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Sample records for bloodstream form strain

  1. Surface electrical charge of bloodstream trypomastigotes of Trypanosoma cruzi strains.

    Science.gov (United States)

    de Sousa, M A

    1983-01-01

    Bloodstream trypomastigotes of some Trypanosoma cruzi strains were processed through DEAE-cellulose columns under standardized conditions. The results obtained suggest mainly that these strains present different surface charges, that there are subpopulations of bloodstream trypomastigotes as regards electrical charges and that the broad forms are less negative than the slender ones. PMID:6443631

  2. Surface electrical charge of bloodstream trypomastigotes of Trypanosoma cruzi strains

    OpenAIRE

    Maria Auxiliadora de Sousa

    1983-01-01

    Bloodstream trypomastigotes of some Trypanosoma cruzi strains were processed through DEAE-cellulose columns under standardized conditions. The results obtained suggest mainly that these strains present different surface charges, that there are subpopulations of bloodstream trypomastigotes as regards electrical charges and that the broad forms are less negative than the slender ones.Tripomastigotas sanguíneos de algumas cepas de Trypanosoma cruzi foram processadas em colunas de DEAE-celulose s...

  3. Surface electrical charge of bloodstream trypomastigotes of Trypanosoma cruzi strains

    Directory of Open Access Journals (Sweden)

    Maria Auxiliadora de Sousa

    1983-12-01

    Full Text Available Bloodstream trypomastigotes of some Trypanosoma cruzi strains were processed through DEAE-cellulose columns under standardized conditions. The results obtained suggest mainly that these strains present different surface charges, that there are subpopulations of bloodstream trypomastigotes as regards electrical charges and that the broad forms are less negative than the slender ones.Tripomastigotas sanguíneos de algumas cepas de Trypanosoma cruzi foram processadas em colunas de DEAE-celulose sob condições padronizadas. Os resultados obtidos sugerem principalmente que estas cepas possuem cargas superficiais diferentes, que em relação a este aspecto existem subpopulações de tripomastigotas e que as formas largas são menos negativas do que as finas.

  4. Trypanin, a component of the flagellar Dynein regulatory complex, is essential in bloodstream form African trypanosomes.

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    Katherine S Ralston

    2006-09-01

    Full Text Available The Trypanosoma brucei flagellum is a multifunctional organelle with critical roles in motility, cellular morphogenesis, and cell division. Although motility is thought to be important throughout the trypanosome lifecycle, most studies of flagellum structure and function have been restricted to the procyclic lifecycle stage, and our knowledge of the bloodstream form flagellum is limited. We have previously shown that trypanin functions as part of a flagellar dynein regulatory system that transmits regulatory signals from the central pair apparatus and radial spokes to axonemal dyneins. Here we investigate the requirement for this dynein regulatory system in bloodstream form trypanosomes. We demonstrate that trypanin is localized to the flagellum of bloodstream form trypanosomes, in a pattern identical to that seen in procyclic cells. Surprisingly, trypanin RNA interference is lethal in the bloodstream form. These knockdown mutants fail to initiate cytokinesis, but undergo multiple rounds of organelle replication, accumulating multiple flagella, nuclei, kinetoplasts, mitochondria, and flagellum attachment zone structures. These findings suggest that normal flagellar beat is essential in bloodstream form trypanosomes and underscore the emerging concept that there is a dichotomy between trypanosome lifecycle stages with respect to factors that contribute to cell division and cell morphogenesis. This is the first time that a defined dynein regulatory complex has been shown to be essential in any organism and implicates the dynein regulatory complex and other enzymatic regulators of flagellar motility as candidate drug targets for the treatment of African sleeping sickness.

  5. Unfolded Protein Response Pathways in Bloodstream-Form Trypanosoma brucei?

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    Tiengwe, Calvin; Brown, Abigail E N A; Bangs, James D

    2015-11-01

    The unfolded protein response (UPR) is a stress mechanism to cope with misfolded proteins in the early secretory pathway, the hallmark being transcriptional upregulation of endoplasmic reticulum (ER) molecular chaperones such as BiP and protein disulfide isomerase. Despite the lack of transcriptional regulation and the absence of the classical UPR machinery, African trypanosomes apparently respond to persistent ER stress by a UPR-like response, including upregulation of BiP, and a related spliced leader silencing (SLS) response whereby SL RNA transcription is shut down. Initially observed by knockdown of the secretory protein translocation machinery, both responses are also induced by chemical agents known to elicit UPR in mammalian cells (H. Goldshmidt, D. Matas, A. Kabi, A. Carmi, R. Hope, S. Michaeli, PLoS Pathog 6:e1000731, 2010, http://dx.doi.org/10.1371/journal.ppat.1000731). As these findings were generated primarily in procyclic-stage trypanosomes, we have investigated both responses in pathogenic bloodstream-stage parasites. RNA interference (RNAi) silencing of the core translocon subunit Trypanosoma brucei Sec61α (TbSec61α) failed to induce either response. Interestingly, cell growth halted within 16 h of silencing, but sufficient TbSec61α remained to allow full competence for translocation of nascent secretory proteins for up to 24 h, indicating that replication is finely coupled with the capacity to synthesize and transport secretory cargo. Tunicamycin and thapsigargin at concentrations compatible with short-term (4 h) and long-term (24 h) viability also failed to induce any of the indicators of UPR-like or SLS responses. Dithiothreitol (DTT) was lethal at all concentrations tested. These results indicate that UPR-like and SLS responses to persistent ER stress do not occur in bloodstream-stage trypanosomes. PMID:26318397

  6. Impact of the introduction of an automated microbiologic system on the clinical outcomes of bloodstream infections caused by Enterobacteriaceae strains

    OpenAIRE

    Luciana Azevedo Callefi; Eduardo Alexandrino Servolo Medeiros; Guilherme Henrique Campos Furtado

    2013-01-01

    INTRODUCTION: Enterobacteriaceae strains are a leading cause of bloodstream infections (BSI). The aim of this study is to assess differences in clinical outcomes of patients with BSI caused by Enterobacteriaceae strains before and after introduction of an automated microbiologic system by the microbiology laboratory. METHODS: We conducted a retrospective cohort study aimed to evaluate the impact of the introduction of an automated microbiologic system (Phoenix(tm)...

  7. KREX2 is not essential for either procyclic or bloodstream form Trypanosoma brucei.

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    Jason Carnes

    Full Text Available BACKGROUND: Most mitochondrial mRNAs in Trypanosoma brucei require RNA editing for maturation and translation. The edited RNAs primarily encode proteins of the oxidative phosphorylation system. These parasites undergo extensive changes in energy metabolism between the insect and bloodstream stages which are mirrored by alterations in RNA editing. Two U-specific exonucleases, KREX1 and KREX2, are both present in protein complexes (editosomes that catalyze RNA editing but the relative roles of each protein are not known. METHODOLOGY/PRINCIPAL FINDINGS: The requirement for KREX2 for RNA editing in vivo was assessed in both procyclic (insect and bloodstream form parasites by methods that use homologous recombination for gene elimination. These studies resulted in null mutant cells in which both alleles were eliminated. The viability of these cells demonstrates that KREX2 is not essential in either life cycle stage, despite certain defects in RNA editing in vivo. Furthermore, editosomes isolated from KREX2 null cells require KREX1 for in vitro U-specific exonuclease activity. CONCLUSIONS: KREX2 is a U-specific exonuclease that is dispensable for RNA editing in vivo in T. brucei BFs and PFs. This result suggests that the U deletion activity, which is required for RNA editing, is primarily mediated in vivo by KREX1 which is normally found associated with only one type of editosome. The retention of the KREX2 gene implies a non-essential role or a role that is essential in other life cycle stages or conditions.

  8. JBP2, a SWI2/SNF2-like protein, regulates de novo telomeric DNA glycosylation in bloodstream form Trypanosoma brucei.

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    Kieft, Rudo; Brand, Verena; Ekanayake, Dilrukshi K; Sweeney, Kate; DiPaolo, Courtney; Reznikoff, William S; Sabatini, Robert

    2007-11-01

    Synthesis of the modified thymine base, beta-d-glucosyl-hydroxymethyluracil or J, within telomeric DNA of Trypanosoma brucei correlates with the bloodstream form specific epigenetic silencing of telomeric variant surface glycoprotein genes involved in antigenic variation. In order to analyze the function of base J in the regulation of antigenic variation, we are characterizing the regulatory mechanism of J biosynthesis. We have recently proposed a model in which chromatin remodeling by a SWI2/SNF2-like protein (JBP2) regulates the developmental and de novo site-specific localization of J synthesis within bloodstream form trypanosome DNA. Consistent with this model, we now show that JBP2 (-/-) bloodstream form trypanosomes contain five-fold less base J and are unable to stimulate de novo J synthesis in newly generated telomeric arrays. PMID:17706299

  9. Molecular and Clinical Characteristics of Hospital and Community Onset Methicillin-Resistant Staphylococcus aureus Strains Associated with Bloodstream Infections

    OpenAIRE

    Wang, Shu-Hua; Hines, Lisa; van Balen, Joany; José R Mediavilla; Pan, Xueliang; Hoet, Armando E; Kreiswirth, Barry N.; Pancholi, Preeti; Stevenson, Kurt B.

    2015-01-01

    Methicillin-resistant Staphylococcus aureus (MRSA) bloodstream infections (BSI) are classified epidemiologically as health care-associated hospital onset (HAHO)-, health care-associated community onset (HACO)-, or community-associated (CA)-MRSA. Clinical and molecular differences between HAHO- and HACO-MRSA BSI are not well known. Thus, we evaluated clinical and molecular characteristics of MRSA BSI to determine if distinct features are associated with HAHO- or HACO-MRSA strains. Molecular ge...

  10. The phosphoproteome of bloodstream form Trypanosoma brucei, causative agent of African sleeping sickness.

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    Nett, Isabelle R E; Martin, David M A; Miranda-Saavedra, Diego; Lamont, Douglas; Barber, Jonathan D; Mehlert, Angela; Ferguson, Michael A J

    2009-07-01

    The protozoan parasite Trypanosoma brucei is the causative agent of human African sleeping sickness and related animal diseases, and it has over 170 predicted protein kinases. Protein phosphorylation is a key regulatory mechanism for cellular function that, thus far, has been studied in T.brucei principally through putative kinase mRNA knockdown and observation of the resulting phenotype. However, despite the relatively large kinome of this organism and the demonstrated essentiality of several T. brucei kinases, very few specific phosphorylation sites have been determined in this organism. Using a gel-free, phosphopeptide enrichment-based proteomics approach we performed the first large scale phosphorylation site analyses for T.brucei. Serine, threonine, and tyrosine phosphorylation sites were determined for a cytosolic protein fraction of the bloodstream form of the parasite, resulting in the identification of 491 phosphoproteins based on the identification of 852 unique phosphopeptides and 1204 phosphorylation sites. The phosphoproteins detected in this study are predicted from their genome annotations to participate in a wide variety of biological processes, including signal transduction, processing of DNA and RNA, protein synthesis, and degradation and to a minor extent in metabolic pathways. The analysis of phosphopeptides and phosphorylation sites was facilitated by in-house developed software, and this automated approach was validated by manual annotation of spectra of the kinase subset of proteins. Analysis of the cytosolic bloodstream form T. brucei kinome revealed the presence of 44 phosphorylated protein kinases in our data set that could be classified into the major eukaryotic protein kinase groups by applying a multilevel hidden Markov model library of the kinase catalytic domain. Identification of the kinase phosphorylation sites showed conserved phosphorylation sequence motifs in several kinase activation segments, supporting the view that

  11. Trypanocidal action of bisphosphonium salts through a mitochondrial target in bloodstream form Trypanosoma brucei

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    Abdulsalam A.M. Alkhaldi

    2016-04-01

    Full Text Available Lipophilic bisphosphonium salts are among the most promising antiprotozoal leads currently under investigation. As part of their preclinical evaluation we here report on their mode of action against African trypanosomes, the etiological agents of sleeping sickness. The bisphosphonium compounds CD38 and AHI-9 exhibited rapid inhibition of Trypanosoma brucei growth, apparently the result of cell cycle arrest that blocked the replication of mitochondrial DNA, contained in the kinetoplast, thereby preventing the initiation of S-phase. Incubation with either compound led to a rapid reduction in mitochondrial membrane potential, and ATP levels decreased by approximately 50% within 1 h. Between 4 and 8 h, cellular calcium levels increased, consistent with release from the depolarized mitochondria. Within the mitochondria, the Succinate Dehydrogenase complex (SDH was investigated as a target for bisphosphonium salts, but while its subunit 1 (SDH1 was present at low levels in the bloodstream form trypanosomes, the assembled complex was hardly detectable. RNAi knockdown of the SDH1 subunit produced no growth phenotype, either in bloodstream or in the procyclic (insect forms and we conclude that in trypanosomes SDH is not the target for bisphosphonium salts. Instead, the compounds inhibited ATP production in intact mitochondria, as well as the purified F1 ATPase, to a level that was similar to 1 mM azide. Co-incubation with azide and bisphosphonium compounds did not inhibit ATPase activity more than either product alone. The results show that, in T. brucei, bisphosphonium compounds do not principally act on succinate dehydrogenase but on the mitochondrial FoF1 ATPase.

  12. Bromodomain Proteins Contribute to Maintenance of Bloodstream Form Stage Identity in the African Trypanosome.

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    Schulz, Danae; Mugnier, Monica R; Paulsen, Eda-Margaret; Kim, Hee-Sook; Chung, Chun-wa W; Tough, David F; Rioja, Inmaculada; Prinjha, Rab K; Papavasiliou, F Nina; Debler, Erik W

    2015-12-01

    Trypanosoma brucei, the causative agent of African sleeping sickness, is transmitted to its mammalian host by the tsetse. In the fly, the parasite's surface is covered with invariant procyclin, while in the mammal it resides extracellularly in its bloodstream form (BF) and is densely covered with highly immunogenic Variant Surface Glycoprotein (VSG). In the BF, the parasite varies this highly immunogenic surface VSG using a repertoire of ~2500 distinct VSG genes. Recent reports in mammalian systems point to a role for histone acetyl-lysine recognizing bromodomain proteins in the maintenance of stem cell fate, leading us to hypothesize that bromodomain proteins may maintain the BF cell fate in trypanosomes. Using small-molecule inhibitors and genetic mutants for individual bromodomain proteins, we performed RNA-seq experiments that revealed changes in the transcriptome similar to those seen in cells differentiating from the BF to the insect stage. This was recapitulated at the protein level by the appearance of insect-stage proteins on the cell surface. Furthermore, bromodomain inhibition disrupts two major BF-specific immune evasion mechanisms that trypanosomes harness to evade mammalian host antibody responses. First, monoallelic expression of the antigenically varied VSG is disrupted. Second, rapid internalization of antibodies bound to VSG on the surface of the trypanosome is blocked. Thus, our studies reveal a role for trypanosome bromodomain proteins in maintaining bloodstream stage identity and immune evasion. Importantly, bromodomain inhibition leads to a decrease in virulence in a mouse model of infection, establishing these proteins as potential therapeutic drug targets for trypanosomiasis. Our 1.25Å resolution crystal structure of a trypanosome bromodomain in complex with I-BET151 reveals a novel binding mode of the inhibitor, which serves as a promising starting point for rational drug design. PMID:26646171

  13. Probing the metabolic network in bloodstream-form Trypanosoma brucei using untargeted metabolomics with stable isotope labelled glucose.

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    Darren J Creek

    2015-03-01

    Full Text Available Metabolomics coupled with heavy-atom isotope-labelled glucose has been used to probe the metabolic pathways active in cultured bloodstream form trypomastigotes of Trypanosoma brucei, a parasite responsible for human African trypanosomiasis. Glucose enters many branches of metabolism beyond glycolysis, which has been widely held to be the sole route of glucose metabolism. Whilst pyruvate is the major end-product of glucose catabolism, its transamination product, alanine, is also produced in significant quantities. The oxidative branch of the pentose phosphate pathway is operative, although the non-oxidative branch is not. Ribose 5-phosphate generated through this pathway distributes widely into nucleotide synthesis and other branches of metabolism. Acetate, derived from glucose, is found associated with a range of acetylated amino acids and, to a lesser extent, fatty acids; while labelled glycerol is found in many glycerophospholipids. Glucose also enters inositol and several sugar nucleotides that serve as precursors to macromolecule biosynthesis. Although a Krebs cycle is not operative, malate, fumarate and succinate, primarily labelled in three carbons, were present, indicating an origin from phosphoenolpyruvate via oxaloacetate. Interestingly, the enzyme responsible for conversion of phosphoenolpyruvate to oxaloacetate, phosphoenolpyruvate carboxykinase, was shown to be essential to the bloodstream form trypanosomes, as demonstrated by the lethal phenotype induced by RNAi-mediated downregulation of its expression. In addition, glucose derivatives enter pyrimidine biosynthesis via oxaloacetate as a precursor to aspartate and orotate.

  14. Draft genome sequence of blaVeb-1, blaoxa-10 producing multi-drug resistant (MDR) Pseudomonas aeruginosa strain VRFPA09 recovered from bloodstream infection.

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    Murugan, Nandagopal; Malathi, Jambulingam; Umashankar, Vetrivel; Madhavan, Hajib NarahariRao

    2015-01-01

    Pseudomonas aeruginosa (P. aeruginosa) bacteremia causes significant mortality rate due to emergence of multidrug resistant (MDR) nosocomial infections. We report the draft genome sequence of P. aeruginosa strain VRFPA09, a human bloodstream isolate, phenotypically proven as MDR strain. Whole genome sequencing on VRFPA09, deciphered betalactamase encoding blav(eb-1) and bla(OXA-10) genes and multiple drug resistance, virulence factor encoding genes. PMID:26413042

  15. Impact of the introduction of an automated microbiologic system on the clinical outcomes of bloodstream infections caused by Enterobacteriaceae strains

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    Luciana Azevedo Callefi

    2013-01-01

    Full Text Available INTRODUCTION: Enterobacteriaceae strains are a leading cause of bloodstream infections (BSI. The aim of this study is to assess differences in clinical outcomes of patients with BSI caused by Enterobacteriaceae strains before and after introduction of an automated microbiologic system by the microbiology laboratory. METHODS: We conducted a retrospective cohort study aimed to evaluate the impact of the introduction of an automated microbiologic system (Phoenix(tm automated microbiology system, Becton, Dickinson and Company (BD - Diagnostic Systems, Sparks, MD, USA on the outcomes of BSIs caused by Enterobacteriaceae strains. The study was undertaken at Hospital São Paulo, a 750-bed teaching hospital in São Paulo, Brazil. Patients with BSI caused by Enterobacteriaceae strains before the introduction of the automated system were compared with patients with BSI caused by the same pathogens after the introduction of the automated system with regard to treatment adequacy, clinical cure/improvement and 14- and 28-day mortality rates. RESULTS: We evaluated 90 and 106 patients in the non-automated and automated testing periods, respectively. The most prevalent species in both periods were Klebsiella spp. and Proteus spp. Clinical cure/improvement occurred in 70% and 67.9% in non-automated and automated period, respectively (p=0.75. 14-day mortality rates were 22.2% and 30% (p=0.94 and 28-day mortality rates were 24.5% and 40.5% (p= 0.12. There were no significant differences between the two testing periods with regard to treatment adequacy, clinical cure/improvement and 14- and 28-day mortality rates. CONCLUSIONS: Introduction of the BD Phoenix(tm automated microbiology system did not impact the clinical outcomes of BSIs caused by Enterobacteriaceae strains in our setting.

  16. Resistance Markers and Genetic Diversity in Acinetobacter baumannii Strains Recovered from Nosocomial Bloodstream Infections

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    Hanoch S. I. Martins

    2014-01-01

    Full Text Available In this study, phenotypic and genotypic methods were used to detect metallo-β-lactamases, cephalosporinases and oxacillinases and to assess genetic diversity among 64 multiresistant Acinetobacter baumannii strains recovered from blood cultures in five different hospitals in Brazil from December 2008 to June 2009. High rates of resistance to imipenem (93.75% and polymyxin B (39.06% were observed using the disk diffusion (DD method and by determining the minimum inhibitory concentration (MIC. Using the disk approximation method, thirty-nine strains (60.9% were phenotypically positive for class D enzymes, and 51 strains (79.6% were positive for cephalosporinase (AmpC. Using the E-test, 60 strains (93.75% were positive for metallo-β-lactamases (MβLs. All strains were positive for at least one of the 10 studied genes; 59 (92.1% contained blaVIM-1, 79.6% contained blaAmpC, 93.7% contained blaOXA23 and 84.3% contained blaOXA51. Enterobacteria Repetitive Intergenic Consensus (ERIC-PCR analysis revealed a predominance of certain clones that differed from each other. However, the same band pattern was observed in samples from the different hospitals studied, demonstrating correlation between the genotypic and phenotypic results. Thus, ERIC-PCR is an appropriate method for rapidly clustering genetically related isolates. These results suggest that defined clonal clusters are circulating within the studied hospitals. These results also show that the prevalence of MDR A. baumannii may vary among clones disseminated in specific hospitals, and they emphasize the importance of adhering to appropriate infection control measures.

  17. The de novo and salvage pathways of GDP-mannose biosynthesis are both sufficient for the growth of bloodstream-form Trypanosoma brucei

    OpenAIRE

    Kuettel, Sabine; Wadum, Majken C T; Güther, Maria Lucia S; Mariño, Karina; Riemer, Carolin; Ferguson, Michael A. J.

    2012-01-01

    Summary The sugar nucleotide GDP-mannose is essential for Trypanosoma brucei. Phosphomannose isomerase occupies a key position on the de novo pathway to GDP-mannose from glucose, just before intersection with the salvage pathway from free mannose. We identified the parasite phosphomannose isomerase gene, confirmed that it encodes phosphomannose isomerase activity and localized the endogenous enzyme to the glycosome. We also created a bloodstream-form conditional null mutant of phosphomannose ...

  18. An Immunocompromised Child with Bloodstream Infection Caused by Two Escherichia coli Strains, One Harboring NDM-5 and the Other Harboring OXA-48-Like Carbapenemase.

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    Hasassri, M Earth; Boyce, Thomas G; Norgan, Andrew; Cunningham, Scott A; Jeraldo, Patricio R; Weissman, Scott; Patel, Robin; Banerjee, Ritu; Pogue, Jason M; Kaye, Keith S

    2016-06-01

    We describe a 16-year-old neutropenic patient from the Middle East with bloodstream infection caused by two carbapenemase-producing Escherichia coli isolates that we characterized by whole-genome sequencing. While one displayed meropenem resistance and was blaNDM positive, the other demonstrated meropenem susceptibility yet harbored blaOXA181 (which encodes a blaOXA48-like enzyme). This report highlights the challenge of laboratory detection of blaOXA48-like enzymes and the clinical implications of genotypic resistance detection in carbapenemase-producing Enterobacteriaceae. PMID:27217442

  19. Strain localization and damage prediction during sheet metal forming

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    Haddag, Badis; ABED-MERAIM, Farid; BALAN, Tudor

    2008-01-01

    This work aims to study the strain localization in different sheet metal forming processesby the finite element method using advanced behaviour models. In order to improve the prediction of the formability limit of sheets under forming it is important to consider constitutive models that take into account the degradation of material properties due to large strain localization. For this purpose, an elastic-plastic model has been coupled with the classical damage model of Lemaitre and Chaboche ...

  20. Strain distribution analysis of sputter-formed strained Si by tip-enhanced Raman spectroscopy

    OpenAIRE

    Hanafusa, H; Hirose, N.; Kasamatsu, A; Mimura, T; Matsui, T; Chong, H.M.H.; Mizuta, H.; Suda, Y.

    2011-01-01

    Simultaneous nanometer-scale measurements of the strain and surface undulation distributions of strained Si (s-Si) layers on strain-relief quadruple-Si1-xGex-layer buffers, using a combined atomic force microscopy (AFM) and tip-enhanced Raman spectroscopy (TERS) system, clarify that an s-Si sample formed by our previously proposed sputter epitaxy method has a smoother and more uniformly strained surface than an s-Si sample formed by gas-source molecular beam epitaxy. The TERS analyses suggest...

  1. Draft Genome Sequence of Colistin-Resistant Acinetobacter baumannii Strain VB22595 Isolated from a Central Line-Associated Bloodstream Infection.

    Science.gov (United States)

    Veeraraghavan, Balaji; Anandan, Shalini; Ragupathi, Naveen Kumar Devanga; Vijayakumar, Saranya; Sethuvel, Dhiviya Prabaa Muthuirulandi; Biswas, Indranil

    2016-01-01

    Acinetobacter baumannii is an important emerging pathogen that causes health care-associated infections. In this study, we determined the genome of a multidrug-resistant clinical strain, VB22595, isolated from a hospital in Southern India. The draft genome indicates that strain VB22595 encodes a genome of ~3.92 Mb in size and does not contain plasmid derived MCR-1 for colistin resistance. PMID:27516521

  2. Catheter-related bloodstream infection.

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    Goede, Matthew R; Coopersmith, Craig M

    2009-04-01

    Catheter-related bloodstream infections (CR-BSIs) are a common, frequently preventable complication of central venous catheterization. CR-BSIs can be prevented by strict attention to insertion and maintenance of central venous catheters and removing unneeded catheters as soon as possible. Antiseptic- or antibiotic-impregnated catheters are also an effective tool to prevent infections. The diagnosis of CR-BSI is made largely based on culture results. CR-BSIs should always be treated with antibiotics, and except in rare circumstances the infected catheter needs to be removed. PMID:19281894

  3. Strain Paths and Fractures in Rotational Symmetric Multi Stage Single Point Incremental Forming

    DEFF Research Database (Denmark)

    Skjødt, Martin; Silva, M.B.; Martins, P.A.F.;

    2008-01-01

    A multi stage strategy, which allows forming of SPIF parts with vertical walls, is investigated with emphasis on strain paths and fracture strains. Whereas downwards movement of the tool pin results in deformation close to plane strain upwards moving tool results in biaxial strains. A good correl...

  4. Strain Paths and Fractures in Rotational Symmetric Multi Stage Single Point Incremental Forming

    DEFF Research Database (Denmark)

    Skjødt, Martin; Silva, M.B.; Martins, P.A.F.; Bay, Niels

    A multi stage strategy, which allows forming of SPIF parts with vertical walls, is investigated with emphasis on strain paths and fracture strains. Whereas downwards movement of the tool pin results in deformation close to plane strain upwards moving tool results in biaxial strains. A good correl...

  5. Stress models of depression: forming genetically vulnerable strains.

    Science.gov (United States)

    Henn, Fritz A; Vollmayr, Barbara

    2005-01-01

    Among the most useful models for depressive disorders are those, which involve a stress induced change in behaviour. Learned helplessness is one such model and is induced through exposure to uncontrollable and unpredictable aversive events. Learned helplessness as induced in rats using foot shock is well characterized and has good face validity and predictive validity as a model of depression, including alterations in HPA axis activity and REM sleep characteristic of depression. The data concerning the validity will be briefly reviewed. The model can also be used to look at the role of genetics through selective breeding. These studies will be reviewed and the utility of the genetic strains for understanding the interaction of stress and affect will be examined. A second model of depression using exposure to chronic stress also has high face and predictive validity. A new form of this approach, recently described, also is suitable for the examination of genetic factors leading to depressive like behaviour and this will be presented. PMID:15925700

  6. Interação entre Trypanosoma cruzi e macrófagos: diferenças entre tripomastigotas sangüí-colas e de cultivo de tecidos Trypanosoma cruzi interaction with macrophages: differences between tissue culture and bloodstream forms

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    Judith K. Kloetzel

    1984-08-01

    Full Text Available Macrófagos obtidos do peritoneo de camundongos após estímulo, com peptona, foram cultivados em lamínulas, infectados com tripomastigotas das cepas F e Y de T. cruzi, obtidos de cultivo de tecidos ou do sangue de camundongos infectados. Os parasitas, obtidos de cultivo de tecidos, tanto da cepa Y como os da cepa F, são interiorizados por macrófagos em proporção muito mais elevada do que os sanguícolas. Parasitas de cultivo de tecidos incubados com soro de camundongos normais, ou soro híperimune específico em diluição sub-aglutinante, comportam-se essencialmente como parasitas não opsonizados. Foram observadas diferenças a nível ultraestrutural na fase inicial de interação entre macrófagos e tripomastigotas das duas origens. Após 30 minutos, tripomastigotas de cultivo de tecidos localizam-se em agrupamentos na área de contato com os macrófagos. Enquanto os tripomastigotas sanguícolas estão na maioria das vezes no interior de vacúolos fagocíticos largos, após 3 horas de interação os tripomastigotas de cultura situam-se em um único vacúolo estreito. Tanto as formas de cultivo de tecidos quanto os tripomastigotas sanguícolas da cepa Y multiplicam-se em macrófagos; os tripomastigotas sanguícolas da cepa F são destruídos no interior da célula hospedeira, enquanto os tripomastigotas de cultivo de tecidos desta cepa são capazes de multiplicar-se.Mouse peritoneal elicited macrophages cultured on coverslips were infected with Trypanosoma cruzi trypomastigotes from both the F strain and Y strain obtained either from tissue culture or from the bloodstream of infected mice. Both the Y strain and F parasites obtained from tissue culture were interiorized by macrophages at a much higher rate than bloodstream trypomastigotes. Tissue culture parasites incubated with normal mouse serum, mouse plasma obtained at the 7th day after infection, or specific hyperimmune serum at subagglutinating concentration, behaved essentially as

  7. Staphylococcus aureus Regulatory RNAs as Potential Biomarkers for Bloodstream Infections.

    Science.gov (United States)

    Bordeau, Valérie; Cady, Anne; Revest, Matthieu; Rostan, Octavie; Sassi, Mohamed; Tattevin, Pierre; Donnio, Pierre-Yves; Felden, Brice

    2016-09-01

    Staphylococcus aureus is a commensal bacterium and pathogen. Identifying biomarkers for the transition from colonization to disease caused by this organism would be useful. Several S. aureus small RNAs (sRNAs) regulate virulence. We investigated presence and expression of 8 sRNAs in 83 S. aureus strains from 42 patients with sepsis or septic shock and 41 asymptomatic colonized carriers. Small pathogenicity island sRNAs sprB and sprC were clade specific. Six sRNAs had variable expression not correlated with clinical status. Expression of RNAIII was lower in strains from septic shock patients than in strains from colonized patients. When RNAIII was associated with expression of sprD, colonizing strains could be discriminated from strains in patients with bloodstream infections, including patients with sepsis and septic shock. Isolates associated with colonization might have sRNAs with target expression different from those of disease isolates. Monitoring expression of RNAIII and sprD could help determine severity of bloodstream infections. PMID:27224202

  8. Clonal relationships among bloodstream isolates of Escherichia coli.

    OpenAIRE

    Maslow, J.N.; Whittam, T S; Gilks, C F; Wilson, R A; Mulligan, M E; Adams, K S; Arbeit, R D

    1995-01-01

    The clonal relationships among 187 bloodstream isolates of Escherichia coli from 179 patients at Boston, Mass., Long Beach, Calif., and Nairobi, Kenya, were determined by multilocus enzyme electrophoresis (MLEE), analysis of polymorphisms associated with the ribosomal operon (ribotyping), and serotyping. MLEE based on 20 enzymes resolved 101 electrophoretic types (ETs), forming five clusters; ribotyping resolved 56 distinct patterns concordant with the analysis by MLEE. The isolates at each s...

  9. Proof that Burkholderia Strains Form Effective Symbioses with Legumes: a Study of Novel Mimosa-Nodulating Strains from South America

    OpenAIRE

    Chen, Wen-Ming; de Faria, Sergio M.; Straliotto, Rosângela; Pitard, Rosa M.; Simões-Araùjo, Jean L.; Chou, Jui-Hsing; Chou, Yi-Ju; Barrios, Edmundo; Prescott, Alan R; Geoffrey N Elliott; Sprent, Janet I.; J. Peter W. Young; James, Euan K.

    2005-01-01

    Twenty Mimosa-nodulating bacterial strains from Brazil and Venezuela, together with eight reference Mimosa-nodulating rhizobial strains and two other β-rhizobial strains, were examined by amplified rRNA gene restriction analysis. They fell into 16 patterns and formed a single cluster together with the known β-rhizobia, Burkholderia caribensis, Burkholderia phymatum, and Burkholderia tuberum. The 16S rRNA gene sequences of 15 of the 20 strains were determined, and all were shown to belong to t...

  10. Tetracycline-resistant L-forms isolated from an antibiotic-susceptible strain of Listeria monocytogenes.

    OpenAIRE

    Schmitt-Slomska, J; Marmouset, M C; Louis, C.; Bally, R.; Starka, G; Madoff, S

    1982-01-01

    A tetracycline-susceptible strain of Listeria monocytogenes type 4b was converted to stable L-forms by penicillin. L-form variants resistant to tetracycline were then selected from a predominantly tetracycline-susceptible L-form population on plates containing penicillin and increasing concentrations of tetracycline. The origin of tetracycline-resistant L-forms from the parent Listeria strain was confirmed biochemically, by immunofluorescence, and by polyacrylamide gel electrophoresis. Scanni...

  11. Post-UV colony-forming ability of normal fibroblast strains and of the xeroderma pigmentosum group G strain

    International Nuclear Information System (INIS)

    In xeroderma pigmentosum, an inherited disorder of defective DNA repair, post-uv colony-forming ability of fibroblasts from patients in complementation groups A through F correlates with the patients' neurological status. The first xeroderma pigmentosum patient assigned to the recently discovered group G had the neurological abnormalities of XP. Researchers have determined the post-uv colony-forming ability of cultured fibroblasts from this patient and from 5 more control donors. Log-phase fibroblasts were irradiated with 254 nm uv light from a germicidal lamp, trypsinized, and replated at known densities. After 2 to 4 weeks' incubation the cells were fixed, stained and scored for colony formation. The strains' post-uv colony-forming ability curves were obtained by plotting the log of the percent remaining post-uv colony-forming ability as a function of the uv dose. The post-uv colony-forming ability of 2 of the 5 new normal strains was in the previously defined control donor zone, but that of the other 3 extended down to the level of the most resistant xeroderma pigmentosum strain. The post-uv colony-forming ability curve of the group G fibroblasts was not significantly different from the curves of the group D fibroblast strains from patients with clinical histories similar to that of the group G patient

  12. Numerical study of strain-rate effect in cold rolls forming of steel

    Science.gov (United States)

    Falsafi, J.; Demirci, E.; Silberschmidt, V. V.

    2013-07-01

    Cold roll forming (CRF) is a well-known continuous manufacturing process, in which a flat strip is deformed by successive rotating pairs of tools, without changing the material thickness. In the past decades, to lessen the process-development efforts, finite-element simulations have been increasingly employed to improve the process design and predict the manufacturing-induced defects. One of the important aspects in design of the CRF process is consideration of resulting strains in the final product as the material passes through several complex forming stands. Sufficient knowledge of longitudinal strain in the workpiece is required to set various process parameters. Increasing a process speed in a roll forming operation can bring cost advantages, but the influence of the forming speed on the strain distribution should be explored. This study is focussed on a strain-rate effect in the CRF process of steel sheets. The strain-rate dependency of a plastic behaviour observed in most metals can affect the finished product's quality as well as process parameters. This paper investigates the influence of the strain rate on longitudinal strains induced in the roll forming operation by incorporating a phenomenological Johnson-Cook constitutive model, which allows studying the impact of the process speed on the output product. Taking advantage of 3D finite element analysis, a roll forming process was simulated using MCS.Marc, comprising a complete set of forming stations. Through the changing of the process speed, the strain rate impact on longitudinal peak strains and forming length was investigated. The results highlight the effect of the strain rate on edge thinning and subsequent undesirable distortions in the product.

  13. Clonal relationships among bloodstream isolates of Escherichia coli.

    Science.gov (United States)

    Maslow, J N; Whittam, T S; Gilks, C F; Wilson, R A; Mulligan, M E; Adams, K S; Arbeit, R D

    1995-01-01

    The clonal relationships among 187 bloodstream isolates of Escherichia coli from 179 patients at Boston, Mass., Long Beach, Calif., and Nairobi, Kenya, were determined by multilocus enzyme electrophoresis (MLEE), analysis of polymorphisms associated with the ribosomal operon (ribotyping), and serotyping. MLEE based on 20 enzymes resolved 101 electrophoretic types (ETs), forming five clusters; ribotyping resolved 56 distinct patterns concordant with the analysis by MLEE. The isolates at each study site formed a genetically diverse group and demonstrated similar clonal structures, with the same small subset of lineages accounting for the majority of isolates at each site. Moreover, two ribotypes accounted for approximately 30% of the isolates at each study site. One cluster contained the majority (65%) of isolates and, by direct comparison of the ETs and ribotypes of individual isolates, was genetically indistinguishable from the largest cluster for each of two other collections of E. coli causing pyelonephritis and neonatal meningitis (R. K. Selander, T. K. Korhonen, V. Väisänen-Rhen, P. H. Williams, P. E. Pattison, and D. A. Caugent, Infect. Immun. 52:213-222, 1986; M. Arthur, C. E. Johnson, R. H. Rubin, R. D. Arbeit, C. Campanelli, C. Kim, S. Steinbach, M. Agarwal, R. Wilkinson, and R. Goldstein, Infect. Immun. 57:303-313, 1989), thus defining a virulent set of lineages. The isolates within these virulent lineages typically carried DNA homologous to the adhesin operon pap or sfa and the hemolysin operon hly and expressed O1, O2, O4, O6, O18, O25, or O75 antigens. DNA homologous to pap was distributed among isolates of each major cluster, whereas hly was restricted to isolates of two clusters, typically detected in pap-positive strains, and sfa was restricted to isolates of one cluster, typically detected in pap- and hly-positive strains. The occurrence of pap-positive isolates in the same geographically and genetically divergent lineages suggests that this

  14. Finite element simulations of sheet metal forming under complex strain paths

    Institute of Scientific and Technical Information of China (English)

    CHEN Wei; YANG Jichang; WU Xiaofeng; LU Dun; GUO Weigang

    2007-01-01

    Fracture is a common defect in sheet metal forming and it is essentially caused by tensile instability. This paper analyzes some experiments and theories for building forming limit diagrams of sheet metal and points out the advantages and disadvantages of current experiments and theories. According to this, a method that integrates the finite element simulation and experiment was used to research the forming limit diagrams of the sheet metal under complex strain paths. Taking the rear hanger that undergoes twice stamping as an example, the strain paths of the dangerous point of the rear hanger is investigated. Finally, the forming method of the rear hanger is confirmed. Results indicate that finite element method (FEM) can achieve the complex strain paths and different strain paths will have great impacts on the result of the sheet metal forming.

  15. In vitro biofilm forming capacity on abiotic contact surfaces by outbreak-associated Vibrio harveyi strains

    Institute of Scientific and Technical Information of China (English)

    Pallaval Veera Bramha Chari; Kuchipudi Viswadeepika; Bottu Anand Kumar

    2014-01-01

    Objective:To evaluate the in vitro biofilm forming capacity on abiotic food contact surfaces by Vibrio harveyi (V. harveyi) strains. Methods:Thirty six Gram-negative V. harveyi strains were isolated from various street vended seafood outlets in a food processing line and evaluated for their ability to produce mucoid biofilms on food contact surfaces using a microplate assay. Phenotypic characterization of mucoid biofilm producing V. harveyi strains were screened on Congo red agar, thiosulfate-citrate-bile salts-sucrose agar and tryptic soy agar, respectively. Results: Only five V. harveyi strains (14%) were mucoid biofilm producers characterized by formation of black colonies, whereas the remaining 31 strains (86%) were not capable of producing biofilm characterized by formation of red colonies or pinkish-red colonies with darkening at the centre. The morphological, physiological and biochemical characteristics of these isolates were studied using standard protocols. Strain identification was confirmed by polymerase chain reaction targeted to species-specific polymerase chain reaction primers VH-1 and VH-2 corresponding to variable regions of V. harveyi 16S rRNA sequence. All the biofilm-forming strains showed resistance to at least three antimicrobial compounds tested. V. harveyi strains isolated from various seafood were able to form biofilms of different capacity, and the strains VB267, VB238 and VB166 isolated from cat fish, shrimp and eel fish exhibited significantly greater biofilm forming ability compared to other isolates. Conclusions: It can be concluded from the present study that the strain VB166 was able to better attach and form subsequent biofilms on glass and stainless steel compared to high density polyethylene. These properties allow these bacteria to survive, proliferate and persist in street vended seafood outlets.

  16. In vitro biofilm forming capacity on abiotic contact surfaces by outbreak-associated Vibrio harveyi strains

    Directory of Open Access Journals (Sweden)

    Pallaval Veera Bramha Chari

    2014-02-01

    Full Text Available Objective: To evaluate the in vitro biofilm forming capacity on abiotic food contact surfaces by Vibrio harveyi (V. harveyi strains. Methods: Thirty six Gram-negative V. harveyi strains were isolated from various street vended seafood outlets in a food processing line and evaluated for their ability to produce mucoid biofilms on food contact surfaces using a microplate assay. Phenotypic characterization of mucoid biofilm producing V. harveyi strains were screened on Congo red agar, thiosulfate-citrate-bile salts-sucrose agar and tryptic soy agar, respectively. Results: Only five V. harveyi strains (14% were mucoid biofilm producers characterized by formation of black colonies, whereas the remaining 31 strains (86% were not capable of producing biofilm characterized by formation of red colonies or pinkish-red colonies with darkening at the centre. The morphological, physiological and biochemical characteristics of these isolates were studied using standard protocols. Strain identification was confirmed by polymerase chain reaction targeted to species-specific polymerase chain reaction primers VH-1 and VH-2 corresponding to variable regions of V. harveyi 16S rRNA sequence. All the biofilm-forming strains showed resistance to at least three antimicrobial compounds tested. V. harveyi strains isolated from various seafood were able to form biofilms of different capacity, and the strains VB267, VB238 and VB166 isolated from cat fish, shrimp and eel fish exhibited significantly greater biofilm forming ability compared to other isolates. Conclusions: It can be concluded from the present study that the strain VB166 was able to better attach and form subsequent biofilms on glass and stainless steel compared to high density polyethylene. These properties allow these bacteria to survive, proliferate and persist in street vended seafood outlets.

  17. Bloodstream Infections in a Neonatal Intensive Care Unit

    Directory of Open Access Journals (Sweden)

    Mehmet Sah Ižpek

    2014-12-01

    Full Text Available Aim: To determine the pattern of bloodstream infections (BSIs and antimicrobial susceptibility of pathogens in a neonatal intensive care unit (NICU.Material and Method: Positive hemoculture of neonates diagnosed with nosocomial sepsis from March 2011 to March 2014 in the NICU of Diyarbakir Maternity and Children%u2019s Hospital, in the southeastern region of Anatolia, Turkey, were retrospectively reviewed. Results: A total of 148 pathogens were isolated in 142 neonates. The most common microorganisms isolated were Klebsiella pneumoniae (40.5% and Acinetobacter baumannii (29.7% which was a result of a hospital outbreak. Multi-drug resistant (MDR strains accounted for 20.0% of K. pneumoniae isolates and 93.2% of A. baumannii isolates. The sepsis-attributable mortality rate was higher in cases infected with MDR strains than in cases infected without MDR strains or Candida spp (24% vs. 9.7%, p=0.032. Discussion: In our unit, BSIs were more often caused by Gram negative bacteria. BSIs caused by MDR strains were associated with a higher rate of sepsis-attributable mortality.

  18. Bloodstream infections in patients with liver cirrhosis.

    Science.gov (United States)

    Bartoletti, Michele; Giannella, Maddalena; Lewis, Russell Edward; Viale, Pierluigi

    2016-04-01

    Bloodstream infections are a serious complication in patients with liver cirrhosis. Dysregulated intestinal bacterial translocation is the predominant pathophysiological mechanism of infections in this setting. For this reason enteric Gram-negative bacteria are commonly encountered as the first etiological cause of infection. However, through the years, the improvement in the management of cirrhosis, the recourse to invasive procedures and the global spread of multidrug resistant pathogens have importantly changed the current epidemiology. Bloodstream infections in cirrhotic patients are characterized by high mortality rate and complications including metastatic infections, infective endocarditis, and endotipsitis (or transjugular intrahepatic portosystemic shunt-related infection). For this reason early identification of patients at risk for mortality and appropriated therapeutic management is mandatory. Liver cirrhosis can significantly change the pharmacokinetic behavior of antimicrobials. In fact hypoproteinaemia, ascitis and third space expansion and impairment of renal function can be translated in an unpredictable drug exposure. PMID:26864729

  19. Nosocomial Bloodstream Infection and Clinical Sepsis

    OpenAIRE

    Hugonnet, Stéphane; Sax, Hugo; Eggimann, Philippe; Chevrolet, Jean-Claude; Pittet, Didier

    2004-01-01

    Primary bloodstream infection (BSI) is a leading, preventable infectious complication in critically ill patients and has a negative impact on patients’ outcome. Surveillance definitions for primary BSI distinguish those that are microbiologically documented from those that are not. The latter is known as clinical sepsis, but information on its epidemiologic importance is limited. We analyzed prospective on-site surveillance data of nosocomial infections in a medical intensive care unit. Of th...

  20. Draft Genome Sequence of Bacillus clausii UBBC07, a Spore-Forming Probiotic Strain.

    Science.gov (United States)

    Upadrasta, Aditya; Pitta, Swetha; Madempudi, Ratna Sudha

    2016-01-01

    ITALIC! Bacillus clausiiUBBC07 is a safe endospore-forming strain, characterized for defined therapeutic effects. The finished draft whole-genome sequence is presented here to scan its genetic constitution for its expanded use as a probiotic in various health sectors. PMID:27103711

  1. Draft Genome Sequence of the Spore-Forming Probiotic Strain Bacillus coagulans Unique IS-2.

    Science.gov (United States)

    Upadrasta, Aditya; Pitta, Swetha; Madempudi, Ratna Sudha

    2016-01-01

    ITALIC! Bacillus coagulansUnique IS-2 is a potential spore-forming probiotic that is commercially available on the market. The draft genome sequence presented here provides deep insight into the beneficial features of this strain for its safe use as a probiotic for various human and animal health applications. PMID:27103709

  2. Draft Genome Sequence of the Spore-Forming Probiotic Strain Bacillus coagulans Unique IS-2

    Science.gov (United States)

    Upadrasta, Aditya; Pitta, Swetha

    2016-01-01

    Bacillus coagulans Unique IS-2 is a potential spore-forming probiotic that is commercially available on the market. The draft genome sequence presented here provides deep insight into the beneficial features of this strain for its safe use as a probiotic for various human and animal health applications. PMID:27103709

  3. Draft Genome Sequence of Bacillus clausii UBBC07, a Spore-Forming Probiotic Strain

    Science.gov (United States)

    Upadrasta, Aditya; Pitta, Swetha

    2016-01-01

    Bacillus clausii UBBC07 is a safe endospore-forming strain, characterized for defined therapeutic effects. The finished draft whole-genome sequence is presented here to scan its genetic constitution for its expanded use as a probiotic in various health sectors. PMID:27103711

  4. BIOSORPTION OF CHROMIUM (VI FROM INDUSTRIAL EFFLUENT BY WILD ANDMUTANT TYPE STRAIN OF SACCHAROMYCES CEREVISIAE AND ITS IMMOBILIZED FORM

    Directory of Open Access Journals (Sweden)

    K Selvam, K Arungandhi, B Vishnupriya, T Shanmuga priya and M Yamuna

    2013-01-01

    Full Text Available Biosorption of chromium was studied by wild type Saccharomyces cerevisiae strain, mutant strain, immobilized-wild type and mutant strain. Chromium absorption pattern was observed in all experimental conditions. Hexavalent chromium (VI was analyzed by diphenyl carbazide method, by oxidizing the trivalent chromium (III. The percentage efficiency of wild type S. cerevisiae and its mutant strain, immobilized-wild type and mutant strain were 94.8%, 98.7%, 97.4% and 100% respectively. S. cerevisiae mutant strain and their immobilized form was found to be effective in biosorption of chromium (VI than the wild type forms.

  5. Photodynamic therapy for the eradication of biofilms formed by catheter associated Pseudomonas aeruginosa strains

    Directory of Open Access Journals (Sweden)

    Viviana Teresa Orlandi

    2011-06-01

    Full Text Available Pseudomonas aeruginosa has emerged as a major opportunistic pathogen causing catheter-associated urinary tract infections (CA-UTIs associated with high mortality and morbidity. In this study 18 P. aeruginosa isolates from urine of catheterized patients were evaluated for in vitro biofilm formation.All the tested strains showed the ability to form biofilm more thicker than those formed by a cohort of 29 blood culture strains belonging to the same species. Photodynamic antimicrobial chemotherapy (PACT is a novel antimicrobial treatment that exploits a photosensitizer (PS and visible light to induce lethal oxidative damages in bacterial cells and could be used as local antimicrobial approach in CA-UTIs. Here we tested the susceptibility of planktonic and sessile cultures of P. aeruginosa strains, the model strain PAO1 and CA-UTI isolates, to photodynamic inactivation with a di cationic porphyrinic photosensitizer, the 5, 15-di (N-benzyl-4-pyridynium-porphyrin di chloride.Although Pseudomonas aeruginosa is regarded as a difficult target for antimicrobial chemotherapy, satisfactory bactericidal activities on both planktonic and biofilm cultures were observed.

  6. Stress-strain properties of natural and biomimetically formed collagen constructs.

    Science.gov (United States)

    Ionescu, Clara; Chirita, Mihai

    2008-01-01

    The biomimetic formed solution of collagen reconstituted films into native fibers proved to be of high interest because of its regenerative medical applications. A variety of tests to characterize the mechanical properties of biomimetic engineered films are illustrated in this paper. Based on our previous results, the modulus of elasticity and the ultimate strain of reconstituted collagen films were compared to the reported stress-strain data in the literature on various tissues (animal material), correlating the achieved properties with possible use for artificial tissue implants. The results presented in this study, with great potential to provide reference data for future work, show that the mechanical properties of the biomimetically formed collagen films is close to that of several native collagen fibers, a fact which suggests their use in medical applications. PMID:19212039

  7. Prediction of strain localization in sheet metal forming using elastoplastic-damage model and localization criterion

    OpenAIRE

    Haddag, Badis; ABED-MERAIM, Farid; BALAN, Tudor

    2007-01-01

    The aim of this work is to study the strain localization during the plastic deformation of sheets metals. This phenomenon is precursor for the fracture of drawing parts, thus its prediction using advanced behavior models is important in order to obtain safe final parts. Most often, an accurate prediction of localization during forming process requires damage to be included in the simulation. For this purpose, an advanced, anisotropic elastoplastic model, combining isotropic and kinematic hard...

  8. Investigation of advanced strain-path dependent material models for sheet metal forming simulations

    OpenAIRE

    Haddag, Badis; BALAN, Tudor; ABED-MERAIM, Farid

    2006-01-01

    Sheet metal forming processes often involve complex loading sequences. To improve the prediction of some undesirable phenomena, such as springback, physical behavior models should be considered. This paper investigates springback behavior predicted by advanced elastoplastic hardening models which combine isotropic and kinematic hardening and take strain-path changes into account. A dislocation-based microstructural hardening model formulated from physical observations and the more classical c...

  9. Forming reproducible non-lithographic nanocontacts to assess the effect of contact compressive strain in nanomaterials

    International Nuclear Information System (INIS)

    The application of electrical nanoprobes to measure and characterize nanomaterials has become widely spread. However, the formation of quality electrical contacts using metallic probes on nanostructures has not been directly assessed. We investigate here the electrical behaviour of non-lithographically formed contacts to ZnO nanowires (NWs) and develop a method to reproducibly form Ohmic contacts for accurate electrical measurement of the nanostructures. The contacting method used in this work relies on an electrical feedback mechanism to determine the point of contact to the individual NWs, ensuring minimal compressive strain at the contact. This developed method is compared with the standard tip deflection contacting technique and shows a significant improvement in reproducibility. The effect of excessive compressive strain at the contact was investigated, with a change from rectifying to ohmic I–V behaviour observed as compressive strain at the contact was increased, leading to irreversible changes to the electrical properties of the NW. This work provides an ideal method for forming reproducible non-lithographic nanocontacts to a multitude of nanomaterials. (paper)

  10. Kinetoplast adaptations in American strains from Trypanosoma vivax

    International Nuclear Information System (INIS)

    Highlights: • American T. vivax strains exhibit a drastic process of mitochondrial genome degradation. • T. vivax mitochondrial genes have among the fastest evolutionary rates in eukaryotes. • High rates of kDNA evolution are associated with relaxation of selective constrains. • Relaxed selective pressures are the result of mechanical transmission. • The evolutionary strategy of T. vivax differs from that of T. brucei-species complex. - Abstract: The mitochondrion role changes during the digenetic life cycle of African trypanosomes. Owing to the low abundance of glucose in the insect vector (tsetse flies) the parasites are dependent upon a fully functional mitochondrion, capable of performing oxidative phosphorylation. Nevertheless, inside the mammalian host (bloodstream forms), which is rich in nutrients, parasite proliferation relies on glycolysis, and the mitochondrion is partially redundant. In this work we perform a comparative study of the mitochondrial genome (kinetoplast) in different strains of Trypanosoma vivax. The comparison was conducted between a West African strain that goes through a complete life cycle and two American strains that are mechanically transmitted (by different vectors) and remain as bloodstream forms only. It was found that while the African strain has a complete and apparently fully functional kinetoplast, the American T. vivax strains have undergone a drastic process of mitochondrial genome degradation, in spite of the recent introduction of these parasites in America. Many of their genes exhibit different types of mutations that are disruptive of function such as major deletions, frameshift causing indels and missense mutations. Moreover, all but three genes (A6-ATPase, RPS12 and MURF2) are not edited in the American strains, whereas editing takes place normally in all (editable) genes from the African strain. Two of these genes, A6-ATPase and RPS12, are known to play an essential function during bloodstream stage

  11. Kinetoplast adaptations in American strains from Trypanosoma vivax

    Energy Technology Data Exchange (ETDEWEB)

    Greif, Gonzalo [Unidad de Biología Molecular, Institut Pasteur de Montevideo (Uruguay); Rodriguez, Matías [Sección Biomatemática, Facultad de Ciencias, Universidad de la Republica (Uruguay); Reyna-Bello, Armando [Departamento de Ciencias de la Vida, Carrera en Ingeniería en Biotecnología, Universidad de las Fuerzas Armadas (Ecuador); Centro de Estudios Biomédicos y Veterinarios, Universidad Nacional Experimental Simón Rodríguez-IDECYT, Caracas (Venezuela, Bolivarian Republic of); Robello, Carlos [Unidad de Biología Molecular, Institut Pasteur de Montevideo (Uruguay); Departamento de Bioquímica, Facultad de Medicina, Universidad de la República Uruguay (Uruguay); Alvarez-Valin, Fernando, E-mail: falvarez@fcien.edu.uy [Sección Biomatemática, Facultad de Ciencias, Universidad de la Republica (Uruguay)

    2015-03-15

    Highlights: • American T. vivax strains exhibit a drastic process of mitochondrial genome degradation. • T. vivax mitochondrial genes have among the fastest evolutionary rates in eukaryotes. • High rates of kDNA evolution are associated with relaxation of selective constrains. • Relaxed selective pressures are the result of mechanical transmission. • The evolutionary strategy of T. vivax differs from that of T. brucei-species complex. - Abstract: The mitochondrion role changes during the digenetic life cycle of African trypanosomes. Owing to the low abundance of glucose in the insect vector (tsetse flies) the parasites are dependent upon a fully functional mitochondrion, capable of performing oxidative phosphorylation. Nevertheless, inside the mammalian host (bloodstream forms), which is rich in nutrients, parasite proliferation relies on glycolysis, and the mitochondrion is partially redundant. In this work we perform a comparative study of the mitochondrial genome (kinetoplast) in different strains of Trypanosoma vivax. The comparison was conducted between a West African strain that goes through a complete life cycle and two American strains that are mechanically transmitted (by different vectors) and remain as bloodstream forms only. It was found that while the African strain has a complete and apparently fully functional kinetoplast, the American T. vivax strains have undergone a drastic process of mitochondrial genome degradation, in spite of the recent introduction of these parasites in America. Many of their genes exhibit different types of mutations that are disruptive of function such as major deletions, frameshift causing indels and missense mutations. Moreover, all but three genes (A6-ATPase, RPS12 and MURF2) are not edited in the American strains, whereas editing takes place normally in all (editable) genes from the African strain. Two of these genes, A6-ATPase and RPS12, are known to play an essential function during bloodstream stage

  12. Plane strain finite element analysis of sheet forming operations including bending effects

    Science.gov (United States)

    Cho, Uk Youn

    1993-01-01

    An improved finite element method suitable for the plane-strain analysis of sheet metal forming operations is presented. The method incorporates a computationally efficient shell model and a consistent frictional contact algorithm through an implicit updated Lagrangian formulation. The workpiece material model is rigid-viscoplastic with a choice of power law hardening and plastic normal anisotropy and is capable of modeling a wide variety of sheet metals. A simplified nonlinear incremental shell theory is employed along with an optional reduced integration through the thickness for computational efficiency, while retaining the advantages of the kinematic model containing the bending effects. Complex tool geometry can be handled by discrete data points, by primitives (lines and arcs), or by analytical functions. The capabilities of the method are demonstrated through verification problems and comparisons with experimental data, benchmark results, and published data for several practical problems of the sheet metal forming industry. The problems include stretching and/or deep drawing operations, simulation of automobile panel section, and brake bending operation. As an independent investigation from the first portion of the dissertation, measured data from a set of simple bending experiments of two types of aluminum are presented and analyzed. Generated data from the experiments include strain histories (loading and unloading), spring back information (spring back angle and strains), and friction coefficients. As a by-product, a simple way of estimating the friction coefficient (Coulomb's law) during a bending operation is proposed and demonstrated.

  13. Biofilm-based central line-associated bloodstream infections.

    Science.gov (United States)

    Yousif, Ammar; Jamal, Mohamed A; Raad, Issam

    2015-01-01

    Different types of central venous catheters (CVCs) have been used in clinical practice to improve the quality of life of chronically and critically ill patients. Unfortunately, indwelling devices are usually associated with microbial biofilms and eventually lead to catheter-related bloodstream infections (CLABSIs).An estimated 250,000-400,000 CLABSIs occur every year in the United States, at a rate of 1.5 per 1,000 CVC days and a mortality rate of 12-25 %. The annual cost of caring for patients with CLABSIs ranges from 296 million to 2.3 billion dollars.Biofilm formation occurs on biotic and abiotic surfaces in the clinical setting. Extensive studies have been conducted to understand biofilm formation, including different biofilm developmental stages, biofilm matrix compositions, quorum-sensing regulated biofilm formation, biofilm dispersal (and its clinical implications), and multi-species biofilms that are relevant to polymicrobial infections.When microbes form a matured biofilm within human hosts through medical devices such as CVCs, the infection becomes resistant to antibiotic treatment and can develop into a chronic condition. For that reason, many techniques have been used to prevent the formation of biofilm by targeting different stages of biofilm maturation. Other methods have been used to diagnose and treat established cases of CLABSI.Catheter removal is the conventional management of catheter associated bacteremia; however, the procedure itself carries a relatively high risk of mechanical complications. Salvaging the catheter can help to minimize these complications.In this article, we provide an overview of microbial biofilm formation; describe the involvement of various genetic determinants, adhesion proteins, organelles, mechanism(s) of biofilm formation, polymicrobial infections, and biofilm-associated infections on indwelling intravascular catheters; and describe the diagnosis, management, and prevention of catheter-related bloodstream infections

  14. Bloodstream infections in patients with solid tumors.

    Science.gov (United States)

    Gudiol, Carlota; Aguado, José María; Carratalà, Jordi

    2016-04-01

    Little information is currently available regarding bloodstream infection (BSI) in patients with solid tumors who, for a variety of reasons, are particularly predisposed to develop this condition. In this review we focus on the incidence, epidemiology, clinical features, etiology, antimicrobial resistance, and outcomes of BSI of adult cancer patients with solid tumors. Most episodes of BSI occur in non-neutropenic patients, in whom the site of primary or metastatic tumor often serves as the portal of entry. The urinary tract and the abdomen are the most frequent sources of infection, and cholangitis is the most common recurrent source of BSI. Gram-negative bacilli are becoming the leading cause of BSI in patients with solid tumors, and the rate of multidrug resistance is increasingly being recognized. The case-fatality rate in patients with solid tumors and BSI is high, especially among those with comorbidities, advanced neoplasms, corticosteroid therapy, and shock at presentation. PMID:26787095

  15. Variant forms of the binary toxin CDT locus and tcdC gene in Clostridium difficile strains.

    Science.gov (United States)

    Stare, Barbara Geric; Delmée, Michel; Rupnik, Maja

    2007-03-01

    Variability in the genes for toxin A, toxin B and other pathogenicity locus regions is well known and is the basis for the distribution of Clostridium difficile strains into variant toxinotypes. Previous data have indicated that some C. difficile strains have a non-functional truncated form of the binary toxin (CDT) locus. This study analysed variability in the CDT locus and the presence of deleted tcdC genes in C. difficile strains. A total of 146 strains were screened, including known variant toxinotypes and non-variant A+B+ (toxinotype 0) and A-B- C. difficile strains. In all of the strains studied, only two forms of the CDT locus were found: a full-length 4.3 kb fragment encoding the functional binary toxin or a truncated 2.3 kb fragment. Whilst the full-length CDT locus was found almost exclusively in variant toxinotypes, the truncated form was detected in 79% of toxinotype 0 strains. Non-toxinogenic A-B- strains with a truncated version were not found and only rarely possessed the full-length CDT locus (A-B-CDT+ strains). Four different forms of the tcdC gene were found; three represented deleted versions and typically were found in toxinotypes III-VII, XI, XIV-XVI and XXIV. PMID:17314362

  16. Unfolded Protein Response Pathways in Bloodstream-Form Trypanosoma brucei?

    OpenAIRE

    Tiengwe, Calvin; Brown, Abigail E. N. A.; Bangs, James D.

    2015-01-01

    The unfolded protein response (UPR) is a stress mechanism to cope with misfolded proteins in the early secretory pathway, the hallmark being transcriptional upregulation of endoplasmic reticulum (ER) molecular chaperones such as BiP and protein disulfide isomerase. Despite the lack of transcriptional regulation and the absence of the classical UPR machinery, African trypanosomes apparently respond to persistent ER stress by a UPR-like response, including upregulation of BiP, and a related spl...

  17. Vancomycin-Resistant Enterococci (VRE) Bloodstream Infections In Hospitals, 2013

    Data.gov (United States)

    U.S. Department of Health & Human Services — This table shows the incidence rates of hospital onset (HO) vancomycin-resistant Enterococci bloodstream infections (VRE BSI) reported by California general acute...

  18. Central Line-Associated Bloodstream Infections (CLABSI) In Hospitals, 2013

    Data.gov (United States)

    U.S. Department of Health & Human Services — This table shows the Centers for Disease Control and Prevention National Healthcare Safety Network (NHSN) central line-associated bloodstream infection (CLABSI)...

  19. Bloodstream Infections with Mycobacterium tuberculosis among HIV patients

    Centers for Disease Control (CDC) Podcasts

    2010-09-23

    This podcast looks at bloodstream infections with Mycobacterium tuberculosis and other pathogens among outpatients infected with HIV in Southeast Asia. CDC health scientist Kimberly McCarthy discusses the study and why bloodstream infections occur in HIV-infected populations.  Created: 9/23/2010 by National Center for Emerging and Zoonotic Infectious Diseases (NCEZID).   Date Released: 9/23/2010.

  20. A simple method to purify biologically and antigenically preserved bloodstream trypomastigotes of Trypanosoma cruzi using Deae-cellulose columns

    OpenAIRE

    Maria Auxiliadora de Sousa

    1983-01-01

    A method to purify trypanosomastigotes of some strains of Trypanosoma cruzi (Y, CL, FL, F, "Berenice", "Colombiana" and "São Felipe") from mouse blood by using DEAE-cellulose columns was standardized. This procedure is a modification of the Lanham & Godfrey methods and differs in some aspects from others described to purify T. cruzi bloodstream trypomastigotes, mainly by avoidance of prior purifications of parasites. By this method, the broad trypomastigotes were mainly isolated, accounting f...

  1. FEM-based strain analysis study for multilayer sheet forming process

    Science.gov (United States)

    Zhang, Rongjing; Lang, Lihui; Zafar, Rizwan

    2015-12-01

    Fiber metal laminates have many advantages over traditional laminates (e.g., any type of fiber and resin material can be placed anywhere between the metallic layers without risk of failure of the composite fabric sheets). Furthermore, the process requirements to strictly control the temperature and punch force in fiber metal laminates are also less stringent than those in traditional laminates. To further explore the novel method, this study conducts a finite element method-based (FEM-based) strain analysis on multilayer blanks by using the 3A method. Different forming modes such as wrinkling and fracture are discussed by using experimental and numerical studies. Hydroforming is used for multilayer forming. The Barlat 2000 yield criteria and DYNAFORM/LS-DYNA are used for the simulations. Optimal process parameters are determined on the basis of fixed die-binder gap and variable cavity pressure. The results of this study will enhance the knowledge on the mechanics of multilayer structures formed by using the 3A method and expand its commercial applications.

  2. When Prostate Cancer Circulates in the Bloodstream

    Directory of Open Access Journals (Sweden)

    Virginie Vlaeminck-Guillem

    2015-10-01

    Full Text Available Management of patients with prostate cancer is currently based on imperfect clinical, biological, radiological and pathological evaluation. Prostate cancer aggressiveness, including metastatic potential, remains difficult to accurately estimate. In an attempt to better adapt therapeutics to an individual (personalized medicine, reliable evaluation of the intrinsic molecular biology of the tumor is warranted, and particularly for all tumor sites (primary tumors and secondary sites at any time of the disease progression. As a consequence of their natural tendency to grow (passive invasion or as a consequence of an active blood vessel invasion by metastase-initiating cells, tumors shed various materials into the bloodstream. Major efforts have been recently made to develop powerful and accurate methods able to detect, quantify and/or analyze all these circulating tumor materials: circulating tumors cells, disseminating tumor cells, extracellular vesicles (including exosomes, nucleic acids, etc. The aim of this review is to summarize current knowledge about these circulating tumor materials and their applications in translational research.

