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Sample records for reducing bacterial enrichment

  1. Stable Isotopic Studies of n-Alkane Metabolism by a Sulfate-Reducing Bacterial Enrichment Culture

    PubMed Central

    Davidova, Irene A.; Gieg, Lisa M.; Nanny, Mark; Kropp, Kevin G.; Suflita, Joseph M.

    2005-01-01

    Gas chromatography-mass spectrometry and nuclear magnetic resonance spectroscopy were used to study the metabolism of deuterated n-alkanes (C6 to C12) and 1-13C-labeled n-hexane by a highly enriched sulfate-reducing bacterial culture. All substrates were activated via fumarate addition to form the corresponding alkylsuccinic acid derivatives as transient metabolites. Formation of d14-hexylsuccinic acid in cell extracts from exogenously added, fully deuterated n-hexane confirmed that this reaction was the initial step in anaerobic alkane metabolism. Analysis of resting cell suspensions amended with 1-13C-labeled n-hexane confirmed that addition of the fumarate occurred at the C-2 carbon of the parent substrate. Subsequent metabolism of hexylsuccinic acid resulted in the formation of 4-methyloctanoic acid, and 3-hydroxy-4-methyloctanoic acid was tentatively identified. We also found that 13C nuclei from 1-13C-labeled n-hexane became incorporated into the succinyl portion of the initial metabolite in a manner that indicated that 13C-labeled fumarate was formed and recycled during alkane metabolism. Collectively, the findings obtained with a sulfate-reducing culture using isotopically labeled alkanes augment and support the previously proposed pathway (H. Wilkes, R. Rabus, T. Fischer, A. Armstroff, A. Behrends, and F. Widdel, Arch. Microbiol. 177:235-243, 2002) for metabolism of deuterated n-hexane by a denitrifying bacterium. PMID:16332800

  2. Stable isotopic studies of n-alkane metabolism by a sulfate-reducing bacterial enrichment culture.

    PubMed

    Davidova, Irene A; Gieg, Lisa M; Nanny, Mark; Kropp, Kevin G; Suflita, Joseph M

    2005-12-01

    Gas chromatography-mass spectrometry and nuclear magnetic resonance spectroscopy were used to study the metabolism of deuterated n-alkanes (C6 to C12) and 1-13C-labeled n-hexane by a highly enriched sulfate-reducing bacterial culture. All substrates were activated via fumarate addition to form the corresponding alkylsuccinic acid derivatives as transient metabolites. Formation of d14-hexylsuccinic acid in cell extracts from exogenously added, fully deuterated n-hexane confirmed that this reaction was the initial step in anaerobic alkane metabolism. Analysis of resting cell suspensions amended with 1-13C-labeled n-hexane confirmed that addition of the fumarate occurred at the C-2 carbon of the parent substrate. Subsequent metabolism of hexylsuccinic acid resulted in the formation of 4-methyloctanoic acid, and 3-hydroxy-4-methyloctanoic acid was tentatively identified. We also found that 13C nuclei from 1-13C-labeled n-hexane became incorporated into the succinyl portion of the initial metabolite in a manner that indicated that 13C-labeled fumarate was formed and recycled during alkane metabolism. Collectively, the findings obtained with a sulfate-reducing culture using isotopically labeled alkanes augment and support the previously proposed pathway (H. Wilkes, R. Rabus, T. Fischer, A. Armstroff, A. Behrends, and F. Widdel, Arch. Microbiol. 177:235-243, 2002) for metabolism of deuterated n-hexane by a denitrifying bacterium.

  3. Biodegradation of munitions compounds by a sulfate reducing bacterial enrichment culture

    SciTech Connect

    Boopathy, R.; Manning, J.

    1997-08-01

    The degradation of several munitions compounds was studied. The compounds included 2,4,6-trinitrotoluene (TNT), hexahydro-1,3,5-trinitro-1,3,5-triazine, octahydro-1,3,5,7-tetranitro-1,3,5,7-tetraazocine, 2,4,6-trinitrobenzene (TNB), and 2,4-dinitrotoluene. All of the compounds studied were degraded by the sulfate reducing bacterial (SRB) enrichment culture. The SRB culture did not use the munitions compounds as their sole source of carbon. However, all the munitions compounds tested served as the sole source of nitrogen for the SRB culture. Degradation of munitions compounds was achieved by a co-metabolic process. The SRB culture used a variety of carbon sources including pyruvate, ethanol, formate, lactate, and H{sub 2}-CO{sub 2}. The SRB culture was an incomplete oxidizer, unable to carry out the terminal oxidation of organic substrates to CO{sub 2} as the sole product, and it did not use acetate or methanol as a carbon source. In addition to serving as nitrogen sources, the munitions compounds also served as electron acceptors in the absence of sulfate. A soil slurry experiment with 5% and 10% munitions compounds-contaminated soil showed that the contaminant TNT was metabolized by the SRB culture in the presence of pyruvate as electron donor. This culture may be useful in decontaminating munitions compounds-contaminated soil and water under anaerobic conditions.

  4. Enriched Iron(III)-Reducing Bacterial Communities are Shaped by Carbon Substrate and Iron Oxide Mineralogy.

    PubMed

    Lentini, Christopher J; Wankel, Scott D; Hansel, Colleen M

    2012-01-01

    Iron (Fe) oxides exist in a spectrum of structures in the environment, with ferrihydrite widely considered the most bioavailable phase. Yet, ferrihydrite is unstable and rapidly transforms to more crystalline Fe(III) oxides (e.g., goethite, hematite), which are poorly reduced by model dissimilatory Fe(III)-reducing microorganisms. This begs the question, what processes and microbial groups are responsible for reduction of crystalline Fe(III) oxides within sedimentary environments? Further, how do changes in Fe mineralogy shape oxide-hosted microbial populations? To address these questions, we conducted a large-scale cultivation effort using various Fe(III) oxides (ferrihydrite, goethite, hematite) and carbon substrates (glucose, lactate, acetate) along a dilution gradient to enrich for microbial populations capable of reducing Fe oxides spanning a wide range of crystallinities and reduction potentials. While carbon source was the most important variable shaping community composition within Fe(III)-reducing enrichments, both Fe oxide type and sediment dilution also had a substantial influence. For instance, with acetate as the carbon source, only ferrihydrite enrichments displayed a significant amount of Fe(III) reduction and the well-known dissimilatory metal reducer Geobacter sp. was the dominant organism enriched. In contrast, when glucose and lactate were provided, all three Fe oxides were reduced and reduction coincided with the presence of fermentative (e.g., Enterobacter spp.) and sulfate-reducing bacteria (e.g., Desulfovibrio spp.). Thus, changes in Fe oxide structure and resource availability may shift Fe(III)-reducing communities between dominantly metal-respiring to fermenting and/or sulfate-reducing organisms which are capable of reducing more recalcitrant Fe phases. These findings highlight the need for further targeted investigations into the composition and activity of speciation-directed metal-reducing populations within natural environments.

  5. Enriched Iron(III)-Reducing Bacterial Communities are Shaped by Carbon Substrate and Iron Oxide Mineralogy

    PubMed Central

    Lentini, Christopher J.; Wankel, Scott D.; Hansel, Colleen M.

    2012-01-01

    Iron (Fe) oxides exist in a spectrum of structures in the environment, with ferrihydrite widely considered the most bioavailable phase. Yet, ferrihydrite is unstable and rapidly transforms to more crystalline Fe(III) oxides (e.g., goethite, hematite), which are poorly reduced by model dissimilatory Fe(III)-reducing microorganisms. This begs the question, what processes and microbial groups are responsible for reduction of crystalline Fe(III) oxides within sedimentary environments? Further, how do changes in Fe mineralogy shape oxide-hosted microbial populations? To address these questions, we conducted a large-scale cultivation effort using various Fe(III) oxides (ferrihydrite, goethite, hematite) and carbon substrates (glucose, lactate, acetate) along a dilution gradient to enrich for microbial populations capable of reducing Fe oxides spanning a wide range of crystallinities and reduction potentials. While carbon source was the most important variable shaping community composition within Fe(III)-reducing enrichments, both Fe oxide type and sediment dilution also had a substantial influence. For instance, with acetate as the carbon source, only ferrihydrite enrichments displayed a significant amount of Fe(III) reduction and the well-known dissimilatory metal reducer Geobacter sp. was the dominant organism enriched. In contrast, when glucose and lactate were provided, all three Fe oxides were reduced and reduction coincided with the presence of fermentative (e.g., Enterobacter spp.) and sulfate-reducing bacteria (e.g., Desulfovibrio spp.). Thus, changes in Fe oxide structure and resource availability may shift Fe(III)-reducing communities between dominantly metal-respiring to fermenting and/or sulfate-reducing organisms which are capable of reducing more recalcitrant Fe phases. These findings highlight the need for further targeted investigations into the composition and activity of speciation-directed metal-reducing populations within natural environments. PMID

  6. THE ANAEROBIC BIODEGRADATION OF O-,M- AND P-CRESOL BY SULFATE-REDUCING BACTERIAL ENRICHMENT CULTURES OBTAINED FROM A SHALLOW ANOXIC AQUIFER

    EPA Science Inventory

    Sulfate-reducing bacterial enrichments were obtained from a shallow anoxic aquifer for their ability to metabolize either o-, m-, orp-cresol. GC/MS and simultaneous adaptation experiments suggested that the anaerobic decomposition of p-cresol proceeds ...

  7. THE ANAEROBIC BIODEGRADATION OF O-,M- AND P-CRESOL BY SULFATE-REDUCING BACTERIAL ENRICHMENT CULTURES OBTAINED FROM A SHALLOW ANOXIC AQUIFER

    EPA Science Inventory

    Sulfate-reducing bacterial enrichments were obtained from a shallow anoxic aquifer for their ability to metabolize either o-, m-, orp-cresol. GC/MS and simultaneous adaptation experiments suggested that the anaerobic decomposition of p-cresol proceeds ...

  8. Comparison of Sulphate-reducing Bacterial Communities in Japanese Fish Farm Sediments with Different Levels of Organic Enrichment

    PubMed Central

    Kondo, Ryuji; Mori, Yumi; Sakami, Tomoko

    2012-01-01

    Fish farm sediments receive a large amount of organic matter from uneaten food and fecal material. This nutrient enrichment, or organic pollution, causes the accumulation of sulphide in the sediment from the action of sulphate-reducing bacteria (SRB). We investigated the effect of organic enrichment around coastal fish farms comparing the SRB community structure in these sediments. Sediment samples with different levels of organic pollution classified based upon the contents of acid-volatile sulphide and chemical oxygen demand were collected at three stations on the coast of western Japan. The SRB community composition was assessed using PCR amplification, cloning, sequencing and phylogenetic analysis of the dissimilatory sulphite reductase β-subunit gene (dsrB) fragments using directly extracted sediment DNA. Sequencing of the cloned PCR products of dsrB showed the existence of different SRB groups in the sediments. The majority of dsrB sequences were associated with the families Desulfobacteraceae and Desulfobulbaceae. Clones related to the phylum Firmicutes were also detected from all sediment samples. Statistical comparison of sequences revealed that community compositions of SRB from polluted sediments significantly differed from those of moderately polluted sediments and unpolluted sediments (LIBSHUFF, p<0.05), showing a different distribution of SRB in the fish farm sediments. There is evidence showing that the organic enrichment of sediments influences the composition of SRB communities in sediments at marine fish farms. PMID:22791053

  9. Enzymes are enriched in bacterial essential genes.

    PubMed

    Gao, Feng; Zhang, Randy Ren

    2011-01-01

    Essential genes, those indispensable for the survival of an organism, play a key role in the emerging field, synthetic biology. Characterization of functions encoded by essential genes not only has important practical implications, such as in identifying antibiotic drug targets, but can also enhance our understanding of basic biology, such as functions needed to support cellular life. Enzymes are critical for almost all cellular activities. However, essential genes have not been systematically examined from the aspect of enzymes and the chemical reactions that they catalyze. Here, by comprehensively analyzing essential genes in 14 bacterial genomes in which large-scale gene essentiality screens have been performed, we found that enzymes are enriched in essential genes. Essential enzymes have overrepresented ligases (especially those forming carbon-oxygen bonds and carbon-nitrogen bonds), nucleotidyltransferases and phosphotransferases, while have underrepresented oxidoreductases. Furthermore, essential enzymes tend to associate with more gene ontology domains. These results, from the aspect of chemical reactions, provide further insights into the understanding of functions needed to support natural cellular life, as well as synthetic cells, and provide additional parameters that can be integrated into gene essentiality prediction algorithms.

  10. Effects of the antimicrobial sulfamethoxazole on groundwater bacterial enrichment

    USGS Publications Warehouse

    Underwood, J.C.; Harvey, R.W.; Metge, D.W.; Repert, D.A.; Baumgartner, L.K.; Smith, R.L.; Roane, T.M.; Barber, L.B.

    2011-01-01

    The effects of "trace" (environmentally relevant) concentrations of the antimicrobial agent sulfamethoxazole (SMX) on the growth, nitrate reduction activity, and bacterial composition of an enrichment culture prepared with groundwater from a pristine zone of a sandy drinking-water aquifer on Cape Cod, MA, were assessed by laboratory incubations. When the enrichments were grown under heterotrophic denitrifying conditions and exposed to SMX, noticeable differences from the control (no SMX) were observed. Exposure to SMX in concentrations as low as 0.005 ??M delayed the initiation of cell growth by up to 1 day and decreased nitrate reduction potential (total amount of nitrate reduced after 19 days) by 47% (p = 0.02). Exposure to 1 ??M SMX, a concentration below those prescribed for clinical applications but higher than concentrations typically detected in aqueous environments, resulted in additional inhibitions: reduced growth rates (p = 5 ?? 10-6), lower nitrate reduction rate potentials (p = 0.01), and decreased overall representation of 16S rRNA gene sequences belonging to the genus Pseudomonas. The reduced abundance of Pseudomonas sequences in the libraries was replaced by sequences representing the genus Variovorax. Results of these growth and nitrate reduction experiments collectively suggest that subtherapeutic concentrations of SMX altered the composition of the enriched nitrate-reducing microcosms and inhibited nitrate reduction capabilities. ?? 2011 American Chemical Society.

  11. Effects of the antimicrobial sulfamethoxazole on groundwater bacterial enrichment

    USGS Publications Warehouse

    Underwood, Jennifer C.; Harvey, Ronald W.; Metge, David W.; Repert, Deborah A.; Baumgartner, Laura K.; Smith, Richard L.; Roane, Timberly M.; Barber, Larry B.

    2011-01-01

    The effects of “trace” (environmentally relevant) concentrations of the antimicrobial agent sulfamethoxazole (SMX) on the growth, nitrate reduction activity, and bacterial composition of an enrichment culture prepared with groundwater from a pristine zone of a sandy drinking-water aquifer on Cape Cod, MA, were assessed by laboratory incubations. When the enrichments were grown under heterotrophic denitrifying conditions and exposed to SMX, noticeable differences from the control (no SMX) were observed. Exposure to SMX in concentrations as low as 0.005 μM delayed the initiation of cell growth by up to 1 day and decreased nitrate reduction potential (total amount of nitrate reduced after 19 days) by 47% (p = 0.02). Exposure to 1 μM SMX, a concentration below those prescribed for clinical applications but higher than concentrations typically detected in aqueous environments, resulted in additional inhibitions: reduced growth rates (p = 5 × 10−6), lower nitrate reduction rate potentials (p = 0.01), and decreased overall representation of 16S rRNA gene sequences belonging to the genus Pseudomonas. The reduced abundance of Pseudomonas sequences in the libraries was replaced by sequences representing the genus Variovorax. Results of these growth and nitrate reduction experiments collectively suggest that subtherapeutic concentrations of SMX altered the composition of the enriched nitrate-reducing microcosms and inhibited nitrate reduction capabilities.

  12. Bacterial production in subarctic peatland lakes enriched by thawing permafrost

    NASA Astrophysics Data System (ADS)

    Deshpande, Bethany N.; Crevecoeur, Sophie; Matveev, Alex; Vincent, Warwick F.

    2016-08-01

    feature of all of the northern lakes sampled, including other thaw lakes and shallow rock-basin lakes (average ± SE of 25 ± 6 %). However, a distinguishing feature of the peatland thaw lakes was significantly higher bacterial specific growth rates, which averaged 4 to 7 times higher values than in the other lake types. The in situ enrichment experiment showed no difference between organic carbon or phosphorus enrichment treatments at day 5 relative to the control, however there was an apparent increase in bacterial growth rates between days 1 and 5 in the soil and the carbon plus phosphorus enrichments. Collectively these results indicate that particles, nutrients and carbon are released by degrading permafrost peatland soils into their associated thermokarst lakes, creating favorable conditions for production by particle-based as well as free-living aquatic bacterial communities. The reduced bacterial concentrations despite high cellular growth rates imply that there is control of their population size by loss-related factors such as grazing and viral lysis.

  13. Substrate versatility of polyhydroxyalkanoate producing glycerol grown bacterial enrichment culture.

    PubMed

    Moralejo-Gárate, Helena; Kleerebezem, Robbert; Mosquera-Corral, Anuska; Campos, José Luis; Palmeiro-Sánchez, Tania; van Loosdrecht, Mark C M

    2014-12-01

    Waste-based polyhydroxyalkanoate (PHA) production by bacterial enrichments generally follows a three step strategy in which first the wastewater is converted into a volatile fatty acid rich stream that is subsequently used as substrate in a selector and biopolymer production units. In this work, a bacterial community with high biopolymer production capacity was enriched using glycerol, a non-fermented substrate. The substrate versatility and PHA production capacity of this community was studied using glucose, lactate, acetate and xylitol as substrate. Except for xylitol, very high PHA producing capacities were obtained. The PHA accumulation was comparable or even higher than with glycerol as substrate. This is the first study that established a high PHA content (≈70 wt%) with glucose as substrate in a microbial enrichment culture. The results presented in this study support the development of replacing pure culture based PHA production by bacterial enrichment cultures. A process where mixtures of substrates can be easily handled and the acidification step can potentially be avoided is described.

  14. Bacteriophages may bias outcome of bacterial enrichment cultures.

    PubMed

    Muniesa, Maite; Blanch, Anicet R; Lucena, Francisco; Jofre, Juan

    2005-08-01

    Enrichment cultures are widely used for the isolation of bacteria in clinical, biotechnological, and environmental studies. However, competition, relative growth rates, or inhibitory effects may alter the outcome of enrichment cultures, causing the phenomenon known as enrichment bias. Bacteriophages are a major component in many microbial systems, and it abounds in natural settings. This abundance means that bacteriophages are likely to be present in many laboratory enrichment cultures. Our hypothesis was that bacteriophages present in the sample might bias the enriched subpopulation, since it can infect and lyse the target bacteria during the enrichment step once the bacteria reach a given density. Here we show that the presence of bacteriophages in Salmonella and Shigella enrichment cultures produced a significant reduction (more than 1 log unit) in the number of these bacteria compared with samples in which bacteriophages had been reduced by filtration through 0.45-microm non-protein-binding membranes. Furthermore, our data indicate that the Salmonella biotypes isolated after the enrichment culture change if bacteriophages are present, thus distorting the results of the analysis.

  15. Bacteriophages May Bias Outcome of Bacterial Enrichment Cultures

    PubMed Central

    Muniesa, Maite; Blanch, Anicet R.; Lucena, Francisco; Jofre, Juan

    2005-01-01

    Enrichment cultures are widely used for the isolation of bacteria in clinical, biotechnological, and environmental studies. However, competition, relative growth rates, or inhibitory effects may alter the outcome of enrichment cultures, causing the phenomenon known as enrichment bias. Bacteriophages are a major component in many microbial systems, and it abounds in natural settings. This abundance means that bacteriophages are likely to be present in many laboratory enrichment cultures. Our hypothesis was that bacteriophages present in the sample might bias the enriched subpopulation, since it can infect and lyse the target bacteria during the enrichment step once the bacteria reach a given density. Here we show that the presence of bacteriophages in Salmonella and Shigella enrichment cultures produced a significant reduction (more than 1 log unit) in the number of these bacteria compared with samples in which bacteriophages had been reduced by filtration through 0.45-μm non-protein-binding membranes. Furthermore, our data indicate that the Salmonella biotypes isolated after the enrichment culture change if bacteriophages are present, thus distorting the results of the analysis. PMID:16085813

  16. Effects of Low-Level Deuterium Enrichment on Bacterial Growth

    PubMed Central

    Xie, Xueshu; Zubarev, Roman A.

    2014-01-01

    Using very precise (±0.05%) measurements of the growth parameters for bacteria E. coli grown on minimal media, we aimed to determine the lowest deuterium concentration at which the adverse effects that are prominent at higher enrichments start to become noticeable. Such a threshold was found at 0.5% D, a surprisingly high value, while the ultralow deuterium concentrations (≤0.25% D) showed signs of the opposite trend. Bacterial adaptation for 400 generations in isotopically different environment confirmed preference for ultralow (≤0.25% D) enrichment. This effect appears to be similar to those described in sporadic but multiple earlier reports. Possible explanations include hormesis and isotopic resonance phenomena, with the latter explanation being favored. PMID:25033078

  17. Effects of low-level deuterium enrichment on bacterial growth.

    PubMed

    Xie, Xueshu; Zubarev, Roman A

    2014-01-01

    Using very precise (±0.05%) measurements of the growth parameters for bacteria E. coli grown on minimal media, we aimed to determine the lowest deuterium concentration at which the adverse effects that are prominent at higher enrichments start to become noticeable. Such a threshold was found at 0.5% D, a surprisingly high value, while the ultralow deuterium concentrations (≤0.25% D) showed signs of the opposite trend. Bacterial adaptation for 400 generations in isotopically different environment confirmed preference for ultralow (≤0.25% D) enrichment. This effect appears to be similar to those described in sporadic but multiple earlier reports. Possible explanations include hormesis and isotopic resonance phenomena, with the latter explanation being favored.

  18. Effects of viral enrichment on bacterial production, respiration and growth efficiency

    NASA Astrophysics Data System (ADS)

    Bonilla-Findji, O.; Rochelle-Newall, E.; Weinbauer, M. G.; Gattuso, J.-P.

    2003-04-01

    Viruses are the most common biological agents in the sea. They can influence many ecological processes such as nutrient and carbon cycling, particle size distribution, algal bloom control, species diversity and gene transfer. As they are mainly bacteriophages they not only influence bacterial abundances but also potentially, the bacterial respiration and production, as has been suggested in by Fuhrman’s model in 1992 and a few recent experimental studies. Through their lytic action viruses can influence biogeochemical cycles and so affect the functioning of the whole marine ecosystem. In order to explore this hypothesis and provide some quantitative data we: (1) studied the effects of viruses on bacterial respiration (BR), production (BP) and growth efficiency (BGE) and (2) investigated whether these effects change over time. A viral enrichment experiment was performed in April and May 2002, where the bacterial community isolated from the Bay of Villefranche was exposed to three treatments: Vo (no viral addition), Vm (enrichment of 1-1.5 fold inactivated viruses) and V+ (enrichment of 1-1.5 fold active viruses). No virally induced effects on bacterial metabolism were observed in April but in May after 24 h of incubation, BR was stimulated by ca. 39% in V+ compared to Vo and by 20% relative to Vm. In the presence of active viruses, BP was repressed by ca. 40% compared to Vo and BGE was reduced by 48%. In May, viruses increased the total bacterial carbon demand (17% in V+ compared to Vo, and by 11% relative to Vm). Our results suggest that viruses seem to induce a shift in the specific role of bacterioplankton by reducing the carbon flow to the higher trophic levels and by stimulating the DOM ‡ bacteria ‡ CO2, N, P, Fe pathway.

  19. Enrichment of amino acid-oxidizing, acetate-reducing bacteria.

    PubMed

    Ato, Makoto; Ishii, Masaharu; Igarashi, Yasuo

    2014-08-01

    In anaerobic condition, amino acids are oxidatively deaminated, and decarboxylated, resulting in the production of volatile fatty acids. In this process, excess electrons are produced and their consumption is necessary for the accomplishment of amino acid degradation. In this study, we anaerobically constructed leucine-degrading enrichment cultures from three different environmental samples (compost, excess sludge, and rice field soil) in order to investigate the diversity of electron-consuming reaction coupled to amino acid oxidation. Constructed enrichment cultures oxidized leucine to isovalerate and their activities were strongly dependent on acetate. Analysis of volatile fatty acids (VFAs) profiles and community structure analysis during batch culture of each enrichment indicated that Clostridium cluster I coupled leucine oxidation to acetate reduction in the enrichment from the compost and the rice field soil. In these cases, acetate was reduced to butyrate. On the other hand, Clostridium cluster XIVb coupled leucine oxidation to acetate reduction in the enrichment from the excess sludge. In this case, acetate was reduced to propionate. To our surprise, the enrichment from rice field soil oxidized leucine even in the absence of acetate and produced butyrate. The enrichment would couple leucine oxidation to reductive butyrate synthesis from CO2. The coupling reaction would be achieved based on trophic link between hydrogenotrophic acetogenic bacteria and acetate-reducing bacteria by sequential reduction of CO2 and acetate. Our study suggests anaerobic degradation of amino acids is achieved yet-to-be described reactions.

  20. Dominance of Geobacteraceae in BTX-degrading enrichments from an iron-reducing aquifer.

    PubMed

    Botton, Sabrina; van Harmelen, Marijn; Braster, Martin; Parsons, John R; Röling, Wilfred F M

    2007-10-01

    Microbial community structure was linked to degradation potential in benzene-, toluene- or xylene- (BTX) degrading, iron-reducing enrichments derived from an iron-reducing aquifer polluted with landfill leachate. Enrichments were characterized using 16S rRNA gene-based analysis, targeting of the benzylsuccinate synthase-encoding bssA gene and phospholipid fatty acid (PLFA) profiling in combination with tracking of labelled substrate. 16S rRNA gene analysis indicated the dominance of Geobacteraceae, and one phylotype in particular, in all enrichments inoculated with polluted aquifer material. Upon cultivation, progressively higher degradation rates with a concomitant decrease in species richness occurred in all primary incubations and successive enrichments. Yet, the same Geobacteraceae phylotype remained common and dominant, indicating its involvement in BTX degradation. However, the bssA gene sequences in BTX degrading enrichments differed considerably from those of Geobacter isolates, suggesting that the first steps of toluene, but also benzene and xylene oxidation, are carried out by another member of the enrichments. Therefore, BTX would be synthrophically degraded by a bacterial consortium in which Geobacteraceae utilized intermediate metabolites. PLFA analysis in combination with (13)C-toluene indicated that the enriched Geobacteraceae were assimilating carbon originally present in toluene. Combined with previous studies, this research suggests that Geobacteraceae play a key role in the natural attenuation of each BTX compound in situ.

  1. ENVIRONMENTAL ENRICHMENT REDUCES THE MNEMONIC AND NEURAL BENEFITS OF ESTROGEN

    PubMed Central

    GRESACK, J. E.; FRICK, K. M.

    2006-01-01

    The degree to which memory is enhanced by estrogen replacement in postmenopausal women may depend on environmental factors such as education. The present study utilized an animal model of environmental enrichment to determine whether environmental factors influence the mnemonic and neural response to estrogen. Female mice were raised in standard (SC) or enriched (EC) conditions from weaning until adulthood (7 months). All mice were ovariectomized at 10 weeks, and tested in object recognition and water-escape motivated radial arm maze (WRAM) tasks at 6 months. Each day at the completion of training, mice received injections of 0.1 mg/kg cyclodextrin-encapsulated 17-β-estradiol (E2), 0.2 mg/kg E2, or cyclodextrin vehicle (VEH). At the completion of behavioral testing, hippocampal levels of the presynaptic protein synaptophysin and of brain-derived neurotrophic factor (BDNF) were measured. Enrichment effects were evident in VEH-treated mice; relative to SC-VEH females, EC-VEH females committed fewer working memory errors in the WRAM and exhibited increased hippocampal synaptophysin levels. Estrogen effects depended on environmental conditions. E2 (0.2 mg/kg) improved object memory only in SC females. The same dose improved working memory in SC females, but somewhat impaired working memory in EC females. Furthermore, both doses reduced hippocampal synaptophysin levels in EC, but not SC, females. In contrast, E2 reduced hippocampal BDNF levels in SC, but not EC, females. This study is the first to compare the effects of estrogen on memory and hippocampal function in enriched and non-enriched female mice. The results suggest that: (1) estrogen benefits object and working memory more in mice raised in non-enriched environments than in those raised in enriched environments, and (2) the changes induced by estrogen and/or enrichment may be associated with alterations in hippocampal synaptic plasticity. PMID:15381276

  2. Reduced enrichment for research and test reactors: Proceedings

    SciTech Connect

    Not Available

    1993-07-01

    The 15th annual Reduced Enrichment for Research and Test Reactors (RERTR) international meeting was organized by Ris{o} National Laboratory in cooperation with the International Atomic Energy Agency and Argonne National Laboratory. The topics of the meeting were the following: National Programs, Fuel Fabrication, Licensing Aspects, States of Conversion, Fuel Testing, and Fuel Cycle. Individual papers have been cataloged separately.

  3. A Culture-Independent Approach to Enrich Endophytic Bacterial Cells from Sugarcane Stems for Community Characterization.

    PubMed

    Dos-Santos, Carlos M; de Souza, Daniel G; Balsanelli, Eduardo; Cruz, Leonardo Magalhães; de Souza, Emanuel M; Baldani, José I; Schwab, Stefan

    2017-08-01

    Bacterial endophytes constitute a very diverse community and they confer important benefits which help to improve agricultural yield. Some of these benefits remain underexplored or little understood, mainly due to the bottlenecks associated with the plant feature, a low number of endophytic bacterial cells in relation to the plant, and difficulties in accessing these bacteria using cultivation-independent methods. Enriching endophytic bacterial cells from plant tissues, based on a non-biased, cultivation-independent physical enrichment method, may help to circumvent those problems, especially in the case of sugarcane stems, which have a high degree of interfering factors, such as polysaccharides, phenolic compounds, nucleases, and fibers. In the present study, an enrichment approach for endophytic bacterial cells from sugarcane lower stems is described. The results demonstrate that the enriched bacterial cells are suitable for endophytic community characterization. A community analysis revealed the presence of previously well-described but also novel endophytic bacteria in sugarcane tissues which may exert functions such as plant growth promotion and biological control, with a predominance of the Proteobacterial phylum, but also Actinobacteria, Bacteroidetes, and Firmicutes, among others. In addition, by comparing the present and literature data, it was possible to list the most frequently detected bacterial endophyte genera in sugarcane tissues. The presented enrichment approach paves the way for improved future research toward the assessment of endophytic bacterial community in sugarcane and other biofuel crops.

  4. A regulating method for reducing nitrogen loss based on enriched ammonia-oxidizing bacteria during composting.

    PubMed

    Zhang, Yun; Zhao, Yue; Chen, Yanni; Lu, Qian; Li, Mingxiao; Wang, Xueqin; Wei, Yuquan; Xie, Xinyu; Wei, Zimin

    2016-12-01

    In this study, enriched ammonia-oxidizing bacteria (AOB) were acquired by domesticated cultivation, followed by inoculation into the co-composting of rice straw and chicken manure. The effect of inoculation on nitrogen loss, the succession of bacterial community and the correlation between the key bacteria and environmental factors were investigated. The results showed that inoculation could reduce ammonia emission and nitrogen loss by transforming ammonium into nitrite. Inoculation also increased the amount and abundance of bacterial community. Redundancy analysis showed that indigenous and exogenous bacteria in inoculation group, compared with those in control group, were positively correlated with nitrite but negatively correlated with ammonium, demonstrating that the former contributed to the lower ammonia emission and nitrogen loss. Based on these results, the application of enriched AOB was proposed as a new method of resource recycle and improvement of composting technology. Copyright © 2016 Elsevier Ltd. All rights reserved.

  5. Reduced enrichment for research and test reactors: Proceedings

    SciTech Connect

    Not Available

    1988-05-01

    The international effort to develop new research reactor fuel materials and designs based on the use of low-enriched uranium, instead of highly-enriched uranium, has made much progress during the eight years since its inception. To foster direct communication and exchange of ideas among the specialist in this area, the Reduced Enrichment Research and Test Reactor (RERTR) Program, at the Argonne National Laboratory, sponsored this meeting as the ninth of a series which began in 1978. All previous meetings of this series are listed on the facing page. The focus of this meeting was on the LEU fuel demonstration which was in progress at the Oak Ridge Research (ORR) reactor, not far from where the meeting was held. The visit to the ORR, where a silicide LEU fuel with 4.8 g A/cm/sup 3/ was by then in routine use, illustrated how far work has progressed.

  6. Biodegradation of lindane, methyl parathion and carbofuran by various enriched bacterial isolates.

    PubMed

    Krishna, K Rama; Philip, Ligy

    2008-02-01

    In the present study, lindane (1,2,3,4,5,6-hexachlorocyclohexane), methyl parathion (O-dimethylO-(4-nitro-phenyl) phosphorothioate) and carbofuran (2,3-dihydro-2,2-dimethyl-7-benzofuranyl methylcarbamate) degradation potential of different enriched bacterial cultures were evaluated under various environmental conditions. Enriched cultures behaved differently with different pesticides. Degradation was more in a facultative anaerobic condition as compared to that in aerobic condition. A specific pesticide enriched culture showed maximum degradation of that pesticide irrespective of pesticides and environmental conditions. Lindane and endosulfan enriched cultures behaved almost similarly. Degradation of lindane by lindane enriched cultures was 75 +/- 3% in aerobic co-metabolic process whereas 78 +/- 5% of lindane degradation occurred in anaerobic co-metabolic process. Degradation of methyl parathion by methyl parathion enriched culture was 87 +/- 1% in facultative anaerobic condition. In almost all the cases, many intermediate metabolites were observed. However, many of these metabolites disappeared after 4-6 weeks of incubation. Mixed pesticide-enriched culture degraded all the three pesticides more effectively as compared to specific pesticide- enriched cultures. It can be inferred from the results that a bacterial consortium enriched with a mixture of all the possible pesticides that are present in the site seems to be a better option for the effective bioremediation of multi-pesticide contaminated site.

  7. Sulfate reduction, molecular diversity, and copper amendment effects in bacterial communities enriched from sediments exposed to copper mining residues.

    PubMed

    Pavissich, Juan P; Silva, Macarena; González, Bernardo

    2010-02-01

    Sulfate-reducing bacterial communities from coastal sediments with a long-term exposure to copper (Cu)-mining residues were studied in lactate enrichments. The toxicity of excess copper may affect sulfate-reducing bacterial communities. Sulfate reduction was monitored by sulfate and organic acid measurements. Molecular diversity was analyzed by 16S rRNA, dissimilatory sulfate reduction dsrAB, and Cu translocating phospho-type adenosine triphosphatases (P-ATPases) cop-like gene sequence profiling. The influence of Cu amendment was tested in these enrichments. Results showed fast sulfate reduction mostly coupled to incomplete organic carbon oxidation and partial sulfate reduction inhibition due to copper amendment. The 16S rRNA clonal libraries analysis indicated that delta- and gamma-Proteobacteria and Cytophaga-Flexibacter-Bacteroides dominated the enrichments. The dsrAB libraries revealed the presence of Desulfobacteraceae and Desulfovibrionaceae families-related sequences. Copper produced significant shifts (i.e., a decrease in the relative abundance of sulfate-reducing microorganisms) in the enriched bacterial community structure as determined by terminal-restriction fragment length polymorphism (T-RFLP) profiling and multivariate analyses. Clonal libraries of cop-like sequences showed low richness in the enriched microbial communities, and a strong effect of copper on its relative abundance. Novel Cu-P(IB)-ATPase sequences encoding Cu resistance were detected. The present study indicates that Cu does not significantly affect sulfate reduction and genetic diversity of taxonomic and dissimilatory sulfate-reduction molecular markers. However, the diversity of Cu resistance genetic determinants was strongly modified by this toxic metal.

  8. Effects of copper on sulfate reduction in bacterial consortia enriched from metal-contaminated and uncontaminated sediments.

    PubMed

    Jin, Song; Drever, James I; Colberg, Patricia J S

    2007-02-01

    The effects of copper amendments on bacterial sulfate reduction in enrichment cultures obtained from two types of freshwater sediment were examined. Sulfate-reducing bacterial (SRB) consortia were enriched from pond sediment with no known history of metal contamination (uncontaminated) and from reservoir sediment with a well-documented history of metal contamination (metal-contaminated). The rates and extent of sulfate reduction in each sediment type in the absence of added copper were indistinguishable. With amendments of 0.8 mg/L copper, no inhibitory effects on sulfate reduction were observed in either consortium type. At 8.0 mg/L copper, activity in uncontaminated SRB consortia was significantly inhibited, as evidenced by a delay in and decreased rate of sulfate reduction; sulfidogenesis in metal-contaminated consortia was apparently unaffected. When the dissolved copper concentration was 30.0 mg/L, sulfidogenic activity in pond sediment consortia was completely inhibited. The rate of sulfate reduction temporarily decreased in the metal-contaminated enrichments but recovered after a short time. In active microcosms, copper was precipitated as CuS. The results of this study suggest that SRB from metal-contaminated environments have a markedly higher metal tolerance than those enriched from uncontaminated environments. The most significant inference from this work is that metal sulfide formation alone does not explain observed differences in metal tolerance between SRB consortia enriched from uncontaminated sediments and those that are derived from metal-contaminated sediments.

  9. Soil Bacterial Community Shifts after Chitin Enrichment: An Integrative Metagenomic Approach

    PubMed Central

    Jacquiod, Samuel; Franqueville, Laure; Cécillon, Sébastien; M. Vogel, Timothy; Simonet, Pascal

    2013-01-01

    Chitin is the second most produced biopolymer on Earth after cellulose. Chitin degrading enzymes are promising but untapped sources for developing novel industrial biocatalysts. Hidden amongst uncultivated micro-organisms, new bacterial enzymes can be discovered and exploited by metagenomic approaches through extensive cloning and screening. Enrichment is also a well-known strategy, as it allows selection of organisms adapted to feed on a specific compound. In this study, we investigated how the soil bacterial community responded to chitin enrichment in a microcosm experiment. An integrative metagenomic approach coupling phylochips and high throughput shotgun pyrosequencing was established in order to assess the taxonomical and functional changes in the soil bacterial community. Results indicate that chitin enrichment leads to an increase of Actinobacteria, γ-proteobacteria and β-proteobacteria suggesting specific selection of chitin degrading bacteria belonging to these classes. Part of enriched bacterial genera were not yet reported to be involved in chitin degradation, like the members from the Micrococcineae sub-order (Actinobacteria). An increase of the observed bacterial diversity was noticed, with detection of specific genera only in chitin treated conditions. The relative proportion of metagenomic sequences related to chitin degradation was significantly increased, even if it represents only a tiny fraction of the sequence diversity found in a soil metagenome. PMID:24278158

  10. Enrichment and characterization of sulfate reducing, naphthalene degrading microorganisms

    NASA Astrophysics Data System (ADS)

    Steffen, Kümmel; Florian-Alexander, Herbst; Márcia, Duarte; Dietmar, Pieper; Jana, Seifert; Bergen Martin, von; Hans-Hermann, Richnow; Carsten, Vogt

    2014-05-01

    Polycyclic aromatic hydrocarbons (PAH) are pollutants of great concern due to their potential toxicity, mutagenicity and carcinogenicity. PAH are widely distributed in the environment by accidental discharges during the transport, use and disposal of petroleum products, and during forest and grass fires. Caused by their hydrophobic nature, PAH basically accumulate in sediments from where they are slowly released into the groundwater. Although generally limited by the low water solubility of PAH, microbial degradation is one of the major mechanisms leading to the complete clean-up of PAH-contaminated sites. Whereas organisms and biochemical pathways responsible for the aerobic breakdown of PAH are well known, anaerobic PAH biodegradation is less understood; only a few anaerobic PAH degrading cultures have been described. We studied the anaerobic PAH degradation in a microcosm approach to enrich anaerobic PAH degraders. Anoxic groundwater and sediment samples were used as inoculum. Groundwater samples were purchased from the erstwhile gas works facility and a former wood impregnation site. In contrast, sources of sediment samples were a former coal refining area and an old fuel depot. Samples were incubated in anoxic mineral salt medium with naphthalene as sole carbon source and sulfate as terminal electron acceptor. Grown cultures were characterized by feeding with 13C-labeled naphthalene, 16S rRNA gene sequencing using an Illumina® approach, and functional proteome analyses. Finally, six enrichment cultures able to degrade naphthalene under anoxic conditions were established. First results point to a dominance of identified sequences affiliated to the freshwater sulfate-reducing strain N47, which is a known anaerobic naphthalene degrader, in four out of the six enrichments. In those enrichments, peptides related to the pathway of anoxic naphthalene degradation in N47 were abundant. Overall the data underlines the importance of Desulfobacteria for natural

  11. Reduced enrichment for research and test reactors: Proceedings

    SciTech Connect

    Not Available

    1993-08-01

    November 9--10, 1978, marked the first of what has become an annual event--the International Meeting on Reduced Enrichment for Research and Test Reactors (RERTR). The meeting brought together for the first time many people who became major program participants in later years. This first meeting emphasized fuel development, and it established the basis for all later meetings. Believing that the proceedings of this first meeting are important as a historical record of the beginning of the international RERTR effort. This report provides presentations and discussions of this original meeting. Individual papers have been cataloged separately.

  12. Efficient Enrichment of Bacterial mRNA from Host-Bacteria Total RNA Samples

    PubMed Central

    Kumar, Nikhil; Lin, Mingqun; Zhao, Xuechu; Ott, Sandra; Santana-Cruz, Ivette; Daugherty, Sean; Rikihisa, Yasuko; Sadzewicz, Lisa; Tallon, Luke J.; Fraser, Claire M.; Dunning Hotopp, Julie C.

    2016-01-01

    Despite numerous advances in genomics and bioinformatics, technological hurdles remain to examine host-microbe transcriptomics. Sometimes the transcriptome of either or both can be ascertained merely by generating more sequencing reads. However, many cases exist where bacterial mRNA needs to be enriched further to enable cost-effective sequencing of the pathogen or endosymbiont. While a suitable method is commercially available for mammalian samples of this type, development of such methods has languished for invertebrate samples. Furthermore, a common method across multiple taxa would facilitate comparisons between bacteria in invertebrate vectors and their vertebrate hosts. Here, a method is described to concurrently remove polyadenylated transcripts, prokaryotic rRNA, and eukaryotic rRNA, including those with low amounts of starting material (e.g. 100 ng). In a Wolbachia-Drosophila system, this bacterial mRNA enrichment yielded a 3-fold increase in Wolbachia mRNA abundance and a concomitant 3.3-fold increase in the percentage of transcripts detected. More specifically, 70% of the genome could be recovered by transcriptome sequencing compared to 21% in the total RNA. Sequencing of similar bacterial mRNA-enriched samples generated from Ehrlichia-infected canine cells covers 93% of the Ehrlichia genome, suggesting ubiquitous transcription across the entire Ehrlichia chaffeensis genome. This technique can potentially be used to enrich bacterial mRNA in many studies of host-microbe interactions. PMID:27713560

  13. Broad diversity and newly cultured bacterial isolates from enrichment of pig feces on complex polysaccharides

    USDA-ARS?s Scientific Manuscript database

    One of the fascinating functions of the mammalian intestinal microbiota is the fermentation of plant cell wall components. We used 8 week continuous culture enrichments of pig feces with cellulose and xylan/pectin to isolated bacteria from this community. A total of 575 bacterial isolates were class...

  14. Meiotic genes are enriched in regions of reduced archaic ancestry.

    PubMed

    Jégou, B; Sankararaman, S; Rolland, A D; Reich, D; Chalmel, F

    2017-04-21

    About 1-6% of the genetic ancestry of modern humans today originates from admixture with archaic humans. It has recently been shown that autosomal genomic regions with a reduced proportion of Neanderthal and Denisovan ancestries are significantly enriched in genes that are more expressed in testis than in other tissues. To determine whether a cellular segregation pattern would exist, we combined maps of archaic introgression with a cross-analysis of three transcriptomic datasets deciphering the transcriptional landscape of human gonadal cell types. We reveal that the regions deficient in both Neanderthal and Denisovan ancestries contain a significant enrichment of genes transcribed in meiotic germ cells. The interbreeding of anatomically modern humans with archaic humans may have introduced archaic-derived alleles that contributed to genetic incompatibilities affecting meiosis that were subsequently purged by natural selection. © The Author 2017. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  15. Carbon-driven enrichment of the crucial nitrate-reducing bacteria in limed peat soil microcosms.

    PubMed

    Zhu, Y; Zhang, X; Wu, X; Chen, G; Bakken, L R; Zhao, L; Frostegård, Å; Zhang, X

    2017-08-01

    Bacteria of Dechloromonas were recognized as potential functional important denitrifiers in a long-term shell sand-amended peat soil. Different microcosms in a solid matrix and slurry systems with the addition of carbon and nitrogen sources, for example, clover leaves, glutamate and nitrate, were established. The bacterial community structures were analysed by pyrosequencing of the 16S rRNA gene to select the conditions for enriching bacteria of Dechloromonas. The results showed that a relatively even bacterial community in the initial soil shifted to communities dominated by a few types of nitrate-reducing bacteria after the incubation, which strongly responded to the carbon substrates addition and consumption. The bacteria of several genera including Dechloromonas, Pseudomonas, Clostridium, Aeromonas and Ferribacterium were significantly enriched after a certain period of time. The bacteria of Dechloromonas became one of the most predominant bacteria in the incubated community. Especially when added the mixed carbon substrates into the solid soil matrix, as high as 34% of abundance was detected. This study proved that the functional important bacteria from the genus of Dechloromonas could be enriched to an extremely high abundance by using proper culture condition which will benefit to the isolation or direct metagenomics study for Dechloromonas. The study of key players in a microbial community is always of important. In this study, the functional important denitrifiers in a shell sand-amended peat soil were investigated. Using different carbon sources in the incubation, we found the bacteria from the genus of Dechloromonas were enriched to an abundance of higher than 34% with several other denitrifiers together. This work provides us helpful insights not only for knowing the diversity of denitrifiers in the studied peat soil, but also for understanding their response to the carbon sources and the culture conditions. © 2017 The Society for Applied Microbiology.

  16. Bacterial community analysis in chlorpyrifos enrichment cultures via DGGE and use of bacterial consortium for CP biodegradation.

    PubMed

    Akbar, Shamsa; Sultan, Sikander; Kertesz, Michael

    2014-10-01

    The organophosphate pesticide chlorpyrifos (CP) has been used extensively since the 1960s for insect control. However, its toxic effects on mammals and persistence in environment necessitate its removal from contaminated sites, biodegradation studies of CP-degrading microbes are therefore of immense importance. Samples from a Pakistani agricultural soil with an extensive history of CP application were used to prepare enrichment cultures using CP as sole carbon source for bacterial community analysis and isolation of CP metabolizing bacteria. Bacterial community analysis (denaturing gradient gel electrophoresis) revealed that the dominant genera enriched under these conditions were Pseudomonas, Acinetobacter and Stenotrophomonas, along with lower numbers of Sphingomonas, Agrobacterium and Burkholderia. Furthermore, it revealed that members of Bacteroidetes, Firmicutes, α- and γ-Proteobacteria and Actinobacteria were present at initial steps of enrichment whereas β-Proteobacteria appeared in later steps and only Proteobacteria were selected by enrichment culturing. However, when CP-degrading strains were isolated from this enrichment culture, the most active organisms were strains of Acinetobacter calcoaceticus, Pseudomonas mendocina and Pseudomonas aeruginosa. These strains degraded 6-7.4 mg L(-1) day(-1) of CP when cultivated in mineral medium, while the consortium of all four strains degraded 9.2 mg L(-1) day(-1) of CP (100 mg L(-1)). Addition of glucose as an additional C source increased the degradation capacity by 8-14 %. After inoculation of contaminated soil with CP (200 mg kg(-1)) disappearance rates were 3.83-4.30 mg kg(-1) day(-1) for individual strains and 4.76 mg kg(-1) day(-1) for the consortium. These results indicate that these organisms are involved in the degradation of CP in soil and represent valuable candidates for in situ bioremediation of contaminated soils and waters.

  17. Effective bioleaching of chromium in tannery sludge with an enriched sulfur-oxidizing bacterial community.

    PubMed

    Zeng, Jing; Gou, Min; Tang, Yue-Qin; Li, Guo-Ying; Sun, Zhao-Yong; Kida, Kenji

    2016-10-01

    In this study, a sulfur-oxidizing community was enriched from activated sludge generated in tannery wastewater treatment plants. Bioleaching of tannery sludge containing 0.9-1.2% chromium was investigated to evaluate the effectiveness of the enriched community, the effect of chromium binding forms on bioleaching efficiency, and the dominant microbes contributing to chromium bioleaching. Sludge samples inoculated with the enriched community presented 79.9-96.8% of chromium leaching efficiencies, much higher than those without the enriched community. High bioleaching efficiencies of over 95% were achieved for chromium in reducible fraction, while 60.9-97.9% were observed for chromium in oxidizable and residual fractions. Acidithiobacillus thiooxidans, the predominant bacteria in the enriched community, played an important role in bioleaching, whereas some indigenous heterotrophic species in sludge might have had a supporting role. The results indicated that A. thiooxidans-dominant enriched microbial community had high chromium bioleaching efficiency, and chromium binding forms affected the bioleaching performance.

  18. Environmental Enrichment Reduces Signs of Boredom in Caged Mink

    PubMed Central

    Meagher, Rebecca K.; Mason, Georgia J.

    2012-01-01

    ). Boredom can thus be operationalized and assessed empirically in non-human animals. It can also be reduced by environmental enrichment. PMID:23155462

  19. Anaerobic naphthalene degradation by a sulfate-reducing enrichment culture.

    PubMed

    Meckenstock, R U; Annweiler, E; Michaelis, W; Richnow, H H; Schink, B

    2000-07-01

    Anaerobic naphthalene degradation by a sulfate-reducing enrichment culture was studied by substrate utilization tests and identification of metabolites by gas chromatography-mass spectrometry. In substrate utilization tests, the culture was able to oxidize naphthalene, 2-methylnaphthalene, 1- and 2-naphthoic acids, phenylacetic acid, benzoic acid, cyclohexanecarboxylic acid, and cyclohex-1-ene-carboxylic acid with sulfate as the electron acceptor. Neither hydroxylated 1- or 2-naphthoic acid derivatives and 1- or 2-naphthol nor the monoaromatic compounds ortho-phthalic acid, 2-carboxy-1-phenylacetic acid, and salicylic acid were utilized by the culture within 100 days. 2-Naphthoic acid accumulated in all naphthalene-grown cultures. Reduced 2-naphthoic acid derivatives could be identified by comparison of mass spectra and coelution with commercial reference compounds such as 1,2,3, 4-tetrahydro-2-naphthoic acid and chemically synthesized decahydro-2-naphthoic acid. 5,6,7,8-Tetrahydro-2-naphthoic acid and octahydro-2-naphthoic acid were tentatively identified by their mass spectra. The metabolites identified suggest a stepwise reduction of the aromatic ring system before ring cleavage. In degradation experiments with [1-(13)C]naphthalene or deuterated D(8)-naphthalene, all metabolites mentioned derived from the introduced labeled naphthalene. When a [(13)C]bicarbonate-buffered growth medium was used in conjunction with unlabeled naphthalene, (13)C incorporation into the carboxylic group of 2-naphthoic acid was shown, indicating that activation of naphthalene by carboxylation was the initial degradation step. No ring fission products were identified.

  20. Anaerobic Naphthalene Degradation by a Sulfate-Reducing Enrichment Culture†

    PubMed Central

    Meckenstock, Rainer U.; Annweiler, Eva; Michaelis, Walter; Richnow, Hans H.; Schink, Bernhard

    2000-01-01

    Anaerobic naphthalene degradation by a sulfate-reducing enrichment culture was studied by substrate utilization tests and identification of metabolites by gas chromatography-mass spectrometry. In substrate utilization tests, the culture was able to oxidize naphthalene, 2-methylnaphthalene, 1- and 2-naphthoic acids, phenylacetic acid, benzoic acid, cyclohexanecarboxylic acid, and cyclohex-1-ene-carboxylic acid with sulfate as the electron acceptor. Neither hydroxylated 1- or 2-naphthoic acid derivatives and 1- or 2-naphthol nor the monoaromatic compounds ortho-phthalic acid, 2-carboxy-1-phenylacetic acid, and salicylic acid were utilized by the culture within 100 days. 2-Naphthoic acid accumulated in all naphthalene-grown cultures. Reduced 2-naphthoic acid derivatives could be identified by comparison of mass spectra and coelution with commercial reference compounds such as 1,2,3,4-tetrahydro-2-naphthoic acid and chemically synthesized decahydro-2-naphthoic acid. 5,6,7,8-Tetrahydro-2-naphthoic acid and octahydro-2-naphthoic acid were tentatively identified by their mass spectra. The metabolites identified suggest a stepwise reduction of the aromatic ring system before ring cleavage. In degradation experiments with [1-13C]naphthalene or deuterated D8-naphthalene, all metabolites mentioned derived from the introduced labeled naphthalene. When a [13C]bicarbonate-buffered growth medium was used in conjunction with unlabeled naphthalene, 13C incorporation into the carboxylic group of 2-naphthoic acid was shown, indicating that activation of naphthalene by carboxylation was the initial degradation step. No ring fission products were identified. PMID:10877763

  1. Status of reduced enrichment programs for research reactors in Japan

    SciTech Connect

    Kanda, Keiji; Nishihara, Hedeaki; Shirai, Eiji; Oyamada, Rokuro; Sanokawa, Konomo

    1997-08-01

    The reduced enrichment programs for the JRR-2, JRR-3, JRR-4 and JMTR of Japan Atomic Energy Research Institute (JAERI), and the KUR of Kyoto University Research Reactor Institute (KURRI) have been partially completed and are mostly still in progress under the Joint Study Programs with Argonne National Laboratory (ANL). The JMTR and JRR-2 have been already converted to use MEU aluminide fuels in 1986 and 1987, respectively. The operation of the upgraded JRR-3(JRR-3M) has started in March 1990 with the LEU aluminide fuels. Since May 1992, the two elements have been inserted in the KUR. The safety review application for the full core conversion to use LEU silicide in the JMTR was approved in February 1992 and the conversion has been done in January 1994. The Japanese Government approved a cancellation of the KUHFR Project in February 1991, and in April 1994 the U.S. Government gave an approval to utilize HEU in the KUR instead of the KUHFR. Therefore, the KUR will be operated with HEU fuel until 2001. Since March 1994, Kyoto University is continuing negotiation with UKAEA Dounreay on spent fuel reprocessing and blending down of recovered uranium, in addition to that with USDOE.

  2. Bacterial oxidation of dibromomethane and methyl bromide in natural waters and enrichment cultures

    USGS Publications Warehouse

    Goodwin, K.D.; Schaefer, J.K.; Oremland, R.S.

    1998-01-01

    Bacterial oxidation of 14CH2Br2 and 14CH3Br was measured in freshwater, estuarine, seawater, and hypersaline-alkaline samples. In general, bacteria from the various sites oxidized similar amounts of 14CH2Br2 and comparatively less 14CH3Br. Bacterial oxidation of 14CH3Br was rapid in freshwater samples compared to bacterial oxidation of 14CH3Br in more saline waters. Freshwater was also the only site in which methyl fluoride-sensitive bacteria (e.g., methanotrophs or nitrifiers) governed brominated methane oxidation. Half-life calculations indicated that bacterial oxidation of CH2Br2 was potentially significant in all of the waters tested. In contrast, only in freshwater was bacterial oxidation of CH3Br as fast as chemical removal. The values calculated for more saline sites suggested that bacterial oxidation of CH3Br was relatively slow compared to chemical and physical loss mechanisms. However, enrichment cultures demonstrated that bacteria in seawater can rapidly oxidize brominated methanes. Two distinct cultures of nonmethanotrophic methylotrophs were recovered; one of these cultures was able to utilize CH2Br2 as a sole carbon source, and the other was able to utilize CH3Br as a sole carbon source.

  3. Resource Availability and Spatial Heterogeneity Control Bacterial Community Response to Nutrient Enrichment in Lakes

    PubMed Central

    Jankowski, KathiJo; Schindler, Daniel E.; Horner-Devine, M. Claire

    2014-01-01

    The diversity and composition of ecological communities often co-vary with ecosystem productivity. However, the relative importance of productivity, or resource abundance, versus the spatial distribution of resources in shaping those ecological patterns is not well understood, particularly for the bacterial communities that underlie most important ecosystem functions. Increasing ecosystem productivity in lakes has been shown to influence the composition and ecology of bacterial communities, but existing work has only evaluated the effect of increasing resource supply and not heterogeneity in how those resources are distributed. We quantified how bacterial communities varied with the trophic status of lakes and whether community responses differed in surface and deep habitats in response to heterogeneity in nutrient resources. Using ARISA fingerprinting, we found that bacterial communities were more abundant, richer, and more distinct among habitats as lake trophic state and vertical heterogeneity in nutrients increased, and that spatial resource variation produced habitat specific responses of bacteria in response to increased productivity. Furthermore, changes in communities in high nutrient lakes were not produced by turnover in community composition but from additional taxa augmenting core bacterial communities found in lower productivity lakes. These data suggests that bacterial community responses to nutrient enrichment in lakes vary spatially and are likely influenced disproportionately by rare taxa. PMID:24489823

  4. Microbial response to a mesoscale iron enrichment in the NE Subarctic Pacific: Bacterial community composition

    NASA Astrophysics Data System (ADS)

    Agawin, Nona S. R.; Hale, Michelle S.; Rivkin, Richard B.; Matthews, Paul; Li, William K. W.

    2006-10-01

    Changes in microbial community composition were determined during the subarctic ecosystem response to iron enrichment study (SERIES), a mesoscale Fe enrichment conducted in a high-nutrient low-chlorophyll (HNLC) region of the Northeast Subarctic Pacific, in July 2002. Phylogenetic composition using fluorescence in situ hybridization (FISH), relative DNA content using flow cytometry (FCM), and cellular morphometrics (shape and volume) of heterotrophic bacteria were used to characterize community composition from samples collected within and below the mixed layer, inside and outside the Fe-patch. The proportion of total cells detected as members of the Cytophaga-Flavobacterium cluster increased in a log-linear manner from 16 (±1.0)% to 47 (±1.9)% in samples within the mixed layer, inside the Fe-enriched patch, while outside the patch, the proportion remained ⩽21 (±2.2)%. Temporal changes in the proportion of cells in the mixed layer with high DNA content (% HDNA) were significantly different inside and outside the Fe-enriched patch, where inside the patch % HDNA increased 2-fold after a week, reaching 93% towards the end of the observation period. Coupling in situ observations with the results of manipulation experiments allowed us to determine the relative contributions of bottom-up (nutrient limitation) and top-down (grazing) processes on heterotrophic bacterial abundance and community composition. Shifts in heterotrophic bacterial community composition inside the Fe-enriched patch were mainly controlled by top-down processes and moderately controlled by bottom-up controls (organic substrate limitation).

  5. Bacterial community analysis of cypermethrin enrichment cultures and bioremediation of cypermethrin contaminated soils.

    PubMed

    Akbar, Shamsa; Sultan, Sikander; Kertesz, Michael

    2015-07-01

    Cypermethrin is widely used for insect control; however, its toxicity toward aquatic life requires its complete removal from contaminated areas where the natural degradation ability of microbes can be utilized. Agricultural soil with extensive history of CM application was used to prepare enrichment cultures using cypermethrin as sole carbon source for isolation of cypermethrin degrading bacteria and bacterial community analysis using PCR-DGGE of 16 S rRNA gene. DGGE analysis revealed that dominant members of CM enrichment culture were associated with α-proteobacteria followed by γ-proteobacteria, Firmicutes, and Actinobacteria. Three potential CM-degrading isolates identified as Ochrobactrum anthropi JCm1, Bacillus megaterium JCm2, and Rhodococcus sp. JCm5 degraded 86-100% of CM (100 mg L(-1) ) within 10 days. These isolates were also able to degrade other pyrethroids, carbofuran, and cypermethrin degradation products. Enzyme activity assays revealed that enzymes involved in CM-degradation were inducible and showed activity when strains were grown on cypermethrin. Degradation kinetics of cypermethrin (200 mg kg(-1)) in soils inoculated with isolates JCm1, JCm2, and JCm5 suggested time-dependent disappearance of cypermethrin with rate constants of 0.0516, 0.0425, and 0.0807 d(-1), respectively, following first order rate kinetics. The isolated bacterial strains were among dominant genera selected under CM enriched conditions and represent valuable candidates for in situ bioremediation of contaminated soils and waters.

  6. Chemolithotrophic processes in the bacterial communities on the surface of mineral-enriched biochars.

    PubMed

    Ye, Jun; Joseph, Stephen D; Ji, Mukan; Nielsen, Shaun; Mitchell, David R G; Donne, Scott; Horvat, Joseph; Wang, Jianli; Munroe, Paul; Thomas, Torsten

    2017-02-07

    Biochar and mineral-enriched biochar (MEB) have been used as soil amendments to improve soil fertility, sequester carbon and mitigate greenhouse gas emissions. Such beneficial outcomes could be partially mediated by soil bacteria, however little is known about how they directly interact with biochar or MEB. We therefore analyzed the diversity and functions of bacterial communities on the surfaces of one biochar and two different MEBs after a 140-day incubation in soil. The results show that the biochar and the MEBs harbor distinct bacterial communities to the bulk soil. Communities on biochar and MEBs were dominated by a novel Gammaproteobacterium. Genome reconstruction combined with electron microscopy and high-resolution elemental analysis revealed that the bacterium generates energy from the oxidation of iron that is present on the surface. Two other bacteria belonging to the genus Thiobacillus and a novel group within the Oxalbacteraceae were enriched only on the MEBs and they had the genetic capacity for thiosulfate oxidation. All three surface-enriched bacteria also had the capacity to fix carbon dioxide, either in a potentially strictly autotrophic or mixotrophic manner. Our results show the dominance of chemolithotrophic processes on the surface of biochar and MEB that can contribute to carbon sequestration in soil.The ISME Journal advance online publication, 7 February 2017; doi:10.1038/ismej.2016.187.

  7. [Bacterial diversity analysis of moderately thermophilic microflora enriched by different energy sources].

    PubMed

    Liu, Fei-fei; Zhou, Hong-bo; Fu, Bo; Qiu, Guan-zhou

    2007-06-01

    Bacterial biodiversities of three moderately thermophilic bioleaching microfloras grown at 50 degrees C on media with pyrite, chalcopyrite, and pure ferrous iron supplemented with sulfur as energy sources were investigated respectively. The 16S rRNA genes of the microorganisms in the cultures flasks were PCR amplified and cloned to identify the bacterial species by comparative sequence analysis, the structural differences of microfloras enriched by different energy sources were compared. A total of 303 clones were recovered and evaluated by restriction fragment length polymorphism (RFLP) analysis. Cluster analysis identified 29 unique RFLP patterns, and the inserted 16S rRNA genes sequences were determined and for phylogenetic analysis. Most of sequences obtained were similar (89.1%-99.7%) to the 16S rRNA gene sequences of the reported bioleaching microorganisms. The species identified from the flasks during bioleaching of pyrite, pure ferrous iron supplemented with sulfur, and chalcopyrite were closely related to Acidithiobacillus caldus, Sulfobacillus thermotolerans, Sulfobacillus thermosulfidooxidans, Leptospirillum ferriphilum, two uncultured forest soil bacterium clones and one uncultured proteobacterium clone. Among these bacteria, Acidithiobacillus caldus, Sulfobacillus thermotolerans and Leptospirillum ferriphilum were the dominant bacterial species. L. ferriphilum was the most dominant species in microfloras enriched in media with pyrite and ferrous iron supplemented with sulfur as energy sources, the abundance were 53.8% and 45.9% respectively. In the culture with chalcopyrite as energy sources, S. thermotolerans had the highest abundance of 70.1%.

  8. High-pressure saline washing of allografts reduces bacterial contamination.

    PubMed

    Hirn, M Y; Salmela, P M; Vuento, R E

    2001-02-01

    60 fresh-frozen bone allografts were contaminated on the operating room floor. No bacterial growth was detected in 5 of them after contamination. The remaining 55 grafts had positive bacterial cultures and were processed with three methods: soaking in saline, soaking in antibiotic solution or washing by high-pressure saline. After high-pressure lavage, the cultures were negative in three fourths of the contaminated allografts. The corresponding figures after soaking grafts in saline and antibiotic solution were one tenth and two tenths, respectively. High-pressure saline cleansing of allografts can be recommended because it improves safety by reducing the superficial bacterial bioburden.

  9. Differential Response of High-Elevation Planktonic Bacterial Community Structure and Metabolism to Experimental Nutrient Enrichment

    PubMed Central

    Nelson, Craig E.; Carlson, Craig A.

    2011-01-01

    Nutrient enrichment of high-elevation freshwater ecosystems by atmospheric deposition is increasing worldwide, and bacteria are a key conduit for the metabolism of organic matter in these oligotrophic environments. We conducted two distinct in situ microcosm experiments in a high-elevation lake (Emerald Lake, Sierra Nevada, California, USA) to evaluate responses in bacterioplankton growth, carbon utilization, and community structure to short-term enrichment by nitrate and phosphate. The first experiment, conducted just following ice-off, employed dark dilution culture to directly assess the impact of nutrients on bacterioplankton growth and consumption of terrigenous dissolved organic matter during snowmelt. The second experiment, conducted in transparent microcosms during autumn overturn, examined how bacterioplankton in unmanipulated microbial communities responded to nutrients concomitant with increasing phytoplankton-derived organic matter. In both experiments, phosphate enrichment (but not nitrate) caused significant increases in bacterioplankton growth, changed particulate organic stoichiometry, and induced shifts in bacterial community composition, including consistent declines in the relative abundance of Actinobacteria. The dark dilution culture showed a significant increase in dissolved organic carbon removal in response to phosphate enrichment. In transparent microcosms nutrient enrichment had no effect on concentrations of chlorophyll, carbon, or the fluorescence characteristics of dissolved organic matter, suggesting that bacterioplankton responses were independent of phytoplankton responses. These results demonstrate that bacterioplankton communities in unproductive high-elevation habitats can rapidly alter their taxonomic composition and metabolism in response to short-term phosphate enrichment. Our results reinforce the key role that phosphorus plays in oligotrophic lake ecosystems, clarify the nature of bacterioplankton nutrient limitation, and

  10. Degradative capacities and 16S rRNA-targeted whole-cell hybridization of sulfate-reducing bacteria in an anaerobic enrichment culture utilizing alkylbenzenes from crude oil

    SciTech Connect

    Rabus, R.; Widdel, F.; Fukui, Manabu

    1996-10-01

    Production of sulfide in oil field waters, a process which is referred to as souring, has been of concern. Hydrogen sulfide may lead to poisoning, contamination of oil and gas, corrosion of pipelines, conversion of iron mineral to ferrous sulfide. This study used a previously established sulfate-reducing enrichment culture on crude oil as a model system of bacterial habitats in which crude oil is the only potential source of organic substrates, and the enrichment culture was studied in detail including substrate preferences and major nutritional types of sulfate-reducing bacteria in the enrichment culture. 74 refs., 2 figs., 2 tabs.

  11. Molecular fingerprinting of bacterial communities in enriched azo dye (Reactive Violet 5R) decolorising native acclimatised bacterial consortia.

    PubMed

    Rathod, Jagat; Archana, G

    2013-08-01

    Reactive Violet 5R (RV5R) decolorising acclimatised bacterial consortia were enriched from industrial effluent contaminated and pristine samples from Gujarat, India on several different media. Twelve acclimatised consortia were selected for the study which were able to decolorise 100mg/L RV5R in 30 h under shaking or static conditions. Eubacterial diversity was studied by 16S rRNA gene based culture-independent methods, using HaeIII and Hinf1 enzymes for ARDRA and V3 region based DGGE analysis, forming total 6 clusters in both analysis. Decolorised end products of all the consortia were analysed by FTIR showing cleavage of the azo bond and group modifications. GC-MS data of dye decolorised end products of Gly consortium obtained from hydrocarbon contaminated soil demonstrated benzene ring cleavage activity. Present study suggests that enrichment of acclimatised consortia under different conditions can result in diverse microbial communities that differentially degrade RV5R and can provide rich source of dye decolorising strains. Copyright © 2013 Elsevier Ltd. All rights reserved.

  12. Biodegradation of polycyclic aromatic hydrocarbons by a bacterial consortium enriched from mangrove sediments.

    PubMed

    Shahriari Moghadam, Mohsen; Ebrahimipour, Gholamhossein; Abtahi, Behrooz; Ghassempour, Alireza; Hashtroudi, Mehri Seyed

    2014-01-01

    Polycyclic aromatic hydrocarbons (PAHs) biodegradation in contaminated sediment is an attractive remediation technique and its success depends on the optimal condition for the PAH-degrading isolates. The aims of the current study was to isolate and identify PAHs-degrading bacteria from surface sediments of Nayband Bay and to evaluate the efficiency of statistically based experimental design for the optimization of phenanthrene (Phe) and Fluorene (Flu) biodegradation performed by enriched consortium. PAHs degrading bacteria were isolated from surface sediments. Purified strains were then identified by 16S rDNA gene sequence analysis. Taguchi L16 (4(5)) was employed to evaluate the optimum biodegradation of Phe and Flu by the enriched consortium. Total of six gram-negative bacterial strains including Marinobacter hydrocarbonoclasticus, Roseovarius pacificus, Pseudidiomarina sediminum and 3 unidentified strains were isolated from enrichment consortium, using Fluorene (Flu) and phenanthrene (Phe) as the sole carbon and energy source. The enriched consortium showed highest degradation abilities (64.0% Flu and 58.4% Phe degraded in 7 days) in comparison to a single strain cultures or mixtures. Maximum biodegradation efficiency was occur at temperature = 35°C; pH = 8; inoculum size = 0. 4 OD600nm; salinity = 40 ppt; C/N ratio = 100:10. In conclusion our results showed that, indigenous bacteria from mangrove surface sediments of Nayband Bay have high potential to degrade Flu and Phe with the best results achieved when enriched consortium was used.

  13. Reducing Salt in Raw Pork Sausages Increases Spoilage and Correlates with Reduced Bacterial Diversity

    PubMed Central

    Fougy, Lysiane; Desmonts, Marie-Hélène; Coeuret, Gwendoline; Fassel, Christine; Hamon, Erwann; Hézard, Bernard; Champomier-Vergès, Marie-Christine

    2016-01-01

    ABSTRACT Raw sausages are perishable foodstuffs; reducing their salt content raises questions about a possible increased spoilage of these products. In this study, we evaluated the influence of salt reduction (from 2.0% to 1.5% [wt/wt]), in combination with two types of packaging (modified atmosphere [50% mix of CO2-N2] and vacuum packaging), on the onset of spoilage and on the diversity of spoilage-associated bacteria. After 21 days of storage at 8°C, spoilage was easily observed, characterized by noticeable graying of the products and the production of gas and off-odors defined as rancid, sulfurous, or sour. At least one of these types of spoilage occurred in each sample, and the global spoilage intensity was more pronounced in samples stored under modified atmosphere than under vacuum packaging and in samples with the lower salt content. Metagenetic 16S rRNA pyrosequencing revealed that vacuum-packaged samples contained a higher total bacterial richness (n = 69 operational taxonomic units [OTUs]) than samples under the other packaging condition (n = 46 OTUs). The core community was composed of 6 OTUs (Lactobacillus sakei, Lactococcus piscium, Carnobacterium divergens, Carnobacterium maltaromaticum, Serratia proteamaculans, and Brochothrix thermosphacta), whereas 13 OTUs taxonomically assigned to the Enterobacteriaceae, Enterococcaceae, and Leuconostocaceae families comprised a less-abundant subpopulation. This subdominant community was significantly more abundant when 2.0% salt and vacuum packaging were used, and this correlated with a lower degree of spoilage. Our results demonstrate that salt reduction, particularly when it is combined with CO2-enriched packaging, promotes faster spoilage of raw sausages by lowering the overall bacterial diversity (both richness and evenness). IMPORTANCE Our study takes place in the context of raw meat product manufacturing and is linked to a requirement for salt reduction. Health guidelines are calling for a reduction in

  14. EXAFS study on the cause of enrichment of heavy REEs on bacterial cell surfaces

    NASA Astrophysics Data System (ADS)

    Takahashi, Yoshio; Yamamoto, Mika; Yamamoto, Yuhei; Tanaka, Kazuya

    2010-10-01

    Rare earth element (REE) pattern is a unique geochemical tracer and has been measured for various natural materials. Among these, the REE distribution pattern between bacteria and water exhibits anomalous enrichment in the heavy REE (HREE) part, which can act as a signature of bacteria-related materials in natural samples. In this study, the REE binding site on the cell surface of a Gram-positive bacterium ( Bacillus subtilis) responsible for HREE enrichment has been identified using extended X-ray absorption fine structure (EXAFS) coupled with a study of the variation in REE distribution patterns. The EXAFS data showed that the HREEs form complexes with multiple phosphate site (including phosphoester site) with a larger coordination number (CN) at lower REE-bacteria ratios ([REE]/[bac]), while light and middle REEs form complexes to the phosphate site with a lower CN. The fraction coordinated to carboxylate increased for all REEs with increasing [REE]/[bac] ratio. On the other hand, the enrichment of HREE in the REE distribution patterns of the bacteria was less marked with increasing [REE]/[bac] ratio. This result is consistent with the EXAFS data, because the REE pattern of surface complex with multiple phosphate in a reference material exhibits a monotonous increase for heavier REE, while phosphate surface complex with a low CN and a carboxylate site reach a maximum around Sm and Eu. Based on these results, it is clear that the REE are primarily bound to the phosphate site and subsequently to the carboxylate site on the bacterial cell surface. Regarding the pH dependence in the range (3 < pH < 7), both the EXAFS and REE pattern data indicate that the fraction of REE-carboxylate increased as the pH increases. The results above obtained for B. subtilis were also valid for Escherichia coli, a Gram-negative bacterium, showing that similar phosphate and carboxylate sites are also available in the cell walls of E. coli, or other Gram negative bacteria. In all our

  15. Proceedings of the 1988 International Meeting on Reduced Enrichment for Research and Test Reactors

    SciTech Connect

    Not Available

    1993-07-01

    The international effort to develop and implement new research reactor fuels utilizing low-enriched uranium, instead of highly- enriched uranium, continues to make solid progress. This effort is the cornerstone of a widely shared policy aimed at reducing, and possibly eliminating, international traffic in highly-enriched uranium and the nuclear weapon proliferation concerns associated with this traffic. To foster direct communication and exchange of ideas among the specialists in this area, the Reduced Enrichment Research and Test Reactor (RERTR) Program, at Argonne National Laboratory, sponsored this meeting as the eleventh of a series which began 1978. Individual papers presented at the meeting have been cataloged separately.

  16. Principal Angle Enrichment Analysis (PAEA): Dimensionally Reduced Multivariate Gene Set Enrichment Analysis Tool.

    PubMed

    Clark, Neil R; Szymkiewicz, Maciej; Wang, Zichen; Monteiro, Caroline D; Jones, Matthew R; Ma'ayan, Avi

    2015-11-01

    Gene set analysis of differential expression, which identifies collectively differentially expressed gene sets, has become an important tool for biology. The power of this approach lies in its reduction of the dimensionality of the statistical problem and its incorporation of biological interpretation by construction. Many approaches to gene set analysis have been proposed, but benchmarking their performance in the setting of real biological data is difficult due to the lack of a gold standard. In a previously published work we proposed a geometrical approach to differential expression which performed highly in benchmarking tests and compared well to the most popular methods of differential gene expression. As reported, this approach has a natural extension to gene set analysis which we call Principal Angle Enrichment Analysis (PAEA). PAEA employs dimensionality reduction and a multivariate approach for gene set enrichment analysis. However, the performance of this method has not been assessed nor its implementation as a web-based tool. Here we describe new benchmarking protocols for gene set analysis methods and find that PAEA performs highly. The PAEA method is implemented as a user-friendly web-based tool, which contains 70 gene set libraries and is freely available to the community.

  17. Tetrachloromethane-Degrading Bacterial Enrichment Cultures and Isolates from a Contaminated Aquifer

    PubMed Central

    Penny, Christian; Gruffaz, Christelle; Nadalig, Thierry; Cauchie, Henry-Michel; Vuilleumier, Stéphane; Bringel, Françoise

    2015-01-01

    Abstract: The prokaryotic community of a groundwater aquifer exposed to high concentrations of tetrachloromethane (CCl4) for more than three decades was followed by terminal restriction fragment length polymorphism (T-RFLP) during pump-and-treat remediation at the contamination source. Bacterial enrichments and isolates were obtained under selective anoxic conditions, and degraded 10 mg·L−1 CCl4, with less than 10% transient formation of chloroform. Dichloromethane and chloromethane were not detected. Several tetrachloromethane-degrading strains were isolated from these enrichments, including bacteria from the Klebsiella and Clostridium genera closely related to previously described CCl4 degrading bacteria, and strain TM1, assigned to the genus Pelosinus, for which this property was not yet described. Pelosinus sp. TM1, an oxygen-tolerant, Gram-positive bacterium with strictly anaerobic metabolism, excreted a thermostable metabolite into the culture medium that allowed extracellular CCl4 transformation. As estimated by T-RFLP, phylotypes of CCl4-degrading enrichment cultures represented less than 7%, and archaeal and Pelosinus strains less than 0.5% of the total prokaryotic groundwater community. PMID:27682092

  18. An integrated microfluidic analysis microsystems with bacterial capture enrichment and in-situ impedance detection

    NASA Astrophysics Data System (ADS)

    Liu, Hai-Tao; Wen, Zhi-Yu; Xu, Yi; Shang, Zheng-Guo; Peng, Jin-Lan; Tian, Peng

    2017-09-01

    In this paper, an integrated microfluidic analysis microsystems with bacterial capture enrichment and in-situ impedance detection was purposed based on microfluidic chips dielectrophoresis technique and electrochemical impedance detection principle. The microsystems include microfluidic chip, main control module, and drive and control module, and signal detection and processing modulet and result display unit. The main control module produce the work sequence of impedance detection system parts and achieve data communication functions, the drive and control circuit generate AC signal which amplitude and frequency adjustable, and it was applied on the foodborne pathogens impedance analysis microsystems to realize the capture enrichment and impedance detection. The signal detection and processing circuit translate the current signal into impendence of bacteria, and transfer to computer, the last detection result is displayed on the computer. The experiment sample was prepared by adding Escherichia coli standard sample into chicken sample solution, and the samples were tested on the dielectrophoresis chip capture enrichment and in-situ impedance detection microsystems with micro-array electrode microfluidic chips. The experiments show that the Escherichia coli detection limit of microsystems is 5 × 104 CFU/mL and the detection time is within 6 min in the optimization of voltage detection 10 V and detection frequency 500 KHz operating conditions. The integrated microfluidic analysis microsystems laid the solid foundation for rapid real-time in-situ detection of bacteria.

  19. Reducing atelectasis attenuates bacterial growth and translocation in experimental pneumonia.

    PubMed

    van Kaam, Anton H; Lachmann, Robert A; Herting, Egbert; De Jaegere, Anne; van Iwaarden, Freek; Noorduyn, L Arnold; Kok, Joke H; Haitsma, Jack J; Lachmann, Burkhard

    2004-05-01

    Besides being one of the mechanisms responsible for ventilator-induced lung injury, atelectasis also seems to aggravate the course of experimental pneumonia. In this study, we examined the effect of reducing the degree of atelectasis by natural modified surfactant and/or open lung ventilation on bacterial growth and translocation in a piglet model of Group B streptococcal pneumonia. After creating surfactant deficiency by whole lung lavage, intratracheal instillation of bacteria induced severe pneumonia with bacterial translocation into the blood stream, resulting in a mortality rate of almost 80%. Treatment with 300 mg/kg of exogenous surfactant before instillation of streptococci attenuated both bacterial growth and translocation and prevented clinical deterioration. This goal was also achieved by reversing atelectasis in lavaged animals via open lung ventilation. Combining both exogenous surfactant and open lung ventilation prevented bacterial translocation completely, comparable to Group B streptococci instillation into healthy animals. We conclude that exogenous surfactant and open lung ventilation attenuate bacterial growth and translocation in experimental pneumonia and that this attenuation is at least in part mediated by a reduction in atelectasis. These findings suggest that minimizing alveolar collapse by exogenous surfactant and open lung ventilation may reduce the risk of pneumonia and subsequent sepsis in ventilated patients.

