Poluentes Químicos da Água/metabolismo , Anaerobiose , Biofilmes , Reatores Biológicos , Metano/metabolismo , Pirimidinas/análise , RNA Ribossômico 16S/metabolismo , Esgotos , Águas Residuárias , Poluentes Químicos da Água/análise
5.
Bioelectrochemistry ; 128: 291-297, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31059969

RESUMO

A biocathode microbial fuel cell was constructed to investigate Congo red decolorization and power generation under different cathode operational parameters. The results showed that the suspended sludge in the cathode could improve the performance of the microbial fuel cell for electricity generation but had a negligible effect on the Congo red decolorization. The maximum voltage increased as the aeration rate was increased up to 100 mL/min. At aeration rates of 150 and 200 mL/min, the maximum voltage was lower than that at 100 mL/min. In the meantime, the Congo red decolorization efficiency decreased with increasing cathode aeration rate. These results showed that excessive aeration is not favorable in a bio-cathode microbial fuel cell used for simultaneous Congo red decolorization and electricity generation. The addition of Mn2+ to the biocathode resulted in a 74.5% increase in maximum power density but had no effect on Congo red decolorization. SEM and 16S rRNA sequencing analysis confirmed that Mn2+ was involved in the electrochemical reaction of the biocathode as an electron mediator, and it could induce a difference in the biocathode-attached populations.


Assuntos
Fontes de Energia Bioelétrica , Cor , Corantes/química , Vermelho Congo/química , Eletricidade , Eletrodos , Biofilmes , Manganês/química , Microscopia Eletrônica de Varredura , RNA Ribossômico 16S/metabolismo , Esgotos
6.
BMC Infect Dis ; 19(1): 334, 2019 Apr 23.
Artigo em Inglês | MEDLINE | ID: mdl-31014269

RESUMO

BACKGROUND: Ralstonia picketti, Ralstonia mannitolilytica, and Ralstonia insidiosa have recently been regarded as emerging pathogens of infectious diseases, in particular as the pathogens responsible for nosocomial infection in immunocompromised patients. R. insidiosa differs from R. picketti and R. mannitolilytica, and its related infections are rarely reported. METHODS: Clinical data from two nosocomial bloodstream infection cases were extracted and analyzed. The causable isolates were identified by the VITEK 2 Compact system, matrix assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS), and molecular identification methods using PCR with universal and species-specific primers. Antimicrobial susceptibility testing was performed using the broth microdilution method. Both of the isolates were subjected to whole genome sequencing using a HiSeq X10 Sequencer. Antimicrobial resistance genes, virulence factors, and plasmid replicons were identified from assembled genomes. A real-time RT-PCR experiment and a cloning experiment were conducted to explore the related class D ß-lactamase-encoding genes. RESULTS: Both patients recovered under therapy with antibiotics. Isolates were initially misidentified as R. mannitolilytica by the VITEK 2 Compact system rather than R. insidiosa, as identified by both MALDI-TOF MS and 16S rRNA gene sequencing. Both isolates were resistant to aminoglycosides, ß-lactams, and polymyxin B. One isolate harboring blaOXA-570 was resistant to carbapenems. The whole genome sequencing data confirmed species identification based on average nucleotide identity (ANI) and revealed two variants of class D ß-lactamase-encoding gene blaOXA (blaOXA-573 and blaOXA-574). The real-time RT-PCR experiment showed no difference in gene expression between blaOXA-570 and blaOXA-573 in our strains. The cloning experiment showed that variant OXA-573 had no carbapenem hydrolase activity. CONCLUSIONS: We described two cases of nosocomial bloodstream infection caused by R. insidiosa strains. MALDI-TOF MS was cost-effective for rapid species identification. Clinicians should be aware that R. insidiosa can be resistant to commonly used antibiotics, even carbapenems.