  3. Bloodstream infections after solid-organ transplantation.

    Science.gov (United States)

    Kritikos, Antonios; Manuel, Oriol

    2016-04-01

    Solid-organ transplantation (SOT) has become the preferred strategy to treat a number of end-stage organ disease, because a continuous improvement in survival and quality of life. While preventive strategies has decreased the risk for classical opportunistic infections (such as viral, fungal and parasite infections), bacterial infections, and particularly bloodstream infections (BSIs) remain the most common and life-threatening complications in SOT recipients. The source of BSI after transplant depends on the type of transplantation, being urinary tract infection, pneumonia, and intraabdominal infections the most common infections occurring after kidney, lung and liver transplantation, respectively. The risk for candidemia is higher in abdominal-organ than in thoracic-organ transplantation. Currently, the increasing prevalence of multi-drug resistant (MDR) Gram-negative pathogens, such as extended-spectrum betalactamase-producing Enterobacteriaciae and carbapenem-resistant Klebsiella pneumoniae, is causing particular concerns in SOT recipients, a population which presents several risk factors for developing infections due to MDR organisms. The application of strict preventive policies to reduce the incidence of post transplant BSIs and to control the spread of MDR organisms, including the implementation of specific stewardship programs to avoid the overuse of antibiotics and antifungal drugs, are essential steps to reduce the impact of post transplant infections on allograft and patient outcomes. PMID:26766415

  4. New antibiotic agents for bloodstream infections.

    Science.gov (United States)

    Vergidis, Paschalis I; Falagas, Matthew E

    2008-11-01

    Infections due to multidrug-resistant pathogens have shown a dramatic worldwide increase in prevalence. Bloodstream infections (BSIs) represent an important cause of morbidity and mortality in hospitalised patients. Research in the field led to the introduction of several novel antibiotic agents in the fight against bacterial pathogens. New antibiotics used against Gram-positive bacteria, mainly meticillin-resistant Staphylococcus aureus and vancomycin-resistant enterococci, include daptomycin, linezolid, quinupristin/dalfopristin and semisynthetic lipoglycopeptides. Among the Gram-negative bacteria, extended-spectrum beta-lactamase-producing Enterobacteriaceae as well as highly resistant Pseudomonas and Acinetobacter isolates are of particular concern. Doripenem is a recently approved carbapenem. Polymyxins are reconsidered as valuable therapeutic options for Gram-negative infections. Tigecycline, a glycylcycline, and ceftobiprole, a novel cephalosporin under investigation, have activity both against Gram-positive and Gram-negative organisms. In addition to the above agents, alternative treatment approaches that require further investigation have also been introduced into clinical practice. These include antibiotic lock therapy and continuous intravenous administration of antibiotics. In this article, we review the above treatment options for BSIs based on current clinical evidence. Comparative trials specifically focusing on patients with bacteraemia were generally not performed; however, a proportion of patients from the reported studies did have bacteraemia. PMID:18723329

  5. Numerical Investigation of the Limit Strains in Sheet Forming Involving Bending

    OpenAIRE

    BALAN, Tudor; ABED-MERAIM, Farid

    2008-01-01

    In this work, the finite element method is used to simulate a typical FLD test over tools of different radii. Parameters like the mesh density, element type, numerical determination of the onset of strain localization, limit strain definition etc. have been investigated. Finally, the limit strain for plane strain tension has been determined as a function of the thickness vs. tool radius (t/R) ratio. These simulations confirm that increasing the curvature of the tool increases the value of the...

  6. Histamine-producing Lactobacillus parabuchneri strains isolated from grated cheese can form biofilms on stainless steel.

    Science.gov (United States)

    Diaz, Maria; Del Rio, Beatriz; Sanchez-Llana, Esther; Ladero, Victor; Redruello, Begoña; Fernández, María; Martin, M Cruz; Alvarez, Miguel A

    2016-10-01

    The consumption of food containing large amounts of histamine can lead to histamine poisoning. Cheese is one of the most frequently involved foods. Histamine, one of the biogenic amines (BAs) exhibiting the highest safety risk, accumulates in food contaminated by microorganisms with histidine decarboxylase activity. The origin of these microorganisms may be very diverse with contamination likely occurring during post-ripening processing, but the microorganisms involved during this manufacturing step have never been identified. The present work reports the isolation of 21 histamine-producing Lactobacillus parabuchneri strains from a histamine-containing grated cheese. PCR revealed that every isolate carried the histidine decarboxylase gene (hdcA). Eight lineages were identified based on the results of genome PFGE restriction analysis plus endonuclease restriction profile analysis of the carried plasmids. Members of all lineages were able to form biofilms on polystyrene and stainless steel surfaces. L. parabuchneri is therefore an undesirable species in the dairy industry; the biofilms it can produce on food processing equipment represent a reservoir of histamine-producing bacteria and thus a source of contamination of post-ripening-processed cheeses. PMID:27375247

  7. Analysis of a strain rate field in cold formed material using the visioplasticity method

    Directory of Open Access Journals (Sweden)

    L. Gusel

    2009-04-01

    Full Text Available In this paper the visioplasticity method is used to find the complete velocity and strain rate distributions from the experimental data, using the finite-difference method. The data about values of strain rates in plastic region of the material is very important for calculating stresses and the prediction of product quality. Specimens of copper alloy were extruded with different lubricants and different coefficients of friction and then the strain rate distributions were analysed and compared. Significant differences in velocity and strain rate distributions were obtained in some regions at the exit of the deformed zone.

  8. Draft genome sequence of blaVeb-1, blaoxa-10producing multi-drug resistant (MDR Pseudomonas aeruginosastrain VRFPA09 recovered from bloodstream infection

    Directory of Open Access Journals (Sweden)

    Nandagopal Murugan

    2015-09-01

    Full Text Available Pseudomonas aeruginosa (P. aeruginosa bacteremia causes significant mortality rate due to emergence of multidrug resistant (MDR nosocomial infections. We report the draft genome sequence of P. aeruginosa strain VRFPA09, a human bloodstream isolate, phenotypically proven as MDR strain. Whole genome sequencing on VRFPA09, deciphered betalactamase encoding blaveb-1 and blaOXA-10genes and multiple drug resistance, virulence factor encoding genes.

  9. Genotypic analysis of Acinetobacter bloodstream infection isolates in a Turkish university hospital.

    NARCIS (Netherlands)

    Alp, E.; Esel, D.; Yildiz, O.; Voss, A.; Melchers, W.J.G.; Doganay, M.

    2006-01-01

    Acinetobacter baumannii is a significant pathogen of bloodstream infections in hospital patients that frequently causes single clone outbreaks. We aimed to evaluate the genetic relatedness and antimicrobial susceptibility of Acinetobacter spp. bloodstream isolates, in order to obtain insight into th

  10. Atypical Enteropathogenic Escherichia coli Strains form Biofilm on Abiotic Surfaces Regardless of Their Adherence Pattern on Cultured Epithelial Cells

    Directory of Open Access Journals (Sweden)

    Hebert F. Culler

    2014-01-01

    Full Text Available The aim of this study was to determine the capacity of biofilm formation of atypical enteropathogenic Escherichia coli (aEPEC strains on abiotic and biotic surfaces. Ninety-one aEPEC strains, isolated from feces of children with diarrhea, were analyzed by the crystal violet (CV assay on an abiotic surface after 24 h of incubation. aEPEC strains representing each HEp-2 cell type of adherence were analyzed after 24 h and 6, 12, and 18 days of incubation at 37°C on abiotic and cell surfaces by CFU/cm2 counting and confocal laser scanning microscopy (CLSM. Biofilm formation on abiotic surfaces occurred in 55 (60.4% of the aEPEC strains. There was no significant difference in biofilm biomass formation on an abiotic versus prefixed cell surface. The biofilms could be visualized by CLSM at various developmental stages. aEPEC strains are able to form biofilm on an abiotic surface with no association with their adherence pattern on HEp-2 cells with the exception of the strains expressing UND (undetermined adherence. This study revealed the capacity of adhesion and biofilm formation by aEPEC strains on abiotic and biotic surfaces, possibly playing a role in pathogenesis, mainly in cases of persistent diarrhea.

  11. Mortality in enterococcal bloodstream infections increases with inappropriate antimicrobial therapy

    DEFF Research Database (Denmark)

    Suppli, M.; Aabenhus, R.; Harboe, Z.B.;

    2010-01-01

    Enterococcus species are common in nosocomial bloodstream infections and their incidence is rising. Although well recognized in several serious bacterial infections, the influence of appropriate antimicrobial therapy in enterococcal bacteraemia has not been fully settled. The aim of the study was.......7-10), thrombocytopenia (3.9, 1.6-9.3), chronic liver failure (3.3, 1.1-10) and age >/=60 years (2.2, 0.99-5.0). Antibiotics not appropriately covering enterococci are frequently administered empirically in suspected bloodstream infections. Inappropriate antibiotic therapy was an independent risk factor for mortality in...

  12. Draft Genome Sequence of the Biofilm-Forming Stenotrophomonas maltophilia Strain 53.

    Science.gov (United States)

    Akbar, Sirwan; Rout, Simon P; Humphreys, Paul N

    2015-01-01

    A clinical strain of Stenotrophomonas maltophilia (designated strain 53) was obtained, and a whole-genome sequence was generated. The subsequent draft whole-genome sequence demonstrated the presence of a number of genes encoding for proteins involved in resistance to a number of antimicrobial therapies. PMID:25883296

  13. Trends in antibiotic susceptibility of bloodstream pathogens in hospitalized patients in France, 1996 to 2007.

    Science.gov (United States)

    Decousser, Jean-Winoc; Lamy, Brigitte; Pina, Patrick; Allouch, Pierre Yves

    2010-03-01

    Nationwide surveys of antimicrobial susceptibility of bacteria isolated from bloodstream infections are required to fit empiric therapy to recent trends and detect emerging resistance. We report the results of a French national prospective survey based on the College of Bacteriology-Virology and Hygiene study group network performed each October during the 1996 to 2007 period, with focus on Enterobacteriaceae (7708 isolates) and Staphylococcus aureus (2271 isolates). The most relevant antimicrobial susceptibilities trends were i) a decrease in fluoroquinolones susceptibility among Enterobacteriaceae (96-90%, P < 0.0001) and Escherichia coli isolates (98-89%, P < 0.0001), respectively, ii) the slight but significant decrease in cefotaxime susceptibility among E. coli (P = 0.016), and iii) the significant increase in gentamicin susceptibility among S. aureus strains (P = 0.016). This survey reports antibiotic susceptibility of bloodstream pathogens in France. The empiric use of fluoroquinolones in severe infections should be cautiously monitored by thorough clinical and microbiologic follow-up. PMID:19903587

  14. Physical model of the bloodstream systemic resistance of human

    Czech Academy of Sciences Publication Activity Database

    Chlup, Hynek; Konvičková, S.

    Praha : Czech Technical University in Prague, 2005, s. 806-807. ISBN 80-01-03201-9. [Workshop 2005 : Biomedical Engineering. Praha (CZ), 21.03.2005-25.03.2005] R&D Projects: GA ČR(CZ) GA106/04/1181 Institutional research plan: CEZ:AV0Z20760514 Keywords : system resistence * bloodstream * experimental lina Subject RIV: BO - Biophysics

  15. Polymicrobial Bloodstream Infection with Eggerthella lenta and Desulfovibrio desulfuricans ▿

    OpenAIRE

    Liderot, Karin; Larsson, Martin; Boräng, Stina; Özenci, Volkan

    2010-01-01

    The advancement in culture identification methods has made possible the culture and identification of slow-growing anaerobic bacteria in clinical samples. Here, we describe a case of polymicrobial bloodstream infection (BSI) caused by Eggerthella lenta and Desulfovibrio desulfuricans, identified by API 20A and Vitek 2 systems and by 16S rRNA sequencing.

  16. First Case of Bloodstream Infection Caused by Rhodococcus erythropolis▿

    OpenAIRE

    Baba, Hisashi; Nada, Toshi; Ohkusu, Kiyofumi; Ezaki, Takayuki; Hasegawa, Yoshinori; PATERSON, DAVID L.

    2009-01-01

    We describe the first case of bloodstream infection caused by Rhodococcus erythropolis. The identification was performed using 16S rRNA sequencing. This case illustrates that non-equi Rhodococcus infections may be underdiagnosed due to difficulties in identification in the routine clinical microbiology laboratory.

  17. Prevention of nosocomial bloodstream infections in preterm infants

    NARCIS (Netherlands)

    K. Helder MScN (Onno)

    2013-01-01

    textabstractProtecting patients from harm is the overarching theme of the studies presented here. More precisely, this thesis places a focus on the prevention of nosocomial or hospitalacquired bloodstream infections in preterm infants, thus saving them from further harm. A nosocomial infection is an

  18. Pichia farinosa Bloodstream Infection in a Lymphoma Patient▿

    OpenAIRE

    Adler, A.; Hidalgo-Grass, C.; Boekhout, T.; Theelen, B.; Sionov, E.; Polacheck, I

    2007-01-01

    We describe a case of Pichia farinosa bloodstream infection in a lymphoma patient. Phenotypic methods failed to identify the isolate, which was identified by sequence-based methods. This case highlights the importance of implementing molecular methods for the identification of rare fungal pathogens.

  19. In vivo cell aggregations of a recent swine biofilm-forming isolate of Leptospira interrogans strain from Argentina.

    Science.gov (United States)

    Brihuega, Bibiana; Samartino, Luis; Auteri, Carmelo; Venzano, Agustín; Caimi, Karina

    2012-01-01

    Leptospirosis is a zoonosis of ubiquitous distribution caused by spirochetes. Leptospires exist either as saprophytic water-associated organisms or as animal pathogens that can survive in water. Previous works have demonstrated that both saprophytic and pathogenic leptospires are able to produce functional biofilms, which consist of a community of bacteria embedded in an extracellular matrix attached to a surface. This structure is believed to provide protection from environmental aggressiveness. In the present study, we analyzed the capacity of biofilm formation both of a a recent field isolate of Leptospira interrogans serovar Pomona obtained from an aborted swine fetus and of the saprophytic Leptospira biflexa serovar Patoc. We used light microscopy, immunofluorescence, and scanning electron microscopic examinations on glass and polystyrene plate models to evaluate the process in vitro. The ability to form bacterial aggregations in vivo was tested using pregnant guinea pigs infected with both strains. We obtained biofilms both on glass and plastic surfaces. Scanning electron microscopic analysis showed differences in the biofilm structure formed by both strains. L. interrogans serovar Pomona cell aggregations were observed in placental tissues by light microscopy. Biofilms and cell aggregations are consistent with the life of saprophytic strains in water and could help pathogenic strains to colonize the host and lead to abortion in pregnant animals. PMID:23102459

  20. Comparison of Total Hospital-Acquired Bloodstream Infections to Central Line-Associated Bloodstream Infections and Implications for Outcome Measures in Infection Control

    OpenAIRE

    Leekha, Surbhi; Li, Shanshan; Thom, Kerri A.; Anne Preas, Michael; Caffo, Brian S.; Morgan, Daniel J.; Harris, Anthony D.

    2013-01-01

    Validity of the central line-associated bloodstream infection (CLABSI) measure is compromised by subjectivity. We observed significant decreases in both CLABSI and total hospital-acquired bloodstream infection (BSI) following a CLABSI prevention intervention in adult intensive care units. Total hospital-acquired BSI could be explored as an adjunct, objective CLABSI measure.

  1. Comparison of serum procalcitonin in respiratory infections and bloodstream infections

    OpenAIRE

    Zhu, Yanhui; Yuan, Yulin; Huang, Huayi

    2015-01-01

    Purpose: This study observed the relationship between procalcitonin (PCT) and results of sputum culture, the relationship between PCT and results of blood culture to evaluate and compare the value of PCT in respiratory and bloodstream infections. Methods: We analyzed 1616 patients in which PCT and sputum culture were concurrently ordered and analyzed, and 1096 patients in which PCT and blood culture were concurrently ordered and analyzed from January 2014 to May 2015. PCT concentrations were ...

  2. Candida bracarensis Bloodstream Infection in an Immunocompromised Patient ▿

    OpenAIRE

    Warren, Thomas A.; McTaggart, Lisa; Richardson, Susan E.; Zhang, Sean X.

    2010-01-01

    Candida bracarensis is a recently described Candida species which is phenotypically similar to Candida glabrata. A case of C. bracarensis bloodstream infection in a bone marrow transplant patient is described and confirms this organism as an opportunistic human pathogen. The organism can be distinguished from C. glabrata by its white color on CHROMagar and by DNA sequence analysis using D1/D2 and internal transcribed spacer (ITS) primers.

  3. Molecular Detection of Bloodstream Pathogens in Critical Illness

    OpenAIRE

    Al_griw, Huda Hm

    2012-01-01

    Background: Critically ill patients are at particular risk of developing bloodstream infection. Such infections are associated with the development of sepsis, leading to a marked increase in mortality rate. Early detection of the causative organism and appropriate antibiotic treatment are therefore critical for optimum outcome of patients with nosocomial infection. Current infection diagnosis is based on standard blood culture techniques. However, microbiological culture has a number of limi...

  4. Coordinated Molecular Cross-Talk between Staphylococcus aureus, Endothelial Cells and Platelets in Bloodstream Infection

    Directory of Open Access Journals (Sweden)

    Carolina D. Garciarena

    2015-12-01

    Full Text Available Staphylococcus aureus is an opportunistic pathogen often carried asymptomatically on the human body. Upon entry to the otherwise sterile environment of the cardiovascular system, S. aureus can lead to serious complications resulting in organ failure and death. The success of S. aureus as a pathogen in the bloodstream is due to its ability to express a wide array of cell wall proteins on its surface that recognise host receptors, extracellular matrix proteins and plasma proteins. Endothelial cells and platelets are important cells in the cardiovascular system and are a major target of bloodstream infection. Endothelial cells form the inner lining of a blood vessel and provide an antithrombotic barrier between the vessel wall and blood. Platelets on the other hand travel throughout the cardiovascular system and respond by aggregating around the site of injury and initiating clot formation. Activation of either of these cells leads to functional dysregulation in the cardiovascular system. In this review, we will illustrate how S. aureus establish intimate interactions with both endothelial cells and platelets leading to cardiovascular dysregulation.

  5. Forming Limit Prediction of Metastable Materials with Temperature and Strain Induced Martensite Transformation

    International Nuclear Information System (INIS)

    Stainless steels as well as TRIP and TWIP steels show a hardening behavior, which can be described only in dependency on the deformation and temperature history during the real forming process. Because the hardening behavior is the determinate factor for the necking phenomenon, the prediction of rupture becomes also deformation path and temperature dependent. As a consequence, the common FLC-method, using a single curve for the prediction of the failure state is not accurate enough. In this paper, a temperature dependent Forming Limit Surface (FLS) is presented

  6. MM99.70 - MODELS FOR FRICTION AND MATERIAL STRESS STRAIN HARDENING IN COLD FORMING

    DEFF Research Database (Denmark)

    Eriksen, Morten

    1999-01-01

    and tool temperature for four different combination of basic material, conversion layer and lubricant. Furthermore flow stress curves for aluminium, steel and stainless steel are given at varying slug temperatures in the range which can be reached in cold forming (25-200C).The documentation is...

  7. Stress-strain Relationship of Cold-formed Lean Duplex Stainless Steel at Elevated Temperatures

    OpenAIRE

    Young, B; Huang, Y.

    2014-01-01

    A test programme to examine the material properties of a relatively new cold-formed lean duplex stainless steel at elevated temperatures is presented. A total of 80 tensile coupon tests were carried out by both steady state test method and transient state test method for temperatures ranged from 24 to 900 °C. The coupons were extracted from square and rectangular hollow sections. Material properties including thermal elongation, Young's modulus, yield strength, ultimate strength and ultimate ...

  8. On the modelling of complex kinematic hardening and nonquadratic anisotropic yield criteria at finite strains: application to sheet metal forming

    Science.gov (United States)

    Grilo, Tiago J.; Vladimirov, Ivaylo N.; Valente, Robertt A. F.; Reese, Stefanie

    2016-06-01

    In the present paper, a finite strain model for complex combined isotropic-kinematic hardening is presented. It accounts for finite elastic and finite plastic strains and is suitable for any anisotropic yield criterion. In order to model complex cyclic hardening phenomena, the kinematic hardening is described by several back stress components. To that end, a new procedure is proposed in which several multiplicative decompositions of the plastic part of the deformation gradient are considered. The formulation incorporates a completely general format of the yield function, which means that any yield function can by employed by following a procedure that ensures the principle of material frame indifference. The constitutive equations are derived in a thermodynamically consistent way and numerically integrated by means of a backward-Euler algorithm based on the exponential map. The performance of the constitutive model is assessed via numerical simulations of industry-relevant sheet metal forming processes (U-channel forming and draw/re-draw of a panel benchmarks), the results of which are compared to experimental data. The comparison between numerical and experimental results shows that the use of multiple back stress components is very advantageous in the description of springback. This holds in particular if one carries out a comparison with the results of using only one component. Moreover, the numerically obtained results are in excellent agreement with the experimental data.

  9. Neonatal bloodstream infections in a pediatric hospital in Vietnam

    DEFF Research Database (Denmark)

    Kruse, Alexandra Yasmin; Thieu Chuong, D.H.; Phuong, C.N.; Duc, T.; Graff Stensballe, L.; Prag, J.; Kurtzhals, Jørgen; Greisen, Gorm; Pedersen, Freddy Karup

    2013-01-01

    Septicemia and bloodstream infections (BSIs) are major causes of neonatal morbidity and mortality in developing countries. We prospectively recorded all positive blood cultures (BSI) among neonates admitted consecutively to a tertiary pediatric hospital in Vietnam during a 12-month period. Among...... 5763 neonates, 2202 blood cultures were performed, of which 399 were positive in 385 neonates. Among these, 64 died, 62 in relation to septicemia. Of the BSI isolates, 56% was known pathogenic and 48% was gram-negative bacteria, most frequently Klebsiella spp. (n = 78), Acinetobacter spp. (n = 58) and...

  10. Bloodstream-To-Eye Infections Are Facilitated by Outer Blood-Retinal Barrier Dysfunction

    Science.gov (United States)

    Coburn, Phillip S.; Wiskur, Brandt J.; Miller, Frederick C.; LaGrow, Austin L.; Astley, Roger A.; Elliott, Michael H.; Callegan, Michelle C.

    2016-01-01

    The blood-retinal barrier (BRB) functions to maintain the immune privilege of the eye, which is necessary for normal vision. The outer BRB is formed by tightly-associated retinal pigment epithelial (RPE) cells which limit transport within the retinal environment, maintaining retinal function and viability. Retinal microvascular complications and RPE dysfunction resulting from diabetes and diabetic retinopathy cause permeability changes in the BRB that compromise barrier function. Diabetes is the major predisposing condition underlying endogenous bacterial endophthalmitis (EBE), a blinding intraocular infection resulting from bacterial invasion of the eye from the bloodstream. However, significant numbers of EBE cases occur in non-diabetics. In this work, we hypothesized that dysfunction of the outer BRB may be associated with EBE development. To disrupt the RPE component of the outer BRB in vivo, sodium iodate (NaIO3) was administered to C57BL/6J mice. NaIO3-treated and untreated mice were intravenously injected with 108 colony forming units (cfu) of Staphylococcus aureus or Klebsiella pneumoniae. At 4 and 6 days postinfection, EBE was observed in NaIO3-treated mice after infection with K. pneumoniae and S. aureus, although the incidence was higher following S. aureus infection. Invasion of the eye was observed in control mice following S. aureus infection, but not in control mice following K. pneumoniae infection. Immunohistochemistry and FITC-dextran conjugate transmigration assays of human RPE barriers after infection with an exoprotein-deficient agr/sar mutant of S. aureus suggested that S. aureus exoproteins may be required for the loss of the tight junction protein, ZO-1, and for permeability of this in vitro barrier. Our results support the clinical findings that for both pathogens, complications which result in BRB permeability increase the likelihood of bacterial transmigration from the bloodstream into the eye. For S. aureus, however, BRB permeability is

  11. Bloodstream-To-Eye Infections Are Facilitated by Outer Blood-Retinal Barrier Dysfunction.

    Directory of Open Access Journals (Sweden)

    Phillip S Coburn

    Full Text Available The blood-retinal barrier (BRB functions to maintain the immune privilege of the eye, which is necessary for normal vision. The outer BRB is formed by tightly-associated retinal pigment epithelial (RPE cells which limit transport within the retinal environment, maintaining retinal function and viability. Retinal microvascular complications and RPE dysfunction resulting from diabetes and diabetic retinopathy cause permeability changes in the BRB that compromise barrier function. Diabetes is the major predisposing condition underlying endogenous bacterial endophthalmitis (EBE, a blinding intraocular infection resulting from bacterial invasion of the eye from the bloodstream. However, significant numbers of EBE cases occur in non-diabetics. In this work, we hypothesized that dysfunction of the outer BRB may be associated with EBE development. To disrupt the RPE component of the outer BRB in vivo, sodium iodate (NaIO3 was administered to C57BL/6J mice. NaIO3-treated and untreated mice were intravenously injected with 108 colony forming units (cfu of Staphylococcus aureus or Klebsiella pneumoniae. At 4 and 6 days postinfection, EBE was observed in NaIO3-treated mice after infection with K. pneumoniae and S. aureus, although the incidence was higher following S. aureus infection. Invasion of the eye was observed in control mice following S. aureus infection, but not in control mice following K. pneumoniae infection. Immunohistochemistry and FITC-dextran conjugate transmigration assays of human RPE barriers after infection with an exoprotein-deficient agr/sar mutant of S. aureus suggested that S. aureus exoproteins may be required for the loss of the tight junction protein, ZO-1, and for permeability of this in vitro barrier. Our results support the clinical findings that for both pathogens, complications which result in BRB permeability increase the likelihood of bacterial transmigration from the bloodstream into the eye. For S. aureus, however, BRB

  12. BIOSORPTION OF CHROMIUM (VI) FROM INDUSTRIAL EFFLUENT BY WILD ANDMUTANT TYPE STRAIN OF SACCHAROMYCES CEREVISIAE AND ITS IMMOBILIZED FORM

    OpenAIRE

    K Selvam, K Arungandhi, B Vishnupriya, T Shanmuga priya and M Yamuna

    2013-01-01

    Biosorption of chromium was studied by wild type Saccharomyces cerevisiae strain, mutant strain, immobilized-wild type and mutant strain. Chromium absorption pattern was observed in all experimental conditions. Hexavalent chromium (VI) was analyzed by diphenyl carbazide method, by oxidizing the trivalent chromium (III). The percentage efficiency of wild type S. cerevisiae and its mutant strain, immobilized-wild type and mutant strain were 94.8%, 98.7%, 97.4% and 100% respectively. S. cerevisi...

  13. [The detection of occurrence rate of genes coding capability to form pili binding in auto-strains of Escherichia coli].

    Science.gov (United States)

    Ivanova, E I; Popkova, S M; Dzhioev, Iu P; Rakova, E B; Dolgikh, V V; Savel'kaeva, M V; Nemchenko, U M; Bukharova, E V; Serdiuk, L V

    2015-01-01

    E. coli is a commensal of intestine of the vertebrata. The exchange of genetic material of different types of bacteria between themselves and with other representatives of family of Enterobacteriaceae in intestinal ecosystem results in development of types of normal colibacillus with genetic characteristics of pathogenicity that can serve as a theoretical substantiation to attribute such strains to pathobionts. The entero-pathogenic colibacillus continues be an important cause of diarrhea in children in developing countries. The gene responsible for formation of pili binding is a necessary condition for virulence of entero-pathogenic colibacillus. The polymerase chain reaction was applied to examine 316 strains of different types of E. coli (normal, with weak enzyme activity and hemolytic activity) isolated from healthy children and children with functional disorders of gastro-intestinal tract for presence of genes coding capability to form pill binding. The presence of this gene in different biochemical types of E. coli permits to establish the fact of formation of reservoir of pathogenicity in indigent microbiota of intestinal biocenosis. PMID:25874306

  14. Cytosolic peroxidases protect the lysosome of bloodstream African trypanosomes from iron-mediated membrane damage.

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    Corinna Hiller

    2014-04-01

    Full Text Available African trypanosomes express three virtually identical non-selenium glutathione peroxidase (Px-type enzymes which preferably detoxify lipid-derived hydroperoxides. As shown previously, bloodstream Trypanosoma brucei lacking the mitochondrial Px III display only a weak and transient proliferation defect whereas parasites that lack the cytosolic Px I and Px II undergo extremely fast lipid peroxidation and cell lysis. The phenotype can completely be rescued by supplementing the medium with the α-tocopherol derivative Trolox. The mechanism underlying the rapid cell death remained however elusive. Here we show that the lysosome is the origin of the cellular injury. Feeding the px I-II knockout parasites with Alexa Fluor-conjugated dextran or LysoTracker in the presence of Trolox yielded a discrete lysosomal staining. Yet upon withdrawal of the antioxidant, the signal became progressively spread over the whole cell body and was completely lost, respectively. T. brucei acquire iron by endocytosis of host transferrin. Supplementing the medium with iron or transferrin induced, whereas the iron chelator deferoxamine and apo-transferrin attenuated lysis of the px I-II knockout cells. Immunofluorescence microscopy with MitoTracker and antibodies against the lysosomal marker protein p67 revealed that disintegration of the lysosome precedes mitochondrial damage. In vivo experiments confirmed the negligible role of the mitochondrial peroxidase: Mice infected with px III knockout cells displayed only a slightly delayed disease development compared to wild-type parasites. Our data demonstrate that in bloodstream African trypanosomes, the lysosome, not the mitochondrion, is the primary site of oxidative damage and cytosolic trypanothione/tryparedoxin-dependent peroxidases protect the lysosome from iron-induced membrane peroxidation. This process appears to be closely linked to the high endocytic rate and distinct iron acquisition mechanisms of the infective

  15. The influence of deformation-induced residual stresses on the post-forming tensile stress/strain behavior of dual-phase steels

    Science.gov (United States)

    Hance, Brandon Michael

    It was hypothesized that, in dual-phase (DP) steels, strain partitioning between ferrite (alpha) and martensite (alpha') during deformation results in a distribution of post-deformation residual stresses that, in turn, affects the subsequent strength, work hardening behavior and formability when the strain path is changed. The post-forming deformation-induced residual stress state was expected to depend upon the microstructure, the amount of strain and the prestrain path. The primary objective of this research program was to understand the influence of deformation-induced residual stresses on the post-forming tensile stress/strain behavior of DP steels. Three commercially produced sheet steels were considered in this analysis: (1) a DP steel with approximately 15 vol. % martensite, (2) a conventional high-strength, low-alloy (HSLA) steel, and (3) a conventional, ultra-low-carbon interstitial-free (IF) steel. Samples of each steel were subjected to various prestrain levels in various plane-stress forming modes, including uniaxial tension, plane strain and balanced biaxial stretching. Neutron diffraction experiments confirmed the presence of large post-forming deformation-induced residual stresses in the ferrite phase of the DP steel. The deformation-alphainduced residual stress state varied systematically with the prestrain mode, where the principal residual stress components are proportional to the principal strain components of the prestrain mode, but opposite in sign. For the first time, and by direct experimental correlation, it was shown that deformation-induced residual stresses greatly affect the post-forming tensile stress/strain behavior of DP steels. As previously reported in the literature, the formability (residual tensile ductility) of the IF steel and the HSLA steel was adversely affected by strain path changes. The DP steel presents a formability advantage over the conventional IF and HSLA steels, and is expected to be particularly well suited for

  16. Emerging commercial molecular tests for the diagnosis of bloodstream infection.

    Science.gov (United States)

    Mwaigwisya, Solomon; Assiri, Rasha Assad M; O'Grady, Justin

    2015-05-01

    Bloodstream infection (BSI) by microorganisms can lead to sepsis. This condition has a high mortality rate, which rises significantly with delays in initiation of appropriate antimicrobial treatment. Current culture methods for diagnosing BSI have long turnaround times and poor clinical sensitivity. While clinicians wait for culture diagnosis, patients are treated empirically, which can result in inappropriate treatment, undesirable side effects and contribute to drug resistance development. Molecular diagnostics assays that target pathogen DNA can identify pathogens and resistance markers within hours. Early diagnosis improves antibiotic stewardship and is associated with favorable clinical outcomes. Nonetheless, limitations of current molecular diagnostic methods are substantial. This article reviews recent commercially available molecular methods that use pathogen DNA to diagnose BSI, either by testing positive blood cultures or directly testing patient blood. We critically assess these tests and their application in clinical microbiology. A view of future directions in BSI diagnosis is also provided. PMID:25866124

  17. Staphylococcus species and their Methicillin-Resistance in 7424 Blood Cultures for Suspected Bloodstream Infections

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    Ariana ALMAŞ

    2011-06-01

    Full Text Available Objectives: The aim of this study was to evaluate the distribution of Staphylococcus species in bloodstream infections and to assess their susceptibility to methicillin. Material and Methods: Between January 1st 2008 - December 31st 2010, 7424 blood culture sets were submitted to the Laboratory Department of the Hospital for Clinical Infectious Diseases in Cluj-Napoca, Romania. The blood cultures were performed using BacT/Alert until January 2010 and BacT/Alert 3D automated system (bioMérieux after that date. The blood culture bottles were incubated at 37°C in a continuously monitoring system for up to 7 days. The strain identifications were performed by conventional methods, ApiStaph galleries and Vitek 2 Compact system. Susceptibility to methicillin was determined by disk diffusion method with cefoxitin disk and by using Vitek 2 Compact system. Results: From the total number of performed blood cultures, 568 were positive with Staphylococcus species. From 168 bacteriemic episodes 103 were with Staphylococcus aureus. Among 65 coagulase-negative staphylococci isolates, Staphylococcus epidermidis was the most frequently isolated species (34, followed by Staphylococcus hominis (15, Staphylococcus haemolyticus (8, Staphylococcus saprophyticus (3, Staphylococcus cohnii (1, Staphylococcus auricularis (1, and 3 strains that were not identified at species level. Methicillin resistance was encountered in 53.40% of Staphylococcus aureus strains and in 80% of coagulase-negative staphylococci. Conclusions: An important percentage of blood cultures were contaminated with Staphylococcus species. The main species identified in true bacteriemia cases were Staphylococcus aureus and Staphylococcus epidermidis. The percentage of methicillin-resistance, proved to be high not only for coagulase-negative staphylococci but also for Staphylococcus aureus.

  18. Cefotaxime resistance and outcome of Klebsiella spp bloodstream infection.

    Science.gov (United States)

    Ortega, M; Marco, F; Soriano, A; Almela, M; Martínez, J A; López, J; Pitart, C; Mensa, J

    2011-12-01

    We attempt to describe the epidemiology and outcome associated with cefotaxime-resistant (CTX-R) Klebsiella spp bacteraemia. Klebsiella spp bloodstream infection episodes prospectively collected through a blood culture surveillance programme from January 1991 to December 2008 in a single institution were analysed. A total of 910 monomicrobial episodes of Klebsiella spp bacteraemia were identified during the study period. The most important sources were from urinary tract infection, unknown sources, billiary focus and catheter related infection. There were 112 (12%) CTX-R isolates. Out of 112 isolates, 98 were CTX-R by Extended-Spectrum β-Lactamase production. Shock on presentation and mortality were significantly more frequent in CTX-R than in CTX susceptible isolates. Inappropriate empirical therapy was received in 50 (45%) cases in the CTX-R Klebsiella spp group (13 cases of death, 26%). Predictive factors associated with CTX-R Klebsiella spp isolate were: previous β-lactam therapy (OR = 4.16), nosocomial acquired bacteraemia (OR = 1.93), solid organ trasplantation (OR = 2.09) and shock (OR = 1.90). Independent risk factors associated with mortality in Klebsiella spp bacteraemia were: age (OR = 1.03), liver cirrhosis (OR = 2.63), ultimately or rapidly fatal prognosis of underlying disease (OR = 2.44), shock (OR = 8.60), pneumonia (OR = 4.96) or intraabdominal (OR = 3.85) source of bacteraemia and CTX-R isolate (OR = 4.63). Klebsiella spp is an important cause of bloodstream infection. CTX-R isolates have been increasing since 2000. CTX-R is an independent factor associated with mortality in Klebsiella spp bacteraemia. PMID:21509474

  19. The first reported catheter-related Brevibacterium casei bloodstream infection in a child with acute leukemia and review of the literature.

    Science.gov (United States)

    Bal, Zumrut Sahbudak; Sen, Semra; Karapinar, Deniz Yilmaz; Aydemir, Sohret; Vardar, Fadil

    2015-01-01

    Brevibacterium spp. are catalase-positive, non-spore-forming, non motile, aerobic Gram-positive rods that were considered apathogenic until a few reports of infections in immunocompromised patients had been published. To the best of our knowledge, this is the first report of B. casei catheter-related bloodstream infection in a child with acute leukemia. We aim to enhance the awareness of pediatric hematology and infectious disease specialists about this pathogen and review of the literature. PMID:25636191

  20. The first reported catheter-related Brevibacterium casei bloodstream infection in a child with acute leukemia and review of the literature

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    Zumrut Sahbudak Bal

    2015-04-01

    Full Text Available Brevibacteriumspp. are catalase-positive, non-spore-forming, non motile, aerobic Gram- positive rods that were considered apathogenic until a few reports of infections in immunocompromised patients had been published. To the best of our knowledge, this is the first report of B. caseicatheter-related bloodstream infection in a child with acute leukemia. We aim to enhance the awareness of pediatric hematology and infectious disease specialists about this pathogen and review of the literature.

  1. Antimicrobial resistance predicts death in Tanzanian children with bloodstream infections: a prospective cohort study

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    Msangi Viola

    2007-05-01

    Full Text Available Abstract Background Bloodstream infection is a common cause of hospitalization, morbidity and death in children. The impact of antimicrobial resistance and HIV infection on outcome is not firmly established. Methods We assessed the incidence of bloodstream infection and risk factors for fatal outcome in a prospective cohort study of 1828 consecutive admissions of children aged zero to seven years with signs of systemic infection. Blood was obtained for culture, malaria microscopy, HIV antibody test and, when necessary, HIV PCR. We recorded data on clinical features, underlying diseases, antimicrobial drug use and patients' outcome. Results The incidence of laboratory-confirmed bloodstream infection was 13.9% (255/1828 of admissions, despite two thirds of the study population having received antimicrobial therapy prior to blood culture. The most frequent isolates were klebsiella, salmonellae, Escherichia coli, enterococci and Staphylococcus aureus. Furthermore, 21.6% had malaria and 16.8% HIV infection. One third (34.9% of the children with laboratory-confirmed bloodstream infection died. The mortality rate from Gram-negative bloodstream infection (43.5% was more than double that of malaria (20.2% and Gram-positive bloodstream infection (16.7%. Significant risk factors for death by logistic regression modeling were inappropriate treatment due to antimicrobial resistance, HIV infection, other underlying infectious diseases, malnutrition and bloodstream infection caused by Enterobacteriaceae, other Gram-negatives and candida. Conclusion Bloodstream infection was less common than malaria, but caused more deaths. The frequent use of antimicrobials prior to blood culture may have hampered the detection of organisms susceptible to commonly used antimicrobials, including pneumococci, and thus the study probably underestimates the incidence of bloodstream infection. The finding that antimicrobial resistance, HIV-infection and malnutrition predict fatal

  2. Biofilm formation is a risk factor for mortality in patients with Candida albicans bloodstream infection-Scotland, 2012-2013.

    Science.gov (United States)

    Rajendran, R; Sherry, L; Nile, C J; Sherriff, A; Johnson, E M; Hanson, M F; Williams, C; Munro, C A; Jones, B J; Ramage, G

    2016-01-01

    Bloodstream infections caused by Candida species remain a significant cause of morbidity and mortality in hospitalized patients. Biofilm formation by Candida species is an important virulence factor for disease pathogenesis. A prospective analysis of patients with Candida bloodstream infection (n = 217) in Scotland (2012-2013) was performed to assess the risk factors associated with patient mortality, in particular the impact of biofilm formation. Candida bloodstream isolates (n = 280) and clinical records for 157 patients were collected through 11 different health boards across Scotland. Biofilm formation by clinical isolates was assessed in vitro with standard biomass assays. The role of biofilm phenotype on treatment efficacy was also evaluated in vitro by treating preformed biofilms with fixed concentrations of different classes of antifungal. Available mortality data for 134 patients showed that the 30-day candidaemia case mortality rate was 41%, with predisposing factors including patient age and catheter removal. Multivariate Cox regression survival analysis for 42 patients showed a significantly higher mortality rate for Candida albicans infection than for Candida glabrata infection. Biofilm-forming ability was significantly associated with C. albicans mortality (34 patients). Finally, in vitro antifungal sensitivity testing showed that low biofilm formers and high biofilm formers were differentially affected by azoles and echinocandins, but not by polyenes. This study provides further evidence that the biofilm phenotype represents a significant clinical entity, and that isolates with this phenotype differentially respond to antifungal therapy in vitro. Collectively, these findings show that greater clinical understanding is required with respect to Candida biofilm infections, and the implications of isolate heterogeneity. PMID:26432192

  3. Microbiologic characterization of isolates from a dalbavancin clinical trial for catheter-related bloodstream infections.

    Science.gov (United States)

    Goldstein, Beth P; Jones, Ronald N; Fritsche, Thomas R; Biedenbach, Douglas J

    2006-02-01

    Dalbavancin, a new-generation semisynthetic lipoglycopeptide in phase 3 clinical development, has been documented to be more active than vancomycin or teicoplanin against Gram-positive bacteria, including multidrug-resistant strains, by in vitro testing and in animal models. The human pharmacokinetics of dalbavancin predicts efficacy at weekly dosing intervals. In a phase 2 open-label clinical trial, dalbavancin exhibited superiority when compared with vancomycin against catheter-related bloodstream infection (CR-BSI). The majority of pathogens identified in this study as in clinical practice were coagulase-negative staphylococci (CoNS), necessitating rigorous characterization of duplicate isolates to rule out contaminants and to validate cases for study evaluations. At follow-up for the intent-to-treat population, overall pathogen eradication was 92.3% for dalbavancin and 75.9% for vancomycin. We describe the details of organisms isolated, their epidemiologic/genetic characterization, susceptibility patterns against glycopeptides, and the eradication rates by organism group. In conclusion, dalbavancin was active against all isolated pathogens associated with CR-BSI (CoNS, Staphylococcus aureus and Enterococcus faecalis; all MIC results, < or = 0.25 microg/mL) and achieved significant (P < 0.05) clinical success when compared with vancomycin. PMID:16458124

  4. Species distribution and antifungal susceptibility profile of Candida spp. bloodstream isolates from Latin American hospitals

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    Patrício Godoy

    2003-04-01

    Full Text Available From March 1999 to March 2000, we conducted a prospective multicenter study of candidemia involving five tertiary care hospitals from four countries in Latin America. Yeast isolates were identified by classical methods and the antifungal susceptibility profile was determined according to the National Committee for Clinical Laboratory Standards microbroth assay method. During a 12 month-period we were able to collect a total of 103 bloodstream isolates of Candida spp. C. albicans was the most frequently isolated species accounting for 42% of all isolates. Non-albicans Candida species strains accounted for 58% of all episodes of candidemia and were mostly represented by C. tropicalis (24.2% and C. parapsilosis (21.3%. It is noteworthy that we were able to identify two cases of C. lusitaniae from different institutions. In our casuistic, non-albicans Candida species isolates related to candidemic episodes were susceptible to fluconazole. Continuously surveillance programs are needed in order to identify possible changes in the species distribution and antifungal susceptibility patterns of yeasts that may occurs after increasing the use of azoles in Latin American hospitals.

  5. Bloodstream infections caused by multi-drug resistant Proteus mirabilis: Epidemiology, risk factors and impact of multi-drug resistance.

    Science.gov (United States)

    Korytny, Alexander; Riesenberg, Klaris; Saidel-Odes, Lisa; Schlaeffer, Fransisc; Borer, Abraham

    2016-06-01

    Background The prevalence of antimicrobial co-resistance among ESBL-producing Enterobactereaceae is extremely high in Israel. Multidrug-resistant Proteus mirabilis strains (MDR-PM), resistant to almost all antibiotic classes have been described. The aim was to determine the risk factors for bloodstream infections caused by MDR-PM and clinical outcomes. Methods A retrospective case-control study. Adult patients with PM bacteremia during 7 years were identified retrospectively and their files reviewed for demographics, underlying diseases, Charlson Comorbidity Index, treatment and outcome. Results One hundred and eighty patients with PM-bloodstream infection (BSI) were included; 90 cases with MDR-PM and 90 controls with sensitive PM (S-PM). Compared to controls, cases more frequently were from nursing homes, had recurrent hospital admissions in the past year and received antibiotic therapy in the previous 3 months, were bedridden and suffered from peripheral vascular disease and peptic ulcer disease (p < 0.001). Two-thirds of the MDR-PM isolates were ESBL-producers vs 4.4% of S-PM isolates (p < 0.001, OR = 47.6, 95% CI = 15.9-142.6). In-hospital crude mortality rate of patients with MDR-PM BSI was 37.7% vs 23.3% in those with S-PM BSI (p = 0.0359, OR = 2, 95% CI = 1.4-3.81). Conclusions PM bacteremia in elderly and functionally-dependent patients is likely to be caused by nearly pan-resistant PM strains in the institution; 51.8% of the patients received inappropriate empiric antibiotic treatment. The crude mortality rate of patients with MDR-PM BSI was significantly higher than that of patients with S-PM BSI. PMID:26763474

  6. Catheter Removal versus Retention in the Management of Catheter-Associated Enterococcal Bloodstream Infections

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    Jonas Marschall

    2013-01-01

    Full Text Available BACKGROUND: Enterococci are an important cause of central venous catheter (CVC-associated bloodstream infections (CA-BSI. It is unclear whether CVC removal is necessary to successfully manage enterococcal CA-BSI.

  7. Prevalence of blaZ Gene Types and the Inoculum Effect with Cefazolin among Bloodstream Isolates of Methicillin-Susceptible Staphylococcus aureus

    OpenAIRE

    Livorsi, D. J.; Crispell, E.; Satola, S. W.; Burd, E. M.; Jerris, R.; Wang, Y.F.(Institute of High Energy Physics, Beijing, 100049, People's Republic of China); Farley, M M

    2012-01-01

    We sought to define the prevalence of blaZ gene types and the inoculum effect to cefazolin among methicillin-susceptible Staphylococcus aureus (MSSA) bloodstream infections. The blaZ gene was present in 142/185 (77%) isolates. A total of 50 (27%) isolates had a ≥4-fold increase in the cefazolin MIC from a standard to a high inoculum, and 8 (4%) demonstrated a nonsusceptible cefazolin MIC, all type A blaZ strains. The efficacy of cefazolin in the presence of the inoculum effect requires furthe...

  8. The Changing Epidemiology of Bloodstream Infections and Resistance in Hematopoietic Stem Cell Transplantation Recipients

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    Mücahit Yemişen

    2016-08-01

    Full Text Available Objective: Patients receiving hematopoietic stem cell transplantation (HSCT are exposed to highly immunosuppressive conditions and bloodstream infections (BSIs are one of the most common major complications within this period. Our aim, in this study, was to evaluate the epidemiology of BSIs in these patients retrospectively. Materials and Methods: The epidemiological properties of 312 patients with HSCT were retrospectively evaluated. Results: A total of 312 patients, followed between 2000 and 2011, who underwent autologous (62% and allogeneic (38% HSCT were included in the study. The most common underlying malignancies were multiple myeloma (28% and Hodgkin lymphoma (21.5%. A total of 142 (45% patients developed at least 1 episode of BSI and 193 separate pathogens were isolated from the blood cultures. There was a trend of increase in the numbers of BSIs in 2005-2008 and a relative increase in the proportion of gram-positive infections in recent years (2009-2011, and central venous catheter-related BSI was found to be most common source. Coagulase-negative staphylococci (49.2% and Acinetobacter baumannii (8.8% were the most common pathogens. Extended-spectrum beta-lactamase-producing strains were 23% and 22% among Escherichia coli and Klebsiella spp. isolates, respectively. Quinolone resistance was detected in 10% of Enterobacteriaceae. Resistance to carbapenems was not detected in Enterobacteriaceae, while it was seen at 11.1% and 23.5% in Pseudomonas and Acinetobacter strains, respectively. Conclusion: A shift was detected from gram-negative bacteria to gram-positive in the etiology over the years and central lines were the most common sources of BSIs.

  9. The investigation of new forms of resistance to some antibiotics in E coli strains isolated from piglets

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    Ašanin Ružica

    2009-01-01

    Full Text Available The resistance of bacteria poses a significant problem everywhere in the world, and consequently in our country as well. The non-critical use of antibacterial medicines in human and veterinary medicine has contributed to the spreading of this resistance. Due to the topical importance of this problem, large numbers of states in the world are financing projects of which the objective is to follow and monitor bacterial resistance. The objective of this investigation was to isolate and identify pathogenic strains of E. coli from piglets with clinically manifest diarrhea and to examine the sensitivity of the isolated strains to a certain number of selected antibiotics. The material for these investigations were parts of intestines (jejunum, ileum from piglets that died, rectal smears and feces of diseased piglets sampled pig farms in the vicinity of Belgrade. Conventional methods of microbiological diagnostics were used for isolation, and conventional and commercial tests API 20E (bio Merieux, France were used for identification. Following biochemical identification using hyper immune serums for certain group (O antigens: (O8, O138, O139, O147, O149, and O157, the serological typization of the strains was carried out. Commercial antiserums: T K88 (F4, K99 (F5, and 987P (F6, Toxigenic E. coli pili antisera, Denka Seiken Co. Ltd. Tokyo, Japan were used to establish the presence and to identify fimbrial antigens-adhesions through slide agglutination reaction. The sensitivity of the antibiotics to the isolated strains of E. coli was examined using the disc diffusion method according to Kirby Bauer and the microdillution method in bouillon according to CLSI recommendations (2008. Examinations using the microdillution method in bouillon were performed with pure active antibiotic substances: ampicillin, apramycin, gentamicin, kanamycin, tetracycline, ceftriaxone, and ciprofloxacin (Sigma, USA. A total of 400 E. coli strains were isolated, including 48 E

  10. Bloodstream infections related to totally implantable venous access port: What is the situation in our hospital?

    OpenAIRE

    Desgranges F.

    2012-01-01

    Port-a-Cath© (PAC) are totally implantable devices that offer an easy and long term access to venous circulation. They have been extensively used for intravenous therapy administration and are particularly well suited for chemotherapy in oncologic patients. Previous comparative studies have shown that these devices have the lowest catheter-related bloodstream infection rates among all intravascular access systems. However, bloodstream infection (BSI) still remains a major issue of port use an...

  11. Infectious Complications and Morbidities After Neonatal Bloodstream Infections

    Science.gov (United States)

    Tsai, Ming-Horng; Lee, Chiang-Wen; Chu, Shih-Ming; Lee, I-Ta; Lien, Reyin; Huang, Hsuan-Rong; Chiang, Ming-Chou; Fu, Ren-Huei; Hsu, Jen-Fu; Huang, Yhu-Chering

    2016-01-01

    Abstract Few data are available on the clinical characteristics of complications and morbidities after neonatal bloodstream infections (BSIs), understood as any newly infectious focus or organ dysfunction directly related to BSIs but not occur concurrently. However, these bloodstream-associated infectious complications (BSICs) contribute significantly to increased hospital stay, cost, and final mortality. We performed an observational cohort study of unselected neonatal intensive care unit (NICU) patients based on records in a large clinical database. All neonates hospitalized in our NICU with BSI between 2006 and 2013 were reviewed, and those who developed BSICs were analyzed to identify the clinical characteristics and outcomes. Multivariate logistic regression was used to identify independent risk factors for BSICs. Of 975 episodes of neonatal BSI, 101 (10.4%) BSICs occurred in 93 neonates with a median interval of 3 days (range, 0–17 days) after onset of BSI and included newly infectious focuses in 40 episodes (39.6%), major organ dysfunctions after septic shock in 36 episodes (35.6%), and neurological complications after meningitis or septic shock in 34 episodes (33.7%). All patients with BSICs encountered various morbidities, which subsequently resulted in in-hospital death in 30 (32.3%) neonates, critical discharge in 4 (4.3%), and persistent sequelae in 17 (18.3%). After multivariate logistic regression analysis, independent risk factors for BSICs included initial inappropriate antibiotics (odds ratio [OR], 5.54; 95% confidence interval [CI], 3.40–9.01), BSI with septic shock (OR, 5.75; 95% CI, 3.51–9.40), and BSI concurrent with meningitis (OR, 9.20; 95% CI, 4.33–19.56). It is worth noting that a percentage of neonates with BSI encountered subsequent sequelae or died of infections complications, which were significantly associated with initial inappropriate antibiotic therapy, septic shock, and the occurrence of meningitis. Further investigation is

  12. A simple method to purify biologically and antigenically preserved bloodstream trypomastigotes of Trypanosoma cruzi using Deae-cellulose columns

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    Maria Auxiliadora de Sousa

    1983-09-01

    Full Text Available A method to purify trypanosomastigotes of some strains of Trypanosoma cruzi (Y, CL, FL, F, "Berenice", "Colombiana" and "São Felipe" from mouse blood by using DEAE-cellulose columns was standardized. This procedure is a modification of the Lanham & Godfrey methods and differs in some aspects from others described to purify T. cruzi bloodstream trypomastigotes, mainly by avoidance of prior purifications of parasites. By this method, the broad trypomastigotes were mainly isolated, accounting for higher recoveries obtained with strains having higher percentages of these forms: processing of infected blood from irradiated mice could be advantageous by increasing the recovery of parasites (percentage and/or total number and elution of more slender trypomastigotes. Trypomastigotes purified by this method presented normal morphology and motility, remained infective to triatomine bugs and mice, showing in the latter prepatent periods and courses parasitemia similar to those of control parasites, and also reproducing the polymorphism pattern of each strain. Their virulence and pathogenicity also remained considerably preserved, the latter property being evaluated by LD 50 tests, mortality rates and mean survival time of inoculated mice. Moreover, these parasites presented positive, clear and peripheral immunofluorescence reaction at titres similar to those of control organisms, thus suggesting important preservation of their surface antigens.Usando colunas de DEAE-cellulose foi padronizado um método para purificação de tripomastigotas de várias cepas de Trypanosoma cruzi (Y, CL, FL, F, "Berenice", "Columbiana" e "São Felipe" a partir do sangue de camundongos. Este método é uma modificação daqueles descritos por Lanham & Godfrey e difere em vários aspectos de outros descritos para purificar as formas sanguíneas deste parasita, particularmente na dispensa de pré-purificações. Por ele foram isolados principalmente os tripomastigotas largos

  13. Antibiotic pressure mediated selection of non-biofilm forming strain of Elizabethkingia meningosepticum causing fatal nosocomial meningitis in a term infant

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    Sumit Rai

    2013-01-01

    Full Text Available We describe a fatal case of hospital acquired meningitis in a term infant due to the antibiotic pressure mediated selection of Elizabethkingia meningosepticum. The antibiotics were administered for multi-drug resistant Acinetobacter baumannii infection. The strain was also phenotypically characterized for beta lactamase production, biofilm forming capability and resistance to in use disinfectants.

  14. Strain hardening behaviour in forming of sintered iron-0.35% carbon powder metallurgy preform during cold upsetting

    OpenAIRE

    Sumesh Narayan; Ananthanarayanan Rajeshkannan

    2011-01-01

    A complete experimental investigation on the instantaneous strain-hardening behaviour of powder metallurgy preforms of Fe-0.35%C was carried out. The strain hardening behaviour of the above-mentioned P/M sintered steel preforms with aspect ratio of 0.4 and 0.6, respectively, under triaxial stress state condition was determined by cold upsetting under nil/no and graphite lubricant conditions. The instantaneous strain hardening value (n i), strength coefficient (Ki), and the stress as a functio...

  15. The changing epidemiology of group B streptococcus bloodstream infection

    DEFF Research Database (Denmark)

    Ballard, Mark S; Schønheyder, Henrik C; Lyytikäinen, Outi;

    2016-01-01

    Background Population-based studies conducted in single regions or countries have identified significant changes in the epidemiology of invasive group B streptococcus (GBS) infection. However, no studies have concurrently compared the epidemiology of GBS infections among multiple different region...... these regions, it was consistently found that rates increased among older adults, especially in association with diabetes. The burden of this infection may be expected to continue to increase in ageing populations worldwide....... and countries over time. The study objectives were to define the contemporary incidence and determinants of GBS bloodstream infection (BSI) and assess temporal changes in a multi-national population. Methods Population-based surveillance for GBS BSI was conducted in nine regions in Australia, Canada, Denmark...... differences in the overall (range = 1.8-4.1 per 100 000 person-year) and neonatal (range = 0.19-0.83 per 1000 live births) incidences of GBS BSI observed among the study regions. The overall incidence significantly (p = 0.05) increased. Rates of neonatal disease were stable, while the incidence in individuals...

  16. The changing epidemiology of Staphylococcus aureus bloodstream infection

    DEFF Research Database (Denmark)

    Galbraith, J.C.; Valiquette, G.; Kennedy, K.J.;

    2013-01-01

    Clin Microbiol Infect ABSTRACT: Although the epidemiology of Staphylococcus aureus bloodstream infection (BSI) has been changing, international comparisons are lacking. We sought to determine the incidence of S. aureus BSI and assess trends over time and by region. Population-based surveillance...... episodes of S. aureus BSI were identified. The overall annual incidence rate for S. aureus BSI was 26.1 per 100 000 population, and those for methicillin-sensitive S. aureus (MSSA) and methicillin-resistant S. aureus (MRSA) were 24.2 and 1.9 per 100 000, respectively. Although the overall incidence...... of community-onset MSSA BSI (15.0 per 100 000) was relatively similar across regions, the incidence rates of hospital-onset MSSA (9.2 per 100 000), community-onset MRSA (1.0 per 100 000) and hospital-onset MRSA (0.8 per 100 000) BSI varied substantially. Whereas the overall incidence of S. aureus BSI did...

  17. Elasto-visco-plastic modeling of mild steels for sheet forming applications over a large range of strain rates

    OpenAIRE

    PIPARD, Jean-Marc; BALAN, Tudor; ABED-MERAIM, Farid; LEMOINE, Xavier

    2013-01-01

    A physically based elasto-visco-plastic constitutive model is presented and compared to experimental results for three different mild steels. The experiments consist of tensile tests ranging from quasi-static conditions up to strain rates of 103 s-1 as well as quasi-static simple and reverse shear tests at different amounts of pre-strain. Additional two-step sequential mechanical tests (Bauschinger and orthogonal effects) have been performed to further evaluate the ability of the model to des...

  18. Biofilm formation is a risk factor for mortality in patients with Candida albicans bloodstream infection – Scotland, 2012-2013

    OpenAIRE

    Rajendran, Ranjith; Sherry, Leighann; Nile, Christopher; Sherriff, Andrea; Johnson, Elizabeth; Hanson, Mary; Williams, Craig; Munro, Carol; Jones, Brian; Ramage, Gordon

    2016-01-01

    Bloodstream infections caused by Candida species remain a significant cause of morbidity and mortality in hospitalized patients. Biofilm formation by Candida species is an important virulence factor for disease pathogenesis. A prospective analysis of patients with Candida bloodstream infection (n = 217) in Scotland (2012–2013) was performed to assess the risk factors associated with patient mortality, in particular the impact of biofilm formation. Candida bloodstream isolates (n = 280) and cl...

  19. In vitro antifungal susceptibility of Malassezia furfur from bloodstream infections.

    Science.gov (United States)

    Iatta, Roberta; Figueredo, Luciana A; Montagna, Maria Teresa; Otranto, Domenico; Cafarchia, Claudia

    2014-11-01

    Fungaemia caused by Malassezia spp. in hospitalized patients requires prompt and appropriate therapy, but standard methods for the definition of the in vitro antifungal susceptibility have not been established yet. In this study, the in vitro susceptibility of Malassezia furfur from bloodstream infections (BSIs) to amphotericin B (AMB), fluconazole (FLC), itraconazole (ITC), posaconazole (POS) and voriconazole (VRC) was assessed using the broth microdilution (BMD) method of the Clinical and Laboratory Standards Institute (CLSI) with different media such as modified Sabouraud dextrose broth (SDB), RPMI and Christensen's urea broth (CUB). Optimal broth media that allow sufficient growth of M. furfur, and produce reliable and reproducible MICs using the CLSI BMD protocol were assessed. Thirty-six M. furfur isolates collected from BSIs of patients before and during AMB therapy, and receiving FLC prophylaxis, were tested. A good growth of M. furfur was observed in RPMI, CUB and SDB at 32 °C for 48 and 72 h. No statistically significant differences were detected between the MIC values registered after 48 and 72 h incubation. ITC, POS and VRC displayed lower MICs than FLC and AMB. These last two antifungal drugs showed higher and lower MICs, respectively, when the isolates were tested in SDB. SDB is the only medium in which it is possible to detect isolates with high FLC MICs in patients receiving FLC prophylaxis. A large number of isolates showed high AMB MIC values regardless of the media used. In conclusion, SDB might be suitable to determine triazole susceptibility. However, the media, the drug formulation or the breakpoints herein applied might not be useful for assessing the AMB susceptibility of M. furfur from BSIs. PMID:25168965

  20. Keratinolytic activity exhibited in an indigenous non-dermatophytic fungus strain cochliobolus lunatus isolated form khairpur sindh pakistan

    International Nuclear Information System (INIS)

    Keratins are the widely distributed fibrous proteins of our environment. Keratinase are proteolytic enzymes responsible for hydrolyzing insoluble keratin largely produced by microorganisms including fungi. We report the isolation, identification and characterization of a non-dermatophytic keratinolytic fungal strain of C. lunatus from the soils of Khairpur Sindh Pakistan. The temperature optimum for this strain for production of the enzyme was 30 degree C. preferable carbon and nitrogen sources were glucose and gelatin respectively; optimum time for keratinase production was 9 days and the activity suppressed by Ca suggesting it a metalloprotease. (author)

  1. Genome Sequence of the Red Pigment-Forming Meiothermus taiwanensis Strain RP Isolated from Paniphala Hot Spring, India

    Science.gov (United States)

    Mukherjee, Trinetra; Bose, Sucharita; Sen, Urmimala; Roy, Chayan; Rameez, Moidu Jameela; Ghosh, Wriddhiman

    2016-01-01

    Here we report the draft genome sequence of Meiothermus taiwanensis strain RP (MCC 2966), isolated from the Paniphala hot spring of India, which contains genes encoding for enzymes of the methyl erythritol 4-phosphate (MEP) pathway of isoprenoid biosynthesis and carotenoid backbone synthesis. PMID:27365353

  2. Inhibition of certain strains of HIV-1 by cell surface polyanions in the form of cholesterol-labeled oligonucleotides

    International Nuclear Information System (INIS)

    Cholesterol-labeled oligonucleotides were found several years ago to inhibit HIV-1 in tissue culture at nanomolar concentrations. We present evidence that this is mainly due to an electrostatic interaction between polyanionic oligonucleotide concentrated at the cell surface and a positively charged region in the V3 loop of the HIV-1 envelope protein. When added to tissue culture, cholesterol-labeled oligonucleotides became concentrated at the plasma membrane and potently inhibited virus entry and cell fusion mediated by the envelope protein of some X4 strains of HIV-1, but had little effect on fusion mediated by R5 strains of HIV-1, amphotropic MLV envelope protein, or VSV-G protein. Noncholesterol-labeled oligonucleotides did not bind to the cell surface or inhibit fusion. The pattern of susceptibility to cholesterol-labeled oligonucleotides among HIV-1 strains was the same as reported for nonmembrane-associating polyanions such as dextran sulfate, but the cholesterol-labeled oligonucleotides were effective at lower concentrations. Substitution of a basic 33 amino acid V3 loop sequence from the envelope protein of a resistant strain into a susceptible strain made the envelope protein resistant to inhibition. Inhibition by cholesterol-labeled oligonucleotides was abrogated by the polycation DEAE-dextran. Cholesterol-labeled oligonucleotides bound to nonraft regions of the plasma membrane and did not inhibit HIV virus binding to cells. Many infectious agents first associate with target cells via relatively nonspecific charge interactions; our data suggest that molecules that combine a membrane-targeting motif with multiple negative charges might be useful to modify these interactions

  3. Metabolic labeling with (14C)-glucose of bloodstream and cell culture trypanosoma cruzi trypomastigotes:

    International Nuclear Information System (INIS)

    Trypomastigote forms of Trypanosoma cruzi from infected mouse blood and from cell culture were metabolically labeled by incubation with D-(14C)-glucose. Analysis by polyacrylamide gel electrophoresis of lysates from parasites of two strains (RA and CA1) showed a significantly different pattern. The difference was mainly quantitative when the blood and cell culture trypomastigotes of the RA strain were compared. Analysis of the culture medium by paper electrophoresis showed an anionic exometabolite only in the blood forms of both strains. (Author)

  4. Application of the continuum shell finite element SHB8PS to sheet forming simulation using an extended large strain anisotropic elastic-plastic formulation

    OpenAIRE

    SALAHOUELHADJ, Abdellah; ABED-MERAIM, Farid; Chalal, Hocine; BALAN, Tudor

    2012-01-01

    http://link.springer.com/article/10.1007%2Fs00419-012-0620-x International audience This paper proposes an extension of the SHB8PS solid-shell finite element to large strain anisotropic elasto-plasticity, with application to several non-linear benchmark tests including sheet metal forming simulations. This hexahedral linear element has an arbitrary number of integration points distributed along a single line, defining the "thickness" direction; and to control the hourglass modes inheren...

  5. Draft Genome Assembly of the Bloom-Forming Cyanobacterium Nodularia spumigena Strain CENA596 in Shrimp Production Ponds.

    Science.gov (United States)

    Popin, Rafael Vicentini; Rigonato, Janaina; Abreu, Vinicius Augusto Carvalho; Andreote, Ana Paula Dini; Silveira, Savênia Bonoto; Odebrecht, Clarisse; Fiore, Marli Fatima

    2016-01-01

    We report here the draft genome assembly of the brackish cyanobacterium Nodularia spumigena strain CENA596 isolated from a shrimp production pond in Rio Grande do Sul, Brazil. The draft genome consists of 291 contigs with a total size of 5,189,679 bp. Secondary metabolite annotations resulted in several predicted gene clusters, including those responsible for encoding the hepatotoxin nodularin. PMID:27284148

  6. Enterobacteriaceae Bloodstream Infections: Presence of Integrons, Risk Factors, and Outcome▿

    Science.gov (United States)

    Daikos, George L.; Kosmidis, Chris; Tassios, Panayotis T.; Petrikkos, George; Vasilakopoulou, Alexandra; Psychogiou, Mina; Stefanou, Ioanna; Avlami, Athina; Katsilambros, Nikolaos

    2007-01-01

    A prospective observational study was conducted to identify factors associated with bloodstream infections (BSIs) caused by integron-carrying Enterobacteriaceae and to evaluate the clinical significance of integron carriage. Consecutive patients with Enterobacteriaceae BSIs were identified and followed up until discharge or death. Identification of blood isolates and susceptibility testing were performed by the Wider I automated system. int-1-specific PCR, conserved-segment PCR, and DNA sequencing were used to determine the presence, length, and content of integrons. The relatedness among the isolates was examined by pulsed-field gel electrophoresis. Two hundred fifty episodes of Enterobacteriaceae BSI occurred in 233 patients; 109 (43.6%) were nosocomial, 82 (32.8%) were community acquired, and 59 (23.6%) were health care associated. Integrons were detected in 11 (13.4%) community-acquired, 24 (40.7%) health care-associated, and 46 (42.2%) nosocomial isolates. Integron-carrying organisms were more likely to exhibit resistance to three or more classes of antimicrobials (odds ratio [OR], 9.84; 95% confidence interval [95% CI], 5.31 to 18.23; P < 0.001) or to produce extended-spectrum β-lactamases (OR, 5.75; 95% CI, 2.38 to 13.89; P < 0.001) or a VIM-type metallo-β-lactamase (P, 0.003). Inter- or intraspecies integron transfer and cross-transmission of integron-carrying clones were observed. Use of cotrimoxazole (OR, 4.77; 95% CI, 1.81 to 12.54; P < 0.001) and a nosocomial or other health care setting (OR, 3.07; 95% CI, 1.30 to 7.22; P, 0.01) were independently associated with BSIs caused by integron-carrying Enterobacteriaceae. Patients with a nonurinary source of bacteremia (OR, 9.46; 95% CI, 2.77 to 32.32; P < 0.001) and a Pitt bacteremia score of ≥4 (OR, 23.36; 95% CI, 7.97 to 68.44; P < 0.001) had a significantly higher 14-day mortality rate, whereas integron carriage did not affect clinical outcomes. These findings may have implications affecting antibiotic

  7. Enzymes produced by halotolerant spore-forming gram-positive bacterial strains isolated from a resting habitat (Restinga de Jurubatiba) in Rio de Janeiro, Brazil: focus on proteases.