  20. Polycyclic Aromatic Hydrocarbon-Induced Changes in Bacterial Community Structure under Anoxic Nitrate Reducing Conditions

    PubMed Central

    Martirani-Von Abercron, Sophie-Marie; Pacheco, Daniel; Benito-Santano, Patricia; Marín, Patricia; Marqués, Silvia

    2016-01-01

    Although bacterial anaerobic degradation of mono-aromatic compounds has been characterized in depth, the degradation of polycyclic aromatic hydrocarbons (PAHs) such as naphthalene has only started to be understood in sulfate reducing bacteria, and little is known about the anaerobic degradation of PAHs in nitrate reducing bacteria. Starting from a series of environments which had suffered different degrees of hydrocarbon pollution, we used most probable number (MPN) enumeration to detect and quantify the presence of bacterial communities able to degrade several PAHs using nitrate as electron acceptor. We detected the presence of a substantial nitrate reducing community able to degrade naphthalene, 2-methylnaphthalene (2MN), and anthracene in some of the sites. With the aim of isolating strains able to degrade PAHs under denitrifying conditions, we set up a series of enrichment cultures with nitrate as terminal electron acceptor and PAHs as the only carbon source and followed the changes in the bacterial communities throughout the process. Results evidenced changes attributable to the imposed nitrate respiration regime, which in several samples were exacerbated in the presence of the PAHs. The presence of naphthalene or 2MN enriched the community in groups of uncultured and poorly characterized organisms, and notably in the Acidobacteria uncultured group iii1-8, which in some cases was only a minor component of the initial samples. Other phylotypes selected by PAHs in these conditions included Bacilli, which were enriched in naphthalene enrichments. Several nitrate reducing strains showing the capacity to grow on PAHs could be isolated on solid media, although the phenotype could not be reproduced in liquid cultures. Analysis of known PAH anaerobic degradation genes in the original samples and enrichment cultures did not reveal the presence of PAH-related nmsA-like sequences but confirmed the presence of bssA-like genes related to anaerobic toluene degradation

  1. Bioleaching of copper from waste printed circuit boards by bacterial consortium enriched from acid mine drainage.

    PubMed

    Xiang, Yun; Wu, Pingxiao; Zhu, Nengwu; Zhang, Ting; Liu, Wen; Wu, Jinhua; Li, Ping

    2010-12-15

    The objectives of this study were to evaluate the solubility of copper in waste printed circuit boards (PCBs) by bacterial consortium enriched from natural acid mine drainage, and to determine optimum conditions of bioleaching copper from PCBs. The results indicated that the extraction of copper was mainly accomplished indirectly through oxidation by ferric ions generated from ferrous ion oxidation bacteria. The initial pH and Fe(2+) concentration played an important role in copper extraction and precipitate formation. The leaching rate of copper was generally higher at lower PCB powder dosage. Moreover, a two-step process was extremely necessary for bacterial growth and obtaining an appropriate Fe(2+) oxidation rate; a suitable time when 6.25 g/L of Fe(2+) remained in the solution was suggested for adding PCB powder. The maximum leaching rate of copper was achieved 95% after 5 days under the conditions of initial pH 1.5, 9 g/L of initial Fe(2+), and 20 g/L of PCB powder. All findings demonstrated that copper could be efficiently solubilized from waste PCBs by using bacterial consortium, and the leaching period was shortened remarkably from about 12 days to 5 days.

  2. Geochemical and Temporal Influences on the Enrichment of Acidophilic Iron-Oxidizing Bacterial Communities

    PubMed Central

    Sheng, Yizhi; Bibby, Kyle; Grettenberger, Christen; Kaley, Bradley; Macalady, Jennifer L.; Wang, Guangcai

    2016-01-01

    ABSTRACT Two acid mine drainage (AMD) sites in the Appalachian bituminous coal basin were selected to enrich for Fe(II)-oxidizing microbes and measure rates of low-pH Fe(II) oxidation in chemostatic bioreactors. Microbial communities were enriched for 74 to 128 days in fed-batch mode, then switched to flowthrough mode (additional 52 to 138 d) to measure rates of Fe(II) oxidation as a function of pH (2.1 to 4.2) and influent Fe(II) concentration (80 to 2,400 mg/liter). Biofilm samples were collected throughout these operations, and the microbial community structure was analyzed to evaluate impacts of geochemistry and incubation time. Alpha diversity decreased as the pH decreased and as the Fe(II) concentration increased, coincident with conditions that attained the highest rates of Fe(II) oxidation. The distribution of the seven most abundant bacterial genera could be explained by a combination of pH and Fe(II) concentration. Acidithiobacillus, Ferrovum, Gallionella, Leptospirillum, Ferrimicrobium, Acidiphilium, and Acidocella were all found to be restricted within specific bounds of pH and Fe(II) concentration. Temporal distance, defined as the cumulative number of pore volumes from the start of flowthrough mode, appeared to be as important as geochemical conditions in controlling microbial community structure. Both alpha and beta diversities of microbial communities were significantly correlated to temporal distance in the flowthrough experiments. Even after long-term operation under nearly identical geochemical conditions, microbial communities enriched from the different sites remained distinct. While these microbial communities were enriched from sites that displayed markedly different field rates of Fe(II) oxidation, rates of Fe(II) oxidation measured in laboratory bioreactors were essentially the same. These results suggest that the performance of suspended-growth bioreactors for AMD treatment may not be strongly dependent on the inoculum used for reactor

  3. Environmental Enrichment Reduces the Likelihood of Alopecia in Adult C57BL/6J Mice

    PubMed Central

    Bechard, Allison; Meagher, Rebecca; Mason, Georgia

    2011-01-01

    Barbering (incessant grooming) is an abnormal behavior causing alopecia and commonly affects various strains of laboratory mice, including C57BL/6J. Barbering-induced alopecia is a potential symptom of brain impairment and can indicate a stressful environment. We compared alopecia prevalence and severity in mice housed in enriched or standard cages. Providing an enriched environment delayed the onset and reduced the prevalence and overall severity of alopecia in C57BL/6J mice. Husbandry methods that reduce adult alopecia are likely to promote the wellbeing of the animals. We suggest that environmental enrichment is a simple and economic way to reduce alopecia in mouse colonies. PMID:21439209

  4. Molecular imprinted polymer with cloned bacterial protein template enriches authentic target in cell extract.

    PubMed

    Zhao, Zhuo; Wang, Chunhong; Guo, Minjie; Shi, Linqi; Fan, Yunge; Long, Yi; Mi, Huaifeng

    2006-05-15

    Here we describe a new method for preparing a protein-imprinted polymer with a cloned bacterial protein template, which recognizes/adsorbs authentic target protein present at a relatively low level in cell extract. In this work, cloned pig cyclophilin 18 (pCyP18) was used as a template. The template protein was selectively assembled with memory molecules from their library, which consists of numerous limited length polymer chains with randomly distributed recognition sites and immobilizing sites. These assemblies of protein and memory molecules were adsorbed by porous polymeric beads and immobilized by cross-linking polymerization. After removing the template, binding sites that were complementary to the target protein in size, shape and the position of recognition groups were exposed, and their confirmation was preserved by the cross-linked structure. The synthesized imprinted polymer was used to adsorb authentic pCyP18 from cell extract, and its proportional content was enriched 300 times.

  5. Sequence element enrichment analysis to determine the genetic basis of bacterial phenotypes

    PubMed Central

    Lees, John A.; Vehkala, Minna; Välimäki, Niko; Harris, Simon R.; Chewapreecha, Claire; Croucher, Nicholas J.; Marttinen, Pekka; Davies, Mark R.; Steer, Andrew C.; Tong, Steven Y. C.; Honkela, Antti; Parkhill, Julian; Bentley, Stephen D.; Corander, Jukka

    2016-01-01

    Bacterial genomes vary extensively in terms of both gene content and gene sequence. This plasticity hampers the use of traditional SNP-based methods for identifying all genetic associations with phenotypic variation. Here we introduce a computationally scalable and widely applicable statistical method (SEER) for the identification of sequence elements that are significantly enriched in a phenotype of interest. SEER is applicable to tens of thousands of genomes by counting variable-length k-mers using a distributed string-mining algorithm. Robust options are provided for association analysis that also correct for the clonal population structure of bacteria. Using large collections of genomes of the major human pathogens Streptococcus pneumoniae and Streptococcus pyogenes, SEER identifies relevant previously characterized resistance determinants for several antibiotics and discovers potential novel factors related to the invasiveness of S. pyogenes. We thus demonstrate that our method can answer important biologically and medically relevant questions. PMID:27633831

  6. Environmental enrichment reduces brain damage in hydrocephalic immature rats.

    PubMed

    Catalão, Carlos Henrique Rocha; Shimizu, Glaucia Yuri; Tida, Jacqueline Atsuko; Garcia, Camila Araújo Bernardino; Dos Santos, Antonio Carlos; Salmon, Carlos Ernesto Garrido; Rocha, Maria José Alves; da Silva Lopes, Luiza

    2017-06-01

    We investigate the effects of environmental enrichment (EE) on morphological alterations in different brain structures of pup rats submitted to hydrocephalus condition. Hydrocephalus was induced in 7-day-old pup rats by injection of 20% kaolin into the cisterna magna. Ventricular dilatation and magnetization transfer to analyze myelin were assessed by magnetic resonance. Hydrocephalic and control rats exposed to EE (n = 10 per group) were housed in cages with a tunnel, ramp, and colored plastic balls that would emit sound when touched. The walls of the housing were decorated with colored adhesive tape. Moreover, tactile and auditory stimulation was performed daily throughout the experiment. Hydrocephalic and control rats not exposed to EE (n = 10 per group) were allocated singly in standard cages. All animals were weighed daily and exposed to open-field conditions every 2 days until the end of the experiment when they were sacrificed and the brains removed for histology and immunohistochemistry. Solochrome cyanine staining was performed to assess the thickness of the corpus callosum. The glial fibrillary acidic protein method was used to evaluate reactive astrocytes, and the Ki67 method to assess cellular proliferation in the subventricular zone. The hydrocephalic animals exposed to EE showed better performance in Open Field tests (p < 0.05), while presenting lower weight gain. In addition, these animals showed better myelination as revealed by magnetization transfer (p < 0.05). Finally, the EE group showed a reduction in reactive astrocytes by means of glial fibrillary acidic protein immunostaining and preservation of the proliferation potential of progenitor cells. The results suggest that EE can protect the developing brain against damaging effects caused by hydrocephalus.

  7. Aerobic De-Epoxydation of Trichothecene Mycotoxins by a Soil Bacterial Consortium Isolated Using In Situ Soil Enrichment

    PubMed Central

    He, Wei-Jie; Yuan, Qing-Song; Zhang, You-Bing; Guo, Mao-Wei; Gong, An-Dong; Zhang, Jing-Bo; Wu, Ai-Bo; Huang, Tao; Qu, Bo; Li, He-Ping; Liao, Yu-Cai

    2016-01-01

    Globally, the trichothecene mycotoxins deoxynivalenol (DON) and nivalenol (NIV) are among the most widely distributed mycotoxins that contaminate small grain cereals. In this study, a bacterial consortium, PGC-3, with de-epoxydation activity was isolated from soil by an in situ soil enrichment method. Screening of 14 soil samples that were sprayed with DON revealed that 4 samples were able to biotransform DON into de-epoxydized DON (dE-DON). Among these, the PGC-3 consortium showed the highest and most stable activity to biotransform DON into dE-DON and NIV into dE-NIV. PGC-3 exhibited de-epoxydation activity at a wide range of pH (5–10) and temperatures (20–37 °C) values under aerobic conditions. Sequential subculturing with a continued exposure to DON substantially reduced the microbial population diversity of this consortium. Analyses of the 16S rDNA sequences indicated that PGC-3 comprised 10 bacterial genera. Among these, one species, Desulfitobacterium, showed a steady increase in relative abundance, from 0.03% to 1.55% (a 52-fold increase), as higher concentrations of DON were used in the subculture media, from 0 to 500 μg/mL. This study establishes the foundation to further develop bioactive agents that can detoxify trichothecene mycotoxins in cereals and enables for the characterization of detoxifying genes and their regulation. PMID:27669304

  8. Enrichment and characterization of chlorinated organophosphate ester-degrading mixed bacterial cultures.

    PubMed

    Takahashi, Shouji; Kawashima, Koji; Kawasaki, Manami; Kamito, Jun; Endo, Yusuke; Akatsu, Kumiko; Horino, Sadatoshi; Yamada, Ryo-Hei; Kera, Yoshio

    2008-07-01

    Chlorinated organophosphate ester (OPE)-degrading enrichment cultures were obtained using tris(2-chloroethyl) phosphate (TCEP) or tris(1,3-dichloro-2-propyl) phosphate (TDCPP) as the sole phosphorus source. In cultures with 46 environmental samples, significant TCEP and TDCPP degradation was observed in 10 and 3 cultures, respectively, and successive subcultivation markedly increased their degradation rates. 67E and 45D stable enrichment cultures obtained with TCEP and TDCPP, respectively, completely degraded 20 muM of the respective compounds within 6 h and also the other, although the degradation rate of TCEP by 45D was relatively slow. We confirmed chloride ion generation on degradation in both cases and the generation of 2-chloroethanol (2-CE) and 1,3-dichloro-2-propanol (1,3-DCP) as metabolites of TCEP and TDCPP, respectively. 67E and 45D also showed dehalogenation ability toward 2-CE and 1,3-DCP, respectively. Addition of inorganic phosphate did not significantly influence their ability to degrade the chlorinated OPEs but markedly increased their dehalogenation ability, which was maximum at 0.2 mM of inorganic phosphate and decreased at a higher concentration. Denaturing gradient gel electrophoresis analysis showed that dominant bacteria in 67E are related to Acidovorax spp. and Sphingomonas spp. and those in 45D are Acidovorax spp., Aquabacterium spp., and Sphingomonas spp. This analysis indicated the relationship of the Sphingomonas- and Acidovorax-related bacteria with the cleavage of the phosphoester bond and dehalogenation, respectively, in both cultures. This is the first report on bacterial enrichment cultures capable of degrading both TCEP and TDCPP.

  9. Direct enrichment of perchlorate-reducing microbial community for efficient electroactive perchlorate reduction in biocathodes.

    PubMed

    Mieseler, Maren; Atiyeh, Mays N; Hernandez, Hector H; Ahmad, Farrukh

    2013-11-01

    Biological reduction of perchlorate (ClO₄⁻) has emerged as a promising solution for the removal of perchlorate in contaminated water and soils. In this work, we demonstrate a simple process to enrich perchlorate-reducing microbial communities separately using acetate as electron donor and the municipal aerobic membrane bioreactor sludge as inoculum. Inoculation of cathodes in microbial fuel cells (MFCs) with these enrichments, and further electrochemical enrichment at constant resistance operation of the MFCs, led to perchlorate-reducing biocathodes with peak reduction rates of 0.095 mM/day (2 mg/m²/day). Analysis of the microbial diversity of perchlorate-reducing biocathodes using PCR-DGGE revealed unique community profiles when compared to the denitrifying biocathode communities. More importantly, the total time taken for enrichment of the electroactive communities was reduced from several months reported previously in literature to less than a month in this work.

  10. A cationic cysteine-hydrazide as an enrichment tool for the mass spectrometric characterization of bacterial free oligosaccharides.

    PubMed

    Jang, Kyoung-Soon; Nani, Roger R; Kalli, Anastasia; Levin, Sergiy; Müller, Axel; Hess, Sonja; Reisman, Sarah E; Clemons, William M

    2015-08-01

    In Campylobacterales and related ε-proteobacteria with N-linked glycosylation (NLG) pathways, free oligosaccharides (fOS) are released into the periplasmic space from lipid-linked precursors by the bacterial oligosaccharyltransferase (PglB). This hydrolysis results in the same molecular structure as the oligosaccharide that is transferred to a protein to be glycosylated. This allowed for the general elucidation of the fOS-branched structures and monosaccharides from a number of species using standard enrichment and mass spectrometry methods. To aid characterization of fOS, hydrazide chemistry has often been used for chemical modification of the reducing part of oligosaccharides resulting in better selectivity and sensitivity in mass spectrometry; however, the removal of the unreacted reagents used for the modification often causes the loss of the sample. Here, we develop a more robust method for fOS purification and characterize glycostructures using complementary tandem mass spectrometry (MS/MS) analysis. A cationic cysteine hydrazide derivative was synthesized to selectively isolate fOS from periplasmic fractions of bacteria. The cysteine hydrazide nicotinamide (Cyhn) probe possesses both thiol and cationic moieties. The former enables reversible conjugation to a thiol-activated solid support, while the latter improves the ionization signal during MS analysis. This enrichment was validated on the well-studied Campylobacter jejuni by identifying fOS from the periplasmic extracts. Using complementary MS/MS analysis, we approximated data of a known structure of the fOS from Campylobacter concisus. This versatile enrichment technique allows for the exploration of a diversity of protein glycosylation pathways.

  11. Biodegradation of an Alicyclic Hydrocarbon by a Sulfate-Reducing Enrichment from a Gas Condensate-Contaminated Aquifer

    PubMed Central

    Rios-Hernandez, Luis A.; Gieg, Lisa M.; Suflita, Joseph M.

    2003-01-01

    We used ethylcyclopentane (ECP) as a model alicyclic hydrocarbon and investigated its metabolism by a sulfate-reducing bacterial enrichment obtained from a gas condensate-contaminated aquifer. The enrichment coupled the consumption of ECP with the stoichiometrically expected amount of sulfate reduced. During ECP biodegradation, we observed the transient accumulation of metabolite peaks by gas chromatography-mass spectrometry, three of which had identical mass spectrometry profiles. Mass-spectral similarities to analogous authentic standards allowed us to identify these metabolites as ethylcyclopentylsuccinic acids, ethylcyclopentylpropionic acid, ethylcyclopentylcarboxylic acid, and ethylsuccinic acid. Based on these findings, we propose a pathway for the degradation of this alicyclic hydrocarbon. Furthermore, a putative metabolite similar to ethylcyclopentylsuccinic acid was also found in samples of contaminated groundwater from the aquifer. However, no such finding was evident for samples collected from wells located upgradient of the gas condensate spill. Microbial community analysis of the ECP-degrading enrichment by denaturing gradient gel electrophoresis revealed the presence of at least three different organisms using universal eubacterial primers targeting 550 bp of the 16S rRNA gene. Based on sequence analysis, these organisms are phylogenetically related to the genera Syntrophobacter and Desulfotomaculum as well as a member of the Cytophaga-Flexibacter-Bacteroides group. The evidence suggests that alicyclic hydrocarbons such as ECP can be anaerobically activated by the addition to the double bond of fumarate to form alkylsuccinate derivatives under sulfate-reducing conditions and that the reaction occurs in the laboratory and in hydrocarbon-impacted environments. PMID:12514025

  12. Growth hormone reduces mortality and bacterial translocation in irradiated rats.

    PubMed

    Gómez-de-Segura, I A; Prieto, I; Grande, A G; García, P; Guerra, A; Mendez, J; De Miguel, E

    1998-01-01

    Growth hormone stimulates the growth of intestinal mucosa and may reduce the severity of injury caused by radiation. Male Wistar rats underwent abdominal irradiation (12 Gy) and were treated with either human growth hormone (hGH) or saline, and sacrificed at day 4 or 7 post-irradiation. Bacterial translocation, and the ileal mucosal thickness, proliferation, and disaccharidase activity were assessed. Mortality was 65% in irradiated animals, whereas hGH caused a decrement (29%, p < 0.05). Bacterial translocation was also reduced by hGH (p < 0.05). Treating irradiated rats with hGH prevented body weight loss (p < 0.05). Mucosal thickness increased faster in irradiated hGH-treated animals. The proliferative index showed an increment in hGH-treated animals (p < 0.05). Giving hGH to irradiated rats prevented decrease in sucrose activity, and increment in lactase activity. In conclusion, giving hGH to irradiated rats promotes the adaptative process of the intestine and acute radiation-related negative effects, including mortality, bacterial translocation, and weight loss.

  13. Tongue twisters: feeding enrichment to reduce oral stereotypy in giraffe.

    PubMed

    Fernandez, Loraine Tarou; Bashaw, Meredith J; Sartor, Richard L; Bouwens, Nichole R; Maki, Todd S

    2008-05-01

    Stereotypic behavior has been well-studied and documented in a variety of animals including primates, carnivores, and domesticated ungulates. However, very little information is known about stereotypic behavior of captive exotic ungulates. Giraffe have been found to perform a wide range of stereotypic behaviors. According to a survey of zoological institutions, oral stereotypies, specifically the licking of nonfood objects are the most prevalent stereotypic behaviors observed in giraffe. Their performance appears to be related to feeding and rumination and may be a result of the inability of a highly motivated feeding behavior pattern, tongue manipulation, to be successfully completed. To test this hypothesis, the indoor and outdoor feeders for three giraffe housed at Zoo Atlanta were modified to require the giraffe to perform more naturalistic and complex foraging behaviors. Data were collected using instantaneous scan sampling in both exhibit and holding areas. Our results showed that, for the giraffe that engaged in the highest rates of oral stereotypic behavior in the baseline, more complex feeders that required tongue use to access grain or alfalfa had the greatest effect on behavior. For the giraffe that performed low baseline rates of oral stereotypic behavior, adding slatted tops to the alfalfa feeders indoors virtually eliminated the behavior. Although some changes in ruminating and feeding behavior were observed, the decreases in stereotypic behavior were not associated with the changes in ruminating or feeding behavior. These results provide evidence for the hypothesis that oral stereotypy in herbivores can be reduced by encouraging giraffe to engage in more naturalistic foraging behavior.

  14. Intraspecific differences in bacterial responses to modelled reduced gravity

    NASA Technical Reports Server (NTRS)

    Baker, P. W.; Leff, L. G.

    2005-01-01

    AIMS: Bacteria are important residents of water systems, including those of space stations which feature specific environmental conditions, such as lowered effects of gravity. The purpose of this study was to compare responses with modelled reduced gravity of space station, water system bacterial isolates with other isolates of the same species. METHODS AND RESULTS: Bacterial isolates, Stenotrophomonas paucimobilis and Acinetobacter radioresistens, originally recovered from the water supply aboard the International Space Station (ISS) were grown in nutrient broth under modelled reduced gravity. Their growth was compared with type strains S. paucimobilis ATCC 10829 and A. radioresistens ATCC 49000. Acinetobacter radioresistens ATCC 49000 and the two ISS isolates showed similar growth profiles under modelled reduced gravity compared with normal gravity, whereas S. paucimobilis ATCC 10829 was negatively affected by modelled reduced gravity. CONCLUSIONS: These results suggest that microgravity might have selected for bacteria that were able to thrive under this unusual condition. These responses, coupled with impacts of other features (such as radiation resistance and ability to persist under very oligotrophic conditions), may contribute to the success of these water system bacteria. SIGNIFICANCE AND IMPACT OF THE STUDY: Water quality is a significant factor in many environments including the ISS. Efforts to remove microbial contaminants are likely to be complicated by the features of these bacteria which allow them to persist under the extreme conditions of the systems.

  15. Intraspecific differences in bacterial responses to modelled reduced gravity.

    PubMed

    Baker, P W; Leff, L G

    2005-01-01

    Bacteria are important residents of water systems, including those of space stations which feature specific environmental conditions, such as lowered effects of gravity. The purpose of this study was to compare responses with modelled reduced gravity of space station, water system bacterial isolates with other isolates of the same species. Bacterial isolates, Stenotrophomonas paucimobilis and Acinetobacter radioresistens, originally recovered from the water supply aboard the International Space Station (ISS) were grown in nutrient broth under modelled reduced gravity. Their growth was compared with type strains S. paucimobilis ATCC 10829 and A. radioresistens ATCC 49000. Acinetobacter radioresistens ATCC 49000 and the two ISS isolates showed similar growth profiles under modelled reduced gravity compared with normal gravity, whereas S. paucimobilis ATCC 10829 was negatively affected by modelled reduced gravity. These results suggest that microgravity might have selected for bacteria that were able to thrive under this unusual condition. These responses, coupled with impacts of other features (such as radiation resistance and ability to persist under very oligotrophic conditions), may contribute to the success of these water system bacteria. Water quality is a significant factor in many environments including the ISS. Efforts to remove microbial contaminants are likely to be complicated by the features of these bacteria which allow them to persist under the extreme conditions of the systems.

  16. Intraspecific differences in bacterial responses to modelled reduced gravity

    NASA Technical Reports Server (NTRS)

    Baker, P. W.; Leff, L. G.

    2005-01-01

    AIMS: Bacteria are important residents of water systems, including those of space stations which feature specific environmental conditions, such as lowered effects of gravity. The purpose of this study was to compare responses with modelled reduced gravity of space station, water system bacterial isolates with other isolates of the same species. METHODS AND RESULTS: Bacterial isolates, Stenotrophomonas paucimobilis and Acinetobacter radioresistens, originally recovered from the water supply aboard the International Space Station (ISS) were grown in nutrient broth under modelled reduced gravity. Their growth was compared with type strains S. paucimobilis ATCC 10829 and A. radioresistens ATCC 49000. Acinetobacter radioresistens ATCC 49000 and the two ISS isolates showed similar growth profiles under modelled reduced gravity compared with normal gravity, whereas S. paucimobilis ATCC 10829 was negatively affected by modelled reduced gravity. CONCLUSIONS: These results suggest that microgravity might have selected for bacteria that were able to thrive under this unusual condition. These responses, coupled with impacts of other features (such as radiation resistance and ability to persist under very oligotrophic conditions), may contribute to the success of these water system bacteria. SIGNIFICANCE AND IMPACT OF THE STUDY: Water quality is a significant factor in many environments including the ISS. Efforts to remove microbial contaminants are likely to be complicated by the features of these bacteria which allow them to persist under the extreme conditions of the systems.

  17. Relative performance properties of the ORNL Advanced Neutron Source Reactor with reduced enrichment fuels

    SciTech Connect

    Bretscher, M.M.; Deen, J.R.; Hanan, N.A.; Matos, J.E.; Mo, S.C.; Pond, R.B.; Travelli, A.; Woodruff, W.L.

    1994-12-31

    Three cores for the Advanced Neutron Source reactor, differing in size, enrichment, and uranium density in the fuel meat, have been analyzed. Performance properties of the reduced enrichment cores are compared with those of the HEU reference configuration. Core lifetime estimates suggest that none of these configurations will operate for the design goal of 17 days at 330 MW. With modes increases in fuel density and/or enrichment, however, the operating lifetimes of the HEU and MEU designs can be extended to the desired length. Achieving this lifetime with LEU fuel in any of the three studies cores, however, will require the successful development of denser fuels and/or structural materials with thermal neutron absorption cross sections substantially less than that of Al-6061. Relative to the HEU reference case, the peak thermal neutron flux in cores with reduced enrichment will be diminished by about 25--30%.

  18. Nonabsorbable Antibiotics Reduce Bacterial and Endotoxin Translocation in Hepatectomised Rats

    PubMed Central

    Kakkos, S. K.; Kirkilesis, J.; Scopa, C. D.; Arvaniti, A.; Alexandrides, T.

    1997-01-01

    There is increasing evidence that septic complications, occurring after major hepatectomies, may be caused by gram negative bacteria, translocating from the gut. We investigated in rats, the effect of extended hepatectomy on the structure and morphology of the intestinal mucosa as well as on the translocation of intestinal bacteria and endotoxins. We also examined the effect of nonabsorbable antibiotics on reducing the intestinal flora and consequently the phenomenon of translocation by administering neomycin sulphate and cefazoline. Hepatectomy was found to increase translocation, while administration of nonabsorbable antibiotics decreased it significantly. In addition, hepatectomy increased the aerobic cecal bacterial population, which normalised in the group receiving antibiotics. Among the histological parameters evaluated, villus height demonstrated a significant reduction after hepatectomy, while the number of villi per cm and the number of mitoses per crypt, remained unchanged. Our results indicate that administration of nonabsorbable antibiotics presents a positive effect on bacterial and endotoxin translocation after extended hepatectomy, and this may be related to reduction of colonic bacterial load as an intraluminal effect of antibiotics. PMID:9298382

  19. Impact of arachidonic acid enrichment of live rotifer prey on bacterial communities in rotifer and larval fish cultures.

    PubMed

    Seychelles, Laurent H; Doiron, Kim; Audet, Céline; Tremblay, Réjean; Pernet, Fabrice; Lemarchand, Karine

    2013-03-01

    Rotifers (Brachionus plicatilis), commonly used at first feeding in commercial fish hatcheries, carry a large bacteria load. Because they are relatively poor in essential fatty acids, it is common practice to enrich them with fatty acids, including arachidonic acid (AA). This study aims to determine whether prey enrichment with AA may act as a prebiotic and modify the microbial community composition either in AA-enriched rotifer cultures or in larval-rearing water using winter flounder (Pseudopleuronectes americanus) as a larval fish model. AA enrichment modified the bacterial community composition in both the rotifer culture tanks and the larval-rearing tanks. We observed an increase in the number of cultivable bacteria on TCBS (thiosulfate-citrate-bile salts-sucrose) agar, used as a proxy for the abundance of Vibrio sp. The results suggest that AA may also play an indirect role in larval health.

  20. Characterization of rumen bacterial strains isolated from enrichments of rumen content in the presence of propolis.

    PubMed

    de Aguiar, Sílvia Cristina; Zeoula, Lucia Maria; do Prado, Odimari Pricila Pires; Arcuri, Pedro Braga; Forano, Evelyne

    2014-11-01

    Propolis presents many biological properties, including antibacterial activities, and has been proposed as an additive in ruminant nutrition. Twenty bacterial strains, previously isolated from enrichments of Brazilian cow rumen contents in the presence of different propolis extracts (LLOS), were characterized using phenotyping and 16S rRNA identification. Seven strains were assigned to Streptococcus sp., most likely S. bovis, and were all degrading starch. One amylolytic lactate-utilizing strain of Selenomonas ruminantium was also found. Two strains of Clostridium bifermentans were identified and showed proteolytic activity. Two strains were assigned to Mitsuokella jalaludinii and were saccharolytic. One strain belonged to a Bacillus species and seven strains were affiliated with Escherichia coli. All of the 20 strains were able to use many sugars, but none of them were able to degrade the polysaccharides carboxymethylcellulose and xylans. The effect of three propolis extracts (LLOS B1, C1 and C3) was tested on the in vitro growth of four representative isolates of S. bovis, E. coli, M. jalaludinii and C. bifermentans. The growth of S. bovis, E. coli and M. jalaludinii was not affected by the three propolis extracts at 1 mg ml(-1). C. bifermentans growth was completely inhibited at this LLOS concentration, but this bacterium was partially resistant at lower concentrations. LLOS C3, with the lower concentration of phenolic compounds, was a little less inhibitory than B1 and C1 on this strain.

  1. Biodegradation of di-n-butyl phthalate by bacterial consortium LV-1 enriched from river sludge

    PubMed Central

    Li, Fangfang; Ruan, Xinling; Song, Jian; Lv, Lv; Chai, Liyuan; Yang, Zhihui; Luo, Lin

    2017-01-01

    A stable bacterial consortium (LV-1) capable of degrading di-n-butyl phthalate (DBP) was enriched from river sludge. Community analysis revealed that the main families of LV-1 are Brucellaceae (62.78%) and Sinobacteraceae (14.83%), and the main genera of LV-1 are Brucella spp. (62.78%) and Sinobacter spp. (14.83%). The optimal pH and temperature for LV-1 to degrade DBP were pH 6.0 and 30°C, respectively. Inoculum size influenced the degradation ratio when the incubation time was < 24 h. The initial concentration of DBP also influenced the degradation rates of DBP by LV-1, and the degradation rates ranged from 69.0–775.0 mg/l/d in the first 24 h. Degradation of DBP was best fitted by first-order kinetics when the initial concentration was < 300 mg/l. In addition, Cd2+, Cr6+, and Zn2+ inhibited DBP degradation by LV-1 at all considered concentrations, but low concentrations of Pb2+, Cu2+, and Mn2+ enhanced DBP degradation. The main intermediates (mono-ethyl phthalate [MEP], mono-butyl phthalate [MBP], and phthalic acid [PA]) were identified in the DBP degradation process, thus a new biochemical pathway of DBP degradation is proposed. Furthermore, LV-1 also degraded other phthalates with shorter ester chains (DMP, DEP, and PA). PMID:28542471

  2. Characterization of a Sulfate- and U(VI)-Reducing Enrichment from Area 3 of the Oak Ridge Field Research Center

    SciTech Connect

    Nyman, Jennifer L.; Gentile, Margaret; Criddle, Craig

    2005-04-18

    The objectives of this report are to: (1) develop a sulfate-reducing enrichment from the location of the Oak Ridge FRC Area 3 field experiment; (2) assess the capacity of the enrichment community for U(VI) reduction; (3) characterize the metabolic activity of the enrichment community; (4) kinetically model microbial growth and U(VI) reduction by the enrichment; and (5) investigate the enrichment's community structure.

  3. Development of antifouling surfaces to reduce bacterial attachment

    NASA Astrophysics Data System (ADS)

    Graham, Mary Viola

    Bacteria are exceptionally good at adhering to surfaces and forming complex structures known as biofilms. This process, known as biofouling, can cause problems for infrastructure (eg, clogging and damaging pipes), for the food industry (eg, contamination of processing surfaces and equipment, and for the medical industry (eg, contamination of indwelling medical devices). Accordingly, multiple strategies have been explored to combat biofouling, including chemical modification of surfaces, development of antibiotic coatings, and more recently, the use of engineered surface topography. When designed properly, engineered surface topographies can significantly reduce bacterial surface attachment, ultimately limiting surface colonization. In this work, we hypothesized that the morphology, size, spacing, and surface pre-treatment of topographical features should directly correlate with the size and shape of target organisms, in order to reduce biofouling. Topographical features with size and spacing from 0.25 to 2 mum were fabricated in silicone elastomer and tested against rod shaped bacteria with an average size of 0.5 x 2 mum and spherical bacteria (cocci) ranging from 0.5 - 1 μm in diameter. Antifouling properties of the different topographical features were tested in both static and flow-based assays, and under oxygen plasma-treated (hydrophilic) and untreated (hydrophobic) surface conditions. We found that surface pre-treatment universally affects the ability bacteria to attach to surfaces, while surface topography limits attachment in a manner dependent on the bacterial size/shape and the size/spacing of the topography.

  4. Polyurethane coatings release bioactive antibodies to reduce bacterial adhesion.

    PubMed

    Rojas, I A; Slunt, J B; Grainger, D W

    2000-01-03

    This study describes the formulation of a biomedical grade polyurethane hydrogel coating containing solid dispersed bioactive antibodies cast from an organic solvent onto a model polymer biomaterial substrate. A prepolymer dispersion in anhydrous isopropanol containing a uniformly distributed slurry of 22 microm sieved commercial lyophilized polyclonal pooled human immunoglobulin G (IgG) solids was coated onto polymer substrates by simple immersion. Maximum antibody release was approximately 50 microg/cm(2) from a 15% w/w IgG polymer coating. In vitro antimicrobial studies utilized Escherichia coli to compare performance of bare uncoated tubing, hydrogel-coated tubing with added aqueous phase antibodies, and antibody-dispersed hydrogel-coated tubing. Bacterial adhesion was reduced significantly (p<0.05) in the presence of antibodies with the greatest reduction seen with the antibody releasing coating. The presence of antibody also significantly enhanced the killing of the bacteria in an in vitro opsonophagocytic assay using freshly isolated blood neutrophils over 2 h indicating that antibody bioactivity is maintained. This controlled release polyurethane hydrogel coating imparts infection resistance by exploiting the low adhesive properties of the biomedical grade hydrogel and the intrinsic bioactive role of the antibodies to reduce bacterial adhesion and promote clearance via natural immune mechanisms.

  5. Assessing the effects of salmon farming seabed enrichment using bacterial community diversity and high-throughput sequencing.

    PubMed

    Dowle, Eddy; Pochon, Xavier; Keeley, Nigel; Wood, Susanna A

    2015-08-01

    Aquaculture is an extremely valuable and rapidly expanding sector of the seafood industry. The sediment below active aquaculture farms receives inputs of organic matter from uneaten food and faecal material and this has led to concerns related to environmental sustainability. The impacts of organic enrichment on macrobenthic infauna are well characterized; however, much less is known about effect on bacterial communities. In this study, sediment, macrobenthic infauna samples and environmental data were collected along an enrichment gradient radiating out from a Chinook salmon (Oncorhynchus tshawytscha) farm (Marlborough Sounds; New Zealand). DNA and RNA were extracted and 16S rRNA metabarcodes from bacterial communities characterized using high-throughput sequencing. Desulfobacterales dominated at the cage (DNA and RNA), and at sites 50 m (DNA and RNA) and 150 m (RNA) from the farm. In contrast, unclassified bacteria from the class Gammaproteobacteria were the most abundant taxa at control sites (625 and 4000 m). Pronounced differences among DNA and RNA samples occurred at the cage site where Desulfobacterales abundance was markedly higher in RNA samples. There were strong correlations between shifts in bacterial communities and total organic matter and redox. This suggests that bacterial composition is strongly influenced by organic enrichment, a trait that may make them useful for assessing impacts associated with aquaculture farms. © FEMS 2015. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  6. Interventions to reduce the bacterial load in recycled broiler litter.

    PubMed

    Vaz, C S L; Voss-Rech, D; de Avila, V S; Coldebella, A; Silva, V S

    2017-03-23

    Two experiments were undertaken to evaluate the bacterial load in recycled litter between broiler flocks following addition of quicklime (T1), windrowing (T2), shallow fermentation (T3), and control (no intervention, T4). The first experiment was developed in field conditions in which the broiler houses were accompanied by 6 consecutive flocks and the effect of the treatments was assessed on enterobacteria and aerobic mesophiles. The second experiment was conducted in an experimental broiler house with recycled litter for assessment of Salmonella Enteritidis phage type 4 (SE PT4). In the field study, T3 presented the best results in reducing enterobacteria in broiler litter in relation to the other treatments, with the highest reduction occurring in the first 3 flocks, tending to stabilization from the fourth flock onward for all the treatments assessed. From the third to sixth flocks, enterobacteria level at the end of the treatments (d 12) was lower than the average in the fresh litter, except in T4. All treatments reduced aerobic mesophiles throughout the flocks, where T2 showed the highest reduction. The percentage of dry matter in the broiler litter diminished in T4 and increased in T3 over the course of the flocks. In the second experiment, the drop in the SE PT4 level in the broiler litter first occurred in T2 and T3. However, all the treatments except for T4 eliminated SE PT4 within 12 d. The temperature of the broiler litter in T2 was higher in relation to the other treatments. The results show that litter treatment prior to reutilization by the successive broiler flock is required to reduce the level of residual bacteria. The fermentative treatments (T2 and T3) were found to be superior to the others in terms of reducing the bacterial load, with shallow fermentation standing out with the highest reduction of enterobacteria and equivalent SE PT4 elimination when compared to windrowing.

  7. Cooking rice in excess water reduces both arsenic and enriched vitamins in the cooked grain.

    PubMed

    Gray, Patrick J; Conklin, Sean D; Todorov, Todor I; Kasko, Sasha M

    2016-01-01

    This paper reports the effects of rinsing rice and cooking it in variable amounts of water on total arsenic, inorganic arsenic, iron, cadmium, manganese, folate, thiamin and niacin in the cooked grain. We prepared multiple rice varietals both rinsed and unrinsed and with varying amounts of cooking water. Rinsing rice before cooking has a minimal effect on the arsenic (As) content of the cooked grain, but washes enriched iron, folate, thiamin and niacin from polished and parboiled rice. Cooking rice in excess water efficiently reduces the amount of As in the cooked grain. Excess water cooking reduces average inorganic As by 40% from long grain polished, 60% from parboiled and 50% from brown rice. Iron, folate, niacin and thiamin are reduced by 50-70% for enriched polished and parboiled rice, but significantly less so for brown rice, which is not enriched.

  8. Co-occurrence of Methanosarcina mazei and Geobacteraceae in an iron (III)-reducing enrichment culture

    PubMed Central

    Zheng, Shiling; Zhang, Hongxia; Li, Ying; Zhang, Hua; Wang, Oumei; Zhang, Jun; Liu, Fanghua

    2015-01-01

    Methanosaeta harundinacea and Methanosarcina barkeri, known as classic acetoclastic methanogens, are capable of directly accepting electrons from Geobacter metallireducens for the reduction of carbon dioxide to methane, having been revealed as direct interspecies electron transfer (DIET) in the laboratory co-cultures. However, whether their co-occurrences are ubiquitous in the iron (III)-reducing environments and the other species of acetoclastic methanogens such as Methanosarcina mazei are capable of DIET are still unknown. Instead of initiating the co-cultures with pure cultures, two-step cultivation was employed to selectively enrich iron (III)-reducing microorganisms in a coastal gold mining river, Jiehe River, with rich iron content in the sediments. First, iron (III) reducers including Geobacteraceae were successfully enriched by 3-months successive culture on amorphous Fe(III) oxides as electron acceptor and acetate as electron donor. High-throughput Illumina sequencing, terminal restriction fragment length polymorphism (T-RFLP) and clone library analysis based on 16S rRNA genes revealed that the enrichment cultures actively contained the bacteria belong to Geobacteraceae and Bacilli, exclusively dominated by the archaea belong to Methanosarcinaceae. Second, the enrichment cultures including methanogens and Geobacteraceae were transferred with ethanol as alternative electron donor. Remarkably, aggregates were successively formed in the enrichments after three transfers. The results revealed by RNA-based analysis demonstrate that the co-occurrence of Methanosarcina mazei and Geobacteraceae in an iron (III)-reducing enrichment culture. Furthermore, the aggregates, as close physical contact, formed in the enrichment culture, indicate that DIET could be a possible option for interspecies electron transfer in the aggregates. PMID:26441876

  9. Utilizing intake-air oxygen-enrichment technology to reduce cold- phase emissions

    SciTech Connect

    Poola, R.B.; Ng, H.K.; Sekar, R.R.; Baudino, J.H.; Colucci, C.P.

    1995-12-31

    Oxygen-enriched combustion is a proven, serious considered technique to reduce exhaust hydrocarbons (HC) and carbon monoxide (CO) emissions from automotive gasoline engines. This paper presents the cold-phase emissions reduction results of using oxygen-enriched intake air containing about 23% and 25% oxygen (by volume) in a vehicle powered by a spark-ignition (SI) engine. Both engineout and converter-out emissions data were collected by following the standard federal test procedure (FTP). Converter-out emissions data were also obtained employing the US Environmental Protection Agency`s (EPA`s) ``Off-Cycle`` test. Test results indicate that the engine-out CO emissions during the cold phase (bag 1) were reduced by about 46 and 50%, and HC by about 33 and 43%, using nominal 23 and 25% oxygen-enriched air compared to ambient air (21% oxygen by volume), respectively. However, the corresponding oxides of nitrogen (NO{sub x}) emissions were increased by about 56 and 79%, respectively. Time-resolved emissions data indicate that both HC and CO emissions were reduced considerably during the initial 127 s of the cold-phase FTP, without any increase in NO, emissions in the first 25 s. Hydrocarbon speciation results indicate that all major toxic pollutants, including ozone-forming specific reactivity factors, such as maximum incremental reactivity (NUR) and maximum ozone incremental reactivity (MOIR), were reduced considerably with oxygen-enrichment. Based on these results, it seems that using oxygen-enriched intake air during the cold-phase FTP could potentially reduce HC and CO emissions sufficiently to meet future emissions standards. Off-cycle, converter-out, weighted-average emissions results show that both HC and CO emissions were reduced by about 60 to 75% with 23 or 25% oxygen-enrichment, but the accompanying NO{sub x}, emissions were much higher than those with the ambient air.

  10. Cranberry derived proanthocyanidins reduce bacterial adhesion to selected biomaterials.

    PubMed

    Eydelnant, Irwin Adam; Tufenkji, Nathalie

    2008-09-16

    Catheter associated urinary tract infections (CAUTI) linked with the uropathogens Escherichia coli (E. coli) and Enterococcus faecalis (E. faecalis) account for the majority of nosocomial infections acquired in the clinical environment. Because these infections develop following initial adhesion of the bacterial pathogens to the catheter surface, there is increased interest in developing effective methods to inhibit attachment of cells to biomaterials used in the manufacture of indwelling devices. High molecular weight proanthocyanidins (PAC) extracted from the North American cranberry (Vaccinium macrocarpon) were examined for their potential to reduce the initial adhesion of uropathogenic bacteria (E. coli CFT073 and E. faecalis 29212) to two model biomaterials, poly(vinyl chloride) (PVC) and polytetrafluoroethylene (PTFE). Well-controlled experiments conducted in a parallel-plate flow chamber (PPFC) demonstrated decreased attachment of both bacteria to PVC and PTFE when either the bacteria, biomaterial or both surfaces were treated with PAC. Most significant inhibition of bacterial adhesion was observed for the condition where both the bacteria and biomaterial surfaces were coated with PAC. Additional experiments conducted with nonbiological model particles demonstrate comparable extents of adhesion inhibition, supporting a nonbiospecific mechanism of PAC action. The results of this study are promising for the implementation of PAC in the clinical milieu for prevention of device associated infection as the proposed functional modification is independent of antibacterial mechanisms that may give rise to resistant strains.

  11. Acidification of calf bedding reduces fly development and bacterial abundance.

    PubMed

    Calvo, M S; Gerry, A C; McGarvey, J A; Armitage, T L; Mitloehner, F M

    2010-03-01

    Environmental stressors, such as high fly density, can affect calf well-being. Sodium bisulfate (SBS) is an acidifier that reduces the pH of flooring and bedding, creating a medium that neither bacteria nor immature flies (also known as larvae or maggots) can thrive in. Two experiments were conducted to investigate the application of SBS to a mixture of rice hull calf bedding and calf slurry (BED) to reduce house fly (Musca domestica L.) larval density and the abundance of bacteria. In experiment 1, dish pans containing 1L of BED and 3,000 house fly eggs were treated with SBS at concentrations of 0, 8.9, 17.7, and 26.5g of SBS/0.05m(2) of BED (CON, LOW, MED, and HIGH, respectively), with each SBS concentration applied to 4 individual pans (16 pans total). Reapplication of the same SBS concentrations in each pan occurred 3 times/wk throughout the 23-d trial. Larval house fly survival was significantly reduced in all pans with SBS relative to CON pans, with lowest survival rates in the MED and HIGH pans (99% and 100% reduction, respectively). The mean pH for each treatment was inversely related to the SBS concentration. In experiment 2, pans containing 1L of BED and 3,000 house fly eggs were treated with either 0g of SBS (CON), 8.9g of SBS/0.05m(2) of BED with reapplication of the acidifier 3 times/wk (SB3x), or 8.9g of SBS/0.05m(2) of BED applied only once at 48h before the end of the 8 d-trial (SB48). Larval house fly survival and bacterial concentrations were reduced (90% larval reduction and 68% bacterial reduction) in the SB3x treatment relative to the CON. Mean pH was also reduced in SB3x pans relative to CON or SB48 pans. Overall, acidification of calf BED using the acidifier SBS resulted in a reduction of bacteria and house fly larval survival. This form of fly control might be expected to reduce adult fly production and, therefore, fly-related stress in calves.

  12. Molecular Detection of Culture-Confirmed Bacterial Bloodstream Infections with Limited Enrichment Time

    PubMed Central

    Moore, Miranda S.; McCann, Chase D.

    2013-01-01

    Conventional blood culturing using automated instrumentation with phenotypic identification requires a significant amount of time to generate results. This study investigated the speed and accuracy of results generated using PCR and pyrosequencing compared to the time required to obtain Gram stain results and final culture identification for cases of culture-confirmed bloodstream infections. Research and physician-ordered blood cultures were drawn concurrently. Aliquots of the incubating research blood culture fluid were removed hourly between 5 and 8 h, at 24 h, and again at 5 days. DNA was extracted from these 6 time point aliquots and analyzed by PCR and pyrosequencing for bacterial rRNA gene targets. These results were then compared to those of the physician-ordered blood culture. PCR and pyrosequencing accurately identified 92% of all culture-confirmed cases after a mean enrichment time of 5.8 ± 2.9 h. When the time needed to complete sample processing was included for PCR and pyrosequencing protocols, the molecular approach yielded results in 11.8 ± 2.9 h compared to means of 27.9 ± 13.6 h to obtain the Gram stain results and 81.6 ± 24.0 h to generate the final culture-based identification. The molecular approach enabled accurate detection of most bacteria present in incubating blood culture bottles on average about 16 h sooner than Gram stain results became available and approximately 3 days sooner than the phenotypic identification was entered in the Laboratory Information System. If implemented, this more rapid molecular approach could minimize the number of doses of unnecessary or ineffective antibiotics administered to patients. PMID:23985915

  13. Combining Quantitative Genetic Footprinting and Trait Enrichment Analysis to Identify Fitness Determinants of a Bacterial Pathogen

    PubMed Central

    Wiles, Travis J.; Norton, J. Paul; Russell, Colin W.; Dalley, Brian K.; Fischer, Kael F.; Mulvey, Matthew A.

    2013-01-01

    Strains of Extraintestinal Pathogenic Escherichia c oli (ExPEC) exhibit an array of virulence strategies and are a major cause of urinary tract infections, sepsis and meningitis. Efforts to understand ExPEC pathogenesis are challenged by the high degree of genetic and phenotypic variation that exists among isolates. Determining which virulence traits are widespread and which are strain-specific will greatly benefit the design of more effective therapies. Towards this goal, we utilized a quantitative genetic footprinting technique known as transposon insertion sequencing (Tn-seq) in conjunction with comparative pathogenomics to functionally dissect the genetic repertoire of a reference ExPEC isolate. Using Tn-seq and high-throughput zebrafish infection models, we tracked changes in the abundance of ExPEC variants within saturated transposon mutant libraries following selection within distinct host niches. Nine hundred and seventy bacterial genes (18% of the genome) were found to promote pathogen fitness in either a niche-dependent or independent manner. To identify genes with the highest therapeutic and diagnostic potential, a novel Trait Enrichment Analysis (TEA) algorithm was developed to ascertain the phylogenetic distribution of candidate genes. TEA revealed that a significant portion of the 970 genes identified by Tn-seq have homologues more often contained within the genomes of ExPEC and other known pathogens, which, as suggested by the first axiom of molecular Koch's postulates, is considered to be a key feature of true virulence determinants. Three of these Tn-seq-derived pathogen-associated genes—a transcriptional repressor, a putative metalloendopeptidase toxin and a hypothetical DNA binding protein—were deleted and shown to independently affect ExPEC fitness in zebrafish and mouse models of infection. Together, the approaches and observations reported herein provide a resource for future pathogenomics-based research and highlight the diversity of

  14. Occurrence and enrichment of 'bacterial sherpas': climb to sustainability in wastewater treatment.

    PubMed

    Arnaldos, M; Pagilla, K R

    2015-01-01

    The paper presents research on hemoglobin (Hb)-expressing bacteria in biological wastewater treatment systems. The outcome(s) will greatly reduce the aeration needs of wastewater treatment plants (WWTPs) and provide insight into emerging biological nitrogen removal processes using low dissolved oxygen (DO) conditions. In anthropogenic terms, the bacteria that express Hb could be considered as 'bacterial sherpas' that can function under low DO conditions. Hitherto, this functionality of bacteria has not been realized due to the initial response of the aerobic treatment stage: namely, morphology change by bacteria to filamentous forms to overcome oxygen mass transfer limitations causing bulking/foaming and nitrification inhibition. There is evidence, however, of the potential expression of Hb proteins by activated sludge (AS) bacteria. First, bacteria known to possess genes coding Hb proteins have been isolated from AS systems. Secondly, there is evidence that WWTPs are able to operate their biological processes at low DO without sludge bulking or incomplete nitrification. Our research has focused on nitrifying systems and has shown that this is due to prolonged operation at low DO conditions (0.1 mg O2/L), which allows sufficient time for bacterial acclimation. Additionally, it has been shown that enhanced Hb expression is linked to acclimation to low DO conditions.

  15. The current state of the Russian reduced enrichment research reactors program

    SciTech Connect

    Aden, V.G.; Kartashov, E.F.; Lukichev, V.A.

    1997-08-01

    During the last year after the 16-th International Conference on Reducing Fuel Enrichment in Research Reactors held in October, 1993 in Oarai, Japan, the conclusive stage of the Program on reducing fuel enrichment (to 20% in U-235) in research reactors was finally made up in Russia. The Program was started late in 70th and the first stage of the Program was completed by 1986 which allowed to reduce fuel enrichment from 80-90% to 36%. The completion of the Program current stage, which is counted for 5-6 years, will exclude the use of the fuel enriched by more than 20% from RF to other countries such as: Poland, Czeck Republick, Hungary, Roumania, Bulgaria, Libya, Viet-Nam, North Korea, Egypt, Latvia, Ukraine, Uzbekistan and Kazakhstan. In 1994 the Program, approved by RF Minatom authorities, has received the status of an inter-branch program since it was admitted by the RF Ministry for Science and Technical Policy. The Head of RF Minatom central administrative division N.I.Ermakov was nominated as the Head of the Russian Program, V.G.Aden, RDIPE Deputy Director, was nominated as the scientific leader. The Program was submitted to the Commission for Scientific, Technical and Economical Cooperation between USA and Russia headed by Vice-President A. Gore and Prime Minister V. Chemomyrdin and was given support also.

  16. Sensory evaluation of dairy supplements enriched with reduced iron, ferrous sulfate or ferrous fumarate.

    PubMed

    Morales, Josefina C; Sánchez-Vargas, Elena; García-Zepeda, Rodrigo; Villalpando, Salvador

    2015-01-01

    To determine the degree of liking of the Oportunidades programme dietary supplements (DS)--purees and beverages--added with different iron salts (IS): reduced iron (RI), ferrous sulphate (FS) or ferrous fumarate (FF) during 24 weeks of storage. The DS were evaluated through a hedonic scale for aroma, flavour and colour attributes; at time zero and every eight weeks, each panel member evaluated three DS with same flavour and presentation but different IS. Seventy women participated as panel members. The chocolate and banana DS exhibited a change in preference by colour and flavour due to storage. DS with FS or RI showed the least preference by flavour and colour in the context of the three IS considered. The chocolate and neutral DS enriched with FS changed their colour and flavour. DS were, in general, well-liked; nonetheless, for purees enriched with FS and for beverages enriched with RI, the less-liked attributes were colour and flavour.

  17. Biodegradation of Various Aromatic Compounds by Enriched Bacterial Cultures: Part A-Monocyclic and Polycyclic Aromatic Hydrocarbons.

    PubMed

    Oberoi, Akashdeep Singh; Philip, Ligy; Bhallamudi, S Murty

    2015-08-01

    Present study focused on the screening of bacterial consortium for biodegradation of monocyclic aromatic hydrocarbon (MAH) and polycyclic aromatic hydrocarbons (PAHs). Target compounds in the present study were naphthalene, acenaphthene, phenanthrene (PAHs), and benzene (MAH). Microbial consortia enriched with the above target compounds were used in screening experiments. Naphthalene-enriched consortium was found to be the most efficient consortium, based on its substrate degradation rate and its ability to degrade other aromatic pollutants with significantly high efficiency. Substrate degradation rate with naphthalene-enriched culture followed the order benzene > naphthalene > acenaphthene > phenanthrene. Chryseobacterium and Rhodobacter were discerned as the predominant species in naphthalene-enriched culture. They are closely associated to the type strain Chryseobacterium arthrosphaerae and Rhodobacter maris, respectively. Single substrate biodegradation studies with naphthalene (PAH) and benzene (MAH) were carried out using naphthalene-enriched microbial consortium (NAPH). Phenol and 2-hydroxybenzaldehyde were identified as the predominant intermediates during benzene and naphthalene degradation, respectively. Biodegradation of toluene, ethyl benzene, xylene, phenol, and indole by NAPH was also investigated. Monod inhibition model was able to simulate biodegradation kinetics for benzene, whereas multiple substrate biodegradation model was able to simulate biodegradation kinetics for naphthalene.

  18. Diverse metal reduction and nano- mineral formation by metal-reducing bacteria enriched from inter-tidal flat sediments

    NASA Astrophysics Data System (ADS)

    Kim, Y.; Park, B.; Seo, H.; Roh, Y.

    2009-12-01

    Dissimilatory metal-reducing bacteria utilize diverse metal oxides as electron acceptors and couple this microbial metal reduciton to growth. However, the microbe-metal interactions playing important roles in the metal geochemistry and organic matter degradation in the tidal flat sediments have not been uncovered enough to employ in various environmental and industrial applications. The objective of this study was to examine biomineralization and bioremediation by the facultative metal-reducing bacteria isolated from the inter-tidal flat sediments in southwestern of Korea. 16S-rRNA analysis showed bacterial consortium mainly consists of genus of Clostridium sp. The enriched bacteria were capable of reducing diverse metals such as iron oxide, maganese oxide, Cr(VI) and Se(VI) during glucose fermentation process at room temperature. The bacteria reduced highly toxic and reactive elements such as Cr(VI) and Se(VI) to Cr(III) and Se(0). The results showed that microbial processes induced transformation from toxic states of heavy metals to less toxic and mobile states in natural environments. Andthe bacteria also reduced iron oxyhydroxide such as ferrihydrite and akaganeite (β-FeOOH) and formed nanometer-sized magnetite (Fe3O4). This study indicates microbial processes not only can be used for bioremediation of inorganic contaminants existing in the marine environments, but also form the magnetite nanoparticles which are exhibit superparamagnetic properties that can be useful for relevant medical and industrial applications.

  19. Bacterial mobilization and transport through manure enriched soils: Experiment and modeling.

    PubMed

    Sepehrnia, N; Memarianfard, L; Moosavi, A A; Bachmann, J; Guggenberger, G; Rezanezhad, F

    2017-10-01

    A precise evaluation of bacteria transport and mathematical investigations are useful for best management practices in agroecosystems. In this study, using laboratory experiments and modeling approaches, we assess the transport of bacteria released from three types of manure (cow, sheep, and poultry) to find the importance of the common manures in agricultural activities in soil and water pollution. Thirty six intact soil columns with different textures (sandy, loamy, and silty clay loam) were sampled. Fecal coliform leaching from layers of the manures on the soil surface was conducted under steady-state saturated flow conditions at 20 °C for up to four Pore Volumes (PVs). Separate leaching experiments were conducted to obtain the initial concentrations of bacteria released from the manures (Co). Influent (Co) and effluent (C) bacteria concentrations were measured by the plate-count method and the normalized concentrations (C/C0) were plotted versus PV representing the breakthrough curves (BTCs). Transport parameters were predicted using the attachment/detachment model (two-kinetic site) in HYDRUS-1D. Simulations fitted well the experimental data (R(2) = 0.50-0.96). The attachment, detachment, and straining coefficients of bacteria were more influenced by the soils treated with cow manure compared to the sheep and poultry manures. Influent curves of fecal coliforms from the manures (leached without soil) illustrated that the poultry manure had the highest potential to pollute the effluent water from the soils in term of concentration, but the BTCs and simulated data related to the treated soils illustrated that the physical shape of cow manure was more important to both straining and detachment of bacteria back into the soil solution. Detachment trends of bacteria were observed through loam and silty clay loam soils treated with cow manure compared to the cow manure enriched sandy soil. We conclude that management strategies must specifically minimize the

  20. Proceedings of the 1990 International Meeting on Reduced Enrichment for Research and Test Reactors

    SciTech Connect

    Not Available

    1993-07-01

    The global effort to reduce, and possibly, eliminate the international traffic in highly-enriched uranium caused by its use in research reactors requires extensive cooperation and free exchange of information among all participants. To foster this free exchange of information, the Reduced Enrichment Research and Test Reactor (RERTR) Program, at Argonne National Laboratory, sponsored this meeting as the thirteenth of a series which began in 1978. The common effort brought together, past, a large number of specialists from many countries. On hundred twenty-three participants from 26 countries, including scientists, reactor operators, and personnel from commercial fuel suppliers, research centers, and government organizations, convened in Newport, Rhode Island to discuss their results, their activities, and their plans relative to converting research reactors to low-enriched fuels. As more and more reactors convert to the use of low-enriched uranium, the emphasis of our effort has begun to shift from research and development to tasks more directly related to implementation of the new fuels and technologies that have been developed, and to refinements of those fuels and technologies. It is appropriate, for this reason, that the emphasis of this meeting was placed on safety and on conversion experiences. This individual papers in this report have been cataloged separately.

  1. Irradiation testing of full-sized, reduced-enrichment fuel elements

    SciTech Connect

    Snelgrove, J.L.; Copeland, G.L.

    1983-01-01

    The current status of the irradiation testing of full-sized, reduced-enrichment fuel elements and fuel rods under the US Reduced Enrichment Research and Test Reactor Program is reported. Being tested are UAl/sub x/-Al, U/sub 3/O/sub 8/-Al, U/sub 3/Si/sub 2/-Al, and U/sub 3/Si-Al dispersion fuels and UZrH/sub x/ (TRIGA) fuel at uranium densities in the fuel meat ranging from 1.7 to 6.0 Mg/m/sup 3/. Generally good performance has been experienced to date. Some preliminary results of postirradiation examinations are also included. A whole-core demonstration in the Oak Ridge Research Reactor is planned. Some details of this demonstration are provided.

  2. Novel method for identifying bacterial mutants with reduced epiphytic fitness

    SciTech Connect

    Lindow, S.E. )

    1993-05-01

    Leaf surfaces are a habitat for large population of diverse bacteria which, in turn, can have numerous effects on the plants on which they live. Such bacteria are considered distinct from other plant-associated bacteria and have probably acquired adaptations which allow them to tolerate the physical and chemical environments found on leaves. Some bacterial traits, such as motility or UV irradiation tolerance, are unambiguously important in epiphytic fitness. However, novel traits may condition bacterial growth or survival on leaves. The author of this study has adapted a tube ice nucleation assay to allow differentiation of mutants of an ice nucleation-active bacterial strain that colonizes leave. The study describes a technique for rapid identification of bacterial mutants with quantitatively different population sized in a natural habitat based on the measurement of ice nucleus production. 41 refs., 6 figs., 2 tabs.

  3. Changes in epiphytic bacterial communities of intertidal seaweeds modulated by host, temporality, and copper enrichment.

    PubMed

    Hengst, Martha B; Andrade, Santiago; González, Bernardo; Correa, Juan A

    2010-08-01

    This study reports on the factors involved in regulating the composition and structure of bacterial communities epiphytic on intertidal macroalgae, exploring their temporal variability and the role of copper pollution. Culture-independent, molecular approaches were chosen for this purpose and three host species were used as models: the ephemeral Ulva spp. (Chlorophyceae) and Scytosiphon lomentaria (Phaeophyceae) and the long-living Lessonia nigrescens (Phaeophyceae). The algae were collected from two coastal areas in Northern Chile, where the main contrast was the concentration of copper in the seawater column resulting from copper-mine waste disposals. We found a clear and strong effect in the structure of the bacterial communities associated with the algal species serving as host. The structure of the bacterial communities also varied through time. The effect of copper on the structure of the epiphytic bacterial communities was significant in Ulva spp., but not on L. nigrescens. The use of 16S rRNA gene library analysis to compare bacterial communities in Ulva revealed that they were composed of five phyla and six classes, with approximately 35 bacterial species, dominated by members of Bacteroidetes (Cytophaga-Flavobacteria-Bacteroides) and α-Proteobacteria, in both non-polluted and polluted sites. Less common groups, such as the Verrucomicrobiae, were exclusively found in polluted sites. This work shows that the structure of bacterial communities epiphytic on macroalgae is hierarchically determined by algal species > temporal changes > copper levels.

  4. Metal nanoparticles reduce bacterial contamination of experimental purulent wounds.

    PubMed

    Babushkina, I V; Mamontova, I A; Gladkova, E V

    2015-03-01

    Bacterial contamination of experimental purulent wound in rats treated by local applications of suspension of copper and zinc nanoparticles and a combined drug based on chitosan and copper and zinc nanoparticles was evaluated. Applications of copper nanoparticle suspension and combined drug with copper and zinc nanoparticles and chitosan led to rapid elimination of the bacterial contaminant. Antibacterial activity of zinc nanoparticles was less pronounced, but the effect also differed significantly from the reference group.

  5. Temperature-tolerant COLD-PCR reduces temperature stringency and enables robust mutation enrichment.

    PubMed

    Castellanos-Rizaldos, E; Liu, Pingfang; Milbury, Coren A; Guha, Minakshi; Brisci, Angela; Cremonesi, Laura; Ferrari, Maurizio; Mamon, Harvey; Makrigiorgos, G Mike

    2012-07-01

    Low-level mutations in clinical tumor samples often reside below mutation detection limits, thus leading to false negatives that may impact clinical diagnosis and patient management. COLD-PCR (coamplification at lower denaturation temperature PCR) is a technology that magnifies unknown mutations during PCR, thus enabling downstream mutation detection. However, a practical difficulty in applying COLD-PCR has been the requirement for strict control of the denaturation temperature for a given sequence, to within ±0.3 °C. This requirement precludes simultaneous mutation enrichment in sequences of substantially different melting temperature (T(m)) and limits the technique to a single sequence at a time. We present a temperature-tolerant (TT) approach (TT-COLD-PCR) that reduces this obstacle. We describe thermocycling programs featuring a gradual increase of the denaturation temperature during COLD-PCR. This approach enabled enrichment of mutations when the cycling achieves the appropriate critical denaturation temperature of each DNA amplicon that is being amplified. Validation was provided for KRAS (v-Ki-ras2 Kirsten rat sarcoma viral oncogene homolog) and TP53 (tumor protein p53) exons 6-9 by use of dilutions of mutated DNA, clinical cancer samples, and plasma-circulating DNA. A single thermocycling program with a denaturation-temperature window of 2.5-3.0 °C enriches mutations in all DNA amplicons simultaneously, despite their different T(m)s. Mutation enrichments of 6-9-fold were obtained with TT-full-COLD-PCR. Higher mutation enrichments were obtained for the other 2 forms of COLD-PCR, fast-COLD-PCR, and ice-COLD-PCR. Low-level mutations in diverse amplicons with different T(m)s can be mutation enriched via TT-COLD-PCR provided that their T(m)s fall within the denaturation-temperature window applied during amplification. This approach enables simultaneous enrichment of mutations in several amplicons and increases significantly the versatility of COLD-PCR.

  6. Spatial Dependence of Reduced Sulfur in Everglades Dissolved Organic Matter Controlled by Sulfate Enrichment.

    PubMed

    Poulin, Brett A; Ryan, Joseph N; Nagy, Kathryn L; Stubbins, Aron; Dittmar, Thorsten; Orem, William; Krabbenhoft, David P; Aiken, George R

    2017-04-04

    Sulfate inputs to the Florida Everglades stimulate sulfidic conditions in freshwater wetland sediments that affect ecological and biogeochemical processes. An unexplored implication of sulfate enrichment is alteration of the content and speciation of sulfur in dissolved organic matter (DOM), which influences the reactivity of DOM with trace metals. Here, we describe the vertical and lateral spatial dependence of sulfur chemistry in the hydrophobic organic acid fraction of DOM from unimpacted and sulfate-impacted Everglades wetlands using X-ray absorption spectroscopy and ultrahigh-resolution mass spectrometry. Spatial variation in DOM sulfur content and speciation reflects the degree of sulfate enrichment and resulting sulfide concentrations in sediment pore waters. Sulfur is incorporated into DOM predominantly as highly reduced species in sulfidic pore waters. Sulfur-enriched DOM in sediment pore waters exchanges with overlying surface waters and the sulfur likely undergoes oxidative transformations in the water column. Across all wetland sites and depths, the total sulfur content of DOM correlated with the relative abundance of highly reduced sulfur functionality. The results identify sulfate input as a primary determinant on DOM sulfur chemistry to be considered in the context of wetland restoration and sulfur and trace metal cycling.

  7. Spatial dependence of reduced sulfur in Everglades dissolved organic matter controlled by sulfate enrichment

    USGS Publications Warehouse

    Poulin, Brett A.; Ryan, Joseph N.; Nagy, Kathryn L.; Stubbins, Aron; Dittmar, Thorsten; Orem, William H.; Krabbenhoft, David P.; Aiken, George R.

    2017-01-01

    Sulfate inputs to the Florida Everglades stimulate sulfidic conditions in freshwater wetland sediments that affect ecological and biogeochemical processes. An unexplored implication of sulfate enrichment is alteration of the content and speciation of sulfur in dissolved organic matter (DOM), which influences the reactivity of DOM with trace metals. Here, we describe the vertical and lateral spatial dependence of sulfur chemistry in the hydrophobic organic acid fraction of DOM from unimpacted and sulfate-impacted Everglades wetlands using X-ray absorption spectroscopy and ultrahigh-resolution mass spectrometry. Spatial variation in DOM sulfur content and speciation reflects the degree of sulfate enrichment and resulting sulfide concentrations in sediment pore waters. Sulfur is incorporated into DOM predominantly as highly reduced species in sulfidic pore waters. Sulfur-enriched DOM in sediment pore waters exchanges with overlying surface waters and the sulfur likely undergoes oxidative transformations in the water column. Across all wetland sites and depths, the total sulfur content of DOM correlated with the relative abundance of highly reduced sulfur functionality. The results identify sulfate input as a primary determinant on DOM sulfur chemistry to be considered in the context of wetland restoration and sulfur and trace metal cycling.

  8. Effect of CO2 enrichment on bacterial metabolism in an Arctic fjord

    NASA Astrophysics Data System (ADS)

    Motegi, C.; Tanaka, T.; Piontek, J.; Brussaard, C. P. D.; Gattuso, J.-P.; Weinbauer, M. G.

    2013-05-01

    The anthropogenic increase of carbon dioxide (CO2) alters the seawater carbonate chemistry, with a decline of pH and an increase in the partial pressure of CO2 (pCO2). Although bacteria play a major role in carbon cycling, little is known about the impact of rising pCO2 on bacterial carbon metabolism, especially for natural bacterial communities. In this study, we investigated the effect of rising pCO2 on bacterial production (BP), bacterial respiration (BR) and bacterial carbon metabolism during a mesocosm experiment performed in Kongsfjorden (Svalbard) in 2010. Nine mesocosms with pCO2 levels ranging from ca. 180 to 1400 μatm were deployed in the fjord and monitored for 30 days. Generally BP gradually decreased in all mesocosms in an initial phase, showed a large (3.6-fold average) but temporary increase on day 10, and increased slightly after inorganic nutrient addition. Over the wide range of pCO2 investigated, the patterns in BP and growth rate of bulk and free-living communities were generally similar over time. However, BP of the bulk community significantly decreased with increasing pCO2 after nutrient addition (day 14). In addition, increasing pCO2 enhanced the leucine to thymidine (Leu : TdR) ratio at the end of experiment, suggesting that pCO2 may alter the growth balance of bacteria. Stepwise multiple regression analysis suggests that multiple factors, including pCO2, explained the changes of BP, growth rate and Leu : TdR ratio at the end of the experiment. In contrast to BP, no clear trend and effect of changes of pCO2 was observed for BR, bacterial carbon demand and bacterial growth efficiency. Overall, the results suggest that changes in pCO2 potentially influence bacterial production, growth rate and growth balance rather than the conversion of dissolved organic matter into CO2.

  9. Bacterial diversity and reductive dehalogenase redundancy in a 1,2-dichloroethane-degrading bacterial consortium enriched from a contaminated aquifer

    PubMed Central

    2010-01-01

    Background Bacteria possess a reservoir of metabolic functionalities ready to be exploited for multiple purposes. The use of microorganisms to clean up xenobiotics from polluted ecosystems (e.g. soil and water) represents an eco-sustainable and powerful alternative to traditional remediation processes. Recent developments in molecular-biology-based techniques have led to rapid and accurate strategies for monitoring and identification of bacteria and catabolic genes involved in the degradation of xenobiotics, key processes to follow up the activities in situ. Results We report the characterization of the response of an enriched bacterial community of a 1,2-dichloroethane (1,2-DCA) contaminated aquifer to the spiking with 5 mM lactate as electron donor in microcosm studies. After 15 days of incubation, the microbial community structure was analyzed. The bacterial 16S rRNA gene clone library showed that the most represented phylogenetic group within the consortium was affiliated with the phylum Firmicutes. Among them, known degraders of chlorinated compounds were identified. A reductive dehalogenase genes clone library showed that the community held four phylogenetically-distinct catalytic enzymes, all conserving signature residues previously shown to be linked to 1,2-DCA dehalogenation. Conclusions The overall data indicate that the enriched bacterial consortium shares the metabolic functionality between different members of the microbial community and is characterized by a high functional redundancy. These are fundamental features for the maintenance of the community's functionality, especially under stress conditions and suggest the feasibility of a bioremediation treatment with a potential prompt dehalogenation and a process stability over time. PMID:20170484

  10. Nutrient enrichment reduces constraints on material flows in a detritus-based food web.

    PubMed

    Cross, Wyatt F; Wallace, J Bruce; Rosemond, Amy D

    2007-10-01

    predators (from -80% to 55%). Our results demonstrate that nutrient enrichment of detritus-based systems may reduce stoichiometric constraints on material flows, increase the contribution of consumers to C, N, and P cycling, alter the proportion of C inputs metabolized by consumers, and potentially lead to reduced ecosystem-level storage of C.

  11. The RERTR (Reduced Enrichment Research and Test Reactor) Program: Progress and plans

    SciTech Connect

    Travelli, A.

    1987-01-01

    The progress of the Reduced Enrichment Research and Test Reactor (RERTR) Program is described. After a brief summary of the results which the RERTR Program, in collaboration with its many international partners, had achieved by the end of 1986, the activities, results, and new developments which occurred in 1987 are reviewed. Irradiation of the second miniplate series, concentrating on U/sub 3/Si/sub 2/-Al and U/sub 3/Si-Al fuels, was completed and postirradiation examinations were performed on many of its miniplates. The whole-core ORR demonstration with U/sub 3/Si/sub 2/-Al fuel at 4.8 g U/cm/sup 3/ was completed at the end of March with excellent results and with 29 elements estimated to have reached at least 40% average burnup. Good progress was made in the area of LEU usage for the production of fission /sup 99/Mo, and in the coordination of safety evaluations related to LEU conversions of US university reactors. Planned activities include testing and demonstrating advanced fuels intended to allow use of reduced enrichment uranium in very-high-performance reactors. Two candidate fuels are U/sub 3/Si-Al with 19.75% enrichment and U/sub 3/Si/sub 2/-Al with 45% enrichment. Demonstration of these fuels will include irradiation of full-size elements and, possibly, a full-core demonstration. Achievement of the final program goals is still projected for 1990. This progress could not have been possible without the close international cooperation which has existed from the beginning, and which is essential to the ultimate success of the RERTR Program.

  12. Enrichment and Molecular Characterization of a Bacterial Culture That Degrades Methoxy-Methyl Urea Herbicides and Their Aniline Derivatives

    PubMed Central

    El-Fantroussi, Said

    2000-01-01

    Soil treated with linuron for more than 10 years showed high biodegradation activity towards methoxy-methyl urea herbicides. Untreated control soil samples taken from the same location did not express any linuron degradation activity, even after 40 days of incubation. Hence, the occurrence in the field of a microbiota having the capacity to degrade a specific herbicide was related to the long-term treatment of the soil. The enrichment culture isolated from treated soil showed specific degradation activity towards methoxy-methyl urea herbicides, such as linuron and metobromuron, while dimethyl urea herbicides, such as diuron, chlorotoluron, and isoproturon, were not transformed. The putative metabolic intermediates of linuron and metobromuron, the aniline derivatives 3,4-dichloroaniline and 4-bromoaniline, were also degraded. The temperature of incubation drastically affected degradation of the aniline derivatives. Whereas linuron was transformed at 28 and 37°C, 3,4-dichloroaniline was transformed only at 28°C. Monitoring the enrichment process by reverse transcription-PCR and denaturing gradient gel electrophoresis (DGGE) showed that a mixture of bacterial species under adequate physiological conditions was required to completely transform linuron. This research indicates that for biodegradation of linuron, several years of adaptation have led to selection of a bacterial consortium capable of completely transforming linuron. Moreover, several of the putative species appear to be difficult to culture since they were detectable by DGGE but were not culturable on agar plates. PMID:11097876

  13. Bacterial isolates from polysaccharide enrichments cluster by host origin for Firmicutes but not Bacteroidetes.

    USDA-ARS?s Scientific Manuscript database

    The intestinal microbiota allows mammals to recover energy stored in plant biomass through fermentation of plant cell walls, primarily cellulose and hemicellulose. Bacteria were isolated from 8 week continuous culture enrichments with cellulose and xylan/pectin from cow (C, n=4), goat (G, n=4), huma...

  14. Enriched Housing Reduces Disease Susceptibility to Co-Infection with Porcine Reproductive and Respiratory Virus (PRRSV) and Actinobacillus pleuropneumoniae (A. pleuropneumoniae) in Young Pigs

    PubMed Central

    van Dixhoorn, Ingrid D. E.; Reimert, Inonge; Middelkoop, Jenny; Bolhuis, J. Elizabeth; Wisselink, Henk J.; Groot Koerkamp, Peter W. G.; Kemp, Bas; Stockhofe-Zurwieden, Norbert

    2016-01-01

    Until today, anti-microbial drugs have been the therapy of choice to combat bacterial diseases. Resistance against antibiotics is of growing concern in man and animals. Stress, caused by demanding environmental conditions, can reduce immune protection in the host, influencing the onset and outcome of infectious diseases. Therefore psychoneuro-immunological intervention may prove to be a successful approach to diminish the impact of diseases and antibiotics use. This study was designed to investigate the effect of social and environmental enrichment on the impact of disease, referred to as “disease susceptibility”, in pigs using a co-infection model of PRRSV and A. pleuropneumoniae. Twenty-eight pigs were raised in four pens under barren conditions and twenty-eight other pigs were raised in four pens under enriched conditions. In the enriched pens a combination of established social and environmental enrichment factors were introduced. Two pens of the barren (BH) and two pens of the enriched housed (EH) pigs were infected with PRRSV followed by A. pleuropneumoniae, the other two pens in each housing treatment served as control groups. We tested if differences in disease susceptibility in terms of pathological and clinical outcome were related to the different housing regimes and if this was reflected in differences in behavioural and immunological states of the animals. Enriched housed pigs showed a faster clearance of viral PRRSV RNA in blood serum (p = 0.014) and histologically 2.8 fold less interstitial pneumonia signs in the lungs (p = 0.014). More barren housed than enriched housed pigs developed lesions in the lungs (OR = 19.2, p = 0.048) and the lesions in the barren housed pigs showed a higher total pathologic tissue damage score (p<0.001) than those in enriched housed pigs. EH pigs showed less stress-related behaviour and differed immunologically and clinically from BH pigs. We conclude that enriched housing management reduces disease susceptibility to

  15. Enriched Housing Reduces Disease Susceptibility to Co-Infection with Porcine Reproductive and Respiratory Virus (PRRSV) and Actinobacillus pleuropneumoniae (A. pleuropneumoniae) in Young Pigs.

    PubMed

    van Dixhoorn, Ingrid D E; Reimert, Inonge; Middelkoop, Jenny; Bolhuis, J Elizabeth; Wisselink, Henk J; Groot Koerkamp, Peter W G; Kemp, Bas; Stockhofe-Zurwieden, Norbert

    2016-01-01

    Until today, anti-microbial drugs have been the therapy of choice to combat bacterial diseases. Resistance against antibiotics is of growing concern in man and animals. Stress, caused by demanding environmental conditions, can reduce immune protection in the host, influencing the onset and outcome of infectious diseases. Therefore psychoneuro-immunological intervention may prove to be a successful approach to diminish the impact of diseases and antibiotics use. This study was designed to investigate the effect of social and environmental enrichment on the impact of disease, referred to as "disease susceptibility", in pigs using a co-infection model of PRRSV and A. pleuropneumoniae. Twenty-eight pigs were raised in four pens under barren conditions and twenty-eight other pigs were raised in four pens under enriched conditions. In the enriched pens a combination of established social and environmental enrichment factors were introduced. Two pens of the barren (BH) and two pens of the enriched housed (EH) pigs were infected with PRRSV followed by A. pleuropneumoniae, the other two pens in each housing treatment served as control groups. We tested if differences in disease susceptibility in terms of pathological and clinical outcome were related to the different housing regimes and if this was reflected in differences in behavioural and immunological states of the animals. Enriched housed pigs showed a faster clearance of viral PRRSV RNA in blood serum (p = 0.014) and histologically 2.8 fold less interstitial pneumonia signs in the lungs (p = 0.014). More barren housed than enriched housed pigs developed lesions in the lungs (OR = 19.2, p = 0.048) and the lesions in the barren housed pigs showed a higher total pathologic tissue damage score (p<0.001) than those in enriched housed pigs. EH pigs showed less stress-related behaviour and differed immunologically and clinically from BH pigs. We conclude that enriched housing management reduces disease susceptibility to co

  16. Cognitive Enrichment in Piglet Rearing: An Approach to Enhance Animal Welfare and to Reduce Aggressive Behaviour

    PubMed Central

    Rauterberg, Sally; Viazzi, Stefano; Oczak, Maciej; Bahr, Claudia; Guarino, Marcella; Vranken, Erik; Berckmans, Daniel; Hartung, Jörg

    2013-01-01

    It is known that pigs raised in enriched environments express less aggressive behaviour. For this reason, a new method of cognitive environmental enrichment was experimented at the University of Veterinary Medicine Hannover, Germany. In the first phase, 78 suckling piglets were trained to learn the link between a sound given by an electronic feeder and a feed reward in the form of chocolate candies during a period of 8 days. In the second phase, the same piglets were used in resident-intruder tests to verify the potential of the feeding system to interrupt aggressive behaviour. The analysis of all training rounds revealed that piglets learned the commands during 8 days of training and the interest of the piglets increased within training days (P < 0.05). In the resident-intruder test, 79.5% of aggressive interactions were broken by feeder activation. In interactions where either the aggressor or the receiver reacted, a high number of fights were stopped (96.7% versus 93.1%) indicating that it was not relevant if the aggressor or the receiver responded to the feeder activation. We conclude that the electronic feeding system has the potential to be used as cognitive enrichment for piglets, being suitable for reducing aggressive behaviour in resident-intruder situations. PMID:24198969

  17. Isolate PM1 populations are dominant and novel methyl tert-butyl ether-degrading bacterial in compost biofilter enrichments.

