WorldWideScience

Sample records for bacterial feeding induces

  1. Enteral feeding induces diet-dependent mucosal dysfunction, bacterial proliferation, and necrotizing enterocolitis in preterm pigs on parenteral nutrition

    DEFF Research Database (Denmark)

    Bjørnvad, Charlotte R.; Thymann, Thomas; Deutz, Nicolaas E.;

    2008-01-01

    Preterm neonates have an immature gut and metabolism and may benefit from total parenteral nutrition (TPN) before enteral food is introduced. Conversely,delayed enteral feeding may inhibit gut maturation and sensitize to necrotizing enterocolitis (NEC). Intestinal mass and NEC lesions were first...... recorded in preterm pigs fed enterally (porcine colostrum, bovine colostrum, or formula for 20–40 h), with or without a preceding 2- to 3-day TPN period (n 435). Mucosal mass increased during TPN and further after enteral feeding to reach an intestinal mass similar to that in enterally fed pigs without TPN...... (60–80% relative to birth). NEC developed only after enteral feeding but more often after a preceding TPN period for both sow’s colostrum (26 vs. 5%) and formula (62 vs. 39%, both P 0.001, n 43–170). Further studies in 3-day-old TPN pigs fed enterally showed that formula feeding decreased villus...

  2. Enteral feeding induces diet-dependent mucosal dysfunction, bacterial overgrowth and necrotizing enterocolitis in preterm parenterally-fed pigs

    Science.gov (United States)

    Preterm neonates have an immature gut and metabolism and may benefit from a period of total parenteral nutrition (TPN) before enteral food introduction. Conversely, delayed enteral feeding may inhibit gut maturation and sensitize to necrotizing enterocolitis (NEC). Intestinal mass and NEC lesions we...

  3. Enteral feeding induces diet-dependent mucosal dysfunction, bacterial proliferation, and necrotizing enterocolitis in preterm pigs on parenteral nutrition.

    Science.gov (United States)

    Bjornvad, Charlotte R; Thymann, Thomas; Deutz, Nicolaas E; Burrin, Douglas G; Jensen, Søren K; Jensen, Bent B; Mølbak, Lars; Boye, Mette; Larsson, Lars-Inge; Schmidt, Mette; Michaelsen, Kim F; Sangild, Per T

    2008-11-01

    Preterm neonates have an immature gut and metabolism and may benefit from total parenteral nutrition (TPN) before enteral food is introduced. Conversely, delayed enteral feeding may inhibit gut maturation and sensitize to necrotizing enterocolitis (NEC). Intestinal mass and NEC lesions were first recorded in preterm pigs fed enterally (porcine colostrum, bovine colostrum, or formula for 20-40 h), with or without a preceding 2- to 3-day TPN period (n = 435). Mucosal mass increased during TPN and further after enteral feeding to reach an intestinal mass similar to that in enterally fed pigs without TPN (+60-80% relative to birth). NEC developed only after enteral feeding but more often after a preceding TPN period for both sow's colostrum (26 vs. 5%) and formula (62 vs. 39%, both P colostrum (bovine or porcine, P gut permeability increased, relative to colostrum (all P gut dysfunction, microbial imbalance, and NEC in preterm pigs, especially in pigs fed formula after TPN. Conversely, colostrum milk diets improve gut maturation and NEC resistance in preterm pigs subjected to a few days of TPN after birth. PMID:18818317

  4. Bacterial feeding induces changes in immune-related gene expression and has trans-generational impacts in the cabbage looper (Trichoplusia ni

    Directory of Open Access Journals (Sweden)

    Vogel Heiko

    2009-05-01

    Full Text Available Abstract Background Poly- and oligophagous insects are able to feed on various host plants with a wide range of defense strategies. However, diverse food plants are also inhabited by microbiota differing in quality and quantity, posing a potential challenge for immune system mediated homeostasis in the herbivore. Recent studies highlight the complex interactions between environmentally encountered microorganisms and herbivorous insects, pointing to a potential adaptational alteration of the insects' physiology. We performed a differential gene expression analysis in whole larvae and eggs laid by parents grown on different diets to identify potential novel genes related to elevated microbial content in the caterpillars' food. Results We used GeneFishing, a novel differential display method, to study the effects of dietary bacteria on the general gene expression in different life stages and tissues of the cabbage looper (Trichoplusia ni. We were able to visualize several hundred transcripts on agarose gels, one fifth of which were differentially expressed between treatments. The largest number of differentially expressed genes was found in defense-related processes (13 and in recognition and metabolism (16. 21 genes were picked out and further tested for differential gene expression by an independent method (qRT-PCR in various tissues of larvae grown on bacterial and bacteria-free diet, and also in adults. We detected a number of genes indicative of an altered physiological status of the insect, depending on the diet, developmental stage and tissue. Conclusion Changes in immune status are accompanied by specific changes in the transcript levels of genes connected to metabolism and homeostasis of the organism. Our findings show that larval feeding on bacteria-rich diet leads to substantial gene expression changes, potentially resulting in a reorganization of the insects' metabolism to maintain organismal homeostasis, not only in the larval but also

  5. Characterisation of the gastrointestinal bacterial community in pigs fed fermented liquid feed and dry feed

    DEFF Research Database (Denmark)

    Højberg, Ole; Knudsen, B.; Canibe, N.;

    2001-01-01

    Feeding pigs with fermented liquid feed (FLF) has been shown to reduce the number of enteropathogens such as Salmonella and Brachyospira hyodysenteriae as well as coliform bacteria in general in the gastrointestinal tract (GIT). Also the commensal bacterial populations have been shown to respond to...

  6. Antimicrobial effect against different bacterial strains and bacterial adaptation to essential oils used as feed additives.

    Science.gov (United States)

    Melo, Antonio Diego Brandão; Amaral, Amanda Figueiredo; Schaefer, Gustavo; Luciano, Fernando Bittencourt; de Andrade, Carla; Costa, Leandro Batista; Rostagno, Marcos Horácio

    2015-10-01

    The aim of this study was to evaluate the antimicrobial activity and determine the minimum bactericidal concentration (MBC) of the essential oils derived from Origanum vulgare (oregano), Melaleuca alternifolia (tea tree), Cinnamomum cassia (cassia), and Thymus vulgaris (white thyme) against Salmonella Typhimurium, Salmonella Enteritidis, Escherichia coli, Staphylococcus aureus and Enterococcus faecalis. The study also investigated the ability of these different bacterial strains to develop adaptation after repetitive exposure to sub-lethal concentrations of these essential oils. The MBC of the essential oils studied was determined by disc diffusion and broth dilution methods. All essential oils showed antimicrobial effect against all bacterial strains. In general, the development of adaptation varied according to the bacterial strain and the essential oil (tea tree > white thyme > oregano). Therefore, it is important to use essential oils at efficient bactericidal doses in animal feed, food, and sanitizers, since bacteria can rapidly develop adaptation when exposed to sub-lethal concentrations of these oils. PMID:26424908

  7. Assessment of the suitability of food colouring materials as indicators of bacterial contamination of enteral feeds.

    Science.gov (United States)

    Anderton, A

    1988-04-01

    The suitability of using food colouring materials in enteral feeds as indicators of bacterial contamination was examined. Experiments using Triosorbon, Clinifeed ISO or Vivonex Standard plus amaranth, carmoisine, ponceau 4R, sunset yellow FCF, tartrazine or erythrosine demonstrated that although the change in appearance of coloured feed could be linked with the presence of high numbers of bacteria in the feed, the converse was not always true. PMID:2899111

  8. High-grain feeding causes strong shifts in ruminal epithelial bacterial community and expression of Toll-like receptor genes in goats

    OpenAIRE

    Liu, Jun-Hua; Bian, Gao-rui; Zhu, Wei-yun; Mao, Sheng-yong

    2015-01-01

    High-grain (HG) feeding used in intensive goat production can affect the physiology of the rumen wall, but the changes induced in the epimural bacterial community and host Toll-like receptors (TLRs) are not well understood. In this study, 10 male goats were randomly allocated to two groups and fed either a hay diet (0% grain; n = 5) or an HG diet (65% grain; n = 5). The changes in the ruminal epithelial bacterial community and expression of TLRs during long-term (7 weeks) HG feeding were dete...

  9. Daily changes in bacterial-feeding nematode populations oscillate with similar periods as bacterial populations after a nutrient impulse in soil

    NARCIS (Netherlands)

    Zelenev, V.V.; Berkelmans, R.A.; Bruggen, van A.H.C.; Bongers, A.M.T.; Semenov, A.M.

    2004-01-01

    Previously, we showed that bacterial populations oscillated in a regular manner in response to a nutrient impulse in soil. For this paper we investigated if the wave-like fluctuations in bacterial populations could be explained by their interactions with populations of bacterial-feeding nematodes (B

  10. Bacterial microflora of poultry feed and its control by gamma irradiation

    International Nuclear Information System (INIS)

    The common bacteria isolated from the poultry feed samples were classified in the families of Pseudomonadaceae, Micrococcacae, Bacililaceae and Enterobacteriaceae. These species of bacteria were identified as 10 species of Gram-negative and 13 species of Gram-positive. We found that radiation dose required to inhibit completely the natural bacterial flora in tested samples of poultry feed was 20 KGY. The most radioresistant bacterial isolates which resisted a sublethal dose of 15 KGY were identified as bacillus cereus, Bacillus polymxa and Bacillus megaterium. The dose response curves of B, cereus and B, polymxa started by shoulder portion followed by an exponential death, whereas, B, megaterium exhibited straight line relationship directly. The D10-value of B. megaterium spores (3.30 KGY) was about 1.5 and 1.7 folds as the D10 value B. polymxa and B, cereus, respectively. The present work indicated also that the exposure of poultry feed to irradiation dose 10 KGY (1 Mrad) reduced greatly number of bacteria destroyed all spoilage and pathogenic bacteria especially Salmonella, and finally increased the shelf-life during storage periods. Higher radiation dose 15 KGY, failed to show any better reduction of viable bacterial counts. Part of this work presented in (FAO/IAEA) international symposium for food irradiation processing, Washington, D.C., U.S.A. (4-8 March, 1985)

  11. Bacterial Gibberellins Induce Systemic Resistance of Plants

    Directory of Open Access Journals (Sweden)

    I. N. FEKLISTOVA

    2014-06-01

    Full Text Available It is generally agreed today that some rhizosphere bacteria can ensure induced systemic resistance to pathogens. In this paper we tested the ability of gibberellins produced by rhizosphere non-pathogenic bacteria Pseudomonas aurantiaca to induce systemic resistance to alternariosis agent – Alternaria brassicicola – in oilseed rape plants.Oilseed rape (Brássica nápus is one of the most promising oil-bearing croppers. It allows improving the supply of population with vegetable oil, animal and poultry industries with high quality vegetable protein. It is used for biofuel production as well.Gibberellin preparation was isolated from liquid culture of strain Pseudomonas aurantiaca grown in 250 mL of M9 medium (48 h, 28 °C under darkroom conditions. Gibberellins were extracted according procedure described by Tien et al. (1979. Gibberellins concentration in the medium was determined by fluorometric method.Elicitor activity of bacterial metabolites – gibberellins – was analyzed in model system of artificial inoculation of oilseed rape germs with phytopathogenic fungi Alternaria brassicicola. The elicitor action efficiency was evaluated on the 15th day of oilseed rape cultivation based on the percentage of leaf surface covered by necrotic lesions.Gibberellins were shown to induce systemic resistance resulted in decreasing of oil seed plants   vulnerability by 52.7%.It is known that under the unfavorable conditions plants synthesis the reactive oxygen intermediates   which activate destructive processes. One of the first organism reactions to stress action is the change of the lipid peroxidation level. It was shown that treatment of the soil with gibberellins resulted in decreasing of the lipid peroxidation level twofold.Gibberellins were shown to have a similar effect on permeability of cell membranes for free nucleotides. The permeability of cell membranes in leaves decreased 2.8-fold at room temperature. We suggest that gibberellins

  12. Metabolic Coevolution in the Bacterial Symbiosis of Whiteflies and Related Plant Sap-Feeding Insects.

    Science.gov (United States)

    Luan, Jun-Bo; Chen, Wenbo; Hasegawa, Daniel K; Simmons, Alvin M; Wintermantel, William M; Ling, Kai-Shu; Fei, Zhangjun; Liu, Shu-Sheng; Douglas, Angela E

    2015-09-01

    Genomic decay is a common feature of intracellular bacteria that have entered into symbiosis with plant sap-feeding insects. This study of the whitefly Bemisia tabaci and two bacteria (Portiera aleyrodidarum and Hamiltonella defensa) cohoused in each host cell investigated whether the decay of Portiera metabolism genes is complemented by host and Hamiltonella genes, and compared the metabolic traits of the whitefly symbiosis with other sap-feeding insects (aphids, psyllids, and mealybugs). Parallel genomic and transcriptomic analysis revealed that the host genome contributes multiple metabolic reactions that complement or duplicate Portiera function, and that Hamiltonella may contribute multiple cofactors and one essential amino acid, lysine. Homologs of the Bemisia metabolism genes of insect origin have also been implicated in essential amino acid synthesis in other sap-feeding insect hosts, indicative of parallel coevolution of shared metabolic pathways across multiple symbioses. Further metabolism genes coded in the Bemisia genome are of bacterial origin, but phylogenetically distinct from Portiera, Hamiltonella and horizontally transferred genes identified in other sap-feeding insects. Overall, 75% of the metabolism genes of bacterial origin are functionally unique to one symbiosis, indicating that the evolutionary history of metabolic integration in these symbioses is strongly contingent on the pattern of horizontally acquired genes. Our analysis, further, shows that bacteria with genomic decay enable host acquisition of complex metabolic pathways by multiple independent horizontal gene transfers from exogenous bacteria. Specifically, each horizontally acquired gene can function with other genes in the pathway coded by the symbiont, while facilitating the decay of the symbiont gene coding the same reaction. PMID:26377567

  13. High-grain feeding causes strong shifts in ruminal epithelial bacterial community and expression of Toll-like receptor genes in goats

    Directory of Open Access Journals (Sweden)

    Junhua eLiu

    2015-03-01

    Full Text Available High-grain (HG feeding used in intensive goat production can affect the physiology of the rumen wall, but the changes induced in the epimural bacterial community and host Toll-like receptors (TLRs are not well understood. In this study, ten male goats were randomly allocated to two groups and fed either a hay diet (0% grain; n=5 or an HG diet (65% grain; n=5. The changes in the ruminal epithelial bacterial community and expression of TLRs during long-term (seven weeks HG feeding were determined using pyrosequencing and quantitative real-time polymerase chain reaction. Principal coordinate analysis and analysis of molecular variance results showed that HG feeding caused a strong shift in bacterial composition and structure. At the genus level, our data revealed that it increased the relative abundance of taxa Butyrivibrio, unclassified Clostridiales, Mogibacterium, unclassified Anaerolineaceae, and Succiniclasticum, and decreased the proportion of unclassified Ruminococcaceae, unclassified Rikenellaceae, unclassified Erysipelotrichaceae, Howardella, and unclassified Neisseriaceae. The HG-fed goats also exhibited upregulation of the relative mRNA expression of TLR2, TLR3, and TLR5 in the rumen epithelium (P<0.05. Correlation analysis revealed that the increase in TLR expression was associated with changes in the relative abundance of ruminal epithelial bacteria. This study provides a first insight into the adaptive response of ruminal epithelial bacterial populations to HG feeding in goats and shows that these changes were associated with alterations in TLR expression. These findings provide new insight into understanding of host–microbial relationships in ruminants.

  14. High-grain feeding causes strong shifts in ruminal epithelial bacterial community and expression of Toll-like receptor genes in goats.

    Science.gov (United States)

    Liu, Jun-Hua; Bian, Gao-Rui; Zhu, Wei-Yun; Mao, Sheng-Yong

    2015-01-01

    High-grain (HG) feeding used in intensive goat production can affect the physiology of the rumen wall, but the changes induced in the epimural bacterial community and host Toll-like receptors (TLRs) are not well understood. In this study, 10 male goats were randomly allocated to two groups and fed either a hay diet (0% grain; n = 5) or an HG diet (65% grain; n = 5). The changes in the ruminal epithelial bacterial community and expression of TLRs during long-term (7 weeks) HG feeding were determined using pyrosequencing and quantitative real-time polymerase chain reaction. Principal coordinate analysis and analysis of molecular variance (AMOVA) results showed that HG feeding caused a strong shift in bacterial composition and structure. At the genus level, our data revealed that it increased the relative abundance of taxa Butyrivibrio, unclassified Clostridiales, Mogibacterium, unclassified Anaerolineaceae, and Succiniclasticum, and decreased the proportion of unclassified Ruminococcaceae, unclassified Rikenellaceae, unclassified Erysipelotrichaceae, Howardella, and unclassified Neisseriaceae. The HG-fed goats also exhibited upregulation of the relative mRNA expression of TLR2, TLR3, and TLR5 in the rumen epithelium (P < 0.05). Correlation analysis revealed that the increase in TLR expression was associated with changes in the relative abundance of ruminal epithelial bacteria. This study provides a first insight into the adaptive response of ruminal epithelial bacterial populations to HG feeding in goats and shows that these changes were associated with alterations in TLR expression. These findings provide new insight into understanding of host-microbial relationships in ruminants. PMID:25784904

  15. Changes in ruminal bacterial community composition following feeding of alfalfa ensiled with a lactic acid bacterial inoculant.

    Science.gov (United States)

    Mohammed, R; Stevenson, D M; Beauchemin, K A; Muck, R E; Weimer, P J

    2012-01-01

    Some silage inoculants help to improve silage quality and promote an increase in milk production, possibly through altering the rumen microflora. We hypothesized that rumen bacterial community composition (BCC) would be different in cows fed alfalfa ensiled with the inoculant Lactobacillus plantarum MTD/1 (LP) compared with those fed alfalfa ensiled without the inoculant (Ctrl). Eight ruminally cannulated Holstein cows were allotted to 2 diets (Ctrl or LP) in a double crossover design with four 28-d periods. Diets were formulated to contain (% dry matter basis) 28.0% neutral detergent fiber and 16.2% crude protein, and contained alfalfa silage, 50.9; corn silage, 20.6; high-moisture shelled corn, 21.4; soy hulls, 4.7; plus minerals and vitamins, 2.4. Ruminal digesta were collected just before feeding on 3 consecutive days near the end of each period, and were separated into solid and liquid phases. Microbial DNA was extracted from each phase, amplified by PCR using domain-level bacterial primers, and subjected to automated ribosomal intergenic spacer analysis. The pH was 4.56 and 4.86 and the lactate-to-acetate ratio 9.8 and 4.4, respectively, for the treated and untreated alfalfa silages. Dry matter intakes and milk production data were not influenced by diets but showed a cow effect. Total volatile fatty acids (mM) tended to be greater for LP compared with Ctrl. Individual volatile fatty acids were not influenced by diets but showed a significant cow effect. Ruminal acetate (mol/100 mol) and acetate-to-propionate ratio were lower and propionate (mol/100 mol) greater for the 2 milk fat-depressed (MFD; <3.2% fat content) cows compared with the other 6 cows. Correspondence analysis of the 265 peaks in the automated ribosomal intergenic spacer analysis profile across the 188 samples revealed that the first 2 components contributed 7.1 and 3.8% to the total variation in the profile. The ordination points representing the liquid and solid phases clustered separately

  16. Preferential Feeding by the Ciliates Chilodonella and Tetrahymena spp. and Effects of These Protozoa on Bacterial Biofilm Structure and Composition▿

    OpenAIRE

    Dopheide, Andrew; Lear, Gavin; Stott, Rebecca; Lewis, Gillian

    2011-01-01

    Protozoa are important components of microbial food webs, but protozoan feeding preferences and their effects in the context of bacterial biofilms are not well understood. The feeding interactions of two contrasting ciliates, the free-swimming filter feeder Tetrahymena sp. and the surface-associated predator Chilodonella sp., were investigated using biofilm-forming bacteria genetically modified to express fluorescent proteins. According to microscopy, both ciliates readily consumed cells from...

  17. Virus-induced secondary bacterial infection: a concise review

    Science.gov (United States)

    Hendaus, Mohamed A; Jomha, Fatima A; Alhammadi, Ahmed H

    2015-01-01

    Respiratory diseases are a very common source of morbidity and mortality among children. Health care providers often face a dilemma when encountering a febrile infant or child with respiratory tract infection. The reason expressed by many clinicians is the trouble to confirm whether the fever is caused by a virus or a bacterium. The aim of this review is to update the current evidence on the virus-induced bacterial infection. We present several clinical as well in vitro studies that support the correlation between virus and secondary bacterial infections. In addition, we discuss the pathophysiology and prevention modes of the virus–bacterium coexistence. A search of the PubMed and MEDLINE databases was carried out for published articles covering bacterial infections associated with respiratory viruses. This review should provide clinicians with a comprehensive idea of the range of bacterial and viral coinfections or secondary infections that could present with viral respiratory illness. PMID:26345407

  18. Bacterial Gibberellins Induce Systemic Resistance of Plants

    OpenAIRE

    I. N. FEKLISTOVA; I. A. GRINEVA; T. L. SKAKUN; L. E. SADOVSKAYA

    2014-01-01

    It is generally agreed today that some rhizosphere bacteria can ensure induced systemic resistance to pathogens. In this paper we tested the ability of gibberellins produced by rhizosphere non-pathogenic bacteria Pseudomonas aurantiaca to induce systemic resistance to alternariosis agent – Alternaria brassicicola – in oilseed rape plants.Oilseed rape (Brássica nápus) is one of the most promising oil-bearing croppers. It allows improving the supply of population with vegetable oil, animal and ...

  19. Histone modifications induced by a family of bacterial toxins

    OpenAIRE

    Hamon, Mélanie Anne; Batsché, Eric; Régnault, Béatrice; Tham, To Nam; Seveau, Stéphanie; Muchardt, Christian; Cossart, Pascale

    2007-01-01

    Upon infection, pathogens reprogram host gene expression. In eukaryotic cells, genetic reprogramming is induced by the concerted activation/repression of transcription factors and various histone modifications that control DNA accessibility in chromatin. We report here that the bacterial pathogen Listeria monocytogenes induces a dramatic dephosphorylation of histone H3 as well as a deacetylation of histone H4 during early phases of infection. This effect is mediated by the major listerial tox...

  20. Ingestion of a marked bacterial pathogen of cotton conclusively demonstrates feeding by first instar southern green stink bug (Hemiptera: Pentatomidae).

    Science.gov (United States)

    Esquivel, J F; Medrano, E G

    2014-02-01

    Long-held dogma dictates that first instars of Nezara viridula (L.) do not feed, yet recent observations of stylet activity within a food source suggest otherwise. As a cosmopolitan pest of cotton and other high-value cash crops, confirmation of feeding by first instars may ultimately influence the knowledge on biology and management strategies for this pest. To determine whether first instars feed, newly hatched nymphs were provided sterile green beans (control) or beans infected with a rifampicin-resistant marked bacterial pathogen (Pantoea agglomerans (Ewing and Fife)) of cotton. Insects were exposed to beans for 2 d, and feeding was confirmed based on detection of marked bacteria ingested by the insect. Normal bacterial flora was detected in all insects; however, control insects did not possess the marked bacteria. Of the first instars surviving on infected beans, ≍65% possessed the marked bacteria internally. Furthermore, the frequency of insects with marked bacteria was higher in insects collected directly from the bean surface than those that were off the bean at time of collection. Densities of innate and marked bacteria were comparable (both ranging from 10(1) to 10(3)), suggesting that the marked bacteria did not exclude preexisting bacterial flora. Marked bacteria were also detected in a subset of second instars, indicating marked bacteria were retained through the molting process after ingesting bacteria as first instars. Our findings conclusively demonstrate feeding by first instars and redefine the long-held perspective of nonfeeding by first instars. These findings may necessitate changes to crop protection strategies against feeding and vectoring of plant pathogens by N. viridula. PMID:24342007

  1. Effects of Interactions of Auxin-Producing Bacteria and Bacterial-Feeding Nematodes on Regulation of Peanut Growths

    OpenAIRE

    Li Xu; Wensi Xu; Ying Jiang; Feng Hu; Huixin Li

    2015-01-01

    The influences of an IAA (indole-3-acetic acid)-producing bacterium (Bacillus megaterium) and two bacterial-feeding nematodes (Cephalobus sp. or Mesorhabditis sp.) on the growth of peanut (Arachis hypogaea L. cv. Haihua 1) after various durations of time were investigated in natural soils. The addition of bacteria and nematodes and incubation time all significantly affected plant growth, plant root growth, plant nutrient concentrations, soil nutrient concentrations, soil microorganisms and so...

  2. Differences between Bacterial Communities in the Gut of a Soil-Feeding Termite (Cubitermes niokoloensis) and Its Mounds▿ †

    Science.gov (United States)

    Fall, Saliou; Hamelin, Jérôme; Ndiaye, Farma; Assigbetse, Komi; Aragno, Michel; Chotte, Jean Luc; Brauman, Alain

    2007-01-01

    In tropical ecosystems, termite mound soils constitute an important soil compartment covering around 10% of African soils. Previous studies have shown (S. Fall, S. Nazaret, J. L. Chotte, and A. Brauman, Microb. Ecol. 28:191-199, 2004) that the bacterial genetic structure of the mounds of soil-feeding termites (Cubitermes niokoloensis) is different from that of their surrounding soil. The aim of this study was to characterize the specificity of bacterial communities within mounds with respect to the digestive and soil origins of the mound. We have compared the bacterial community structures of a termite mound, termite gut sections, and surrounding soil using PCR-denaturing gradient gel electrophoresis (DGGE) analysis and cloning and sequencing of PCR-amplified 16S rRNA gene fragments. DGGE analysis revealed a drastic difference between the genetic structures of the bacterial communities of the termite gut and the mound. Analysis of 266 clones, including 54 from excised bands, revealed a high level of diversity in each biota investigated. The soil-feeding termite mound was dominated by the Actinobacteria phylum, whereas the Firmicutes and Proteobacteria phyla dominate the gut sections of termites and the surrounding soil, respectively. Phylogenetic analyses revealed a distinct clustering of Actinobacteria phylotypes between the mound and the surrounding soil. The Actinobacteria clones of the termite mound were diverse, distributed among 10 distinct families, and like those in the termite gut environment lightly dominated by the Nocardioidaceae family. Our findings confirmed that the soil-feeding termite mound (C. niokoloensis) represents a specific bacterial habitat in the tropics. PMID:17574999

  3. Virus-induced secondary bacterial infection: a concise review

    Directory of Open Access Journals (Sweden)

    Hendaus MA

    2015-08-01

    Full Text Available Mohamed A Hendaus,1 Fatima A Jomha,2 Ahmed H Alhammadi3 1Department of Pediatrics, Academic General Pediatrics Division, Weill-Cornell Medical College, Hamad Medical Corporation, Doha, Qatar; 2School of Pharmacy, Lebanese International University, Khiara, Lebanon; 3Department of Pediatrics, Academic General Pediatrics Division, Weill-Cornell Medical College, Hamad Medical Corporation, Doha, Qatar Abstract: Respiratory diseases are a very common source of morbidity and mortality among children. Health care providers often face a dilemma when encountering a febrile infant or child with respiratory tract infection. The reason expressed by many clinicians is the trouble to confirm whether the fever is caused by a virus or a bacterium. The aim of this review is to update the current evidence on the virus-induced bacterial infection. We present several clinical as well in vitro studies that support the correlation between virus and secondary bacterial infections. In addition, we discuss the pathophysiology and prevention modes of the virus–bacterium coexistence. A search of the PubMed and MEDLINE databases was carried out for published articles covering bacterial infections associated with respiratory viruses. This review should provide clinicians with a comprehensive idea of the range of bacterial and viral coinfections or secondary infections that could present with viral respiratory illness. Keywords: bacteria, infection, risk, virus

  4. Bacterial Community Structure in Tree Hole Habitats of Ochlerotatus Triseriatus: Influences of Larval Feeding

    OpenAIRE

    Xu, Y.; Chen, S.; Kaufman, M. G.; Maknojia, S.; Bagdasarian, M; WALKER, E. D.

    2008-01-01

    We investigated the bacterial community composition of tree holes in relation to the presence and absence of larvae of the mosquito Ochlerotatus triseriatus. Larvae were eliminated from a subset of natural tree holes with Bacillus thuringiensis serovar israelensis, and total bacterial numbers, slow- and fast-growing colony-forming units on minimal media, and 16S rRNA gene sequence data from water column and leaf material were obtained. Total bacterial counts did not change significantly with ...

  5. BACTERIAL POPULATION SHIFTS IN THE RUMEN OF LACTATING DAIRY COWS WITHIN AND ACROSS FEEDING CYCLES

    Science.gov (United States)

    While species composition of the ruminal microflora is thought to change during the feeding cycle due to variations in feed intake and ruminal environmental conditions, no studies have systematically characterized these purported population shifts. We used PCR amplification and automated ribosomal ...

  6. Ruminal Bacterial Community Composition in Dairy Cows Is Dynamic over the Course of Two Lactations and Correlates with Feed Efficiency

    Science.gov (United States)

    Jewell, Kelsea A.; McCormick, Caroline A.; Odt, Christine L.; Weimer, Paul J.

    2015-01-01

    Fourteen Holstein cows of similar ages were monitored through their first two lactation cycles, during which ruminal solids and liquids, milk samples, production data, and feed consumption data were collected for each cow during early (76 to 82 days in milk [DIM]), middle (151 to 157 DIM), and late (251 to 257 DIM) lactation periods. The bacterial community of each ruminal sample was determined by sequencing the region from V6 to V8 of the 16S rRNA gene using 454 pyrosequencing. Gross feed efficiency (GFE) for each cow was calculated by dividing her energy-corrected milk by dry matter intake (ECM/DMI) for each period of both lactation cycles. Four pairs of cows were identified that differed in milk production efficiency, as defined by residual feed intake (RFI), at the same level of ECM production. The most abundant phyla detected for all cows were Bacteroidetes (49.42%), Firmicutes (39.32%), Proteobacteria (5.67%), and Tenericutes (2.17%), and the most abundant genera included Prevotella (40.15%), Butyrivibrio (2.38%), Ruminococcus (2.35%), Coprococcus (2.29%), and Succiniclasticum (2.28%). The bacterial microbiota between the first and second lactation cycles were highly similar, but with a significant correlation between total community composition by ruminal phase and specific bacteria whose relative sequence abundances displayed significant positive or negative correlation with GFE or RFI. These data suggest that the ruminal bacterial community is dynamic in terms of membership and diversity and that specific members are associated with high and low milk production efficiency over two lactation cycles. PMID:25934629

  7. Bacterial Outer Membrane Vesicles Induce Plant Immune Responses.

    Science.gov (United States)

    Bahar, Ofir; Mordukhovich, Gideon; Luu, Dee Dee; Schwessinger, Benjamin; Daudi, Arsalan; Jehle, Anna Kristina; Felix, Georg; Ronald, Pamela C

    2016-05-01

    Gram-negative bacteria continuously pinch off portions of their outer membrane, releasing membrane vesicles. These outer membrane vesicles (OMVs) are involved in multiple processes including cell-to-cell communication, biofilm formation, stress tolerance, horizontal gene transfer, and virulence. OMVs are also known modulators of the mammalian immune response. Despite the well-documented role of OMVs in mammalian-bacterial communication, their interaction with plants is not well studied. To examine whether OMVs of plant pathogens modulate the plant immune response, we purified OMVs from four different plant pathogens and used them to treat Arabidopsis thaliana. OMVs rapidly induced a reactive oxygen species burst, medium alkalinization, and defense gene expression in A. thaliana leaf discs, cell cultures, and seedlings, respectively. Western blot analysis revealed that EF-Tu is present in OMVs and that it serves as an elicitor of the plant immune response in this form. Our results further show that the immune coreceptors BAK1 and SOBIR1 mediate OMV perception and response. Taken together, our results demonstrate that plants can detect and respond to OMV-associated molecules by activation of their immune system, revealing a new facet of plant-bacterial interactions. PMID:26926999

  8. Noise-Induced Increase of Sensitivity in Bacterial Chemotaxis.

    Science.gov (United States)

    He, Rui; Zhang, Rongjing; Yuan, Junhua

    2016-07-26

    Flagellated bacteria, like Escherichia coli, can swim toward beneficial environments by modulating the rotational direction of their flagellar motors through a chemotaxis signal transduction network. The noise of this network, the random fluctuation of the intracellular concentration of the signal protein CheY-P with time, has been identified in studies of single cell behavioral variability, and found to be important in coordination of multiple motors in a bacterium and in enhancement of bacterial drift velocity in chemical gradients. Here, by comparing the behavioral difference between motors of wild-type E. coli and mutants without signal noise, we measured the magnitude of this noise in wild-type cells, and found that the noise increases the sensitivity of the bacterial chemotaxis network downstream at the level of the flagellar motor. This provided a simple mechanism for the noise-induced enhancement of chemotactic drift, which we confirmed by simulating the E. coli chemotactic motion in various spatial profiles of chemo-attractant concentration. PMID:27463144

  9. Study of Bacterial Samples Using Laser Induced Breakdown Spectroscopy

    Science.gov (United States)

    W, A. Farooq; M, Atif; W, Tawfik; M, S. Alsalhi; Z, A. Alahmed; M, Sarfraz; J, P. Singh

    2014-12-01

    Laser-induced breakdown spectroscopy (LIBS) technique has been applied to investigate two different types of bacteria, Escherichia coli (B1) and Micrococcus luteus (B2) deposited on glass slides using Spectrolaser 7000. LIBS spectra were analyzed using spectrolaser software. LIBS spectrum of glass substrate was compared with bacteria spectra. Ca, Mg, Na, K, P, S, Cl, Fe, Al, Mn, Cu, C, H and CN-band appeared in bacterial samples in air. Two carbon lines at 193.02 nm, 247.88 nm and one hydrogen line at 656.28 nm with intensity ratios of 1.9, 1.83 and 1.53 appeared in bacterial samples B1 and B2 respectively. Carbon and hydrogen are the important components of the bio-samples like bacteria and other cancer cells. Investigation on LIBS spectra of the samples in He and Ar atmospheres is also presented. Ni lines appeared only in B2 sample in Ar atmosphere. From the present experimental results we are able to show that LIBS technique has a potential in the identification and discrimination of different types of bacteria.

  10. Metablic Coevolution in the bacterial symbiosis of whiteflies and related plant sap-feeding insects

    Science.gov (United States)

    In animals dependent on intracellular bacteria with very small genomes, the host cell is adapted to support the function of its bacterial symbionts, but the molecular basis of these adaptations is poorly understood. We investigated the metabolic coevolution between the whitefly Bemisia tabaci and th...

  11. Feeding-induced oleoylethanolamide mobilization is disrupted in the gut of diet-induced obese rodents.

    Science.gov (United States)

    Igarashi, Miki; DiPatrizio, Nicholas V; Narayanaswami, Vidya; Piomelli, Daniele

    2015-09-01

    The gastrointestinal tract plays a critical role in the regulation of energy homeostasis by initiating neural and hormonal responses to the ingestion of nutrients. In addition to peptide hormones, such as cholecystokinin (CKK) and peptide YY (PYY), the lipid-derived mediator oleoylethanolamide (OEA) has been implicated in the control of satiety. Previous studies in humans and rodent models have shown that obesity is associated with changes in CCK, PYY and other gut-derived peptide hormones, which may contribute to decreased satiety and increased energy intake. In the present study, we show that small-intestinal OEA production is disrupted in the gut of diet-induced obese (DIO) rats and mice. In lean rodents, feeding or duodenal infusion of Intralipid® or pure oleic acid stimulates jejunal OEA mobilization. This response is strikingly absent in DIO rats and mice. Confirming previous reports, we found that feeding rats or mice a high-fat diet for 7 days is sufficient to suppress jejunal OEA mobilization. Surprisingly, a similar effect is elicited by feeding rats and mice a high-sucrose low-fat diet for 7 days. Collectively, our findings suggest that high fat-induced obesity is accompanied by alterations in the post-digestive machinery responsible for OEA biosynthesis, which may contribute to reduced satiety and hyperphagia. PMID:26024927

  12. Measuring glutathione-induced feeding response in hydra.

    Science.gov (United States)

    Kulkarni, Ram; Galande, Sanjeev

    2014-01-01

    Hydra is among the most primitive organisms possessing a nervous system and chemosensation for detecting reduced glutathione (GSH) for capturing the prey. The movement of prey organisms causes mechanosensory discharge of the stinging cells called nematocysts from hydra, which are inserted into the prey. The feeding response in hydra, which includes curling of the tentacles to bring the prey towards the mouth, opening of the mouth and consequent engulfing of the prey, is triggered by GSH present in the fluid released from the injured prey. To be able to identify the molecular mechanism of the feeding response in hydra which is unknown to date, it is necessary to establish an assay to measure the feeding response. Here, we describe a simple method for the quantitation of the feeding response in which the distance between the apical end of the tentacle and mouth of hydra is measured and the ratio of such distance before and after the addition of GSH is determined. The ratio, called the relative tentacle spread, was found to give a measure of the feeding response. This assay was validated using a starvation model in which starved hydra show an enhanced feeding response in comparison with daily fed hydra. PMID:25490534

  13. A mixed incoherent feed-forward loop contributes to the regulation of bacterial photosynthesis genes

    OpenAIRE

    Mank, Nils N.; Berghoff, Bork A.; Klug, Gabriele

    2013-01-01

    Living cells use a variety of regulatory network motifs for accurate gene expression in response to changes in their environment or during differentiation processes. In Rhodobacter sphaeroides, a complex regulatory network controls expression of photosynthesis genes to guarantee optimal energy supply on one hand and to avoid photooxidative stress on the other hand. Recently, we identified a mixed incoherent feed-forward loop comprising the transcription factor PrrA, the sRNA PcrZ and photosyn...

  14. Bacterial contamination of hospital-prepared enteral tube feeding formulas in Isfahan, Iran

    Directory of Open Access Journals (Sweden)

    Mohammad Jalali

    2009-05-01

    Full Text Available

    • BACKGROUND: Hospital-prepared tube feedings from three intensive care units of two hospitals in Isfahan, Iran were analyzed for microbial contamination.
    • METHODS: A total number of 152 samples (76 samples each at the time of preparation and 18 hours following preparation were collected. Standard plate count, coliform count and Staphylococcus aureus count for all samples were conducted. Samples were analyzed also for the presence of Salmonella spp. and Listeria spp.
    • RESULTS: At the time of food preparation, out of 76 samples, 53 samples (70% had coliform contamination and 87% of these contaminated samples had counts greater than 101 cfu/g. Also, 68  amples (90% had S. aureus contamination greater than 101 cfu/g. In standard plate count, 74 samples (97% had counts greater than 103 cfu/g, while 54 samples (71% had counts greater than 104 cfu/g. In second sampling occasion, out of 76 samples, 68 samples (90% had coliform contamination and 84% of these contaminated samples had counts greater than 101 cfu/g. Also, 72 samples (95% had S. aureus contamination, 98.6% of these contaminated samples had counts greater than 102 cfu/g. In standard plate count, 74 samples (97% had counts greater than 104 cfu/g. No Salmonella or Listeria was detected from samples.
    • CONCLUSION: The results indicated that a majority of the blenderized enteral tube feedings in those hospitals are not safe. In comparison to the standard limits, these enteral tube feedings are highly  ontaminated and posed substantial risk for developing a foodborne disease or nosocomial infection.
    • KEYWORDS: Enteral Feeding, Microbial Contamination, Nosocomial Infection, Standard Plate Count, Coliform.

  15. Bacterial contamination of hospital-prepared enteral tube feeding formulas in Isfahan, Iran

    OpenAIRE

    Mohammad Jalali; Mir Ali Mohammad Sabzghabaee; Shrin Badri; Hasan Ali Soltani; Mohammad Reza Maracy

    2009-01-01

    • BACKGROUND: Hospital-prepared tube feedings from three intensive care units of two hospitals in Isfahan, Iran were analyzed for microbial contamination.
    • METHODS: A total number of 152 samples (76 samples each at the time of preparation and 18 hours following preparation) were collected. Standard plate count, coliform count and Staphylococcus aureus count for all samples were conducted. Samples we...

    • Rumen microbial and fermentation characteristics are affected differently by bacterial probiotic supplementation during induced lactic and subacute acidosis in sheep

      Directory of Open Access Journals (Sweden)

      Lettat Abderzak

      2012-07-01

      Full Text Available Abstract Background Ruminal disbiosis induced by feeding is the cause of ruminal acidosis, a digestive disorder prevalent in high-producing ruminants. Because probiotic microorganisms can modulate the gastrointestinal microbiota, propionibacteria- and lactobacilli-based probiotics were tested for their effectiveness in preventing different forms of acidosis. Results Lactic acidosis, butyric and propionic subacute ruminal acidosis (SARA were induced by feed chalenges in three groups of four wethers intraruminally dosed with wheat, corn or beet pulp. In each group, wethers were either not supplemented (C or supplemented with Propionibacterium P63 alone (P or combined with L. plantarum (Lp + P or L. rhamnosus (Lr + P. Compared with C, all the probiotics stimulated lactobacilli proliferation, which reached up to 25% of total bacteria during wheat-induced lactic acidosis. This induced a large increase in lactate concentration, which decreased ruminal pH. During the corn-induced butyric SARA, Lp + P decreased Prevotella spp. proportion with a concomitant decrease in microbial amylase activity and total volatile fatty acids concentration, and an increase in xylanase activity and pH. Relative to the beet pulp-induced propionic SARA, P and Lr + P improved ruminal pH without affecting the microbial or fermentation characteristics. Regardless of acidosis type, denaturing gradient gel electrophoresis revealed that probiotic supplementations modified the bacterial community structure. Conclusion This work showed that the effectiveness of the bacterial probiotics tested depended on the acidosis type. Although these probiotics were ineffective in lactic acidosis because of a deeply disturbed rumen microbiota, some of the probiotics tested may be useful to minimize the occurrence of butyric and propionic SARA in sheep. However, their modes of action need to be further investigated.

    • Bacterial Cell Wall-Induced Arthritis: Chemical Composition and Tissue Distribution of Four Lactobacillus Strains

      OpenAIRE

      Šimelyte, Egle; Rimpiläinen, Marja; Lehtonen, Leena; Zhang, Xiang; Toivanen, Paavo

      2000-01-01

      To study what determines the arthritogenicity of bacterial cell walls, cell wall-induced arthritis in the rat was applied, using four strains of Lactobacillus. Three of the strains used proved to induce chronic arthritis in the rat; all were Lactobacillus casei. The cell wall of Lactobacillus fermentum did not induce chronic arthritis. All arthritogenic bacterial cell walls had the same peptidoglycan structure, whereas that of L. fermentum was different. Likewise, all arthritogenic cell walls...

    • Genetic Circuits and Chemotaxis Induced Bacterial Cloning on Media Plate

      Directory of Open Access Journals (Sweden)

      Wei Jiang

      2016-03-01

      Full Text Available Objective: Synthetic biology demonstrates its broad application perspective in the fields of medicine, chemical synthesis, and the production of energy. Methods: The character that E. coli responding to the stimulus is named as chemo taxis which has widely applications such as measurement efficiency of RBS and promoter, suicide mechanism, oscillation timer etc. Results: A circuit to control the motility of E. coli (run or tumble and form the patterns such as conic curves was constructed. The strength of the promoter and the efficiency of RBS were successfully characterized by using the circuit and chemo taxis that can be used to characterize most of the promoters, the RBS efficiency, terminator efficiency and expression strength of target genes etc. A new suicide mechanism, utilizing the hyperosmotic pressure, was built to induce the growth of E. coli Pattern model is the fundamental force in the coordination of multicellular behavior in the bacterial community or a large complex system. Conclusion: The sources of stress (such as sodium chloride and sucrose be to generate hypertonic very cheap, convenient and environmentally friendly while antibiotics are expensive and have a bad effect on the environment because of drug-resistant microorganisms.

    • Temperature-induced behavioral switches in a bacterial coral pathogen.

      Science.gov (United States)

      Garren, Melissa; Son, Kwangmin; Tout, Jessica; Seymour, Justin R; Stocker, Roman

      2016-06-01

      Evidence to date indicates that elevated seawater temperatures increase the occurrence of coral disease, which is frequently microbial in origin. Microbial behaviors such as motility and chemotaxis are often implicated in coral colonization and infection, yet little is known about the effect of warming temperatures on these behaviors. Here we present data demonstrating that increasing water temperatures induce two behavioral switches in the coral pathogen Vibrio coralliilyticus that considerably augment the bacterium's performance in tracking the chemical signals of its coral host, Pocillopora damicornis. Coupling field-based heat-stress manipulations with laboratory-based observations in microfluidic devices, we recorded the swimming behavior of thousands of individual pathogen cells at different temperatures, associated with current and future climate scenarios. When temperature reached ⩾23 °C, we found that the pathogen's chemotactic ability toward coral mucus increased by >60%, denoting an enhanced capability to track host-derived chemical cues. Raising the temperature further, to 30 °C, increased the pathogen's chemokinetic ability by >57%, denoting an enhanced capability of cells to accelerate in favorable, mucus-rich chemical conditions. This work demonstrates that increasing temperature can have strong, multifarious effects that enhance the motile behaviors and host-seeking efficiency of a marine bacterial pathogen. PMID:26636553

    • Bacterial Flora Changes in Conjunctiva of Rats with Streptozotocin-Induced Type I Diabetes

      OpenAIRE

      Yang, Chao; Fei, Yuda; Qin, Yali; Luo, Dan; Yang, Shufei; Kou, Xinyun; Zi, Yingxin; Deng, Tingting; Jin, Ming

      2015-01-01

      Background The microbiota of both humans and animals plays an important role in their health and the development of disease. Therefore, the bacterial flora of the conjunctiva may also be associated with some diseases. However, there are no reports on the alteration of bacterial flora in conjunctiva of diabetic rats in the literature. Therefore, we investigated the changes in bacterial flora in bulbar conjunctiva of rats with streptozotocin (STZ)-induced type I diabetes. Methods A high dose of...

  1. Detrimental Effect of the Proteasome Inhibitor, Bortezomib in Bacterial Superantigen- and Lipopolysaccharide-induced Systemic Inflammation

    OpenAIRE

    Tilahun, Ashenafi Y.; Theuer, Jayne E; Patel, Robin; David, Chella S.; Rajagopalan, Govindarajan

    2010-01-01

    Bacterial superantigen (BSAg)–induced toxic shock syndrome (TSS) and bacterial lipopolysaccharide (LPS)–induced shock are characterized by severe systemic inflammation. As nuclear factor κB (NFκB) plays an important role in inflammation and bortezomib, a proteasome inhibitor widely used in cancer chemotherapy, is a potent inhibitor of NFκB activation, we evaluated the therapeutic and prophylactic use of bortezomib in these conditions using murine models. Bortezomib prophylaxis significantly r...

  2. Effects of interactions of auxin-producing bacteria and bacterial-feeding nematodes on regulation of peanut growths.

    Science.gov (United States)

    Xu, Li; Xu, Wensi; Jiang, Ying; Hu, Feng; Li, Huixin

    2015-01-01

    The influences of an IAA (indole-3-acetic acid)-producing bacterium (Bacillus megaterium) and two bacterial-feeding nematodes (Cephalobus sp. or Mesorhabditis sp.) on the growth of peanut (Arachis hypogaea L. cv. Haihua 1) after various durations of time were investigated in natural soils. The addition of bacteria and nematodes and incubation time all significantly affected plant growth, plant root growth, plant nutrient concentrations, soil nutrient concentrations, soil microorganisms and soil auxin concentration. The addition of nematodes caused greater increases in these indices than those of bacteria, while the addition of the combination of bacteria and nematodes caused further increases. After 42-day growth, the increases in soil respiration differed between the additions of two kinds of nematodes because of differences in their life strategies. The effects of the bacteria and nematodes on the nutrient and hormone concentrations were responsible for the increases in plant growth. These results indicate the potential for promoting plant growth via the addition of nematodes and bacteria to soil. PMID:25867954

  3. Effects of interactions of auxin-producing bacteria and bacterial-feeding nematodes on regulation of peanut growths.

    Directory of Open Access Journals (Sweden)

    Li Xu

    Full Text Available The influences of an IAA (indole-3-acetic acid-producing bacterium (Bacillus megaterium and two bacterial-feeding nematodes (Cephalobus sp. or Mesorhabditis sp. on the growth of peanut (Arachis hypogaea L. cv. Haihua 1 after various durations of time were investigated in natural soils. The addition of bacteria and nematodes and incubation time all significantly affected plant growth, plant root growth, plant nutrient concentrations, soil nutrient concentrations, soil microorganisms and soil auxin concentration. The addition of nematodes caused greater increases in these indices than those of bacteria, while the addition of the combination of bacteria and nematodes caused further increases. After 42-day growth, the increases in soil respiration differed between the additions of two kinds of nematodes because of differences in their life strategies. The effects of the bacteria and nematodes on the nutrient and hormone concentrations were responsible for the increases in plant growth. These results indicate the potential for promoting plant growth via the addition of nematodes and bacteria to soil.

  4. Stink Bug Feeding Induces Fluorescence in Developing Cotton Bolls

    Directory of Open Access Journals (Sweden)

    Toews Michael D

    2011-08-01

    Full Text Available Abstract Background Stink bugs (Hemiptera: Pentatomidae comprise a critically important insect pest complex affecting 12 major crops worldwide including cotton. In the US, stink bug damage to developing cotton bolls causes boll abscission, lint staining, reduced fiber quality, and reduced yields with estimated losses ranging from 10 to 60 million dollars annually. Unfortunately, scouting for stink bug damage in the field is laborious and excessively time consuming. To improve scouting accuracy and efficiency, we investigated fluorescence changes in cotton boll tissues as a result of stink bug feeding. Results Fluorescent imaging under long-wave ultraviolet light showed that stink bug-damaged lint, the inner carpal wall, and the outside of the boll emitted strong blue-green fluorescence in a circular region near the puncture wound, whereas undamaged tissue emissions occurred at different wavelengths; the much weaker emission of undamaged tissue was dominated by chlorophyll fluorescence. We further characterized the optimum emission and excitation spectra to distinguish between stink bug damaged bolls from undamaged bolls. Conclusions The observed characteristic fluorescence peaks associated with stink bug damage give rise to a fluorescence-based method to rapidly distinguish between undamaged and stink bug damaged cotton bolls. Based on the fluorescent fingerprint, we envision a fluorescence reflectance imaging or a fluorescence ratiometric device to assist pest management professionals with rapidly determining the extent of stink bug damage in a cotton field.

  5. Modelling and analysis of the feeding regimen induced entrainment of hepatocyte circadian oscillators using petri nets.

    Directory of Open Access Journals (Sweden)

    Samar Hayat Khan Tareen

    Full Text Available Circadian rhythms are certain periodic behaviours exhibited by living organism at different levels, including cellular and system-wide scales. Recent studies have found that the circadian rhythms of several peripheral organs in mammals, such as the liver, are able to entrain their clocks to received signals independent of other system level clocks, in particular when responding to signals generated during feeding. These studies have found SIRT1, PARP1, and HSF1 proteins to be the major influencers of the core CLOCKBMAL1:PER-CRY circadian clock. These entities, along with abstracted feeding induced signals were modelled collectively in this study using Petri Nets. The properties of the model show that the circadian system itself is strongly robust, and is able to continually evolve. The modelled feeding regimens suggest that the usual 3 meals/day and 2 meals/day feeding regimens are beneficial with any more or less meals/day negatively affecting the system.

  6. Demodex-associated bacterial proteins induce neutrophil activation.

    LENUS (Irish Health Repository)

    2012-02-01

    Background: Patients with rosacea demonstrate a higher density of Demodex mites in their skin than controls. A bacterium isolated from a Demodex mite from a patient with papulopustular rosacea (PPR) was previously shown to provoke an immune response in patients with PPR or ocular rosacea thus suggesting a possible role for bacterial proteins in the etiology of this condition. Objectives: To examine the response of neutrophils to proteins derived from a bacterium isolated from a Demodex mite. Methods: Bacterial cells were lysed and proteins were partially purified by AKTA-FPLC. Isolated neutrophils were exposed to bacterial proteins and monitored for alterations in migration, degranulation and cytokine production. Results: Neutrophils exposed to proteins from Bacillus cells demonstrated increased levels of migration and elevated release of MMP-9, an enzyme known to degrade collagen and cathelicidin, an antimicrobial peptide. In addition neutrophils exposed to the bacterial proteins demonstrated elevated rates of Il-8 and TNF-alpha production. Conclusions: Proteins produced by a bacterium isolated from a Demodex mite have the ability to increase the migration, degranulation and cytokine production abilities of neutrophils. These results suggest that bacteria may play a role in the inflammatory erythema associated with rosacea.

  7. Dark repair of UV-induced lesions in bacterial DNA

    International Nuclear Information System (INIS)

    The mechanism of photochemical reaction resulting in the formation of pyrimidine base dimers in DNA is briefly described. Many bacterial species are able to excise the fragments of singlestranded DNA containing pyrimidine dimers, and to rebuild the lacking oligonucleotide fragment. Enzyme system acting in the restitution of damaged DNA to its native form is reviewed. (author)

  8. The Generalist Inside the Specialist: Gut Bacterial Communities of Two Insect Species Feeding on Toxic Plants Are Dominated by Enterococcus sp.

    Science.gov (United States)

    Vilanova, Cristina; Baixeras, Joaquín; Latorre, Amparo; Porcar, Manuel

    2016-01-01

    Some specialist insects feed on plants rich in secondary compounds, which pose a major selective pressure on both the phytophagous and the gut microbiota. However, microbial communities of toxic plant feeders are still poorly characterized. Here, we show the bacterial communities of the gut of two specialized Lepidoptera, Hyles euphorbiae and Brithys crini, which exclusively feed on latex-rich Euphorbia sp. and alkaloid-rich Pancratium maritimum, respectively. A metagenomic analysis based on high-throughput sequencing of the 16S rRNA gene revealed that the gut microbiota of both insects is dominated by the phylum Firmicutes, and especially by the common gut inhabitant Enterococcus sp. Staphylococcus sp. are also found in H. euphorbiae though to a lesser extent. By scanning electron microscopy, we found a dense ring-shaped bacterial biofilm in the hindgut of H. euphorbiae, and identified the most prominent bacterium in the biofilm as Enterococcus casseliflavus through molecular techniques. Interestingly, this species has previously been reported to contribute to the immobilization of latex-like molecules in the larvae of Spodoptera litura, a highly polyphagous lepidopteran. The E. casseliflavus strain was isolated from the gut and its ability to tolerate natural latex was tested under laboratory conditions. This fact, along with the identification of less frequent bacterial species able to degrade alkaloids and/or latex, suggest a putative role of bacterial communities in the tolerance of specialized insects to their toxic diet. PMID:27446044

  9. Production of bacterial leaf blight resistant mulberry through tissue culture and induced mutation

    International Nuclear Information System (INIS)

    Mon Noi multiple shoots obtained from axillary buds in vitro cultures were induced mutation by irradiating with gamma rays at the optimum dose (LD 50) of 40 Gy. In vitro inoculation technique for bacterial blight disease of mulberry caused by Pseudomonas syringae p v. mori was done by leaf-rub method, using bacterial suspension at 107 cells per milliliter which was the lowest concentration to cause highest disease severity. A total of 8357 Mon Noi gamma irradiated plantlets in 7-11 generations were screened for bacterial blight disease resistance. Eighteen plants survived and free from bacterial contamination. These surviving plants were in vitro rapid multiplication then screened for disease resistance in greenhouse. At present, only 4 lines from 18 plants are selected

  10. Ingestion of a marked bacterial pathogen of cotton conclusively demonstrates feeding by first instar southern green stink bug (Hemiptera: Pentatomidae)

    Science.gov (United States)

    Long-held dogma dictates that 1st instars of Nezara viridula (L.) do not feed, yet recent observations of stylet activity within a food source suggest otherwise. As a cosmopolitan pest of cotton and other high-value cash crops, confirmation of feeding by 1st instars may ultimately influence the biol...

  11. Rotation-Induced Polymorphic Transitions in Bacterial Flagella

    Science.gov (United States)

    Vogel, Reinhard; Stark, Holger

    2013-04-01

    Bacteria propel themselves with the help of rotating helical flagella. They change their swimming direction during tumbling events in order to increase, for example, their supply of nutrients (chemotaxis). During tumbling a bacterial flagellum assumes different polymorphic states. Based on a continuum model for the motor-flagellum system, we demonstrate that a changing motor torque can initiate these polymorphic transformations. In particular, we investigate the run-and-stop tumble strategy of Rhodobacter sphaeroides which uses a coiled-to-normal transition in its single flagellum. We also show that torque reversal in single-flagellated Escherichia coli generates a normal-to-curly I transition as observed for tumbling E. coli that swim with a bundle of several flagella.

  12. Induced mutation for bacterial blight resistance in mulberry

    International Nuclear Information System (INIS)

    Buds of mulberry varieties Phai, Noi and SK2502 were irradiated by gamma radiation and then cultured on the Murashige and Skoog medium containing 1.0 mg/l of BA and Casein hydrolysate 1g/l. After proliferation of shoots, they were transferred to the rooting medium (MS + NAA 0.2 mg/l + IBA 0.2 mg/l). Plantlets of mulberry var. Noi were transplanted to soil in greenhouse for screening for bacterial blight disease resistance. All plants showed symptoms of disease. In vitro inoculation of the pathogen, Pseudomonas syringae p.v. mori, on plantlets of the mulberry var. Noi and Phai was conducted. All plants showed symptoms of the disease and died. In vitro screening will be continued with much larger populations in order to select the resistance traits. (author). 4 refs, 4 tabs

  13. Feed Feeds: Managing Feeds Using Feeds

    OpenAIRE

    Wilde, Erik; Pesenson, Igor

    2008-01-01

    Feeds have become an important information channel on the Web, but the management of feed metadata so far has received little attention. It is hard for feed publishers to manage and publish their feed information in a unified format, and for feed consumers to manage and use their feed subscription data across various feed readers, and to share it with other users. We present a system for managing feed metadata using feeds, which we call "feed feeds". Because these feeds are Atom feeds, the wi...

  14. Volatile emission from strawberry plants is induced by mite and leaf beetle feeding and methyl jasmonate

    OpenAIRE

    Himanen, Sari; Nuotio, Netta-Leena; Vuorinen, Terhi; Tuovinen, Tuomo; Holopainen, Jarmo K.

    2006-01-01

    We have studied the emission of volatile organic compounds (VOCs) from young strawberry plants, cultivars Polka and Honeoye, after feeding by several strawberry herbivores under laboratory conditions. VOC profile of strawberry plants is highly dominated by green leaf volatiles (GLVs), which are released also due to mechanical damage. Our results reveal that strawberry has potential for inducible VOC defence, and this encourages testing the attractiveness of these strawberry VOCs to predatory ...

  15. Effect of minimal enteral feeding on recovery in a methotrexate-induced gastrointestinal mucositis rat model

    OpenAIRE

    Kuiken, Nicoline S. S.; Rings, Edmond H. H. M.; Havinga, Rick; Albert K Groen; Tissing, Wim J. E.

    2015-01-01

    Purpose Patients suffering from gastrointestinal mucositis often receive parenteral nutrition as nutritional support. However, the absence of enteral nutrition might not be beneficial for the intestine. We aimed to determine the feasibility of minimal enteral feeding (MEF) administration in a methotrexate (MTX)-induced mucositis rat model and thereby determine the effect of MEF on recovery. Methods Male Wistar rats were attached to swivel systems from day 1 to 5 after 45 mg/kg MTX IV injectio...

  16. MOTIVATION OF HENS TO OBTAIN FEED DURING A MOLT INDUCED BY EITHER FEED WITHDRAWAL, WHEAT MIDDLINGS OR MELENGESTROL ACETATE

    Science.gov (United States)

    Traditionally, molting had been done by withdrawing feed, which leads to weight loss and increased mortality. Public criticism of feed withdrawal, based on the perception that it inhumanely increases hunger, has led the industry to ban the practice. Thus far, alternatives result in poor post-molt p...

  17. Liquid enteral diets induce bacterial translocation by increasing cecal flora without changing intestinal motility.

    Science.gov (United States)

    Haskel, Y; Udassin, R; Freund, H R; Zhang, J M; Hanani, M

    2001-01-01

    The aim of this study was to determine the contribution of intestinal motility and cecal bacterial overgrowth to liquid diet-induced bacterial translocation (BT). Three different commercially available liquid diets were offered to mice for 1 week. BT to the mesenteric lymph nodes (MLN), spleen, and liver were examined as well as cecal bacterial counts and populations, small bowel length and weight, and histopathologic changes in the ileal and jejunal mucosa. In addition, the effect of the various diets on intestinal motility was measured by the transit index of a charcoal mixture introduced into the stomach. The incidence of BT to the mesenteric lymph nodes was significantly and similarly increased (p Vivonex (30%), Ensure (30%), and Osmolite (33%) compared with chow-fed controls (0%). Compared with chow-fed controls, all three liquid diets were associated with the development of cecal bacterial overgrowth (p < .01). There were no significant changes in the transit index for the three liquid diet groups compared with the chow-fed controls. BT to the MLN was induced by all three liquid diets tested, casting some doubts as to their role in preventing BT in clinical use. BT was associated with a statistically significant increase in cecal bacterial count but was not associated with gut motility changes in this model. In fact, no significant changes in intestinal motility were noted in all groups tested. PMID:11284471

  18. Feeding cells induced by phytoparasitic nematodes require γ-tubulin ring complex for microtubule reorganization.

    Directory of Open Access Journals (Sweden)

    Mohamed Youssef Banora

    2011-12-01

    Full Text Available Reorganization of the microtubule network is important for the fast isodiametric expansion of giant-feeding cells induced by root-knot nematodes. The efficiency of microtubule reorganization depends on the nucleation of new microtubules, their elongation rate and activity of microtubule severing factors. New microtubules in plants are nucleated by cytoplasmic or microtubule-bound γ-tubulin ring complexes. Here we investigate the requirement of γ-tubulin complexes for giant feeding cells development using the interaction between Arabidopsis and Meloidogyne spp. as a model system. Immunocytochemical analyses demonstrate that γ-tubulin localizes to both cortical cytoplasm and mitotic microtubule arrays of the giant cells where it can associate with microtubules. The transcripts of two Arabidopsis γ-tubulin (TUBG1 and TUBG2 and two γ-tubulin complex proteins genes (GCP3 and GCP4 are upregulated in galls. Electron microscopy demonstrates association of GCP3 and γ-tubulin as part of a complex in the cytoplasm of giant cells. Knockout of either or both γ-tubulin genes results in the gene dose-dependent alteration of the morphology of feeding site and failure of nematode life cycle completion. We conclude that the γ-tubulin complex is essential for the control of microtubular network remodelling in the course of initiation and development of giant-feeding cells, and for the successful reproduction of nematodes in their plant hosts.

  19. Sham feeding is inhibited by dietary-induced obesity in rats.

    Science.gov (United States)

    Vanderweele, D A; Van Itallie, T B

    1983-10-01

    A group of six female, albino rats were maintained on a cafeteria diet of cookies, milk, and elevated-fat (shortening), rat-chow mixture and rat chow while a similar group received only rat chow ad lib for 17 weeks. When the groups differed significantly in mean body weight (obese-387.5 g, controls-287.2 g; p less than 0.001), gastric fistulas were implanted in each animal. After recovery, the rats were adapted to a liquid diet and assessed for sham feeding. Control-fed, normal-body-weight subjects showed substantial sham feeding when ingesting the Vivonex with the fistulas open compared to fistula-closed intake; meal frequency, meal size (apart from the initial meal) and total food intake were significantly increased while the satiety ratios following each meal were significantly decreased. Obese animals showed no significant increased feeding and satiety ratios were unreliably altered; while normal-body-weight controls increased 4-hr food intakes by 93% and halved their mean satiety ratios the obese animals showed an 8% increase in 4-hr food intake and only a 22% decrease in mean satiety ratios. We offer the hypothesis that, when animals are induced to become obese by palatable and varied diets which are then terminated, the anorexia produced is independent of gastrointestinal interactions inasmuch as that anorexia extends to sham feeding. PMID:6361815

  20. Bacterially induced precipitation of CaCO sub 3 : An example from studies of cyanobacterial mats

    Energy Technology Data Exchange (ETDEWEB)

    Chafetz, H.S.

    1990-04-30

    Bacteria induce the precipitation of calcium carbonate in the laboratory and in nature by altering their chemical environment. Geologists are recognizing the possibility that bacterially induced precipitates may form significant mineral deposits, unfortunately, there are currently no sound criteria by which they can be recognized in recent sediments, or in the rock record. Cultures of aerobic and facultative bacteria from cyanobacterial mats on Andros Island, Bahamas, and Baffin Bay, Texas, induced the precipitation of calcium carbonate under controlled conditions. Crusts, the largest features formed, are composed of 5--200{mu}m diameter bundles which are, in turn, composed of numerous individual crystals. The smallest observed features are 0.1--0.4{mu}m spheres and rods which comprise some individual crystals and crystal bundles. Crystal bundles resembling rhombohedra, tetragonal disphenoids, tetragonal dipyramids, and calcite dumbbells appear to be uniquely bacterial in origin, and they have all been observed in recent sediments. Swollen rods, discs, curved dumbbells, and 50--200{mu}m optically continuous crystals resembling brushes may be uniquely bacterial in origin, however, they have not been reported by other laboratories nor observed in natural settings. Presence of any of these forms in recent sediments should be taken as strong evidence for bacterial influence. Spheres and aragonite dumbbells have also been observed in natural environments, however, they are not always bacterial in origin. Precipitation of calcium carbonate occurs preferentially on dead cyanobacteria in the presence of bacteria. Lithification of algal mats to form stromatolites may take place in the zone of decaying organic matter due to bacterial activity.

  1. Phloem development in nematode-induced feeding sites: The implications of auxin and cytokinin

    Directory of Open Access Journals (Sweden)

    Birgit eAbsmanner

    2013-07-01

    Full Text Available Sedentary plant parasitic nematodes such as root-knot nematodes and cyst nematodes induce giant cells or syncytia, respectively, in their host plant’s roots. These highly specialized structures serve as feeding sites from which exclusively the nematodes withdraw nutrients. While giant cells are symplastically isolated and obtain assimilates by transporter-mediated processes syncytia are massively connected to the phloem by plasmodesmata. To support the feeding sites and the nematode during their development, phloem is induced around syncytia and giant cells. In the case of syncytia the unloading phloem consists of sieve elements and companion cells and in the case of root knots it consists exclusively of sieve elements. We applied immunohistochemistry to identify the cells within the developing phloem that responded to auxin and cytokinin. Both feeding sites themselves did not respond to either hormone. We were able to show that in root knots an auxin response precedes the differentiation of these auxin responsive cells into phloem elements. This process appears to be independent of B-type Arabidopsis response regulators. Using additional markers for tissue identity we provide evidence that around giant cells protophloem is formed and proliferates dramatically. In contrast, the phloem around syncytia responded to both hormones. The presence of companion cells as well as hormone-responsive sieve elements suggests that metaphloem development occurs. The implication of auxin and cytokinin in the further development of the metaphloem is discussed.

  2. A new model for the spectral induced polarization signature of bacterial growth in porous media

    Science.gov (United States)

    Zhang, C.; Revil, A.; Atekwana, E. A.; Jardani, A.; Smith, S.

    2012-12-01

    Recent biogeophysics studies demonstrated the sensitivity of complex conductivity to bacterial growth and microbial mediated mineral transformations in porous media. Frequency-domain induced polarization is a minimally invasive manner to measure the complex conductivity of a material over a broad range of frequencies. The real component of complex conductivity is associated with electromigration of the charge carriers, and the imaginary component represents reversible energy storage of charge carriers at polarization length scales. Quantitative relationship between frequency-domain induced polarization responses and bacterial growth and decay in porous media is analyzed in this study using a new developed model. We focus on the direct contribution of bacteria themselves to the complex conductivity in porous media in the absence of biomineralization. At low frequencies, the induced polarization of bacteria (α-polarization) is related to the properties of the electrical double layer surrounding the membrane surface of bacteria. Surface conductivity and α-polarization are due to the Stern layer of the counterions occurring in a brush of polymers coating the surface of the bacteria, and can be related to the cation exchange capacity of the bacteria. From the modeling results, at low frequencies (bacterial populations are usually described by Monod kinetics, we show that the changes in imaginary conductivity with time can be used to determine bacterial growth kinetics parameters such as the growth and endogenous decay coefficient.

  3. The role of the bacterial mismatch repair system in SOS-induced mutagenesis: a theoretical background

    International Nuclear Information System (INIS)

    A theoretical study is performed of the possible role of the methyl-directed mismatch repair system in the ultraviolet-induced mutagenesis of Escherichia coli bacterial cells. For this purpose, a mathematical model of the bacterial mismatch repair system is developed. Within this model, the key pathways of this type of repair are simulated on the basis of modern experimental data related to its mechanisms. Here we have modelled in detail five main pathways of DNA misincorporation removal with different DNA exonucleases. Using our calculations, we have tested the hypothesis that the bacterial mismatch repair system is responsible for the removal of the nucleotides misincorporated by DNA polymerase V (the UmuD'2C complex) during ultraviolet-induced SOS response. For the theoretical analysis of the mutation frequency, we have combined the proposed mathematical approach with the model of SOS-induced mutagenesis in the E.coli bacterial cell developed earlier. Our calculations support the hypothesis that methyl-directed mismatch repair influences the mutagenic effect of ultraviolet radiation

  4. Induced release of a plant-defense volatile 'deceptively' attracts insect vectors to plants infected with a bacterial pathogen.

    Directory of Open Access Journals (Sweden)

    Rajinder S Mann

    Full Text Available Transmission of plant pathogens by insect vectors is a complex biological process involving interactions between the plant, insect, and pathogen. Pathogen-induced plant responses can include changes in volatile and nonvolatile secondary metabolites as well as major plant nutrients. Experiments were conducted to understand how a plant pathogenic bacterium, Candidatus Liberibacter asiaticus (Las, affects host preference behavior of its psyllid (Diaphorina citri Kuwayama vector. D. citri were attracted to volatiles from pathogen-infected plants more than to those from non-infected counterparts. Las-infected plants were more attractive to D. citri adults than non-infected plants initially; however after feeding, psyllids subsequently dispersed to non-infected rather than infected plants as their preferred settling point. Experiments with Las-infected and non-infected plants under complete darkness yielded similar results to those recorded under light. The behavior of psyllids in response to infected versus non-infected plants was not influenced by whether or not they were carriers of the pathogen. Quantification of volatile release from non-infected and infected plants supported the hypothesis that odorants mediate psyllid preference. Significantly more methyl salicylate, yet less methyl anthranilate and D-limonene, was released by infected than non-infected plants. Methyl salicylate was attractive to psyllids, while methyl anthranilate did not affect their behavior. Feeding on citrus by D. citri adults also induced release of methyl salicylate, suggesting that it may be a cue revealing location of conspecifics on host plants. Infected plants were characterized by lower levels of nitrogen, phosphorus, sulfur, zinc, and iron, as well as, higher levels of potassium and boron than non-infected plants. Collectively, our results suggest that host selection behavior of D. citri may be modified by bacterial infection of plants, which alters release of

  5. Introducing enteral feeding induces intestinal subclinical inflammation and respective chromatin changes in preterm pigs

    DEFF Research Database (Denmark)

    Willems, Rhea; Krych, Lukasz; Rybicki, Verena;

    2015-01-01

    were analyzed 5 days after birth. RESULTS: Enteral feeding led to differential upregulation of inflammatory and pattern recognition receptor genes, including IL8 (median: 5.8, 95% CI: 3.9-7.8 for formula; median: 2.2, 95% CI: 1.3-3.3 for colostrum) and TLR4 (median: 3.7, 95% CI: 2.6-4.8 for formula; no...... stimulation with lipopolysaccharide (median: 7.0; interquartile range: 5.63-8.85) compared with naive cells (median 4.2; interquartile range: 2.45-6.33; p = 0.03). CONCLUSION: Enteral feeding, particular with formula, induces subclinical inflammation in the premature intestine and more open chromatin...

