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Sample records for gram level synthesis

  1. A sustainable process for gram-scale synthesis of stereoselective ...

    Indian Academy of Sciences (India)

    RAJAN ABRAHAM

    2018-02-07

    Feb 7, 2018 ... for the additional structure modification.17–20. Acrylic acid derivatives ... mild conditions, and application in synthesizing bio- logically ... cal process for the gram-scale synthesis of streoselective ... ate yield of desired product 2 (58%, Table 1, entry. 2). .... Cross-Coupling and Atom-Economic Addition Reac-.

  2. Novel Antimicrobial Peptides That Inhibit Gram Positive Bacterial Exotoxin Synthesis

    Science.gov (United States)

    Merriman, Joseph A.; Nemeth, Kimberly A.; Schlievert, Patrick M.

    2014-01-01

    Gram-positive bacteria, such as Staphylococcus aureus, cause serious human illnesses through combinations of surface virulence factors and secretion of exotoxins. Our prior studies using the protein synthesis inhibitor clindamycin and signal transduction inhibitors glycerol monolaurate and α-globin and β-globin chains of hemoglobin indicate that their abilities to inhibit exotoxin production by S. aureus are separable from abilities to inhibit growth of the organism. Additionally, our previous studies suggest that inhibition of exotoxin production, in absence of ability to kill S. aureus and normal flora lactobacilli, will prevent colonization by pathogenic S. aureus, while not interfering with lactobacilli colonization. These disparate activities may be important in development of novel anti-infective agents that do not alter normal flora. We initiated studies to explore the exotoxin-synthesis-inhibition activity of hemoglobin peptides further to develop potential agents to prevent S. aureus infections. We tested synthesized α-globin chain peptides, synthetic variants of α-globin chain peptides, and two human defensins for ability to inhibit exotoxin production without significantly inhibiting S. aureus growth. All of these peptides were weakly or not inhibitory to bacterial growth. However, the peptides were inhibitory to exotoxin production with increasing activity dependent on increasing numbers of positively-charged amino acids. Additionally, the peptides could be immobilized on agarose beads or have amino acid sequences scrambled and still retain exotoxin-synthesis-inhibition. The peptides are not toxic to human vaginal epithelial cells and do not inhibit growth of normal flora L. crispatus. These peptides may interfere with plasma membrane signal transduction in S. aureus due to their positive charges. PMID:24748386

  3. Procalcitonin levels in gram-positive, gram-negative, and fungal bloodstream infections.

    Science.gov (United States)

    Leli, Christian; Ferranti, Marta; Moretti, Amedeo; Al Dhahab, Zainab Salim; Cenci, Elio; Mencacci, Antonella

    2015-01-01

    Procalcitonin (PCT) can discriminate bacterial from viral systemic infections and true bacteremia from contaminated blood cultures. The aim of this study was to evaluate PCT diagnostic accuracy in discriminating Gram-positive, Gram-negative, and fungal bloodstream infections. A total of 1,949 samples from patients with suspected bloodstream infections were included in the study. Median PCT value in Gram-negative (13.8 ng/mL, interquartile range (IQR) 3.4-44.1) bacteremias was significantly higher than in Gram-positive (2.1 ng/mL, IQR 0.6-7.6) or fungal (0.5 ng/mL, IQR 0.4-1) infections (P Gram-negatives from Gram-positives at the best cut-off value of 10.8 ng/mL and an AUC of 0.944 (95% CI 0.919-0.969, P Gram-negatives from fungi at the best cut-off of 1.6 ng/mL. Additional results showed a significant difference in median PCT values between Enterobacteriaceae and nonfermentative Gram-negative bacteria (17.1 ng/mL, IQR 5.9-48.5 versus 3.5 ng/mL, IQR 0.8-21.5; P Gram-negative from Gram-positive and fungal bloodstream infections. Nevertheless, its utility to predict different microorganisms needs to be assessed in further studies.

  4. Procalcitonin Levels in Gram-Positive, Gram-Negative, and Fungal Bloodstream Infections

    Directory of Open Access Journals (Sweden)

    Christian Leli

    2015-01-01

    Full Text Available Procalcitonin (PCT can discriminate bacterial from viral systemic infections and true bacteremia from contaminated blood cultures. The aim of this study was to evaluate PCT diagnostic accuracy in discriminating Gram-positive, Gram-negative, and fungal bloodstream infections. A total of 1,949 samples from patients with suspected bloodstream infections were included in the study. Median PCT value in Gram-negative (13.8 ng/mL, interquartile range (IQR 3.4–44.1 bacteremias was significantly higher than in Gram-positive (2.1 ng/mL, IQR 0.6–7.6 or fungal (0.5 ng/mL, IQR 0.4–1 infections (P<0.0001. Receiver operating characteristic analysis showed an area under the curve (AUC for PCT of 0.765 (95% CI 0.725–0.805, P<0.0001 in discriminating Gram-negatives from Gram-positives at the best cut-off value of 10.8 ng/mL and an AUC of 0.944 (95% CI 0.919–0.969, P<0.0001 in discriminating Gram-negatives from fungi at the best cut-off of 1.6 ng/mL. Additional results showed a significant difference in median PCT values between Enterobacteriaceae and nonfermentative Gram-negative bacteria (17.1 ng/mL, IQR 5.9–48.5 versus 3.5 ng/mL, IQR 0.8–21.5; P<0.0001. This study suggests that PCT may be of value to distinguish Gram-negative from Gram-positive and fungal bloodstream infections. Nevertheless, its utility to predict different microorganisms needs to be assessed in further studies.

  5. A sustainable process for gram-scale synthesis of stereoselective ...

    Indian Academy of Sciences (India)

    We have developed a new, simple and sustainable process for stereoselective synthesis of aryl substituted (E)-2-thiocyanatoacrylic acids by nucleophilic substitution and Knoevenagel condensation involving chloroacetic acid, ammonium thiocyanate and aromatic aldehydes at room temperature. The selectivity was ...

  6. High-level fluorescence labeling of gram-positive pathogens.

    Directory of Open Access Journals (Sweden)

    Simone Aymanns

    Full Text Available Fluorescence labeling of bacterial pathogens has a broad range of interesting applications including the observation of living bacteria within host cells. We constructed a novel vector based on the E. coli streptococcal shuttle plasmid pAT28 that can propagate in numerous bacterial species from different genera. The plasmid harbors a promoterless copy of the green fluorescent variant gene egfp under the control of the CAMP-factor gene (cfb promoter of Streptococcus agalactiae and was designated pBSU101. Upon transfer of the plasmid into streptococci, the bacteria show a distinct and easily detectable fluorescence using a standard fluorescence microscope and quantification by FACS-analysis demonstrated values that were 10-50 times increased over the respective controls. To assess the suitability of the construct for high efficiency fluorescence labeling in different gram-positive pathogens, numerous species were transformed. We successfully labeled Streptococcus pyogenes, Streptococcus agalactiae, Streptococcus dysgalactiae subsp. equisimilis, Enterococcus faecalis, Enterococcus faecium, Streptococcus mutans, Streptococcus anginosus and Staphylococcus aureus strains utilizing the EGFP reporter plasmid pBSU101. In all of these species the presence of the cfb promoter construct resulted in high-level EGFP expression that could be further increased by growing the streptococcal and enterococcal cultures under high oxygen conditions through continuous aeration.

  7. TSTA loop operation with 100 grams-level of tritium

    International Nuclear Information System (INIS)

    Yoshida, Hiroshi; Hirata, Shingo; Naito, Taisei

    1988-10-01

    The first loop operation tests of Tritium Systems Test Assembly (TSTA) with 100 grams-level of tritium were carried out at Los Alamos National Laboratory(LANL) on June and July, 1987. The tests were one of the milestones for TSTA goal scheduled in June, 1987 through June, 1988. The objectives were (i) to operate TSTA process loop composed of tritium supply system, fuel gas purification system, hydrogen isotope separation system, etc, (ii) to demonstrate TSTA safety subsystems such as secondary containment system, tritium waste treatment system and tritium monitoring system, and (iii) to accumulate handling experience of a large amount of tritium. This report describes the plan and procedures of the milestone run done in June and the summary results especially on the safety aspects. Analysis of the emergency shutdown of the process loop, which happened in the June run, is also reported. A brief description of the process and safety subsystems as well as the summary of the TSTA safety analysis report is included. (author)

  8. Blue green alga mediated synthesis of gold nanoparticles and its antibacterial efficacy against Gram positive organisms

    Energy Technology Data Exchange (ETDEWEB)

    Uma Suganya, K.S. [Centre for Ocean Research, Sathyabama University, Chennai 600 119 (India); Govindaraju, K., E-mail: govindtu@gmail.com [Centre for Ocean Research, Sathyabama University, Chennai 600 119 (India); Ganesh Kumar, V.; Stalin Dhas, T.; Karthick, V. [Centre for Ocean Research, Sathyabama University, Chennai 600 119 (India); Singaravelu, G. [Nanoscience Division, Department of Zoology, Thiruvalluvar University, Vellore 632115 (India); Elanchezhiyan, M. [Department of Microbiology, Dr ALM Post Graduate Institute of Basic Medical Sciences, University of Madras, Chennai 600113 (India)

    2015-02-01

    Biofunctionalized gold nanoparticles (AuNPs) play an important role in design and development of nanomedicine. Synthesis of AuNPs from biogenic materials is environmentally benign and possesses high bacterial inhibition and bactericidal properties. In the present study, blue green alga Spirulina platensis protein mediated synthesis of AuNPs and its antibacterial activity against Gram positive bacteria is discussed. AuNPs were characterized using Ultraviolet–visible (UV–vis) spectroscopy, Fluorescence spectroscopy, Fourier Transform-Infrared (FTIR) spectroscopy, Raman spectroscopy, High Resolution-Transmission Electron Microscopy (HR-TEM) and Energy Dispersive X-ray analysis (EDAX). Stable, well defined AuNPs of smaller and uniform shape with an average size of ∼ 5 nm were obtained. The antibacterial efficacy of protein functionalized AuNPs were tested against Gram positive organisms Bacillus subtilis and Staphylococcus aureus. - Highlights: • Size controlled synthesis of gold nanoparticles from blue green alga Spirulina platensis • Stability of gold nanoparticles at different temperatures • Potent antibacterial efficacy against Gram positive organisms.

  9. TSTA loop operation with 100 grams-level of tritium

    International Nuclear Information System (INIS)

    Yoshida, Hiroshi; Fukui, Hiroshi; Hirata, Shingo

    1988-12-01

    A fully integrated loop operation test of Tritium systems Test Assembly (TSTA) with 107 grams of tritium was completed at Los Alamos National Laboratory (LANL) in June, 1988. In this test, a compound cryopump with a charcoal panel was incorporated into the main process loop for the first time. The objectives were (i) to demonstrate the compound cryopump system with different flow rates and impurities, (ii) to demonstrate the regeneration of the compound cryopump system, (iii) to accumulate operating experience with other process systems such as the fuel cleanup system, the isotope separation system, the tritium supply and recovery system, etc. and (iv) to improve the data-base on TSTA safety systems such as the secondary containment system, tritium waste treatment system and tritium monitoring system. This report briefly describes characteristics of the main subsystems observed during the milestone run. (author)

  10. Cuprous Oxide Scale up: Gram Production via Bulk Synthesis using Classic Solvents at Low Temperatures

    Energy Technology Data Exchange (ETDEWEB)

    Hall, A. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Han, T. Y. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2015-05-07

    Cuprous oxide is a p-type semiconducting material that has been highly researched for its interesting properties. Many small-scale syntheses have exhibited excellent control over size and morphology. As the demand for cuprous oxide grows, the synthesis method need to evolve to facilitate large-scale production. This paper supplies a facile bulk synthesis method for Cu₂O on average, 1-liter reaction volume can produce 1 gram of particles. In order to study the shape and size control mechanisms on such a scale, the reaction volume was diminished to 250 mL producing on average 0.3 grams of nanoparticles per batch. Well-shaped nanoparticles have been synthesized using an aqueous solution of CuCl₂, NaOH, SDS surfactant, and NH₂OH-HCl at mild temperatures. The time allotted between the addition of NaOH and NH₂OH-HCl was determined to be critical for Cu(OH)2 production, an important precursor to the final produce The effects of stirring rates on a large scale was also analyzed during reagent addition and post reagent addition. A morphological change from rhombic dodecahedra to spheres occurred as the stirring speed was increased. The effects of NH₂OH-HCl concentration were also studied to control the etching effects of the final product.

  11. Measuring the Level of Agreement Between Cloacal Gram's Stains and Bacterial Cultures in Hispaniolan Amazon Parrots ( Amazona ventralis ).

    Science.gov (United States)

    Evans, Erika E; Mitchell, Mark A; Whittington, Julia K; Roy, Alma; Tully, Thomas N

    2014-12-01

    Cloacal or fecal Gram's stains and bacterial cultures are routinely performed during avian physical examinations to assess the microbial flora of the gastrointestinal tract. Although cloacal or fecal Gram's stains and bacterial cultures are considered routine diagnostic procedures, the level of agreement between the individual tests has not been determined. To investigate the level of agreement between results from Gram's stain and bacterial culture when used to assess cloacal or fecal samples from psittacine birds, samples were taken from 21 clinically healthy Hispaniolan Amazon parrots ( Amazona ventralis ) and tested by Gram's stain cytology and bacterial culture. Most bacteria (97.2%) identified by Gram's stain were gram positive. However, gram-negative organisms were identified in 7 of 21 (33.3%; 95% confidence interval: 13.3%-53.3%) birds. Escherichia coli was the only gram-negative organism identified on culture. Agreement between results of Gram's stain and culture was fair (weighted κ = 0.27). The results of this study suggest that Gram's stains and bacterial culture may need to be performed with a parallel testing strategy to limit the likelihood of misclassifying the microbial flora of psittacine patients.

  12. RPython high-level synthesis

    Science.gov (United States)

    Cieszewski, Radoslaw; Linczuk, Maciej

    2016-09-01

    The development of FPGA technology and the increasing complexity of applications in recent decades have forced compilers to move to higher abstraction levels. Compilers interprets an algorithmic description of a desired behavior written in High-Level Languages (HLLs) and translate it to Hardware Description Languages (HDLs). This paper presents a RPython based High-Level synthesis (HLS) compiler. The compiler get the configuration parameters and map RPython program to VHDL. Then, VHDL code can be used to program FPGA chips. In comparison of other technologies usage, FPGAs have the potential to achieve far greater performance than software as a result of omitting the fetch-decode-execute operations of General Purpose Processors (GPUs), and introduce more parallel computation. This can be exploited by utilizing many resources at the same time. Creating parallel algorithms computed with FPGAs in pure HDL is difficult and time consuming. Implementation time can be greatly reduced with High-Level Synthesis compiler. This article describes design methodologies and tools, implementation and first results of created VHDL backend for RPython compiler.

  13. Gram-scale synthesis of the p38α MAPK-inhibitor VX-745 for preclinical studies into Werner syndrome.

    Science.gov (United States)

    Bagley, Mark C; Davis, Terence; Dix, Matthew C; Fusillo, Vincenzo; Pigeaux, Morgane; Rokicki, Michal J; Kipling, David

    2010-09-01

    The ATP-competitive p38α MAPK inhibitor VX-745 exhibits an exquisite kinase selectivity profile, is effective in blocking p38 stress signaling in Werner syndrome dermal fibroblasts, has efficacy in clinical trials and may have therapeutic value against Werner syndrome. Previous synthetic routes, however, have only resulted in milligram quantities suitable for cell-based studies, whereas gram quantities would be required for in vivo use. Microwave irradiation using a stop-flow monomodal microwave reactor has been found to facilitate scale-up of the synthesis of VX-745. Ullmann-type C-S bond formation using thiophenol, chloropyridazine, copper(I) catalyst and diol ligand proceeds rapidly and efficiently in this apparatus for elaboration to the pyrimido[1,6-b]pyridazinone core of VX-745 on gram scale and with good overall yield. This method delivers the p38 inhibitor VX-745 in sufficient quantities for preclinical studies to rescue the aging phenotype in Werner syndrome.

  14. The Role of Monitoring Gentamicin Levels in Patients with Gram-Negative Peritoneal Dialysis-Associated Peritonitis

    Science.gov (United States)

    Tang, Wen; Cho, Yeoungjee; Hawley, Carmel M.; Badve, Sunil V.; Johnson, David W.

    2014-01-01

    ♦ Background: There is limited available evidence regarding the role of monitoring serum gentamicin concentrations in peritoneal dialysis (PD) patients receiving this antimicrobial agent in gram-negative PD-associated peritonitis. ♦ Methods: Using data collected in all patients receiving PD at a single center who experienced a gram-negative peritonitis episode between 1 January 2005 and 31 December 2011, we investigated the relationship between measured serum gentamicin levels on day 2 following initial empiric antibiotic therapy and subsequent clinical outcomes of confirmed gram-negative peritonitis. ♦ Results: Serum gentamicin levels were performed on day 2 in 51 (77%) of 66 first gram-negative peritonitis episodes. Average serum gentamicin levels on day 2 were 1.83 ± 0.84 mg/L with levels exceeding 2 mg/L in 22 (43%) cases. The overall cure rate was 64%. No cases of ototoxicity were observed. Day-2 gentamicin levels were not significantly different between patients who did and did not have a complication or cure. Using multivariable logistic regression analysis, failure to cure peritonitis was not associated with either day-2 gentamicin level (adjusted odds ratio (OR) 0.96, 95% confidence interval (CI) 0.25 - 3.73) or continuation of gentamicin therapy beyond day 2 (OR 0.28, 0.02 - 3.56). The only exception was polymicrobial peritonitis, where day-2 gentamicin levels were significantly higher in episodes that were cured (2.06 ± 0.41 vs 1.29 ± 0.71, p = 0.01). In 17 (26%) patients receiving extended gentamicin therapy, day-5 gentamicin levels were not significantly related to peritonitis cure. ♦ Conclusion: Day-2 gentamicin levels did not predict gentamicin-related harm or efficacy during short-course gentamicin therapy for gram-negative PD-related peritonitis, except in cases of polymicrobial peritonitis, where higher levels were associated with cure. PMID:24385334

  15. Gram staining.

    Science.gov (United States)

    Coico, Richard

    2005-10-01

    Named after Hans Christian Gram who developed the method in 1884, the Gram stain allows one to distinguish between Gram-positive and Gram-negative bacteria on the basis of differential staining with a crystal violet-iodine complex and a safranin counterstain. The cell walls of Gram-positive organisms retain this complex after treatment with alcohol and appear purple, whereas gram-negative organisms decolorize following such treatment and appear pink. The method described here is useful for assessing bacterial contamination of tissue culture samples or for examining the Gram stain status and morphological features of bacteria isolated from mixed or isolated bacterial cultures.

  16. Antibacterial Activity of Silver-Graphene Quantum Dots Nanocomposites Against Gram-Positive and Gram-Negative Bacteria

    Science.gov (United States)

    Habiba, Khaled (Inventor); Makarov, Vladimir (Inventor); Weiner, Brad R (Inventor); Morell, Gerardo (Inventor)

    2018-01-01

    The invention provides a composite of silver nanoparticles decorated with graphene quantum dots (Ag-GQDs) using pulsed laser synthesis. The nanocomposites were functionalized with polyethylene glycol (PEG). A concentration of 150 .mu.g/mL of Ag-GQDs, a non-toxic level for human cells, exhibits strong antibacterial activity against both Gram-Positive and Gram-Negative Bacteria.

  17. Expression levels of matrix metalloproteinase-9 and gram-negative bacteria in symptomatic and asymptomatic periapical lesions.

    Science.gov (United States)

    Ahmed, Geraldine M; El-Baz, Alaa A; Hashem, Ahmed Abdel Rahman; Shalaan, Abeer K

    2013-04-01

    The aim of this study was to test the hypothesis that the expression of matrix metalloproteinase (MMP)-9 is significantly elevated in patients with symptomatic apical periodontitis and to correlate this with the detected amount of gram-negative bacteria. Twenty-six patients with periapical lesions involving at least 2 teeth were included in this study. The patients were divided into 2 groups: the symptomatic (SYM) group included 13 patients expressing pain with periapical lesions, and the asymptomatic (ASYM) group included 13 patients expressing no pain. Root canal treatment was performed followed by endodontic surgery and periapical lesion collection. Periapical lesions were serially cut into 4-μ sections. Some sections were processed for histologic examination using hematoxylin-eosin stain. Other sections were processed for immunohistochemical examination. For MMP-9, the area fraction of the positive cells was measured, and the percentage of the MMP-9-immunopositive area to the total area of the microscopic field was calculated. For gram-negative stain cells, the number of cells showing the pink-red color was counted per microscopic field. The Student's t test was used to compare the SYM and ASYM groups. The Pearson correlation coefficient was used to determine a significant correlation between the number of cells and the MMP-9 level. The significance level was set at P ≤ .05. The SYM group showed a statistically significantly higher mean number of gram-negative cells (P = .001) and MMP-9 area percent (P < .001) than the ASYM group. There was a statistically significant positive (r = .927) correlation between the number of gram-negative cells and the MMP-9 area percent (P< .001). There is good evidence to suspect a significant role of gram-negative bacteria and MMP-9 in symptomatic periapical lesions. Copyright © 2013 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

  18. Controlled Synthesis of Gold Nanoparticles Using Aspergillus terreus IF0 and Its Antibacterial Potential against Gram Negative Pathogenic Bacteria

    International Nuclear Information System (INIS)

    Priyadarshini, E.; Pradhan, N.; Sukla, L.B.; Panda, P.K.; Pradhan, N.

    2014-01-01

    Biosynthesis of monodispersed nanoparticles, along with determination of potential responsible biomolecules, is the major bottleneck in the area of bio nano technology research. The present study focuses on an eco friendly, ambient temperature protocol for size controlled synthesis of gold nanoparticles, using the fungus Aspergillus terreus IF0. Gold nanoparticles were formed immediately, with the addition of chloroauric acid to the aqueous fungal extract. Synthesized nanoparticles were characterized by UV-Vis spectroscopy, TEM-EDX, and XRD analysis. Particle diameter and dispersity of nanoparticles were controlled by varying the ph of the fungal extract. At ph 10, the average size of the synthesized particles was in the range of 10–19 nm. Dialysis to obtain high and low molecular weight fraction followed by FTIR analysis revealed that biomolecules larger than 12 kDa and having –CH, –NH, and –SH functional groups were responsible for bioreduction and stabilization. In addition, the synthesized gold nanoparticles were found to be selectively bactericidal against the pathogenic gram negative bacteria, Escherichia coli.

  19. Design, Synthesis and Evaluation of Branched RRWQWR-Based Peptides as Antibacterial Agents Against Clinically Relevant Gram-Positive and Gram-Negative Pathogens

    Directory of Open Access Journals (Sweden)

    Sandra C. Vega

    2018-03-01

    Full Text Available Multidrug resistance of pathogenic bacteria has become a public health crisis that requires the urgent design of new antibacterial drugs such as antimicrobial peptides (AMPs. Seeking to obtain new, lactoferricin B (LfcinB-based synthetic peptides as viable early-stage candidates for future development as AMPs against clinically relevant bacteria, we designed, synthesized and screened three new cationic peptides derived from bovine LfcinB. These peptides contain at least one RRWQWR motif and differ by the copy number (monomeric, dimeric or tetrameric and structure (linear or branched of this motif. They comprise a linear palindromic peptide (RWQWRWQWR, a dimeric peptide (RRWQWR2KAhx and a tetrameric peptide (RRWQWR4K2Ahx2C2. They were screened for antibacterial activity against Enterococcus faecalis (ATCC 29212 and ATCC 51575 strains, Pseudomonas aeruginosa (ATCC 10145 and ATCC 27853 strains and clinical isolates of two Gram-positive bacteria (Enterococcus faecium and Staphylococcus aureus and two Gram-negative bacteria (Klebsiella pneumoniae and Pseudomonas aeruginosa. All three peptides exhibited greater activity than did the reference peptide, LfcinB (17–31, which contains a single linear RRWQWR motif. Against the ATCC reference strains, the three new peptides exhibited minimum inhibitory concentration (MIC50 values of 3.1–198.0 μM and minimum bactericidal concentration (MBC values of 25–200 μM, and against the clinical isolates, MIC50 values of 1.6–75.0 μM and MBC values of 12.5–100 μM. However, the tetrameric peptide was also found to be strongly hemolytic (49.1% at 100 μM. Scanning Electron Microscopy (SEM demonstrated that in the dimeric and tetrameric peptides, the RRWQWR motif is exposed to the pathogen surface. Our results may inform the design of new, RRWQWR-based AMPs.

  20. Determination of thorium and uranium at the nanogram per gram level in semiconductor potting plastics by neutron activation analysis

    International Nuclear Information System (INIS)

    Dyer, F.F.; Emery, J.F.; Bate, L.C.

    1985-01-01

    A method was developed to determine thorium and uranium in semiconductor potting plastics. The method is based on neutron activation and subsequent radiochemical separation to isolate and permit measurement of the induced 233 Pa and 239 Np. These plastics typically contain macro amounts of silicon, bromine and antimony and nanogram per gram amounts of thorium and uranium. The radiochemical method provides the necessary sensitivity and makes it possible to easily attain adequate decontamination of the tiny amounts of 233 Pa and 239 Np from the high levels of radioactive bromine and antimony. 8 refs

  1. Resistance of Gram-positive bacteria to nisin is not determined by Lipid II levels

    NARCIS (Netherlands)

    Kramer, NE; Smid, EJ; Kok, J; de Kruijff, B; Kuipers, OP; Breukink, E; Kramer, Naomi E.; Smid, Eddy J.

    2004-01-01

    Lipid II is essential for nisin-mediated pore formation at nano-molar concentrations. We tested whether nisin resistance could result from different Lipid II levels, by comparing the maximal Lipid II pool in Micrococcus flavus (sensitive) and Listeria monocytogenes (relatively insensitive) and their

  2. Gram-Scale Synthesis of Highly Active and Durable Octahedral PtNi Nanoparticle Catalysts for Proton Exchange Membrane Fuel Cell

    DEFF Research Database (Denmark)

    Choi, Juhyuk; Jang, Jue-Hyuk; Roh, Chi-Woo

    2018-01-01

    for the commercialization of PEMFCs. In this study, we focus on gram-scale synthesis of octahedral PtNi nanoparticles with Pt overlayers (PtNi@Pt) supported on the carbon, resulting in enhanced catalytic activity and durability. Such PtNi@Pt catalysts show high mass activity (1.24 A mgPt−1) at 0.9 V (vs RHE) for the ORR......Proton exchange membrane fuel cells (PEMFC) are regarded as a promising renewable energy source for a future hydrogen energy society. However, highly active and durable catalysts are required for the PEMFCs because of their intrinsic high overpotential at the cathode and operation under the acidic...... condition for oxygen reduction reaction (ORR). Since the discovery of the exceptionally high surface activity of Pt3Ni(111), the octahedral PtNi nanoparticles have been synthesized and tested. Nonetheless, their milligram-scale synthesis method and poor durability make them unsuitable...

  3. Facile synthesis of gold nanoparticles on propylamine functionalized SBA-15 and effect of surface functionality of its enhanced bactericidal activity against gram positive bacteria

    International Nuclear Information System (INIS)

    Bhuyan, Diganta; Saikia, Mrinal; Saikia, Lakshi; Gogoi, Animesh; Saikia, Ratul

    2015-01-01

    The facile synthesis of an SBA-15-pr- + NH 3 .Au 0 nano-hybrid material by spontaneous autoreduction of aqueous chloroaurate anions on propylamine functionalized SBA-15 was successfully demonstrated. The as-synthesized SBA-15-pr- + NH 3 .Au 0 nano-hybrid material was well characterized using low and wide angle x-ray diffraction (XRD), N 2 adsorption–desorption isotherms, Fourier transform infrared (FTIR), transmission electron microscopy (TEM), scanning electron microscopy-energy dispersive x-ray spectroscopy (SEM-EDX), x-ray photoelectron spectroscopy (XPS), UV-Visible spectroscopy and atomic absorption spectroscopy (AAS). The activity of the nano-hybrid material as a potent bactericidal agent was successfully tested against Gram positive/negative bacteria viz. Bacillus subtilis, Staphylococcus aureus, Escherichia coli and Pseudomonas aeruginosa. The colony killing percentage of Gram positive bacteria was found to be higher than Gram negative bacteria due to the stronger electrostatic interaction between the positively-charged amine functionality of SBA-15 and the negatively charged functionality of the bacterial cell wall. (paper)

  4. Python based high-level synthesis compiler

    Science.gov (United States)

    Cieszewski, Radosław; Pozniak, Krzysztof; Romaniuk, Ryszard

    2014-11-01

    This paper presents a python based High-Level synthesis (HLS) compiler. The compiler interprets an algorithmic description of a desired behavior written in Python and map it to VHDL. FPGA combines many benefits of both software and ASIC implementations. Like software, the mapped circuit is flexible, and can be reconfigured over the lifetime of the system. FPGAs therefore have the potential to achieve far greater performance than software as a result of bypassing the fetch-decode-execute operations of traditional processors, and possibly exploiting a greater level of parallelism. Creating parallel programs implemented in FPGAs is not trivial. This article describes design, implementation and first results of created Python based compiler.

  5. Rapid Assessment of Resistance to Antibiotic Inhibitors of Protein Synthesis in the Gram-Positive Pathogens, Enterococcus faecalis and Streptococcus pneumoniae, Based on Evaluation of the Lytic Response.

    Science.gov (United States)

    Otero, Fátima; Tamayo, María; Santiso, Rebeca; Gosálvez, Jaime; Bou, Germán; Fernández, José Luis

    2017-04-01

    A novel assay for rapid determination of resistance to antibiotic inhibitors of protein synthesis was developed for the gram-positive pathogens, Enterococcus faecalis and Streptococcus pneumoniae. To this purpose, a lytic response was obtained by a brief incubation with lysozyme or a mixture of lysozyme, Triton X-100, and EDTA for E. faecalis (n = 82) and S. pneumoniae (n = 51), respectively. Lysis was quantified by visualizing the released nucleoids. Antibiotic-susceptible bacteria treated with Clinical and Laboratory Standards Institute (CLSI) breakpoint doses of erythromycin, azithromycin, or doxycycline that inhibited protein synthesis demonstrated a large reduction of lysed cells with respect to the control, that is, without antibiotics. However, cell lysis prevention was much lower in nonsusceptible strains, with unsuccessful inhibition of protein synthesis. ROC analysis showed that a reduction value of ≥35.6% and ≥40.4% discriminates susceptible and nonsusceptible strains for erythromycin and for doxycycline, respectively, in E. faecalis, whereas ≥20.0% is adequate for both macrolides and doxycycline in S. pneumoniae. Resistant stains were identified in 90-120 min with sensitivity and specificity between 91.7% and 100%. This is a proof of concept that evaluation of the lytic response may be a rapid and efficient test for determination of resistance to antibiotic inhibitors of protein synthesis.

  6. Rapid changes in the serum total protein and globulin levels in complications caused by facultatively pathogenic Gram-negative bacteria.

    Science.gov (United States)

    Petrás, G; Kiss, S; Juraszek, J; Merétey, K

    1978-01-01

    The changes in the levels of total protein and four globulin fractions were followed up throughout the entire course of complications caused by Gram-negative facultative pathogens in 37 acute cases of respiratory insufficiency accompanying different underlying illnesses and in 9 chronic, bedridden patients given artificial ventilation. At the onset of the infectious complications, in the first place in septic shock, the levels of various globulin fractions showed a decrease corresponding to a half-life of 2 to 4 days. Neither the increased catabolism, nor the protein losses by the urine and tracheal secretions offer a sufficient explanation for the escape of globulins of this extent from the plasma. It seems that this is a consequence of the increase in capillary permeability due to the effect of antigen-antibody reactions and that of endotoxin. As a result, in the critical phase of the infectious complications, at the point of culmination, e.g. in septic shock, diminished amount of different globulins is transported to the site of utilization, that is, to the inflammatory area.

  7. Efficient continuous-flow synthesis of novel 1,2,3-triazole-substituted β-aminocyclohexanecarboxylic acid derivatives with gram-scale production

    Directory of Open Access Journals (Sweden)

    Sándor B. Ötvös

    2013-07-01

    Full Text Available The preparation of novel multi-substituted 1,2,3-triazole-modified β-aminocyclohexanecarboxylic acid derivatives in a simple and efficient continuous-flow procedure is reported. The 1,3-dipolar cycloaddition reactions were performed with copper powder as a readily accessible Cu(I source. Initially, high reaction rates were achieved under high-pressure/high-temperature conditions. Subsequently, the reaction temperature was lowered to room temperature by the joint use of both basic and acidic additives to improve the safety of the synthesis, as azides were to be handled as unstable reactants. Scale-up experiments were also performed, which led to the achievement of gram-scale production in a safe and straightforward way. The obtained 1,2,3-triazole-substituted β-aminocyclohexanecarboxylates can be regarded as interesting precursors for drugs with possible biological effects.

  8. Expression levels of the receptor activator of NF-κB ligand and osteoprotegerin and the number of gram-negative bacteria in symptomatic and asymptomatic periapical lesions.

    Science.gov (United States)

    Carneiro, E; Parolin, A B; Wichnieski, C; Rosa, E A R; Silva Neto, U X; Westphalen, V P D; Fariniuk, L F; Johann, A C B R

    2017-01-01

    The study aimed to verify the potential correlation between the detected amount of gram-negative bacteria and the radiographic sizes of the lesions in patients with symptomatic and asymptomatic apical periodontitis. Furthermore, to evaluate whether the expression of receptor activator of NF-κB ligand (RANKL) and osteoprotegerin (OPG) and the RANKL/OPG ratio are differentially regulated in both groups. Twenty patients with periapical lesions were divided into two groups: symptomatic (SYM) n=10 and asymptomatic (ASYM) n=10. After periapical surgery, the lesions were collected and processed for histological examination, and immunohistochemistry. The percentage of RANKL- and OPG-immunopositive areas relative to the total area of the microscopic field was calculated. For gram staining, the number of gram-negative cells per microscopic field was assessed. The radiographs of each patient were processed and measured. The Student's t-test and the Pearson correlation coefficient were performed. The SYM group showed a significantly higher number of gram-negative cells (p=0.007) when compared to the ASYM group. A higher number of gram-negative bacteria occurred more frequently in larger periapical lesions and the SYM group (p=0.03). The expression for RANKL and OPG and the RANKL/OPG ratio were not significantly different between the groups. There was a significant positive correlation between the number of bacteria and OPG levels in the SYM group (p=0.01). The number of bacteria seems to influence the symptoms and the radiographic size of a periapical lesion. Gram-negative bacteria may play an important role in OPG activity in the SYM group. Copyright © 2016 Elsevier Ltd. All rights reserved.

  9. Competitive binding of polyethyleneimine-coated gold nanoparticles to enzymes and bacteria: a key mechanism for low-level colorimetric detection of gram-positive and gram-negative bacteria

    International Nuclear Information System (INIS)

    Thiramanas, Raweewan; Laocharoensuk, Rawiwan

    2016-01-01

    The article describes a simple and rapid method for colorimetric detection of bacteria. It is based on competitive binding of positively charged polyethyleneimine-coated gold nanoparticles (PEI-AuNPs) to negatively charged enzymes and bacteria. The PEI-AuNPs are electrostatically attracted by both the bacterial surface and the enzyme β-galactosidase (β-Gal). Binding to the latter results in the inhibition of enzyme activity. However, in the presence of a large number of bacteria, the PEI-AuNPs preferentially bind to bacteria. Hence, the enzyme will not be inhibited and its activity can be colorimetrically determined via hydrolysis of the chromogenic substrate chlorophenol red β-D-galactopyranoside (CPRG). The detection limit of this assay is as low as 10 cfu·mL −1 , and the linear range extends from 10 6 to 10 8 cfu·mL −1 . The assay is applicable to both Gram-negative (such as enterotoxigenic Escherichia coli; ETEC) and Gram-positive (Staphylococcus aureus; S. aureus) bacteria. Results are obtained within 10 min using an optical reader, and within 2–3 h by bare-eye detection. The method was applied to the identification of ETEC contamination at a level of 10 cfu·mL −1 in spiked drinking water. Given its low detection limit and rapidity (sample preconcentration is not required), this method holds great promise for on-site detection of total bacterial contamination. (author)

  10. Gram-scale solution-phase synthesis of selective sodium bicarbonate co-transport inhibitor S0859: in vitro efficacy studies in breast cancer cells.

    Science.gov (United States)

    Larsen, Ann M; Krogsgaard-Larsen, Niels; Lauritzen, Gitte; Olesen, Christina W; Honoré Hansen, Steen; Boedtkjer, Ebbe; Pedersen, Stine F; Bunch, Lennart

    2012-10-01

    Na(+)-coupled HCO(3)(-) transporters (NBCs) mediate the transport of bicarbonate ions across cell membranes and are thus ubiquitous regulators of intracellular pH. NBC dysregulation is associated with a range of diseases; for instance, NBCn1 is strongly up-regulated in a model of ErbB2-dependent breast cancer, a malignant and widespread cancer with no targeted treatment options, and single-nucleotide polymorphisms in NBCn1 genetically link to breast cancer development and hypertension. The N-cyanosulfonamide S0859 has been shown to selectively inhibit NBCs, and its availability on the gram scale is therefore of significant interest to the scientific community. Herein we describe a short and efficient synthesis of S0859 with an overall yield of 45 % from commercially available starting materials. The inhibitory effect of S0859 on recovery of intracellular pH after an acid load was verified in human and murine cancer cell lines in Ringer solutions. However, S0859 binds very strongly to components in plasma, and accordingly, measurements on isolated murine tissues showed no effect of S0859 at concentrations up to 50 μM. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  11. Influence of the time of day and fasting duration on glucose level following a 1-hour, 50-gram glucose challenge test in pregnant women.

    Directory of Open Access Journals (Sweden)

    Panchalli Wang

    Full Text Available BACKGROUND: Previous studies have shown that the time of day (TD of glucose measurement and the fasting duration (FD influence the glucose levels in adults. Few studies have examined the effects of the TD and FD on the glucose level following a 1-hour, 50-gram glucose challenge test (GCT in pregnant women in screening for or diagnosing gestational diabetes mellitus (GDM. The objective of this study was to investigate the influence of the TD (morning, afternoon, night and the FD (the time of the last food ingestion as follows: ≤1 hour, 1-2 hours, and >2 hours by examining their combined effects on the glucose levels following a 50-gram GCT in pregnant women. METHODS AND RESULTS: We analyzed the data of 1,454 non-diabetic pregnant Taiwanese women in a prospective study. Multiple linear regression and multiple logistic regression were used to estimate the relationships between the 9 TD-FD groups and the continuous and binary glucose levels (cut-off at 140 mg/dL following a 50-gram GCT, after adjusting for maternal age, nulliparity, pre-pregnancy body mass index, and weight gain. Different TD and FD groups were associated with variable glucose responses to the 50-gram GCT, some of which were significant. The estimate coefficients (β of the TD-FD groups "night, ≤1 hr" and "night, 1-2 hr" revealed significantly lower glucose concentrations [β (95% confidence interval [CI]: -6.46 (-12.53, -0.38 and -6.85 (-12.50, -1.20] compared with the "morning, >2 hr" group. The TD-FD groups "afternoon, ≤1 hr" and "afternoon, 1-2 hr" showed significantly lower odds ratios (OR of a positive GCT; the adjusted ORs (95% CI were 0.54 (0.31-0.95 and 0.58 (0.35-0.96, respectively. CONCLUSIONS: Our findings demonstrate the importance of standardizing the TD and FD for the 1-hour, 50-gram GCT. In screening for and diagnosing GDM, the TD and FD are modifiable factors that should be considered in clinical practice and epidemiological studies.

  12. Gram-scale synthesis of catalytic Co9S8 nanocrystal ink as a cathode material for spray-deposited, large-area dye-sensitized solar cells.

    Science.gov (United States)

    Chang, Shu-Hao; Lu, Ming-De; Tung, Yung-Liang; Tuan, Hsing-Yu

    2013-10-22

    We report the development of Co9S8 nanocrystals as a cost-effective cathode material that can be readily combined with spraying techniques to fabricate large-area dye-sensitized solar cell (DSSC) devices and can be further connected with series or parallel cell architectures to obtain a relatively high output voltage or current. A gram-scale synthesis of Co9S8 nanocrystal is carried out via a noninjection reaction by mixing anhydrous CoCl2 with trioctylphosphine (TOP), dodecanethiol and oleylamine (OLA) at 250 °C. The Co9S8 nanocrystals possess excellent catalytic ability with respect to I(-)/I3(-) redox reactions. The Co9S8 nanocrystals are prepared as nanoinks to fabricate uniform, crack-free Co9S8 thin films on different substrates by using a spray deposition technique. These Co9S8 films are used as counter electrodes assembled with dye-adsorbed TiO2 photoanodes to fabricate DSSC devices having a working area of 2 cm(2) and an average power conversion efficiency (PCE) of 7.02 ± 0.18% under AM 1.5 solar illumination, which is comparable with the PCE of 7.2 ± 0.12% obtained using a Pt cathode. Furthermore, six 2 cm(2)-sized DSSC devices connected in series output an open-circuit voltage of 4.2 V that can power a wide range of electronic devices such as LED arrays and can charge commercial lithium ion batteries.

  13. Modal intersection types, two-level languages, and staged synthesis

    DEFF Research Database (Denmark)

    Henglein, Fritz; Rehof, Jakob

    2016-01-01

    -linguistic framework for staged program synthesis, where metaprograms are automatically synthesized which, when executed, generate code in a target language. We survey the basic theory of staged synthesis and illustrate by example how a two-level language theory specialized from λ∩ ⎕ can be used to understand......A typed λ-calculus, λ∩ ⎕, is introduced, combining intersection types and modal types. We develop the metatheory of λ∩ ⎕, with particular emphasis on the theory of subtyping and distributivity of the modal and intersection type operators. We describe how a stratification of λ∩ ⎕ leads to a multi...... the process of staged synthesis....

  14. Methods for Confirming the Gram Reaction of Gram-variable Bacillus Species Isolated from Tobacco

    Directory of Open Access Journals (Sweden)

    Morin A

    2014-12-01

    Full Text Available Bacillus is a predominant genus of bacteria isolated from tobacco. The Gram stain is the most commonly used and most important of all diagnostic staining techniques in microbiology. In order to help confirm the Gram positivity of Bacillus isolates from tobacco, three methods using the chemical differences of the cell wall and membrane of Gram-positive and Gram-negative bacteria were investigated: the KOH (potassium hydroxide, the LANA (L-alanine-4-nitroanilide, and the vancomycin susceptibility tests. When colonies of Gram-negative bacteria are treated with 3% KOH solution, a slimy suspension is produced, probably due to destruction of the cell wall and liberation of deoxyribonucleic acid (DNA. Gram-positive cell walls resist KOH treatment. The LANA test reveals the presence of a cell wall aminopeptidase that hydrolyzes the L-alanine-4-nitroanilide in Gram-negative bacteria. This enzyme is absent in Gram-positive bacteria. Vancomycin is a glycopeptide antibiotic inhibiting the cell wall peptido-glycan synthesis of Gram-positive microorganisms. Absence of lysis with KOH, absence of hydrolysis of LANA, and susceptibility to vancomycin were used with the Gram reaction to confirm the Gram positivity of various Bacillus species isolated from tobacco. B. laevolacticus excepted, all Bacillus species tested showed negative reactions to KOH and LANA tests, and all species were susceptible to vancomycin (5 and 30 µg.

  15. Species-Level Discrimination of Psychrotrophic Pathogenic and Spoilage Gram-Negative Raw Milk Isolates Using a Combined MALDI-TOF MS Proteomics-Bioinformatics-based Approach.

    Science.gov (United States)

    Vithanage, Nuwan R; Bhongir, Jeevana; Jadhav, Snehal R; Ranadheera, Chaminda S; Palombo, Enzo A; Yeager, Thomas R; Datta, Nivedita

    2017-06-02

    Identification of psychrotrophic pathogenic and spoilage Gram-negative bacteria using rapid and reliable techniques is important in commercial milk processing, as these bacteria can produce heat-resistant proteases and act as postprocessing contaminants in pasteurized milk. Matrix-assisted laser desorption/ionization-time-of-flight mass spectrometry (MALDI-TOF MS) is a proven technology for identification of bacteria in food, however, may require optimization for identification of pathogenic and spoilage bacteria in milk and dairy products. The current study evaluated the effects of various culture conditions and sample preparation methods on assigning of raw milk isolates to the species level by MALDI-TOF MS. The results indicated that culture media, incubation conditions (temperature and time), and sample preparation significantly affected the identification rates of bacteria to the species level. Nevertheless, the development of spectral libraries of isolates grown on different media using a web tool for hierarchical clustering of peptide mass spectra (SPECLUST) followed by a ribosomal protein based bioinformatics approach significantly enhanced the assigning of bacteria, with at least one unique candidate biomarker peak identified for each species. Phyloproteomic relationships based on spectral profiles were compared to phylogenetic analysis using 16S rRNA gene sequences and demonstrated similar clustering patterns with significant discriminatory power. Thus, with appropriate optimization, MALDI-TOF MS is a valuable tool for species-level discrimination of pathogenic and milk spoilage bacteria.

  16. Measurement of Heme Synthesis Levels in Mammalian Cells.

    Science.gov (United States)

    Hooda, Jagmohan; Alam, Maksudul; Zhang, Li

    2015-07-09

    Heme serves as the prosthetic group for a wide variety of proteins known as hemoproteins, such as hemoglobin, myoglobin and cytochromes. It is involved in various molecular and cellular processes such as gene transcription, translation, cell differentiation and cell proliferation. The biosynthesis levels of heme vary across different tissues and cell types and is altered in diseased conditions such as anemia, neuropathy and cancer. This technique uses [4-(14)C] 5-aminolevulinic acid ([(14)C] 5-ALA), one of the early precursors in the heme biosynthesis pathway to measure the levels of heme synthesis in mammalian cells. This assay involves incubation of cells with [(14)C] 5-ALA followed by extraction of heme and measurement of the radioactivity incorporated into heme. This procedure is accurate and quick. This method measures the relative levels of heme biosynthesis rather than the total heme content. To demonstrate the use of this technique the levels of heme biosynthesis were measured in several mammalian cell lines.

  17. Use of the Lactococcal nisA Promoter To Regulate Gene Expression in Gram-Positive Bacteria : Comparison of Induction Level and Promoter Strength

    NARCIS (Netherlands)

    Eichenbaum, Zehava; Federle, Michael J.; Marra, Diana; Vos, Willem M. de; Kuipers, Oscar P.; Kleerebezem, Michiel; Scott, June R.

    1998-01-01

    We characterized the regulated activity of the lactococcal nisA promoter in strains of the gram-positive species Streptococcus pyogenes, Streptococcus agalactiae, Streptococcus pneumoniae, Enterococcus faecalis, and Bacillus subtilis. nisA promoter activity was dependent on the proteins NisR and

  18. Gram-scale synthesis of highly crystalline, 0-D and 1-D SnO2 nanostructures through surfactant-free hydrothermal process

    International Nuclear Information System (INIS)

    Pal, Umapada; Pal, Mou; Sánchez Zeferino, Raul

    2012-01-01

    We report the synthesis of highly crystalline SnO 2 nanoparticle and nanorod structures with average diameters well within quantum confinement limit (3.5−6.4 nm), through surfactant-free hydrothermal synthesis. The size and shape of the nanostructures could be controlled by controlling the pH (4.5–13.0) of the reaction mixture and the temperature of hydrothermal treatment. Probable mechanisms for the variation of particle size and growth of one-dimensional structures are presented considering the size-dependent crystal solubility at lower pH values of the reaction solution and Ostwald ripening of the quasi-spherical nanoparticles at higher pH values, respectively. Variation of optical band gap energy and hence the effects of quantum confinement in the nanostructures have been studied.

  19. Multiple Word-Length High-Level Synthesis

    Directory of Open Access Journals (Sweden)

    Coussy Philippe

    2008-01-01

    Full Text Available Abstract Digital signal processing (DSP applications are nowadays widely used and their complexity is ever growing. The design of dedicated hardware accelerators is thus still needed in system-on-chip and embedded systems. Realistic hardware implementation requires first to convert the floating-point data of the initial specification into arbitrary length data (finite-precision while keeping an acceptable computation accuracy. Next, an optimized hardware architecture has to be designed. Considering uniform bit-width specification allows to use traditional automated design flow. However, it leads to oversized design. On the other hand, considering non uniform bit-width specification allows to get a smaller circuit but requires complex design tasks. In this paper, we propose an approach that inputs a C/C++ specification. The design flow, based on high-level synthesis (HLS techniques, automatically generates a potentially pipeline RTL architecture described in VHDL. Both bitaccurate integer and fixed-point data types can be used in the input specification. The generated architecture uses components (operator, register, etc. that have different widths. The design constraints are the clock period and the throughput of the application. The proposed approach considers data word-length information in all the synthesis steps by using dedicated algorithms. We show in this paper the effectiveness of the proposed approach through several design experiments in the DSP domain.

  20. Multiple Word-Length High-Level Synthesis

    Directory of Open Access Journals (Sweden)

    Dominique Heller

    2008-09-01

    Full Text Available Digital signal processing (DSP applications are nowadays widely used and their complexity is ever growing. The design of dedicated hardware accelerators is thus still needed in system-on-chip and embedded systems. Realistic hardware implementation requires first to convert the floating-point data of the initial specification into arbitrary length data (finite-precision while keeping an acceptable computation accuracy. Next, an optimized hardware architecture has to be designed. Considering uniform bit-width specification allows to use traditional automated design flow. However, it leads to oversized design. On the other hand, considering non uniform bit-width specification allows to get a smaller circuit but requires complex design tasks. In this paper, we propose an approach that inputs a C/C++ specification. The design flow, based on high-level synthesis (HLS techniques, automatically generates a potentially pipeline RTL architecture described in VHDL. Both bitaccurate integer and fixed-point data types can be used in the input specification. The generated architecture uses components (operator, register, etc. that have different widths. The design constraints are the clock period and the throughput of the application. The proposed approach considers data word-length information in all the synthesis steps by using dedicated algorithms. We show in this paper the effectiveness of the proposed approach through several design experiments in the DSP domain.

  1. Comparison of traditional phenotypic identification methods with partial 5' 16S rRNA gene sequencing for species-level identification of nonfermenting Gram-negative bacilli.

    Science.gov (United States)

    Cloud, Joann L; Harmsen, Dag; Iwen, Peter C; Dunn, James J; Hall, Gerri; Lasala, Paul Rocco; Hoggan, Karen; Wilson, Deborah; Woods, Gail L; Mellmann, Alexander

    2010-04-01

    Correct identification of nonfermenting Gram-negative bacilli (NFB) is crucial for patient management. We compared phenotypic identifications of 96 clinical NFB isolates with identifications obtained by 5' 16S rRNA gene sequencing. Sequencing identified 88 isolates (91.7%) with >99% similarity to a sequence from the assigned species; 61.5% of sequencing results were concordant with phenotypic results, indicating the usability of sequencing to identify NFB.

  2. Stool Gram stain

    Science.gov (United States)

    ... stool sample. The Gram stain method is sometimes used to quickly diagnose bacterial infections. How the Test is Performed You will need to collect a stool sample. There are many ways to collect the sample. You can catch the stool on plastic wrap that is loosely placed over the toilet bowl ...

  3. High-Level Synthesis: Productivity, Performance, and Software Constraints

    Directory of Open Access Journals (Sweden)

    Yun Liang

    2012-01-01

    Full Text Available FPGAs are an attractive platform for applications with high computation demand and low energy consumption requirements. However, design effort for FPGA implementations remains high—often an order of magnitude larger than design effort using high-level languages. Instead of this time-consuming process, high-level synthesis (HLS tools generate hardware implementations from algorithm descriptions in languages such as C/C++ and SystemC. Such tools reduce design effort: high-level descriptions are more compact and less error prone. HLS tools promise hardware development abstracted from software designer knowledge of the implementation platform. In this paper, we present an unbiased study of the performance, usability and productivity of HLS using AutoPilot (a state-of-the-art HLS tool. In particular, we first evaluate AutoPilot using the popular embedded benchmark kernels. Then, to evaluate the suitability of HLS on real-world applications, we perform a case study of stereo matching, an active area of computer vision research that uses techniques also common for image denoising, image retrieval, feature matching, and face recognition. Based on our study, we provide insights on current limitations of mapping general-purpose software to hardware using HLS and some future directions for HLS tool development. We also offer several guidelines for hardware-friendly software design. For popular embedded benchmark kernels, the designs produced by HLS achieve 4X to 126X speedup over the software version. The stereo matching algorithms achieve between 3.5X and 67.9X speedup over software (but still less than manual RTL design with a fivefold reduction in design effort versus manual RTL design.

  4. Microbiological Synthesis of 2H-Labeled Phenylalanine, Alanine, Valine, and Leucine/Isoleucine with Different Degrees of Deuterium Enrichment by the Gram-Positive Facultative Methylotrophic Bacterium Вrevibacterium Methylicum

    Directory of Open Access Journals (Sweden)

    Oleg V. Mosin, PhD¹

    2013-06-01

    Full Text Available The microbiological synthesis of [2H]amino acids was performed by the conversion of low molecular weight substrates ([U-2H]MeOH and 2H2O using the Gram-positive aerobic facultative methylotrophic bacterium Brevibacterium methylicum, an L-phenylalanine producer, realizing the NAD+ dependent methanol dehydrogenase (EC 1.6.99.3 variant of the ribulose-5-monophosphate (RuMP cycle of carbon assimilation. In this process, the adapted cells of the methylotroph with enhanced growth characteristics were used on a minimal salt medium M9, supplemented with 2% (v/v [U-2H]MeOH and an increasing gradient of 2Н2O concentration from 0; 24.5, 49.0; 73.5 up to 98% (v/v 2Н2O. Alanine, valine, and leucine/isoleucine were produced and accumulated exogeneously in quantities of 5–6 mol, in addition to the main product of biosynthesis. This method enables the production of [2Н]amino acids with different degrees of deuterium enrichment, depending on the 2Н2O concentration in the growth medium, from 17 at.% 2Н (on the growth medium with 24.5 % (v/v 2Н2О up to 75 at.% 2Н (on the growth medium with 98 % (v/v 2Н2О. This has been confirmed with the data from the electron impact (EI mass spectrometry analysis of the methyl ethers of N-dimethylamino(naphthalene-5-sulfochloride [2H]amino acids under these experimental conditions.

  5. The Causes of Post-Operative Meningitis: The Comparison Of Gram-Negative and Gram-Positive Pathogens.

    Science.gov (United States)

    Kurtaran, Behice; Kuscu, Ferit; Ulu, Aslihan; Inal, Ayse Seza; Komur, Suheyla; Kibar, Filiz; Cetinalp, Nuri Eralp; Ozsoy, Kerem Mazhar; Arslan, Yusuf Kemal; Aksu, Hasan Salih; Tasova, Yesim

    2017-06-20

    In this study, we aim to determine the microbiological etiology in critically ill neurosurgical patients with nosocomial meningitis (NM) and show the impact of Gram-negative rods and differences of patient's characteristics, clinical and prognostic measures between Gram-negative and Gram-positive meningitis. In this prospective, one center study we reviewed all adult patients hospitalized during a 12-year period and identified pathogens isolated from post-neurosurgical cases of NM. Demographic, clinical, and treatment characteristics were noted from the medical records. Of the 134 bacterial NM patients, 78 were male and 56 were female, with a mean age of 46±15.9 and median age of 50 (18-80) years. 141 strains isolated; 82 (58.2%) were Gram negative, 59 (41.8%) were Gram positive. Most common isolated microorganism was Acinetobacter baumannii (%34.8). In comparison of mortality data shows that the patients who have meningitis with Gram-negative pathogens have higher mortality than with Gram positives (p=0.034). The duration between surgery and meningitis was shorter in Gram negative meningitis cases compared to others (p=0.045) but the duration between the diagnosis and death was shorter in Gram-positive meningitis cases compared to Gram negatives (p= 0.017). CSF protein and lactate level were higher and glucose level was lower in cases of NM with Gram negatives (p value were respectively, 0.022, 0.039 and 0.049). As conclusions; in NM, Gram-negative pathogens were seen more frequently; A.baumanni was the predominant pathogen; and NM caused by Gram negatives had worse clinical and laboratory characteristic and prognostic outcome than Gram positives.

  6. Low Power Design with High-Level Power Estimation and Power-Aware Synthesis

    CERN Document Server

    Ahuja, Sumit; Shukla, Sandeep Kumar

    2012-01-01

    Low-power ASIC/FPGA based designs are important due to the need for extended battery life, reduced form factor, and lower packaging and cooling costs for electronic devices. These products require fast turnaround time because of the increasing demand for handheld electronic devices such as cell-phones, PDAs and high performance machines for data centers. To achieve short time to market, design flows must facilitate a much shortened time-to-product requirement. High-level modeling, architectural exploration and direct synthesis of design from high level description enable this design process. This book presents novel research techniques, algorithms,methodologies and experimental results for high level power estimation and power aware high-level synthesis. Readers will learn to apply such techniques to enable design flows resulting in shorter time to market and successful low power ASIC/FPGA design. Integrates power estimation and reduction for high level synthesis, with low-power, high-level design; Shows spec...

  7. Clinical pulmonary infection score and a spot serum procalcitonin level to guide discontinuation of antibiotics in ventilator-associated pneumonia: a study in a single institution with high prevalence of nonfermentative gram-negative bacilli infection.

    Science.gov (United States)

    Wongsurakiat, Phunsup; Tulatamakit, Sirapat

    2018-01-01

    Background We wanted to determine the impact of combined Clinical Pulmonary Infection Score (CPIS) and a spot serum procalcitonin (PCT)-guided protocol to shorten the duration of antibiotic treatment in patients with ventilator-associated pneumonia (VAP), mainly caused by nonfermentative gram-negative bacilli (NF-GNB). Methods Patients with VAP who received appropriate antibiotics for 7 days, temperature ⩽ 37.8°C, without shock, and CPIS ⩽ 6 were allocated to the PCT group or conventional group according to the treating physicians' decisions. In the PCT group, antibiotics were stopped if the PCT level on day 8 level appeared effective and safe to guide discontinuation of antibiotic treatment in patients with VAP caused by NF-GNB. TCTR20160726002.

  8. Numerical Gram-Schmidt orthonormalization

    International Nuclear Information System (INIS)

    Werneth, Charles M; Dhar, Mallika; Maung, Khin Maung; Sirola, Christopher; Norbury, John W

    2010-01-01

    A numerical Gram-Schmidt orthonormalization procedure is presented for constructing an orthonormal basis function set from a non-orthonormal set, when the number of basis functions is large. This method will provide a pedagogical illustration of the Gram-Schmidt procedure and can be presented in classes on numerical methods or computational physics.

  9. Protein synthesis levels are increased in a subset of individuals with Fragile X syndrome

    DEFF Research Database (Denmark)

    Jacquemont, Sébastien; Pacini, Laura; Jønch, Aia E

    2018-01-01

    architecture and plasticity. Preclinical studies revealed that pharmacological interventions restore those deficits, which are thought to mediate the FXS cognitive and behavioral symptoms. Here we characterized the de novo rate of protein synthesis in patients with FXS and their relationship with clinical...... severity. We measured the rate of protein synthesis in fibroblasts derived from 32 individuals with FXS and from 17 controls as well as in fibroblasts and primary neurons of 27 Fmr1 KO mice and 20 controls. Here we show that levels of protein synthesis are increased in fibroblasts of individuals with FXS...... and Fmr1 KO mice. However, this cellular phenotype displays a broad distribution and a proportion of fragile X individuals and Fmr1 KO mice do not show increased levels of protein synthesis, having measures in the normal range. Because the same Fmr1 KO animal measures in fibroblasts predict those...

  10. Mechanistic antimicrobial approach of extracellularly synthesized silver nanoparticles against gram positive and gram negative bacteria

    Energy Technology Data Exchange (ETDEWEB)

    Tamboli, Dhawal P.; Lee, Dae Sung, E-mail: daesung@knu.ac.kr

    2013-09-15

    Highlights: • Bacterial extracelluar enzymes stabilized the silver nanoparticles (AgNPs). • AgNPs formation was characterized by analytical techniques such as UV–vis, TEM, and FTIR. • AgNPs showed obvious antimicrobial activity against both gram positive and gram negative microorganisms. • A mechanism of AgNPs’ antimicrobial activity was proposed. -- Abstract: The development of eco-friendly and reliable processes for the synthesis of nanoparticles has attracted considerable interest in nanotechnology. In this study, an extracellular enzyme system of a newly isolated microorganism, Exiguobacterium sp. KNU1, was used for the reduction of AgNO{sub 3} solutions to silver nanoparticles (AgNPs). The extracellularly biosynthesized AgNPs were characterized by UV–vis spectroscopy, Fourier transform infra-red spectroscopy and transmission electron microscopy. The AgNPs were approximately 30 nm (range 5–50 nm) in size, well-dispersed and spherical. The AgNPs were evaluated for their antimicrobial effects on different gram negative and gram positive bacteria using the minimum inhibitory concentration method. Reasonable antimicrobial activity against Salmonella typhimurium, Pseudomonas aeruginosa, Escherichia coli and Staphylococcus aureus was observed. The morphological changes occurred in all the microorganisms tested. In particular, E. coli exhibited DNA fragmentation after being treated with the AgNPs. Finally, the mechanism for their bactericidal activity was proposed according to the results of scanning electron microscopy and single cell gel electrophoresis.

  11. Mechanistic antimicrobial approach of extracellularly synthesized silver nanoparticles against gram positive and gram negative bacteria

    International Nuclear Information System (INIS)

    Tamboli, Dhawal P.; Lee, Dae Sung

    2013-01-01

    Highlights: • Bacterial extracelluar enzymes stabilized the silver nanoparticles (AgNPs). • AgNPs formation was characterized by analytical techniques such as UV–vis, TEM, and FTIR. • AgNPs showed obvious antimicrobial activity against both gram positive and gram negative microorganisms. • A mechanism of AgNPs’ antimicrobial activity was proposed. -- Abstract: The development of eco-friendly and reliable processes for the synthesis of nanoparticles has attracted considerable interest in nanotechnology. In this study, an extracellular enzyme system of a newly isolated microorganism, Exiguobacterium sp. KNU1, was used for the reduction of AgNO 3 solutions to silver nanoparticles (AgNPs). The extracellularly biosynthesized AgNPs were characterized by UV–vis spectroscopy, Fourier transform infra-red spectroscopy and transmission electron microscopy. The AgNPs were approximately 30 nm (range 5–50 nm) in size, well-dispersed and spherical. The AgNPs were evaluated for their antimicrobial effects on different gram negative and gram positive bacteria using the minimum inhibitory concentration method. Reasonable antimicrobial activity against Salmonella typhimurium, Pseudomonas aeruginosa, Escherichia coli and Staphylococcus aureus was observed. The morphological changes occurred in all the microorganisms tested. In particular, E. coli exhibited DNA fragmentation after being treated with the AgNPs. Finally, the mechanism for their bactericidal activity was proposed according to the results of scanning electron microscopy and single cell gel electrophoresis

  12. Present-day sea level rise: a synthesis

    International Nuclear Information System (INIS)

    Cazenave, A.; Llovel, W.; Lombard, A.

    2008-01-01

    Measuring sea level change and understanding its causes have improved considerably in the recent years, essentially because new in situ and remote sensing data sets have become available. Here we report on the current knowledge of present-day sea level change. We briefly present observational results on sea level change from satellite altimetry since 1993 and tide gauges for the past century. We next discuss recent progress made in quantifying the processes causing sea level change on time scales ranging from years to decades, i.e., thermal expansion, land ice mass loss and land water storage change. For the 1993-2003 decade, the sum of climate-related contributions agree well (within the error bars) with the altimetry-based sea level, half of the observed rate of rise being due to ocean thermal expansion, land ice plus land waters explaining the other half. Since about 2003, thermal expansion increase has stopped, whereas the sea level continues to rise, although at a reduced rate compared to the previous decade (2.5 mm/yr versus 3.1 mm/yr). Recent increases in glacier melting and ice mass loss from the ice sheets appear able to account alone for the rise in sea level reported over the last five years. (authors)

  13. Somite chrondrogenesis: alterations in cyclic AMP levels and proteoglycan synthesis

    International Nuclear Information System (INIS)

    Vasan, Nagaswamistri; Lamb, K.M.; Heick, A.E.

    1985-01-01

    Cyclic AMP (cAMP) levels have been shown to have a positive influence on chondrogenesis in limb buds and pelvic cartilage. In the present study the level of cAMP was measured during somite chondrogenesis in vitro and found to decrease from 1.38 pmol/μg DNA on day 0 to 0.9 pmol/μg DNA on day 6. Inclusion of notochord with somites caused a marked recution, with levels decreasing from 1.41 pmol/μg DNA on day 0 to 0.36 pmol/μg DNA on day 6. Concurrently, the incorporation of radioactive sulfate into sulfated glycosaminoglycans increased from day 3 to day 6 by 38% in somite and 77% in somite-notochord explants. The aggregation of proteoglycans was analyzed by gel chromatography and found to increase with a corresponding decrease in cAMP levels. The result indicate that a decrease in cAMP levels may be necessary for chondrogenic expression in somites. (author)

  14. Prognostic factors and monomicrobial necrotizing fasciitis: gram-positive versus gram-negative pathogens

    Directory of Open Access Journals (Sweden)

    Hsu Wei-Hsiu

    2011-01-01

    Full Text Available Abstract Background Monomicrobial necrotizing fasciitis is rapidly progressive and life-threatening. This study was undertaken to ascertain whether the clinical presentation and outcome for patients with this disease differ for those infected with a gram-positive as compared to gram-negative pathogen. Methods Forty-six patients with monomicrobial necrotizing fasciitis were examined retrospectively from November 2002 to January 2008. All patients received adequate broad-spectrum antibiotic therapy, aggressive resuscitation, prompt radical debridement and adjuvant hyperbaric oxygen therapy. Eleven patients were infected with a gram-positive pathogen (Group 1 and 35 patients with a gram-negative pathogen (Group 2. Results Group 2 was characterized by a higher incidence of hemorrhagic bullae and septic shock, higher APACHE II scores at 24 h post-admission, a higher rate of thrombocytopenia, and a higher prevalence of chronic liver dysfunction. Gouty arthritis was more prevalent in Group 1. For non-survivors, the incidences of chronic liver dysfunction, chronic renal failure and thrombocytopenia were higher in comparison with those for survivors. Lower level of serum albumin was also demonstrated in the non-survivors as compared to those in survivors. Conclusions Pre-existing chronic liver dysfunction, chronic renal failure, thrombocytopenia and hypoalbuminemia, and post-operative dependence on mechanical ventilation represent poor prognostic factors in monomicrobial necrotizing fasciitis. Patients with gram-negative monobacterial necrotizing fasciitis present with more fulminant sepsis.

  15. Synthesis and role of salicylic acid in wheat varieties with different levels of cadmium tolerance

    International Nuclear Information System (INIS)

    Kovács, Viktória; Gondor, Orsolya K.; Szalai, Gabriella; Darkó, Éva; Majláth, Imre; Janda, Tibor; Pál, Magda

    2014-01-01

    Highlights: • Cd induces the salicylic acid metabolism in wheat. • Salicylic acid is synthesized via benzoic acid and/or ortho-hydroxy-cinnamic acid. • Cd tolerance can be explained by the highly induced glutathione metabolism. • Salicylic acid signalling is correlated with glutathione-related mechanisms. - Abstract: Wheat genotypes with different endogenous SA contents were investigated, in order to reveal how cadmium influences salicylic acid (SA) synthesis, and to find possible relationships between SA and certain protective compounds (members of the antioxidants and the heavy metal detoxification system) and between the SA content and the level of cadmium tolerance. Cadmium exposure induced SA synthesis, especially in the leaves, and it is suggested that the phenyl-propanoid synthesis pathway is responsible for the accumulation of SA observed after cadmium stress. Cadmium influenced the synthesis and activation of protective compounds to varying extents in wheat genotypes with different levels of tolerance; the roots and leaves also responded differently to cadmium stress. Although a direct relationship was not found between the initial SA levels and the degree of cadmium tolerance, the results suggest that the increase in the root SA level during cadmium stress in the Mv varieties could be related with the enhancement of the internal glutathione cycle, thus inducing the antioxidant and metal detoxification systems, which promote Cd stress tolerance in wheat seedlings. The positive correlation between certain SA-related compounds and protective compounds suggests that SA-related signalling may also play a role in the acclimation to heavy metal stress

  16. Synthesis and role of salicylic acid in wheat varieties with different levels of cadmium tolerance

    Energy Technology Data Exchange (ETDEWEB)

    Kovács, Viktória; Gondor, Orsolya K.; Szalai, Gabriella; Darkó, Éva; Majláth, Imre; Janda, Tibor; Pál, Magda, E-mail: pal.magda@agrar.mta.hu

    2014-09-15

    Highlights: • Cd induces the salicylic acid metabolism in wheat. • Salicylic acid is synthesized via benzoic acid and/or ortho-hydroxy-cinnamic acid. • Cd tolerance can be explained by the highly induced glutathione metabolism. • Salicylic acid signalling is correlated with glutathione-related mechanisms. - Abstract: Wheat genotypes with different endogenous SA contents were investigated, in order to reveal how cadmium influences salicylic acid (SA) synthesis, and to find possible relationships between SA and certain protective compounds (members of the antioxidants and the heavy metal detoxification system) and between the SA content and the level of cadmium tolerance. Cadmium exposure induced SA synthesis, especially in the leaves, and it is suggested that the phenyl-propanoid synthesis pathway is responsible for the accumulation of SA observed after cadmium stress. Cadmium influenced the synthesis and activation of protective compounds to varying extents in wheat genotypes with different levels of tolerance; the roots and leaves also responded differently to cadmium stress. Although a direct relationship was not found between the initial SA levels and the degree of cadmium tolerance, the results suggest that the increase in the root SA level during cadmium stress in the Mv varieties could be related with the enhancement of the internal glutathione cycle, thus inducing the antioxidant and metal detoxification systems, which promote Cd stress tolerance in wheat seedlings. The positive correlation between certain SA-related compounds and protective compounds suggests that SA-related signalling may also play a role in the acclimation to heavy metal stress.

  17. Low-fat papadams from black gram-tapioca blends.

    Science.gov (United States)

    Annapure, U S; Michael, M; Singhal, R S; Kulkarni, P R

    1997-07-01

    Papadams, made from black gram (Phaseolus mungo) and largely manufactured on cottage scale are popular in the Indian dietary. Escalating prices of black gram coupled with abundant availability of tapioca flour at almost 1/8th the price of black gram prompted the study of papadam characteristics using blends of black gram and tapioca flour. Tapioca flour up to 25% substitution did not alter the sensory attributes. However, the expansibility of the product decreased on addition of tapioca flour; a fact which could be overcome by using carboxymethyl cellulose (CMC) at 3% level of black gram flour. This decreased the oil content to 19.7% and also increased the expansibility to 5.539%.

  18. Serum levels of polyamine synthesis enzymes increase in diabetic patients with breast cancer

    Directory of Open Access Journals (Sweden)

    V Kenan Çelik

    2017-09-01

    Full Text Available In this study, it was aimed to investigate the relationship between diabetes and breast cancer and the detection of enzymes and ornithine levels in polyamine synthesis pathway in diabetes, breast cancer and diabetic breast cancer patients. Methods: Ornithine, arginine decarboxylase, ornithine decarboxylase and agmatinase levels have been measured in serum of all groups. Ornithine levels were measured spectrophotometrically. Arginine decarboxylase, ornithine decarboxylase and agmatinase levels were determined by ELISA kits. Results: Except for the diabetic group, the levels of enzymes in the polyamine synthesis pathway were increased in all and statistically significant (P < 0.05. The increase in the levels of agmatinase was very important among the enzymes (P < 0.001. Conclusions: Decreased levels of polyamine synthase enzymes in diabetes mellitus were found to be increased patients with breast cancer. Whether and how diabetes-based breast cancer development relates to increase activity of enzymes responsible for polyamine synthesis requires further mechanistic and prospective monitoring studies in larger patient cohorts.

  19. Differential staining of bacteria: gram stain.

    Science.gov (United States)

    Moyes, Rita B; Reynolds, Jackie; Breakwell, Donald P

    2009-11-01

    In 1884, Hans Christian Gram, a Danish doctor, developed a differential staining technique that is still the cornerstone of bacterial identification and taxonomic division. This multistep, sequential staining protocol separates bacteria into four groups based on cell morphology and cell wall structure: Gram-positive cocci, Gram-negative cocci, Gram-positive rods, and Gram-negative rods. The Gram stain is useful for assessing bacterial contamination of tissue culture samples or for examining the Gram stain status and morphological features of bacteria isolated from mixed or isolated bacterial cultures. (c) 2009 by John Wiley & Sons, Inc.

  20. Will new antimicrobials overcome resistance among Gram-negatives?

    Science.gov (United States)

    Bassetti, Matteo; Ginocchio, Francesca; Mikulska, Małgorzata; Taramasso, Lucia; Giacobbe, Daniele Roberto

    2011-10-01

    The spread of resistance among Gram-positive and Gram-negative bacteria represents a growing challenge for the development of new antimicrobials. The pace of antibiotic drug development has slowed during the last decade and, especially for Gram-negatives, clinicians are facing a dramatic shortage in the availability of therapeutic options to face the emergency of the resistance problem throughout the world. In this alarming scenario, although there is a shortage of compounds reaching the market in the near future, antibiotic discovery remains one of the keys to successfully stem and maybe overcome the tide of resistance. Analogs of already known compounds and new agents belonging to completely new classes of antimicrobials are in early stages of development. Novel and promising anti-Gram-negative antimicrobials belong both to old (cephalosporins, carbapenems, β-lactamase inhibitors, monobactams, aminoglycosides, polymyxin analogues and tetracycline) and completely new antibacterial classes (boron-containing antibacterial protein synthesis inhibitors, bis-indoles, outer membrane synthesis inhibitors, antibiotics targeting novel sites of the 50S ribosomal subunit and antimicrobial peptides). However, all of these compounds are still far from being introduced into clinical practice. Therefore, infection control policies and optimization in the use of already existing molecules are still the most effective approaches to reduce the spread of resistance and preserve the activity of antimicrobials.

  1. Gram-negative diabetic foot osteomyelitis: risk factors and clinical presentation.

    Science.gov (United States)

    Aragón-Sánchez, Javier; Lipsky, Benjamin A; Lázaro-Martínez, Jose L

    2013-03-01

    Osteomyelitis frequently complicates infections in the feet of patients with diabetes. Gram-positive cocci, especially Staphylococcus aureus, are the most commonly isolated pathogens, but gram-negative bacteria also cause some cases of diabetic foot osteomyelitis (DFO). These gram-negatives require different antibiotic regimens than those commonly directed at gram-positives. There are, however, few data on factors related to their presence and how they influence the clinical picture. We conducted a retrospective study to determine the variables associated with the isolation of gram-negative bacteria from bone samples in cases of DFO and the clinical presentation of these infections. Among 341 cases of DFO, 150 had a gram-negative isolate (alone or combined with a gram-positive isolate) comprising 44.0% of all patients and 50.8% of those with a positive bone culture. Compared with gram-positive infections, wounds with gram-negative organisms more often had a fetid odor, necrotic tissue, signs of soft tissue infection accompanying osteomyelitis, and clinically severe infection. By multivariate analysis, the predictive variables related to an increased likelihood of isolating gram-negatives from bone samples were glycated hemoglobin gram-negatives had a statistically significantly higher prevalence of leukocytosis and higher white blood cell counts than those without gram-negatives. In conclusion, gram-negative organisms were isolated in nearly half of our cases of DFO and were associated with more severe infections, higher white blood cell counts, lower glycated hemoglobin levels, and wounds of traumatic etiology.

  2. Increased levels of unscheduled DNA synthesis in UV-irradiated human fibroblasts pretreated with sodium butyrate

    International Nuclear Information System (INIS)

    Williams, J.I.; Friedberg, E.C.

    1982-01-01

    Pretreatment of growing normal and xeroderma pigmentosum (XP) human fibroblasts with sodium butyrate at concentrations of 5-20 mM results in increased levels of DNA repair synthesis measured by autoradiography after exposure of the cells to 254 nm UV radiation in the fluence range 0-25 J/m 2 . The phenomenon manifests as an increased extent and an increased initial rate of unscheduled DNA synthesis (UDS). This experimental result is not due to an artifact of autoradiography related to cell size. Xeroderma pigmentosum cells from complementation groups A, C, D and E and XP variant cells all exhibit increases in the levels of UV-induced UDS in response to sodium butyrate proportional to those observed with normal cells. These UDS increases associated with butyrate pretreatment correlate with demonstrable changes in intracellular thymidine pool size and suggest that sodium butyrate enhances uptake of exogenous radiolabeled thymidine during UV-induced repair synthesis by reducing endogenous levels of thymidine. (author)

  3. Gramática Hipertextual

    Directory of Open Access Journals (Sweden)

    Francilaine Munhoz Moraes

    2011-07-01

    Full Text Available No meio digital, a construção da notícia se dá pelo hipertexto. Uma linguagem própria ao suporte consolida-se nas duas últimas décadas. Este artigo se dedica a discutir regularidades linguísticas do discurso jornalístico na web. Se há uma linguagem peculiar ao meio, existe também uma gramática correspondente: a gramática hipertextual. Nesse viés, levantamos traços linguísticos da estrutura sintático-semântica, com base na organização da informação em páginas noticiosas eletrônicas. 