    PubMed

    Bruns, M A; Hanson, J R; Mefford, J; Scow, K M

    2001-03-01

    The gasoline additive MTBE, methyl tert-butyl ether, is a widespread and persistent groundwater contaminant. MTBE undergoes rapid mineralization as the sole carbon and energy source of bacterial strain PM1, isolated from an enrichment culture of compost biofilter material. In this report, we describe the results of microbial community DNA profiling to assess the relative dominance of isolate PM1 and other bacterial strains cultured from the compost enrichment. Three polymerase chain reaction (PCR)-based profiling approaches were evaluated: denaturing gradient gel electrophoresis (DGGE) analysis of 230 bp 16S rDNA fragments; thermal gradient gel electrophoresis (TGGE) analysis of 575 bp 16S rDNA fragments; and non-denaturing polyacrylamide gel electrophoresis of 300-1,500 bp fragments containing 16S/23S ribosomal intergenic transcribed spacer (ITS) regions. Whereas all three DNA profiling approaches indicated that PM1-like bands predominated in mixtures from MTBE-grown enrichments, ITS profiling provided the most abundant and specific sequence data to confirm strain PM1's presence in the enrichment. Moreover, ITS profiling did not produce non-specific PCR products that were observed with T/DGGE. A further advantage of ITS community profiling over other methods requiring restriction digestion (e.g. terminal restriction fragment length polymorphisms) was that it did not require an additional digestion step or the use of automated sequencing equipment. ITS bands, excised from similar locations in profiles of the enrichment and PM1 pure culture, were 99.9% identical across 750 16S rDNA positions and 100% identical across 691 spacer positions. BLAST comparisons of nearly full-length 16S rDNA sequences showed 96% similarity between isolate PM1 and representatives of at least four different genera in the Leptothrix subgroup of the beta-Proteobacteria (Aquabacterium, Leptothrix, Rubrivivax and Ideonella). Maximum likelihood and parsimony analyses of 1,249 nucleotide

  18. Anaerobic Degradation of Pristane in Nitrate-Reducing Microcosms and Enrichment Cultures

    PubMed Central

    Bregnard, T. P.; Haner, A.; Hohener, P.; Zeyer, J.

    1997-01-01

    Microcosm studies were conducted under nitrate-reducing conditions with diesel fuel-contaminated aquifer material from a site treated by in situ bioremediation. In the microcosms, the consumption of nitrate and the production of inorganic carbon were strongly stimulated by the addition of the isoprenoid alkane pristane (2,6,10,14-tetramethylpentadecane). Within 102 days enrichment cultures degraded more than 90% of the pristane supplied as coatings on reticulated sinter glass rings. The study demonstrates that pristane can no longer be regarded as recalcitrant under anaerobic conditions. PMID:16535616

  19. Reduced order variational multiscale enrichment method for thermo-mechanical problems

    NASA Astrophysics Data System (ADS)

    Zhang, Shuhai; Oskay, Caglar

    2017-06-01

    This manuscript presents the formulation and implementation of the reduced order variational multiscale enrichment (ROVME) method for thermo-mechanical problems. ROVME is extended to model the inelastic behavior of heterogeneous structures, in which the constituent properties are temperature sensitive. The temperature-dependent coefficient tensors of the reduced order method are approximated in an efficient manner, retaining the computational efficiency of the reduced order model in the presence of spatial/temporal temperature variations. A Newton-Raphson iterative scheme is formulated and implemented for the numerical evaluation of nonlinear system of equations associated with the proposed ROVME method. Numerical verifications are performed to assess the efficiency and accuracy of the proposed computational framework. The results of the verifications reveal that ROVME retains reasonable accuracy and achieves high efficiency in the presence of hermo-mechanical loads.

  20. Reduced order variational multiscale enrichment method for thermo-mechanical problems

    NASA Astrophysics Data System (ADS)

    Zhang, Shuhai; Oskay, Caglar

    2017-02-01

    This manuscript presents the formulation and implementation of the reduced order variational multiscale enrichment (ROVME) method for thermo-mechanical problems. ROVME is extended to model the inelastic behavior of heterogeneous structures, in which the constituent properties are temperature sensitive. The temperature-dependent coefficient tensors of the reduced order method are approximated in an efficient manner, retaining the computational efficiency of the reduced order model in the presence of spatial/temporal temperature variations. A Newton-Raphson iterative scheme is formulated and implemented for the numerical evaluation of nonlinear system of equations associated with the proposed ROVME method. Numerical verifications are performed to assess the efficiency and accuracy of the proposed computational framework. The results of the verifications reveal that ROVME retains reasonable accuracy and achieves high efficiency in the presence of hermo-mechanical loads.

  1. Characterization of an isoproturon mineralizing bacterial culture enriched from a French agricultural soil.

    PubMed

    Hussain, Sabir; Sørensen, Sebastian R; Devers-Lamrani, Marion; El-Sebai, Talaat; Martin-Laurent, Fabrice

    2009-11-01

    The phenylurea herbicide isoproturon, 3-(4-isopropylphenyl)-1,1-dimethylurea (IPU), was found to be rapidly mineralized by a bacterial culture isolated from an agricultural soil regularly exposed to IPU. Molecular analysis of the bacterial culture by DNA fingerprinting, cloning and sequencing of the 16S rRNA genes revealed that it consisted of six different members among whom the dominant was related to Sphingomonas sp. Six bacterial strains belonging to genera Ancylobacter, Pseudomonas, Stenotrophomonas, Methylobacterium, Variovorax and Agrobacterium were isolated from the IPU-degrading culture. None of these were able to degrade IPU in pure culture and only the intact culture sustained the ability to mineralize IPU. The composition of the culture appeared stable suggesting that yet unknown interactions are involved in the IPU mineralization. IPU degradation involved the transitory accumulation of three known IPU metabolites 3-(4-isopropylphenyl)-1-methylurea, 3-(4-isopropylphenyl)-urea, and 4-isopropylaniline and their further degradation. Thus, it indicates a metabolic pathway initiated by two successive N-demethylations, followed by cleavage of the urea side chain. This culture did not degrade other structurally related phenylurea herbicides. The degrading activity of the bacterial culture was deeply influenced by the pH, being completely inhibited at pH 5.5 and optimal at pH 7.5.

  2. Goat milk fat naturally enriched with conjugated linoleic acid increased lipoproteins and reduced triacylglycerol in rats.

    PubMed

    Rodrigues, Raphaela; Soares, Juliana; Garcia, Hugo; Nascimento, Claudenice; Medeiros, Maria; Bomfim, Marco; Medeiros, Maria Carmo; Queiroga, Rita

    2014-03-24

    Goat milk is source of different lipids, including conjugated linoleic acid (CLA). CLA reduces body fat and protect against cardiovascular diseases. In the present study fat from goat milk naturally enriched with CLA was used. Male Wistar rats were divided into three groups that received during a 10 week diet with different lipid sources: soybean oil (CON), coconut oil (CO) and goat milk fat naturally enriched with CLA (GM-CLA). We evaluated the effects of a GM-CLA on biochemistry parameters--high density lipoprotein (HDL), triacylglycerol (TAG), TAG/HDL ratio, total cholesterol and glucose, body weight and histopathological aspects of the intestine and liver. GM-CLA increased body weight from the second to the fifth week of the experiment compared to CON. Feed intake differed between the CON group and GM-CLA early in the first to third week of the experiments and later between the ninth and tenth week. The CLA-diet group showed increased levels of HDL, reduced levels of TAG and TAG/HDL ratio and no effect on LDL, but enhanced total cholesterol. Serum glucose of the GM-CLA group showed no difference from the control group. Thus, a GM-CLA diet promoted growth in young rats and acted as protector of cardiovascular function, but further studies are still needed to clarify these effects.

  3. Changes in sediment bacterial community in response to long-term nutrient enrichment in a subtropical seagrass-dominated estuary.

    PubMed

    Guevara, Rafael; Ikenaga, Makoto; Dean, Amanda L; Pisani, Cristina; Boyer, Joseph N

    2014-10-01

    Florida Bay exhibits a natural gradient of strong P limitation in the east which shifts to weak P or even N limitation at the western boundary. This nutrient gradient greatly affects seagrass abundance and productivity across the bay. We assessed the effects of N and P additions on sediment bacterial community structure in relation to the existing nutrient gradient in Florida Bay. Sediment samples from 24 permanent 0.25 m(2) plots in each of six sites across Florida Bay were fertilized with granular N and P in a factorial design for 26 months. Sediment bacterial community structure was analyzed using PCR-denaturing gradient gel electrophoresis (DGGE) analysis of 16S ribosomal RNA (rRNA) genes and a cloning strategy from DGGE bands. The phylogenetic positions of 16S rRNA sequences mostly fell into common members found in marine sediments such as sulfate-reducing Deltaproteobacteria, Gammaproteobacteria, Spirochaetes, and Bacteriodetes. Twenty-eight common DGGE bands were found in all sediment samples; however, some DGGE bands were only found or were better represented in eastern sites. Bacterial community diversity (Shannon-Weiner index) showed similar values throughout all sediment samples. The N treatment had no effect on the bacterial community structures across the bay. Conversely, the addition of P significantly influenced the bacterial community structure at all but the most western site, where P is least limiting due to inputs from the Gulf of Mexico. P additions enhanced DGGE band sequences related to Cytophagales, Ectothiorhodospiraceae, and Desulfobulbaceae, suggesting a shift toward bacterial communities with increased capability to degrade polymeric organic matter. In addition, a band related to Deferribacteres was enhanced in eastern sites. Thus, indigenous environmental conditions were the primary determining factors controlling the bacterial communities, while the addition of P was a secondary determining factor. This P-induced change in community

  4. Does glutamine reduce bacterial translocation? A study in two animal models with impaired gut barrier.

    PubMed

    Foitzik, T; Kruschewski, M; Kroesen, A J; Hotz, H G; Eibl, G; Buhr, H J

    1999-08-01

    Failure of intestinal barrier function and subsequent translocation of bacteria from the gut are believed to play a decisive role in the development of systemic septic complications, for example, following major trauma or major abdominal surgery. This study evaluated: (a) the effect of glutamine on colonic microcirculation and electrophysiological parameters reflecting gut barrier function, (b) the translocation of live bacteria to extraintestinal organs, and (c) disease outcome in two animal models with impaired gut barrier function. Severe acute pancreatitis or colitis was induced in rats randomized for therapy with or without glutamine (0.5 g/kg daily). After 48 h one animal group was prepared for intravital microscopy of colonic capillary blood flow and electrophysiological measurement of gut permeability; another was killed after 96 h for histological and microbiological examination. In animals with pancreatitis, glutamine (Gln) supplementation significantly improved gut permeability, i.e., Gln increased colonic transmucosal resistance from 67+/-7 to 92+/-3 Omega/cm(2) and decreased mannitol flux through the epithelium by 53%. Capillary blood flow in the colonic mucosa was improved by 25%. The prevalence of pancreatic infections was reduced from 86% in animals on standard parenteral nutrition to 33% in animals given the Gln-enriched diet (P<0.05); mortality decreased by 32%. In colitis, Gln had no significant effect on these parameters except for improving colonic capillary blood flow in colon segments not adjacent to the major injury site. Glutamine supplementation improves colonic capillary blood flow, stabilizes gut permeability, and reduces secondary pancreatic infections and mortality in severe rodent pancreatitis, but it is not helpful in colitis. This confirms previous reports that glutamine stabilizes gut barrier function only in certain diseases. Our experimental data strongly suggest that acute pancreatitis (rather than colitis) is one of the

  5. Anaerobic biotransformation of high concentrations of chloroform by an enrichment culture and two bacterial isolates.

    PubMed

    Shan, Huifeng; Kurtz, Harry D; Mykytczuk, Nadia; Trevors, Jack T; Freedman, David L

    2010-10-01

    A fermentative enrichment culture (designated DHM-1) was developed that is capable of cometabolically biotransforming high concentrations of chloroform (CF) to nontoxic end products. Two Pantoea spp. were isolated from DHM-1 that also possess this dechlorination capability. Following acclimation to increasing levels of CF, corn syrup-grown DHM-1 was able to transform over 500 mg/liter CF in the presence of vitamin B(12) (approximately 3% of CF on a molar basis) at a rate as high as 22 mg/liter/day in a mineral salts medium. CO, CO(2), and organic acids were the predominant biodegradation products, suggesting that hydrolytic reactions predominate during CF transformation. DHM-1 was capable of growing on corn syrup in the presence of high concentrations of CF (as may be present near contaminant source zones in groundwater), which makes it a promising culture for bioaugmentation. Strains DHM-1B and DHM-1T transform CF at rates similar to that of the DHM-1 enrichment culture. The ability of these strains to grow in the presence of high concentrations of CF appears to be related to alteration of membrane fluidity or homeoviscous and homeophasic adaptation.

  6. Mo enrichment in black shale and reduction of molybdate by sulfate-reducing bacteria (SRB) (Invited)

    NASA Astrophysics Data System (ADS)

    Xu, H.; Barton, L. L.

    2010-12-01

    The Lower Cambrian Black shale in Zunyi area of Guizhou Province, Southern China contains significant amount of Mo, As, and sulfide minerals. Additionally, Mo and sulfides are closely associated with organic matter of kerogen. Transmission electron microscopy (TEM) results show pyrite micro-crystals and Mo-As-S-bearing carbon (kerogen). High-resolution TEM image shows that Mo-rich areas are Mo-sulfide (molybdenite) layers that form poorly crystalline structures in organic carbon matrix. X-ray energy-dispersive spectra (EDS) indicate composition from the pyrite and the Mo-rich area. The black shale is very unique because of its high Mo concentration. One possible mechanism for enriching Mo from paleo-seawater is the involvement of SRB. Molybdate is an essential trace element required by biological systems including the anaerobic sulfate-reducing bacteria (SRB); however, detrimental consequences may occur if molybdate is present in high concentrations in the environment. We followed the growth of Desulfovibrio gigas ATCC 19364, D. vulgaris Hildenborough, D. desulfuricans DSM 642, and D. desulfuricans DSM 27774 in media containing sub-lethal levels of molybdate and observed a red-brown color in the culture fluid. Spectral analysis of the culture fluid revealed absorption peaks at 467 nm, 395 nm and 314 nm and this color is proposed to be a molybdate-sulfide complex. Reduction of molybdate with the formation of molybdate disulfide occurs in the periplasm D. gigas and D. desulfuricans DSM 642. From these results we suggest that the occurrence of poorly crystalline Mo-sulfides in black shale may be a result from SRB reduction and selective enrichment of Mo in paleo-seawater. We suggest that similar SRB mechanism could cause the Mo enrichment in a ~ 2.5 billion years old late Archean McRae Shale, which is related to the great oxidation event of early earth atmosphere.

  7. Novel Method for Identifying Bacterial Mutants with Reduced Epiphytic Fitness

    PubMed Central

    Lindow, Steven E.

    1993-01-01

    In order to identify novel traits involved in epiphytic colonization, a technique for the rapid identification of bacterial mutants with quantitatively different population sizes in a natural habitat based on measurements of ice nucleation activity was developed. The threshold freezing temperatures of leaves harboring different numbers of cells of ice nucleation-active Pseudomonas syringae B728a differed substantially. While few leaves containing less than about 106 cells per g (fresh weight) froze at assay temperatures of -2.75°C or higher, nearly all leaves froze at these temperatures when population sizes of this strain increased to about 107 cells per g (fresh weight). Presumptive epiphytic fitness mutants could readily be identified as strains which initiated freezing in fewer leaves than did other strains within a given experiment. Most Tn5-induced mutants of strain B728a which conferred a low frequency of ice nucleation on inoculated bean leaves generally had a smaller population size than the parental strain at the time of the leaf freezing assay. The leaf freezing assay was capable of differentiating samples which varied by approximately three- to fivefold in mean bacterial population size. PMID:16348938

  8. Novel method for identifying bacterial mutants with reduced epiphytic fitness.

    PubMed

    Lindow, S E

    1993-05-01

    In order to identify novel traits involved in epiphytic colonization, a technique for the rapid identification of bacterial mutants with quantitatively different population sizes in a natural habitat based on measurements of ice nucleation activity was developed. The threshold freezing temperatures of leaves harboring different numbers of cells of ice nucleation-active Pseudomonas syringae B728a differed substantially. While few leaves containing less than about 10 cells per g (fresh weight) froze at assay temperatures of -2.75 degrees C or higher, nearly all leaves froze at these temperatures when population sizes of this strain increased to about 10 cells per g (fresh weight). Presumptive epiphytic fitness mutants could readily be identified as strains which initiated freezing in fewer leaves than did other strains within a given experiment. Most Tn5-induced mutants of strain B728a which conferred a low frequency of ice nucleation on inoculated bean leaves generally had a smaller population size than the parental strain at the time of the leaf freezing assay. The leaf freezing assay was capable of differentiating samples which varied by approximately three- to fivefold in mean bacterial population size.

  9. Composition, Reactivity, and Regulations of Extracellular Metal-Reducing Structures (Bacterial Nanowires) Produced by Dissimilatory Metal Reducing Bacteria

    SciTech Connect

    Scholten, Johannes

    2006-06-01

    This research proposal seeks to describe the composition and function of electrically conductive appendages known as bacterial nanowires. This project targets bacterial nanowires produced by dissimilatory metal reducing bacteria Shewanella and Geobacter. Specifically, this project will investigate the role of these structures in the reductive transformation of iron oxides as solid phase electron acceptors, as well as uranium as a dissolved electron acceptor that forms nanocrystalline particles of uraninite upon reduction.

  10. Partial Safety Analysis for a Reduced Uranium Enrichment Core for the High Flux Isotope Reactor

    SciTech Connect

    Primm, Trent; Gehin, Jess C

    2009-04-01

    A computational model of the reactor core of the High Flux Isotope Rector (HFIR) was developed in order to analyze non-destructive accidents caused by transients during reactor operation. The reactor model was built for the latest version of the nuclear analysis software package called Program for the Analysis of Reactor Transients (PARET). Analyses performed with the model constructed were compared with previous data obtained with other tools in order to benchmark the code. Finally, the model was used to analyze the behavior of the reactor under transients using a different nuclear fuel with lower enrichment of uranium (LEU) than the fuel currently used, which has a high enrichment of uranium (HEU). The study shows that the presence of fertile isotopes in LEU fuel, which increases the neutron resonance absorption, reduces the impact of transients on the fuel and enhances the negative reactivity feedback, thus, within the limitations of this study, making LEU fuel appear to be a safe alternative fuel for the reactor core.

  11. High-density reduced-enrichment fuels for Research and Test Reactors

    SciTech Connect

    Snelgrove, J.L.; Hofman, G.L.; Copeland, G.L.

    1983-01-01

    Development and irradiation testing of high-density fuels have been conducted by the US RERTR Program in order to provide the technical means to reduce the enrichment of fuels for research and test reactors. The traditional aluminum dispersion fuel technology has been extended to include the highest practical loadings of uranium-aluminide (UAl/sub x/, 2.3 MgU/m/sup 3/), uranium-oxide (U/sub 3/O/sub 8/, 3.2 MgU/m/sup 3/), and uranium-silicide (U/sub 3/Si/sub 2/, 5.5 MgU/m/sup 3/; U/sub 3/Si, 7.0 MgU/m/sup 3/) fuels. A third uranium-silicide alloy, U/sub 3/SiAl (U + 3.5 wt % Si + 1.5 wt % Al) has been found to perform poorly at high burnup. Testing of miniature fuel plates and full-sized fuel elements is at an advanced stage for the highest loadings of the aluminide and oxide fuels and intermediate loadings of the silicide fuels, and good results have been obtained for low-enriched uranium. The data obtained to date are discussed. 1 reference, 3 figures, 1 table.

  12. Enrichment and isolation of acidophilic sulfate-reducing bacteria from Tinto River sediments.

    PubMed

    Sánchez-Andrea, Irene; Stams, Alfons J M; Amils, Ricardo; Sanz, José Luis

    2013-10-01

    Although some acidophilic and alkaliphilic species have been described recently, most of the known sulfate-reducing bacteria (SRB) grow optimally at neutral pH. In this study, sulfate reduction was studied with sediment samples from the extremely acidic Tinto River basin. Stable enrichments of SRB were obtained at pH 4 with glycerol, methanol and hydrogen; at pH 4.5 with lactate and at pH 5.5 with succinate as substrates. Inhibition of sulfate reduction by organic acids below their pKa was observed. Cloning and sequencing of 16S rRNA gene showed that fermentative bacteria (Paludibacter spp., Oscillibacter spp.) and SRB (Thermodesulfobium spp., Desulfosporosinus spp., Desulfitobacterium spp., Desulfotomaculum spp.) were co-enriched. By repeated serial dilutions and streaking on agar plates, four strains of SRB belonging to the Firmicutes phylum were obtained. Two of them show 96% 16S rRNA gene sequence similarity with Desulfosporosinus acidophilus, and a third one with Desulfosporosinus orientis. Another isolate has just 93% rRNA gene sequence similarity with the Desulfosporosinus/Desulfitobacterium cluster and might represent a novel species within a novel genus. One of the Desulfosporosinus strains was further investigated showing maximum growth at pH 5.5, and a pH-dependent inhibitory effect of organic acids and sulfide. © 2013 John Wiley & Sons Ltd and Society for Applied Microbiology.

  13. Hyperoxaluria leads to dysbiosis and drives selective enrichment of oxalate metabolizing bacterial species in recurrent kidney stone endures

    PubMed Central

    Suryavanshi, Mangesh V.; Bhute, Shrikant S.; Jadhav, Swapnil D.; Bhatia, Manish S.; Gune, Rahul P.; Shouche, Yogesh S.

    2016-01-01

    Hyperoxaluria due to endogenously synthesized and exogenously ingested oxalates is a leading cause of recurrent oxalate stone formations. Even though, humans largely rely on gut microbiota for oxalate homeostasis, hyperoxaluria associated gut microbiota features remain largely unknown. Based on 16S rRNA gene amplicons, targeted metagenomic sequencing of formyl-CoA transferase (frc) gene and qPCR assay, we demonstrate a selective enrichment of Oxalate Metabolizing Bacterial Species (OMBS) in hyperoxaluria condition. Interestingly, higher than usual concentration of oxalate was found inhibitory to many gut microbes, including Oxalobacter formigenes, a well-characterized OMBS. In addition a concomitant enrichment of acid tolerant pathobionts in recurrent stone sufferers is observed. Further, specific enzymes participating in oxalate metabolism are found augmented in stone endures. Additionally, hyperoxaluria driven dysbiosis was found to be associated with oxalate content, stone episodes and colonization pattern of Oxalobacter formigenes. Thus, we rationalize the first in-depth surveillance of OMBS in the human gut and their association with hyperoxaluria. Our findings can be utilized in the treatment of hyperoxaluria associated recurrent stone episodes. PMID:27708409

  14. Do edible oils reduce bacterial colonization of enamel in situ?

    PubMed

    Hannig, Christian; Kirsch, Jasmin; Al-Ahmad, Ali; Kensche, Anna; Hannig, Matthias; Kümmerer, Klaus

    2013-03-01

    Edible oils are an empiric approach for the prevention of oral diseases. The present in situ study investigated the effect of edible oils on initial bacterial colonization of enamel surfaces. Initial biofilm formation was performed on enamel specimens mounted on maxillary splints and carried by eight subjects. After 1 min of pellicle formation, rinses with safflower oil, olive oil and linseed oil were performed for 10 min. Application of chlorhexidine for 1 min served as positive control. Afterwards, the slabs were carried for 8 h overnight. Samples carried for 8 h without any rinse served as negative controls. The amount of adherent bacteria was determined by DAPI staining (4',6-diamidino-2-phenylindole) and live-dead staining (BacLight). Additionally, determination of colony forming units was performed after desorption of the bacteria. TEM evaluation was carried out after application of the rinses. The number of adherent bacteria on control samples was 6.1 ± 8.1 × 10(5)/cm(2) after 8 h (DAPI). Fluorescence microscopic data from DAPI staining and live-dead staining as well as from the determination of CFU revealed no significant effects of rinsing with oils on the amount of adherent bacteria compared to the non-rinsed control samples. However, with chlorhexidine a significant reduction in the number of bacteria by more than 85 % was achieved (DAPI, chlorhexidine: 8.2 ± 17.1 × 10(4)/cm(2)). The ratio of viable to dead bacteria was almost equal (1:1) irrespective of the rinse adopted as recorded with BacLight. TEM indicated accumulation of oil micelles at the pellicle's surface and modification of its ultrastructure. Rinses with edible oils have no significant impact on the initial pattern and amount of bacterial colonization on enamel over 8 h. Rinses with edible oils cannot be recommended for efficient reduction of oral biofilm formation.

  15. Impact of oxygen limitation on glycerol-based biopolymer production by bacterial enrichments.

    PubMed

    Moralejo-Gárate, Helena; Kleerebezem, Robbert; Mosquera-Corral, Anuska; van Loosdrecht, Mark C M

    2013-03-01

    The increasing production of bioethanol and biodiesel has resulted in the generation of a massive amount of crude glycerol, inducing the need for effective valorization of these waste streams. One of the valorization options could be through conversion of crude glycerol into a biopolymer using microbial community engineering in a feast-famine process. A complicating factor in the production of biopolymers from glycerol encountered in previous works is that two different types of polymers can be formed; polyhydroxyalkanoate (PHA) and polyglucose. Here we describe the effect of limiting the oxygen supply rate on the polymer distribution with the aim of defining the conditions that favour the conversion of glycerol in one single polymer. The decrease of oxygen supply rate during the biopolymer maximization step did not influence glycerol partitioning among PHA and polyglucose, but oxygen limitation during the community enrichment step favoured polyglucose storage over PHA. Copyright © 2012 Elsevier Ltd. All rights reserved.

  16. Evolution of a degradative bacterial consortium during the enrichment of naphtha solvent.

    PubMed

    Cavalca, L; Confalonieri, A; Larcher, S; Andreoni, V

    2000-06-01

    A microbial mixed culture able to degrade naphtha solvent, a model of hydrocarbon aromatic mixture, was isolated from a hydrocarbon-polluted soil. Composition of the population was monitored by phenotypic and molecular methods applied on soil DNA, on whole enrichment culture DNA, and on 85 isolated strains. Strains were characterized for their 16S rDNA restriction profiles and for their random amplified polymorphic DNA profiles. Catabolic capabilities were monitored by phenotypic traits and by PCR assays for the presence of the catabolic genes methyl mono-oxygenase ( xylA, M), catechol 2,3 dioxygenase (xylE) and toluene dioxygenase (todC1) of TOL and TOD pathways. Different haplotypes belonging to Pseudomonas putida, Ps. aureofaciens and Ps. aeruginosa were found to degrade aromatic compounds and naphtha solvent. The intrinsic catabolic activity of the microbial population of the polluted site was detected by PCR amplification of the xylE gene directly from soil DNA.

  17. Enriched environment reduces glioma growth through immune and non-immune mechanisms in mice

    PubMed Central

    Garofalo, Stefano; D’Alessandro, Giuseppina; Chece, Giuseppina; Brau, Frederic; Maggi, Laura; Rosa, Alessandro; Porzia, Alessandra; Mainiero, Fabrizio; Esposito, Vincenzo; Lauro, Clotilde; Benigni, Giorgia; Bernardini, Giovanni; Santoni, Angela; Limatola, Cristina

    2015-01-01

    Mice exposed to standard (SE) or enriched environment (EE) were transplanted with murine or human glioma cells and differences in tumour development were evaluated. We report that EE exposure affects: (i) tumour size, increasing mice survival; (ii) glioma establishment, proliferation and invasion; (iii) microglia/macrophage (M/Mφ) activation; (iv) natural killer (NK) cell infiltration and activation; and (v) cerebral levels of IL-15 and BDNF. Direct infusion of IL-15 or BDNF in the brain of mice transplanted with glioma significantly reduces tumour growth. We demonstrate that brain infusion of IL-15 increases the frequency of NK cell infiltrating the tumour and that NK cell depletion reduces the efficacy of EE and IL-15 on tumour size and of EE on mice survival. BDNF infusion reduces M/Mφ infiltration and CD68 immunoreactivity in tumour mass and reduces glioma migration inhibiting the small G protein RhoA through the truncated TrkB.T1 receptor. These results suggest alternative approaches for glioma treatment. PMID:25818172

  18. Enriched environment reduces glioma growth through immune and non-immune mechanisms in mice.

    PubMed

    Garofalo, Stefano; D'Alessandro, Giuseppina; Chece, Giuseppina; Brau, Frederic; Maggi, Laura; Rosa, Alessandro; Porzia, Alessandra; Mainiero, Fabrizio; Esposito, Vincenzo; Lauro, Clotilde; Benigni, Giorgia; Bernardini, Giovanni; Santoni, Angela; Limatola, Cristina

    2015-03-30

    Mice exposed to standard (SE) or enriched environment (EE) were transplanted with murine or human glioma cells and differences in tumour development were evaluated. We report that EE exposure affects: (i) tumour size, increasing mice survival; (ii) glioma establishment, proliferation and invasion; (iii) microglia/macrophage (M/Mφ) activation; (iv) natural killer (NK) cell infiltration and activation; and (v) cerebral levels of IL-15 and BDNF. Direct infusion of IL-15 or BDNF in the brain of mice transplanted with glioma significantly reduces tumour growth. We demonstrate that brain infusion of IL-15 increases the frequency of NK cell infiltrating the tumour and that NK cell depletion reduces the efficacy of EE and IL-15 on tumour size and of EE on mice survival. BDNF infusion reduces M/Mφ infiltration and CD68 immunoreactivity in tumour mass and reduces glioma migration inhibiting the small G protein RhoA through the truncated TrkB.T1 receptor. These results suggest alternative approaches for glioma treatment.

  19. A lack of consensus in the literature findings on the removal of airborne benzene by houseplants: Effect of bacterial enrichment

    NASA Astrophysics Data System (ADS)

    Sriprapat, Wararat; Strand, Stuart E.

    2016-04-01

    Removal rates of benzene and formaldehyde gas by houseplants reported by several laboratories varied by several orders of magnitude. We hypothesized that these variations were caused by differential responses of soil microbial populations to the high levels of pollutant used in the studies, and tested responses to benzene by plants and soils separately. Five houseplant species and tobacco were exposed to benzene under hydroponic conditions and the uptake rates compared. Among the test plants, Syngonium podophyllum and Chlorophytum comosum and Epipremnum aureum had the highest benzene removal rates. The effects of benzene addition on populations of soil bacteria were determined using reverse transcription quantitative PCR (RT-qPCR) assays targeting microbial genes involved in benzene degradation. The total bacterial population increased as shown by increases in the levels of eubacteria 16S rRNA, which was significantly higher in the high benzene incubations than in the low benzene incubations. Transcripts (mRNA) of genes encoding phenol monooxygenases, catechol-2,3-dioxygenase and the housekeeping gene rpoB increased in all soils incubated with high benzene concentrations. Therefore the enrichment of soils with benzene gas levels typical of experiments with houseplants in the literature artificially increased the levels of total soil bacterial populations, and especially the levels and activities of benzene-degrading bacteria.

  20. Bacterial Leakage of Mineral Trioxide Aggregate, Calcium-Enriched Mixture and Biodentine as Furcation Perforation Repair Materials in Primary Molars

    PubMed Central

    Ramazani, Nahid; Sadeghi, Parisa

    2016-01-01

    Introduction: Adequate seal of iatrogenically perforated area within the root canal system can improve the long term treatment prognosis. This in vitro study evaluated the sealing ability of mineral trioxide aggregate (MTA), calcium-enriched mixture (CEM) cement and Biodentine in repair of furcation perforation in primary molars. Methods and Materials: A total of 61 freshly extracted primary mandibular second molars were randomly divided into three groups (n=17) and 10 teeth were put in negative (without perforation, n=5) and positive (perforated without repair, n=5) control groups. Turbidity was used as the criteria of bacterial leakage, when detected in the model of dual-chamber leakage. Data were analyzed using the Chi-Square and Kaplan-Meier survival analysis in SPSS software. The level of significance was set at 0.05. Results: All positive samples showed turbidity, whereas none of the negative samples allowed bacterial leakage. There was no significant difference between the number of turbidity samples in repaired teeth with all test materials (P=0.13). No significant difference was also detected in the mean survival time (P>0.05). Conclusion: CEM cement and Biodentine showed promising results as perforation repair materials and can be recommended as suitable alternatives of MTA for repair of furcation perforation of primary molars. PMID:27471534

  1. Environmental enrichment restores CA1 hippocampal LTP and reduces severity of seizures in epileptic mice.

    PubMed

    Morelli, Emanuela; Ghiglieri, Veronica; Pendolino, Valentina; Bagetta, Vincenza; Pignataro, Annabella; Fejtova, Anna; Costa, Cinzia; Ammassari-Teule, Martine; Gundelfinger, Eckart D; Picconi, Barbara; Calabresi, Paolo

    2014-11-01

    We have analyzed the effects of environmental enrichment (EE) in a seizure-prone mouse model in which the genetic disruption of the presynaptic protein Bassoon leads to structural and functional alterations in the hippocampus and causes early spontaneous seizures mimicking human neurodevelopmental disorders. One-month EE starting at P21 reduced seizure severity, preserved long-term potentiation (LTP) and paired-pulse synaptic responses in the hippocampal CA1 neuronal population and prevented the reduction of spine density and dendrite branching of pyramidal neurons. These data demonstrate that EE exerts its therapeutic effect by normalizing multiple aspects of hippocampal function and provide experimental support for its use in the optimization of existent treatments. Copyright © 2014 Elsevier Inc. All rights reserved.

  2. Satisfaction of farm animal behavioral needs in behaviorally restricted systems: reducing stressors and environmental enrichment.

    PubMed

    Ninomiya, Shigeru

    2014-06-01

    In modern intensive husbandry, systems often restrict farm animal behavior. Behavioral needs will be generated by external stimuli such as stressors deriving from environmental factors or the method of animal care, or some internal factor in farm animals. This means that behavioral restriction would induce maladaptation to stressors or chronic stress. Such a risk of behavioral restriction degrades an animal's physical and mental health and leads to economic loss at a farm. Methods to reduce the risk of behavioral restrictions are to ameliorate the source of a stressor through adequate animal management or to carry out environmental enrichment. This review is intended to describe the relation between animal management and behavioral needs from the perspective of animal motivation. © 2014 Japanese Society of Animal Science.

  3. MULTIPLE IMAGING TECHNIQUES DEMONSTRATE THE MANIPULATION OF SURFACES TO REDUCE BACTERIAL CONTAMINATION

    EPA Science Inventory

    Surface imaging techniques were combined to determine appropriate manipulation of technologically important surfaces for commercial applications. Stainless steel surfaces were engineered to reduce bacterial contamination, biofilm formation, and corrosion during product processing...

  4. MULTIPLE IMAGING TECHNIQUES DEMONSTRATE THE MANIPULATION OF SURFACES TO REDUCE BACTERIAL CONTAMINATION

    EPA Science Inventory

    Surface imaging techniques were combined to determine appropriate manipulation of technologically important surfaces for commercial applications. Stainless steel surfaces were engineered to reduce bacterial contamination, biofilm formation, and corrosion during product processing...

  5. Apical Sealing Ability of Mineral Trioxide Aggregate, Intermediate Restorative Material and Calcium Enriched Mixture Cement: A Bacterial Leakage Study

    PubMed Central

    Shahriari, Shahriar; Faramarzi, Farhad; Alikhani, Mohammad-Yousef; Farhadian, Maryam; Hendi, Seyedeh Sareh

    2016-01-01

    Introduction: This in vitro study compared the apical sealing ability of three common root end filling materials namely mineral trioxide aggregate (MTA), intermediate restorative material (IRM) and calcium-enriched mixture (CEM) cement using a bacterial leakage model. Methods and Materials: The study was conducted on 83 single-rooted human teeth. Tooth crowns were cut and root canals were prepared using the step-back technique. Apical 3 mm of the roots were cut and a three-mm-deep cavity was prepared using an ultrasonic instrument. The samples were divided into three groups (n=25) according to the root-end filling material including MTA, IRM and CEM cement. The roots were inserted into cut-end microtubes. After sterilization with ethylene oxide, microtubes were placed in sterile vials containing 10 mL of Brain Heart Infusion (BHI) broth and incubated at 37°C and 0.1 mL of Enterococcus faecalis suspension compatible with 0.5 McFarland standard (1.5×108 cell/ ml), which was refreshed daily. This procedure was continued for 70 days. The data were analyzed using the chi-square, Kruskal-Wallis and log rank tests. The level of significance was set at 0.05. Results: No significant difference was found in bacterial microleakage among three groups; MTA showed slightly (but not significantly) less microleakage than IRM and CEM. However, the difference in the mean time of microleakage was significant among the groups (P<0.04) and in MTA samples leakage occurred in a longer time than CEM (P<0.012). Conclusion: The three tested root end filling materials had equal sealing efficacy for preventing bacterial leakage. PMID:27790267

  6. Bacterial antibiotic resistance studies using in vitro dynamic models: Population analysis vs. susceptibility testing as endpoints of mutant enrichment.

    PubMed

    Firsov, Alexander A; Strukova, Elena N; Portnoy, Yury A; Shlykova, Darya S; Zinner, Stephen H

    2015-09-01

    Emergence of bacterial antibiotic resistance is usually characterised either by population analysis or susceptibility testing. To compare these endpoints in their ability to demonstrate clear relationships with the ratio of 24-h area under the concentration-time curve (AUC24) to the minimum inhibitory concentration (MIC), enrichment of ciprofloxacin-resistant mutants of four clinical isolates of Pseudomonas aeruginosa was studied in an in vitro dynamic model that simulates mono-exponential pharmacokinetics of ciprofloxacin over a wide range of the AUC24/MIC ratios. Each organism was exposed to twice-daily ciprofloxacin for 3 days. Amplification of resistant mutants was monitored by plating on media with 2×, 4×, 8× and 16× MIC of ciprofloxacin. Population analysis data were expressed by the area under the bacterial mutant concentration-time curve (AUBCM). Changes in P. aeruginosa susceptibility were examined by daily MIC determinations. To account for the different susceptibilities of P. aeruginosa strains, post-exposure MICs (MICfinal) were related to the MICs determined with the starting inoculum (MICinitial). For each organism, AUC24/MIC relationships both with AUBCM and MICfinal/MICinitial were bell-shaped, but the latter were more strain-specific than the former. Using combined data on all four isolates, AUBCM showed a better correlation than MICfinal/MICinitial (r(2)=0.75 vs. r(2)=0.53). The shift of MICfinal/MICinitial relative to AUBCM vs. AUC24/MIC curves resulted in a weak correlation between AUBCM and MICfinal/MICinitial (r(2)=0.41). These data suggest that population analysis is preferable to susceptibility testing in bacterial resistance studies and that these endpoints should not be considered interchangeable.

  7. Assessing the effects of iron enrichment across holobiont compartments reveals reduced microbial nitrogen fixation in the Red Sea coral Pocillopora verrucosa.

    PubMed

    Rädecker, Nils; Pogoreutz, Claudia; Ziegler, Maren; Ashok, Ananya; Barreto, Marcelle M; Chaidez, Veronica; Grupstra, Carsten G B; Ng, Yi Mei; Perna, Gabriela; Aranda, Manuel; Voolstra, Christian R

    2017-08-01

    The productivity of coral reefs in oligotrophic tropical waters is sustained by an efficient uptake and recycling of nutrients. In reef-building corals, the engineers of these ecosystems, this nutrient recycling is facilitated by a constant exchange of nutrients between the animal host and endosymbiotic photosynthetic dinoflagellates (zooxanthellae), bacteria, and other microbes. Due to the complex interactions in this so-called coral holobiont, it has proven difficult to understand the environmental limitations of productivity in corals. Among others, the micronutrient iron has been proposed to limit primary productivity due to its essential role in photosynthesis and bacterial processes. Here, we tested the effect of iron enrichment on the physiology of the coral Pocillopora verrucosa from the central Red Sea during a 12-day experiment. Contrary to previous reports, we did not see an increase in zooxanthellae population density or gross photosynthesis. Conversely, respiration rates were significantly increased, and microbial nitrogen fixation was significantly decreased. Taken together, our data suggest that iron is not a limiting factor of primary productivity in Red Sea corals. Rather, increased metabolic demands in response to iron enrichment, as evidenced by increased respiration rates, may reduce carbon (i.e., energy) availability in the coral holobiont, resulting in reduced microbial nitrogen fixation. This decrease in nitrogen supply in turn may exacerbate the limitation of other nutrients, creating a negative feedback loop. Thereby, our results highlight that the effects of iron enrichment appear to be strongly dependent on local environmental conditions and ultimately may depend on the availability of other nutrients.

  8. Enrichment and Isolation of Rumen Bacteria That Reduce trans- Aconitic Acid to Tricarballylic Acid

    PubMed Central

    Russell, James B.

    1985-01-01

    Bacteria from the bovine rumen capable of reducing trans-aconitate to tricarballylate were enriched in an anaerobic chemostat containing rumen fluid medium and aconitate. After 9 days at a dilution rate of 0.07 h−1, the medium was diluted and plated in an anaerobic glove box. Three types of isolates were obtained from the plates (a crescent-shaped organism, a pleomorphic rod, and a spiral-shaped organism), and all three produced tricarballylate in batch cultures that contained glucose and trans-aconitate. In glucose-limited chemostats (0.10 h−1), trans-aconitate reduction was associated with a decrease in the amount of reduced products formed from glucose. The crescent-shaped organism produced less propionate, the pleomorphic rod produced less ethanol, and the spiral made less succinate and possibly H2. Aconitate reduction by the pleomorphic rod and the spiral organism was associated with a significant increase in cellular dry matter. Experiments with stock cultures of predominant rumen bacteria indicated that Selenomonas ruminantium, a species taxonomically similar to the crescent-shaped isolate, was an active reducer of trans-aconitate. Strains of Bacteroides ruminicola, Butyrivibrio fibrisolvens, and Megasphaera elsdenii produced little if any tricarballylate. Wolinella succinogenes produced some tricarballylate. Based on its stability constant for magnesium (Keq = 115), tricarballylate could be a factor in the hypomagnesemia that leads to grass tetany. Images PMID:16346691

  9. Obeticholic acid reduces bacterial translocation and inhibits intestinal inflammation in cirrhotic rats.

    PubMed

    Úbeda, María; Lario, Margaret; Muñoz, Leticia; Borrero, María-José; Rodríguez-Serrano, Macarena; Sánchez-Díaz, Ana-María; Del Campo, Rosa; Lledó, Lourdes; Pastor, Óscar; García-Bermejo, Laura; Díaz, David; Álvarez-Mon, Melchor; Albillos, Agustín

    2016-05-01

    In advanced cirrhosis, gut bacterial translocation is the consequence of intestinal barrier disruption and leads to bacterial infection. Bile acid abnormalities in cirrhosis could play a role in the integrity of the intestinal barrier and the control of microbiota, mainly through the farnesoid X receptor. We investigated the long-term effects of the farnesoid X receptor agonist, obeticholic acid, on gut bacterial translocation, intestinal microbiota composition, barrier integrity and inflammation in rats with CCl4-induced cirrhosis with ascites. Cirrhotic rats received a 2-week course of obeticholic acid or vehicle starting once ascites developed. We then determined: bacterial translocation by mesenteric lymph node culture, ileum expression of antimicrobial peptides and tight junction proteins by qPCR, fecal albumin loss, enteric bacterial load and microbiota composition by qPCR and pyrosequencing of ileum mucosa-attached contents, and intestinal inflammation by cytometry of the inflammatory infiltrate. Obeticholic acid reduced bacterial translocation from 78.3% to 33.3% (p<0.01) and upregulated the expression of the farnesoid X receptor-associated gene small heterodimer partner. Treatment improved ileum expression of antimicrobial peptides, angiogenin-1 and alpha-5-defensin, tight junction proteins zonulin-1 and occludin, and reduced fecal albumin loss and liver fibrosis. Enteric bacterial load normalized, and the distinctive mucosal microbiota of cirrhosis was reduced. Gut immune cell infiltration was reduced and inflammatory cytokine and Toll-like receptor 4 expression normalized. In ascitic cirrhotic rats, obeticholic acid reduces gut bacterial translocation via several complementary mechanisms at the intestinal level. This agent could be used as an alternative to antibiotics to prevent bacterial infection in cirrhosis. Copyright © 2016 European Association for the Study of the Liver. Published by Elsevier B.V. All rights reserved.

  10. Sulfur isotope enrichment during maintenance metabolism in the thermophilic sulfate-reducing bacterium Desulfotomaculum putei.

    PubMed

    Davidson, Mark M; Bisher, M E; Pratt, Lisa M; Fong, Jon; Southam, Gordon; Pfiffner, Susan M; Reches, Z; Onstott, Tullis C

    2009-09-01

    Values of Delta(34)S (=delta(34)S(HS)-delta(34)S(SO(4)), where delta(34)S(HS) and delta(34)S(SO(4)) indicate the differences in the isotopic compositions of the HS(-) and SO(4)(2-) in the eluent, respectively) for many modern marine sediments are in the range of -55 to -75 per thousand, much greater than the -2 to -46 per thousand epsilon(34)S (kinetic isotope enrichment) values commonly observed for microbial sulfate reduction in laboratory batch culture and chemostat experiments. It has been proposed that at extremely low sulfate reduction rates under hypersulfidic conditions with a nonlimited supply of sulfate, isotopic enrichment in laboratory culture experiments should increase to the levels recorded in nature. We examined the effect of extremely low sulfate reduction rates and electron donor limitation on S isotope fractionation by culturing a thermophilic, sulfate-reducing bacterium, Desulfotomaculum putei, in a biomass-recycling culture vessel, or "retentostat." The cell-specific rate of sulfate reduction and the specific growth rate decreased progressively from the exponential phase to the maintenance phase, yielding average maintenance coefficients of 10(-16) to 10(-18) mol of SO(4) cell(-1) h(-1) toward the end of the experiments. Overall S mass and isotopic balance were conserved during the experiment. The differences in the delta(34)S values of the sulfate and sulfide eluting from the retentostat were significantly larger, attaining a maximum Delta(34)S of -20.9 per thousand, than the -9.7 per thousand observed during the batch culture experiment, but differences did not attain the values observed in marine sediments.

  11. Nitrogen enriched combustion of a natural gas internal combustion engine to reduce NO.sub.x emissions

    DOEpatents

    Biruduganti, Munidhar S.; Gupta, Sreenath Borra; Sekar, R. Raj; McConnell, Steven S.

    2008-11-25

    A method and system for reducing nitrous oxide emissions from an internal combustion engine. An input gas stream of natural gas includes a nitrogen gas enrichment which reduces nitrous oxide emissions. In addition ignition timing for gas combustion is advanced to improve FCE while maintaining lower nitrous oxide emissions.

  12. Environmental enrichment reduces cocaine seeking and reinstatement induced by cues and stress but not by cocaine

    PubMed Central

    Chauvet, Claudia; Lardeux, Virginie; Goldberg, Steven R.; Jaber, Mohamed; Solinas, Marcello

    2011-01-01

    Whereas previous studies have focused on the preventive effects of enriched environments (EE) in drug addiction, in a recent study we suggested that EE can also have “curative” effects. In fact, we found that cocaine addiction-related behaviors can be eliminated by housing cocaine-treated mice in EE during periods of forced abstinence. However, those results were obtained with two simple models of addiction, conditioned place preference (CPP) and behavioral sensitization. In this study, we used intravenous drug self-administration procedures in rats to further investigate the beneficial effects of EE on cocaine addiction in a reinstatement model of relapse. Singly housed rats learned to self-administer cocaine during 10 consecutive daily sessions (0.6 mg/injection, 6h/day). They were then housed three per cage in either standard environments (SE) or EE and were kept abstinent in the animal facility until testing for extinction and reinstatement. We found that 30 days of EE significantly and consistently reduced cocaine seeking during a 6-h extinction session. In addition, EE significantly reduced cue- and stress-induced reinstatement. Surprisingly, given our previous results in mice with CPP, EE did not reduce cocaine-induced reinstatement regardless of the level of exposure to cocaine and the duration of the period of abstinence and exposure to EE. Altogether, these results support the hypothesis that EE can reduce cocaine-induced craving and highlight the importance of positive life conditions in facilitating abstinence and preventing relapse to cocaine addiction. PMID:19741591

  13. Blueberry polyphenol-enriched soybean flour reduces hyperglycemia, body weight gain and serum cholesterol in mice.

    PubMed

    Roopchand, Diana E; Kuhn, Peter; Rojo, Leonel E; Lila, Mary Ann; Raskin, Ilya

    2013-02-01

    Defatted soybean flour (DSF) can sorb and concentrate blueberry anthocyanins and other polyphenols, but not sugars. In this study blueberry polyphenol-enriched DSF (BB-DSF) or DSF were incorporated into very high fat diet (VHFD) formulations and provided ad libitum to obese and hyperglycemic C57BL/6 mice for 13 weeks to investigate anti-diabetic effects. Compared to the VHFD containing DSF, the diet supplemented with BB-DSF reduced weight gain by 5.6%, improved glucose tolerance, and lowered fasting blood glucose levels in mice within 7 weeks of intervention. Serum cholesterol of mice consuming the BB-DSF-supplemented diet was 13.2% lower than mice on the diet containing DSF. Compounds were eluted from DSF and BB-DSF for in vitro assays of glucose production and uptake. Compared to untreated control, doses of BB-DSF eluate containing 0.05-10μg/μL of blueberry anthocyanins significantly reduced glucose production by 24-74% in H4IIE rat hepatocytes, but did not increase glucose uptake in L6 myotubes. The results indicate that delivery of blueberry polyphenols stabilized in a high-protein food matrix may be useful for the dietary management of pre-diabetes and/or diabetes. Copyright © 2012 Elsevier Ltd. All rights reserved.

  14. Effectiveness of a walnut-enriched diet on murine sperm: involvement of reduced peroxidative damage.

    PubMed

    Coffua, Lauren S; Martin-DeLeon, Patricia A

    2017-02-01

    A walnut supplement for a Western-style diet in men was shown to improve sperm motility, vitality, and morphology. To gain further insights into factors underlying this improvement, we administered a parallel walnut-enriched diet to mice [including those with a defect in sperm motility due to deletion of Plasma Membrane Ca(2+)-ATPase 4 (Pmca4(-/-) )] to determine if there is a similar improvement that is accompanied by reduced sperm membrane peroxidative damage. Although sperm vitality and acrosome reaction rate were unaffected, the diet led to a significant improvement in motility (P < 0.05) and morphology (P < 0.04) in wild-type sperm and in morphology (P < 0.01) in Pmca4(-/-) , confirming the diet's efficacy, which appeared to be more modest in mice than in humans. In both strains of mice, the diet resulted in a significant decrease in sperm lipid peroxidation (oxidative stress) levels, but did not rescue the significantly increased apoptotic levels seen in the testis and epididymis of Pmca4 nulls. Our findings support the effectiveness of walnuts on sperm quality, associated with reduced peroxidative damage; and suggest that oxidative stress is involved in the mechanism(s) underlying male reproductive defects in Pmca4(-/-) .

  15. Blueberry polyphenol-enriched soybean flour reduces hyperglycemia, body weight gain and serum cholesterol in mice

    PubMed Central

    Roopchand, Diana E.; Kuhn, Peter; Rojo, Leonel E.; Lila, Mary Ann; Raskin, Ilya

    2013-01-01

    Defatted soybean flour (DSF) can sorb and concentrate blueberry anthocyanins and other polyphenols, but not sugars. In this study blueberry polyphenol-enriched DSF (BB-DSF) or DSF were incorporated into very high fat diet (VHFD) formulations and provided ad libitum to obese and hyperglycemic C57BL/6 mice for 13 weeks to investigate anti-diabetic effects. Compared to the VHFD containing DSF, the diet supplemented with BB-DSF reduced weight gain by 5.6%, improved glucose tolerance, and lowered fasting blood glucose levels in mice within 7 weeks of intervention. Serum cholesterol of mice consuming the BB-DSF-supplemented diet was 13.2% lower than mice on the diet containing DSF. Compounds were eluted from DSF and BB-DSF for in vitro assays of glucose production and uptake. Compared to untreated control, doses of BB-DSF eluate containing 0.05 – 10 μg/μL of blueberry anthocyanins significantly reduced glucose production by 24% - 74% in H4IIE rat hepatocytes, but did not increase glucose uptake in L6 myotubes. The results indicate that delivery of blueberry polyphenols stabilized in a high-protein food matrix may be useful for the dietary management of pre-diabetes and/or diabetes. PMID:23220243

  16. Effect of organic acids production and bacterial community on the possible mechanism of phosphorus solubilization during composting with enriched phosphate-solubilizing bacteria inoculation.

    PubMed

    Wei, Yuquan; Zhao, Yue; Shi, Mingzi; Cao, Zhenyu; Lu, Qian; Yang, Tianxue; Fan, Yuying; Wei, Zimin

    2017-09-19

    Enriched phosphate-solubilizing bacteria (PSB) agent were acquired by domesticated cultivation, and inoculated into kitchen waste composting in different stages. The effect of different treatments on organic acids production, tricalcium phosphate (TCP) solubilization and their relationship with bacterial community were investigated during composting. Our results pointed out that inoculation affected pH, total acidity and the production of oxalic, lactic, citric, succinic, acetic and formic acids. We also found a strong advantage in the solubilization of TCP and phosphorus (P) availability for PSB inoculation especially in the cooling stage. Redundancy analysis and structural equation models demonstrated inoculation by different methods changed the correlation of the bacterial community composition with P fractions as well as organic acids, and strengthened the cooperative function related to P transformation among species during composting. Finally, we proposed a possible mechanism of P solubilization with enriched PSB inoculation, which was induced by bacterial community and organic acids production. Copyright © 2017 Elsevier Ltd. All rights reserved.

  17. Atrazine biodegradation efficiency, metabolite detection, and trzD gene expression by enrichment bacterial cultures from agricultural soil

    PubMed Central

    Solomon, Robinson David Jebakumar; Kumar, Amit; Satheeja Santhi, Velayudhan

    2013-01-01

    Atrazine is a selective herbicide used in agricultural fields to control the emergence of broadleaf and grassy weeds. The persistence of this herbicide is influenced by the metabolic action of habituated native microorganisms. This study provides information on the occurrence of atrazine mineralizing bacterial strains with faster metabolizing ability. The enrichment cultures were tested for the biodegradation of atrazine by high-performance liquid chromatography (HPLC) and mass spectrometry. Nine cultures JS01.Deg01 to JS09.Deg01 were identified as the degrader of atrazine in the enrichment culture. The three isolates JS04.Deg01, JS07.Deg01, and JS08.Deg01 were identified as efficient atrazine metabolizers. Isolates JS04.Deg01 and JS07.Deg01 produced hydroxyatrazine (HA) N-isopropylammelide and cyanuric acid by dealkylation reaction. The isolate JS08.Deg01 generated deethylatrazine (DEA), deisopropylatrazine (DIA), and cyanuric acid by N-dealkylation in the upper degradation pathway and later it incorporated cyanuric acid in their biomass by the lower degradation pathway. The optimum pH for degrading atrazine by JS08.Deg01 was 7.0 and 16S rDNA phylogenetic typing identified it as Enterobacter cloacae strain JS08.Deg01. The highest atrazine mineralization was observed in case of isolate JS08.Deg01, where an ample amount of trzD mRNA was quantified at 72 h of incubation with atrazine. Atrazine bioremediating isolate E. cloacae strain JS08.Deg01 could be the better environmental remediator of agricultural soils and the crop fields contaminated with atrazine could be the source of the efficient biodegrading microbial strains for the environmental cleanup process. PMID:24302716

  18. Atrazine biodegradation efficiency, metabolite detection, and trzD gene expression by enrichment bacterial cultures from agricultural soil.

    PubMed

    Solomon, Robinson David Jebakumar; Kumar, Amit; Satheeja Santhi, Velayudhan

    2013-12-01

    Atrazine is a selective herbicide used in agricultural fields to control the emergence of broadleaf and grassy weeds. The persistence of this herbicide is influenced by the metabolic action of habituated native microorganisms. This study provides information on the occurrence of atrazine mineralizing bacterial strains with faster metabolizing ability. The enrichment cultures were tested for the biodegradation of atrazine by high-performance liquid chromatography (HPLC) and mass spectrometry. Nine cultures JS01.Deg01 to JS09.Deg01 were identified as the degrader of atrazine in the enrichment culture. The three isolates JS04.Deg01, JS07.Deg01, and JS08.Deg01 were identified as efficient atrazine metabolizers. Isolates JS04.Deg01 and JS07.Deg01 produced hydroxyatrazine (HA) N-isopropylammelide and cyanuric acid by dealkylation reaction. The isolate JS08.Deg01 generated deethylatrazine (DEA), deisopropylatrazine (DIA), and cyanuric acid by N-dealkylation in the upper degradation pathway and later it incorporated cyanuric acid in their biomass by the lower degradation pathway. The optimum pH for degrading atrazine by JS08.Deg01 was 7.0 and 16S rDNA phylogenetic typing identified it as Enterobacter cloacae strain JS08.Deg01. The highest atrazine mineralization was observed in case of isolate JS08.Deg01, where an ample amount of trzD mRNA was quantified at 72 h of incubation with atrazine. Atrazine bioremediating isolate E. cloacae strain JS08.Deg01 could be the better environmental remediator of agricultural soils and the crop fields contaminated with atrazine could be the source of the efficient biodegrading microbial strains for the environmental cleanup process.

  19. Lactulose reduces bacterial DNA translocation, which worsens neurocognitive shape in cirrhotic patients with minimal hepatic encephalopathy.

    PubMed

    Moratalla, Alba; Ampuero, Javier; Bellot, Pablo; Gallego-Durán, Rocío; Zapater, Pedro; Roger, Manuela; Figueruela, Blanca; Martínez-Moreno, Belén; González-Navajas, José M; Such, José; Romero-Gómez, Manuel; Francés, Rubén

    2017-02-01

    Minimal hepatic encephalopathy is associated with poor prognosis and mortality in patients with cirrhosis. We aimed at investigating whether bacterial-DNA translocation affects hyperammonaemia and neurocognitive scores in patients with mHE according to the use of lactulose. Observational study including 72 mHE cirrhotic patients, as defined by a psychometric hepatic encephalopathy score (PHES)<-4 and/or a critical flicker frequency (CFF)<39 Hz. Bacterial-DNA, serum ammonia, pro-inflammatory cytokines and nitric oxide levels were evaluated. A second cohort of 40 lactulose-untreated patients were evaluated before and 6-month after lactulose administration (30-60 mL/d). In the first cohort, bacterial-DNA rate was significantly higher in patients without lactulose (39% vs 23%, P=.03). Serum ammonia and inflammatory markers were significantly increased in patients with bacterial-DNA, regardless the use of lactulose, and correlated with the amount of amplified bacterial-DNA. Neurocognitive scores were significantly worse in bacterial-DNA positive vs negative patients (PHES -7.6±1.1 vs -5.5±1.0; CFF 32.5±2.6 vs 36.2±2.8, P=.01). Lactulose was associated with improved neurocognitive scores in patients without bacterial-DNA. Serum ammonia levels inversely correlated with neurocognitive scores in patients with bacterial-DNA (PHES r=-.84; CFF r=-.72, P=.001). In the second cohort, lactulose reduced bacterial-DNA translocation (36%-16%, P=.02). Neurocognitive scores were significantly improved in bacterial-DNA positive patients who cleared bacterial-DNA during the period on lactulose. Serum ammonia levels correlated with both neurocognitive scores in patients with bacterial-DNA, either before or after lactulose. Bacterial-DNA translocation worsens neurocognitive scores in mHE patients and it is reduced by lactulose, enhancing the relevance of controlling bacterial antigen translocation in these patients. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  20. Production and characterisation of reduced-fat and PUFA-enriched Burrata cheese.

    PubMed

    Trani, Antonio; Gambacorta, Giuseppe; Gomes, Tommaso F; Loizzo, Pasqua; Cassone, Angela; Faccia, Michele

    2016-05-01

    Burrata is an Italian fresh 'pasta filata' cheese made from cow's milk and cream that is rapidly spreading in Europe. It has very high caloric content, and a technological protocol was developed for producing a reduced-fat type and fortifying it with polyunsaturated fatty acids (PUFA) of vegetable origin. A satisfactory reduced-fat prototype was obtained by using a 14% fat cream, which was specifically developed by diluting double cream with a suspension of carob seed flour. The composition of the new cheese changed with respect to the control, but the sensory characteristics were not impaired. Moisture increased from 62·6 to 68·4%, fat on dry matter decreased from 59·1 to 34·7%, and the caloric content decreased from 1060·8 to 718 J/100 g. Proteolysis and lipolysis were not affected by the technological modifications: after 7 d storage, the electrophoretic pattern of caseins and the free fatty acids profile of experimental and control cheeses were not significantly different. Fortification of reduced-fat Burrata with PUFA was obtained by using two commercial formulates available at a compatible price with the current economic values of the cheese. The two formulates derived from flaxseeds and Carthamus tinctorius oil and allowed enrichment in C18 :3 : n3 (α-linolenic acid, ALA), and 9cis,11trans- and 10trans,12cis- conjugated linoleic acid (CLA), respectively. Fortification was easy to perform under a technical point of view, but the negative sensory impact limited fortification at a maximum of 7·0 mg g-1 fat ALA and 6·8 g-1 fat CLA.

  1. REDUCED STOMATAL CONDUCTANCE IN SWEETGUM (LIQUIDAMBAR STYRACIFLUA) SUSTAINED OVER LONG-TERM CO2 ENRICHMENT

    EPA Science Inventory

    Over four years (1998-2001), we examined the effects of CO2 enrichment on stomatal conductance (gs) of sun and shade leaves of overstory sweetgum (Liquidambar styraciflua L.) grown at the Duke Forest Free Air Carbon CO2 Enrichment (FACE) experiment. Gas exchange measurements were...

  2. REDUCED STOMATAL CONDUCTANCE IN SWEETGUM (LIQUIDAMBAR STYRACIFLUA) SUSTAINED OVER LONG-TERM CO2 ENRICHMENT

    EPA Science Inventory

    Over four years (1998-2001), we examined the effects of CO2 enrichment on stomatal conductance (gs) of sun and shade leaves of overstory sweetgum (Liquidambar styraciflua L.) grown at the Duke Forest Free Air Carbon CO2 Enrichment (FACE) experiment. Gas exchange measurements were...

  3. Does Environmental Enrichment Reduce Stress? An Integrated Measure of Corticosterone from Feathers Provides a Novel Perspective

    PubMed Central

    Fairhurst, Graham D.; Frey, Matthew D.; Reichert, James F.; Szelest, Izabela; Kelly, Debbie M.; Bortolotti, Gary R.

    2011-01-01

    Enrichment is widely used as tool for managing fearfulness, undesirable behaviors, and stress in captive animals, and for studying exploration and personality. Inconsistencies in previous studies of physiological and behavioral responses to enrichment led us to hypothesize that enrichment and its removal are stressful environmental changes to which the hormone corticosterone and fearfulness, activity, and exploration behaviors ought to be sensitive. We conducted two experiments with a captive population of wild-caught Clark's nutcrackers (Nucifraga columbiana) to assess responses to short- (10-d) and long-term (3-mo) enrichment, their removal, and the influence of novelty, within the same animal. Variation in an integrated measure of corticosterone from feathers, combined with video recordings of behaviors, suggests that how individuals perceive enrichment and its removal depends on the duration of exposure. Short- and long-term enrichment elicited different physiological responses, with the former acting as a stressor and birds exhibiting acclimation to the latter. Non-novel enrichment evoked the strongest corticosterone responses of all the treatments, suggesting that the second exposure to the same objects acted as a physiological cue, and that acclimation was overridden by negative past experience. Birds showed weak behavioral responses that were not related to corticosterone. By demonstrating that an integrated measure of glucocorticoid physiology varies significantly with changes to enrichment in the absence of agonistic interactions, our study sheds light on potential mechanisms driving physiological and behavioral responses to environmental change. PMID:21412426

  4. Environmental enrichment reduces methamphetamine cue-induced reinstatement but does not alter methamphetamine reward or VMAT2 function

    PubMed Central

    Hofford, Rebecca S.; Darna, Mahesh; Wilmouth, Carrie E.; Dwoskin, Linda P.; Bardo, Michael T.

    2014-01-01

    Environmental factors influence a variety of health-related outcomes. In general, being raised in an environment possessing social, sensory, and motor enrichment reduces the rewarding effects of various drugs, thus protecting against abuse vulnerability. However, in the case of methamphetamine (METH), which acts at the vesicular monoamine transporter 2 (VMAT2) to enhance dopamine release from the cytosol, previous evidence suggests that METH reward may not be altered by environmental enrichment. This study examined the influence of an enriched environment on measures of METH reward, METH seeking, and VMAT2 function. Rats were raised from weaning to adulthood in either an enriched environment (presence of social cohorts and novel objects) or an isolated environment (no cohorts or novel objects). Rats in these two conditions were subsequently tested for their acquisition of conditioned place preference (CPP), METH self-administration, maintenance of self-administration at various unit doses of METH (0.001–0.5 mg/kg/infusion), and cue-induced reinstatement. VMAT2 function in striatum from these two groups also was assessed. No significant environment effects were found in CPP or METH self-administration, which paralleled a lack of effect in VMAT2 function between groups. However, cue-induced reinstatement was reduced by environmental enrichment. Together, these results suggest that environmental enrichment does not alter VMAT2 function involved in METH reward. However, the enrichment-induced decrease in cue-induced reinstatement indicates that enrichment may have a beneficial effect against relapse following a period of extinction via a neural mechanism other than striatal VMAT2 function. PMID:24821405

  5. Environmental enrichment reduces methamphetamine cue-induced reinstatement but does not alter methamphetamine reward or VMAT2 function.

    PubMed

    Hofford, Rebecca S; Darna, Mahesh; Wilmouth, Carrie E; Dwoskin, Linda P; Bardo, Michael T

    2014-08-15

    Environmental factors influence a variety of health-related outcomes. In general, being raised in an environment possessing social, sensory, and motor enrichment reduces the rewarding effects of various drugs, thus protecting against abuse vulnerability. However, in the case of methamphetamine (METH), which acts at the vesicular monoamine transporter 2 (VMAT2) to enhance dopamine release from the cytosol, previous evidence suggests that METH reward may not be altered by environmental enrichment. This study examined the influence of an enriched environment on measures of METH reward, METH seeking, and VMAT2 function. Rats were raised from weaning to adulthood in either an enriched environment (presence of social cohorts and novel objects) or an isolated environment (no cohorts or novel objects). Rats in these two conditions were subsequently tested for their acquisition of conditioned place preference (CPP), METH self-administration, maintenance of self-administration at various unit doses of METH (0.001-0.5mg/kg/infusion), and cue-induced reinstatement. VMAT2 function in striatum from these two groups also was assessed. No significant environment effects were found in CPP or METH self-administration, which paralleled a lack of effect in VMAT2 function between groups. However, cue-induced reinstatement was reduced by environmental enrichment. Together, these results suggest that environmental enrichment does not alter VMAT2 function involved in METH reward. However, the enrichment-induced decrease in cue-induced reinstatement indicates that enrichment may have a beneficial effect against relapse following a period of extinction via a neural mechanism other than striatal VMAT2 function. Copyright © 2014 Elsevier B.V. All rights reserved.

  6. Can Halogen Enrichment in Reduced Enstatite Chondrites Provide Clues to Volatile Accretion in the Early Earth?

    NASA Astrophysics Data System (ADS)

    Clay, P. L.; Burgess, R.; Busemann, H.; Ruzié, L.; Joachim, B.; Ballentine, C.

    2013-12-01

    Understanding how the Earth obtained and ultimately retained its volatiles is important for our overall understanding of large scale planetary evolution. Numerous models exist for the heterogeneous accretion of volatiles to early Earth, but accounting for all elements through accretion of typical planetary building blocks (e.g., CI chondrites) is difficult. Proto-planetary collisions resulting in the accretion of volatile-poor material under reducing conditions followed by accretion of volatile-rich material under oxidizing conditions has been suggested in such models [e.g., 1]. The heavy halogens (Cl, Br and I), a group of moderately volatile elements, are excellent tracers of planetary processing due to their low abundance and incompatible nature. Therefore characterizing halogen abundance and distribution in materials that accreted to form the planets, e.g., primitive meteorites, is crucial. One group of primitive meteorites, the enstatite chondrites (EC's), are amongst the most reduced materials in the solar system as evidenced by their unique mineral assemblage. Yet despite forming under ultra-reducing conditions, they are enriched in the moderately volatile elements, such as the halogens. The ECs are of particular interest owing to their oxygen isotopic composition which plots along the terrestrial fractionation line, linking them isotopically to the Earth-Moon system. These samples can thus potentially provide clues on the accretion of moderately volatile element rich material under reducing conditions, such as it may have existed during the early stages of Earth's accretion. Chlorine, Br and I concentrations in ECs were determined through step-heating small neutron-irradiated samples (0.3 to 3.3 mg) and measured by mass spectrometry using the noble gas proxy isotopes 38ArCl/Cl, 80KrBr/Br and 128XeI/I. The EH chondrites are consistently enriched in the heavy halogens (up to 330 ppm Cl, 2290 ppb Br and 180 ppb I), compared to other ordinary and carbonaceous

  7. Speciation and enrichment of arsenic in strongly reducing shallow aquifers at western Hetao Plain, northern China

    NASA Astrophysics Data System (ADS)

    Deng, Yamin; Wang, Yanxin; Ma, Teng; Gan, Yiqun

    2009-02-01

    High arsenic (As) groundwater is widely distributed in northwestern Hetao Plain, an arid region with sluggish groundwater flow. Observed As concentration in groundwater from wells ranges from 76 to 1,093 μg/l. Most water samples have high total dissolved solids, with Cl and HCO3 as the dominant anions and Na as the dominant cation. The major hydrochemical types of most saline groundwaters are Na-Mg-Cl-HCO3 and Na-Mg-Cl. By contrast, fresh groundwaters generally belong to the Na-Mg-HCO3 type. High concentrations of arsenic in shallow aquifers are associated with strongly reducing conditions, as evidenced by high concentrations of dissolved organic carbon, ammonium, as well as dissolved sulfide and Fe, dominance of arsenite, relatively low concentrations of nitrate and sulfate, and occasionally high content of dissolved methane (CH4). High As groundwaters from different places at Hetao Plain experienced different redox processes. Fluoride is also present in high As groundwater, ranging between 0.40 and 3.36 mg/l. Although fluorosis poses an additional health problem in the region, it does not correlate well with As in spatial distribution. Geochemical analysis indicates that evapotranspiration is an important process controlling the enrichment of Na and Cl, as well as trace elements such as As, B, and Br in groundwater.

  8. Chitosan Enriched Three-Dimensional Matrix Reduces Inflammatory and Catabolic Mediators Production by Human Chondrocytes

    PubMed Central

    Oprenyeszk, Frederic; Sanchez, Christelle; Dubuc, Jean-Emile; Maquet, Véronique; Henrist, Catherine; Compère, Philippe; Henrotin, Yves

    2015-01-01

    This in vitro study investigated the metabolism of human osteoarthritic (OA) chondrocytes encapsulated in a spherical matrix enriched of chitosan. Human OA chondrocytes were encapsulated and cultured for 28 days either in chitosan-alginate beads or in alginate beads. The beads were formed by slowly passing dropwise either the chitosan 0.6%–alginate 1.2% or the alginate 1.2% solution through a syringe into a 102 mM CaCl2 solution. Beads were analyzed histologically after 28 days. Interleukin (IL)-6 and -8, prostaglandin (PG) E2, matrix metalloproteinases (MMPs), hyaluronan and aggrecan were quantified directly in the culture supernatant by specific ELISA and nitric oxide (NO) by using a colorimetric method based on the Griess reaction. Hematoxylin and eosin staining showed that chitosan was homogeneously distributed through the matrix and was in direct contact with chondrocytes. The production of IL-6, IL-8 and MMP-3 by chondrocytes significantly decreased in chitosan-alginate beads compared to alginate beads. PGE2 and NO decreased also significantly but only during the first three days of culture. Hyaluronan and aggrecan production tended to increase in chitosan-alginate beads after 28 days of culture. Chitosan-alginate beads reduced the production of inflammatory and catabolic mediators by OA chondrocytes and tended to stimulate the synthesis of cartilage matrix components. These particular effects indicate that chitosan-alginate beads are an interesting scaffold for chondrocytes encapsulation before transplantation to repair cartilage defects. PMID:26020773

  9. Prior exposure to enriched environment reduces nitric oxide synthase after transient MCAO in rats.

    PubMed

    Yu, Kewei; Wu, Yi; Hu, Yongshan; Zhang, Qi; Xie, Hongyu; Liu, Gang; Chen, Yao; Guo, Zhenzhen; Jia, Jie

    2013-12-01

    Increasing evidence shows that exposure to an enriched environment (EE) after cerebral ischemia/reperfusion injury is neuroprotective in animal models. However, little is known about of the neuroprotective effects of EE exposure prior to injury. The current study examined the effects of prior EE exposure on inducible and neuronal nitric oxide syntheses (iNOS and nNOS) after transient middle cerebral artery occlusion (tMCAO) in rats. A total of 72 rats were exposed to EE or standard housing condition (SC) for 1 month, followed by 90-min MCAO and reperfusion or sham surgery, leading to the following three groups: (1) EE+MCAO (n=24), (2) SC+MCAO (n=24), (3) SC+sham (n=24). Rats were sacrificed at 1, 6, or 24h after MCAO (n=6/group) for iNOS and nNOS mRNA quantification by real-time PCR and at 24h after MCAO (n=6/group) for iNOS and nNOS protein quantification by Western blot or were evaluated for neurological function outcomes, then sacrificed to assess infarct volume (n=6/group). Results showed that prior exposure to EE reduced iNOS and nNOS mRNA and protein and improved neurological status after MCAO without affecting infarct volume, suggesting that EE may provide neuroprotection via ischemic preconditioning.

  10. The Role of Enriched Microbial Consortium on Iron-Reducing Bioaugmentation in Sediments.

    PubMed

    Pan, Yuanyuan; Yang, Xunan; Xu, Meiying; Sun, Guoping

    2017-01-01

    Microbial iron reduction is an important biogeochemical process and involved in various engineered processes, including the traditional clay dyeing processes. Bioaugmentation with iron reducing bacteria (IRB) is generally considered as an effective method to enhance the activity of iron reduction. However, limited information is available about the role of IRB on bioaugmentation. To reveal the roles of introduced IRB on bioaugmentation, an IRB consortium enriched with ferric citrate was inoculated into three Fe(II)-poor sediments which served as the pigments for Gambiered Guangdong silk dyeing. After bioaugmentation, the dyeabilities of all sediments met the demands of Gambiered Guangdong silk through increasing the concentration of key agent [precipitated Fe(II)] by 35, 27, and 61%, respectively. The microbial community analysis revealed that it was the minor species but not the dominant ones in the IRB consortium that promoted the activity of iron reduction. Meanwhile, some indigenous bacteria with the potential of iron reduction, such as Clostridium, Anaeromyxobacter, Bacillus, Pseudomonas, Geothrix, and Acinetobacter, were also stimulated to form mutualistic interaction with introduced consortium. Interestingly, the same initial IRB consortium led to the different community successions among the three sediments and there was even no common genus increasing or decreasing synchronously among the potential IRB of all bioaugmented sediments. The Mantel and canonical correspondence analysis showed that different physiochemical properties of sediments influenced the microbial community structures. This study not only provides a novel bioremediation method for obtaining usable sediments for dyeing Gambiered Guangdong silk, but also contributes to understanding the microbial response to IRB bioaugmentation.

  11. Bacterial siderophores promote dissolution of UO2 under reducing conditions.

    PubMed

    Frazier, Scott W; Kretzschmar, Ruben; Kraemer, Stephan M

    2005-08-01

    Tetravalent actinides are often considered environmentally immobile due to their strong hydrolysis and formation of sparingly soluble oxide phases. However, biogenic ligands commonly found in the soil environment may increase their solubility and mobility. We studied the adsorption and dissolution kinetics of UO2 in the presence of a microbial siderophore, desferrioxamine-B (DFO-B), under reducing conditions. Using batch and continuous flow stirred tank reactors (CFSTR),we found that DFO-B increases the solubility of UIV and accelerates UO2 dissolution rates through a ligand-promoted dissolution mechanism. DFO-B adsorption to UO2 followed a Langmuir-type isotherm. The maximum adsorbed DFO-B concentrations were 3.3 micromol m(-2) between pH 3 and 8 and declined above pH 8. DFO-B dissolved UO2 at a DFO-B surface-saturated net rate of 64 nmol h(-1) m(-2) (pH 7.5, l = 0.01 M) according to the first-order rate equation R = kL[Lads], with a rate coefficient kL of 0.019 h(-1). Even at very low siderophore concentrations (e.g. 1 microM), net dissolution rates (16 nmol h(-1) m(-2), pH 7.5, l = 0.01 M) were substantially greater than net proton-promoted dissolution rates (3 nmol h(-1) m(-2), pH 7-7.5, l = 0.01 M). Interestingly, adding dissolved FeIII had negligible effects on DFO-B-promoted UO2 dissolution rates, despite its potential as a competitor for DFO-B and as an oxidant of UIV. Our results suggest that strong organic ligands could influence the environmental mobility of tetravalent actinides and should be considered in predictions for nuclear waste storage and remediation strategies.

  12. Multilevel correlations in the biological phosphorus removal process: From bacterial enrichment to conductivity-based metabolic batch tests and polyphosphatase assays.

    PubMed

    Weissbrodt, David G; Maillard, Julien; Brovelli, Alessandro; Chabrelie, Alexandre; May, Jonathan; Holliger, Christof

    2014-12-01

    Enhanced biological phosphorus removal (EBPR) from wastewater relies on the preferential selection of active polyphosphate-accumulating organisms (PAO) in the underlying bacterial community continuum. Efficient management of the bacterial resource requires understanding of population dynamics as well as availability of bioanalytical methods for rapid and regular assessment of relative abundances of active PAOs and their glycogen-accumulating competitors (GAO). A systems approach was adopted here toward the investigation of multilevel correlations from the EBPR bioprocess to the bacterial community, metabolic, and enzymatic levels. Two anaerobic-aerobic sequencing-batch reactors were operated to enrich activated sludge in PAOs and GAOs affiliating with "Candidati Accumulibacter and Competibacter phosphates", respectively. Bacterial selection was optimized by dynamic control of the organic loading rate and the anaerobic contact time. The distinct core bacteriomes mainly comprised populations related to the classes Betaproteobacteria, Cytophagia, and Chloroflexi in the PAO enrichment and of Gammaproteobacteria, Alphaproteobacteria, Acidobacteria, and Sphingobacteria in the GAO enrichment. An anaerobic metabolic batch test based on electrical conductivity evolution and a polyphosphatase enzymatic assay were developed for rapid and low-cost assessment of the active PAO fraction and dephosphatation potential of activated sludge. Linear correlations were obtained between the PAO fraction, biomass specific rate of conductivity increase under anaerobic conditions, and polyphosphate-hydrolyzing activity of PAO/GAO mixtures. The correlations between PAO/GAO ratios, metabolic activities, and conductivity profiles were confirmed by simulations with a mathematical model developed in the aqueous geochemistry software PHREEQC. © 2014 Wiley Periodicals, Inc.

  13. Non-random species loss in bacterial communities reduces antifungal volatile production.

    PubMed

    Hol, W H Gera; Garbeva, Paolina; Hordijk, Cornelis; Hundscheid, P J; Gunnewiek, Paulien J A Klein; Van Agtmaal, Maaike; Kuramae, Eiko E; De Boer, Wietse

    2015-08-01

    The contribution of low-abundance microbial species to soil ecosystems is easily overlooked because there is considerable overlap between metabolic abilities (functional redundancy) of dominant and subordinate microbial species. Here we studied how loss of less abundant soil bacteria affected the production of antifungal volatiles, an important factor in the natural control of soil-borne pathogenic fungi. We provide novel empirical evidence that the loss of soil bacterial species leads to a decline in the production of volatiles that suppress root pathogens. By using dilution-to-extinction for seven different soils we created bacterial communities with a decreasing number of species and grew them under carbon-limited conditions. Communities with high bacterial species richness produced volatiles that strongly reduced the hyphal growth of the pathogen Fusarium oxysporum. For most soil origins loss of bacterial species resulted in loss of antifungal volatile production. Analysis of the volatiles revealed that several known antifungal compounds were only produced in the more diverse bacterial communities. Our results suggest that less abundant bacterial species play an important role in antifungal volatile production by soil bacterial communities and, consequently, in the natural suppression of soil-borne pathogens.