Assuntos
Infecção Hospitalar/diagnóstico , Ralstonia/isolamento & purificação , Adulto , Antibacterianos/farmacologia , Antibacterianos/uso terapêutico , Carbapenêmicos/farmacologia , Carbapenêmicos/uso terapêutico , Infecção Hospitalar/tratamento farmacológico , Infecção Hospitalar/microbiologia , Farmacorresistência Bacteriana , Humanos , Masculino , Testes de Sensibilidade Microbiana , Filogenia , Reação em Cadeia da Polimerase , RNA Ribossômico 16S/metabolismo , Ralstonia/classificação , Ralstonia/efeitos dos fármacos , Ralstonia/genética , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz , Sequenciamento Completo do Genoma
7.
Curr Microbiol ; 76(7): 810-817, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31030270

RESUMO

The complex gut microbiota plays a key role in host metabolism and health. However, the core microbial communities in the different aged Bactrian camels remain totally unclear. We used high-throughput 16S rRNA gene sequencing to examine the temporal variability of the fecal microbiota in Bactrian camels. At 2 months of age, the fecal microbiota was composed of Firmicutes, Proteobacteria, and Actinobacteria. At 1 and 3 years of age, the fecal microbiota was dominated by Firmicutes, Bacteroidetes, and Verrucomicrobia. At the genus level, Blautia, Fusobacterium, and Bifidobacterium were more abundant at 2 months of age, as well as Escherichia-Shigella. Ruminococcaceae_UCG-005, Akkermansia, and Christensenellaceae_R-7_group were the most abundant at 1 and 3 years of age. Diversity and stability of the gut microbiota increased with age. There was enrichment for genes associated with immune system diseases at 2 months of age. This study is the first to investigate the distribution of the gut microbiota in Bactrian camels with different ages and provide a baseline for future camel microbiology research.


Assuntos
Bactérias/genética , Biodiversidade , Camelus/microbiologia , Microbioma Gastrointestinal , Sequenciamento de Nucleotídeos em Larga Escala , Fatores Etários , Animais , Bactérias/classificação , Bactérias/isolamento & purificação , Bactérias/metabolismo , China , DNA Bacteriano/genética , Fezes/microbiologia , Microbioma Gastrointestinal/genética , Genoma Bacteriano/genética , Anotação de Sequência Molecular , RNA Ribossômico 16S/metabolismo , Análise de Sequência de DNA
8.
Psychopharmacology (Berl) ; 236(5): 1623-1640, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-30900006

RESUMO

RATIONALE: Researchers in psychiatry and neuroscience are increasingly recognizing the importance of gut-brain communication in mental health. Both genetics and environmental factors influence gut microbiota composition and function. This study examines host-microbe signaling at the gastrointestinal barrier to identify bottom-up mechanisms of microbiota-brain communication. OBJECTIVES: We examined differences in gut microbiota composition and fecal miRNA profiles in BALB/c and C57BL/6 mice, in relation to gastrointestinal homeostasis and evaluated the response to perturbation of the gut microbiota by broad-spectrum antibiotic treatment. METHODS AND RESULTS: Differences in the gut microbiota composition between BALB/c and C57BL/6 mice, evaluated by fecal 16S rRNA gene sequencing, included significant differences in genera Prevotella, Alistipes, Akkermansia, and Ruminococcus. Significant differences in fecal miRNA profiles were determined using the nCounter NanoString platform. A BLASTn analysis identified conserved fecal miRNA target regions in bacterial metagenomes with 14 significant correlations found between fecal miRNA and predicted taxa relative abundance in our dataset. Treatment with broad-spectrum antibiotics for 2 weeks resulted in a host-specific physiological response at the gastrointestinal barrier including a decrease in barrier permeability in BALB/c mice and alterations in the expression of barrier regulating genes in both strains. Genera Parabacteroides and Bacteroides were associated with changes in barrier function. CONCLUSIONS: The results of this study provide insight into how specific taxa influence gut barrier integrity and function. More generally, these data in the context of recent published studies makes a significant contribution to our understanding of host-microbe interactions providing new knowledge that can be harnessed by us and others in future mechanistic studies.