  4. In vitro activity of XF-73, a novel antibacterial agent, against antibiotic-sensitive and -resistant Gram-positive and Gram-negative bacterial species.

    Science.gov (United States)

    Farrell, David J; Robbins, Marion; Rhys-Williams, William; Love, William G

    2010-06-01

    The antibacterial activity of XF-73, a dicationic porphyrin drug, was investigated against a range of Gram-positive and Gram-negative bacteria with known antibiotic resistance profiles, including resistance to cell wall synthesis, protein synthesis, and DNA and RNA synthesis inhibitors as well as cell membrane-active antibiotics. Antibiotic-sensitive strains for each of the bacterial species tested were also included for comparison purposes. XF-73 was active [minimum inhibitory concentration (MIC) 0.25-4 mg/L] against all of the Gram-positive bacteria tested, irrespective of the antibiotic resistance profile of the isolates, suggesting that the mechanism of action of XF-73 is unique compared with the major antibiotic classes. Gram-negative activity was lower (MIC 1 mg/L to > 64 mg/L). Minimum bactericidal concentration data confirmed that the activity of XF-73 was bactericidal. Time-kill kinetics against healthcare-associated and community-associated meticillin-resistant Staphylococcus aureus isolates demonstrated that XF-73 was rapidly bactericidal, with > 5 log(10) kill obtained after 15 min at 2 x MIC, the earliest time point sampled. The post-antibiotic effect (PAE) for XF-73 under conditions where the PAE for vancomycin was 5.4 h. XF-73 represents a novel broad-spectrum Gram-positive antibacterial drug with potentially beneficial characteristics for the treatment and prevention of Gram-positive bacterial infections. 2010. Published by Elsevier B.V.

  5. Inhibition of hyaluronan synthesis reduces versican and fibronectin levels in trabecular meshwork cells.

    Directory of Open Access Journals (Sweden)

    Kate E Keller

    Full Text Available Hyaluronan (HA is a major component of the extracellular matrix (ECM and is synthesized by three HA synthases (HAS. Similarities between the HAS2 knockout mouse and the hdf mutant mouse, which has a mutation in the versican gene, suggest that HA and versican expression may be linked. In this study, the relationship between HA synthesis and levels of versican, fibronectin and several other ECM components in trabecular meshwork cells from the anterior segment of the eye was investigated. HA synthesis was inhibited using 4-methylumbelliferone (4MU, or reduced by RNAi silencing of each individual HAS gene. Quantitative RT-PCR and immunoblotting demonstrated a reduction in mRNA and protein levels of versican and fibronectin. Hyaluronidase treatment also reduced versican and fibronectin levels. These effects could not be reversed by addition of excess glucose or glucosamine or exogenous HA to the culture medium. CD44, tenascin C and fibrillin-1 mRNA levels were reduced by 4MU treatment, but SPARC and CSPG6 mRNA levels were unaffected. Immunostaining of trabecular meshwork tissue after exposure to 4MU showed an altered localization pattern of HA-binding protein, versican and fibronectin. Reduction of versican by RNAi silencing did not affect HA concentration as assessed by ELISA. Together, these data imply that HA concentration affects synthesis of certain ECM components. Since precise regulation of the trabecular meshwork ECM composition and organization is required to maintain the aqueous humor outflow resistance and intraocular pressure homeostasis in the eye, coordinated coupling of HA levels and several of its ECM binding partners should facilitate this process.

  6. Green synthesis of gold nanoparticles for trace level detection of a hazardous pollutant (nitrobenzene) causing Methemoglobinaemia

    Energy Technology Data Exchange (ETDEWEB)

    Emmanuel, R. [Post Graduate and Research Department of Chemistry, Thiagarajar College, Madurai 625009, Tamil Nadu (India); Karuppiah, Chelladurai [Department of Chemical Engineering and Biotechnology, National Taipei University of Technology, Taipei 106, Taiwan, ROC (China); Chen, Shen-Ming, E-mail: smchen78@ms15.hinet.net [Department of Chemical Engineering and Biotechnology, National Taipei University of Technology, Taipei 106, Taiwan, ROC (China); Palanisamy, Selvakumar [Department of Chemical Engineering and Biotechnology, National Taipei University of Technology, Taipei 106, Taiwan, ROC (China); Padmavathy, S. [Department of Zoology and Microbiology, Thiagarajar College, Madurai 625009, Tamil Nadu (India); Prakash, P., E-mail: kmpprakash@gmail.com [Post Graduate and Research Department of Chemistry, Thiagarajar College, Madurai 625009, Tamil Nadu (India)

    2014-08-30

    Graphical abstract: Schematic representation for green synthesis of Au-NPs and its electroreduction of nitrobenzene. - Highlights: • A green synthesis of size controlled Au-NPs from plant extract. • Trace level detection of nitro benzene, a pollutant causing Methemoglobinaemia, at Au-NPs modified electrode. • Achievement of lower LOD and wider linear response. • The proposed sensor exhibits excellent practicality in various water samples. - Abstract: The present study involves a green synthesis of gold nanoparticles (Au-NPs) using Acacia nilotica twig bark extract at room temperature and trace level detection of one of the hazardous materials, viz. nitrobenzene (NB) that causes Methemoglobinaemia. The synthesis protocol demonstrates that the bioreduction of chloroauric acid leads to the formation of Au-NPs within 10 min, suggesting a higher reaction rate than any other chemical methods involved. The obtained Au-NPs have been characterized by UV–vis spectroscopy, X-ray diffraction, transmission electron microscopy, Energy-Dispersive X-ray Spectroscopy and Fourier Transform Infrared Spectroscopy. The electrochemical detection of NB has been investigated at the green synthesized Au-NPs modified glassy carbon electrode by using differential pulse voltammetry (DPV). The Au-NPs modified electrode exhibits excellent reduction ability toward NB compared to unmodified electrode. The developed NB sensor at Au-NPs modified electrode displays a wide linear response from 0.1 to 600 μM with high sensitivity of 1.01 μA μM{sup −1} cm{sup −2} and low limit of detection of 0.016 μM. The modified electrode shows exceptional selectivity in the presence of ions, phenolic and biologically coactive compounds. In addition, the Au-NPs modified electrode exhibits an outstanding recovery results toward NB in various real water samples.

  7. Green synthesis of gold nanoparticles for trace level detection of a hazardous pollutant (nitrobenzene) causing Methemoglobinaemia

    International Nuclear Information System (INIS)

    Emmanuel, R.; Karuppiah, Chelladurai; Chen, Shen-Ming; Palanisamy, Selvakumar; Padmavathy, S.; Prakash, P.

    2014-01-01

    Graphical abstract: Schematic representation for green synthesis of Au-NPs and its electroreduction of nitrobenzene. - Highlights: • A green synthesis of size controlled Au-NPs from plant extract. • Trace level detection of nitro benzene, a pollutant causing Methemoglobinaemia, at Au-NPs modified electrode. • Achievement of lower LOD and wider linear response. • The proposed sensor exhibits excellent practicality in various water samples. - Abstract: The present study involves a green synthesis of gold nanoparticles (Au-NPs) using Acacia nilotica twig bark extract at room temperature and trace level detection of one of the hazardous materials, viz. nitrobenzene (NB) that causes Methemoglobinaemia. The synthesis protocol demonstrates that the bioreduction of chloroauric acid leads to the formation of Au-NPs within 10 min, suggesting a higher reaction rate than any other chemical methods involved. The obtained Au-NPs have been characterized by UV–vis spectroscopy, X-ray diffraction, transmission electron microscopy, Energy-Dispersive X-ray Spectroscopy and Fourier Transform Infrared Spectroscopy. The electrochemical detection of NB has been investigated at the green synthesized Au-NPs modified glassy carbon electrode by using differential pulse voltammetry (DPV). The Au-NPs modified electrode exhibits excellent reduction ability toward NB compared to unmodified electrode. The developed NB sensor at Au-NPs modified electrode displays a wide linear response from 0.1 to 600 μM with high sensitivity of 1.01 μA μM −1 cm −2 and low limit of detection of 0.016 μM. The modified electrode shows exceptional selectivity in the presence of ions, phenolic and biologically coactive compounds. In addition, the Au-NPs modified electrode exhibits an outstanding recovery results toward NB in various real water samples

  8. Gram-positive rods prevailing in teeth with apical periodontitis undergoing root canal treatment.

    Science.gov (United States)

    Chávez de Paz, L E; Molander, A; Dahlén, G

    2004-09-01

    To identify Gram-positive rods from root canals of teeth with apical periodontitis and to examine their associations with other species. Consecutive root canal samples (RCSs) from 139 teeth undergoing root canal treatment were analyzed prospectively for cultivable microbes. Gram-positive rods in the first RCS submitted after chemo-mechanical preparation were categorised to genus level by selective media and gas-liquid chromatography (GLC), and identified to species level by sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE). Associations between organisms were measured by odds ratios (OR). In the first samples submitted a total of 158 Gram-positive rods, 115 Gram-positive cocci, 26 Gram-negative rods and 9 Gram-negative cocci, were identified. At genus levels Gram-positive rods were classified into: Lactobacillus spp. (38%), Olsenella spp. (18%), Propionibacterium spp. (13%), Actinomyces spp. (12%), Bifidobacterium spp. (13%) and Eubacterium spp. (6%). The most frequent species were Olsenella uli, Lactobacillus paracasei and Propionibacterium propionicum. In subsequent samples taken during treatment, Gram-positive rods were also identified, although the number of strains was considerably reduced. Positive associations were observed between members of the genus lactobacilli and Gram-positive cocci (OR>2). Olsenella uli and Lactobacillus spp. predominated over other Gram-positive rods. A possible association exists between Lactobacillus spp. and Gram-positive cocci in root canals of teeth with apical periodontitis receiving treatment.

  9. The effect of intracellular calcium level regulators on the synthesis of pollen tube callose in Oenothera biennis L.

    Directory of Open Access Journals (Sweden)

    Elżbieta Bednarska

    2014-01-01

    Full Text Available It is shown that callose synthesis in the Oenothera biennis pollen tube is regulated by the endogenous Ca2+ level. Calcium antagonists reduced the amount of callose in the wall above the tip of the pollen tube (Verapamil - calcium channels blocker and at the tube tip after stopping tube growth (La3+ - a Ca2+ substitute. Ruthenium red and ionophore A 23187, which raise the Ca 21 level in the cytoplasm, induced callose synthesis at the tip of pollen tube.

  10. Evaluation of the FIR Example using Xilinx Vivado High-Level Synthesis Compiler

    Energy Technology Data Exchange (ETDEWEB)

    Jin, Zheming [Argonne National Lab. (ANL), Argonne, IL (United States); Finkel, Hal [Argonne National Lab. (ANL), Argonne, IL (United States); Yoshii, Kazutomo [Argonne National Lab. (ANL), Argonne, IL (United States); Cappello, Franck [Argonne National Lab. (ANL), Argonne, IL (United States)

    2017-07-28

    Compared to central processing units (CPUs) and graphics processing units (GPUs), field programmable gate arrays (FPGAs) have major advantages in reconfigurability and performance achieved per watt. This development flow has been augmented with high-level synthesis (HLS) flow that can convert programs written in a high-level programming language to Hardware Description Language (HDL). Using high-level programming languages such as C, C++, and OpenCL for FPGA-based development could allow software developers, who have little FPGA knowledge, to take advantage of the FPGA-based application acceleration. This improves developer productivity and makes the FPGA-based acceleration accessible to hardware and software developers. Xilinx Vivado HLS compiler is a high-level synthesis tool that enables C, C++ and System C specification to be directly targeted into Xilinx FPGAs without the need to create RTL manually. The white paper [1] published recently by Xilinx uses a finite impulse response (FIR) example to demonstrate the variable-precision features in the Vivado HLS compiler and the resource and power benefits of converting floating point to fixed point for a design. To get a better understanding of variable-precision features in terms of resource usage and performance, this report presents the experimental results of evaluating the FIR example using Vivado HLS 2017.1 and a Kintex Ultrascale FPGA. In addition, we evaluated the half-precision floating-point data type against the double-precision and single-precision data type and present the detailed results.

  11. Selenoproteins in Archaea and Gram-positive bacteria.

    Science.gov (United States)

    Stock, Tilmann; Rother, Michael

    2009-11-01

    Selenium is an essential trace element for many organisms by serving important catalytic roles in the form of the 21st co-translationally inserted amino acid selenocysteine. It is mostly found in redox-active proteins in members of all three domains of life and analysis of the ever-increasing number of genome sequences has facilitated identification of the encoded selenoproteins. Available data from biochemical, sequence, and structure analyses indicate that Gram-positive bacteria synthesize and incorporate selenocysteine via the same pathway as enterobacteria. However, recent in vivo studies indicate that selenocysteine-decoding is much less stringent in Gram-positive bacteria than in Escherichia coli. For years, knowledge about the pathway of selenocysteine synthesis in Archaea and Eukarya was only fragmentary, but genetic and biochemical studies guided by analysis of genome sequences of Sec-encoding archaea has not only led to the characterization of the pathways but has also shown that they are principally identical. This review summarizes current knowledge about the metabolic pathways of Archaea and Gram-positive bacteria where selenium is involved, about the known selenoproteins, and about the respective pathways employed in selenoprotein synthesis.

  12. Power Constrained High-Level Synthesis of Battery Powered Digital Systems

    DEFF Research Database (Denmark)

    Nielsen, Sune Fallgaard; Madsen, Jan

    2003-01-01

    We present a high-level synthesis algorithm solving the combined scheduling, allocation and binding problem minimizing area under both latency and maximum power per clock-cycle constraints. Our approach eliminates the large power spikes, resulting in an increased battery lifetime, a property...... of utmost importance for battery powered embedded systems. Our approach extends the partial-clique partitioning algorithm by introducing power awareness through a heuristic algorithm which bounds the design space to those of power feasible schedules. We have applied our algorithm on a set of dataflow graphs...

  13. Simultaneous fluorescent gram staining and activity assessment of activated sludge bacteria.

    Science.gov (United States)

    Forster, Scott; Snape, Jason R; Lappin-Scott, Hilary M; Porter, Jonathan

    2002-10-01

    Wastewater treatment is one of the most important commercial biotechnological processes, and yet the component bacterial populations and their associated metabolic activities are poorly understood. The novel fluorescent dye hexidium iodide allows assessment of Gram status by differential absorption through bacterial cell walls. Differentiation between gram-positive and gram-negative wastewater bacteria was achieved after flow cytometric analysis. This study shows that the relative proportions of gram-positive and gram-negative bacterial cells identified by traditional microscopy and hexidium iodide staining were not significantly different. Dual staining of cells for Gram status and activity proved effective in analyzing mixtures of cultured bacteria and wastewater populations. Levels of highly active organisms at two wastewater treatment plants, both gram positive and gram negative, ranged from 1.5% in activated sludge flocs to 16% in the activated sludge fluid. Gram-positive organisms comprised Gram status and activity within activated sludge samples over a 4-day period showed significant differences over time. This method provides a rapid, quantitative measure of Gram status linked with in situ activity within wastewater systems.

  14. Space Efficient Data Structures for N-gram Retrieval

    Directory of Open Access Journals (Sweden)

    Fotios Kounelis

    2017-10-01

    Full Text Available A significant problem in computer science is the management of large data strings and a great number of works dealing with the specific problem has been published in the scientific literature. In this article, we use a technique to store efficiently biological sequences, making use of data structures like suffix trees and inverted files and also employing techniques like n-grams, in order to improve previous constructions. In our attempt, we drastically reduce the space needed to store the inverted indexes, by representing the substrings that appear more frequently in a more compact inverted index. Our technique is based on n-gram indexing, providing us the extra advantage of indexing sequences that cannot be separated in words. Moreover, our technique combines classical one level with two-level n-gram inverted file indexing. Our results suggest that the new proposed algorithm can compress the data more efficiently than previous attempts.

  15. Fed levels of amino acids are required for the somatotropin-induced increase in muscle protein synthesis.

    Science.gov (United States)

    Wilson, Fiona A; Suryawan, Agus; Orellana, Renán A; Nguyen, Hanh V; Jeyapalan, Asumthia S; Gazzaneo, Maria C; Davis, Teresa A

    2008-10-01

    Chronic somatotropin (pST) treatment in pigs increases muscle protein synthesis and circulating insulin, a known promoter of protein synthesis. Previously, we showed that the pST-mediated rise in insulin could not account for the pST-induced increase in muscle protein synthesis when amino acids were maintained at fasting levels. This study aimed to determine whether the pST-induced increase in insulin promotes skeletal muscle protein synthesis when amino acids are provided at fed levels and whether the response is associated with enhanced translation initiation factor activation. Growing pigs were treated with pST (0 or 180 microg x kg(-1) x day(-1)) for 7 days, and then pancreatic-glucose-amino acid clamps were performed. Amino acids were raised to fed levels in the presence of either fasted or fed insulin concentrations; glucose was maintained at fasting throughout. Muscle protein synthesis was increased by pST treatment and by amino acids (with or without insulin) (P<0.001). In pST-treated pigs, fed, but not fasting, amino acid concentrations further increased muscle protein synthesis rates irrespective of insulin level (P<0.02). Fed amino acids, with or without raised insulin concentrations, increased the phosphorylation of S6 kinase (S6K1) and eukaryotic initiation factor (eIF) 4E-binding protein 1 (4EBP1), decreased inactive 4EBP1.eIF4E complex association, and increased active eIF4E.eIF4G complex formation (P<0.02). pST treatment did not alter translation initiation factor activation. We conclude that the pST-induced stimulation of muscle protein synthesis requires fed amino acid levels, but not fed insulin levels. However, under the current conditions, the response to amino acids is not mediated by the activation of translation initiation factors that regulate mRNA binding to the ribosomal complex.

  16. Higher order structure in the 3'-minor domain of small subunit ribosomal RNAs from a gram negative bacterium, a gram positive bacterium and a eukaryote

    DEFF Research Database (Denmark)

    Douthwaite, S; Christensen, A; Garrett, R A

    1983-01-01

    of additional higher order structure in the renatured free RNA. It can be concluded that a high level of conservation of higher order structure has occurred during the evolution of the gram negative and gram positive eubacteria and the eukaryote in both the double helical regions and the "unstructured" regions...

  17. Gram staining apparatus for space station applications

    Science.gov (United States)

    Molina, T. C.; Brown, H. D.; Irbe, R. M.; Pierson, D. L.

    1990-01-01

    A self-contained, portable Gram staining apparatus (GSA) has been developed for use in the microgravity environment on board the Space Station Freedom. Accuracy and reproducibility of this apparatus compared with the conventional Gram staining method were evaluated by using gram-negative and gram-positive controls and different species of bacteria grown in pure cultures. A subsequent study was designed to assess the performance of the GSA with actual specimens. A set of 60 human and environmental specimens was evaluated with the GSA and the conventional Gram staining procedure. Data obtained from these studies indicated that the GSA will provide the Gram staining capability needed for the microgravity environment of space.

  18. Veillonella, Firmicutes: Microbes disguised as Gram negatives

    DEFF Research Database (Denmark)

    Vesth, Tammi Camilla; Ozen, Asli; Andersen, Sandra Christine

    2013-01-01

    Negativicutes, including the genus Veillonella, stain Gram negative. Veillonella are among the most abundant organisms of the oral and intestinal microflora of animals and humans, in spite of being strict anaerobes. In this work, the genomes of 24 Negativicutes, including eight Veillonella spp., are compared......, with the exception of a shared LPS biosynthesis pathway. The clade within the class Negativicutes to which the genus Veillonella belongs exhibits unique properties, most of which are in common with Gram-positives and some with Gram negatives. They are only distantly related to Clostridia, but are even less closely...... related to Gram-negative species. Though the Negativicutes stain Gram-negative and possess two membranes, the genome and proteome analysis presented here confirm their place within the (mainly) Gram positive phylum of the Firmicutes. Further studies are required to unveil the evolutionary history...

  19. Transformation of gram positive bacteria by sonoporation

    Science.gov (United States)

    Yang, Yunfeng; Li, Yongchao

    2014-03-11

    The present invention provides a sonoporation-based method that can be universally applied for delivery of compounds into Gram positive bacteria. Gram positive bacteria which can be transformed by sonoporation include, for example, Bacillus, Streptococcus, Acetobacterium, and Clostridium. Compounds which can be delivered into Gram positive bacteria via sonoporation include nucleic acids (DNA or RNA), proteins, lipids, carbohydrates, viruses, small organic and inorganic molecules, and nano-particles.

  20. High-Level Synthesis of DSP Applications Using Adaptive Negative Cycle Detection

    Directory of Open Access Journals (Sweden)

    Nitin Chandrachoodan

    2002-09-01

    Full Text Available The problem of detecting negative weight cycles in a graph is examined in the context of the dynamic graph structures that arise in the process of high level synthesis (HLS. The concept of adaptive negative cycle detection is introduced, in which a graph changes over time and negative cycle detection needs to be done periodically, but not necessarily after every individual change. We present an algorithm for this problem, based on a novel extension of the well-known Bellman-Ford algorithm that allows us to adapt existing cycle information to the modified graph, and show by experiments that our algorithm significantly outperforms previous incremental approaches for dynamic graphs. In terms of applications, the adaptive technique leads to a very fast implementation of Lawlers algorithm for the computation of the maximum cycle mean (MCM of a graph, especially for a certain form of sparse graph. Such sparseness often occurs in practical circuits and systems, as demonstrated, for example, by the ISCAS 89/93 benchmarks. The application of the adaptive technique to design-space exploration (synthesis is also demonstrated by developing automated search techniques for scheduling iterative data-flow graphs.

  1. New transposon tools tailored for metabolic engineering of Gram-negative microbial cell factories

    Directory of Open Access Journals (Sweden)

    Esteban eMartínez-García

    2014-10-01

    Full Text Available Re-programming microorganisms to modify their existing functions and/or to bestow bacteria with entirely new-to-Nature tasks have largely relied so far on specialized molecular biology tools. Such endeavors are not only relevant in the burgeoning metabolic engineering arena, but also instrumental to explore the functioning of complex regulatory networks from a fundamental point of view. À la carte modification of bacterial genomes thus calls for novel tools to make genetic manipulations easier. We propose the use of a series of new broad-host-range mini-Tn5 vectors, termed pBAMDs, for the delivery of gene(s into the chromosome of Gram-negative bacteria and for generating saturated mutagenesis libraries in gene function studies. These delivery vectors endow the user with the possibility of easy cloning and subsequent insertion of functional cargoes with three different antibiotic resistance markers (kanamycin, streptomycin, and gentamicin. After validating the pBAMD vectors in the environmental bacterium Pseudomonas putida KT2440, their use was also illustrated by inserting the entire poly(3-hydroxybutyrate (PHB synthesis pathway from Cupriavidus necator in the chromosome of a phosphotransacetylase mutant of Escherichia coli. PHB is a completely biodegradable polyester with a number of industrial applications that make it attractive as a potential replacement of oil-based plastics. The non-selective nature of chromosomal insertions of the biosynthetic genes was evidenced by a large landscape of PHB synthesis levels in independent clones. One clone was selected and further characterized as a microbial cell factory for PHB accumulation, and it achieved polymer accumulation levels comparable to those of a plasmid-bearing recombinant. Taken together, our results demonstrate that the new mini-Tn5 vectors can be used to confer interesting phenotypes in Gram-negative bacteria that would be very difficult to engineer through direct manipulation of the

  2. New Transposon Tools Tailored for Metabolic Engineering of Gram-Negative Microbial Cell Factories

    International Nuclear Information System (INIS)

    Martínez-García, Esteban; Aparicio, Tomás; Lorenzo, Víctor de; Nikel, Pablo I.

    2014-01-01

    Re-programming microorganisms to modify their existing functions and/or to bestow bacteria with entirely new-to-Nature tasks have largely relied so far on specialized molecular biology tools. Such endeavors are not only relevant in the burgeoning metabolic engineering arena but also instrumental to explore the functioning of complex regulatory networks from a fundamental point of view. À la carte modification of bacterial genomes thus calls for novel tools to make genetic manipulations easier. We propose the use of a series of new broad-host-range mini-Tn5-vectors, termed pBAMDs, for the delivery of gene(s) into the chromosome of Gram-negative bacteria and for generating saturated mutagenesis libraries in gene function studies. These delivery vectors endow the user with the possibility of easy cloning and subsequent insertion of functional cargoes with three different antibiotic-resistance markers (kanamycin, streptomycin, and gentamicin). After validating the pBAMD vectors in the environmental bacterium Pseudomonas putida KT2440, their use was also illustrated by inserting the entire poly(3-hydroxybutyrate) (PHB) synthesis pathway from Cupriavidus necator in the chromosome of a phosphotransacetylase mutant of Escherichia coli. PHB is a completely biodegradable polyester with a number of industrial applications that make it attractive as a potential replacement of oil-based plastics. The non-selective nature of chromosomal insertions of the biosynthetic genes was evidenced by a large landscape of PHB synthesis levels in independent clones. One clone was selected and further characterized as a microbial cell factory for PHB accumulation, and it achieved polymer accumulation levels comparable to those of a plasmid-bearing recombinant. Taken together, our results demonstrate that the new mini-Tn5-vectors can be used to confer interesting phenotypes in Gram-negative bacteria that would be very difficult to engineer through direct manipulation of the structural genes.

  3. New Transposon Tools Tailored for Metabolic Engineering of Gram-Negative Microbial Cell Factories

    Energy Technology Data Exchange (ETDEWEB)

    Martínez-García, Esteban; Aparicio, Tomás; Lorenzo, Víctor de; Nikel, Pablo I., E-mail: pablo.nikel@cnb.csic.es [Systems and Synthetic Biology Program, Centro Nacional de Biotecnología (CNB-CSIC), Madrid (Spain)

    2014-10-28

    Re-programming microorganisms to modify their existing functions and/or to bestow bacteria with entirely new-to-Nature tasks have largely relied so far on specialized molecular biology tools. Such endeavors are not only relevant in the burgeoning metabolic engineering arena but also instrumental to explore the functioning of complex regulatory networks from a fundamental point of view. À la carte modification of bacterial genomes thus calls for novel tools to make genetic manipulations easier. We propose the use of a series of new broad-host-range mini-Tn5-vectors, termed pBAMDs, for the delivery of gene(s) into the chromosome of Gram-negative bacteria and for generating saturated mutagenesis libraries in gene function studies. These delivery vectors endow the user with the possibility of easy cloning and subsequent insertion of functional cargoes with three different antibiotic-resistance markers (kanamycin, streptomycin, and gentamicin). After validating the pBAMD vectors in the environmental bacterium Pseudomonas putida KT2440, their use was also illustrated by inserting the entire poly(3-hydroxybutyrate) (PHB) synthesis pathway from Cupriavidus necator in the chromosome of a phosphotransacetylase mutant of Escherichia coli. PHB is a completely biodegradable polyester with a number of industrial applications that make it attractive as a potential replacement of oil-based plastics. The non-selective nature of chromosomal insertions of the biosynthetic genes was evidenced by a large landscape of PHB synthesis levels in independent clones. One clone was selected and further characterized as a microbial cell factory for PHB accumulation, and it achieved polymer accumulation levels comparable to those of a plasmid-bearing recombinant. Taken together, our results demonstrate that the new mini-Tn5-vectors can be used to confer interesting phenotypes in Gram-negative bacteria that would be very difficult to engineer through direct manipulation of the structural genes.

  4. ‘PROTEIN SYNTHESIS GAME’: UTILIZING GAME-BASED APPROACH FOR IMPROVING COMMUNICATIVE SKILLS IN A-LEVELS BIOLOGY CLASS

    Directory of Open Access Journals (Sweden)

    Mohd Adlan Ramly

    2017-12-01

    Full Text Available This experimental paper seeks to elucidate the usage of the card game ‘Protein Synthesis Game’ as a student’s learning tool in studying the Biology topic of protein synthesis during an A-Level course. A total of 24 experimental students in 3 induced groups and 24 controlled students in controlled groups were involved in the experiment which began with a pretest on the topic of Protein Synthesis, followed by the experimentation, and ended with a post-test administered after the incubation period. Results indicate that students have better facilitative communicative engagement in learning protein synthesis when playing the game as compared to studying the topic from a book. The data suggests that such communicative engagement may lead to a successful meaningful learning on the students’ part.

  5. Cellular reprogramming by gram-positive bacterial components: a review.

    LENUS (Irish Health Repository)

    Buckley, Julliette M

    2012-02-03

    LPS tolerance has been the focus of extensive scientific and clinical research over the last several decades in an attempt to elucidate the sequence of changes that occur at a molecular level in tolerized cells. Tolerance to components of gram-positive bacterial cell walls such as bacterial lipoprotein and lipoteichoic acid is a much lesser studied, although equally important, phenomenon. This review will focus on cellular reprogramming by gram-positive bacterial components and examines the alterations in cell surface receptor expression, changes in intracellular signaling, gene expression and cytokine production, and the phenomenon of cross-tolerance.

  6. Cytokine profile in severe gram-positive and gram-negative abdominal sepsis

    Science.gov (United States)

    Surbatovic, Maja; Popovic, Nada; Vojvodic, Danilo; Milosevic, Ivan; Acimovic, Gordana; Stojicic, Milan; Veljovic, Milic; Jevdjic, Jasna; Djordjevic, Dragan; Radakovic, Sonja

    2015-01-01

    Sepsis is a principal cause of death in critical care units worldwide and consumes considerable healthcare resources. The aim of our study was to determine whether the early cytokine profile can discriminate between Gram-positive and Gram-negative bacteraemia (GPB and GNB, respectively) and to assess the prognostic value regarding outcome in critically ill patients with severe abdominal sepsis. The outcome measure was hospital mortality. Blood samples were obtained from 165 adult patients with confirmed severe abdominal sepsis. Levels of the proinflammatory mediators TNF-α, IL-8, IL-12 and IFN-γ and the anti-inflammatory mediators IL-1ra, IL-4, IL-10 and TGF-β1 were determined and correlated with the nature of the bacteria isolated from the blood culture and outcome. The cytokine profile in our study indicated that the TNF-α levels were 2-fold, IL-8 were 3.3-fold, IFN-γ were 13-fold, IL-1ra were 1.05-fold, IL-4 were 1.4-fold and IL-10 were 1.83-fold higher in the GNB group compared with the GPB group. The TNF-α levels were 4.7-fold, IL-8 were 4.6-fold, IL-1ra were 1.5-fold and IL-10 were 3.3-fold higher in the non-survivors compared with the survivors. PMID:26079127

  7. Increased cellular levels of spermidine or spermine are required for optimal DNA synthesis in lymphocytes activated by concanavalin A.

    Science.gov (United States)

    Fillingame, R H; Jorstad, C M; Morris, D R

    1975-01-01

    There are large increases in cellular levels of the polyamines spermidine and spermine in lymphocytes induced to transform by concanavalin A. The anti-leukemic agent methylglyoxal bis(guanylhydrazone) (MGBG) blocks synthesis of these polyamines by inhibiting S-adenosylmethionine decarboxylase. Previous results showed that when cells are activated in the presence of MGBG the synthesis and processing of RNA, as well as protein synthesis, proceed as in the absence of the drug. In contrast, the incorporation of [methyl-3H]thymidine into DNA and the rate of entry of the cells into mitosis are inhibited by 60% in the presence of MGBG. Several experiments suggest that MGBG inhibits cell proliferation by directly blocking polyamine synthesis and not by an unrelated pharmacological effect: (1) the inhibitory action of MGBG is reversed by exogenously added spermidine or spermine; (2) inhibition of DNA synthesis by MGBG shows the same dose-response curve as does inhibition of spermidine and spermine synthesis; and (3) if MGBG is added to cells which have been allowed to accumulate their maximum complement of polyamines, there is no inhibition of thymidine incorporation. MGBG-treated and control cultures initiate DNA synthesis at the same time and show the same percentage of labeled cells by autoradiography. Therefore, it appears that in the absence of increased cellular levels of polyamines, lymphocytes progress normally from G0 through G1 and into S-phase. Furthermore, these experiments suggest that the increased levels of spermidine and spermine generally seen in rapidly proliferating eukaryotic systems are necessary for enhanced rates of DNA replication. PMID:1060087

  8. n-Gram-Based Text Compression

    Science.gov (United States)

    Duong, Hieu N.; Snasel, Vaclav

    2016-01-01

    We propose an efficient method for compressing Vietnamese text using n-gram dictionaries. It has a significant compression ratio in comparison with those of state-of-the-art methods on the same dataset. Given a text, first, the proposed method splits it into n-grams and then encodes them based on n-gram dictionaries. In the encoding phase, we use a sliding window with a size that ranges from bigram to five grams to obtain the best encoding stream. Each n-gram is encoded by two to four bytes accordingly based on its corresponding n-gram dictionary. We collected 2.5 GB text corpus from some Vietnamese news agencies to build n-gram dictionaries from unigram to five grams and achieve dictionaries with a size of 12 GB in total. In order to evaluate our method, we collected a testing set of 10 different text files with different sizes. The experimental results indicate that our method achieves compression ratio around 90% and outperforms state-of-the-art methods. PMID:27965708

  9. n-Gram-Based Text Compression

    Directory of Open Access Journals (Sweden)

    Vu H. Nguyen

    2016-01-01

    Full Text Available We propose an efficient method for compressing Vietnamese text using n-gram dictionaries. It has a significant compression ratio in comparison with those of state-of-the-art methods on the same dataset. Given a text, first, the proposed method splits it into n-grams and then encodes them based on n-gram dictionaries. In the encoding phase, we use a sliding window with a size that ranges from bigram to five grams to obtain the best encoding stream. Each n-gram is encoded by two to four bytes accordingly based on its corresponding n-gram dictionary. We collected 2.5 GB text corpus from some Vietnamese news agencies to build n-gram dictionaries from unigram to five grams and achieve dictionaries with a size of 12 GB in total. In order to evaluate our method, we collected a testing set of 10 different text files with different sizes. The experimental results indicate that our method achieves compression ratio around 90% and outperforms state-of-the-art methods.

  10. A hardware acceleration based on high-level synthesis approach for glucose-insulin analysis

    Science.gov (United States)

    Daud, Nur Atikah Mohd; Mahmud, Farhanahani; Jabbar, Muhamad Hairol

    2017-01-01

    In this paper, the research is focusing on Type 1 Diabetes Mellitus (T1DM). Since this disease requires a full attention on the blood glucose concentration with the help of insulin injection, it is important to have a tool that able to predict that level when consume a certain amount of carbohydrate during meal time. Therefore, to make it realizable, a Hovorka model which is aiming towards T1DM is chosen in this research. A high-level language is chosen that is C++ to construct the mathematical model of the Hovorka model. Later, this constructed code is converted into intellectual property (IP) which is also known as a hardware accelerator by using of high-level synthesis (HLS) approach which able to improve in terms of design and performance for glucose-insulin analysis tool later as will be explained further in this paper. This is the first step in this research before implementing the design into system-on-chip (SoC) to achieve a high-performance system for the glucose-insulin analysis tool.

  11. Bi-Level Integrated System Synthesis (BLISS) for Concurrent and Distributed Processing

    Science.gov (United States)

    Sobieszczanski-Sobieski, Jaroslaw; Altus, Troy D.; Phillips, Matthew; Sandusky, Robert

    2002-01-01

    The paper introduces a new version of the Bi-Level Integrated System Synthesis (BLISS) methods intended for optimization of engineering systems conducted by distributed specialty groups working concurrently and using a multiprocessor computing environment. The method decomposes the overall optimization task into subtasks associated with disciplines or subsystems where the local design variables are numerous and a single, system-level optimization whose design variables are relatively few. The subtasks are fully autonomous as to their inner operations and decision making. Their purpose is to eliminate the local design variables and generate a wide spectrum of feasible designs whose behavior is represented by Response Surfaces to be accessed by a system-level optimization. It is shown that, if the problem is convex, the solution of the decomposed problem is the same as that obtained without decomposition. A simplified example of an aircraft design shows the method working as intended. The paper includes a discussion of the method merits and demerits and recommendations for further research.

  12. A Synthetic Dual Drug Sideromycin Induces Gram-Negative Bacteria To Commit Suicide with a Gram-Positive Antibiotic.

    Science.gov (United States)

    Liu, Rui; Miller, Patricia A; Vakulenko, Sergei B; Stewart, Nichole K; Boggess, William C; Miller, Marvin J

    2018-05-10

    Many antibiotics lack activity against Gram-negative bacteria because they cannot permeate the outer membrane or suffer from efflux and, in the case of β-lactams, are degraded by β-lactamases. Herein, we describe the synthesis and studies of a dual drug conjugate (1) of a siderophore linked to a cephalosporin with an attached oxazolidinone. The cephalosporin component of 1 is rapidly hydrolyzed by purified ADC-1 β-lactamase to release the oxazolidinone. Conjugate 1 is active against clinical isolates of Acinetobacter baumannii as well as strains producing large amounts of ADC-1 β-lactamase. Overall, the results are consistent with siderophore-mediated active uptake, inherent activity of the delivered dual drug, and in the presence of β-lactamases, intracellular release of the oxazolidinone upon cleavage of the cephalosporin to allow the freed oxazolidinone to inactivate its target. The ultimate result demonstrates that Gram-positive oxazolidinone antibiotics can be made to be effective against Gram-negative bacteria by β-lactamase triggered release.

  13. Gram-positive and gram-negative bacteria induce different patterns of cytokine production in human mononuclear cells irrespective of taxonomic relatedness.

    Science.gov (United States)

    Skovbjerg, Susann; Martner, Anna; Hynsjö, Lars; Hessle, Christina; Olsen, Ingar; Dewhirst, Floyd E; Tham, Wilhelm; Wold, Agnes E

    2010-01-01

    Upon bacterial stimulation, tissue macrophages produce a variety of cytokines that orchestrate the immune response that clears the infection. We have shown that Gram-positives induce higher levels of interleukin-12 (IL-12), interferon-gamma (IFN-gamma), and tumor necrosis factor (TNF) from human peripheral blood mononuclear cells (PBMCs) than do Gram-negatives, which instead induce more of IL-6, IL-8, and IL-10. Here, we study whether these patterns follows or crosses taxonomic borders. PBMCs from blood donors were incubated with UV-inactivated bacteria representing 37 species from five phyla. IL-12, TNF, IL-1beta, IL-6, IL-8, and IL-10 were measured in the supernatants after 24 h and IFN-gamma after 5 days. Irrespective of phylogenetic position, Gram-positive bacteria induced much more IL-12 (nine times more on average) and IFN-gamma (seven times), more TNF (three times), and slightly more IL-1beta (1.5 times) than did Gram-negatives, which instead induced more IL-6 (1.5 times), IL-8 (1.9 times), and IL-10 (3.3 times) than did Gram-positives. A notable exception was the Gram-positive Listeria monocytogenes, which induced very little IL-12, IFN-gamma, and TNF. The results confirm the fundamental difference in innate immune responses to Gram-positive and Gram-negative bacteria, which crosses taxonomic borders and probably reflects differences in cell wall structure.

  14. Synthesis of the day 'Sane dwelling and radon: how to act at the local level?' - Experiments and perspectives

    International Nuclear Information System (INIS)

    Bernier, Sandrine

    2012-01-01

    This document proposes a synthesis of contributions which addressed the knowledge about radon and regulation regarding radon, the management of the risk related to the presence of radon in dwellings and the environment, at the international level (in Switzerland, in Canada); locally implemented experiments (around Montbeliard, in Aix-en-Provence, in the Finistere district) with measurements and public information are discussed

  15. Synthesis of Cyclic Polymers and Characterization of Their Diffusive Motion in the Melt State at the Single Molecule Level

    KAUST Repository

    Habuchi, Satoshi; Yamamoto, Takuya; Tezuka, Yasuyuki

    2016-01-01

    We demonstrate a method for the synthesis of cyclic polymers and a protocol for characterizing their diffusive motion in a melt state at the single molecule level. An electrostatic self-assembly and covalent fixation (ESA-CF) process is used

  16. Multicenter Assessment of Gram Stain Error Rates.

    Science.gov (United States)

    Samuel, Linoj P; Balada-Llasat, Joan-Miquel; Harrington, Amanda; Cavagnolo, Robert

    2016-06-01

    Gram stains remain the cornerstone of diagnostic testing in the microbiology laboratory for the guidance of empirical treatment prior to availability of culture results. Incorrectly interpreted Gram stains may adversely impact patient care, and yet there are no comprehensive studies that have evaluated the reliability of the technique and there are no established standards for performance. In this study, clinical microbiology laboratories at four major tertiary medical care centers evaluated Gram stain error rates across all nonblood specimen types by using standardized criteria. The study focused on several factors that primarily contribute to errors in the process, including poor specimen quality, smear preparation, and interpretation of the smears. The number of specimens during the evaluation period ranged from 976 to 1,864 specimens per site, and there were a total of 6,115 specimens. Gram stain results were discrepant from culture for 5% of all specimens. Fifty-eight percent of discrepant results were specimens with no organisms reported on Gram stain but significant growth on culture, while 42% of discrepant results had reported organisms on Gram stain that were not recovered in culture. Upon review of available slides, 24% (63/263) of discrepant results were due to reader error, which varied significantly based on site (9% to 45%). The Gram stain error rate also varied between sites, ranging from 0.4% to 2.7%. The data demonstrate a significant variability between laboratories in Gram stain performance and affirm the need for ongoing quality assessment by laboratories. Standardized monitoring of Gram stains is an essential quality control tool for laboratories and is necessary for the establishment of a quality benchmark across laboratories. Copyright © 2016, American Society for Microbiology. All Rights Reserved.

  17. Induction of vitellogenin synthesis by estrogen in avian liver: relationship between level of vitellogenin mRNA and vitellogenin synthesis.

    Science.gov (United States)

    Mullinix, K P; Wetekam, W; Deeley, R G; Gordon, J I; Meyers, M; Kent, K A; Goldberger, R F

    1976-01-01

    We have investigated the estrogen-mediated induction of vitellogenin synthesis in rooster liver. We compared the concentrations of vitellogenin messenger RNA (mRNA) in the liver with the concentrations of vitellogenin in the sera of roosters that had recieved various treatments with estrogen. We found no vitellogenin mRNA in the livers of the unstimulated roosters. An initial injection of estrogen was attended by de novo synthesis of vitellogenin mRNA in the liver and accumulation of vitellogenin in the serum. When vitellogenin was no longer present in the serum or liver (the "post-estrogen-serum-negative" state), the liver was found to contain appreciable amounts of vitellogenin mRNA. This mRNA was of the same size as that found in the liver of the rooster actively synthesizing vitellogenin in response to estrogen. Whereas vitellogenin mRNA was in large polysomes in the livers of the roosters actively synthesizing vitellogenin, the vitellogenin mRNA in the liver of the post-estrogen-serum-negative rooster was not associated with polysomes. The possible relevance of these findings to the fact that the rooster responds differently to a primary stimulation with estrogen than to subsequent stimulations is discussed. PMID:1064017

  18. FPGA-Based Channel Coding Architectures for 5G Wireless Using High-Level Synthesis

    Directory of Open Access Journals (Sweden)

    Swapnil Mhaske

    2017-01-01

    Full Text Available We propose strategies to achieve a high-throughput FPGA architecture for quasi-cyclic low-density parity-check codes based on circulant-1 identity matrix construction. By splitting the node processing operation in the min-sum approximation algorithm, we achieve pipelining in the layered decoding schedule without utilizing additional hardware resources. High-level synthesis compilation is used to design and develop the architecture on the FPGA hardware platform. To validate this architecture, an IEEE 802.11n compliant 608 Mb/s decoder is implemented on the Xilinx Kintex-7 FPGA using the LabVIEW FPGA Compiler in the LabVIEW Communication System Design Suite. Architecture scalability was leveraged to accomplish a 2.48 Gb/s decoder on a single Xilinx Kintex-7 FPGA. Further, we present rapidly prototyped experimentation of an IEEE 802.16 compliant hybrid automatic repeat request system based on the efficient decoder architecture developed. In spite of the mixed nature of data processing—digital signal processing and finite-state machines—LabVIEW FPGA Compiler significantly reduced time to explore the system parameter space and to optimize in terms of error performance and resource utilization. A 4x improvement in the system throughput, relative to a CPU-based implementation, was achieved to measure the error-rate performance of the system over large, realistic data sets using accelerated, in-hardware simulation.

  19. Embedded Lattice and Properties of Gram Matrix

    Directory of Open Access Journals (Sweden)

    Futa Yuichi

    2017-03-01

    Full Text Available In this article, we formalize in Mizar [14] the definition of embedding of lattice and its properties. We formally define an inner product on an embedded module. We also formalize properties of Gram matrix. We formally prove that an inverse of Gram matrix for a rational lattice exists. Lattice of Z-module is necessary for lattice problems, LLL (Lenstra, Lenstra and Lov´asz base reduction algorithm [16] and cryptographic systems with lattice [17].

  20. Veillonella, Firmicutes: Microbes disguised as Gram negatives.

    Science.gov (United States)

    Vesth, Tammi; Ozen, Aslı; Andersen, Sandra C; Kaas, Rolf Sommer; Lukjancenko, Oksana; Bohlin, Jon; Nookaew, Intawat; Wassenaar, Trudy M; Ussery, David W

    2013-12-20

    The Firmicutes represent a major component of the intestinal microflora. The intestinal Firmicutes are a large, diverse group of organisms, many of which are poorly characterized due to their anaerobic growth requirements. Although most Firmicutes are Gram positive, members of the class Negativicutes, including the genus Veillonella, stain Gram negative. Veillonella are among the most abundant organisms of the oral and intestinal microflora of animals and humans, in spite of being strict anaerobes. In this work, the genomes of 24 Negativicutes, including eight Veillonella spp., are compared to 20 other Firmicutes genomes; a further 101 prokaryotic genomes were included, covering 26 phyla. Thus a total of 145 prokaryotic genomes were analyzed by various methods to investigate the apparent conflict of the Veillonella Gram stain and their taxonomic position within the Firmicutes. Comparison of the genome sequences confirms that the Negativicutes are distantly related to Clostridium spp., based on 16S rRNA, complete genomic DNA sequences, and a consensus tree based on conserved proteins. The genus Veillonella is relatively homogeneous: inter-genus pair-wise comparison identifies at least 1,350 shared proteins, although less than half of these are found in any given Clostridium genome. Only 27 proteins are found conserved in all analyzed prokaryote genomes. Veillonella has distinct metabolic properties, and significant similarities to genomes of Proteobacteria are not detected, with the exception of a shared LPS biosynthesis pathway. The clade within the class Negativicutes to which the genus Veillonella belongs exhibits unique properties, most of which are in common with Gram-positives and some with Gram negatives. They are only distantly related to Clostridia, but are even less closely related to Gram-negative species. Though the Negativicutes stain Gram-negative and possess two membranes, the genome and proteome analysis presented here confirm their place within the

  1. An optimized staining technique for the detection of Gram positive and Gram negative bacteria within tissue.

    Science.gov (United States)

    Becerra, Sandra C; Roy, Daniel C; Sanchez, Carlos J; Christy, Robert J; Burmeister, David M

    2016-04-12

    Bacterial infections are a common clinical problem in both acute and chronic wounds. With growing concerns over antibiotic resistance, treatment of bacterial infections should only occur after positive diagnosis. Currently, diagnosis is delayed due to lengthy culturing methods which may also fail to identify the presence of bacteria. While newer costly bacterial identification methods are being explored, a simple and inexpensive diagnostic tool would aid in immediate and accurate treatments for bacterial infections. Histologically, hematoxylin and eosin (H&E) and Gram stains have been employed, but are far from optimal when analyzing tissue samples due to non-specific staining. The goal of the current study was to develop a modification of the Gram stain that enhances the contrast between bacteria and host tissue. A modified Gram stain was developed and tested as an alternative to Gram stain that improves the contrast between Gram positive bacteria, Gram negative bacteria and host tissue. Initially, clinically relevant strains of Pseudomonas aeruginosa and Staphylococcus aureus were visualized in vitro and in biopsies of infected, porcine burns using routine Gram stain, and immunohistochemistry techniques involving bacterial strain-specific fluorescent antibodies as validation tools. H&E and Gram stain of serial biopsy sections were then compared to a modification of the Gram stain incorporating a counterstain that highlights collagen found in tissue. The modified Gram stain clearly identified both Gram positive and Gram negative bacteria, and when compared to H&E or Gram stain alone provided excellent contrast between bacteria and non-viable burn eschar. Moreover, when applied to surgical biopsies from patients that underwent burn debridement this technique was able to clearly detect bacterial morphology within host tissue. We describe a modification of the Gram stain that provides improved contrast of Gram positive and Gram negative microorganisms within host

  2. Gram-negative, but not Gram-positive, bacteria elicit strong PGE2 production in human monocytes.

    Science.gov (United States)

    Hessle, Christina C; Andersson, Bengt; Wold, Agnes E

    2003-12-01

    Gram-positive and Gram-negative bacteria induce different cytokine patterns in human mononuclear cells. We have seen that Gram-positives preferentially induce IL-12 and TNF-alpha, whereas Gram-negatives induce more IL-10, IL-6, and IL-8. In this study, we compared the capacity of these two groups of bacteria to induce PGE2. Monocytes stimulated with Gram-negative bacterial species induced much more PGE2 than did Gram-positive bacteria (5600 +/- 330 vs. 1700 +/- 670 pg/mL, p Gram-positive and Gram-negative bacteria. We suggest that Gram-positive and Gram-negative bacteria may stimulate different innate effector functions; Gram-positive bacteria promoting cell-mediated effector functions whereas Gram-negative bacteria inducing mediators inhibiting the same.

  3. The comparison of pyrosequencing molecular Gram stain, culture, and conventional Gram stain for diagnosing orthopaedic infections.

    Science.gov (United States)

    Kobayashi, Naomi; Bauer, Thomas W; Tuohy, Marion J; Lieberman, Isador H; Krebs, Viktor; Togawa, Daisuke; Fujishiro, Takaaki; Procop, Gary W

    2006-08-01

    We have developed a combined real-time PCR and pyrosequencing assay that successfully differentiated the vast majority of gram-positive and gram-negative bacteria when bacterial isolates were tested. The purpose of this study was to evaluate this assay on clinical specimens obtained from orthopedic surgeries, and to prospectively compare the results of "molecular Gram stain" with culture and conventional direct Gram stain. Forty-five surgical specimens were obtained from patients who underwent orthopedic surgery procedures. The DNA was extracted and a set of broad-range PCR primers that targeted a part of the 16S rDNA gene was used for pan-bacterial PCR. The amplicons were submitted for pyrosequencing and the resulting molecular Gram stain characteristics were recorded. Culture and direct Gram staining were performed using standard methods for all cases. Surgical specimens were reviewed histologically for all cases that had a discrepancy between culture and molecular results. There was an 86.7% (39/45) agreement between the traditional and molecular methods. In 12/14 (85.7%) culture-proven cases of bacterial infection, molecular Gram stain characteristics were in agreement with the culture results, while the conventional Gram stain result was in agreement only for five cases (35.7%). In the 31 culture negative cases, 27 cases were also PCR negative, whereas 4 were PCR positive. Three of these were characterized as gram negative and one as gram positive by this molecular method. Molecular determination of the Gram stain characteristics of bacteria that cause orthopedic infections may be achieved, in most instances, by this method. Further studies are necessary to understand the clinical importance of PCR-positive/culture-negative results.

  4. Gram staining for the treatment of peritonsillar abscess.

    Science.gov (United States)

    Takenaka, Yukinori; Takeda, Kazuya; Yoshii, Tadashi; Hashimoto, Michiko; Inohara, Hidenori

    2012-01-01

    Objective. To examine whether Gram staining can influence the choice of antibiotic for the treatment of peritonsillar abscess. Methods. Between 2005 and 2009, a total of 57 cases of peritonsillar abscess were analyzed with regard to cultured bacteria and Gram staining. Results. Only aerobes were cultured in 16% of cases, and only anaerobes were cultured in 51% of cases. Mixed growth of aerobes and anaerobes was observed in 21% of cases. The cultured bacteria were mainly aerobic Streptococcus, anaerobic Gram-positive cocci, and anaerobic Gram-negative rods. Phagocytosis of bacteria on Gram staining was observed in 9 cases. The bacteria cultured from these cases were aerobic Streptococcus, anaerobic Gram-positive cocci, and anaerobic Gram-negative rods. The sensitivity of Gram staining for the Gram-positive cocci and Gram-negative rods was 90% and 64%, respectively. The specificity of Gram staining for the Gram-positive cocci and Gram-negative rods was 62% and 76%, respectively. Most of the Gram-positive cocci were sensitive to penicillin, but some of anaerobic Gram-negative rods were resistant to penicillin. Conclusion. When Gram staining shows only Gram-positive cocci, penicillin is the treatment of choice. In other cases, antibiotics effective for the penicillin-resistant organisms should be used.

  5. Should gram stains have a role in diagnosing hip arthroplasty infections?

    Science.gov (United States)

    Johnson, Aaron J; Zywiel, Michael G; Stroh, D Alex; Marker, David R; Mont, Michael A

    2010-09-01

    The utility of Gram stains in diagnosing periprosthetic infections following total hip arthroplasty has recently been questioned. Several studies report low sensitivity of the test, and its poor ability to either confirm or rule out infection in patients undergoing revision total hip arthroplasty. Despite this, many institutions including that of the senior author continue to perform Gram stains during revision total hip arthroplasty. We assessed the sensitivity, specificity, accuracy, and positive and negative predictive values of Gram stains from surgical-site samplings taken from procedures on patients with both infected and aseptic revision total hip arthroplasties. A review was performed on patients who underwent revision total hip arthroplasty between 2000 and 2007. Eighty-two Gram stains were performed on patients who had infected total hip arthroplasties and underwent revision procedures. Additionally, of the 410 revision total hip arthroplasties performed on patients who were confirmed infection-free, 120 Gram stains were performed. Patients were diagnosed as infected using multiple criteria at the time of surgery. Sensitivity, specificity, positive and negative predictive values, and accuracy were calculated from these Gram stain results. The Gram stain demonstrated a sensitivity and specificity of 9.8% and 100%, respectively. In this series, the Gram stain had a negative predictive value of 62%, a positive predictive value of 100%, and an accuracy of 63%. Gram stains obtained from surgical-site samples had poor sensitivity and poor negative predictive value. Based on these findings, as well as those of other authors, we believe that Gram stains should no longer be considered for diagnosing infections in revision total hip arthroplasty. Level III, diagnostic study. See Guidelines for Authors for a complete description of levels of evidence.

  6. Protamine-induced permeabilization of cell envelopes of gram-positive and gram-negative bacteria

    DEFF Research Database (Denmark)

    Johansen, Charlotte; Verheul, A.; Gram, Lone

    1997-01-01

    carboxyfluorescein and ATP after 2 to 5 min. Maximum antibacterial activity was reached at alkaline pH and in the absence of divalent cations. The efficient permeabilization of cell envelopes of both gram-positive and gram-negative bacteria suggests that protamine causes a general disruption of the cell envelope...

  7. The use of street-level bureaucracy theory in health policy analysis in low- and middle-income countries: a meta-ethnographic synthesis.

    Science.gov (United States)

    Erasmus, Ermin

    2014-12-01

    This article presents a synthesis of studies that explicitly use the theory of street-level bureaucracy to illuminate health policy implementation in low- and middle-income countries. Street-level bureaucrats are frontline workers in bureaucracies, e.g. nurses, who regularly interact directly with citizens in discharging their policy implementation duties and who have some discretion over which services are offered, how services are offered and the benefits and sanctions allocated to citizens. This synthesis seeks to achieve the dual objectives of, first, reflecting on how street-level bureaucracy theory has been used in the literature and, second, providing an example of the application of the synthesis methodology of meta-ethnography to the health policy analysis literature. The article begins by outlining meta-ethnography and providing more information on the papers on which the synthesis is based. This is followed by a detailed account of how the synthesis was achieved and by an articulation of the synthesis. It then concludes with thoughts and questions on the value and relevance of the synthesis, the experience of conducting the synthesis and the partial way in which street-level bureaucracy theory has been used in the literature examined. Published by Oxford University Press in association with The London School of Hygiene and Tropical Medicine © The Author 2014; all rights reserved.

  8. Synthesis

    International Nuclear Information System (INIS)

    Voinis, Sylvie; Lalieux, Philippe; Thury, Marc; Horseman, Steve

    2001-01-01

    To prevent radioactive contamination and undue exposure to the public, it is required that long-lived and/or high-level radioactive wastes be isolated from the human environment for a very long period of time. For the purpose of isolating such wastes, the basic concept of deep disposal is to place packaged waste in a geological formation such as clay. One of main functions of the geological formation is to isolate waste from moving groundwater, thus minimising lixiviation of waste and advective radionuclide transport and, hence the amount of radionuclides that could reach the human environment. Improving our understanding of processes that might affect the containment properties of the geological barrier can reduce uncertainties about the performance of the repository. In particular, during the stepwise development of the research programme, it is important to clarify if fractures that might be induced by the excavation of the underground facilities might have a significant impact on the radiological safety of a repository in a host formation such as clay. In this framework, the self- healing properties of argillaceous media - often quoted as one of the advantages of such host formations - play a major role, notably in reducing the long-term impacts of such induced fracturing. Twenty-six participants representing several national waste management organisations, regulatory authorities, government agencies and the academic community from the OECD member countries and the EC took part in the Topical Session. The session was mainly aimed at exchanging information on: The general point of view on self-healing from geomechanical and geochemical experts; The approaches that are or will be followed by the various organisations in order to deal with the self-healing. The geological settings covered in the presentations related to the whole range of argillaceous media relevant to the disposal of radioactive wastes, including poorly indurated clays and indurated mud

  9. Determining synthesis rates of individual proteins in zebrafish (Danio rerio) with low levels of a stable isotope labelled amino acid.

    Science.gov (United States)

    Geary, Bethany; Magee, Kieran; Cash, Phillip; Young, Iain S; Whitfield, Phillip D; Doherty, Mary K

    2016-05-01

    The zebrafish is a powerful model organism for the analysis of human cardiovascular development and disease. Understanding these processes at the protein level not only requires changes in protein concentration to be determined but also the rate at which these changes occur on a protein-by-protein basis. The ability to measure protein synthesis and degradation rates on a proteome-wide scale, using stable isotope labelling in conjunction with mass spectrometry is now a well-established experimental approach. With the advent of more selective and sensitive mass spectrometers, it is possible to accurately measure lower levels of stable isotope incorporation, even when sample is limited. In order to challenge the sensitivity of this approach, we successfully determined the synthesis rates of over 600 proteins from the cardiac muscle of the zebrafish using a diet where either 30% or 50% of the L-leucine was replaced with a stable isotope labelled analogue ([(2) H7 ]L-leucine]. It was possible to extract sufficient protein from individual zebrafish hearts to determine the incorporation rate of the label into hundreds of proteins simultaneously, with the two labelling regimens showing a good correlation of synthesis rates. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  10. Synthesis of Cyclic Polymers and Characterization of Their Diffusive Motion in the Melt State at the Single Molecule Level

    KAUST Repository

    Habuchi, Satoshi

    2016-09-26

    We demonstrate a method for the synthesis of cyclic polymers and a protocol for characterizing their diffusive motion in a melt state at the single molecule level. An electrostatic self-assembly and covalent fixation (ESA-CF) process is used for the synthesis of the cyclic poly(tetrahydrofuran) (poly(THF)). The diffusive motion of individual cyclic polymer chains in a melt state is visualized using single molecule fluorescence imaging by incorporating a fluorophore unit in the cyclic chains. The diffusive motion of the chains is quantitatively characterized by means of a combination of mean-squared displacement (MSD) analysis and a cumulative distribution function (CDF) analysis. The cyclic polymer exhibits multiple-mode diffusion which is distinct from its linear counterpart. The results demonstrate that the diffusional heterogeneity of polymers that is often hidden behind ensemble averaging can be revealed by the efficient synthesis of the cyclic polymers using the ESA-CF process and the quantitative analysis of the diffusive motion at the single molecule level using the MSD and CDF analyses.

  11. Experimental synthesis of crystalline matrices based on Ce, Ba, Sr zirconates for immobilization of high-level radioactive actinides

    International Nuclear Information System (INIS)

    Anderson, E.B.; Burakov, B.E.; Vasiliev, V.G.; Starchenko, V.A.

    1993-01-01

    In geological disposal of high-level radioactive waste the main storage barriers, in the first place the matrix containing radionuclides, must remain undestructible over a long period of time. Very high requirements are imposed for the matrices from the viewpoint of their chemical stability and mechanical strength. Zirconates may be classified among compounds potentially suitable for the creation of crystalline matrices incorporating radionuclides in their structure. The paper considers results of laboratory experiments on the synthesis of crystalline matrices based on various zirconates by the methods of gas-static and axial pressing. Problems are discussed concerning the crystalline matrix industrial synthesis technology developed at the Radium Institute. One of the most promising directions in solving the problem of high-level waste (HLW) removal from the sphere of human activity is disposal in deep geological formations. The realization of this direction envisages creation of multibarrier compositions. Special attention is paid to the technology for the synthesis of the first, the most crucial, engineering barrier: the matrix into which radionuclides are incorporated. It is assumed that crystalline compounds best satisfy all the requirements as the most thermodynamically stable

  12. Effects of Fuel to Synthesis of CaTiO3 by Solution Combustion Synthesis for High-Level Nuclear Waste Ceramics.

    Science.gov (United States)

    Jung, Choong-Hwan; Kim, Yeon-Ku; Han, Young-Min; Lee, Sang-Jin

    2016-02-01

    A solution combustion process for the synthesis of perovskite (CaTiO3) powders is described. Perovskite is one of the crystalline host matrics for the disposal of high-level radioactive wastes (HLW) because it immobilizes Sr and Lns elements by forming solid solutions. Solution combustion synthesis, which is a self-sustaining oxi-reduction reaction between nitrate and organic fuel, the exothermic reaction, and the heat evolved convert the precursors into their corresponding oxide products above 1100 degrees C in air. To investigate the effects of amino acid on the combustion reaction, various types of fuels were used; a glycine, amine and carboxylic ligand mixture. Sr, La and Gd-nitrate with equivalent amounts of up to 20% of CaTiO3 were mixed with Ca and Ti nitrate and amino acid. X-ray diffraction analysis, SEM and TEM were conducted to confirm the formed phases and morphologies. While powders with an uncontrolled shape are obtained through a general oxide-route process, Ca(Sr, Lns)TiO3 powders with micro-sized soft agglomerates consisting of nano-sized primary particles can be prepared using this method.

  13. Revisiting the gram-negative lipoprotein paradigm

    Science.gov (United States)

    The processing of lipoproteins (lpps) in Gram-negative bacteria is generally considered to be an essential pathway. Mature lipoproteins in these bacteria are triacylated, with the final fatty acid addition performed by Lnt, an apolipoprotein n-acyltransferase. The mature lipoproteins are then sorted...

  14. Gram staining with an automatic machine.

    Science.gov (United States)

    Felek, S; Arslan, A

    1999-01-01

    This study was undertaken to develop a new Gram-staining machine controlled by a micro-controller and to investigate the quality of slides that were stained in the machine. The machine was designed and produced by the authors. It uses standard 220 V AC. Staining, washing, and drying periods are controlled by a timer built in the micro-controller. A software was made that contains a certain algorithm and time intervals for the staining mode. One-hundred and forty smears were prepared from Escherichia coli, Staphylococcus aureus, Neisseria sp., blood culture, trypticase soy broth, direct pus and sputum smears for comparison studies. Half of the slides in each group were stained with the machine, the other half by hand and then examined by four different microbiologists. Machine-stained slides had a higher clarity and less debris than the hand-stained slides (p stained slides, some Gram-positive organisms showed poor Gram-positive staining features (p Gram staining with the automatic machine increases the staining quality and helps to decrease the work load in a busy diagnostic laboratory.

  15. Synthesis of Axial Power Distribution Using 5-Level Ex-core Detector in a Core Protection System

    International Nuclear Information System (INIS)

    Koo, Bon-Seung; Lee, Chung-Chan; Zee, Sung-Quun

    2007-01-01

    In ABB-CE digital plants, Core Protection Calculator System (CPCS) is used for a core protection based on several online measured system parameters including 3- level safety grade ex-core detector signals. The CPCS provides four independent channels for the departure from a nucleate boiling ratio (DNBR) and local power density (LPD) trip signals to the reactor protection system. Each channel consists of a core protection calculator (CPC) and a control element assembly calculator (CEAC). The cubic spline synthesis technique has been used in online calculations of the core axial power distributions using 3-level ex-core detector signals in CPC. The pre-determined cubic spline function sets are used depending on the characteristics of the ex-core detector responses. But this method shows large power distribution errors for the extremely skewed axial shapes due to restrictive function sets and an incorrect SAM value. Especially thus situation is worse at a higher burnup. To solve these problems, the cubic spline function sets are improved and it is demonstrated that the axial power shapes can be synthesized more accurately with the new function sets than those of a conventional CPC. In this paper, synthesis of an axial power distribution using a 5-level ex-core detector is described and the axial power distributions are compared between 3-level and 5-level ex-core detector systems

  16. Revisiting the Gram-negative lipoprotein paradigm.

    Science.gov (United States)

    LoVullo, Eric D; Wright, Lori F; Isabella, Vincent; Huntley, Jason F; Pavelka, Martin S

    2015-05-01

    The processing of lipoproteins (Lpps) in Gram-negative bacteria is generally considered an essential pathway. Mature lipoproteins in these bacteria are triacylated, with the final fatty acid addition performed by Lnt, an apolipoprotein N-acyltransferase. The mature lipoproteins are then sorted by the Lol system, with most Lpps inserted into the outer membrane (OM). We demonstrate here that the lnt gene is not essential to the Gram-negative pathogen Francisella tularensis subsp. tularensis strain Schu or to the live vaccine strain LVS. An LVS Δlnt mutant has a small-colony phenotype on sucrose medium and increased susceptibility to globomycin and rifampin. We provide data indicating that the OM lipoprotein Tul4A (LpnA) is diacylated but that it, and its paralog Tul4B (LpnB), still sort to the OM in the Δlnt mutant. We present a model in which the Lol sorting pathway of Francisella has a modified ABC transporter system that is capable of recognizing and sorting both triacylated and diacylated lipoproteins, and we show that this modified system is present in many other Gram-negative bacteria. We examined this model using Neisseria gonorrhoeae, which has the same Lol architecture as that of Francisella, and found that the lnt gene is not essential in this organism. This work suggests that Gram-negative bacteria fall into two groups, one in which full lipoprotein processing is essential and one in which the final acylation step is not essential, potentially due to the ability of the Lol sorting pathway in these bacteria to sort immature apolipoproteins to the OM. This paper describes the novel finding that the final stage in lipoprotein processing (normally considered an essential process) is not required by Francisella tularensis or Neisseria gonorrhoeae. The paper provides a potential reason for this and shows that it may be widespread in other Gram-negative bacteria. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

  17. Timing of initiation of macronuclear DNA synthesis is set during the preceding cell cycle in Paramecium tetraurelia: analysis of the effects of abrupt changes in nutrient level

    International Nuclear Information System (INIS)

    Ching, A.S.L.; Berger, J.D.

    1986-01-01

    In many eukaryotic organisms, initiation of DNA synthesis is associated with a major control point within the cell cycle and reflects the commitment of the cell to the DNA replication-division portion of the cell cycle. In paramecium, the timing of DNA synthesis initiation is established prior to fission during the preceding cell cycle. DNA synthesis normally starts at 0.25 in the cell cycle. When dividing cells are subjected to abrupt nutrient shift-up by transfer from a chemostat culture to medium with excess food, or shift-down from a well-fed culture to exhausted medium, DNA synthesis initiation in the post-shift cell cycle occurs at 0.25 of the parental cell cycle and not at either 0.25 in the post-shift cell cycle or at 0.25 in the equilibrium cell cycle produced under the post-shift conditions. The long delay prior to initiation of DNA synthesis following nutritional shift-up is not a consequence of continued slow growth because the rate of protein synthesis increases rapidly to the normal level after shift-up. Analysis of the relation between increase in cell mass and initiation of DNA synthesis following nutritional shifts indicates that increase in cell mass, per se, is neither a necessary nor a sufficient condition for initiation of DNA synthesis, in spite of the strong association between accumulation of cell mass and initiation of DNA synthesis in cells growing under steady-state conditions

  18. Chlorophyll Synthase under Epigenetic Surveillance Is Critical for Vitamin E Synthesis, and Altered Expression Affects Tocopherol Levels in Arabidopsis.

    Science.gov (United States)

    Zhang, Chunyu; Zhang, Wei; Ren, Guodong; Li, Delin; Cahoon, Rebecca E; Chen, Ming; Zhou, Yongming; Yu, Bin; Cahoon, Edgar B

    2015-08-01

    Chlorophyll synthase catalyzes the final step in chlorophyll biosynthesis: the esterification of chlorophyllide with either geranylgeranyl diphosphate or phytyl diphosphate (PDP). Recent studies have pointed to the involvement of chlorophyll-linked reduction of geranylgeranyl by geranylgeranyl reductase as a major pathway for the synthesis of the PDP precursor of tocopherols. This indirect pathway of PDP synthesis suggests a key role of chlorophyll synthase in tocopherol production to generate the geranylgeranyl-chlorophyll substrate for geranylgeranyl reductase. In this study, contributions of chlorophyll synthase to tocopherol formation in Arabidopsis (Arabidopsis thaliana) were explored by disrupting and altering expression of the corresponding gene CHLOROPHYLL SYNTHASE (CHLSYN; At3g51820). Leaves from the homozygous chlysyn1-1 null mutant were nearly devoid of tocopherols, whereas seeds contained only approximately 25% of wild-type tocopherol levels. Leaves of RNA interference lines with partial suppression of CHLSYN displayed marked reductions in chlorophyll but up to a 2-fold increase in tocopherol concentrations. Cauliflower mosaic virus35S-mediated overexpression of CHLSYN unexpectedly caused a cosuppression phenotype at high frequencies accompanied by strongly reduced chlorophyll content and increased tocopherol levels. This phenotype and the associated detection of CHLSYN-derived small interfering RNAs were reversed with CHLSYN overexpression in rna-directed rna polymerase6 (rdr6), which is defective in RNA-dependent RNA polymerase6, a key enzyme in sense transgene-induced small interfering RNA production. CHLSYN overexpression in rdr6 had little effect on chlorophyll content but resulted in up to a 30% reduction in tocopherol levels in leaves. These findings show that altered CHLSYN expression impacts tocopherol levels and also, show a strong epigenetic surveillance of CHLSYN to control chlorophyll and tocopherol synthesis. © 2015 American Society of

  19. Role of laser fluence in protein synthesis of cultured DRG neurons following low-level laser irradiation

    Science.gov (United States)

    Zheng, Liqin; Qiu, Caimin; Wang, Yuhua; Zeng, Yixiu; Yang, Hongqin; Zhang, Yanding; Xie, Shusen

    2014-11-01

    Low-level lasers have been used to relieve pain in clinical for many years. But the mechanism is not fully clear. In animal models, nitric oxide (NO) has been reported involving in the transmission and modulation of nociceptive signals. So the objective of this study was to establish whether low-level laser with different fluence could stimulate the production of nitric oxide synthese (NOS), which produces NO in cultured primary dorsal root ganglion neurons (DRG neurons). The primary DRG neurons were isolated from healthy Sprague Dawley rats (8-12 weeks of age) and spread on 35 mm culture dishes specially used for confocal microscopy. 24 hours after spreading, cells were irradiated with 658 nm laser for two consecutive days at the energy density of 20, 40, 60 and 80 mJ·cm-2 respectively. Control groups were not exposed to the laser, but were kept under the same conditions as the irradiated ones. The synthesis of NOS after laser irradiation was detected by immunofluorescence assay, and the changes of NOS were evaluated using confocal microscopy and Image J software. The results showed that all the laser fluence could promote the production of NOS in DRG neurons, especially the 60 mJ·cm-2 . These results demonstrated that low-level laser irradiation could modify protein synthesis in a dose- or fluence- dependent manner, and indicated that low-level laser irradiation might achieve the analgesic effect through modulation of NO production.

  20. Gram negative wound infection in hospitalised adult burn patients--systematic review and metanalysis-.

    Science.gov (United States)

    Azzopardi, Ernest A; Azzopardi, Elayne; Camilleri, Liberato; Villapalos, Jorge; Boyce, Dean E; Dziewulski, Peter; Dickson, William A; Whitaker, Iain S

    2014-01-01

    Gram negative infection is a major determinant of morbidity and survival. Traditional teaching suggests that burn wound infections in different centres are caused by differing sets of causative organisms. This study established whether Gram-negative burn wound isolates associated to clinical wound infection differ between burn centres. Studies investigating adult hospitalised patients (2000-2010) were critically appraised and qualified to a levels of evidence hierarchy. The contribution of bacterial pathogen type, and burn centre to the variance in standardised incidence of Gram-negative burn wound infection was analysed using two-way analysis of variance. Pseudomonas aeruginosa, Klebsiella pneumoniae, Acinetobacter baumanni, Enterobacter spp., Proteus spp. and Escherichia coli emerged as the commonest Gram-negative burn wound pathogens. Individual pathogens' incidence did not differ significantly between burn centres (F (4, 20) = 1.1, p = 0.3797; r2 = 9.84). Gram-negative infections predominate in burn surgery. This study is the first to establish that burn wound infections do not differ significantly between burn centres. It is the first study to report the pathogens responsible for the majority of Gram-negative infections in these patients. Whilst burn wound infection is not exclusive to these bacteria, it is hoped that reporting the presence of this group of common Gram-negative "target organisms" facilitate clinical practice and target research towards a defined clinical demand.

  1. Gram negative wound infection in hospitalised adult burn patients--systematic review and metanalysis-.

    Directory of Open Access Journals (Sweden)

    Ernest A Azzopardi

    Full Text Available BACKGROUND: Gram negative infection is a major determinant of morbidity and survival. Traditional teaching suggests that burn wound infections in different centres are caused by differing sets of causative organisms. This study established whether Gram-negative burn wound isolates associated to clinical wound infection differ between burn centres. METHODS: Studies investigating adult hospitalised patients (2000-2010 were critically appraised and qualified to a levels of evidence hierarchy. The contribution of bacterial pathogen type, and burn centre to the variance in standardised incidence of Gram-negative burn wound infection was analysed using two-way analysis of variance. PRIMARY FINDINGS: Pseudomonas aeruginosa, Klebsiella pneumoniae, Acinetobacter baumanni, Enterobacter spp., Proteus spp. and Escherichia coli emerged as the commonest Gram-negative burn wound pathogens. Individual pathogens' incidence did not differ significantly between burn centres (F (4, 20 = 1.1, p = 0.3797; r2 = 9.84. INTERPRETATION: Gram-negative infections predominate in burn surgery. This study is the first to establish that burn wound infections do not differ significantly between burn centres. It is the first study to report the pathogens responsible for the majority of Gram-negative infections in these patients. Whilst burn wound infection is not exclusive to these bacteria, it is hoped that reporting the presence of this group of common Gram-negative "target organisms" facilitate clinical practice and target research towards a defined clinical demand.

  2. Mid-infrared spectroscopic assessment of nanotoxicity in gram-negative vs. gram-positive bacteria.

    Science.gov (United States)

    Heys, Kelly A; Riding, Matthew J; Strong, Rebecca J; Shore, Richard F; Pereira, M Glória; Jones, Kevin C; Semple, Kirk T; Martin, Francis L

    2014-03-07

    Nanoparticles appear to induce toxic effects through a variety of mechanisms including generation of reactive oxygen species (ROS), physical contact with the cell membrane and indirect catalysis due to remnants from manufacture. The development and subsequent increasing usage of nanomaterials has highlighted a growing need to characterize and assess the toxicity of nanoparticles, particularly those that may have detrimental health effects such as carbon-based nanomaterials (CBNs). Due to interactions of nanoparticles with some reagents, many traditional toxicity tests are unsuitable for use with CBNs. Infrared (IR) spectroscopy is a non-destructive, high throughput technique, which is unhindered by such problems. We explored the application of IR spectroscopy to investigate the effects of CBNs on Gram-negative (Pseudomonas fluorescens) and Gram-positive (Mycobacterium vanbaalenii PYR-1) bacteria. Two types of IR spectroscopy were compared: attenuated total reflection Fourier-transform infrared (ATR-FTIR) and synchrotron radiation-based FTIR (SR-FTIR) spectroscopy. This showed that Gram-positive and Gram-negative bacteria exhibit differing alterations when exposed to CBNs. Gram-positive bacteria appear more resistant to these agents and this may be due to the protection afforded by their more sturdy cell wall. Markers of exposure also vary according to Gram status; Amide II was consistently altered in Gram-negative bacteria and carbohydrate altered in Gram-positive bacteria. ATR-FTIR and SR-FTIR spectroscopy could both be applied to extract biochemical alterations induced by each CBN that were consistent across the two bacterial species; these may represent potential biomarkers of nanoparticle-induced alterations. Vibrational spectroscopy approaches may provide a novel means of fingerprinting the effects of CBNs in target cells.

