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Endocrinology Oct 2017Recently, the gastrointestinal microbiome, and its metabolites, has emerged as a potential regulator of host metabolism. However, to date little is known on the precise...
Recently, the gastrointestinal microbiome, and its metabolites, has emerged as a potential regulator of host metabolism. However, to date little is known on the precise mechanisms of how this regulation occurs. Hydrogen sulfide (H2S) is abundantly produced in the colon by sulfate-reducing bacteria (SRB). H2S is a bioactive gas that plays regulatory roles in many systems, including metabolic hormone regulation. This gas metabolite is produced in close proximity to the glucagonlike peptide-1 (GLP-1)-secreting cells in the gut epithelium. GLP-1 is a peptide hormone that plays pivotal roles in both glucose homeostasis and appetite regulation. We hypothesized that H2S can directly regulate GLP-1 secretion. We demonstrated that H2S donors (NaHS and GYY4137) directly stimulate GLP-1 secretion in murine L-cells (GLUTag) and that this occurs through p38 mitogen-activated protein kinase without affecting cell viability. We then increased SRB in mice by supplementing the diet with a prebiotic chondroitin sulfate for 4 weeks. Mice treated with chondroitin sulfate had elevated Desulfovibrio piger levels in the feces and increased colonic and fecal H2S concentration. These animals also had enhanced GLP-1 and insulin secretion, improved oral glucose tolerance, and reduced food consumption. These results indicate that H2S plays a stimulatory role in GLP-1 secretion and that sulfate prebiotics can enhance GLP-1 release and its downstream metabolic actions.
Topics: Animals; Blotting, Western; Chondroitin Sulfates; Colon; DNA, Bacterial; Desulfovibrio; Eating; Feces; Gastrointestinal Microbiome; Glucagon-Like Peptide 1; Glucose Tolerance Test; Hydrogen Sulfide; Insulin; Insulin Secretion; Intestinal Mucosa; Male; Mice; Morpholines; Organothiophosphorus Compounds; Prebiotics; Real-Time Polymerase Chain Reaction; Sulfides
PubMed: 28977605
DOI: 10.1210/en.2017-00391 -
Scientific Reports Sep 2017The aetiology of colic, a functional gastrointestinal disorder in infants, is not yet resolved. Different mechanisms have been suggested involving the gut microbiota and...
The aetiology of colic, a functional gastrointestinal disorder in infants, is not yet resolved. Different mechanisms have been suggested involving the gut microbiota and intermediate metabolites such as lactate. Lactate can be metabolized by lactate-utilizing bacteria (LUB) to form different end-products. Using a functional approach, we hypothesized that H production and accumulation by LUB is associated with the development of colic. The LUB communities in the feces of forty infants, including eight colicky infants, were characterized using a combination of culture- and molecular-based methods, and metabolite concentrations were measured by HPLC. Interactions among LUB strains isolated from feces were investigated with pure and mixed cultures using anaerobic techniques. We emphasized high prevalence of crying, flatulence, colic and positive correlations thereof in the first 3 months of life. Crying infants showed significantly higher ratio of LUB non-sulfate-reducing bacteria (LUB non-SRB) (H-producer), to LUB SRB (H-utilizer) at 3 months. Colicky infants had significantly higher number of H-producing Eubacterium hallii at 2 weeks compared to non-colicky infants. We revealed the function of Desulfovibrio piger and Eubacterium limosum to reduce H accumulation in co-cultures with H-producing Veillonella ratti. Our data suggest that the balance between H-producing and H-utilizing LUB might contribute to colic symptoms.
Topics: Bacteria; Chromatography, High Pressure Liquid; Colic; Dysbiosis; Feces; Female; Gastrointestinal Microbiome; Humans; Hydrogen; Infant; Infant, Newborn; Lactic Acid; Male; Metabolome
PubMed: 28894218
DOI: 10.1038/s41598-017-11509-1 -
Veterinary Microbiology Jun 2017Despite the recent global increase in fatal endemic outbreaks of proliferative enteropathy (PE) caused by the obligate intracellular bacterium Lawsonia intracelluralis...