  6. TLR2-induced IL-10 production impairs neutrophil recruitment to infected tissues during neonatal bacterial sepsis.

    Science.gov (United States)

    Andrade, Elva B; Alves, Joana; Madureira, Pedro; Oliveira, Liliana; Ribeiro, Adília; Cordeiro-da-Silva, Anabela; Correia-Neves, Margarida; Trieu-Cuot, Patrick; Ferreira, Paula

    2013-11-01

    Sepsis is the third most common cause of neonatal death, with Group B Streptococcus (GBS) being the leading bacterial agent. The pathogenesis of neonatal septicemia is still unsolved. We described previously that host susceptibility to GBS infection is due to early IL-10 production. In this study, we investigated whether triggering TLR2 to produce IL-10 is a risk factor for neonatal bacterial sepsis. We observed that, in contrast to wild-type (WT) pups, neonatal TLR2-deficient mice were resistant to GBS-induced sepsis. Moreover, if IL-10 signaling were blocked in WT mice, they also were resistant to sepsis. This increased survival rate was due to an efficient recruitment of neutrophils to infected tissues that leads to bacterial clearance, thus preventing the development of sepsis. To confirm that IL-10 produced through TLR2 activation prevents neutrophil recruitment, WT pups were treated with the TLR2 agonist Pam3CSK4 prior to nebulization with the neutrophil chemotactic agent LTB4. Neutrophil recruitment into the neonatal lungs was inhibited in pups treated with Pam3CSK4. However, the migration was restored in Pam3CSK4-treated pups when IL-10 signaling was blocked (either by anti-IL-10R mAb treatment or by using IL-10-deficient mice). Our findings highlight that TLR2-induced IL-10 production is a key event in neonatal susceptibility to bacterial sepsis. PMID:24078699

  7. Feeding induced by cannabinoids is mediated independently of the melanocortin system.

    Directory of Open Access Journals (Sweden)

    Puspha Sinnayah

    Full Text Available BACKGROUND: Cannabinoids, the active components of marijuana, stimulate appetite, and cannabinoid receptor-1 (CB1-R antagonists suppress appetite and promote weight loss. Little is known about how CB1-R antagonists affect the central neurocircuitry, specifically the melanocortin system that regulates energy balance. METHODOLOGY/PRINCIPAL FINDINGS: Here, we show that peripherally administered CB1-R antagonist (AM251 or agonist equally suppressed or stimulated feeding respectively in A(y , which lack a functional melanocortin system, and wildtype mice, demonstrating that cannabinoid effects on feeding do not require melanocortin circuitry. CB1-R antagonist or agonist administered into the ventral tegmental area (VTA equally suppressed or stimulated feeding respectively, in both genotypes. In addition, peripheral and central cannabinoid administration similarly induced c-Fos activation in brain sites suggesting mediation via motivational dopaminergic circuitry. Amperometry-detected increases in evoked dopamine (DA release by the CB1-R antagonist in nucleus accumbens slices indicates that AM251 modulates DA release from VTA terminals. CONCLUSIONS/SIGNIFICANCE: Our results demonstrate that the effects of cannabinoids on energy balance are independent of hypothalamic melanocortin circuitry and is primarily driven by the reward system.

  8. Conjugative DNA Transfer Induces the Bacterial SOS Response and Promotes Antibiotic Resistance Development through Integron Activation

    OpenAIRE

    Baharoglu, Zeynep; Bikard, David; Mazel, Didier

    2010-01-01

    Conjugation is one mechanism for intra- and inter-species horizontal gene transfer among bacteria. Conjugative elements have been instrumental in many bacterial species to face the threat of antibiotics, by allowing them to evolve and adapt to these hostile conditions. Conjugative plasmids are transferred to plasmidless recipient cells as single-stranded DNA. We used lacZ and gfp fusions to address whether conjugation induces the SOS response and the integron integrase. The SOS response contr...

  9. Bacterial contamination of enteral diets.

    OpenAIRE

    de Leeuw, I H; Vandewoude, M F

    1986-01-01

    Enteral feeding solutions can be contaminated by bacterial micro-organisms already present in the ingredients, or introduced during preparation or transport, or in the hospital ward. During jejunostomy feeding without pump or filter, ascending bacterial invasion of the feeding bag is possible. In patients with lowered immune response contaminated feedings can cause serious septic clinical problems. The progressive loss of the nutritional value of the enteral feeding solution by bacterial cont...

  10. New inducible genetic method reveals critical roles of GABA in the control of feeding and metabolism.

    Science.gov (United States)

    Meng, Fantao; Han, Yong; Srisai, Dollada; Belakhov, Valery; Farias, Monica; Xu, Yong; Palmiter, Richard D; Baasov, Timor; Wu, Qi

    2016-03-29

    Currently available inducibleCre/loxPsystems, despite their considerable utility in gene manipulation, have pitfalls in certain scenarios, such as unsatisfactory recombination rates and deleterious effects on physiology and behavior. To overcome these limitations, we designed a new, inducible gene-targeting system by introducing an in-frame nonsense mutation into the coding sequence of Cre recombinase (nsCre). Mutant mRNAs transcribed fromnsCretransgene can be efficiently translated into full-length, functional Cre recombinase in the presence of nonsense suppressors such as aminoglycosides. In a proof-of-concept model, GABA signaling from hypothalamic neurons expressing agouti-related peptide (AgRP) was genetically inactivated within 4 d after treatment with a synthetic aminoglycoside. Disruption of GABA synthesis in AgRP neurons in young adult mice led to a dramatic loss of body weight due to reduced food intake and elevated energy expenditure; they also manifested glucose intolerance. In contrast, older mice with genetic inactivation of GABA signaling by AgRP neurons had only transient reduction of feeding and body weight; their energy expenditure and glucose tolerance were unaffected. These results indicate that GABAergic signaling from AgRP neurons plays a key role in the control of feeding and metabolism through an age-dependent mechanism. This new genetic technique will augment current tools used to elucidate mechanisms underlying many physiological and neurological processes. PMID:26976589

  11. Mucosal injury induced by ischemia and reperfusion in the piglet intestine: Influences of age and feeding

    Energy Technology Data Exchange (ETDEWEB)

    Crissinger, K.D.; Granger, D.N. (Louisiana State Univ. Medical Center, Shreveport (USA))

    1989-10-01

    The pathogenesis of neonatal necrotizing enterocolitis is unknown, but enteral alimentation, infectious agents, and mesenteric ischemia have been frequently invoked as primary initiators of the disease. To define the vulnerability of the intestinal mucosa to ischemia and reperfusion in the developing piglet, we evaluated changes in mucosal permeability using plasma-to-lumen clearance of chromium 51-labeled ethylenediaminetetraacetic acid in the ileum of anesthetized 1-day-, 3-day-, 2-wk-, and 1-mo-old piglets as a function of (a) duration of intestinal ischemia (20, 40, or 60 min of total superior mesenteric artery occlusion), (b) feeding status (fasted or nursed), and (c) composition of luminal perfusate (balanced salt solution vs. predigested cow milk-based formula). Baseline chromium 51-labeled ethylenediaminetetraacetic acid clearance was not significantly altered by ischemia, irrespective of duration, or feeding in all age groups. However, clearances were significantly elevated during reperfusion after 1 h of total intestinal ischemia in all age groups, whether fasted or fed. Reperfusion-induced increases in clearance did not differ among age groups when the bowel lumen was perfused with a balanced salt solution. However, luminal perfusion with formula resulted in higher clearances in 1-day-old piglets compared with all older animals. Thus, the neonatal intestine appears to be more vulnerable to mucosal injury induced by ischemia and reperfusion in the presence of formula than the intestine of older animals.

  12. Early administration of probiotics alters bacterial colonization and limits diet-induced gut dysfunction and severity of necrotizing enterocolitis in preterm pigs.

    Science.gov (United States)

    Siggers, Richard H; Siggers, Jayda; Boye, Mette; Thymann, Thomas; Mølbak, Lars; Leser, Thomas; Jensen, Bent B; Sangild, Per T

    2008-08-01

    Following preterm birth, bacterial colonization and enteral formula feeding predispose neonates to gut dysfunction and necrotizing enterocolitis (NEC), a serious gastrointestinal inflammatory disease. We hypothesized that administration of probiotics would beneficially influence early bacterial colonization, thereby reducing the susceptibility to formula-induced gut atrophy, dysfunction, and NEC. Caesarean-delivered preterm pigs were provided total parenteral nutrition (1.5 d) followed by enteral feeding (2 d) with porcine colostrum (COLOS; n = 5), formula (FORM; n = 9), or formula with probiotics (FORM-P; Bifidobacterium animalis and Lactobacillus: L. acidophilus, L. casei, L. pentosus, L. plantarum; n = 13). Clinical NEC scores were reduced (P < 0.05) in FORM-P (2.0 +/- 0.2) and COLOS groups (1.7 +/- 0.5) compared with FORM pigs (3.4 +/- 0.6). Lower NEC scores were associated with elevated intestinal weight, mucosa proportion, villus height, RNA integrity, and brush border aminopeptidase A and N activities, and lower gastric organic acid concentration in the FORM-P and COLOS groups (P < 0.05). Diversity of the mucosa-associated bacteria in the distal small intestine was similar among formula-fed pigs, yet the abundance of specific bacterial groups differed between FORM-P and FORM pigs. FORM-P pigs had lower colonization density of a potential pathogen, Clostridium perfringens, and had commensal Lactobacillus bacteria more closely associated with enterocytes along the villus-crypt axis relative to FORM pigs. These results suggest that probiotic administration immediately after birth promotes the colonization of a beneficial commensal microbiota capable of limiting the formula-induced mucosal atrophy, dysfunction, and pathogen load in preterm neonates, thereby reducing the incidence and severity of NEC. PMID:18641188

  13. Effects of long term feeding of raw soya bean flour on virus- induced pancreatic carcinogenesis in guinea fowl

    NARCIS (Netherlands)

    Kirev, T.; Woutersen, R.A.; Kiril, A.

    1999-01-01

    The effects of a diet enriched with 25% raw soya bean flour (RSF) on the pancreas and on the avian retrovirus Pts 56-induced pancreatic carcinogenesis in guinea fowl were studied. It has been shown that prolonged RSF feeding of new-hatched virus-infected and uninfected guinea fowl-poults induced enl

  14. Macroalgal extracts induce bacterial assemblage shifts and sublethal tissue stress in Caribbean corals.

    Directory of Open Access Journals (Sweden)

    Kathleen M Morrow

    Full Text Available Benthic macroalgae can be abundant on present-day coral reefs, especially where rates of herbivory are low and/or dissolved nutrients are high. This study investigated the impact of macroalgal extracts on both coral-associated bacterial assemblages and sublethal stress response of corals. Crude extracts and live algal thalli from common Caribbean macroalgae were applied onto the surface of Montastraea faveolata and Porites astreoides corals on reefs in both Florida and Belize. Denaturing gradient gel electrophoresis (DGGE of 16S rRNA gene amplicons was used to examine changes in the surface mucus layer (SML bacteria in both coral species. Some of the extracts and live algae induced detectable shifts in coral-associated bacterial assemblages. However, one aqueous extract caused the bacterial assemblages to shift to an entirely new state (Lobophora variegata, whereas other organic extracts had little to no impact (e.g. Dictyota sp.. Macroalgal extracts more frequently induced sublethal stress responses in M. faveolata than in P. astreoides corals, suggesting that cellular integrity can be negatively impacted in selected corals when comparing co-occurring species. As modern reefs experience phase-shifts to a higher abundance of macroalgae with potent chemical defenses, these macroalgae are likely impacting the composition of microbial assemblages associated with corals and affecting overall reef health in unpredicted and unprecedented ways.

  15. Macroalgal extracts induce bacterial assemblage shifts and sublethal tissue stress in Caribbean corals.

    Science.gov (United States)

    Morrow, Kathleen M; Ritson-Williams, Raphael; Ross, Cliff; Liles, Mark R; Paul, Valerie J

    2012-01-01

    Benthic macroalgae can be abundant on present-day coral reefs, especially where rates of herbivory are low and/or dissolved nutrients are high. This study investigated the impact of macroalgal extracts on both coral-associated bacterial assemblages and sublethal stress response of corals. Crude extracts and live algal thalli from common Caribbean macroalgae were applied onto the surface of Montastraea faveolata and Porites astreoides corals on reefs in both Florida and Belize. Denaturing gradient gel electrophoresis (DGGE) of 16S rRNA gene amplicons was used to examine changes in the surface mucus layer (SML) bacteria in both coral species. Some of the extracts and live algae induced detectable shifts in coral-associated bacterial assemblages. However, one aqueous extract caused the bacterial assemblages to shift to an entirely new state (Lobophora variegata), whereas other organic extracts had little to no impact (e.g. Dictyota sp.). Macroalgal extracts more frequently induced sublethal stress responses in M. faveolata than in P. astreoides corals, suggesting that cellular integrity can be negatively impacted in selected corals when comparing co-occurring species. As modern reefs experience phase-shifts to a higher abundance of macroalgae with potent chemical defenses, these macroalgae are likely impacting the composition of microbial assemblages associated with corals and affecting overall reef health in unpredicted and unprecedented ways. PMID:23028648

  16. Conjugative DNA transfer induces the bacterial SOS response and promotes antibiotic resistance development through integron activation.

    Directory of Open Access Journals (Sweden)

    Zeynep Baharoglu

    2010-10-01

    Full Text Available Conjugation is one mechanism for intra- and inter-species horizontal gene transfer among bacteria. Conjugative elements have been instrumental in many bacterial species to face the threat of antibiotics, by allowing them to evolve and adapt to these hostile conditions. Conjugative plasmids are transferred to plasmidless recipient cells as single-stranded DNA. We used lacZ and gfp fusions to address whether conjugation induces the SOS response and the integron integrase. The SOS response controls a series of genes responsible for DNA damage repair, which can lead to recombination and mutagenesis. In this manuscript, we show that conjugative transfer of ssDNA induces the bacterial SOS stress response, unless an anti-SOS factor is present to alleviate this response. We also show that integron integrases are up-regulated during this process, resulting in increased cassette rearrangements. Moreover, the data we obtained using broad and narrow host range plasmids strongly suggests that plasmid transfer, even abortive, can trigger chromosomal gene rearrangements and transcriptional switches in the recipient cell. Our results highlight the importance of environments concentrating disparate bacterial communities as reactors for extensive genetic adaptation of bacteria.

  17. Rumen microbial and fermentation characteristics are affected differently by bacterial probiotic supplementation during induced lactic and subacute acidosis in sheep

    OpenAIRE

    Lettat Abderzak; Nozière Pierre; Silberberg Mathieu; Morgavi Diego P; Berger Claudette; Martin Cécile

    2012-01-01

    Abstract Background Ruminal disbiosis induced by feeding is the cause of ruminal acidosis, a digestive disorder prevalent in high-producing ruminants. Because probiotic microorganisms can modulate the gastrointestinal microbiota, propionibacteria- and lactobacilli-based probiotics were tested for their effectiveness in preventing different forms of acidosis. Results Lactic acidosis, butyric and propionic subacute ruminal acidosis (SARA) were induced by feed chalenges in three groups of four w...

  18. Physicochemical conditions, metabolites and community structure of the bacterial microbiota in the gut of wood-feeding cockroaches (Blaberidae: Panesthiinae).

    Science.gov (United States)

    Bauer, Eugen; Lampert, Niclas; Mikaelyan, Aram; Köhler, Tim; Maekawa, Kiyoto; Brune, Andreas

    2015-02-01

    While the gut microbiota of termites and its role in symbiotic digestion have been studied for decades, little is known about the bacteria colonizing the intestinal tract of the distantly related wood-feeding cockroaches (Blaberidae: Panesthiinae). Here, we show that physicochemical gut conditions and microbial fermentation products in the gut of Panesthia angustipennis resemble that of other cockroaches. Microsensor measurements confirmed that all gut compartments were anoxic at the center and had a slightly acidic to neutral pH and a negative redox potential. While acetate dominated in all compartments, lactate and hydrogen accumulated only in the crop. The high, hydrogen-limited rates of methane emission from living cockroaches were in agreement with the restriction of F420-fluorescent methanogens to the hindgut. The gut microbiota of both P. angustipennis and Salganea esakii differed strongly between compartments, with the highest density and diversity in the hindgut, but similarities between homologous compartments of both cockroaches indicated a specificity of the microbiota for their respective habitats. While some lineages were most closely related to the gut microbiota of omnivorous cockroaches and wood- or litter-feeding termites, others have been encountered also in vertebrates, reinforcing the hypothesis that strong environmental selection drives community structure in the cockroach gut. PMID:25764554

  19. Detrimental effect of the proteasome inhibitor, bortezomib in bacterial superantigen- and lipopolysaccharide-induced systemic inflammation.

    Science.gov (United States)

    Tilahun, Ashenafi Y; Theuer, Jayne E; Patel, Robin; David, Chella S; Rajagopalan, Govindarajan

    2010-06-01

    Bacterial superantigen (BSAg)-induced toxic shock syndrome (TSS) and bacterial lipopolysaccharide (LPS)-induced shock are characterized by severe systemic inflammation. As nuclear factor kappaB (NF kappaB) plays an important role in inflammation and bortezomib, a proteasome inhibitor widely used in cancer chemotherapy, is a potent inhibitor of NF kappaB activation, we evaluated the therapeutic and prophylactic use of bortezomib in these conditions using murine models. Bortezomib prophylaxis significantly reduced serum levels of many cytokines and chemokines induced by BSAg. However, at 3 hours, serum level of TNF-a, an important cytokine implicated in TSS, was significantly reduced but not abolished. At 6 hours, there was no difference in the serum TNF-a levels between bortezomib treated and untreated mice challenged with staphylococcal enterotoxin B (SEB). Paradoxically, all mice treated with bortezomib either before or after BSAg challenge succumbed to TSS. Neither bortezomib nor BSAg was lethal if given alone. Serum biochemical parameters and histopathological findings suggested acute liver failure as the possible cause of mortality. Liver tissue from SEB-challenged mice treated with bortezomib showed a significant reduction in NF kappaB activation. Because NF kappaB-dependent antiapoptotic pathways protect hepatocytes from TNF-alpha-induced cell death, inhibition of NF kappaB brought forth by bortezomib in the face of elevated TNF-alpha levels caused by BSAg or LPS is detrimental. PMID:20372109

  20. Bacterial lipoprotein-induced tolerance is reversed by overexpression of IRAK-1.

    LENUS (Irish Health Repository)

    Li, Chong Hui

    2012-03-01

    Tolerance to bacterial cell wall components including bacterial lipoprotein (BLP) represents an essential regulatory mechanism during bacterial infection. Reduced Toll-like receptor 2 (TLR2) and IL-1 receptor-associated kinase 1 (IRAK-1) expression is a characteristic of the downregulated TLR signaling pathway observed in BLP-tolerised cells. In this study, we attempted to clarify whether TLR2 and\\/or IRAK-1 are the key molecules responsible for BLP-induced tolerance. Transfection of HEK293 cells and THP-1 cells with the plasmid encoding TLR2 affected neither BLP tolerisation-induced NF-κB deactivation nor BLP tolerisation-attenuated pro-inflammatory cytokine tumor necrosis factor alpha (TNF-α) production, indicating that BLP tolerance develops despite overexpression of TLR2 in these cells. In contrast, overexpression of IRAK-1 reversed BLP-induced tolerance, as transfection of IRAK-1 expressing vector resulted in a dose-dependent NF-κB activation and TNF-α release in BLP-tolerised cells. Furthermore, BLP-tolerised cells exhibited markedly repressed NF-κB p65 phosphorylation and impaired binding of p65 to several pro-inflammatory cytokine gene promoters including TNF-α and interleukin-6 (IL-6). Overexpression of IRAK-1 restored the nuclear transactivation of p65 at both TNF-α and IL-6 promoters. These results indicate a crucial role for IRAK-1 in BLP-induced tolerance, and suggest IRAK-1 as a potential target for manipulation of the TLR-mediated inflammatory response during microbial sepsis.

  1. Are grazer-induced adaptations of bacterial abundance and morphology timedependent?

    Directory of Open Access Journals (Sweden)

    Gianluca CORNO

    2006-02-01

    Full Text Available Predation by protists is a well known force that shapes bacterial communities and can lead to filamentous forms and aggregations of large cell clusters. These classic resistance strategies were observed as a direct consequence of predation by heteroand mixotrophic flagellates (the main group of bacteria predators in water on natural assemblages of bacteria and on single plastic strains. Recently it was shown that a long time exposure (about 30 days of a bacterial strain, characterized by high degree of phenotypic plasticity, to flagellates, without direct predation, enhanced the formation of resistant forms (filaments in a continuous culture system. Target prey populations and predators were separated by a dialysis membrane. Moreover, the positive impact on bacterial growth, due to the chemical excretes released by flagellates was demonstrated for exudates of photosynthetic activity. The same positive impact may also be seen in response to exudates related to grazing. In this study, two short-term experiments (<100 hours were conducted to test for modifications in the morphology and productivity of three different bacterial strains that were induced by the presence of active predators, but without direct predation. The growth and morphological distribution of each of the selected strains was tested separately using batch cultures. Cultures were either enriched with carbon in the presence or absence of flagellate predators, or included pre-filtered exudates from flagellate activity. In a second experiment, bottles were provided with a central dialysis bag that contained active flagellates, and were inoculated with the selected bacterial strains. In this way, bacteria were exposed to the presence of predators without direct predation. The bacterial strains used in this experience were characterised by a high degree of phenotypic plasticity and exhibited different successful strategies of resistance against grazing. The flagellates selected as

  2. Lithocholic acid feeding induces segmental bile duct obstruction and destructive cholangitis in mice.

    Science.gov (United States)

    Fickert, Peter; Fuchsbichler, Andrea; Marschall, Hanns-Ulrich; Wagner, Martin; Zollner, Gernot; Krause, Robert; Zatloukal, Kurt; Jaeschke, Hartmut; Denk, Helmut; Trauner, Michael

    2006-02-01

    We determined the mechanisms of hepatobiliary injury in the lithocholic acid (LCA)-fed mouse, an increasingly used model of cholestatic liver injury. Swiss albino mice received control diet or 1% (w/w) LCA diet (for 1, 2, and 4 days), followed by assessment of liver morphology and ultrastructure, tight junctions, markers of fibrosis and key proteins of hepatobiliary function, and bile flow and composition. As expected LCA feeding led to bile infarcts, which were followed by a destructive cholangitis with activation and proliferation of periductal myofibroblasts. At the ultrastructural level, small bile ducts were frequently obstructed by crystals. Biliary-excreted fluorescence-labeled ursodeoxycholic acid accumulated in bile infarcts, whereas most infarcts did not stain with India ink injected into the common bile duct; both findings are indicative of partial biliary obstruction. Expression of the main basolateral bile acid uptake proteins (sodium-taurocholate cotransporter and organic anion-transporting polypeptide 1) was reduced, the canalicular transporters bile salt export pump and multidrug-related protein 2 were preserved, and the basolateral transporter multidrug-related protein 3 and the detoxifying enzyme sulfotransferase 2a1 were induced. Thus, we demonstrate that LCA feeding in mice leads to segmental bile duct obstruction, destructive cholangitis, periductal fibrosis, and an adaptive transporter and metabolic enzyme response. PMID:16436656

  3. Chicken Caecal Microbiome Modifications Induced by Campylobacter jejuni Colonization and by a Non-Antibiotic Feed Additive.

    Directory of Open Access Journals (Sweden)

    Alexandre Thibodeau

    Full Text Available Campylobacter jejuni is an important zoonotic foodborne pathogen causing acute gastroenteritis in humans. Chickens are often colonized at very high numbers by C. jejuni, up to 10(9 CFU per gram of caecal content, with no detrimental effects on their health. Farm control strategies are being developed to lower the C. jejuni contamination of chicken food products in an effort to reduce human campylobacteriosis incidence. It is believed that intestinal microbiome composition may affect gut colonization by such undesirable bacteria but, although the chicken microbiome is being increasingly characterized, information is lacking on the factors affecting its modulation, especially by foodborne pathogens. This study monitored the effects of C. jejuni chicken caecal colonization on the chicken microbiome in healthy chickens. It also evaluated the capacity of a feed additive to affect caecal bacterial populations and to lower C. jejuni colonization. From day-0, chickens received or not a microencapsulated feed additive and were inoculated or not with C. jejuni at 14 days of age. Fresh caecal content was harvested at 35 days of age. The caecal microbiome was characterized by real time quantitative PCR and Ion Torrent sequencing. We observed that the feed additive lowered C. jejuni caecal count by 0.7 log (p<0.05. Alpha-diversity of the caecal microbiome was not affected by C. jejuni colonization or by the feed additive. C. jejuni colonization modified the caecal beta-diversity while the feed additive did not. We observed that C. jejuni colonization was associated with an increase of Bifidobacterium and affected Clostridia and Mollicutes relative abundances. The feed additive was associated with a lower Streptococcus relative abundance. The caecal microbiome remained relatively unchanged despite high C. jejuni colonization. The feed additive was efficient in lowering C. jejuni colonization while not disturbing the caecal microbiome.

  4. Immune responses and protection induced by Brucella suis S2 bacterial ghosts in mice.

    Science.gov (United States)

    Liu, Jun; Li, Yi; Sun, Yang; Ji, Xue; Zhu, Lingwei; Guo, Xuejun; Zhou, Wei; Zhou, Bo; Liu, Shuang; Zhang, Ruian; Feng, Shuzhang

    2015-08-15

    With the purpose of generating Brucella suis bacterial ghosts and investigating the immunogenicity of bacterial ghosts as a vaccine candidate, the lysis gene E and temperature-sensitive regulator cassette were cloned into a shuttle plasmid, pBBR1MCS-2, for construction of a recombinant temperature-sensitive shuttle lysis plasmid, pBBR1MCS-E. pBBR1MCS-E was then introduced into attenuated B. suis live vaccine S2 bacteria, and the resultant transformants were used for production of B. suis ghosts (BSGs) by inducing lysis gene E expression. The BSGs were characterized by observing their morphology by transmission electron microscopy. The safety and immunogenicity of BSGs were further evaluated using a murine model, the result suggested that BSG was as safe as formalin-killed B. suis. In mice, BSG demonstrated a similar capacity of inducing pathogen-specific serum IgG antibody response, spleen CD3(+) and CD4(+) T cell responses, induce secretion of gamma interferon and interleukin-4, and protection levels against Brucella melitensis 16M challenge, as the attenuated B. suis live vaccine. These data suggesting that BSG could confer protection against Brucella infection in a mouse model of disease and may be developed as a new vaccine candidate against Brucella infection. PMID:26022514

  5. Ischemic stroke induces gut permeability and enhances bacterial translocation leading to sepsis in aged mice

    Science.gov (United States)

    Verma, Rajkumar; Venna, Venugopal R.; Liu, Fudong; Chauhan, Anjali; Koellhoffer, Edward; Patel, Anita; Ricker, Austin; Maas, Kendra; Graf, Joerg; McCullough, Louise D.

    2016-01-01

    Aging is an important risk factor for post-stroke infection, which accounts for a large proportion of stroke-associated mortality. Despite this, studies evaluating post-stroke infection rates in aged animal models are limited. In addition, few studies have assessed gut microbes as a potential source of infection following stroke. Therefore we investigated the effects of age and the role of bacterial translocation from the gut in post-stroke infection in young (8-12 weeks) and aged (18-20 months) C57Bl/6 male mice following transient middle cerebral artery occlusion (MCAO) or sham surgery. Gut permeability was examined and peripheral organs were assessed for the presence of gut-derived bacteria following stroke. Furthermore, sickness parameters and components of innate and adaptive immunity were examined. We found that while stroke induced gut permeability and bacterial translocation in both young and aged mice, only young mice were able to resolve infection. Bacterial species seeding peripheral organs also differed between young (Escherichia) and aged (Enterobacter) mice. Consequently, aged mice developed a septic response marked by persistent and exacerbated hypothermia, weight loss, and immune dysfunction compared to young mice following stroke. PMID:27115295

  6. Antibiotic-induced change of bacterial communities associated with the copepod Nitocra spinipes.

    Directory of Open Access Journals (Sweden)

    Anna Edlund

    Full Text Available Environmental pressures, such as physical factors, diet and contaminants may affect interactions between microbial symbionts and their multicellular hosts. Despite obvious relevance, effects of antimicrobial contaminants on host-symbiont relations in non-target aquatic organisms are largely unknown. We show that exposure to antibiotics had negative effects on survival and juvenile development of the copepod Nitocra spinipes and caused significant alterations in copepod-associated bacterial communities. The significant positive correlations between indices of copepod development and bacterial diversity indicate that disruption of the microflora was likely to be an important factor behind retarded juvenile development in the experimental animals. Moreover, as evidenced by ribotype distribution in the bacterial clone libraries, the exposure to antibiotics caused a shift in dominance from Betaproteobacteria to Cardinium bacteria; the latter have been shown to cause reproductive manipulations in various terrestrial arthropods. Thus, in addition to providing evidence that the antibiotic-induced perturbation of the microbial community associates with reductions in fitness-related traits of the host, this study is the first record of a copepod serving as a host for endosymbiotic Cardinium. Taken together, our results suggest that (1 antimicrobial substances and possibly other stressors can affect micobiome and symbiont-mediated interactions in copepods and other hosts, and (2 Cardinium endosymbionts may occur in other copepods and affect reproduction of their hosts.

  7. Bacterial flora of sturgeon fingerling

    International Nuclear Information System (INIS)

    The study on microbial populations is a suitable tool to understand and apply control methods to improve the sanitary level of production in fish breeding and rearing centers, ensure health of sturgeon fingerlings at the time of their release into the rivers and also in the conversation and restoration of these valuable stocks in the Caspian Sea, Iran. A laboratory research based on Austin methods (Austin, B., Austin, D.A. 1993) was conducted for bacterial study on 3 sturgeon species naming A. persicus, A. stellatus and A. nudiventris during different growth stages. Bacterial flora of Acinetobacter, Moraxella, Aeromonas, Vibrio, Edwardsiella, Staphylococcus, Proteus, Yersinia, Pseudomonas and Plesiomonas were determined. The factors which may induce changes in bacterial populations during different stages of fife are the followings: quality of water in rearing ponds, different conditions for growth stages, suitable time for colonization of bacterial flora in rearing pond, water temperature increase in fingerlings size and feeding condition. (author)

  8. The effect of the feed-to-buffer ratio on bacterial diversity and ruminal fermentation in single-flow continuous-culture fermenters.

    Science.gov (United States)

    Cantalapiedra-Hijar, G; Yáñez-Ruiz, D R; Newbold, C J; Molina-Alcaide, E

    2011-03-01

    Eight single-flow continuous-culture fermenters were used in a completely randomized block design with a 2 × 4 factorial arrangement of treatments to investigate the effects of the feed-to-buffer ratio (F/B) on ruminal fermentation, the diversity and community structure of bacteria, nutrient digestibility, and N metabolism. Four diets with forage-to-concentrate ratios of 70:30 or 30:70 with alfalfa or grass hay as forage were supplied to fermenters twice per day at 2 different F/B (23.5 and 35 g of DM/L). The dilution rate was kept constant (5.3%) among all fermenters by infusing the same volume of buffer. An increase in the total volatile fatty acid (VFA) concentration and a decrease in the average pH were observed with an increased F/B. In addition, the molar proportions of all individual VFA found in fermenters differed, depending on the F/B. A terminal restriction fragment length polymorphism analysis showed that the community structure and diversity of bacteria were highly influenced by the F/B. Both diversity and the number of peaks in the electropherograms were lower in most fermenters receiving diets at a high F/B, whereas the similarity percentage of the bacterial communities across diets was higher as the F/B increased. Moreover, the high reduction of neutral detergent fiber digestibility (15.3% ± 3.65) in fermenters with high F/B suggested a pH-related decrease in the cellulolytic bacterial community as the F/B increased. The crude protein degradation found in fermenters receiving diets with a high F/B was lower compared with that from fermenters with a low F/B. The VFA concentration and purine bases flow response patterns to diets were similar to in vivo conditions only in the case of fermenters with a low F/B. The results suggested that the community structure and diversity of bacteria, as well as the in vitro fermentation parameters, may be affected by the F/B that is used, most likely through a pH effect. In addition, several fermentation

  9. Effect of an acute necrotic bacterial gill infection and feed deprivation on the metabolic rate of Atlantic salmon Salmo salar.

    Science.gov (United States)

    Jones, M A; Powell, M D; Becker, J A; Carter, C G

    2007-10-31

    In this study, experiments were conducted to examine the effect of an acute necrotic bacterial gill infection on the metabolic rate (M(O2)) of Atlantic salmon Salmo salar. Fed and unfed Atlantic salmon smolts were exposed to a high concentration (5 x 10(12) CFU ml(-1)) of the bacteria Tenacibaculum maritimum, their routine and maximum metabolic rates (M(O2rout) and M(O2max), respectively) were measured, and relative metabolic scope determined. A significant decrease in metabolic scope was found for both fed and unfed infected groups. Fed infected fish had a mean +/- standard error of the mean (SEM) decrease of 2.21 +/- 0.97 microM O2 g(-1) h(-1), whilst unfed fish a mean +/- SEM decrease of 3.16 +/- 1.29 microM O2 g(-1) h(-1). The decrease in metabolic scope was a result of significantly increased M(O2rout) of both fed and unfed infected salmon. Fed infected fish had a mean +/- SEM increase in M(O2rout) of 1.86 +/- 0.66 microM O2 g(-1) h(-1), whilst unfed infected fish had a mean +/- SEM increase of 2.16 +/- 0.72 microM O2 g(-1) h(-1). Interestingly, all groups maintained M(O2max) regardless of infection status. Increases in M(O2rout) corresponded to a significant increase in blood plasma osmolality. A decrease in metabolic scope has implications for how individuals allocate energy; fish with smaller metabolic scope will have less energy to allocate to functions such as growth, reproduction and immune response, which may adversely affect the efficiency of fish growth. PMID:18159670

  10. Rhinovirus Infection Induces Degradation of Antimicrobial Peptides and Secondary Bacterial Infection in Chronic Obstructive Pulmonary Disease

    OpenAIRE

    Patrick Mallia; Joseph Footitt; Rosa Sotero; Annette Jepson; Marco Contoli; Maria-Belen Trujillo-Torralbo; Tatiana Kebadze; Julia Aniscenko; Gregory Oleszkiewicz; Katrina Gray; Message, Simon D.; Kazuhiro Ito; Barnes, Peter J; Adcock, Ian M.; Alberto Papi

    2012-01-01

    Rationale: Chronic obstructive pulmonary disease (COPD) exacerbations are associated with virus (mostly rhinovirus) and bacterial infections, but it is not known whether rhinovirus infections precipitate secondary bacterial infections.

  11. Ocean acidification induces changes in algal palatability and herbivore feeding behavior and performance.

    Science.gov (United States)

    Duarte, Cristian; López, Jorge; Benítez, Samanta; Manríquez, Patricio H; Navarro, Jorge M; Bonta, Cesar C; Torres, Rodrigo; Quijón, Pedro

    2016-02-01

    The effects of global stressors on a species may be mediated by the stressors' impact on coexisting taxa. For instance, herbivore-algae interactions may change due to alterations in algal nutritional quality resulting from high CO2 levels associated with ocean acidification (OA). We approached this issue by assessing the indirect effects of OA on the trophic interactions between the amphipod Orchestoidea tuberculata and the brown alga Durvillaea antarctica, two prominent species of the South-east Pacific coast. We predicted that amphipod feeding behavior and performance (growth rate) will be affected by changes in the palatability of the algae exposed to high levels (1000 ppm) of CO2. We exposed algae to current and predicted (OA) atmospheric CO2 levels and then measured their nutritive quality and amphipod preference in choice trials. We also assessed consumption rates separately in no-choice trials, and measured amphipod absorption efficiency and growth rates. Protein and organic contents of the algae decreased in acidified conditions and amphipods showed low preference for these algae. However, in the no-choice trials we recorded higher grazing rates on algae exposed to OA. Although amphipod absorption efficiency was lower on these algae, growth rates did not differ between treatments, which suggests the occurrence of compensatory feeding. Our results suggest that changes in algal nutritional value in response to OA induce changes in algal palatability and these in turn affect consumers' food preference and performance. Indirect effects of global stressors like OA can be equally or more important than the direct effects predicted in the literature. PMID:26453521

  12. EFFICACY OF TOMATO AND / OR GARLIC IN AMELIORATING CARDIAC DISORDERS INDUCED BY FEEDING RATS FRYING OIL

    International Nuclear Information System (INIS)

    Tomato (Lycopersicon esculentum) and garlic (Allium cepa) are important constituents of the human diet. Garlic and its preparations have been widely recognized as agents for prevention and treatment of cardiovascular and other metabolic diseases, atherosclerosis, hyperlipidaemia, thrombosis, hypertension and diabetes. Tomato has anti-mutagenic activities and contains lycopene (a powerful antioxidant) that appears to prevent oxidation of low density lipoprotein cholesterol (LDL-c) and reduces the risk of developing atherosclerosis and coronary heart disease. The present study was carried out to investigate the potential protective effects of tomato or garlic alone or their combination against cardiac disorders in rats fed commercial diet fortified with frying oil (15% w/w) for 30 days. Thirty male Wistar albino rats were used and were divided into five groups; group 1, control (rats fed diet containing 15% w/w fresh oil); group 2, animals fed diets fortified with frying oil; groups 3-5, rats fed as in group 2 and received tomato (500 mg/kg body weight), garlic (125 mg/kg body weight) and a combination of tomato and garlic by gavage, respectively.Total cholesterol (TC), triacylglycerols (TAG), phospholipids (PL), high density lipoprotein cholesterol (HDL-c), low density lipoprotein cholesterol (LDL-c),and very low density lipoprotein cholesterol (VLDL-c) were estimated in the serum of different animal groups. Lactic dehydrogenase (LDH), creatine phosphokinase (CPK), aspartate aminotransferase (AST) alanine aminotransferase (ALT), triiodothyronine (T3), thyroxine (T4) and thyroid stimulating hormone (TSH) were determined in the serum as well as lipid peroxidation level (TBARS) and reduced glutathione (GSH) content were assessed in cardiac tissues.The results obtained revealed that, feeding rats on frying oil induced a notable increase in lipid profile, LDL-c, VLDL-c and TBARS associated with a marked depletion in GSH. Elevation in specific heart enzymes, LDL, CPK, ALT

  13. Role of acute-phase proteins in interleukin-1-induced nonspecific resistance to bacterial infections in mice.

    OpenAIRE

    Vogels, M.T.E.; L. Cantoni; Carelli, M.; Sironi, M; Ghezzi, P; van der Meer, J. W M

    1993-01-01

    Treatment with a single low dose (80 to 800 ng) of interleukin-1 (IL-1) 24 h before a lethal bacterial challenge of granulocytopenic and normal mice enhances nonspecific resistance. Since IL-1 induces secretion of acute-phase proteins, liver proteins which possess several detoxifying effects, we investigated the role of these proteins in the IL-1-induced protection. Inhibition of liver protein synthesis with D-galactosamine (GALN) completely inhibited the IL-1-induced synthesis of acute-phase...

  14. Coronatine inhibits stomatal closure and delays hypersensitive response cell death induced by nonhost bacterial pathogens

    Directory of Open Access Journals (Sweden)

    Seonghee Lee

    2013-02-01

    Full Text Available Pseudomonas syringae is the most widespread bacterial pathogen in plants. Several strains of P. syringae produce a phytotoxin, coronatine (COR, which acts as a jasmonic acid mimic and inhibits plant defense responses and contributes to disease symptom development. In this study, we found that COR inhibits early defense responses during nonhost disease resistance. Stomatal closure induced by a nonhost pathogen, P. syringae pv. tabaci, was disrupted by COR in tomato epidermal peels. In addition, nonhost HR cell death triggered by P. syringae pv. tabaci on tomato was remarkably delayed when COR was supplemented along with P. syringae pv. tabaci inoculation. Using isochorismate synthase (ICS-silenced tomato plants and transcript profiles of genes in SA- and JA-related defense pathways, we show that COR suppresses SA-mediated defense during nonhost resistance.

  15. Self-Adjuvanting Bacterial Vectors Expressing Pre-Erythrocytic Antigens Induce Sterile Protection against Malaria

    Directory of Open Access Journals (Sweden)

    Elke eBergmann-Leitner

    2013-07-01

    Full Text Available Genetically inactivated, Gram-negative bacteria that express malaria vaccine candidates represent a promising novel self-adjuvanting vaccine approach. Antigens expressed on particulate bacterial carriers not only target directly to antigen-presenting cells but also provide a strong danger signal thus circumventing the requirement for potent extraneous adjuvants. E. coli expressing malarial antigens resulted in the induction of either Th1 or Th2 biased responses that were dependent on both antigen and sub-cellular localization. Some of these constructs induced higher quality humoral responses compared to recombinant protein and most importantly they were able to induce sterile protection against sporozoite challenge in a murine model of malaria. In light of these encouraging results, two major Plasmodium falciparum pre-erythrocytic malaria vaccine targets, the Cell-Traversal protein for Ookinetes and Sporozoites (CelTOS fused to the Maltose-binding protein in the periplasmic space and the Circumsporozoite Protein (CSP fused to the Outer membrane protein A in the outer membrane were expressed in a clinically relevant, attenuated Shigella strain (Shigella flexneri 2a. This type of live attenuated vector has previously undergone clinical investigations as a vaccine against shigellosis. Using this novel delivery platform for malaria, we find that vaccination with the whole organism represents an effective vaccination alternative that induces protective efficacy against sporozoite challenge. Shigella GeMI-Vax expressing malaria targets warrant further evaluation to determine their full potential as a dual disease, multivalent, self-adjuvanting vaccine system, against both shigellosis and malaria.

  16. Bacterial β-(1,3)-glucan prevents DSS-induced IBD by restoring the reduced population of regulatory T cells.

    Science.gov (United States)

    Lee, Kwang-Ho; Park, Min; Ji, Kon-Young; Lee, Hwa-Youn; Jang, Ji-Hun; Yoon, Il-Joo; Oh, Seung-Su; Kim, Su-Man; Jeong, Yun-Hwa; Yun, Chul-Ho; Kim, Mi-Kyoung; Lee, In-Young; Choi, Ha-Rim; Ko, Ki-sung; Kang, Hyung-Sik

    2014-10-01

    Bacterial β-(1,3)-glucan has more advantages in terms of cost, yield and efficiency than that derived from mushrooms, plants, yeasts and fungi. We have previously developed a novel and high-yield β-(1,3)-glucan produced by Agrobacterium sp. R259. This study aimed to elucidate the functional mechanism and therapeutic efficacy of bacterial β-(1,3)-glucan in dextran sulfate sodium (DSS)-induced inflammatory bowel disease (IBD).Mice were orally pretreated with bacterial β-(1,3)-glucan at daily doses of 2.5 or 5mg/kg for 2 weeks. After 6 days of DSS treatment, clinical assessment of IBD severity and expression of pro-inflammatory cytokines were evaluated. In vivo cell proliferation was examined by immunohistochemistry using Ki-67 and ER-TR7 antibodies. The frequency of regulatory T cells (Tregs) was analyzed by flow cytometry. Natural killer (NK) activity and IgA level were evaluated using NK cytotoxicity assay and ELISA.The deterioration of body weight gain, colonic architecture, disease score and histological score was recovered in DSS-induced IBD mice when pretreated with bacterial β-(1,3)-glucan. The recruitment of macrophages and the gene expression of proinflammatory cytokines, such as IL-1β, IL-6 and IL-17A/F, were markedly decreased in the colon of β-(1,3)-glucan-pretreated mice. β-(1,3)-Glucan induced the recovery of Tregs in terms of their frequency in DSS-induced IBD mice. Intriguingly, β-(1,3)-glucan reversed the functional defects of NK cells and excessive IgA production in DSS-induced IBD mice.We conclude that bacterial β-(1,3)-glucan prevented the progression of DSS-induced IBD by recovering the reduction of Tregs, functional defect of NK cells and excessive IgA production. PMID:25092569

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

    OpenAIRE

    Brandt, Stephanie M.; Schneider, David S.

    2007-01-01

    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 th...

  18. Diet-induced bacterial immunogens in the gastrointestinal tract of dairy cows: Impacts on immunity and metabolism

    Directory of Open Access Journals (Sweden)

    Zhou Jun

    2011-08-01

    Full Text Available Abstract Dairy cows are often fed high grain diets to meet the energy demand for high milk production or simply due to a lack of forages at times. As a result, ruminal acidosis, especially subacute ruminal acidosis (SARA, occurs frequently in practical dairy production. When SARA occurs, bacterial endotoxin (or lipopolysaccharide, LPS is released in the rumen and the large intestine in a large amount. Many other bacterial immunogens may also be released in the digestive tract following feeding dairy cows diets containing high proportions of grain. LPS can be translocated into the bloodstream across the epithelium of the digestive tract, especially the lower tract, due to possible alterations of permeability and injuries of the epithelial tissue. As a result, the concentration of blood LPS increases. Immune responses are subsequently caused by circulating LPS, and the systemic effects include increases in concentrations of neutrophils and the acute phase proteins such as serum amyloid-A (SAA, haptoglobin (Hp, LPS binding protein (LBP, and C-reactive protein (CRP in blood. Entry of LPS into blood can also result in metabolic alterations. Blood glucose and nonesterified fatty acid concentrations are enhanced accompanying an increase of blood LPS after increasing the amount of grain in the diet, which adversely affects feed intake of dairy cows. As the proportions of grain in the diet increase, patterns of plasma β-hydoxybutyric acid, cholesterol, and minerals (Ca, Fe, and Zn are also perturbed. The bacterial immunogens can also lead to reduced supply of nutrients for synthesis of milk components and depressed functions of the epithelial cells in the mammary gland. The immune responses and metabolic alterations caused by circulating bacterial immunogens will exert an effect on milk production. It has been demonstrated that increases in concentrations of ruminal LPS and plasma acute phase proteins (CRP, SAA, and LBP are associated with declines in

  19. Orally administered bovine lactoferrin inhibits bacterial translocation in mice fed bovine milk.

    OpenAIRE

    Teraguchi, S.; Shin, K.; Ogata, T; Kingaku, M; Kaino, A; Miyauchi, H; Fukuwatari, Y; Shimamura, S

    1995-01-01

    Feeding of bovine milk to mice induced a high incidence of bacterial translocation from the intestines to the mesenteric lymph nodes, and the bacteria involved were mainly members of the family Enterobacteriaceae. Supplementation of the milk diet with bovine lactoferrin or a pepsin-generated hydrolysate of bovine lactoferrin resulted in significant suppression of bacterial translocation. Our findings suggest that this ability of lactoferrin to inhibit bacterial translocation may be due to its...

  20. Pathogen-induced conditioning of the primary xylem vessels - a prerequisite for the formation of bacterial emboli by Pectobacterium atrosepticum.

    Science.gov (United States)

    Gorshkov, V Y; Daminova, A G; Mikshina, P V; Petrova, O E; Ageeva, M V; Salnikov, V V; Gorshkova, T A; Gogolev, Y V

    2016-07-01

    Representatives of Pectobacterium genus are some of the most harmful phytopathogens in the world. In the present study, we have elucidated novel aspects of plant-Pectobacterium atrosepticum interactions. This bacterium was recently demonstrated to form specific 'multicellular' structures - bacterial emboli in the xylem vessels of infected plants. In our work, we showed that the process of formation of these structures includes the pathogen-induced reactions of the plant. The colonisation of the plant by P. atrosepticum is coupled with the release of a pectic polysaccharide, rhamnogalacturonan I, into the vessel lumen from the plant cell wall. This polysaccharide gives rise to a gel that serves as a matrix for bacterial emboli. P. atrosepticum-caused infection involves an increase of reactive oxygen species (ROS) levels in the vessels, creating the conditions for the scission of polysaccharides and modification of plant cell wall composition. Both the release of rhamnogalacturonan I and the increase in ROS precede colonisation of the vessels by bacteria and occur only in the primary xylem vessels, the same as the subsequent formation of bacterial emboli. Since the appearance of rhamnogalacturonan I and increase in ROS levels do not hamper the bacterial cells and form a basis for the assembly of bacterial emboli, these reactions may be regarded as part of the susceptible response of the plant. Bacterial emboli thus represent the products of host-pathogen integration, since the formation of these structures requires the action of both partners. PMID:26992469

  1. A bacterial quorum-sensing precursor induces mortality in the marine coccolithophore, Emiliania huxleyi

    Directory of Open Access Journals (Sweden)

    Elizabeth L Harvey

    2016-02-01

    Full Text Available Interactions between phytoplankton and bacteria play a central role in mediating biogeochemical cycling and food web structure in the ocean. However, deciphering the chemical drivers of these interspecies interactions remains challenging. Here we report the isolation of 2-heptyl-4-quinolone (HHQ, released by Pseudoalteromonas piscicida, a marine gamma-proteobacteria previously reported to induce phytoplankton mortality through a hitherto unknown algicidal mechanism. HHQ functions as both an antibiotic and a bacterial signaling molecule in cell-cell communication in clinical infection models. Co-culture of the bloom-forming coccolithophore, Emiliania huxleyi with both live P. piscicida and cell-free filtrates caused a significant decrease in algal growth. Investigations of the P. piscicida exometabolome revealed HHQ, at nanomolar concentrations, induced mortality in three strains of E. huxleyi. Mortality of E. huxleyi in response to HHQ occurred slowly, implying static growth rather than a singular loss event (e.g. rapid cell lysis. In contrast, the marine chlorophyte, Dunaliella tertiolecta and diatom, Phaeodactylum tricornutum were unaffected by HHQ exposures. These results suggest that HHQ mediates the type of interkingdom interactions that cause shifts in phytoplankton population dynamics. These chemically mediated interactions, and other like it, ultimately influence large-scale oceanographic processes.

  2. Bacterially induced precipitation of CaCO{sub 3}: An example from studies of cyanobacterial mats. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Chafetz, H.S.

    1990-04-30

    Bacteria induce the precipitation of calcium carbonate in the laboratory and in nature by altering their chemical environment. Geologists are recognizing the possibility that bacterially induced precipitates may form significant mineral deposits, unfortunately, there are currently no sound criteria by which they can be recognized in recent sediments, or in the rock record. Cultures of aerobic and facultative bacteria from cyanobacterial mats on Andros Island, Bahamas, and Baffin Bay, Texas, induced the precipitation of calcium carbonate under controlled conditions. Crusts, the largest features formed, are composed of 5--200{mu}m diameter bundles which are, in turn, composed of numerous individual crystals. The smallest observed features are 0.1--0.4{mu}m spheres and rods which comprise some individual crystals and crystal bundles. Crystal bundles resembling rhombohedra, tetragonal disphenoids, tetragonal dipyramids, and calcite dumbbells appear to be uniquely bacterial in origin, and they have all been observed in recent sediments. Swollen rods, discs, curved dumbbells, and 50--200{mu}m optically continuous crystals resembling brushes may be uniquely bacterial in origin, however, they have not been reported by other laboratories nor observed in natural settings. Presence of any of these forms in recent sediments should be taken as strong evidence for bacterial influence. Spheres and aragonite dumbbells have also been observed in natural environments, however, they are not always bacterial in origin. Precipitation of calcium carbonate occurs preferentially on dead cyanobacteria in the presence of bacteria. Lithification of algal mats to form stromatolites may take place in the zone of decaying organic matter due to bacterial activity.

  3. Streptococcus oralis Induces Lysosomal Impairment of Macrophages via Bacterial Hydrogen Peroxide.

    Science.gov (United States)

    Okahashi, Nobuo; Nakata, Masanobu; Kuwata, Hirotaka; Kawabata, Shigetada

    2016-07-01

    Streptococcus oralis, an oral commensal, belongs to the mitis group of streptococci and occasionally causes opportunistic infections, such as bacterial endocarditis and bacteremia. Recently, we found that the hydrogen peroxide (H2O2) produced by S. oralis is sufficient to kill human monocytes and epithelial cells, implying that streptococcal H2O2 is a cytotoxin. In the present study, we investigated whether streptococcal H2O2 impacts lysosomes, organelles of the intracellular digestive system, in relation to cell death. S. oralis infection induced the death of RAW 264 macrophages in an H2O2-dependent manner, which was exemplified by the fact that exogenous H2O2 also induced cell death. Infection with either a mutant lacking spxB, which encodes pyruvate oxidase responsible for H2O2 production, or Streptococcus mutans, which does not produce H2O2, showed less cytotoxicity. Visualization of lysosomes with LysoTracker revealed lysosome deacidification after infection with S. oralis or exposure to H2O2, which was corroborated by acridine orange staining. Similarly, fluorescent labeling of lysosome-associated membrane protein-1 gradually disappeared during infection with S. oralis or exposure to H2O2 The deacidification and the following induction of cell death were inhibited by chelating iron in lysosomes. Moreover, fluorescent staining of cathepsin B indicated lysosomal destruction. However, treatment of infected cells with a specific inhibitor of cathepsin B had negligible effects on cell death; instead, it suppressed the detachment of dead cells from the culture plates. These results suggest that streptococcal H2O2 induces cell death with lysosomal destruction and then the released lysosomal cathepsins contribute to the detachment of the dead cells. PMID:27113357

  4. Blockage of protease-activated receptor 1 ameliorates heat-stress induced intestinal high permeability and bacterial translocation.

    Science.gov (United States)

    Xu, Qiu-lin; Guo, Xiao-hua; Liu, Jing-xian; Chen, Bin; Liu, Zhi-feng; Su, Lei

    2015-04-01

    Accumulated evidences indicate intestinal lesions play an important role in the pathogenesis of heatstroke. However, the underlying mechanisms by which heat stress causes intestinal barrier dysfunction and bacterial translocation remain unclear. In this study, we investigated the role of protease-activated receptor 1 (PAR1) in heat stress-induced intestinal hyper-permeability and bacterial translocation. Intestinal permeability in heat stressed mouse was evaluated by determining plasma endotoxin concentration and urinal lactulose/mannitol (L/M) ratio with gastric administration of L/M solution. Venous blood, liver, spleen and mesenteric lymph node tissues were collected for bacterial load test. Real time PCR was used to determine ileum PAR1 mRNA expression. In vitro study, permeability was assessed by determining trans-epithelial electrical resistance (TEER) in human intestinal Caco-2 cell line. RWJ-58259, a selective antagonist of PAR1, was used both in vivo and in vitro studies. The results showed that heat stress could increase ileum PAR1 mRNA level, urinal L/M ratio, plasma endotoxin concentration and bacterial load in the blood, spleen and mesenteric lymph nodes. Blocking PAR1 with RWJ-58259 (10 mg/kg) pretreatment could significantly reduce heat stress-induced above changes, but have no role to PAR1 mRNA level. In Caco-2 cells, heat stress-induced high permeability could also be reduced by RWJ-58259 (5-20 µmol/L). In summary, our results demonstrated that PAR1 signaling pathway may play an important role in the heat stress-induced elevation of intestinal permeability, bacterial translocation and the occurrence of endotoxemia. PMID:25492552

  5. Role of granulocyte colony-stimulating factor in paclitaxel-induced intestinal barrier breakdown and bacterial translocation in rats

    Institute of Scientific and Technical Information of China (English)

    ZHANG Chi; XU Yang-guang; DUAN Xue-ning; LIU Yin-hua; ZHAO Jian-xin; XU Ling; YE Jing-ming

    2011-01-01

    Background Chemotherapy causes breakdown of the intestinal barrier, which may lead to bacterial translocation. Paclitaxel, an anti-tubulin agent, has many side effects; however, its effect on the intestinal barrier is unknown. Previous studies show that granulocyte colony-stimulating factor (G-CSF) plays an important role in modulating intestinal barrier function, but these studies are not conclusive. Here, we investigated the effects of paclitaxel on the intestinal barrier, and whether G-CSF could prevent paclitaxel-induced bacterial translocation.Methods Twenty-four male Sprague-Dawley rats were divided into three groups: control group, paclitaxel group and paclitaxel + G-CSF group. Intestinal permeability was measured by the urinary excretion rates of lactulose and mannitol administered by gavage. The mesenteric lymph nodes, spleen and liver were aseptically harvested for bacterial culture. Endotoxin levels and white blood cell (WBC) counts were measured and bacterial quantification performed using relative real-time PCR. Jejunum samples were also obtained for histological observation. Intestinal apoptosis was evaluated using a fragmented DNA assay and terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate (dUTP)-biotin nick end-labeling staining. One-way analysis of variance and Fisher's exact test were used to compare differences between groups.Results Paclitaxel induced apoptosis in 12.5% of jejunum villus cells, which was reduced to 3.8% by G-CSF treatment. Apoptosis in the control group was 0.6%. Paclitaxel treatment also resulted in villus atrophy, increased intestinal permeability and a reduction in the WBC count. G-CSF treatment resulted in increased villus height and returned WBC counts to normal levels. No bacterial translocation was detected in the control group, whereas 6/8,8/8, and 8/8 rats in the paclitaxel group were culture-positive in the liver, spleen and mesenteric lymph nodes, respectively. Bacterial translocation was

  6. Bacterial Colonization and the Expression of Inducible Nitric Oxide Synthase in Murine Wounds

    Science.gov (United States)

    Mahoney, Eric; Reichner, Jonathan; Robinson Bostom, Leslie; Mastrofrancesco, Balduino; Henry, William; Albina, Jorge

    2002-01-01

    The expression of inducible nitric oxide synthase (iNOS) in two different murine wound models was investigated. Animals were subjected to either full-thickness linear skin incision with subcutaneous implantation of sterile polyvinyl alcohol sponges, or to 1.5 × 1.5-cm dorsal skin excision. Reverse transcriptase-polymerase chain reaction detected iNOS mRNA in all cell samples retrieved from the sponges. Immunoblotting of lysates of inflammatory cells harvested from the sponges failed to detect iNOS protein, and immunohistochemistry of the incisional wound was mildly positive. Inflammatory cells of excisional wounds stained strongly positive for iNOS. Cutaneous wounds were found to be colonized with Staphylococcus aureus. The detection of iNOS in cells from sponges inoculated in vivo with heat-killed bacteria and the reduction of immunohistochemical signal for iNOS in excisional wounds of animals treated with antibiotics support a role of bacteria in the induction of iNOS in wounds. The expression of iNOS in excisional wounds requires interferon-γ and functional lymphocytes because interferon-γ knockout and SCID-Beige mice exhibited attenuated iNOS staining in excisional wounds. The expression of iNOS in the inflammatory cells of murine wounds is a response to bacterial colonization and not part of the normal repair process elicited by sterile tissue injury. PMID:12466130

  7. A comparison of multivariate analysis techniques and variable selection strategies in a laser-induced breakdown spectroscopy bacterial classification

    International Nuclear Information System (INIS)

    Laser-induced breakdown spectroscopy has been used to obtain spectral fingerprints from live bacterial specimens from thirteen distinct taxonomic bacterial classes representative of five bacterial genera. By taking sums, ratios, and complex ratios of measured atomic emission line intensities three unique sets of independent variables (models) were constructed to determine which choice of independent variables provided optimal genus-level classification of unknown specimens utilizing a discriminant function analysis. A model composed of 80 independent variables constructed from simple and complex ratios of the measured emission line intensities was found to provide the greatest sensitivity and specificity. This model was then used in a partial least squares discriminant analysis to compare the performance of this multivariate technique with a discriminant function analysis. The partial least squares discriminant analysis possessed a higher true positive rate, possessed a higher false positive rate, and was more effective at distinguishing between highly similar spectra from closely related bacterial genera. This suggests it may be the preferred multivariate technique in future species-level or strain-level classifications. - Highlights: • Laser-induced breakdown spectroscopy was used to classify bacteria by genus. • We examine three different independent variable down selection models. • A PLS-DA returned higher rates of true positives than a DFA. • A PLS-DA returned higher rates of false positives than a DFA. • A PLS-DA was better able to discriminate similar spectra compared to DFA

  8. Yeast cell wall extract induces disease resistance against bacterial and fungal pathogens in Arabidopsis thaliana and Brassica crop.

    Science.gov (United States)

    Narusaka, Mari; Minami, Taichi; Iwabuchi, Chikako; Hamasaki, Takashi; Takasaki, Satoko; Kawamura, Kimito; Narusaka, Yoshihiro

    2015-01-01

    Housaku Monogatari (HM) is a plant activator prepared from a yeast cell wall extract. We examined the efficacy of HM application and observed that HM treatment increased the resistance of Arabidopsis thaliana and Brassica rapa leaves to bacterial and fungal infections. HM reduced the severity of bacterial leaf spot and anthracnose on A. thaliana and Brassica crop leaves with protective effects. In addition, gene expression analysis of A. thaliana plants after treatment with HM indicated increased expression of several plant defense-related genes. HM treatment appears to induce early activation of jasmonate/ethylene and late activation of salicylic acid (SA) pathways. Analysis using signaling mutants revealed that HM required SA accumulation and SA signaling to facilitate resistance to the bacterial pathogen Pseudomonas syringae pv. maculicola and the fungal pathogen Colletotrichum higginsianum. In addition, HM-induced resistance conferred chitin-independent disease resistance to bacterial pathogens in A. thaliana. These results suggest that HM contains multiple microbe-associated molecular patterns that activate defense responses in plants. These findings suggest that the application of HM is a useful tool that may facilitate new disease control methods. PMID:25565273

  9. Yeast cell wall extract induces disease resistance against bacterial and fungal pathogens in Arabidopsis thaliana and Brassica crop.

    Directory of Open Access Journals (Sweden)

    Mari Narusaka

    Full Text Available Housaku Monogatari (HM is a plant activator prepared from a yeast cell wall extract. We examined the efficacy of HM application and observed that HM treatment increased the resistance of Arabidopsis thaliana and Brassica rapa leaves to bacterial and fungal infections. HM reduced the severity of bacterial leaf spot and anthracnose on A. thaliana and Brassica crop leaves with protective effects. In addition, gene expression analysis of A. thaliana plants after treatment with HM indicated increased expression of several plant defense-related genes. HM treatment appears to induce early activation of jasmonate/ethylene and late activation of salicylic acid (SA pathways. Analysis using signaling mutants revealed that HM required SA accumulation and SA signaling to facilitate resistance to the bacterial pathogen Pseudomonas syringae pv. maculicola and the fungal pathogen Colletotrichum higginsianum. In addition, HM-induced resistance conferred chitin-independent disease resistance to bacterial pathogens in A. thaliana. These results suggest that HM contains multiple microbe-associated molecular patterns that activate defense responses in plants. These findings suggest that the application of HM is a useful tool that may facilitate new disease control methods.

  10. Induced mutation for disease resistance in rice with special reference to blast, bacterial blight and tungro

    International Nuclear Information System (INIS)

    Rice varieties Ratna, Pusa 2-21, Vijaya and Pankaj have been treated with gamma rays, EMS or sodium azide to improve their resistance against blast, bacterial leaf blight or tungro virus. For blast and tungro, mutants with improved resistance were selected. Variation in reaction to bacterial leaf blight has been used in crossbreeding to accumulate genes for resistance. (author)

  11. Optimizing an Aversion Feeding Therapy Protocol for a Child with Food Protein-Induced Enterocolitis Syndrome (FPIES)

    OpenAIRE

    Mattingly, Rhonda; Mukkada, Vincent; Smith, Alan; Pitts, Teresa

    2015-01-01

    This case study examines the difficulties of treating food aversion in a 9-month old child with a diagnosis of Food Protein-Induced Enterocolitis Syndrome (FPIES). Given the need to first identify a set of “safe foods” with which to work, the twin goals of doing food challenges and minimizing aversion are initially not complimentary, and require an approach outside the standard of care. The chosen plan encouraged flexibility and a positive relationship with feeding-related items, while only i...

  12. Gut Microbiota Dysbiosis Is Associated with Inflammation and Bacterial Translocation in Mice with CCl4-Induced Fibrosis

    OpenAIRE

    Gómez-Hurtado, Isabel; Santacruz, Arlette; Peiró, Gloria; Zapater, Pedro; Gutiérrez, Ana; Pérez-Mateo, Miguel; Sanz, Yolanda; Francés, Rubén

    2011-01-01

    Background Gut is the major source of endogenous bacteria causing infections in advanced cirrhosis. Intestinal barrier dysfunction has been described in cirrhosis and account for an increased bacterial translocation rate. Hypothesis and Aims We hypothesize that microbiota composition may be affected and change along with the induction of experimental cirrhosis, affecting the inflammatory response. Animals and Methods Progressive liver damage was induced in Balb/c mice by weight-controlled ora...

  13. Change your diet or die: predator-induced shifts in insectivorous lizard feeding ecology.

    Science.gov (United States)

    Hawlena, Dror; Pérez-Mellado, Valentín

    2009-08-01

    Animal feeding ecology and diet are influenced by the fear of predation. While the mechanistic bases for such changes are well understood, technical difficulties often prevent testing how these mechanisms interact to affect a mesopredator's diet in natural environments. Here, we compared the insectivorous lizard Acanthodactylus beershebensis' feeding ecology and diet between high- and low-risk environments, using focal observations, intensive trapping effort and fecal pellet analysis. To create spatial variation in predation risk, we planted "artificial trees" in a scrubland habitat that lacks natural perches, allowing avian predators to hunt for lizards in patches that were previously unavailable to them. Lizards in elevated-risk environments became less mobile but did not change their microhabitat use or temporal activity. These lizards changed their diet, consuming smaller prey and less plant material. We suggest that diet shifts were mainly because lizards from risky environments consumed prey items that required shorter handling time. PMID:19466458

  14. Deletion of GPR40 fatty acid receptor gene in mice blocks mercaptoacetate-induced feeding.

    Science.gov (United States)

    Li, Ai-Jun; Wiater, Michael F; Wang, Qing; Wank, Stephen; Ritter, Sue

    2016-05-15

    Both increased and decreased fatty acid (FA) availability contribute to control of food intake. For example, it is well documented that intestinal FA reduces feeding by triggering enterondocrine secretion of satietogenic peptides, such as cholecystokinin (CCK) and glucagon-like peptide-1 (GLP-1). In contrast, mechanisms by which decreased FA availability increase feeding are not well understood. Over the past three decades substantial research related to FA availability and increased feeding has involved use of the orexigenic compound mercaptoacetate (MA). Because MA reportedly inhibits FA oxidation, it has been assumed that reduced FA oxidation accounts for the orexigenic action of MA. Recently, however, we demonstrated that MA antagonizes G protein-coupled receptor 40 (GPR40), a membrane receptor for long and medium chain FA. We also demonstrated that, by antagonizing GPR40, MA inhibits GLP-1 secretion and attenuates vagal afferent activation by FA. Because both vagal afferent activation and GLP-1 inhibit food intake, we postulated that inhibition of GPR40 by MA might underlie the orexigenic action of MA. We tested this hypothesis using male and female GPR40 knockout (KO) and wild-type (WT) mice. Using several testing protocols, we found that MA increased feeding in WT, but not GPR40 KO mice, and that GPR40 KO mice gained more weight than WT on a high-fat diet. Metabolic monitoring after MA or saline injection in the absence of food did not reveal significant differences in respiratory quotient or energy expenditure between treatment groups or genotypes. These results support the hypothesis that MA stimulates food intake by blocking FA effects on GPR40. PMID:26984894

  15. Lithocholic Acid Feeding Induces Segmental Bile Duct Obstruction and Destructive Cholangitis in Mice

    OpenAIRE

    Fickert, Peter; Fuchsbichler, Andrea; Marschall, Hanns-Ulrich; Wagner, Martin; Zollner, Gernot.; Krause, Robert; Zatloukal, Kurt; Jaeschke, Hartmut; Denk, Helmut; Trauner, Michael

    2006-01-01

    We determined the mechanisms of hepatobiliary injury in the lithocholic acid (LCA)-fed mouse, an increasingly used model of cholestatic liver injury. Swiss albino mice received control diet or 1% (w/w) LCA diet (for 1, 2, and 4 days), followed by assessment of liver morphology and ultrastructure, tight junctions, markers of fibrosis and key proteins of hepatobiliary function, and bile flow and composition. As expected LCA feeding led to bile infarcts, which were followed by a destructive chol...

  16. Feeding Induced by Cannabinoids Is Mediated Independently of the Melanocortin System

    OpenAIRE

    Sinnayah, Puspha; Jobst, Erin E.; Rathner, Joseph A.; Caldera-Siu, Angela D.; Tonelli-Lemos, Luciana; Eusterbrock, Aaron J.; Enriori, Pablo J.; Pothos, Emmanuel N.; Grove, Kevin L.; Cowley, Michael A.

    2008-01-01

    Background Cannabinoids, the active components of marijuana, stimulate appetite, and cannabinoid receptor-1 (CB1-R) antagonists suppress appetite and promote weight loss. Little is known about how CB1-R antagonists affect the central neurocircuitry, specifically the melanocortin system that regulates energy balance. Methodology/Principal Findings Here, we show that peripherally administered CB1-R antagonist (AM251) or agonist equally suppressed or stimulated feeding respectively in Ay , which...

  17. Ultrastructural and histological changes induced by ivermectin in the ovary of Argas persicus after feeding

    OpenAIRE

    Hamdy, H.Swelim; Aleya, S.Marzouk;Ashraf,A.M.Montasser

    2003-01-01

    The ovarian wall of A.persicus consists of primary oocytes of three developmental stages namely , young , previtellogenic and vitellogenic in addition to interstitial cells . After feeding and mating , the three stages and interstitial cells , particularly funicle cells that carry oocytes , markedly increased in size and their cytoplasmic organelles exhibit notable changes correlated with yolk and egg shell formation . The present study examined the hitological and ultrastructural aspects dur...

  18. Giardia duodenalis induces paracellular bacterial translocation and causes postinfectious visceral hypersensitivity.

    Science.gov (United States)

    Halliez, Marie C M; Motta, Jean-Paul; Feener, Troy D; Guérin, Gaetan; LeGoff, Laetitia; François, Arnaud; Colasse, Elodie; Favennec, Loic; Gargala, Gilles; Lapointe, Tamia K; Altier, Christophe; Buret, André G

    2016-04-15

    Irritable bowel syndrome (IBS) is the most frequent functional gastrointestinal disorder. It is characterized by abdominal hypersensitivity, leading to discomfort and pain, as well as altered bowel habits. While it is common for IBS to develop following the resolution of infectious gastroenteritis [then termed postinfectious IBS (PI-IBS)], the mechanisms remain incompletely understood. Giardia duodenalis is a cosmopolitan water-borne enteropathogen that causes intestinal malabsorption, diarrhea, and postinfectious complications. Cause-and-effect studies using a human enteropathogen to help investigate the mechanisms of PI-IBS are sorely lacking. In an attempt to establish causality between giardiasis and postinfectious visceral hypersensitivity, this study describes a new model of PI-IBS in neonatal rats infected with G. duodenalis At 50 days postinfection with G. duodenalis (assemblage A or B), long after the parasite was cleared, rats developed visceral hypersensitivity to luminal balloon distension in the jejunum and rectum, activation of the nociceptive signaling pathway (increased c-fos expression), histological modifications (villus atrophy and crypt hyperplasia), and proliferation of mucosal intraepithelial lymphocytes and mast cells in the jejunum, but not in the rectum. G. duodenalis infection also disrupted the intestinal barrier, in vivo and in vitro, which in turn promoted the translocation of commensal bacteria. Giardia-induced bacterial paracellular translocation in vitro correlated with degradation of the tight junction proteins occludin and claudin-4. The extensive observations associated with gut hypersensitivity described here demonstrate that, indeed, in this new model of postgiardiasis IBS, alterations to the gut mucosa and c-fos are consistent with those associated with PI-IBS and, hence, offer avenues for new mechanistic research in the field. PMID:26744469

  19. Practical value of induced mutants of rice resistant to bacterial leaf blight

    International Nuclear Information System (INIS)

    The thermal neutron induced mutants of rice resistance to bacterial leaf blight (BLB), designated M41 and M57, in which resistance is conditioned by a single gene and polygenes, respectively, were evaluated for their practical value for breeding rice varieties resistant to BLB. Three experiments were carried out. (1) The nature of the resistance of the mutants was examined from various aspects. The two mutants were resistant to the Japanese and Philippines BLB differential races. The resistance of M41 was found to vary to some extent with the planting year, the amount of nitrogen fertilizer applied and the plant age compared with M57, although the resistance level of M41 was higher than that of M57. (2) BLB resistant F3 or F4 lines derived from crosses of the mutants x original variety Harebare were analysed for some agronomic traits. One of the M57 x Harebare lines that had a good shape and a higher yielding capacity was not released as a commercial variety because of the poor taste of the rice. All the M41 x Harebare lines carried some negative traits inherited from M41, e.g. a lower yielding capacity, an inadequate mature husk colour, etc. (3) The F3 lines from crosses of the leading Japanese varieties Koshihikari and Akitakomachi x M41 were also analysed for their resistance and some other agronomic traits. Some of the resistant lines were found to exhibit favourable traits, e.g. good taste of the rice, which may lead to the development of new commercial varieties in the near future. (author). 14 refs, 9 figs 2 tabs

  20. Regeneration of Phosphorus and Nitrogen by Four Species of Heterotrophic Nanoflagellates Feeding on Three Nutritional States of a Single Bacterial Strain

    OpenAIRE

    Eccleston-Parry, J. D.; Leadbeater, B.