  14. Characterization of Fe (III)-reducing enrichment culture and isolation of Fe (III)-reducing bacterium Enterobacter sp. L6 from marine sediment.

    PubMed

    Liu, Hongyan; Wang, Hongyu

    2016-07-01

    To enrich the Fe (III)-reducing bacteria, sludge from marine sediment was inoculated into the medium using Fe (OH)3 as the sole electron acceptor. Efficiency of Fe (III) reduction and composition of Fe (III)-reducing enrichment culture were analyzed. The results indicated that the Fe (III)-reducing enrichment culture with the dominant bacteria relating to Clostridium and Enterobacter sp. had high Fe (III) reduction of (2.73 ± 0.13) mmol/L-Fe (II). A new Fe (III)-reducing bacterium was isolated from the Fe (III)-reducing enrichment culture and identified as Enterobacter sp. L6 by 16S rRNA gene sequence analysis. The Fe (III)-reducing ability of strain L6 under different culture conditions was investigated. The results indicated that strain L6 had high Fe (III)-reducing activity using glucose and pyruvate as carbon sources. Strain L6 could reduce Fe (III) at the range of NaCl concentrations tested and had the highest Fe (III) reduction of (4.63 ± 0.27) mmol/L Fe (II) at the NaCl concentration of 4 g/L. This strain L6 could reduce Fe (III) with unique properties in adaptability to salt variation, which indicated that it can be used as a model organism to study Fe (III)-reducing activity isolated from marine environment. Copyright © 2015 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

  15. An Enriched Teaching Program for Reducing Resistance and Indices of Unhappiness among Individuals with Profound Multiple Disabilities

    ERIC Educational Resources Information Center

    Green, Carolyn W.; Reid, Dennis H.; Rollyson, Jeannia H.; Passante, Susan C.

    2005-01-01

    We evaluated an enriched teaching program for reducing resistance and indices of unhappiness displayed by 3 individuals with profound multiple disabilities during teaching sessions. The program involved presentation of preferred activities before, during, and after each teaching session, discontinuation of identified nonpreferred activities, and a…

  16. Diet enriched with procyanidins enhances antioxidant activity and reduces myocardial post-ischaemic damage in rats.

    PubMed

    Facino, R M; Carini, M; Aldini, G; Berti, F; Rossoni, G; Bombardelli, E; Morazzoni, P

    1999-01-01

    Aim of this work was to study the efficacy of procyanidins from Vitis vinifera seeds, a standardized mixture of polyphenol antioxidants, on cardiac mechanics following ischemia/reperfusion stunning in the rat, after 3 weeks supplementation. Young and aged male rats were fed a diet enriched with procyanidins complexed (1:3 w/w) with soybean lecithin (2.4%); control animals (CTR-young and CTR-aged) received an equal amount of lecithin and 2 additional groups of animals the standard diet. At the end of the treatment, the total plasma antioxidant defense (TRAP), vitamin E, ascorbic acid and uric acid were determined in plasma and the hearts from all groups of animals subjected to moderate ischemia (flow reduction to 1 ml/min for 20 min) and reperfusion (15 ml/min for 30 min). In both young and aged rats supplemented with procyanidins the recovery of left ventricular developed pressure (LVDP) at the end of reperfusion was 93% (p < 0.01) and 74% (p < 0.01) of the preischemic values and the values of coronary perfusion pressure (CPP) were maintained close to those of the preischemic period. Also creatine kinase (CK) outflow was restrained to baseline levels, while a 2-fold increase in prostacyclin (6-keto-PGF1alpha) in the perfusate from hearts of young and aged rats was elicited during both ischemia and reperfusion. In parallel, procyanidins significantly increased the total antioxidant plasma capacity (by 40% in young and by 30% in aged rats) and the plasma levels of ascorbic acid, while tend to reduce vitamin E levels; no significant differences were observed in uric acid levels. The results of this study demonstrate that procyanidins supplementation in the rat (young and aged) makes the heart less susceptible to ischemia/reperfusion damage and that this is positively associated to an increase in plasma antioxidant activity.

  17. Environmental enrichment strengthens corticocortical interactions and reduces amyloid-β oligomers in aged mice

    PubMed Central

    Mainardi, Marco; Di Garbo, Angelo; Caleo, Matteo; Berardi, Nicoletta; Sale, Alessandro; Maffei, Lamberto

    2013-01-01

    Brain aging is characterized by global changes which are thought to underlie age-related cognitive decline. These include variations in brain activity and the progressive increase in the concentration of soluble amyloid-β (Aβ) oligomers, directly impairing synaptic function and plasticity even in the absence of any neurodegenerative disorder. Considering the high social impact of the decline in brain performance associated to aging, there is an urgent need to better understand how it can be prevented or contrasted. Lifestyle components, such as social interaction, motor exercise and cognitive activity, are thought to modulate brain physiology and its susceptibility to age-related pathologies. However, the precise functional and molecular factors that respond to environmental stimuli and might mediate their protective action again pathological aging still need to be clearly identified. To address this issue, we exploited environmental enrichment (EE), a reliable model for studying the effect of experience on the brain based on the enhancement of cognitive, social and motor experience, in aged wild-type mice. We analyzed the functional consequences of EE on aged brain physiology by performing in vivo local field potential (LFP) recordings with chronic implants. In addition, we also investigated changes induced by EE on molecular markers of neural plasticity and on the levels of soluble Aβ oligomers. We report that EE induced profound changes in the activity of the primary visual and auditory cortices and in their functional interaction. At the molecular level, EE enhanced plasticity by an upward shift of the cortical excitation/inhibition balance. In addition, EE reduced brain Aβ oligomers and increased synthesis of the Aβ-degrading enzyme neprilysin. Our findings strengthen the potential of EE procedures as a non-invasive paradigm for counteracting brain aging processes. PMID:24478697

  18. The Role of Enriched Microbial Consortium on Iron-Reducing Bioaugmentation in Sediments

    PubMed Central

    Pan, Yuanyuan; Yang, Xunan; Xu, Meiying; Sun, Guoping

    2017-01-01

    Microbial iron reduction is an important biogeochemical process and involved in various engineered processes, including the traditional clay dyeing processes. Bioaugmentation with iron reducing bacteria (IRB) is generally considered as an effective method to enhance the activity of iron reduction. However, limited information is available about the role of IRB on bioaugmentation. To reveal the roles of introduced IRB on bioaugmentation, an IRB consortium enriched with ferric citrate was inoculated into three Fe(II)-poor sediments which served as the pigments for Gambiered Guangdong silk dyeing. After bioaugmentation, the dyeabilities of all sediments met the demands of Gambiered Guangdong silk through increasing the concentration of key agent [precipitated Fe(II)] by 35, 27, and 61%, respectively. The microbial community analysis revealed that it was the minor species but not the dominant ones in the IRB consortium that promoted the activity of iron reduction. Meanwhile, some indigenous bacteria with the potential of iron reduction, such as Clostridium, Anaeromyxobacter, Bacillus, Pseudomonas, Geothrix, and Acinetobacter, were also stimulated to form mutualistic interaction with introduced consortium. Interestingly, the same initial IRB consortium led to the different community successions among the three sediments and there was even no common genus increasing or decreasing synchronously among the potential IRB of all bioaugmented sediments. The Mantel and canonical correspondence analysis showed that different physiochemical properties of sediments influenced the microbial community structures. This study not only provides a novel bioremediation method for obtaining usable sediments for dyeing Gambiered Guangdong silk, but also contributes to understanding the microbial response to IRB bioaugmentation. PMID:28373869

  19. A linoleate-enriched cheese product reduces low-density lipoprotein in moderately hypercholesterolemic adults.

    PubMed

    Davis, P A; Platon, J F; Gershwin, M E; Halpern, G M; Keen, C L; DiPaolo, D; Alexander, J; Ziboh, V A

    1993-10-01

    To test the effect of substituting a modified-fat cheese product into the diets of hypercholesterolemic adults. A 4-month, randomized, double-blind, crossover substitution trial. General community outpatient study. Twenty-six healthy adult volunteers (17 men, 9 women) with moderate hypercholesterolemia (total cholesterol > 5.69 mmol/L but < 7.24 mmol/L). Daily substitution of 100 g of cheese, either partial skim-milk mozzarella or modified-fat (vegetable oil) mozzarella cheese product, into participants' normal diets. Participants consumed an assigned cheese for 2 months, at which time they crossed over to consume the other study cheese. Plasma lipid and apolipoprotein levels were measured at baseline and at 2 and 4 months after initiation of the study. Compliance was assessed by body weight and by biweekly dietary records and interviews. No differences in weight or in the amount or type of calories consumed were found during the study. No statistically significant changes in lipid values resulted from consumption of mozzarella cheese. Modified-fat cheese substitution resulted in a decreased low-density lipoprotein cholesterol level when compared with levels at both baseline (-0.28 mmol/L; 95% Cl, -0.14 to -0.42 mmol/L) and during consumption of the skim-milk mozzarella cheese (-0.38 mmol/L; 95% Cl, -0.2 to -0.70 mmol/L). Findings for total cholesterol were similar. High-density lipoprotein cholesterol, plasma triglyceride, and apolipoprotein A-l and B-100 levels were unaltered. Both sexes responded similarly. A linoleate-enriched cheese product, in the absence of any other changes in diet or habits, substituted into the normal diets of hypercholesterolemic adults reduced low-density lipoprotein and plasma cholesterol levels.

  20. A management strategy to reduce bacterial pollution in shellfish areas: A case study

    NASA Astrophysics Data System (ADS)

    Crane, Stuart R.; Moore, James A.

    1986-01-01

    The problem of bacterial pollution in shellfishing areas is not uncommon in the coastal regions of the United States. Bacterial contamination from man's activities can effectively reduce our natural shellfish resource areas by forcing their closure because of high potential risk of diseases being spread by shellfish harvested in these areas. Tillamook Bay, a relatively small, enclosed drainage basin of nonurban character, presents an excellent study area for observing this problem. The high population density of animals, raised on a relatively small floodplain area, represents one of the major sources of pollution in the bay. This paper summarizes the history of the agencies involved with the problem and presents the current approach to alleviate bacterial pollution in the bay without unduly penalizing other industries in the Tillamook basin. The paper also presents some of the legal aspects of reducing water pollution in shellfish harvesting areas and the jurisdiction of federal agencies in these matters. Finally, recommendations are given to reduce bacterial output by the major source categories in the basin, and criteria for bay closure to shellfish harvest are developed to protect the public from bacterially contaminated shellfish.

  1. Identification of bacteria in enrichment cultures of sulfate reducers in the Cariaco Basin water column employing Denaturing Gradient Gel Electrophoresis of 16S ribosomal RNA gene fragments

    PubMed Central

    2013-01-01

    Background The Cariaco Basin is characterized by pronounced and predictable vertical layering of microbial communities dominated by reduced sulfur species at and below the redox transition zone. Marine water samples were collected in May, 2005 and 2006, at the sampling stations A (10°30′ N, 64°40′ W), B (10°40′ N, 64°45′ W) and D (10°43’N, 64°32’W) from different depths, including surface, redox interface, and anoxic zones. In order to enrich for sulfate reducing bacteria (SRB), water samples were inoculated into anaerobic media amended with lactate or acetate as carbon source. To analyze the composition of enrichment cultures, we performed DNA extraction, PCR-DGGE, and sequencing of selected bands. Results DGGE results indicate that many bacterial genera were present that are associated with the sulfur cycle, including Desulfovibrio spp., as well as heterotrophs belonging to Vibrio, Enterobacter, Shewanella, Fusobacterium, Marinifilum, Mariniliabilia, and Spirochaeta. These bacterial populations are related to sulfur coupling and carbon cycles in an environment of variable redox conditions and oxygen availability. Conclusions In our studies, we found an association of SRB-like Desulfovibrio with Vibrio species and other genera that have a previously defined relevant role in sulfur transformation and coupling of carbon and sulfur cycles in an environment where there are variable redox conditions and oxygen availability. This study provides new information about microbial species that were culturable on media for SRB at anaerobic conditions at several locations and water depths in the Cariaco Basin. PMID:23981583

  2. Antibiotic resistance genes and human bacterial pathogens: Co-occurrence, removal, and enrichment in municipal sewage sludge digesters.

    PubMed

    Ju, Feng; Li, Bing; Ma, Liping; Wang, Yubo; Huang, Danping; Zhang, Tong

    2016-03-15

    Understanding which/how antibiotic resistance genes (ARGs) contribute to increased acquisition of resistance by pathogens in aquatic environments are challenges of profound significance. We explored the co-occurrence and removal versus enrichment of ARGs and human bacterial pathogens (HBPs) in municipal sewage sludge digesters. We combined metagenomic detection of a wide spectrum of 323 ARGs and 83 HBPs with a correlation-based statistical approach and charted a network of their co-occurrence relationships. The results indicate that most ARGs and a minor proportion of HBPs (mainly Collinsella aerofaciens, Streptococcus salivarius and Gordonia bronchialis) could not be removed by anaerobic digestion, revealing a biological risk of post-digestion sludge in disseminating antibiotic resistance and pathogenicity. Moreover, preferential co-occurrence patterns were evident within one ARG type (e.g., multidrug, beta-lactam, and aminoglycoside) and between two different ARG types (i.e., aminoglycoside and beta-lactam), possibly implicating co-effects of antibiotic selection pressure and co-resistance on shaping antibiotic resistome in sewage sludge. Unlike beta-lactam resistance genes, ARGs of multidrug and macrolide-lincosamide-streptogramin tended to co-occur more with HBPs. Strikingly, we presented evidence that the most straightforward biological origin of an ARG-species co-occurring event is a hosting relationship. Furthermore, a significant and robust HBP-species co-occurrence correlation provides a proper scenario for nominating HBP indicators (e.g., Bifidobacterium spp. are perfect indicators of C. aerofaciens; r = 0.92-0.99 and P-values < 0.01). Combined, this study demonstrates a creative and effective network-based metagenomic approach for exploring ARG hosts and HBP indicators and assessing ARGs acquisition by HBPs in human-impacted environments where ARGs and HBPs may co-thrive.

  3. Poly-ß-hydroxybutyrate content and dose of the bacterial carrier for Artemia enrichment determine the performance of giant freshwater prawn larvae.

    PubMed

    Thai, Truong Quoc; Wille, Mathieu; Garcia-Gonzalez, Linsey; Sorgeloos, Patrick; Bossier, Peter; De Schryver, Peter

    2014-06-01

    The beneficial effects of poly-β-hydroxybutyrate (PHB) for aquaculture animals have been shown in several studies. The strategy of applying PHB contained in a bacterial carrier has, however, hardly been considered. The effect of administering PHB-accumulated Alcaligenes eutrophus H16 containing 10 or 80 % PHB on dry weight, named A10 and A80, respectively, through the live feed Artemia was investigated on the culture performance of larvae of the giant freshwater prawn (Macrobrachium rosenbergii). Feeding larvae with Artemia nauplii enriched in a medium containing 100 and 1,000 mg L(-1) A80 significantly increased the survival with about 15 % and the development of the larvae with a larval stage index of about 1 as compared to feeding non-enriched Artemia. The survival of the larvae also significantly increased with about 35 % in case of a challenge with Vibrio harveyi. The efficiency of these treatments was equal to a control treatment of Artemia enriched in an 800 mg L(-1) PHB powder suspension, while Artemia enriched in 10 mg L(-1) A80, 100 mg L(-1) A10, and 1,000 mg L(-1) A10 did not bring similar effects. From our results, it can be concluded that PHB supplemented in a bacterial carrier (i.e., amorphous PHB) can increase the larviculture efficiency of giant freshwater prawn similar to supplementation of PHB in powdered form (i.e., crystalline PHB). When the level of PHB in the bacterial carrier is high, similar beneficial effects can be achieved as crystalline PHB, but at a lower live food enrichment concentration expressed on PHB basis.

  4. Environmental enrichment reduces the response to stress of the cholinergic system in the prefrontal cortex during aging.

    PubMed

    Segovia, Gregorio; Del Arco, Alberto; Garrido, Pedro; de Blas, Marta; Mora, Francisco

    2008-05-01

    The present study was designed to evaluate the release of acetylcholine in the prefrontal cortex (PFC) induced by handling stress during aging and also to investigate whether this response changed as a result of the animals living in an enriched environment. Male Wistar rats of 3 months of age were housed in control and enriched conditions during the entire period of their adult life and experiments were performed at 6, 15 and 24 months of age. Spontaneous motor activity was first monitored in an open field arena. Then, rats were stereotaxically implanted with guide cannula to perform microdialysis experiments in the PFC and to evaluate the effects of stress on extracellular concentrations of acetylcholine. Handling stress increased the extracellular concentrations of acetylcholine in the PFC of control and enriched rats. These increases were not modified by aging in control rats. However, environmental enrichment (EE) reduced the effects of stress on acetylcholine concentrations in all groups of age. Spontaneous motor activity in the open field was reduced by aging. EE also decreased motor activity in all groups of age. These results suggest that EE reduces the reactivity to stress of the cholinergic system in the prefrontal cortex during aging.

  5. The intestinal bacterial community in the food waste-reducing larvae of Hermetia illucens.

    PubMed

    Jeon, Hyunbum; Park, Soyoung; Choi, Jiyoung; Jeong, Gilsang; Lee, Sang-Beom; Choi, Youngcheol; Lee, Sung-Jae

    2011-05-01

    As it is known that food waste can be reduced by the larvae of Hermetia illucens (Black soldier fly, BSF), the scientific and commercial value of BSF larvae has increased recently. We hypothesised that the ability of catabolic degradation by BSF larvae might be due to intestinal microorganisms. Herein, we analysed the bacterial communities in the gut of BSF larvae by pyrosequencing of extracting intestinal metagenomic DNA from larvae that had been fed three different diets. The 16S rRNA sequencing results produced 9737, 9723 and 5985 PCR products from larval samples fed food waste, cooked rice and calf forage, respectively. A BLAST search using the EzTaxon program showed that the bacterial community in the gut of larvae fed three different diets was mainly composed of the four phyla with dissimilar proportions. Although the composition of the bacterial communities depended on the different nutrient sources, the identified bacterial strains in the gut of BSF larvae represented unique bacterial species that were unlike the intestinal microflora of other insects. Thus, our study analysed the structure of the bacterial communities in the gut of BSF larvae after three different feedings and assessed the application of particular bacteria for the efficient degradation of organic compounds.

  6. Anaerobic degradation of propane and butane by sulfate-reducing bacteria enriched from marine hydrocarbon cold seeps

    PubMed Central

    Jaekel, Ulrike; Musat, Niculina; Adam, Birgit; Kuypers, Marcel; Grundmann, Olav; Musat, Florin

    2013-01-01

    The short-chain, non-methane hydrocarbons propane and butane can contribute significantly to the carbon and sulfur cycles in marine environments affected by oil or natural gas seepage. In the present study, we enriched and identified novel propane and butane-degrading sulfate reducers from marine oil and gas cold seeps in the Gulf of Mexico and Hydrate Ridge. The enrichment cultures obtained were able to degrade simultaneously propane and butane, but not other gaseous alkanes. They were cold-adapted, showing highest sulfate-reduction rates between 16 and 20 °C. Analysis of 16S rRNA gene libraries, followed by whole-cell hybridizations with sequence-specific oligonucleotide probes showed that each enrichment culture was dominated by a unique phylotype affiliated with the Desulfosarcina-Desulfococcus cluster within the Deltaproteobacteria. These phylotypes formed a distinct phylogenetic cluster of propane and butane degraders, including sequences from environments associated with hydrocarbon seeps. Incubations with 13C-labeled substrates, hybridizations with sequence-specific probes and nanoSIMS analyses showed that cells of the dominant phylotypes were the first to become enriched in 13C, demonstrating that they were directly involved in hydrocarbon degradation. Furthermore, using the nanoSIMS data, carbon assimilation rates were calculated for the dominant cells in each enrichment culture. PMID:23254512

  7. Anaerobic degradation of propane and butane by sulfate-reducing bacteria enriched from marine hydrocarbon cold seeps.

    PubMed

    Jaekel, Ulrike; Musat, Niculina; Adam, Birgit; Kuypers, Marcel; Grundmann, Olav; Musat, Florin

    2013-05-01

    The short-chain, non-methane hydrocarbons propane and butane can contribute significantly to the carbon and sulfur cycles in marine environments affected by oil or natural gas seepage. In the present study, we enriched and identified novel propane and butane-degrading sulfate reducers from marine oil and gas cold seeps in the Gulf of Mexico and Hydrate Ridge. The enrichment cultures obtained were able to degrade simultaneously propane and butane, but not other gaseous alkanes. They were cold-adapted, showing highest sulfate-reduction rates between 16 and 20 °C. Analysis of 16S rRNA gene libraries, followed by whole-cell hybridizations with sequence-specific oligonucleotide probes showed that each enrichment culture was dominated by a unique phylotype affiliated with the Desulfosarcina-Desulfococcus cluster within the Deltaproteobacteria. These phylotypes formed a distinct phylogenetic cluster of propane and butane degraders, including sequences from environments associated with hydrocarbon seeps. Incubations with (13)C-labeled substrates, hybridizations with sequence-specific probes and nanoSIMS analyses showed that cells of the dominant phylotypes were the first to become enriched in (13)C, demonstrating that they were directly involved in hydrocarbon degradation. Furthermore, using the nanoSIMS data, carbon assimilation rates were calculated for the dominant cells in each enrichment culture.

  8. Mosquito control and bacterial flora in water enriched with organic matter and treated with Bacillus thuringiensis subsp. israelensis and Bacillus sphaericus formulations.

    PubMed

    Nguyen, T T; Su, T; Mulla, M S

    1999-12-01

    Three tests were conducted during July 17 to October 30, 1998 to study the impact of two mosquitocidal microbial agents on mosquito larvae and their contribution to bacterial flora in aquatic microcosms. Formulations of Bacillus thuringiensis subsp. israelensis (Bti) and Bacillus sphaericus strain 2362 (Bsph) were applied at various rates to outdoor tubs enriched with rabbit pellets and filled with irrigation water from a reservoir. Mosquito larvae were effectively controlled by all treatments; the magnitude of initial and persistent control depended on materials and dosages applied. Bacterial flora were assessed in the irrigation water as well as water in the enriched tubs before and after treatment with the microbial agents. The irrigation water contained 800-1000 total bacterial cells/ml. The populations of total bacteria and spore formers peaked on day 3 after enriching and filling the tubs, then declined progressively to the low levels at the end of the tests. After treatment, the numbers of Bti and Bsph spores in treated tubs prevailed at a dosage-dependent manner, their populations peaked at three hours after treatment, and declined progressively thereafter. The contribution of Bti and Bsph spores to the total bacterial flora was negligible but significant to the counts of spore-forming bacteria. The gram-negative bacteria made up more than 80% of the total bacterial flora during the test periods; and, of these, gram-negative rods constituted the greatest proportion, gradually increasing from the time of flooding to the end of the tests. Gram-negative cocci also occurred in relatively great proportion, but showed a reverse trend as compared with the gram-negative rods, declining gradually from pretreatment to the end of the tests. Gram-positive rods (spore formers), including Bti and Bsph, occurred in low numbers in all the tests but increased slightly in treated tubs due to the addition of Bti and Bsph spores. Gram-positive cocci occurred occasionally in

  9. Acidification of formula reduces bacterial translocation and gut colonization in a neonatal rabbit model.

    PubMed

    Mehall, J R; Northrop, R; Saltzman, D A; Jackson, R J; Smith, S D

    2001-01-01

    The authors hypothesized that gastric acidity is protective because it is bactericidal. They tested acidified formula for protection against gut colonization and bacterial translocation. In vitro: Formula was acidified to pH of 2, 3, 4, 5 and innoculated with Enterobacter. Growth over time was quantitatively assessed. In vivo: 442 premature rabbit pups were sorted randomly and fed formula of pH 2, 3, 4, or 7, with ranitidine. Two models were utilized: (1) with bacterial challenge using a known acid sensitive organism, (2) without bacterial challenge to simulate natural gut colonization and to test against organisms of unknown acid sensitivity. Normal acid animals received pH 7 formula, no ranitidine. On day 3, the mesenteric lymph nodes (MLN), spleen, liver, and cecum were harvested and cultured. Bacterial growth was inhibited at pH 2 and 3, growth was logarithmic above pH 4 (P<.001). Total and organ-specific translocation was reduced at pH 3 and below in both models (P<.05). Translocation with formula pH 3 equaled normal acid animals. Quantitative cecal colonization was reduced in pups receiving pH 3 and below in both models (P<.05). Acidification of formula below pH 4 is bactericidal to enteric organisms. Acidified formula decreases bacterial translocation and gut colonization.

  10. Proceedings of the 1994 international meeting on reduced enrichment for research and test reactors

    SciTech Connect

    1997-08-01

    This meeting brought together participants in the international effort to minimize and eventually eliminate the use of highly enriched uranium in civilian nuclear programs. Papers cover the following topics: National programs; fuel cycle; nuclear fuels; analyses; advanced reactors; and reactor conversions. Selected papers have been indexed separately for inclusion to the Energy Science and Technology Database.

  11. Nutrient enrichment reduces constraints on material flows in a detritus-based food web

    Treesearch

    Wyatt F. Cross; Bruce Wallace; Amy D. Rosemond

    2007-01-01

    Most aquatic and terrestrial ecosystems are experiencing increased nutrient availability, which is affecting their structure and function. By altering community composition and productivity of consumers, enrichment can indirectly cause changes in the pathways and magnitude of material flows in food webs. These changes, in turn, have major consequences for material...

  12. Factor XI-deficient mice display reduced inflammation, coagulopathy, and bacterial growth during listeriosis.

    PubMed

    Luo, Deyan; Szaba, Frank M; Kummer, Lawrence W; Johnson, Lawrence L; Tucker, Erik I; Gruber, Andras; Gailani, David; Smiley, Stephen T

    2012-01-01

    In mice infected sublethally with Listeria monocytogenes, fibrin is deposited at low levels within hepatic tissue, where it functions protectively by limiting bacterial growth and suppressing hemorrhagic pathology. Here we demonstrate that mice infected with lethal doses of L. monocytogenes produce higher levels of fibrin and display evidence of systemic coagulopathy (i.e., thrombocytopenia, fibrinogen depletion, and elevated levels of thrombin-antithrombin complexes). When the hepatic bacterial burden exceeds 1×10(6) CFU, levels of hepatic fibrin correlate with the bacterial burden, which also correlates with levels of hepatic mRNA encoding the hemostatic enzyme factor XI (FXI). Gene-targeted FXI-deficient mice show significantly improved survival upon challenge with high doses of L. monocytogenes and also display reduced levels of hepatic fibrin, decreased evidence of coagulopathy, and diminished cytokine production (interleukin-6 [IL-6] and IL-10). While fibrin limits the bacterial burden during sublethal listeriosis in wild-type mice, FXI-deficient mice display a significantly improved capacity to restrain the bacterial burden during lethal listeriosis despite their reduced fibrin levels. They also show less evidence of hepatic necrosis. In conjunction with suboptimal antibiotic therapy, FXI-specific monoclonal antibody 14E11 improves survival when administered therapeutically to wild-type mice challenged with high doses of L. monocytogenes. Together, these findings demonstrate the utility of murine listeriosis as a model for dissecting qualitative differences between protective and pathological host responses and reveal novel roles for FXI in exacerbating inflammation and pathogen burden during a lethal bacterial infection.

  13. Toward the physical basis of thermophilic proteins: linking of enriched polar interactions and reduced heat capacity of unfolding.

    PubMed

    Zhou, Huan-Xiang

    2002-12-01

    The enrichment of salt bridges and hydrogen bonding in thermophilic proteins has long been recognized. Another tendency, featuring lower heat capacity of unfolding (DeltaC(p)) than found in mesophilic proteins, is emerging from the recent literature. Here we present a simple electrostatic model to illustrate that formation of a salt-bridge or hydrogen-bonding network around an ionized group in the folded state leads to increased folding stability and decreased DeltaC(p). We thus suggest that the reduced DeltaC(p) of thermophilic proteins could partly be attributed to enriched polar interactions. A reduced DeltaC(p) might serve as an indicator for the contribution of polar interactions to folding stability.

  14. Fuel development activities of the US RERTR Program. [Reduced Enrichment Research and Test Reactor

    SciTech Connect

    Snelgrove, J.L.; Domagala, R.F.; Wiencek, T.C.; Copeland, G.L.

    1983-01-01

    Progress in the development and irradiation testing of high-density fuels for use with low-enriched uranium in research and test reactors is reported. Swelling and blister-threshold temperature data obtained from the examination of miniature fuel plates containing UAl/sub x/, U/sub 3/O/sub 8/, U/sub 3/Si/sub 2/, or U/sub 3/Si dispersed in an aluminum matrix are presented. Combined with the results of metallurgical examinations, these data show that these four fuel types will perform adequately to full burnup of the /sup 235/U contained in the low-enriched fuel. The exothermic reaction of the uranium-silicide fuels with aluminum has been found to occur at about the same temperature as the melting of the aluminum matrix and cladding and to be essentially quenched by the melting endotherm. A new series of miniature fuel plate irradiations is also discussed.

  15. Bacterial Community Profiling of H2/CO2 or Formate-Utilizing Acetogens Enriched from Diverse Ecosystems

    NASA Astrophysics Data System (ADS)

    Han, R.; Zhang, L.; Fu, B.; Liu, H.

    2014-12-01

    Synthetic gases are usually generated from either cellulosic agricultural waste combustion or industrial release and could be subsequently transformed into acetate, ethanol, and/or butyrate by homoacetogenic bacteria, which commonly possess reductive acetyl-CoA synthesis pathway. Homoacetogen-based syngas fermentation technology provides an alternative solution to link greenhouse gas emission control and cellulosic solid waste treatment with biofuels production. The objective of our current project is to hunt for homoacetogens with capabilities of highly efficiently converting syngases to chemical solvents. In this study, we evaluated homoacetogens population dynamics during enrichments and pinpointed dominant homoacetogens representing diverse ecosystems enriched by different substrates. We enriched homoacetogens from four different samples including waste activate sludge, freshwater sediment, anaerobic methanogenic sludge, and cow manure using H2/CO2 (4:1) or formate as substrate for homoacetogen enrichment. Along with the formyltetrahydrofolate synthetase (FTHFS) gene (fhs gene)-specific real time qPCR assay and Terminal Restriction Fragment Length Polymorphism (T-RFLP) analysis, 16S rRNA based 454 high-throughput pyrosequencing was applied to reveal the population dynamic and community structure during enrichment from different origins. Enrichment of homoacetogenic populations coincided with accumulations of short chain fatty acids such as acetate and butyrate. 454 high-throughput pyrosequencing revealed Firmicutes and Spirochaetes populations became dominant while the overall microbial diversity decreased after enrichment. The most abundant sequences among the four origins belonged to the following phyla: Firmicutes, Spirochaetes, Proteobacteria, and Bacteroidetes, accounting for 62.1%-99.1% of the total reads. The major putative homoacetogenic species enriched on H2/CO2 or formate belonged to Clostridium spp., Acetobacterium spp., Acetoanaerobium spp

  16. Protective effects of hydrogen enriched saline on liver ischemia reperfusion injury by reducing oxidative stress and HMGB1 release

    PubMed Central

    2014-01-01

    Background The nuclear protein high-mobility group box 1 (HMGB1) is a key trigger for the inflammatory reaction during liver ischemia reperfusion injury (IRI). Hydrogen treatment was recently associated with down-regulation of the expression of HMGB1 and pro-inflammatory cytokines during sepsis and myocardial IRI, but it is not known whether hydrogen has an effect on HMGB1 in liver IRI. Methods A rat model of 60 minutes 70% partial liver ischemia reperfusion injury was used. Hydrogen enriched saline (2.5, 5 or 10 ml/kg) was injected intraperitoneally 10 minutes before hepatic reperfusion. Liver injury was assessed by serum alanine aminotransferase (ALT) enzyme levels and histological changes. We also measured malondialdehyde (MDA), hydroxynonenal (HNE) and 8-hydroxy-guanosine (8-OH-G) levels as markers of the peroxidation injury induced by reactive oxygen species (ROS). In addition, pro-inflammatory cytokines including TNF-α and IL-6, and high mobility group box B1 protein (HMGB1) were measured as markers of post ischemia-reperfusion inflammation. Results Hydrogen enriched saline treatment significantly attenuated the severity of liver injury induced by ischemia-reperfusion. The treatment group showed reduced serum ALT activity and markers of lipid peroxidation and post ischemia reperfusion histological changes were reduced. Hydrogen enriched saline treatment inhibited HMGB1 expression and release, reflecting a reduced local and systemic inflammatory response to hepatic ischemia reperfusion. Conclusion These results suggest that, in our model, hydrogen enriched saline treatment is protective against liver ischemia-reperfusion injury. This effect may be mediated by both the anti-oxidative and anti-inflammatory effects of the solution. PMID:24410860

  17. How Fitness Reduced, Antimicrobial Resistant Bacteria Survive and Spread: A Multiple Pig - Multiple Bacterial Strain Model

    PubMed Central

    Græsbøll, Kaare; Nielsen, Søren Saxmose; Toft, Nils; Christiansen, Lasse Engbo

    2014-01-01

    More than 30% of E. coli strains sampled from pig farms in Denmark over the last five years were resistant to the commonly used antimicrobial tetracycline. This raises a number of questions: How is this high level sustained if resistant bacteria have reduced growth rates? Given that there are multiple susceptible and resistant bacterial strains in the pig intestines, how can we describe their coexistence? To what extent does the composition of these multiple strains in individual pigs influence the total bacterial population of the pig pen? What happens to a complex population when antimicrobials are used? To investigate these questions, we created a model where multiple strains of bacteria coexist in the intestines of pigs sharing a pen, and explored the parameter limits of a stable system; both with and without an antimicrobial treatment. The approach taken is a deterministic bacterial population model with stochastic elements of bacterial distributions and transmission. The rates that govern the model are process-oriented to represent growth, excretion, and uptake from environment, independent of herd and meta-population structures. Furthermore, an entry barrier and elimination process for the individual strains in each pig were implemented. We demonstrate how competitive growth between multiple bacterial strains in individual pigs, and the transmission between pigs in a pen allow for strains of antimicrobial resistant bacteria to persist in a pig population to different extents, and how quickly they can become dominant if antimicrobial treatment is initiated. The level of spread depends in a non-linear way of the parameters that govern excretion and uptake. Furthermore, the sampling of initial distributions of strains and stochastic transmission events give rise to large variation in how homogenous and how resistant the bacterial population becomes. Most important: resistant bacteria are demonstrated to survive with a disadvantage in growth rate of well over 10

  18. Glycyrrhizin Reduces HMGB1 and Bacterial Load in Pseudomonas aeruginosa Keratitis

    PubMed Central

    Ekanayaka, Sandamali A.; McClellan, Sharon A.; Barrett, Ronald P.; Kharotia, Shikhil; Hazlett, Linda D.

    2016-01-01

    Purpose High mobility group box 1 (HMGB1) contributes to poor disease outcome in Pseudomonas aeruginosa keratitis. This study tests the prophylactic effect of treatment with HMGB1 inhibitors, glycyrrhizin (GLY) and its derivative, carbenoxolone (CBX), for Pseudomonas keratitis. Methods We treated C57BL/6 (B6) mice subconjunctivally with GLY or CBX, infected with a noncytotoxic clinical isolate (KEI 1025) or a cytotoxic strain (ATCC 19660) of P. aeruginosa, and injected intraperitoneally with either agent. Clinical score, photography with a slit lamp, real-time RT-PCR, ELISA, myeloperoxidase (MPO) assay, bacterial plate count, histopathology, and absorbance assays were used to assess treatment efficacy and bacteriostatic activity. Results After KEI 1025 infection, GLY treatment reduced HMGB1 (mRNA and protein levels) and improved disease outcome with significant reduction in mRNA levels of IL-1β, TLR4, CXCL2, and IL-12; protein expression (IL-1β, CXCL2); neutrophil infiltrate; and bacterial load. Treatment with GLY enhanced antimicrobial proteins, including CRAMP and mBD2, but not mBD3. Glycyrrhizin also reduced clinical scores and improved disease outcome in corneas infected with strain 19660. However, neither HMGB1 mRNA or protein levels were reduced, but rather, CXCL2 expression (mRNA and protein), neutrophil infiltrate, and bacterial load were reduced statistically. Treatment with GLY initiated 6 hours after infection reduced plate count; GLY also was bacteriostatic for KEI 1025 and ATCC 19660. Conclusions Glycyrrhizin reduces HMGB1 and is protective against P. aeruginosa–induced keratitis with a clinical isolate that is noncytotoxic. It was similar, but less effective when used after infection with a cytotoxic strain, which did not reduce HMGB1. PMID:27792814

  19. Reduced Airway Surface pH Impairs Bacterial Killing in the Porcine Cystic Fibrosis Lung

    PubMed Central

    Pezzulo, Alejandro A.; Tang, Xiao Xiao; Hoegger, Mark J.; Abou Alaiwa, Mahmoud H.; Ramachandran, Shyam; Moninger, Thomas O.; Karp, Phillip H.; Wohlford-Lenane, Christine L.; Haagsman, Henk P.; van Eijk, Martin; Bánfi, Botond; Horswill, Alexander R.; Stoltz, David A.; McCray, Paul B.; Welsh, Michael J.; Zabner, Joseph

    2012-01-01

    Cystic fibrosis (CF) is a life-shortening disease caused by mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) gene 1. Although bacterial lung infection and the resulting inflammation cause most of the morbidity and mortality, how loss of CFTR first disrupts airway host defense has remained uncertain 2–6. We asked what abnormalities impair eradication when a bacterium lands on the pristine surface of a newborn CF airway? To investigate these defects, we interrogated the viability of individual bacteria immobilized on solid grids and placed on the airway surface. As a model we studied CF pigs, which spontaneously develop hallmark features of CF lung disease 7,8. At birth, their lungs lack infection and inflammation, but have a reduced ability to eradicate bacteria 8. Here we show that in newborn wild-type pigs, the thin layer of airway surface liquid (ASL) rapidly killed bacteria in vivo, when removed from the lung, and in primary epithelial cultures. Lack of CFTR reduced bacterial killing. We found that ASL pH was more acidic in CF, and reducing pH inhibited the antimicrobial activity of ASL. Reducing ASL pH diminished bacterial killing in wild-type pigs, and increasing ASL pH rescued killing in CF pigs. These results directly link the initial host defense defect to loss of CFTR, an anion channel that facilitates HCO3− transport 9–13. Without CFTR, airway epithelial HCO3− secretion is defective, ASL pH falls and inhibits antimicrobial function, and thereby impairs killing of bacteria that enter the newborn lung. These findings suggest that increasing ASL pH might prevent the initial infection in patients with CF and that assaying bacterial killing could report on the benefit of therapeutic interventions. PMID:22763554

  20. Evaluation of free-stall mattress bedding treatments to reduce mastitis bacterial growth

    SciTech Connect

    Kristula, M.A.; Dou, Z.; Toth, J.D.; Smith, B.I.; Harvey, N.; Sabo, M.

    2008-05-15

    Bacterial counts were compared in free-stall mattresses and teat ends exposed to 5 treatments in a factorial study design on 1 dairy farm. Mattresses in five 30-cow groups were subjected to 1 of 5 bedding treatments every other day: 0.5 kg of hydrated limestone, 120 mL of commercial acidic conditioner, 1 kg of coal fly ash, 1 kg of kiln-dried wood shavings, and control (no bedding). Counts of coliforms, Klebsiella spp., Escherichia coli, and Streptococcus spp. were lowest on mattresses bedded with lime. Mattresses bedded with the commercial acidic conditioner had the next lowest counts for coliforms, Klebsiella spp., and Streptococcus spp. Wood shavings and the no-bedding control had the highest counts for coliform and Klebsiella spp. Compared with wood shavings or control, fly ash reduced the counts of coliforms, whereas for the other 3 bacterial groups, the reduction was not always significant. Streptococcus spp. counts were greatest in the control group and did not differ among the shavings and fly ash groups. Teat swab results indicated that hydrated lime was the only bedding treatment that significantly decreased the counts of both coliforms and Klebsiella spp. There were no differences in Streptococcus spp. numbers on the teats between any of the bedding treatments. Bacterial populations grew steadily on mattresses and were generally higher at 36 to 48 h than at 12 to 24 h, whereas bacterial populations on teats grew rapidly by 12 h and then remained constant. Hydrated lime was the only treatment that significantly reduced bacterial counts on both mattresses and teat ends, but it caused some skin irritation.

  1. Bacteria killing nanotechnology Bio-Kil effectively reduces bacterial burden in intensive care units.

    PubMed

    Hsueh, P-R; Huang, H-C; Young, T-G; Su, C-Y; Liu, C-S; Yen, M-Y

    2014-04-01

    A contaminated hospital environment has been identified as an important reservoir of pathogens causing healthcare-associated infections. This study is to evaluate the efficacy of bacteria killing nanotechnology Bio-Kil on reducing bacterial counts in an intensive care unit (ICU). Two single-bed rooms (S-19 and S-20) in the ICU were selected from 7 April to 27 May 2011. Ten sets of new textiles (pillow cases, bed sheets, duvet cover, and patient clothing) used by patients in the two single-bed rooms were provided by the sponsors. In the room S-20, the 10 sets of new textiles were washed with Bio-Kil; the room walls, ceiling, and air-conditioning filters were treated with Bio-Kil; and the surfaces of instruments (respirator, telephone, and computer) were covered with Bio-Kil-embedded silicon pads. Room S-19 served as the control. We compared the bacterial count on textiles and environment surfaces as well as air samples between the two rooms. A total of 1,364 samples from 22 different sites in each room were collected. The mean bacterial count on textiles and environmental surfaces in room S-20 was significantly lower than that in room S-19 (10.4 vs 49.6 colony-forming units [CFU]/100 cm(2); P < 0.001). Room S-20 had lower bacterial counts in air samples than room S-19 (33.4-37.6 vs 21.6-25.7 CFU/hour/plate; P < 0.001). The density of microbial isolations was significantly greater among patients admitted to room S-19 than those to room S-20 (9.15 vs 5.88 isolates per 100 patient-days, P < 0.05). Bio-Kil can significantly reduce bacterial burden in the environment of the ICU.

  2. Evaluation of free-stall mattress bedding treatments to reduce mastitis bacterial growth.

    PubMed

    Kristula, M A; Dou, Z; Toth, J D; Smith, B I; Harvey, N; Sabo, M

    2008-05-01

    Bacterial counts were compared in free-stall mattresses and teat ends exposed to 5 treatments in a factorial study design on 1 dairy farm. Mattresses in five 30-cow groups were subjected to 1 of 5 bedding treatments every other day: 0.5 kg of hydrated limestone, 120 mL of commercial acidic conditioner, 1 kg of coal fly ash, 1 kg of kiln-dried wood shavings, and control (no bedding). Counts of coliforms, Klebsiella spp., Escherichia coli, and Streptococcus spp. were lowest on mattresses bedded with lime. Mattresses bedded with the commercial acidic conditioner had the next lowest counts for coliforms, Klebsiella spp., and Streptococcus spp. Wood shavings and the no-bedding control had the highest counts for coliform and Klebsiella spp. Compared with wood shavings or control, fly ash reduced the counts of coliforms, whereas for the other 3 bacterial groups, the reduction was not always significant. Streptococcus spp. counts were greatest in the control group and did not differ among the shavings and fly ash groups. Teat swab results indicated that hydrated lime was the only bedding treatment that significantly decreased the counts of both coliforms and Klebsiella spp. There were no differences in Streptococcus spp. numbers on the teats between any of the bedding treatments. Bacterial populations grew steadily on mattresses and were generally higher at 36 to 48 h than at 12 to 24 h, whereas bacterial populations on teats grew rapidly by 12 h and then remained constant. Hydrated lime was the only treatment that significantly reduced bacterial counts on both mattresses and teat ends, but it caused some skin irritation.

  3. Cardamonin reduces chemotherapy-enriched breast cancer stem-like cells in vitro and in vivo.

    PubMed

    Jia, Deyong; Tan, Yuan; Liu, Huijuan; Ooi, Sarah; Li, Li; Wright, Kathryn; Bennett, Steffany; Addison, Christina L; Wang, Lisheng

    2016-01-05

    The failure of cytotoxic chemotherapy in breast cancers has been closely associated with the presence of drug resistant cancer stem cells (CSCs). Thus, screening for small molecules that selectively inhibit growth of CSCs may offer great promise for cancer control, particularly in combination with chemotherapy. In this report, we provide the first demonstration that cardamonin, a small molecule, selectively inhibits breast CSCs that have been enriched by chemotherapeutic drugs. In addition, cardamonin also sufficiently prevents the enrichment of CSCs when simultaneously used with chemotherapeutic drugs. Specifically, cardamonin effectively abolishes chemotherapeutic drug-induced up-regulation of IL-6, IL-8 and MCP-1 and activation of NF-κB/IKBα and Stat3. Furthermore, in a xenograft mouse model, co-administration of cardamonin and the chemotherapeutic drug doxorubicin significantly retards tumor growth and simultaneously decreases CSC pools in vivo. Since cardamonin has been found in some herbs, this work suggests a potential new approach for the effective treatment of breast CSCs by administration of cardamonin either concurrent with or after chemotherapeutic drugs.

  4. Method and apparatus for reducing cold-phase emissions by utilizing oxygen-enriched intake air

    DOEpatents

    Poola, Ramesh B.; Sekar, Ramanujam R.; Stork, Kevin C.

    1997-01-01

    An oxygen-enriched air intake control system for an internal combustion engine includes air directing apparatus to control the air flow into the intake of the engine. During normal operation of the engine, ambient air flowing from an air filter of the engine flows through the air directing apparatus into the intake of the engine. In order to decrease the amount of carbon monoxide (CO) and hydrocarbon (HC) emissions that tend to be produced by the engine during a short period of time after the engine is started, the air directing apparatus diverts for a short period of time following the start up of the engine at least a portion of the ambient air from the air filter through a secondary path. The secondary path includes a selectively permeable membrane through which the diverted portion of the ambient air flows. The selectively permeable membrane separates nitrogen and oxygen from the diverted air so that oxygen enriched air containing from about 23% to 25% oxygen by volume is supplied to the intake of the engine.

  5. Metagenomic Analyses of the Autotrophic Fe(II)-Oxidizing, Nitrate-Reducing Enrichment Culture KS

    PubMed Central

    Tominski, Claudia; Kappler, Andreas; Behrens, Sebastian

    2016-01-01

    Nitrate-dependent ferrous iron [Fe(II)] oxidation (NDFO) is a well-recognized chemolithotrophic pathway in anoxic sediments. The neutrophilic chemolithoautotrophic enrichment culture KS originally obtained from a freshwater sediment (K. L. Straub, M. Benz, B. Schink, and F. Widdel, Appl Environ Microbiol 62:1458–1460, 1996) has been used as a model system to study NDFO. However, the primary Fe(II) oxidizer in this culture has not been isolated, despite extensive efforts to do so. Here, we present a metagenomic analysis of this enrichment culture in order to gain insight into electron transfer pathways and the roles of different bacteria in the culture. We obtained a near-complete genome of the primary Fe(II) oxidizer, a species in the family Gallionellaceae, and draft genomes from its flanking community members. A search of the putative extracellular electron transfer pathways in these genomes led to the identification of a homolog of the MtoAB complex [a porin-multiheme cytochrome c system identified in neutrophilic microaerobic Fe(II)-oxidizing Sideroxydans lithotrophicus ES-1] in a Gallionellaceae sp., and findings of other putative genes involving cytochrome c and multicopper oxidases, such as Cyc2 and OmpB. Genome-enabled metabolic reconstruction revealed that this Gallionellaceae sp. lacks nitric oxide and nitrous oxide reductase genes and may partner with flanking populations capable of complete denitrification to avoid toxic metabolite accumulation, which may explain its resistance to growth in pure culture. This and other revealed interspecies interactions and metabolic interdependencies in nitrogen and carbon metabolisms may allow these organisms to cooperate effectively to achieve robust chemolithoautotrophic NDFO. Overall, the results significantly expand our knowledge of NDFO and suggest a range of genetic targets for further exploration. PMID:26896135

  6. Growth hormone reduces bacterial translocation in radiation enteritis in the rat.

    PubMed

    Prieto, I; Gómez de Segura, I A; García Grande, A; Guerra, A; Pozo, F; García, P; de Miguel, E

    1998-05-01

    Radiotherapy may be considered as one of the most effective treatments for digestive tumours. This procedure has major side effects, especially in fast growing tissues like intestinal mucosa. The administration of drugs that reduce or avoid radiation injury of the intestinal mucosa may be clinically advantageous. Growth hormone is a peptide suitable for this purpose by modifying cell proliferation within the intestinal crypt. Adult male Wistar rats were used in a model of abdominal irradiation. Each irradiated animal received 1200 cGy under anaesthesia and was sacrificed four and seven days later. The animals were treated with either saline or growth hormone (1 mg/kg/day) beginning immediately after the irradiation treatment. On the day of sacrifice, intestinal samples were taken for morphometric measurements and mesenteric lymph nodes for bacterial translocation. Mortality was of 50% approximately and was not affected by growth hormone treatment in irradiated animals. Bacterial translocation increased (p < 0.05) in irradiated animals whereas no significant increase was observed in rats treated with growth hormone. Growth hormone promotes an earlier growth of intestinal villi in irradiated animals (p < 0.05). Growth hormone promotes the morphologic adaptation of intestinal mucosa after abdominal irradiation, reducing bacterial translocation in rat.

  7. Effect of Hydrogenase and Mixed Sulfate-Reducing Bacterial Populations on the Corrosion of Steel

    PubMed Central

    Bryant, Richard D.; Jansen, Wayne; Boivin, Joe; Laishley, Edward J.; Costerton, J. William

    1991-01-01

    The importance of hydrogenase activity to corrosion of steel was assessed by using mixed populations of sulfate-reducing bacteria isolated from corroded and noncorroded oil pipelines. Biofilms which developed on the steel studs contained detectable numbers of sulfate-reducing bacteria (104 increasing to 107/0.5 cm2). However, the biofilm with active hydrogenase activity (i.e., corrosion pipeline organisms), as measured by a semiquantitative commercial kit, was associated with a significantly higher corrosion rate (7.79 mm/year) relative to noncorrosive biofilm (0.48 mm/year) with 105 sulfate-reducing bacteria per 0.5 cm2 but no measurable hydrogenase activity. The importance of hydrogenase and the microbial sulfate-reducing bacterial population making up the biofilm are discussed relative to biocorrosion. Images PMID:16348560

  8. Structural and Functional Dynamics of Sulfate-Reducing Populations in Bacterial Biofilms

    PubMed Central

    Santegoeds, Cecilia M.; Ferdelman, Timothy G.; Muyzer, Gerard; de Beer, Dirk

    1998-01-01

    We describe the combined application of microsensors and molecular techniques to investigate the development of sulfate reduction and of sulfate-reducing bacterial populations in an aerobic bacterial biofilm. Microsensor measurements for oxygen showed that anaerobic zones developed in the biofilm within 1 week and that oxygen was depleted in the top 200 to 400 μm during all stages of biofilm development. Sulfate reduction was first detected after 6 weeks of growth, although favorable conditions for growth of sulfate-reducing bacteria (SRB) were present from the first week. In situ hybridization with a 16S rRNA probe for SRB revealed that sulfate reducers were present in high numbers (approximately 108 SRB/ml) in all stages of development, both in the oxic and anoxic zones of the biofilm. Denaturing gradient gel electrophoresis (DGGE) showed that the genetic diversity of the microbial community increased during the development of the biofilm. Hybridization analysis of the DGGE profiles with taxon-specific oligonucleotide probes showed that Desulfobulbus and Desulfovibrio were the main sulfate-reducing bacteria in all biofilm samples as well as in the bulk activated sludge. However, different Desulfobulbus and Desulfovibrio species were found in the 6th and 8th weeks of incubation, respectively, coinciding with the development of sulfate reduction. Our data indicate that not all SRB detected by molecular analysis were sulfidogenically active in the biofilm. PMID:9758792

  9. Periodic Presumptive Treatment for Vaginal Infections May Reduce the Incidence of Sexually Transmitted Bacterial Infections.

    PubMed

    Balkus, Jennifer E; Manhart, Lisa E; Lee, Jeannette; Anzala, Omu; Kimani, Joshua; Schwebke, Jane; Shafi, Juma; Rivers, Charles; Kabare, Emanuel; Scott McClelland, R

    2016-06-15

    Bacterial vaginosis (BV) may increase women's susceptibility to sexually transmitted infections (STIs). In a randomized trial of periodic presumptive treatment (PPT) to reduce vaginal infections, we observed a significant reduction in BV. We further assessed the intervention effect on incident Chlamydia trachomatis, Neisseria gonorrhoeae, and Mycoplasma genitalium infection. Nonpregnant, human immunodeficiency virus-uninfected women from the United States and Kenya received intravaginal metronidazole (750 mg) plus miconazole (200 mg) or placebo for 5 consecutive nights each month for 12 months. Genital fluid specimens were collected every other month. Poisson regression models were used to assess the intervention effect on STI acquisition. Of 234 women enrolled, 221 had specimens available for analysis. Incidence of any bacterial STI (C. trachomatis, N. gonorrhoeae, or M. genitalium infection) was lower in the intervention arm, compared with the placebo arm (incidence rate ratio [IRR], 0.54; 95% confidence interval [CI], .32-.91). When assessed individually, reductions in STI incidences were similar but not statistically significant (IRRs, 0.50 [95% confidence interval {CI}, .20-1.23] for C. trachomatis infection, 0.56 [95% CI, .19-1.67] for N. gonorrhoeae infection, and 0.66 [95% CI, .38-1.15] for M. genitalium infection). In addition to reducing BV, this PPT intervention may also reduce the risk of bacterial STI among women. Because BV is highly prevalent, often persists, and frequently recurs after treatment, interventions that reduce BV over extended periods could play a role in decreasing STI incidence globally. © The Author 2016. Published by Oxford University Press for the Infectious Diseases Society of America. All rights reserved. For permissions, e-mail journals.permissions@oup.com.

  10. Bacterial diversity in shallow oligotrophic marine benthos and overlying waters: effects of virus infection, containment, and nutrient enrichment.

    PubMed

    Hewson, I; Vargo, G A; Fuhrman, J A

    2003-10-01

    Little is known of the factors shaping sediment bacterial communities, despite their high abundance and reports of high diversity. Two factors hypothesized to shape bacterial communities in the water column are nutrient (resource) availability and virus infection. The role these factors play in benthic bacterial diversity was assessed in oligotrophic carbonate-based sediments of Florida Bay (USA). Sediment-water mesocosm enclosures were made from 1-m diameter clear polycarbonate cylinders which were pushed into sediments to approximately 201 cm sediment depth enclosing approximately 80 L of water. Mesocosms were amended each day for 14 d with 10 microM NH4+ and 1 microM PO4(3-). In a second experiment, viruses from a benthic flocculent layer were concentrated and added back to flocculent layer samples which were collected near the mesocosm enclosures. Photosynthesis by microalgae in virus-amended incubations was monitored by pulse-amplitude modulated (PAM) fluorescence. In both experiments, bacterial diversity was estimated using automated rRNA intergenic spacer analysis (ARISA), a high-resolution fingerprinting approach. Initial sediment bacterial operational taxonomic unit (OTU) richness (236 +/- 3) was higher than in the water column (148 +/- 9), where an OTU was detectable when its amplified DNA represented >0.09% of the total amplified DNA. Effects on bacterial diversity and operational taxonomic unit (OTU) richness in nutrient-amended mesocosms may have been masked by the effects of containment, which stimulated OTU richness in the water column, but depressed OTU richness and diversity in sediments. Nutrient addition significantly elevated virus abundance and the ratio of viruses to bacteria (p < 0.05 for both) in the sediments, concomitant with elevated bacterial diversity. However, water column bacterial diversity (in unamended controls) was not affected by nutrient amendments, which may be due to rapid nutrient uptake by sediment organisms or adsorption of

  11. Microbial Diversity in Sulfate-Reducing Marine Sediment Enrichment Cultures Associated with Anaerobic Biotransformation of Coastal Stockpiled Phosphogypsum (Sfax, Tunisia).

    PubMed

    Zouch, Hana; Karray, Fatma; Armougom, Fabrice; Chifflet, Sandrine; Hirschler-Réa, Agnès; Kharrat, Hanen; Kamoun, Lotfi; Ben Hania, Wajdi; Ollivier, Bernard; Sayadi, Sami; Quéméneur, Marianne

    2017-01-01

    Anaerobic biotechnology using sulfate-reducing bacteria (SRB) is a promising alternative for reducing long-term stockpiling of phosphogypsum (PG), an acidic (pH ~3) by-product of the phosphate fertilizer industries containing high amounts of sulfate. The main objective of this study was to evaluate, for the first time, the diversity and ability of anaerobic marine microorganisms to convert sulfate from PG into sulfide, in order to look for marine SRB of biotechnological interest. A series of sulfate-reducing enrichment cultures were performed using different electron donors (i.e., acetate, formate, or lactate) and sulfate sources (i.e., sodium sulfate or PG) as electron acceptors. Significant sulfide production was observed from enrichment cultures inoculated with marine sediments, collected near the effluent discharge point of a Tunisian fertilizer industry (Sfax, Tunisia). Sulfate sources impacted sulfide production rates from marine sediments as well as the diversity of SRB species belonging to Deltaproteobacteria. When PG was used as sulfate source, Desulfovibrio species dominated microbial communities of marine sediments, while Desulfobacter species were mainly detected using sodium sulfate. Sulfide production was also affected depending on the electron donor used, with the highest production obtained using formate. In contrast, low sulfide production (acetate-containing cultures) was associated with an increase in the population of Firmicutes. These results suggested that marine Desulfovibrio species, to be further isolated, are potential candidates for bioremediation of PG by immobilizing metals and metalloids thanks to sulfide production by these SRB.

  12. Influence of the cycle length on the production of PHA and polyglucose from glycerol by bacterial enrichments in sequencing batch reactors.

    PubMed

    Moralejo-Gárate, Helena; Palmeiro-Sánchez, Tania; Kleerebezem, Robbert; Mosquera-Corral, Anuska; Campos, José Luis; van Loosdrecht, Mark C M

    2013-12-01

    PHA, a naturally occurring biopolymer produced by a wide range of microorganisms, is known for its applications as bioplastic. In recent years the use of agro-industrial wastewater as substrate for PHA production by bacterial enrichments has attracted considerable research attention. Crude glycerol as generated during biodiesel production is a waste stream that due to its high organic matter content and low price could be an interesting substrate for PHA production. Previously we have demonstrated that when glycerol is used as substrate in a feast-famine regime, PHA and polyglucose are simultaneously produced as storage polymers. The work described in this paper aimed at understanding the effect of the cycle length on the bacterial enrichment process with emphasis on the distribution of glycerol towards PHA and polyglucose. Two sequencing batch reactors where operated with the same hydraulic and biomass retention time. A short cycle length (6 h) favored polyglucose production over PHA, whereas at long cycle length (24 h) PHA was more favored. In both communities the same microorganism appeared dominating, suggesting a metabolic rather than a microbial competition response. Moreover, the presence of ammonium during polymer accumulation did not influence the maximum amount of PHA that was attained. © 2013 Wiley Periodicals, Inc.

  13. Propolis reduces bacterial translocation and intestinal villus atrophy in experimental obstructive jaundice

    PubMed Central

    Sabuncuoglu, Mehmet Zafer; Kismet, Kemal; Kilicoglu, Sibel Serin; Kilicoglu, Bulent; Erel, Serap; Muratoglu, Sabahattin; Sunay, Asli Elif; Erdemli, Esra; Akkus, Mehmet Ali

    2007-01-01

    AIM: To investigate the effects of propolis on bacterial translocation and ultrastructure of intestinal morphology in experimental obstructive jaundice. METHODS: Thirty Wistar-Albino male rats were randomly divided into three groups, each including 10 animals: groupI, sham-operated; group II, ligation and division of the common bile duct (BDL); group III, BDL followed by oral supplementation of propolis 100 mg/kg per day. Liver, blood, spleen, mesenteric lymph nodes, and ileal samples were taken for microbiological, light and transmission electron microscopic examination on postoperative 7th d after sacrification. RESULTS: The mean number of villi per centimeter and mean mucosal height of the propolis group were significantly different in the BDL group (P = 0.001 and 0.012, respectively). The electron microscopic changes were also different between these groups. Sham and BDL + propolis groups had similar incidence of bacterial translocation (BT). The BDL group had significantly higher rates of BT as compared with sham and BDL + propolis groups. BT was predominantly detected in MLNs and the most commonly isolated bacteria was Escherichia coli. CONCLUSION: Propolis showed a significant protective effect on ileal mucosa and reduced bacterial translocation in the experimental obstructive jaundice model. Further studies should be carried out to explain the mechanisms of these effects. PMID:17876893

  14. Bacterial lipopolysaccharide (LPS)-specific antibodies in commercial human immunoglobulin preparations: superior antibody content of an IgM-enriched product

    PubMed Central

    Trautmann, M; Held, T K; Susa, M; Karajan, M A; Wulf, A; Cross, A S; Marre, R

    1998-01-01

    The anti-LPS antibody content of commercial intravenous immunoglobulins was examined by quantitative ELISA using LPS preparations from Escherichia coli, Klebsiella and Pseudomonas aeruginosa O serotypes occurring most frequently in Gram-negative septicaemia. Three IgG products from different manufacturers and one IgM-enriched product were tested. Mean antibody levels were significantly higher in the IgM fraction of the IgM-enriched product compared with ‘pure’ IgG products, indicating that natural antibodies against bacterial LPS belong primarily to the IgM class. Immunoblotting studies showed that antibody specificities were directed mainly against O side chain epitopes. Antibodies against rough mutant LPS representing various chemotypes were detected in IgG but not in IgM products. The virtual absence of antibodies against Vibrio cholerae LPS indicated that human anti-LPS antibodies result from continuous environmental exposure to Gram-negative pathogens. These data support the further development of IgM-enriched preparations for prophylaxis and treatment of Gram-negative nosocomial infections. PMID:9472665

  15. Effect of modeled reduced gravity conditions on bacterial morphology and physiology

    PubMed Central

    2012-01-01

    Background Bacterial phenotypes result from responses to environmental conditions under which these organisms grow; reduced gravity has been demonstrated in many studies as an environmental condition that profoundly influences microorganisms. In this study, we focused on low-shear stress, modeled reduced gravity (MRG) conditions and examined, for Escherichia coli and Staphlyococcus aureus, a suite of bacterial responses (including total protein concentrations, biovolume, membrane potential and membrane integrity) in rich and dilute media and at exponential and stationary phases for growth. The parameters selected have not been studied in E. coli and S. aureus under MRG conditions and provide critical information about bacterial viability and potential for population growth. Results With the exception of S. aureus in dilute Luria Bertani (LB) broth, specific growth rates (based on optical density) of the bacteria were not significantly different between normal gravity (NG) and MRG conditions. However, significantly higher bacterial yields were observed for both bacteria under MRG than NG, irrespective of the medium with the exception of E. coli grown in LB. Also, enumeration of cells after staining with 4',6-diamidino-2-phenylindole showed that significantly higher numbers were achieved under MRG conditions during stationary phase for E. coli and S. aureus grown in M9 and dilute LB, respectively. In addition, with the exception of smaller S. aureus volume under MRG conditions at exponential phase in dilute LB, biovolume and protein concentrations per cell did not significantly differ between MRG and NG treatments. Both E. coli and S. aureus had higher average membrane potential and integrity under MRG than NG conditions; however, these responses varied with growth medium and growth phase. Conclusions Overall, our data provides novel information about E. coli and S. aureus membrane potential and integrity and suggest that bacteria are physiologically more active and

  16. Effect of modeled reduced gravity conditions on bacterial morphology and physiology.

    PubMed

    Vukanti, Raja; Model, Michael A; Leff, Laura G

    2012-01-12

    Bacterial phenotypes result from responses to environmental conditions under which these organisms grow; reduced gravity has been demonstrated in many studies as an environmental condition that profoundly influences microorganisms. In this study, we focused on low-shear stress, modeled reduced gravity (MRG) conditions and examined, for Escherichia coli and Staphlyococcus aureus, a suite of bacterial responses (including total protein concentrations, biovolume, membrane potential and membrane integrity) in rich and dilute media and at exponential and stationary phases for growth. The parameters selected have not been studied in E. coli and S. aureus under MRG conditions and provide critical information about bacterial viability and potential for population growth. With the exception of S. aureus in dilute Luria Bertani (LB) broth, specific growth rates (based on optical density) of the bacteria were not significantly different between normal gravity (NG) and MRG conditions. However, significantly higher bacterial yields were observed for both bacteria under MRG than NG, irrespective of the medium with the exception of E. coli grown in LB. Also, enumeration of cells after staining with 4',6-diamidino-2-phenylindole showed that significantly higher numbers were achieved under MRG conditions during stationary phase for E. coli and S. aureus grown in M9 and dilute LB, respectively. In addition, with the exception of smaller S. aureus volume under MRG conditions at exponential phase in dilute LB, biovolume and protein concentrations per cell did not significantly differ between MRG and NG treatments. Both E. coli and S. aureus had higher average membrane potential and integrity under MRG than NG conditions; however, these responses varied with growth medium and growth phase. Overall, our data provides novel information about E. coli and S. aureus membrane potential and integrity and suggest that bacteria are physiologically more active and a larger percentage are viable

  17. Reduced Set of Virulence Genes Allows High Accuracy Prediction of Bacterial Pathogenicity in Humans

    PubMed Central

    Iraola, Gregorio; Vazquez, Gustavo; Spangenberg, Lucía; Naya, Hugo

    2012-01-01

    Although there have been great advances in understanding bacterial pathogenesis, there is still a lack of integrative information about what makes a bacterium a human pathogen. The advent of high-throughput sequencing technologies has dramatically increased the amount of completed bacterial genomes, for both known human pathogenic and non-pathogenic strains; this information is now available to investigate genetic features that determine pathogenic phenotypes in bacteria. In this work we determined presence/absence patterns of different virulence-related genes among more than finished bacterial genomes from both human pathogenic and non-pathogenic strains, belonging to different taxonomic groups (i.e: Actinobacteria, Gammaproteobacteria, Firmicutes, etc.). An accuracy of 95% using a cross-fold validation scheme with in-fold feature selection is obtained when classifying human pathogens and non-pathogens. A reduced subset of highly informative genes () is presented and applied to an external validation set. The statistical model was implemented in the BacFier v1.0 software (freely available at ), that displays not only the prediction (pathogen/non-pathogen) and an associated probability for pathogenicity, but also the presence/absence vector for the analyzed genes, so it is possible to decipher the subset of virulence genes responsible for the classification on the analyzed genome. Furthermore, we discuss the biological relevance for bacterial pathogenesis of the core set of genes, corresponding to eight functional categories, all with evident and documented association with the phenotypes of interest. Also, we analyze which functional categories of virulence genes were more distinctive for pathogenicity in each taxonomic group, which seems to be a completely new kind of information and could lead to important evolutionary conclusions. PMID:22916122

  18. Dethiosulfatibacter aminovorans gen. nov., sp. nov., a novel thiosulfate-reducing bacterium isolated from coastal marine sediment via sulfate-reducing enrichment with Casamino acids.

    PubMed

    Takii, Susumu; Hanada, Satoshi; Tamaki, Hideyuki; Ueno, Yutaka; Sekiguchi, Yuji; Ibe, Akihiro; Matsuura, Katsumi

    2007-10-01

    A sulfate-reducing enrichment culture originating from coastal marine sediment of the eutrophic Tokyo Bay, Japan, was successfully established with Casamino acids as a substrate. A thiosulfate reducer, strain C/G2(T), was isolated from the enrichment culture after further enrichment with glutamate. Cells of strain C/G2(T) were non-motile rods (0.6-0.8 microm x 2.2-4.8 microm) and were found singly or in pairs and sometimes in short chains. Spores were not formed. Cells of strain C/G2(T) stained Gram-negatively, despite possessing Gram-positive cell walls. The optimum temperature for growth was 28-30 degrees C, the optimum pH was around 7.8 and the optimum salt concentration was 20-30 g l(-1). Lactate, pyruvate, serine, cysteine, threonine, glutamate, histidine, lysine, arginine, Casamino acids, peptone and yeast extract were fermented as single substrates and no sugar was used as a fermentative substrate. A Stickland reaction was observed with some pairs of amino acids. Fumarate, alanine, proline, phenylalanine, tryptophan, glutamine and aspartate were utilized only in the presence of thiosulfate. Strain C/G2(T) fermented glutamate to H2, CO2, acetate and propionate. Thiosulfate and elemental sulfur were reduced to sulfide. Sulfate, sulfite and nitrate were not utilized as electron acceptors. The growth of strain C/G2(T) on Casamino acids or glutamate was enhanced by co-culturing with Desulfovibrio sp. isolated from the original mixed culture enriched with Casamino acids. The DNA G+C content of strain C/G2(T) was 41.0 mol%. Phylogenetic analysis based on 16S rRNA gene sequences showed that strain C/G2(T) formed a distinct cluster with species of the genus Sedimentibacter. The closest relative was Sedimentibacter hydroxybenzoicus (with a gene sequence similarity of 91 %). On the basis of its phylogenetic and phenotypic properties, strain C/G2(T) (=JCM 13356(T)=NBRC 101112(T)=DSM 17477(T)) is proposed as representing a new genus and novel species, Dethiosulfatibacter

  19. A Walnut-Enriched Diet Reduces the Growth of LNCaP Human Prostate Cancer Xenografts in Nude Mice

    PubMed Central

    Tan, Dun-Xian; Manchester, Lucien C.; Korkmaz, Ahmet; Fuentes-Broto, Lorena; Hardman, W. Elaine; Rosales-Corral, Sergio A.; Qi, Wenbo

    2013-01-01

    It was investigated whether a standard mouse diet (AIN-76A) supplemented with walnuts reduced the establishment and growth of LNCaP human prostate cancer cells in nude (nu/nu) mice. The walnut-enriched diet reduced the number of tumors and the growth of the LNCaP xenografts; 3 of 16 (18.7%) of the walnut-fed mice developed tumors; conversely, 14 of 32 mice (44.0%) of the control diet-fed animals developed tumors. Similarly, the xenografts in the walnut-fed animals grew more slowly than those in the control diet mice. The final average tumor size in the walnut-diet animals was roughly one-fourth the average size of the prostate tumors in the mice that ate the control diet. PMID:23758186

  20. Mountain Pine Beetles Colonizing Historical and Naïve Host Trees Are Associated with a Bacterial Community Highly Enriched in Genes Contributing to Terpene Metabolism

    PubMed Central

    Adams, Aaron S.; Aylward, Frank O.; Adams, Sandye M.; Erbilgin, Nadir; Aukema, Brian H.; Currie, Cameron R.

    2013-01-01

    The mountain pine beetle, Dendroctonus ponderosae, is a subcortical herbivore native to western North America that can kill healthy conifers by overcoming host tree defenses, which consist largely of high terpene concentrations. The mechanisms by which these beetles contend with toxic compounds are not well understood. Here, we explore a component of the hypothesis that beetle-associated bacterial symbionts contribute to the ability of D. ponderosae to overcome tree defenses by assisting with terpene detoxification. Such symbionts may facilitate host tree transitions during range expansions currently being driven by climate change. For example, this insect has recently breached the historical geophysical barrier of the Canadian Rocky Mountains, providing access to näive tree hosts and unprecedented connectivity to eastern forests. We use culture-independent techniques to describe the bacterial community associated with D. ponderosae beetles and their galleries from their historical host, Pinus contorta, and their more recent host, hybrid P. contorta-Pinus banksiana. We show that these communities are enriched with genes involved in terpene degradation compared with other plant biomass-processing microbial communities. These pine beetle microbial communities are dominated by members of the genera Pseudomonas, Rahnella, Serratia, and Burkholderia, and the majority of genes involved in terpene degradation belong to these genera. Our work provides the first metagenome of bacterial communities associated with a bark beetle and is consistent with a potential microbial contribution to detoxification of tree defenses needed to survive the subcortical environment. PMID:23542624

  1. Mountain pine beetles colonizing historical and naive host trees are associated with a bacterial community highly enriched in genes contributing to terpene metabolism.

    PubMed

    Adams, Aaron S; Aylward, Frank O; Adams, Sandye M; Erbilgin, Nadir; Aukema, Brian H; Currie, Cameron R; Suen, Garret; Raffa, Kenneth F

    2013-06-01

    The mountain pine beetle, Dendroctonus ponderosae, is a subcortical herbivore native to western North America that can kill healthy conifers by overcoming host tree defenses, which consist largely of high terpene concentrations. The mechanisms by which these beetles contend with toxic compounds are not well understood. Here, we explore a component of the hypothesis that beetle-associated bacterial symbionts contribute to the ability of D. ponderosae to overcome tree defenses by assisting with terpene detoxification. Such symbionts may facilitate host tree transitions during range expansions currently being driven by climate change. For example, this insect has recently breached the historical geophysical barrier of the Canadian Rocky Mountains, providing access to näive tree hosts and unprecedented connectivity to eastern forests. We use culture-independent techniques to describe the bacterial community associated with D. ponderosae beetles and their galleries from their historical host, Pinus contorta, and their more recent host, hybrid P. contorta-Pinus banksiana. We show that these communities are enriched with genes involved in terpene degradation compared with other plant biomass-processing microbial communities. These pine beetle microbial communities are dominated by members of the genera Pseudomonas, Rahnella, Serratia, and Burkholderia, and the majority of genes involved in terpene degradation belong to these genera. Our work provides the first metagenome of bacterial communities associated with a bark beetle and is consistent with a potential microbial contribution to detoxification of tree defenses needed to survive the subcortical environment.

  2. Reducing bacterial contamination in fuel ethanol fermentations by ozone treatment of uncooked corn mash.

    PubMed

    Rasmussen, Mary L; Koziel, Jacek A; Jane, Jay-lin; Pometto, Anthony L

    2015-06-03

    Ozonation of uncooked corn mash from the POET BPX process was investigated as a potential disinfection method for reducing bacterial contamination prior to ethanol fermentation. Corn mash (200 g) was prepared from POET ground corn and POET corn slurry and was ozonated in 250 mL polypropylene bottles. Lactic and acetic acid levels were monitored daily during the fermentation of ozonated, aerated, and nontreated corn mash samples to evaluate bacterial activity. Glycerol and ethanol contents of fermentation samples were checked daily to assess yeast activity. No yeast supplementation, no addition of other antimicrobial agents (such as antibiotics), and spiking with a common lactic acid bacterium found in corn ethanol plants, Lactobacillus plantarum, amplified the treatment effects. The laboratory-scale ozone dosages ranged from 26-188 mg/L, with very low estimated costs of $0.0008-0.006/gal ($0.21-1.6/m(3)) of ethanol. Ozonation was found to decrease the initial pH of ground corn mash samples, which could reduce the sulfuric acid required to adjust the pH prior to ethanol fermentation. Lactic and acetic acid levels tended to be lower for samples subjected to increasing ozone dosages, indicating less bacterial activity. The lower ozone dosages in the range applied achieved higher ethanol yields. Preliminary experiments on ozonating POET corn slurry at low ozone dosages were not as effective as using POET ground corn, possibly because corn slurry samples contained recycled antimicrobials from the backset. The data suggest additional dissolved and suspended organic materials from the backset consumed the ozone or shielded the bacteria.

  3. AISI/DOE Technology Roadmap Program: Development of an O2-Enriched Furnace System for Reduced CO2 and NOx Emissions For the Steel Industry

    SciTech Connect

    Edward W. Grandmaison; David J. Poirier; Eric Boyd

    2003-01-20

    An oxygen-enriched furnace system for reduced CO2 and NOx emission has been developed. The furnace geometry, with a sidewall-mounted burner, was similar to configurations commonly encountered in a steel reheat furnace. The effect of stack oxygen concentration, oxygen enrichment level and air infiltration on fuel savings/CO2 reduction, NOx emissions and scale formation were investigated. The firing rate required to maintain the furnace temperature at 1100 C decreased linearly with increasing oxygen enrichment. At full oxygen enrichment a reduction of 40-45% in the firing rate was required to maintain furnace temperature. NOx emissions were relatively constant at oxygen enrichment levels below 60% and decreased concentration at all oxygen enrichment levels. Air infiltration also had an effect on NOx levels leading to emissions similar to those observed with no air infiltration but with similar stack oxygen concentrations. At high oxygen enrichment levels, there was a larger variation in the refractory surface-temperature on the roof and blind sidewall of the furnace. Scale habit, intactness, adhesion and oxidation rates were examined for five grades of steel over a range of stack oxygen concentrations and oxygen enrichment levels at 1100 degree C. The steel grade had the largest effect on scaling properties examined in this work. The stack oxygen concentration and the oxygen enrichment level had much smaller effects on the scaling properties.

  4. Topical Nanoemulsion Therapy Reduces Bacterial Wound Infection and Inflammation Following Burn Injury

    PubMed Central

    Hemmila, Mark R.; Mattar, Aladdein; Taddonio, Michael A.; Arbabi, Saman; Hamouda, Tarek; Ward, Peter A.; Wang, Stewart C.; Baker, James R.

    2010-01-01

    Background Nanoemulsions are broadly antimicrobial oil-in-water emulsions containing nanometer-sized droplets stabilized with surfactants. We hypothesize that topical application of a nanoemulsion compound (NB-201) can attenuate burn wound infection. In addition to reducing infection, nanoemulsion therapy may modulate dermal inflammatory signaling and thereby lessen inflammation following thermal injury. Methods Male Sprague-Dawley rats underwent a 20% total body surface area (TBSA) scald burn to create a partial thickness burn injury. Animals were resuscitated with Ringer’s lactate and the wound covered with an occlusive dressing. Eight hours after injury, the burn wound was inoculated with 1×106 CFU of Pseudomonas aeruginosa. NB-201, NB-201 placebo, 5% mafenide acetate solution or 0.9% saline (control) was applied onto the wound at 16 and 24 hrs following burn injury. Skin was harvested 32 hrs post-burn for quantitative wound culture and determination of inflammatory mediators in tissue homogenates. Results NB-201 reduced mean bacterial growth in the burn wound by a thousand fold, with only 11% animals having P. aeruginosa counts greater than 105 CFU/g tissue versus 91% in the control group (p<0.0001). Treatment with NB-201 attenuated neutrophil sequestration in the treatment group as measured by myeloperoxidase assay and by histology. It also, significantly reduced levels of pro-inflammatory cytokines (IL-1β and IL-6) and the degree of hair follicle cell apoptosis in skin when compared to saline-treated controls. Conclusions Topical NB-201 substantially reduced bacterial growth in a partial thickness burn model. This reduction in the level of wound infection was associated with an attenuation of the local dermal inflammatory response and diminished neutrophil sequestration. NB-201 represents a novel potent antimicrobial and antiinflammatory treatment for use in burn wounds. PMID:20189619

  5. A surfactant-based wound dressing can reduce bacterial biofilms in a porcine skin explant model.

    PubMed

    Yang, Qingping; Larose, Christelle; Della Porta, Alessandra C; Schultz, Gregory S; Gibson, Daniel J

    2017-04-01

    Bacterial biofilms have been found in many, if not all, chronic wounds. Their excessive extracellular matrix secretion and the metabolic changes that they undergo render them highly tolerant of many antibiotic and antimicrobial treatments. Physical removal and/or disruption are a common approach to treating wounds suspected of having bacterial biofilms. While many of these techniques use mechanical energy as the primary means of removal, we have begun to investigate if surfactants could facilitate the removal of bacterial biofilms, or if they might sensitise the biofilms to antimicrobial interventions. We tested a new surfactant-based wound gel on an ex vivo porcine skin explant model infected with a functionally tolerant 3-day biofilm. The wounds were dressed with a surfactant-based gel directly on the wound or with moistened gauze. The wounds were then wiped daily with moistened gauze, and the gel or gauze was re-applied. Each day, an explant from each group was harvested and tested for total viable bacteria counts and viable biofilm-protected bacteria counts. The results show that daily wiping with moistened gauze led to an initial decrease of bacteria, but by day 3, the biofilm had been fully re-established to the same level prior to the beginning of treatment. For the surfactant-based treatment, there was no detectable functional biofilm after the first treatment. The gauze control, which was also subjected to daily wiping, still contained functional biofilms, indicating that this result was not due to wiping alone. The total bacteria in the surfactant-treated explants steadily decreased through day 3, when there were no detectable bacteria, while the wiping-only control bacteria counts remained steady. The use of a moist gauze to wipe the visually apparent slime off of a wound appears to be insufficient to reduce biofilm over a 3-day period. Daily application of the surfactant gel dressing and wiping reduced the biofilm to undetectable levels within 3 days in

  6. Metatranscriptome of an Anaerobic Benzene-Degrading, Nitrate-Reducing Enrichment Culture Reveals Involvement of Carboxylation in Benzene Ring Activation

    PubMed Central

    Luo, Fei; Gitiafroz, Roya; Devine, Cheryl E.; Gong, Yunchen; Hug, Laura A.; Raskin, Lutgarde

    2014-01-01

    The enzymes involved in the initial steps of anaerobic benzene catabolism are not known. To try to elucidate this critical step, a metatranscriptomic analysis was conducted to compare the genes transcribed during the metabolism of benzene and benzoate by an anaerobic benzene-degrading, nitrate-reducing enrichment culture. RNA was extracted from the mixed culture and sequenced without prior mRNA enrichment, allowing simultaneous examination of the active community composition and the differential gene expression between the two treatments. Ribosomal and mRNA sequences attributed to a member of the family Peptococcaceae from the order Clostridiales were essentially only detected in the benzene-amended culture samples, implicating this group in the initial catabolism of benzene. Genes similar to each of two subunits of a proposed benzene-carboxylating enzyme were transcribed when the culture was amended with benzene. Anaerobic benzoate degradation genes from strict anaerobes were transcribed only when the culture was amended with benzene. Genes for other benzoate catabolic enzymes and for nitrate respiration were transcribed in both samples, with those attributed to an Azoarcus species being most abundant. These findings indicate that the mineralization of benzene starts with its activation by a strict anaerobe belonging to the Peptococcaceae, involving a carboxylation step to form benzoate. These data confirm the previously hypothesized syntrophic association between a benzene-degrading Peptococcaceae strain and a benzoate-degrading denitrifying Azoarcus strain for the complete catabolism of benzene with nitrate as the terminal electron acceptor. PMID:24795366

  7. Adequate Hand Washing and Glove Use Are Necessary To Reduce Cross-Contamination from Hands with High Bacterial Loads.

    PubMed

    Robinson, Andrew L; Lee, Hyun Jung; Kwon, Junehee; Todd, Ewen; Rodriguez, Fernando Perez; Ryu, Dojin

    2016-02-01

    Hand washing and glove use are the main methods for reducing bacterial cross-contamination from hands to ready-to-eat food in a food service setting. However, bacterial transfer from hands to gloves is poorly understood, as is the effect of different durations of soap rubbing on bacterial reduction. To assess bacterial transfer from hands to gloves and to compare bacterial transfer rates to food after different soap washing times and glove use, participants' hands were artificially contaminated with Enterobacter aerogenes B199A at ∼9 log CFU. Different soap rubbing times (0, 3, and 20 s), glove use, and tomato dicing activities followed. The bacterial counts in diced tomatoes and on participants' hands and gloves were then analyzed. Different soap rubbing times did not significantly change the amount of bacteria recovered from participants' hands. Dicing tomatoes with bare hands after 20 s of soap rubbing transferred significantly less bacteria (P < 0.01) to tomatoes than did dicing with bare hands after 0 s of soap rubbing. Wearing gloves while dicing greatly reduced the incidence of contaminated tomato samples compared with dicing with bare hands. Increasing soap washing time decreased the incidence of bacteria recovered from outside glove surfaces (P < 0.05). These results highlight that both glove use and adequate hand washing are necessary to reduce bacterial cross-contamination in food service environments.

