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Sample records for gonorrhoeae lipooligosaccharide directs

  1. Variation of Neisseria gonorrhoeae lipooligosaccharide directs dendritic cell-induced T helper responses.

    Directory of Open Access Journals (Sweden)

    Sandra J van Vliet

    2009-10-01

    Full Text Available Gonorrhea is one of the most prevalent sexually transmitted diseases in the world. A naturally occurring variation of the terminal carbohydrates on the lipooligosaccharide (LOS molecule correlates with altered disease states. Here, we investigated the interaction of different stable gonoccocal LOS phenotypes with human dendritic cells and demonstrate that each variant targets a different set of receptors on the dendritic cell, including the C-type lectins MGL and DC-SIGN. Neisseria gonorrhoeae LOS phenotype C constitutes the first bacterial ligand to be described for the human C-type lectin receptor MGL. Both MGL and DC-SIGN are locally expressed at the male and female genital area, the primary site of N. gonorrhoeae infection. We show that targeting of different C-type lectins with the N. gonorrhoeae LOS variants results in alterations in dendritic cell cytokine secretion profiles and the induction of distinct adaptive CD4(+ T helper responses. Whereas N. gonorrhoeae variant A with a terminal N-acetylglucosamine on its LOS was recognized by DC-SIGN and induced significantly more IL-10 production, phenotype C, carrying a terminal N-acetylgalactosamine, primarily interacted with MGL and skewed immunity towards the T helper 2 lineage. Together, our results indicate that N. gonorrhoeae LOS variation allows for selective manipulation of dendritic cell function, thereby shifting subsequent immune responses in favor of bacterial survival.

  2. Lipooligosaccharide structure is an important determinant in the resistance of Neisseria gonorrhoeae to antimicrobial agents of innate host defense

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    Jacqueline T Balthazar

    2011-02-01

    Full Text Available The strict human pathogen Neisseria gonorrhoeae has caused the sexually transmitted infection termed gonorrhea for thousands of years. Over the millennia, the gonococcus has likely evolved mechanisms to evade host defense systems that operate on the genital mucosal surfaces in both males and females. Past research has shown that the presence or modification of certain cell envelope structures can significantly impact levels of gonococcal susceptibility to host-derived antimicrobial compounds that bathe genital mucosal surfaces and participate in innate host defense against invading pathogens. In order to facilitate the identification of gonococcal genes that are important in determining levels of bacterial susceptibility to mediators of innate host defense, we used the Himar I mariner in vitro mutagenesis system to construct a transposon insertion library in strain F62. As proof of principle that this strategy would be suitable for this purpose, we screened the library for mutants expressing decreased susceptibility to the bacteriolytic action of normal human serum (NHS. We found that a transposon insertion in the lgtD gene, which encodes an N-acetylgalactosamine transferase involved in the extension of the α-chain of lipooligosaccharide (LOS, could confer decreased susceptibility of strain F62 to complement-mediated killing by NHS. By complementation and chemical analyses, we demonstrated both linkage of the transposon insertion to the NHS-resistance phenotype and chemical changes in LOS structure that resulted from loss of LgtD production. Further truncation of the LOS α-chain or loss of phosphoethanolamine (PEA from the lipid A region of LOS also impacted levels of NHS-resistance. PEA decoration of lipid A also increased gonococcal resistance to the model cationic antimicrobial polymyxin B. Taken together, we conclude that the Himar I mariner in vitro mutagenesis procedure can facilitate studies on structures involved in gonococcal

  3. Utilizing CMP-Sialic Acid Analogs to Unravel Neisseria gonorrhoeae Lipooligosaccharide-Mediated Complement Resistance and Design Novel Therapeutics.

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    Sunita Gulati

    2015-12-01

    Full Text Available Neisseria gonorrhoeae deploys a novel immune evasion strategy wherein the lacto-N-neotetraose (LNnT structure of lipooligosaccharide (LOS is capped by the bacterial sialyltransferase, using host cytidine-5'-monophosphate (CMP-activated forms of the nine-carbon nonulosonate (NulO sugar N-acetyl-neuraminic acid (Neu5Ac, a sialic acid (Sia abundant in humans. This allows evasion of complement-mediated killing by recruiting factor H (FH, an inhibitor of the alternative complement pathway, and by limiting classical pathway activation ("serum-resistance". We utilized CMP salts of six additional natural or synthetic NulOs, Neu5Gc, Neu5Gc8Me, Neu5Ac9Ac, Neu5Ac9Az, legionaminic acid (Leg5Ac7Ac and pseudaminic acid (Pse5Ac7Ac, to define structural requirements of Sia-mediated serum-resistance. While all NulOs except Pse5Ac7Ac were incorporated into the LNnT-LOS, only Neu5Gc incorporation yielded high-level serum-resistance and FH binding that was comparable to Neu5Ac, whereas Neu5Ac9Az and Leg5Ac7Ac incorporation left bacteria fully serum-sensitive and did not enhance FH binding. Neu5Ac9Ac and Neu5Gc8Me rendered bacteria resistant only to low serum concentrations. While serum-resistance mediated by Neu5Ac was associated with classical pathway inhibition (decreased IgG binding and C4 deposition, Leg5Ac7Ac and Neu5Ac9Az incorporation did not inhibit the classical pathway. Remarkably, CMP-Neu5Ac9Az and CMP-Leg5Ac7Ac each prevented serum-resistance despite a 100-fold molar excess of CMP-Neu5Ac in growth media. The concomitant presence of Leg5Ac7Ac and Neu5Ac on LOS resulted in uninhibited classical pathway activation. Surprisingly, despite near-maximal FH binding in this instance, the alternative pathway was not regulated and factor Bb remained associated with bacteria. Intravaginal administration of CMP-Leg5Ac7Ac to BALB/c mice infected with gonorrhea (including a multidrug-resistant isolate reduced clearance times and infection burden. Bacteria recovered

  4. Insertions in the OCL1 locus of Acinetobacter baumannii lead to shortened lipooligosaccharides

    Science.gov (United States)

    Kenyon, Johanna J.; Holt, Kathryn E.; Pickard, Derek; Dougan, Gordon; Hall, Ruth M.

    2014-01-01

    Genomes of 82 Acinetobacter baumannii global clones 1 (GC1) and 2 (GC2) isolates were sequenced and different forms of the locus predicted to direct synthesis of the outer core (OC) of the lipooligosaccharide were identified. OCL1 was in all GC2 genomes, whereas GC1 isolates carried OCL1, OCL3 or a new locus, OCL5. Three mutants in which an insertion sequence (ISAba1 or ISAba23) interrupted OCL1 were identified. Isolates with OCL1 intact produced only lipooligosaccharide, while the mutants produced lipooligosaccharide of reduced molecular weight. Thus, the assignment of the OC locus as that responsible for the synthesis of the OC is correct. PMID:24861001

  5. Fatty Acyl Chains of Mycobacterium marinum Lipooligosaccharides

    Science.gov (United States)

    Rombouts, Yoann; Alibaud, Laeticia; Carrère-Kremer, Séverine; Maes, Emmanuel; Tokarski, Caroline; Elass, Elisabeth; Kremer, Laurent; Guérardel, Yann

    2011-01-01

    We have recently established the fine structure of the glycan backbone of lipooligosaccharides (LOS-I to LOS-IV) isolated from Mycobacterium marinum, a close relative of Mycobacterium tuberculosis. These studies culminated with the description of an unusual terminal N-acylated monosaccharide that confers important biological functions to LOS-IV, such as macrophage activation, that may be relevant to granuloma formation. It was, however, also suggested that the lipid moiety was required for LOSs to exert their immunomodulatory activity. Herein, using highly purified LOSs from M. marinum, we have determined through a combination of mass spectrometric and NMR techniques, the structure and localization of the fatty acids composing the lipid moiety. The occurrence of two distinct polymethyl-branched fatty acids presenting specific localizations is consistent with the presence of two highly related polyketide synthases (Pks5 and Pks5.1) in M. marinum and presumably involved in the synthesis of these fatty acyl chains. In addition, a bioinformatic search permitted us to identify a set of enzymes potentially involved in the biosynthesis or transfer of these lipids to the LOS trehalose unit. These include MMAR_2343, a member of the Pap (polyketide-associated protein) family, that acylates trehalose-based glycolipids in M. marinum. The participation of MMAR_2343 to LOS assembly was demonstrated using a M. marinum mutant carrying a transposon insertion in the MMAR_2343 gene. Disruption of MMAR_2343 resulted in a severe LOS breakdown, indicating that MMAR_2343, hereafter designated PapA4, fulfills the requirements for LOS acylation and assembly. PMID:21803773

  6. Characterization of lipooligosaccharide-biosynthetic loci of Campylobacter jejuni reveals new lipooligosaccharide classes: Evidence of mosaic organizations

    NARCIS (Netherlands)

    C.T. Parker (Craig); M. Gilbert (Michel); N. Yuki (Nobuhiro); H.P. Endtz (Hubert); R.E. Mandrell (Robert)

    2008-01-01

    textabstractThe lipooligosaccharide (LOS) biosynthesis region is one of the more variable genomic regions between strains of Campylobacter jejuni. Indeed, eight classes of LOS biosynthesis loci have been established previously based on gene content and organization. In this study, we characterize

  7. Type I interferon induction by Neisseria gonorrhoeae: Dual requirement of cyclic GMP-AMP synthase and Toll-like receptor 4

    OpenAIRE

    Andrade, Warrison A.; Agarwal, Sarika; Mo, Shunyan; Shaffer, Scott A.; Dillard, Joseph P.; Schmidt, Tobias; Hornung, Veit; Fitzgerald, Katherine A.; Kurt-Jones, Evelyn A.; Golenbock, Douglas T.

    2016-01-01

    The innate immune system is the first line of defense against Neisseria gonorrhoeae (GC). Exposure of cells to GC lipooligosaccharides induces a strong immune response, leading to type I interferon (IFN) production via TLR4/MD-2. In addition to living freely in the extracellular space, GC can invade the cytoplasm to evade detection and elimination. Double-stranded DNA introduced into the cytosol binds and activates the enzyme cyclic-GMP-AMP synthase (cGAS), which produces 2′3′-cGAMP and trigg...

  8. New futures of sialyated lipo-oligosaccharide structures in campylobacter jejuni

    NARCIS (Netherlands)

    R.P.L. Louwen (Rogier)

    2012-01-01

    textabstractThe zoonotic human enteric pathogen Campylobacter jejuni is acquired by humans through contaminated water, poultry, shellfish and pets 1. Motility, chemotaxis, glycosylation and lipo-oligosaccharides (LOS) structures are all different virulence features exploited by C. jejuni to adhere,

  9. Temperature-dependent phenotypic variation of Campylobacter jejuni lipooligosaccharides

    LENUS (Irish Health Repository)

    Semchenko, Evgeny A

    2010-11-30

    Abstract Background Campylobacter jejuni is a major bacterial cause of food-borne enteritis, and its lipooligosaccharide (LOS) plays an initiating role in the development of the autoimmune neuropathy, Guillain-Barré syndrome, by induction of anti-neural cross-reactive antibodies through ganglioside molecular mimicry. Results Herein we describe the existence and heterogeneity of multiple LOS forms in C. jejuni strains of human and chicken origin grown at 37°C and 42°C, respectively, as determined on sodium dodecyl sulphate-polyacrylamide electrophoresis gels with carbohydrate-specific silver staining and blotting with anti-ganglioside ligands, and confirmed by nuclear magnetic resonance (NMR) spectroscopy. The C. jejuni NCTC 11168 original isolate (11168-O) was compared to its genome-sequenced variant (11168-GS), and both were found to have a lower-Mr LOS form, which was different in size and structure to the previously characterized higher-Mr form bearing GM1 mimicry. The lower-Mr form production was found to be dependent on the growth temperature as the production of this form increased from ~5%, observed at 37°C to ~35% at 42°C. The structure of the lower-Mr form contained a β-D-Gal-(1→3)-β-D-GalNAc disaccharide moiety which is consistent with the termini of the GM1, asialo-GM1, GD1, GT1 and GQ1 gangliosides, however, it did not display GM1 mimicry as assessed in blotting studies but was shown in NMR to resemble asialo-GM1. The production of multiple LOS forms and lack of GM1 mimicry was not a result of phase variation in the genes tested of NCTC 11168 and was also observed in most of the human and chicken isolates of C. jejuni tested. Conclusion The presence of differing amounts of LOS forms at 37 and 42°C, and the variety of forms observed in different strains, indicate that LOS form variation may play a role in an adaptive mechanism or a stress response of the bacterium during the colonization of different hosts.

  10. Cephalosporin resistance in Neisseria gonorrhoeae

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    Manju Bala

    2010-01-01

    Full Text Available Gonorrhea, a disease of public health importance, not only leads to high incidence of acute infections and complications but also plays a major role in facilitating human immunodeficiency virus (HIV acquisition and transmission. One of the major public health needs for gonorrhea control is appropriate, effective treatment. However, treatment options for gonorrhea are diminishing as Neisseria gonorrhoeae have developed resistance to several antimicrobial drugs such as sulfonamides, penicillin, tetracyclines and quinolones. Antimicrobial resistance (AMR surveillance of N. gonorrhoeae helps establish and maintain the efficacy of standard treatment regimens. AMR surveillance should be continuous to reveal the emergence of new resistant strains, monitor the changing patterns of resistance, and be able to update treatment recommendations so as to assist in disease control. Current treatment guidelines recommend the use of single dose injectable or oral cephalosporins. The emergence and spread of cephalosporin resistant and multi drug resistant N. gonorrhoeae strains, represents a worrying trend that requires monitoring and investigation. Routine clinical laboratories need to be vigilant for the detection of such strains such that strategies for control and prevention could be reviewed and revised from time to time. It will be important to elucidate the genetic mechanisms responsible for decreased susceptibility and future resistance. There is also an urgent need for research of safe, alternative anti-gonococcal compounds that can be administered orally and have effective potency, allowing high therapeutic efficacy (greater than 95.0% cure rate.

  11. Phytomedicine versus Gonorrhoea: The Bapedi Experience ...

    African Journals Online (AJOL)

    Phytomedicine versus Gonorrhoea: The Bapedi Experience. LJC Erasmus, MJ Potgieter, SS Semenya, SJ Lennox. Abstract. Records regarding the phytomedicine employed by the Bapedi are almost non-existent. This is the first study of herbal remedies used by Bapedi traditional healers to treat gonorrhoea, of concern as it ...

  12. Activation of Murine Macrophages by Lipoprotein and Lipooligosaccharide of Treponema denticola

    OpenAIRE

    Rosen, Graciela; Sela, Michael N.; Naor, Ronit; Halabi, Amal; Barak, Vivian; Shapira, Lior

    1999-01-01

    We have recently demonstrated that the periodontopathogenic oral spirochete Treponema denticola possesses membrane-associated lipoproteins in addition to lipooligosaccharide (LOS). The aim of the present study was to test the potential of these oral spirochetal components to induce the production of inflammatory mediators by human macrophages, which in turn may stimulate tissue breakdown as observed in periodontal diseases. An enriched lipoprotein fraction (dLPP) from T. denticola ATCC 35404 ...

  13. Algunas consideraciones sobre Neisseria gonorrhoeae

    OpenAIRE

    Pardi, Germán; Pérez, María Fernanda; Pacheco, Aura; Mata de Henning, Magdalena

    2004-01-01

    En el presente artículo, se describen los principales aspectos relacionados con Neisseria gonorrhoeae, microorganismo que se puede encontrar presente como parte de la microbiota transitoria o transeúnte de la cavidad bucal de algunos individuos, donde se destacan: Historia, taxonomía, características morfológicas, fisiológicas y de cultivo, ultraestructura, estructura antigénica, así como algunas consideraciones en referencia a la ecología y a los mecanismos de patogenicidad por parte de esta...

  14. Phosphoethanolamine Modification of Neisseria gonorrhoeae Lipid A Reduces Autophagy Flux in Macrophages.

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    Susu M Zughaier

    Full Text Available Autophagy, an ancient homeostasis mechanism for macromolecule degradation, performs an important role in host defense by facilitating pathogen elimination. To counteract this host defense strategy, bacterial pathogens have evolved a variety of mechanisms to avoid or otherwise dysregulate autophagy by phagocytic cells so as to enhance their survival during infection. Neisseria gonorrhoeae is a strictly human pathogen that causes the sexually transmitted infection, gonorrhea. Phosphoethanolamine (PEA addition to the 4' position of the lipid A (PEA-lipid A moiety of the lipooligosaccharide (LOS produced by gonococci performs a critical role in this pathogen's ability to evade innate defenses by conferring decreased susceptibility to cationic antimicrobial (or host-defense peptides, complement-mediated killing by human serum and intraleukocytic killing by human neutrophils compared to strains lacking this PEA decoration. Heretofore, however, it was not known if gonococci can evade autophagy and if so, whether PEA-lipid A contributes to this ability. Accordingly, by using murine macrophages and human macrophage-like phagocytic cell lines we investigated if PEA decoration of gonococcal lipid A modulates autophagy formation. We report that infection with PEA-lipid A-producing gonococci significantly reduced autophagy flux in murine and human macrophages and enhanced gonococcal survival during their association with macrophages compared to a PEA-deficient lipid A mutant. Our results provide further evidence that PEA-lipid A produced by gonococci is a critical component in the ability of this human pathogen to evade host defenses.

  15. Functional analysis of the Gonococcal Genetic Island of Neisseria gonorrhoeae.

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    Emilia Pachulec

    Full Text Available Neisseria gonorrhoeae is an obligate human pathogen that is responsible for the sexually-transmitted disease gonorrhea. N. gonorrhoeae encodes a T4SS within the Gonococcal Genetic Island (GGI, which secretes ssDNA directly into the external milieu. Type IV secretion systems (T4SSs play a role in horizontal gene transfer and delivery of effector molecules into target cells. We demonstrate that GGI-like T4SSs are present in other β-proteobacteria, as well as in α- and γ-proteobacteria. Sequence comparison of GGI-like T4SSs reveals that the GGI-like T4SSs form a highly conserved unit that can be found located both on chromosomes and on plasmids. To better understand the mechanism of DNA secretion by N. gonorrhoeae, we performed mutagenesis of all genes encoded within the GGI, and studied the effects of these mutations on DNA secretion. We show that genes required for DNA secretion are encoded within the yaa-atlA and parA-parB regions, while genes encoded in the yfeB-exp1 region could be deleted without any effect on DNA secretion. Genes essential for DNA secretion are encoded within at least four different operons.

  16. Antimicrobial susceptibility pattern of Neisseria gonorrhoeae ...

    African Journals Online (AJOL)

    The high levels of bacterial resistance against ampicillin, ciprofloxacin, tetracycline, penicillin and spectinomycin, should be taken into account in developing any new guidelines in the management of the infection. Keywords: Neisseria gonorrhoeae, Female infertility Drug Resistance, Ciprofloxacin, Tetracycline, ...

  17. FREKUENSI KUMAN Neisseriae gonorrhoeae YANG MENGINFEKSI WANITA USIA ANAK DI PADANG

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    Elizabeth Bahar

    2008-09-01

    negative coccus is the disease induced the problem both in the developing countries and super power countries event world wide. In addition to reproduction health, it close relate to sexual behaviour. From comerstone of social psychologic then major sexual behaviour is social behaviour. We have the saples collection cross sectionally sampling from some girls in Padang with the purpose to know presence bacterial, Neisseriae gonorrhoeae. The descriptive study using direct microscopical Gram stain.ARTIKEL PENELITIAN136Of 18 samples, found patient infected by bacterial N.gonorrhoeae 11 (61% and 7 (38.9%. From the variables tested, the child as bacterial infected are 4 have age 1-3 years (22.22%; 6.4 -7 years (33.3%; 1.8-11 years (5.5% and 0.12-15 years (0% respectively where observed the educational age rates are pre school and school. The children parent that mother and father education are 0 SD (0%; 0 SLP (0%; 14 SLA (77.8% and 4 PT (22.2% and 10 (55.5% respectively (tables 2 and 3. Subsequent the parent jobs include 9 household (50%, 8 PNS/private (44.4% and 14 (77.8%; Trading 1(5.6% and 2 (11.1% Conclude that girls in Padang have been infected by bacteries Neisseriae gonorrhoeae are high.Keywords: gonorrhoea, infected girls, antibiotics resistance.

  18. Antimicrobial blue light inactivation of Neisseria gonorrhoeae

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    Wang, Ying; Gu, Ying; Dai, Tianhong

    2018-02-01

    Neisseria gonorrhoeae is a human-adapted, gram-negative diplococcus that infects human reproductive tracts and causes gonorrhea, a sexually transmitted disease, resulting in discharge and inflammation at the urethra, cervix, pharynx, or rectum. Over the years, N. gonorrhoeae has developed resistance to nearly every drug ever used to treat it, including sulfonamides, penicillin, tetracycline, and fluoroquinolones. Drug-resistant N. gonorrhoeae is now considered by the Centers for Disease Control and Prevention (CDC) as an urgent threat. The present study aimed to evaluate the efficacy of antimicrobial blue light (aBL) at 405 and 470 nm for inactivating N. gonorrhoeae and reveal the mechanism of action. Our results showed that an exposure of 45 J/cm2 aBL at 405 nm reduced the bacterial CFU by 7.16-log10. When the aBL exposure was increased to 54 J/cm2, eradication of bacterial CFU was achieved. When the bacteria were exposed to aBL at 470 nm, 3-log10 reduction of CFU was observed at an aBL exposure of higher than 126 J/cm2. Absorption and fluorescence spectroscopic analyses revealed the presence of endogenous porphyrins and flavins in N. gonorrhoeae cells. The present study indicated that aBL is a potential strategy to control N. gonorrhoeae infections. Endogenous porphyrins play a vital role in the killing effects of aBL. In vivo experiments are ongoing in our laboratory to treat genital tract infections in mice using aBL and explore the potential clinical applications.

  19. Antimicrobial susceptibility pattern of Neisseria gonorrhoeae ...

    African Journals Online (AJOL)

    chronic pelvic pain, infertility, acute urethritis, cervicitis and proctitis or pharyngitis [5]. N. gonorrhoeae infections represent 106 million of the estimated 498 million new cases of curable sexually transmitted infection that occur globally every year [5]. Previous studies have estimated. 3.4 million cases of gonorrhea among ...

  20. Molecular detection of Chlamydia trachomatis and Neisseria gonorrhoeae

    DEFF Research Database (Denmark)

    Møller, Jens Kjølseth; Herrmann, B; Jensen, K.T.

    2011-01-01

    This chapter highlights the use of nucleic acid amplification tests (NAATs) for the molecular diagnosis of gonorrhoea and chlamydia infection. In addition, good laboratory practice and issues that should be considered before and after implementation of NAATs for C. trachomatis and N. gonorrhoeae...

  1. Type I Interferon Induction by Neisseria gonorrhoeae: Dual Requirement of Cyclic GMP-AMP Synthase and Toll-like Receptor 4.

    Science.gov (United States)

    Andrade, Warrison A; Agarwal, Sarika; Mo, Shunyan; Shaffer, Scott A; Dillard, Joseph P; Schmidt, Tobias; Hornung, Veit; Fitzgerald, Katherine A; Kurt-Jones, Evelyn A; Golenbock, Douglas T

    2016-06-14

    The innate immune system is the first line of defense against Neisseria gonorrhoeae (GC). Exposure of cells to GC lipooligosaccharides induces a strong immune response, leading to type I interferon (IFN) production via TLR4/MD-2. In addition to living freely in the extracellular space, GC can invade the cytoplasm to evade detection and elimination. Double-stranded DNA introduced into the cytosol binds and activates the enzyme cyclic-GMP-AMP synthase (cGAS), which produces 2'3'-cGAMP and triggers STING/TBK-1/IRF3 activation, resulting in type I IFN expression. Here, we reveal a cytosolic response to GC DNA that also contributes to type I IFN induction. We demonstrate that complete IFN-β induction by live GC depends on both cGAS and TLR4. Type I IFN is detrimental to the host, and dysregulation of iron homeostasis genes may explain lower bacteria survival in cGAS(-/-) and TLR4(-/-) cells. Collectively, these observations reveal cooperation between TLRs and cGAS in immunity to GC infection. Copyright © 2016. Published by Elsevier Inc.

  2. Type I Interferon Induction by Neisseria gonorrhoeae: Dual Requirement of Cyclic GMP-AMP Synthase and Toll-like Receptor 4

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    Warrison A. Andrade

    2016-06-01

    Full Text Available The innate immune system is the first line of defense against Neisseria gonorrhoeae (GC. Exposure of cells to GC lipooligosaccharides induces a strong immune response, leading to type I interferon (IFN production via TLR4/MD-2. In addition to living freely in the extracellular space, GC can invade the cytoplasm to evade detection and elimination. Double-stranded DNA introduced into the cytosol binds and activates the enzyme cyclic-GMP-AMP synthase (cGAS, which produces 2′3′-cGAMP and triggers STING/TBK-1/IRF3 activation, resulting in type I IFN expression. Here, we reveal a cytosolic response to GC DNA that also contributes to type I IFN induction. We demonstrate that complete IFN-β induction by live GC depends on both cGAS and TLR4. Type I IFN is detrimental to the host, and dysregulation of iron homeostasis genes may explain lower bacteria survival in cGAS−/− and TLR4−/− cells. Collectively, these observations reveal cooperation between TLRs and cGAS in immunity to GC infection.

  3. Characterization of the structure and immunostimulatory activity of a vaccine adjuvant, de-O-acylated lipooligosaccharide.

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    Ji Eun Han

    Full Text Available Lipopolysaccharide (LPS is a major component of the outer membrane of Gram-negative bacteria. LPS elicits strong immunopathological responses during bacterial infection, and the lipid A moiety of LPS is responsible for this immunostimulatory activity. Lipid A exerts its biological activity by sending signals via TLR4 present on immune cells, and TLR4 agonists have been a target for vaccine adjuvant. Previously, we demonstrated an adjuvant activity of deacylated lipooligosaccharide (dLOS to viral and bacterial antigens. In this study, we characterized the chemical structure of dLOS and evaluated its immunostimulatory activity on mouse and human immune cells in comparison with monophosphoryl lipid A (MPL. dLOS consists of the R3-type core, a glucosamine disaccharide with two phosphate groups, and two N-linked acyl groups [corrected], and two N-linked acyl groups. dLOS was similar to MPL in induction of cytokine production in mouse peritoneal macrophages, but was a more potent activator in human monocytes and dendritic cells (DCs. Results of an analysis of allogeneic T cell responses revealed that dLOS induces Th1, Th2, and Th17-type immune responses in a dose-dependent manner. The immunostimulatory activities of dLOS were completely abrogated in TLR4(-/- mice, which confirms its TLR4-dependency. These results suggest that in the presence of the core oligosaccharide, O-linked acyl groups of LPS are dispensable for activating the TLR4 signaling pathway. dLOS did not cause any pathological effects or death at 0.25, 0.5, or 1 mg per kg body weight in mice in the acute toxicity tests. This result suggests that dLOS has a low toxicity. dLOS should be considered for further development as a safe and effective adjuvant for human vaccines.

  4. Variation in the OC locus of Acinetobacter baumannii genomes predicts extensive structural diversity in the lipooligosaccharide.

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    Johanna J Kenyon

    Full Text Available Lipooligosaccharide (LOS is a complex surface structure that is linked to many pathogenic properties of Acinetobacter baumannii. In A. baumannii, the genes responsible for the synthesis of the outer core (OC component of the LOS are located between ilvE and aspS. The content of the OC locus is usually variable within a species, and examination of 6 complete and 227 draft A. baumannii genome sequences available in GenBank non-redundant and Whole Genome Shotgun databases revealed nine distinct new types, OCL4-OCL12, in addition to the three known ones. The twelve gene clusters fell into two distinct groups, designated Group A and Group B, based on similarities in the genes present. OCL6 (Group B was unique in that it included genes for the synthesis of L-Rhamnosep. Genetic exchange of the different configurations between strains has occurred as some OC forms were found in several different sequence types (STs. OCL1 (Group A was the most widely distributed being present in 18 STs, and OCL6 was found in 16 STs. Variation within clones was also observed, with more than one OC locus type found in the two globally disseminated clones, GC1 and GC2, that include the majority of multiply antibiotic resistant isolates. OCL1 was the most abundant gene cluster in both GC1 and GC2 genomes but GC1 isolates also carried OCL2, OCL3 or OCL5, and OCL3 was also present in GC2. As replacement of the OC locus in the major global clones indicates the presence of sub-lineages, a PCR typing scheme was developed to rapidly distinguish Group A and Group B types, and to distinguish the specific forms found in GC1 and GC2 isolates.

  5. Activation of murine macrophages by lipoprotein and lipooligosaccharide of Treponema denticola.

    Science.gov (United States)

    Rosen, G; Sela, M N; Naor, R; Halabi, A; Barak, V; Shapira, L

    1999-03-01

    We have recently demonstrated that the periodontopathogenic oral spirochete Treponema denticola possesses membrane-associated lipoproteins in addition to lipooligosaccharide (LOS). The aim of the present study was to test the potential of these oral spirochetal components to induce the production of inflammatory mediators by human macrophages, which in turn may stimulate tissue breakdown as observed in periodontal diseases. An enriched lipoprotein fraction (dLPP) from T. denticola ATCC 35404 obtained upon extraction of the treponemes with Triton X-114 was found to stimulate the production of nitric oxide (NO), tumor necrosis factor alpha (TNF-alpha), and interleukin-1 (IL-1) by mouse macrophages in a dose-dependent manner. Induction of NO by dLPP was at 25% of the levels obtained by Salmonella typhosa lipopolysaccharide (LPS) at similar concentrations, while IL-1 was produced at similar levels by both inducers. dLPP-mediated macrophage activation was unaffected by amounts of polymyxin B that neutralized the induction produced by S. typhosa LPS. dLPP also induced NO and TNF-alpha secretion from macrophages isolated from endotoxin-unresponsive C3H/HeJ mice to an extent similar to the stimulation produced in endotoxin-responsive mice. Purified T. denticola LOS also produced a concentration-dependent activation of NO and TNF-alpha in LPS-responsive and -nonresponsive mouse macrophages. However, macrophage activation by LOS was inhibited by polymyxin B. These results suggest that T. denticola lipoproteins and LOS may play a role in the inflammatory processes that characterize periodontal diseases.

  6. Activation of Murine Macrophages by Lipoprotein and Lipooligosaccharide of Treponema denticola

    Science.gov (United States)

    Rosen, Graciela; Sela, Michael N.; Naor, Ronit; Halabi, Amal; Barak, Vivian; Shapira, Lior

    1999-01-01

    We have recently demonstrated that the periodontopathogenic oral spirochete Treponema denticola possesses membrane-associated lipoproteins in addition to lipooligosaccharide (LOS). The aim of the present study was to test the potential of these oral spirochetal components to induce the production of inflammatory mediators by human macrophages, which in turn may stimulate tissue breakdown as observed in periodontal diseases. An enriched lipoprotein fraction (dLPP) from T. denticola ATCC 35404 obtained upon extraction of the treponemes with Triton X-114 was found to stimulate the production of nitric oxide (NO), tumor necrosis factor alpha (TNF-α), and interleukin-1 (IL-1) by mouse macrophages in a dose-dependent manner. Induction of NO by dLPP was at 25% of the levels obtained by Salmonella typhosa lipopolysaccharide (LPS) at similar concentrations, while IL-1 was produced at similar levels by both inducers. dLPP-mediated macrophage activation was unaffected by amounts of polymyxin B that neutralized the induction produced by S. typhosa LPS. dLPP also induced NO and TNF-α secretion from macrophages isolated from endotoxin-unresponsive C3H/HeJ mice to an extent similar to the stimulation produced in endotoxin-responsive mice. Purified T. denticola LOS also produced a concentration-dependent activation of NO and TNF-α in LPS-responsive and -nonresponsive mouse macrophages. However, macrophage activation by LOS was inhibited by polymyxin B. These results suggest that T. denticola lipoproteins and LOS may play a role in the inflammatory processes that characterize periodontal diseases. PMID:10024558

  7. Sialylation of lipooligosaccharides is dispensable for the virulence of Haemophilus ducreyi in humans.

    Science.gov (United States)

    Spinola, Stanley M; Li, Wei; Fortney, Kate R; Janowicz, Diane M; Zwickl, Beth; Katz, Barry P; Munson, Robert S

    2012-02-01

    Sialylated glycoconjugates on the surfaces of mammalian cells play important roles in intercellular communication and self-recognition. The sialic acid preferentially expressed in human tissues is N-acetylneuraminic acid (Neu5Ac). In a process called molecular mimicry, many bacterial pathogens decorate their cell surface glycolipids with Neu5Ac. Incorporation of Neu5Ac into bacterial glycolipids promotes bacterial interactions with host cell receptors called Siglecs. These interactions affect bacterial adherence, resistance to serum killing and phagocytosis, and innate immune responses. Haemophilus ducreyi, the etiologic agent of chancroid, expresses lipooligosaccharides (LOS) that are highly sialylated. However, an H. ducreyi sialyltransferase (lst) mutant, whose LOS contain reduced levels of Neu5Ac, is fully virulent in human volunteers. Recently, a second sialyltransferase gene (Hd0053) was discovered in H. ducreyi, raising the possibility that Hd0053 compensated for the loss of lst during human infection. CMP-Neu5Ac is the obligate nucleotide sugar donor for all bacterial sialyltransferases; LOS derived from an H. ducreyi CMP-Neu5Ac synthetase (neuA) mutant has no detectable Neu5Ac. Here, we compared an H. ducreyi neuA mutant to its wild-type parent in several models of pathogenesis. In human inoculation experiments, the neuA mutant formed papules and pustules at rates that were no different than those of its parent. When grown in media with and without Neu5Ac supplementation, the neuA mutant and its parent had similar phenotypes in bactericidal, macrophage uptake, and dendritic cell activation assays. Although we cannot preclude a contribution of LOS sialylation to ulcerative disease, these data strongly suggest that sialylation of LOS is dispensable for H. ducreyi pathogenesis in humans.

  8. Molecular characterization of phosphorylcholine expression on the lipooligosaccharide of Histophilus somni

    Science.gov (United States)

    Elswaifi, Shaadi F.; St. Michael, Frank; Sreenivas, Avula; Cox, Andrew; Carman, George M.; Inzana, Thomas J.

    2013-01-01

    Histophilus somni (Haemophilus somnus) is an important pathogen of cattle that is responsible for respiratory disease, septicemia, and systemic diseases such as thrombotic meningoencephalitis, myocarditis, and abortion. A variety of virulence factors have been identified in H. somni, including compositional and antigenic variation of the lipooligosaccharide (LOS). Phosphorylcholine (ChoP) has been identified as one of the components of H. somni LOS that undergoes antigenic variation. In this study, five genes (lic1ABCDHs and glpQ) with homology to genes responsible for ChoP expression in Haemophilus influenzae LOS were identified in the H. somni genome. An H. somni open reading frame (ORF) with homology to H. influenzae lic1A (lic1AHi) contained a variable number of tandem repeats (VNTR). However, whereas the tetranucleotide repeat 5′-CAAT-3′ is present in lic1AHi, the VNTR in H. somni lic1A (lic1AHs) consisted of 5′-AACC-3′. Due to the propensity of VNTR to vary during replication and cause the ORF to shift in and out of frame with the upstream start codon, the VNTR were deleted from lic1AHs to maintain the gene constitutively on. This construct was cloned into Escherichia coli, and functional enzyme assays confirmed that lic1AHs encoded a choline kinase, and that the VNTR were not required for expression of a functional gene product. Variation in the number of VNTR in lic1AHs correlated with antigenic variation of ChoP expression in H. somni strain 124P. However, antigenic variation of ChoP expression in strain 738 predominately occurred through variable extension/truncation of the LOS outer core. These results indicated that the lic1Hs genes controlled expression of ChoP on the LOS, but that in H. somni there are two potential mechanisms that account for antigenic variation of ChoP. PMID:19682567

  9. Antimicrobial susceptibility profile of Neisseria gonorrhoeae at STI clinic

    Directory of Open Access Journals (Sweden)

    Shilpee C

    2008-01-01

    Full Text Available A total of 100 consecutive patients who attended a sexually transmitted infections clinic were studied. Thirteen had gonococcal urethritis, of which 10 showed growth of Neisseria gonorrhoeae on culture. All the isolates were tested for antimicrobial susceptibility by Australian Gonococcal Surveillance Programme (AGSP method and beta lactamase production by chromogenic cephalosporin test. Four patients were co-infected with each of the following: HIV, HBV and Chlamydia trachomatis . Gonococcal urethritis (13% was found more in male patients. Ten percent gonococcal isolates were penicillinase-producing N. gonorrhoeae , and another 10% were tetracycline-resistant N. gonorrhoeae .

  10. Antimicrobial susceptibility pattern of Neisseria gonorrhoeae in western Austria.

    Science.gov (United States)

    Allerberger, F; Kofler, H; Brezinka, C; Guggenbichler, J P; Dierich, M P

    1993-01-01

    From January to October 1992 24 Neisseria gonorrhoeae isolates from clinical specimens were collected at the Federal Public Health Laboratory in Innsbruck (Austria) and screened for resistance to penicillin G, erythromycin, tetracycline, spectinomycin, ceftriaxone, cefuroxime, ciprofloxacine, and silver nitrate. Patients originated from the Austrian provinces Salzburg, Tirol, and Vorarlberg, and presented with manifest gonorrhoea. Two of 24 isolates were penicillinase-producing N. gonorrhoeae. Both strains were isolated from men who had just returned from Thailand or Kenya. The isolate from Africa was also resistant to tetracycline. Five of 24 infections were acquired abroad, sex tourism being involved in four cases. The antimicrobial resistance pattern found in gonococci in western Austria revealed that topical silver nitrate and erythromycin are equally acceptable for use in prophylaxis of neonatal ophthalmia. Penicillin is still the drug of choice in the treatment of endemic infections. If gonorrhoea has been acquired abroad, especially in Asia or Africa, ceftriaxone, spectinomycin or ciprofloxazine are recommended for therapy.

  11. Nucleotide sequence composition and method for detection of neisseria gonorrhoeae

    International Nuclear Information System (INIS)

    Lo, A.; Yang, H.L.

    1990-01-01

    This patent describes a composition of matter that is specific for Neisseria gonorrhoeae. It comprises: at least one nucleotide sequence for which the ratio of the amount of the sequence which hybridizes to chromosomal DNA of Neisseria gonorrhoeae to the amount of the sequence which hybridizes to chromosomal DNA of Neisseria meningitidis is greater than about five. The ratio being obtained by a method described

  12. Nucleotide sequence composition and method for detection of neisseria gonorrhoeae

    Energy Technology Data Exchange (ETDEWEB)

    Lo, A.; Yang, H.L.

    1990-02-13

    This patent describes a composition of matter that is specific for {ital Neisseria gonorrhoeae}. It comprises: at least one nucleotide sequence for which the ratio of the amount of the sequence which hybridizes to chromosomal DNA of {ital Neisseria gonorrhoeae} to the amount of the sequence which hybridizes to chromosomal DNA of {ital Neisseria meningitidis} is greater than about five. The ratio being obtained by a method described.