    1995-01-01

    Three physiological states of a single bacterial strain, namely, balanced, phosphorus-rich, and nitrogen-rich bacteria, were obtained by culturing a bacterial strain in chemostats under three different nutrient regimens. Each was shown to be distinctly different in elemental composition with respect to C/N/P ratio. These bacteria were fed to four species of heterotrophic nanoflagellates in batch culture grazing experiments, and the percent regeneration efficiencies of bacterium-bound nitrogen...

  1. Dietary feeding of silibinin prevents early biomarkers of UVB radiation-induced carcinogenesis in SKH-1 hairless mouse epidermis.

    Science.gov (United States)

    Gu, Mallikarjuna; Dhanalakshmi, Sivanandhan; Singh, Rana P; Agarwal, Rajesh

    2005-05-01

    Solar radiation is the causal etiologic factor in the development of nonmelanoma skin cancer (NMSC). Depletion of the stratospheric ozone layer leads to an increase in ambient UV radiation loads, which are expected to further raise skin cancer incidence in many temperate parts of the world, including the United States, suggesting that skin cancer chemopreventive approaches via biomarker efficacy studies or vice versa are highly warranted. Based on our recent study reporting strong efficacy of silibinin against photocarcinogenesis, we assessed here the protective effects of its dietary feeding on UVB-induced biomarkers involved in NMSC providing a mechanistic rationale for an early-on silibinin efficacy in skin cancer prevention. Dietary feeding of silibinin at 1% dose (w/w) to SKH-1 hairless mice for 2 weeks before a single UVB irradiation at 180 mJ/cm(2) dose resulted in a strong and significant (P skin epidermis by (a) either preventing DNA damage or enhancing repair, (b) reducing UVB-induced hyperproliferative response, and (c) inhibiting UVB-caused apoptosis and sunburn cell formation, possibly via silibinin-caused up-regulation of p53 and p21/cip1 as major UVB-damage control sensors. PMID:15894701

  2. Are grazer-induced adaptations of bacterial abundance and morphology time-dipendent?

    OpenAIRE

    Corno, Gianluca

    2006-01-01

    Predation by protists is a well known force that shapes bacterial communities and can lead to filamentous forms and aggregations of large cell clusters. These classic resistance strategies were observed as a direct consequence of predation by heteroand mixotrophic flagellates (the main group of bacteria predators in water) on natural assemblages of bacteria and on single plastic strains. Recently it was shown that a long time exposure (about 30 days) of a bacterial strain, characterized by hi...

  3. Are grazer-induced adaptations of bacterial abundance and morphology timedependent?

    OpenAIRE

    Corno, Gianluca

    2006-01-01

    Predation by protists is a well known force that shapes bacterial communities and can lead to filamentous forms and aggregations of large cell clusters. These classic resistance strategies were observed as a direct consequence of predation by heteroand mixotrophic flagellates (the main group of bacteria predators in water) on natural assemblages of bacteria and on single plastic strains. Recently it was shown that a long time exposure (about 30 days) of a bacterial strain, characterized by hi...

  4. Melatonin reduces bacterial translocation and apoptosis in trinitrobenzene sulphonic acid-induced colitis of rats

    OpenAIRE

    Alper Akcan, Can Kucuk, Erdogan Sozuer, Duygu Esel, Hizir Akyildiz, Hulya Akgun, Sabahattin Muhtaroglu, Yucel Aritas

    2008-01-01

    AIM: To investigate the effects of exogenous melatonin on bacterial translocation and apoptosis in a rat ulcerative colitis model.METHODS: Rats were randomly assigned to three groups: groupI: control, group II: experimental colitis, group III: colitis plus melatonin treatment. On d 11 after colitis, plasma tumor necrosis factor-α, portal blood endotoxin levels, colon tissue myeloperoxidase and caspase-3 activity were measured. Bacterial translocation was quantified by blood, lymph node, liver...

  5. Tyrosine-phosphorylated caveolin-1 blocks bacterial uptake by inducing Vav2-RhoA-mediated cytoskeletal rearrangements.

    Directory of Open Access Journals (Sweden)

    Jan Peter Boettcher

    Full Text Available Certain bacterial adhesins appear to promote a pathogen's extracellular lifestyle rather than its entry into host cells. However, little is known about the stimuli elicited upon such pathogen host-cell interactions. Here, we report that type IV pili (Tfp-producing Neisseria gonorrhoeae (P(+GC induces an immediate recruitment of caveolin-1 (Cav1 in the host cell, which subsequently prevents bacterial internalization by triggering cytoskeletal rearrangements via downstream phosphotyrosine signaling. A broad and unbiased analysis of potential interaction partners for tyrosine-phosphorylated Cav1 revealed a direct interaction with the Rho-family guanine nucleotide exchange factor Vav2. Both Vav2 and its substrate, the small GTPase RhoA, were found to play a direct role in the Cav1-mediated prevention of bacterial uptake. Our findings, which have been extended to enteropathogenic Escherichia coli, highlight how Tfp-producing bacteria avoid host cell uptake. Further, our data establish a mechanistic link between Cav1 phosphorylation and pathogen-induced cytoskeleton reorganization and advance our understanding of caveolin function.

  6. Effects of opioid antagonists naloxone and naltrexone on neuropeptide Y-induced feeding and brown fat thermogenesis in the rat. Neural site of action.

    OpenAIRE

    Kotz, C.M.; Grace, M.K.; Briggs, J.; Levine, A S; Billington, C.J.

    1995-01-01

    Neuropeptide Y administered intracerebroventricularly and into the paraventricular nucleus of the hypothalamus stimulates feeding and decreases brown adipose tissue thermogenesis. Although specific neuropeptide Y antagonists are not yet available, previous studies had shown that the opioid antagonist naloxone blocked neuropeptide Y-induced feeding when both drugs were injected intracerebroventricularly. We wanted to find out if naloxone injected into specific brain sites would block neuropept...

  7. New evidence for hybrid acrylic/TiO2 films inducing bacterial inactivation under low intensity simulated sunlight.

    Science.gov (United States)

    Bonnefond, Audrey; González, Edurne; Asua, Jose María; Leiza, Jose Ramon; Kiwi, John; Pulgarin, Cesar; Rtimi, Sami

    2015-11-01

    This study addresses the preparation and characterization of hybrid films prepared from Titanium dioxide (TiO2) Pickering stabilized acrylic polymeric dispersion as well as their bacterial inactivation efficiency under sunlight irradiation. Complete bacterial inactivation under low intensity simulated solar light irradiation (55 mW/cm(2)) was observed within 240 min for the films containing 10 weight based on monomers (wbm) % of TiO2, whereas 360 min were needed for the films containing 20 wbm% of TiO2. The hybrid films showed repetitive Escherichia coli (E. coli) inactivation under light irradiation. TiO2 released from the films surfaces was measured by inductively coupled plasma mass spectrometry (IPC-MS), obtaining values of ∼ 0.5 and 1 ppb/cm(2) for the films containing 10 wbm% and 20 wbm% of TiO2, respectively, far below the allowed cytotoxicity level for TiO2 (200 ppb). Transmission electron microscopy (TEM) of the hybrid films showed that TiO2 nanoparticles (NPs) were located at the polymer particle's surface forming a continuous inorganic network inside the film matrix. Atomic force microscopy (AFM) images showed differences in the TiO2 dispersion between the air-film and film-substrate interfaces. Films containing 10 wbm% of TiO2 had higher roughness (Rg) at both interfaces than the one containing 20 wbm% of TiO2 inducing an increase in the bacterial adhesion as well as the bacterial inactivation kinetics. The highly oxidative OH-radicals participating in the bacterial inactivation were determined by fluorescence. PMID:26222605

  8. Antagonistic rhizobacteria and jasmonic acid induce resistance against tomato bacterial spot

    Directory of Open Access Journals (Sweden)

    Hélvio Gledson Maciel Ferraz

    2015-12-01

    Full Text Available AbstractTomato bacterial spot on tomato may be caused by four species of Xanthomonas and among them X. gardneri(Xg is the most destructive one, especially in areas irrigated using a center pivot system in Minas Gerais state and the midwest region of Brazil. Due to the ineffectiveness of chemical control and the lack of cultivars with high levels of genetic resistance, this study investigated the potential of three antagonists (Streptomyces setonii (UFV618, Bacillus cereus (UFV592 and Serratia marcescens (UFV252, and the hormone jasmonic acid (JA as a positive control, to reduce bacterial spot symptoms and to potentiate defense enzymes in the leaves of tomato plants infected by Xg. Tomato seeds were microbiolized with each antagonist, and the soil was drenched with these bacteria. The plants were sprayed with JA 48 h before Xginoculation. The final average severity on the tomato plants was reduced by 29.44, 59.26 and 61.33% in the UFV592, UFV618 and JA treatments, respectively. The UFV618 antagonist was as effective as JA in reducing bacterial spot symptoms on tomatoes, which can be explained by the greater activities of defense enzymes that are commonly involved in host resistance against bacterial diseases. These results suggest that JA and the UFV618 antagonist can be used in the integrated management of bacterial spot on tomatoes.

  9. Changes in soil bacterial communities induced by the invasive plant Pennisetum setaceum in a semiarid environment

    Science.gov (United States)

    Rodriguez-Caballero, Gema; Caravaca, Fuensanta; del Mar Alguacil, María; Fernández-López, Manuel; José Fernández-González, Antonio; García-Orenes, Fuensanta; Roldán, Antonio

    2016-04-01

    Invasive alien species are considered as a global threat being among the main causes of biodiversity loss. Plant invasions have been extensively studied from different disciplines with the purpose of identifying predictor traits of invasiveness and finding solutions. However, less is known about the implication of the rhizosphere microbiota in these processes, even when it is well known the importance of the interaction between plant rhizosphere and microbial communities. The objective of this study was to determine whether native and invasive plants support different bacterial communities in their rhizospheres and whether there are bacterial indicator species that might be contributing to the invasion process of these ecosystems. We carried out a study in five independent locations under Mediterranean semiarid conditions, where the native Hyparrhenia hirta is being displaced by Pennisetum setaceum, an aggressive invasive Poaceae and soil bacterial communities were amplified and 454-pyrosequenced. Changes in the composition and structure of the bacterial communities, owing to the invasive status of the plant, were detected when the richness and alpha-diversity estimators were calculated as well as when we analyzed the PCoA axes scores. The Indicator Species Analysis results showed a higher number of indicators for invaded communities at all studied taxonomic levels. In conclusion, the effect of the invasiveness and its interaction with the soil location has promoted shifts in the rhizosphere bacterial communities which might be facilitating the invader success in these ecosystems.

  10. Age, introduction of solid feed and weaning are more important determinants of gut bacterial succession in piglets than breed and nursing mother as revealed by a reciprocal cross-fostering model.

    Science.gov (United States)

    Bian, Gaorui; Ma, Shouqing; Zhu, Zhigang; Su, Yong; Zoetendal, Erwin G; Mackie, Roderick; Liu, Junhua; Mu, Chunlong; Huang, Ruihua; Smidt, Hauke; Zhu, Weiyun

    2016-05-01

    A reciprocal cross-fostering model with an obese typical Chinese piglet breed and a lean Western breed was used to identify genetic and maternal effects on the acquisition and development gut bacteria from birth until after weaning. Pyrosequencing of 16S rRNA genes results revealed an age- and diet-dependent bacterial succession process in piglets. During the first 3 days after birth, the bacterial community was relatively simple and dominated by Firmicutes with 79% and 65% relative abundance for Meishan and Yorkshire piglets, respectively. During the suckling period until day 14, the piglet breed and the nursing mother lead to increasing differentiation of the fecal bacterial community, with specific bacteria taxa associated with breed, and others with the nursing sow most likely due to its milk composition. Although the effect of nursing mother and the breed were evident through the suckling period, the introduction of solid feed and subsequent weaning were the major events occurring that dominated succession of the gut microbiota in the early life of piglets. This piglet cross-fostering model is a useful tool for studying the effects of diet, host genetics and the environment on the development and acquisition of the gut microbiota and over longer studies the subsequent impact on growth, health and performance of pigs. PMID:26940746

  11. Adaptive immunity alters distinct host feeding pathways during nematode induced inflammation, a novel mechanism in parasite expulsion.

    Directory of Open Access Journals (Sweden)

    John J Worthington

    2013-01-01

    Full Text Available Gastrointestinal infection is often associated with hypophagia and weight loss; however, the precise mechanisms governing these responses remain poorly defined. Furthermore, the possibility that alterations in feeding during infection may be beneficial to the host requires further study. We used the nematode Trichinella spiralis, which transiently inhabits the small intestine before migrating to skeletal muscle, as a biphasic model of infection to determine the cellular and molecular pathways controlling feeding during enteric and peripheral inflammation. Through the infection of genetically modified mice lacking cholecystokinin, Tumor necrosis factor α receptors and T and B-cells, we observed a biphasic hypophagic response to infection resulting from two separate immune-driven mechanisms. The enteroendocrine I-cell derived hormone cholecystokinin is an essential mediator of initial hypophagia and is induced by CD4+ T-cells during enteritis. In contrast, the second hypophagic response is extra-intestinal and due to the anorectic effects of TNFα during peripheral infection of the muscle. Moreover, via maintaining naive levels of the adipose secreted hormone leptin throughout infection we demonstrate a novel feedback loop in the immunoendocrine axis. Immune driven I-cell hyperplasia and resultant weight loss leads to a reduction in the inflammatory adipokine leptin, which in turn heightens protective immunity during infection. These results characterize specific immune mediated mechanisms which reduce feeding during intestinal or peripheral inflammation. Importantly, the molecular mediators of each phase are entirely separate. The data also introduce the first evidence that I-cell hyperplasia is an adaptively driven immune response that directly impinges on the outcome to infection.

  12. Modeling long term Enhanced in situ Biodenitrification and induced heterogeneity in column experiments under different feeding strategies

    Science.gov (United States)

    Rodríguez-Escales, Paula; Folch, Albert; van Breukelen, Boris M.; Vidal-Gavilan, Georgina; Sanchez-Vila, Xavier

    2016-07-01

    Enhanced In situ Biodenitrification (EIB) is a capable technology for nitrate removal in subsurface water resources. Optimizing the performance of EIB implies devising an appropriate feeding strategy involving two design parameters: carbon injection frequency and C:N ratio of the organic substrate nitrate mixture. Here we model data on the spatial and temporal evolution of nitrate (up to 1.2 mM), organic carbon (ethanol), and biomass measured during a 342 day-long laboratory column experiment (published in Vidal-Gavilan et al., 2014). Effective porosity was 3% lower and dispersivity had a sevenfold increase at the end of the experiment as compared to those at the beginning. These changes in transport parameters were attributed to the development of a biofilm. A reactive transport model explored the EIB performance in response to daily and weekly feeding strategies. The latter resulted in significant temporal variation in nitrate and ethanol concentrations at the outlet of the column. On the contrary, a daily feeding strategy resulted in quite stable and low concentrations at the outlet and complete denitrification. At intermediate times (six months of experiment), it was possible to reduce the carbon load and consequently the C:N ratio (from 2.5 to 1), partly because biomass decay acted as endogenous carbon to respiration, keeping the denitrification rates, and partly due to the induced dispersivity caused by the well-developed biofilm, resulting in enhancement of mixing between the ethanol and nitrate and the corresponding improvement of denitrification rates. The inclusion of a dual-domain model improved the fit at the last days of the experiment as well as in the tracer test performed at day 342, demonstrating a potential transition to anomalous transport that may be caused by the development of biofilm. This modeling work is a step forward to devising optimal injection conditions and substrate rates to enhance EIB performance by minimizing the overall supply of

  13. Identification of Genes Induced in Lolium multiflorum by Bacterial Wilt Infection

    DEFF Research Database (Denmark)

    Wichmann, Fabienne; Asp, Torben; Widmer, Franco; Kölliker, Roland

    Xanthomonas translucens pv. graminis(Xtg) causes bacterial wilt in many forage grasses including Italian ryegrass (Lolium multiflorum Lam), seriously reducing yield and quality. Breeding for resistance is currently the only practicable means of disease control. Molecular markers closely linked to...... resistance genes or QTL could complement and support phenotypic selection. We used comparative gene expression analysis of a partially resistant L. multiflorum genotype infected and not infected with Xtg to identify genes involved in the control of resistance to bacterial wilt. The genes differentially...... expressed upon infection will serve as the basis for the identification of key genes involved in bacterial wilt resistance and to develop molecular markers for marker assisted breeding. Fluorescently labelled cDNA prepared from plant leaves collected at four different time points after infection was...

  14. Modulation of opioid-induced feeding behavior by endogenous nitric oxide in neonatal layer-type chicks.

    Science.gov (United States)

    Alimohammadi, Samad; Zendehdel, Morteza; Babapour, Vahab

    2015-06-01

    The current study was designed to evaluate the effects of central administration of L-arginine (The precursor of nitric oxide), N(G)-nitro-L-arginine methyl ester (L-NAME), a nitric oxide (NO) synthase inhibitor, selective opioid receptor agonists and involvement of central nitrergic/opioidergic systems on feeding behavior in neonatal layer-type chicks. The results of this study showed that the intracerebroventricular (ICV) injection of L-arginine (400 and 800 nmol) significantly decreased food intake (P 0.05). The ICV injection of L-NAME (200 and 400 nmol) increased food intake (P 0.05). On the other hand, the co-injection of 100 nmol L-NAME significantly attenuated the anorexigenic effect of 800 nmol L-arginine (P co-injection of L-arginine or L-NAME with DPDPE had no effect on the hyperphagia induced by DPDPE as well as the hyperphagic effect of U-50488H on food intake was not affected by concurrent injection of L-arginine or L-NAME (P > 0.05). These results suggest that nitrergic and opioidergic systems have an important role on feeding behavior in the CNS of neonatal layer-type chicks and it seems that interaction between them is mediated by μ-opioid receptor. PMID:25677536

  15. Proteophosphoglycan confers resistance of Leishmania major to midgut digestive enzymes induced by blood feeding in vector sand flies.

    Science.gov (United States)

    Secundino, Nagila; Kimblin, Nicola; Peters, Nathan C; Lawyer, Phillip; Capul, Althea A; Beverley, Stephen M; Turco, Salvatore J; Sacks, David

    2010-07-01

    Leishmania synthesize abundant phosphoglycan-containing molecules made up of [Gal-Man-PO(4)] repeating units, including the surface lipophosphoglycan (LPG), and the surface and secreted proteophosphoglycan (PPG). The vector competence of Phlebotomus duboscqi and Lutzomyia longipalpis sand flies was tested using L. major knockout mutants deficient in either total phosphoglycans (lpg2(-) or lpg5A(-)/5B(-)) or LPG alone (lpg1(-)) along with their respective gene add-back controls. Our results confirm that LPG, the major cell surface molecule of Leishmania promastigotes known to mediate attachment to the vector midgut, is necessary to prevent the loss of infection during excretion of the blood meal remnants from a natural vector, P. duboscqi, but not an unnatural vector, L. longipalpis. Midgut digestive enzymes induced by blood feeding pose another potential barrier to parasite survival. Our results show that 36-72 h after the infective feed, all parasites developed well except the lpg2(-) and lpg5A(-)/5B(-) mutants, which showed significantly reduced survival and growth. Protease inhibitors promoted the early survival and growth of lpg2(-) in the blood meal. PPG was shown to be the key molecule conferring resistance to midgut digestive enzymes, as it prevented killing of lpg2(-) promastigotes exposed to midgut lysates prepared from blood-fed flies. The protection was not associated with inhibition of enzyme activities, but with cell surface acquisition of the PPG, which appears to function similar to mammalian mucins to protect the surface of developing promastigotes against proteolytic damage. PMID:20088949

  16. Isolation of Polymer-Degrading Bacteria and Characterization of the Hindgut Bacterial Community from the Detritus-Feeding Larvae of Tipula abdominalis (Diptera: Tipulidae)▿

    OpenAIRE

    Cook, Dana M.; DeCrescenzo Henriksen, Emily; Upchurch, Rima; Peterson, Joy B. Doran

    2007-01-01

    The Tipula abdominalis larval hindgut microbial community presumably facilitates digestion of the lignocellulosic diet. The microbial community was investigated through characterization of bacterial isolates and analysis of 16S rRNA gene clone libraries. This initial study revealed novel bacteria and provides a framework for future studies of this symbiosis.

  17. Antibiotic exposure can induce various bacterial virulence phenotypes in multidrug-resistant Salmonella enterica serovar Typhimurium

    Science.gov (United States)

    Salmonella is one of the most prevalent bacterial foodborne diseases in the United States and causes an estimated 1 million human cases every year. Multidrug-resistant (MDR) Salmonella has emerged as a public health issue as it has been associated with increased morbidity in humans and mortality in...

  18. Plant secondary metabolite-induced shifts in bacterial community structure and degradative ability in contaminated soil

    Czech Academy of Sciences Publication Activity Database

    Uhlík, O.; Musilová, L.; Rídl, Jakub; Hroudová, Miluše; Vlček, Čestmír; Koubek, J.; Holečková, M.; Mackova, M.; Macek, T.

    2013-01-01

    Roč. 97, č. 20 (2013), s. 9245-9256. ISSN 0175-7598 Grant ostatní: EK(XE) 265946; GA MŠk(CZ) ME10041 Institutional support: RVO:68378050 Keywords : plant secondary metabolites (PSM) * bacterial community * metabolic activity * bioremediation * pyrosequencing Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 3.811, year: 2013

  19. Chronic Liver Disease Impairs Bacterial Clearance in a Human Model of Induced Bacteremia

    OpenAIRE

    Ashare, Alix; Stanford, Clark; Hancock, Patricia; Stark, Donna; Lilli, Kathleen; Birrer, Emily; Nymon, Amanda; Doerschug, Kevin C.; Hunninghake, Gary W.

    2009-01-01

    Sepsis often causes impaired hepatic function. Patients with liver disease have an increased risk of bacteremia. This is thought to be secondary to impaired reticuloendothelial system function. However, this has not been demonstrated clinically. Since transient bacteremia occurs following toothbrushing, we hypothesized that subjects with cirrhosis would have impaired bacterial clearance following toothbrushing compared with subjects with pulmonary disease and healthy controls. After baseline ...

  20. Melatonin reduces bacterial translocation and apoptosis in trinitrobenzene sulphonic acid-induced colitis of rats

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    AIM:To investigate the effects of exogenous melatonin on bacterial translocation and apoptosis in a rat ulcerative colitis model.METHODS:Rats were randomly assigned to three groups:group Ⅰ:control,group Ⅱ: experimental colitis,group Ⅲ:colitis plus melatonin treatment.On d 11 after colitis,plasma tumor necrosis factor-α,portal blood endotoxin levels,colon tissue myeloperoxidase and caspase-3 activity were measured.Bacterial translocation was quantified by blood,lymph node,liver and spleen culture.RESULTS:We observed a significantly reduced incidence of bacterial translocation to the liver,spleen,mesenteric lymph nodes,portal and systemic blood in animals treated with melatonin.Treatment with melatonin significantly decreased the caspase-3 activity in colonic tissues compared to that in trinitrobenzene sulphonic acid-treated rats (16.11 ± 2.46 vs 32.97 ± 3.91,P < 0.01).CONCLUSION:Melatonin has a protective effect on bacterial translocation and apoptosis.

  1. A case of septic-shock-induced bacterial translocation during chemoradiotherapy for head and neck cancer

    International Nuclear Information System (INIS)

    Combination therapy such as chemotherapy and radiotherapy is often used for head and neck cancer to maintain potency, but may trigger undesirable adverse effects. A 60-year-old man suddenly developing shock and multiple organ failure during chemoradiotherapy for hypopharyngeal carcinoma required intensive treatment. Bacterial translocation was thought to have caused shock. We discuss clinical features and the diagnostic process. (author)

  2. Short term exposure to elevated trinitrotoluene concentrations induced structural and functional changes in the soil bacterial community

    International Nuclear Information System (INIS)

    We investigated the acute impact of trinitrotoluene (TNT) contamination of soil on the aerobic bacterial community composition and function. The contamination of the environment with explosive residues presents a serious problem at sites across the world, with the highly toxic compound TNT being the most widespread explosive contaminant. We investigated the acute impact of trinitrotoluene (TNT) contamination of soil on the aerobic bacterial community composition and function. Soil microcosms were amended with a range of concentrations of TNT for 30 days. A polyphasic approach encompassing culture-independent molecular analysis by DGGE, community-level physiological profiling (CLPP) and cell enumeration revealed that the amendment of soils with TNT resulted in a shift from slower growing k-strategists towards faster growing r-strategists. Pseudomonads became prevalent at high concentrations of TNT. Pollution induced community tolerance (PICT) was observed as TNT concentrations increased. Chemical analyses revealed that TNT was reduced to its amino derivatives, products of reductive microbial transformation. The transformation to amino derivatives decreased at high concentrations of TNT, indicative of inhibition of microbial TNT transformation. - The bacterial community structure, function and diversity changed when soil was amended with TNT; pseudomonads increased in prevalence and tolerance to TNT toxicity increased

  3. Enhancement of Methacholine-Evoked Tracheal Contraction Induced by Bacterial Lipopolysaccharides Depends on Epithelium and Tumor Necrosis Factor

    Directory of Open Access Journals (Sweden)

    T. Secher

    2012-01-01

    Full Text Available Inhaled bacterial lipopolysaccharides (LPSs induce an acute tumour necrosis factor-alpha (TNF-α- dependent inflammatory response in the murine airways mediated by Toll-like receptor 4 (TLR4 via the myeloid differentiation MyD88 adaptor protein pathway. However, the contractile response of the bronchial smooth muscle and the role of endogenous TNFα in this process have been elusive. We determined the in vivo respiratory pattern of C57BL/6 mice after intranasal LPS administration with or without the presence of increasing doses of methacholine (MCh. We found that LPS administration altered the basal and MCh-evoked respiratory pattern that peaked at 90 min and decreased thereafter in the next 48 h, reaching basal levels 7 days later. We investigated in controlled ex vivo condition the isometric contraction of isolated tracheal rings in response to MCh cholinergic stimulation. We observed that preincubation of the tracheal rings with LPS for 90 min enhanced the subsequent MCh-induced contractile response (hyperreactivity, which was prevented by prior neutralization of TNFα with a specific antibody. Furthermore, hyperreactivity induced by LPS depended on an intact epithelium, whereas hyperreactivity induced by TNFα was well maintained in the absence of epithelium. Finally, the enhanced contractile response to MCh induced by LPS when compared with control mice was not observed in tracheal rings from TLR4- or TNF- or TNF-receptor-deficient mice. We conclude that bacterial endotoxin-mediated hyperreactivity of isolated tracheal rings to MCh depends upon TLR4 integrity that signals the activation of epithelium, which release endogenous TNFα.

  4. Bacterial antigen expression is an important component in inducing an immune response to orally administered Salmonella-delivered DNA vaccines.

    Directory of Open Access Journals (Sweden)

    Michelle E Gahan

    Full Text Available BACKGROUND: The use of Salmonella to deliver heterologous antigens from DNA vaccines is a well-accepted extension of the success of oral Salmonella vaccines in animal models. Attenuated S. typhimurium and S. typhi strains are safe and efficacious, and their use to deliver DNA vaccines combines the advantages of both vaccine approaches, while complementing the limitations of each technology. An important aspect of the basic biology of the Salmonella/DNA vaccine platform is the relative contributions of prokaryotic and eukaryotic expression in production of the vaccine antigen. Gene expression in DNA vaccines is commonly under the control of the eukaryotic cytomegalovirus (CMV promoter. The aim of this study was to identify and disable putative bacterial promoters within the CMV promoter and evaluate the immunogenicity of the resulting DNA vaccine delivered orally by S. typhimurium. METHODOLOGY/PRINCIPAL FINDINGS: The results reported here clearly demonstrate the presence of bacterial promoters within the CMV promoter. These promoters have homology to the bacterial consensus sequence and functional activity. To disable prokaryotic expression from the CMV promoter a series of genetic manipulations were performed to remove the two major bacterial promoters and add a bacteria transcription terminator downstream of the CMV promoter. S. typhimurium was used to immunise BALB/c mice orally with a DNA vaccine encoding the C-fragment of tetanus toxin (TT under control of the original or the modified CMV promoter. Although both promoters functioned equally well in eukaryotic cells, as indicated by equivalent immune responses following intramuscular delivery, only the original CMV promoter was able to induce an anti-TT specific response following oral delivery by S. typhimurium. CONCLUSIONS: These findings suggest that prokaryotic expression of the antigen and co-delivery of this protein by Salmonella are at least partially responsible for the successful

  5. Gamma radiation-induced mutant of NSIC RC144 with broad-spectrum resistance to bacterial blight

    International Nuclear Information System (INIS)

    Mutant lines derived from gamma radiation-treated commercial variety NSIC RC144 were produced and screened for novel resistance to bacterial blight, one of the most serious diseases of rice. Preliminary screening of a bulk M2 population through induced method using race 3 of the pathogen Xanthomonas oryzae pv. oryzae (Xoo) resulted in the selection of 89 resistant plants. Subsequent repeated bacterial blight screenings and generation advance for five seasons resulted in the selection of two highly resistant M7 sister lines whose origin can be traced to a single M2 plant. DNA fingerprinting using 63 genome-wide simple sequence repeat (SSR) markers revealed an identical pattern in these lines. Using the same set of markers, they also exhibited 98% similarity to wild type NSIC RC144 indicating that the resistance is due to mutation and not due to genetic admixture or seed impurity. Two seasons of bacterial blight screening using 14 local isolates representing ten races of Xoo revealed an identical reaction pattern in these lines. The reaction pattern was observed to be unique compared to known patterns in four IRBB isolines (IRBB 4, 5, 7 and 21) with strong resistant reaction to bacterial blight suggesting possible novel resistance. The susceptible reaction in F1 testcrosses using Xoo race 6 and the segregation patterns in two F2 populations that fit with the expected 3 susceptible: 1 resistant ratio (P = 0.4, ns) suggest a single-gene recessive mutation in these lines. These mutants are now being used as resistance donor in the breeding program while further molecular characterization to map and characterize the mutated gene is being pursued

  6. A study on the effect of using mangrove leaf extracts as a feed additive in the progress of bacterial infections in marine ornamental fish

    Institute of Scientific and Technical Information of China (English)

    Thangavelu Balasubramanian; Kapila Tissera

    2013-01-01

    Objective: To ascertain the feasibility of using sustainable natural resources in maintaining disease free fish in such establishments.Methods:causative bacteria were identified by morphology and biochemical techniques. The antibacterial activity and disease resistant capability of mangrove plant leaf extract were investigated against fish pathogens.Results:The infected marine ornamental fishes were collected from the hatchery condition and inhibition activity at the concentration of 220, 200, 175 and 150 µg/mL against Pseudomonas fluorescens, Pseudomonas aeruginosa, Vibrio parahaemolyticus, and Vibrio anguillarum respectively. The experimental trial reveals feeding marine ornamental fish with feed incorporated with a methanol leaf extract of Avicennia marina, increases their survival and reduces their susceptibility to infections from the isolated bacteria. Based on the in vitro assay, methanol extract of Avicennia marina was exhibited good Conclusions: The mangrove leaves have potential to control the infections caused by Pseudomonas fluorescens, Pseudomonas aeruginosa, Vibrio parahaemolyticus and Vibrio anguillarum.

  7. The effect of silencing 20E biosynthesis relative genes by feeding bacterially expressed dsRNA on the larval development of Chilo suppressalis.

    Science.gov (United States)

    Zhu, Jian; Dong, Yong-Cheng; Li, Ping; Niu, Chang-Ying

    2016-01-01

    RNA interference (RNAi) is a robust tool to study gene functions as well as potential for insect pest control. Finding suitable target genes is the key step in the development of an efficient RNAi-mediated pest control technique. Based on the transcriptome of Chilo suppressalis, 24 unigenes which putatively associated with insect hormone biosynthesis were identified. Amongst these, four genes involved in ecdysteroidogenesis i.e., ptth, torso, spook and nm-g were evaluated as candidate targets for function study. The partial cDNA of these four genes were cloned and their bacterially expressed dsRNA were fed to the insects. Results revealed a significant reduction in mRNA abundance of target genes after 3 days. Furthermore, knocked down of these four genes resulted in abnormal phenotypes and high larval mortality. After 15 days, the survival rates of insects in dsspook, dsptth, dstorso, and dsnm-g groups were significantly reduced by 32%, 38%, 56%, and 67% respectively, compared with control. Moreover, about 80% of surviving larvae showed retarded development in dsRNA-treated groups. These results suggest that oral ingestion of bacterially expressed dsRNA in C. suppressalis could silence ptth, torso, spook and nm-g. Oral delivery of bacterially expressed dsRNA provides a simple and potential management scheme against C. suppressalis. PMID:27352880

  8. The effect of silencing 20E biosynthesis relative genes by feeding bacterially expressed dsRNA on the larval development of Chilo suppressalis

    Science.gov (United States)

    Zhu, Jian; Dong, Yong-Cheng; Li, Ping; Niu, Chang-Ying

    2016-01-01

    RNA interference (RNAi) is a robust tool to study gene functions as well as potential for insect pest control. Finding suitable target genes is the key step in the development of an efficient RNAi-mediated pest control technique. Based on the transcriptome of Chilo suppressalis, 24 unigenes which putatively associated with insect hormone biosynthesis were identified. Amongst these, four genes involved in ecdysteroidogenesis i.e., ptth, torso, spook and nm-g were evaluated as candidate targets for function study. The partial cDNA of these four genes were cloned and their bacterially expressed dsRNA were fed to the insects. Results revealed a significant reduction in mRNA abundance of target genes after 3 days. Furthermore, knocked down of these four genes resulted in abnormal phenotypes and high larval mortality. After 15 days, the survival rates of insects in dsspook, dsptth, dstorso, and dsnm-g groups were significantly reduced by 32%, 38%, 56%, and 67% respectively, compared with control. Moreover, about 80% of surviving larvae showed retarded development in dsRNA-treated groups. These results suggest that oral ingestion of bacterially expressed dsRNA in C. suppressalis could silence ptth, torso, spook and nm-g. Oral delivery of bacterially expressed dsRNA provides a simple and potential management scheme against C. suppressalis. PMID:27352880

  9. Spermidine feeding decreases age-related locomotor activity loss and induces changes in lipid composition.

    Directory of Open Access Journals (Sweden)

    Nadège Minois

    Full Text Available Spermidine is a natural polyamine involved in many important cellular functions, whose supplementation in food or water increases life span and stress resistance in several model organisms. In this work, we expand spermidine's range of age-related beneficial effects by demonstrating that it is also able to improve locomotor performance in aged flies. Spermidine's mechanism of action on aging has been primarily related to general protein hypoacetylation that subsequently induces autophagy. Here, we suggest that the molecular targets of spermidine also include lipid metabolism: Spermidine-fed flies contain more triglycerides and show altered fatty acid and phospholipid profiles. We further determine that most of these metabolic changes are regulated through autophagy. Collectively, our data suggests an additional and novel lipid-mediated mechanism of action for spermidine-induced autophagy.

  10. Mechanism of mitochondrial respiratory control in caspase-3 induced positive feed back loop in apoptosis

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Caspase-3 plays a central role in the execution of apoptosis. Besides many substrates of caspase-3, mitochondria seem to be one of the candidate targets in the apoptotic process. We evaluated the effects of caspase-3 on the isolated mitochondria in detail, and especially focused on the mechanism involved in mitochondrial functions, which were not fully assessed till now. Our results showed that recombinant caspase-3 induced the increase of superoxide production, the dissipation of mitochondrial membrane potential and rate increasing of mitochondrial state 4 respiration. Caspases inhibitor, z-VAD-fmk can inhibit these effects of caspase-3 on mitochondria. Bcl-xL and cyclosporin A were also shown to be able to inhibit these changes. These results suggested a possible mechanism in caspase-3 induced disruption of mitochondrial membrane barrier which formed a positive feedback loop in apoptosis.

  11. High-fat feeding inhibits exercise-induced increase in mitochondrial respiratory flux in skeletal muscle

    DEFF Research Database (Denmark)

    Skovbro, Mette; Boushel, Robert Christopher; Hansen, Christina Neigaard;

    2011-01-01

    ) and intramyocellular triacylglycerol content did not change with the intervention in either group. Indexes of mitochondrial density were similar across the groups and intervention. Mitochondrial respiratory rates, measured in permeabilized muscle fibers, showed a 31 ± 11 and 26 ± 9% exercise-induced increase (P ...-62%) were seen in HFD and ND, but only in HFD was an elevated (P respiratory rate seen at recovery. With HFD complex I and IV protein expression decreased (P ... and in exercise-induced mitochondrial substrate oxidation rates, with the effects being present hours after the exercise. The effect of HFD is present even without effects on insulin sensitivity and intramyocellular lipid accumulation. An isocaloric high-fat diet does not cause insulin resistance....

  12. Spermidine Feeding Decreases Age-Related Locomotor Activity Loss and Induces Changes in Lipid Composition

    OpenAIRE

    Nadège Minois; Patrick Rockenfeller; Smith, Terry K; Didac Carmona-Gutierrez

    2014-01-01

    Spermidine is a natural polyamine involved in many important cellular functions, whose supplementation in food or water increases life span and stress resistance in several model organisms. In this work, we expand spermidine's range of age-related beneficial effects by demonstrating that it is also able to improve locomotor performance in aged flies. Spermidine's mechanism of action on aging has been primarily related to general protein hypoacetylation that subsequently induces autophagy. Her...

  13. Ultrastructural and histological changes induced by ivermectin in the ovary of Argas persicus after feeding

    Directory of Open Access Journals (Sweden)

    Hamdy, H.Swelim; Aleya, S.Marzouk;Ashraf,A.M.Montasser

    2003-03-01

    Full Text Available The ovarian wall of A.persicus consists of primary oocytes of three developmental stages namely , young , previtellogenic and vitellogenic in addition to interstitial cells . After feeding and mating , the three stages and interstitial cells , particularly funicle cells that carry oocytes , markedly increased in size and their cytoplasmic organelles exhibit notable changes correlated with yolk and egg shell formation . The present study examined the hitological and ultrastructural aspects during the formation of yolk and egg shell. The first seem to originate from small vesicles derived from Golgi bodies, rough endoplasmic reticulum and mitochondrial cristae. The egg shell seems to develop from vesicles derived from Golgi bodies that fuse with the cell membrane and discharge their content into the extracellular space between basement membrane and tunica propria. Glycogen aggregates and lipid droplets are commonly observed between yolk spheres. The injection of selected dose of ivermectin (400 ug/kg prevented growth and development of oocytes. The ovary appeared studded with young and previtellogenic primary oocytes surrounding a narrow ovarian lumen or the ovarian wall, carrying oocytes, is stretched around a large fluid filled lumen. Surface microvilli of primary oocytes and coated vesicles underlying them became comparatively fewer. Mitochondria and rough endoplasmic reticulum became fewer, fragmented and finally degenerated in primary oocytes and funicle cells. Ivermectin interfered with the formation of yolk granules and egg shell. However, in the few formed vitellogenic oocytes, Golgi bodies were not affected. The egg shell appeared thinner with low electron density. The cytoplasm of funicle cells became highly vacuolated, its organelles, hardly distinguished and nuclei became swollen without definite nuclear membrane. Ivermectin completely prevented the formation of glycogen particles. Our results suggests that ivermectin causes partial

  14. Finding immune gene expression differences induced by marine bacterial pathogens in the Deep-sea hydrothermal vent mussel Bathymodiolus azoricus

    Science.gov (United States)

    Martins, E.; Queiroz, A.; Serrão Santos, R.; Bettencourt, R.

    2013-11-01

    The deep-sea hydrothermal vent mussel Bathymodiolus azoricus lives in a natural environment characterised by extreme conditions of hydrostatic pressure, temperature, pH, high concentrations of heavy metals, methane and hydrogen sulphide. The deep-sea vent biological systems represent thus the opportunity to study and provide new insights into the basic physiological principles that govern the defense mechanisms in vent animals and to understand how they cope with microbial infections. Hence, the importance of understanding this animal's innate defense mechanisms, by examining its differential immune gene expressions toward different pathogenic agents. In the present study, B. azoricus mussels were infected with single suspensions of marine bacterial pathogens, consisting of Vibrio splendidus, Vibrio alginolyticus, or Vibrio anguillarum, and a pool of these Vibrio bacteria. Flavobacterium suspensions were also used as a non-pathogenic bacterium. Gene expression analyses were carried out using gill samples from infected animals by means of quantitative-Polymerase Chain Reaction aimed at targeting several immune genes. We also performed SDS-PAGE protein analyses from the same gill tissues. We concluded that there are different levels of immune gene expression between the 12 h to 24 h exposure times to various bacterial suspensions. Our results from qPCR demonstrated a general pattern of gene expression, decreasing from 12 h over 24 h post-infection. Among the bacteria tested, Flavobacterium is the bacterium inducing the highest gene expression level in 12 h post-infections animals. The 24 h infected animals revealed, however, greater gene expression levels, using V. splendidus as the infectious agent. The SDS-PAGE analysis also pointed at protein profile differences between 12 h and 24 h, particularly evident for proteins of 18-20 KDa molecular mass, where most dissimilarity was found. Multivariate analyses demonstrated that immune genes, as well as experimental

  15. Murine lymphoid procoagulant activity induced by bacterial lipopolysaccharide and immune complexes is a monocyte prothrombinase

    OpenAIRE

    Schwartz, BS; Levy, GA; Fair, DS; Edgington, TS

    1982-01-01

    Murine lymphoid cells respond rapidly to bacterial lipopolysaccharide or antigen-antibody complexes to initiate or accelerate the blood coagulation pathways. The monocyte or macrophage has been identified as the cellular source, although lymphocyte collaboration is required for the rapid induction of the procoagulant response. This procoagulant activity is identified in the present study as a direct prothrombin activator, i.e., a prothrombinase. Studies with plasmas deficient in single coagul...

  16. NaOH-Debittering Induces Changes in Bacterial Ecology during Table Olives Fermentation

    OpenAIRE

    Cocolin, Luca; Alessandria, Valentina; Botta, Cristian; Gorra, Roberta; De Filippis, Francesca; Ercolini, Danilo; Rantsiou, Kalliopi

    2013-01-01

    Limited information is available on the impact of the NaOH treatment on table olive fermentations, and for this reason a polyphasic approach has been adopted here to investigate its effect on the fermentation dynamics and bacterial biodiversity. The microbial counts of the main groups involved in the transformation have not shown any differences, apart from a more prompt start of the fermentation when the olives were subjected to the NaOH treatment. The data produced by culture-independent an...

  17. Macroalgal Extracts Induce Bacterial Assemblage Shifts and Sublethal Tissue Stress in Caribbean Corals

    OpenAIRE

    Morrow, Kathleen M.; Raphael Ritson-Williams; Cliff Ross; Mark R Liles; Paul, Valerie J

    2012-01-01

    Benthic macroalgae can be abundant on present-day coral reefs, especially where rates of herbivory are low and/or dissolved nutrients are high. This study investigated the impact of macroalgal extracts on both coral-associated bacterial assemblages and sublethal stress response of corals. Crude extracts and live algal thalli from common Caribbean macroalgae were applied onto the surface of Montastraea faveolata and Porites astreoides corals on reefs in both Florida and Belize. Denaturing grad...

  18. Induced Bacterial Cross-Resistance toward Host Antimicrobial Peptides: A Worrying Phenomenon

    OpenAIRE

    Fleitas, Osmel; Franco, Octávio L.

    2016-01-01

    Bacterial resistance to conventional antibiotics has reached alarming levels, threatening to return to the pre-antibiotic era. Therefore, the search for new antimicrobial compounds that overcome the resistance phenomenon has become a priority. Antimicrobial peptides (AMPs) appear as one of the most promising antibiotic medicines. However, in recent years several AMP-resistance mechanisms have been described. Moreover, the AMP-resistance phenomenon has become more complex due to its associatio...

  19. Inducible Resistance of Fish Bacterial Pathogens to the Antimicrobial Peptide Cecropin B▿

    OpenAIRE

    Sallum, Ulysses W.; Chen, Thomas T

    2008-01-01

    Cecropin B is a cationic antimicrobial peptide originally isolated from the diapausing pupae of the giant silk moth, Hylphora cecropia. Cecropin B elicits its antimicrobial effects through disruption of the anionic cell membranes of gram-negative bacteria. Previous work by our laboratory demonstrated that a constitutively expressed cecropin B transgene conferred enhanced resistance to bacterial infection in medaka. The development of antibiotic resistance by pathogenic bacteria is a growing p...

  20. Surviving Bacterial Sibling Rivalry: Inducible and Reversible Phenotypic Switching in Paenibacillus dendritiformis

    OpenAIRE

    Be’er, Avraham; Florin, E.-L.; Fisher, Carolyn R; Swinney, Harry L.; Payne, Shelley M.

    2011-01-01

    IMPORTANCE In favorable environments, species may face space and nutrient limits due to overcrowding. Bacteria provide an excellent model for analyzing principles underlying overcrowding and regulation of density in nature, since their population dynamics can be easily and accurately assessed under controlled conditions. We describe a newly discovered mechanism for survival of a bacterial population during overcrowding. When competing with sibling colonies, Paenibacillus dendritiformis produc...

  1. Oral mucosal lipids are antibacterial against Porphyromonas gingivalis, induce ultrastructural damage, and alter bacterial lipid and protein compositions

    Institute of Scientific and Technical Information of China (English)

    Carol L Fischer; Katherine S Walters; David R Drake; Deborah V Dawson; Derek R Blanchette; Kim A Brogden; Philip W Wertz

    2013-01-01

    Oral mucosal and salivary lipids exhibit potent antimicrobial activity for a variety of Gram-positive and Gram-negative bacteria;however, little is known about their spectrum of antimicrobial activity or mechanisms of action against oral bacteria. In this study, we examine the activity of two fatty acids and three sphingoid bases against Porphyromonas gingivalis, an important colonizer of the oral cavity implicated in periodontitis. Minimal inhibitory concentrations, minimal bactericidal concentrations, and kill kinetics revealed variable, but potent, activity of oral mucosal and salivary lipids against P. gingivalis, indicating that lipid structure may be an important determinant in lipid mechanisms of activity against bacteria, although specific components of bacterial membranes are also likely important. Electron micrographs showed ultrastructural damage induced by sapienic acid and phytosphingosine and confirmed disruption of the bacterial plasma membrane. This information, coupled with the association of treatment lipids with P. gingivalis lipids revealed via thin layer chromatography, suggests that the plasma membrane is a likely target of lipid antibacterial activity. Utilizing a combination of two-dimensional in-gel electrophoresis and Western blot followed by mass spectroscopy and N-terminus degradation sequencing we also show that treatment with sapienic acid induces upregulation of a set of proteins comprising a unique P. gingivalis stress response, including proteins important in fatty acid biosynthesis, metabolism and energy production, protein processing, cell adhesion and virulence. Prophylactic or therapeutic lipid treatments may be beneficial for intervention of infection by supplementing the natural immune function of endogenous lipids on mucosal surfaces.

  2. Inducible expression of p50 from TMV for increased resistance to bacterial crown gall disease in tobacco.

    Science.gov (United States)

    Niemeyer, Julia; Ruhe, Jonas; Machens, Fabian; Stahl, Dietmar J; Hehl, Reinhard

    2014-01-01

    The dominant tobacco mosaic virus (TMV) resistance gene N induces a hypersensitive response upon TMV infection and protects tobacco against systemic spread of the virus. It has been proposed to change disease resistance specificity by reprogramming the expression of resistance genes or their corresponding avirulence genes. To reprogramme the resistance response of N towards bacterial pathogens, the helicase domain (p50) of the TMV replicase, the avirulence gene of N, was linked to synthetic promoters 4D and 2S2D harbouring elicitor-responsive cis-elements. These promoter::p50 constructs induce local necrotic lesions on NN tobacco plants in an Agrobacterium tumefaciens infiltration assay. A tobacco genotype void of N (nn) was transformed with the promoter::p50 constructs and subsequently crossed to NN plants. Nn F1 offspring selected for the T-DNA develop normally under sterile conditions. After transfer to soil, some of the F1 plants expressing the 2S2D::p50 constructs develop spontaneous necrosis. Transgenic Nn F1 plants with 4D::p50 and 2S2D::p50 expressing constructs upregulate p50 transcription and induce local necrotic lesions in an A. tumefaciens infiltration assay. When leaves and stems of Nn F1 offspring harbouring promoter::p50 constructs are infected with oncogenic A. tumefaciens C58, transgenic lines harbouring the 2S2D::p50 construct induce necrosis and completely lack tumor development. These results demonstrate a successful reprogramming of the viral N gene response against bacterial crown gall disease and highlight the importance of achieving tight regulation of avirulence gene expression and the control of necrosis in the presence of the corresponding resistance gene. PMID:23955710

  3. ST2 negatively regulates TLR2 signaling, but is not required for bacterial lipoprotein-induced tolerance.

    LENUS (Irish Health Repository)

    Liu, Jinghua

    2010-05-15

    Activation of TLR signaling is critical for host innate immunity against bacterial infection. Previous studies reported that the ST2 receptor, a member of the Toll\\/IL-1 receptor superfamily, functions as a negative regulator of TLR4 signaling and maintains LPS tolerance. However, it is undetermined whether ST2 negatively regulates TLR2 signaling and furthermore, whether a TLR2 agonist, bacterial lipoprotein (BLP)-induced tolerance is dependent on ST2. In this study, we show that BLP stimulation-induced production of proinflammatory cytokines and immunocomplex formation of TLR2-MyD88 and MyD88-IL-1R-associated kinase (IRAK) were significantly enhanced in ST2-deficient macrophages compared with those in wild-type controls. Furthermore, overexpression of ST2 dose-dependently attenuated BLP-induced NF-kappaB activation, suggesting a negative regulatory role of ST2 in TLR2 signaling. A moderate but significantly attenuated production of TNF-alpha and IL-6 on a second BLP stimulation was observed in BLP-pretreated, ST2-deficient macrophages, which is associated with substantially reduced IRAK-1 protein expression and downregulated TLR2-MyD88 and MyD88-IRAK immunocomplex formation. ST2-deficient mice, when pretreated with a nonlethal dose of BLP, benefitted from an improved survival against a subsequent lethal BLP challenge, indicating BLP tolerance develops in the absence of the ST2 receptor. Taken together, our results demonstrate that ST2 acts as a negative regulator of TLR2 signaling, but is not required for BLP-induced tolerance.

  4. Anticonvulsant effect of time-restricted feeding in a pilocarpine-induced seizure model: Metabolic and epigenetic implications.

    Directory of Open Access Journals (Sweden)

    Jorge eLandgrave-Gómez

    2016-01-01

    Full Text Available A new generation of antiepileptic drugs has emerged; however, one-third of epilepsy patients do not properly respond to pharmacological treatments. The purpose of the present study was to investigate whether time-restricted feeding has an anticonvulsant effect and whether this restrictive diet promotes changes in energy metabolism and epigenetic modifications in a pilocarpine-induced seizure model. To resolve our hypothesis, one group of rats had free access to food and water ad libitum (AL and a second group underwent a time-restricted feeding (TRF schedule. We used the lithium-pilocarpine model to induce status epilepticus (SE, and behavioral seizure monitoring was analyzed. Additionally, an electroencephalography (EEG recording was performed to verify the effect of TRF on cortical electrical activity after a pilocarpine injection. For biochemical analysis, animals were sacrificed 24 hours after SE and hippocampal homogenates were used to evaluate the proteins related to metabolism and chromatin structure. Our results showed that TRF had an anticonvulsant effect as measured by the prolonged latency of forelimb clonus seizure, a decrease in the seizure severity score and fewer animals reaching SE. Additionally, the power of the late phase EEG recordings in the AL group was significantly higher than the TRF group. Moreover, we found that TRF is capable of inducing alterations in signaling pathways that regulate energy metabolism, including an increase in the phosphorylation of AMP dependent kinase (AMPK and a decrease in the phosphorylation of Akt kinase. Furthermore, we found that TRF was able to significantly increase the beta hydroxybutyrate (β-HB concentration, an endogenous inhibitor of histone deacetylases (HDACs. Finally, we found a significant decrease in HDAC activity as well as an increase in acetylation on histone 3 (H3 in hippocampal homogenates from the TRF group. These findings suggest that alterations in energy metabolism and the

  5. Bacterial carbonatogenesis

    International Nuclear Information System (INIS)

    Several series of experiments in the laboratory as well as in natural conditions teach that the production of carbonate particles by heterotrophic bacteria follows different ways. The 'passive' carbonatogenesis is generated by modifications of the medium that lead to the accumulation of carbonate and bicarbonate ions and to the precipitation of solid particles. The 'active' carbonatogenesis is independent of the metabolic pathways. The carbonate particles are produced by ionic exchanges through the cell membrane following still poorly known mechanisms. Carbonatogenesis appears to be the response of heterotrophic bacterial communities to an enrichment of the milieu in organic matter. The active carbonatogenesis seems to start first. It is followed by the passive one which induces the growth of initially produced particles. The yield of heterotrophic bacterial carbonatogenesis and the amounts of solid carbonates production by bacteria are potentially very high as compared to autotrophic or chemical sedimentation from marine, paralic or continental waters. Furthermore, the bacterial processes are environmentally very ubiquitous; they just require organic matter enrichment. Thus, apart from purely evaporite and autotrophic ones, all Ca and/or Mg carbonates must be considered as from heterotrophic bacterial origin. By the way, the carbon of carbonates comes from primary organic matter. Such considerations ask questions about some interpretations from isotopic data on carbonates. Finally, bacterial heterotrophic carbonatogenesis appears as a fundamental phase in the relationships between atmosphere and lithosphere and in the geo-biological evolution of Earth. (author)

  6. LINE-1 Hypomethylation in a Choline-Deficiency-Induced Liver Cancer in Rats: Dependence on Feeding Period

    Directory of Open Access Journals (Sweden)

    2006-01-01

    Full Text Available Chronic feeding of methyl-donor (methionine, choline, folic acid, and vitamin B12 deficient diet induces hepatocellular carcinoma formation in rats. Previous studies have shown that promoter CpG islands in various cancer-related genes are aberrantly methylated in this model. Moreover, the global genome in methyl-donor-deficient diet fed rats contains a lesser amount of 5-methylcytosine than control livers. It is speculated that more than 90% of all 5-methylcytosines lie within the CpG islands of the transposons, including the long/short interspersed nucleotide elements (LINE and SINE. It is considered that the 5-methylcytosines in LINE-1 limit the ability of retrotransposons to be activated and transcribed; therefore, the extent of hypomethylation of LINE-1 could be a surrogate marker for aberrant methylation in other tumor-related genes as well as genome instability. Additionally, LINE-1 methylation status has been shown to be a good indicator of genome-wide methylation. In this study, we determined cytosine methylation status in the LINE-1 repetitive sequences of rats fed a choline-deficient (CD diet for various durations and compared these with rats fed a choline-sufficient (CS diet. The methylation status of LINE-1 was assessed by the combined bisulfite restriction analysis (COBRA method, where the amount of bisulfite-modified and RsaI-cleaved DNA was quantified using gel electrophoresis. Progressive hypomethylation was observed in LINE-1 of CD livers as a function of feeding time; that is, the amount of cytosine in total cytosine (methylated and unmethylated increased from 11.1% (1 week to 19.3% (56 weeks, whereas in the control CS livers, it increased from 9.2% to 12.9%. Hypomethylation in tumor tissues was slightly higher (6% than the nontumorous surrounding tissue. The present result also indicates that age is a factor influencing the extent of cytosine methylation.

  7. RSS Feeds

    Science.gov (United States)

    ... www.nlm.nih.gov/medlineplus/rss.html RSS Feeds To use the sharing features on this page, ... NLM RSS Feeds and Podcasts . General Interest RSS Feeds What's New: MedlinePlus Announcements and Special Features The ...

  8. Dominant Aerobic Bacterial Community of Sea Bass (Dicentrarchus Labrax L.1758) Larvae During Weaning from Artemia to Dry Feed in Culture Conditions

    OpenAIRE

    AYAZ, Ayberk; KARATAŞ*, Süheyla

    2010-01-01

    The aim of this study was to determine the dominant aerobic bacterial community of sea bass larvae during their weaning period in 2 different marine hatcheries in Muğla-Bodrum region. Samplings were made in January, March, and May 2005. Larvae and water samples were diluted in certain ratios and were inoculated to Marine Agar, TCBS Agar, Pseudomonas Agar, King Bee Agar, MRS agar, Blood Agar and Plate Count Agar, in that order. Water temperature, pH, saturation, salinity, and features of the s...

  9. Cadmium Bio sorption by Some Bacterial Isolates and Their Mutants Induced by gamma Radiation

    International Nuclear Information System (INIS)

    Cadmium bio sorption by bacterial cells is recognized as a potential alternative to existing recovery technologies. Bacterial strains under investigation were isolated from air surrounding gamma industrial facility Co 60 source of the NCRRT, Cairo. The effect of different concentrations of cadmium on the growth was determined for the spore forming bacteria B.coagulans, B.megaterium, B.pumilus, B.pantothenticus, and also for Staphylo coccus aureus, the reference standard strain used in these study for comparison was B.subtilis MERK 10646. The results indicated that, B.pantothenticus was the most tolerant isolate, and it can resist up to 400 ppm. Cadmium capacity for B.subtilis parent strain was increased through the influence of different doses of gamma radiation, selected mutant of B.subtilis show enhanced level of cadmium accumulation. The effect of environmental parameters as ph, temperature and also the effect of biomass factor on cadmium uptake by B.pantothenticus and B.subtilis (m) was traced

  10. Bacterial gastroenteritis

    Science.gov (United States)

    Infectious diarrhea - bacterial gastroenteritis; Acute gastroenteritis; Gastroenteritis - bacterial ... Bacterial gastroenteritis can affect 1 person or a group of people who all ate the same food. It is ...

  11. A membrane-bound matrix-metalloproteinase from Nicotiana tabacum cv. BY-2 is induced by bacterial pathogens

    Directory of Open Access Journals (Sweden)

    Wahner Verena

    2009-06-01

    Full Text Available Abstract Background Plant matrix metalloproteinases (MMP are conserved proteolytic enzymes found in a wide range of monocotyledonous and dicotyledonous plant species. Acting on the plant extracellular matrix, they play crucial roles in many aspects of plant physiology including growth, development and the response to stresses such as pathogen attack. Results We have identified the first tobacco MMP, designated NtMMP1, and have isolated the corresponding cDNA sequence from the tobacco suspension cell line BY-2. The overall domain structure of NtMMP1 is similar to known MMP sequences, although certain features suggest it may be constitutively active rather than dependent on proteolytic processing. The protein appears to be expressed in two forms with different molecular masses, both of which are enzymatically active as determined by casein zymography. Exchanging the catalytic domain of NtMMP1 with green fluorescent protein (GFP facilitated subcellular localization by confocal laser scanning microscopy, showing the protein is normally inserted into the plasma membrane. The NtMMP1 gene is expressed constitutively at a low level but can be induced by exposure to bacterial pathogens. Conclusion Our biochemical analysis of NtMMP1 together with bioinformatic data on the primary sequence indicate that NtMMP1 is a constitutively-active protease. Given its induction in response to bacterial pathogens and its localization in the plasma membrane, we propose a role in pathogen defense at the cell periphery.

  12. Procalcitonin neutralizes bacterial LPS and reduces LPS-induced cytokine release in human peripheral blood mononuclear cells

    Directory of Open Access Journals (Sweden)

    Matera Giovanni

    2012-05-01

    Full Text Available Abstract Background Procalcitonin (PCT is a polypeptide with several cationic aminoacids in its chemical structure and it is a well known marker of sepsis. It is now emerging that PCT might exhibit some anti-inflammatory effects. The present study, based on the evaluation of the in vitro interaction between PCT and bacterial lipopolisaccharide (LPS, reports new data supporting the interesting and potentially useful anti-inflammatory activity of PCT. Results PCT significantly decreased (p Salmonella typhimurium (rough chemotype and Escherichia coli (smooth chemotype. Subsequently, the in vitro effects of PCT on LPS-induced cytokine release were studied in human peripheral blood mononuclear cells (PBMC. When LPS was pre-incubated for 30 minutes with different concentrations of PCT, the release of interleukin-10 (IL-10 and tumor necrosis factor alpha (TNFα by PBMC decreased in a concentration-dependent manner after 24 hours for IL-10 and 4 hours for TNFα. The release of monocyte chemotactic protein-1 (MCP-1 exhibited a drastic reduction at 4 hours for all the PCT concentrations assessed, whereas such decrease was concentration-dependent after 24 hours. Conclusions This study provides the first evidence of the capability of PCT to directly neutralize bacterial LPS, thus leading to a reduction of its major inflammatory mediators.

  13. Long-term Hg pollution-induced structural shifts of bacterial community in the terrestrial isopod (Porcellio scaber) gut

    Energy Technology Data Exchange (ETDEWEB)

    Lapanje, Ales, E-mail: ales@ifb.s [Institute of Physical Biology, Ljubljana (Slovenia); Zrimec, Alexis [Institute of Physical Biology, Ljubljana (Slovenia); Drobne, Damjana [Department of Biology, Biotechnical Faculty, University of Ljubljana, Ljubljana (Slovenia); Rupnik, Maja [Institute of Public Health Maribor, Maribor (Slovenia)

    2010-10-15

    In previous studies we detected lower species richness and lower Hg sensitivity of the bacteria present in egested guts of Porcellio scaber (Crustacea, Isopoda) from chronically Hg polluted than from unpolluted environment. Basis for such results were further investigated by sequencing of 16S rRNA genes of mercury-resistant (Hg{sup r}) isolates and clone libraries. We observed up to 385 times higher numbers of Hg{sup r} bacteria in guts of animals from polluted than from unpolluted environment. The majority of Hg{sup r} strains contained merA genes. Sequencing of 16S rRNA clones from egested guts of animals from Hg-polluted environments showed elevated number of bacteria from Pseudomonas, Listeria and Bacteroidetes relatives groups. In animals from pristine environment number of bacteria from Achromobacter relatives, Alcaligenes, Paracoccus, Ochrobactrum relatives, Rhizobium/Agrobacterium, Bacillus and Microbacterium groups were elevated. Such bacterial community shifts in guts of animals from Hg-polluted environment could significantly contribute to P. scaber Hg tolerance. - Chronic environmental mercury pollution induces bacterial community shifts and presence of elevated number as well as increased diversity of Hg-resistant bacteria in guts of isopods.

  14. Natural Pig Plasma Immunoglobulins Have Anti-Bacterial Effects: Potential for Use as Feed Supplement for Treatment of Intestinal Infections in Pigs

    DEFF Research Database (Denmark)

    Hedegaard, Chris Juul; Strube, Mikael Lenz; Hansen, Marie B.;

    2016-01-01

    plasma and given as a feed supplement can be used in modern swine production as an efficient and cost-effective means for reducing both occurrence of PWD and antibiotics usage and with a potential for the prevention and treatment of other intestinal infectious diseases even if the causative agent might......There is an increasing demand for non-antibiotics solutions to control infectious disease in intensive pig production. Here, one such alternative, namely pig antibodies purified from slaughterhouse blood was investigated in order to elucidate its potential usability to control post......-weaning diarrhoea (PWD), which is one of the top indications for antibiotics usage in the pig production. A very cost-efficient and rapid one-step expanded bed adsorption (EBA) chromatography procedure was used to purify pig immunoglobulin G from slaughterhouse pig plasma (more than 100 litres), resulting in >85...

  15. Attenuation of Zn-induced hyperleptinemia/leptin resistance in Wistar rat after feeding modified poultry egg

    Directory of Open Access Journals (Sweden)

    Taneja Satish

    2012-09-01

    Full Text Available Abstract Background The prevalence of obesity is increasing exponentially world over. Leptin resistance/hyperleptinemia is attributed to its cause in majority of the obese humans where mutation in genetic component or ob gene has not been found operative. The generation of oxidative stress was suggested as its cause. In our previous study, we have reported that the inclusion of antioxidant enriched modified poultry egg (ME in diet reversed the ionic imbalance and ameliorated the oxidative stress caused by excessive Zn in diet. In the present study, the efficacy of ME verses conventional egg (CE was tested on Zn-induced leptin resistance in rat model to ascertain if the supplementation of antioxidants in the form of egg can reverse Zn-induced leptin resistance to leptin sensitive state. Methods Hyperleptinemia was induced in rats by feeding them Zn-supplemented hyperleptinemic diets-I and II (Zn-HL-Diet for 2 months. Thereafter, half of them were fed either on CE or ME mixed Zn-HL-diets I and II for another two months. The data was analyzed applying one way Anova and Tukey’s HSD post hoc test. Results The results revealed that food intake, gain in body weight, height and number/unit surface area of intestinal microvillus and serum leptin, glucose, insulin and cortisol were higher in CE and Zn-HL-Diet treated groups; serum Zn, Cu, Mg were higher and Cu and Mg in tissues were lower in them than the control group. In ME treated groups, these parameters were lower and were close to the control group. These changes resulted from the restoration of ionic balance of Zn, Cu and Mg in the blood serum and tissues including liver and hair in ME treated rats. Conclusion The data suggest that Zn-induced leptin resistance can be attenuated through restoring the ionic balance of Zn, Cu and Mg through inclusion of antioxidants in diet such as these modified eggs. But further clinical studies are required before they are put to use for human consumption.

  16. Scaling of suction-induced flows in bluegill: morphological and kinematic predictors for the ontogeny of feeding performance.

    Science.gov (United States)

    Holzman, Roi; Collar, David C; Day, Steven W; Bishop, Kristin L; Wainwright, Peter C

    2008-08-01

    During ontogeny, animals undergo changes in size and shape that result in shifts in performance, behavior and resource use. These ontogenetic changes provide an opportunity to test hypotheses about how the growth of structures affects biological functions. In the present study, we ask how ontogenetic changes in skull biomechanics affect the ability of bluegill sunfish, a high-performance suction feeder, to produce flow speeds and accelerations during suction feeding. The flow of water in front of the mouth was measured directly for fish ranging from young-of-year to large adults, using digital particle imaging velocimetry (DPIV). As bluegill size increased, the magnitude of peak flow speed they produced increased, and the effective suction distance increased because of increasing mouth size. However, throughout the size range, the timing of peak fluid speed remained unchanged, and flow was constrained to approximately one gape distance from the mouth. The observed scaling relationships between standard length and peak flow speed conformed to expectations derived from two biomechanical models, one based on morphological potential to produce suction pressure (the Suction Index model) and the other derived from a combination of morphological and kinematic variables (the Expanding Cone model). The success of these models in qualitatively predicting the observed allometry of induced flow speed reveals that the scaling of cranial morphology underlies the scaling of suction performance in bluegill. PMID:18689419

  17. Lactobacillus rhamnosus CCFM1107 treatment ameliorates alcohol-induced liver injury in a mouse model of chronic alcohol feeding.

    Science.gov (United States)

    Tian, Fengwei; Chi, Feifei; Wang, Gang; Liu, Xiaoming; Zhang, Qiuxiang; Chen, Yongquan; Zhang, Hao; Chen, Wei

    2015-12-01

    Lactobacillus rhamnosus CCFM1107 was screened for high antioxidative activity from 55 lactobacilli. The present study attempted to explore the protective properties of L. rhamnosus CCFM1107 in alcoholic liver injury. A mouse model was induced by orally feeding alcohol when simultaneously treated with L. rhamnosus CCFM1107, the drug Hu-Gan- Pian (HGP), L. rhamnosus GG (LGG), and L. plantarum CCFM1112 for 3 months. Biochemical analysis was performed for both serum and liver homogenate. Detailed intestinal flora and histological analyses were also carried out. Our results indicated that the administration of L. rhamnosus CCFM1107 significantly inhibited the increase in the levels of serum aminotransferase and endotoxin, as well as the levels of triglyceride (TG) and cholesterol (CHO) in the serum and in the liver. Glutathione (GSH), glutathione peroxidase (GSH-Px) and superoxide dismutase (SOD) were elevated while the levels of malondialdehyde (MDA) were decreased. The enteric dysbiosis caused by alcohol was restored by increasing the numbers of both lactobacilli and bifidobacteria and decreasing the numbers of both enterococci and enterobacter. Histological analysis confirmed the protective effect of L. rhamnosus CCFM1107. Compared with the other lactobacilli and to the drug Hu-Gan-Pian, there is a high chance that L. rhamnosus CCFM1107 provides protective effects on alcoholic liver injury by reducing oxidative stress and restoring the intestinal flora. PMID:26626356

  18. Muscle physiology changes induced by every other day feeding and endurance exercise in mice: effects on physical performance.

    Directory of Open Access Journals (Sweden)

    Elizabeth Rodríguez-Bies

    Full Text Available Every other day feeding (EOD and exercise induce changes in cell metabolism. The aim of the present work was to know if both EOD and exercise produce similar effects on physical capacity, studying their physiological, biochemical and metabolic effects on muscle. Male OF-1 mice were fed either ad libitum (AL or under EOD. After 18 weeks under EOD, animals were also trained by using a treadmill for another 6 weeks and then analyzed for physical activity. Both, EOD and endurance exercise increased the resistance of animals to extenuating activity and improved motor coordination. Among the groups that showed the highest performance, AL and EOD trained animals, ALT and EODT respectively, only the EODT group was able to increase glucose and triglycerides levels in plasma after extenuating exercise. No high effects on mitochondrial respiratory chain activities or protein levels neither on coenzyme Q levels were found in gastrocnemius muscle. However, exercise and EOD did increase β-oxidation activity in this muscle accompanied by increased CD36 levels in animals fed under EOD and by changes in shape and localization of mitochondria in muscle fibers. Furthermore, EOD and training decreased muscle damage after strenuous exercise. EOD also reduced the levels of lipid peroxidation in muscle. Our results indicate that EOD improves muscle performance and resistance by increasing lipid catabolism in muscle mitochondria at the same time that prevents lipid peroxidation and muscle damage.

  19. Effect of acidic electrolyzed water-induced bacterial inhibition and injury in live clam (Venerupis philippinarum) and mussel (Mytilus edulis).