  8. Composition, Reactivity and Regulation of Extracellular Metal-Reducing Structures (Bacterial Nanowires) Produced by Dissimilatory Metal - Reducing Bacteria.

    SciTech Connect

    Beveridge, Terrance J; Whitfield, Christopher

    2013-03-06

    This is the final technical report for the project. There were two objectives in the proposal. The first was to describe the composition and function of electrically conductive appendages, known as bacterial nanowires, which resemble pili but are longer and are electrically conductive. They were first identified on the dissimilatory metal-reducing bacteria (DMRB), Shewanella and Geobacter. Specifically, this project investigated the role of these structures in: (i) the reductive transformation of iron oxides as solid phase electron acceptors; (ii) the use of as uranium as a dissolved electron acceptor to form nanocrystalline particles of uraninite upon reduction. The Beveridge group investigated these processes using advanced cryo-transmission electron microscopy (cryoTEM) to visualize the points of connection between the distal ends of nanowires and the effect they have on solid phase Fe minerals. At the same time, immuno-electron microscopy was applied in an attempt to identify where metal reductases and cytochromes are located on the cell surface, or in the nanowires. The second objective was to define the surface physicochemistry of Shewanella spp. in an attempt to decipher how weak bonding (electrostatics and hydrophobicity) affects the adherence of the bacteria to Fe oxides. This bonding could be dictated by the chemistry of lipopolysaccharide (LPS), or the presence/absence of capsular polysaccharide.

  9. Reducing Relative Food Reinforcement in Infants by an Enriched Music Experience

    PubMed Central

    Kong, Kai Ling; Eiden, Rina D.; Feda, Denise M.; Stier, Corrin L.; Fletcher, Kelly D.; Woodworth, Elizabeth M.; Paluch, Rocco A.; Epstein, Leonard H.

    2017-01-01

    Objective The reinforcing value of food may be established early in life. Research shows that infant weight status is related to the relative reinforcing value of food versus non-food alternatives (food reinforcing ratio, FRR). The purpose of this pilot study was to assess the effects of a 6-week music enhancement program (Music Together®, n = 14) versus an active play date control group (n = 13) on the FRR in 9- to 16-month-old infants who were high in relative food reinforcement. Methods Participating parents and infants attended six weekly 45-min group classes. Parents in the music group and the play date group were encouraged to listen to the Music Together program CD or play with the play date group’s toy with their infants at home, respectively. Results Intent-to-treat analysis showed a decrease in FRR for infants in the music group (mean ± SD: −0.13 ± 0.13) in comparison to a slight increase in the control group (0.04 ± 0.11) (F[1, 24] = 11.86, P = 0.002). Conclusions These findings provide evidence that relative reinforcing value of food can be reduced by promoting alternative reinforcers at an early age. PMID:27028283

  10. Reducing relative food reinforcement in infants by an enriched music experience.

    PubMed

    Kong, Kai Ling; Eiden, Rina D; Feda, Denise M; Stier, Corrin L; Fletcher, Kelly D; Woodworth, Elizabeth M; Paluch, Rocco A; Epstein, Leonard H

    2016-04-01

    The reinforcing value of food may be established early in life. Research shows that infant weight status is related to the relative reinforcing value of food versus non-food alternatives (food reinforcing ratio, FRR). The purpose of this pilot study was to assess the effects of a 6-week music enhancement program (Music Together®, n = 14) versus an active play date control group (n = 13) on the FRR in 9- to 16-month-old infants who were high in relative food reinforcement. Participating parents and infants attended six weekly 45-min group classes. Parents in the music group and the play date group were encouraged to listen to the Music Together program CD or play with the play date group's toy with their infants at home, respectively. Intent-to-treat analysis showed a decrease in FRR for infants in the music group (mean ± SD: -0.13 ± 0.13) in comparison to a slight increase in the control group (0.04 ± 0.11) (F[1, 24]  = 11.86, P = 0.002). These findings provide evidence that relative reinforcing value of food can be reduced by promoting alternative reinforcers at an early age. © 2016 The Obesity Society.

  11. CO(2) enrichment reduces reproductive dominance in competing stands of Ambrosia artemisiifolia (common ragweed).

    PubMed

    Stinson, K A; Bazzaz, F A

    2006-02-01

    Plants growing in dense stands may not equally acquire or utilize extra carbon gained in elevated CO(2). As a result, reproductive differences between dominant and subordinate plants may be altered under rising CO(2) conditions. We hypothesized that elevated CO(2) would enhance the reproductive allocation of shaded, subordinate Ambrosia artemisiifolia L. (Asteraceae) individuals more than that of light-saturated dominants. We grew stands of A. artemisiifolia at either 360 or 720 muL L(-1) CO(2) levels and measured the growth and reproductive responses of competing individuals. To test whether elevated CO(2) altered size and reproductive inequalities within stands, we compared stand-level coefficients of variation (CV) in height growth and final shoot, root, and reproductive organ biomasses. Elevated CO(2) enhanced biomass and reduced the CV for all aspects of plant growth, especially reproductive biomass. Allocation to reproduction was higher in the elevated CO(2) than in the ambient treatment, and this difference was more pronounced in small, rather than large plant positive relationships between the CV and total stand productivity declined under elevated CO(2), indicating that growth enhancements to smaller plants diminished the relative biomass advantages of larger plants in increasingly crowded conditions. We conclude that elevated CO(2) stimulates stand-level reproduction while CO(2)-induced growth gains of subordinate A. artemisiifolia plants minimize differences in the reproductive output of small and large plants. Thus, more individuals are likely to produce greater amounts of seeds and pollen in future populations of this allergenic weed.

  12. Methylation is the initial reaction in anaerobic naphthalene degradation by a sulfate-reducing enrichment culture.

    PubMed

    Safinowski, Michael; Meckenstock, Rainer U

    2006-02-01

    The sulfate-reducing culture N47 can utilize naphthalene or 2-methylnaphthalene as the sole carbon source and electron donor. Here we show that the initial reaction in the naphthalene degradation pathway is a methylation to 2-methylnaphthalene which then undergoes the subsequent oxidation to the central metabolite 2-naphthoic acid, ring reduction and cleavage. Specific metabolites occurring exclusively during anaerobic degradation of 2-methylnaphthalene were detected during growth on naphthalene, i.e. naphthyl-2-methyl-succinate and naphthyl-2-methylene-succinate. Additionally, all three enzymes involved in anaerobic degradation of 2-methylnaphthalene to 2-naphthoic acid that could be measured in vitro so far, i.e. naphthyl-2-methyl-succinate synthase, succinyl-CoA:naphthyl-2-methyl-succinate CoA-transferase and naphthyl-2-methyl-succinyl-CoA dehydrogenase were also detected in naphthalene-grown cells with similar activities. Induction experiments were performed to study the growth behaviour of the cell when transferred from naphthalene to 2-methylnaphthalene or vice versa. When the cells were transferred from naphthalene to 2-methylnaphthalene they grew immediately, indicating that no new enzymes had to be induced. On the contrary, the transfer of cells from 2-methylnaphthalene to naphthalene caused a lag-phase of almost 100 days demonstrating that an additional catabolic enzyme has to be activated in this case. We propose the methylation as a novel general mechanism of activation reactions in anaerobic degradation of unsubstituted aromatic hydrocarbons.

  13. Streptomyces lunalinharesii 235 prevents the formation of a sulfate-reducing bacterial biofilm.

    PubMed

    Rosa, Juliana Pacheco da; Tibúrcio, Samyra Raquel Gonçalves; Marques, Joana Montezano; Seldin, Lucy; Coelho, Rosalie Reed Rodrigues

    2016-01-01

    Streptomyces lunalinharesii strain 235 produces an antimicrobial substance that is active against sulfate reducing bacteria, the major bacterial group responsible for biofilm formation and biocorrosion in petroleum reservoirs. The use of this antimicrobial substance for sulfate reducing bacteria control is therefore a promising alternative to chemical biocides. In this study the antimicrobial substance did not interfere with the biofilm stability, but the sulfate reducing bacteria biofilm formation was six-fold smaller in carbon steel coupons treated with the antimicrobial substance when compared to the untreated control. A reduction in the most probable number counts of planktonic cells of sulfate reducing bacteria was observed after treatments with the sub-minimal inhibitory concentration, minimal inhibitory concentration, and supra-minimal inhibitory concentration of the antimicrobial substance. Additionally, when the treated coupons were analyzed by scanning electron microscopy, the biofilm formation was found to be substantially reduced when the supra-minimal inhibitory concentration of the antimicrobial substance was used. The coupons used for the biofilm formation had a small weight loss after antimicrobial substance treatment, but corrosion damage was not observed by scanning electron microscopy. The absence of the dsrA gene fragment in the scraped cell suspension after treatment with the supra-minimal inhibitory concentration of the antimicrobial substance suggests that Desulfovibrio alaskensis was not able to adhere to the coupons. This is the first report on an antimicrobial substance produced by Streptomyces active against sulfate reducing bacteria biofilm formation. The application of antimicrobial substance as a potential biocide for sulfate reducing bacteria growth control could be of great interest to the petroleum industry. Copyright © 2016 Sociedade Brasileira de Microbiologia. Published by Elsevier Editora Ltda. All rights reserved.

  14. Precision and sensitivity of the measurement of 15N enrichment in D-alanine from bacterial cell walls using positive/negative ion mass spectrometry

    NASA Technical Reports Server (NTRS)

    Tunlid, A.; Odham, G.; Findlay, R. H.; White, D. C.

    1985-01-01

    Sensitive detection of cellular components from specific groups of microbes can be utilized as 'signatures' in the examination of microbial consortia from soils, sediments or biofilms. Utilizing capillary gas chromatography/mass spectrometry and stereospecific derivatizing agents, D-alanine, a component localized in the prokaryotic (bacterial) cell wall, can be detected reproducibly. Enrichments of D-[15N]alanine determined in E. coli grown with [15N]ammonia can be determined with precision at 1.0 atom%. Chemical ionization with methane gas and the detection of negative ions (M - HF)- and (M - F or M + H - HF)- formed from the heptafluorobutyryl D-2 butanol ester of D-alanine allowed as little as 8 pg (90 fmol) to be detected reproducibly. This method can be utilized to define the metabolic activity in terms of 15N incorporation at the level of 10(3)-10(4) cells, as a function of the 15N-14N ratio.

  15. Precision and sensitivity of the measurement of 15N enrichment in D-alanine from bacterial cell walls using positive/negative ion mass spectrometry

    NASA Technical Reports Server (NTRS)

    Tunlid, A.; Odham, G.; Findlay, R. H.; White, D. C.

    1985-01-01

    Sensitive detection of cellular components from specific groups of microbes can be utilized as 'signatures' in the examination of microbial consortia from soils, sediments or biofilms. Utilizing capillary gas chromatography/mass spectrometry and stereospecific derivatizing agents, D-alanine, a component localized in the prokaryotic (bacterial) cell wall, can be detected reproducibly. Enrichments of D-[15N]alanine determined in E. coli grown with [15N]ammonia can be determined with precision at 1.0 atom%. Chemical ionization with methane gas and the detection of negative ions (M - HF)- and (M - F or M + H - HF)- formed from the heptafluorobutyryl D-2 butanol ester of D-alanine allowed as little as 8 pg (90 fmol) to be detected reproducibly. This method can be utilized to define the metabolic activity in terms of 15N incorporation at the level of 10(3)-10(4) cells, as a function of the 15N-14N ratio.

  16. Anaerobic Biotransformation of High Concentrations of Chloroform by an Enrichment Culture and Two Bacterial Isolates ▿ †

    PubMed Central

    Shan, Huifeng; Kurtz, Harry D.; Mykytczuk, Nadia; Trevors, Jack T.; Freedman, David L.

    2010-01-01

    A fermentative enrichment culture (designated DHM-1) was developed that is capable of cometabolically biotransforming high concentrations of chloroform (CF) to nontoxic end products. Two Pantoea spp. were isolated from DHM-1 that also possess this dechlorination capability. Following acclimation to increasing levels of CF, corn syrup-grown DHM-1 was able to transform over 500 mg/liter CF in the presence of vitamin B12 (approximately 3% of CF on a molar basis) at a rate as high as 22 mg/liter/day in a mineral salts medium. CO, CO2, and organic acids were the predominant biodegradation products, suggesting that hydrolytic reactions predominate during CF transformation. DHM-1 was capable of growing on corn syrup in the presence of high concentrations of CF (as may be present near contaminant source zones in groundwater), which makes it a promising culture for bioaugmentation. Strains DHM-1B and DHM-1T transform CF at rates similar to that of the DHM-1 enrichment culture. The ability of these strains to grow in the presence of high concentrations of CF appears to be related to alteration of membrane fluidity or homeoviscous and homeophasic adaptation. PMID:20693443

  17. Organoheterotrophic Bacterial Abundance Associates with Zinc Removal in Lignocellulose-Based Sulfate-Reducing Systems.

    PubMed

    Drennan, Dina M; Almstrand, Robert; Lee, Ilsu; Landkamer, Lee; Figueroa, Linda; Sharp, Jonathan O

    2016-01-05

    Syntrophic relationships between fermentative and sulfate-reducing bacteria are essential to lignocellulose-based systems applied to the passive remediation of mining-influenced waters. In this study, seven pilot-scale sulfate-reducing bioreactor columns containing varying ratios of alfalfa hay, pine woodchips, and sawdust were analyzed over ∼500 days to investigate the influence of substrate composition on zinc removal and microbial community structure. Columns amended with >10% alfalfa removed significantly more sulfate and zinc than did wood-based columns. Enumeration of sulfate reducers by functional signatures (dsrA) and their putative identification from 16S rRNA genes did not reveal significant correlations with zinc removal, suggesting limitations in this directed approach. In contrast, a strong indicator of zinc removal was discerned in comparing the relative abundance of core microorganisms shared by all reactors (>80% of total community), many of which had little direct involvement in metal or sulfate respiration. The relative abundance of Desulfosporosinus, the dominant putative sulfate reducer within these reactors, correlated to representatives of this core microbiome. A subset of these clades, including Treponema, Weissella, and Anaerolinea, was associated with alfalfa and zinc removal, and the inverse was found for a second subset whose abundance was associated with wood-based columns, including Ruminococcus, Dysgonomonas, and Azospira. The construction of a putative metabolic flowchart delineated syntrophic interactions supporting sulfate reduction and suggests that the production of and competition for secondary fermentation byproducts, such as lactate scavenging, influence bacterial community composition and reactor efficacy.

  18. Point-of-use water disinfection using UV light-emitting diodes to reduce bacterial contamination.

    PubMed

    Nelson, Kristina Y; McMartin, Dena W; Yost, Christopher K; Runtz, Ken J; Ono, Takaya

    2013-08-01

    The treatment process described in this research explores the impact of exposing water samples containing fecal coliforms to the radiation produced by single ultraviolet (UV) light-emitting diodes (LEDs) operating at 265 nm. UV LEDs are long lasting, compact in size and produce more efficient light output than traditional mercury-vapour bulbs, making them ideal for application in point-of-use disinfection systems, such as in remote areas. In this study, contaminated water samples containing either a pure culture of Escherichia coli or tertiary effluent from the City of Regina Wastewater Treatment Plant were used to study the application and efficiency of using UV LEDs for water disinfection. The results indicate that bacterial inactivation was achieved in a time-dependent manner, with 1- and 2.5-log E. coli reductions in water following 20 and 50 min of UV LED exposure, respectively. Ultraviolet radiation was less effective in reducing coliform bacteria in wastewater samples due to the elevated turbidity levels. Further work remains to be completed to optimize the application of UV LEDs for point-of-use disinfection systems; however, the results from this study support that bacterial inactivation using UV LEDs is possible, meriting further future technological development of the LEDs.

  19. Bare below elbows: does this policy affect handwashing efficacy and reduce bacterial colonisation?

    PubMed

    Burger, A; Wijewardena, C; Clayson, S; Greatorex, R A

    2011-01-01

    UK Department of Health guidelines recommend that clinical staff are 'bare below the elbows'. There is a paucity of evidence to support this policy. One may hypothesise that absence of clothing around wrists facilitates more effective handwashing: this study aims to establish whether dress code affects bacterial colonisation before and after handwashing. Sixty-six clinical staff volunteered to take part in the study, noting whether they were bare below the elbows (BBE) or not bare (NB). Using a standardised technique, imprints of left and right fingers, palms, wrists and forearms were taken onto mini agar plates. Imprints were repeated after handwashing. After incubation, colonies per plate were counted, and subcultures taken. Thirty-eight staff were BBE and 28 were not. A total of 1112 plates were cultured. Before handwashing there was no significant difference in number of colonies between BBE and NB groups (Mann-Whitney, P < 0.05). Handwashing reduced the colony count, with greatest effect on fingers, palms and dominant wrists (t-test, P < 0.05). Comparing the two groups again after handwashing revealed no significant difference (Mann-Whitney, P < 0.05). Subcultures revealed predominantly skin flora. There was a large variation in number of colonies cultured. Handwashing resulted in a statistically significant reduction in colony count on fingers, palms and dominant wrist regardless of clothing. We conclude that handwashing produces a significant reduction in number of bacterial colonies on staff hands, and that clothing that is not BBE does not impede this reduction.

  20. Linked Redox Precipitation of Sulfur and Selenium under Anaerobic Conditions by Sulfate-Reducing Bacterial Biofilms

    PubMed Central

    Hockin, Simon L.; Gadd, Geoffrey M.

    2003-01-01

    A biofilm-forming strain of sulfate-reducing bacteria (SRB), isolated from a naturally occurring mixed biofilm and identified by 16S rDNA analysis as a strain of Desulfomicrobium norvegicum, rapidly removed 200 μM selenite from solution during growth on lactate and sulfate. Elemental selenium and elemental sulfur were precipitated outside SRB cells. Precipitation occurred by an abiotic reaction with bacterially generated sulfide. This appears to be a generalized ability among SRB, arising from dissimilatory sulfide biogenesis, and can take place under low redox conditions and in the dark. The reaction represents a new means for the deposition of elemental sulfur by SRB under such conditions. A combination of transmission electron microscopy, environmental scanning electron microscopy, and cryostage field emission scanning electron microscopy were used to reveal the hydrated nature of SRB biofilms and to investigate the location of deposited sulfur-selenium in relation to biofilm elements. When pregrown SRB biofilms were exposed to a selenite-containing medium, nanometer-sized selenium-sulfur granules were precipitated within the biofilm matrix. Selenite was therefore shown to pass through the biofilm matrix before reacting with bacterially generated sulfide. This constitutes an efficient method for the removal of toxic concentrations of selenite from solution. Implications for environmental cycling and the fate of sulfur and selenium are discussed, and a general model for the potential action of SRB in selenium transformations is presented. PMID:14660350

  1. Linked redox precipitation of sulfur and selenium under anaerobic conditions by sulfate-reducing bacterial biofilms.

    PubMed

    Hockin, Simon L; Gadd, Geoffrey M

    2003-12-01

    A biofilm-forming strain of sulfate-reducing bacteria (SRB), isolated from a naturally occurring mixed biofilm and identified by 16S rDNA analysis as a strain of Desulfomicrobium norvegicum, rapidly removed 200 micro M selenite from solution during growth on lactate and sulfate. Elemental selenium and elemental sulfur were precipitated outside SRB cells. Precipitation occurred by an abiotic reaction with bacterially generated sulfide. This appears to be a generalized ability among SRB, arising from dissimilatory sulfide biogenesis, and can take place under low redox conditions and in the dark. The reaction represents a new means for the deposition of elemental sulfur by SRB under such conditions. A combination of transmission electron microscopy, environmental scanning electron microscopy, and cryostage field emission scanning electron microscopy were used to reveal the hydrated nature of SRB biofilms and to investigate the location of deposited sulfur-selenium in relation to biofilm elements. When pregrown SRB biofilms were exposed to a selenite-containing medium, nanometer-sized selenium-sulfur granules were precipitated within the biofilm matrix. Selenite was therefore shown to pass through the biofilm matrix before reacting with bacterially generated sulfide. This constitutes an efficient method for the removal of toxic concentrations of selenite from solution. Implications for environmental cycling and the fate of sulfur and selenium are discussed, and a general model for the potential action of SRB in selenium transformations is presented.

  2. Acute Exposure to Crystalline Silica Reduces Macrophage Activation in Response to Bacterial Lipoproteins

    PubMed Central

    Beamer, Gillian L.; Seaver, Benjamin P.; Jessop, Forrest; Shepherd, David M.; Beamer, Celine A.

    2016-01-01

    Numerous studies have examined the relationship between alveolar macrophages (AMs) and crystalline silica (SiO2) using in vitro and in vivo immunotoxicity models; however, exactly how exposure to SiO2 alters the functionality of AM and the potential consequences for immunity to respiratory pathogens remains largely unknown. Because recognition and clearance of inhaled particulates and microbes are largely mediated by pattern recognition receptors (PRRs) on the surface of AM, we hypothesized that exposure to SiO2 limits the ability of AM to respond to bacterial challenge by altering PRR expression. Alveolar and bone marrow-derived macrophages downregulate TLR2 expression following acute SiO2 exposure (e.g., 4 h). Interestingly, these responses were dependent on interactions between SiO2 and the class A scavenger receptor CD204, but not MARCO. Furthermore, SiO2 exposure decreased uptake of fluorescently labeled Pam2CSK4 and Pam3CSK4, resulting in reduced secretion of IL-1β, but not IL-6. Collectively, our data suggest that SiO2 exposure alters AM phenotype, which in turn affects their ability to uptake and respond to bacterial lipoproteins. PMID:26913035

  3. Bulk and Rhizosphere Soil Bacterial Communities Studied by Denaturing Gradient Gel Electrophoresis: Plant-Dependent Enrichment and Seasonal Shifts Revealed

    PubMed Central

    Smalla, K.; Wieland, G.; Buchner, A.; Zock, A.; Parzy, J.; Kaiser, S.; Roskot, N.; Heuer, H.; Berg, G.

    2001-01-01

    The bacterial rhizosphere communities of three host plants of the pathogenic fungus Verticillium dahliae, field-grown strawberry (Fragaria ananassa Duch.), oilseed rape (Brassica napus L.), and potato (Solanum tuberosum L.), were analyzed. We aimed to determine the degree to which the rhizosphere effect is plant dependent and whether this effect would be increased by growing the same crops in two consecutive years. Rhizosphere or soil samples were taken five times over the vegetation periods. To allow a cultivation-independent analysis, total community DNA was extracted from the microbial pellet recovered from root or soil samples. 16S rDNA fragments amplified by PCR from soil or rhizosphere bacterium DNA were analyzed by denaturing gradient gel electrophoresis (DGGE). The DGGE fingerprints showed plant-dependent shifts in the relative abundance of bacterial populations in the rhizosphere which became more pronounced in the second year. DGGE patterns of oilseed rape and potato rhizosphere communities were more similar to each other than to the strawberry patterns. In both years seasonal shifts in the abundance and composition of the bacterial rhizosphere populations were observed. Independent of the plant species, the patterns of the first sampling times for both years were characterized by the absence of some of the bands which became dominant at the following sampling times. Bacillus megaterium and Arthrobacter sp. were found as predominant populations in bulk soils. Sequencing of dominant bands excised from the rhizosphere patterns revealed that 6 out of 10 bands resembled gram-positive bacteria. Nocardia populations were identified as strawberry-specific bands. PMID:11571180

  4. Microbial characterization of anode-respiring bacteria within biofilms developed from cultures previously enriched in dissimilatory metal-reducing bacteria.

    PubMed

    Pierra, Mélanie; Carmona-Martínez, Alessandro A; Trably, Eric; Godon, Jean-Jacques; Bernet, Nicolas

    2015-11-01

    This work evaluated the use of a culture enriched in DMRB as a strategy to enrich ARB on anodes. DMRB were enriched with Fe(III) as final electron acceptor and then transferred to a potentiostatically-controlled system with an anode as sole final electron acceptor. Three successive iron-enrichment cultures were carried out. The first step of enrichment revealed a successful selection of the high current-producing ARB Geoalkalibacter subterraneus. After few successive enrichment steps, the microbial community analysis in electroactive biofilms showed a significant divergence with an impact on the biofilm electroactivity. Enrichment of ARB in electroactive biofilms through the pre-selection of DMRB should therefore be carefully considered.

  5. Predicting effects of structural stress in a genome-reduced model bacterial metabolism

    PubMed Central

    Güell, Oriol; Sagués, Francesc; Serrano, M. Ángeles

    2012-01-01

    Mycoplasma pneumoniae is a human pathogen recently proposed as a genome-reduced model for bacterial systems biology. Here, we study the response of its metabolic network to different forms of structural stress, including removal of individual and pairs of reactions and knockout of genes and clusters of co-expressed genes. Our results reveal a network architecture as robust as that of other model bacteria regarding multiple failures, although less robust against individual reaction inactivation. Interestingly, metabolite motifs associated to reactions can predict the propagation of inactivation cascades and damage amplification effects arising in double knockouts. We also detect a significant correlation between gene essentiality and damages produced by single gene knockouts, and find that genes controlling high-damage reactions tend to be expressed independently of each other, a functional switch mechanism that, simultaneously, acts as a genetic firewall to protect metabolism. Prediction of failure propagation is crucial for metabolic engineering or disease treatment. PMID:22934134

  6. Predicting effects of structural stress in a genome-reduced model bacterial metabolism

    NASA Astrophysics Data System (ADS)

    Güell, Oriol; Sagués, Francesc; Serrano, M. Ángeles

    2012-08-01

    Mycoplasma pneumoniae is a human pathogen recently proposed as a genome-reduced model for bacterial systems biology. Here, we study the response of its metabolic network to different forms of structural stress, including removal of individual and pairs of reactions and knockout of genes and clusters of co-expressed genes. Our results reveal a network architecture as robust as that of other model bacteria regarding multiple failures, although less robust against individual reaction inactivation. Interestingly, metabolite motifs associated to reactions can predict the propagation of inactivation cascades and damage amplification effects arising in double knockouts. We also detect a significant correlation between gene essentiality and damages produced by single gene knockouts, and find that genes controlling high-damage reactions tend to be expressed independently of each other, a functional switch mechanism that, simultaneously, acts as a genetic firewall to protect metabolism. Prediction of failure propagation is crucial for metabolic engineering or disease treatment.

  7. Predicting effects of structural stress in a genome-reduced model bacterial metabolism.

    PubMed

    Güell, Oriol; Sagués, Francesc; Serrano, M Ángeles

    2012-01-01

    Mycoplasma pneumoniae is a human pathogen recently proposed as a genome-reduced model for bacterial systems biology. Here, we study the response of its metabolic network to different forms of structural stress, including removal of individual and pairs of reactions and knockout of genes and clusters of co-expressed genes. Our results reveal a network architecture as robust as that of other model bacteria regarding multiple failures, although less robust against individual reaction inactivation. Interestingly, metabolite motifs associated to reactions can predict the propagation of inactivation cascades and damage amplification effects arising in double knockouts. We also detect a significant correlation between gene essentiality and damages produced by single gene knockouts, and find that genes controlling high-damage reactions tend to be expressed independently of each other, a functional switch mechanism that, simultaneously, acts as a genetic firewall to protect metabolism. Prediction of failure propagation is crucial for metabolic engineering or disease treatment.

  8. Efficacy of intraoperative surgical irrigation with polihexanide and nitrofurazone in reducing bacterial load after nail removal surgery.

    PubMed

    Becerro de Bengoa Vallejo, Ricardo; Losa Iglesias, Marta Elena; Cervera, Luis Alou; Fernández, David Sevillano; Prieto, José Prieto

    2011-02-01

    A common challenge of nail avulsion surgery is the associated bacterial contamination and infection that can manifest. The toe has a difficult anatomy to antiseptically prepare and properly maintain throughout the surgical procedure, lending to this widespread problem. We conducted a controlled, prospective randomized study to examine the antiseptic efficacy of 3 intraoperative irrigation methods during nail avulsion surgery. We compared intraoperative antiseptic irrigation using 0.9% saline solution (24 patients), 0.2% nitrofurazone (22 patients), and 0.1% polihexanide (25 patients). Swab samples were taken from each patient at 5 distinct stages throughout the surgical procedure, and bacterial culture analysis was performed (positive culture rate, total inocula count, reduction of bacterial load, and identification of specific micro-organisms). All 3 intraoperative irrigation methods reduced the total bacterial load, but polihexanide was significantly more effective. Furthermore, no patient from the polihexanide group developed postoperative infection. The reduction in bacterial load was lost for all 3 methods after partial nail avulsion surgery, returning to similar values as the initial presurgical bacterial load. An intraoperative irrigation step after partial nail avulsion with saline, nitrofurazone, and polihexanide was effective in reducing the bacterial load by 95.2%, 96.6%, and 99.5%, respectively. Our patients underwent phenol-based nail avulsion, resulting in no bacterial load after complete nail removal because of the intrinsic antiseptic nature of the phenol. Intraoperative irrigation with 0.1% polihexanide substantially reduced the bacterial load and subsequent infections, highlighting the importance of an irrigation step in nail avulsion surgery. Copyright © 2010 American Academy of Dermatology, Inc. Published by Mosby, Inc. All rights reserved.

  9. Anti-protozoal and anti-bacterial antibiotics that inhibit protein synthesis kill cancer subtypes enriched for stem cell-like properties

    PubMed Central

    Cuyàs, Elisabet; Martin-Castillo, Begoña; Corominas-Faja, Bruna; Massaguer, Anna; Bosch-Barrera, Joaquim; Menendez, Javier A

    2015-01-01

    Key players in translational regulation such as ribosomes might represent powerful, but hitherto largely unexplored, targets to eliminate drug-refractory cancer stem cells (CSCs). A recent study by the Lisanti group has documented how puromycin, an old antibiotic derived from Streptomyces alboniger that inhibits ribosomal protein translation, can efficiently suppress CSC states in tumorspheres and monolayer cultures. We have used a closely related approach based on Biolog Phenotype Microarrays (PM), which contain tens of lyophilized antimicrobial drugs, to assess the chemosensitivity profiles of breast cancer cell lines enriched for stem cell-like properties. Antibiotics directly targeting active sites of the ribosome including emetine, puromycin and cycloheximide, inhibitors of ribosome biogenesis such as dactinomycin, ribotoxic stress agents such as daunorubicin, and indirect inhibitors of protein synthesis such as acriflavine, had the largest cytotoxic impact against claudin-low and basal-like breast cancer cells. Thus, biologically aggressive, treatment-resistant breast cancer subtypes enriched for stem cell-like properties exhibit exacerbated chemosensitivities to anti-protozoal and anti-bacterial antibiotics targeting protein synthesis. These results suggest that old/existing microbicides might be repurposed not only as new cancer therapeutics, but also might provide the tools and molecular understanding needed to develop second-generation inhibitors of ribosomal translation to eradicate CSC traits in tumor tissues. PMID:25970790

  10. Anti-protozoal and anti-bacterial antibiotics that inhibit protein synthesis kill cancer subtypes enriched for stem cell-like properties.

    PubMed

    Cuyàs, Elisabet; Martin-Castillo, Begoña; Corominas-Faja, Bruna; Massaguer, Anna; Bosch-Barrera, Joaquim; Menendez, Javier A

    2015-01-01

    Key players in translational regulation such as ribosomes might represent powerful, but hitherto largely unexplored, targets to eliminate drug-refractory cancer stem cells (CSCs). A recent study by the Lisanti group has documented how puromycin, an old antibiotic derived from Streptomyces alboniger that inhibits ribosomal protein translation, can efficiently suppress CSC states in tumorspheres and monolayer cultures. We have used a closely related approach based on Biolog Phenotype Microarrays (PM), which contain tens of lyophilized antimicrobial drugs, to assess the chemosensitivity profiles of breast cancer cell lines enriched for stem cell-like properties. Antibiotics directly targeting active sites of the ribosome including emetine, puromycin and cycloheximide, inhibitors of ribosome biogenesis such as dactinomycin, ribotoxic stress agents such as daunorubicin, and indirect inhibitors of protein synthesis such as acriflavine, had the largest cytotoxic impact against claudin-low and basal-like breast cancer cells. Thus, biologically aggressive, treatment-resistant breast cancer subtypes enriched for stem cell-like properties exhibit exacerbated chemosensitivities to anti-protozoal and anti-bacterial antibiotics targeting protein synthesis. These results suggest that old/existing microbicides might be repurposed not only as new cancer therapeutics, but also might provide the tools and molecular understanding needed to develop second-generation inhibitors of ribosomal translation to eradicate CSC traits in tumor tissues.

  11. Using lytic bacteriophages to eliminate or significantly reduce contamination of food by foodborne bacterial pathogens.

    PubMed

    Sulakvelidze, Alexander

    2013-10-01

    Bacteriophages (also called 'phages') are viruses that kill bacteria. They are arguably the oldest (3 billion years old, by some estimates) and most ubiquitous (total number estimated to be 10(30) -10(32) ) known organisms on Earth. Phages play a key role in maintaining microbial balance in every ecosystem where bacteria exist, and they are part of the normal microflora of all fresh, unprocessed foods. Interest in various practical applications of bacteriophages has been gaining momentum recently, with perhaps the most attention focused on using them to improve food safety. That approach, called 'phage biocontrol', typically includes three main types of applications: (i) using phages to treat domesticated livestock in order to reduce their intestinal colonization with, and shedding of, specific bacterial pathogens; (ii) treatments for decontaminating inanimate surfaces in food-processing facilities and other food establishments, so that foods processed on those surfaces are not cross-contaminated with the targeted pathogens; and (iii) post-harvest treatments involving direct applications of phages onto the harvested foods. This mini-review primarily focuses on the last type of intervention, which has been gaining the most momentum recently. Indeed, the results of recent studies dealing with improving food safety, and several recent regulatory approvals of various commercial phage preparations developed for post-harvest food safety applications, strongly support the idea that lytic phages may provide a safe, environmentally-friendly, and effective approach for significantly reducing contamination of various foods with foodborne bacterial pathogens. However, some important technical and nontechnical problems may need to be addressed before phage biocontrol protocols can become an integral part of routine food safety intervention strategies implemented by food industries in the USA.

  12. Occurrence of a bacterial membrane microdomain at the cell division site enriched in phospholipids with polyunsaturated hydrocarbon chains.

    PubMed

    Sato, Sho; Kawamoto, Jun; Sato, Satoshi B; Watanabe, Bunta; Hiratake, Jun; Esaki, Nobuyoshi; Kurihara, Tatsuo

    2012-07-13

    In this study, we found that phospholipids containing an eicosapentaenyl group form a novel membrane microdomain at the cell division site of a Gram-negative bacterium, Shewanella livingstonensis Ac10, using chemically synthesized fluorescent probes. The occurrence of membrane microdomains in eukaryotes and prokaryotes has been demonstrated with various imaging tools for phospholipids with different polar headgroups. However, few studies have focused on the hydrocarbon chain-dependent localization of membrane-resident phospholipids in vivo. We previously found that lack of eicosapentaenoic acid (EPA), a polyunsaturated fatty acid found at the sn-2 position of glycerophospholipids, causes a defect in cell division after DNA replication of S. livingstonensis Ac10. Here, we synthesized phospholipid probes labeled with a fluorescent 7-nitro-2,1,3-benzoxadiazol-4-yl (NBD) group to study the localization of EPA-containing phospholipids by fluorescence microscopy. A fluorescent probe in which EPA was bound to the glycerol backbone via an ester bond was found to be unsuitable for imaging because EPA was released from the probe by in vivo hydrolysis. To overcome this problem, we synthesized hydrolysis-resistant ether-type phospholipid probes. Using these probes, we found that the fluorescence localized between two nucleoids at the cell center during cell division when the cells were grown in the presence of the eicosapentaenyl group-containing probe (N-NBD-1-oleoyl-2-eicosapentaenyl-sn-glycero-3-phosphoethanolamine), whereas this localization was not observed with the oleyl group-containing control probe (N-NBD-1-oleoyl-2-oleyl-sn-glycero-3-phosphoethanolamine). Thus, phospholipids containing an eicosapentaenyl group are specifically enriched at the cell division site. Formation of a membrane microdomain enriched in EPA-containing phospholipids at the nucleoid occlusion site probably facilitates cell division.

  13. Enrichment of dissimilatory Fe(III)-reducing bacteria from groundwater of the Siklós BTEX-contaminated site (Hungary).

    PubMed

    Farkas, Milán; Szoboszlay, Sándor; Benedek, Tibor; Révész, Fruzsina; Veres, Péter Gábor; Kriszt, Balázs; Táncsics, András

    2017-01-01

    Dissimilatory iron-reducing bacteria are commonly found in microbial communities of aromatic hydrocarbon-contaminated subsurface environments where they often play key role in the degradation of the contaminants. The Siklós benzene, toluene, ethylbenzene, and xylene (BTEX)-contaminated area is one of the best characterized petroleum hydrocarbon-contaminated sites of Hungary. Continuous monitoring of the microbial community in the center of the contaminant plume indicated the presence of an emerging Geobacter population and a Rhodoferax phylotype highly associated with aromatic hydrocarbon-contaminated subsurface environments. The aim of the present study was to make an initial effort to enrich Rhodoferax-related and other dissimilatory iron-reducing bacteria from this environment. Accordingly, four slightly different freshwater media were used to enrich Fe(III) reducers, differing only in the form of nitrogen source (organic, inorganic nitrogen or gaseous headspace nitrogen). Although enrichment of the desired Rhodoferax phylotype was not succeeded, Geobacter-related bacteria were readily enriched. Moreover, the different nitrogen sources caused the enrichment of different Geobacter species. Investigation of the diversity of benzylsuccinate synthase gene both in the enrichments and in the initial groundwater sample indicated that the Geobacter population in the center of the contaminant plume may not play a significant role in the anaerobic degradation of toluene.

  14. Fructose-enriched diet induces inflammation and reduces antioxidative defense in visceral adipose tissue of young female rats.

    PubMed

    Kovačević, Sanja; Nestorov, Jelena; Matić, Gordana; Elaković, Ivana

    2017-02-01

    The consumption of refined, fructose-enriched food continuously increases and has been linked to development of obesity, especially in young population. Low-grade inflammation and increased oxidative stress have been implicated in the pathogenesis of obesity-related disorders including type 2 diabetes. In this study, we examined alterations in inflammation and antioxidative defense system in the visceral adipose tissue (VAT) of fructose-fed young female rats, and related them to changes in adiposity and insulin sensitivity. We examined the effects of 9-week fructose-enriched diet applied immediately after weaning on nuclear factor κB (NF-κB) intracellular distribution, and on the expression of pro-inflammatory cytokines (IL-1β and TNFα) and key antioxidative enzymes in the VAT of female rats. Insulin signaling in the VAT was evaluated at the level of insulin receptor substrate-1 (IRS-1) protein and its inhibitory phosphorylation on Ser(307). Fructose-fed rats had increased VAT mass along with increased NF-κB nuclear accumulation and elevated IL-1β, but not TNFα expression. The protein levels of antioxidative defense enzymes, mitochondrial manganese superoxide dismutase 2, and glutathione peroxidase, were reduced, while the protein content of IRS-1 and its inhibitory phosphorylation were not altered by fructose diet. The results suggest that fructose overconsumption-related alterations in pro-inflammatory markers and antioxidative capacity in the VAT of young female rats can be implicated in the development of adiposity, but do not affect inhibitory phosphorylation of IRS-1.

  15. Diversity of bacteria and Archaea in sulphate-reducing enrichment cultures inoculated from serial dilution of Zostera noltii rhizosphere samples.

    PubMed

    Cifuentes, Ana; Antón, Josefa; De Wit, Rutger; Rodríguez-Valera, Francisco

    2003-09-01

    We have analysed the diversity of culturable sulphate-reducing bacteria (SRB) in Zostera noltii colonized sediments from Bassin d'Arcachon (France). Four organic substrates have been tested as well as the combination of H2 and CO2 to select for lithotrophic SRB. All energy sources were supplied in parallel cultures that were amended with yeast extract plus NH4+ and prepared without a source of combined nitrogen, the latter to select for diazotrophic SRB. The 10 different enrichment media were inoculated from serial dilution of rhizosphere samples. The highest dilution cultures yielding positive growth (i.e. 10-7) were studied by molecular techniques (16S rDNA clone libraries, RISA and ARDRA). Lactate as a single organic substrate in combination with a source of combined nitrogen resulted in selection of members of the Desulfovibrionaceae. Surprisingly, when lactate was added without a source of combined nitrogen, Desulfobacteriaceae were selected. A strong influence of the presence or absence of combined nitrogen was also observed for the substrates sucrose and fructose. Whereas the liquid culture growing on sucrose and NH4+ systematically yielded 16S rDNA clones related to an environmental unidentified green sulphur bacterium (OPS185), on plates we were able to isolate a SRB related to Desulfovibrio dechloracetivorans, which likely represents a non-described species. Under diazotrophic conditions, sucrose selected for SRB clones related to the cluster formed by Desulfovibrio zosterae, Desulfovibrio salexigens and Desulfovibrio bastinii. The corresponding isolate obtained on plates showed only low sequence similarity with this closest neighbour (93.8%), and we suggest that it also represents a non-described species. Surprisingly, a 16S rDNA sequence corresponding to an archaeon, i.e. a non-extremophile Crenoarchaeota, was retrieved from several of the SRB enrichment cultures even after subsequent transfers.

  16. Environmental Enrichment Modified Epigenetic Mechanisms in SAMP8 Mouse Hippocampus by Reducing Oxidative Stress and Inflammaging and Achieving Neuroprotection

    PubMed Central

    Griñan-Ferré, Christian; Puigoriol-Illamola, Dolors; Palomera-Ávalos, Verónica; Pérez-Cáceres, David; Companys-Alemany, Júlia; Camins, Antonio; Ortuño-Sahagún, Daniel; Rodrigo, M. Teresa; Pallàs, Mercè

    2016-01-01

    With the increase in life expectancy, aging and age-related cognitive impairments are becoming one of the most important issues for human health. At the same time, it has been shown that epigenetic mechanisms are emerging as universally important factors in life expectancy. The Senescence Accelerated Mouse P8 (SAMP8) strain exhibits age-related deterioration evidenced in learning and memory abilities and is a useful model of neurodegenerative disease. In SAMP8, Environmental Enrichment (EE) increased DNA-methylation levels (5-mC) and reduced hydroxymethylation levels (5-hmC), as well as increased histone H3 and H4 acetylation levels. Likewise, we found changes in the hippocampal gene expression of some chromatin-modifying enzyme genes, such as Dnmt3b. Hdac1. Hdac2. Sirt2, and Sirt6. Subsequently, we assessed the effects of EE on neuroprotection-related transcription factors, such as the Nuclear regulatory factor 2 (Nrf2)–Antioxidant Response Element pathway and Nuclear Factor kappa Beta (NF-κB), which play critical roles in inflammation. We found that EE produces an increased expression of antioxidant genes, such as Hmox1. Aox1, and Cox2, and reduced the expression of inflammatory genes such as IL-6 and Cxcl10, all of this within the epigenetic context modified by EE. In conclusion, EE prevents epigenetic changes that promote or drive oxidative stress and inflammaging. PMID:27803663

  17. Pilot-scale chitin extraction from shrimp shell waste by deproteination and decalcification with bacterial enrichment cultures.

    PubMed

    Bajaj, Mini; Freiberg, Andrea; Winter, Josef; Xu, Youmei; Gallert, Claudia

    2015-11-01

    Extraction of chitin from mechanically pre-purified shrimp shells can be achieved by successive NaOH/HCl treatment, protease/HCl treatment or by environmentally friendly fermentation with proteolytic/lactic acid bacteria (LAB). For the last mentioned alternative, scale-up of shrimp shell chitin purification was investigated in 0.25 L (F1), 10 L (F2), and 300 L (F3) fermenters using an anaerobic, chitinase-deficient, proteolytic enrichment culture from ground meat for deproteination and a mixed culture of LAB from bio-yoghurt for decalcification. Protein removal in F1, F2, and F3 proceeded in parallel within 40 h at an efficiency of 89-91 %. Between 85 and 90 % of the calcit was removed from the shells by LAB in another 40 h in F1, F2, and F3. After deproteination of shrimp shells in F3, spent fermentation liquor was re-used for a next batch of 30-kg shrimp shells in F4 (300 L) which eliminated 85.5 % protein. The purity of the resulting chitin was comparable in F1, F2, F3, and F4. Viscosities of chitosan, obtained after chitin deacetylation and of chitin, prepared biologically or chemically in the laboratory, were much higher than those of commercially available chitin and chitosan.

  18. Topical nanoemulsion therapy reduces bacterial wound infection and inflammation after burn injury.

    PubMed

    Hemmila, Mark R; Mattar, Aladdein; Taddonio, Michael A; Arbabi, Saman; Hamouda, Tarek; Ward, Peter A; Wang, Stewart C; Baker, James R

    2010-09-01

    Nanoemulsions are broadly antimicrobial oil-in-water emulsions containing nanometer-sized droplets stabilized with surfactants. We hypothesize that topical application of a nanoemulsion compound (NB-201) can attenuate burn wound infection. In addition to reducing infection, nanoemulsion therapy may modulate dermal inflammatory signaling and thereby lessen inflammation following thermal injury. Male Sprague-Dawley rats underwent a 20% total body surface area scald burn to create a partial-thickness burn injury. Animals were resuscitated with Ringer's lactate solution and the wound covered with an occlusive dressing. At 8 hours after injury, the burn wound was inoculated with 1 x 10(6) colony-forming units (CFUs) of Pseudomonas aeruginosa. NB-201, NB-201 placebo, 5% mafenide acetate solution, or 0.9% saline (control) was applied onto the wound at 16 and 24 hours after burn injury. Skin was harvested 32 hours postburn for quantitative wound culture and determination of inflammatory mediators in tissue homogenates. NB-201 decreased mean bacterial growth in the burn wound by 1,000-fold, with only 13% (3/23) of animals having P. aeruginosa counts greater than 10(5) CFU/g tissue versus 91% (29/32) in the control group (P < .0001). Treatment with NB-201 attenuated neutrophil sequestration in the treatment group as measured by myeloperoxidase assay and by histology. It also significantly decreased levels of proinflammatory cytokines (interleukin [IL]-1beta and IL-6) and the degree of hair follicle cell apoptosis in skin compared to saline-treated controls. Topical NB-201 substantially decreased bacterial growth in a partial-thickness burn model. This decrease in the level of wound infection was associated with an attenuation of the local dermal inflammatory response and diminished neutrophil sequestration. NB-201 represents a novel potent antimicrobial and anti-inflammatory treatment for use in burn wounds. Copyright 2010 Mosby, Inc. All rights reserved.

  19. Bare below elbows: does this policy affect handwashing efficacy and reduce bacterial colonisation?

    PubMed Central

    Burger, A; Wijewardena, C; Clayson, S; Greatorex, RA

    2010-01-01

    INTRODUCTION UK Department of Health guidelines recommend that clinical staff are ‘bare below the elbows’. There is a paucity of evidence to support this policy. One may hypothesise that absence of clothing around wrists facilitates more effective handwashing: this study aims to establish whether dress code affects bacterial colonisation before and after handwashing. SUBJECTS AND METHODS Sixty-six clinical staff volunteered to take part in the study, noting whether they were bare below the elbows (BBE) or not bare (NB). Using a standardised technique, imprints of left and right fingers, palms, wrists and forearms were taken onto mini agar plates. Imprints were repeated after handwashing. After incubation, colonies per plate were counted, and subcultures taken. RESULTS Thirty-eight staff were BBE and 28 were not. A total of 1112 plates were cultured. Before handwashing there was no significant difference in number of colonies between BBE and NB groups (Mann–Whitney, P < 0.05). Handwashing reduced the colony count, with greatest effect on fingers, palms and dominant wrists (t-test, P < 0.05). Comparing the two groups again after handwashing revealed no significant difference (Mann–Whitney, P < 0.05). Subcultures revealed predominantly skin flora. CONCLUSIONS There was a large variation in number of colonies cultured. Handwashing resulted in a statistically significant reduction in colony count on fingers, palms and dominant wrist regardless of clothing. We conclude that handwashing produces a significant reduction in number of bacterial colonies on staff hands, and that clothing that is not BBE does not impede this reduction. PMID:20727253

  20. Bioactive glass fillers reduce bacterial penetration into marginal gaps for composite restorations

    PubMed Central

    Khvostenko, D.; Hilton, T. J.; Ferracane, J. L.; Mitchell, J. C.; Kruzic, J. J.

    2015-01-01

    Objectives Bioactive glass (BAG) is known to possess antimicrobial and remineralizing properties; however, the use of BAG as a filler for resin based composite restorations to slow recurrent caries has not been studied. Accordingly, the objective of this study was to investigate the effect of 15 wt% BAG additions to a resin composite on bacterial biofilms penetrating into marginal gaps of simulated tooth fillings in vitro during cyclic mechanical loading. Methods Human molars were machined into approximately 3 mm thick disks of dentin and 1.5–2 mm deep composite restorations were placed. A narrow 15–20 micrometer wide dentin-composite gap was allowed to form along half of the margin by not applying dental adhesive to that region. Two different 72 wt% filled composites were used, one with 15 wt% BAG filler (15BAG) and the balance silanated strontium glass and one filled with OX-50 and silanated strontium glass without BAG (0BAG – control). Samples of both groups had Streptococcus mutans biofilms grown on the surface and were tested inside a bioreactor for two weeks while subjected to periods of cyclic mechanical loading. After post-test biofilm viability was confirmed, each specimen was fixed in glutaraldehyde, gram positive stained, mounted in resin and cross-sectioned to reveal the gap profile. Depth of biofilm penetration for 0BAG and 15BAG was quantified as the fraction of gap depth. The data were compared using a Student’s t-test. Results The average depth of bacterial penetration into the marginal gap for the 15BAG samples was significantly smaller (~61%) in comparison to 0BAG, where 100% penetration was observed for all samples with the biofilm penetrating underneath of the restoration in some cases. Significance BAG containing resin dental composites reduce biofilm penetration into marginal gaps of simulated tooth restorations. This suggests BAG containing composites may have the potential to slow the development and propagation of secondary tooth

  1. CYP3A-dependent drug metabolism is reduced in bacterial inflammation in mice

    PubMed Central

    Gandhi, AS; Guo, T; Shah, P; Moorthy, B; Chow, DS-L; Hu, M; Ghose, R

    2012-01-01

    BACKGROUND AND PURPOSE Gene expression of Cyp3a11 is reduced by activation of Toll-like receptors (TLRs) by Gram-negative or Gram-positive bacterial components, LPS or lipoteichoic acid (LTA) respectively. The primary adaptor protein in the TLR signalling pathway, TIRAP, plays differential roles in LPS- and LTA-mediated down-regulations of Cyp3a11 mRNA. Here, we have determined the functional relevance of these findings by pharmacokinetic/pharmacodynamic (PK/PD) analysis of the Cyp3a substrate midazolam in mice. Midazolam is also metabolized by Cyp2c in mice. EXPERIMENTAL APPROACH Adult male C57BL/6, TIRAP+/+ and TIRAP−/− mice were pretreated with saline, LPS (2 mg·kg−1) or LTA (6 mg·kg−1). Cyp3a11 protein expression, activity and PK/PD studies using midazolam were performed. KEY RESULTS Cyp3a11 protein expression in LPS- or LTA-treated mice was reduced by 95% and 60% compared with saline-treated mice. Cyp3a11 activity was reduced by 70% in LPS- or LTA-treated mice. Plasma AUC of midazolam was increased two- to threefold in LPS- and LTA-treated mice. Plasma levels of 1′-OHMDZ decreased significantly only in LTA-treated mice. Both LPS and LTA decreased AUC of 1′-OHMDZ-glucuronide. In the PD study, sleep time was increased by ∼2-fold in LPS- and LTA-treated mice. LTA-mediated decrease in Cyp3a11 protein expression and activity was dependent on TIRAP. In PK/PD correlation, AUC of midazolam was increased only in LPS-treated mice compared with saline-treated mice. CONCLUSIONS AND IMPLICATIONS LPS or LTA altered PK/PD of midazolam. This is the first study to demonstrate mechanistic differences in regulation of metabolite formation of a clinically relevant drug by Gram-negative or Gram-positive bacterial endotoxins. PMID:22394353

  2. A review of current strategies to reduce intraoperative bacterial contamination of surgical wounds

    PubMed Central

    Dohmen, Pascal M.; Konertz, Wolfgang

    2007-01-01

    Surgical site infections are a mean topic in cardiac surgery, leading to a prolonged hospitalization, and substantially increased morbidity and mortality. One source of pathogens is the endogenous flora of the patient’s skin, which can contaminate the surgical site. A number of preoperative skin care strategies are performed to reduce bacterial contamination like preoperative antiseptic showering, hair removal, antisepsis of the skin, adhesive barrier drapes, and antimicrobial prophylaxis. Furthermore we can also support the natural host defense by optimal intra-operative management of oxygen supply, normoglycemia, and temperature. Nevertheless we still have a number of patients, who develop a surgical site infection. Therefore new skin care strategies are introduced to reduce the contamination by the endogenous skin flora. We present the use of a new microbial sealant, InteguSeal®, which was evaluated in patients undergoing cardiac surgery. The preliminary results of this investigation showed a trend in surgical site infection reduction by the use of this new microbial sealant. PMID:20204082

  3. Bacterial diversity of autotrophic enriched cultures from remote, glacial Antarctic, Alpine and Andean aerosol, snow and soil samples

    NASA Astrophysics Data System (ADS)

    González-Toril, E.; Amils, R.; Delmas, R. J.; Petit, J.-R.; Komárek, J.; Elster, J.

    2009-01-01

    Four different communities and one culture of autotrophic microbial assemblages were obtained by incubation of samples collected from high elevation snow in the Alps (Mt. Blanc area) and the Andes (Nevado Illimani summit, Bolivia), from Antarctic aerosol (French station Dumont d'Urville) and a maritime Antarctic soil (King George Island, South Shetlands, Uruguay Station Artigas), in a minimal mineral (oligotrophic) media. Molecular analysis of more than 200 16S rRNA gene sequences showed that all cultured cells belong to the Bacteria domain. Phylogenetic comparison with the currently available rDNA database allowed sequences belonging to Proteobacteria Alpha-, Beta- and Gamma-proteobacteria), Actinobacteria and Bacteroidetes phyla to be identified. The Andes snow culture was the richest in bacterial diversity (eight microorganisms identified) and the marine Antarctic soil the poorest (only one). Snow samples from Col du Midi (Alps) and the Andes shared the highest number of identified microorganisms (Agrobacterium, Limnobacter, Aquiflexus and two uncultured Alphaproteobacteria clones). These two sampling sites also shared four sequences with the Antarctic aerosol sample (Limnobacter, Pseudonocardia and an uncultured Alphaproteobacteriaclone). The only microorganism identified in the Antarctica soil (Brevundimonas sp.) was also detected in the Antarctic aerosol. Most of the identified microorganisms had been detected previously in cold environments, marine sediments soils and rocks. Air current dispersal is the best model to explain the presence of very specific microorganisms, like those identified in this work, in environments very distant and very different from each other.

  4. Inoculation of a phenanthrene-degrading endophytic bacterium reduces the phenanthrene level and alters the bacterial community structure in wheat.

    PubMed

    Liu, Juan; Xiang, Yanbing; Zhang, Zhiming; Ling, Wanting; Gao, Yanzheng

    2017-03-28

    Colonization by polycyclic aromatic hydrocarbon (PAH)-degrading endophytic bacteria (PAHDEB) can reduce the PAH contamination risk in plant. However, little information is available on the impact of PAHDEB colonization on the endophytic bacterial community of inner plant tissues. A phenanthrene-degrading endophytic bacterium (PDEB), Massilia sp. Pn2, was inoculated onto the roots of wheat and subjected to greenhouse container experiments. The endophytic bacterial community structure in wheat was investigated using high-throughput sequencing technology. The majority of endophytic bacteria in wheat were Proteobacteria, and the dominant genus was Pseudomonas. Phenanthrene contamination clearly increased the diversity of endophytic bacteria in wheat. The cultivable endophytic bacteria counts in wheat decreased with increasing the level of phenanthrene contamination; the endophytic bacterial community structure changed correspondingly, and the bacterial richness first increased and then decreased. Inoculation of strain Pn2 reduced the phenanthrene contamination in wheat, enlarged the biomass of wheat roots, changed the bacterial community structure and enhanced the cell counts, diversity and richness of endophytic bacteria in phenanthrene-contaminated wheat in a contamination level-dependent manner. The findings of this investigation provide insight into the responses of endophytic bacterial community in plant to external PAH contamination and PAHDEB colonization.

  5. Enrichment of carotenoids in flaxseed (Linum usitatissimum) by metabolic engineering with introduction of bacterial phytoene synthase gene crtB.

    PubMed

    Fujisawa, Masaki; Watanabe, Mio; Choi, Song-Kang; Teramoto, Maki; Ohyama, Kanji; Misawa, Norihiko

    2008-06-01

    Linseed flax (Linum usitatissimum L.) is an industrially important oil crop, which includes large amounts of alpha-linolenic acid (18:3) and lignan in its seed oil. We report here the metabolic engineering of flax plants to increase carotenoid amount in seeds. Agrobacterium-mediated transformation of flax was performed to express the phytoene synthase gene (crtB) derived from the soil bacterium Pantoea ananatis (formerly called Erwinia uredovora 20D3) under the control of the cauliflower mosaic virus (CaMV) 35S constitutive promoter or the Arabidopsis thaliana fatty acid elongase 1 gene (FAE1) seed-specific promoter. As a result, eight transgenic flax plants were generated. They formed orange seeds (embryos), in which phytoene, alpha-carotene, and beta-carotene were newly accumulated in addition to increased amounts of lutein, while untransformed flax plants formed light-yellow seeds, in which only lutein was detected. Interestingly, despite the control of the CaMV 35S promoter, the expression of crtB was not observed in the leaves but in the seeds in the transgenic flax plants. Total carotenoid amounts in these seeds were 65.4-156.3 microg/g fresh weight, which corresponded to 7.8- to 18.6-fold increase, compared with those of untransformed controls. These results suggest that the flux of phytoene synthesis from geranylgeranyl diphosphate was first promoted by the expressed crtB gene product (CrtB), and then phytoene was consecutively decomposed to the downstream metabolites alpha-carotene, beta-carotene, and lutein, as catalyzed by endogenous carotenoid biosynthetic enzymes in seeds. The transgenic flaxseeds enriched with the carotenoids could be valuable as nutritional sources for human health.

  6. Changes in glucose fermentation pathways by an enriched bacterial culture in response to regulated dissolved H2 concentrations.

    PubMed

    Zheng, Hang; Zeng, Raymond J; Duke, Mikel C; O'Sullivan, Cathryn A; Clarke, William P

    2015-06-01

    It is well established that metabolic pathways in the fermentation of organic waste are primarily controlled by dissolved H2 concentrations, but there is no reported study that compares observed and predicted shifts in fermentation pathways induced by manipulating the dissolved H2 concentration. A perfusion system is presented that was developed to control dissolved H2 concentrations in the continuous fermentation of glucose by a culture highly enriched towards Thermoanaerobacterium thermosaccharolyticum (86 ± 9% relative abundance) from an originally diverse consortia in the leachate of a laboratory digester fed with municipal solid waste. Media from a 2.5 L CSTR was drawn through sintered steel membrane filters to retain biomass, allowing vigorous sparging in a separate chamber without cellular disruption. Through a combination of sparging and variations in glucose feeding rate from 0.8 to 0.2 g/L/d, a range of steady state fermentations were performed with dissolved H2 concentrations as low as an equivalent equilibrated H2 partial pressure of 3 kPa. Trends in product formation rates were simulated using a H2 regulation partitioning model. The model correctly predicted the direction of products redistribution in response to H2 concentration changes and the acetate and butyrate formation rates when H2 concentrations were less than 6 kPa. However, the model over-estimated acetate, ethanol and butanol productions at the expense of butyrate production at higher H2 concentrations. The H2 yield at the lowest dissolved H2 concentration was 2.67 ± 0.08 mol H2 /mol glucose, over 300% higher than the yield achieved in a CSTR operated without sparging. © 2014 Wiley Periodicals, Inc.

  7. Composition, Reactivity and Regulation of Extracellular Metal-Reducing Structures (Bacterial Nanowires) Produced by Dissimilatory Metal - Reducing Bacteria

    SciTech Connect

    Beveridge, Terrance J.

    2004-06-01

    Approach. Previously, using conventional and cryoTEM techniques, surface physicochemistry assays, NMR structural analysis, etc., we showed that the structure and composition of Shewanella's lipopolysaccharide (LPS) and capsular polysaccharide (PS) significantly determined overall cell surface physicochemistry. In our study a strong correlation between such macroscopic parameters as surface electronegativity, hydrophobicity or hydrophilicity, and bacterial adhesion to hematite was observed. Rough LPS strains exhibited more than an order higher affinity and maximal sorption capacity to hematite when compared to encapsulated strains. These general trends, however, characterize bacterial adhesion only as a bulk process, being unable to reveal finer mechanisms taking place at the level of an individual cell. Cell surface physicochemical and structural heterogeneity suggests much more complex interactions at the bacterial-mineral interface than predicted by such approaches operating within macroscopic parameters.

  8. Characterization of nitrate-reducing and amino acid-using bacteria prominent in nitrotoxin-enriched equine cecal populations

    USDA-ARS?s Scientific Manuscript database

    In the present study, populations of equine cecal microbes enriched for enhanced rates of 3-nitro-1-propionic acid (NPA) or nitrate metabolism were diluted and cultured for NPA-metabolizing bacteria on a basal enrichment medium (BEM) or tryptose soy agar (TSA) medium supplemented with either 5 mM NP...

  9. Comparison of rinsing and sanitizing procedures for reducing bacterial pathogens on fresh cantaloupes and bell peppers.

    PubMed

    Alvarado-Casillas, S; Ibarra-Sánchez, S; Rodríguez-García, O; Martínez-Gonzáles, N; Castillo, A

    2007-03-01

    Increased consumption of fruits and vegetables is linked to health benefits but also to an increase in the number of outbreaks of foodborne illness. To determine the effectiveness of different sanitizing treatments for reducing bacterial pathogens on fresh produce, fresh cantaloupes and bell peppers were harvested and inoculated with suspensions of Salmonella Typhimurium and Escherichia coli O157:H7. The inoculated fruits were treated with water wash alone or were washed and then waxed or rinsed with 200 mg/liter hypochlorite, 10% Ca(OH)2, or 2% lactic acid solutions applied by dipping for 15 s or spraying for 15 s. Preliminary experiments with chlorine treatments indicated that spraying with a 200, 600, or 1,000 mg/liter hypochlorite solution reduced populations of both pathogens by 2.1 to 2.6 and 1.5 to 2.1 log CFU for Salmonella Typhimurium and E. coli O157:H7, respectively. In general, no differences were observed between chlorine solutions without pH adjustment (pH 9.2) and those with pH adjusted to 6.0. When different wash regimes were applied to inoculated cantaloupes or bell peppers, water wash alone produced significantly lower counts of both pathogens on bell peppers in comparison to untreated controls. However, this reduction was not observed on cantaloupes, indicating a possible surface effect. Application of 2% L-lactic acid by spray was the treatment that resulted in the lowest bacterial counts on both cantaloupes and bell peppers. This treatment did not produce any deleterious change in the sensorial characteristics of the products tested. None of the pathogens studied was able to grow during refrigerated storage (5 degrees C for cantaloupes and 10 degrees C for bell peppers), although numbers close to the detection limit of the counting method were found in randomly tested individual samples at days 14 and 28 of storage, indicating that these pathogens can survive for long periods on the produce surface. These results indicate that selected produce

  10. Target Product Profile for a Diagnostic Assay to Differentiate between Bacterial and Non-Bacterial Infections and Reduce Antimicrobial Overuse in Resource-Limited Settings: An Expert Consensus

    PubMed Central

    Dittrich, Sabine; Tadesse, Birkneh Tilahun; Moussy, Francis; Chua, Arlene; Zorzet, Anna; Tängdén, Thomas; Dolinger, David L.; Page, Anne-Laure; Crump, John A.; D’Acremont, Valerie; Bassat, Quique; Lubell, Yoel; Newton, Paul N.; Heinrich, Norbert; Rodwell, Timothy J.; González, Iveth J.

    2016-01-01

    Acute fever is one of the most common presenting symptoms globally. In order to reduce the empiric use of antimicrobial drugs and improve outcomes, it is essential to improve diagnostic capabilities. In the absence of microbiology facilities in low-income settings, an assay to distinguish bacterial from non-bacterial causes would be a critical first step. To ensure that patient and market needs are met, the requirements of such a test should be specified in a target product profile (TPP). To identify minimal/optimal characteristics for a bacterial vs. non-bacterial fever test, experts from academia and international organizations with expertise in infectious diseases, diagnostic test development, laboratory medicine, global health, and health economics were convened. Proposed TPPs were reviewed by this working group, and consensus characteristics were defined. The working group defined non-severely ill, non-malaria infected children as the target population for the desired assay. To provide access to the most patients, the test should be deployable to community health centers and informal health settings, and staff should require <2 days of training to perform the assay. Further, given that the aim is to reduce inappropriate antimicrobial use as well as to deliver appropriate treatment for patients with bacterial infections, the group agreed on minimal diagnostic performance requirements of >90% and >80% for sensitivity and specificity, respectively. Other key characteristics, to account for the challenging environment at which the test is targeted, included: i) time-to-result <10 min (but maximally <2 hrs); ii) storage conditions at 0–40°C, ≤90% non-condensing humidity with a minimal shelf life of 12 months; iii) operational conditions of 5–40°C, ≤90% non-condensing humidity; and iv) minimal sample collection needs (50–100μL, capillary blood). This expert approach to define assay requirements for a bacterial vs. non-bacterial assay should guide

  11. Target Product Profile for a Diagnostic Assay to Differentiate between Bacterial and Non-Bacterial Infections and Reduce Antimicrobial Overuse in Resource-Limited Settings: An Expert Consensus.

    PubMed

    Dittrich, Sabine; Tadesse, Birkneh Tilahun; Moussy, Francis; Chua, Arlene; Zorzet, Anna; Tängdén, Thomas; Dolinger, David L; Page, Anne-Laure; Crump, John A; D'Acremont, Valerie; Bassat, Quique; Lubell, Yoel; Newton, Paul N; Heinrich, Norbert; Rodwell, Timothy J; González, Iveth J

    2016-01-01

    Acute fever is one of the most common presenting symptoms globally. In order to reduce the empiric use of antimicrobial drugs and improve outcomes, it is essential to improve diagnostic capabilities. In the absence of microbiology facilities in low-income settings, an assay to distinguish bacterial from non-bacterial causes would be a critical first step. To ensure that patient and market needs are met, the requirements of such a test should be specified in a target product profile (TPP). To identify minimal/optimal characteristics for a bacterial vs. non-bacterial fever test, experts from academia and international organizations with expertise in infectious diseases, diagnostic test development, laboratory medicine, global health, and health economics were convened. Proposed TPPs were reviewed by this working group, and consensus characteristics were defined. The working group defined non-severely ill, non-malaria infected children as the target population for the desired assay. To provide access to the most patients, the test should be deployable to community health centers and informal health settings, and staff should require <2 days of training to perform the assay. Further, given that the aim is to reduce inappropriate antimicrobial use as well as to deliver appropriate treatment for patients with bacterial infections, the group agreed on minimal diagnostic performance requirements of >90% and >80% for sensitivity and specificity, respectively. Other key characteristics, to account for the challenging environment at which the test is targeted, included: i) time-to-result <10 min (but maximally <2 hrs); ii) storage conditions at 0-40°C, ≤90% non-condensing humidity with a minimal shelf life of 12 months; iii) operational conditions of 5-40°C, ≤90% non-condensing humidity; and iv) minimal sample collection needs (50-100μL, capillary blood). This expert approach to define assay requirements for a bacterial vs. non-bacterial assay should guide product

  12. Thermal compatibility studies of unirradiated uranium silicide dispersed in aluminum. [Reduced Enrichment for Research and Test Reactor

    SciTech Connect

    Wiencek, T.C.; Domagala, R.F.; Thresh, H.R.

    1984-09-01

    Powder metallurgy dispersions of uranium silicides in an aluminum matrix have been developed by the international Reduced Enrichment for Research and Test Reactors program as a new generation of proliferation-resistant fuels. A major issue of concern is the compatibility of the fuel with the matrix material and the dimensional stability of this fuel type. A total of 45 miniplate-type fuel plates were annealed at 400/sup 0/C for up to 1981 hours. A data base for the thermal compatibility of unirradiated uranium silicide dispersed in aluminum was established. No modification tested of a standard fuel plate showed any significant reduction of the plate swelling. The cause of the thermal growth of silicide fuel plates was determined to be a two-step process: (1) the reaction of the uranium silicide with aluminum to form U(AlSi)/sub 3/ and (2) the release of hydrogen and subsequent creep and pillowing of the fuel plate. 9 references, 4 figures, 6 tables.

  13. A reduced cost strategy for enriching chicken meat with omega-3 long chain polyunsaturated fatty acids using dietary flaxseed oil.

    PubMed

    Kanakri, K; Carragher, J; Hughes, R; Muhlhausler, B; Gibson, R

    2017-06-01

    1. This study aimed to determine the minimal duration required for feeding male broilers (Cobb 500) with a flaxseed oil diet while still retaining long chain omega-3 polyunsaturated fatty acid (n-3 LCPUFA) accumulation in the meat at a desirable level. 2. Three groups of broilers (60 each) were fed on a 3% flaxseed oil (high α-linolenic acid (ALA)) diet for either 6, 4 or 2 weeks prior to slaughter. During the remaining time they were maintained on a 3% macadamia oil (low ALA) diet. A fourth group (control, n = 60) was fed on a commercial diet for 6 weeks. 3. No significant difference was observed in growth performance of broilers between groups. The amounts of total n-3 and n-3 LCPUFA in breast and thigh meat were not different between broilers fed the flaxseed oil diet for 4 and 6 weeks, but they were lower (P < 0.001) in those fed the flaxseed diet for only 2 weeks. 4. These results suggest comparable levels of n-3 LCPUFA in the meat can be achieved by only feeding the flaxseed oil diet in the last 3-4 weeks of the growth period; this would result in a ≥ 9.4% reduction in the use of flaxseed oil compared to 6 weeks of feeding; thereby reducing the cost of the enrichment process.

  14. Immunoglobulin M-enriched intravenous polyclonal immunoglobulins reduce bacteremia following Klebsiella pneumoniae infection in an acute respiratory distress syndrome rat model.

    PubMed

    Lachmann, R A; van Kaam, A H L C; Haitsma, J J; Verbrugge, S J C; Delreu, F; Lachmann, B

    2004-06-01

    Mechanical ventilation is known to induce bacterial translocation from the lung into the systemic circulation. This study determined the effect of immunoglobulin M (IgM)-enriched polyclonal immunoglobulins on bacteremia due to ventilation-induced translocation in an acute respiratory distress syndrome (ARDS) rat model with Klebsiella-induced pneumonia. After whole lung lavage, Sprague-Dawley rats intravenously received either a high dose or a low dose of an immunoglobulin preparation, or an albumin solution as control, followed by an intratracheal injection of a Klebsiella pneumoniae solution. Blood colony-forming units (CFUs) in the treatment groups were significantly lower during the 3-hour ventilation period compared to the control group. The authors conclude that IgM-enriched polyclonal immunoglobulins lead to a reduction of bacteria in blood of surfactant-deficient, ventilated rats infected with Klebsiella pneumoniae.

  15. Mosapride Stabilizes Intestinal Microbiota to Reduce Bacterial Translocation and Endotoxemia in CCl4-Induced Cirrhotic Rats.

    PubMed

    Xu, Hong; Xiong, Jingfang; Xu, Jianjun; Li, Shuiming; Zhou, Yang; Chen, Dongya; Cai, Xinjun; Ping, Jian; Deng, Min; Chen, Jianyong

    2017-08-16

    Impaired intestinal motility may lead to the disruption of gut microbiota equilibrium, which in turn facilitates bacterial translocation (BT) and endotoxemia in cirrhosis. We evaluated the influence of mosapride, a prokinetic agent, on BT and DNA fingerprints of gut microbiota in cirrhotic rats. A rat model of cirrhosis was set up via subcutaneous injection of carbon tetrachloride (CCl4). The portal pressure, liver and intestinal damage, plasma endotoxin, BT, and intestinal transit rate (ITR) of cirrhotic rats were determined. Fecal DNA fingerprints were obtained by ERIC-PCR. The expressions of tight junction proteins were evaluated by western blotting. Mosapride treatment to cirrhotic rats significantly reduced the plasma endotoxin level and incidence of BT, accompanied by increased ITR. Cirrhotic rats (including those treated with mosapride) suffered from BT exhibited significantly lower ITR than those who are free of BT. Pearson coefficient indicated a significant and negative correlation between the plasma endotoxin level and ITR. The genomic fingerprints of intestinal microbiota from the three groups fell into three distinctive clusters. In the mosapride-treated group, Shannon's index was remarkably increased compared to the model group. Significantly positive correlation was detected between Shannon's index and ITR. Mosapride did not improve hepatic and intestinal damages and ileal expressions of occludin and ZO-1. Mosapride significantly increases intestinal motility in cirrhotic rats, thus to recover the disordered intestinal microbiota, finally resulting in decreased plasma endotoxin and BT.

  16. Microstructured liposome subunit vaccines reduce lung inflammation and bacterial load after Mycobacterium tuberculosis infection.

    PubMed

    Trentini, Monalisa Martins; de Oliveira, Fábio Muniz; Gaeti, Marilisa Pedroso Nogueira; Batista, Aline Carvalho; Lima, Eliana Martins; Kipnis, André; Junqueira-Kipnis, Ana Paula

    2014-07-23

    Tuberculosis is a disease affecting millions of people throughout the world. One of the main problems in controlling the disease is the low efficacy of the Bacillus Calmette-Guérin (BCG) vaccine in protecting young adults. The development of new vaccines that induce a long-lasting immune response or that stimulate the immunity induced by BCG may improve the control of tuberculosis. The use of microstructured liposomes containing HspX, with or without MPL or CpG DNA adjuvants, as vaccines for tuberculosis was evaluated. The HspX-specific humoral and cellular immune responses to the different vaccine formulations were compared. All vaccines containing liposome microparticles and HspX were immunogenic. Vaccines formulated with CpG DNA and HspX induced the strongest humoral and cellular immune responses, mainly by inducing interferon-γ and tumor necrosis factor-α expression by both CD4(+) and CD8(+) T cells. HspX and MPL mainly induced CD8(+) T-cell activation and specific humoral responses. When evaluated the protective efficacy of the formulations against Mycobacterium tuberculosis challenge, the microstructured liposome containing L-HspX and L-HspX-CPG DNA reduced both lung inflammatory lesions and the bacterial load. We have thus demonstrated, for the first time, the use of microstructured liposomes as an adjuvant and delivery system for a vaccine formulation against tuberculosis. Copyright © 2014 Elsevier Ltd. All rights reserved.

  17. The metabolism of neonicotinoid insecticide thiamethoxam by soil enrichment cultures, and the bacterial diversity and plant growth-promoting properties of the cultured isolates.

    PubMed

    Zhou, Guang-Can; Wang, Ying; Ma, Yuan; Zhai, Shan; Zhou, Ling-Yan; Dai, Yi-Jun; Yuan, Sheng

    2014-01-01

    A soil enrichment culture (SEC) rapidly degraded 96% of 200 mg L(-1) neonicotinoid insecticide thiamethoxam (TMX) in MSM broth within 30 d; therefore, its metabolic pathway of TMX, bacterial diversity and plant growth-promoting rhizobacteria (PGPR) activities of the cultured isolates were studied. The SEC transformed TMX via the nitro reduction pathway to form nitrso, urea metabolites and via cleavage of the oxadiazine cycle to form a new metabolite, hydroxyl CLO-tri. In addition, 16S rRNA gene-denaturing gradient gel electrophoresis analysis revealed that uncultured rhizobacteria are predominant in the SEC broth and that 77.8% of the identified bacteria belonged to uncultured bacteria. A total of 31 cultured bacterial strains including six genera (Achromobacter, Agromyces, Ensifer, Mesorhizobium, Microbacterium and Pseudoxanthomonas) were isolated from the SEC broth. The 12 strains of Ensifer adhaerens have the ability to degrade TMX. All six selected bacteria showed PGPR activities. E. adhaerens TMX-23 and Agromyces mediolanus TMX-25 produced indole-3-acetic acid, whereas E. adhaerens TMX-23 and Mesorhizobium alhagi TMX-36 are N2-fixing bacteria. The six-isolated microbes were tolerant to 200 mg L(-1) TMX, and the growth of E. adhaerens was significantly enhanced by TMX, whereas that of Achromobacter sp. TMX-5 and Microbacterium sp.TMX-6 were enhanced slightly. The present study will help to explain the fate of TMX in the environment and its microbial degradation mechanism, as well as to facilitate future investigations of the mechanism through which TMX enhances plant vigor.

  18. Effects of chromium-enriched bacillus subtilis KT260179 supplementation on chicken growth performance, plasma lipid parameters, tissue chromium levels, cecal bacterial composition and breast meat quality.

    PubMed

    Yang, Jiajun; Qian, Kun; Zhang, Wei; Xu, Yayuan; Wu, Yijing

    2016-11-08

    Both chromium (Cr) and probiotic bacillus own the virtues of regulating animal metabolism and meat quality. Purpose of this study was to evaluate the efficiency of supplemental Cr and bacillus in the form of chromium-enriched Bacillus subtilis KT260179 (CEBS) on chicken growth performance, plasma lipid parameters, tissue chromium levels, cecal bacterial composition and breast meat quality. Six hundred of 1-day-old Chinese Huainan Partridge chickens were divided into four groups randomly: Control, inorganic Cr, Bacillus subtilis, and CEBS. The feed duration was 56 days. After 28 days of treatment, broiler feed CEBS or normal B. subtilis had higher body weights than control broiler, and after 56 days, chickens given either CEBS or B. subtilis had greater body weights than control broiler or those given inorganic Cr. Plasma total cholesterol, triglycerides, and low density lipoprotein cholesterol levels declined significantly in the CEBS group compared with the control, whereas plasma high density lipoprotein cholesterol levels increased significantly. The concentration of Cr in blood and breast muscle increased after CEBS and inorganic Cr supplementation. B. subtilis and CEBS supplementation caused a significant increase in the numbers of Lactobacillus and Bifidobacterium in the caecum, while the numbers of Escherichia coli and Salmonella decreased significantly compared to the control. Feed adding CEBS increased the lightness, redness, and yellowness of breast meat, improved the water-holding capacity, decreased the shear force and cooking loss. In all, CEBS supplementation promoted body growth, improved plasma lipid parameters, increased tissue Cr concentrations, altered cecal bacterial composition and improved breast meat quality.