  13. Characteristics of gonorrhoea in Kermanshah, Iran.

    Science.gov (United States)

    Zargooshi, J

    2002-12-01

    To describe the characteristics of gonorrhoea and prostitution in Kermanshah, Iran. From 1997 through 2000, 100 male gonorrhoea patients were followed for a mean of 18 months (range 8-42 months). Diagnosis and follow up were made by a combination of history, physical examination, and the Gram stained smear. 4% of patients became infected by girlfriends, 24% by temporary (sigheh) wives, and 64% by street prostitutes; the remaining 8% denied coitus with sex workers. Of 38 married cases, 31 reported unprotected intercourse with permanent wives while infected, and only four of 38 gave prescribed drugs to their wives. 89% of contacts with prostitutes were unprotected. Most of the prostitutes and professional sigheh wives were practising survival sex. Fear of stigmatization and presumed severe penalties prevented prostitutes from seeking medical care, and 26% of patrons reported self medication. An average 84% of prescriptions of standard therapies failed. 31% of the cases remained refractory to all available therapies. The majority of the prostitutes and sigheh wives in Iran exchange sex for survival. Being uneducated survival sex workers, they accept risky sex behaviours easily. Sigheh wives are an important source of infection. The very high rate of persistent infection despite standard treatments is disturbing. Our ideal is a world in which nobody is obliged to enter commercial sex work. In the meantime, however, there is an urgent need to offer medical care and education to sex workers as needy patients in a safe and unprejudiced environment. Denying the presence of such realities as prostitution and sexually transmitted diseases (STDs) because of their disagreement with cant claims and official propaganda, does not eradicate the facts but results in catastrophic public health problems.

  14. The role of lipooligosaccharide phosphorylcholine in colonization and pathogenesis of Histophilus somni in cattle

    Directory of Open Access Journals (Sweden)

    Elswaifi Shaadi F

    2012-06-01

    Full Text Available Abstract Histophilus somni is a Gram-negative bacterium and member of the Pasteurellaceae that is responsible for respiratory disease and other systemic infections in cattle. One of the bacterium’s virulence factors is antigenic phase variation of its lipooligosaccharide (LOS. LOS antigenic variation may occur through variation in composition or structure of glycoses or their substitutions, such as phosphorylcholine (ChoP. However, the role of ChoP in the pathogenesis of H. somni disease has not been established. In Haemophilus influenzae ChoP on the LOS binds to platelet activating factor on epithelial cells, promoting bacterial colonization of the host upper respiratory tract. However, ChoP is not expressed in the blood as it also binds C-reactive protein, resulting in complement activation and killing of the bacteria. In order to simulate the susceptibility of calves with suppressed immunity due to stress or previous infection, calves were challenged with bovine herpes virus-1 or dexamethazone 3 days prior to challenge with H. somni. Following challenge, expression of ChoP on the LOS of 2 different H. somni strains was associated with colonization of the upper respiratory tract. In contrast, lack of ChoP expression was associated with bacteria recovered from systemic sites. Histopathology of cardiac tissue from myocarditis revealed lesions containing bacterial clusters that appeared similar to a biofilm. Furthermore, some respiratory cultures contained substantial numbers of Pasteurella multocida, which were not present on preculture screens. Subsequent biofilm experiments have shown that H. somni and P. multocida grow equally well together in a biofilm, suggesting a commensal relationship may exist between the two species. Our results also showed that ChoP contributed to, but was not required for, adhesion to respiratory epithelial cells. In conclusion, expression of ChoP on H. somni LOS contributed to colonization of the bacteria to the

  15. Antibiotics for treating gonorrhoea in pregnancy.

    Science.gov (United States)

    Comunián-Carrasco, Gabriella; Peña-Martí, Guiomar E; Martí-Carvajal, Arturo J

    2018-02-21

    Gonorrhoea is a sexually transmitted infection that is caused by Neisseria gonorrhoeae, and is a major public health challenge today. N gonorrhoeae can be transmitted from the mother's genital tract to the newborn during birth, and can cause gonococcal ophthalmia neonatorum as well as systemic neonatal infections. It can also cause endometritis and pelvic sepsis in the mother. This review updates and replaces an earlier Cochrane Review on antibiotics for treating this infectious condition. To assess the clinical effectiveness and harms of antibiotics for treating gonorrhoea in pregnant women. We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (31 May 2017), LILACS database (1982 to April 5, 2017), the WHO International Clinical Trials Registry Platform (ICTRP; April 5, 2017), ClinicalTrials.gov (April 5, 2017), the ISRCTN Registry (April 5, 2017), and Epistemonikos (April 5, 2017). We also searched reference lists of all retrieved articles. We included randomised controlled trials (RCTs) comparing the use of antibiotics for treating gonorrhoea in pregnancy. The antibiotics could have been used alone or in combination, were administered parenterally, orally, or both, and were compared with another antibiotic.We included RCTs regardless of their publication status (published, unpublished, published as an article, an abstract, or a letter), language, or country. We applied no limits on the length of follow-up.We excluded RCTs using a cluster- or cross-over design, or quasi-RCTs. Three review authors independently assessed trials for inclusion and risk of bias, extracted data, and checked them for accuracy. We included two RCTs, that randomised 514 pregnant women (347 women analysed) at a mean gestational age of 22 weeks. Both trials were conducted in the outpatient department of the same two hospitals in the USA between 1993 and 2001, and had a follow-up of 14 days. One of the trials was sponsored by a drug company. We considered both trials to

  16. Distinct Neisseria gonorrhoeae Transmission Networks Among Men Who Have Sex With Men in Amsterdam, the Netherlands

    NARCIS (Netherlands)

    Heymans, Raymond; A Matser, Amy; Bruisten, Sylvia M.; Heijman, Titia; Geskus, Ronald B.; Speksnijder, Adrianus G. C. L.; Davidovich, Udi; de Vries, Henry J. C.; Coutinho, Roel A.; Schim van der Loeff, Maarten F.

    2012-01-01

    Background. Molecular typing was used to elucidate Neisseria gonorrhoeae transmission networks among men who have sex with men (MSM) in Amsterdam, the Netherlands. We determined whether clusters of patients infected with specific N. gonorrhoeae genotypes were related to various epidemiological

  17. Design of a multiplex PCR assay for the simultaneous detection and confirmation of Neisseria gonorrhoeae.

    LENUS (Irish Health Repository)

    O'Callaghan, Isabelle

    2010-05-01

    To improve the detection of Neisseria gonorrhoeae by designing a multiplex PCR assay using two N gonorrhoeae-specific genes as targets, thereby providing detection and confirmation of a positive result simultaneously.

  18. Diagnosis of Neisseria gonorrhoeae Using Molecular Beacon

    Science.gov (United States)

    Patel, Achchhe Lal; Sonkar, Subash Chandra; Kumari, Indu; Saluja, Daman

    2015-01-01

    Neisseria gonorrhoeae is an important sexually transmitted diseases (STD) causing pathogen worldwide. Due to absence of an affordable diagnostic assay, routine screening of gonococcal infection becomes impossible in developing countries where infection rates are maximum. Treatment is given on the basis of symptoms alone which leads to spread of infection. Thus, development of a rapid, sensitive, specific, and PCR based visual diagnostic assay suitable for developing countries, required for better disease management, is aimed at in present study. Endocervical swabs were collected from patients visiting gynecology department of various hospitals in Delhi. In-house PCR based assay was developed and modified to visual assay using molecular beacon for end-point detection. It was evaluated against Roche AMPLICOR NG kit and rmp gene. Specificity of beacon was confirmed by competition experiments. Diagnostic test was 98.21% specific and 99.59% sensitive whereas negative and positive predicted value were 99.40% and 98.78%, respectively. We also observed that twice the concentration (2X) of premix was stable at 4°C for 4 months and dry swab samples gave concordant results with that of wet swabs. These features make the test best suitable for routine diagnosis of genital infections in developing countries. PMID:25802857

  19. INFEKSI NEISSERIA GONORRHOEAE AKIBAT SEXUAL ABUSE PADA SEORANG ANAK PEREMPUAN

    Directory of Open Access Journals (Sweden)

    Satya Wydya Yenny

    2008-09-01

    Full Text Available AbstrakInfeksi Neisseria gonorrhoeae pada anak akibat sexual abuse sangat jarang dilaporkan.Dilaporkan satu kasus infeksi Neisseria gonorrhoeae pada seorang anak perempuan usia 6 tahun setelah mengalami sexual abuse satu minggu yang lalu.Diagnosis ditegakkan berdasarkan anamnesis, pemeriksaan klinis dan pemeriksaan laboratorium. Anamnesis adanya keputihan sejak 5 hari sebelum berobat. Pada pemeriksaan fisis tampak cairan berwarna krem menempel pada celana dalam, cukup banyak, serta sedikit kemerahan dan duh genital pada vulva. Hasil pemeriksaan mikroskopis ditemukan diplokokus Gram negatif dan kultur didapatkan Neisseria gonorrhoeae. Berdasarkan hasil tes sensitivitas, pasien diterapi dengan ceftriaxon 125 mg i.m, dosis tunggal dan memberikan kesembuhan.Infeksi ini membutuhkan penatalaksanaan yang komprehensif karena mempunyai dampak psikologis baik bagi anak maupun keluarga seumur hidupKata kunci : Neisseria gonorrhoeae, sexual abuse, anakAbstractNeisseria gonorrhoe infection in childhood caused by sexual abuse is considered rare reported.A young girl 6 years old suffering gonococcal infection was reported. The diagnostic procedure were base on clinically and laboratory findings. The source of transmission was sexual abuse by an adult man. Physical examination revealed purulent discharge, cream in colour that stains the underwear with minimal vaginal discharge and vulval erythema. Laboratory examination showed Gram-negative diplococcic and isolation of Neisseria gonorrhoeae. This patient had been treated with ceftriaxon 125mg given intramuscularly in a single dose. Result of the treatment was good.The psychological sequelae of sexual abuse and the turmoil in the family produced by suspicions and allegations are largely unknown, but are probably life long.Keywords: Neisseria gonorrhoeae, sexual abuse, childLAPORAN

  20. Agar dilution method for susceptibility testing of Neisseria gonorrhoeae

    Directory of Open Access Journals (Sweden)

    Marta C de Castillo

    1996-12-01

    Full Text Available The antibiotic susceptibilities of Neisseria gonorrhoeae isolates obtained from patients attending a clinic for sexually transmitted diseases in Tucumán, Argentina, were determined by the agar dilution method (MIC. 3.5% of the isolates produced ²-lactamase. A total of 96.5% of ²-lactamase negative isolates tested were susceptible to penicillin (MIC < 2 µgml-1; 14.03% of the tested isolates were resistant to tetracycline (MIC < 2 µgml-1, and 98% of the tested isolates were susceptible to spectinomycin (MIC < 64 µgml-1. The MICs for 95% of the isolates, tested for other drugs were: < 2 µgml-1 for cefoxitin, < 0.06 µgml-1 for cefotaxime, < 0.25 µgml-1 for norfloxacin, < 10 µgml-1 for cephaloridine, < 10 µgml-1 for cephalexin, and < 50 µgml-1 for kanamycin. Antibiotic resistance among N. gonorrhoeae isolates from Tucumán, Argentina, appeared to be primarily limited to penicillin and tetracycline, which has been a general use against gonorrhoeae in Tucumán since 1960. Periodic monitoring of the underlying susceptibility profiles of the N. gonorrhoeae strains prevalent in areas of frequent transmission may provide clues regarding treatment options and emerging of drug resistance.

  1. Comparison of COBAS AMPLICOR Neissefia gonorrhoeae PCR, including confirmation with N-gonorrhoeae-specific 16S rRNA PCR, with traditional culture

    NARCIS (Netherlands)

    Luijt, DS; Bos, PAJ; van Zwet, AA; Vader, PCV; Schirm, J

    A total of 3,023 clinical specimens were tested for Neisseria gonorrhoeae by using COBAS AMPLICOR (CA) PCR and confirmation of positives by N. gonorrhoeae-specific 16S rRNA PCR. The sensitivity of CA plus 16S rRNA PCR was 98.8%, compared to 68.2% for culture. Confirmation of CA positives increased

  2. Structural Investigation of the Oligosaccharide Portion Isolated from the Lipooligosaccharide of the Permafrost Psychrophile Psychrobacter arcticus 273-4.

    Science.gov (United States)

    Casillo, Angela; Parrilli, Ermenegilda; Filomena, Sannino; Lindner, Buko; Lanzetta, Rosa; Parrilli, Michelangelo; Tutino, Maria Luisa; Corsaro, Maria Michela

    2015-07-22

    Psychrophilic microorganisms have successfully colonized all permanently cold environments from the deep sea to mountain and polar regions. The ability of an organism to survive and grow in cryoenviroments depends on a number of adaptive strategies aimed at maintaining vital cellular functions at subzero temperatures, which include the structural modifications of the membrane. To understand the role of the membrane in the adaptation, it is necessary to characterize the cell-wall components, such as the lipopolysaccharides, that represent the major constituent of the outer membrane. The aim of this study was to investigate the structure of the carbohydrate backbone of the lipooligosaccharide (LOS) isolated from the cold-adapted Psychrobacter arcticus 273-4. The strain, isolated from a 20,000-to-30,000-year-old continuously frozen permafrost in Siberia, was cultivated at 4 °C. The LOS was isolated from dry cells and analyzed by means of chemical methods. In particular, it was degraded either by mild acid hydrolysis or by hydrazinolysis and investigated in detail by (1)H and (13)C NMR spectroscopy and by ESI FT-ICR mass spectrometry. The oligosaccharide was characterized by the substitution of the heptose residue, usually linked to Kdo in the inner core, with a glucose, and for the unusual presence of N-acetylmuramic acid.

  3. [A case of bacterial peritonitis caused by Neisseria gonorrhoeae].

    Science.gov (United States)

    Akahane, T; Kawakami, Y; Oana, K

    2001-10-01

    On January 17, 2001, a 39-year old female with sudden abdominal pain was admitted to her neighboring outpatient clinic and diagnosed as suspicious of infectious enteritis. However, on the next day (January 18, 2001) she was soon transferred to Toyoshina Red Cross Hospital with the chief complaint of severe abdominal pain, high fever, and of conspicuous leucocytosis. Laboratory data on her admission demonstrated apparent signs of inflammation and she was soon undergone an emergency operation. Neisseria gonorrhoeae was recovered from her ascetic fluid, otherwise Chlamydia EIA was negative. The antibiotic chemotherapy of minocycline (200 mg/day) was continued for the first 9 days and sulbactam/cefoperazone (2 g/day) had been administered for the first 5 days. Her symptoms were discontinued on her 10th hospital day, and she was discharged on the 14th hospital day. There have been few reported cases in Japan of bacterial peritonitis due to N. gonorrhoeae. This is, to the best of our knowledge, the first reported case of N. gonorrhoeae peritonitis in Japan.

  4. Antimicrobial resistance in Neisseria gonorrhoeae in China: a meta-analysis.

    Science.gov (United States)

    Chen, Yawen; Gong, Yanhong; Yang, Tingting; Song, Xingyue; Li, Jing; Gan, Yong; Yin, Xiaoxv; Lu, Zuxun

    2016-03-03

    Neisseria gonorrhoeae (N. gonorrhoeae) resistance to antimicrobial has been a major concern in China, and epidemiological data on N. gonorrhoeae resistance are not well understood. This meta-analysis was aimed at summarizing the evidence on N. gonorrhoeae resistance to penicillin, tetracycline, ciprofloxacin, ceftriaxone and spectinomycin in China. Two researchers independently searched five databases to identify studies on N. gonorrhoeae resistance to antimicrobials from the databases' inception to November 7, 2014. A random-effects model was used to estimate the antimicrobial resistance rates and their corresponding 95% confidence intervals (CIs). Publication bias was assessed with the Begg rank correlation test and the Egger test. We included 127 studies in our synthesis reporting antimicrobial resistance. Our analyses demonstrated that N. gonorrhoeae resistance to penicillin and tetracycline respectively increased from 74.41% (95% CI: 64.1-84.7%) and 68.3% (95% CI: 58.7-78.0%) in 2000 to 84.2% (95% CI: 79.7-88.8%) and 82.4% (95% CI: 79.9-84.7%) in 2012. N. gonorrhoeae resistance to ciprofloxacin experienced a steady increase from 12.7% (95% CI, 8.6-16.7%) in 1995 and reached 93.8% (95% CI: 91.9-95.7%) in 2003. N. gonorrhoeae resistance to ceftriaxone was 1.7% (95% CI: 0.5-5.7%) before 1995 and 0.5% (95% CI: 0.2-1.4%) in 2012, and N. gonorrhoeae resistance to spectinomycin was less than 2% from 1995 to 2012. N. gonorrhoeae resistance rates to penicillin, tetracycline and ciprofloxacin were high in China. Ceftriaxone and spectinomycin remained effective therapy for the treatment of gonorrhea. It is essential to strengthen N. gonorrhoeae resistance surveillance and update treatment guidelines timely.

  5. Secreted single‐stranded DNA is involved in the initial phase of biofilm formation by Neisseria gonorrhoeae

    DEFF Research Database (Denmark)

    Zweig, Maria; Schork, Sabine; Koerdt, Andrea

    2014-01-01

    plays an important role in biofilm formation. Many clinical isolates contain a gonococcal genetic island that encodes a type IV secretion system (T4SS). The T4SS of N. gonorrhoeae strain MS11 secretes ssDNA directly into the medium. Biofilm formation, studied in continuous flow‐chamber systems...... was developed in which thermostable fluorescently labelled ssDNA‐ and ss/dsDNA‐binding proteins were used to visualize ssDNA and total DNA in biofilms and planktonic cultures. Remarkably, mainly dsDNA was detected in biofilms of the ssDNA secreting strain. We conclude that the secreted ssDNA facilitates initial...

  6. Identification of Novel Immunogenic Proteins of Neisseria gonorrhoeae by Phage Display.

    Directory of Open Access Journals (Sweden)

    Daniel O Connor

    Full Text Available Neisseria gonorrhoeae is one of the most prevalent sexually transmitted diseases worldwide with more than 100 million new infections per year. A lack of intense research over the last decades and increasing resistances to the recommended antibiotics call for a better understanding of gonococcal infection, fast diagnostics and therapeutic measures against N. gonorrhoeae. Therefore, the aim of this work was to identify novel immunogenic proteins as a first step to advance those unresolved problems. For the identification of immunogenic proteins, pHORF oligopeptide phage display libraries of the entire N. gonorrhoeae genome were constructed. Several immunogenic oligopeptides were identified using polyclonal rabbit antibodies against N. gonorrhoeae. Corresponding full-length proteins of the identified oligopeptides were expressed and their immunogenic character was verified by ELISA. The immunogenic character of six proteins was identified for the first time. Additional 13 proteins were verified as immunogenic proteins in N. gonorrhoeae.

  7. Increased incidence of gonorrhoea and chlamydia in Greenland 1990-2012

    DEFF Research Database (Denmark)

    Johansen, Mila Broby; Koch, Anders; Wohlfahrt, Jan

    2017-01-01

    BACKGROUND: Since the 1970s, Greenland has presented the highest reported incidence rates of the sexually transmitted infections (STIs) gonorrhoea and chlamydia in the Arctic regions. OBJECTIVE: This study aims to describe sex- and age-specific incidence rates of gonorrhoea and chlamydia from 1990...... to 2012 in Greenland, and to evaluate if changes in case definitions, diagnostic procedures and implementation of STI interventions during the period coincide with rate changes. DESIGN: Gonorrhoea and chlamydia cases were identified from the national STI surveillance. For 1990-2008, STI cases were...... to sex, age and calendar period. RESULTS: Gonorrhoea and chlamydia incidence rates have increased since 1995 to reach 2,555 per 100,000 person-years (PY) for gonorrhoea and 6,403 per 100,000 PY for chlamydia in 2012. From 2006 to 2012, the incidence rates among young adults aged 15-19 years were 8...

  8. Pili-Induced Clustering of N. gonorrhoeae Bacteria.

    Directory of Open Access Journals (Sweden)

    Johannes Taktikos

    Full Text Available Type IV pili (Tfp are prokaryotic retractable appendages known to mediate surface attachment, motility, and subsequent clustering of cells. Tfp are the main means of motility for Neisseria gonorrhoeae, the causative agent of gonorrhea. Tfp are also involved in formation of the microcolonies, which play a crucial role in the progression of the disease. While motility of individual cells is relatively well understood, little is known about the dynamics of N. gonorrhoeae aggregation. We investigate how individual N. gonorrhoeae cells, initially uniformly dispersed on flat plastic or glass surfaces, agglomerate into spherical microcolonies within hours. We quantify the clustering process by measuring the area fraction covered by the cells, number of cell aggregates, and their average size as a function of time. We observe that the microcolonies are also able to move but their mobility rapidly vanishes as the size of the colony increases. After a certain critical size they become immobile. We propose a simple theoretical model which assumes a pili-pili interaction of cells as the main clustering mechanism. Numerical simulations of the model quantitatively reproduce the experimental data on clustering and thus suggest that the agglomeration process can be entirely explained by the Tfp-mediated interactions. In agreement with this hypothesis mutants lacking pili are not able to form colonies. Moreover, cells with deficient quorum sensing mechanism show similar aggregation as the wild-type bacteria. Therefore, our results demonstrate that pili provide an essential mechanism for colony formation, while additional chemical cues, for example quorum sensing, might be of secondary importance.

  9. Genetic transformation of Neisseria gonorrhoeae shows a strand preference

    OpenAIRE

    Duffin, Paul M.; Seifert, H. Steven

    2012-01-01

    Natural transformation is the main means of horizontal genetic exchange in the obligate human pathogen Neisseria gonorrhoeae. Neisseria spp. have been shown to preferentially take up and transform their own DNA by recognizing a non-palindromic 10 or 12 nucleotide DNA uptake sequence (DUS10 or DUS12). We investigated the ability of the DUS12 to enhance single-stranded DNA (ssDNA) transformation. Given the non-palindromic nature of the DUS12, we tested whether both strands of the DUS equally en...

  10. Neisseria gonorrhoeae DNA bacterial load in men with symptomatic and asymptomatic gonococcal urethritis.

    Science.gov (United States)

    Priest, David; Ong, Jason J; Chow, Eric P F; Tabrizi, Sepehr; Phillips, Sam; Bissessor, Melanie; Fairley, Christopher K; Bradshaw, Catriona S; Read, Tim R H; Garland, Suzanne; Chen, Marcus

    2017-11-01

    Previous studies have quantified bacterial loads of Neisseria gonorrhoeae in the pharynx and rectum of men but not the urethra. We quantified the bacterial load of N. gonorrhoeae in men with symptomatic and asymptomatic urethral gonorrhoea infections. Consecutive men diagnosed with urethral gonorrhoea by Aptima Combo 2 testing of urine at the Melbourne Sexual Health Centre between March and July 2016 were eligible for the study: symptomatic men with purulent urethral discharge and asymptomatic men with no urethral symptoms. The gonococcal bacterial load in both groups was measured by urethral swab using a standardised collection method and real-time quantitative PCR targeting the opa gene. Twenty men were recruited into the study: 16 had purulent urethral discharge and 4 had asymptomatic urethral gonorrhoea. The median gonococcal bacterial load was significantly higher among symptomatic men (3.7×10 6 copies per swab, IQR 2.5×10 6 -4.7×10 6 ) compared with asymptomatic men (2.0×10 5 copies per swab, IQR 2.7×10 4 -4.5×10 5 ) (p=0.002). Gonococcal loads in men with urethral discharge were higher than loads seen with asymptomatic urethral gonorrhoea and loads seen in asymptomatic pharyngeal and rectal gonorrhoea infections in previous studies. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

  11. Prevalent serogroups and antibiotic sensitivity of Neisseria gonorrhoeae

    Directory of Open Access Journals (Sweden)

    Aggarwal S

    1992-01-01

    Full Text Available One hundred and thirty two cases clinically labeled as acute gonorrhoea were investigated for gonococcal etiology. Smears were positive in 110 (83.3% cases and among these N. gonorrhoeae could be identified in 102 (77.3% cases by culture method. Strains were examined for serogrouping by monoclonal GC test which utilizes the principle of co-agglutination and detects the antigens of outer membrane protein. 96(94.1% strains belonged to serogroup W II/III, showing it to be the major serogroup circulating in the community. The strains were tested for sensitivity against 7 antibiotics. The largest proportion (30.4% of strains were resistant to penicillin (MIC>O. 125 IU/ml. Resistance to cotrimoxazole, erythromycin, cephalaxin and tetracycline was noted as 18.6, 17.6, 7.8 and 5.8 percent respectively. Strains showing resistance concurrently to two or more drugs were observed. All restrains were sensitive to gentamicin and norfloxacin. None of the strains was penicillinase producer.

  12. Molecular characterization of two high-level ceftriaxone-resistant Neisseria gonorrhoeae isolates detected in Catalonia, Spain.

    Science.gov (United States)

    Cámara, Jordi; Serra, Judit; Ayats, Josefina; Bastida, Teresa; Carnicer-Pont, Dolors; Andreu, Antònia; Ardanuy, Carmen

    2012-08-01

    The aim of this study was to characterize the first two extended-spectrum cephalosporin-resistant and multidrug-resistant (MDR) Neisseria gonorrhoeae isolates collected from two sexually related patients (men who have sex with men) in Spain. Antimicrobial susceptibility was studied by Etest. Genes involved in quinolone, ceftriaxone and multidrug resistance were amplified by PCR and sequenced in both directions. The isolates were typed by N. gonorrhoeae multi-antigen sequence typing (NG-MAST). The two isolates had the same MDR profile, showing resistance to penicillin (MIC 0.094 mg/L; β-lactamase negative), ceftriaxone (MIC 1.5 mg/L), cefixime (MIC 1.5 mg/L), cefotaxime (MIC 1 mg/L), ciprofloxacin (MIC >32 mg/L) and tetracycline (MIC 1.5 mg/L). NG-MAST showed that both isolates belonged to sequence type (ST) 1407 (porB-908 and tbpB-110). Ciprofloxacin resistance was due to amino acid substitutions in GyrA (S91F and D95G) and ParC (S87R). An A deletion in the promoter of the MtrCDE efflux pump (mtrR) was detected. No changes were detected in the pilQ gene. The outer membrane protein PorB showed two substitutions at G120K and A121N. An L421P substitution was observed in the PBP1A (ponA) sequence. The sequence of PBP2 (penA) showed a mosaic structure related to genotype XXXIV with a single additional amino acid substitution (A501P). This genotype was identical to a recently described French isolate (F89). This is the first reported case of high-level extended-spectrum cephalosporin-resistant N. gonorrhoeae transmission. The molecular typing and MDR genotype suggest possible European spread of this strain, highlighting the need for surveillance and the importance of testing the susceptibility of N. gonorrhoeae to extended-spectrum cephalosporins.

  13. Trehalose-containing lipooligosaccharides of Mycobacterium gordonae: presence of a mono-O-methyltetra-O-acyltrehalose "core" and branching in the oligosaccharide backbone.

    Science.gov (United States)

    Besra, G S; McNeil, M R; Khoo, K H; Dell, A; Morris, H R; Brennan, P J

    1993-11-30

    Past evidence has indicated that Mycobacterium gordonae, as isolated from soil and as an occasional opportunistic pathogen, exists as a serocomplex. We now demonstrate that the basis of seroreactivity and diversity is a novel series of alkali-labile, trehalose-containing lipooligosaccharides (LOS). The structures from two strains were established by per-O-methylation, partial acid hydrolysis, infrared and high-field NMR spectroscopy, electron-impact MS, and fast atom bombardment/mass spectrometry of the native lipooligosaccharides and hydrolysis products. The structure of the major lipooligosaccharide, LOS-I, of M. gordonae strain 989 was defined as 2-O-CH3-4-O-CH3CO-alpha-L-Fucp-(1-->3)- beta-D-Glcp-(1-->3)-2-O-CH3-alpha-L-Rhap-(1-->3)-[beta-D-Xylp++ +-(1-->2)-]- alpha-L-Rhap-(1-->3)-beta-D-Glcp-(1-->3)-alpha-L-Rhap-(1-->3 )-6-O- CH3-alpha-D-Glcp-(11)-2,3,4,6-tetra-O-acyl-alpha-D-Glcp, which was further glycosylated at C-3 of the terminal 2-O-CH3-4-O-CH3CO-alpha-L-Fucp by an incompletely defined N-acyl derivative of 4-amino-4,6-dideoxy-2,3-di-O-CH3-Galp. The structure of the major lipooligosaccharide, LOS-I, of a second strain of M. gordonae (strain 990) was defined as alpha-L-Rhap-(1-->2)-3-O-CH3-alpha-L-Rhap- (1-->3)-[beta-D-Xylp-(1-->2)-]-alpha-L-Rhap-(1-->3)-beta-D-G lcp- (1-->3)[beta-D-Xylp-(1-->2)-]-alpha-L-Rhap- (1-->3)-beta-D-Glcp-(1-->3)-beta-D-Glcp-(1-->3)-alpha-L-Rhap-(1--> 3)-6-O-CH3- alpha-D-Glcp-(11)-2,3,4,6-tetra-O-acyl-alpha-D-Glcp. The other minor LOSs from both strains were also defined. Both families of LOSs from the two strains contain a novel mono-6'-O-CH3-2,3,4,6-tetra-O-acyltrehalose unit, representing the first example of such a unit among the LOSs isolated to date from mycobacteria. Also, the more polar antigenic products, LOS-I, -II', -II", and -III from M. gordonae 989 and LOS-I, -II, and -II' from M. gordonae 990, are characterized by branching of the oligosaccharide backbone, the first instance of sugar branching in these products. In

  14. Neisseria gonorrhoeae: testing, typing and treatment in an era of increased antimicrobial resistance

    NARCIS (Netherlands)

    Wind, C.M.

    2017-01-01

    This thesis discusses the management of Neisseria gonorrhoeae infections while under threat of emerging antimicrobial resistance. It focuses on improved diagnostics, and antimicrobial resistance to current and future therapies. We describe a new method of targeted deferred culture, using nucleic

  15. Rapid change in the ciprofloxacin resistance pattern among Neisseria gonorrhoeae strains in Nuuk, Greenland

    DEFF Research Database (Denmark)

    Skjerbæk Rolskov, Anne; Bjorn-Mortensen, Karen; Mulvad, Gert

    2015-01-01

    OBJECTIVES: Sexually transmitted infections (STIs), including infections with Neisseria gonorrhoeae (GC), are highly incident in Greenland. Since January 2011, GC testing has been performed on urine with nucleic acid amplification tests (NAATs) by strand displacement amplification (Becton Dickins...

  16. Antiseptic mouthwash against pharyngeal Neisseria gonorrhoeae: a randomised controlled trial and an in vitro study.

    Science.gov (United States)

    Chow, Eric Pf; Howden, Benjamin P; Walker, Sandra; Lee, David; Bradshaw, Catriona S; Chen, Marcus Y; Snow, Anthony; Cook, Stuart; Fehler, Glenda; Fairley, Christopher K

    2017-03-01

    Gonorrhoea is increasing among men who have sex with men (MSM). We aimed to determine whether Listerine, a commercial mouthwash product, has an inhibitory effect against Neisseria gonorrhoeae in a randomised controlled trial (RCT) and an in vitro study, and therefore may be a potentially useful agent for gonorrhoea control. In vitro: a suspension of ∼10 8 colony forming units per mL (CFU/mL) of N. gonorrhoeae was added to a serial of dilutions (up to 1:32) of alcohol-containing Listerine mouthwashes (Cool Mint and Total Care) for 1 min. A 10 µL aliquot was spread over the surface of a gonococcal agar plate and the number of N. gonorrhoeae colonies present at each dilution was calculated. The phosphate buffered saline (PBS) was used as a control. RCT: we recruited MSM with pharyngeal gonorrhoea who returned for treatment at the Melbourne Sexual Health Centre between May 2015 and February 2016. Untreated men were randomised to rinse and gargle either Listerine Cool Mint or saline for 1 min. Pharyngeal swabs were taken before and after rinsing and gargling for culture of N. gonorrhoeae . The analysis included only men who were culture positive for N. gonorrhoeae before using the allocated solution on the day of recruitment. In vitro: Listerine mouthwashes at dilutions of up to 1:4 for 1 min resulted in significant reduction of total N. gonorrhoeae counts but PBS has no inhibitory effect against N. gonorrhoeae . RCT: a total of 196 MSM were recruited, 58 (30%) were culture positive before using the solution. After gargling the allocated solution, men in the Listerine group were significantly less likely to be culture positive on the pharyngeal surface (52%) compared with men in the saline group (84%) (p=0.013). This data suggest Listerine, significantly reduces the amount of N. gonorrhoeae on the pharyngeal surface. With daily use it may increase gonococcal clearance and have important implications for prevention strategies. ACTRN12615000716561. Published by

  17. Non-cytotoxic nanomaterials enhance antimicrobial activities of cefmetazole against multidrug-resistant Neisseria gonorrhoeae.

    Directory of Open Access Journals (Sweden)

    Lan-Hui Li

    Full Text Available The emergence and spread of antibiotic-resistant Neisseria gonorrhoeae has led to difficulties in treating patients, and novel strategies to prevent and treat this infection are urgently needed. Here, we examined 21 different nanomaterials for their potential activity against N. gonorrhoeae (ATCC 49226. Silver nanoparticles (Ag NPs, 120 nm showed the greatest potency for reducing N. gonorrhoeae colony formation (MIC: 12.5 µg/ml and possessed the dominant influence on the antibacterial activity with their properties of the nanoparticles within a concentration range that did not induce cytotoxicity in human fibroblasts or epithelial cells. Electron microscopy revealed that the Ag NPs significantly reduced bacterial cell membrane integrity. Furthermore, the use of clinical isolates of multidrug-resistant N. gonorrhoeae showed that combined treatment with 120 nm Ag NPs and cefmetazole produced additive effects. This is the first report to screen the effectiveness of nanomaterials against N. gonorrhoeae, and our results indicate that 120 nm Ag NPs deliver low levels of toxicity to human epithelial cells and could be used as an adjuvant with antibiotic therapy, either for topical use or as a coating for biomaterials, to prevent or treat multidrug-resistant N. gonorrhoeae.

  18. Nanostructured platform for the detection of Neisseria gonorrhoeae using electrochemical impedance spectroscopy and differential pulse voltammetry

    International Nuclear Information System (INIS)

    Singh, R.; Matharu, Z.; Srivastava, A.K.; Sood, S.; Gupta, R.K.; Malhotra, B.D.

    2012-01-01

    We report on a nanocomposite based genosensor for the detection of Neisseria gonorrhoeae, a bacterium causing the sexually transmitted disease gonorrhoea. Amino-labeled probe DNA was covalently immobilized on electrochemically prepared polyaniline and iron oxide (PANI-Fe 3 O 4 ) nanocomposite film on an indium tin oxide (ITO) electrode. Scanning electron microscopy, transmission electron microscopy, electrochemical impedance spectroscopy (EIS) and differential pulse voltammetry (DPV) techniques have been employed to characterize surface of the modified electrode. The genosensor has detection limits of 1 x 10 -15 M and 1 x 10 -17 M, respectively, using the EIS and DPV techniques. This biosensor can discriminate a complementary sequence from a single-base mismatch and from non-complementary DNA, and has been utilized for detection of DNA extracted from N. gonorrhoeae culture, and from patient samples with N. gonorrhoeae. It is found to exhibit good specificity for N. gonorrhoeae species and shows no response towards non-gonorrhoeae type of Neisseria species (NgNs) and other gram-negative bacterias (GNBs). The affinity constant for hybridization calculated using the Langmuir adsorption isotherm model is found to be 3. 39 x 10 8 M -1 . (author)

  19. The Composition and Metabolic Phenotype of Neisseria gonorrhoeae Biofilms

    Directory of Open Access Journals (Sweden)

    Michael A Apicella

    2011-04-01

    Full Text Available N. gonorrhoeae has been shown to form biofilms during cervical infection. Thus, biofilm formation may play an important role in the infection of women. The ability of N. gonorrhoeae to form membrane blebs is crucial to biofilm formation. Blebs contain DNA and outer membrane structures, which have been shown to be major constituents of the biofilm matrix. The organism expresses a DNA thermonuclease that is involved in remodeling of the biofilm matrix. Comparison of the transcriptional profiles of gonococcal biofilms and planktonic runoff indicate that genes involved in anaerobic metabolism and oxidative stress tolerance are more highly expressed in biofilm. The expression of aniA, ccp, and norB, which encode nitrite reductase, cytochrome c peroxidase, and nitric oxide reductase respectively, is required for mature biofilm formation over glass and human cervical cells. In addition, anaerobic respiration occurs in the substratum of gonococcal biofilms and disruption of the norB gene required for anaerobic respiration, results in a severe biofilm attenuation phenotype. It has been demonstrated that accumulation of nitric oxide (NO contributes to the phenotype of a norB mutant and can retard biofilm formation. However, NO can also enhance biofilm formation, and this is largely dependent on the concentration and donation rate or steady state kinetics of NO. The majority of the genes involved in gonococcal oxidative stress tolerance are also required for normal biofilm formation, as mutations in the following genes result in attenuated biofilm formation over cervical cells and/or glass: oxyR, gor, prx, mntABC, trxB, and estD. Overall, biofilm formation appears to be an adaptation for coping with the environmental stresses present in the female genitourinary tract. Therefore, this review will discuss the studies, which describe the composition and metabolic phenotype of gonococcal biofilms.

  20. In Vitro Susceptibility of Neisseria gonorrhoeae Strains to Mupirocin, an Antibiotic Reformulated for Parenteral Administration in Nanoliposomes.

    Science.gov (United States)

    Cern, Ahuva; Connolly, Kristie L; Jerse, Ann E; Barenholz, Yechezkel

    2018-04-01

    Neisseria gonorrhoeae is an urgent antibiotic-resistant threat. This study determined the MICs of mupirocin to be 0.0039 to 0.0625 μg/ml for 94 N. gonorrhoeae strains. Cross-resistance with other antibiotics was not detected. Mupirocin, which is currently limited to topical administration, demonstrated activity by injection when delivered in nanoliposomes. The nanoliposomal formulation of mupirocin is a potential treatment for drug-resistant N. gonorrhoeae . Copyright © 2018 American Society for Microbiology.

  1. Travel-associated gonorrhoea in four Nordic countries, 2008 to 2013.

    Science.gov (United States)

    Beauté, Julien; Cowan, Susan; Hiltunen-Back, Eija; Kløvstad, Hilde; Velicko, Inga; Spiteri, Gianfranco

    2017-05-18

    Travel may be associated with a higher risk of gonorrhoea and infection by antibiotic-resistant strains. The objective of this study was to estimate the risk for gonorrhoea among travellers from four Nordic European countries using surveillance data and to identify at-risk travellers to help target interventions. We retrieved gonorrhoea surveillance data from Denmark, Finland, Norway and Sweden and tourism denominator data from the Statistical Office of the European Union. A travel-associated case of gonorrhoea was defined as one for which the reported country of infection differed from the reporting country. During 2008-2013, the four countries reported 3,224 travel-associated gonorrhoea cases, of which 53% were among individuals below 35 years of age. The overall risk associated with travel abroad was 2.4 cases per million nights abroad. The highest risk was observed with travel to Asia (9.4). Cases more likely to be reported as travel-associated were: males, heterosexuals of both sexes, people older than 65 years, and foreign-born individuals. More effective interventions targeting young adults and other at-risk groups are needed. The use of travel-planning websites and social media should be explored further. This article is copyright of The Authors, 2017.