  3. Variations in the Produce-Associated Microbiota and the Occurrence Frequency of Extended-Spectrum Beta-Lactamase Gram-Negative Bacteria Result in Different Level of Ingestion Risks

    KAUST Repository

    Bokhari, Osama

    2016-04-01

    A monitoring effort that spanned across one and a half years was conducted to examine three types of produce-associated microbiota. Produce type was determined to be the predominant factor affecting the microbial communities. Other significant factors that resulted in differences in the microbial populations were the origin and sampling date. Specifically, produce-associated microbiota among lettuce and tomatoes clustered based on the sampling period. Through molecular and cultivation-based approaches, sporadic presence of extended spectrum beta-lactamase (ESBL)-positive Klebsiella pneumoniae and Acinetobacter baumannii was detected on lettuce and cucumbers during certain periods of sampling. Quantitative microbial risk assessment denoted varying levels of ingestion risks associated with different types of produce. In particular, the risks arising from ESBL-positive K. pneumoniae in the lettuce were higher than the acceptable annual risk of 10-4. Commonly used approaches to clean and wash the produce were insufficient in removing majority of the produce-associated microbiota. More invasive cleaning approaches or thorough cooking of the produce would be required to mitigate the associated risks. Most of the current reports of ESBL-positive bacterial isolates were identified in nosocomial environment. However, the carriage of such drug-resistant bacteria in food that is consumed daily

  4. DETECTING LOW-LEVEL SYNTHESIS IMPURITIES IN MODIFIED PHOSPHOROTHIOATE OLIGONUCLEOTIDES USING LIQUID CHROMATOGRAPHY – HIGH RESOLUTION MASS SPECTROMETRY

    Science.gov (United States)

    Nikcevic, Irena; Wyrzykiewicz, Tadeusz K.; Limbach, Patrick A.

    2010-01-01

    Summary An LC-MS method based on the use of high resolution Fourier transform ion cyclotron resonance mass spectrometry (FTIRCMS) for profiling oligonucleotides synthesis impurities is described. Oligonucleotide phosphorothioatediesters (phosphorothioate oligonucleotides), in which one of the non-bridging oxygen atoms at each phosphorus center is replaced by a sulfur atom, are now one of the most popular oligonucleotide modifications due to their ease of chemical synthesis and advantageous pharmacokinetic properties. Despite significant progress in the solid-phase oligomerization chemistry used in the manufacturing of these oligonucleotides, multiple classes of low-level impurities always accompany synthetic oligonucleotides. Liquid chromatography-mass spectrometry has emerged as a powerful technique for the identification of these synthesis impurities. However, impurity profiling, where the entire complement of low-level synthetic impurities is identified in a single analysis, is more challenging. Here we present an LC-MS method based the use of high resolution-mass spectrometry, specifically Fourier transform ion cyclotron resonance mass spectrometry (FTIRCMS or FTMS). The optimal LC-FTMS conditions, including the stationary phase and mobile phases for the separation and identification of phosphorothioate oligonucleotides, were found. The characteristics of FTMS enable charge state determination from single m/z values of low-level impurities. Charge state information then enables more accurate modeling of the detected isotopic distribution for identification of the chemical composition of the detected impurity. Using this approach, a number of phosphorothioate impurities can be detected by LC-FTMS including failure sequences carrying 3′-terminal phosphate monoester and 3′-terminal phosphorothioate monoester, incomplete backbone sulfurization and desulfurization products, high molecular weight impurities, and chloral, isobutyryl, and N3 (2-cyanoethyl) adducts

  5. Gram positive and Gram negative bacteria differ in their sensitivity to cold plasma

    Science.gov (United States)

    Mai-Prochnow, Anne; Clauson, Maryse; Hong, Jungmi; Murphy, Anthony B.

    2016-12-01

    Cold atmospheric-pressure plasma (CAP) is a relatively new method being investigated for antimicrobial activity. However, the exact mode of action is still being explored. Here we report that CAP efficacy is directly correlated to bacterial cell wall thickness in several species. Biofilms of Gram positive Bacillus subtilis, possessing a 55.4 nm cell wall, showed the highest resistance to CAP, with less than one log10 reduction after 10 min treatment. In contrast, biofilms of Gram negative Pseudomonas aeruginosa, possessing only a 2.4 nm cell wall, were almost completely eradicated using the same treatment conditions. Planktonic cultures of Gram negative Pseudomonas libanensis also had a higher log10 reduction than Gram positive Staphylococcus epidermidis. Mixed species biofilms of P. aeruginosa and S. epidermidis showed a similar trend of Gram positive bacteria being more resistant to CAP treatment. However, when grown in co-culture, Gram negative P. aeruginosa was more resistant to CAP overall than as a mono-species biofilm. Emission spectra indicated OH and O, capable of structural cell wall bond breakage, were present in the plasma. This study indicates that cell wall thickness correlates with CAP inactivation times of bacteria, but cell membranes and biofilm matrix are also likely to play a role.

  6. Antiadhesion agents against Gram-positive pathogens.

    Science.gov (United States)

    Cascioferro, Stella; Cusimano, Maria Grazia; Schillaci, Domenico

    2014-01-01

    A fundamental step of Gram-positive pathogenesis is the bacterial adhesion to the host tissue involving interaction between bacterial surface molecules and host ligands. This review is focused on antivirulence compounds that target Gram-positive adhesins and on their potential development as therapeutic agents alternative or complementary to conventional antibiotics in the contrast of pathogens. In particular, compounds that target the sortase A, wall theicoic acid inhibitors, carbohydrates able to bind bacterial proteins and proteins capable of influencing the bacterial adhesion, were described. We further discuss the advantages and disadvantages of this strategy in the development of novel antimicrobials and the future perspective of this research field still at its first steps.

  7. Evaluation of plasma H2S levels and H2S synthesis in streptozotocin induced Type-2 diabetes-an experimental study based on Swietenia macrophylla seeds

    Directory of Open Access Journals (Sweden)

    Moumita Dutta

    2014-05-01

    Conclusions: Although considering a small sample size, it can conclude that the fasting blood glucose levels are inversely related to plasma H2S levels as well as H2S synthesis activity in plasma and the extract of S. macrophylla is associated with increased plasma H2S levels with effective lowering of blood glucose in streptozotocin induced diabetic rats.

  8. Níveis de silicato de cálcio e magnésio na produção das gramídeas Marandu e Tanzânia cultivadas em um Neossolo Quartzarênico Level of calcium and magnesium silicate in the yield of Marandu grass and Tanzania grass cultivated in one Quartzsandy Neosoil

    Directory of Open Access Journals (Sweden)

    Caio Augustus Fortes

    2008-02-01

    Full Text Available O estudo foi conduzido em casa-de-vegetação do Departamento de Ciência do Solo da Universidade Federal de Lavras, Lavras-MG, com o objetivo de avaliar o efeito da correção da acidez do solo, por meio da aplicação de níveis de silicato de Ca e Mg, na produção das gramíneas Brachiaria brizantha cv. Marandu e Panicum maximum cv. Tanzânia-1 cultivadas em solo Neossolo Quartzarênico ortic. O delineamento experimental utilizado foi blocos ao acaso, em esquema fatorial 2 x 5 com quatro repetições, sendo duas forrageiras e cinco níveis de saturação por bases (V% original, 40, 60, 80 e 100%. Cada unidade experimental correspondeu a um vaso sem furos, com capacidade para 4,0 dm³ de solo, totalizando 40 vasos. Foram avaliadas as produções de MS por corte (PMS e total (PTMS, a altura e o número de perfilhos. Não houve variação entre as gramíneas em altura de perfilhos. O Tanzânia foi superior ao Marandu em PMS e número de perfilhos. Houve aumento linear na PMS, PTMS e altura de perfilhos. Conclui-se que ambas as gramíneas responderam de forma positiva à elevação dos níveis de V%, em PMS, até 54,8%. O Tanzânia produziu mais MS em relação ao Marandu.This study was conducted in a greenhouse of the Soil Science Department at Universidade Federal de Lavras, Lavras-MG, with the purpose of evaluating the effect of the soil correction acidity, by the application of Ca and Mg silicate levels, in the production of grasses Brachiaria brizantha cv. Marandu and Panicum maximum cv. Tanzânia-1 cultivated in Quartzsandy Neosoil ortic. The experimental design was a randomized complete block, in 2 x 5 factorial scheme with four replicates, being two forages and five levels of base saturation (BS%; (original BS, 40, 60, 80 and 100%. Each experimental unit corresponded to a pot with a capacity of 4.0 dm³ of soil, totalizing 40 pots. The dry matter yield (DMY for cut and total (TDMY, height and number of tillers were evaluated. There were

  9. Pleural effusion adenosine deaminase: a candidate biomarker to discriminate between Gram-negative and Gram-positive bacterial infections of the pleural space

    Directory of Open Access Journals (Sweden)

    Ruolin Li

    2016-05-01

    Full Text Available OBJECTIVES: Delay in the treatment of pleural infection may contribute to its high mortality. In this retrospective study, we aimed to evaluate the diagnostic accuracy of pleural adenosine deaminase in discrimination between Gram-negative and Gram-positive bacterial infections of the pleural space prior to selecting antibiotics. METHODS: A total of 76 patients were enrolled and grouped into subgroups according to Gram staining: 1 patients with Gram-negative bacterial infections, aged 53.2±18.6 years old, of whom 44.7% had empyemas and 2 patients with Gram-positive bacterial infections, aged 53.5±21.5 years old, of whom 63.1% had empyemas. The pleural effusion was sampled by thoracocentesis and then sent for adenosine deaminase testing, biochemical testing and microbiological culture. The Mann-Whitney U test was used to examine the differences in adenosine deaminase levels between the groups. Correlations between adenosine deaminase and specified variables were also quantified using Spearman’s correlation coefficient. Moreover, receiver operator characteristic analysis was performed to evaluate the diagnostic accuracy of pleural effusion adenosine deaminase. RESULTS: Mean pleural adenosine deaminase levels differed significantly between Gram-negative and Gram-positive bacterial infections of the pleural space (191.8±32.1 U/L vs 81.0±16.9 U/L, p<0.01. The area under the receiver operator characteristic curve was 0.689 (95% confidence interval: 0.570, 0.792, p<0.01 at the cutoff value of 86 U/L. Additionally, pleural adenosine deaminase had a sensitivity of 63.2% (46.0-78.2%; a specificity of 73.7% (56.9-86.6%; positive and negative likelihood ratios of 2.18 and 0.50, respectively; and positive and negative predictive values of 70.6% and 66.7%, respectively. CONCLUSIONS: Pleural effusion adenosine deaminase is a helpful alternative biomarker for early and quick discrimination of Gram-negative from Gram-positive bacterial infections of the

  10. Alternate gram staining technique using a fluorescent lectin.

    Science.gov (United States)

    Sizemore, R K; Caldwell, J J; Kendrick, A S

    1990-01-01

    Fluorescence-labeled wheat germ agglutinin binds specifically to N-acetylglucosamine in the outer peptidoglycan layer of gram-positive bacteria. The peptidoglycan layer of gram-negative bacteria is covered by a membrane and is not labeled by the lectin. By exploiting this phenomenon, an alternative Gram staining technique has been developed. Images PMID:1697149

  11. Quorum sensing in gram-negative bacteria

    DEFF Research Database (Denmark)

    Wu, H.; Song, Z.J.; Høiby, N.

    2004-01-01

    Bacteria can communicate with each other by means of signal molecules to coordinate the behavior of the entire community, and the mechanism is referred to as quorum sensing (QS). Signal systems enable bacteria to sense the size of their densities by monitoring the concentration of the signal...... molecules. Among Gram-negative bacteria N-acyl-L-homoserine lactone (acyl-HSL)-dependent quorum sensing systems are particularly widespread. These systems are used to coordinate expression of phenotypes that are fundamental to the interaction of bacteria with each other and with their environment...

  12. Abnormal levels of UV-induced unscheduled DNA synthesis in ataxia telangiectasia cells after exposure to ionizing radiation

    International Nuclear Information System (INIS)

    Jaspers, N.G.J.; Nederlandse Centrale Organisatie voor Toegepast Natuurwetenschappelijk Onderzoek, Rijswijk. Medical Biological Lab.); Bootsma, D.

    1982-01-01

    In cultured cells from normal individuals and from patients having ataxia telangiectasia (AT) the rate of unscheduled DNA synthesis (UDS) induced by UV light was investigated by autoradiography. The number of grains in 6 different AT cell strains was similar to that observed in normal cells. Exposure of normal cells to doses of X-rays up to 20 krad had no influence on the rate of UV-induced UDS. In contrast, the UV-induced UDS was significantly modified in AT cells by treatment with X-rays. In AT cell strains that were reported to have reduced levels of γ-ray-induced repair DNA synthesis ('excision-deficient' AT cells) the effect of X-rays on UV-induced UDS was inhibitory, whereas UV-induced UDS was stimulated by X-ray exposure in 'excision-proficient' AT cell strains. Different UV and X-ray dose-response relationships were seen in the two categories of AT cell strains. (orig./AJ)

  13. Histone deacetylase inhibition decreases cholesterol levels in neuronal cells by modulating key genes in cholesterol synthesis, uptake and efflux.

    Directory of Open Access Journals (Sweden)

    Maria João Nunes

    Full Text Available Cholesterol is an essential component of the central nervous system and increasing evidence suggests an association between brain cholesterol metabolism dysfunction and the onset of neurodegenerative disorders. Interestingly, histone deacetylase inhibitors (HDACi such as trichostatin A (TSA are emerging as promising therapeutic approaches in neurodegenerative diseases, but their effect on brain cholesterol metabolism is poorly understood. We have previously demonstrated that HDACi up-regulate CYP46A1 gene transcription, a key enzyme in neuronal cholesterol homeostasis. In this study, TSA was shown to modulate the transcription of other genes involved in cholesterol metabolism in human neuroblastoma cells, namely by up-regulating genes that control cholesterol efflux and down-regulating genes involved in cholesterol synthesis and uptake, thus leading to an overall decrease in total cholesterol content. Furthermore, co-treatment with the amphipathic drug U18666A that can mimic the intracellular cholesterol accumulation observed in cells of Niemman-Pick type C patients, revealed that TSA can ameliorate the phenotype induced by pathological cholesterol accumulation, by restoring the expression of key genes involved in cholesterol synthesis, uptake and efflux and promoting lysosomal cholesterol redistribution. These results clarify the role of TSA in the modulation of neuronal cholesterol metabolism at the transcriptional level, and emphasize the idea of HDAC inhibition as a promising therapeutic tool in neurodegenerative disorders with impaired cholesterol metabolism.

  14. Widespread Fosfomycin Resistance in Gram-Negative Bacteria Attributable to the Chromosomal fosA Gene

    Directory of Open Access Journals (Sweden)

    Ryota Ito

    2017-08-01

    Full Text Available Fosfomycin is a decades-old antibiotic which is being revisited because of its perceived activity against many extensively drug-resistant Gram-negative pathogens. FosA proteins are Mn2+ and K+-dependent glutathione S-transferases which confer fosfomycin resistance in Gram-negative bacteria by conjugation of glutathione to the antibiotic. Plasmid-borne fosA variants have been reported in fosfomycin-resistant Escherichia coli strains. However, the prevalence and distribution of fosA in other Gram-negative bacteria are not known. We systematically surveyed the presence of fosA in Gram-negative bacteria in over 18,000 published genomes from 18 Gram-negative species and investigated their contribution to fosfomycin resistance. We show that FosA homologues are present in the majority of genomes in some species (e.g., Klebsiella spp., Enterobacter spp., Serratia marcescens, and Pseudomonas aeruginosa, whereas they are largely absent in others (e.g., E. coli, Acinetobacter baumannii, and Burkholderia cepacia. FosA proteins in different bacterial pathogens are highly divergent, but key amino acid residues in the active site are conserved. Chromosomal fosA genes conferred high-level fosfomycin resistance when expressed in E. coli, and deletion of chromosomal fosA in S. marcescens eliminated fosfomycin resistance. Our results indicate that FosA is encoded by clinically relevant Gram-negative species and contributes to intrinsic fosfomycin resistance.

  15. Solution Synthesis Approach to Colloidal Cesium Lead Halide Perovskite Nanoplatelets with Monolayer-Level Thickness Control

    Science.gov (United States)

    2016-01-01

    We report a colloidal synthesis approach to CsPbBr3 nanoplatelets (NPLs). The nucleation and growth of the platelets, which takes place at room temperature, is triggered by the injection of acetone in a mixture of precursors that would remain unreactive otherwise. The low growth temperature enables the control of the plate thickness, which can be precisely tuned from 3 to 5 monolayers. The strong two-dimensional confinement of the carriers at such small vertical sizes is responsible for a narrow PL, strong excitonic absorption, and a blue shift of the optical band gap by more than 0.47 eV compared to that of bulk CsPbBr3. We also show that the composition of the NPLs can be varied all the way to CsPbBr3 or CsPbI3 by anion exchange, with preservation of the size and shape of the starting particles. The blue fluorescent CsPbCl3 NPLs represent a new member of the scarcely populated group of blue-emitting colloidal nanocrystals. The exciton dynamics were found to be independent of the extent of 2D confinement in these platelets, and this was supported by band structure calculations. PMID:26726764

  16. Textualidad y gramática argumentativa

    Directory of Open Access Journals (Sweden)

    RAÚL FIRACATIVE-RUIZ

    2014-01-01

    Full Text Available La argumentación es un modo de organizar el discurso, cuya orientación se da para lograr el convencimiento del otro. El presente artículo acoge este precepto para abordar la propuesta argumentativa del autor italiano Vincenzo Lo Cascio desde la noción de textualidad . Gramática argumentativa es el nombre dado a esta apuesta teórica y surge de las ideas de la Nueva Retórica de Perelman. Lo Cascio propone la existencia de categorías sintácticas finitas, denominadas reglas categoriales e indicadores de fuerza , las cuales permiten orientar la información de los enunciados y analizar multiplicidad de discursos; por ello, es una teoría que sigue la línea de la sintaxis generativa de Noam Chomsky. El artículo plantea la necesidad de reconocer, desde la Gramática argumentativa, el potencial enunciativo de la palabra en situaciones comunicativas cotidianas, donde es preciso que los enunciadores sean conscientes del uso que hacen de la palabra.

  17. A new technique for Gram staining paraffin-embedded tissue.

    Science.gov (United States)

    Engbaek, K; Johansen, K S; Jensen, M E

    1979-01-01

    Five techniques for Gram staining bacteria in paraffin sections were compared on serial sections of pulmonary tissues from eight bacteriological necropsies. Brown and Hopp's method was the most satisfactory for distinguishing Gram-positive and Gram-negative bacteria. However, this method cannot be recommended as the preparations were frequently overstained, and the Gram-negative bacteria were stained indistinctly. A modification of Brown and Hopps' method was developed which stains larger numbers of Gram-negative bacteria and differentiates well between different cell types and connective tissue, and there is no risk of overstaining. PMID:86548

  18. A Guide to Visual Multi-Level Interface Design From Synthesis of Empirical Study Evidence

    CERN Document Server

    Lam, Heidi

    2010-01-01

    Displaying multiple levels of data visually has been proposed to address the challenge of limited screen space. Although many previous empirical studies have addressed different aspects of this question, the information visualization research community does not currently have a clearly articulated consensus on how, when, or even if displaying data at multiple levels is effective. To shed more light on this complex topic, we conducted a systematic review of 22 existing multi-level interface studies to extract high-level design guidelines. To facilitate discussion, we cast our analysis findings

  19. Techniques for controlling variability in gram staining of obligate anaerobes.

    Science.gov (United States)

    Johnson, M J; Thatcher, E; Cox, M E

    1995-01-01

    Identification of anaerobes recovered from clinical samples is complicated by the fact that certain gram-positive anaerobes routinely stain gram negative; Peptostreptococcus asaccharolyticus, Eubacterium plautii, Clostridium ramosum, Clostridium symbiosum, and Clostridium clostridiiforme are among the nonconformists with regard to conventional Gram-staining procedures. Accurate Gram staining of American Type Culture Collection strains of these anaerobic bacteria is possible by implementing fixing and staining techniques within a gloveless anaerobic chamber. Under anaerobic conditions, gram-positive staining occurred in all test organisms with "quick" fixing techniques with both absolute methanol and formalin. The results support the hypothesis that, when anaerobic bacteria are exposed to oxygen, a breakdown of the physical integrity of the cell wall occurs, introducing Gram stain variability in gram-positive anaerobes. PMID:7538512

  20. Bioengineered nisin A derivatives with enhanced activity against both Gram positive and Gram negative pathogens.

    Directory of Open Access Journals (Sweden)

    Des Field

    Full Text Available Nisin is a bacteriocin widely utilized in more than 50 countries as a safe and natural antibacterial food preservative. It is the most extensively studied bacteriocin, having undergone decades of bioengineering with a view to improving function and physicochemical properties. The discovery of novel nisin variants with enhanced activity against clinical and foodborne pathogens has recently been described. We screened a randomized bank of nisin A producers and identified a variant with a serine to glycine change at position 29 (S29G, with enhanced efficacy against S. aureus SA113. Using a site-saturation mutagenesis approach we generated three more derivatives (S29A, S29D and S29E with enhanced activity against a range of Gram positive drug resistant clinical, veterinary and food pathogens. In addition, a number of the nisin S29 derivatives displayed superior antimicrobial activity to nisin A when assessed against a range of Gram negative food-associated pathogens, including E. coli, Salmonella enterica serovar Typhimurium and Cronobacter sakazakii. This is the first report of derivatives of nisin, or indeed any lantibiotic, with enhanced antimicrobial activity against both Gram positive and Gram negative bacteria.

  1. Bioengineered Nisin A Derivatives with Enhanced Activity against Both Gram Positive and Gram Negative Pathogens

    Science.gov (United States)

    Field, Des; Begley, Maire; O’Connor, Paula M.; Daly, Karen M.; Hugenholtz, Floor; Cotter, Paul D.; Hill, Colin; Ross, R. Paul

    2012-01-01

    Nisin is a bacteriocin widely utilized in more than 50 countries as a safe and natural antibacterial food preservative. It is the most extensively studied bacteriocin, having undergone decades of bioengineering with a view to improving function and physicochemical properties. The discovery of novel nisin variants with enhanced activity against clinical and foodborne pathogens has recently been described. We screened a randomized bank of nisin A producers and identified a variant with a serine to glycine change at position 29 (S29G), with enhanced efficacy against S. aureus SA113. Using a site-saturation mutagenesis approach we generated three more derivatives (S29A, S29D and S29E) with enhanced activity against a range of Gram positive drug resistant clinical, veterinary and food pathogens. In addition, a number of the nisin S29 derivatives displayed superior antimicrobial activity to nisin A when assessed against a range of Gram negative food-associated pathogens, including E. coli, Salmonella enterica serovar Typhimurium and Cronobacter sakazakii. This is the first report of derivatives of nisin, or indeed any lantibiotic, with enhanced antimicrobial activity against both Gram positive and Gram negative bacteria. PMID:23056510

  2. A Trojan-Horse Strategy Including a Bacterial Suicide Action for the Efficient Use of a Specific Gram-Positive Antibiotic on Gram-Negative Bacteria.

    Science.gov (United States)

    Schalk, Isabelle J

    2018-05-10

    In the alarming context of rising bacterial antibiotic resistance, there is an urgent need to discover new antibiotics or increase and/or enlarge the activity of those currently in use. The need for new antibiotics is even more urgent in the case of Gram-negative bacteria, such as Acinetobacter, Pseudomonas, and Enterobacteria, which have become resistant to many antibiotics and have an outer membrane with very low permeability to drugs. Vectorization of antibiotics using siderophores may be a solution to bypass such a bacterial wall: the drugs use the iron transporters of the outer membrane as gates to enter bacteria in a Trojan-horse strategy. Designing siderophore-antibiotics that can cross outer membranes has become almost routine, but their transport across the inner membrane is still a limiting step, as well as a strategy that allows dissociation of the antibiotic from the siderophore once inside the bacteria. Liu et al. ( J. Med. Chem. 2018 , DOI: 10.1021/acs.jmedchem.8b00218 ) report the synthesis of a siderophore-cephalosporin compound and demonstrate that β-lactams, such as cephalosporins, can serve as β-lactamase-triggered releasable linkers to allow intracellular delivery of Gram-positive antibiotics to Gram-negative bacteria.

  3. Present-day sea level rise: a synthesis; Hausse actuelle du niveau de la mer: synthese

    Energy Technology Data Exchange (ETDEWEB)

    Cazenave, A.; Llovel, W. [Laboratoire d' Etudes en Geophysique et Oceanographie Spatiales (LEGOS), Observatoire Midi-Pyrenees, 31 - Toulouse (France); Lombard, A. [CNES, 31 - Toulouse (France)

    2008-11-15

    Measuring sea level change and understanding its causes have improved considerably in the recent years, essentially because new in situ and remote sensing data sets have become available. Here we report on the current knowledge of present-day sea level change. We briefly present observational results on sea level change from satellite altimetry since 1993 and tide gauges for the past century. We next discuss recent progress made in quantifying the processes causing sea level change on time scales ranging from years to decades, i.e., thermal expansion, land ice mass loss and land water storage change. For the 1993-2003 decade, the sum of climate-related contributions agree well (within the error bars) with the altimetry-based sea level, half of the observed rate of rise being due to ocean thermal expansion, land ice plus land waters explaining the other half. Since about 2003, thermal expansion increase has stopped, whereas the sea level continues to rise, although at a reduced rate compared to the previous decade (2.5 mm/yr versus 3.1 mm/yr). Recent increases in glacier melting and ice mass loss from the ice sheets appear able to account alone for the rise in sea level reported over the last five years. (authors)

  4. Identification of aerobic Gram-positive bacilli by use of Vitek MS.

    Science.gov (United States)

    Navas, Maria; Pincus, David H; Wilkey, Kathy; Sercia, Linda; LaSalvia, Margaret; Wilson, Deborah; Procop, Gary W; Richter, Sandra S

    2014-04-01

    The accuracy of Vitek MS mass spectrometric identifications was assessed for 206 clinically significant isolates of aerobic Gram-positive bacilli representing 20 genera and 38 species. The Vitek MS identifications were correct for 85% of the isolates (56.3% to the species level, 28.6% limited to the genus level), with misidentifications occurring for 7.3% of the isolates.

  5. Linezolid: a promising option in the treatment of Gram-positives.

    Science.gov (United States)

    Zahedi Bialvaei, Abed; Rahbar, Mohammad; Yousefi, Mehdi; Asgharzadeh, Mohammad; Samadi Kafil, Hossein

    2017-02-01

    Linezolid, an oxazolidinone antimicrobial agent that acts by inhibiting protein synthesis in a unique fashion, is used in the treatment of community-acquired pneumonia, skin and soft-tissue infections and other infections caused by Gram-positive bacteria including VRE and methicillin-resistant staphylococci. Currently, linezolid resistance among these pathogens remains low, commonly linezolid susceptibility testing for this important agent and should be taken into account when considering its therapeutic use. Considering the importance of linezolid in the treatment of infections caused by Gram-positive bacteria, this review was undertaken to optimize the clinical use of this antibiotic. © The Author 2016. Published by Oxford University Press on behalf of the British Society for Antimicrobial Chemotherapy. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  6. Synthesis of cytochrome c oxidase 1 (SCO1) inhibits insulin sensitivity by decreasing copper levels in adipocytes.

    Science.gov (United States)

    Wei, Xiang-Bo; Guo, Liang; Liu, Yang; Zhou, Shui-Rong; Liu, Yuan; Dou, Xin; Du, Shao-Yue; Ding, Meng; Peng, Wan-Qiu; Qian, Shu-Wen; Huang, Hai-Yan; Tang, Qi-Qun

    2017-09-23

    Dysregulation of insulin signaling leads to type 2 diabetes mellitus (T2DM) and other metabolic disorders. Obesity is an important contributor to insulin resistance, and although the understanding of this relationship has improved in recent years, the mechanism of obesity-induced insulin resistance is not completely understood. Disorders of copper metabolism tend to accompany the development of obesity, which increases the risk of insulin resistance. Synthesis of cytochrome c oxidase 1 (SCO1) functions in the assembly of cytochrome c oxidase (COX) and cellular copper homeostasis. However, the role of SCO1 in the regulation of metabolism remains unknown. Here, we found that obese mice had higher expression of SCO1 and lower levels of copper in white adipose tissue (WAT) than did the control mice. Overexpression of SCO1 in adipocytes was associated with copper deficiency. Copper increased insulin sensitivity by decreasing the level of phosphatase and tensin homolog (PTEN) protein. Ectopic expression of SCO1 led to insulin resistance and was accompanied by a decrease in intracellular copper level, and addition of copper abolished the inhibitory effect of SCO1 on insulin sensitivity. Our results demonstrated a novel role of SCO1 in modulating insulin sensitivity via the regulation of copper concentration in WAT and suggested a potential therapeutic target for T2DM. Copyright © 2017. Published by Elsevier Inc.

  7. Using MaxCompiler for High Level Synthesis of Trigger Algorithms

    CERN Document Server

    Summers, Sioni Paris; Sanders, P.

    2017-01-01

    Firmware for FPGA trigger applications at the CMS experiment is conventionally written using hardware description languages such as Verilog and VHDL. MaxCompiler is an alternative, Java based, tool for developing FPGA applications which uses a higher level of abstraction from the hardware than a hardware description language. An implementation of the jet and energy sum algorithms for the CMS Level-1 calorimeter trigger has been written using MaxCompiler to benchmark against the VHDL implementation in terms of accuracy, latency, resource usage, and code size. A Kalman Filter track fitting algorithm has been developed using MaxCompiler for a proposed CMS Level-1 track trigger for the High-Luminosity LHC upgrade. The design achieves a low resource usage, and has a latency of 187.5 ns per iteration.

  8. Using MaxCompiler for the high level synthesis of trigger algorithms

    International Nuclear Information System (INIS)

    Summers, S.; Rose, A.; Sanders, P.

    2017-01-01

    Firmware for FPGA trigger applications at the CMS experiment is conventionally written using hardware description languages such as Verilog and VHDL. MaxCompiler is an alternative, Java based, tool for developing FPGA applications which uses a higher level of abstraction from the hardware than a hardware description language. An implementation of the jet and energy sum algorithms for the CMS Level-1 calorimeter trigger has been written using MaxCompiler to benchmark against the VHDL implementation in terms of accuracy, latency, resource usage, and code size. A Kalman Filter track fitting algorithm has been developed using MaxCompiler for a proposed CMS Level-1 track trigger for the High-Luminosity LHC upgrade. The design achieves a low resource usage, and has a latency of 187.5 ns per iteration.

  9. Using MaxCompiler for the high level synthesis of trigger algorithms

    Science.gov (United States)

    Summers, S.; Rose, A.; Sanders, P.

    2017-02-01

    Firmware for FPGA trigger applications at the CMS experiment is conventionally written using hardware description languages such as Verilog and VHDL. MaxCompiler is an alternative, Java based, tool for developing FPGA applications which uses a higher level of abstraction from the hardware than a hardware description language. An implementation of the jet and energy sum algorithms for the CMS Level-1 calorimeter trigger has been written using MaxCompiler to benchmark against the VHDL implementation in terms of accuracy, latency, resource usage, and code size. A Kalman Filter track fitting algorithm has been developed using MaxCompiler for a proposed CMS Level-1 track trigger for the High-Luminosity LHC upgrade. The design achieves a low resource usage, and has a latency of 187.5 ns per iteration.

  10. High-level synthesis for reduction of WCET in real-time systems

    DEFF Research Database (Denmark)

    Kristensen, Andreas Toftegaard; Pezzarossa, Luca; Sparsø, Jens

    2017-01-01

    . Compared to executing the high-level language code on a processor, HLS can be used to create hardware that accelerates critical parts of the code. When discussing performance in the context or real-time systems, it is the worst-case execution time (WCET) of a task that matters. WCET obviously benefits from...... hardware acceleration, but it may also benefit from a tighter bound on the WCET. This paper explores the use of and integration of accelerators generated using HLS into a time-predictable processor intended for real-time systems. The high-level design tool, Vivado HLS, is used to generate hardware...

  11. Effects of dietary nitrogen levels and carbohydrate sources on apparent ruminal synthesis of some B vitamins in dairy cows.

    Science.gov (United States)

    Beaudet, V; Gervais, R; Graulet, B; Nozière, P; Doreau, M; Fanchone, A; Castagnino, D D S; Girard, C L

    2016-04-01

    Effects of nitrogen level and carbohydrate source on apparent ruminal synthesis (ARS) of thiamin, riboflavin, niacin, vitamin B6, folates, and vitamin B12 were evaluated using 4 lactating Holstein cows distributed in a 4 × 4 Latin square design with treatments following a 2 × 2 factorial arrangement. Cows were fitted with cannulas in the rumen and proximal duodenum. The treatments were 2 N levels and 2 carbohydrate sources. The diet with the high N level provided 14% crude protein, calculated to meet 110% of the protein requirements and an adequate supply in rumen-degradable protein, whereas the diet with the low N level contained 11% crude protein, calculated to meet 80% of the protein requirements with a shortage in rumen-degradable protein. Carbohydrate source treatments differed by their nature (i.e., high in starch from barley, corn, and wheat, or high in fiber from soybean hulls and dehydrated beet pulp). All 4 diets were isoenergetic, based on corn silage, and had the same forage-to-concentrate ratio (60:40, dry matter basis). Duodenal flow was determined using YbCl3 as a marker. Each B-vitamin ARS was calculated as duodenal flow minus daily intake. The intake of several B vitamins varied among treatments, but because the animals consumed a similar amount of feed every day (average of 20 kg of dry matter/d) the difference was mostly due to vitamin content of each ingredient and their relative proportion in the diets. Decreasing N concentration in the diet reduced vitamin B6 duodenal flow and increased its apparent ruminal degradation. It also decreased duodenal flow and ARS of folates. The high-starch diets increased duodenal flow and ruminal balance of riboflavin, vitamin B6, and folates, whereas the high-fiber diets increased vitamin B12 ARS and duodenal flow. These effects on apparent synthesis are possibly due to changes in ruminal fermentation. Copyright © 2016 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

  12. Antibacterial activity of sphingoid bases and fatty acids against Gram-positive and Gram-negative bacteria.

    Science.gov (United States)

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

    2012-03-01

    There is growing evidence that the role of lipids in innate immunity is more important than previously realized. How lipids interact with bacteria to achieve a level of protection, however, is still poorly understood. To begin to address the mechanisms of antibacterial activity, we determined MICs and minimum bactericidal concentrations (MBCs) of lipids common to the skin and oral cavity--the sphingoid bases D-sphingosine, phytosphingosine, and dihydrosphingosine and the fatty acids sapienic acid and lauric acid--against four Gram-negative bacteria and seven Gram-positive bacteria. Exact Kruskal-Wallis tests of these values showed differences among lipid treatments (P 500 μg/ml). Sapienic acid (MBC range, 31.3 to 375.0 μg/ml) was active against Streptococcus sanguinis, Streptococcus mitis, and Fusobacterium nucleatum but not active against Escherichia coli, Staphylococcus aureus, S. marcescens, P. aeruginosa, Corynebacterium bovis, Corynebacterium striatum, and Corynebacterium jeikeium (MBC > 500 μg/ml). Lauric acid (MBC range, 6.8 to 375.0 μg/ml) was active against all bacteria except E. coli, S. marcescens, and P. aeruginosa (MBC > 500 μg/ml). Complete killing was achieved as early as 0.5 h for some lipids but took as long as 24 h for others. Hence, sphingoid bases and fatty acids have different antibacterial activities and may have potential for prophylactic or therapeutic intervention in infection.

  13. The impact of Facebook use on micro-level social capital : A synthesis

    NARCIS (Netherlands)

    Antheunis, Marjolijn; Vanden Abeele, Mariek; Kanters, S.

    2015-01-01

    The relationship between Facebook use and micro-level social capital has received substantial scholarly attention over the past decade. This attention has resulted in a large body of empirical work that gives insight into the nature of Facebook as a social networking site and how it influences the

  14. A Transformational Approach to VHDL and CDFG Based High-Level Synthesis: a Case Study

    NARCIS (Netherlands)

    Middelhoek, Peter F.A.; Middelhoek, P.F.A.; Mekenkamp, G.E.; Molenkamp, Egbert; Krol, Th.

    1995-01-01

    In this paper, a novel multi-target design methodology based on the concepts of transformational design, and its application to the interlaced-to-progressive scan conversion (IPSC) problem, are discussed. Starting from a single high-level behavioral specification in VHDL a direction detector used in

  15. c-di-GMP Regulates Various Phenotypes and Insecticidal Activity of Gram-Positive Bacillus thuringiensis

    Directory of Open Access Journals (Sweden)

    Yang Fu

    2018-02-01

    Full Text Available C-di-GMP has been well investigated to play significant roles in the physiology of many Gram-negative bacteria. However, its effect on Gram-positive bacteria is less known. In order to more understand the c-di-GMP functions in Gram-positive bacteria, we have carried out a detailed study on the c-di-GMP-metabolizing enzymes and their physiological functions in Bacillus thuringiensis, a Gram-positive entomopathogenic bacterium that has been applied as an insecticide successfully. We performed a systematic study on the ten putative c-di-GMP-synthesizing enzyme diguanylate cyclases (DGCs and c-di-GMP-degrading enzyme phosphodiesterases (PDEs in B. thuringiensis BMB171, and artificially elevated the intracellular c-di-GMP level in BMB171 by deleting one or more pde genes. We found increasing level of intracellular c-di-GMP exhibits similar activities as those in Gram-negative bacteria, including altered activities in cell motility, biofilm formation, and cell-cell aggregation. Unexpectedly, we additionally found a novel function exhibited by the increasing level of c-di-GMP to promote the insecticidal activity of this bacterium against Helicoverpa armigera. Through whole-genome transcriptome profile analyses, we found that 4.3% of the B. thuringiensis genes were differentially transcribed when c-di-GMP level was increased, and 77.3% of such gene products are involved in some regulatory pathways not reported in other bacteria to date. In summary, our study represents the first comprehensive report on the c-di-GMP-metabolizing enzymes, their effects on phenotypes, and the transcriptome mediated by c-di-GMP in an important Gram-positive bacterium.

  16. Regulation of elastin synthesis in developing sheep nuchal ligament by elastin mRNA levels

    International Nuclear Information System (INIS)

    Davidson, J.M.; Smith, K.; Shibahara, S.; Tolstoshev, P.; Crystal, R.G.

    1982-01-01

    Levels of elastin production in explant culture of fetal sheep nuchal ligament and corresponding levels of translatable elastin mRNA were determined in parallel studies during a period of rapid growth of the embryo. The identity of the explant culture and cell-free proucts was confirmed by peptide mapping, immunoprecipitation, and the characteristic lack of histidine and methionine. Elastin production was quantitated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and radioimmune precipitation. The translation products could be labeled with methionine only when NH 2 -terminally donated as f-Met-tRNA/sup Met//sub f/. Explant cultures showed a large rise in elastin production from 70 days after conception to 150 days after conception. Cell free translation of RNA demonstrated a parallel in elastin mRNA levels and in elastin mRNA per cell. It appears, therefore, that the marked emphasis the differentiating muchal ligament places on elastin production is modulated, at least in part, by the quantities of available elastin in mRNA

  17. Gram staining in the diagnosis of acute septic arthritis.

    Science.gov (United States)

    Faraj, A A; Omonbude, O D; Godwin, P

    2002-10-01

    This study aimed at determining the sensitivity and specificity of Gram staining of synovial fluid as a diagnostic tool in acute septic arthritis. A retrospective study was made of 22 patients who had arthroscopic lavage following a provisional diagnosis of acute septic arthritis of the knee joint. Gram stains and cultures of the knee aspirates were compared with the clinical and laboratory parameters, to evaluate their usefulness in diagnosing acute arthritis. All patients who had septic arthritis had pain, swelling and limitation of movement. CRP was elevated in 90% of patients. The incidence of elevated white blood cell count was higher in the group of patients with a positive Gram stain study (60%) as compared to patients with a negative Gram stain study (33%). Gram staining sensitivity was 45%. Its specificity was however 100%. Gram staining is an unreliable tool in early decision making in patients requiring urgent surgical drainage and washout.

  18. Phosphorus Response and Amino Acid Composition of Different Green Gram (Vigna radiata L. Genotypes from Myanmar

    Directory of Open Access Journals (Sweden)

    M. Kywe

    2007-10-01

    Full Text Available Mungbean or green gram (Vigna radiata L. is an important component of rice-based cropping systems in Myanmar, where grain yields of around 800 kg ha^(-1 are much below its yield potential of 3000 kg ha^(-1. The reasons for this shortfall are as under-investigated as is the genotype-specific response of this crop to phosphorus (P application, which is critically low in many Myanmar soils, and the genetic variation in grain quality. For green gram quality, the concentration of lysine, an essential amino acid is particularly important given its scarcity in many cereal-based diets of Southeast Asia. The purpose of this study therefore was to investigate the effects of P application on the root and shoot growth, yield and its components for a range of green gram varieties, and to analyse the protein concentration and amino acid composition in green gram seed of different origins. To this end from 2001 to 2003, field experiments were conducted under rain-fed conditions in Yezin and Nyaung Oo. Fifteen landraces and five introduced green gram cultivars were grown at two levels of P (0 and 15 kg ha^(-1. There were large genotypic differences in P effects and a significant interaction between green gram genotypes and P for shoot and root growth. An unexpected benefit of P application was a reduction of pest and plant virus infestation in the field. Significant genotypic differences in the amino acid profile of seeds were also observed. The results indicate the potential for breeding efforts to increase seed yield and protein quality in green gram.

  19. Subcellular localization for Gram positive and Gram negative bacterial proteins using linear interpolation smoothing model.

    Science.gov (United States)

    Saini, Harsh; Raicar, Gaurav; Dehzangi, Abdollah; Lal, Sunil; Sharma, Alok

    2015-12-07

    Protein subcellular localization is an important topic in proteomics since it is related to a protein׳s overall function, helps in the understanding of metabolic pathways, and in drug design and discovery. In this paper, a basic approximation technique from natural language processing called the linear interpolation smoothing model is applied for predicting protein subcellular localizations. The proposed approach extracts features from syntactical information in protein sequences to build probabilistic profiles using dependency models, which are used in linear interpolation to determine how likely is a sequence to belong to a particular subcellular location. This technique builds a statistical model based on maximum likelihood. It is able to deal effectively with high dimensionality that hinders other traditional classifiers such as Support Vector Machines or k-Nearest Neighbours without sacrificing performance. This approach has been evaluated by predicting subcellular localizations of Gram positive and Gram negative bacterial proteins. Copyright © 2015 Elsevier Ltd. All rights reserved.

  20. Effects of γ radiation and hyperthermia on DNA repair synthesis and the level of NAD+ in cultured human mononuclear leukocytes

    International Nuclear Information System (INIS)

    Jonsson, G.G.; Eriksson, G.; Pero, R.W.

    1984-01-01

    DNA repair has been investigated, estimated by unscheduled DNA synthesis (UDS) and the cellular NAD + pool, after exposing human mononuclear leukocytes to hyperthermia and γ radiation separately and in combination. It was found that γ radiation induced a decline in UDS with increasing temperature through the temperature region studied (37-45 0 C). At 42.5 0 C the γ-ray-induced UDS was reduced to about 70% of that at 37 0 C. Following γ-ray damage the NAD + pool dropped to about 20% of control values. Without hyperthermic treatment the cells completely recovered to the original level within 5 hr. Moderate hyperthermia (42.5 0 C for 45 min) followed by γ-ray damage altered the kinetics so that even after 8 hr the NAD + pool had recovered to only 70% of the original level. After heat treatment at 44 0 C for 45 min prior to γ radiation the cells did not recover at all, presumably because of the cytotoxic effects from the combined treatment

  1. Diagnosing periprosthetic infection: false-positive intraoperative Gram stains.

    Science.gov (United States)

    Oethinger, Margret; Warner, Debra K; Schindler, Susan A; Kobayashi, Hideo; Bauer, Thomas W

    2011-04-01

    Intraoperative Gram stains have a reported low sensitivity but high specificity when used to help diagnose periprosthetic infections. In early 2008, we recognized an unexpectedly high frequency of apparent false-positive Gram stains from revision arthroplasties. The purpose of this report is to describe the cause of these false-positive test results. We calculated the sensitivity and specificity of all intraoperative Gram stains submitted from revision arthroplasty cases during a 3-month interval using microbiologic cultures of the same samples as the gold standard. Methods of specimen harvesting, handling, transport, distribution, specimen processing including tissue grinding/macerating, Gram staining, and interpretation were studied. After a test modification, results of specimens were prospectively collected for a second 3-month interval, and the sensitivity and specificity of intraoperative Gram stains were calculated. The retrospective review of 269 Gram stains submitted from revision arthroplasties indicated historic sensitivity and specificity values of 23% and 92%, respectively. Systematic analysis of all steps of the procedure identified Gram-stained but nonviable bacteria in commercial broth reagents used as diluents for maceration of periprosthetic membranes before Gram staining and culture. Polymerase chain reaction and sequencing showed mixed bacterial DNA. Evaluation of 390 specimens after initiating standardized Millipore filtering of diluent fluid revealed a reduced number of positive Gram stains, yielding 9% sensitivity and 99% specificity. Clusters of false-positive Gram stains have been reported in other clinical conditions. They are apparently rare related to diagnosing periprosthetic infections but have severe consequences if used to guide treatment. Even occasional false-positive Gram stains should prompt review of laboratory methods. Our observations implicate dead bacteria in microbiologic reagents as potential sources of false-positive Gram

  2. Defining a role for Hfq in Gram-positive bacteria

    DEFF Research Database (Denmark)

    Nielsen, Jesper Sejrup; Lei, Lisbeth Kristensen; Ebersbach, Tine

    2010-01-01

    Small trans-encoded RNAs (sRNAs) modulate the translation and decay of mRNAs in bacteria. In Gram-negative species, antisense regulation by trans-encoded sRNAs relies on the Sm-like protein Hfq. In contrast to this, Hfq is dispensable for sRNA-mediated riboregulation in the Gram-positive species......-dependent and -independent mechanisms, thus adding another layer of complexity to sRNA-mediated riboregulation in Gram-positive species....

  3. Orbit Classification of Qutrit via the Gram Matrix

    International Nuclear Information System (INIS)

    Tay, B. A.; Zainuddin, Hishamuddin

    2008-01-01

    We classify the orbits generated by unitary transformation on the density matrices of the three-state quantum systems (qutrits) via the Gram matrix. The Gram matrix is a real symmetric matrix formed from the Hilbert–Schmidt scalar products of the vectors lying in the tangent space to the orbits. The rank of the Gram matrix determines the dimensions of the orbits, which fall into three classes for qutrits. (general)

  4. Raman Spectroscopy of Xylitol Uptake and Metabolism in Gram-Positive and Gram-Negative Bacteria▿

    Science.gov (United States)

    Palchaudhuri, Sunil; Rehse, Steven J.; Hamasha, Khozima; Syed, Talha; Kurtovic, Eldar; Kurtovic, Emir; Stenger, James

    2011-01-01

    Visible-wavelength Raman spectroscopy was used to investigate the uptake and metabolism of the five-carbon sugar alcohol xylitol by Gram-positive viridans group streptococcus and the two extensively used strains of Gram-negative Escherichia coli, E. coli C and E. coli K-12. E. coli C, but not E. coli K-12, contains a complete xylitol operon, and the viridans group streptococcus contains an incomplete xylitol operon used to metabolize the xylitol. Raman spectra from xylitol-exposed viridans group streptococcus exhibited significant changes that persisted even in progeny grown from the xylitol-exposed mother cells in a xylitol-free medium for 24 h. This behavior was not observed in the E. coli K-12. In both viridans group streptococcus and the E. coli C derivative HF4714, the metabolic intermediates are stably formed to create an anomaly in bacterial normal survival. The uptake of xylitol by Gram-positive and Gram-negative pathogens occurs even in the presence of other high-calorie sugars, and its stable integration within the bacterial cell wall may discontinue bacterial multiplication. This could be a contributing factor for the known efficacy of xylitol when taken as a prophylactic measure to prevent or reduce occurrences of persistent infection. Specifically, these bacteria are causative agents for several important diseases of children such as pneumonia, otitis media, meningitis, and dental caries. If properly explored, such an inexpensive and harmless sugar-alcohol, alone or used in conjunction with fluoride, would pave the way to an alternative preventive therapy for these childhood diseases when the causative pathogens have become resistant to modern medicines such as antibiotics and vaccine immunotherapy. PMID:21037297

  5. The Impact of Facebook Use on Micro-Level Social Capital: A Synthesis

    Directory of Open Access Journals (Sweden)

    Marjolijn L. Antheunis

    2015-04-01

    Full Text Available The relationship between Facebook use and micro-level social capital has received substantial scholarly attention over the past decade. This attention has resulted in a large body of empirical work that gives insight into the nature of Facebook as a social networking site and how it influences the social benefits that people gather from having social relationships. Although the extant research provides a solid basis for future research into this area, a number of issues remain underexplored. The aim of the current article is twofold. First, it seeks to synthesize what is already known about the relationship between Facebook use and micro-level social capital. Second, it seeks to advance future research by identifying and analyzing relevant theoretical, analytical and methodological issues. To address the first research aim, we first present an overview and analysis of current research findings on Facebook use and social capital, in which we focus on what we know about (1 the relationship between Facebook use in general and the different subtypes of social capital; (2 the relationships between different types of Facebook interactions and social capital; and (3 the impact of self-esteem on the relationship between Facebook use and social capital. Based on this analysis, we subsequently identify three theoretical issues, two analytical issues and four methodological issues in the extant body of research, and discuss the implications of these issues for Facebook and social capital researchers.

  6. Reduction Expansion Synthesis as Strategy to Control Nitrogen Doping Level and Surface Area in Graphene

    Directory of Open Access Journals (Sweden)

    Russell Canty

    2015-10-01

    Full Text Available Graphene sheets doped with nitrogen were produced by the reduction-expansion (RES method utilizing graphite oxide (GO and urea as precursor materials. The simultaneous graphene generation and nitrogen insertion reactions are based on the fact that urea decomposes upon heating to release reducing gases. The volatile byproducts perform two primary functions: (i promoting the reduction of the GO and (ii providing the nitrogen to be inserted in situ as the graphene structure is created. Samples with diverse urea/GO mass ratios were treated at 800 °C in inert atmosphere to generate graphene with diverse microstructural characteristics and levels of nitrogen doping. Scanning electron microscopy (SEM and transmission electron microscopy (TEM were used to study the microstructural features of the products. The effects of doping on the samples structure and surface area were studied by X-ray diffraction (XRD, Raman Spectroscopy, and Brunauer Emmet Teller (BET. The GO and urea decomposition-reduction process as well as nitrogen-doped graphene stability were studied by thermogravimetric analysis (TGA coupled with mass spectroscopy (MS analysis of the evolved gases. Results show that the proposed method offers a high level of control over the amount of nitrogen inserted in the graphene and may be used alternatively to control its surface area. To demonstrate the practical relevance of these findings, as-produced samples were used as electrodes in supercapacitor and battery devices and compared with conventional, thermally exfoliated graphene.

  7. Utility of Gram staining for diagnosis of Malassezia folliculitis.

    Science.gov (United States)

    Tu, Wei-Ting; Chin, Szu-Ying; Chou, Chia-Lun; Hsu, Che-Yuan; Chen, Yu-Tsung; Liu, Donald; Lee, Woan-Ruoh; Shih, Yi-Hsien

    2018-02-01

    Malassezia folliculitis (MalF) mimics acne vulgaris and bacterial folliculitis in clinical presentations. The role of Gram staining in rapid diagnosis of MalF has not been well studied. In our study, 32 patients were included to investigate the utility of Gram staining for MalF diagnosis. The final diagnoses of MalF were determined according to clinical presentation, pathological result and treatment response to antifungal agents. Our results show that the sensitivity and specificity of Gram staining are 84.6% and 100%, respectively. In conclusion, Gram staining is a rapid, non-invasive, sensitive and specific method for MalF diagnosis. © 2017 Japanese Dermatological Association.

  8. Studies on tridecaptin B(1), a lipopeptide with activity against multidrug resistant Gram-negative bacteria.

    Science.gov (United States)

    Cochrane, Stephen A; Lohans, Christopher T; van Belkum, Marco J; Bels, Manon A; Vederas, John C

    2015-06-07

    Previously other groups had reported that Paenibacillus polymyxa NRRL B-30507 produces SRCAM 37, a type IIA bacteriocin with antimicrobial activity against Campylobacter jejuni. Genome sequencing and isolation of antimicrobial compounds from this P. polymyxa strain show that the antimicrobial activity is due to polymyxins and tridecaptin B1. The complete structural assignment, synthesis, and antimicrobial profile of tridecaptin B1 is reported, as well as the putative gene cluster responsible for its biosynthesis. This peptide displays strong activity against multidrug resistant Gram-negative bacteria, a finding that is timely to the current problem of antibiotic resistance.

  9. O-antigen protects gram-negative bacteria from histone killing.

    Directory of Open Access Journals (Sweden)

    Catherine Chaput

    Full Text Available Beyond their traditional role of wrapping DNA, histones display antibacterial activity to Gram-negative and -positive bacteria. To identify bacterial components that allow survival to a histone challenge, we selected resistant bacteria from homologous Escherichia coli libraries that harbor plasmids carrying pieces of the chromosome in different sizes. We identified genes required for exopolysaccharide production and for the synthesis of the polysaccharide domain of the lipopolysaccharide, called O-antigen. Indeed, O-antigen and exopolysaccharide conferred further resistance to histones. Notably, O-antigen also conferred resistance to histones in the pathogens Shigella flexneri and Klebsiella pneumoniae.

  10. DNA repair synthesis in rat retinal ganglion cells treated with chemical carcinogens or ultraviolet light in vitro, with special reference to aging and repair level

    International Nuclear Information System (INIS)

    Ishikawa, T.; Takayama, S.; Kitagawa, T.

    1978-01-01

    A system in which the retinal tissues of noninbred Wistar rats were used in combination with autoradiography was developed for measurement of DNA repair synthesis in ganglion cells of the central nervous system. Retinal tissues in short-term organ culture were treated with various carcinogens plus tritiated thymidine ([methyl -3 H]dThd) or were irradiated with uv light and then treated with [methyl -3 H]dThd. Preliminary study with retinal tissues from rats at various ages revealed no age-associated changes in the levels of unscheduled DNA synthesis in ganglion cells

  11. Clinical update on linezolid in the treatment of Gram-positive bacterial infections

    Science.gov (United States)

    Ager, Sally; Gould, Kate

    2012-01-01

    Gram-positive pathogens are a significant cause of morbidity and mortality in both community and health care settings. Glycopeptides have traditionally been the antibiotics of choice for multiresistant Gram-positive pathogens but there are problems with their use, including the emergence of glycopeptide-resistant strains, tissue penetration, and achieving and monitoring adequate serum levels. Newer antibiotics such as linezolid, a synthetic oxazolidinone, are available for the treatment of resistant Gram-positive bacteria. Linezolid is active against a wide range of Gram-positive bacteria and has been generally available for the treatment of Gram-positive infections since 2000. There are potential problems with linezolid use, including its bacteriostatic action and the relatively high incidence of reported adverse effects, particularly with long-term use. Long-term use may also be complicated by the development of resistance. However, linezolid has been shown to be clinically useful in the treatment of several serious infections where traditionally bacteriocidal agents have been required and many of its adverse effects are reversible on cessation. It has also been shown to be a cost-effective treatment option in several studies, with its high oral bioavailability allowing an early change from intravenous to oral formulations with consequent earlier patient discharge and lower inpatient costs. PMID:22787406

  12. Bruchid egg induced transcript dynamics in developing seeds of black gram (Vigna mungo.

    Directory of Open Access Journals (Sweden)

    Indrani K Baruah

    Full Text Available Black gram (Vigna mungo seeds are a rich source of digestible proteins, however, during storage these seeds are severely damaged by bruchids (Callosobruchus spp., reducing seed quality and yield losses. Most of the cultivated genotypes of black gram are susceptible to bruchids, however, few tolerant genotypes have also been identified but the mechanism of tolerance is poorly understood. We employed Suppression Subtractive Hybridization (SSH to identify specifically, but rarely expressed bruchid egg induced genes in black gram. In this study, Suppression Subtractive Hybridization (SSH library was constructed to study the genes involved in defense response in black gram against bruchid infestation. An EST library of 277 clones was obtained for further analyses. Based on CAP3 assembly, 134 unigenes were computationally annotated using Blast2GOPRO software. In all, 20 defense related genes were subject to quantitative PCR analysis (qPCR out of which 12 genes showed up-regulation in developing seeds of the pods oviposited by bruchids. Few major defense genes like defensin, pathogenesis related protein (PR, lipoxygenase (LOX showed high expression levels in the oviposited population when compared with the non-oviposited plants. This is the first report on defense related gene transcript dynamics during the bruchid-black gram interaction using SSH library. This library would be useful to clone defense related gene(s such as defensin as represented in our library for crop improvement.

  13. Numerically Stable Evaluation of Moments of Random Gram Matrices With Applications

    KAUST Repository

    Elkhalil, Khalil; Kammoun, Abla; Al-Naffouri, Tareq Y.; Alouini, Mohamed-Slim

    2017-01-01

    This paper focuses on the computation of the positive moments of one-side correlated random Gram matrices. Closed-form expressions for the moments can be obtained easily, but numerical evaluation thereof is prone to numerical stability, especially in high-dimensional settings. This letter provides a numerically stable method that efficiently computes the positive moments in closed-form. The developed expressions are more accurate and can lead to higher accuracy levels when fed to moment based-approaches. As an application, we show how the obtained moments can be used to approximate the marginal distribution of the eigenvalues of random Gram matrices.

  14. Numerically Stable Evaluation of Moments of Random Gram Matrices With Applications

    KAUST Repository

    Elkhalil, Khalil

    2017-07-31

    This paper focuses on the computation of the positive moments of one-side correlated random Gram matrices. Closed-form expressions for the moments can be obtained easily, but numerical evaluation thereof is prone to numerical stability, especially in high-dimensional settings. This letter provides a numerically stable method that efficiently computes the positive moments in closed-form. The developed expressions are more accurate and can lead to higher accuracy levels when fed to moment based-approaches. As an application, we show how the obtained moments can be used to approximate the marginal distribution of the eigenvalues of random Gram matrices.

  15. In vitro activity of daptomycin against clinical isolates of Gram-positive bacteria.

    Science.gov (United States)

    Piper, Kerryl E; Steckelberg, James M; Patel, Robin

    2005-08-01

    We determined the activity of daptomycin, a recently FDA-approved antimicrobial agent, against clinical isolates of Gram-positive bacteria, including viridans group streptococci (16 Streptococcus mitis species group, 12 S. mutans species group, 9 S. anginosus species group, 8 S. sanguinis species group, 5 S. salivarius species group) from patients with infective endocarditis, 32 methicillin-resistant Staphylococcus aureus, 32 high-level penicillin-resistant Streptococcus pneumoniae, 38 vancomycin-resistant enterococci (including 1 linezolid-resistant isolate), and the following unusual Gram-positive bacteria: 3 Listeria monocytogenes, 4 Erysipelothrix rhusiopathiae, 9 Corynebacterium species, 10 Abiotrophia/Granulicatella species, 2 Rothia (Stomatococcus) mucilaginosus, and 4 Gemella morbillorum. Daptomycin minimum inhibitory concentration (MIC)(90) values for the viridans group streptococci, methicillin-resistant S. aureus, penicillin-resistant S. pneumoniae, and Enterococcus species were 0.5, 0.5, endocarditis as well as against several types of unusual Gram-positive bacteria that can cause endocarditis.

  16. Antimicrobial Activity of Carbon Nanoparticles Isolated from Natural Sources against Pathogenic Gram-Negative and Gram-Positive Bacteria

    International Nuclear Information System (INIS)

    Varghese, S.; Jose, S.; Varghese, S.; Kuriakose, S.; Jose, S.

    2013-01-01

    This paper describes the isolation of carbon nanoparticles (CNPs) from kitchen soot, characterization of the CNPs by UV/visible spectroscopy, SEM and XRD, and their antimicrobial action. The antibacterial activity of the isolated carbon nanoparticles was tested against various pathogenic bacterial strains such as Gram-negative Proteus refrigere and Pseudomonas aeruginosa and Gram-positive Staphylococcus aureus and Streptococcus haemolyticus. The inhibition zones were measured, and it was found that the carbon nanoparticles isolated from natural sources are active against these Gram-negative and Gram-positive bacterial strains

  17. Brief draft on surface and subsurface storage of high level and long-lived radioactive wastes. Spent fuels synthesis file

    International Nuclear Information System (INIS)

    Dumas, C.; Jaecki, P.

    2002-01-01

    This document makes a synthesis of the results of two brief draft studies performed in 2002 about the surface and subsurface storage of spent fuels. These studies stress on the long duration aspect of the disposal: feasibility of a secular disposal facility, potential risks and safety level of such a facility, estimation of the initial investment and of operation and maintenance costs. The main points of the specifications and the input data are presented first, and then the subsurface and surface draft studies are described. Content: specifications (imposed design principles and options, dry corrosion, input data); subsurface storage (description and design options, thermal dimensioning and ventilation, geotechnical stability of the facility, subsurface water management, dry corrosion, infrastructure durability, safety, monitoring, security and physical protection, technical-economical aspects, case of Mox fuel, case of glass packages); surface storage (description and design options, thermal dimensioning and ventilation, mechanical dimensioning of the facility, dry corrosion, infrastructure durability, safety, monitoring, security and physical protection, technical-economical aspects, case of Mox fuel, case of glass packages); conclusions and perspectives. (J.S.)

  18. Synthesis, characterization and antibacterial activity against Gram positive and Gram negative bacteria of biomimetically coated silver nanoparticles.

    Science.gov (United States)

    Amato, Elvio; Diaz-Fernandez, Yuri A; Taglietti, Angelo; Pallavicini, Piersandro; Pasotti, Luca; Cucca, Lucia; Milanese, Chiara; Grisoli, Pietro; Dacarro, Cesare; Fernandez-Hechavarria, Jose M; Necchi, Vittorio

    2011-08-02

    In the present work, we describe a simple procedure to produce biomimetically coated silver nanoparticles (Ag NPs), based on the postfunctionalization and purification of colloidal silver stabilized by citrate. Two biological capping agents have been used (cysteine Cys and glutathione GSH). The composition of the capped colloids has been ascertained by different techniques and antibacterial tests on GSH-capped Ag NPs have been conducted under physiological conditions, obtaining values of Minimum Inhibitory Concentration (MIC) of 180 and 15 μg/mL for Staphylococcus aureus and Escherichia coli, respectively. The antibacterial activity of these GSH capped NPs can be ascribed to the direct action of metallic silver NPs, rather than to the bulk release of Ag(+).

  19. Ant colony optimisation-direct cover: a hybrid ant colony direct cover technique for multi-level synthesis of multiple-valued logic functions

    Science.gov (United States)

    Abd-El-Barr, Mostafa

    2010-12-01

    The use of non-binary (multiple-valued) logic in the synthesis of digital systems can lead to savings in chip area. Advances in very large scale integration (VLSI) technology have enabled the successful implementation of multiple-valued logic (MVL) circuits. A number of heuristic algorithms for the synthesis of (near) minimal sum-of products (two-level) realisation of MVL functions have been reported in the literature. The direct cover (DC) technique is one such algorithm. The ant colony optimisation (ACO) algorithm is a meta-heuristic that uses constructive greediness to explore a large solution space in finding (near) optimal solutions. The ACO algorithm mimics the ant's behaviour in the real world in using the shortest path to reach food sources. We have previously introduced an ACO-based heuristic for the synthesis of two-level MVL functions. In this article, we introduce the ACO-DC hybrid technique for the synthesis of multi-level MVL functions. The basic idea is to use an ant to decompose a given MVL function into a number of levels and then synthesise each sub-function using a DC-based technique. The results obtained using the proposed approach are compared to those obtained using existing techniques reported in the literature. A benchmark set consisting of 50,000 randomly generated 2-variable 4-valued functions is used in the comparison. The results obtained using the proposed ACO-DC technique are shown to produce efficient realisation in terms of the average number of gates (as a measure of chip area) needed for the synthesis of a given MVL function.

  20. Formalin-induced behavioural hypersensitivity and neuronal hyperexcitability are mediated by rapid protein synthesis at the spinal level

    Science.gov (United States)

    Asante, Curtis O; Wallace, Victoria C; Dickenson, Anthony H

    2009-01-01

    Background The mammalian target of rapamycin (mTOR) is a key regulator of mRNA translation whose action can be inhibited by the drug rapamycin. Forms of long-term plasticity require protein synthesis and evidence indicates that mRNA in dendrites, axon terminals and cell bodies is essential for long-term synaptic plasticity. Specific to pain, shifts in pain thresholds and responsiveness are an expression of neuronal plasticity and this likely contributes to persistent pain. We investigated this by inhibiting the activity of mTOR with rapamycin at the spinal level, of rats that were subjected to the formalin test, using both behavioural and electrophysiological techniques. Results For in vivo electrophysiology, Sprague Dawley rats were fully anaesthetised and single-unit extracellular recordings were obtained from lamina V wide dynamic range (WDR) dorsal horn spinal neurones at the region where input is received from the hind paw. Neuronal responses from naive rats showed that rapamycin-sensitive pathways were important in nociceptive-specific C-fibre mediated transmission onto WDR neurones as well mechanically-evoked responses since rapamycin was effective in attenuating these measures. Formalin solution was injected into the hind paw prior to which, rapamycin or vehicle was applied directly onto the exposed spinal cord. When rapamycin was applied to the spinal cord prior to hind paw formalin injection, there was a significant attenuation of the prolonged second phase of the formalin test, which comprises continuing afferent input to the spinal cord, neuronal hyperexcitability and an activated descending facilitatory drive from the brainstem acting on spinal neurones. In accordance with electrophysiological data, behavioural studies showed that rapamycin attenuated behavioural hypersensitivity elicited by formalin injection into the hind paw. Conclusion We conclude that mTOR has a role in maintaining persistent pain states via mRNA translation and thus protein

  1. Formalin-induced behavioural hypersensitivity and neuronal hyperexcitability are mediated by rapid protein synthesis at the spinal level

    Directory of Open Access Journals (Sweden)

    Wallace Victoria C

    2009-06-01

    Full Text Available Abstract Background The mammalian target of rapamycin (mTOR is a key regulator of mRNA translation whose action can be inhibited by the drug rapamycin. Forms of long-term plasticity require protein synthesis and evidence indicates that mRNA in dendrites, axon terminals and cell bodies is essential for long-term synaptic plasticity. Specific to pain, shifts in pain thresholds and responsiveness are an expression of neuronal plasticity and this likely contributes to persistent pain. We investigated this by inhibiting the activity of mTOR with rapamycin at the spinal level, of rats that were subjected to the formalin test, using both behavioural and electrophysiological techniques. Results For in vivo electrophysiology, Sprague Dawley rats were fully anaesthetised and single-unit extracellular recordings were obtained from lamina V wide dynamic range (WDR dorsal horn spinal neurones at the region where input is received from the hind paw. Neuronal responses from naive rats showed that rapamycin-sensitive pathways were important in nociceptive-specific C-fibre mediated transmission onto WDR neurones as well mechanically-evoked responses since rapamycin was effective in attenuating these measures. Formalin solution was injected into the hind paw prior to which, rapamycin or vehicle was applied directly onto the exposed spinal cord. When rapamycin was applied to the spinal cord prior to hind paw formalin injection, there was a significant attenuation of the prolonged second phase of the formalin test, which comprises continuing afferent input to the spinal cord, neuronal hyperexcitability and an activated descending facilitatory drive from the brainstem acting on spinal neurones. In accordance with electrophysiological data, behavioural studies showed that rapamycin attenuated behavioural hypersensitivity elicited by formalin injection into the hind paw. Conclusion We conclude that mTOR has a role in maintaining persistent pain states via m

  2. Glass bead transformation method for gram-positive bacteria

    OpenAIRE

    Rattanachaikunsopon, Pongsak; Phumkhachorn, Parichat

    2009-01-01

    A simple, inexpensive and reproducible transformation method was developed for Gram-positive bacteria. It was based on agitation of bacterial protoplasts with glass beads in the presence of DNA and polyethylene glycol. By using this method, introduction of pGK12 into protoplasts of several strains of Gram-positive bacteria was achieved.

  3. Methods for targetted mutagenesis in gram-positive bacteria

    Science.gov (United States)

    Yang, Yunfeng

    2014-05-27

    The present invention provides a method of targeted mutagenesis in Gram-positive bacteria. In particular, the present invention provides a method that effectively integrates a suicide integrative vector into a target gene in the chromosome of a Gram-positive bacterium, resulting in inactivation of the target gene.

  4. Genetic diversity in green gram accessions as revealed by STMS ...

    African Journals Online (AJOL)

    Molecular characterization of green gram (Vigna radiata (L.) Wilczek) germplasm is essential for scientific assessment of variability and diversity for its better utilization in breeding programs. In this study, 120 accessions of green gram were analysed for 27 Sequence Tagged Microsatellites (STMS) loci. For data analysis ...

  5. Gram-positive bacteria persisting in the food production environment

    DEFF Research Database (Denmark)

    Knøchel, Susanne; Harmsen, Morten; Knudsen, Bettina

    2008-01-01

    Many gram-positive bacteria are able to form aggregates or biofilms and resist external stress factors and some gram-positive pathogenic bacteria such as Listeria monocytogenes and Bacillus cereus may persist in the food production environment for extended periods. Most research has focussed...

  6. Cell wall elongation mode in Gram-negative bacteria is determined by peptidoglycan architecture.

    Science.gov (United States)

    Turner, Robert D; Hurd, Alexander F; Cadby, Ashley; Hobbs, Jamie K; Foster, Simon J

    2013-01-01

    Cellular integrity and morphology of most bacteria is maintained by cell wall peptidoglycan, the target of antibiotics essential in modern healthcare. It consists of glycan strands, cross-linked by peptides, whose arrangement determines cell shape, prevents lysis due to turgor pressure and yet remains dynamic to allow insertion of new material, and hence growth. The cellular architecture and insertion pattern of peptidoglycan have remained elusive. Here we determine the peptidoglycan architecture and dynamics during growth in rod-shaped Gram-negative bacteria. Peptidoglycan is made up of circumferentially oriented bands of material interspersed with a more porous network. Super-resolution fluorescence microscopy reveals an unexpected discontinuous, patchy synthesis pattern. We present a consolidated model of growth via architecture-regulated insertion, where we propose only the more porous regions of the peptidoglycan network that are permissive for synthesis.

  7. Synergistic antibacterial effect of silver and ebselen against multidrug-resistant Gram-negative bacterial infections.

    Science.gov (United States)

    Zou, Lili; Lu, Jun; Wang, Jun; Ren, Xiaoyuan; Zhang, Lanlan; Gao, Yu; Rottenberg, Martin E; Holmgren, Arne

    2017-08-01

    Multidrug-resistant (MDR) Gram-negative bacteria account for a majority of fatal infections, and development of new antibiotic principles and drugs is therefore of outstanding importance. Here, we report that five most clinically difficult-to-treat MDR Gram-negative bacteria are highly sensitive to a synergistic combination of silver and ebselen. In contrast, silver has no synergistic toxicity with ebselen on mammalian cells. The silver and ebselen combination causes a rapid depletion of glutathione and inhibition of the thioredoxin system in bacteria. Silver ions were identified as strong inhibitors of Escherichia coli thioredoxin and thioredoxin reductase, which are required for ribonucleotide reductase and DNA synthesis and defense against oxidative stress. The bactericidal efficacy of silver and ebselen was further verified in the treatment of mild and acute MDR E. coli peritonitis in mice. These results demonstrate that thiol-dependent redox systems in bacteria can be targeted in the design of new antibacterial drugs. The silver and ebselen combination offers a proof of concept in targeting essential bacterial systems and might be developed for novel efficient treatments against MDR Gram-negative bacterial infections. © 2017 The Authors. Published under the terms of the CC BY 4.0 license.

  8. Decreased mortality associated with prompt Gram staining of blood cultures.

    Science.gov (United States)

    Barenfanger, Joan; Graham, Donald R; Kolluri, Lavanya; Sangwan, Gaurav; Lawhorn, Jerry; Drake, Cheryl A; Verhulst, Steven J; Peterson, Ryan; Moja, Lauren B; Ertmoed, Matthew M; Moja, Ashley B; Shevlin, Douglas W; Vautrain, Robert; Callahan, Charles D

    2008-12-01

    Gram stains of positive blood cultures are the most important factor influencing appropriate therapy. The sooner appropriate therapy is initiated, the better. Therefore, it is reasonable to expect that the sooner Gram stains are performed, the better. To determine the value of timely Gram stains and whether improvement in Gram stain turnaround time (TAT) is feasible, we compared data for matched pairs of patients with cultures processed promptly ( or =1 hour TAT) and then monitored TAT by control charting.In 99 matched pairs, average difference in time to detection of positive blood cultures within a pair of patients was less than 0.1 hour. For the less than 1 hour TAT group, the average TAT and crude mortality were 0.1 hour and 10.1%, respectively; for the 1 hour or longer TAT group, they were 3.3 hours and 19.2%, respectively (P Gram stains.

  9. Use of a knowledge synthesis by decision makers and planners to facilitate system level integration in a large Canadian provincial health authority

    Directory of Open Access Journals (Sweden)

    Esther Suter

    2011-03-01

    Full Text Available Purpose: The study is an examination of how a knowledge synthesis, conducted to fill an information gap identified by decision makers and planners responsible for integrating health systems in a western Canadian health authority, is being used within that organisation. Methods: Purposive sampling and snowball technique were used to identify 13 participants who were interviewed about how they are using the knowledge synthesis for health services planning and decision-making. Results: The knowledge synthesis is used by those involved in the strategic direction of the provincial healthcare organisation and those tasked with the operationalization of integration at the provincial or local level. Both groups most frequently use the ten key principles for integration, followed by the sections on integration processes, strategies and models. The key principles facilitate discussion on priority areas to be considered and provide a reference point for a desired future state. Perceived information gaps relate to a lack of detail on "how to" strategies, tools and processes that would lead to successful integration. Discussion and conclusion: The current project demonstrates that decision makers and planners will effectively use a knowledge synthesis if it is timely, relevant and accessible. The information can be applied at strategic and operations levels. Attention needs to be paid to include more information on implementation strategies and processes. Including knowledge users in identifying research questions will increase information uptake.

  10. Use of a knowledge synthesis by decision makers and planners to facilitate system level integration in a large Canadian provincial health authority

    Directory of Open Access Journals (Sweden)

    Esther Suter

    2011-03-01

    Full Text Available Purpose: The study is an examination of how a knowledge synthesis, conducted to fill an information gap identified by decision makers and planners responsible for integrating health systems in a western Canadian health authority, is being used within that organisation.Methods: Purposive sampling and snowball technique were used to identify 13 participants who were interviewed about how they are using the knowledge synthesis for health services planning and decision-making.Results: The knowledge synthesis is used by those involved in the strategic direction of the provincial healthcare organisation and those tasked with the operationalization of integration at the provincial or local level. Both groups most frequently use the ten key principles for integration, followed by the sections on integration processes, strategies and models. The key principles facilitate discussion on priority areas to be considered and provide a reference point for a desired future state. Perceived information gaps relate to a lack of detail on "how to" strategies, tools and processes that would lead to successful integration.Discussion and conclusion: The current project demonstrates that decision makers and planners will effectively use a knowledge synthesis if it is timely, relevant and accessible. The information can be applied at strategic and operations levels. Attention needs to be paid to include more information on implementation strategies and processes. Including knowledge users in identifying research questions will increase information uptake.

  11. Recent development on the synthesis of calixcrowns and their application for cesium removal from high-level liquid waste

    International Nuclear Information System (INIS)

    Zhu Xiaowen; Gao Jianxun; Wang Jianchen; Yu Bo; Song Chongli

    2002-01-01

    The synthesis, extraction properties and molecular modeling of calixcrowns in concern of cesium removal is reviewed briefly. In particular, calix [4] crown-6 and some of its derivatives have been shown to be highly selective extractants for cesium ions

  12. Synthesis and antibacterial activity of novel enolphosphate derivatives.

    Science.gov (United States)

    Grison, Claude; Barthes, Nicolas; Finance, Chantal; Duval, Raphael E

    2010-10-01

    A new class of enolphosphates derivatives, the 1-alkenyldiphosphates, was designed and a rapid and efficient synthesis for these compounds was developed. These new molecules showed interesting in vitro antibacterial activities (MIC) against Gram-positive bacteria (Staphylococcus aureus) and Gram-negative pathogens including Pseudomonas aeruginosa and Escherichia coli. 2010 Elsevier Inc. All rights reserved.