Assuntos
Microbioma Gastrointestinal/fisiologia , Trato Gastrointestinal/metabolismo , Homeostase/fisiologia , Interações entre Hospedeiro e Microrganismos/fisiologia , Animais , Fezes/microbiologia , Feminino , Trato Gastrointestinal/microbiologia , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , RNA Ribossômico 16S/genética , RNA Ribossômico 16S/metabolismo , Especificidade da Espécie
9.
Psychopharmacology (Berl) ; 236(5): 1531-1544, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-30903211

RESUMO

RATIONALE: Increasing evidence has demonstrated that changes in the gut microbiome, including those associated with dietary influences, are associated with alterations in many physiological processes. Alcohol consumption is common across human cultures and is likely to have a major effect on the gut microbiome, but there remains a paucity of information on its effects in primates. OBJECTIVES: The effects of chronic alcohol consumption on the primate gut microbiome and metabolome were studied in rhesus macaques that were freely drinking alcohol. The objectives of the study were to determine what changes occurred in the gut microbiome following long-term exposure to alcohol and if these changes were reversible following a period of abstinence. METHODS: Animals consuming alcohol were compared to age-matched controls without access to alcohol and were studied before and after a period of abstinence. Fecal samples from rhesus macaques were used for 16S rRNA sequencing to profile the gut microbiome and for metabolomic profiling using mass spectrometry. RESULTS: Alcohol consumption resulted in a loss of alpha-diversity in rhesus macaques, though this was partially ameliorated by a period of abstinence. Higher levels of Firmicutes were observed in alcohol-drinking animals at the expense of a number of other microbial taxa, again normalizing in part with a period of abstinence. Metabolomic changes were primarily associated with differences in glycolysis when animals were consuming alcohol and differences in fatty acids when alcohol-drinking animals became abstinent. CONCLUSIONS: The consumption of alcohol has specific effects on the microbiome and metabolome of rhesus macaques independent of secondary influences. Many of these changes are reversed by a relatively short period of abstinence.


Assuntos
Consumo de Bebidas Alcoólicas/efeitos adversos , Etanol/toxicidade , Microbioma Gastrointestinal/efeitos dos fármacos , Metaboloma/efeitos dos fármacos , Consumo de Bebidas Alcoólicas/genética , Consumo de Bebidas Alcoólicas/metabolismo , Animais , Etanol/administração & dosagem , Fezes/microbiologia , Microbioma Gastrointestinal/fisiologia , Humanos , Macaca mulatta , Masculino , Metaboloma/fisiologia , RNA Ribossômico 16S/genética , RNA Ribossômico 16S/metabolismo
10.
BMC Infect Dis ; 19(1): 234, 2019 Mar 07.
Artigo em Inglês | MEDLINE | ID: mdl-30845929

RESUMO

BACKGROUND: The study of stool microbiota has taken great relevance in the last years, given its role in the maintenance of the intestinal metabolic, physiological, and immunological homeostasis, as well as, its effect over HIV biomarkers levels such as CD4/CD8 ratio, high sensitivity C-Reactive Protein (hs-CRP), related to poor outcomes (rapid progression to AIDS). Several efforts have been made to characterize the gut microbiome. In HIV infection, most of the studies report the presence of a dysbiotic pattern; however, few of them have made an approach in elderly HIV-positive subjects despite the fact that nowadays this subgroup is rising. In this study, we compared the composition of faecal microbiota, Short Chain Fatty Acids (SCFAs), and systemic biomarkers between elderly HIV-positive and HIV-negative subjects. METHODS: A cross-sectional study with 18 HIV-negative controls and 20 HIV-positive patients. The quantification of Bacteroidetes, Firmicutes, Proteobacteria, Actinobacteria, Lactobacillus, Enterobacteriaceae, Bifidobacterium, Escherichia coli, Clostridium leptum, Clostridium coccoides was performed in faecal samples by qPCR. The analysis was performed by calculating the ΔCq of each microorganism using 16S rDNA as a reference gene. Faecal SCFAs were measured by HPLC. The hs-CRP and sCD14 were performed by ELISA. RESULTS: An increase in the Firmicutes/Bacteroidetes ratio, coupled with a significant increase in the proteobacteria phylum was detected in HIV-positive subjects. In contrast, a decrease in the Clostridium leptum group was observed. Nevertheless, these elderly HIV-positive patients showed higher levels of total SCFAs mainly by an augmented propionic acid values, compared to HIV-negative subjects. Whereas high levels of hs-CRP were positively correlated with sCD14 in the HIV-positive group. CONCLUSIONS: Alterations in bacterial communities reveals a dysbiotic state related to an unbalance of faecal SCFAs. Therefore, these intestinal conditions might drive an increase of poor prognostic biomarkers in elderly HIV-positive subjects.