  2. Antibodies with higher bactericidal activity induced by a Neisseria gonorrhoeae Rmp deletion mutant strain.

    Directory of Open Access Journals (Sweden)

    Guocai Li

    Full Text Available Neisseria gonorrhoeae (N. gonorrhoeae outer membrane protein reduction modifiable protein (Rmp has strong immunogenicity. However, anti-Rmp antibodies block rather than preserve the antibacterial effects of protective antibodies, which hampers the development of vaccines for gonococcal infections. We herein constructed an Rmp deletion mutant strain of N. gonorrhoeae by gene homologous recombination. The 261-460 nucleotide residues of Rmp gene amplified from N. gonorrhoeae WHO-A strain were replaced with a kanamycin-resistant Kan gene amplified from pET-28a. The resultant hybridized DNA was transformed into N. gonorrhoeae WHO-A strain. PCR was used to screen the colonies in which wild-type Rmp gene was replaced with a mutant gene fragment. Western blotting revealed that the Rmp deletion mutant strain did not express Rmp protein. Rmp deletion did not alter the morphological and Gram staining properties of the mutant strain that grew slightly more slowly than the wild-type one. Rmp gene mutated stably throughout 25 generations of passage. Antibody-mediated complement-dependent cytotoxicity assay indicated that the antibodies induced by the mutant strain had evidently higher bactericidal activities than those induced by the wild-type strain. Further modification of the Rmp deletion mutant strain is still required in the development of novel live attenuated vaccines for gonorrhea by Opa genes deletion or screening of phenotypic variant strains that do not express Opa proteins.

  3. Draft Genome Sequence of Neisseria gonorrhoeae Strain NG_869 with Penicillin, Tetracycline and Ciprofloxacin Resistance Determinants Isolated from Malaysia

    OpenAIRE

    Ang, Geik Yong; Yu, Choo Yee; Yong, Delicia Ann; Cheong, Yuet Meng; Yin, Wai-Fong; Chan, Kok-Gan

    2016-01-01

    Gonorrhea is a sexually transmitted infection caused by Neisseria gonorrhoeae and the increasing reports of multidrug-resistant gonococcal isolates are a global public health care concern. Herein, we report the genome sequence of N. gonorrhoeae strain NG_869 isolated from Malaysia which may provide insights into the drug resistance determinants in gonococcal bacteria.

  4. Exploring the Benefits of Molecular Testing for Gonorrhoea Antibiotic Resistance Surveillance in Remote Settings.

    Directory of Open Access Journals (Sweden)

    Ben B Hui

    Full Text Available Surveillance for gonorrhoea antimicrobial resistance (AMR is compromised by a move away from culture-based testing in favour of more convenient nucleic acid amplification test (NAAT tests. We assessed the potential benefit of a molecular resistance test in terms of the timeliness of detection of gonorrhoea AMR.An individual-based mathematical model was developed to describe the transmission of gonorrhoea in a remote Indigenous population in Australia. We estimated the impact of the molecular test on the time delay between first importation and the first confirmation that the prevalence of gonorrhoea AMR (resistance proportion has breached the WHO-recommended 5% threshold (when a change in antibiotic should occur. In the remote setting evaluated in this study, the model predicts that when culture is the only available means of testing for AMR, the breach will only be detected when the actual prevalence of AMR in the population has already reached 8 - 18%, with an associated delay of ~43 - 69 months between first importation and detection. With the addition of a molecular resistance test, the number of samples for which AMR can be determined increases facilitating earlier detection at a lower resistance proportion. For the best case scenario, where AMR can be determined for all diagnostic samples, the alert would be triggered at least 8 months earlier than using culture alone and the resistance proportion will have only slightly exceeded the 5% notification threshold.Molecular tests have the potential to provide more timely warning of the emergence of gonorrhoea AMR. This in turn will facilitate earlier treatment switching and more targeted treatment, which has the potential to reduce the population impact of gonorrhoea AMR.

  5. Exploring the Benefits of Molecular Testing for Gonorrhoea Antibiotic Resistance Surveillance in Remote Settings.

    Science.gov (United States)

    Hui, Ben B; Ryder, Nathan; Su, Jiunn-Yih; Ward, James; Chen, Marcus Y; Donovan, Basil; Fairley, Christopher K; Guy, Rebecca J; Lahra, Monica M; Law, Mathew G; Whiley, David M; Regan, David G

    2015-01-01

    Surveillance for gonorrhoea antimicrobial resistance (AMR) is compromised by a move away from culture-based testing in favour of more convenient nucleic acid amplification test (NAAT) tests. We assessed the potential benefit of a molecular resistance test in terms of the timeliness of detection of gonorrhoea AMR. An individual-based mathematical model was developed to describe the transmission of gonorrhoea in a remote Indigenous population in Australia. We estimated the impact of the molecular test on the time delay between first importation and the first confirmation that the prevalence of gonorrhoea AMR (resistance proportion) has breached the WHO-recommended 5% threshold (when a change in antibiotic should occur). In the remote setting evaluated in this study, the model predicts that when culture is the only available means of testing for AMR, the breach will only be detected when the actual prevalence of AMR in the population has already reached 8 - 18%, with an associated delay of ~43 - 69 months between first importation and detection. With the addition of a molecular resistance test, the number of samples for which AMR can be determined increases facilitating earlier detection at a lower resistance proportion. For the best case scenario, where AMR can be determined for all diagnostic samples, the alert would be triggered at least 8 months earlier than using culture alone and the resistance proportion will have only slightly exceeded the 5% notification threshold. Molecular tests have the potential to provide more timely warning of the emergence of gonorrhoea AMR. This in turn will facilitate earlier treatment switching and more targeted treatment, which has the potential to reduce the population impact of gonorrhoea AMR.

  6. Neisseria gonorrhoeae co-infection exacerbates vaginal HIV shedding without affecting systemic viral loads in human CD34+ engrafted mice.

    Directory of Open Access Journals (Sweden)

    Stacey X Xu

    Full Text Available HIV synergy with sexually transmitted co-infections is well-documented in the clinic. Co-infection with Neisseria gonorrhoeae in particular, increases genital HIV shedding and mucosal transmission. However, no animal model of co-infection currently exists to directly explore this relationship or to bridge the gap in understanding between clinical and in vitro studies of this interaction. This study aims to test the feasibility of using a humanized mouse model to overcome this barrier. Combining recent in vivo modelling advancements in both HIV and gonococcal research, we developed a co-infection model by engrafting immunodeficient NSG mice with human CD34+ hematopoietic stem cells to generate humanized mice that permit both systemic HIV infection and genital N. gonorrhoeae infection. Systemic plasma and vaginal lavage titres of HIV were measured in order to assess the impact of gonococcal challenge on viral plasma titres and genital shedding. Engrafted mice showed human CD45+ leukocyte repopulation in blood and mucosal tissues. Systemic HIV challenge resulted in 104-105 copies/mL of viral RNA in blood by week 4 post-infection, as well as vaginal shedding of virus. Subsequent gonococcal challenge resulted in unchanged plasma HIV levels but higher viral shedding in the genital tract, which reflects published clinical observations. Thus, human CD34+ stem cell-transplanted NSG mice represent an experimentally tractable animal model in which to study HIV shedding during gonococcal co-infection, allowing dissection of molecular and immunological interactions between these pathogens, and providing a platform to assess future therapeutics aimed at reducing HIV transmission.

  7. Neisseria gonorrhoeae co-infection exacerbates vaginal HIV shedding without affecting systemic viral loads in human CD34+ engrafted mice.

    Science.gov (United States)

    Xu, Stacey X; Leontyev, Danila; Kaul, Rupert; Gray-Owen, Scott D

    2018-01-01

    HIV synergy with sexually transmitted co-infections is well-documented in the clinic. Co-infection with Neisseria gonorrhoeae in particular, increases genital HIV shedding and mucosal transmission. However, no animal model of co-infection currently exists to directly explore this relationship or to bridge the gap in understanding between clinical and in vitro studies of this interaction. This study aims to test the feasibility of using a humanized mouse model to overcome this barrier. Combining recent in vivo modelling advancements in both HIV and gonococcal research, we developed a co-infection model by engrafting immunodeficient NSG mice with human CD34+ hematopoietic stem cells to generate humanized mice that permit both systemic HIV infection and genital N. gonorrhoeae infection. Systemic plasma and vaginal lavage titres of HIV were measured in order to assess the impact of gonococcal challenge on viral plasma titres and genital shedding. Engrafted mice showed human CD45+ leukocyte repopulation in blood and mucosal tissues. Systemic HIV challenge resulted in 104-105 copies/mL of viral RNA in blood by week 4 post-infection, as well as vaginal shedding of virus. Subsequent gonococcal challenge resulted in unchanged plasma HIV levels but higher viral shedding in the genital tract, which reflects published clinical observations. Thus, human CD34+ stem cell-transplanted NSG mice represent an experimentally tractable animal model in which to study HIV shedding during gonococcal co-infection, allowing dissection of molecular and immunological interactions between these pathogens, and providing a platform to assess future therapeutics aimed at reducing HIV transmission.

  8. SIGNIFICATIVE ANO PROBLEM BASED LEARNING IN IMMUNOLOGY: OBTAINING A KIT TO TYPE NEISSERIA GONORRHOEAE

    Directory of Open Access Journals (Sweden)

    Marina Miguez

    2003-06-01

    Full Text Available Neisseria gonorrhoeae (Ng have been classified serologically on the basis of the antigenicity of the major porin (Por. Por! occurs in two immunochemically distinct serogroups: PorlA and Porffi. Because the diagnostic, therapeutic, social, and legal corisequences of misidentification of a nongonococcal Neisseria isolate as Ng can be substantial, the accurate and rapid identification of this organism is important. Typifying of Ng is done by techniques baséd on phenotypic characteristics and plasmidic content that individually don't reach an adequate discrimination, and so combination of techniques ·must be used. The aim of this work is to obtain polyclonal specificAb that discriminate Ng types Por!Aand Porffi. For this purpose, weimmunized two rabbits with sonicated PorlA and Porm strains ofNg (isolated from clínica! samples and serologically classified. The Ab response was analyzed along the protocol by ELISAand by direct agglutination with latex coated with sonicated Ng. With these data, we selected the bleeding providing the serum with maximum specific Ab ti ter to prepare the typing reagents. Unwanted Ab directed against shared epitopes were removed by adsorption with Ng latex. The typing reagents were obtained by coating latex with each depleted sera. Our results suggest that high titers of specific Ab be obtained for both strains ofNg and the depleted sera be discriminated between both strains. These results suggest that these diagnostic reagents could be useful to confirrn presumptive identification by a simple and rapid method.

  9. Control of gdhR Expression in Neisseria gonorrhoeae via Autoregulation and a Master Repressor (MtrR of a Drug Efflux Pump Operon

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    Corinne E. Rouquette-Loughlin

    2017-04-01

    Full Text Available The MtrCDE efflux pump of Neisseria gonorrhoeae contributes to gonococcal resistance to a number of antibiotics used previously or currently in treatment of gonorrhea, as well as to host-derived antimicrobials that participate in innate defense. Overexpression of the MtrCDE efflux pump increases gonococcal survival and fitness during experimental lower genital tract infection of female mice. Transcription of mtrCDE can be repressed by the DNA-binding protein MtrR, which also acts as a global regulator of genes involved in important metabolic, physiologic, or regulatory processes. Here, we investigated whether a gene downstream of mtrCDE, previously annotated gdhR in Neisseria meningitidis, is a target for regulation by MtrR. In meningococci, GdhR serves as a regulator of genes involved in glucose catabolism, amino acid transport, and biosynthesis, including gdhA, which encodes an l-glutamate dehydrogenase and is located next to gdhR but is transcriptionally divergent. We report here that in N. gonorrhoeae, expression of gdhR is subject to autoregulation by GdhR and direct repression by MtrR. Importantly, loss of GdhR significantly increased gonococcal fitness compared to a complemented mutant strain during experimental murine infection. Interestingly, loss of GdhR did not influence expression of gdhA, as reported for meningococci. This variance is most likely due to differences in promoter localization and utilization between gonococci and meningococci. We propose that transcriptional control of gonococcal genes through the action of MtrR and GdhR contributes to fitness of N. gonorrhoeae during infection.

  10. Resistencia de Neisseria gonorrhoeae a ciprofloxacina según hábitos sexuales Ciprofloxacin resistance of Neisseria gonorrhoeae according to sexual habits

    Directory of Open Access Journals (Sweden)

    Susana García

    2008-10-01

    Full Text Available En la Argentina los primeros hallazgos de Neisseria gonorrhoeae resistentes a las fluorquinolonas se documentaron en el año 2000. Desde enero de 2005 hasta junio de 2007, se evaluaron 595 hombres que tienen sexo con hombres (HSH y 571 varones heterosexuales para investigar la presencia de N. gonorrhoeae y la resistencia a los antimicrobianos. La prevalencia de gonorrea en HSH y varones heterosexuales fue 0.091(91/1000 en ambos grupos y el % de N. gonorrhoeae resistente a ciprofloxacina (NGRC fue 20.0% y 3.8% respectivamente (p: 0.0416. Trece de 106 aislamientos fueron NGRC, correspondieron a 11 HSH y 2 varones heterosexuales. Seis HSH presentaron uretritis, uno de ellos con localización simultánea en recto y cinco pacientes fueron asintomáticos (recto, 2; faringe, 2; uretra, 1. No se pudo demostrar relación epidemiológica entre ellos. Dos varones heterosexuales presentaron uretritis. Los 8 pacientes sintomáticos fueron tratados empíricamente con ciprofloxacina y se documentó fracaso de tratamiento. Estos y los portadores de NGRC recibieron tratamiento con 500 mg de ceftriaxona IM. Los controles postratamiento demostraron la erradicación del microorganismo. Los aislamientos de NGRC presentaron CIM de ciprofloxacina entre 2 y 32 µg/ml, todos fueron beta-lactamasa negativos, 4/13 presentaron resistencia cromosómica a penicilina (CIM= 1 µg/ml, y los rangos de CIM (µg/ml para los siguientes antibióticos fueron: penicilina: 0.016-1; tetraciclina: 0.125-2; ceftriaxona: 0.004-0.008; eritromicina: 0.032-2; azitromicina: 0.032-0.5; espectinomicina: 8-32. Dado el elevado porcentaje de aislamientos de NGRC en HSH en nuestro hospital, debería utilizarse otro antimicrobiano para el tratamiento empírico en estos pacientes.The first isolates of Neisseria gonorrhoeae resistant to fluorquinolones in Argentina were reported in 2000. Since January 2005 to June 2007 Neisseria gonorrhoeae was studied in 595 men who have sex with men (MSM and 571

  11. Concordance of gonorrhoea of the rectum, pharynx and urethra in same-sex male partnerships attending a sexual health service in Melbourne, Australia.

    Science.gov (United States)

    Cornelisse, Vincent J; Zhang, Lei; Law, Matthew; Chen, Marcus Y; Bradshaw, Catriona S; Bellhouse, Clare; Fairley, Christopher K; Chow, Eric P F

    2018-02-27

    We aimed to describe anatomic site-specific concordance of gonococcal infections in partnerships of men who have sex with men (MSM). We conducted a cross-sectional analysis of data from MSM partnerships attending Melbourne Sexual Health Centre between March 2011 and February 2015. Logistic regression models (random effect) were used to examine the association between gonococcal infections of the urethra, rectum and pharynx. Gonococci were detected by culture at all anatomic sites. The analysis included 495 partnerships. Of the men with urethral gonorrhoea, 33% (95% CI 18-52) had partners with pharyngeal gonorrhoea and 67% (95% CI 48-82) had partners with rectal gonorrhoea. The adjusted odds of having urethral gonorrhoea was 4.6 (95% CI 1.2-17.1) for a man whose partner had pharyngeal gonorrhoea, and 48.1 (95% CI 18.3-126.7) for a man whose partner had rectal gonorrhoea. Of the men with rectal gonorrhoea, 46% (95% CI 31-61) had a partner with urethral gonorrhoea and 23% (95% CI 12-37) had a partner with pharyngeal gonorrhoea. The adjusted odds of having rectal gonorrhoea was 63.9 (95% CI 24.7-165.6) for a man whose partner had urethral gonorrhoea. Of the men with pharyngeal gonorrhoea, 42% (95% CI 23-63) had a partner with rectal gonorrhoea and 23% (95% CI 9-44) had a partner with had a partner with pharyngeal gonorrhoea. The adjusted odds of having pharyngeal gonorrhoea was 8.9 (95% CI 3.2-24.6) for a man whose partner had rectal gonorrhoea. The crude odds of having pharyngeal gonorrhoea was 14.2 (95% CI 5.1-39.0) for a man whose partner had pharyngeal gonorrhoea. These data provide the first estimates of concordance of anatomic site-specific gonococcal infections in MSM partnerships, and confirm that urethral gonorrhoea is contracted from both rectal and pharyngeal sites, and suggest that gonococci transmit between the rectum and pharynx. However, due to use of culture rather than NAAT, our analysis was not adequately powered to assess pharynx

  12. Characterization of a catalase-deficient strain of Neisseria gonorrhoeae: evidence for the significance of catalase in the biology of N. gonorrhoeae.

    OpenAIRE

    Johnson, S R; Steiner, B M; Cruce, D D; Perkins, G H; Arko, R J

    1993-01-01

    We obtained a catalase-deficient (Kat-) strain of Neisseria gonorrhoeae isolated from a patient who had been unsuccessfully treated with penicillin. Quantitative enzyme assays and electrophoresis of cell extracts on native polyacrylamide gels subsequently stained for catalase and peroxidase activities failed to detect both enzymes. The strain exhibited no growth anomalies or unusual requirements when grown under ordinary laboratory conditions. However, the Kat- strain proved extremely sensiti...

  13. Neisseria gonorrhoeae strain with reduced susceptibilities to extended-spectrum cephalosporins.

    Science.gov (United States)

    Nguyen, Duylinh; Gose, Severin; Castro, Lina; Chung, Kathleen; Bernstein, Kyle; Samuel, Micheal; Bauer, Heidi; Pandori, Mark

    2014-07-01

    The spread of Neisseria gonorrhoeae strains with reduced susceptibility to extended-spectrum cephalosporins is an increasing public health threat. Using Etest and multiantigen sequence typing, we detected sequence type 1407, which is associated with reduced susceptibilities to extended-spectrum cephalosporins, in 4 major populated regions in California, USA, in 2012.

  14. Comparison of four techniques for the confirmatory identification of Neisseria gonorrhoeae

    International Nuclear Information System (INIS)

    Jacobs, P.F.

    1980-01-01

    The authors have compared four assay techniques for the confirmatory identification of Neisseria gonorrhoeae. On of these is a radiometric assay, based on the measurement of liberated radiolabelled CO 2 from metabolized carbohydrates which have been tagged with 14 C. The assay uses glucose, maltose and fructose as its differentiating sugars, plus the ONPG reaction, and can be read in three hours. (Auth.)

  15. Mutation in ribosomal protein S5 leads to spectinomycin resistance in Neisseria gonorrhoeae.

    Directory of Open Access Journals (Sweden)

    Elena eIlina

    2013-07-01

    Full Text Available Spectinomycin remains a useful reserve option for therapy of gonorrhea. The emergence of multidrug-resistant Neisseria gonorrhoeae strains with decreased susceptibility to cefixime and to ceftriaxone makes it the only medicine still effective for treatment of gonorrhea infection in analogous cases. However, adoption of spectinomycin as a routinely used drug of choice was soon followed by reports of spectinomycin resistance. The main molecular mechanism of spectinomycin resistance in N. gonorrhoeae was C1192T substitution in 16S rRNA genes. Here we reported a Thr-24→Pro mutation in ribosomal protein S5 found in spectinomycin resistant clinical N. gonorrhoeae strain, which carried no changes in 16S rRNA. In a series of experiments, the transfer of rpsE gene allele encoding the mutant ribosomal protein S5 to the recipient N. gonorrhoeae strains was analyzed. The relatively high rate of transformation (ca. 10-5 CFUs indicates the possibility of spread of spectinonycin resistance within gonococcal population due to the horizontal gene transfer.

  16. Diagnostic aspects of infections with Chlamydia trachomatis, Neisseria gonorrhoeae and herpes simplex virus

    NARCIS (Netherlands)

    J. Ulsen (Josina)

    1994-01-01

    textabstractThe sexually transmitted diseases (STOs) constitute a worldwide problem of major significance in terms of health. economic and social consequences. The most important STOs are Ihe bacterial infections syphilis (causative agent Treponema pal/idum sub·species pallidum), gonorrhoea

  17. Reproducibility Problems with the Abbott Laboratories LCx Assay for Chlamydia trachomatis and Neisseria gonorrhoeae

    OpenAIRE

    Gronowski, Ann M.; Copper, Susan; Baorto, David; Murray, Patrick R.

    2000-01-01

    This study demonstrates that significant reproducibility problems can occur during routine use of the Abbott Laboratories LCx assay for Chlamydia trachomatis and Neisseria gonorrhoeae. These problems can go undetected by the quality control procedures outlined in the manufacturer's package insert. We outline here procedures for detecting and preventing contamination and reproducibility problems.

  18. Syphilis, gonorrhoea, leprosy and yaws in the Indonesian Archipelago, 1500-1950

    NARCIS (Netherlands)

    Boomgaard, P.

    2007-01-01

    This paper dexamines the history of sexually transmitted diseases in Southeast Asia and explores the origins of venereal disease, specifically syphilis and gonorrhoea, in the region. The arrival of new diseases that accompanied Europeans from about 1500, is a subject that scholars have largely

  19. Extragenital Infections Caused by Chlamydia trachomatis and Neisseria gonorrhoeae: A Review of the Literature

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    Philip A. Chan

    2016-01-01

    Full Text Available In the United States, sexually transmitted diseases due to Chlamydia trachomatis and Neisseria gonorrhoeae continue to be a major public health burden. Screening of extragenital sites including the oropharynx and rectum is an emerging practice based on recent studies highlighting the prevalence of infection at these sites. We reviewed studies reporting the prevalence of extragenital infections in women, men who have sex with men (MSM, and men who have sex only with women (MSW, including distribution by anatomical site. Among women, prevalence was found to be 0.6–35.8% for rectal gonorrhea (median reported prevalence 1.9%, 0–29.6% for pharyngeal gonorrhea (median 2.1%, 2.0–77.3% for rectal chlamydia (median 8.7%, and 0.2–3.2% for pharyngeal chlamydia (median 1.7%. Among MSM, prevalence was found to be 0.2–24.0% for rectal gonorrhea (median 5.9%, 0.5–16.5% for pharyngeal gonorrhea (median 4.6%, 2.1–23.0% for rectal chlamydia (median 8.9%, and 0–3.6% for pharyngeal chlamydia (median 1.7%. Among MSW, the prevalence was found to be 0–5.7% for rectal gonorrhea (median 3.4%, 0.4–15.5% for pharyngeal gonorrhea (median 2.2%, 0–11.8% for rectal chlamydia (median 7.7%, and 0–22.0% for pharyngeal chlamydia (median 1.6%. Extragenital infections are often asymptomatic and found in the absence of reported risk behaviors, such as receptive anal and oral intercourse. We discuss current clinical recommendations and future directions for research.

  20. The prevalence of Chlamydia trachomatis and Neisseria gonorrhoeae infections among men with urethritis in Kuwait.

    Science.gov (United States)

    Al-Sweih, N A; Khan, S; Rotimi, V O

    2011-09-01

    Chlamydial non-gonococcal urethritis and gonorrhoea are the most common sexually transmitted bacterial infections worldwide. Data on these infections are scanty in the Islamic world, especially Kuwait. The objective of this study was to establish the prevalence of Chlamydia trachomatis and Neisseria gonorrhoeae among men with symptomatic urethritis in Kuwait. Men with urethral discharge seen and managed at eight governmental hospitals were recruited into the study. A pair of urethral swab and first-voided urine sample were taken from the patients and sent immediately to the laboratory where they were processed using strand displacement nucleic acid amplification kits (SDA; ProbeTec, Becton Dickinson); one pair per patient was studied. A total of 426 symptomatic men were studied, out of whom 155 (36.4%) were infected by either C. trachomatis or N. gonorrhoeae, or both. The overall prevalence rates of C. trachomatis and N. gonorrhoeae were 12.4% and 23.9%, respectively. There was no significant difference in chlamydial and gonococcal prevalence between Kuwaiti men and non-Kuwaitis (P>0.05). Infection rates were much lower in married men than unmarried men. Men in the age range of 21-35 years were more vulnerable to both infections. The findings show that N. gonorrhoeae and, to a lesser extent, C. trachomatis are common in men with urethritis in Kuwait. Appropriate preventive strategies that conform to Islamic rules and values should be of highest priority of the policymakers. Copyright © 2011 King Saud Bin Abdulaziz University for Health Sciences. Published by Elsevier Ltd. All rights reserved.

  1. Neisseria gonorrhoeae Modulates Immunity by Polarizing Human Macrophages to a M2 Profile.

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    María Carolina Ortiz

    Full Text Available Current data suggest that Neisseria gonorrhoeae is able to suppress the protective immune response at different levels, such as B and T lymphocytes and antigen-presenting cells. The present report is focused on gonococcus evasion mechanism on macrophages (MФ and its impact in the subsequent immune response. In response to various signals MФ may undergo classical-M1 (M1-MФ or alternative-M2 (M2-MФ activation. Until now there are no reports of the gonococcus effects on human MФ polarization. We assessed the phagocytic ability of monocyte-derived MФ (MDM upon gonococcal infection by immunofluorescence and gentamicin protection experiments. Then, we evaluated cytokine profile and M1/M2 specific-surface markers on MФ challenged with N. gonorrhoeae and their proliferative effect on T cells. Our findings lead us to suggest N. gonorrhoeae stimulates a M2-MФ phenotype in which some of the M2b and none of the M1-MФ-associated markers are induced. Interestingly, N. gonorrhoeae exposure leads to upregulation of a Programmed Death Ligand 1 (PD-L1, widely known as an immunosuppressive molecule. Moreover, functional results showed that N. gonorrhoeae-treated MФ are unable to induce proliferation of human T-cells, suggesting a more likely regulatory phenotype. Taken together, our data show that N. gonorroheae interferes with MФ polarization. This study has important implications for understanding the mechanisms of clearance versus long-term persistence of N. gonorroheae infection and might be applicable for the development of new therapeutic strategies.

  2. Proteomics of Neisseria gonorrhoeae: the treasure hunt for countermeasures against an old disease

    Directory of Open Access Journals (Sweden)

    Benjamin I Baarda

    2015-10-01

    Full Text Available Neisseria gonorrhoeae is an exquisitely adapted, strictly human pathogen and the causative agent of the sexually transmitted infection gonorrhea. This ancient human disease remains a serious problem, occurring at high incidence globally and having a major impact on reproductive and neonatal health. N. gonorrhoeae is rapidly evolving into a superbug and no effective vaccine exists to prevent gonococcal infections. Untreated or inadequately treated gonorrhea can lead to severe sequelae, including pelvic inflammatory disease and infertility in women, epididymitis in men, and sight- threatening conjunctivitis in infants born to infected mothers. Therefore, there is an immediate need for accelerated research toward the identification of molecular targets for development of drugs with new mechanisms of action and preventive vaccine(s. Global proteomic approaches are ideally suited to guide these studies. Recent quantitative proteomics (SILAC, iTRAQ, and ICAT have illuminated the pathways utilized by N. gonorrhoeae to adapt to different lifestyles and micro-ecological niches within the host, while comparative 2D SDS-PAGE analysis has been used to elucidate spectinomycin resistance mechanisms. Further, high-throughput examinations of cell envelopes and naturally released membrane vesicles have unveiled the ubiquitous and differentially expressed proteins between temporally and geographically diverse N. gonorrhoeae isolates. This review will focus on these different approaches, emphasizing the role of proteomics in the search for vaccine candidates. Although our knowledge of N. gonorrhoeae has been expanded, still far less is known about this bacterium than the closely related N. meningitidis, where genomics- and proteomics-driven studies have led to the successful development of vaccines.

  3. Molecular epidemiology of Neisseria gonorrhoeae strains circulating in Indonesia using multi-locus variable number tandem repeat analysis (MLVA) and Neisseria gonorrhoeae multi-antigen sequence typing (NG-NAST) techniques

    NARCIS (Netherlands)

    Hananta, I. Putu Yuda; van Dam, Alje Pieter; Schim van der Loeff, Maarten Franciscus; Dierdorp, Mirjam; Wind, Carolien Marleen; Soebono, Hardyanto; de Vries, Henry John Christiaan; Bruisten, Sylvia Maria

    2018-01-01

    Background: Control of gonorrhea in resource-limited countries, such as Indonesia, is mostly unsuccessful. Examining Neisseria gonorrhoeae (Ng) transmission networks using strain typing might help prioritizing public health interventions. Methods: In 2014, urogenital Ng strains were isolated from

  4. Use of nfsB, encoding nitroreductase, as a reporter gene to determine the mutational spectrum of spontaneous mutations in Neisseria gonorrhoeae

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    Dunham Stephen

    2009-11-01

    Full Text Available Abstract Background Organisms that are sensitive to nitrofurantoin express a nitroreductase. Since bacterial resistance to this compound results primarily from mutations in the gene encoding nitroreductase, the resulting loss of function of nitroreductase results in a selectable phenotype; resistance to nitrofurantoin. We exploited this direct selection for mutation to study the frequency at which spontaneous mutations arise (transitions and transversions, insertions and deletions. Results A nitroreductase- encoding gene was identified in the N. gonorrhoeae FA1090 genome by using a bioinformatic search with the deduced amino acid sequence derived from the Escherichia coli nitroreductase gene, nfsB. Cell extracts from N. gonorrhoeae were shown to possess nitroreductase activity, and activity was shown to be the result of NfsB. Spontaneous nitrofurantoin-resistant mutants arose at a frequency of ~3 × 10-6 - 8 × 10-8 among the various strains tested. The nfsB sequence was amplified from various nitrofurantoin-resistant mutants, and the nature of the mutations determined. Transition, transversion, insertion and deletion mutations were all readily detectable with this reporter gene. Conclusion We found that nfsB is a useful reporter gene for measuring spontaneous mutation frequencies. Furthermore, we found that mutations were more likely to arise in homopolymeric runs rather than as base substitutions.

  5. Social capital, poverty, and income inequality as predictors of gonorrhoea, syphilis, chlamydia and AIDS case rates in the United States

    OpenAIRE

    Holtgrave, D; Crosby, R

    2003-01-01

    Objective: This study examined the state level association between social capital, poverty, income inequality, and four infectious diseases that have important public health implications given their long term sequelae: gonorrhoea, syphilis, chlamydia, and AIDS.

  6. Detection of mutations in mtrR gene in quinolone resistant strains of N.gonorrhoeae isolated from India

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    S V Kulkarni

    2015-01-01

    Full Text Available Background and Objectives: Emergence of multi-drug resistant Neisseria gonorrhoeae resulting from new genetic mutation is a serious threat in controlling gonorrhea. This study was undertaken to identify and characterise mutations in the mtrR genes in N.gonorrhoeae isolates resistant to six different antibiotics in the quinolone group. Materials and Methods: The Minimum inhibitory concentrations (MIC of five quinolones for 64 N.gonorrhoeae isolates isolated during Jan 2007-Jun 2009 were determined by E-test method. Mutations in MtrR loci were examined by deoxyribonucleic acid (DNA sequencing. Results: The proportion of N.gonorrhoeae strains resistant to anti-microbials was 98.4% for norfloxacin and ofloxacin, 96.8% for enoxacin and ciprofloxacin, 95.3% for lomefloxacin. Thirty-one (48.4% strains showed mutation (single/multiple in mtrR gene. Ten different mutations were observed and Gly-45 → Asp, Tyr-105 → His being the most common observed mutation. Conclusion: This is the first report from India on quinolone resistance mutations in MtrRCDE efflux system in N.gonorrhoeae. In conclusion, the high level of resistance to quinolone and single or multiple mutations in mtrR gene could limit the drug choices for gonorrhoea.

  7. Nucleic acid amplification tests (NAATs for gonorrhoea diagnosis in women: Experience of a tertiary care hospital in north India

    Directory of Open Access Journals (Sweden)

    Seema Sood

    2014-01-01

    Full Text Available Background & objectives: Gonorrhoea is among the most frequent of the estimated bacterial sexually transmitted infections (STIs and has significant health implications in women. The use of nucleic acid amplification tests (NAATs has been shown to provide enhanced diagnosis of gonorrhoea in female patients. However, it is recommended that an on-going assessment of the test assays should be performed to check for any probable sequence variation occurring in the targeted region. In this study, an in-house PCR targeting opa-gene of Neisseria gonorrhoeae was used in conjunction with 16S ribosomal PCR to determine the presence of gonorrhoea in female patients attending the tertiary care hospitals. Methods: Endocervical samples collected from 250 female patients with complaints of vaginal or cervical discharge or pain in lower abdomen were tested using opa and 16S ribosomal assay. The samples were also processed by conventional methods. Results: Of the 250 female patients included in the study, only one was positive by conventional methods (microscopy and culture whereas 17 patients were found to be positive based on PCR results. Interpretation & conclusions: The clinical sensitivity of conventional methods for the detection of N. gonorrhoeae in female patients was low. The gonococcal detection rates increased when molecular method was used giving 16 additional positives. Studies should be done to find out other gene targets that may be used in the screening assays to detect the presence of gonorrhoea.

  8. Sustained transmission of high-level azithromycin-resistant Neisseria gonorrhoeae in England: an observational study.

    Science.gov (United States)

    Fifer, Helen; Cole, Michelle; Hughes, Gwenda; Padfield, Simon; Smolarchuk, Christa; Woodford, Neil; Wensley, Adrian; Mustafa, Nazim; Schaefer, Ulf; Myers, Richard; Templeton, Kate; Shepherd, Jill; Underwood, Anthony

    2018-05-01

    Between Nov 3, 2014, and Feb 24, 2017, 70 cases of high-level azithromycin-resistant (HL-AziR; minimum inhibitory concentration [MIC] ≥256 mg/L) Neisseria gonorrhoeae were reported from across England. Whole-genome sequencing was done to investigate this outbreak to determine whether the ongoing outbreak represented clonal spread of an HL-AziR N gonorrhoeae strain identified in Leeds. We also wanted to elucidate the molecular mechanisms of azithromycin resistance in N gonorrhoeae in the UK. In this observational study, whole-genome sequencing was done on the HL-AziR N gonorrhoeae isolates from England. As comparators, 110 isolates from the UK and Ireland with a range of azithromycin MICs were also sequenced, including eight isolates from Scotland with azithromycin MICs ranging from 0·12 mg/L to 1·00 mg/L that were N gonorrhoeae multi-antigen sequence type 9768 (ST9768), which was the sequence type initially responsible for the outbreak. The presence of mutations or genes associated with azithromycin resistance was also investigated. 37 of the 60 HL-AziR isolates from England belonged to ST9768, and were genetically similar (mean 4·3 single-nucleotide polymorphisms). A 2059A→G mutation was detected in three or all four alleles of the 23S rRNA gene. Five susceptible ST9768 isolates had one mutated 23S rRNA allele and one low-level resistant ST9768 isolate had two mutated alleles. Sustained transmission of a successful HL-AziR clone was seen across England. Mutation 2059A→G was found in isolates with lower azithromycin MICs. Azithromycin exposure might have provided the selection pressure for one or two mutated copies of the 23S rRNA gene to recombine with wild-type copies, leading to three or four mutated copies and the HL-AziR phenotype. HL-AziR could emerge in isolates with low azithromycin MICs and eliminate the effectiveness of azithromycin as part of dual therapy for the treatment of gonorrhoea. Public Health England. Copyright © 2018 Elsevier Ltd. All

  9. Crystal structure of the Neisseria gonorrhoeae MtrD inner membrane multidrug efflux pump.

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    Jani Reddy Bolla

    Full Text Available Neisseria gonorrhoeae is an obligate human pathogen and the causative agent of the sexually-transmitted disease gonorrhea. The control of this disease has been compromised by the increasing proportion of infections due to antibiotic-resistant strains, which are growing at an alarming rate. The MtrCDE tripartite multidrug efflux pump, belonging to the hydrophobic and amphiphilic efflux resistance-nodulation-cell division (HAE-RND family, spans both the inner and outer membranes of N. gonorrhoeae and confers resistance to a variety of antibiotics and toxic compounds. We here report the crystal structure of the inner membrane MtrD multidrug efflux pump, which reveals a novel structural feature that is not found in other RND efflux pumps.

  10. Chlamydia trachomatis Serovar Distribution and Neisseria gonorrhoeae Coinfection in Male Patients with Urethritis in Greece▿

    Science.gov (United States)

    Papadogeorgakis, Helen; Pittaras, Theodore E.; Papaparaskevas, Joseph; Pitiriga, Vassiliki; Katsambas, Andreas; Tsakris, Athanassios

    2010-01-01

    The distribution of Chlamydia trachomatis serovars and Neisseria gonorrhoeae coinfection was studied in a group of 100 C. trachomatis-positive males with urethritis in Greece. The serovar distribution revealed that apart from the predominant worldwide types E and F, the relatively uncommon type G is also prevalent. Gonococcal coinfection was frequent (30%) and was associated with genovariant Ja (75%, P = 0.008). PMID:20357220

  11. Chlamydia trachomatis and Neisseria gonorrhoeae in asymptomatic family planning patients in rural New Mexico.

    OpenAIRE

    Bell, T A; Ebenezer, M R

    1989-01-01

    We tested 98 asymptomatic women seen in state-funded contraception clinics in rural New Mexico. A fluorescein-conjugated monoclonal antibody stain revealed Chlamydia trachomatis infection in 25% of asymptomatic unmarried women and 3% of married women (P = .03). Neisseria gonorrhoeae was detected in only one woman. As in urban clinics providing contraception, the prevalence of gonorrhea is rare in rural New Mexico, but chlamydial infections are common in young unmarried women.

  12. The distribution of chlamydia, gonorrhoea and syphilis cases across states and counties in the USA, 2007.

    Science.gov (United States)

    Chesson, Harrell W; Sternberg, Maya; Leichliter, Jami S; Aral, Sevgi O

    2010-12-01

    To examine the distribution of chlamydia, gonorrhoea and syphilis in the USA through the use of Lorenz curves and Gini coefficients. The distribution of three sexually transmitted diseases (STD; chlamydia, gonorrhoea and primary and secondary syphilis) was examined across states and counties in the USA in 2007, based on reported case numbers. Gini coefficients, which can range from 0 (equality in STD rates across geographical units) to 1 (complete inequality such that all STD occur in one geographical unit) were calculated. Overall, chlamydia was the most evenly distributed and syphilis was the most concentrated of the three STD examined. The Gini coefficients for chlamydia, gonorrhoea and syphilis were 0.121, 0.255 and 0.334, respectively, when examined across states, and 0.319, 0.494 and 0.630, respectively, when examined across counties. Differences in Gini coefficients were observed when the STD distributions were examined by sex, race/ethnicity and age group. The use of Lorenz curves and Gini coefficients can help to assess inequalities in the distribution of STD, to gauge the suitability of geographically targeted interventions, and to help in determining the epidemic phase of STD. Having a better understanding of the disparities in the distribution of STD across states and counties by sex, race/ethnicity and age group might help in understanding why disparities in STD rates exist across different groups and in developing interventions to address these disparities.