  13. Effect of dietary protein quality and feeding level on milk secretion and mammary protein synthesis in the rat

    International Nuclear Information System (INIS)

    Sampson, D.A.; Jansen, G.R.

    1985-01-01

    Protein synthesis was studied in mammary tissue of rats fed diets deficient in protein quality and/or restricted in food intake throughout gestation and lactation. Diets containing 25% wheat gluten (WG), wheat gluten plus lysine and threonine (WGLT), or casein (C) were pair-fed from conception until day 15 of lactation at 100% or 85% of WG ad libitum consumption (PF100 and PF85, respectively). A seventh group was fed C ad libitum. Rates of protein synthesis were measured in vivo at day 15 of lactation from incorporation of [3- 3 H]phenylalanine. At both PF100 and PF85, fractional and absolute rates of mammary gland protein synthesis were two- to three-fold higher in rats fed C than in those fed WG. Pup weights showed similar treatment effects. Both mammary protein synthesis rates and pup weights were significantly higher in rats fed C at PF85 than rats fed WG ad libitum. Food restriction from PF100 to PF85 depressed pup weights and mammary protein synthesis rates in rats fed WGLT, but had no effect in rats fed WG. These results demonstrate that when food intake is restricted, improvement of protein quality of the maternal diet increases milk output in the rat in association with increased rates of mammary protein synthesis

  14. Distribution of multi-resistant Gram-negative versus Gram-positive bacteria in the hospital inanimate environment.

    Science.gov (United States)

    Lemmen, S W; Häfner, H; Zolldann, D; Stanzel, S; Lütticken, R

    2004-03-01

    We prospectively studied the difference in detection rates of multi-resistant Gram-positive and multi-resistant Gram-negative bacteria in the inanimate environment of patients harbouring these organisms. Up to 20 different locations around 190 patients were surveyed. Fifty-four patients were infected or colonized with methicillin-resistant Staphylococcus aureus (MRSA) or vancomycin-resistant enterococci (VRE) and 136 with multi-resistant Gram-negative bacteria. The environmental detection rate for MRSA or VRE was 24.7% (174/705 samples) compared with 4.9% (89/1827 samples) for multi-resistant Gram-negative bacteria (PGram-positive bacteria were isolated more frequently than Gram-negatives from the hands of patients (PGram-positive and Gram-negative isolates. Our results suggest that the inanimate environment serves as a secondary source for MRSA and VRE, but less so for Gram-negative bacteria. Thus, strict contact isolation in a single room with complete barrier precautions is recommended for MRSA or VRE; however, for multi-resistant Gram-negative bacteria, contact isolation with barrier precautions for close contact but without a single room seems sufficient. This benefits not only the patients, but also the hospital by removing some of the strain placed on already over-stretched resources.

  15. Dustborne and airborne gram-positive and gram-negative bacteria in high versus low ERMI homes

    Science.gov (United States)

    The study aimed at investigating Gram-positive and Gram-negative bacteria in moldy and non-moldy homes, as defined by the home's Environmental Relative Moldiness Index (ERMI) value. The ERMI values were determined from floor dust samples in 2010 and 2011 and homes were classified...

  16. earGram Actors: An Interactive Audiovisual System Based on Social Behavior

    Directory of Open Access Journals (Sweden)

    Peter Beyls

    2015-11-01

    Full Text Available In multi-agent systems, local interactions among system components following relatively simple rules often result in complex overall systemic behavior. Complex behavioral and morphological patterns have been used to generate and organize audiovisual systems with artistic purposes. In this work, we propose to use the Actor model of social interactions to drive a concatenative synthesis engine called earGram in real time. The Actor model was originally developed to explore the emergence of complex visual patterns. On the other hand, earGram was originally developed to facilitate the creative exploration of concatenative sound synthesis. The integrated audiovisual system allows a human performer to interact with the system dynamics while receiving visual and auditory feedback. The interaction happens indirectly by disturbing the rules governing the social relationships amongst the actors, which results in a wide range of dynamic spatiotemporal patterns. A performer thus improvises within the behavioural scope of the system while evaluating the apparent connections between parameter values and actual complexity of the system output.

  17. Protein classification using modified n-grams and skip-grams.

    Science.gov (United States)

    Islam, S M Ashiqul; Heil, Benjamin J; Kearney, Christopher Michel; Baker, Erich J

    2018-05-01

    Classification by supervised machine learning greatly facilitates the annotation of protein characteristics from their primary sequence. However, the feature generation step in this process requires detailed knowledge of attributes used to classify the proteins. Lack of this knowledge risks the selection of irrelevant features, resulting in a faulty model. In this study, we introduce a supervised protein classification method with a novel means of automating the work-intensive feature generation step via a Natural Language Processing (NLP)-dependent model, using a modified combination of n-grams and skip-grams (m-NGSG). A meta-comparison of cross-validation accuracy with twelve training datasets from nine different published studies demonstrates a consistent increase in accuracy of m-NGSG when compared to contemporary classification and feature generation models. We expect this model to accelerate the classification of proteins from primary sequence data and increase the accessibility of protein characteristic prediction to a broader range of scientists. m-NGSG is freely available at Bitbucket: https://bitbucket.org/sm_islam/mngsg/src. A web server is available at watson.ecs.baylor.edu/ngsg. erich_baker@baylor.edu. Supplementary data are available at Bioinformatics online.

  18. Bio sorption of some Rare Earth Elements and Yttrium by Gram Positive and Gram Negative Bacteria

    International Nuclear Information System (INIS)

    Ibrahim, H.A.

    2012-01-01

    The separate bio sorption of the REEs La, Sm, Eu and Dy together with yttrium upon the Gram positive bacteria Bacillus subtilis (B.subtilis) and Bacillus Licheniformis (B. Licheniformis),the Gram negative bacterium Escherichia coli (E. coli ) and Saccharomyces cervisiae (Yeast) was studied. The revelant factors of ph 1-6, contact time (30-180 min), the initial rare earth concentration (50-200 mg/l) have been studied. The amount of the accumulated element was strongly affected by its concentration.In addition, bio sorptive fractionation of Y and the studied REEs from a solution containing a mixture of these elements was also studied. From the obtained data, it was found that Langmuir isotherm model for both B.licheniformis and E.coli gives a best fit for the studied elements over the working range of concentration (50-200 mg/I). Transmission electron microscopy exhibited accumulation throughout the bacterial cell with some granular deposits in both the cell periphery and cytoplasm

  19. Patterns of Storage, Synthesis and Changing Light Levels Revealed by Carbon Isotope Microsampling within Eocene Metasequoia Tree Rings

    Science.gov (United States)

    Jahren, H.; Sternberg, L.

    2005-12-01

    Fossil tree rings from Axel Heiberg Island were microanalyzed for δ13C value in order to assess patterns of tree growth and carbon storage within the Middle Eocene (~45 Ma) Arctic paleoenvironment. Wood from four Metasequoia-type individuals was subsampled for analysis: each individual fossil consisted of between 4 and 10 large (~1 cm thick) consecutive tree rings. One of the fossils displayed an obvious concentric pattern, allowing for the determination of the direction of growth with isotopic pattern. Each ring was divided into ~1 mm thick subsamples, resulting in 5-10 δ13C value determinations per period of ring growth (i.e., growing season). All rings revealed a distinct pattern that was characteristic across growing seasons and across individual fossils. Early in the season, δ13C was at its highest value but descended systematically and sharply to its lowest value at the end of the growing season. Total decrease ranged between 3 and 5 ‰ over the course of each growing season. Identical patterns were observed in the δ13C value of alpha-cellulose isolated from each subsample, indicating that the trends observed did not represent changing levels of secondary metabolites, but rather a seasonal adjustment in the bulk source of carbon used during biosynthesis. Our results are consistent with the following annual pattern of wood synthesis 1.) complete dependence on the mobilization of stored carbon compounds early in the growing season; 2.) systematically increasing use of actively-acquired photosynthate during the growing season; 3.) complete reliance on active photosynthate by the end of the growing season. An additional and significant source of 13C discrimination is declining light levels late in the growing season, and likely contributes to the extreme pattern of δ13C decrease seen across each ring. Our results mimic those seen from modern broadleaf deciduous trees (Helle & Schlesser 2004), but differ from those seen in modern conifers (Barbour et al 2002

  20. Feeding Unprotected CLA Methyl Esters Compared to Sunflower Seeds Increased Milk CLA Level but Inhibited Milk Fat Synthesis in Cows

    Directory of Open Access Journals (Sweden)

    F. Dohme-Meier

    2012-01-01

    Full Text Available An experiment was conducted to compare the effect of the same amount of 18:2 offered either as 18:2n-6 or as a mixture of unprotected 18:2c9t11 and 18:2t10c12 on feed intake, milk components as well as plasma and milk fatty acid profile. Fifteen cows were blocked by milk yield and milk fat percentage and within block assigned randomly to 1 of 3 treatments (n = 5. Each cow passed a 12-d adjustment period (AP on a basal diet. After the AP cows received 1 of 3 supplements during an 18-d experimental period (EP. The supplements contained either 1.0 kg ground sunflower seeds (S, 0.5 kg conjugated linoleic acid (CLA-oil (C or 0.75 kg of a mixture of ground sunflower seeds and CLA-oil (2:1; SC. All 3 supplements contained the same amount of 18:2 either as CLA (∑18:2c9t11+18:2t10c12, 1:1 or as 18:2c9c12. During the last 2 d of AP and the last 4 d of EP feed intake and milk yield were recorded daily and milk samples were collected at each milking. Blood samples were collected from the jugular vein on d 11 of AP and d 15 and 18 of EP. The 18:2 intake increased in all treatments from AP to EP. Regardless of the amount of supplemented CLA, the milk fat percentage decreased by 2.35 and 2.10%-units in treatment C and SC, respectively, whereas in the treatment S the decrease was with 0.99%-unit less pronounced. Thus, C and SC cows excreted daily a lower amount of milk fat than S cows. The concentration of trans 18:1 in the plasma and the milk increased from AP to EP and increased with increasing dietary CLA supply. While the concentration of 18:2c9t11 and 18:2t10c12 in the plasma and that of 18:2t10c12 in the milk paralleled dietary supply, the level of 18:2c9t11 in the milk was similar in C and CS but still lower in S. Although the dietary concentration of CLA was highest in treatment C, the partial replacement of CLA by sunflower seeds had a similar inhibitory effect on milk fat synthesis. Comparable 18:2c9t11 levels in the milk in both CLA treatments

  1. [Usefulness of sputum Gram staining in community-acquired pneumonia].

    Science.gov (United States)

    Sato, Tadashi; Aoshima, Masahiro; Ohmagari, Norio; Tada, Hiroshi; Chohnabayashi, Naohiko

    2002-07-01

    To evaluate the usefulness of sputum gram staining in community-acquired pneumonia (CAP), we reviewed 144 cases requiring hospitalization in the last 4 years. The sensitivity was 75.5%, specificity 68.2%, positive predictive value 74.1%, negative predictive value 69.8%, positive likelihood ratio 2.37, negative likelihood ratio 0.36 and accuracy 72.2% in 97 cases. Both sputum gram staining and culture were performed. Concerning bacterial pneumonia (65 cases), we compared the Gram staining group (n = 33), which received initial antibiotic treatment, based on sputum gram staining with the Empiric group (n = 32) that received antibiotics empirically. The success rates of the initial antibiotic treatment were 87.9% vs. 78.1% (P = 0.473); mean hospitalization periods were 9.67 vs. 11.75 days (P = 0.053); and periods of intravenous therapy were 6.73 vs. 7.91 days (P = 0.044), respectively. As for initial treatment, penicillins were used in the Gram staining group more frequently (P gram staining is useful for the shortening of the treatment period and the appropriate selection of initial antibiotics in bacterial pneumonia. We believe, therefore, that sputum gram staining is indispensable as a diagnostic tool CAP.

  2. Comparing Medline citations using modified N-grams

    Science.gov (United States)

    Nawab, Rao Muhammad Adeel; Stevenson, Mark; Clough, Paul

    2014-01-01

    Objective We aim to identify duplicate pairs of Medline citations, particularly when the documents are not identical but contain similar information. Materials and methods Duplicate pairs of citations are identified by comparing word n-grams in pairs of documents. N-grams are modified using two approaches which take account of the fact that the document may have been altered. These are: (1) deletion, an item in the n-gram is removed; and (2) substitution, an item in the n-gram is substituted with a similar term obtained from the Unified Medical Language System  Metathesaurus. N-grams are also weighted using a score derived from a language model. Evaluation is carried out using a set of 520 Medline citation pairs, including a set of 260 manually verified duplicate pairs obtained from the Deja Vu database. Results The approach accurately detects duplicate Medline document pairs with an F1 measure score of 0.99. Allowing for word deletions and substitution improves performance. The best results are obtained by combining scores for n-grams of length 1–5 words. Discussion Results show that the detection of duplicate Medline citations can be improved by modifying n-grams and that high performance can also be obtained using only unigrams (F1=0.959), particularly when allowing for substitutions of alternative phrases. PMID:23715801

  3. Genetic diversity in green gram [Vigna radiata (L.)] landraces ...

    African Journals Online (AJOL)

    GRACE

    2006-07-03

    Jul 3, 2006 ... nitrogen fixer for maintaining soil fertility. However ... use of radioactive elements makes it more costly and tedious. ... Figure 1. Geographic distribution of sampling localities of wild green gram in Southern Tamil Nadu, India.

  4. LexGram - a practical categorial grammar formalism -

    OpenAIRE

    Koenig, Esther

    1995-01-01

    We present the LexGram system, an amalgam of (Lambek) categorial grammar and Head Driven Phrase Structure Grammar (HPSG), and show that the grammar formalism it implements is a well-structured and useful tool for actual grammar development.

  5. Volatile metabolites from some gram-negative bacteria

    DEFF Research Database (Denmark)

    Schöller, Charlotte; Molin, Søren; Wilkins, Ken

    1997-01-01

    A survey of volatile organic compounds (VOCs) excreted from various Gram-negative bacteria (Pseudomonas spp., Serratia spp. and Enterobacter spp.) was carried out. Compounds were identified by gas chromatography-mass spectrometry. VOCs identified included dimethyl disulphide, dimethyl trisulphide...

  6. leaves extracts as counter stain in gram staining reaction 56

    African Journals Online (AJOL)

    DR. AMINU

    is a stain with color contrasting to the principal stain, making the stained ... technology today, the Gram's staining method remains ... was aimed at employing the use of Henna leaves extract as ... fragrant, white or rose flowers in clusters. It is.

  7. Pulmonary infiltrates during community acquired Gram-negative bacteremia

    DEFF Research Database (Denmark)

    Fjeldsøe-Nielsen, Hans; Gjeraa, Kirsten; Berthelsen, Birgitte G

    2013-01-01

    The primary aim of this study was to describe the frequency of pulmonary infiltrates on chest X-ray (CXR) during community acquired Gram-negative bacteremia at a single centre in Denmark.......The primary aim of this study was to describe the frequency of pulmonary infiltrates on chest X-ray (CXR) during community acquired Gram-negative bacteremia at a single centre in Denmark....

  8. Selective bowel decontamination results in gram-positive translocation.

    Science.gov (United States)

    Jackson, R J; Smith, S D; Rowe, M I

    1990-05-01

    Colonization by enteric gram-negative bacteria with subsequent translocation is believed to be a major mechanism for infection in the critically ill patient. Selective bowel decontamination (SBD) has been used to control gram-negative infections by eliminating these potentially pathogenic bacteria while preserving anaerobic and other less pathogenic organisms. Infection with gram-positive organisms and anaerobes in two multivisceral transplant patients during SBD led us to investigate the effect of SBD on gut colonization and translocation. Twenty-four rats received enteral polymixin E, tobramycin, amphotericin B, and parenteral cefotaxime for 7 days (PTA + CEF); 23 received parenteral cefotaxime alone (CEF), 19 received the enteral antibiotics alone (PTA), 21 controls received no antibiotics. Cecal homogenates, mesenteric lymph node (MLN), liver, and spleen were cultured. Only 8% of the PTA + CEF group had gram-negative bacteria in cecal culture vs 52% CEF, 84% PTA, and 100% in controls. Log Enterococcal colony counts were higher in the PTA + CEF group (8.0 + 0.9) vs controls (5.4 + 0.4) P less than 0.01. Translocation of Enterococcus to the MLN was significantly increased in the PTA + CEF group (67%) vs controls (0%) P less than 0.01. SBD effectively eliminates gram-negative organisms from the gut in the rat model. Overgrowth and translocation of Enterococcus suggests that infection with gram-positive organisms may be a limitation of SBD.

  9. Prediction of lipoprotein signal peptides in Gram-negative bacteria.

    Science.gov (United States)

    Juncker, Agnieszka S; Willenbrock, Hanni; Von Heijne, Gunnar; Brunak, Søren; Nielsen, Henrik; Krogh, Anders

    2003-08-01

    A method to predict lipoprotein signal peptides in Gram-negative Eubacteria, LipoP, has been developed. The hidden Markov model (HMM) was able to distinguish between lipoproteins (SPaseII-cleaved proteins), SPaseI-cleaved proteins, cytoplasmic proteins, and transmembrane proteins. This predictor was able to predict 96.8% of the lipoproteins correctly with only 0.3% false positives in a set of SPaseI-cleaved, cytoplasmic, and transmembrane proteins. The results obtained were significantly better than those of previously developed methods. Even though Gram-positive lipoprotein signal peptides differ from Gram-negatives, the HMM was able to identify 92.9% of the lipoproteins included in a Gram-positive test set. A genome search was carried out for 12 Gram-negative genomes and one Gram-positive genome. The results for Escherichia coli K12 were compared with new experimental data, and the predictions by the HMM agree well with the experimentally verified lipoproteins. A neural network-based predictor was developed for comparison, and it gave very similar results. LipoP is available as a Web server at www.cbs.dtu.dk/services/LipoP/.

  10. Silver enhances antibiotic activity against gram-negative bacteria.

    Science.gov (United States)

    Morones-Ramirez, J Ruben; Winkler, Jonathan A; Spina, Catherine S; Collins, James J

    2013-06-19

    A declining pipeline of clinically useful antibiotics has made it imperative to develop more effective antimicrobial therapies, particularly against difficult-to-treat Gram-negative pathogens. Silver has been used as an antimicrobial since antiquity, yet its mechanism of action remains unclear. We show that silver disrupts multiple bacterial cellular processes, including disulfide bond formation, metabolism, and iron homeostasis. These changes lead to increased production of reactive oxygen species and increased membrane permeability of Gram-negative bacteria that can potentiate the activity of a broad range of antibiotics against Gram-negative bacteria in different metabolic states, as well as restore antibiotic susceptibility to a resistant bacterial strain. We show both in vitro and in a mouse model of urinary tract infection that the ability of silver to induce oxidative stress can be harnessed to potentiate antibiotic activity. Additionally, we demonstrate in vitro and in two different mouse models of peritonitis that silver sensitizes Gram-negative bacteria to the Gram-positive-specific antibiotic vancomycin, thereby expanding the antibacterial spectrum of this drug. Finally, we used silver and antibiotic combinations in vitro to eradicate bacterial persister cells, and show both in vitro and in a mouse biofilm infection model that silver can enhance antibacterial action against bacteria that produce biofilms. This work shows that silver can be used to enhance the action of existing antibiotics against Gram-negative bacteria, thus strengthening the antibiotic arsenal for fighting bacterial infections.

  11. Glycosphingolipid synthesis inhibitor AMP-DNM lowers plasma cholesterol levels by promoting fecal cholesterol excretion without inhibiting cholesterol absorption

    NARCIS (Netherlands)

    Vrins, Carlos L. J.; Bietrix, Florence; Lombardo, Elisa; van Roomen, Cindy P. A. A.; Ottenhoff, Roelof; Overkleeft, Herman S.; Aerts, Johannes M.

    2012-01-01

    Inhibition of glycosphingolipid synthesis with iminosugar N-(5'-adamantane-1'-yl-methoxy)-pentyl-1-deoxynojirimycin (AMP-DNM) increases fecal neutral sterol output in mice. To investigate which pathways were involved in this increase, C57BI/6J mice were treated with AMP-DNM and/or ezetimibe. Fecal

  12. Chemical reactivity of precursor materials during synthesis of glasses used for conditioning high-level radioactive waste: Experiments and models

    International Nuclear Information System (INIS)

    Monteiro, A.

    2012-01-01

    The glass used to store high-level radioactive waste is produced by reaction of a solid waste residue and a glassy precursor (glass frit). The waste residue is first dried and calcined (to lose water and nitrogen respectively), then mixed with the glass frit to enable vitrification at high temperature. In order to obtain a good quality glass of constant composition upon cooling, the chemical reactions between the solid precursors must be complete while in the liquid state, to enable incorporation of the radioactive elements into the glassy matrix. The physical and chemical conditions during glass synthesis (e.g. temperature, relative proportions of frit and calcine, amount of radioactive charge) are typically empirically adjusted to obtain a satisfactory final product. The aim of this work is to provide new insights into the chemical and physical interactions that take place during vitrification and to provide data for a mathematical model that has been developed to simulate the chemical reactions. The consequences of the different chemical reactions that involve solid, liquid and gaseous phases are described (thermal effects, changes in crystal morphology and composition, variations in melt properties and structure). In a first series of experiments, a simplified analogue of the calcine (NaNO 3 -Al 2 O 3 ± MoO 3 /Nd 2 O 3 ) has been studied. In a second series of experiments, the simplified calcines have been reacted with a simplified glass frit (SiO 2 -Na 2 O-B 2 O 3 -Al 2 O 3 ) at high temperature. The results show that crystallization of the calcine may take place before interaction with the glass frit, but that the reactivity with the glass at high temperature is a function of the nature and stoichiometry of the crystalline phases which form at low temperature. The results also highlight how the mixing of the starting materials, the physical properties of the frit (viscosity, glass transition temperature) and the Na 2 O/Al 2 O 3 of the calcine but also its

  13. Enhancement of the synthesis of RpoN, Cra, and H-NS by polyamines at the level of translation in Escherichia coli cultured with glucose and glutamate.

    Science.gov (United States)

    Terui, Yusuke; Higashi, Kyohei; Taniguchi, Shiho; Shigemasa, Ai; Nishimura, Kazuhiro; Yamamoto, Kaneyoshi; Kashiwagi, Keiko; Ishihama, Akira; Igarashi, Kazuei

    2007-03-01

    Proteins whose synthesis is enhanced by polyamines at the level of translation were identified in a polyamine-requiring mutant cultured in the presence of 0.1% glucose and 0.02% glutamate instead of 0.4% glucose as an energy source. Under these conditions, enhancement of cell growth by polyamines was almost the same as that in the presence of 0.4% glucose. It was found that synthesis of RpoN, Cra, and H-NS was enhanced by polyamines at the level of translation at the early logarithmic phase of growth (A(540) of 0.15). The effects of polyamines on synthesis of RpoN, H-NS, and Cra were due to the existence of unusual Shine-Dalgarno sequences (RpoN and H-NS) and an inefficient GUG initiation codon (Cra) in their mRNAs. Thus, rpoN, cra, and hns genes were identified as new members of the polyamine modulon. Because most of the polyamine modulon genes thus far identified encode transcription factors (RpoS [sigma(38)], Cya, FecI [sigma(18)], Fis, RpoN [sigma(54)], Cra, and H-NS), DNA microarray analysis of mRNA expressed in cells was performed. At the early logarithmic phase of growth, a total of 97 species of mRNAs that were up-regulated by polyamines more than twofold were under the control of seven polyamine modulon genes mentioned above.

  14. Effect of inclusion of different levels of silage on rumen microbial population and microbial protein synthesis in dairy steers fed on rice straw

    Directory of Open Access Journals (Sweden)

    Thien Truong Giang Nguyen

    2017-02-01

    Full Text Available Objective Leucaena leucocephala (Leucaena is a perennial tropical legume that can be directly grazed or harvested and offered to ruminants as hay, silage, or fresh. However, Leucaena contain phenolic compounds, which are considered anti-nutritional factors as these may reduce intake, digestibility and thus animal performance. Therefore, the objective of this experiment was to determine effects of Leucaena silage (LS feeding levels on rumen microbial populations, N-balance and microbial protein synthesis in dairy steers. Methods Four, rumen fistulated dairy steers with initial weight of 167±12 kg were randomly assigned to receive dietary treatments according to a 4×4 Latin square design. Treatments were as followings: T1 = untreated rice straw (RS; Control, T2 = 70% RS+30% LS, T3 = 40% RS+60% LS, and T4 = 100% LS. Dairy steers were fed rice straw and LS ad libitum and supplemented with concentrate at 0.2% of body weight/d. Results Results revealed that the rumen microbial population, especially cellulolytic, proteolytic bacteria and fungal zoospores were enhanced in steers that received 60% of LS (p0.05. Protozoal population was linearly decreased with increasing level of LS (p<0.05. Moreover, N-balance and microbial protein synthesis were enhanced by LS feeding (p<0.05 and were the highest in 60% LS group. Conclusion Based on this study, it could be concluded that replacement of RS with 60% LS significantly improved microbial population and microbial protein synthesis in diary steers.

  15. Gram stain microbiological pattern of upper extremities suppuration at Baptist Medical Centre, Ogbomoso Nigeria: a fifteen month review.

    Science.gov (United States)

    Oke, A J; Olaolorun, D A; Meier, D E; Tarpley, J L

    2011-06-01

    Sixty-eight (68) patients with serious upper extremity suppurative infections, presenting within a period of fifteen (15) months, were prospectively studied clinically, Gram stain of aspirates/pus were performed, specimen cultured, planted, and where indicated glucose levels and haemoglobin genotype determined. Half of the patients had hand infections. Staphylococcus aureus was isolated from thirty-nine (39) patients. Gram Negative bacilli, including Salmonella were more isolated from patients with diabetes mellitus or Hgb SS or SC. The Gram stain results correlated with the culture result 90%. When Gram Positive cocci were demonstrated in the primary microscopic examination, cultures were not mandatory. When no organism was demonstrated on primary Gram stain or the patient was diabetic or a sickler, cultures of the specimens were done. The Gram stain, well performed, remains a useful, inexpensive, technologically appropriate laboratory test for abetting decision making in patients with upper extremity suppurative infections. Organisms encountered in this study included: Staphylococcus aureus, Streptococcus pyogenes, Salmonella typhi, Proteus mirabilis, Pseudomonas aeruginosa, and Coliforms.

  16. Changes in plasma melatonin levels and pineal organ melatonin synthesis following acclimation of rainbow trout (Oncorhynchus mykiss) to different water salinities.

    Science.gov (United States)

    López-Patiño, Marcos A; Rodríguez-Illamola, Arnau; Gesto, Manuel; Soengas, José L; Míguez, Jesús M

    2011-03-15

    Melatonin has been suggested to play a role in fish osmoregulation, and in salmonids has been related to the timing of adaptive mechanisms during smolting. It has been described that acclimation to different environmental salinities alters levels of circulating melatonin in a number of fish species, including rainbow trout. However, nothing is known regarding salinity effects on melatonin synthesis in the pineal organ, which is the main source of rhythmically produced and secreted melatonin in blood. In the present study we have evaluated, in rainbow trout, the effects of acclimation to different salinities on day and night plasma melatonin values and pineal organ melatonin synthesis. Groups of freshwater (FW)-adapted rainbow trout were placed in tanks with four different levels of water salinity (FW, 6, 12, 18 p.p.t.; parts per thousand) and maintained for 6 h or 5 days. Melatonin content in plasma and pineal organs, as well as the pineal content of serotonin (5-HT) and its main oxidative metabolite (5-hydroxyindole-3-acetic acid; 5-HIAA) were measured by high performance liquid chromatography. In addition, day-night changes in pineal organ arylalkylamine N-acetyltransferase (AANAT2) activity and aanat2 gene expression were studied. Plasma osmolalities were found to be higher in rainbow trout exposed to all salinity levels compared with the control FW groups. A salinity-dependent increase in melatonin content was found in both plasma and pineal organs. This effect was observed during the night, and was related to an increase in aanat2 mRNA abundance and AANAT2 enzyme activity, both of which also occurred during the day. Also, the levels of indoles (5-HT, 5-HIAA) in the pineal organ were negatively affected by increasing water salinity, which seems to be related to the higher recruitment of 5-HT as a substrate for the increased melatonin synthesis. A stimulatory effect of salinity on pineal aanat2 mRNA expression was also identified. These results indicate that

  17. Chlorophyll Synthase under Epigenetic Surveillance Is Critical for Vitamin E Synthesis, and Altered Expression Affects Tocopherol Levels in Arabidopsis1[OPEN

    Science.gov (United States)

    Zhang, Chunyu; Zhang, Wei; Ren, Guodong; Li, Delin; Cahoon, Rebecca E.; Chen, Ming; Zhou, Yongming; Yu, Bin

    2015-01-01

    Chlorophyll synthase catalyzes the final step in chlorophyll biosynthesis: the esterification of chlorophyllide with either geranylgeranyl diphosphate or phytyl diphosphate (PDP). Recent studies have pointed to the involvement of chlorophyll-linked reduction of geranylgeranyl by geranylgeranyl reductase as a major pathway for the synthesis of the PDP precursor of tocopherols. This indirect pathway of PDP synthesis suggests a key role of chlorophyll synthase in tocopherol production to generate the geranylgeranyl-chlorophyll substrate for geranylgeranyl reductase. In this study, contributions of chlorophyll synthase to tocopherol formation in Arabidopsis (Arabidopsis thaliana) were explored by disrupting and altering expression of the corresponding gene CHLOROPHYLL SYNTHASE (CHLSYN; At3g51820). Leaves from the homozygous chlysyn1-1 null mutant were nearly devoid of tocopherols, whereas seeds contained only approximately 25% of wild-type tocopherol levels. Leaves of RNA interference lines with partial suppression of CHLSYN displayed marked reductions in chlorophyll but up to a 2-fold increase in tocopherol concentrations. Cauliflower mosaic virus35S-mediated overexpression of CHLSYN unexpectedly caused a cosuppression phenotype at high frequencies accompanied by strongly reduced chlorophyll content and increased tocopherol levels. This phenotype and the associated detection of CHLSYN-derived small interfering RNAs were reversed with CHLSYN overexpression in rna-directed rna polymerase6 (rdr6), which is defective in RNA-dependent RNA polymerase6, a key enzyme in sense transgene-induced small interfering RNA production. CHLSYN overexpression in rdr6 had little effect on chlorophyll content but resulted in up to a 30% reduction in tocopherol levels in leaves. These findings show that altered CHLSYN expression impacts tocopherol levels and also, show a strong epigenetic surveillance of CHLSYN to control chlorophyll and tocopherol synthesis. PMID:26048882

  18. Rationalizing the permeation of polar antibiotics into Gram-negative bacteria

    International Nuclear Information System (INIS)

    Scorciapino, Mariano Andrea; Acosta-Gutierrez, Silvia; Benkerrou, Dehbia; D’Agostino, Tommaso; Malloci, Giuliano; Samanta, Susruta; Bodrenko, Igor; Ceccarelli, Matteo

    2017-01-01

    The increasing level of antibiotic resistance in Gram-negative bacteria, together with the lack of new potential drug scaffolds in the pipeline, make the problem of infectious diseases a global challenge for modern medicine. The main reason that Gram-negative bacteria are particularly challenging is the presence of an outer cell-protecting membrane, which is not present in Gram-positive species. Such an asymmetric bilayer is a highly effective barrier for polar molecules. Several protein systems are expressed in the outer membrane to control the internal concentration of both nutrients and noxious species, in particular: (i) water-filled channels that modulate the permeation of polar molecules and ions according to concentration gradients, and (ii) efflux pumps to actively expel toxic compounds. Thus, besides expressing specific enzymes for drugs degradation, Gram-negative bacteria can also resist by modulating the influx and efflux of antibiotics, keeping the internal concentration low. However, there are no direct and robust experimental methods capable of measuring the permeability of small molecules, thus severely limiting our knowledge of the molecular mechanisms that ultimately control the permeation of antibiotics through the outer membrane. This is the innovation gap to be filled for Gram-negative bacteria. This review is focused on the permeation of small molecules through porins, considered the main path for the entry of polar antibiotics into Gram-negative bacteria. A fundamental understanding of how these proteins are able to filter small molecules is a prerequisite to design/optimize antibacterials with improved permeation. The level of sophistication of modern molecular modeling algorithms and the advances in new computer hardware has made the simulation of such complex processes possible at the molecular level. In this work we aim to share our experience and perspectives in the context of a multidisciplinary extended collaboration within the IMI

  19. Rationalizing the permeation of polar antibiotics into Gram-negative bacteria

    Science.gov (United States)

    Scorciapino, Mariano Andrea; Acosta-Gutierrez, Silvia; Benkerrou, Dehbia; D'Agostino, Tommaso; Malloci, Giuliano; Samanta, Susruta; Bodrenko, Igor; Ceccarelli, Matteo

    2017-03-01

    The increasing level of antibiotic resistance in Gram-negative bacteria, together with the lack of new potential drug scaffolds in the pipeline, make the problem of infectious diseases a global challenge for modern medicine. The main reason that Gram-negative bacteria are particularly challenging is the presence of an outer cell-protecting membrane, which is not present in Gram-positive species. Such an asymmetric bilayer is a highly effective barrier for polar molecules. Several protein systems are expressed in the outer membrane to control the internal concentration of both nutrients and noxious species, in particular: (i) water-filled channels that modulate the permeation of polar molecules and ions according to concentration gradients, and (ii) efflux pumps to actively expel toxic compounds. Thus, besides expressing specific enzymes for drugs degradation, Gram-negative bacteria can also resist by modulating the influx and efflux of antibiotics, keeping the internal concentration low. However, there are no direct and robust experimental methods capable of measuring the permeability of small molecules, thus severely limiting our knowledge of the molecular mechanisms that ultimately control the permeation of antibiotics through the outer membrane. This is the innovation gap to be filled for Gram-negative bacteria. This review is focused on the permeation of small molecules through porins, considered the main path for the entry of polar antibiotics into Gram-negative bacteria. A fundamental understanding of how these proteins are able to filter small molecules is a prerequisite to design/optimize antibacterials with improved permeation. The level of sophistication of modern molecular modeling algorithms and the advances in new computer hardware has made the simulation of such complex processes possible at the molecular level. In this work we aim to share our experience and perspectives in the context of a multidisciplinary extended collaboration within the IMI

  20. Changing of expression level of fas-antigen (CD95), cytokines synthesis and production after irradiation in low doses

    International Nuclear Information System (INIS)

    Kalinina, N.M.; Solntceva, O.S.; Bytchkova, N.V.; Nikiforov, A.M.

    1997-01-01

    It is known that bone marrow progenitor (CD34+), tymocytes and peripheral blood lymphocytes (PBL) are most radiosensitive than other cell types. Even low doses of radiation induce apoptosis. The investigators suggest that it is possible relationship between synthesis and production of cytokines and apoptotic process. With the purpose to determine correlation between expression of Fas-antigen and synthesis of cytokines after low doses irradiation the experiments by irradiation PBL of healthy persons in vitro were held. Cells were X-irradiated by 12,5, 25 and 50 cGy. In consequence of the experiments increasing of Fas-antigen was revealed. This increasing correlated with changing in synthesis and production of cytokines. Also the Chernobyl's accident liquidators (CAL) were investigated. After comparison data in the group CAL (I) with data in the control group (II) increasing of Fas-antigen expression was revealed. Also in I group was discovered increasing of the cell number sinthesied interleukine-4 (IL-4) and interleukine-6 (IL-6). Interleukine-lβ (IL-1 β) producing pell were decreased. These changes have been correlated with degree of immunodeficiency at CAL. These data allow to consider the apoptosis as cell mechanism included in pathogenesis of diseases, which can be showed later long time after irradiation. (author)

  1. Nitrogen balance, microbial protein synthesis and blood metabolites in fattening of male Bali cattle fed ration with different protein levels in smallholder farms

    Directory of Open Access Journals (Sweden)

    P. K. Tahuk

    2018-03-01

    Full Text Available Research was aimed to determine nitrogen balance, microbial protein synthesis, and blood metabolites of male Bali cattle fattening fed ration with different protein level in smallholder farms North Central Timor, Province of East Timor Tenggara, Indonesia. The cattle used were 18 heads aged 2 to 2.5 years with initial body weight of 229.86±12.46 kg. The cattle were randomly divided into three treatment groups. The T0 group was given feed the same as traditional fattening cattle practices by farmers,T1 group fed ration containing 12% crude protein (CP and 72% total digestible nutrients (TDN, andT2 group fedration containing 15% CP and 72%TDN. Cattle were fed individually for 90 days and drinkingwater ad libitum. The data were analyzedby analysis of variance.Results of research indicated the nitrogen balance, and blood urea nitrogen between T1 and T2 were relatively similar, but those were higher (P<0.05 than T0 . In contrast, microbial proteins synthesis, and blood glucose at 0, 4, and 6 hours before and after feeding were relatively similar between the groups. Blood glucose of T2 at 2 hours after intake were higher (P <0.05 than T0, but was not different with T1 . It can be concluded, that the fattening maleBali cattle fed ration containing 12% CP and 72% TDNimprovedthe nitrogen balance and blood metabolites, butit was no positive effect on the microbial proteins and N synthesis.

  2. Drug-resistant gram-negative uropathogens: A review.

    Science.gov (United States)

    Khoshnood, Saeed; Heidary, Mohsen; Mirnejad, Reza; Bahramian, Aghil; Sedighi, Mansour; Mirzaei, Habibollah

    2017-10-01

    Urinary tract infection(UTI) caused by Gram-negative bacteria is the second most common infectious presentation in community medical practice. Approximately 150 million people are diagnosed with UTI each year worldwide. Drug resistance in Gram-negative uropathogens is a major global concern which can lead to poor clinical outcomes including treatment failure, development of bacteremia, requirement for intravenous therapy, hospitalization, and extended length of hospital stay. The mechanisms of drug resistance in these bacteria are important due to they are often not identified by routine susceptibility tests and have an exceptional potential for outbreaks. Treatment of UTIs depends on the access to effective drugs, which is now threatened by antibiotic resistant Gram-negative uropathogens. Although several effective antibiotics with activity against highly resistant Gram-negatives are available, there is not a unique antibiotic with activity against the high variety of resistance. Therefore, antimicrobial susceptibility tests, correlation between clinicians and laboratories, development of more rapid diagnostic methods, and continuous monitoring of drug resistance are urgent priorities. In this review, we will discuss about the current global status of drug-resistant Gram-negative uropathogens and their mechanisms of drug resistance to provide new insights into their treatment options. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

  3. Gram Scale Syntheses of (-)-Incarvillateine and Its Analogs. Discovery of Potent Analgesics for Neuropathic Pain.

    Science.gov (United States)

    Huang, Bin; Zhang, Fengying; Yu, Gang; Song, Yan; Wang, Xintong; Wang, Meiliang; Gong, Zehui; Su, Ruibin; Jia, Yanxing

    2016-04-28

    (-)-Incarvillateine (INCA) is the major antinociceptive component of Incarvillea sinensis, which has been used to treat rheumatism and relieve pain in traditional Chinese medicine. We have developed a concise and general synthetic approach for INCA, which enabled gram-scale asymmetric syntheses of (-)-INCA, (-)-incarvilline, (-)-isoincarvilline, and six other INCA analogues. The synthesis of isoincarvilline was reported for the first time. Three structurally simplified analogues of INCA were also synthesized. In vivo screening found that INCA and two structurally optimized analogues were efficacious in preventing the acetic acid-induced writhing response. Moreover, their analgesic efficacy was demonstrated in formalin induced pain model. More importantly, administration of 20 or 40 mg/kg INCA and two structurally optimized analogues showed strong analgesic effects in spared nerve injury (SNI) model, and their effective doses were lower than the current gold standard, gabapentin (100 mg/kg in this model).

  4. Effect of Carbohydrate Source and Cottonseed Meal Level in the Concentrate on Feed Intake, Nutrient Digestibility, Rumen Fermentation and Microbial Protein Synthesis in Swamp Buffaloes

    Directory of Open Access Journals (Sweden)

    M. Wanapat

    2013-07-01

    Full Text Available The objective of this study was to investigate the effect of carbohydrate source and cottonseed meal level in the concentrate on feed intake, nutrient digestibility, rumen fermentation and microbial protein synthesis in swamp buffaloes. Four, 4-yr old rumen fistulated swamp buffaloes were randomly assigned to receive four dietary treatments according to a 2×2 factorial arrangement in a 4×4 Latin square design. Factor A was carbohydrate source; cassava chip (CC and CC+rice bran at a ratio 3:1 (CR3:1, and factor B was level of cottonseed meal (CM; 109 g CP/kg (LCM and 328 g CP/kg (HCM in isonitrogenous diets (490 g CP/kg. Buffaloes received urea-treated rice straw ad libitum and supplemented with 5 g concentrate/kg BW. It was found that carbohydrate source did not affect feed intake, nutrient intake, digested nutrients, nutrient digestibility, ammonia nitrogen concentration, fungi and bacterial populations, or microbial protein synthesis (p>0.05. Ruminal pH at 6 h after feeding and the population of protozoa at 4 h after feeding were higher when buffalo were fed with CC than in the CR3:1 treatment (p0.05. Based on this experiment, concentrate with a low level of cottonseed meal could be fed with cassava chips as an energy source in swamp buffalo receiving rice straw.

  5. Trans-generational Immune Priming Protects the Eggs Only against Gram-Positive Bacteria in the Mealworm Beetle

    Science.gov (United States)

    Dubuffet, Aurore; Zanchi, Caroline; Boutet, Gwendoline; Moreau, Jérôme; Teixeira, Maria; Moret, Yannick

    2015-01-01

    In many vertebrates and invertebrates, offspring whose mothers have been exposed to pathogens can exhibit increased levels of immune activity and/or increased survival to infection. Such phenomena, called “Trans-generational immune priming” (TGIP) are expected to provide immune protection to the offspring. As the offspring and their mother may share the same environment, and consequently similar microbial threats, we expect the immune molecules present in the progeny to be specific to the microbes that immune challenged the mother. We provide evidence in the mealworm beetle Tenebrio molitor that the antimicrobial activity found in the eggs is only active against Gram-positive bacteria, even when females were exposed to Gram-negative bacteria or fungi. Fungi were weak inducers of TGIP while we obtained similar levels of anti-Gram-positive activity using different bacteria for the maternal challenge. Furthermore, we have identified an antibacterial peptide from the defensin family, the tenecin 1, which spectrum of activity is exclusively directed toward Gram-positive bacteria as potential contributor to this antimicrobial activity. We conclude that maternal transfer of antimicrobial activity in the eggs of T. molitor might have evolved from persistent Gram-positive bacterial pathogens between insect generations. PMID:26430786

  6. Trans-generational Immune Priming Protects the Eggs Only against Gram-Positive Bacteria in the Mealworm Beetle.

    Directory of Open Access Journals (Sweden)

    Aurore Dubuffet

    2015-10-01

    Full Text Available In many vertebrates and invertebrates, offspring whose mothers have been exposed to pathogens can exhibit increased levels of immune activity and/or increased survival to infection. Such phenomena, called "Trans-generational immune priming" (TGIP are expected to provide immune protection to the offspring. As the offspring and their mother may share the same environment, and consequently similar microbial threats, we expect the immune molecules present in the progeny to be specific to the microbes that immune challenged the mother. We provide evidence in the mealworm beetle Tenebrio molitor that the antimicrobial activity found in the eggs is only active against Gram-positive bacteria, even when females were exposed to Gram-negative bacteria or fungi. Fungi were weak inducers of TGIP while we obtained similar levels of anti-Gram-positive activity using different bacteria for the maternal challenge. Furthermore, we have identified an antibacterial peptide from the defensin family, the tenecin 1, which spectrum of activity is exclusively directed toward Gram-positive bacteria as potential contributor to this antimicrobial activity. We conclude that maternal transfer of antimicrobial activity in the eggs of T. molitor might have evolved from persistent Gram-positive bacterial pathogens between insect generations.

  7. Suetônio, dos gramáticos

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    Marcos Martinho

    2014-12-01

    Full Text Available O Dos gramáticos de Suetônio divide-se em duas partes: na primeira, o autor narra a introdução, desenvolvimento, florescimento e declínio da gramática em Roma (1-4; na segunda, expõe a biografia de vinte professores de gramática, que ensinaram na Cidade entre o início do séc.  I a.C. e meados do século seguinte (5-24. Quanto à primeira parte, procuro mostrar que Suetônio adota conceitos fisicistas ou naturalistas para narrar a história da gramática em Roma, de modo que aquela se possa comparar à vida de um ser vivo. Assim, a exposição de Suetônio revela-se, na verdade, antes biográfica que historicista. Quanto à segunda parte, procuro mostrar que o Biógrafo se interessa por gramáticos que não só escreveram sobre sua arte no ócio, mas a ensinaram por ofício, isto é, por professores de gramática. Daí, seleciono e comento os elementos narrativos relacionados à docência, a saber: os métodos de ensino, o lugar de ensino, o número e qualidade dos alunos, os preços e honorários dos professores. Por fim, apresento tradução anotada do texto de Suetônio.

  8. Glycosaminoglycans are involved in pathogen adherence to corneal epithelial cells differently for Gram-positive and Gram-negative bacteria

    Directory of Open Access Journals (Sweden)

    Beatriz García

    2016-11-01

    Full Text Available The epithelium of the cornea is continuously exposed to pathogens, and adhesion to epithelial cells is regarded as an essential first step in bacterial pathogenesis. In this article, the involvement of glycosaminoglycans in the adhesion of various pathogenic bacteria to corneal epithelial cells is analyzed. All microorganisms use glycosaminoglycans as receptors, but arranged in different patterns depending on the Gram-type of the bacterium. The heparan sulfate chains of syndecans are the main receptors, though other molecular species also seem to be involved, particularly in Gram-negative bacteria. Adherence is inhibited differentially by peptides, including heparin binding sequences, indicating the participation of various groups of Gram-positive and -negative adhesins. The length of the saccharides produces a major effect, and low molecular weight chains inhibit the binding of Gram-negative microorganisms but increase the adherence of Gram-positives. Pathogen adhesion appears to occur preferentially through sulfated domains, and is very dependent on N- and 6-O-sulfation of the glucosamine residue and, to a lesser extent, 2-O sulfation of uronic acid. These data show the differential use of corneal receptors, which could facilitate the development of new anti-infective strategies.

  9. Different Use of Cell Surface Glycosaminoglycans As Adherence Receptors to Corneal Cells by Gram Positive and Gram Negative Pathogens

    Science.gov (United States)

    García, Beatriz; Merayo-Lloves, Jesús; Rodríguez, David; Alcalde, Ignacio; García-Suárez, Olivia; Alfonso, José F.; Baamonde, Begoña; Fernández-Vega, Andrés; Vazquez, Fernando; Quirós, Luis M.

    2016-01-01

    The epithelium of the cornea is continuously exposed to pathogens, and adhesion to epithelial cells is regarded as an essential first step in bacterial pathogenesis. In this article, the involvement of glycosaminoglycans in the adhesion of various pathogenic bacteria to corneal epithelial cells is analyzed. All microorganisms use glycosaminoglycans as receptors, but arranged in different patterns depending on the Gram-type of the bacterium. The heparan sulfate chains of syndecans are the main receptors, though other molecular species also seem to be involved, particularly in Gram-negative bacteria. Adherence is inhibited differentially by peptides, including heparin binding sequences, indicating the participation of various groups of Gram-positive, and -negative adhesins. The length of the saccharides produces a major effect, and low molecular weight chains inhibit the binding of Gram-negative microorganisms but increase the adherence of Gram-positives. Pathogen adhesion appears to occur preferentially through sulfated domains, and is very dependent on N- and 6-O-sulfation of the glucosamine residue and, to a lesser extent, 2-O sulfation of uronic acid. These data show the differential use of corneal receptors, which could facilitate the development of new anti-infective strategies. PMID:27965938

  10. Neither Single nor a Combination of Routine Laboratory Parameters can Discriminate between Gram-positive and Gram-negative Bacteremia

    Science.gov (United States)

    Ratzinger, Franz; Dedeyan, Michel; Rammerstorfer, Matthias; Perkmann, Thomas; Burgmann, Heinz; Makristathis, Athanasios; Dorffner, Georg; Loetsch, Felix; Blacky, Alexander; Ramharter, Michael

    2015-01-01

    Adequate early empiric antibiotic therapy is pivotal for the outcome of patients with bloodstream infections. In clinical practice the use of surrogate laboratory parameters is frequently proposed to predict underlying bacterial pathogens; however there is no clear evidence for this assumption. In this study, we investigated the discriminatory capacity of predictive models consisting of routinely available laboratory parameters to predict the presence of Gram-positive or Gram-negative bacteremia. Major machine learning algorithms were screened for their capacity to maximize the area under the receiver operating characteristic curve (ROC-AUC) for discriminating between Gram-positive and Gram-negative cases. Data from 23,765 patients with clinically suspected bacteremia were screened and 1,180 bacteremic patients were included in the study. A relative predominance of Gram-negative bacteremia (54.0%), which was more pronounced in females (59.1%), was observed. The final model achieved 0.675 ROC-AUC resulting in 44.57% sensitivity and 79.75% specificity. Various parameters presented a significant difference between both genders. In gender-specific models, the discriminatory potency was slightly improved. The results of this study do not support the use of surrogate laboratory parameters for predicting classes of causative pathogens. In this patient cohort, gender-specific differences in various laboratory parameters were observed, indicating differences in the host response between genders. PMID:26522966

  11. Synthesis on taking the long term into consideration in the management of high level radioactive wastes. Report nr 293

    International Nuclear Information System (INIS)

    Vaillant, L.; Schneider, T.; Gadbois, S.

    2005-11-01

    The first part of this report proposes a bibliographic synthesis on safety and radiation protection indicators which are used for the assessment of high activity and long-lived waste disposals (conventional indicators, use of radionuclide concentrations or fluxes, and of duration reference), discusses their liability (in relationship with biosphere and meteorology), and discusses their use with respect to the considered time scale. Then, it discusses the expectations of the different stakeholders in Switzerland (the EKRA group), Germany (the AkEnd Committee) and France (stakeholders in Meuse and Haute-Marne)

  12. Intrinsic, adaptive and acquired antimicrobial resistance in Gram-negative bacteria.

    Science.gov (United States)

    Arzanlou, Mohsen; Chai, Wern Chern; Venter, Henrietta

    2017-02-28

    Gram-negative bacteria are responsible for a large proportion of antimicrobial-resistant infections in humans and animals. Among this class of bacteria are also some of the most successful environmental organisms. Part of this success is their adaptability to a variety of different niches, their intrinsic resistance to antimicrobial drugs and their ability to rapidly acquire resistance mechanisms. These mechanisms of resistance are not exclusive and the interplay of several mechanisms causes high levels of resistance. In this review, we explore the molecular mechanisms underlying resistance in Gram-negative organisms and how these different mechanisms enable them to survive many different stress conditions. © 2017 The Author(s). Published by Portland Press Limited on behalf of the Biochemical Society.

  13. Effect of Carbohydrate Sources and Levels of Cotton Seed Meal in Concentrate on Feed Intake, Nutrient Digestibility, Rumen Fermentation and Microbial Protein Synthesis in Young Dairy Bulls

    Directory of Open Access Journals (Sweden)

    M. Wanapat

    2013-04-01

    Full Text Available The objective of this study was to investigate the effect of levels of cottonseed meal with various carbohydrate sources in concentrate on feed intake, nutrient digestibility, rumen fermentation and microbial protein synthesis in dairy bulls. Four, 6 months old dairy bulls were randomly assigned to receive four dietary treatments according to a 2×2 factorial arrangement in a 4×4 Latin square design. Factor A was carbohydrate source; cassava chip (CC and cassava chip+rice bran in the ratio of 3:1 (CR3:1, and factor B was cotton seed meal levels in the concentrate; 109 g CP/kg (LCM and 328 g CP/kg (HCM at similar overall CP levels (490 g CP/kg. Bulls received urea-lime treated rice straw ad libitum and were supplemented with 10 g of concentrate/kg BW. It was found that carbohydrate source and level of cotton seed meal did not have significant effects on ruminal pH, ammonia nitrogen concentration, microbial protein synthesis or feed intake. Animals which received CC showed significantly higher BUN concentration, ruminal propionic acid and butyric acid proportions, while dry matter, organic matter digestibility, populations of total viable bacteria and proteolytic bacteria were lower than those in the CR3:1 treatment. The concentration of total volatile fatty acids was higher in HCM than LCM treatments, while the concentration of butyric acid was higher in LCM than HCM treatments. The population of proteolytic bacteria with the LCM treatments was higher than the HCM treatments; however other bacteria groups were similar among the different levels of cotton seed meal. Bulls which received LCM had higher protein digestibility than those receiving HCM. Therefore, using high levels of cassava chip and cotton seed meal might positively impact on energy and nitrogen balance for the microbial population in the rumen of the young dairy bull.

  14. Case of Mycobacterium tuberculosis meningitis: Gram staining as a useful initial diagnostic clue for tuberculous meningitis.

    Science.gov (United States)

    Kawakami, Sayoko; Kawamura, Yasuyosi; Nishiyama, Kyouhei; Hatanaka, Hiroki; Fujisaki, Ryuichi; Ono, Yasuo; Miyazawa, Yukihisa; Nishiya, Hajime

    2012-12-01

    A 32-year-old man was admitted to our hospital because of fever, headache, and loss of consciousness. Four days before admission, he had had difficulty speaking. On the day of admission, his colleague had found him to be unconscious and lying on his back. He was admitted to our hospital. The temperature at the eardrum was 35.2°C. Neurologic evaluation was negative. Computed tomography (CT) scan of the brain showed slight ventricular enlargement bilaterally. An X-ray film of the chest showed no abnormality. On the second hospital day, neck stiffness was noted. The cerebrospinal fluid (CSF) contained 870 white cells/μl, most of which were neutrophils; the glucose level in the CSF was 10 mg/dl, and the protein level was 140 mg/dl. Stained smears of the CSF, including Gram staining and India-ink preparations, disclosed no microorganisms. Capsular antigen tests for several bacteria were negative. Antimicrobial agents were started. However, by changing the microscope focus slightly while viewing Gram stains of the CSF, we could see brightened and Gram-positive bacilli that had been phagocytosed by neutrophils. This finding suggested the presence of Mycobacterium tuberculosis. Ziehl-Neelsen staining of the CSF and gastric juice revealed anti-acid bacilli. Polymerase chain reaction for M. tuberculosis in the gastric juice was positive. This case showed that Gram staining could be useful as an initial adjunct for the diagnosis of tuberculous meningitis, particularly when the CSF shows predominantly neutrocytic pleocytosis, but no other evidence of bacterial meningitis.

  15. Probing interaction of Gram-positive and Gram-negative bacterial cells with ZnO nanorods

    Energy Technology Data Exchange (ETDEWEB)

    Jain, Aanchal; Bhargava, Richa; Poddar, Pankaj, E-mail: p.poddar@ncl.res.in

    2013-04-01

    In the present work, the physiological effects of the ZnO nanorods on the Gram positive (Staphylococcus aureus and Bacillus subtilis) and Gram-negative (Escherichia coli and Aerobacter aerogenes) bacterial cells have been studied. The analysis of bacterial growth curves for various concentrations of ZnO nanorods indicates that Gram positive and Gram negative bacterial cells show inhibition at concentrations of ∼ 64 and ∼ 256 μg/mL respectively. The marked difference in susceptibility towards nanorods was also validated by spread plate and disk diffusion methods. In addition, the scanning electron micrographs show a clear damage to the cells via changed morphology of the cells from rod to coccoid etc. The confocal optical microscopy images of these cells also demonstrate the reduction in live cell count in the presence of ZnO nanorods. These, results clearly indicate that the antibacterial activity of ZnO nanorods is higher towards Gram positive bacterium than Gram negative bacterium which indicates that the structure of the cell wall might play a major role in the interaction with nanostructured materials and shows high sensitivity to the particle concentration. Highlights: ► Effect of ZnO nanorods on the growth cycles of four bacterial strains. ► A relation has been established between growth rate of bacteria and concentration. ► Serious damage in the morphology of bacterial cells in the presence of ZnO nanorods. ► Microscopic studies to see the time dependent effect on bacterial cells.

  16. Comparative activity of ceftobiprole against Gram-positive and Gram-negative isolates from Europe and the Middle East: the CLASS study.

    Science.gov (United States)

    Rossolini, Gian M; Dryden, Matthew S; Kozlov, Roman S; Quintana, Alvaro; Flamm, Robert K; Läuffer, Jörg M; Lee, Emma; Morrissey, Ian; CLASS Study Group

    2011-01-01

    to assess the in vitro activity of ceftobiprole and comparators against a recent collection of Gram-positive and Gram-negative pathogens, in order to detect potential changes in susceptibility patterns, and to evaluate the Etest assay for ceftobiprole susceptibility testing. contemporary Gram-positive and Gram-negative isolates (excluding extended-spectrum β-lactamase-producing isolates) from across Europe and the Middle East were collected, and their susceptibility to ceftobiprole, vancomycin, teicoplanin, linezolid, ceftazidime and cefepime was assessed using the Etest method. Quality testing [using Etest and broth microdilution (BMD)] was conducted at a central reference laboratory. some 5041 Gram-positive and 4026 Gram-negative isolates were included. Against Gram-positive isolates overall, ceftobiprole had the lowest MIC50 (0.5 mg/L), compared with 1 mg/L for its comparators (vancomycin, teicoplanin and linezolid). Against methicillin-resistant Staphylococcus aureus, all four agents had a similar MIC90 (2 mg/L), but ceftobiprole had a 4-fold better MIC90 (0.5 mg/L) against methicillin-susceptible strains. Only 38 Gram-positive isolates were confirmed as ceftobiprole resistant. Among Gram-negative strains, 86.9%, 91.7% and 95.2% were susceptible to ceftobiprole, ceftazidime and cefepime, respectively. Pseudomonas aeruginosa was less susceptible to all three antimicrobials than any other Gram-negative pathogen. There was generally good agreement between local Etest results and those obtained at the reference laboratory (for ceftobiprole: 86.8% with Gram-negatives; and 94.7% with Gram-positives), as well as between results obtained by BMD and Etest methods (for ceftobiprole: 98.2% with Gram-negatives; and 98.4% with Gram-positives). ceftobiprole exhibits in vitro activity against a wide range of Gram-positive and Gram-negative pathogens, including multidrug-resistant strains. No changes in its known susceptibility profile were identified.

  17. Kefir consumption does not alter plasma lipid levels or cholesterol fractional synthesis rates relative to milk in hyperlipidemic men: a randomized controlled trial [ISRCTN10820810

    Science.gov (United States)

    St-Onge, Marie-Pierre; Farnworth, Edward R; Savard, Tony; Chabot, Denise; Mafu, Akier; Jones, Peter JH

    2002-01-01

    Background Fermented milk products have been shown to affect serum cholesterol concentrations in humans. Kefir, a fermented milk product, has been traditionally consumed for its potential health benefits but has to date not been studied for its hypocholesterolemic properties. Methods Thirteen healthy mildly hypercholesterolemic male subjects consumed a dairy supplement in randomized crossover trial for 2 periods of 4 wk each. Subjects were blinded to the dairy supplement consumed. Blood samples were collected at baseline and after 4 wk of supplementation for measurement of plasma total, low-density lipoprotein, and high-density lipoprotein cholesterol and triglyceride concentrations, as well as fatty acid profile and cholesterol synthesis rate. Fecal samples were collected at baseline and after 2 and 4 wk of supplementation for determination of fecal short chain fatty acid level and bacterial content. Results Kefir had no effect on total cholesterol, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol or triglyceride concentrations nor on cholesterol fractional synthesis rates after 4 wk of supplementation. No significant change on plasma fatty acid levels was observed with diet. However, both kefir and milk increased (p < 0.05) fecal isobutyric, isovaleric and propionic acids as well as the total amount of fecal short chain fatty acids. Kefir supplementation resulted in increased fecal bacterial content in the majority of the subjects. Conclusions Since kefir consumption did not result in lowered plasma lipid concentrations, the results of this study do not support consumption of kefir as a cholesterol-lowering agent. PMID:11825344

  18. Kefir consumption does not alter plasma lipid levels or cholesterol fractional synthesis rates relative to milk in hyperlipidemic men: a randomized controlled trial [ISRCTN10820810

    Directory of Open Access Journals (Sweden)

    Mafu Akier

    2002-01-01

    Full Text Available Abstract Background Fermented milk products have been shown to affect serum cholesterol concentrations in humans. Kefir, a fermented milk product, has been traditionally consumed for its potential health benefits but has to date not been studied for its hypocholesterolemic properties. Methods Thirteen healthy mildly hypercholesterolemic male subjects consumed a dairy supplement in randomized crossover trial for 2 periods of 4 wk each. Subjects were blinded to the dairy supplement consumed. Blood samples were collected at baseline and after 4 wk of supplementation for measurement of plasma total, low-density lipoprotein, and high-density lipoprotein cholesterol and triglyceride concentrations, as well as fatty acid profile and cholesterol synthesis rate. Fecal samples were collected at baseline and after 2 and 4 wk of supplementation for determination of fecal short chain fatty acid level and bacterial content. Results Kefir had no effect on total cholesterol, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol or triglyceride concentrations nor on cholesterol fractional synthesis rates after 4 wk of supplementation. No significant change on plasma fatty acid levels was observed with diet. However, both kefir and milk increased (p Conclusions Since kefir consumption did not result in lowered plasma lipid concentrations, the results of this study do not support consumption of kefir as a cholesterol-lowering agent.

  19. Characterization and Discrimination of Gram-Positive Bacteria Using Raman Spectroscopy with the Aid of Principal Component Analysis

    Directory of Open Access Journals (Sweden)

    Alia Colniță

    2017-09-01

    Full Text Available Raman scattering and its particular effect, surface-enhanced Raman scattering (SERS, are whole-organism fingerprinting spectroscopic techniques that gain more and more popularity in bacterial detection. In this work, two relevant Gram-positive bacteria species, Lactobacillus casei (L. casei and Listeria monocytogenes (L. monocytogenes were characterized based on their Raman and SERS spectral fingerprints. The SERS spectra were used to identify the biochemical structures of the bacterial cell wall. Two synthesis methods of the SERS-active nanomaterials were used and the recorded spectra were analyzed. L. casei and L. monocytogenes were successfully discriminated by applying Principal Component Analysis (PCA to their specific spectral data.

  20. Diesel degradation and biosurfactant production by Gram-positive ...

    African Journals Online (AJOL)

    The ability of Gram-positive bacteria to degrade diesel increased in a comparable trend as its biosurfactant production increased. The E24 index was highest at 87.6% for isolate D9. Isolates D2, D9 and D10, were identified as Paenibacillus sp. whilst isolate DJLB was found to belong to Stenotrophomonas sp. This study ...

  1. Nicotinoprotein methanol dehydrogenase enzymes in Gram-positive methylotrophic bacteria

    NARCIS (Netherlands)

    Hektor, Harm J.; Kloosterman, Harm; Dijkhuizen, Lubbert

    2000-01-01

    A novel type of alcohol dehydrogenase enzyme has been characterized from Gram-positive methylotrophic (Bacillus methanolicus, the actinomycetes Amycolatopsis methanolica and Mycobacterium gastri) and non-methylotrophic bacteria (Rhodococcus strains). Its in vivo role is in oxidation of methanol and

  2. Prevalence of Gram-negative Pathogens and their antimicrobial ...

    African Journals Online (AJOL)

    The present study was conducted to find out the prevalence and spectrum of Gram negative pathogens causing bacterial meningitis and their antimicrobial susceptibility pattern in a tertiary care hospital. The cerebrospinal fluid (CSF) (3-5 ml) was collected from 638 admitted children clinically suspected of septic meningitis.

  3. Detection of Extended-Spectrum Β-Lactamases among Gram ...

    African Journals Online (AJOL)

    Biochemical tests confirmed the identity of the Gram-negative isolates to be members of the enterobactericeae, which included Klebsiella pneumoniae (60), Escherichia coli (98), Providencia Spp. (32), Morganella moganii (32), Shigella Spp. (14), Citrobacter freundii (14), Serratia marcescens (10), Salmonella paratyphi A ...

  4. Endocarditis : Effects of routine echocardiography during Gram-positive bacteraemia

    NARCIS (Netherlands)

    Vos, F J; Bleeker-Rovers, C P; Sturm, P D; Krabbe, P F M; van Dijk, A P J; Oyen, W J G; Kullberg, B J

    2011-01-01

    BACKGROUND: Despite firm recommendations to perform echocardiography in high-risk patients with Gram-positive bacteraemia, routine echocardiography is not embedded in daily practice in many settings. The aim of this study was to evaluate whether a regime including routine echocardiography results in

  5. NDM 1 Gene Carrying Gram negative Bacteria Isolated from Rats ...

    African Journals Online (AJOL)

    In this study, we screened 56 Gram negative bacteria comprising: 3 isolates of Enterobacter ludwigii, 30 Pseudomonas aeruginosa, 22 Proteus mirabilis, and 1 Aeromonas caviae isolated from oral cavity and rectum of rats captured from commercial poultry houses in Ibadan, Oyo State, Nigeria that were resistant to at least ...

  6. Sinus surgery postpones chronic gram-negative lung infection

    DEFF Research Database (Denmark)

    Alanin, M C; Aanaes, K; Høiby, N

    2016-01-01

    Background: In patients with cystic fibrosis (CF) the sinuses are a bacterial reservoir for Gram-negative bacteria (GNB). From the sinuses the GNB can repeatedly migrate to the lungs. In a one-year follow-up study, endoscopic sinus surgery (ESS) with adjuvant therapy reduced the frequency...

  7. Horse gram- an underutilized nutraceutical pulse crop: a review.

    Science.gov (United States)

    Prasad, Saroj Kumar; Singh, Manoj Kumar

    2015-05-01

    Horse gram is an underutilized pulse crop grown in wide range of adverse climatic conditions. It occupies an important place in human nutrition and has rich source of protein, minerals, and vitamins. Besides nutritional importance, it has been linked to reduced risk of various diseases due to presence of non-nutritive bioactive substances. These bioactive substances such as phytic acid, phenolic acid, fiber, enzymatic/proteinase inhibitors have significant metabolic and/or physiological effects. The importance of horse gram was well recognized by the folk/alternative/traditional medicine as a potential therapeutic agent to treat kidney stones, urinary diseases, piles, common cold, throat infection, fever etc. The inception of nutraceutical concept and increasing health consciousness the demand of nutraceutical and functional food is increased. In recent years, isolation and utilization of potential antioxidants from legumes including horse gram are increased as it decreases the risk of intestinal diseases, diabetes, coronary heart disease, prevention of dental caries etc. Keeping in view the increasing demand of food having nutraceutical values, the present review ascribed with recent scientific knowledge towards the possibilities of exploring the horse gram, as a source of food and nutraceuticals compounds.

  8. Biosorption of mercury by capsulated and slime layerforming Gram ...

    African Journals Online (AJOL)

    The biosorption of mercury by two locally isolated Gram-ve bacilli: Klebsiella pneumoniae ssp. pneumonia (capsulated) and slime layer forming Pseudomonas aeruginosa, was characterized. Mercury adsorption was found to be influenced by the pH value of the biosorption solution, initial metal concentration, amount of the ...

  9. Prediction of lipoprotein signal peptides in Gram-negative bacteria

    DEFF Research Database (Denmark)

    Juncker, Agnieszka; Willenbrock, Hanni; Von Heijne, G.

    2003-01-01

    A method to predict lipoprotein signal peptides in Gram-negative Eubacteria, LipoP, has been developed. The hidden Markov model (HMM) was able to distinguish between lipoproteins (SPaseII-cleaved proteins), SPaseI-cleaved proteins, cytoplasmic proteins, and transmembrane proteins. This predictor ...

  10. System-Level Modeling and Synthesis Techniques for Flow-Based Microfluidic Very Large Scale Integration Biochips

    DEFF Research Database (Denmark)

    Minhass, Wajid Hassan

    Microfluidic biochips integrate different biochemical analysis functionalities on-chip and offer several advantages over the conventional biochemical laboratories. In this thesis, we focus on the flow-based biochips. The basic building block of such a chip is a valve which can be fabricated at very...... propose a framework for mapping the biochemical applications onto the mVLSI biochips, binding and scheduling the operations and performing fluid routing. A control synthesis framework for determining the exact valve activation sequence required to execute the application is also proposed. In order...... to reduce the macro-assembly around the chip and enhance chip scalability, we propose an approach for the biochip pin count minimization. We also propose a throughput maximization scheme for the cell culture mVLSI biochips, saving time and reducing costs. We have extensively evaluated the proposed...

  11. Investigation of High-Level Synthesis tools’ applicability to data acquisition systems design based on the CMS ECAL Data Concentrator Card example

    CERN Document Server

    HUSEJKO, Michal; RASTEIRO DA SILVA, Jose Carlos

    2015-01-01

    High-Level Synthesis (HLS) for Field-Programmable Logic Array (FPGA) programming is becoming a practical alternative to well-established VHDL and Verilog languages. This paper describes a case study in the use of HLS tools to design FPGA-based data acquisition systems (DAQ). We will present the implementation of the CERN CMS detector ECAL Data Concentrator Card (DCC) functionality in HLS and lessons learned from using HLS design flow.The DCC functionality and a definition of the initial system-level performance requirements (latency, bandwidth, and throughput) will be presented. We will describe how its packet processing control centric algorithm was implemented with VHDL and Verilog languages. We will then show how the HLS flow could speed up design-space exploration by providing loose coupling between functions interface design and functions algorithm implementation.We conclude with results of real-life hardware tests performed with the HLS flow-generated design with a DCC Tester system.

  12. Investigation of High-Level Synthesis tools’ applicability to data acquisition systems design based on the CMS ECAL Data Concentrator Card example

    Science.gov (United States)

    HUSEJKO, Michal; EVANS, John; RASTEIRO DA SILVA, Jose Carlos

    2015-12-01

    High-Level Synthesis (HLS) for Field-Programmable Logic Array (FPGA) programming is becoming a practical alternative to well-established VHDL and Verilog languages. This paper describes a case study in the use of HLS tools to design FPGA-based data acquisition systems (DAQ). We will present the implementation of the CERN CMS detector ECAL Data Concentrator Card (DCC) functionality in HLS and lessons learned from using HLS design flow. The DCC functionality and a definition of the initial system-level performance requirements (latency, bandwidth, and throughput) will be presented. We will describe how its packet processing control centric algorithm was implemented with VHDL and Verilog languages. We will then show how the HLS flow could speed up design-space exploration by providing loose coupling between functions interface design and functions algorithm implementation. We conclude with results of real-life hardware tests performed with the HLS flow-generated design with a DCC Tester system.

  13. Antimicrobial Photodynamic Therapy to Kill Gram-negative Bacteria

    Science.gov (United States)

    Sperandio, Felipe F; Huang, Ying-Ying; Hamblin, Michael R

    2013-01-01

    Antimicrobial photodynamic therapy (PDT) or photodynamic inactivation (PDI) is a new promising strategy to eradicate pathogenic microorganisms such as Gram-positive and Gram-negative bacteria, yeasts and fungi. The search for new approaches that can kill bacteria but do not induce the appearance of undesired drug-resistant strains suggests that PDT may have advantages over traditional antibiotic therapy. PDT is a non-thermal photochemical reaction that involves the simultaneous presence of visible light, oxygen and a dye or photosensitizer (PS). Several PS have been studied for their ability to bind to bacteria and efficiently generate reactive oxygen species (ROS) upon photostimulation. ROS are formed through type I or II mechanisms and may inactivate several classes of microbial cells including Gram-negative bacteria such as Pseudomonas aeruginosa, which are typically characterized by an impermeable outer cell membrane that contains endotoxins and blocks antibiotics, dyes, and detergents, protecting the sensitive inner membrane and cell wall. This review covers significant peer-reviewed articles together with US and World patents that were filed within the past few years and that relate to the eradication of Gram-negative bacteria via PDI or PDT. It is organized mainly according to the nature of the PS involved and includes natural or synthetic food dyes; cationic dyes such as methylene blue and toluidine blue; tetrapyrrole derivatives such as phthalocyanines, chlorins, porphyrins, chlorophyll and bacteriochlorophyll derivatives; functionalized fullerenes; nanoparticles combined with different PS; other formulations designed to target PS to bacteria; photoactive materials and surfaces; conjugates between PS and polycationic polymers or antibodies; and permeabilizing agents such as EDTA, PMNP and CaCl2. The present review also covers the different laboratory animal models normally used to treat Gram-negative bacterial infections with antimicrobial PDT. PMID

  14. Monomicrobial necrotizing fasciitis in a single center: the emergence of Gram-negative bacteria as a common pathogen

    Directory of Open Access Journals (Sweden)

    D. Yahav

    2014-11-01

    Conclusions: In our center, 42% of monomicrobial necrotizing fasciitis cases were found to be caused by Gram-negative organisms, mostly E. coli. These infections usually appeared in immunocompromised or postoperative patients, often presented with normal CPK levels, and were associated with high mortality rates.

  15. Gamma ray induced synthesis of superabsorbent hydrogels

    International Nuclear Information System (INIS)

    Ramnani, S.P.; Sabharwal, S.; Rawat, K.P.; Majali, A.B.

    2000-01-01

    The synthesis of superabsorbent gel by grafting of acrylic acid on carboxymethyl cellulose has been carried out using gamma radiation. One gram of this gel absorbs and holds as high as 460 gm of water. The effect of various additives on water absorption characteristics was studied and possible applications of this gel to agriculture are proposed. (author)

  16. Antimicrobial Activities of Leaf Extracts of Guava (Psidium guajava L.) on Two Gram-Negative and Gram-Positive Bacteria

    Science.gov (United States)

    Biswas, Bipul; Rogers, Kimberly; McLaughlin, Fredrick; Yadav, Anand

    2013-01-01

    Aim. To determine the antimicrobial potential of guava (Psidium guajava) leaf extracts against two gram-negative bacteria (Escherichia coli and Salmonella enteritidis) and two gram-positive bacteria (Staphylococcus aureus and Bacillus cereus) which are some of foodborne and spoilage bacteria. The guava leaves were extracted in four different solvents of increasing polarities (hexane, methanol, ethanol, and water). The efficacy of these extracts was tested against those bacteria through a well-diffusion method employing 50 μL leaf-extract solution per well. According to the findings of the antibacterial assay, the methanol and ethanol extracts of the guava leaves showed inhibitory activity against gram-positive bacteria, whereas the gram-negative bacteria were resistant to all the solvent extracts. The methanol extract had an antibacterial activity with mean zones of inhibition of 8.27 and 12.3 mm, and the ethanol extract had a mean zone of inhibition of 6.11 and 11.0 mm against B. cereus and S. aureus, respectively. On the basis of the present finding, guava leaf-extract might be a good candidate in the search for a natural antimicrobial agent. This study provides scientific understanding to further determine the antimicrobial values and investigate other pharmacological properties. PMID:24223039

  17. Antimicrobial Activities of Leaf Extracts of Guava (Psidium guajava L. on Two Gram-Negative and Gram-Positive Bacteria

    Directory of Open Access Journals (Sweden)

    Bipul Biswas

    2013-01-01

    Full Text Available Aim. To determine the antimicrobial potential of guava (Psidium guajava leaf extracts against two gram-negative bacteria (Escherichia coli and Salmonella enteritidis and two gram-positive bacteria (Staphylococcus aureus and Bacillus cereus which are some of foodborne and spoilage bacteria. The guava leaves were extracted in four different solvents of increasing polarities (hexane, methanol, ethanol, and water. The efficacy of these extracts was tested against those bacteria through a well-diffusion method employing 50 μL leaf-extract solution per well. According to the findings of the antibacterial assay, the methanol and ethanol extracts of the guava leaves showed inhibitory activity against gram-positive bacteria, whereas the gram-negative bacteria were resistant to all the solvent extracts. The methanol extract had an antibacterial activity with mean zones of inhibition of 8.27 and 12.3 mm, and the ethanol extract had a mean zone of inhibition of 6.11 and 11.0 mm against B. cereus and S. aureus, respectively. On the basis of the present finding, guava leaf-extract might be a good candidate in the search for a natural antimicrobial agent. This study provides scientific understanding to further determine the antimicrobial values and investigate other pharmacological properties.

  18. Outcomes of single organism peritonitis in peritoneal dialysis: gram negatives versus gram positives in the Network 9 Peritonitis Study.