    Science.gov (United States)

    Al-Qadiri, Hamzah M; Al-Holy, Murad A; Shiroodi, Setareh Ghorban; Ovissipour, Mahmoudreza; Govindan, Byju N; Al-Alami, Nivin; Sablani, Shyam S; Rasco, Barbara

    2016-08-16

    The effect of acidic electrolyzed water (AEW) on inactivating Escherichia coli O104:H4, Listeria monocytogenes, Aeromonas hydrophila, Vibrio parahaemolyticus and Campylobacter jejuni in laboratory contaminated live clam (Venerupis philippinarum) and mussel (Mytilus edulis) was investigated. The initial levels of bacterial contamination were: in clam 4.9 to 5.7log10CFU/g, and in mussel 5.1 to 5.5log10CFU/g. Two types of AEW were used for treatment time intervals of 1 and 2h: strong (SAEW) with an available chlorine concentration (ACC) of 20mg/L, pH=3.1, and an oxidation-reduction potential (ORP) of 1150mV, and weak (WAEW) at ACC of 10mg/L, pH=3.55 and ORP of 950mV. SAEW and WAEW exhibited significant inhibitory activity against inoculated bacteria in both shellfish species with significant differences compared to saline solutions treatments (1-2% NaCl) and untreated controls (0h). SAEW showed the largest inhibitory activity, the extent of reduction (log10CFU/g) ranged from 1.4-1.7 for E. coli O104:H4; 1.0-1.6 for L. monocytogenes; 1.3-1.6 for A. hydrophila; 1.0-1.5 for V. parahaemolyticus; and 1.5-2.2 for C. jejuni in both types of shellfish. In comparison, significantly (Pmonocytogenes; 0.6-1.3 for A. hydrophila; 0.7-1.3 for V. parahaemolyticus; and 0.8-1.9 for C. jejuni in both types of shellfish. Among all bacterial strains examined in this study, AEW induced less bacterial injury (~0.1-1.0log10CFU/g) and more inactivation effect. This study revealed that AEW (10-20mg/L ACC) could be used to reduce bacterial contamination in live clam and mussel, which may help control possible unhygienic practices during production and processing of shellfish without apparent changes in the quality of the shellfish. PMID:27208583

  20. A novel multi-stage subunit vaccine against paratuberculosis induces significant immunity and reduces bacterial burden in tissues (P4304)

    DEFF Research Database (Denmark)

    Thakur, Aneesh; Aagaard, Claus; Riber, Ulla; Skovgaard, Kerstin; Andersen, Peter; Jungersen, Gregers

    Effective control of paratuberculosis is hindered by lack of a vaccine preventing infection, transmission and without diagnostic interference with tuberculosis. We have developed a novel multi-stage recombinant subunit vaccine in which a fusion of four early expressed MAP antigens is combined with...... followed for a year. The FET11 vaccine induced a significant T cell response against constituent vaccine proteins characterized by a high percentage of CD4+ T cells and participation of polyfunctional CD4+ T cells. Of the two different age groups, late FET11 vaccination conferred protective immunity...... characterized by a significant containment of bacterial burden in gut tissues compared to non-vaccinated animals. There was no cross-reaction with bovine tuberculosis in vaccinated animals. This novel multi-stage vaccine has the potential to become a marker vaccine for paratuberculosis....

  1. Carbon dioxide and hydrogen sulfide associations with regional bacterial diversity patterns in microbially induced concrete corrosion.

    Science.gov (United States)

    Ling, Alison L; Robertson, Charles E; Harris, J Kirk; Frank, Daniel N; Kotter, Cassandra V; Stevens, Mark J; Pace, Norman R; Hernandez, Mark T

    2014-07-01

    The microbial communities associated with deteriorating concrete corrosion fronts were characterized in 35 samples taken from wastewater collection and treatment systems in ten utilities. Bacterial communities were described using Illumina MiSeq sequencing of the V1V2 region of the small subunit ribosomal ribonucleic acid (SSU-rRNA) gene recovered from fresh corrosion products. Headspace gas concentrations (hydrogen sulfide, carbon dioxide, and methane), pore water pH, moisture content, and select mineralogy were tested for correlation to community outcomes and corrosion extent using pairwise linear regressions and canonical correspondence analysis. Corroding concrete was most commonly characterized by moisture contents greater than 10%, pore water pH below one, and limited richness (100 ppm) and carbon dioxide (>1%) gases, conditions which also were associated with low diversity biofilms dominated by members of the acidophilic sulfur-oxidizer genus Acidithiobacillus. PMID:24842376

  2. Bacterial lipopolysaccharide induces osteoclast formation in RAW 264.7 macrophage cells

    International Nuclear Information System (INIS)

    Lipopolysaccharide (LPS) is a potent bone resorbing factor. The effect of LPS on osteoclast formation was examined by using murine RAW 264.7 macrophage cells. LPS-induced the formation of multinucleated giant cells (MGC) in RAW 264.7 cells 3 days after the exposure. MGCs were positive for tartrate-resistant acid phosphatase (TRAP) activity. Further, MGC formed resorption pits on calcium-phosphate thin film that is a substrate for osteoclasts. Therefore, LPS was suggested to induce osteoclast formation in RAW 264.7 cells. LPS-induced osteoclast formation was abolished by anti-tumor necrosis factor (TNF)-α antibody, but not antibodies to macrophage-colony stimulating factor (M-CSF) and receptor activator of nuclear factor (NF)-κB ligand (RANKL). TNF-α might play a critical role in LPS-induced osteoclast formation in RAW 264.7 cells. Inhibitors of NF-κB and stress activated protein kinase (SAPK/JNK) prevented the LPS-induced osteoclast formation. The detailed mechanism of LPS-induced osteoclast formation is discussed

  3. Finding immune gene expression differences induced by marine bacterial pathogens in the deep-sea hydrothermal vent mussel Bathymodiolus azoricus

    Directory of Open Access Journals (Sweden)

    R. Bettencourt

    2013-02-01

    Full Text Available The deep-sea hydrothermal vent mussel Bathymodiolus azoricus lives in a natural environment characterized by extreme conditions of hydrostatic pressure, temperature, pH, high concentrations of heavy metals, methane and hydrogen sulphide. The deep-sea vent biological systems represent thus the opportunity to study and provide new insights into the basic physiological principles that govern the defense mechanisms in vent animals and to understand how they cope with microbial infections. Hence, the importance of understanding this animal's innate defense mechanisms, by examining its differential immune gene expressions toward different pathogenic agents. In the present study, B. azoricus mussels were infected with single suspensions of marine bacterial pathogens, consisting of Vibrio splendidus, Vibrio alginolyticus, or Vibrio anguillarum, and a pool of these Vibrio strains. Flavobacterium suspensions were also used as an irrelevant bacterium. Gene expression analyses were carried out using gill samples from animals dissected at 12 h and 24 h post-infection times by means of quantitative-Polymerase Chain Reaction aimed at targeting several immune genes. We also performed SDS-PAGE protein analyses from the same gill tissues. We concluded that there are different levels of immune gene expression between the 12 h and 24 h exposure times to various bacterial suspensions. Our results from qPCR demonstrated a general pattern of gene expression, decreasing from 12 h over 24 h post-infection. Among the bacteria tested, Flavobacterium is the microorganism species inducing the highest gene expression level in 12 h post-infections animals. The 24 h infected animals revealed, however, greater gene expression levels, using V. splendidus as the infectious agent. The SDS-PAGE analysis also pointed at protein profile differences between 12 h and 24 h, particularly around a protein area, of 18 KDa molecular mass, where most dissimilarities were found. Multivariate

  4. Determination of fluoroquinolone antibiotics via ionic-liquid-based, salt-induced, dual microextraction in swine feed.

    Science.gov (United States)

    Wang, Huili; Gao, Ming; Gao, Jiajia; Yu, Nana; Huang, Hong; Yu, Qing; Wang, Xuedong

    2016-09-01

    In conventional microextraction procedures, the disperser (organic solvent or ionic liquid) is left in the aqueous phase and discarded after finishing the microextraction process. Because the disperser is water-soluble, it results in low extraction recovery for polar compounds. In this investigation, an ionic-liquid-based microextraction (ILBME) was integrated with salting-out assisted liquid-liquid microextraction (SALLME) to build an ionic-liquid-based, salt-induced, dual microextraction (ILSDME) for isolation of five fluoroquinolone antibiotics (FQs) with high polarity (log P, -1.0 to 1.0). The proposed ILSDME method incorporates a dual microextraction by converting the disperser in the ILBME to the extractor in the SALLME. Optimization of key factors was conducted by integrating single-factor experiments and central composite design. The optimized experimental parameters were 80 μL [C8MIM][PF6] as extractor, 505 μL acetone as disperser, pH = 2.0, 4.1 min extraction time, and 4.2 g of Na2SO4. Under optimized conditions, high ERs (90.6-103.2 %) and low LODs (0.07-0.61 μg kg(-1)) were determined for five FQs in swine feed. Experimental precision based on RSDs was 1.4-5.2 % for intra-day and 2.4-6.9 % for inter-day analyses. The combination of ILBME with SALLME increased FQ recoveries by 15-20 % as compared with SALLME, demonstrating that the ILSDME method can enhance extraction efficiency for polar compounds compared to single-step microextraction. Therefore, the ILSDME method developed in this study has wide application for pretreatment of moderately to highly polar pollutants in complex matrices. Graphical Abstract A dual microextraction was developed by integrating ionic-liquid-based microextraction with salting-out assisted liquid-liquid microextraction for isolation of five fluoroquinolone antibiotics (FQs) with high polarity (log P = -1.0 to 1.0). The principle of dual microextraction is based on converting the remaining disperser from

  5. Restricted feeding-induced sleep, activity, and body temperature changes in normal and preproghrelin-deficient mice

    Science.gov (United States)

    Behavioral and physiological rhythms can be entrained by daily restricted feeding (RF), indicating the existence of a food-entrainable oscillator (FEO). One manifestation of the presence of FEO is anticipatory activity to regularly scheduled feeding. In the present study, we tested if intact ghrelin...

  6. Anticonvulsant Effect of Time-Restricted Feeding in a Pilocarpine-Induced Seizure Model: Metabolic and Epigenetic Implications.

    Science.gov (United States)

    Landgrave-Gómez, Jorge; Mercado-Gómez, Octavio Fabián; Vázquez-García, Mario; Rodríguez-Molina, Víctor; Córdova-Dávalos, Laura; Arriaga-Ávila, Virginia; Miranda-Martínez, Alfredo; Guevara-Guzmán, Rosalinda

    2016-01-01

    A new generation of antiepileptic drugs has emerged; however, one-third of epilepsy patients do not properly respond to pharmacological treatments. The purpose of the present study was to investigate whether time-restricted feeding (TRF) has an anticonvulsant effect and whether this restrictive diet promotes changes in energy metabolism and epigenetic modifications in a pilocarpine-induced seizure model. To resolve our hypothesis, one group of rats had free access to food and water ad libitum (AL) and a second group underwent a TRF schedule. We used the lithium-pilocarpine model to induce status epilepticus (SE), and behavioral seizure monitoring was analyzed. Additionally, an electroencephalography (EEG) recording was performed to verify the effect of TRF on cortical electrical activity after a pilocarpine injection. For biochemical analysis, animals were sacrificed 24 h after SE and hippocampal homogenates were used to evaluate the proteins related to metabolism and chromatin structure. Our results showed that TRF had an anticonvulsant effect as measured by the prolonged latency of forelimb clonus seizure, a decrease in the seizure severity score and fewer animals reaching SE. Additionally, the power of the late phase EEG recordings in the AL group was significantly higher than the TRF group. Moreover, we found that TRF is capable of inducing alterations in signaling pathways that regulate energy metabolism, including an increase in the phosphorylation of AMP dependent kinase (AMPK) and a decrease in the phosphorylation of Akt kinase. Furthermore, we found that TRF was able to significantly increase the beta hydroxybutyrate (β-HB) concentration, an endogenous inhibitor of histone deacetylases (HDACs). Finally, we found a significant decrease in HDAC activity as well as an increase in acetylation on histone 3 (H3) in hippocampal homogenates from the TRF group. These findings suggest that alterations in energy metabolism and the increase in β-HB mediated by TRF

  7. Long-term high-fat-diet feeding induces skeletal muscle mitochondrial biogenesis in rats in a sex-dependent and muscle-type specific manner

    Directory of Open Access Journals (Sweden)

    Gómez-Pérez Yolanda

    2012-02-01

    Full Text Available Abstract Background Mitochondrial dysfunction is thought to play a crucial role in the etiology of insulin resistance, in which skeletal muscle is the main tissue contributor. Sex differences in skeletal muscle insulin and antioxidant responses to high-fat-diet (HFD feeding have been described. The aim of this study was to elucidate whether there is a sex dimorphism in the effects of HFD feeding on skeletal muscle mitochondrial biogenesis and on the adiponectin signaling pathway, as well as the influence of the muscle type (oxidative or glycolytic. Methods Gastrocnemius and soleus muscles of male and female Wistar rats of 2 months of age fed with a high-fat-diet (HFD or a low fat diet for 26 weeks were used. Mitochondrial biogenesis and oxidative damage markers, oxidative capacity and antioxidant defences were analyzed. Serum insulin sensitivity parameters and the levels of proteins involved in adiponectin signaling pathway were also determined. Results HFD feeding induced mitochondrial biogenesis in both sexes, but to a higher degree in male rats. Although HFD female rats showed greater antioxidant protection and maintained a better insulin sensitivity profile than their male counterparts, both sexes showed an impaired response to adiponectin, which was more evident in gastrocnemius muscle. Conclusions We conclude that HFD rats may induce skeletal muscle mitochondrial biogenesis as an attempt to compensate the deleterious consequences of adiponectin and insulin resistance on oxidative metabolism, and that the effects of HFD feeding are sex-dependent and muscle-type specific.

  8. Genetic analysis of the induced mutants of rice resistant to bacterial leaf blight

    International Nuclear Information System (INIS)

    Full text: Seeds of the rice cultivar 'Harebare', which is susceptible to bacterial leaf blight (BLB), were treated with thermal neutrons, gamma-rays, ethyleneimine and ethylmethane-sulfonate. In the M2, plants with better resistance to BLB were identified through inoculation at the seedling and the flag leaf stages with an isolate (T7174) of the Japanese differential race I. Several mutant lines resistant to BLB were selected through tests of the M3 or M4 lines derived from selected resistant M2 plants. The frequency of resistant mutants was significantly higher after the thermal neutron treatment than after treatments with other mutagens. Two mutants, which originated from the neutron treatment, showing a highly quantitative resistance to multiple BLB races were analysed for gene(s) for resistance. The resistance of one of them (M41) to the Japanese races I, II, III, IV, and V was found to be conditioned by a single recessive gene. Three other recessive genes for resistance are known, but their reaction to differential races is different. Therefore, this gene was thought to be new and was tentatively designated as xa-nm(t). The resistance of another mutant (M57) was found to be polygenically inherited. (author)

  9. Early Administration of Probiotics Alters Bacterial Colonization and Limits Diet-Induced Gut Dysfunction and Severity of Necrotizing Enterocolitis in Preterm Pigs

    DEFF Research Database (Denmark)

    Siggers, Richard H.; Siggers, Jayda; Boye, Mette;

    2008-01-01

    colonization, thereby reducing the susceptibility to formula-induced gut atrophy, dysfunction, and NEC. Caesarean-delivered preterm pigs were provided total parenteral nutrition (1.5 d) followed by enteral feeding (2d) with porcine colosstrum (COLOS; n= 5), formula (FORM; n = 9), or formula with probiotics...

  10. Feeding probiotic Lactobacillus rhamnosus (MTCC 5897) fermented milk to suckling mothers alleviates ovalbumin-induced allergic sensitisation in mice offspring.

    Science.gov (United States)

    Saliganti, Vamshi; Kapila, Rajeev; Sharma, Rohit; Kapila, Suman

    2015-10-28

    The neonatal period is often polarised to T helper (Th2) response at the time of birth, predisposing offspring to allergic disorders. Passive immunity through the mother's milk is critical for immune system development of newborns. Probiotics have been proposed to harmonise Th1/Th2 imbalance in allergic conditions in adults. In the present study, the anti-allergic effects of feeding probiotic Lactobacillus rhamnosus-fermented milk (PFM) either to dams during the suckling period or to their offspring after weaning individually or else in successive periods against ovalbumin (OVA)-induced allergy in newborns was analysed. After allergen sensitisation, physical symptoms of allergy, gut immune response, humoral immune response and cell-mediated response through interleukins were detected. Consumption of PFM by mothers and offspring showed a reduction (P<0·01) in physical allergic symptoms in newborns with an increase (P<0·01) in the numbers of goblet and IgA+ cells in the small intestine. Similarly, considerable (P<0·001) decreases in OVA-specific antibodies (IgE, IgG, IgG1) and ratios of IgE/IgG2a and IgG1/IgG2a in the sera of newborn mice were recorded. A decrease in IL-4 and an increase in interferon-γ levels further confirmed the shift from Th2 to Th1 pathway in PFM-fed mice. It is logical to conclude that the timing of PFM intervention in alleviating allergic symptoms is critical, which was found to be most effective when mothers were fed during the suckling period. PMID:26330132

  11. Antidiabetic and antioxidant effects of catalpol extracted from Rehmannia glutinosa (Di Huang) on rat diabetes induced by streptozotocin and high-fat, high-sugar feed

    OpenAIRE

    Zhu, HuiFeng; Wang, Yuan; Liu, Zhiqiang; Wang, Jinghuan; Wan, Dong; Feng, Shan; Yang, Xian; Tao WANG

    2016-01-01

    Background Diabetes, associated with hyperlipidemia and oxidative stress, would lead to an increased production of reactive oxygen species. Rehmannia glutinosa (Di Huang) is widely used to nourish yin, invigorate the kidney (shen), and treat xiao ke (a diabetes-like syndrome in Chinese medicine). This study aims to investigate the antidiabetic and antioxidant effects of catalpol from R. glutinosa on rat diabetes induced by streptozotocin (STZ) and high-fat, high-sugar feed. Methods Rats (eigh...

  12. Use of in vivo-induced antigen technology (IVIAT for the identification of Streptococcus suis serotype 2 in vivo-induced bacterial protein antigens

    Directory of Open Access Journals (Sweden)

    Lu Chengping

    2009-09-01

    Full Text Available Abstract Background Streptococcus suis serotype 2 (SS2 is a zoonotic agent that causes death and disease in both humans and swine. A better understanding of SS2-host molecular interactions is crucial for understanding SS2 pathogenesis and immunology. Conventional genetic and biochemical approaches used to study SS2 virulence factors are unable to take into account the complex and dynamic environmental stimuli associated with the infection process. In this study, in vivo-induced antigen technology (IVIAT, an immunoscreening technique, was used to identify the immunogenic bacterial proteins that are induced or upregulated in vivo during SS2 infection. Results Convalescent-phase sera from pigs infected with SS2 were pooled, adsorbed against in vitro antigens, and used to screen SS2 genomic expression libraries. Upon analysis of the identified proteins, we were able to assign a putative function to 40 of the 48 proteins. These included proteins implicated in cell envelope structure, regulation, molecule synthesis, substance and energy metabolism, transport, translation, and those with unknown functions. The in vivo-induced changes in the expression of 10 of these 40 genes were measured using real-time reverse transcription (RT-PCR, revealing that the expression of 6 of the 10 genes was upregulated in the in vivo condition. The strain distribution of these 10 genes was analyzed by PCR, and they were found in the most virulent SS2 strains. In addition, protein sequence alignments of the newly identified proteins demonstrate that three are putative virulence-associated proteins. Conclusion Collectively, our results suggest that these in vivo-induced or upregulated genes may contribute to SS2 disease development. We hypothesize that the identification of factors specifically induced or upregulated during SS2 infection will aid in our understanding of SS2 pathogenesis and may contribute to the control SS2 outbreaks. In addition, the proteins identified

  13. Modulation of Inducible Nitric Oxide Synthase Expression by the Attaching and Effacing Bacterial Pathogen Citrobacter rodentium in Infected Mice

    Science.gov (United States)

    Vallance, Bruce A.; Deng, Wanyin; De Grado, Myriam; Chan, Crystal; Jacobson, Kevan; Finlay, B. Brett

    2002-01-01

    Citrobacter rodentium belongs to the attaching and effacing family of enteric bacterial pathogens that includes both enteropathogenic and enterohemorrhagic Escherichia coli. These bacteria infect their hosts by colonizing the intestinal mucosal surface and intimately attaching to underlying epithelial cells. The abilities of these pathogens to exploit the cytoskeleton and signaling pathways of host cells are well documented, but their interactions with the host's antimicrobial defenses, such as inducible nitric oxide synthase (iNOS), are poorly understood. To address this issue, we infected mice with C. rodentium and found that iNOS mRNA expression in the colon significantly increased during infection. Immunostaining identified epithelial cells as the major source for immunoreactive iNOS. Finding that nitric oxide (NO) donors were bacteriostatic for C. rodentium in vitro, we examined whether iNOS expression contributed to host defense by infecting iNOS-deficient mice. Loss of iNOS expression caused a small but significant delay in bacterial clearance without affecting tissue pathology. Finally, immunofluorescence staining was used to determine if iNOS expression was localized to infected cells by staining for the C. rodentium virulence factor, translocated intimin receptor (Tir), as well as iNOS. Interestingly, while more than 85% of uninfected epithelial cells expressed iNOS, fewer than 15% of infected (Tir-positive) cells expressed detectable iNOS. These results demonstrate that both iNOS and intestinal epithelial cells play an active role in host defense during C. rodentium infection. However, the selective expression of iNOS by uninfected but not infected cells suggests that this pathogen has developed mechanisms to locally limit its exposure to host-derived NO. PMID:12379723

  14. Antibiotic-induced dysbiosis alters host-bacterial interactions and leads to colonic sensory and motor changes in mice.

    Science.gov (United States)

    Aguilera, M; Cerdà-Cuéllar, M; Martínez, V

    2015-01-01

    Alterations in the composition of the commensal microbiota (dysbiosis) seem to be a pathogenic component of functional gastrointestinal disorders, mainly irritable bowel syndrome (IBS), and might participate in the secretomotor and sensory alterations observed in these patients.We determined if a state antibiotics-induced intestinal dysbiosis is able to modify colonic pain-related and motor responses and characterized the neuro-immune mechanisms implicated in mice. A 2-week antibiotics treatment induced a colonic dysbiosis (increments in Bacteroides spp, Clostridium coccoides and Lactobacillus spp and reduction in Bifidobacterium spp). Bacterial adherence was not affected. Dysbiosis was associated with increased levels of secretory-IgA, up-regulation of the antimicrobial lectin RegIIIγ, and toll-like receptors (TLR) 4 and 7 and down-regulation of the antimicrobial-peptide Resistin-Like Molecule-β and TLR5. Dysbiotic mice showed less goblet cells, without changes in the thickness of the mucus layer. Neither macroscopical nor microscopical signs of inflammation were observed. In dysbiotic mice, expression of the cannabinoid receptor 2 was up-regulated, while the cannabinoid 1 and the mu-opioid receptors were down-regulated. In antibiotic-treated mice, visceral pain-related responses elicited by intraperitoneal acetic acid or intracolonic capsaicin were significantly attenuated. Colonic contractility was enhanced during dysbiosis. Intestinal dysbiosis induce changes in the innate intestinal immune system and modulate the expression of pain-related sensory systems, an effect associated with a reduction in visceral pain-related responses. Commensal microbiota modulates gut neuro-immune sensory systems, leading to functional changes, at least as it relates to viscerosensitivity. Similar mechanisms might explain the beneficial effects of antibiotics or certain probiotics in the treatment of IBS. PMID:25531553

  15. Natural Killer Cells and Helicobacter pylori Infection: Bacterial Antigens and Interleukin-12 Act Synergistically To Induce Gamma Interferon Production

    Science.gov (United States)

    Yun, Cheol H.; Lundgren, Anna; Azem, Josef; Sjöling, Åsa; Holmgren, Jan; Svennerholm, Ann-Mari; Lundin, B. Samuel

    2005-01-01

    Helicobacter pylori is known to induce a local immune response, which is characterized by activation of lymphocytes and the production of IFN-γ in the stomach mucosa. Since not only T cells, but also natural killer (NK) cells, are potent producers of gamma interferon (IFN-γ), we investigated whether NK cells play a role in the immune response to H. pylori infection. Our results showed that NK cells were present in both the gastric and duodenal mucosae but that H. pylori infection did not affect the infiltration of NK cells into the gastrointestinal area. Furthermore, we could show that NK cells could be activated directly by H. pylori antigens, as H. pylori bacteria, as well as lysate from H. pylori, induced the secretion of IFN-γ by NK cells. NK cells were also activated without direct contact when separated from the bacteria by an epithelial cell layer, indicating that the activation of NK cells by H. pylori can also occur in vivo, in the infected stomach mucosa. Moreover, the production of IFN-γ by NK cells was greatly enhanced when a small amount of interleukin-12 (IL-12) was added, and this synergistic effect was associated with increased expression of the IL-12 receptor β2. It was further evident that bacterial lysate alone was sufficient to induce the activation of cytotoxicity-related molecules. In conclusion, we demonstrated that NK cells are present in the gastroduodenal mucosa of humans and that NK cells produce high levels of IFN-γ when stimulated with a combination of H. pylori antigen and IL-12. We propose that NK cells play an active role in the local immune response to H. pylori infection. PMID:15731046

  16. A Feeding Induced Switch from a Variable to a Homogenous State of the Earthworm Gut Microbiota within a Host Population

    OpenAIRE

    Rudi, Knut; Ødegård, Kristin; Løkken, Tine Therese; Wilson, Robert

    2009-01-01

    Background The distribution pattern of the earthworm gut microbiota at the host population level is of fundamental importance to understand host-microbiota interactions. Our current understanding of these interactions is very limited. Since feeding represents a main perturbation of the gut microbiota, we determined the effect of a single dose of feed on the microbiota associated with an earthworm population in a simulated microenvironment. Methodology Earthworms were sampled 0, 1 and 7 days a...

  17. Modeling of induced mutation process in bacterial cells with defects in excision repair system

    International Nuclear Information System (INIS)

    A mathematical model of the UV-induced mutation process in Escherichia coli bacteria cells with defects in uvrA and polA genes has been developed. The model describes in detail the reaction kinetics for excision repair system. The number of mismatches as results from translesion-synthesis is calculated for both wild-type and mutant cells. An effect of temporal modulation for amount of single-stranded DNA during post-replication repair is predicted. A comparison of repair system efficiency is conducted

  18. Enhanced Expression of Aquaporin-9 in Rat Brain Edema Induced by Bacterial Lipopolysaccharides

    Institute of Scientific and Technical Information of China (English)

    Huaili WANG; Runming JIN; Peichao TIAN; Zhihong ZHUO

    2009-01-01

    To investigate the role of AQP9 in brain edema,the expression of AQP9 in an infectious rat brain edema model induced by the injection of lipopolysaccharide (LPS) was examined.Immunohistochemistry and reverse transcription-polymerase chain reaction (RT-PCR) analysis demonstrated that the expressions of AQP9 mRNA and protein at all observed intervals were significantly increased in LPS-treated animals in comparison with the control animals.Time-course analysis showed that the first signs of blood-brain barrier disruption and the increase of brain water content in LPS-treated animals were evident 6 h after LPS injection,with maximum value appearing at 12 h,which coincided with the expression profiles of AQP9 mRNA and protein in LPS-treated animals.The further correlation analysis revealed strong positive correlations among the brain water content,the disruption of the blood-brain barrier and the enhanced expressions of AQP9 mRNA and protein in LPS-treated animals.These results suggested that the regulation of AQP9 expression may play important roles in water movement and in brain metabolic homeostasis associated with the pathophysiology of brain edema induced by LPS injection.

  19. Bacterial-induced cell reprogramming to stem cell-like cells: new premise in host-pathogen interactions

    OpenAIRE

    Hess, Samuel; Rambukkana, Anura

    2014-01-01

    Bacterial pathogens employ a myriad of strategies to alter host tissue cell functions for bacterial advantage during infection. Recent advances revealed a fusion of infection biology with stem cell biology by demonstrating developmental reprogramming of lineage committed host glial cells to progenitor/stem cell-like cells by an intracellular bacterial pathogen Mycobacterium leprae. Acquisition of migratory and immunomodulatory properties of such reprogrammed cells provides an added advantage ...

  20. Morphine Induces Bacterial Translocation in Mice by Compromising Intestinal Barrier Function in a TLR-Dependent Manner

    OpenAIRE

    Meng, Jingjing; Yu, Haidong; Ma, Jing; Wang, Jinghua; Banerjee, Santanu; Charboneau, Rick; Barke, Roderick A.; Roy, Sabita

    2013-01-01

    Opiates are among the most prescribed drugs for pain management. However, morphine use or abuse results in significant gut bacterial translocation and predisposes patients to serious infections with gut origin. The mechanism underlying this defect is still unknown. In this report, we investigated the mechanisms underlying compromised gut immune function and bacterial translocation following morphine treatment. We demonstrate significant bacterial translocation to mesenteric lymph node (MLN) a...

  1. Activity changes in jaw motor neurons induced by egg-laying hormone contribute to the feeding suppression during egg-laying behavior in Aplysia kurodai.

    Science.gov (United States)

    Narusuye, Kenji; Hamaguchi, Aya; Nagahama, Tatsumi

    2013-01-01

    Egg-laying behavior in Aplysia is accompanied by behavioral changes such as feeding suppression. We investigated the effects of the egg-laying hormone (ELH) on food intake, the activity patterns of jaw muscles, and the activity of buccal neurons (multi-action neuron [MA1] and jaw-closing motor neuron [JC2]), which are elements of the feeding neural circuits controlling jaw movements in Aplysia kurodai. Injection of ELH into the body cavity inhibited the intake of seaweed. After ELH application, the rhythmic activity of jaw muscles that was induced by preferred taste stimulation elicited fewer ingestion-like responses and increased the number of rejection-like responses. ELH applied to the buccal ganglia increased the firing activity of JC2 during spontaneous rhythmic responses and during the rhythmic feeding-like responses that were evoked by electrical stimulation of the esophageal nerves. In the 2 types of rhythmic responses, the Dn (normalized value of the delay time of JC2 firing onset) decreased after ELH application as compared with the control. Furthermore, ELH decreased the size of MA1-induced inhibitory postsynaptic currents in JC2. These results suggest that ELH changes the buccal motor program from ingestion to rejection on the basis of our previous results, and may contribute to a decrease in food intake during egg laying. PMID:23501243

  2. Are bacterial volatile compounds poisonous odors to a fungal pathogen Botrytis cinerea, alarm signals to Arabidopsis seedlings for eliciting induced resistance, or both?

    Directory of Open Access Journals (Sweden)

    Choong-Min eRyu

    2016-02-01

    Full Text Available Biological control (biocontrol agents act on plants via numerous mechanisms, and can be used to protect plants from pathogens. Biocontrol agents can act directly as pathogen antagonists or competitors or indirectly to promote plant induced systemic resistance (ISR. Whether a biocontrol agent acts directly or indirectly depends on the specific strain and the pathosystem type. We reported previously that bacterial volatile organic compounds (VOCs are determinants for eliciting plant ISR. Emerging data suggest that bacterial VOCs also can directly inhibit fungal and plant growth. The aim of the current study was to differentiate direct and indirect mechanisms of bacterial VOC effects against Botrytis cinerea infection of Arabidopsis. Volatile emissions from Bacillus subtilis GB03 successfully protected Arabidopsis seedlings against B. cinerea. First, we investigated the direct effects of bacterial VOCs on symptom development and different phenological stages of B. cinerea including spore germination, mycelial attachment to the leaf surface, mycelial growth, and sporulation in vitro and in planta. Volatile emissions inhibited hyphal growth in a dose-dependent manner in vitro, and interfered with fungal attachment on the hydrophobic leaf surface. Second, the optimized bacterial concentration that did not directly inhibit fungal growth successfully protected Arabidopsis from fungal infection, which indicates that bacterial VOC-elicited plant ISR has a more important role in biocontrol than direct inhibition of fungal growth on Arabidopsis. We performed qRT-PCR to investigate the priming of the defense-related genes PR1, PDF1.2, and ChiB at 0, 12, 24, and 36 hours post-infection and 14 days after the start of plant exposure to bacterial VOCs. The results indicate that bacterial VOCs potentiate expression of PR1 and PDF1.2 but not ChiB, which stimulates SA- and JA-dependent signaling pathways in plant ISR and protects plants against pathogen

  3. Are Bacterial Volatile Compounds Poisonous Odors to a Fungal Pathogen Botrytis cinerea, Alarm Signals to Arabidopsis Seedlings for Eliciting Induced Resistance, or Both?

    Science.gov (United States)

    Sharifi, Rouhallah; Ryu, Choong-Min

    2016-01-01

    Biological control (biocontrol) agents act on plants via numerous mechanisms, and can be used to protect plants from pathogens. Biocontrol agents can act directly as pathogen antagonists or competitors or indirectly to promote plant induced systemic resistance (ISR). Whether a biocontrol agent acts directly or indirectly depends on the specific strain and the pathosystem type. We reported previously that bacterial volatile organic compounds (VOCs) are determinants for eliciting plant ISR. Emerging data suggest that bacterial VOCs also can directly inhibit fungal and plant growth. The aim of the current study was to differentiate direct and indirect mechanisms of bacterial VOC effects against Botrytis cinerea infection of Arabidopsis. Volatile emissions from Bacillus subtilis GB03 successfully protected Arabidopsis seedlings against B. cinerea. First, we investigated the direct effects of bacterial VOCs on symptom development and different phenological stages of B. cinerea including spore germination, mycelial attachment to the leaf surface, mycelial growth, and sporulation in vitro and in planta. Volatile emissions inhibited hyphal growth in a dose-dependent manner in vitro, and interfered with fungal attachment on the hydrophobic leaf surface. Second, the optimized bacterial concentration that did not directly inhibit fungal growth successfully protected Arabidopsis from fungal infection, which indicates that bacterial VOC-elicited plant ISR has a more important role in biocontrol than direct inhibition of fungal growth on Arabidopsis. We performed qRT-PCR to investigate the priming of the defense-related genes PR1, PDF1.2, and ChiB at 0, 12, 24, and 36 h post-infection and 14 days after the start of plant exposure to bacterial VOCs. The results indicate that bacterial VOCs potentiate expression of PR1 and PDF1.2 but not ChiB, which stimulates SA- and JA-dependent signaling pathways in plant ISR and protects plants against pathogen colonization. This study

  4. Effects of microbially induced transformations and shift in bacterial community on arsenic mobility in arsenic-rich deep aquifer sediments.

    Science.gov (United States)

    Das, Suvendu; Liu, Chia-Chuan; Jean, Jiin-Shuh; Lee, Chuan-Chun; Yang, Huai-Jen

    2016-06-01

    Elevated concentration of arsenic (As) prevailed in deep aquifers of Chianan Plain, Taiwan. Arsenic release in relation to microbially induced transformations and shift in bacterial communities in deep aquifer sediments of Budai, southwestern Taiwan were investigated using microcosm experiments and substrate amendments over 90 days of anaerobic incubation. The results revealed that As reduction was independent of Fe reduction and a modest rate of sedimentary As release into aqueous phase occurred at the expense of the native organic carbon. Addition of lactate resulted in a parallel increase in As(III) (3.7-fold), Fe(II) (6.2-fold) and Mn (3.5 fold) in aqueous phase compared to un-amended slurries and the enrichment of sequences related to mostly Bacillus, Flavisolibacter, and Geobacter spp, suggesting the important role of these bacteria in As enrichment through reductive dissolution of As-bearing Fe and Mn minerals. The increase in phosphate-extractable As in solid phase with concomitant rise in As in aqueous phase over the course of incubation further attested to the importance of reductive dissolution in promoting As release. Furthermore, the increase in arrA gene abundance with addition of labile carbon suggests that dissimilatory As reduction also may contribute to As enrichment in the water of the deep aquifer of Budai. PMID:26897570

  5. Ambient UV-B exposure reduces the binding of ofloxacin with bacterial DNA gyrase and induces DNA damage mediated apoptosis.

    Science.gov (United States)

    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. PMID:26812543

  6. Selective Protection of an ARF1-GTP Signaling Axis by a Bacterial Scaffold Induces Bidirectional Trafficking Arrest

    Directory of Open Access Journals (Sweden)

    Andrey S. Selyunin

    2014-03-01

    Full Text Available Bidirectional vesicular transport between the endoplasmic reticulum (ER and Golgi is mediated largely by ARF and Rab GTPases, which orchestrate vesicle fission and fusion, respectively. How their activities are coordinated in order to define the successive steps of the secretory pathway and preserve traffic directionality is not well understood in part due to the scarcity of molecular tools that simultaneously target ARF and Rab signaling. Here, we take advantage of the unique scaffolding properties of E. coli secreted protein G (EspG to describe the critical role of ARF1/Rab1 spatiotemporal coordination in vesicular transport at the ER-Golgi intermediate compartment. Structural modeling and cellular studies show that EspG induces bidirectional traffic arrest by tethering vesicles through select ARF1-GTP/effector complexes and local inactivation of Rab1. The mechanistic insights presented here establish the effectiveness of a small bacterial catalytic scaffold for studying complex processes and reveal an alternative mechanism of immune regulation by an important human pathogen.

  7. Endocytosis-inducer adhesins produced by enteropathogenic serogroups of Escherichia coli participate on bacterial attachment to infant enterocytes

    Directory of Open Access Journals (Sweden)

    João Ramos Costa Andrade

    1987-03-01

    Full Text Available Enteropathogenic E. coli (EPEC infection of Hep-2 cells preoceeds through bacterial attachment to cell surface and internalization of adhered bacteria. EPEC attachment is a prerequisite for cell infection and is mediated by adhesins that recognize carbohydrate-containing receptors on cell membrane. Such endocytosis-inducer adhesins (EIA also promote EPEC binding to infant enterocytes, suggesting that EIA may have an important role on EPEC gastroenteritis.A infecção de células Hep-2 por E. coli enteropatogênicas (ECEP implica na aderência bacteriana e posterior interiorização dos microrganismos aderidos por um mecanismo de endocitose. A aderência das ECEP é pré-requisito para a infecção e é mediada por adesinas que reconhecem receptores inibidos por certas oses na membrana celular. Tais "adesinas indutoras da endocitose" (AIE também promovem a ligação bacteriana a enterócitos obtidos do intestino delgado de lactente, sugerindo que as AIE possam desempenhar algum papel nas diarréias causadas por ECEP.

  8. Bacterial endotoxin-induced gene expression in the choroid plexus and paraventricular and supraoptic hypothalamic nuclei of the sheep.

    Science.gov (United States)

    Vellucci, S V; Parrott, R F

    1996-12-31

    The febrile and neuroendocrine responses to circulating endotoxin are effected, at least in part, by a central action of prostaglandins with interleukins serving as intermediaries. Data from rodents suggest that prostaglandin and interleukin (IL-1 beta) synthesis in response to endotoxin challenge may occur within the circumventricular organs of the brain, especially the choroid plexus; the present study investigated this possibility using the sheep as an experimental model. A pyretic dose of bacterial endotoxin (40 micrograms lipopolysaccharide) was given intravenously to sheep (n = 5) and the effect on gene expression in the choroid plexus after a 40 min interval was compared with that observed in vehicle-treated animals (n = 5) using in situ hybridisation histochemistry. Evidence of activational and synthetic events following endotoxin administration was provided by significant increases in c-fos (P gene expression. The results showed that c-fos mRNA increased in the paraventricular (P gene expression although oxytocin mRNA was enhanced throughout the paraventricular nucleus (P sheep to immunological challenge: (2) endotoxin-induced changes in gene expression in the ovine hypothalamus similar in those caused by other stressors: and (3) possible changes in oxytocin synthesis concomitant with fever in the sheep. PMID:9037517

  9. Bacterial antigen induced release of soluble vascular endothelial growth factor (VEGF) and VEGFR1 before and after surgery

    DEFF Research Database (Denmark)

    Svendsen, Mads N; Lykke, J; Werther, Kim;

    2005-01-01

    -induced release of sVEGF and sVEGFR1 from whole blood in vitro. MATERIAL AND METHODS: Sixty-one patients with abdominal diseases undergoing five different surgical procedures were included in the study. Blood samples were drawn from patients before and after the operation. White blood cells and platelets were......OBJECTIVE: The influence of surgery on release of soluble vascular endothelial growth factor (sVEGF) and the soluble inhibitory receptor (sVEGFR1) is unknown. The effect of major and minor surgery on variations in sVEGF and sVEGFR1 concentrations in vivo was studied, and on bacterial antigen...... counted, and plasma sVEGF and sVEGFR1 were determined. Whole blood from each blood sample was stimulated in vitro with bacteria-derived antigens (lipopolysaccharides or protein A) and sVEGF and sVEGFR1 levels were subsequently determined in the supernatants. RESULTS: Neither sVEGF nor sVEGFR1...

  10. Role of Bacterial Exopolysaccharides as Agents in Counteracting Immune Disorders Induced by Herpes Virus

    Directory of Open Access Journals (Sweden)

    Concetta Gugliandolo

    2015-08-01

    Full Text Available Extreme marine environments, such as the submarine shallow vents of the Eolian Islands (Italy, offer an almost unexplored source of microorganisms producing unexploited and promising biomolecules for pharmaceutical applications. Thermophilic and thermotolerant bacilli isolated from Eolian vents are able to produce exopolysaccharides (EPSs with antiviral and immunomodulatory effects against Herpes simplex virus type 2 (HSV-2. HSV-2 is responsible for the most common and continuously increasing viral infections in humans. Due to the appearance of resistance to the available treatments, new biomolecules exhibiting different mechanisms of action could provide novel agents for treating viral infections. The EPSs hinder the HSV-2 replication in human peripheral blood mononuclear cells (PBMC but not in WISH (Wistar Institute Susan Hayflic cells line, indicating that cell-mediated immunity was involved in the antiviral activity. High levels of Th1-type cytokines were detected in PBMC treated with all EPSs, while Th2-type cytokines were not induced. These EPSs are water soluble exopolymers able to stimulate the immune response and thus contribute to the antiviral immune defense, acting as immunomodulators. As stimulants of Th1 cell-mediated immunity, they could lead to the development of novel drugs as alternative in the treatment of herpes virus infections, as well as in immunocompromised host.

  11. Detection of SOS response induced by γ-irradiation using umu-test, a bacterial short-term test

    International Nuclear Information System (INIS)

    The genotoxic effects of γ-irradiation were examined using the umu-test, a bacterial short-term test for the detection of genotoxic agents. The principle of the umu-test is based on the induction of the SOS function against DNA damage in Salmonella typhimurium (TA1535/pSK1002 and TA4107/pSK1002); the test measures colorimetrically the expression of umu gene involved directly in SOS mutagenesis. The strains, irradiated aerobically in phosphate buffer, showed a phasic response to γ-irradiation during their growth cycles. The SOS response was the highest level in the lag phase, suggesting that the irradiated lag-phase cells are very sensitive to γ-irradiation and survive via mutation. The hydroxyl radical scavengers, dimethylsulfoxide (DMSO) and ethanol, decreased the SOS response in a dose-related manner. DMSO (0.5 M) added into the aerobic cell suspension decreased the SOS response by about 50% in TA1535/pSK1002 and by about 40% in TA4107/pSK1002; the similar proportion was shown in the anaerobic cell suspension containing the scavenger. In addition, the SOS response induced under the aerobic condition was reduced by about 60% in the anaerobic cell suspension containing 0.5 M DMSO. The observations suggest that the SOS response is induced similarly by the direct excitation and the indirect effect by hydroxyl radicals generated during the γ-irradiation of aqueous solution. These results obtained using umu-test were consistent with the phasic response and the irradiation effect reported previously using the survival and DNA strand breaks of bacteria. (author)

  12. Detection of bacterial infection of agave plants by laser-induced fluorescence

    Science.gov (United States)

    Cervantes-Martinez, Jesus; Flores-Hernandez, Ricardo; Rodriguez-Garay, Benjamin; Santacruz-Ruvalcaba, Fernando

    2002-05-01

    Greenhouse-grown plants of Agave tequilana Weber var. azul were inoculated with Erwinia carotovora, the causal agent of stem soft rot. We investigated the laser-induced fluorescence (LIF) of agave plants to determine whether LIF can be used as a noninvasive sensing tool for pathological studies. The LIF technique was also investigated as a means of detecting the effect of the polyamine biosynthesis inhibitor beta-hydroxyethylhydrazine as a bactericide against the pathogenic bacterium Erwinia carotovora. A He-Ne laser at 632.8 nm was used as the excitation source, and in vivo fluorescence emission spectra were recorded in the 660-790-range. Fluorescence maxima were at 690 and 740 nm. The infected plants that were untreated with the bactericide showed a definite increase in fluorescence intensity at both maxima within the first three days after infection. Beginning on the fifth day, a steady decrease in fluorescence intensity was observed, with a greater effect at 740 than at 690 nm. After 30 days there was no fluorescence. The infected plants that had been treated with the bactericide showed no significant change in fluorescence compared with that of the uninfected plants. The ratio of fluorescence intensities was determined to be F 690 nm/F 740 nm for all treatments. These studies indicate that LIF measurements of agave plants may be used for the early detection of certain types of disease and for determining the effect of a bactericide on bacteria. The results also showed that fluorescence intensity ratios can be used as a reliable indicator of the progress of disease.

  13. Transcriptomic analysis by RNA sequencing reveals that hepatic interferon-induced genes may be associated with feed efficiency in beef heifers.

    Science.gov (United States)

    Paradis, F; Yue, S; Grant, J R; Stothard, P; Basarab, J A; Fitzsimmons, C

    2015-07-01

    In beef cattle, production feedstuffs are the largest variable input cost. Beef cattle also have a large carbon footprint, raising concern about their environmental impact. Unfortunately, only a small proportion of dietary energy is directed toward protein deposition and muscle growth whereas the majority supports body maintenance. Improving feed efficiency would, therefore, have important consequences on productivity, profitability, and sustainability of the beef industry. Various measures of feed efficiency have been proposed to improve feed utilization, and currently, residual feed intake (RFI) is gaining popularity. However, the cost associated with measuring RFI and the limited knowledge of the biology underlying improved feed efficiency make its adoption prohibitive. Identifying molecular mechanisms explaining divergence in RFI in beef cattle would lead to the development of early detection methods for the selection of more efficient breeding stock. The objective of this study was to identify hepatic markers of metabolic feed efficiency in replacement beef heifers. A group of 87 heifers were tested for RFI adjusted for off-test backfat thickness (RFIfat). Preprandial liver biopsies were collected from 10 high- and 10 low-RFIfat heifers (7 Hereford–Aberdeen Angus and 3 Charolais–Red Angus–Main Anjou per group) and gene expression analysis was performed using RNA sequencing and quantitative real-time PCR. The heifers used in this study differed in RFIfat averaging 0.438 vs. –0.584 kg DM/d in high- and low-RFIfat groups, respectively. As expected, DMI was correlated with RFIfat and ADG did not differ between high- and low-RFIfat heifers. Through a combination of whole transcriptome and candidate gene analyses, we identified differentially expressed genes involved in inflammatory processes including hemoglobin β (HBB), myxovirus resistance 1 interferon-inducible protein p78 (MX1), ISG15 ubiquitin-like modifier (ISG15), hect domain and RLD 6 (HERC6), and

  14. Induced drought tolerance through wild and mutant bacterial strain Pseudomonas simiae in mung bean (Vigna radiata L.).

    Science.gov (United States)

    Kumari, Sarita; Vaishnav, Anukool; Jain, Shekhar; Varma, Ajit; Choudhary, Devendra Kumar

    2016-01-01

    The present study focused on the overproducing mutant of a plant growth promoting rhizobacterium (PGPR) Pseudomonas simiae strain AU (MTCC-12057) for significant drought tolerance in mung bean plants. Five mutants namely AU-M1, AU-M2, AU-M3, AU-M4 and AU-M5 were made after treatment of wild type strain with N-methyl-N-nitro-N-nitrosoguanidine. Mutant strain AU-M4 was recorded for enhanced ACC deaminase (ACC-D) activity, indole acetic acid (IAA) production and inorganic phosphate (Pi) solubilization compared to wild strain and other four mutant strains under drought condition. AU-M4 showed higher phosphate solubilization index (8.17) together with higher ACC-D activity (98 nmol/mg/h) and IAA concentration (69.35 µg/ml) compared with the wild type P. simiae strain AU ACC-D activity (79 nmol/mg/h) and IAA concentration (38.98 µg/ml) respectively. In this report, we investigated the effect of both wild and mutant type bacterial strain on mung bean plants under drought stress. Results showed that mutant AU-M4 and wild type strain AU inoculated plants exhibited superior tolerance against drought stress, as shown by their enhanced plant biomass (fresh weight), higher water content, higher proline accumulation and lower osmotic stress injury. Mutant AU-M4 and wild strain AU inoculated plants reduced the ethylene level by 59 and 45% respectively, compared to the control under stress condition. Furthermore, bacterial inoculated plants showed enhanced induced systemic drought tolerance by reducing stomata size and net photosynthesis resulting higher water content in mung bean plants that may help in survival of plants during drought condition. To mitigate the effects of drought stress, use of PGPR will be needed to ensure sufficient production of food from crop plants. Taking current leads available, concerted future research is needed in this area, particularly on field evaluation with application of potential microorganisms. PMID:26712619

  15. The chemically inducible expression of Erwinia amylovora bacterial effectors EopB1 and HopCEa in apple

    Science.gov (United States)

    Erwinia amylovora, the causal agent of fire blight disease, utilizes a type three secretion system to deliver effector proteins into plant host cells. To investigate the role of individual bacterial effector proteins, we have engineered an apple host that transgenically expresses the bacterial effe...

  16. Prospecting for new bacterial metabolites: a glossary of approaches for inducing, activating and upregulating the biosynthesis of bacterial cryptic or silent natural products.

    Science.gov (United States)

    Zarins-Tutt, Joseph Scott; Barberi, Tania Triscari; Gao, Hong; Mearns-Spragg, Andrew; Zhang, Lixin; Newman, David J; Goss, Rebecca Jane Miriam

    2016-01-01

    Covering: up to 2015. Over the centuries, microbial secondary metabolites have played a central role in the treatment of human diseases and have revolutionised the pharmaceutical industry. With the increasing number of sequenced microbial genomes revealing a plethora of novel biosynthetic genes, natural product drug discovery is entering an exciting second golden age. Here, we provide a concise overview as an introductory guide to the main methods employed to unlock or up-regulate these so called 'cryptic', 'silent' and 'orphan' gene clusters, and increase the production of the encoded natural product. With a predominant focus on bacterial natural products we will discuss the importance of the bioinformatics approach for genome mining, the use of first different and simple culturing techniques and then the application of genetic engineering to unlock the microbial treasure trove. PMID:26538321

  17. Are Bacterial Volatile Compounds Poisonous Odors to a Fungal Pathogen Botrytis cinerea, Alarm Signals to Arabidopsis Seedlings for Eliciting Induced Resistance, or Both?

    OpenAIRE

    Sharifi, Rouhallah; Ryu, Choong-Min

    2016-01-01

    Biological control (biocontrol) agents act on plants via numerous mechanisms, and can be used to protect plants from pathogens. Biocontrol agents can act directly as pathogen antagonists or competitors or indirectly to promote plant induced systemic resistance (ISR). Whether a biocontrol agent acts directly or indirectly depends on the specific strain and the pathosystem type. We reported previously that bacterial volatile organic compounds (VOCs) are determinants for eliciting plant ISR. Eme...

  18. The neurotoxic effect of clindamycin - induced gut bacterial imbalance and orally administered propionic acid on DNA damage assessed by the comet assay: protective potency of carnosine and carnitine

    OpenAIRE

    El-Ansary, Afaf; Shaker, Ghada H; El-Gezeery, Amina R; Al-Ayadhi, Laila

    2013-01-01

    Background Comet assay is a quick method for assessing DNA damage in individual cells. It allows the detection of single and double DNA strand breaks, which represent the direct effect of some damaging agents. This study uses standard comet quantification models to compare the neurotoxic effect of orally administered propionic acid (PA) to that produced as a metabolite of bacterial overgrowth induced by clindamycin. Additionally, the protective effect of carnosine and carnitine as natural die...

  19. Xenin-induced feeding suppression is not mediated through the activation of central extracellular signal-regulated kinase signaling in mice.

    Science.gov (United States)

    Kim, Eun Ran; Lew, Pei San; Spirkina, Alexandra; Mizuno, Tooru M

    2016-10-01

    Xenin is a gut hormone that reduces food intake by partly acting through the hypothalamus via neurotensin receptor 1 (Ntsr1). However, specific signaling pathways that mediate xenin-induced feeding suppression are not fully understood. Activation of Ntsr1 leads to the activation of the extracellular signal-regulated kinase (ERK). Hypothalamic ERK participates in the regulation of food intake by mediating the effect of hormonal signals. Therefore, we hypothesized that the anorectic effect of xenin is mediated by hypothalamic ERK signaling. To address this hypothesis, we compared levels of phosphorylation of ERK1/2 (pERK1/2) in the hypothalamus of both control and xenin-treated mice. The effect of xenin on ERK1/2 phosphorylation was also examined in mouse hypothalamic neuronal cell lines with or without Ntsr1. We also examined the effect of the blockade of central ERK signaling on xenin-induced feeding suppression in mice. The intraperitoneal (i.p.) injection of xenin caused a significant increase in the number of pERK1/2-immunoreactive cells in the hypothalamic arcuate nucleus. The majority of pERK1/2-positive cells expressed neuronal nuclei (NeuN), a marker for neurons. Xenin treatment increased pERK1/2 levels in one cell line expressing Ntsr1 but not another line without Ntsr1 expression. Both i.p. and intracerebroventricular (i.c.v.) injections of xenin reduced food intake in mice. The i.c.v. pre-treatment with U0126, a selective inhibitor of ERK1/2 upstream kinases, did not affect xenin-induced reduction in food intake. These findings suggest that although xenin activates ERK signaling in subpopulations of hypothalamic neurons, xenin does not require the activation of hypothalamic ERK signaling pathway to elicit feeding suppression. PMID:27316340

  20. Shifting the circadian rhythm of feeding in mice induces gastrointestinal, metabolic and immune alterations which are influenced by ghrelin and the core clock gene Bmal1.

    Directory of Open Access Journals (Sweden)

    Jorien Laermans

    Full Text Available BACKGROUND: In our 24-hour society, an increasing number of people are required to be awake and active at night. As a result, the circadian rhythm of feeding is seriously compromised. To mimic this, we subjected mice to restricted feeding (RF, a paradigm in which food availability is limited to short and unusual times of day. RF induces a food-anticipatory increase in the levels of the hunger hormone ghrelin. We aimed to investigate whether ghrelin triggers the changes in body weight and gastric emptying that occur during RF. Moreover, the effect of genetic deletion of the core clock gene Bmal1 on these physiological adaptations was studied. METHODS: Wild-type, ghrelin receptor knockout and Bmal1 knockout mice were fed ad libitum or put on RF with a normal or high-fat diet (HFD. Plasma ghrelin levels were measured by radioimmunoassay. Gastric contractility was studied in vitro in muscle strips and in vivo (13C breath test. Cytokine mRNA expression was quantified and infiltration of immune cells was assessed histologically. RESULTS: The food-anticipatory increase in plasma ghrelin levels induced by RF with normal chow was abolished in HFD-fed mice. During RF, body weight restoration was facilitated by ghrelin and Bmal1. RF altered cytokine mRNA expression levels and triggered contractility changes resulting in an accelerated gastric emptying, independent from ghrelin signaling. During RF with a HFD, Bmal1 enhanced neutrophil recruitment to the stomach, increased gastric IL-1α expression and promoted gastric contractility changes. CONCLUSIONS: This is the first study demonstrating that ghrelin and Bmal1 regulate the extent of body weight restoration during RF, whereas Bmal1 controls the type of inflammatory infiltrate and contractility changes in the stomach. Disrupting the circadian rhythm of feeding induces a variety of diet-dependent metabolic, immune and gastrointestinal alterations, which may explain the higher prevalence of obesity and

  1. Utilization of Natural Products as Functional Feed

    Directory of Open Access Journals (Sweden)

    Stella Magdalena

    2013-03-01

    Full Text Available The use of antibiotics as feed additive improves performance in livestock. However, scientific data related to the use of antibiotics in feed merge spreading of bacterial resistance in animal and human bodies, therefore the usage of antibiotics in animal production is restricted. This condition raise the utilization of natural antibiotic as functional feed such as phytogenics (essential oil, flavonoid, saponin, and tannin, enzyme, probiotic, and prebiotic to improve the livestock’s performance, quality, and health. Functional feeds increase profitability in animal husbandry production and its use is feeds are expected to be functional foods that may have positive effects in human nutrition.

  2. 78 FR 75515 - Veterinary Feed Directive

    Science.gov (United States)

    2013-12-12

    ... bacterial resistance to antimicrobial drugs. After considerable deliberation between FDA and the animal... resistance in human and animal bacterial pathogens when medically important antimicrobial drugs are used in..., antimicrobial resistance, or other reasons may dictate that the use of a medicated feed be limited to use...

  3. Experimental feeding of Hydrilla verticillata colonized by stigonematales cyanobacteria induces vacuolar myelinopathy in painted turtles (Chrysemys picta.

    Directory of Open Access Journals (Sweden)

    Albert D Mercurio

    Full Text Available Vacuolar myelinopathy (VM is a neurologic disease primarily found in birds that occurs when wildlife ingest submerged aquatic vegetation colonized by an uncharacterized toxin-producing cyanobacterium (hereafter "UCB" for "uncharacterized cyanobacterium". Turtles are among the closest extant relatives of birds and many species directly and/or indirectly consume aquatic vegetation. However, it is unknown whether turtles can develop VM. We conducted a feeding trial to determine whether painted turtles (Chrysemys picta would develop VM after feeding on Hydrilla (Hydrilla verticillata, colonized by the UCB (Hydrilla is the most common "host" of UCB. We hypothesized turtles fed Hydrilla colonized by the UCB would exhibit neurologic impairment and vacuolation of nervous tissues, whereas turtles fed Hydrilla free of the UCB would not. The ability of Hydrilla colonized by the UCB to cause VM (hereafter, "toxicity" was verified by feeding it to domestic chickens (Gallus gallus domesticus or necropsy of field collected American coots (Fulica americana captured at the site of Hydrilla collections. We randomly assigned ten wild-caught turtles into toxic or non-toxic Hydrilla feeding groups and delivered the diets for up to 97 days. Between days 82 and 89, all turtles fed toxic Hydrilla displayed physical and/or neurologic impairment. Histologic examination of the brain and spinal cord revealed vacuolations in all treatment turtles. None of the control turtles exhibited neurologic impairment or had detectable brain or spinal cord vacuolations. This is the first evidence that freshwater turtles can become neurologically impaired and develop vacuolations after consuming toxic Hydrilla colonized with the UCB. The southeastern United States, where outbreaks of VM occur regularly and where vegetation colonized by the UCB is common, is also a global hotspot of freshwater turtle diversity. Our results suggest that further investigations into the effect of the

  4. Enhanced levels of plant cell cycle inhibitors hamper root-knot nematode-induced feeding site development

    OpenAIRE

    Vieira, Paulo; Engler, Gilbert; de Almeida Engler, Janice

    2013-01-01

    Root-knot nematodes (RKN) are highly specialized, obligatory plant parasites. These animals reprogram root cells to form large, multinucleate, and metabolically active feeding cells (giant cells) that provide a continuous nutrient supply during 3–6 weeks of the nematode’s life. The establishment and maintenance of physiologically fully functional giant cells are necessary for the survival of these nematodes. As such, giant cells may be useful targets for applying strategies to reduce damage c...

  5. 土壤食细菌线虫对拟南芥根系生长的影响及机理%The impact of bacterial-feeding nematodes on root growth of Arabidopsis thaliana L.and the possible mechanisms

    Institute of Scientific and Technical Information of China (English)

    成艳红; 陈小云; 刘满强; 胡锋; 李辉信

    2011-01-01

    通过设置两种孔径(1 mm和5μm)的网袋(25cm×25 cm),采用于土样中添加猪粪的处理,获得有大量食细菌线虫富集(SM1)的,和有少量食细菌线虫富集(SM5)的供试土壤(两者养分状况相近),以研究食细菌线虫对拟南芥根系生长的影响.结果表明,在种植拟南芥15d后,与有少量线虫富集的PSM5处理相比,有大量线虫富集的PSM1处理拟南芥根系显著增长,根的表面积显著增大,根尖数显著增多.PSM1处理在显著增加土壤中NH4+-N的同时,还使土壤中植物激素(GA3和IAA)的含量显著增高.此外,土壤微生物群落对单一碳源的利用能力(Biolog)的差异,表明存在大量食细菌线虫的土壤,微生物群落结构组成发生了变化.此结果说明,土壤食细菌线虫对根系生长影响的效应,除了养分效应外,还存在激素效应,与食细菌原生动物和植物根系生长之间的相互作用的机制相似.%Bacterial-feeding nematodes, one of the primary grazers of soil bacteria, affect root growth in several plant species. Most researches realized that the effects of bacterial-feeding nematodes on plant root growth resulted from direct or indirect nutrient effects ( mainly nitrogen mineralization). Bacterial-feeding nematodes grazing on bacteria accelerate bacterial turnover and increase the turnover of soil organic matter, increased the nitrogen mineralization and improved the supply of inorganic nitrogen, and subsequently the plant growth was stimulated. Several researchers, however, have claimed that this process may not fully explain the mechanism of bacterial-feeding nematode stimulating plant growth. Considering the similarly of the physiology and zoology between bacterial-feeding nematodes and protozoa, and that the bacterial-feeding nematodes occur at equal or greater biomass in the rhizosphere than protozoa, it is believed that the activity of bacterial-feeding nematodes in the rhizosphere will also stimulate root proliferation by

  6. Yeast Cell Wall Extract Induces Disease Resistance against Bacterial and Fungal Pathogens in Arabidopsis thaliana and Brassica Crop

    OpenAIRE

    Narusaka, Mari; Minami, Taichi; Iwabuchi, Chikako; Hamasaki, Takashi; Takasaki, Satoko; Kawamura, Kimito; Narusaka, Yoshihiro

    2015-01-01

    Housaku Monogatari (HM) is a plant activator prepared from a yeast cell wall extract. We examined the efficacy of HM application and observed that HM treatment increased the resistance of Arabidopsis thaliana and Brassica rapa leaves to bacterial and fungal infections. HM reduced the severity of bacterial leaf spot and anthracnose on A. thaliana and Brassica crop leaves with protective effects. In addition, gene expression analysis of A. thaliana plants after treatment with HM indicated incre...

  7. Enhancement of Urinary Bladder Carcinogenesis by the Role of Chronic Bacterial Infection-induced Inflammation (Imunnohistochemical and Biochemical studies)

    OpenAIRE

    Gabri MS*, Ashmawy AM**, Ibrahim MA*, Hosny RM

    2012-01-01

    Background: Bacterial infections traditionally have not been considered major causes of cancer. Recently, however, bacteria have been linked to cancer by two mechanisms: induction of chronic inflammation and production of carcinogenic bacterial metabolites. The most specific example of the inflammatory mechanism of carcinogenesis is Escherichia coli infection. E. coli has been epidemiologically linked to urothelial carcinoma of the urinary bladder by its propensity to cause lifelong inflammat...

  8. Utilization of Natural Products as Functional Feed

    OpenAIRE

    Stella Magdalena; Natadiputri G H; Nailufar; Purwadaria T

    2013-01-01

    The use of antibiotics as feed additive improves performance in livestock. However, scientific data related to the use of antibiotics in feed merge spreading of bacterial resistance in animal and human bodies, therefore the usage of antibiotics in animal production is restricted. This condition raise the utilization of natural antibiotic as functional feed such as phytogenics (essential oil, flavonoid, saponin, and tannin), enzyme, probiotic, and prebiotic to improve the livestock’s performan...

  9. Canine uterine bacterial infection induces upregulation of proteolysis-related genes and downregulation of homeobox and zinc finger factors.

    Directory of Open Access Journals (Sweden)

    Ragnvi Hagman

    Full Text Available BACKGROUND: Bacterial infection with the severe complication of sepsis is a frequent and serious condition, being a major cause of death worldwide. To cope with the plethora of occurring bacterial infections there is therefore an urgent need to identify molecular mechanisms operating during the host response, in order both to identify potential targets for therapeutic intervention and to identify biomarkers for disease. Here we addressed this issue by studying global gene expression in uteri from female dogs suffering from spontaneously occurring uterine bacterial infection. PRINCIPAL FINDINGS: The analysis showed that almost 800 genes were significantly (p2-fold in the uteri of diseased animals. Among these were numerous chemokine and cytokine genes, as well as genes associated with inflammatory cell extravasation, anti-bacterial action, the complement system and innate immune responses, as well as proteoglycan-associated genes. There was also a striking representation of genes associated with proteolysis. Robust upregulation of immunoglobulin components and genes involved in antigen presentation was also evident, indicating elaboration of a strong adaptive immune response. The bacterial infection was also associated with a significant downregulation of almost 700 genes, of which various homeobox and zinc finger transcription factors were highly represented. CONCLUSIONS/SIGNIFICANCE: Together, these finding outline the molecular patterns involved in bacterial infection of the uterus. The study identified altered expression of numerous genes not previously implicated in bacterial disease, and several of these may be evaluated for potential as biomarkers of disease or as therapeutic targets. Importantly, since humans and dogs show genetic similarity and develop diseases that share many characteristics, the molecular events identified here are likely to reflect the corresponding situation in humans afflicted by similar disease.

  10. The clinical utility of induced sputum for the diagnosis of bacterial community-acquired pneumonia in HIV-infected patients: a prospective cross-sectional study

    Directory of Open Access Journals (Sweden)

    Rosemeri Maurici da Silva

    2006-04-01

    Full Text Available BACKGROUND: Bacterial pneumonias have been overcoming pneumocytosis in frequency. Controversy still remains about how to manage immunocompromised patients and those with lung diseases. Sputum analysis is a noninvasive and simple method, and when interpreted according to specific criteria it may help with diagnosis. We conducted a study to evaluate sensitivity, specificity, positive and negative predicted values, and the accuracy of induced sputum (IS for bacterial community-acquired pneumonia diagnosis in HIV-positive patients. MATERIAL AND METHODS: This cross sectional study evaluated a diagnostic procedure in a reference hospital for HIV patients in Florianópolis, SC, Brazil. From January 1, 2001 to September 30, 2002, 547 HIV-positive patients were analyzed and 54 inpatients with pulmonary infection were selected. Bronchoalveolar lavage (BAL and transbronchial lung biopsy (TBLB were considered the gold standards. Gram stains and quantitative cultures of IS and BAL were obtained. The cut-offs for quantitative cultures were 10(6 CFU/mL for IS and 10(4 CFU/mL for BAL. RESULTS: The mean age was 35.7 years, 79.6% were males and 85.2% were caucasians. The mean lymphocyte count was 124.8/mm³. Bacterial pneumonia was diagnosed in 20 patients. The most prevalent bacteria was Streptococcus pneumoniae. Considering IS for the diagnosis of bacterial pneumonia, sensitivity was 60%, specificity 40%, the positive predictive value was 80%, negative predictive value 20% and accuracy 56%. CONCLUSION: IS with quantitative culture can be helpful for the diagnosis of bacterial pneumonia in HIV-positive patients.

  11. The pressures of suction feeding: the relation between buccal pressure and induced fluid speed in centrarchid fishes.

    Science.gov (United States)

    Higham, Timothy E; Day, Steven W; Wainwright, Peter C

    2006-09-01

    Suction feeding fish rapidly expand their oral cavity, resulting in a flow of water directed towards the mouth that is accompanied by a drop in pressure inside the buccal cavity. Pressure inside the mouth and fluid speed external to the mouth are understood to be mechanically linked but the relationship between them has never been empirically determined in any suction feeder. We present the first simultaneous measurements of fluid speed and buccal pressure during suction feeding in fishes. Digital particle image velocimetry (DPIV) and high-speed video were used to measure the maximum fluid speed in front of the mouth of four largemouth bass and three bluegill sunfish by positioning a vertical laser sheet on the mid-sagittal plane of the fish. Peak magnitude of pressure inside the buccal cavity was quantified using a transducer positioned within a catheter that opened into the dorsal wall of the buccal cavity. In both species the time of peak pressure preceded the time of peak fluid speed by as much as 42 ms, indicating a role for unsteady flow effects in shaping this relation. We parameterized an existing model of suction feeding to determine whether the relationship between peak pressures and fluid speeds that we observed could be predicted using just a few kinematic variables. The model predicted much higher fluid speeds than we measured at all values of peak pressure and gave a scaling exponent between them (0.51) that was higher than observed (0.36 for largemouth bass, 0.38 for bluegill). The scaling between peak buccal pressure and peak fluid speed at the mouth aperture differed in the two species, supporting the recent conclusion that species morphology affects this relation such that a general pattern may not hold. PMID:16916963

  12. Variations of both bacterial community and extracellular polymers: the inducements of increase of cell hydrophobicity from biofloc to aerobic granule sludge.

    Science.gov (United States)

    Guo, Feng; Zhang, Sheng-Hua; Yu, Xin; Wei, Bo

    2011-06-01

    To investigate the inducements of increase of cell hydrophobicity from aerobic biofloc (ABF) and granular sludge (AGS), in this study, as the first time the hydrophilic and hydrophobic bacterial communities were analyzed independently. Meanwhile, the effect of extracellular polymers (EPS) on the cell hydrophobicity is also studied. Few Bacteroidetes were detected (1.35% in ABF and 3.84% in AGS) in hydrophilic bacteria, whereas they are abundant in the hydrophobic cells (47.8% and 43% for ABF and AGS, respectively). The main species of Bacteroidetes changed from class Sphingobacteria to Flavobacteria in AGS. On the other hand, EPS is directly responsible to cell hydrophobicity. For AGS, cell hydrophobicity was sharply decreased after EPS extraction. Both quantity and property of the extracellular protein are related to hydrophobicity. Our results showed the variation of cell hydrophobicity was resulted from variations of both bacterial population and EPS. PMID:21482465

  13. Feeding a High-Concentrate Corn Straw Diet Induced Epigenetic Alterations in the Mammary Tissue of Dairy Cows

    OpenAIRE

    Dong, Guozhong; Qiu, Min; Ao, Changjin; Zhou, Jun; Khas-Erdene,; Wang, Xi; Zhang, Zhu; YANG You

    2014-01-01

    Purpose The objective of this study was to investigate the effects of feeding a high-concentrate corn straw (HCS) diet (65% concentrate+35% corn straw) on the epigenetic changes in the mammary tissue of dairy cows in comparison with a low-concentrate corn straw (LCS) diet (46% concentrate+54% corn straw) and with a low-concentrate mixed forage (LMF) diet (46% concentrate+54% mixed forage). Experimental Design Multiparous mid-lactation Chinese Holstein cows were fed one of these three diets fo...

  14. Gamma irradiation induced mutation for the improvement of Josapine pineapple against bacterial heart rot disease and improved fruit quality

    International Nuclear Information System (INIS)

    Bacteria heart rot disease, caused by Erwinia chrysanthemi, is one of the most serious diseases of the susceptible cultivars of pineapple in Malaysia, namely, Josapine, Sarawak, Gandul and N36. Using acute irradiation of gamma-rays and in vitro cultured meristems, the selection of resistant mutant to bacterial heart rot disease with improved fruit quality has been carried out using radiation-induced mutagenesis of the most popular variety, Josapine. Meristem explants were irradiated with a series of gamma-ray doses of 0, 20, 40, 60, 80, 100, 120, 140 and 160Gy and radiosensitivity was investigated based on shoot formation and survival rate. The lethal dose required for 50% (LD50) and 100% (LD100) of meristem tissues for shoot formation was 40Gy and 83Gy respectively. On the other hand, the lethal dose required for 50% (LD50) and 100% (LD100) for survival rate was 77Gy and 147Gy respectively. Shoots derived from irradiated meristem explants at 10, 20, 30 and 40Gy were sub-cultured up to M1V5 to minimize chimerism. Multiplication of irradiated shoots was carried out in Temporary Immersion Bioreactor System using MS liquid media supplemented with 2.5mg/l benzyl aminopurine (BA). Rooting was promoted on MS media supplemented with 2mg/l indole-3-butyric acid (IBA) and rooted plantlets were hardened in the nursery for 2 months. Preliminary screening of 20,000 irradiated plants in the nursery indicated 60% with smooth leaves, besides vigorous growth. Selected mutant plantlets were field planted in hot spot until fruiting. At lower doses of 10 and 20Gy, there were no potential resistant mutant plants with significant improvement in total sugar content and fruit weight observed. However, at higher doses of 30 and 40Gy, 11 and 5 resistant plants with significant increase in both total sugar content and fruit weight were recorded, respectively. Molecular analysis using AFLP was conducted to identify markers for the selected characters. (author)

  15. Bacterial wall products induce downregulation of vascular endothelial growth factor receptors on endothelial cells via a CD14-dependent mechanism: implications for surgical wound healing.