Despite the recent global increase in fatal endemic outbreaks of proliferative enteropathy (PE) caused by the obligate intracellular bacterium Lawsonia intracelluralis (LI) in the swine industry, development of effective prevention strategies or immunodiagnostic tests has been delayed due to the difficulty of cultivating this pathogen in vitro. Although several genetic analyses have been performed at the level of gene transcription after the complete genome sequence of LI was made available, the mechanism of LI infection and virulence genes remain unidentified. In the present study, we assessed the antigenic features of the LI0004 protein, which we putatively defined as Lawsonia hemolysin A (LhlyA), by employing bioinformatics tools and in vivo and in vitro protein-based molecular assays. The amino acid sequence of LhlyA showed approximately 60% homology to the hemolysin-like proteins of Bilophila wadsworthia and Desulfovibrio piger. Presence of computationally predicted linear antigenic B-cell epitopes on the LhlyA protein was demonstrated by immunoblotting; a band with a molecular mass corresponding to the predicted size of the protein was strongly recognized by sera collected from artificially infected mice. Further, in an in vivo cytotoxicity assay, no splenomegaly was observed in mice inoculated with purified LhlyA. Collectively, the data presented here suggest that the LhlyA protein is a highly immuno-reactive antigen of L. intracellullaris and can potentially be used to develop effective protection strategies against PE.
Topics: Amino Acid Sequence; Animals; Antibodies, Bacterial; Antigens, Bacterial; Desulfovibrionaceae Infections; Epitopes, B-Lymphocyte; Female; Hemolysin Proteins; Lawsonia Bacteria; Mice; Mice, Inbred BALB C; Sequence Alignment; Specific Pathogen-Free Organisms; Swine; Swine Diseases
PubMed: 28622862
DOI: 10.1016/j.vetmic.2017.05.007 -
Genome Announcements Feb 2017The complete genome sequence of FI11049 was determined. The genome consists of a single circular chromosome of 2,807,531 bp encoding seven rRNA operons, 76 tRNA genes,...
The complete genome sequence of FI11049 was determined. The genome consists of a single circular chromosome of 2,807,531 bp encoding seven rRNA operons, 76 tRNA genes, and 2,535 coding genes.
PubMed: 28209813
DOI: 10.1128/genomeA.01528-16 -
BMC Bioinformatics Sep 2016The explosive growth of microbiome research has yielded great quantities of data. These data provide us with many answers, but raise just as many questions. 16S rDNA-the...
BACKGROUND
The explosive growth of microbiome research has yielded great quantities of data. These data provide us with many answers, but raise just as many questions. 16S rDNA-the backbone of microbiome analyses-allows us to assess α-diversity, β-diversity, and microbe-microbe associations, which characterize the overall properties of an ecosystem. However, we are still unable to use 16S rDNA data to directly assess the microbe-microbe and microbe-environment interactions that determine the broader ecology of that system. Thus, properties such as competition, cooperation, and nutrient conditions remain insufficiently analyzed. Here, we apply predictive community metabolic models of microbes identified with 16S rDNA data to probe the ecology of microbial communities.
RESULTS
We developed a methodology for the large-scale assessment of microbial metabolic interactions (MMinte) from 16S rDNA data. MMinte assesses the relative growth rates of interacting pairs of organisms within a community metabolic network and whether that interaction has a positive or negative effect. Moreover, MMinte's simulations take into account the nutritional environment, which plays a strong role in determining the metabolism of individual microbes. We present two case studies that demonstrate the utility of this software. In the first, we show how diet influences the nature of the microbe-microbe interactions. In the second, we use MMinte's modular feature set to better understand how the growth of Desulfovibrio piger is affected by, and affects the growth of, other members in a simplified gut community under metabolic conditions suggested to be determinant for their dynamics.
CONCLUSION
By applying metabolic models to commonly available sequence data, MMinte grants the user insight into the metabolic relationships between microbes, highlighting important features that may relate to ecological stability, susceptibility, and cross-feeding. These relationships are at the foundation of a wide range of ecological questions that impact our ability to understand problems such as microbially-derived toxicity in colon cancer.
Topics: Bacteria; Metabolic Networks and Pathways; Metabolism; Microbiota; Models, Biological; Software; Species Specificity
PubMed: 27590448
DOI: 10.1186/s12859-016-1230-3 -
Neuro Endocrinology Letters 2015The aim of our work was to evaluate effect of selected salicylamides on cell viability of sulfate-reducing bacterium Desulfovibrio piger Vib-7 isolated from the human...
OBJECTIVES
The aim of our work was to evaluate effect of selected salicylamides on cell viability of sulfate-reducing bacterium Desulfovibrio piger Vib-7 isolated from the human large intestine, as well as to assess antimicrobial activity and biological properties of these compounds.
METHODS
Microbiological, biochemical, biophysical methods, and statistical processing of the results were used.