    Science.gov (United States)

    Bunke, C M; Brier, M E; Golper, T A

    1997-08-01

    The use of the "peritonitis rate" in the management of patients undergoing peritoneal dialysis is assuming importance in comparing the prowess of facilities, care givers and new innovations. For this to be a meaningful outcome measure, the type of infection (causative pathogen) must have less clinical significance than the number of infections during a time interval. The natural history of Staphylococcus aureus, pseudomonas, and fungal peritonitis would not support that the outcome of an episode of peritonitis is independent of the causative pathogen. Could this concern be extended to other more frequently occurring pathogens? To address this, the Network 9 Peritonitis Study identified 530 episodes of single organism peritonitis caused by a gram positive organism and 136 episodes caused by a single non-pseudomonal gram negative (NPGN) pathogen. Coincidental soft tissue infections (exit site or tunnel) occurred equally in both groups. Outcomes of peritonitis were analyzed by organism classification and by presence or absence of a soft tissue infection. NPGN peritonitis was associated with significantly more frequent catheter loss, hospitalization, and technique failure and was less likely to resolve regardless of the presence or absence of a soft tissue infection. Hospitalization and death tended to occur more frequently with enterococcal peritonitis than with other gram positive peritonitis. The outcomes in the NPGN peritonitis group were significantly worse (resolution, catheter loss, hospitalization, technique failure) compared to coagulase negative staphylococcal or S. aureus peritonitis, regardless of the presence or absence of a coincidental soft tissue infection. Furthermore, for the first time, the poor outcomes of gram negative peritonitis are shown to be independent of pseudomonas or polymicrobial involvement or soft tissue infections. The gram negative organism appears to be the important factor. In addition, the outcome of peritonitis caused by S. aureus

  19. A hybrid multi-level optimization approach for the dynamic synthesis/design and operation/control under uncertainty of a fuel cell system

    International Nuclear Information System (INIS)

    Kim, Kihyung; Spakovsky, Michael R. von; Wang, M.; Nelson, Douglas J.

    2011-01-01

    During system development, large-scale, complex energy systems require multi-disciplinary efforts to achieve system quality, cost, and performance goals. As systems become larger and more complex, the number of possible system configurations and technologies, which meet the designer's objectives optimally, increases greatly. In addition, both transient and environmental effects may need to be taken into account. Thus, the difficulty of developing the system via the formulation of a single optimization problem in which the optimal synthesis/design and operation/control of the system are achieved simultaneously is great and rather problematic. This difficulty is further heightened with the introduction of uncertainty analysis, which transforms the problem from a purely deterministic one into a probabilistic one. Uncertainties, system complexity and nonlinearity, and large numbers of decision variables quickly render the single optimization problem unsolvable by conventional, single-level, optimization strategies. To address these difficulties, the strategy adopted here combines a dynamic physical decomposition technique for large-scale optimization with a response sensitivity analysis method for quantifying system response uncertainties to given uncertainty sources. The feasibility of such a hybrid approach is established by applying it to the synthesis/design and operation/control of a 5 kW proton exchange membrane (PEM) fuel cell system.

  20. How bacterial cell division might cheat turgor pressure - a unified mechanism of septal division in Gram-positive and Gram-negative bacteria.

    Science.gov (United States)

    Erickson, Harold P

    2017-08-01

    An important question for bacterial cell division is how the invaginating septum can overcome the turgor force generated by the high osmolarity of the cytoplasm. I suggest that it may not need to. Several studies in Gram-negative bacteria have shown that the periplasm is isoosmolar with the cytoplasm. Indirect evidence suggests that this is also true for Gram-positive bacteria. In this case the invagination of the septum takes place within the uniformly high osmotic pressure environment, and does not have to fight turgor pressure. A related question is how the V-shaped constriction of Gram-negative bacteria relates to the plate-like septum of Gram-positive bacteria. I collected evidence that Gram-negative bacteria have a latent capability of forming plate-like septa, and present a model in which septal division is the basic mechanism in both Gram-positive and Gram-negative bacteria. © 2017 WILEY Periodicals, Inc.

  1. Quantitative determination of sulfur containing wine odorants at sub-ppb levels. 1. Synthesis of the deuterated analogues.

    Science.gov (United States)

    Kotseridis, Y; Ray, J L; Augier, C; Baumes, R

    2000-12-01

    [2H10]-4-Sulfanyl-4-methylpentan-2-one (d10-SMP), [2H2]-3-sulfanylhexan-1-ol (d2-3SH), and [2H5]-3-sulfanylhexyl acetate (d5-3SHAc), the labeled analogues of impact odorants of wines and other foods, were synthesized to be used for the quantitative determination of the natural compounds in white and red wines by stable isotope dilution assay. The sulfidation was achieved by Michael addition, on mesityl oxide or ethyl hex-2-enoate, respectively, of the sulfhydryl anion generated in situ from triphenylsilanethiol and potassium fluoride under phase transfer conditions. The labeling of 4-sulfanyl-4-methylpentan-2-one (SMP) was obtained from the commercial starting material, [2H6]acetone, so that this method could be used to synthesize 13C-labeled SMP from 13C-labeled acetone. The labeling of 3-sulfanylhexan-1-ol (3SH) and 3-sulfanylhexyl acetate (3SHAc) was obtained from reduction with lithium aluminum deuteride of the Michael adduct ethyl 3-sulfanylhexanoate and [2H3]-acetylation. During the synthesis, 3SH and 3SHAc were partially oxidized to their disulfide, which were reduced back to the thiols by an additional reduction step; the tertiary thiol SMP was less sensitive to this oxidation.

  2. The Effect of Charge at the Surface of Silver Nanoparticles on Antimicrobial Activity against Gram-Positive and Gram-Negative Bacteria: A Preliminary Study

    International Nuclear Information System (INIS)

    Abbaszadegan, A.; Ghahramani, Y.; Nabavizadeh, M.; Gholami, A.; Hemmateenejad, I.; Dorostkar, S.; Sharghi, H.

    2014-01-01

    The bactericidal efficiency of various positively and negatively charged silver nanoparticles has been extensively evaluated in literature, but there is no report on efficacy of neutrally charged silver nanoparticles. The goal of this study is to evaluate the role of electrical charge at the surface of silver nanoparticles on antibacterial activity against a panel of microorganisms. Three different silver nanoparticles were synthesized by different methods, providing three different electrical surface charges (positive, neutral, and negative). The antibacterial activity of these nanoparticles was tested against gram-positive (i.e., Staphylococcus aureus, Streptococcus mutans, and Streptococcus pyogenes) and gram-negative (i.e., Escherichia coli and Proteus vulgaris) bacteria. Well diffusion and micro-dilution tests were used to evaluate the bactericidal activity of the nanoparticles. According to the obtained results, the positively-charged silver nanoparticles showed the highest bactericidal activity against all microorganisms tested. The negatively charged silver nanoparticles had the least and the neutral nanoparticles had intermediate antibacterial activity. The most resistant bacteria were Proteus vulgaris. We found that the surface charge of the silver nanoparticles was a significant factor affecting bactericidal activity on these surfaces. Although the positively charged nanoparticles showed the highest level of effectiveness against the organisms tested, the neutrally charged particles were also potent against most bacterial species.

  3. Bovine mastitis caused by gram negative bacteria in Mosul

    Directory of Open Access Journals (Sweden)

    S. Y. A. Al-Dabbagh

    2012-01-01

    Full Text Available A total of 90 milk samples were collected from cows with clinical and subclinical mastitis from different areas in Mosul city, in a period from October 2009 to June 2010, for the detection of gram negative bacteriological causative agents. The bacteria were identified using morphological, cultural and biochemical characteristics. thirty tow (35.3% gram negative bacterial isolates were obtained from the total count which included 14 isolates (15.5% for Escherichia coli, 7 isolates (7.7% for Klebsiella spp, 4 isolates (4.4% for Pseudomonas aeruginosa, 3 isolates (3.3% for Enterobacter aerogenes ,2 isolates for Serratia marcescens and one isolates (1.1% for each of Aeromonas hydrophila and Pasteurella multocida. Results of antibiotic sensitivity test indicated that most of these isolates were sensitive to Ciprofloxacin following by Gentamycin and Cotrimoxazole, while most of these organisms were resistant to Ampicillin, the isolates showed different percentages of sensitivity to Doxycycline, Tetracycline, Neomycin and Chloramphenicol.

  4. Multidrug resistance in enteric and other gram-negative bacteria.

    Science.gov (United States)

    George, A M

    1996-05-15

    In Gram-negative bacteria, multidrug resistance is a term that is used to describe mechanisms of resistance by chromosomal genes that are activated by induction or mutation caused by the stress of exposure to antibiotics in natural and clinical environments. Unlike plasmid-borne resistance genes, there is no alteration or degradation of drugs or need for genetic transfer. Exposure to a single drug leads to cross-resistance to many other structurally and functionally unrelated drugs. The only mechanism identified for multidrug resistance in bacteria is drug efflux by membrane transporters, even though many of these transporters remain to be identified. The enteric bacteria exhibit mostly complex multidrug resistance systems which are often regulated by operons or regulons. The purpose of this review is to survey molecular mechanisms of multidrug resistance in enteric and other Gram-negative bacteria, and to speculate on the origins and natural physiological functions of the genes involved.

  5. Horse gram- an underutilized nutraceutical pulse crop: a review

    OpenAIRE

    Prasad, Saroj Kumar; Singh, Manoj Kumar

    2014-01-01

    Horse gram is an underutilized pulse crop grown in wide range of adverse climatic conditions. It occupies an important place in human nutrition and has rich source of protein, minerals, and vitamins. Besides nutritional importance, it has been linked to reduced risk of various diseases due to presence of non-nutritive bioactive substances. These bioactive substances such as phytic acid, phenolic acid, fiber, enzymatic/proteinase inhibitors have significant metabolic and/or physiological effec...

  6. La Gramática Discursivo-Funcional

    NARCIS (Netherlands)

    Hengeveld, K.; Mackenzie, J.L.

    2011-01-01

    La Gramática Discursivo-Funcional (GDF) es una teoría funcional del lenguaje de inspiración tipológica que presenta una organización descendente (top-down) con el objeto de alcanzar la adecuación psicológica y que toma el Acto Discursivo como unidad básica de análisis para lograr la adecuación

  7. Aluminium-induced excessive ROS causes cellular damage and metabolic shifts in black gram Vigna mungo (L.) Hepper.

    Science.gov (United States)

    Chowra, Umakanta; Yanase, Emiko; Koyama, Hiroyuki; Panda, Sanjib Kumar

    2017-01-01

    Aluminium-induced oxidative damage caused by excessive ROS production was evaluated in black gram pulse crop. Black gram plants were treated with different aluminium (Al 3+ ) concentrations (10, 50 and 100 μM with pH 4.7) and further the effects of Al 3+ were characterised by means of root growth inhibition, histochemical assay, ROS content analysis, protein carbonylation quantification and 1 H-NMR analysis. The results showed that aluminium induces excessive ROS production which leads to cellular damage, root injury, stunt root growth and other metabolic shifts. In black gram, Al 3+ induces cellular damage at the earliest stage of stress which was characterised from histochemical analysis. From this study, it was observed that prolonged stress can activate certain aluminium detoxification defence mechanism. Probably excessive ROS triggers such defence mechanism in black gram. Al 3+ can induce excessive ROS initially in the root region then transported to other parts of the plant. As much as the Al 3+ concentration increases, the rate of cellular injury and ROS production also increases. But after 72 h of stress, plants showed a lowered ROS level and cellular damage which indicates the upregulation of defensive mechanisms. Metabolic shift analysis also showed that the black gram plant under stress has less metabolic content after 24 h of treatment, but gradually, it was increased after 72 h of treatment. It was assumed that ROS played the most important role as a signalling molecule for aluminium stress in black gram.

  8. Antimicrobial activity of metal oxide nanoparticles against Gram-positive and Gram-negative bacteria: a comparative study

    Directory of Open Access Journals (Sweden)

    Azam A

    2012-12-01

    Full Text Available Ameer Azam,1,2 Arham S Ahmed,2 Mohammad Oves,3 Mohammad S Khan,3 Sami S Habib,1 Adnan Memic11Centre of Nanotechnology, King Abdulaziz University, Jeddah, Saudi Arabia; 2Centre of Excellence in Materials Science (Nanomaterials, 3Department of Agricultural Microbiology, Aligarh Muslim University, Aligarh, IndiaBackground: Nanomaterials have unique properties compared to their bulk counterparts. For this reason, nanotechnology has attracted a great deal of attention from the scientific community. Metal oxide nanomaterials like ZnO and CuO have been used industrially for several purposes, including cosmetics, paints, plastics, and textiles. A common feature that these nanoparticles exhibit is their antimicrobial behavior against pathogenic bacteria. In this report, we demonstrate the antimicrobial activity of ZnO, CuO, and Fe2O3 nanoparticles against Gram-positive and Gram-negative bacteria.Methods and results: Nanosized particles of three metal oxides (ZnO, CuO, and Fe2O3 were synthesized by a sol–gel combustion route and characterized by X-ray diffraction, Fourier-transform infrared spectroscopy, and transmission electron microscopy techniques. X-ray diffraction results confirmed the single-phase formation of all three nanomaterials. The particle sizes were observed to be 18, 22, and 28 nm for ZnO, CuO, and Fe2O3, respectively. We used these nanomaterials to evaluate their antibacterial activity against both Gram-negative (Escherichia coli and Pseudomonas aeruginosa and Gram-positive (Staphylococcus aureus and Bacillus subtilis bacteria.Conclusion: Among the three metal oxide nanomaterials, ZnO showed greatest antimicrobial activity against both Gram-positive and Gram-negative bacteria used in this study. It was observed that ZnO nanoparticles have excellent bactericidal potential, while Fe2O3 nanoparticles exhibited the least bactericidal activity. The order of antibacterial activity was demonstrated to be the following: ZnO > CuO > Fe2O3

  9. RNases and Helicases in Gram-Positive Bacteria.

    Science.gov (United States)

    Durand, Sylvain; Condon, Ciaran

    2018-04-01

    RNases are key enzymes involved in RNA maturation and degradation. Although they play a crucial role in all domains of life, bacteria, archaea, and eukaryotes have evolved with their own sets of RNases and proteins modulating their activities. In bacteria, these enzymes allow modulation of gene expression to adapt to rapidly changing environments. Today, >20 RNases have been identified in both Escherichia coli and Bacillus subtilis , the paradigms of the Gram-negative and Gram-positive bacteria, respectively. However, only a handful of these enzymes are common to these two organisms and some of them are essential to only one. Moreover, although sets of RNases can be very similar in closely related bacteria such as the Firmicutes Staphylococcus aureus and B. subtilis , the relative importance of individual enzymes in posttranscriptional regulation in these organisms varies. In this review, we detail the role of the main RNases involved in RNA maturation and degradation in Gram-positive bacteria, with an emphasis on the roles of RNase J1, RNase III, and RNase Y. We also discuss how other proteins such as helicases can modulate the RNA-degradation activities of these enzymes.

  10. Combating multidrug-resistant Gram-negative bacterial infections.

    Science.gov (United States)

    Xu, Ze-Qi; Flavin, Michael T; Flavin, John

    2014-02-01

    Multidrug-resistant (MDR) bacterial infections, especially those caused by Gram-negative pathogens, have emerged as one of the world's greatest health threats. The development of novel antibiotics to treat MDR Gram-negative bacteria has, however, stagnated over the last half century. This review provides an overview of recent R&D activities in the search for novel antibiotics against MDR Gram-negatives. It provides emphasis in three key areas. First, the article looks at new analogs of existing antibiotic molecules such as β-lactams, tetracyclines, and aminoglycoside as well as agents against novel bacterial targets such as aminoacyl-tRNA synthetase and peptide deformylase. Second, it also examines alternative strategies to conventional approaches including cationic antimicrobial peptides, siderophores, efflux pump inhibitors, therapeutic antibodies, and renewed interest in abandoned treatments or those with limited indications. Third, the authors aim to provide an update on the current clinical development status for each drug candidate. The traditional analog approach is insufficient to meet the formidable challenge brought forth by MDR superbugs. With the disappointing results of the genomics approach for delivering novel targets and drug candidates, alternative strategies to permeate the bacterial cell membrane, enhance influx, disrupt efflux, and target specific pathogens via therapeutic antibodies are attractive and promising. Coupled with incentivized business models, governmental policies, and a clarified regulatory pathway, it is hoped that the antibiotic pipeline will be filled with an effective armamentarium to safeguard global health.

  11. Keywords in Context (Using n-grams with Python

    Directory of Open Access Journals (Sweden)

    William J. Turkel

    2012-07-01

    Full Text Available Like in Output Data as HTML File, this lesson takes the frequency pairs collected in Counting Frequencies and outputs them in HTML. This time the focus is on keywords in context (KWIC which creates n-grams from the original document content – in this case a trial transcript from the Old Bailey Online. You can use your program to select a keyword and the computer will output all instances of that keyword, along with the words to the left and right of it, making it easy to see at a glance how the keyword is used. Once the KWICs have been created, they are then wrapped in HTML and sent to the browser where they can be viewed. This reinforces what was learned in Output Data as HTML File, opting for a slightly different output. At the end of this lesson, you will be able to extract all possible n-grams from the text. In the next lesson, you will be learn how to output all of the n-grams of a given keyword in a document downloaded from the Internet, and display them clearly in your browser window.

  12. Microbiology of liver abscesses and the predictive value of abscess gram stain and associated blood cultures.

    Science.gov (United States)

    Chemaly, Roy F; Hall, Gerri S; Keys, Thomas F; Procop, Gary W

    2003-08-01

    Although rare, pyogenic liver abscesses are potentially fatal. We evaluated the predictive value of Gram stain of liver abscess aspirates and temporally associated blood cultures. Gram stains detected bacteria in 79% of the liver abscesses tested. The sensitivity and specificity of Gram stain of the liver abscesses were 90% and 100% for Gram-positive cocci (GPC) and 52% and 94% for Gram-negative bacilli (GNB). The sensitivities of the blood cultures for any GPC and GNB present in the liver abscess were 30% and 39%, respectively. Although, Gram stains and blood cultures offer incomplete detection of the microbial contents of pyogenic liver abscesses, both tests should always accompany liver abscess cultures.

  13. Pentaclethra macroloba tannins fractions active against methicillin-resistant staphylococcal and Gram-negative strains showing selective toxicity

    Directory of Open Access Journals (Sweden)

    Ivana Correa Ramos Leal

    2011-12-01

    Full Text Available The ethanol extract of the vegetal species Pentaclethra macroloba (Willd. Kuntze, Fabaceae, was fractioned and the antibacterial activity was determined. The active ethyl acetate (ea fraction showed activity against Gram-positive (Staphylococcus spp. and Enterococcus spp. and Gram-negative (Pseudomonas aeruginosa, Acinetobacter spp. and Klebsiella pneumoniae multiresistant bacteria. Gallic acid derivatives were identified as the main compounds in inactive subfractions from the ea fraction, while the active one afforded ellagic acid as the major constituent when submitted to acid hydrolysis reaction, which suggests the presence of hydrolysable tannins. The minimum bactericidal concentration analysis showed a bactericide mechanism of action for the tannin subfraction found. The antibacterial mechanism of action of the active tannin subfraction against S. aureus reference strains (ATCC 29213 e 33591 was proposed adopting an in vitro assay of protein synthesis inhibition. For this, bacterial cells were labeled with [35S] methionine in the presence of the subfraction. The protein synthesis inhibition was observed at 256 µg/mL of this subfraction. At this concentration it did not present cytotoxicity in eukaryotic cells by the neutral red technique, suggesting selective toxicity. The present study is the first in vitro investigation of the antibacterial properties of tannin fractions obtained from a polar extract of P. macroloba.

  14. Pentaclethra macroloba tannins fractions active against methicillin-resistant staphylococcal and Gram-negative strains showing selective toxicity

    Directory of Open Access Journals (Sweden)

    Ivana Correa Ramos Leal

    2011-08-01

    Full Text Available The ethanol extract of the vegetal species Pentaclethra macroloba (Willd. Kuntze, Fabaceae, was fractioned and the antibacterial activity was determined. The active ethyl acetate (ea fraction showed activity against Gram-positive (Staphylococcus spp. and Enterococcus spp. and Gram-negative (Pseudomonas aeruginosa, Acinetobacter spp. and Klebsiella pneumoniae multiresistant bacteria. Gallic acid derivatives were identified as the main compounds in inactive subfractions from the ea fraction, while the active one afforded ellagic acid as the major constituent when submitted to acid hydrolysis reaction, which suggests the presence of hydrolysable tannins. The minimum bactericidal concentration analysis showed a bactericide mechanism of action for the tannin subfraction found. The antibacterial mechanism of action of the active tannin subfraction against S. aureus reference strains (ATCC 29213 e 33591 was proposed adopting an in vitro assay of protein synthesis inhibition. For this, bacterial cells were labeled with [35S] methionine in the presence of the subfraction. The protein synthesis inhibition was observed at 256 µg/mL of this subfraction. At this concentration it did not present cytotoxicity in eukaryotic cells by the neutral red technique, suggesting selective toxicity. The present study is the first in vitro investigation of the antibacterial properties of tannin fractions obtained from a polar extract of P. macroloba.

  15. Depletion of polycistronic transcripts using short interfering RNAs: cDNA synthesis method affects levels of non-targeted genes determined by quantitative PCR.

    Science.gov (United States)

    Hanning, Jennifer E; Groves, Ian J; Pett, Mark R; Coleman, Nicholas

    2013-05-21

    Short interfering RNAs (siRNAs) are often used to deplete viral polycistronic transcripts, such as those encoded by human papillomavirus (HPV). There are conflicting data in the literature concerning how siRNAs targeting one HPV gene can affect levels of other genes in the polycistronic transcripts. We hypothesised that the conflict might be partly explained by the method of cDNA synthesis used prior to transcript quantification. We treated HPV16-positive cervical keratinocytes with siRNAs targeting the HPV16 E7 gene and used quantitative PCR to compare transcript levels of E7 with those of E6 and E2, viral genes located upstream and downstream of the target site respectively. We compared our findings from cDNA generated using oligo-dT primers alone with those from cDNA generated using a combination of random hexamer and oligo-dT primers. Our data show that when polycistronic transcripts are targeted by siRNAs, there is a period when untranslatable cleaved mRNA upstream of the siRNA binding site remains detectable by PCR, if cDNA is generated using random hexamer primers. Such false indications of mRNA abundance are avoided using oligo-dT primers. The period corresponds to the time taken for siRNA activity and degradation of the cleaved transcripts. Genes downstream of the siRNA binding site are detectable during this interval, regardless of how the cDNA is generated. These data emphasise the importance of the cDNA synthesis method used when measuring transcript abundance following siRNA depletion of polycistronic transcripts. They provide a partial explanation for erroneous reports suggesting that siRNAs targeting HPV E7 can have gene-specific effects.

  16. Hyperspectral microscope imaging methods to classify gram-positive and gram-negative foodborne pathogenic bacteria

    Science.gov (United States)

    An acousto-optic tunable filter-based hyperspectral microscope imaging method has potential for identification of foodborne pathogenic bacteria from microcolony rapidly with a single cell level. We have successfully developed the method to acquire quality hyperspectral microscopic images from variou...

  17. Classification of gram-positive and gram-negative foodborne pathogenic bacteria with hyperspectral microscope imaging

    Science.gov (United States)

    Optical method with hyperspectral microscope imaging (HMI) has potential for identification of foodborne pathogenic bacteria from microcolonies rapidly with a cell level. A HMI system that provides both spatial and spectral information could be an effective tool for analyzing spectral characteristic...

  18. Convenient synthesis of deuterated aluminium hydrides

    Energy Technology Data Exchange (ETDEWEB)

    Pawelke, Roland H.; Felderhoff, Michael; Weidenthaler, Claudia [Max-Planck-Institut fuer Kohlenforschung, Kaiser-Wilhelm-Platz 1, 45470 Muelheim an der Ruhr (Germany); Schueth, Ferdi [Max-Planck-Institut fuer Kohlenforschung, Kaiser-Wilhelm-Platz 1, 45470 Muelheim an der Ruhr (Germany)], E-mail: schueth@mpi-muelheim.mpg.de

    2008-09-15

    We describe the ball-milling synthesis of alkali metal deuterides from commercial lithium aluminium deuteride. This reaction principle was exemplified by the mechanochemical synthesis of NaAlD{sub 4} and KAlD{sub 4}. NaAlD{sub 4} was prepared on the multi-gram scale by this procedure and purified by standard wet-chemical separation. Pure NaAlD{sub 4} was obtained and used for the synthesis of Ca(AlD{sub 4}){sub 2}. The formation of all products was verified by X-ray diffraction.

  19. Gram-positive bacteria of marine origin: a numerical taxonomic study on Mediterranean isolates.

    Science.gov (United States)

    Ortigosa, M; Garay, E; Pujalte, M J

    1997-12-01

    A numerical taxonomic study was performed on 65 Gram-positive wild strains of heterotrophic, aerobic, marine bacteria, and 9 reference strains. The isolates were obtained from oysters and seawater sampled monthly over one year, by direct plating on Marine Agar. The strains were characterized by 96 morphological, biochemical, physiological and nutritional tests. Clustering yielded 13 phena at 0.62 similarity level (Sl coefficient). Only one of the seven phena containing wild isolates could be identified (Bacillus marinus). A pronounced salt requirement was found in most isolates.

  20. Amplifiable DNA from Gram-negative and Gram-positive bacteria by a low strength pulsed electric field method

    Science.gov (United States)

    Vitzthum, Frank; Geiger, Georg; Bisswanger, Hans; Elkine, Bentsian; Brunner, Herwig; Bernhagen, Jürgen

    2000-01-01

    An efficient electric field-based procedure for cell disruption and DNA isolation is described. Isoosmotic suspensions of Gram-negative and Gram-positive bacteria were treated with pulsed electric fields of Pulses had an exponential decay waveform with a time constant of 3.4 µs. DNA yield was linearly dependent on time or pulse number, with several thousand pulses needed. Electrochemical side-effects and electrophoresis were minimal. The lysates contained non-fragmented DNA which was readily amplifiable by PCR. As the method was not limited to samples of high specific resistance, it should be applicable to physiological fluids and be useful for genomic and DNA diagnostic applications. PMID:10734214

  1. Organo-Selenium Coatings Inhibit Gram-Negative and Gram-Positive Bacterial Attachment to Ophthalmic Scleral Buckle Material.

    Science.gov (United States)

    Tran, Phat; Arnett, Avery; Jarvis, Courtney; Mosley, Thomas; Tran, Khien; Hanes, Rob; Webster, Dan; Mitchell, Kelly; Dominguez, Leo; Hamood, Abdul; Reid, Ted W

    2017-09-01

    Biofilm formation is a problem for solid and sponge-type scleral buckles. This can lead to complications that require removal of the buckle, and result in vision loss due to related ocular morbidity, primarily infection, or recurrent retinal detachment. We investigate the ability of a covalent organo-selenium coating to inhibit biofilm formation on a scleral buckle. Sponge and solid Labtican brand scleral buckles were coated with organo-selenium coupled to a silyation reagent. Staphylococcus aureus biofilm formation was monitored by a standard colony-forming unit assay and the confocal laser scanning microscopy, while Pseudomonas aeruginosa biofilm formation was examined by scanning electron microscopy. Stability studies were done, by soaking in phosphate buffer saline (PBS) at room temperature for 2 months. Toxicity against human corneal epithelial cell was examined by growing the cells in the presence of organo-selenium-coated scleral buckles. The organo-selenium coating inhibited biofilm formation by gram-negative and gram-positive bacteria. The buckle coatings also were shown to be fully active after soaking in PBS for 2 months. The organo-selenium coatings had no effect on the viability of human corneal epithelial cells. Organo-selenium can be used to covalently coat a scleral buckle, which is stable and inhibits biofilm formation for gram-negative and gram-positive bacteria. The organo-selenium buckle coating was stable and nontoxic to cell culture. This technology provides a means to inhibit bacterial attachment to devices attached to the eye, without damage to ocular cells.

  2. Effects of Tillage Systems on Changes of Soil Nutrients, Yield and Land Equivalent Ratio in Roselle – Green Gram Intercropping

    Directory of Open Access Journals (Sweden)

    A Hodiani mehr

    2017-10-01

    Full Text Available Introduction Intercropping is one of the components of sustainable agriculture and as part of crop rotation in the design of sustainable system. One of the benefits of intercropping is greater use of available resources. The aims of this study were to evaluate different tillage systems and cropping patterns of Roselle and Green Gram on some soil nutrients and the use efficiency of environmental resources. Usually, intercropping used at Low fertility soil with low input conditions in the tropics region. Bahrani et al. (2007 reported that no tillage systems compared with conventional tillage with crop residue, were increased soil organic carbon content in maize production. Ramroudi et al. (2011 expressed conventional tillage reduced amount of nitrogen compared to no tillage system. Material and Methods The research was conducted at Zabol city. Split plot experiment performed based on a randomized complete block design with three replications. Main plot was three levels of tillage system (zero (without plowing, reduced (disk and conventional tillage (disc plow and sub plot was planting ratio with five levels (pure culture of Roselle, pure culture of Green gram, 50% roselle+50% green gram, 25% roselle+75% green gram, 75% roselle+25% green gram were considered. Preparing the ground in mid-June 2012, according to the type of plowing was performed. For comparison of means were used by Duncan's test at 5% probability. Results and Discussion The effects of tillage systems, planting ratios and interaction of tillage systems × planting ratio on soil organic carbon and nitrogen were very significant. The highest and lowest levels of organic carbon were obtained in zero tillage (1.14% and conventional tillage systems (0.63 %, respectively. The highest and lowest nitrogen of soil after harvest, of pure culture of Green gram (0.11 % and 75 % of Roselle + 25% Green gram intercropping (0.06 % were obtained respectively, Tillage system could not affected the

  3. Characterization of cycP gene expression in Achromobacter xylosoxidans NCIMB 11015 and high-level heterologous synthesis of cytochrome c' in Escherichia coli.

    Science.gov (United States)

    Harris, Roger L; Barbieri, Sonia; Paraskevopoulos, Kostas; Murphy, Loretta M; Eady, Robert R; Hasnain, S Samar; Sawers, R Gary

    2010-01-01

    The cycP gene encoding a periplasmic cytochrome c' from the denitrifying beta-proteobacterium Achromobacter xylosoxidans was characterized. The genes flanking cycP encode components of a mobile genetic element characteristic of the beta-proteobacteria, suggesting that cycP has inserted within a transposon or insertion element. The gene therefore does not form part of a denitrification operon or gene cluster. The level of expression of the cycP gene and the level of synthesis of its corresponding gene product were found to increase by maximally 3-fold anaerobically. Expression of cycP appears to occur mainly by non-specific read-through transcription from portions of the insertion element. Conditions were developed for high-level overproduction of cytochrome c' in Escherichia coli, which resulted in signal peptide cleavage concomitant with secretion of the protein into the periplasm. Using a single-step purification, 20-30 mg of pure protein were isolated from a 1-litre culture. Based on UV-visible spectrophotometry the dimeric protein was shown to have a full complement of haem and to be indistinguishable from the native protein purified from A. xylosoxidans. This system provides an excellent platform to facilitate biochemical and structural dissection of the mechanism underlying the novel specificity of NO binding to the proximal face of the haem.

  4. Synthesis and stable isotope dilution assay of ethanethiol and diethyl disulfide in wine using solid phase microextraction. Effect of aging on their levels in wine.

    Science.gov (United States)

    Belancic Majcenovic, Andrea; Schneider, Rémi; Lepoutre, Jean-Paul; Lempereur, Valérie; Baumes, Raymond

    2002-11-06

    Ethanethiol and diethyl disulfide (DEDS) most often occurred at levels above their olfactive threshold in wines with nauseous sulfur-linked smells. As ethanethiol is very oxidizable and chemically reactive, a stable isotopic dilution analysis of both ethanethiol and its disulfide in wines using solid phase microextraction and GC-MS was developed. The latter involved the determination of the proportion of DEDS formed by oxidation of the thiol during the analysis conditions, which was obtained by the use of two differently labeled disulfide standards. An original synthesis of labeled ethanethiol standards in conditions minimizing oxidation was developed, and the corresponding labeled diethyl disulfides were obtained from these thiols. This analytical method was used to follow the levels of these sulfur compounds during aging in a young red wine spiked with ethanethiol and added with enological tannins, with or without oxygen addition. The total levels of these two sulfur compounds were shown to decrease steadily after 60 days of aging, up to 83%. The effect of oxygen sped this decrease, but the effect of enological tannins was very slight. Residual ethanethiol was detected in its disulfide form from approximately 36% in the nonoxygenated wines to 69% in the oxygenated samples.

  5. Effect of precursor solutions stirring on deep level defects concentration and spatial distribution in low temperature aqueous chemical synthesis of zinc oxide nanorods

    Energy Technology Data Exchange (ETDEWEB)

    Alnoor, Hatim, E-mail: hatim.alnoor@liu.se; Chey, Chan Oeurn; Pozina, Galia; Willander, Magnus; Nur, Omer [Department of Science and Technology (ITN), Campus Norrköping, Linköping University, SE-601 74 Norrköping (Sweden); Liu, Xianjie; Khranovskyy, Volodymyr [Department of Physics, Chemistry and Biology (IFM), Linköping University, SE-583 81 Linköping (Sweden)

    2015-08-15

    Hexagonal c-axis oriented zinc oxide (ZnO) nanorods (NRs) with 120-300 nm diameters are synthesized via the low temperature aqueous chemical route at 80 °C on silver-coated glass substrates. The influence of varying the precursor solutions stirring durations on the concentration and spatial distributions of deep level defects in ZnO NRs is investigated. Room temperature micro-photoluminesnce (μ-PL) spectra were collected for all samples. Cathodoluminescence (CL) spectra of the as-synthesized NRs reveal a significant change in the intensity ratio of the near band edge emission (NBE) to the deep-level emission (DLE) peaks with increasing stirring durations. This is attributed to the variation in the concentration of the oxygen-deficiency with increasing stirring durations as suggested from the X-ray photoelectron spectroscopy analysis. Spatially resolved CL spectra taken along individual NRs revealed that stirring the precursor solutions for relatively short duration (1-3 h), which likely induced high super saturation under thermodynamic equilibrium during the synthesis process, is observed to favor the formation of point defects moving towards the tip of the NRs. In contrary, stirring for longer duration (5-15 h) will induce low super saturation favoring the formation of point defects located at the bottom of the NRs. These findings demonstrate that it is possible to control the concentration and spatial distribution of deep level defects in ZnO NRs by varying the stirring durations of the precursor solutions.

  6. Synthesis of novel acid electrolytes for phosphoric acid fuel cells

    Science.gov (United States)

    Adcock, James L.

    1988-11-01

    A 40 millimole per hour scale aerosol direct fluorination reactor was constructed. F-Methyl F-4-methoxybutanoate and F-4-methoxybutanoyl fluoride were synthesized by aerosol direct fluorination of methyl 4-methoxybutanoate. Basic hydrolysis of the perfluorinated derivatives produce sodium F-4 methoxybutanoate which was pyrolyzed to F-3-methoxy-1-propene. Purification and shipment of 33 grams of F-3-methoxy-1-propene followed. Syntheses by analogous methods allowed production and shipment of 5 grams of F-3-ethoxy 1-propene, 18 grams of F-3-(2-methoxy.ethoxy) 1-propene, and 37 grams of F-3,3-dimethyl 1-butene. Eighteen grams of F-2,2-dimethyl 1-chloropropane was produced directly and shipped. As suggested by other contractors, 5 grams of F-3-methoxy 1-iodopropane, and 5 grams of F-3-(2-methoxy.ethoxy) 1-iodopropane were produced by converting the respective precursor acid sodium salts produced for olefin synthesis to the silver salts and pyrolyzing them with iodine. Each of these compounds was prepared for the first time by the aerosol fluorination process during the course of the contract. These samples were provided to other Gas Research Institute (GRI) contractors for synthesis of perfluorinated sulfur (VI) and phosphorous (V) acids.

  7. High-level accumulation of oleyl oleate in plant seed oil by abundant supply of oleic acid substrates to efficient wax ester synthesis enzymes.

    Science.gov (United States)

    Yu, Dan; Hornung, Ellen; Iven, Tim; Feussner, Ivo

    2018-01-01

    Biotechnology enables the production of high-valued industrial feedstocks from plant seed oil. The plant-derived wax esters with long-chain monounsaturated acyl moieties, like oleyl oleate, have favorite properties for lubrication. For biosynthesis of wax esters using acyl-CoA substrates, expressions of a fatty acyl reductase (FAR) and a wax synthase (WS) in seeds are sufficient. For optimization of the enzymatic activity and subcellular localization of wax ester synthesis enzymes, two fusion proteins were created, which showed wax ester-forming activities in Saccharomyces cerevisiae . To promote the formation of oleyl oleate in seed oil, WSs from Acinetobactor baylyi ( Ab WSD1) and Marinobacter aquaeolei ( Ma WS2), as well as the two created fusion proteins were tested in Arabidopsis to evaluate their abilities and substrate preference for wax ester production. The tested seven enzyme combinations resulted in different yields and compositions of wax esters. Expression of a FAR of Marinobacter aquaeolei ( Ma FAR) with Ab WSD1 or Ma WS2 led to a high incorporation of C 18 substrates in wax esters. The Ma FAR/TM Mm AWAT2- Ab WSD1 combination resulted in the incorporation of more C 18:1 alcohol and C 18:0 acyl moieties into wax esters compared with Ma FAR/ Ab WSD1. The fusion protein of a WS from Simmondsia chinensis ( Sc WS) with MaFAR exhibited higher specificity toward C 20:1 substrates in preference to C 18:1 substrates. Expression of Ma FAR/ Ab WSD1 in the Arabidopsis fad2 fae1 double mutant resulted in the accumulation of oleyl oleate (18:1/18:1) in up to 62 mol% of total wax esters in seed oil, which was much higher than the 15 mol% reached by Ma FAR/ Ab WSD1 in Arabidopsis Col-0 background. In order to increase the level of oleyl oleate in seed oil of Camelina , lines expressing Ma FAR/ Sc WS were crossed with a transgenic high oleate line. The resulting plants accumulated up to >40 mg g seed -1 of wax esters, containing 27-34 mol% oleyl oleate. The

  8. Rosuvastatin lowers coenzyme Q10 levels, but not mitochondrial adenosine triphosphate synthesis, in children with familial hypercholesterolemia

    NARCIS (Netherlands)

    Avis, Hans J.; Hargreaves, Ian P.; Ruiter, Jos P. N.; Land, John M.; Wanders, Ronald J.; Wijburg, Frits A.

    2011-01-01

    To investigate whether statin therapy affects coenzyme Q10 (CoQ10) status in children with heterozygous familial hypercholesterolemia (FH). Samples were obtained at baseline (treatment naïve) and after dose titration with rosuvastatin, aiming for a low-density lipoprotein cholesterol level of 110

  9. Synthesis of glycogen from fructose in the presence of elevated levels of glycogen phosphorylase a in rat hepatocytes.

    Science.gov (United States)

    Ciudad, C J; Massagué, J; Salavert, A; Guinovart, J J

    1980-03-20

    Incubation of hepatocytes with glucose promoted the increase in the glycogen synthase (-glucose 6-phosphate/+glucose 6-phosphate) activity ratio, the decrease in the levels of phosphorylase a and a marked increase in the intracellular glycogen level. Incubation with fructose alone promoted the simultaneous activation of glycogen synthase and increase in the levels of phosphorylase a. Strikingly, glycogen deposition occurred in spite of the elevated levels of phosphorylase a. When glucose and fructose were added to the media the activation of glycogen synthase was always higher than when the hexoses were added separately. On the other hand the effects on glycogen phosphorylase were a function of the relative concentrations of both sugars. Inactivation of glycogen phosphorylase occurred when the fructose to glucose ratio was low while activation took place when the ratio was high. The simultaneous presence of glucose and fructose resulted, in all cases, in an enhancement in the deposition of glycogen. The effects described were not limited to fructose as D-glyceraldehyde, dihydroxyacetone, L-sorbose, D-tagatose and sorbitol, compounds metabolically related to fructose, provoked the same behaviour.

  10. Evaluation of Inhibitory and Lethal Effects of Aqueous, Ethanolic and Hydroalcoholic Extracts of Aerial Parts of Salvia chorassanica against Some Gram-negative and Gram-positive Bacteria in Vitro

    Directory of Open Access Journals (Sweden)

    Azam Mehraban

    2016-05-01

    Full Text Available Abstract Background and Objectives: Development of bacterial resistance to antibiotics has led to an increased tendency to development of new more effective and non-toxic antimicrobial compounds. In this study, the inhibitory and lethal effects of aqueous, ethanolic, and hydroalcoholic extracts of aerial parts of Salvia chorassanica were evaluated against Listeria monocytogenes, Bacillus cereus, Salmonella typhi, and Escherichia coli O:157. Methods: In this study, Kirby–Bauer disk diffusion method was used to evaluate antimicrobial activity. In this method, bacteria were cultivated as grass culture in Mueller Hinton Agar (MHA media. To determine the minimum inhibitory concentration and minimum bactericidal concentration, micro-dilution method with ELISA and addition of phenyl tetrazolium chloride reagent, were used. Data were analyzed using one-way ANOVA and Duncan’s test at the significance level of p<0.05. Results: The highest diameter of inhibition in agar diffusion method was related to hydroalcoholic extract of aerial parts of Salvia chorassanica against Gram-positive bacteria Bacillus cereus. The amount of calculated MIC of hydro-alcoholic extract for Gram-positive bacteria was 30mg/ml. This amount was the lowest among other measured MIC. Conclusion: Based on the results of this study, Gram-negative bacteria showed more resistance to different extracts of aerial parts of Salvia chorassanica as compared to Gram-positive bacteria, so that Salmonella typhi was found to be the most resistant bacterium among the tested bacteria.

  11. New Flurbiprofen Derivatives: Synthesis, Membrane Affinity and Evaluation of in Vitro Effect on β-Amyloid Levels

    Directory of Open Access Journals (Sweden)

    Stephanie Pacella

    2013-09-01

    Full Text Available Alzheimer’s disease (AD is characterized by irreversible and progressive loss of memory and cognition and profound neuronal loss. Current therapeutic strategies for the treatment of AD have been directed to a variety of targets with the aim of reversing or preventing the disease but, unfortunately, the available treatments often produce no significant clinical benefits. During the last decades compounds that inhibit or modulate γ-secretase, reducing β amyloid (Aβ levels, have been considered as potential therapeutics for AD. Among these the (R-enantiomer of flurbiprofen (FLU seems to be very promising, but it shows low brain penetration. In this study, in order to improve the properties of FLU against Alzheimer’s pathogenesis we synthesized some novel FLU lipophilic analogues. Lipophilicity of the new molecules has been characterized in terms of clogP, log KC18/W and log K IAM/W values. Permeability has been determined in both gastrointestinal PAMPA (PAMPA-GI at different pH values and in brain blood barrier PAMPA (PAMPA-BBB models. They were also tested for their ability to inhibit in vitro γ-secretase activity using rat CTXTNA2 astrocytes. Interestingly, the investigated molecules demonstrated to reduce Aβ 42 levels without affecting the amyloid precursor protein APP level in a clear concentrations-dependent manner.

  12. DMPD: Cellular reprogramming by gram-positive bacterial components: a review. [Dynamic Macrophage Pathway CSML Database

    Lifescience Database Archive (English)

    Full Text Available 16885502 Cellular reprogramming by gram-positive bacterial components: a review. Bu...(.csml) Show Cellular reprogramming by gram-positive bacterial components: a review. PubmedID 16885502 Title... Cellular reprogramming by gram-positive bacterial components: a review. Authors

  13. Use of magnetic beads for Gram staining of bacteria in aqueous suspension.

    Science.gov (United States)

    Yazdankhah, S P; Sørum, H; Larsen, H J; Gogstad, G

    2001-12-01

    A Gram staining technique was developed using monodisperse magnetic beads in concentrating bacteria in suspension for downstream application. The technique does not require heat fixation of organisms, electrical power, or a microscope. Gram-negative and Gram-positive bacteria were identified macroscopically based on the colour of the suspension. The bacteria concentrated on magnetic beads may also be identified microscopically.

  14. Is the gram stain useful in the microbiologic diagnosis of VAP? A meta-analysis.

    Science.gov (United States)

    O'Horo, John C; Thompson, Deb; Safdar, Nasia

    2012-08-01

    In a meta-analysis examining respiratory specimen Gram stain for diagnosis of ventilator-associated pneumonia, absence of bacteria on Gram stain had a high negative predictive value, but a positive Gram stain correlated poorly with organisms recovered in culture. Rapid and accurate diagnosis of ventilator-associated pneumonia (VAP) is a major challenge and no generally accepted gold standard exists for VAP diagnosis. We conducted a meta-analysis to examine the role of respiratory specimen Gram stain to diagnose VAP, and the correlation with final culture results. In 21 studies, pooled sensitivity of Gram stain for VAP was 0.79 (95% confidence interval [CI], .77-0.81; P Gram stain for a VAP prevalence of 20%-30% was 91%, suggesting that VAP is unlikely with a negative Gram stain but the positive predictive value of Gram stain was only 40%. Pooled kappa was 0.42 for gram-positive organisms and 0.34 for gram-negative organisms, suggesting fair concordance between organisms on Gram stain and recovery by culture. Therefore, a positive Gram stain should not be used to narrow anti-infective therapy until culture results become available.

  15. [Characteristic of clinical strains of gram-negative obligate anaerobes].

    Science.gov (United States)

    Kadzielska, Joanna; Kierzkowska, Marta; Sawicka-Grzelak, Anna; Rokosz, Alicja; Łuczak, Mirosław

    2007-01-01

    The aim of the study was to assess prevalence and antibiotic susceptibility profiles ofGram-negative strictly anaerobic bacteria isolated from clinical specimens taken from hospitalized patients in 2005-2006. Biochemical identification and antibiotic susceptibility were done in an automated system ATB Expression (bioMerieux sa). From 12262 specimens examined 867 strains of obligate anaerobes were isolated. Gram-negative strictly anaerobic bacteria were cultured in number of 138 strains (15,9%). All cultures were performed on Columbia agar and Schaedler agar media (bioMerieux sa) supplemented with 5% sheep blood and incubated at 37 degrees C for 48-120 h in 85% N2, 10% H2, 5% CO2. Most frequently isolated was Bacteroides spp. (41,3%). For this group beta-lactamase activity was evaluated by using nitrocefin disc test (Cefinase BBL, Becton Dickinson and Co., Cockeysville, MD, USA). Production of ESBLs was detected with the use of two disc diffusion methods: the double-disc synergy test (DDST) according to Jarlier et al. and the diagnostic disc (DD) test according to Appleton. ESBLs were produced by 5,3% strains of Bacteroides spp. For all Bacteroides spp. strains MIC values were determined by gradient diffusion method Etest (AB BIODISK, Sweden). ESBLs and MIC were performed on Wilkins-Chalgren solid medium supplemented with 5% sheep blood (Difco Lab., USA) and all plates were incubated at 35 degrees C for 48 hours in 85% N2, 10% H2, 5% CO2. Most Gram-negative obligate anaerobes isolated from clinical specimens are still susceptible to imipenem (100%), metronidazole (99,3%) and beta-lactam antibiotics with beta-lactamase inhibitors: piperacillin/tazobactam (99,3%), ticarcillin/clavulanate (99.3%), amoxicillin/clavulanate (97.8%).

  16. [Diagnostic and therapeutic management of Gram-negative infections].

    Science.gov (United States)

    Bassetti, Matteo; Repetto, Ernestina

    2008-04-01

    Among Gram negative bacteria, Pseudomonas aeruginosa, the extended spectrum beta-lactamases (ESBL)-producing strains, Acinetobacter spp, in particular the multiresistant Acinetobacter baumannii, and Stenotrophomonas maltophilia are the most implicated micrororganisms in the ever more increasing problem of bacterial resistance. Possible solutions have to be searched, on one hand, in the use of new drugs but, on the other hand, in the re-evaluation of those already available drugs, possibly considering a new role for old drugs such as colistine and fosfomycin. Concerning ESBL-producing strains, the most recent data provided by EARSS report, in Italy, an incidence rate of 10-25 percent. The insurgence of an infection sustained by an ESBL+ve strain is strictly related to some well known risk factors, like the hospital stay itself, the disease severity, the length of stay in ICU, intubation and mechanical ventilation, catheterization, urinary or artery, and the past exposure to antibiotics. The raise in ESBL producing strains is closely related to the increasing use of cephalosporins. In the setting of a Gram negative infection, the combination therapy guarantees a higher coverage by reducing insurgence of possible resistance mechanisms, possibly resulting synergistic, and allowing a de-escalation therapy, although to this latter other problems, such as tolerability, costs and compliance, can be related. Another basic aspect to take into account of, in order to achieve the maximal efficacy of the antibiotic treatment, is the right dosage. In the idea to look for the best approach for the antibiotic treatment of a severe infection in a hospital setting, when a Gram negative aetiology is implicated, it can be possibly presumed that the right way consists in avoiding inappropriate antibiotic therapies, making therapeutic choices based on guidelines resulted from local epidemiological data, initiating the therapy promptly, avoiding excessive use of antibiotics, possibly

  17. In vitro Efficacy of Meropenem, Colistin and Tigecycline Against the Extended Spectrum Beta-Lactamase Producing Gram Negative Bacilli

    International Nuclear Information System (INIS)

    Gill, M. M.; Usman, J.; Hassan, A.; Kaleem, F.; Anjum, R.

    2015-01-01

    Objective:To compare the in vitroefficacy of meropenem, colistin and tigecycline against extended spectrum Betalactamase producing Gram negative bacilli by minimal inhibitory concentration. Study Design:Cross-sectional descriptive study. Place and Duration of Study: Department of Microbiology, Army Medical College, National University of Sciences and Technology, Rawalpindi, from June to December 2010. Methodology: Routine clinical specimens were subjected to standard microbiological procedures and the isolates were identified to species level. Extended spectrum beta-lactamase producing Gram negative bacilli were detected by Jarlier disc synergy method and confirmed by ceftazidime and ceftazidime-clavulanate Etest. Minimum Inhibitory Concentration (MIC90) of meropenem, colistin and tigecycline was determined by Etest (AB BIOMERIUX) and the results were interpreted according to the manufacturer's instructions and Clinical and Laboratory Standards Institute guidelines and Food and Drug Authority recommendations. Results were analyzed by using Statistical Package for the Social Sciences version 20. Results: A total of 52 non-duplicate extended spectrum Beta-lactamase-producing Gram negative bacilli were included in the study. The MIC90 of tigecycline (0.75 micro g/ml) was lowest as compared to the meropenem (2 micro g/ml) and colistin (3 micro g/ml). Conclusion: Tigecycline is superior in efficacy against the extended spectrum Beta-lactamase producing Gram negative bacilli as compared to colistin and meropenem. (author)

  18. Daptomycin treatment in Gram-positive vascular graft infections

    Directory of Open Access Journals (Sweden)

    Francisco Arnaiz de las Revillas

    2018-03-01

    Full Text Available Background: Daptomycin is a bactericidal antibiotic approved for the treatment of skin and soft tissue infections and right-side endocarditis. However, there is a lack of published data outlining its usefulness in vascular graft infections (VGI. The aim of this study was to describe the clinical experience of daptomycin use in the treatment of VGI caused by Gram-positive bacteria. Methods: This was a retrospective cohort study of patients diagnosed with VGI receiving daptomycin at a tertiary care hospital during the period January 2010 to December 2012. Results: Of a total 1066 consecutive patients who had undergone vascular grafts (VG, 25 were diagnosed with VGI. Fifteen of these patients (11 prosthetic VG, three autologous VG, one both types received daptomycin (median dose 6.7 mg/kg/day, range 4.1–7.1 mg/kg/day; median age 69 years, range 45–83 years; 80% male. The infected bypass was removed in 13 cases. The most common reason for selecting daptomycin was kidney failure (53%. The Gram-positive organisms isolated were coagulase-negative Staphylococcus (n = 10, Staphylococcus aureus (n = 3 (two methicillin-resistant S. aureus, Enterococcus faecium (n = 2, and Enterococcus faecalis (n = 1. The mean follow-up was 69 months (interquartile range 48–72 months. Ten patients (66.7% achieved complete healing of the VGI. A recurrence of the infection was observed in 100% of patients in whom the bypass was not removed. Among patients who did not achieve complete healing, one needed a supracondylar amputation and one died as a consequence of infection. Five patients received treatment with rifampicin in addition to daptomycin and they were all cured. Conclusions: The use of daptomycin and surgery for Gram-positive VGI was effective and well tolerated, and this may be a good alternative for the treatment of VGI in patients with peripheral arterial disease in whom renal insufficiency is common. Keywords: Daptomycin, Gram-positive, Vascular

  19. Understanding the sub-cellular dynamics of silicon transportation and synthesis in diatoms using population-level data and computational optimization.

    Directory of Open Access Journals (Sweden)

    Narjes Javaheri

    2014-06-01

    Full Text Available Controlled synthesis of silicon is a major challenge in nanotechnology and material science. Diatoms, the unicellular algae, are an inspiring example of silica biosynthesis, producing complex and delicate nano-structures. This happens in several cell compartments, including cytoplasm and silica deposition vesicle (SDV. Considering the low concentration of silicic acid in oceans, cells have developed silicon transporter proteins (SIT. Moreover, cells change the level of active SITs during one cell cycle, likely as a response to the level of external nutrients and internal deposition rates. Despite this topic being of fundamental interest, the intracellular dynamics of nutrients and cell regulation strategies remain poorly understood. One reason is the difficulties in measurements and manipulation of these mechanisms at such small scales, and even when possible, data often contain large errors. Therefore, using computational techniques seems inevitable. We have constructed a mathematical model for silicon dynamics in the diatom Thalassiosira pseudonana in four compartments: external environment, cytoplasm, SDV and deposited silica. The model builds on mass conservation and Michaelis-Menten kinetics as mass transport equations. In order to find the free parameters of the model from sparse, noisy experimental data, an optimization technique (global and local search, together with enzyme related penalty terms, has been applied. We have connected population-level data to individual-cell-level quantities including the effect of early division of non-synchronized cells. Our model is robust, proven by sensitivity and perturbation analysis, and predicts dynamics of intracellular nutrients and enzymes in different compartments. The model produces different uptake regimes, previously recognized as surge, externally-controlled and internally-controlled uptakes. Finally, we imposed a flux of SITs to the model and compared it with previous classical kinetics

  20. Metabolic versatility of Gram-positive microbial isolates from contaminated river sediments

    International Nuclear Information System (INIS)

    Narancic, Tanja; Djokic, Lidija; Kenny, Shane T.; O’Connor, Kevin E.; Radulovic, Vanja; Nikodinovic-Runic, Jasmina; Vasiljevic, Branka

    2012-01-01

    Highlights: ► Thirty-four isolated Gram-positive bacteria could degrade wide range of aromatic pollutants. ► Nine isolates could grow in the presence of extremely high levels of heavy metals. ► Twelve isolates accumulated polyphosphate, 3 polyhydroxybutyrate, 4 exopolysaccharides. ► The incidence of multiple antibiotic resistance markers among isolates was low. - Abstract: Gram-positive bacteria from river sediments affected by the proximity of a petrochemical industrial site were isolated and characterized with respect to their ability to degrade a wide range of aromatic compounds. In this study we identified metabolically diverse Gram-positive bacteria capable of growth on wide range aromatic compounds in the presence of heavy metals and with the ability to accumulate biopolymers. Thirty-four isolates that were able to use 9 or more common aromatic pollutants, such as benzene, biphenyl, naphthalene etc. as a sole source of carbon and energy included members of Bacillus, Arthrobacter, Rhodococcus, Gordonia, Streptomyces, and Staphylococcus genus. Rhodococcus sp. TN105, Gordonia sp. TN103 and Arthrobacter sp. TN221 were identified as novel strains. Nine isolates were able to grow in the presence of one or more metals (mercury, cadmium, nickel) at high concentration (100 mM). Seven isolates could degrade 15 different aromatic compounds and could grow in the presence of one or more heavy metals. Two of these isolates were resistant to multiple antibiotics including erythromycin and nalidixic acid. One third of isolates could accumulate at least one biopolymer. Twelve isolates (mainly Bacillus sp. and Arthrobacter sp.) accumulated polyphosphate, 3 Bacillus sp. accumulated polyhydroxybutyrate, while 4 isolates could accumulate exopolysaccharides.

  1. Inhaled Antibiotics for Gram-Negative Respiratory Infections

    Science.gov (United States)

    Fraidenburg, Dustin R.; Scardina, Tonya

    2016-01-01

    SUMMARY Gram-negative organisms comprise a large portion of the pathogens responsible for lower respiratory tract infections, especially those that are nosocomially acquired, and the rate of antibiotic resistance among these organisms continues to rise. Systemically administered antibiotics used to treat these infections often have poor penetration into the lung parenchyma and narrow therapeutic windows between efficacy and toxicity. The use of inhaled antibiotics allows for maximization of target site concentrations and optimization of pharmacokinetic/pharmacodynamic indices while minimizing systemic exposure and toxicity. This review is a comprehensive discussion of formulation and drug delivery aspects, in vitro and microbiological considerations, pharmacokinetics, and clinical outcomes with inhaled antibiotics as they apply to disease states other than cystic fibrosis. In reviewing the literature surrounding the use of inhaled antibiotics, we also highlight the complexities related to this route of administration and the shortcomings in the available evidence. The lack of novel anti-Gram-negative antibiotics in the developmental pipeline will encourage the innovative use of our existing agents, and the inhaled route is one that deserves to be further studied and adopted in the clinical arena. PMID:27226088

  2. Daptomycin: a novel lipopeptide antibiotic against Gram-positive pathogens

    Directory of Open Access Journals (Sweden)

    Andres Beiras-Fernandez

    2010-08-01

    Full Text Available Andres Beiras-Fernandez1,*, Ferdinand Vogt1,*, Ralf Sodian1, Florian Weis21Department of Cardiac Surgery, University Hospital Großhadern, Ludwig-Maximilian-University, Munich, Germany; 2Department of Anesthesiology, University Hospital Großhadern, Ludwig-Maximilian-University, Munich, Germany *Andres Beiras-Fernandez and Ferdinand Vogt contributed equally to this paperAbstract: The aim of this review is to summarize the historical background of drug resistance of Gram-positive pathogens as well as to describe in detail the novel lipopeptide antibiotic daptomycin. Pharmacological and pharmacokinetic aspects are reviewed and the current clinical use of daptomycin is presented. Daptomycin seems to be a reliable drug in the treatment of complicated skin and skin structure infections, infective right-sided endocarditis, and bacteremia caused by Gram-positive agents. Its unique mechanism of action and its low resistance profile, together with its rapid bactericidal action make it a favorable alternative to vancomycin in multi-drug resistant cocci. The role of daptomycin in the treatment of prosthetic material infections, osteomyelitis, and urogenital infections needs to be evaluated in randomized clinical trials.Keywords: daptomycin, multi-drug resistance, methicillin-resistant Staphylococcus aureus (MRSA, pneumonia, urinary tract infection, left-sided endocarditis

  3. VIP as a potential therapeutic agent in gram negative sepsis.

    Science.gov (United States)

    Ibrahim, Hiba; Barrow, Paul; Foster, Neil

    2012-12-01

    Gram negative sepsis remains a high cause of mortality and places a great burden on public health finance in both the developed and developing world. Treatment of sepsis, using antibiotics, is often ineffective since pathology associated with the disease occurs due to dysregulation of the immune system (failure to return to steady state conditions) which continues after the bacteria, which induced the immune response, have been cleared. Immune modulation is therefore a rational approach to the treatment of sepsis but to date no drug has been developed which is highly effective, cheap and completely safe to use. One potential therapeutic agent is VIP, which is a natural peptide and is highly homologous in all vertebrates. In this review we will discuss the effect of VIP on components of the immune system, relevant to gram negative sepsis, and present data from animal models. Furthermore we will hypothesise on how these studies could be improved in future and speculate on the possible different ways in which VIP could be used in clinical medicine.

  4. Black-pigmented gram-negative anaerobes in endodontic infections.

    Science.gov (United States)

    Haapasalo, M

    1993-03-01

    Necrotic dental root canal infections are polymicrobial infections dominated by anaerobic bacteria. The number of different species in one canal is usually low, approx. 4-7 species. The species isolated most frequently belong to the genera Prevotella, Porphyromonas, Fusobacterium, Peptostreptococcus, Eubacterium and Streptococcus. The frequency of isolation of black-pigmented Gram-negative anaerobes in endodontic infections varies from 25% to > 50%. Pr. intermedia is the most commonly found pigmented species, followed by Pr. denticola and two Porphyromonas species, P. gingivalis and P. endodontalis. Several studies have shown that P. gingivalis and P. endodontalis are closely related to the presence of acute symptoms in endodontic infections, whereas other black-pigmented Gram-negative anaerobes are not. However, several other species may also be involved in acute infections. Moreover, Porphyromonas species have occasionally been isolated from cases with no symptoms. Although Porphyromonas spp. are clearly related to symptoms at the beginning of therapy, they are not important for the prognosis of the treatment.

  5. Effect of particle- and specimen-level transport on product state in compacted-powder combustion synthesis and thermal debinding of polymers from molded powders

    Science.gov (United States)

    Oliveira, Amir Antonio Martins

    The existence of large gradients within particles and fast temporal variations in the temperature and species concentration prevents the use of asymptotic approximations for the closure of the volume-averaged, specimen-level formulations. In this case a solution of the particle-level transport problem is needed to complement the specimen-level volume-averaged equations. Here, the use of combined specimen-level and particle-level models for transport in reactive porous media is demonstrated with two examples. For the gasless compacted-powder combustion synthesis, a three-scale model is developed. The specimen-level model is based on the volume-averaged equations for species and temperature. Local thermal equilibrium is assumed and the macroscopic mass diffusion and convection fluxes are neglected. The particle-level model accounts for the interparticle diffusion (i.e., the liquid migration from liquid-rich to liquid-lean regions) and the intraparticle diffusion (i.e., the species mass diffusion within the product layer formed at the surface of the high melting temperature component). It is found that the interparticle diffusion controls the extent of conversion to the final product, the maximum temperature, and to a smaller degree the propagation velocity. The intraparticle diffusion controls the propagation velocity and to a smaller degree the maximum temperature. The initial stages of thermal degradation of EVA from molded specimens is modeled using volume-averaged equations for the species and empirical models for the kinetics of the thermal degradation, the vapor-liquid equilibrium, and the diffusion coefficient of acetic acid in the molten polymer. It is assumed that a bubble forms when the partial pressure of acetic acid exceeds the external ambient pressure. It is found that the removal of acetic acid is characterized by two regimes, a pre-charge dominated regime and a generation dominated regime. For the development of an optimum debinding schedule, the

  6. Integrated biofuels process synthesis

    DEFF Research Database (Denmark)

    Torres-Ortega, Carlo Edgar; Rong, Ben-Guang

    2017-01-01

    Second and third generation bioethanol and biodiesel are more environmentally friendly fuels than gasoline and petrodiesel, andmore sustainable than first generation biofuels. However, their production processes are more complex and more expensive. In this chapter, we describe a two-stage synthesis......% used for bioethanol process), and steam and electricity from combustion (54%used as electricity) in the bioethanol and biodiesel processes. In the second stage, we saved about 5% in equipment costs and 12% in utility costs for bioethanol separation. This dual synthesis methodology, consisting of a top......-level screening task followed by a down-level intensification task, proved to be an efficient methodology for integrated biofuel process synthesis. The case study illustrates and provides important insights into the optimal synthesis and intensification of biofuel production processes with the proposed synthesis...

  7. A review and synthesis of international proposals for the disposal of high-level radioactive wastes into crystalline rock formations

    International Nuclear Information System (INIS)

    1981-05-01

    Examination of the broad range of international concepts for the disposal of high-level radioactive wastes into crystalline rock formations has indicated that systems based upon solid waste units provide the greatest degree of engineering control and security. Three particular disposal concepts are considered worthy of detailed evaluation. In order of priority these are:-tunnel networks with 'in-floor' waste emplacement; matrix of vertical emplacement holes drilled from the surface; tunnel networks with 'in-room' waste emplacement. A review of the international literature has shown that at least ten countries have embarked upon study programmes, but only five have developed detailed conceptual design proposals. These are:- Canada, France, Sweden, the United Kingdom, and the United States. Differing economic, environmental, historical and political circumstances have influenced the pattern of international studies and, to the uninitiated, these factors may obscure some of the relevant technical considerations. Nevertheless, a broad technical concensus is apparent in that all countries currently favour tunnel networks with 'in-floor' waste emplacement. The subject is discussed in detail. (author)

  8. Effect of the level of dietary protein on the utilization of alpha-ketoisocaproate for protein synthesis

    Energy Technology Data Exchange (ETDEWEB)

    Kang, C.W.; Tungsanga, K.; Walser, M.

    1986-04-01

    The efficiency of alpha-ketoisocaproate (KIC) as a dietary substitute for leucine in rats on varying protein intake was estimated by an isotopic method, previously shown to yield the same results as comparative growth experiments. /sup 14/C-KIC and /sup 3/H-leucine are injected orally. Six hours later the ratio, R, of /sup 14/C//sup 3/H in isolated proteins, divided by the same ratio in the injectate is measured. This ratio has been shown to be approximately equal to nutritional efficiency of KIC relative to leucine. As dietary protein increased from 6.3% to 48.3%, whole body protein R decreased from 0.515 +/- 0.045 to 0.299 +/- 0.016. Variations with protein intake were noted in R of protein isolated from individual organs. The magnitude of R in these organs varied two-fold, in the following sequence: brain greater than heart greater than or equal to skeletal muscle greater than or equal to salivary gland greater than or equal to kidney greater than liver. Whole body protein R could be confidently predicted (r2 = 0.992) from R in the protein of kidney and muscle. Thus, the nutritional efficiency of KIC as a dietary substitute for leucine in individual organs as well as in the whole animal is strongly dependent on the level of protein intake.

  9. Effect of the level of dietary protein on the utilization of alpha-ketoisocaproate for protein synthesis

    International Nuclear Information System (INIS)

    Kang, C.W.; Tungsanga, K.; Walser, M.

    1986-01-01

    The efficiency of alpha-ketoisocaproate (KIC) as a dietary substitute for leucine in rats on varying protein intake was estimated by an isotopic method, previously shown to yield the same results as comparative growth experiments. 14 C-KIC and 3 H-leucine are injected orally. Six hours later the ratio, R, of 14 C/ 3 H in isolated proteins, divided by the same ratio in the injectate is measured. This ratio has been shown to be approximately equal to nutritional efficiency of KIC relative to leucine. As dietary protein increased from 6.3% to 48.3%, whole body protein R decreased from 0.515 +/- 0.045 to 0.299 +/- 0.016. Variations with protein intake were noted in R of protein isolated from individual organs. The magnitude of R in these organs varied two-fold, in the following sequence: brain greater than heart greater than or equal to skeletal muscle greater than or equal to salivary gland greater than or equal to kidney greater than liver. Whole body protein R could be confidently predicted (r2 = 0.992) from R in the protein of kidney and muscle. Thus, the nutritional efficiency of KIC as a dietary substitute for leucine in individual organs as well as in the whole animal is strongly dependent on the level of protein intake

  10. Peptidoglycan Recycling in Gram-Positive Bacteria Is Crucial for Survival in Stationary Phase

    Science.gov (United States)

    Borisova, Marina; Gaupp, Rosmarie; Duckworth, Amanda; Schneider, Alexander; Dalügge, Désirée; Mühleck, Maraike; Deubel, Denise; Unsleber, Sandra; Yu, Wenqi; Muth, Günther; Bischoff, Markus; Götz, Friedrich

    2016-01-01

    ABSTRACT Peptidoglycan recycling is a metabolic process by which Gram-negative bacteria reutilize up to half of their cell wall within one generation during vegetative growth. Whether peptidoglycan recycling also occurs in Gram-positive bacteria has so far remained unclear. We show here that three Gram-positive model organisms, Staphylococcus aureus, Bacillus subtilis, and Streptomyces coelicolor, all recycle the sugar N-acetylmuramic acid (MurNAc) of their peptidoglycan during growth in rich medium. They possess MurNAc-6-phosphate (MurNAc-6P) etherase (MurQ in E. coli) enzymes, which are responsible for the intracellular conversion of MurNAc-6P to N-acetylglucosamine-6-phosphate and d-lactate. By applying mass spectrometry, we observed accumulation of MurNAc-6P in MurNAc-6P etherase deletion mutants but not in either the isogenic parental strains or complemented strains, suggesting that MurQ orthologs are required for the recycling of cell wall-derived MurNAc in these bacteria. Quantification of MurNAc-6P in ΔmurQ cells of S. aureus and B. subtilis revealed small amounts during exponential growth phase (0.19 nmol and 0.03 nmol, respectively, per ml of cells at an optical density at 600 nm [OD600] of 1) but large amounts during transition (0.56 nmol and 0.52 nmol) and stationary (0.53 nmol and 1.36 nmol) phases. The addition of MurNAc to ΔmurQ cultures greatly increased the levels of intracellular MurNAc-6P in all growth phases. The ΔmurQ mutants of S. aureus and B. subtilis showed no growth deficiency in rich medium compared to the growth of the respective parental strains, but intriguingly, they had a severe survival disadvantage in late stationary phase. Thus, although peptidoglycan recycling is apparently not essential for the growth of Gram-positive bacteria, it provides a benefit for long-term survival. PMID:27729505

  11. Antimicrobial effects of zero-valent iron nanoparticles on gram-positive Bacillus strains and gram-negative Escherichia coli strains

    Directory of Open Access Journals (Sweden)

    Yi-Huang Hsueh

    2017-11-01

    Full Text Available Abstract Background Zero-valent iron nanoparticles (ZVI NPs have been used extensively for the remediation of contaminated soil and groundwater. Owing to their large active surface area, they serve as strong and effective reductants. However, the ecotoxicity and bioavailability of ZVI NPs in diverse ecological media have not been evaluated in detail and most studies have focused on non-nano ZVI or Fe0. In addition, the antimicrobial properties of ZVI NPs have rarely been investigated, and the underlying mechanism of their toxicity remains unknown. Results In the present study, we demonstrate that ZVI NPs exhibited significant toxicity at 1000 ppm against two distinct gram-positive bacterial strains (Bacillus subtilis 3610 and Bacillus thuringiensis 407 but not against two gram-negative strains (Escherichia coli K12 and ATCC11634. Specifically, ZVI NPs caused at least a 4-log and 1-log reductions in cell numbers, respectively, in the two Bacillus strains, whereas no change was detected in the two E. coli strains. X-ray photoelectron spectroscopy, X-ray absorption near-edge, and extended X-ray absorption fine structure spectra confirmed that Bacillus cells exposed to ZVI NPs contained mostly Fe2O3 with some detectable FeS. This finding indicated that Fe0 nanoparticles penetrated the bacterial cells, where they were subsequently oxidized to Fe2O3 and FeS. RedoxSensor analysis and propidium iodide (PI staining showed decreased reductase activity and increased PI in both Bacillus strains treated with a high (1000 ppm concentration of ZVI NPs. Conclusion Taken together, these data show that the toxicity of ZVI NPs was derived from their oxidative properties, which may increase the levels of reactive oxygen species and lead to cell death.

  12. Effect of precursor solutions stirring on deep level defects concentration and spatial distribution in low temperature aqueous chemical synthesis of zinc oxide nanorods

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    Hatim Alnoor

    2015-08-01

    Full Text Available Hexagonal c-axis oriented zinc oxide (ZnO nanorods (NRs with 120-300 nm diameters are synthesized via the low temperature aqueous chemical route at 80 °C on silver-coated glass substrates. The influence of varying the precursor solutions stirring durations on the concentration and spatial distributions of deep level defects in ZnO NRs is investigated. Room temperature micro-photoluminesnce (μ-PL spectra were collected for all samples. Cathodoluminescence (CL spectra of the as-synthesized NRs reveal a significant change in the intensity ratio of the near band edge emission (NBE to the deep-level emission (DLE peaks with increasing stirring durations. This is attributed to the variation in the concentration of the oxygen-deficiency with increasing stirring durations as suggested from the X-ray photoelectron spectroscopy analysis. Spatially resolved CL spectra taken along individual NRs revealed that stirring the precursor solutions for relatively short duration (1-3 h, which likely induced high super saturation under thermodynamic equilibrium during the synthesis process, is observed to favor the formation of point defects moving towards the tip of the NRs. In contrary, stirring for longer duration (5-15 h will induce low super saturation favoring the formation of point defects located at the bottom of the NRs. These findings demonstrate that it is possible to control the concentration and spatial distribution of deep level defects in ZnO NRs by varying the stirring durations of the precursor solutions.

  13. Retrospective Analysis of Blood Stream Infections and Antibiotic Susceptibility Pattern of Gram Negative Bacteria in a Tertiary Care Cancer Hospital

    Directory of Open Access Journals (Sweden)

    Radha Rani D

    2017-12-01

    Full Text Available Background: Bacterial bloodstream infections are important causes of morbidity and mortality globally. The aim of the present study was to determine the bacterial profile of bloodstream infections and their antibiotic susceptibility pattern among the clinically diagnosed cases of sepsis in cancer patients. Methods: In the present study, etiological and antimicrobial susceptibility profile of blood cultures over a period of 1 year at a tertiary cancer care hospital was done. Blood culture positive isolates were identified using standard microbiological methods and by Fully automated BD Phoenix 100. The antibiotic susceptibility pattern of the organisms was performed by Kirby-Bauer disc diffusion method and MIC (Minimum inhibitory concentration was done by Fully automated BD Phoenix 100. Results: There were 1178 blood culture samples, of which 327 (27.7% were identified to be culture positive. Out of 327 positive cultures, 299 (91.4% showed bacterial growth, Gram negative were 161 (53.8% and Gram positive were 138 (46.1%. Candida species were isolated from 13 (3.97% of positive samples and 15 samples showed contamination. The most common Gram-negative isolate was. Escherichia coli (37.80% and Gram-positive isolate was coagulasenegative staphylococci (52.80%. Escherichia coli showed highest sensitivity to amikacin (83.60% and sensitivity to piperacillin+ tazobactum and cefaperazone+sulbactam was 54.09% and 52.45% respectively. High degree of resistance was found to cephalosporins and levofloxacin. Conclusion: The results indicate high level of antimicrobial resistance among Gram negative bacilli in septicemic patients. The results warrant continuous monitoring of antimicrobial pattern so as to build geographical epidemiological data.

  14. In vitro ciprofloxacin resistance patterns of gram positive bacteria isolated from clinical specimens in a teaching hospital in Saudi Arabia

    International Nuclear Information System (INIS)

    Akhtar, N.; Alzahrani, A.; Obeid, O.El-Treify; Dassal, D.

    2009-01-01

    Over the last few decades the ever-increasing level of bacterial resistance to antimicrobials has been a cause of worldwide concern. Fluoroquinolones, particularly ciprofloxacin has been used indiscriminately for both gram-positive and gram-negative bacterial infections. The increased use of ciprofloxacin has led to a progressive loss of bacterial susceptibility to this antibiotic. Therefore it is necessary to have update knowledge of resistance pattern of bacteria to this antibiotic so that alternate appropriate antibiotics can be used for ciprofloxacin-resistant bacterial infections. Objective: To evaluate the trends of ciprofloxacin resistance pattern in commonly isolated gram positive bacteria over time in a Saudi Arabian teaching hospital. Methods: A retrospective analysis was carried out for ciprofloxacin susceptibility patterns of 5534 isolates of gram-positive bacteria isolated from clinical specimens submitted to microbiology laboratories at King Fahd Hospital of the University (KFHU), Al-Khobar, Saudi Arabia during the period from January 2002 to August 2005. Results: Increase in ciprofloxacin resistance rates with some fluctuations, among these isolates, were observed. For Staphylococcus aureus, it varied from 4.62, 1.83, 7.01 and 3.98%, methicillin resistant Staphylococcus aureus (MRSA) 97.92, 97.75, 87.01 and 88.26%, Streptococcus pyogenes 5.35, 4.47, 14.44 and 3.53% during the years 2002, 2003, 2004 and 2005 respectively. Cirprofloxacin resistance during the years 2002, 2004 and 2005 for other isolates was as follows: Streptococcus pneumoniae, 30.23, 23.02 and 26.47%; enterococcus group D, 43.05, 20.68 and 57.03% and non-enterococcus group D, 62.96, 76.92 and 87.50% respectively. Conclusion: Ciprofloxacin resistance in gram positive bacterial clinical isolates particularly Staphylococcus aureus, methicillin resistant Staphylococcus aureus (MRSA) enterococcus group D, and non-enterococcus group D, has greatly increased and ciprofloxacin no more remains

  15. A pathway closely related to the (D)-tagatose pathway of gram-negative enterobacteria identified in the gram-positive bacterium Bacillus licheniformis.

    Science.gov (United States)

    Van der Heiden, Edwige; Delmarcelle, Michaël; Lebrun, Sarah; Freichels, Régine; Brans, Alain; Vastenavond, Christian M; Galleni, Moreno; Joris, Bernard

    2013-06-01

    We report the first identification of a gene cluster involved in d-tagatose catabolism in Bacillus licheniformis. The pathway is closely related to the d-tagatose pathway of the Gram-negative bacterium Klebsiella oxytoca, in contrast to the d-tagatose 6-phosphate pathway described in the Gram-positive bacterium Staphylococcus aureus.