    Science.gov (United States)

    D Santos, Anderson Fragoso; Pacheco, Clarissa Almeida; Valle, Roberta D Santos; Seldin, Lucy; D Santos, André Luis Souza

    2014-12-01

    The screening for hydrolases-producing, halotolerant, and spore-forming gram-positive bacteria from the root, rhizosphere, and non-rhizosphere soil of Blutaparon portulacoides, a plant found in the Restinga de Jurubatiba located at the northern region of Rio de Janeiro State, Brazil, resulted in the isolation of 22 strains. These strains were identified as Halobacillus blutaparonensis (n = 2), Oceanobacillus picturae (n = 5), and Oceanobacillus iheyensis (n = 15), and all showed the ability to produce different extracellular enzymes. A total of 20 isolates (90.9 %) showed activity for protease, 5 (22.7 %) for phytase, 3 (13.6 %) for cellulase, and 2 (9.1 %) for amylase. Some bacterial strains were capable of producing three (13.6 %) or two (9.1 %) distinct hydrolytic enzymes. However, no bacterial strain with ability to produce esterase and DNase was observed. The isolate designated M9, belonging to the species H. blutaparonensis, was the best producer of protease and also yielded amylase and phytase. This strain was chosen for further studies regarding its protease activity. The M9 strain produced similar amounts of protease when grown either without or with different NaCl concentrations (from 0.5 to 10 %). A simple inspection of the cell-free culture supernatant by gelatin-sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) revealed the presence of three major alkaline proteases of 40, 50, and 70 kDa, which were fully inhibited by phenylmethylsulfonyl fluoride (PMSF) and tosyl-L-phenylalanine chloromethyl ketone (TPCK) (two classical serine protease inhibitors). The secreted proteases were detected in a wide range of temperature (from 4 to 45 °C) and their hydrolytic activities were stimulated by NaCl (up to 10 %). The serine proteases produced by the M9 strain cleaved gelatin, casein, albumin, and hemoglobin, however, in different extensions. Collectively, these results suggest the potential use of the M9 strain in biotechnological

  8. Purification and Characterization of a Maltotetraose-Forming Alkaline (alpha)-Amylase from an Alkalophilic Bacillus Strain, GM8901

    OpenAIRE

    Kim, T U; Gu, B. G.; Jeong, J Y; Byun, S. M.; Shin, Y. C.

    1995-01-01

    An alkalophilic bacterium, Bacillus sp. strain GM8901, grown at pH 10.5 and 50(deg)C, produced five alkaline amylases in culture broth. At an early stage of the bacterial growth, amylase I (Amyl I) was produced initially and then, as cultivation progressed, four alkaline amylases, Amyl II, Amyl III, Amyl IV, and Amyl V, were produced from proteolytic degradation of Amyl I. A serine protease present in the culture medium was believed to be involved in Amyl I degradation. We purified Amyl I fro...

  9. The Phosphoproteome of Bloodstream Form Trypanosoma brucei, Causative Agent of African Sleeping Sickness

    OpenAIRE

    Nett, Isabelle R. E.; Martin, David M. A.; Miranda-Saavedra, Diego; Lamont, Douglas; Barber, Jonathan D.; Mehlert, Angela; Ferguson, Michael A. J.

    2009-01-01

    The protozoan parasite Trypanosoma brucei is the causative agent of human African sleeping sickness and related animal diseases, and it has over 170 predicted protein kinases. Protein phosphorylation is a key regulatory mechanism for cellular function that, thus far, has been studied in T.brucei principally through putative kinase mRNA knockdown and observation of the resulting phenotype. However, despite the relatively large kinome of this organism and the demonstrated essentiality of severa...

  10. Ribose 5-Phosphate Isomerase B Knockdown Compromises Trypanosoma brucei Bloodstream Form Infectivity

    OpenAIRE

    Inês Loureiro; Joana Faria; Christine Clayton; Sandra Macedo-Ribeiro; Nuno Santarém; Nilanjan Roy; Anabela Cordeiro-da-Siva; Joana Tavares

    2015-01-01

    Ribose 5-phosphate isomerase is an enzyme involved in the non-oxidative branch of the pentose phosphate pathway, and catalyzes the inter-conversion of D-ribose 5-phosphate and D-ribulose 5-phosphate. Trypanosomatids, including the agent of African sleeping sickness namely Trypanosoma brucei, have a type B ribose-5-phosphate isomerase. This enzyme is absent from humans, which have a structurally unrelated ribose 5-phosphate isomerase type A, and therefore has been proposed as an attractive dru...

  11. A Gateway® compatible vector for gene silencing in bloodstream form Trypanosoma brucei

    OpenAIRE

    Kalidas, Savitha; Li, Qiong; Margaret A Phillips

    2011-01-01

    RNA interference is the most rapid method for generation of conditional knockdown mutants in Trypanosoma brucei. The dual T7 promoter (pZJM) and the stem-loop vectors have been widely used to generate stable inducible RNAi cell lines with the latter providing tighter regulatory control. However, the steps for cloning stem-loop constructs are cumbersome requiring either multiple cloning steps or multi-fragment ligation reactions. We report the development of a vector (pTrypRNAiGate) derived fr...

  12. Alkaloids Induce Programmed Cell Death in Bloodstream Forms of Trypanosomes (Trypanosoma b. brucei

    Directory of Open Access Journals (Sweden)

    Michael Wink

    2008-10-01

    Full Text Available The potential induction of a programmed cell death (PCD in Trypanosoma b. brucei by 55 alkaloids of the quinoline, quinolizidine, isoquinoline, indole, terpene, tropane, steroid, and piperidine type was studied by measuring DNA fragmentation and changes in mitochondrial membrane potential. For comparison, the induction of apoptosis by the same alkaloids in human leukemia cells (Jurkat APO-S was tested. Several alkaloids of the isoquinoline, quinoline, indole and steroidal type (berberine, chelerythrine, emetine, sanguinarine, quinine, ajmalicine, ergotamine, harmine, vinblastine, vincristine, colchicine, chaconine, demissidine and veratridine induced programmed cell death, whereas quinolizidine, tropane, terpene and piperidine alkaloids were mostly inactive. Effective PCD induction (EC50 below 10 µM was caused in T. brucei by chelerythrine, emetine, sanguinarine, and chaconine. The active alkaloids can be characterized by their general property to inhibit protein biosynthesis, to intercalate DNA, to disturb membrane fluidity or to inhibit microtubule formation.

  13. Alkaloids Induce Programmed Cell Death in Bloodstream Forms of Trypanosomes (Trypanosoma b. brucei)

    OpenAIRE

    Michael Wink; Vera Rosenkranz

    2008-01-01

    The potential induction of a programmed cell death (PCD) in Trypanosoma b. brucei by 55 alkaloids of the quinoline, quinolizidine, isoquinoline, indole, terpene, tropane, steroid, and piperidine type was studied by measuring DNA fragmentation and changes in mitochondrial membrane potential. For comparison, the induction of apoptosis by the same alkaloids in human leukemia cells (Jurkat APO-S) was tested. Several alkaloids of the isoquinoline, quinoline, indole and steroidal type (berberine, c...

  14. Secular Trends in Nosocomial Bloodstream Infections : Antibiotic-Resistant Bacteria Increase the Total Burden of Infection

    NARCIS (Netherlands)

    Ammerlaan, H. S. M.; Harbarth, S.; Buiting, A. G. M.; Crook, D. W.; Fitzpatrick, F.; Hanberger, H.; Herwaldt, L. A.; van Keulen, P. H. J.; Kluytmans, J. A. J. W.; Kola, A.; Kuchenbecker, R. S.; Lingaas, E.; Meessen, N.; Morris-Downes, M. M.; Pottinger, J. M.; Rohner, P.; dos Santos, R. P.; Seifert, H.; Wisplinghoff, H.; Ziesing, S.; Walker, A. S.; Bonten, M. J. M.

    2013-01-01

    Background. It is unknown whether rising incidence rates of nosocomial bloodstream infections (BSIs) caused by antibiotic-resistant bacteria (ARB) replace antibiotic-susceptible bacteria (ASB), leaving the total BSI rate unaffected. Methods. We investigated temporal trends in annual incidence densit

  15. First Report of Treatment of Anaerobiospirillum succiniciproducens Bloodstream Infection with Levofloxacin ▿

    OpenAIRE

    Kelesidis, Theodoros; Bard, Jennifer Dien; Humphries, Romney; Ward, Kevin; Lewinski, Michael A.; Uslan, Daniel Z.

    2010-01-01

    The full extent of the clinical spectrum and optimal therapy of Anaerobiospirillum succiniciproducens infections remains to be determined. We describe the first case of bloodstream infection (BSI) due to A. succiniciproducens in an asymptomatic elderly male with poor dentition that was treated with levofloxacin.

  16. A case of catheter-related bloodstream infection caused by Mycobacterium phocaicum.

    Science.gov (United States)

    Simkins, Jacques; Rosenblatt, Joseph D

    2013-05-01

    We present a patient with double hit Burkitt's like lymphoma who developed a catheter-related bloodstream infection due to Mycobacterium phocaicum that was identified by rpoB gene sequencing. His infection resolved with 7 weeks of antibiotics and port-a-cath removal. PMID:23537787

  17. Bloodstream Infections in Very Low Birth Weight Infants with Intestinal Failure

    NARCIS (Netherlands)

    Cole, Conrad R.; Hansen, Nellie I.; Higgins, Rosemary D.; Bell, Edward F.; Shankaran, Seetha; Laptook, Abbot R.; Walsh, Michele C.; Hale, Ellen C.; Newman, Nancy S.; Das, Abhik; Stoll, Barbara J.

    2012-01-01

    Objective To examine pathogens and other characteristics associated with late-onset bloodstream infections (BSIs) in infants with intestinal failure (IF) as a consequence of necrotizing enterocolitis (NEC). Study design Infants weighing 401-1500 g at birth who survived for >72 hours and received car

  18. Reducing Central Line-Associated Bloodstream Infections 
on Inpatient Oncology Units Using Peer Review.

    Science.gov (United States)

    Zavotsky, Kathleen Evanovich; Malast, Tracey; Festus, Onyekachi; Riskie, Vickie

    2015-12-01

    The purpose of this article is to describe a peer-to-peer program and the outcomes of interventions to reduce the incidence of central line-associated bloodstream infections in patients in bone marrow transplantation, medical, and surgical oncology units. The article reviews the process and describes tools used to achieve success in a Magnet®-designated academic medical center. PMID:26583628

  19. Routine Surveillance for Bloodstream Infections in a Pediatric Hematopoietic Stem Cell Transplant Cohort: Do Patients Benefit?

    Directory of Open Access Journals (Sweden)

    Heather Rigby

    2007-01-01

    Full Text Available BACKGROUND: Hematopoietic stem cell transplant (HSCT recipients are at a high risk for late bloodstream infection (BSI. Controversy exists regarding the benefit of surveillance blood cultures in this immunosuppressed population. Despite the common use of this practice, the practical value is not well established in non-neutropenic children following HSCT.

  20. Association between prehospital vitamin D status and hospital-acquired bloodstream infections123

    OpenAIRE

    Quraishi, Sadeq A.; Litonjua, Augusto A.; Moromizato, Takuhiro; Gibbons, Fiona K; Camargo, Carlos A; Giovannucci, Edward; Christopher, Kenneth B.

    2013-01-01

    Background: Alterations in immune function can predispose patients to nosocomial infections. Few studies have explored potentially modifiable host factors that may improve immune function and decrease risk of hospital-acquired bloodstream infection (HABSI). Vitamin D is a key regulator of innate and adaptive immune systems that may influence host susceptibility to infections.

  1. Patients with Central Lines - What You Need to Know to Avoid a Bloodstream Infection PSA (:60)

    Centers for Disease Control (CDC) Podcasts

    2011-03-01

    This 60 second PSA is based on the March, 2011 CDC Vital Signs report which indicates bloodstream infections in patients with central lines are largely preventable when healthcare providers use CDC-recommended infection control steps.  Created: 3/1/2011 by Centers for Disease Control and Prevention (CDC).   Date Released: 3/1/2011.

  2. 3′,5′-Cyclic Diguanylic Acid Reduces the Virulence of Biofilm-Forming Staphylococcus aureus Strains in a Mouse Model of Mastitis Infection

    OpenAIRE

    Brouillette, Eric; Hyodo, Mamoru; Hayakawa, Yoshihiro; Karaolis, David K.R.; Malouin, François

    2005-01-01

    The cyclic dinucleotide 3′,5′-cyclic diguanylic acid (c-di-GMP) is a naturally occurring small molecule that regulates important signaling systems in bacteria. We have recently shown that c-di-GMP inhibits Staphylococcus aureus biofilm formation in vitro and its adherence to HeLa cells. We now report that c-di-GMP treatment has an antimicrobial and antipathogenic activity in vivo and reduces, in a dose-dependent manner, bacterial colonization by biofilm-forming S. aureus strains in a mouse mo...

  3. Genes involved in degradation of para-nitrophenol are differentially arranged in form of non-contiguous gene clusters in Burkholderia sp. strain SJ98.

    Directory of Open Access Journals (Sweden)

    Surendra Vikram

    Full Text Available Biodegradation of para-Nitrophenol (PNP proceeds via two distinct pathways, having 1,2,3-benzenetriol (BT and hydroquinone (HQ as their respective terminal aromatic intermediates. Genes involved in these pathways have already been studied in different PNP degrading bacteria. Burkholderia sp. strain SJ98 degrades PNP via both the pathways. Earlier, we have sequenced and analyzed a ~41 kb fragment from the genomic library of strain SJ98. This DNA fragment was found to harbor all the lower pathway genes; however, genes responsible for the initial transformation of PNP could not be identified within this fragment. Now, we have sequenced and annotated the whole genome of strain SJ98 and found two ORFs (viz., pnpA and pnpB showing maximum identity at amino acid level with p-nitrophenol 4-monooxygenase (PnpM and p-benzoquinone reductase (BqR. Unlike the other PNP gene clusters reported earlier in different bacteria, these two ORFs in SJ98 genome are physically separated from the other genes of PNP degradation pathway. In order to ascertain the identity of ORFs pnpA and pnpB, we have performed in-vitro assays using recombinant proteins heterologously expressed and purified to homogeneity. Purified PnpA was found to be a functional PnpM and transformed PNP into benzoquinone (BQ, while PnpB was found to be a functional BqR which catalyzed the transformation of BQ into hydroquinone (HQ. Noticeably, PnpM from strain SJ98 could also transform a number of PNP analogues. Based on the above observations, we propose that the genes for PNP degradation in strain SJ98 are arranged differentially in form of non-contiguous gene clusters. This is the first report for such arrangement for gene clusters involved in PNP degradation. Therefore, we propose that PNP degradation in strain SJ98 could be an important model system for further studies on differential evolution of PNP degradation functions.

  4. Use of a temperature-sensitive, protoplast-forming Neurospora crassa strain for the detection of antifungal antibiotics.

    OpenAIRE

    Selitrennikoff, C P

    1983-01-01

    Protoplasts of the temperature-sensitive osmotic-1 mutant of Neurospora crassa grew and divided as cell wall-less cells when incubated under certain conditions at 37 degrees C. Each protoplast regenerated cell wall and formed a mycelium when the temperature was shifted to 22 degrees C. Cell wall regeneration, but not cell growth, was prevented by the inhibition of cell wall assembly functions. Thus, the inhibition of cell wall regeneration could serve as an indicator of the mode of action of ...

  5. High MICs for Vancomycin and Daptomycin and Complicated Catheter-Related Bloodstream Infections with Methicillin-Sensitive Staphylococcus aureus

    Science.gov (United States)

    Viedma, Esther; Chaves, Fernando; Lalueza, Antonio; Fortún, Jesús; Loza, Elena; Pujol, Miquel; Ardanuy, Carmen; Morales, Isabel; de Cueto, Marina; Resino-Foz, Elena; Morales-Cartagena, Alejandra; Rico, Alicia; Romero, María P.; Orellana, María Ángeles; López-Medrano, Francisco; Fernández-Ruiz, Mario; Aguado, José María

    2016-01-01

    We investigated the prognostic role of high MICs for antistaphylococcal agents in patients with methicillin-sensitive Staphylococcus aureus catheter-related bloodstream infection (MSSA CRBSI). We prospectively reviewed 83 episodes from 5 centers in Spain during April 2011–June 2014 that had optimized clinical management and analyzed the relationship between E-test MICs for vancomycin, daptomycin, oxacillin, and linezolid and development of complicated bacteremia by using multivariate analysis. Complicated MSSA CRBSI occurred in 26 (31.3%) patients; MICs for vancomycin and daptomycin were higher in these patients (optimal cutoff values for predictive accuracy = 1.5 μg/mL and 0.5 μg/mL). High MICs for vancomycin (hazard ratio 2.4, 95% CI 1.2–5.5) and daptomycin (hazard ratio 2.4, 95% CI 1.1–5.9) were independent risk factors for development of complicated MSSA CRBSI. Our data suggest that patients with MSSA CRBSI caused by strains that have high MICs for vancomycin or daptomycin are at increased risk for complications. PMID:27192097

  6. High MICs for Vancomycin and Daptomycin and Complicated Catheter-Related Bloodstream Infections with Methicillin-Sensitive Staphylococcus aureus.

    Science.gov (United States)

    San-Juan, Rafael; Viedma, Esther; Chaves, Fernando; Lalueza, Antonio; Fortún, Jesús; Loza, Elena; Pujol, Miquel; Ardanuy, Carmen; Morales, Isabel; de Cueto, Marina; Resino-Foz, Elena; Morales-Cartagena, Alejandra; Rico, Alicia; Romero, María P; Orellana, María Ángeles; López-Medrano, Francisco; Fernández-Ruiz, Mario; Aguado, José María

    2016-06-01

    We investigated the prognostic role of high MICs for antistaphylococcal agents in patients with methicillin-sensitive Staphylococcus aureus catheter-related bloodstream infection (MSSA CRBSI). We prospectively reviewed 83 episodes from 5 centers in Spain during April 2011-June 2014 that had optimized clinical management and analyzed the relationship between E-test MICs for vancomycin, daptomycin, oxacillin, and linezolid and development of complicated bacteremia by using multivariate analysis. Complicated MSSA CRBSI occurred in 26 (31.3%) patients; MICs for vancomycin and daptomycin were higher in these patients (optimal cutoff values for predictive accuracy = 1.5 μg/mL and 0.5 μg/mL). High MICs for vancomycin (hazard ratio 2.4, 95% CI 1.2-5.5) and daptomycin (hazard ratio 2.4, 95% CI 1.1-5.9) were independent risk factors for development of complicated MSSA CRBSI. Our data suggest that patients with MSSA CRBSI caused by strains that have high MICs for vancomycin or daptomycin are at increased risk for complications. PMID:27192097

  7. Trypanosoma cruzi: strain selection by diferent schedules of mouse passage of an initially mixed infection

    Directory of Open Access Journals (Sweden)

    Maria P. Deane

    1984-12-01

    Full Text Available From an initial double infection in mice, established by simultaneous and equivalent inocula of bloodstream forms of strains Y and F of Trypanosoma cruzi, two lines were derived by subinoculations: one (W passaged every week, the other (M every month. Through biological and biochemical methods only the Y strain was identified at the end of the 10th and 16th passages of line W and only the F strain at the 2nd and 4th passages of line M. The results illustrate strain selection through laboratory manipulation of initially mixed populations of T. cruzi.De uma infecção inicialmente dupla em camundongo, estabelecida por inóculo simultaneo e equivalente de formas sanguíneas das cepas Y e F de Trypanosoma cruzi, duas linhagens foram originadas por subinoculações: uma (W passada casa semana, a outra (M cada mês. Por métodos biológicos e bioquímicos apenas a cepa Y foi identificada ao fim a 10a. e 16a. passagens da linhagem W e apenas a cepa F na 2a. e 4a.passagens de linhagem M. Os resultados demonstram a seleção de cepas através de manipulação em laboratorio de populações inicialmente mistas de T. cruzi.

  8. Cluster of Candida parapsilosis primary bloodstream infection in a neonatal intensive care unit

    Directory of Open Access Journals (Sweden)

    Silva Carmem Lúcia P. da

    2001-01-01

    Full Text Available Candida parapsilosis is an increasingly important bloodstream pathogen in neonatal intensive care units (NICU. We investigated a cluster of bloodstream infections in a NICU to determine whether nosocomial transmission occurred. During a 3-day period, 3 premature infants hospitalized in the same unit presented with sepsis caused by C. parapsilosis. Electrophoretic karyotype of the organisms was performed by using pulsed field gel electrophoresis in a countour-clamped homogeneous electric field system. The isolate from 1 newborn could not be typed, and the isolates from the remaining 2 infants had identical patterns. All 3 cases are described. We conclude that nosocomial transmission of C. parapsilosis occurred and that neonates under intensive care may represent a risk group for this pathogen.

  9. Current strategies for the prevention and management of central line-associated bloodstream infections

    Directory of Open Access Journals (Sweden)

    Zhuolin Han

    2010-11-01

    Full Text Available Zhuolin Han, Stephen Y Liang, Jonas MarschallDivision of Infectious Diseases, Washington University School of Medicine in St Louis, St Louis, MO, USAAbstract: Central venous catheters are an invaluable tool for diagnostic and therapeutic purposes in today’s medicine, but their use can be complicated by bloodstream infections (BSIs. While evidence-based preventive measures are disseminated by infection control associations, the optimal management of established central line-associated BSIs has been summarized in infectious diseases guidelines. We prepared an overview of the state-of-the-art of prevention and management of central line-associated BSIs and included topics such as the role of antibiotic-coated catheters, the role of catheter removal in the management, and a review of currently used antibiotic compounds and the duration of treatment.Keywords: central venous catheters, bloodstream infections, guidelines, prevention

  10. The Impact of Infectious Disease Specialist Consultation for Staphylococcus aureus Bloodstream Infections: A Systematic Review.

    Science.gov (United States)

    Paulsen, Julie; Solligård, Erik; Damås, Jan Kristian; DeWan, Andrew; Åsvold, Bjørn Olav; Bracken, Michael B

    2016-03-01

    Staphylococcus aureus is a common cause of severe bloodstream infection. We performed a systematic review to assess whether consultation with infectious disease specialists decreased all-cause mortality or rate of complications of S aureus bloodstream infections. The review also assessed parameters associated with the quality of management of the infection. We searched for eligible studies in PubMed, Embase, Scopus, and clinical trials.gov as well as the references of included studies. We identified 22 observational studies and 1 study protocol for a randomized trial. A meta-analysis was not performed because of the high risk of bias in the included studies. The outcomes are reported in a narrative review. Most included studies reported survival benefit, in the adjusted analysis. Recommended management strategies were carried out significantly more often among patients seen by an infectious disease specialist. Trials, such as cluster-randomized controlled trials, can more validly assess the studies at low risk of bias. PMID:27047985

  11. Catheter related bloodstream infection%导管相关血流感染

    Institute of Scientific and Technical Information of China (English)

    陶建平

    2012-01-01

    儿科患者发生的医院获得性菌血症,绝大多数与血管内装置相关,本文根据国内外指南和新的研究,对导管相关血流感染的流行病学、发病机制、诊断及预防和管理作一综述.%Most nosocomial bloodstream infections among pediatric patients are related to the usage of an intravascular device.This article reviewed catheter related bloodstream infections from aspects of epidemiology,pathogenesis,diagnosis,prevention and care based on guidelines and new research both in abroad and at home.

  12. The Outcomes of Using Colistin for Treating Multidrug Resistant Acinetobacter Species Bloodstream Infections

    OpenAIRE

    Lim, Seung-Kwan; Lee, Sang-Oh; Choi, Seong-Ho; Choi, Jae-Phil; Kim, Sung-Han; Jeong, Jin-Yong; Choi, Sang-Ho; Woo, Jun Hee; Kim, Yang Soo

    2011-01-01

    Despite the identification of Acinetobacter baumannii isolates that demonstrate susceptibility to only colistin, this antimicrobial agent was not available in Korea until 2006. The present study examined the outcomes of patients with multidrug resistant (MDR) Acinetobacter species bloodstream infection and who were treated with or without colistin as part of their regimen. The colistin group was given colistin as part of therapy once colistin became available in 2006. The non-colistin group w...

  13. Delays in Appropriate Antibiotic Therapy for Gram-Negative Bloodstream Infections: A Multicenter, Community Hospital Study

    OpenAIRE

    Moehring, Rebekah W.; Richard Sloane; Chen, Luke F.; Smathers, Emily C.; Schmader, Kenneth E.; Fowler, Vance G.; Weber, David J.; Sexton, Daniel J.; Anderson, Deverick J.

    2013-01-01

    BACKGROUND: Gram-negative bacterial bloodstream infection (BSI) is a serious condition with estimated 30% mortality. Clinical outcomes for patients with severe infections improve when antibiotics are appropriately chosen and given early. The objective of this study was to estimate the association of prior healthcare exposure on time to appropriate antibiotic therapy in patients with gram-negative BSI. METHOD: We performed a multicenter cohort study of adult, hospitalized patients with gram-ne...

  14. Experimental testing of the system resistance bloodstream component for the simulation line of the cardiovascular system

    Czech Academy of Sciences Publication Activity Database

    Chlup, Hynek; Pražák, Josef; Kovičková, S.

    Nečtiny : Computational Mechanics 2004, 2004, s. 169-174. ISBN 80-7043-314-0. [Computational mechanics 2004 /20./. Nečtiny (CZ), 08.11.2004-10.11.2004] R&D Projects: GA ČR GA106/04/1181 Institutional research plan: CEZ:AV0Z2076919 Keywords : simulation lines * systemresistance bloodstream component * experimental testing Subject RIV: BO - Biophysics

  15. Three Epidemics of Invasive Multidrug-Resistant Salmonella Bloodstream Infection in Blantyre, Malawi, 1998–2014

    OpenAIRE

    Feasey, Nicholas A.; Masesa, Clemens; Jassi, Chikondi; Faragher, E. Brian; Mallewa, Jane; Mallewa, Macpherson; MacLennan, Calman A.; Msefula, Chisomo; Robert S Heyderman; Gordon, Melita A.

    2015-01-01

    Background.  The Malawi Liverpool Wellcome Trust Clinical Research Programme (MLW) has routinely collected specimens for blood culture from febrile patients, and cerebrospinal fluid from patients with suspected meningitis, presenting to Queen Elizabeth Central Hospital (QECH), Blantyre, Malawi, since 1998. Methods.  We present bloodstream infection (BSI) and meningitis surveillance data from 1998 to 2014. Automated blood culture, manual speciation, serotyping, and antimicrobial susceptibility...

  16. Muscle Releases Alpha-Sarcoglycan Positive Extracellular Vesicles Carrying miRNAs in the Bloodstream

    OpenAIRE

    Michele Guescini; Barbara Canonico; Francesco Lucertini; Serena Maggio; Giosué Annibalini; Elena Barbieri; Francesca Luchetti; Stefano Papa; Vilberto Stocchi

    2015-01-01

    In the past few years, skeletal muscle has emerged as an important secretory organ producing soluble factors, called myokines, that exert either autocrine, paracrine or endocrine effects. Moreover, recent studies have shown that muscle releases microRNAs into the bloodstream in response to physical exercise. These microRNAs affect target cells, such as hormones and cytokines. The mechanisms underlying microRNA secretion are poorly characterized at present. Here, we investigated whether muscle...

  17. Tsukamurella catheter-related bloodstream infection in a pediatric patient with pulmonary hypertension

    Directory of Open Access Journals (Sweden)

    Kristen A. Wendorf

    2010-03-01

    Full Text Available Catheter-related bloodstream infections (CR-BSI are important complications in patients with long-term indwelling central venous catheters. In this report, we present the case of a 14-year-old male with pulmonary hypertension treated with continuous treprostinil infusion, who presented with a CR-BSI caused by a Tsukamurella species. This case highlights the potential for this unusual organism to cause infection in immunocompetent patients.

  18. Trends in paediatric bloodstream infections at a South African referral hospital

    OpenAIRE

    Dramowski, Angela; Mark F Cotton; Rabie, Helena; Whitelaw, Andrew

    2015-01-01

    Background The epidemiology of paediatric bloodstream infection (BSI) in Sub-Saharan Africa is poorly documented with limited data on hospital-acquired sepsis, impact of HIV infection, BSI trends and antimicrobial resistance. Methods We retrospectively reviewed paediatric BSI (0–14 years) at Tygerberg Children’s Hospital between 1 January 2008 and 31 December 2013 (excluding neonatal wards). Laboratory and hospital data were used to determine BSI rates, blood culture contamination, pathogen p...

  19. Epidemiology of Hospital-Acquired Urinary Tract-Related Bloodstream Infection at a University Hospital

    OpenAIRE

    Chang, Robert; Greene, M. Todd; Chenoweth, Carol E.; Kuhn, Latoya; Shuman, Emily; Rogers, Mary A M; Saint, Sanjay

    2011-01-01

    Little is known about the epidemiology of nosocomial urinary tract-related bloodstream infection. In a case series from an academic medical center, Enterococcus sp. (28.7%) and Candida sp. (19.6%) were the predominant microorganisms isolated, suggesting a potential shift from previously observed Gram-negative microorganisms. A case-fatality rate of 32.8% highlights the severity of this condition.

  20. Catheter-Related Bloodstream Infections (CR-BSI) in Geriatric Patients in Intensive Care Units.

    Science.gov (United States)

    Chernecky, Cynthia; Macklin, Denise; Blackburn, Paul

    2015-01-01

    Catheter-related bloodstream infections (CR-BSIs) are bloodstream infections that, through specific laboratory testing, identify the intravascular catheter as the source of the bloodstream infection. By 2015, the rate of elderly patients 80 years of age and older admitted to the intensive care unit (ICU) will represent 1 in 4 admissions. Approximately 80 000 CR-BSIs occur in ICUs annually, potentially resulting in as many as 56 000 CR-BSIs occurring in the geriatric ICU patient, with 20% of these cases resulting in death. To minimize the occurrence of CR-BSIs in these patients, specific knowledge about the geriatric patient will have to be factored into the ICU health care professional's practice, including the development of a vascular access plan, which includes selection of the correct device and proper insertion of that device along with an evidence-based care and maintenance program. Intensive care unit health care professionals may be at a loss when it comes to navigating the vast array of vascular access medical devices available today. The Healthcare and Technology Synergy framework can assist the ICU health care professional to logically review each vascular access device and select those devices that best meet patient needs. PMID:26039650

  1. Initial Assemblage of Bacterial Saccharic Fibrils and Element Deposition to Form an Immature Sheath in Cultured Leptothrix sp. Strain OUMS1

    Directory of Open Access Journals (Sweden)

    Mitsuaki Furutani

    2011-12-01

    Full Text Available In an aquatic environment, the genus Leptothrix produces an extracellular Fe- or Mn-encrusted tubular sheath composed of a complex hybrid of bacterial exopolymers and aqueous-phase inorganic elements. This ultrastructural study investigated initial assemblage of bacterial saccharic fibrils and subsequent deposition of aqueous-phase inorganic elements to form the immature sheath skeleton of cultured Leptothrix sp. strain OUMS1. After one day of culture, a globular and/or thread-like secretion was observed on the surface of the bacterial cell envelope, and secreted bodies were transported across the intervening space away from the cell to form an immature sheath skeleton comprising assembled and intermingled fibrils. Energy dispersive X-ray microanalysis and specific Bi-staining detected a distinguishable level of P, trace Si, and a notable amount of carbohydrates in the skeleton, but not Fe. By the second day, the skeleton was prominently thickened with an inner layer of almost parallel aligned fibrils, along with low level of Fe deposition, whereas an outer intermingled fibrous layer exhibited heavy deposition of Fe along with significant deposition of P and Si. These results indicate that basic sheath-construction proceeds in two steps under culture conditions: an initial assemblage of bacterial saccharic fibrils originated from the cell envelope and the subsequent deposition of aqueous-phase Fe, P, and Si.

  2. Control method exploration of nosocomial bloodstream infection and its effect evaluation

    Institute of Scientific and Technical Information of China (English)

    CHAI Wen-zhao; WANG Xiao-ting; ZHOU Jiong; LI Xin; LUO Hong-bo; LIU Da-wei

    2012-01-01

    Background Currently,slightly more than 50% of bloodstream infections (BSIs) are hospital acquired.When these infections occur in patients in intensive care units,they are associated with a high mortality rate,additional hospital days and excess hospital costs.Because of multifactor of nosocomial BSIs,measurements of control nosocomial BSIs are wide variety and lead to some confusion in practice.The aim of this study was to explore special way in accordance with self-hospital base on common principle.Methods In one ward of the Intensive Care Unit,Peking Union Medical College Hospital,at first,we divided the all operation about bloodstream way into three sections used as keypoints.By surveying keypoints respectively,some operation faults of blood way were discovered.For decreasing the mobidity of nosocomial BSls,some intervention measurements were executed.The rate of nosocomial BSIs was analyzed by chi-square test.Results According to the statistics from January to June,we received and cured 618 patients in total; among them,there were 13 cases of nosocomial BSI and the average occurrence was 2.3 cases/month.After intervention measurements from July to December 2011,we received and cured 639 patients in total with seven cases of nosocomial BSI,and the average occurrence was 1.2 cases/month (P <0.05).From January to April 2012,no nosocomial BSI occurred in the investigated ward.Conclusion Removing the operation faults of bloodstream way might decrease the nosocomial BSI rapidly and efficiently by utilizing a key point survey.

  3. Metagenomic characterization of 'Candidatus Defluviicoccus tetraformis strain TFO71', a tetrad-forming organism, predominant in an anaerobic-aerobic membrane bioreactor with deteriorated biological phosphorus removal.

    Science.gov (United States)

    Nobu, Masaru K; Tamaki, Hideyuki; Kubota, Kengo; Liu, Wen-Tso

    2014-09-01

    In an acetate-fed anaerobic-aerobic membrane bioreactor with deteriorated enhanced biological phosphorus removal (EBPR), Defluviicoccus-related tetrad-forming organisms (DTFO) were observed to predominate in the microbial community. Using metagenomics, a partial genome of the predominant DTFO, 'Candidatus Defluviicoccus tetraformis strain TFO71', was successfully constructed and characterized. Examining the genome confirmed the presence of genes related to the synthesis and degradation of glycogen and polyhydroxyalkanoate (PHA), which function as energy and carbon storage compounds. TFO71 and 'Candidatus Accumulibacter phosphatis' (CAP) UW-1 and CAP UW-2, representative polyphosphate-accumulating organisms (PAO), have PHA metabolism-related genes with high homology, but TFO71 has unique genes for PHA synthesis, gene regulation and granule management. We further discovered genes encoding DTFO polyphosphate (polyP) synthesis, suggesting that TFO71 may synthesize polyP under untested conditions. However, TFO71 may not activate these genes under EBPR conditions because the retrieved genome does not contain all inorganic phosphate transporters that are characteristic of PAOs (CAP UW-1, CAP UW-2, Microlunatus phosphovorus NM-1 and Tetrasphaera species). As a first step in characterizing EBPR-associated DTFO metabolism, this study identifies important differences between DTFO and PAO that may contribute to EBPR community competition and deterioration. PMID:24428681

  4. Synergistic algicidal effect and mechanism of two diketopiperazines produced by Chryseobacterium sp. strain GLY-1106 on the harmful bloom-forming Microcystis aeruginosa

    Science.gov (United States)

    Guo, Xingliang; Liu, Xianglong; Pan, Jianliang; Yang, Hong

    2015-10-01

    A potent algicidal bacterium isolated from Lake Taihu, Chryseobacterium sp. strain GLY-1106, produces two algicidal compounds: 1106-A (cyclo(4-OH-Pro-Leu)) and 1106-B (cyclo(Pro-Leu)). Both diketopiperazines showed strong algicidal activities against Microcystis aeruginosa, the dominant bloom-forming cyanobacterium in Lake Taihu. Interestingly, these two algicidal compounds functioned synergistically. Compared with individual treatment, combined treatment with cyclo(4-OH-Pro-Leu) and cyclo(Pro-Leu) significantly enhanced algicidal activity, accelerated the increase in intracellular reactive oxygen species (ROS) levels in M. aeruginosa, and further decreased the activities of antioxidases, effective quantum yield and maximal electron transport rate of M. aeruginosa. The results also showed that the algicidal characteristics of cyclo(4-OH-Pro-Leu) are distinct from those of cyclo(Pro-Leu). Cyclo(4-OH-Pro-Leu) mainly interrupted the flux of electron transport in the cyanobacterial photosynthetic system, whereas cyclo(Pro-Leu) mainly inhibited the activity of cyanobacterial intracellular antioxidases. A possible algicidal mechanism for the synergism between cyclo(4-OH-Pro-Leu) and cyclo(Pro-Leu) is proposed, which is in accordance with their distinct algicidal characteristics in individual and combined treatment. These findings suggest that synergism between algicidal compounds might be used as an effective strategy for the future control of Microcystis blooms.

  5. Risk and Prognosis of Bloodstream Infections among Patients on Chronic Hemodialysis: A Population-Based Cohort Study.

    Directory of Open Access Journals (Sweden)

    Lars Skov Dalgaard

    Full Text Available Infections are common complications among patients on chronic hemodialysis. This population-based cohort study aims to estimate risk and case fatality of bloodstream infection among chronic hemodialysis patients.In this population-based cohort study we identified residents with end-stage renal disease in Central and North Jutland, Denmark who had hemodialysis as first renal replacement therapy (hemodialysis patients during 1995-2010. For each hemodialysis patient, we sampled 19 persons from the general population matched on age, gender, and municipality. Information on positive blood cultures was obtained from regional microbiology databases. All persons were observed from cohort entry until first episode of bloodstream infection, emigration, death, or end of hemodialysis treatment, whichever came first. Incidence-rates and incidence-rate ratios were computed and risk factors for bloodstream infection assessed by Poisson regression. Case fatality was compared by Cox regression.Among 1792 hemodialysis patients and 33 618 matched population controls, we identified 461 and 1126 first episodes of bloodstream infection, respectively. Incidence rates of first episode of bloodstream infection were 13.7 (95% confidence interval (CI, 12.5-15.0 per 100 person-years among hemodialysis patients and 0.53 (95% CI, 0.50-0.56 per 100 person-years among population controls. In hemodialysis patients, the most common causative microorganisms were Staphylococcus aureus (43.8% and Escherichia coli (12.6%. The 30-day case fatality was similar among hemodialysis patients and population controls 16% (95% CI, 13%-20% vs. 18% (95% CI, 15%-20%.Hemodialysis patients have extraordinary high risk of bloodstream infection while short-term case fatality following is similar to that of population controls.

  6. Risk and Prognosis of Bloodstream Infections among Patients on Chronic Hemodialysis: A Population-Based Cohort Study

    Science.gov (United States)

    Skov Dalgaard, Lars; Nørgaard, Mette; Jespersen, Bente; Jensen-Fangel, Søren; Østergaard, Lars Jørgen; Schønheyder, Henrik Carl; Søgaard, Ole Schmeltz

    2015-01-01

    Background and Objectives Infections are common complications among patients on chronic hemodialysis. This population-based cohort study aims to estimate risk and case fatality of bloodstream infection among chronic hemodialysis patients. Methods In this population-based cohort study we identified residents with end-stage renal disease in Central and North Jutland, Denmark who had hemodialysis as first renal replacement therapy (hemodialysis patients) during 1995–2010. For each hemodialysis patient, we sampled 19 persons from the general population matched on age, gender, and municipality. Information on positive blood cultures was obtained from regional microbiology databases. All persons were observed from cohort entry until first episode of bloodstream infection, emigration, death, or end of hemodialysis treatment, whichever came first. Incidence-rates and incidence-rate ratios were computed and risk factors for bloodstream infection assessed by Poisson regression. Case fatality was compared by Cox regression. Results Among 1792 hemodialysis patients and 33 618 matched population controls, we identified 461 and 1126 first episodes of bloodstream infection, respectively. Incidence rates of first episode of bloodstream infection were 13.7 (95% confidence interval (CI), 12.5–15.0) per 100 person-years among hemodialysis patients and 0.53 (95% CI, 0.50–0.56) per 100 person-years among population controls. In hemodialysis patients, the most common causative microorganisms were Staphylococcus aureus (43.8%) and Escherichia coli (12.6%). The 30-day case fatality was similar among hemodialysis patients and population controls 16% (95% CI, 13%–20%) vs. 18% (95% CI, 15%–20%). Conclusions Hemodialysis patients have extraordinary high risk of bloodstream infection while short-term case fatality following is similar to that of population controls. PMID:25910221

  7. Muscle Releases Alpha-Sarcoglycan Positive Extracellular Vesicles Carrying miRNAs in the Bloodstream.

    Directory of Open Access Journals (Sweden)

    Michele Guescini

    Full Text Available In the past few years, skeletal muscle has emerged as an important secretory organ producing soluble factors, called myokines, that exert either autocrine, paracrine or endocrine effects. Moreover, recent studies have shown that muscle releases microRNAs into the bloodstream in response to physical exercise. These microRNAs affect target cells, such as hormones and cytokines. The mechanisms underlying microRNA secretion are poorly characterized at present. Here, we investigated whether muscle tissue releases extracellular vesicles (EVs, which carry microRNAs in the bloodstream under physiological conditions such as physical exercise. Using density gradient separation of plasma from sedentary and physically fit young men we found EVs positive for TSG101 and alpha-sarcoglycan (SGCA, and enriched for miR-206. Cytometric analysis showed that the SGCA+ EVs account for 1-5% of the total and that 60-65% of these EVs were also positive for the exosomal marker CD81. Furthermore, the SGCA-immuno captured sub-population of EVs exhibited higher levels of the miR-206/miR16 ratio compared to total plasma EVs. Finally, a significant positive correlation was found between the aerobic fitness and muscle-specific miRNAs and EV miR-133b and -181a-5p were significantly up-regulated after acute exercise. Thus, our study proposes EVs as a novel means of muscle communication potentially involved in muscle remodeling and homeostasis.

  8. Determination of germ tube, phospholipase, and proteinase production by bloodstream isolates of Candida albicans

    Directory of Open Access Journals (Sweden)

    Antonella Souza Mattei

    2013-06-01

    Full Text Available Introduction Candida albicans is a commensal and opportunistic agent that causes infection in immunocompromised individuals. Several attributes contribute to the virulence and pathogenicity of this yeast, including the production of germ tubes (GTs and extracellular hydrolytic enzymes, particularly phospholipase and proteinase. This study aimed to investigate GT production and phospholipase and proteinase activities in bloodstream isolates of C. albicans. Methods One hundred fifty-three C. albicans isolates were obtained from blood samples and analyzed for GT, phospholipase, and proteinase production. The assays were performed in duplicate in egg yolk medium containing bovine serum albumin and human serum. Results Detectable amounts of proteinase were produced by 97% of the isolates, and 78% of the isolates produced phospholipase. GTs were produced by 95% of the isolates. A majority of the isolates exhibited low levels of phospholipase production and high levels of proteinase production. Conclusions Bloodstream isolates of C. albicans produce virulence factors such as GT and hydrolytic enzymes that enable them to cause infection under favorable conditions.

  9. Antifungal susceptibility of invasive Candida bloodstream isolates from the Asia-Pacific region.

    Science.gov (United States)

    Tan, Thean Yen; Hsu, Li Yang; Alejandria, Marissa M; Chaiwarith, Romanee; Chinniah, Terrence; Chayakulkeeree, Methee; Choudhury, Saugata; Chen, Yen Hsu; Shin, Jong Hee; Kiratisin, Pattarachai; Mendoza, Myrna; Prabhu, Kavitha; Supparatpinyo, Khuanchai; Tan, Ai Ling; Phan, Xuan Thi; Tran, Thi Thanh Nga; Nguyen, Gia Binh; Doan, Mai Phuong; Huynh, Van An; Nguyen, Su Minh Tuyet; Tran, Thanh Binh; Van Pham, Hung

    2016-07-01

    Bloodstream infections caused by Candida species are of increasing importance and associated with significant mortality. We performed a multi-centre prospective observational study to identify the species and antifungal susceptibilities of invasive bloodstream isolates of Candida species in the Asia-Pacific region. The study was carried out over a two year period, involving 13 centers from Brunei, Philippines, Singapore, South Korea, Taiwan, Thailand, and Vietnam. Identification of Candida species was performed at each study center, and reconfirmed at a central laboratory. Susceptibility testing was performed using a commercial broth dilution panel (Sensititre YeastOne YST-010, Thermofisher, United Kingdom) with susceptibility categorisation (S = susceptible, S-DD = susceptible dose-dependent) applied using breakpoints from the Clinical Laboratory Standards Institute. Eight hundred and sixty-one Candida isolates were included in the study. The most common species were C. albicans (35.9%), C. tropicalis (30.7%), C. parapsilosis (15.7%), and C. glabrata (13.6%). Non-albicans species exceeded C. albicans species in centers from all countries except Taiwan. Fluconazole susceptibility was almost universal for C. albicans (S = 99.7%) but lower for C. tropicalis (S = 75.8%, S-DD = 6.1%), C. glabrata (S-DD = 94.9%), and C. parapsilosis (S = 94.8%). Echinocandins demonstrated high rates of in vitro susceptibility (S>99%) against C. albicans, C. tropicalis, and C. parapsilosis This study demonstrates that non-albicans species are the most common isolates from bloodstream infections in most countries in the Asia-Pacific region, with C. tropicalis as the predominant species. Because of the prevalence of reduced susceptibility to fluconazole in non-albicans species, the study indicates that echinocandins should be the antifungal of choice in clinically unstable or high-risk patients with documented candidemia. PMID:26868904

  10. The Aetiology of the Bloodstream Infections in the Patients Who Presented to a Tertiary Care Teaching Hospital in Kathmandu, Nepal

    OpenAIRE

    Pandey, Santwana; Raza, Shahid; Bhatta, Chandra Prakash

    2013-01-01

    Background: Bloodstream infections are associated with a significant patient morbidity and mortality. The detection of microorganisms in the patients’ blood has a great diagnostic and prognostic significance. The early positive results provide valuable diagnostic information, based on which the appropriate antimicrobial therapy can be initiated.

  11. Patients with Central Lines — What You Need to Know to Avoid a Bloodstream Infection

    Centers for Disease Control (CDC) Podcasts

    2011-03-01

    This podcast is based on the March, 2011 CDC Vital Signs report which indicates bloodstream infections in patients with central lines are largely preventable when healthcare providers use CDC-recommended infection control steps.  Created: 3/1/2011 by Centers for Disease Control and Prevention (CDC).   Date Released: 3/1/2011.

  12. [Prevention of catheter-related bloodstream infections in the operation room].

    Science.gov (United States)

    Ema, Yoshiaki; Nishiwaki, Kimitoshi

    2010-05-01

    Catheter-related bloodstream infections (CRBSIs) are recognized as an important and serious problem, especially in an intensive care unit (ICU), since they have far higher infection rates compared to those for other type of intravascular devices. However, in the operation room, there seems to be little concern among anesthesiologists regarding this problem. It is important for anesthesiologists to understand that CRBSIs can be prevented or reduced by evidence-based interventions such as hand hygiene, education in hand washing and alcohol-based hand rubbing, sterile catheter care techniques, proper skin disinfection, maximal barrier precautions during catheter insertion, choice of subclavian vein placement, avoidance of femoral vein placement, and removal of an unnecessary catheter. This evidence is based mainly on findings in ICU patients, but introduction of these interventions into operation rooms may be very useful for reducing perioperative CRBSIs. PMID:20486568

  13. JVG9, a benzimidazole derivative, alters the surface and cytoskeleton of Trypanosoma cruzi bloodstream trypomastigotes

    Science.gov (United States)

    Díaz-Chiguer, Dylan L; Hernández-Luis, Francisco; Nogueda-Torres, Benjamín; Castillo, Rafael; Reynoso-Ducoing, Olivia; Hernández-Campos, Alicia; Ambrosio, Javier R

    2014-01-01

    Trypanosoma cruzi has a particular cytoskeleton that consists of a subpellicular network of microtubules and actin microfilaments. Therefore, it is an excellent target for the development of new anti-parasitic drugs. Benzimidazole 2-carbamates, a class of well-known broad-spectrum anthelmintics, have been shown to inhibit the in vitro growth of many protozoa. Therefore, to find efficient anti-trypanosomal (trypanocidal) drugs, our group has designed and synthesised several benzimidazole derivatives. One, named JVG9 (5-chloro-1H-benzimidazole-2-thiol), has been found to be effective against T. cruzi bloodstream trypomastigotes under both in vitro and in vivo conditions. Here, we present the in vitro effects observed by laser scanning confocal and scanning electron microscopy on T. cruzi trypomastigotes. Changes in the surface and the distribution of the cytoskeletal proteins are consistent with the hypothesis that the trypanocidal activity of JVG9 involves the cytoskeleton as a target. PMID:25317703

  14. Metagenomic analysis of bloodstream infections in patients with acute leukemia and therapy-induced neutropenia.

    Science.gov (United States)

    Gyarmati, P; Kjellander, C; Aust, C; Song, Y; Öhrmalm, L; Giske, C G

    2016-01-01

    Leukemic patients are often immunocompromised due to underlying conditions, comorbidities and the effects of chemotherapy, and thus at risk for developing systemic infections. Bloodstream infection (BSI) is a severe complication in neutropenic patients, and is associated with increased mortality. BSI is routinely diagnosed with blood culture, which only detects culturable pathogens. We analyzed 27 blood samples from 9 patients with acute leukemia and suspected BSI at different time points of their antimicrobial treatment using shotgun metagenomics sequencing in order to detect unculturable and non-bacterial pathogens. Our findings confirm the presence of bacterial, fungal and viral pathogens alongside antimicrobial resistance genes. Decreased white blood cell (WBC) counts were associated with the presence of microbial DNA, and was inversely proportional to the number of sequencing reads. This study could indicate the use of high-throughput sequencing for personalized antimicrobial treatments in BSIs. PMID:26996149

  15. Bloodstream infection among children presenting to a general hospital outpatient clinic in urban Nepal.

    Directory of Open Access Journals (Sweden)

    Rahul Pradhan

    Full Text Available BACKGROUND: There are limited data on the etiology and characteristics of bloodstream infections in children presenting in hospital outpatient settings in South Asia. Previous studies in Nepal have highlighted the importance of murine typhus as a cause of febrile illness in adults and enteric fever as a leading bacterial cause of fever among children admitted to hospital. METHODS: We prospectively studied a total of 1084 febrile children aged between 2 months and 14 years presenting to a general hospital outpatient department in Kathmandu Valley, Nepal, over two study periods (summer and winter. Blood from all patients was tested by conventional culture and by real-time PCR for Rickettsia typhi. RESULTS: Putative etiological agents for fever were identified in 164 (15% patients. Salmonella enterica serovar Typhi (S. Typhi was identified in 107 (10%, S. enterica serovar Paratyphi A (S. Paratyphi in 30 (3%, Streptococcus pneumoniae in 6 (0.6%, S. enterica serovar Typhimurium in 2 (0.2%, Haemophilus influenzae type b in 1 (0.1%, and Escherichia coli in 1 (0.1% patient. S. Typhi was the most common organism isolated from blood during both summer and winter. Twenty-two (2% patients were PCR positive for R. typhi. No significant demographic, clinical and laboratory features distinguished culture positive enteric fever and murine typhus. CONCLUSIONS: Salmonella infections are the leading cause of bloodstream infection among pediatric outpatients with fever in Kathmandu Valley. Extension of immunization programs against invasive bacterial disease to include the agents of enteric fever and pneumococcus could improve the health of children in Nepal.

  16. Systematic strain construction and process development: Xylitol production by Saccharomyces cerevisiae expressing Candida tenuis xylose reductase in wild-type or mutant form.

    Science.gov (United States)

    Pratter, S M; Eixelsberger, T; Nidetzky, B

    2015-12-01

    A novel Saccharomyces cerevisiae whole-cell biocatalyst for xylitol production based on Candida tenuis xylose reductase (CtXR) is presented. Six recombinant strains expressing wild-type CtXR or an NADH-specific mutant were constructed and evaluated regarding effects of expression mode, promoter strength, biocatalyst concentration and medium composition. Intracellular XR activities ranged from 0.09 U mgProt(-1) to 1.05 U mgProt(-1) but did not correlate with the strains' xylitol productivities, indicating that other factors limited xylose conversion in the high-activity strains. The CtXR mutant decreased the biocatalyst's performance, suggesting use of the NADPH-preferring wild-type enzyme when (semi-)aerobic conditions are applied. In a bioreactor process, the best-performing strain converted 40 g L(-1) xylose with an initial productivity of 1.16 g L(-1)h(-1) and a xylitol yield of 100%. The obtained results underline the potential of CtXR wild-type for xylose reduction and point out parameters to improve "green" xylitol production. PMID:26452180

  17. Bacillus halodurans Strain C125 Encodes and Synthesizes Enzymes from Both Known Pathways To Form dUMP Directly from Cytosine Deoxyribonucleotides

    DEFF Research Database (Denmark)

    Oehlenschlæger, Christian Berg; Løvgreen, Monika Nøhr; Reinauer, Eva;

    2015-01-01

    Analysis of the genome of Bacillus halodurans strain C125 indicated that two pathways leading from a cytosine deoxyribonucleotide to dUMP, used for dTMP synthesis, were encoded by the genome of the bacterium. The genes that were responsible, the comEB gene and the dcdB gene, encoding dCMP deaminase...

  18. Ultrathin highly uniform Ni(Al) germanosilicide layer with modulated B8 type Ni5(SiGe)3 phase formed on strained Si1−xGex layers

    International Nuclear Information System (INIS)

    We present a method to form ultrathin highly uniform Ni(Al) germanosilicide layers on compressively strained Si1−xGex substrates and their structural characteristics. The uniform Ni(Al) germanosilicide film is formed with Ni/Al alloy at an optimized temperature of 400 °C with an optimized Al atomic content of 20 at. %. We find only two kinds of grains in the layer. Both grains show orthogonal relationship with modified B8 type phase. The growth plane is identified to be (10-10)-type plane. After germanosilicidation the strain in the rest Si1−xGex layer is conserved, which provides a great advantage for device application

  19. Ultrathin highly uniform Ni(Al) germanosilicide layer with modulated B8 type Ni{sub 5}(SiGe){sub 3} phase formed on strained Si{sub 1−x}Ge{sub x} layers

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Linjie; Xu, Dawei [Peter Grünberg Institute 9, Forschungzentrum Jülich, 52425 Jülich (Germany); State Key Laboratory of Functional Material for Informatics, Shanghai Institute of Microsystem and Information Technology, CAS, Shanghai 200050 (China); University of Chinese Academy of Sciences, Beijing 100049 (China); Jin, Lei [Peter Grünberg Institute 5, Forschungszentrum Jülich, 52425 Jülich (Germany); Knoll, Lars; Wirths, Stephan; Nichau, Alexander; Buca, Dan; Mussler, Gregor; Holländer, Bernhard; Zhao, Qing-Tai, E-mail: q.zhao@fz-juelich.de; Mantl, Siegfried [Peter Grünberg Institute 9, Forschungzentrum Jülich, 52425 Jülich (Germany); Feng Di, Zeng; Zhang, Miao [State Key Laboratory of Functional Material for Informatics, Shanghai Institute of Microsystem and Information Technology, CAS, Shanghai 200050 (China)

    2013-12-02

    We present a method to form ultrathin highly uniform Ni(Al) germanosilicide layers on compressively strained Si{sub 1−x}Ge{sub x} substrates and their structural characteristics. The uniform Ni(Al) germanosilicide film is formed with Ni/Al alloy at an optimized temperature of 400 °C with an optimized Al atomic content of 20 at. %. We find only two kinds of grains in the layer. Both grains show orthogonal relationship with modified B8 type phase. The growth plane is identified to be (10-10)-type plane. After germanosilicidation the strain in the rest Si{sub 1−x}Ge{sub x} layer is conserved, which provides a great advantage for device application.

  20. Enterotoxigenicity of Mature 45-Kilodalton and Processed 35-Kilodalton Forms of Hemagglutinin Protease Purified from a Cholera Toxin Gene-Negative Vibrio cholerae Non-O1, Non-O139 Strain

    OpenAIRE

    Ghosh, A; Saha, D. R.; Hoque, K. M.; Asakuna, M.; Yamasaki, S.; Koley, H; Das, S. S.; Chakrabarti, M K; Pal, A.

    2006-01-01

    Cholera toxin gene-negative Vibrio cholerae non-O1, non-O139 strain PL-21 is the etiologic agent of cholera-like syndrome. Hemagglutinin protease (HAP) is one of the major secretory proteins of PL-21. The mature 45-kDa and processed 35-kDa forms of HAP were purified in the presence and absence of EDTA from culture supernatants of PL-21. Enterotoxigenicities of both forms of HAP were tested in rabbit ileal loop (RIL), Ussing chamber, and tissue culture assays. The 35-kDa HAP showed hemorrhagic...

  1. The increased risks of death and extra lengths of hospital and ICU stay from hospital-acquired bloodstream infections: a case–control study

    OpenAIRE

    Barnett, Adrian G.; Page, Katie; Campbell, Megan; Martin, Elizabeth; Rashleigh-Rolls, Rebecca; Halton, Kate; PATERSON, DAVID L.; Hall, Lisa; Jimmieson, Nerina; White, Katherine; Graves, Nicholas

    2013-01-01

    Objectives Hospital-acquired bloodstream infections are known to increase the risk of death and prolong hospital stay, but precise estimates of these two important outcomes from well-designed studies are rare, particularly for non-intensive care unit (ICU) patients. We aimed to calculate accurate estimates, which are vital for estimating the economic costs of hospital-acquired bloodstream infections. Design Case–control study. Setting 9 Australian public hospitals. Participants All the patien...

  2. Healthcare-associated Staphylococcus aureus bloodstream infection: length of stay, attributable mortality, and additional direct costs.

    Science.gov (United States)

    Primo, Mariusa Gomes Borges; Guilarde, Adriana Oliveira; Martelli, Celina M Turchi; Batista, Lindon Johnson de Abreu; Turchi, Marília Dalva

    2012-01-01

    This study aimed to determine the excess length of stay, extra expenditures, and attributable mortality to healthcare-associated S. aureus bloodstream infection (BSI) at a teaching hospital in central Brazil. The study design was a matched (1:1) case-control. Cases were defined as patients >13 years old, with a healthcare-associated S. aureus BSI. Controls included patients without an S. aureus BSI, who were matched to cases by gender, age (± 7 years), morbidity, and underlying disease. Data were collected from medical records and from the Brazilian National Hospital Information System (Sistema de Informações Hospitalares do Sistema Único de Saúde - SIH/SUS). A Wilcoxon rank sum test was performed to compare length of stay and costs between cases and controls. Differences in mortality between cases and controls were compared using McNemar's tests. The Mantel-Haenzel stratified analysis was performed to compare invasive device utilization. Data analyses were conducted using Epi Info 6.0 and Statistical Package for Social Sciences (SPSS 13.0). 84 case-control pairs matched by gender, age, admission period, morbidity, and underlying disease were analyzed. The mean lengths of hospital stay were 48.3 and 16.2 days for cases and controls, respectively (p<0.01), yielding an excess hospital stay among cases of 32.1 days. The excess mortality among cases compared to controls that was attributable to S. aureus bloodstream infection was 45.2%. Cases had a higher risk of dying compared to controls (OR 7.3, 95% CI 3.1-21.1). Overall costs of hospitalization (SIH/SUS) reached US$ 123,065 for cases versus US$ 40,247 for controls (p<0.01). The cost of antimicrobial therapy was 6.7 fold higher for cases compared to controls. Healthcare-associated S. aureus BSI was associated with statistically significant increases in length of hospitalization, attributable mortality, and economic burden. Implementation of measures to minimize the risk of healthcare-associated bacterial

  3. Isolation, Cultural Maintenance, and Taxonomy of a Sheath-Forming Strain of Leptothrix discophora and Characterization of Manganese-Oxidizing Activity Associated with the Sheath

    OpenAIRE

    Emerson, David; Ghiorse, William C.

    1992-01-01

    Leptothrix discophora SP-6 was isolated from the outflow reservoir of an artificial iron seep. Its sheathforming phenotype was maintained by slow growth in a mineral salts-vitamin-pyruvate medium under minimal aeration at 20 to 25°C. A sheathless variant, SP-6(sl), was isolated from smooth colonies that appeared on spread plates after rapid growth of SP-6 in well-aerated cultures. SP-6 and SP-6(sl) are closely related but not identical to the previously studied sheathless strain SS-1 (ATCC 43...

  4. The application of High Resolution Melting Analysis (HRMA) for rapid detection of bacteria responsible for bloodstream infections

    OpenAIRE

    Ozbak, Hani

    2013-01-01

    Abstract: Background: The diagnosis of bloodstream infection is a significant challenge for healthcare providers and is often associated with severe illness (sepsis) and poor outcomes. Rapid detection and identification of pathogens followed by characterisation of antibiotic resistance could help direct early treatment and improve patient care. Standard blood culture methods, which usually take 2-5 days to complete, can confirm if there is a bacteraemia or not in suspected patients. However, ...

  5. Monitoring Quality of Care Through Linkage of Administrative Data: National Trends in Bloodstream Infection in UK PICUs 2003-2012

    OpenAIRE

    Harron, K.; Parslow, R.; Mok, Q; Tibby, S. M.; WADE, A.; Muller-Pebody, B; Gilbert, R.

    2015-01-01

    Objectives: Interventions to reduce hospital-acquired bloodstream infection (BSI) have succeeded in reducing rates in US paediatric intensive care units (PICUs) but there is a lack of evidence for the impact of similar interventions in the UK. We assessed variation in BSI rates within and between PICUs over a 10-year period, during which time infection control strategies (care bundles) were implemented. Design: Observational study linking laboratory data to national audit data of paediatric i...

  6. Risk-adjusted monitoring of blood-stream infection in paediatric intensive care: a data linkage study

    OpenAIRE

    Harron, K.; WADE, A.; Muller-Pebody, B; Goldstein, H.; Parslow, R.; Gray, J.; Hartley, J. C.; Mok, Q; Gilbert, R.

    2013-01-01

    PURPOSE: National monitoring of variation in the quality of infection control in paediatric intensive care units (PICUs) requires comparisons of risk-adjusted rates. To inform the development of a national monitoring system, we evaluated the effects of risk-adjustment and outcome definition on comparisons of blood-stream infection (BSI) rates in PICU, using linkage of risk-factor data captured by national audit (PICANet) with laboratory records of BSI. METHODS: Admission data for two children...

  7. Magnet® Hospital Recognition Linked to Lower Central Line-Associated Bloodstream Infection Rates.

    Science.gov (United States)

    Barnes, Hilary; Rearden, Jessica; McHugh, Matthew D

    2016-04-01

    Central-line-associated bloodstream infections (CLABSI) are among the deadliest heathcare-associated infections, with an estimated 12-25% mortality rate. In 2014, the Centers for Medicare and Medicaid Services (CMS) began to penalize hospitals for poor performance with respect to selected hospital-acquired conditions, including CLABSI. A structural factor associated with high-quality nursing care and better patient outcomes is The Magnet Recognition Program®. The purpose of this study was to explore the relationship between Magnet status and hospital CLABSI rates. We used propensity score matching to match Magnet and non-Magnet hospitals with similar hospital characteristics. In a matched sample of 291 Magnet hospitals and 291 non-Magnet hospitals, logistic regression models were used to examine whether there was a link between Magnet status and CLABSI rates. Both before and after matching, Magnet hospital status was associated with better (lower than the national average) CLABSI rates (OR = 1.60, 95%CI: 1.10, 2.33 after matching). While established programs such as Magnet recognition are consistently correlated with high-quality nursing work environments and positive patient outcomes, additional research is needed to determine whether Magnet designation produces positive patient outcomes or rewards existing excellence. PMID:26809115

  8. Survey of physicians' perspectives and knowledge about diagnostic tests for bloodstream infections.

    Directory of Open Access Journals (Sweden)

    Rosemary C She

    Full Text Available Physicians rely on blood culture to diagnose bloodstream infections (BSI despite its limitations. As new technologies emerge for rapid BSI diagnosis, optimization of their application to patient care requires an understanding of clinicians' perspectives on BSI diagnosis and how a rapid test would influence medical decisions.We administered a 26-question survey to practitioners in infectious diseases/microbiology, critical care, internal medicine, and hematology/oncology services in USA and Germany about current standards in diagnosing and treating BSI and a hypothetical rapid BSI test.Responses from 242 providers had roughly equal representation across specialties. For suspected BSI patients, 78% of practitioners would administer empiric broad spectrum antibiotics although they estimated, on average, that 31% of patients received incorrect antibiotics while awaiting blood culture results. The ability of blood culture to rule in or rule out infection was very/extremely acceptable in 67% and 36%, respectively. Given rapid test results, 60-87% of practitioners would narrow the spectrum of antimicrobial therapy depending on the microorganism detected, with significantly higher percentages when resistance determinants were also tested. Over half of respondents felt a rapid test would be very/extremely influential on clinical practice.Limitations of blood culture were perceived as a barrier to patient care. A rapid test to diagnose BSI would impact clinical practice, but the extent of impact may be limited by prevailing attitudes and practices. Opportunities exist for interventions to influence practitioners' behaviors in BSI management particularly with emergence of newer diagnostic tests.

  9. Risk factors and outcomes of imipenem-resistant Acinetobacter bloodstream infection in North-eastern Malaysia

    Institute of Scientific and Technical Information of China (English)

    Zakuan Zainy Deris; Mohd Nazri Shafei; Azian Harun

    2011-01-01

    Objective: To determine the risk factors and outcomes of imipenem-resistant Acinetobacterbaumannii (IRAB) bloodstream infection (BSI) cases, since there is very little publication on Acinetobacter baumannii infections from Malaysia. Methods: A cross sectional study of 41 cases (73.2%) of imipenem-sensitive Acinetobacter baumanii (ISAB) and 15 cases (26.8%) of IRAB was conducted in a teaching hospital which was located at North-Eastern state of Malaysia. Results:There was no independent risk factor for IRAB BSI identified but IRAB BSI was significantly associated with longer bacteraemic days [OR 1.23 (95% CI 1.01, 1.50)]. Although prior use of carbepenems and cephalosporin were higher among IRAB than ISAB group, statistically they were not significant. There was no significant difference in term of outcomes between the two groups. Conclusions: Although statistically not significant, this analysis compliments previous publication highlighting the importance of appropriate empiric antibiotic usage in hospital especially carbepenems and need further evaluation with bigger subjects.

  10. The Validation of a Novel Surveillance System for Monitoring Bloodstream Infections in the Calgary Zone

    Science.gov (United States)

    Leal, Jenine R.; Gregson, Daniel B.; Church, Deirdre L.; Henderson, Elizabeth A.; Ross, Terry; Laupland, Kevin B.

    2016-01-01

    Background. Electronic surveillance systems (ESSs) that utilize existing information in databases are more efficient than conventional infection surveillance methods. The objective was to assess an ESS for bloodstream infections (BSIs) in the Calgary Zone for its agreement with traditional medical record review. Methods. The ESS was developed by linking related data from regional laboratory and hospital administrative databases and using set definitions for excluding contaminants and duplicate isolates. Infections were classified as hospital-acquired (HA), healthcare-associated community-onset (HCA), or community-acquired (CA). A random sample of patients from the ESS was then compared with independent medical record review. Results. Among the 308 patients selected for comparative review, the ESS identified 318 episodes of BSI of which 130 (40.9%) were CA, 98 (30.8%) were HCA, and 90 (28.3%) were HA. Medical record review identified 313 episodes of which 136 (43.4%) were CA, 97 (30.9%) were HCA, and 80 (25.6%) were HA. Episodes of BSI were concordant in 304 (97%) cases. Overall, there was 85.5% agreement between ESS and medical record review for the classification of where BSIs were acquired (kappa = 0.78, 95% Confidence Interval: 0.75–0.80). Conclusion. This novel ESS identified and classified BSIs with a high degree of accuracy. This system requires additional linkages with other related databases.