RESULTS
An antimicrobial activity and biological properties of salicylamides against intestinal sulfate-reducing bacteria was studied. Primary in vitro screening of the synthesized selected salicylamides was performed against D. piger Vib-7. Adding 0.37-1.10 µmol.L(-1) (N-(4-bromophenyl)-5-chloro-2-hydroxybenzamide, 5-chloro-2-hydroxy-N-[4-(trifluoromethyl)phenyl]benzamide, 5-chloro-N-(3,4-dichlorophenyl)-2-hydroxybenzamide, 5-chloro-2-hydroxy-N-(4-nitrophenyl)benzamide and 4-chloro-N-(3,4-dichlorophenyl)-2-hydroxybenzamide) caused decrease in biomass accumulation by 8-53, 64-66, 49-50, 82-90, 43-46% compared to control, respectively. The studied compounds completely inhibited the growth of D. piger Vib-7 under the effect of 30 µmol.L(-1). Moreover, addition of the compounds in the culture medium inhibited the process of dissimilation sulfate dose dependently. Treatment with salicylamides led to the bacterial growth inhibition which correlated with the level of inhibition of sulfate reduction. The data on relative survival of D. piger Vib-7 cells and cytotoxicity of salicylamides are consistent to our research in previous series of the biomass accumulation experiments.
CONCLUSIONS
A significant cytotoxic activity under the influence of salicylamides was determined. These results are consistent with a data on bacterial growth and inhibition process of dissimilation sulfate. The strongest cytotoxic effect of the derivatives was observed in compounds of 5-chloro-2-hydroxy-N-[4-(trifluoromethyl)phenyl]benzamide and 5-chloro-2-hydroxy-N-(4-nitrophenyl)benzamide which showed low survival and high toxicity rates.
Topics: Desulfovibrio; Humans; Intestine, Large; Microbial Sensitivity Tests; Microbial Viability; Salicylamides
PubMed: 26757109
DOI: No ID Found -
The Open Microbiology Journal 2015The objective of this study was to design a model of dissimilatory sulfate reduction process using the Verhulst function, with a particular focus on the kinetics of...
Model-based Characterization of the Parameters of Dissimilatory Sulfate Reduction Under the Effect of Different Initial Density of Desulfovibrio piger Vib-7 Bacterial Cells.
The objective of this study was to design a model of dissimilatory sulfate reduction process using the Verhulst function, with a particular focus on the kinetics of bacterial growth, sulfate and lactate consumption, and accumulation of hydrogen sulfide and acetate. The effect of the initial density (0.12±0.011, 0.25±0.024, 0.5±0.048 and 1.0±0.096 mg cells/ml of medium) of the sulfate-reducing bacteria Desulfovibrio piger Vib-7 on the growth and dissimilatory sulfate reduction was studied. The exponential growth phase of the D. piger Vib-7 was observed for 72 hours of cultivation at the (0.12 and 0.25 mg/ml) initial concentration of bacterial cells. Sulfate and lactate were consumed incompletely during this time. The increase in the initial concentration of cells to 0.5 and 1 mg/ml led to a shortening of the exponential bacterial growth phase and a shift to the stationary phase of the growth. In the case of 0.5 mg/ml seeding, the stationary growth phase was observed in the 36(th) hour of cultivation. The increase in the initial concentration of cells to 1 mg/ml led to the beginning of the stationary growth phase in 24th hours of cultivation. Under these conditions, sulfate and lactate were consumed completely in the 48th hour of cultivation. The kinetic analysis of the curves of bacterial growth and the process of dissimilatory sulfate reduction by D. piger Vib-7 was carried out.
PubMed: 26668663
DOI: 10.2174/1874285801509010055 -
Polish Journal of Microbiology 2015Intestinal sulfate-reducing bacteria reduce sulfate ions to hydrogen sulfide causing inflammatory bowel diseases of humans and animals. The bacteria consume lactate as...
Intestinal sulfate-reducing bacteria reduce sulfate ions to hydrogen sulfide causing inflammatory bowel diseases of humans and animals. The bacteria consume lactate as electron donor which is oxidized to acetate via pyruvate in process of the dissimilatory sulfate reduction. Pyruvate-ferredoxin oxidoreductase activity and the kinetic properties of the enzyme from intestinal sulfate-reducing bacteria Desulfovibrio piger and Desulfomicrobium sp. have never been well-characterized and have not been yet studied. In this paper we present for the first time the specific activity of pyruvate-ferredoxin oxidoreductase and the kinetic properties of the enzyme in cell-free extracts of both D. piger Vib-7 and Desulfomicrobium sp. Rod-9 intestinal bacterial strains. Microbiological, biochemical, biophysical and statistical methods were used in this work. The optimal temperature (+35°C) and pH 8.5 for enzyme reaction were determined. The spectral analysis of the puri- fied pyruvate-ferredoxin oxidoreductase from the cell-free extracts was demonstrated. Analysis of the kinetic properties of the studied enzyme was carried out. Initial (instantaneous) reaction velocity (V0), maximum amount of the product of reaction (Pmax), the reaction time (half saturation period) and maximum velocity of the pyruvate-ferredoxin oxidoreductase reaction (V ) were defined. Michaelis constants (Km) of the enzyme reaction were calculated for both intestinal bacterial strains. The studies of the kinetic enzyme properties in the intestinal sulfate-reducing bacteria strains in detail can be prospects for clarifying the etiological role of these bacteria in the development of inflammatory bowel diseases.