  16. A Pathway Closely Related to the d-Tagatose Pathway of Gram-Negative Enterobacteria Identified in the Gram-Positive Bacterium Bacillus licheniformis

    Science.gov (United States)

    Van der Heiden, Edwige; Lebrun, Sarah; Freichels, Régine; Brans, Alain; Vastenavond, Christian M.; Galleni, Moreno; Joris, Bernard

    2013-01-01

    We report the first identification of a gene cluster involved in d-tagatose catabolism in Bacillus licheniformis. The pathway is closely related to the d-tagatose pathway of the Gram-negative bacterium Klebsiella oxytoca, in contrast to the d-tagatose 6-phosphate pathway described in the Gram-positive bacterium Staphylococcus aureus. PMID:23524682

  17. A Pathway Closely Related to the d-Tagatose Pathway of Gram-Negative Enterobacteria Identified in the Gram-Positive Bacterium Bacillus licheniformis

    OpenAIRE

    Van der Heiden, Edwige; Delmarcelle, Michaël; Lebrun, Sarah; Freichels, Régine; Brans, Alain; Vastenavond, Christian M.; Galleni, Moreno; Joris, Bernard

    2013-01-01

    We report the first identification of a gene cluster involved in d-tagatose catabolism in Bacillus licheniformis. The pathway is closely related to the d-tagatose pathway of the Gram-negative bacterium Klebsiella oxytoca, in contrast to the d-tagatose 6-phosphate pathway described in the Gram-positive bacterium Staphylococcus aureus.

  18. Comparative activity of tigecycline and tetracycline on Gram-negative and Gram-positive bacteria revealed by a multicentre study in four North European countries

    DEFF Research Database (Denmark)

    Nilsson, Lennart E; Frimodt-Møller, Niels; Vaara, Martti

    2011-01-01

    This study involves a multicentre surveillance of tigecycline and tetracycline activity against Gram-negative and Gram-positive bacteria from primary care centres (PCCs), general hospital wards (GHWs) and intensive care units (ICUs) in Denmark (n = 9), Finland (n = 10), Norway (n = 7) and Sweden (n...

  19. Dose-Dependent Antimicrobial Activity of Silver Nanoparticles on Polycaprolactone Fibers against Gram-Positive and Gram-Negative Bacteria

    Directory of Open Access Journals (Sweden)

    Erick Pazos-Ortiz

    2017-01-01

    Full Text Available The adhesion ability and adaptability of bacteria, coupled with constant use of the same bactericides, have made the increase in the diversity of treatments against infections necessary. Nanotechnology has played an important role in the search for new ways to prevent and treat infections, including the use of metallic nanoparticles with antibacterial properties. In this study, we worked on the design of a composite of silver nanoparticles (AgNPS embedded in poly-epsilon-caprolactone nanofibers and evaluated its antimicrobial properties against various Gram-positive and Gram-negative microorganisms associated with drug-resistant infections. Polycaprolactone-silver composites (PCL-AgNPs were prepared in two steps. The first step consisted in the reduction in situ of Ag+ ions using N,N-dimethylformamide (DMF in tetrahydrofuran (THF solution, and the second step involved the simple addition of polycaprolactone before electrospinning process. Antibacterial activity of PCL-AgNPs nanofibers against E. coli, S. mutans, K. pneumoniae, S. aureus, P. aeruginosa, and B. subtilis was evaluated. Results showed sensibility of E. coli, K. pneumoniae, S. aureus, and P. aeruginosa, but not for B. subtilis and S. mutans. This antimicrobial activity of PCL-AgNPs showed significant positive correlations associated with the dose-dependent effect. The antibacterial property of the PCL/Ag nanofibers might have high potential medical applications in drug-resistant infections.

  20. Silver-doped manganese dioxide and trioxide nanoparticles inhibit both gram positive and gram negative pathogenic bacteria.

    Science.gov (United States)

    Kunkalekar, R K; Prabhu, M S; Naik, M M; Salker, A V

    2014-01-01

    Palladium, ruthenium and silver-doped MnO2 and silver doped Mn2O3 nanoparticles were synthesized by simple co-precipitation technique. SEM-TEM analysis revealed the nano-size of these synthesized samples. XPS data illustrates that Mn is present in 4+ and 3+ oxidation states in MnO2 and Mn2O3 respectively. Thermal analysis gave significant evidence for the phase changes with increasing temperature. Antibacterial activity of these synthesized nanoparticles on three Gram positive bacterial cultures (Staphylococcus aureus ATCC 6538, Streptococcus epidermis ATCC 12228, Bacillus subtilis ATCC 6633) and three Gram negative cultures (Escherichia coli ATCC 8739, Salmonella abony NCTC 6017 and Klebsiella pneumoniae ATCC 1003) was investigated using a disc diffusion method and live/dead assay. Only Ag-doped MnO2 and Ag-doped Mn2O3 nanoparticles showed antibacterial property against all six-test bacteria but Ag-doped MnO2 was found to be more effective than Ag-doped Mn2O3. Copyright © 2013 Elsevier B.V. All rights reserved.

  1. Nanoparticle targeting of Gram-positive and Gram-negative bacteria for magnetic-based separations of bacterial pathogens

    Science.gov (United States)

    Lu, Hoang D.; Yang, Shirley S.; Wilson, Brian K.; McManus, Simon A.; Chen, Christopher V. H.-H.; Prud'homme, Robert K.

    2017-04-01

    Antimicrobial resistance is a healthcare problem of increasing significance, and there is increasing interest in developing new tools to address bacterial infections. Bacteria-targeting nanoparticles hold promise to improve drug efficacy, compliance, and safety. In addition, nanoparticles can also be used for novel applications, such as bacterial imaging or bioseperations. We here present the use of a scalable block-copolymer-directed self-assembly process, Flash NanoPrecipitation, to form zinc(II)-bis(dipicolylamine) modified nanoparticles that bind to both Gram-positive and Gram-negative bacteria with specificity. Particles have tunable surface ligand densities that change particle avidity and binding efficacy. A variety of materials can be encapsulated into the core of the particles, such as optical dyes or iron oxide colloids, to produce imageable and magnetically active bacterial targeting constructs. As a proof-of-concept, these particles are used to bind and separate bacteria from solution in a magnetic column. Magnetic manipulation and separation would translate to a platform for pathogen identification or removal. These magnetic and targeted nanoparticles enable new methods to address bacterial infections.

  2. Inhibition of various gram-positive and gram-negative bacteria growth on selenium nanoparticle coated paper towels.

    Science.gov (United States)

    Wang, Qi; Larese-Casanova, Philip; Webster, Thomas J

    2015-01-01

    There are wide spread bacterial contamination issues on various paper products, such as paper towels hanging in sink splash zones or those used to clean surfaces, filter papers used in water and air purifying systems, and wrappings used in the food industry; such contamination may lead to the potential spread of bacteria and consequent severe health concerns. In this study, selenium nanoparticles were coated on normal paper towel surfaces through a quick precipitation method, introducing antibacterial properties to the paper towels in a healthy way. Their effectiveness at preventing biofilm formation was tested in bacterial assays involving Staphylococcus aureus, Pseudomonas aeruginosa, Escherichia coli, and Staphylococcus epidermidis. The results showed significant and continuous bacteria inhibition with about a 90% reduction from 24 to 72 hours for gram-positive bacteria including S. aureus and S. epidermidis. The selenium coated paper towels also showed significant inhibition of gram-negative bacteria like P. aeruginosa and E. coli growth at about 57% and 84%, respectively, after 72 hours of treatment. Therefore, this study established a promising selenium-based antibacterial strategy to prevent bacterial growth on paper products, which may lead to the avoidance of bacteria spreading and consequent severe health concerns.

  3. Gram-positive bacteria as an antigen topically applied into gingival sulcus of immunized rat accelerates periodontal destruction.

    Science.gov (United States)

    Nagano, F; Kaneko, T; Yoshinaga, Y; Ukai, T; Kuramoto, A; Nakatsu, S; Oshino, K; Ichimura, I; Hara, Y

    2013-08-01

    Periodontitis is generally accepted to relate to gram-negative bacteria, and the host defense system influences its onset and progression. However, little is known about the relation between gram-positive bacteria and periodontitis. In this study, we topically applied gram-positive and gram-negative bacterial suspensions to the gingival sulcus in rats after immunization, and then histopathologically examined their influence on periodontal destruction. Rats previously immunized with heat-treated and sonicated Staphylococcus aureus or Aggregatibacter actinomycetemcomitans were used as immunized groups. The non-immunized group received only sterile phosphate-buffered saline. In each animal, S. aureus or A. actinomycetemcomitans suspension was applied topically to the palatal gingival sulcus of first molars every 24 h for 10 d. Blood samples were collected and the serum level of anti-S. aureus or anti-A. actinomycetemcomitans immunoglobulin G (IgG) antibodies was determined by enzyme-linked immunosorbent assay. The first molar regions were resected and observed histopathologically. Osteoclasts were stained with tartrate-resistant acid phosphatase (TRAP). The formation of immune complexes was confirmed by immunohistological staining of C1qB. Serum levels of anti-S. aureus and anti-A. actinomycetemcomitans IgG antibodies in the immunized groups were significantly higher than those in the non-immunized groups were. The loss of attachment, increase in apical migration of the junctional epithelium, and decreases in alveolar bone level and number of TRAP-positive multinuclear cells in each immunized group were significantly greater than in each non-immunized group. The presence of C1qB was observed in the junctional epithelium and adjacent connective tissue in the immunized groups. Heat-treated and sonicated S. aureus and A. actinomycetemcomitans induced attachment loss in rats immunized with their suspensions. Our results suggest that not only gram-negative but also gram

  4. Multicenter validation of the VITEK MS v2.0 MALDI-TOF mass spectrometry system for the identification of fastidious gram-negative bacteria.

    Science.gov (United States)

    Branda, John A; Rychert, Jenna; Burnham, Carey-Ann D; Bythrow, Maureen; Garner, Omai B; Ginocchio, Christine C; Jennemann, Rebecca; Lewinski, Michael A; Manji, Ryhana; Mochon, A Brian; Procop, Gary W; Richter, Sandra S; Sercia, Linda F; Westblade, Lars F; Ferraro, Mary Jane

    2014-02-01

    The VITEK MS v2.0 MALDI-TOF mass spectrometry system's performance in identifying fastidious gram-negative bacteria was evaluated in a multicenter study. Compared with the reference method (DNA sequencing), the VITEK MS system provided an accurate, species-level identification for 96% of 226 isolates; an additional 1% were accurately identified to the genus level. © 2013.

  5. The TFPI-2 derived peptide EDC34 improves outcome of gram-negative sepsis.

    Science.gov (United States)

    Papareddy, Praveen; Kalle, Martina; Sørensen, Ole E; Malmsten, Martin; Mörgelin, Matthias; Schmidtchen, Artur

    2013-01-01

    Sepsis is characterized by a dysregulated host-pathogen response, leading to high cytokine levels, excessive coagulation and failure to eradicate invasive bacteria. Novel therapeutic strategies that address crucial pathogenetic steps during infection are urgently needed. Here, we describe novel bioactive roles and therapeutic anti-infective potential of the peptide EDC34, derived from the C-terminus of tissue factor pathway inhibitor-2 (TFPI-2). This peptide exerted direct bactericidal effects and boosted activation of the classical complement pathway including formation of antimicrobial C3a, but inhibited bacteria-induced activation of the contact system. Correspondingly, in mouse models of severe Escherichia coli and Pseudomonas aeruginosa infection, treatment with EDC34 reduced bacterial levels and lung damage. In combination with the antibiotic ceftazidime, the peptide significantly prolonged survival and reduced mortality in mice. The peptide's boosting effect on bacterial clearance paired with its inhibiting effect on excessive coagulation makes it a promising therapeutic candidate for invasive Gram-negative infections.

  6. Green synthesis of silver nanoparticles using methanolic root extracts of Diospyros paniculata and their antimicrobial activities

    International Nuclear Information System (INIS)

    Rao, N.Hanumanta; Lakshmidevi, N.; Pammi, S.V.N.; Kollu, Pratap; Ganapaty, S.; Lakshmi, P.

    2016-01-01

    Since the discovery and subsequent widespread use of antibiotics, a variety of bacterial species of human and animal origin have developed numerous mechanisms that render bacteria resistant to some, and in certain cases to nearly all antibiotics, thereby limiting the treatment options and compromising effective therapy. In the present study, the green synthesis of nanoparticles is carried out by the reduction of silver acetate in the presence of crude methanolic root extracts of Diospyros paniculata, a member of family Ebenaceae. The UV–Vis absorption spectrum of the biologically reduced reaction mixture showed the surface plasmon peak at 428 nm, a characteristic peak of silver nanoparticles. X-ray diffraction (XRD) analysis confirmed the face-centered cubic crystalline structure of metallic silver. The average diameter of Ag NPs is about 17 nm from Transmission Electron Microscopy (TEM) which is in good agreement with the average crystallite size (19 nm) calculated from XRD analysis. Further the study has been extended to the antimicrobial activity against test pathogenic Gram (+), Gram (−) bacterial and fungal strains. The biologically synthesized silver nanoparticles showed promising activity against all the tested pathogenic strains and the activity has been enhanced with the increased dose levels. - Highlights: • Biosynthesis of silver nanoparticles (Ag NPs) using root extracts of Diospyros paniculata. • Average diameter of Ag NPs is about 17 nm from TEM analysis which is in good agreement with XRD analysis. • Antimicrobial activities of root extract mediated synthesis of silver Ag NPs were discussed in detail.

  7. Green synthesis of silver nanoparticles using methanolic root extracts of Diospyros paniculata and their antimicrobial activities

    Energy Technology Data Exchange (ETDEWEB)

    Rao, N.Hanumanta [Advanced Analytical Laboratory, DST-PURSE Programme, Andhra University, Visakhapatnam 530003 (India); Lakshmidevi, N. [Department of Microbiology, College of Science and Technology, Andhra University, Visakhapatnam 530003 (India); Pammi, S.V.N. [Advanced Analytical Laboratory, DST-PURSE Programme, Andhra University, Visakhapatnam 530003 (India); Department of Materials Science and Engineering, Chungnam National University, Daeduk Science Town, 305-764, Daejeon (Korea, Republic of); Kollu, Pratap [DST-INSPIRE Faculty, Department of Metallurgical Engineering & Materials Science, Indian Institute of Technology Bombay, Mumbai 400076 (India); Ganapaty, S. [GITAM Institute of Pharmacy, GITAM University, Visakhapatnam (India); Lakshmi, P., E-mail: lmkandregula@gmail.com [Department of Microbiology, College of Science and Technology, Andhra University, Visakhapatnam 530003 (India)

    2016-05-01

    Since the discovery and subsequent widespread use of antibiotics, a variety of bacterial species of human and animal origin have developed numerous mechanisms that render bacteria resistant to some, and in certain cases to nearly all antibiotics, thereby limiting the treatment options and compromising effective therapy. In the present study, the green synthesis of nanoparticles is carried out by the reduction of silver acetate in the presence of crude methanolic root extracts of Diospyros paniculata, a member of family Ebenaceae. The UV–Vis absorption spectrum of the biologically reduced reaction mixture showed the surface plasmon peak at 428 nm, a characteristic peak of silver nanoparticles. X-ray diffraction (XRD) analysis confirmed the face-centered cubic crystalline structure of metallic silver. The average diameter of Ag NPs is about 17 nm from Transmission Electron Microscopy (TEM) which is in good agreement with the average crystallite size (19 nm) calculated from XRD analysis. Further the study has been extended to the antimicrobial activity against test pathogenic Gram (+), Gram (−) bacterial and fungal strains. The biologically synthesized silver nanoparticles showed promising activity against all the tested pathogenic strains and the activity has been enhanced with the increased dose levels. - Highlights: • Biosynthesis of silver nanoparticles (Ag NPs) using root extracts of Diospyros paniculata. • Average diameter of Ag NPs is about 17 nm from TEM analysis which is in good agreement with XRD analysis. • Antimicrobial activities of root extract mediated synthesis of silver Ag NPs were discussed in detail.

  8. Plant sterol ester diet supplementation increases serum plant sterols and markers of cholesterol synthesis, but has no effect on total cholesterol levels.

    Science.gov (United States)

    Weingärtner, Oliver; Bogeski, Ivan; Kummerow, Carsten; Schirmer, Stephan H; Husche, Constanze; Vanmierlo, Tim; Wagenpfeil, Gudrun; Hoth, Markus; Böhm, Michael; Lütjohann, Dieter; Laufs, Ulrich

    2017-05-01

    This double-blind, randomized, placebo-controlled, cross-over intervention-study was conducted in healthy volunteers to evaluate the effects of plant sterol ester supplemented margarine on cholesterol, non-cholesterol sterols and oxidative stress in serum and monocytes. Sixteen volunteers, average age 34 years, with no or mild hypercholesterolemia were subjected to a 4 week period of daily intake of 3g plant sterols per day supplied via a supplemented margarine on top of regular eating habits. After a wash-out period of one week, volunteers switched groups. Compared to placebo, a diet supplementation with plant sterols increased serum levels of plant sterols such as campesterol (+0.16±0.19mg/dL, p=0.005) and sitosterol (+0.27±0.18mg/dL, psynthesis such as desmosterol (+0.05±0.07mg/dL, p=0.006) as well as lathosterol (+0.11±0.16mg/dL, p=0.012). Cholesterol serum levels, however, were not changed significantly (+18.68±32.6mg/dL, p=0.052). These findings could not be verified in isolated circulating monocytes. Moreover, there was no effect on monocyte activation and no differences with regard to redox state after plant sterol supplemented diet. Therefore, in a population of healthy volunteers with no or mild hypercholesterolemia, consumption of plant sterol ester supplemented margarine results in increased concentrations of plant sterols and cholesterol synthesis markers without affecting total cholesterol in the serum, activation of circulating monocytes or redox state. Copyright © 2016 Elsevier Ltd. All rights reserved.

  9. Cyclic Di-GMP Binding by an Assembly ATPase (PilB2) and Control of Type IV Pilin Polymerization in the Gram-Positive Pathogen Clostridium perfringens.

    Science.gov (United States)

    Hendrick, William A; Orr, Mona W; Murray, Samantha R; Lee, Vincent T; Melville, Stephen B

    2017-05-15

    polymerizing the pilin, PilA2, into a pilus. The assembly ATPase PilB2 and its cognate membrane protein partner, PilC2, were purified. PilB2 bound the intracellular signal molecule c-di-GMP. Increased levels of intracellular c-di-GMP led to increased polymerization of PilA2, indicating that Gram-positive bacteria use this molecule to regulate pilus synthesis. These findings provide valuable information for understanding how pathogenic clostridia regulate TFP to cause human diseases. Copyright © 2017 American Society for Microbiology.

  10. The gram-negative bacterial periplasm: Size matters.

    Directory of Open Access Journals (Sweden)

    Samuel I Miller

    2018-01-01

    Full Text Available Gram-negative bacteria are surrounded by two membrane bilayers separated by a space termed the periplasm. The periplasm is a multipurpose compartment separate from the cytoplasm whose distinct reducing environment allows more efficient and diverse mechanisms of protein oxidation, folding, and quality control. The periplasm also contains structural elements and important environmental sensing modules, and it allows complex nanomachines to span the cell envelope. Recent work indicates that the size or intermembrane distance of the periplasm is controlled by periplasmic lipoproteins that anchor the outer membrane to the periplasmic peptidoglycan polymer. This periplasm intermembrane distance is critical for sensing outer membrane damage and dictates length of the flagellar periplasmic rotor, which controls motility. These exciting results resolve longstanding debates about whether the periplasmic distance has a biological function and raise the possibility that the mechanisms for maintenance of periplasmic size could be exploited for antibiotic development.

  11. Sinus surgery postpones chronic Gram-negative lung infection

    DEFF Research Database (Denmark)

    Alanin, M C; Aanaes, K; Høiby, N

    2016-01-01

    of pulmonary samples positive for GNB. We investigated whether the effect is sustained. METHODOLOGY: We report the effect of ESS and adjuvant therapy three years postoperatively in a CF cohort participating in this prospective clinical follow-up study. The primary endpoint was the lung infection status defined......BACKGROUND: In patients with cystic fibrosis (CF) the sinuses are a bacterial reservoir for Gram-negative bacteria (GNB). From the sinuses the GNB can repeatedly migrate to the lungs. In a one-year follow-up study, endoscopic sinus surgery (ESS) with adjuvant therapy reduced the frequency....... The total cohort had decreasing lung function during follow-up; however, in 27 patients with improved lung infection status lung function was stable. Revision surgery was performed in 31 patients (28%). CONCLUSION: ESS with adjuvant therapy significantly improves the lung infection status for at least three...

  12. Marine Compounds with Therapeutic Potential in Gram-Negative Sepsis

    Directory of Open Access Journals (Sweden)

    Irina Yermak

    2013-06-01

    Full Text Available This paper concerns the potential use of compounds, including lipid A, chitosan, and carrageenan, from marine sources as agents for treating endotoxemic complications from Gram-negative infections, such as sepsis and endotoxic shock. Lipid A, which can be isolated from various species of marine bacteria, is a potential antagonist of bacterial endotoxins (lipopolysaccharide (LPSs. Chitosan is a widespread marine polysaccharide that is derived from chitin, the major component of crustacean shells. The potential of chitosan as an LPS-binding and endotoxin-neutralizing agent is also examined in this paper, including a discussion on the generation of hydrophobic chitosan derivatives to increase the binding affinity of chitosan to LPS. In addition, the ability of carrageenan, which is the polysaccharide of red alga, to decrease the toxicity of LPS is discussed. We also review data obtained using animal models that demonstrate the potency of carrageenan and chitosan as antiendotoxin agents.

  13. A study of gram-negative bacterial resistance to Aminoglycosides

    Directory of Open Access Journals (Sweden)

    Maleknejad P

    1993-05-01

    Full Text Available From hygienic and economical point of view, drug therapy and prophylaxy in infectious diseases are of great importance. After the world war II, a reduction in the efficacy of sulfonamide in the treatment of shigellosis was observed and later on it led to a survey on drug resistance and the way of its transmission. The aim of this survey, during which 100 cases of gram-negative bacteria were identified, is to study the drug resistance of this bacteria against five types of aminoglycosides by antibiotic sensitivity test (disc-diffusion. Out of 100 strains, 47% were resistant to gentamycin, 70% to kanamycin, 82% to streptomycin, 53% to tobramycin, and 8% to amikacin

  14. Transient sensitivity to nisin in cold-shocked Gram negatives.

    Science.gov (United States)

    Boziaris, I S; Adams, M R

    2000-09-01

    Rapid chilling in the presence of nisin caused a dose-dependent reduction in the populations of several Gram-negative bacteria, despite the fact that appreciable structural injury to the outer membrane was not detected. Pseudomonas aeruginosa was most affected, followed by Pseudomonas fragi, Salmonella enteritidis PT4, PT7 and Escherichia coli, respectively. Addition of nisin after the chilling treatment had no effect. The results are ascribed to a transient susceptibility caused by phase changes in the lipids associated with the outer membrane, which are rapidly reversed when the cells return to higher temperatures. Combinations of chilling shock, nisin and EDTA gave much lower reductions of Salmonella and Pseudomonas on chicken skin in comparison with broths. This is attributed to a buffering of the temperature shock experienced by adherent bacteria and binding of the nisin by food particles.

  15. Distribution of Gram Negative Bacteria and Evaluation of Resistance Profiles

    Directory of Open Access Journals (Sweden)

    Serap Pamukcuoglu

    2014-03-01

    Full Text Available Aim: In this study, we aimed to examine the distributon of Gram negative bacteria isolated from urine cultures of out-patients in Afyonkarahisar State Hospital and evaluate the antimicrobial resistance rates of these pathogens. Material and Method: Urine samples of out-patients which were sent to microbiology laboratory between 2012-2013 were retrospectively evaluated. The isolates were identified using conventional methods and/or automated Vitec 2.0 system. Antibiogram sensitivities were determined by Kirby-Bauer disc diffusion method or automated system and interpreted on the basis of Clinical and Laboratory Standards Institute (CSI criteria. Double disc sinergy test (DDST or Vitec 2.0 system was used to detect extended spectrum beta-lactamase (ESBL.When conventional methods could%u2019t be clarified according to their colony morphologies, gram staining patterns, biochemical test; automated system has been used. Results: A total of 671 isolates acquired from urine samples were studied. 427 Escherichia coli (63.6 %, 165 Klebsiella spp. (24.6 %, 22 Pseudomonas spp. (3.3 %, nine Acinetobacter spp. (1.3 %, 41 Proteus spp. (6.1 % and seven Serratia (1.0 % strains were identified among isolates. 97 E.coli (22.8 % and 41 Klebsiella (24.8 % isolates were ESBL positive. Most common bacteria were E.coli, 31.1 % of which were resistant to trimethoprim-sulfamethoxazole, 16 % to ciprofloxacin and 3.6 % to nitrofurantoin. Among Enterobacteriaceae, no resistance aganist carbapenems were detected. Moreover, aminoglicoside sensitivity rate was significantly high in this group. Discussion: Microorganisms that have progressively increasing antimicrobial resistance should be considered in the treatment of urinary tract infections. It is also important to use the most appropriate antibiotics to avoid unnecessary usage of these drugs in order to decrease drug resistance rates and ESBL production which may effect the success of the treatment.

  16. Gram-Negative Bacterial Sensors for Eukaryotic Signal Molecules

    Directory of Open Access Journals (Sweden)

    Olivier Lesouhaitier

    2009-09-01

    Full Text Available Ample evidence exists showing that eukaryotic signal molecules synthesized and released by the host can activate the virulence of opportunistic pathogens. The sensitivity of prokaryotes to host signal molecules requires the presence of bacterial sensors. These prokaryotic sensors, or receptors, have a double function: stereospecific recognition in a complex environment and transduction of the message in order to initiate bacterial physiological modifications. As messengers are generally unable to freely cross the bacterial membrane, they require either the presence of sensors anchored in the membrane or transporters allowing direct recognition inside the bacterial cytoplasm. Since the discovery of quorum sensing, it was established that the production of virulence factors by bacteria is tightly growth-phase regulated. It is now obvious that expression of bacterial virulence is also controlled by detection of the eukaryotic messengers released in the micro-environment as endocrine or neuro-endocrine modulators. In the presence of host physiological stress many eukaryotic factors are released and detected by Gram-negative bacteria which in return rapidly adapt their physiology. For instance, Pseudomonas aeruginosa can bind elements of the host immune system such as interferon-γ and dynorphin and then through quorum sensing circuitry enhance its virulence. Escherichia coli sensitivity to the neurohormones of the catecholamines family appears relayed by a recently identified bacterial adrenergic receptor. In the present review, we will describe the mechanisms by which various eukaryotic signal molecules produced by host may activate Gram-negative bacteria virulence. Particular attention will be paid to Pseudomonas, a genus whose representative species, P. aeruginosa, is a common opportunistic pathogen. The discussion will be particularly focused on the pivotal role played by these new types of pathogen sensors from the sensing to the transduction

  17. Synthesis of 6-Methyl-9-n-propyldibenzothiophene-4-ol

    Energy Technology Data Exchange (ETDEWEB)

    Eisenbraun, E.J.

    1991-04-27

    The material covered here can be divided into 3 parts: large-scale synthesis of 200+ grams of distilled 1,4-diethyl-2-[(2'- methoxyphenyl)thio]benzene, synthesis of sulfones both as starting materials for chemical cyclization reactions and as solid derivatives for identification purposes, and continued investigation of the cyclization to dibenzothiophenes both by chemical and photochemical means. 5 refs, figs.

  18. Metabolic and process engineering for biodesulfurization in Gram-negative bacteria.

    Science.gov (United States)

    Martínez, I; El-Said Mohamed, M; Santos, V E; García, J L; García-Ochoa, F; Díaz, E

    2017-11-20

    Microbial desulfurization or biodesulfurization (BDS) is an attractive low-cost and environmentally friendly complementary technology to the hydrotreating chemical process based on the potential of certain bacteria to specifically remove sulfur from S-heterocyclic compounds of crude fuels that are recalcitrant to the chemical treatments. The 4S or Dsz sulfur specific pathway for dibenzothiophene (DBT) and alkyl-substituted DBTs, widely used as model S-heterocyclic compounds, has been extensively studied at the physiological, biochemical and genetic levels mainly in Gram-positive bacteria. Nevertheless, several Gram-negative bacteria have been also used in BDS because they are endowed with some properties, e.g., broad metabolic versatility and easy genetic and genomic manipulation, that make them suitable chassis for systems metabolic engineering strategies. A high number of recombinant bacteria, many of which are Pseudomonas strains, have been constructed to overcome the major bottlenecks of the desulfurization process, i.e., expression of the dsz operon, activity of the Dsz enzymes, retro-inhibition of the Dsz pathway, availability of reducing power, uptake-secretion of substrate and intermediates, tolerance to organic solvents and metals, and other host-specific limitations. However, to attain a BDS process with industrial applicability, it is necessary to apply all the knowledge and advances achieved at the genetic and metabolic levels to the process engineering level, i.e., kinetic modelling, scale-up of biphasic systems, enhancing mass transfer rates, biocatalyst separation, etc. The production of high-added value products derived from the organosulfur material present in oil can be regarded also as an economically viable process that has barely begun to be explored. Copyright © 2017 Elsevier B.V. All rights reserved.

  19. An extreme-halophile archaebacterium possesses the interlock type of prephenate dehydratase characteristic of the Gram-positive eubacteria

    Science.gov (United States)

    Jensen, R. A.; d'Amato, T. A.; Hochstein, L. I.

    1988-01-01

    The focal point of phenylalanine biosynthesis is a dehydratase reaction which in different organisms may be prephenate dehydratase, arogenate dehydratase, or cyclohexadienyl dehydratase. Gram-positive, Gram-negative, and cyanobacterial divisions of the eubacterial kingdom exhibit different dehydratase patterns. A new extreme-halophile isolate, which grows on defined medium and is tentatively designated as Halobacterium vallismortis CH-1, possesses the interlock type of prephenate dehydratase present in Gram-positive bacteria. In addition to the conventional sensitivity to feedback inhibition by L-phenylalanine, the phenomenon of metabolic interlock was exemplified by the sensitivity of prephenate dehydratase to allosteric effects produced by extra-pathway (remote) effectors. Thus, L-tryptophan inhibited activity while L-tyrosine, L-methionine, L-leucine and L-isoleucine activated the enzyme. L-Isoleucine and L-phenylalanine were effective at micromolar levels; other effectors operated at mM levels. A regulatory mutant selected for resistance to growth inhibition caused by beta-2-thienylalanine possessed an altered prephenate dehydratase in which a phenomenon of disproportionately low activity at low enzyme concentration was abolished. Inhibition by L-tryptophan was also lost, and activation by allosteric activators was diminished. Not only was sensitivity to feedback inhibition by L-phenylalanine lost, but the mutant enzyme was now activated by this amino acid (a mutation type previously observed in Bacillus subtilis). It remains to be seen whether this type of prephenate dehydratase will prove to be characteristic of all archaebacteria or of some archaebacterial subgroup cluster.

  20. Flow cytometric evaluation of physico-chemical impact on Gram-positive and Gram-negative bacteria

    Science.gov (United States)

    Fröhling, Antje; Schlüter, Oliver

    2015-01-01

    Since heat sensitivity of fruits and vegetables limits the application of thermal inactivation processes, new emerging inactivation technologies have to be established to fulfill the requirements of food safety without affecting the produce quality. The efficiency of inactivation treatments has to be ensured and monitored. Monitoring of inactivation effects is commonly performed using traditional cultivation methods which have the disadvantage of the time span needed to obtain results. The aim of this study was to compare the inactivation effects of peracetic acid (PAA), ozonated water (O3), and cold atmospheric pressure plasma (CAPP) on Gram-positive and Gram-negative bacteria using flow cytometric methods. E. coli cells were completely depolarized after treatment (15 s) with 0.25% PAA at 10°C, and after treatment (10 s) with 3.8 mg l−1 O3 at 12°C. The membrane potential of CAPP treated cells remained almost constant at an operating power of 20 W over a time period of 3 min, and subsequently decreased within 30 s of further treatment. Complete membrane permeabilization was observed after 10 s O3 treatment, but treatment with PAA and CAPP did not completely permeabilize the cells within 2 and 4 min, respectively. Similar results were obtained for esterase activity. O3 inactivates cellular esterase but esterase activity was detected after 4 min CAPP treatment and 2 min PAA treatment. L. innocua cells and P. carotovorum cells were also permeabilized instantaneously by O3 treatment at concentrations of 3.8 ± 1 mg l−1. However, higher membrane permeabilization of L. innocua and P. carotovorum than of E. coli was observed at CAPP treatment of 20 W. The degree of bacterial damage due to the inactivation processes is highly dependent on treatment parameters as well as on treated bacteria. Important information regarding the inactivation mechanisms can be obtained by flow cytometric measurements and this enables the definition of critical process parameters. PMID

  1. Flow cytometric evaluation of physico-chemical impact on Gram-positive and Gram-negative bacteria

    Directory of Open Access Journals (Sweden)

    Antje eFröhling

    2015-09-01

    Full Text Available Since heat sensitivity of fruits and vegetables limits the application of thermal inactivation processes, new emerging inactivation technologies have to be established to fulfil the requirements of food safety without affecting the produce quality. The efficiency of inactivation treatments has to be ensured and monitored. Monitoring of inactivation effects is commonly performed using traditional cultivation methods which have the disadvantage of the time span needed to obtain results.The aim of this study was to compare the inactivation effects of peracetic acid (PAA, ozonated water (O3 and cold atmospheric pressure plasma (CAPP on Gram-positive and Gram-negative bacteria using flow cytometric methods. E. coli cells were completely depolarized after treatment (15 s with 0.25 % PAA at 10 °C, and after treatment (10 s with 3.8 mg l-1 O3 at 12°C. The membrane potential of CAPP treated cells remained almost constant at an operating power of 20 W over a time period of 3 min, and subsequently decreased within 30 s of further treatment. Complete membrane permeabilization was observed after 10 s O3 treatment, but treatment with PAA and CAPP did not completely permeabilize the cells within 2 min and 4 min, respectively. Similar results were obtained for esterase activity. O3 inactivates cellular esterase but esterase activity was detected after 4 min CAPP treatment and 2 min PAA treatment. L. innocua cells and P. carotovorum cells were also permeabilized instantaneously by O3 treatment at concentrations of 3.8 ± 1 mg l-1. However, higher membrane permeabilization of L. innocua and P. carotovorum than of E. coli was observed at CAPP treatment of 20 W. The degree of bacterial damage due to the inactivation processes is highly dependent on treatment parameters as well as on treated bacteria. Important information regarding the inactivation mechanisms can be obtained by flow cytometric measurements and this enables the definition of critical process

  2. Antibacterial activity and interactions of plant essential oil combinations against Gram-positive and Gram-negative bacteria

    Directory of Open Access Journals (Sweden)

    Cristina Anamaria Semeniuc

    2017-04-01

    Full Text Available The aim of this study was to compare the antibacterial effects of several essential oils (EOs alone and in combination against different Gram-positive and Gram-negative bacteria associated with food products. Parsley, lovage, basil, and thyme EOs, as well as their mixtures (1:1, v/v, were tested against Bacillus cereus, Staphylococcus aureus, Pseudomonas aeruginosa, Escherichia coli, and Salmonella typhimurium. The inhibitory effects ranged from strong (thyme EO against E. coli to no inhibition (parsley EO against P. aeruginosa. Thyme EO exhibited strong (against E. coli, moderate (against S. typhimurium and B. cereus, or mild inhibitory effects (against P. aeruginosa and S. aureus, and basil EO showed mild (against E. coli and B. cereus or no inhibitory effects (against S. typhimurium, P. aeruginosa, and S. aureus. Parsley and lovage EOs revealed no inhibitory effects against all tested strains. Combinations of lovage/thyme and basil/thyme EOs displayed antagonistic effects against all bacteria, parsley/thyme EOs against B. cereus, S. aureus, P. aeruginosa, and E. coli, and lovage/basil EOs against B. cereus and E. coli. Combinations of parsley/lovage and parsley/basil EOs exhibited indifferent effects against all bacteria. The combination of lovage/basil EO showed indifferent effect against S. aureus, P. aeruginosa, and S. typhimurium, and the combination parsley/thyme EO against S. typhimurium. Thyme EO has the highest percentage yield and antibacterial potential from all tested formulations; its combination with parsley, lovage, and basil EOs determines a reduction of its antibacterial activity. Hence, it is recommended to be used alone as the antibacterial agent.

  3. An unusual class of anthracyclines potentiate Gram-positive antibiotics in intrinsically resistant Gram-negative bacteria.

    Science.gov (United States)

    Cox, Georgina; Koteva, Kalinka; Wright, Gerard D

    2014-07-01

    An orthogonal approach taken towards novel antibacterial drug discovery involves the identification of small molecules that potentiate or enhance the activity of existing antibacterial agents. This study aimed to identify natural-product rifampicin adjuvants in the intrinsically resistant organism Escherichia coli. E. coli BW25113 was screened against 1120 actinomycete fermentation extracts in the presence of subinhibitory (2 mg/L) concentrations of rifampicin. The active molecule exhibiting the greatest rifampicin potentiation was isolated using activity-guided methods and identified using mass and NMR spectroscopy. Susceptibility testing and biochemical assays were used to determine the mechanism of antibiotic potentiation. The anthracycline Antibiotic 301A(1) was isolated from the fermentation broth of a strain of Streptomyces (WAC450); the molecule was shown to be highly synergistic with rifampicin (fractional inhibitory concentration index = 0.156) and moderately synergistic with linezolid (FIC index = 0.25) in both E. coli and Acinetobacter baumannii. Activity was associated with inhibition of efflux and the synergistic phenotype was lost when tested against E. coli harbouring mutations within the rpoB gene. Structure-activity relationship studies revealed that other anthracyclines do not synergize with rifampicin and removal of the sugar moiety of Antibiotic 301A(1) abolishes activity. Screening only a subsection of our natural product library identified a small-molecule antibiotic adjuvant capable of sensitizing Gram-negative bacteria to antibiotics to which they are ordinarily intrinsically resistant. This result demonstrates the great potential of this approach in expanding antibiotic effectiveness in the face of the growing challenge of resistance in Gram-negatives. © The Author 2014. Published by Oxford University Press on behalf of the British Society for Antimicrobial Chemotherapy. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

  4. An unusual class of anthracyclines potentiate Gram-positive antibiotics in intrinsically resistant Gram-negative bacteria

    Science.gov (United States)

    Cox, Georgina; Koteva, Kalinka; Wright, Gerard D.

    2014-01-01

    Objectives An orthogonal approach taken towards novel antibacterial drug discovery involves the identification of small molecules that potentiate or enhance the activity of existing antibacterial agents. This study aimed to identify natural-product rifampicin adjuvants in the intrinsically resistant organism Escherichia coli. Methods E. coli BW25113 was screened against 1120 actinomycete fermentation extracts in the presence of subinhibitory (2 mg/L) concentrations of rifampicin. The active molecule exhibiting the greatest rifampicin potentiation was isolated using activity-guided methods and identified using mass and NMR spectroscopy. Susceptibility testing and biochemical assays were used to determine the mechanism of antibiotic potentiation. Results The anthracycline Antibiotic 301A1 was isolated from the fermentation broth of a strain of Streptomyces (WAC450); the molecule was shown to be highly synergistic with rifampicin (fractional inhibitory concentration index = 0.156) and moderately synergistic with linezolid (FIC index = 0.25) in both E. coli and Acinetobacter baumannii. Activity was associated with inhibition of efflux and the synergistic phenotype was lost when tested against E. coli harbouring mutations within the rpoB gene. Structure–activity relationship studies revealed that other anthracyclines do not synergize with rifampicin and removal of the sugar moiety of Antibiotic 301A1 abolishes activity. Conclusions Screening only a subsection of our natural product library identified a small-molecule antibiotic adjuvant capable of sensitizing Gram-negative bacteria to antibiotics to which they are ordinarily intrinsically resistant. This result demonstrates the great potential of this approach in expanding antibiotic effectiveness in the face of the growing challenge of resistance in Gram-negatives. PMID:24627312

  5. Type I and Type II mechanisms of antimicrobial photodynamic therapy: an in vitro study on gram-negative and gram-positive bacteria.

    Science.gov (United States)

    Huang, Liyi; Xuan, Yi; Koide, Yuichiro; Zhiyentayev, Timur; Tanaka, Masamitsu; Hamblin, Michael R

    2012-08-01

    Antimicrobial photodynamic therapy (APDT) employs a non-toxic photosensitizer (PS) and visible light, which in the presence of oxygen produce reactive oxygen species (ROS), such as singlet oxygen ((1) O(2), produced via Type II mechanism) and hydroxyl radical (HO(.), produced via Type I mechanism). This study examined the relative contributions of (1) O(2) and HO(.) to APDT killing of Gram-positive and Gram-negative bacteria. Fluorescence probes, 3'-(p-hydroxyphenyl)-fluorescein (HPF) and singlet oxygen sensor green reagent (SOSG) were used to determine HO(.) and (1) O(2) produced by illumination of two PS: tris-cationic-buckminsterfullerene (BB6) and a conjugate between polyethylenimine and chlorin(e6) (PEI-ce6). Dimethylthiourea is a HO(.) scavenger, while sodium azide (NaN(3)) is a quencher of (1) O(2). Both APDT and killing by Fenton reaction (chemical generation of HO(.)) were carried out on Gram-positive bacteria (Staphylococcus aureus and Enterococcus faecalis) and Gram-negative bacteria (Escherichia coli, Proteus mirabilis, and Pseudomonas aeruginosa). Conjugate PEI-ce6 mainly produced (1) O(2) (quenched by NaN(3)), while BB6 produced HO(.) in addition to (1) O(2) when NaN(3) potentiated probe activation. NaN(3) also potentiated HPF activation by Fenton reagent. All bacteria were killed by Fenton reagent but Gram-positive bacteria needed a higher concentration than Gram-negatives. NaN(3) potentiated Fenton-mediated killing of all bacteria. The ratio of APDT killing between Gram-positive and Gram-negative bacteria was 2 or 4:1 for BB6 and 25:1 for conjugate PEI-ce6. There was a NaN(3) dose-dependent inhibition of APDT killing using both PEI-ce6 and BB6 against Gram-negative bacteria while NaN(3) almost failed to inhibit killing of Gram-positive bacteria. Azidyl radicals may be formed from NaN(3) and HO(.). It may be that Gram-negative bacteria are more susceptible to HO(.) while Gram-positive bacteria are more susceptible to (1) O(2). The differences in Na

  6. Utility of gram staining for evaluation of the quality of cystic fibrosis sputum samples.

    Science.gov (United States)

    Nair, Bindu; Stapp, Jenny; Stapp, Lynn; Bugni, Linda; Van Dalfsen, Jill; Burns, Jane L

    2002-08-01

    The microscopic examination of Gram-stained sputum specimens is very helpful in the evaluation of patients with community-acquired pneumonia and has also been recommended for use in cystic fibrosis (CF) patients. This study was undertaken to evaluate that recommendation. One hundred one sputum samples from CF patients were cultured for gram-negative bacilli and examined by Gram staining for both sputum adequacy (using the quality [Q] score) and bacterial morphology. Subjective evaluation of adequacy was also performed and categorized. Based on Q score evaluation, 41% of the samples would have been rejected despite a subjective appearance of purulence. Only three of these rejected samples were culture negative for gram-negative CF pathogens. Correlation between culture results and quantitative Gram stain examination was also poor. These data suggest that subjective evaluation combined with comprehensive bacteriology is superior to Gram staining in identifying pathogens in CF sputum.

  7. Potential strategies for the eradication of multidrug-resistant Gram-negative bacterial infections.

    Science.gov (United States)

    Huwaitat, Rawan; McCloskey, Alice P; Gilmore, Brendan F; Laverty, Garry

    2016-07-01

    Antimicrobial resistance is one of the leading threats to society. The increasing burden of multidrug-resistant Gram-negative infection is particularly concerning as such bacteria are demonstrating resistance to nearly all currently licensed therapies. Various strategies have been hypothesized to treat multidrug-resistant Gram-negative infections including: targeting the Gram-negative outer membrane; neutralization of lipopolysaccharide; inhibition of bacterial efflux pumps and prevention of protein folding. Silver and silver nanoparticles, fusogenic liposomes and nanotubes are potential strategies for extending the activity of licensed, Gram-positive selective, antibiotics to Gram-negatives. This may serve as a strategy to fill the current void in pharmaceutical development in the short term. This review outlines the most promising strategies that could be implemented to solve the threat of multidrug-resistant Gram-negative infections.

  8. Survival and detection of coliforms, Enterobacteriaceae, and gram-negative bacteria in Greek yogurt.

    Science.gov (United States)

    Hervert, C J; Martin, N H; Boor, K J; Wiedmann, M

    2017-02-01

    Despite the widespread use of coliforms as indicator bacteria, increasing evidence suggests that the Enterobacteriaceae (EB) and total gram-negative groups more accurately reflect the hygienic status of high-temperature, short-time pasteurized milk and processing environments. If introduced into milk as postpasteurization contamination, these bacteria may grow to high levels and produce a wide range of sensory-related defects. However, limited information is available on the use and survival of bacterial hygiene indicators in dairy products outside of pasteurized fluid milk and cheese. The goal of this study was to (1) provide information on the survival of a diverse set of bacterial hygiene indicators in the low pH environment of Greek yogurt, (2) compare traditional and alternative detection methods for their ability to detect bacterial hygiene indicators in Greek yogurt, and (3) offer insight into optimal hygiene indicator groups for use in low-pH fermented dairy products. To this end, we screened 64 bacterial isolates, representing 24 dairy-relevant genera, for survival and detection in Greek yogurt using 5 testing methods. Before testing, isolates were inoculated into plain, 0% fat Greek yogurt (pH 4.35 to 4.65), followed by a 12-h hold period at 4 ± 1°C. Yogurts were subsequently tested using Coliform Petrifilm (3M, St. Paul, MN) to detect coliforms; Enterobacteriaceae Petrifilm (3M), violet red bile glucose agar and the D-Count (bioMérieux, Marcy-l'Étoile, France) to detect EB; and crystal violet tetrazolium agar (CVTA) to detect total gram-negative bacteria. Overall, the non-EB gram-negative isolates showed significantly larger log reductions 12 h after inoculation into Greek yogurt (based on bacterial numbers recovered on CVTA) compared with the coliform and noncoliform EB isolates tested. The methods evaluated varied in their ability to detect different microbial hygiene indicators in Greek yogurt. Crystal violet tetrazolium agar detected the highest

  9. Characterization of carbapenem-resistant Gram-negative bacteria from Tamil Nadu.

    Science.gov (United States)

    Nachimuthu, Ramesh; Subramani, Ramkumar; Maray, Suresh; Gothandam, K M; Sivamangala, Karthikeyan; Manohar, Prasanth; Bozdogan, Bülent

    2016-10-01

    Carbapenem resistance is disseminating worldwide among Gram-negative bacteria. The aim of this study was to identify carbapenem-resistance level and to determine the mechanism of carbapenem resistance among clinical isolates from two centres in Tamil Nadu. In the present study, a total of 93 Gram-negative isolates, which is found to be resistant to carbapenem by disk diffusion test in two centres, were included. All isolates are identified at species level by 16S rRNA sequencing. Minimal inhibitory concentrations (MICs) of isolates for Meropenem were tested by agar dilution method. Presence of blaOXA, blaNDM, blaVIM, blaIMP and blaKPC genes was tested by PCR in all isolates. Amplicons were sequenced for confirmation of the genes. Among 93 isolates, 48 (%52) were Escherichia coli, 10 (%11) Klebsiella pneumoniae, nine (%10) Pseudomonas aeruginosa. Minimal inhibitory concentration results showed that of 93 suspected carbapenem-resistant isolates, 27 had meropenem MICs ≥ 2 μg/ml. The MIC range, MIC50 and MIC90 were 128 μg/ml, 0.12 and 16 μg/ml, respectively. Fig. 1 . Among meropenem-resistant isolates, E. coli were the most common (9/48, 22%), followed by K. pneumoniae (7/9, 77%), P. aeruginosa (6/10, 60%), Acinetobacter baumannii (2/2, 100%), Enterobacter hormaechei (2/3, 67%) and one Providencia rettgeri (1/1, 100%). PCR results showed that 16 of 93 carried blaNDM, three oxa181, and one imp4. Among blaNDM carriers, nine were E. coli, four Klebsiella pneumoniae, two E. hormaechei and one P. rettgeri. Three K. pneumoniae were OXA-181 carriers. The only imp4 carrier was P. aeruginosa. A total of seven carbapenem-resistant isolates were negatives by PCR for the genes studied. All carbapenem-resistance gene-positive isolates had meropenem MICs >2 μg/ml. Our results confirm the dissemination of NDM and emergence of OXA-181 beta-lactamase among Gram-negative bacteria in South India. This study showed the emergence of NDM producer in clinical isolates of E

  10. Laser synthesis of a copper–single-walled carbon nanotube nanocomposite via molecular-level mixing and non-equilibrium solidification

    International Nuclear Information System (INIS)

    Tu, Jay F; Rajule, Nilesh; Molian, Pal; Liu, Yi

    2016-01-01

    A copper–single-walled carbon nanotube (Cu–SWCNT) metal nanocomposite could be an ideal material if it can substantially improve the strength of copper while preserving the metal’s excellent thermal and electrical properties. However, synthesis of such a nanocomposite is highly challenging, because copper and SWCNTs do not form intermetallic compounds and are insoluble; as a result, there are serious issues regarding wettability and fine dispersion of SWCNTs within the copper matrix. In this paper we present a novel wet process, called the laser surface implantation process (LSI), to synthesize Cu–SWCNT nanocomposites by mixing SWCNTs into molten copper. The LSI process includes drilling several microholes on a copper substrate, filling the microholes with SWCNTs suspended in solution, and melting the copper substrate to create a micro-well of molten copper. The molten copper advances radially outward to engulf the microholes with pre-deposited SWCNTs to form the Cu–SWCNT implant upon solidification. Rapid and non-equilibrium solidification is achieved due to copper’s excellent heat conductivity, so that SWCNTs are locked in position within the copper matrix without agglomerating into large clusters. This wet process is very different from the typical dry processes used in powder metallurgy. Very high hardness improvement, up to 527% over pure copper, was achieved, confirmed by micro-indentation tests, with only a 0.23% SWCNT volume fraction. The nanostructure of the nanocomposite was characterized by TEM imaging, energy-dispersive x-ray spectroscopy mapping and spectroscopy measurements. The SWCNTs were found to be finely dispersed within the copper matrix with cluster sizes in the range of nanometers, achieving the goal of molecular-level mixing. (paper)

  11. The target of daptomycin is absent from Escherichia coli and other gram-negative pathogens.

    Science.gov (United States)

    Randall, Christopher P; Mariner, Katherine R; Chopra, Ian; O'Neill, Alex J

    2013-01-01

    Antistaphylococcal agents commonly lack activity against Gram-negative bacteria like Escherichia coli owing to the permeability barrier presented by the outer membrane and/or the action of efflux transporters. When these intrinsic resistance mechanisms are artificially compromised, such agents almost invariably demonstrate antibacterial activity against Gram negatives. Here we show that this is not the case for the antibiotic daptomycin, whose target appears to be absent from E. coli and other Gram-negative pathogens.

  12. Studies on mutagenic effect on genetic variability in green gram (Vigna radiata (L. ) Wilczek)

    Energy Technology Data Exchange (ETDEWEB)

    Krishnaswami, S; Rathinam, M [Tamil Nadu Agricultural Univ. Coimbatore (India). Dept. of Agricultural Botany

    1982-03-01

    With a view to finding out the effect of mutagenic treatments on heritability in green gram, two cultivars, showing extremes of sensitivity to mutagen, were subjected to two levels each of gamma irradiation and EMS separately and conjointly and the M/sub 2/ generation raised. Families of the higher dose in each treatment were advanced to the M/sub 3/ and the genetic parameters of the various growth and yield attributes, besides seed yield, studied. Barring plant height, heritability of all other traits registered an increase under the mutagen effect. No consistency was evident in the superiority of one mutagen over the other, their behaviour varying with the cultivar and the character studied. Consequent to enhancement in heritability, correlations between the characters underwent alterations under the mutagens.

  13. A 3 Year-Old Male Child Ingested Approximately 750 Grams of Elemental Mercury

    Directory of Open Access Journals (Sweden)

    Metin Uysalol

    2016-08-01

    Full Text Available Background: The oral ingestion of elemental mercury is unlikely to cause systemic toxicity, as it is poorly absorbed through the gastrointestinal system. However, abnormal gastrointestinal function or anatomy may allow elemental mercury into the bloodstream and the peritoneal space. Systemic effects of massive oral intake of mercury have rarely been reported. Case Report: In this paper, we are presenting the highest ingle oral intake of elemental mercury by a child aged 3 years. A Libyan boy aged 3 years ingested approximately 750 grams of elemental mercury and was still asymptomatic. Conclusion: The patient had no existing disease or abnormal gastrointestinal function or anatomy. The physical examination was normal. His serum mercury level was 91 μg/L (normal: <5 μg/L, and he showed no clinical manifestations. Exposure to mercury in children through different circumstances remains a likely occurrence.

  14. A New Family of Capsule Polymerases Generates Teichoic Acid-Like Capsule Polymers in Gram-Negative Pathogens.

    Science.gov (United States)

    Litschko, Christa; Oldrini, Davide; Budde, Insa; Berger, Monika; Meens, Jochen; Gerardy-Schahn, Rita; Berti, Francesco; Schubert, Mario; Fiebig, Timm

    2018-05-29

    Group 2 capsule polymers represent crucial virulence factors of Gram-negative pathogenic bacteria. They are synthesized by enzymes called capsule polymerases. In this report, we describe a new family of polymerases that combine glycosyltransferase and hexose- and polyol-phosphate transferase activity to generate complex poly(oligosaccharide phosphate) and poly(glycosylpolyol phosphate) polymers, the latter of which display similarity to wall teichoic acid (WTA), a cell wall component of Gram-positive bacteria. Using modeling and multiple-sequence alignment, we showed homology between the predicted polymerase domains and WTA type I biosynthesis enzymes, creating a link between Gram-negative and Gram-positive cell wall biosynthesis processes. The polymerases of the new family are highly abundant and found in a variety of capsule-expressing pathogens such as Neisseria meningitidis , Actinobacillus pleuropneumoniae , Haemophilus influenzae , Bibersteinia trehalosi , and Escherichia coli with both human and animal hosts. Five representative candidates were purified, their activities were confirmed using nuclear magnetic resonance (NMR) spectroscopy, and their predicted folds were validated by site-directed mutagenesis. IMPORTANCE Bacterial capsules play an important role in the interaction between a pathogen and the immune system of its host. During the last decade, capsule polymerases have become attractive tools for the production of capsule polymers applied as antigens in glycoconjugate vaccine formulations. Conventional production of glycoconjugate vaccines requires the cultivation of the pathogen and thus the highest biosafety standards, leading to tremendous costs. With regard to animal husbandry, where vaccines could avoid the extensive use of antibiotics, conventional production is not sufficiently cost-effective. In contrast, enzymatic synthesis of capsule polymers is pathogen-free and fast, offers high stereo- and regioselectivity, and works with high efficacy

  15. Benefits from antidepressants: synthesis of 6-week patient-level outcomes from double-blind placebo-controlled randomized trials of fluoxetine and venlafaxine.

    Science.gov (United States)

    Gibbons, Robert D; Hur, Kwan; Brown, C Hendricks; Davis, John M; Mann, J John

    2012-06-01

    Some meta-analyses suggest that efficacy of antidepressants for major depression is overstated and limited to severe depression. To determine the short-term efficacy of antidepressants for treating major depressive disorder in youth, adult, and geriatric populations. Reanalysis of all intent-to-treat person-level longitudinal data during the first 6 weeks of treatment of major depressive disorder from 12 adult, 4 geriatric, and 4 youth randomized controlled trials of fluoxetine hydrochloride and 21 adult trials of venlafaxine hydrochloride. All sponsor-conducted randomized controlled trials of fluoxetine and venlafaxine. Children's Depression Rating Scale-Revised scores (youth population), Hamilton Depression Rating Scale scores (adult and geriatric populations), and estimated response and remission rates at 6 weeks were analyzed for 2635 adults, 960 geriatric patients, and 708 youths receiving fluoxetine and for 2421 adults receiving immediate-release venlafaxine and 2461 adults receiving extended-release venlafaxine. Patients in all age and drug groups had significantly greater improvement relative to control patients receiving placebo. The differential rate of improvement was largest for adults receiving fluoxetine (34.6% greater than those receiving placebo). Youths had the largest treated vs control difference in response rates (24.1%) and remission rates (30.1%), with adult differences generally in the 15.6% (remission) to 21.4% (response) range. Geriatric patients had the smallest drug-placebo differences, an 18.5% greater rate of improvement, 9.9% for response and 6.5% for remission. Immediate-release venlafaxine produced larger effects than extended-release venlafaxine. Baseline severity could not be shown to affect symptom reduction. To our knowledge, this is the first research synthesis in this area to use complete longitudinal person-level data from a large set of published and unpublished studies. The results do not support previous findings that

  16. Three and six grams supplementation of d-aspartic acid in resistance trained men.

    Science.gov (United States)

    Melville, Geoffrey W; Siegler, Jason C; Marshall, Paul Wm

    2015-01-01

    Although abundant research has investigated the hormonal effects of d-aspartic acid in rat models, to date there is limited research on humans. Previous research has demonstrated increased total testosterone levels in sedentary men and no significant changes in hormonal levels in resistance trained men. It was hypothesised that a higher dosage may be required for experienced lifters, thus this study investigated the effects of two different dosages of d-aspartic acid on basal hormonal levels in resistance trained men and explored responsiveness to d-aspartic acid based on initial testosterone levels. Twenty-four males, with a minimum of two years' experience in resistance training, (age, 24.5 ± 3.2 y; training experience, 3.4 ± 1.4 y; height, 178.5 ± 6.5 cm; weight, 84.7 ± 7.2 kg; bench press 1-RM, 105.3 ± 15.2 kg) were randomised into one of three groups: 6 g.d(-1) plain flour (D0); 3 g.d(-1) of d-aspartic acid (D3); and 6 g.d(-1) of d-aspartic acid (D6). Participants performed a two-week washout period, training four days per week. This continued through the experimental period (14 days), with participants consuming the supplement in the morning. Serum was analysed for levels of testosterone, estradiol, sex hormone binding globulin, albumin and free testosterone was determined by calculation. D-aspartic acid supplementation revealed no main effect for group in: estradiol; sex-hormone-binding-globulin; and albumin. Total testosterone was significantly reduced in D6 (P = 0.03). Analysis of free testosterone showed that D6 was significantly reduced as compared to D0 (P = 0.005), but not significantly different to D3. Analysis did not reveal any significant differences between D3 and D0. No significant correlation between initial total testosterone levels and responsiveness to d-aspartic acid was observed (r = 0.10, P = 0.70). The present study demonstrated that a daily dose of six grams of d-aspartic acid decreased

  17. Querying and Serving N-gram Language Models with Python

    Directory of Open Access Journals (Sweden)

    2009-06-01

    Full Text Available Statistical n-gram language modeling is a very important technique in Natural Language Processing (NLP and Computational Linguistics used to assess the fluency of an utterance in any given language. It is widely employed in several important NLP applications such as Machine Translation and Automatic Speech Recognition. However, the most commonly used toolkit (SRILM to build such language models on a large scale is written entirely in C++ which presents a challenge to an NLP developer or researcher whose primary language of choice is Python. This article first provides a gentle introduction to statistical language modeling. It then describes how to build a native and efficient Python interface (using SWIG to the SRILM toolkit such that language models can be queried and used directly in Python code. Finally, it also demonstrates an effective use case of this interface by showing how to leverage it to build a Python language model server. Such a server can prove to be extremely useful when the language model needs to be queried by multiple clients over a network: the language model must only be loaded into memory once by the server and can then satisfy multiple requests. This article includes only those listings of source code that are most salient. To conserve space, some are only presented in excerpted form. The complete set of full source code listings may be found in Volume 1 of The Python Papers Source Codes Journal.

  18. Streptococcus mutans: a new Gram-positive paradigm?

    Science.gov (United States)

    Quivey, Robert G.; Koo, Hyun; Abranches, Jacqueline

    2013-01-01

    Despite the enormous contributions of the bacterial paradigms Escherichia coli and Bacillus subtilis to basic and applied research, it is well known that no single organism can be a perfect representative of all other species. However, given that some bacteria are difficult, or virtually impossible, to cultivate in the laboratory, that some are recalcitrant to genetic and molecular manipulation, and that others can be extremely dangerous to manipulate, the use of model organisms will continue to play an important role in the development of basic research. In particular, model organisms are very useful for providing a better understanding of the biology of closely related species. Here, we discuss how the lifestyle, the availability of suitable in vitro and in vivo systems, and a thorough understanding of the genetics, biochemistry and physiology of the dental pathogen Streptococcus mutans have greatly advanced our understanding of important areas in the field of bacteriology such as interspecies biofilms, competence development and stress responses. In this article, we provide an argument that places S. mutans, an organism that evolved in close association with the human host, as a novel Gram-positive model organism. PMID:23393147

  19. Genetic improvement of black gram using induced mutations

    International Nuclear Information System (INIS)

    Pawar, S.E.; Manjaya, J.G.; Souframanien, J.; Bhatkar, S.M.

    2000-01-01

    Induced mutagenesis is an important tool for creating genetic variability in crop plants and has played a significant role in the development of many crop varieties. Genetic improvement of black gram (Vigna mungo L. Hepper) through induced mutations has been in progress at BARC for the past three decades. Mutation studies of genotype EC-168200 have resulted in isolating large number of mutants with distinct morphological characters. TAU-5, an early maturing mutant was identified as a resistant donor for yellow mosaic virus (YMV) disease by the All India Pulse Improvement Project, ICAR, Kanpur. TAU-5 was used in cross breeding with elite cultivars like T-9, TPU-4 and LBG-17. Twelve selections with high yield potential suitable for both kharif and rabi cultivation have been developed. One of the selections TU94-2 has been released for commercial cultivation for southern zone during 1999. The work on the development of YMV resistant genotypes is in progress and will be discussed. (author)

  20. Detection and Antibiotic Susceptibility Pattern of Biofilm Producing Gram Positive and Gram Negative Bacteria Isolated From a Tertiary Care Hospital of Pakistan

    Directory of Open Access Journals (Sweden)

    Iqbal, M.

    2011-01-01

    Full Text Available Microorganisms adhere to non-living material or living tissue, and form biofilms made up of extracellular polymers/slime. Biofilm-associated microorganisms behave differently from free-floating bacteria with respect to growth rates and ability to resist antimicrobial treatments and therefore pose a public health problem. The objective of this study is to detect the prevalence of biofilm producers among Gram positive and Gram negative bacteria isolated from clinical specimens, and to study their antimicrobial susceptibility pattern. The study was carried out from October 2009 to March 2010, at the Department of Microbiology, Army Medical College/ National University of Sciences and Technology (NUST, Rawalpindi, Pakistan. Clinical specimens were received from various wards of a tertiary care hospital. These were dealt by standard microbiological procedures. Gram positive and Gram negative bacteria isolated were subjected to biofilm detection by congo red agar method (CRA. Antimicrobial susceptibility testing of those isolates, which showed positive results (slime production, was done according to the Kirby-Bauer disc diffusion technique. A total of 150 isolates were tested for the production of biofilm/slime. Among them, 81 isolates showed positive results. From these 81, 51 were Gram positive and 30 were Gram negative. All the 81(54% slime producers showed reduced susceptibility to majority of antibiotics. Bacterial biofilms are an important virulence factor associated with chronic nosocomial infection. Detection of biofilm forming organisms can help in appropriate antibiotic choice.

  1. ClubSub-P: Cluster-based subcellular localization prediction for Gram-negative bacteria and Archaea.

    Directory of Open Access Journals (Sweden)

    Nagarajan eParamasivam

    2011-11-01

    Full Text Available The subcellular localization of proteins provides important clues to their function in a cell. In our efforts to predict useful vaccine targets against Gram-negative bacteria, we noticed that misannotated start codons frequently lead to wrongly assigned subcellular localizations. This and other problems in subcellular localization prediction, such as the relatively high false positive and false negative rates of some tools, can be avoided by applying multiple prediction tools to groups of homologous proteins. Here we present ClubSub-P, an online database that combines existing subcellular localization prediction tools into a consensus pipeline from more than 600 proteomes of fully sequenced microorganisms. On top of the consensus prediction at the level of single sequences, the tool uses clusters of homologous proteins from Gram-negative bacteria and from Archaea to eliminate false positive and false negative predictions. ClubSub-P can assign the subcellular localization of proteins from Gram-negative bacteria and Archaea with high precision. The database is searchable, and can easily be expanded using either new bacterial genomes or new prediction tools as they become available. This will further improve the performance of the subcellular localization prediction, as well as the detection of misannotated start codons and other annotation errors. ClubSub-P is available online at http://toolkit.tuebingen.mpg.de/clubsubp/

  2. ClubSub-P: Cluster-Based Subcellular Localization Prediction for Gram-Negative Bacteria and Archaea

    Science.gov (United States)

    Paramasivam, Nagarajan; Linke, Dirk

    2011-01-01

    The subcellular localization (SCL) of proteins provides important clues to their function in a cell. In our efforts to predict useful vaccine targets against Gram-negative bacteria, we noticed that misannotated start codons frequently lead to wrongly assigned SCLs. This and other problems in SCL prediction, such as the relatively high false-positive and false-negative rates of some tools, can be avoided by applying multiple prediction tools to groups of homologous proteins. Here we present ClubSub-P, an online database that combines existing SCL prediction tools into a consensus pipeline from more than 600 proteomes of fully sequenced microorganisms. On top of the consensus prediction at the level of single sequences, the tool uses clusters of homologous proteins from Gram-negative bacteria and from Archaea to eliminate false-positive and false-negative predictions. ClubSub-P can assign the SCL of proteins from Gram-negative bacteria and Archaea with high precision. The database is searchable, and can easily be expanded using either new bacterial genomes or new prediction tools as they become available. This will further improve the performance of the SCL prediction, as well as the detection of misannotated start codons and other annotation errors. ClubSub-P is available online at http://toolkit.tuebingen.mpg.de/clubsubp/ PMID:22073040

  3. Antimicrobial Peptide Potency is Facilitated by Greater Conformational Flexibility when Binding to Gram-negative Bacterial Inner Membranes

    Science.gov (United States)

    Amos, Sarah-Beth T. A.; Vermeer, Louic S.; Ferguson, Philip M.; Kozlowska, Justyna; Davy, Matthew; Bui, Tam T.; Drake, Alex F.; Lorenz, Christian D.; Mason, A. James

    2016-11-01

    The interaction of antimicrobial peptides (AMPs) with the inner membrane of Gram-negative bacteria is a key determinant of their abilities to exert diverse bactericidal effects. Here we present a molecular level understanding of the initial target membrane interaction for two cationic α-helical AMPs that share structural similarities but have a ten-fold difference in antibacterial potency towards Gram-negative bacteria. The binding and insertion from solution of pleurocidin or magainin 2 to membranes representing the inner membrane of Gram-negative bacteria, comprising a mixture of 128 anionic and 384 zwitterionic lipids, is monitored over 100 ns in all atom molecular dynamics simulations. The effects of the membrane interaction on both the peptide and lipid constituents are considered and compared with new and published experimental data obtained in the steady state. While both magainin 2 and pleurocidin are capable of disrupting bacterial membranes, the greater potency of pleurocidin is linked to its ability to penetrate within the bacterial cell. We show that pleurocidin displays much greater conformational flexibility when compared with magainin 2, resists self-association at the membrane surface and penetrates further into the hydrophobic core of the lipid bilayer. Conformational flexibility is therefore revealed as a key feature required of apparently α-helical cationic AMPs for enhanced antibacterial potency.

  4. Bactérias gram negativas resistentes a antimicrobianos em alimentos Gram-negative bacteria resistant to antibiotics in foods

    Directory of Open Access Journals (Sweden)

    José Cavalcante de Albuquerque Ribeiro Dias

    1985-12-01

    Full Text Available A partir de 154 espécimens de alimentos, representados por hortaliças (alface, leite e merenda escolar, obteve-se o isolamento e identificação de 400 amostras de bacilos Gram negativos. Esta amostragem se distribuiu em 339 enterobactérias (Escherichia, Shigella, Citrobacter, Klebsiella, Enterobacter, Serratia e Proteus e 61 de gêneros afins (Acinetobacter, Flavobacterium, Aeromonas e Pseudomonas. Submetendo-se as culturas aos antimicrobianos: sulfadiazina (Su, estreptomicina (Sm, tetraciclina (Tc, cloranfenicol (Cm, canamicina (Km, ampicilina (Ap, ácido nalidíxico (Nal e gentamicina (Gm, observou-se apenas seis estirpes sensíveis a todas as drogas e sensibilidade absoluta à Gm. A predominância dos modelos Su (27,6% e Su-Ap (39,6% incidiu nas enterobactérias, enquanto que, 18,0% para Ap e 9,8% para Su-Ap foram detectados nos gêneros afins. Para caracterização da resistência foram realizados testes de conjugação e a totalidade das culturas não revelou transferência para o gene que confere resistência ao ácido nalidíxico. Relevantes são as taxas de amostras R+ observadas nos bacilos entéricos, oscilando em torno de 90% (leite e merenda escolar e alface, em torno de 70%From 154 food samples, including vegetables (lettuce, milk and meals served at school it was possible to isolate and identify 400 Gram negative bacilli distributed among 339 enteric bacteria (Escherichia, Shigella, Citrobacter, Klebsiella, Enterobacter, Serratia and Proteus and other 61 non enteric bacilli (Acinetobacter, Flavobacterium, Aeromonas and Pseudomonas. Submitting this cultures to the drugs sulfadiazine (Su, streptomycin (Sm, tetracycline (Tc, chloramphenicol (Cm, kanamycin (Km, ampicillin (Ap, nalidixic acid (Nal and gentamycin (Gm it was observed only six stocks susceptible to all drugs and total sensibility to Gm. Among enteric bacteria the profiles Su (27,6% and Su-Ap (39,6% predominated, while for the non enteric bacilli percentages of 18.0 for

  5. Lack of clinical utility of urine gram stain for suspected urinary tract infection in pediatric patients.

    Science.gov (United States)

    Cantey, Joseph B; Gaviria-Agudelo, Claudia; McElvania TeKippe, Erin; Doern, Christopher D

    2015-04-01

    Urinary tract infection (UTI) is one of the most common infections in children. Urine culture remains the gold standard for diagnosis, but the utility of urine Gram stain relative to urinalysis (UA) is unclear. We reviewed 312 pediatric patients with suspected UTI who had urine culture, UA, and urine Gram stain performed from a single urine specimen. UA was considered positive if ≥10 leukocytes per oil immersion field were seen or if either nitrates or leukocyte esterase testing was positive. Urine Gram stain was considered positive if any organisms were seen. Sensitivity, specificity, and positive and negative predictive values were calculated using urine culture as the gold standard. Thirty-seven (12%) patients had a culture-proven UTI. Compared to urine Gram stain, UA had equal sensitivity (97.3% versus 97.5%) and higher specificity (85% versus 74%). Empirical therapy was prescribed before the Gram stain result was known in 40 (49%) patients and after in 42 (51%) patients. The antibiotics chosen did not differ between the two groups (P=0.81), nor did they differ for patients with Gram-negative rods on urine Gram stain compared to those with Gram-positive cocci (P=0.67). From these data, we conclude that UA has excellent negative predictive value that is not enhanced by urine Gram stain and that antibiotic selection did not vary based on the urine Gram stain result. In conclusion, the clinical utility of urine Gram stain does not warrant the time or cost it requires. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

  6. Effects of rhodomyrtone on Gram-positive bacterial tubulin homologue FtsZ

    Directory of Open Access Journals (Sweden)

    Dennapa Saeloh

    2017-02-01

    Full Text Available Rhodomyrtone, a natural antimicrobial compound, displays potent activity against many Gram-positive pathogenic bacteria, comparable to last-defence antibiotics including vancomycin and daptomycin. Our previous studies pointed towards effects of rhodomyrtone on the bacterial membrane and cell wall. In addition, a recent molecular docking study suggested that the compound could competitively bind to the main bacterial cell division protein FtsZ. In this study, we applied a computational approach (in silico, in vitro, and in vivo experiments to investigate molecular interactions of rhodomyrtone with FtsZ. Using molecular simulation, FtsZ conformational changes were observed in both (S- and (R-rhodomyrtone binding states, compared with the three natural states of FtsZ (ligand-free, GDP-, and GTP-binding states. Calculations of free binding energy showed a higher affinity of FtsZ to (S-rhodomyrtone (−35.92 ± 0.36 kcal mol−1 than the GDP substrate (−23.47 ± 0.25 kcal mol−1 while less affinity was observed in the case of (R-rhodomyrtone (−18.11 ± 0.11 kcal mol−1. In vitro experiments further revealed that rhodomyrtone reduced FtsZ polymerization by 36% and inhibited GTPase activity by up to 45%. However, the compound had no effect on FtsZ localization in Bacillus subtilis at inhibitory concentrations and cells also did not elongate after treatment. Higher concentrations of rhodomyrtone did affect localization of FtsZ and also affected localization of its membrane anchor proteins FtsA and SepF, showing that the compound did not specifically inhibit FtsZ but rather impaired multiple divisome proteins. Furthermore, a number of cells adopted a bean-like shape suggesting that rhodomyrtone possibly possesses further targets involved in cell envelope synthesis and/or maintenance.

  7. Synthesis of Some Novel Biologically Active Disperse Dyes Derived from 4-Methyl-2,6-dioxo-1-propyl-1,2,5,6-tetrahydro-pyridine-3-carbonitrile as Coupling Component and Their Colour Assessment on Polyester Fabrics

    Directory of Open Access Journals (Sweden)

    Mohamed H. Elnagdi

    2012-07-01

    Full Text Available A series of novel azo-disperse dyes containing alkylhydrazonopyridinone structures were synthesized. 4-Methyl-2,6-dioxo-1-propyl-1,2,5,6-tetrahydropyridine-3-carbonitrile (8 is synthesized by one-pot synthesis using ethyl cyanoacetate, propylamine, and ethyl acetoacetate. Compound 8 is then coupled with aromatic and heteroaromatic diazonium salts to afford the corresponding aryl- and heteroaryl-4-methyl-2,6-dioxo-1-propyl-1,2,5,6-tetrahydropyridine-3-carbonitriles 12a,b and 13a–c. Structural assignments to the dyes were made using NMR spectroscopic methods. A high temperature dyeing method was employed to apply these dyes to polyester fabrics. Most of the dyed fabrics tested displayed very good light fastness levels and good wash fastness. Finally, the biological activity of the prepared dyes against Gram positive bacteria and Gram negative bacteria were evaluated.

  8. Characterization and analysis of CCR and CAD gene families at the whole-genome level for lignin synthesis of stone cells in pear (Pyrus bretschneideri) fruit.

    Science.gov (United States)

    Cheng, Xi; Li, Manli; Li, Dahui; Zhang, Jinyun; Jin, Qing; Sheng, Lingling; Cai, Yongping; Lin, Yi

    2017-11-15

    The content of stone cells has significant effects on the flavour and quality of pear fruit. Previous research suggested that lignin deposition is closely related to stone cell formation. In the lignin biosynthetic pathway, cinnamoyl-CoA reductase (CCR) and cinnamyl alcohol dehydrogenase (CAD), dehydrogenase/reductase family members, catalyse the last two steps in monolignol synthesis. However, there is little knowledge of the characteristics of the CCR and CAD families in pear and their involvement in lignin synthesis of stone cells. In this study, 31 CCR s and 26 CAD s were identified in the pear genome. Phylogenetic trees for CCR s and CAD s were constructed; key amino acid residues were analysed, and three-dimensional structures were predicted. Using quantitative real-time polymerase chain reaction (qRT-PCR), PbCAD2 , PbCCR1 , -2 and - 3 were identified as participating in lignin synthesis of stone cells in pear fruit. Subcellular localization analysis showed that the expressed proteins (PbCAD2, PbCCR1, -2 and -3) are found in the cytoplasm or at the cell membrane. These results reveal the evolutionary features of the CCR and CAD families in pear as well as the genes responsible for regulation of lignin synthesis and stone cell development in pear fruit. © 2017. Published by The Company of Biologists Ltd.