Assuntos
Bactérias/genética , Biomarcadores/análise , Ácidos Graxos Voláteis/análise , Microbioma Gastrointestinal , Infecções por HIV/patologia , Idoso , Bactérias/isolamento & purificação , Proteína C-Reativa/análise , Contagem de Linfócito CD4 , Cromatografia Líquida de Alta Pressão , Estudos Transversais , Ensaio de Imunoadsorção Enzimática , Fezes/microbiologia , Feminino , Humanos , Receptores de Lipopolissacarídeos/análise , Masculino , México , Pessoa de Meia-Idade , RNA Ribossômico 16S/genética , RNA Ribossômico 16S/metabolismo , Reação em Cadeia da Polimerase em Tempo Real
11.
J Dairy Sci ; 102(5): 4025-4040, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-30827551

RESUMO

Nine Holstein dairy cows were fed diets with increasing proportions of rapidly fermentable carbohydrates (RFCH) to investigate the effect on reticular pH, milk fat content (MFC), 18-carbon fatty acid proportions in blood plasma and milk, and bacterial community in buccal swab samples. Inter-animal variation was expected in terms of reticular pH response upon higher RFCH proportions, which would be reflected in the occurrence or not of milk fat depression (MFD). Moreover, this variation in occurrence of MFD was hypothesized to be related to differences in blood and milk fatty acid proportions and in the bacterial community in buccal samples. Cows were fed a total mixed ration throughout the experiment, which consisted of 4 periods: adaptation (d 0-4) and low (d 5-18), increasing (d 19-24), and high RFCH (d 25-28). During the increasing RFCH period, the standard concentrate (211 g of starch/kg of dry matter) was gradually and partly replaced by a concentrate high in RFCH (486 g of starch/kg of dry matter). The reticular pH was measured using a bolus and the time below pH 6.00 was calculated on a daily basis. On d 13, 14, 25, 27, and 28, plasma and milk samples were collected and analyzed for 18-carbon fatty acid proportions, and buccal swabs were collected for bacterial community analysis based on 16S rRNA gene amplicon sequencing. Inter-animal variation was observed in terms of reticular pH, which allowed us to divide the cows into 2 groups: tolerant (time below pH 6.00 ≤ 0.1 h/d) and susceptible cows (time below pH 6.00 ≥ 1.26 h/d). The lower reticular pH of susceptible cows was accompanied by lower MFC. Both groups already differed in reticular pH and MFC during the low-RFCH period. Furthermore, higher RFCH amounts did not decrease the reticular pH in either of the 2 groups. Nevertheless, MFD was observed in both groups during the high-RFCH period compared with the low-RFCH period. Lower MFC in animals with lower reticular pH or during the high-RFCH period was associated with a shift in 18-carbon fatty acids toward trans-10 at the expense of trans-11 intermediates, which was observed in plasma as well as in milk samples. Moreover, lower MFC was accompanied by shifts in the relative abundance of specific bacteria in buccal samples. Genera Dialister, Sharpea, Carnobacterium, Acidaminococcus, and uncultured genera belonging to the Betaproteobacteria were more abundant in situations with greater trans-10 proportions.


Assuntos
Bactérias/isolamento & purificação , Suplementos Nutricionais , Ácidos Graxos/metabolismo , Leite/metabolismo , Mucosa Bucal/metabolismo , Rúmen/metabolismo , Animais , Bactérias/classificação , Bactérias/metabolismo , Radioisótopos de Carbono/metabolismo , Bovinos , Dieta/veterinária , Ácidos Graxos/química , Feminino , Fermentação , Concentração de Íons de Hidrogênio , Lactação , RNA Ribossômico 16S/metabolismo , Amido/metabolismo
12.
Nutrients ; 11(3)2019 Mar 04.
Artigo em Inglês | MEDLINE | ID: mdl-30836671