Topics: Deltaproteobacteria; Desulfovibrio; Gene Expression Regulation, Bacterial; Gene Expression Regulation, Enzymologic; Hydrogen-Ion Concentration; Kinetics; Pyruvate Synthase; Temperature
PubMed: 26373169
DOI: No ID Found -
Ukrainian Biochemical Journal 2014The investigation of specific activity of ATP sulfurylase and kinetic properties of the enzyme in cell-free extracts of intestinal bacterial strains Desulfovibrio piger...
The investigation of specific activity of ATP sulfurylase and kinetic properties of the enzyme in cell-free extracts of intestinal bacterial strains Desulfovibrio piger Vib-7 and Desulfomicrobium sp. Rod-9 is presented. The microbiological, biochemical, biophysical and statistical methods were used in the work. The optimal temperature (35°C) and pH 8.0-8.5 for enzyme reaction were determined. An analysis of kinetic properties of ATP sulfurylase has been carried out. Initial (instantaneous) reaction velocity (V0), maximum amount of the product of reaction (Pmax), the reaction time (half saturation period, τ) and maximum velocity of the ATP sulfurylase reaction (Vmax) have been defined. Michaelis constants (Km(Sulfate), Km(ATP), Km(APS), and Km(Pyrophosphate)) of the enzyme reaction were demonstrated for both D. piger Vib-7 and Desulfomicrobium sp. Rod-9 intestinal bacterial strains.
Topics: Adenosine Triphosphate; Bacterial Proteins; Desulfovibrio; Diphosphates; Enzyme Assays; Humans; Hydrogen-Ion Concentration; Intestine, Large; Kinetics; Subcellular Fractions; Substrate Specificity; Sulfate Adenylyltransferase; Sulfates; Sulfur-Reducing Bacteria; Temperature
PubMed: 25816613
DOI: 10.15407/ubj86.06.129 -
Acta Biochimica Polonica 2015Phosphotransacetylase activity and the kinetic properties of the enzyme from intestinal sulfate-reducing bacteria Desulfovibrio piger and Desulfomicrobium sp. has never...
Phosphotransacetylase activity and the kinetic properties of the enzyme from intestinal sulfate-reducing bacteria Desulfovibrio piger and Desulfomicrobium sp. has never been well-characterized and has not been studied yet. In this paper, the specific activity of phosphotransacetylase and the kinetic properties of the enzyme in cell-free extracts of both D. piger Vib-7 and Desulfomicrobium sp. Rod-9 intestinal bacterial strains were presented at the first time. The microbiological, biochemical, biophysical and statistical methods in this work were used. The optimal temperature and pH for enzyme reaction was determined. Analysis of the kinetic properties of the studied enzyme was carried out. Initial (instantaneous) reaction velocity (V0), maximum amount of the product of reaction (Pmax), the reaction time (half saturation period, τ) and maximum velocity of the phosphotransacetylase reaction (Vmax) were defined. Michaelis constants (Km) of the enzyme reaction (3.36 ± 0.35 mM for D. piger Vib-7, 5.97 ± 0.62 mM for Desulfomicrobium sp. Rod-9) were calculated. The studies of the phosphotransacetylase in the process of dissimilatory sulfate reduction and kinetic properties of this enzyme in intestinal sulfate-reducing bacteria, their production of acetate in detail can be perspective for clarification of their etiological role in the development of the humans and animals bowel diseases. These studies might help in predicting the development of diseases of the gastrointestinal tract, by providing further details on the etiology of bowel diseases which are very important for the clinical diagnosis of these disease types.
Topics: Bacteria; Hydrogen-Ion Concentration; Intestines; Kinetics; Oxidation-Reduction; Phosphate Acetyltransferase; Sulfates; Temperature
PubMed: 25781158
DOI: 10.18388/abp.2014_845