    LENUS (Irish Health Repository)

    Power, C

    2012-02-03

    INTRODUCTION: Vascular endothelial growth factor (VEGF) is a potent mitogenic cytokine which has been identified as the principal polypeptide growth factor influencing endothelial cell (EC) migration and proliferation. Ordered progression of these two processes is an absolute prerequisite for initiating and maintaining the proliferative phase of wound healing. The response of ECs to circulating VEGF is determined by, and directly proportional to, the functional expression of VEGF receptors (KDR\\/Flt-1) on the EC surface membrane. Systemic sepsis and wound contamination due to bacterial infection are associated with significant retardation of the proliferative phase of wound repair. The effects of the Gram-negative bacterial wall components lipopolysaccharide (LPS) and bacterial lipoprotein (BLP) on VEGF receptor function and expression are unknown and may represent an important biological mechanism predisposing to delayed wound healing in the presence of localized or systemic sepsis. MATERIALS AND METHODS: We designed a series of in vitro experiments investigating this phenomenon and its potential implications for infective wound repair. VEGF receptor density on ECs in the presence of LPS and BLP was assessed using flow cytometry. These parameters were assessed in hypoxic conditions as well as in normoxia. The contribution of CD14 was evaluated using recombinant human (rh) CD14. EC proliferation in response to VEGF was quantified in the presence and absence of LPS and BLP. RESULTS: Flow cytometric analysis revealed that LPS and BLP have profoundly repressive effects on VEGF receptor density in normoxic and, more pertinently, hypoxic conditions. The observed downregulation of constitutive and inducible VEGF receptor expression on ECs was not due to any directly cytotoxic effect of LPS and BLP on ECs, as measured by cell viability and apoptosis assays. We identified a pivotal role for soluble\\/serum CD14, a highly specific bacterial wall product receptor, in

  16. A Comparison of Diets Supplemented with a Feed Additive Containing Organic Acids, Cinnamaldehyde and a Permeabilizing Complex, or Zinc Oxide, on Post-Weaning Diarrhoea, Selected Bacterial Populations, Blood Measures and Performance in Weaned Pigs Experimentally Infected with Enterotoxigenic E. coli †

    Science.gov (United States)

    Stensland, Ingunn; Kim, Jae Cheol; Bowring, Bethany; Collins, Alison M.; Mansfield, Josephine P.; Pluske, John R.

    2015-01-01

    Simple Summary This experiment was conducted to assess the effects of three diets on diarrhoea, performance (weight change, feed intake and feed conversion ratio), selected bacterial populations and blood measures of weaner pigs infected with enterotoxigenic E. coli. The three diets were: base diet (no antimicrobial compounds), base diet containing zinc oxide, and base diet containing a feed additive (blend of organic acids, cinnamaldehyde and permeabilizing complex). Only feeding zinc oxide decreased diarrhoea, with zinc oxide-fed pigs performing better than base diet-fed pigs. Zinc oxide-fed pigs performed similarly to pigs fed the organic acids, cinnamaldehyde and permeabilizing complex. Significant interactions between treatment and day after weaning were found for some bacterial populations, although the implications of such findings require further examination. Abstract The effects of feeding a diet supplemented with zinc oxide (ZnO) or a blend of organic acids, cinnamaldehyde and a permeabilizing complex (OACP) on post-weaning diarrhoea (PWD) and performance in pigs infected with enterotoxigenic E. coli (ETEC) were examined. Additionally, changes in selected bacterial populations and blood measures were assessed. A total of 72 pigs weaned at 22 d of age and weighing 7.2 ± 1.02 kg (mean ± SEM) was used. Treatments were: base diet (no antimicrobial compounds); base diet + 3 g ZnO/kg; base diet + 1.5 g OACP/kg. Dietary treatments started on the day of weaning and were fed ad libitum for 3 weeks. All pigs were infected with an F4 ETEC on d 4, 5 and 6 after weaning. The incidence of PWD was lower in pigs fed ZnO (p = 0.026). Overall, pigs fed ZnO grew faster (p = 0.013) and ate more (p = 0.004) than the base diet-fed pigs, with OACP-fed pigs performing the same (p > 0.05) as both the ZnO- and base diet-fed pigs. Feed conversion ratio was similar for all diets (p > 0.05). The percentage of E. coli with F4 fimbriae was affected a day by treatment interaction (p

  17. Polyphenol-rich extract of Vernonia amygdalina (del. leaves ameliorated cadmium-induced alterations in feeding pattern and urine volume of male Wistar rats.

    Directory of Open Access Journals (Sweden)

    Christian Eseigbe Imafidon

    2015-12-01

    Full Text Available Aim: To determine the effects of polyphenol-rich extract of the leaves of Vernonia amygdalina (PEVA on the feeding pattern of rats that were exposed to cadmium (Cd toxicity. Materials and Methods: Thirty male Wistar rats, weighing 160-180 g, were divided into 6 groups of 5 rats each as follows; Group 1 received distilled water orally (0.2 ml/100 g, daily, throughout the period of study. Group 2 received Cd alone (in the form of CdSO4 at 5 mg/kg/day via intraperitoneal route for 5 consecutive days. Group 3 were pre-treated with Cd as Group 2 and thereafter left untreated for a period of 4-week. After the oral lethal dose of PEVA was determined, Groups 4, 5, and 6 were pre-treated with Cd as Group 2 after which they received graded doses of PEVA at 100, 200 and 400 mg/kg/day (0.2 ml/100 g, respectively via oral route for 4 weeks. Blood samples were collected for some plasma biochemical assays while urine samples were collected using metabolic cages. Results: PEVA administration significantly increased (P < 0.05 the body weight and feeding patterns that were significantly reduced (P < 0.05 by Cd toxicity. PEVA also significantly reinstated the plasma antioxidant status, as well as glucose and urine volume of the rats toward control values (P < 0.05. Conclusion: PEVA can be an herbal alternative in the treatment or management of subjects manifesting alterations in feeding pattern and urine volume that is Cd-induced. [J Intercult Ethnopharmacol 2015; 4(4.000: 284-292

  18. Blood feeding by the Rocky Mountain spotted fever vector, Dermacentor andersoni, induces interleukin-4 expression by cognate antigen responding CD4+ T cells

    Directory of Open Access Journals (Sweden)

    Wikel Stephen K

    2009-10-01

    Full Text Available Abstract Background Tick modulation of host defenses facilitates both blood feeding and pathogen transmission. Several tick species deviate host T cell responses toward a Th2 cytokine profile. The majority of studies of modulation of T cell cytokine expression by ticks were performed with lymphocytes from infested mice stimulated in vitro with polyclonal T cell activators. Those reports did not examine tick modulation of antigen specific responses. We report use of a transgenic T cell receptor (TCR adoptive transfer model reactive with influenza hemagglutinin peptide (110-120 to examine CD4+ T cell intracellular cytokine responses during infestation with the metastriate tick, Dermacentor andersoni, or exposure to salivary gland extracts. Results Infestation with pathogen-free D. andersoni nymphs or administration of an intradermal injection of female or male tick salivary gland extract induced significant increases of IL-4 transcripts in skin and draining lymph nodes of BALB/c mice as measured by quantitative real-time RT-PCR. Furthermore, IL-10 transcripts were significantly increased in skin while IL-2 and IFN-γ transcripts were not significantly changed by tick feeding or intradermal injection of salivary gland proteins, suggesting a superimposed Th2 response. Infestation induced TCR transgenic CD4+ T cells to divide more frequently as measured by CFSE dilution, but more notably these CD4+ T cells also gained the capacity to express IL-4. Intracellular levels of IL-4 were significantly increased. A second infestation administered 14 days after a primary exposure to ticks resulted in partially reduced CFSE dilution with no change in IL-4 expression when compared to one exposure to ticks. Intradermal inoculation of salivary gland extracts from both male and female ticks also induced IL-4 expression. Conclusion This is the first report of the influence of a metastriate tick on the cytokine profile of antigen specific CD4+ T cells. Blood feeding

  19. 关注肥胖相关的进食行为及防治策略%Focus on the feeding behaviors inducing obesity and their regulation strategies

    Institute of Scientific and Technical Information of China (English)

    章玲丽; 李斐

    2015-01-01

    肥胖是日益严重的全球公共卫生问题,其中能量过剩型肥胖是肥胖的主要类型。能量过剩型肥胖发生与食物偏好行为密切相关。本文简要介绍肥胖相关进食行为特点,食物偏好形成、发展过程可能涉及的神经生理机制。同时,建议以肥胖人群进食行为特点作为分类依据,根据食物偏好严重程度采取针对性干预措施,以期更好解决肥胖问题。%Obesity has become a worldwide public health concern. In particular, obesity caused by excessive energy intake was widespread which has strong causal relationship with food preference behaviors. In this review, we would briefly talk about characteristics of feeding behaviors inducing obesity, as well as the possible neurophysiological mechanisms involved in food preference formation and development. Meantime, we would introduce some regulation strategies to deal with obesity which mainly based on the current feeding behaviors of the obese.

  20. Elevated IgG levels against specific bacterial antigens in obese patients with diabetes and in mice with diet-induced obesity and glucose intolerance.

    Science.gov (United States)

    Mohammed, Nadeem; Tang, Lihua; Jahangiri, Anisa; de Villiers, Willem; Eckhardt, Erik

    2012-09-01

    High fat diets increase the risk for insulin resistance by promoting inflammation. The cause of inflammation is unclear, but germfree mouse studies have implicated commensal gut bacteria. We tested whether diet-induced obesity, diabetes, and inflammation are associated with anti-bacterial IgG. Blood from lean and obese healthy volunteers or obese patients with diabetes were analyzed by ELISA for IgG against extracts of potentially pathogenic and pro-biotic strains of Escherichia coli (LF-82 and Nissle), Bacteroides thetaiotaomicron, and Lactobacillus acidophilus, and for circulating tumor necrosis factor α (TNFα). C57Bl/6 mice were fed low- or high-fat diets (10% or 60% kcal from fat) for 10 weeks and tested for anti-bacterial IgG, bodyweight, fasting glucose, and inflammation. Obese diabetic patients had significantly more IgG against extracts of E. coli LF-82 compared with lean controls, whereas IgG against extracts of the other bacteria was unchanged. Circulating TNFα was elevated and correlated with IgG against the LF-82 extract. Mice fed high-fat diets had increased fasting glucose levels, elevated TNFα and neutrophils, and significantly more IgG against the LF-82 extracts. Diabetes in obesity is characterized by increased IgG against specific bacterial antigens. Specific commensal bacteria may mediate inflammatory effects of high-fat diets. PMID:22424821

  1. Chemopreventive effect of myrtenal on bacterial enzyme activity and the development of 1,2-dimethyl hydrazine-induced aberrant crypt foci in Wistar Rats

    Directory of Open Access Journals (Sweden)

    Lokesh Kumar Booupathy

    2016-01-01

    Full Text Available Colon cancer remains as a serious health problem around the world despite advances in diagnosis and treatment. Dietary fibers are considered to reduce the risk of colon cancer as they are converted to short chain fatty acids by the presence of anaerobic bacteria in the intestine, but imbalanced diet and high fat consumption may promote tumor formation at different sites, including the large bowel via increased bacterial enzymes activity. The present study was conducted to characterize the inhibitory action of myrtenal on bacterial enzymes and aberrant crypt foci (ACF. Experimental colon carcinogenesis induced by 1,2-dimethylhydrazine is histologically, morphologically, and anatomically similar to human colonic epithelial neoplasm. Discrete microscopic mucosal lesions such as ACF and malignant tumors function as important biomarkers in the diagnosis of colon cancer. Methylene blue staining was carried out to visualize the impact of 1,2-dimethylhydrazine and myrtenal. Myrtenal-treated animals showed decreased levels of bacterial enzymes such as β-glucuronidase, β-glucosidase, and mucinase. Characteristic changes in the colon were noticed by inhibiting ACF formation in the colon. In conclusion, treatment with myrtenal provided altered pathophysiological condition in colon cancer-bearing animals with evidence of decreased crypt multiplicity and tumor progression.

  2. Feeding guilt.

    Science.gov (United States)

    Byrom, Anna

    2013-03-01

    Breastfeeding is increasingly equated to ideologies of the 'good mother' in our society in response to a growing body of evidence identifying its benefits. Women who choose not to or are unable to breastfeed can experience a sense of guilt in response to cultural expectations that 'breast is best'. These negative feelings can impact upon their adaptation to and enjoyment of motherhood. This discussion paper examines the experience of maternal guilt with specific reference to infant feeding. An exploration of the reasons mothers may feel guilty about their feeding experiences is offered. Finally some suggestions are made about how midwives and breastfeeding advocates might improve care for mothers' emotional wellbeing. PMID:23590082

  3. Petrographic and geochemical evidence for the formation of primary, bacterially induced lacustrine dolomite: La Roda 'white earth' (Pliocene, Central Spain)

    Science.gov (United States)

    Garcia, Del; Cura, M.A.; Calvo, J.P.; Ordonez, S.; Jones, B.F.; Canaveras, J.C.

    2001-01-01

    Upper Pliocene dolomites ('white earth') from La Roda, Spain, offer a good opportunity to evaluate the process of dolomite formation in lakes. The relatively young nature of the deposits could allow a link between dolomites precipitated in modern lake systems and those present in older lacustrine formations. The La Roda Mg-carbonates (dolomite unit) occur as a 3??5- to 4-m- thick package of poorly indurated, white, massive dolomite beds with interbedded thin deposits of porous carbonate displaying root and desiccation traces as well as local lenticular gypsum moulds. The massive dolomite beds consist mainly of loosely packed 1- to 2-??m-sized aggregates of dolomite crystals exhibiting poorly developed faces, which usually results in a subrounded morphology of the crystals. Minute rhombs of dolomite are sparse within the aggregates. Both knobbly textures and clumps of spherical bodies covering the crystal surfaces indicate that bacteria were involved in the formation of the dolomites. In addition, aggregates of euhedral dolomite crystals are usually present in some more clayey (sepiolite) interbeds. The thin porous carbonate (mostly dolomite) beds exhibit both euhedral and subrounded, bacterially induced dolomite crystals. The carbonate is mainly Ca-dolomite (51-54 mol% CaCO3), showing a low degree of ordering (degree of ordering ranges from 0??27 to 0??48). Calcite is present as a subordinate mineral in some samples. Sr, Mn and Fe contents show very low correlation coefficients with Mg/Ca ratios, whereas SiO2 and K contents are highly correlated. ??18O- and ??13C-values in dolomites range from -3??07??? to 5??40??? PDB (mean = 0??06, ?? = 1??75) and from -6??34??? to -0??39??? PDB (mean = -3??55, ?? = 1??33) respectively. Samples containing significant amounts of both dolomite and calcite do not in general show significant enrichment or depletion in 18O and 13C between the two minerals. The correlation coefficient between ??18O and ??13C for dolomite is extremely

  4. Bacterial Stationary-State Mutagenesis and Mammalian Tumorigenesis as Stress-Induced Cellular Adaptations and the Role of Epigenetics

    OpenAIRE

    Karpinets, TV; Greenwood, DJ; Pogribny, IP; Samatova, NF

    2006-01-01

    Mechanisms of cellular adaptation may have some commonalities across different organisms. Revealing these common mechanisms may provide insight in the organismal level of adaptation and suggest solutions to important problems related to the adaptation. An increased rate of mutations, referred as the mutator phenotype, and beneficial nature of these mutations are common features of the bacterial stationary-state mutagenesis and of the tumorigenic transformations in mammalian cells. We argue th...

  5. Surfactant improves lung function and mitigates bacterial growth in immature ventilated rabbits with experimentally induced neonatal group B streptococcal pneumonia

    OpenAIRE

    Herting, E.; Sun, B.; Jarstrand, C; Curstedt, T; Robertson, B.

    1997-01-01

    Aims—To study the influence of surfactant on lung function and bacterial proliferation in immature newborn rabbits with experimental group B streptococcal (GBS) pneumonia.
METHODS—Preterm rabbit fetuses (gest-ational age 28 days) underwent tracheotomy and were mechanically ventilated in a warmed body plethysmograph that permitted measurement of lung-thorax compliance. Fifteen minutes after the onset of ventilation the animals received either GBS or saline intratracheally; at 30 minutes, a bol...

  6. Radiation-induced grafting of vinylbenzyltrimethylammonium chloride (VBT) onto cotton fabric and study of its anti-bacterial activities

    International Nuclear Information System (INIS)

    Mutual radiation grafting technique using 60Co gamma radiation has been used to carry out grafting of vinylbenzyltrimethylammonium chloride (VBT) onto cotton cellulose substrate. Grafting yield increased with radiation dose and decreased with dose rate but was adversely affected by the presence of O2 and salts of Fe2+ and Cu2+. However, the presence of an acid did not affect grafting in the concentration range studied. The effect of organic solvents like methanol, ethanol, n-propanol, iso-propanol, tert-butanol on grafting yield was investigated in the mixed aqueous solvent system. The VBT grafted cotton samples showed significantly higher water uptake and water retention properties and possessed excellent anti-bacterial activity against strains like Escherichia coli and Staphylococcus aureus. Samples with 25% grafting extent showed 6 log cycles reduction in bacterial counts within 6 h of exposure time. The anti-bacterial activity of the grafted cotton samples was retained after several cycles of washing and drying in a commercial detergent powder

  7. Changes in nucleus accumbens dopamine transmission associated with fixed- and variable-time schedule-induced feeding.

    Science.gov (United States)

    Richardson, Nicole R; Gratton, Alain

    2008-05-01

    We examined the changes in nucleus accumbens (NAcc) dopamine (DA) transmission associated with non-contingent meal presentations under conditions of high (fixed time-, FT-schedule) and low (variable time-, VT-schedule) predictability. Of interest were the changes in NAcc DA transmission associated with discrepancies between the time food is expected and when it is actually presented. We used in vivo voltammetry to monitor NAcc DA levels as rats received, on the first and second test days, 30-s meals of condensed milk on a VT-52 schedule (inter-meal intervals of 32, 35, 40, 45, 52, 64, and 95 s). On the third and subsequent days meals were presented first on a VT-52 s schedule and then on an FT-52 s schedule. On day 1, monotonic increases in NAcc DA signals were observed during both meal consumption and the intervals between VT meal presentations. By day 2, however, meal presentations on the VT schedule elicited biphasic DA signal fluctuations; DA signals increased prior to each meal presentation but then started to decline during the feeding bout that followed. Fixed-time meal presentations on day 3 disrupted this pattern, resulting in a concurrent escalation of DA signal fluctuations upon subsequent VT meal presentations. These findings provide further evidence that, in trained animals, NAcc DA transmission is activated by conditioned incentive cues rather than by primary rewards. They also suggest that the increases in NAcc DA transmission associated with reward expectancy are sensitive to temporal cues (e.g. interval timing) and to discrepancies between expected and actual outcomes. PMID:18513317

  8. Thermal stress induces changes in gene expression and blood parameters in high and low feed efficiency meat quail.

    Science.gov (United States)

    Gasparino, Eliane; Voltolini, Débora Marques; Del Vesco, Ana Paula; Marcato, Simara Marcia; Zancanela, Vittor; de Oliveira Grieser, Daiane; de Souza Khatlab, Angélica; Guimarães, Simone Eliza Facioni; de Oliveira Neto, Adhemar Rodriges

    2015-05-01

    In this study, we analysed markers of stress, plasma creatinine and T3 content, and insulin-like growth factor I (IGF-I), growth hormone receptor (GHR), uncoupling protein (UCP), adenine nucleotide translocase (ANT) and cytochrome c oxidase subunit III (COX III) mRNA expression in the liver and muscle of high (0.22 g/g) and low (0.14 g/g) feed efficiency (FE) meat quail at three different air temperatures, comfortable, heat and cold stress, for 24 h. High FE quail presented higher plasma T3 and lower creatinine levels. IGF-I mRNA expression was higher in the livers of high FE quail than in the livers of low FE quail under both comfortable and cold stress conditions. In the muscle, regardless of the environment, high FE birds showed higher IGF-I mRNA expression. High FE birds also showed higher GHR mRNA expression under comfortable conditions. Regarding the environment, higher expression was observed in birds at comfortable conditions, and lower expression in birds under heat stress. UCP mRNA expression in the liver was lower in high FE birds and higher under heat stress compared with the other conditions. Low and high FE birds showed greater ANT mRNA expression in the muscle under cold stress. Greater mRNA COX III expressions were observed in the liver and muscle of quails under comfortable conditions. Our results suggest that temperature affects the expression of genes related to growth and mitochondrial energy production, and quail with different FEs respond differently to environmental stimuli. In comfortable conditions, high FE animals show higher IGF-I mRNA expression and plasma T3 and lower creatinine content. PMID:25190104

  9. Three Months of High-Fructose Feeding Fails to Induce Excessive Weight Gain or Leptin Resistance in Mice

    OpenAIRE

    Tillman, Erik J.; Morgan, Donald A.; Kamal Rahmouni; Swoap, Steven J.

    2014-01-01

    High-fructose diets have been implicated in obesity via impairment of leptin signaling in humans and rodents. We investigated whether fructose-induced leptin resistance in mice could be used to study the metabolic consequences of fructose consumption in humans, particularly in children and adolescents. Male C57Bl/6 mice were weaned to a randomly assigned diet: high fructose, high sucrose, high fat, or control (sugar-free, low-fat). Mice were maintained on their diets for at least 14 weeks. Wh...

  10. Pellet feed adsorbed with the recombinant Lactococcus lactis BFE920 expressing SiMA antigen induced strong recall vaccine effects against Streptococcus iniae infection in olive flounder (Paralichthys olivaceus).

    Science.gov (United States)

    Kim, Daniel; Beck, Bo Ram; Lee, Sun Min; Jeon, Jongsu; Lee, Dong Wook; Lee, Jae Il; Song, Seong Kyu

    2016-08-01

    The aim of this study was to develop a fish feed vaccine that provides effective disease prevention and convenient application. A lactic acid bacterium (LAB), Lactococcus lactis BFE920, was modified to express the SiMA antigen, a membrane protein of Streptococcus iniae. The antigen was engineered to be expressed under the nisin promoter, which is induced by nisin produced naturally by the host LAB. Various sizes (40 ± 3.5 g, 80 ± 2.1 g, and 221 ± 2.4 g) of olive flounder (Paralichthys olivaceus) were vaccinated by feeding the extruded pellet feed, onto which the SiMA-expressing L. lactis BFE920 (1.0 × 10(7) CFU/g) was adsorbed. Vaccine-treated feed was administered twice a day for 1 week, and priming and boosting were performed with a 1-week interval in between. The vaccinated fish had significantly elevated levels of antigen-specific serum antibodies and T cell marker mRNAs: CD4-1, CD4-2, and CD8a. In addition, the feed vaccine significantly induced T cell effector functions, such as the production of IFN-γ and activation of the transcription factor that induces its expression, T-bet. When the flounder were challenged by intraperitoneal infection and bath immersion with S. iniae, the vaccinated fish showed 84% and 82% relative percent survival (RPS), respectively. Furthermore, similar protective effects were confirmed even 3 months after vaccination in a field study (n = 4800), indicating that this feed vaccine elicited prolonged duration of immunopotency. In addition, the vaccinated flounder gained 21% more weight and required 16% less feed to gain a unit of body weight compared to the control group. The data clearly demonstrate that the L. lactis BFE920-SiMA feed vaccine has strong protective effects, induces prolonged vaccine efficacy, and has probiotic effects. In addition, this LAB-based fish feed vaccine can be easily used to target many different pathogens of diverse fish species. PMID:27302864

  11. Delayed development induced by toxicity to the host can be inherited by a bacterial-dependent, transgenerational effect

    OpenAIRE

    Fridmann-Sirkis, Yael; Stern, Shay; Elgart, Michael; Galili, Matana; Zeisel, Amit; Shental, Noam; Soen, Yoav

    2014-01-01

    Commensal gut bacteria in many species including flies are integral part of their host, and are known to influence its development and homeostasis within generation. Here we report an unexpected impact of host–microbe interactions, which mediates multi-generational, non-Mendelian inheritance of a stress-induced phenotype. We have previously shown that exposure of fly larvae to G418 antibiotic induces transgenerationally heritable phenotypes, including a delay in larval development, gene induc...

  12. A novel multi-stage subunit vaccine against paratuberculosis induces significant immunity and reduces bacterial burden in tissues (P4304)

    DEFF Research Database (Denmark)

    Thakur, Aneesh; Aagaard, Claus; Riber, Ulla;

    2013-01-01

    Effective control of paratuberculosis is hindered by lack of a vaccine preventing infection, transmission and without diagnostic interference with tuberculosis. We have developed a novel multi-stage recombinant subunit vaccine in which a fusion of four early expressed MAP antigens is combined with...... characterized by a significant containment of bacterial burden in gut tissues compared to non-vaccinated animals. There was no cross-reaction with bovine tuberculosis in vaccinated animals. This novel multi-stage vaccine has the potential to become a marker vaccine for paratuberculosis....

  13. Bacterial extracellular lignin peroxidase

    Science.gov (United States)

    Crawford, Donald L.; Ramachandra, Muralidhara

    1993-01-01

    A newly discovered lignin peroxidase enzyme is provided. The enzyme is obtained from a bacterial source and is capable of degrading the lignin portion of lignocellulose in the presence of hydrogen peroxide. The enzyme is extracellular, oxidative, inducible by lignin, larch wood xylan, or related substrates and capable of attacking certain lignin substructure chemical bonds that are not degradable by fungal lignin peroxidases.

  14. Comprehensive Proteomic and Metabolomic Signatures of Nontypeable Haemophilus influenzae-Induced Acute Otitis Media Reveal Bacterial Aerobic Respiration in an Immunosuppressed Environment.

    Science.gov (United States)

    Harrison, Alistair; Dubois, Laura G; St John-Williams, Lisa; Moseley, M Arthur; Hardison, Rachael L; Heimlich, Derek R; Stoddard, Alexander; Kerschner, Joseph E; Justice, Sheryl S; Thompson, J Will; Mason, Kevin M

    2016-03-01

    A thorough understanding of the molecular details of the interactions between bacteria and host are critical to ultimately prevent disease. Recent technological advances allow simultaneous analysis of host and bacterial protein and metabolic profiles from a single small tissue sample to provide insight into pathogenesis. We used the chinchilla model of human otitis media to determine, for the first time, the most expansive delineation of global changes in protein and metabolite profiles during an experimentally induced disease. After 48 h of infection with nontypeable Haemophilus influenzae, middle ear tissue lysates were analyzed by high-resolution quantitative two-dimensional liquid chromatography-tandem mass spectrometry. Dynamic changes in 105 chinchilla proteins and 66 metabolites define the early proteomic and metabolomic signature of otitis media. Our studies indicate that establishment of disease coincides with actin morphogenesis, suppression of inflammatory mediators, and bacterial aerobic respiration. We validated the observed increase in the actin-remodeling complex, Arp2/3, and experimentally showed a role for Arp2/3 in nontypeable Haemophilus influenzae invasion. Direct inhibition of actin branch morphology altered bacterial invasion into host epithelial cells, and is supportive of our efforts to use the information gathered to modify outcomes of disease. The twenty-eight nontypeable Haemophilus influenzae proteins identified participate in carbohydrate and amino acid metabolism, redox homeostasis, and include cell wall-associated metabolic proteins. Quantitative characterization of the molecular signatures of infection will redefine our understanding of host response driven developmental changes during pathogenesis. These data represent the first comprehensive study of host protein and metabolite profiles in vivo in response to infection and show the feasibility of extensive characterization of host protein profiles during disease. Identification of

  15. A plant natriuretic peptide-like gene in the bacterial pathogen Xanthomonas axonopodis may induce hyper-hydration in the plant host: a hypothesis of molecular mimicry

    Directory of Open Access Journals (Sweden)

    Sayed Muhammed

    2004-03-01

    Full Text Available Abstract Background Plant natriuretic peptides (PNPs are systemically mobile molecules that regulate homeostasis at nanomolar concentrations. PNPs are up-regulated under conditions of osmotic stress and PNP-dependent processes include changes in ion transport and increases of H2O uptake into protoplasts and whole tissue. Presentation of the hypothesis The bacterial citrus pathogen Xanthomonas axonopodis pv. Citri str. 306 contains a gene encoding a PNP-like protein. We hypothesise that this bacterial protein can alter plant cell homeostasis and thus is likely to represent an example of molecular mimicry that enables the pathogen to manipulate plant responses in order to bring about conditions favourable to the pathogen such as the induced plant tissue hyper-hydration seen in the wet edged lesions associated with Xanthomonas axonopodis infection. Testing the hypothesis We found a Xanthomonas axonopodis PNP-like protein that shares significant sequence similarity and identical domain organisation with PNPs. We also observed a significant excess of conserved residues between the two proteins within the domain previously identified as being sufficient to induce biological activity. Structural modelling predicts identical six stranded double-psi β barrel folds for both proteins thus supporting the hypothesis of similar modes of action. No significant similarity between the Xanthomonas axonopodis protein and other bacterial proteins from GenBank was found. Sequence similarity of the Xanthomonas axonopodis PNP-like protein with the Arabidopsis thaliana PNP (AtPNP-A, shared domain organisation and incongruent phylogeny suggest that the PNP-gene may have been acquired by the bacteria in an ancient lateral gene transfer event. Finally, activity of a recombinant Xanthomonas axonopodis protein in plant tissue and changes in symptoms induced by a Xanthomonas axonopodis mutant with a knocked-out PNP-like gene will be experimental proof of molecular mimicry

  16. A new pharmacological agent (AKB-4924) stabilizes hypoxia inducible factor-1 (HIF-1) and increases skin innate defenses against bacterial infection.

    Science.gov (United States)

    Okumura, Cheryl Y M; Hollands, Andrew; Tran, Dan N; Olson, Joshua; Dahesh, Samira; von Köckritz-Blickwede, Maren; Thienphrapa, Wdee; Corle, Courtney; Jeung, Seung Nam; Kotsakis, Anna; Shalwitz, Robert A; Johnson, Randall S; Nizet, Victor

    2012-09-01

    Hypoxia inducible factor-1 (HIF-1) is a transcription factor that is a major regulator of energy homeostasis and cellular adaptation to low oxygen stress. HIF-1 is also activated in response to bacterial pathogens and supports the innate immune response of both phagocytes and keratinocytes. In this work, we show that a new pharmacological compound AKB-4924 increases HIF-1 levels and enhances the antibacterial activity of phagocytes and keratinocytes against both methicillin-sensitive and methicillin-resistant strains of Staphylococcus aureus in vitro. AKB-4924 is also effective in stimulating the killing capacity of keratinocytes against the important opportunistic skin pathogens Pseudomonas aeruginosa and Acinetobacter baumanii. The effect of AKB-4924 is mediated through the activity of host cells, as the compound exerts no direct antimicrobial activity. Administered locally as a single agent, AKB-4924 limits S. aureus proliferation and lesion formation in a mouse skin abscess model. This approach to pharmacologically boost the innate immune response via HIF-1 stabilization may serve as a useful adjunctive treatment for antibiotic-resistant bacterial infections. PMID:22371073

  17. HrpNEa -induced deterrent effect on phloem feeding of the green peach aphid Myzus persicae requires AtGSL5 and AtMYB44 genes in Arabidopsis thaliana

    Indian Academy of Sciences (India)

    Beibei Lü; Weiwei Sun; Shuping Zhang; Chunling Zhang; Jun Qian; Xiaomeng Wang; Rong Gao; Hansong Dong

    2011-03-01

    In Arabidopsis thaliana (Arabidopsis) treated with the harpin protein HrpNEa, resistance to the green peach aphid Myzus persicae, a generalist phloem-feeding insect, develops with induced expression of the AtMYB44 gene. Special GLUCAN SYNTHESIS-LIKE (GSL) genes and -1,3-glucan callose play an important role in plant defence responses to attacks by phloem-feeding insects. Here we report that AtGLS5 and AtMYB44 are both required for HrpNEa-induced repression of M. persicae feeding from the phloem of Arabidopsis leaves. In 24 h successive surveys on large-scale aphid populations, the proportion of feeding aphids was much smaller in HrpNEa-treated plants than in control plants, and aphids preferred to feed from the 37 tested atgsl mutants rather than the wild-type plant. The atgsl mutants were generated previously by mutagenesis in 12 identified AtGSL genes (AtGSL1 through AtGSL12); in the 24 h survey, both atgsl5 and atgsl6 tolerated aphid feeding, and atgsl5 was the most tolerant. Consistently, atgsl5 was also most inhibitive to the deterrent effect of HrpNEa on the phloem-feeding activity of aphids as monitored by the electrical penetration graph technique. These results suggested an important role of the AtGSL5 gene in the effect of HrpNEa. In response to HrpNEa, AtGSL5 expression and callose deposition were induced in the wild-type plant but not in atgsl5. In response to HrpNEa, moreover, the AtMYB44 gene known to be required for repression of aphid reproduction on the plant was also required for repression of the phloem-feeding activity. Small amounts of the AtGSL5 transcript and callose deposition were detected in the atmyb44 mutant, as in atgsl5. Both mutants performed similarly in tolerating the phloem-feeding activity and impairing the deterrent effect of HrpNEa, suggesting that AtGSL5 and AtMYB44 both contributed to the effect.

  18. Do titanium dioxide nanoparticles induce food depletion for filter feeding organisms? A case study with Daphnia magna.

    Science.gov (United States)

    Bundschuh, Mirco; Vogt, Roland; Seitz, Frank; Rosenfeldt, Ricki R; Schulz, Ralf

    2016-07-01

    Although nanoparticles are increasingly investigated, their impact on the availability of food (i.e., algae) at the bottom of food chains remains unclear. It is, however, assumed that algae, which form heteroagglomerates with nanoparticles, sediment quickly limiting the availability of food for primary consumers such as Daphnia magna. As a consequence, it may be hypothesized that this scenario - in case of fundamental importance for the nanoparticles impact on primary consumers - induces a similar pattern in the life history strategy of daphnids relative to situations of food depletion. To test this hypothesis, the present study compared the life-history strategy of D. magna experiencing different degrees of food limitation as a consequence of variable algal density with daphnids fed with heteroagglomerates composed of algae and titanium dioxide nanoparticles (nTiO2). In contrast to the hypothesis, daphnids' body length, weight, and reproduction increased when fed with these heteroagglomerates, while the opposite pattern was observed under food limitation scenarios. Moreover, juvenile body mass, and partly length, was affected negatively irrespective of the scenarios. This suggests that daphnids experienced - besides a limitation in the food availability - additional stress when fed with heteroagglomerates composed of algae and nTiO2. Potential explanations include modifications in the nutritious quality of algae but also an early exposure of juveniles to nTiO2. PMID:27155102

  19. Bacterial lipoprotein-induced self-tolerance and cross-tolerance to LPS are associated with reduced IRAK-1 expression and MyD88-IRAK complex formation.

    LENUS (Irish Health Repository)

    Li, Chong Hui

    2012-02-03

    Tolerance to bacterial cell-wall components may represent an essential regulatory mechanism during bacterial infection. We have demonstrated previously that the inhibition of nuclear factor (NF)-kappaB and mitogen-activated protein kinase activation was present in bacterial lipoprotein (BLP) self-tolerance and its cross-tolerance to lipopolysaccharide (LPS). In this study, the effect of BLP-induced tolerance on the myeloid differentiation factor 88 (MyD88)-dependent upstream signaling pathway for NF-kappaB activation in vitro was examined further. When compared with nontolerant human monocytic THP-1 cells, BLP-tolerant cells had a significant reduction in tumor necrosis factor alpha (TNF-alpha) production in response to a high-dose BLP (86+\\/-12 vs. 6042+\\/-245 ng\\/ml, P < 0.01) or LPS (341+\\/-36 vs. 7882+\\/-318 ng\\/ml, P < 0.01) stimulation. The expression of Toll-like receptor 2 (TLR2) protein was down-regulated in BLP-tolerant cells, whereas no significant differences in TLR4, MyD88, interleukin-1 receptor-associated kinase 4 (IRAK-4), and TNF receptor-associated factor 6 expression were observed between nontolerant and BLP-tolerant cells, as confirmed by Western blot analysis. The IRAK-1 protein was reduced markedly in BLP-tolerant cells, although IRAK-1 mRNA expression remained unchanged as revealed by real-time reverse transcriptase-polymerase chain reaction analysis. Furthermore, decreased MyD88-IRAK immunocomplex formation, as demonstrated by immunoprecipitation, was observed in BLP-tolerant cells following a second BLP or LPS stimulation. BLP pretreatment also resulted in a marked inhibition in total and phosphorylated inhibitor of kappaB-alpha (IkappaB-alpha) expression, which was not up-regulated by subsequent BLP or LPS stimulation. These results demonstrate that in addition to the down-regulation of TLR2 expression, BLP tolerance is associated with a reduction in IRAK-1 expression, MyD88-IRAK association, and IkappaB-alpha phosphorylation. These

  20. Biochemical changes induced by salt stress in halotolerant bacterial isolates are media dependent as well as species specific.

    Science.gov (United States)

    Joghee, Nidhya Nadarajan; Jayaraman, Gurunathan

    2016-01-01

    Halophilic bacteria respond to salt stress by regulating the cytosolic pools of organic solutes to achieve osmotic equilibrium. In order to understand the metabolic regulation of these organic solutes, for the first time, we have investigated the effect of salt on growth and biochemical changes in four major moderately halophilic bacterial strains isolated from a saltern region of the Kumta coast, India. The strains under study were Halomonas hydrothermalis VITP9, Bacillus aquimaris VITP4, Planococcus maritimus VITP21, and Virgibacillus dokdonensis VITP14, which exhibited similar salt tolerance (0% to 10% w/v NaCl) with optimal growth at 5% w/v NaCl. Biochemical analysis showed that the total intracellular organic solutes increased significantly with increasing NaCl concentration in the growth medium, and the compositions of the solutes were dependent on the type of strain and also on the nutrient richness of the growth medium. Glutamic acid levels increased in all the strains under salt stress, indicating the significance of glutamic acid as the anionic counterpart of K(+)/Na(+) ions and precursor for other synthesized nitrogenous osmolytes. Though initial studies were performed with thin-layer chromatography, mass spectrometry was used to identify the major solutes accumulated by the strains under salt stress, such as proline (VITP4), ectoine (VITP14 and VITP9), and sugars (VITP21) under minimal medium and glycine betaine (by all the strains under study) under complex growth medium conditions. Such comparative study on the stress-dependent metabolic differences of different microbes, under identical experimental condition, helps to identify possible bacterial sources for the production of industrially important solutes. PMID:25286020

  1. Effect of Bacterial Lipopolysaccharide Contamination on Gutta Percha- versus Resilon-Induced Human Monocyte Cell Line Toxicity.

    Directory of Open Access Journals (Sweden)

    Jamshid Hadjati

    2015-04-01

    Full Text Available Cytotoxic effects of obturation materials were tested in presence and absence of endotoxin on human monocytes in vitro.Human monocytes from THP-1 cell line were cultured. Three millimeters from the tip of each Resilon and gutta percha points were cut and directly placed at the bottom of the culture wells. Cultured cells were exposed to gutta percha (groups G1 and G2 and Resilon (R1 and R2. Ten μg/ml bacterial lipopolysaccharide (LPS was added to the culture wells in groups G1 and R1. Positive control included the bacterial LPS without the root canal filling material and the negative control contained the cells in culture medium only. Viability of cells was tested in all groups after 24, 48, and 72 hours using the methylthiazolyldiphenyl-tetrazolium bromide (MTT assay for at least 3 times to obtain reproducible results. Optical density values were read and the data were analyzed using three-way ANOVA and post hoc statistical test.The results showed that cells in G2 had the lowest rate of viability at 24 hours, but the lowest rate of viable cells was recorded in G1 at 48 and 72 hours. The effect of LPS treatment was not statistically significant. Resilon groups showed cell viability values higher than those of gutta percha groups, although statistically non-significant (P=0.105. Cell viability values were lower in gutta percha than Resilon groups when LPS-treated and LPS-untreated groups were compared independently at each time point.It could be concluded that none of the tested root canal filling materials had toxic effects on cultured human monocyte cells whether in presence or absence of LPS contamination.

  2. Vaccination with Brucella abortus recombinant in vivo-induced antigens reduces bacterial load and promotes clearance in a mouse model for infection.

    Directory of Open Access Journals (Sweden)

    Jake E Lowry

    Full Text Available Current vaccines used for the prevention of brucellosis are ineffective in inducing protective immunity in animals that are chronically infected with Brucella abortus, such as elk. Using a gene discovery approach, in vivo-induced antigen technology (IVIAT on B. abortus, we previously identified ten loci that encode products up-regulated during infection in elk and consequently may play a role in virulence. In our present study, five of the loci (D15, 0187, VirJ, Mdh, AfuA were selected for further characterization and compared with three additional antigens with virulence potential (Hia, PrpA, MltA. All eight genes were PCR-amplified from B. abortus and cloned into E. coli. The recombinant products were then expressed, purified, adjuvanted, and delivered subcutaneously to BALB/c mice. After primary immunization and two boosts, mice were challenged i.p. with 5 x 10⁴ CFU of B. abortus strain 19. Spleens from challenged animals were harvested and bacterial loads determined by colony count at various time points. While vaccination with four of the eight individual proteins appeared to have some effect on clearance kinetics, mice vaccinated with recombinant Mdh displayed the most significant reduction in bacterial colonization. Furthermore, mice immunized with Mdh maintained higher levels of IFN-γ in spleens compared to other treatment groups. Collectively, our in vivo data gathered from the S19 murine colonization model suggest that vaccination with at least three of the IVIAT antigens conferred an enhanced ability of the host to respond to infection, reinforcing the utility of this methodology for the identification of potential vaccine candidates against brucellosis. Mechanisms for immunity to one protein, Mdh, require further in vitro exploration and evaluation against wild-type B. abortus challenge in mice, as well as other hosts. Additional studies are being undertaken to clarify the role of Mdh and other IVI antigens in B. abortus virulence

  3. Vaccination with Brucella abortus recombinant in vivo-induced antigens reduces bacterial load and promotes clearance in a mouse model for infection.

    Science.gov (United States)

    Lowry, Jake E; Isaak, Dale D; Leonhardt, Jack A; Vernati, Giulia; Pate, Jessie C; Andrews, Gerard P

    2011-01-01

    Current vaccines used for the prevention of brucellosis are ineffective in inducing protective immunity in animals that are chronically infected with Brucella abortus, such as elk. Using a gene discovery approach, in vivo-induced antigen technology (IVIAT) on B. abortus, we previously identified ten loci that encode products up-regulated during infection in elk and consequently may play a role in virulence. In our present study, five of the loci (D15, 0187, VirJ, Mdh, AfuA) were selected for further characterization and compared with three additional antigens with virulence potential (Hia, PrpA, MltA). All eight genes were PCR-amplified from B. abortus and cloned into E. coli. The recombinant products were then expressed, purified, adjuvanted, and delivered subcutaneously to BALB/c mice. After primary immunization and two boosts, mice were challenged i.p. with 5 x 10⁴ CFU of B. abortus strain 19. Spleens from challenged animals were harvested and bacterial loads determined by colony count at various time points. While vaccination with four of the eight individual proteins appeared to have some effect on clearance kinetics, mice vaccinated with recombinant Mdh displayed the most significant reduction in bacterial colonization. Furthermore, mice immunized with Mdh maintained higher levels of IFN-γ in spleens compared to other treatment groups. Collectively, our in vivo data gathered from the S19 murine colonization model suggest that vaccination with at least three of the IVIAT antigens conferred an enhanced ability of the host to respond to infection, reinforcing the utility of this methodology for the identification of potential vaccine candidates against brucellosis. Mechanisms for immunity to one protein, Mdh, require further in vitro exploration and evaluation against wild-type B. abortus challenge in mice, as well as other hosts. Additional studies are being undertaken to clarify the role of Mdh and other IVI antigens in B. abortus virulence and induction of

  4. Bacterial Vaginosis

    Science.gov (United States)

    ... 586. Related Content STDs during Pregnancy Fact Sheet Pregnancy and HIV, Viral Hepatitis, and STD Prevention Pelvic Inflammatory Disease ( ... Bacterial Vaginosis (BV) Chlamydia Gonorrhea Genital Herpes Hepatitis HIV/AIDS & STDs Human Papillomavirus ... STDs See Also Pregnancy Reproductive ...

  5. Bacterial Meningitis

    Science.gov (United States)

    ... Schedules Preteen & Teen Vaccines Meningococcal Disease Sepsis Bacterial Meningitis Recommend on Facebook Tweet Share Compartir On this ... serious disease. Laboratory Methods for the Diagnosis of Meningitis This manual summarizes laboratory methods used to isolate, ...

  6. Prostatitis - bacterial

    Science.gov (United States)

    Any bacteria that can cause a urinary tract infection can cause acute bacterial prostatitis. Infections spread through sexual contact can cause prostatitis. These include chlamydia and gonorrhea . Sexually transmitted ...

  7. FEED FORMULATION AND FEEDING TECHNOLOGY FOR FISHES

    Directory of Open Access Journals (Sweden)

    Govind Pandey

    2013-03-01

    Full Text Available Most fish farmers and ornamental fish hobbyists buy the bulk of their feed from commercial manufacturers. However, small quantities of specialized feeds are often needed for experimental purposes, feeding difficult-to maintain aquarium fishes, larval or small juvenile fishes, brood fish conditioning, or administering medication to sick fish. Small ornamental fish farms with an assortment of fish require small amounts of various diets with particular ingredients. It is not cost effective for commercial manufacturers to produce very small quantities of specialized feeds. Most feed mills will only produce custom formulations in quantities of more than one ton, and medicated feeds are usually sold in 50-pound bags. Small fish farmers, hobbyists and laboratory technicians are, therefore, left with the option of buying large quantities of expensive feed, which often goes to waste. Small quantities of fish feeds can be made quite easily in the laboratory, classroom, or at home, with common ingredients and simple kitchen or laboratory equipment. Hence, this review provides the knowledge about the fish feed formulation and feeding technology concerned with the live feed for fish larvae, fish feeds, fish feed ingredients, common fish feed stuffs, animal and plant sources of feeds for culture fish, and fish feeding methods.

  8. Water-Soluble Chitosan Nanoparticles Inhibit Hypercholesterolemia Induced by Feeding a High-Fat Diet in Male Sprague-Dawley Rats

    International Nuclear Information System (INIS)

    Chitosan, a deacetylated product of chitin, has been demonstrated to lower cholesterol in humans and animals. However, chitosan is not fully soluble in water which would influence absorption in the human intestine. In addition, water-soluble chitosan (WSC) has higher reactivity compared to chitosan. The present study was designed to clarify the effects of WSC and water-soluble chitosan nanoparticles (WSC-NPs) on hypercholesterolemia induced by feeding a high-fat diet in male Sprague-Dawley rats. WSC-NPs were prepared by the ionic gelation method and the spray-drying technique. The nanoparticles were spherical in shape and had a smooth surface. The mean size of WSC-NPs was 650 nm variing from 500 to 800?nm. Results showed that WSC-NPs reduced the blood lipids and plasma viscosity significantly and increased the serum superoxide dismutase (SOD) activities significantly. This paper is the first report of the lipid-lowering effects of WSC-NPs suggesting that the WSC-NPs could be used for the treatment of hypercholesterolemia

  9. Bacterial Conjunctivitis

    OpenAIRE

    Köhle, Ülkü; Kükner, Şahap

    2003-01-01

    Conjunctivitis is an infection of the conjunctiva, generally characterized by irritation, itching, foreign body sensation, tearing and discharge. Bacterial conjunctivitis may be distinguished from other types of conjunctivitis by the presence of yellow–white mucopurulent discharge. It is the most common form of ocular infection all around the world. Staphylococcus species are the most common bacterial pathogenes, followed by Streptococcus pneumoniae and Haemophilus i...

  10. Green synthesis of bacterial mediated anti-proliferative gold nanoparticles: inducing mitotic arrest (G2/M phase) and apoptosis (intrinsic pathway)

    Science.gov (United States)

    Ganesh Kumar, C.; Poornachandra, Y.; Chandrasekhar, Cheemalamarri

    2015-11-01

    The physiochemical and biological properties of microbial derived gold nanoparticles have potential applications in various biomedical domains as well as in cancer therapy. We have fabricated anti-proliferative bacterial mediated gold nanoparticles (b-Au NPs) using a culture supernatant of Streptomyces clavuligerus and later characterized them by UV-visible, TEM, DLS, XRD and FT-IR spectroscopic techniques. The capping agent responsible for the nanoparticle formation was characterized based on SDS-PAGE and MALDI-TOF-MS analyses. They were tested for anticancer activity in A549, HeLa and DU145 cell lines. The biocompatibility and non-toxic nature of the nanoparticles were tested on normal human lung cell line (MRC-5). The b-Au NPs induced the cell cycle arrest in G2/M phase and also inhibited the microtubule assembly in DU145 cells. Mechanistic studies, such as ROS, MMP, Cyt-c, GSH, caspases 9, 8 and 3 activation and the Annexin V-FITC staining, along with the above parameters tested provided sufficient evidence that the b-Au NPs induced apoptosis through the intrinsic pathway. The results supported the use of b-Au NPs for future therapeutic application in cancer therapy and other biomedical applications.The physiochemical and biological properties of microbial derived gold nanoparticles have potential applications in various biomedical domains as well as in cancer therapy. We have fabricated anti-proliferative bacterial mediated gold nanoparticles (b-Au NPs) using a culture supernatant of Streptomyces clavuligerus and later characterized them by UV-visible, TEM, DLS, XRD and FT-IR spectroscopic techniques. The capping agent responsible for the nanoparticle formation was characterized based on SDS-PAGE and MALDI-TOF-MS analyses. They were tested for anticancer activity in A549, HeLa and DU145 cell lines. The biocompatibility and non-toxic nature of the nanoparticles were tested on normal human lung cell line (MRC-5). The b-Au NPs induced the cell cycle arrest in G2

  11. Protective Capacity of Resveratrol, a Natural Polyphenolic Compound, against Deoxynivalenol-Induced Intestinal Barrier Dysfunction and Bacterial Translocation.

    Science.gov (United States)

    Ling, Ka-Ho; Wan, Murphy Lam Yim; El-Nezami, Hani; Wang, Mingfu

    2016-05-16

    Contamination of food/feedstuffs by mycotoxins is a serious problem worldwide, causing severe economic losses and serious health problems in animals/humans. Deoxynivalenol (DON) is a major mycotoxin contaminant and is known to impair intestinal barrier function. Grapes and red wine are rich in polyphenols, such as resveratrol (RES), which has striking antioxidant and anti-inflammatory activities. RES is a food-derived component; therefore, it may be simultaneously present with DON in the gastrointestinal tract. The aim of this study was to explore in vitro protective effects of RES against DON-induced intestinal damage. The results showed that RES could protect DON-induced bacteria translocation because of enhanced of intestinal barrier function by restoring the DON-induced decrease in transepithelial electrical resistance and increase in paracellular permeability. Further mechanistic studies demonstrated that RES protects against DON-induced barrier dysfunction by promoting the assembly of claudin-4 in the tight junction complex. This is probably mediated through modulation of IL-6 and IL-8 secretion via mitogen-activated protein kinase-dependent pathways. Our results imply that RES can protect against DON-induced intestinal damage and that RES may be used as a novel dietary intervention strategy to reduce DON toxicity in animals/humans. PMID:27058607

  12. Gamma Irradiation-Induced Mutation for the Improvement of Josapine Pineapple Against Bacterial Heart Rot Disease and Improved Fruit Quality

    International Nuclear Information System (INIS)

    Bacterial heart rot disease, caused by Erwinia chrysanthemi, is one of the most serious diseases of the susceptible cultivars of pineapple in Malaysia, namely, Josapine, Sarawak, Gandul and N36. Using acute irradiation of Gamma-rays and in vitro cultured meristems, selection of resistant mutants to bacterial heart rot disease with improved fruit quality has been carried out in the most popular variety, Josapine. Suckers were collected from the experimental field plot at MARDI Research Station in Pontian Johor. Explants from meristem tissues were transferred to MS (Murashige and Skoog) solid media with 2.5mg/l benzyl aminopurine (BA) and incubated at 23oC at a 16-hour photoperiod. After 10 days in culture, meristem explants were irradiated with a series of Gamma-ray doses of 0, 20, 40, 60, 80, 100, 120, 140 and 160Gy and radiosensitivity was investigated based on shoot formation and survival rate. Radiosensitivity of meristem tissues producing shoots was inversely proportional to the irradiation dose. As the dose was increased mutations appeared more frequently, indicated by the formation of albino and striped leaves. The dose required for 50% lethality (LD50) and 100% (LD100) of meristem tissues for shoot formation were 40Gy and 83Gy, respectively. On the other hand, the LD50 and LD100 for survival rate were 77Gy and 147Gy, respectively. Suitable doses for mutation induction are suggested in the lower region alongside with LD50 curve, where multiple shoots are regenerated from the irradiated meristem tissues. Therefore, for field screening, four lower doses of gamma irradiation viz. 10, 20, 30 and 40Gy were applied. The limit for shoot induction from irradiated explants generally agreed with the LD100 curve. Shoots derived from irradiated meristem explants at 10, 20, 30 and 40Gy were sub-cultured up to M1V5 to minimize chimerism. Multiplication of irradiated shoots was carried out in Temporary Immersion Bioreactor System using MS liquid media with 5 mg/l BA and

  13. Transition from parenteral to enteral nutrition induces immediate diet-dependent gut histological and immunological responses in preterm neonates.

    Science.gov (United States)

    Siggers, Jayda; Sangild, Per T; Jensen, Tim K; Siggers, Richard H; Skovgaard, Kerstin; Støy, Ann Cathrine F; Jensen, Bent B; Thymann, Thomas; Bering, Stine B; Boye, Mette

    2011-09-01

    Necrotizing enterocolitis (NEC) in preterm infants develops very rapidly from a mild intolerance to enteral feeding into intestinal mucosal hemorrhage, inflammation, and necrosis. We hypothesized that immediate feeding-induced gut responses precede later clinical NEC symptoms in preterm pigs. Fifty-six preterm pigs were fed total parenteral nutrition (TPN) for 48 h followed by enteral feeding for 0, 8, 17, or 34 h with either colostrum (Colos, n = 20) or formula (Form, n = 31). Macroscopic NEC lesions were detected in Form pigs throughout the enteral feeding period (20/31, 65%), whereas most Colos pigs remained protected (1/20, 5%). Just 8 h of formula feeding induced histopathological lesions, as evidenced by capillary stasis and necrosis, epithelial degeneration, edema, and mucosal hemorrhage. These immediate formula-induced changes were paralleled by decreased digestive enzyme activities (lactase and dipeptidylpeptidase IV), increased nutrient fermentation, and altered expression of innate immune defense genes such as interleukins (IL-1α, IL-6, IL-18), nitric oxide synthetase, tight junction proteins (claudins), Toll-like receptors (TLR-4), and TNF-α. In contrast, the first hours of colostrum feeding induced no histopathological lesions, increased maltase activity, and induced changes in gene expressions related to tissue development. Total bacterial density was high after 2 days of parenteral feeding and was not significantly affected by diet (colostrum, formula) or length of enteral feeding (8-34 h), except that a few bacterial groups (Clostridium, Enterococcus, Streptococcus species) increased with time. We conclude that a switch from parenteral to enteral nutrition rapidly induces diet-dependent histopathological, functional, and proinflammatory insults to the immature intestine. Great care is required when introducing enteral feeds to TPN-fed preterm infants, particularly when using formula, because early feeding-induced insults may predispose to NEC

  14. Chlor-alkali plant contamination of Aussa River sediments induced a large Hg-resistant bacterial community

    Science.gov (United States)

    Baldi, Franco; Marchetto, Davide; Gallo, Michele; Fani, Renato; Maida, Isabel; Covelli, Stefano; Fajon, Vesna; Zizek, Suzana; Hines, Mark; Horvat, Milena

    2012-11-01

    A closed chlor-alkali plant (CAP) discharged Hg for decades into the Aussa River, which flows into Marano Lagoon, resulting in the large-scale pollution of the lagoon. In order to get information on the role of bacteria as mercury detoxifying agents, analyses of anions in the superficial part (0-1 cm) of sediments were conducted at four stations in the Aussa River. In addition, measurements of biopolymeric carbon (BPC) as a sum of the carbon equivalent of proteins (PRT), lipids (LIP), and carbohydrates (CHO) were performed to correlate with bacterial biomass such as the number of aerobic heterotrophic cultivable bacteria and their percentage of Hg-resistant bacteria. All these parameters were used to assess the bioavailable Hg fraction in sediments and the potential detoxification activity of bacteria. In addition, fifteen isolates were characterized by a combination of molecular techniques, which permitted their assignment into six different genera. Four out of fifteen were Gram negative with two strains of Stenotrophomonas maltophilia, one Enterobacter sp., and one strain of Brevibacterium frigoritolerans. The remaining strains (11) were Gram positive belonging to the genera Bacillus and Staphylococcus. We found merA genes in only a few isolates. Mercury volatilization from added HgCl2 and the presence of plasmids with the merA gene were also used to confirm Hg reductase activity. We found the highest number of aerobic heterotrophic Hg-resistant bacteria (one order magnitude higher) and the highest number of Hg-resistant species (11 species out of 15) at the confluence of the River Aussa and Banduzzi's channel, which transport Hg from the CAP, suggesting that Hg is strongly detoxified [reduced to Hg(0)] at this location.

  15. Immunity induced shortly after DNA vaccination of rainbow trout against rhabdoviruses protects against heterologous virus but not against bacterial pathogens

    DEFF Research Database (Denmark)

    Lorenzen, Niels; Lorenzen, Ellen; Einer-Jensen, Katja; LaPatra, Scott E.

    2002-01-01

    It was recently reported that DNA vaccination of rainbow trout fingerlings against viral hemorrhagic septicaemia virus (VHSV) induced protection within 8 days after intramuscular injection of plasmid DNA. In order to analyse the specificity of this early immunity, fish were vaccinated with plasmid...... DNA encoding the VHSV or the infectious haematopoietic necrosis virus (IHNV) glycoprotein genes and later challenged with homologous or heterologous pathogens. Challenge experiments revealed that immunity established shortly after vaccination was cross-protective between the two viral pathogens...

  16. Human Langerhans cells control Th cells via programmed death-ligand 1 in response to bacterial stimuli and nickel-induced contact allergy.

    Directory of Open Access Journals (Sweden)

    Manuel Hitzler

    Full Text Available Langerhans cells (LCs are suspected to initiate inflammatory immune responses to contact allergens and pathogenic bacteria. In chronic infectious diseases, programmed death ligand (PD-L 1 exhibits both inhibitory and costimulatory functions on T cell-mediated activation and tolerance. Here, we investigated the effects of contact allergens and bacterial stimuli on PD-L1 expression in LCs and the effects of altered PD-L1 expression on cytokine release of subsequently cocultured T cells. Monocyte-derived LCs (MoLCs, LCs, and skin sections of patients suffering from allergic contact dermatitis were challenged with nickel and then analyzed for PD-L1 expression by confocal laser scanning microscopy and flow cytometry. In blocking experiments, we found that the release of Th cell specific cytokines was dependent on both stimulation of LCs and inhibition of PD-L1-PD-1 interactions. Stimulation with peptidoglycan (PGN or lipopolysaccharide (LPS and blockage of PD-L1 with a specific antibody triggered the release of high levels of IL-17, IL-22, TNF-α, and IFN-γ in CD4(+T cells. If nickel was used as a stimulus, blockage of PD-L1 led to high amounts of TNF-α and IL-22. A closer look revealed PD-L1-dependent upregulation of IL-17 secretion in FACS-sorted CCR6(+/CCR4(+ T memory cells. In the presence of anti-PD-L1, PGN induced secretion of IFN-γ and IL-17 in total CCR6(+ cells, while nickel triggered secretion of IFN-γ and IL-17 exclusively in CCR6(+/CCR4(+ cells. Our findings suggest that PD-L1 on LCs plays a crucial role in type IV allergic reactions and in response to bacterial stimuli by controlling the nature of inflammatory Th cell responses.

  17. Giardia duodenalis infection reduces granulocyte infiltration in an in vivo model of bacterial toxin-induced colitis and attenuates inflammation in human intestinal tissue.

    Directory of Open Access Journals (Sweden)

    James A Cotton

    Full Text Available Giardia duodenalis (syn. G. intestinalis, G. lamblia is a predominant cause of waterborne diarrheal disease that may lead to post-infectious functional gastrointestinal disorders. Although Giardia-infected individuals could carry as much as 106 trophozoites per centimetre of gut, their intestinal mucosa is devoid of overt signs of inflammation. Recent studies have shown that in endemic countries where bacterial infectious diseases are common, Giardia infections can protect against the development of diarrheal disease and fever. Conversely, separate observations have indicated Giardia infections may enhance the severity of diarrheal disease from a co-infecting pathogen. Polymorphonuclear leukocytes or neutrophils (PMNs are granulocytic, innate immune cells characteristic of acute intestinal inflammatory responses against bacterial pathogens that contribute to the development of diarrheal disease following recruitment into intestinal tissues. Giardia cathepsin B cysteine proteases have been shown to attenuate PMN chemotaxis towards IL-8/CXCL8, suggesting Giardia targets PMN accumulation. However, the ability of Giardia infections to attenuate PMN accumulation in vivo and how in turn this effect may alter the host inflammatory response in the intestine has yet to be demonstrated. Herein, we report that Giardia infection attenuates granulocyte tissue infiltration induced by intra-rectal instillation of Clostridium difficile toxin A and B in an isolate-dependent manner. This attenuation of granulocyte infiltration into colonic tissues paralled decreased expression of several cytokines associated with the recruitment of PMNs. Giardia trophozoite isolates that attenuated granulocyte infiltration in vivo also decreased protein expression of cytokines released from inflamed mucosal biopsy tissues collected from patients with active Crohn's disease, including several cytokines associated with PMN recruitment. These results demonstrate for the first time

  18. Biotechnological applications of bacterial cellulases

    OpenAIRE

    Esther Menendez; Paula Garcia-Fraile; Raul Rivas

    2015-01-01

    Cellulases have numerous applications in several industries, including biofuel production, food and feed industry, brewing, pulp and paper, textile, laundry, and agriculture.Cellulose-degrading bacteria are widely spread in nature, being isolated from quite different environments. Cellulose degradation is the result of a synergic process between an endoglucanase, an exoglucanase and a,β-glucosidase. Bacterial endoglucanases degrade ß-1,4-glucan linkages of cellulose amorphous zones, mean...

  19. Identification of an intestine-specific promoter and inducible expression of bacterial α-galactosidase in mammalian cells by a lac operon system

    Directory of Open Access Journals (Sweden)

    Ya-Feng Zhai

    2012-10-01

    Full Text Available Abstract Background α-galactosidase has been widely used in animal husbandry to reduce anti-nutritional factors (such as α-galactoside in feed. Intestine-specific and substrate inducible expression of α-galactosidase would be highly beneficial for transgenic animal production. Methods To achieve the intestine-specific and substrate inducible expression of α-galactosidase, we first identified intestine-specific promoters by comparing the transcriptional activity and tissue specificity of four intestine-specific promoters from human intestinal fatty acid binding protein, rat intestinal fatty acid binding protein, human mucin-2 and human lysozyme. We made two chimeric constructs combining the promoter and enhancer of human mucin-2, rat intestinal trefoil factor and human sucrase-isomaltase. Then a modified lac operon system was constructed to investigate the induction of α-galactosidase expression and enzyme activity by isopropyl β-D-1-thiogalactopyranoside (IPTG and an α-galactosidase substrate, α-lactose. We declared that the research carried out on human (Zhai Yafeng was in compliance with the Helsinki Declaration, and experimental research on animals also followed internationally recognized guidelines. Results The activity of the human mucin-2 promoter was about 2 to 3 times higher than that of other intestine-specific promoters. In the lac operon system, the repressor significantly decreased (P P Conclusions We have successfully constructed a high specificity inducible lac operon system in an intestine-derived cell line, which could be of great value for gene therapy applications and transgenic animal production.

  20. A study of oxidative stress induced by non-thermal plasma-activated water for bacterial damage

    International Nuclear Information System (INIS)

    Ar/O2 (2%) cold plasma microjet was used to create plasma-activated water (PAW). The disinfection efficacy of PAW against Staphylococcus aureus showed that PAW can effectively disinfect bacteria. Optical emission spectra and oxidation reduction potential results demonstrated the inactivation is attributed to oxidative stress induced by reactive oxygen species in PAW. Moreover, the results of X-ray photoelectron spectroscopy, atomic absorption spectrometry, and transmission electron microscopy suggested that the chemical state of cell surface, the integrity of cell membrane, as well as the cell internal components and structure were damaged by the oxidative stress.

  1. Bacterial Adhesion & Blocking Bacterial Adhesion

    DEFF Research Database (Denmark)

    Vejborg, Rebecca Munk

    2008-01-01

    parameters, which influence the transition from a planktonic lifestyle to a sessile lifestyle, have been studied. Protein conditioning film formation was found to influence bacterial adhesion and subsequent biofilm formation considerable, and an aqueous extract of fish muscle tissue was shown to...... tract to the microbial flocs in waste water treatment facilities. Microbial biofilms may however also cause a wide range of industrial and medical problems, and have been implicated in a wide range of persistent infectious diseases, including implantassociated microbial infections. Bacterial adhesion is...... the first committing step in biofilm formation, and has therefore been intensely scrutinized. Much however, still remains elusive. Bacterial adhesion is a highly complex process, which is influenced by a variety of factors. In this thesis, a range of physico-chemical, molecular and environmental...

  2. Bacterial lipases

    NARCIS (Netherlands)

    Jaeger, Karl-Erich; Ransac, Stéphane; Dijkstra, Bauke W.; Colson, Charles; Heuvel, Margreet van; Misset, Onno

    1994-01-01

    Many different bacterial species produce lipases which hydrolyze esters of glycerol with preferably long-chain fatty acids. They act at the interface generated by a hydrophobic lipid substrate in a hydrophilic aqueous medium. A characteristic property of lipases is called interfacial activation, mea

  3. Bacterial Ecology

    DEFF Research Database (Denmark)

    Fenchel, Tom

    2011-01-01

    Bacterial ecology is concerned with the interactions between bacteria and their biological and nonbiological environments and with the role of bacteria in biogeochemical element cycling. Many fundamental properties of bacteria are consequences of their small size. Thus, they can efficiently exploit...

  4. Breastfeeding vs. Formula Feeding

    Science.gov (United States)

    ... Things to Know About Zika & Pregnancy Breastfeeding vs. Formula Feeding KidsHealth > For Parents > Breastfeeding vs. Formula Feeding ... with a lactation specialist. previous continue All About Formula Feeding Commercially prepared infant formulas are a nutritious ...

  5. Action of Polymyxin B on Bacterial Membranes: Phosphatidylglycerol- and Cardiolipin-Induced Susceptibility to Polymyxin B in Acholeplasma laidlawii B

    Science.gov (United States)

    Teuber, Michael; Bader, Johann

    1976-01-01

    To identify the polymyxin receptor molecules in the membranes of living microorganisms, fusion of intact Acholeplasma laidlawii B with lipid vesicles was investigated according to the procedure of Grant and McConnell (1973). The naturally polymyxin-resistant A. laidlawii B was treated with phospholipid vesicles prepared from purified phospholipids of the polymyxin-susceptible Salmonella typhimurium G30. A. laidlawii B absorbed between 15 and 45% of its own lipid content of the added tritium-labeled phospholipids without loss of viability. Association with the acidic components phosphatidylglycerol and cardiolipin produced a 10- to 30-fold increase in polymyxin susceptibility, which was not obtained with egg-phosphatidylcholine and mixed phosphatidylcholine-phosphatidylethanolamine vesicles. The polymyxin-sensitized cells bound 12 times more radioactive antibiotic than resistant cells. The phosphatidylglycerol-induced susceptibility was abolished by serum fraction V (Cohn) proteins. PMID:176930

  6. IMPROVEMENT OF TECHNOLOGY OF WHEY-BASED FEED ADDITIVES WITH PROBIOTIC EFFECT USING BACTERIAL CONCENTRATES WITH CRYOFREEZING OF MICROBAL BIOMASS Совершенствование технологии кормовых добавок пробиотического действия на основе молочной сыворотки за счет использования бактериальных концентратов с криозамораживанием микробной биомассы

    OpenAIRE

    Shramko M. I.

    2011-01-01

    The article describes the biotechnology of bacterial concentrates with cryofreezing of microbal mass. Obtained bacterial concentrates are used in the production of whey-based feed additives with probiotic effect. Feed additives were tested on milk-fed calves within scientific experiments

  7. IMPROVEMENT OF TECHNOLOGY OF WHEY-BASED FEED ADDITIVES WITH PROBIOTIC EFFECT USING BACTERIAL CONCENTRATES WITH CRYOFREEZING OF MICROBAL BIOMASS Совершенствование технологии кормовых добавок пробиотического действия на основе молочной сыворотки за счет использования бактериальных концентратов с криозамораживанием микробной биомассы

    Directory of Open Access Journals (Sweden)

    Shramko M. I.

    2011-09-01

    Full Text Available The article describes the biotechnology of bacterial concentrates with cryofreezing of microbal mass. Obtained bacterial concentrates are used in the production of whey-based feed additives with probiotic effect. Feed additives were tested on milk-fed calves within scientific experiments

  8. Nucleotide-Induced Conformational Changes in Escherichia coli DnaA Protein Are Required for Bacterial ORC to Pre-RC Conversion at the Chromosomal Origin.

    Science.gov (United States)

    Saxena, Rahul; Vasudevan, Sona; Patil, Digvijay; Ashoura, Norah; Grimwade, Julia E; Crooke, Elliott

    2015-01-01

    DnaA oligomerizes when bound to origins of chromosomal replication. Structural analysis of a truncated form of DnaA from Aquifex aeolicus has provided insight into crucial conformational differences within the AAA+ domain that are specific to the ATP- versus ADP- bound form of DnaA. In this study molecular docking of ATP and ADP onto Escherichia coli DnaA, modeled on the crystal structure of Aquifex aeolicus DnaA, reveals changes in the orientation of amino acid residues within or near the vicinity of the nucleotide-binding pocket. Upon limited proteolysis with trypsin or chymotrypsin ADP-DnaA, but not ATP-DnaA generated relatively stable proteolytic fragments of various sizes. Examined sites of limited protease susceptibility that differ between ATP-DnaA and ADP-DnaA largely reside in the amino terminal half of DnaA. The concentration of adenine nucleotide needed to induce conformational changes, as detected by these protease susceptibilities of DnaA, coincides with the conversion of an inactive bacterial origin recognition complex (bORC) to a replication efficient pre-replication complex (pre-RC) at the E. coli chromosomal origin of replication (oriC). PMID:26610483

  9. Nucleotide-Induced Conformational Changes in Escherichia coli DnaA Protein Are Required for Bacterial ORC to Pre-RC Conversion at the Chromosomal Origin

    Directory of Open Access Journals (Sweden)

    Rahul Saxena

    2015-11-01

    Full Text Available DnaA oligomerizes when bound to origins of chromosomal replication. Structural analysis of a truncated form of DnaA from Aquifex aeolicus has provided insight into crucial conformational differences within the AAA+ domain that are specific to the ATP- versus ADP- bound form of DnaA. In this study molecular docking of ATP and ADP onto Escherichia coli DnaA, modeled on the crystal structure of Aquifex aeolicus DnaA, reveals changes in the orientation of amino acid residues within or near the vicinity of the nucleotide-binding pocket. Upon limited proteolysis with trypsin or chymotrypsin ADP-DnaA, but not ATP-DnaA generated relatively stable proteolytic fragments of various sizes. Examined sites of limited protease susceptibility that differ between ATP-DnaA and ADP-DnaA largely reside in the amino terminal half of DnaA. The concentration of adenine nucleotide needed to induce conformational changes, as detected by these protease susceptibilities of DnaA, coincides with the conversion of an inactive bacterial origin recognition complex (bORC to a replication efficient pre-replication complex (pre-RC at the E. coli chromosomal origin of replication (oriC.

  10. Salmonella typhi Ty21a bacterial ghost vector augments HIV-1 gp140 DNA vaccine-induced peripheral and mucosal antibody responses via TLR4 pathway.