RESUMO

Accumulated data suggests that the gut microbiome can rapidly respond to changes in diet. Consumption of fermented dairy products (FDP) fortified with probiotic microbes may be associated with positive impact on human health. However, the extent and details of the possible impact of FDP consumption on gut community structure tends to vary across individuals. We used microbiome analysis to characterize changes in gut microbiota composition after 30 days of oral intake of a yoghurt fortified with Bifidobacterium animalis subsp. lactis BB-12. 16S rRNA gene sequencing was used to assess the gut microbial composition before and after FDP consumption in healthy adults (n = 150). Paired comparison of gut microbial content demonstrated an increase in presence of potentially beneficial bacteria, particularly, Bifidobacterium genus, as well as Adlercreutzia equolifaciens and Slackia isoflavoniconvertens. At a functional level, an increased capacity to metabolize lactose and synthesize amino acids was observed accompanied by a lowered potential for synthesis of lipopolysaccharides. Cluster analysis revealed that study volunteers segregated into two groups with post-intervention microbiota response that was dependent on the baseline microbial community structure.


Assuntos
Bifidobacterium animalis , Produtos Fermentados do Leite/microbiologia , Ingestão de Alimentos/fisiologia , Microbioma Gastrointestinal/fisiologia , Iogurte/microbiologia , Adulto , Análise por Conglomerados , Fezes/microbiologia , Feminino , Voluntários Saudáveis , Humanos , Masculino , Estudos Prospectivos , RNA Ribossômico 16S/metabolismo
13.
Proc Natl Acad Sci U S A ; 116(14): 6897-6902, 2019 04 02.
Artigo em Inglês | MEDLINE | ID: mdl-30886102

RESUMO

The exergonic reaction of FeS with H2S to form FeS2 (pyrite) and H2 was postulated to have operated as an early form of energy metabolism on primordial Earth. Since the Archean, sedimentary pyrite formation has played a major role in the global iron and sulfur cycles, with direct impact on the redox chemistry of the atmosphere. However, the mechanism of sedimentary pyrite formation is still being debated. We present microbial enrichment cultures which grew with FeS, H2S, and CO2 as their sole substrates to produce FeS2 and CH4 Cultures grew over periods of 3 to 8 mo to cell densities of up to 2 to 9 × 106 cells per mL-1 Transformation of FeS with H2S to FeS2 was followed by 57Fe Mössbauer spectroscopy and showed a clear biological temperature profile with maximum activity at 28 °C and decreasing activities toward 4 °C and 60 °C. CH4 was formed concomitantly with FeS2 and exhibited the same temperature dependence. Addition of either penicillin or 2-bromoethanesulfonate inhibited both FeS2 and CH4 production, indicating a coupling of overall pyrite formation to methanogenesis. This hypothesis was supported by a 16S rRNA gene-based phylogenetic analysis, which identified at least one archaeal and five bacterial species. The archaeon was closely related to the hydrogenotrophic methanogen Methanospirillum stamsii, while the bacteria were most closely related to sulfate-reducing Deltaproteobacteria, as well as uncultured Firmicutes and Actinobacteria. Our results show that pyrite formation can be mediated at ambient temperature through a microbially catalyzed redox process, which may serve as a model for a postulated primordial iron-sulfur world.


Assuntos
Sulfeto de Hidrogênio/metabolismo , Ferro/metabolismo , Methanospirillum , Filogenia , RNA Arqueal , RNA Ribossômico 16S , Sulfetos/metabolismo , Methanospirillum/genética , Methanospirillum/metabolismo , Oxirredução , RNA Arqueal/genética , RNA Arqueal/metabolismo , RNA Ribossômico 16S/genética , RNA Ribossômico 16S/metabolismo
14.
Nanoscale ; 11(8): 3639-3655, 2019 Feb 21.
Artigo em Inglês | MEDLINE | ID: mdl-30741296