  13. Nationwide surveillance of the antimicrobial susceptibility of Neisseria gonorrhoeae from male urethritis in Japan.

    Science.gov (United States)

    Hamasuna, Ryoichi; Yasuda, Mitsuru; Ishikawa, Kiyohito; Uehara, Shinya; Takahashi, Satoshi; Hayami, Hiroshi; Yamamoto, Shingo; Matsumoto, Tetsuro; Minamitani, Shinichi; Watanabe, Akira; Iwamoto, Aikichi; Totsuka, Kyoichi; Kadota, Junichi; Sunakawa, Keisuke; Sato, Junko; Hanaki, Hideaki; Tsukamoto, Taiji; Kiyota, Hiroshi; Egawa, Shin; Tanaka, Kazushi; Arakawa, Soichi; Fujisawa, Masato; Kumon, Hiromi; Kobayashi, Kanao; Matsubara, Akio; Naito, Seiji; Tatsugami, Katsunori; Ito, Shin; Narita, Harunori; Kanokogi, Mototsugu; Sumii, Toru; Ito, Kenji; Hosobe, Takahide; Kawai, Shuichi; Kawano, Hiromi; Takayama, Kazuo; Yamaguchi, Takamasa; Endo, Katsuhisa; Yamauchi, Takamine; Maeda, Shinichi; Yoh, Mutsumasa; Horie, Masanobu; Ito, Masayasu; Chokyu, Hirofumi; Ihara, Hideari; Akiyama, Kikuo; Uno, Satoshi; Monden, Koichi; Kaji, Shinichi; Nishimura, Hirofumi; Kawahara, Motoshi; Sato, Takashi; Konishi, Takatoshi; Nishi, Shohei; Ishihara, Satoshi; Yoshioka, Masaru

    2013-08-01

    Neisseria gonorrhoeae is one of the most important pathogens causing sexually transmitted infection, and strains that are resistant to several antimicrobials are increasing. To investigate the trends of antimicrobial susceptibility among N. gonorrhoeae strains isolated from male patients with urethritis, a Japanese surveillance committee conducted the first nationwide surveillance. The urethral discharge was collected from male patients with urethritis at 51 medical facilities from April 2009 to October 2010. Of the 156 specimens, 83 N. gonorrhoeae strains were tested for susceptibility to 18 antimicrobial agents. The prevalence of β-lactamase-producing strains and chromosomally mediated resistant strains were 7.2 % and 16.5 %, respectively. None of the strains was resistant to ceftriaxone, but the minimum inhibitory concentration (MIC) of ceftriaxone for 7 strains (8.4 %) was 0.125 μg/ml. One strain was resistant to cefixime (MIC 0.5 μg/ml). The MICs of fluoroquinolones, such as ciprofloxacin, levofloxacin, and tosufloxacin, showed a bimodal distribution. The MIC of sitafloxacin was lower than those of the three fluoroquinolones listed here, and it was found that the antimicrobial activity of sitafloxacin was stronger than that of the fluoroquinolones. The MIC of azithromycin in 2 strains was 2 μg/ml, but no high-level resistance to macrolides was detected.

  14. Treatment of gonorrhoea in Auckland, New Zealand: marked variation in prescriber adherence to treatment guidelines.

    Science.gov (United States)

    Forster, Rose; Ng, Diana; Upton, Arlo; Franklin, Rick; Thomas, Mark

    2017-06-01

    The relentless emergence and spread of strains of Neisseria gonorrhoeae that are resistant to many antimicrobial agents has led to frequent changes in treatment guidelines, with a consequent risk that prescribers may not be aware of current guidelines. To determine the proportion of patients with gonorrhoea who were treated with a regimen consistent with the New Zealand Sexual Health Society (NZSHS) guidelines. We audited the treatment given to adult patients with laboratory-proven gonorrhoea in Auckland, New Zealand, during the first 6 months of 2015. Treatment compliant with the current NZSHS guidelines was administered in only 65% (458/706) episodes overall. Guideline-compliant treatment was much more likely to be prescribed for patients who presented to a sexual health clinic (89%) than for patients who presented to either a general practice or other community clinic (52%) or to a hospital (56%) (P Auckland region. Improved compliance with treatment guidelines, particularly in patients who present either to general practice or to hospitals, is necessary to maintain the efficacy of current treatment regimens. © 2017 Royal Australasian College of Physicians.

  15. Hospitalisations for pelvic inflammatory disease temporally related to a diagnosis of Chlamydia or gonorrhoea: a retrospective cohort study.

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    Joanne Reekie

    Full Text Available The presence and severity of pelvic inflammatory disease (PID symptoms are thought to vary by microbiological etiology but there is limited empirical evidence. We sought to estimate and compare the rates of hospitalisation for PID temporally related to diagnoses of gonorrhoea and chlamydia.All women, aged 15-45 years in the Australian state of New South Wales (NSW, with a diagnosis of chlamydia or gonorrhoea between 01/07/2000 and 31/12/2008 were followed by record linkage for up to one year after their chlamydia or gonorrhoea diagnosis for hospitalisations for PID. Standardised incidence ratios compared the incidence of PID hospitalisations to the age-equivalent NSW population.A total of 38,193 women had a chlamydia diagnosis, of which 483 were hospitalised for PID; incidence rate (IR 13.9 per 1000 person-years of follow-up (PYFU (95%CI 12.6-15.1. In contrast, 1015 had a gonorrhoea diagnosis, of which 45 were hospitalised for PID (IR 50.8 per 1000 PYFU, 95%CI 36.0-65.6. The annual incidence of PID hospitalisation temporally related to a chlamydia or gonorrhoea diagnosis was 27.0 (95%CI 24.4-29.8 and 96.6 (95%CI 64.7-138.8 times greater, respectively, than the age-equivalent NSW female population. Younger age, socio-economic disadvantage, having a diagnosis prior to 2005 and having a prior birth were also associated with being hospitalised for PID.Chlamydia and gonorrhoea are both associated with large increases in the risk of PID hospitalisation. Our data suggest the risk of PID hospitalisation is much higher for gonorrhoea than chlamydia; however, further research is needed to confirm this finding.

  16. Vaginal Lactobacilli Reduce Neisseria gonorrhoeae Viability through Multiple Strategies: An in Vitro Study

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    Claudio Foschi

    2017-12-01

    Full Text Available The emergence and spread of antimicrobial resistance in Neisseria gonorrhoeae (GC underline the need of “antibiotic-free” strategies for the control of gonorrhea. The aim of this study was to assess the anti-gonococcal activity of 14 vaginal Lactobacillus strains, belonging to different species (L. crispatus, L. gasseri, L. vaginalis, isolated from healthy pre-menopausal women. In particular, we performed “inhibition” experiments, evaluating the ability of both lactobacilli cells and culture supernatants in reducing GC viability, at two different contact times (7 and 60 min. First, we found that the acidic environment, associated to lactobacilli metabolism, is extremely effective in counteracting GC growth, in a pH- and time-dependent manner. Indeed, a complete abolishment of GC viability by lactobacilli supernatants was observed only for pH values < 4.0, even at short contact times. On the contrary, for higher pH values, no 100%-reduction of GC growth was reached at any contact time. Experiments with organic/inorganic acid solutions confirmed the strict correlation between the pH levels and the anti-gonococcal effect. In this context, the presence of lactate seemed to be crucial for the anti-gonococcal activity, especially for pH values in the range 4.4–5.3, indicating that the presence of H+ ions is necessary but not sufficient to kill gonococci. Moreover, experiments with buffered supernatants led to exclude a direct role in the GC killing by other bioactive molecules produced by lactobacilli. Second, we noticed that lactobacilli cells are able to reduce GC viability and to co-aggregate with gonococci. In this context, we demonstrated that released-surface components with biosurfactant properties, isolated from “highly-aggregating” lactobacilli, could affect GC viability. The antimicrobial potential of biosurfactants isolated from lactobacilli against pathogens has been largely investigated, but this is the first report about a

  17. Prevalence of Trichomonas vaginalis and Coinfection with Chlamydia trachomatis and Neisseria gonorrhoeae in the United States as Determined by the Aptima Trichomonas vaginalis Nucleic Acid Amplification Assay

    Science.gov (United States)

    Chapin, K.; Smith, J. S.; Aslanzadeh, J.; Snook, J.; Hill, C. S.; Gaydos, C. A.

    2012-01-01

    Our aim was to determine Trichomonas vaginalis prevalence using the Aptima Trichomonas vaginalis assay (ATV; Gen-Probe) and the prevalence of Chlamydia trachomatis and Neisseria gonorrhoeae coinfections in U.S. women undergoing screening for C. trachomatis/N. gonorrhoeae. Discarded urogenital samples from 7,593 women (18 to 89 years old) undergoing C. trachomatis/N. gonorrhoeae screening using the Aptima Combo 2 assay (Gen-Probe) in various clinical settings were tested with ATV. Overall, T. vaginalis, C. trachomatis, and N. gonorrhoeae prevalences were 8.7%, 6.7%, and 1.7%, respectively. T. vaginalis was more prevalent than C. trachomatis or N. gonorrhoeae in all age groups except the 18- to 19-year-old group. The highest T. vaginalis prevalence was in women ≥40 years old (>11%), while the highest C. trachomatis prevalence (9.2%) and N. gonorrhoeae prevalence (2.2%) were in women vaginalis, 0.61% for C. trachomatis/N. gonorrhoeae and N. gonorrhoeae/T. vaginalis, and 0.24% for C. trachomatis/N. gonorrhoeae/T. vaginalis and highest in women vaginalis prevalence differed by race/ethnicity, with the highest prevalence in black women (20.2%). T. vaginalis prevalence ranged from 5.4% in family planning clinics to 22.3% in jails. Multivariate analysis determined that ages of ≥40 years, black race, and patient locations were significantly associated with T. vaginalis infection. T. vaginalis is the most common sexually transmitted infection (STI) in women of >40 years, while C. trachomatis and N. gonorrhoeae prevalence is lowest in that age group. Higher T. vaginalis prevalence in women of >40 years is probably attributed to the reason for testing, i.e., symptomatic status versus routine screening in younger women. Coinfections were relatively low. High T. vaginalis prevalence in all age groups suggests that women screened for C. trachomatis/N. gonorrhoeae, whether asymptomatic or symptomatic, should be screened for T. vaginalis. PMID:22622447

  18. Performance of the Abbott RealTime CT/NG for detection of Chlamydia trachomatis and Neisseria gonorrhoeae.

    Science.gov (United States)

    Gaydos, C A; Cartwright, C P; Colaninno, P; Welsch, J; Holden, J; Ho, S Y; Webb, E M; Anderson, C; Bertuzis, R; Zhang, L; Miller, T; Leckie, G; Abravaya, K; Robinson, J

    2010-09-01

    A multicenter clinical study was conducted to evaluate the performance characteristics of the Abbott RealTime CT/NG assay, a multiplex real-time PCR assay, for simultaneous detection of Chlamydia trachomatis and Neisseria gonorrhoeae. The specimens were collected from a total of 3,832 male and female subjects at 16 geographically diverse sites. Specimens included male and female urine samples, male urethral swabs, female endocervical swabs, and self-collected and clinician-collected vaginal swabs. Specimens were tested with the automated Abbott RealTime CT/NG assay, Aptima Combo 2 assay (Gen-Probe), ProbeTec ET CT/GC assay (Becton Dickinson), and culture for N. gonorrhoeae. The Aptima Combo 2 assay, the ProbeTec assay, and the N. gonorrhoeae culture were used as the reference assays. For each subject, a patient infected status (PIS) was determined based on the combined results from the reference assays. The overall prevalence in female subjects was 8.9% for C. trachomatis and 3.8% for N. gonorrhoeae. The overall male prevalence was 18.2% for C. trachomatis and 16.7% for N. gonorrhoeae. The overall sensitivity and specificity of the Abbott RealTime CT/NG assay were 92.4% and 99.2% for C. trachomatis and 96.9% and 99.7% for N. gonorrhoeae, respectively. In comparison, the sensitivity and specificity, respectively, for the Aptima Combo 2 assay were 94.5% and 99.0% for C. trachomatis and 96.1% and 99.5% for N. gonorrhoeae, and those for the ProbeTec ET assay were 90.3% and 99.5% for C. trachomatis and 92.0% and 97.3% for N. gonorrhoeae in this study. The Abbott RealTime CT/NG assay offers C. trachomatis and N. gonorrhoeae dual detection with high sensitivity and specificity. The automated assay provides a useful alternative nucleic acid amplification assay for clinical laboratories and clinicians.

  19. Mycoplasma genitalium compared to chlamydia, gonorrhoea and trichomonas as an aetiological agent of urethritis in men attending STD clinics.

    Science.gov (United States)

    Gaydos, C; Maldeis, N E; Hardick, A; Hardick, J; Quinn, T C

    2009-10-01

    To investigate prevalence of Mycoplasma genitalium, Chlamydia trachomatis, Neisseria gonorrhoeae and Trichomonas vaginalis in men, frequency of co-infections, and association of organisms with urethritis in men. This was a cross-sectional study of 290 men (age range 19-34 years) attending Baltimore City STD clinics. M genitalium, C trachomatis, N gonorrhoeae and T vaginalis, during 2004 were detected using nucleic acid amplification tests (NAATs) (153 with urethritis and 137 without urethritis). Demographic characteristics and risk factors were ascertained. The overall prevalences of infection with C trachomatis, N gonorrhoeae, T vaginalis and M genitalium were 20.3%, 12.8%, 3.4% and 15.2%, respectively. Prevalences in men with urethritis were 32.7%, 24.2%, 5.2% and 22.2% for C trachomatis, N gonorrhoeae, T vaginalis and M genitalium, respectively. Percentages of co-infections were high. All men with N gonorrhoeae had urethritis. C trachomatis and M genitalium were found to be significantly associated with urethritis in univariate analysis and in multiple logistic regression analysis. The association of M genitalium with urethritis in this study provides confirmation of the importance of screening men for M genitalium as a cause of non-gonococcal urethritis and supports treatment considerations for urethritis for agents other than gonococci and chlamydia.

  20. Diagnosis of Neisseria gonorrhoeae among pregnant women by culture method and PCR on cppB gene

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    Jalal Mardaneh

    2013-11-01

    Full Text Available Background: Neisseria gonorrhoeae is a human obligate pathogen and the etiological agent of gonorrhea. Health irreparable complications resulting from gonorrhea disease occur mainly in pregnant women and neonates. Aim of this study was diagnosis of Neisseria gonorrhoeae among pregnant women with using culture and molecular method by amplification of cppB gene with PCR. Material and Methods: In this cross-sectional study, two endocervical swab specimens were obtained from 1100 pregnant women who referred to Shiraz Hospitals. Culture on nonselective and selective media and nucleic acid amplification test (NAAT were performed for detection of Neisseria gonorrhoeae cppB gene. Results: All endocervical swabs cultures on selective and nonselective media were negative for Neisseria gonorrhoeae. Among examined endocervical swabs, 13samples (1.18% were positive by nucleic acid amplification of Neisseria gonorrgoeae cppB gene. Conclusion: Negative results of culture and positive results of PCR in this study indicate that however culture is gold standard method for detection of Neisseria gonorrhoeae but due to bacterial autolysis, poor sampling techniques and improper specimen storage and transport, its value decline as compared with Nucleic acid amplification test (NAAT.

  1. Neisseria gonorrhoeae Sequence Typing for Antimicrobial Resistance, a Novel Antimicrobial Resistance Multilocus Typing Scheme for Tracking Global Dissemination of N. gonorrhoeae Strains.

    Science.gov (United States)

    Demczuk, W; Sidhu, S; Unemo, M; Whiley, D M; Allen, V G; Dillon, J R; Cole, M; Seah, C; Trembizki, E; Trees, D L; Kersh, E N; Abrams, A J; de Vries, H J C; van Dam, A P; Medina, I; Bharat, A; Mulvey, M R; Van Domselaar, G; Martin, I

    2017-05-01

    A curated Web-based user-friendly sequence typing tool based on antimicrobial resistance determinants in Neisseria gonorrhoeae was developed and is publicly accessible (https://ngstar.canada.ca). The N. gonorrhoeae Sequence Typing for Antimicrobial Resistance (NG-STAR) molecular typing scheme uses the DNA sequences of 7 genes ( penA , mtrR , porB , ponA , gyrA , parC , and 23S rRNA) associated with resistance to β-lactam antimicrobials, macrolides, or fluoroquinolones. NG-STAR uses the entire penA sequence, combining the historical nomenclature for penA types I to XXXVIII with novel nucleotide sequence designations; the full mtrR sequence and a portion of its promoter region; portions of ponA , porB , gyrA , and parC ; and 23S rRNA sequences. NG-STAR grouped 768 isolates into 139 sequence types (STs) ( n = 660) consisting of 29 clonal complexes (CCs) having a maximum of a single-locus variation, and 76 NG-STAR STs ( n = 109) were identified as unrelated singletons. NG-STAR had a high Simpson's diversity index value of 96.5% (95% confidence interval [CI] = 0.959 to 0.969). The most common STs were NG-STAR ST-90 ( n = 100; 13.0%), ST-42 and ST-91 ( n = 45; 5.9%), ST-64 ( n = 44; 5.72%), and ST-139 ( n = 42; 5.5%). Decreased susceptibility to azithromycin was associated with NG-STAR ST-58, ST-61, ST-64, ST-79, ST-91, and ST-139 ( n = 156; 92.3%); decreased susceptibility to cephalosporins was associated with NG-STAR ST-90, ST-91, and ST-97 ( n = 162; 94.2%); and ciprofloxacin resistance was associated with NG-STAR ST-26, ST-90, ST-91, ST-97, ST-150, and ST-158 ( n = 196; 98.0%). All isolates of NG-STAR ST-42, ST-43, ST-63, ST-81, and ST-160 ( n = 106) were susceptible to all four antimicrobials. The standardization of nomenclature associated with antimicrobial resistance determinants through an internationally available database will facilitate the monitoring of the global dissemination of antimicrobial-resistant N. gonorrhoeae strains. © Crown copyright 2017.

  2. A misleading false-negative result using Neisseria gonorrhoeae opa MGB multiplex PCR assay in patient's rectal sample due to partial mutations of the opa gene.

    Science.gov (United States)

    Vahidnia, Ali; van Empel, Pieter Jan; Costa, Sandra; Oud, Rob T N; van der Straaten, Tahar; Bliekendaal, Harry; Spaargaren, Joke

    2015-07-01

    A 53-year-old homosexual man presented at his general practitioner (GP) practice with a suspicion of sexually transmitted infection. Initial NAAT screening was performed for Chlamydia trachomatis and Neisseria gonorrhoeae. The patient was positive for Neisseria gonorrhoeae both for his urine and rectal sample. The subsequent confirmation test for Neisseria gonorrhoeae by a second laboratory was only confirmed for the urine sample and the rectal sample was negative. We report a case of a potential false-negative diagnosis of Neisseria gonorrhoeae due to mutations of DNA sequence in the probe region of opa-MGB assay of the rectal sample. The patient did not suffer any discomfort as diagnosis of Neisseria gonorrhoeae in his urine sample had already led to treatment by prescribing the patient with Ceftriaxone 500 mg IV dissolved in 1 ml lidocaine 2% and 4 mL saline. The patient also received a prescription for Azithromycin (2x500 mg).

  3. The Transcriptional Repressor, MtrR, of the mtrCDE Efflux Pump Operon of Neisseria gonorrhoeae Can Also Serve as an Activator of “off Target” Gene (glnE Expression

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    Paul J. T. Johnson

    2015-06-01

    Full Text Available MtrR is a well-characterized repressor of the Neisseria gonorrhoeae mtrCDE efflux pump operon. However, results from a previous transcriptional profiling study suggested that MtrR also represses or activates expression of at least sixty genes outside of the mtr locus. Evidence that MtrR can directly repress so-called “off target” genes has previously been reported; in particular, MtrR was shown to directly repress glnA, which encodes glutamine synthetase. In contrast, evidence for the ability of MtrR to directly activate expression of gonococcal genes has been lacking; herein, we provide such evidence. We now report that MtrR has the ability to directly activate expression of glnE, which encodes the dual functional adenyltransferase/deadenylase enzyme GlnE that modifies GlnA resulting in regulation of its role in glutamine biosynthesis. With its capacity to repress expression of glnA, the results presented herein emphasize the diverse and often opposing regulatory properties of MtrR that likely contributes to the overall physiology and metabolism of N. gonorrhoeae.

  4. Effectiveness of a group B outer membrane vesicle meningococcal vaccine against gonorrhoea in New Zealand: a retrospective case-control study.

    Science.gov (United States)

    Petousis-Harris, Helen; Paynter, Janine; Morgan, Jane; Saxton, Peter; McArdle, Barbara; Goodyear-Smith, Felicity; Black, Steven

    2017-09-30

    Gonorrhoea is a major global public health problem that is exacerbated by drug resistance. Effective vaccine development has been unsuccessful, but surveillance data suggest that outer membrane vesicle meningococcal group B vaccines affect the incidence of gonorrhoea. We assessed vaccine effectiveness of the outer membrane vesicle meningococcal B vaccine (MeNZB) against gonorrhoea in young adults aged 15-30 years in New Zealand. We did a retrospective case-control study of patients at sexual health clinics aged 15-30 years who were born between Jan 1, 1984, and Dec 31, 1998, eligible to receive MeNZB, and diagnosed with gonorrhoea or chlamydia, or both. Demographic data, sexual health clinic data, and National Immunisation Register data were linked via patients' unique personal identifier. For primary analysis, cases were confirmed by laboratory isolation or detection of Neisseria gonorrhoeae only from a clinical specimen, and controls were individuals with a positive chlamydia test only. We estimated odds ratios (ORs) comparing disease outcomes in vaccinated versus unvaccinated participants via multivariable logistic regression. Vaccine effectiveness was calculated as 100×(1-OR). 11 of 24 clinics nationally provided records. There were 14 730 cases and controls for analyses: 1241 incidences of gonorrhoea, 12 487 incidences of chlamydia, and 1002 incidences of co-infection. Vaccinated individuals were significantly less likely to be cases than controls (511 [41%] vs 6424 [51%]; adjusted OR 0·69 [95% CI 0·61-0·79]; pvaccine effectiveness of MeNZB against gonorrhoea after adjustment for ethnicity, deprivation, geographical area, and sex was 31% (95% CI 21-39). Exposure to MeNZB was associated with reduced rates of gonorrhoea diagnosis, the first time a vaccine has shown any protection against gonorrhoea. These results provide a proof of principle that can inform prospective vaccine development not only for gonorrhoea but also for meningococcal vaccines. GSK

  5. Identification and characterization of AckA-dependent protein acetylation in Neisseria gonorrhoeae.

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    Deborah M B Post

    Full Text Available Neisseria gonorrhoeae, the causative agent of gonorrhea, has a number of factors known to contribute to pathogenesis; however, a full understanding of these processes and their regulation has proven to be elusive. Post-translational modifications (PTMs of bacterial proteins are now recognized as one mechanism of protein regulation. In the present study, Western blot analyses, with an anti-acetyl-lysine antibody, indicated that a large number of gonococcal proteins are post-translationally modified. Previous work has shown that Nε-lysine acetylation can occur non-enzymatically with acetyl-phosphate (AcP as the acetyl donor. In the current study, an acetate kinase mutant (1291ackA, which accumulates AcP, was generated in N. gonorrhoeae. Broth cultures of N. gonorrhoeae 1291wt and 1291ackA were grown, proteins extracted and digested, and peptides containing acetylated-lysines (K-acetyl were affinity-enriched from both strains. Mass spectrometric analyses of these samples identified a total of 2686 unique acetylation sites. Label-free relative quantitation of the K-acetyl peptides derived from the ackA and wild-type (wt strains demonstrated that 109 acetylation sites had an ackA/wt ratio>2 and p-values <0.05 in at least 2/3 of the biological replicates and were designated as "AckA-dependent". Regulated K-acetyl sites were found in ribosomal proteins, central metabolism proteins, iron acquisition and regulation proteins, pilus assembly and regulation proteins, and a two-component response regulator. Since AckA is part of a metabolic pathway, comparative growth studies of the ackA mutant and wt strains were performed. The mutant showed a growth defect under aerobic conditions, an inability to grow anaerobically, and a defect in biofilm maturation. In conclusion, the current study identified AckA-dependent acetylation sites in N. gonorrhoeae and determined that these sites are found in a diverse group of proteins. This work lays the foundation for

  6. Escherichia coli and Neisseria gonorrhoeae UvrD helicase unwinds G4 DNA structures.

    Science.gov (United States)

    Shukla, Kaustubh; Thakur, Roshan Singh; Ganguli, Debayan; Rao, Desirazu Narasimha; Nagaraju, Ganesh

    2017-10-18

    G-quadruplex (G4) secondary structures have been implicated in various biological processes, including gene expression, DNA replication and telomere maintenance. However, unresolved G4 structures impede replication progression which can lead to the generation of DNA double-strand breaks and genome instability. Helicases have been shown to resolve G4 structures to facilitate faithful duplication of the genome. Escherichia coli UvrD (EcUvrD) helicase plays a crucial role in nucleotide excision repair, mismatch repair and in the regulation of homologous recombination. Here, we demonstrate a novel role of E. coli and Neisseria gonorrhoeae UvrD in resolving G4 tetraplexes. EcUvrD and N gonorrhoeae UvrD were proficient in unwinding previously characterized tetramolecular G4 structures. Notably, EcUvrD was equally efficient in resolving tetramolecular and bimolecular G4 DNA that were derived from the potential G4-forming sequences from the genome of E. coli Interestingly, in addition to resolving intermolecular G4 structures, EcUvrD was robust in unwinding intramolecular G4 structures. These data for the first time provide evidence for the role of UvrD in the resolution of G4 structures, which has implications for the in vivo role of UvrD helicase in G4 DNA resolution and genome maintenance. © 2017 The Author(s). Published by Portland Press Limited on behalf of the Biochemical Society.

  7. Cloning, nucleotide sequence and transcriptional analysis of the uvrA gene from Neisseria gonorrhoeae

    International Nuclear Information System (INIS)

    Black, C.G.; Fyfe, J.A.M.; Davies, J.K.

    1997-01-01

    A recombinant plasmid capable of restoring UV resistance to an Escherichia coli uvrA mutant was isolated from a genomic library of Neisseria gonorrhoeae. Sequence analysis revealed an open reading frame whose deduced amino acid sequence displayed significant similarity to those of the UvrA proteins of other bacterial species. A second open reading frame (ORF259) was identified upstream from, and in the opposite orientation to the gonococcal uvrA gene. Transcriptional fusions between portions of the gonococcal uvrA upstream region and a reporter gene were used to localise promoter activity in both E. coli and N. gonorrhoeae. The transcriptional starting points of uvrA and ORF259 were mapped in E. coli by primer extension analysis, and corresponding σ 70 promoters were identified. The arrangement of the uvrA-ORF259 intergenic region is similar to that of the gonococcal recA-aroD intergenic region. Both contain inverted copies of the 10 bp neisserial DNA uptake sequence situated between divergently transcribed genes. However, there is no evidence that either the uptake sequence or the proximity of the promoters influences expression of these genes. (author)

  8. Prevention of Ophthalmia Neonatorum Caused by Neisseria gonorrhoeae Using a Fatty Acid-Based Formulation

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    Colin P. Churchward

    2017-07-01

    Full Text Available Ophthalmia neonatorum, also called neonatal conjunctivitis, acquired during delivery can occur in the first 28 days of life. Commonly caused by the bacterial pathogen Neisseria gonorrhoeae, infection can lead to corneal scarring, perforation of the eye, and blindness. One approach that can be taken to prevent the disease is the use of an ophthalmic prophylaxis, which kills the bacteria on the surface of the eye shortly after birth. Current prophylaxes are based on antibiotic ointments. However, N. gonorrhoeae is resistant to many antibiotics and alternative treatments must be developed before the condition becomes untreatable. This study focused on developing a fatty acid-based prophylaxis. For this, 37 fatty acids or fatty acid derivatives were screened in vitro for fast antigonococcal activity. Seven candidates were identified as bactericidal at 1 mM. These seven were subjected to irritation testing using three separate methods: the bovine corneal opacity and permeability (BCOP test; the hen’s egg test—chorioallantoic membrane (HET-CAM; and the red blood cell (RBC lysis assay. The candidates were also tested in artificial tear fluid to determine whether they were effective in this environment. Four of the candidates remained effective. Among these, two lead candidates, monocaprin and myristoleic acid, displayed the best potential as active compounds in the development of a fatty acid-based prophylaxis for prevention of ophthalmia neonatorum.

  9. Structure and Function of Neisseria gonorrhoeae MtrF Illuminates a Class of Antimetabolite Efflux Pumps

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    Chih-Chia Su

    2015-04-01

    Full Text Available Neisseria gonorrhoeae is an obligate human pathogen and the causative agent of the sexually transmitted disease gonorrhea. The control of this disease has been compromised by the increasing proportion of infections due to antibiotic-resistant strains, which are growing at an alarming rate. N. gonorrhoeae MtrF is an integral membrane protein that belongs to the AbgT family of transporters for which no structural information is available. Here, we describe the crystal structure of MtrF, revealing a dimeric molecule with architecture distinct from all other families of transporters. MtrF is a bowl-shaped dimer with a solvent-filled basin extending from the cytoplasm to halfway across the membrane bilayer. Each subunit of the transporter contains nine transmembrane helices and two hairpins, posing a plausible pathway for substrate transport. A combination of the crystal structure and biochemical functional assays suggests that MtrF is an antibiotic efflux pump mediating bacterial resistance to sulfonamide antimetabolite drugs.

  10. Comparison of Neisseria gonorrhoeae MICs Obtained by Etest and Agar Dilution for Ceftriaxone, Cefpodoxime, Cefixime and Azithromycin.

    Science.gov (United States)

    Gose, Severin; Kong, Carol J; Lee, Yer; Samuel, Michael C; Bauer, Heidi M; Dixon, Paula; Soge, Olusegun O; Lei, John; Pandori, Mark

    2013-10-24

    We evaluated Neisseria gonorrhoeae Etest minimum inhibitory concentrations (MICs) relative to agar dilution MICs for 664 urethral isolates for ceftriaxone (CRO) and azithromycin (AZM), 351 isolates for cefpodoxime (CPD) and 315 isolates for cefixime (CFM). Etest accurately determined CPD, CFM and AZM MICs, but resulted in higher CRO MICs. © 2013. Published by Elsevier B.V. All rights reserved.

  11. Genital infections and reproductive complications associated with Trichomonas vaginalis, Neisseria gonorrhoeae, and Streptococcus agalactiae in women of Qom, central Iran

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    Mahmoud Nateghi Rostam

    2017-07-01

    Full Text Available Background: Trichomonas vaginalis (T.vaginalis and Neisseria gonorrhoeae (N.gonorrhoeae are two most common non-viral sexually transmitted infections in the world. No data are available regarding the epidemiology of genital infections in women of Qom, central Iran. Objective: Epidemiological investigation of sexually transmitted infections in genital specimens of women referred to the referral gynecology hospital in Qom, central Iran. Materials and Methods: Genital swab specimens were collected from women volunteers and used for identification of bacterial and protozoal infections by conventional microbial diagnostics, porA pseudo gene LightCycler® real-time PCR (for N.gonorrhoeae and ITS-PCR (for T.vaginalis. Results: Of 420 volunteers, 277 (65.9% had genital signs/symptoms, including 38.3% malodorous discharge, 37.9% dyspareunia, and 54.8% abdominal pain. Totally, 2 isolates of Streptococcus agalactiae were identified. Five specimens (1.2% in Thayer-Martin culture and 17 (4.1% in real-time PCR were identified as N.gonorrhoeae. Fifty-four specimens (12.9% in wet mount, 64 (15.2% in Dorset’s culture, and 81 (19.3% in ITS-PCR showed positive results for T.vaginalis. Five mixed infections of T.vaginalis+ N.gonorrhoeae were found. The risk of T.vaginalis infection was increased in women with low-birth-weight (p=0.00; OR=43.29, history of abortion (p=0.00; OR=91.84, and premature rupture of membranes (PROM (p=0.00; OR=21.75. The probability of finding nuclear leukocytes (p=0.00; OR=43.34 in vaginal smear was higher in T.vaginalis infection. Conclusion: The significant prevalence of trichomoniasis and gonorrhea emphasizes the need for accurate diagnosis and effective surveillance to prevent serious reproductive complications in women.

  12. Gonorrhea in Indonesia: High Prevalence of Asymptomatic Urogenital Gonorrhea but No Circulating Extended Spectrum Cephalosporins-Resistant Neisseria gonorrhoeae Strains in Jakarta, Yogyakarta, and Denpasar, Indonesia

    NARCIS (Netherlands)

    Hananta, I. Putu Yuda; van Dam, Alje P.; Bruisten, Sylvia Maria; Schim van der Loeff, Maarten Franciscus; Soebono, Hardyanto; de Vries, Henry John Christiaan

    2016-01-01

    Little is known about the epidemiology of asymptomatic urogenital gonorrhea and antimicrobial susceptibility of Neisseria gonorrhoeae (NG) strains circulating in Indonesia. We studied these issues in 3 large Indonesian cities. In 2014, participants were recruited from sexually transmitted infection

  13. The prevalence and epidemiology of plasmid-mediated penicillin and tetracycline resistance among Neisseria gonorrhoeae isolates in Guangzhou, China, 2002-2012.

    Science.gov (United States)

    Zheng, Heping; Wu, Xingzhong; Huang, Jinmei; Qin, Xiaolin; Xue, Yaohua; Zeng, Weiying; Lan, Yinyuan; Ou, Jiangli; Tang, Sanmei; Fang, Mingheng

    2015-10-09

    Gonococcal antimicrobial resistance is a global problem. Different resistance plasmids have emerged and spread among the isolates of Neisseria gonorrhoeae worldwide and in China. We conducted this study to monitor the plasmid-mediated penicillin and tetracycline resistance among N. gonorrhoeae isolates in Guangzhou from 2002 to 2012. Consecutive isolates of N. gonorrhoeae were collected from outpatients with gonorrhea attending the STD clinic in Guangdong Provincial Centre for Skin Diseases and STIs Control and Prevention. Penicillinase-producing N. gonorrhoeae (PPNG) isolates were analyzed by the paper acidometric method. Plasmid-mediated resistance to tetracycline in N. gonorrhoeae (TRNG) isolates was screened by the agar plate dilution method. Plasmid types were determined for TRNG and PPNG isolates using polymerase chain reaction (PCR). Minimum inhibitory concentrations (MICs) to penicillin and tetracycline were detected by the agar plate dilution. Of 1378 consecutive N. gonorrhoeae isolates, 429 PPNG and 639 TRNG isolates were identified. The prevalence of PPNG, TRNG, and PPNG/TRNG increased from 18.3 to 47.1 % (χ (2) = 31.57, p penicillin G and tetracycline persisted at high levels and the MIC90s were 32-fold higher than the resistant cutoff point over 11 years. The prevalence rates of penicillin- and tetracycline-resistant N. gonorrhoeae varied from 90.9 to 91.1 % and from 88.3 to 89.3 % during 2002 to 2012, respectively. Resistance to penicillin and tetracycline among N. gonorrhoeae isolates remained at high levels in Guangzhou. The Asian type PPNG continued to spread and Dutch type TRNG was still the dominant strain. The African type PPNG has emerged and is spreading rapidly.

  14. Risk factors for antimicrobial-resistant Neisseria gonorrhoeae and characteristics of patients infected with gonorrhea.

    Science.gov (United States)

    Fuertes de Vega, Irene; Baliu-Piqué, Carola; Bosch Mestres, Jordi; Vergara Gómez, Andrea; Vallés, Xavier; Alsina Gibert, Mercè

    2018-03-01

    There are very few data available regarding risk factors associated with antibiotic resistant-Neisseria gonorrhoeae. A study was conducted on 110 samples from 101 patients with gonococcal infection, in order to describe their characteristics and compare them with the antimicrobial susceptibility profile of their samples. An association was observed between resistant infections and heterosexual men, older age, concurrent sexually transmitted infection, and unsafe sexual behaviors. There is a need for improved data on the risk factors associated with antibiotic resistant gonococcal infection in order to identify risk groups, and to propose public health strategies to control this infection. Copyright © 2016 Elsevier España, S.L.U. and Sociedad Española de Enfermedades Infecciosas y Microbiología Clínica. All rights reserved.

  15. Definition of a virulence-related antigen of Neisseria gonorrhoeae with monoclonal antibodies and lectins.

    Science.gov (United States)

    Demarco de Hormaeche, R; Bundell, C; Chong, H; Taylor, D W; Wildy, P

    1986-03-01

    Variants of one strain of Neisseria gonorrhoeae, grown in vivo or in vitro, that have been previously shown to differ in infectivity, serum resistance, and capsule production were compared with use of monoclonal antibodies and lectins. Monoclonal antibodies to virulent gonococci recognized an antigenic site of the lipopolysaccharide (LPS) produced in large amounts by gonococci grown in vivo but present only in a small proportion of in vitro-grown gonococci. This antigen (C-LPS) was found in all 85 different gonococcal isolates studied but not among nonpathogenic neisseriae. It was shared by group B and C meningococci but not by groups A and D. Enzyme-linked immunosorbent assay and Western blot analysis showed that N-acetylglucosamine and N-acetylgalactosamine form part of the epitope. The C-LPS antigen was shown by immunofluorescence to be present on the surface of the gonococci and also free as slime. This antigen appears to confer resistance to killing by normal sera.

  16. Prevalence of Chlamydia Trachomatis, Neisseria Gonorrhoeae, and Trichomonas Vaginalis Infection in Chilean Adolescents and Young Adults.

    Science.gov (United States)

    Huneeus, Andrea; Schilling, Andrea; Fernandez, Mario I

    2018-02-01

    To determine the prevalence of Chlamydia trachomatis, Neisseria gonorrhoeae, and Trichomonas vaginalis infection in sexually active Chilean adolescents and young adults. A comparative analysis was performed between genders to identify demographic, clinical, and sexual behavior characteristics to predict the occurrence of C trachomatis. Analytical observational study. Santiago, Chile. Two hundred eighty-six sexually active volunteers aged 24 years or younger (171 female and 115 male); 82.9% (237/286) of them were classified as having high socioeconomic status. Confidential survey and self-collected samples (urine for men and vaginal swabs for women). Prevalence, demographic characteristics, symptoms, and sexual behavior characteristics. The prevalence rate of C trachomatis was 8.7% (10/115) in men and 8.8% (15/171) in women (P = .58). N gonorrhoeae was detected in 1 subject, whereas no T vaginalis cases were detected. In multivariate analysis, having some college education was protective (odds ratio [OR], 0.28; 95% confidence interval [CI], 0.09-0.89), whereas having a higher number of sexual partners was a risk factor (OR, 1.19; 95% CI, 1.1-1.3) for C trachomatis infection. The latter was also predicted by postcoital bleeding (OR, 4.6; 95% CI, 1.30-16.23) in the female model. C trachomatis infection rates were similar between both genders. Protective characteristics for the occurrence of this infection were having some college education, lower number of sexual partners, and if female, the absence of postcoital bleeding. This study highlights the importance of C trachomatis screening among the Chilean affluent population younger than 25 years. However, further studies are needed in a more diverse and representative sample to recommend universal screening in Chilean adolescents and young adults. Copyright © 2018 North American Society for Pediatric and Adolescent Gynecology. Published by Elsevier Inc. All rights reserved.