  11. Antimicrobial-impregnated catheters for the prevention of catheter-related bloodstream infections.

    Science.gov (United States)

    Lorente, Leonardo

    2016-05-01

    Central venous catheters are commonly used in critically ill patients. Such catheterization may entail mechanical and infectious complications. The interest in catheter-related infection lies in the morbidity, mortality and costs that it involved. Numerous contributions have been made in the prevention of catheter-related infection and the current review focuses on the possible current role of antimicrobial impregnated catheters to reduce catheter-related bloodstream infections (CRBSI). There is evidence that the use of chlorhexidine-silver sulfadiazine (CHSS), rifampicin-minocycline, or rifampicin-miconazol impregnated catheters reduce the incidence of CRBSI and costs. In addition, there are some clinical circumstances associated with higher risk of CRBSI, such as the venous catheter access and the presence of tracheostomy. Current guidelines for the prevention of CRBSI recommended the use of a CHSS or rifampicin-minocycline impregnated catheter in patients whose catheter is expected to remain in place > 5 d and if the CRBSI rate has not decreased after implementation of a comprehensive strategy to reduce it. PMID:27152256

  12. Effects of ferrous sulfate, inoculum history, and anionic form on lead, zinc, and copper toxicity to Acidithiobacillus caldus strain BC13

    Energy Technology Data Exchange (ETDEWEB)

    John E. Aston; William A. Apel; Brady D. Lee; Brent M. Peyton

    2010-12-01

    The current study reports the single and combined toxicities of Pb, Zn, and Cu to Acidithiobacillus caldus strain BC13. The observed half-maximal inhibitory concentrations (IC50),?±?95% confidence intervals, for Pb, Zn, and Cu were 0.9?±?0.1?mM, 39?±?0.5?mM, and 120?±?8?mM, respectively. The observed minimum inhibitory concentrations (MIC) for Pb, Zn, and Cu were 7.5?mM, 75?mM, and 250?mM, respectively. When metals were presented in binary mixtures, the toxicities were less than additive. For example, when 50% of the Pb MIC and 50% of the Cu MIC were presented together, the specific growth rate was inhibited by only 59?±?3%, rather than 100%. In addition, the presence of ferrous iron in the growth media decreased Pb and Zn toxicity to A. caldus strain BC13. The importance of inoculum history was evaluated by pre-adapting cultures through subsequent transfers in the presence of Pb, Zn, and Cu at their respective IC50s. After pre-adaptation, cultures had specific growth rates 39?±?11, 32?±?7, and 28?±?12% higher in the presence of Pb, Zn, and Cu IC50s, respectively, compared with cultures that had not been pre-adapted. In addition, when cells exposed to the MICs of Pb, Zn, and Cu were harvested, washed, and re-inoculated into fresh, metal-free medium, they grew, showing that the cells remained viable with little residual toxicity. Finally, metal chlorides showed more toxicity than metal sulfates, and studies using sodium chloride or a mixture of metal sulfates and sodium chloride suggested that this was attributable to an additive combination of the metal and chloride toxicities. Environ. Toxicol. Chem. 2010;29:2669–2675. © 2010 SETAC

  13. Comparative analysis between stress-and strain-based forming limit diagrams for aluminum alloy sheet 1060%基于应变和应力的1060铝合金板成形极限比较分析

    Institute of Scientific and Technical Information of China (English)

    方刚; 刘清俊; 雷丽萍; 曾攀

    2012-01-01

    The forming limit diagram (FLD) and forming limit stress diagram (FLSD) of aluminium alloy 1060 under linear and nonlinear strain paths are investigated.The calculation of FLSD is based on experimental FLD using the method proposed by Stoughton.Different from the FLD that varies with the strain path,the FLSD is not sensitive to the strain path.Therefore,FLSD is convenient as a forming limit criterion for multi-stage sheet forming.The influences of the material's yield criteria on FLSD are also discussed by comparison of the Hill's 48,Hill's 79 and Hosford non-quadratic criterion.The impacts of material hardening laws (Voce and Swift models) on translation of FLD and FLSD are analyzed.The Voce hardening law and the Hosford yield criterion are appropriate for the FLSD calculation of the aluminium alloy 1060.The stress calculation program and display interfaces of FLD and FLSD are developed on MATLAB,where the strain data can be input from experiment measurement or FEM calculations.%通过线性和非线性应变路径的板料成形实验,研究1060铝合金的成形极限图(FLD)和成形应力极限图(FLSD).利用Stoughton方法,基于板料成形实验中测得的应变数据,计算得到了FLSD.结果表明:对于1060铝合金板料,FLD与应变路径是相关的,而FLSD对应变路径却不敏感,所以FLSD可以很方便地作为多道次板料成形的极限准则.通过对比Hill's 48,Hill's 79和Hosford非二次式3种材料屈服准则,分析了它们从FLD到FLSD转换对应力计算的影响,Hosford非二次式屈服准则更适合1060铝合金的FLSD计算.通过与单向拉伸实验数据的比较,材料硬化准则中Voce硬化准则比Swift准则更适合该材料.在MATLAB上开发了由应变到应力的计算以及FLD和FLSD显示的程序,通过输入实验中测得的应变数据可以得出FLD和FLSD.

  14. 血液病粒细胞缺乏患者医院血流感染的回顾性临床分析%Nosocomial bloodstream infections in neutropenic hematological patients:a retrospective clinical study

    Institute of Scientific and Technical Information of China (English)

    汤丽苑; 俞康

    2012-01-01

    OBJECTIVE To investigate the risk factors of nosocomial bloodstream infections in hematological patients with neutropenia, and analyze the distribution and antibiotic resistance of the pathogenic bacteria so as to provide basis for reduling the in cidence of blood stream infections and the mortality. METHODS A retrospective analysis of neutropenic patients with nosocomial bloodstream infections was performed from 2009 to 2011. RESULTS 1:2 matched case-control study showed the immunosuppressive therapy(OR = 6. 967),neutrophi<0. 2 ×109/L(OR = 28. 306), the duration of neutropenia<7 days(OR = 4. 383),MASCC risk index<21 scores (Multinational Association of Supportive Care of Cancer risk index score, OR — &9. 002) were important risk factors of nosocomial bloodstream infections in hematological patients with neutropenia; of totally 62 strains of pathogens isolated, gram-negative bacteria accounted for 64. 5%. gram-positive bacteria accounted for 27. 4%, and fungi accounted for 8. 1% , the most common pathogenic organisms identified were Escherichia coli(30. 6%) , Klebsiella pneumoniae (21. 0%) and Staphylococcus aureus (8. 1%) s the detection rates of ESBLs-producing strains of E.coli and K. pneumoniae were 47. 4% and 30. 8%, respectively. CONCLUSION It is critical to take effective measures and monitor the local bacterial epidemiology to control or decrease the morbidity and mortality of nosocomial bloodstream infections in hematological patients with neutropenia.%目的 分析血液病粒细胞缺乏患者血流感染的危险因素、病原菌分布及耐药性,为减少其血流感染的发病率及病死率提供依据.方法 对医院2009-2011年61例血液科粒细胞缺乏患者并发医院血流感染进行回顾性临床分析.结果 免疫抑制剂应用、中性粒细胞<0.2×109/L、中性粒细胞缺乏时间<7 d及癌症支持疗法多国学会风险指数<21分是血液病粒细胞缺乏患者医院血流感染的

  15. Penetration barrier contributes to bacterial biofilm-associated resistance against only select antibiotics, and exhibits genus-, strain- and antibiotic-specific differences.

    Science.gov (United States)

    Singh, Rachna; Sahore, Simmi; Kaur, Preetinder; Rani, Alka; Ray, Pallab

    2016-08-01

    Bacterial biofilms are implicated in a wide range of implant-based and chronic infections. These infections are often associated with adverse therapeutic outcomes, owing to the decreased antibiotic susceptibility of biofilms compared with their planktonic counterparts. This altered biofilm susceptibility has been attributed to multiple factors, including a reduced antibiotic penetration. Although several studies have addressed the role of penetration barrier in biofilm-associated drug resistance, it remains inconclusive. This study was done to elucidate antibiotic penetration through biofilms formed by Staphylococcus aureus, S. epidermidis, Escherichia coli and Klebsiella pneumoniae, using an agar disk diffusion assay. Penetration capacity of six antimicrobial drugs from different classes (β-lactams, aminoglycosides, tetracyclines, phenicols, fluoroquinolones and glycopeptides) through biofilms formed by standard strains and clinical isolates from catheter-related bloodstream infections (CRBSI) was elucidated by measuring their growth-inhibition zones in lawn cultures on Mueller-Hinton agar, following diffusion of an antibiotic from an overlying disk through their biofilm to the agar medium. Penetration of only select antimicrobials (vancomycin and chloramphenicol) was hindered through biofilms. There was considerable variation in biofilm-permeating capacity depending upon the genus, strain/CRBSI isolate and antibiotic tested. Furthermore, antibiotics failed to kill the biofilm cells independent of penetration, indicating that other factors contributed substantially to biofilm resistance. PMID:27402781

  16. Bioconjugation of Serum Albumin to a Maleimide-appended Porphyrin/Cyclodextrin Supramolecular Complex as an Artificial Oxygen Carrier in the Bloodstream.

    Science.gov (United States)

    Kitagishi, Hiroaki; Kawasaki, Hiroki; Kano, Koji

    2015-08-01

    HemoCD is an inclusion complex of per-O-methylated β-cyclodextrin dimer and an iron(II) porphyrin, which forms a stable O2 complex in water. Therefore, hemoCD has the potential for use as a synthetic O2 carrier in mammalian blood. In this study, a hemoCD derivative having a maleimide group (Mal-hemoCD) was conjugated to a Cys residue of serum albumin via a Michael addition reaction in order to increase the circulation time of the O2 carrier. The O2 -binding affinities (P1/2 [Torr]) and half-lives (t1/2 [h]) of the O2 adducts at pH 7.4 and 25 °C were determined to be 9 Torr and 23 h for Mal-hemoCD, and 10 Torr and 14 h for albumin-conjugated hemoCD (Alb-hemoCD). Our pharmacokinetic study revealed that renal excretion of Alb-hemoCD was effectively suppressed and that half of injected Alb-hemoCD remained in blood at 3 h after injection. It is noteworthy that Mal-hemoCD also had a long circulation time because of the bioconjugation reaction that occurred during circulation in the bloodstream. PMID:26053595

  17. A Modified Johnson-Cook Model for Sheet Metal Forming at Elevated Temperatures and Its Application for Cooled Stress-Strain Curve and Spring-Back Prediction

    International Nuclear Information System (INIS)

    In this study, a modified Johnson-Cook (J-C) model and an innovated method to determine (J-C) material parameters are proposed to predict more correctly stress-strain curve for tensile tests in elevated temperatures. A MATLAB tool is used to determine material parameters by fitting a curve to follow Ludwick's hardening law at various elevated temperatures. Those hardening law parameters are then utilized to determine modified (J-C) model material parameters. The modified (J-C) model shows the better prediction compared to the conventional one. As the first verification, an FEM tensile test simulation based on the isotropic hardening model for boron sheet steel at elevated temperatures was carried out via a user-material subroutine, using an explicit finite element code, and compared with the measurements. The temperature decrease of all elements due to the air cooling process was then calculated when considering the modified (J-C) model and coded to VUMAT subroutine for tensile test simulation of cooling process. The modified (J-C) model showed the good agreement between the simulation results and the corresponding experiments. The second investigation was applied for V-bending spring-back prediction of magnesium alloy sheets at elevated temperatures. Here, the combination of proposed J-C model with modified hardening law considering the unusual plastic behaviour for magnesium alloy sheet was adopted for FEM simulation of V-bending spring-back prediction and shown the good comparability with corresponding experiments.

  18. A Modified Johnson-Cook Model for Sheet Metal Forming at Elevated Temperatures and Its Application for Cooled Stress-Strain Curve and Spring-Back Prediction

    Science.gov (United States)

    Duc-Toan, Nguyen; Tien-Long, Banh; Young-Suk, Kim; Dong-Won, Jung

    2011-08-01

    In this study, a modified Johnson-Cook (J-C) model and an innovated method to determine (J-C) material parameters are proposed to predict more correctly stress-strain curve for tensile tests in elevated temperatures. A MATLAB tool is used to determine material parameters by fitting a curve to follow Ludwick's hardening law at various elevated temperatures. Those hardening law parameters are then utilized to determine modified (J-C) model material parameters. The modified (J-C) model shows the better prediction compared to the conventional one. As the first verification, an FEM tensile test simulation based on the isotropic hardening model for boron sheet steel at elevated temperatures was carried out via a user-material subroutine, using an explicit finite element code, and compared with the measurements. The temperature decrease of all elements due to the air cooling process was then calculated when considering the modified (J-C) model and coded to VUMAT subroutine for tensile test simulation of cooling process. The modified (J-C) model showed the good agreement between the simulation results and the corresponding experiments. The second investigation was applied for V-bending spring-back prediction of magnesium alloy sheets at elevated temperatures. Here, the combination of proposed J-C model with modified hardening law considering the unusual plastic behaviour for magnesium alloy sheet was adopted for FEM simulation of V-bending spring-back prediction and shown the good comparability with corresponding experiments.

  19. DNA microarray analysis of Staphylococcus aureus causing bloodstream infection: bacterial genes associated with mortality?

    Science.gov (United States)

    Blomfeldt, A; Aamot, H V; Eskesen, A N; Monecke, S; White, R A; Leegaard, T M; Bjørnholt, J V

    2016-08-01

    Providing evidence for microbial genetic determinants' impact on outcome in Staphylococcus aureus bloodstream infections (SABSI) is challenging due to the complex and dynamic microbe-host interaction. Our recent population-based prospective study reported an association between the S. aureus clonal complex (CC) 30 genotype and mortality in SABSI patients. This follow-up investigation aimed to examine the genetic profiles of the SABSI isolates and test the hypothesis that specific genetic characteristics in S. aureus are associated with mortality. SABSI isolates (n = 305) and S. aureus CC30 isolates from asymptomatic nasal carriers (n = 38) were characterised by DNA microarray analysis and spa typing. Fisher's exact test, least absolute shrinkage and selection operator (LASSO) and elastic net regressions were performed to discern within four groups defined by patient outcome and characteristics. No specific S. aureus genetic determinants were found to be associated with mortality in SABSI patients. By applying LASSO and elastic net regressions, we found evidence suggesting that agrIII and cna were positively and setC (=selX) and seh were negatively associated with S. aureus CC30 versus non-CC30 isolates. The genes chp and sak, encoding immune evasion molecules, were found in higher frequencies in CC30 SABSI isolates compared to CC30 carrier isolates, indicating a higher virulence potential. In conclusion, no specific S. aureus genes were found to be associated with mortality by DNA microarray analysis and state-of-the-art statistical analyses. The next natural step is to test the hypothesis in larger samples with higher resolution methods, like whole genome sequencing. PMID:27177754

  20. Clinical significance of coagulase-negative staphylococci isolates from nosocomial bloodstream infections.

    Science.gov (United States)

    Morad Asaad, Ahmed; Ansar Qureshi, Mohamed; Mujeeb Hasan, Syed

    2016-05-01

    Background Identification of coagulase-negative staphylococci (CoNS) as nosocomial pathogens or contaminants is significant for microbiologists and clinicians. This study aimed to determine the frequency of isolation and antimicrobial resistance patterns of CoNS isolates from nosocomial bloodstream infections (BSIs) and to identify risk factors associated with true bacteremia caused by these emerging pathogens in a Saudi tertiary care hospital. Methods All CoNS-positive cultures from inpatients were identified using the standard methods during a 10-month period. Antimicrobial susceptibility testing was done using the reference broth microdilution method. Results A total of 208 isolates were identified; of these 75 (32.2%) were considered infection associated, and 133 (67.8%) were considered contamination. S. epidermidis accounted for 34.7% of bacteremia cases, followed by S. hominis (21.3%), S. haemolyticus (16%), and S. saprophyticus (12%). Central venous catheters (p ≤ 0.0001), prior antibiotic therapy (p ≤ 0.0001), the occurrence of more than one positive blood culture (p ≤ 0.0001), and intensive care unit (ICU) admission (p = 0.007) were all independently associated with CoNS bacteremia. Overall, all isolates were highly resistant to penicillin (94.7%), oxacillin (90.7%), and erythromycin (85.3%). The rates of susceptibility to vancomycin, daptomycin, and teicoplanin were 98.7%, 98.7%, and 93.3%, respectively. Conclusions Our results further highlight that accurate identification and susceptibility testing of CoNS isolates from nosocomial BSIs are crucial to minimize excessive antibiotic use and unnecessary catheter removal. In addition, daptomycin may be an efficient alternative therapeutic option for CoNS resistant to oxacillin and other commonly used antibiotics. PMID:26666168

  1. Hospital-wide multidisciplinary, multimodal intervention programme to reduce central venous catheter-associated bloodstream infection.

    Science.gov (United States)

    Zingg, Walter; Cartier, Vanessa; Inan, Cigdem; Touveneau, Sylvie; Theriault, Michel; Gayet-Ageron, Angèle; Clergue, François; Pittet, Didier; Walder, Bernhard

    2014-01-01

    Central line-associated bloodstream infection (CLABSI) is the major complication of central venous catheters (CVC). The aim of the study was to test the effectiveness of a hospital-wide strategy on CLABSI reduction. Between 2008 and 2011, all CVCs were observed individually and hospital-wide at a large university-affiliated, tertiary care hospital. CVC insertion training started from the 3rd quarter and a total of 146 physicians employed or newly entering the hospital were trained in simulator workshops. CVC care started from quarter 7 and a total of 1274 nurses were trained by their supervisors using a web-based, modular, e-learning programme. The study included 3952 patients with 6353 CVCs accumulating 61,366 catheter-days. Hospital-wide, 106 patients had 114 CLABSIs with a cumulative incidence of 1.79 infections per 100 catheters. We observed a significant quarterly reduction of the incidence density (incidence rate ratios [95% confidence interval]: 0.92 [0.88-0.96]; P<0.001) after adjusting for multiple confounders. The incidence densities (n/1000 catheter-days) in the first and last study year were 2.3/1000 and 0.7/1000 hospital-wide, 1.7/1000 and 0.4/1000 in the intensive care units, and 2.7/1000 and 0.9/1000 in non-intensive care settings, respectively. Median time-to-infection was 15 days (Interquartile range, 8-22). Our findings suggest that clinically relevant reduction of hospital-wide CLABSI was reached with a comprehensive, multidisciplinary and multimodal quality improvement programme including aspects of behavioural change and key principles of good implementation practice. This is one of the first multimodal, multidisciplinary, hospital-wide training strategies successfully reducing CLABSI. PMID:24714418

  2. Three Epidemics of Invasive Multidrug-Resistant Salmonella Bloodstream Infection in Blantyre, Malawi, 1998–2014

    Science.gov (United States)

    Feasey, Nicholas A.; Masesa, Clemens; Jassi, Chikondi; Faragher, E. Brian; Mallewa, Jane; Mallewa, Macpherson; MacLennan, Calman A.; Msefula, Chisomo; Heyderman, Robert S.; Gordon, Melita A.

    2015-01-01

    Background. The Malawi Liverpool Wellcome Trust Clinical Research Programme (MLW) has routinely collected specimens for blood culture from febrile patients, and cerebrospinal fluid from patients with suspected meningitis, presenting to Queen Elizabeth Central Hospital (QECH), Blantyre, Malawi, since 1998. Methods. We present bloodstream infection (BSI) and meningitis surveillance data from 1998 to 2014. Automated blood culture, manual speciation, serotyping, and antimicrobial susceptibility testing were performed at MLW. Population data for minimum-incidence estimates in urban Blantyre were drawn from published estimates. Results. Between 1998 and 2014, 167 028 blood cultures were taken from adult and pediatric medical patients presenting to QECH; Salmonella Typhi was isolated on 2054 occasions (1.2%) and nontyphoidal Salmonella (NTS) serovars were isolated 10 139 times (6.1%), of which 8017 (79.1%) were Salmonella Typhimurium and 1608 (15.8%) were Salmonella Enteritidis. There were 392 cases of NTS meningitis and 9 cases of Salmonella Typhi meningitis. There have been 3 epidemics of Salmonella BSI in Blantyre; Salmonella Enteritidis from 1999 to 2002, Salmonella Typhimurium from 2002 to 2008, and Salmonella Typhi, which began in 2011 and was ongoing in 2014. Multidrug resistance has emerged in all 3 serovars and is seen in the overwhelming majority of isolates, while resistance to third-generation cephalosporins and fluoroquinolones is currently uncommon but has been identified. Conclusions. Invasive Salmonella disease in Malawi is dynamic and not clearly attributable to a single risk factor, although all 3 epidemics were associated with multidrug resistance. To inform nonvaccine and vaccine interventions, reservoirs of disease and modes of transmission require further investigation. PMID:26449953

  3. Combination Regimens for Treatment of Carbapenem-Resistant Klebsiella pneumoniae Bloodstream Infections.

    Science.gov (United States)

    Gomez-Simmonds, A; Nelson, B; Eiras, D P; Loo, A; Jenkins, S G; Whittier, S; Calfee, D P; Satlin, M J; Kubin, C J; Furuya, E Y

    2016-06-01

    Previous studies reported decreased mortality in patients with carbapenemase-producing Klebsiella pneumoniae bloodstream infections (BSIs) treated with combination therapy but included carbapenem-susceptible and -intermediate isolates, as per revised CLSI breakpoints. Here, we assessed outcomes in patients with BSIs caused by phenotypically carbapenem-resistant K. pneumoniae (CRKP) according to the number of in vitro active agents received and whether an extended-spectrum beta-lactam (BL) antibiotic, including meropenem, or an extended-spectrum cephalosporin was administered. We retrospectively reviewed CRKP BSIs at two New York City hospitals from 2006 to 2013, where all isolates had meropenem or imipenem MICs of ≥4 μg/ml. Univariate and multivariable models were created to identify factors associated with mortality. Of 141 CRKP BSI episodes, 23% were treated with a single active agent (SAA), 26% were treated with an SAA plus BL, 28% were treated with multiple active agents (MAA), and 23% were treated with MAA plus BL. Ninety percent of isolates had meropenem MICs of ≥16 μg/ml. Thirty-day mortality was 33% overall and did not significantly differ across the four treatment groups in a multivariable model (P = 0.4); mortality was significantly associated with a Pitt bacteremia score of ≥4 (odds ratio [OR], 7.7; 95% confidence interval [CI], 3.2 to 18.1; P = 0.1), and immunosuppression was protective (OR, 0.4; 95% CI, 0.2 to 1.0; P = 0.04). Individual treatment characteristics were also not significantly associated with outcome, including use of SAAs versus MAA (26% versus 38%, P = 0.1) or BL versus no BL (26% versus 39%, P = 0.1). In summary, in patients with CRKP BSIs caused by isolates with high carbapenem MICs, the role of combination therapy remains unclear, highlighting the need for prospective studies to identify optimal treatment regimens. PMID:27044555

  4. Bloodstream infection following 217 consecutive systemic-enteric drained pancreas transplants

    Directory of Open Access Journals (Sweden)

    Mark Walter

    2006-08-01

    Full Text Available Abstract Background Combined kidney pancreas transplantation (PTx evolved as excellent treatment for diabetic nephropathy. Infections remain common and serious complications. Methods 217 consecutive enteric drained PTxs performed from 1997 to 2004 were retrospectively analyzed with regard to bloodstream infection. Immunosuppression consisted of antithymocyteglobuline induction, tacrolimus, mycophenolic acid and steroids for the majority of cases. Standard perioperative antimicrobial prophylaxis consisted of pipercillin/tazobactam in combination with ciprofloxacin and fluconazole. Results One year patient, pancreas and kidney graft survival were 96.4%, 88.5% and 94.8%, surgical complication rate was 35%, rejection rate 30% and rate of infection 59%. In total 46 sepsis episodes were diagnosed in 35 patients (16% with a median onset on day 12 (range 1–45 post transplant. Sepsis source was intraabdominal infection (IAI (n = 21, a contaminated central venous line (n = 10, wound infection (n = 5, urinary tract infection (n = 2 and graft transmitted (n = 2. Nine patients (4% experienced multiple episodes of sepsis. Overall 65 pathogens (IAI sepsis 39, line sepsis 15, others 11 were isolated from blood. Gram positive cocci accounted for 50 isolates (77%: Coagulase negative staphylococci (n = 28, i.e. 43% (nine multi-resistant, Staphylococcus aureus (n = 11, i.e. 17% (four multi-resistant, enterococci (n = 9, i.e. 14% (one E. faecium. Gram negative rods were cultured in twelve cases (18%. Patients with blood borne infection had a two year pancreas graft survival of 76.5% versus 89.4% for those without sepsis (p = 0.036, patient survival was not affected. Conclusion Sepsis remains a serious complication after PTx with significantly reduced pancreas graft, but not patient survival. The most common source is IAI.

  5. Decolorization characteristics of a newly isolated salt-tolerant Bacillus sp. strain and its application for azo dye-containing wastewater in immobilized form.

    Science.gov (United States)

    Yu, Lei; Zhang, Xiao-Yu; Tang, Qing-Wen; Li, Jia; Xie, Tian; Liu, Chang; Cao, Ming-Yue; Zhang, Rui-Chang; Wang, Shi; Hu, Jin-Mei; Qiao, Wei-Chuan; Li, Wen-Wei; Ruan, Hong-Hua

    2015-11-01

    Strain CICC 23870 capable of decolorization of various azo dyes under high saline conditions was isolated from saline-alkali soil. The oxygen-insensitive azoreductase in crude extracts exhibited a wide substrate adaptively in the presence of NADH as a cofactor. The decolorization process by free cells followed first-order kinetics, with a high Methyl Orange (MO) tolerance concentration up to 100 mg l(-1) estimated by Haldane model. The average decolorization rate of free cell system was 26.30 mg g(-1) h(-1) at initial MO concentration of 32.7 mg l(-1). However, the values for the systems of immobilized cells (4 mm) in alginate, alginate and nano-TiO2, and alginate and powered activated carbon (PAC) were 6.83, 4.64, and 11.34 mg g(-1) h(-1), respectively. The effective diffusion factors in the tree different matrices were calculated by diffusion-based mathematic model. The diffusion step controls the overall decolorization rate, and the effective diffusion coefficients varied with internal structure of the bead matrices. The diffusion coefficients were increased from 4.98 × 10(-9) to 2.25 × 10(-8) cm(2) s(-1) when PAC was added, but decreased to 6.62 × 10(-10) cm(2) s(-1) when nano-TiO2 was added. The immobilized matrices could be reused for at least three cycles but with a decreased decolorization rate, possibly due to the breakage of beads at the end of each cycle, which led to the loss of immobilized bacteria. PMID:26175104

  6. Planar electron-tunneling Si/Si0.7Ge0.3 triple-barrier resonant tunneling diode formed on undoped strain-relaxed buffer with flat surface

    Science.gov (United States)

    Okubo, Takafumi; Tsukamoto, Takahiro; Suda, Yoshiyuki

    2014-03-01

    We demonstrated a planar electron-tunneling Si/Si0.7Ge0.3 triple-barrier (TB) resonant tunneling diode (RTD) formed via a channel layer on an undoped strain-relaxed quadruple-Si1-xGex-layer (QL) buffer. Compared with a conventional vertical Si/Si0.7Ge0.3 TB RTD formed on a heavily doped QL buffer, the dislocation density is low, the surface is flat, and the resonance current density is much larger. These observations, together with analyses of current-voltage (I-V) curve fitting to the physics-based analytical expression, suggest that the enhanced I-V characteristics in the planar RTD are related to decreases in the number of crystalline defect states and the structural and potential fluctuations.

  7. Bloodstream infection caused by extensively drug-resistant Acinetobacter baumannii in cancer patients: high mortality associated with delayed treatment rather than with the degree of neutropenia.

    Science.gov (United States)

    Freire, M P; de Oliveira Garcia, D; Garcia, C P; Campagnari Bueno, M F; Camargo, C H; Kono Magri, A S G; Francisco, G R; Reghini, R; Vieira, M F; Ibrahim, K Y; Rossi, F; Hajjar, L; Levin, A S; Hoff, P M; Pierrotti, L C; Abdala, E

    2016-04-01

    This study aimed to describe severe infections with extensively drug-resistant Acinetobacter baumannii-calcoaceticus complex (XDR-ABC), as well as to investigate risk factors for mortality, in cancer patients. It was a retrospective study including all patients diagnosed with XDR-ABC bacteraemia during hospitalization in the intensive care unit of a cancer hospital between July 2009 and July 2013. Surveillance cultures were collected weekly during the study period, and clonality was analysed using pulsed field gel electrophoresis (PFGE). We analysed underlying diseases, oncology therapy, neutrophil counts, infection site and management of infection, in terms of their correlation with 30-day mortality. During the study period, 92 patients with XDR-ABC bacteraemia were identified, of whom 35 (38.0%) were patients with haematological malignancy. We identified XDR-ABC strains with four different profile patterns, 91.3% of patients harbouring the predominant PFGE type. Of the 92 patients with XDR-ABC bacteraemia, 66 (71.7%) had central line-associated bloodstream infections; infection occurred during neutropenia in 22 (23.9%); and 58 (63.0%) died before receiving the appropriate therapy. All patients were treated with polymyxin, which was used in combination therapy in 30 of them (32.4%). The 30-day mortality rate was 83.7%. Multivariate analysis revealed that septic shock at diagnosis of XDR-ABC infection was a risk factor for 30-day mortality; protective factors were receiving appropriate therapy and invasive device removal within the first 48 h. Among cancer patients, ineffective management of such infection increases the risk of death, more so than do features such as neutropenia and infection at the tumour site. PMID:26711434

  8. Pseudomonas putida KT2440 Strain Metabolizes Glucose through a Cycle Formed by Enzymes of the Entner-Doudoroff, Embden-Meyerhof-Parnas, and Pentose Phosphate Pathways.

    Science.gov (United States)

    Nikel, Pablo I; Chavarría, Max; Fuhrer, Tobias; Sauer, Uwe; de Lorenzo, Víctor

    2015-10-23

    The soil bacterium Pseudomonas putida KT2440 lacks a functional Embden-Meyerhof-Parnas (EMP) pathway, and glycolysis is known to proceed almost exclusively through the Entner-Doudoroff (ED) route. To investigate the raison d'être of this metabolic arrangement, the distribution of periplasmic and cytoplasmic carbon fluxes was studied in glucose cultures of this bacterium by using (13)C-labeled substrates, combined with quantitative physiology experiments, metabolite quantification, and in vitro enzymatic assays under both saturating and non-saturating, quasi in vivo conditions. Metabolic flux analysis demonstrated that 90% of the consumed sugar was converted into gluconate, entering central carbon metabolism as 6-phosphogluconate and further channeled into the ED pathway. Remarkably, about 10% of the triose phosphates were found to be recycled back to form hexose phosphates. This set of reactions merges activities belonging to the ED, the EMP (operating in a gluconeogenic fashion), and the pentose phosphate pathways to form an unforeseen metabolic architecture (EDEMP cycle). Determination of the NADPH balance revealed that the default metabolic state of P. putida KT2440 is characterized by a slight catabolic overproduction of reducing power. Cells growing on glucose thus run a biochemical cycle that favors NADPH formation. Because NADPH is required not only for anabolic functions but also for counteracting different types of environmental stress, such a cyclic operation may contribute to the physiological heftiness of this bacterium in its natural habitats. PMID:26350459

  9. Epidemiology of community-onset bloodstream infections in Bouaké, central Côte d'Ivoire.

    Science.gov (United States)

    Akoua-Koffi, C; Tia, H; Plo, J K; Monemo, P; Cissé, A; Yao, C; Yenan, P J; Touré, F S; Ilupeju, V; Bogoch, I I; Utzinger, J; Herrmann, M; Becker, S L

    2015-09-01

    Bacterial bloodstream infections (BSI) account for considerable morbidity worldwide, but epidemiological data from resource-constrained tropical settings are scarce. We analysed 293 blood cultures from patients presenting to a regional referral hospital in Bouaké, central Côte d'Ivoire, to determine the aetiology of community-onset BSI. The prevalence of bacteraemia was 22.5%, with children being most commonly affected. Enterobacteriaceae (predominantly Klebsiella pneumoniae and Salmonella enterica) accounted for 94% of BSI. Staphylococcus aureus was the only relevant Gram-positive pathogen. Clinical signs and symptoms were not significantly associated with blood culture positivity after controlling for malaria. PMID:26442153

  10. Epidemiology of community-onset bloodstream infections in Bouaké, central Côte d’Ivoire

    Directory of Open Access Journals (Sweden)

    C. Akoua-Koffi

    2015-09-01

    Full Text Available Bacterial bloodstream infections (BSI account for considerable morbidity worldwide, but epidemiological data from resource-constrained tropical settings are scarce. We analysed 293 blood cultures from patients presenting to a regional referral hospital in Bouaké, central Côte d’Ivoire, to determine the aetiology of community-onset BSI. The prevalence of bacteraemia was 22.5%, with children being most commonly affected. Enterobacteriaceae (predominantly Klebsiella pneumoniae and Salmonella enterica accounted for 94% of BSI. Staphylococcus aureus was the only relevant Gram-positive pathogen. Clinical signs and symptoms were not significantly associated with blood culture positivity after controlling for malaria.

  11. Epidemiology of community-onset bloodstream infections in Bouaké, central Côte d’Ivoire

    Science.gov (United States)

    Akoua-Koffi, C.; Tia, H.; Plo, J.K.; Monemo, P.; Cissé, A.; Yao, C.; Yenan, P.J.; Touré, F.S.; Ilupeju, V.; Bogoch, I.I.; Utzinger, J.; Herrmann, M.; Becker, S.L.

    2015-01-01

    Bacterial bloodstream infections (BSI) account for considerable morbidity worldwide, but epidemiological data from resource-constrained tropical settings are scarce. We analysed 293 blood cultures from patients presenting to a regional referral hospital in Bouaké, central Côte d’Ivoire, to determine the aetiology of community-onset BSI. The prevalence of bacteraemia was 22.5%, with children being most commonly affected. Enterobacteriaceae (predominantly Klebsiella pneumoniae and Salmonella enterica) accounted for 94% of BSI. Staphylococcus aureus was the only relevant Gram-positive pathogen. Clinical signs and symptoms were not significantly associated with blood culture positivity after controlling for malaria. PMID:26442153

  12. Wpływ szczepów bakterii wyizolowanych z hydroponicznej uprawy sałaty (Lactuca sativa L. na wzrost siewek sałaty, rosnących w obecnosci rożnych form pożywienia azotowego [Influence of bacterial strains isolated from hydroponic cultures of lettuce (Lactuca sativa L. on the growth of lettuce seedlings growing in the presence of various forms of nitrogen nutrition

    Directory of Open Access Journals (Sweden)

    Z. Kobierzyńska-Gołąb

    2015-06-01

    Full Text Available 320 bacterial strains isolated from the surface of cultivated plants, as well as from other parts of hydroponic cultures showed stimulating (49 bacterial strains or inhibitory (9 bacterial strains properties in respect to the investigated plant. The following bacteria were isolated: Pseudomonas, Flavobacterium, Agrobacterium, Achromobacter and Chromobacterium. The effects of active bacterial strains on the growth of seedlings were investigated in dependence on the kind of inorganic form of nitrogen present in the nutrient solutions. The same bacterial strains exerted a stimulating effect on seedlings growing on nitrates, weaker stimulation was observed in cultures with ammonium nitrate; the growth of lettuce seedlings on nutrient solution with ammonium only, was, as a rule, inhibited by the bacteria.

  13. Molecular Identification and Echinocandin Susceptibility of Candida parapsilosis Complex Bloodstream Isolates in Italy, 2007-2014.

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    Grazia Lovero

    Full Text Available The Candida parapsilosis group encompasses three species: C. parapsilosis, C. orthopsilosis, and C. metapsilosis. Here, we describe the incidence and echinocandin susceptibility profile of bloodstream isolates of these three species collected from patients admitted to an Italian university hospital from 2007 to 2014. Molecular identification of cryptic species of the C. parapsilosis complex was performed using polymerase chain reaction amplification of the gene encoding secondary alcohol dehydrogenase, followed by digestion with the restriction enzyme BanI. Minimum inhibitory concentrations were determined using the broth microdilution method according to European Committee for Antimicrobial Susceptibility Testing (EUCAST EDef 7.2 and Clinical Laboratory Standards Institute (CLSI M27-A3 guidelines, and the results were compared with those obtained using the E-test and Sensititre methods. Of the 163 C. parapsilosis complex isolates, 136 (83.4% were identified as C. parapsilosis, and 27 (16.6% as C. orthopsilosis. The species-specific incidences were 2.9/10,000 admissions for C. parapsilosis and 0.6/10,000 admissions for C. orthopsilosis. No resistance to echinocandins was detected with any of the methods. The percent essential agreement (EA between the EUCAST and E-test/Sensititre methods for anidulafungin, caspofungin, and micafungin susceptibility was, respectively, as follows: C. parapsilosis, 95.6/97.8, 98.5/88.2, and 93.4/96.3; C. orthopsilosis, 92.6/92.6, 96.3/77.8, and 63.0/66.7. The EA between the CLSI and E-test/Sensititre methods was, respectively, as follows: C. parapsilosis, 99.3/100, 98.5/89.0, and 96.3/98.5; C. orthopsilosis, 96.3/92.6, 100/81.5, and 92.6/88.9. Only minor discrepancies, ranging from 16.9% (C. parapsilosis to 11.1% (C. orthopsilosis, were observed between the CLSI and E-test/Sensititre methods. In conclusion, this epidemiologic study shows a typical C. parapsilosis complex species distribution, no echinocandin

  14. Comparison of the systemic inflammatory response syndrome between monomicrobial and polymicrobial Pseudomonas aeruginosa nosocomial bloodstream infections

    Directory of Open Access Journals (Sweden)

    Wenzel Richard P

    2005-10-01

    Full Text Available Abstract Background Some studies of nosocomial bloodstream infection (nBSI have demonstrated a higher mortality for polymicrobial bacteremia when compared to monomicrobial nBSI. The purpose of this study was to compare differences in systemic inflammatory response and mortality between monomicrobial and polymicrobial nBSI with Pseudomonas aeruginosa. Methods We performed a historical cohort study on 98 adults with P. aeruginosa (Pa nBSI. SIRS scores were determined 2 days prior to the first positive blood culture through 14 days afterwards. Monomicrobial (n = 77 and polymicrobial BSIs (n = 21 were compared. Results 78.6% of BSIs were caused by monomicrobial P. aeruginosa infection (MPa and 21.4% by polymicrobial P. aeruginosa infection (PPa. Median APACHE II score on the day of BSI was 22 for MPa and 23 for PPa BSIs. Septic shock occurred in 33.3% of PPa and in 39.0% of MPa (p = 0.64. Progression to septic shock was associated with death more frequently in PPa (OR 38.5, CI95 2.9–508.5 than MPa (OR 4.5, CI95 1.7–12.1. Maximal SIR (severe sepsis, septic shock or death was seen on day 0 for PPa BSI vs. day 1 for MPa. No significant difference was noted in the incidence of organ failure, 7-day or overall mortality between the two groups. Univariate analysis revealed that APACHE II score ≥20 at BSI onset, Charlson weighted comorbidity index ≥3, burn injury and respiratory, cardiovascular, renal and hematologic failure were associated with death, while age, malignant disease, diabetes mellitus, hepatic failure, gastrointestinal complications, inappropriate antimicrobial therapy, infection with imipenem resistant P. aeruginosa and polymicrobial nBSI were not. Multivariate analysis revealed that hematologic failure (p Conclusion In this historical cohort study of nBSI with P. aeruginosa, the incidence of septic shock and organ failure was high in both groups. Additionally, patients with PPa BSI were not more acutely ill, as judged by APACHE II

  15. Bloodstream and endovascular infections due to Abiotrophia defectiva and Granulicatella species

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    Bille Jacques

    2006-01-01

    Full Text Available Abstract Background Abiotrophia and Granulicatella species, previously referred to as nutritionally variant streptococci (NVS, are significant causative agents of endocarditis and bacteraemia. In this study, we reviewed the clinical manifestations of infections due to A. defectiva and Granulicatella species that occurred at our institution between 1998 and 2004. Methods The analysis included all strains of NVS that were isolated from blood cultures or vascular graft specimens. All strains were identified by 16S rRNA sequence analysis. Patients' medical charts were reviewed for each case of infection. Results Eleven strains of NVS were isolated during the 6-year period. Identification of the strains by 16S rRNA showed 2 genogroups: Abiotrophia defectiva (3 and Granulicatella adiacens (6 or "para-adiacens" (2. The three A. defectiva strains were isolated from immunocompetent patients with endovascular infections, whereas 7 of 8 Granulicatella spp. strains were isolated from immunosuppressed patients, mainly febrile neutropenic patients. We report the first case of "G. para-adiacens" bacteraemia in the setting of febrile neutropenia. Conclusion We propose that Granulicatella spp. be considered as a possible agent of bacteraemia in neutropenic patients.

  16. Teaching Form as Form

    DEFF Research Database (Denmark)

    Keiding, Tina Bering

    2012-01-01

    understanding of form per se, or, to use an expression from this text, of form as form. This challenge can be reduced to one question: how can design teaching support students in achieving not only the ability to recognize and describe different form-related concepts in existing design (i.e. analytical and...

  17. Reconstitution of a surface transferrin binding complex in insect form Trypanosoma brucei.

    OpenAIRE

    Ligtenberg, M.J.; Bitter, W.; Kieft, R.; Steverding, D; Janssen, H.; Calafat, J.; Borst, P

    1994-01-01

    In the bloodstream of the mammalian host, Trypanosoma brucei takes up host transferrin by means of a high-affinity uptake system, presumably a transferrin receptor. Transferrin-binding activity is seen in the flagellar pocket and is absent in insect form trypanosomes. By transfection we have reconstituted a transferrin-binding complex in insect form trypanosomes. Formation of this complex requires the products of two genes that are part of a variant surface glycoprotein expression site, expre...

  18. Distribution of pathogens causing catheter-associated bloodstream infections in hemodialysis patients and analysis of risk factors%血液透析患者导管相关性血流感染病原菌分布与危险因素分析

    Institute of Scientific and Technical Information of China (English)

    杨春琴; 黄敏; 翁明祥

    2015-01-01

    目的:探讨血液透析患者导管相关性血流感染的病原菌分布及相关危险因素,为制定相应的干预措施提供参考依据。方法回顾性分析286例行中心静脉留置透析导管透析患者的临床资料,记录透析患者的年龄、性别、基础疾病、置管种类及部位、导管留置时间、病原菌培养结果。结果286例留置中心静脉透析导管患者,发生CRBSI 28例,发生率为9.79%;共分离出病原菌28株,其中革兰阳性菌20株占71.44%,以表皮葡萄球菌、金黄色葡萄球菌为主,革兰阴性菌8株占28.56%,以铜绿假单胞菌、大肠埃希菌、褪色沙雷菌为主;年龄>60岁、原发病为糖尿病肾病、导管留置时间>2周、行股静脉置管与CRBSI的发生具有相关性(P<0.05)。结论 CRB‐SI感染病原菌以革兰阳性菌为主,高龄、糖尿病、导管留置时间长、股静脉置管为导管相关性血流感染的危险因素。%OBJECTIVE To explore the distribution of pathogens causing catheter‐associated bloodstream infections in the hemodialysis patients and analyze the related risk factors so as to put forward targeted interventions . METHODS The clinical data of 286 patients who underwent indwelling central venous catheter hemodialysis were retrospectively analyzed;the age ,genders ,underlying diseases ,types of indwelling catheter ,intubation sites , catheter indwelling time ,and result of cultures of pathogens were recorded and observed .RESULTS The catheter‐associated bloodstream infections occurred in 28 of 286 patients undergoing indwelling central venous catheter he‐modialysis ,with the incidence rate of 9 .79% .A total of 28 strains of pathogens have been isolated ,including 20 (71 .44% ) strains of gram‐positive bacteria and 8 (28 .56% ) strains of gram‐negative bacteria;the Staphylococcus epidermidis and Staphylococcus aureus were the predominant species of the gram‐positive bacteria

  19. Impact of a modified Broviac maintenance care bundle on bloodstream infections in paediatric cancer patients

    Directory of Open Access Journals (Sweden)

    Furtwängler, Rhoikos

    2015-11-01

    Full Text Available Background: During intensive chemotherapy, bloodstream infection (BSI represents an important complication in paediatric cancer patients. Most patients carry a long-term central venous access device (CVAD. Improved maintenance care of these vascular catheters may decrease the risk of BSI.Methods: Intervention study (adapted CVAD prevention protocol with two observation periods (P1: 09-2009 until 05-2011; P2: 09-2011 until 05-2013; prospective surveillance of all laboratory confirmed BSIs. In P2, ready to use sterile NaCl 0.9% syringes were used for CVAD flushing and octenidine/isopropanol for the disinfection of catheter hubs and 3-way stopcocks. Results: During P1, 84 patients were included versus 81 patients during P2. There were no significant differences between the two patient populations in terms of median age, gender, underlying malignancy or disease status (first illness or relapse. Nearly all CVADs were Broviac catheters. The median duration from implantation to removal of the CVAD was 192 days (Inter-quartile-range (IQR; 110–288 days in P1 and 191 days (IQR; 103–270 days in P2. 28 BSI were diagnosed in 22 patients in P1 (26% of all patients experienced at least one BSI and 15 BSI in 12 patients in P2 (15% of all patients. The corresponding results for incidence density (ID were 0.44 (CI95 0.29–0.62 for P1 vs. 0.34 (0.19–0.53 BSI per 100 inpatient days for P2 and for incidence rate (IR 7.76 (5.16–10.86 in P1 vs. 4.75 (2.66–7.43 BSI per 1,000 inpatient CVAD utilization days. In P1, 9 BSI were caused by CoNS vs. only 2 in P2 (IR 2.49; CI95 0.17–4.17 vs. 0.63; CI95 0.08–1.72. In P1 two BSI (7% lead to early removal of the device. During P2 one CVAD was prematurely removed due to a Broviac-related BSI (6.7%.Conclusion: The preventive protocol investigated in this study led to a reduction of BSI in paediatric cancer patients. This result was clinically relevant but – due to insufficient power in a single centre observation

  20. DNA microarray genotyping and virulence and antimicrobial resistance gene profiling of methicillin-resistant Staphylococcus aureus bloodstream isolates from renal patients.

    LENUS (Irish Health Repository)

    McNicholas, Sinead

    2012-02-01

    Thirty-six methicillin-resistant Staphylococcus aureus (MRSA) bloodstream isolates from renal patients were genetically characterized by DNA microarray analysis and spa typing. The isolates were highly clonal, belonging mainly to ST22-MRSA-IV. The immune evasion and enterotoxin gene clusters were found in 29\\/36 (80%) and 33\\/36 (92%) isolates, respectively.

  1. “What the Eyes Don’t See, the Heart Doesn’t Grieve Over”: Epidemiology and Risk Factors for Bloodstream Infections following Cardiac Catheterization

    OpenAIRE

    Dicks, Kristen V.; Staheli, Russell; Anderson, Deverick J.; Miller, Becky A.; Jones, W. Schuyler; Harrison, J. Kevin; Sexton, Daniel J.; Moehring, Rebekah W.; Chen, Luke F.

    2012-01-01

    No standard definition exists for surveillance and characterization of the epidemiology of bloodstream infections (BSIs) after cardiac catheterization (CC) procedures. We proposed a novel case definition and determined the epidemiology and risk factors of BSIs after CC procedure using this new definition.

  2. Detection of mcr-1 encoding plasmid-mediated colistin-resistant Escherichia coli isolates from human bloodstream infection and imported chicken meat, Denmark 2015

    DEFF Research Database (Denmark)

    Hasman, H.; Hammerum, A. M.; Hansen, F.;

    2015-01-01

    The plasmid-mediated colistin resistance gene, mcr-1, was detected in an Escherichia coli isolate from a Danish patient with bloodstream infection and in five E. coli isolates from imported chicken meat. One isolate from chicken meat belonged to the epidemic spreading sequence type ST131. In...

  3. DNA microarray genotyping and virulence and antimicrobial resistance gene profiling of methicillin-resistant Staphylococcus aureus bloodstream isolates from renal patients.

    LENUS (Irish Health Repository)

    McNicholas, Sinead

    2011-12-01

    Thirty-six methicillin-resistant Staphylococcus aureus (MRSA) bloodstream isolates from renal patients were genetically characterized by DNA microarray analysis and spa typing. The isolates were highly clonal, belonging mainly to ST22-MRSA-IV. The immune evasion and enterotoxin gene clusters were found in 29\\/36 (80%) and 33\\/36 (92%) isolates, respectively.

  4. Analysis of clinical distribution and drug resistance of bloodstream infections caused by Klebsiella pneumoniae%肺炎克雷伯菌血流感染的临床分布及耐药性分析

    Institute of Scientific and Technical Information of China (English)

    查翔远; 宋有良; 林建; 崔小玲; 潘晓龙; 倪世峰

    2015-01-01

    Objective To study the clinical distribution and antimicrobial resistance of bloodstream infections caused by Klebsiella pneumoniae .Methods Patients with bloodstream infection caused by Klebsiella pneumoniae in Tongling People's Hospital in Anhui province from January 2008 to December 2013 were retrospectively reviewed.Results A total of 71 cases were found with bloodstream infection caused by Klebsiella pneumoniae, the top three clinical distribution departments were infectious diseases department, ICU and oncology de-partment, and the top three complications were pulmonary infection, malignant tumor, biliary tract infection as well as diabetes mellitus. There were 24 strains of ESBLs-producing Klebsiella pneumoniae, accounting for 33.8%among 71 strains of Klebsiella pneumoniae isolated from the blood samples, in which 18 (52.9%) strains of ESBLs-producing Klebsiella pneumoniae among 34 hospital acquired infection cases and 6 ( 1 6 .2%) strains of ESBLs-producing Klebsiella pneumoniae among 3 7 community acquired infection cases;the positive rate of ESBLs-producing Klebsiella pneumoniae strains among hospital acquired infection cases was significantly higher than that of community acquired in-fection cases(χ2 =10.680, P=0.05).Among 71 strains of Klebsiella pneumoniae, no imipenem or meropenem-resistant isolate was found, and the resistance rates to amikacin, levofloxacin, ciprofIoxacin, cefoxitin, cefepime, cefoperazone/sulbactam and piperacillin/tazobactam were low(<20%) .The resistance rates of stains isolated from hospital acquired infection cases to piperaeillin, amoxicillin/clavulanate, cef-operazone/sulbactam, ampicillin/sulbactam, ticareillin/clavulanate, piperacillin/tazobactam, cefazolin, cefoperazone, cefuroxime, ceftazi-dime, ceftriaxone, cefotaxime and aztreonam were significantly higher than those of stains isolated from community acquired infection cases. The resistance rates of ESBLs-producing Klebsiella pneumoniae strains to 20 antimicrobial

  5. Effectiveness of a programme to reduce the burden of catheter-related bloodstream infections in a tertiary hospital.

    Science.gov (United States)

    Martínez-Morel, H R; Sanchez-Payá, J; García-Shimizu, P; Mendoza-García, J L; Tenza-Iglesias, I; Rodríguez-Díaz, J C; Merino-DE-Lucas, E; Nolasco, A

    2016-07-01

    The objective of this study was to assess the effectiveness of a catheter-related bloodstream infection (CR BSI) reduction programme and healthcare workers' compliance with recommendations. A 3-year surveillance programme of CR BSIs in all hospital settings was implemented. As part of the programme, there was a direct observation of insertion and maintenance of central venous catheters (CVCs) to determine performance. A total of 38 education courses were held over the study period and feedback reports with the results of surveillance and recommendations were delivered to healthcare workers every 6 months. A total of 6722 short-term CVCs were inserted in 4982 patients for 58 763 catheter-days. Improvements of compliance with hand hygiene was verified at the insertion (87·1-100%, P education programme clearly improved compliance with recommendations for CVC handling, and was effective in reducing the burden of CR BSIs. PMID:26758404

  6. Surveillance of Candida spp bloodstream infections: epidemiological trends and risk factors of death in two Mexican tertiary care hospitals.

    Directory of Open Access Journals (Sweden)

    Dora E Corzo-Leon

    Full Text Available INTRODUCTION: Larger populations at risk, broader use of antibiotics and longer hospital stays have impacted on the incidence of Candida sp. bloodstream infections (CBSI. OBJECTIVE: To determine clinical and epidemiologic characteristics of patients with CBSI in two tertiary care reference medical institutions in Mexico City. DESIGN: Prospective and observational laboratory-based surveillance study conducted from 07/2008 to 06/2010. METHODS: All patients with CBSI were included. Identification and antifungal susceptibility were performed using CLSI M27-A3 standard procedures. Frequencies, Mann-Whitney U test or T test were used as needed. Risk factors were determined with multivariable analysis and binary logistic regression analysis. RESULTS: CBSI represented 3.8% of nosocomial bloodstream infections. Cumulative incidence was 2.8 per 1000 discharges (incidence rate: 0.38 per 1000 patient-days. C. albicans was the predominant species (46%, followed by C. tropicalis (26%. C. glabrata was isolated from patients with diabetes (50%, and elderly patients. Sixty-four patients (86% received antifungals. Amphotericin-B deoxycholate (AmBD was the most commonly used agent (66%. Overall mortality rate reached 46%, and risk factors for death were APACHE II score ≥ 16 (OR = 6.94, CI95% = 2.34-20.58, p<0.0001, and liver disease (OR = 186.11, CI95% = 7.61-4550.20, p = 0.001. Full susceptibility to fluconazole, AmBD and echinocandins among C. albicans, C. tropicalis, and C. parapsilosis was observed. CONCLUSIONS: The cumulative incidence rate in these centers was higher than other reports from tertiary care hospitals from Latin America. Knowledge of local epidemiologic patterns permits the design of more specific strategies for prevention and preemptive therapy of CBSI.

  7. Characterization of Pneumococcal Genes Involved in Bloodstream Invasion in a Mouse Model.

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    Layla K Mahdi

    Full Text Available Streptococcus pneumoniae (the pneumococcus continues to account for significant morbidity and mortality worldwide, causing life-threatening diseases such as pneumonia, bacteremia and meningitis, as well as less serious infections such as sinusitis, conjunctivitis and otitis media. Current polysaccharide vaccines are strictly serotype-specific and also drive the emergence of non-vaccine serotype strains. In this study, we used microarray analysis to compare gene expression patterns of either serotype 4 or serotype 6A pneumococci in the nasopharynx and blood of mice, as a model to identify genes involved in invasion of blood in the context of occult bacteremia in humans. In this manner, we identified 26 genes that were significantly up-regulated in the nasopharynx and 36 genes that were significantly up-regulated in the blood that were common to both strains. Gene Ontology classification revealed that transporter and DNA binding (transcription factor activities constitute the significantly different molecular functional categories for genes up-regulated in the nasopharynx and blood. Targeted mutagenesis of selected genes from both niches and subsequent virulence and pathogenesis studies identified the manganese-dependent superoxide dismutase (SodA as most likely to be essential for colonization, and the cell wall-associated serine protease (PrtA as important for invasion of blood. This work extends our previous analyses and suggests that both PrtA and SodA warrant examination in future studies aimed at prevention and/or control of pneumococcal disease.

  8. Hydrogen production from microbial strains

    Science.gov (United States)

    Harwood, Caroline S; Rey, Federico E

    2012-09-18

    The present invention is directed to a method of screening microbe strains capable of generating hydrogen. This method involves inoculating one or more microbes in a sample containing cell culture medium to form an inoculated culture medium. The inoculated culture medium is then incubated under hydrogen producing conditions. Once incubating causes the inoculated culture medium to produce hydrogen, microbes in the culture medium are identified as candidate microbe strains capable of generating hydrogen. Methods of producing hydrogen using one or more of the microbial strains identified as well as the hydrogen producing strains themselves are also disclosed.

  9. Bloodstream Infection in Neutropenic Cancer Patients Related to Short-Term Nontunnelled Catheters Determined by Quantitative Blood Cultures, Differential Time to Positivity, and Molecular Epidemiological Typing with Pulsed-Field Gel Electrophoresis

    OpenAIRE

    Seifert, Harald; Cornely, Oliver; Seggewiss, Kerstin; Decker, Mathias; Stefanik, Danuta; Wisplinghoff, Hilmar; Fätkenheuer, Gerd

    2003-01-01

    To determine the rate of catheter-related bloodstream infection (CRBSI) among cases of primary bloodstream infection (BSI) in febrile neutropenic cancer patients with short-term nontunnelled catheters, quantitative paired blood cultures (Isolator) from the central venous catheter (CVC) and peripheral vein were obtained between November 1999 and January 2001. Bactec blood culture bottles were obtained to determine the differential time to positivity (DTP). CRBSI was defined as a quantitative b...

  10. Efficiency of vanilla, patchouli and ylang ylang essential oils stabilized by iron oxide@C14 nanostructures against bacterial adherence and biofilms formed by Staphylococcus aureus and Klebsiella pneumoniae clinical strains.

    Science.gov (United States)

    Bilcu, Maxim; Grumezescu, Alexandru Mihai; Oprea, Alexandra Elena; Popescu, Roxana Cristina; Mogoșanu, George Dan; Hristu, Radu; Stanciu, George A; Mihailescu, Dan Florin; Lazar, Veronica; Bezirtzoglou, Eugenia; Chifiriuc, Mariana Carmen

    2014-01-01

    Biofilms formed by bacterial cells are associated with drastically enhanced resistance against most antimicrobial agents, contributing to the persistence and chronicization of the microbial infections and to therapy failure. The purpose of this study was to combine the unique properties of magnetic nanoparticles with the antimicrobial activity of three essential oils to obtain novel nanobiosystems that could be used as coatings for catheter pieces with an improved resistance to Staphylococcus aureus and Klebsiella pneumoniae clinical strains adherence and biofilm development. The essential oils of ylang ylang, patchouli and vanilla were stabilized by the interaction with iron oxide@C14 nanoparticles to be further used as coating agents for medical surfaces. Iron oxide@C14 was prepared by co-precipitation of Fe+2 and Fe+3 and myristic acid (C14) in basic medium. Vanilla essential oil loaded nanoparticles pelliculised on the catheter samples surface strongly inhibited both the initial adherence of S. aureus cells (quantified at 24 h) and the development of the mature biofilm quantified at 48 h. Patchouli and ylang-ylang essential oils inhibited mostly the initial adherence phase of S. aureus biofilm development. In the case of K. pneumoniae, all tested nanosystems exhibited similar efficiency, being active mostly against the adherence K. pneumoniae cells to the tested catheter specimens. The new nanobiosystems based on vanilla, patchouli and ylang-ylang essential oils could be of a great interest for the biomedical field, opening new directions for the design of film-coated surfaces with anti-adherence and anti-biofilm properties. PMID:25375335

  11. Efficiency of Vanilla, Patchouli and Ylang Ylang Essential Oils Stabilized by Iron Oxide@C14 Nanostructures against Bacterial Adherence and Biofilms Formed by Staphylococcus aureus and Klebsiella pneumoniae Clinical Strains

    Directory of Open Access Journals (Sweden)

    Maxim Bilcu

    2014-11-01

    Full Text Available Biofilms formed by bacterial cells are associated with drastically enhanced resistance against most antimicrobial agents, contributing to the persistence and chronicization of the microbial infections and to therapy failure. The purpose of this study was to combine the unique properties of magnetic nanoparticles with the antimicrobial activity of three essential oils to obtain novel nanobiosystems that could be used as coatings for catheter pieces with an improved resistance to Staphylococcus aureus and Klebsiella pneumoniae clinical strains adherence and biofilm development. The essential oils of ylang ylang, patchouli and vanilla were stabilized by the interaction with iron oxide@C14 nanoparticles to be further used as coating agents for medical surfaces. Iron oxide@C14 was prepared by co-precipitation of Fe+2 and Fe+3 and myristic acid (C14 in basic medium. Vanilla essential oil loaded nanoparticles pelliculised on the catheter samples surface strongly inhibited both the initial adherence of S. aureus cells (quantified at 24 h and the development of the mature biofilm quantified at 48 h. Patchouli and ylang-ylang essential oils inhibited mostly the initial adherence phase of S. aureus biofilm development. In the case of K. pneumoniae, all tested nanosystems exhibited similar efficiency, being active mostly against the adherence K. pneumoniae cells to the tested catheter specimens. The new nanobiosystems based on vanilla, patchouli and ylang-ylang essential oils could be of a great interest for the biomedical field, opening new directions for the design of film-coated surfaces with anti-adherence and anti-biofilm properties.

  12. Healthcare Burden, Risk Factors, and Outcomes of Mucosal Barrier Injury Laboratory-Confirmed Bloodstream Infections after Stem Cell Transplantation.

    Science.gov (United States)

    Dandoy, Christopher E; Haslam, David; Lane, Adam; Jodele, Sonata; Demmel, Kathy; El-Bietar, Javier; Flesch, Laura; Myers, Kasiani C; Pate, Abigail; Rotz, Seth; Daniels, Paulina; Wallace, Gregory; Nelson, Adam; Waters, Heather; Connelly, Beverly; Davies, Stella M

    2016-09-01

    Mucosal barrier injury laboratory-confirmed bloodstream infections (MBI-LCBIs) lead to significant morbidity, mortality, and healthcare resource utilization in hematopoietic stem cell transplant (HSCT) patients. Determination of the healthcare burden of MBI-LCBIs and identification of patients at risk of MBI-LCBIs will allow researchers to identify strategies to reduce MBI-LCBI rates. The objective of our study was to describe the incidence, risk factors, timing, and outcomes of MBI-LCBIs in hematopoietic stem cell transplant patients. We performed a retrospective analysis of 374 patients who underwent HSCT at a large free-standing academic children's hospital to determine the incidence, risk factors, and outcomes of patients that developed a bloodstream infection (BSI) including MBI-LCBI, central line-associated BSI (CLABSI), or secondary BSI in the first year after HSCT. Outcome measures included nonrelapse mortality (NRM), central venous catheter removal within 7 days of positive culture, shock, admission to the pediatric intensive care unit (PICU) within 48 hours of positive culture, and death within 10 days of positive culture. One hundred seventy BSIs were diagnosed in 100 patients (27%): 80 (47%) MBI-LCBIs, 68 (40%) CLABSIs, and 22 (13%) secondary infections. MBI-LCBIs were diagnosed at a significantly higher rate in allogeneic HSCT patients (18% versus 7%, P = .007). Reduced-intensity conditioning (OR, 1.96; P = .015) and transplant-associated thrombotic microangiopathy (OR, 2.94; P = .0004) were associated with MBI-LCBI. Nearly 50% of all patients with a BSI developed septic shock, 10% died within 10 days of positive culture, and nearly 25% were transferred to the PICU. One-year NRM was significantly increased in patients with 1 (34%) and more than 1 (56%) BSIs in the first year post-HSCT compared with those who did not develop BSIs (14%) (P ≤ .0001). There was increased 1-year NRM in patients with at least 1 MBI-LCBI (OR, 1.94; P

  13. Antimicrobial co-resistance patterns of gram-negative bacilli isolated from bloodstream infections: a longitudinal epidemiological study from 2002–2011

    OpenAIRE

    Wong, Patrick HP; von Krosigk, Marcus; Roscoe, Diane L.; Lau, Tim TY; Yousefi, Masoud; William R Bowie

    2014-01-01

    Background Increasing multidrug resistance in gram-negative bacilli (GNB) infections poses a serious threat to public health. Few studies have analyzed co-resistance rates, defined as an antimicrobial susceptibility profile in a subset already resistant to one specific antibiotic. The epidemiologic and clinical utility of determining co-resistance rates are analyzed and discussed. Methods A 10-year retrospective study from 2002–2011 of bloodstream infections with GNB were analyzed from three ...

  14. Nationwide German Multicenter Study on Prevalence of Antibiotic Resistance in Staphylococcal Bloodstream Isolates and Comparative In Vitro Activities of Quinupristin-Dalfopristin

    OpenAIRE

    von Eiff, Christof; Reinert, Ralf René; Kresken, Michael; Brauers, Johannes; Hafner, Dieter; Peters, Georg

    2000-01-01

    Antibiotic-resistant gram-positive bacteria have become an increasing problem in the last two decades. In order to evaluate the prevalence of antibiotic resistance in staphylococcal bloodstream isolates in Germany, 2,042 staphylococci collected in 21 tertiary-care hospitals were investigated during a 3-year period (March 1996 to March 1999). Altogether, 1,448 S. aureus isolates and 594 coagulase-negative staphylococci (CoNS) that comprised 13 different species were included. Furthermore, the ...

  15. Use of Ceftolozane/Tazobactam in the Treatment of Multidrug-resistant Pseudomonas aeruginosa Bloodstream Infection in a Pediatric Leukemia Patient.

    Science.gov (United States)

    Aitken, Samuel L; Kontoyiannis, Dimitrios P; DePombo, April M; Bhatti, Micah M; Tverdek, Frank P; Gettys, Suzanne C; Nicolau, David P; Nunez, Cesar A

    2016-09-01

    Multidrug-resistant Pseudomonas aeruginosa is of increasing concern in pediatric patients. Ceftolozane/tazobactam is a novel cephalosporin/β-lactamase inhibitor combination with activity against multidrug-resistant Pseudomonas; however, no data exist on its use in children. This report summarizes the treatment of a multidrug-resistant P. aeruginosa bloodstream infection in a pediatric leukemia patient with ceftolozane/tazobactam and provides the first description of its pharmacokinetics in pediatrics. PMID:27254038

  16. Long-term, low-dose tigecycline to treat relapsing bloodstream infection due to KPC-producing Klebsiella pneumoniae after major hepatic surgery

    OpenAIRE

    Luca Morelli; Dario Tartaglia; Niccolò Furbetta; Matteo Palmeri; Simone Ferranti; Enrico Tagliaferri; Giulio Di Candio; Franco Mosca

    2015-01-01

    A 68-year-old male underwent a right hepatectomy, resection of the biliary convergence, and a left hepatic jejunostomy for a Klatskin tumour. The postoperative course was complicated by biliary abscesses with relapsing bloodstream infections due to Klebsiella pneumoniae carbapenemase (KPC)-producing Klebsiella pneumoniae (KPC-Kp). A 2-week course of combination antibiotic therapy failed to provide source control and the bacteraemia relapsed. Success was obtained with a regimen of tigecycline ...

  17. Timing of positive blood samples does not differentiate pathogens causing healthcare-associated from community-acquired bloodstream infections in children in England: a linked retrospective cohort study

    OpenAIRE

    Henderson, K. L.; MÜLLER-PEBODY, B.; WADE, A.; Sharland, M.; MINAJI, M.; Johnson, A P; Gilbert, R.

    2014-01-01

    SUMMARY Paediatricians recognize that using the time-dependent community-acquired vs. hospital-acquired bloodstream infection (BSI) dichotomy to guide empirical treatment no longer distinguishes between causative pathogens due to the emergence of healthcare-associated BSIs. However, paediatric epidemiological evidence of the aetiology of BSIs in relation to hospital admission in England is lacking. For 12 common BSI-causing pathogens in England, timing of laboratory reports of positive paedia...

  18. Linkage, evaluation and analysis of national electronic healthcare data: application to providing enhanced blood-stream infection surveillance in paediatric intensive care.