RESUMO

Carbon nanomaterials (CNMs) can positively regulate seed germination and enhance plant growth. However, clarification of the impact of plant organs containing absorbed CNMs on animal and human health is a critical step of risk assessment for new nano-agro-technology. In this study, we have taken a comprehensive approach to studying the effect tomato fruits derived from plants exposed to multi-walled carbon nanotubes (CNTs) have on gastrointestinal epithelial barrier integrity and their impact on the human commensal intestinal microbiota using an in vitro cell culture and batch human fecal suspension models. The effects of CNTs on selected pure cultures of Salmonella enterica Typhimurium and Lactobacillus acidophilus were also evaluated. This study demonstrated that CNT-containing fruits or the corresponding residual level of pure CNTs (0.001 µg ml-1) was not sufficient to initiate a significant change in transepithelial resistance and on gene expression of the model T-84 human intestinal epithelial cells. However, at 10 µg ml-1 concentration CNTs were able to penetrate the cell membrane and change the gene expression profile of exposed cells. Moreover, extracts from CNT-containing fruits had minimal to no effect on human intestinal microbiota as revealed by culture-based analysis and 16S rRNA sequencing.


Assuntos
Lycopersicon esculentum/química , Nanotubos de Carbono/química , Linhagem Celular , Fezes/microbiologia , Frutas/química , Frutas/metabolismo , Microbioma Gastrointestinal/efeitos dos fármacos , Humanos , Mucosa Intestinal/citologia , Mucosa Intestinal/efeitos dos fármacos , Mucosa Intestinal/metabolismo , Lactobacillus acidophilus/efeitos dos fármacos , Lactobacillus acidophilus/genética , Lycopersicon esculentum/metabolismo , Nanotubos de Carbono/toxicidade , RNA Ribossômico 16S/química , RNA Ribossômico 16S/genética , RNA Ribossômico 16S/metabolismo , Salmonella typhimurium/efeitos dos fármacos , Salmonella typhimurium/genética , Análise de Sequência de DNA , Análise Espectral Raman
15.
J Antibiot (Tokyo) ; 72(4): 225-236, 2019 04.
Artigo em Inglês | MEDLINE | ID: mdl-30737453

RESUMO

In bacteria, RNase III cleaves the initial long primary ribosomal RNA transcripts/precursors (pre-rRNAs), thereby releasing the pre-16S and pre-23S rRNAs for maturation. This cleavage is specified by the double-stranded secondary structures flanking the mature rRNAs, and not necessarily by the nucleotide sequences. Inhibition of this cleavage would lead to a build-up of pre-rRNA molecules. Doxycycline has earlier been shown to bind synthetic double-stranded RNAs and inhibit their cleavage by RNase III. Since bacterial rRNA processing is primarily dependent on RNase III cleavage (which is inhibited by doxycycline), doxycycline could therefore inhibit the normal processing of bacterial rRNA. In this study, the effect of doxycycline on bacterial rRNA processing was investigated by analyzing the amounts of various rRNAs in growing Escherichia coli cells treated with doxycycline. The results showed a doxycycline dose-dependent decrease in mature 16S and 23S rRNAs, concurrent with an accumulation of the initial rRNA transcripts and long precursors. Morphologically, treated cells were elongated at low drug concentrations, while nucleoid degeneration indicative of cell death occurred at higher drug concentrations. These observations suggest that doxycycline inhibits the cleavage and processing of bacterial rRNA transcripts/precursors, leading to impaired formation of mature rRNAs, and the consequent inhibition of protein synthesis for which the tetracycline group of antibiotics are renowned. Since rRNA structure and processing pathway is conserved among bacterial species, this mechanism may account for the broad spectrum of antibiotic activity and selective microbial protein synthesis inhibition of doxycycline and the tetracyclines.