    Science.gov (United States)

    Wen, Jing; Yang, Yi; Zhao, Guangyu; Tong, Shuang; Yu, Hong; Jin, Xia; Du, Lanying; Jiang, Shibo; Kou, Zhihua; Zhou, Yusen

    2012-08-24

    Because of their stability and ease of manipulation, DNA vaccines have considerable potential for eliciting immune responses. However, they are limited by their weak immunogenicity, especially in humans. To address this challenge, we explored a new strategy of HIV vaccine delivery using Salmonella typhi Ty21a bacterial ghosts (BGs). We found that Ty21a BGs loaded with an HIV gp140 DNA vaccine (Ty21a BG-DNA) were readily taken up by murine macrophage RAW264.7 cells, and gp140 was efficiently expressed in these cells. Peripheral and intestinal mucosal anti-gp120 antibody responses in mice vaccinated with BGs-DNA vaccine were significantly higher than those in mice immunized with naked DNA vaccine. The enhancement of antibody responses was associated with BG-induced production of IL-10 through TLR4 pathway. These results demonstrate that Ty21a BGs is a novel and effective delivery vehicle for DNA vaccines, which could therefore be used as a new strategy for development of HIV vaccines. PMID:22819719

  11. The peroxidase-mediated biodegradation of petroleum hydrocarbons in a H2O2-induced SBR using in-situ production of peroxidase: Biodegradation experiments and bacterial identification.

    Science.gov (United States)

    Shekoohiyan, Sakine; Moussavi, Gholamreza; Naddafi, Kazem

    2016-08-01

    A bacterial peroxidase-mediated oxidizing process was developed for biodegrading total petroleum hydrocarbons (TPH) in a sequencing batch reactor (SBR). Almost complete biodegradation (>99%) of high TPH concentrations (4g/L) was attained in the bioreactor with a low amount (0.6mM) of H2O2 at a reaction time of 22h. A specific TPH biodegradation rate as high as 44.3mgTPH/gbiomass×h was obtained with this process. The reaction times required for complete biodegradation of TPH concentrations of 1, 2, 3, and 4g/L were 21, 22, 28, and 30h, respectively. The catalytic activity of hydrocarbon catalyzing peroxidase was determined to be 1.48U/mL biomass. The biodegradation of TPH in seawater was similar to that in fresh media (no salt). A mixture of bacteria capable of peroxidase synthesis and hydrocarbon biodegradation including Pseudomonas spp. and Bacillus spp. were identified in the bioreactor. The GC/MS analysis of the effluent indicated that all classes of hydrocarbons could be well-degraded in the H2O2-induced SBR. Accordingly, the peroxidase-mediated process is a promising method for efficiently biodegrading concentrated TPH-laden saline wastewater. PMID:27060866

  12. Gamma radiation induced oxidative stress and apoptosis inhibiting properties of bacterial secondary metabolite RK-IP-006.G in J774A.1 murine cell line

    International Nuclear Information System (INIS)

    Redox imbalance due to radiation induced oxidation of vital bio-macromolecules activates inflammatory response cascade leading to cell death. In present study, bacterial secondary metabolite, RK-IP-006.G, was evaluated for its oxidative stress and apoptosis inhibiting activities in irradiated J774A.1 murine macrophage cell line. Radiation induced intracellular ROS generation and its inhibition upon RK-IP-006.G pretreatment was estimated using 2',7'dichlorodihydroflurescein diacetate (DCFDA). Modulation in mitochondrial membrane potential (MMP) in irradiated cells and its protection by RK-IP-006.G pretreatment was evaluated using Rhodamine-123. Modulation in protein expression in irradiated and RK-IP-006.G treated J774A.1 cells was assessed by SDS-PAGE. Compensatory effect of RK-IP-006.G treatment on TNF-α expression in irradiated cells was estimated using ELISA assay. APO-BrDU assay was performed to evaluate radiation-induced apoptosis in irradiated cells. Radiation-induced cell damage and protective ability of RK-IP-006.G was also evaluated using Differential Interference Contrast Microscopy. Results of the study indicated significant (p< 0.05) decrease in DCFDA fluorescence in irradiated cells that were pretreated (∼2h) with RK-IP-006.G (0.25 μg/ml) as compared to irradiated cells. Similarly, significant (p<0.05) decrease in MMP was observed in irradiated cells pretreated with RK-IP-006.G (0.25 μg/ml) as compared to only irradiated cells at 1 h time point. SDS-PAGE analysis clearly demonstrated up-regulation of some prominent proteins in irradiated cells pretreated with RK-IP-006.G at 2-4h after treatment as compared to irradiated control. Significant (p<0.05) down regulation in TNF-α expression was observed in irradiated cells that pretreated with RK-IP-006.G compared to irradiated controls. APO-BrDU assay revealed significant reduction in apoptosis in irradiated cells pretreated with RK-IP-006.G when compared to irradiated control. The findings

  13. p-Cresyl sulfate suppresses lipopolysaccharide-induced anti-bacterial immune responses in murine macrophages in vitro.

    Science.gov (United States)

    Shiba, Takahiro; Makino, Ikuyo; Kawakami, Koji; Kato, Ikuo; Kobayashi, Toshihide; Kaneko, Kimiyuki

    2016-03-14

    p-Cresyl sulfate (pCS) is a known uremic toxin that is metabolized from p-cresol produced by intestinal bacteria. Abnormal accumulation of pCS in the blood is a characteristic of chronic kidney disease (CKD). pCS is suggested to cause immune dysfunction and increase the risk of infectious diseases in CKD patients. In this study, we focused on the effects of pCS on macrophage functions related to host defense. We evaluated the effects of pCS on cytokine production, nitric oxide (NO) production, arginase activity, expression of cell-surface molecules, and phagocytosis in the macrophage-like cell line, RAW264.7. pCS significantly decreased interleukin (IL)-12 p40 production and increased IL-10 production. pCS also decreased NO production, but did not influence arginase activity. pCS suppressed lipopolysaccharide-induced CD40 expression on the cell surface, but did not influence phagocytosis. We further assessed whether the effects of pCS observed in the macrophage-like cell line were consistent in primary macrophages. Similar to RAW264.7 cells, pCS decreased IL-12 p40 and p70 production and increased IL-10 production in primary peritoneal macrophages. These data indicate that pCS suppresses certain macrophage functions that contribute to host defense, and may play a role in CKD-related immune dysfunction. PMID:26784855

  14. Role of Contact Lens Wear, Bacterial Flora, and Mannose-Induced Pathogenic Protease in the Pathogenesis of Amoebic Keratitis

    Science.gov (United States)

    Alizadeh, Hassan; Neelam, Sudha; Hurt, Michael; Niederkorn, Jerry Y.

    2005-01-01

    The ocular surface is continuously exposed to potential pathogens, including free-living amoebae. Acanthamoeba species are among the most ubiquitous amoebae, yet Acanthamoeba keratitis is remarkably rare. The pathogenesis of Acanthamoeba keratitis is a complex, sequential process. Here we show that Acanthamoeba keratitis is profoundly affected by mannosylated proteins on the ocular surface, which stimulate the amoebae to elaborate a 133-kDa pathogenic protease. The mannose-induced protease (MIP133) mediates apoptosis of the corneal epithelium, facilitates corneal invasion, and degrades the corneal stroma. We show that contact lens wear upregulates mannosylated proteins on the corneal epithelium, stimulates MIP133 secretion, and exacerbates corneal disease. Corynebacterium xerosis, a constituent of the ocular flora, contains large amounts of mannose and is associated with Acanthamoeba keratitis. The present results show that amoebae exposed to C. xerosis produce increased amounts of MIP133 and more severe corneal disease. Oral immunization with MIP133 mitigates Acanthamoeba keratitis and demonstrates the feasibility of antidisease vaccines for pathogens that resist immune elimination. PMID:15664950

  15. Phage-mediated dispersal of biofilm and distribution of bacterial virulence genes is induced by quorum sensing.

    Directory of Open Access Journals (Sweden)

    Friederike S Rossmann

    2015-02-01

    Full Text Available The microbiome and the phage meta-genome within the human gut are influenced by antibiotic treatments. Identifying a novel mechanism, here we demonstrate that bacteria use the universal communication molecule AI-2 to induce virulence genes and transfer them via phage release. High concentrations (i.e. 100 μM of AI-2 promote dispersal of bacteria from already established biofilms, and is associated with release of phages capable of infecting other bacteria. Enterococcus faecalis V583ΔABC harbours 7 prophages in its genome, and a mutant deficient in one of these prophages (i.e. prophage 5 showed a greatly reduced dispersal of biofilm. Infection of a probiotic E. faecalis strain without lytic prophages with prophage 5 resulted in increased biofilm formation and also in biofilm dispersal upon induction with AI-2. Infection of the probiotic E. faecalis strain with phage-containing supernatants released through AI-2 from E. faecalis V583ΔABC resulted in a strong increase in pathogenicity of this strain. The polylysogenic probiotic strain was also more virulent in a mouse sepsis model and a rat endocarditis model. Both AI-2 and ciprofloxacin lead to phage release, indicating that conditions in the gastrointestinal tract of hospitalized patients treated with antibiotics might lead to distribution of virulence genes to apathogenic enterococci and possibly also to other commensals or even to beneficial probiotic strains.

  16. Responses of three very large inducible GTPases to bacterial and white spot syndrome virus challenges in the giant fresh water prawn Macrobrachium rosenbergii.

    Science.gov (United States)

    Huang, Ying; Jin, Min; Yin, Shaowu; Ding, Zhengfeng; Wang, Wen; Ren, Qian

    2016-04-01

    Interferons (IFNs) are cytokines secreted by cells in response to invasion by pathogens, such as viruses, bacteria, parasites, or tumor cells. Very large inducible GTPases (VLIG) are the latest IFN-inducible GTPase family to be discovered and are the largest known GTPases of any species. However, VLIG proteins from invertebrates have yet to be characterized. In this study, three forms of VLIGs designated as MrVLIG1, MrVLIG2, and MrVLIG3 were cloned from the giant fresh water prawn Macrobrachium rosenbergii. MrVLIG1 has a 5445 bp open reading frame (ORF) encoding an 1814-amino acid protein. The complete nucleotide sequence of MrVLIG2 cDNA is 7055 bp long consisting of a 5757 bp ORF encoding a protein with 1918 amino acids. The full length of the MrVLIG3 gene consists of 5511 bp with a 3909 bp ORF encoding a peptide with 1302 amino acids. BLASTP and phylogenetic tree analyses showed that the three MrVLIGs are clustered into one subgroup and, together with other vertebrate VLIGs, into a branch. Tissue distribution analysis indicated that the mRNAs of the three MrVLIGs were widely expressed in almost all detected tissues, including the hemocytes, heart, hepatopancreas, gills, stomach, and intestine, with the highest expression in the hepatopancreas. They were also detected in the intestine but with relatively low expression levels. Quantitative real-time RT-PCR analysis showed that the mRNA transcripts of the MrVLIGs in the hepatopancreas were significantly expressed at various time points after infection with Vibrio parahaemolyticus and white spot syndrome virus. In summary, the three isoforms of VLIG genes participate in the innate immune response of the shrimps to bacterial and viral infections. PMID:26850335

  17. Cloning of the Koi Herpesvirus Genome as an Infectious Bacterial Artificial Chromosome Demonstrates That Disruption of the Thymidine Kinase Locus Induces Partial Attenuation in Cyprinus carpio koi▿

    Science.gov (United States)

    Costes, B.; Fournier, G.; Michel, B.; Delforge, C.; Raj, V. Stalin; Dewals, B.; Gillet, L.; Drion, P.; Body, A.; Schynts, F.; Lieffrig, F.; Vanderplasschen, A.

    2008-01-01

    Koi herpesvirus (KHV) is the causative agent of a lethal disease in koi and common carp. In the present study, we describe the cloning of the KHV genome as a stable and infectious bacterial artificial chromosome (BAC) clone that can be used to produce KHV recombinant strains. This goal was achieved by the insertion of a loxP-flanked BAC cassette into the thymidine kinase (TK) locus. This insertion led to a BAC plasmid that was stably maintained in bacteria and was able to regenerate virions when permissive cells were transfected with the plasmid. Reconstituted virions free of the BAC cassette but carrying a disrupted TK locus (the FL BAC-excised strain) were produced by the transfection of Cre recombinase-expressing cells with the BAC. Similarly, virions with a wild-type revertant TK sequence (the FL BAC revertant strain) were produced by the cotransfection of cells with the BAC and a DNA fragment encoding the wild-type TK sequence. Reconstituted recombinant viruses were compared to the wild-type parental virus in vitro and in vivo. The FL BAC revertant strain and the FL BAC-excised strain replicated comparably to the parental FL strain. The FL BAC revertant strain induced KHV infection in koi carp that was indistinguishable from that induced by the parental strain, while the FL BAC-excised strain exhibited a partially attenuated phenotype. Finally, the usefulness of the KHV BAC for recombination studies was demonstrated by the production of an ORF16-deleted strain by using prokaryotic recombination technology. The availability of the KHV BAC is an important advance that will allow the study of viral genes involved in KHV pathogenesis, as well as the production of attenuated recombinant candidate vaccines. PMID:18337580

  18. Estradiol-mediated increases in the anorexia induced by intraperitoneal injection of bacterial lipopolysaccharide in female rats.

    Science.gov (United States)

    Geary, Nori; Asarian, Lori; Sheahan, James; Langhans, Wolfgang

    2004-09-15

    Lipopolysaccharide (LPS) derived from the cell walls of gram-negative bacteria causes a robust acute phase response (APR) that includes fever, anorexia, and many other elements. Because immune system function, including some models of illness anorexia, is sexually differentiated, we investigated the sexual differentiation of the anorexia induced by intraperitoneal LPS injections in rats. Cycling female Long-Evans rats tested either during diestrus or estrus ate less following 6.25 microg/kg LPS than did intact males. Following 12.5 microg/kg LPS, females in estrus ate less than either females during diestrus or males. Similarly, a more pronounced anorexia occurred following 12.5, 25, and 50 microg/kg LPS in ovariectomized females that received cyclic estradiol treatment and were tested on the day modeling estrus than in untreated ovariectomized rats. LPS also increased the length of the rats' ovarian cycles, usually by a day, especially when injected during diestrus. As in male rats, when LPS injections were repeated in the same rats, both estradiol-treated and untreated rats failed to display any significant anorexia. The inhibitory effects of LPS on eating in intact and ovariectomized rats were expressed solely as decreases in spontaneous meal frequency, without significant alteration of spontaneous meal size. These data indicate that anorexia following peripheral LPS administration is sexually differentiated and that estradiol is sufficient to produce this response. The mechanism of the pathophysiological effect of estradiol on meal frequency appears to be different from the physiological effect of estradiol on food intake because the latter is expressed solely as a change in meal size. PMID:15276786

  19. [Bacterial vaginosis].

    Science.gov (United States)

    Romero Herrero, Daniel; Andreu Domingo, Antonia

    2016-07-01

    Bacterial vaginosis (BV) is the main cause of vaginal dysbacteriosis in the women during the reproductive age. It is an entity in which many studies have focused for years and which is still open for discussion topics. This is due to the diversity of microorganisms that cause it and therefore, its difficult treatment. Bacterial vaginosis is probably the result of vaginal colonization by complex bacterial communities, many of them non-cultivable and with interdependent metabolism where anaerobic populations most likely play an important role in its pathogenesis. The main symptoms are an increase of vaginal discharge and the unpleasant smell of it. It can lead to serious consequences for women, such as an increased risk of contracting sexually transmitted infections including human immunodeficiency virus and upper genital tract and pregnancy complications. Gram stain is the gold standard for microbiological diagnosis of BV, but can also be diagnosed using the Amsel clinical criteria. It should not be considered a sexually transmitted disease but it is highly related to sex. Recurrence is the main problem of medical treatment. Apart from BV, there are other dysbacteriosis less characterized like aerobic vaginitis of which further studies are coming slowly but are achieving more attention and consensus among specialists. PMID:27474242

  20. Bacterial lipopolysaccharide augments febrile-range hyperthermia-induced heat shock protein 70 expression and extracellular release in human THP1 cells.

    Directory of Open Access Journals (Sweden)

    Mohan E Tulapurkar

    Full Text Available Sepsis, a devastating and often lethal complication of severe infection, is characterized by fever and dysregulated inflammation. While infections activate the inflammatory response in part through Toll-like receptors (TLRs, fever can partially activate the heat shock response with generation of heat shock proteins (HSPs. Since extracellular HSPs, especially HSP70 (eHSP70, are proinflammatory TLR agonists, we investigated how exposure to the TLR4 agonist, bacterial lipopolysaccharide (LPS and febrile range hyperthermia (FRH; 39.5°C modify HSP70 expression and extracellular release. Using differentiated THP1 cells, we found that concurrent exposure to FRH and LPS as well as TLR2 and TLR3 agonists synergized to activate expression of inducible HSP72 (HSPA1A mRNA and protein via a p38 MAP kinase-requiring mechanism. Treatment with LPS for 6 h stimulated eHSP70 release; levels of eHSP70 released at 39.5°C were higher than at 37°C roughly paralleling the increase in intracellular HSP72 in the 39.5°C cells. By contrast, 6 h exposure to FRH in the absence of LPS failed to promote eHSP70 release. Release of eHSP70 by LPS-treated THP1 cells was inhibited by glibenclamide, but not brefeldin, indicating that eHSP70 secretion occurred via a non-classical protein secretory mechanism. Analysis of eHSP70 levels in exosomes and exosome-depleted culture supernatants from LPS-treated THP1 cells using ELISA demonstrated similar eHSP70 levels in unfractionated and exosome-depleted culture supernatants, indicating that LPS-stimulated eHSP70 release did not occur via the exosome pathway. Immunoblot analysis of the exosome fraction of culture supernatants from these cells showed constitutive HSC70 (HSPA8 to be the predominant HSP70 family member present in exosomes. In summary, we have shown that LPS stimulates macrophages to secrete inducible HSP72 via a non-classical non-exosomal pathway while synergizing with FRH exposure to increase both intracellular and

  1. Improving feed slurry rheology by colloidal techniques

    Energy Technology Data Exchange (ETDEWEB)

    Heath, W.O.; Ternes, R.L.

    1984-06-01

    Pacific Northwest Laboratory (PSN) has investigated three colloidal techniques in the laboratory to improve the sedimentation and flowability of Hanford simulated (nonradioactive) current acid waste (CAW) melter feed slurry: polymer-induced bridging flocculation; manipulating glass former (raw SiO/sub 2/ or frit) particle size; and alteration of nitric acid content. All three methods proved successful in improving the rheology of the simulated CAW feed. This initially had exhibited nearly worst-case flow and clogging properties, but was transformed into a flowable, resuspendable (nonclogging) feed. While each has advantages and disadvantages, the following three specific alternatives proved successful: addition of a polyelectrolyte in 2000 ppM concentration to feed slurry; substitution of a 49 wt % SiO/sub 2/ colloidal suspension (approx. 10-micron particle size) for the -325 mesh (less than or equal to 44-micron particle size) raw-chemical SiO/sub 2/; and increase of nitric acid content from the reference 1.06 M to optimum 1.35 M. The first method, polymer-induced bridging flocculation, results in a high sediment volume, nonclogging CAW feed. The second method, involving the use of colloidal silica particles results in a nonsedimenting feed that when left unagitated forms a gel. The third method, increase in feed acidity, results in a highly resuspendable (nonclogging) melter feed. Further research is therefore required to determine which of the three alternatives is the preferred method of achieving rheological control of CAW melter feeds.

  2. Bacterial colonization and gut development in preterm neonates

    DEFF Research Database (Denmark)

    Cilieborg, Malene S.; Boye, Mette; Sangild, Per Torp

    2012-01-01

    Necrotizing enterocolitis (NEC) develops in 5–10% of preterm infants in association with enteral feeding and bacterial colonization. It remains unclear how diet and bacteria interact to protect or provoke the immature gastrointestinal tract. Understanding the factors that control bacterial...

  3. FEED FORMULATION AND FEEDING TECHNOLOGY FOR FISHES

    OpenAIRE

    Govind Pandey

    2013-01-01

    Most fish farmers and ornamental fish hobbyists buy the bulk of their feed from commercial manufacturers. However, small quantities of specialized feeds are often needed for experimental purposes, feeding difficult-to maintain aquarium fishes, larval or small juvenile fishes, brood fish conditioning, or administering medication to sick fish. Small ornamental fish farms with an assortment of fish require small amounts of various diets with particular ingredients. It is not cost effective for c...

  4. Stressing fish in Recirculating Aquaculture Systems (RAS): Does stress induced in one group of fish affect the feeding motivation of other fish sharing the same RAS?

    NARCIS (Netherlands)

    Martins, C.I.; Eding, E.H.; Verreth, J.A.J.

    2011-01-01

    As a consequence of water re-use and high stocking densities, Recirculating Aquaculture Systems (RAS) may lead to an accumulation of substances released by the fish into the water, e.g. cortisol and alarm pheromones. This study investigated the effect of stressing fish on the feeding motivation of o

  5. Anti-Pseudomonas aeruginosa IgY Antibodies Induce Specific Bacterial Aggregation and Internalization in Human Polymorphonuclear Neutrophils

    DEFF Research Database (Denmark)

    Thomsen, K.; Christophersen, L.; Bjarnsholt, T.;

    2015-01-01

    P. aeruginosa by augmenting the phagocytic competence of PMNs may postpone the deteriorating chronic biofilm infection. Anti-P. aeruginosa IgY antibodies significantly increase the PMN-mediated respiratory burst and subsequent bacterial killing of P. aeruginosa in vitro. The mode of action is...... attributed to IgY-facilitated formation of immobilized bacteria in aggregates, as visualized by fluorescence microscopy andthe induction of increased bacterial hydrophobicity. Thus, the present study demonstrates that avian egg yolk immunoglobulins (IgY) targeting P. aeruginosa modify bacterial fitness...

  6. Microscopy of bacterial translocation during small bowel obstruction and ischemia in vivo – a new animal model

    Directory of Open Access Journals (Sweden)

    Hafner Mathias

    2002-08-01

    Full Text Available Abstract Background Existing animal models provide only indirect information about the pathogenesis of infections caused by indigenous gastrointestinal microflora and the kinetics of bacterial translocation. The aim of this study was to develop a novel animal model to assess bacterial translocation and intestinal barrier function in vivo. Methods In anaesthetized male Wistar rats, 0.5 ml of a suspension of green fluorescent protein-transfected E. coli was administered by intraluminal injection in a model of small bowel obstruction. Animals were randomly subjected to non-ischemic or ischemic bowel obstruction. Ischemia was induced by selective clamping of the terminal mesenteric vessels feeding the obstructed bowel loop. Time intervals necessary for translocation of E. coli into the submucosal stroma and the muscularis propria was assessed using intravital microscopy. Results Bacterial translocation into the submucosa and muscularis propria took a mean of 36 ± 8 min and 80 ± 10 min, respectively, in small bowel obstruction. Intestinal ischemia significantly accelerated bacterial translocation into the submucosa (11 ± 5 min, p E. coli were visible in frozen sections of small bowel, mesentery, liver and spleen taken two hours after E. coli administration. Conclusions Intravital microscopy of fluorescent bacteria is a novel approach to study bacterial translocation in vivo. We have applied this technique to define minimal bacterial transit time as a functional parameter of intestinal barrier function.

  7. Increased Production of Lysozyme Associated with Bacterial Proliferation in Barrett's Esophagitis, Chronic Gastritis, Gluten-induced Atrophic Duodenitis (Celiac Disease), Lymphocytic Colitis, Collagenous Colitis, Ulcerative Colitis and Crohn's Colitis.

    Science.gov (United States)

    Rubio, Carlos A

    2015-12-01

    The mucosa of the esophagus, the stomach, the small intestine, the large intestine and rectum are unremittingly challenged by adverse micro-environmental factors, such as ingested pathogenic and non-pathogenic bacteria, and harsh secretions with digestive properties with disparate pH, as well as bacteria and secretions from upstream GI organs. Despite the apparently inauspicious mixture of secretions and bacteria, the normal GI mucosa retains a healthy state of cell renewal. To by-pass the tough microenvironment, the epithelia of the GI react by speeding-up cell exfoliation, by increasing peristalsis, eliminating bacteria through secretion of plasma cell-immunoglobulins and by increasing production of natural antibacterial enzymes (lysozyme) and host defense peptides (defensin-5). Lysozyme was recently found up-regulated in Barrett's esophagitis, in chronic gastritis, in gluten-induced atrophic duodenitis (celiac disease), in collagenous colitis, in lymphocytic colitis and in Crohn's colitis. This up-regulation is a response directed towards the special types of bacteria thriving in the microenvironment in each of the aforementioned clinical inflammatory maladies. The purpose of that up-regulation is to protect the mucosa affected by the ongoing chronic inflammation. Bacterial antibiotic resistance continues to exhaust our supply of effective antibiotics. The future challenge is how to solve the increasing menace of bacterial resistance to anti-bacterial drugs. Further research on natural anti-bacterial enzymes such as lysozyme, appears mandatory. PMID:26637845

  8. Comparative effects of dietary nucleoside-nucleotide mixture and its components on endotoxin induced bacterial translocation and small intestinal injury in protein deficient mice.

    OpenAIRE

    Adjei, A A; Yamauchi, K.; Chan, Y. C.; Konishi, M; Yamamoto, S.

    1996-01-01

    BACKGROUND--Nucleoside-nucleotide mixture has been shown to improve gut morphology and reduce the incidence of bacterial translocation in protein deficient mice. AIMS--To compare the reparative effect of nucleoside-nucleotide mixture and their individual components on maintenance of gut integrity and bacterial translocation based on their differential metabolism and utilisation. METHODS--ICR (CD-1) mice were randomised into eight groups of 10 animals each and fed 20% casein diet (control), pr...

  9. Hypoxia-inducible Factor-dependent Regulation of Platelet-activating Factor Receptor as a Route for Gram-Positive Bacterial Translocation across Epithelia

    OpenAIRE

    Keely, Simon; Glover, Louise E.; Weissmueller, Thomas; MacManus, Christopher F.; Fillon, Sophie; Fennimore, Blair; Colgan, Sean P.

    2010-01-01

    Mucosal surfaces, such as the lung and intestine, are lined by a monolayer of epithelia that provides tissue barrier and transport function. It is recently appreciated that a common feature of inflammatory processes within the mucosa is hypoxia (so-called inflammatory hypoxia). Given the strong association between bacterial translocation and mucosal inflammatory disease, we hypothesized that intestinal epithelial hypoxia influences bacterial translocation. Initial studies revealed that exposu...

  10. Harpin-induced expression and transgenic overexpression of the phloem protein gene AtPP2-A1 in Arabidopsis repress phloem feeding of the green peach aphid Myzus persicae

    Directory of Open Access Journals (Sweden)

    Sun Weiwei

    2011-01-01

    Full Text Available Abstract Background Treatment of plants with HrpNEa, a protein of harpin group produced by Gram-negative plant pathogenic bacteria, induces plant resistance to insect herbivores, including the green peach aphid Myzus persicae, a generalist phloem-feeding insect. Under attacks by phloem-feeding insects, plants defend themselves using the phloem-based defense mechanism, which is supposed to involve the phloem protein 2 (PP2, one of the most abundant proteins in the phloem sap. The purpose of this study was to obtain genetic evidence for the function of the Arabidopsis thaliana (Arabidopsis PP2-encoding gene AtPP2-A1 in resistance to M. persicae when the plant was treated with HrpNEa and after the plant was transformed with AtPP2-A1. Results The electrical penetration graph technique was used to visualize the phloem-feeding activities of apterous agamic M. persicae females on leaves of Arabidopsis plants treated with HrpNEa and an inactive protein control, respectively. A repression of phloem feeding was induced by HrpNEa in wild-type (WT Arabidopsis but not in atpp2-a1/E/142, the plant mutant that had a defect in the AtPP2-A1 gene, the most HrpNEa-responsive of 30 AtPP2 genes. In WT rather than atpp2-a1/E/142, the deterrent effect of HrpNEa treatment on the phloem-feeding activity accompanied an enhancement of AtPP2-A1 expression. In PP2OETAt (AtPP2-A1-overexpression transgenic Arabidopsis thaliana plants, abundant amounts of the AtPP2-A1 gene transcript were detected in different organs, including leaves, stems, calyces, and petals. All these organs had a deterrent effect on the phloem-feeding activity compared with the same organs of the transgenic control plant. When a large-scale aphid population was monitored for 24 hours, there was a significant decrease in the number of aphids that colonized leaves of HrpNEa-treated WT and PP2OETAt plants, respectively, compared with control plants. Conclusions The repression in phloem-feeding activities of

  11. Bacterial hydrodynamics

    CERN Document Server

    Lauga, Eric

    2015-01-01

    Bacteria predate plants and animals by billions of years. Today, they are the world's smallest cells yet they represent the bulk of the world's biomass, and the main reservoir of nutrients for higher organisms. Most bacteria can move on their own, and the majority of motile bacteria are able to swim in viscous fluids using slender helical appendages called flagella. Low-Reynolds-number hydrodynamics is at the heart of the ability of flagella to generate propulsion at the micron scale. In fact, fluid dynamic forces impact many aspects of bacteriology, ranging from the ability of cells to reorient and search their surroundings to their interactions within mechanically and chemically-complex environments. Using hydrodynamics as an organizing framework, we review the biomechanics of bacterial motility and look ahead to future challenges.

  12. BACTERIOLOGICAL QUALITY OF COMMERCIALLY PREPARED AND SELF COMPOUNDED POULTRY FEEDS IN SOKOTO METROPOLIS, SOKOTO, NIGERIA

    OpenAIRE

    Aliyu, R. M; Egwu, E. O; M B Abubakar; Adamu, A. Y; M D Salihu; Dabai, A. I.; F.M. Tambuwal

    2013-01-01

    Evidences arising from epidemiological studies as well as from detailed experimental investigations have indicated that there is strong relationship between certain feed ingredients and incidence of bacterial infections. A total of two hundred and thirty nine (239) Poultry feed samples comprising of two hundred and four (204) commercially prepared feed and thirty five (35) self compounded feed were collected from seventy six (76) identified poultry farms in Sokoto metropolis over a period of ...

  13. Specific antibiotics and nematode trophic groups agree in assessing fungal:bacterial activity in agricultural soil

    DEFF Research Database (Denmark)

    Christensen, S; Dam, M; Vestergaard, M;

    2012-01-01

    -induced respiration (SIR) inhibition approach. Here we compare fungal contribution to the microbial active biomass assessed by the SIR inhibition method with the contribution of fungal-feeding nematodes to the microbial-feeding nematode community. Four cultivation systems on the same soil that differ in carbon inputs...... with a factor two ranked exactly the same with the two methods. A conventionally farmed rotation with low organic input had the lowest fungal fraction, while three organically farmed soils ranked higher.......There are no methods at hand with a long and proven record for assessing the relative contribution of fungi and bacteria to decomposer activity in soil. Whereas a multitude of methods to determine fungal and bacterial biomass are available, activity assays traditionally relied on the substrate...

  14. Biotechnological applications of bacterial cellulases

    Directory of Open Access Journals (Sweden)

    Esther Menendez

    2015-08-01

    Full Text Available Cellulases have numerous applications in several industries, including biofuel production, food and feed industry, brewing, pulp and paper, textile, laundry, and agriculture.Cellulose-degrading bacteria are widely spread in nature, being isolated from quite different environments. Cellulose degradation is the result of a synergic process between an endoglucanase, an exoglucanase and a,β-glucosidase. Bacterial endoglucanases degrade ß-1,4-glucan linkages of cellulose amorphous zones, meanwhile exoglucanases cleave the remaining oligosaccharide chains, originating cellobiose, which is hydrolyzed by ß-glucanases. Bacterial cellulases (EC 3.2.1.4 are comprised in fourteen Glycosil Hydrolase families. Several advantages, such as higher growth rates and genetic versatility, emphasize the suitability and advantages of bacterial cellulases over other sources for this group of enzymes. This review summarizes the main known cellulolytic bacteria and the best strategies to optimize their cellulase production, focusing on endoglucanases, as well as it reviews the main biotechnological applications of bacterial cellulases in several industries, medicine and agriculture.

  15. Effect of 4-phenyl Butyric Acid on Hepatic Lipid Deposition and Oxidative Stress Induced by High-fructose Feed-ing in Mice%4-苯基丁酸对高果糖喂养大鼠肝脏脂质沉积及氧化应激的影响

    Institute of Scientific and Technical Information of China (English)

    任路平; 张璞; 张雪梅; 宋光耀; 陈树春

    2016-01-01

    Objective To observe the effect of 4-phenyl butyric acid [4-PBA, an endoplasmic reticulum stress ( ERS) inhibitor] on hepatic oxidative stress induced by high-fructose feeding in mice and to investigate the effect of ERS mediation and its relationship with oxidative stress. Methods A total of 46 male Wistar rats were divided into control group (n=15), high-fructose feeding group (n=15) and 4-PBA intervention group (n=16) [0. 35 g/(kgod)4-PBA intervention was initiated in 4th week of high-fructose feeding]. After 8 weeks of feeding, all rats were sacrificed, and he-patic triglyceride ( TG) contents were detected. The expression of glucose regulated protein 78 ( GRP78 ) was detected with polymerase chain reaction ( PCR) method. Activities of superoxide dismutase ( SOD) , catalase ( CAT) and gluta-thione peroxidase (GSH-Px) and malondialdehyde (MDA) contents were detected. The expression of C/EBP homolo-gous protein ( CHOP) was detected with Western blot method. Results In high-fructose feeding group, the values of TG content and GRP78 and CHOP expressions were significantly increased compared with those in control group (P<0. 01);while the above values were significantly decreased in 4-PBA intervention group compared with those in high-fructose feeding group (P<0. 01). In high-fructose feeding group, the values of SOD, GSH-Px and CAT activities were signifi-cantly decreased, while MDA content was increased more than those in the control group (P<0. 01);in 4-PBA interven-tion group, the values of SOD, GSH-Px and CAT activities were significantly higher, while MDA content was lower than those in high-fructose feeding group (P<0. 01). Conclusion Long-term high-fructose feeding can induce hepatic ERS and oxidative stress, and 4-phenyl butyric acid can improve hepatic oxidative stress induced by high-fructose feeding.%目的:观察内质网应激(ERS)抑制剂4-苯基丁酸(4-PBA)对高果糖饮食喂养大鼠肝脏氧化应激的影响,以探讨ERS在高果糖喂养

  16. Longevity in mice is promoted by probiotic-induced suppression of colonic senescence dependent on upregulation of gut bacterial polyamine production.

    Directory of Open Access Journals (Sweden)

    Mitsuharu Matsumoto

    Full Text Available BACKGROUND: Chronic low-grade inflammation is recognized as an important factor contributing to senescence and age-related diseases. In mammals, levels of polyamines (PAs decrease during the ageing process; PAs are known to decrease systemic inflammation by inhibiting inflammatory cytokine synthesis in macrophages. Reductions in intestinal luminal PAs levels have been associated with intestinal barrier dysfunction. The probiotic strain Bifidobacterium animalis subsp. lactis LKM512 is known to increase intestinal luminal PA concentrations. METHODOLOGY/PRINCIPAL FINDINGS: We supplemented the diet of 10-month-old Crj:CD-1 female mice with LKM512 for 11 months, while the controls received no supplementation. Survival rates were compared using Kaplan-Meier survival curves. LKM512-treated mice survived significantly longer than controls (P<0.001; moreover, skin ulcers and tumors were more common in the control mice. We then analyzed inflammatory and intestinal conditions by measuring several markers using HPLC, ELISA, reverse transcription-quantitative PCR, and histological slices. LKM512 mice showed altered 16S rRNA gene expression of several predominant intestinal bacterial groups. The fecal concentrations of PAs, but not of short-chain fatty acids, were significantly higher in LKM512-treated mice (P<0.05. Colonic mucosal function was also better in LKM512 mice, with increased mucus secretion and better maintenance of tight junctions. Changes in gene expression levels were evaluated using the NimbleGen mouse DNA microarray. LKM512 administration also downregulated the expression of ageing-associated and inflammation-associated genes and gene expression levels in 21-month-old LKM512-treated mice resembled those in 10-month-old untreated (younger mice. CONCLUSION/SIGNIFICANCE: Our study demonstrated increased longevity in mice following probiotic treatment with LKM512, possibly due to the suppression of chronic low-grade inflammation in the colon

  17. Bacterial and fungal taxon changes in soil microbial community composition induced by short-term biochar amendment in red oxidized loam soil.

    Science.gov (United States)

    Hu, Liao; Cao, Lixiang; Zhang, Renduo

    2014-03-01

    To take full advantage of biochar as a soil amendment, the objective of this study was to investigate the effects of biochar addition on soil bacterial and fungal diversity and community composition. Incubation experiments with a forest soil (a red oxidized loam soil) with and without biochar amendment were conducted for 96 days. The culture-independent molecular method was utilized to analyze soil bacterial and fungal species after the incubation experiments. Results showed that bacteria and fungi responded differently to the biochar addition during the short-term soil incubation. Twenty four and 18 bacterial genara were observed in the biochar amended and unamended soils, respectively, whereas 11 and 8 fungal genera were observed in the biochar amended and unamended soils, respectively. Microbial taxa analysis indicated that the biochar amendment resulted in significant shifts in both bacterial and fungal taxa during the incubation period. The shift for bacteria occurred at the genus and phylum levels, while for fungi only at the genus level. Specific taxa, such as Actinobacteria of bacteria and Trichoderma and Paecilomyces of fungi, were enriched in the biochar amended soil. The results reveal a pronounced impact of biochar on soil microbial community composition and an enrichment of key bacterial and fungal taxa in the soil during the short time period. PMID:24136343

  18. Dengue virus infection of the Aedes aegypti salivary gland and chemosensory apparatus induces genes that modulate infection and blood-feeding behavior.

    Directory of Open Access Journals (Sweden)

    Shuzhen Sim

    Full Text Available The female Aedes aegypti salivary gland plays a pivotal role in bloodmeal acquisition and reproduction, and thereby dengue virus (DENV transmission. It produces numerous immune factors, as well as immune-modulatory, vasodilatory, and anti-coagulant molecules that facilitate blood-feeding. To assess the impact of DENV infection on salivary gland physiology and function, we performed a comparative genome-wide microarray analysis of the naïve and DENV infection-responsive A. aegypti salivary gland transcriptomes. DENV infection resulted in the regulation of 147 transcripts that represented a variety of functional classes, including several that are essential for virus transmission, such as immunity, blood-feeding, and host-seeking. RNAi-mediated gene silencing of three DENV infection-responsive genes--a cathepsin B, a putative cystatin, and a hypothetical ankyrin repeat-containing protein--significantly modulated DENV replication in the salivary gland. Furthermore, silencing of two DENV infection-responsive odorant-binding protein genes (OBPs resulted in an overall compromise in blood acquisition from a single host by increasing the time for initiation of probing and the probing time before a successful bloodmeal. We also show that DENV established an extensive infection in the mosquito's main olfactory organs, the antennae, which resulted in changes of the transcript abundance of key host-seeking genes. DENV infection, however, did not significantly impact probing initiation or probing times in our laboratory infection system. Here we show for the first time that the mosquito salivary gland mounts responses to suppress DENV which, in turn, modulates the expression of chemosensory-related genes that regulate feeding behavior. These reciprocal interactions may have the potential to affect DENV transmission between humans.

  19. Feed safety in the feed supply chain

    Directory of Open Access Journals (Sweden)

    Pinotti, L.

    2011-01-01

    Full Text Available A number of issues have weakened the public's confidence in the quality and wholesomeness of foods of animal origin. As a result farmers, nutritionists, industry and governments have been forced to pay serious attention to animal feedstuff production processes, thereby acknowledging that animal feed safety is an essential prerequisite for human food safety. Concerns about these issues have produced a number of important effects including the ban on the use of processed animal proteins, the ban on the addition of most antimicrobials to farm animals diets for growth‐promotion purposes, and the implementation of feed contaminant regulations in the EU. In this context it is essential to integrate knowledge on feed safety and feed supply. Consequently, purchase of new and more economic sources of energy and protein in animal diets, which is expected to conform to adequate quality, traceability, environmental sustainability and safety standards, is an emerging issue in livestock production system.

  20. Cecum microbial communities from steers differing in feed efficiency.

    Science.gov (United States)

    Myer, P R; Wells, J E; Smith, T P L; Kuehn, L A; Freetly, H C

    2015-11-01

    Apart from the rumen, limited knowledge exists regarding the structure and function of bacterial communities within the gastrointestinal tract and their association with beef cattle feed efficiency. The objective of this study was to characterize the microbial communities of the cecum among steers differing in feed efficiency. Within 2 contemporary groups of steers, individual feed intake and BW gain were determined from animals fed the same diet. Within both of 2 contemporary groups, BW was regressed on feed intake and 4 steers within each Cartesian quadrant were sampled ( = 16/group). Bacterial 16S rRNA gene amplicons were sequenced from the cecal content using next-generation sequencing technology. No significant changes in diversity or richness were detected among quadrants, and UniFrac principal coordinate analysis did not show any differences among quadrants for microbial communities within the cecum. The relative abundances of microbial populations and operational taxonomic units revealed significant differences among feed efficiency groups ( Ruminococcaceae, Lachnospiraceae, and Clostridiaceae, with significant shifts in the relative abundance of taxa among feed efficiency groups, including families Ruminococcaceae ( = 0.040), Lachnospiraceae ( = 0.020), Erysipelotrichaceae ( = 0.046), and Clostridiaceae ( = 0.043) and genera ( = 0.049), ( = 0.044), ( = 0.042), ( = 0.040), ( = 0.042), and ( = 0.042). The study identified cecal microbial associations with feed efficiency, ADG, and ADFI. This study suggests an association of the cecum microbial community with bovine feed efficiency at the 16S level. PMID:26641052

  1. Bacterial Succession in the Broiler Gastrointestinal Tract.

    Science.gov (United States)

    Ranjitkar, Samir; Lawley, Blair; Tannock, Gerald; Engberg, Ricarda M

    2016-04-15

    A feeding trial was performed with broilers receiving a diet of wheat-based feed (WBF), maize-based feed (MBF), or maize-based concentrates supplemented with 15% or 30% crimped kernel maize silage (CKMS-15 or CKMS-30, respectively). The aim of the study was to investigate the bacterial community compositions of the crop, gizzard, ileum, and cecum contents in relation to the feeding strategy and age (8, 15, 22, 25, 29, or 36 days). Among the four dietary treatments, bacterial diversity was analyzed for MBF and CKMS-30 by 454 pyrosequencing of the 16S rRNA gene. Since the diets had no significant influence on bacterial diversity, data were pooled for downstream analysis. With increasing age, a clear succession of bacterial communities and increased bacterial diversity were observed.Lactobacillaceae(belonging mainly to the genusLactobacillus) represented most of theFirmicutesat all ages and in all segments of the gut except the cecum. The development of a "mature" microbiota in broilers occurred during the period from days 15 to 22. Striking increases in the relative abundances ofLactobacillus salivarius(17 to 36%) and clostridia (11 to 18%), and a concomitant decrease in the relative abundance ofLactobacillus reuteri, were found in the ileum after day 15. The concentration of deconjugated bile salts increased in association with the increased populations ofL. salivariusand clostridia. BothL. salivariusand clostridia deconjugate bile acids, and increases in the abundances of these bacteria might be associated with growth reduction and gastrointestinal (GI) disorders occurring in the critical period of broiler life between days 20 and 30. PMID:26873323

  2. Fluoroquinolone-induced gene transfer in multidrug-resistant Salmonella

    Science.gov (United States)

    Fluoroquinolones are broad spectrum antibiotics that inhibit bacterial DNA gyrase and topoisomerase activity. Bacterial exposure to fluoroquinolones can cause DNA damage and induce a bacterial SOS response to stimulate repair of damaged DNA. Certain prophages (integrated in bacterial chromosomes) ...

  3. Bacterial fucose-rich polysaccharide stabilizes MAPK-mediated Nrf2/Keap1 signaling by directly scavenging reactive oxygen species during hydrogen peroxide-induced apoptosis of human lung fibroblast cells.

    Directory of Open Access Journals (Sweden)

    Sougata Roy Chowdhury

    Full Text Available Continuous free radical assault upsets cellular homeostasis and dysregulates associated signaling pathways to promote stress-induced cell death. In spite of the continuous development and implementation of effective therapeutic strategies, limitations in treatments for stress-induced toxicities remain. The purpose of the present study was to determine the potential therapeutic efficacy of bacterial fucose polysaccharides against hydrogen peroxide (H2O2-induced stress in human lung fibroblast (WI38 cells and to understand the associated molecular mechanisms. In two different fermentation processes, Bacillus megaterium RB-05 biosynthesized two non-identical fucose polysaccharides; of these, the polysaccharide having a high-fucose content (∼ 42% conferred the maximum free radical scavenging efficiency in vitro. Structural characterizations of the purified polysaccharides were performed using HPLC, GC-MS, and (1H/(13C/2D-COSY NMR. H2O2 (300 µM insult to WI38 cells showed anti-proliferative effects by inducing intracellular reactive oxygen species (ROS and by disrupting mitochondrial membrane permeability, followed by apoptosis. The polysaccharide (250 µg/mL attenuated the cell death process by directly scavenging intracellular ROS rather than activating endogenous antioxidant enzymes. This process encompasses inhibition of caspase-9/3/7, a decrease in the ratio of Bax/Bcl2, relocalization of translocated Bax and cytochrome c, upregulation of anti-apoptotic members of the Bcl2 family and a decrease in the phosphorylation of MAPKs (mitogen activated protein kinases. Furthermore, cellular homeostasis was re-established via stabilization of MAPK-mediated Nrf2/Keap1 signaling and transcription of downstream cytoprotective genes. This molecular study uniquely introduces a fucose-rich bacterial polysaccharide as a potential inhibitor of H2O2-induced stress and toxicities.

  4. Short-term feed deprivation alters immune status of surface mucosa in channel catfish (Ictalurus punctatus)

    Science.gov (United States)

    Short-term feed deprivation (or fasting) is a common occurrence in aquacultured fish species whether due to season, production strategies, or disease. In channel catfish (Ictalurus punctatus) fasting impacts susceptibility to several bacterial pathogens including Flavobacterium columnare, the causat...

  5. Thioautotrophic bacterial endosymbionts are degraded by enzymatic digestion during starvation: Case study of two lucinids Codakia orbicularis and C. orbiculata.

    Science.gov (United States)

    König, Sten; Le Guyader, Hervé; Gros, Olivier

    2015-02-01

    The Caribbean bivalves Codakia orbicularis (Linné, 1758) and C. orbiculata (Montagu, 1808) live in seagrass beds of Thalassia testudinum and harbor intracellular sulfur-oxidizing gamma-proteobacteria. These bacterial symbionts fix CO2 via the Calvin Benson cycle and provide organic compounds to the bivalve. During experimentally induced starvation, no reduced sulfur compounds and no organic particle food are available; the symbionts could be considered as the sole nutrient source of the host bivalve. A previous study has shown that the intracellular bacterial population decreased considerably during starvation and that bacterial endosymbionts were not released by the bivalves. In this study, the activity of two lysosomal marker enzymes (acid phosphatase and arylsulfatase) was detected using cytochemical experiments coupled with energy-dispersive X-ray transmission electron microscopy during sulfide and organic particle starvation. The degradation of bacterial endosymbionts began after 2 weeks of starvation in C. orbiculata and after 3 weeks in C. orbicularis. Degradation processes seem to be continuous over several months and could be responsible for the disappearance of the bacterial endosymbionts within the gills during starvation. These data suggest that the host use symbionts as a nutrient source to survive a hunger crisis. The carbon transfer from the symbionts to the host could be flexible and could consist in transfer of organic matter, "milking," under normal feeding conditions and digestion of the symbionts under starved conditions. PMID:25429862

  6. VLBI2010 Feed Comparison

    Science.gov (United States)

    Petrachenko, Bill

    2013-01-01

    VLBI2010 requires a feed that simultaneously has high efficiency over the full 2.2-14 GHz frequency range. The simultaneity requirement implies that the feed must operate at high efficiency over the full frequency range without the need to adjust its focal position to account for frequency dependent phase centre variations. Two feeds meet this specification: The Eleven Feed developed at Chalmers University. (For more information, contact Miroslav Pantaleev, miroslav.pantaleev@chalmers.se. The Eleven Feed, integrated with LNA's in a cryogenic receiver, is available as a product from Omnisys Instruments, info@omnisys.se). The Quadruple Ridged Flared Horn (QRFH) developed at the California Institute of Technology. (For more information please contact Ahmed Akgiray, aakgiray@ieee.org or Sander Weinreb, sweinreb@caltech.edu) Although not VLBI2010 compliant, two triband S/X/Ka feeds are also being developed for the commissioning of VLBI2010 antennas, for S/X observations during the VLBI2010 transition period, and to support X/Ka CRF observations. The two feeds are: The Twin Telescopes Wettzell (TTW) triband feed developed by Mirad Microwave. (For more information please contact Gerhard Kronschnabl, Gerhard.Kronschnabl@bkg.bund.de) The RAEGE (Spain) triband feed developed at Yebes Observatory. (For more information please contact Jose Antonio Lopez Perez, ja.lopezperez@oan.es)

  7. Feeding ducks, bacterial chemotaxis, and the Gini index

    CERN Document Server

    Peaudecerf, Francois J

    2015-01-01

    Classic experiments on the distribution of ducks around separated food sources found consistency with the `ideal free' distribution in which the local population is proportional to the local supply rate. Motivated by this experiment and others, we examine the analogous problem in the microbial world: the distribution of chemotactic bacteria around multiple nearby food sources. In contrast to the optimization of uptake rate that may hold at the level of a single cell in a spatially varying nutrient field, nutrient consumption by a population of chemotactic cells will modify the nutrient field, and the uptake rate will generally vary throughout the population. Through a simple model we study the distribution of resource uptake in the presence of chemotaxis, consumption, and diffusion of both bacteria and nutrients. Borrowing from the field of theoretical economics, we explore how the Gini index can be used as a means to quantify the inequalities of uptake. The redistributive effect of chemotaxis can lead to a p...

  8. Feeding ducks, bacterial chemotaxis, and the Gini index

    Science.gov (United States)

    Peaudecerf, François J.; Goldstein, Raymond E.

    2015-08-01

    Classic experiments on the distribution of ducks around separated food sources found consistency with the "ideal free" distribution in which the local population is proportional to the local supply rate. Motivated by this experiment and others, we examine the analogous problem in the microbial world: the distribution of chemotactic bacteria around multiple nearby food sources. In contrast to the optimization of uptake rate that may hold at the level of a single cell in a spatially varying nutrient field, nutrient consumption by a population of chemotactic cells will modify the nutrient field, and the uptake rate will generally vary throughout the population. Through a simple model we study the distribution of resource uptake in the presence of chemotaxis, consumption, and diffusion of both bacteria and nutrients. Borrowing from the field of theoretical economics, we explore how the Gini index can be used as a means to quantify the inequalities of uptake. The redistributive effect of chemotaxis can lead to a phenomenon we term "chemotactic levelling," and the influence of these results on population fitness are briefly considered.

  9. Bacterial translocation: the influence of dietary variables.

    OpenAIRE

    Deitch, E A

    1994-01-01

    Transmucosal passage of bacteria in critically ill patients may lead to a significant incidence of systemic sepsis. This has attracted much clinical interest, as it has been shown that malnutrition in itself, impairs various aspects of barrier function. Bacterial translocation is increased in animal models where nutrients are given by the parenteral route, while enteral feeding reverses this. Translocation is also considerably increased in response to a non-lethal endotoxin challenge, if ther...

  10. Feed up, Feedback, and Feed Forward

    Science.gov (United States)

    Fisher, Douglas; Frey, Nancy

    2011-01-01

    "Feeding up" establishes a substantive line of inquiry that compels learners to engage in investigation and inquire. It also forms the basis for the assessments that follow. Once students understand the purpose and begin to work, they receive "feedback" that is timely and scaffolds their understanding. Based on their responses, the teacher gains a…

  11. Selection of Feed Intake or Feed Efficiency

    DEFF Research Database (Denmark)

    Veerkamp, Roel F; Pryce, Jennie E; Spurlock, Diane;

    2013-01-01

    The widespread use of genomic information in dairy cattle breeding programs has opend up the possibility to select for novel traits, especially for traits that are traditionally difficult to record in a progeny testing scheme. Feed intake and efficiency is such a difficult to measure trait. In Fe...

  12. Evaluation of changes in serum chemistry in association with feed withdrawal or high dose oral gavage with Dextran Sodium Sulfate (DSS) induced gut leakage in broiler chickens

    Science.gov (United States)

    Dextran sodium sulfate (DSS) has been shown to be effective at inducing enteric inflammation in broiler chickens, resulting in increased leakage of orally administered fluorescein isothiocyanate dextran to circulation. In a previous study, two doses of DSS (0.45g/dose) administered as oral gavage re...

  13. Development of Wideband Feed

    Science.gov (United States)

    Ujihara, Hideki; Takefuji, Kazuhiro; Sekido, Mamoru; Kondo, Tetsuro

    2015-08-01

    Wideband feeds have developed for Kashima 34m antenna and new 2.4m portable VLBI antennas. Prototypes of the wideband feeds are multimode horns, first one was set on 34m in the end of 2013, and then replaced next one with 6.5-15.0GHz receiving frequency. Now, a new feed for 3.2GHz-14.4GHz will be installed in 2.4m and 34m antennas in this spring, which are named NINJA feed, because of its design flexibility in beam shpae. Next, IGUANA feed is now under design and fabrication, which is aimed for 2.2-22GHz and covers VGOS(VLBI2010) specification. This has coaxial structure, the smaller "daughter feed" for 6.4-22GHz is placed in the center of the larger "Mother feed" for 2.2-6.4GHz.They are used for our project of time and frequency transfer between remote atomic clocks by wideband VLBI, named Gala-V(Garapagos VLBI), and will also be used wideband VLBI observation for astronmy and geodesy.Prototype feeds were tested in measurement of aperture efficiency, SEFD and Tsys of 34m "Super Kashima Antenna" and both 6.7/12.2GHz methanol maser detection in one reciever system, and then better one is used for wideband VLBI observations.

  14. Induction and Function of IFNβ During Viral and Bacterial Infection

    OpenAIRE

    Nagarajan, Uma M.

    2011-01-01

    Since the discovery of the protein “interferon” over 50 years ago, IFNβ, an antiviral cytokine has been well studied. In particular the pathways inducing this cytokine during viral infection have been characterized, leading to the discovery of multitude of pattern recognition receptors. IFNβ is also induced during bacterial infection, following recognition of bacterial ligands by the host viral and DNA sensors. However, the function of IFNβ during bacterial infection is variable and -sometime...

  15. Dynamics of bacterial gene regulation

    Science.gov (United States)

    Narang, Atul

    2009-03-01

    The phenomenon of diauxic growth is a classical problem of bacterial gene regulation. The most well studied example of this phenomenon is the glucose-lactose diauxie, which occurs because the expression of the lac operon is strongly repressed in the presence of glucose. This repression is often explained by appealing to molecular mechanisms such as cAMP activation and inducer exclusion. I will begin by analyzing data showing that these molecular mechanisms cannot explain the strong lac repression because they exert a relatively weak effect. I will then present a minimal model accounting only for enzyme induction and dilution, which yields strong repression despite the absence of catabolite repression and inducer exclusion. The model also explains the growth patterns observed in batch and continuous cultures of various bacterial strains and substrate mixtures. The talk will conclude with a discussion of the experimental evidence regarding positive feedback, the key component of the minimal model.

  16. Methods for baiting and enriching fungus-feeding (Mycophagous) rhizosphere bacteria

    NARCIS (Netherlands)

    Ballhausen, Max Bernhard; Veen, Van J.A.; Hundscheid, M.P.J.; Boer, De Wietse

    2015-01-01

    Mycophagous soil bacteria are able to obtain nutrients from living fungal hyphae. However, with exception of the soil bacterial genus Collimonas, occurrence of this feeding strategy has not been well examined. Evaluation of the importance of mycophagy in soil bacterial communities requires target

  17. Induction of bacterial blight resistance in elite Indian rice cultivars using gamma-rays and ethyl methanesulfonate

    International Nuclear Information System (INIS)

    Rice is the most important cereal crop in the world feeding more than 50 percent of the human population. During the last 30 years, induced mutation breeding has played a significant role in rice breeding programmes. Rice mutants with higher yield, greater tolerance to diseases and pests and other agronomic qualities have been released for commercial cultivation in many countries. Bacterial blight (BB) caused by Xanthomonas oryzae pv. oryzae is the second important disease in Southeast Asia. In the Basmati field sometime the yield loss is up to 100%. Moreover, there is no resistance source available. In Basmati rice, which is known for its quality and aroma. Induction of bacterial blight resistance in Basmati will help in developing high yielding Basmati type cultivars without compromising the quality

  18. Study of case of bacterial corrosion in nuclear industries

    International Nuclear Information System (INIS)

    A lot of problems happened in nuclear industry in the United States are due to bacterial corrosion. The concerned equipments are: servitude systems or raw water transport, heat exchangers, anti-fire circuits, condensers. The concerned materials are various: stainless steels ''AISI 304 or 316'', carbon steels, cupronickel alloys. They occur generally on welded joints and happen when the material is submitted to long periods of maintaining in stagnant or quasi-stagnant water. The second part of the work deals with bacterial corrosion cases happened in France in the auxiliary systems of a nuclear power plant as well as the studies which have been carried out at this effect. The different expert opinions lead to consider the hypothesis of an accelerated corrosion due to bacteria presence. In order to assess the validity of this hypothesis, a corrosion loop has been carried out to compare the behaviour of two identical systems in stainless steel Z2 CN 18-10, the first one feeds with Moselle water and the other one with this water made sterile. After a year of study, a more important corrosion, by pitting or crevice, appears in the system containing the raw Moselle water. It affects exclusively the welded joints. The pitting morphology obtained only in the unsterile medium and their widespread seems to be due to a bacterial influence. The electrochemical measures have on the other hand display a behaviour difference between the sterile and unsterile medium. The disastrous play of bacteria do not seem to imply directly the sulfato-reducing bacteria action, and the mechanism is to be precised. This study shows then that the presence of bacteria can induce or accelerate the pitting corrosion and is not simply an independent associated phenomenon. (O.M.)

  19. Gastrostomy feeding tube - pump - child

    Science.gov (United States)

    Feeding - gastrostomy tube - pump; G-tube - pump; Gastrostomy button - pump; Bard Button - pump; MIC-KEY - pump ... Gather supplies: Feeding pump (electronic or battery powered) Feeding set that matches the feeding pump (includes a feeding bag, drip chamber, roller clamp, ...

  20. Cordyceps sinensis biomass produced by submerged fermentation in high-fat diet feed rats normalizes the blood lipid and the low testosterone induced by diet

    OpenAIRE

    Aikawa, Júlia; Bonatto, Sandro José Ribeiro; Freire dos Santos, Leandro; Habu, Sascha; Prado, Karin Braun.; Rubel, Rosália; Soccol, Carlos Ricardo; Soccol, Vanete Thomaz; De Torres, Maria Fernanda; Yamaguchi, Adriana Aya; Zanatta, Ana Lucia

    2013-01-01

    This study investigated the effect of Cordyceps sinensis biomass supplementation obtained from submerged fermentation on blood lipid and low testosterone induced by high-fat diet (HFD). The experiments were carried out using a long-term intake of HFD and HFD plus Simvastatin or C. sinensis (4 months). Our results show that plasma cholesterol, triglycerides and LDL were decreased by Cordyceps sinensis biomass supplementation (CSBS). A longterm intake of HFD caused a significant liver damage wh...

  1. The bacterial communities of Drosophila suzukii collected from undamaged cherries

    OpenAIRE

    James Angus Chandler; James, Pamela M.; Guillaume Jospin; Lang, Jenna M.

    2014-01-01

    Drosophila suzukii is an introduced pest insect that feeds on undamaged, attached fruit. This diet is distinct from the fallen, discomposing fruits utilized by most other species of Drosophila. Since the bacterial microbiota of Drosophila, and of many other animals, is affected by diet, we hypothesized that the bacteria associated with D. suzukii are distinct from that of other Drosophila. Using 16S rDNA PCR and Illumina sequencing, we characterized the bacterial communities of larval and adu...

  2. A novel functional T cell hybridoma recognizes macrophage cell death induced by bacteria: a possible role for innate lymphocytes in bacterial infection.

    Science.gov (United States)

    Kubota, Koichi

    2006-06-15

    We have established a novel TCRalphabeta (TCRVbeta6)(+)CD4(-)CD8(-) T cell hybridoma designated B6HO3. When the B6HO3 cells were cocultured with bacterial-infected J774 macrophage-like cells, IFN-gamma production by B6HO3 cells was triggered through direct cell-cell contact with dying J774 cells infected with Listeria monocytogenes (LM), Shigella flexneri, or Salmonella typhimurium that expressed the type III secretion system, but not with intact J774 cells infected with heat-killed LM, nonhemolytic lysteriolysin O-deficient (Hly(-)) LM, plasmid-cured Shigella, or stationary-phase Salmonella. However, the triggering of B6HO3 cells for IFN-gamma production involved neither dying hepatoma cells infected with LM nor dying J774 cells caused by gliotoxin treatment or freeze thawing. Cycloheximide and Abs to H-2K(d), H-2D(d), Ia(d), CD1d, TCRVbeta6, and IL-12 did not inhibit the contact-dependent IFN-gamma response, indicating that this IFN-gamma response did not require de novo protein synthesis in bacterial-infected J774 cells and was TCR and IL-12 independent. Thus, in an as yet undefined way, B6HO3 hybridoma recognizes a specialized form of macrophage cell death resulting from bacterial infection and consequently produces IFN-gamma. Moreover, contact-dependent interaction of minor subsets of splenic alphabeta T cells, including NKT cells with dying LM-infected J774 and bone marrow-derived macrophage (BMM) cells, proved to provide an IFN-gamma-productive stimulus for these minor T cell populations, to which the parental T cell of the B6HO3 hybridoma appeared to belong. Unexpectedly, subsets of gammadelta T and NK cells similarly responded to dying LM-infected macrophage cells. These results propose that innate lymphocytes may possess a recognition system sensing macrophage cell "danger" resulting from bacterial infection. PMID:16751404

  3. Bacterial Nail Infection (Paronychia)

    Science.gov (United States)

    ... of nail infection is often caused by a bacterial infection but may also be caused by herpes, a ... to a type of yeast called Candida , or bacterial infection, and this may lead to abnormal nail growth. ...

  4. Bacterial Feeders, the Nematode Caenorhabditis elegans and the Flagellate Cercomonas longicauda, have different Effects on Outcome of Competition among the Pseudomonas Biocontrol Strains CHA0 and DSS73

    DEFF Research Database (Denmark)

    Pedersen, Annette; Nybroe, Ole; Winding, Anne; Ekelund, Flemming; Strandmark, Lisa Bjørnlund

    2009-01-01

    How bacterial feeding fauna affects colonization and survival of bacteria in soil is not well understood, which constrains the applicability of bacterial inoculants in agriculture. This study aimed to unravel how food quality of bacteria and bacterial feeders with different feeding habits (the......50090 or one of two biocontrol strains P. fluorescens CHA0 or Pseudomonas sp. DSS73) or combinations of two bacterial strains. DSM50090 is a suitable food bacterium, DSS73 is of intermediate food quality, and CHA0 is inedible to the bacterial feeders. Bacterial and protozoan cell numbers were measured...

  5. Metamorphosis of a butterfly-associated bacterial community.

    Directory of Open Access Journals (Sweden)

    Tobin J Hammer

    Full Text Available Butterflies are charismatic insects that have long been a focus of biological research. They are also habitats for microorganisms, yet these microbial symbionts are little-studied, despite their likely importance to butterfly ecology and evolution. In particular, the diversity and composition of the microbial communities inhabiting adult butterflies remain uncharacterized, and it is unknown how the larval (caterpillar and adult microbiota compare. To address these knowledge gaps, we used Illumina sequencing of 16S rRNA genes from internal bacterial communities associated with multiple life stages of the neotropical butterfly Heliconius erato. We found that the leaf-chewing larvae and nectar- and pollen-feeding adults of H. erato contain markedly distinct bacterial communities, a pattern presumably rooted in their distinct diets. Larvae and adult butterflies host relatively small and similar numbers of bacterial phylotypes, but few are common to both stages. The larval microbiota clearly simplifies and reorganizes during metamorphosis; thus, structural changes in a butterfly's bacterial community parallel those in its own morphology. We furthermore identify specific bacterial taxa that may mediate larval and adult feeding biology in Heliconius and other butterflies. Although male and female Heliconius adults differ in reproductive physiology and degree of pollen feeding, bacterial communities associated with H. erato are not sexually dimorphic. Lastly, we show that captive and wild individuals host different microbiota, a finding that may have important implications for the relevance of experimental studies using captive butterflies.

  6. Prevention of bacterial adhesion

    DEFF Research Database (Denmark)

    Klemm, Per; Vejborg, Rebecca Munk; Hancock, Viktoria

    2010-01-01

    Management of bacterial infections is becoming increasingly difficult due to the emergence and increasing prevalence of bacterial pathogens that are resistant to available antibiotics. Conventional antibiotics generally kill bacteria by interfering with vital cellular functions, an approach that....... As such, adhesion represents the Achilles heel of crucial pathogenic functions. It follows that interference with adhesion can reduce bacterial virulence. Here, we illustrate this important topic with examples of techniques being developed that can inhibit bacterial adhesion. Some of these will...

  7. FRACTIONAL CRYSTALLIZATION FEED ENVELOPE

    International Nuclear Information System (INIS)

    Laboratory work was completed on a set of evaporation tests designed to establish a feed envelope for the fractional crystallization process. The feed envelope defines chemical concentration limits within which the process can be operated successfully. All 38 runs in the half-factorial design matrix were completed successfully, based on the qualitative definition of success. There is no feed composition likely to be derived from saltcake dissolution that would cause the fractional crystallization process to not meet acceptable performance requirements. However, some compositions clearly would provide more successful operation than other compositions

  8. DNA vaccines and bacterial DNA in immunity

    OpenAIRE

    Bandholtz, Lisa Charlotta

    2002-01-01

    This thesis describes DNA-based vaccination and the importance of bacterial DNA in different immunological perspectives. Intranasal (i.n.) DNA vaccination utilizing a plasmid encoding the chlamydial heat shock protein 60 (p-hsp-60) generated lower bacterial burden and reduced pathology in the lungs of mice after subsequent infection with C. pneumoniae. This DNA vaccine- induced protection was dependent on T cells and induction of IFN-gamma. Co-administration of a plasmid...

  9. Bacterial Probiotic Modulation of Dendritic Cells

    OpenAIRE

    Drakes, Maureen; Blanchard, Thomas; Czinn, Steven

    2004-01-01

    Intestinal dendritic cells are continually exposed to ingested microorganisms and high concentrations of endogenous bacterial flora. These cells can be activated by infectious agents and other stimuli to induce T-cell responses and to produce chemokines which recruit other cells to the local environment. Bacterial probiotics are of increasing use against intestinal disorders such as inflammatory bowel disease. They act as nonpathogenic stimuli within the gut to regain immunologic quiescence. ...

  10. Bioaccumulation of selenium and induced biological effects in the filter feeding bivalve Corbicula fluminea: influence of ventilatory activity, selenium speciation and route of transfer

    International Nuclear Information System (INIS)

    Selenium is an essential micro-nutrient for most of living organisms. However, toxic effects in several ecosystems have been reported in the literature. Toxicity comprehension is difficult due to the complexity of Se oxidation states in the environment. The aim of this thesis work was to acquire knowledge on the physiological and environmental factors involved in bioaccumulation and toxicity processes in the freshwater filter-feeding bivalve C. fluminea. The aims were: i) to define what the factors involved in Se bioaccumulation processes in the bivalve are, ii) to characterize Se bioaccumulation at different biological organisation levels, iii) to investigate Se toxic effects. First experiments, carried out for short term exposure duration (3 days), have permitted to underline the importance of Se chemical speciation in bioaccumulation processes in C. fluminea. It has been shown that the organic form, seleno-methionine, was much more bio-available than the inorganic forms, selenite and selenate. Moreover, the route of transfer was determinant in those processes. Inorganic forms have been better extracted by trophic route, whereas seleno-methionine has been better extracted by the direct route. In our experimental conditions, ventilation of the bivalve has not been a limiting factor for Se bioaccumulation by the direct route, whereas it has been for bioaccumulation by the trophic route. Ventilation has been largely modified by the presence of dissolved selenite and seleno-methionine. We have shown that the kinetics of seleno-methionine bioaccumulation are much more fast than those of selenite. Moreover, when introduced as SeMet, internalized Se appeared to be relatively remanent in soft tissues of C. fluminea in comparison with Se internalized when introduced as selenite. Subcellular and molecular distributions of these forms were very different. Finally, it has been shown that seleno-methionine and selenite could generate weak alterations of the anti

  11. Survey of quality of swine feed mixes

    Directory of Open Access Journals (Sweden)

    Mašić Zoran

    2002-01-01

    Full Text Available The paper presents the results of analyses of the chemical composition of 455 samples, microbiological analysis of 412 samples, and mucotoxicological analyses of 212 samples of feed mixes for different categories of swine which arrived for control at authorized laboratories from the territory of the Republic of Serbia during the period from 2000 until 2001. The analyses of 455 swine feed mix samples showed that as many as 185 feed mixes do not meet the quality condition on protein content envisaged by legal regulations, and the highest discrepancy was determined in feed mixes for piglets. Analyses of Ca, P and NaCl contents showed that the mixes in a large number of cases contain insufficient quantities, and in a considerable number even quantities which are not permitted. Analyses of the contents of certain microelements showed that mixes contain insufficient quantities in a large number of cases, especially of copper, manganese and zinc. The number of saprophytic bacteria greatly varied depending on the type of feed mix but all examined samples contained a permitted number of saprophytic bacteria. These analyses most often isolated Bacillus spp., Staphylococcus spp., coliform bacteries, and Micrococcus spp.. Most examined samples contained a permitted number of clostridia, and a smaller number of samples mostly for piglets, showed an impermissible number of clostridia. The quantity of mold fungi in mixes was significantly higher in mixes for young animals, and the determination of fungi most frequently resulted in the isolation of Penicillium spp., Aspergillus spp., Fusarium spp., and Mucor spp.. The mucotoxin analysis of 212 feed mixes showed that only 30.2% were within permitted levels, and the differences between the mixes for young and adult animals were not significant. The mucotoxins most often present were zearalenon and ochratoxin, and all mixes in which aflatoxin and trychotecenes were identified contained these toxins in quantities

  12. BACTERIOLOGICAL QUALITY OF COMMERCIALLY PREPARED AND SELF COMPOUNDED POULTRY FEEDS IN SOKOTO METROPOLIS, SOKOTO, NIGERIA

    Directory of Open Access Journals (Sweden)

    Aliyu, R. M

    2013-03-01

    Full Text Available Evidences arising from epidemiological studies as well as from detailed experimental investigations have indicated that there is strong relationship between certain feed ingredients and incidence of bacterial infections. A total of two hundred and thirty nine (239 Poultry feed samples comprising of two hundred and four (204 commercially prepared feed and thirty five (35 self compounded feed were collected from seventy six (76 identified poultry farms in Sokoto metropolis over a period of 12 months for assessing their microbiological (bacterial quality. Of the total 80 questionnaires administered, 76 (95.00% were responded to. Of the respondents, 53 (69.74% indicated using commercially prepared feed while 23 (30.26% compounded the feed by themselves. Similarly, 30.57% of the farms visited store their feed either within the poultry pen or in an open space. Out of total (n=239, commercially prepared (n=204 and Self compounded (n=35 feed samples, 217 (90.79% samples yielded positive bacterial growth. Based on culture and identification, 263 bacterial species/genus were identified which include the following: Corynebacterium pyogenes (9; 3.42%, Bacillus subtilis (60; 22.81%, Enterobacter arrogenes (6; 2.28%, Escherichia coli (57; 21.67%, Listeria monocytogenes (19; 7.22%, Coagulase-negative staphylococcus (8; 3.04%, Pasturella multocida (3; 1.14%, Pseudomona aerogenosa (7; 2.66%, Proteus mirabilis (1; 0.38%, Proteus vulgaris (17; 6.46%, Salmonella spp. (10; 3.80%, Staphylococcu aureus (44; 16.73%, Streptococcus pyogenes (17; 6.46%, Yersinia enterocolitica (3; 1.14% and (2; 0.76% unidentified bacterial species. The presence of the above bacteria in all the feed samples calls for attention in the storage methods employed by the poultry and other livestock farmers, the warehouse condition, distributors and the sellers. This result could be used as a baseline data in setting public health standard for poultry feeds to achieve food security concern issues.