    OpenAIRE

    Katie Harron; Harvey Goldstein; Angie Wade; Berit Muller-Pebody; Roger Parslow; Ruth Gilbert

    2013-01-01

    Background: Linkage of risk-factor data for blood-stream infection (BSI) in paediatric intensive care (PICU) withbacteraemia surveillance data to monitor risk-adjusted infection rates in PICU is complicated by a lack of uniqueidentifiers and under-ascertainment in the national surveillance system. We linked, evaluated and performedpreliminary analyses on these data to provide a practical guide on the steps required to handle linkage of suchcomplex data sources.Methods: Data on PICU admissions...

  19. Risk of bloodstream infection in children admitted to paediatric intensive care units in England and Wales following emergency inter-hospital transfer.

    OpenAIRE

    Harron, K.; Mok, Q; Parslow, R.; Muller-Pebody, B; Gilbert, R.; Ramnarayan, P

    2014-01-01

    Purpose Adherence to full sterile procedures may be compromised when central venous catheters are inserted as part of emergency resuscitation and stabilisation, particularly outside the intensive care unit. Half of emergency admissions to paediatric intensive care units (PICU) in the UK occur after stabilisation at other hospitals. We determined whether bloodstream infection (BSI) occurred more frequently in children admitted to PICU after inter-hospital transfer compared to within-hospital a...

  20. Detection of mycobacteria in the bloodstream of patients with Acquired Immunodeficiency Syndrome in a University Hospital in Brazil

    Directory of Open Access Journals (Sweden)

    Carmen Paz Oplustil

    2001-10-01

    Full Text Available This study was done to determine the occurrence of mycobacteria in the bloodstreams of patients with fever and advanced AIDS in a Brazilian hospital. We also verified the capability of an automated method for recovering these bacteria. During a period of 19 months, 254 patients with AIDS were evaluated. Blood cultures were generally submitted in pairs and drawn separately. Blood cultures were processed by the BACTEC 460TB System (Becton Dickinson Microbiology Systems, Sparks, MD, using the Bactec 13A media (Becton Dickinson Microbiology Systems, Sparks, MD. Of the 530 vials submitted, 77 (14.5% from 41 (16% patients were positive. Mycobacterium avium complex was recovered from 45 (58.4% of the 77 positive vials, corresponding to 22 (53.6% patients with positive blood cultures. The average time to detect Mycobacterium avium complex was 15 days. Mycobacterium tuberculosis was recovered from 26 (33.8% of the 77 positive vials, corresponding to 15 (36.6% patients with positive blood cultures, with an average detection time of 24 days. Other species of mycobacteria were recovered from 6 (7.8% of the 77 vials, corresponding to 4 (9.8% patients. M.avium complex was fairly prevalent (8.7% in severely ill patients with AIDS in our hospital. M. tuberculosis was also an important (6.0% agent of systemic bacterial infections in these patients. The rapid diagnosis of mycobacteremia was possible with the implementation of this automated technology.

  1. Cefazolin versus Nafcillin for Methicillin-Sensitive Staphylococcus aureus Bloodstream Infection in a California Tertiary Medical Center.

    Science.gov (United States)

    Pollett, S; Baxi, S M; Rutherford, G W; Doernberg, S B; Bacchetti, P; Chambers, H F

    2016-08-01

    Recent observational studies have suggested possible reductions in mortality in patients receiving cefazolin versus antistaphylococcal penicillins. We examined 90-day mortality in patients receiving cefazolin compared to nafcillin for methicillin-susceptible Staphylococcus aureus (MSSA) bloodstream infection (BSI). We identified persons with MSSA BSI admitted to San Francisco General Hospital from January 2008 to July 2013 through a hospital-wide infection surveillance system and confirmed 90-day mortality using U.S. national vital registries. We included persons receiving cefazolin or nafcillin as the predominant intravenous antimicrobial agent; all participants received inpatient Infectious Diseases service consultation. We estimated the association between receipt of cefazolin and 90-day risk of death by multivariate logistic regression, including a propensity score for receiving cefazolin as the second predictor. Of 230 MSSA BSI cases, 30 received nafcillin and 70 received cefazolin as the predominant antimicrobial; 10 died within 90 days, 5 from each group. Unadjusted analysis showed substantial but not statistically significant reduced odds of death in those receiving cefazolin (odds ratio, 0.38; 95% confidence interval [CI], 0.10 to 1.44). Multivariate analysis with propensity scores found a similar adjusted odds ratio (0.40; 95% CI, 0.09 to 1.74; P = 0.22). We found a large reduction in 90-day mortality in those receiving cefazolin compared to nafcillin for MSSA BSI, but this finding was not statistically significant. The magnitude of effect seen in this and other studies justifies further study. PMID:27216053

  2. The impact of HIV infection on blood leukocyte responsiveness to bacterial stimulation in asymptomatic patients and patients with bloodstream infection

    Science.gov (United States)

    Huson, Michaëla A M; Hoogendijk, Arie J; de Vos, Alex F; Grobusch, Martin P; van der Poll, Tom

    2016-01-01

    Introduction HIV-induced changes in cytokine responses to bacteria may influence susceptibility to bacterial infections and the consequent inflammatory response. Methods We examined the impact of HIV on whole blood responsiveness to bacterial stimulation in asymptomatic subjects and patients with bacterial bloodstream infection (BSI). Whole blood was stimulated ex vivo with two bacterial Toll-like receptor agonists (lipopolysaccharide and lipoteichoic acid) and two pathogens (Streptococcus pneumoniae and non-typhoidal Salmonella), which are relevant in HIV-positive patients. Production of interferon-γ, tumour necrosis factor-α, interleukin-1β and interleukin-6 was used as a read-out. Results In asymptomatic subjects, HIV infection was associated with reduced interferon-γ, release after stimulation and priming of the pro-inflammatory cytokine response to non-typhoidal Salmonella. In patients with BSI, we found no such priming effect, nor was there evidence for more profound sepsis-induced immunosuppression in BSI patients with HIV co-infection. Conclusions These results suggest a complex effect of HIV on leukocyte responses to bacteria. However, in patients with sepsis, leukocyte responses were equally blunted in patients with and without HIV infection. PMID:27189532

  3. Comparison of severity of illness scoring systems for patients with nosocomial bloodstream infection due to Pseudomonas aeruginosa

    Directory of Open Access Journals (Sweden)

    Wenzel Richard P

    2006-08-01

    Full Text Available Abstract Background Several acute illness severity scores have been proposed for evaluating patients on admission to intensive care units but these have not been compared for patients with nosocomial bloodstream infection (nBSI. We compared three severity of illness scoring systems for predicting mortality in patients with nBSI due to Pseudomonas aeruginosa. Methods We performed a historical cohort study on 63 adults in intensive care units with P. aeruginosa monomicrobial nBSI. Results The Acute Physiology, Age, Chronic Health Evaluation II (APACHE II, Sequential Organ Failure Assessment (SOFA, and Simplified Acute Physiologic Score (SAPS II, were calculated daily from 2 days prior through 2 days after the first positive blood culture. Calculation of the area under the receiver operating characteristic (ROC curve confirmed that APACHE II and SAPS II at day -1 and SOFA at day +1 were better predictors of outcome than days -2, 0 and day 2 of BSI. By stepwise logistic regression analysis of these three scoring systems, SAPS II (OR: 13.03, CI95% 2.51–70.49 and APACHE II (OR: 12.51, CI95% 3.12–50.09 on day -1 were the best predictors for mortality. Conclusion SAPS II and APACHE II are more accurate than the SOFA score for predicting mortality in this group of patients at day -1 of BSI.

  4. A 12-year review of Staphylococcus aureus bloodstream infections in haemodialysis patients: more work to be done.

    LENUS (Irish Health Repository)

    Fitzgerald, S F

    2012-02-01

    Staphylococcus aureus bloodstream infections (BSI) are a significant cause of morbidity and mortality in haemodialysis patients. This study describes a 12-year retrospective review of S. aureus BSI in a large haemodialysis centre in a tertiary referral hospital. The overall rate of S. aureus BSI was 17.9 per 100 patient-years (range 9.7-36.8). The rate of meticillin-resistant S. aureus (MRSA) BSI was 5.6 per 100 patient-years (range 0.9-13.8). Infective complications occurred in 11% of episodes, the most common being infective endocarditis (7.6%). Ten percent of patients died within 30 days of S. aureus being isolated from blood. Most cases of S. aureus BSI (83%) were related to vascular catheters. The provision of lower-risk vascular access, such as arteriovenous fistulae, and reduced use of intravascular catheters should be priorities in all haemodialysis units. Where alternative vascular access cannot be established, interventions to reduce the risk of catheter-related infections should be implemented to reduce morbidity and mortality in this vulnerable patient group.

  5. Surveillance of bloodstream infections in pediatric cancer centers – what have we learned and how do we move on?

    Directory of Open Access Journals (Sweden)

    Simon, Arne

    2016-05-01

    Full Text Available Pediatric patients receiving conventional chemotherapy for malignant disease face an increased risk of bloodstream infection (BSI. Since BSI may represent an acute life-threatening event in patients with profound immunosuppression, and show further negative impact on quality of life and anticancer treatment, the prevention of BSI is of paramount importance to improve and guarantee patients’ safety during intensive treatment. The great majority of all pediatric cancer patients (about 85% have a long-term central venous access catheter in use (type Broviac or Port; CVAD. Referring to the current surveillance definitions a significant proportion of all BSI in pediatric patients with febrile neutropenia is categorized as CVAD- BSI. This state of the art review summarizes the epidemiology and the distinct pathogen profile of BSI in pediatric cancer patients from the perspective of infection surveillance. Problems in executing the current surveillance definition in this patient population are discussed and a new concept for the surveillance of BSI in pediatric cancer patients is outlined.

  6. CLABSI Conversations: Lessons From Peer-to-Peer Assessments to Reduce Central Line-Associated Bloodstream Infections.

    Science.gov (United States)

    Pham, Julius Cuong; Goeschel, Christine A; Berenholtz, Sean M; Demski, Renee; Lubomski, Lisa H; Rosen, Michael A; Sawyer, Melinda D; Thompson, David A; Trexler, Polly; Weaver, Sallie J; Weeks, Kristina R; Pronovost, Peter J

    2016-01-01

    A national collaborative helped many hospitals dramatically reduce central line-associated bloodstream infections (CLABSIs), but some hospitals struggled to reduce infection rates. This article describes the development of a peer-to-peer assessment process (CLABSI Conversations) and the practical, actionable practices we discovered that helped intensive care unit teams achieve a CLABSI rate of less than 1 infection per 1000 catheter-days for at least 1 year. CLABSI Conversations was designed as a learning-oriented process, in which a team of peers visited hospitals to surface barriers to infection prevention and to share best practices and insights from successful intensive care units. Common practices led to 10 recommendations: executive and board leaders communicate the goal of zero CLABSI throughout the hospital; senior and unit-level leaders hold themselves accountable for CLABSI rates; unit physicians and nurse leaders own the problem; clinical leaders and infection preventionists build infection prevention training and simulation programs; infection preventionists participate in unit-based CLABSI reduction efforts; hospital managers make compliance with best practices easy; clinical leaders standardize the hospital's catheter insertion and maintenance practices and empower nurses to stop any potentially harmful acts; unit leaders and infection preventionists investigate CLABSIs to identify root causes; and unit nurses and staff audit catheter maintenance policies and practices. PMID:27031355

  7. Collaborative form(s)

    DEFF Research Database (Denmark)

    Gunn, Wendy

    Gunn asks us to consider beauty as collaborative forms of action generated by moving between design by means of anthropology and anthropology by means of design. Specifically, she gives focus to play-like reflexions on practices of designing energy products, systems and infrastructure. Design...... anthropology engages groups of people within collaborative, interdisciplinary, inter-organizational design processes and co-analytic activities vs. the individual anthropologist conducting studies of people. In doing anthropology by means of design as Gatt and Ingold (2013) have shown, design is considered the...... premise designing as a social process and can be understood as a material engagement and constructive critique involving participant observation....

  8. Constitute and antifungal susceptibility of Candida spp . causing blood-stream infection%血流感染假丝酵母菌菌种构成及其药物敏感性

    Institute of Scientific and Technical Information of China (English)

    徐鸣皋; 丁进亚; 徐娟; 孙洁

    2016-01-01

    Objective To analyze the constitute and antifungal susceptibility of Candida spp . causing bloodstream infection in a hospital,so as to provide evidence for the prevention and treatment of bloodstream infection caused by Candida spp .Methods Candida spp . isolated from blood specimens of clinical patients in a hospital between 2009 and 2013 were analyzed retrospectively,the high risk factors for Candida bloodstream infection were analyzed. Results A total of 42 isolates of Candida spp . were isolated from blood specimens of 42 patients between 2009 and 2013,the major was Candida parapsilosis (C.parapsilosis ,n =20,47.62%),followed by C.albicans (n =16, 38.10%),C.tropicalis (n=4,9.52%),and C.glabrata(n=2,4.76%).Candida spp .were mainly distributed in emergency intensive care unit(n=11),departments of urologic surgery (n=9)and cardiothoracic surgery(n=8). The venous catheters of 37 patients(88.10%)were isolated the same Candida spp . as blood culture,the average time from indwelling venous catheters to positive culture of blood and catheters were 31 .47 and 33.18 days respec-tively;the percentage of positive culture for blood and catheters both increased with the prolongation of catheteriza-tion (both P < 0.001 ).Susceptibility rates of Candida spp . to fluconazole and voriconazole were 75.00% -100.00%,to amphotericin B were all 100.00%,to itraconazole varied significantly with different species (0 -87.50%).Conclusion The major Candida strains causing bloodstream infection in this hospital is C.parapsilosis , and is related to the use of intravenous catheters,susceptibility rates to fluconazole,amphotericin B,and voricon-azole are all high.%目的:分析某院假丝酵母菌血流感染菌种构成及其对抗真菌药物的敏感性,为临床预防和治疗假丝酵母菌血流感染提供依据。方法回顾性分析2009—2013年该院临床科室送检血标本中检出的假丝酵母菌,并对假丝酵母菌血流感染的高

  9. Strain measurements at railway wheels

    International Nuclear Information System (INIS)

    The development of the radial strain component in railway wheels was investigated by neutron diffraction. In the as manufactured state four railway wheels were investigated. In all four wheels no significant strains were found. After 18,400 km usage first strain gradients close to the outer surface of the wheels were detected. In axial middle ranges the changes in strain are weak. After an usage of 61,000 km the gradients becomes strong at the axial outer position between about +700 με close below the tread and -500 με in a depth of 12.5 mm below the tread. At axial middle positions also strain gradients are formed. The end of live state (510,000 km) differs only slightly from the state measured after a usage of 61,000 km

  10. FACTORS ASSOCIATED WITH MORTALITY AMONG PATIENTS WITH CENTRAL VENOUS CATHETER-RELATED BLOODSTREAM INFECTION IN AN INTENSIVE CARE UNIT

    Directory of Open Access Journals (Sweden)

    Priscilla Roberta Silva Rocha

    2012-01-01

    Full Text Available Central venous catheterization is a common practice in the management of critically ill patients and is associated with various complications, such as Bloodstream Infections (BSI, which are major determinants of increased morbidity, mortality and healthcare expenses. Few studies have addressed factors that predict mortality in patients with this complication. The aim of this study was to investigate factors associated with mortality in patients with Central Venous Catheter (CVC-related BSI in an intensive care unit of a tertiary care hospital in the Federal District, Brazil. This was a retrospective and observational study, in which all CVC-related BSI that occurred between January 2008 and December 2010 were reviewed. We obtained demographic, clinical, biochemical and microbiological data from medical records and investigated its association with mortality during ICU stay. There were 4,504 ICU admissions during the study period and 68 were complicated by CVC-related BSI (4.09 per 1000 catheter-days, most due to gram-negative organisms (45.6%. Overall mortality was 59.7%. Death risk was significantly associated with mechanical ventilation (OR 27.8, 95% CI 3.28-250, p-1 in survivors vs. 73.9 mg dL-1 in non-survivors, p = 0.001. Mortality was not associated with other clinical or biochemical features, neither with microbiological variables, although lethality was high among patients with gram-positive infections (77% Vs 58.33% for fungi and 54.83% for gram-negative. CVC-related BSI was associated with high absolute mortality, which was predicted by mechanical ventilation and a higher number of invasive devices other than the CVC. Knowledge of local factors predictive of mortality is critical for planning strategies to reduce death risk associated with this complication.

  11. Nosocomial bloodstream infection in patients caused by Staphylococcus aureus: drug susceptibility, outcome, and risk factors for hospital mortality

    Institute of Scientific and Technical Information of China (English)

    CHEN Rong; YAN Zhong-qiang; FENG Dan; LUO Yan-ping; WANG Lei-li; SHEN Ding-xia

    2012-01-01

    Background Previous studies have different viewpoints about the clinical impact of methicillin resistance on mortality of hospital-acquired bloodstream infection (BSI) patients with Staphylococcus aureus (S.aureus).The objective of this study was to investigate the mortality of hospital-acquired BSI with S.aureus in a military hospital and analyze the risk factors for the hospital mortality.Methods A retrospective cohort study was performed in patients admitted to the biggest military tertiary teaching hospital in China between January 2006 and May 2011.All included patients had clinically significant nosocomial BSI with S.aureus.Multivariate Logistic regression analysis was used to identify the risk factors for hospital mortality of patients with S.aureus BSI.Results One hundred and eighteen patients of more than one year old were identified as clinically and microbiologically confirmed nosocomial bacteraemia due to S.aureus,and 75 out of 118 patients were infected with methicillin-resistant S.aureus (MRSA).The overall mortality of nosocomial S.aureus BSI was 28.0%.Methicillin resistance in S.aureus bacteremia was associated with significant increase in the length of hospitalization and high proportion of inappropriate empirical antibiotic treatment.After Logistic regression analysis,the severity of clinical manifestations (APACHE Ⅱ score) (odds ratio (OR) 1.22,95% confidence interval (CI) 1.12-1.34) and inadequacy of empirical antimicrobial therapy (OR 0.25,95% CI 0.09-0.69) remained as risk factors for hospital mortality.Conclusions Nosocomial S.aureus BSI was associated with high in-hospital mortality.Methicillin resistance in S.aureus has no significant impact on the outcome of patients with staphylococcal bacteremia.Proper empirical antimicrobial therapy is very important to the prognosis.

  12. EFFECT OF INFLIXIMAB ON PARAMETERS OF REMODELING OF ARTERIAL BLOODSTREAM, RANKL AND OSTEOPROTEGERIN LEVELS IN PATIENTS WITH RHEUMATOID ARTHRITIS

    Directory of Open Access Journals (Sweden)

    Larisa Aleksandrovna Knyazeva

    2014-02-01

    Full Text Available Objective. To study the effect of infliximab (INF on serum levels of RANKL and osteoprotegerin (OPG, as well as on structural and functional properties of the vascular wall in patients with rheumatoid arthritis (RA.Material and Methods. A total of 79 RA patients who corresponded to the classification criteria ACR (1987 or ACR/EULAR (2010 and were seronegative for IgM rheumatoid factor (RF were examined. The mean age of patients was 43.6±8.5 years. The serum levels of OPG and RANKL were determined by ELISA (Biomedica, Austria; the common carotid arteries (CCAs were visualized using an Acuson X/10 ultrasonic complex equipped with a 7 MHz linear sensor in the β-mode prior to therapy and after 12-month therapy with INF.Results and Discussion. An increased OPG level was observed mostly in patients with RA duration up to 1 year; an increase in RANKL level was pronounced stronger in patients with PA duration over 2 years. The disturbance of structural and functional properties of the arterial bloodstream was revealed, manifesting itself as an increase in the intimamedia complex thickness, diameter and rigidity index of CCA that were stronger pronounced in patients with late onset RA. A correlation analysis showed the presence of reliable relationship between the RANKL and OPG levels and CCA remodeling parameters. INF therapy showed high clinical effectiveness and correction effect on the RANKL/OPG system. In addition, it was accompanied by a reduction of signs of CCA remodeling, which was stronger pronounced in patients with early RA.Conclusion. The results prove the reasonability of using INF at early stages of RA in order to optimize the therapy and achieve more efficient control of cardiovascular complications.

  13. Bloodstream infection in patients with end-stage renal disease in a teaching hospital in central-western Brazil

    Directory of Open Access Journals (Sweden)

    Tamara Trelha Gauna

    2013-08-01

    Full Text Available Introduction Vascular access in patients undergoing hemodialysis is considered a critical determinant of bloodstream infection (BSI and is associated with high morbidity and mortality. The purpose of this study was to investigate the occurrence of BSI in patients with end-stage renal disease using central venous catheters for hemodialysis. Methods A cohort study was conducted in a public teaching hospital in central-western Brazil from April 2010 to December 2011. For every patient, we noted the presence of hyperemia/exudation upon catheter insertion, as well as fever, shivering, and chills during hemodialysis. Results Fifty-nine patients were evaluated. Thirty-five (59.3% patients started dialysis due to urgency, 37 (62.7% had BSI, and 12 (20% died. Hyperemia at the catheter insertion site (64.9% was a significant clinical manifestation in patients with BSI. Statistical analysis revealed 1.7 times more cases of BSI in patients with hypoalbuminemia compared with patients with normal albumin levels. The principal infective agents identified in blood cultures and catheter-tip cultures were Staphylococcus species (24 cases, non-fermentative Gram-negative bacilli (7 cases of Stenotrophomonas maltophilia and 5 cases of Chryseobacterium indologenes, and Candida species (6. Among the Staphylococci identified, 77.7% were methicillin-resistant, coagulase-negative Staphylococci. Of the bacteria isolated, the most resistant were Chryseobacterium indologenes and Acinetobacter baumannii. Conclusions Blood culture was demonstrated to be an important diagnostic test and identified over 50% of positive BSI cases. The high frequency of BSI and the isolation of multiresistant bacteria were disturbing findings. Staphylococcus aureus was the most frequently isolated microorganism, although Gram-negative bacteria predominated overall. These results highlight the importance of infection prevention and control measures in dialysis units.

  14. Comparison of pathogen DNA isolation methods from large volumes of whole blood to improve molecular diagnosis of bloodstream infections.

    Directory of Open Access Journals (Sweden)

    Anne J M Loonen

    Full Text Available For patients suffering from bloodstream infections (BSI molecular diagnostics from whole blood holds promise to provide fast and adequate treatment. However, this approach is hampered by the need of large blood volumes. Three methods for pathogen DNA isolation from whole blood were compared, i.e. an enzymatic method (MolYsis, 1-5 ml, the novel non-enzymatic procedure (Polaris, 1-5 ml, and a method that does not entail removal of human DNA (Triton-Tris-EDTA EasyMAG, 200 µl. These methods were evaluated by processing blood spiked with 0-1000 CFU/ml of Staphylococcus aureus, Pseudomonas aeruginosa and Candida albicans. Downstream detection was performed with real-time PCR assays. Polaris and MolYsis processing followed by real-time PCRs enabled pathogen detection at clinically relevant concentrations of 1-10 CFU/ml blood. By increasing sample volumes, concurrent lower cycle threshold (Ct values were obtained at clinically relevant pathogen concentrations, demonstrating the benefit of using larger blood volumes. A 100% detection rate at a concentration of 10 CFU/ml for all tested pathogens was obtained with the Polaris enrichment, whereas comparatively lower detection rates were measured for MolYsis (50-67% and EasyMAG (58-79%. For the samples with a concentration of 1 CFU/ml Polaris resulted in most optimal detection rates of 70-75% (MolYsis 17-50% and TTE-EasyMAG 20-36%. The Polaris method was more reproducible, less labour intensive, and faster (45 minutes (including Qiagen DNA extraction vs. 2 hours (MolYsis. In conclusion, Polaris and MolYsis enrichment followed by DNA isolation and real-time PCR enables reliable and sensitive detection of bacteria and fungi from 5 ml blood. With Polaris results are available within 3 hours, showing potential for improved BSI diagnostics.

  15. The health and economic burden of bloodstream infections caused by antimicrobial-susceptible and non-susceptible Enterobacteriaceae and Staphylococcus aureus in European hospitals, 2010 and 2011: a multicentre retrospective cohort study.

    Science.gov (United States)

    Stewardson, Andrew J; Allignol, Arthur; Beyersmann, Jan; Graves, Nicholas; Schumacher, Martin; Meyer, Rodolphe; Tacconelli, Evelina; De Angelis, Giulia; Farina, Claudio; Pezzoli, Fabio; Bertrand, Xavier; Gbaguidi-Haore, Houssein; Edgeworth, Jonathan; Tosas, Olga; Martinez, Jose A; Ayala-Blanco, M Pilar; Pan, Angelo; Zoncada, Alessia; Marwick, Charis A; Nathwani, Dilip; Seifert, Harald; Hos, Nina; Hagel, Stefan; Pletz, Mathias; Harbarth, Stephan

    2016-08-18

    We performed a multicentre retrospective cohort study including 606,649 acute inpatient episodes at 10 European hospitals in 2010 and 2011 to estimate the impact of antimicrobial resistance on hospital mortality, excess length of stay (LOS) and cost. Bloodstream infections (BSI) caused by third-generation cephalosporin-resistant Enterobacteriaceae (3GCRE), meticillin-susceptible (MSSA) and -resistant Staphylococcus aureus (MRSA) increased the daily risk of hospital death (adjusted hazard ratio (HR) = 1.80; 95% confidence interval (CI): 1.34-2.42, HR = 1.81; 95% CI: 1.49-2.20 and HR = 2.42; 95% CI: 1.66-3.51, respectively) and prolonged LOS (9.3 days; 95% CI: 9.2-9.4, 11.5 days; 95% CI: 11.5-11.6 and 13.3 days; 95% CI: 13.2-13.4, respectively). BSI with third-generation cephalosporin-susceptible Enterobacteriaceae (3GCSE) significantly increased LOS (5.9 days; 95% CI: 5.8-5.9) but not hazard of death (1.16; 95% CI: 0.98-1.36). 3GCRE significantly increased the hazard of death (1.63; 95% CI: 1.13-2.35), excess LOS (4.9 days; 95% CI: 1.1-8.7) and cost compared with susceptible strains, whereas meticillin resistance did not. The annual cost of 3GCRE BSI was higher than of MRSA BSI. While BSI with S. aureus had greater impact on mortality, excess LOS and cost than Enterobacteriaceae per infection, the impact of antimicrobial resistance was greater for Enterobacteriaceae. PMID:27562950

  16. A rapid method for testing in vivo the susceptibility of different strains of Trypanosoma cruzi to active chemotherapeutic agents

    Directory of Open Access Journals (Sweden)

    Leny S. Filardi

    1984-06-01

    Full Text Available A method is described which permits to determine in vivo an in a short period of time (4-6 hours the sensitivity of T. cruzo strains to known active chemotherapeutic agents. By using resistant- and sensitive T. cruzi stains a fairly good correlation was observed between the results obtained with this rapid method (which detects activity against the circulating blood forms and those obtained with long-term schedules which involve drug adminstration for at least 20 consecutive days and a prolonged period of assessment. This method may be used to characterize susceptibility to active drugs used clinically, provide infomation on the specific action against circulating trypomastigotes and screen active compounds. Differences in the natural susceptibility of Trypanosoma cruzi strains to active drugs have been already reported using different criteria, mostly demanding long-term study of the animal (Hauschka, 1949; Bock, Gonnert & Haberkorn, 1969; Brener, Costa & Chiari, 1976; Andrade & Figueira, 1977; Schlemper, 1982. In this paper we report a method which detects in 4-6 hours the effect of drugs on bloodstream forms in mice with established T. cruzi infections. The results obtained with this method show a fairly good correlation with those obtained by prolonged treatment schedules used to assess the action of drugs in experimental Chagas' disease and may be used to study the sensitivity of T. cruzi strains to active drugs.No presente trabalho descreve-se um metodo que permite determinar in vivo e em curto espaço de tempo (4-6 horas a sensibilidade de cepas de T. cruzi a agentes terapeuticos ativos na doença de Chagas. Usando-se cepas sensíveis e resistentes aos medicamentos foi possível observar uma boa correlação entre os resultados obtidos com o método rápido (que detecta atividade contra as formas circulantes do parasita e aqueles obtidos com esquema de acao prolongada que envolve a administração da droga por 20 dias e posterior avalia

  17. Covalent functionalization of strained graphene

    OpenAIRE

    Boukhvalov, Danil W.; Son, Young-Woo

    2012-01-01

    Enhancement of the chemical activity of graphene is evidenced by first-principles modelling of chemisorption of the hydrogen, fluorine, oxygen and hydroxyl groups on strained graphene. For the case of negative strain or compression, chemisorption of the single hydrogen, fluorine or hydroxyl group is energetically more favourable than those of their pairs on different sublattices. This behaviour stabilizes the magnetism caused by the chemisorption being against its destruction by the pair form...

  18. Low TCR nanocomposite strain gages

    Science.gov (United States)

    Gregory, Otto J. (Inventor); Chen, Ximing (Inventor)

    2012-01-01

    A high temperature thin film strain gage sensor capable of functioning at temperatures above 1400.degree. C. The sensor contains a substrate, a nanocomposite film comprised of an indium tin oxide alloy, zinc oxide doped with alumina or other oxide semiconductor and a refractory metal selected from the group consisting of Pt, Pd, Rh, Ni, W, Ir, NiCrAlY and NiCoCrAlY deposited onto the substrate to form an active strain element. The strain element being responsive to an applied force.

  19. In vitro and in vivo studies of the antiparasitic activity of sterol 14α-demethylase (CYP51) inhibitor VNI against drug-resistant strains of Trypanosoma cruzi.

    Science.gov (United States)

    Soeiro, Maria de Nazaré Correia; de Souza, Elen Mello; da Silva, Cristiane França; Batista, Denise da Gama Jaen; Batista, Marcos Meuser; Pavão, Beatriz Philot; Araújo, Julianna Siciliano; Aiub, Claudia Alessandra Fortes; da Silva, Patrícia Bernardino; Lionel, Jessica; Britto, Constança; Kim, Kwangho; Sulikowski, Gary; Hargrove, Tatiana Y; Waterman, Michael R; Lepesheva, Galina I

    2013-09-01

    Chagas disease affects more than 10 million people worldwide, and yet, as it has historically been known as a disease of the poor, it remains highly neglected. Two currently available drugs exhibit severe toxicity and low effectiveness, especially in the chronic phase, while new drug discovery has been halted for years as a result of a lack of interest from pharmaceutical companies. Although attempts to repurpose the antifungal drugs posaconazole and ravuconazole (inhibitors of fungal sterol 14α-demethylase [CYP51]) are finally in progress, development of cheaper and more efficient, preferably Trypanosoma cruzi-specific, chemotherapies would be highly advantageous. We have recently reported that the experimental T. cruzi CYP51 inhibitor VNI cures with 100% survival and 100% parasitological clearance both acute and chronic murine infections with the Tulahuen strain of T. cruzi. In this work, we further explored the potential of VNI by assaying nitro-derivative-resistant T. cruzi strains, Y and Colombiana, in highly stringent protocols of acute infection. The data show high antiparasitic efficacy of VNI and its derivative (VNI/VNF) against both forms of T. cruzi that are relevant for mammalian host infection (bloodstream and amastigotes), with the in vivo potency, at 25 mg/kg twice a day (b.i.d.), similar to that of benznidazole (100 mg/kg/day). Transmission electron microscopy and reverse mutation tests were performed to explore cellular ultrastructural and mutagenic aspects of VNI, respectively. No mutagenic potential could be seen by the Ames test at up to 3.5 μM, and the main ultrastructural damage induced by VNI in T. cruzi was related to Golgi apparatus and endoplasmic reticulum organization, with membrane blebs presenting an autophagic phenotype. Thus, these preliminary studies confirm VNI as a very promising trypanocidal drug candidate for Chagas disease therapy. PMID:23774435

  20. Haemophilus ducreyi Cutaneous Ulcer Strains Are Nearly Identical to Class I Genital Ulcer Strains.

    Directory of Open Access Journals (Sweden)

    Dharanesh Gangaiah

    Full Text Available Although cutaneous ulcers (CU in the tropics is frequently attributed to Treponema pallidum subspecies pertenue, the causative agent of yaws, Haemophilus ducreyi has emerged as a major cause of CU in yaws-endemic regions of the South Pacific islands and Africa. H. ducreyi is generally susceptible to macrolides, but CU strains persist after mass drug administration of azithromycin for yaws or trachoma. H. ducreyi also causes genital ulcers (GU and was thought to be exclusively transmitted by microabrasions that occur during sex. In human volunteers, the GU strain 35000HP does not infect intact skin; wounds are required to initiate infection. These data led to several questions: Are CU strains a new variant of H. ducreyi or did they evolve from GU strains? Do CU strains contain additional genes that could allow them to infect intact skin? Are CU strains susceptible to azithromycin?To address these questions, we performed whole-genome sequencing and antibiotic susceptibility testing of 5 CU strains obtained from Samoa and Vanuatu and 9 archived class I and class II GU strains. Except for single nucleotide polymorphisms, the CU strains were genetically almost identical to the class I strain 35000HP and had no additional genetic content. Phylogenetic analysis showed that class I and class II strains formed two separate clusters and CU strains evolved from class I strains. Class I strains diverged from class II strains ~1.95 million years ago (mya and CU strains diverged from the class I strain 35000HP ~0.18 mya. CU and GU strains evolved under similar selection pressures. Like 35000HP, the CU strains were highly susceptible to antibiotics, including azithromycin.These data suggest that CU strains are derivatives of class I strains that were not recognized until recently. These findings require confirmation by analysis of CU strains from other regions.

  1. The potent enhancer activity of the polycythemic strain of spleen focus-forming virus in hematopoietic cells is governed by a binding site for Sp1 in the upstream control region and by a unique enhancer core motif, creating an exclusive target for PEBP/CBF.

    OpenAIRE

    Baum, C; Itoh, K; DE MEYER, J; Laker, C; Ito, Y.; Ostertag, W

    1997-01-01

    The polycythemic strain of the spleen focus-forming virus (SFFVp) contains the most potent murine retroviral enhancer configuration known so far for gene expression in myeloerythroid hematopoietic cells. In the present study, we mapped two crucial elements responsible for the high activity of the SFFVp enhancer to an altered upstream control region (UCR) containing a GC-rich motif (5'-GGGCGGG-3') and to a unique enhancer core (5'-TGCGGTC-3'). Acquisition of these motifs accounts for half of t...

  2. Strain Field Quantitative Measurement around GP Zones Formed by an Al-Zn-Mg-Cu Alloy Spray Deposition%喷射沉积Al-Zn-Mg-Cu合金GP区应变场的定量测试

    Institute of Scientific and Technical Information of China (English)

    侯小虎; 白朴存; 赵春旺; 邢永明

    2011-01-01

    In order to quantitatively measure the lattice strain distribution around GP zone. an Al122n2. 4Mg1. 1Cu alloy was prepared by spray deposition. Alloy samples were subsequently processed by hot extrusion, solid solution treatment at 758K for 2 hours and aging at 393K for 20 hours. The structure and strain field of GP zones in the alloy was experimentally investigated based on High Resolution Transmission Electon Microscopy (HRTEM) and geometric phase analysis (GPA).Experimental results show that obvious strain difference around GP zones are generated along different directions; the largest strain (εxx = -0. 092)occures along the habit plane normal direction of GP zones, the minimum value(εyy = -0. 004)occures along the habit plane parallel direction. Above results may explain the difference of hinder dislocation motion around GP zone. The difference of strain distribution along different directions around GP zone results in different strain strengthening effect, which causes the difference of hinder dislocation motion.%为定量测试喷射沉积合金GP区周围的晶格应变的分布,利用喷射成形技术制备了Al12Zn2.4Mg1.1Cu合金.随后对合金进行热挤压、758K固溶2小时和393K时效20小时处理.利用高分辨透射电子显微镜(High Resolution Transmission Electron Microscopy,HRTEM)和几何相位分析(Geometric Phase Analysis,GPA)软件对GP区的结构和应变场进行了测量和分析.结果表明,GP区附近的应变值在各方向差别较大,沿GP区惯习面法线方向的应变最大(εxx=-0.092),与惯习面平行方向上的应变最小(εyy=-0.004).该项结果可解释GP 区附近位错运动的差异:由于应变场在各方向上存在较大差别,产生的应变强化效果不同,导致阻碍位错运动的能力也有所不同.

  3. Strains in general relativity

    International Nuclear Information System (INIS)

    The definition of relative accelerations and strains among a set of comoving particles is studied in connection with the geometric properties of the frame adapted to a 'fiducial observer'. We find that a relativistically complete and correct definition of strains must take into account the transport law of the chosen spatial triad along the observer's congruence. We use special congruences of (accelerated) test particles in some familiar spacetimes to elucidate such a point. The celebrated idea of Szekeres' compass of inertia, arising when studying geodesic deviation among a set of free-falling particles, is here generalized to the case of accelerated particles. In doing so we have naturally contributed to the theory of relativistic gravity gradiometer. Moreover, our analysis was made in an observer-dependent form, a fact that would be very useful when thinking about general relativistic tests on space stations orbiting compact objects like black holes and also in other interesting gravitational situations

  4. Strains in General Relativity

    CERN Document Server

    Bini, Donato; Geralico, Andrea

    2014-01-01

    The definition of relative accelerations and strains among a set of comoving particles is studied in connection with the geometric properties of the frame adapted to a "fiducial observer." We find that a relativistically complete and correct definition of strains must take into account the transport law of the chosen spatial triad along the observer's congruence. We use special congruences of (accelerated) test particles in some familiar spacetimes to elucidate such a point. The celebrated idea of Szekeres' compass of inertia, arising when studying geodesic deviation among a set of free-falling particles, is here generalized to the case of accelerated particles. In doing so we have naturally contributed to the theory of relativistic gravity gradiometer. Moreover, our analysis was made in an observer-dependent form, a fact that would be very useful when thinking about general relativistic tests on space stations orbiting compact objects like black holes and also in other interesting gravitational situations.

  5. CORRELATION OF VOLUME BLOOD CIRCULATION IN THE HEPATIC ARTERY AND THE STATE OF MICROCIRCULATORY BLOODSTREAM OF THE TRANSPLANTED LIVER AFTER ITS REVASCULIZATION

    Directory of Open Access Journals (Sweden)

    D. A. Granov

    2014-01-01

    Full Text Available Aim: optimization of the surgical treatment policy with orthotopic liver transplantation (OLT depending on the results of intraoperative fl owmetry and the state of intrahepatic microcirculatory bloodstream according to immunohistochemical (IHC study of microspecimens of the donor’s liver.Materials and methods. 60 patients are included in the study. Group I (n = 30 comprised of patients for whom it was not necessary to perform any additional interventions on the bloodstream in the hepatopancreatobiliary area during OLT. Group II (n = 30 had patients with insuffi cient arterial blood supply for the graft in the intraoperative stage where it was needed to perform additional and/or repeated interventions in the arteries of the hepatopancreatobilliary area. Intraoperative fl owmetry with assessment of the volume blood circulation (VBC in the hepatic artery (HA was carried out in the both studied groups. Reference value of VBC was 100 ml/min and higher. Before and after reperfusion in the liver biopsy material we performed immunohistochemical study with the use of endothelial marker CD 31 with subsequent morphometric estimation of the specifi c square of the microvascular bloodstream.Results. In both groups there was no change in the specifi c square in the areas of portal tract and central vein before and after restoring blood fl ow. In the second group, an 8 times increase of the specifi c square of sinusoids was observed after restoring blood fl ow (р < 0,01.Conclusion. Intraoperative fl owmetric control of the blood fl ow allows in due time to perform surgical correction of the graft arterial blood supply during OLT, and it reduces the risk of thrombosis up to 0%. The value of VBC in the hepatic artery (HA has reliable dependence upon the state of microcirculatory bloodstream of cadaveric donor’s liver after reperfusion.

  6. Characteristics of neonates with culture-proven bloodstream infection who have low levels of C-reactive protein (≦10 mg/L)

    OpenAIRE

    Lai, Mei-Yin; Tsai, Ming-Horng; Lee, Chiang-Wen; Chiang, Ming-Chou; Lien, Reyin; Fu, Ren-Huei; Huang, Hsuan-Rong; Chu, Shih-Ming; Hsu, Jen-Fu

    2015-01-01

    Background Elevated C-reactive protein (CRP) level is widely used in clinical practice as a marker to distinguish between neonates with or without sepsis. However, some neonates with bacteremia have a CRP level within the normal range and they are not well characterized. Methods All episodes of neonatal culture-proven bloodstream infections (BSIs) between July 2004 and June 2012 were enrolled. Patients characteristics were compared for three CRP groups (low, ≤ 10 mg/L; intermediate, 11–100 mg...

  7. The use of minocycline-rifampin coated central venous catheters for exchange of catheters in the setting of staphylococcus aureus central line associated bloodstream infections

    OpenAIRE

    Chaftari, Anne-Marie; El Zakhem, Aline; Jamal, Mohamed A.; Jiang, Ying; Hachem, Ray; Raad, Issam

    2014-01-01

    Background Central venous catheters (CVC) removal and reinsertion of a new CVC in the setting of central line associated bloodstream infections (CLABSI) is not always possible in septic patients. The purpose of this study was to evaluate the outcome of patients with Staphylococcus aureus-CLABSI (SA-CLABSI) who had their CVCs exchanged over guidewire for minocycline/rifampin-coated (M/R)-CVC within seven days of bacteremia. Methods Each case was matched with two control patients who had SA-CLA...

  8. Long-term, low-dose tigecycline to treat relapsing bloodstream infection due to KPC-producing Klebsiella pneumoniae after major hepatic surgery.

    Science.gov (United States)

    Morelli, Luca; Tartaglia, Dario; Furbetta, Niccolò; Palmeri, Matteo; Ferranti, Simone; Tagliaferri, Enrico; Di Candio, Giulio; Mosca, Franco

    2015-07-01

    A 68-year-old male underwent a right hepatectomy, resection of the biliary convergence, and a left hepatic jejunostomy for a Klatskin tumour. The postoperative course was complicated by biliary abscesses with relapsing bloodstream infections due to Klebsiella pneumoniae carbapenemase (KPC)-producing Klebsiella pneumoniae (KPC-Kp). A 2-week course of combination antibiotic therapy failed to provide source control and the bacteraemia relapsed. Success was obtained with a regimen of tigecycline 100mg daily for 2 months, followed by tigecycline 50mg daily for 6 months, then 50mg every 48h for 3 months. No side effects were reported. PMID:25975648

  9. Detection of mcr-1 encoding plasmid-mediated colistin-resistant Escherichia coli isolates from human bloodstream infection and imported chicken meat, Denmark 2015.

    Science.gov (United States)

    Hasman, Henrik; Hammerum, Anette M; Hansen, Frank; Hendriksen, Rene S; Olesen, Bente; Agersø, Yvonne; Zankari, Ea; Leekitcharoenphon, Pimlapas; Stegger, Marc; Kaas, Rolf S; Cavaco, Lina M; Hansen, Dennis S; Aarestrup, Frank M; Skov, Robert L

    2015-01-01

    The plasmid-mediated colistin resistance gene, mcr-1, was detected in an Escherichia coli isolate from a Danish patient with bloodstream infection and in five E. coli isolates from imported chicken meat. One isolate from chicken meat belonged to the epidemic spreading sequence type ST131. In addition to IncI2, an incX4 replicon was found to be linked to mcr-1. This report follows a recent detection of mcr-1 in E. coli from animals, food and humans in China. PMID:26676364

  10. FORM development

    OpenAIRE

    Vermaseren, J. A. M.

    2011-01-01

    I give an overview of FORM development based on a few pilot projects, explaining how they have influenced the FORM capabilities. Next I explain what is happnening right now in the field of Open Sourcing and the FORM Forum.

  11. Local strains in waste tank deflagration analysis

    International Nuclear Information System (INIS)

    In recent years extensive effort has been expended to qualify buried nuclear waste storage tanks under accident conditions. One of these conditions is deflagration of the combustible gases which may build up over time. While much work has been done to calculate the general strain state, less effort has been made to address the local strains at structural discontinuities. An analytical method is presented for calculating these local strains and combining them with the general strain state. A closed form solution of the local strains is compared to a finite element solution

  12. Improved hospital-level risk adjustment for surveillance of healthcare-associated bloodstream infections: a retrospective cohort study

    Directory of Open Access Journals (Sweden)

    Jones MA

    2009-09-01

    Full Text Available Abstract Background To allow direct comparison of bloodstream infection (BSI rates between hospitals for performance measurement, observed rates need to be risk adjusted according to the types of patients cared for by the hospital. However, attribute data on all individual patients are often unavailable and hospital-level risk adjustment needs to be done using indirect indicator variables of patient case mix, such as hospital level. We aimed to identify medical services associated with high or low BSI rates, and to evaluate the services provided by the hospital as indicators that can be used for more objective hospital-level risk adjustment. Methods From February 2001-December 2007, 1719 monthly BSI counts were available from 18 hospitals in Queensland, Australia. BSI outcomes were stratified into four groups: overall BSI (OBSI, Staphylococcus aureus BSI (STAPH, intravascular device-related S. aureus BSI (IVD-STAPH and methicillin-resistant S. aureus BSI (MRSA. Twelve services were considered as candidate risk-adjustment variables. For OBSI, STAPH and IVD-STAPH, we developed generalized estimating equation Poisson regression models that accounted for autocorrelation in longitudinal counts. Due to a lack of autocorrelation, a standard logistic regression model was specified for MRSA. Results Four risk services were identified for OBSI: AIDS (IRR 2.14, 95% CI 1.20 to 3.82, infectious diseases (IRR 2.72, 95% CI 1.97 to 3.76, oncology (IRR 1.60, 95% CI 1.29 to 1.98 and bone marrow transplants (IRR 1.52, 95% CI 1.14 to 2.03. Four protective services were also found. A similar but smaller group of risk and protective services were found for the other outcomes. Acceptable agreement between observed and fitted values was found for the OBSI and STAPH models but not for the IVD-STAPH and MRSA models. However, the IVD-STAPH and MRSA models successfully discriminated between hospitals with higher and lower BSI rates. Conclusion The high model goodness

  13. Use of the Tego needlefree connector is associated with reduced incidence of catheter-related bloodstream infections in hemodialysis patients

    Directory of Open Access Journals (Sweden)

    Brunelli SM

    2014-04-01

    Full Text Available Steven M Brunelli,1 Levi Njord,2 Abigail E Hunt,1 Scott P Sibbel1 1DaVita Clinical Research®, Minneapolis, MN, USA; 2DaVita HealthCare Partners, Inc, Denver, CO, USA Background and objectives: Catheter-related bloodstream infections (CRBSIs are common in hemodialysis patients using central venous catheters, and catheter occlusion also occurs frequently. The Tego needlefree connector was developed to reduce the incidence of these complications; however, existing studies of its effectiveness and safety are limited. Materials and methods: This retrospective analysis compared outcomes among patients of a large dialysis organization receiving in-center hemodialysis using a central venous catheter with either the Tego connector or standard catheter caps between October 1 and June 30, 2013. Incidence rates for intravenous (IV antibiotic starts, receipt of an IV antibiotic course, positive blood cultures, mortality, and missed dialysis treatments were calculated, and incidence-rate ratios (IRRs were estimated using Poisson regression models. Utilization of erythropoiesis-stimulating agents (ESAs and thrombolytics was described for each patient-month and compared using mixed linear models. Models were run without adjustment, adjusted for covariates that were imbalanced between cohorts, or fully adjusted for all potential confounders. Results: The analysis comprised 10,652 Tego patients and 6,493 controls. Tego use was independently associated with decreased risk of CRBSI, defined by initiation of IV antibiotics (adjusted IRR 0.92, 95% confidence interval [CI] 0.87–0.97 or initiation of IV antibiotic course (adjusted IRR 0.89, 95% CI 0.84–0.95. Tego use was independently associated with decreased rate of missed dialysis treatments (adjusted IRR 0.98, 95% CI 0.97–1.00; no significant difference between Tego and control cohorts was observed with respect to mortality. Tego use was associated with decreased likelihood of thrombolytic use (adjusted per

  14. Characterization and Clinical Impact of Bloodstream Infection Caused by Carbapenemase-Producing Enterobacteriaceae in Seven Latin American Countries

    Science.gov (United States)

    Villegas, Maria Virginia; Pallares, Christian J.; Hernández-Gómez, Cristhian; Correa, Adriana; Álvarez, Carlos; Rosso, Fernando; Matta, Lorena; Luna, Carlos; Zurita, Jeannete; Mejía-Villatoro, Carlos; Rodríguez-Noriega, Eduardo; Seas, Carlos; Cortesía, Manuel; Guzmán-Suárez, Alfonso; Guzmán-Blanco, Manuel

    2016-01-01

    Introduction Infections caused by carbapenem-resistant Enterobacteriaceae are a public health problem associated with higher mortality rates, longer hospitalization and increased healthcare costs. We carried out a study to describe the characteristics of patients with carbapenemase-producing Enterobacteriaceae (CPE) and non-CPE bloodstream infection (BSI) from Latin American hospitals and to determine the clinical impact in terms of mortality and antibiotic therapy. Methods Between July 2013 and November 2014, we conducted a multicenter observational study in 11 hospitals from 7 Latin American countries (Argentina, Colombia, Ecuador, Guatemala, Mexico, Peru, Venezuela). Patients with BSI caused by Enterobacteriaceae were included and classified either as CPE or non-CPE based on detection of blaKPC, blaVIM, blaIMP, blaNDM and blaOXA-48 by polymerase chain reaction. Enrolled subjects were followed until discharge or death. Demographic, microbiological and clinical characteristics were collected from medical records. Both descriptive and inferential statistics were used to analyze the information. Results A total of 255 patients with Enterobacteriaceae BSI were included; CPE were identified in 53 of them. In vitro non-susceptibility to all screened antibiotics was higher in the patients with CPE BSI, remaining colistin, tigecycline and amikacin as the most active drugs. Combination therapy was significantly more frequent in the CPE BSI group (p < 0.001). The most common regimen was carbapenem + colistin or polymyxin B. The overall mortality was 37% (94/255). Overall and attributable mortality were significantly higher in patients with CPE BSI (p < 0.001); however, we found that patients with CPE BSI who received combination therapy and those who received monotherapy had similar mortality. After multivariate adjustment, CPE BSI (adjusted odds ratio [aOR] 4; 95% confidence interval [CI] 1.7–9.5; p = 0.002) and critical illness (aOR 6.5; 95% CI 3.1–13.7; p < 0

  15. Geobacteraceae strains and methods

    Science.gov (United States)

    Lovley, Derek R.; Nevin, Kelly P.; Yi, Hana

    2015-07-07

    Embodiments of the present invention provide a method of producing genetically modified strains of electricigenic microbes that are specifically adapted for the production of electrical current in microbial fuel cells, as well as strains produced by such methods and fuel cells using such strains. In preferred embodiments, the present invention provides genetically modified strains of Geobacter sulfurreducens and methods of using such strains.

  16. Gendered Responses to Serious Strain: The Argument for a General Strain Theory of Deviance

    OpenAIRE

    Kaufman, Joanne M.

    2009-01-01

    This paper expands and builds on newer avenues in research on gender and general strain theory (GST). I accomplish this by focusing on serious strains that are relevant for males and females, including externalizing and internalizing forms of negative emotions, and including multiple gendered deviant outcomes. Using the Add Health dataset, I find strong support for the impact of serious strains on both types of negative emotions and different forms of deviance for males and females. However, ...

  17. Muscle strain (image)

    Science.gov (United States)

    A muscle strain is the stretching or tearing of muscle fibers. A muscle strain can be caused by sports, exercise, a ... something that is too heavy. Symptoms of a muscle strain include pain, tightness, swelling, tenderness, and the ...

  18. Muscle strain treatment

    Science.gov (United States)

    Treatment - muscle strain ... Question: How do you treat a muscle strain ? Answer: Rest the strained muscle and apply ice for the first few days after the injury. Anti-inflammatory medicines or acetaminophen ( ...

  19. Two-Dimensional Laser-Speckle Surface-Strain Gauge

    Science.gov (United States)

    Barranger, John P.; Lant, Christian

    1992-01-01

    Extension of Yamaguchi's laser-speckle surface-strain-gauge method yields data on two-dimensional surface strains in times as short as fractions of second. Laser beams probe rough spot on surface of specimen before and after processing. Changes in speckle pattern of laser light reflected from spot indicative of changes in surface strains during processing. Used to monitor strains and changes in strains induced by hot-forming and subsequent cooling of steel.

  20. Strain analysis of nonlocal viscoelastic Kelvin bar in tension

    Institute of Scientific and Technical Information of China (English)

    ZHAO Xue-chuan; LEI Yong-jun; ZHOU Jian-ping

    2008-01-01

    Based on viscoelastic Kelvin model and nonlocal relationship of strain and stress, a nonlocal constitutive relationship of viscoelasticity is obtained and the strain response of a bar in tension is studied. By transforming governing equation of the strain analysis into Volterra integration form and by choosing a symmetric exponential form of kernel function and adapting Neumann series, the closed-form solution of strain field of the bar is obtained. The creep process of the bar is presented. When time approaches infinite, the strain of bar is equal to the one of nonlocal elasticity.

  1. Long-term, low-dose tigecycline to treat relapsing bloodstream infection due to KPC-producing Klebsiella pneumoniae after major hepatic surgery

    Directory of Open Access Journals (Sweden)

    Luca Morelli

    2015-07-01

    Full Text Available A 68-year-old male underwent a right hepatectomy, resection of the biliary convergence, and a left hepatic jejunostomy for a Klatskin tumour. The postoperative course was complicated by biliary abscesses with relapsing bloodstream infections due to Klebsiella pneumoniae carbapenemase (KPC-producing Klebsiella pneumoniae (KPC-Kp. A 2-week course of combination antibiotic therapy failed to provide source control and the bacteraemia relapsed. Success was obtained with a regimen of tigecycline 100 mg daily for 2 months, followed by tigecycline 50 mg daily for 6 months, then 50 mg every 48 h for 3 months. No side effects were reported.

  2. Editorial on low-dose acetylsalicylic acid treatment and impact on short-term mortality in Staphylococcus aureus bloodstream infection: a propensity score-matched cohort study.

    Science.gov (United States)

    Schoergenhofer, Christian; Schwameis, Michael; Lagler, Heimo; Jilma, Bernd

    2016-05-01

    The manuscript "Low-Dose Acetylsalicylic Acid Treatment and Impact on Short-Term Mortality in Staphylococcus aureus (S. aureus) Bloodstream Infection: A propensity Score-Matched Cohort Study" published in Critical Care Medicine by Osthoff et al. reported an association of aspirin intake with a reduced short-term mortality. Direct anti-microbial effects of aspirin and its metabolite salicylate were suggested in preclinical studies. Especially intriguing is the inclusion of a control group with Escherichia coli (E. coli) blood stream infections in this study, in which aspirin was not associated with an improved outcome. However, as other observational studies also reported benefits of aspirin in critically ill patients, randomized trials are needed to confirm the effects of low-dose aspirin. PMID:27294095

  3. Program Calibrates Strain Gauges

    Science.gov (United States)

    Okazaki, Gary D.

    1991-01-01

    Program dramatically reduces personnel and time requirements for acceptance tests of hardware. Data-acquisition system reads output from Wheatstone full-bridge strain-gauge circuit and calculates strain by use of shunt calibration technique. Program nearly instantaneously tabulates and plots strain data against load-cell outputs. Modified to acquire strain data for other specimens wherever full-bridge strain-gauge circuits used. Written in HP BASIC.

  4. Bloodstream infections in children with cancer: a multicentre surveillance study of the Italian Association of Paediatric Haematology and Oncology. Supportive Therapy Group-Infectious Diseases Section.

    Science.gov (United States)

    Viscoli, C; Castagnola, E; Giacchino, M; Cesáro, S; Properzi, E; Tucci, F; Mura, R M; Alvisi, P; Zanazzo, G; Surico, G; Bonetti, F; De Sio, L; Izzi, G; Di Cataldo, A; Ziino, O; Massolo, F; Nardi, M; Santoro, N; Binda, S

    1999-05-01

    A one-year prospective, multicentre surveillance study on aetiology, main clinical features and outcome of bloodstream infections in children with cancer was conducted in 18 paediatric haematology centres belonging to the Italian Association for Paediatric Haematology and Oncology. A total of 191 bloodstream infections were reported during the study period. Of them, 123 (64%) occurred in neutropenic and 68 (36%) in non-neutropenic patients. Gram-positive cocci caused 45% (85/191) of the episodes, gram-negative rods 41% (78/191), and fungi 9% (18/191). The remaining 5% (10/191) of the episodes were poly-microbial infections. A total of 204 pathogens were isolated (46% gram-positive cocci; 44% gram-negative rods; and 10% fungi). The aetiologic distribution was similar among neutropenic and non-neutropenic patients. A correlation between the infection and the presence of an indwelling central venous catheter was found in 20% (23/114) of the episodes among neutropenic patients and in 55% (23/62) among non-neutropenic patients. Gram-negative micro-organisms were isolated in an unusually high proportion of catheter-related infections (48%). The overall mortality rate from any cause within 30 days from the first positive blood culture was 11%, and was higher among patients who were neutropenic at the onset of the infection than among those who were not neutropenic (15 versus 4%, P = 0.03). In addition, the mortality was significantly higher in recipients of bone marrow transplantation than in patients with acute leukaemia or solid tumour (21, 11 and 6%, respectively) and was also higher in fungaemias and poly-microbial infections (22 and 30%) than in single gram-positive and gram-negative bacteraemias (11 and 6%). PMID:10505037

  5. Strains and Sprains

    Science.gov (United States)

    ... ON THIS TOPIC Sports Medicine Center Preventing Children's Sports Injuries Computer-Related Repetitive Stress Injuries Knee Injuries Broken ... Knee Injuries Sports and Exercise Safety Dealing With Sports Injuries Groin Strain Ankle Sprains Strains and Sprains Stretching ...

  6. Electronic Transport in Strained Graphene

    OpenAIRE

    Aguilera, Juan Luis

    2015-01-01

    Graphene is a single atomic layer material with exceptional electronic and mechanical properties. Graphene has formed the basis of many nanoelectromechanical and strain sensing devices. However, the ultimate limit of miniaturization of such sensors has not yet been ascertained. In this work we present the fabrication and electrical characterization of nanoscale pressure sensors realized from suspended graphene membrane devices.We start in chapter 1 by describing the elemental electronic prope...

  7. Validation of perceptual strain index to evaluate the thermal strain in experimental hot conditions

    Directory of Open Access Journals (Sweden)

    Habibollah Dehghan

    2015-01-01

    Conclusions: The research findings showed when there is no access to other forms of methods to evaluate the heat stress, it can be used the PeSI in evaluating the strain because of its favorable correlation with the thermal strain.

  8. Strained Silicon Photonics

    OpenAIRE

    Wehrspohn, Ralf B; Jörg Schilling; Christian Bohley; Clemens Schriever

    2012-01-01

    A review of recent progress in the field of strained silicon photonics is presented. The application of strain to waveguide and photonic crystal structures can be used to alter the linear and nonlinear optical properties of these devices. Here, methods for the fabrication of strained devices are summarized and recent examples of linear and nonlinear optical devices are discussed. Furthermore, the relation between strain and the enhancement of the second order nonlinear susceptibility is inves...

  9. Hot forming recrystallization kinetics in steel

    Directory of Open Access Journals (Sweden)

    J. Kliber

    2010-01-01

    Full Text Available The theory of kinetics of static recrystallization of steel during hot forming links the phenomenon to certain critical strain, grain size, strain rate, activation energy and temperature. The basic description is provided by the Avrami equation. An overview of equations used was compiled and comments on selected parameters prepared.

  10. Hot forming recrystallization kinetics in steel

    OpenAIRE

    J. Kliber; Fabík, R.; Vitez, I.; Drozd, K.

    2010-01-01

    The theory of kinetics of static recrystallization of steel during hot forming links the phenomenon to certain critical strain, grain size, strain rate, activation energy and temperature. The basic description is provided by the Avrami equation. An overview of equations used was compiled and comments on selected parameters prepared.

  11. Form Matters

    OpenAIRE

    Hedegaard Larsen, Morten

    2010-01-01

    This thesis investigates the reasons for our (in the Western World) preference for shopping (for food) in supermarkets? What social and performative historical developments might explain this preference? And what are the consequences of this preference? Historical descriptions of the performativity of the food market from the first Agora’s to the supermarkets of the 21st century as well as from theatre’s and Western performance spaces will form the comparative analytical basis, together wi...

  12. EDIN-B Promotes the Translocation of Staphylococcus aureus to the Bloodstream in the Course of Pneumonia

    Directory of Open Access Journals (Sweden)

    Johan Courjon

    2015-10-01

    Full Text Available It is crucial to define risk factors that contribute to host invasion by Staphylococcus aureus. Here, we demonstrate that the chromosomally encoded EDIN-B isoform from S. aureus contributes to the onset of bacteremia during the course of pneumonia. Deletion of edinB in a European lineage community-acquired methicillin resistant S. aureus (CA-MRSA strain (ST80-MRSA-IV dramatically decreased the frequency and magnitude of bacteremia in mice suffering from pneumonia. This deletion had no effect on the bacterial burden in both blood circulation and lung tissues. Re-expression of wild-type EDIN-B, unlike the catalytically inactive mutant EDIN-R185E, restored the invasive characteristics of ST80-MRSA-IV.

  13. Design parameters for borehole strain instrumentation

    Science.gov (United States)

    Gladwin, Michael T.; Hart, Rhodes

    1985-01-01

    The response of a borehole strain meter to hydrostatic and shear deformations in an isotropic medium is calculated to facilitate optimum instrument design and produce instrument response factors for parameters typically encountered in installed instruments. Results for an empty borehole are first compared with results for an instrument in intimate contact with the surrounding rock. The effects of the grout used to install the instrument are then examined. Where possible, analytic forms for the response factors are given. Results for typical installations are then presented in graphical form for optimizing instrument design in an environment of known elastic parameters. Alternatively, the results may be applied in the measurement of unknown strain signals, to correct for instrument response or to provide in-situ estimates of the elastic properties of the environment by examination of observed strain response to known strain signals.

  14. Automorphic Forms

    DEFF Research Database (Denmark)

    von Essen, Flemming Brændgaard

    Hecke characters in the points 4 and 6. It is well known, that all zeros of the Eisenstein series Ek wrt. SL2(Z) in the standard fundamental domain has modulus 1. We show that this is also true for #n Ek, where # is a certain differential operator. We then proceed to study logarithms of multiplier...... systems. For automorphic forms wrt. Hecke triangle groups and Fuchsian groups with no elliptic elements and genus 0, we show that some logarithms of multiplier systems can be interpreted as a linking number. Finally we show a "twisted" version of the prime geodesics theorem, and logarithms of multiplier...

  15. Superplastic forming simulation of RF detector foils

    OpenAIRE

    Snippe, Q.H.C.; Meinders, V.T.; Boogaard, van den, A.H.

    2009-01-01

    Complex-shaped sheet products, such as R(adio) F(requency) shieldings sheets, used in a subatomic particle detector, can be manufactured by superplastic forming. To predict whether a formed sheet is resistant against gas leakage, FE simulations are used, involving a user-defined material model. This model incorporates an initial flow stress, including strain rate hardening. It also involves strain hardening and softening, the latter because of void formation and growth inside the material. Al...

  16. Framework for Concentrated Strain Deployable Trusses

    OpenAIRE

    Mejia-Ariza, Juan Manuel

    2008-01-01

    This research presents a simplified framework for the analysis of deployable trusses using the concentrated strain approach and uses it to provide key insights into the many design decisions to be made in the development of concentrated strain architectures. The framework uses Euler Column Theory to derive closed form solutions to estimate truss performance. The results are compared to a classical solution and shown to give similar results. A range of strut and hinge hierarchy choices are con...

  17. Strains in pyrolytic graphite under irradiation

    International Nuclear Information System (INIS)

    The studies of strains in pyrolytic graphite caused by development of amorphization in the irradiation zone showed that the local strains attain tens of percent; their distribution is inhomogeneous both in magnitude and in sign. The tendency toward formation of a biaxial field of compressive strains becomes marked with an increase in the fluence, although the formation of small regions in the form of narrow sectors within whose boundaries compression is observed in the radial direction and extension is observed in the tangential direction is also possible. 14 refs., 6 figs

  18. Procalcitonin and procalcitonin kinetics for diagnosis and prognosis of intravascular catheter-related bloodstream infections in selected critically ill patients: a prospective observational study

    Directory of Open Access Journals (Sweden)

    Theodorou Vasiliki P

    2012-10-01

    Full Text Available Abstract Background Procalcitonin (PCT has emerged as a valuable marker of sepsis. The potential role of PCT in diagnosis and therapy monitoring of intravascular catheter-related bloodstream infections (CRBSI in intensive care unit (ICU is still unclear and was evaluated. Methods Forty-six patients were included in the study, provided they were free of infection upon admission and presented the first episode of suspected CRBSI during their ICU stay. Patients who had developed any other infection were excluded. PCT was measured daily during the ICU hospitalization. Primary endpoint was proven CRBSI. Therapy monitoring as according to infection control was also evaluated. Results Among the 46 patients, 26 were diagnosed with CRBSI. Median PCT on the day of infection suspicion (D0 was 7.70 and 0.10 ng/ml for patients with and without proven CRBSI, respectively (p 0.20 ng/ml of PCT between the D0 and any of the 4 preceding days was associated with a positive predictive value exceeding 96%. PCT concentrations from the D2 to D6 after suspected infection tended to decrease in controlled patients, whereas remained stable in non-controlled subjects. A PCT concentration exceeding 1.5 ng/ml during D3 was associated with lack of responsiveness to therapy (p = 0.028. Conclusions We suggest that PCT could be a helpful diagnostic and prognostic marker of CRBSI in critically ill patients. Both absolute values and variations should be considered.

  19. Diffraction tomography of strain

    OpenAIRE

    Lionheart, W R B; Withers, P. J.

    2015-01-01

    We consider whether it is possible to recover the three dimensional strain field tomographically from neutron and x-ray diffraction data for polycrystalline materials. We show that the distribution of strain transverse to a ray cannot be deduced from one diffraction pattern accumulated along that path, but that a certain moment of that data corresponds to the transverse ray transform of the strain tensor and so may be recovered by inverting that transform given sufficient data. We show that t...

  20. Strained Silicon Photonics

    Directory of Open Access Journals (Sweden)

    Ralf B. Wehrspohn

    2012-05-01

    Full Text Available A review of recent progress in the field of strained silicon photonics is presented. The application of strain to waveguide and photonic crystal structures can be used to alter the linear and nonlinear optical properties of these devices. Here, methods for the fabrication of strained devices are summarized and recent examples of linear and nonlinear optical devices are discussed. Furthermore, the relation between strain and the enhancement of the second order nonlinear susceptibility is investigated, which may enable the construction of optically active photonic devices made of silicon.