  17. Expression capable library for studies of Neisseria gonorrhoeae, version 1.0

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    Wachocki Susi

    2005-09-01

    Full Text Available Abstract Background The sexually transmitted disease, gonorrhea, is a serious health problem in developed as well as in developing countries, for which treatment continues to be a challenge. The recent completion of the genome sequence of the causative agent, Neisseria gonorrhoeae, opens up an entirely new set of approaches for studying this organism and the diseases it causes. Here, we describe the initial phases of the construction of an expression-capable clone set representing the protein-coding ORFs of the gonococcal genome using a recombination-based cloning system. Results The clone set thus far includes 1672 of the 2250 predicted ORFs of the N. gonorrhoeae genome, of which 1393 (83% are sequence-validated. Included in this set are 48 of the 61 ORFs of the gonococcal genetic island of strain MS11, not present in the sequenced genome of strain FA1090. L-arabinose-inducible glutathione-S-transferase (GST-fusions were constructed from random clones and each was shown to express a fusion protein of the predicted size following induction, demonstrating the use of the recombination cloning system. PCR amplicons of each ORF used in the cloning reactions were spotted onto glass slides to produce DNA microarrays representing 2035 genes of the gonococcal genome. Pilot experiments indicate that these arrays are suitable for the analysis of global gene expression in gonococci. Conclusion This archived set of Gateway® entry clones will facilitate high-throughput genomic and proteomic studies of gonococcal genes using a variety of expression and analysis systems. In addition, the DNA arrays produced will allow us to generate gene expression profiles of gonococci grown in a wide variety of conditions. Together, the resources produced in this work will facilitate experiments to dissect the molecular mechanisms of gonococcal pathogenesis on a global scale, and ultimately lead to the determination of the functions of unknown genes in the genome.

  18. Neisseria gonorrhoeae and extended-spectrum cephalosporins in California: surveillance and molecular detection of mosaic penA.

    Science.gov (United States)

    Gose, Severin; Nguyen, Duylinh; Lowenberg, Daniella; Samuel, Michael; Bauer, Heidi; Pandori, Mark

    2013-12-04

    The spread of Neisseria gonorrhoeae strains with mosaic penA alleles and reduced susceptibility to extended-spectrum cephalosporins is a major public health problem. While much work has been performed internationally, little is known about the genetics or molecular epidemiology of N. gonorrhoeae isolates with reduced susceptibility to extended-spectrum cephalosporins in the United States. The majority of N. gonorrhoeae infections are diagnosed without a live culture. Molecular tools capable of detecting markers of extended-spectrum cephalosporin resistance are needed. Urethral N. gonorrhoeae isolates were collected from 684 men at public health clinics in California in 2011. Minimum inhibitory concentrations (MICs) to ceftriaxone, cefixime, cefpodoxime and azithromycin were determined by Etest and categorized according to the U.S. Centers for Disease Control 2010 alert value breakpoints. 684 isolates were screened for mosaic penA alleles using real-time PCR (RTPCR) and 59 reactive isolates were subjected to DNA sequencing of their penA alleles and Neisseria gonorrhoeae multi-antigen sequence typing (NG-MAST). To increase the specificity of the screening RTPCR in detecting isolates with alert value extended-spectrum cephalosporin MICs, the primers were modified to selectively amplify the mosaic XXXIV penA allele. Three mosaic penA alleles were detected including two previously described alleles (XXXIV, XXXVIII) and one novel allele (LA-A). Of the 29 isolates with an alert value extended-spectrum cephalosporin MIC, all possessed the mosaic XXXIV penA allele and 18 were sequence type 1407, an internationally successful strain associated with multi-drug resistance. The modified RTPCR detected the mosaic XXXIV penA allele in urethral isolates and urine specimens and displayed no amplification of the other penA alleles detected in this study. N. gonorrhoeae isolates with mosaic penA alleles and reduced susceptibility to extended-spectrum cephalosporins are currently

  19. Prevalencia de infeccion por Neisseria Gonorrhoeae en trabajadoras sexuales atendidas en el Centro de Salud Antivenereo de Lima, 1995

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    José L Portilla C

    1997-01-01

    Full Text Available Entre Junio a Diciembre del año 1995, se estudiaron a 233 trabajadoras sexuales legales con control sanitario y 171 trabajadoras sexuales clandestinas que evaden dicho control sanitario, quienes fueron atendidas en el Centro de Salud Antivenéreo de Lima con la finalidad de investigar la frecuencia de las infecciones gonocócicas en estos grupos de población y detectar cepas de Neisseria gonorrhoeae productoras de beta-lactamasa. Se encontró diferencia significativa (p=0,014 entre las frecuencias de aislamiento del gonococo procedente de las trabajadores sexuales legales, 1,72% (4/233, en comparación con lo encontrado en las clandestinas, 7,02% (12/171. Del total de las cepas aisladas de N. gonorrhoeae, el 37,5% (6/16 resultaron ser productoras de beta-lactamasa.

  20. Experimental gonococcal infection in male volunteers: Cumulative experience with Neisseria gonorrhoeae strains FA1090 and MS11mkC

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    Marcia Metzgar Hobbs

    2011-05-01

    Full Text Available Experimental infection of male volunteers with Neisseria gonorrhoeae is safe and reproduces the clinical features of naturally acquired gonococcal urethritis. Human inoculation studies have helped define the natural history of experimental infection with two well-characterized strains of N. gonorrhoeae, FA1090 and MS11mkC. The human model has proved useful for testing the importance of putative gonococcal virulence factors for urethral infection in men. Studies with isogenic mutants have improved our understanding of the requirements for gonococcal LOS structures, pili, opacity proteins, IgA1 protease and the ability of infecting organisms to obtain iron from human transferrin and lactoferrin during uncomplicated urethritis. The model also presents opportunities to examine innate host immune responses that may be exploited or improved in development and testing of gonococcal vaccines. Here we review results to date with human experimental gonorrhea.

  1. Expansion of a urethritis-associated Neisseria meningitidis clade in the United States with concurrent acquisition of N. gonorrhoeae alleles.

    Science.gov (United States)

    Retchless, Adam C; Kretz, Cécilia B; Chang, How-Yi; Bazan, Jose A; Abrams, A Jeanine; Norris Turner, Abigail; Jenkins, Laurel T; Trees, David L; Tzeng, Yih-Ling; Stephens, David S; MacNeil, Jessica R; Wang, Xin

    2018-03-02

    Increased reports of Neisseria meningitidis urethritis in multiple U.S. cities during 2015 have been attributed to the emergence of a novel clade of nongroupable N. meningitidis within the ST-11 clonal complex, the "U.S. NmNG urethritis clade". Genetic recombination with N. gonorrhoeae has been proposed to enable efficient sexual transmission by this clade. To understand the evolutionary origin and diversification of the U.S. NmNG urethritis clade, whole-genome phylogenetic analysis was performed to identify its members among the N. meningitidis strain collection from the Centers for Disease Control and Prevention, including 209 urogenital and rectal N. meningitidis isolates submitted by U.S. public health departments in eleven states starting in 2015. The earliest representatives of the U.S. NmNG urethritis clade were identified from cases of invasive disease that occurred in 2013. Among 209 urogenital and rectal isolates submitted from January 2015 to September 2016, the clade accounted for 189/198 male urogenital isolates, 3/4 female urogenital isolates, and 1/7 rectal isolates. In total, members of the clade were isolated in thirteen states between 2013 and 2016, which evolved from a common ancestor that likely existed during 2011. The ancestor contained N. gonorrhoeae-like alleles in three regions of its genome, two of which may facilitate nitrite-dependent anaerobic growth during colonization of urogenital sites. Additional gonococcal-like alleles were acquired as the clade diversified. Notably, one isolate contained a sequence associated with azithromycin resistance in N. gonorrhoeae, but no other gonococcal antimicrobial resistance determinants were detected. Interspecies genetic recombination contributed to the early evolution and subsequent diversification of the U.S. NmNG urethritis clade. Ongoing acquisition of N. gonorrhoeae alleles by the U.S. NmNG urethritis clade may facilitate the expansion of its ecological niche while also increasing the

  2. Prevalence of Chlamydia trachomatis and Neisseria gonorrhoeae infection in adolescents in Northern Italy: an observational school-based study

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    Alberto Matteelli

    2016-02-01

    Full Text Available Abstract Background We carried out a study to evaluate the prevalence of Chlamydia trachomatis and Neisseria gonorrhoeae genital infections in school-based adolescents in Northern Italy. Methods Systematic screening for C. trachomatis and N. gonorrhoeae genital infection was performed in 13th grade students in the province of Brescia, an industrialized area in Northern Italy. Student filled in a questionnaire on sexual behaviour and provided a urine sample for microbiological testing. Results A total of 2,718 students (mean age: 18.4 years; 59.1 % females provided complete data (62.2 % of those eligible. Overall 2,059 students (75.8 % were sexually active (i.e. had had at least one partner, and the mean age at sexual debut was 16.1 years (SD: 1.4. Only 27.5 % of the sexually active students reported regular condom use during the previous 6 months, with higher frequency in males than in females (33.8 % vs 24.2 %. No case of N. gonorrhoeae infection was detected, while C. trachomatis was found in 36 adolescents, with a prevalence of 1.7 % (95 % CI: 1.2–2.4 among sexually active students, and no statistical difference between females and males (1.9 and 1.4 %, respectively. Inconsistent condom use (odds ratio, OR = 5.5 and having had more than one sexual partner during the previous 6 months (OR = 6.8 were associated with an increased risk of Chlamydia infection at multivariate analysis. Conclusion The prevalence of C. trachomatis infection among sexually active adolescents in Northern Italy was low, despite a high proportion of students who engage in risky sexual behaviour. No cases of N. gonorrhoeae infection were identified.

  3. AtlA Functions as a Peptidoglycan Lytic Transglycosylase in the Neisseria gonorrhoeae Type IV Secretion System▿

    OpenAIRE

    Kohler, Petra L.; Hamilton, Holly L.; Cloud-Hansen, Karen; Dillard, Joseph P.

    2007-01-01

    Type IV secretion systems require peptidoglycan lytic transglycosylases for efficient secretion, but the function of these enzymes is not clear. The type IV secretion system gene cluster of Neisseria gonorrhoeae encodes two peptidoglycan transglycosylase homologues. One, LtgX, is similar to peptidoglycan transglycosylases from other type IV secretion systems. The other, AtlA, is similar to endolysins from bacteriophages and is not similar to any described type IV secretion component. We chara...

  4. The second nationwide surveillance of the antimicrobial susceptibility of Neisseria gonorrhoeae from male urethritis in Japan, 2012-2013.

    Science.gov (United States)

    Hamasuna, Ryoichi; Yasuda, Mitsuru; Ishikawa, Kiyohito; Uehara, Shinya; Hayami, Hiroshi; Takahashi, Satoshi; Matsumoto, Tetsuro; Yamamoto, Shingo; Minamitani, Shinichi; Watanabe, Akira; Iwata, Satoshi; Kaku, Mitsuo; Kadota, Junichi; Sunakawa, Keisuke; Sato, Junko; Hanaki, Hideaki; Tsukamoto, Taiji; Kiyota, Hiroshi; Egawa, Shin; Tanaka, Kazushi; Arakawa, Soichi; Fujisawa, Masato; Kumon, Hiromi; Kobayashi, Kanao; Matsubara, Akio; Naito, Seiji; Kuroiwa, Kentaro; Hirayama, Hideo; Narita, Harunori; Hosobe, Takahide; Ito, Shin; Ito, Kenji; Kawai, Shuichi; Ito, Masayasu; Chokyu, Hirofumi; Matsumura, Masaru; Yoshioka, Masaru; Uno, Satoshi; Monden, Koichi; Takayama, Kazuo; Kaji, Shinichi; Kawahara, Motoshi; Sumii, Toru; Kadena, Hitoshi; Yamaguchi, Takamasa; Maeda, Shinichi; Nishi, Shohei; Nishimura, Hirofumi; Shirane, Takeshi; Yoh, Mutsumasa; Akiyama, Kikuo; Imai, Toshio; Kano, Motonori

    2015-05-01

    Worldwide, the most important concern in the treatment of sexually transmitted infections is the increase in antimicrobial resistant Neisseria gonorrhoeae strains including resistance to cephalosporins, penicillins, fluoroquinolones or macrolides. To investigate the trends of antimicrobial susceptibility among N. gonorrhoeae strains isolated from male patients with urethritis, a Japanese surveillance committee conducted the second nationwide surveillance study. Urethral discharge was collected from male patients with urethritis at 26 medical facilities from March 2012 to January 2013. Of the 151 specimens, 103 N. gonorrhoeae strains were tested for susceptibility to 20 antimicrobial agents. None of the strains was resistant to ceftriaxone, but the minimum inhibitory concentration (MIC) 90% of ceftriaxone increased to 0.125 μg/ml, and 11 (10.7%) strains were considered less susceptible with an MIC of 0.125 μg/ml. There were 11 strains resistant to cefixime, and the MICs of these strains were 0.5 μg/ml. The distributions of the MICs of fluoroquinolones, such as ciprofloxacin, levofloxacin and tosufloxacin, were bimodal. Sitafloxacin, a fluoroquinolone, showed strong activity against all strains, including strains resistant to other three fluoroquinolones, such as ciprofloxacin, levofloxacin and tosufloxacin. The azithromycin MICs in 2 strains were 1 μg/ml. Copyright © 2015 Japanese Society of Chemotherapy and The Japanese Association for Infectious Diseases. Published by Elsevier Ltd. All rights reserved.

  5. Genital Chlamydia trachomatis and Neisseria gonorrhoeae infections among women in sub-Saharan Africa: A structured review.

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    Dubbink, Jan Henk; Verweij, Stephan P; Struthers, Helen E; Ouburg, Sander; McIntyre, James A; Morré, Servaas A; Peters, Remco Ph

    2018-01-01

    Chlamydia trachomatis and Neisseria gonorrhoeae constitute major public health problems among women, but the burden of infection in sub-Saharan Africa is poorly documented. We conducted a structured review of the prevalence and incidence of genital, oral and anal C. trachomatis and N. gonorrhoeae infection in women in sub-Saharan Africa. We searched Medline, EMBASE and Web of Science over a 10-year period for studies on epidemiology of genital, oral and anal chlamydial infection and gonorrhoea in women in all countries of sub-Saharan Africa. We assessed geographic and demographic differences in prevalence and incidence of infection; weighted mean prevalence estimates were calculated with a random-effect model. A total of 102 study results were included, with data available for 24/49 of sub-Saharan countries. The weighted prevalence of chlamydial infection was lower among women in community-based studies (3.9%; 95% CI: 2.9-5.1%) than for women recruited at primary healthcare facilities (6.0%; 95% CI: 4.2-8.4%, p sub-Saharan Africa. Better control strategies are warranted to reduce the burden of infection and to prevent long-term complications of these infections.

  6. Determination of in vitro synergy for dual antimicrobial therapy against resistant Neisseria gonorrhoeae using Etest and agar dilution.

    Science.gov (United States)

    Wind, Carolien M; de Vries, Henry J C; van Dam, Alje P

    2015-03-01

    In response to antimicrobial resistance of Neisseria gonorrhoeae to last-resort extended-spectrum cephalosporins, combination therapy of azithromycin+ceftriaxone is now recommended. Dual therapy can be effective to treat monoresistant strains as well as multidrug-resistant strains, preferably employing the effect of in vitro synergy. As reports on in vitro synergy of azithromycin+ceftriaxone in N. gonorrhoeae are conflicting, in this study an evaluation of this combination was performed using a cross-wise Etest method and agar dilution. Synergy was defined as a fractional inhibitory concentration index (FICI) of ≤0.5. To identify other dual treatment options for gonorrhoea, in vitro synergy was evaluated for 65 dual antimicrobial combinations using Etest. Azithromycin, cefixime, ceftriaxone, colistin, ertapenem, fosfomycin, gentamicin, minocycline, moxifloxacin, rifampicin, spectinomycin and tigecycline were screened for synergy in all possible combinations. No synergy or antagonism was found for any of the 65 combinations. The geometric mean FICI ranged from 0.82 to 2.00. The mean FICI of azithromycin+ceftriaxone was 1.18 (Etest) and 0.55 (agar dilution). The difference between both methods did not result in a difference in interpretation of synergy. Ceftriaxone-resistant strain F89 was tested in all combinations and no synergy was found for any of them. Most importantly, the ceftriaxone minimum inhibitory concentration of F89 was not decreased below the breakpoint with any concentration of azithromycin. Copyright © 2014 Elsevier B.V. and the International Society of Chemotherapy. All rights reserved.

  7. Utility of pooled urine specimens for detection of Chlamydia trachomatis and Neisseria gonorrhoeae in men attending public sexually transmitted infection clinics in Mumbai, India, by PCR.

    Science.gov (United States)

    Lindan, Christina; Mathur, Meenakshi; Kumta, Sameer; Jerajani, Hermangi; Gogate, Alka; Schachter, Julius; Moncada, Jeanne

    2005-04-01

    Pooling urogenital specimens for the detection of Chlamydia trachomatis and Neisseria gonorrhoeae by nucleic acid amplification tests is an attractive alternative to individual testing. As pooling can reduce the costs of testing as well as labor, it has been advocated for use in resource-poor settings. However, it has neither been widely adopted nor evaluated for use in developing countries. We evaluated the practical use of pooling first-catch urine (FCU) specimens for the detection of C. trachomatis and N. gonorrhoeae from 690 men in Mumbai, India, by PCR. FCU, urethral smears, and swabs were collected from men seen at two sexually transmitted infection (STI) clinics. All laboratory testing was done at the Lokmanya Tilak General Hospital. Gram stain smears and culture isolation for N. gonorrhoeae were performed. Each FCU was tested individually and in pools using the Roche Amplicor PCR for C. trachomatis and N. gonorrhoeae with an internal control for inhibition. Specimen pools consisted of aliquots from five consecutively processed FCUs combined into an amplification tube. An optical density reading of > or =0.20 indicated a pool for which subsequent testing of individual samples was required. Prevalence by PCR on single specimens was 2.2% (15/690) for C. trachomatis and 5.4% (37/690) for N. gonorrhoeae. Compared to individual FCU results, pooling for C. trachomatis and N. gonorrhoeae had an overall sensitivity of 96.1% (50/52). Specificity was 96.5% (83/86) in that three pools required single testing that failed to identify a positive specimen. Pooling missed two positive specimens, decreased the inhibition rate, and saved 50.3% of reagent costs. In this resource-limited setting, the use of pooling to detect C. trachomatis and N. gonorrhoeae by PCR proved to be a simple, accurate, and cost-effective procedure compared to individual testing.

  8. Prevalence and treatment outcomes of routine Chlamydia trachomatis, Neisseria gonorrhoeae and Trichomonas vaginalis testing during antenatal care, Gaborone, Botswana.

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    Wynn, Adriane; Ramogola-Masire, Doreen; Gaolebale, Ponatshego; Moshashane, Neo; Sickboy, Ontiretse; Duque, Sofia; Williams, Elizabeth; Doherty, Klara; Klausner, Jeffrey D; Morroni, Chelsea

    2017-11-02

    Chlamydia trachomatis (CT) , Neisseria gonorrhoeae (NG) and Trichomonas vaginalis (TV) are curable, mostly asymptomatic, STIs that cause adverse maternal and perinatal outcomes. Most countries do not test for those infections during antenatal care. We implemented a CT, NG and TV testing and treatment programme in an antenatal clinic in Gaborone, Botswana. We conducted a prospective study in the antenatal clinic at Princess Marina Hospital in Gaborone, Botswana. We offered pregnant women who were 18 years or older and less than 35 weeks of gestation, CT, NG and TV testing using self-collected vaginal swabs. Testing was conducted using a GeneXpert® CT/NG and TV system. Those who tested positive were given directly observed antibiotic therapy and asked to return for a test of cure. We determined the prevalence of infections, uptake of treatment and proportion cured. The relationships between positive STI test and participant characteristics were assessed. We enrolled 400 pregnant women. Fifty-four (13.5%) tested positive for CT, NG and/or TV: 31 (8%) for CT, 5 (1.3%) for NG and 21 (5%) for TV. Among those who tested positive, 74% (40) received same-day, in person results and treatment. Among those who received delayed results (6), 67% (4) were treated. Statistical comparisons showed that being unmarried and HIV infected were positively association CT, NG and/or TV infection. Self-reported STI symptoms were not associated with CT, NG and/or TV infection. The prevalence of CT, NG and/or TV was high, particularly among women with HIV infection. Among women with CT, NG and/or TV infection, those who received same-day results were more likely to be treated than those who received delayed results. More research is needed on the costs and benefits of integrating highly sensitive and specific STI testing into antenatal care in Southern Africa. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No

  9. Overall Low Extended-Spectrum Cephalosporin Resistance but high Azithromycin Resistance in Neisseria gonorrhoeae in 24 European Countries, 2015.

    Science.gov (United States)

    Cole, Michelle J; Spiteri, Gianfranco; Jacobsson, Susanne; Woodford, Neil; Tripodo, Francesco; Amato-Gauci, Andrew J; Unemo, Magnus

    2017-09-11

    Surveillance of Neisseria gonorrhoeae antimicrobial susceptibility in Europe is performed through the European Gonococcal Antimicrobial Surveillance Programme (Euro-GASP), which additionally provides data to inform the European gonorrhoea treatment guideline; currently recommending ceftriaxone 500 mg plus azithromycin 2 g as first-line therapy. We present antimicrobial susceptibility data from 24 European countries in 2015, linked to epidemiological data of patients, and compare the results to Euro-GASP data from previous years. Antimicrobial susceptibility testing by MIC gradient strips or agar dilution methodology was performed on 2134 N. gonorrhoeae isolates and interpreted using EUCAST breakpoints. Patient variables associated with resistance were established using logistic regression to estimate odds ratios (ORs). In 2015, 1.7% of isolates were cefixime resistant compared to 2.0% in 2014. Ceftriaxone resistance was detected in only one (0.05%) isolate in 2015, compared with five (0.2%) in 2014. Azithromycin resistance was detected in 7.1% of isolates in 2015 (7.9% in 2014), and five (0.2%) isolates displayed high-level azithromycin resistance (MIC ≥ 256 mg/L) compared with one (0.05%) in 2014. Ciprofloxacin resistance remained high (49.4%, vs. 50.7% in 2014). Cefixime resistance significantly increased among heterosexual males (4.1% vs. 1.7% in 2014), which was mainly attributable to data from two countries with high cefixime resistance (~11%), however rates among men-who-have-sex-with-men (MSM) and females continued to decline to 0.5% and 1%, respectively. Azithromycin resistance in MSM and heterosexual males was higher (both 8.1%) than in females (4.9% vs. 2.2% in 2014). The association between azithromycin resistance and previous gonorrhoea infection, observed in 2014, continued in 2015 (OR 2.1, CI 1.2-3.5, p resistance and low overall resistance to ceftriaxone and cefixime. The low cephalosporin resistance may be attributable to the effectiveness

  10. Association of Neisseria gonorrhoeae Opa(CEA with dendritic cells suppresses their ability to elicit an HIV-1-specific T cell memory response.

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    Qigui Yu

    Full Text Available Infection with Neisseria gonorrhoeae (N. gonorrhoeae can trigger an intense local inflammatory response at the site of infection, yet there is little specific immune response or development of immune memory. Gonococcal surface epitopes are known to undergo antigenic variation; however, this is unlikely to explain the weak immune response to infection since individuals can be re-infected by the same serotype. Previous studies have demonstrated that the colony opacity-associated (Opa proteins on the N. gonorrhoeae surface can bind human carcinoembryonic antigen-related cellular adhesion molecule 1 (CEACAM1 on CD4⁺ T cells to suppress T cell activation and proliferation. Interesting in this regard, N. gonorrhoeae infection is associated with impaired HIV-1 (human immunodeficiency virus type 1-specific cytotoxic T-lymphocyte (CTL responses and with transient increases in plasma viremia in HIV-1-infected patients, suggesting that N. gonorrhoeae may also subvert immune responses to co-pathogens. Since dendritic cells (DCs are professional antigen presenting cells (APCs that play a key role in the induction of an adaptive immune response, we investigated the effects of N. gonorrhoeae Opa proteins on human DC activation and function. While morphological changes reminiscent of DC maturation were evident upon N. gonorrhoeae infection, we observed a marked downregulation of DC maturation marker CD83 when the gonococci expressing CEACAM1-specific Opa(CEA, but not other Opa variants. Consistent with a gonococcal-induced defect in maturation, Opa(CEA binding to CEACAM1 reduced the DCs' capacity to stimulate an allogeneic T cell proliferative response. Moreover, Opa(CEA-expressing N. gonorrhoeae showed the potential to impair DC-dependent development of specific adaptive immunity, since infection with Opa(CEA-positive gonococci suppressed the ability of DCs to stimulate HIV-1-specific memory CTL responses. These results reveal a novel mechanism to explain

  11. Bim and Bmf synergize to induce apoptosis in Neisseria gonorrhoeae infection.

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    Oliver Kepp

    2009-03-01

    Full Text Available Bcl-2 family proteins including the pro-apoptotic BH3-only proteins are central regulators of apoptotic cell death. Here we show by a focused siRNA miniscreen that the synergistic action of the BH3-only proteins Bim and Bmf is required for apoptosis induced by infection with Neisseria gonorrhoeae (Ngo. While Bim and Bmf were associated with the cytoskeleton of healthy cells, they both were released upon Ngo infection. Loss of Bim and Bmf from the cytoskeleton fraction required the activation of Jun-N-terminal kinase-1 (JNK-1, which in turn depended on Rac-1. Depletion and inhibition of Rac-1, JNK-1, Bim, or Bmf prevented the activation of Bak and Bax and the subsequent activation of caspases. Apoptosis could be reconstituted in Bim-depleted and Bmf-depleted cells by additional silencing of antiapoptotic Mcl-1 and Bcl-X(L, respectively. Our data indicate a synergistic role for both cytoskeletal-associated BH3-only proteins, Bim, and Bmf, in an apoptotic pathway leading to the clearance of Ngo-infected cells.

  12. Molecular Typing of Neisseria gonorrhoeae Isolates by Opa-Typing and Ribotyping in New Delhi, India

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    Pejvak Khaki

    2009-01-01

    Full Text Available Control and preventive measures for gonococcal infections are based on precise epidemiological characteristics of N. gonorrhoeae isolates. In the present study the potential utility of opa-typing and ribotyping for molecular epidemiological study of consecutive gonococcal strains was determined. Sixty gonococcal isolates were subjected to ribotyping with two restriction enzymes, AvaII and HincII, and opa-typing with TaqI and HpaII for epidemiological characterization of gonococcal population. Ribotyping with AvaII yielded 6 ribotype patterns while twelve RFLP patterns were observed with HincII. Opa-typing of the 60 isolates revealed a total 54 opa-types, which 48 were unique and 6 formed clusters. Fifty-two opa-types were observed with TaqI-digested PCR product while opa-typing with HpaII demonstrated 54 opa-types. The opa-types from isolates that were epidemiologically unrelated were distinct, whereas those from the sexual contacts were identical. The results showed that opa-typing is highly useful for characterizing gonococcal strains from sexual contacts and has more discriminatory than ribotyping that could differentiate between gonococci of the same ribotype. The technique even with a single restriction enzyme has a high level of discrimination (99.9% between epidemiologically unrelated isolates. In conclusion, the molecular methods such as opa-typing and ribotyping can be used for epidemiological characterization of gonococcal strains.

  13. A Systematic Review of Point of Care Testing for Chlamydia trachomatis, Neisseria gonorrhoeae, and Trichomonas vaginalis

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    Sasha Herbst de Cortina

    2016-01-01

    Full Text Available Objectives. Systematic review of point of care (POC diagnostic tests for sexually transmitted infections: Chlamydia trachomatis (CT, Neisseria gonorrhoeae (NG, and Trichomonas vaginalis (TV. Methods. Literature search on PubMed for articles from January 2010 to August 2015, including original research in English on POC diagnostics for sexually transmitted CT, NG, and/or TV. Results. We identified 33 publications with original research on POC diagnostics for CT, NG, and/or TV. Thirteen articles evaluated test performance, yielding at least one test for each infection with sensitivity and specificity ≥90%. Each infection also had currently available tests with sensitivities <60%. Three articles analyzed cost effectiveness, and five publications discussed acceptability and feasibility. POC testing was acceptable to both providers and patients and was also demonstrated to be cost effective. Fourteen proof of concept articles introduced new tests. Conclusions. Highly sensitive and specific POC tests are available for CT, NG, and TV, but improvement is possible. Future research should focus on acceptability, feasibility, and cost of POC testing. While pregnant women specifically have not been studied, the results available in nonpregnant populations are encouraging for the ability to test and treat women in antenatal care to prevent adverse pregnancy and neonatal outcomes.

  14. Arginine- and Polyamine-Induced Lactic Acid Resistance in Neisseria gonorrhoeae.

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    Zheng Gong

    Full Text Available Microbe-derived lactic acid protects women from pathogens in their genital tract. The purpose of this study was to determine lactic acid susceptibility of Neisseria gonorrhoeae, and identify potential acid resistance mechanisms present in this pathogen. Tested in vitro, lactic acid killed all 10 gonococcal strains analyzed in a low pH-dependent manner. Full inactivation occurred at pH 4.5. At low pH, lactic acid treatment resulted in the entry of the DNA-binding fluorochrome propidium iodide into the microbial cells, suggesting that hydrogen ions from lactic acid compromise the integrity of the bacterial cell wall/membrane. Most likely, hydrogen ions also inactivate intracellular proteins since arginine rendered significant protection against lactic acid presumably through action of the gonococcal arginine decarboxylase, an enzyme located in the bacterial cytoplasm. Surprisingly, arginine also lessened lactic acid-mediated cell wall/membrane disruption. This effect is probably mediated by agmatine, a triamine product of arginine decarboxylase, since agmatine demonstrated a stronger protective effect on GC than arginine at equal molar concentration. In addition to agmatine, diamines cadaverine and putrescine, which are generated by bacterial vaginosis-associated microbes, also induced significant resistance to lactic acid-mediated GC killing and cell wall/membrane disruption. These findings suggest that the arginine-rich semen protects gonococci through both neutralization-dependent and independent mechanisms, whereas polyamine-induced acid resistance contributes to the increased risk of gonorrhea in women with bacterial vaginosis.

  15. Point-of-care testing for chlamydia and gonorrhoea: implications for clinical practice.

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    Lisa Natoli

    Full Text Available Point-of-care (POC testing for chlamydia (CT and gonorrhoea (NG offers a new approach to the diagnosis and management of these sexually transmitted infections (STIs in remote Australian communities and other similar settings. Diagnosis of STIs in remote communities is typically symptom driven, and for those who are asymptomatic, treatment is generally delayed until specimens can be transported to the reference laboratory, results returned and the patient recalled. The objective of this study was to explore the clinical implications of using CT/NG POC tests in routine clinical care in remote settings.In-depth qualitative interviews were conducted with a purposively selected group of 18 key informants with a range of sexual health and laboratory expertise.Participants highlighted the potential impact POC testing would have on different stages of the current STI management pathway in remote Aboriginal communities and how the pathway would change. They identified implications for offering a POC test, specimen collection, conducting the POC test, syndromic management of STIs, pelvic inflammatory disease diagnosis and management, interpretation and delivery of POC results, provision of treatment, contact tracing, management of client flow and wait time, and re-testing at 3 months after infection.The introduction of POC testing to improve STI service delivery requires careful consideration of both its advantages and limitations. The findings of this study will inform protocols for the implementation of CT/NG POC testing, and also STI testing and management guidelines.

  16. Point-of-Care Testing for Chlamydia and Gonorrhoea: Implications for Clinical Practice

    Science.gov (United States)

    Natoli, Lisa; Maher, Lisa; Shephard, Mark; Hengel, Belinda; Tangey, Annie; Badman, Steven G.; Ward, James; Guy, Rebecca J.

    2014-01-01

    Objectives Point-of-care (POC) testing for chlamydia (CT) and gonorrhoea (NG) offers a new approach to the diagnosis and management of these sexually transmitted infections (STIs) in remote Australian communities and other similar settings. Diagnosis of STIs in remote communities is typically symptom driven, and for those who are asymptomatic, treatment is generally delayed until specimens can be transported to the reference laboratory, results returned and the patient recalled. The objective of this study was to explore the clinical implications of using CT/NG POC tests in routine clinical care in remote settings. Methods In-depth qualitative interviews were conducted with a purposively selected group of 18 key informants with a range of sexual health and laboratory expertise. Results Participants highlighted the potential impact POC testing would have on different stages of the current STI management pathway in remote Aboriginal communities and how the pathway would change. They identified implications for offering a POC test, specimen collection, conducting the POC test, syndromic management of STIs, pelvic inflammatory disease diagnosis and management, interpretation and delivery of POC results, provision of treatment, contact tracing, management of client flow and wait time, and re-testing at 3 months after infection. Conclusions The introduction of POC testing to improve STI service delivery requires careful consideration of both its advantages and limitations. The findings of this study will inform protocols for the implementation of CT/NG POC testing, and also STI testing and management guidelines. PMID:24956111

  17. The prevalences of Neisseria gonorrhoeae and Chlamydia trachomatis infections among female sex workers in China

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    Chen Xiang-Sheng

    2013-02-01

    Full Text Available Abstract Background Sexually transmitted infections (STIs have become a major public health problem among female sex workers (FSWs in China. There have been many studies on prevalences of HIV and syphilis but the data about Neisseria gonorrhoeae (NG and Chlamydia trachomatis (CT infections are limited in this population in China. Methods A cross-sectional study was performed among FSWs recruited from different types of venues in 8 cities in China. An interview with questionnaire was conducted, followed by collection of a blood and cervical swab specimens for tests of HIV, syphilis, NG and CT infections. Results A total of 3,099 FSWs were included in the study. The overall prevalence rates of HIV, syphilis, NG and CT were 0.26%, 6.45%, 5.91% and 17.30%, respectively. Being a FSW from low-tier venue (adjusted odds ratios [AOR]=1.39 had higher risk and being age of ≥ 21 years (AOR=0.60 for 21–25 years; AOR=0.29 for 26–30 years; AOR=0.35 for 31 years or above had lower risk for CT infection; and having CT infection was significantly associated with NG infection. Conclusions The high STI prevalence rates found among FSWs, especially among FSWs in low-tier sex work venues, suggest that the comprehensive prevention and control programs including not only behavioral interventions but also screening and medical care are needed to meet the needs of this population.

  18. Molecular Typing of Neisseria gonorrhoeae Isolates by Opa-Typing and Ribotyping in New Delhi, India

    Science.gov (United States)

    Khaki, Pejvak; Bhalla, Preena; Fayaz, Ahmad Mir; Moradi Bidhendi, Sohiela; Esmailzadeh, Majid; Sharma, Pawan

    2009-01-01

    Control and preventive measures for gonococcal infections are based on precise epidemiological characteristics of N. gonorrhoeae isolates. In the present study the potential utility of opa-typing and ribotyping for molecular epidemiological study of consecutive gonococcal strains was determined. Sixty gonococcal isolates were subjected to ribotyping with two restriction enzymes, AvaII and HincII, and opa-typing with TaqI and HpaII for epidemiological characterization of gonococcal population. Ribotyping with AvaII yielded 6 ribotype patterns while twelve RFLP patterns were observed with HincII. Opa-typing of the 60 isolates revealed a total 54 opa-types, which 48 were unique and 6 formed clusters. Fifty-two opa-types were observed with TaqI-digested PCR product while opa-typing with HpaII demonstrated 54 opa-types. The opa-types from isolates that were epidemiologically unrelated were distinct, whereas those from the sexual contacts were identical. The results showed that opa-typing is highly useful for characterizing gonococcal strains from sexual contacts and has more discriminatory than ribotyping that could differentiate between gonococci of the same ribotype. The technique even with a single restriction enzyme has a high level of discrimination (99.9%) between epidemiologically unrelated isolates. In conclusion, the molecular methods such as opa-typing and ribotyping can be used for epidemiological characterization of gonococcal strains. PMID:20016674

  19. Evaluation of sexual history-based screening of anatomic sites for chlamydia trachomatis and neisseria gonorrhoeae infection in men having sex with men in routine practice

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    Jansen Casper L

    2011-07-01

    Full Text Available Abstract Background Sexually transmitted infection (STI screening programmes are implemented in many countries to decrease burden of STI and to improve sexual health. Screening for Chlamydia trachomatis and Neisseria gonorrhoeae has a prominent role in these protocols. Most of the screening programmes concerning men having sex with men (MSM are based on opportunistic urethral testing. In The Netherlands, a history-based approach is used. The aim of this study is to evaluate the protocol of screening anatomic sites for C. trachomatis and N. gonorrhoeae infection based on sexual history in MSM in routine practice in The Netherlands. Methods All MSM visiting the clinic for STI in The Hague are routinely asked about their sexual practice during consulting. As per protocol, tests for urogenital, oropharyngeal and anorectal infection are obtained based on reported site(s of sexual contact. All consultations are entered into a database as part of the national STI monitoring system. Data of an 18 months period were retrieved from this database and analysed. Results A total of 1455 consultations in MSM were registered during the study period. The prevalence of C. trachomatis and N. gonorrhoeae per anatomic site was: urethral infection 4.0% respectively and 2.8%, oropharynx 1.5% and 4.2%, and anorectum 8.2% and 6.0%. The majority of chlamydia cases (72% involved a single anatomic site, which was especially manifest for anorectal infections (79%, while 42% of gonorrhoea cases were single site. Twenty-six percent of MSM with anorectal chlamydia and 17% with anorectal gonorrhoea reported symptoms of proctitis; none of the oropharyngeal infections were symptomatic. Most cases of anorectal infection (83% and oropharyngeal infection (100% would have remained undiagnosed with a symptom-based protocol. Conclusions The current strategy of sexual-history based screening of multiple anatomic sites for chlamydia and gonorrhoea in MSM is a useful and valid guideline

  20. Prevalencia de infecciones por Chlamydia trachomatis y Neisseria gonorrhoeae en adolescentes de colegios de la provincia de Sabana Centro, Cundinamarca, Colombia

    OpenAIRE

    María Cecilia Paredes; Yenny Milena Gómez; Ana Marcela Torres; Marcela Fernández; María Belén Tovar

    2015-01-01

    Introducción. Las infecciones por Chlamydia trachomatis y Neisseria gonorrhoeae son las dos infecciones bacterianas de transmisión sexual más frecuentes en el mundo, principalmente en menores de 25 años, en cuya salud sexual, reproductiva y materno-infantil producen secuelas. Objetivo. Estimar la prevalencia de las infecciones por C. trachomatis y N. gonorrhoeae entre adolescentes en colegios de la provincia de Sabana Centro, Cundinamarca, Colombia. Materiales y métodos. Se hizo un estu...

  1. Quality assurance for antimicrobial susceptibility testing of Neisseria gonorrhoeae in Latin American and Caribbean countries, 2013-2015.