  13. Feeding Your Teen Vegetarian

    Science.gov (United States)

    ... For Preschooler For Gradeschooler For Teen Feeding Your Teen Vegetarian By Mindy Hermann, MBA, RD Published July ... fries, soft drinks, desserts and candy. Have Your Teen Help "A vegetarian meal can be a healthy ...

  14. Transition feeding of sows

    DEFF Research Database (Denmark)

    Theil, Peter Kappel

    to shifts in housing, and in Europe, this shift is now associated with a change from loose group housing to individual housing. Around parturition, colostrum is being secreted and milk synthesis is initiated in the mammary glands. After the onset of lactation, milk composition changes, especially...... feeding practices do not acknowledge these changes. Development of new feeding strategies specifically adapted for the transition sow is likely of importance to match the rapid changes in nutrient requirements....

  15. Probiotic in Ruminant Feed

    OpenAIRE

    Dicky Pamungkas; Yenny Nur Anggraeni

    2006-01-01

    The technology development of ruminant feed is related to the effort of fulfilling the nutrient requirement for maintenance and production of rumen microbes and optimizing the protein synthesis of rumen microbes, hence improving the animal production . Probiotic is widely used in feed to avoid the negative effect of antibiotic after therapeutic treatment and to be used as growth promoter . This paper describes the concept of probiotic, selection of microbes for probiotic, the benefit, the eff...

  16. The effect of milk feeding method on calves' behavioural sleep

    OpenAIRE

    Hänninen, L.; Hepola, H.; Raussi, S.; Sariola, J.; Khalili, H; Saloniemi, H

    2006-01-01

    Our aim was to study how calves' sleep could be affected by the milk feeding and housing methods. We concluded that possibility to suck milk increased the amount of calves' behavioural quiet sleep and sleepiness after feeding, possibly due to suck-induced hormonal effects.

  17. Group A rotavirus and bacterial agents associated with diarrhoea-induced hospitalisations in children below 5 years of age in Jammu

    Directory of Open Access Journals (Sweden)

    S Gazal

    2014-01-01

    Full Text Available Out of 210 faecal samples collected from children below 5 years attending different hospitals in Jammu and exhibiting clinical signs of diarrhoea, 41.9% samples were found positive for group A rotavirus by RNA-PAGE. Escherichia coli isolated in the study belonged to nine serogroups, out of which O69 was most frequent, being present in 12.38% samples. E. coli serogroups well recognised as enteropathogens viz. O69, O20 and O153 were present in 27.6% samples. Other bacterial pathogens associated with diarrhoea were present in 8.09% samples, out of which Shigella spp. was found in 4.76% samples followed by Salmonella spp. (2.38% and Pseudomonas spp. (0.95%.

  18. 31 CFR 540.317 - Uranium feed; natural uranium feed.

    Science.gov (United States)

    2010-07-01

    ... 31 Money and Finance: Treasury 3 2010-07-01 2010-07-01 false Uranium feed; natural uranium feed... (Continued) OFFICE OF FOREIGN ASSETS CONTROL, DEPARTMENT OF THE TREASURY HIGHLY ENRICHED URANIUM (HEU) AGREEMENT ASSETS CONTROL REGULATIONS General Definitions § 540.317 Uranium feed; natural uranium feed....

  19. Transition from parenteral to enteral nutrition induces immediate diet-dependent gut histological and immunological responses in preterm neonates

    DEFF Research Database (Denmark)

    Siggers, Jayda; Sangild, Per T.; Jensen, Tim Kåre;

    2011-01-01

    -six preterm pigs were fed total parenteral nutrition (TPN) for 48 h followed by enteral feeding for 0, 8, 17, or 34 h with either colostrum (Colos, n = 20) or formula (Form, n = 31). Macroscopic NEC lesions were detected in Form pigs throughout the enteral feeding period (20/31, 65%), whereas most Colos pigs...... bacterial groups (Clostridium, Enterococcus, Streptococcus species) increased with time. We conclude that a switch from parenteral to enteral nutrition rapidly induces diet-dependent histopathological, functional, and proinflammatory insults to the immature intestine. Great care is required when introducing...

  20. Effects of High Fat Feeding and Diabetes on Regression of Atherosclerosis Induced by Low-Density Lipoprotein Receptor Gene Therapy in LDL Receptor-Deficient Mice

    Science.gov (United States)

    Willecke, Florian; Yuan, Chujun; Oka, Kazuhiro; Chan, Lawrence; Hu, Yunying; Barnhart, Shelley; Bornfeldt, Karin E.; Goldberg, Ira J.; Fisher, Edward A.

    2015-01-01

    We tested whether a high fat diet (HFD) containing the inflammatory dietary fatty acid palmitate or insulin deficient diabetes altered the remodeling of atherosclerotic plaques in LDL receptor knockout (Ldlr-/-) mice. Cholesterol reduction was achieved by using a helper-dependent adenovirus (HDAd) carrying the gene for the low-density lipoprotein receptor (Ldlr; HDAd-LDLR). After injection of the HDAd-LDLR, mice consuming either HFD, which led to insulin resistance but not hyperglycemia, or low fat diet (LFD), showed regression compared to baseline. However there was no difference between the two groups in terms of atherosclerotic lesion size, or CD68+ cell and lipid content. Because of the lack of effects of these two diets, we then tested whether viral-mediated cholesterol reduction would lead to defective regression in mice with greater hyperglycemia. In both normoglycemic and streptozotocin (STZ)-treated hyperglycemic mice, HDAd-LDLR significantly reduced plasma cholesterol levels, decreased atherosclerotic lesion size, reduced macrophage area and lipid content, and increased collagen content of plaque in the aortic sinus. However, reductions in anti-inflammatory and ER stress-related genes were less pronounced in STZ-diabetic mice compared to non-diabetic mice. In conclusion, HDAd-mediated Ldlr gene therapy is an effective and simple method to induce atherosclerosis regression in Ldlr-/- mice in different metabolic states. PMID:26046657

  1. Effects of High Fat Feeding and Diabetes on Regression of Atherosclerosis Induced by Low-Density Lipoprotein Receptor Gene Therapy in LDL Receptor-Deficient Mice.

    Directory of Open Access Journals (Sweden)

    Florian Willecke

    Full Text Available We tested whether a high fat diet (HFD containing the inflammatory dietary fatty acid palmitate or insulin deficient diabetes altered the remodeling of atherosclerotic plaques in LDL receptor knockout (Ldlr-/- mice. Cholesterol reduction was achieved by using a helper-dependent adenovirus (HDAd carrying the gene for the low-density lipoprotein receptor (Ldlr; HDAd-LDLR. After injection of the HDAd-LDLR, mice consuming either HFD, which led to insulin resistance but not hyperglycemia, or low fat diet (LFD, showed regression compared to baseline. However there was no difference between the two groups in terms of atherosclerotic lesion size, or CD68+ cell and lipid content. Because of the lack of effects of these two diets, we then tested whether viral-mediated cholesterol reduction would lead to defective regression in mice with greater hyperglycemia. In both normoglycemic and streptozotocin (STZ-treated hyperglycemic mice, HDAd-LDLR significantly reduced plasma cholesterol levels, decreased atherosclerotic lesion size, reduced macrophage area and lipid content, and increased collagen content of plaque in the aortic sinus. However, reductions in anti-inflammatory and ER stress-related genes were less pronounced in STZ-diabetic mice compared to non-diabetic mice. In conclusion, HDAd-mediated Ldlr gene therapy is an effective and simple method to induce atherosclerosis regression in Ldlr-/- mice in different metabolic states.

  2. Age-related and light-induced plasticity in opsin gene expression and in primary and secondary visual centers of the nectar-feeding ant Camponotus rufipes.

    Science.gov (United States)

    Yilmaz, Ayse; Lindenberg, Annekathrin; Albert, Stefan; Grübel, Kornelia; Spaethe, Johannes; Rössler, Wolfgang; Groh, Claudia

    2016-09-01

    Camponotus rufipes workers are characterized by an age-related polyethism. In the initial weeks of adult life, young workers perform tasks inside the nest before they switch to multimodal foraging tasks outside. We tested the hypothesis that this transition is accompanied by profound adaptations in the peripheral and central visual systems. Our results show that C. rufipes workers of all tested ages (between 1 and 42 days) express three genes encoding for ultraviolet (UV), blue (BL), and long-wavelength (LW1) sensitive opsins in their retina, which are likely to provide the substrate for trichromatic color vision. Expression levels of all three opsin genes increased significantly within the first two weeks of adulthood and following light exposure. Interestingly, the volumes of all three optic neuropils (lamina, medulla, and lobula) showed corresponding volume increases. Tracing of connections to higher visual centers in the mushroom bodies (MBs) revealed only one optic pathway, the anterior superior optic tract, emerging from the medulla and sending segregated input to the MB-calyx collar. The MB collar volumes and densities of synaptic complexes (microglomeruli, MGs) increased with age. Exposure to light for 4 days induced a decrease in MG densities followed by an increase after extended light exposure. This shows that plasticity in retinal opsin gene expression and structural neuroplasticity in primary and secondary visual centers comprise both "experience-independent" and "experience-dependent" elements. We conclude that both sources of plasticity in the visual system represent important components promoting optimal timing of the interior-forager transition and flexibility of age-related division of labor. © 2016 Wiley Periodicals, Inc. Develop Neurobiol 76: 1041-1057, 2016. PMID:26724470

  3. Antimutagenic effect of essential oil of sage (Salvia officinalis L. and its fractions against UV-induced mutations in bacterial and yeast cells

    Directory of Open Access Journals (Sweden)

    Knežević-Vukčević Jelena B.

    2005-01-01

    Full Text Available The inhibition of spontaneous and UV-induced mutations by essential oil (EO of sage (Salvia officinalis L. and its fractions F1-F5 containing different proportions of mono- and sesquiterpenes was studied with the Salmonella/microsome, E. coli K12, and S. cerevisiae D7 reversion assays. The EO, F1, and F2 exhibited antimutagenic potential against UV-induced mutations in all tests. Fractions F3 and F4 produced a toxic, mutagenic, or antimutagenic response, depend­ing on the test organism used. Reduction of spontaneous and UV-induced mutations by F5 was detected only in permeable strains of E. coli. The obtained results demonstrate antimutagenic activity of volatile sage terpenes and recommend them for further antimutagenesis and anticarcinogenesis studies.

  4. The Agricultural Antibiotic Carbadox Induces Phage-mediated Gene Transfer in Salmonella

    Directory of Open Access Journals (Sweden)

    Bradley L. Bearson

    2014-02-01

    Full Text Available Antibiotics are used for disease therapeutic or preventative effects in humans and animals, as well as for enhanced feed conversion efficiency in livestock. Antibiotics can also cause undesirable effects in microbial populations, including selection for antibiotic resistance, enhanced pathogen invasion, and stimulation of horizontal gene transfer. Carbadox is a veterinary antibiotic used in the U.S. during the starter phase of swine production for improved feed efficiency and control of swine dysentery and bacterial swine enteritis. Carbadox has been shown in vitro to induce phage-encoded Shiga toxin in Shiga toxin-producing Escherichia coli and a phage-like element transferring antibiotic resistance genes in Brachyspira hyodysenteriae, but the effect of carbadox on prophages in other bacteria is unknown. This study examined carbadox exposure on prophage induction and genetic transfer in Salmonella enterica serovar Typhimurium, a human foodborne pathogen that frequently colonizes swine without causing disease. S. Typhimurium LT2 exposed to carbadox induced prophage production, resulting in bacterial cell lysis and release of virions that were visible by electron microscopy. Carbadox induction of phage-mediated gene transfer was confirmed by monitoring the transduction of a sodCIII::neo cassette in the Fels-1 prophage from LT2 to a recipient Salmonella strain. Furthermore, carbadox frequently induced generalized transducing phages in multidrug-resistant phage type DT104 and DT120 isolates, resulting in the transfer of chromosomal and plasmid DNA that included antibiotic resistance genes. Our research indicates that exposure of Salmonella to carbadox induces prophages that can transfer virulence and antibiotic resistance genes to susceptible bacterial hosts. Carbadox-induced, phage-mediated gene transfer could serve as a contributing factor in bacterial evolution during animal production, with prophages being a reservoir for bacterial fitness

  5. Vaccination with Brucella abortus Recombinant In Vivo-Induced Antigens Reduces Bacterial Load and Promotes Clearance in a Mouse Model for Infection

    OpenAIRE

    Jake E Lowry; Isaak, Dale D.; Leonhardt, Jack A.; Giulia Vernati; Jessie C Pate; Andrews, Gerard P.

    2011-01-01

    Current vaccines used for the prevention of brucellosis are ineffective in inducing protective immunity in animals that are chronically infected with Brucella abortus, such as elk. Using a gene discovery approach, in vivo-induced antigen technology (IVIAT) on B. abortus, we previously identified ten loci that encode products up-regulated during infection in elk and consequently may play a role in virulence. In our present study, five of the loci (D15, 0187, VirJ, Mdh, AfuA) were selected for ...

  6. Vimentin in Bacterial Infections

    DEFF Research Database (Denmark)

    Mak, Tim N; Brüggemann, Holger

    2016-01-01

    -vimentin interactions are presented in this review: the role of vimentin in pathogen-binding on the cell surface and subsequent bacterial invasion and the interaction of cytosolic vimentin and intracellular pathogens with regards to innate immune signaling. Mechanistic insight is presented involving distinct bacterial......Despite well-studied bacterial strategies to target actin to subvert the host cell cytoskeleton, thus promoting bacterial survival, replication, and dissemination, relatively little is known about the bacterial interaction with other components of the host cell cytoskeleton, including intermediate...... filaments (IFs). IFs have not only roles in maintaining the structural integrity of the cell, but they are also involved in many cellular processes including cell adhesion, immune signaling, and autophagy, processes that are important in the context of bacterial infections. Here, we summarize the knowledge...

  7. Cannabis and Breast feeding

    International Nuclear Information System (INIS)

    Cannabis is a drug derived from hemp plant, Cannabis sativa, used both as a recreational drug or as medicine. It is a widespread illegal substance, generally smoked for its hallucinogenic properties. Little is known about the adverse effects of postnatal cannabis exposure throw breast feeding because of a lack of studies in lactating women. The active substance of cannabis is the delta 9 Tetrahydrocannabinol (THC). Some studies conclude that it could decrease motor development of the child at one year of age. Therefore, cannabis use and abuse of other drugs like alcohol, tobacco, or cocaine must be contraindicated during breast feeding. Mothers who use cannabis must stop breast feeding, or ask for medical assistance to stop cannabis use in order to provide her baby with all the benefits of human milk.

  8. Xanthophylls in Poultry Feeding

    Science.gov (United States)

    Breithaupt, Diemar R.

    Since most consumers associate an intense colour of food with healthy animals and high food quality, xanthophylls are widely used as feed additives to generate products that meet consumers' demands. An important large-scale application is in poultry farming, where xanthophylls are added to feed to give the golden colour of egg yolk that is so much appreciated. Now, with numerous new applications in human food, in the pharmaceutical industry, and in cosmetic products, there is an increasing demand for xanthophylls on the international market (Volume 5, Chapter 4).

  9. Demonstrating Bacterial Flagella.

    Science.gov (United States)

    Porter, John R.; And Others

    1992-01-01

    Describes an effective laboratory method for demonstrating bacterial flagella that utilizes the Proteus mirabilis organism and a special harvesting technique. Includes safety considerations for the laboratory exercise. (MDH)

  10. Impact of sensory feed additives on feed intake, feed preferences, and growth of female piglets during the early postweaning period.

    Science.gov (United States)

    Clouard, C; Val-Laillet, D

    2014-05-01

    < 0.05) and 22-h (60% of total intake; P < 0.10) tests, respectively. In conclusion, feed supplementation with the FA1, FA2, and FA3 from weaning did not induce beneficial effects on feed intake and growth performance during the early postweaning period. The FA2 increased palatability and acceptance of the unfamiliar starter diet the day of feed transition, while the FA1 and FA3 increased palatability of the starter diet only after a few days of exposure, most likely through long-term familiarization processes. PMID:24668952

  11. Bacterial translocation in cirrhotic rats. Its role in the development of spontaneous bacterial peritonitis.

    OpenAIRE

    Llovet, J M; Bartolí, R; Planas, R; Cabré, E; Jimenez, M.; Urban, A; Ojanguren, I; Arnal, J; Gassull, M. A.

    1994-01-01

    Bacterial translocation occurs in ascitic cirrhotic rats, but its association with ascites infection is unknown. The aim of this study was to assess the relation between bacterial translocation and ascites infection in cirrhotic rats. Male Sprague-Dawley rats were induced to cirrhosis with intragastric CCl4. Ascitic fluid, portal and peripheral blood, mesenteric lymph nodes, liver and spleen samples were cultured before death in those cirrhotic rats with less (group A) or more (group B) than ...

  12. Two Outer Membrane Lipoproteins from Histophilus somni Are Immunogenic in Rabbits and Sheep and Induce Protection against Bacterial Challenge in Mice

    OpenAIRE

    Guzmán-Brambila, Carolina; Rojas-Mayorquín, Argelia E.; Flores-Samaniego, Beatriz; Ortuño-Sahagún, Daniel

    2012-01-01

    Histophilus somni is an economically important pathogen of cattle and other ruminants and is considered one of the key components of the bovine respiratory disease (BRD) complex, the leading cause of economic loss in the livestock industry. BRD is a multifactorial syndrome, in which a triad of agents, including bacteria, viruses, and predisposing factors or “stressors,” combines to induce disease. Although vaccines against H. somni have been used for many decades, traditional bacterins have f...

  13. 一株碳酸钙矿化菌的分离与鉴定%Isolation and Identification of a Bacterial Strain Inducing Mineralization of Calcium Carbonate

    Institute of Scientific and Technical Information of China (English)

    张振远; 李广悦; 丁德馨; 王永东; 胡南

    2014-01-01

    基于微生物诱导碳酸钙沉积的岩土工程加固技术是一种环境友好的新技术。碳酸钙矿化菌是该技术应用的前提。为获得具有诱导碳酸钙沉积能力的菌株,采用选择性富集培养、平板分离方法从土壤中分离得到了一株具有尿素分解能力的菌株,细菌诱导产生的沉积物检测结果表明该菌株具有诱导碳酸钙沉积能力。通过形态学、革兰氏染色和16 S rDNA序列同源性分析鉴定该菌株为巴斯德芽孢杆菌。%Biocementation through microbial calcium carbonate precipitation is an innova-tive and environmentally friendly rock and soil reinforcement technique in geotechnical en-gineering. The bacteria inducing mineralization of calcium carbonate is a prerequisite to im-plement the biological treatment process. In order to obtain the strain with ability to induce CaCO3 precipitation,a ureolytic strain was isolated from soil using selective enrichment cul-ture and plate screening techniques. The precipites induced by this stain were examined, and the results showed it was capable of inducing calcium carbonate mineralization. The strain was identified as Sporosarcina pasteurii based on morphology,Gram stain and 16S rDNA sequence analysis.

  14. Verapamil, and Its Metabolite Norverapamil, Inhibit Macrophage-induced, Bacterial Efflux Pump-mediated Tolerance to Multiple Anti-tubercular Drugs

    OpenAIRE

    Adams, Kristin N.; Szumowski, John D.; Ramakrishnan, Lalita

    2014-01-01

    Drug tolerance likely represents an important barrier to tuberculosis treatment shortening. We previously implicated the Mycobacterium tuberculosis efflux pump Rv1258c as mediating macrophage-induced tolerance to rifampicin and intracellular growth. In this study, we infected the human macrophage-like cell line THP-1 with drug-sensitive and drug-resistant M. tuberculosis strains and found that tolerance developed to most antituberculosis drugs, including the newer agents moxifloxacin, PA-824,...

  15. Feed sources for livestock

    NARCIS (Netherlands)

    Zanten, van H.H.E.

    2016-01-01

    Production of food has re-emerged at the top of the global political agenda, driven by two contemporary challenges: the challenge to produce enough nutritious food to feed a growing and more prosperous human population, and the challenge to produce this food in an environmentally sustainable way. Cu

  16. Bacterial colonization and gut development in preterm neonates.

    Science.gov (United States)

    Cilieborg, Malene S; Boye, Mette; Sangild, Per T

    2012-03-01

    Necrotizing enterocolitis (NEC) develops in 5-10% of preterm infants in association with enteral feeding and bacterial colonization. It remains unclear how diet and bacteria interact to protect or provoke the immature gastrointestinal tract. Understanding the factors that control bacterial colonization may provide the clue to prevent NEC, and studies in infants must be combined with animal models to understand the mechanisms of the microbiota-epithelium interactions. Analyses of infant fecal samples show that the density and distribution of bacterial species are highly variable with no consistent effects of gestational age, delivery mode, diet or probiotic administration, while low bacterial diversity and bacterial overgrowth are commonly associated with NEC. A series of recent studies in preterm pigs show that the mucosa-associated microbiota is affected by delivery method, prematurity and NEC progression and that diet has limited effects. Overgrowth of specific groups (e.g. Clostridia) appears to be a consequence of NEC, rather than the cause of NEC. Administration of probiotics either decreases or increases NEC sensitivity in preterm pigs, while in preterm infants probiotics have generally decreased NEC incidence and overall mortality. The optimal nature and amount of probiotic bacteria are unknown and host defense factors appear more important for NEC sensitivity than the nature of the gut microbiota. Host defense is improved by feeding the optimal amount of enteral diets, such as mother's colostrum or milk, that help the immature intestinal immune system to respond appropriately to the highly variable bacterial colonization. PMID:22284985

  17. Impact of feed spacer and membrane modification by hydrophilic, bactericidal and biocidal coating on biofouling control

    KAUST Repository

    Araújo, Paula A.

    2012-06-01

    The influence of polydopamine- and polydopamine-. graft-poly(ethylene glycol)-coated feed spacers and membranes, copper-coated feed spacers, and commercially-available biostatic feed spacers on biofouling has been studied in membrane fouling simulators. Feed spacers and membranes applied in practical membrane filtration systems were used; biofouling development was monitored by feed channel pressure drop increase and biomass accumulation. Polydopamine and polydopamine-. g-PEG are hydrophilic surface modification agents expected to resist protein and bacterial adhesion, while copper feed spacer coatings and biocides infused in feed spacers are expected to restrict biological growth. Our studies showed that polydopamine and polydopamine-. g-PEG coatings on feed spacers and membranes, copper coatings on feed spacers, and a commercial biostatic feed spacer did not have a significant impact on feed channel pressure drop increase and biofilm accumulation as measured by ATP and TOC content. The studied spacer and membrane modifications were not effective for biofouling control; it is doubtful that feed spacer and membrane modification, in general, may be effective for biofouling control regardless of the type of applied coating. © 2012 Elsevier B.V.

  18. Shuffling bacterial metabolomes

    OpenAIRE

    Thomason, Brendan; Read, Timothy D.

    2006-01-01

    Horizontal gene transfer (HGT) has a far more significant role than gene duplication in bacterial evolution. This has recently been illustrated by work demonstrating the importance of HGT in the emergence of bacterial metabolic networks, with horizontally acquired genes being placed in peripheral pathways at the outer branches of the networks.

  19. Vimentin in Bacterial Infections.

    Science.gov (United States)

    Mak, Tim N; Brüggemann, Holger

    2016-01-01

    Despite well-studied bacterial strategies to target actin to subvert the host cell cytoskeleton, thus promoting bacterial survival, replication, and dissemination, relatively little is known about the bacterial interaction with other components of the host cell cytoskeleton, including intermediate filaments (IFs). IFs have not only roles in maintaining the structural integrity of the cell, but they are also involved in many cellular processes including cell adhesion, immune signaling, and autophagy, processes that are important in the context of bacterial infections. Here, we summarize the knowledge about the role of IFs in bacterial infections, focusing on the type III IF protein vimentin. Recent studies have revealed the involvement of vimentin in host cell defenses, acting as ligand for several pattern recognition receptors of the innate immune system. Two main aspects of bacteria-vimentin interactions are presented in this review: the role of vimentin in pathogen-binding on the cell surface and subsequent bacterial invasion and the interaction of cytosolic vimentin and intracellular pathogens with regards to innate immune signaling. Mechanistic insight is presented involving distinct bacterial virulence factors that target vimentin to subvert its function in order to change the host cell fate in the course of a bacterial infection. PMID:27096872

  20. Prevention of bacterial adhesion

    DEFF Research Database (Denmark)

    Klemm, Per; Vejborg, Rebecca Munk; Hancock, Viktoria

    2010-01-01

    Management of bacterial infections is becoming increasingly difficult due to the emergence and increasing prevalence of bacterial pathogens that are resistant to available antibiotics. Conventional antibiotics generally kill bacteria by interfering with vital cellular functions, an approach that ...... become valuable weapons for preventing pathogen contamination and fighting infectious diseases in the future....

  1. Vimentin in Bacterial Infections

    Directory of Open Access Journals (Sweden)

    Tim N. Mak

    2016-04-01

    Full Text Available Despite well-studied bacterial strategies to target actin to subvert the host cell cytoskeleton, thus promoting bacterial survival, replication, and dissemination, relatively little is known about the bacterial interaction with other components of the host cell cytoskeleton, including intermediate filaments (IFs. IFs have not only roles in maintaining the structural integrity of the cell, but they are also involved in many cellular processes including cell adhesion, immune signaling, and autophagy, processes that are important in the context of bacterial infections. Here, we summarize the knowledge about the role of IFs in bacterial infections, focusing on the type III IF protein vimentin. Recent studies have revealed the involvement of vimentin in host cell defenses, acting as ligand for several pattern recognition receptors of the innate immune system. Two main aspects of bacteria-vimentin interactions are presented in this review: the role of vimentin in pathogen-binding on the cell surface and subsequent bacterial invasion and the interaction of cytosolic vimentin and intracellular pathogens with regards to innate immune signaling. Mechanistic insight is presented involving distinct bacterial virulence factors that target vimentin to subvert its function in order to change the host cell fate in the course of a bacterial infection.

  2. Melter feed system 3-way feed valve Auma motorized operator

    International Nuclear Information System (INIS)

    This document discusses the Scale Melter currently testing feed systems. One component of that system is a valve operator, which directs the feed slurry or flush water through the 3-way ball valve to the melter. This valve operator may be causing problems on the TNX Scale Melter by failing to accurately align the feed valve ports

  3. Laboratory observations on the feeding behavior and feeding rate of the nemertean Procephalothrix simulus.

    Science.gov (United States)

    Wang, Haiyan; Sun, Shichun; Li, Qinglong

    2008-04-01

    The feeding behavior of the nemertean Procephalothrix simulus and the effects of extrinsic factors on the feeding rates of this nemertean were experimentally studied. Procephalothrix simulus showed a typical macrophagous feeding strategy and consumed various food items. When capturing freshwater Tubifex sp., the nemerteans successfully ingested prey in all attacks, and they did not evert the proboscis in 25% of capture events. When capturing marine Saccocirrus gabrillae, the nemerteans failed to consume prey in more than half of the attacks, and they always everted the proboscis. There was a positive relationship between nemertean body weight and the rate of successful attacks, and a negative relationship between nemertean body weight and the duration of feeding events. The feeding rate of P. simulus increased when the temperature was raised from 5 degrees C to 30 degrees C but was significantly inhibited at 32 degrees C. Food intake was significantly reduced in media diluted to a practical salinity of 20 and 10 and in medium with the salinity elevated to 45. Dark conditions induced higher food intake, but prey density had no significant effect on feeding rate. These results suggest that P. simulus is a predator successfully adapted to the variable environmental conditions of the intertidal habitat. PMID:18400998

  4. Danger of zooplankton feeding

    DEFF Research Database (Denmark)

    Kiørboe, Thomas; Jiang, H.; Colin, S.P.

    2010-01-01

    therefore perform occasional upward repositioning jumps. We quantified the fluid disturbance generated by repositioning jumps in a millimetre-sized copepod (Re ∼ 40). The kick of the swimming legs generates a viscous vortex ring in the wake; another ring of similar intensity but opposite rotation is formed...... around the decelerating copepod. A simple analytical model, that of an impulsive point force, properly describes the observed flow field as a function of the momentum of the copepod, including the translation of the vortex and its spatial extension and temporal decay. We show that the time-averaged fluid...... signal and the consequent predation risk is much less for an ambush-feeding than a cruising or hovering copepod for small individuals, while the reverse is true for individuals larger than about 1 mm. This makes inefficient ambush feeding feasible in small copepods, and is consistent with the observation...

  5. A History of Infant Feeding

    OpenAIRE

    Stevens, Emily E.; Patrick, Thelma E.; Pickler, Rita

    2009-01-01

    The historical evolution of infant feeding includes wet nursing, the feeding bottle, and formula use. Before the invention of bottles and formula, wet nursing was the safest and most common alternative to the natural mother's breastmilk. Society's negative view of wet nursing, combined with improvements of the feeding bottle, the availability of animal's milk, and advances in formula development, gradually led to the substitution of artificial feeding for wet nursing. In addition, the adverti...

  6. Feeding the City

    OpenAIRE

    Roncaglia, Sara; Giorgio Solinas, Pier

    2015-01-01

    Every day in Mumbai 6,000 dabbawalas (literally translated as "those who carry boxes") distribute a staggering 200,000 home-cooked lunchboxes to the city's workers and students. Giving employment and status to thousands of largely illiterate villagers from Mumbai's hinterland, this co-operative has been in operation since the late nineteenth century. It provides one of the most efficient delivery networks in the world: only one lunch in six million goes astray. Feeding the City is an ethnogr...

  7. Feed sources for livestock

    OpenAIRE

    Zanten, van, J.H.

    2016-01-01

    Production of food has re-emerged at the top of the global political agenda, driven by two contemporary challenges: the challenge to produce enough nutritious food to feed a growing and more prosperous human population, and the challenge to produce this food in an environmentally sustainable way. Current levels of production of especially animal-source food (ASF), pose severe pressure on the environment via their emissions to air, water, and soil; and their use of scarce resources, such as la...

  8. Residual Feed Intake

    OpenAIRE

    Sainz, Roberto D.; Paulino, Pedro V.

    2004-01-01

    Introduction Low rates of return on investment for livestock operations are a fact of life. Producers have little impact on the market price for their cattle; therefore management must be focused on the things producers can actually do something about. For many years, genetic selection programs have focused on production (output) traits, with little attention given to production costs (inputs). Recently, this view has begun to change, and the efficiency of conversion of feed (i.e., t...

  9. Bacterial mutagenicity assays: test methods.

    Science.gov (United States)

    Gatehouse, David

    2012-01-01

    The most widely used assays for detecting chemically induced gene mutations are those employing bacteria. The plate incorporation assay using various Salmonella typhimurium LT2 and E. coli WP2 strains is a short-term bacterial reverse mutation assay specifically designed to detect a wide range of chemical substances capable of causing DNA damage leading to gene mutations. The test is used worldwide as an initial screen to determine the mutagenic potential of new chemicals and drugs.The test uses several strains of S. typhimurium which carry different mutations in various genes of the histidine operon, and E. coli which carry the same AT base pair at the critical mutation site within the trpE gene. These mutations act as hot spots for mutagens that cause DNA damage via different mechanisms. When these auxotrophic bacterial strains are grown on a minimal media agar plates containing a trace of the required amino-acid (histidine or tryptophan), only those bacteria that revert to amino-acid independence (His(+) or Tryp(+)) will grow to form visible colonies. The number of spontaneously induced revertant colonies per plate is relatively constant. However, when a mutagen is added to the plate, the number of revertant colonies per plate is increased, usually in a dose-related manner.This chapter provides detailed procedures for performing the test in the presence and absence of a metabolic activation system (S9-mix), including advice on specific assay variations and any technical problems. PMID:22147566

  10. Clogging of feeding tubes.

    Science.gov (United States)

    Marcuard, S P; Perkins, A M

    1988-01-01

    This is a report of an in vitro study evaluating clotting ability of some formulas with intact protein and hydrolyzed protein sources in a series of buffers ranging from a pH of 1 thru 10. The following 10 products were tested: Ensure Plus, Ensure, Enrich, Osmolite, Pulmocare, Citrotein, Resource, Vivonex TEN, Vital, and Hepatic Acid II. Protein (10 and 20 g/liter) was added to Citrotein and Ensure Plus. All formulas were tested at full and some at half strength. Clotting occurred only in premixed intact protein formulas (Pulmocare, Ensure Plus, Osmolite, Enrich, Ensure) and in Resource. No clotting was observed for Citrotein (intact protein formula in powder form), Vital, Vivonex TEN, and Hepatic Aid II. Adding protein did not cause or increase clotting. In summary, clotting of some liquid formula diet appears to be an important factor causing possible gastric feeding tube occlusion. The following measures may help in preventing this problem: flushing before and after aspirating for gastric residuals to eliminate acid precipitation of formula in the feeding tube, advance the nasogastric feeding tube into the duodenum if possible, and avoid mixing these products with liquid medications having a pH value of 5.0 or less. PMID:3138452

  11. Food Safety Information RSS feed

    Data.gov (United States)

    U.S. Department of Health & Human Services — This is an RSS Feed of Food Safety information that’s produced in real-time by the CDC. This RSS feed is the integration of two other XML feeds, one from the USDA's...

  12. Coupling between crossed dipole feeds

    DEFF Research Database (Denmark)

    Andersen, J.; Schjær-Jacobsen, Hans; Lessow, H.

    1974-01-01

    function of orientation and feeding network properties. The antennas are used as feeds for a parabolic reflector, and the effect of coupling on the secondary fields is analyzed. Especially significant is the polarization loss and it may, to some extent, be reduced by a proper choice of feeding network....

  13. OxyR and SoxR modulate the inducible oxidative stress response and are implicated during different stages of infection for the bacterial phytopathogen Pantoea stewartii subsp. stewartii.

    Science.gov (United States)

    Burbank, Lindsey; Roper, M Caroline

    2014-05-01

    Reactive oxygen species (ROS) from a variety of sources are often encountered by invading plant pathogens during the infection process. Pantoea stewartii subsp. stewartii, the etiological agent of Stewart's wilt, is a serious bacterial pathogen of sweet corn that colonizes both the apoplast and xylem tissues in which ROS are produced. The P. stewartii genome predicts the presence of two redox-sensing transcriptional regulators, OxyR and SoxR, which both activate gene expression in response to oxidative stress. ROS exposure in the form of hydrogen peroxide and the superoxide-generating compound paraquat initiates an induced stress response through OxyR and SoxR that includes activation of the ROS-detoxifying enzymes alkyl hydroperoxide reductase and superoxide dismutase. P. stewartii ΔsoxR was more sensitive to paraquat and was compromised in the ability to form water-soaked lesions, while ΔoxyR was more sensitive to hydrogen peroxide treatment and was deficient in exopolysaccharide production and the elicitation of wilting symptoms. This demonstrates that both SoxR and OxyR play an important role in virulence in the different niches that P. stewartii colonize during the infection process. PMID:24450773

  14. Increased airway glucose increases airway bacterial load in hyperglycaemia.

    Science.gov (United States)

    Gill, Simren K; Hui, Kailyn; Farne, Hugo; Garnett, James P; Baines, Deborah L; Moore, Luke S P; Holmes, Alison H; Filloux, Alain; Tregoning, John S

    2016-01-01

    Diabetes is associated with increased frequency of hospitalization due to bacterial lung infection. We hypothesize that increased airway glucose caused by hyperglycaemia leads to increased bacterial loads. In critical care patients, we observed that respiratory tract bacterial colonisation is significantly more likely when blood glucose is high. We engineered mutants in genes affecting glucose uptake and metabolism (oprB, gltK, gtrS and glk) in Pseudomonas aeruginosa, strain PAO1. These mutants displayed attenuated growth in minimal medium supplemented with glucose as the sole carbon source. The effect of glucose on growth in vivo was tested using streptozocin-induced, hyperglycaemic mice, which have significantly greater airway glucose. Bacterial burden in hyperglycaemic animals was greater than control animals when infected with wild type but not mutant PAO1. Metformin pre-treatment of hyperglycaemic animals reduced both airway glucose and bacterial load. These data support airway glucose as a critical determinant of increased bacterial load during diabetes. PMID:27273266

  15. Bacterial-induced expression of RAB18 protein in Orzya sativa salinity stress and insights into molecular interaction with GTP ligand.

    Science.gov (United States)

    Jha, Yachana; Sablok, Gaurav; Subbarao, Naidu; Sudhakar, Raja; Fazil, M H U Turabe; Subramanian, R B; Squartini, Andrea; Kumar, Sunil

    2014-09-01

    In the present research, we have studied the inoculation effects of two root-associated plant growth-promoting rhizobacteria (PGPR) in rice and provide the pieces of evidence that the inoculation of the PGPR could potentially result in inducing the expression of the salt stress-related RAB18 plant gene under varying degrees of salinity stress. The sequenced putative gene of RAB18 of Oryza sativa in this study is 740 bp long, has a content of 44.4%, and a molecular weight of 492 102.00 Da. BLAST homology patterns revealed sequence similarity with the previously sequenced RAB in model plant species. We demonstrate the mode of action of this stress-related protein by performing comparative modeling of Q10RT8 (Os03g0146000 protein, homolog of the sequenced RAB18; O. sativa subsp. japonica) using energy minimization, molecular dynamic simulations, and molecular docking of a guanosine triphosphate (GTP) ligand with the protein. The docking results indicated that Ser21, Ala22, Lys25, Asp68, Ala70, Glu73, and Arg74 are important determinant residues for functional interaction with the GTP ligand. The present research contributes to the understanding of the PGPR inoculation in salinity stress. Additionally, it provides the layout of the understanding of the molecular interactions between RAB and GTP ligand. PMID:25042706

  16. Fluorescent turn-on sensing of bacterial lipopolysaccharide in artificial urine sample with sensitivity down to nanomolar by tetraphenylethylene based aggregation induced emission molecule.

    Science.gov (United States)

    Jiang, Guoyu; Wang, Jianguo; Yang, Yang; Zhang, Guanxin; Liu, Yaling; Lin, He; Zhang, Guilan; Li, Yongdong; Fan, Xiaolin

    2016-11-15

    A tetraphenylethylene based aggregation induced emission (AIE) probe, TPEPyE, bearing a positively charged pyridinium pendant was designed and synthesized. The positively charged TPEPyE can efficiently bind to the negatively charged lipopolysaccharide (LPS) through electrostatic interactions between the two oppositely charged species. As a result, upon the addition of LPS into the PBS solution of TPEPyE, this probe aggregated immediately onto the surface of LPS and resulted over 22-fold of fluorescence enhancement. TPEPyE exhibited good selectivity and high sensitivity toward LPS in PBS buffer solution and the detection limit was calculated to be 370 pM (3.7ng/mL). More notably, TPEPyE also retained good sensitivity and selectivity in artificial urine system (with much higher ionic strength) with the detection limit down to nanomolar. Moreover, this probe can also make a distinction between gram-positive bacteria Staphylococcus aureus (S. aureus) and gram-negative bacteria Escherichia coli (E. coli), making it a promising sensor for clinical monitoring of urinary tract infections. PMID:27155117

  17. IS INFANT FEEDING ON COMPLEMENTARY FOOD REQUIRES ADDITIONAL PREBIOTICS?

    Directory of Open Access Journals (Sweden)

    Befikadu Tariku

    2012-12-01

    Full Text Available Bacteria are normal inhabitants of the gastrointestinal tract, where more than 400 bacterial species are found. Bacterial colonization of the gut begins at birth, as newborns are maintained in a sterile status until the delivery begins, and continues throughout life, with notable age-specific changes. Human milk oligosaccharides are complex glycans that are highly abundant in human breast milk. It is generally accepted that human milk oligosaccharides have prebiotic effects, selectively serving as a source of energy and nutrients for desired bacteria to colonize the infant intestine. The concentration and composition of oligosaccharides varied, indicates that the protective ability of breast milk based on human milk oligosaccharides vary. Prebiotic is commonly tested on infants not started complementary food as ingredients in formula and in adults. This review was intended to describe the outcomes of the prebiotic on the infants of complementary feeding age range and their tolerance to it. The study tried to identify articles published on the prebiotic and infants with complementary feeding age range. There were four studies on the complementary feeding age range of infants about the tolerance and effect of prebiotics use. Based on the gastrointestinal symptoms finding of the studies, the addition of the prebiotics were tolerated. All studies were based on the supplementation of the prebiotics to the formula or cereals. There is a need to identify the effect of addition of prebiotics to the infants of breastfeeding during introduction of complementary feeding, both by supplementation and based on the foods containing prebiotics.

  18. Bacterial Wound Culture

    Science.gov (United States)

    ... Home Visit Global Sites Search Help? Bacterial Wound Culture Share this page: Was this page helpful? Also known as: Aerobic Wound Culture; Anaerobic Wound Culture Formal name: Culture, wound Related ...

  19. Bacterial Meningitis in Infants

    Directory of Open Access Journals (Sweden)

    J Gordon Millichap

    2004-04-01

    Full Text Available A retrospective study of 80 infantile patients (ages 30-365 days; 47 male, 33 female with culture-proven bacterial meningitis seen over a 16 year period (1986-2001 is reported from Taiwan.

  20. An actualistic perspective into Archean worlds - (cyano-)bacterially induced sedimentary structures in the siliciclastic Nhlazatse Section, 2.9 Ga Pongola Supergroup, South Africa.

    Science.gov (United States)

    Noffke, N; Beukes, N; Bower, D; Hazen, R M; Swift, D J P

    2008-01-01

    Extensive microbial mats colonize sandy tidal flats that form along the coasts of today's Earth. The microbenthos (mainly cyanobacteria) respond to the prevailing physical sediment dynamics by biostabilization, baffling and trapping, as well as binding. This biotic-physical interaction gives rise to characteristic microbially induced sedimentary structures (MISS) that differ greatly from both purely physical structures and from stromatolites. Actualistic studies of the MISS on modern tidal flats have been shown to be the key for understanding equivalent fossil structures that occur in tidal and shelf sandstones of all Earth ages. However, until now the fossil record of Archean MISS has been poor, and relatively few specimens have been found. This paper describes a study location that displays a unique assemblage with a multitude of exceptionally preserved MISS in the 2.9-Ga-old Pongola Supergroup, South Africa. The 'Nhlazatse Section' includes structures such as 'erosional remnants and pockets', 'multidirected ripple marks', 'polygonal oscillation cracks', and 'gas domes'. Optical and geochemical analyses support the biogenicity of microscopic textures such as filamentous laminae or 'orientated grains'. Textures resembling filaments are lined by iron oxide and hydroxides, as well as clay minerals. They contain organic matter, whose isotope composition is consistent with carbon of biological origin. The ancient tidal flats of the Nhlazatse Section record four microbial mat facies that occur in modern tidal settings as well. We distinguish endobenthic and epibenthic microbial mats, including planar, tufted, and spongy subtypes. Each microbial mat facies is characterized by a distinct set of MISS, and relates to a typical tidal zone. The microbial mat structures are preserved in situ, and are consistent with similar features constructed today by benthic cyanobacteria. However, other mat-constructing microorganisms also could have formed the structures in the Archean

  1. Sub-chronic exposure to the insecticide dimethoate induces a proinflammatory status and enhances the neuroinflammatory response to bacterial lypopolysaccharide in the hippocampus and striatum of male mice

    International Nuclear Information System (INIS)

    Dimethoate is an organophosphorus insecticide extensively used in horticulture. Previous studies have shown that the administration of dimethoate to male rats, at a very low dose and during a sub-chronic period, increases the oxidation of lipids and proteins, reduces the levels of antioxidants and impairs mitochondrial function in various brain regions. In this study, we have assessed in C57Bl/6 adult male mice, whether sub-chronic (5 weeks) intoxication with a low dose of dimethoate (1.4 mg/kg) affects the expression of inflammatory molecules and the reactivity of microglia in the hippocampus and striatum under basal conditions and after an immune challenge caused by the systemic administration of lipopolysaccharide. Dimethoate increased mRNA levels of tumor necrosis factor α (TNFα) and interleukin (IL) 6 in the hippocampus, and increased the proportion of Iba1 immunoreactive cells with reactive phenotype in dentate gyrus and striatum. Lipopolysaccharide caused a significant increase in the mRNA levels of IL1β, TNFα, IL6 and interferon-γ-inducible protein 10, and a significant increase in the proportion of microglia with reactive phenotype in the hippocampus and the striatum. Some of the effects of lipopolysaccharide (proportion of Iba1 immunoreactive cells with reactive phenotype and IL6 mRNA levels) were amplified in the animals treated with dimethoate, but only in the striatum. These findings indicate that a sub-chronic period of administration of a low dose of dimethoate, comparable to the levels of the pesticide present as residues in food, causes a proinflammatory status in the brain and enhances the neuroinflammatory response to the lipopolysaccharide challenge with regional specificity. - Highlights: • The dose of pesticide used was comparable to the levels of residues found in food. • Dimethoate administration increased cytokine expression and microglia reactivity. • Hippocampus and striatum were differentially affected by the treatment.

  2. Sub-chronic exposure to the insecticide dimethoate induces a proinflammatory status and enhances the neuroinflammatory response to bacterial lypopolysaccharide in the hippocampus and striatum of male mice

    Energy Technology Data Exchange (ETDEWEB)

    Astiz, Mariana, E-mail: marianaastiz@gmail.com; Diz-Chaves, Yolanda, E-mail: ydiz@cajal.csic.es; Garcia-Segura, Luis M., E-mail: lmgs@cajal.csic.es

    2013-10-15

    Dimethoate is an organophosphorus insecticide extensively used in horticulture. Previous studies have shown that the administration of dimethoate to male rats, at a very low dose and during a sub-chronic period, increases the oxidation of lipids and proteins, reduces the levels of antioxidants and impairs mitochondrial function in various brain regions. In this study, we have assessed in C57Bl/6 adult male mice, whether sub-chronic (5 weeks) intoxication with a low dose of dimethoate (1.4 mg/kg) affects the expression of inflammatory molecules and the reactivity of microglia in the hippocampus and striatum under basal conditions and after an immune challenge caused by the systemic administration of lipopolysaccharide. Dimethoate increased mRNA levels of tumor necrosis factor α (TNFα) and interleukin (IL) 6 in the hippocampus, and increased the proportion of Iba1 immunoreactive cells with reactive phenotype in dentate gyrus and striatum. Lipopolysaccharide caused a significant increase in the mRNA levels of IL1β, TNFα, IL6 and interferon-γ-inducible protein 10, and a significant increase in the proportion of microglia with reactive phenotype in the hippocampus and the striatum. Some of the effects of lipopolysaccharide (proportion of Iba1 immunoreactive cells with reactive phenotype and IL6 mRNA levels) were amplified in the animals treated with dimethoate, but only in the striatum. These findings indicate that a sub-chronic period of administration of a low dose of dimethoate, comparable to the levels of the pesticide present as residues in food, causes a proinflammatory status in the brain and enhances the neuroinflammatory response to the lipopolysaccharide challenge with regional specificity. - Highlights: • The dose of pesticide used was comparable to the levels of residues found in food. • Dimethoate administration increased cytokine expression and microglia reactivity. • Hippocampus and striatum were differentially affected by the treatment.

  3. Effect of Sample Preparation on the Discrimination of Bacterial Isolates Cultured in Liquid Nutrient Media Using Laser-Induced Breakdown Spectroscopy (LIBS).

    Science.gov (United States)

    Gamble, Gary R; Park, Bosoon; Yoon, Seung-Chul; Lawrence, Kurt C

    2016-03-01

    Laser-induced breakdown spectroscopy (LIBS) is used as the basis for discrimination between two genera of gram-negative bacteria and two genera of gram-positive bacteria representing pathogenic threats commonly found in poultry processing rinse waters. Because LIBS-based discrimination relies primarily upon the relative proportions of inorganic cell components including Na, K, Mg, and Ca, this study aims to determine the effects of trace mineral content and pH found in the water source used to isolate the bacteria upon the reliability of the resulting discriminant analysis. All four genera were cultured using tryptic soy agar (TSA) as the nutrient medium, and were grown under identical environmental conditions. The only variable introduced is the source water used to isolate the cultured bacteria. Cultures of each bacterium were produced using deionized (DI) water under two atmosphere conditions, reverse osmosis (RO) water, tap water, phosphate buffered saline (PBS) water, and TRIS buffered water. After 3 days of culture growth, the bacteria were centrifuged and washed three times in the same water source. Bacteria were then freeze dried, mixed with microcrystalline cellulose, and a pellet was made for LIBS analysis. Principal component analysis (PCA) was used to extract related variations in LIBS spectral data among the four bacteria genera and six water types used to isolate the bacteria, and Mahalanobis discriminant analysis (MDA) was used for classification. Results indicate not only that the four genera can be discriminated from each other in each water type, but that each genus can be discriminated by water type used for isolation. It is concluded that in order for LIBS to be a reliable and repeatable method for discrimination of bacteria grown in liquid nutrient media, care must be taken to insure that the water source used in purification of the culture be precisely controlled regarding pH, ionic strength, and proportionate amounts of mineral cations

  4. Calibrating bacterial evolution

    OpenAIRE

    Ochman, Howard; Elwyn, Susannah; Moran, Nancy A

    1999-01-01

    Attempts to calibrate bacterial evolution have relied on the assumption that rates of molecular sequence divergence in bacteria are similar to those of higher eukaryotes, or to those of the few bacterial taxa for which ancestors can be reliably dated from ecological or geological evidence. Despite similarities in the substitution rates estimated for some lineages, comparisons of the relative rates of evolution at different classes of nucleotide sites indicate no basis for their universal appl...

  5. First feeding of larval herring

    DEFF Research Database (Denmark)

    Kiørboe, Thomas; Munk, Peter; Støttrup, Josianne

    1985-01-01

    , visual experience with potential prey organisms prior to first feeding and prey density. Herring larvae did not initiate exogenous feeding until around the time of yolk resorption. The timing of first feeding was not influenced by prior exposure to potential prey organisms during the yolk sac stage. In......The transition period from endogenous to exogenous feeding by larval herring was investigated in the laboratory for four herring stocks in order to evaluate the chances of survival at the time of fiest feeding. Observations on larval activity, feeding and growth were related to amount of yolk...... the light of these observations, the ecological significance of the yolk sac stage is discussed. Initiation of exogenous feeding was delayed by 1-4 days at a low (7.5 nauplii .cntdot. l-1) compared to a high (120 nauplii .cntdot. l-1) prey density, but even at prey densities corresponding to the lower...

  6. Enteral feeding without pancreatic stimulation

    DEFF Research Database (Denmark)

    Kaushik, Neeraj; Pietraszewski, Marie; Holst, Jens Juul;

    2005-01-01

    OBJECTIVE: All forms of commonly practiced enteral feeding techniques stimulate pancreatic secretion, and only intravenous feeding avoids it. In this study, we explored the possibility of more distal enteral infusions of tube feeds to see whether activation of the ileal brake mechanism can result...... in enteral feeding without pancreatic stimulation, with particular reference to trypsin, because the avoidance of trypsin stimulation may optimize enteral feeding in acute pancreatitis. METHODS: The pancreatic secretory responses to feeding were studied in 36 healthy volunteers by standard double...... plasma glucagon-like peptide-1 and peptide YY concentrations. CONCLUSIONS: Our results suggest that enteral feeding can be given without stimulating pancreatic trypsin secretion provided it is delivered into the mid-distal jejunum. The mechanism may involve activation of the ileal brake mechanism....

  7. Radiation pasteurization of poultry feed: Preliminary results of feeding tests

    International Nuclear Information System (INIS)

    Feed used to rear farm animals for human consumption has often been implicated as a vehicle for dissemination of microbial pathogens that can adversely affect both animals or birds, and humans. Radiation pasteurization of animal feed to improve its microbiological quality should reduce the incidence of feed-borne infection in the herd or flock. This would result in safer food for the consumer, and improved economic performance of the production unit. This latter benefit is particularly important because it would directly offset the cost of treating the feed. The likelihood of occurrence, as well as the magnitude, of any improved economic performance in the herd or flock consuming the irradiated feed must be determined experimentally. Accordingly, short term feeding tests were carried out to determine the effect of radiation pasteurization of poultry feed on growth performance of young chicks. The results suggest that radiation pasteurization of poultry feed may have a beneficial effect on the feed conversion efficiency of the birds consuming that feed. 10 refs, 8 tabs

  8. Infant feeding and HIV

    Directory of Open Access Journals (Sweden)

    Ameena Ebrahim Goga

    2009-12-01

    Full Text Available Recent studies on antiretroviral prophylaxis during breastfeeding show that maternal HAART (alone or with 1,4 or 24 weeks infant prophylaxis or infant prophylaxis alone (with limited maternal prophylaxis for 6, 14 or 24 weeks reduces HIV transmission through breastmilk (postnatal transmission. Maternal postnatal regimens appear to be as efficacious as infant postnatal regimens, although one study shows a trend favouring infant nevirapine over maternal HAART (both used from 1 week to 6 months post-delivery. These new findings necessitate a review of existing PMTCT interventions, and the immediate implementation of regimens that reduce postnatal transmission - where this is feasible – to save children’s lives. In the public sector, whilst stakeholders engage in discussions about which is the best regimen to minimise postnatal transmission SSSUPPORT should be given to all HIV-positive women, as explained below, to improve infant outcomes and reduce postnatal transmission: Screen all women for HIV, Send off CD4 cell counts on all HIV-positive women, Screen all HIV-positive women for AFASS using a standardised tool (e.g. Table 3; Understand the woman’s personal and socio-cultural context; Promote exclusive or predominant breastfeeding if all AFASS criteria are not met; Promote exclusive formula feeding if all AFASS criteria are met; Organise supplies of formula milk and cotrimoxazole; Review mothers and infants in the first 3 days post-delivery, in the first two weeks postnatally and monthly thereafter, and review health and feeding practices, regardless of feeding choice, at every visit; lastly Treat all pregnant women with HAART if they meet national criteria for HAART initiation.

  9. The influence of feeding and aging on pork quality

    OpenAIRE

    Tikk, Kaja

    2007-01-01

    The objective of the present thesis was to obtain a more basic understanding on how production factors such as feeding strategies and aging of the meat influence consumer-related pork quality attributes. Especially, post mortem colour characteristics of fresh pork and flavour development including warmed-over flavour in cooked pork as a function of feeding strategies have been further elucidated in the present thesis. It was found that diet-induced progress in early post mortem muscle tempera...

  10. Oxytocin, feeding and satiety

    Directory of Open Access Journals (Sweden)

    Nancy eSabatier

    2013-03-01

    Full Text Available Oxytocin neurones have a physiological role in food intake and energy balance. Central administration of oxytocin is powerfully anorexigenic, reducing food intake and meal duration. The central mechanisms underlying this effect of oxytocin have become better understood in the past few years. Parvocellular neurones of the paraventricular nucleus project to the caudal brainstem to regulate feeding via autonomic functions including the gastrointestinal vago-vagal reflex. In contrast, magnocellular neurones of the supraoptic and paraventricular nuclei release oxytocin from their dendrites to diffuse to distant hypothalamic targets involved in satiety.The ventromedial hypothalamus, for example, expresses a high density of oxytocin receptors but does not contain detectable oxytocin nerve fibres. Magnocellular neurones represent targets for the anorexigenic neuropeptide α-melanocyte stimulating hormone. . In addition to homeostatic control, oxytocin may also have a role in reward-related feeding. Evidence suggests that oxytocin can selectively suppress sugar intake and that it may have a role in limiting the intake of palatable food by inhibiting the reward pathway.

  11. Advanced Liquid Feed Experiment

    Science.gov (United States)

    Distefano, E.; Noll, C.

    1993-06-01

    The Advanced Liquid Feed Experiment (ALFE) is a Hitchhiker experiment flown on board the Shuttle of STS-39 as part of the Space Test Payload-1 (STP-1). The purpose of ALFE is to evaluate new propellant management components and operations under the low gravity flight environment of the Space Shuttle for eventual use in an advanced spacecraft feed system. These components and operations include an electronic pressure regulator, an ultrasonic flowmeter, an ultrasonic point sensor gage, and on-orbit refill of an auxiliary propellant tank. The tests are performed with two transparent tanks with dyed Freon 113, observed by a camera and controlled by ground commands and an on-board computer. Results show that the electronic pressure regulator provides smooth pressure ramp-up, sustained pressure control, and the flexibility to change pressure settings in flight. The ultrasonic flowmeter accurately measures flow and detects gas ingestion. The ultrasonic point sensors function well in space, but not as a gage during sustained low-gravity conditions, as they, like other point gages, are subject to the uncertainties of propellant geometry in a given tank. Propellant transfer operations can be performed with liquid-free ullage equalization at a 20 percent fill level, gas-free liquid transfer from 20-65 percent fill level, minimal slosh, and can be automated.

  12. Impact of well intake systems on bacterial, algae, and organic carbon reduction in SWRO desalination systems, SAWACO, Jeddah, Saudi Arabia

    KAUST Repository

    Dehwah, Abdullah

    2014-07-18

    The intake system can play a significant role in improving the feed water quality and ultimately influence the performance of downstream components of the seawater reverse osmosis desalination processes. In most cases, open-ocean intakes produce poor feed water quality in terms of the abundance of naturally occurring organic matter, which increases the risk of membrane fouling. An alternative intake is the subsurface system, which is based on the riverbank filtration concept that provides natural filtration and biological treatment of the feed water prior to the entry of the water into the desalination plant. The use of subsurface intakes normally improves the raw water quality by reducing suspended solids, algae, bacterial, and dissolved organic carbon concentrations. Therefore, the risk of biofouling caused by these substances can be reduced by implementing the appropriate type of intake system. The use of well intake systems was investigated along the Red Sea shoreline of Saudi Arabia in the Jeddah region. Data were collected from a seawater reverse osmosis (SWRO) plant with a capacity of 10,000 m3/d. The well system produces feed water from an artificial-fill peninsula that was constructed atop of the seabed. Ten wells have been constructed on the peninsula for extracting raw seawater. Water samples were collected from nearby surface seawater as a reference and from selected individual wells. The percentage of algae and bacterial removal by induced filtration process was evaluated by comparison of the seawater concentrations with the well discharges. Transparent exopolymer particles and organic carbon fractions reduction was also measured. The quality of raw water extracted from the well systems was highly improved compared with the raw seawater source. It was observed that algae were virtually 100% removed and the bacterial concentration was significantly removed by the aquifer matrix. The detailed analysis of organic carbon fraction using liquid

  13. Development of Wide Band Feeds

    Science.gov (United States)

    Ujihara, H.; Ichikawa, R.

    2012-12-01

    Wide Band feeds are being developed at NICT, NAOJ, and some universities in Japan for VLBI2010, SKA, and MARBLE. SKA, the Square Kilometre Array, will comprise thousands of radio telescopes with square kilometer aperture size for radio astronomy. MARBLE consists of small portable VLBI stations developed at NICT and GSI in Japan. They all need wide band feeds with a greater than 1:10 frequency ratio. Thus we have been studying wide band feeds with dual linear polarization for these applications.

  14. Mucosal SIV vaccines comprising inactivated virus particles and bacterial adjuvants induce CD8+T-regulatory cells that suppress SIV positive CD4+cell activation and prevent SIV infection in the macaque model.

    Directory of Open Access Journals (Sweden)

    Jean Marie eAndrieu

    2014-06-01

    Full Text Available A new paradigm of mucosal vaccination against HIV infection has been investigated in the macaque model. A vaccine consisting of inactivated SIVmac239 particles together with a living bacterial adjuvant (either the Calmette & Guerin bacillus, lactobacillus plantarum or Lactobacillus rhamnosus was administered to macaques via the vaginal or oral/intragastic route. In contrast to all established human and veterinary vaccines, these three vaccine regimens did not elicit SIV-specific antibodies nor cytotoxic T-lymphocytes but induced a previously unrecognized population of non-cytolytic MHCIb/E-restricted CD8+T regulatory cells that suppressed the activation of SIV positive CD4+ T-lymphocytes. SIV reverse transcription was thereby blocked in inactivated CD4+ T-cells; the initial burst of virus replication was prevented and the vaccinated macaques were protected from a challenge infection. Three to 14 months after intragastric immunization, 24 macaques were challenged intrarectally with a high dose of SIVmac239 or with the heterologous strain SIV B670 (both strains grown on macaques PBMC. Twenty-three of these animals were found to be protected for up to 48 months while all 24 control macaques became infected. This protective effect against SIV challenge together with the concomitant identification of a robust ex-vivo correlate of protection suggests a new approach for developing an HIV vaccine in humans. The induction of this new class of CD8+ T regulatory cells could also possibly be used therapeutically for suppressing HIV replication in infected patients and this novel tolerogenic vaccine paradigm may have potential applications for treating a wide range of immune disorders and is likely to may have profound implications across immunology generally.

  15. Microbiological turbidimetric analysis of low chlortetracycline concentrations in feeds.

    Science.gov (United States)

    Ragheb, H S; Porubcan, L S

    1975-05-01

    Recovery studies in which chlortetracycline hydrochloride (CTC-HCI) standard was added to cattle and swine feed supplements at 4.09-9.99 g/ton showed lower antibiotic recovery turbidimetrically (80.6-98.7%) than by the AOAC modified standard as in 38.179(d) (91.2-98.7%) and the plain buffer as in 38.179(b) (93.8-133.0%) methods. Three feeds fortified with a commercial premix at the levels of 5.0 and 10.0 g CTC-HCI/ton showed an overall CTC-HCI recovery of 87.6-110.6% by manual turbidimetric assay. Results were 89.1-108.7% by the AOAC inactivated feed diluent standard and 95.4-125.4% by the plain buffer methods. For some sample extracts (as in cattle feed) the use of heat to stop bacterial growth in the turbidimetric method caused formation of a precipitate. Cooling of cultures to room temperature and rapid reading of sample turbidity followed by standard curve concentrations minimized this interference. The manual turbidimetric assay of low levels of CTC-HCI in feeds appears to offer advantages over other methods. PMID:1141190

  16. Bacterial meningitis in children

    International Nuclear Information System (INIS)

    To demonstrate the epidemiology, clinical manifestations and bacteriological profile of bacterial meningitis in children beyond the neonatal period in our hospital. This was a retrospective descriptive study conducted at Prince Rashid Hospital in Irbid, Jordan. The medical records of 50 children with the diagnosis of bacterial meningitis during 4 years period, were reviewed. The main cause of infection was streptococcus pneumoniae, followed by Haemophilus influenza and Niesseria meningitides. Mortality was higher in infants and meningococcal infection, while complications were more encountered in cases of streptococcus pneumoniae. Cerebrospinal fluid culture was positive in 11 cases and Latex agglutination test in 39. There is a significant reduction of the numbers of bacterial meningitis caused by Haemophilus influenza type B species. (author)

  17. Multiple part feeding

    DEFF Research Database (Denmark)

    Hvilshøj, Mads; Bøgh, Simon; Nielsen, Oluf Skov;

    2012-01-01

    Purpose - The purpose of this paper is to present experience from a real-world demonstration of autonomous industrial mobile manipulation (AIMM) based on the mobile manipulator "Little Helper" performing multiple part feeding at the pump manufacturer Grundfos A/S. Design/methodology/approach - The...... necessary AIMM technologies exist at a mature level - the reason that no mobile manipulators have yet been implemented in industrial environments, is that research in the right applications have not been carried out. We propose a pragmatic approach consisting of: a commercial-off-the-shelf (COTS) mobile....... Originality/value - The paper presents a full-scale demonstration of a state-of-the-art COTS autonomous mobile manipulator system with particular focus on industrial utilization and application....

  18. Diagnosis of bacterial vaginosis

    Directory of Open Access Journals (Sweden)

    Đukić Slobodanka

    2013-01-01

    Full Text Available Bacterial vaginosis is a common, complex clinical syndrome characterized by alterations in the normal vaginal flora. When symptomatic, it is associated with a malodorous vaginal discharge and on occasion vaginal burning or itching. Under normal conditions, lactobacilli constitute 95% of the bacteria in the vagina. Bacterial vaginosis is associated with severe reduction or absence of the normal H2O2­producing lactobacilli and overgrowth of anaerobic bacteria and Gardnerella vaginalis, Atopobium vaginae, Mycoplasma hominis and Mobiluncus species. Most types of infectious disease are diagnosed by culture, by isolating an antigen or RNA/DNA from the microbe, or by serodiagnosis to determine the presence of antibodies to the microbe. Therefore, demonstration of the presence of an infectious agent is often a necessary criterion for the diagnosis of the disease. This is not the case for bacterial vaginosis, since the ultimate cause of the disease is not yet known. There are a variety of methods for the diagnosis of bacterial vaginosis but no method can at present be regarded as the best. Diagnosing bacterial vaginosis has long been based on the clinical criteria of Amsel, whereby three of four defined criteria must be satisfied. Nugent’s scoring system has been further developed and includes validation of the categories of observable bacteria structures. Up­to­date molecular tests are introduced, and better understanding of vaginal microbiome, a clear definition for bacterial vaginosis, and short­term and long­term fluctuations in vaginal microflora will help to better define molecular tests within the broader clinical context.

  19. Small Intestinal Bacterial Overgrowth: A Case-Based Review

    OpenAIRE

    Kristen H. Reynolds

    2015-01-01

    Small intestinal bacterial overgrowth (SIBO) is a condition of increased microbial load in the small intestine. The microbes feed on dietary carbohydrates and starches via fermentation, leading to gas production, inflammation and damage to the lining of the small intestine. Clinical presentation is varied, including abdominal pain, bloating, malabsorption and systemic symptoms. SIBO is associated with many challenging and chronic conditions such as fibromyalgia, chronic fatigue and chronic pa...

  20. Interfering with bacterial gossip

    DEFF Research Database (Denmark)

    Bjarnsholt, Thomas; Tolker-Nielsen, Tim; Givskov, Michael

    2011-01-01

    defense. Antibiotics exhibit a rather limited effect on biofilms. Furthermore, antibiotics have an ‘inherent obsolescence’ because they select for development of resistance. Bacterial infections with origin in bacterial biofilms have become a serious threat in developed countries. Pseudomonas aeruginosa......, resistance and QS inhibition as future antimicrobial targets, in particular those that would work to minimize selection pressures for the development of resistant bacteria.......Biofilm resilience poses major challenges to the development of novel antimicrobial agents. Biofilm bacteria can be considered small groups of “Special Forces” capable of infiltrating the host and destroying important components of the cellular defense system with the aim of crippling the host...

  1. Brainstem metabotropic glutamate receptors reduce food intake and activate dorsal pontine and medullar structures after peripheral bacterial lipopolysaccharide administration.

    Science.gov (United States)

    Chaskiel, Léa; Paul, Flora; Gerstberger, Rüdiger; Hübschle, Thomas; Konsman, Jan Pieter

    2016-08-01

    During infection-induced inflammation food intake is reduced. Vagal and brainstem pathways are important both in feeding regulation and immune-to-brain communication. Glutamate is released by vagal afferent terminals in the nucleus of the solitary tract and by its neurons projecting to the parabrachial nuclei. We therefore studied the role of brainstem glutamate receptors in spontaneous food intake of healthy animals and during sickness-associated hypophagia after peripheral administration of bacterial lipopolysaccharides or interleukin-1beta. Brainstem group I and II metabotropic, but not ionotropic, glutamate receptor antagonism increased food intake both in saline- and lipopolysaccharide-treated rats. In these animals, expression of the cellular activation marker c-Fos in the lateral parabrachial nuclei and lipopolysaccharide-induced activation of the nucleus of the solitary tract rostral to the area postrema were suppressed. Group I metabotropic glutamate receptors did not colocalize with c-Fos or neurons regulating gastric function in these structures. Group I metabotropic glutamate receptors were, however, found on raphé magnus neurons that were part of the brainstem circuit innervating the stomach and on trigeminal and hypoglossal motor neurons. In conclusion, our findings show that brainstem metabotropic glutamate receptors reduce food intake and activate the lateral parabrachial nuclei as well as the rostral nucleus of the solitary tract after peripheral bacterial lipopolysaccharide administration. They also provide insight into potential group I metabotropic glutamate receptor-dependent brainstem circuits mediating these effects. PMID:27016016

  2. Perspectives of bacterial ACC deaminase in phytoremediation.

    Science.gov (United States)

    Arshad, Muhammad; Saleem, Muhammad; Hussain, Sarfraz

    2007-08-01

    Phytoremediation of contaminated soil and water environments is regulated and coordinated by the plant root system, yet root growth is often inhibited by pollutant-induced stress. Prolific root growth could maximize rates of hyperaccumulation of inorganic contaminants or rhizodegradation of organic pollutants, and thus accelerate phytoremediation. Accelerated ethylene production in response to stress induced by contaminants is known to inhibit root growth and is considered as a major limitation in improving phytoremediation efficiency. Recent work shows that bacterial 1-aminocyclopropane-1-carboxylate (ACC) deaminase regulates ethylene levels in plants by metabolizing its precursor ACC into alpha-ketobutyric acid and ammonia. Plants inoculated with ACC deaminase bacteria or transgenic plants that express bacterial ACC deaminase genes can regulate their ethylene levels and consequently contribute to a more extensive root system. Such proliferation of roots in contaminated soil can lead to enhanced uptake of heavy metals or rhizodegradation of xenobiotics. PMID:17573137

  3. A mathematical model for the bacterial oxidation of a sulfide ore concentrate

    Energy Technology Data Exchange (ETDEWEB)

    Nagpal, S.; Dahlstrom, D. (Univ. of Utah, Salt Lake City, UT (United States). Dept. of Chemical Engineering); Oolman, T. (Radian Corp., Austin, TX (United States))

    1994-03-05

    The effect of dilution rate and feed solids concentration on the bacterial leaching of a pyrite/arsenopyrite ore concentrate was studied. A mathematical model was developed for the process based on the steady-state data collected over the range of dilution rates (20 to 110 h) and feed solids concentrations (6 to 18% w/v) studied. A modified Monod model with inhibition by arsenic was used to model bacterial ferrous ion oxidation rates. The model assumes that (1) pyrite and arsenopyrite leaching occurs solely by the action of ferric iron produced from the bacterial oxidation of ferrous iron and (2) bacterial growth rates are proportional to ferrous ion oxidation rate. The equilibrium among the various ionic species present in the leach solution that are likely to have a significant effect on the bioleach process were included in the model.

  4. Bacterial turbulence reduction by passive magnetic particle chains

    Science.gov (United States)

    Liu, Kuo-An; I, Lin

    2013-09-01

    We report the experimental observation of the bacterial turbulence reduction in dense E. coli suspensions by increasing the coupling of passive particle additives (paramagnetic particles). Applying an external magnetic field induces magnetic dipoles for particles and causes the formation of vertical chain bundles, which are hard for bacterial flows to tilt and break. The larger effective drag coefficient of chains causes slow horizontal motion of chains, which in turn form obstacles to suppress bacterial flows through the strong correlation in coherent bacterial clusters and intercluster interaction. The interruption of the upward energy flow from individual self-propelling bacteria to the larger scale in the bacterial turbulence with multiscaled coherent flow by the chain bundle leads to more severe suppression in the low frequency (wave number) regimes of the power spectra.

  5. Bacterial Skin Infections

    Science.gov (United States)

    ... or scraped, the injury should be washed with soap and water and covered with a sterile bandage. Petrolatum may be applied to open areas to keep the tissue moist and to try to prevent bacterial invasion. Doctors recommend that people do not use ...

  6. Bacterial microflora of nectarines

    Science.gov (United States)

    Microflora of fruit surfaces has been the best source of antagonists against fungi causing postharvest decays of fruit. However, there is little information on microflora colonizing surfaces of fruits other than grapes, apples, and citrus fruit. We characterized bacterial microflora on nectarine f...