  1. Strain-engineered MOSFETs

    CERN Document Server

    Maiti, CK

    2012-01-01

    Currently strain engineering is the main technique used to enhance the performance of advanced silicon-based metal-oxide-semiconductor field-effect transistors (MOSFETs). Written from an engineering application standpoint, Strain-Engineered MOSFETs introduces promising strain techniques to fabricate strain-engineered MOSFETs and to methods to assess the applications of these techniques. The book provides the background and physical insight needed to understand new and future developments in the modeling and design of n- and p-MOSFETs at nanoscale. This book focuses on recent developments in st

  2. Comparative Analysis of the Orphan CRISPR2 Locus in 242 Enterococcus faecalis Strains.

    Directory of Open Access Journals (Sweden)

    Karthik Hullahalli

    Full Text Available Clustered, Regularly Interspaced Short Palindromic Repeats and their associated Cas proteins (CRISPR-Cas provide prokaryotes with a mechanism for defense against mobile genetic elements (MGEs. A CRISPR locus is a molecular memory of MGE encounters. It contains an array of short sequences, called spacers, that generally have sequence identity to MGEs. Three different CRISPR loci have been identified among strains of the opportunistic pathogen Enterococcus faecalis. CRISPR1 and CRISPR3 are associated with the cas genes necessary for blocking MGEs, but these loci are present in only a subset of E. faecalis strains. The orphan CRISPR2 lacks cas genes and is ubiquitous in E. faecalis, although its spacer content varies from strain to strain. Because CRISPR2 is a variable locus occurring in all E. faecalis, comparative analysis of CRISPR2 sequences may provide information about the clonality of E. faecalis strains. We examined CRISPR2 sequences from 228 E. faecalis genomes in relationship to subspecies phylogenetic lineages (sequence types; STs determined by multilocus sequence typing (MLST, and to a genome phylogeny generated for a representative 71 genomes. We found that specific CRISPR2 sequences are associated with specific STs and with specific branches on the genome tree. To explore possible applications of CRISPR2 analysis, we evaluated 14 E. faecalis bloodstream isolates using CRISPR2 analysis and MLST. CRISPR2 analysis identified two groups of clonal strains among the 14 isolates, an assessment that was confirmed by MLST. CRISPR2 analysis was also used to accurately predict the ST of a subset of isolates. We conclude that CRISPR2 analysis, while not a replacement for MLST, is an inexpensive method to assess clonality among E. faecalis isolates, and can be used in conjunction with MLST to identify recombination events occurring between STs.

  3. Biofilm formation by asymptomatic and virulent urinary tract infectious Escherichia coli strains

    DEFF Research Database (Denmark)

    Hancock, Viktoria; Ferrieres, Lionel; Klemm, Per

    2007-01-01

    have investigated the biofilm-forming capacity on abiotic surfaces of groups of ABU strains and UPEC strains in human urine. We found that there is a strong bias; ABU strains were significantly better biofilm formers than UPEC strains. Our data suggest that biofilm formation in urinary tract infectious...

  4. Highly Strained Organophosphorus Compounds

    NARCIS (Netherlands)

    Slootweg, J.C.

    2005-01-01

    In our research on small, strained organophosphorus ring systems we became interested in the synthesis and applications of species that are even more strained than the parent phosphirane, by introducing an exocyclic double bond (methylenephosphirane), and by cyclopropyl spirofusion to the edge (e.g

  5. The influence of strain rate and hydrogen on the plane-strain ductility of Zircaloy cladding

    Energy Technology Data Exchange (ETDEWEB)

    Link, T.M.; Motta, A.T.; Koss, D.A. [Pennsylvania State Univ., University Park, PA (United States)

    1998-03-01

    The authors studied the ductility of unirradiated Zircaloy-4 cladding under loading conditions prototypical of those found in reactivity-initiated accidents (RIA), i.e.: near plane-strain deformation in the hoop direction (transverse to the cladding axis) at room temperature and 300 C and high strain rates. To conduct these studies, they developed a specimen configuration in which near plane-strain deformation is achieved in the gage section, and a testing methodology that allows one to determine both the limit strain at the onset of localized necking and the fracture strain. The experiments indicate that there is little effect of strain rate (10{sup {minus}3} to 10{sup 2} s{sup {minus}1}) on the ductility of unhydrided Zircaloy tubing deformed under near plane-strain conditions at either room temperature or 300 C. Preliminary experiments on cladding containing 190 ppm hydrogen show only a small loss of fracture strain but no clear effect on limit strain. The experiments also indicate that there is a significant loss of Zircaloy ductility when surface flaws are present in the form of thickness imperfections.

  6. Superplastic forming of ceramic insulation

    Science.gov (United States)

    Nieh, T. G.; Wittenauer, J. P.; Wadsworth, J.

    1992-01-01

    Superplasticity has been demonstrated in many fine-grained structural ceramics and ceramic composites, including yttria-stabilized tetragonal zirconia polycrystal (YTZP), alumina, and Al2O3-reinforced zirconia (Al2O3/YTZ) duplex composites and SiC-reinforced Si3N4. These superplastic ceramics obviously offer the potential benefit of forming net shape or near net shape parts. This could be particularly useful for forming complicated shapes that are difficult to achieve using conventional forming techniques, or require elaborate, subsequent machining. In the present study, we successfully demonstrated the following: (1) superplastic 3Y-TXP and 20 percent Al2O3/YTZ composite have for the first time been successfully deformed into hemispherical caps via a biaxial gas-pressure forming technique; (2) no experimental difficulty was encountered in applying the required gas pressures and temperatures to achieve the results, thus, it is certain that higher rates of deformation than those presented in this study will be possible by using the current test apparatus at higher temperatures and pressures; and (3) an analytical model incorporating material parameters, such as variations during forming in the strain rate sensitivity exponent and grain growth-induced strain hardening, is needed to model accurately and therefore precisely control the biaxial gas-pressure forming of superplastic ceramics. Based on the results of this study, we propose to fabricate zirconia insulation tubes by superplastic extrusion of zirconia polycrystal. This would not only reduce the cost, but also improve the reliability of the tube products.

  7. Effect of dynamic strain rate on micro-indentation properties of pure aluminum

    Directory of Open Access Journals (Sweden)

    Yamada Hiroyuki

    2015-01-01

    Full Text Available Indentation is widely used to investigate the elastic and plastic properties of mechanical materials, which includes the strain rate sensitivity. The indentation exhibits an inhomogeneous strain distribution in contrast to compression and tensile tests with homogeneous deformation. Thus, the strain rate of the indentation may form the inhomogeneous distribution. Therefore, the effect of strain rate distribution of the indentation on pure aluminum with respect to the strain rate dependence of strength in order to clarify the effect of the strain rate on the indentation technique. First, the numerical simulation was established using the Cowper-Symonds equation as the dynamic constitutive equation. Secondary, the strain rate distribution was calculated from the equivalent plastic strain distribution. The strain rate distribution was quite different from the strain distribution, which showed that the strain rate at the crater rim was higher than that beneath the indenter. Finally, we try to perform the averaging of strain rate distribution in order to make an index of strain rate in the indentation. The average of strain rate distribution was calculated using the equivalent plastic strain above a boundary value that is the critical strain and the representative strain. There is correlation between the average strain rate and the loading curvature, which shows that the average strain rate can express as the representative of strain rate for the indentation technique.

  8. Rate and time to develop first central line-associated bloodstream infections when comparing open and closed infusion containers in a Brazilian Hospital

    Directory of Open Access Journals (Sweden)

    Margarete Vilins

    2009-10-01

    Full Text Available The objective of the study was to determine the effect of switching from an open (glass or semi-rigid plastic infusion container to a closed, fully collapsible plastic infusion container (Viaflex® on rate and time to onset of central lineassociated bloodstream infections (CLABSI. An open-label, prospective cohort, active healthcare-associated infection surveillance, sequential study was conducted in three intensive care units in Brazil. The CLABSI rate using open infusion containers was compared to the rate using a closed infusion container. Probability of acquiring CLABSI was assessed over time and compared between open and closed infusion container periods; three-day intervals were examined. A total of 1125 adult ICU patients were enrolled. CLABSI rate was significantly higher during the open compared with the closed infusion container period (6.5 versus 3.2 CLABSI/1000 CL days; RR=0.49, 95%CI=0.26- 0.95, p=0.031. During the closed infusion container period, the probability of acquiring a CLABSI remained relatively constant along the time of central line use (0.8% Days 2-4 to 0.7% Days 11-13 but increased in the open infusion container period (1.5% Days 2-4 to 2.3% Days 11-13. Combined across all time intervals, the chance of a patient acquiring a CLABSI was significantly lower (55% in the closed infusion container period (Cox proportional hazard ratio 0.45, p= 0.019. CLABSIs can be reduced with the use of full barrier precautions, education, and performance feedback. Our results show that switching from an open to a closed infusion container may further reduce CLABSI rate as well as delay the onset of CLABSIs. Closed infusion containers significantly reduced CLABSI rate and the probability of acquiring CLABSI.

  9. A Central Line Care Maintenance Bundle for the Prevention of Central Line-Associated Bloodstream Infection in Non-Intensive Care Unit Settings.

    Science.gov (United States)

    O'Neil, Caroline; Ball, Kelly; Wood, Helen; McMullen, Kathleen; Kremer, Pamala; Jafarzadeh, S Reza; Fraser, Victoria; Warren, David

    2016-06-01

    OBJECTIVE To evaluate a central line care maintenance bundle to reduce central line-associated bloodstream infection (CLABSI) in non-intensive care unit settings. DESIGN Before-after trial with 12-month follow-up period. SETTING A 1,250-bed teaching hospital. PARTICIPANTS Patients with central lines on 8 general medicine wards. Four wards received the intervention and 4 served as controls. INTERVENTION A multifaceted catheter care maintenance bundle consisting of educational programs for nurses, update of hospital policies, visual aids, a competency assessment, process monitoring, regular progress reports, and consolidation of supplies necessary for catheter maintenance. RESULTS Data were collected for 25,542 catheter-days including 43 CLABSI (rate, 1.68 per 1,000 catheter-days) and 4,012 catheter dressing observations. Following the intervention, a 2.5% monthly decrease in the CLABSI incidence density was observed on intervention floors but this was not statistically significant (95% CI, -5.3% to 0.4%). On control floors, there was a smaller but marginally significant decrease in CLABSI incidence during the study (change in monthly rate, -1.1%; 95% CI, -2.1% to -0.1%). Implementation of the bundle was associated with improvement in catheter dressing compliance on intervention wards (78.8% compliance before intervention vs 87.9% during intervention/follow-up; Pcontrol wards (84.9% compliance before intervention vs 90.9% during intervention/follow-up; P=.001). CONCLUSIONS A multifaceted program to improve catheter care was associated with improvement in catheter dressing care but no change in CLABSI rates. Additional study is needed to determine strategies to prevent CLABSI in non-intensive care unit patients. Infect Control Hosp Epidemiol 2016;37:692-698. PMID:26999746

  10. Significance of mannose-binding lectin deficiency and nucleotide-binding oligomerization domain 2 polymorphisms in Staphylococcus aureus bloodstream infections: a case-control study.

    Directory of Open Access Journals (Sweden)

    Michael Osthoff

    Full Text Available BACKGROUND: Pathways coordinated by innate pattern recognition receptors like mannose-binding lectin (MBL and nucleotide-binding oligomerization domain 2 (NOD2 are among the first immune responses to Staphylococcus aureus (S. aureus bloodstream infections (BSI in animal models, but human data are limited. Here, we investigated the role of MBL deficiency and NOD2 mutations in the predisposition to and severity of S. aureus BSI. PATIENTS AND METHODS: A matched case-control study was undertaken involving 70 patients with S. aureus BSI and 70 age- and sex-matched hospitalized controls. MBL levels, MBL2 and NOD2 polymorphisms were analyzed. RESULTS: After adjusting for potential confounders, MBL deficiency (<0.5 µg/ml was found less frequently in cases than controls (26 vs. 41%, OR 0.4, 95% confidence interval (CI 0.20-0.95, p=0.04 as were low producing MBL genotypes (11 vs. 23%, OR 0.2, 95% CI 0.08-0.75, p=0.01, whereas NOD2 polymorphisms were similarly distributed. Cases with NOD2 polymorphisms had less organ dysfunction as shown by a lower SOFA score (median 2.5 vs. 4.5, p=0.02, whereas only severe MBL deficiency (<0.1 µg/ml was associated with life-threatening S. aureus BSI (OR 5.6, 95% CI 1.25-24.85, p=0.02. CONCLUSIONS: Contrary to animal model data, our study suggests MBL deficiency may confer protection against acquiring S. aureus BSI. NOD2 mutations were less frequently associated with multi-organ dysfunction. Further human studies of the innate immune response in S. aureus BSI are needed to identify suitable host targets in sepsis treatment.

  11. Predictors of mortality in patients with bloodstream infections caused by KPC-producing Klebsiella pneumoniae and impact of appropriate antimicrobial treatment.

    Science.gov (United States)

    Zarkotou, O; Pournaras, S; Tselioti, P; Dragoumanos, V; Pitiriga, V; Ranellou, K; Prekates, A; Themeli-Digalaki, K; Tsakris, A

    2011-12-01

    Bloodstream infections (BSIs) caused by Klebsiella pneumoniae carbapenemases (KPC)-producing K. pneumoniae (KPC-KP) are associated with high mortality rates. We investigated outcomes, risk factors for mortality and impact of appropriate antimicrobial treatment in patients with BSIs caused by molecularly confirmed KPC-KP. All consecutive patients with KPC-KP BSIs between May 2008 and May 2010 were included in the study and followed-up until their discharge or death. Potential risk factors for infection mortality were examined by a case-control study. Case-patients were those who died from the BSI and control-patients those who survived. Appropriate antimicrobial therapy was defined as treatment with in vitro active antimicrobials for at least 48 h. A total of 53 patients were identified. Overall mortality was 52.8% and infection mortality was 34%. Appropriate antimicrobial therapy was administered to 35 patients; mortality due to infection occurred in 20%. All 20 patients that received combination schemes had favourable infection outcome; in contrast, seven of 15 patients given appropriate monotherapy died (p 0.001). In univariate analysis, risk factors for mortality were age (p infection onset (p appropriate antimicrobial treatment (p 0.003), combinations of active antimicrobials (p 0.001), catheter-related bacteraemia (p 0.04), prior surgery (p 0.014) and other therapeutic interventions (p 0.015) were significantly associated with survival. Independent predictors of mortality were age, APACHE II score at infection onset and inappropriate antimicrobial treatment. Among them, appropriate treatment is the only modifiable independent predictor of infection outcome. PMID:21595793

  12. Clinical impact of antimicrobial resistance in European hospitals: excess mortality and length of hospital stay related to methicillin-resistant Staphylococcus aureus bloodstream infections.

    LENUS (Irish Health Repository)

    de Kraker, Marlieke E A

    2011-04-01

    Antimicrobial resistance is threatening the successful management of nosocomial infections worldwide. Despite the therapeutic limitations imposed by methicillin-resistant Staphylococcus aureus (MRSA), its clinical impact is still debated. The objective of this study was to estimate the excess mortality and length of hospital stay (LOS) associated with MRSA bloodstream infections (BSI) in European hospitals. Between July 2007 and June 2008, a multicenter, prospective, parallel matched-cohort study was carried out in 13 tertiary care hospitals in as many European countries. Cohort I consisted of patients with MRSA BSI and cohort II of patients with methicillin-susceptible S. aureus (MSSA) BSI. The patients in both cohorts were matched for LOS prior to the onset of BSI with patients free of the respective BSI. Cohort I consisted of 248 MRSA patients and 453 controls and cohort II of 618 MSSA patients and 1,170 controls. Compared to the controls, MRSA patients had higher 30-day mortality (adjusted odds ratio [aOR] = 4.4) and higher hospital mortality (adjusted hazard ratio [aHR] = 3.5). Their excess LOS was 9.2 days. MSSA patients also had higher 30-day (aOR = 2.4) and hospital (aHR = 3.1) mortality and an excess LOS of 8.6 days. When the outcomes from the two cohorts were compared, an effect attributable to methicillin resistance was found for 30-day mortality (OR = 1.8; P = 0.04), but not for hospital mortality (HR = 1.1; P = 0.63) or LOS (difference = 0.6 days; P = 0.96). Irrespective of methicillin susceptibility, S. aureus BSI has a significant impact on morbidity and mortality. In addition, MRSA BSI leads to a fatal outcome more frequently than MSSA BSI. Infection control efforts in hospitals should aim to contain infections caused by both resistant and susceptible S. aureus.

  13. Comparison of colistin monotherapy and non-colistin combinations in the treatment of multi-drug resistant Acinetobacter spp. bloodstream infections: A Multicenter retrospective analysis

    Directory of Open Access Journals (Sweden)

    Ilker Inanc Balkan

    2015-01-01

    Full Text Available Objectives: To compare the efficacy of colistin (COL monotherapy versus non-COL based combinations in the treatment of bloodstream infections (BSIs due to multidrug resistant Acinetobacter spp.(MDR-A . Materials and Methods: Retrospective data of 107 MDR-A BSI cases from 27 tertiary centers in Turkey were included. Primary End-Point: 14-day mortality. Secondary End-Points: Microbial eradication and clinical improvement. Results: Thirty-six patients in the COL monotherapy (CM group and 71 in the non-COL based combinations (NCC group were included in the study. Mean age was 59.98 ± 20 years (range: 18-89 and 50.5% were male. Median duration of follow-up was 40 days (range: 9-297. The 14-day survival rates were 52.8% in CM and 47.23% in NCC group (P = 0.36. Microbiological eradication was achieved in 69% of CM and 83% of NCC group (P = 0.13. Treatment failure was detected in 22.9% of cases in both CM and NCC groups. Univariate analysis revealed that mean age (P = 0.001, Charlson comorbidity index (P = 0.03, duration of hospital stay before MDR-A BSI (P = 0.04, Pitt bacteremia score (P = 0.043 and Acute Physiology and Chronic Health Evaluation II score (P = 0.05 were significant in terms of 14-day mortality. Advanced age (P = 0.01 and duration of hospital stay before MDR-A BSI (P = 0.04 were independently associated with 14-day mortality in multivariate analysis. Conclusion: No significant difference was detected between CM and non-COL based combinations in the treatment of MDR-A BSIs in terms of efficacy and 14-day mortality.

  14. Implementation of central venous catheter bundle in an intensive care unit in Kuwait: Effect on central line-associated bloodstream infections.

    Science.gov (United States)

    Salama, Mona F; Jamal, Wafaa; Al Mousa, Haifa; Rotimi, Vincent

    2016-01-01

    Central line-associated bloodstream infection (CLABSIs) is an important healthcare-associated infection in the critical care units. It causes substantial morbidity, mortality and incurs high costs. The use of central venous line (CVL) insertion bundle has been shown to decrease the incidence of CLABSIs. Our aim was to study the impact of CVL insertion bundle on incidence of CLABSI and study the causative microbial agents in an intensive care unit in Kuwait. Surveillance for CLABSI was conducted by trained infection control team using National Health Safety Network (NHSN) case definitions and device days measurement methods. During the intervention period, nursing staff used central line care bundle consisting of (1) hand hygiene by inserter (2) maximal barrier precautions upon insertion by the physician inserting the catheter and sterile drape from head to toe to the patient (3) use of a 2% chlorohexidine gluconate (CHG) in 70% ethanol scrub for the insertion site (4) optimum catheter site selection. (5) Examination of the daily necessity of the central line. During the pre-intervention period, there were 5367 documented catheter-days and 80 CLABSIs, for an incidence density of 14.9 CLABSIs per 1000 catheter-days. After implementation of the interventions, there were 5052 catheter-days and 56 CLABSIs, for an incidence density of 11.08 per 1000 catheter-days. The reduction in the CLABSI/1000 catheter days was not statistically significant (P=0.0859). This study demonstrates that implementation of a central venous catheter post-insertion care bundle was associated with a reduction in CLABSI in an intensive care area setting. PMID:26138518

  15. Strain hardening and ductility of iron: axisymmetric vs. plane strain elongation. Technical progress report

    Energy Technology Data Exchange (ETDEWEB)

    Langford, G.

    1979-05-01

    The strain hardening of iron at high strains in plane strain elongation (strip drawing) is shown to fall increasngly below that of drawn iron wires at true strains above 2. This makes it unnecessary to invoke shear band formation simultaneously as a strengthening mechanism and as a ductility reducing mechanism in the drawn strip. Rather, shear bands may be a weakening mechanism in all contexts. A set of specimens of interstitial-free iron deformed in three of the four main classifications of deformation symmetry (wire, strip, and chips, representing axisymmetric elongation, plane strain elongation, and pure shear) has been prepared in the form of mechanical test specimens and thin foils for high resolution selected area diffraction. A simple technique for rapid discovery of the <110> axis of foils of strongly textured bcc wire has been worked out.

  16. Integrity of lipid nanocarriers in bloodstream and tumor quantified by near-infrared ratiometric FRET imaging in living mice.

    Science.gov (United States)

    Bouchaala, Redouane; Mercier, Luc; Andreiuk, Bohdan; Mély, Yves; Vandamme, Thierry; Anton, Nicolas; Goetz, Jacky G; Klymchenko, Andrey S

    2016-08-28

    Lipid nanocarriers are considered as promising candidates for drug delivery and cancer targeting because of their low toxicity, biodegradability and capacity to encapsulate drugs and/or contrasting agents. However, their biomedical applications are currently limited because of a poor understanding of their integrity in vivo. To address this problem, we report on fluorescent nano-emulsion droplets of 100nm size encapsulating lipophilic near-infrared cyanine 5.5 and 7.5 dyes with a help of bulky hydrophobic counterion tetraphenylborate. Excellent brightness and efficient Förster Resonance Energy Transfer (FRET) inside lipid NCs enabled for the first time quantitative fluorescence ratiometric imaging of NCs integrity directly in the blood circulation, liver and tumor xenografts of living mice using a whole-animal imaging set-up. This unique methodology revealed that the integrity of our FRET NCs in the blood circulation of healthy mice is preserved at 93% at 6h of post-administration, while it drops to 66% in the liver (half-life is 8.2h). Moreover, these NCs show fast and efficient accumulation in tumors, where they enter in nearly intact form (77% integrity at 2h) before losing their integrity to 40% at 6h (half-life is 4.4h). Thus, we propose a simple and robust methodology based on ratiometric FRET imaging in vivo to evaluate quantitatively nanocarrier integrity in small animals. We also demonstrate that nano-emulsion droplets are remarkably stable nano-objects that remain nearly intact in the blood circulation and release their content mainly after entering tumors. PMID:27327767

  17. Sprains and Strains

    Science.gov (United States)

    ... people at risk for strains. Gymnastics, tennis, rowing, golf, and other sports that require extensive gripping can ... Trials and You was designed to help people learn more about clinical trials, why they matter, and ...

  18. The strained state cosmology

    CERN Document Server

    Tartaglia, Angelo

    2015-01-01

    Starting from some relevant facts concerning the behaviour of the universe over large scale and time span, the analogy between the geometric approach of General Relativ- ity and the classical description of an elastic strained material continuum is discussed. Extending the elastic deformation approach to four dimensions it is shown that the accelerated expansion of the universe is recovered. The strain field of space-time repro- duces properties similar to the ones ascribed to the dark energy currently called in to explain the accelerated expansion. The strain field in the primordial universe behaves as radiation, but asymptotically it reproduces the cosmological constant. Subjecting the theory to a number of cosmological tests confirms the soundness of the approach and gives an optimal value for the one parameter of the model, i.e. the bulk modulus of the space-time continuum. Finally various aspects of the Strained State Cosmology (SSC) are discussed and contrasted with some non-linear massive gravity theor...

  19. Violent responses to strain: an examination of conditioning influences.

    Science.gov (United States)

    Mazerolle, P; Piquero, A

    1997-01-01

    Past research on General Strain Theory (GST) has not widely examined the application of the theory for understanding violent responses to strain. Additionally, the theory suggests there may be varying effects of strain on possible deviant outcomes across individuals differentiated on their dispositions toward deviance. In the current analysis, we examine violent responses to strain using original data collected from a sample of college-aged youth. Moreover, we specifically examine whether the effects of strain and anger on possible violent outcomes are invariant across individuals differentiated on their level of exposure to deviant peers and moral constraints against deviance. Using structural equation modeling, our results suggest that a composite measure of strain increases respondents' intentions to engage in assaultive behavior net of other predictors. Additionally, the results reveal that anger mediates the impact of strain on possible violent responses. Finally, the results of our subgroup analyses suggest that the basic form of the GST model is invariant across groups. PMID:9591352

  20. An Ultrasonic Strain Gauge

    OpenAIRE

    Kersemans, Mathias; Allaer, Klaas; Degrieck, Joris; Van Den Abeele, Koen; Pyl, Lincy; Zastavnik, Filip; Sol, Hugo; Van Paegem, Wim

    2014-01-01

    A method is introduced for the measurements of strain exploiting the interaction between ultrasound waves and characteristics of the insonified specimen. First, the response of obliquely incident harmonic waves to a deterministic surface roughness is utilized. Analysis of backscattered amplitudes in Bragg diffraction geometry then yields a measure for the in-plane strain field by mapping any shift in angular dependency. Secondly, the analysis of the reflection characteristics of normal incide...

  1. "Behaviour changes in Permethrin-resistant strain of Anopheles Stephensi "

    Directory of Open Access Journals (Sweden)

    Vatandoost H

    2000-09-01

    Full Text Available Behaviour studies indicated that the permethrin resistant strin of An. Stephensi was 3-fold resistant to knock-down compared with the susceptible strain. The resistant strain was however 3-fold less irritable to permethrin and less responsive than the susceptible strain to the movement of an aspirator. If reduced irritability and reduced responsiveness to catch are consequences of the changes in the nervous system, then such a form of resistance may be disadvantageous to mosquitoes in natural populations.

  2. Mixed multilayered vertical heterostructures utilizing strained monolayer WS2.

    OpenAIRE

    Sheng, Y.; Xu, W.; Wang, X.; He, Z.; Rong, Y.; Warner, JH

    2016-01-01

    Creating alternating layers of 2D materials forms vertical heterostructures with diverse electronic and opto-electronic properties. Monolayer WS2 grown by chemical vapour deposition can have inherent strain due to interactions with the substrate. The strain modifies the band structure and properties of monolayer WS2 and can be exploited in a wide range of applications. We demonstrate a non-aqueous transfer method for creating vertical stacks of mixed 2D layers containing a strained monolayer ...

  3. True Stress-True Strain Models for Structural Steel Elements

    OpenAIRE

    Arasaratnam, P.; K. S. Sivakumaran; Tait, M J

    2011-01-01

    A standard uniaxial tensile test, which establishes the engineering stress-strain relationship, in general, provides the basic mechanical properties of steel required by a structural designer. Modern numerical analysis techniques used for analysis of large strain problems such as failure analysis of steel structures and elements metal forming, metal cutting, and so forth, will require implementation and use of true stress-true strain material characterization. This paper establishes a five st...

  4. Reactions of strained hydrocarbons with alkene and alkyne metathesis catalysts.

    Science.gov (United States)

    Carnes, Matthew; Buccella, Daniela; Siegrist, Theo; Steigerwald, Michael L; Nuckolls, Colin

    2008-10-29

    Here we describe the metathesis reactions of a strained eight-membered ring that contains both alkene and alkyne functionality. We find that the alkyne metathesis catalyst produces polymer through a ring-opening alkyne metathesis reaction that is driven by the strain release from the monomer. The strained monomer provides unusual reactivity with ruthenium-based alkene metathesis catalysts. We isolate a discrete trimeric species a Dewar benzene derivative that is locked in this form through an unsaturated cyclophane strap. PMID:18826219

  5. Hot forming recrystallization kinetics in steel

    OpenAIRE

    Kliber, Jiří; Fabík, Richard; Vitez, Ivan; Drozd, Kamil

    2009-01-01

    The theory of kinetics of static recrystallization of steel during hot forming links the phenomenon to certain critical strain, grain size, strain rate, activation energy and temperature. The basic description is provided by the Avrami equation. An overview of equations used was compiled and comments on selected parameters prepared. Teorija kinetike statičke rekristalizacije čelika tijekom vrućeg oblikovanja ovu pojavu povezuje s kritičnom deformacijom, veličinom zrna, brzinom deform...

  6. Occurrence of Extended-Spectrum and AmpC Beta-Lactamases in Bloodstream Isolates of Klebsiella pneumoniae: Isolates Harbor Plasmid-Mediated FOX-5 and ACT-1 AmpC Beta-Lactamases

    OpenAIRE

    Coudron, Philip E.; Hanson, Nancy D.; Climo, Michael W.

    2003-01-01

    We tested 190 Klebsiella pneumoniae bloodstream isolates recovered from 189 patients in 30 U.S. hospitals in 23 states to determine the occurrence of extended-spectrum β-lactamase (ESBL) and AmpC β-lactamase producers. Based on growth inhibition by clavulanic acid by disk and MIC test methods, 18 (9.5%) of the isolates produced ESBLs. Although the disk diffusion method with standard breakpoints identified 28 cefoxitin-nonsusceptible isolates, only 5 (18%) of these were confirmed as AmpC produ...

  7. MEMS Graphene Strain Sensor

    Science.gov (United States)

    Young, Clinton Wen-Chieh

    Graphene is a two dimensional honeycomb structure of sp2 hybridized carbon atoms that has possibilities in many applications due to its excellent mechanical and electrical properties. One application for Graphene is in the field of sensors. Graphene's electronic properties do not degrade when it undergoes mechanical strain which is advantageous for strain sensors. In this thesis, certain properties, such as the piezo-resistivity and flexibility, of graphene will be explored to show how they can be utilized to make a strain sensing device. Our original fabrication process of patterning graphene and the transfer process of graphene onto a flexible substrate will be discussed. The development of a stretchable and flexible graphene based rosette strain sensor will also be detailed. Developing a novel, reliable patterning process for the graphene is the first step to manufacture a stretchable graphene based sensor. The graphene was patterned using a photolithography and etching process that was developed by our research team, then it was transferred to a flexible polymer substrate with the use of a combination of soft lithography and wet etching of the Ni foil with ferric chloride solution. Graphene patterning is an essential step in fabricating reliable and sensitive sensors. With this process, graphene can be consistently patterned into different shapes and sizes. To utilize the graphene as the sensing material it also needs to be transferred onto a flexible substrate. The innovative transfer process developed by our research team consistently adheres graphene to a flexible PDMS substrate while removing the original nickel substrate. In the end, the graphene was transferred from the metal substrate to the desired flexible substrate. This process was repeated multiple times to create a stack and multilayer device. While many graphene-based strain sensors have been developed, they are uni-directional and can only measure the strain applied on the sensor in a principle

  8. Strain Monitoring of Flexible Structures

    Science.gov (United States)

    Litteken, Douglas A.

    2017-01-01

    One of the biggest challenges facing NASA's deep space exploration goals is structural mass. A long duration transit vehicle on a journey to Mars, for example, requires a large internal volume for cargo, supplies and crew support. As with all space structures, a large pressure vessel is not enough. The vehicle also requires thermal, micro-meteoroid, and radiation protection, a navigation and control system, a propulsion system, and a power system, etc. As vehicles get larger, their associated systems also get larger and more complex. These vehicles require larger lift capacities and force the mission to become extremely costly. In order to build large volume habitable vehicles, with only minimal increases in launch volume and mass, NASA is developing lightweight structures. Lightweight structures are made from non-metallic materials including graphite composites and high strength fabrics and could provide similar or better structural capability than metals, but with significant launch volume and mass savings. Fabric structures specifically, have been worked by NASA off and on since its inception, but most notably in the 1990's with the TransHAB program. These TransHAB developed structures use a layered material approach to form a pressure vessel with integrated thermal and micro-meteoroid and orbital debris (MMOD) protection. The flexible fabrics allow the vessel to be packed in a small volume during launch and expand into a much larger volume once in orbit. NASA and Bigelow Aerospace recently installed the first human-rated inflatable module on the International Space Station (ISS), known as the Bigelow Expandable Activity Module (BEAM) in May of 2016. The module provides a similar internal volume to that of an Orbital ATK Cygnus cargo vehicle, but with a 77% launch volume savings. As lightweight structures are developed, testing methods are vital to understanding their behavior and validating analytical models. Common techniques can be applied to fabric materials

  9. Epidemiology and Burden of Bloodstream Infections Caused by Extended-Spectrum Beta-Lactamase Producing Enterobacteriaceae in a Pediatric Hospital in Senegal.

    Directory of Open Access Journals (Sweden)

    Awa Ndir

    Full Text Available Severe bacterial infections are not considered as a leading cause of death in young children in sub-Saharan Africa. The worldwide emergence of extended-spectrum beta-lactamase producing Enterobacteriaceae (ESBL-E could change the paradigm, especially in neonates who are at high risk of developing healthcare-associated infections.To evaluate the epidemiology and the burden of ESBL-E bloodstream infections (BSI.A case-case-control study was conducted in patients admitted in a pediatric hospital during two consecutive years. Cases were patients with Enterobacteriaceae BSI and included ESBL-positive (cases 1 and ESBL-negative BSI (cases 2. Controls were patients with no BSI. Multivariate analysis using a stepwise logistic regression was performed to identify risk factors for ESBL acquisition and for fatal outcomes. A multistate model was used to estimate the excess length of hospital stay (LOS attributable to ESBL production while accounting for time of infection. Cox proportional hazards models were performed to assess the independent effect of ESBL-positive and negative BSI on LOS.The incidence rate of ESBL-E BSI was of 1.52 cases/1000 patient-days (95% CI: 1.2-5.6 cases per 1000 patient-days. Multivariate analysis showed that independent risk factors for ESBL-BSI acquisition were related to underlying comorbidities (sickle cell disease OR = 3.1 (95%CI: 2.3-4.9, malnutrition OR = 2.0 (95%CI: 1.7-2.6 and invasive procedures (mechanical ventilation OR = 3.5 (95%CI: 2.7-5.3. Neonates were also identified to be at risk for ESBL-E BSI. Inadequate initial antibiotic therapy was more frequent in ESBL-positive BSI than ESBL-negative BSI (94.2% versus 5.7%, p<0.0001. ESBL-positive BSI was associated with higher case-fatality rate than ESBL-negative BSI (54.8% versus 15.4%, p<0.001. Multistate modelling indicated an excess LOS attributable to ESBL production of 4.3 days. The adjusted end-of-LOS hazard ratio for ESBL-positive BSI was 0.07 (95%CI, 0

  10. Presence of Mycoplasma fermentans in the bloodstream of Mexican patients with rheumatoid arthritis and IgM and IgG antibodies against whole microorganism

    Directory of Open Access Journals (Sweden)

    Salinas Salvador

    2009-08-01

    Full Text Available Abstract Background Increasing evidence incriminates bacteria, especially Mycoplasma fermentans, as possible arthritogenic agents in humans. The purpose of this study was to investigate M. fermentans in the bloodstream of patients with rheumatoid arthritis. Methods Two hundred and nineteen blood samples from patients with rheumatoid arthritis, systemic lupus erythematosus, antiphospholipid syndrome, and healthy individuals were screened by bacterial culture and direct PCR in order to detect mycoplasmas; IgM and IgG against M. fermentans PG18 were also detected by ELISA and Immunoblotting assays in patients with rheumatoid arthritis and healthy individuals. Results Blood samples from patients with antiphospholipid syndrome and healthy individuals were negative for mycoplasma by culture or direct PCR. In blood samples from patients with systemic lupus erythematosus were detected by direct PCR M. fermentans in 2/50 (2%, M. hominis in 2/50 (2% and U. urealyticum in 1/50 (0.5%. In patients with RA M. fermentans was detected by culture in 13/87 blood samples and in 13/87 by direct PCR, however, there was only concordance between culture and direct PCR in six samples, so M. fermentans was detected in 20/87(23% of the blood samples from patients with RA by either culture or PCR. Antibody-specific ELISA assay to M. fermentans PG18 was done, IgM was detected in sera from 40/87 patients with RA and in sera of 7/67 control individuals, IgG was detected in sera from 48/87 RA patients and in sera from 7/67 healthy individuals. Antibody-specific immunoblotting to M. fermentans PG18 showed IgM in sera from 35/87 patients with RA and in sera from 4/67 healthy individuals, IgG was detected in sera from 34/87 patients and in sera from 5/67 healthy individuals. Conclusion Our findings show that only M. fermentans produce bacteremia in a high percentage of patients with RA. This finding is similar to those reported in the literature. IgM and IgG against M

  11. A Multinational, Preregistered Cohort Study of β-Lactam/β-Lactamase Inhibitor Combinations for Treatment of Bloodstream Infections Due to Extended-Spectrum-β-Lactamase-Producing Enterobacteriaceae.

    Science.gov (United States)

    Gutiérrez-Gutiérrez, Belén; Pérez-Galera, Salvador; Salamanca, Elena; de Cueto, Marina; Calbo, Esther; Almirante, Benito; Viale, Pierluigi; Oliver, Antonio; Pintado, Vicente; Gasch, Oriol; Martínez-Martínez, Luis; Pitout, Johann; Akova, Murat; Peña, Carmen; Molina, José; Hernández, Alicia; Venditti, Mario; Prim, Nuria; Origüen, Julia; Bou, German; Tacconelli, Evelina; Tumbarello, Mario; Hamprecht, Axel; Giamarellou, Helen; Almela, Manel; Pérez, Federico; Schwaber, Mitchell J; Bermejo, Joaquín; Lowman, Warren; Hsueh, Po-Ren; Mora-Rillo, Marta; Natera, Clara; Souli, Maria; Bonomo, Robert A; Carmeli, Yehuda; Paterson, David L; Pascual, Alvaro; Rodríguez-Baño, Jesús

    2016-07-01

    The spread of extended-spectrum-β-lactamase (ESBL)-producing Enterobacteriaceae (ESBL-E) is leading to increased carbapenem consumption. Alternatives to carbapenems need to be investigated. We investigated whether β-lactam/β-lactamase inhibitor (BLBLI) combinations are as effective as carbapenems in the treatment of bloodstream infections (BSI) due to ESBL-E. A multinational, retrospective cohort study was performed. Patients with monomicrobial BSI due to ESBL-E were studied; specific criteria were applied for inclusion of patients in the empirical-therapy (ET) cohort (ETC; 365 patients), targeted-therapy (TT) cohort (TTC; 601 patients), and global cohort (GC; 627 patients). The main outcome variables were cure/improvement rate at day 14 and all-cause 30-day mortality. Multivariate analysis, propensity scores (PS), and sensitivity analyses were used to control for confounding. The cure/improvement rates with BLBLIs and carbapenems were 80.0% and 78.9% in the ETC and 90.2% and 85.5% in the TTC, respectively. The 30-day mortality rates were 17.6% and 20% in the ETC and 9.8% and 13.9% in the TTC, respectively. The adjusted odds ratio (OR) (95% confidence interval [CI]) values for cure/improvement rate with ET with BLBLIs were 1.37 (0.69 to 2.76); for TT, they were 1.61 (0.58 to 4.86). Regarding 30-day mortality, the adjusted OR (95% CI) values were 0.55 (0.25 to 1.18) for ET and 0.59 (0.19 to 1.71) for TT. The results were consistent in all subgroups studied, in a stratified analysis according to quartiles of PS, in PS-matched cases, and in the GC. BLBLIs, if active in vitro, appear to be as effective as carbapenems for ET and TT of BSI due to ESLB-E regardless of the source and specific species. These data may help to avoid the overuse of carbapenems. (This study has been registered at ClinicalTrials.gov under registration no. NCT01764490.). PMID:27139473

  12. Prevalence of Resistant Gram-Negative Bacilli in Bloodstream Infection in Febrile Neutropenia Patients Undergoing Hematopoietic Stem Cell Transplantation: A Single Center Retrospective Cohort Study.

    Science.gov (United States)

    Wang, Ling; Wang, Ying; Fan, Xing; Tang, Wei; Hu, Jiong

    2015-11-01

    Bloodstream infection (BSI) is an important cause of morbidity and mortality in patients undergoing hematopoietic stem cell transplantation (HSCT). To evaluate the causative bacteria and identify risk factors for BSI associated mortality in febrile neutropenia patients undergoing HSCT, we collected the clinical and microbiological data from patients underwent HSCT between 2008 and 2014 and performed a retrospective analysis. Throughout the study period, among 348 episodes of neutropenic fever in patients underwent HSCT, 89 episodes in 85 patients had microbiological defined BSI with a total of 108 isolates. Gram-negative bacteria (GNB) were the most common isolates (76, 70.3%) followed by gram-positive bacteria (GPB, 29, 26.9%) and fungus (3, 2.8%). As to the drug resistance, 26 multiple drug resistance (MDR) isolates were identified. Resistant isolates (n = 23) were more common documented in GNB, mostly Escherichia coli (9/36, 25%) and Klebsiella pneumonia (6/24, 25%). A total of 12 isolated were resistant to carbapenem including 4 K pneumoniae (4/24, 16.7%), 3 Stenotrophomonas maltophilia, and 1 Pseudomonas aeruginosa and other 4 GNB isolates (Citrobacter freumdii, Pseudomonas stutzeri, Acinetobacter baumanii, and Chryseobacterium indologenes). As to the GPB, only 3 resistant isolates were documented including 2 methicillin-resistant isolates (Staphylococcus hominis and Arcanobacterium hemolysis) and 1 vancomycin-resistant Enterococcus faecium. Among these 85 patients with documented BSI, 11 patients died of BSI as primary or associated cause with a BSI-related mortality of 13.1 ± 3.7% and 90-day overall survival after transplantation at 80.0 ± 4.3%. Patients with high-risk disease undergoing allo-HSCT, prolonged neutropenia (≥15 days) and infection with carbapenem-resistant GNB were associated with BSI associated mortality in univariate and multivariate analyses. Our report revealed a prevalence of GNB in BSI of neutropenic patients undergoing

  13. Klebsiella variicola is a frequent cause of bloodstream infection in the stockholm area, and associated with higher mortality compared to K. pneumoniae.

    Directory of Open Access Journals (Sweden)

    Makaoui Maatallah

    Full Text Available Clinical isolates of Klebsiella pneumoniae are divided into three phylogroups and differ in their virulence factor contents. The aim of this study was to determine an association between phylogroup, virulence factors and mortality following bloodstream infection (BSI caused by Klebsiella pneumoniae. Isolates from all adult patients with BSI caused by K. pneumoniae admitted to Karolinska University Hospital, Solna between 2007 and 2009 (n = 139 were included in the study. Phylogenetic analysis was performed based on multilocus sequence typing (MLST data. Testing for mucoid phenotype, multiplex PCR determining serotypes K1, K2, K5, K20, K54 and K57, and testing for virulence factors connected to more severe disease in previous studies, was also performed. Data was retrieved from medical records including age, sex, comorbidity, central and urinary catheters, time to adequate treatment, hospital-acquired infection, and mortality, to identify risk factors. The primary end-point was 30- day mortality. The three K. pneumoniae phylogroups were represented: KpI (n = 96, KpII (corresponding to K. quasipneumoniae, n = 9 and KpIII (corresponding to K. variicola, n = 34. Phylogroups were not significantly different in baseline characteristics. Overall, the 30-day mortality was 24/139 (17.3%. Isolates belonging to KpIII were associated with the highest 30-day mortality (10/34 cases, 29.4%, whereas KpI isolates were associated with mortality in 13/96 cases (13.5%. This difference was significant both in univariate statistical analysis (P = 0.037 and in multivariate analysis adjusting for age and comorbidity (OR 3.03 (95% CI: 1.10-8.36. Only three of the isolates causing mortality within 30 days belonged to any of the virulent serotypes (K54, n = 1, had a mucoid phenotype (n = 1 and/or contained virulence genes (wcaG n = 1 and wcaG/allS n = 1. In conclusion, the results indicate higher mortality among patients infected with

  14. Linkage, evaluation and analysis of national electronic healthcare data: application to providing enhanced blood-stream infection surveillance in paediatric intensive care.

    Directory of Open Access Journals (Sweden)

    Katie Harron

    Full Text Available BACKGROUND: Linkage of risk-factor data for blood-stream infection (BSI in paediatric intensive care (PICU with bacteraemia surveillance data to monitor risk-adjusted infection rates in PICU is complicated by a lack of unique identifiers and under-ascertainment in the national surveillance system. We linked, evaluated and performed preliminary analyses on these data to provide a practical guide on the steps required to handle linkage of such complex data sources. METHODS: Data on PICU admissions in England and Wales for 2003-2010 were extracted from the Paediatric Intensive Care Audit Network. Records of all positive isolates from blood cultures taken for children <16 years and captured by the national voluntary laboratory surveillance system for 2003-2010 were extracted from the Public Health England database, LabBase2. "Gold-standard" datasets with unique identifiers were obtained directly from three laboratories, containing microbiology reports that were eligible for submission to LabBase2 (defined as "clinically significant" by laboratory microbiologists. Reports in the gold-standard datasets were compared to those in LabBase2 to estimate ascertainment in LabBase2. Linkage evaluated by comparing results from two classification methods (highest-weight classification of match weights and prior-informed imputation using match probabilities with linked records in the gold-standard data. BSI rate was estimated as the proportion of admissions associated with at least one BSI. RESULTS: Reporting gaps were identified in 548/2596 lab-months of LabBase2. Ascertainment of clinically significant BSI in the remaining months was approximately 80-95%. Prior-informed imputation provided the least biased estimate of BSI rate (5.8% of admissions. Adjusting for ascertainment, the estimated BSI rate was 6.1-7.3%. CONCLUSION: Linkage of PICU admission data with national BSI surveillance provides the opportunity for enhanced surveillance but analyses based on

  15. A study on the UNDEX cup forming

    Directory of Open Access Journals (Sweden)

    A.E. El Mokadem*, A.S. Wifi, I. Salama

    2009-12-01

    Full Text Available Purpose: This work investigates the use of the underwater explosion (UNDEX for the free and plug assisted cup forming processes.Design/methodology/approach: A 3D finite element model is built to simulate the process of the UNDEX cup forming using ABAQUS finite element code. Johnson-Cook (JC material plasticity model is used to represent strain rate sensitivity of the used materials. Johnson- Cook damage criterion is employed to detect the onset of damage in the cup forming process.Findings: Both relatively hard and soft plugs are considered and the effects of using different plug materials on cup profile, strains and the limiting drawing ratios are given. The onset of damage in this process is also indicated. The results suggest that a relatively hard plug can enhance the control of the cup shape and the uniformity of strain distribution leading to increased limiting drawing ratio.Research limitations/implications: This work suggests a methodology for the prediction of shape, different strain distribution, the limiting drawing ratio and the energy required for UNDEX cup forming process.Practical implications: This study could be useful in non-conventional high energy rate forming industry.Originality/value: The study reveals the possibility of producing flat-bottomed cup by the relatively hard plug assisted UNDEX forming technique.

  16. Densified waste form and method for forming

    Energy Technology Data Exchange (ETDEWEB)

    Garino, Terry J.; Nenoff, Tina M.; Sava Gallis, Dorina Florentina

    2015-08-25

    Materials and methods of making densified waste forms for temperature sensitive waste material, such as nuclear waste, formed with low temperature processing using metallic powder that forms the matrix that encapsulates the temperature sensitive waste material. The densified waste form includes a temperature sensitive waste material in a physically densified matrix, the matrix is a compacted metallic powder. The method for forming the densified waste form includes mixing a metallic powder and a temperature sensitive waste material to form a waste form precursor. The waste form precursor is compacted with sufficient pressure to densify the waste precursor and encapsulate the temperature sensitive waste material in a physically densified matrix.

  17. Densified waste form and method for forming

    Energy Technology Data Exchange (ETDEWEB)

    Garino, Terry J.; Nenoff, Tina M.; Sava Gallis, Dorina Florentina

    2016-05-17

    Materials and methods of making densified waste forms for temperature sensitive waste material, such as nuclear waste, formed with low temperature processing using metallic powder that forms the matrix that encapsulates the temperature sensitive waste material. The densified waste form includes a temperature sensitive waste material in a physically densified matrix, the matrix is a compacted metallic powder. The method for forming the densified waste form includes mixing a metallic powder and a temperature sensitive waste material to form a waste form precursor. The waste form precursor is compacted with sufficient pressure to densify the waste precursor and encapsulate the temperature sensitive waste material in a physically densified matrix.

  18. Factores de riesgo de infecciones del tracto sanguíneo asociadas a alimentación parenteral en pacientes pediátricos Risk factors of bloodstream infections associated with parenteral nutrition in pediatric patients

    Directory of Open Access Journals (Sweden)

    P. Balboa Cardemil

    2011-12-01

    Full Text Available Introducción: Una de las complicaciones de la nutrición parenteral (NP es la infección sanguínea (IS asociada a catéter, se desconoce los factores de riesgo más importantes en nuestro medio. Objetivo: Determinar los factores de riesgo de las IS asociadas a NP en pacientes pediátricos en hospitales de Santiago de Chile. Pacientes y métodos: En 2 hospitales públicos se analizaron retrospectivamente todos los recién nacidos (RN y niños que recibieron NP entre enero del 2002 y diciembre del 2005. El grupo estudio (GE son todos aquellos con hemocultivos (+ durante la administración de NP. El grupo control (GC correspondió a 2 controles por cada caso, niños con NP y hemocultivos (-. Para el análisis estadístico se usaron pruebas paramétricas, no paramétricas y regresión logística. Resultados: Se obtuvieron 58 casos y 130 controles. Los niños del GE recibieron NP por más tiempo que GC: 24 (7-934 vs 10 días (7-152 (p Introduction: One of the complications of parenteral nutrition (PN is bloodstream infection (BSI associated with catheter, unknown the most important risk factors in our country. Objective: To determine risk factors of BSI associated with PN in pediatric patients in public hospitals of Santiago, Chile. Patients and methods: In two public hospitals all newborns and children receiving PN were analyzed retrospectively, from January 2002 to December 2005. The study group (SG was formed by all those with blood cultures (+ during the administration of PN. We selected two controls for each case, children with PN and blood cultures (- (control group, CG. We used parametric, nonparametric and logistic regression to analyze data. Results: There were 58 cases and 130 controls. Children of the SG received PN for longer days than CG: 24 (7-934 vs. 10 days (7-152 (p < 0.001, presented a higher rate of malnutrition (44.4% vs. 31%, chi2, p < 0.05 and received more frequently PN by central venous catheter than peripheral catheter (GE

  19. Multilocus Microsatellite Markers for Molecular Typing of Candida glabrata: Application to Analysis of Genetic Relationships between Bloodstream and Digestive System Isolates▿

    OpenAIRE

    Enache-Angoulvant, A.; BOURGET, M; S Brisse; Stockman-Pannier, C.; Diancourt, L.; François, N.; Rimek, D.; Fairhead, C; Poulain, Daniel; Hennequin, C.

    2010-01-01

    Candida glabrata has emerged as the second most common etiologic agent, after Candida albicans, of superficial and invasive candidiasis in adults. Strain typing is essential for epidemiological investigation, but easy-to-use and reliable typing methods are still lacking. We report the use of a multilocus microsatellite typing method with a set of eight markers on a panel of 180 strains, including 136 blood isolates from hospitalized patients and 34 digestive tract isolates from nonhospitalize...

  20. Vortex induced strain effects in anisotropic superconductors

    International Nuclear Information System (INIS)

    Strain in a superconductor, produced by the normal vortex core, can affect both static and dynamic properties of vortices. It causes an additional vortex-vortex interaction which is long-ranged (∼ 1/r2) as compared with finite but much stronger London interaction in the fields far below Hc2. The energy of this magneto-elastic interaction is calculated within London model. The role of strain effects in forming vortex lattice structure is demonstrated for YBa2Cu3O7

  1. Characterization Of Biaxial Strain Of Poly(L-Lactide) Tubes

    DEFF Research Database (Denmark)

    Løvdal, Alexandra Liv Vest; Andreasen, Jens Wenzel; Mikkelsen, Lars Pilgaard;

    2016-01-01

    ) biaxial strain process, the mechanical properties of biaxial strained tubes can be further improved. This study investigated these properties in relation to their morphology and crystal orientation. Both processes yield the same mechanical strength and modulus, yet exhibit different crystal orientation......Poly(L-lactide) (PLLA) in its L-form has promising mechanical properties. Being a semi-crystalline polymer, it can be subjected to strain-induced crystallization at temperatures above Tg and can thereby become oriented. Following a simultaneous (SIM) biaxial strain process or a sequential (SEQ...

  2. Longitudinal misalignment based strain sensor

    OpenAIRE

    Andrews, Jeffrey Pratt

    1989-01-01

    A practical fiber optic strain sensor has been developed to measure strains in the range of 0.0 to 2.0 percent strain with a resolution ranging between 10 and 100 microstrain depending on sensor design choices. This intensity based sensor measures strain by monitoring strain induced longitudinal misalignment in a novel fiber interconnection. This interconnection is created by aligning fibers within a segment of hollow core fiber. Related splice loss mechanisms are investigated ...

  3. ConStrains identifies microbial strains in metagenomic datasets.

    Science.gov (United States)

    Luo, Chengwei; Knight, Rob; Siljander, Heli; Knip, Mikael; Xavier, Ramnik J; Gevers, Dirk

    2015-10-01

    An important fraction of microbial diversity is harbored in strain individuality, so identification of conspecific bacterial strains is imperative for improved understanding of microbial community functions. Limitations in bioinformatics and sequencing technologies have to date precluded strain identification owing to difficulties in phasing short reads to faithfully recover the original strain-level genotypes, which have highly similar sequences. We present ConStrains, an open-source algorithm that identifies conspecific strains from metagenomic sequence data and reconstructs the phylogeny of these strains in microbial communities. The algorithm uses single-nucleotide polymorphism (SNP) patterns in a set of universal genes to infer within-species structures that represent strains. Applying ConStrains to simulated and host-derived datasets provides insights into microbial community dynamics. PMID:26344404

  4. Realization of a Strained Atomic Wire Superlattice.

    Science.gov (United States)

    Song, Inkyung; Goh, Jung Suk; Lee, Sung-Hoon; Jung, Sung Won; Shin, Jin Sung; Yamane, Hiroyuki; Kosugi, Nobuhiro; Yeom, Han Woong

    2015-11-24

    A superlattice of strained Au-Si atomic wires is successfully fabricated on a Si surface. Au atoms are known to incorporate into the stepped Si(111) surface to form a Au-Si atomic wire array with both one-dimensional (1D) metallic and antiferromagnetic atomic chains. At a reduced density of Au, we find a regular array of Au-Si wires in alternation with pristine Si nanoterraces. Pristine Si nanoterraces impose a strain on the neighboring Au-Si wires, which modifies both the band structure of metallic chains and the magnetic property of spin chains. This is an ultimate 1D version of a strained-layer superlattice of semiconductors, defining a direction toward the fine engineering of self-assembled atomic-scale wires. PMID:26446292

  5. Electro-Hydraulic Forming of Sheet Metals: Free-forming vs. Conical-die Forming

    Energy Technology Data Exchange (ETDEWEB)

    Rohatgi, Aashish; Stephens, Elizabeth V.; Davies, Richard W.; Smith, Mark T.; Soulami, Ayoub; Ahzi, Said

    2012-05-01

    This work builds upon our recent advances in quantifying high-rate deformation behavior of sheet metals, during electro-hydraulic forming (EHF), using high-speed imaging and digital image correlation techniques. Following recent publication of an earlier manuscript, resulting from this project, in the Journal of Materials Processing Technology, this manuscript further details our results and compares forming behavior when the process is carried out inside an open-die or a conical die. It is anticipated that quantitative information of the sheet deformation history, made possible by the experimental technique developed in this work, will improve our understanding on the roles of strain-rate and sheet-die interactions in enhancing the sheet metal formability during high-rate forming. This knowledge will be beneficial to the automotive industry and enable them to fabricate light-weight sheet parts out of Al and advanced high strength steels.

  6. Strain Engineering to Modify the Electrochemistry of Energy Storage Electrodes

    Science.gov (United States)

    Muralidharan, Nitin; Carter, Rachel; Oakes, Landon; Cohn, Adam P.; Pint, Cary L.

    2016-01-01

    Strain engineering has been a critical aspect of device design in semiconductor manufacturing for the past decade, but remains relatively unexplored for other applications, such as energy storage. Using mechanical strain as an input parameter to modulate electrochemical potentials of metal oxides opens new opportunities intersecting fields of electrochemistry and mechanics. Here we demonstrate that less than 0.1% strain on a Ni-Ti-O based metal-oxide formed on superelastic shape memory NiTi alloys leads to anodic and cathodic peak potential shifts by up to ~30 mV in an electrochemical cell. Moreover, using the superelastic properties of NiTi to enable strain recovery also recovers the electrochemical potential of the metal oxide, providing mechanistic evidence of strain-modified electrochemistry. These results indicate that mechanical energy can be coupled with electrochemical systems to efficiently design and optimize a new class of strain-modulated energy storage materials. PMID:27283872

  7. Strain Engineering to Modify the Electrochemistry of Energy Storage Electrodes

    Science.gov (United States)

    Muralidharan, Nitin; Carter, Rachel; Oakes, Landon; Cohn, Adam P.; Pint, Cary L.

    2016-06-01

    Strain engineering has been a critical aspect of device design in semiconductor manufacturing for the past decade, but remains relatively unexplored for other applications, such as energy storage. Using mechanical strain as an input parameter to modulate electrochemical potentials of metal oxides opens new opportunities intersecting fields of electrochemistry and mechanics. Here we demonstrate that less than 0.1% strain on a Ni-Ti-O based metal-oxide formed on superelastic shape memory NiTi alloys leads to anodic and cathodic peak potential shifts by up to ~30 mV in an electrochemical cell. Moreover, using the superelastic properties of NiTi to enable strain recovery also recovers the electrochemical potential of the metal oxide, providing mechanistic evidence of strain-modified electrochemistry. These results indicate that mechanical energy can be coupled with electrochemical systems to efficiently design and optimize a new class of strain-modulated energy storage materials.

  8. The strained state cosmology

    Science.gov (United States)

    Tartaglia, Angelo

    2016-01-01

    Starting from some relevant facts concerning the behavior of the universe over large scale and time span, the analogy between the geometric approach of General Relativity and the classical description of an elastic strained material continuum is discussed. Extending the elastic deformation approach to four dimensions it is shown that the accelerated expansion of the universe is recovered. The strain field of space-time reproduces properties similar to the ones ascribed to the dark energy currently called in to explain the accelerated expansion. The strain field in the primordial universe behaves as radiation, but asymptotically it reproduces the cosmological constant. Subjecting the theory to a number of cosmological tests confirms the soundness of the approach and gives an optimal value for the one parameter of the model, i.e. the bulk modulus of the space-time continuum. Finally various aspects of the Strained State Cosmology (SSC) are discussed and contrasted with some non-linear massive gravity theories. The possible role of structure topological defects is also mentioned. The conclusion is that SSC is at least as good as the ΛCDM standard cosmology, giving a more intuitive interpretation of the physical nature of the phenomena.

  9. Network of flexible capacitive strain gauges for the reconstruction of surface strain

    International Nuclear Information System (INIS)

    Monitoring of surface strain on mesosurfaces is a difficult task, often impeded by the lack of scalability of conventional sensing systems. A solution is to deploy large networks of flexible strain gauges, a type of large area electronics. The authors have recently proposed a soft elastomeric capacitor (SEC) as an economical skin-type solution for large-scale deployment onto mesosurfaces. The sensing principle is based on a measurable change in the sensor’s capacitance upon strain. In this paper, we study the performance of the sensor at reconstructing surface strain map and deflection shapes. A particular feature of the sensor is that it measures surface strain additively, because it is not utilized within a Wheatstone bridge configuration. An algorithm is proposed to decompose the additive in-plane strain measurements from the SEC into principal components. The algorithm consists of assuming a polynomial shape function, and deriving the strain based on Kirchhoff plate theory. A least-squares estimator (LSE) is used to minimize the error between the assumed model and the SEC signals after the enforcement of boundary conditions. Numerical simulations are conducted on a symmetric rectangular cantilever thin plate under symmetric and asymmetric static loads to demonstrate the accuracy and real-time applicability of the algorithm. The performance of the algorithm is further examined on an asymmetric cantilever laminated thin plate constituted with orthotropic materials mimicking a wind turbine blade, and subjected to a non-stationary wind load. Results from simulations show good performance of the algorithm at reconstructing the surface strain maps for both in-plane principal strain components, and that it can be applied in real time. However, its performance can be improved by strengthening assumptions on boundary conditions. The algorithm exhibits robustness in performance with respect to load and noise in signals, except when most of the sensors’ signals are

  10. Network of flexible capacitive strain gauges for the reconstruction of surface strain

    Science.gov (United States)

    Wu, Jingzhe; Song, Chunhui; Saleem, Hussam S.; Downey, Austin; Laflamme, Simon

    2015-05-01

    Monitoring of surface strain on mesosurfaces is a difficult task, often impeded by the lack of scalability of conventional sensing systems. A solution is to deploy large networks of flexible strain gauges, a type of large area electronics. The authors have recently proposed a soft elastomeric capacitor (SEC) as an economical skin-type solution for large-scale deployment onto mesosurfaces. The sensing principle is based on a measurable change in the sensor’s capacitance upon strain. In this paper, we study the performance of the sensor at reconstructing surface strain map and deflection shapes. A particular feature of the sensor is that it measures surface strain additively, because it is not utilized within a Wheatstone bridge configuration. An algorithm is proposed to decompose the additive in-plane strain measurements from the SEC into principal components. The algorithm consists of assuming a polynomial shape function, and deriving the strain based on Kirchhoff plate theory. A least-squares estimator (LSE) is used to minimize the error between the assumed model and the SEC signals after the enforcement of boundary conditions. Numerical simulations are conducted on a symmetric rectangular cantilever thin plate under symmetric and asymmetric static loads to demonstrate the accuracy and real-time applicability of the algorithm. The performance of the algorithm is further examined on an asymmetric cantilever laminated thin plate constituted with orthotropic materials mimicking a wind turbine blade, and subjected to a non-stationary wind load. Results from simulations show good performance of the algorithm at reconstructing the surface strain maps for both in-plane principal strain components, and that it can be applied in real time. However, its performance can be improved by strengthening assumptions on boundary conditions. The algorithm exhibits robustness in performance with respect to load and noise in signals, except when most of the sensors’ signals are

  11. CRP和PCT检测对血流感染的诊断价值%Value of Diagnosis of CRP and PCT in the Differential Diagnosis of Bloodstream Infection

    Institute of Scientific and Technical Information of China (English)

    张佳夫; 李艳玲

    2016-01-01

    Objective To discuss the value of diagnosis of CRP and PCT in the differential diagnosis of bloodstream infection. Methods 217 cases of fever patients were put into positive group and negative group according to the blood culture. Detection of peripheral blood CRP and PCT levels in all patients. Based on the blood cultures were divided into gram positive and gram negative groups, and then detected the level of CRP and PCT. Results Positive group, the positive rate of PCT (99.16%) is higher than the negative group (30.61%) (P<0.05), positive group, the levels of CRP and PCT were higher than those of the negative group (P<0.05), leather gram positive serum PCT levels (3.48±1.15) ng/ml below the leather blue negative group (7.08±0.67) ng/ml (P<0.05). Conclusion CRP and PCT can be used as an indicator of blood flow infection, but PCT has high specificity, and the level of serum PCT in patients with gram positive bacterial infection was significantly lower than that of gram negative bacteria infection.%目的:探讨 C 反应蛋白(CRP)和降钙素原(PCT)对血流感染的诊断价值。方法对217例发热患者根据血培养分为阳性组和阴性组,对所有患者入院当天外周血 CRP 和 PCT 进行定量和定性检测,对血培养阳性患者根据病原菌革兰染色分为革兰染色阳性组和革兰染色阴性组,并进行 CRP 和 PCT 定量检测。结果阳性组 PCT 阳性率(99.16%)高于阴性组(30.61%)(P <0.05);阳性组 CRP 和 PCT水平均高于阴性组(P <0.05);革兰阳性组 PCT 水平(3.48±1.15) ng/ml 低于革兰阴性组(7.08±0.67)ng/ml(P <0.05)。结论 CRP 和PCT 均可作为初步判断血流感染的指标,但 PCT 具有较高的特异性,且革兰阳性菌感染患者血清 PCT 水平低于革兰阴性菌感染的患者。

  12. Novel strained superjunction VDMOS

    Science.gov (United States)

    Naugarhiya, Alok; Dubey, Shashank; Kondekar, Pravin N.

    2015-09-01

    In this paper, we have proposed novel strained superjunction (s-SJ) vertical double diffused MOS (VDMOS). Through channel engineering, we have introduced strain effects in s-SJ device using thin separate p-type silicon-germanium (p-SiGe) layer over silicon p-pillar. Further, we have designed process flow for the possible fabrication of s-SJ VDMOS. The proposed s-SJ devices fitted with less input capacitance (Cin) and 1.2∼3 times higher output current density than conventional SJ VDMOS. Therefore, 40% less gate charge (Qg) is required to turn-on the s-SJ VDMOS and Ron A is optimized in between 12% and 46%.

  13. Cells as strain-cued automata

    Science.gov (United States)

    Cox, Brian N.; Snead, Malcolm L.

    2016-02-01

    We argue in favor of representing living cells as automata and review demonstrations that autonomous cells can form patterns by responding to local variations in the strain fields that arise from their individual or collective motions. An autonomous cell's response to strain stimuli is assumed to be effected by internally-generated, internally-powered forces, which generally move the cell in directions other than those implied by external energy gradients. Evidence of cells acting as strain-cued automata have been inferred from patterns observed in nature and from experiments conducted in vitro. Simulations that mimic particular cases of pattern forming share the idealization that cells are assumed to pass information among themselves solely via mechanical boundary conditions, i.e., the tractions and displacements present at their membranes. This assumption opens three mechanisms for pattern formation in large cell populations: wavelike behavior, kinematic feedback in cell motility that can lead to sliding and rotational patterns, and directed migration during invasions. Wavelike behavior among ameloblast cells during amelogenesis (the formation of dental enamel) has been inferred from enamel microstructure, while strain waves in populations of epithelial cells have been observed in vitro. One hypothesized kinematic feedback mechanism, "enhanced shear motility", accounts successfully for the spontaneous formation of layered patterns during amelogenesis in the mouse incisor. Directed migration is exemplified by a theory of invader cells that sense and respond to the strains they themselves create in the host population as they invade it: analysis shows that the strain fields contain positional information that could aid the formation of cell network structures, stabilizing the slender geometry of branches and helping govern the frequency of branch bifurcation and branch coalescence (the formation of closed networks). In simulations of pattern formation in

  14. Distribution and Drug Resistance of Pathogenic Bacteria in 575 Cases of Bloodstream Infection%血流感染575例病原菌分布及耐药性分析

    Institute of Scientific and Technical Information of China (English)

    李文利; 吴诗品; 陈洪涛; 吴劲松

    2009-01-01

    Objective To study the distribution and drug resistance of pathogenic bacteria in patients with bloodstream infection(BSI).Methods Five hundred and seventy-five BSI patients hospitalized from Jan.2004 to Nov.2008 were enrolled to perform a retrospective analysis on bacterial identification and drug sensitive test results.Results A total of 645 strains of pathogenic bacteria were isolated,including 338 gram-negative (52.4%),267 gram-positive(41.4%),40 fungi(6.2%).Mixed infection was found in 52 patients.The isolated pathogenic bacteria were mainly coagulase-negative staphylococci(27.6%),Escherichia coli(21.7%),klebsiella pneumoniae(12.6%),glucose non-fermentative bacteria(9.9%),enterococcus(3.9%).The detection rates of Escherichia coli and klebsiella pneumoniae producing superspectrum β-lactamases (ESBLs)were 46.4%,19.7%,respectively;those of methicillin resistant S.aureus(MRSA) and meticillin-resistant coagulase-negative staphylococci(MRCNS) were 54.8%,89.3%,respectively.Glucose non-fermentative bacteria,acinetobacter baumannii,pseudomonas aeruginosa and burkholderia cepacia were highly resistant to most antimicrobials;gram-positive cocci resistant to vancomycin were not found.Conclusion The pathogenic bacteria inducing BSI are mainly gram-negative,and the multiple drug resistance of BSI pathogenic bacteria,especially glucose non-fermentative,is increasing.Monitoring drug resistance of pathogenic bacteria is of importance in guiding clinical rational use of antimicrobial drugs and reducing drug resistance bacteria.%目的 探讨近年来血流感染的病原菌分布及其对抗菌药物的耐药状况.方法 选择2004年1月-2008年11月在我院住院的575例血流感染患者,对患者的细菌鉴定及药敏试验结果进行回顾性分析.结果 从575例血流感染患者中共分离出645株病原菌,其中革兰阴性菌338株(占52.4%)、革兰阳性菌267株(占41.4%)、真菌40株(占6.2%),52例患者发生混合感染.分离的病原菌中,主要

  15. Geodetic surveying of strains

    Energy Technology Data Exchange (ETDEWEB)

    Meixner, H.