    Science.gov (United States)

    Sawatzky, Pam; Martin, Irene; Galarza, Patricia; Carvallo, Marıa Elena Trigoso; Araya Rodriguez, Pamela; Cruz, Olga Marina Sanabria; Hernandez, Alina Llop; Martinez, Mario Fabian; Borthagaray, Graciela; Payares, Daisy; Moreno, José E; Chiappe, Marina; Corredor, Aura Helena; Thakur, Sidharath Dev; Dillon, Jo-Anne R

    2018-04-19

    A Neisseria gonorrhoeae antimicrobial susceptibility quality control comparison programme was re-established in Latin America and the Caribbean to ensure antimicrobial susceptibility data produced from the region are comparable nationally and internationally. Three panels, consisting of N. gonorrhoeae isolates comprising reference strains and other characterised isolates were sent to 11 participating laboratories between 2013 and 2015. Antimicrobial susceptibilities for these isolates were determined using agar dilution, Etest or disc diffusion methods. Modal minimum inhibitory concentrations (MICs) for each panel isolate/antibiotic combination were calculated. The guidelines of the Clinical and Laboratory Standards Institute were used for interpretations of antimicrobial susceptibility. The agreement of MICs with the modal MICs was determined for each of the participating laboratories as well as for each of the antibiotics tested. Five of 11 laboratories that participated in at least one panel had an overall average agreement between participants' MIC results and modal MICs of >90%. For other laboratories, agreements ranged from 60.0% to 82.4%. The proportion of agreement between interpretations for all the antibiotics, except penicillin and tetracycline, was >90%. The percentages of agreement between MIC results and their modes for erythromycin, spectinomycin, cefixime and azithromycin were >90%. Tetracycline, ceftriaxone and ciprofloxacin agreement ranged from 84.5% to 89.1%, while penicillin had 78.8% agreement between MICs and modal MICs. The participating laboratories had acceptable results, similar to other international quality assurance programmes. It is important to ensure continuation of the International Gonococcal Antimicrobial Susceptibility Quality Control Comparison Programme to ensure that participants can identify and correct any problems in antimicrobial susceptibility testing for N. gonorrhoeae as they arise and continue to generate reproducible

  2. Detection of T. vaginalis,M. hominis,M. genitalium, C. trachomatis, N. gonorrhoeae and U. urealyticum using Multiplex PCR

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    Tamara Brunelli

    2013-03-01

    Full Text Available Intoduction. The sexually transmitted diseases include a large group of infections affecting both the sexes. In this study we evaluated the prevalence of Trichomonas vaginalis, Mycoplasma hominis, Mycoplasma genitalium, Chlamydia trachomatis, Neisseria gonorrhoeae and Ureaplasma urealyticum in the Prato area during the period September 2010 – July 2011. Methods.We analysed different kind of samples (urine, endocervical swabs, urethral swabs, seminal fluids from hospitalized patients or referred to the Prato clinic subjects.The DNA was obtained using EZ1-DNA extraction kit and EZ1 instrument.The DNA was then amplified using the Seeplex STD6 kit (Seegene, Korea, identifying multiple pathogens simultaneously (T. vaginalis, M. hominis, M. genitalium, C. trachomatis, N. gonorrhoeae e U. urealyticum. The revelation was performed by electrophoresis on microchip (instrument Multina, Shimadzu, Japan. Results. 1136 samples from Italian and foreign patients were examined: 876 were endocervical swabs (77%, 103 urethral swabs (9%, 103 seminal fluids (9%, and 54 urines (5%. The number of females was higher than males [894 (78.7% vs 242 (21.3%]; the mean age of females was 37.0±11.6 years, whereas that of males was 41.5 ±12.63 years.The prevalence of urogenital pathogens was: 15 positive samples for T. vaginalis (1.3%, 56 for M. hominis (4.9%, 13 for M. genitalium (1.1%, 28 for C. trachomatis (2.5%, 8 for N. gonorrhoeae (0.7% and 87 for U. urealyticum (7.7%.Among all positive, 25 subjects were positive for more than one pathogen and in particular: one was positive for the presence of 4 pathogens, five presented 3 pathogens simultaneously and the remaining nineteen for 2 pathogens. Conclusions. This study provides data on the prevalence of sexually transmitted diseases in the hospital of Prato.

  3. Estimating the fitness cost and benefit of cefixime resistance in Neisseria gonorrhoeae to inform prescription policy: A modelling study.

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    Lilith K Whittles

    2017-10-01

    Full Text Available Gonorrhoea is one of the most common bacterial sexually transmitted infections in England. Over 41,000 cases were recorded in 2015, more than half of which occurred in men who have sex with men (MSM. As the bacterium has developed resistance to each first-line antibiotic in turn, we need an improved understanding of fitness benefits and costs of antibiotic resistance to inform control policy and planning. Cefixime was recommended as a single-dose treatment for gonorrhoea from 2005 to 2010, during which time resistance increased, and subsequently declined.We developed a stochastic compartmental model representing the natural history and transmission of cefixime-sensitive and cefixime-resistant strains of Neisseria gonorrhoeae in MSM in England, which was applied to data on diagnoses and prescriptions between 2008 and 2015. We estimated that asymptomatic carriers play a crucial role in overall transmission dynamics, with 37% (95% credible interval CrI 24%-52% of infections remaining asymptomatic and untreated, accounting for 89% (95% CrI 82%-93% of onward transmission. The fitness cost of cefixime resistance in the absence of cefixime usage was estimated to be such that the number of secondary infections caused by resistant strains is only about half as much as for the susceptible strains, which is insufficient to maintain persistence. However, we estimated that treatment of cefixime-resistant strains with cefixime was unsuccessful in 83% (95% CrI 53%-99% of cases, representing a fitness benefit of resistance. This benefit was large enough to counterbalance the fitness cost when 31% (95% CrI 26%-36% of cases were treated with cefixime, and when more than 55% (95% CrI 44%-66% of cases were treated with cefixime, the resistant strain had a net fitness advantage over the susceptible strain. Limitations include sparse data leading to large intervals on key model parameters and necessary assumptions in the modelling of a complex epidemiological process

  4. Apoptosis related genes expressed in cultured Fallopian tube epithelial cells infected in vitro with Neisseria gonorrhoeae

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    PAZ A REYES

    2007-01-01

    Full Text Available Background: Infection of the Fallopian tubes (FT by Neisseria gonorrhoeae (Ngo can lead to acute salpingitis, an inflammatory condition resulting in damage primarily to the ciliated cells, with loss of ciliary activity and sloughing of the cells from the epithelium. Recently, we have shown that Ngo infection induced apoptosis in FT epithelium cells by a TNF-alpha dependent mechanism that could contribute to the cell and tissue damage observed in gonococcal salpingitis. Aim: To investigate the apoptosis-related genes expressed during apoptosis induction in cultured FT epithelial cells infected in vitro by Ngo. Materials and Methods: In the current study, we used cDNA macroarrays and real time PCR to identify and determine the expression levels of apoptosis related genes during the in vitro gonococci infection of FT epithelial cells. Results: Significant apoptosis was induced following infection with Ngo. Macroarray analysis identified the expression of multiple genes of the TNF receptor family (TNFRSF1B, -4, -6, -10A, -10B and -10D and the Bcl-2 family (BAK1, BAX, BLK, HRK and MCL-1 without differences between controls and infected cells. This lack of difference was confirmed by RT-PCR of BAX, Bcl-2, TNFRS1A (TNFR-I and TNFRSF1B (TNFR-II. Conclusion: Several genes related to apoptosis are expressed in primary cultures of epithelial cells of the human Fallopian tube. Infection with Ngo induces apoptosis without changes in the pattern of gene expression of several apoptosis-related genes. Results strongly suggest that Ngo regulates apoptosis in the FT by post-transcriptional mechanisms that need to be further addressed

  5. Deep sequencing-based analysis of the anaerobic stimulon in Neisseria gonorrhoeae

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    Clark Virginia L

    2011-01-01

    Full Text Available Abstract Background Maintenance of an anaerobic denitrification system in the obligate human pathogen, Neisseria gonorrhoeae, suggests that an anaerobic lifestyle may be important during the course of infection. Furthermore, mounting evidence suggests that reduction of host-produced nitric oxide has several immunomodulary effects on the host. However, at this point there have been no studies analyzing the complete gonococcal transcriptome response to anaerobiosis. Here we performed deep sequencing to compare the gonococcal transcriptomes of aerobically and anaerobically grown cells. Using the information derived from this sequencing, we discuss the implications of the robust transcriptional response to anaerobic growth. Results We determined that 198 chromosomal genes were differentially expressed (~10% of the genome in response to anaerobic conditions. We also observed a large induction of genes encoded within the cryptic plasmid, pJD1. Validation of RNA-seq data using translational-lacZ fusions or RT-PCR demonstrated the RNA-seq results to be very reproducible. Surprisingly, many genes of prophage origin were induced anaerobically, as well as several transcriptional regulators previously unknown to be involved in anaerobic growth. We also confirmed expression and regulation of a small RNA, likely a functional equivalent of fnrS in the Enterobacteriaceae family. We also determined that many genes found to be responsive to anaerobiosis have also been shown to be responsive to iron and/or oxidative stress. Conclusions Gonococci will be subject to many forms of environmental stress, including oxygen-limitation, during the course of infection. Here we determined that the anaerobic stimulon in gonococci was larger than previous studies would suggest. Many new targets for future research have been uncovered, and the results derived from this study may have helped to elucidate factors or mechanisms of virulence that may have otherwise been overlooked.

  6. Neisseria gonorrhoeae molecular typing for understanding sexual networks and antimicrobial resistance transmission: A systematic review.

    Science.gov (United States)

    Town, Katy; Bolt, Hikaru; Croxford, Sara; Cole, Michelle; Harris, Simon; Field, Nigel; Hughes, Gwenda

    2018-06-01

    Neisseria gonorrhoeae (NG) is a significant global public health concern due to rising diagnoses rates and antimicrobial resistance. Molecular combined with epidemiological data have been used to understand the distribution and spread of NG, as well as relationships between cases in sexual networks, but the public health value gained from these studies is unclear. We conducted a systematic review to examine how molecular epidemiological studies have informed understanding of sexual networks and NG transmission, and subsequent public health interventions. Five research databases were systematically searched up to 31st March 2017 for studies that used sequence-based DNA typing methods, including whole genome sequencing, and linked molecular data to patient-level epidemiological data. Data were extracted and summarised to identify common themes. Of the 49 studies included, 82% used NG Multi-antigen Sequence Typing. Gender and sexual orientation were commonly used to characterise sexual networks that were inferred using molecular clusters; clusters predominantly of one patient group often contained a small number of isolates from other patient groups. Suggested public health applications included using these data to target interventions at specific populations, confirm outbreaks, and inform partner management, but these were mainly untested. Combining molecular and epidemiological data has provided insight into sexual mixing patterns, and dissemination of NG, but few studies have applied these findings to design or evaluate public health interventions. Future studies should focus on the application of molecular epidemiology in public health practice to provide evidence for how to prevent and control NG. Copyright © 2018 The Authors. Published by Elsevier Ltd.. All rights reserved.

  7. Comparing the disk-diffusion and agar dilution tests for Neisseria gonorrhoeae antimicrobial susceptibility testing

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    Hsi Liu

    2016-11-01

    Full Text Available Abstract Background We assessed the validity of testing for antimicrobial susceptibility of clinical and mutant Neisseria gonorrhoeae (GC isolates by disk diffusion in comparison to agar dilution, and Etest® (bioMerieux, France, respectively, for three third generation extended spectrum cephalosporins (ESC: ceftriaxone (CRO, cefixime (CFX, and cefpodoxime (CPD. Methods One hundred and five clinical isolates and ten laboratory-mutants were tested following Clinical Laboratory Standard Institute (CLSI and manufacturer’s standards for each of the three methods. The measured diameters by the disk diffusion method were tested for correlation with the MIC values by agar dilution. In addition, comparisons with the Etest® were made. Categorical results for concordance, based on standard CLSI cutoffs, between the disk diffusion and the other two methods, respectively, were tested using the Chi-square statistics. Reproducibility was tested for CFX across a 6-month interval by repeated disk tests. Results Across all 115 specimens, the disk diffusion tests produced good categorical agreements, exhibiting concordance of 93.1%, 92.1%, and 90.4% with agar dilution and 93.0%, 92.1%, and 90.4% with Etest®, for CRO, CFX, and CPD, respectively. Pearson correlations between disk-diffusion diameters and agar dilution MIC’s were -0.59, -0.67, and -0.81 for CRO, CFX, and CPD, respectively. The correlations between disk diffusion and Etest® were -0.58, -0.73, and -0.49. Pearson correlation between the CFX disk readings over a 6-month interval was 91%. Conclusions Disk diffusion tests remain to be a useful, reliable and fast screening method for qualitative antimicrobial susceptibility testing for ceftriaxone, cefixime, and cefpodoxime.

  8. Current levels of gonorrhoea screening in MSM in Belgium may have little effect on prevalence: a modelling study.

    Science.gov (United States)

    Buyze, J; Vanden Berghe, W; Hens, N; Kenyon, C

    2018-02-01

    There is considerable uncertainty as to the effectiveness of Neisseria gonorrhoeae (NG) screening in men who have sex with men. It is important to ensure that screening has benefits that outweigh the risks of increased antibiotics resistance. We develop a mathematical model to estimate the effectiveness of screening on prevalence. Separable Temporal Exponential family Random Graph Models are used to model the sexual relationships network, both with main and casual partners. Next, the transmission of Gonorrhoea is simulated on this network. The models are implemented using the R package 'statnet', which we adapted among other things to incorporate infection status at the pharynx, urethra and rectum separately and to distinguish between anal sex, oral sex and rimming. The different screening programmes compared are no screening, 3.5% of the population screened, 32% screened and 50% screened. The model simulates day-by-day evolution for 10 years of a population of 10 000. If half of the population would be screened, the prevalence in the pharynx decreases from 11.9% to 10.2%. We conclude that the limited impact of screening on NG prevalence may not outweigh the increased risk of antibiotic resistance.

  9. A Novel Mechanism of High-Level, Broad-Spectrum Antibiotic Resistance Caused by a Single Base Pair Change in Neisseria gonorrhoeae

    Science.gov (United States)

    2011-09-20

    respect, Eisenstein and Sparling noted that a single base pair deletion in the inverted repeat in the mtrR promoter, a mutation which also confers high...Regulation of the MtrC-MtrD-MtrE efflux-pump system modulates the in vivo fitness of Neisseria gonorrhoeae. J. Infect. Dis. 196:1804 –1812. 21. Eisenstein BI

  10. Comparison of the cystine-tryptic digest agar-carbohydrate co-agglutination and BACTEC Neisseria differentiation methods for identification of Neisseria gonorrhoeae in the clinical laboratory

    International Nuclear Information System (INIS)

    Morello, J.A.; Beheshti, S.; Bohnhoff, M.

    1980-01-01

    The author evaluated CTA-carbohydrate, BACTEC and co-agglutination systems to determine their accuracy for identifying N. gonorrhoeae strains and for distinguishing them from other Neisseria species. BACTEC is a radiometric assay based on the measurement of liberated radiolabelled CO 2 from metabolised carbohydrates which have been tagged with 14 C. (Auth.)

  11. Review and International Recommendation of Methods for Typing Neisseria gonorrhoeae Isolates and Their Implications for Improved Knowledge of Gonococcal Epidemiology, Treatment, and Biology

    Science.gov (United States)

    Unemo, Magnus; Dillon, Jo-Anne R.

    2011-01-01

    Summary: Gonorrhea, which may become untreatable due to multiple resistance to available antibiotics, remains a public health problem worldwide. Precise methods for typing Neisseria gonorrhoeae, together with epidemiological information, are crucial for an enhanced understanding regarding issues involving epidemiology, test of cure and contact tracing, identifying core groups and risk behaviors, and recommending effective antimicrobial treatment, control, and preventive measures. This review evaluates methods for typing N. gonorrhoeae isolates and recommends various methods for different situations. Phenotypic typing methods, as well as some now-outdated DNA-based methods, have limited usefulness in differentiating between strains of N. gonorrhoeae. Genotypic methods based on DNA sequencing are preferred, and the selection of the appropriate genotypic method should be guided by its performance characteristics and whether short-term epidemiology (microepidemiology) or long-term and/or global epidemiology (macroepidemiology) matters are being investigated. Currently, for microepidemiological questions, the best methods for fast, objective, portable, highly discriminatory, reproducible, typeable, and high-throughput characterization are N. gonorrhoeae multiantigen sequence typing (NG-MAST) or full- or extended-length porB gene sequencing. However, pulsed-field gel electrophoresis (PFGE) and Opa typing can be valuable in specific situations, i.e., extreme microepidemiology, despite their limitations. For macroepidemiological studies and phylogenetic studies, DNA sequencing of chromosomal housekeeping genes, such as multilocus sequence typing (MLST), provides a more nuanced understanding. PMID:21734242

  12. Gonorrhoea and Syphilis Epidemiology in Flemish General Practice 2009–2013: Results from a Registry-based Retrospective Cohort Study Compared with Mandatory Notification

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    Christoph Schweikardt

    2016-09-01

    Full Text Available Background: The number of newly diagnosed gonorrhoea and syphilis cases has increased in Flanders in recent years. Our aim was to investigate, to which extent these diagnoses were registered by general practitioners (GPs, and to examine opportunities and limits of the Intego database in this regard. Methods: Data from a retrospective cohort study based on the Flemish Intego general practice database was analyzed for the years 2009–2013. Case definitions were applied. Due to small case numbers obtained, cases were pooled and averaged over the observation period. Frequencies were compared with those calculated from figures of mandatory notification. Results: A total of 91 gonorrhoea and 23 syphilis cases were registered. The average Intego annual frequency of gonorrhoea cases obtained was 11.9 (95% Poisson confidence interval (CI 9.6; 14.7 per 100,000 population, and for syphilis 3.0 (CI 1.9; 4.5, respectively, while mandatory notification was calculated at 14.0 (CI: 13.6, 14.4 and 7.0 (CI: 6.7, 7.3, respectively. Conclusion: In spite of limitations such as small numbers and different case definitions, comparison with mandatory notification suggests that the GP was involved in the large majority of gonorrhoea cases, while the majority of new syphilis cases did not come to the knowledge of the GP.

  13. Structural effect of the Asp345a insertion in penicillin-binding protein 2 from penicillin-resistant strains of Neisseria gonorrhoeae.

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    Fedarovich, Alena; Cook, Edward; Tomberg, Joshua; Nicholas, Robert A; Davies, Christopher

    2014-12-09

    A hallmark of penicillin-binding protein 2 (PBP2) from penicillin-resistant strains of Neisseria gonorrhoeae is insertion of an aspartate after position 345. The insertion resides on a loop near the active site and is immediately adjacent to an existing aspartate (Asp346) that forms a functionally important hydrogen bond with Ser363 of the SxN conserved motif. Insertion of other amino acids, including Glu and Asn, can also lower the rate of acylation by penicillin, but these insertions abolish transpeptidase function. Although the kinetic consequences of the Asp insertion are well-established, how it impacts the structure of PBP2 is unknown. Here, we report the 2.2 Å resolution crystal structure of a truncated construct of PBP2 containing all five mutations present in PBP2 from the penicillin-resistant strain 6140, including the Asp insertion. Commensurate with the strict specificity for the Asp insertion over similar amino acids, the insertion does not cause disordering of the structure, but rather induces localized flexibility in the β2c-β2d loop. The crystal structure resolves the ambiguity of whether the insertion is Asp345a or Asp346a (due to the adjacent Asp) because the hydrogen bond between Asp346 and Ser362 is preserved and the insertion is therefore Asp346a. The side chain of Asp346a projects directly toward the β-lactam-binding site near Asn364 of the SxN motif. The Asp insertion may lower the rate of acylation by sterically impeding binding of the antibiotic or by hindering breakage of the β-lactam ring during acylation because of the negative charge of its side chain.

  14. The Thioredoxin Domain of Neisseria Gonorrhoeae PilB can use Electrons from DsbD to Reduce Downstream Methionine Sulfoxide Reductases

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    Brot,N.; Collet, J.; Johnson, L.; Jonsson, T.; Weissbach, H.; Lowther, W.

    2006-01-01

    The PilB protein from Neisseria gonorrhoeae is located in the periplasm and made up of three domains. The N-terminal, thioredoxin-like domain (NT domain) is fused to tandem methionine sulfoxide reductase A and B domains (MsrA/B). We show that the {alpha} domain of Escherichia coli DsbD is able to reduce the oxidized NT domain, which suggests that DsbD in Neisseria can transfer electrons from the cytoplasmic thioredoxin to the periplasm for the reduction of the MsrA/B domains. An analysis of the available complete genomes provides further evidence for this proposition in other bacteria where DsbD/CcdA, Trx, MsrA, and MsrB gene homologs are all located in a gene cluster with a common transcriptional direction. An examination of wild-type PilB and a panel of Cys to Ser mutants of the full-length protein and the individually expressed domains have also shown that the NT domain more efficiently reduces the MsrA/B domains when in the polyprotein context. Within this framework there does not appear to be a preference for the NT domain to reduce the proximal MsrA domain over MsrB domain. Finally, we report the 1.6 {angstrom} crystal structure of the NT domain. This structure confirms the presence of a surface loop that makes it different from other membrane-tethered, Trx-like molecules including TlpA, CcmG and ResA. Subtle differences are observed in this loop when compared to the N. meningitidis NT domain structure. The data taken together supports the formation of specific NT domain interactions with the MsrA/B domains and its in vivo recycling partner, DsbD.

  15. Susceptibilidad antimicrobiana in vitro de cepas de Neisseria gonorrhoeae procesadas en el instituto nacional de salud, Lima, Perú. 1998-1999

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    José Portilla C

    2003-10-01

    Full Text Available Objetivo: Determinar la frecuencia de susceptibilidad y resistencia in vitro de cepas de Neisseria gonorrhoeae, aisladas en el Laboratorio de Bacterias de Transmisión Sexual del Instituto Nacional de Salud, Lima, Perú, frente a los antimicrobianos de uso actual en el tratamiento de la infección por el gonococo; asimismo, conocer la frecuencia con que se presentan las cepas de N. gonorrhoeae productoras de beta-lactamasas. Material y Métodos: Estudio observacional descriptivo. En el Laboratorio de Bacterias de Transmisión Sexual del Instituto Nacional de Salud, Lima, Perú, se recibieron 130 cepas de N. gonorrhoeae (49 en 1998 y 81 en 1999, procedentes de diferentes localidades del país para confirmación bacteriológica. El método de estudio de susceptibilidad antimicrobiana usado fue el de Concentración inhibitoria mínima (CIM frente a la penicilina, espectinomicina, ceftriaxona, cefotaxima, ciprofloxacina y azitromicina. Resultados: La frecuencia de la resistencia de las cepas de N. gonorrhoeae in vitro a la penicilina fue en 15/49 cepas en el año 1998 y 15/81 cepas en el año 1999. Asimismo, la resistencia a la tetraciclina fue en 31/49 cepas en el año 1998 y 51/81 cepas en 1999. El 100% de las cepas estudiadas fueron sensibles a la espectinomicina, ceftriaxona, cefotaxima y ciprofloxacina. En el país, se reporta en 9/81 cepas de N. gonorrhoeae de susceptibilidad disminuida a la azitromicina. Entre los años 1998 y 1999, se reportaron 21/52 y 6/85, respectivamente de cepas de N. gonorrhoeae productoras de beta-lactamasas. Conclusiones: Se encontró resistencia in vitro de cepas de N. gonorrhoeae frente a la penicilina y tetraciclina. Los antibióticos que se deben usar para el tratamiento de la infección son: espectinomicina, ceftriaxona, cefotaxima y ciprofloxacina. Por primer vez se reporta en el país, cepas de susceptibilidad disminuida a la azitromicina.

  16. High prevalence of HIV, chlamydia and gonorrhoea among men who have sex with men and transgender women attending trusted community centres in Abuja and Lagos, Nigeria.

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    Keshinro, Babajide; Crowell, Trevor A; Nowak, Rebecca G; Adebajo, Sylvia; Peel, Sheila; Gaydos, Charlotte A; Rodriguez-Hart, Cristina; Baral, Stefan D; Walsh, Melissa J; Njoku, Ogbonnaya S; Odeyemi, Sunday; Ngo-Ndomb, Teclaire; Blattner, William A; Robb, Merlin L; Charurat, Manhattan E; Ake, Julie

    2016-01-01

    Sexually transmitted infection (STI) and HIV prevalence have been reported to be higher amongst men who have sex with men (MSM) in Nigeria than in the general population. The objective of this study was to characterize the prevalence of HIV, chlamydia and gonorrhoea in this population using laboratory-based universal testing. TRUST/RV368 represents a cohort of MSM and transgender women (TGW) recruited at trusted community centres in Abuja and Lagos, Nigeria, using respondent-driven sampling (RDS). Participants undergo a structured comprehensive assessment of HIV-related risks and screening for anorectal and urogenital Chlamydia trachomatis and Neisseria gonorrhoeae , and HIV. Crude and RDS-weighted prevalence estimates with 95% confidence intervals (CIs) were calculated. Log-binomial regression was used to explore factors associated with prevalent HIV infection and STIs. From March 2013 to January 2016, 862 MSM and TGW (316 in Lagos and 546 in Abuja) underwent screening for HIV, chlamydia and gonorrhoea at study enrolment. Participants' median age was 24 years [interquartile range (IQR) 21-27]. One-third (34.2%) were identified as gay/homosexual and 65.2% as bisexual. The overall prevalence of HIV was 54.9%. After adjusting for the RDS recruitment method, HIV prevalence in Abuja was 43.5% (95% CI 37.3-49.6%) and in Lagos was 65.6% (95% CI 54.7-76.5%). The RDS-weighted prevalence of chlamydia was 17.0% (95% CI 11.8-22.3%) in Abuja and 18.3% (95% CI 11.1-25.4%) in Lagos. Chlamydia infection was detected only at the anorectal site in 70.2% of cases. The RDS-weighted prevalence of gonorrhoea was 19.1% (95% CI 14.6-23.5%) in Abuja and 25.8% (95% CI 17.1-34.6%) in Lagos. Overall, 84.2% of gonorrhoea cases presented with anorectal infection only. Over 95% of STI cases were asymptomatic. In a multivariable model, increased risk for chlamydia/gonorrhoea was associated with younger age, gay/homosexual sexual orientation and higher number of partners for receptive anal sex

  17. Investigating factors for increased gonorrhoea re-infection in men who have sex with men attending a genitourinary clinic: a qualitative study.

    Science.gov (United States)

    Payne, L; Lawrence, D; Soni, S; Llewellyn, C; Dean, G

    2017-08-01

    The number of confirmed cases of gonorrhoea increased by one-third in England from 2013 to 2014 and the incidence increased by 32% in men who have sex with men (MSM). In our clinic, annual incidence increased by 28.8% (2013) and re-infection (second infection within one-year of initial infection) rose from 6.7% as a proportion of total infections (2009) to 19.4% (2013). The aim of this study was to explore reasons for repeat gonorrhoea infections among MSM. We interviewed 16 MSM about knowledge and awareness of gonorrhoea, antibiotic resistance and attitudes towards safe sex. We used qualitative methods to investigate the potential causes for the rise in gonorrhoea re-infection. Mobile applications were used to meet casual sex partners and arrange impromptu group-sex parties with partner anonymity making contact tracing difficult. The use of recreational drugs was widespread. It was suggested that new technologies could also be used to increase awareness of STI trends and services for at-risk individuals. Participants were concerned about global antibiotic resistance, but felt that behaviour would not change unless there was local evidence of this. Despite knowing gonorrhoea prevalence was high, participants felt their behaviour was unlikely to change and frequently felt resigned to repeat infections. The use of geosocial networking applications to arrange sexual encounters may be contributing to a rise in STIs, as well as recreational drugs, alcohol and sex parties. Networking applications could increase awareness and advertise testing opportunities. In some cases, risk-taking behaviours are unlikely to change, and for these men, regular sexual health screens should be encouraged to detect and treat infections earlier and reduce onward spread.

  18. Characterization of the dsDNA prophage sequences in the genome of Neisseria gonorrhoeae and visualization of productive bacteriophage

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    Maugel Timothy K

    2007-07-01

    Full Text Available Abstract Background Bioinformatic analysis of the genome sequence of Neisseria gonorrhoeae revealed the presence of nine probable prophage islands. The distribution, conservation and function of many of these sequences, and their ability to produce bacteriophage particles are unknown. Results Our analysis of the genomic sequence of FA1090 identified five genomic regions (NgoΦ1 – 5 that are related to dsDNA lysogenic phage. The genetic content of the dsDNA prophage sequences were examined in detail and found to contain blocks of genes encoding for proteins homologous to proteins responsible for phage DNA replication, structural proteins and proteins responsible for phage assembly. The DNA sequences from NgoΦ1, NgoΦ2 and NgoΦ3 contain some significant regions of identity. A unique region of NgoΦ2 showed very high similarity with the Pseudomonas aeruginosa generalized transducing phage F116. Comparative analysis at the nucleotide and protein levels suggests that the sequences of NgoΦ1 and NgoΦ2 encode functionally active phages, while NgoΦ3, NgoΦ4 and NgoΦ5 encode incomplete genomes. Expression of the NgoΦ1 and NgoΦ2 repressors in Escherichia coli inhibit the growth of E. coli and the propagation of phage λ. The NgoΦ2 repressor was able to inhibit transcription of N. gonorrhoeae genes and Haemophilus influenzae HP1 phage promoters. The holin gene of NgoΦ1 (identical to that encoded by NgoΦ2, when expressed in E. coli, could serve as substitute for the phage λ s gene. We were able to detect the presence of the DNA derived from NgoΦ1 in the cultures of N. gonorrhoeae. Electron microscopy analysis of culture supernatants revealed the presence of multiple forms of bacteriophage particles. Conclusion These data suggest that the genes similar to dsDNA lysogenic phage present in the gonococcus are generally conserved in this pathogen and that they are able to regulate the expression of other neisserial genes. Since phage particles were

  19. Type III methyltransferase M.NgoAX from Neisseria gonorrhoeae FA1090 regulates biofilm formation and human cell invasion

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    Agnieszka eKwiatek

    2015-12-01

    Full Text Available Neisseria gonorrhoeae is the etiological factor of the sexually transmitted gonorrhea disease that may lead, under specific conditions, to systemic infections. The gonococcal genome encodes many Restriction Modification (RM systems, which main biological role is to defend the pathogen from potentially harmful foreign DNA. However, RM systems seem also to be involved in several other functions. In this study, we examined the effect of inactivation the N. gonorrhoeae FA1090 ngo0545 gene encoding M.NgoAX methyltransferase on the global gene expression, biofilm formation, interactions with human epithelial host cells and overall bacterial growth. Expression microarrays showed at least a two-fold deregulation of a total of 121 genes in the NgoAX knock-out mutant compared to the wt strain under standard grow conditions. As determined by the assay with crystal violet, the NgoAX knock-out strain formed a slightly larger biofilm biomass per cell than the wt strain (OD570/600 = 13.8  2.24 and 9.35  2.06, respectively. SCLM observations showed that the biofilm formed by the gonococcal ngo0545 gene mutant is more relaxed and dispersed than the one formed by the wt strain. Thickness of the biofilm formed by both strains was 48.3 (14.9 µm for the mutant and 28.6 (4.0 µm for the wt. This more relaxed feature of the biofilm in respect to adhesion and bacterial interactions seems advantageous for pathogenesis of the NgoAX-deficient gonococci at the stage of human epithelial cell invasion. Indeed, the overall adhesion of mutant bacterial cells to human cells was lower than adhesion of the wt gonococci (adhesion index = 0.672 ( 0.2 and 2.15 ( 1.53, respectively; yet, a higher number of mutant than wt bacteria were found inside the Hec-1-B epithelial cells (invasion index = 3.38 ( 0.93  105 for mutant and 4.67 ( 3.09  104 for the wt strain. These results indicate that NgoAX-deficient cells have lower ability to attach to human cells

  20. Case Report of Urethritis in a Male Patient Infected with Two Different Isolates of Multiple Drug-Resistant Neisseria gonorrhoeae

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    Lamiaa Al-Madboly

    2017-11-01

    Full Text Available We report a brief description of a case suffering from bacterial urethritis, conjunctivitis, and arthritis, caused by two different isolates of multiple drug-resistant Neisseria gonorrhoeae. Initial diagnosis was dependent on the patient history, clinical findings, symptoms, and the bacteriological data. Polymerase chain reaction confirmed the identification of the pathogens. Random amplified polymorphic DNA revealed two different patterns. Susceptibility testing was performed using Kirby–Bauer disk diffusion method and the minimum inhibitory concentration was also determined. It revealed multiple drug resistance associated with β-lactamase production. Only gentamicin, rifampicin, and azithromycin were active against the test pathogens. A dual therapy was initiated using gentamicin as well as azithromycin to treat the possible co-infection with Chlamydia trachomatis. Complete recovery of the patient achieved with resolved symptoms a week later.

  1. Case Report of Urethritis in a Male Patient Infected with Two Different Isolates of Multiple Drug-Resistant Neisseria gonorrhoeae.

    Science.gov (United States)

    Al-Madboly, Lamiaa; Gheida, Shereen

    2017-01-01

    We report a brief description of a case suffering from bacterial urethritis, conjunctivitis, and arthritis, caused by two different isolates of multiple drug-resistant Neisseria gonorrhoeae . Initial diagnosis was dependent on the patient history, clinical findings, symptoms, and the bacteriological data. Polymerase chain reaction confirmed the identification of the pathogens. Random amplified polymorphic DNA revealed two different patterns. Susceptibility testing was performed using Kirby-Bauer disk diffusion method and the minimum inhibitory concentration was also determined. It revealed multiple drug resistance associated with β-lactamase production. Only gentamicin, rifampicin, and azithromycin were active against the test pathogens. A dual therapy was initiated using gentamicin as well as azithromycin to treat the possible co-infection with Chlamydia trachomatis . Complete recovery of the patient achieved with resolved symptoms a week later.

  2. Cluster of Neisseria gonorrhoeae Isolates With High-level Azithromycin Resistance and Decreased Ceftriaxone Susceptibility, Hawaii, 2016.

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    Katz, Alan R; Komeya, Alan Y; Kirkcaldy, Robert D; Whelen, A Christian; Soge, Olusegun O; Papp, John R; Kersh, Ellen N; Wasserman, Glenn M; O'Connor, Norman P; O'Brien, Pamela S; Sato, Douglas T; Maningas, Eloisa V; Kunimoto, Gail Y; Tomas, Juval E

    2017-09-15

    The Centers for Disease Control and Prevention (CDC) currently recommends dual therapy with ceftriaxone and azithromycin for gonorrhea to ensure effective treatment and slow emergence of antimicrobial resistance. Since 2013, the prevalence of reduced azithromycin susceptibility increased in the United States; however, these strains were highly susceptible to cephalosporins. We identified a cluster of Neisseria gonorrhoeae isolates with high-level azithromycin resistance, several of which also demonstrated decreased ceftriaxone susceptibility. Eight N. gonorrhoeae isolates collected from 7 patients on Oahu, Hawaii, seen 21 April 2016 through 10 May 2016 underwent routine Etest antimicrobial susceptibility testing by the Hawaii Department of Health. All demonstrated elevated azithromycin minimum inhibitory concentrations (MICs) >256 μg/mL and elevated ceftriaxone MICs (≥0.125 μg/mL). Isolates were sent to the University of Washington and CDC for confirmatory agar dilution testing; sequence data were sent to CDC for analysis. All patients were interviewed and treated, and when possible, partners were interviewed, tested, and treated. All isolates had azithromycin MICs >16 µg/mL and 5 had ceftriaxone MICs = 0.125 µg/mL by agar dilution. All isolates were β-lactamase positive and were resistant to penicillin, tetracycline, and ciprofloxacin. Genomic analysis revealed genetic relatedness. No patients reported recent travel or antibiotic use, and no male patients reported male sex partners. All patients were successfully treated. This cluster of genetically related gonococcal isolates with decreased ceftriaxone susceptibility and high-level azithromycin resistance may bring the threat of treatment failure in the United States with the current recommended dual therapy one step closer. © The Author 2017. Published by Oxford University Press for the Infectious Diseases Society of America. All rights reserved. For permissions, e-mail: journals.permissions@oup.com.

  3. Infection of Human Fallopian Tube Epithelial Cells with Neisseria gonorrhoeae Protects Cells from Tumor Necrosis Factor Alpha-Induced Apoptosis

    Science.gov (United States)

    Morales, Priscilla; Reyes, Paz; Vargas, Macarena; Rios, Miguel; Imarai, Mónica; Cardenas, Hugo; Croxatto, Horacio; Orihuela, Pedro; Vargas, Renato; Fuhrer, Juan; Heckels, John E.; Christodoulides, Myron; Velasquez, Luis

    2006-01-01

    Following infection with Neisseria gonorrhoeae, bacteria may ascend into the Fallopian tubes (FT) and induce salpingitis, a major cause of infertility. In the FT, interactions between mucosal epithelial cells and gonococci are pivotal events in the pathogen's infection cycle and the inflammatory response. In the current study, primary FT epithelial cells were infected in vitro with different multiplicities of infection (MOI) of Pil+ Opa+ gonococci. Bacteria showed a dose-dependent association with cells and induced the secretion of tumor necrosis factor alpha (TNF-α). A significant finding was that gonococcal infection (MOI = 1) induced apoptosis in approximately 30% of cells, whereas increasing numbers of bacteria (MOI = 10 to 100) did not induce apoptosis. Apoptosis was observed in only 11% of cells with associated bacteria, whereas >84% of cells with no adherent bacteria were apoptotic. TNF-α was a key contributor to apoptosis, since (i) culture supernatants from cells infected with gonococci (MOI = 1) induced apoptosis in naïve cultures, suggesting that a soluble factor was responsible; (ii) gonococcal infection-induced apoptosis was inhibited with anti-TNF-α antibodies; and (iii) the addition of exogenous TNF-α induced apoptosis, which was inhibited by the presence of increasing numbers of bacteria (MOI = 10 to 100). These data suggest that TNF-α-mediated apoptosis of FT epithelial cells is likely a primary host defense mechanism to prevent pathogen colonization. However, epithelial cell-associated gonococci have evolved a mechanism to protect the cells from undergoing TNF-α-mediated apoptosis, and this modulation of the host innate response may contribute to establishment of infection. Understanding the antiapoptotic mechanisms used by Neisseria gonorrhoeae will inform the pathogenesis of salpingitis and could suggest new intervention strategies for prevention and treatment of the disease. PMID:16714596

  4. Desarrollo de una Sonda de ADN de Origen Plasmídico para la identificación y detección de Neisseria gonorrhoeae.

    OpenAIRE

    Torres Sánchez, María José

    2016-01-01

    Neisseria gonorrhoeae, es el agente causal de la gonococia, enfermedad de transmisión sexual reconocida como una de las causas principales de morbilidad en muchas zonas del mundo (Donegan, 1985). La gonococia es a menudo recurrente y ocasionalmente produce complicaciones, como la enfermedad inflamatoria pélvica –causa de embarazos ectópicos e infertilidad--, la infección gonocócica diseminada y la epididimitis, entre otras. Ya que el diagnós...

  5. Was an epidemic of gonorrhoea among heterosexuals attending an Adelaide sexual health services associated with variations in sex work policing policy?

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    Li, Bin; Bi, Peng; Waddell, Russell; Chow, Eric Pf; Donovan, Basil; McNulty, Anna; Fehler, Glenda; Loff, Bebe; Shahkhan, Hana; Fairley, Christopher K

    2016-08-01

    A review of historical trends in gonococcal diagnoses made at the Adelaide Sexual Health Clinic (ASHC), South Australia, identified a substantial rise in diagnoses among heterosexuals between 2006 and 2010. Sex work is illegal in South Australia, regulated in Victoria and legal in New South Wales. This and other factors that could have influenced the epidemic were explored in this analysis. Retrospective analyses of gonorrhoea diagnoses made by sexual health services between 1990 and 2012 in three Australian state capitals, Melbourne (Victoria) and Sydney (New South Wales) were undertaken. At the ASHC the proportion of gonorrhoea diagnoses was higher between 2006 and 2010 among heterosexual men (5.34% vs 0.84%, p<0.001), non-sex worker women (0.64% vs 0.28%, p<0.001) and female sex workers (FSWs) (1.75% vs 0.24%, p<0.001) compared with other years. This relationship was not seen at the Melbourne Sexual Health Clinic and corresponding data from the Sydney Sexual Health Centre showed that FSWs were less likely to have gonorrhoea between 2006 and 2010 than the other groups (p=0.746, p=0.522, p=0.024, respectively). At ASHC FSWs were significantly more likely to be diagnosed between 2006 and 2010 (OR 2.8, 95% CI 1.48 to 5.27, p=0.002). Charges against sex workers peaked in 2007/2008. A substantial, self-limiting rise in diagnoses of heterosexual gonorrhoea was seen in Adelaide FSWs between 2006 and 2010. Removing barriers to condom use is vital to the prevention of HIV and STI transmission. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

  6. Prevalence of Chlamydia trachomatis, Trichomonas vaginalis and Neisseria gonorrhoeae Based on Data Collected by a Network of Clinical Microbiology Laboratories, in Italy.