  19. The effectiveness of peppermint and thyme essential oil mist in reducing bacterial contamination in broiler houses.

    PubMed

    Witkowska, D; Sowinska, J

    2013-11-01

    The antimicrobial properties of essential oils have been demonstrated by various in vitro studies, whereas their effect on poultry farm hygiene has not been thoroughly investigated, in particular with reference to aerial treatment. The present study aims to assess the antibacterial effects of natural essential oils in broiler houses. Two experimental rooms were fogged with aqueous solutions of peppermint and thyme oils. The control room was sprayed with pure water. The experiment was conducted on broilers aged 1 to 42 d. The rooms were fogged every 3 d. One day after fogging, the total counts of mesophilic aerobic bacteria, Enterobacteriaceae, and mannitol-positive staphylococci were determined. Samples were collected from the air, litter, walls, and drinkers. The results of the study demonstrate that essential oil mist may improve hygiene standards in broiler farms. During broiler growth, the mean total counts of mesophilic bacteria in the rooms treated with essential oils were lower (P < 0.01 or P < 0.05) in comparison with the control. Enterobacteriaceae and staphylococci counts were also higher in the control group. A single exception was noted in a litter sample where the mean count of Enterobacteriaceae in the room fogged with peppermint oil was higher than in the control. Both oils reduced bacterial counts, but thyme oil was more effective in reducing coliform bacteria, whereas peppermint oil had a higher inhibitory effect on the proliferation of staphylococci. These promising results encourage further research to determine the optimal doses and the effects of essential oils and their combinations on the living conditions and health status of broiler chickens.

  20. An enriched environment reduces the stress level and locomotor activity induced by acute morphine treatment and by saline after chronic morphine treatment in mice.

    PubMed

    Xu, Jia; Sun, Jinling; Xue, Zhaoxia; Li, Xinwang

    2014-06-18

    This study investigated the relationships among an enriched environment, stress levels, and drug addiction. Mice were divided randomly into four treatment groups (n=12 each): enriched environment without restraint stress (EN), standard environment without restraint stress (SN), enriched environment with restraint stress (ES), and standard environment with restraint stress (SS). Mice were reared in the respective environment for 45 days. Then, the ES and SS groups were subjected to restraint stress daily (2 h/day) for 14 days, whereas the EN and SN groups were not subjected to restraint stress during this stage. The stress levels of all mice were tested in the elevated plus maze immediately after exposure to restraint stress. After the 2-week stress testing period, mice were administered acute or chronic morphine (5 mg/kg) treatment for 7 days. Then, after a 7-day withdrawal period, the mice were injected with saline (1 ml/kg) or morphine (5 mg/kg) daily for 2 days to observe locomotor activity. The results indicated that the enriched environment reduced the stress and locomotor activity induced by acute morphine administration or saline after chronic morphine treatment. However, the enriched environment did not significantly inhibit locomotor activity induced by morphine challenge. In addition, the stress level did not mediate the effect of the enriched environment on drug-induced locomotor activity after acute or chronic morphine treatment.

  1. Spatial and temporal changes in sulphate-reducing groundwater bacterial community structure in response to Managed Aquifer Recharge.

    PubMed

    Reed, D A; Toze, S; Chang, B

    2008-01-01

    The population dynamics of bacterial able to be cultured under sulphate reducing condition was studied in conjunction with changes in aquifer geochemistry using multivariate statistics for two contrasting Managed Aquifer Recharge (MAR) techniques at two different geographical locations (Perth, Western Australia and Adelaide, South Australia). Principal component analysis (PCA) was used to investigate spatial and temporal changes in the overall chemical signature of the aquifers using an array of chemical analytes which demonstrated a migrating geochemical plume. Denaturing Gradient Gel Electrophoresis (DGGE) using DNA from sulphate-reducing bacteria cultures was used to detect spatial and temporal changes in population dynamics. Bacterial and geochemical evidence suggested that groundwater at greatest distance from the nutrient source was least affected by treated effluent recharge. The results suggested that bacterial populations that were able to be cultured in sulphate reducing media responded to the migrating chemical gradient and to the changes in aquifer geochemistry. Most noticeably, sulphate-reducing bacterial populations associated with the infiltration galleries were stable in community structure over time. Additionally, the biodiversity of these culturable bacteria was restored when aquifer geochemistry returned to ambient conditions during the recovery phase at the Adelaide Aquifer Storage and Recovery site.

  2. EFFECT OF PRE-EVISCERATION, SKIN-ON CARCASS DECONTAMINATION SANITATION STRATEGIES FOR REDUCING BACTERIAL CONTAMINATION OF BEEF DURING SKINNING

    USDA-ARS?s Scientific Manuscript database

    The effectiveness of pre-evisceration, skin-on carcass sanitation on reducing bacterial contamination of beef carcasses was tested using 3 cattle per treatment and 3 cattle as controls at each of 3 abattoirs in southern Wisconsin. The sanitation procedure included stunning, bleeding, tying off the e...

  3. Reduced electrical performance of Zn enriched ZnTe nanoinclusion semiconductors thin films for buffer layer in solar cells

    NASA Astrophysics Data System (ADS)

    Mahmood, Waqar; Thomas, Andrew; Haq, Anwar ul; Shah, Nazar Abbas; Farooq Nasir, Muhammad

    2017-06-01

    Closed space sublimation (CSS) technique was employed to deposit thin films of zinc telluride (ZnTe) on a glass substrate under high vacuum. Two sets of ZnTe thin films and Zn enriched ZnTe thin films were prepared for comparative study. The enrichment for Zn onto the as-deposited ZnTe thin films was done by the novel manner of layer by layer deposition with subsequent annealing. X-ray diffraction (XRD) studies revealed before and after the enrichment of Zn the preferred orientation is [1 1 1] having cubic phase. The lattice constant was found to be increased and the crystallite size decreased 28 nm to 24 nm after the enrichment of Zn. A morphological study was carried out through a scanning electron microscope (SEM). For Zn enriched samples the average grain size is smaller as compared to ZnTe thin films. The local compositions of Zn and Te were confirmed by energy dispersive x-rays (EDX) from 51 atomic % of as-deposited ZnTe thin films to 68 atomic % in Zn enriched ZnTe thin films. The Zn enriched samples have a slight decrease in optical transmission in UV-VIS-NIR range as compared to the as-deposited ZnTe thin films. Due to the deposition of Zn there is a very small change in optical band gap energy. A four-probe technique was used to study electrical properties of as-deposited and Zn-enriched ZnTe thin films. These results shows that the as-deposited samples had the resistivity of 106 Ω · cm. For Zn enrichment samples resistivity increases from 106 Ω · cm to 108 Ω · cm, which shows that Zn-enriched samples are not suitable for back contact of II-VI solar cells. X-rays photoelectron spectroscopy (XPS) was used to confirm the elemental compositions and its bonding strength before and after the enrichment of Zn.

  4. A More Reduced Mantle Source for Enriched Shergottites; Insights from the Olivine-Phyric Shergottite Lar 06319

    NASA Technical Reports Server (NTRS)

    Peslier, A. H.; Hnatyshin, D.; Herd, C. D. K.; Walton, E. L.; Brandon, A. D.; Lapen, T. J.; Shafer, J.

    2010-01-01

    A detailed petrographic study of melt inclusions and Cr-Fe-Ti oxides of LAR 06319 leads to two main conclusions: 1) this enriched oxidized olivine- phyric shergottite represents nearly continuous crystallization of a basaltic shergottite melt, 2) the melt became more oxidized during differentiation. The first crystallized mineral assemblages record the oxygen fugacity which is closest to that of the melt s mantle source, and which is lower than generally attributed to the enriched shergottite group.

  5. An alum-based water treatment residual can reduce extractable phosphorus concentrations in three phosphorus-enriched coastal plain soils.

    PubMed

    Novak, J M; Watts, D W

    2005-01-01

    The accumulation of excess soil phosphorus (P) in watersheds under intensive animal production has been linked to increases in dissolved P concentrations in rivers and streams draining these watersheds. Reductions in water dissolved P concentrations through very strong P sorption reactions may be obtainable after land application of alum-based drinking water treatment residuals (WTRs). Our objectives were to (i) evaluate the ability of an alum-based WTR to reduce Mehlich-3 phosphorus (M3P) and water-soluble phosphorus (WSP) concentrations in three P-enriched Coastal Plain soils, (ii) estimate WTR application rates necessary to lower soil M3P levels to a target 150 mg kg(-1) soil M3P concentration threshold level, and (iii) determine the effects on soil pH and electrical conductivity (EC). Three soils containing elevated M3P (145-371 mg kg(-1)) and WSP (12.3-23.5 mg kg(-1)) concentrations were laboratory incubated with between 0 and 6% WTR (w w(-1)) for 84 d. Incorporation of WTR into the three soils caused a near linear and significant reduction in soil M3P and WSP concentrations. In two soils, 6% WTR application caused a soil M3P concentration decrease to below the soil P threshold level. An additional incubation on the third soil using higher WTR to soil treatments (10-15%) was required to reduce the mean soil M3P concentration to 178 mg kg(-1). After incubation, most treatments had less than a half pH unit decline and a slight increase in soil EC values suggesting a minimal impact on soil quality properties. The results showed that WTR incorporation into soils with high P concentrations caused larger relative reductions in extractable WSP than M3P concentrations. The larger relative reductions in the extractable WSP fraction suggest that WTR can be more effective at reducing potential runoff P losses than usage as an amendment to lower M3P concentrations.

  6. Combined effects of enrichment procedure and non-fermentable or fermentable co-substrate on performance and bacterial community for pentachlorophenol degradation in microbial fuel cells.

    PubMed

    Wang, Shanshan; Huang, Liping; Gan, Linlin; Quan, Xie; Li, Ning; Chen, Guohua; Lu, Lu; Xing, Defeng; Yang, Fenglin

    2012-09-01

    Combined effects of enrichment procedure and non-fermentable acetate or fermentable glucose on system performance and bacterial community for pentachlorophenol (PCP) degradation in microbial fuel cells (MFCs) were determined in this study. Co-substrate and PCP were added into MFCs either simultaneously or sequentially. Simultaneous addition with glucose (simultaneous-glucose) achieved the shortest acclimation time and the most endurance to heavy PCP shock loads. Species of Alphaproteobacteria (simultaneous-acetate, 33.9%; sequential-acetate, 31.3%), Gammaproteobacteria (simultaneous-glucose, 44.1%) and Firmicutes (sequential-glucose, 31.8%) dominated the complex systems. The genus Sedimentibacter was found to exist in all the cases whereas Spirochaetes were merely developed in simultaneous-acetate and simultaneous-glucose. While Epsilonproteobacteria were only absent from sequential-acetate, simultaneous-glucose benefited to the evolution of Lentisphaerae. These results demonstrate simultaneous-glucose is a strategy for efficient system performance and the microbiological evidence can contribute to improving understanding of and optimizing PCP degradation in MFCs. Copyright © 2012 Elsevier Ltd. All rights reserved.

  7. Glucomannan or Glucomannan Plus Spirulina-Enriched Squid-Surimi Diets Reduce Histological Damage to Liver and Heart in Zucker fa/fa Rats Fed a Cholesterol-Enriched and Non-Cholesterol-Enriched Atherogenic Diet.

    PubMed

    Vázquez-Velasco, Miguel; González-Torres, Laura; García-Fernández, Rosa A; Méndez, María Teresa; Bastida, Sara; Benedí, Juana; González-Muñoz, María José; Sánchez-Muniz, Francisco J

    2017-06-01

    Glucomannan-enriched squid surimi improves cholesterolemia and liver antioxidant status. The effect of squid surimi enriched with glucomannan or glucomannan plus spirulina on liver and heart structures and cell damage markers was tested in fa/fa rats fed highly saturated-hyper-energetic diets. Animals were fed 70% AIN-93M rodent diet plus six versions of 30% squid surimi for 7 weeks: control (C), glucomannan (G), and glucomannan plus spirulina (GS). The cholesterol-control (HC), cholesterol-glucomannan (HG), and cholesterol-glucomannan plus spirulina (HGS) groups were given similar diets that were enriched with 2% cholesterol and 0.4% cholic acid. G and GS diets versus C diet significantly inhibited weight gain and lowered plasma alanine aminotransferase and aspartate aminotransferase, liver steatosis, lipogranulomas, and total inflammation and alteration scores. The hypercholesterolemic agent significantly increased the harmful effects of the C diet. Liver weight, the hepatosomatic index, all damage markers, and total histological scoring rose for HC versus C (at least P < .05). The addition of glucomannan (HG vs. HC) improved these biomarkers, and non-additional effects from spirulina were observed except for the total liver alteration score. In conclusion, glucomannan and glucomannan plus spirulina blocked the highly saturated-hyper-energetic diet negative effects both with and without added cholesterol. Results suggest the usefulness of including these functional ingredients in fish products.

  8. Chlorinated phenol treatment and in situ hydrogen peroxide production in a sulfate-reducing bacteria enriched bioelectrochemical system.

    PubMed

    Miran, Waheed; Nawaz, Mohsin; Jang, Jiseon; Lee, Dae Sung

    2017-04-05

    Wastewaters are increasingly being considered as renewable resources for the sustainable production of electricity, fuels, and chemicals. In recent years, bioelectrochemical treatment has come to light as a prospective technology for the production of energy from wastewaters. In this study, a bioelectrochemical system (BES) enriched with sulfate-reducing bacteria (SRB) in the anodic chamber was proposed and evaluated for the biodegradation of recalcitrant chlorinated phenol, electricity generation (in the microbial fuel cell (MFC)), and production of hydrogen peroxide (H2O2) (in the microbial electrolysis cell (MEC)), which is a very strong oxidizing agent and often used for the degradation of complex organics. Maximum power generation of 253.5 mW/m(2), corresponding to a current density of 712.0 mA/m(2), was achieved in the presence of a chlorinated phenol pollutant (4-chlorophenol (4-CP) at 100 mg/L (0.78 mM)) and lactate (COD of 500 mg/L). In the anodic chamber, biodegradation of 4-CP was not limited to dechlorination, and further degradation of one of its metabolic products (phenol) was observed. In MEC operation mode, external voltage (0.2, 0.4, or 0.6 V) was added via a power supply, with 0.4 V producing the highest concentration of H2O2 (13.3 g/L-m(2) or 974 μM) in the cathodic chamber after 6 h of operation. Consequently, SRB-based bioelectrochemical technology can be applied for chlorinated pollutant biodegradation in the anodic chamber and either net current or H2O2 production in the cathodic chamber by applying an optimum external voltage.

  9. Comparison of different washing treatments for reducing pathogens on orange surfaces and for preventing the transfer of bacterial pathogens to fresh-squeezed orange juice.

    PubMed

    Martínez-Gonzáles, N E; Martínez-Chávez, L; Martínez-Cárdenas, C; Castillo, A

    2011-10-01

    The objectives of this study were to compare the effectiveness of various washing treatments for reducing Escherichia coli O157:H7, Salmonella sp., and Listeria monocytogenes populations on orange surfaces and to measure the effect of some of these treatments in preventing the transfer of pathogens during juice extraction. Orange surfaces inoculated with L. monocytogenes or a mixture of E. coli O157:H7 and Salmonella Typhimurium were washed by water spray and then sprayed with or dipped in water at 80°C for 1 min, 70% ethanol for 15, 30, or 45 s or 1, 2, or 4 min, 2 or 4% lactic acid solution at 55°C for 15, 30, or 45 s or 1, 2, or 4 min, or 200 mg/liter hypochlorite at pH 6.5 or 10 for 15 s. The surviving populations of these pathogens on the oranges were enumerated after each treatment. In a further stage, the ability of these pathogens to be transferred to the juice during extraction was tested. Juice was obtained from inoculated oranges that were subjected to selected treatments using chlorine, lactic acid, ethanol, and hot water as described above, and then bacterial counts in orange juice were determined. The application of these treatments reduced the populations of pathogens on orange surfaces by 1.9 to >4.9 log, 1.9 to >4.6 log, and 1.4 to 3.1 log cycles for E. coli O157:H7, Salmonella Typhimurium, and L. monocytogenes, respectively. The treatments using hot water or lactic acid showed greater reductions than other treatments. The time, antimicrobial concentration, and form of application affected the bacterial reduction. All treatments resulted in undetectable counts in the juice. Nevertheless, pathogens were recovered by the enrichment-plating method. Treatment of oranges before juice extraction may reduce the risk associated with consuming orange juice.

  10. Bacterial Infection of Fly Ovaries Reduces Egg Production and Induces Local Hemocyte Activation

    PubMed Central

    Brandt, Stephanie M.; Schneider, David S.

    2009-01-01

    Summary Morbidity, the state of being diseased, is an important aspect of pathogenesis that has gone relatively unstudied in fruit flies. Our interest is in characterizing how bacterial pathogenesis affects various physiologies of the fly. We chose to examine the fly ovary because we found bacterial infection had a striking effect on fly reproduction. We observed decreased egg laying after bacterial infection that correlated with increased bacterial virulence. We also found that bacteria colonized the ovary in a previously undescribed manner; bacteria were found in the posterior of the ovary, adjacent to the lateral oviduct. This local infection in the ovary resulted in melanization and activation of the cellular immune response at the site of infection. PMID:17400292

  11. Methylmercury decomposition in sediments and bacterial cultures: Involvement of methanogens and sulfate reducers in oxidative demethylation

    USGS Publications Warehouse

    Oremland, R.S.; Culbertson, C.W.; Winfrey, M.R.

    1991-01-01

    Demethylation of monomethylmercury in freshwater and estuarine sediments and in bacterial cultures was investigated with 14CH3HgI. Under anaerobiosis, results with inhibitors indicated partial involvement of both sulfate reducers and methanogens, the former dominating estuarine sediments, while both were active in freshwaters. Aerobes were the most significant demethylators in estuarine sediments, but were unimportant in freshwater sediments. Products of anaerobic demethylation were mainly 14CO2 as well as lesser amounts of 14CH4. Acetogenic activity resulted in fixation of some 14CO2 produced from 14CH3HgI into acetate. Aerobic demethylation in estuarine sediments produced only 14CH4, while aerobic demethylation in freshwater sediments produced small amounts of both 14CH4 and 14CO2. Two species of Desulfovibrio produced only traces of 14CH4 from 14CH3HgI, while a culture of a methylotrophic methanogen formed traces of 14CO2 and 14CH4 when grown on trimethylamine in the presence of the 14CH3HgI. These results indicate that both aerobes and anaerobes demethylate mercury in sediments, but that either group may dominate in a particular sediment type. Aerobic demethylation in the estuarine sediments appeared to proceed by the previously characterized organomercurial-lyase pathway, because methane was the sole product. However, aerobic demethylation in freshwater sediments as well as anaerobic demethylation in all sediments studied produced primarily carbon dioxide. This indicates the presence of an oxidative pathway, possibly one in which methylmercury serves as an analog of one-carbon substrates.

  12. Methylmercury decomposition in sediments and bacterial cultures: Involvement of methanogens and sulfate reducers in oxidative demethylation

    SciTech Connect

    Oremland, R.S.; Culbertson, C.W. ); Winfrey, M.R. )

    1991-01-01

    The biogeochemical cycling of mercury has received considerable attention because of the toxicity of methylmercury, its bioaccumulation in biota, and its biomagnification in aquatic food chains. The formation of methylmercury is mediated primarily by microorganisms. Demethylation of monomethylmercury in freshwater and estuarine sediments and in bacterial cultures was investigated with {sup 14}CH{sub 3}HgI. Under anaerobiosis, results with inhibitors indicated partial involvement of both sulfate reducers and methanogens, the former dominated estuarine sediments, while both were active in freshwaters. Aerobes were the most significant demethylators in estuarine sediments, but were unimportant in freshwater sediments. Products of anaerobic demthylation were mainly {sup 14}CO{sub 2} as well as lesser amounts of {sup 14}CH{sub 4}. Acetogenic activity resulted in fixation of some {sup 14}CO{sub 2} produced from {sup 14}CH{sub 3}HgI into acetate. Aerobic demethylation in estuarine sediments produced only {sup 14}CH{sub 4}, while aerobic demethylation in freshwater sediments produced small amounts of both {sup 14}CH{sub 4} and {sup 14}CO{sub 2}. Two species of Desulfovibrio produced only traces of {sup 14}CH{sub 4} from {sup 14}CH{sub 3}HgI, while a culture of a methylotrophic methanogen formed traces of {sup 14}CO{sub 2} and {sup 14}CH{sub 4} when grown on trimethylamine in the presence of the {sup 14}CH{sub 3}HgI. These results indicate that both aerobes and anaerobes demethylate mercury in sediments, but that either group may dominate in a particular sediment type. Aerobic demethylation in the estuarine sediments appeared to proceed by the previously characterized organomercurial-lyase pathway, because methane was the sole product. This indicates the presence of an oxidative pathway, possibly one in which methylmercury serves as an analog of one-carbon substrates.

  13. Can dressings soaked with polyhexanide reduce bacterial loads in full-thickness skin grafting? A randomized controlled trial.

    PubMed

    Saleh, Karim; Sonesson, Andreas; Persson, Kerstin; Riesbeck, Kristian; Schmidtchen, Artur

    2016-12-01

    Polyhexamethylene biguanide (PHMB)-based antiseptic solutions can reduce bacterial loads in different clinical settings and are believed to lower risk of infections. We sought to assess the efficacy of a PHMB-based solution in lowering bacterial loads of full-thickness skin grafting wounds and the risk of surgical site infections (SSIs). In this double-blinded clinical trial, 40 patients planned for facial full-thickness skin grafting were randomized 1:1 to receive tie-over dressings soaked with either PHMB-based solution or sterile water. Quantitative and qualitative bacterial analysis was performed on all wounds before surgery, at the end of surgery, and 7 days postoperatively. In addition, all patients were screened for nasal colonization of Staphylococcus aureus. Analysis of wounds showed no statistically significant difference in bacterial reductions between the groups. The SSI rates were significantly higher in the intervention group (8/20) than in the control group (2/20) (P = .028). Higher postoperative bacterial loads were a common finding in SSIs (P = .011). This was more frequent when S aureus was present postoperatively (P = .034), intraoperatively (P = .03), and in patients with intranasal S aureus colonization (P = .007). Assessment of SSIs is largely subjective. In addition, this was a single-center study and the total number of participants was 40. Soaking tie-over dressings with PHMB solution in full-thickness skin grafting had no effect on postoperative bacterial loads and increased the risk of SSI development. The presence of S aureus intranasally and in wounds preoperatively and postoperatively increased postoperative bacterial loads, which in turn resulted in significantly more SSIs. Copyright © 2016 American Academy of Dermatology, Inc. Published by Elsevier Inc. All rights reserved.

  14. The use of a solid adsorber resin for enrichment of bacteria with toxic substrates and to identify metabolites: degradation of naphthalene, O-, and m-xylene by sulfate-reducing bacteria.

    PubMed

    Morasch, B; Annweiler, E; Warthmann, R J; Meckenstock, R U

    2001-03-01

    Anaerobic sulfate-reducing bacteria were enriched from contaminated aquifer samples with naphthalene, o-, and m-xylene as sole carbon and energy source in the presence of Amberlite-XAD7, a solid adsorber resin. XAD7 served as a substrate reservoir maintaining a constantly low substrate concentration in the culture medium. In equilibration experiments with XAD7, the aromatic hydrocarbons needed up to 5 days to achieve equilibrium between the water and the XAD7 phase. The equilibrium concentration was directly correlated with the amount of added substrate and XAD7. In the enrichments presented here, XAD7 and aromatic hydrocarbons were adjusted to maintain substrate concentrations of 100 microM m-, or o-xylene, or 50 microM naphthalene. After five subsequent transfers, the three cultures were able to grow with higher substrate concentrations in the absence of XAD7 although they grew best with lower hydrocarbon concentrations. Two new xylene-degrading cultures were obtained that could not utilise toluene as carbon source. O-xylene was degraded anaerobically by a culture, which could also oxidise m-xylene but not p-xylene. Eighty-three percent of the electrons from o-xylene oxidation were recovered in the produced sulfide, indicating a complete oxidation to CO2. Another sulfate-reducing enrichment culture oxidised m-xylene completely to CO2 but not o-, or p-xylene. A naphthalene-degrading sulfate-reducing enrichment culture oxidised naphthalene completely to CO2. Metabolites of naphthalene degradation were recovered from the XAD7 phase and subjected to GC/MS analysis. Besides the metabolites 2-naphthoic acid and decahydro-2-naphthoic acid which were identified by the mass spectrum and coelution with chemically synthesised reference compounds, the reduced 2-naphthoic acid derivatives 5,6,7,8-tetrahydro-2-naphthoic acid and octahydro-2-naphthoic acid were tentatively identified by their mass spectra. Cultivation of bacterial cultures in the presence of XAD7 and subsequent

  15. Efficacy of sanitized ice in reducing bacterial load on fish fillet and in the water collected from the melted ice.

    PubMed

    Feliciano, Lizanel; Lee, Jaesung; Lopes, John A; Pascall, Melvin A

    2010-05-01

    This study investigated the efficacy of sanitized ice for the reduction of bacteria in the water collected from the ice that melted during storage of whole and filleted Tilapia fish. Also, bacterial reductions on the fish fillets were investigated. The sanitized ice was prepared by freezing solutions of PRO-SAN (an organic acid formulation) and neutral electrolyzed water (NEW). For the whole fish study, the survival of the natural microflora was determined from the water of the melted ice prepared with PRO-SAN and tap water. These water samples were collected during an 8 h storage period. For the fish fillet study, samples were inoculated with Escherichia coli K12, Listeria innocua, and Pseudomonas putida then stored on crushed sanitized ice. The efficacies of these were tested by enumerating each bacterial species on the fish fillet and in the water samples at 12 and 24 h intervals for 72 h, respectively. Results showed that each bacterial population was reduced during the test. However, a bacterial reduction of < 1 log CFU was obtained for the fillet samples. A maximum of approximately 2 log CFU and > 3 log CFU reductions were obtained in the waters sampled after the storage of whole fish and the fillets, respectively. These reductions were significantly (P < 0.05) higher in the water from sanitized ice when compared with the water from the unsanitized melted ice. These results showed that the organic acid formulation and NEW considerably reduced the bacterial numbers in the melted ice and thus reduced the potential for cross-contamination.

  16. Transferring whole genomes from bacteria to yeast spheroplasts using entire bacterial cells to reduce DNA shearing.

    PubMed

    Karas, Bogumil J; Jablanovic, Jelena; Irvine, Edward; Sun, Lijie; Ma, Li; Weyman, Philip D; Gibson, Daniel G; Glass, John I; Venter, J Craig; Hutchison, Clyde A; Smith, Hamilton O; Suzuki, Yo

    2014-04-01

    Direct cell-to-cell transfer of genomes from bacteria to yeast facilitates genome engineering for bacteria that are not amenable to genetic manipulation by allowing instead for the utilization of the powerful yeast genetic tools. Here we describe a protocol for transferring whole genomes from bacterial cells to yeast spheroplasts without any DNA purification process. The method is dependent on the treatment of the bacterial and yeast cellular mixture with PEG, which induces cell fusion, engulfment, aggregation or lysis. Over 80% of the bacterial genomes transferred in this way are complete, on the basis of structural and functional tests. Excluding the time required for preparing starting cultures and for incubating cells to form final colonies, the protocol can be completed in 3 h.

  17. Development of a risk reduction intervention to reduce bacterial and viral infections for injection drug users

    PubMed Central

    Phillips, Kristina T.; Altman, Jennifer K.; Corsi, Karen F.; Stein, Michael D.

    2016-01-01

    Bacterial infections are widespread problems among drug injectors, requiring novel preventive intervention. As part of a NIDA-funded study, we developed an intervention based on the Information-Motivation-Behavioral Skills Model, past research, injection hygiene protocols, and data collected from focus groups with 32 injectors in Denver in 2009. Qualitative responses from focus groups indicated that most participants had experienced skin abscesses and believed that bacterial infections were commonly a result of drug cut, injecting intramuscularly, and reusing needles. Access to injection supplies and experiencing withdrawal were the most frequently reported barriers to utilizing risk reduction. Implications for intervention development are discussed. PMID:23017057

  18. Anterior thalamic lesions reduce spine density in both hippocampal CA1 and retrosplenial cortex, but enrichment rescues CA1 spines only.

    PubMed

    Harland, Bruce C; Collings, David A; McNaughton, Neil; Abraham, Wickliffe C; Dalrymple-Alford, John C

    2014-10-01

    Injury to the anterior thalamic nuclei (ATN) may affect both hippocampus and retrosplenial cortex thus explaining some parallels between diencephalic and medial temporal lobe amnesias. We found that standard-housed rats with ATN lesions, compared with standard-housed controls, showed reduced spine density in hippocampal CA1 neurons (basal dendrites, -11.2%; apical dendrites, -9.6%) and in retrospenial granular b cortex (Rgb) neurons (apical dendrites, -20.1%) together with spatial memory deficits on cross maze and radial-arm maze tasks. Additional rats with ATN lesions were also shown to display a severe deficit on spatial working memory in the cross-maze, but subsequent enriched housing ameliorated their performance on both this task and the radial-arm maze. These enriched rats with ATN lesions also showed recovery of both basal and apical CA1 spine density to levels comparable to that of the standard-housed controls, but no recovery of Rgb spine density. Inspection of spine types in the CA1 neurons showed that ATN lesions reduced the density of thin spines and mushroom spines, but not stubby spines; while enrichment promoted recovery of thin spines. Comparison with enriched rats that received pseudo-training, which provided comparable task-related experience, but no explicit spatial memory training, suggested that basal CA1 spine density in particular was associated with spatial learning and memory performance. Distal pathology in terms of reduced integrity of hippocampal and retrosplenial microstructure provides clear support for the influence of the ATN lesions on the extended hippocampal system. The reversal by postoperative enrichment of this deficit in the hippocampus but not the retrosplenial cortex may indicate region-specific mechanisms of recovery after ATN injury. © 2014 Wiley Periodicals, Inc.

  19. Enrichment of provitamin A content in wheat (Triticum aestivum L.) by introduction of the bacterial carotenoid biosynthetic genes CrtB and CrtI

    PubMed Central

    Wang, Cheng; Zeng, Jian; Li, Yin; Yang, Guangxiao; He, Guangyuan

    2014-01-01

    Carotenoid content is a primary determinant of wheat nutritional value and affects its end-use quality. Wheat grains contain very low carotenoid levels and trace amounts of provitamin A content. In order to enrich the carotenoid content in wheat grains, the bacterial phytoene synthase gene (CrtB) and carotene desaturase gene (CrtI) were transformed into the common wheat cultivar Bobwhite. Expression of CrtB or CrtI alone slightly increased the carotenoid content in the grains of transgenic wheat, while co-expression of both genes resulted in a darker red/yellow grain phenotype, accompanied by a total carotenoid content increase of approximately 8-fold achieving 4.76 μg g–1 of seed dry weight, a β-carotene increase of 65-fold to 3.21 μg g–1 of seed dry weight, and a provitamin A content (sum of α-carotene, β-carotene, and β-cryptoxanthin) increase of 76-fold to 3.82 μg g–1 of seed dry weight. The high provitamin A content in the transgenic wheat was stably inherited over four generations. Quantitative PCR analysis revealed that enhancement of provitamin A content in transgenic wheat was also a result of the highly coordinated regulation of endogenous carotenoid biosynthetic genes, suggesting a metabolic feedback regulation in the wheat carotenoid biosynthetic pathway. These transgenic wheat lines are not only valuable for breeding wheat varieties with nutritional benefits for human health but also for understanding the mechanism regulating carotenoid biosynthesis in wheat endosperm. PMID:24692648

  20. Enrichment of provitamin A content in wheat (Triticum aestivum L.) by introduction of the bacterial carotenoid biosynthetic genes CrtB and CrtI.

    PubMed

    Wang, Cheng; Zeng, Jian; Li, Yin; Hu, Wei; Chen, Ling; Miao, Yingjie; Deng, Pengyi; Yuan, Cuihong; Ma, Cheng; Chen, Xi; Zang, Mingli; Wang, Qiong; Li, Kexiu; Chang, Junli; Wang, Yuesheng; Yang, Guangxiao; He, Guangyuan

    2014-06-01

    Carotenoid content is a primary determinant of wheat nutritional value and affects its end-use quality. Wheat grains contain very low carotenoid levels and trace amounts of provitamin A content. In order to enrich the carotenoid content in wheat grains, the bacterial phytoene synthase gene (CrtB) and carotene desaturase gene (CrtI) were transformed into the common wheat cultivar Bobwhite. Expression of CrtB or CrtI alone slightly increased the carotenoid content in the grains of transgenic wheat, while co-expression of both genes resulted in a darker red/yellow grain phenotype, accompanied by a total carotenoid content increase of approximately 8-fold achieving 4.76 μg g(-1) of seed dry weight, a β-carotene increase of 65-fold to 3.21 μg g(-1) of seed dry weight, and a provitamin A content (sum of α-carotene, β-carotene, and β-cryptoxanthin) increase of 76-fold to 3.82 μg g(-1) of seed dry weight. The high provitamin A content in the transgenic wheat was stably inherited over four generations. Quantitative PCR analysis revealed that enhancement of provitamin A content in transgenic wheat was also a result of the highly coordinated regulation of endogenous carotenoid biosynthetic genes, suggesting a metabolic feedback regulation in the wheat carotenoid biosynthetic pathway. These transgenic wheat lines are not only valuable for breeding wheat varieties with nutritional benefits for human health but also for understanding the mechanism regulating carotenoid biosynthesis in wheat endosperm.

  1. How fitness reduced, antimicrobial resistant bacteria survive and spread: a multiple pig-multiple bacterial strain model.

    PubMed

    Græsbøll, Kaare; Nielsen, Søren Saxmose; Toft, Nils; Christiansen, Lasse Engbo

    2014-01-01

    More than 30% of E. coli strains sampled from pig farms in Denmark over the last five years were resistant to the commonly used antimicrobial tetracycline. This raises a number of questions: How is this high level sustained if resistant bacteria have reduced growth rates? Given that there are multiple susceptible and resistant bacterial strains in the pig intestines, how can we describe their coexistence? To what extent does the composition of these multiple strains in individual pigs influence the total bacterial population of the pig pen? What happens to a complex population when antimicrobials are used? To investigate these questions, we created a model where multiple strains of bacteria coexist in the intestines of pigs sharing a pen, and explored the parameter limits of a stable system; both with and without an antimicrobial treatment. The approach taken is a deterministic bacterial population model with stochastic elements of bacterial distributions and transmission. The rates that govern the model are process-oriented to represent growth, excretion, and uptake from environment, independent of herd and meta-population structures. Furthermore, an entry barrier and elimination process for the individual strains in each pig were implemented. We demonstrate how competitive growth between multiple bacterial strains in individual pigs, and the transmission between pigs in a pen allow for strains of antimicrobial resistant bacteria to persist in a pig population to different extents, and how quickly they can become dominant if antimicrobial treatment is initiated. The level of spread depends in a non-linear way of the parameters that govern excretion and uptake. Furthermore, the sampling of initial distributions of strains and stochastic transmission events give rise to large variation in how homogenous and how resistant the bacterial population becomes. Most important: resistant bacteria are demonstrated to survive with a disadvantage in growth rate of well over 10%.

  2. Assessing the utility of ultraviolet irradiation to reduce bacterial biofilms in fish hatchery well water supplies

    USDA-ARS?s Scientific Manuscript database

    The accumulation of bacterial biofilms and consequent clogging of screens, pipes, and heat exchanger equipment is problematic for water supply systems contaminated with iron bacteria and other slime forming bacteria. Despite the ubiquitous threat posed by iron bacteria contamination in groundwater s...

  3. Increased Bacterial Load and Expression of Antimicrobial Peptides in Skin of Barrier-Deficient Mice with Reduced Cancer Susceptibility

    PubMed Central

    Natsuga, Ken; Cipolat, Sara; Watt, Fiona M.

    2016-01-01

    Mice lacking three epidermal barrier proteins—envoplakin, periplakin, and involucrin (EPI-/- mice)—have a defective cornified layer, reduced epidermal γδ T cells, and increased dermal CD4+ T cells. They are also resistant to developing skin tumors. The tumor-protective mechanism involves signaling between Rae-1 expressing keratinocytes and the natural killer group 2D receptor on immune cells, which also plays a role in host defenses against infection. Given the emerging link between bacteria and cancer, we investigated whether EPI-/- mice have an altered skin microbiota. The bacterial phyla were similar in wild-type and EPI-/- skin. However, bacteria were threefold more abundant in EPI-/- skin and penetrated deeper into the epidermis. The major epithelial defense mechanism against bacteria is production of antimicrobial proteins (AMPs). EPI-/- skin exhibited enhanced expression of antimicrobial peptides. However, reducing the bacterial load by antibiotic treatment or breeding mice under specific pathogen-free conditions did not reduce AMP expression or alleviate the abnormalities in T-cell populations. We conclude that the atopic characteristics of EPI-/- skin are a consequence of the defective barrier rather than a response to the increased bacterial load. It is therefore unlikely that the increase in skin microbiota contributes directly to the observed cancer resistance. PMID:26763429

  4. Increased Bacterial Load and Expression of Antimicrobial Peptides in Skin of Barrier-Deficient Mice with Reduced Cancer Susceptibility.

    PubMed

    Natsuga, Ken; Cipolat, Sara; Watt, Fiona M

    2016-01-01

    Mice lacking three epidermal barrier proteins-envoplakin, periplakin, and involucrin (EPI-/- mice)-have a defective cornified layer, reduced epidermal γδ T cells, and increased dermal CD4(+) T cells. They are also resistant to developing skin tumors. The tumor-protective mechanism involves signaling between Rae-1 expressing keratinocytes and the natural killer group 2D receptor on immune cells, which also plays a role in host defenses against infection. Given the emerging link between bacteria and cancer, we investigated whether EPI-/- mice have an altered skin microbiota. The bacterial phyla were similar in wild-type and EPI-/- skin. However, bacteria were threefold more abundant in EPI-/- skin and penetrated deeper into the epidermis. The major epithelial defense mechanism against bacteria is production of antimicrobial proteins (AMPs). EPI-/- skin exhibited enhanced expression of antimicrobial peptides. However, reducing the bacterial load by antibiotic treatment or breeding mice under specific pathogen-free conditions did not reduce AMP expression or alleviate the abnormalities in T-cell populations. We conclude that the atopic characteristics of EPI-/- skin are a consequence of the defective barrier rather than a response to the increased bacterial load. It is therefore unlikely that the increase in skin microbiota contributes directly to the observed cancer resistance. Copyright © 2015 The Authors. Published by Elsevier Inc. All rights reserved.

  5. Intestinal REG3 Lectins Protect Against Alcoholic Steatohepatitis by Reducing Mucosa-Associated Microbiota and Preventing Bacterial Translocation

    PubMed Central

    Wang, Lirui; Fouts, Derrick E.; Stärkel, Peter; Hartmann, Phillipp; Chen, Peng; Llorente, Cristina; DePew, Jessica; Moncera, Kelvin; Ho, Samuel B.; Brenner, David A.; Hooper, Lora V.; Schnabl, Bernd

    2016-01-01

    Summary Approximately half of all deaths from liver cirrhosis, the 10th leading cause of mortality in the United States, are related to alcohol use. Chronic alcohol consumption is accompanied by intestinal dysbiosis and bacterial overgrowth, yet little is known about the factors that alter the microbial composition or their contribution to liver disease. We previously associated chronic alcohol consumption with lower intestinal levels of the antimicrobial-regenerating islet-derived (REG)-3 lectins. Here, we demonstrate that intestinal deficiency in REG3B or REG3G increases numbers of mucosa-associated bacteria and enhances bacterial translocation to the mesenteric lymph nodes and liver, promoting the progression of ethanol-induced fatty liver disease toward steatohepatitis. Overexpression of Reg3g in intestinal epithelial cells restricts bacterial colonization of mucosal surfaces, reduces bacterial translocation, and protects mice from alcohol-induced steatohepatitis. Thus, alcohol appears to impair control of the mucosa-associated microbiota, and subsequent breach of the mucosal barrier facilitates progression of alcoholic liver disease. PMID:26867181

  6. Wastewater treatment effluent reduces the abundance and diversity of benthic bacterial communities in urban and suburban rivers.

    PubMed

    Drury, Bradley; Rosi-Marshall, Emma; Kelly, John J

    2013-03-01

    In highly urbanized areas, wastewater treatment plant (WWTP) effluent can represent a significant component of freshwater ecosystems. As it is impossible for the composition of WWTP effluent to match the composition of the receiving system, the potential exists for effluent to significantly impact the chemical and biological characteristics of the receiving ecosystem. We assessed the impacts of WWTP effluent on the size, activity, and composition of benthic microbial communities by comparing two distinct field sites in the Chicago metropolitan region: a highly urbanized river receiving effluent from a large WWTP and a suburban river receiving effluent from a much smaller WWTP. At sites upstream of effluent input, the urban and suburban rivers differed significantly in chemical characteristics and in the composition of their sediment bacterial communities. Although effluent resulted in significant increases in inorganic nutrients in both rivers, surprisingly, it also resulted in significant decreases in the population size and diversity of sediment bacterial communities. Tag pyrosequencing of bacterial 16S rRNA genes revealed significant effects of effluent on sediment bacterial community composition in both rivers, including decreases in abundances of Deltaproteobacteria, Desulfococcus, Dechloromonas, and Chloroflexi sequences and increases in abundances of Nitrospirae and Sphingobacteriales sequences. The overall effect of the WWTP inputs was that the two rivers, which were distinct in chemical and biological properties upstream of the WWTPs, were almost indistinguishable downstream. These results suggest that WWTP effluent has the potential to reduce the natural variability that exists among river ecosystems and indicate that WWTP effluent may contribute to biotic homogenization.

  7. Formula fortified with live probiotic culture reduces pulmonary and gastrointestinal bacterial colonization and translocation in a newborn animal model.

    PubMed

    McVay, Marcene R; Boneti, Cristiano; Habib, Christine M; Keller, Jennifer E; Kokoska, Evan R; Jackson, Richard J; Smith, Samuel D

    2008-01-01

    Acidified diets are protective against intestinal bacterial colonization and translocation. Probiotic diets are designed to modulate the intestinal flora to enhance mucosal immunity. This study was designed to determine if formula acidified with live probiotic decreases bacterial gut colonization and translocation, and is equally tolerated as other acidified diets. One hundred twenty-eight rabbit pups delivered via cesarean section [cesarean delivery, cesarean birth, abdominal delivery] were randomly assigned to 4 feeding groups: NAN Nestle (control, pH 7.0), NAN acidified with citric acid (pH 4.55), biologically acidified Pelargon (pH 4.55), and NAN with live Lactococcus lactis culture (pH 4.2). Pups were gavage fed every 12 hours with Enterobacter cloacae challenges of 10 colony-forming units/mL per feed and killed on day of life 3. Lungs, liver, spleen, mesenteric lymph nodes (MLNs), stomach, and cecum were cultured and quantitatively analyzed for target organism growth. Results were analyzed using chi(2) tests. NAN with live probiotic culture, when compared with Pelargon, acidified NAN, and NAN, significantly reduced the incidence of Enterobacter pulmonary colonization (P < .01), bacterial translocation (liver, P < .025; spleen and MLN, P < .05), and gastric and intestinal colonization (P < .001 for both). Probiotic-fortified formula provides superior protection against pulmonary and gastrointestinal bacterial colonization and translocation compared with neutral and acidified formulas, and is equally tolerated.

  8. Stimulation of Strontium Accumulation in Linoleate-Enriched Saccharomyces cerevisiae Is a Result of Reduced Sr2+ Efflux

    PubMed Central

    Avery, Simon V.; Smith, Shareeka L.; Ghazi, A. Mohamad; Hoptroff, Michael J.

    1999-01-01

    The influence of modified plasma membrane fatty acid composition on cellular strontium accumulation in Saccharomyces cerevisiae was investigated. Growth of S. cerevisiae in the presence of 1 mM linoleate (18:2) (which results in 18:2 incorporation to ∼70% of total cellular and plasma membrane fatty acids, with no effect on growth rate) yielded cells that accumulated Sr2+ intracellularly at approximately twice the rate of S. cerevisiae grown without a fatty acid supplement. This effect was evident over a wide range of external Sr2+ concentrations (25 μM to 5 mM) and increased with the extent of cellular 18:2 incorporation. Stimulation of Sr2+ accumulation was not evident following enrichment of S. cerevisiae with either palmitoleate (16:1), linolenate (18:3) (n-3 and n-6 isomers), or eicosadienoate (20:2) (n-6 and n-9 isomers). Competition experiments revealed that Ca2+- and Mg2+-induced inhibition of Sr2+ accumulation did not differ between unsupplemented and 18:2-supplemented cells. Treatment with trifluoperazine (TFP) (which can act as a calmodulin antagonist and Ca2+-ATPase inhibitor), at a low concentration that precluded nonspecific K+ efflux, increased intracellular Sr2+ accumulation by approximately 3.6- and 1.4-fold in unsupplemented and 18:2-supplemented cells, respectively. Thus, TFP abolished the enhanced Sr2+ accumulation ability of 18:2-supplemented cells. Moreover, the rate of Sr2+ release from Sr2+-loaded fatty acid-unsupplemented cells was found to be at least twice as great as that from Sr2+-loaded 18:2-enriched cells. The influence of enrichment with other fatty acids on Sr2+ efflux was variable. The results reveal an enhanced Sr2+ accumulation ability of S. cerevisiae following 18:2-enrichment, which is attributed to diminished Sr2+ efflux activity in these cells. PMID:10049882

  9. Stimulation of strontium accumulation in linoleate-enriched Saacharomyces cerevisiae is a result of reduced Sr{sup 2+} efflux

    SciTech Connect

    Avery, S.V.; Smith, S.L.; Ghazi, A.M.; Hoptroff, M.J.

    1999-03-01

    The influence of modified plasma membrane fatty acid composition on cellular strontium accumulation in Saccharomyces cerevisiae was investigated. Growth of S. cerevisiae in the presence of 1 mM linoleate (18:2) yielded cells that accumulated Sr{sup 2+} intracellularly at approximately twice the rate of S. cerevisiae grown without a fatty acid supplement. This effect was evident over a wide range of external Sr{sup 2+} concentrations and increased with the extent of cellular 18:2 incorporation. Stimulation of Sr{sup 2+} accumulation was not evident following enrichment of S. cerevisiae with either palmitoleate (16:1), linolenate (18:3) (n-3 and n-6 isomers), or eicosadienoate (20:2) (n-6 and n-9 isomers). Competition experiments revealed that Ca{sup 2+}- and Mg{sup 2+}-induced inhibition of Sr{sup 2+} accumulation did not differ between unsupplemented and 18:2-supplemented cells. Treatment with trifluoperazine (TFP) (which can act as a calmodulin antagonist and Ca{sup 2+}-ATPase inhibitor), at a low concentration that precluded nonspecific K{sup +} efflux, increased intracellular Sr{sup 2+} accumulation by approximately 3.6- and 1.4-fold in unsupplemented and 18:2-supplemented cells, respectively. Thus, TFP abolished the enhanced Sr{sup 2+} accumulation ability of 18:2 supplemented cells. Moreover, the rate of Sr{sup 2+} release from Sr{sup 2+}-loaded fatty acid-unsupplemented cells was found to be at least twice as great as that from Sr{sup 2+}-loaded 18:2-enriched cells. The influence of enrichment with other fatty acids on Sr{sup 2+} efflux was variable. The results reveal an enhanced Sr{sup 2+} accumulation ability of S. cerevisiae following 18:2-enrichment, which is attributed to diminished Sr{sup 2+} efflux activity in these cells.

  10. Reduced cortisol in the absence of bacterial infection in patients with hepatitis B virus cirrhosis.

    PubMed

    Zhang, J; Yu, H-W; Li, J; Zhu, Y-K; Wang, K-F; Jia, L; Meng, Q-H

    2015-07-17

    In liver cirrhosis with bacterial infection, hepatoadrenal syndrome has been described recently as a progressive impairment in the adrenocortical reserve, with deficient production or action of glucocorticoids resulting in adrenal insufficiency. The aim of this study was to explore the characteristics of cortisol in hepatitis B virus (HBV) cirrhosis patients in the absence of bacterial infection. Fasting peripheral venous blood samples were collected from 107 patients with HBV cirrhosis in the absence of bacterial infection and 18 patients with chronic hepatitis B (CHB) infection at 7 a.m. in the morning. The carbohydrate, cortisol-binding globulin, routine chemistry, liver function, and hepatitis B indicators were tested, and free cortisol was calculated. Cortisol (COR) levels were 18.72 ± 6.60 μg/dL in the CHB group and 14.20 ± 7.55 μg/dL in the HBV cirrhosis group (P = 0.002). COR levels were 15.11 ± 5.56, 14.88 ± 6.96, and 12.68 ± 8.36 μg/dL in Child-Pugh class A, B, and C cirrhotic patients, respectively (P = 0.006). Adrenocorticotropic hormone levels were 35.42 ± 24.49, 26.57 ± 15.72, and 19.65 ± 10.72 pg/mL in Child-Pugh class A, B, and C cirrhotic patients, respectively (P = 0.000). Patients with HBV cirrhosis had significantly lower serum COR levels compared with those of CHB patients, even if they are in the absence of bacterial infection. COR levels negatively correlated with Child-Pugh scores. The hypothalamic-pituitary-adrenal axis might be damaged in patients with HBV cirrhosis.

  11. Ethosomal Curcumin Promoted Wound Healing and Reduced Bacterial Flora in Second Degree Burn in Rat.

    PubMed

    Partoazar, A; Kianvash, N; Darvishi, M H; Nasoohi, S; Rezayat, S M; Bahador, A

    2016-12-01

    Background: Curcumin is well known in biomedical investigations with an extensive antimicrobial properties and wound repair effect. However, clinical criteria recommend curcumin should be formulated for topical medication. Material and method: In this study, we prepared Ethosomal curcumin (Etho-cur) formulation for wound healing and bacterial flora assessments in treated rats which were subjected to second degree burn under a standard procedure. Results: Applying once daily of Etho-cur (0.2%) topically on rat's dorsal for 14 days significantly recovered main aspects of wound repair including re-epithelization (P<0.01), neovascularization (P<0.01), collagen synthesis (P<0.001), granulation tissue formation (P<0.001) compared with control. Considerable wound contraction was occurred by Etho-cur treatment sooner than other groups and after 16 days it was completed with a significant (P<0.001) value. Furthermore, ethosomal formulation of curcumin similar to silver sulfadiazine (SSD) cream 1% potentially inhibited (P<0.001) growth of the burn bacterial flora including Pseudomonas aeruginosa as predominant bacteria among experimental isolations during 14 days treatment. Also, antibacterial activity of Etho-cur was estimated approximately 11% more potent than free curcumin in reduction of the burn bacterial flora. Conclusion: Regarding the results, ethosomal curcumin efficiently fights against wound infection and promotes wound repair in burn injuries in rats. © Georg Thieme Verlag KG Stuttgart · New York.

  12. [NO3-/NO2- inhibits sulfate-reducing activity of the enrichment culture of sulfate-reducing prokaryotes from an off-shore oil reservoir at Bohai Bay, China].

    PubMed

    Liu, Hong-Yu; Shi, Rong-Jiu; Zhang, Ying; Shi, Zhen-Guo; Zhang, Ying-Yue; Yu, Liang; Zhang, Xiao-Bo; Tan, Tao

    2014-08-01

    Long-term injection of sulfate-rich water into oil reservoirs stimulates the proliferation of sulfate-reducing prokaryotes (SRP) therein and results in production of a great amount of H2S, leading to souring in oil reservoirs and related environmental problems. In this study, we first, using modified API RP 38 medium, enriched SRP present in production water from a producing well at Bohai Bay, China, and then examined the inhibitory effects of nitrate or nitrite on sulfate reduction activity of the SRP. Results showed that the enriched SRP culture exhibited a high sulfate reduction activity as indicated by a sulfate-reducing rate of 10.4 mmol SO4(2-) x d(-1) x g(-1) dry cell. In presence of 0.4, 0.8, 1.8, and 4.2 mmol x L(-1) nitrate, sulfate reduction was inhibited for 5, 9, 20, and over 35 days, respectively. With the addition of 0.6, 0.9, 1.4, 2.6 and 4.6 mmol x L(-1) of nitrite, the inhibitory period lasted 3, 12, 22, and over 39 days, respectively. The SRP enrichment culture could dissimilatorily reduce nitrate to ammonium. When sulfate, nitrate and nitrite coexisted, nitrate or nitrite was preferentially used over sulfate as electron acceptor by the enriched SRP. This competitive use of electron acceptor and the strong inhibitory effect of nitrite possibly accounted for the suppression of nitrate and nitrite on the sulfate-reducing activity of the enriched SRP cultures from offshore oil reservoir at Bohai Bay.

  13. Distribution and diversity of bacterial communities and sulphate-reducing bacteria in a paddy soil irrigated with acid mine drainage.

    PubMed

    Wang, H; Guo, C L; Yang, C F; Lu, G N; Chen, M Q; Dang, Z

    2016-07-01

    To investigate the effects of long-term acid mine drainage (AMD) irrigation on the change in bacterial community and sulphate-reducing bacteria (SRB) in a paddy soil. The bacterial community structures were investigated using 454 pyrosequencing, and 98 931 effective sequences were selected for the bacterial diversity analysis. The known dominant phyla in the paddy soil were Acidobacteria (33·5%), Proteobacteria (19·7%), Nitrospira (2·8%) and Actinobacteria (2·7%). Higher percentage of Acidobacteria than Proteobacteria was detected. The relative abundances of the dominant bacterial lineages were more significantly correlated with the soil pH, the organic matter and the sulphate than the heavy metals. The diversity of the SRB in the surface paddy soil showed that the uncultured SRB groups might play important roles in paddy soils. The other OTUs mainly belonged to six phylogenetic divisions: Desulfobacca, Desulfovibrio, Syntrophobacter, Desulforhopalus, Desulfarculus and Desulfobulbus. The distribution of the absolute abundance and the relative contribution of the SRB along the vertical soil profile were investigated by RT-PCR assays based on the dsrB gene. The abundance of the dsrB gene copy numbers was up to 1·92 × 10(9)  copies g(-1) dry soil, which is slightly higher than the other non-AMD-affected paddy soil. This study demonstrated that the abundance of SRB is increased by the AMD irrigation while changing the composition and diversity of the bacterial community in the paddy soil. This is, to our knowledge, the first attempt to characterize and quantify changes in the diversity and distribution of the microbial community and SRB in the long-term AMD-irrigated paddy soil, which will further increase our understanding of the impact of AMD on sulphur biogeochemical cycling in the paddy soil. © 2016 The Society for Applied Microbiology.

  14. French invasive Asian tiger mosquito populations harbor reduced bacterial microbiota and genetic diversity compared to Vietnamese autochthonous relatives

    PubMed Central

    Minard, G.; Tran, F. H.; Van, Van Tran; Goubert, C.; Bellet, C.; Lambert, G.; Kim, Khanh Ly Huynh; Thuy, Trang Huynh Thi; Mavingui, P.; Valiente Moro, C.

    2015-01-01

    The Asian tiger mosquito Aedes albopictus is one of the most significant pathogen vectors of the twenty-first century. Originating from Asia, it has invaded a wide range of eco-climatic regions worldwide. The insect-associated microbiota is now recognized to play a significant role in host biology. While genetic diversity bottlenecks are known to result from biological invasions, the resulting shifts in host-associated microbiota diversity has not been thoroughly investigated. To address this subject, we compared four autochthonous Ae. albopictus populations in Vietnam, the native area of Ae. albopictus, and three populations recently introduced to Metropolitan France, with the aim of documenting whether these populations display differences in host genotype and bacterial microbiota. Population-level genetic diversity (microsatellite markers and COI haplotype) and bacterial diversity (16S rDNA metabarcoding) were compared between field-caught mosquitoes. Bacterial microbiota from the whole insect bodies were largely dominated by Wolbachia pipientis. Targeted analysis of the gut microbiota revealed a greater bacterial diversity in which a fraction was common between French and Vietnamese populations. The genus Dysgonomonas was the most prevalent and abundant across all studied populations. Overall genetic diversities of both hosts and bacterial microbiota were significantly reduced in recently established populations of France compared to the autochthonous populations of Vietnam. These results open up many important avenues of investigation in order to link the process of geographical invasion to shifts in commensal and symbiotic microbiome communities, as such shifts may have dramatic impacts on the biology and/or vector competence of invading hematophagous insects. PMID:26441903

  15. [Experience of using bacteriophages and bitsillin-5 to reduce the incidence of respiratory diseases of bacterial ethiology in military personnel].

    PubMed

    Akimkin, V G; Kalmykov, A A; Aminev, R M; Polyakov, V S; Artebyakin, S V

    2016-02-01

    The authors defined epidemiological efficacy and safety of the use of bacteriophages(streptococcal, staphylococcal, piobakferiophage multipartial) and bitsillin-5 to reduce tonsillitis morbidityand other respiratory diseases with bacterial etiology in groups of servicemen during their formationagainst increase of seasonal morbidity. The results of the use of these preventive agents were evaluatedby a comparative analysis of this disease in experimental and control groups. In total 510 healthy conscriptswere involved into the study. The effectiveness of prophylactic use of bacteriophages and bitsillin-5, whichprovided a reduction in the incidence of respiratory infections of bacterial ethiology, tonsillitis, and otherrespiratory diseases is showed. Recommendations on the choice of drugsfor the prevention of these infections,methods and organization of their application in organized groups are given.

  16. Glibenclamide reduces pro-inflammatory cytokine production by neutrophils of diabetes patients in response to bacterial infection

    NASA Astrophysics Data System (ADS)

    Kewcharoenwong, Chidchamai; Rinchai, Darawan; Utispan, Kusumawadee; Suwannasaen, Duangchan; Bancroft, Gregory J.; Ato, Manabu; Lertmemongkolchai, Ganjana

    2013-11-01

    Type 2 diabetes mellitus is a major risk factor for melioidosis, which is caused by Burkholderia pseudomallei. Our previous study has shown that polymorphonuclear neutrophils (PMNs) from diabetic subjects exhibited decreased functions in response to B. pseudomallei. Here we investigated the mechanisms regulating cytokine secretion of PMNs from diabetic patients which might contribute to patient susceptibility to bacterial infections. Purified PMNs from diabetic patients who had been treated with glibenclamide (an ATP-sensitive potassium channel blocker for anti-diabetes therapy), showed reduction of interleukin (IL)-1β and IL-8 secretion when exposed to B. pseudomallei. Additionally, reduction of these pro-inflammatory cytokines occurred when PMNs from diabetic patients were treated in vitro with glibenclamide. These findings suggest that glibenclamide might be responsible for the increased susceptibility of diabetic patients, with poor glycemic control, to bacterial infections as a result of its effect on reducing IL-1β production by PMNs.

  17. An investigation of the physiology and potential role of components of the deep ocean bacterial community (of the NE Atlantic) by enrichments carried out under minimal environmental change

    NASA Astrophysics Data System (ADS)

    Egan, Simon T.; McCarthy, David M.; Patching, John W.; Fleming, Gerard T. A.

    2012-03-01

    Samples of deep-ocean water (3170 m) taken from the Rockall Trough (North-East Atlantic) were incubated for one-month at atmospheric and in-situ pressure (31 MPa), at 4 °C and in the absence and presence of added nutrients. Prokaryotic abundance (direct cell counts) increased by at least 28-fold in enrichments without added nutrients. However, the magnitude of increase in abundance was less for incubations carried out at in-situ pressure (131-181-fold) than those incubations at surface pressure (163-1714-fold increase in abundance). Changes in the prokaryotic community profile as a result of one-month incubation were measured by means of Denaturing Gel Electrophoresis (DGGE) of extracted 16S rDNA. The profiles of post-incubation samples incubated at in-situ pressure were separated from all other profiles as were those of unpressurised samples with added nutrients. The behaviour (fitness) of individual community members (Operational Taxonomic Units: OTUs) was determined on the basis of change in relative DGGE band intensities between pre- and post-incubation samples. Of twenty-one OTUs examined, six were fitter when incubated in the presence of added nutrients and at in-situ pressure and one of these was advantaged when grown in the absence of added nutrients and at in-situ pressure. These represented autochthonous and active members of the deep-ocean prokaryotic community. In contrast, seven OTUs were disadvantaged when grown under in-situ pressure and were indicative surface-derived allochtonous microorganisms. A further two OTUs came to dominance in incubations with added nutrients (pressurised and unpressurised) and similar to the previous category were probably surface-derived microorganisms. A single OTU showed characteristics of piezophilic and oliogrophic behaviour and four OTUs were disadvantaged under all incubation conditions examined. The twenty-one DGGE bands were sequenced and the bacterial communities were dominated by Gamma proteobactria and to a

  18. Optimization of niosomes for enhanced antibacterial activity and reduced bacterial resistance: in vitro and in vivo evaluation.

    PubMed

    Abdelaziz, Ahmed A; Elbanna, Tarek E; Sonbol, Fatma I; Gamaleldin, Noha M; El Maghraby, Gamal M

    2015-02-01

    The aim was to optimize norfloxacin niosomes for enhanced antibacterial activity and reduced bacterial resistance. Pseudomonas aeruginosa, a biofilm forming bacterium, was used as the test organism. Different norfloxacin niosomes were evaluated in vitro and in vivo, respectively, for antibacterial activity compared with aqueous drug solution. The influence of norfloxacin niosomes on biofilm formation was investigated. The interaction of niosomes with bacterial cells was also monitored using the scanning electron microscopy (SEM). The efficacy of niosomes depended on their composition. Standard niosomes of Span 60 and cholesterol were similar to drug solution. Incorporation of Tween 80, oleic acid (OA), OA/propylene glycol or lecithin produced fluid niosomes which reduced the MIC and inhibited biofilm formation compared with drug solution. Incorporation of a positively charged agent into fluid niosomes enhanced the antibacterial activity and reduced biofilm formation significantly. SEM showed evidence of vesicle adsorption to the bacteria with possible adhesion or fusion with the cell membrane. The in vivo skin model confirmed the in vitro results with optimum niosomes being more efficient than drug solution. Niosomes are promising for enhanced antibacterial activity and reduced resistance to antibiotics. The later can be achieved by inhibition of biofilm formation.

  19. Interleukin-22 reduces lung inflammation during influenza A virus infection and protects against secondary bacterial infection.

    PubMed

    Ivanov, Stoyan; Renneson, Joelle; Fontaine, Josette; Barthelemy, Adeline; Paget, Christophe; Fernandez, Elodie Macho; Blanc, Fany; De Trez, Carl; Van Maele, Laurye; Dumoutier, Laure; Huerre, Michel-René; Eberl, Gérard; Si-Tahar, Mustapha; Gosset, Pierre; Renauld, Jean Christophe; Sirard, Jean Claude; Faveeuw, Christelle; Trottein, François

    2013-06-01

    Interleukin-22 (IL-22) has redundant, protective, or pathogenic functions during autoimmune, inflammatory, and infectious diseases. Here, we addressed the potential role of IL-22 in host defense and pathogenesis during lethal and sublethal respiratory H3N2 influenza A virus (IAV) infection. We show that IL-22, as well as factors associated with its production, are expressed in the lung tissue during the early phases of IAV infection. Our data indicate that retinoic acid receptor-related orphan receptor-γt (RORγt)-positive αβ and γδ T cells, as well as innate lymphoid cells, expressed enhanced Il22 transcripts as early as 2 days postinfection. During lethal or sublethal IAV infections, endogenous IL-22 played no role in the control of IAV replication and in the development of the IAV-specific CD8(+) T cell response. During lethal infection, where wild-type (WT) mice succumbed to severe pneumonia, the lack of IL-22 did not accelerate or delay IAV-associated pathogenesis and animal death. In stark contrast, during sublethal IAV infection, IL-22-deficient animals had enhanced lung injuries and showed a lower airway epithelial integrity relative to WT littermates. Of importance, the protective effect of endogenous IL-22 in pulmonary damages was associated with a more controlled secondary bacterial infection. Indeed, after challenge with Streptococcus pneumoniae, IAV-experienced Il22(-/-) animals were more susceptible than WT controls in terms of survival rate and bacterial burden in the lungs. Together, IL-22 plays no major role during lethal influenza but is beneficial during sublethal H3N2 IAV infection, where it limits lung inflammation and subsequent bacterial superinfections.

  20. [Efficacy of five disinfectants to reduce bacterial load in the household].

    PubMed

    Stambullian, Julián; Rossotti, Daniel; Fridman, Diego; Luchetti, Pablo; Cheade, Yamila; Stamboulian, Daniel

    2011-01-01

    The proper use of products containing sodium hypochlorite,ammonium salts and triclosan has proved to be effective in the elimination of infectious agents in the household environment. Our objective was to evaluate the immediate, one-week and one-month efficacy of controlled use of five products containing these components, compared to other commonly used products. Within a six month period, thirty two middle-class homes from Buenos Aires City and suburbs were included in this open-label, randomized, parallel-group intervention study. Sixteen homes were randomized to use products containing sodium hypochlorite, ammonia and triclosan in the kitchen and bathroom during one month. The remaining maintained usual practices for domestic cleaning. Bacterial counts and identification were performed from samples taken from each study site. Baseline samples (no group discrimination) contained a mean bacterial count in kitchen of 66.0 CFU/cm2, and in bathroom 40.1 CFU/cm2. Samples taken immediately after-cleaning (no group discrimination) contained: kitchen 0.8 CFU/cm2; bathroom < 1 CFU/cm2. After one week (intervention group vs. control group) contained: kitchen 18.0 vs. 32.5 CFU/cm2; bathroom 12.7 vs. 7.7 CFU/cm2. After one month (intervention group vs. control group): kitchen 60.1 vs. 62.1 CFU/cm2; bathroom 37.0 vs. 42.0 CFU/cm2. A remarkable decrease of bacterial load was observed in both groups, which suggests that not only product quality but also education for suitable use plays a key role in successful house disinfection. This approach could be an important tool for improving prevention of foodborne infections since fecal coliforms widely predominated in all analyzed samples.

  1. Use of hydrogen peroxide in combination with nisin, sodium lactate and citric acid for reducing transfer of bacterial pathogens from whole melon surfaces to fresh-cut pieces.

    PubMed

    Ukuku, Dike O; Bari, M L; Kawamoto, S; Isshiki, K

    2005-10-15

    Hydrogen peroxide (2.5%) alone or hydrogen peroxide (1%) in combination with nisin (25 microg/ml), sodium lactate (1%), and citric acid (0.5%) (HPLNC) were investigated as potential sanitizers for reducing Escherichia coli O157:H7 or Listeria monocytogenes populations on whole cantaloupe and honeydew melons. Whole cantaloupes inoculated with E. coli O157:H7 and L. monocytogenes at 5.27 and 4.07 log10 CFU/cm2, respectively, and whole honeydew melons inoculated with E. coli O157:H7 and L. monocytogenes at 3.45 and 3.05 log10 CFU/cm2, respectively, were stored at 5 degrees C for 7 days. Antimicrobial washing treatments were applied to inoculated whole melons on days 0 or 7 of storage and surviving bacterial populations and the numbers transferred to fresh-cut pieces were determined. At days 0 and 7 treatment with HPLNC significantly (p<0.05) reduced the numbers of both pathogens, by 3 to 4 log CFU/cm2 on both types of whole melon. Treatment with HPLNC was significantly (p<0.05) more effective than treatment with 2.5% hydrogen peroxide. While fresh-cut pieces prepared from stored whole melons were negative for the pathogens by both direct plating and by enrichment, fresh-cut pieces from cantaloupe melons treated with 2.5% hydrogen peroxide were positive for both pathogens and pieces from honeydew melons were positive for E. coli 0157:H7. The native microflora on fresh-cut melons were also substantially reduced by HPLNC treatment of whole melons. The results suggest that HPLNC could be used to decontaminate whole melon surfaces and so improve the microbial safety and quality of fresh-cut melons.

  2. An engineered micropattern to reduce bacterial colonization, platelet adhesion and fibrin sheath formation for improved biocompatibility of central venous catheters.

    PubMed

    May, Rhea M; Magin, Chelsea M; Mann, Ethan E; Drinker, Michael C; Fraser, John C; Siedlecki, Christopher A; Brennan, Anthony B; Reddy, Shravanthi T

    2015-01-01

    Catheter-related bloodstream infections (CRBSIs) and catheter-related thrombosis (CRT) are common complications of central venous catheters (CVC), which are used to monitor patient health and deliver medications. CVCs are subject to protein adsorption and platelet adhesion as well as colonization by the natural skin flora (i.e. Staphylococcus aureus and Staphylococcus epidermidis). Antimicrobial and antithrombotic drugs can prevent infections and thrombosis-related complications, but have associated resistance and safety risks. Surface topographies have shown promise in limiting platelet and bacterial adhesion, so it was hypothesized that an engineered Sharklet micropattern, inspired by shark-skin, may provide a combined approach as it has wide reaching anti-fouling capabilities. To assess the feasibility for this micropattern to improve CVC-related healthcare outcomes, bacterial colonization and platelet interactions were analyzed in vitro on a material common for vascular access devices. To evaluate bacterial inhibition after simulated vascular exposure, micropatterned thermoplastic polyurethane surfaces were preconditioned with blood proteins in vitro then subjected to a bacterial challenge for 1 and 18 h. Platelet adhesion was assessed with fluorescent microscopy after incubation of the surfaces with platelet-rich plasma (PRP) supplemented with calcium. Platelet activation was further assessed by monitoring fibrin formation with fluorescent microscopy after exposure of the surfaces to platelet-rich plasma (PRP) supplemented with calcium in a flow-cell. Results are reported as percent reductions and significance is based on t-tests and ANOVA models of log reductions. All experiments were replicated at least three times. Blood and serum conditioned micropatterned surfaces reduced 18 h S. aureus and S. epidermidis colonization by 70% (p ≤ 0.05) and 71% (p < 0.01), respectively, when compared to preconditioned unpatterned controls. Additionally

  3. Co-composting of gelatin industry sludge combined with organic fraction of municipal solid waste and poultry waste employing zeolite mixed with enriched nitrifying bacterial consortium.

    PubMed

    Awasthi, Mukesh Kumar; Pandey, Akhilesh Kumar; Bundela, Pushpendra Singh; Wong, Jonathan W C; Li, Ronghua; Zhang, Zengqiang

    2016-08-01

    This work illustrates the co-composting of gelatin industry sludge (GIS) combined with organic fraction of municipal solid waste (OFMSW) and poultry waste (PW) employing 10% zeolite mixed with enriched nitrifying bacteria consortium (ENBC). Five piles of GIS were prepared mixed with OFMSW and PW at 2:1:0.5, 4:1:0.5, 6:1:0.5 and 8:1:0.5 and without GIS 0:1:0.5 (dry weight basis) served as control, while 10% zeolite mixed with ENBC was inoculated in all piles and composted for 42days. The Pile-4 with GIS, OFMSW and PW ratio 6:1:0.5 and 10% zeolite+ENBC were drastically reduced the nitrogen loss and enhance the mineralization rate as compare to other piles. The co-amendment of 6% GIS effectively buffered the pH between ∼7.5 to 8.0 and shortened the compost maturity period, while lower concentration of GIS was comparatively delayed the early decomposition. Therefore, our results suggested that suitability of 10% zeolite+ENBC with initial feedstock ratio 6:1:0.5 as the best formulation for the composting of GIS into value-added stable product.

  4. Intake of butter naturally enriched with cis9,trans11 conjugated linoleic acid reduces systemic inflammatory mediators in healthy young adults.

    PubMed

    Penedo, Letícia A; Nunes, Juliana C; Gama, Marco Antônio S; Leite, Paulo Emilio C; Quirico-Santos, Thereza F; Torres, Alexandre G

    2013-12-01

    A conjugated linoleic acid (CLA) depletion-repletion study was carried out to investigate the effects of dietary c9,t11 CLA on C-reactive protein, transcription factor NFκB, metalloproteinases 2 and 9, inflammatory mediators (adiponectin, TNFα, IL-2, IL-4, IL-8, IL-10), body composition, and erythrocyte membrane composition in healthy normal-weight human adults. CLA depletion was achieved through an 8-week period of restricted dairy fat intake (depletion phase; CLA intake was 5.2±5.8 mg/day), followed by an 8-week period in which individuals consumed 20 g/day of butter naturally enriched with c9,t11 CLA (repletion phase; CLA intake of 1020±167 mg/day). The participants were 29 healthy adult volunteers (19 women and 10 men, aged 22 to 36 years), with body mass index between 18.0 and 29.9 kg m(-2). Blood samples were collected at baseline and at the end of both depletion and repletion phases. The content of CLA in erythrocytes decreased during CLA-depletion and increased during CLA-repletion. Intake of CLA-enriched butter increased the serum levels of anti-inflammatory IL-10 but reduced transcription factor NFκB in blood and serum levels of TNFα, IL-2, IL-8 and inactive metalloproteinase-9. Moreover, reduced activity of metalloproteinases 2 and 9 in serum was observed during the CLA-repletion period. In contrast, intake of CLA-enriched butter had no effects on body composition (DXA analysis) as well as on serum levels of adiponectin, C-reactive protein, and IL-4. Taken together, our results indicate that the intake of a c9,t11 CLA-enriched butter by normal-weight subjects induces beneficial changes in immune modulators associated with sub-clinical inflammation in overweight individuals.

  5. Paediatric Crohn disease patients with stricturing behaviour exhibit ileal granulocyte-macrophage colony-stimulating factor (GM-CSF) autoantibody production and reduced neutrophil bacterial killing and GM-CSF bioactivity.

    PubMed

    Jurickova, I; Collins, M H; Chalk, C; Seese, A; Bezold, R; Lake, K; von Allmen, D; Frischer, J S; Falcone, R A; Trapnell, B C; Denson, L A

    2013-06-01

    Granulocyte-macrophage colony-stimulating factor (GM-CSF) autoantibodies are associated with stricturing behaviour in Crohn disease (CD). We hypothesized that CD ileal lamina propria mononuclear cells (LPMC) would produce GM-CSF autoantibodies and peripheral blood (PB) samples would contain GM-CSF neutralizing capacity (NC). Paediatric CD and control PBMC and ileal biopsies or LPMC were isolated and cultured and GM-CSF, immunoglobulin (Ig)G and GM-CSF autoantibodies production were measured by enzyme-linked immunosorbent assay (ELISA). Basal and GM-CSF-primed neutrophil bacterial killing and signal transducer and activator of transcription 5 (STAT5) tyrosine phosphorylation (pSTAT5) were measured by flow cytometry. GM-CSF autoantibodies were enriched within total IgG for LPMC isolated from CD ileal strictures and proximal margins compared to control ileum. Neutrophil bacterial killing was reduced in CD patients compared to controls. Within CD, neutrophil GM-CSF-dependent STAT5 activation and bacterial killing were reduced as GM-CSF autoantibodies increased. GM-CSF stimulation of pSTAT5 did not vary between controls and CD patients in washed PB granulocytes in which serum was removed. However, GM-CSF stimulation of pSTAT5 was reduced in whole PB samples from CD patients. These data were used to calculate the GM-CSF NC. CD patients with GM-CSF NC greater than 25% exhibited a fourfold higher rate of stricturing behaviour and surgery. The likelihood ratio (95% confidence interval) for stricturing behaviour for patients with elevation in both GM-CSF autoantibodies and GM-CSF NC was equal to 5 (2, 11). GM-CSF autoantibodies are produced by LPMC isolated from CD ileal resection specimens and are associated with reduced neutrophil bacterial killing. CD peripheral blood contains GM-CSF NC, which is associated with increased rates of stricturing behaviour. © 2013 British Society for Immunology.

  6. Paediatric Crohn disease patients with stricturing behaviour exhibit ileal granulocyte–macrophage colony-stimulating factor (GM-CSF) autoantibody production and reduced neutrophil bacterial killing and GM-CSF bioactivity

    PubMed Central

    Jurickova, I; Collins, M H; Chalk, C; Seese, A; Bezold, R; Lake, K; Allmen, D; Frischer, J S; Falcone, R A; Trapnell, B C; Denson, L A

    2013-01-01

    Granulocyte–macrophage colony-stimulating factor (GM-CSF) autoantibodies are associated with stricturing behaviour in Crohn disease (CD). We hypothesized that CD ileal lamina propria mononuclear cells (LPMC) would produce GM-CSF autoantibodies and peripheral blood (PB) samples would contain GM-CSF neutralizing capacity (NC). Paediatric CD and control PBMC and ileal biopsies or LPMC were isolated and cultured and GM-CSF, immunoglobulin (Ig)G and GM-CSF autoantibodies production were measured by enzyme-linked immunosorbent assay (ELISA). Basal and GM-CSF-primed neutrophil bacterial killing and signal transducer and activator of transcription 5 (STAT5) tyrosine phosphorylation (pSTAT5) were measured by flow cytometry. GM-CSF autoantibodies were enriched within total IgG for LPMC isolated from CD ileal strictures and proximal margins compared to control ileum. Neutrophil bacterial killing was reduced in CD patients compared to controls. Within CD, neutrophil GM-CSF-dependent STAT5 activation and bacterial killing were reduced as GM-CSF autoantibodies increased. GM-CSF stimulation of pSTAT5 did not vary between controls and CD patients in washed PB granulocytes in which serum was removed. However, GM-CSF stimulation of pSTAT5 was reduced in whole PB samples from CD patients. These data were used to calculate the GM-CSF NC. CD patients with GM-CSF NC greater than 25% exhibited a fourfold higher rate of stricturing behaviour and surgery. The likelihood ratio (95% confidence interval) for stricturing behaviour for patients with elevation in both GM-CSF autoantibodies and GM-CSF NC was equal to 5 (2, 11). GM-CSF autoantibodies are produced by LPMC isolated from CD ileal resection specimens and are associated with reduced neutrophil bacterial killing. CD peripheral blood contains GM-CSF NC, which is associated with increased rates of stricturing behaviour. PMID:23600834

  7. Magnesium aminoclay enhances lipid production of mixotrophic Chlorella sp. KR-1 while reducing bacterial populations.

    PubMed

    Kim, Bohwa; Praveenkumar, Ramasamy; Lee, Jiye; Nam, Bora; Kim, Dong-Myung; Lee, Kyubock; Lee, Young-Chul; Oh, You-Kwan

    2016-11-01

    Improving lipid productivity and preventing overgrowth of contaminating bacteria are critical issues relevant to the commercialization of the mixotrophic microalgae cultivation process. In this paper, we report the use of magnesium aminoclay (MgAC) nanoparticles for enhanced lipid production from oleaginous Chlorella sp. KR-1 with simultaneous control of KR-1-associated bacterial growth in mixotrophic cultures with glucose as the model substrate. Addition of 0.01-0.1g/L MgAC promoted microalgal biomass production better than the MgAC-less control, via differential biocidal effects on microalgal and bacterial cells (the latter being more sensitive to MgAC's bio-toxicity than the former). The inhibition effect of MgAC on co-existing bacteria was, as based on density-gradient-gel-electrophoresis (DGGE) analysis, largely dosage-dependent and species-specific. MgAC also, by inducing an oxidative stress environment, increased both the cell size and lipid content of KR-1, resulting in a considerable, ∼25% improvement of mixotrophic algal lipid productivity (to ∼410mgFAME/L/d) compared with the untreated control.

  8. Methods to reduce bacterial contamination of recycling cooling systems of a CHPP

    NASA Astrophysics Data System (ADS)

    Chichirova, N. D.; Chichirov, A. A.; Vlasov, S. M.; Vlasova, A. Yu.

    2015-07-01

    Bacterial contamination of circulating and make-up water of the nonconjugated recycling cooling system with evaporative cooling towers of thermal power plants is studied. The nonconjugated recycling cooling system of Naberezhnochelninskaya CHP Plant was selected as the object of study. It was found that circulating water of recycling cooling is highly contaminated with aerobic heterotrophic bacteria. At the same time, make-up water for the cooling system from the Kama River is moderately polluted with anaerobic bacteria. Measurements of biological contamination in different parts of the recycling cooling system showed that populations of colonies of microorganisms abruptly decreases in turbine condensers, which is probably indicative of their death and deposition on the heat transfer surface of the condenser. Calculation using a special program showed that biological contamination of the recycling cooling system poses the greatest risks for clogging of the equipment (seven points on a nine-point scale), its corrosion (two points), and damage to the health of personnel (two points). Rapid development of aerobic bacteria apparently occurs under elevated temperature and intense aeration of water in the cooling tower. It is suggested to periodically monitor the recycling cooling system for biological pollution and to set a timetable for bactericidal treatment of circulating water depending on the level of its bacterial contamination.

  9. Nitrate reducing bacterial activity in concrete cells of nuclear waste disposal

    NASA Astrophysics Data System (ADS)

    Alquier, M.; Kassim, C.; Bertron, A.; Rafrafi, Y.; Sablayrolles, C.; Albrecht, A.; Erable, B.