    1980-11-01

    This article evaluates methods and apparatus used in the German Democratic Republic to assess vertical and horizontal deformations and strains caused by coal mining and mining of other deposits. Each of the methods is characterized; type of measuring apparatus and its accuracy is given. The following conventional methods of surveying are characterized: (I.) vertical strains: measurement with hydrostatic tube balance (apparatus produced by the Praezisionsmechanik Freiberg, with accuracy of 0.01 mm), trigonometric levelling (error up to 10 mm), geometric levelling (NI 007 and NI 008 apparatus produced by Carl Zeiss JENA), and direct height measuring; (II.) horizontal strains: direct surveying with accuracy higher than 5 mm/50 m, indirect surveying (theodolite THEO 010 A produced by the Carl Zeiss JENA), and alignment method (using apparatus produced by Praezisionsmechanik, Freiberg). Advanced surveying methods are also discussed: electro-optical method (using EOK 2000 range finder produced by Carl Zeiss JENA, with average error ranging from 5 mm to 10 mm), laser method (LF-1 and LFG-1 lasers produced by Carl Zeiss JENA), measuring gyroscope used to measure contorsion (MRK 2 gyroscope produced by the Praezisionsmechanik, Freiberg); photogrammetry: stereophotogrammetry and so-called parallel photogrammetry. (15 refs.) (In Polish)

  16. Temperature controlled strain gaged extensometer

    Science.gov (United States)

    Ramos, G. L.; Seplow, S.

    1968-01-01

    Temperature controlled strain-gaged extensometer measures longitudinal and girth deflections of pressure vessels in excess of one percent strain during pressurization and depressurization with cryogenic fluids at cryogenic temperatures. The device is of beryllium-copper strips.

  17. Strain localization analysis using a multiscale model

    OpenAIRE

    FRANZ, Gérald; ABED-MERAIM, Farid; BEN ZINEB, Tarak; LEMOINE, Xavier; Berveiller, Marcel

    2009-01-01

    The development of a relevant constitutive model adapted to sheet metal forming simulations requires an accurate description of the most important sources of anisotropy, i.e. the slip processes, the intragranular substructure changes and the texture development. During plastic deformation of thin metallic sheets, strain-path changes often occur in the material resulting in macroscopic effects. These softening/hardening effects must be correctly predicted because they can significantly influen...

  18. THE EFFECT OF DIFFERENT PROBIOTIC STRAINS ON FATTENINTHE EFFECT OF DIFFERENT PROBIOTIC STRAINS ON F

    Directory of Open Access Journals (Sweden)

    Cyril Hrnčár

    2013-02-01

    Full Text Available The aim of this work was to verify the effect of different probiotic strains applied through a drinking water source to fattening and carcass parameters of broiler ducks. Fattening experiment was realised in half-operating conditions of experimental basis of Department of Poultry Science and Small Animal Husbandry in three-floor cage technology. Totally 90 broiler duck were divided to three groups. Experimental group 1 (n=30 received probiotic strain Lactobacillus fermentum CCM 7158 with concentration of 1x109 colony forming units (CFU in drinking water daily addition of 0.90 g day 1 to day 56 of fattening. Experimental group 2 (n=30 received probiotic strain Enterococcus faecium M 74 with concentration of 1x109 colony forming units (CFU in drinking water daily addition of 0.45 g day 1 to day 56 of fattening. The control group of birds (n=30 received water without any probiotics. The supplementation of probiotic strains Lactobacillus fermentum and Enterococcus faecium no significant affected (P≥0.05 final body weight, feed consumption and mortality of broiler ducks. From carcass parameters, we recorded statistically significant (P<0.05 reduction in weight of abdominal fat of broiler ducks for application of tested probiotic strains.

  19. Superplastic blow forming of 2219 aluminium alloy

    Energy Technology Data Exchange (ETDEWEB)

    Kaibyshev, R.; Kazakulov, I.; Gromov, D. [Inst. for Metals Superplasticity Problems, Ufa (Russian Federation); Lesuer, D.R.; Nieh, T.G. [Lawrence Livermore National Lab., Livermore, CA (United States)

    2004-07-01

    Superplasticity in 2219 aluminum alloy was achieved through thermomechanical processing. Tension tests showed that the alloy exhibits superplastic behavior in the temperature range of 450-540 C and strain rates ranging from 2.2 x 10{sup -5} to 1.1 x 10{sup -1} s{sup -1}. A maximum elongation-to-failure of 670% was recorded at 500 C and at the initial strain rate of 2.2 x 10{sup -4} s{sup -1}. High cavitation level and intensive grain growth were observed. Sheet of the 2219 aluminum alloy was blow formed into conical shape using two different methods: simple negative and backpressure forming. A strain of 2.1 was obtained at 500 C under the backpressure blow forming condition. It was found that elongation to failure under blow forming with backpressure is about 1.5 times higher than that under a simple female forming. Microstructural evolution of blow formed parts was also examined. (orig.)

  20. MEMS Resonant Strain Sensor Integration

    OpenAIRE

    Myers, David Richard

    2010-01-01

    Despite commercial availability since the 1950's, silicon strain sensors have not experienced the same success as other microdevices, such as accelerometers, pressure sensors, and inkjet heads. Strain sensors measure mechanical deformation and could be used in many structural components, improving safety, controls, and manufacturing tolerances. This thesis examines major strain sensing techniques and highlights both advantages and disadvantages of each. MEMS resonant strain gauges are iden...

  1. Reliable strain measurement in transistor arrays by robust scanning transmission electron microscopy

    Directory of Open Access Journals (Sweden)

    Suhyun Kim

    2013-09-01

    Full Text Available Accurate measurement of the strain field in the channels of transistor arrays is critical for strain engineering in modern electronic devices. We applied atomic-resolution high-angle annular dark-field scanning transmission electron microscopy to quantitative measurement of the strain field in transistor arrays. The quantitative strain profile over 20 transistors was obtained with high reliability and a precision of 0.1%. The strain field was found to form homogeneously in the channels of the transistor arrays. Furthermore, strain relaxation due to the thin foil effect was quantitatively investigated for thicknesses of 35 to 275 nm.

  2. Strain calibration of optical FBG-based strain sensors

    Science.gov (United States)

    Roths, Johannes; Wilfert, Andre; Kratzer, Peter; Jülich, Florian; Kuttler, Rolf

    2010-09-01

    A facility for strain sensitivity calibration of optical FBG-based strain sensors according to the German VDI/VDE 2660 guideline was established and characterized. Statistical analysis of several calibration measurement series performed with one single type of FBG strain sensor and application technique showed a reproducibility of 0.15%. Strain sensitivities for FBGs inscribed in two different types of optical fibres (GF1B and PR2008) showed significantly different strain sensitivities of k = 0.7885+/-0.0026 and k = 0.7758+/-0.0024, respectively.

  3. Protective Effect of Dual-Strain Probiotics in Preterm Infants: A Multi-Center Time Series Analysis

    Science.gov (United States)

    Schwab, Frank; Garten, Lars; Geffers, Christine; Gastmeier, Petra; Piening, Brar

    2016-01-01

    Objective To determine the effect of dual-strain probiotics on the development of necrotizing enterocolitis (NEC), mortality and nosocomial bloodstream infections (BSI) in preterm infants in German neonatal intensive care units (NICUs). Design A multi-center interrupted time series analysis. Setting 44 German NICUs with routine use of dual-strain probiotics on neonatal ward level. Patients Preterm infants documented by NEO-KISS, the German surveillance system for nosocomial infections in preterm infants with birth weights below 1,500 g, between 2004 and 2014. Intervention Routine use of dual-strain probiotics containing Lactobacillus acidophilus and Bifidobacterium spp. (Infloran) on the neonatal ward level. Main outcome measures Incidences of NEC, overall mortality, mortality following NEC and nosocomial BSI. Results Data from 10,890 preterm infants in 44 neonatal wards was included in this study. Incidences of NEC and BSI were 2.5% (n = 274) and 15.0%, (n = 1631), respectively. Mortality rate was 6.1% (n = 665). The use of dual-strain probiotics significantly reduced the risk of NEC (HR = 0.48; 95% CI = 0.38–0.62), overall mortality (HR = 0.60, 95% CI = 0.44–0.83), mortality after NEC (HR = 0.51, 95% CI = 0.26–0.999) and nosocomial BSI (HR = 0.89, 95% CI = 0.81–0.98). These effects were even more pronounced in the subgroup analysis of preterm infants with birth weights below 1,000 g. Conclusion In order to reduce NEC and mortality in preterm infants, it is advisable to add routine prophylaxis with dual-strain probiotics to clinical practice in neonatal wards. PMID:27332554

  4. Precision determination of strains by strain measurement method

    International Nuclear Information System (INIS)

    Method for precision strain measurement determination of strains measurement determination of strains by direct measurement of the resistance of strain gauge resistors put on the sample, by constant current bridge MOD-61 of 0.05 class using a zero method by single bridge double-clamp circuit is described. Strain measurement technique was used to investigate residual stresses in tubular samples. Sample external diameter made up 30 mm, the length - 180, the wall thickness-11 mm. To evaluate the method sensitivity, annealed samples were investigated (annealing temperature-850-880 deg C, hold-up-2 h, cooling in the furnace). It is ascertained, that the method provides for 0.3-0.5 μm strain measurement accuracy even if sample strains do not exceed 3.0-3.6 μm and correspond to residual stress level of no more than 20 MPa

  5. Characterization of new radioresistant strains of Chlamydomonas reinhardtii

    International Nuclear Information System (INIS)

    The purpose of this work is to investigate 4 new mutant strains of Chlamydomonas reinhardtii induced in respect to their radioresistance at different levels: cellular, molecular and biochemical. A comparison between radioresistance of the strains, DNA-ssb repair activity and pigment contents (chl 'a', chl 'b' and carotenoids) is made. Strain 137C(+) and mutant strains GK-1(+), GK-2(+), GK-3(+), and AKK-9-9(-) are used. The radioresistance has been assessed according to colony forming ability of the strains after irradiation with gamma rays (60C0, I=12.4 rads-1 doses 10, 50, 100, 150, 200 and 250 Gy). The data obtained reveal that there is a relationship between radioresistance, DNA-ssb repair efficiency and plastid pigment content in the tested Chlamydomonas reinhardtii strains. This relationship is most pronounced in strain AK-9-9 which displays the highest level of radioresistance. On the basis of data obtained the authors propose mutant strain AK-9-9 to be included in the existing collection of mutant strains of Chlamydomonas reinhardtii

  6. Similarly Lethal Strains of Extraintestinal Pathogenic Escherichia coli Trigger Markedly Diverse Host Responses in a Zebrafish Model of Sepsis.

    Science.gov (United States)

    Barber, Amelia E; Fleming, Brittany A; Mulvey, Matthew A

    2016-01-01

    In individuals with sepsis, the infecting microbes are commonly viewed as generic inducers of inflammation while the host background is considered the primary variable affecting disease progression and outcome. To study the effects of bacterial strain differences on the maladaptive immune responses that are induced during sepsis, we employed a novel zebrafish embryo infection model using extraintestinal pathogenic Escherichia coli (ExPEC) isolates. These genetically diverse pathogens are a leading cause of sepsis and are becoming increasingly dangerous because of the rise of multidrug-resistant strains. Zebrafish infected with ExPEC isolates exhibit many of the pathophysiological features seen in septic human patients, including dysregulated inflammatory responses (cytokine storms), tachycardia, endothelial leakage, and progressive edema. However, only a limited subset of ExPEC isolates can trigger a sepsis-like state and death of the host when introduced into the bloodstream. Mirroring the situation in human patients, antibiotic therapy reduced ExPEC titers and improved host survival rates but was only effective within limited time frames that varied, depending on the infecting pathogen. Intriguingly, we find that phylogenetically distant but similarly lethal ExPEC isolates can stimulate markedly different host transcriptional responses, including disparate levels of inflammatory mediators. These differences correlate with the amounts of bacterial flagellin expression during infection, as well as differential activation of Toll-like receptor 5 by discrete flagellar serotypes. Altogether, this work establishes zebrafish as a relevant model of key aspects of human sepsis and highlights the ability of genetically distinct ExPEC isolates to induce divergent host responses independently of baseline host attributes. IMPORTANCE Sepsis is a life-threatening systemic inflammatory condition that is initiated by the presence of microorganisms in the bloodstream. In the

  7. Effects of Substrate Local Strain on Microstructure of Electrodeposited Aluminum Film

    Institute of Scientific and Technical Information of China (English)

    TAN Yuehua; YAN Bo; GAO Ge; YANG Yuxin

    2006-01-01

    The aluminum coating layer was formed on a copper substrate with local strain region by using the electrodeposited method. It was found that the particle shape of the coating deposited on the copper substrate is very sensitive to the strain extent of substrate. The large needle-like aluminum particles were observed on the substrate region with large local strain, indicating that substrate local strain may affect the shape of the deposited particles and promote the nucleation and growth of the deposited particles.

  8. Palladium-chromium static strain gage for high temperature propulsion systems

    Science.gov (United States)

    Lei, Jih-Fen

    1991-01-01

    The present electrical strain gage for high temperature static strain measurements is in its fine-wire and thin-film forms designed to be temperature-compensated on any substrate material. The gage element is of Pd-Cr alloy, while the compensator is of Pt. Because the thermally-induced apparent strain of this compensated wire strain gage is sufficiently small, with good reproducibility between thermal cycles to 800 C, output figures can be corrected within a reasonable margin of error.

  9. The influence of the strain on springback of cold drawn alloy CuCrZr

    OpenAIRE

    Gusel, Leo

    2015-01-01

    During the deformation of metals at lower temperatures, the yield stress increases with increasing strain. This phenomenon is called strain hardening. As a result of strain hardening, there is an increase in the strength values of the finished components through forming which is very desirable. The strain hardening has also a great influence on the elastic springback rataio and the springback angle. Control of springback for the bending process applied in practice is difficult for number of r...

  10. Comparison of barley stripe mosaic virus strains.

    Science.gov (United States)

    Hafez, Elsayed E; Abdel Aleem, Engy E; Fattouh, Faiza A

    2008-01-01

    BSMV (barley stripe mosaic virus) particles were obtained in a pure state from infected host plant tissues of Hordeum vulgare. The three genomic parities (alpha, beta and gamma) were amplified by PCR using specific primers for each particle; each was cloned. Partial sequence of the alpha, beta and gamma segments was determined for the Egyptian isolate of barley stripe mosaic virus (BSMV AE1). Alignment of nucleotide sequences with that of other known strains of the virus, BSMV type strains (CV17, ND18 and China), and the generation of phylogenetic trees was performed. A low level of homology was detected comparing 467 bp of the a and 643 bp of the segments to that of the other strains, and thus BSMV alpha and beta segments were in separate clusters. However, 1154 bp of the gamma segments of BSMV AE1 showed a high level of homology especially to strain BSMV ND18, as they both formed a distinct cluster. Northern blotting of pure BSMV AE1 virus and H. vulgare-infected tissue were compared using an alpha ND18 specific probe. Western blotting using antibodies specific for the coat protein (CP) and the triple gene block 1 (TGB1) protein, which are both encoded by the beta ND18 segment, still indicated a high level of similarity between proteins produced by BSMV ND18 and AE1. We suggest that the BSMV AE1 isolate is a distinct strain of BSMV which reflects the genetic evolutionary divergence among BSMV strains and members of the Hordeivirus group. PMID:18533473

  11. THE STUDY OF RESISTENCE OF STAPHYLOCOCCUS AUREUS STRAINS TO ANTIMICROBIALS

    Directory of Open Access Journals (Sweden)

    Nazarchuk GG

    2012-12-01

    Full Text Available In the research work the results of the study of resistance forming to antibiotics, antiseptics and decametoxine composition with modified polysaccharides in S.aureus strains are presented. The development of resistance to penicillins, cephalosporins, glycopeptides, macrolides is shown. Slow forming of resistance to decasan and decametoxine composition with carboxymethylamylum, oxyethylcellulose was determined.

  12. Development of reversible strain gage

    International Nuclear Information System (INIS)

    A high-temperature strain gage which can be peeled after taking required apparent strain measurements in a furnace and can be attached reverse-side-up at the point of interest on a test structure was developed. Using the ''reversible'' strain gage with selected room-temperature curing type polyester adhesive, one can expect to measure thermal strain accurately, especially for on large structures, at the first test in temperature up to 250 deg C. The repeatability of apparent strains for about 100 reversible gages was within 50 microstrains of difference at 250 deg C (within 30 microstrains of difference for 80 % of the test gages). (author)

  13. Risk Factors and interventions for bloodstream infections after cardiac interventional therapy%心脏介入术后血管相关性血流感染因素分析及干预对策

    Institute of Scientific and Technical Information of China (English)

    赵雪芳; 狄韵漫

    2012-01-01

    目的 探讨心脏介入手术后发生中心静脉相关性血流感染因素及干预对策.方法 对心脏介入手术患者进行目标性临测及导管室的管理监控,分析、干预和总结感染因素.结果 通过开展目标性监测及干预对策,中心静脉导管相关性血流感染的感染率由开展前的1.9%下降为0,差异有统计学意义(P<0.01).结论 加强导管室管理,对介入手术进行监测和感染因素的干预,是预防心脏介入手术发生中心静脉导管相关性血流感染的有效方法.%OBJECTIVE To explore risk factors and intervention countermeasures for central venous catheter-related bloodstream infections after cardiac interventional therapy. METHODS By carrying out targeted surveillance in cardiac interventional therapy and monitoring of catheterization lab, the risk factors for the infections were analyzed, intervened, and summarized. RESULTS The incidence of the central venous catheter-related infections dropped from 1. 9% to 0 after the targeted surveillance and intervention countermeasures, and the difference was statistically significant (P<0. 01). CONCLUSION To strengthen the management of cauterization lab, monitor the interventional surgery, and intervene in the risk factors are effective ways to prevent central venous catheter-related bloodstream infections after cardiac interventional therapy.

  14. [Echinococcus and strain concepts].

    Science.gov (United States)

    Utük, Armağan Erdem; Simsek, Sami

    2008-01-01

    Hydatid disease (echinococcosis) is one of the most important parasitic zoonoses and remains a public health and economic problem all over the world. Echinococcus granulosus includes a number of genetic variants and, up to date, analyses of mitochondrial DNA sequences have identified ten distinct genetic types (genotypes G1-10). This categorization follows closely the pattern of strain variation emerging based on biological characteristics. The extensive variation in E. granulosus may influence life-cycle patterns, host specificity, development rate, antigenicity, transmission dynamics, sensitivity to chemotherapeutic agents, and pathology. In this review, the recent genetic characterizations of Echinococcus genus have been summarized. PMID:18351549

  15. Asymptomatic bacteriuria Escherichia coli strains

    DEFF Research Database (Denmark)

    Hancock, Viktoria; Nielsen, E.M.; Klemm, Per

    2006-01-01

    Urinary tract infections (UTIs) affect millions of people each year. Escherichia coli is the most common organism associated with asymptomatic bacteriuria (ABU) in humans. Persons affected by ABU may carry a particular E. coli strain for extended periods of time without any symptoms. In contrast to...... uropathogenic E. coli (UPEC) that cause symptomatic UTI, very little is known about the mechanisms by which these strains colonize the urinary tract. Here, we have investigated the growth characteristics in human urine as well as adhesin repertoire of nine ABU strains; the ability of ABU strains to compete...... against the UPEC strain CFT073 was also studied. The different ABU strains displayed a wide variety of the measured characteristics. Half of the ABU strains displayed functional type 1 fimbriae while only one expressed functional P fimbriae. A good correlation between the growth rate of a particular...

  16. Reconstruction of axisymmetric strain distributions via neutron strain tomography

    International Nuclear Information System (INIS)

    Predicting the behaviour of structural components under a particular set of loading conditions requires knowledge of the residual elastic strain distribution throughout the bulk of these components. Characterising the 3D strain state at any particular point involves the measurement of six independent components which make up the second order strain tensor. Mapping the complete strain distribution throughout large volumes thus presents significant practical challenges. One possible solution to this problem is to reconstruct the 3D variation of strain components using tomographic techniques. The basic principle underpinning this idea is that the multi-component strain tensor can be reconstructed from a redundant set of lower order projection data. Here we demonstrate this fundamental concept for two samples: a shrink fit ‘ring-and-plug’ sample, and a spray-quenched circular cylinder, both possessing axially symmetric internal strain distribution. We present and contrast different approaches to the strain tomography problem. The methods described here can also be readily applied to high-energy X-ray diffraction measurements and represent an important step toward developing the tomographic reconstruction framework for strain tensor distributions of arbitrary complexity. The major benefit of neutron strain tomography is that the incident beam flux is utilised more fully, greatly reducing the data collection times. Using micro-channel plate (MCP) neutron detectors, a spatial resolution of the order of 0.1 mm can be achieved .

  17. [Specification of species status of some colleciton strains of methanotrophs].

    Science.gov (United States)

    Romanovskaia, V A; Rokitko, P V; Shilin, S O; Chernaia, N A

    2009-01-01

    Sequence-analysis of genes 16S rRNA has demonstrated the high-level relationship (99%) of the strains Methylobacter ucrainicus UCM B-3159, and Methylobacter marinus A45(T). The strain UCM B-3159 has lower coefficients of similarity (97.4-96.4%) for other species of that genus. These strains are similar as to their phenotypical properties and form one branch on the dendrogram which demonstrates species relations of Methylococcaceae family, that permitted reclassifying M. ucrainicus as M. marinus. Phylogenetic analysis has confirmed the belonging of strains UCM B-3002 and UCM B-3494 to Methylococcus capsulatus species. Those strains were earlier related to this species on the basis of phenotype features. PMID:19663320

  18. Physiology and behavior of Pseudomonas fluorescens single and dual strain biofilms under diverse hydrodynamics stresses

    OpenAIRE

    Simões, M.; Simões, Lúcia C.; Vieira, M. J.

    2008-01-01

    Three selected Pseudomonas fluorescens strains (the type strain and two strains originally isolated from a dairy processing plant—D3-348 and D3-350)were used to form turbulent and laminar flow-generated biofilms under laboratorial conditions using flowcell reactors with stainless steel substrata. TheD3-348 and D3-350 strainswere also used to form dual biofilms. Biofilm phenotypic characteristics, such as respiratory activity, total and culturable cells, biomass, total and matrix p...

  19. Interface strain transfer mechanism and error modification for adhered FBG strain sensor

    Science.gov (United States)

    Li, Jilong; Zhou, Zhi; Ou, Jinping

    2005-06-01

    The application of adhered FBG strain sensor is affected by interface strain transfer and error modification. In his paper, firstly, based on the characterstics of forces and damage, the fundamental hupotheses are given, and the general expression of interface transferring mechanism is derived. After that, united form of the characteristic value-λ for the general equation is geven for the multi-layer coatings. Finally, according to the error-modified equation of adhered FBG sensor, the relationships the error rate η against the shear modulus and the thckness of the glue are given. With regard to the glue applied in engineering (thickness is from 4mm to 60mm, shear modulus is from 30MPa to 200MPa), the error rate η is about 5~10%, and the correction coefficient k is about 1.05~1.11. Hence, the error modification must be considered when adhered FBG strain sensors are used in civil engineering.

  20. Laser Welding of Sub-assemblies before Forming

    DEFF Research Database (Denmark)

    Rasmussen, Mads; Olsen, Flemmming Ove; Pecas, Paulo

    1996-01-01

    This paper describes some experimental investigations of the formability of CO2-laser-welded 0.75 mm and 1.25 mm low carbon steel. There will be a description of how the laser welded blanks behave in different forming tests, and the influene of misalignment and undercut on the formability. The...... quality is evalutated by measuring the imit strain and the limit effective strain for the laser welded sheets and the base material. These strains will be presented in a forming limit diagram (FLD). Finally the formability of the laser sheets is compared to that of the base materials....

  1. Strain Engineering Water Transport in Graphene Nano-channels

    OpenAIRE

    Xiong, Wei; Liu, Jefferson Zhe; Ma, Ming; Xu, Zhiping; Sheridan, John; Zheng, Quanshui

    2011-01-01

    Using equilibrium and non-equilibrium molecular dynamic (MD) simulations, we found that engineering the strain on the graphene planes forming a channel can drastically change the interfacial friction of water transport through it. There is a sixfold change of interfacial friction stress when the strain changes from -10% to 10%. Stretching the graphene walls increases the interfacial shear stress, while compressing the graphene walls reduces it. Detailed analysis of the molecular structure rev...

  2. Residual strain effects on large aspect ratio micro-diaphragms

    Energy Technology Data Exchange (ETDEWEB)

    Hijab, R.S.; Muller, R.S. (California Univ., Berkeley, CA (USA))

    1988-09-30

    Highly compliant, large aspect ratio diaphragms for use in low-pressure, capacitive-readout sensors, have been investigated. In such structures, unrelaxed strain in the diaphragms can radically alter mechanical behavior. Although strain can be reduced by thermal annealing, it usually reaches a remnant irreducible minimum. The purpose of this paper is to describe techniques that result in low-strain materials and that reduce the effects of residual strain in micro-diaphragms. Square polysilicon grilles and perforated diaphragms made from both single and double polysilicon layers and from single-crystal silicon, with aspect ratios (side/thickness) of up to 1000 and very low compressive strain ({approx}6 {times} 10{sup {minus}5}), have been fabricated. Strain reduction is achieved by combining thermal annealing with one of two mechanical design techniques. The first technique makes use of a series of cantilever beams to support the diaphragms. In a second procedure, corrugated surfaces in thinned membranes of single-crystal silicon are formed. The corrugations result from the use of boron doping and anisotropic silicon etching. In both of these techniques to produce low-strain diaphragms, an etched cavity is purposely formed in the substrate crystal below them. Only one-sided processing of wafers is employed, thus aiding reproducibility and providing ease of compatibility with an MOS process. A fast-etching sacrificial-support layer (phosphorus-doped CVD oxide) is used. 4 refs., 10 figs.

  3. Modular Forms and Weierstrass Mock Modular Forms

    Directory of Open Access Journals (Sweden)

    Amanda Clemm

    2016-02-01

    Full Text Available Alfes, Griffin, Ono, and Rolen have shown that the harmonic Maass forms arising from Weierstrass ζ-functions associated to modular elliptic curves “encode” the vanishing and nonvanishing for central values and derivatives of twisted Hasse-Weil L-functions for elliptic curves. Previously, Martin and Ono proved that there are exactly five weight 2 newforms with complex multiplication that are eta-quotients. In this paper, we construct a canonical harmonic Maass form for these five curves with complex multiplication. The holomorphic part of this harmonic Maass form arises from the Weierstrass ζ-function and is referred to as the Weierstrass mock modular form. We prove that the Weierstrass mock modular form for these five curves is itself an eta-quotient or a twist of one. Using this construction, we also obtain p-adic formulas for the corresponding weight 2 newform using Atkin’s U-operator.

  4. Strain relief of heteroepitaxial bcc-Fe(001) films

    OpenAIRE

    Wedler, G.; Schneider, C. M.; Trampert, A.; Koch, R.

    2004-01-01

    The strain relief of heteroepitaxial bcc-Fe(001) films, deposited at 520-570 K onto MgO(001), has been investigated by scanning tunneling microscopy. In accordance with real-time stress measurements, the tensile misfit strain is relieved during coalescence of flat, mainly 2-3 monolayers (ML) high Fe islands at the high thickness of similar to20 ML. To accommodate the misfit between merging strain-relaxed islands, a network of 1/2[111] screw dislocations is formed. A strong barrier for disloca...

  5. Dielectric-waveguide strain gauge: a theoretical study

    International Nuclear Information System (INIS)

    We present a theoretical analysis of the strain dependence of bend loss from a multimode slab dielectric waveguide formed in the shape of an arc of a circle. This dependence suggests its use as a strain gauge. We calculate the strain sensitivity of this gauge as a function of the core-cladding index difference, bend radius, and arc angle. The method that we use is a geometrical-optics analysis modified to account for the curvature of the boundary between the core and the cladding

  6. Electroweak form factors

    International Nuclear Information System (INIS)

    The present status of electroweak nucleon form factors and the N - Δ transition form factors is reviewed. Particularly the determination of dipole mass MA in the axial vector form factor is discussed

  7. Enterococcus faecium strains characterization through polymorphism study of VNTR loci

    Directory of Open Access Journals (Sweden)

    Belteghi, C.,

    2008-12-01

    Full Text Available Enterococci are commensally bacteria of the gastrointestinal and female genital tract in humans and some mammals and birds, and one of the significant causes of hospital-acquired infections, especially in immuno-compromised patients. Genetic fingerprinting (DNA fingerprinting is a tool for identifying, marking and prevention of infectious agents dissemination. SSR (short sequence repeat are known to suffer frequent variations in the number of repetitive units.MLVA (multiple locus variable number tandem repeats analysis is a variant of genetic fingerprinting, in epidemiological studies on the pathogenetic Enterococcus faecium. Our study included laboratory Enterococcus faecium strains or isolated from clinical cases or from the environment (2003-2008. All analyzed strains of Enterococcus faecium were sensitive to vancomycin, except BM4147, and resistant to oxacilin. Strains isolated from the birds’ samples have shown a smaller resistance profile than those of human origin. 33 Enterococus faecium strains were analyzed by PCR amplification. 27 MT (VNTR profiles were obtained: six in the case of the strains isolated from birds, 15 in the case of the strains isolated form humans, 4 in the case of the collection strains and 2 in the case of the strains isolated from water samples. Among the strains isolated from humans and those isolated from animals, identical profiles were not recorded. Within the strains isolated from clinical cases, and those isolated from birds, circulating genotypes were noted, which can be considered as epidemical. The strains used as probiotics proved to be different from those circulating in birds. All MLVA profiles codes compared with those published on line in the UMC Utrecht database proved to be different. Results obtained in this study support the usefulness of the polymorphic VNTR analysis, as genetic marker, inepidemiological investigations.

  8. Osmotic stress tolerance, PGP traits and RAPD analysis of Bradyrhizobium japonicum strains

    Directory of Open Access Journals (Sweden)

    Marinković Jelena

    2013-01-01

    Full Text Available The osmotic stress tolerance of B. japonicum strains assessed according to their persistence in PEG solution. The lowest tolerance to osmotic stress was observed in strain 511 (43.3%, and the highest tolerance was observed for strain D216 (3.3% growth reduction in presence of PEG. PGP traits of B. japonicum strains were tested. None of five B. japonicum strains produced siderophore, strains 511 and 518 had the urease ability, and only B. japonicum 518 strain showed the ability to solubilize insoluble tricalcium phosphate. RAPD analysis, using AP10, BC318, AF14 and SPH1 primers, indicated genetic differences between Bradyrhizobium strains. The first group (strains 3, 6 and 518 showed more than 80% similarity. Strains 511 and D216 formed separate clusters. Difference between strains D216 and the other strains were more than 60%, with maximum value of 72% in comparison with strain 511. Plant-growth promoting (PGP traits, osmotic stress tolerance and RAPD analysis highlighted strain D216 as useful for further investigation of B. japonicum impact on drought reduction in symbiosis with soybean. [Projekat Ministarstva nauke Republike Srbije, br. TR 31022 i br. TR 31072

  9. EFFECT OF CREEP STRAIN INDUCED BY THERMAL AND RADIATION IMPACT ON STRESS-STRAIN CONDITION OF BODIES WITH CYLINDRICAL GEOMETRY

    Directory of Open Access Journals (Sweden)

    I. S. Kulikov

    2010-01-01

    Full Text Available The paper considers peculiar features of stress-strain condition of nuclear reactor active zone elements which are under an influence of high temperature and neutron irradiation with due account of thermal and radiation creepage taking jackets of heat releasing elements in the form of hollow thick-walled cylinder as an example. The numerical results of stresses  and deformations which have been obtained with the account of creep strain and without it are presented in the paper.

  10. Towards quantification of the interplay between strain weakening and strain localisation in granular material

    Science.gov (United States)

    Ritter, Malte C.; Rosenau, Matthias; Leever, Karen; Oncken, Onno

    2014-05-01

    Strain weakening is the major agent of localisation of deformation into shear zones and faults at various scales in brittle media. Physical analogue models using granular material are especially apt to investigate both phenomena, because they are able to reproduce them without the need of any assumptions concerning the physics behind. Several attempts have been made to quantify either strain weakening (e. g. Lohrmann et al., 2003, using Ring-Shear tests) or strain localisation (e. g. Schrank et al., 2008, using a variation of the classical Riedel-experiment). While Ring-Shear tests yield excellent data on strain weakening through measuring shear stress during localisation, they do not allow monitoring the process of strain localisation in-situ because of experimental inaccessibility of the small scale kinematics. In Riedel-type strike-slip experiments, on the other hand, no direct measurements of shear stresses have been available so far. Furthermore, they contain a strong boundary condition in form of a pre-defined linear discontinuity at the base. This forces the formation of Riedel-Shears, i. e. a complex fault system, that makes it difficult to define strain localisation on single faults. We developed a new experimental set-up, in which the formation of a strike-slip shear zone in granular material is induced using an ndenter with stress and strain monitored at high accuracy and resolution. In a first set of experiments we used a horizontal sand layer indented by a vertical wall. The sand layer is laterally unconfined and rests on low-viscosity silicone oil in order to minimize basal shear strength. Compared to the Riedel experiments, this avoids the boundary condition of a pre-existing basal discontinuity allowing one single, hrough-going shear crack to form and propagate. The indenter moves at a constant rate and is equipped with a force sensor that measures the applied push, which integrates over shear stresses along the fault and the base of the sand pack

  11. Cavitation and grain growth during superplastic forming

    Directory of Open Access Journals (Sweden)

    M.J. Tan

    2007-09-01

    Full Text Available Purpose: The purpose of the paper is to study the cavitation and grain growth during superplastic forming.Design/methodology/approach: Superplastic alloys exhibit the extremely large elongation to failure by their high strain rate sensitivity. Cavities have widely been observed during superplastic deformation of metals and alloys and lead to the degradation of material properties such as tensile, creep, fatigue and stress-corrosion behavior. In this work, a finite element method is developed, which considers the grain growth and the effect of material damage.Findings: The effects of material parameters and deformation damage on the superplastic deformation process are numerically analyzed, and the means to control cavitation growth is discussed. The microstructural mechanism of grain growth during superplastic deformation is also studied. A new model considering the grain growth is proposed and applied to conventional superplastic materials The relationships between the strain, the strain rate, the test temperature, the initial grain size and the grain growth respectively in superplastic materials are discussed.Practical implications: The effect of variation of strain rate sensitivity (m value on the strain limit of the superplastic deformation is investigated, and the theoretically calculated values are compared with the experimental results.Originality/value: A new microstructure model based on the microstructural mechanism of superplastic deformation has been proposed. This model has been successfully applied to analyze conventional superplastic materials.

  12. Strain in silicon nanowire beams

    Science.gov (United States)

    Ureña, Ferran; Olsen, Sarah H.; Šiller, Lidija; Bhaskar, Umesh; Pardoen, Thomas; Raskin, Jean-Pierre

    2012-12-01

    In this work, strain in silicon free standing beams loaded in uniaxial tension is experimentally and theoretically investigated for strain values ranging from 0 to 3.6%. The fabrication method allows multiple geometries (and thus strain values) to be processed simultaneously on the same wafer while being studied independently. An excellent agreement of strain determined by two non-destructive characterization techniques, Raman spectroscopy and mechanical displacement using scanning electron microscopy (SEM) markers, is found for all the sample lengths and widths. The measured data also show good agreement with theoretical predictions of strain based upon continuum mechanical considerations, giving validity to both measurement techniques for the entire range of strain values. The dependence of Young's modulus and fracture strain on size has also been analyzed. The Young's modulus is determined using SEM and compared with that obtained by resonance-based methods. Both methods produced a Young's modulus value close to that of bulk silicon with values obtained by resonance-based methods being slightly lower. Fracture strain is analyzed in 40 sets of samples with different beam geometries, yielding values up to 3.6%. The increase in fracture strain with decreasing beam width is compared with previous reports. Finally, the role of the surface on the mechanical properties is analyzed using UV and visible lasers having different penetration depths in silicon. The observed dependence of Raman shift on laser wavelength is used to assess the thermal conductivity of deformed silicon.

  13. Asymptomatic bacteriuria Escherichia coli strains

    DEFF Research Database (Denmark)

    Hancock, Viktoria; Nielsen, E.M.; Klemm, Per

    2006-01-01

    Urinary tract infections (UTIs) affect millions of people each year. Escherichia coli is the most common organism associated with asymptomatic bacteriuria (ABU) in humans. Persons affected by ABU may carry a particular E. coli strain for extended periods of time without any symptoms. In contrast to...... uropathogenic E. coli (UPEC) that cause symptomatic UTI, very little is known about the mechanisms by which these strains colonize the urinary tract. Here, we have investigated the growth characteristics in human urine as well as adhesin repertoire of nine ABU strains; the ability of ABU strains to compete...

  14. Bacteria form tellurium nanocrystals

    Science.gov (United States)

    Oremland, R.S.

    2007-01-01

    A team of researchers have found two bacterial species that produce tellurium oxyanions as respiratory electron acceptors for growth, leaving elemental tellurium in the form of nanoparticles. The crystals from the two organisms exhibit distinctively different structures. Bacillus selenitireducens initially forms nanorods that cluster together to form rosettes. Sulfurospirillum barnesii forms irregularly-shaped nanospheres that coalesce into larger composite aggregates.

  15. Adaptive municipal electronic forms

    NARCIS (Netherlands)

    Kuiper, Pieter; Dijk, van Betsy; Bondarouk, Tanya; Ruël, Huub; Guiderdoni-Jourdain, Karine; Oiry, Ewan

    2009-01-01

    Adaptation of electronic forms (e-forms) seems to be a step forward to reduce the burden for people who fill in forms. Municipalities more and more offer e-forms online that can be used by citizens to request a municipal product or service or by municipal employees to place a request on behalf of a

  16. Will the swine strain crowd out the seasonal influenza strain?

    CERN Document Server

    Schinazi, Rinaldo B

    2010-01-01

    We use spatial and non spatial models to argue that competition alone may explain why two influenza strains do not usually coexist. The more virulent strain is likely to crowd out the less virulent one. This can be seen as a consequence of the Exclusion Principle of Ecology. We exhibit, however, a spatial model for which coexistence is possible.

  17. Tissue Velocity, Strain und Strain Rate bei Hunden mit Mitralklappenendokardiose

    OpenAIRE

    Javornik, Ana

    2007-01-01

    In der vorliegenden Arbeit „Tissue Velocity, Strain und Strain Rate bei Hunden mit Mitralklappenendokardiose“ wurden erstmals die Geschwindigkeits- und Verformungsparameter zur Evaluierung von Hunden mit Mitralklappenendokardiose angewendet. Diese erweisen sich als neue und viel versprechende Möglichkeiten zur Quantifizierung der regionalen Myokardfunktion. Die myokardialen Funktionsparameter finden in der Humanmedizin weit verbreitete Anwendung und auch in der Tiermedizin erlangen sie zunehm...

  18. 3D strain measurement in electronic devices using through-focal annular dark-field imaging

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Suhyun; Jung, Younheum; Lee, Sungho; Jung Kim, Joong; Byun, Gwangseon; Lee, Sunyoung; Lee, Haebum

    2014-11-15

    Spherical aberration correction in high-angle annular dark-field scanning transmission electron microscopy (HAADF-STEM) allows us to form an electron probe with reduced depth of field. Using through-focal HAADF imaging, we experimentally demonstrated 3D strain measurement in a strained-channel transistor. The strain field distribution in the channel region was obtained by scanning an electron beam over a plan-view specimen. Furthermore, the decrease in the strain fields toward the silicon substrate was revealed at different focal planes with a 5-nm focal step. These results demonstrate that it is possible to reconstruct the 3D strain field in electronic devices. - Highlights: • Three dimensional strain fields were measured using through-focal HAADF-STEM series. • The technique was applied to the channel of a plan-view strained-silicon device. • The strain values agreed with the results obtained using cross-section specimen.

  19. Manufacturing processes 4 forming

    CERN Document Server

    Klocke, Fritz

    2013-01-01

    This book provides essential information on metal forming, utilizing a practical distinction between bulk and sheet metal forming. In the field of bulk forming, it examines processes of cold, warm and hot bulk forming, as well as rolling and a new addition, the process of thixoforming. As for the field of sheet metal working, on the one hand it deals with sheet metal forming processes (deep drawing, flange forming, stretch drawing, metal spinning and bending). In terms of special processes, the chapters on internal high-pressure forming and high rate forming have been revised and refined. On the other, the book elucidates and presents the state of the art in sheet metal separation processes (shearing and fineblanking). Furthermore, joining by forming has been added to the new edition as a new chapter describing mechanical methods for joining sheet metals. The new chapter “Basic Principles” addresses both sheet metal and bulk forming, in addition to metal physics, plastomechanics and computational basics; ...

  20. TL transgenic mouse strains

    International Nuclear Information System (INIS)

    As a result of abnormal development of the thymus of these mice, TCR αβ lineage of the T cell differentiation is disturbed and cells belonging to the TCR γδ CD4- CD8- double negative (DN) lineage become preponderant. The γδ DN cells migrate into peripheral lymphoid organs and constitute nearly 50% of peripheral T cells. Immune function of the transgenic mice is severely impaired, indicating that the γδ cells are incapable of participating in these reactions. Molecular and serological analyses of T-cell lymphomas reveal that they belong to the γδ lineage. Tg.Tlaa-3-1 mice should be useful in defining the role of TL in normal and abnormal T cell differentiation as well as in the development of T-cell lymphomas, and further they should facilitate studies on the differentiation and function of γδ T cells. We isolated T3b-TL gene from B6 mice and constructed a chimeric gene in which T3b-TL is driven by the promoter of H-2Kb. With the chimeric gene, two transgenic mouse strains, Tg. Con.3-1 and -2 have been derived in C3H background. Both strains express TL antigen in various tissues including skin. The skin graft of transgenic mice on C3H and (B6 X C3H)F1 mice were rejected. In the mice which rejected the grafts, CD8+TCRαβ cytotoxic T cells (CTL) against TL antigens were recognized. The recognition of TL by CTL did not require the antigen presentation by H-2 molecules. The results indicated that TL antigen in the skin becomes a transplantation antigen and behaves like a typical allogeneic MHC class I antigen. The facts that (B6 X C3H)F1 mice rejected the skin expressing T3b-TL antigen and induced CTL that killed TL+ lymphomas of B6 origin revealed that TL antigen encoded by T3b-TL is recognized as non-self in B6 mice. Experiments are now extended to analyze immune responses to TL antigen expressed on autochthonous T cell lymphomas. (J.P.N.)

  1. Mechanical control over valley magnetotransport in strained graphene

    Science.gov (United States)

    Ma, Ning; Zhang, Shengli; Liu, Daqing

    2016-05-01

    Recent experiments report that the graphene exhibits Landau levels (LLs) that form in the presence of a uniform strain pseudomagnetic field with magnitudes up to hundreds of tesla. We further reveal that the strain removes the valley degeneracy in LLs, and leads to a significant valley polarization with inversion symmetry broken. This accordingly gives rise to the well separated valley Hall plateaus and Shubnikov-de Haas oscillations. These effects are absent in strainless graphene, and can be used to generate and detect valley polarization by mechanical means, forming the basis for the new paradigm "valleytronics" applications.

  2. Human Monoclonal Antibody AVP-21D9 to Protective Antigen Reduces Dissemination of the Bacillus anthracis Ames Strain from the Lungs in a Rabbit Model▿

    Science.gov (United States)

    Peterson, Johnny W.; Comer, Jason E.; Baze, Wallace B.; Noffsinger, David M.; Wenglikowski, Autumn; Walberg, Kristin G.; Hardcastle, Jason; Pawlik, Jennifer; Bush, Kathryn; Taormina, Joanna; Moen, Scott; Thomas, John; Chatuev, Bagram M.; Sower, Laurie; Chopra, Ashok K.; Stanberry, Lawrence R.; Sawada, Ritsuko; Scholz, Wolfgang W.; Sircar, Jagadish

    2007-01-01

    Dutch-belted and New Zealand White rabbits were passively immunized with AVP-21D9, a human monoclonal antibody to protective antigen (PA), at the time of Bacillus anthracis spore challenge using either nasal instillation or aerosol challenge techniques. AVP-21D9 (10 mg/kg) completely protected both rabbit strains against lethal infection with Bacillus anthracis Ames spores, regardless of the inoculation method. Further, all but one of the passively immunized animals (23/24) were completely resistant to rechallenge with spores by either respiratory challenge method at 5 weeks after primary challenge. Analysis of the sera at 5 weeks after primary challenge showed that residual human anti-PA levels decreased by 85 to 95%, but low titers of rabbit-specific anti-PA titers were also measured. Both sources of anti-PA could have contributed to protection from rechallenge. In a subsequent study, bacteriological and histopathology analyses revealed that B. anthracis disseminated to the bloodstream in some naïve animals as early as 24 h postchallenge and increased in frequency with time. AVP-21D9 significantly reduced the dissemination of the bacteria to the bloodstream and to various organs following infection. Examination of tissue sections from infected control animals, stained with hematoxylin-eosin and the Gram stain, showed edema and/or hemorrhage in the lungs and the presence of bacteria in mediastinal lymph nodes, with necrosis and inflammation. Tissue sections from infected rabbits dosed with AVP-21D9 appeared comparable to corresponding tissues from uninfected animals despite lethal challenge with B. anthracis Ames spores. Concomitant treatment with AVP-21D9 at the time of challenge conferred complete protection in the rabbit inhalation anthrax model. Early treatment increased the efficacy progressively and in a dose-dependent manner. Thus, AVP-21D9 could offer an adjunct or alternative clinical treatment regimen against inhalation anthrax. PMID:17452469

  3. Human monoclonal antibody AVP-21D9 to protective antigen reduces dissemination of the Bacillus anthracis Ames strain from the lungs in a rabbit model.

    Science.gov (United States)

    Peterson, Johnny W; Comer, Jason E; Baze, Wallace B; Noffsinger, David M; Wenglikowski, Autumn; Walberg, Kristin G; Hardcastle, Jason; Pawlik, Jennifer; Bush, Kathryn; Taormina, Joanna; Moen, Scott; Thomas, John; Chatuev, Bagram M; Sower, Laurie; Chopra, Ashok K; Stanberry, Lawrence R; Sawada, Ritsuko; Scholz, Wolfgang W; Sircar, Jagadish

    2007-07-01

    Dutch-belted and New Zealand White rabbits were passively immunized with AVP-21D9, a human monoclonal antibody to protective antigen (PA), at the time of Bacillus anthracis spore challenge using either nasal instillation or aerosol challenge techniques. AVP-21D9 (10 mg/kg) completely protected both rabbit strains against lethal infection with Bacillus anthracis Ames spores, regardless of the inoculation method. Further, all but one of the passively immunized animals (23/24) were completely resistant to rechallenge with spores by either respiratory challenge method at 5 weeks after primary challenge. Analysis of the sera at 5 weeks after primary challenge showed that residual human anti-PA levels decreased by 85 to 95%, but low titers of rabbit-specific anti-PA titers were also measured. Both sources of anti-PA could have contributed to protection from rechallenge. In a subsequent study, bacteriological and histopathology analyses revealed that B. anthracis disseminated to the bloodstream in some naïve animals as early as 24 h postchallenge and increased in frequency with time. AVP-21D9 significantly reduced the dissemination of the bacteria to the bloodstream and to various organs following infection. Examination of tissue sections from infected control animals, stained with hematoxylin-eosin and the Gram stain, showed edema and/or hemorrhage in the lungs and the presence of bacteria in mediastinal lymph nodes, with necrosis and inflammation. Tissue sections from infected rabbits dosed with AVP-21D9 appeared comparable to corresponding tissues from uninfected animals despite lethal challenge with B. anthracis Ames spores. Concomitant treatment with AVP-21D9 at the time of challenge conferred complete protection in the rabbit inhalation anthrax model. Early treatment increased the efficacy progressively and in a dose-dependent manner. Thus, AVP-21D9 could offer an adjunct or alternative clinical treatment regimen against inhalation anthrax. PMID:17452469

  4. Biofilm-Exclusion of Uropathogenic Bacteria by Selected Asymptomatic Bacteriuria Escherichia Coli Strains

    DEFF Research Database (Denmark)

    Ferriéres, L.; Hancock, Viktoria; Klemm, Per

    2007-01-01

    Many bacterial infections are associated with biofilm formation. In the urinary tract bacterial biofilms develop on both living surfaces and artificial implants, producing chronic and often intractable infections. Escherichia coli is the most common organism associated with urinary tract infections....... In contrast to uropathogenic E coli (UPEC), which cause symptomatic urinary tract infection, asymptomatic bacteriuria (ABU) strains are associated with essentially symptom-free infections. Here the biofilm-forming capacity on abiotic surfaces of selected E coli ABU strains and UPEC strains in human...... biofilm formation. The results support the notion of bacterial prophylaxis employing selected ABU strains to eliminate UPEC strains and other pathogens in patients prone to recalcitrant infections....

  5. Legionella pneumophila pangenome reveals strain-specific virulence factors

    Directory of Open Access Journals (Sweden)

    Peris-Bondia Francesc

    2010-03-01

    Full Text Available Abstract Background Legionella pneumophila subsp. pneumophila is a gram-negative γ-Proteobacterium and the causative agent of Legionnaires' disease, a form of epidemic pneumonia. It has a water-related life cycle. In industrialized cities L. pneumophila is commonly encountered in refrigeration towers and water pipes. Infection is always via infected aerosols to humans. Although many efforts have been made to eradicate Legionella from buildings, it still contaminates the water systems. The town of Alcoy (Valencian Region, Spain has had recurrent outbreaks since 1999. The strain "Alcoy 2300/99" is a particularly persistent and recurrent strain that was isolated during one of the most significant outbreaks between the years 1999-2000. Results We have sequenced the genome of the particularly persistent L. pneumophila strain Alcoy 2300/99 and have compared it with four previously sequenced strains known as Philadelphia (USA, Lens (France, Paris (France and Corby (England. Pangenome analysis facilitated the identification of strain-specific features, as well as some that are shared by two or more strains. We identified: (1 three islands related to anti-drug resistance systems; (2 a system for transport and secretion of heavy metals; (3 three systems related to DNA transfer; (4 two CRISPR (Clustered Regularly Interspaced Short Palindromic Repeats systems, known to provide resistance against phage infections, one similar in the Lens and Alcoy strains, and another specific to the Paris strain; and (5 seven islands of phage-related proteins, five of which seem to be strain-specific and two shared. Conclusions The dispensable genome disclosed by the pangenomic analysis seems to be a reservoir of new traits that have mainly been acquired by horizontal gene transfer and could confer evolutionary advantages over strains lacking them.

  6. What Are Sprains and Strains?

    Science.gov (United States)

    ... and Strains Find a Clinical Trial Journal Articles Sprains and Strains PDF Version Size: 119 KB Audio Version Time: 07: ... Twist a knee. Where Do Sprains Usually Occur? Sprains happen most often in the ankle. Sometimes when people fall and land on their ...

  7. Pin clad strains in Phenix

    International Nuclear Information System (INIS)

    The Phenix reactor has operated for 4 years in a satisfactory manner. The first 2 sub-assembly loadings contained pins clad in solution treated 316. The principal pin strains are: diametral strain (swelling and irradiation creep), ovality and spiral bending of the pin (interaction of wire and pin cluster and wrapper). A pin cluster irradiated to a dose of 80 dpa F reached a pin diameter strain of 5%. This strain is principally due to swelling (low fission gas pressure). The principal parameters governing the swelling are instantaneous dose, time and temperature for a given type of pin cladding. Other types of steel are or will be irradiated in Phenix. In particular, cold-worked titanium stabilised 316 steel should contribute towards a reduction in the pin clad strains and increase the target burn-up in this reactor. (author)

  8. Psychological strains and youth suicide in rural China.

    Science.gov (United States)

    Zhang, Jie; Wieczorek, William F; Conwell, Yeates; Tu, Xin Ming

    2011-06-01

    The strain theory of suicide postulates that suicide is usually preceded by psychological strains. A strain can be a consequence of any of four conflicts: differential values, aspiration and reality, relative deprivation, and lack of coping skills for a crisis. This study, with a blend of psychiatric and social predictors of suicide, identified correlates of suicide that are relevant to Chinese culture and tested the strain theory of suicide with Chinese data. We sampled 392 suicides and 416 living controls (both aged 15-34 years) from 16 rural counties in China in 2008 and interviewed two informants for each suicide and each control. We found that marriage and religion/religiosity did not distinguish the suicides from the living controls among Chinese rural young women. Religion/religiosity tended to be stronger for suicides than for controls. Psychological strains in the forms of relative deprivation, unrealized aspiration, and lack of coping skills were significantly associated with suicide, even after accounting for the role of mental illness. The strain theory of suicide forms a challenge to the psychiatric model popular in the West, at least in explaining the Chinese suicide. PMID:21640457

  9. Localization of enterobacterial common antigen: Proteus mirabilis and its various L-forms.

    OpenAIRE

    Rinno, J.; Gmeiner, J; Golecki, J R; Mayer, H

    1980-01-01

    An investigation of Proteus mirabilis wild-type strains and their various derived L-forms shows that the enterobacterial common antigen (ECA) is localized in the outer membrane of the cell envelope of these strains. In strains where the outer membrane is lacking (stable protoplast L-forms) or where its amount is reduced (spheroplast UL19) no ECA or only reduced amounts of it are detected by serological tests or by ferritin-labeling techniques.

  10. Prevenção da infecção da corrente sanguínea relacionada ao cateter venoso central: Uma revisão integrativa | Prevention of bloodstream infection related to central venous catheter: An integrative review

    Directory of Open Access Journals (Sweden)

    Alanna Gomes da Silva

    2016-05-01

    Full Text Available Objetivo: Analisar as produções científicas nacionais e internacionais sobre a adoção aos bundles para prevenção de infecção da corrente sanguínea relacionada ao cateter venoso central em unidade de terapia intensiva adulto. Métodos: Foi realizada uma revisão integrativa da literatura nas bases de dados Pubmed, Cinahl e Science Direct, publicados de 2011 a 2014. Resultados: Foram encontrados 11 artigos e em 100% deles as principais medidas adotadas foram antes da inserção do cateter, sendo: antissepsia da pele, uso de barreira máxima de precaução, preferência pela veia subclávia, higienização prévia das mãos e educação e treinamento dos profissionais de saúde. Conclusões: Os bundles estão sendo utilizados na prática clínica como estratégias para redução das infecções, contudo, as infecções da corrente sanguínea relacionadas a cateter continuam a ocorrer de forma alarmante e com grande impacto no cuidado a saúde. Desse modo, estratégias que apontem subsídios para melhoria da prática clínica e segurança do paciente devem ser incentivadas, sobretudo aquelas voltadas para o período crítico da inserção e manutenção do cateter. -----------------------------------------------------------------------------------------------Objective: To analyze the national and international scientific production on the adoption of bundles to prevent bloodstream infection related to central venous catheters in adult intensive care unit. Methods: An integrative literature review of studies published from 2011 to 2014 was conducted in the databases Pubmed, CINAHL and Science Direct. Results: 11 articles were found. In all of them the principal measures adopted before catheter insertion were: skin antisepsis, use of maximum barrier precaution, preference by the subclavian vein, previous hand hygiene, and education and training of health professionals. Conclusions: The bundles are being used in clinical practice as

  11. [L forms of Staphylococcus aureus. Behavior of coagulase, hemolytic and desoxyribonuclease activities and antibiotic sensitivity].

    Science.gov (United States)

    Loschiavo, F; Giarrizzo, S

    1977-01-01

    L Forms derived from strains of coagulase positive Staphylococcus aureus, have, on the whole, preserved their DNAsic, haemolitic and coagulastic activities. L. forms showed high resistence to antibiotics acting on the bacterial cell-wall. The sensibility to other antibiotics was, roughly, analogous for the L forms as well as for the bacterial strains ones, with the exception of the clortetraciclin and the diidrostreptomicin, ehich proved to be comparatively more active on the L forms. PMID:614141

  12. Recent advances in echocardiography: strain and strain rate imaging

    Science.gov (United States)

    Mirea, Oana; Duchenne, Jurgen; Voigt, Jens-Uwe

    2016-01-01

    Deformation imaging by echocardiography is a well-established research tool which has been gaining interest from clinical cardiologists since the introduction of speckle tracking. Post-processing of echo images to analyze deformation has become readily available at the fingertips of the user. New parameters such as global longitudinal strain have been shown to provide added diagnostic value, and ongoing efforts of the imaging societies and industry aimed at harmonizing methods will improve the technique further. This review focuses on recent advances in the field of echocardiographic strain and strain rate imaging, and provides an overview on its current and potential future clinical applications.

  13. Forms of Arthritis

    Science.gov (United States)

    ... this page please turn Javascript on. Forms of Arthritis Past Issues / Fall 2006 Table of Contents Today, ... of Linda Saisselin Osteoarthritis (OA) — the form of arthritis typically occurring during middle or old age, this ...

  14. A novel strain D5 isolated from Acacia confusa.

    Science.gov (United States)

    Huang, Baoling; Lv, Chengqun; Zhao, Yili; Huang, Rong

    2012-01-01

    We isolated a novel strain D5 from nodules of Acacia confusa. Under strict sterile conditions the strain could successfully nodulate Acacia confusa, A. crassicarpa and A. mangium, with nitrogenase activity ranging from 18.90 to 19.86 nmol·g(-1)·min(-1). In the phylogenetic tree based on a complete 16S rRNA gene sequence, the sequence of strain D5 shared 99% homology with that of four species of genus Pseudomonas. The 685 bp nodA fragment amplified from strain D5 shared 95% homology with the nodA sequence of 9 species of genus Bradyrhizobium, with a genetic distance of 0.01682. The 740 bp nifH gene fragment was amplified from strain D5. This strain D5 nifH gene and Bradyrhizobium spp. formed a branch, showing 98% homology and a genetic distance of 0. The homology between this branch and the Bradyrhizobium spp. DG in another branch was 99%, with a genetic distance of 0.007906. These results indicate that this strain D5 is a new type of nitrogen-fixing bacterium. PMID:23166618

  15. Clinical effectiveness and cost-effectiveness of central venous catheters treated with Minocycline and Rifampicin in preventing bloodstream infections in intensive care patients [Medizinische Wirksamkeit und Kosteneffektivität von Minocyclin/Rifampicin-beschichteten zentralvenösen Kathetern zur Prävention von Blutbahninfektionen bei Patienten in intensivmedizinischer Betreuung

    OpenAIRE

    Neusser, Silke; Bitzer, Eva Maria; Mieth, Ingeborg; Krauth, Christian

    2012-01-01

    [english] The use of central venous catheters coated with antibiotics can avoid bloodstream infections with intensive care patients. This is the result of a scientific examination which has been published by the DIMDI. Costs could be also saved in this way. However, according to the authors, the underlying studies do not allow absolutely valid statements.[german] Der Einsatz bestimmter Antibiotika-beschichteter Venenkatheter kann bei Intensivpatienten Blutbahninfektionen vermeiden. So das Erg...

  16. Form postponement: a reconceptualization

    OpenAIRE

    FABRIZIO SALVADOR

    2004-01-01

    Form postponement has been widely acknowledged as one of the main avenues to mitigate the adverse effects of product proliferation or customization on operational performance. As it often happens with long debated concepts, the proposed definitions of form postponement sometimes display substantial differences. This paper aims at moving a step forward towards a more precise definition of form postponement in the domain of tangible products. A first result on this way is that form postponement...

  17. FORMS OF YOUTH TRAVEL

    OpenAIRE

    Moisã Claudia Olimpia

    2011-01-01

    Taking into account the suite of motivation that youth has when practicing tourism, it can be said that the youth travel takes highly diverse forms. These forms are educational tourism, volunteer programs and “work and travel”, cultural exchanges or sports tourism and adventure travel. In this article, we identified and analyzed in detail the main forms of youth travel both internationally and in Romania. We also illustrated for each form of tourism the specific tourism products targeting you...

  18. Deformation twinning: Influence of strain rate

    Energy Technology Data Exchange (ETDEWEB)

    Gray, G.T. III

    1993-11-01

    Twins in most crystal structures, including advanced materials such as intermetallics, form more readily as the temperature of deformation is decreased or the rate of deformation is increased. Both parameters lead to the suppression of thermally-activated dislocation processes which can result in stresses high enough to nucleate and grow deformation twins. Under high-strain rate or shock-loading/impact conditions deformation twinning is observed to be promoted even in high stacking fault energy FCC metals and alloys, composites, and ordered intermetallics which normally do not readily deform via twinning. Under such conditions and in particular under the extreme loading rates typical of shock wave deformation the competition between slip and deformation twinning can be examined in detail. In this paper, examples of deformation twinning in the intermetallics TiAl, Ti-48Al-lV and Ni{sub 3}A as well in the cermet Al-B{sub 4}C as a function of strain rate will be presented. Discussion includes: (1) the microstructural and experimental variables influencing twin formation in these systems and twinning topics related to high-strain-rate loading, (2) the high velocity of twin formation, and (3) the influence of deformation twinning on the constitutive response of advanced materials.

  19. Shewanella strain isolated from black powder

    Energy Technology Data Exchange (ETDEWEB)

    Lutterbach, Marcia T.S.; Contador, Luciana S.; Oliveira, Ana Lucia C.; Galvao, Mariana M. [National Institute of Technology (INT), Rio de Janeiro, RJ (Brazil); Pimenta, Gutemberg S. [PETROBRAS, Rio de Janeiro, RJ (Brazil)

    2009-07-01

    Black powder is a term frequently used to refer to residues formed by various types of iron sulfides mixed with contaminants eventually present in the natural gas flow. According to some researchers, the occurrence of black powder in gas pipelines, besides its chemical corrosion origin, can be directly related to the sulfate-reducing bacteria (SRB) metabolism in this environment. A black powder sample was inoculated in a Post gate E medium modified with the addition of thioglycolate. The resulting positive culture was kept in the laboratory for four years until its use. A dilution technique was then performed aiming to isolate an SRB strain. The bacterial strain isolated and identified through DNA sequencing was not an SRB but rather a Shewanella sp. Compared to the sulfate-reducing bacteria group-traditionally considered the foremost responsible for microbially-influenced corrosion (MIC) - Shewanella is a facultative anaerobe and has a versatile metabolism. Shewanella is able to reduce ferric iron and sulfite, oxidize hydrogen gas, and produce hydrogen sulfide; therefore, these bacteria can be responsible for MIC and pit formation. The isolated Shewanella was used in a corrosion experiment, and the corrosion products were characterized by X-ray diffraction, identifying iron sulfides, iron oxides, and sulfur. Our results indicate that the strain isolated, S. putrefaciens, plays a key role in corrosion problems in gas pipelines. (author)

  20. Structural and functional characterization of two alpha-synuclein strains

    Science.gov (United States)

    Bousset, Luc; Pieri, Laura; Ruiz-Arlandis, Gemma; Gath, Julia; Jensen, Poul Henning; Habenstein, Birgit; Madiona, Karine; Olieric, Vincent; Böckmann, Anja; Meier, Beat H.; Melki, Ronald

    2013-10-01

    α-synuclein aggregation is implicated in a variety of diseases including Parkinson’s disease, dementia with Lewy bodies, pure autonomic failure and multiple system atrophy. The association of protein aggregates made of a single protein with a variety of clinical phenotypes has been explained for prion diseases by the existence of different strains that propagate through the infection pathway. Here we structurally and functionally characterize two polymorphs of α-synuclein. We present evidence that the two forms indeed fulfil the molecular criteria to be identified as two strains of α-synuclein. Specifically, we show that the two strains have different structures, levels of toxicity, and in vitro and in vivo seeding and propagation properties. Such strain differences may account for differences in disease progression in different individuals/cell types and/or types of synucleinopathies.

  1. Phosphate solubilizing ability of two Arctic Aspergillus niger strains

    Directory of Open Access Journals (Sweden)

    Shiv Mohan Singh,

    2011-06-01

    Full Text Available Many filamentous fungi were isolated from the soils of Ny-Ålesund, Spitsbergen, Svalbard, and were screened in vitro for their phosphate solubilizing ability. Two strains of Aspergillus niger showed good tricalcium phosphate (TCP solubilizing ability in Pikovskaya's medium. The TCP solubilization index was calculated at varying levels of pH and temperatures. The ability of Aspergillus niger strain-1 to solubilize and release inorganic-P was 285 µg ml–1, while Aspergillus niger strain-2 solubilized 262 µg ml–1 from 0.5% TCP after seven days. This is the first report of TCP solubilization by Arctic strains that may serve as very good phosphate solubilizers in the form of biofertilizer.

  2. General Friction Model Extended by the Effect of Strain Hardening

    DEFF Research Database (Denmark)

    Nielsen, Chris V.; Martins, Paulo A.F.; Bay, Niels

    2016-01-01

    An extension to the general friction model proposed by Wanheim and Bay [1] to include the effect of strain hardening is proposed. The friction model relates the friction stress to the fraction of real contact area by a friction factor under steady state sliding. The original model for the real......-ideally plastic material, and secondly, to extend the solution by the influence of material strain hardening. This corresponds to adding a new variable and, therefore, a new axis to the general friction model. The resulting model is presented in a combined function suitable for e.g. finite element modeling of...... friction in metal forming, where the material generally strain hardens. The extension of the model to cover strain hardening materials is validated by comparison to previously published experimental data....

  3. Sequencing and characterization of Varicella-Zoster virus vaccine strain SuduVax

    Directory of Open Access Journals (Sweden)

    Kim Jong

    2011-12-01

    Full Text Available Abstract Background Varicella-zoster virus (VZV causes chickenpox in children and shingles in older people. Currently, live attenuated vaccines based on the Oka strain are available worldwide. In Korea, an attenuated VZV vaccine has been developed from a Korean isolate and has been commercially available since 1994. Despite this long history of use, the mechanism for the attenuation of the vaccine strain is still elusive. We attempted to understand the molecular basis of attenuation mechanism by full genome sequencing and comparative genomic analyses of the Korean vaccine strain SuduVax. Results SuduVax was found to contain a genome that was 124,759 bp and possessed 74 open reading frames (ORFs. SuduVax was genetically most close to Oka strains and these Korean-Japanese strains formed a strong clade in phylogenetic trees. SuduVax, similar to the Oka vaccine strains, underwent T- > C substitution at the stop codon of ORF0, resulting in a read-through mutation to code for an extended form of ORF0 protein. SuduVax also shared certain deletion and insertion mutations in ORFs 17, 29, 56 and 60 with Oka vaccine strains and some clinical strains. Conclusions The Korean VZV vaccine strain SuduVax is genetically similar to the Oka vaccine strains. Further comparative genomic and bioinformatics analyses will help to elucidate the molecular basis of the attenuation of the VZV vaccine strains.