    Science.gov (United States)

    Salfa, Maria Cristina; Suligoi, Barbara

    Bacterial and protozoal sexually transmitted infections (STIs), such as Chlamydia trachomatis, Trichomonas vaginalis and Neisseria gonorrhoeae, may cause acute symptoms, chronic infections and severe long-term complications. The complications of these infections in women include pelvic inflammatory disease, chronic pelvic pain, tubal infertility, ectopic pregnancy, and infertility. Moreover, infection during pregnancy is associated with premature rupture of the membranes, low birth weight and miscarriage.In Italy, Chlamydia trachomatis and Trichomonas vaginalis infections are not subject to mandatory reporting; while gonorrhoea is subject to mandatory reporting.To extend surveillance to STIs that are widespread yet often asymptomatic and to improve the knowledge on the epidemiology of these infections in Italy, in 2009 the "Centro Operativo AIDS of the Istituto Superiore di SanitÁ", in collaboration with the Association of Italian Clinical Microbiologists (AMCLI, Associazione Microbiologi Clinici Italiani), launched the sentinel STIs surveillance system based on a network of 13 clinical microbiology laboratories.The main objective of the surveillance was to assess the prevalence and risk factors associated with Chlamydia trachomatis, Trichomonas vaginalis and Neisseria gonorrhoea infections among individuals attending microbiology laboratories in Italy.

  7. Gonorrhoea diagnoses in a network of STI clinics in Spain during the period 2006–2010: differences by sex and transmission route

    Science.gov (United States)

    2013-01-01

    Background Gonorrhoea infection is one of the most common bacterial sexually transmitted infections and an important cause of morbidity and serious complications. The objectives of this paper are: a) to describe gonorrhoea cases diagnosed in a network of 15 (out of 16) STI clinics in Spain during 2006–2010; b) to analyse differences among men who have sex with men (MSM), men who have sex exclusively with women (MSW) and women; and c) to evaluate factors associated to with HIV co-infection. Methods All gonorrhoea cases diagnosed in the network were included (25.7% of total cases notified in Spain). Data were collected by clinical staff. Descriptive/bivariate analyses were carried out stratifying by sex and transmission category; association and trends were evaluated using the chi-square test. Factors associated with HIV co-infection were estimated using a logistic regression model. Results 2385 cases were included: 55.3% among MSM, 31.3% among MSW and 13.3% among females; cases among MSM increased from 55.8% in 2006 to 62.9% in 2010 while no trends were found among the other two groups. Most MSM cases were Spaniards (72%), aged 25–34 years (46%), 49% reported previous STI and 25% concurrent STI (excluding HIV); casual partners were the commonest source of infection, and 21% of cases had rectal gonorrhoea. MSW cases did not differ from MSM by age, origin or source of infection, but frequencies of prior or concurrent STI were lower. Female cases were younger than male, were mostly foreigners (58%), and 41% were sex workers; concurrent STI (other than HIV) were diagnosed in 30%; 20.4% had symptoms (72.5% and 89.2% in MSM and MSW), and pharyngeal location was present in 30%. HIV co-infection was highest in MSM (20.9%). Co-infection was associated with age > 35 years, low educational level, being Western European or Latin-American, being MSM, having previous or concurrent STI and reporting contact with an HIV-infected partner; it was inversely associated with

  8. Predominant porB1A and porB1B genotypes and correlation of gene mutations with drug resistance in Neisseria gonorrhoeae isolates in Eastern China

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    Tang Renxian

    2010-11-01

    Full Text Available Abstract Background Variations of porB1A and porB1B genes and their serotypes exist in Neisseria gonorrhoeae isolates from different geographical areas, and some site mutations in the porB1B gene correlate with drug resistance. Methods The β-lactamase production of N. gonorrhoeae isolates was determined by paper acidometric test and nitrocefin discs. The porB1A and porB1B genes of 315 non-penicillinase-producting N. gonorrhoeae (non-PPNG strains were amplified by PCR for sequencing to determine serotypes and site mutations. A duplex PCR was designed to simultaneously detect both porB1A and porB1B genes. Penicillin and tetracycline resistance was assessed by an in vitro drug sensitivity test. Results Of the N. gonorrhoeae isolates, 31.1% tested positive for porB1A and 68.9% for porB1B genes. All the 98 porB1A+ isolates belonging to IA6 serotype with either no mutation at the 120 and 121 sites (88.8% or a D120G (11.2% mutation and were no resistance to both penicillin and tetracycline. Among the 217 porB1B+ isolates, 26.7%, 22.6% and 11.5% belonged to IB3, IB3/6 and IB4 serotypes, respectively. Particularly, two novel chimeric serotypes, IB3/6-IB2 and IB2-IB4-IB2, were found in 77 and 8 porB1B+ isolates. Two hundred and twelve (97.7% of the porB1B+ isolates were presented G120 and/or A121 mutations with 163 (76.9% at both sites. Interestingly, within the 77 porB1B+ isolates belonging to IB3/6-IB2 serotype, 15 were discovered to possess novel deletions at both A121 and N122 sites. All the replacement mutations at these sites in PorB1B were correlated with resistance and the deletion mutation showed the highest resistance. Conclusion N. gonorrhoeae isolates circulating in Eastern China include a sole PorB1A serotype (IA6 and five PorB1B serotypes. Multiple mutations in porB1B genes, including novel A121 and N122 deletions, are correlated with high levels of penicillin and tetracycline resistance.

  9. Prevalencia de anticuerpos anti-Chlamydia trachomatis y anti-Neisseria gonorrhoeae en grupos de individuos de la población mexicana Prevalence of antibodies against Chlamydia trachomatis and Neisseria gonorrhoeae in Mexican populations

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    María del Carmen Cravioto

    2003-01-01

    Full Text Available OBJETIVO: Estimar la prevalencia de infección por Chlamydia trachomatis (CT y Neisseria gonorrhoeae (NG en grupos de individuos con diferente riesgo para infecciones de transmisión sexual. MATERIAL Y MÉTODOS: Estudio transversal multicéntrico efectuado en el Instituto Nacional de Ciencias Médicas y Nutrición Salvador Zubirán, de la Ciudad de México, de enero de 1992 a diciembre de 1993, en el que se estudiaron 945 individuos en edad reproductiva, 585 mujeres y 360 hombres. Según su riesgo para infecciones de transmisión sexual se clasificaron en grupos de alto y bajo riesgo. Los de alto riesgo incluyeron mujeres infértiles con daño tubario, mujeres con embarazo ectópico o aborto, hombres infértiles, pacientes con VIH/SIDA, hombres homo o bisexuales y trabajadoras del sexo comercial (TSC. Los de bajo riesgo: mujeres primigestas, hombres fértiles y mujeres infértiles sin daño tubario. Se determinó en duplicado IgG e IgA anti-NG y anti-CT en suero, por análisis inmunoenzimático, utilizando como antígeno el pili de NG y la fracción L1 de CT. Se calcularon porcentajes. RESULTADOS: En mujeres la prevalencia para NG fue IgG 13.7% e IgA 14.3%, y para CT fue IgG 11.4% e IgA 4.4%. En hombres, NG 3.3% y 13.3%, respectivamente, y para CT 7.2% y 5.5%, respectivamente. En TSC se encontró NG en 31.2 % y 28.4%, respectivamente, y para CT 25.0% y 5.7%, respectivamente. En mujeres con infertilidad por daño tubario, NG 5.6% y 9.8%, respectivamente, y CT 8.4% y 1.4%, respectivamente. En 110 primigestas jóvenes, NG 4.5% y 10.0%, respectivamente, y CT 3.6% y 9.1%, respectivamente. CONCLUSIONES: Estos datos confirman la prevalencia elevada de Neisseria gonorrhoeae y Chlamydia trachomatis en trabajadoras del sexo comercial y en hombres homo/bisexuales, pero no en otros grupos de alto riesgo como las mujeres infértiles, con aborto o embarazo ectópico.OBJECTIVE: To estimate the prevalence of Chlamydia trachomatis (CT and Neisseria gonorrhoeae

  10. Should urologists care for the pharyngeal infection of Neisseria gonorrhoeae or Chlamydia trachomatis when we treat male urethritis?

    Science.gov (United States)

    Hamasuna, Ryoichi; Takahashi, Satoshi; Uehara, Shinya; Matsumoto, Tetsuro

    2012-06-01

    Detection of Neisseria gonorrhoeae (NG) or Chlamydia trachomatis (CT) from the pharynx of women or men is not uncommon. However, there is no recommendation how urologists should care for the pharyngeal infection of men with urethritis in Japan. The aim of this study is to clarify the prevalence of NG or CT infection in the pharynx of men and to show a recommendation for urologists. The Japanese reports about the detection of NG or CT from the pharynx or the oral cavity of men in Japan are reviewed in the literature from 1990 to 2011. The prevalence of NG or CT in the pharynx was 4% or 6% in men who attended clinics, and 20% or 6% in men who were positive for NG or CT from genital specimens, respectively. Single 1-g dose ceftriaxone was recommended to treat pharyngeal NG, but no evidence was found for pharyngeal CT. There was not enough evidence for recommendation. However, when men with urethritis only caused by NG or CT are treated through the guideline of the Japanese Society of Sexually Transmitted Infection, we do not think additional tests or treatment for the pharynx are needed when a single 1-g dose ceftriaxone for gonococcal urethritis or a single 1- or 2- g dose azithromycin is prescribed for chlamydial urethritis in Japan.

  11. Chlamydia trachomatis, Neisseria gonorrhoeae, and Trichomonas vaginalis screening and treatment of pregnant women in Port-au-Prince, Haiti.

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    Bristow, Claire C; Mathelier, Patricia; Ocheretina, Oksana; Benoit, Daphne; Pape, Jean W; Wynn, Adriane; Klausner, Jeffrey D

    2017-10-01

    In Haiti, routine screening for Chlamydia trachomatis (CT), Neisseria gonorrhoeae (NG), and Trichomonas vaginalis (TV) among pregnant women is not conducted; yet these sexually transmitted infections (STIs) are associated with adverse birth and newborn health outcomes. We aimed to assess the acceptability and feasibility of screening and the prevalence of STIs among pregnant women in Port-au-Prince, Haiti. Pregnant women of at least 18 years of age who attend Haitian Study Group for Kaposi's sarcoma and Opportunistic Infections (GHESKIO) clinics in Port-au-Prince, Haiti provided self-collected vaginal swab specimens. Laboratory testing was done with Xpert® CT/NG and Xpert® TV. The results of this study showed that of the 322 pregnant women who visited GHESKIO for their regular scheduled appointments, 300 (93.2%) consented for CT, NG, and TV testing. Of those, 107 women (35.7%) tested positive for at least one STI. There were 42 (14.7%) cases of CT, 8 (2.8%) NG, and 83 (29.0%) TV infections. Most infections were treated - 122 of 133 (91.7%). In summary, we found that it was highly acceptable and feasible to implement CT, NG, and TV screening among pregnant women in Port-au-Prince, Haiti. We found high prevalence of STIs among pregnant women, which suggest that STI screening in this population may be warranted.

  12. Molecular characterization of Neisseria gonorrhoeae isolates in Almaty, Kazakhstan, by VNTR analysis, Opa-typing and NG-MAST.

    Science.gov (United States)

    Kushnir, Anastasiya V; Muminov, Talgat A; Bayev, Assylzhan I; Khrapov, Evgeny A; Filipenko, Maxim L

    2012-04-01

    In the present study, new variable number tandem repeats (VNTR) loci in the Neisseria gonorrhoeae genome were identified in silico. VNTR analysis scheme using PCR and agarose or polyacrylamide gel electrophoresis was developed based on nine VNTR loci with various degrees of polymorphism. The method was used to genotype a collection of 48 isolates, obtained from patients with gonorrhea in Almaty, Kazakhstan during the period from December 2008 to November 2009. This collection of isolates was also characterized by the opa-typing and multiantigen sequence typing (NG-MAST). The discriminatory power of the VNTR analysis translated by Hunter-Gaston Discrimination Index (HGDI) was similar to that of opa typing (HGDI=0.98 versus 0.97) and slightly higher than that of NG-MAST (HDGI=0.95). The adjusted Rand (AR) coefficients and Wallace coefficients showed that the overall concordance between the typing methods was not high. VNTR analysis described here is simple, inexpensive, easy to interpret, and it would be reliable for the comparison of data obtained in different laboratories. The proposed VNTR loci might be used for epidemiological studies of gonococcal infections. Copyright © 2012 Elsevier B.V. All rights reserved.

  13. Antimicrobial Resistance Expressed by Neisseria gonorrhoeae: A Major Global Public Health Problem in the 21st Century.

    Science.gov (United States)

    Unemo, Magnus; Del Rio, Carlos; Shafer, William M

    2016-06-01

    Neisseria gonorrhoeae is a strictly human pathogen that is typically transmitted by sexual contact. The associated disease gonorrhea has plagued humankind for thousands of years, with a current estimated incidence of 78 million cases per year. Advances in antimicrobial discovery in the 1920s and 1930s leading to the discovery of sulfonamides and penicillin begun the era of effective antimicrobial treatment of gonorrhea. Unfortunately, the gonococcus developed decreased susceptibility or even resistance to these initially employed antibiotics, a trend that continued over subsequent decades with each new antibiotic that was brought into clinical practice. As this pattern of resistance has continued into the 21st century, there is now reason for great concern, especially in an era when few new antibiotics have prospects for use as treatment of gonorrhea. Here, we review the history of gonorrhea treatment regimens and gonococcal resistance to antibiotics, the mechanisms of resistance, resistance monitoring schemes that exist in different international settings, global responses to the challenge of resistance, and prospects for future treatment regimens in the 21st century.

  14. Cervical Infection with Herpes simplex Virus, Chlamydia trachomatis, and Neisseria gonorrhoeae among Symptomatic Women, Dubai, UAE: A Molecular Approach

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    Davood Mehrabani

    2014-01-01

    Full Text Available Tragically, genital tract infections are still a major public health problem in many regions. This study was undertaken to determine the prevalence of cervical infection with Herpes simplex virus (HSV, Chlamydia trachomatis (CT, and Neisseria gonorrhoeae (NG among married women referring to Iranian Hospital, Dubai, UAE. In a retrospective cross-sectional survey, 201 female patients aged 16–80 years who referred to the Obstetrics and Gynecology Department of Iranian Hospital, Dubai, UAE, in 2010 were enrolled. The patients were categorized into three age groups: 15–30 (group I, 31–40 (group II, and ≥41 years old (group III. A cervical swab sample was collected from each woman and the prevalence of cervical infection with HSV, CT, and NG was determined by PCR method. HSV, CT, and NG were detected in 6.5%, 10.4%, and 5.5% of swab samples, respectively. Regarding age, a significant difference was noticed for prevalence of NG and HSV between groups I and III. Because of public health importance of sexual transmitted diseases (STDs, their long-lasting impact on quality of life, and their economic burden, preventing measures and education of women seem necessary.

  15. Restriction endonucleases from invasive Neisseria gonorrhoeae cause double-strand breaks and distort mitosis in epithelial cells during infection.

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    Linda Weyler

    Full Text Available The host epithelium is both a barrier against, and the target for microbial infections. Maintaining regulated cell growth ensures an intact protective layer towards microbial-induced cellular damage. Neisseria gonorrhoeae infections disrupt host cell cycle regulation machinery and the infection causes DNA double strand breaks that delay progression through the G2/M phase. We show that intracellular gonococci upregulate and release restriction endonucleases that enter the nucleus and damage human chromosomal DNA. Bacterial lysates containing restriction endonucleases were able to fragment genomic DNA as detected by PFGE. Lysates were also microinjected into the cytoplasm of cells in interphase and after 20 h, DNA double strand breaks were identified by 53BP1 staining. In addition, by using live-cell microscopy and NHS-ester stained live gonococci we visualized the subcellular location of the bacteria upon mitosis. Infected cells show dysregulation of the spindle assembly checkpoint proteins MAD1 and MAD2, impaired and prolonged M-phase, nuclear swelling, micronuclei formation and chromosomal instability. These data highlight basic molecular functions of how gonococcal infections affect host cell cycle regulation, cause DNA double strand breaks and predispose cellular malignancies.

  16. Restriction endonucleases from invasive Neisseria gonorrhoeae cause double-strand breaks and distort mitosis in epithelial cells during infection.

    Science.gov (United States)

    Weyler, Linda; Engelbrecht, Mattias; Mata Forsberg, Manuel; Brehwens, Karl; Vare, Daniel; Vielfort, Katarina; Wojcik, Andrzej; Aro, Helena

    2014-01-01

    The host epithelium is both a barrier against, and the target for microbial infections. Maintaining regulated cell growth ensures an intact protective layer towards microbial-induced cellular damage. Neisseria gonorrhoeae infections disrupt host cell cycle regulation machinery and the infection causes DNA double strand breaks that delay progression through the G2/M phase. We show that intracellular gonococci upregulate and release restriction endonucleases that enter the nucleus and damage human chromosomal DNA. Bacterial lysates containing restriction endonucleases were able to fragment genomic DNA as detected by PFGE. Lysates were also microinjected into the cytoplasm of cells in interphase and after 20 h, DNA double strand breaks were identified by 53BP1 staining. In addition, by using live-cell microscopy and NHS-ester stained live gonococci we visualized the subcellular location of the bacteria upon mitosis. Infected cells show dysregulation of the spindle assembly checkpoint proteins MAD1 and MAD2, impaired and prolonged M-phase, nuclear swelling, micronuclei formation and chromosomal instability. These data highlight basic molecular functions of how gonococcal infections affect host cell cycle regulation, cause DNA double strand breaks and predispose cellular malignancies.

  17. Evaluation of six nucleic acid amplification tests used for diagnosis of Neisseria gonorrhoeae in Russia compared with an international strictly validated real-time porA pseudogene polymerase chain reaction.

    Science.gov (United States)

    Shipitsyna, E; Zolotoverkhaya, E; Hjelmevoll, S O; Maximova, A; Savicheva, A; Sokolovsky, E; Skogen, V; Domeika, M; Unemo, M

    2009-11-01

    In Russia, laboratory diagnosis of gonorrhoea has been mainly based on microscopy only and, in some settings, relatively rare suboptimal culturing. In recent years, Russian developed and manufactured nucleic acid amplification tests (NAAT) have been implemented for routine diagnosis of Neisseria gonorrhoeae. However, these NAATs have never been validated to any international well-recognized diagnostic NAAT. This study aims to evaluate the performance characteristics of six Russian NAATs for N. gonorrhoeae diagnostics. In total, 496 symptomatic patients were included. Five polymerase chain reaction (PCR) assays and one real-time nucleic acid sequence based amplification (NASBA) assay, developed by three Russian companies, were evaluated on urogenital samples, i.e. cervical and first voided urine (FVU) samples from females (n = 319), urethral and FVU samples from males (n = 127), and extragenital samples, i.e. rectal and pharyngeal samples, from 50 additional female patients with suspicion of gonorrhoea. As reference method, an international strictly validated real-time porA pseudogene PCR was applied. The prevalence of N. gonorrhoeae was 2.7% and 16% among the patients providing urogenital and extragenital samples, respectively. The Russian NAATs and the reference method displayed high level of concordance (99.4-100%). The sensitivities, specificities, positive predictive values and negative predictive values of the Russian tests in different specimens were 66.7-100%, 100%, 100%, and 99.4-100%, respectively. Russian N. gonorrhoeae diagnostic NAATs comprise relatively good performance characteristics. However, larger studies are crucial and, beneficially, the Russian assays should also be evaluated to other international highly sensitive and specific, and ideally Food and Drug Administration approved, NAATs such as Aptima Combo 2 (Gen-Probe).

  18. Remarkable increase of Neisseria gonorrhoeae with decreased susceptibility of azithromycin and increase in the failure of azithromycin therapy in male gonococcal urethritis in Sendai in 2015.

    Science.gov (United States)

    Yasuda, Mitsuru; Ito, Shin; Hatazaki, Kyoko; Deguchi, Takashi

    2016-12-01

    The antimicrobial resistance of Neisseria gonorrhoeae is a serious problem worldwide. In this study, we examined the susceptibility of N. gonorrhoeae isolated from male gonococcal urethritis in Sendai in 2014 and 2015. Furthermore, of all cases, we investigated the clinical efficacy of a single 2-g dose of extended-release azithromycin (AZM-SR) in the treatment of male gonococcal urethritis retrospectively. Sixty N. gonorrhoeae strains in 2014 and 54 strains in 2015 were isolated from male gonococcal urethritis and stored each year. The MIC of AZM was ≥1 mg/L in 4 strains (6.7%) in 2014 and in 13 strains (24.1%) in 2015 and the number of strains having ≥1 mg/L MIC increased significantly (P = 0.016). Microbiological efficacy was evaluated in 32 and 29 of these patients, and the rates of treatment success were 93.8% and 79.3%, respectively. All of the treatment failures were caused by strains having a MIC of AZM of ≥0.5 mg/L. In particular, the increase in the isolates having a MIC of AZM of ≥1 mg/L was remarkable. Therefore, it was thought that the increase in these strains was the reason for the increase in treatment failures in 2015. Because no other drug is effective, it is currently necessary to use AZM-SR to treat gonococcal infections caused by ceftriaxone-resistant strains or patients allergic to ceftriaxone. To prevent a further increase in resistance to AZM, we should not use AZM-SR to treat normal cases of gonococcal infection. Copyright © 2016 Japanese Society of Chemotherapy and The Japanese Association for Infectious Diseases. Published by Elsevier Ltd. All rights reserved.

  19. Prevalence of asymptomatic urethritis by Chlamydia trachomatis and Neisseria gonorrhoeae and associated risk factors among males living with HIV-1

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    Guilherme Almeida Rosa da Silva

    2018-03-01

    Full Text Available ABSTRACT Objectives The increase in HIV transmissibility in non-ulcerative sexually transmitted infection is already well-established. It is estimated that symptomatic carriers of N. gonorrhoeae and C. trachomatis have a relative risk of 4.8-fold and 3.6-fold, respectively, for the sexual acquisition of HIV. This type of evaluation for asymptomatic urethritis is necessary to reinforce strategies to combat HIV transmission. This study aims to assess the prevalence of patients with asymptomatic urethritis among men diagnosed with HIV-1 and determine the risk factors associated with this infection. Methods We enrolled a total of 115 male patients aged 18 years or older who have been diagnosed with HIV infection and have no symptoms of urethritis or other sexually transmitted infections and who have been evaluated between May and August 2015 in a follow-up visit at the Immunology Outpatient Clinic of a Brazilian University Hospital. Results Four asymptomatic patients were positive for C. trachomatis and were considered asymptomatic carriers of urethritis. Prevalence was 3.47%. Patients who were positive for C. trachomatis urethritis had a lower mean age (p = 0.015. Conclusion The presence of asymptomatic sexually transmitted infection is a challenge in clinical practice. We recommend that, in outpatient practice, the habit of inquiring on previous sexual behavior to obtain more information about risks and associations with asymptomatic sexually transmitted infection, a routine physical examination and complementary tests to detect STI pathogens should be performed to discard these conditions. The development of rapid tests for this purpose should also be encouraged.

  20. Prevalence of asymptomatic urethritis by Chlamydia trachomatis and Neisseria gonorrhoeae and associated risk factors among males living with HIV-1.

    Science.gov (United States)

    Silva, Guilherme Almeida Rosa da; Motta, Heloisa Loureiro de Sá Neves; Souza, Erik Friedrich Alex de; Cardoso, Pedro Afonso Nogueira Moises; Pilotto, José Henrique; Eyer-Silva, Walter Araujo; Ribeiro, Luiz Cláudio Pereira; Santos, Mônica Soares Dos; Azevedo, Marcelo Costa Velho Mendes de; Pinto, Jorge Francisco da Cunha; Motta, Rogerio Neves; Ferry, Fernando Raphael de Almeida

    2018-03-08

    The increase in HIV transmissibility in non-ulcerative sexually transmitted infection is already well-established. It is estimated that symptomatic carriers of N. gonorrhoeae and C. trachomatis have a relative risk of 4.8-fold and 3.6-fold, respectively, for the sexual acquisition of HIV. This type of evaluation for asymptomatic urethritis is necessary to reinforce strategies to combat HIV transmission. This study aims to assess the prevalence of patients with asymptomatic urethritis among men diagnosed with HIV-1 and determine the risk factors associated with this infection. We enrolled a total of 115 male patients aged 18 years or older who have been diagnosed with HIV infection and have no symptoms of urethritis or other sexually transmitted infections and who have been evaluated between May and August 2015 in a follow-up visit at the Immunology Outpatient Clinic of a Brazilian University Hospital. Four asymptomatic patients were positive for C. trachomatis and were considered asymptomatic carriers of urethritis. Prevalence was 3.47%. Patients who were positive for C. trachomatis urethritis had a lower mean age (p = 0.015). The presence of asymptomatic sexually transmitted infection is a challenge in clinical practice. We recommend that, in outpatient practice, the habit of inquiring on previous sexual behavior to obtain more information about risks and associations with asymptomatic sexually transmitted infection, a routine physical examination and complementary tests to detect STI pathogens should be performed to discard these conditions. The development of rapid tests for this purpose should also be encouraged.

  1. AtlA functions as a peptidoglycan lytic transglycosylase in the Neisseria gonorrhoeae type IV secretion system.

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    Kohler, Petra L; Hamilton, Holly L; Cloud-Hansen, Karen; Dillard, Joseph P

    2007-08-01

    Type IV secretion systems require peptidoglycan lytic transglycosylases for efficient secretion, but the function of these enzymes is not clear. The type IV secretion system gene cluster of Neisseria gonorrhoeae encodes two peptidoglycan transglycosylase homologues. One, LtgX, is similar to peptidoglycan transglycosylases from other type IV secretion systems. The other, AtlA, is similar to endolysins from bacteriophages and is not similar to any described type IV secretion component. We characterized the enzymatic function of AtlA in order to examine its role in the type IV secretion system. Purified AtlA was found to degrade macromolecular peptidoglycan and to produce 1,6-anhydro peptidoglycan monomers, characteristic of lytic transglycosylase activity. We found that AtlA can functionally replace the lambda endolysin to lyse Escherichia coli. In contrast, a sensitive measure of lysis demonstrated that AtlA does not lyse gonococci expressing it or gonococci cocultured with an AtlA-expressing strain. The gonococcal type IV secretion system secretes DNA during growth. A deletion of ltgX or a substitution in the putative active site of AtlA severely decreased DNA secretion. These results indicate that AtlA and LtgX are actively involved in type IV secretion and that AtlA is not involved in lysis of gonococci to release DNA. This is the first demonstration that a type IV secretion peptidoglycanase has lytic transglycosylase activity. These data show that AtlA plays a role in type IV secretion of DNA that requires peptidoglycan breakdown without cell lysis.

  2. Extracts of Canadian first nations medicinal plants, used as natural products, inhibit neisseria gonorrhoeae isolates with different antibiotic resistance profiles.

    Science.gov (United States)

    Cybulska, Paulina; Thakur, Sidharath D; Foster, Brian C; Scott, Ian M; Leduc, Renée I; Arnason, John T; Dillon, Jo-Anne R

    2011-07-01

    Neisseria gonorrhoeae (Ng) has developed resistance to most antimicrobial agents and the antibiotics recommended for therapy are restricted, for the most part, to third generation cephalosporins. In order to investigate new potential sources of antimicrobial agents, the antibacterial properties of 14 Canadian plants used in traditional First Nations' medicine were tested against Ng isolates having differing antimicrobial susceptibility profiles. Ethanolic extracts of 14 Canadian botanicals, analyzed by high-performance liquid chromatography, were tested for their antimicrobial activity (disc diffusion and/or agar dilution assays) against susceptible Ng reference strains and a panel of 28 Ng isolates with various antimicrobial resistance profiles. Extracts of Arctostaphylos uva ursi (kinnikinnick or bearberry), Hydrastis canadensis (goldenseal), Prunus serotina (black cherry), and Rhodiola rosea (roseroot) inhibited the growth of all Ng isolates with minimum inhibitory concentrations of 32 μg/mL, 4 to 32 μg/mL, 16 to >32 μg/mL, and 32 to 64 μg/mL, respectively. Extracts of Acorus americanus (sweet flag), Berberis vulgaris (barberry), Cimicifuga racemosa (black cohosh), Equisetum arvense (field horsetail), Gaultheria procumbens (wintergreen), Ledum groenlandicum (Labrador tea), Ledum palustre (marsh Labrador tea), Oenothera biennis (common evening primrose), Sambucus nigra (elderberry), and Zanthoxylum americanum (prickly ash) had weak or no antimicrobial activity against the Ng isolates with minimum inhibitory concentrations ≥256 μg/mL. The phytochemical berberine from H. canadensis inhibited the growth of all Ng isolates. The phytochemicals, salidroside and rosavin, present in R. rosea, also showed inhibitory activity against Ng strains. Canadian botanicals represent a potential source of novel compounds which inhibit Ng, including isolates resistant to antibiotics.

  3. Auditing the use and assessing the clinical utility of microscopy as a point-of-care test for Neisseria gonorrhoeae in a Sexual Health clinic.

    Science.gov (United States)

    Mensforth, Sarah; Thorley, Nicola; Radcliffe, Keith

    2018-02-01

    We assessed whether urethral microscopy was performed as per clinic protocol for male clinic attendees reporting contact with Neisseria gonorrhoeae (GC), urethral symptoms or given a diagnosis of epididymo-orchitis (EO) over a 12-month period (9732 patients). Prevalence of gonorrhoea in the contacts, urethral symptoms and EO groups was 50, 12.7 and 1.6%, respectively. Microscopy was performed reliably for contacts (96%), those with discharge/dysuria with evidence of urethritis on examination (98%), but not those with EO (43%). We explored the clinical utility of microscopy as a point-of-care test for identifying urethral GC in each subgroup, using the APTIMA Combo 2 CT/GC nucleic acid amplification test as the comparator (1710 patients). Sensitivity of microscopy for each subgroup was good; there was no statistical difference between subgroup sensitivity using Fisher's exact test. Microscopy is valuable to ensure prompt diagnosis and contact tracing. All GC contacts were treated 'epidemiologically'; however, half of GC contacts did not have GC. Microscopy identified the majority of GC cases, including amongst contacts (71% of heterosexual contacts, 66% of contacts reporting sex with men). We propose that epidemiological treatment for GC contacts should be reconsidered on the grounds of antibiotic stewardship, favouring use of microscopy to guide treatment decisions.

  4. Prevalence of chlamydia, gonorrhoea, syphilis and trichomonas in Aboriginal and Torres Strait Islander Australians: a systematic review and meta-analysis.

    Science.gov (United States)

    Graham, Simon; Smith, Lucy Watchirs; Fairley, Christopher K; Hocking, Jane

    2016-04-01

    Higher notification rates of sexually transmissible infections (STIs) are reported among Aboriginal and Torres Strait Islander (Aboriginal) compared with non-Aboriginal people in Australia. The aim of this study is to estimate the pooled prevalence of chlamydia, gonorrhoea, syphilis and trichomonas among Aboriginal people in Australia by sex, age-group, setting (clinic vs population/community-based) and population group [adults, pregnant females, young people (12-29 years) and prisoners]. The databases Medline, PubMed and Web of Science were searched in May 2015. A meta-analysis was conducted to estimate the pooled prevalence of the four STIs in Aboriginal people and if possible, by gender, age-group, setting and population group. A total of 46 studies were included. The pooled prevalence was 11.2% (95%CI: 9.4-13.0%) for chlamydia (36 studies), 12.5% (95%CI: 10.5-14.6%) for gonorrhoea (28 studies), 16.8% (95%CI: 11.0-22.6%) for syphilis (13 studies) and 22.6% (95%CI: 18.5-26.7%) for trichomonas (11 studies); however, there was significant heterogeneity between studies (I(2) Aboriginal people through community-based programs that target asymptomatic young people.

  5. Vigilancia de la resistencia de Neisseria gonorrhoeae en un hospital de la provincia de Santa Fe, Argentina: 1997-2004 Resistance surveillance of Neisseria gonorrhoeae in a hospital in Santa Fe province, Argentina: 1997-2004

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    E. De Los A. Méndez

    2008-09-01

    Full Text Available Se determinaron los fenotipos de resistencia caracterizados por la concentración inhibitoria mínima, la difusión con discos y la producción de β-lactamasa de 434 aislamientos de Neisseria gonorrhoeae obtenidos de pacientes atendidos en el Servicio de Enfermedades de Transmisión Sexual del Hospital Dr. José María Cullen, Santa Fe, Argentina. Se realizaron pruebas de sensibilidad a los siguientes antimicrobianos: penicilina, tetraciclina, ciprofloxacina, espectinomicina, azitromicina y ceftriaxona. A tres aislamientos resistentes a ciprofloxacina se les realizó electroforesis de campo pulsado. Se destacaron tres situaciones epidemiológicas de interés: en el año 1997, alta incidencia de aislamientos con resistencia plasmídica a tetraciclina (33,3%; en el período 2002-2004, un aumento significativo de la resistencia plasmídica a penicilina (9,7% a 34,8%; y en el año 2000, la emergencia de dos de los tres primeros aislamientos con resistencia a quinolonas del país. El primer aislamiento resistente a azitromicina en nuestro hospital emerge en el 2004. Este trabajo jerarquiza el rol del Laboratorio de Microbiología Clínica en la orientación del tratamiento empírico de la gonorrea.Resistance phenotypes characterized by minimum inhibitory concentration, disk diffusion and β-lactamase production were determined in 434 isolates from patients attending the Sexually Transmitted Disease Service at Dr. José María Cullen Hospital in Santa Fe, Argentina. Susceptibility tests to penicillin, tetracycline, ciprofloxacin, espectinomycin, azithromycin and ceftriaxone were performed. Pulsed-field gel electrophoresis was conducted made to on three ciprofloxacin-resistant isolates. Epidemiologically speaking, three interesting events should be highlighted: during 1997, plasmid-mediated high level tetracycline-resistant strains were observed (33.3%; from 2002 to 2004 a significant increase of plasmid-mediated penicillin-resistant strains was

  6. Amplified Fragment Length Polymorphism Fingerprinting for Identification of a Core Group of Neisseria gonorrhoeae Transmitters in the Population Attending a Clinic for Treatment of Sexually Transmitted Diseases in Amsterdam, The Netherlands

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    Spaargaren, Joke; Stoof, Jeroen; Fennema, Han; Coutinho, Roel; Savelkoul, Paul

    2001-01-01

    Amplified fragment length polymorphism analysis seems well suited for studying the epidemiology of isolates of Neisseria gonorrhoeae obtained from patients attending the Sexually Transmitted Disease Outpatient Clinic in Amsterdam, The Netherlands. It shows potential to identify the core group of transmitters.

  7. Evaluation of the new AmpliSens multiplex real-time PCR assay for simultaneous detection of Neisseria gonorrhoeae, Chlamydia trachomatis, Mycoplasma genitalium, and Trichomonas vaginalis.

    Science.gov (United States)

    Rumyantseva, Tatiana; Golparian, Daniel; Nilsson, Christian S; Johansson, Emma; Falk, My; Fredlund, Hans; Van Dam, Alje; Guschin, Alexander; Unemo, Magnus

    2015-10-01

    In this study, we performed an evaluation of the new CE-marked multiplex real-time AmpliSens N.gonorrhoeae/C.trachomatis/M.genitalium/T.vaginalis-MULTIPRIME-FRT PCR assay compared to APTIMA tests, i.e., APTIMA COMBO 2 assay, APTIMA Trichomonas vaginalis assay (FDA-approved), and two different APTIMA Mycoplasma genitalium assays (research use only; one of them only used for discrepancy analysis). Vaginal swabs (n = 209) and first-void urine (FVU) specimens from females (n = 498) and males (n = 554), consecutive attendees (n = 1261) at a dermatovenerological clinic in Sweden, were examined. The sensitivity of the AmpliSens PCR assay for detection of C. trachomatis (6.3% prevalence), M. genitalium (5.7% prevalence), N. gonorrhoeae (0.3% prevalence), and T. vaginalis (0.08% prevalence) was 97.5% (95% confidence interval (CI): 91.2-99.6%), 81.9% (95% CI: 70.7-89.7%), 100% (95% CI: 40.2-100%) and 100% (95% CI: 16.5-100%), respectively. The specificity of the AmpliSens PCR assay was 100% (95% CI: 99.6-100%) for all agents. The analytical sensitivity and specificity for N. gonorrhoeae detection was excellent, i.e., 55 international gonococcal strains detected and 135 isolates of 13 non-gonococcal Neisseria species were negative. In conclusion, the multiplex real-time AmpliSens N.gonorrhoeae/C.trachomatis/M.genitalium/T.vaginalis-MULTIPRIME-FRT PCR assay demonstrated high sensitivity and excellent specificity for the detection of C. trachomatis, N. gonorrhoeae, and T. vaginalis, and excellent specificity but suboptimal sensitivity for M. genitalium detection. © 2015 APMIS. Published by John Wiley & Sons Ltd.

  8. Prevalence of Neisseria gonorrhoeae and Chlamydia trachomatis infection in men attending STD clinics in Brazil Prevalência de Neisseria gonorrhoeae e infecção pela Chlamydia trachomatis em homens atendidos em clínicas de DST no Brasil

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    Marcelo Joaquim Barbosa

    2010-10-01

    Full Text Available INTRODUCTION: The study aimed to assess the prevalence of Neisseria gonorrhoeae and Chlamydia trachomatis infections and identify demographic, behavioral and clinical factors correlated withsuch infections in men attending six sexually transmitted disease clinics in Brazil. METHODS: Multicentric, cross-sectional study performed among men attending STD clinics in Brazil. The study included STD clinics in six cities distributed throughout the five geographic regions of Brazil in 2005. Patients provided 20 ml of first catch urine for testing for NG and CT by DNA-PCR. RESULTS: A total of 767 (92.9% men were included in the study. The mean age was 26.5 (SD 8.3 years-old. Prevalence of Chlamydia infection was 13.1% (95%CI 10.7%-15.5% and gonorrhea was 18.4% (95%CI 15.7%-21.1%. Coinfection prevalence was 4.4% (95%CI 2.95%-5.85% in men who sought attendance in STI clinics. Factors identified as associated with C. trachomatis were younger age (15-24 [OR=1.4 (95%CI 1.01-1.91], present urethral discharge [OR=4.8 (95%CI 1.52-15.05], genital warts [OR=3.0 (95%CI 1.49-5.92] and previous history of urethral discharge [OR=2.4 (95%CI 1.11-5.18]. Variables associated with gonorrhea were younger age (15 to 24 [OR=1.5 (95%CI 1.09-2.05], presence of urethral discharge [OR=9.9 (95%CI 5.53-17.79], genital warts [OR=18.3 (95%CI 8.03-41.60] and ulcer present upon clinical examination [OR=4.9 (95%CI 1.06-22.73]. CONCLUSIONS: These findings have important implications for education and prevention actions directed toward men at risk of HIV/STD. A venue-based approach to offer routine screening for young men in STD clinics should be stimulated.INTRODUÇÃO: Nosso objetivo foi acessar a prevalência de Neisseria gonorrhoeae e Chlamydia trachomatis e identificar fatores demográficos, comportamentais e clínicos correlacionados a essas infecções em homens atendidos em clínicas de doenças sexualmente transmissíveis no Brasil. MÉTODOS: Estudo multicêntrico, transversal

  9. Susceptibility of Neisseria gonorrhoeae to azithromycin and ceftriaxone in China: A retrospective study of national surveillance data from 2013 to 2016.