    2013-07-01

    Leaching experiments of solid matrices (bitumen and cement pastes) have been first implemented to define the physicochemical conditions that microorganisms are likely to meet at the bitumen-concrete interface (see the paper of Bertron et al.). Of course, as might be suspected, the cement matrix imposes highly alkaline pH conditions (10 bacterial strains led us to select Halomonas desiderata as a model bacterium capable of catalyzing the reaction of nitrate reduction in these extreme conditions of pH. The denitrifying activity of Halomonas desiderata was quantified in batch bioreactor in the presence of solid matrices and / or leachate from bitumen and cement matrices. Denitrification was relatively fast in the presence of cement matrix (<100 hours) and 2 to 3 times slower in the presence of bituminous matrix. Overall, the presence of solid cement promoted the kinetics of denitrification. The observation of solid surfaces at the end of the experiment revealed the presence of a biofilm of Halomonas desiderata on the cement paste surface. These attached bacteria showed a denitrifying activity comparable to planktonic bacterial culture. On the other side, no colonization of bitumen could be highlighted as either by SEM or epifluorescence microscopy. Now, we are currently developing a continuous experimental bioreactor which should allow us a more rational understanding of the bitumen-cement-microbe interactions.

  10. Microscale patterned surfaces reduce bacterial fouling-microscopic and theoretical analysis.

    PubMed

    Vasudevan, Ravikumar; Kennedy, Alan J; Merritt, Megan; Crocker, Fiona H; Baney, Ronald H

    2014-05-01

    Microscale patterned surfaces have been shown to control the arrangement of bacteria attached to surfaces. This study was conducted to examine the effect of patterned topographies on bacterial fouling using Enterobacter cloacae as the test model. E. cloacae is an opportunistic pathogen involved frequently in nosocomial infections. It is an important model organism to be studied in the context of healthcare associated infections (HAI) and polydimethylsiloxane (PDMS) based urinary catheter fouling. Patterned surfaces, such as Sharklet™, have shown the promise of being a benign surface treatment for prevention of catheter associated urinary tract infections (CAUTI). To the best of our knowledge, inhibition of fouling by E. cloacae has not been demonstrated on microscale patterned PDMS surfaces. In this study, the Sharklet™ and smooth PDMS surfaces were used as controls. All pattern surfaces had statistically significantly lower percentage area coverage compared to the smooth PDMS control. A cross type feature (C-1-PDMS), demonstrated the most significant reduction in percent area coverage, 89% (p<0.01, α=0.05), compared to the smooth PDMS control and all other patterned test surfaces. Additionally, theoretical calculations show that C-1-PDMS is the only surface predicted to hold the thermodynamically stable Cassie state, which occurs due to trapping air pockets at the liquid-solid interface. Combined the results provide new insights for designing environmentally benign, novel, microscale patterned surfaces for restricting bacterial fouling. Copyright © 2014 Elsevier B.V. All rights reserved.

  11. Improved production of reducing sugars from rice husk and rice straw using bacterial cellulase and xylanase activated with hydroxyapatite nanoparticles.

    PubMed

    Dutta, Nalok; Mukhopadhyay, Arka; Dasgupta, Anjan Kr; Chakrabarti, Krishanu

    2014-02-01

    Purified bacterial cellulase and xylanase were activated in the presence of calcium hydroxyapatite nanoparticles (NP) with concomitant increase in thermostability about 35% increment in production of d-xylose and reducing sugars from rice husk and rice straw was obtained at 80°C by the sequential treatment of xylanase and cellulase enzymes in the presence of NP compared to the untreated enzyme sets. Our findings suggested that if the rice husk and the rice straw samples were pre-treated with xylanase prior to treatment with cellulase, the percentage increase of reducing sugar per 100g of substrate (starting material) was enhanced by about 29% and 41%, respectively. These findings can be utilized for the extraction of reducing sugars from cellulose and xylan containing waste material. The purely enzymatic extraction procedure can be substituted for the harsh and bio-adverse chemical methods.

  12. Addition of Selenium Nanoparticles to Electrospun Silk Scaffold Improves the Mammalian Cell Activity While Reducing Bacterial Growth

    PubMed Central

    Chung, Stanley; Ercan, Batur; Roy, Amit K.; Webster, Thomas J.

    2016-01-01

    Silk possesses many beneficial wound healing properties, and electrospun scaffolds are especially applicable for skin applications, due to their smaller interstices and higher surface areas. However, purified silk promotes microbial growth. Selenium nanoparticles have shown excellent antibacterial properties and are a novel antimicrobial chemistry. Here, electrospun silk scaffolds were doped with selenium nanoparticles to impart antibacterial properties to the silk scaffolds. Results showed significantly improved bacterial inhibition and mild improvement in human dermal fibroblast metabolic activity. These results suggest that the addition of selenium nanoparticles to electrospun silk is a promising approach to improve wound healing with reduced infection, without relying on antibiotics. PMID:27471473

  13. High-oleic canola oil consumption enriches LDL particle cholesteryl oleate content and reduces LDL proteoglycan binding in humans

    PubMed Central

    Jones, Peter J. H.; MacKay, Dylan. S.; Senanayake, Vijitha K.; Pu, Shuaihua; Jenkins, David J. A.; Connelly, Philip W.; Lamarche, Benoît; Couture, Patrick; Kris-Etherton, Penny M.; West, Sheila G.; Liu, Xiaoran; Fleming, Jennifer A.; Hantgan, Roy R.; Rudel, Lawrence L.

    2015-01-01

    Oleic acid consumption is considered cardio-protective according to studies conducted examining effects of the Mediterranean diet. However, animal models have shown that oleic acid consumption increases LDL particle cholesteryl oleate content which is associated with increased LDL-proteoglycan binding and atherosclerosis. The objective was to examine effects of varying oleic, linoleic and docosahexaenoic acid consumption on human LDL-proteoglycan binding in a non-random subset of the Canola Oil Multi-center Intervention Trial (COMIT) participants. COMIT employed a randomized, double-blind, five-period, cross-over trial design. Three of the treatment oil diets; 1) a blend of corn/safflower oil (25:75); 2) high oleic canola oil; and 3) DHA-enriched high oleic canola oil were selected for analysis of LDL-proteoglycan binding in 50 participants exhibiting good compliance. LDL particles were isolated from frozen plasma by gel filtration chromatography and LDL cholesteryl esters quantified by mass-spectrometry. LDL-proteoglycan binding was assessed using surface plasmon resonance. LDL particle cholesterol ester fatty acid composition was sensitive to the treatment fatty acid compositions, with the main fatty acids in the treatments increasing in the LDL cholesterol esters. The corn/safflower oil and high-oleic canola oil diets lowered LDL-proteoglycan binding relative to their baseline values (p=0.0005 and p=0.0012, respectively). At endpoint, high-oleic canola oil feeding resulted in lower LDL-proteoglycan binding than corn/safflower oil (p=0.0243) and DHA-enriched high oleic canola oil (p=0.0249), although high-oleic canola oil had the lowest binding at baseline (p=0.0344). Our findings suggest that high-oleic canola oil consumption in humans increases cholesteryl oleate percentage in LDL, but in a manner not associated with a rise in LDL-proteoglycan binding. PMID:25528432

  14. High-oleic canola oil consumption enriches LDL particle cholesteryl oleate content and reduces LDL proteoglycan binding in humans.

    PubMed

    Jones, Peter J H; MacKay, Dylan S; Senanayake, Vijitha K; Pu, Shuaihua; Jenkins, David J A; Connelly, Philip W; Lamarche, Benoît; Couture, Patrick; Kris-Etherton, Penny M; West, Sheila G; Liu, Xiaoran; Fleming, Jennifer A; Hantgan, Roy R; Rudel, Lawrence L

    2015-02-01

    Oleic acid consumption is considered cardio-protective according to studies conducted examining effects of the Mediterranean diet. However, animal models have shown that oleic acid consumption increases LDL particle cholesteryl oleate content which is associated with increased LDL-proteoglycan binding and atherosclerosis. The objective was to examine effects of varying oleic, linoleic and docosahexaenoic acid consumption on human LDL-proteoglycan binding in a non-random subset of the Canola Oil Multi-center Intervention Trial (COMIT) participants. COMIT employed a randomized, double-blind, five-period, cross-over trial design. Three of the treatment oil diets: 1) a blend of corn/safflower oil (25:75); 2) high oleic canola oil; and 3) DHA-enriched high oleic canola oil were selected for analysis of LDL-proteoglycan binding in 50 participants exhibiting good compliance. LDL particles were isolated from frozen plasma by gel filtration chromatography and LDL cholesteryl esters quantified by mass-spectrometry. LDL-proteoglycan binding was assessed using surface plasmon resonance. LDL particle cholesterol ester fatty acid composition was sensitive to the treatment fatty acid compositions, with the main fatty acids in the treatments increasing in the LDL cholesterol esters. The corn/safflower oil and high-oleic canola oil diets lowered LDL-proteoglycan binding relative to their baseline values (p = 0.0005 and p = 0.0012, respectively). At endpoint, high-oleic canola oil feeding resulted in lower LDL-proteoglycan binding than corn/safflower oil (p = 0.0243) and DHA-enriched high oleic canola oil (p = 0.0249), although high-oleic canola oil had the lowest binding at baseline (p = 0.0344). Our findings suggest that high-oleic canola oil consumption in humans increases cholesteryl oleate percentage in LDL, but in a manner not associated with a rise in LDL-proteoglycan binding.

  15. Orally Administered P22 Phage Tailspike Protein Reduces Salmonella Colonization in Chickens: Prospects of a Novel Therapy against Bacterial Infections

    PubMed Central

    Waseh, Shakeeba; Hanifi-Moghaddam, Pejman; Coleman, Russell; Masotti, Michael; Ryan, Shannon; Foss, Mary; MacKenzie, Roger; Henry, Matthew; Szymanski, Christine M.; Tanha, Jamshid

    2010-01-01

    One of the major causes of morbidity and mortality in man and economically important animals is bacterial infections of the gastrointestinal (GI) tract. The emergence of difficult-to-treat infections, primarily caused by antibiotic resistant bacteria, demands for alternatives to antibiotic therapy. Currently, one of the emerging therapeutic alternatives is the use of lytic bacteriophages. In an effort to exploit the target specificity and therapeutic potential of bacteriophages, we examined the utility of bacteriophage tailspike proteins (Tsps). Among the best-characterized Tsps is that from the Podoviridae P22 bacteriophage, which recognizes the lipopolysaccharides of Salmonella enterica serovar Typhimurium. In this study, we utilized a truncated, functionally equivalent version of the P22 tailspike protein, P22sTsp, as a prototype to demonstrate the therapeutic potential of Tsps in the GI tract of chickens. Bacterial agglutination assays showed that P22sTsp was capable of agglutinating S. Typhimurium at levels similar to antibodies and incubating the Tsp with chicken GI fluids showed no proteolytic activity against the Tsp. Testing P22sTsp against the three major GI proteases showed that P22sTsp was resistant to trypsin and partially to chymotrypsin, but sensitive to pepsin. However, in formulated form for oral administration, P22sTsp was resistant to all three proteases. When administered orally to chickens, P22sTsp significantly reduced Salmonella colonization in the gut and its further penetration into internal organs. In in vitro assays, P22sTsp effectively retarded Salmonella motility, a factor implicated in bacterial colonization and invasion, suggesting that the in vivo decolonization ability of P22sTsp may, at least in part, be due to its ability to interfere with motility… Our findings show promise in terms of opening novel Tsp-based oral therapeutic approaches against bacterial infections in production animals and potentially in humans. PMID:21124920

  16. Wastewater Treatment Effluent Reduces the Abundance and Diversity of Benthic Bacterial Communities in Urban and Suburban Rivers

    PubMed Central

    Drury, Bradley; Rosi-Marshall, Emma

    2013-01-01

    In highly urbanized areas, wastewater treatment plant (WWTP) effluent can represent a significant component of freshwater ecosystems. As it is impossible for the composition of WWTP effluent to match the composition of the receiving system, the potential exists for effluent to significantly impact the chemical and biological characteristics of the receiving ecosystem. We assessed the impacts of WWTP effluent on the size, activity, and composition of benthic microbial communities by comparing two distinct field sites in the Chicago metropolitan region: a highly urbanized river receiving effluent from a large WWTP and a suburban river receiving effluent from a much smaller WWTP. At sites upstream of effluent input, the urban and suburban rivers differed significantly in chemical characteristics and in the composition of their sediment bacterial communities. Although effluent resulted in significant increases in inorganic nutrients in both rivers, surprisingly, it also resulted in significant decreases in the population size and diversity of sediment bacterial communities. Tag pyrosequencing of bacterial 16S rRNA genes revealed significant effects of effluent on sediment bacterial community composition in both rivers, including decreases in abundances of Deltaproteobacteria, Desulfococcus, Dechloromonas, and Chloroflexi sequences and increases in abundances of Nitrospirae and Sphingobacteriales sequences. The overall effect of the WWTP inputs was that the two rivers, which were distinct in chemical and biological properties upstream of the WWTPs, were almost indistinguishable downstream. These results suggest that WWTP effluent has the potential to reduce the natural variability that exists among river ecosystems and indicate that WWTP effluent may contribute to biotic homogenization. PMID:23315724

  17. Seagrass ecosystems reduce exposure to bacterial pathogens of humans, fishes, and invertebrates.

    PubMed

    Lamb, Joleah B; van de Water, Jeroen A J M; Bourne, David G; Altier, Craig; Hein, Margaux Y; Fiorenza, Evan A; Abu, Nur; Jompa, Jamaluddin; Harvell, C Drew

    2017-02-17

    Plants are important in urban environments for removing pathogens and improving water quality. Seagrass meadows are the most widespread coastal ecosystem on the planet. Although these plants are known to be associated with natural biocide production, they have not been evaluated for their ability to remove microbiological contamination. Using amplicon sequencing of the 16S ribosomal RNA gene, we found that when seagrass meadows are present, there was a 50% reduction in the relative abundance of potential bacterial pathogens capable of causing disease in humans and marine organisms. Moreover, field surveys of more than 8000 reef-building corals located adjacent to seagrass meadows showed twofold reductions in disease levels compared to corals at paired sites without adjacent seagrass meadows. These results highlight the importance of seagrass ecosystems to the health of humans and other organisms.

  18. Hydrogels with Modulated Ionic Load for Mammalian Cell Harvesting with Reduced Bacterial Adhesion.

    PubMed

    Gallardo, Alberto; Martínez-Campos, Enrique; García, Carolina; Cortajarena, Aitziber L; Rodríguez-Hernández, Juan

    2017-05-08

    In this manuscript, we describe the fabrication of hydrogel supports for mammalian cell handling that can simultaneously prevent materials from microbial contamination and therefore allow storage in aqueous media. For that purpose, hydrogels based on the antifouling polymer polyvinylpyrrolidone (PVP) were functionalized with different ionic groups (anionic, cationic, or two types of zwitterions). In order to prevent bacterial adhesion in the long-term, we took advantage of the synergistic effect of inherently antifouling PVP and additional antifouling moieties incorporated within the hydrogel structure. We evaluated, in a separated series of experiments, both the capability of the materials to act as supports for the growth of mammalian cell monolayers for transplantation (using C-166-GFP endothelial cell line), as well their antifouling properties against Staphylococcus aureus, were studied. All of the hydrogels are structurally pseudodouble networks with high swelling (around 90%) and similar mechanical properties (in the low range for hydrogel materials with Young modulus below 1250 kPa). With some differences, all the charged hydrogels were capable of hosting mouse endothelial cell line C166-GFP to confluence, as well as a monolayer detachment and transplantation through simple mechanical agitation. On the contrary, the uncharged hydrogel was not capable to detach a full monolayer for transplantation. Bacterial adhesion and proliferation was highly sensitive to the functionality (type of charge and density). In particular, we evidenced that monomers bearing zwitterionic sulfobetaine groups, those negatively charged as well as "electro neutral" hydrogels fabricated from stoichiometric amounts of positive and negative units, exhibit excellent antifouling properties both at initial adhesion times and during longer periods up to 72 h.

  19. Degradative capacities and 16S rRNA-targeted whole-cell hybridization of sulfate-reducing bacteria in an anaerobic enrichment culture utilizing alkylbenzenes from crude oil.

    PubMed Central

    Rabus, R; Fukui, M; Wilkes, H; Widdle, F

    1996-01-01

    A mesophilic sulfate-reducing enrichment culture growing anaerobically on crude oil was used as a model system to study which nutritional types of sulfate-reducing bacteria may develop on original petroleum constituents in oil wells, tanks, and pipelines. Chemical analysis of oil hydrocarbons during growth revealed depletion of toluene and o-xylene within 1 month and of m-xylene, o-ethyltoluene, m-ethyltoluene, m-propyltoluene, and m-isopropyltoluene within approximately 2 months. In anaerobic counting series, the highest numbers of CFU (6 x 10(6) to 8 x 10(6) CFU ml-1) were obtained with toluene and benzoate. Almost the same numbers were obtained with lactate, a substrate often used for detection of the vibrio-shaped, incompletely oxidizing Desulfovibrio sp. In the present study, however, lactate yielded mostly colonies of oval to rod-shaped, completely oxidizing, sulfate-reducing bacteria which were able to grow slowly on toluene or crude oil. Desulfovibrio species were detected only at low numbers (3 x 10(5) CFU ml-1). In agreement with this finding, a fluorescently labeled, 16S rRNA-targeted oligonucleotide probe described in the literature as specific for members of the Desulfovibrionaceae (suggested family) hybridized only with a small portion (< 5%) of the cells in the enrichment culture. These results are consistent with the observation that known Desulfovibrio species do not utilize aromatic hydrocarbons, the predominant substrates in the enrichment culture. All known sulfate-reducing bacteria which utilize aromatic compounds belong to a separate branch, the Desulfobacteriaceae (suggested family). Most members of this family are complete oxidizers. For specific hybridization with members of this branch, the probe had to be modified by a nucleotide exchange. Indeed, this modified probe hybridized with more than 95% of the cells in the enrichment culture. The results show that completely oxidizing, alkylbenzene-utilizing sulfate-reducing bacteria rather than

  20. Altering Transplantation Time to Avoid Periods of High Temperature Can Efficiently Reduce Bacterial Wilt Disease Incidence with Tomato

    PubMed Central

    Wei, Zhong; Huang, Jian-Feng; Hu, Jie; Gu, Yi-An; Yang, Chun-Lan; Mei, Xin-Lan; Shen, Qi-Rong; Xu, Yang-Chun; Friman, Ville-Petri

    2015-01-01

    Tomato bacterial wilt caused by Ralstonia solanacearum bacterium is a severe problem in Southern China, where relatively high environmental temperatures commonly prevails during the crop seasons. Previous research has indicated that bacterial wilt disease incidence generally increases during the warm months of summer leading to reduced tomato yield. Moreover, the efficacy of bio-organic fertilizers (BOFs)–organic compost fortified with pathogen-suppressive bacteria—is often lost during the periods of high environmental temperatures. Here we studied if the disease incidence could be reduced and the BOF performance enhanced by simply preponing and postponing the traditional seedling transplantation times to avoid tomato plant development during periods of high environmental temperature. To this end, a continuous, two-year field experiment was conducted to evaluate the performance of BOF in two traditional (late-spring [LS] and early-autumn [EA]) and two alternative (early-spring [ES] and late-autumn [LA]) crop seasons. We found that changing the transplantation times reduced the mean disease incidence from 33.9% (LS) and 54.7% (EA) to 11.1% (ES) and 7.1% (LA), respectively. Reduction in disease incidence correlated with the reduction in R. Solanacearum pathogen density in the tomato plant rhizosphere and stem base. Applying BOF during alternative transplantation treatments improved biocontrol efficiency from 43.4% (LS) and 3.1% (EA) to 67.4% (ES) and 64.8% (LA). On average, the mean maximum air temperatures were positively correlated with the disease incidence, and negatively correlated with the BOF biocontrol efficacy over the crop seasons. Crucially, even though preponing the transplantation time reduced the tomato yield in general, it was still economically more profitable compared to LS season due to reduced crop losses and relatively higher market prices. Preponing and postponing traditional tomato transplantation times to cooler periods could thus offer

  1. Altering Transplantation Time to Avoid Periods of High Temperature Can Efficiently Reduce Bacterial Wilt Disease Incidence with Tomato.

    PubMed

    Wei, Zhong; Huang, Jian-Feng; Hu, Jie; Gu, Yi-An; Yang, Chun-Lan; Mei, Xin-Lan; Shen, Qi-Rong; Xu, Yang-Chun; Friman, Ville-Petri

    2015-01-01

    Tomato bacterial wilt caused by Ralstonia solanacearum bacterium is a severe problem in Southern China, where relatively high environmental temperatures commonly prevails during the crop seasons. Previous research has indicated that bacterial wilt disease incidence generally increases during the warm months of summer leading to reduced tomato yield. Moreover, the efficacy of bio-organic fertilizers (BOFs)-organic compost fortified with pathogen-suppressive bacteria-is often lost during the periods of high environmental temperatures. Here we studied if the disease incidence could be reduced and the BOF performance enhanced by simply preponing and postponing the traditional seedling transplantation times to avoid tomato plant development during periods of high environmental temperature. To this end, a continuous, two-year field experiment was conducted to evaluate the performance of BOF in two traditional (late-spring [LS] and early-autumn [EA]) and two alternative (early-spring [ES] and late-autumn [LA]) crop seasons. We found that changing the transplantation times reduced the mean disease incidence from 33.9% (LS) and 54.7% (EA) to 11.1% (ES) and 7.1% (LA), respectively. Reduction in disease incidence correlated with the reduction in R. Solanacearum pathogen density in the tomato plant rhizosphere and stem base. Applying BOF during alternative transplantation treatments improved biocontrol efficiency from 43.4% (LS) and 3.1% (EA) to 67.4% (ES) and 64.8% (LA). On average, the mean maximum air temperatures were positively correlated with the disease incidence, and negatively correlated with the BOF biocontrol efficacy over the crop seasons. Crucially, even though preponing the transplantation time reduced the tomato yield in general, it was still economically more profitable compared to LS season due to reduced crop losses and relatively higher market prices. Preponing and postponing traditional tomato transplantation times to cooler periods could thus offer simple

  2. Enriched housing enhances recovery of limb placement ability and reduces aggrecan-containing perineuronal nets in the rat somatosensory cortex after experimental stroke.

    PubMed

    Madinier, Alexandre; Quattromani, Miriana Jlenia; Sjölund, Carin; Ruscher, Karsten; Wieloch, Tadeusz

    2014-01-01

    Stroke causes life long disabilities where few therapeutic options are available. Using electrical and magnetic stimulation of the brain and physical rehabilitation, recovery of brain function can be enhanced even late after stroke. Animal models support this notion, and housing rodents in an enriched environment (EE) several days after experimental stroke stimulates lost brain function by multisensory mechanisms. We studied the dynamics of functional recovery of rats with a lesion to the fore and hind limb motor areas induced by photothrombosis (PT), and with subsequent housing in either standard (STD) or EE. In this model, skilled motor function is not significantly enhanced by enriched housing, while the speed of recovery of sensori-motor function substantially improves over the 9-week study period. In particular, this stroke lesion completely obliterates the fore and hind limb placing ability when visual and whisker guidance is prevented, a deficit that persists for up to 9 weeks of recovery, but that is markedly restored within 2 weeks by enriched housing. Enriched housing after stroke also leads to a significant loss of perineuronal net (PNN) immunoreactivity; detection of aggrecan protein backbone with AB1031 antibody was decreased by 13-22%, and labelling of a glycan moiety of aggrecan with Cat-315 antibody was reduced by 25-30% in the peri-infarct area and in the somatosensory cortex, respectively. The majority of these cells are parvalbumin/GABA inhibitory interneurons that are important in sensori-information processing. We conclude that damage to the fore and hind limb motor areas provides a model of loss of limb placing response without visual guidance, a deficit also seen in more than 50% of stroke patients. This loss is amenable to recovery induced by multiple sensory stimulation and correlates with a decrease in aggrecan-containing PNNs around inhibitory interneurons. Modulating the PNN structure after ischemic damage may provide new therapies

  3. Selenium nanoparticle-enriched Lactobacillus brevis causes more efficient immune responses in vivo and reduces the liver metastasis in metastatic form of mouse breast cancer

    PubMed Central

    2013-01-01

    Background and the purpose of the study Selenium enriched Lactobacillus has been reported as an immunostimulatory agent which can be used to increase the life span of cancer bearing animals. Lactic acid bacteria can reduce selenium ions to elemental selenium nanoparticles (SeNPs) and deposit them in intracellular spaces. In this strategy two known immunostimulators, lactic acid bacteria (LAB) and SeNPs, are concomitantly administered for enhancing of immune responses in cancer bearing mice. Methods Forty five female inbred BALB/c mice were divided into three groups of tests and control, each containing 15 mice. Test mice were orally administered with SeNP-enriched Lactobacillus brevis or Lactobacillus brevis alone for 3 weeks before tumor induction. After that the administration was followed in three cycles of seven days on/three days off. Control group received phosphate buffer saline (PBS) at same condition. During the study the tumor growth was monitored using caliper method. At the end of study the spleen cell culture was carried out for both NK cytotoxicity assay and cytokines measurement. Delayed type hypersensitivity (DTH) responses were also assayed after 72h of tumor antigen recall. Serum lactate dehydrogenase (LDH) and alkaline phosphatase (ALP) levels were measured, the livers of mice were removed and prepared for histopathological analysis. Results High level of IFN-γ and IL-17 besides the significant raised in NK cytotoxicity and DTH responses were observed in SeNP-enriched L. brevis administered mice and the extended life span and decrease in the tumor metastasis to liver were also recorded in this group compared to the control mice or L.brevis alone administered mice. Conclusion Our results suggested that the better prognosis could be achieved by oral administration of SeNP-enriched L. brevis in highly metastatic breast cancer mice model. PMID:23631392

  4. Reduced-fat Gouda-type cheese enriched with vitamin D3 effectively prevents vitamin D deficiency during winter months in postmenopausal women in Greece.

    PubMed

    Manios, Yannis; Moschonis, George; Mavrogianni, Christina; van den Heuvel, Eghm; Singh-Povel, Cécile M; Kiely, Mairead; Cashman, Kevin D

    2016-07-22

    The primary aim of the present study was to examine the effectiveness of daily consumption of vitamin D3-enriched, reduced-fat Gouda-type cheese on 25-hydroxyvitamin D (25(OH)D) concentration in postmenopausal women. Health-related quality of life (HRQL) indices were examined as secondary outcomes. This is a single-blinded (i.e., to study participants), randomized, controlled food-based dietary intervention study. A sample of 79 postmenopausal women (55-75 years old) was randomized either to a control group (CG: n = 39) or an intervention group (IG: n = 40) that consumed, as part of their usual diet, 60 g of either non-enriched or vitamin D3 enriched Gouda-type cheese, respectively, for eight consecutive weeks (i.e., from January to March 2015). Sixty grams of enriched cheese provided a daily dose of 5.7 μg of vitamin D3. There was a differential response of mean (95 % CI) serum 25(OH)D levels in the IG and CG, with the former increasing and the latter decreasing significantly over the eight weeks of the trial [i.e., by 5.1 (3.4, 6.9) nmol/L vs. -4.6 (-6.4, -2.8) nmol/L, P < 0.001, respectively]. The percentages of study participants with 25(OH)D levels <30 (deficiency) and <50 nmol/L (insufficiency) were significantly higher at follow-up in the CG compared to the IG (41.0 vs. 0 %, P < 0.001 and 74.4 vs. 47.5 %, P < 0.001, respectively). The emotional well-being scale of the HRQL score increased in the IG compared to a decrease in the CG (3.2 vs. -3.8, P = 0.028). However, none of the other seven scales of the HRQL score significantly differentiated between study groups (P > 0.1). Consumption of 60 g of vitamin D3-enriched, reduced-fat Gouda-type cheese provided a daily dose of 5.7 μg of additional vitamin D3 and was effective in increasing mean serum 25(OH)D concentration and in counteracting vitamin D deficiency during winter months in postmenopausal women in Greece.

  5. Bacterial ethane formation from reduced, ethylated sulfur compounds in anoxic sediments

    USGS Publications Warehouse

    Oremland, R.S.; Whiticar, Michael J.; Strohmaier, F.E.; Kiene, R.P.

    1988-01-01

    Trace levels of ethane were produced biologically in anoxic sediment slurries from five chemically different aquatic environments. Gases from these locations displayed biogenic characteristics, having 12C-enriched values of ??13CH4 (-62 to -86%.), ??13C2H6 (-35 to -55%.) and high ratios (720 to 140,000) of CH4 [C2H6 + C3H8]. Endogenous production of ethane by slurries was inhibited by autoclaving or by addition of the inhibitor of methanogenic bacteria, 2-bromoethanesulfonic acid (BES). Ethane formation was stimulated markedly by ethanethiol (ESH), and, to a lesser extent, by diethylsulfide (DES). Formation of methane and ethane in ESH- or DES-amended slurries was blocked by BES. Experiments showed that ethionine (or an analogous compound) could be a precursor of ESH. Ethylamine or ethanol additions to slurries caused only a minor stimulation of ethane formation. Similarly, propanethiol additions resulted in only a minor enhancement of propane formation. Cell suspensions of a methyltrophic methanogen produced traces of ethane when incubated in the presence of DES, although the organism did not grow on this compound. These results indicate that methanogenic bacteria produce ethane from the traces of ethylated sulfur compounds present in recent sediments. Preliminary estimates of stable carbon isotope fractionation associated with sediment methane formation from dimethylsulfide was about 40%., while ethane formation from DES and ESH was only 4. 6 and 6.5%., respectively. ?? 1988.

  6. Reduced bacterial growth and increased osteoblast proliferation on titanium with a nanophase TiO2 surface treatment

    PubMed Central

    Bhardwaj, Garima; Webster, Thomas J

    2017-01-01

    Background The attachment and initial growth of bacteria on an implant surface dictates the progression of infection. Treatment often requires aggressive antibiotic use, which does not always work. To overcome the difficulties faced in systemic and local antibiotic delivery, scientists have forayed into using alternative techniques, which includes implant surface modifications that prevent initial bacterial adhesion, foreign body formation, and may offer a controlled inflammatory response. Objective The current study focused on using electrophoretic deposition to treat titanium with a nanophase titanium dioxide surface texture to reduce bacterial adhesion and growth. Two distinct nanotopographies were analyzed, Ti-160, an antimicrobial surface designed to greatly reduce bacterial colonization, and Ti-120, an antimicrobial surface with a topography that upregulates osteoblast activity while reducing bacterial colonization; the number following Ti in the nomenclature represents the atomic force microscopy root-mean-square roughness value in nanometers. Results There was a 95.6% reduction in Staphylococcus aureus (gram-positive bacteria) for the Ti-160-treated surfaces compared to the untreated titanium alloy controls. There was a 90.2% reduction in Pseudomonas aeruginosa (gram-negative bacteria) on Ti-160-treated surfaces compared to controls. For ampicillin-resistant Escherichia coli, there was an 81.1% reduction on the Ti-160-treated surfaces compared to controls. Similarly for surfaces treated with Ti-120, there was an 86.8% reduction in S. aureus, an 82.1% reduction in P. aeruginosa, and a 48.6% reduction in ampicillin-resistant E. coli. The Ti-120 also displayed a 120.7% increase at day 3 and a 168.7% increase at day 5 of osteoblast proliferation over standard titanium alloy control surfaces. Conclusion Compared to untreated surfaces, Ti-160-treated titanium surfaces demonstrated a statistically significant 1 log reduction in S. aureus and P. aeruginosa, whereas

  7. Characterization of bromate-reducing bacterial isolates and their potential for drinking water treatment.

    PubMed

    Davidson, Andrew N; Chee-Sanford, Joanne; Lai, Hoi Yi Mandy; Ho, Chi-hua; Klenzendorf, J Brandon; Kirisits, Mary Jo

    2011-11-15

    The objective of the current study was to isolate and characterize several bromate-reducing bacteria and to examine their potential for bioaugmentation to a drinking water treatment process. Fifteen bromate-reducing bacteria were isolated from three sources. According to 16S rRNA gene sequencing, the bromate-reducing bacteria are phylogenetically diverse, representing the Actinobacteria, Bacteroidetes, Firmicutes, and α-, β-, and γ-Proteobacteria. The broad diversity of bromate-reducing bacteria suggests the widespread capability for microbial bromate reduction. While the cometabolism of bromate via nitrate reductase and (per)chlorate reductase has been postulated, five of our bromate-reducing isolates were unable to reduce nitrate or perchlorate. This suggests that a bromate-specific reduction pathway might exist in some microorganisms. Bioaugmentation of activated carbon filters with eight of the bromate-reducing isolates did not significantly decrease start-up time or increase bromate removal as compared to control filters. To optimize bromate reduction in a biological drinking water treatment process, the predominant mechanism of bromate reduction (i.e., cometabolic or respiratory) needs to be assessed so that appropriate measures can be taken to improve bromate removal.

  8. No evidence that medicinal honey reduces bacterial skin colonisation at a peripheral catheter insertion site in dogs.

    PubMed

    Royaux, E; Polis, I; Boyen, F; Van Ham, L; de Rooster, H

    2016-07-01

    To determine whether topical exit-site application of medicinal honey at the catheter insertion place reduces bacterial skin colonisation. Dogs were selected at random and divided into the honey or the control group. When the catheter was removed, an area of approximately 3×3 cm of the skin at the insertion site was sampled with a sterile cotton swab. The catheter stayed in place for a median of 84 hours. Out of 46 patients, 6 patients in the honey group and 5 out of 54 patients in the control group had a positive skin culture at the time of catheter removal (P=0·547). Infection was clinically suspected in 1 of those 11 dogs; catheter-associated complications were observed in 8 additional dogs that did not have a positive skin culture. Few catheter-associated complications were observed. Extra attention to hygiene by working with a standardised catheter placement and handling protocol might have resulted in this low incidence. In this study topical application of a medicinal honey did not reduce bacterial skin colonisation at the insertion site of peripheral catheters in dogs. © 2016 British Small Animal Veterinary Association.

  9. trans-trans Conjugated linoleic acid enriched soybean oil reduces fatty liver and lowers serum cholesterol in obese zucker rats.

    PubMed

    Gilbert, William; Gadang, Vidya; Proctor, Andrew; Jain, Vishal; Devareddy, Latha

    2011-10-01

    Conjugated linoleic acid (CLA) is a collection of octadecadienoic fatty acids that have been shown to possess numerous health benefits. The CLA used in our study was produced by the photoisomerization of soybean oil and consists of about 20% CLA; this CLA consists of 75% trans-trans (a mixture of t8,t10; t9,t11; t10,t12) isomers. This method could be readily used to increase the CLA content of all soybean oil used as a food ingredient. The objective of this study was to determine the effects of trans-trans CLA-rich soy oil, fed as a dietary supplement, on body composition, dyslipidemia, hepatic steatosis, and markers of glucose control and liver function of obese fa/fa Zucker rats. The trans-trans CLA-rich soy oil lowered the serum cholesterol and low density lipoprotein-cholesterol levels by 41 and 50%, respectively, when compared to obese controls. Trans-trans CLA-rich soy oil supplementation also lowered the liver lipid content significantly (P < 0.05) with a concomitant decrease in the liver weight in the obese rats. In addition, glycated hemoglobin values were improved in the group receiving CLA-enriched soybean oil in comparison to the obese control. PPAR-γ expression in white adipose tissue was unchanged. In conclusion, trans-trans CLA-rich soy oil was effective in lowering total liver lipids and serum cholesterol.

  10. The effect of intraoral suction on oxygen-enriched surgical environments: a mechanism for reducing the risk of surgical fires.

    PubMed

    VanCleave, Andrea M; Jones, James E; McGlothlin, James D; Saxen, Mark A; Sanders, Brian J; Vinson, LaQuia A

    2014-01-01

    In this study, a mechanical model was applied in order to replicate potential surgical fire conditions in an oxygen-enriched environment with and without high-volume suction typical for dental surgical applications. During 41 trials, 3 combustion events were measured: an audible pop, a visible flash of light, and full ignition. In at least 11 of 21 trials without suction, all 3 conditions were observed, sometimes with an extent of fire that required early termination of the experimental trial. By contrast, in 18 of 20 with-suction trials, ignition did not occur at all, and in the 2 cases where ignition did occur, the fire was qualitatively a much smaller, candle-like flame. Statistically comparing these 3 combustion events in the no-suction versus with-suction trials, ignition (P = .0005), audible pop (P = .0211), and flash (P = .0092) were all significantly more likely in the no-suction condition. These results suggest a possible significant and new element to be added to existing surgical fire safety protocols toward making surgical fires the "never-events" they should be.

  11. The Effect of Intraoral Suction on Oxygen-Enriched Surgical Environments: A Mechanism for Reducing the Risk of Surgical Fires

    PubMed Central

    VanCleave, Andrea M.; Jones, James E.; McGlothlin, James D.; Saxen, Mark A.; Sanders, Brian J.; Vinson, LaQuia A.

    2014-01-01

    In this study, a mechanical model was applied in order to replicate potential surgical fire conditions in an oxygen-enriched environment with and without high-volume suction typical for dental surgical applications. During 41 trials, 3 combustion events were measured: an audible pop, a visible flash of light, and full ignition. In at least 11 of 21 trials without suction, all 3 conditions were observed, sometimes with an extent of fire that required early termination of the experimental trial. By contrast, in 18 of 20 with-suction trials, ignition did not occur at all, and in the 2 cases where ignition did occur, the fire was qualitatively a much smaller, candle-like flame. Statistically comparing these 3 combustion events in the no-suction versus with-suction trials, ignition (P = .0005), audible pop (P = .0211), and flash (P = .0092) were all significantly more likely in the no-suction condition. These results suggest a possible significant and new element to be added to existing surgical fire safety protocols toward making surgical fires the “never-events” they should be. PMID:25517551

  12. COX-2 Inhibition Reduces Brucella Bacterial Burden in Draining Lymph Nodes

    PubMed Central

    Gagnaire, Aurélie; Gorvel, Laurent; Papadopoulos, Alexia; Von Bargen, Kristine; Mège, Jean-Louis; Gorvel, Jean-Pierre

    2016-01-01

    Brucella is a Gram-negative facultative intracellular bacterium responsible for a chronic disease known as brucellosis, the most widespread re-emerging zoonosis worldwide. Establishment of a Th1-mediated immune response characterized by the production of IL-12 and IFNγ is essential to control the disease. Leukotrienes derived from arachidonic acid (AA) metabolism are known to negatively regulate a protective Th1 immune response against bacterial infections. Here, using genomics approaches we demonstrate that Brucella abortus strongly stimulates the prostaglandin (PG) pathway in dendritic cells (DC). We also show an induction of AA production by infected cells. This correlates with the expression of Ptgs2, a gene encoding the downstream cyclooxygenase-2 (COX-2) enzyme in infected DC. By comparing different infection routes (oral, intradermal, intranasal and conjunctival), we identified the intradermal inoculation route as the more potent in inducing Ptgs2 expression but also in inducing a local inflammatory response in the draining cervical lymph nodes (CLN). NS-398, a specific inhibitor of COX-2 enzymatic activity decreased B. melitensis burden in the CLN after intradermal infection. This effect was accompanied by a decrease of Il10 and a concomitant increase of Ifng expression. Altogether, these results suggest that Brucella has evolved to take advantage of the PG pathway in the harsh environment of the CLN in order to persist and subvert immune responses. This work also proposes that novel strategies to control brucellosis may include the use of COX-2 inhibitors. PMID:28018318

  13. Use of floating balls for reducing bacterial aerosol emissions from aeration in wastewater treatment processes.

    PubMed

    Hung, Hsueh Fen; Kuo, Yu Mei; Chien, Chih Ching; Chen, Chih Chieh

    2010-03-15

    The microorganism emissions from aeration in the wastewater treatment process may adversely affect air quality and human health. To control the liquid-to-air transport of microorganisms, commercially available balls were used and their control efficiencies were evaluated by a lab-scale aeration system. Escherichia coli as the test agent were aerosolized by the aeration system and size-fractionated E. coli-containing aerosol samples were collected by using an Andersen six-stage impactor with eosin methylene blue agar for subsequent culturing and enumeration of colonies. Aerosol samples were obtained without any control measure and with balls of four diameters (1.9, 2.9, 3.4 and 4.8 cm) in one, three and five layers covering the bubbling liquid surface. Experimental results showed that the control efficiencies of balls on bacterial aerosols varied from over 50% to nearly 100% under various control settings and substantially increased as the ball size decreased and the number of applied layers increased.

  14. Encapsulated Bifidobacteria reduced bacterial translocation in rats following hemorrhagic shock and resuscitation.

    PubMed

    Ruan, Xiangcai; Shi, Hanping; Xia, Gengfeng; Xiao, Ying; Dong, Jiaxi; Ming, Feiping; Wang, Shenming

    2007-10-01

    The aim of the present study was to determine the effects of peroral encapsulated Bifidobacteria on intestinal microflora, bacterial translocation (BT), plasma endotoxin, and ileal villi injury in a rat model of hemorrhagic shock. Sprague-Dawley rats were fed daily with three different diet supplements: phosphate buffered saline, Bifidobacteria (10(9) colon-forming units/day), or microencapsulated Bifidobacteria (10(9) colony-forming units/day). After 7 d of treatment, rats were anesthetized for hemorrhagic or sham shock. Then a laparotomy was performed to determine microbiological analysis of cecal content, BT to mesenteric lymph nodes, plasma endotoxin, and terminal ileal villous damage. In the hemorrhagic-shock model, rats pretreated with Bifidobacteria showed decreases in total aerobes in cecum, magnitude of total aerobes to BT, levels of plasma endotoxin, and percentage of ileal villous damage when compared with rats treated with phosphate buffered saline. Encapsulated Bifidobacteria induced greater decreases than intact Bifidobacteria in this model, except for no difference in percentage of ileal villous damage between the two groups. In addition, the incidence of BT was decreased in hemorrhagic rats pretreated with Bifidobacteria compared with control. However, the magnitude of total anaerobes and Bifidobacteria BT were similar among hemorrhagic-shocked rats receiving three different supplements. Bifidobacteria can be useful in preventing BT in hemorrhagic-shocked rats, and encapsulated Bifidobacteria can augment this effect further. Peroral administration of Bifidobacteria may be a favorable strategy to prevent sepsis and multiple organ dysfunction syndrome in hemorrhagic shock.

  15. Treatment of Helicobacter pylori infected mice with Bryophyllum pinnatum, a medicinal plant with antioxidant and antimicrobial properties, reduces bacterial load.

    PubMed

    Kouitcheu Mabeku, Laure Brigitte; Eyoum Bille, Bertrand; Tchouangueu, Thibau Flaurant; Nguepi, Eveline; Leundji, Hubert

    2017-12-01

    Bryophyllum pinnatum (Lam.) Kurz (Crassulaceae) is a plant known for its antiulcer properties. This study evaluates the anti-Helicobacter pylori activity of Bryophyllum pinnutum methanol extract with a mouse model and its antioxidant properties. Dried leaves of Bryophyllum pinnutum were extracted with methanol and ethyl acetate. Broth microdilution method was used to evaluate the anti-Helicobacter activity of extract samples in vitro. Swiss mice were inoculated with a suspension of Helicobacter pylori and divided into control group and four others that received 125, 250, 500 mg/kg of methanol extract or ciprofloxacin (500 mg/kg), respectively, for 7 days. Helicobacter pylori colonization and bacterial load of mouse stomach was assessed on day 1 and 7 post-treatment. The antioxidant activity of Bryophyllum pinnutum was evaluated through DPPH radical, hydroxyl radical and reducing power assay. Methanol extract showed a significant anti-Helicobacter activity with MIC and MBC values of 32 and 256 μg/mL, respectively. Bryophyllum pinnatum and ciprofloxacin reduced H. pylori colonization of gastric tissue from 100% to 17%. Bryophyllum pinnatum extract (85.91 ± 52.91 CFU) and standard (25.74 ± 16.15 CFU) also reduced significantly (p < 0.05) bacterial load of gastric mucosa as compared to untreated infected mice (11883 ± 1831 CFU). DPPH radical, hydroxyl radical and reducing power assays showed IC50 values of 25.31 ± 0.34, 55.94 ± 0.68 and 11.18 ± 0.74 μg/mL, respectively. The data suggest that the methanol extract of Bryophyllum pinnatum could inhibit Helicobacter pylori growth, and may also acts as an antioxidant to protect gastric mucosa against reactive oxygen species.

  16. Immunoglobulin M-enriched human intravenous immunoglobulins reduce leukocyte-endothelial cell interactions and attenuate microvascular perfusion failure in normotensive endotoxemia.

    PubMed

    Hoffman, Johannes N; Fertmann, Jan M; Vollmar, Brigitte; Laschke, Matthias W; Jauch, Karl W; Menger, Michael D

    2008-01-01

    Clinical studies indicate potential differences in the efficacy of immunoglobulin (Ig) preparations in patients with sepsis. A recent meta-analysis showed improved survival rates with IgM-enriched Igs. It was the objective of the present study to characterize microcirculatory actions of different clinically used Ig preparations in a rodent endotoxin model by intravital microscopy. Male Syrian golden hamsters 6 to 8 weeks old with a body weight of 60 to 80 g were investigated by intravital fluorescence microscopy. Endotoxemia was induced by administration of 2 mg/kg (i.v.) endotoxin (LPS, Escherichia coli). Two different Ig preparations containing IgM, IgA, and IgG (intravenous IgM group; n = 6; 5 mL Pentaglobin/kg body weight, i.v.) or exclusively IgG (intravenous IgG group; n = 5; 5 mL Flebogamma/kg body weight, i.v.) were applied 5 min before LPS. Saline-treated endotoxemic animals served as controls (control; n = 8). In controls, LPS induced massive leukocyte-endothelial cell interactions, pronounced microvascular leakage, a decrease of systemic platelet count, and distinct capillary perfusion failure (P < 0.05). Both intravenous IgM and IgG reduced venular leakage (P< 0.05) and ameliorated the decrease in platelet count (P < 0.05). Of interest, intravenous IgM was capable of significantly (P< 0.05) reducing leukocyte adhesion in venules. This was associated with normalization of capillary perfusion at 24 h of endotoxemia, whereas intravenous IgG could not prevent LPS-mediated microvascular perfusion failure. We demonstrate that IgM-enriched Igs are superior to IgG alone in attenuating LPS-induced leukocytic inflammation and microcirculatory dysfunction. Our findings can explain better efficacy of IgM-enriched Igs in patients with severe sepsis.

  17. Characterization of bromate-reducing bacterial isolates and their potential for drinking water treatment

    USDA-ARS?s Scientific Manuscript database

    The objective of the current study was to isolate and characterize several bromatereducing bacteria and to examine their potential for bioaugmentation to a drinking water treatment process. Fifteen bromate-reducing bacteria were isolated from three sources. According to 16S rRNA gene sequencing, the...

  18. Effect of cooking method on the fatty acid content of reduced-fat and PUFA-enriched pork patties formulated with a konjac-based oil bulking system.

    PubMed

    Salcedo-Sandoval, Lorena; Cofrades, Susana; Ruiz-Capillas, Claudia; Jiménez-Colmenero, Francisco

    2014-12-01

    The effect of cooking methods (electric grilling and pan-frying in olive oil) on the composition of reduced-fat and reduced-fat/PUFA enriched pork patties was studied. Fat reduction was performed by replacing pork backfat (38% and 100%) with konjac gel and PUFA-enrichment by replacing pork backfat (49%) with a konjac-based oil bulking system stabilizing a healthier oil combination (olive, linseed and fish oils). Cooking losses (13%-27%) were affected (p<0.05) by formulation and cooking procedure. Compared with raw products, cooked samples had higher (p<0.05) concentrations of MUFAs and PUFAs (both n-3 and n-6); the difference was greater (p<0.05) in the pan-fried patties. Fatty acid retention was generally better in pan-fried than in grilled samples. When cooked, the PUFA levels in the medium-fat/improved sample containing the oil bulking system ranged between 1.4 and 1.6g/100g (0.47-0.51 from n-3 PUFAs), with EPA+DHA concentrations of around 75mg/100g. Konjac materials were successfully used to produce pork patties with a better lipid composition. Copyright © 2014. Published by Elsevier Ltd.

  19. Psychological stress-reducing effect of chocolate enriched with gamma-aminobutyric acid (GABA) in humans: assessment of stress using heart rate variability and salivary chromogranin A.

    PubMed

    Nakamura, H; Takishima, T; Kometani, T; Yokogoshi, H

    2009-01-01

    We studied the psychological stress-reducing effect of chocolate enriched with gamma-aminobutyric acid (GABA), on stress induced by an arithmetic task using changes of heart rate variability (HRV) and salivary chromogranin A (CgA). Subjects ingested 10 g chocolate enriched with 28 mg GABA (GABA chocolate); 15 min after the ingestion, subjects were assigned an arithmetic task for 15 min. After the task, an electrocardiogram was recorded and saliva samples were collected. HRV was determined from the electrocardiogram, and the activity of the autonomic nervous system was estimated through HRV. The CgA concentration of all saliva samples, an index for acute psychological stress, was measured. From HRV, those taking GABA chocolate made a quick recovery to the normal state from the stressful state. The CgA value after the task in those taking GABA chocolate did not increased in comparison with that before ingestion. From these results, GABA chocolate was considered to have a psychological stress-reducing effect.

  20. Selenium-Containing Phycocyanin from Se-Enriched Spirulina platensis Reduces Inflammation in Dextran Sulfate Sodium-Induced Colitis by Inhibiting NF-κB Activation.

    PubMed

    Zhu, Chenghui; Ling, Qinjie; Cai, Zhihui; Wang, Yun; Zhang, Yibo; Hoffmann, Peter R; Zheng, Wenjie; Zhou, Tianhong; Huang, Zhi

    2016-06-22

    Selenium (Se) plays an important role in fine-tuning immune responses. Inflammatory bowel disease (IBD) involves hyperresponsive immunity of the digestive tract, and a low Se level might aggravate IBD progression; however, the beneficial effects of natural Se-enriched diets on IBD remain unknown. Previously, we developed high-yield Se-enriched Spirulina platensis (Se-SP) as an excellent organic nutritional Se source. Here we prepared Se-containing phycocyanin (Se-PC) from Se-SP and observed that Se-PC administration effectively reduced the extent of colitis in mouse induced by dextran sulfate sodium. Supplementation with Se-PC resulted in significant protective effects, including mitigation of body weight loss, bloody diarrhea, and colonic inflammatory damage. The anti-inflammatory effects of Se-PC supplementation were found to involve modulation of cytokines, including IL-6, TNF-α, MCP-1, and IL-10. Mechanistically, Se-PC inhibited the activation of macrophages by suppressing the nuclear translocation of NF-κB, which is involved in the transcription of these pro-inflammatory cytokines. These results together suggest potential benefits of Se-PC as a functional Se supplement to reduce the symptoms of IBD.

  1. Enrichment of sulfate-reducing bacteria and resulting mineral formation in media mimicking pore water metal ion concentrations and pH conditions of acidic pit lakes.

    PubMed

    Meier, Jutta; Piva, Angela; Fortin, Danielle

    2012-01-01

    Acid mine drainage sites are extreme environments with high acidity and metal ion concentrations. Under anoxic conditions, microbial sulfate reduction may trigger the formation of secondary minerals as a result of H2S production and pH increase. This process was studied in batch experiments with enrichment cultures from acidic sediments of a pit lake using growth media set at different pH values and containing elevated concentrations of Fe²⁺ and Al³⁺. At initial pH values of 5 and 6, sulfate reduction occurred shortly after inoculation. Sulfate- reducing bacteria affiliated to the genus Desulfosporosinus predominated the microbial communities as shown by 16S rRNA gene analysis performed at the end of the incubation. At initial pH values of 3 and 4, sulfate reduction and cell growth occurred only after an extended lag phase, however, at a higher rate than in the less acidic assays. At the end of the growth phase, enrichments were dominated by Thermodesulfobium spp. suggesting that these sulfate reducers were better adapted to acidic conditions. Iron sulfides in the bulk phase were common in all assays, but specific aluminum precipitates formed in close association with cell surfaces and may function as a detoxification mechanism of dissolved Al species at low pH.

  2. Azotobacter chroococcum as a potentially useful bacterial biofertilizer for cotton (Gossypium hirsutum): Effect in reducing N fertilization.

    PubMed

    Romero-Perdomo, Felipe; Abril, Jorge; Camelo, Mauricio; Moreno-Galván, Andrés; Pastrana, Iván; Rojas-Tapias, Daniel; Bonilla, Ruth

    2017-08-29

    The aim of this research was to evaluate whether the application of two plant growth-promoting (rhizo)bacteria might reduce nitrogen fertilization doses in cotton. We used strains Azotobacter chroococcum AC1 and AC10 for their proven ability to promote seed germination and cotton growth. These microorganisms were characterized by their plant growth-promoting activities. Then, we conducted a glasshouse study to evaluate the plant growth promoting ability of these strains with reduced doses of urea fertilization in cotton. Results revealed that both strains are capable of fixing nitrogen, solubilizing phosphorus, synthesizing indole compounds and producing hydrolytic enzymes. After 12 weeks, the glasshouse experiment showed that cotton growth was positively influenced due to bacterial inoculation with respect to chemical fertilization. Notably, we observed that microbial inoculation further influenced plant biomass (p<0.05) than nitrogen content. Co-inoculation, interestingly, exhibited a greater beneficial effect on plant growth parameters compared to single inoculation. Moreover, similar results without significant statistical differences were observed among bacterial co-inoculation plus 50% urea and 100% fertilization. These findings suggest that co-inoculation of A. chroococcum strains allow to reduce nitrogen fertilization doses up to 50% on cotton growth. Our results showed that inoculation with AC1 and AC10 represents a viable alternative to improve cotton growth while decreasing the N fertilizer dose and allows to alleviate the environmental deterioration related to N pollution. Copyright © 2017 Asociación Argentina de Microbiología. Publicado por Elsevier España, S.L.U. All rights reserved.

  3. Simultaneous sulfate reduction and copper removal by a PVA-immobilized sulfate reducing bacterial culture.

    PubMed

    Hsu, Hsiu-Feng; Jhuo, Yu-Sheng; Kumar, Mathava; Ma, Ying-Shih; Lin, Jih-Gaw

    2010-06-01

    The effect of a sulfate reducing bacteria immobilized in polyvinyl alcohol (PVA) on simultaneous sulfate reduction and copper removal was investigated. Batch experiments were designed using central composite design (CCD) with two parameters, i.e. the copper concentration (10-100mg/L), and the quantity of immobilized SRB in culture solution (19-235 mg of VSS/L). Response surface methodology (RSM) was used to model the experimental data, and to identify optimal conditions for the maximum sulfate reduction and copper removal. Under optimum condition, i.e. approximately 138.5mg VSS/L of sulfate reducing bacteria immobilized in PVA, and approximately 51.5mg/L of copper, the maximum sulfate reduction rate was 1.57 d(-1) as based on the first-order kinetic equation. The data demonstrate that immobilizing sulfate reducing bacteria in PVA can enhance copper removal and the resistance of the bacteria towards copper toxicity. (c) 2010 Elsevier Ltd. All rights reserved.

  4. Lactic acid and trisodium phosphate treatment of lamb breast to reduce bacterial contamination.

    PubMed

    Ramirez, A J; Acuff, G R; Lucia, L M; Savell, J W

    2001-09-01

    Lactic acid and trisodium phosphate (TSP) were evaluated for the ability to reduce Escherichia coli and aerobic plate counts (APCs) on lamb breasts that were inoculated with a lamb fecal paste. A 90-s water rinse was applied followed by either a 9-s (55 degrees C) 2% lactic acid spray, a 60-s (55 degrees C) 12% TSP dip, or a combined treatment of both lactic acid and TSP treatments. Lactic acid reduced E. coli and APCs by 1.6 log10/cm2, and TSP caused a 1.8-log10/cm2 reduction in E. coli and a 0.7-log10/cm2 reduction in APCs. Combined reductions by the lactic acid spray followed by the TSP dip were 1.8 and 1.5 log10/cm2 for E. coli and APCs, respectively. Lactic acid and trisodium phosphate, used alone or in combination, were effective in reducing numbers of E. coli and could be useful as pathogen intervention steps in lamb slaughter processing.

  5. Biodegradation of Various Aromatic Compounds by Enriched Bacterial Cultures: Part B--Nitrogen-, Sulfur-, and Oxygen-Containing Heterocyclic Aromatic Compounds.

    PubMed

    Oberoi, Akashdeep Singh; Philip, Ligy; Bhallamudi, S Murty

    2015-07-01

    Present study focused on the biodegradation of various heterocyclic nitrogen, sulfur, and oxygen (NSO) compounds using naphthalene-enriched culture. Target compounds in the study were pyridine, quinoline, benzothiophene, and benzofuran. Screening studies were carried out using different microbial consortia enriched with specific polycyclic aromatic hydrocarbon (PAH) and NSO compounds. Among different microbial consortia, naphthalene-enriched culture was the most efficient consortium based on high substrate degradation rate. Substrate degradation rate with naphthalene-enriched culture followed the order pyridine > quinoline > benzofuran > benzothiophene. Benzothiophene and benzofuran were found to be highly recalcitrant pollutants. Benzothiophene could not be biodegraded when concentration was above 50 mg/l. It was observed that 2-(1H)-quinolinone, benzothiophene-2-one, and benzofuran-2,3-dione were formed as metabolic intermediates during biodegradation of quinoline, benzothiophene, and benzofuran, respectively. Quinoline-N and pyridine-N were transformed into free ammonium ions during the biodegradation process. Biodegradation pathways for various NSO compounds are proposed. Monod inhibition model was able to simulate single substrate biodegradation kinetics satisfactorily. Benzothiophene and benzofuran biodegradation kinetics, in presence of acetone, was simulated using a generalized multi-substrate model.

  6. Characterization of bacterial diversity in an atrazine degrading enrichment culture and degradation of atrazine, cyanuric acid and biuret in industrial wastewater.

    PubMed

    Dutta, Anirban; Vasudevan, Venugopal; Nain, Lata; Singh, Neera

    2016-01-01

    An enrichment culture was used to study atrazine degradation in mineral salt medium (MSM) (T1), MSM+soil extract (1:1, v/v) (T2) and soil extract (T3). Results suggested that enrichment culture required soil extract to degrade atrazine, as after second sequential transfer only partial atrazine degradation was observed in T1 treatment while atrazine was completely degraded in T2 and T3 treatments even after fourth transfer. Culture independent polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE) technique confirmed selective enrichment of genus Bacillus along with Pseudomonas and Burkholderia. Degradation of atrazine/metabolites in the industrial wastewater was studied at different initial concentrations of the contaminants [wastewater-water (v/v) ratio: T1, 1:9; T2, 2:8; T3, 3:7; T4, 5:5 and T5, undiluted effluent]. The initial concentrations of atrazine, cyanuric acid and biuret ranged between 5.32 and 53.92 µg mL(-1), 265.6 and 1805.2 µg mL(-1) and 1.85 and 16.12 µg mL(-1), respectively. The enrichment culture was able to completely degrade atrazine, cyanuric acid and biuret up to T4 treatment, while no appreciable degradation of contaminants was observed in the undiluted effluent (T5). Inability of enrichment culture to degrade atrazine/metabolites might be due to high concentrations of cyanuric acid. Therefore, a separate study on cyanuric acid degradation suggested: (i) no appreciable cyanuric acid degradation with accumulation of an unidentified metabolite in the medium where cyanuric acid was supplemented as the sole source of carbon and nitrogen; (ii) partial cyanuric acid degradation with accumulation of unidentified metabolite in the medium containing additional nitrogen source; and (iii) complete cyanuric acid degradation in the medium supplemented with an additional carbon source. This unidentified metabolite observed during cyanuric acid degradation and also detected in the enrichment culture inoculated wastewater samples

  7. Nitrate stimulation of indigenous nitrate-reducing, sulfide-oxidising bacterial community in wastewater anaerobic biofilms.

    PubMed

    Garcia-de-Lomas, Juan; Corzo, Alfonso; Carmen Portillo, M; Gonzalez, Juan M; Andrades, Jose A; Saiz-Jimenez, Cesáreo; Garcia-Robledo, Emilio

    2007-07-01

    The role of the nitrate-reducing, sulfide-oxidising bacteria (NR-SOB) in the nitrate-mediated inhibition of sulfide net production by anaerobic wastewater biofilms was analyzed in two experimental bioreactors, continuously fed with the primary effluent of a wastewater treatment plant, one used as control (BRC) and the other one supplemented with nitrate (BRN). This study integrated information from H(2)S and pH microelectrodes, RNA-based molecular techniques, and the time course of biofilm growth and bioreactors water phase. Biofilms were a net source of sulfide for the water phase (2.01 micromol S(2-)(tot)m(-2)s(-1)) in the absence of nitrate dosing. Nitrate addition effectively led to the cessation of sulfide release from biofilms despite which a low rate of net sulfate reduction activity (0.26 micromol S(2-)(tot)m(-2)s(-1)) persisted at a deep layer within the biofilm. Indigenous NR-SOB including Thiomicrospira denitrificans, Arcobacter sp., and Thiobacillus denitrificans were stimulated by nitrate addition resulting in the elimination of most sulfide from the biofilms. Active sulfate reducing bacteria (SRB) represented comparable fractions of total metabolically active bacteria in the libraries obtained from BRN and BRC. However, we detected changes in the taxonomic composition of the SRB community suggesting its adaptation to a higher level of NR-SOB activity in the presence of nitrate.

  8. Bacterial and yeast chaperones reduce both aggregate formation and cell death in mammalian cell models of Huntington's disease

    PubMed Central

    Carmichael, Jenny; Chatellier, Jean; Woolfson, Adrian; Milstein, César; Fersht, Alan R.; Rubinsztein, David C.

    2000-01-01

    Huntington's disease (HD) is an autosomal dominant neurodegenerative condition caused by expansions of more than 35 uninterrupted CAG repeats in exon 1 of the huntingtin gene. The CAG repeats in HD and the other seven known diseases caused by CAG codon expansions are translated into long polyglutamine tracts that confer a deleterious gain of function on the mutant proteins. Intraneuronal inclusions comprising aggregates of the relevant mutant proteins are found in the brains of patients with HD and related diseases. It is crucial to determine whether the formation of inclusions is directly pathogenic, because a number of studies have suggested that aggregates may be epiphenomena or even protective. Here, we show that fragments of the bacterial chaperone GroEL and the full-length yeast heat shock protein Hsp104 reduce both aggregate formation and cell death in mammalian cell models of HD, consistent with a causal link between aggregation and pathology. PMID:10920207

  9. Bacterial attachment and biofilm formation on surfaces are reduced by small-diameter nanoscale pores: how small is small enough?

    PubMed Central

    Feng, Guoping; Cheng, Yifan; Wang, Shu-Yi; Borca-Tasciuc, Diana A; Worobo, Randy W; Moraru, Carmen I

    2015-01-01

    Background/Objectives: Prevention of biofilm formation by bacteria is of critical importance to areas that directly affect human health and life including medicine, dentistry, food processing and water treatment. This work showcases an effective and affordable solution for reducing attachment and biofilm formation by several pathogenic bacteria commonly associated with foodborne illnesses and medical infections. Methods: Our approach exploits anodisation to create alumina surfaces with cylindrical nanopores with diameters ranging from 15 to 100 nm, perpendicular to the surface. The anodic surfaces were evaluated for attachment by Escherichia coli, Listeria monocytogenes, Staphylococcus aureus and Staphylococcus epidermidis. Cell–surface interaction forces were calculated and related to attachment. Results: We found that anodic alumina surfaces with pore diameters of 15 and 25 nm were able to effectively minimise bacterial attachment or biofilm formation by all the microorganisms tested. Using a predictive physicochemical approach on the basis of the extended Derjaguin and Landau, Verwey and Overbeek (XDLVO) theory, we attributed the observed effects largely to the repulsive forces, primarily electrostatic and acid–base forces, which were greatly enhanced by the large surface area originating from the high density, small-diameter pores. We also demonstrate how this predictive approach could be used to optimise different elements of surface topography, particularly pore diameter and density, for further enhancing the observed bacteria-repelling effects. Conclusions: We demonstrate that anodic nanoporous surfaces can effectively reduce bacterial attachment. These findings are expected to have immediate, far-reaching implications and commercial applications, primarily in health care and the food industry. PMID:28721236

  10. Effects of mimosine on Wolbachia in mosquito cells: cell cycle suppression reduces bacterial abundance.

    PubMed

    Fallon, Ann M

    2015-10-01

    The plant allelochemical L-mimosine (β-[N-(3-hydroxy-4-pyridone)]-α-aminopropionic acid; leucenol) resembles the nonessential amino acid, tyrosine. Because the obligate intracellular alphaproteobacterium, Wolbachia pipientis, metabolizes amino acids derived from host cells, the effects of mimosine on infected and uninfected mosquito cells were investigated. The EC50 for mimosine was 6-7 μM with Aedes albopictus C7-10 and C/wStr cell lines, and was not influenced by infection status. Mosquito cells responded to concentrations of mimosine substantially lower than those used to synchronize the mammalian cell cycle; at concentrations of 30-35 μM, mimosine reversibly arrested the mosquito cell cycle at the G1/S boundary and inhibited growth of Wolbachia strain wStr. Although lower concentrations of mimosine slightly increased wStr abundance, concentrations that suppressed the cell cycle reduced Wolbachia levels.

  11. Expression of a bacterial 3-dehydroshikimate dehydratase reduces lignin content and improves biomass saccharification efficiency

    DOE PAGES

    Eudes, Aymerick; Sathitsuksanoh, Noppadon; Baidoo, Edward E. K.; ...

    2015-01-13

    Lignin confers recalcitrance to plant biomass used as feedstocks in agro-processing industries or as source of renewable sugars for the production of bioproducts. The metabolic steps for the synthesis of lignin building blocks belong to the shikimate and phenylpropanoid pathways. Genetic engineering efforts to reduce lignin content typically employ gene knockout or gene silencing techniques to constitutively repress one of these metabolic pathways. Recently, new strategies have emerged offering better spatiotemporal control of lignin deposition, including the expression of enzymes that interfere with the normal process for cell wall lignification. In this study, we report that expression of a 3-dehydroshikimatemore » dehydratase (QsuB from Corynebacterium glutamicum) reduces lignin deposition in Arabidopsis cell walls. QsuB was targeted to the plastids to convert 3-dehydroshikimate – an intermediate of the shikimate pathway – into protocatechuate. Compared to wild-type plants, lines expressing QsuB contain higher amounts of protocatechuate, p-coumarate, p-coumaraldehyde and p-coumaryl alcohol, and lower amounts of coniferaldehyde, coniferyl alcohol, sinapaldehyde and sinapyl alcohol. 2D-NMR spectroscopy and pyrolysis-gas chromatography/mass spectrometry (pyro-GC/MS) reveal an increase of p-hydroxyphenyl units and a reduction of guaiacyl units in the lignin of QsuB lines. Size-exclusion chromatography indicates a lower degree of lignin polymerization in the transgenic lines. Therefore, our data show that the expression of QsuB primarily affects the lignin biosynthetic pathway. Finally, biomass from these lines exhibits more than a twofold improvement in saccharification efficiency. We conclude that the expression of QsuB in plants, in combination with specific promoters, is a promising gain-of-function strategy for spatiotemporal reduction of lignin in plant biomass.« less

  12. Expression of a bacterial 3-dehydroshikimate dehydratase reduces lignin content and improves biomass saccharification efficiency.

    PubMed

    Eudes, Aymerick; Sathitsuksanoh, Noppadon; Baidoo, Edward E K; George, Anthe; Liang, Yan; Yang, Fan; Singh, Seema; Keasling, Jay D; Simmons, Blake A; Loqué, Dominique

    2015-12-01

    Lignin confers recalcitrance to plant biomass used as feedstocks in agro-processing industries or as source of renewable sugars for the production of bioproducts. The metabolic steps for the synthesis of lignin building blocks belong to the shikimate and phenylpropanoid pathways. Genetic engineering efforts to reduce lignin content typically employ gene knockout or gene silencing techniques to constitutively repress one of these metabolic pathways. Recently, new strategies have emerged offering better spatiotemporal control of lignin deposition, including the expression of enzymes that interfere with the normal process for cell wall lignification. In this study, we report that expression of a 3-dehydroshikimate dehydratase (QsuB from Corynebacterium glutamicum) reduces lignin deposition in Arabidopsis cell walls. QsuB was targeted to the plastids to convert 3-dehydroshikimate - an intermediate of the shikimate pathway - into protocatechuate. Compared to wild-type plants, lines expressing QsuB contain higher amounts of protocatechuate, p-coumarate, p-coumaraldehyde and p-coumaryl alcohol, and lower amounts of coniferaldehyde, coniferyl alcohol, sinapaldehyde and sinapyl alcohol. 2D-NMR spectroscopy and pyrolysis-gas chromatography/mass spectrometry (pyro-GC/MS) reveal an increase of p-hydroxyphenyl units and a reduction of guaiacyl units in the lignin of QsuB lines. Size-exclusion chromatography indicates a lower degree of lignin polymerization in the transgenic lines. Therefore, our data show that the expression of QsuB primarily affects the lignin biosynthetic pathway. Finally, biomass from these lines exhibits more than a twofold improvement in saccharification efficiency. We conclude that the expression of QsuB in plants, in combination with specific promoters, is a promising gain-of-function strategy for spatiotemporal reduction of lignin in plant biomass.

  13. Reducing progoitrin and enriching glucoraphanin in Brassica napus seeds through silencing of the GSL-ALK gene family.

    PubMed

    Liu, Zheng; Hirani, Arvind H; McVetty, Peter B E; Daayf, Fouad; Quiros, Carlos F; Li, Genyi

    2012-05-01

    The hydrolytic products of glucosinolates in brassica crops are bioactive compounds. Some glucosinolate derivatives such as oxazolidine-2-thione from progoitrin in brassica oilseed meal are toxic and detrimental to animals, but some isothiocyanates such as sulforaphane are potent anti-carcinogens that have preventive effects on several human cancers. In most B. rapa, B. napus and B. juncea vegetables and oilseeds, there is no or only trace amount of glucoraphanin that is the precursor to sulforaphane. In this paper, RNA interference (RNAi) of the GSL-ALK gene family was used to down-regulate the expression of GSL-ALK genes in B. napus. The detrimental glucosinolate progoitrin was reduced by 65 %, and the beneficial glucosinolate glucoraphanin was increased to a relatively high concentration (42.6 μmol g(-1) seed) in seeds of B. napus transgenic plants through silencing of the GSL-ALK gene family. Therefore, there is potential application of the new germplasm with reduced detrimental glucosinolates and increased beneficial glucosinolates for producing improved brassica vegetables.

  14. Rhizoctonia solani infection reduced by bacterial and fungal combination of biofertilizer inoculums on organic potato

    NASA Astrophysics Data System (ADS)

    Papp, Orsolya; Biro, Borbala; Abod, Eva; Jung, Timea; Tirczka, Imre; Drexler, Dora

    2017-04-01

    Soil biological functioning and proper agrotechnical management are of key importance in organic agriculture. Beneficial microbial inoculums are used either as plant strengthening products (psp) or also as plant protecting products (ppp). Question is, which type of microbes should be applied to certain soil-plant systems to improve yield or reduce the damage of soil-born plant pathogens? Objective of present study was to compare the effect of inoculums 1 (PPS) with plant growth promoting bacterium strains (PGPR) and inoculums 2 (TPB) with potential biocontrol-agents, including both fungi and bacteria in organic potato production. Field experiment was conducted at the Organic Research Station of the Szent István University (Babatpuszta, Hungary). Growth and quality of potato (Solanum tuberosum var. Demon) was studied in the two microbial treatments and control, in four replicates. The PPS inoculums included Pseudomonas protegens, Ps. jessenii and Strenotrophomonas maltophylia, with plant growth promoting (PGPR) effect. TPB inoculums consisted of Trichoderma hartianum, Pseudomonas putida and Bacillus subtilis strains with main biocontrol effects of fungal and bacterium combination. Strains were incubated for 24 hours at 28 oC in a rotary shaker (140 rpm/min) up till cell-number about 1010 cell.ml-1 in Nutrient broth substrate, and mixed to prepare combined inoculums. Each potato tuber was treated by 10 ml inoculums that was added to 100 ml water respectively with only water at the controls. Yield of potato (10 plants/plot) and tuber quality, i.e. the percentage ratio of scabbiness (Streptomyces scabies), Rhizoctonia solani, and Fusarium sp. infection was estimated. Abundance of total aerob and anaerob heterotrophs, total microscopic fungi, pseudomonads bacteria and some sporeforming microorganisms was assessed by the most probable number (MPN) method in soil samples, collected four times during vegetation. Soil enzyme, dehydrogenase (DH) and fluorescein diacetate

  15. Evaluation of an ATP Assay to Quantify Bacterial Attachment to Surfaces in Reduced Gravity

    NASA Technical Reports Server (NTRS)

    Birmele, Michele N.; Roberson, Luke B.; Roberts, Michael S.

    2010-01-01

    Aim: To develop an assay to quantify the biomass of attached cells and biofilm formed on wetted surfaces in variable-gravity environments. Methods and Results: Liquid cultures of Pseudomonas aeruginosa were exposed to 30-35 brief cycles of hypergravity (< 2-g) followed by free fall (i.e., reduced gravity) equivalent to either lunar-g (i.e., 0.17 normal Earth gravity) or micro-g (i.e., < 0.001 normal Earth gravity) in an aircraft flying a series of parabolas. Over the course of two days of parabolic flight testing, 504 polymer or metal coupons were exposed to a stationary-phase population of P. aeruginosa strain ERC1 at a concentration of 1.0 x 10(exp 5) cells per milliliter. After the final parabola on each flight test day, half of the material coupon samples were treated with either 400 micro-g/L ionic silver fluoride (microgravity-exposed cultures) or 1% formalin (lunar-gravity-exposed cultures). The remaining sample coupons from each flight test day were not treated with a fixative. All samples were returned to the laboratory for analysis within 2 hours of landing, and all biochemical assays were completed within 8 hours of exposure to variable gravity. The intracellular ATP luminescent assay accurately reflected cell physiology compared to both cultivation-based and direct-count microscopy analyses. Cells exposed to variable gravity had more than twice as much intracellular ATP as control cells exposed only to normal Earth gravity.

  16. Salmonella Bacterial Monotherapy Reduces Autochthonous Prostate Tumor Burden in the TRAMP Mouse Model

    PubMed Central

    Kazmierczak, Robert A.; Gentry, Bettina; Mumm, Tyler; Schatten, Heide; Eisenstark, Abraham

    2016-01-01

    Attenuated Salmonella typhimurium injected in the circulatory system of mammals selectively targets tumors. Using weekly intraperitoneal injections of attenuated Salmonella strain CRC2631, we tested for regression and/or inhibition of tumor development in the TRAMP prostate tumor mouse model, which utilizes SV40 early region expression for autochthonous formation of prostate tumors that progress into metastatic, poorly differentiated prostatic carcinomas in an immunocompetent murine model. Thirteen weekly intraperitoneal administrations of 105–107 CFU CRC2631 into 10 week old mice were well tolerated by the TRAMP model. Sacrifice and histological analysis of TRAMP prostates at 22 weeks indicated that Salmonella monotherapy at administrated levels decrease visible tumor size (>29%) but did not significantly inhibit previously described SV40 expression-driven TRAMP tumor progression to undifferentiated carcinomas when histologically examined. In conclusion, this work demonstrates baseline results for CRC2631 Salmonella monotherapy using the immunocompetent TRAMP prostate tumor model in preparation for study of combination therapies that resolve autochthonously generated TRAMP prostate tumors, further reduce tumor size, or inhibit prostate tumor progression. PMID:27504973

  17. Isolation and characterization of a hydrocarbonoclastic bacterial enrichment from total petroleum hydrocarbon contaminated sediments: potential candidates for bioaugmentation in bio-based processes.

    PubMed

    Di Gregorio, Simona; Siracusa, Giovanna; Becarelli, Simone; Mariotti, Lorenzo; Gentini, Alessandro; Lorenzi, Roberto

    2016-06-01

    Seven hydrocarbonoclastic new bacterial isolates were isolated from dredged sediments of a river estuary in Italy. The sediments were contaminated by shipyard activities since decades, mainly ascribable to the exploitation of diesel oil as the fuel for recreational and commercial navigation of watercrafts. The bacterial isolates were able to utilize diesel oil as sole carbon source. Their metabolic capacities were evaluated by GC-MS analysis, with reference to the depletion of both the normal and branched alkanes, the nC18 fatty acid methyl ester and the unresolved complex mixture of organic compounds. They were taxonomically identified as different species of Stenotrophomonas and Pseudomonas spp. by the combination of amplified ribosomal DNA restriction analysis (ARDRA) and repetitive sequence-based PCR (REP-PCR) analysis. The metabolic activities of interest were analyzed both in relation to the single bacterial strains and to the combination of the latter as a multibacterial species system. After 6 days of incubation in mineral medium with diesel oil as sole carbon source, the Stenotrophomonas sp. M1 strain depleted 43-46 % of Cn-alkane from C28 up to C30, 70 % of the nC18 fatty acid methyl ester and the 46 % of the unresolved complex mixture of organic compounds. On the other hand, the Pseudomonas sp. NM1 strain depleted the 76 % of the nC18 fatty acid methyl ester, the 50 % of the unresolved complex mixture of organic compounds. The bacterial multispecies system was able to completely deplete Cn-alkane from C28 up to C30 and to deplete the 95 % of the unresolved complex mixture of organic compounds. The isolates, either as single strains and as a bacterial multispecies system, were proposed as candidates for bioaugmentation in bio-based processes for the decontamination of dredged sediments.

  18. ORGANIC INFLAMMATORY RESPONSE TO REDUCED PREOPERATIVE FASTING TIME, WITH A CARBOHYDRATE AND PROTEIN ENRICHED SOLUTION; A RANDOMIZED TRIAL.

    PubMed

    de Andrade Gagheggi Ravanini, Guilherme; Portari Filho, Pedro Eder; Abrantes Luna, Renato; Almeida de Oliveira, Vinicius

    2015-08-01

    Introducción: El objetivo de este estudio es la evaluación de la respuesta inflamatoria orgánica a la colecistectomía laparoscópica mediante vídeo con una reducción del tiempo de ayuno preoperatorio a 2h y empleando una solución enriquecida con carbohidratos y proteínas. Métodos: Se trata de un estudio aleatorizado, prospectivo con pacientes divididos en los dos grupos siguientes: grupo A, ayuno convencional y grupo B, ayuno abreviado de 2h con ingesta oral de una solución enriquecida con carbohidratos y proteínas. Antes de la ingesta de la solución, se hicieron mediciones de glucosa sérica, insulina, interleucina 1y TNF-α; también se realizaron mediciones durante la inducción de la anestesia y 4h después de la intervención quirúrgica. Resultados: Treinta y ocho pacientes completaron el estudio sin presentar complicaciones pulmonares relacionadas con el broncoaspirado. La varianza HOMA-IR postoperatoria fue superior en el grupo A (p = 0,001). Conclusión: La reducción del tiempo de ayuno preoperatorio a 2h, empleando soluciones enriquecidas con carbohidratos y proteínas, es segura, reduce la resistencia a la insulina, y no aumenta el riesgo de broncoaspirado.

  19. Green tea beverages enriched with catechins with a galloyl moiety reduce body fat in moderately obese adults: a randomized double-blind placebo-controlled trial.

    PubMed

    Kobayashi, Makoto; Kawano, Takanori; Ukawa, Yuuichi; Sagesaka, Yuko M; Fukuhara, Ikuo

    2016-01-01

    Objective To determine whether ingesting a green tea beverage enriched with catechins with a galloyl moiety during a meal reduces body fat in moderately obese adults. Design Randomized double-blind placebo-controlled study. Subjects A total of 126 obese subjects (25 ≤ body mass index < 30 kg m(-2)) were randomly assigned to a group receiving green tea beverages without catechins (placebo), or a group receiving green tea beverages with a low or high content of catechins with a galloyl moiety. Each subject ingested 500 mL bottled green tea beverages containing 25, 180, or 279.5 mg green tea catechins (0, 149.5, or 246.5 mg catechins with a galloyl moiety, respectively), at mealtimes for 12 weeks; the subjects were instructed to ingest the beverage during the meal that had the highest fat content on that day. Methods Anthropometric measurements and blood chemistry analysis were performed during the run-in period; at weeks 0, 4, 8, and 12 of the intake period; and at the end of the withdrawal period. Abdominal fat area was measured by computed tomography at weeks 0, 8, and 12 of the intake period and at the end of the withdrawal period. Results Both the low- and high-dose groups exhibited significant reductions in visceral and subcutaneous fat areas compared to the control group at 12 weeks post-intervention. Conclusion Ingestion of a green tea beverage enriched with catechins with a galloyl moiety during a high-fat meal reduces body fat in moderately obese adults.