  7. 褪黑素对细菌脂多糖导致的宫内感染脑损伤的保护作用%Protective effect of melatonin on brain injury of intrauterine infection induced by bacterial lipopolysaccharide

    Institute of Scientific and Technical Information of China (English)

    刘利芬; 钱志红; 史明

    2011-01-01

    Objective: To investigate the effect of melatonin on free radical in brain tissues of fetal rats with intrauterine infection,explore the protective effect of melatonin on brain tissues of fetal rats with intrauterine infection. Methods: The models of cerebral palsy rat induced by intrauterine infection were established by injecting bacterial lipopolysaccharide into pregnant rats, melatonin intervention was carried out; the SD rats on the 19th day after pregnancy were selected as blank control group, intrauterine infection group and melatonin treatment group; the pregnant rats in intrauterine infection group were treated with intraperitoneal injection of bacterial lipopolysaccharide (500 μg/kg), and the pregnant rats in melatonin treatment group were treated with intraperitoneal injection of bacterial lipopolysaccharide (500 μg/kg) and melatonin ( 10 mg/kg); then the rats in each group were divided into 2 - hour group, 6 - hour group and 12 - hour group according to different observing times, 4 pregnant rats in each group; the pregnant rats in each group were executed at corresponding time points, then the brain tissues of fetal rats were obtained; the superoxide dismutase (SOD) activity, glutathione peroxidase (GSH -Px) activity and malondialdehyde (MDA) content in the brain tissues of fetal rats after homogenate were detected; HE staining was used to observe the pathological changes of brain tissues, and the differences among different groups were compared. Results: Compared with blank control group, SOD activity and GSH- Px activity of brain tissues of fetal rats in intrauterine infection group decreased, MDA content increased;with the extension of infection time, the above - mentioned changes became more obvious, there was significant difference; compared with intrauterine infection group, SOD activity and GSH - Px activity of brain tissues of fetal rats in melatonin treatment group increased, MDA content decreased. Conclusion: Brain injury of fetal rats with

  8. Aquaculture feed and food safety.

    Science.gov (United States)

    Tacon, Albert G J; Metian, Marc

    2008-10-01

    The ultimate objective of an aquaculture feed manufacturer and aquaculture food supplier is to ensure that the feed or food produced is both safe and wholesome. Reported food safety risks, which may be associated with the use of commercial animal feeds, including compound aquaculture feeds, usually result from the possible presence of unwanted contaminants, either within the feed ingredients used or from the external contamination of the finished feed on prolonged storage. The major animal feed contaminants that have been reported to date have included Salmonellae, mycotoxins, veterinary drug residues, persistent organic pollutants, agricultural and other chemicals (solvent residues, melamine), heavy metals (mercury, lead, cadmium) and excess mineral salts (hexavalent chromium, arsenic, selenium, flourine), and transmissible spongiform encephalopathies. Apart from the direct negative effect of these possible contaminants on the health of the cultured target species, there is a risk that the feed contaminants may be passed along the food chain, via contaminated aquaculture produce, to consumers. In recent years, public concern regarding food safety has increased as a consequence of the increasing prevalence of antibiotic residues, persistent organic pollutants, and chemicals in farmed seafood. The important role played by the Food and Agriculture Organization of the United Nations (FAO) and the Codex Alimentarius Commission in the development of international standards, guidelines, and recommendations to protect the health of consumers and ensure fair practices in the food trade is discussed. PMID:18991902

  9. Gender differences and effect of photophase on Asian citrus psyllid (Diaphorina citri Kuwayama) feeding behavior

    Science.gov (United States)

    Asian citrus psyllid, Diaphorina citri Kuwayama (Hemiptera: Psyllidae), thought to be primarily a phloem-feeding insect, transmits the presumptive pathogen for Huanglongbing, ‘Candidatus Liberibacter asiaticus’. Because this bacterium is restricted to the phloem and bacterial transmission is the res...

  10. Rumen bacterial communities can be acclimated faster to high concentrate diets than currently implemented feedlot programs

    OpenAIRE

    Anderson, C L; Schneider, C.J.; Erickson, G.E.; MacDonald, J C; Fernando, S. C.

    2016-01-01

    Abstract Aims Recent studies have demonstrated RAMP ®, a complete starter feed, to have beneficial effects for animal performance. However, how RAMP may elicit such responses is unknown. To understand if RAMP adaptation results in changes in the rumen bacterial community that can potentially affect animal performance, we investigated the dynamics of rumen bacterial community composition in corn‐adapted and RAMP‐adapted cattle. Methods and Results During gradual acclimation of the rumen bacter...

  11. Structure and Dynamics of Anaerobic Bacterial Aggregates in a Gas-Lift Reactor

    OpenAIRE

    Beeftink, H.H.; Staugaard, P

    1986-01-01

    Anaerobic mixed-culture aggregates, which converted glucose to acetic, propionic, butyric, and valeric acids, were formed under controlled conditions of substrate feed (carbon limitation) and hydraulic regimen. The continuous-flow system used (anaerobic gas-lift reactor) was designed to retain bacterial aggregates in a well-mixed reactor. Carrier availability (i.e., liquid-suspended sand grains) proved necessary for bacterial aggregate formation from individual cells during reactor start-up. ...

  12. Comparative Analysis of the Composition of Intestinal Bacterial Communities in Dastarcus helophoroides Fed Different Diets

    OpenAIRE

    Wang, Wei-Wei; He, Cai; Cui, Jun; Wang, Hai-dong; Li, Meng-Lou

    2014-01-01

    The diversity of the intestinal bacterial communities in Dastarcus helophoroides (Fairmaire) (Coleoptera: Bothrideridae) larvae and adults was assayed by PCR-DGGE to determine whether different artificial diets could influence these bacterial communities. Two diets were used for feeding the larvae and four for the adults. Escherichia, Desemzia, Staphylococcus, Asticcacaulis, Cellvibrio, Aurantimonas, and Planomicrobium were isolated from the gut of the adults, with Escherichia and Staphylococ...

  13. The bacterial communities of Drosophila suzukii collected from undamaged cherries.

    Science.gov (United States)

    Chandler, James Angus; James, Pamela M; Jospin, Guillaume; Lang, Jenna M

    2014-01-01

    Drosophila suzukii is an introduced pest insect that feeds on undamaged, attached fruit. This diet is distinct from the fallen, discomposing fruits utilized by most other species of Drosophila. Since the bacterial microbiota of Drosophila, and of many other animals, is affected by diet, we hypothesized that the bacteria associated with D. suzukii are distinct from that of other Drosophila. Using 16S rDNA PCR and Illumina sequencing, we characterized the bacterial communities of larval and adult D. suzukii collected from undamaged, attached cherries in California, USA. We find that the bacterial communities associated with these samples of D. suzukii contain a high frequency of Tatumella. Gluconobacter and Acetobacter, two taxa with known associations with Drosophila, were also found, although at lower frequency than Tatumella in four of the five samples examined. Sampling D. suzukii from different locations and/or while feeding on different fruits is needed to determine the generality of the results determined by these samples. Nevertheless this is, to our knowledge, the first study characterizing the bacterial communities of this ecologically unique and economically important species of Drosophila. PMID:25101226

  14. The bacterial communities of Drosophila suzukii collected from undamaged cherries

    Directory of Open Access Journals (Sweden)

    James Angus Chandler

    2014-07-01

    Full Text Available Drosophila suzukii is an introduced pest insect that feeds on undamaged, attached fruit. This diet is distinct from the fallen, discomposing fruits utilized by most other species of Drosophila. Since the bacterial microbiota of Drosophila, and of many other animals, is affected by diet, we hypothesized that the bacteria associated with D. suzukii are distinct from that of other Drosophila. Using 16S rDNA PCR and Illumina sequencing, we characterized the bacterial communities of larval and adult D. suzukii collected from undamaged, attached cherries in California, USA. We find that the bacterial communities associated with these samples of D. suzukii contain a high frequency of Tatumella. Gluconobacter and Acetobacter, two taxa with known associations with Drosophila, were also found, although at lower frequency than Tatumella in four of the five samples examined. Sampling D. suzukii from different locations and/or while feeding on different fruits is needed to determine the generality of the results determined by these samples. Nevertheless this is, to our knowledge, the first study characterizing the bacterial communities of this ecologically unique and economically important species of Drosophila.

  15. Rumen distension and contraction influence feed preference by sheep.

    Science.gov (United States)

    Villalba, J J; Provenza, F D; Stott, R

    2009-01-01

    Distension of the rumen limits feed intake by livestock. Ruminal dysfunctions due to bloat, which causes distension by accumulation of excessive gas within the rumen, also reduce feeding. We hypothesized that excessive levels of rumen distension cause feed aversions and that preference increases for feeds eaten in association with recovery from bloat. To test these hypotheses, we determined whether 12 commercial crossbred lambs (average initial BW of 43 +/- 2 kg) could associate ingestion of specific feeds with the consequences of increased intraruminal pressure and its subsidence. Six of the lambs were fitted with rumen cannulas and offered ground alfalfa for 30 min after a rubber balloon was inserted into the rumen of each animal and distended with air to volumes of 1.8, 2.5, or 4.5 L. Subsequently, balloons were deflated and alfalfa was offered again for a second period of 30 min. Feed intake was not affected when the balloon was not distended (P = 0.45 to 0.93), but distension reduced feed intake (P bloat-inducing plants and preferences for plants and supplements that relieve the incidence of bloat. PMID:18791142

  16. Radiation sterilization of livestock feeds

    International Nuclear Information System (INIS)

    The radiation sterilization of livestock feeds is not much used presently because the process is not known well, and the cost is relatively high. However, its effect of sterilization is absolute, the radiation-sterilized feeds are safe in both nutrition and toxicity, and do not affect the appetite of livestocks, and the radiation energy required is small. In the future, as in the sterilization of medical supplies, feed radiation sterilization plants should be established, to stabilize livestock industry and to contribute to the health control of experimental animals. The following matters are described: radiation, comparison between radiation sterilization and other sterilization methods, the practice of feed radiation sterilization, the adverse effects of radiation sterilization, economic aspect, and the situation of feed radiation sterilization in various countries. (Mori, K.)

  17. Heme uptake in bacterial pathogens

    OpenAIRE

    Contreras, Heidi; Chim, Nicholas; Credali, Alfredo; Goulding, Celia W.

    2014-01-01

    Iron is an essential nutrient for the survival of organisms. Bacterial pathogens possess specialized pathways to acquire heme from their human hosts. In this review, we present recent structural and biochemical data that provide mechanistic insights into several bacterial heme uptake pathways, encompassing the sequestration of heme from human hemoproteins to secreted or membrane-associated bacterial proteins, the transport of heme across bacterial membranes, and the degradation of heme within...

  18. Proton dynamics in bacterial spores, a neutron scattering investigation

    Directory of Open Access Journals (Sweden)

    Noue Alexandre Colas de la

    2015-01-01

    Full Text Available Results from first neutron scattering experiments on bacterial spores are reported. The elastic intensities and mean square displacements have a non-linear behaviour as function of temperature, which is in agreement with a model presenting more pronounced variations at around 330 K (57 ∘C and 400 K (127 ∘C. Based on the available literature on thermal properties of bacterial spores, mainly referring to differential scanning calorimetry, they are suggested to be associated to main endothermic transitions induced by coat and/or core bacterial response to heat treatment.

  19. Proton dynamics in bacterial spores, a neutron scattering investigation

    Science.gov (United States)

    Colas de la Noue, Alexandre; Peters, Judith; Gervais, Patrick; Martinez, Nicolas; Perrier-Cornet, Jean-Marie; Natali, Francesca

    2015-01-01

    Results from first neutron scattering experiments on bacterial spores are reported. The elastic intensities and mean square displacements have a non-linear behaviour as function of temperature, which is in agreement with a model presenting more pronounced variations at around 330 K (57 ∘C) and 400 K (127 ∘C). Based on the available literature on thermal properties of bacterial spores, mainly referring to differential scanning calorimetry, they are suggested to be associated to main endothermic transitions induced by coat and/or core bacterial response to heat treatment.

  20. Evolutionary transitions in bacterial symbiosis

    OpenAIRE

    Sachs, Joel L.; Skophammer, Ryan G.; Regus, John U.

    2011-01-01

    Diverse bacterial lineages form beneficial infections with eukaryotic hosts. The origins, evolution, and breakdown of these mutualisms represent important evolutionary transitions. To examine these key events, we synthesize data from diverse interactions between bacteria and eukaryote hosts. Five evolutionary transitions are investigated, including the origins of bacterial associations with eukaryotes, the origins and subsequent stable maintenance of bacterial mutualism with hosts, the captur...

  1. Bacterial Acclimation Inside an Aqueous Battery.

    Directory of Open Access Journals (Sweden)

    Dexian Dong

    Full Text Available Specific environmental stresses may lead to induced genomic instability in bacteria, generating beneficial mutants and potentially accelerating the breeding of industrial microorganisms. The environmental stresses inside the aqueous battery may be derived from such conditions as ion shuttle, pH gradient, free radical reaction and electric field. In most industrial and medical applications, electric fields and direct currents are used to kill bacteria and yeast. However, the present study focused on increasing bacterial survival inside an operating battery. Using a bacterial acclimation strategy, both Escherichia coli and Bacillus subtilis were acclimated for 10 battery operation cycles and survived in the battery for over 3 days. The acclimated bacteria changed in cell shape, growth rate and colony color. Further analysis indicated that electrolyte concentration could be one of the major factors determining bacterial survival inside an aqueous battery. The acclimation process significantly improved the viability of both bacteria E. coli and B. subtilis. The viability of acclimated strains was not affected under battery cycle conditions of 0.18-0.80 mA cm(-2 and 1.4-2.1 V. Bacterial addition within 1.0×10(10 cells mL(-1 did not significantly affect battery performance. Because the environmental stress inside the aqueous battery is specific, the use of this battery acclimation strategy may be of great potential for the breeding of industrial microorganisms.

  2. [Bacterial diseases of rape].

    Science.gov (United States)

    Zakharova, O M; Mel'nychuk, M D; Dankevych, L A; Patyka, V P

    2012-01-01

    Bacterial destruction of the culture was described and its agents identified in the spring and winter rape crops. Typical symptoms are the following: browning of stem tissue and its mucilagization, chlorosis of leaves, yellowing and beginning of soft rot in the place of leaf stalks affixion to stems, loss of pigmentation (violet). Pathogenic properties of the collection strains and morphological, cultural, physiological, and biochemical properties of the agents of rape's bacterial diseases isolated by the authors have been investigated. It was found that all the isolates selected by the authors are highly or moderately aggressive towards different varieties of rape. According to the complex of phenotypic properties 44% of the total number of isolates selected by the authors are related to representatives of the genus Pseudomonas, 37% - to Xanthomonas and 19% - to Pectobacterium. PMID:23293826

  3. Bacterial proteases and virulence

    DEFF Research Database (Denmark)

    Frees, Dorte; Brøndsted, Lone; Ingmer, Hanne

    Bacterial pathogens rely on proteolysis for variety of purposes during the infection process. In the cytosol, the main proteolytic players are the conserved Clp and Lon proteases that directly contribute to virulence through the timely degradation of virulence regulators and indirectly by providing...... tolerance to adverse conditions such as those experienced in the host. In the membrane, HtrA performs similar functions whereas the extracellular proteases, in close contact with host components, pave the way for spreading infections by degrading host matrix components or interfering with host cell...... cell. These extracellular proteases are activated in complex cascades involving auto-processing and proteolytic maturation. Thus, proteolysis has been adopted by bacterial pathogens at multiple levels to ensure the success of the pathogen in contact with the human host....

  4. Phosphoproteins involved in bacterial signal transduction

    International Nuclear Information System (INIS)

    Cells adjust their behavior continuously in response to changing environmental conditions. A number of specific stimulus-response systems have been investigated in bacteria. These include the chemotaxis system (Che), the nitrogen regulatory system (Ntr), the phosphorus system (Pho), the system that controls expression of outer membrane proteins (Omp) in response to changes in osmotic pressure, the sporulation system (SpoO), and the virulence system (Vir) that mediates bacterial infectivity of damaged plant tissues. Surprisingly, all of these systems show a common set of components. In each case, the signal transduction proteins include members of two homologous families, which appear to comprise a cascade: Sensory information feeds into the first component, which activates the second component that, in turn, modulates a target activity within the cell. In this paper, the authors present evidence that the communication between the two components involves a phospho-transfer mechanism that is common to all of these regulatory systems

  5. A study of bacterial gene regulatory mechanisms

    DEFF Research Database (Denmark)

    Hansen, Sabine

    GRNs this thesis also provided the first evidence of the sensor histidine kinase VC1831 being an additional player in the Vibrio cholerae quorum sensing (QS) GRN. Bacteria use a process of cell-cell communication called QS which enable the bacterial cells to collectively control their gene expression...... using small signaling molecules called autoinducers, thereby coordinating group behavior. At the heart of the V. cholerae QS response lie four small RNA (sRNA) molecules called the quorum regulatory RNAs (Qrr). This PhD thesis provides evidence that the sensor histidine kinase VC1831 is regulated by the...... Qrr sRNAs. It is further shown that VC1831 feeds back to activate the expression the Qrrs, presumably via phosphorylation of LuxU. Thus, VC1831, which responds to an unknown ligand, is a new player in the V. cholerae QS response. Prior to this report, the two autoinducer sensors CqsS and LuxQ were the...

  6. Supramolecular bacterial systems

    OpenAIRE

    Sankaran, Shrikrishnan

    2015-01-01

    For nearly over a decade, a wide variety of dynamic and responsive supramolecular architectures have been investigated and developed to address biological systems. Since the non-covalent interactions between individual molecular components in such architectures are similar to the interactions found in living systems, it was possible to integrate chemically-synthesized and naturally-occurring components to create platforms with interesting bioactive properties. Bacterial cells and recombinant ...

  7. Bacterial transformation of terpenoids

    International Nuclear Information System (INIS)

    Data on the bacterial transformation of terpenoids published in the literature in the past decade are analyzed. Possible pathways for chemo-, regio- and stereoselective modifications of terpenoids are discussed. Considerable attention is given to new technological approaches to the synthesis of terpenoid derivatives suitable for the use in the perfume and food industry and promising as drugs and chiral intermediates for fine organic synthesis. The bibliography includes 246 references

  8. Feed palatability and the alternative protein sources in shrimp feed

    Directory of Open Access Journals (Sweden)

    Chutima Tantikitti

    2014-02-01

    Full Text Available Feed palatability in carnivorous aquaculture species, shrimps in particular, has been crucially related to the presence of compounds acting as attractants that are commonly associated with the prey components under wild conditions. Thus a nutritionally adequate and organoleptically-pleasing diet is essential to achieve satisfactory intake and growth in shrimps. Historically, fishmeal has been an essential dietary component of intensive shrimp cultures because of its nutrient composition and compounds of high attractability. However, in recent years the fishmeal supplies have been dwindling due to over hunting, a diminishing natural fish-stock, elevating prices and market volatility. This has led to search for cheaper sources of suitable protein as fishmeal substitutes. To improve the palatability of diets, various substances have been investigated for their effectiveness in aqua-feed including natural feed ingredients and synthetic flavor substances. For crustacean, attractants characteristically are of low molecular weight, water and ethanol soluble, and amphoteric or basic compounds that are released from potential prey items. Compounds such as free amino acids, especially taurine, hydroxyproline, glycine, arginine, glutamic acid and alanine have been identified to stimulate feeding in shrimps. The same has been identified with organic acids, nucleotides and nucleosides, betaine, and some small peptides. Palatability also has been associated with animal’s past experience with the feed. Understanding the factors that regulate feed palatability is therefore primary for successful shrimp culture.

  9. Supporting the Breast-feeding Dyad

    OpenAIRE

    Ellis, Donelda

    1986-01-01

    Although there has been a resurgence of breast-feeding in the last decade, 50% of women discontinue exclusive breast-feeding by the third month postpartum. Practices known to interfere with breast-feeding are often begun in hospital and continued at home. The physiology of lactation, the need for interaction between mother and infant during breast-feeding, and research findings indicate that scheduled feeds, feeds of limited duration, supplementation, and separation of mothers and infants int...

  10. Long-term Hg pollution induced Hg tolerance in the terrestrial isopod Porcellio scaber (Isopoda, Crustacea)

    International Nuclear Information System (INIS)

    The aim of our work was to assess the pollution-induced community tolerance (PICT) of isopod gut microbiota and pollution-induced isopod population tolerance (PIPT). Animals collected from a chronically Hg polluted and an unpolluted location were exposed for 14 days to 10 μg Hg/g dry food under laboratory conditions. The lysosomal membrane stability, hepatopancreas epithelium thickness, feeding activity and animal bacterial gut microbiota composition were determined. The results confirm the hypothesis that the response to short-term Hg exposure differs for animals from the Hg polluted and the unpolluted field locations. The animals and their gut microbiota from the Hg polluted location were less affected by Hg in a short-term feeding experiment than those from the unpolluted environment. We discuss the pollution-induced population tolerance of isopods and their gut microbiota as a measure of effects of long-term environmental pollution. The ecological consequences of such phenomena are also discussed. - Isopods (Porcellio scaber) as well as their bacterial gut community from a mercury-polluted site are mercury tolerant

  11. Long-term Hg pollution induced Hg tolerance in the terrestrial isopod Porcellio scaber (Isopoda, Crustacea)

    Energy Technology Data Exchange (ETDEWEB)

    Lapanje, A. [University of Ljubljana, Biotechnical Faculty, Department of Biology, Vecna pot 111, 1000 Ljubljana (Slovenia); Institute of Physical Biology, Veliko Mlacevo 59, 1290 Grosuplje (Slovenia)], E-mail: ales.lapanje@bf.uni-lj.si; Drobne, D. [University of Ljubljana, Biotechnical Faculty, Department of Biology, Vecna pot 111, 1000 Ljubljana (Slovenia); Nolde, N. [Institute Jozef Stefan, Department of Environmental Sciences, Jamova 39, 1000 Ljubljana (Slovenia); Valant, J. [University of Ljubljana, Biotechnical Faculty, Department of Biology, Vecna pot 111, 1000 Ljubljana (Slovenia); Muscet, B. [Institute of Physical Biology, Veliko Mlacevo 59, 1290 Grosuplje (Slovenia); Leser, V. [University of Ljubljana, Biotechnical Faculty, Department of Biology, Vecna pot 111, 1000 Ljubljana (Slovenia); Rupnik, M. [Institute of Public Health, Prvomajska 1, 2000 Maribor (Slovenia); Faculty of Medicine, University of Maribor, Slomskov trg 15, 2000 Maribor (Slovenia)

    2008-06-15

    The aim of our work was to assess the pollution-induced community tolerance (PICT) of isopod gut microbiota and pollution-induced isopod population tolerance (PIPT). Animals collected from a chronically Hg polluted and an unpolluted location were exposed for 14 days to 10 {mu}g Hg/g dry food under laboratory conditions. The lysosomal membrane stability, hepatopancreas epithelium thickness, feeding activity and animal bacterial gut microbiota composition were determined. The results confirm the hypothesis that the response to short-term Hg exposure differs for animals from the Hg polluted and the unpolluted field locations. The animals and their gut microbiota from the Hg polluted location were less affected by Hg in a short-term feeding experiment than those from the unpolluted environment. We discuss the pollution-induced population tolerance of isopods and their gut microbiota as a measure of effects of long-term environmental pollution. The ecological consequences of such phenomena are also discussed. - Isopods (Porcellio scaber) as well as their bacterial gut community from a mercury-polluted site are mercury tolerant.

  12. Butyrate enhances disease resistance of chickens by inducing antimicrobial host defense peptide gene expression.

    Science.gov (United States)

    Sunkara, Lakshmi T; Achanta, Mallika; Schreiber, Nicole B; Bommineni, Yugendar R; Dai, Gan; Jiang, Weiyu; Lamont, Susan; Lillehoj, Hyun S; Beker, Ali; Teeter, Robert G; Zhang, Guolong

    2011-01-01

    Host defense peptides (HDPs) constitute a large group of natural broad-spectrum antimicrobials and an important first line of immunity in virtually all forms of life. Specific augmentation of synthesis of endogenous HDPs may represent a promising antibiotic-alternative approach to disease control. In this study, we tested the hypothesis that exogenous administration of butyrate, a major type of short-chain fatty acids derived from bacterial fermentation of undigested dietary fiber, is capable of inducing HDPs and enhancing disease resistance in chickens. We have found that butyrate is a potent inducer of several, but not all, chicken HDPs in HD11 macrophages as well as in primary monocytes, bone marrow cells, and jejuna and cecal explants. In addition, butyrate treatment enhanced the antibacterial activity of chicken monocytes against Salmonella enteritidis, with a minimum impact on inflammatory cytokine production, phagocytosis, and oxidative burst capacities of the cells. Furthermore, feed supplementation with 0.1% butyrate led to a significant increase in HDP gene expression in the intestinal tract of chickens. More importantly, such a feeding strategy resulted in a nearly 10-fold reduction in the bacterial titer in the cecum following experimental infections with S. enteritidis. Collectively, the results indicated that butyrate-induced synthesis of endogenous HDPs is a phylogenetically conserved mechanism of innate host defense shared by mammals and aves, and that dietary supplementation of butyrate has potential for further development as a convenient antibiotic-alternative strategy to enhance host innate immunity and disease resistance. PMID:22073293

  13. Feeding profiles of tame moose

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This report is on the feeding profiles of tame moose. 3 moose were observed for 99 hours while in natural range, each bite plant species, browse conditions and size...

  14. Infant feeding practices in Malaysia.

    Science.gov (United States)

    Chen, S T

    1978-12-01

    Retrospective nutritional data on 100 children, aged 6 months to 2 1/2 years, who were admitted to the University Hospital in Kuala Lumpur, Malaysia, was obtained by interviewing the mothers of the children. Analysis of the data revealed that 1) only 49% of the children were breast-fed as infants; 2) 50% of the mothers who did breast-feed discontinued breast-feeding before the children were 3 months old; and 3) the weaning diet of at least 1/3 of the children was inadequate. 18% of the children were Malays, 49% were Chinese, and 33% were Indian. The proportion of breast-fed children was highest among the Malays and lowest among the Chinese. Mothers with higher incomes tended to stop breast-feeding earlier than mothers with lower incomes. 67% of the women said they stopped breast-feeding due to inadequate lactation. Most of the children received supplementary foods at relatively early ages. 50% of the infants received starchy foods by the time they were 3 1/2 months old, and 50% received fruit or fruit juice by the time they were 3 1/2 months old. Vegetable products, meat, fish, and eggs were not added to the diet until the children were considerably older. Recommendations, based on the study findings, were 1) hospitals should discontinue the practice of deferring breast-feeding initiation for 24 hours after delivery; 2) mothers should be encouraged to breast-feed fully; and 3) health personnel should discourage the widespread use of costly precooked cereals for supplementary feeding. Tables depicted 1) the frequency distribution of the 100 children by income and by milk feeding patterns according to ethnic affiliation and 2) the cost of serving precooked cereals as compared to the cost of serving home cooked meals. PMID:755160

  15. Feeding Disorders in Williams Syndrome

    OpenAIRE

    S. M Greis

    2009-01-01

    Statement of Purpose: Children with Williams Syndrome are at risk for a myriad of developmental disabilities because of the complicated medical and neurological conditions. Little has been written about the specific types of feeding problems in these children. A better understanding of how this syndrome affects a child’s ability to manipulate increasingly complex food textures and advance oral motor function could provide improved outcomes for feeding and swallowing developme...

  16. Bacterial incorporation of tritiated thymidine and populations of bacteriophagous fauna in the rhizosphere of wheat

    DEFF Research Database (Denmark)

    Christensen, Henrik; Griffiths, Bryan; Christensen, Søren

    1992-01-01

    Bacterial and microfaunal populations, and bacterial productivity measured by tritiated thymidine (3HTdr) incorporation, in the rhizosphere of wheat seedlings were measured. Soil from planted pots was fractionated into rhizosphere and non-rhizosphere (bulk) soil, while unplanted soil was taken from...... pots without plants. Total bacterial counts and biovolume did not differ between fractions but viable (plate) counts were 8 times higher in the rhizosphere compared to bulk and unplanted soil. 3HTdr was incorporated at a constant rate with low variability in bulk or unplanted soil. In rhizosphere soil...... 3HTdr incorporation was lower than in bulk or unplanted soils and showed high variability. The populations of bacterial-feeding protozoa and nematodes indicated that rhizosphere bacterial activity was actually 3–4 times greater in rhizosphere than bulk soil in accordance with the results of the...

  17. Feed quality in swine diet

    Directory of Open Access Journals (Sweden)

    Živković Branislav

    2002-01-01

    Full Text Available The paper will demonstrate the quality of some feed used in swine diet. The emphasis will be on feed whose incorporation into mixes could result in unfavorable effects on production, health and economic production of swine. Data will be presented on maize and its possible negative effects, having in mind toxins. Soybean meal, or genetically modified soybean meal, will also be observed. The next feed which will be discussed will be soybean whey obtained by different procedures and the potential dangers of its use in swine diet rations. Sunflower meal, feed of animal origin, with emphasis on fish flour and meat-bone flour will also be covered in the work. A feed which has been attracting particular attention lately is yeast imported from Italy. Its quality characteristics will be discussed, the so-called non-protein nitrogen. Analyses of mineral feed will include sources of phosphorus, phosphates (monocalciumphosphate, dicalcium phosphate phytases and resolving the problem of phosphorus in swine rations. Finally, an inevitable segment are synthetic amino acids, especially lysine and its role in swine diet.

  18. Chronic bacterial infection models for BRM screening.

    Science.gov (United States)

    Dickneite, G; Schorlemmer, H U; Sedlacek, H H

    1984-05-01

    Models of chronic infections have been established to test the therapeutic and prophylactic potency of biological response modifiers (BRM). As an example for a BRM the immunostimulating drug Bestatin was tested. It is of dipeptide nature and was purified from culture supernatants of Streptomyces olivoreticuli. In two chronic bacterial infection models, induced by the inoculation of NRMI mice with Salmonella typhimurium or with a nephropathogenic strain of Escherichia coli, Bestatin acted prophylactically as well as therapeutically. This could be seen from the reduction of bacterial organ colonization and the inhibition of organ lesion formation. Bestatin could be shown to stimulate macrophage activity and to potentiate delayed type hypersensitivity, but not be effective on the humoral immune response. PMID:6383323

  19. Economic benefits of using prebiotic and probiotic products as supplements in stimulation feeds administered to bee colonies

    OpenAIRE

    PATRUICA, Silvia; HUTU, Ioan

    2013-01-01

    Spring stimulation feeding of honeybee colonies (Apis mellifera carpatica) is a very important technique for the encouragement of productive foraging. In addition to improving bee health by creating favorable conditions for the development of a beneficial intestinal bacterial flora, the use of prebiotic and probiotic supplements in the feed promotes good colony development, thus increasing the forager population. This paper presents the results for the economic benefit measured following use ...

  20. Experimental infection of plants with an herbivore-associated bacterial endosymbiont influences herbivore host selection behavior

    Science.gov (United States)

    Although bacterial endosymbioses are common among phloeophagous herbivores, little is known regarding the effects of symbionts on herbivore host selection and population dynamics. We tested the hypothesis that plant selection and reproductive performance by a phloem-feeding herbivore (potato psyllid...

  1. Invertebrate footprints on detritus processing, bacterial community structure, and spatiotemporal redox profiles

    OpenAIRE

    Hunting, E.R.; Whatley, M. H.; Geest, van der, A.H.M.; Mulder, C; Kraak, M.H.S.; Breure, A M; Admiraal, W.

    2012-01-01

    Detritus processing is driven by a complex interplay between macroinvertebrate and microbial activities. Bioturbation/feeding activities of invertebrates in sediments are known to influence decomposition rates. However, direct effects of invertebrates on bacterial communities and detritus processing remain ill-defined, mainly because identifying interactions between invertebrates and sediments is methodologically challenging. We incubated 5 macroinvertebrate species with various bioturbation/...

  2. Bacterial Degradation of Pesticides

    DEFF Research Database (Denmark)

    Knudsen, Berith Elkær

    This PhD project was carried out as part of the Microbial Remediation of Contaminated Soil and Water Resources (MIRESOWA) project, funded by the Danish Council for Strategic Research (grant number 2104-08-0012). The environment is contaminated with various xenobiotic compounds e.g. pesticides......D student, to construct fungal-bacterial consortia in order to potentially stimulate pesticide degradation thereby increasing the chance of successful bioaugmentation. The results of the project are reported in three article manuscripts, included in this thesis. In manuscript I, the mineralization of 2...

  3. Bacterial mitotic machineries

    DEFF Research Database (Denmark)

    Gerdes, Kenn; Møller-Jensen, Jakob; Ebersbach, Gitte; Kruse, Torben; Nordström, Kurt

    2004-01-01

    Here, we review recent progress that yields fundamental new insight into the molecular mechanisms behind plasmid and chromosome segregation in prokaryotic cells. In particular, we describe how prokaryotic actin homologs form mitotic machineries that segregate DNA before cell division. Thus, the P......M protein of plasmid R1 forms F actin-like filaments that separate and move plasmid DNA from mid-cell to the cell poles. Evidence from three different laboratories indicate that the morphogenetic MreB protein may be involved in segregation of the bacterial chromosome....

  4. Bacterial terpene cyclases.

    Science.gov (United States)

    Dickschat, Jeroen S

    2016-01-01

    Covering: up to 2015. This review summarises the accumulated knowledge about characterised bacterial terpene cyclases. The structures of identified products and of crystallised enzymes are included, and the obtained insights into enzyme mechanisms are discussed. After a summary of mono-, sesqui- and diterpene cyclases the special cases of the geosmin and 2-methylisoborneol synthases that are both particularly widespread in bacteria will be presented. A total number of 63 enzymes that have been characterised so far is presented, with 132 cited references. PMID:26563452

  5. Functional recovery of biofilm bacterial communities after copper exposure

    International Nuclear Information System (INIS)

    Potential of bacterial communities in biofilms to recover after copper exposure was investigated. Biofilms grown outdoor in shallow water on glass dishes were exposed in the laboratory to 0.6, 2.1, 6.8 μmol/l copper amended surface water and a reference and subsequently to un-amended surface water. Transitions of bacterial communities were characterised with denaturing gradient gel electrophoresis (DGGE) and community-level physiological profiles (CLPP). Exposure to 6.8 μmol/l copper provoked distinct changes in DGGE profiles of bacterial consortia, which did not reverse upon copper depuration. Exposure to 2.1 and 6.8 μmol/l copper was found to induce marked changes in CLPP of bacterial communities that proved to be reversible during copper depuration. Furthermore, copper exposure induced the development of copper-tolerance, which was partially lost during depuration. It is concluded that bacterial communities exposed to copper contaminated water for a period of 26 days are capable to restore their metabolic attributes after introduction of unpolluted water in aquaria for 28 days. - Genetically different bacterial communities can have similar functions and tolerance to copper

  6. Spacer geometry and particle deposition in spiral wound membrane feed channels

    KAUST Repository

    Radu, A.I.

    2014-11-01

    Deposition of microspheres mimicking bacterial cells was studied experimentally and with a numerical model in feed spacer membrane channels, as used in spiral wound nanofiltration (NF) and reverse osmosis (RO) membrane systems. In-situ microscopic observations in membrane fouling simulators revealed formation of specific particle deposition patterns for different diamond and ladder feed spacer orientations. A three-dimensional numerical model combining fluid flow with a Lagrangian approach for particle trajectory calculations could describe very well the in-situ observations on particle deposition in flow cells. Feed spacer geometry, positioning and cross-flow velocity sensitively influenced the particle transport and deposition patterns. The deposition patterns were not influenced by permeate production. This combined experimental-modeling approach could be used for feed spacer geometry optimization studies for reduced (bio)fouling. © 2014 Elsevier Ltd.

  7. Feed your head: neurodevelopmental control of feeding and metabolism.

    Science.gov (United States)

    Lee, Daniel A; Blackshaw, Seth

    2014-01-01

    During critical periods of development early in life, excessive or scarce nutritional environments can disrupt the development of central feeding and metabolic neural circuitry, leading to obesity and metabolic disorders in adulthood. A better understanding of the genetic networks that control the development of feeding and metabolic neural circuits, along with knowledge of how and where dietary signals disrupt this process, can serve as the basis for future therapies aimed at reversing the public health crisis that is now building as a result of the global obesity epidemic. This review of animal and human studies highlights recent insights into the molecular mechanisms that regulate the development of central feeding circuitries, the mechanisms by which gestational and early postnatal nutritional status affects this process, and approaches aimed at counteracting the deleterious effects of early over- and underfeeding. PMID:24274739

  8. Privatization of cooperative benefits stabilizes mutualistic cross-feeding interactions in spatially structured environments.

    Science.gov (United States)

    Pande, Samay; Kaftan, Filip; Lang, Stefan; Svatoš, Aleš; Germerodt, Sebastian; Kost, Christian

    2016-06-01

    Metabolic cross-feeding interactions are ubiquitous in natural microbial communities. However, it remains generally unclear whether the production and exchange of metabolites incurs fitness costs to the producing cells and if so, which ecological mechanisms can facilitate a cooperative exchange of metabolites among unrelated individuals. We hypothesized that positive assortment within structured environments can maintain mutualistic cross-feeding. To test this, we engineered Acinetobacter baylyi and Escherichia coli to reciprocally exchange essential amino acids. Interspecific coculture experiments confirmed that non-cooperating types were selectively favoured in spatially unstructured (liquid culture), yet disfavoured in spatially structured environments (agar plates). Both an individual-based model and experiments with engineered genotypes indicated that a segregation of cross-feeders and non-cooperating auxotrophs stabilized cooperative cross-feeding in spatially structured environments. Chemical imaging confirmed that auxotrophs were spatially excluded from cooperative benefits. Together, these results demonstrate that cooperative cross-feeding between different bacterial species is favoured in structured environments such as bacterial biofilms, suggesting this type of interactions might be common in natural bacterial communities. PMID:26623546

  9. Changes in activity of lysine decarboxylase in winter triticale in response to grain aphid feeding.

    Science.gov (United States)

    Sempruch, C; Leszczyński, B; Wójcicka, Agnieszka; Makosz, M; Matok, H; Chrzanowski, G

    2010-12-01

    Changes in lysine decarboxylase (LDC) activity caused by Sitobion avenae (F.) feeding on two winter triticale cultivars (cvs) were studied. The aphid fecundity and values of intrinsic rate of natural increase showed that cv Witon was less susceptible to S. avenae than cv Tornado. The grain aphid feeding on more susceptible triticale caused a decrease in the LDC activity, with exceptions of root tissues after two weeks of the feeding. In case of less susceptible cv Witon reduction of the LDC activity was observed only during initial period of S. avenae feeding. Later the aphid infestation induced activity of the LDC within tissues of cv Witon. PMID:21112841

  10. Feed or bioenergy production from agri-industrial residues?

    DEFF Research Database (Denmark)

    Tonini, Davide; Hamelin, Lorie; Astrup, Thomas Fruergaard

    consequences on the food/feed market, or on the carbon balance of the soil. The first are commonly called indirect land-use changes (iLUC), as they cause an increase in the international demand of a food/feed product, finally inducing an expansion of cropland into other ecosystems. Failing to account for these...... consequences may lead to misrepresent the actual environmental impacts. This study quantified, by use of consequential life cycle assessment (cLCA), the environmental impacts associated with a number of bioenergy scenarios involving selected agri-industrial residues. Three relevant conversion pathways were...

  11. Transport powered by bacterial turbulence

    OpenAIRE

    Kaiser, Andreas; Peshkov, Anton; Sokolov, Andrey; ten Hagen, Borge; Löwen, Hartmut; Aranson, Igor S.

    2014-01-01

    We demonstrate that collective turbulent-like motion in a bacterial bath can power and steer directed transport of mesoscopic carriers through the suspension. In our experiments and simulations, a microwedge-like "bulldozer" draws energy from a bacterial bath of varied density. We obtain that a maximal transport speed is achieved in the turbulent state of the bacterial suspension. This apparent rectification of random motion of bacteria is caused by polar ordered bacteria inside the cusp regi...

  12. Interaction of multiple biomimetic antimicrobial polymers with model bacterial membranes

    International Nuclear Information System (INIS)

    Using atomistic molecular dynamics simulations, interaction of multiple synthetic random copolymers based on methacrylates on prototypical bacterial membranes is investigated. The simulations show that the cationic polymers form a micellar aggregate in water phase and the aggregate, when interacting with the bacterial membrane, induces clustering of oppositely charged anionic lipid molecules to form clusters and enhances ordering of lipid chains. The model bacterial membrane, consequently, develops lateral inhomogeneity in membrane thickness profile compared to polymer-free system. The individual polymers in the aggregate are released into the bacterial membrane in a phased manner and the simulations suggest that the most probable location of the partitioned polymers is near the 1-palmitoyl-2-oleoyl-phosphatidylglycerol (POPG) clusters. The partitioned polymers preferentially adopt facially amphiphilic conformations at lipid-water interface, despite lacking intrinsic secondary structures such as α-helix or β-sheet found in naturally occurring antimicrobial peptides

  13. Interaction of multiple biomimetic antimicrobial polymers with model bacterial membranes

    Energy Technology Data Exchange (ETDEWEB)

    Baul, Upayan, E-mail: upayanb@imsc.res.in; Vemparala, Satyavani, E-mail: vani@imsc.res.in [The Institute of Mathematical Sciences, C.I.T. Campus, Taramani, Chennai 600113 (India); Kuroda, Kenichi, E-mail: kkuroda@umich.edu [Department of Biologic and Materials Sciences, University of Michigan School of Dentistry, Ann Arbor, Michigan 48109 (United States)

    2014-08-28

    Using atomistic molecular dynamics simulations, interaction of multiple synthetic random copolymers based on methacrylates on prototypical bacterial membranes is investigated. The simulations show that the cationic polymers form a micellar aggregate in water phase and the aggregate, when interacting with the bacterial membrane, induces clustering of oppositely charged anionic lipid molecules to form clusters and enhances ordering of lipid chains. The model bacterial membrane, consequently, develops lateral inhomogeneity in membrane thickness profile compared to polymer-free system. The individual polymers in the aggregate are released into the bacterial membrane in a phased manner and the simulations suggest that the most probable location of the partitioned polymers is near the 1-palmitoyl-2-oleoyl-phosphatidylglycerol (POPG) clusters. The partitioned polymers preferentially adopt facially amphiphilic conformations at lipid-water interface, despite lacking intrinsic secondary structures such as α-helix or β-sheet found in naturally occurring antimicrobial peptides.

  14. 7 CFR 205.237 - Livestock feed.

    Science.gov (United States)

    2010-01-01

    ...) The producer of an organic livestock operation must provide livestock with a total feed ration... § 205.603 may be used as feed additives and supplements. (b) The producer of an organic operation must... specific stage of life; (3) Feed plastic pellets for roughage; (4) Feed formulas containing urea or...

  15. Spontaneous bacterial peritonitis

    Institute of Scientific and Technical Information of China (English)

    Anastasios Koulaouzidis; Shivaram Bhat; Athar A Saeed

    2009-01-01

    Since its initial description in 1964, research has transformed spontaneous bacterial peritonitis (SBP) from a feared disease (with reported mortality of 90%) to a treatable complication of decompensated cirrhosis,albeit with steady prevalence and a high recurrence rate. Bacterial translocation, the key mechanism in the pathogenesis of SBP, is only possible because of the concurrent failure of defensive mechanisms in cirrhosis.Variants of SBP should be treated. Leucocyte esterase reagent strips have managed to shorten the 'tap-toshot' time, while future studies should look into their combined use with ascitic fluid pH. Third generation cephalosporins are the antibiotic of choice because they have a number of advantages. Renal dysfunction has been shown to be an independent predictor of mortality in patients with SBP. Albumin is felt to reduce the risk of renal impairment by improving effective intravascular volume, and by helping to bind proinflammatory molecules. Following a single episode of SBP, patients should have long-term antibiotic prophylaxis and be considered for liver transplantation.

  16. Adult bacterial meningitis

    DEFF Research Database (Denmark)

    Meyer, C N; Samuelsson, I S; Galle, M;

    2004-01-01

    Episodes of adult bacterial meningitis (ABM) at a Danish hospital in 1991-2000 were identified from the databases of the Department of Clinical Microbiology, and compared with data from the Danish National Patient Register and the Danish National Notification System. Reduced penicillin susceptibi......Episodes of adult bacterial meningitis (ABM) at a Danish hospital in 1991-2000 were identified from the databases of the Department of Clinical Microbiology, and compared with data from the Danish National Patient Register and the Danish National Notification System. Reduced penicillin...... susceptibility occurred in 21 (23%) of 92 cases of known aetiology, compared to an estimated 6% in nationally notified cases (p <0.001). Ceftriaxone plus penicillin as empirical treatment was appropriate in 97% of ABM cases in the study population, and in 99.6% of nationally notified cases. The notification rate...... was 75% for penicillin-susceptible episodes, and 24% for penicillin-non-susceptible episodes (p <0.001). Cases involving staphylococci, Pseudomonas spp. and Enterobacteriaceae were under-reported. Among 51 ABM cases with no identified risk factors, nine of 11 cases with penicillin...

  17. [Endogenous bacterial endophthalmitis].

    Science.gov (United States)

    Cornut, P-L; Chiquet, C

    2011-01-01

    Endogenous bacterial endophthalmitis, also called metastatic bacterial endophthalmitis, remains a diagnostic and therapeutic challenge. It is a rare and potentially sight-threatening ocular infection that occurs when bacteria reach the eye via the bloodstream, cross the blood-ocular barrier, and multiply within the eye. It usually affects immunocompromised patients and those suffering from diabetes mellitus, malignancy, or cardiac disease, but has also been reported after invasive procedures or in previously healthy people. In most cases, the ocular symptoms occur after the diagnosis of septicemia or systemic infection. Ocular symptoms include decreased vision, redness, discharge, pain, and floaters. The ocular inflammatory signs may be anterior and/or posterior. Bilateral involvement occurs in nearly 25% of cases. A wide range of microorganisms are involved, with differences in their frequency according to geography as well as the patient's age and past medical history, because of variations in the predisposing conditions and the source of the sepsis. The majority of patients are initially misdiagnosed, and ophthalmologists should be aware of this because prompt local and general management is required to save the eye and/or the patient's life. PMID:21145128

  18. Feeding the Monster

    Science.gov (United States)

    2005-10-01

    Near-infrared images of the active galaxy NGC 1097, obtained with the NACO adaptive optics instrument on ESO's Very Large Telescope, disclose with unprecedented detail a complex central network of filamentary structure spiralling down to the centre of the galaxy. These observations provide astronomers with new insights on how super-massive black holes lurking inside galaxies get fed. "This is possibly the first time that a detailed view of the channelling process of matter, from the main part of the galaxy down to the very end in the nucleus is released," says Almudena Prieto (Max-Planck Institute, Heidelberg, Germany), lead author of the paper describing these results. Located at a distance of about 45 million light-years in the southern constellation Fornax (the Furnace), NGC 1097 is a relatively bright, barred spiral galaxy seen face-on. At magnitude 9.5, and thus just 25 times fainter than the faintest object that can be seen with the unaided eye, it appears in small telescopes as a bright, circular disc. NGC 1097 is a very moderate example of an Active Galactic Nucleus (AGN), whose emission is thought to arise from matter (gas and stars) falling into oblivion in a central black hole. However, NGC 1097 possesses a comparatively faint nucleus only, and the black hole in its centre must be on a very strict "diet": only a small amount of gas and stars is apparently being swallowed by the black hole at any given moment. Astronomers have been trying to understand for a long time how the matter is "gulped" down towards the black hole. Watching directly the feeding process requires very high spatial resolution at the centre of galaxies. This can be achieved by means of interferometry as was done with the VLTI MIDI instrument on the central parts of another AGN, NGC 1068 (see ESO PR 17/03), or with adaptive optics [1]. Thus, astronomers [2] obtained images of NGC 1097 with the adaptive optics NACO instrument attached to Yepun, the fourth Unit Telescope of ESO's VLT

  19. Tube feeding patients with dementia.

    Science.gov (United States)

    Chernoff, Ronni

    2006-04-01

    As the population ages, the incidence of dementia increases. All types of dementia, whether they are reversible or irreversible, lead to loss of intellectual function and judgment, memory impairment, and personality changes. The skills to feed oneself, use eating utensils, and consume items recognized as food, thereby maintaining nutrition status, may be lost as dementia progresses. Reports indicate that nutrition status may be maintained when patients are hand fed, but this is labor intensive and therefore expensive. Feeding via a percutaneous endoscopic gastrostomy tube is often chosen as an acceptable alternative. Research indicates that there is little benefit in this population when aggressive nutrition support is instituted. Providing tube feeding to patients with dementia does not necessarily extend life, increase weight, or reduce the incidence of pressure ulcers or aspiration. There are many legal and ethical issues involved in the decision to place a feeding tube in demented patients. The primary issue in patients with dementia may be autonomy and the right of an individual to decide whether or not a tube should be placed at all. Legally, there is clear precedent that the courts see the insertion of a feeding tube as extraordinary care that the patient has the right to refuse. However, much of case law is derived from cases of patients who were in a persistent vegetative state. Advance directives help to determine what the patient would want for himself. Considering all the options before the patient can no longer make decisions is the most desirable course. PMID:16556924

  20. Microbial community profiles of the jejunum from steers differing in feed efficiency.

    Science.gov (United States)

    Myer, P R; Wells, J E; Smith, T P L; Kuehn, L A; Freetly, H C

    2016-01-01

    Research regarding the association between the microbial community and host feed efficiency in cattle has primarily focused on the rumen. However, the various microbial populations within the gastrointestinal tract as a whole are critical to the overall well-being of the host and need to be examined when determining the interplay between host and nonhost factors affecting feed efficiency. The objective of this study was to characterize the microbial communities of the jejunum among steers differing in feed efficiency. Within 2 contemporary groups of steers, individual ADFI and ADG were determined from animals fed the same diet. At the end of each feeding period, steers were ranked based on their standardized distance from the bivariate mean (ADG and ADFI). Four steers with the greatest deviation within each Cartesian quadrant were sampled ( = 16/group; 2 groups). Bacterial 16S rRNA gene amplicons were sequenced from the jejunum content using next-generation sequencing technology. The phylum Firmicutes accounted for up to 90% of the populations within all samples and was dominated by the families Clostridiaceae and Ruminococcaceae. UniFrac principal coordinate analyses did not indicate any separation of microbial communities within the jejunum based on feed efficiency phenotype, and no significant changes were indicated by bacterial diversity or richness metrics. The relative abundances of microbial populations and operational taxonomic units did reveal significant differences between feed efficiency groups ( < 0.05), including the phylum Proteobacteria ( = 0.030); the families Lachnospiraceae ( = 0.035), Coriobacteriaceae ( = 0.012), and Sphingomonadaceae ( = 0.035); and the genera ( = 0.019), ( = 0.018), and ( = 0.022). The study identified jejunal microbial associations with feed efficiency, ADG, and ADFI. This study suggests the association of the jejunum microbial community as a factor influencing feed efficiency at the 16S level. PMID:26812338

  1. Periodic growth of bacterial colonies

    Science.gov (United States)

    Yamazaki, Yoshihiro; Ikeda, Takemasa; Shimada, Hirotoshi; Hiramatsu, Fumiko; Kobayashi, Naoki; Wakita, Jun-ichi; Itoh, Hiroto; Kurosu, Sayuri; Nakatsuchi, Michio; Matsuyama, Tohey; Matsushita, Mitsugu

    2005-06-01

    The formation of concentric ring colonies by bacterial species Bacillus subtilis and Proteus mirabilis has been investigated experimentally, focusing our attention on the dependence of local cell density upon the bacterial motility. It has been confirmed that these concentric ring colonies reflect the periodic change of the bacterial motility between motile cell state and immotile cell state. We conclude that this periodic change is macroscopically determined neither by biological factors (i.e., biological clock) nor by chemical factors (chemotaxis as inhibitor). And our experimental results strongly suggest that the essential factor for the change of the bacterial motility during concentric ring formation is the local cell density.

  2. Rheumatoid arthritis and bacterial infections

    Directory of Open Access Journals (Sweden)

    N L Prokopjeva

    2008-01-01

    Full Text Available To study features of bacterial infections course in pts with rheumatoid arthritis (RA and changes of laboratory measures after focus of infection sanation. Material and methods. 46 pts with definite rheumatoid arthritis were examined at the time of comorbid infection (Cl detection and after infection focus sanation. Bacteriological test with evaluation of flora sensitivity to antibiotics by disco-diffusion method was performed at baseline and after the course of antibacterial therapy to assess its efficacy. Hemogram, serum fibrinogen, rheumatoid factor, circulating immune complexes (CIC, C-reactive protein levels were assessed. Serum interleukin (IL 1(3, IL6 and neopterin concentrations were examined by immune-enzyme assay in a part of pts. Typical clinical features of Cl were present in only 28 (60,9% pts. 13 (28,3% pts had fever, 12 (26,0% — leukocytosis, 15 (32,6% — changes of leucocyte populations. Some laboratory measures (thrombocytes, fibrinogen, CIC, neopterin levels significantly decreased (p<0,05 after infection focus sanation without correction of disease modifying therapy. Cl quite often develop as asymptomatic processes most often in pts with high activity and can induce disturbances promoting appearance of endothelial dysfunction, atherothrombosis and reduction of life duration. So timely detection and proper sanation of infection focuses should be performed in pts with RA

  3. Bioleaching of Arsenic-Rich Gold Concentrates by Bacterial Flora before and after Mutation

    OpenAIRE

    Xuehui Xie; Xuewu Yuan; Na Liu; Xiaoguang Chen; Awad Abdelgadir; Jianshe Liu

    2013-01-01

    In order to improve the bioleaching efficiency of arsenic-rich gold concentrates, a mixed bacterial flora had been developed, and the mutation breeding method was adopted to conduct the research. The original mixed bacterial flora had been enrichedin acid mine drainage of Dexing copper mine, Jiangxi Province, China. It was induced by UV (ultraviolet), ultrasonic, and microwave, and their combination mutation. The most efficient bacterial flora after mutation was collected for further bioleach...

  4. Feed intake and oxygen consumption in fish

    OpenAIRE

    Subramanian, S.

    2013-01-01

    In fish, the voluntary feed intake is influenced by dietary, environmental and/or physiological factors. It is well known that under hypoxia the concentration of oxygen in the water (DO) determines the feed intake of fish. However at non-limiting water DO levels (normoxia), several other mechanisms might play a role in feed intake regulation. Under hypoxia feed intake and oxygen consumption are interrelated. In this thesis we proposed the ‘oxystatic’ concept of feed intake regulat...

  5. Coplanar waveguide feeds for phased array antennas

    Science.gov (United States)

    Simons, Rainee N.; Lee, Richard Q.

    1992-08-01

    The design and performance of the following coplanar waveguide (CPW) microwave distribution networks for linear as well as circularly polarized microstrip patches and printed dipole arrays is presented: (1) CPW/microstrip line feed; (2) CPW/balanced stripline feed; (3) CPW/slotline feed; (4) grounded CPW (GCPW)/balanced coplanar stripline feed; and (5) CPW/slot coupled feed. Typical measured radiation patterns are presented, and their relative advantages and disadvantages are compared.

  6. A plant natriuretic peptide-like gene in the bacterial pathogen Xanthomonas axonopodis may induce hyper-hydration in the plant host: a hypothesis of molecular mimicry

    OpenAIRE

    Sayed Muhammed; Seoighe Cathal; Nembaware Victoria; Gehring Chris

    2004-01-01

    Abstract Background Plant natriuretic peptides (PNPs) are systemically mobile molecules that regulate homeostasis at nanomolar concentrations. PNPs are up-regulated under conditions of osmotic stress and PNP-dependent processes include changes in ion transport and increases of H2O uptake into protoplasts and whole tissue. Presentation of the hypothesis The bacterial citrus pathogen Xanthomonas axonopodis pv. Citri str. 306 contains a gene encoding a PNP-like protein. We hypothesise that this ...

  7. Mucosal SIV vaccines comprising inactivated virus particles and bacterial adjuvants induce CD8+T-regulatory cells that suppress SIV positive CD4+cell activation and prevent SIV infection in the macaque model.

    OpenAIRE

    Jean Marie eAndrieu; song echen; Chunhui eLAI; weizhong eguo; Wei eLu

    2014-01-01

    A new paradigm of mucosal vaccination against HIV infection has been investigated in the macaque model. A vaccine consisting of inactivated SIVmac239 particles together with a living bacterial adjuvant (either the Calmette & Guerin bacillus, lactobacillus plantarum or Lactobacillus rhamnosus) was administered to macaques via the vaginal or oral/intragastic route. In contrast to all established human and veterinary vaccines, these three vaccine regimens did not elicit SIV-specific antibodies n...

  8. Mucosal SIV Vaccines Comprising Inactivated Virus Particles and Bacterial Adjuvants Induce CD8+ T-Regulatory Cells that Suppress SIV-Positive CD4+ T-Cell Activation and Prevent SIV Infection in the Macaque Model

    OpenAIRE

    Andrieu, Jean-Marie; Chen, Song; Lai, Chunhui; Guo, Weizhong; Lu, Wei

    2014-01-01

    A new paradigm of mucosal vaccination against human immunodeficiency virus (HIV) infection has been investigated in the macaque model. A vaccine consisting of inactivated simian immunodeficiency virus (SIV)mac239 particles together with a living bacterial adjuvant (either the Calmette and Guerin bacillus, Lactobacillus plantarum or Lactobacillus rhamnosus) was administered to macaques via the vaginal or oral/intragastric route. In contrast to all established human and veterinary vaccines, the...

  9. Transcriptional responses of Brassica nigra to feeding by specialist insects of different feeding guilds

    Institute of Scientific and Technical Information of China (English)

    Colette Broekgaarden; Roeland E. Voorrips; Marcel Dicke; Ben Vosman

    2011-01-01

    Plants show phenotypic changes when challenged with herbivorous insects. The mechanisms underlying these changes include the activation of transcriptional responses, which are dependent on the attacking insect. Most transcriptomic studies on crucifer-insect interactions have focused on the model plant Arabidopsis thaliana, a species that faces low herbivore pressure in nature. Here, we study the transcriptional responses of plants from a wild black mustard (Brassica nigra) population to herbivores of different feeding guilds using an A. thaliana-bused whole-genome microarray that has previously been shown to be suitable for transcriptomic analyses in Brassica. Transcriptional responses of 5. nigra after infestation with either Pieris rapae caterpillars or Brevicoryne brassicae aphids are analyzed and compared. Additionally, the insect-induced expression changes of some individual genes are analyzed through quantitative real-time polymerase chain reaction. The results show that feeding by both insect species results in the accumulation of transcripts encoding proteins involved in the detoxification of reactive oxygen species, defensive proteins and glucosinolates and this is correlated with experimental evidence in the literature on such biochemical effects. Although genes encoding proteins involved in similar processes are regulated by both insects, there was little overlap in the induction or repression of individual genes. Furthermore, P. rapae and B. brassicae seem to affect different phytohormone signaling pathways. In conclusion, our results indicate that B. nigra activates several defense-related genes in response to P. rapae or B. brassicae feeding, but that the response is dependent on the attacking insect species.

  10. The anti-inflammatory effect of combined complement and CD14 inhibition is preserved during escalating bacterial load

    OpenAIRE

    2015-01-01

    Combined inhibition of complement and CD14 is known to attenuate bacterial-induced inflammation, but the dependency of the bacterial load on this effect is unknown. Thus, we investigated whether the effect of such combined inhibition on Escherichia coli- and Staphylococcus aureus-induced inflammation was preserved during increasing bacterial concentrations. Human whole blood was preincubated with anti-CD14, eculizumab (C5-inhibitor) or compstatin (C3-inhibitor), or combinations thereof. Then ...

  11. Prey perception in feeding-current feeding copepods

    DEFF Research Database (Denmark)

    Kiørboe, Thomas; Goncalves, Rodrigo J.; Florian Couespel, Damien;

    2016-01-01

    We reply to the comments of Paffenhöfer and Jiang () who argues that remote chemical prey perception is necessary for feeding-current feeding copepods to fulfill their nutritional requirements in a dilute ocean, that remote chemical prey detection may only be observed at very low prey concentrati......We reply to the comments of Paffenhöfer and Jiang () who argues that remote chemical prey perception is necessary for feeding-current feeding copepods to fulfill their nutritional requirements in a dilute ocean, that remote chemical prey detection may only be observed at very low prey...... concentrations, and that chemical prey perception is feasible if prey cells release dissolved organic material in short-lasting but intense bursts. We demonstrate that mechanoreception at a very short range is sufficient to sustain a living, even in a dilute ocean. Further, if chemoreception requires that prey...... and Centropages hamatus, offered a 45-μm sized dinoflagellate at very low concentration. The observed short prey detection distances, up to a few prey cell radii, are consistent with mechanoreception and we argue briefly that near-field mechanoreception is the most likely and common prey perception mechanism...

  12. Effect of different commercial feed spacers on biofouling of reverse osmosis membrane systems: A numerical study

    KAUST Repository

    Bucs, Szilard

    2014-06-01

    Feed spacers and hydrodynamics have been found relevant for the impact of biofouling on performance in reverse osmosis (RO) and nanofiltration (NF) membrane systems.The objectives of this study on biofouling development were to determine the impact of (i) linear flow velocity and bacterial cell load, (ii) biomass location and (iii) various feed spacer geometries as applied in practice as well as a modified geometry spacer.A three-dimensional mathematical model for biofouling of feed spacer channels including hydrodynamics, solute mass transport and biofilm formation was developed in COMSOL Multiphysics and MATLAB software.Results of this study indicate that the feed channel pressure drop increase caused by biofilm formation can be reduced by using thicker and/or modified feed spacer geometry and/or a lower flow rate in the feed channel. The increase of feed channel pressure drop by biomass accumulation is shown to be strongly influenced by the location of biomass. Results of numerical simulations are in satisfactory agreement with experimental data, indicating that this micro-scale mechanistic model is representative for practice. The developed model can help to understand better the biofouling process of spiral-wound RO and NF membrane systems and to develop strategies to reduce and control biofouling. © 2013 Elsevier B.V.

  13. Effect of packaging material on the quality of irradiated chicken feed

    International Nuclear Information System (INIS)

    Effects of packaging material on the quality of irradiated chicken feed. The study was carried out to determine the proper packaging materials to maintain the keeping quality of irradiated chicken feed. Four kinds of packaging materials, namely laminated woven plastic bag, polyethylene film of 0,085 mm thick, laminated cement paper, and plain cement paper were made into puches with size of 15 x 25 cm, filled with 0.5 kg chicken feed and then irradiated with doses of 0.5 and 10 kGy. Samples were kept in ambient temperatures and the examinations were carried out every 2 months from 0 to 6 months of storage on the chemical changes and microbial content. Parameters examined were moisture content, thiobarbituric acid (TBA) value, total microbial count, mould and yeast count, enterobacteraceae, coliformbacteria, and aerobic and anaerobic bacterial spores. The results showed that the four packaging material were able to protect the chicken feed from gaining or loosing moisture, but the TBA values of chicken feed in plain cement paper pouches were lower than those in the three other packaging materials. The four kinds of packaging materials used did not give any meaningful effect on the microbial content of chicken feed, and were able to protect the chicken feed from recontamination during storage. 8 refs

  14. [Small intestine bacterial overgrowth].

    Science.gov (United States)

    Leung Ki, E L; Roduit, J; Delarive, J; Guyot, J; Michetti, P; Dorta, G

    2010-01-27

    Small intestine bacterial overgrowth (SIBO) is a condition characterised by nutrient malabsorption and excessive bacteria in the small intestine. It typically presents with diarrhea, flatulence and a syndrome of malabsorption (steatorrhea, macrocytic anemia). However, it may be asymptomatic in the eldery. A high index of suspicion is necessary in order to differentiate SIBO from other similar presenting disorders such as coeliac disease, lactose intolerance or the irritable bowel syndrome. A search for predisposing factor is thus necessary. These factors may be anatomical (stenosis, blind loop), or functional (intestinal hypomotility, achlorydria). The hydrogen breath test is the most frequently used diagnostic test although it lacks standardisation. The treatment of SIBO consists of eliminating predisposing factors and broad-spectrum antibiotic therapy. PMID:20214190

  15. Studying bacterial multispecies biofilms

    DEFF Research Database (Denmark)

    Røder, Henriette Lyng; Sørensen, Søren Johannes; Burmølle, Mette

    2016-01-01

    The high prevalence and significance of multispecies biofilms have now been demonstrated in various bacterial habitats with medical, industrial, and ecological relevance. It is highly evident that several species of bacteria coexist and interact in biofilms, which highlights the need for evaluating...... the approaches used to study these complex communities. This review focuses on the establishment of multispecies biofilms in vitro, interspecies interactions in microhabitats, and how to select communities for evaluation. Studies have used different experimental approaches; here we evaluate the...... benefits and drawbacks of varying the degree of complexity. This review aims to facilitate multispecies biofilm research in order to expand the current limited knowledge on interspecies interactions. Recent technological advances have enabled total diversity analysis of highly complex and diverse microbial...

  16. Salmonella Radicidation of Dry Mixed Feeds and Feed Ingredients

    International Nuclear Information System (INIS)

    Feed components contaminated with salmonellae act as vehicles in the transmission of these bacteria to slaughter animals and hence to meat and poultry. Terminal decontamination of ingredients or mixed feed seems required because sanitary improvements in processing, bagging and storage do not always appear effective in considerably reducing salmonella contamination rates. Experiments were carried out to assay the decontamination effect of pelletization of mixed feed. Enumeration of enterobacteriaceae was used as the analytical criterion. It appeared that a temperature over 80°C generally led to five decimal reductions in enterobacteriaceae counts; however, also currently used lower temperatures may bring about two decimal reductions only. Following earlier experiments with fish meal, range finding tests on the decontamination of mixed feed with 60Co gamma rays were also performed. To achieve five decimal reductions in the counts of the most resistant enterobacteriaceae which were encountered about 0.5 Mrad was required; survival curves were generally not linear, so that overall effective dose had to be used as a parameter. Feeding experiments with rats, using 35% fish meal irradiated at 0.8 Mrad in the diet for two years, demonstrated that neither losses of nutritive value nor the occurrence of orally toxic factors is effected by such an irradiation treatment. It is recommended that pilot plant tests be carried out. In these tests an attempt should be made to combine improved sanitation and pelletizing with a terminal radiation treatment of the bagged material with the lowest dose required. Such tests should preferably be carried out in suitable areas of countries like Peru or Chile. A brief outline is given of the development work and training of scientific and technical staff that should be carried out during the installation of such a pilot plant. (author)

  17. Multitrophic interaction in the rhizosphere of maize: root feeding of Western corn rootworm larvae alters the microbial community composition.

    Directory of Open Access Journals (Sweden)

    Flavia Dematheis

    Full Text Available BACKGROUND: Larvae of the Western Corn Rootworm (WCR feeding on maize roots cause heavy economical losses in the US and in Europe. New or adapted pest management strategies urgently require a better understanding of the multitrophic interaction in the rhizosphere. This study aimed to investigate the effect of WCR root feeding on the microbial communities colonizing the maize rhizosphere. METHODOLOGY/PRINCIPAL FINDINGS: In a greenhouse experiment, maize lines KWS13, KWS14, KWS15 and MON88017 were grown in three different soil types in presence and in absence of WCR larvae. Bacterial and fungal community structures were analyzed by denaturing gradient gel electrophoresis (DGGE of the 16S rRNA gene and ITS fragments, PCR amplified from the total rhizosphere community DNA. DGGE bands with increased intensity were excised from the gel, cloned and sequenced in order to identify specific bacteria responding to WCR larval feeding. DGGE fingerprints showed that the soil type and the maize line influenced the fungal and bacterial communities inhabiting the maize rhizosphere. WCR larval feeding affected the rhiyosphere microbial populations in a soil type and maize line dependent manner. DGGE band sequencing revealed an increased abundance of Acinetobacter calcoaceticus in the rhizosphere of several maize lines in all soil types upon WCR larval feeding. CONCLUSION/SIGNIFICANCE: The effects of both rhizosphere and WCR larval feeding seemed to be stronger on bacterial communities than on fungi. Bacterial and fungal community shifts in response to larval feeding were most likely due to changes of root exudation patterns. The increased abundance of A. calcoaceticus suggested that phenolic compounds were released upon WCR wounding.

  18. Bacterial Selection from Shrimp Ponds for Degradation of Organic Matters

    Directory of Open Access Journals (Sweden)

    Powtongsook, S.

    2007-01-01

    Full Text Available Accumulation of ammonia, nitrite and hydrogen sulfide in a shrimp pond is generally caused by incomplete degradation of residual organic matters from overfeeding and from organic wastes released by shrimps. The phenomenon affects shrimp growth and survival rate. The objectives of this investigation were to screen for a bacterial strain able to digest organic residues and to evaluate the changes of residues by bacterial activities under natural conditions. The results from this work showed that the isolated strain, Bacillus cereus S1, had the highest protease activity (57.1 U/ml with the presence of glucoamylase and lipase activities (4.5 and 0.13 U/ml, respectively. Under an aseptic condition in 1-L flasks containing seawater with 0.1% shrimp feed, B. cereus S1 degraded organic matters and significantly reduced chemical oxygen demand (COD (70.8%. An amount of ammonia-nitrogen was increased during the first 5 days of incubation due to the degradation of organic compounds in shrimp feed. However, it declined afterward with nitrate-nitrogen increase and unchanged nitrite nitrogen content. Under natural conditions in 10-L glass jars containing seawater with 0.05% shrimp feed and 0.05% sediment, B. cereus S1 and a commercial bacterial product (Inpicin-G could reduce COD (4.5% and 15.8%, respectively and biochemical oxygen demand (BOD (35.1 and 11.4%, respectively. However, similar changes of ammonia-nitrogen, nitrate-nitrogen and nitrite-nitrogen contents in water samples were observed. The results indicate that this selected bacterium could reduce organic compound accumulations on a laboratory scale. In addition, the strain did not produce any enterotoxins compared to a toxin standard. Therefore, the bacterium, Bacillus cereus S1, could be applied to decrease organic matters accumulated in shrimp pond without any harm to shrimps or consumers.

  19. Molecular approaches for bacterial azoreductases

    Directory of Open Access Journals (Sweden)

    Montira Leelakriangsak

    2013-12-01

    Full Text Available Azo dyes are the dominant types of synthetic dyes, widely used in textiles, foods, leather, printing, tattooing, cosmetics, and pharmaceutical industries. Many microorganisms are able to decolorize azo dyes, and there is increasing interest in biological waste treatment methods. Bacterial azoreductases can cleave azo linkages (-N=N- in azo dyes, forming aromatic amines. This review mainly focuses on employing molecular approaches, including gene manipulation and recombinant strains, to study bacterial azoreductases. The construction of the recombinant protein by cloning and the overexpression of azoreductase is described. The mechanisms and function of bacterial azoreductases can be studied by other molecular techniques discussed in this review, such as RT-PCR, southern blot analysis, western blot analysis, zymography, and muta-genesis in order to understand bacterial azoreductase properties, function and application. In addition, understanding the regulation of azoreductase gene expression will lead to the systematic use of gene manipulation in bacterial strains for new strategies in future waste remediation technologies.

  20. Feeding Currents Generated by Upside Down Jellyfish

    CERN Document Server

    Rodriguez, Terry; Gyoerkoe, Megan; Miller, Laura

    2010-01-01

    We present fluid dynamics videos of the pulsing dynamics and the resulting fluid flow generated by the upside down jellyfish, Cassiopea spp. Medusae of this genus are unusual in that they typically rest upside down on the ocean floor and pulse their bells to generate feeding currents, only swimming when significantly disturbed. The pulsing kinematics and fluid flow around these upside down jellyfish is investigated using a combination of videography, flow visualization, and numerical simulation. Significant mixing occurs around and directly above the oral arms and secondary mouths. Numerical simulations using the immersed boundary method with a porous layer representing the oral arms agree with the experimental results. The simulations also suggest that the presence of porous oral arms induce net horizontal flow towards the bell. Coherent vortex rings are not seen in the wake above the jellyfish, but starting and stopping vortices are observed before breaking up as they pass through the elaborate oral arms (i...