  4. Screening Three Strains of Pseudomonas aeruginosa: Prediction of Biosurfactant-Producer Strain

    Directory of Open Access Journals (Sweden)

    Gholamreza Dehghan-Noudeh

    2009-01-01

    Full Text Available Problem statement: The chemical surfactants have some disadvantages; especially, toxicity and no biodegradability. Approach: Biosurfactants were the structurally diverse group of surface-active molecules synthesize by micro-organisms. The microbial surfactants were interesting, because of the biodegradable and have many applications in industry, agriculture, medicine. Results: In the present study, the production of biosurfactant by three strains of Pseudomonas aeruginosa (PTCC 1074, 1310 and 1430 was investigated. The hemolytic and foam forming activity of different strains were studied and consequently, P. aeruginosa PTCC 1074 was selected as the suitable strain. P. aeruginosa PTCC 1074 was grown in the nutrient broth medium and biosurfactant production was evaluated every 24 h by emulsification index and surface tension for the best of production time. After that, in order to get maximum production of biosurfactant, the selected strain was grown with different additives in nutrient broth and the best culture medium was found. The biosurfactant was isolated from the supernatant and its amphipathic structure was confirmed by chemical methods. Conclusion: Biosurfactant produced by Pseudomonas aeruginosa PTCC 1074 would be considered as a suitable surfactant in industries due to its low toxicity.

  5. Forming limit and fracture mechanism of ferritic stainless steel sheets

    International Nuclear Information System (INIS)

    Research highlights: → Forming limit curves of two ferritic stainless steel sheets were well predicted. → Failure occurs by necking in uniaxial and plane strain tension for both materials. → Failure occurs by shearing in balanced biaxial tension for both materials. → Strain rate sensitivity does not affect the limit strains a lot for both materials. → Strain rate sensitivity likely influences the failure mode for both materials. - Abstract: In this work, the forming limit curves (FLCs) of two ferritic stainless steel sheets, AISI409L and AISI430, were predicted with the Marciniak-Kuczynski (MK) and Bressan-William-Hill (BWH) models, combined with the Yld2000-2d yield function and the Swift hardening law. Uniaxial tension, disk compression and hydraulic bulge tests were performed to determine the yield loci and hardening curves of both materials. Meanwhile, the strain rate sensitivity (SRS) coefficient was measured through uniaxial tension tests carried out at different strain rates. Out-of-plane stretching tests were conducted in sheet specimens to obtain the surface limit strains under different linear strain paths. Micrographs of the specimens fractured in different stress states were obtained by optical and scanning electron microscopy. The overall results show that the BWH model can predict the FLC better than the MK model, and that the SRS does not have much effect on the limit strains for both materials. The predicted FLCs and micrograph analysis both indicate that failure occurs by surface localized necking in uniaxial and plane strain tension states, whereas it occurs by localized shearing in the through thickness direction in balanced biaxial tension state.

  6. Laser based micro forming and assembly.

    Energy Technology Data Exchange (ETDEWEB)

    MacCallum, Danny O' Neill; Wong, Chung-Nin Channy; Knorovsky, Gerald Albert; Steyskal, Michele D.; Lehecka, Tom (Pennsylvania State University, Freeport, PA); Scherzinger, William Mark; Palmer, Jeremy Andrew

    2006-11-01

    It has been shown that thermal energy imparted to a metallic substrate by laser heating induces a transient temperature gradient through the thickness of the sample. In favorable conditions of laser fluence and absorptivity, the resulting inhomogeneous thermal strain leads to a measurable permanent deflection. This project established parameters for laser micro forming of thin materials that are relevant to MESA generation weapon system components and confirmed methods for producing micrometer displacements with repeatable bend direction and magnitude. Precise micro forming vectors were realized through computational finite element analysis (FEA) of laser-induced transient heating that indicated the optimal combination of laser heat input relative to the material being heated and its thermal mass. Precise laser micro forming was demonstrated in two practical manufacturing operations of importance to the DOE complex: micrometer gap adjustments of precious metal alloy contacts and forming of meso scale cones.

  7. Magnetostriction strain measurement: heterodyne laser interferometry versus strain gauge technique

    OpenAIRE

    Gorji Ghalamestani, Setareh; Vandevelde, Lieven; J.J. Dirckx, Joris; Melkebeek, Jan

    2013-01-01

    Deformation of the ferromagnetic material, known as magnetostriction, causes vibrations and noise of electrical machines and transformer cores. A setup by using heterodyne laser interferometers has been built to measure the magnetostriction strains as a function of the applied magnetic field. The measurement results on a sample of nonoriented electrical steel are presented in this work. These results are compared with those obtained by using a strain gauge setup. The laser measurements are l...

  8. Mercury retention in several strains and strain crosses of chickens

    Energy Technology Data Exchange (ETDEWEB)

    Miller, V.L.; Bearse, G.E.; Csonka, E.

    1970-01-01

    The retention of mercury from injections of mercuric chloride was determined in 32 samples of chicks from various strains and strain crosses of egg type stock. The chicks retaining the most mercury had some four times as much mercury in the liver and kidneys as the chicks retaining the lowest amount. The chicks selected for resistance to leukosis retained more mercury than the susceptible chicks within several leukosis breeding programs.

  9. Role of Streptococcus sanguis (strain Wicky) cell surface-located deoxyribonucleic acid-binding factor in transformation of a homologous strain.

    OpenAIRE

    Cegłowski, P; Kawczyński, M; Dobrzański, W T

    1981-01-01

    In a previous report we demonstrated the presence of a factor binding deoxyribonucleic acid (DNA) in vitro (BF) in cell leakage fluids from transformable Streptococcus sanguis strains Wicky, Challis, and Blackburn. BF originating from strain Wicky was purified to homogeneity, and its properties are described. In this work, it was found that BF occurs at the surface of Wicky cells in two forms, loosely bound (LB-BF) and strongly bound to the cell envelope. It was demonstrated that LB-BF formed...

  10. [Multilocus sequence-typing for characterization of Moscow strains of Haemophilus influenzae type b].

    Science.gov (United States)

    Platonov, A E; Mironov, K O; Iatsyshina, S B; Koroleva, I S; Platonova, O V; Gushchin, A E; Shipulin, G A

    2003-01-01

    Haemophilius influenzae, type b (Hib) bacteria, were genotyped by multilocus sequence typing (MLST) using 5 loci (adk, fucK, mdh, pgi, recA). 42 Moscow Hib strains (including 38 isolates form cerebrospinal fluid of children, who had purulent meningitis in 1999-2001, and 4 strains isolated from healthy carriers of Hib), as well as 2 strains from Yekaterinburg were studied. In MLST a strain is characterized, by alleles and their combinations (an allele profile) referred to also as sequence-type (ST). 9 Sts were identified within the Russian Hib bacteria: ST-1 was found in 25 strains (57%), ST-12 was found in 8 strains (18%), ST-11 was found in 4 strains (9%) and ST-15 was found in 2 strains (4.5%); all other STs strains (13, 14, 16, 17, 51) were found in isolated cases (2.3%). A comparison of allelic profiles and of nucleotide sequences showed that 93% of Russian isolates, i.e. strain with ST-1, 11, 12, 13, 15 and 17, belong to one and the same clonal complex. 2 isolates from Norway and Sweden from among 7 foreign Hib strains studied up to now can be described as belonging to the same clonal complex; 5 Hib strains were different from the Russian ones. PMID:12800772

  11. Development of unconventional forming methods

    Directory of Open Access Journals (Sweden)

    S. Rusz

    2012-10-01

    Full Text Available Purpose: Paper presents results of progress ECAP processing method for UFG structure reached (gained.The properties and microstructure are influenced by technological factors during application ECAP method.Design/methodology/approach: Summary of methods studied on Department of technology at Machining faculty of VŠB-TU Ostrava through of co-operation with Institute of Engineering Materials and Biomaterials, Silesian University of Technology is presented.Findings: Achievement of ultra-fine grained structure in initial material leads to substantial increase of plasticity and makes it possible to form materials in conditions of „superplastic state“. Achievement of the required structure depends namely of the tool geometry, number of passes through the matrix, obtained deformation magnitude and strain rate, process temperature and lubrication conditions. High deformation at comparatively low homologous temperatures is an efficient method of production of ultra-fine grained solid materials.The new technologies, which use severe plastic deformation, comprise namely these techniques: High Pressure Torsion, Equal Channel Angular Pressing = ECAP, Cyclic Channel Die Compression = CCDC, Cyclic Extrusion Compression = CEC, Continuous Extrusion Forming = CONFORM, Accumulative Roll Bonding, Constrained Groove Pressing.Research limitations/implications: Achieved hardness and microstructure characteristics will be determined by new research.Practical implications: The results may be utilized for a relation between structure and properties of the investigated materials in future process of manufacturing.Originality/value: These results contribute to complex evaluation of properties new metals after application unconventional forming methods. The results of this paper are determined for research workers deal by the process severe plastic deformation.

  12. Numerical simulation and experimental investigation of incremental sheet forming process

    Institute of Scientific and Technical Information of China (English)

    HAN Fei; MO Jian-hua

    2008-01-01

    In order to investigate the process of incremental sheet forming (ISF) through both experimental and numerical approaches, a three-dimensional elasto-plastic finite element model (FEM) was developed to simulate the process and the simulated results were compared with those of experiment. The results of numerical simulations, such as the strain history and distribution, the stress state and distribution, sheet thickness distribution, etc, were discussed in details, and the influences of process parameters on these results were also analyzed. The simulated results of the radial strain and the thickness distribution are in good agreement with experimental results. The simulations reveal that the deformation is localized around the tool and constantly remains close to a plane strain state. With decreasing depth step, increasing tool diameter and wall inclination angle, the axial stress reduces, leading to less thinning and more homogeneous plastic strain and thickness distribution. During ISF, the plastic strain increases stepwise under the action of the tool. Each increase in plastic strain is accompanied by hydrostatic pressure, which explains why obtainable deformation using ISF exceeds the forming limits of conventional sheet forming.

  13. Roll bonding of strained aluminium

    DEFF Research Database (Denmark)

    Staun, Jakob M.

    2003-01-01

    This report investigates roll bonding of pre-strained (å ~ 4) aluminium sheets to produce high strain material from high purity aluminium (99.996%) and commercial pure aluminium (99.6%). The degree of bonding is investigated by optical microscopy and ultrasonic scanning. Under the right...... circumstances both materials show good bonding, but the high purity material is excluded because of recrystallisation and the resulting loss of mechanical properties. The effect of cross stacking and roll bonding pre-strained sheets of the commercial purity material is investigated and some dependence of the...... cross rolled volume fraction is found. To further asses this effect, and the anisotropy, it is necessary to acquire knowledge about both texture and microstructure, e.g. by TEM. Roll bonding of pre-strained aluminium is found to be a possible alternative to ARB in the quest for ultra-fine grained...

  14. Tunable biaxial in-plane compressive strain in a Si nanomembrane transferred on a polyimide film

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Munho; Mi, Hongyi; Cho, Minkyu; Seo, Jung-Hun; Ma, Zhenqiang, E-mail: mazq@engr.wisc.edu [Department of Electrical and Computer Engineering, University of Wisconsin–Madison, Madison, Wisconsin 53706 (United States); Zhou, Weidong [Department of Electrical Engineering, University of Texas at Arlington, Arlington, Texas 76019 (United States); Gong, Shaoqin [Department of Biomedical Engineering and Wisconsin Institute for Discovery, University of Wisconsin–Madison, Madison, Wisconsin 53706 (United States)

    2015-05-25

    A method of creating tunable and programmable biaxial compressive strain in silicon nanomembranes (Si NMs) transferred onto a Kapton{sup ®} HN polyimide film has been demonstrated. The programmable biaxial compressive strain (up to 0.54%) was generated utilizing a unique thermal property exhibited by the Kapton HN film, namely, it shrinks from its original size when exposed to elevated temperatures. The correlation between the strain and the annealing temperature was carefully investigated using Raman spectroscopy and high resolution X-ray diffraction. It was found that various amounts of compressive strains can be obtained by controlling the thermal annealing temperatures. In addition, a numerical model was used to evaluate the strain distribution in the Si NM. This technique provides a viable approach to forming in-plane compressive strain in NMs and offers a practical platform for further studies in strain engineering.

  15. Micro metal forming

    CERN Document Server

    2013-01-01

    Micro Metal Forming, i. e. forming of parts and features with dimensions below 1 mm, is a young area of research in the wide field of metal forming technologies, expanding the limits for applying metal forming towards micro technology. The essential challenges arise from the reduced geometrical size and the increased lot size. In order to enable potential users to apply micro metal forming in production, information about the following topics are given: tribological behavior: friction between tool and work piece as well as tool wear mechanical behavior: strength and formability of the work piece material, durability of the work pieces size effects: basic description of effects occurring due to the fact, that the quantitative relation between different features changes with decreasing size process windows and limits for forming processes tool making methods numerical modeling of processes and process chains quality assurance and metrology All topics are discussed with respect to the questions relevant to micro...

  16. Hypervirulent strains of Clostridium difficile

    OpenAIRE

    Cookson, Barry

    2007-01-01

    North America has seen increasing numbers of hospitalised patients and others in nursing homes and the community, with more severe Clostridium difficile associated diarrhoea. This is also described in Northern Europe and surveillance systems are being developed or improved to monitor the situation. One strain (ribotype O27) is described in detail and, like other emerging strains, is demonstrating increasing antimicrobial resistance, notably to quinolone antibiotics. However, its association w...

  17. Biocontrol mechanisms of Thrichoderma strains

    OpenAIRE

    Benítez Fernández, Concepción Tahía; Rincón Romero, Ana María; Limón Mirón, María del Carmen; Carballo Codón, Antonio

    2004-01-01

    The genus Trichoderma comprises a great number of fungal strains that act as biological control agents, the antagonistic properties of which are based on the activation of multiple mechanisms. Trichoderma strains exert biocontrol against fungal phytopathogens either indirectly, by competing for nutrients and space, modifying the environmental conditions, or promoting plant growth and plant defensive mechanisms and antibiosis, or directly, by mechanisms such as mycoparasitism. These indirect a...

  18. Apparatus for pre-stress-straining rod-type specimens in tension for in-situ passive fracture testing

    Science.gov (United States)

    Wang, John Jy-an; Liu, Ken C.; Feng, Zhili

    2013-07-31

    A stress-strain testing apparatus imposes a stress-strain on a specimen while disposed in a controlled environment. Each end of the specimen is fastened to an end cap and a strain gage is attached to the specimen. An adjusting mechanism and a compression element are disposed between the end caps forming a frame for applying forces to the end caps and thereby stress-straining the specimen. The adjusting mechanism may be extended or retracted to increase or decrease the imposed stress-strain on the specimen, and the stress-strain is measured by the strain gage on the specimen while the apparatus is exposed to an environment such as high pressure hydrogen. Strain gages may be placed on the frame to measure stress-strains in the frame that may be caused by the environment.

  19. Thermoresistive Strain Sensor and Positioning Method for Roll-to-Roll Processes

    OpenAIRE

    Kuan-Hsun Liao; Cheng-Yao Lo

    2014-01-01

    This study uses the Joule heating effect-generated temperature difference to monitor in real-time and localize both compressive and tensile strains for the polymer substrates used in the roll-to-roll process. A serpentine gold (Au) line was patterned on a polyethylenenaphthalate (PEN) substrate to form the strain sensor based on thermoresistive behavior. This strain sensor was then subjected to either current or voltage to induce the Joule heating effect on the Au resistor. An infrared (IR) d...

  20. Continuous degradation of trichloroethylene by Xanthobacter sp. strain Py2 during growth on propene.

    OpenAIRE

    Reij, M.W.; Kieboom, J.; de Bont, J A; Hartmans, S

    1995-01-01

    Propene-grown Xanthobacter sp. strain Py2 cells can degrade trichloroethylene (TCE), but the transformation capacity of such cells was limited and depended on both the TCE concentration and the biomass concentration. Toxic metabolites presumably accumulated extracellularly, because the fermentation of glucose by yeast cells was inhibited by TCE degradation products formed by strain Py2. The affinity of the propene monooxygenase for TCE was low, and this allowed strain Py2 to grow on propene i...

  1. Pulsed Power Forming

    OpenAIRE

    Gafri, O.; Izhar, A.; Livshitz, Y.; Shribman, V.

    2004-01-01

    R&D and application work in the sphere of Pulsed Power Forming (PPF) is well known and has been documented since the 1960's, along with its advantages. Pulsed Power Forming applications, which have been developed at Pulsar Ltd over the last decade, are described in this paper. Special equipment and tools for forming have been designed, developed, and manufactured, utilising pulsed magnetic fields. Theoretical and experimental research has been carried out to determine the magnetic field distr...

  2. FLOW FORMING OF AEROENGINEMATERIALS

    OpenAIRE

    Kubilay, Ceylan

    2014-01-01

    Flow forming is a fairly new technique used for the production of dimensionallyaccurate near net shaped hollow components. The process has many advantagessuch as cost effectiveness and eliminating further operations like welding, machin-ing, etc. This study focuses on the characterization of flow formed componentsto understand the process. Flow formed components are composed of differentreductions and characterization techniques are applied to reveal the resulting mi-crostructural differences...

  3. Fractional Differential Forms

    OpenAIRE

    Cotrill-Shepherd, Kathleen; NAber, Mark

    2003-01-01

    A generalization of exterior calculus is considered by allowing the partial derivatives in the exterior derivative to assume fractional orders. That is, a fractional exterior derivative is defined. This is found to generate new vector spaces of finite and infinite dimension, fractional differential form spaces. The definitions of closed and exact forms are extended to the new fractional form spaces with closure and integrability conditions worked out for a special case. Coordinate transformat...

  4. Regarding proton form factors

    OpenAIRE

    Bloch, J. C. R.; Krassnigg, A.; Roberts, C. D.

    2003-01-01

    The proton's elastic electromagnetic form factors are calculated using an Ansatz for the nucleon's Poincare' covariant Faddeev amplitude that only retains scalar diquark correlations. A spectator approximation is employed for the current. On the domain of q^2 accessible in modern precision experiments these form factors are a sensitive probe of nonperturbative strong interaction dynamics. The ratio of Pauli and Dirac form factors can provide realistic constraints on models of the nucleon and ...

  5. Strain evaluation in fatigue analysis

    International Nuclear Information System (INIS)

    Thermoplastic analysis and more precisely fatigue analysis of nuclear components working at high temperature is usually very difficult and very expensive. Simplified methods have been proposed and are generally used to perform analysis of these structures. These simplified methods require elastic analysis of the component. For a fatigue analysis it is necessary to obtain a very precise value of the strains so the elastic strains must be corrected in order to take plasticity into account. This later appears in two different ways. Non linearity of material which induces strain amplification when working in the plastic field especially near by geometric discontinuities. That can be taken into account with a coefficient Ke. Triaxiality and isovolumic character of strains in the plastic field. That also induces strain amplification with regard to elastic computation. It is proposed in this work to introduce a coefficient Kv to estimate this strain amplification. Several elastic and plastic calculations for typical geometries, have been done in order to test the importance of these parameters and to set up methods for evaluating the coefficients Ke and Kv

  6. Cooperative Station History Forms

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Various forms, photographs and correspondence documenting the history of Cooperative station instrumentation, location changes, inspections, and...

  7. Finite-element study of strain field in strained-Si MOSFET.

    Science.gov (United States)

    Liu, H H; Duan, X F; Xu, Q X

    2009-02-01

    The strain field in the channel of a p-type metal-oxide-semiconductor field effect transistor fabricated by integrating Ge pre-amorphization implantation for source/drain regions is evaluated using a finite-element method combining with large angle convergent-beam electron diffraction (LACBED). The finite-element calculation shows that there is a very large compressive strain in the top layer of the channel region caused by a low dose of Ge ion implantation in the source and drain extension regions. Moreover, a transition region is formed in the bottom of the channel region and the top of the Si substrate. These calculation results are in good agreement with the LACBED experiments. PMID:18996702

  8. 血流感染脓毒症患者炎症因子水平与疾病严重程度相关性研究%Correlation between levels of inflammatory cytokines in sepsis patients with bloodstream infections and severity of disease

    Institute of Scientific and Technical Information of China (English)

    赵磊; 盛博; 李丽娟; 陈炜

    2015-01-01

    OBJECTIVE To explore the correlation between the levels of inflammatory cytokines in the sepsis pa‐tients with bloodstream infections such as procalcitonin (PCT) ,C‐reactive protein (CRP) ,and endotoxin and the severity of disease so as to provide guidance for diagnosis of disease .METHODS A total of 134 sepsis patients who were positive for blood culture were retrospectively analyzed .The levels of the inflammatory cytokines within 24 hours were compared between the patients with bloodstream infections caused by gram‐negative bacteria and the patients with bloodstream infections caused by gram‐positive bacteria ,and the correlations with APACHE Ⅱscores were observed .RESULTS The levels of CRP ,PCT ,and endotoxin in all the patients with bloodstream in‐fections and the subgroup patients were significantly correlated with the APACHE Ⅱ score ,the correlation with PCT was the highest in the patients with bloodstream infections caused by the gram‐negative bacteria ,and the cor‐relation with CRP was the highest in the patients with bloodstream infections caused by the gram‐positive bacteria . The levels of PCT and CRP of the subgroup patients with severe sepsis or septic shock were significantly higher than those of the subgroup patients with sepsis (P<0 .01) .However ,the levels of PCT ,CRP ,and endotoxin of the subgroup patients with severe sepsis or septic shock in the gram‐negative bacteria group were significantly higher than those of the subgroup patients with severe sepsis or septic shock in the gram‐positive bacteria . CONCLUSION The levels of the blood inflammatory cytokines in the sepsis patients with bloodstream infections caused by both the gram‐negative bacteria and the gram‐positive bacteria are positively correlated with the severity of disease .%目的:探讨降钙素原(PCT )、C‐反应蛋白(CRP)、内毒素等炎症因子在细菌性血流感染脓毒症患者中的水平及与疾病严重程度的相关性,

  9. Finite Element Prediction of Sheet Forming Defects Using Elastic-Plastic, Damage and Localization Models

    Science.gov (United States)

    Haddag, Badis; Abed-Meraim, Farid; Balan, Tudor

    2007-05-01

    In this work, an advanced anisotropic elastic-plasticity model is combined with a damage model and a strain localization criterion in the aim to describe accurately the mechanical behavior of sheet metals. Large strain, fully three-dimensional, implicit time integration algorithms are developed for this model and implemented in the finite element code Abaqus. The resulting code is used to predict the strain localization limits as well as the springback after forming of sheet steels. The impact of strain-path dependent hardening models on the limit strains and on the amount of springback is addressed.

  10. Form and Human Body

    OpenAIRE

    Wan, Mingchao

    2014-01-01

    Architectural form offers an expression and an observer receives an impression. This interaction exists at both intellectual (mind) and physical (body) levels. Through designing a sculpture pavilion in a forest, this thesis explores different means of empathetic expression in modern architectural form.

  11. Mastering HTML5 forms

    CERN Document Server

    Gupta, Gaurav

    2013-01-01

    This tutorial will show you how to create stylish forms, not only visually appealing, but interactive and customized, in order to gather valuable user inputs and information.Enhance your skills in building responsive and dynamic web forms using HTML5, CSS3, and related technologies. All you need is a basic understanding of HTML and PHP.

  12. Forms of Customs Control

    OpenAIRE

    Шевчук, Олег Анатолійович

    2015-01-01

    The research on the forms of customs control was conducted. There was analysed the specific of control activity of customs authorities in the field of financial relations, conditions and forms of its realization. The introduction into practice of customs control system analysis and risk management, customs inspection, the method of "customs audit" is suggested.

  13. Forming of Laminates

    NARCIS (Netherlands)

    De Jong, T.W.

    2004-01-01

    Fibre-Metal-Laminates have excellent properties for aerospace applications, with GLARE as an example. The metal layers inside the laminate provide permanent plastic deformations for the whole laminate; in principle Fibre-Metal-Laminates can be formed with common sheet metal forming processes. The d

  14. Probiotic Escherichia coli strain Nissle 1917 outcompetes intestinal pathogens during biofilm formation

    DEFF Research Database (Denmark)

    Hancock, Viktoria; Dahl, M.; Klemm, Per

    2010-01-01

    Nissle 1917 has been used for many decades as a probiotic against a variety of intestinal disorders and is probably the best field-tested E. coil strain in the world. Here we have investigated the biofilm-forming capacity of Nissle 1917. We found that the strain was a good biofilm former. Not only was it...

  15. Danish Rhizobium leguminosarum strains nodulating ‘Afghanistan’ pea (Pisum sativum)

    DEFF Research Database (Denmark)

    Jensen, Erik Steen; Sørensen, Lasse Holst; Engvild, Kjeld Christensen

    1986-01-01

    A wild pea (Pisum sativum L.) native to Afghanistan normally known to be resisant to nodulation with European strains of Rhizobium leguminosarum was nodulated early and effectively in field soil in Denmark. Isolates from nodules formed effective nodules abundantly on 'Afghanistan' on reinfection...... pattern with Rhizobium leguminosarum strains isolated from a modern pea variety cultivated in the same field....

  16. The origins of strain stiffening in fibrin networks

    Science.gov (United States)

    Jawerth, Louise; Muenster, Stefan; Weitz, David

    2012-02-01

    Fibrin networks form the structural scaffold of blood clots; their non-linear mechanical properties are crucial to stem the flow of blood at a site of vascular injury. A hallmark of these networks is strain stiffening: a stiffness that increases non-linearly as a network is strained. Deformations of the fibers and the network combine to control the mechanical properties of the bulk and must lead to the strain stiffening behavior of the networks; however, the details of this process are unknown. Here, we study fibrin networks undergoing shear on a confocal microscope and compare this to bulk rheological measurements. We track individual fiber branchpoints as function of system strain. We characterize the non-affinity of the motion and show that the low strain, linear regime corresponds to highly non-affine motion while the high strain, nonlinear regime corresponds to affine motion. Moreover, we show that the non-linear bulk response can be well approximated by considering the fibers to be linear elastic elements with soft compressive behavior and, therefore, is a result of the topology of the network itself rather than nonlinearity of its constituents.

  17. Isolation and characterization of organic-sulfur degradation bacterial strain

    Institute of Scientific and Technical Information of China (English)

    YANG Yu; DIAO Meng-xue; SHI Wu-yang; LI Li; DAI Qin-yun; QIU Guan-zhou

    2007-01-01

    A bacterial strain that was capable of degrading organic sulfur (dibenzothiophene) was isolated by enrichment techniques from the petroleum-contaminated soil collected from Zhongyuan Oil Field. The strain is named ZYX and is gram-positive.This strain undergoes bacilus-coccus morphological change, and forms yellow-pigment glossy circular colonies with 1.5 mm in diameter on average after 2 d incubation on Luria-Bertani(LB) plates. The full-length of 16S rDNA sequence of strain ZYX was determined and analyzed. Strain ZYX is found most relative with the genus of Arthrobacter. The similarity values between ZYX and Arthrobacter sp. P2 is 99.53%. The main morphological, biochemical and physiological features of strain ZYX accord with those of Arthrobacter. It is found that the optimal initial pH for growth is about 7.0, and the optimal concentration of dibenzothiophene(DBT)for growth is 0.10 g/L. Additionally, the results show that the best carbon source and nitrogen source are glycerol and glutamine,respectively.

  18. The Characterization of Protein Profiles of the Aeromonas hydrophila and A. caviae Strains Isolated from Gull and Rainbow Trout Feces by SDS-PAGE

    OpenAIRE

    KÖRKOCA, Hanifi; BOYNUKARA, Banur

    2003-01-01

    Ten motile Aeromonads, including one Aeromonas hydrophila ATCC 7512, were used. Of the strains, five were isolated from gulls (one A. hydrophila strain and four A. caviae strains) and four from rainbow trout (three A. hydrophila strains and one A. caviae strain). Whole cell protein profiles of these strains were analyzed by SDS-PAGE. Forty-five pairs were formed in comparing the protein profiles of each strain. Of the pairs, 17 (37.8%) were different, 18 (40%) were unclear and 10 (22.2%) were...

  19. Characterisation of human diaphragm at high strain rate loading.

    Science.gov (United States)

    Gaur, Piyush; Chawla, Anoop; Verma, Khyati; Mukherjee, Sudipto; Lalvani, Sanjeev; Malhotra, Rajesh; Mayer, Christian

    2016-07-01

    Motor vehicle crashes (MVC׳s) commonly results in life threating thoracic and abdominal injuries. Finite element models are becoming an important tool in analyzing automotive related injuries to soft tissues. Establishment of accurate material models including tissue tolerance limits is critical for accurate injury evaluation. The diaphragm is the most important skeletal muscle for respiration having a bi-domed structure, separating the thoracic cavity from abdominal cavity. Traumatic rupture of the diaphragm is a potentially serious injury which presents in different forms depending upon the mechanisms of the causative trauma. A major step to gain insight into the mechanism of traumatic rupture of diaphragm is to understand the high rate failure properties of diaphragm tissue. Thus, the main objective of this study was to estimate the mechanical and failure properties of human diaphragm at strain rates associated with blunt thoracic and abdominal trauma. A total of 23 uniaxial tensile tests were performed at various strain rates ranging from 0.001-200s(-1) in order to characterize the mechanical and failure properties on human diaphragm tissue. Each specimen was tested to failure at one of the four strain rates (0.001s(-1), 65s(-1), and 130s(-1), 190s(-1)) to investigate the effects of strain rate dependency. High speed video and markers placed on the grippers were used to measure the gripper to gripper displacement. Engineering stresses reported in the study is calculated from the ratio of force measured and initial cross sectional area whereas engineering strain is calculated from the ratio of the elongation to the undeformed length (gauge length) of the specimen.The results of this study showed that the diaphragm tissues is rate dependent with higher strain rate tests giving higher failure stress and higher failure strains. The failure stress for all tests ranged from 1.17MPa to 4.1MPa and failure strain ranged from 12.15% to 24.62%. PMID:27062242

  20. Wireless Zigbee strain gage sensor system for structural health monitoring

    Science.gov (United States)

    Ide, Hiroshi; Abdi, Frank; Miraj, Rashid; Dang, Chau; Takahashi, Tatsuya; Sauer, Bruce

    2009-05-01

    A compact cell phone size radio frequency (ZigBee) wireless strain measurement sensor system to measure the structural strain deformation was developed. The developed system provides an accurate strain measurement data stream to the Internet for further Diagnostic and Prognostic (DPS) correlation. Existing methods of structural measurement by strain sensors (gauges) do not completely satisfy problems posed by continuous structural health monitoring. The need for efficient health monitoring methods with real-time requirements to bidirectional data flow from sensors and to a commanding device is becoming critical for keeping our daily life safety. The use of full-field strain measurement techniques could reduce costly experimental programs through better understanding of material behavior. Wireless sensor-network technology is a monitoring method that is estimated to grow rapidly providing potential for cost savings over traditional wired sensors. The many of currently available wireless monitoring methods have: the proactive and constant data rate character of the data streams rather than traditional reactive, event-driven data delivery; mostly static node placement on structures with limited number of nodes. Alpha STAR Electronics' wireless sensor network system, ASWN, addresses some of these deficiencies, making the system easier to operate. The ASWN strain measurement system utilizes off-the-shelf sensors, namely strain gauges, with an analog-to-digital converter/amplifier and ZigBee radio chips to keep cost lower. Strain data is captured by the sensor, converted to digital form and delivered to the ZigBee radio chip, which in turn broadcasts the information using wireless protocols to a Personal Data Assistant (PDA) or Laptop/Desktop computers. From here, data is forwarded to remote computers for higher-level analysis and feedback using traditional cellular and satellite communication or the Ethernet infrastructure. This system offers a compact size, lower cost

  1. iFORM

    OpenAIRE

    Dall, Karoline; Nilsson, Katrine

    2014-01-01

    This project is a critical discourse analyses on the Danish health magazine iFORM. We see that there are certain ways to talk about health in the society, and if iFORM observe this and in which ways. Furthermore we want study the themes iFORM is focusing on and how these themes are articulated in selected excerpts. In addition to this we have chosen to make a target group interview with a small group of iFORM’s readers. We want to study the participants’ individual understandings about hea...

  2. PowerForms

    DEFF Research Database (Denmark)

    Brabrand, Claus; Møller, Anders; Ricky, Mikkel;

    2000-01-01

    such validation. Today, CGI programmers often use Perl libraries for simple server-side validation or program customized JavaScript solutions for client-side validation. We present PowerForms, which is an add-on to HTML forms that allows a purely declarative specification of input formats and...... user. For other GUI components the available options are dynamically filtered to present only the allowed values. PowerForms are integrated into the system for generating interactive Web services, but is also freely available in an Open Source distribution as a stand-alone package....

  3. Unified form language

    DEFF Research Database (Denmark)

    Alnæs, Martin S.; Logg, Anders; Ølgaard, Kristian Breum;

    2014-01-01

    We present the Unied Form Language (UFL), which is a domain-specic language for representing weak formulations of partial dierential equations with a view to numerical approximation. Features of UFL include support for variational forms and functionals, automatic dierentiation of forms and...... compact, intuitive and readable programs. We present in this work the language and its construction. An implementation of UFL is freely available as an open-source software library. The library generates abstract syntax tree representations of variational problems, which are used by other software...

  4. A Study on Forming Characteristics of Roll Forming Process with High Strength Steel

    Science.gov (United States)

    Joo, ByeongDon; Lee, HyunJong; Kim, DongKyu; Moon, YoungHoon

    2011-08-01

    Roll forming is a kind of sheet metal forming process used to manufacture long sheet metal products with constant cross section. Recently, roll forming technology draws attentions of automotive industries due to its various advantages, such as high production speed, reduced tooling cost and improved quality. In automotive industries, roll formed automotive parts used as structural components in vehicle body frame or sub frame and high strength steel becomes more common to improve safety and fuel efficiency. However, when roll forming process is performed with high strength steel, rolling forming defects, such as spring back, buckling and scratch should be considered more carefully. In this study, efforts to avoid roll forming defects and to optimize forming parameters were performed. FE analysis was performed with high strength steels using commercially available simulation software, COPRA-RF™ and SHAPE-RF™. Forming characteristics were analyzed and roll flower model and proper roll-pass sequences were suggested by analyzing longitudinal strain and deformation behavior. This study provided considerable experience about roll forming process design that using high strength steel.

  5. Investigation on activation and strain-rate sensitivity in ultrafine-grained tantalum

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Y.; Liu, Y.; Wang, J.T., E-mail: jtwang@njust.edu.cn

    2015-05-21

    The activation volume and strain-rate sensitivity (SRS) of a plastic deformation process and their relationship are investigated in the present work. Through theoretical modeling based on the movement of both isolated kinks and kink pairs in a dislocation line, a new form of theoretical relationship between the strain-rate sensitivity and activation volume was developed, which reduces to the conventional and frequently used form of the same relationship when SRS is approaching zero. The strain rate jump test during the necking stage of tensile testing process is validated through combined theoretical analytical approaches, for obtaining strain rate sensitivity of materials with short uniform tensile stage, such as UFG metals. To validate the theoretical approaches and modeling presented in this work, strain-rate jump tests and repeated stress relaxation experiments were conducted, to measure the SRS and activation volume of commercial pure ultrafine-grained tantalum prepared by equal channel angular pressing. The experimental relationship between the strain-rate sensitivity and the activation volume of these tantalum samples fits well with the new form of theoretical relationship developed in this investigation. Experimental data from literature on nickel confirms the new form as well. The new form of theoretical relationship between strain-rate sensitivity and activation volume can be applied for both bcc and fcc metals as long as the major plastic deformation mechanism is dislocation gliding.

  6. Analytical stiffness matrices with Green-Lagrange strain measure

    DEFF Research Database (Denmark)

    Pedersen, Pauli

    2005-01-01

    Separating the dependence on material and stress/strain state from the dependence on initial geometry, we obtain analytical secant and tangent stiffness matrices. For the case of a linear displacement triangle with uniform thickness and uniform constitutive behaviour closed-form results are listed......, directly suited for coding in a finite element program. The nodal positions of an element and the displacement assumption give three basic matrices of order three. These matrices do not depend on material and stress/strain state, and thus are unchanged during the necessary iterations for obtaining...

  7. Antimony implanted strained Si for nMOSFET applications

    OpenAIRE

    Zamani, Atieh

    2009-01-01

    Incorporation of implanted antimony (Sb) in strained-silicon (s-Si) formed on relaxed-SiGe virtual substrates (10 and 30% Ge) has been studied. The implantation doses were 5×1013- 5×1014 cm-2 with an energy of 20 keV. The activation of dopant was performed by an rapid thermal annealing (RTA) treatment at 700 and 800 °C for 30 sec. Projected range of this implantation is about 20 nm which was also confirmed by different techniques. The layers were analyzed in terms of strain relaxation, sheet ...

  8. Genome Sequence of Pseudomonas chlororaphis Strain 189

    Science.gov (United States)

    Town, Jennifer; Audy, Patrice; Boyetchko, Susan M.

    2016-01-01

    Pseudomonas chlororaphis strain 189 is a potent inhibitor of the growth of the potato pathogen Phytophthora infestans. We determined the complete, finished sequence of the 6.8-Mbp genome of this strain, consisting of a single contiguous molecule. Strain 189 is closely related to previously sequenced strains of P. chlororaphis. PMID:27340063

  9. Nucleon Form Factors

    Energy Technology Data Exchange (ETDEWEB)

    Cornelis de Jager

    2004-09-01

    The experimental and theoretical status of elastic electron scattering from the nucleon is reviewed. As a consequence of new experimental facilities, data of unprecedented precision have recently become available for the electromagnetic and the strange form factors of the nucleon.

  10. FORM, Diagrams and Topologies

    CERN Document Server

    Herzog, Franz; Ueda, Takahiro; Vermaseren, J A M; Vogt, Andreas

    2016-01-01

    We discuss a number of FORM features that are essential in the automatic processing of very large numbers of diagrams as used in the Forcer program for 4-loop massless propagator diagrams. Most of these features are new.

  11. VMS forms Output Tables

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — These output tables contain parsed and format validated data from the various VMS forms that are sent from any given vessel, while at sea, from the VMS devices on...

  12. Forms of Dystonia

    Science.gov (United States)

    ... the nervous system and inheritance). Doctors use these classifications to guide diagnosis and treatment. Forms of dystonia ... triggered by factors such as trauma, medication exposure, toxins. ► Trauma : Dystonia may follow trauma to the head ...

  13. Transplant Center Search Form

    Science.gov (United States)

    ... Your Story Give Us Feedback - A + A Transplant Center Search Form Welcome to the Blood & Marrow Transplant ... centers for patients with a particular disease. Transplant Center login Username: * Password: * Request new password Join BMT ...

  14. MAPS Appraisal Report Form

    CERN Multimedia

    HR Department

    2005-01-01

    As announced in Weekly Bulletin 48/2004, from now onwards, the paper MAPS appraisal report form has been replaced by an electronic form, which is available via EDH (on the EDH desktop under Other Tasks / HR & Training) No changes have been made to the contents of the form. Practical information will be available on the web page http://cern.ch/ais/projs/forms/maps/info.htm, and information meetings will be held on the following dates: 18 January 2005: MAIN AUDITORIUM (500-1-001) from 14:00 to 15:30. 20 January 2005: AB AUDITORIUM II (864-1-D02) from14:00 to 15:30. 24 January 2005: AT AUDITORIUM (30-7-018) from 10:00 to 11:30. Human Resources Department Tel. 73566

  15. NOAA Form 370 Database

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The data set contains information from submitted NOAA Form 370s, also known as the Fisheries Certificate of Origin, for imported shipments of frozen and/or...

  16. Access Customized Forms

    OpenAIRE

    Cosma Emil; Jeflea Victor

    2010-01-01

    By using Word, Excel or PowerPoint one can automate routine operations using the VBA language (Visual Basic for Applications). This language is also used in Access, allowing access to data stored in tables or queries. Thus, Access and VBA resources can be used together. Access is designed for programming forms and reports (among other things), so there won’t be found any of the VBA editor’s specific forms.

  17. Electromagetic proton form factors

    OpenAIRE

    Hussein, M Y

    2006-01-01

    The electromagnetic form factors are crucial to our understanding of the proton internal structure, and thus provide a strong constraint of the distributions of the charge and magnetization current within the proton. We adopted the quark-parton model for calculating and understanding the charge structure of the proton interms of the electromagnetic form factors. A remarkable agreement with the available experimental evidence is found.

  18. The Literary Form

    OpenAIRE

    COMPAGNON, Antoine

    2015-01-01

    Wondering if there was anything new that could be said about literary forms, styles and genres, I was pleasantly surprised to notice that automated word processing, with its iterative review and algorithmic method, suggests the possibility of statistically surveying literary styles and genres. Digital Humanities, which are poorly developed in France, could contribute to the analysis of literary forms and the renewal of the theory of genres. As is often the case, it was while seeking to reso...

  19. Strain Growth in Containment Vessels

    Institute of Scientific and Technical Information of China (English)

    DONG Q; LI Q M; ZHENG J Y

    2006-01-01

    Strain growth is a phenomenon observed in containment vessels subjected to internal blast loading.The elastic response of the vessel may become larger in a later stage compared to its response during the initial stage.The dynamic responses of infinitely long cylindrical containment vessels subjected to uniformly-distributed internal blast loading are studied using LS-DYNA.The development of bending modes and the interaction between the breathing mode and bending modes are observed.The methodology developed for dynamic elastic buckling analysis is employed to study the strain growth phenomenon in explosion containment vessels.It is shown that the dynamic instable vibration of a containment vessel is the basic mechanism of strain growth.

  20. Thermoelectric properties of strained silicon

    Energy Technology Data Exchange (ETDEWEB)

    Hinsche, Nicki F.; Zahn, Peter [Martin-Luther-Universitaet, Institut fuer Physik, Von-Seckendorff-Platz 1, 06120 Halle/S. (Germany); Mertig, Ingrid [Martin-Luther-Universitaet, Institut fuer Physik, Von-Seckendorff-Platz 1, 06120 Halle/S. (Germany); Max-Planck-Institut fuer Mikrostrukturphysik, Weinberg 2, D-06120 Halle (Germany)

    2011-07-01

    Starting from bulk silicon, we study the change in thermoelectric properties due to symmetry breaking in rolled-up and layered Si which might lead to nanostructured thermoelectrics. Valley splitting in strained Si caused by tetragonal distortion was studied recently with respect to the enhancement of electron mobility. Our results show that the tetragonal distortion has a strong influence on the electronic transport properties. The electronic structure is calculated self consistently within the framework of density functional theory. The transport properties are studied in the diffusive limit applying the Boltzmann theory in relaxation time approximation. In detail, the anisotropy of the electrical conductivity, the thermopower and the resulting powerfactor in the in-plane and off-plane directions are studied in dependence on strain, doping level and temperature. It is shown, that the powerfactor at a given temperature can be enhanced slightly by strain for p-doping, while no enhancement is obtained for n-doping.

  1. The correlation study of procalcitonin and C- reactive protein with children's bloodstream infections%降钙素原、C-反应蛋白与儿童血流感染的相关性研究

    Institute of Scientific and Technical Information of China (English)

    余烈中; 彭伟媛; 何静文; 赖挺方

    2016-01-01

    Objective To study the correlation of procalcitonin with children's bloodstream infections. Methods 300 cases of suspected bloodstream infections children in author hospital were selected,where simultaneous blood cultures and procalcitonin detected as research subjects.Comparison of two groups of children of serum procalcitonin levels,C- reactive protein levels,serum procalcitonin levels Gram bacteria cases between yin and yang. Results Children with blood culture-negative serum procalcitonin group,C- reactive protein and blood mean level culture positive infants compared, they had significant differences(P 0.05). Conclusion The serum procalcitonin level cloud be used as an early auxiliary diagnosis in bacterial infection, which may be conducive to implement antibiotic therapy.Meanwhile,the serum procalcitonin level cloud provide evidence for antibiotic therapy to avoid abuse of antibiotics.%目的:分析血清降钙素原与儿童血流感染之间的相关性。方法选择笔者所在医院同时进行血培养和降钙素原检测的300例疑似血流感染患儿为研究对象。比较两组患儿的血清降钙素原水平、C-反应蛋白水平及革兰阴阳菌病例间的血清降钙素原水平。结果血培养阴性组患儿的血清降钙素原、C-反应蛋白的均值水平与血培养阳性组患儿相比,差异有统计学意义(P<0.05)。革兰阳性菌49株(74.24%),革兰阴性菌17株(25.76%);革兰阳性菌组患者血清降钙素原均值水平显著低于格兰阴性菌组。两组菌株、血清降钙素原水平比较差异有统计学意义(P<0.05);C-反应蛋白比较差异不显著,差异无统计学意义(P>0.05)。结论血清血降钙素原水平可作为临床早期诊断细菌感染的辅助指标,从而及时有效地实施抗菌药物治疗。同时,血清降钙素原水平还可为抗菌药物应用提供有效的参照标准,对避免抗菌药物滥用具有重要的现实意义。

  2. 血流感染MRSA中的ST239克隆株快速检测与分析%Application of rapid detection of MRSA ST239 clones in bloodstream infections

    Institute of Scientific and Technical Information of China (English)

    姚杰; 杨凯; 刘周; 陈礼文; 周强; 管世鹤

    2015-01-01

    目的 评价多重PCR法对耐甲氧西林金黄色葡萄球菌(MRSA) ST239克隆株的快速检测及合肥地区血流感染MRSA的分子流行现状.方法 收集2008年至2013年安徽医科大学第一附属医院及第二附属医院临床分离的血流感染金黄色葡萄球菌的106株MRSA进行相关耐药性分析,并采用多重PCR技术对ST239型克隆株进行快速检测,同时运用多位点序列分型(MLST)加以确认及葡萄球菌染色体mec基因盒(SCCmec)分型分析.结果 106株血流感染金黄色葡萄球菌中MRSA有51株,占48.1%,MRSA均为多耐药菌,对红霉素、氨基糖苷类和喹诺酮类耐药率明显高于甲氧西林敏感金黄色葡萄球菌(MSSA),MRSA和MSSA对磺胺甲噁唑/甲氧苄啶的敏感率分别为86.3%和 94.5%;51株MRSA中有47株为ST239快速检测阳性,阳性率高达92.2%;随机选取20株ST239初筛阳性的MRSA经MLST验证和SCCmec分型后确认为MRSA-ST239-SCCmecⅢ型.结论 合肥地区血流感染MRSA近半数为多重耐药克隆MRSA-ST239-SCCmecⅢ型,运用多重PCR技术能够快速检测ST239克隆株.%Objective To evaluation the method of rapid detection of Methicillin-resistant Stphylococcus aureus (MRSA) ST239 clones with multiplex PCR assay and investigation of the epidemic status of MRSA blood stream infections in Hefei area.Methods Antibiotic susceptibility testing were applied to MRSA isolates from bloodstream infection,rapid screening and confirmation of MRSA ST239 clones by using multiplex PCR,Multilocus Sequence typing (MLST) and Staphyloccoccal Cassette Chromosome mec(SCCmec) typing.Results 51 of 106 clinic isolates Staphylococcus aureus were identified as MRSA,accounting for 48.1%.The resistance rate of MRSA to erythromycin,aminoglycosides and quinolone were significantly higher than Methicillin Sensitive Staphylococcus aureus (MSSA).Both MRSA and MSSA had a high sensitivity to cotrimoxazole,the sensivity rates were 86.3% and 94.5%,respectively; 47 of 51

  3. Spin transport in graphene superlattice under strain

    Science.gov (United States)

    Sattari, Farhad

    2016-09-01

    In this paper, the spin-dependent transport and the spin polarization properties for graphene superlattice with Rashba spin-orbit interaction (RSOI) in the presence of zigzag and armchair direction strain are studied. It is found that for the zigzag direction strain the angular range of the spin-inversion can be efficiently controlled by the strain strength. In addition, the efficiency of spin-inversion and spin-dependent conductivity decreases by increasing the strain strength. When the armchair direction strain is applied to a monolayer graphene superlattice the spin polarization can be observed and increases by increasing the strain strength, whereas for the zigzag direction strain it is zero.

  4. FormFlavor Manual

    CERN Document Server

    Evans, Jared A

    2016-01-01

    This manual describes the usage and structure of FormFlavor, a Mathematica-based tool for computing a broad list of flavor and CP observables in general new physics models. Based on the powerful machinery of FeynArts and FormCalc, FormFlavor calculates the one-loop Wilson coefficients of the dimension 5 and 6 Standard Model effective Lagrangian entirely from scratch. These Wilson coefficients are then evolved down to the low scale using one-loop QCD RGEs, where they are transformed into flavor and CP observables. The last step is accomplished using a model-independent, largely stand-alone package called FFObservables that is included with FormFlavor. The SM predictions in FFObservables include up-to-date references and accurate current predictions. Using the functions and modular structure provided by FormFlavor, it is straightforward to add new observables. Currently, FormFlavor is set up to perform these calculations for the general, non-MFV MSSM, but in principle it can be generalized to arbitrary FeynArts...

  5. EBSD ANALYSIS OF PHASE COMPOSITIONS OF TRIP STEEL ON VARIOUS STRAIN LEVELS

    OpenAIRE

    Ondřej Man; Libor Pantělejev; Zbyněk Pešina

    2009-01-01

    Flat test bar made of TRIP steel was sequentially strained in tension. Eeach deformation step was made on a predefined strain level in which the phase composition was measured using EBSD; the analyses were made ex-situ exactly in the same area of 30x30µm. Retained austenite (RA) was present in the form of elongated grains (plates) and roughly equiaxial ones. The RA content was initially 14.5% and decreased with imposed strain down to approximately 5% in selected strain range from 0% to 10%. T...

  6. Sorting the modes contributing to guidance in strain-induced graphene waveguides

    International Nuclear Information System (INIS)

    We propose a simple way of probing the number of modes contributing to the channeling in graphene waveguides which are formed by a gauge potential produced by mechanical strain. The energy mode structure for both homogeneous and non-homogeneous strain regimes is carefully studied using the continuum description of the Dirac equation. We found that high strain values privilege negative (instead of positive) group velocities throughout the guidance, sorting the types of modes flowing through it. We also show how the effect of a substrate-induced gap competes against the strain. (paper)

  7. Experimental evaluation of coating delamination in vinyl coated metal forming

    International Nuclear Information System (INIS)

    In this paper, a new evaluation and prediction method for coating delamination during sheet metal forming is presented. On the basis of the forming limit diagram (FLD), the current study evaluates the delamination of PET coating by using a cross cut specimen, dome test, and rectangular cup drawing test. Dome test specimens were subjected to biaxial, plane strain, and uniaxial deformation modes. Rectangular cup drawing test specimens were subjected to the deep drawing deformation mode, and compression deformation mode. A vinyl coated metal (VCM) sheet consists of three layers of polymer on the sheet metals: a protective film, a PET layer and a PVC layer. The areas with coating delamination were identified, and the results of the evaluation were plotted according to major and minor strain values, depicting coating delamination. The constructed delamination limit diagram (DLD) can be used to determine the forming limit of VCM during the complex press forming process. ARGUS (GOM) was employed to identify the strain value and deformation mode of the delaminated surface after the press forming. After identifying the areas of delamination, the DLD of the PET coating can be constructed in a format similar to that of the FLD. The forming limit of the VCM sheet can be evaluated using the superimposition of the delamination limit strain of the coating onto the FLD of VCM sheet. The experimental results showed that the proposed test method will support the sheet metal forming process design for VCM sheets. The assessment method presented in this study can be used to determine the delamination limit strain under plastic deformation of other polymer coated metals. The experimental results suggested that the proposed testing method is effective in evaluating delamination for specific applications

  8. Ribosome engineering to promote new crystal forms

    International Nuclear Information System (INIS)

    Truncation of ribosomal protein L9 in T. thermophilus allows the generation of new crystal forms and the crystallization of ribosome–GTPase complexes. Crystallographic studies of the ribosome have provided molecular details of protein synthesis. However, the crystallization of functional complexes of ribosomes with GTPase translation factors proved to be elusive for a decade after the first ribosome structures were determined. Analysis of the packing in different 70S ribosome crystal forms revealed that regardless of the species or space group, a contact between ribosomal protein L9 from the large subunit and 16S rRNA in the shoulder of a neighbouring small subunit in the crystal lattice competes with the binding of GTPase elongation factors to this region of 16S rRNA. To prevent the formation of this preferred crystal contact, a mutant strain of Thermus thermophilus, HB8-MRCMSAW1, in which the ribosomal protein L9 gene has been truncated was constructed by homologous recombination. Mutant 70S ribosomes were used to crystallize and solve the structure of the ribosome with EF-G, GDP and fusidic acid in a previously unobserved crystal form. Subsequent work has shown the usefulness of this strain for crystallization of the ribosome with other GTPase factors

  9. Successful Salvage of Central Venous Catheters in Patients with Catheter-Related or Central Line-Associated Bloodstream Infections by Using a Catheter Lock Solution Consisting of Minocycline, EDTA, and 25% Ethanol.

    Science.gov (United States)

    Raad, Issam; Chaftari, Anne-Marie; Zakhour, Ramia; Jordan, Mary; Al Hamal, Zanaib; Jiang, Ying; Yousif, Ammar; Garoge, Kumait; Mulanovich, Victor; Viola, George M; Kanj, Soha; Pravinkumar, Egbert; Rosenblatt, Joel; Hachem, Ray

    2016-06-01

    In cancer patients with long-term central venous catheters (CVC), removal and reinsertion of a new CVC at a different site might be difficult because of the unavailability of accessible vascular sites. In vitro and animal studies showed that a minocycline-EDTA-ethanol (M-EDTA-EtOH) lock solution may eradicate microbial organisms in biofilms, hence enabling the treatment of central line-associated bloodstream infections (CLABSI) while retaining the catheter in situ Between April 2013 and July 2014, we enrolled 30 patients with CLABSI in a prospective study and compared them to a historical group of 60 patients with CLABSI who had their CVC removed and a new CVC inserted. Each catheter lumen was locked with an M-EDTA-EtOH solution for 2 h administered once daily, for a total of 7 doses. Patients who received locks had clinical characteristics that were comparable to those of the control group. The times to fever resolution and microbiological eradication were similar in the two groups. Patients with the lock intervention received a shorter duration of systemic antibiotic therapy than that of the control patients (median, 11 days versus 16 days, respectively; P < 0.0001), and they were able to retain their CVCs for a median of 74 days after the onset of bacteremia. The M-EDTA-EtOH lock was associated with a significantly decreased rate of mechanical and infectious complications compared to that of the CVC removal/reinsertion group, who received a longer duration of systemic antimicrobial therapy. (This study has been registered at ClinicalTrials.gov under registration no. NCT01539343.). PMID:27001822

  10. Effects of a strain rate sensitive material on the optimization of an hydroforming process

    OpenAIRE

    Zhang, Cunsheng; Leotoing, Lionel; Guines, Dominique; Ragneau, Eric

    2008-01-01

    The hydroforming process of a T-tube is simulated with the finite element code ABAQUS. The influence of the internal pressure and the axial displacement levels on the final tube quality is evaluated through a "process diagram". Due to the strain rate range observed during the process, the strain rate sensitivity of the material is considered for the determination of the forming limit curves and for simulation of the process. Theoretical and numerical evaluation of the forming limit curves sho...

  11. Myocardial Strain and Strain Rate Imaging: Comparison between Doppler Derived Strain Imaging and Speckle Tracking Echocardiography

    Directory of Open Access Journals (Sweden)

    Anita Sadeghpour

    2013-05-01

    Full Text Available Regional myocardial function has been traditionally assessed by visual estimation (1. Echocardiographic strain imaging which is known as deformation imaging, has been emerged as a quantitative technique to accurately estimate regional myocardial function and contractility. Currently, strain imaging has been regarded as a research tool in the most echocardiography laboratories. However, in recent years, strain imaging has gain momentum in daily clinical practice (2. The following two techniques have dominated the research arena of echocardiography: (1 Doppler based tissue velocity measurements, frequently referred to tissue Doppler or myocardial Doppler, and (2 speckle tracking on the basis of displacement measurements (3. Over the past two decades, Tissue Doppler Imaging (TDI and Doppler –derived strain (S and strain rate (SR imaging were introduced to quantify regional myocardial function. However, Doppler–derived strain variables faced criticisms, with regard to the angle dependency, noise interference, and substantial intraobserver and interobserver variability. The angle dependency is the major weakness of Doppler based methodology; however, it has the advantage of online measurements of velocities and time intervals with excellent temporal resolution, which is essential for the assessment of ischemia (4. Speckle-tracking echocardiography (STE or Non Doppler 2D strain echocardiography is a relatively new, largely angle-independent technique that analyzes motion by tracking natural acoustic reflections and interference patterns within an ultrasonic window. The image-processing algorithm tracks elements with approximately 20 to 40 pixels containing stable patterns and are described as ‘‘speckles’’ or ‘‘fingerprints’’. The speckles seen in grayscale B-mode (2D images are tracked consecutively frame to frame (5, 6. Assessment of 2D strain by STE is a semiautomatic method that requires definition of the myocardium

  12. Integrated Manufacturing of Aerospace Components by Superplastic Forming Technology

    Directory of Open Access Journals (Sweden)

    Ju Min Kyung

    2015-01-01

    Full Text Available Aerospace vehicle requires lightweight structures to obtain weight saving and fuel efficiency. It is known that superplastic characteristics of some materials provide significant opportunity for forming complicated, lightweight components of aerospace structure. One of the most important advantages of using superplastic forming process is its simplicity to form integral parts and economy in tooling[1]. For instance, it can be applied to blow-forming, in which a metal sheet is deformed due to the pressure difference of hydrostatic gas on both sides of the sheet. Since the loading medium is gas pressure difference, this forming is different from conventional sheet metal forming technique in that this is stress-controlled rather than strain and strain rate controlled. This method is especially advantageous when several sheet metals are formed into complex shapes. In this study, it is demonstrated that superplastic forming process with titanium and steel alloy can be applied to manufacturing lightweight integral structures of aerospace structural parts and rocket propulsion components. The result shows that the technology to design and develop the forming process of superplastic forming can be applied for near net shape forming of a complex contour of a thrust chamber and a toroidal fuel tank.

  13. Draft Genome Sequences of Seven Thermophilic Spore-Forming Bacteria Isolated from Foods That Produce Highly Heat-Resistant Spores, Comprising Geobacillus spp., Caldibacillus debilis, and Anoxybacillus flavithermus

    Science.gov (United States)

    Berendsen, Erwin M.; Wells-Bennik, Marjon H. J.; Krawczyk, Antonina O.; de Jong, Anne; van Heel, Auke; Holsappel, Siger; Eijlander, Robyn T.

    2016-01-01

    Here, we report the draft genomes of five strains of Geobacillus spp., one Caldibacillus debilis strain, and one draft genome of Anoxybacillus flavithermus, all thermophilic spore-forming Gram-positive bacteria. PMID:27151781

  14. Photoacoustic spectroscopy of Entamoeba histolytica strains

    Science.gov (United States)

    Acosta-Avalos, D.; Alvarado-Gil, J. J.; Silva, E. F.; Orozco, E.; de Menezes, L. F.; Vargas, H.

    2005-06-01

    Pathogenic and non-pathogenic strains of E. histolytica are studied using photoacoustic spectroscopy. It is shown that the pathogenic strain presents a spectrum similar to that of iron sulfur proteins. The non-pathogenic strain does not show any relevant absorption at the studied wavelength range. The differences observed between the optical absorption spectra of both strains opens the possibility of using photoacoustic spectroscopy as a reliable and simple technique to identify different types of E. histolytica strains.

  15. The clinical value of PCT levels in bacteria identification in ICU patients with bloodstream infection%血清降钙素原对ICU血流感染患者菌种鉴别中的应用研究

    Institute of Scientific and Technical Information of China (English)

    王建; 庄国华; 牛野; 李宏; 夏建萍

    2015-01-01

    目的 探讨血清降钙素原(PCT)水平测定在ICU血流感染患者菌种鉴别中的应用价值.方法 对本院ICU 2007年12月至2013年12月收治的540例血流感染患者的PCT水平进行检测并对患者标本分离的菌种进行鉴别,分析PCT水平在鉴别血流感染菌种的有效性.结果 540例血流感染患者中,G+菌感染患者比例最高(49.63%),G-菌感染患者比例次之(38.52%),真菌感染患者比例最低(11.85%),三者间差异有统计学意义(P<0.05).G-菌感染组PCT水平及阳性率均显著高于G+菌感染组和真菌感染组,差异有统计学意义(P<0.05),G+菌和真菌感染组之间差异无统计学意义(P>0.05).PCT界定为2.04 ng/ml时,血清PCT水平区分G-和G+的灵敏度和特异度分别为82.18%和76.09%;PCT界定为3.16 ng,/ml时,血清PCT水平鉴别血流感染G-菌与真菌种的灵敏度和特异度分别为59.42%和65.73%.结论 应用血清PCT水平鉴别G-菌与G+菌、真菌所致血流感染具有较高的临床价值,PCT水平≥2.04 ng/ml时,发生G-菌感染几率较大,PCT水平对G+菌与真菌的鉴别准确度较差.%Objective To investigate the clinical value of procalcitonin (PCT) levels in bacteria identification in intensive care unit (ICU) patients with bloodstream infection.Methods There were 540 cases of patients with bloodstream infection in our ICU between December 2007 and December 2013.The PCT levels and bacteria were identified.The application effectiveness of PCT levels in the bacteria identification was studied.Results The G+ bacteria infection rate was 49.63% (268/540),G-bacteria infection rate was 38.52% (208/540),and the fungal infection rate was 11.85% (64/540).The patients of G-bacteria had significant difference with G + bacteria and fungal infection (P < 0.05).The PCT average and positive rate of G-bacteria were significantly higher than G + bacteria and fungi group (P < 0.05),respectively.G+ bacteria and fungi infection did not

  16. Comparative waste forms study

    International Nuclear Information System (INIS)

    A number of alternative process and waste form options exist for the immobilization of nuclear wastes. Although data exists on the characterization of these alternative waste forms, a straightforward comparison of product properties is difficult, due to the lack of standardized testing procedures. The characterization study described in this report involved the application of the same volatility, mechanical strength and leach tests to ten alternative waste forms, to assess product durability. Bulk property, phase analysis and microstructural examination of the simulated products, whose waste loading varied from 5% to 100% was also conducted. The specific waste forms investigated were as follows: Cold Pressed and Sintered PW-9 Calcine; Hot Pressed PW-9 Calcine; Hot Isostatic Pressed PW-9 Calcine; Cold Pressed and Sintered SPC-5B Supercalcine; Hot Isostatic pressed SPC-5B Supercalcine; Sintered PW-9 and 50% Glass Frit; Glass 76-68; Celsian Glass Ceramic; Type II Portland Cement and 10% PW-9 Calcine; and Type II Portland Cement and 10% SPC-5B Supercalcine. Bulk property data were used to calculate and compare the relative quantities of waste form volume produced at a spent fuel processing rate of 5 metric ton uranium/day. This quantity ranged from 3173 L/day (5280 Kg/day) for 10% SPC-5B supercalcine in cement to 83 L/day (294 Kg/day) for 100% calcine. Mechanical strength, volatility, and leach resistance tests provide data related to waste form durability. Glass, glass-ceramic and supercalcine ranked high in waste form durability where as the 100% PW-9 calcine ranked low. All other materials ranked between these two groupings

  17. Molecular Epidemiology and Drug Resistance of Acinetobacter baumannii Isolated from Hospitals in Southern Poland: ICU as a Risk Factor for XDR Strains.

    Science.gov (United States)

    Chmielarczyk, Agnieszka; Pilarczyk-Żurek, Magdalena; Kamińska, Wanda; Pobiega, Monika; Romaniszyn, Dorota; Ziółkowski, Grzegorz; Wójkowska-Mach, Jadwiga; Bulanda, Małgorzata

    2016-06-01

    The objectives of the present study were to investigate the carbapenemase and metallo-beta-lactamase genes of Acinetobacter baumannii clinical isolates by polymerase chain reaction (PCR) and real time PCR and to determine the molecular epidemiology of the strains using the DiversiLab tool. From these data, correlations between drug resistance, resistance genes, and epidemiological clones may be revealed. The study was conducted on 125 A. baumannii collected over the 2013 year. The majority of the isolates from both intensive care unit (ICU) and non-ICU cases originated from pneumonia infections (79.2%), isolates from blood infections accounted for 17.6% and 3.2% were from meningitis infections. In the ICU cases compared with the non-ICU cases, bloodstream infections were more frequently diagnosed (19.2% vs. 11.5%). Sixty percent of A. baumannii strains were resistant to all the antimicrobials tested with the exception of colistin. All strains were susceptible to colistin and polymyxin B. Extensively drug-resistant (XDR) strains accounted for 80.8% of the isolates tested and these XDR strains were more frequently isolated from ICU cases than from non-ICU cases (93.9% vs. 30.8%). Among the 101 isolates of A. baumannii exhibiting the XDR pattern of resistance, 80 possessed the blaOXA-24 gene and 29 had the blaOXA-23 gene. Only two isolates possessed the blaVIM gene. The presence of the ISAba1element was confirmed among 10 strains from patients hospitalized in the ICU. Using repetitive extragenic palindromic sequence PCR (DiversiLab typing), six clones and 12 unique strains were identified, of which two clones dominated. Most isolates belonging to clone 1 (66.7%) and clone 2 (85.5%) were susceptible only to colistin. In summary, it is clear from our findings and those of other studies that carbapenem resistance among A. baumannii strains presents a serious clinical problem worldwide. Furthermore, the presence of XDR international clone II in ICUs poses a potential risk

  18. The effect of pre-strain on hydrogen embrittlement in 310S stainless steel

    International Nuclear Information System (INIS)

    Highlights: • Pre-straining increased the resistance to hydrogen embrittlement (HE) in STS 310S. • The improved HE was due to the suppression of a ductile to brittle fracture transition. • Ductility was kept due to suppressed twinning and hydrogen delivery by pre-strain. - Abstract: The effect of pre-strain on hydrogen embrittlement (HE) was investigated using STS 310S, considering its application to a ferrous cylinder liner for hydrogen storage. Whereas tensile strength was insignificantly influenced by hydrogen charging, elongation was decreased due to a ductile to brittle fracture transition. However, the degree of the reduction in elongation by hydrogen charging was decreased with increasing pre-strain, indicating that pre-straining improved the resistance to HE by suppressing the fracture transition. The cause for suppression of the fracture transition by pre-strain was investigated through the analyses of strain hardening behavior and thermal desorption of hydrogen. The strain hardening rate curves of annealed and pre-strained specimens was divided into several stages, which were greatly affected by primary and secondary twinning, regardless of hydrogen charging. This strain hardening analysis showed that pre-straining suppressed mechanical twinning during tensile deformation. The thermal desorption analysis revealed that the migration of diffusible hydrogen atoms to twin boundaries was hindered by pre-strain. Therefore, the reason why pre-strain suppressed the fracture transition to improve the resistance to HE was because pre-strain hindered both mechanical twinning during tensile deformation and hydrogen delivery to twin boundaries not to form highly hydrogen-concentrated twin boundaries

  19. Comparison of quantitative and qualitative antibody-producing cell responses to lipopolysaccharide in cell walls of the bacterial form and in membranes of the protoplast L-form of Proteus mirabilis.

    OpenAIRE

    Karch, H; Nixdorff, K

    1980-01-01

    Membranes of the stable protoplast L-form of Proteus mirabilis strain VI were highly immunogenic carriers of lipopolysaccharide when compared with the immune responses to lipopolysaccharide contained in cell walls of the bacterial form of this organism.

  20. Isolation of Staphylococcus aureus L forms from experimentally induced bovine mastitis.

    OpenAIRE

    Owens, W E

    1987-01-01

    Bacterial L forms were isolated from milk samples of dairy cattle infected experimentally with Staphylococcus aureus. Initially, bacterial L forms were induced in vitro from 12 of 44 S. aureus strains isolated from bovine mastitis. Cows were experimentally infected in two experiments with strains shown in vitro to be easily inducible to L form and with S. aureus Newbould 305. Each quarter of the mammary gland was infected with either 10(3) or 10(6) CFU of the test strains. Treatment was initi...