  20. Enriched early life experiences reduce adult anxiety-like behavior in rats: a role for insulin-like growth factor 1.

    PubMed

    Baldini, Sara; Restani, Laura; Baroncelli, Laura; Coltelli, Maila; Franco, Roberta; Cenni, Maria Cristina; Maffei, Lamberto; Berardi, Nicoletta

    2013-07-10

    Early life experiences can affect brain development, contributing to shape interindividual differences in stress vulnerability and anxiety-like behavior. In rodents, high levels of maternal care have long-lasting positive effects on the behavior of the offspring and stress response; post-weaning rearing in an enriched environment (EE) or massage counteract the negative effects of maternal separation or prenatal stressors. We recently found that insulin-like growth factor 1 (IGF-1) is a key mediator of early EE or massage on brain development. Whether early enrichment of experience can induce long-lasting effects on anxiety-like behavior and whether IGF-1 is involved in these effects is not known. We assessed anxiety-like behavior by means of the elevated plus maze in control adult rats and in adult rats subjected to early EE or to massage. We found that both EE and massage reduced adult anxiety-like behavior. Early IGF-1 systemic injections in rat pups reared in standard condition mimic the effects of EE and massage, reducing anxiety-like behavior in the adult; blocking early IGF-1 action in massaged and EE animals prevents massage and EE effects. In EE and IGF-1-treated animals, we assessed the hippocampal expression of glucocorticoid receptors (GRs) at postnatal day 12 (P12) and P60, finding a significantly higher GR expression at P60 for both treatments. These results suggest that IGF-1 could be involved in mediating the long-lasting effects of early life experiences on vulnerability/resilience to stress in adults.

  1. Deferiprone Reduces Amyloid-β and Tau Phosphorylation Levels but not Reactive Oxygen Species Generation in Hippocampus of Rabbits Fed a Cholesterol-Enriched Diet

    PubMed Central

    Prasanthi, Jaya R.P.; Schrag, Matthew; Dasari, Bhanu; Marwarha, Gurdeep; Kirsch, Wolff M.; Ghribi, Othman

    2013-01-01

    Accumulation of amyloid-β (Aβ) peptide and the hyperphosphorylation of tau protein are major hallmarks of Alzheimer’s disease (AD). The causes of AD are not well known but a number of environmental and dietary factors are suggested to increase the risk of developing AD. Additionally, altered metabolism of iron may have a role in the pathogenesis of AD. We have previously demonstrated that cholesterol-enriched diet causes AD-like pathology with iron deposition in rabbit brain. However, the extent to which chelation of iron protects against this pathology has not been determined. In this study, we administered the iron chelator deferiprone in drinking water to rabbits fed with a 2% cholesterol diet for 12 weeks. We found that deferiprone (both at 10 and 50 mg/kg/day) significantly decreased levels of Aβ40 and Aβ42 as well as BACE1, the enzyme that initiates cleavage of amyloid-β protein precursor to yield Aβ. Deferiprone also reduced the cholesterol diet-induced increase in phosphorylation of tau but failed to reduce reactive oxygen species generation. While deferiprone treatment was not associated with any change in brain iron levels, it was associated with a significant reduction in plasma iron and cholesterol levels. These results demonstrate that deferiprone confers important protection against hypercholesterolemia-induced AD pathology but the mechanism(s) may involve reduction in plasma iron and cholesterol levels rather than chelation of brain iron. We propose that adding an antioxidant therapy to deferiprone may be necessary to fully protect against cholesterol-enriched diet-induced AD-like pathology. PMID:22406440

  2. Consumption of soy isoflavone enriched bread in men with prostate cancer is associated with reduced proinflammatory cytokines and immunosuppressive cells.

    PubMed

    Lesinski, Gregory B; Reville, Patrick K; Mace, Thomas A; Young, Gregory S; Ahn-Jarvis, Jennifer; Thomas-Ahner, Jennifer; Vodovotz, Yael; Ameen, Zeenath; Grainger, Elizabeth; Riedl, Kenneth; Schwartz, Steven; Clinton, Steven K

    2015-11-01

    We hypothesized that soy phytochemicals may have immunomodulatory properties that may affect prostate carcinogenesis and progression. A randomized, phase II trial was conducted in 32 patients with prostate cancer with asymptomatic biochemical recurrence but no measurable disease on standard staging studies. Patients were randomized to two slices of soy bread (34 mg isoflavones/slice) or soy bread containing almond powder daily as a source of β-glucosidase. Flow cytometry and bioplex assays were used to measure cytokines or immune cell phenotype in blood at baseline (day 0) and following intervention (day 56). Adequate blood samples were available at enrollment and day 56 and evaluated. Multiple plasma cytokines and chemokines were significantly decreased on day 56 versus baseline. Subgroup analysis indicated reduced TH1 (P = 0.028) and myeloid-derived suppressor cell (MDSC)-associated cytokines (P = 0.035). TH2 and TH17 cytokines were not significantly altered. Phenotypic analysis revealed no change in CD8(+) or CD4(+) T cells but showed increased CD56(+) natural killer (NK) cells (P = 0.038). The percentage of cells with a T regulatory cell phenotype (CD4(+)CD25(+)FoxP3(+)) was significantly decreased after 56 days of soy bread (P = 0.0136). Significantly decreased monocytic (CD33(+)HLADR(neg)CD14(+)) MDSC were observed in patients consuming soy bread (P = 0.0056). These data suggest that soy bread modulates systemic soluble and cellular biomarkers consistent with limiting inflammation and suppression of MDSCs. Additional studies to elucidate impact on the carcinogenic process or as a complement to immune-based therapy are required.

  3. A novel C5a-derived immunobiotic peptide reduces Streptococcus agalactiae colonization through targeted bacterial killing.

    PubMed

    Cavaco, Courtney K; Patras, Kathryn A; Zlamal, Jaime E; Thoman, Marilyn L; Morgan, Edward L; Sanderson, Sam D; Doran, Kelly S

    2013-11-01

    Streptococcus agalactiae (group B Streptococcus [GBS]) is a Gram-positive bacterium that colonizes the cervicovaginal tract in approximately 25% of healthy women. Although colonization is asymptomatic, GBS can be vertically transmitted to newborns peripartum, causing severe disease such as pneumonia and meningitis. Current prophylaxis, consisting of late gestation screening and intrapartum antibiotics, has failed to completely prevent transmission, and GBS remains a leading cause of neonatal sepsis and meningitis in the United States. Lack of an effective vaccine and emerging antibiotic resistance necessitate exploring novel therapeutic strategies. We have employed a host-directed immunomodulatory therapy using a novel peptide, known as EP67, derived from the C-terminal region of human complement component C5a. Previously, we have demonstrated in vivo that EP67 engagement of the C5a receptor (CD88) effectively limits staphylococcal infection by promoting cytokine release and neutrophil infiltration. Here, using our established mouse model of GBS vaginal colonization, we observed that EP67 treatment results in rapid clearance of GBS from the murine vagina. However, this was not dependent on functional neutrophil recruitment or CD88 signaling, as EP67 treatment reduced the vaginal bacterial load in mice lacking CD88 or the major neutrophil receptor CXCr2. Interestingly, we found that EP67 inhibits GBS growth in vitro and in vivo and that antibacterial activity was specific to Streptococcus species. Our work establishes that EP67-mediated clearance of GBS is likely due to direct bacterial killing rather than to enhanced immune stimulation. We conclude that EP67 may have potential as a therapeutic to control GBS vaginal colonization.

  4. The natural antimicrobial carvacrol inhibits quorum sensing in Chromobacterium violaceum and reduces bacterial biofilm formation at sub-lethal concentrations.

    PubMed

    Burt, Sara A; Ojo-Fakunle, Victoria T A; Woertman, Jenifer; Veldhuizen, Edwin J A

    2014-01-01

    The formation of biofilm by bacteria confers resistance to biocides and presents problems in medical and veterinary clinical settings. Here we report the effect of carvacrol, one of the major antimicrobial components of oregano oil, on the formation of biofilms and its activity on existing biofilms. Assays were carried out in polystyrene microplates to observe (a) the effect of 0-0.8 mM carvacrol on the formation of biofilms by selected bacterial pathogens over 24 h and (b) the effect of 0-8 mM carvacrol on the stability of pre-formed biofilms. Carvacrol was able to inhibit the formation of biofilms of Chromobacterium violaceum ATCC 12472, Salmonella enterica subsp. Typhimurium DT104, and Staphylococcus aureus 0074, while it showed no effect on formation of Pseudomonas aeruginosa (field isolate) biofilms. This inhibitory effect of carvacrol was observed at sub-lethal concentrations (<0.5 mM) where no effect was seen on total bacterial numbers, indicating that carvacrol's bactericidal effect was not causing the observed inhibition of biofilm formation. In contrast, carvacrol had (up to 8 mM) very little or no activity against existing biofilms of the bacteria described, showing that formation of the biofilm also confers protection against this compound. Since quorum sensing is an essential part of biofilm formation, the effect of carvacrol on quorum sensing of C. violaceum was also studied. Sub-MIC concentrations of carvacrol reduced expression of cviI (a gene coding for the N-acyl-L-homoserine lactone synthase), production of violacein (pigmentation) and chitinase activity (both regulated by quorum sensing) at concentrations coinciding with carvacrol's inhibiting effect on biofilm formation. These results indicate that carvacrol's activity in inhibition of biofilm formation may be related to the disruption of quorum sensing.

  5. Enriched Air Nitrox Breathing Reduces Venous Gas Bubbles after Simulated SCUBA Diving: A Double-Blind Cross-Over Randomized Trial.

    PubMed

    Souday, Vincent; Koning, Nick J; Perez, Bruno; Grelon, Fabien; Mercat, Alain; Boer, Christa; Seegers, Valérie; Radermacher, Peter; Asfar, Pierre

    2016-01-01

    To test the hypothesis whether enriched air nitrox (EAN) breathing during simulated diving reduces decompression stress when compared to compressed air breathing as assessed by intravascular bubble formation after decompression. Human volunteers underwent a first simulated dive breathing compressed air to include subjects prone to post-decompression venous gas bubbling. Twelve subjects prone to bubbling underwent a double-blind, randomized, cross-over trial including one simulated dive breathing compressed air, and one dive breathing EAN (36% O2) in a hyperbaric chamber, with identical diving profiles (28 msw for 55 minutes). Intravascular bubble formation was assessed after decompression using pulmonary artery pulsed Doppler. Twelve subjects showing high bubble production were included for the cross-over trial, and all completed the experimental protocol. In the randomized protocol, EAN significantly reduced the bubble score at all time points (cumulative bubble scores: 1 [0-3.5] vs. 8 [4.5-10]; P < 0.001). Three decompression incidents, all presenting as cutaneous itching, occurred in the air versus zero in the EAN group (P = 0.217). Weak correlations were observed between bubble scores and age or body mass index, respectively. EAN breathing markedly reduces venous gas bubble emboli after decompression in volunteers selected for susceptibility for intravascular bubble formation. When using similar diving profiles and avoiding oxygen toxicity limits, EAN increases safety of diving as compared to compressed air breathing. ISRCTN 31681480.

  6. Enriched Air Nitrox Breathing Reduces Venous Gas Bubbles after Simulated SCUBA Diving: A Double-Blind Cross-Over Randomized Trial

    PubMed Central

    Souday, Vincent; Koning, Nick J.; Perez, Bruno; Grelon, Fabien; Mercat, Alain; Boer, Christa; Seegers, Valérie; Radermacher, Peter; Asfar, Pierre

    2016-01-01

    Objective To test the hypothesis whether enriched air nitrox (EAN) breathing during simulated diving reduces decompression stress when compared to compressed air breathing as assessed by intravascular bubble formation after decompression. Methods Human volunteers underwent a first simulated dive breathing compressed air to include subjects prone to post-decompression venous gas bubbling. Twelve subjects prone to bubbling underwent a double-blind, randomized, cross-over trial including one simulated dive breathing compressed air, and one dive breathing EAN (36% O2) in a hyperbaric chamber, with identical diving profiles (28 msw for 55 minutes). Intravascular bubble formation was assessed after decompression using pulmonary artery pulsed Doppler. Results Twelve subjects showing high bubble production were included for the cross-over trial, and all completed the experimental protocol. In the randomized protocol, EAN significantly reduced the bubble score at all time points (cumulative bubble scores: 1 [0–3.5] vs. 8 [4.5–10]; P < 0.001). Three decompression incidents, all presenting as cutaneous itching, occurred in the air versus zero in the EAN group (P = 0.217). Weak correlations were observed between bubble scores and age or body mass index, respectively. Conclusion EAN breathing markedly reduces venous gas bubble emboli after decompression in volunteers selected for susceptibility for intravascular bubble formation. When using similar diving profiles and avoiding oxygen toxicity limits, EAN increases safety of diving as compared to compressed air breathing. Trial Registration ISRCTN 31681480 PMID:27163253

  7. Variable ventilation improves pulmonary function and reduces lung damage without increasing bacterial translocation in a rat model of experimental pneumonia.

    PubMed

    de Magalhães, Raquel F; Samary, Cynthia S; Santos, Raquel S; de Oliveira, Milena V; Rocha, Nazareth N; Santos, Cintia L; Kitoko, Jamil; Silva, Carlos A M; Hildebrandt, Caroline L; Goncalves-de-Albuquerque, Cassiano F; Silva, Adriana R; Faria-Neto, Hugo C; Martins, Vanessa; Capelozzi, Vera L; Huhle, Robert; Morales, Marcelo M; Olsen, Priscilla; Pelosi, Paolo; de Abreu, Marcelo Gama; Rocco, Patricia R M; Silva, Pedro L

    2016-11-25

    Variable ventilation has been shown to improve pulmonary function and reduce lung damage in different models of acute respiratory distress syndrome. Nevertheless, variable ventilation has not been tested during pneumonia. Theoretically, periodic increases in tidal volume (VT) and airway pressures might worsen the impairment of alveolar barrier function usually seen in pneumonia and could increase bacterial translocation into the bloodstream. We investigated the impact of variable ventilation on lung function and histologic damage, as well as markers of lung inflammation, epithelial and endothelial cell damage, and alveolar stress, and bacterial translocation in experimental pneumonia. Thirty-two Wistar rats were randomly assigned to receive intratracheal of Pseudomonas aeruginosa (PA) or saline (SAL) (n = 16/group). After 24-h, animals were anesthetized and ventilated for 2 h with either conventional volume-controlled (VCV) or variable volume-controlled ventilation (VV), with mean VT = 6 mL/kg, PEEP = 5cmH2O, and FiO2 = 0.4. During VV, tidal volume varied randomly with a coefficient of variation of 30% and a Gaussian distribution. Additional animals assigned to receive either PA or SAL (n = 8/group) were not ventilated (NV) to serve as controls. In both SAL and PA, VV improved oxygenation and lung elastance compared to VCV. In SAL, VV decreased interleukin (IL)-6 expression compared to VCV (median [interquartile range]: 1.3 [0.3-2.3] vs. 5.3 [3.6-7.0]; p = 0.02) and increased surfactant protein-D expression compared to NV (2.5 [1.9-3.5] vs. 1.2 [0.8-1.2]; p = 0.0005). In PA, compared to VCV, VV reduced perivascular edema (2.5 [2.0-3.75] vs. 6.0 [4.5-6.0]; p < 0.0001), septum neutrophils (2.0 [1.0-4.0] vs. 5.0 [3.3-6.0]; p = 0.0008), necrotizing vasculitis (3.0 [2.0-5.5] vs. 6.0 [6.0-6.0]; p = 0.0003), and ultrastructural lung damage scores (16 [14-17] vs. 24 [14-27], p < 0.0001). Blood colony-forming-unit (CFU) counts

  8. Geo-Chip analysis reveals reduced functional diversity of the bacterial community at a dumping site for dredged Elbe sediment.

    PubMed

    Störmer, Rebecca; Wichels, Antje; Gerdts, Gunnar

    2013-12-15

    The dumping of dredged sediments represents a major stressor for coastal ecosystems. The impact on the ecosystem function is determined by its complexity not easy to assess. In the present study, we evaluated the potential of bacterial community analyses to act as ecological indicators in environmental monitoring programmes. We investigated the functional structure of bacterial communities, applying functional gene arrays (GeoChip4.2). The relationship between functional genes and environmental factors was analysed using distance-based multivariate multiple regression. Apparently, both the function and structure of the bacterial communities are impacted by dumping activities. The bacterial community at the dumping centre displayed a significant reduction of its entire functional diversity compared with that found at a reference site. DDX compounds separated bacterial communities of the dumping site from those of un-impacted sites. Thus, bacterial community analyses show great potential as ecological indicators in environmental monitoring.

  9. Reduction of Sn-Bearing Iron Concentrate with Mixed H2/CO Gas for Preparation of Sn-Enriched Direct Reduced Iron

    NASA Astrophysics Data System (ADS)

    You, Zhixiong; Li, Guanghui; Wen, Peidan; Peng, Zhiwei; Zhang, Yuanbo; Jiang, Tao

    2017-02-01

    The development of manufacturing technology of Sn-bearing stainless steel inspires a novel concept for using Sn-bearing complex iron ore via reduction with mixed H2/CO gas to prepare Sn-enriched direct reduced iron (DRI). The thermodynamic analysis of the reduction process confirms the easy reduction of stannic oxide to metallic tin and the rigorous conditions for volatilizing SnO. Although the removal of tin is feasible by reduction of the pellet at 1223 K (950 °C) with mixed gas of 5 vol pct H2, 28.5 vol pct CO, and 66.5 vol pct CO2 (CO/(CO + CO2) = 30 pct), it is necessary that the pellet be further reduced for preparing DRI. In contrast, maintaining Sn in the metallic pellet is demonstrated to be a promising way to effectively use the ore. It is indicated that only 5.5 pct of Sn is volatilized when the pellet is reduced at 1223 K (950 °C) for 30 minutes with the mixed gas of 50 vol pct H2, 50 vol pct CO (CO/(CO + CO2) = 100 pct). A metallic pellet (Sn-bearing DRI) with Sn content of 0.293 pct, Fe metallization of 93.5 pct, and total iron content of 88.2 pct is prepared as a raw material for producing Sn-bearing stainless steel. The reduced tin in the Sn-bearing DRI either combines with metallic iron to form Sn-Fe alloy or it remains intact.

  10. Reduction of Sn-Bearing Iron Concentrate with Mixed H2/CO Gas for Preparation of Sn-Enriched Direct Reduced Iron

    NASA Astrophysics Data System (ADS)

    You, Zhixiong; Li, Guanghui; Wen, Peidan; Peng, Zhiwei; Zhang, Yuanbo; Jiang, Tao

    2017-06-01

    The development of manufacturing technology of Sn-bearing stainless steel inspires a novel concept for using Sn-bearing complex iron ore via reduction with mixed H2/CO gas to prepare Sn-enriched direct reduced iron (DRI). The thermodynamic analysis of the reduction process confirms the easy reduction of stannic oxide to metallic tin and the rigorous conditions for volatilizing SnO. Although the removal of tin is feasible by reduction of the pellet at 1223 K (950 °C) with mixed gas of 5 vol pct H2, 28.5 vol pct CO, and 66.5 vol pct CO2 (CO/(CO + CO2) = 30 pct), it is necessary that the pellet be further reduced for preparing DRI. In contrast, maintaining Sn in the metallic pellet is demonstrated to be a promising way to effectively use the ore. It is indicated that only 5.5 pct of Sn is volatilized when the pellet is reduced at 1223 K (950 °C) for 30 minutes with the mixed gas of 50 vol pct H2, 50 vol pct CO (CO/(CO + CO2) = 100 pct). A metallic pellet (Sn-bearing DRI) with Sn content of 0.293 pct, Fe metallization of 93.5 pct, and total iron content of 88.2 pct is prepared as a raw material for producing Sn-bearing stainless steel. The reduced tin in the Sn-bearing DRI either combines with metallic iron to form Sn-Fe alloy or it remains intact.

  11. Isolation and characterization of a mesophilic heavy-metals-tolerant sulfate-reducing bacterium Desulfomicrobium sp. from an enrichment culture using phosphogypsum as a sulfate source.

    PubMed

    Azabou, Samia; Mechichi, Tahar; Patel, Bharat K C; Sayadi, Sami

    2007-02-09

    A sulfate-reducing bacterium, was isolated from a 6 month trained enrichment culture in an anaerobic media containing phosphogypsum as a sulfate source, and, designated strain SA2. Cells of strain SA2 were rod-shaped, did not form spores and stained Gram-negative. Phylogenetic analysis of the 16S rRNA gene sequence of the isolate revealed that it was related to members of the genus Desulfomicrobium (average sequence similarity of 98%) with Desulfomicrobium baculatum being the most closely related (sequence similarity of 99%). Strain SA2 used thiosulfate, sulfate, sulfite and elemental sulfur as electron acceptors and produced sulfide. Strain SA2 reduced sulfate contained in 1-20g/L phosphogypsum to sulfide with reduction of sulfate contained in 2g/L phosphogypsum being the optimum concentration. Strain SA2 grew with metalloid, halogenated and non-metal ions present in phosphogypsum and with added high concentrations of heavy metals (125ppm Zn and 100ppm Ni, W, Li and Al). The relative order for the inhibitory metal concentrations, based on the IC(50) values, was Cu, Te>Cd>Fe, Co, Mn>F, Se>Ni, Al, Li>Zn.

  12. Novel process of fermenting black soybean [Glycine max (L.) Merrill] yogurt with dramatically reduced flatulence-causing oligosaccharides but enriched soy phytoalexins.

    PubMed

    Feng, Shengbao; Saw, Chin Lee; Lee, Yuan Kun; Huang, Dejian

    2008-11-12

    Black soybeans [Glycine max (L.) Merrill] were germinated under fungal stress with food grade R. oligosporus for 3 days and were homogenized and fermented with lactic acid bacteria (LAB) to produce soy yogurt. Fungal stress led to the generation of oxylipins [oxooctadecadienoic acids (KODES) isomers and their respective glyceryl esters] and glyceollins--a type of phytoalexins unique to soybeans. In soy yogurt, the concentrations of total KODES and total glyceollins were 0.678 mg/g (dry matter) and 0.953 mg/g, respectively. The concentrations of other isoflavones (mainly genistein and daidzein and their derivatives) in soy yogurt remained largely unchanged after the processes compared with the control soy yogurt. Germination of black soybean under fungal stress for 3 days was sufficient to reduce stachyose and raffinose (which cause flatulence) by 92 and 80%, respectively. With a pH value of 4.42, a lactic acid content of 0.262%, and a maximum viable cell count of 2.1 x 10 (8) CFU/mL in the final soy yogurt, soy milk from germinated soybeans under fungal stress was concluded to be a suitable medium for yogurt-making. The resulting soy yogurt had significantly altered micronutrient profiles with significantly reduced oligosaccharides and enriched glyceollins.

  13. Inhibition of acyl-CoA cholesterol O-acyltransferase reduces the cholesteryl ester enrichment of atherosclerotic lesions in the Yucatan micropig.

    PubMed

    Bocan, T M; Mueller, S B; Uhlendorf, P D; Brown, E Q; Mazur, M J; Black, A E

    1993-03-01

    Atherosclerotic lesion development may be altered indirectly by regulating plasma cholesterol or directly by inhibition of acyl-CoA cholesterol O-acyltransferase (ACAT) within cells of the artery. Yucatan micropigs were meal-fed a 2% cholesterol, 8% peanut oil, 8% coconut oil purified diet for 1 month prior to administration of the potent, bioavailable ACAT inhibitor CI-976, and induction of atherosclerotic lesions by chronic endothelial damage. After 84-108 days of therapy, CI-976 decreased mean plasma VLDL-cholesterol 85-91% and cumulative VLDL-exposure (area under VLDL-time curve) by 65%. However, overall plasma total, LDL and HDL cholesterol and triglyceride levels were unchanged. CI-976 decreased liver cholesteryl ester (CE) content 65% without significantly affecting adrenal CE content. The CE content of the injured left femoral, left iliac and abdominal aorta and uninjured right femoral and iliac arteries and thoracic aorta was reduced 62-78% by CI-976. Systemic plasma CI-976 levels measured 24 h post-dose ranged from 2.26 to 4.05 micrograms/ml and significantly correlated with the reduction in both VLDL and vessel CE content. Thus, we conclude that inhibition of ACAT can blunt the cholesteryl ester enrichment of developing atherosclerotic lesions by preventing reesterification and storage of lipoprotein cholesterol within vascular cells and by reducing the plasma level and delivery to the arterial wall of such atherogenic lipoproteins as VLDL.

  14. Ambient UV-B exposure reduces the binding of ofloxacin with bacterial DNA gyrase and induces DNA damage mediated apoptosis.

    PubMed

    Singh, Jyoti; Dwivedi, Ashish; Mujtaba, Syed Faiz; Singh, Krishna P; Pal, Manish Kumar; Chopra, Deepti; Goyal, Shruti; Srivastav, Ajeet K; Dubey, Divya; Gupta, Shailendra K; Haldar, Chandana; Ray, Ratan Singh

    2016-04-01

    Ofloxacin (OFLX) is a broad spectrum antibiotic, which generates photo-products under sunlight exposure. Previous studies have failed to explain the attenuated anti-bacterial activity of OFLX. The study was extended to explore the unknown molecular mechanism of photogenotoxicity on human skin cell line (HaCaT) under environmental UV-B irradiation. Photochemically OFLX generates ROS and caused 2'-dGuO photodegradation. We have addressed the binding affinity of OFLX and its photo-products against DNA gyrase. Significant free radical generation such as (1)O2, O2(•-) and (•)OH reduces antioxidants and demonstrated the ROS mediated OFLX phototoxicity. However, the formation of micronuclei and CPDs showed photogenotoxic potential of OFLX. OFLX induced cell cycle arrest in sub-G1 peak. OFLX triggers apoptosis via permeabilization of mitochondrial membrane with the downregulation of anti-apoptotic Bcl-2 and caspase-3 whereas, upregulation of pro-apoptotic Bax and Cyto-C proteins. Our study illustrated that binding affinity of OFLX photo-products with DNA gyrase was mainly responsible for the attenuated antimicrobial activity. It was proved through molecular docking study. Thus, study suggests that sunlight exposure should avoid by drug users especially during peak hours for their safety from photosensitivity. Clinicians may guide patients regarding the safer use of photosensitive drugs during treatment. Copyright © 2016. Published by Elsevier Ltd.

  15. Insights into Nitrate-Reducing Fe(II) Oxidation Mechanisms through Analysis of Cell-Mineral Associations, Cell Encrustation, and Mineralogy in the Chemolithoautotrophic Enrichment Culture KS.

    PubMed

    Nordhoff, M; Tominski, C; Halama, M; Byrne, J M; Obst, M; Kleindienst, S; Behrens, S; Kappler, A

    2017-07-01

    Most described nitrate-reducing Fe(II)-oxidizing bacteria (NRFeOB) are mixotrophic and depend on organic cosubstrates for growth. Encrustation of cells in Fe(III) minerals has been observed for mixotrophic NRFeOB but not for autotrophic phototrophic and microaerophilic Fe(II) oxidizers. So far, little is known about cell-mineral associations in the few existing autotrophic NRFeOB. Here, we investigate whether the designated autotrophic Fe(II)-oxidizing strain (closely related to Gallionella and Sideroxydans) or the heterotrophic nitrate reducers that are present in the autotrophic nitrate-reducing Fe(II)-oxidizing enrichment culture KS form mineral crusts during Fe(II) oxidation under autotrophic and mixotrophic conditions. In the mixed culture, we found no significant encrustation of any of the cells both during autotrophic oxidation of 8 to 10 mM Fe(II) coupled to nitrate reduction and during cultivation under mixotrophic conditions with 8 to 10 mM Fe(II), 5 mM acetate, and 4 mM nitrate, where higher numbers of heterotrophic nitrate reducers were present. Two pure cultures of heterotrophic nitrate reducers (Nocardioides and Rhodanobacter) isolated from culture KS were analyzed under mixotrophic growth conditions. We found green rust formation, no cell encrustation, and only a few mineral particles on some cell surfaces with 5 mM Fe(II) and some encrustation with 10 mM Fe(II). Our findings suggest that enzymatic, autotrophic Fe(II) oxidation coupled to nitrate reduction forms poorly crystalline Fe(III) oxyhydroxides and proceeds without cellular encrustation while indirect Fe(II) oxidation via heterotrophic nitrate-reduction-derived nitrite can lead to green rust as an intermediate mineral and significant cell encrustation. The extent of encrustation caused by indirect Fe(II) oxidation by reactive nitrogen species depends on Fe(II) concentrations and is probably negligible under environmental conditions in most habitats.IMPORTANCE Most described nitrate-reducing

  16. Treatment of bacterial vaginosis in pregnancy in order to reduce the risk of spontaneous preterm delivery - a clinical recommendation.

    PubMed

    Haahr, Thor; Ersbøll, Anne S; Karlsen, Mona A; Svare, Jens; Sneider, Kirstine; Hee, Lene; Weile, Louise K; Ziobrowska-Bech, Agnes; Østergaard, Claus; Jensen, Jørgen S; Helmig, Rikke B; Uldbjerg, Niels

    2016-08-01

    Bacterial vaginosis (BV) is characterized by a dysbiosis of the vaginal microbiota with a depletion of Lactobacillus spp. In pregnancy, prevalence's between 7 and 30% have been reported depending on the study population and the definition. BV may be associated with an increased risk of spontaneous preterm delivery (sPTD). However, it is controversial whether or not BV-positive pregnant women will benefit from treatment to reduce the risk of sPTD. We could not identify any good-quality guideline addressing this issue. Consequently we aimed to produce this clinical recommendation based on GRADE. Systematic literature searches were conducted in the following databases: Guidelines International Network: G-I-N, Medline, Embase, The Cochrane Database of Systematic Reviews, Web of Science and http://www.clinicaltrials.gov from 1999 to 3 October 2014. Hence, nine guidelines, 34 reviews, 18 randomized controlled trials and 12 observational studies were included. The GRADE quality of evidence was consistently low or very low, primarily because none of the risk ratios (RR) for the risk of sPTD at <37 weeks were statistically significant. Concerning treatment with metronidazole, RR was 1.11 (95% CI 0.93-1.34) in low-risk pregnancies and 0.96 (95% CI 0.78-1.18) in high risk pregnancies. Concerning treatment with clindamycin at any gestational age, the RR was 0.87 (95% CI 0.73-1.05). This systematic review gives a strong recommendation against treatment with metronidazole and a weak recommendation against treatment with clindamycin to reduce the sPTD rate in both high-risk and low-risk pregnancies with BV. © 2016 Nordic Federation of Societies of Obstetrics and Gynecology.

  17. Filters Reduce the Risk of Bacterial Transmission from Contaminated Heated Humidifiers Used with CPAP for Obstructive Sleep Apnea

    PubMed Central

    Ortolano, Girolamo A.; Schaffer, Jeffrey; McAlister, Morven B.; Stanchfield, Ilia; Hill, Elizabeth; Vandenburgh, Liliana; Lewis, Michelle; John, Shirnett; Canonica, Francis P.; Cervia, Joseph S.

    2007-01-01

    Rationale: The treatment of choice for obstructive sleep apnea (OSA) is nasal continuous positive airway pressure (nCPAP) during sleep, but dryness of the upper airway compromises compliance. Heated humidifiers may mitigate such noncompliance; however, recent observations suggest that their use, particularly if not cleaned, increases the risk of respiratory infections. Humidifier water may be contaminated, but the long-held view that passive humidifiers cannot aerosolize water may obscure the perception of risk of infection. Objectives: This study challenges the long-held view that “passover” humidifiers do not aerosolize water. With such evidence, this study characterizes the performance of filters to reduce the potential risk of contamination. Methods: Heated humidifier water contaminated with bacteria was studied under conditions simulating week-long use of nCPAP for OSA. Results: Bacteria were recovered in 9 of 11 tests from the breathing tubes of CPAP devices fitted with heated humidifiers with water contaminated with Brevundimonas diminuta or Serratia marcescens. Recoverable bacteria ranged from tens to thousands of colony forming units when tested at air flow rates of 60 liters per minute for 90 minutes. Neither organism was recovered from the circuit tubing when a hydrophobic breathing-circuit filter was positioned between the humidifier and face-mask tubing with a commercially available nCPAP machine tested under simulated-use conditions. Conclusion: Data suggest that patients with OSA being treated with nCPAP fitted with humidifiers may be aerosolizing bacteria, putting them at risk for developing respiratory infections and that the use of a hydrophobic filter may attenuate the passage of microbes from contaminated humidifier water. Citation: Ortolano GA; Schaffer J; McAlister MB et al. Filters reduce the risk of bacterial transmission from contaminated heated humidifiers used with CPAP for obstructive sleep apnea. J Clin Sleep Med 2007;3(7):700–705

  18. Sonication reduces the attachment of Salmonella Typhimurium ATCC 14028 cells to bacterial cellulose-based plant cell wall models and cut plant material.

    PubMed

    Tan, Michelle S F; Rahman, Sadequr; Dykes, Gary A

    2017-04-01

    This study investigated the removal of bacterial surface structures, particularly flagella, using sonication, and examined its effect on the attachment of Salmonella Typhimurium ATCC 14028 cells to plant cell walls. S. Typhimurium ATCC 14028 cells were subjected to sonication at 20 kHz to remove surface structures without affecting cell viability. Effective removal of flagella was determined by staining flagella of sonicated cells with Ryu's stain and enumerating the flagella remaining by direct microscopic counting. The attachment of sonicated S. Typhimurium cells to bacterial cellulose-based plant cell wall models and cut plant material (potato, apple, lettuce) was then evaluated. Varying concentrations of pectin and/or xyloglucan were used to produce a range of bacterial cellulose-based plant cell wall models. As compared to the non-sonicated controls, sonicated S. Typhimurium cells attached in significantly lower numbers (between 0.5 and 1.0 log CFU/cm(2)) to all surfaces except to the bacterial cellulose-only composite without pectin and xyloglucan. Since attachment of S. Typhimurium to the bacterial cellulose-only composite was not affected by sonication, this suggests that bacterial surface structures, particularly flagella, could have specific interactions with pectin and xyloglucan. This study indicates that sonication may have potential applications for reducing Salmonella attachment during the processing of fresh produce.

  19. [Syndrome of bacterial overgrowth in patients with the reduced stomach acid secretion: some aspects of the diagnosis].

    PubMed

    Ardatskaia, M D; Loginov, V A; Minushkin, O N

    2014-01-01

    To study the frequency of occurrence of small intestinal bacterial overgrowth (SIBO) in GERD patients with reduced stomach acid secretion receiving long-term PPI treatment, and patients with chronic atrophic gastritis with reduced stomach acid secretion, using the hydrogen breath test (HBT) and studies of short-chain fatty acids (SCFA) in various biological substrates; compare the obtained results. There were 100 people surveyed: 1 group consisted of 40 patients with chronic atrophic gastritis (HG) with reduced stomach acid secretion; 2 group consisted of 60 patients of GERD in patients receiving PPI different duration (0-6 months, 6-12 months more than 12 months). All the patients were examined by a load of lactulose and research SCFA using gas-liquid chromatographic analysis (GC-analysis) in various biological substrates (duodenal secretion and feces). When performing HBT in patients with chronic atrophic gastritis frequency detection SIBO amounted to 57.5 per cent. In GERD patients receiving PPI SIBO was detected in 8.3% of cases (0-6 months of treatment), 21.7% (6-12 months of treatment), 61.6% (over 12 months). 15% of HG patients and 13.3% of GERD patients receiving PPI, with clinical manifestations of SIBO, the data turned out to be negative. The SCFA parameters in the duodenal secretion in patients with GERD during PPI therapy depending on the duration of the admission and in HG patients with reduced stomach acid secretion were studied, as well as in patients with clinical manifestations of SIBO depending on the data of HBT (+/-). We also studied SCFA parameters in patients with positive HBT results depending on time of registration of the increase of hydrogen concentration. It is established that the study of SCFA in the duodenal secretion is an important diagnostic SIBO test, which allows not only to detect increased activity of the microflora, but also to determine its tribal affiliation. In some cases, its information value exceeds the HBT. The study of

  20. Characterization of microbial associations with methanotrophic archaea and sulfate-reducing bacteria through statistical comparison of nested Magneto-FISH enrichments

    SciTech Connect

    Trembath-Reichert, Elizabeth; Case, David H.; Orphan, Victoria J.

    2016-04-18

    Methane seep systems along continental margins host diverse and dynamic microbial assemblages, sustained in large part through the microbially mediated process of sulfate-coupled Anaerobic Oxidation of Methane (AOM). This methanotrophic metabolism has been linked to consortia of anaerobic methane-oxidizing archaea (ANME) and sulfate-reducing bacteria (SRB). These two groups are the focus of numerous studies; however, less is known about the wide diversity of other seep associated microorganisms. We selected a hierarchical set of FISH probes targeting a range ofDeltaproteobacteriadiversity. Using the Magneto-FISH enrichment technique, we then magnetically captured CARD-FISH hybridized cells and their physically associated microorganisms from a methane seep sediment incubation. DNA from nested Magneto-FISH experiments was analyzed using Illumina tag 16S rRNA gene sequencing (iTag). Enrichment success and potential bias with iTag was evaluated in the context of full-length 16S rRNA gene clone libraries, CARD-FISH, functional gene clone libraries, and iTag mock communities. We determined commonly used Earth Microbiome Project (EMP) iTAG primers introduced bias in some common methane seep microbial taxa that reduced the ability to directly compare OTU relative abundances within a sample, but comparison of relative abundances between samples (in nearly all cases) and whole community-based analyses were robust. The iTag dataset was subjected to statistical co-occurrence measures of the most abundant OTUs to determine which taxa in this dataset were most correlated across all samples. In addition, many non-canonical microbial partnerships were statistically significant in our co-occurrence network analysis, most of which were not recovered with conventional clone library sequencing, demonstrating the utility of combining Magneto-FISH and iTag sequencing methods for hypothesis generation of associations within complex microbial communities. Network

  1. Characterization of microbial associations with methanotrophic archaea and sulfate-reducing bacteria through statistical comparison of nested Magneto-FISH enrichments

    PubMed Central

    Case, David H.

    2016-01-01

    Methane seep systems along continental margins host diverse and dynamic microbial assemblages, sustained in large part through the microbially mediated process of sulfate-coupled Anaerobic Oxidation of Methane (AOM). This methanotrophic metabolism has been linked to consortia of anaerobic methane-oxidizing archaea (ANME) and sulfate-reducing bacteria (SRB). These two groups are the focus of numerous studies; however, less is known about the wide diversity of other seep associated microorganisms. We selected a hierarchical set of FISH probes targeting a range of Deltaproteobacteria diversity. Using the Magneto-FISH enrichment technique, we then magnetically captured CARD-FISH hybridized cells and their physically associated microorganisms from a methane seep sediment incubation. DNA from nested Magneto-FISH experiments was analyzed using Illumina tag 16S rRNA gene sequencing (iTag). Enrichment success and potential bias with iTag was evaluated in the context of full-length 16S rRNA gene clone libraries, CARD-FISH, functional gene clone libraries, and iTag mock communities. We determined commonly used Earth Microbiome Project (EMP) iTAG primers introduced bias in some common methane seep microbial taxa that reduced the ability to directly compare OTU relative abundances within a sample, but comparison of relative abundances between samples (in nearly all cases) and whole community-based analyses were robust. The iTag dataset was subjected to statistical co-occurrence measures of the most abundant OTUs to determine which taxa in this dataset were most correlated across all samples. Many non-canonical microbial partnerships were statistically significant in our co-occurrence network analysis, most of which were not recovered with conventional clone library sequencing, demonstrating the utility of combining Magneto-FISH and iTag sequencing methods for hypothesis generation of associations within complex microbial communities. Network analysis pointed to many co

  2. Characterization of microbial associations with methanotrophic archaea and sulfate-reducing bacteria through statistical comparison of nested Magneto-FISH enrichments

    DOE PAGES

    Trembath-Reichert, Elizabeth; Case, David H.; Orphan, Victoria J.

    2016-04-18

    Methane seep systems along continental margins host diverse and dynamic microbial assemblages, sustained in large part through the microbially mediated process of sulfate-coupled Anaerobic Oxidation of Methane (AOM). This methanotrophic metabolism has been linked to consortia of anaerobic methane-oxidizing archaea (ANME) and sulfate-reducing bacteria (SRB). These two groups are the focus of numerous studies; however, less is known about the wide diversity of other seep associated microorganisms. We selected a hierarchical set of FISH probes targeting a range ofDeltaproteobacteriadiversity. Using the Magneto-FISH enrichment technique, we then magnetically captured CARD-FISH hybridized cells and their physically associated microorganisms from a methane seepmore » sediment incubation. DNA from nested Magneto-FISH experiments was analyzed using Illumina tag 16S rRNA gene sequencing (iTag). Enrichment success and potential bias with iTag was evaluated in the context of full-length 16S rRNA gene clone libraries, CARD-FISH, functional gene clone libraries, and iTag mock communities. We determined commonly used Earth Microbiome Project (EMP) iTAG primers introduced bias in some common methane seep microbial taxa that reduced the ability to directly compare OTU relative abundances within a sample, but comparison of relative abundances between samples (in nearly all cases) and whole community-based analyses were robust. The iTag dataset was subjected to statistical co-occurrence measures of the most abundant OTUs to determine which taxa in this dataset were most correlated across all samples. In addition, many non-canonical microbial partnerships were statistically significant in our co-occurrence network analysis, most of which were not recovered with conventional clone library sequencing, demonstrating the utility of combining Magneto-FISH and iTag sequencing methods for hypothesis generation of associations within complex microbial communities. Network analysis pointed

  3. Exogenous indirect photoinactivation of bacterial pathogens and indicators in water with natural and synthetic photosensitizers in simulated sunlight with reduced UVB.

    PubMed

    Maraccini, P A; Wenk, J; Boehm, A B

    2016-08-01

    To investigate the UVB-independent and exogenous indirect photoinactivation of eight human health-relevant bacterial species in the presence of photosensitizers. Eight bacterial species were exposed to simulated sunlight with greatly reduced UVB light intensity in the presence of three synthetic photosensitizers and two natural photosensitizers. Inactivation curves were fit with shoulder log-linear or first-order kinetic models, from which the presence of a shoulder and magnitude of inactivation rate constants were compared. Eighty-four percent reduction in the UVB light intensity roughly matched a 72-95% reduction in the overall bacterial photoinactivation rate constants in sensitizer-free water. With the UVB light mostly reduced, the exogenous indirect mechanism contribution was evident for most bacteria and photosensitizers tested, although most prominently with the Gram-positive bacteria. Results confirm the importance of UVB light in bacterial photoinactivation and, with the reduction of the UVB light intensity, that the Gram-positive bacteria are more vulnerable to the exogenous indirect mechanism than Gram-negative bacteria. UVB is the most important range of the sunlight spectrum for bacterial photoinactivation. In aquatic environments where photosensitizers are present and there is high UVB light attenuation, UVA and visible wavelengths can contribute to exogenous indirect photoinactivation. © 2016 The Society for Applied Microbiology.

  4. Sulfate-Reducing Bacterium Desulfovibrio desulfuricans ND132 as a Model for Understanding Bacterial Mercury Methylation▿†

    PubMed Central

    Gilmour, Cynthia C.; Elias, Dwayne A.; Kucken, Amy M.; Brown, Steven D.; Palumbo, Anthony V.; Schadt, Christopher W.; Wall, Judy D.

    2011-01-01

    We propose the use of Desulfovibrio desulfuricans ND132 as a model species for understanding the mechanism of microbial Hg methylation. Strain ND132 is an anaerobic dissimilatory sulfate-reducing bacterium (DSRB), isolated from estuarine mid-Chesapeake Bay sediments. It was chosen for study because of its exceptionally high rates of Hg methylation in culture and its metabolic similarity to the lost strain D. desulfuricans LS, the only organism for which methylation pathways have been partially defined. Strain ND132 is an incomplete oxidizer of short-chain fatty acids. It is capable of respiratory growth using fumarate as an electron acceptor, supporting growth without sulfide production. We used enriched stable Hg isotopes to show that ND132 simultaneously produces and degrades methylmercury (MeHg) during growth but does not produce elemental Hg. MeHg produced by cells is mainly excreted, and no MeHg is produced in spent medium. Mass balances for Hg and MeHg during the growth of cultures, including the distribution between filterable and particulate phases, illustrate how medium chemistry and growth phase dramatically affect Hg solubility and availability for methylation. The available information on Hg methylation among strains in the genus Desulfovibrio is summarized, and we present methylation rates for several previously untested species. About 50% of Desulfovibrio strains tested to date have the ability to produce MeHg. Importantly, the ability to produce MeHg is constitutive and does not confer Hg resistance. A 16S rRNA-based alignment of the genus Desulfovibrio allows the very preliminary assessment that there may be some evolutionary basis for the ability to produce MeHg within this genus. PMID:21515733

  5. The sulfate-reducing bacterium Desulfovibrio desulfuricans ND132 as a model for understanding bacterial mercury methylation

    SciTech Connect

    Gilmour, C C; Elias, Dwayne A; Kucken, A M; Brown, Steven D; Palumbo, Anthony Vito; Schadt, Christopher Warren; Wall, Judy D.

    2011-01-01

    We propose the use of Desulfovibrio desulfuricans ND132 as a model species for understanding the mechanism of microbial Hg methylation. Strain ND132 is an anaerobic dissimilatory sulfate-reducing bacterium (DSRB), isolated from estuarine mid-Chesapeake Bay sediments. It was chosen for study because of its exceptionally high rates of Hg methylation in culture and its metabolic similarity to the lost strain D. desulfuricans LS, the only organism for which methylation pathways have been partially defined. Strain ND132 is an incomplete oxidizer of short-chain fatty acids. It is capable of respiratory growth using fumarate as an electron acceptor, supporting growth without sulfide production. We used enriched stable Hg isotopes to show that ND132 simultaneously produces and degrades methylmercury (MeHg) during growth but does not produce elemental Hg. MeHg produced by cells is mainly excreted, and no MeHg is produced in spent medium. Mass balances for Hg and MeHg during the growth of cultures, including the distribution between filterable and particulate phases, illustrate how medium chemistry and growth phase dramatically affect Hg solubility and availability for methylation. The available information on Hg methylation among strains in the genus Desulfovibrio is summarized, and we present methylation rates for several previously untested species. About 50% of Desulfovibrio strains tested to date have the ability to produce MeHg. Importantly, the ability to produce MeHg is constitutive and does not confer Hg resistance. A 16S rRNA-based alignment of the genus Desulfovibrio allows the very preliminary assessment that there may be some evolutionary basis for the ability to produce MeHg within this genus.

  6. Bacterial ice nuclei impact cloud lifetime and radiative properties and reduce atmospheric heat loss in the BRAMS simulation model

    NASA Astrophysics Data System (ADS)

    Costa, Tassio S.; Gonçalves, Fábio L. T.; Yamasoe, Marcia A.; Martins, Jorge A.; Morris, Cindy E.

    2014-08-01

    This study examines the effect of the bacterial species Pseudomonas syringae acting as ice nuclei (IN) on cloud properties to understand its impact on local radiative budget and heating rates. These bacteria may become active IN at temperatures as warm as -2 °C. Numerical simulations were developed using the Brazilian Regional Atmospheric Model System (BRAMS). To investigate the isolated effect of bacterial IN, four scenarios were created considering only homogeneous and bacterial ice nucleation, with 1, 10 and 100 IN per cubic meter of cloud volume and one with no bacteria. Moreover, two other scenarios were generated: the BRAMS default parameterization and its combination with bacterial IN. The model reproduced a strong convective cell over São Paulo on 3 March 2003. Results showed that bacterial IN may change cloud evolution as well as its microphysical properties, which in turn influence cloud radiative properties. For example, the reflected shortwave irradiance over an averaged domain in a scenario considering bacterial IN added to the BRAMS default parameterization was 14% lower than if bacteria were not considered. Heating rates can also be impacted, especially due to differences in cloud lifetime. Results suggest that the omission of bacterial IN in numerical models, including global cloud models, could neglect relevant ice nucleation processes that potentially influence cloud radiative properties.

  7. Environmental enrichment reduces neuronal intranuclear inclusion load but has no effect on messenger RNA expression in a mouse model of Huntington disease.

    PubMed

    Benn, Caroline L; Luthi-Carter, Ruth; Kuhn, Alexandre; Sadri-Vakili, Ghazaleh; Blankson, Kwabena L; Dalai, Sudeb C; Goldstein, Darlene R; Spires, Tara L; Pritchard, Joel; Olson, James M; van Dellen, Anton; Hannan, Anthony J; Cha, Jang-Ho J

    2010-08-01

    Huntington disease (HD) is a fatal neurodegenerative disease with no effective treatment. In the R6/1 mouse model of HD, environmental enrichment delays the neurologic phenotype onset and prevents cerebral volume loss by unknown molecular mechanisms. We examined the effects of environmental enrichment on well-characterized neuropathological parameters in a mouse model of HD. We found a trend toward preservation of downregulated neurotransmitter receptors in striatum of environmentally enriched mice and assessed possible enrichment-related modifications in gene expression using microarrays. We observed similar gene expression changes in R6/1 and R6/2 transgenic mice but found no specific changes in enrichment-related microarray expression profiles in either transgenic or wild-type mice. Furthermore, specific corrections in transprotein-induced transcriptional dysregulation in R6/1 mice were not detected by microarray profiling. However, gene-specific analyses suggested that long-term environmental enrichment may beneficially modulate gene expression dysregulation. Finally, environmental enrichment significantly decreased neuronal intranuclear inclusion load, despite unaffected transgene expression levels. Thus, the therapeutic effects of environmental enrichment likely contribute to decreasing aggregated polyglutamine protein levels without exerting strong effects on gene expression.

  8. A bacterial genome in transition - an exceptional enrichment of IS elements but lack of evidence for recent transposition in the symbiont Amoebophilus asiaticus

    PubMed Central

    2011-01-01

    Background Insertion sequence (IS) elements are important mediators of genome plasticity and are widespread among bacterial and archaeal genomes. The 1.88 Mbp genome of the obligate intracellular amoeba symbiont Amoebophilus asiaticus contains an unusually large number of transposase genes (n = 354; 23% of all genes). Results The transposase genes in the A. asiaticus genome can be assigned to 16 different IS elements termed ISCaa1 to ISCaa16, which are represented by 2 to 24 full-length copies, respectively. Despite this high IS element load, the A. asiaticus genome displays a GC skew pattern typical for most bacterial genomes, indicating that no major rearrangements have occurred recently. Additionally, the high sequence divergence of some IS elements, the high number of truncated IS element copies (n = 143), as well as the absence of direct repeats in most IS elements suggest that the IS elements of A. asiaticus are transpositionally inactive. Although we could show transcription of 13 IS elements, we did not find experimental evidence for transpositional activity, corroborating our results from sequence analyses. However, we detected contiguous transcripts between IS elements and their downstream genes at nine loci in the A. asiaticus genome, indicating that some IS elements influence the transcription of downstream genes, some of which might be important for host cell interaction. Conclusions Taken together, the IS elements in the A. asiaticus genome are currently in the process of degradation and largely represent reflections of the evolutionary past of A. asiaticus in which its genome was shaped by their activity. PMID:21943072

  9. Thromboxane A2 receptor antagonist SQ29548 reduces ischemic stroke-induced microglia/macrophages activation and enrichment, and ameliorates brain injury

    PubMed Central

    Yan, Aijuan; Zhang, Tingting; Yang, Xiao; Shao, Jiaxiang; Fu, Ningzhen; Shen, Fanxia; Fu, Yi; Xia, Weiliang

    2016-01-01

    Thromboxane A2 receptor (TXA2R) activation is thought to be involved in thrombosis/hemostasis and inflammation responses. We have previously shown that TXA2R antagonist SQ29548 attenuates BV2 microglia activation by suppression of ERK pathway, but its effect is not tested in vivo. The present study aims to explore the role of TXA2R on microglia/macrophages activation after ischemia/reperfusion brain injury in mice. Adult male ICR mice underwent 90-min transient middle cerebral artery occlusion (tMCAO). Immediately and 24 h after reperfusion, SQ29548 was administered twice to the ipsilateral ventricle (10 μl, 2.6 μmol/ml, per dose). Cerebral infarction volume, inflammatory cytokines release and microglia/macrophages activation were measured using the cresyl violet method, quantitative polymerase chain reaction (qPCR), and immunofluorescence double staining, respectively. Expression of TXA2R was significantly increased in the ipsilateral brain tissue after ischemia/reperfusion, which was also found to co-localize with activated microglia/macrophages in the infarct area. Administration of SQ29548 inhibited microglia/macrophages activation and enrichment, including both M1 and M2 phenotypes, and attenuated ischemia-induced IL-1ß, IL-6, and TNF-α up-regulation and iNOS release. TXA2R antagonist SQ29548 inhibited ischemia-induced inflammatory response and furthermore reduced microglia/macrophages activation and ischemic/reperfusion brain injury. PMID:27775054

  10. Tissue-resident Eomes(hi) T-bet(lo) CD56(bright) NK cells with reduced proinflammatory potential are enriched in the adult human liver.

    PubMed

    Harmon, Cathal; Robinson, Mark W; Fahey, Ronan; Whelan, Sarah; Houlihan, Diarmaid D; Geoghegan, Justin; O'Farrelly, Cliona

    2016-09-01

    The adult human liver is enriched with natural killer (NK) cells, accounting for 30-50% of hepatic lymphocytes, which include tissue-resident hepatic NK-cell subpopulations, distinct from peripheral blood NK cells. In murine liver, a subset of liver-resident hepatic NK cells have altered expression of the two highly related T-box transcription factors, T-bet and eomesodermin (Eomes). Here, we investigate the heterogeneity of T-bet and Eomes expression in NK cells from healthy adult human liver with a view to identifying human liver-resident populations. Hepatic NK cells were isolated from donor liver perfusates and biopsies obtained during orthotopic liver transplantation (N = 28). Hepatic CD56(bright) NK cells were Eomes(hi) T-bet(lo) , a phenotype virtually absent from peripheral blood. These NK cells express the chemokine receptor CXCR6 (chemokine (C-X-C motif) receptor 6), a marker of tissue residency, which is absent from hepatic CD56(dim) and blood NK cells. Compared to blood populations, these hepatic CD56(bright) NK cells have increased expression of activatory receptors (NKp44, NKp46, and NKG2D). They show reduced ability to produce IFN-γ but enhanced degranulation in response to challenge with target cells. This functionally distinct population of hepatic NK cells constitutes 20-30% of the total hepatic lymphocyte repertoire and represents a tissue-resident immune cell population adapted to the tolerogenic liver microenvironment.

  11. How does environmental enrichment reduce repetitive motor behaviors? Neuronal activation and dendritic morphology in the indirect basal ganglia pathway of a mouse model

    PubMed Central

    Bechard, Allison R.; Cacodcar, Nadia; King, Michael A.; Lewis, Mark H.

    2015-01-01

    Repetitive motor behaviors are observed in many neurodevelopmental and neurological disorders (e.g. autism spectrum disorders, Tourette syndrome, fronto-temporal dementia). Despite their clinical importance, the neurobiology underlying these highly stereotyped, apparently functionless behaviors is poorly understood. Identification of mechanisms that mediate the development of repetitive behaviors will aid in the discovery of new therapeutic targets and treatment development. Using a deer mouse model, we have shown that decreased indirect basal ganglia pathway activity is associated with high levels of repetitive behavior. Environmental enrichment (EE) markedly attenuates the development of such aberrant behaviors in mice, although mechanisms driving this effect are unknown. We hypothesized that EE would reduce repetitive motor behaviors by increasing indirect basal ganglia pathway function. We assessed neuronal activation and dendritic spine density in basal ganglia of adult deer mice reared in EE and standard housing. Significant increases in neuronal activation and dendritic spine densities were observed only in the subthalamic nucleus (STN) and globus pallidus (GP), and only for those mice that exhibited an EE-induced decrease in repetitive motor behavior. As the STN and GP lie within the indirect pathway, these data suggest that EE-induced attenuation of repetitive motor behaviors is associated with increased functional activation of the indirect basal ganglia pathway. These results are consistent with our other findings highlighting the importance of the indirect pathway in mediating repetitive motor behaviors. PMID:26620495

  12. Effect of nitrate and nitrite on sulfide production by two thermophilic, sulfate-reducing enrichments from an oil field in the North Sea.

    PubMed

    Kaster, Krista M; Grigoriyan, Alexander; Jenneman, Gary; Jennneman, Gary; Voordouw, Gerrit

    2007-05-01

    Thermophilic sulfate-reducing bacteria (tSRB) can be major contributors to the production of H(2)S (souring) in oil reservoirs. Two tSRB enrichments from a North Sea oil field, NS-tSRB1 and NS-tSRB2, were obtained at 58 degrees C with acetate-propionate-butyrate and with lactate as the electron donor, respectively. Analysis by rDNA sequencing indicated the presence of Thermodesulforhabdus norvegicus in NS-tSRB1 and of Archaeoglobus fulgidus in NS-tSRB2. Nitrate (10 mM) had no effect on H(2)S production by mid-log phase cultures of NS-tSRB1 and NS-tSRB2, whereas nitrite (0.25 mM or higher) inhibited sulfate reduction. NS-tSRB1 did not recover from inhibition, whereas sulfate reduction activity of NS-tSRB2 recovered after 500 h. Nitrite was also effective in souring inhibition and H(2)S removal in upflow bioreactors, whereas nitrate was similarly ineffective. Hence, nitrite may be preferable for souring prevention in some high-temperature oil fields because it reacts directly with sulfide and provides long-lasting inhibition of sulfate reduction.

  13. How does environmental enrichment reduce repetitive motor behaviors? Neuronal activation and dendritic morphology in the indirect basal ganglia pathway of a mouse model.

    PubMed

    Bechard, Allison R; Cacodcar, Nadia; King, Michael A; Lewis, Mark H

    2016-02-15

    Repetitive motor behaviors are observed in many neurodevelopmental and neurological disorders (e.g., autism spectrum disorders, Tourette syndrome, fronto-temporal dementia). Despite their clinical importance, the neurobiology underlying these highly stereotyped, apparently functionless behaviors is poorly understood. Identification of mechanisms that mediate the development of repetitive behaviors will aid in the discovery of new therapeutic targets and treatment development. Using a deer mouse model, we have shown that decreased indirect basal ganglia pathway activity is associated with high levels of repetitive behavior. Environmental enrichment (EE) markedly attenuates the development of such aberrant behaviors in mice, although mechanisms driving this effect are unknown. We hypothesized that EE would reduce repetitive motor behaviors by increasing indirect basal ganglia pathway function. We assessed neuronal activation and dendritic spine density in basal ganglia of adult deer mice reared in EE and standard housing. Significant increases in neuronal activation and dendritic spine densities were observed only in the subthalamic nucleus (STN) and globus pallidus (GP), and only for those mice that exhibited an EE-induced decrease in repetitive motor behavior. As the STN and GP lie within the indirect pathway, these data suggest that EE-induced attenuation of repetitive motor behaviors is associated with increased functional activation of the indirect basal ganglia pathway. These results are consistent with our other findings highlighting the importance of the indirect pathway in mediating repetitive motor behaviors.

  14. SURFACE FINISHES ON STAINLESS STEEL REDUCE BACTERIAL ATTACHMENT AND EARLY BIOFILM FORMATION: SCANNING ELECTRON AND ATOMIC FORCE MICROSCOPY STUDY

    EPA Science Inventory

    Three common finishing treatments of stainless steel that are used for equipment during poultry processing were tested for resistance to bacterial contamination. Methods were developed to measure attached bacteria and to identify factors that make surface finishes susceptible or ...

  15. COMPARISON OF SCANNING ELECTRON AND ATOMIC FORCE MICROSCOPY OF SURFACE FINISHES ON STAINLESS STEEL THAT REDUCE BACTERIAL ATTACHMENT

    EPA Science Inventory

    Bacteria adhere to food products and processing surfaces that can cross-contaminate other products and work surfaces (Arnold, 1998). Using materials for food processing surfaces that are resistant to bacterial contamination could enhance food safety. Stainless steel, although sus...

  16. COMPARISON OF SCANNING ELECTRON AND ATOMIC FORCE MICROSCOPY OF SURFACE FINISHES ON STAINLESS STEEL THAT REDUCE BACTERIAL ATTACHMENT

    EPA Science Inventory

    Bacteria adhere to food products and processing surfaces that can cross-contaminate other products and work surfaces (Arnold, 1998). Using materials for food processing surfaces that are resistant to bacterial contamination could enhance food safety. Stainless steel, although sus...

  17. SURFACE FINISHES ON STAINLESS STEEL REDUCE BACTERIAL ATTACHMENT AND EARLY BIOFILM FORMATION: SCANNING ELECTRON AND ATOMIC FORCE MICROSCOPY STUDY

    EPA Science Inventory

    Three common finishing treatments of stainless steel that are used for equipment during poultry processing were tested for resistance to bacterial contamination. Methods were developed to measure attached bacteria and to identify factors that make surface finishes susceptible or ...

  18. Short term Candida albicans colonization reduces Pseudomonas aeruginosa-related lung injury and bacterial burden in a murine model

    PubMed Central

    2011-01-01

    Introduction Pseudomonas aeruginosa is a frequent cause of ventilator-acquired pneumonia (VAP). Candida tracheobronchial colonization is associated with higher rates of VAP related to P. aeruginosa. This study was designed to investigate whether prior short term Candida albicans airway colonization modulates the pathogenicity of P. aeruginosa in a murine model of pneumonia and to evaluate the effect of fungicidal drug caspofungin. Methods BALB/c mice received a single or a combined intratracheal administration of C. albicans (1 × 105 CFU/mouse) and P. aeruginosa (1 × 107 CFU/mouse) at time 0 (T0) upon C. albicans colonization, and Day 2. To evaluate the effect of antifungal therapy, mice received caspofungin intraperitoneally daily, either from T0 or from Day 1 post-colonization. After sacrifice at Day 4, lungs were analyzed for histological scoring, measurement of endothelial injury, and quantification of live P. aeruginosa and C. albicans. Blood samples were cultured for dissemination. Results A significant decrease in lung endothelial permeability, the amount of P. aeruginosa, and bronchiole inflammation was observed in case of prior C. albicans colonization. Mortality rate and bacterial dissemination were unchanged by prior C. albicans colonization. Caspofungin treatment from T0 (not from Day 1) increased their levels of endothelial permeability and lung P. aeruginosa load similarly to mice receiving P. aeruginosa alone. Conclusions P. aeruginosa-induced lung injury is reduced when preceded by short term C. albicans airway colonization. Antifungal drug caspofungin reverses that effect when used from T0 and not from Day 1. PMID:21689424

  19. Improving efficiency and reducing costs: Design of an adaptive, seamless, and enriched pragmatic efficacy trial of an online asthma management program.

    PubMed

    Lu, Mei; Ownby, Dennis R; Zoratti, Edward; Roblin, Douglas; Johnson, Dayna; Johnson, Christine Cole; Joseph, Christine L M

    2014-05-01

    Clinical trials are critical for medical decision-making, however, under the current paradigm, clinical trials are fraught with problems including low enrollment and high cost. Promising alternatives to increase trial efficiency and reduce costs include the use of (1) electronic initiatives that permit electronic remote data capture (EDC) for direct data collection at a site (2), electronic medical records (EMR) for patient identification and data collection, and (3) adaptive, enrichment designs with pragmatic approaches. We describe the design of a seamless, multi-site randomized Phase II/III trial to evaluate an asthma management intervention in urban adolescents with asthma. Patients are randomized, asked to access four online sessions of the intervention or control asthma management program, and are then followed for one year. The primary efficacy endpoint is self-reported asthma control as measured by the Asthma Control Test (ACT). Comparative effectiveness parametric approaches are utilized to conduct the trial in a real world setting with reduced costs. Escalated electronic initiatives are implemented for patient identification, assent, enrollment and tracking. Patient enrollment takes place during primary care visits. A centralized database with EDC is used for CRF data collection with integration of EMR data. This Phase II/III trial plans to have a total sample size of 500 patients with an interim look at the completion of Phase II (n=250), The interim analyses include an assessment of the intervention effect, marker(s) identification and the feasibility study of EMR data as the trial CRF data collection. Patient enrollment has begun and is ongoing.

  20. Free-air CO2 enrichment (FACE) reduces the inhibitory effect of soil nitrate on N2 fixation of Pisum sativum

    PubMed Central

    Butterly, Clayton R.; Armstrong, Roger; Chen, Deli; Tang, Caixian

    2016-01-01

    Background and Aims Additional carbohydrate supply resulting from enhanced photosynthesis under predicted future elevated CO2 is likely to increase symbiotic nitrogen (N) fixation in legumes. This study examined the interactive effects of atmospheric CO2 and nitrate (NO3–) concentration on the growth, nodulation and N fixation of field pea (Pisum sativum) in a semi-arid cropping system. Methods Field pea was grown for 15 weeks in a Vertosol containing 5, 25, 50 or 90 mg NO3–-N kg–1 under either ambient CO2 (aCO2; 390 ppm) or elevated CO2 (eCO2; 550 ppm) using free-air CO2 enrichment (SoilFACE). Key Results Under aCO2, field pea biomass was significantly lower at 5 mg NO3–-N kg–1 than at 90 mg NO3–-N kg–1 soil. However, increasing the soil N level significantly reduced nodulation of lateral roots but not the primary root, and nodules were significantly smaller, with 85 % less nodule mass in the 90 NO3–-N kg–1 than in the 5 mg NO3–-N kg–1 treatment, highlighting the inhibitory effects of NO3–. Field pea grown under eCO2 had greater biomass (approx. 30 %) than those grown under aCO2, and was not affected by N level. Overall, the inhibitory effects of NO3– on nodulation and nodule mass appeared to be reduced under eCO2 compared with aCO2, although the effects of CO2 on root growth were not significant. Conclusions Elevated CO2 alleviated the inhibitory effect of soil NO3– on nodulation and N2 fixation and is likely to lead to greater total N content of field pea growing under future elevated CO2 environments. PMID:26346721

  1. A reduced fraction of plant N derived from atmospheric N (%Ndfa) and reduced rhizobial nifH gene numbers indicate a lower capacity for nitrogen fixation in nodules of white clover exposed to long-term CO2 enrichment

    NASA Astrophysics Data System (ADS)

    Watanabe, T.; Bowatte, S.; Newton, P. C. D.

    2013-06-01

    Using the δ15N natural abundance method, we found that the fraction of nitrogen derived from atmospheric N (%Ndfa) in field grown white clover (Trifolium repens L.) plants was significantly lower (72.0% vs. 89.5%, p = 0.047 in a grassland exposed to elevated CO2 for 13 yr using Free Air Carbon Dioxide Enrichment (FACE). Twelve months later we conducted an experiment to investigate the reasons behind the reduced N fixation. We took cuttings from white clover plants growing in the FACE and established individual plants in a glasshouse using soil from the appropriate ambient or elevated CO2 treatments. The established plants were then transplanted back into their "rings of origin" and sampled over a 6 week period. We used molecular ecological analyses targeting nifH genes and transcripts of rhizobia in symbiosis with white clover (Trifolium repens L.) to understand the potential mechanisms. Shoot biomass was significantly lower in eCO2 but there was no difference in nodule number or mass per plant. The numbers of nifH genes and gene transcripts per nodule were significantly reduced under eCO2 but the ratio of gene to transcript number and the strains of rhizobia present were the same in both treatments. We conclude that the capacity for biological nitrogen fixation was reduced by eCO2 in white clover and was related to the reduced rhizobia numbers in nodules. We discuss the finding of reduced gene number in relation to factors controlling bacteroid DNA amount which may imply an influence of nitrogen as well as phosphorus.

  2. A reduced fraction of plant N derived from atmospheric N (%Ndfa) and reduced rhizobial nifH gene numbers indicate a lower capacity for nitrogen fixation in nodules of white clover exposed to long-term CO2 enrichment

    NASA Astrophysics Data System (ADS)

    Watanabe, T.; Bowatte, S.; Newton, P. C. D.

    2013-12-01

    Using the δ15N natural abundance method, we found that the fraction of nitrogen derived from atmospheric N (%Ndfa) in field-grown white clover (Trifolium repens L.) plants was significantly lower (72.0% vs. 89.8%, p = 0.047 in a grassland exposed to elevated CO2 for 13 yr using free air carbon dioxide enrichment (FACE). Twelve months later we conducted an experiment to investigate the reasons behind the reduced N fixation. We took cuttings from white clover plants growing in the FACE and established individual plants in a glasshouse using soil from the appropriate ambient or elevated CO2 treatments. The established plants were then transplanted back into their "rings of origin" and sampled over a 6-week period. We used molecular ecological analyses targeting nifH genes and transcripts of rhizobia in symbiosis with white clover (Trifolium repens L.) to understand the potential mechanisms. Shoot biomass was significantly lower in eCO2, but there was no difference in nodule number or mass per plant. The numbers of nifH genes and gene transcripts per nodule were significantly reduced under eCO2, but the ratio of gene to transcript number and the strains of rhizobia present were the same in both treatments. We conclude that the capacity for biological nitrogen fixation was reduced by eCO2 in white clover and was related to the reduced rhizobia numbers in nodules. We discuss the finding of reduced gene number in relation to factors controlling bacteroid DNA amount, which may imply an influence of nitrogen as well as phosphorus.

  3. ß-Phenylethylamine as a novel nutrient treatment to reduce bacterial contamination due to Escherichia coli O157:H7 on beef meat.

    PubMed

    Lynnes, Ty; Horne, S M; Prüß, B M

    2014-01-01

    Bacterial infection by Escherichia coli O157:H7 through the consumption of beef meat or meat products is an ongoing problem, in part because bacteria develop resistances towards chemicals aimed at killing them. In an approach that uses bacterial nutrients to manipulate bacteria into behaviors or cellular phenotypes less harmful to humans, we screened a library of 95 carbon and 95 nitrogen sources for their effect on E. coli growth, cell division, and biofilm formation. In the initial screening experiment using the Phenotype MicroArray(TM) technology from BioLog (Hayward, CA), we narrowed the 190 starting nutrients down to eight which were consecutively tested as supplements in liquid beef broth medium. Acetoacetic acid (AAA) and ß-phenylethylamine (PEA) performed best in this experiment. On beef meat pieces, PEA reduced the bacterial cell count by 90% after incubation of the PEA treated and E. coli contaminated meat pieces at 10°C for one week. © 2013.

  4. Selected Lactic Acid-Producing Bacterial Isolates with the Capacity to Reduce Salmonella Translocation and Virulence Gene Expression in Chickens

    PubMed Central

    Yang, Xiaojian; Brisbin, Jennifer; Yu, Hai; Wang, Qi; Yin, Fugui; Zhang, Yonggang; Sabour, Parviz; Sharif, Shayan; Gong, Joshua

    2014-01-01

    Background Probiotics have been used to control Salmonella colonization/infection in chickens. Yet the mechanisms of probiotic effects are not fully understood. This study has characterized our previously-selected lactic acid-producing bacterial (LAB) isolates for controlling Salmonella infection in chickens, particularly the mechanism underlying the control. Methodology/Principal Findings In vitro studies were conducted to characterize 14 LAB isolates for their tolerance to low pH (2.0) and high bile salt (0.3–1.5%) and susceptibility to antibiotics. Three chicken infection trials were subsequently carried out to evaluate four of the isolates for reducing the burden of Salmonella enterica serovar Typhimurium in the broiler cecum. Chicks were gavaged with LAB cultures (106–7 CFU/chick) or phosphate-buffered saline (PBS) at 1 day of age followed by Salmonella challenge (104 CFU/chick) next day. Samples of cecal digesta, spleen, and liver were examined for Salmonella counts on days 1, 3, or 4 post-challenge. Salmonella in the cecum from Trial 3 was also assessed for the expression of ten virulence genes located in its pathogenicity island-1 (SPI-1). These genes play a role in Salmonella intestinal invasion. Tested LAB isolates (individuals or mixed cultures) were unable to lower Salmonella burden in the chicken cecum, but able to attenuate Salmonella infection in the spleen and liver. The LAB treatments also reduced almost all SPI-1 virulence gene expression (9 out of 10) in the chicken cecum, particularly at the low dose. In vitro treatment with the extracellular culture fluid from a LAB culture also down-regulated most SPI-1 virulence gene expression. Conclusions/Significance The possible correlation between attenuation of Salmonella infection in the chicken spleen and liver and reduction of Salmonella SPI-1 virulence gene expression in the chicken cecum by LAB isolates is a new observation. Suppression of Salmonella virulence gene expression in vivo can be one

  5. Micro-patterned surfaces reduce bacterial colonization and biofilm formation in vitro: Potential for enhancing endotracheal tube designs

    PubMed Central

    2014-01-01

    Background Ventilator-associated pneumonia (VAP) is a leading hospital acquired infection in intensive care units despite improved patient care practices and advancements in endotracheal tube (ETT) designs. The ETT provides a conduit for bacterial access to the lower respiratory tract and a substratum for biofilm formation, both of which lead to VAP. A novel microscopic ordered surface topography, the Sharklet micro-pattern, has been shown to decrease surface attachment of numerous microorganisms, and may provide an alternative strategy for VAP prevention if included on the surface of an ETT. To evaluate the feasibility of this micro-pattern for this application, the microbial range of performance was investigated in addition to biofilm studies with and without a mucin-rich medium to simulate the tracheal environment in vitro. Methods The top five pathogens associated with ETT-related pneumonia, Methicillin-Resistant Staphylococcus aureus (MRSA), Pseudomonas aeruginosa, Klebsiella pneumonia, Acinetobacter baumannii, and Escherichia coli, were evaluated for attachment to micro-patterned and un-patterned silicone surfaces in a short-term colonization assay. Two key pathogens, MRSA and Pseudomonas aeruginosa, were evaluated for biofilm formation in a nutrient rich broth for four days and minimal media for 24 hours, respectively, on each surface type. P. aeruginosa was further evaluated for biofilm formation on each surface type in a mucin-modified medium mimicking tracheal mucosal secretions. Results are reported as percent reductions and significance is based on t-tests and ANOVA models of log reductions. All experiments were replicated at least three times. Results Micro-patterned surfaces demonstrated reductions in microbial colonization for a broad range of species, with up to 99.9% (p < 0.05) reduction compared to un-patterned controls. Biofilm formation was also reduced, with 67% (p = 0.12) and 52% (p = 0.05) reductions in MRSA and P. aeruginosa

  6. Micro-patterned surfaces reduce bacterial colonization and biofilm formation in vitro: Potential for enhancing endotracheal tube designs.

    PubMed

    May, Rhea M; Hoffman, Matthew G; Sogo, Melinda J; Parker, Albert E; O'Toole, George A; Brennan, Anthony B; Reddy, Shravanthi T

    2014-01-01

    Ventilator-associated pneumonia (VAP) is a leading hospital acquired infection in intensive care units despite improved patient care practices and advancements in endotracheal tube (ETT) designs. The ETT provides a conduit for bacterial access to the lower respiratory tract and a substratum for biofilm formation, both of which lead to VAP. A novel microscopic ordered surface topography, the Sharklet micro-pattern, has been shown to decrease surface attachment of numerous microorganisms, and may provide an alternative strategy for VAP prevention if included on the surface of an ETT. To evaluate the feasibility of this micro-pattern for this application, the microbial range of performance was investigated in addition to biofilm studies with and without a mucin-rich medium to simulate the tracheal environment in vitro. The top five pathogens associated with ETT-related pneumonia, Methicillin-Resistant Staphylococcus aureus (MRSA), Pseudomonas aeruginosa, Klebsiella pneumonia, Acinetobacter baumannii, and Escherichia coli, were evaluated for attachment to micro-patterned and un-patterned silicone surfaces in a short-term colonization assay. Two key pathogens, MRSA and Pseudomonas aeruginosa, were evaluated for biofilm formation in a nutrient rich broth for four days and minimal media for 24 hours, respectively, on each surface type. P. aeruginosa was further evaluated for biofilm formation on each surface type in a mucin-modified medium mimicking tracheal mucosal secretions. Results are reported as percent reductions and significance is based on t-tests and ANOVA models of log reductions. All experiments were replicated at least three times. Micro-patterned surfaces demonstrated reductions in microbial colonization for a broad range of species, with up to 99.9% (p < 0.05) reduction compared to un-patterned controls. Biofilm formation was also reduced, with 67% (p = 0.12) and 52% (p = 0.05) reductions in MRSA and P. aeruginosa biofilm formation

  7. Hormonal Contraception Is Associated with a Reduced Risk of Bacterial Vaginosis: A Systematic Review and Meta-Analysis

    PubMed Central

    Vodstrcil, Lenka A.; Hocking, Jane S.; Law, Matthew; Walker, Sandra; Tabrizi, Sepehr N.; Fairley, Christopher K.; Bradshaw, Catriona S.

    2013-01-01

    Objective To examine the association between hormonal contraception (HC) and bacterial vaginosis (BV) by systematic review and meta-analysis. Methods Medline, Web of Science and Embase databases were searched to 24/1/13 and duplicate references removed. Inclusion criteria 1) >20 BV cases; 2) accepted BV diagnostic method; 3) measure of HC-use either as combined oestrogen-progesterone HC (combined), progesterone-only contraception (POC) or unspecified HC (u-HC); 4) ≥10% of women using HC; 5) analysis of the association between BV and HC-use presented; 6) appropriate control group. Data extracted included: type of HC, BV diagnostic method and outcome (prevalent, incident, recurrent), and geographical and clinic-setting. Meta-analyses were conducted to calculate pooled effect sizes (ES), stratified by HC-type and BV outcome. This systematic review is registered with PROSPERO (CRD42013003699). Results Of 1713 unique references identified, 502 full-text articles were assessed for eligibility and 55 studies met inclusion criteria. Hormonal contraceptive use was associated with a significant reduction in the odds of prevalent BV (pooled effect size by random-effects [reES] = 0.68, 95%CI0.63–0.73), and in the relative risk (RR) of incident (reES = 0.82, 95%CI:0.72–0.92), and recurrent (reES = 0.69, 95%CI:0.59–0.91) BV. When stratified by HC-type, combined-HC and POC were both associated with decreased prevalence of BV and risk of incident BV. In the pooled analysis of the effect of HC-use on the composite outcome of prevalent/incident/recurrent BV, HC-use was associated with a reduced risk of any BV (reES = 0.78, 95%CI:0.74–0.82). Conclusion HC-use was associated with a significantly reduced risk of BV. This negative association was robust and present regardless of HC-type and evident across all three BV outcome measures. When stratified by HC-type, combined-HC and POC were both individually associated with a reduction in the prevalence and

  8. Compare the effcacy of two commercially available mouthrinses in reducing viable bacterial count in dental aerosol produced during ultrasonic scaling when used as a preprocedural rinse.

    PubMed

    Shetty, Shamila K; Sharath, Karanth; Shenoy, Santhosh; Sreekumar, Chandini; Shetty, Rashmi N; Biju, Thomas

    2013-09-01

    To evaluate and compare the effcacy of preprocedural mouthrinses (chlorhexidine digluconate and tea tree oil) in reducing microbial content of aerosol product during ultrasonic scaling procedures by viable bacterial count. It was a randomized single blind, placebo-controlled parallel group study. Sixty subjects were randomly assigned to rinse 10 ml of any one of the mouthrinses (chlorhexidine digluconate or tea tree oil or distilled water). Ultrasonic scaling was done for a period of 10 minutes in presence of trypticase soy agar plates placed at standardized distance. Plates were then sent for microbiological evaluation for the aerosol produced. This study showed that all the antiseptic mouthwashes signifcantly reduced the bacterial colony forming units (CFUs) in aerosol samples. Chlorhexidine rinses were found to be superior to tea tree when used preprocedurally in reducing aerolized bacteria. This study advocates preprocedural dural rinsing with an effective antimicrobial mouthrinse during any dental treatment which generates aerosols, reduces the risk of cross-contamination with infectious agents in the dental operatory. The aerolization of oral microbes occurring during dental procedures can potentially result in cross-contamination in the dental operatory and transmission of infectious agents to both dental professionals and patient. It is reasonable to assume therefore, that any stratagem for reducing the viable bacterial content of these aerosols could lower the risk of cross-contamination.

  9. Fermented milk containing Lactobacillus paracasei subsp. paracasei CNCM I-1518 reduces bacterial translocation in rats treated with carbon tetrachloride

    PubMed Central

    Sánchez, Elisabet; Nieto, Juan C.; Vidal, Silvia; Santiago, Alba; Martinez, Xavier; Sancho, Francesc J.; Sancho-Bru, Pau; Mirelis, Beatriz; Corominola, Helena; Juárez, Candido; Manichanh, Chaysavanh; Guarner, Carlos; Soriano, German

    2017-01-01

    Probiotics can prevent pathological bacterial translocation by modulating intestinal microbiota and improving the gut barrier. The aim was to evaluate the effect of a fermented milk containing Lactobacillus paracasei subsp. paracasei CNCM I-1518 on bacterial translocation in rats with carbon tetrachloride (CCl4)-induced cirrhosis. Sprague-Dawley rats treated with CCl4 were randomized into a probiotic group that received fermented milk containing Lactobacillus paracasei subsp. paracasei CNCM I-1518 in drinking water or a water group that received water only. Laparotomy was performed one week after ascites development. We evaluated bacterial translocation, intestinal microbiota, the intestinal barrier and cytokines in mesenteric lymph nodes and serum. Bacterial