Assuntos
Antibacterianos/farmacologia , Doxiciclina/farmacologia , Escherichia coli/efeitos dos fármacos , Precursores de RNA/metabolismo , Processamento Pós-Transcricional do RNA/efeitos dos fármacos , RNA Ribossômico 16S/metabolismo , RNA Ribossômico 23S/metabolismo
16.
Nat Commun ; 10(1): 930, 2019 02 25.
Artigo em Inglês | MEDLINE | ID: mdl-30804338

RESUMO

Ribo-T is an engineered ribosome whose small and large subunits are tethered together by linking 16S rRNA and 23S rRNA in a single molecule. Although Ribo-T can support cell proliferation in the absence of wild type ribosomes, Ribo-T cells grow slower than those with wild type ribosomes. Here, we show that cell growth defect is likely explained primarily by slow Ribo-T assembly rather than its imperfect functionality. Ribo-T maturation is stalled at a late assembly stage. Several post-transcriptional rRNA modifications and some ribosomal proteins are underrepresented in the accumulated assembly intermediates and rRNA ends are incompletely trimmed. Ribosome profiling of Ribo-T cells shows no defects in translation elongation but reveals somewhat higher occupancy by Ribo-T of the start codons and to a lesser extent stop codons, suggesting that subunit tethering mildly affects the initiation and termination stages of translation. Understanding limitations of Ribo-T system offers ways for its future development.


Assuntos
Subunidades Ribossômicas/química , Subunidades Ribossômicas/metabolismo , Códon de Iniciação/genética , Códon de Iniciação/metabolismo , Escherichia coli/química , Escherichia coli/genética , Escherichia coli/metabolismo , Biossíntese de Proteínas , Processamento Pós-Transcricional do RNA , RNA Bacteriano/química , RNA Bacteriano/genética , RNA Bacteriano/metabolismo , RNA Ribossômico 16S/química , RNA Ribossômico 16S/genética , RNA Ribossômico 16S/metabolismo , RNA Ribossômico 23S/química , RNA Ribossômico 23S/genética , RNA Ribossômico 23S/metabolismo , Proteínas Ribossômicas/genética , Proteínas Ribossômicas/metabolismo , Subunidades Ribossômicas/genética
18.
EBioMedicine ; 41: 509-516, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-30796005

RESUMO

BACKGROUND: The therapeutic potential of faecal microbiota transplantation (FMT) is under investigation for a range of inflammatory conditions. While mechanisms of benefit are poorly understood, most models rely on the viability of transplanted microbes. We hypothesised that protocols commonly used in the preparation of faecal transplants will substantially reduce the number, diversity and functional potential of viable microbes. METHODS: Stools from eight screened donors were processed under strict anaerobic conditions, in ambient air, and freeze-thawed. Propidium monoazide (PMA) sample treatment was combined with quantitative PCR, 16S rRNA gene amplicon sequencing and short-chain fatty acid (SCFA) analysis to define the viable microbiota composition and functional potential. FINDINGS: Approximately 50% of bacterial content of stool processed immediately under strict anaerobic conditions was non-viable. Homogenisation in ambient air or freeze-thaw reduced viability to 19% and 23% respectively. Processing of samples in ambient air resulted in up to 12-fold reductions in the abundance of important commensal taxa, including the highly butyrogenic species Faecalibacterium prausnitzii, Subdoligranulum variable, and Eubacterium hallii. The adverse impact of atmospheric oxygen exposure on the capacity of the transplanted microbiota to support SCFA biosynthesis was demonstrated by significantly reduced butyrate and acetate production by faecal slurries processed in ambient air. In contrast, while reducing overall levels of viable bacteria, freeze-thaw did not significantly alter viable microbiota composition. INTERPRETATION: The practice of preparing material for faecal transplantation in ambient air profoundly affects viable microbial content, disproportionately reducing the abundance of anaerobic commensals and the capacity for biosynthesis of important anti-inflammatory metabolites. FUND: This work was supported by the South Australian Health and Medical Research Institute. LP is supported by a scholarship from the Flinders Foundation. GR is supported by a Matthew Flinders Research Fellowship.