  9. Characterization and analysis of CCR and CAD gene families at the whole-genome level for lignin synthesis of stone cells in pear (Pyrus bretschneideri fruit

    Directory of Open Access Journals (Sweden)

    Xi Cheng

    2017-11-01

    Full Text Available The content of stone cells has significant effects on the flavour and quality of pear fruit. Previous research suggested that lignin deposition is closely related to stone cell formation. In the lignin biosynthetic pathway, cinnamoyl-CoA reductase (CCR and cinnamyl alcohol dehydrogenase (CAD, dehydrogenase/reductase family members, catalyse the last two steps in monolignol synthesis. However, there is little knowledge of the characteristics of the CCR and CAD families in pear and their involvement in lignin synthesis of stone cells. In this study, 31 CCRs and 26 CADs were identified in the pear genome. Phylogenetic trees for CCRs and CADs were constructed; key amino acid residues were analysed, and three-dimensional structures were predicted. Using quantitative real-time polymerase chain reaction (qRT-PCR, PbCAD2, PbCCR1, -2 and -3 were identified as participating in lignin synthesis of stone cells in pear fruit. Subcellular localization analysis showed that the expressed proteins (PbCAD2, PbCCR1, -2 and -3 are found in the cytoplasm or at the cell membrane. These results reveal the evolutionary features of the CCR and CAD families in pear as well as the genes responsible for regulation of lignin synthesis and stone cell development in pear fruit.

  10. A Comparison of Heat versus Methanol Fixation for Gram Staining Bacteria

    Science.gov (United States)

    Minnerath, Jeanne M.; Roland, Jenna M.; Rossi, Lucas C.; Weishalla, Steven R.; Wolf, Melissa M.

    2009-01-01

    Gram staining bacteria is a fundamental technique introduced in general biology and microbiology laboratory courses. Two common problems students encounter when Gram staining bacteria are (1) having a difficult time locating bacterial cells on the microscope slide and (2) over-decolorizing bacterial cells during the staining procedure such that…

  11. Tundmatud kohad ja asjade loomus / Katrine Gram Sloth, Johna Hansen ; intervjueerinud Laura Põld

    Index Scriptorium Estoniae

    Gram Sloth, Katrine, 1983-

    2016-01-01

    Taani kunstnik Katrine Gram Sloth ja Rootsi arhitekt Johna Hansen räägivad oma lapsepõlvest, kunstnikuteest, loomingust. Johna Hanseni jaapanipärasest einelaua installatsioonist "Laud" (2015-2016), Katrine Gram Slothi Islandil loodud teosest "Vista Revisited" (2015)

  12. Gram-scale fractionation of nanodiamonds by density gradient ultracentrifugation

    KAUST Repository

    Peng, Wei

    2013-01-01

    Size is a defining characteristic of nanoparticles; it influences their optical and electronic properties as well as their interactions with molecules and macromolecules. Producing nanoparticles with narrow size distributions remains one of the main challenges to their utilization. At this time, the number of practical approaches to optimize the size distribution of nanoparticles in many interesting materials systems, including diamond nanocrystals, remains limited. Diamond nanocrystals synthesized by detonation protocols-so-called detonation nanodiamonds (DNDs)-are promising systems for drug delivery, photonics, and composites. DNDs are composed of primary particles with diameters mainly <10 nm and their aggregates (ca. 10-500 nm). Here, we introduce a large-scale approach to rate-zonal density gradient ultracentrifugation to obtain monodispersed fractions of nanoparticles in high yields. We use this method to fractionate a highly concentrated and stable aqueous solution of DNDs and to investigate the size distribution of various fractions by dynamic light scattering, analytical ultracentrifugation, transmission electron microscopy and powder X-ray diffraction. This fractionation method enabled us to separate gram-scale amounts of DNDs into several size ranges within a relatively short period of time. In addition, the high product yields obtained for each fraction allowed us to apply the fractionation method iteratively to a particular size range of particles and to collect various fractions of highly monodispersed primary particles. Our method paves the way for in-depth studies of the physical and optical properties, growth, and aggregation mechanism of DNDs. Applications requiring DNDs with specific particle or aggregate sizes are now within reach. © 2013 The Royal Society of Chemistry.

  13. Extended-spectrum ß-lactamases in gram negative bacteria

    Directory of Open Access Journals (Sweden)

    Deepti Rawat

    2010-01-01

    Full Text Available Extended-spectrum ß-lactamases (ESBLs are a group of plasmid-mediated, diverse, complex and rapidly evolving enzymes that are posing a major therapeutic challenge today in the treatment of hospitalized and community-based patients. Infections due to ESBL producers range from uncomplicated urinary tract infections to life-threatening sepsis. Derived from the older TEM is derived from Temoniera, a patient from whom the strain was first isolated in Greece. ß-lactamases, these enzymes share the ability to hydrolyze third-generation cephalosporins and aztreonam and yet are inhibited by clavulanic acid. In addition, ESBL-producing organisms exhibit co-resistance to many other classes of antibiotics, resulting in limitation of therapeutic option. Because of inoculum effect and substrate specificity, their detection is also a major challenge. At present, however, organizations such as the Clinical and Laboratory Standards Institute (formerly the National Committee for Clinical Laboratory Standards provide guidelines for the detection of ESBLs in Klebsiella pneumoniae, K. oxytoca, Escherichia coli and Proteus mirabilis. In common to all ESBL-detection methods is the general principle that the activity of extended-spectrum cephalosporins against ESBL-producing organisms will be enhanced by the presence of clavulanic acid. Carbapenems are the treatment of choice for serious infections due to ESBL-producing organisms, yet carbapenem-resistant isolates have recently been reported. ESBLs represent an impressive example of the ability of gram-negative bacteria to develop new antibiotic-resistance mechanisms in the face of the introduction of new antimicrobial agents. Thus there is need for efficient infection-control practices for containment of outbreaks; and intervention strategies, e.g., antibiotic rotation to reduce further selection and spread of these increasingly resistant pathogens.

  14. Synthesis of nanosheets of lead using leaf extracts of Momordica charantia and studies its antibacterial activity

    Science.gov (United States)

    Ramteke, A. A.; Kurade, S. S.

    2018-05-01

    In the present paper, we have carried out a green synthesis of lead nano materials (PbNMs) using extract of Momordica charantia. We have characterized nano materials by using scanning electron microscopy, x-ray diffraction and UV-visible spectroscopy. It is found that PbNMs show antibacterial activity against pathogenic bacteria of gram positive (S. aureus,) and gram negative strains (E. coli, P. aeruginosa) using well diffusion technique and gives reasonably interesting results.

  15. Comparison of Gram and Kopeloff stains in the diagnosis of bacterial vaginosis in pregnancy.

    Science.gov (United States)

    Libman, Michael D; Kramer, Michael; Platt, Robert

    2006-03-01

    Bacterial vaginosis (BV) is commonly diagnosed by using the Nugent score, a semiquantitative scoring system to evaluate bacterial morphotypes on Gram stain of vaginal secretions. Some authors have suggested using the Kopeloff modification of the Gram stain. Asymptomatic BV in pregnancy has been associated with adverse outcomes. We performed both stains on simultaneously collected vaginal smears from 2652 women at 24-26 weeks of gestation. Gram staining gave significantly higher (more abnormal) Nugent scores than Kopeloff staining. Compared to the Kopeloff stain, the number of specimens graded as indeterminate or consistent with BV by Gram stain increased by 29% (469 versus 364, Pstaining was significantly better than Gram staining (agreement=74% versus 63%, intraclass correlation coefficient=0.87 versus 0.79, P<.05, 95% confidence intervals 0.85-0.89 and 0.75-0.82, respectively).

  16. Gram-negative folliculitis. A rare problem or is it underdiagnosed? Case report and literature review

    Directory of Open Access Journals (Sweden)

    Sierra-Téllez Daniela, Ponce-Olivera Rosa María, Tirado-Sánchez Andrés

    2011-07-01

    Full Text Available AbstractGram-negative folliculitis may be the result of prolonged antibacterial treatments in patients with acne and rosacea. It is caused by alteration of facial skin flora and the nasal mucous, a decrease of Gram-positive bacteria and a proliferation of Gram-negative bacteria (for example Escherichia coli, Pseudomonas aeruginosa, Serratia marcescens, Klebsiella sp. and Proteus mirabilis. It should be considered in patients with acne who have not had a clinical improvement after 3-6 months of treatment with tetracyclines. The disease is underestimated, probably because bacteriological studies are rarely requested and the increased use of oral isotretinoin for acne management. One of the most effective treatments for Gram-negative folliculitis is oral isotretinoin (0.5-1 mg / kg / day for 4-5 months. We report the case of Gram negative folliculitis successfully treated with oral isotretinoin.

  17. A prospective study of the diagnostic utility of sputum Gram stain in pneumonia.

    Science.gov (United States)

    Anevlavis, Stavros; Petroglou, Niki; Tzavaras, Athanasios; Maltezos, Efstratios; Pneumatikos, Ioannis; Froudarakis, Marios; Anevlavis, Eleftherios; Bouros, Demosthenes

    2009-08-01

    Sputum Gram stain and culture have been said to be unreliable indicators of the microbiological diagnosis of bacterial pneumonia. The etiological diagnosis of pneumonia is surrounded by great degree of uncertainty. This uncertainty should be and can be calculated and incorporated in the diagnosis and treatment. To determine the diagnostic accuracy and diagnostic value of sputum Gram stain in etiological diagnosis and initial selection of antimicrobial therapy of bacterial community acquired pneumonia (CAP). DESIGN-METHOD: Prospective study of 1390 patients with CAP admitted January 2002-June 2008, to our institutions. Of the 1390 patients, 178 (12.8%) fulfilled the criteria for inclusion into this study (good-quality sputa and presence of the same microorganism in blood and sputum cultures which was used as gold standard for assessing the diagnostic accuracy and diagnostic value of sputum Gram stain). The sensitivity of sputum Gram stain was 0.82 for Pneumococcal pneumonia, 0.76 for Staphylococcal pneumonia, 0.79 for Haemophilus influenzae pneumonia and 0.78 for Gram-negative bacilli pneumonia. The specificity of sputum Gram stain was 0.93 for Pneumococcal pneumonia, 0.96 for Staphylococcal pneumonia, 0.96 for H. influenzae pneumonia and 0.95 for Gram-negative bacilli pneumonia. The positive likelihood ratio (LR+) was 11.58 for Pneumococcal pneumonia, 19.38 for Staphylococcal pneumonia, 16.84 for H. influenzae pneumonia, 14.26 for Gram-negative bacilli pneumonia. The negative likelihood ratio (LR-) was 0.20 for Pneumococcal pneumonia, 0.25 for Staphylococcal pneumonia, 0.22 for H. influenzae pneumonia, and 0.23 for Gram-negative bacilli pneumonia. Sputum Gram stain is a dependable diagnostic test for the early etiological diagnosis of bacterial CAP that helps in choosing orthological and appropriate initial antimicrobial therapy.

  18. Automated Interpretation of Blood Culture Gram Stains by Use of a Deep Convolutional Neural Network.

    Science.gov (United States)

    Smith, Kenneth P; Kang, Anthony D; Kirby, James E

    2018-03-01

    Microscopic interpretation of stained smears is one of the most operator-dependent and time-intensive activities in the clinical microbiology laboratory. Here, we investigated application of an automated image acquisition and convolutional neural network (CNN)-based approach for automated Gram stain classification. Using an automated microscopy platform, uncoverslipped slides were scanned with a 40× dry objective, generating images of sufficient resolution for interpretation. We collected 25,488 images from positive blood culture Gram stains prepared during routine clinical workup. These images were used to generate 100,213 crops containing Gram-positive cocci in clusters, Gram-positive cocci in chains/pairs, Gram-negative rods, or background (no cells). These categories were targeted for proof-of-concept development as they are associated with the majority of bloodstream infections. Our CNN model achieved a classification accuracy of 94.9% on a test set of image crops. Receiver operating characteristic (ROC) curve analysis indicated a robust ability to differentiate between categories with an area under the curve of >0.98 for each. After training and validation, we applied the classification algorithm to new images collected from 189 whole slides without human intervention. Sensitivity and specificity were 98.4% and 75.0% for Gram-positive cocci in chains and pairs, 93.2% and 97.2% for Gram-positive cocci in clusters, and 96.3% and 98.1% for Gram-negative rods. Taken together, our data support a proof of concept for a fully automated classification methodology for blood-culture Gram stains. Importantly, the algorithm was highly adept at identifying image crops with organisms and could be used to present prescreened, classified crops to technologists to accelerate smear review. This concept could potentially be extended to all Gram stain interpretive activities in the clinical laboratory. Copyright © 2018 American Society for Microbiology.

  19. Rapid and reliable identification of Gram-negative bacteria and Gram-positive cocci by deposition of bacteria harvested from blood cultures onto the MALDI-TOF plate.

    Science.gov (United States)

    Barnini, Simona; Ghelardi, Emilia; Brucculeri, Veronica; Morici, Paola; Lupetti, Antonella

    2015-06-18

    Rapid identification of the causative agent(s) of bloodstream infections using the matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) methodology can lead to increased empirical antimicrobial therapy appropriateness. Herein, we aimed at establishing an easier and simpler method, further referred to as the direct method, using bacteria harvested by serum separator tubes from positive blood cultures and placed onto the polished steel target plate for rapid identification by MALDI-TOF. The results by the direct method were compared with those obtained by MALDI-TOF on bacteria isolated on solid media. Identification of Gram-negative bacilli was 100 % concordant using the direct method or MALDI-TOF on isolated bacteria (96 % with score > 2.0). These two methods were 90 % concordant on Gram-positive cocci (32 % with score > 2.0). Identification by the SepsiTyper method of Gram-positive cocci gave concordant results with MALDI-TOF on isolated bacteria in 87 % of cases (37 % with score > 2.0). The direct method herein developed allows rapid identification (within 30 min) of Gram-negative bacteria and Gram-positive cocci from positive blood cultures and can be used to rapidly report reliable and accurate results, without requiring skilled personnel or the use of expensive kits.

  20. A potential benefit of albinism in Astyanax cavefish: downregulation of the oca2 gene increases tyrosine and catecholamine levels as an alternative to melanin synthesis.

    Science.gov (United States)

    Bilandžija, Helena; Ma, Li; Parkhurst, Amy; Jeffery, William R

    2013-01-01

    Albinism, the loss of melanin pigmentation, has evolved in a diverse variety of cave animals but the responsible evolutionary mechanisms are unknown. In Astyanax mexicanus, which has a pigmented surface dwelling form (surface fish) and several albino cave-dwelling forms (cavefish), albinism is caused by loss of function mutations in the oca2 gene, which operates during the first step of the melanin synthesis pathway. In addition to albinism, cavefish have evolved differences in behavior, including feeding and sleep, which are under the control of the catecholamine system. The catecholamine and melanin synthesis pathways diverge after beginning with the same substrate, L-tyrosine. Here we describe a novel relationship between the catecholamine and melanin synthesis pathways in Astyanax. Our results show significant increases in L-tyrosine, dopamine, and norepinephrine in pre-feeding larvae and adult brains of Pachón cavefish relative to surface fish. In addition, norepinephrine is elevated in cavefish adult kidneys, which contain the teleost homologs of catecholamine synthesizing adrenal cells. We further show that the oca2 gene is expressed during surface fish development but is downregulated in cavefish embryos. A key finding is that knockdown of oca2 expression in surface fish embryos delays the development of pigmented melanophores and simultaneously increases L-tyrosine and dopamine. We conclude that a potential evolutionary benefit of albinism in Astyanax cavefish may be to provide surplus L-tyrosine as a precursor for the elevated catecholamine synthesis pathway, which could be important for adaptation to the challenging cave environment.

  1. A potential benefit of albinism in Astyanax cavefish: downregulation of the oca2 gene increases tyrosine and catecholamine levels as an alternative to melanin synthesis.

    Directory of Open Access Journals (Sweden)

    Helena Bilandžija

    Full Text Available Albinism, the loss of melanin pigmentation, has evolved in a diverse variety of cave animals but the responsible evolutionary mechanisms are unknown. In Astyanax mexicanus, which has a pigmented surface dwelling form (surface fish and several albino cave-dwelling forms (cavefish, albinism is caused by loss of function mutations in the oca2 gene, which operates during the first step of the melanin synthesis pathway. In addition to albinism, cavefish have evolved differences in behavior, including feeding and sleep, which are under the control of the catecholamine system. The catecholamine and melanin synthesis pathways diverge after beginning with the same substrate, L-tyrosine. Here we describe a novel relationship between the catecholamine and melanin synthesis pathways in Astyanax. Our results show significant increases in L-tyrosine, dopamine, and norepinephrine in pre-feeding larvae and adult brains of Pachón cavefish relative to surface fish. In addition, norepinephrine is elevated in cavefish adult kidneys, which contain the teleost homologs of catecholamine synthesizing adrenal cells. We further show that the oca2 gene is expressed during surface fish development but is downregulated in cavefish embryos. A key finding is that knockdown of oca2 expression in surface fish embryos delays the development of pigmented melanophores and simultaneously increases L-tyrosine and dopamine. We conclude that a potential evolutionary benefit of albinism in Astyanax cavefish may be to provide surplus L-tyrosine as a precursor for the elevated catecholamine synthesis pathway, which could be important for adaptation to the challenging cave environment.

  2. EFFECT OF SILICATE ON GRAM STAINING AND VIABILITY OF PNEUMOCOCCI AND OTHER BACTERIA

    Science.gov (United States)

    MacLeod, Colin M.; Roe, Amy S.

    1956-01-01

    Application of silicate solutions to living or heat-killed pneumococci and to certain "viridans" streptococci causes their conversion from a Gram-positive to a Gram-negative state. The original staining properties can be restored by suspending the silicate-treated bacteria in alkaline solutions of various salts but not by simple washing in water. Living pneumococci and the strains of streptococci whose staining properties are similarly affected are killed when suspended in silicate solutions. In other Gram-positive species silicate causes conversion to Gram negativity but restoration to positivity occurs upon washing in water. In a third group of Gram-positive organisms silicate has no effect on the Gram reaction. The viability of organisms in these two groups is unaffected by silicate under the conditions employed. No effect on staining or viability of Gram-negative bacteria has been observed. The effects of silicate on staining and viability are inhibited by nutrient broth or whole serum but not by purified serum albumin. Lecithin, choline, and other substituted ammonium compounds also inhibit the effects of silicate on pneumococci. PMID:13306854

  3. Improving Gram stain proficiency in hospital and satellite laboratories that do not have microbiology.

    Science.gov (United States)

    Guarner, Jeannette; Street, Cassandra; Matlock, Margaret; Cole, Lisa; Brierre, Francoise

    2017-03-01

    Consolidation of laboratories has left many hospitals and satellite laboratories with minimal microbiologic testing. In many hospitals and satellite laboratories, Gram stains on primary specimens are still performed despite difficultly in maintaining proficiency. To maintain Gram stain proficiency at a community 450-bed hospital with an active emergency room we designed bimonthly challenges that require reporting Gram staining and morphology of different organisms. The challenges consist of five specimens prepared by the reference microbiology laboratory from cultures and primary specimens. Twenty to 23 medical laboratory scientists participate reading the challenges. Results from the challenges are discussed with each medical laboratory scientists. In addition, printed images from the challenges are presented at huddle to add microbiology knowledge. On the first three challenges, Gram staining was read correctly in 71%-77% of the time while morphology 53%-66%. In the last six challenges correct answers for Gram stain were 77%-99% while morphology 73%-96%. We observed statistically significant improvement when reading Gram stains by providing frequent challenges to medical laboratory scientists. The clinical importance of Gram stain results is emphasized during huddle presentations increasing knowledge and motivation to perform the test for patients.

  4. Resistance trends in gram-negative bacteria: surveillance results from two Mexican hospitals, 2005–2010

    Directory of Open Access Journals (Sweden)

    Morfin-Otero Rayo

    2012-06-01

    Full Text Available Abstract Background Hospital-acquired infections caused by multiresistant gram-negative bacteria are difficult to treat and cause high rates of morbidity and mortality. The analysis of antimicrobial resistance trends of gram-negative pathogens isolated from hospital-acquired infections is important for the development of antimicrobial stewardship programs. The information obtained from antimicrobial resistant programs from two hospitals from Mexico will be helpful in the selection of empiric therapy for hospital-acquired gram-negative infections. Findings Two thousand one hundred thirty two gram-negative bacteria collected between January 2005 and December 2010 from hospital-acquired infections occurring in two teaching hospitals in Mexico were evaluated. Escherichia coli was the most frequently isolated gram-negative bacteria, with >50% of strains resistant to ciprofloxacin and levofloxacin. Klebsiella spp. showed resistance rates similar to Escherichia coli for ceftazidime (33.1% vs 33.2%, but exhibited lower rates for levofloxacin (18.2% vs 56%. Of the samples collected for the third most common gram-negative bacteria, Pseudomonas aeruginosa, >12.8% were resistant to the carbapenems, imipenem and meropenem. The highest overall resistance was found in Acinetobacter spp. Enterobacter spp. showed high susceptibility to carbapenems. Conclusions E. coli was the most common nosocomial gram-negative bacilli isolated in this study and was found to have the second-highest resistance to fluoroquinolones (>57.9%, after Acinetobacter spp. 81.2%. This finding represents a disturbing development in a common nosocomial and community pathogen.

  5. Reconstitution of Protein Translation of Mycobacterium Reveals Functional Conservation and Divergence with the Gram-Negative Bacterium Escherichia coli.

    Directory of Open Access Journals (Sweden)

    Aashish Srivastava

    Full Text Available Protein translation is essential for all bacteria pathogens. It has also been a major focus of structural and functional studies and an important target of antibiotics. Here we report our attempts to biochemically reconstitute mycobacterial protein translation in vitro from purified components. This mycobacterial translation system consists of individually purified recombinant translation factors from Mycobacterium tuberculosis (M. tuberculosis, purified tRNAs and ribosomes from Mycobacterium smegmatis (M. smegmatis, and an aminoacyl-tRNA synthetase (AARS mixture from the cell-extract of M. smegmatis. We demonstrate that such mycobacterial translation system was efficient in in vitro protein synthesis, and enabled functional comparisons of translational components between the gram-positive Mycobacterium and the gram-negative E. coli. Although mycobacterial translation factors and ribosomes were highly compatible with their E. coli counterparts, M. smegmatis tRNAs were not properly charged by the E. coli AARSs to allow efficient translation of a reporter. In contrast, both E. coli and M. smegmatis tRNAs exhibited similar activity with the semi-purified M. smegmatis AARSs mixture for in vitro translation. We further demonstrated the use of both mycobacterial and E. coli translation systems as comparative in vitro assays for small-molecule antibiotics that target protein translation. While mycobacterial and E. coli translation were both inhibited at the same IC50 by the antibiotic spectinomycin, mycobacterial translation was preferentially inhibited by the antibiotic tetracycline, suggesting that there may be structural differences at the antibiotic binding sites between the ribosomes of Mycobacterium and E. coli. Our results illustrate an alternative approach for antibiotic discovery and functional studies of protein translation in mycobacteria and possibly other bacterial pathogens.

  6. Gram staining of protected pulmonary specimens in the early diagnosis of ventilator-associated pneumonia.

    Science.gov (United States)

    Mimoz, O; Karim, A; Mazoit, J X; Edouard, A; Leprince, S; Nordmann, P

    2000-11-01

    We evaluated prospectively the use of Gram staining of protected pulmonary specimens to allow the early diagnosis of ventilator-associated pneumonia (VAP), compared with the use of 60 bronchoscopic protected specimen brushes (PSB) and 126 blinded plugged telescopic catheters (PTC) obtained from 134 patients. Gram stains were from Cytospin slides; they were studied for the presence of microorganisms in 10 and 50 fields by two independent observers and classified according to their Gram stain morphology. Quantitative cultures were performed after serial dilution and plating on appropriate culture medium. A final diagnosis of VAP, based on a culture of > or = 10(3) c.f.u. ml-1, was established after 81 (44%) samplings. When 10 fields were analysed, a strong relationship was found between the presence of bacteria on Gram staining and the final diagnosis of VAP (for PSB and PTC respectively: sensitivity 74 and 81%, specificity 94 and 100%, positive predictive value 91 and 100%, negative predictive value 82 and 88%). The correlation was less when we compared the morphology of microorganisms observed on Gram staining with those of bacteria obtained from quantitative cultures (for PSB and PTC respectively: sensitivity 54 and 69%, specificity 86 and 89%, positive predictive value 72 and 78%, negative predictive value 74 and 84%). Increasing the number of fields read to 50 was associated with a slight decrease in specificity and positive predictive value of Gram staining, but with a small increase in its sensitivity and negative predictive value. The results obtained by the two observers were similar to each other for both numbers of fields analysed. Gram staining of protected pulmonary specimens performed on 10 fields predicted the presence of VAP and partially identified (using Gram stain morphology) the microorganisms growing at significant concentrations, and could help in the early choice of the treatment of VAP. Increasing the number of fields read or having the Gram

  7. Multiplex identification of sepsis-causing Gram-negative pathogens from the plasma of infected blood.

    Science.gov (United States)

    Chung, Boram; Park, Chulmin; Cho, Sung-Yeon; Shin, Juyoun; Shin, Sun; Yim, Seon-Hee; Lee, Dong-Gun; Chung, Yeun-Jung

    2018-02-01

    Early and accurate detection of bacterial pathogens in the blood is the most crucial step for sepsis management. Gram-negative bacteria are the most common organisms causing severe sepsis and responsible for high morbidity and mortality. We aimed to develop a method for rapid multiplex identification of clinically important Gram-negative pathogens and also validated whether our system can identify Gram-negative pathogens with the cell-free plasm DNA from infected blood. We designed five MLPA probe sets targeting the genes specific to major Gram-negative pathogens (uidA and lacY for E. coli, ompA for A. baumannii, phoE for K. pneumoniae, and ecfX for P. aeruginosa) and one set targeting the CTX-M group 1 to identify the ESBL producing Gram-negative pathogens. All six target-specific peaks were clearly separated without any non-specific peaks in a multiplex reaction condition. The minimum detection limit was 100 fg of pathogen DNA. When we tested 28 Gram-negative clinical isolates, all of them were successfully identified without any non-specific peaks. To evaluate the clinical applicability, we tested seven blood samples from febrile patients. Three blood culture positive cases showed E. coli specific peaks, while no peak was detected in the other four culture negative samples. This technology can be useful for detection of major sepsis-causing, drug-resistant Gram-negative pathogens and also the major ESBL producing Gram-negatives from the blood of sepsis patients in a clinical setting. This system can help early initiation of effective antimicrobial treatment against Gram-negative pathogens for sepsis patients, which is very crucial for better treatment outcomes. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  8. Extruded black gram flour: Partial substitute for improving quality characteristics of Indian traditional snack

    Directory of Open Access Journals (Sweden)

    Laxmi Ananthanarayan

    2018-03-01

    Full Text Available Background: During extrusion of black gram flour, formation of amylose-lipid complexes lowers down the gelatinization enthalpy of extrudates, and the partially gelatinized black gram starch leads to lowering down the water-holding capacity and alters functional properties resulting in changing quality attributes of the end product on frying/microwaving/roasting. Methods: Attempts have been made to improve the quality of an Indian traditional snack (e.g., papad by incorporating extruded black gram flour as partial substitute for raw (unextruded black gram flour. In present work, overall quality improvement was achieved by analyzing prefrying and postfrying characteristics (diameter, moisture content, expansion ratio, oil uptake, texture, and color of papad and physical properties (color and viscosity of fried oil. Results: Four different papad samples were prepared (control papads without addition of papadkhar, papads with use of 3% papadkhar, papads with incorporation of extruded black gram flour at 25% concentration, papads with incorporation of extruded black gram flour at 50% concentration along with 1% papadkhar and analyzed along standard market sample. Incorporation of extruded black gram flour in papad resulted in greater expansion with less oil uptake in fried papad. Further addition of extruded black gram flour permitted the use of lower concentration of papadkhar. After frying, the quality of oil was characterized after numerous frying cycles. Conclusion: Oil used for frying of papads containing highest concentration of papadkhar was effective only up to two frying cycles, after which color and viscosity increased significantly, adversely affecting the quality of fried oil. Keywords: Black gram flour, Extrusion, Prefrying and postfrying characteristics of papad, Quality of fried oil

  9. Organic synthesis

    Energy Technology Data Exchange (ETDEWEB)

    Thomas, S.E.

    1991-01-01

    This paper reports on reactions of organoboranes. Organoboron routes to unsaturated hydrocarbons. Boronic ester homologation. Properties of organosilicon compounds. Alkene synthesis (Peterson olefination). Allylsilanes and acylsilanes.

  10. Clinical utility of an automated instrument for gram staining single slides.

    Science.gov (United States)

    Baron, Ellen Jo; Mix, Samantha; Moradi, Wais

    2010-06-01

    Gram stains of 87 different clinical samples were prepared by the laboratory's conventional methods (automated or manual) and by a new single-slide-type automated staining instrument, GG&B AGS-1000. Gram stains from either heat- or methanol-fixed slides stained with the new instrument were easy to interpret, and results were essentially the same as those from the methanol-fixed slides prepared as a part of the routine workflow. This instrument is well suited to a rapid-response laboratory where Gram stain requests are commonly received on a stat basis.

  11. Clinical Utility of an Automated Instrument for Gram Staining Single Slides ▿

    Science.gov (United States)

    Baron, Ellen Jo; Mix, Samantha; Moradi, Wais

    2010-01-01

    Gram stains of 87 different clinical samples were prepared by the laboratory's conventional methods (automated or manual) and by a new single-slide-type automated staining instrument, GG&B AGS-1000. Gram stains from either heat- or methanol-fixed slides stained with the new instrument were easy to interpret, and results were essentially the same as those from the methanol-fixed slides prepared as a part of the routine workflow. This instrument is well suited to a rapid-response laboratory where Gram stain requests are commonly received on a stat basis. PMID:20410348

  12. Effect of gamma radiation on physico-chemical characteristics of red gram (Cajanus cajan) starch

    International Nuclear Information System (INIS)

    Nene, S.P.; Vakil, U.K.; Sreenivasan, A.

    1975-01-01

    Total reducing and nonreducing sugars in red gram (Cajanus cajan) are not affected by radiation treatment (1 Mrad). Oligosaccharides, reported as flatulence factors in legumes, namely stachyose and raffinose, are slightly decreased on cooking the irradiated samples. Irradiated and cooked red gram starch is more susceptible to alpha-amylase action than the unirradiated sample. Rheological properties of red gram starch, such as gelatinization viscosity, swelling power and solubility improve on irradiation resulting in a final cooked product with better textural properties. (U.S.)

  13. Mining for constructions in texts using N-gram and network analysis

    DEFF Research Database (Denmark)

    Shibuya, Yoshikata; Jensen, Kim Ebensgaard

    2015-01-01

    N-gram analysis to Lewis Carroll's novel Alice's Adventures in Wonderland and Mark Twain's novelThe Adventures of Huckleberry Finn and extrapolate a number of likely constructional phenomena from recurring N-gram patterns in the two texts. In addition to simple N-gram analysis, the following....... The main premise is that, if constructions are functional units, then configurations of words that tend to recur together in discourse are likely to have some sort of function that speakers utilize in discourse. Writers of fiction, for instance, may use constructions in characterizations, mind-styles, text...

  14. Gramáticas de grafos y su aplicación en inferencia gramatical

    OpenAIRE

    Jeltsch F., Eric

    1997-01-01

    En este trabajo se presentan las gramáticas de grafos en particular un tipo de gramáticas de grafo las cuales tienen un contexto libre en el mecanismo de derivación al igual que las gramáticas de Chomsky proporcionando de esta manera un simple mecanismo para generar lenguajes de grafos. Para hacer transparente el proceso de generación de grafos se introducen los grafos decorados que son grafos equipados con una información adicional llamada hiperlíneal las cuales al ser reemplazadas en forma ...

  15. The TFPI-2 derived peptide EDC34 improves outcome of gram-negative sepsis.

    Directory of Open Access Journals (Sweden)

    Praveen Papareddy

    Full Text Available Sepsis is characterized by a dysregulated host-pathogen response, leading to high cytokine levels, excessive coagulation and failure to eradicate invasive bacteria. Novel therapeutic strategies that address crucial pathogenetic steps during infection are urgently needed. Here, we describe novel bioactive roles and therapeutic anti-infective potential of the peptide EDC34, derived from the C-terminus of tissue factor pathway inhibitor-2 (TFPI-2. This peptide exerted direct bactericidal effects and boosted activation of the classical complement pathway including formation of antimicrobial C3a, but inhibited bacteria-induced activation of the contact system. Correspondingly, in mouse models of severe Escherichia coli and Pseudomonas aeruginosa infection, treatment with EDC34 reduced bacterial levels and lung damage. In combination with the antibiotic ceftazidime, the peptide significantly prolonged survival and reduced mortality in mice. The peptide's boosting effect on bacterial clearance paired with its inhibiting effect on excessive coagulation makes it a promising therapeutic candidate for invasive Gram-negative infections.

  16. Performing Gram stain directly on catheter tips: assessment of the quality of the observation process.

    Science.gov (United States)

    Guembe, M; Pérez-Granda, M J; Rivera, M L; Martín-Rabadán, P; Bouza, E

    2015-06-01

    A previous study performed in our institution showed that catheter tip (CT) staining by combining acridine orange and Gram stain (GS) before culture anticipated catheter colonization with exhaustive and careful observation by a highly trained technician. Our objective was to assess the validity values of GS without acridine orange on an external smear of CT for predicting catheter colonization and catheter-related bloodstream infection (C-RBSI). We compared different periods of observation and the results of two technicians with different levels of professional experience. Over a 5-month period, the roll-plate technique was preceded by direct GS of all CTs sent to the microbiology laboratory. The reading was taken at ×100 by two observers with different skill levels. Each observer performed a routine examination (3 min along three longitudinal lines) and an exhaustive examination (5 min along five longitudinal lines). The presence of at least one cell was considered positive. All slides were read before culture results were known. We included a total of 271 CTs from 209 patients. The prevalence of catheter colonization and C-RBSI was 16.2 % and 5.1 %, respectively. Routine and exhaustive examinations revealed only 29.5 % and 40.9 % of colonized catheters, respectively (p staining is performed exhaustively. However, the decision to implement this approach in daily routine will depend on the prevalence rate of catheter colonization at each institution.

  17. The modern synthesis, Ronald Fisher and creationism.

    Science.gov (United States)

    Leigh

    1999-12-01

    The 'modern evolutionary synthesis' convinced most biologists that natural selection was the only directive influence on adaptive evolution. Today, however, dissatisfaction with the synthesis is widespread, and creationists and antidarwinians are multiplying. The central problem with the synthesis is its failure to show (or to provide distinct signs) that natural selection of random mutations could account for observed levels of adaptation.

  18. Physico-Chemical-Managed Killing of Penicillin-Resistant Static and Growing Gram-Positive and Gram-Negative Vegetative Bacteria

    Science.gov (United States)

    Richmond, Robert Chaffee (Inventor); Schramm, Jr., Harry F. (Inventor); Defalco, Francis G. (Inventor); Farris, III, Alex F. (Inventor)

    2012-01-01

    Systems and methods for the use of compounds from the Hofmeister series coupled with specific pH and temperature to provide rapid physico-chemical-managed killing of penicillin-resistant static and growing Gram-positive and Gram-negative vegetative bacteria. The systems and methods represent the more general physico-chemical enhancement of susceptibility for a wide range of pathological macromolecular targets to clinical management by establishing the reactivity of those targets to topically applied drugs or anti-toxins.

  19. Cardiolipin, a major phospholipid of gram-positive bacteria that is not readily extractable

    NARCIS (Netherlands)

    Filgueiras, M.H.; Kamp, J.A.F. op den

    1980-01-01

    Extraction of phospholipids from stationary phase grown cells of the Gram+ bacteria, Bacillus megaterium, Bacillus subtilis, Bacillus cereus and Micrococcus lysodeikticus was found to be incomplete with various commonly used extraction procedures. Phosphatidylglycerol and phosphatidyl-ethanolamine

  20. One Small Step for the Gram Stain, One Giant Leap for Clinical Microbiology.

    Science.gov (United States)

    Thomson, Richard B

    2016-06-01

    The Gram stain is one of the most commonly performed tests in the clinical microbiology laboratory, yet it is poorly controlled and lacks standardization. It was once the best rapid test in microbiology, but it is no longer trusted by many clinicians. The publication by Samuel et al. (J. Clin. Microbiol. 54:1442-1447, 2016, http://dx.doi.org/10.1128/JCM.03066-15) is a start for those who want to evaluate and improve Gram stain performance. In an age of emerging rapid molecular results, is the Gram stain still relevant? How should clinical microbiologists respond to the call to reduce Gram stain error rates? Copyright © 2016, American Society for Microbiology. All Rights Reserved.

  1. Septicemia caused by the gram-negative bacterium CDC IV c-2 in an immunocompromised human.

    OpenAIRE

    Dan, M; Berger, S A; Aderka, D; Levo, Y

    1986-01-01

    A 37-year-old man with plasma cell leukemia developed nonfatal septicemia caused by the gram-negative bacterium CDC IV c-2. Recovery followed appropriate treatment with antibiotics. The biochemical features of this organism are reviewed.

  2. European surveillance study on antimicrobial susceptibility of Gram-positive anaerobic cocci

    DEFF Research Database (Denmark)

    Brazier, J; Chmelar, D; Dubreuil, L

    2008-01-01

    Gram-positive anaerobic cocci (GPAC) are a heterogeneous group of microorganisms frequently isolated from local and systemic infections. In this study, the antimicrobial susceptibilities of clinical strains isolated in 10 European countries were investigated. After identification of 299 GPAC...

  3. Breeding high yielding varieties of pigeon pea, mungbean and black gram using induced mutations

    International Nuclear Information System (INIS)

    Pawar, S.E.; Wanjari, K.B.

    1994-01-01

    The present communication emphasis the developing of high yielding varieties of pigeon pea, mungbean and black gram using induced mutation with disease resistance in these crops. This would help in stabilisation of the higher yield potential

  4. Cystic neutrophilic granulomatous mastitis: an underappreciated pattern strongly associated with gram-positive bacilli.

    Science.gov (United States)

    Renshaw, Andrew A; Derhagopian, Robert P; Gould, Edwin W

    2011-09-01

    Although granulomatous lobular mastitis is associated with gram-positive bacilli such as Corynebacterium, this association is not well known. We report 3 cases of mastitis caused by gram-positive bacilli. All 3 abscesses were suppurative with distinct enlarged cystic spaces in which rare gram-positive bacilli were identified. Two cases were also granulomatous. Cultures in all 3 cases were negative. All 3 patients recovered after biopsy and tetracycline-based therapy. Infection in the breast by gram-positive bacilli is associated with a distinct histologic pattern, including cystic spaces in the setting of neutrophilic/granulomatous inflammation that can be recognized and should prompt careful search for the organism within enlarged vacuoles.

  5. Rapid, highly sensitive detection of Gram-negative bacteria with lipopolysaccharide based disposable aptasensor.

    Science.gov (United States)

    Zhang, Jian; Oueslati, Rania; Cheng, Cheng; Zhao, Ling; Chen, Jiangang; Almeida, Raul; Wu, Jayne

    2018-07-30

    Gram-negative bacteria are one of the most common microorganisms in the environment. Their differential detection and recognition from Gram-positive bacteria has been attracting much attention over the years. Using Escherichia coli (E. coli) as a model, we demonstrated on-site detection of Gram-negative bacteria by an AC electrokinetics-based capacitive sensing method using commercial microelectrodes functionalized with an aptamer specific to lipopolysaccharides. Dielectrophoresis effect was utilized to enrich viable bacteria to the microelectrodes rapidly, achieving a detection limit of 10 2 cells/mL within a 30 s' response time. The sensor showed a negligible response to Staphylococcus aureus (S. aureus), a Gram-positive species. The developed sensor showed significant advantages in sensitivity, selectivity, cost, operation simplicity, and response time. Therefore, this sensing method has shown great application potential for environmental monitoring, food safety, and real-time diagnosis. Copyright © 2018 Elsevier B.V. All rights reserved.

  6. Incidence of carbapenem-resistant gram negatives in Italian transplant recipients: a nationwide surveillance study.

    Science.gov (United States)

    Lanini, Simone; Costa, Alessandro Nanni; Puro, Vincenzo; Procaccio, Francesco; Grossi, Paolo Antonio; Vespasiano, Francesca; Ricci, Andrea; Vesconi, Sergio; Ison, Michael G; Carmeli, Yehuda; Ippolito, Giuseppe

    2015-01-01

    Bacterial infections remain a challenge to solid organ transplantation. Due to the alarming spread of carbapenem-resistant gram negative bacteria, these organisms have been frequently recognized as cause of severe infections in solid organ transplant recipients. Between 15 May and 30 September 2012 we enrolled 887 solid organ transplant recipients in Italy with the aim to describe the epidemiology of gram negative bacteria spreading, to explore potential risk factors and to assess the effect of early isolation of gram negative bacteria on recipients' mortality during the first 90 days after transplantation. During the study period 185 clinical isolates of gram negative bacteria were reported, for an incidence of 2.39 per 1000 recipient-days. Positive cultures for gram negative bacteria occurred early after transplantation (median time 26 days; incidence rate 4.33, 1.67 and 1.14 per 1,000 recipient-days in the first, second and third month after SOT, respectively). Forty-nine of these clinical isolates were due to carbapenem-resistant gram negative bacteria (26.5%; incidence 0.63 per 1000 recipient-days). Carbapenems resistance was particularly frequent among Klebsiella spp. isolates (49.1%). Recipients with longer hospital stay and those who received either heart or lung graft were at the highest risk of testing positive for any gram negative bacteria. Moreover recipients with longer hospital stay, lung recipients and those admitted to hospital for more than 48h before transplantation had the highest probability to have culture(s) positive for carbapenem-resistant gram negative bacteria. Forty-four organ recipients died (0.57 per 1000 recipient-days) during the study period. Recipients with at least one positive culture for carbapenem-resistant gram negative bacteria had a 10.23-fold higher mortality rate than those who did not. The isolation of gram-negative bacteria is most frequent among recipient with hospital stays >48 hours prior to transplant and in those

  7. Incidence of carbapenem-resistant gram negatives in Italian transplant recipients: a nationwide surveillance study.

    Directory of Open Access Journals (Sweden)

    Simone Lanini

    Full Text Available Bacterial infections remain a challenge to solid organ transplantation. Due to the alarming spread of carbapenem-resistant gram negative bacteria, these organisms have been frequently recognized as cause of severe infections in solid organ transplant recipients.Between 15 May and 30 September 2012 we enrolled 887 solid organ transplant recipients in Italy with the aim to describe the epidemiology of gram negative bacteria spreading, to explore potential risk factors and to assess the effect of early isolation of gram negative bacteria on recipients' mortality during the first 90 days after transplantation. During the study period 185 clinical isolates of gram negative bacteria were reported, for an incidence of 2.39 per 1000 recipient-days. Positive cultures for gram negative bacteria occurred early after transplantation (median time 26 days; incidence rate 4.33, 1.67 and 1.14 per 1,000 recipient-days in the first, second and third month after SOT, respectively. Forty-nine of these clinical isolates were due to carbapenem-resistant gram negative bacteria (26.5%; incidence 0.63 per 1000 recipient-days. Carbapenems resistance was particularly frequent among Klebsiella spp. isolates (49.1%. Recipients with longer hospital stay and those who received either heart or lung graft were at the highest risk of testing positive for any gram negative bacteria. Moreover recipients with longer hospital stay, lung recipients and those admitted to hospital for more than 48h before transplantation had the highest probability to have culture(s positive for carbapenem-resistant gram negative bacteria. Forty-four organ recipients died (0.57 per 1000 recipient-days during the study period. Recipients with at least one positive culture for carbapenem-resistant gram negative bacteria had a 10.23-fold higher mortality rate than those who did not.The isolation of gram-negative bacteria is most frequent among recipient with hospital stays >48 hours prior to transplant

  8. A flow-cytometric gram-staining technique for milk-associated bacteria.

    Science.gov (United States)

    Holm, Claus; Jespersen, Lene

    2003-05-01

    A Gram-staining technique combining staining with two fluorescent stains, Oregon Green-conjugated wheat germ agglutinin (WGA) and hexidium iodide (HI) followed by flow-cytometric detection is described. WGA stains gram-positive bacteria while HI binds to the DNA of all bacteria after permeabilization by EDTA and incubation at 50 degrees C for 15 min. For WGA to bind to gram-positive bacteria, a 3 M potassium chloride solution was found to give the highest fluorescence intensity. A total of 12 strains representing some of the predominant bacterial species in bulk tank milk and mixtures of these were stained and analyzed by flow cytometry. Overall, the staining method showed a clear differentiation between gram-positive and gram-negative bacterial populations. For stationary-stage cultures of seven gram-positive bacteria and five gram-negative bacteria, an average of 99% of the cells were correctly interpreted. The method was only slightly influenced by the growth phase of the bacteria or conditions such as freezing at -18 degrees C for 24 h. For any of these conditions, an average of at least 95% of the cells were correctly interpreted. When stationary-stage cultures were stored at 5 degrees C for 14 days, an average of 86% of the cells were correctly interpreted. The Gram-staining technique was applied to the flow cytometry analysis of bulk tank milk inoculated with Staphylococcus aureus and Escherichia coli. These results demonstrate that the technique is suitable for analyzing milk samples without precultivation.

  9. Exact closed-form expression for the inverse moments of one-sided correlated Gram matrices

    KAUST Repository

    Elkhalil, Khalil

    2016-08-15

    In this paper, we derive a closed-form expression for the inverse moments of one sided-correlated random Gram matrices. Such a question is mainly motivated by applications in signal processing and wireless communications for which evaluating this quantity is a question of major interest. This is for instance the case of the best linear unbiased estimator, in which the average estimation error corresponds to the first inverse moment of a random Gram matrix.

  10. Exact closed-form expression for the inverse moments of one-sided correlated Gram matrices

    KAUST Repository

    Elkhalil, Khalil; Kammoun, Abla; Al-Naffouri, Tareq Y.; Alouini, Mohamed-Slim

    2016-01-01

    In this paper, we derive a closed-form expression for the inverse moments of one sided-correlated random Gram matrices. Such a question is mainly motivated by applications in signal processing and wireless communications for which evaluating this quantity is a question of major interest. This is for instance the case of the best linear unbiased estimator, in which the average estimation error corresponds to the first inverse moment of a random Gram matrix.

  11. A classification system for plasmids from Enterococci and other Gram-positive bacteria

    DEFF Research Database (Denmark)

    Jensen, Lars Bogø; Garcia-Migura, Lourdes; Valenzuela, Antonio Jesus Sanchez

    2010-01-01

    A classification system for plasmids isolated from enterococci and other Gram-positive bacteria was developed based on 111 published plasmid sequences from enterococci and other Gram-positive bacteria; mostly staphylococci. Based on PCR amplification of conserved areas of the replication initiating....... Furthermore, conjugation experiments were performed obtaining 30 transconjugants when selecting for antimicrobial resistance. Among them 19 gave no positive amplicons indicating presence of rep-families not tested for in this experimental setup....

  12. Gram-Positive Uropathogens, Polymicrobial Urinary Tract Infection, and the Emerging Microbiota of the Urinary Tract.

    Science.gov (United States)

    Kline, Kimberly A; Lewis, Amanda L

    2016-04-01

    Gram-positive bacteria are a common cause of urinary-tract infection (UTI), particularly among individuals who are elderly, pregnant, or who have other risk factors for UTI. Here we review the epidemiology, virulence mechanisms, and host response to the most frequently isolated Gram-positive uropathogens: Staphylococcus saprophyticus, Enterococcus faecalis, and Streptococcus agalactiae. We also review several emerging, rare, misclassified, and otherwise underreported Gram-positive pathogens of the urinary tract including Aerococcus, Corynebacterium, Actinobaculum, and Gardnerella. The literature strongly suggests that urologic diseases involving Gram-positive bacteria may be easily overlooked due to limited culture-based assays typically utilized for urine in hospital microbiology laboratories. Some UTIs are polymicrobial in nature, often involving one or more Gram-positive bacteria. We herein review the risk factors and recent evidence for mechanisms of bacterial synergy in experimental models of polymicrobial UTI. Recent experimental data has demonstrated that, despite being cleared quickly from the bladder, some Gram-positive bacteria can impact pathogenic outcomes of co-infecting organisms. When taken together, the available evidence argues that Gram-positive bacteria are important uropathogens in their own right, but that some can be easily overlooked because they are missed by routine diagnostic methods. Finally, a growing body of evidence demonstrates that a surprising variety of fastidious Gram-positive bacteria may either reside in or be regularly exposed to the urinary tract and further suggests that their presence is widespread among women, as well as men. Experimental studies in this area are needed; however, there is a growing appreciation that the composition of bacteria found in the bladder could be a potentially important determinant in urologic disease, including susceptibility to UTI.

  13. Gram-negative and -positive bacteria differentiation in blood culture samples by headspace volatile compound analysis.

    Science.gov (United States)

    Dolch, Michael E; Janitza, Silke; Boulesteix, Anne-Laure; Graßmann-Lichtenauer, Carola; Praun, Siegfried; Denzer, Wolfgang; Schelling, Gustav; Schubert, Sören

    2016-12-01

    Identification of microorganisms in positive blood cultures still relies on standard techniques such as Gram staining followed by culturing with definite microorganism identification. Alternatively, matrix-assisted laser desorption/ionization time-of-flight mass spectrometry or the analysis of headspace volatile compound (VC) composition produced by cultures can help to differentiate between microorganisms under experimental conditions. This study assessed the efficacy of volatile compound based microorganism differentiation into Gram-negatives and -positives in unselected positive blood culture samples from patients. Headspace gas samples of positive blood culture samples were transferred to sterilized, sealed, and evacuated 20 ml glass vials and stored at -30 °C until batch analysis. Headspace gas VC content analysis was carried out via an auto sampler connected to an ion-molecule reaction mass spectrometer (IMR-MS). Measurements covered a mass range from 16 to 135 u including CO2, H2, N2, and O2. Prediction rules for microorganism identification based on VC composition were derived using a training data set and evaluated using a validation data set within a random split validation procedure. One-hundred-fifty-two aerobic samples growing 27 Gram-negatives, 106 Gram-positives, and 19 fungi and 130 anaerobic samples growing 37 Gram-negatives, 91 Gram-positives, and two fungi were analysed. In anaerobic samples, ten discriminators were identified by the random forest method allowing for bacteria differentiation into Gram-negative and -positive (error rate: 16.7 % in validation data set). For aerobic samples the error rate was not better than random. In anaerobic blood culture samples of patients IMR-MS based headspace VC composition analysis facilitates bacteria differentiation into Gram-negative and -positive.

  14. Green-fuel-mediated synthesis of self-assembled NiO nano-sticks for dual applications—photocatalytic activity on Rose Bengal dye and antimicrobial action on bacterial strains

    Science.gov (United States)

    Iyyappa Rajan, P.; Vijaya, J. Judith; Jesudoss, S. K.; Kaviyarasu, K.; Kennedy, L. John; Jothiramalingam, R.; Al-Lohedan, Hamad A.; Vaali-Mohammed, Mansoor-Ali

    2017-08-01

    With aim of promoting the employability of green fuels in the synthesis of nano-scaled materials with new kinds of morphologies for multiple applications, successful synthesis of self-assembled NiO nano-sticks was achieved through a 100% green-fuel-mediated hot-plate combustion reaction. The synthesized NiO nano-sticks show excellent photocatalytic activity on Rose Bengal dye and superior antibacterial potential towards both Gram-positive and Gram-negative bacteria.

  15. Sistema de tareas para la enseñanza combinada de la gramática comunicativa y la gramática tradicional de lengua inglesa

    Directory of Open Access Journals (Sweden)

    Nancy del Carmen Jiménez Figueredo

    2015-03-01

    Full Text Available Se realizó el diseño de un sistema de tareas para la enseñanza combinada de la gramática comunicativa y la gramática tradicional de lengua inglesa, con metodología cuali-cuantitativa, en la Facultad de Ciencias Médicas “Zoilo Marinello Vidaurreta” de la Universidad de Ciencias Médicas de Las Tunas, durante el período comprendido entre septiembre de 2011 y julio de 2014. El objetivo estuvo direccionado a perfeccionar la corrección lingüística en el proceso de enseñanza-aprendizaje del idioma Inglés. La realización del diseño contó con: una revisión bibliográfica de los principales enfoques utilizados en la enseñanza-aprendizaje del Inglés; la revisión documental, que permitió determinar las insuficiencias lingüísticas y la necesidad de combinar la gramática comunicativa con la gramática tradicional, en los estudiantes del cuarto año de la carrera de Estomatología; el intercambio con profesionales con más de quince años de experiencia, para obtener información acerca del proceso de enseñanza-aprendizaje de la gramática; y la aplicación de una valoración equivalente al juicio de expertos, método de agregados individuales, para valorar la propuesta. Los principales resultados fueron: la caracterización de las insuficiencias provocadas por la absolutización del enfoque comunicativo en la enseñanza de la gramática de la lengua inglesa y el diseño de un sistema de tareas para el proceso de enseñanza-aprendizaje de la gramática inglesa en estos estudiantes

  16. Comparison of E-test with other conventional susceptibility testing methods for ciprofloxacin and gentamicin against gram negative enteric bacilli.

    Science.gov (United States)

    Ogbolu, D O; Terry-Alli, O A; Daini, O A; Olabiyi, F A; Igharo, E A

    2012-06-01

    Increasing antibiotic resistance in Gram negative bacteria has led to the need for a faster and reliable method for determining antimicrobial susceptibility testing. In a resource poor setting like ours, it's also important to look for methods that will be clinically and economically beneficial to the patient. This study was aimed at evaluating the Epsilometer test (E-test) and conventional methods for determining antimicrobial susceptibility of isolates of Gram-negative enteric bacteria to ciprofloxacin and gentamicin. Disc diffusion, E-test, broth dilution and agar dilution methods were performed on 54 bacterial isolates. Using the E-test, 88.9% of bacterial isolates were resistant to ciprofloxacin, 92.6% were resistant using broth microdilution, 96.3% were resistant using agar dilution and 72.2% were resistant using disc diffusion. Minimum inhibitory concentration (MIC50) of isolates for gentamicin showed significant difference for all the techniques (p 0.05). Both E-test and broth dilution methods showed high levels of agreement (p > 0.05), there were low levels of agreement between E-test and agar dilution method (p < 0.05), especially at MIC50. The E-test can therefore be considered a reliable method to determine antimicrobial susceptibility testing and it gives results which are at least as accurate as those obtained by the broth dilution method.

  17. [Comparison of the quick Gram stain method to the B&M modified and favor methods].

    Science.gov (United States)

    Osawa, Kayo; Kataoka, Nobumasa; Maruo, Toshio

    2011-01-01

    The Gram stain is an established method for bacterial identification, but the time needed to carry out this stain is 2-3 min. We attempted to shorten this time and stained a total of 70 clinical specimens isolated from using the Bartholomew & Mittwer (B&M) modified or Favor methods with a 3 s duration for washing and staining steps. Results were plotted and analyzed using a Hue Saturation Intensity (HSI) model. The range based on a plot of the two methods with the HSI model was presented as a reference interval. Our results indicated that 100% (35/35) of strains were Gram positive and 97.1% (34/35) were Gram negative for the quick B&M modified method. In the quick Favor method, 80.0% (28/35) were Gram positive and 68.6% (24/35) of strains were Gram negative. We propose that the quick B&M modified method is equivalent to the standard Gram staining method and is superior to the quick Favor method.

  18. Breaking barriers: expansion of the use of endolysins as novel antibacterials against Gram-negative bacteria.

    Science.gov (United States)

    Briers, Yves; Lavigne, Rob

    2015-01-01

    The emergence and spread of antibiotic-resistant bacteria drives the search for novel classes of antibiotics to replenish our armamentarium against bacterial infections. This is particularly critical for Gram-negative pathogens, which are intrinsically resistant to many existing classes of antibiotics due to the presence of a protective outer membrane. In addition, the antibiotics development pipeline is mainly oriented to Gram-positive pathogens such as methicillin-resistant Staphylococcus aureus. A promising novel class of antibacterials is endolysins. These enzymes encoded by bacterial viruses hydrolyze the peptidoglycan layer with high efficiency, resulting in abrupt osmotic lysis and cell death. Their potential as novel antibacterials to treat Gram-positive bacteria has been extensively demonstrated; however, the Gram-negative outer membrane has presented a formidable barrier for the use of endolysins against Gram-negatives until recently. This review reports on the most recent advances in the development of endolysins to kill Gram-negative species with a special focus on endolysin-engineered Artilysins(®).

  19. GPU Based N-Gram String Matching Algorithm with Score Table Approach for String Searching in Many Documents

    Science.gov (United States)

    Srinivasa, K. G.; Shree Devi, B. N.

    2017-10-01

    String searching in documents has become a tedious task with the evolution of Big Data. Generation of large data sets demand for a high performance search algorithm in areas such as text mining, information retrieval and many others. The popularity of GPU's for general purpose computing has been increasing for various applications. Therefore it is of great interest to exploit the thread feature of a GPU to provide a high performance search algorithm. This paper proposes an optimized new approach to N-gram model for string search in a number of lengthy documents and its GPU implementation. The algorithm exploits GPGPUs for searching strings in many documents employing character level N-gram matching with parallel Score Table approach and search using CUDA API. The new approach of Score table used for frequency storage of N-grams in a document, makes the search independent of the document's length and allows faster access to the frequency values, thus decreasing the search complexity. The extensive thread feature in a GPU has been exploited to enable parallel pre-processing of trigrams in a document for Score Table creation and parallel search in huge number of documents, thus speeding up the whole search process even for a large pattern size. Experiments were carried out for many documents of varied length and search strings from the standard Lorem Ipsum text on NVIDIA's GeForce GT 540M GPU with 96 cores. Results prove that the parallel approach for Score Table creation and searching gives a good speed up than the same approach executed serially.

  20. Multicenter Evaluation of the Bruker MALDI Biotyper CA System for the Identification of Clinical Aerobic Gram-Negative Bacterial Isolates.

    Directory of Open Access Journals (Sweden)

    Matthew L Faron

    Full Text Available The prompt and accurate identification of bacterial pathogens is fundamental to patient health and outcome. Recent advances in matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS have revolutionized bacterial identification in the clinical laboratory, but uniform incorporation of this technology in the U.S. market has been delayed by a lack of FDA-cleared systems. In this study, we conducted a multicenter evaluation of the MALDI Biotyper CA (MBT-CA System (Bruker Daltonics Inc, Billerica, MA for the identification of aerobic gram-negative bacteria as part of a 510(k submission to the FDA. A total of 2,263 aerobic gram negative bacterial isolates were tested representing 23 genera and 61 species. Isolates were collected from various clinical sources and results obtained from the MBT-CA System were compared to DNA sequencing and/or biochemical testing. Isolates that failed to report as a "high confidence species ID" [log(score ≥2.00] were re-tested using an extraction method. The MBT-CA System identified 96.8% and 3.1% of isolates with either a "high confidence" or a "low confidence" [log(score value between 1.70 and <2.00] species ID, respectively. Two isolates did not produce acceptable confidence scores after extraction. The MBT-CA System correctly identified 99.8% (2,258/2,263 to genus and 98.2% (2,222/2,263 to species level. These data demonstrate that the MBT-CA System provides accurate results for the identification of aerobic gram-negative bacteria.

  1. Multicenter Evaluation of the Bruker MALDI Biotyper CA System for the Identification of Clinical Aerobic Gram-Negative Bacterial Isolates.

    Science.gov (United States)

    Faron, Matthew L; Buchan, Blake W; Hyke, Josh; Madisen, Neil; Lillie, Jennifer L; Granato, Paul A; Wilson, Deborah A; Procop, Gary W; Novak-Weekley, Susan; Marlowe, Elizabeth; Cumpio, Joven; Griego-Fullbright, Christen; Kindig, Sandra; Timm, Karen; Young, Stephen; Ledeboer, Nathan A

    2015-01-01

    The prompt and accurate identification of bacterial pathogens is fundamental to patient health and outcome. Recent advances in matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) have revolutionized bacterial identification in the clinical laboratory, but uniform incorporation of this technology in the U.S. market has been delayed by a lack of FDA-cleared systems. In this study, we conducted a multicenter evaluation of the MALDI Biotyper CA (MBT-CA) System (Bruker Daltonics Inc, Billerica, MA) for the identification of aerobic gram-negative bacteria as part of a 510(k) submission to the FDA. A total of 2,263 aerobic gram negative bacterial isolates were tested representing 23 genera and 61 species. Isolates were collected from various clinical sources and results obtained from the MBT-CA System were compared to DNA sequencing and/or biochemical testing. Isolates that failed to report as a "high confidence species ID" [log(score) ≥2.00] were re-tested using an extraction method. The MBT-CA System identified 96.8% and 3.1% of isolates with either a "high confidence" or a "low confidence" [log(score) value between 1.70 and <2.00] species ID, respectively. Two isolates did not produce acceptable confidence scores after extraction. The MBT-CA System correctly identified 99.8% (2,258/2,263) to genus and 98.2% (2,222/2,263) to species level. These data demonstrate that the MBT-CA System provides accurate results for the identification of aerobic gram-negative bacteria.

  2. Non-oral gram-negative facultative rods in chronic periodontitis microbiota.

    Science.gov (United States)

    van Winkelhoff, Arie J; Rurenga, Patrick; Wekema-Mulder, Gepke J; Singadji, Zadrach M; Rams, Thomas E

    2016-05-01

    The subgingival prevalence of gram-negative facultative rods not usually inhabiting or indigenous to the oral cavity (non-oral GNFR), as well as selected periodontal bacterial pathogens, were evaluated by culture in untreated and treated chronic periodontitis patients. Subgingival biofilm specimens from 102 untreated and 101 recently treated adults with chronic periodontitis in the Netherlands were plated onto MacConkey III and Dentaid selective media with air-5% CO2 incubation for isolation of non-oral GNFR, and onto enriched Oxoid blood agar with anaerobic incubation for recovery of selected periodontal bacterial pathogens. Suspected non-oral GNFR clinical isolates were identified to a species level with the VITEK 2 automated system. A total of 87 (42.9%) out of 203 patients yielded subgingival non-oral GNFR. Patients recently treated with periodontal mechanical debridement therapy demonstrated a greater prevalence of non-oral GNFR (57.4% vs 28.4%, P chronic periodontitis patients yielded cultivable non-oral GNFR in periodontal pockets, particularly among those recently treated with periodontal mechanical debridement therapy. Since non-oral GNFR species may resist mechanical debridement from periodontal pockets, and are often not susceptible to many antibiotics frequently used in periodontal practice, their subgingival presence may complicate periodontal treatment in species-positive patients and increase risk of potentially dangerous GNFR infections developing at other body sites. Copyright © 2016 Elsevier Ltd. All rights reserved.

  3. A robust single-beam optical trap for a gram-scale mechanical oscillator.

    Science.gov (United States)

    Altin, P A; Nguyen, T T-H; Slagmolen, B J J; Ward, R L; Shaddock, D A; McClelland, D E

    2017-11-06

    Precise optical control of microscopic particles has been mastered over the past three decades, with atoms, molecules and nano-particles now routinely trapped and cooled with extraordinary precision, enabling rapid progress in the study of quantum phenomena. Achieving the same level of control over macroscopic objects is expected to bring further advances in precision measurement, quantum information processing and fundamental tests of quantum mechanics. However, cavity optomechanical systems dominated by radiation pressure - so-called 'optical springs' - are inherently unstable due to the delayed dynamical response of the cavity. Here we demonstrate a fully stable, single-beam optical trap for a gram-scale mechanical oscillator. The interaction of radiation pressure with thermo-optic feedback generates damping that exceeds the mechanical loss by four orders of magnitude. The stability of the resultant spring is robust to changes in laser power and detuning, and allows purely passive self-locking of the cavity. Our results open up a new way of trapping and cooling macroscopic objects for optomechanical experiments.

  4. Biofilms Formed by Gram-Negative Bacteria Undergo Increased Lipid A Palmitoylation, Enhancing In Vivo Survival

    Science.gov (United States)

    Chalabaev, Sabina; Chauhan, Ashwini; Novikov, Alexey; Iyer, Pavithra; Szczesny, Magdalena; Beloin, Christophe; Caroff, Martine

    2014-01-01

    ABSTRACT Bacterial biofilm communities are associated with profound physiological changes that lead to novel properties compared to the properties of individual (planktonic) bacteria. The study of biofilm-associated phenotypes is an essential step toward control of deleterious effects of pathogenic biofilms. Here we investigated lipopolysaccharide (LPS) structural modifications in Escherichia coli biofilm bacteria, and we showed that all tested commensal and pathogenic E. coli biofilm bacteria display LPS modifications corresponding to an increased level of incorporation of palmitate acyl chain (palmitoylation) into lipid A compared to planktonic bacteria. Genetic analysis showed that lipid A palmitoylation in biofilms is mediated by the PagP enzyme, which is regulated by the histone-like protein repressor H-NS and the SlyA regulator. While lipid A palmitoylation does not influence bacterial adhesion, it weakens inflammatory response and enhances resistance to some antimicrobial peptides. Moreover, we showed that lipid A palmitoylation increases in vivo survival of biofilm bacteria in a clinically relevant model of catheter infection, potentially contributing to biofilm tolerance to host immune defenses. The widespread occurrence of increased lipid A palmitoylation in biofilms formed by all tested bacteria suggests that it constitutes a new biofilm-associated phenotype in Gram-negative bacteria. PMID:25139899

  5. RNA degradation in Archaea and Gram-negative bacteria different from Escherichia coli.

    Science.gov (United States)

    Evguenieva-Hackenberg, Elena; Klug, Gabriele

    2009-01-01

    Exoribonucleolytic and endoribonucleolytic activities are important for controlled degradation of RNA and contribute to the regulation of gene expression at the posttranscriptional level by influencing the half-lives of specific messenger RNAs. The RNA half-lives are determined by the characteristics of the RNA substrates and by the availability and the properties of the involved proteins-ribonucleases and assisting polypeptides. Much is known about RNA degradation in Eukarya and Bacteria, but there is limited information about RNA-degrading enzymes and RNA destabilizing or stabilizing elements in the domain of the Archaea. The recent progress in the understanding of the structure and function of the archaeal exosome, a protein complex with RNA-degrading and RNA-tailing capabilities, has given some first insights into the mechanisms of RNA degradation in the third domain of life and into the evolution of RNA-degrading enzymes. Moreover, other archaeal RNases with degrading potential have been described and a new mechanism for protection of the 5'-end of RNA in Archaea was discovered. Here, we summarize the current knowledge on RNA degradation in the Archaea. Additionally, RNA degradation mechanisms in Rhodobacter capsulatus and Pseudomonas syringae are compared to those in the major model organism for Gram-negatives, Escherichia coli, which dominates our view on RNA degradation in Bacteria.

  6. Green synthesis of silver nanoparticles using methanolic root extracts of Diospyros paniculata and their antimicrobial activities.

    Science.gov (United States)

    Rao, N Hanumanta; N, Lakshmidevi; Pammi, S V N; Kollu, Pratap; S, Ganapaty; P, Lakshmi

    2016-05-01

    Since the discovery and subsequent widespread use of antibiotics, a variety of bacterial species of human and animal origin have developed numerous mechanisms that render bacteria resistant to some, and in certain cases to nearly all antibiotics, thereby limiting the treatment options and compromising effective therapy. In the present study, the green synthesis of nanoparticles is carried out by the reduction of silver acetate in the presence of crude methanolic root extracts of Diospyros paniculata, a member of family Ebenaceae. The UV-Vis absorption spectrum of the biologically reduced reaction mixture showed the surface plasmon peak at 428 nm, a characteristic peak of silver nanoparticles. X-ray diffraction (XRD) analysis confirmed the face-centered cubic crystalline structure of metallic silver. The average diameter of Ag NPs is about 17 nm from Transmission Electron Microscopy (TEM) which is in good agreement with the average crystallite size (19 nm) calculated from XRD analysis. Further the study has been extended to the antimicrobial activity against test pathogenic Gram (+), Gram (-) bacterial and fungal strains. The biologically synthesized silver nanoparticles showed promising activity against all the tested pathogenic strains and the activity has been enhanced with the increased dose levels. Copyright © 2016 Elsevier B.V. All rights reserved.

  7. Diverse Gram-positive bacteria identified from raw and pasteurized ...

    African Journals Online (AJOL)

    tion practices associated with milking and storage equipment. ... materials, various ingredients added to dairy products and dairy farm work- ers. ... 7°E, respectively and 2200 meter above sea level, respectively. The an- ... storage facilities, and shelf life of the pasteurized milk. ... transferred into a sterile screw capped bottle.

  8. Organic synthesis

    International Nuclear Information System (INIS)

    Lallemand, J.Y.; Fetizon, M.

    1988-01-01

    The 1988 progress report of the Organic Synthesis Chemistry laboratory (Polytechnic School, France), is presented. The laboratory activities are centered on the chemistry of natural products, which have a biological activity and on the development of new reactions, useful in the organic synthesis. The research works involve the following domains: the natural products chemistry which are applied in pharmacology, the plants and insects chemistry, the organic synthesis, the radical chemistry new reactions and the bio-organic physicochemistry. The published papers, the congress communications and the thesis are listed [fr

  9. Gram stains: a resource for retrospective analysis of bacterial pathogens in clinical studies.

    Science.gov (United States)

    Srinivasan, Usha; Ponnaluri, Sreelatha; Villareal, Lisa; Gillespie, Brenda; Wen, Ai; Miles, Arianna; Bucholz, Brigette; Marrs, Carl F; Iyer, Ram K; Misra, Dawn; Foxman, Betsy

    2012-01-01

    We demonstrate the feasibility of using qPCR on DNA extracted from vaginal Gram stain slides to estimate the presence and relative abundance of specific bacterial pathogens. We first tested Gram stained slides spiked with a mix of 10(8) cfu/ml of Escherichia coli and 10(5) cfu/ml of Lactobacillus acidophilus. Primers were designed for amplification of total and species-specific bacterial DNA based on 16S ribosomal gene regions. Sample DNA was pre-amplified with nearly full length 16S rDNA ribosomal gene fragment, followed by quantitative PCR with genera and species-specific 16S rDNA primers. Pre-amplification PCR increased the bacterial amounts; relative proportions of Escherichia coli and Lactobacillus recovered from spiked slides remained unchanged. We applied this method to forty two archived Gram stained slides available from a clinical trial of cerclage in pregnant women at high risk of preterm birth. We found a high correlation between Nugent scores based on bacterial morphology of Lactobacillus, Gardenerella and Mobiluncus and amounts of quantitative PCR estimated genus specific DNA (rrn copies) from Gram stained slides. Testing of a convenience sample of eight paired vaginal swabs and Gram stains freshly collected from healthy women found similar qPCR generated estimates of Lactobacillus proportions from Gram stained slides and vaginal swabs. Archived Gram stained slides collected from large scale epidemiologic and clinical studies represent a valuable, untapped resource for research on the composition of bacterial communities that colonize human mucosal surfaces.

  10. Gram and acridine orange staining for diagnosis of septic arthritis in different patient populations.

    Science.gov (United States)

    Cunningham, Gregory; Seghrouchni, Khalid; Ruffieux, Etienne; Vaudaux, Pierre; Gayet-Ageron, Angèle; Cherkaoui, Abdessalam; Godinho, Eduardo; Lew, Daniel; Hoffmeyer, Pierre; Uçkay, Ilker

    2014-06-01

    The sensitivity of Gram staining is known to be suboptimal for the diagnosis of native joint septic arthritis. We lack information about the accuracy of Gram compared to other microscopic staining techniques for predicting infection in different patient populations. This was a cohort study with cost evaluations at the Orthopaedic Service of Geneva University Hospitals (January 1996-October 2012). Among 500 episodes of arthritis (196 with immunosuppression, 227 with underlying arthroplasties and 69 with gout or other crystals in synovial fluid), Gram staining revealed pathogens in 146 episodes (146/500, 29 %) or in 146 of the 400 culture-positive episodes (37 %). Correlation between the Gram and acridine staining of the same sample was good (Spearman 0.85). Overall, the sensitivity, specificity, positive predictive value and negative predictive value of Gram stain for rapid diagnosis of septic arthritis was 0.37, 0.99, 0.99 and 0.28, respectively, compared to microbiological cultures. Quite similar values were recorded across the different patient subpopulations, in particular for sensitivity values that were 0.33 for patients with prosthetic joint infections, 0.40 for immunosuppressed patients, 0.36 for patients under antibiotic administration and 0.52 for patients with concomitant crystalline disease. The sensitivity of Gram or acridine orange staining for a rapid diagnosis of episodes of septic arthritis is suboptimal compared to microbiological culture, regardless of underlying conditions, immunosuppression or antibiotic therapy. The sensitivity in the presence of synovial fluid crystals is moderate. Acridine orange and Gram stains are equivalent.

  11. Screening of antibiotic susceptibility to β-lactam-induced elongation of Gram-negative bacteria based on dielectrophoresis.

    Science.gov (United States)

    Chung, Cheng-Che; Cheng, I-Fang; Chen, Hung-Mo; Kan, Heng-Chuan; Yang, Wen-Horng; Chang, Hsien-Chang

    2012-04-03

    We demonstrate a rapid antibiotic susceptibility test (AST) based on the changes in dielectrophoretic (DEP) behaviors related to the β-lactam-induced elongation of Gram-negative bacteria (GNB) on a quadruple electrode array (QEA). The minimum inhibitory concentration (MIC) can be determined within 2 h by observing the changes in the positive-DEP frequency (pdf) and cell length of GNB under the cefazolin (CEZ) treatment. Escherichia coli and Klebsiella pneumoniae and the CEZ are used as the sample bacteria and antibiotic respectively. The bacteria became filamentous due to the inhibition of cell wall synthesis and cell division and cell lysis occurred for the higher antibiotic dose. According to the results, the pdfs of wild type bacteria decrease to hundreds of kHz and the cell length is more than 10 μm when the bacterial growth is inhibited by the CEZ treatment. In addition, the growth of wild type bacteria and drug resistant bacteria differ significantly. There is an obvious decrease in the number of wild type bacteria but not in the number of drug resistant bacteria. Thus, the drug resistance of GNB to β-lactam antibiotics can be rapidly assessed. Furthermore, the MIC determined using dielectrophoresis-based AST (d-AST) was consistent with the results of the broth dilution method. Utilizing this approach could reduce the time needed for bacteria growth from days to hours, help physicians to administer appropriate antibiotic dosages, and reduce the possibility of the occurrence of multidrug resistant (MDR) bacteria.

  12. Multi-location gram-positive and gram-negative bacterial protein subcellular localization using gene ontology and multi-label classifier ensemble.

    Science.gov (United States)

    Wang, Xiao; Zhang, Jun; Li, Guo-Zheng

    2015-01-01

    It has become a very important and full of challenge task to predict bacterial protein subcellular locations using computational methods. Although there exist a lot of prediction methods for bacterial proteins, the majority of these methods can only deal with single-location proteins. But unfortunately many multi-location proteins are located in the bacterial cells. Moreover, multi-location proteins have special biological functions capable of helping the development of new drugs. So it is necessary to develop new computational methods for accurately predicting subcellular locations of multi-location bacterial proteins. In this article, two efficient multi-label predictors, Gpos-ECC-mPLoc and Gneg-ECC-mPLoc, are developed to predict the subcellular locations of multi-label gram-positive and gram-negative bacterial proteins respectively. The two multi-label predictors construct the GO vectors by using the GO terms of homologous proteins of query proteins and then adopt a powerful multi-label ensemble classifier to make the final multi-label prediction. The two multi-label predictors have the following advantages: (1) they improve the prediction performance of multi-label proteins by taking the correlations among different labels into account; (2) they ensemble multiple CC classifiers and further generate better prediction results by ensemble learning; and (3) they construct the GO vectors by using the frequency of occurrences of GO terms in the typical homologous set instead of using 0/1 values. Experimental results show that Gpos-ECC-mPLoc and Gneg-ECC-mPLoc can efficiently predict the subcellular locations of multi-label gram-positive and gram-negative bacterial proteins respectively. Gpos-ECC-mPLoc and Gneg-ECC-mPLoc can efficiently improve prediction accuracy of subcellular localization of multi-location gram-positive and gram-negative bacterial proteins respectively. The online web servers for Gpos-ECC-mPLoc and Gneg-ECC-mPLoc predictors are freely accessible

  13. From Farms to Markets: Gram-Negative Bacteria Resistant to Third-Generation Cephalosporins in Fruits and Vegetables in a Region of North Africa

    OpenAIRE

    Mesbah Zekar, Ferielle; Granier, Sophie A.; Marault, Muriel; Yaici, Lydia; Gassilloud, Benoit; Manceau, Charles; Touati, Abdelaziz; Millemann, Yves

    2017-01-01

    The role of food in human exposure to antimicrobial-resistant bacteria is a growing food safety issue. The contribution of fruits and vegetables eaten raw to this exposure is still unclear. The evaluation of contamination levels of fruits, vegetables and the agricultural environment by third-generation cephalosporin (3GC)-resistant Gram-negative bacteria was performed by analyzing 491 samples of fruits and vegetables collected from 5 markets and 7 farms in Bejaia area, north-eastern Mediterra...

  14. Enantioselective synthesis of the novel chiral sulfoxide derivative as a glycogen synthase kinase 3beta inhibitor.

    Science.gov (United States)

    Saitoh, Morihisa; Kunitomo, Jun; Kimura, Eiji; Yamano, Toru; Itoh, Fumio; Kori, Masakuni

    2010-09-01

    Glycogen synthase kinase 3beta (GSK-3beta) inhibitors are expected to be attractive therapeutic agents for the treatment of Alzheimer's disease (AD). Recently we discovered sulfoxides (S)-1 as a novel GSK-3beta inhibitor having in vivo efficacy. We investigated practical asymmetric preparation methods for the scale-up synthesis of (S)-1. The highly enantioselective synthesis of (S)-1 (94% ee) was achieved by titanium-mediated oxidation with D-(-)-diethyl tartrate on gram scale.

  15. Crystallization and preliminary X-ray analysis of three dUTPases from Gram-positive bacteria

    International Nuclear Information System (INIS)

    Li, Gui-Lan; Wang, Juan; Li, Lan-Fen; Su, Xiao-Dong

    2009-01-01

    All organisms examined to date possess a dUTPase that performs the important function of efficiently hydrolyzing dUTP to dUMP in order to prevent the incorporation of dUTP into DNA. Three putative dUTPases from Gram-positive bacteria have been studied in this work. All organisms examined to date possess a dUTPase that performs the important function of efficiently hydrolyzing dUTP to dUMP in order to prevent the incorporation of dUTP into DNA. Three putative dUTPases from Gram-positive bacteria have been studied in this work. Two dUTPase-encoding genes, yncF and yosS, have been identified in Bacillus subtilis. The gene dut, encoding dUTPase from the dental pathogen Streptococcus mutans, was amplified from S. mutans genomic DNA. The three genes were cloned into expression vectors and overexpressed at high levels in Escherichia coli. Each protein was purified in two steps using chromatographic methods. Crystals of the YosS and YncF proteins and of S. mutans dUTPase were obtained using the vapour-diffusion method. X-ray diffraction data sets were collected from crystals of selenomethionine-labelled YosS and S. mutans dUTPase to resolutions of 2.3 and 1.7 Å, respectively. The crystal of native YncF diffracted to 2.7 Å resolution

  16. Determination of the irradiation dose for the inhibition (D-10 radiation doses) of some gram negative and gram positive bacteria in peptone saline water

    International Nuclear Information System (INIS)

    Ayhan, H.; Tutluer, H.

    1994-01-01

    Determination of the irradiation dose for the inhibition of some pathogenic bacteria which cause food poisoning and spoilage were aimed. For this purpose, Salmonella typhi, Salmonella typhimurium,Salmonella enteridits,Klebsiella pneumonia, Pseudomonas fluorescence,Proteus vulgaris, Aeromonas hydrophila ,(gram-negative bacteria) and Bacillus cereus, Staphylococcus aureus strain 24,Staphylococcus aureus ATCC 6538 P,Staphylococcus epidermidis strain 115 and Clostridium perfringens A4TTK,(gram-positive bacteria) were used.Sensitivity of above mentioned bacteria to gamma rays (source Cs-137) was examined in saline with 0.1% peptone at different temperatures.Survivor plots (log.10 number of survivors versus dose) were determined by regression analysis of the data.Decimal reduction doses (D values in kGy) were calculated as the slope obtained from the regression analysis

  17. [Influence of serious infections due to Gram-negative bacteria on the hospital economy].

    Science.gov (United States)

    Martínez, B; Gómez, J; Gómez Vargas, J; Guerra, B; Ruiz Gómez, J; Simarro, E; Baños, V; Canteras, M; Valdes, M

    2000-12-01

    Nosocomial infections due to Gram-negative bacteria are very important since they are associated with high morbidity and high hospital costs. A prospective study of 250 inpatients was carried out, 200 of whom had Gram-negative bacterial infections. Patients were divided into groups of 50 according to the localization of the infection (urinary, surgical wound, respiratory tract and bacteremia), with a control group of 50 patients with similar characteristics but no infection. We calculated the cost for the different groups by multiplying the average length of hospital stay in days by the daily cost of the stay. Significant differences were observed in the average length of stay per patient according to the type of infection and how it was acquired. In terms of cost, nosocomial infection due to Gram-negative bacteria was 1,049,139 pesetas more expensive than community-acquired infection. The cost of the stay for patients with postsurgical infection due to Gram-negative bacteria was 1,108, 252 pesetas more expensive than for the group of control patients. Nosocomial infection due to Gram-negative bacteria is associated with a prolongation in hospital stay of 9 to 28 days, which is the factor that most reflects the cost that can be attributed to nosocomial infection. Consensual and protocolized measures which allow for better clinical management need to be developed.

  18. Green Gram Rotation Effects on Maize Growth Parameters and Soil Quality in Myanmar

    Directory of Open Access Journals (Sweden)

    Myo Kywe

    2008-10-01

    Full Text Available At present maize–green gram crop rotations are not widely practiced among farmers in Myanmar. However, this cropping system might become more popular in the future given raising prices for green gram and maize grain and scarcity of mineral nitrogen (N fertilizers in this Asian country. The results of a cropping systems experiment with continuous maize versus a green gram-maize rotation, manure application (0 and 2 t ha−1 and phosphorus (P fertilization (0 and 15 kg P ha−1 in each of five consecutive seasons revealed a strong decline in total dry matter and grains yields for both crops irrespective of the treatment. Treatment effects on yield components, nutrient concentrations, mycorrhizal infection and nematode infestation were small or negligible. The data show that in addition to manure used at 2 t ha−1, application of mineral N fertilizers is essential to maintain particularly maize yields. A comparison of different green gram cultivars did not indicate genotype specific effects on maize growth. The incorporation of legume residues, unless they are used as animal feed, is recommended to increase the recycling of N and to balance N fluxes when green gram is cultivated for seed.

  19. Gram-typing of mastitis bacteria in milk samples using flow cytometry

    DEFF Research Database (Denmark)

    Langerhuus, Sine Nygaard; Ingvartsen, Klaus Lønne; Bennedsgaard, Torben Werner

    2013-01-01

    Fast identification of pathogenic bacteria in milk samples from cows with clinical mastitis is central to proper treatment. In Denmark, time to bacterial diagnosis is typically 24 to 48 h when using traditional culturing methods. The PCR technique provides a faster and highly sensitive identifica......Fast identification of pathogenic bacteria in milk samples from cows with clinical mastitis is central to proper treatment. In Denmark, time to bacterial diagnosis is typically 24 to 48 h when using traditional culturing methods. The PCR technique provides a faster and highly sensitive...... cytometry-based method, which can detect and distinguish gram-negative and gram-positive bacteria in mastitis milk samples. The differentiation was based on bacterial fluorescence intensities upon labeling with biotin-conjugated wheat germ agglutinin and acridine orange. Initially 19 in-house bacterial...... characteristic curves for the 19 bacterial cultures. The method was then tested on 53 selected mastitis cases obtained from the department biobank (milk samples from 6 gram-negative and 47 gram-positive mastitis cases). Gram-negative bacteria in milk samples were detected with a sensitivity of 1...

  20. Bacteremias in liver transplant recipients: shift toward gram-negative bacteria as predominant pathogens.

    Science.gov (United States)

    Singh, Nina; Wagener, Marilyn M; Obman, Asia; Cacciarelli, Thomas V; de Vera, Michael E; Gayowski, Timothy

    2004-07-01

    During the 1990s, gram-positive bacteria emerged as major pathogens after liver transplantation. We sought to determine whether the pathogens associated with bacteremias in liver transplant recipients have changed. Patients included 233 liver transplant recipients transplanted between 1989 and 2003. The proportion of all infections due to bacteremias increased significantly over time (P gram-negatives increased from 25% in the period of 1989-1993 to 51.8% in 1998-03, that of gram-positive bacteria decreased from 75% in the period of 1989-93 to 48.2% in the period of 1998-2003. Methicillin-resistant Staphylococcus aureus (MRSA), Klebsiella pneumoniae, and Pseudomonas aeruginosa were the most frequent pathogens in bacteremic patients. The incidence of bacteremias due to MRSA and Pseudomonas aeruginosa has remained unchanged (P gram-negative bacteria, particularly Klebsiella pneumoniae has increased (P =.02). Klebsiella pneumoniae isolates in the current quartile were not clonally related. In conclusion, bacteremias as a proportion of all infections in liver transplant recipients have increased significantly over time, due in part to a decline in infections due to other major pathogens, e.g., fungi, primarily Candida species, and CMV. Gram-negative bacteria have emerged as predominant pathogens in bacteremic liver transplant recipients.

  1. Fast Structural Alignment of Biomolecules Using a Hash Table, N-Grams and String Descriptors

    Directory of Open Access Journals (Sweden)

    Robert Preissner

    2009-04-01

    Full Text Available This work presents a generalized approach for the fast structural alignment of thousands of macromolecular structures. The method uses string representations of a macromolecular structure and a hash table that stores n-grams of a certain size for searching. To this end, macromolecular structure-to-string translators were implemented for protein and RNA structures. A query against the index is performed in two hierarchical steps to unite speed and precision. In the first step the query structure is translated into n-grams, and all target structures containing these n-grams are retrieved from the hash table. In the second step all corresponding n-grams of the query and each target structure are subsequently aligned, and after each alignment a score is calculated based on the matching n-grams of query and target. The extendable framework enables the user to query and structurally align thousands of protein and RNA structures on a commodity machine and is available as open source from http://lajolla.sf.net.

  2. A molecular gram stain using broad range PCR and pyrosequencing technology: a potentially useful tool for diagnosing orthopaedic infections.

    Science.gov (United States)

    Kobayashi, Naomi; Bauer, Thomas W; Togawa, Daisuke; Lieberman, Isador H; Sakai, Hiroshige; Fujishiro, Takaaki; Tuohy, Marion J; Procop, Gary W

    2005-06-01

    The bacteria associated with orthopaedic infections are usually common gram-positive and gram-negative bacteria. This fundamental grouping of bacteria is a necessary first step in the selection of appropriate antibiotics. Since polymerase chain reaction (PCR) is more rapid and may be more sensitive than culture, we developed a postamplification pyrosequencing method to subcategorize bacteria based on a few nucleotide polymorphisms in the 16S rRNA gene. We validated this method using well-characterized strains of bacteria and applied it to specimens from spinal surgery cases with suspected infections. Lysates of 114 bacteria including 75 species were created following standard cultivation to obtain DNA. The DNA was amplified by a broad-range real-time PCR. The amplicons were evaluated by pyrosequencing and were classified as gram-positive, gram-negative, or acid-fast bacilli based on the first three to five nucleotides sequenced. In addition, clinical cases of suspected infection were obtained from spinal surgery. The results of the "molecular Gram stain" were compared with the results of traditional Gram stain and culture. The lysates of 107 (93.9%) of the bacteria extracts tested were appropriately categorized as gram-positive and gram-negative or as acid-fast bacilli on the basis of this assay. The sensitivity and specificity of this assay were 100% and 97.4% for gram-positive and 88.3% and 100% for gram-negative isolates. All of the five clinical samples were appropriately categorized as containing gram-positive or gram-negative bacteria with this assay. This study demonstrates that high sensitivity and specificity of a molecular gram stain may be achieved using broad-range real-time PCR and pyrosequencing.

  3. Making every gram count - Big measurements from tiny platforms (Invited)

    Science.gov (United States)

    Fish, C. S.; Neilsen, T. L.; Stromberg, E. M.

    2013-12-01

    The most significant advances in Earth, solar, and space physics over the next decades will originate from new, system-level observational techniques. The most promising technique to still be fully developed and exploited requires conducting multi-point or distributed constellation-based observations. This system-level observational approach is required to understand the 'big picture' coupling between disparate regions such as the solar-wind, magnetosphere, ionosphere, upper atmosphere, land, and ocean. The national research council, NASA science mission directorate, and the larger heliophysics community have repeatedly identified the pressing need for multipoint scientific investigations to be implemented via satellite constellations. The NASA Solar Terrestrial Probes Magnetospheric Multiscale (MMS) mission and NASA Earth Science Division's 'A-train', consisting of the AQUA, CloudSat, CALIPSO and AURA satellites, are examples of such constellations. However, the costs to date of these and other similar proposed constellations have been prohibitive given the 'large satellite' architectures and the multiple launch vehicles required for implementing the constellations. Financially sustainable development and deployment of multi-spacecraft constellations can only be achieved through the use of small spacecraft that allow for multiple hostings per launch vehicle. The revolution in commercial mobile and other battery powered consumer technology has helped enable researchers in recent years to build and fly very small yet capable satellites, principally CubeSats. A majority of the CubeSat activity and development to date has come from international academia and the amateur radio satellite community, but several of the typical large-satellite vendors have developed CubeSats as well. Recent government-sponsored CubeSat initiatives, such as the NRO Colony, NSF CubeSat Space Weather, NASA Office of Chief Technologist Edison and CubeSat Launch Initiative (CSLI) Educational

  4. Nucleotide sequence alignment of hdcA from Gram-positive bacteria.

    Science.gov (United States)

    Diaz, Maria; Ladero, Victor; Redruello, Begoña; Sanchez-Llana, Esther; Del Rio, Beatriz; Fernandez, Maria; Martin, Maria Cruz; Alvarez, Miguel A

    2016-03-01

    The decarboxylation of histidine -carried out mainly by some gram-positive bacteria- yields the toxic dietary biogenic amine histamine (Ladero et al. 2010 〈10.2174/157340110791233256〉 [1], Linares et al. 2016 〈http://dx.doi.org/10.1016/j.foodchem.2015.11.013〉〉 [2]). The reaction is catalyzed by a pyruvoyl-dependent histidine decarboxylase (Linares et al. 2011 〈10.1080/10408398.2011.582813〉 [3]), which is encoded by the gene hdcA. In order to locate conserved regions in the hdcA gene of Gram-positive bacteria, this article provides a nucleotide sequence alignment of all the hdcA sequences from Gram-positive bacteria present in databases. For further utility and discussion, see 〈http://dx.doi.org/ 10.1016/j.foodcont.2015.11.035〉〉 [4].

  5. [Antimicrobial therapy in severe infections with multidrug-resistant Gram-negative bacterias].

    Science.gov (United States)

    Duszyńska, Wiesława

    2010-01-01

    Multidrug-resistant Gram-negative bacteria pose a serious and rapidly emerging threat to patients in healthcare settings, and are especially prevalent and problematic in intensive therapy units. Recently, the emergence of pandrug-resistance in Gram-negative bacteria poses additional concerns. This review examines the clinical impact and epidemiology of multidrug-resistant Gram-negative bacteria as a cause of increased morbidity and mortality among ITU patients. Beta-lactamases, cephalosporinases and carbapenemases play the most important role in resistance to antibiotics. Despite the tendency to increased resistance, carbapenems administered by continuous infusion remain the most effective drugs in severe sepsis. Drug concentration monitoring, albeit rarely used in practice, is necessary to ensure an effective therapeutic effect.

  6. Efficient n-gram, Skipgram and Flexgram Modelling with Colibri Core

    Directory of Open Access Journals (Sweden)

    Maarten van Gompel

    2016-08-01

    Full Text Available Counting n-grams lies at the core of any frequentist corpus analysis and is often considered a trivial matter. Going beyond consecutive n-grams to patterns such as skipgrams and flexgrams increases the demand for efficient solutions. The need to operate on big corpus data does so even more. Lossless compression and non-trivial algorithms are needed to lower the memory demands, yet retain good speed. Colibri Core is software for the efficient computation and querying of n-grams, skipgrams and flexgrams from corpus data. The resulting pattern models can be analysed and compared in various ways. The software offers a programming library for C++ and Python, as well as command-line tools.

  7. Electrochemical reduction of oxygen catalyzed by a wide range of bacteria including Gram-positive

    Energy Technology Data Exchange (ETDEWEB)

    Cournet, Amandine [Universite de Toulouse, UPS, LU49, Adhesion Bacterienne et Formation de Biofilms, 35 chemin des Maraichers, 31 062 Toulouse cedex 09 (France); Laboratoire de Genie Chimique CNRS, Universite de Toulouse, 4 allee Emile Monso, BP 84234, 31432 Toulouse cedex 04 (France); Delia, Marie-Line; Bergel, Alain [Laboratoire de Genie Chimique CNRS, Universite de Toulouse, 4 allee Emile Monso, BP 84234, 31432 Toulouse cedex 04 (France); Roques, Christine; Berge, Mathieu [Universite de Toulouse, UPS, LU49, Adhesion Bacterienne et Formation de Biofilms, 35 chemin des Maraichers, 31 062 Toulouse cedex 09 (France)

    2010-04-15

    Most bacteria known to be electrochemically active have been harvested in the anodic compartments of microbial fuel cells (MFCs) and are able to use electrodes as electron acceptors. The reverse phenomenon, i.e. using solid electrodes as electron donors, is not so widely studied. To our knowledge, most of the electrochemically active bacteria are Gram-negative. The present study implements a transitory electrochemical technique (cyclic voltammetry) to study the microbial catalysis of the electrochemical reduction of oxygen. It is demonstrated that a wide range of aerobic and facultative anaerobic bacteria are able to catalyze oxygen reduction. Among these electroactive bacteria, several were Gram-positive. The transfer of electrons was direct since no activity was obtained with the filtrate. These findings, showing a widespread property among bacteria including Gram-positive ones, open new and interesting routes in the field of electroactive bacteria research. (author)

  8. Epidemiology of infections caused by multiresistant gram-negatives: ESBLs, MBLs, panresistant strains.

    Science.gov (United States)

    Rossolini, Gian Maria; Mantengoli, Elisabetta; Docquier, Jean-Denis; Musmanno, Rosa Anna; Coratza, Grazietta

    2007-07-01

    Microbial drug resistance is a growing problem of global magnitude. In gram-negative pathogens, the most important resistance problems are encountered in Enterobacteriaceae, Pseudomonas aeruginosa and Acinetobacter, with increasing trends observed for all major anti-gram-negative agents (beta-lactams, fluoroquinolones and aminoglycosides). A matter of major concern is the emergence of new beta-lactamases capable of degrading the expanded-spectrum cephalosporins and/or carbapenems, such as the extended-spectrum beta-lactamases (ESBLs) and the carbapenemases. These beta-lactamase genes are often associated with resistance determinants to non-beta-lactam agents (e.g. aminoglycosides and fluoroquinolones), and strains producing ESBLs or carbapenemases often exhibit complex multidrug resistant phenotypes and sometimes are panresistant. The problem is worsened by the dearth of new agents active on multidrug-resistant Gram-negatives in the pipeline. The importance to develop better strategies to control resistance is underscored.

  9. STUDY ON SURGICAL SITE INFECTIONS CAUSED BY ESBL PRODUCING GRAM NEGATIVE BACTERIA

    Directory of Open Access Journals (Sweden)

    Rambabu

    2015-09-01

    Full Text Available Surgical site infections have been a major problem, because of the emergence of drug resistant bacteria, in particular B - lactamase producing bacteria. Extended spectrum beta lactamase producing gram negative organisms pose a great challenge in treatment o f SSI present study is aimed at determining multiple drug resistance in gram negative bacteria & to find out ESBL producers, in correlation with treatment outcome. A total of 120 wound infected cases were studied. Staphylococcus aureus was predominant bact erium - 20.Among gram negative bacteria, Pseudomonas species is predominant (14 followed by Escherichia coli (13 , Klebsiella species (12 , Proteus (9 Citrobacter (4 Providencia (2 & Acinetobacter species (2 . Out of 56 gramnegative bacteria isolated, 20 were i dentified as ESBL producers, which was statistically significant. Delay in wound healing correlated with infection by ESBL producers, which alarms the need of abstinence from antibiotic abuse

  10. Prebiotic Polymer Synthesis and the Origin of Glycolytic Metabolism

    Science.gov (United States)

    Weber, Arthur L.

    1998-01-01

    Our research resulted in several discoveries which contributed to understanding the origin and operation of life. (1) Most importantly, we discovered a new pathway of prebiotic amino acid synthesis in which formaldehyde and glycolaldehyde (formose reaction substrates) react with ammonia to give alanine and homoserine in the presence of thiol catalysts. The thiol-dependent synthesis of amino acids undoubtedly occurs via amino acid thioester intermediates capable of forming peptides. This 'one-pot' reaction system operates under mild aqueous conditions, and like modern amino acid biosynthesis, uses sugar intermediates which are converted to amino acids by energy-yielding redox disproportionation. Preliminary evidence suggests that this type of process can be "evolved" by a serial transfer methods that lead to enrichment of autocatalytic molecules. (2) We established that prebiotic peptide polymers can be made by condensation of amino acid thioesters (homocysteine thiolactone and S-(N-beta-orotidyl- diaminopropionic acid) ethanethiol), and that prebiotic polydisulfide polymers can be generated by oxidation of dithiols with iron(III) in minerals. (3) In our analysis of metabolism we discovered the primary energy source of biosynthesis -- chemical energy made available by the redox disproportionation of substrate carbon groups. We concluded that the energy and reactivity of sugars make them the optimal substrate for the origin and operation of terrestrial (or extraterrestrial) life. (4) Since it is likely that the use of optimal sugar substrates in biosynthesis sets the average oxidation number of functional biocarbon throughout the Universe near 0.0 (the reduction level of formaldehyde), we proposed that a line(s) in the microwave spectrum of formaldehyde could be rationally selected as a frequency for interstellar communication that symbolizes life. (5) Finally, in preparation for the analysis of Martian meteorite samples, we upgraded our HPLC system to one femtomole

  11. OMS-2-Supported Cu Hydroxide-Catalyzed Benzoxazoles Synthesis from Catechols and Amines via Domino Oxidation Process at Room Temperature.

    Science.gov (United States)

    Meng, Xu; Wang, Yanmin; Wang, Yuanguang; Chen, Baohua; Jing, Zhenqiang; Chen, Gexin; Zhao, Peiqing

    2017-07-07

    In the presence of manganese oxide octahedral molecular sieve (OMS-2) supported copper hydroxide Cu(OH) x /OMS-2, aerobic synthesis of benzoxazoles from catechols and amines via domino oxidation/cyclization at room temperature is achieved. This heterogeneous benzoxazoles synthesis initiated by the efficient oxidation of catechols over Cu(OH) x /OMS-2 tolerates a variety of substrates, especially amines containing sensitive groups (hydroxyl, cyano, amino, vinyl, ethynyl, ester, and even acetyl groups) and heterocycles, which affords functionalized benzoxazoles in good to excellent yields by employing low catalyst loading (2 mol % Cu). The characterization and plausible catalytic mechanism of Cu(OH) x /OMS-2 are described. The notable features of our catalytic protocol such as the use of air as the benign oxidant and EtOH as the solvent, mild conditions, ease of product separation, being scalable up to the gram level, and superior reusability of catalyst (up to 10 cycles) make it more practical and environmentally friendly for organic synthesis.

  12. A facile and rapid method for the black pepper leaf mediated green synthesis of silver nanoparticles and the antimicrobial study

    Science.gov (United States)

    Augustine, Robin; Kalarikkal, Nandakumar; Thomas, Sabu

    2014-10-01

    Green synthesis of nanoparticles is widely accepted due to the less toxicity in comparison with chemical methods. But there are certain drawbacks like slow formation of nanoparticles, difficulty to control particle size and shape make them less convenient. Here we report a novel cost-effective and eco-friendly method for the rapid green synthesis of silver nanoparticles using leaf extracts of Piper nigrum. Our results suggest that this method can be used for obtaining silver nanoparticles with controllable size within a few minutes. The fabricated nanoparticles possessed excellent antibacterial property against both Gram-positive and Gram-negative bacteria.

  13. Neonatal 6-hydroxydopamine treatment: Noradrenaline levels and in vitro 3H-catecholamine synthesis in discrete brain regions of adult rats

    NARCIS (Netherlands)

    Versteeg, D.H.G.; Ree, J.M. van; Provoost, Abraham P.; Jong, Wybren de

    1974-01-01

    Endogenous noradrenaline levels are elevated in medulla oblongata, mesencephalon, pons and thalamus of adult rats which had been treated with 6-hydroxydopamine on days 1, 2, 8 and 15 after birth. Levels in spinal cord, cerebellum, hippocampus/amygdala and cortex are depressed, whereas no significant

  14. Contribution of vertical land motions to coastal sea level variations: a global synthesis of multisatellite altimetry, tide gauge and GPS measurements

    Science.gov (United States)

    Pfeffer, Julia; Allemand, Pascal

    2016-04-01

    Coastal sea level variations result from a complex mix of climatic, oceanic and geodynamical processes driven by natural and anthropogenic constraints. Combining data from multiple sources is one solution to identify particular processes and progress towards a better understanding of the sea level variations and the assessment of their impacts at coast. Here, we present a global database merging multisatellite altimetry with tide gauges and Global Positioning System (GPS) measurements. Vertical land motions and sea level variations are estimated simultaneously for a network of 886 ground stations with median errors lower than 1 mm/yr. The contribution of vertical land motions to relative sea level variations is explored to better understand the natural hazards associated with sea level rise in coastal areas. Worldwide, vertical land motions dominate 30 % of observed coastal trends. The role of the crust is highly heterogeneous: it can amplify, restrict or counter the effects of climate-induced sea level change. A set of 182 potential vulnerable localities are identified by large coastal subsidence which increases by several times the effects of sea level rise. Though regional behaviours exist, principally caused by GIA (Glacial Isostatic Adjustment), the local variability in vertical land motion prevails. An accurate determination of the vertical motions observed at the coast is fundamental to understand the local processes which contribute to sea level rise, to appraise its impacts on coastal populations and make future predictions.

  15. The Toll pathway underlies host sexual dimorphism in resistance to both Gram-negative and Gram-positive bacteria in mated Drosophila.

    Science.gov (United States)

    Duneau, David F; Kondolf, Hannah C; Im, Joo Hyun; Ortiz, Gerardo A; Chow, Christopher; Fox, Michael A; Eugénio, Ana T; Revah, J; Buchon, Nicolas; Lazzaro, Brian P

    2017-12-21

    Host sexual dimorphism is being increasingly recognized to generate strong differences in the outcome of infectious disease, but the mechanisms underlying immunological differences between males and females remain poorly characterized. Here, we used Drosophila melanogaster to assess and dissect sexual dimorphism in the innate response to systemic bacterial infection. We demonstrated sexual dimorphism in susceptibility to infection by a broad spectrum of Gram-positive and Gram-negative bacteria. We found that both virgin and mated females are more susceptible than mated males to most, but not all, infections. We investigated in more detail the lower resistance of females to infection with Providencia rettgeri, a Gram-negative bacterium that naturally infects D. melanogaster. We found that females have a higher number of phagocytes than males and that ablation of hemocytes does not eliminate the dimorphism in resistance to P. rettgeri, so the observed dimorphism does not stem from differences in the cellular response. The Imd pathway is critical for the production of antimicrobial peptides in response to Gram-negative bacteria, but mutants for Imd signaling continued to exhibit dimorphism even though both sexes showed strongly reduced resistance. Instead, we found that the Toll pathway is responsible for the dimorphism in resistance. The Toll pathway is dimorphic in genome-wide constitutive gene expression and in induced response to infection. Toll signaling is dimorphic in both constitutive signaling and in induced activation in response to P. rettgeri infection. The dimorphism in pathway activation can be specifically attributed to Persephone-mediated immune stimulation, by which the Toll pathway is triggered in response to pathogen-derived virulence factors. We additionally found that, in absence of Toll signaling, males become more susceptible than females to the Gram-positive Enterococcus faecalis. This reversal in susceptibility between male and female Toll

  16. Risk factors for multidrug-resistant Gram-negative infection in burn patients.

    Science.gov (United States)

    Vickers, Mark L; Dulhunty, Joel M; Ballard, Emma; Chapman, Paul; Muller, Michael; Roberts, Jason A; Cotta, Menino O

    2018-05-01

    Infection with multidrug-resistant (MDR) Gram-negative organisms leads to poorer outcomes in the critically ill burn patient. The aim of this study was to identify the risk factors for MDR Gram-negative pathogen infection in critically ill burn patients admitted to a major tertiary referral intensive care unit (ICU) in Australia. A retrospective case-control study of all adult burn patients admitted over a 7-year period was conducted. Twenty-one cases that cultured an MDR Gram-negative organism were matched with 21 controls of similar age, gender, burn size and ICU stay. Multivariable conditional logistic regression was used to individually assess risk factors after adjusting for Acute Burn Severity Index. Adjusted odds ratios (ORs) were reported. P-values negative infection included superficial partial thickness burn size (OR: 1.08; 95% confidence interval (CI): 1.01-1.16; P-value: 0.034), prior meropenem exposure (OR: 10.39; 95% CI: 0.96-112.00; P-value: 0.054), Gram-negative colonization on admission (OR: 9.23; 95% CI: 0.65-130.15; P-value: 0.10) and escharotomy (OR: 2.66; 95% CI: 0.52-13.65; P-value: 0.24). For cases, mean age was 41 (SD: 13) years, mean total body surface area burned was 47% (SD: 18) and mean days in ICU until MDR specimen collection was 17 (SD: 10) days. Prior meropenem exposure, Gram-negative colonization on admission, escharotomy and superficial partial thickness burn size may be potentially important factors for increasing the risk of MDR Gram-negative infection in the critically ill burn patient. © 2017 Royal Australasian College of Surgeons.

  17. Extended spectrum beta-lactamases in urinary gram-negative bacilli and their susceptibility pattern

    International Nuclear Information System (INIS)

    Mumtaz, S.

    2008-01-01

    Beta-lactamases of gram-negative bacteria are the most important mechanism of resistance against beta lactams. Two types of beta-lactamases can confer resistance against third generation cephalosporins inducible Chromosomal beta -lactamases and extended-spectrum beta-lactamases. The extended-spectrum beta lactamases producing Strains of Enterobacteriaceae have emerged as a major problem in hospitalized as well as community based infections resulting in range of infections from uncomplicated urinary tract infection to life threatening sepsis. The study was conducted at the Microbiology Department of Fauji Foundation Hospital, Rawalpindi over a period of two years (April 2004-March 2006). Multidrug resistance and extended spectrum beta-lactamases production was studied in 111 enteric Gram-negative bacilli isolated from urine of symptomatic patients (1- 70 years) including males and females from indoor and outdoor patients by using double disc diffusion technique. Prevalence of extended-spectrum beta-lactamases production was seen in 71 (61.2%) enteric gram-negative organisms, the most prevalent gram-negative organism was Klebsiella pneumoniae 40 (71.4%) followed by Escherichia coli 27 (62.8%) and Pseudomonas aeruginosa 3 (25%). The extended-spectrum beta-lactamases producers were more prevalent in indoor patients 63 (88.7%) compared to outdoor patients 8 (11.3%), more in females 43 (60.6%) than males, 28 (39.4%). The extended-spectrum beta-lactamases producing gram-negative rods had more antibiotic-resistant profile than non-producers. All enteric gram negative rods should be tested for the production of extended-spectrum beta-lactamases in routine microbiology laboratory. (author)

  18. Overexpression of the endothelial protein C receptor is detrimental during pneumonia-derived gram-negative sepsis (Melioidosis.

    Directory of Open Access Journals (Sweden)

    Liesbeth M Kager

    Full Text Available The endothelial protein C receptor (EPCR enhances anticoagulation by accelerating activation of protein C to activated protein C (APC and mediates anti-inflammatory effects by facilitating APC-mediated signaling via protease activated receptor-1. We studied the role of EPCR in the host response during pneumonia-derived sepsis instigated by Burkholderia (B. pseudomallei, the causative agent of melioidosis, a common form of community-acquired Gram-negative (pneumosepsis in South-East Asia.Soluble EPCR was measured in plasma of patients with septic culture-proven melioidosis and healthy controls. Experimental melioidosis was induced by intranasal inoculation of B. pseudomallei in wild-type (WT mice and mice with either EPCR-overexpression (Tie2-EPCR or EPCR-deficiency (EPCR(-/-. Mice were sacrificed after 24, 48 or 72 hours. Organs and plasma were harvested to measure colony forming units, cellular influxes, cytokine levels and coagulation parameters. Plasma EPCR-levels were higher in melioidosis patients than in healthy controls and associated with an increased mortality. Tie2-EPCR mice demonstrated enhanced bacterial growth and dissemination to distant organs during experimental melioidosis, accompanied by increased lung damage, neutrophil influx and cytokine production, and attenuated coagulation activation. EPCR(-/- mice had an unremarkable response to B. pseudomallei infection as compared to WT mice, except for a difference in coagulation activation in plasma.Increased EPCR-levels correlate with accelerated mortality in patients with melioidosis. In mice, transgenic overexpression of EPCR aggravates outcome during Gram-negative pneumonia-derived sepsis caused by B. pseudomallei, while endogenous EPCR does not impact on the host response. These results add to a better understanding of the regulation of coagulation during severe (pneumosepsis.

  19. Mucositis and oral infections secondary to gram negative rods in patients with prolonged neutropenia

    Directory of Open Access Journals (Sweden)

    Mindy M. Sampson

    2017-01-01

    Full Text Available Patients with prolonged neutropenia are at risk for a variety of complications and infections including the development of mucositis and oral ulcers. The changes in oral flora during chemotherapy and its effects on the development of infections of the oral cavity have been studied with inconsistent results. However, there is evidence that supports the colonization of gram negative rods in patients undergoing chemotherapy. In this report, we present two leukemic patients who developed oral ulcers secondary to multi-drug resistant Pseudomonas aeruginosa. It is important to suspect multi-drug resistant gram negative rods in patients with prolonged neutropenia who develop gum infections despite appropriate antibiotic coverage.

  20. The structures of lipopolysaccharides from plant-associated gram-negative bacteria

    DEFF Research Database (Denmark)

    Molinaro, Antonio; Newman, Mari-Anne; Lanzetta, Rosa

    2009-01-01

    Gram-negative bacterial lipopolysaccharides (LPSs) have multiple roles in plant-microbe interactions. LPSs contribute to the low permeabilities of bacterial outer membranes, which act as barriers to protect bacteria from plant-derived antimicrobial substances. Conversely, perception of LPSs...... is an important prerequisite for any further understanding of the biological processes in plant-microbe interactions. Moreover, the LPSs from Gram-negative bacteria - especially those originating from plant-associated bacteria - are a great source of novel monosaccharides with unusual and occasionally astounding...

  1. Increased levels of specific leukocyte- and platelet-derived substances during normal anti-tetanus antibody synthesis in patients with inactive Crohn disease

    DEFF Research Database (Denmark)

    Nielsen, Hans Jørgen; Mortensen, T; Holten-Andersen, M

    2001-01-01

    , vascular endothelial growth factor (VEGF), tissue inhibitor of metalloproteinases-1 (TIMP-1), plasminogen activator inhibitor type-1 (PAI-1) and myeloperoxidase (MPO) were determined in serum or plasma obtained on the same days. RESULTS: After inoculation anti-tetanus antibody levels were equally raised...... immunization in patients with Crohn disease and the subsequent release of various inflammatory mediators and growth factors in blood. METHODS: Ten patients with inactive disease and no concurrent medication and 12 age-and gender-matched healthy volunteers with anti-tetanus antibody levels less than 0.1 IU...... range and IL-6, TNF-alpha, MPO and histamine levels were unchanged in patients and volunteers during the study period. The levels of VEGF, TIMP-1 and PAI-1 were unchanged in the healthy volunteers during the study period, but were significantly (P

  2. Lactoferricin B inhibits bacterial macromolecular synthesis in Escherichia coli and Bacillus subtilis.

    Science.gov (United States)

    Ulvatne, Hilde; Samuelsen, Ørjan; Haukland, Hanne H; Krämer, Manuela; Vorland, Lars H

    2004-08-15

    Most antimicrobial peptides have an amphipathic, cationic structure, and an effect on the cytoplasmic membrane of susceptible bacteria has been postulated as the main mode of action. Other mechanisms have been reported, including inhibition of cellular functions by binding to DNA, RNA and proteins, and the inhibition of DNA and/or protein synthesis. Lactoferricin B (Lfcin B), a cationic peptide derived from bovine lactoferrin, exerts slow inhibitory and bactericidal activity and does not lyse susceptible bacteria, indicating a possible intracellular target. In the present study incorporation of radioactive precursors into DNA, RNA and proteins was used to demonstrate effects of Lfcin B on macromolecular synthesis in bacteria. In Escherichia coli UC 6782, Lfcin B induces an initial increase in protein and RNA synthesis and a decrease in DNA synthesis. After 10 min, the DNA-synthesis increases while protein and RNA-synthesis decreases significantly. In Bacillus subtilis, however, all synthesis of macromolecules is inhibited for at least 20 min. After 20 min RNA-synthesis increases. The results presented here show that Lfcin B at concentrations not sufficient to kill bacterial cells inhibits incorporation of radioactive precursors into macromolecules in both Gram-positive and Gram-negative bacteria.

  3. Studies on chlorophyll and viable mutations in green gram (Vigna radiata L. Wilczek) II: Response to mutagen

    Energy Technology Data Exchange (ETDEWEB)

    Krishnaswami, S; Rathinam, M [Tamil Nadu Agricultural Univ., Coimbatore (India). Dept. of Agricultural Botany

    1980-09-01

    The frequency and spectrum of chlorophyll and viable mutations in relation to type and dose of mutagen and cluster progenies were studied in four green gram cultivars viz., Kopergaon, Pusa Baisakhi, L. 24/2 and Sel. 122 subjected to two levels of EMS and gamma irradiation, severally and in conjunction. While chlorophyll mutations did not vary with the mutagen dose, viable mutations exhibited a direct relationship. Combinations of the mutagens were more effective in mutation induction. While no difference was manifested between the cluster families in respect of chlorophyll mutations, progenies of the second cluster recorded less viable mutations than either the first or the third. Viridis and xanthoviridis among chlorophyll mutations, and those affecting plant duration and stature among viable were more predominant.

  4. The usefulness of changing focus during examination using Gram staining as initial diagnostic clue for infective tuberculosis.

    Science.gov (United States)

    Atsukawa, Yoshiko; Kawakami, Sayoko; Asahara, Miwa; Ishigaki, Shinobu; Tanaka, Takashi; Ono, Yasuo; Nishiya, Hajime; Fujisaki, Ryuichi; Koga, Ichiro; Ota, Yasuo; Miyazawa, Yukihisa

    2011-08-01

    Gram staining is a useful technique for detecting bacteria but is highly questionable in detecting Mycobacterium tuberculosis. Its detection generally requires special staining, such as Ziehl-Neelsen staining. We experienced three cases in which tuberculosis was first suggested by Gram staining of sputum or pus, confirmed by Ziehl-Neelsen staining, and diagnosed by polymerase chain reaction or culture. To find colorless tubercle bacilli in clinical samples with various organisms, varying the focus to slightly longer and shorter during study of the slides is indispensable. We present criteria for detecting infective pulmonary tuberculosis in Gram staining. First, in the ordinary focus, weakly stained, thin, gram-positive bacilli are found; second, with a slightly longer focus distance, the thin, cord-like, conspicuous gram-positive bacilli can be observed; and third, with a shorter focus distance, the gram-positive bacilli have changed into the brightened, colorless, or ghost ones. Four laboratory technologists each evaluated 20 Gram-stained samples after being lectured on the criteria, with no prior information about the sample. They accurately evaluated the presence of the bacilli in Gram-stained preparations in more than 90% of samples containing 3+ bacilli on Ziehl-Neelsen staining. Gram staining is available as an easy and rapid initial clue to recognize highly infective tuberculosis.

  5. Flavins mediate extracellular electron transfer in Gram-positive Bacillus megaterium strain LLD-1

    DEFF Research Database (Denmark)

    You, Le-Xing; Liu, Li-Dan; Xiao, Yong

    2018-01-01

    The extracellular electron transfer (EET) mechanism of an isolated Gram-positive Bacillus megaterium strain (LLD-1), identified by 16S rRNA gene sequencing and physiological analysis, was investigated in the present study. The electrochemical activity of strain LLD-1 was confirmed by electrochemi...

  6. The effect of mutagens on M1 population of black gram (Vigno ...

    African Journals Online (AJOL)

    Ramya

    2014-02-19

    Feb 19, 2014 ... This study was carried out with black gram (urdbean) variety TNAUCo(Bg)6 to determine the effects of gamma rays (150, 200, 250, 300 and 350 Gy) and ethyl methane sulphonate (10, 15, 20, 25, 30 mM). Data collected were on seed germination and survival, pollen and seed fertility, plant height, number of.

  7. The complete genome sequence of the Gram-positive bacterium Bacillus subtilis

    NARCIS (Netherlands)

    Kunst, F; Ogasawara, N; Moszer, [No Value; Albertini, AM; Alloni, G; Azevedo, [No Value; Bertero, MG; Bessieres, P; Bolotin, A; Borchert, S; Borriss, R; Boursier, L; Brans, A; Brignell, SC; Bron, S; Brouillet, S; Bruschi, CV; Caldwell, B; Capuano, [No Value; Carter, NM; Choi, SK; Codani, JJ; Connerton, IF; Cummings, NJ; Daniel, RA; Denizot, F; Devine, KM; Dusterhoft, A; Ehrlich, SD; Emmerson, PT; Entian, KD; Errington, J; Fabret, C; Ferrari, E; Foulger, D; Fujita, M; Fujita, Y; Fuma, S; Galizzi, A; Galleron, N; Ghim, SY; Glaser, P; Goffeau, A; Golightly, EJ; Grandi, G; Guiseppi, G; Guy, BJ; Haga, K; Haiech, J; Harwood, CR; Henaut, A; Hilbert, H; Holsappel, S; Hosono, S; Hullo, MF; Itaya, M; Jones, L; Joris, B; Karamata, D; Kasahara, Y; KlaerrBlanchard, M; Klein, C; Kobayashi, Y; Koetter, P; Koningstein, G; Krogh, S; Kumano, M; Kurita, K; Lapidus, A; Lardinois, S; Lauber, J; Lazarevic, [No Value; Lee, SM; Levine, A; Liu, H; Masuda, S; Mauel, C; Medigue, C; Medina, N; Mellado, RP; Mizuno, M; Moestl, D; Nakai, S; Noback, M; Noone, D; OReilly, M; Ogawa, K; Ogiwara, A; Oudega, B; Park, SH; Parro, [No Value; Pohl, TM; Portetelle, D; Porwollik, S; Prescott, AM; Presecan, E; Pujic, P; Purnelle, B; Rapoport, G; Rey, M; Reynolds, S; Rieger, M; Rivolta, C; Rocha, E; Roche, B; Rose, M; Sadaie, Y; Sato, T; Scanlan, E; Schleich, S; Schroeter, R; Scoffone, F; Sekiguchi, J; Sekowska, A; Seror, SJ; Serror, P; Shin, BS; Soldo, B; Sorokin, A; Tacconi, E; Takagi, T; Takahashi, H; Takemaru, K; Takeuchi, M; Tamakoshi, A; Tanaka, T; Terpstra, P; Tognoni, A; Tosato, [No Value; Uchiyama, S; Vandenbol, M; Vannier, F; Vassarotti, A; Viari, A; Wambutt, R; Wedler, E; Wedler, H; Weitzenegger, T; Winters, P; Wipat, A; Yamamoto, H; Yamane, K; Yasumoto, K; Yata, K; Yoshida, K; Yoshikawa, HF; Zumstein, E; Yoshikawa, H; Danchin, A

    1997-01-01

    Bacillus subtilis is the best-characterized member of the Gram-positive bacteria. Its genome of 4,214,810 base pairs comprises 4,100 protein-coding genes. Of these protein-coding genes, 53% are represented once, while a quarter of the genome corresponds to several gene families that have been

  8. Loss of outer membrane integrity in Gram-negative bacteria by silver ...

    Indian Academy of Sciences (India)

    plausible mechanism of bacterial cell disintegration ... New generation antimicrobial and smart drugs are the needs of the present era in fighting microbial ... charides (LPSs) in nature where the lipid portion acts ... sive release of LPS molecules and membrane proteins [10]. ... efficacy of antimicrobial action on Gram bacteria.

  9. Performance of Gram staining on blood cultures flagged negative by an automated blood culture system.

    Science.gov (United States)

    Peretz, A; Isakovich, N; Pastukh, N; Koifman, A; Glyatman, T; Brodsky, D

    2015-08-01

    Blood is one of the most important specimens sent to a microbiology laboratory for culture. Most blood cultures are incubated for 5-7 days, except in cases where there is a suspicion of infection caused by microorganisms that proliferate slowly, or infections expressed by a small number of bacteria in the bloodstream. Therefore, at the end of incubation, misidentification of positive cultures and false-negative results are a real possibility. The aim of this work was to perform a confirmation by Gram staining of the lack of any microorganisms in blood cultures that were identified as negative by the BACTEC™ FX system at the end of incubation. All bottles defined as negative by the BACTEC FX system were Gram-stained using an automatic device and inoculated on solid growth media. In our work, 15 cultures that were defined as negative by the BACTEC FX system at the end of the incubation were found to contain microorganisms when Gram-stained. The main characteristic of most bacteria and fungi growing in the culture bottles that were defined as negative was slow growth. This finding raises a problematic issue concerning the need to perform Gram staining of all blood cultures, which could overload the routine laboratory work, especially laboratories serving large medical centers and receiving a large number of blood cultures.

  10. In vitro susceptibility of gram-negative bacterial isolates to chlorhexidine gluconate.

    Science.gov (United States)

    Mengistu, Y; Erge, W; Bellete, B

    1999-05-01

    To investigate the susceptibility of clinical isolates of gram-negative bacteria to chlorhexidine gluconate. Prospective laboratory study. Tikur Anbessa Hospital, Addis Ababa, Ethiopia. Clinical specimens from 443 hospital patients. Significant number of gram negative bacteria were not inhibited by chlorhexidine gluconate (0.02-0.05%) used for antisepsis. Four hundred and forty three strains of gram-negative bacteria were isolated from Tikur Anbessa Hospital patients. Escherichia coli (31.6%) and Klebsiella pneumoniae (23%) were the most frequently isolated bacteria followed by Proteus species (13.3%), Pseudomonas species (9.2%), and Citrobacter species (6.1%). Each organism was tested to chlorhexidine gluconate (CHG), minimum inhibitory concentration (MIC) ranging from 0.0001% to 1%w/v. All Salmonella species and E. coli were inhibited by CHG, MIC or = 0.1%). Our results showed that a significant number of the gram-negative bacterial isolates were not inhibited by CHG at the concentration used for disinfection of wounds or instruments (MIC 0.02-0.05% w/v). It is therefore important to select appropriate concentration of this disinfectant and rationally use it for disinfection and hospital hygiene. Continuing follow up and surveillance is also needed to detect resistant bacteria to chlorhexidine or other disinfectants in time.

  11. Activation of toll-like receptors 2 and 4 by gram-negative periodontal bacteria

    NARCIS (Netherlands)

    Kikkert, R.; Laine, M. L.; Aarden, L. A.; van Winkelhoff, A. J.

    2007-01-01

    BACKGROUND/AIMS: Periodontitis is a chronic infectious disease associated with a gram-negative subgingival microflora. Bacterial components stimulate, among other receptors, Toll-like receptor (TLR) 2 and/or TLR4. Accumulating evidence indicates that both qualitatively and quantitatively distinct

  12. Anton Grams dem Gustav Friedrich Wilhelm Großmann: Mozart schreibe eine neue Oper

    Czech Academy of Sciences Publication Activity Database

    Jonášová, Milada

    2016-01-01

    Roč. 53, č. 1 (2016), s. 29-53 ISSN 0018-7003 R&D Projects: GA ČR GAP409/12/2563 Institutional support: RVO:68378076 Keywords : Mozart * 1786 * letter * Anton Grams * Gustav Friedrich Wilhelm Großmann Subject RIV: AL - Art, Architecture, Cultural Heritage

  13. Nodulation studies with induced mutants of black gram (Vigna mungo L.)

    International Nuclear Information System (INIS)

    Mahna, S.K.; Garg, Rekha; Parvateesam, M.

    1990-01-01

    Mutation breeding has been widely used to generate genetic variability in plants, but reports of mutations affecting the root system are less common. In the present work, black gram (Vigna mungo L. var T9), has been used for studies on the effect of induced mutations on nodulation patterns

  14. Tribolium castaneum defensins are primarily active against Gram-positive bacteria

    Czech Academy of Sciences Publication Activity Database

    Tonk, M.; Knorr, E.; Cabezas-Cruz, A.; Valdés, James J.; Kollewe, C.; Vilcinskas, A.

    2015-01-01

    Roč. 132, NOV 2015 (2015), s. 208-215 ISSN 0022-2011 R&D Projects: GA MŠk(CZ) EE2.3.30.0032 Institutional support: RVO:60077344 Keywords : Antimicrobial peptides * Defensin * Innate immunity * Insects * Tribolium castaneum * Gram-positive bacteria Subject RIV: EI - Biotechnology ; Bionics Impact factor: 2.198, year: 2015

  15. Caractérisation phénotypique des bacilles à gram négatif ...

    African Journals Online (AJOL)

    From March to June 2013, all strains of Gram-negative bacilli resistant to at least a third generation cephalosporin for Enterobacteriaceae, or to ceftazidim (for Pseudomonas spp) and/or to carbapenem for all species, were consecutively included in the study. For each strain, susceptibility to a large panel of antibiotics by the ...

  16. Uma visão geral da gramática funcional

    Directory of Open Access Journals (Sweden)

    Maria Helena de Moura Neves

    2001-02-01

    Full Text Available

    O trabalho apresenta uma visão geral do que vem sendo chamado funcionalismo em lingüística. Contrapõem-se os modelos formalista e funcionalista e examinam-se, em especial, as propostas de gramática funcional de C. S. Dik e de M. A. K. Halliday.

  17. Melting point gram-atomic volumes and enthalpies of atomization for liquid elements

    International Nuclear Information System (INIS)

    Lamoreaux, R.H.

    1976-01-01

    Values of the gram-atomic volumes and enthalpies of atomization to the monatomic ideal gas state for liquid elements at their melting points are collected to facilitate predictions of the behavior of mixed systems. Estimated values are given for experimentally undetermined quantities

  18. Antibiotic-Resistant Gram Negative Bacilli in Meals Delivered at a General Hospital, Italy

    Directory of Open Access Journals (Sweden)

    Maria Rosa Anna Plano

    2009-01-01

    Full Text Available This study aimed at detecting the presence of antibiotic-resistant Gram-negatives in samples of meals delivered at the University General Hospital of Palermo, Italy. Antibiotic resistant Gram negatives were isolated in July—September 2007 ffrom cold dishes and food contact surfaces and utensils. Bacterial strains were submitted to susceptibility test and subtyped by random amplification of polymorphic DNA (RAPD. Forty-six of 55 (83.6% food samples and 14 of 17 (82.3% environmental swabs were culture positive for Gram negative bacilli resistant to at least one group of antibacterial drugs. A total of 134 antibiotic resistant strains, 51 fermenters and 83 non-fermenters, were recovered. Fermenters and non-fermenters showed frequencies as high as 97.8% of resistance to two or more groups of antibiotics and non fermenters were 28.9% resistant to more than three groups. Molecular typing detected 34 different profiles among the fermenters and 68 among the non-fermenters. Antibiotic resistance was very common among both fermenters and non-fermenters. However, the wide heterogeneity of RAPD patterns seems to support a prominent role of cross-contamination rather than a clonal expansion of a few resistant isolates. A contribution of commensal Gram negatives colonizing foods to a common bacterial resistance pool should not been overlooked.

  19. Dual beta-lactam therapy for serious Gram-negative infections: is it time to revisit?

    Science.gov (United States)

    Rahme, Christine; Butterfield, Jill M; Nicasio, Anthony M; Lodise, Thomas P

    2014-12-01

    We are rapidly approaching a crisis in antibiotic resistance, particularly among Gram-negative pathogens. This, coupled with the slow development of novel antimicrobial agents, underscores the exigency of redeploying existing antimicrobial agents in innovative ways. One therapeutic approach that was heavily studied in the 1980s but abandoned over time is dual beta-lactam therapy. This article reviews the evidence for combination beta-lactam therapy. Overall, in vitro, animal and clinical data are positive and suggest that beta-lactam combinations produce a synergistic effect against Gram-negative pathogens that rivals that of beta-lactam-aminoglycoside or beta-lactam-fluoroquinolone combination therapy. Although the precise mechanism of improved activity is not completely understood, it is likely attributable to an enhanced affinity to the diverse penicillin-binding proteins found among Gram negatives. The collective data indicate that dual beta-lactam therapy should be revisited for serious Gram-negative infections, especially in light of the near availability of potent beta-lactamase inhibitors, which neutralize the effect of problematic beta-lactamases. Copyright © 2014 Elsevier Inc. All rights reserved.

  20. Antibiotic-resistant gram negative bacilli in meals delivered at a general hospital, Italy.

    Science.gov (United States)

    Plano, Maria Rosa Anna; Di Noto, Anna Maria; Firenze, Alberto; Sciortino, Sonia; Mammina, Caterina

    2009-01-01

    This study aimed at detecting the presence of antibiotic-resistant Gram-negatives in samples of meals delivered at the University General Hospital of Palermo, Italy. Antibiotic resistant Gram negatives were isolated in July-September 2007 ffrom cold dishes and food contact surfaces and utensils. Bacterial strains were submitted to susceptibility test and subtyped by random amplification of polymorphic DNA (RAPD). Forty-six of 55 (83.6%) food samples and 14 of 17 (82.3%) environmental swabs were culture positive for Gram negative bacilli resistant to at least one group of antibacterial drugs. A total of 134 antibiotic resistant strains, 51 fermenters and 83 non-fermenters, were recovered. Fermenters and non-fermenters showed frequencies as high as 97.8% of resistance to two or more groups of antibiotics and non fermenters were 28.9% resistant to more than three groups. Molecular typing detected 34 different profiles among the fermenters and 68 among the non-fermenters. Antibiotic resistance was very common among both fermenters and non-fermenters. However, the wide heterogeneity of RAPD patterns seems to support a prominent role of cross-contamination rather than a clonal expansion of a few resistant isolates. A contribution of commensal Gram negatives colonizing foods to a common bacterial resistance pool should not been overlooked.

  1. La «Gramàtica Valenciana» de Manuel Sanchis Guarner

    Directory of Open Access Journals (Sweden)

    Antoni Ferrando

    2015-10-01

    Full Text Available This article studies Sanchis Guarner's Gramàtica Valenciana, trying to assess its relevant contribution, referring not only to the author's ideology and established goal, but also to its historical context and to its Catalan as well as Valencian precedents, like Fabra on one side, and Fullana, Giner and Salvador, on the other.

  2. Prevalence of AmpC β-lactamase among Gram-negative bacteria ...

    African Journals Online (AJOL)

    Purpose: Infections caused by AmpC-positive bacteria results in high patient morbidity and mortality making their detection clinically important as they cannot be detected in routine susceptibility testing. This study aim to determine the prevalence of AmpC β-lactamase among Gram negative bacteria recovered from clinical ...

  3. Antimicrobial Resistance in Gram-Negative Rods Causing Bacteremia in Hematopoietic Stem Cell Transplant Recipients

    DEFF Research Database (Denmark)

    Averbuch, Diana; Tridello, Gloria; Hoek, Jennifer

    2017-01-01

    Background: This intercontinental study aimed to study gram-negative rod (GNR) resistance in hematopoietic stem cell transplantation (HSCT). Methods: GNR bacteremias occurring during 6 months post-HSCT (February 2014-May 2015) were prospectively collected, and analyzed for rates and risk factors...

  4. Diversity of pigmented Gram-positive bacteria associated with marine macroalgae from Antarctica.

    Science.gov (United States)

    Leiva, Sergio; Alvarado, Pamela; Huang, Ying; Wang, Jian; Garrido, Ignacio

    2015-12-01

    Little is known about the diversity and roles of Gram-positive and pigmented bacteria in Antarctic environments, especially those associated with marine macroorganisms. This work is the first study about the diversity and antimicrobial activity of culturable pigmented Gram-positive bacteria associated with marine Antarctic macroalgae. A total of 31 pigmented Gram-positive strains were isolated from the surface of six species of macroalgae collected in the King George Island, South Shetland Islands. On the basis of 16S rRNA gene sequence similarities ≥99%, 18 phylotypes were defined, which were clustered into 11 genera of Actinobacteria (Agrococcus, Arthrobacter, Brachybacterium, Citricoccus, Kocuria, Labedella, Microbacterium, Micrococcus, Rhodococcus, Salinibacterium and Sanguibacter) and one genus of the Firmicutes (Staphylococcus). It was found that five isolates displayed antimicrobial activity against a set of macroalgae-associated bacteria. The active isolates were phylogenetically related to Agrococcus baldri, Brachybacterium rhamnosum, Citricoccus zhacaiensis and Kocuria palustris. The results indicate that a diverse community of pigmented Gram-positive bacteria is associated with Antartic macroalgae and suggest its potential as a promising source of antimicrobial and pigmented natural compounds. © FEMS 2015. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  5. Development and quality evaluation of hypoallergic complementary foods from rice incorporated with sprouted green gram flour

    Directory of Open Access Journals (Sweden)

    Rafiya Bazaz

    2016-12-01

    Full Text Available Rice flour and green gram flour (sprouted as well as unsprouted were blended in different proportions with apple pulp, sugar, milk and water for formulation of 12 hypoallergic diets. The formulations were studied for physico-chemical properties, antinutrient content (phytate and oxalate and in vitro protein digestibility. Blending and sprouting significantly affected all the studied parameters. Sprouting significantly (p ≤ 0.05 improved protein content and in vitro protein digestibility, while carbohydrate content and antinutrients decreased significantly. Nutrition profile of water-based diets met RDA guidelines only after addition of sprouted green gram flour and were comparable to control (commercial weaning food. Water-based formulation showed lower sensory score than milk-based diets; however, addition of sprouted green gram flour significantly (p ≤ 0.05 improved their overall acceptability. It could be concluded that by incorporating sprouted green gram flour, milk could be replaced with water for production of hypoallergic weaning foods without affecting the nutritional and sensory attributes of formulations and thereby making the production more economical, especially for underdeveloped countries.

  6. Non-oral gram-negative facultative rods in chronic periodontitis microbiota

    NARCIS (Netherlands)

    van Winkelhoff, Arie J; Rurenga, Patrick; Wekema-Mulder, Gepke J; Singadji, Zadnach; Rams, Thomas E

    OBJECTIVE: The subgingival prevalence of gram-negative facultative rods not usually inhabiting or indigenous to the oral cavity (non-oral GNFR), as well as selected periodontal bacterial pathogens, were evaluated by culture in untreated and treated chronic periodontitis patients. METHODS:

  7. Increased levels of specific leukocyte- and platelet-derived substances during normal anti-tetanus antibody synthesis in patients with inactive Crohn disease

    DEFF Research Database (Denmark)

    Nielsen, Hans Jørgen; Mortensen, T; Holten-Andersen, M

    2001-01-01

    /ml were inoculated with 1 ml (6 Lf units) of tetanus toxoid vaccine. The anti-tetanus antibody levels were determined in serum obtained before inoculation and after 7, 14 and 28 days, respectively. C-reactive protein (CRP), interleukin-6 (IL-6), tumour necrosis factor-alpha (TNF-alpha), histamine......, vascular endothelial growth factor (VEGF), tissue inhibitor of metalloproteinases-1 (TIMP-1), plasminogen activator inhibitor type-1 (PAI-1) and myeloperoxidase (MPO) were determined in serum or plasma obtained on the same days. RESULTS: After inoculation anti-tetanus antibody levels were equally raised...

  8. Gram-Scale Synthesis and Highly Regioselective Bromination of 1,1,9,9-Tetramethyl[9](2,11)teropyrenophane

    Czech Academy of Sciences Publication Activity Database

    Unikela, K. S.; Roemmele, T. L.; Houska, Václav; McGrath, K. E.; Tobin, D. M.; Dawe, L. N.; Boeré, R. T.; Bodwell, G. J.

    2018-01-01

    Roč. 57, č. 6 (2018), s. 1707-1711 ISSN 1433-7851 Institutional support: RVO:61388963 Keywords : aromaticity * bromination * cyclophanes * EPR spectroscopy * structure elucidation Subject RIV: CC - Organic Chemistry OBOR OECD: Organic chemistry Impact factor: 11.994, year: 2016

  9. Gram-scale solution-phase synthesis of selective sodium bicarbonate Co-transport Inhibitor S0859

    DEFF Research Database (Denmark)

    Larsen, Ann Møller; Krogsgaard-Larsen, Niels; Lauritzen, Gitte

    2012-01-01

    Na+-coupled HCO3- transporters (NBCs) mediate the transport of bicarbonate ions across cell membranes and are thus ubiquitous regulators of intracellular pH. NBC dysregulation is associated with a range of diseases; for instance, NBCn1 is strongly up-regulated in a model of ErbB2-dependent breast...

  10. [Phytosterols: another way to reduce LDL cholesterol levels].

    Science.gov (United States)

    Bitzur, Rafael; Cohen, Hofit; Kamari, Yehuda; Harats, Dror

    2013-12-01

    Phytosterols are sterols found naturally in various oils from plants. Phytosterols compete with cholesterol for a place in the mixed micelles, needed for cholesterol absorption by the small intestine. As a result, cholesterol absorption, either from food or from bile salts is lowered by about 50%, leading to a towering of about 10% of blood cholesterol level, despite an increase in hepatic cholesterol synthesis. This reduction is achieved when phytosterols are given both as monotherapy, and in addition to statin therapy. The average Western diet contains about 400-800 mg of phytosterols per day, while the dose needed for lowering the blood cholesterol level is about 2-3 grams per day. Therefore, for the purpose of reducing blood cholesterol, they should be given either as phytosterol-enriched food or as supplements. The reduction in the level of LDL-choLesterol achieved with phytosterols may reduce the risk of coronary disease by about 25%. Hence, the American Heart Association recommended the consumption of phytosterols, as part of a balanced diet, for towering blood cholesterol levels.

  11. Effectiveness of oral antibiotics for definitive therapy of Gram-negative bloodstream infections.

    Science.gov (United States)

    Kutob, Leila F; Justo, Julie Ann; Bookstaver, P Brandon; Kohn, Joseph; Albrecht, Helmut; Al-Hasan, Majdi N

    2016-11-01

    There is paucity of data evaluating intravenous-to-oral antibiotic switch options for Gram-negative bloodstream infections (BSIs). This retrospective cohort study examined the effectiveness of oral antibiotics for definitive treatment of Gram-negative BSI. Patients with Gram-negative BSI hospitalised for antibiotics were included in this study. The cohort was stratified into three groups based on bioavailability of oral antibiotics prescribed (high, ≥95%; moderate, 75-94%; and low, antibiotics were prescribed to 106, 179 and 77 patients, respectively, for definitive therapy of Gram-negative BSI. Mean patient age was 63 years, 217 (59.9%) were women and 254 (70.2%) had a urinary source of infection. Treatment failure rates were 2%, 12% and 14% in patients receiving oral antibiotics with high, moderate and low bioavailability, respectively (P = 0.02). Risk of treatment failure in the multivariate Cox model was higher in patients receiving antibiotics with moderate [adjusted hazard ratio (aHR) = 5.9, 95% CI 1.6-38.5; P = 0.005] and low bioavailability (aHR = 7.7, 95% CI 1.9-51.5; P = 0.003) compared with those receiving oral antimicrobial agents with high bioavailability. These data demonstrate the effectiveness of oral antibiotics with high bioavailability for definitive therapy of Gram-negative BSI. Risk of treatment failure increases as bioavailability of the oral regimen declines. Copyright © 2016 Elsevier B.V. and International Society of Chemotherapy. All rights reserved.

  12. Combinatorial events of insertion sequences and ICE in Gram-negative bacteria.

    Science.gov (United States)

    Toleman, Mark A; Walsh, Timothy R

    2011-09-01

    The emergence of antibiotic and antimicrobial resistance in Gram-negative bacteria is incremental and linked to genetic elements that function in a so-called 'one-ended transposition' manner, including ISEcp1, ISCR elements and Tn3-like transposons. The power of these elements lies in their inability to consistently recognize one of their own terminal sequences, while recognizing more genetically distant surrogate sequences. This has the effect of mobilizing the DNA sequence found adjacent to their initial location. In general, resistance in Gram-negatives is closely linked to a few one-off events. These include the capture of the class 1 integron by a Tn5090-like transposon; the formation of the 3' conserved segment (3'-CS); and the fusion of the ISCR1 element to the 3'-CS. The structures formed by these rare events have been massively amplified and disseminated in Gram-negative bacteria, but hitherto, are rarely found in Gram-positives. Such events dominate current resistance gene acquisition and are instrumental in the construction of large resistance gene islands on chromosomes and plasmids. Similar combinatorial events appear to have occurred between conjugative plasmids and phages constructing hybrid elements called integrative and conjugative elements or conjugative transposons. These elements are beginning to be closely linked to some of the more powerful resistance mechanisms such as the extended spectrum β-lactamases, metallo- and AmpC type β-lactamases. Antibiotic resistance in Gram-negative bacteria is dominated by unusual combinatorial mistakes of Insertion sequences and gene fusions which have been selected and amplified by antibiotic pressure enabling the formation of extended resistance islands. © 2011 Federation of European Microbiological Societies. Published by Blackwell Publishing Ltd. All rights reserved.

  13. Common TNF-alpha, IL-1 beta, PAI-1, uPA, CD14 and TLR4 polymorphisms are not associated with disease severity or outcome from Gram negative sepsis

    DEFF Research Database (Denmark)

    Jessen, Kirstine Marie; Lindboe, Sarah Bjerre; Petersen, Anncatrine Luisa

    2007-01-01

    consecutive adult patients with culture proven Gram negative bacteremia admitted to a Danish hospital between 2000 and 2002. Analysis for commonly described SNPs of tumor necrosis-alpha, (TNF-alpha), interleukin-1 beta (IL-1 beta), plasminogen activator-1 (PAI-1), urokinase plasminogen activator (uPA), CD14...... hazard regression analysis, increasing age, polymicrobial infection and haemoglobin levels were associated with in-hospital mortality. CONCLUSION: We did not find any association between TNF-alpha, IL-1 beta, PAI-1, uPA, CD14 and TLR4 polymorphisms and outcome of Gram negative sepsis. Other host factors...... appear to be more important than the genotypes studied here in determining the severity and outcome of Gram negative sepsis....

  14. Gram Stain

    Science.gov (United States)

    ... Wu, A. (© 2006). Tietz Clinical Guide to Laboratory Tests, 4th Edition: Saunders Elsevier, St. Louis, MO. Pp 1564-1565. Forbes, B. et. al. (© 2007). Bailey & Scott's Diagnostic Microbiology, 12th Edition: Mosby Elsevier Press, St. Louis, MO. ...

  15. Signaling Pathways Related to Protein Synthesis and Amino Acid Concentration in Pig Skeletal Muscles Depend on the Dietary Protein Level, Genotype and Developmental Stages.

    Science.gov (United States)

    Liu, Yingying; Li, Fengna; Kong, Xiangfeng; Tan, Bie; Li, Yinghui; Duan, Yehui; Blachier, François; Hu, Chien-An A; Yin, Yulong

    2015-01-01

    Muscle growth is regulated by the homeostatic balance of the biosynthesis and degradation of muscle proteins. To elucidate the molecular interactions among diet, pig genotype, and physiological stage, we examined the effect of dietary protein concentration, pig genotype, and physiological stages on amino acid (AA) pools, protein deposition, and related signaling pathways in different types of skeletal muscles. The study used 48 Landrace pigs and 48 pure-bred Bama mini-pigs assigned to each of 2 dietary treatments: lower/GB (Chinese conventional diet)- or higher/NRC (National Research Council)-protein diet. Diets were fed from 5 weeks of age to respective market weights of each genotype. Samples of biceps femoris muscle (BFM, type I) and longissimus dorsi muscle (LDM, type II) were collected at nursery, growing, and finishing phases according to the physiological stage of each genotype, to determine the AA concentrations, mRNA levels for growth-related genes in muscles, and protein abundances of mechanistic target of rapamycin (mTOR) signaling pathway. Our data showed that the concentrations of most AAs in LDM and BFM of pigs increased (Prelated AA, including Met, Phe, Tyr, Pro, and Ser, compared with Landrace pigs. The mRNA levels for myogenic determining factor, myogenin, myocyte-specific enhancer binding factor 2 A, and myostatin of Bama mini-pigs were higher (P<0.05) than those of Landrace pigs, while total and phosphorylated protein levels for protein kinase B, mTOR, and p70 ribosomal protein S6 kinases (p70S6K), and ratios of p-mTOR/mTOR, p-AKT/AKT, and p-p70S6K/p70S6K were lower (P<0.05). There was a significant pig genotype-dependent effect of dietary protein on the levels for mTOR and p70S6K. When compared with the higher protein-NRC diet, the lower protein-GB diet increased (P<0.05) the levels for mTOR and p70S6K in Bama mini-pigs, but repressed (P<0.05) the level for p70S6K in Landrace pigs. The higher protein-NRC diet increased ratio of p-mTOR/mTOR in

  16. Gram-scale production of B, N co-doped graphene-like carbon for high performance supercapacitor electrodes

    Science.gov (United States)

    Chen, Zhuo; Hou, Liqiang; Cao, Yan; Tang, Yushu; Li, Yongfeng

    2018-03-01

    Boron and nitrogen co-doped graphene-like carbon (BNC) with a gram scale was synthesized via a two-step method including a ball-milling process and a calcination process and used as electrode materials for supercapacitors. High surface area and abundant active sites of graphene-like carbon were created by the ball-milling process. Interestingly, the nitrogen atoms are doped in carbon matrix without any other N sources except for air. The textual and chemical properties can be easily tuned by changing the calcination temperature, and at 900 oC the BNC with a high surface area (802.35 m2/g), a high boron content (2.19 at%), a hierarchical pore size distribution and a relatively high graphitic degree was obtained. It shows an excellent performance of high specific capacitance retention about 78.2% at high current density (199 F/g at 100 A/g) of the initial capacitance (254 F/g at 0.25 A/g) and good cycling stability (90% capacitance retention over 1000 cycles at 100 A/g) measured in a three-electrode system. Furthermore, in a two-electrode system, a specific capacitance of 225 F/g at 0.25 A/g and a good cycling stability (93% capacitance retention over 20,000 cycles at 25 A/g) were achieved by using BNC as electrodes. The strategy of synthesis is facile and effective to fabricate multi-doped graphene-like carbon for promising candidates as electrode materials in supercapacitors.

  17. Inactivation dynamics of 222 nm krypton-chlorine excilamp irradiation on Gram-positive and Gram-negative foodborne pathogenic bacteria.

    Science.gov (United States)

    Kang, Jun-Won; Kim, Sang-Soon; Kang, Dong-Hyun

    2018-07-01

    The object of this study was to elucidate the bactericidal mechanism of a 222 nm Krypton Chlorine (KrCl) excilamp compared with that of a 254 nm Low Pressure mercury (LP Hg) lamp. The KrCl excilamp had higher bactericidal capacity against Gram-positive pathogenic bacteria (Staphylococcus aureus and L. monocytogenes) and Gram-negative pathogenic bacteria (S. Typhimurium and E. coli O157:H7) than did the LP Hg lamp when cell suspensions in PBS were irradiated with each type of UV lamp. It was found out that the KrCl excilamp induced cell membrane damage as a form of depolarization. From the study of respiratory chain dehydrogenase activity and the lipid peroxidation assay, it was revealed that cell membrane damage was attributed to inactivation of enzymes related to generation of membrane potential and occurrence of lipid peroxidation. Direct absorption of UV radiation which led to photoreaction through formation of an excited state was one of the causes inducing cell damage. Additionally, generation of ROS and thus occurrence of secondary damage can be another cause. The LP Hg lamp only induced damage to DNA but not to other components such as lipids or proteins. This difference was derived from differences of UV radiation absorption by cellular materials. Copyright © 2018 Elsevier Ltd. All rights reserved.

  18. Synergistic effect of Carum copticum and Mentha piperita essential oils with ciprofloxacin, vancomycin, and gentamicin on Gram-negative and Gram-positive bacteria

    Science.gov (United States)

    Talei, Gholam-Reza; Mohammadi, Mohsen; Bahmani, Mahmoud; Kopaei, Mahmoud Rafieian

    2017-01-01

    Background: Infectious diseases have always been an important health issue in human communities. In the recent years, much research has been conducted on antimicrobial effects of nature-based compounds because of increased prevalence of antibiotic resistance. The present study was conducted to investigate synergistic effect of Carum copticum and Mentha piperita essential oils with ciprofloxacin, vancomycin, and gentamicin on Gram-negative and Gram-positive bacteria. Materials and Methods: In this experimental study, the synergistic effects of C. copticum and M. piperita essential oils with antibiotics on Staphylococcus aureus (ATCC 25923), Enterococcus faecalis (ATCC 29212), Escherichia coli (ATCC 8739), Pseudomonas aeruginosa (ATCC 9027), Staphylococcus epidermidis (ATCC 14990), and Listeria monocytogenes (ATCC 7644) were studied according to broth microdilution and the MIC and fractional inhibitory concentration (FIC) of these two essential oils determined. Results: C. copticum essential oil at 30 μg/ml could inhibit S. aureus, and in combination with vancomycin, decreased MIC from 0.5 to 0.12 μg/ml. Moreover, the FIC was derived 0.24 μg/ml which represents a potent synergistic effect with vancomycin against S. aureus growth. C. copticum essential oil alone or combined with other antibiotics is effective in treating bacterial infections. Conclusions: In addition, C. copticum essential oil can strengthen the activities of certain antibiotics, which makes it possible to use this essential oil, especially in drug resistance or to lower dosage or toxicity of the drugs. PMID:28929050

  19. Industrial scale gene synthesis.

    Science.gov (United States)

    Notka, Frank; Liss, Michael; Wagner, Ralf

    2011-01-01

    The most recent developments in the area of deep DNA sequencing and downstream quantitative and functional analysis are rapidly adding a new dimension to understanding biochemical pathways and metabolic interdependencies. These increasing insights pave the way to designing new strategies that address public needs, including environmental applications and therapeutic inventions, or novel cell factories for sustainable and reconcilable energy or chemicals sources. Adding yet another level is building upon nonnaturally occurring networks and pathways. Recent developments in synthetic biology have created economic and reliable options for designing and synthesizing genes, operons, and eventually complete genomes. Meanwhile, high-throughput design and synthesis of extremely comprehensive DNA sequences have evolved into an enabling technology already indispensable in various life science sectors today. Here, we describe the industrial perspective of modern gene synthesis and its relationship with synthetic biology. Gene synthesis contributed significantly to the emergence of synthetic biology by not only providing the genetic material in high quality and quantity but also enabling its assembly, according to engineering design principles, in a standardized format. Synthetic biology on the other hand, added the need for assembling complex circuits and large complexes, thus fostering the development of appropriate methods and expanding the scope of applications. Synthetic biology has also stimulated interdisciplinary collaboration as well as integration of the broader public by addressing socioeconomic, philosophical, ethical, political, and legal opportunities and concerns. The demand-driven technological achievements of gene synthesis and the implemented processes are exemplified by an industrial setting of large-scale gene synthesis, describing production from order to delivery. Copyright © 2011 Elsevier Inc. All rights reserved.

  20. Signaling Pathways Related to Protein Synthesis and Amino Acid Concentration in Pig Skeletal Muscles Depend on the Dietary Protein Level, Genotype and Developmental Stages.

    Directory of Open Access Journals (Sweden)

    Yingying Liu

    Full Text Available Muscle growth is regulated by the homeostatic balance of the biosynthesis and degradation of muscle proteins. To elucidate the molecular interactions among diet, pig genotype, and physiological stage, we examined the effect of dietary protein concentration, pig genotype, and physiological stages on amino acid (AA pools, protein deposition, and related signaling pathways in different types of skeletal muscles. The study used 48 Landrace pigs and 48 pure-bred Bama mini-pigs assigned to each of 2 dietary treatments: lower/GB (Chinese conventional diet- or higher/NRC (National Research Council-protein diet. Diets were fed from 5 weeks of age to respective market weights of each genotype. Samples of biceps femoris muscle (BFM, type I and longissimus dorsi muscle (LDM, type II were collected at nursery, growing, and finishing phases according to the physiological stage of each genotype, to determine the AA concentrations, mRNA levels for growth-related genes in muscles, and protein abundances of mechanistic target of rapamycin (mTOR signaling pathway. Our data showed that the concentrations of most AAs in LDM and BFM of pigs increased (P<0.05 gradually with increasing age. Bama mini-pigs had generally higher (P<0.05 muscle concentrations of flavor-related AA, including Met, Phe, Tyr, Pro, and Ser, compared with Landrace pigs. The mRNA levels for myogenic determining factor, myogenin, myocyte-specific enhancer binding factor 2 A, and myostatin of Bama mini-pigs were higher (P<0.05 than those of Landrace pigs, while total and phosphorylated protein levels for protein kinase B, mTOR, and p70 ribosomal protein S6 kinases (p70S6K, and ratios of p-mTOR/mTOR, p-AKT/AKT, and p-p70S6K/p70S6K were lower (P<0.05. There was a significant pig genotype-dependent effect of dietary protein on the levels for mTOR and p70S6K. When compared with the higher protein-NRC diet, the lower protein-GB diet increased (P<0.05 the levels for mTOR and p70S6K in Bama mini-pigs, but