Assuntos
Bactérias/metabolismo , Transplante de Microbiota Fecal , Fezes/microbiologia , Acetatos/metabolismo , Bactérias/genética , Bactérias/isolamento & purificação , Proteínas de Bactérias/genética , Butiratos/metabolismo , Coenzima A-Transferases/genética , Ácidos Graxos Voláteis/biossíntese , Congelamento , Microbioma Gastrointestinal , Humanos , Viabilidade Microbiana , RNA Ribossômico 16S/química , RNA Ribossômico 16S/genética , RNA Ribossômico 16S/metabolismo , Reação em Cadeia da Polimerase em Tempo Real , Análise de Sequência de DNA
19.
Nat Biotechnol ; 37(2): 186-192, 2019 02.
Artigo em Inglês | MEDLINE | ID: mdl-30718869

RESUMO

Understanding gut microbiome functions requires cultivated bacteria for experimental validation and reference bacterial genome sequences to interpret metagenome datasets and guide functional analyses. We present the Human Gastrointestinal Bacteria Culture Collection (HBC), a comprehensive set of 737 whole-genome-sequenced bacterial isolates, representing 273 species (105 novel species) from 31 families found in the human gastrointestinal microbiota. The HBC increases the number of bacterial genomes derived from human gastrointestinal microbiota by 37%. The resulting global Human Gastrointestinal Bacteria Genome Collection (HGG) classifies 83% of genera by abundance across 13,490 shotgun-sequenced metagenomic samples, improves taxonomic classification by 61% compared to the Human Microbiome Project (HMP) genome collection and achieves subspecies-level classification for almost 50% of sequences. The improved resource of gastrointestinal bacterial reference sequences circumvents dependence on de novo assembly of metagenomes and enables accurate and cost-effective shotgun metagenomic analyses of human gastrointestinal microbiota.


Assuntos
Genoma Bacteriano , Metagenoma , Metagenômica , Bactérias/classificação , Biologia Computacional/métodos , Mapeamento de Sequências Contíguas , Microbioma Gastrointestinal , Genoma Humano , Humanos , Filogenia , RNA Ribossômico 16S/metabolismo , Análise de Sequência de DNA , Especificidade da Espécie
20.
PLoS One ; 14(1): e0211275, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30689668

RESUMO

3-Methylindole (3MI) or Skatole is a volatile lipophilic organic compound produced by anoxic metabolism of L-tryptophan and associated with animal farming and industrial processing wastes. Pure cultures of bacteria capable of utilizing 3MI were isolated from chicken manure using enrichment culture techniques. The bacteria were identified as Acinetobacter toweneri NTA1-2A and Acinetobacter guillouiae TAT1-6A, based on 16S rDNA gene amplicon sequence data. The optimal temperature and pH for degradation of 3MI were established using single factor experiments. Strain tolerance was assessed over a range of initial concentrations of 3MI, and the effects of initial concentration on subsequent microbial 3MI degradation were also measured. During the degradation experiment, concentrations of 3MI were quantified by reverse-phase high-performance liquid chromatography (HPLC). The strains were capable of degrade initial concentrations of 3MI ranging from 65-200 mg/L. The degradation efficiency was >85% in 6 days for both strains when the initial concentration is less than 200 mg/L. The strains were tested for enzymatic activity using 65 mg/L 3MI. The enzyme extracts of NTA1-2A and TAT1-6A from the 3MI medium degraded 71.46% and 60.71% of 3MI respectively, but no appreciable change in 3MI concentration in the control group was witnessed. Our experiment revealed betaine and choline were identified as 3MI degradation metabolites by both strains while nitroso-pyrrolidine and beta-alaninebetaine formed by NTA1-2A and TAT1-6A strains respectively. The NTA1-2A and TAT1-6A strains removed 84.32% and 81.39% 3MI respectively from chicken manure during fermentation in 8 days and showed a statistically significant difference (P < 0.05) compared with the control group. The optimum temperature and pH were 31°C and 6 respectively, for 3MI degradation by A. toweneri NTA1-2A and A. guillouiae TAT1-6A. We concluded that A. toweneri NTA1-2A and A. guillouiae TAT1-6A are potential strains of interest to degrade 3MI and control odorant in poultry and other livestock industries.


Assuntos
Acinetobacter/metabolismo , Escatol/metabolismo , Acinetobacter/classificação , Acinetobacter/crescimento & desenvolvimento , Acinetobacter/isolamento & purificação , Animais , Galinhas , Cromatografia Líquida de Alta Pressão , Fezes/microbiologia , Concentração de Íons de Hidrogênio , Filogenia , RNA Ribossômico 16S/química , RNA Ribossômico 16S/metabolismo , Escatol/análise , Temperatura Ambiente
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