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    Yue-Ping Yin

    2018-02-01

    Full Text Available Gonorrhea remains one of the most common sexually transmitted diseases worldwide. Successful treatment has been hampered by emerging resistance to each of the antibiotics recommended as first-line therapies. We retrospectively analyzed the susceptibility of gonorrhea to azithromycin and ceftriaxone using data from the China Gonococcal Resistance Surveillance Programme (China-GRSP in order to provide evidence for updating the treatment recommendations in China.In this study, we included 3,849 isolates collected from patients with a confirmed positive Neisseria gonorrhoeae (N. gonorrhoeae culture at clinic visits during the period of 1 January 2013 through 31 December 2016 in 7 provinces. Antimicrobial susceptibility testing of gonorrhea isolates using agar dilution was conducted to determine minimum inhibitory concentration (MIC. Resistance to azithromycin (RTA was defined as MIC ≥ 1.0 mg/l, and decreased susceptibility to ceftriaxone (DSC was defined as MIC ≥ 0.125 mg/l. The prevalence of isolates with RTA was 18.6% (710/3,827; 95% CI 17.4%-19.8%. The percentage of patients with DSC fluctuated between 9.7% and 12.2% over this period. The overall prevalence of isolates with both RTA and DSC was 2.3% (87/3,827; 95% CI 1.9%-2.8% and it increased from 1.9% in 2013 to 3.3% in 2016 (chi-squared test for trend, P = 0.03. Study limitations include the retrospective study design and potential biases in the sample, which may overrepresent men with symptomatic infection, coastal residents, and people reporting as heterosexual.To our knowledge, this is the first national study on susceptibility of N. gonorrhoeae to azithromycin and ceftriaxone in China. Our findings indicate high rates of RTA and DSC from 2013 to 2016. Although dual therapy with azithromycin and ceftriaxone has been recommended by WHO and many countries to treat gonorrhea, reevaluation of this therapy is needed prior to its introduction in China.

  10. Selective testing of women based on age for genital Chlamydia trachomatis and Neisseria gonorrhoeae infection in a centralized regional microbiology laboratory.

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    Church, Deirdre L; Amante, L; Semeniuk, H; Gregson, D B

    2007-04-01

    Calgary Laboratory Services, Alberta, Canada, provides microbiology services via a centralized laboratory to the Calgary Health Region. A selective genital Chlamydia trachomatis (CT)/Neisseria gonorrhoeae (GC) testing policy for women >35 years was implemented. The changes in physician ordering practice, the rate of detection of infections, and the test turnaround times were monitored. The volume of tests, the cost/test, and the total service costs accrued in the year before and after this policy change were compared. An immediate impact was a 30% decrease in tests performed due to the laboratory rejecting samples from older women. Subsequently, physicians' practice changed so that tests were ordered when test criteria were met. Detection rates did not change in any age group. A 27.9% decrease in the total service costs resulted in a labor reduction of 0.2 FTE. Selective testing of women >35 years with a low prevalence of CT/GC infection is clinically relevant and cost-effective.

  11. In Vitro Activity of Ertapenem versus Ceftriaxone against Neisseria gonorrhoeae Isolates with Highly Diverse Ceftriaxone MIC Values and Effects of Ceftriaxone Resistance Determinants: Ertapenem for Treatment of Gonorrhea?

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    Golparian, Daniel; Limnios, Athena; Whiley, David; Ohnishi, Makoto; Lahra, Monica M.; Tapsall, John W.

    2012-01-01

    Clinical resistance to the currently recommended extended-spectrum cephalosporins (ESCs), the last remaining treatment options for gonorrhea, is being reported. Gonorrhea may become untreatable, and new treatment options are crucial. We investigated the in vitro activity of ertapenem, relative to ceftriaxone, against N. gonorrhoeae isolates and the effects of ESC resistance determinants on ertapenem. MICs were determined using agar dilution technique or Etest for international reference strains (n = 17) and clinical N. gonorrhoeae isolates (n = 257), which included the two extensively drug-resistant (XDR) strains H041 and F89 and additional isolates with high ESC MICs, clinical ESC resistance, and other types of clinical high-level and multidrug resistance (MDR). Genetic resistance determinants for ESCs (penA, mtrR, and penB) were sequenced. In general, the MICs of ertapenem (MIC50 = 0.032 μg/ml; MIC90 = 0.064 μg/ml) paralleled those of ceftriaxone (MIC50 = 0.032 μg/ml; MIC90 = 0.125 μg/ml). The ESC resistance determinants mainly increased the ertapenem MIC and ceftriaxone MIC at similar levels. However, the MIC ranges for ertapenem (0.002 to 0.125 μg/ml) and ceftriaxone (gonorrhea, particularly for the currently identified ESC-resistant cases and possibly in a dual antimicrobial therapy regimen. However, further knowledge regarding the genetic determinants (and their evolution) conferring resistance to both antimicrobials, and clear correlates between genetic and phenotypic laboratory parameters and clinical treatment outcomes, is essential. PMID:22547617

  12. Antimicrobial susceptibility of Neisseria gonorrhoeae isolates from patients attending a public referral center for sexually transmitted diseases in Belo Horizonte, State of Minas Gerais, Brazil

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    Ligia Maria Bedeschi Costa

    2013-06-01

    Full Text Available Introduction The aim of this study was to determine the antimicrobial susceptibility of Neisseria gonorrhoeae isolates obtained from patients attending a public referral center for sexually transmitted diseases and specialized care services (STD/SCS in Belo Horizonte, Brazil. Methods Between March 2011 and February 2012, 201 specimens of Neisseria gonorrhoeae were consecutively obtained from men with symptoms of urethritis and women with symptons of cervicitis or were obtained during their initial consultation. The strains were tested using the disk diffusion method, and the minimum inhibitory concentrations of azithromycin, cefixime, ceftriaxone, ciprofloxacin, chloramphenicol, penicillin, tetracycline and spectinomycin were determined using the E-test. Results The specimens were 100% sensitive to cefixime, ceftriaxone and spectinomycin and exhibited resistances of 4.5% (9/201, 21.4% (43/201, 11.9% (24/201, 22.4% (45/201 and 32.3% (65/201 to azithromycin, ciprofloxacin, chloramphenicol, penicillin and tetracycline, respectively. Intermediate sensitivities of 17.9% (36/201, 4% (8/201, 16.9% (34/201, 71.1% (143/201 and 22.9% (46/201 were observed for azithromycin, ciprofloxacin, chloramphenicol, penicillin and tetracycline, respectively. The specimens had plasmid-mediated resistance to penicillin PPNG 14.5% (29/201 and tetracycline TRNG 11.5% (23/201. Conclusions The high percentage of detected resistance to penicillin, tetracycline, chloramphenicol and ciprofloxacin indicates that these antibiotics are not appropriate for gonorrhea treatment at the Health Clinic and possibly in Belo Horizonte. The resistance and intermediate sensitivity of these isolates indicates that caution is recommended in the use of azithromycin and emphasizes the need to establish mechanisms for the surveillance of antimicrobial resistance for the effective control of gonorrhea.

  13. Phenotypic and molecular characterization of Neisseria gonorrhoeae isolates from Slovenia, 2006-12: rise and fall of the multidrug-resistant NG-MAST genogroup 1407 clone?

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    Jeverica, Samo; Golparian, Daniel; Matičič, Mojca; Potočnik, Marko; Mlakar, Boštjan; Unemo, Magnus

    2014-06-01

    To determine the phenotypic and molecular characteristics of Neisseria gonorrhoeae isolates obtained between 2006 and 2012 in Slovenia. Gonococcal isolates obtained between 2006 and 2012 in Slovenia (n = 194) were investigated with Etest for susceptibility to cefixime, ceftriaxone, penicillin, ciprofloxacin, azithromycin, tetracycline, gentamicin and spectinomycin. All isolates were examined with N. gonorrhoeae multiantigen sequence typing for molecular epidemiology and sequencing of the major extended-spectrum cephalosporin (ESC) resistance determinants (penA, mtrR and penB) was performed. The overall prevalence of decreased susceptibility or resistance to cefixime and ceftriaxone (MIC ≥0.125 mg/L) was 11% and 5%, respectively. The decreased susceptibility or resistance showed an epidemic peak in 2011 (33% for cefixime and 11% for ceftriaxone), decreasing to 6% and 4%, respectively, in 2012. ST1407 (9% of isolates), ST21 (6%) and ST225 (6%) were the most common sequence types (STs) during 2006-12. Genogroup G1407 (ST1407 most prevalent ST), an internationally spread clone with decreased susceptibility or resistance to ESCs, was most prevalent (48%) in 2009. However, the G1407 prevalence then declined: in 2010, 30%; in 2011, 28%; and in 2012, 8%. Instead, in 2012 the ESC- and ciprofloxacin-susceptible G21 was the predominant genogroup (26%). The prevalence of gonococcal resistance to ESCs in Slovenia has been high, but fluctuating. Fortunately, in 2012 some ESC- and ciprofloxacin-susceptible clones, such as genogroups G21, G1195 and G2992, appeared to have mainly replaced the multidrug-resistant G1407 clone, a replacement also seen in several European countries. © The Author 2014. Published by Oxford University Press on behalf of the British Society for Antimicrobial Chemotherapy. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

  14. Deteccion de Chlamydia trachomatis en muestras uretrales mediante inmunofluorescencia directa Detecção de Chlamydia trachomatis em amostras uretrais mediante imunofluorescência direta Detection of Chlamydia trachomatis in urethral samples by means of direct immunofluorescence

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    Myra Wilson Schuster

    1989-12-01

    Full Text Available Se estudiaron 82 pacientes con uretritis para la búsqueda de Chlamydia trachomatis mediante inmunofluorescencia directa, Neisscria gonorrhoeae, Mycoplastna y Ureaplasma mediante métodos estándar. Se encontró un 19,5% de Chlamydia trachomatis y en 11 de ellos (68,8% se encontró asociada a otras bacterias y estos pacientes presentó una secreción escasa-gelatinosa.Em 82 doentes com uretrite foi pesquisada a presença de Chlamydia trachomatis, utilizando a prova da imunofluorescência direta, e de Neisseria gonorrhoeae, Mycoplasma e Ureaplasma, utilizando os métodos padrões. Ch. trachomatis foi encontrada em 19,5% dos casos, sendo que em 11 deles (68,8% observou-se associação entre Chlamydia e as outras bactérias pesquisadas. Nesses pacientes observou-se presença de secreção uretral escassa e de aspecto gelatinoso.The presence of Chlamydia trachomatis was studied by the direct immunofluorescence test, as also was that of Neisseria gonorrhoeae, Mycoplasma and Ureaplasma by the standard methods, in 82 patients with urethral discharge. Ch. trachomatis was found in 19.5% (16 of the cases and in 11 of them (68.8% there was association with the other bacteria investigated. This eleven patients presented a scanty gelatinous discharge.

  15. Association between visual inspection of the cervix with acetic acid examination and high-risk human papillomavirus infection, Chlamydia trachomatis, Neisseria gonorrhoeae and Trichomonas vaginalis in Papua New Guinea.

    Science.gov (United States)

    Vallely, Andrew J; Toliman, Pamela J; Ryan, Claire; Rai, Glennis; Wapling, Johanna; Gabuzzi, Josephine; Kumbia, Antonia; Kombuk, Benny; Kombati, Zure; Vallely, Lisa M; Kelly-Hanku, Angela; Wand, Handan; Tabrizi, Sepehr N; Mola, Glen D L; Kaldor, John M

    2018-01-30

    Papua New Guinea (PNG) has among the highest estimated burdens of cervical cancer globally but currently has no national cervical screening program. Visual inspection of the cervix with acetic acid (VIA) is a low-cost screening strategy endorsed by the World Health Organization that has been adopted in many low-resource settings but not previously evaluated in PNG. To evaluate the association between VIA examination findings and high-risk HPV (hrHPV) infection; and the impact of concomitant genital Chlamydia trachomatis, Neisseria gonorrhoeae and Trichomonas vaginalis on the interpretation of VIA findings. A prospective clinical cohort study among women aged 30-59 years attending Well Woman Clinics in PNG. Main outcome measures were VIA examination findings and laboratory-confirmed hrHPV, C. trachomatis, N. gonorrhoeae and T. vaginalis. A total of 614 women were enrolled, of whom 87.5% (537/614) underwent VIA, and 12.5% (77/614) did not due to pre-existing cervicitis or inability to visualise the transformation zone. Among the 537 women who underwent VIA, 21.6% were VIA positive, 63.7% VIA negative, and 14.7% had indeterminate findings. The prevalence of hrHPV infection (n = 614) was 14.7%; C. trachomatis, 7.5%; N. gonorrhoeae, 8.0%; and T. vaginalis, 15.0%. VIA positive women were more likely to have HPV16 (odds ratio: 5.0; 95%CI: 1.6-15.6; P = 0.006) but there was no association between HPV18/45, all hrHPV types (combined), C. trachomatis, N. gonorrhoeae or T. vaginalis. VIA positivity was associated with HPV16, but not with other hrHPV infections, nor with genital C. trachomatis, N. gonorrhoeae or T. vaginalis in this setting. © 2018 The Royal Australian and New Zealand College of Obstetricians and Gynaecologists.

  16. Time-Motion Analysis of Four Automated Systems for the Detection of Chlamydia trachomatis and Neisseria gonorrhoeae by Nucleic Acid Amplification Testing.

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    Williams, James A; Eddleman, Laura; Pantone, Amy; Martinez, Regina; Young, Stephen; Van Der Pol, Barbara

    2014-08-01

    Next-generation diagnostics for Chlamydia trachomatis and Neisseria gonorrhoeae are available on semi- or fully-automated platforms. These systems require less hands-on time than older platforms and are user friendly. Four automated systems, the ABBOTT m2000 system, Becton Dickinson Viper System with XTR Technology, Gen-Probe Tigris DTS system, and Roche cobas 4800 system, were evaluated for total run time, hands-on time, and walk-away time. All of the systems evaluated in this time-motion study were able to complete a diagnostic test run within an 8-h work shift, instrument setup and operation were straightforward and uncomplicated, and walk-away time ranged from approximately 90 to 270 min in a head-to-head comparison of each system. All of the automated systems provide technical staff with increased time to perform other tasks during the run, offer easy expansion of the diagnostic test menu, and have the ability to increase specimen throughput. © 2013 Society for Laboratory Automation and Screening.

  17. Duration of polymerase chain reaction-detectable DNA after treatment of Chlamydia trachomatis, Neisseria gonorrhoeae, and Trichomonas vaginalis infections in women.

    Science.gov (United States)

    Williams, James A; Ofner, Susan; Batteiger, Byron E; Fortenberry, J Dennis; Van Der Pol, Barbara

    2014-03-01

    To avoid positive results attributable to residual DNA, the Centers for Disease Control and Prevention recommends avoiding repeat testing with nucleic-acid based tests within 3 weeks after treatment of chlamydial (Chlamydia trachomatis [CT]) or gonococcal (Neisseria gonorrhoeae [GC]) infection. We retrospectively analyzed the duration of detectable DNA from a longitudinal cohort of adolescent women after diagnosis and treatment of infection with CT, GC, or Trichomonas vaginalis (TV). Vaginal swabs were obtained weekly from young women for up to 12 weeks (observation period) after treatment of CT, GC and TV infections. Swabs were tested using a commercially available first generation nucleic acid amplification test (NAAT) for CT and GC, and a laboratory developed NAAT for TV. Kaplan-Meier statistics were used to estimate median time to the first negative DNA-based polymerase chain reaction (PCR) result. Observation periods were available for analysis for 195, 82 and 102 treatments for CT, GC, and TV infection, respectively. Median time to a first negative PCR result for CT, GC, and TV was 9 (range 0-84), 6 (0-76), and 7 (0-84) days, and by day 21, 89%, 95%, and 85% were negative, respectively. Data from this retrospective analysis indicate that greater than 85% of these young women did not have detectable CT, GC, or TV DNA by day 21 post-treatment. This data may be useful to clinicians for patient management and post-treatment testing purposes.

  18. ATP Induces IL-1β Secretion in Neisseria gonorrhoeae-Infected Human Macrophages by a Mechanism Not Related to the NLRP3/ASC/Caspase-1 Axis

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    Killen García

    2016-01-01

    Full Text Available Neisseria gonorrhoeae (Ngo has developed multiple immune evasion mechanisms involving the innate and adaptive immune responses. Recent findings have reported that Ngo reduces the IL-1β secretion of infected human monocyte-derived macrophages (MDM. Here, we investigate the role of adenosine triphosphate (ATP in production and release of IL-1β in Ngo-infected MDM. We found that the exposure of Ngo-infected MDM to ATP increases IL-1β levels about ten times compared with unexposed Ngo-infected MDM (P0.05 and caspase-1 (CASP1, P>0.05. In addition, ATP was not able to modify caspase-1 activity in Ngo-infected MDM but was able to increase pyroptosis (P>0.01. Notably ATP treatment defined an increase of positive staining for IL-1β with a distinctive intracellular pattern of distribution. Collectively, these data demonstrate that ATP induces IL-1β secretion by a mechanism not related to the NLRP3/ASC/caspase-1 axis and likely is acting at the level of vesicle trafficking or pore formation.

  19. Identification of a conserved protein involved in anaerobic unsaturated fatty acid synthesis in Neiserria gonorrhoeae: implications for facultative and obligate anaerobes that lack FabA

    Science.gov (United States)

    Isabella, Vincent M.; Clark, Virginia L.

    2011-01-01

    SUMMARY Transcriptome analysis of the facultative anaerobe, Neisseria gonorrhoeae, revealed that many genes of unknown function were induced under anaerobic conditions. Mutation of one such gene, NGO1024, encoding a protein belonging to the 2-nitropropane dioxygenase-like superfamiliy of proteins, was found to result in an inability of gonococci to grow anaerobically. Anaerobic growth of an NG1024 mutant was restored upon supplementation with unsaturated fatty acids (UFA), but not with the saturated fatty acid palmitate. Gonococcal fatty acid profiles confirmed that NGO1024 was involved in UFA synthesis anaerobically, but not aerobically, demonstrating that gonococci contain two distinct pathways for the production of UFAs, with a yet unidentified aerobic mechanism, and an anaerobic mechanism involving NGO1024. Expression of genes involved in classical anaerobic UFA synthesis, fabA, fabM, and fabB, was toxic in gonococci and unable to complement a NGO1024 mutation, suggesting that the chemistry involved in gonococcal anaerobic UFA synthesis is distinct from that of the classical pathway. NGO1024 homologs, which we suggest naming UfaA, form a distinct lineage within the 2-nitropropane dioxygenase-like superfamily, and are found in many facultative and obligate anaerobes that produce UFAs but lack fabA, suggesting that UfaA is part of a widespread pathway involved in UFA synthesis. PMID:21895795

  20. Screening tests for Chlamydia trachomatis or Neisseria gonorrhoeae using the cobas 4800 PCR system do not require a second test to confirm: an audit of patients issued with equivocal results at a sexual health clinic in the Northwest of England, U.K.

    Science.gov (United States)

    Hopkins, Mark J; Smith, Godfrey; Hart, Ian J; Alloba, Fath

    2012-11-01

    To assess the clinical utility of supplementary PCRs following a positive cobas 4800 CT/NG PCR screening test result. Laboratory reports, for Chlamydia trachomatis or Neisseria gonorrhoeae, issued to genitourinary medicine patients between April 2010 and April 2011 were reviewed retrospectively. Positive reports were routinely confirmed by supplementary PCRs and N gonorrhoeae culture. Clinical records of patients with unconfirmed positive (equivocal) reports were retrieved to determine if the infection was confirmed by a second sample obtained at patient recall and the impact of this process on antibiotic management. Over 15 000 patients were tested during the study period. The prevalence of chlamydia and gonorrhoea was 972 (5.75%) and 76 (0.50%), respectively. A further 78 chlamydia and 2 gonorrhoea equivocal reports were issued. Only 56 (72%) patients with an equivocal chlamydia report returned to the clinic, and of these, only 41 (73%) gave a second sample to retest. Positive predictive value (PPV) of the PCR screening test was calculated at 98.0% and 97.5% for detection of chlamydia infection from urine and rectal swabs, respectively. Most patients accepted antibiotic treatment before their infection status had been confirmed. Prevalence of gonorrhoea infection was low but the PPV of the screening PCR in urine specimens remained high (98.75%). Equivocal reports introduce delays to patient management, while the risk of unnecessary antibiotic therapy appears acceptable to most patients. The cobas 4800 CT/NG PCR screening assay can achieve UK testing standards (PPV >90%) for chlamydia, and low prevalence gonorrhoea in urine without supplementary tests. A patient-led confirmation algorithm is proposed.

  1. Antimicrobial susceptibilities and molecular typing of neisseria gonorrhoeae isolates at a medical centre in Taiwan, 2001-2013 with an emphasis on high rate of azithromycin resistance among the isolates.

    Science.gov (United States)

    Liu, Yen-Hung; Huang, Yu-Tsung; Liao, Chun-Hsing; Hsueh, Po-Ren

    2018-05-01

    A high prevalence of gonococcal resistance to various antimicrobials and Neisseria gonorrhoeae isolates exhibiting resistance to extended-spectrum cephalosporins have been reported in the past few decades. A total of 226 N. gonorrhoeae isolates obtained from the National Taiwan University Hospital from 2001 to 2013 were evaluated. The minimum inhibitory concentrations (MICs) of the isolates to antimicrobials were determined by the agar dilution method and interpreted using the 2017 clinical breakpoints or epidemiological cut-off values recommended by the Clinical and Laboratory Standards Institute (CLSI) and European Committee on Antimicrobial Susceptibility Testing (EUCAST). The genetic relatedness of these isolates was determined by multilocus sequence typing. None of the isolates was resistant to ceftriaxone and cefotaxime, and the resistance rates to cefixime, spectinomycin, cefpodoxime, ciprofloxacin, and penicillin were 0.4%, 0.4%, 13.3%, 91.6%, and 87.6%, respectively. The rate of isolates resistant to azithromycin was 14.6% (EUCAST criteria), which is higher than in previous surveillance studies. A total of 57 sequence types (ST) were identified, and ST1901, ST7365, and ST1927 prevailed. Isolates of ST8143 emerged after 2011. ST1901 isolates had relatively higher MIC values for ceftriaxone and azithromycin than those of the other STs. In conclusion, ceftriaxone remains an effective drug of choice for gonorrhoeal management in Taiwan. High rates of azithromycin resistance among N. gonorrhoeae isolates were found. The circulating ST1901 strains with high MIC values for ceftriaxone and azithromycin and the emerging ST8143 strains were alarming. Copyright © 2018 Elsevier B.V. and International Society of Chemotherapy. All rights reserved.

  2. Impact of the New Abbott mPLUS feature on clinical laboratory efficiencies of abbott RealTime assays for detection of HIV-1, Hepatitis C Virus, Hepatitis B Virus, Chlamydia trachomatis, and Neisseria gonorrhoeae.

    Science.gov (United States)

    Lucic, Danijela; Jones, Sara; Wiesneth, Russ; Barry, Cathy; Webb, Erika; Belova, Larissa; Dolan, Peggy; Ho, Shiaolan; Abravaya, Klara; Cloherty, Gavin

    2013-12-01

    Diagnostic laboratories are under increasing pressure to improve and expand their services. Greater flexibility in sample processing is a critical factor that can improve the time to results while reducing reagent waste, making laboratories more efficient and cost-effective. The introduction of the Abbott mPLUS feature, with the capacity for extended use of amplification reagents, significantly increases the flexibility of the m2000 platform and enables laboratories to customize their workflows based on sample arrival patterns. The flexibility in sample batch size offered by mPLUS enables significant reductions in processing times. For hepatitis B virus tests, a reduction in sample turnaround times of up to 30% (105 min) was observed for batches of 12 samples compared with those for batches of 24 samples; for Chlamydia trachomatis/Neisseria gonorrhoeae tests, the ability to run batches of 24 samples reduced the turnaround time by 83% (54 min) compared with that for batches of 48 samples. Excellent correlations between mPLUS and m2000 standard condition results were observed for all RealTime viral load assays evaluated in this study, with correlation r values of 0.998 for all assays tested. For the qualitative RealTime C. trachomatis/N. gonorrhoeae assay, the overall agreements between the two conditions tested were >98% for C. trachomatis and 100% for N. gonorrhoeae. Comparable precision results were observed for the two conditions tested for all RealTime assays. The enhanced mPLUS capability provides clinical laboratories with increased efficiencies to meet increasingly stringent turnaround time requirements without increased costs associated with discarding partially used amplification reagents.

  3. Estimating prevalence trends in adult gonorrhoea and syphilis in low- and middle-income countries with the Spectrum-STI model: results for Zimbabwe and Morocco from 1995 to 2016.

    Science.gov (United States)

    Korenromp, Eline L; Mahiané, Guy; Rowley, Jane; Nagelkerke, Nico; Abu-Raddad, Laith; Ndowa, Francis; El-Kettani, Amina; El-Rhilani, Houssine; Mayaud, Philippe; Chico, R Matthew; Pretorius, Carel; Hecht, Kendall; Wi, Teodora

    2017-12-01

    To develop a tool for estimating national trends in adult prevalence of sexually transmitted infections by low- and middle-income countries, using standardised, routinely collected programme indicator data. The Spectrum-STI model fits time trends in the prevalence of active syphilis through logistic regression on prevalence data from antenatal clinic-based surveys, routine antenatal screening and general population surveys where available, weighting data by their national coverage and representativeness. Gonorrhoea prevalence was fitted as a moving average on population surveys (from the country, neighbouring countries and historic regional estimates), with trends informed additionally by urethral discharge case reports, where these were considered to have reasonably stable completeness. Prevalence data were adjusted for diagnostic test performance, high-risk populations not sampled, urban/rural and male/female prevalence ratios, using WHO's assumptions from latest global and regional-level estimations. Uncertainty intervals were obtained by bootstrap resampling. Estimated syphilis prevalence (in men and women) declined from 1.9% (95% CI 1.1% to 3.4%) in 2000 to 1.5% (1.3% to 1.8%) in 2016 in Zimbabwe, and from 1.5% (0.76% to 1.9%) to 0.55% (0.30% to 0.93%) in Morocco. At these time points, gonorrhoea estimates for women aged 15-49 years were 2.5% (95% CI 1.1% to 4.6%) and 3.8% (1.8% to 6.7%) in Zimbabwe; and 0.6% (0.3% to 1.1%) and 0.36% (0.1% to 1.0%) in Morocco, with male gonorrhoea prevalences 14% lower than female prevalence. This epidemiological framework facilitates data review, validation and strategic analysis, prioritisation of data collection needs and surveillance strengthening by national experts. We estimated ongoing syphilis declines in both Zimbabwe and Morocco. For gonorrhoea, time trends were less certain, lacking recent population-based surveys. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted

  4. In Vitro Activity of the New Fluoroketolide Solithromycin (CEM-101) against a Large Collection of Clinical Neisseria gonorrhoeae Isolates and International Reference Strains, Including Those with High-Level Antimicrobial Resistance: Potential Treatment Option for Gonorrhea?

    Science.gov (United States)

    Golparian, Daniel; Fernandes, Prabhavathi; Ohnishi, Makoto; Jensen, Jörgen S.

    2012-01-01

    Gonorrhea may become untreatable, and new treatment options are essential. We investigated the in vitro activity of the first fluoroketolide, solithromycin. Clinical Neisseria gonorrhoeae isolates and reference strains (n = 246), including the two extensively drug-resistant strains H041 and F89 and additional isolates with clinical cephalosporin resistance and multidrug resistance, were examined. The activity of solithromycin was mainly superior to that of other antimicrobials (n = 10) currently or previously recommended for gonorrhea treatment. Solithromycin might be an effective treatment option for gonorrhea. PMID:22354296

  5. In Vivo-Selected Compensatory Mutations Restore the Fitness Cost of Mosaic penA Alleles That Confer Ceftriaxone Resistance in Neisseria gonorrhoeae.

    Science.gov (United States)

    Vincent, Leah R; Kerr, Samuel R; Tan, Yang; Tomberg, Joshua; Raterman, Erica L; Dunning Hotopp, Julie C; Unemo, Magnus; Nicholas, Robert A; Jerse, Ann E

    2018-04-03

    Resistance to ceftriaxone in Neisseria gonorrhoeae is mainly conferred by mosaic penA alleles that encode penicillin-binding protein 2 (PBP2) variants with markedly lower rates of acylation by ceftriaxone. To assess the impact of these mosaic penA alleles on gonococcal fitness, we introduced the mosaic penA alleles from two ceftriaxone-resistant (Cro r ) clinical isolates (H041 and F89) into a Cro s strain (FA19) by allelic exchange and showed that the resultant Cro r mutants were significantly outcompeted by the Cro s parent strain in vitro and in a murine infection model. Four Cro r compensatory mutants of FA19 penA41 were isolated independently from mice that outcompeted the parent strain both in vitro and in vivo One of these compensatory mutants (LV41C) displayed a unique growth profile, with rapid log growth followed by a sharp plateau/gradual decline at stationary phase. Genome sequencing of LV41C revealed a mutation (G348D) in the acnB gene encoding the bifunctional aconitate hydratase 2/2 methylisocitrate dehydratase. Introduction of the acnB G348D allele into FA19 penA41 conferred both a growth profile that phenocopied that of LV41C and a fitness advantage, although not as strongly as that exhibited by the original compensatory mutant, suggesting the existence of additional compensatory mutations. The mutant aconitase appears to be a functional knockout with lower activity and expression than wild-type aconitase. Transcriptome sequencing (RNA-seq) analysis of FA19 penA41 acnB G348D revealed a large set of upregulated genes involved in carbon and energy metabolism. We conclude that compensatory mutations can be selected in Cro r gonococcal strains that increase metabolism to ameliorate their fitness deficit. IMPORTANCE The emergence of ceftriaxone-resistant (Cro r ) Neisseria gonorrhoeae has led to the looming threat of untreatable gonorrhea. Whether Cro resistance is likely to spread can be predicted from studies that compare the relative fitnesses of

  6. Gonorrhoea and gonococcal antimicrobial resistance surveillance networks in the WHO European Region, including the independent countries of the former Soviet Union.

    Science.gov (United States)

    Unemo, Magnus; Ison, Catherine A; Cole, Michelle; Spiteri, Gianfranco; van de Laar, Marita; Khotenashvili, Lali

    2013-12-01

    Antimicrobial resistance (AMR) in Neisseria gonorrhoeae has emerged for essentially all antimicrobials following their introduction into clinical practice. During the latest decade, susceptibility to the last remaining options for antimicrobial monotherapy, the extended-spectrum cephalosporins (ESC), has markedly decreased internationally and treatment failures with these ESCs have been verified. In response to this developing situation, WHO and the European Centre for Disease Prevention and Control (ECDC) have published global and region-specific response plans, respectively. One main component of these action/response plans is to enhance the surveillance of AMR and treatment failures. This paper describes the perspectives from the diverse WHO European Region (53 countries), including the independent countries of the former Soviet Union, regarding gonococcal AMR surveillance networks. The WHO European Region has a high prevalence of resistance to all previously recommended antimicrobials, and most of the first strictly verified treatment failures with cefixime and ceftriaxone were also reported from Europe. In the European Union/European Economic Area (EU/EEA), the European gonococcal antimicrobial surveillance programme (Euro-GASP) funded by the ECDC is running. In 2011, the Euro-GASP included 21/31 (68%) EU/EEA countries, and the programme is further strengthened annually. However, in the non-EU/EEA countries, internationally reported and quality assured gonococcal AMR data are lacking in 87% of the countries and, worryingly, appropriate support for establishment of a GASP is still lacking. Accordingly, national and international support, including political and financial commitment, for gonococcal AMR surveillance in the non-EU/EEA countries of the WHO European Region is essential.

  7. High-Throughput Testing of Urogenital and Extragenital Specimens for Detection of Chlamydia Trachomatis and Neisseria Gonorrhoeae with Cobas® CT/NG.

    Science.gov (United States)

    Marlowe, Elizabeth M; Hardy, David; Krevolin, Mark; Gohl, Peter; Bertram, Alexander; Arcenas, Rodney; Seiverth, Britta; Schneider, Tanja; Liesenfeld, Oliver

    2017-09-01

    We compared the analytical and clinical performance of cobas ® CT/NG for use on the Cobas ® 6800/8800 Systems with the Cobas ® 4800 CT/NG Test from urogenital and extragenital specimens in over 12,000 specimens from both male and female subjects in Germany and the United States. The analytical sensitivity was ≤40 EB/ml for Chlamydia trachomatis (CT) and ≤1 CFU/ml for Neisseria gonorrhoeae (NG). Using clinical specimens, the overall percent agreement with the Cobas ® 4800 CT/NG Test was >98.5%. Across urogenital specimens, there were 93 discrepant specimens; 76 (93.8%) of 81 CT discrepant specimens were 6800+/4800- and 10 (83.3%) of 12 NG discrepant specimens were 6800+/4800-. Sequencing verified CT results for 45 (61.6%) of 73 samples positive by 6800 and 1 (20%) of 5 positive by 4800. Similarly, 7 (70.0%) of 10 NG samples positive by 6800 and 1 of 2 positive by 4800 were confirmed by sequencing. Among discrepant extragenital specimens (all 6800+/4800-), 7 (50%) of 14 oropharyngeal and 23 (76.7%) of 30 anorectal CT discordant samples were confirmed as CT positive by sequencing; all 8 anorectal and 20 (90.9%) of 22 oropharyngeal NG discordant results were also confirmed as NG positive. In conclusion, Cobas ® CT/NG for use on the Cobas ® 6800/8800 Systems provides high-throughput automated solutions for sexually transmitted infection (STI) screening programs.

  8. In Vivo-Selected Compensatory Mutations Restore the Fitness Cost of Mosaic penA Alleles That Confer Ceftriaxone Resistance in Neisseria gonorrhoeae

    Directory of Open Access Journals (Sweden)

    Leah R. Vincent

    2018-04-01

    Full Text Available Resistance to ceftriaxone in Neisseria gonorrhoeae is mainly conferred by mosaic penA alleles that encode penicillin-binding protein 2 (PBP2 variants with markedly lower rates of acylation by ceftriaxone. To assess the impact of these mosaic penA alleles on gonococcal fitness, we introduced the mosaic penA alleles from two ceftriaxone-resistant (Cror clinical isolates (H041 and F89 into a Cros strain (FA19 by allelic exchange and showed that the resultant Cror mutants were significantly outcompeted by the Cros parent strain in vitro and in a murine infection model. Four Cror compensatory mutants of FA19 penA41 were isolated independently from mice that outcompeted the parent strain both in vitro and in vivo. One of these compensatory mutants (LV41C displayed a unique growth profile, with rapid log growth followed by a sharp plateau/gradual decline at stationary phase. Genome sequencing of LV41C revealed a mutation (G348D in the acnB gene encoding the bifunctional aconitate hydratase 2/2 methylisocitrate dehydratase. Introduction of the acnBG348D allele into FA19 penA41 conferred both a growth profile that phenocopied that of LV41C and a fitness advantage, although not as strongly as that exhibited by the original compensatory mutant, suggesting the existence of additional compensatory mutations. The mutant aconitase appears to be a functional knockout with lower activity and expression than wild-type aconitase. Transcriptome sequencing (RNA-seq analysis of FA19 penA41 acnBG348D revealed a large set of upregulated genes involved in carbon and energy metabolism. We conclude that compensatory mutations can be selected in Cror gonococcal strains that increase metabolism to ameliorate their fitness deficit.

  9. Rapid change in the ciprofloxacin resistance pattern among Neisseria gonorrhoeae strains in Nuuk, Greenland: time to reconsider preventive and treatment strategies.

    Science.gov (United States)

    Rolskov, Anne Skjerbæk; Bjorn-Mortensen, Karen; Mulvad, Gert; Poulsen, Peter; Jensen, Jørgen Skov; Pedersen, Michael Lynge

    2015-01-01

    Sexually transmitted infections (STIs), including infections with Neisseria gonorrhoeae (GC), are highly incident in Greenland. Since January 2011, GC testing has been performed on urine with nucleic acid amplification tests (NAATs) by strand displacement amplification (Becton Dickinson ProbeTec). Monitoring of GC antibiotic susceptibility by culture was introduced in Nuuk in 2012. Until 2014, no cases of ciprofloxacin-resistant GC strains were reported. In this paper, we report the finding of ciprofloxacin-resistant GC and describe the most recent incidence of GC infections in Greenland. The number of urine NAATs and culture-positive swabs from January to October 2014 were obtained from the Central Laboratory at Queens Ingrid's Hospital in Nuuk and stratified on gender, place and period of testing. Incidence rates were estimated as number of urine NAAT * (12/10) per 100,000 inhabitants. Men in Nuuk with a positive NAAT for GC were encouraged to provide a urethral swab for culture and susceptibility testing. From January to October 2014, a total of 5,436 urine GC NAATs were performed on patients from Nuuk and 9,031 from the rest of Greenland. Of these, 422 (8%) and 820 (9%) were positive, respectively. From January to August, 6 (15%) cultures from Nuuk were ciprofloxacin resistant while in September and October, 26 (59%) were ciprofloxacin resistant (presistance. GC incidence in Nuuk was 3,017 per 100,000 inhabitants per year, compared to 2,491 per 100,000 inhabitants per year in the rest of Greenland. Within a short period, a rapid and dramatic change in ciprofloxacin susceptibility among GC strains isolated in Nuuk was documented and recommendation for first line treatments has changed. Continued monitoring and rethinking of primary and secondary preventive initiatives is highly recommended in this high GC incidence setting.

  10. Prevalence of Chlamydia trachomatis/Neisseria gonorrhoeae and human papilloma virus among women-at risk in the Aegian region of Turkey, and their knowledge about HIV/AIDS.

    Science.gov (United States)

    Gazi, H; Surucuoglu, S; Yolasigmaz, G; Sen, M; Akcali, S; Dinc, G; Teker, A; Sanlidag, T; Koroğlu, G

    2008-09-01

    The aim of this study was to determine the prevalence of selected sexually transmitted diseases (STDs) and the level of knowledge and attitudes regarding HIV/AIDS among Turkish brothel based sex-workers (SWs). A pre-designed questionnaire was administered to 199 SWs to obtain their sexual behaviours and their level of knowledge of HIV/AIDS. The specimens collected for C trachomatis/N gonorrhoeae and human papillomavirus (HPV) were tested using Gen-Probe PACE 2 and HPV-screening assays, respectively. Aproximately sixty-seven per cent of the SWs knew that condoms afforded protection against HIV/AIDS and 62% reported continued use of condoms. Although most of the SWs had heard about HIV/AIDS, thorough knowledge of transmission and prevention was lacking. The overall estimated rates for C trachomatis/N gonorrhoeae and HPV were 18.6% and 9.7%, respectively. There is a need for further studies to generate more data on the prevalence of STDs and the knowledge of STDs in this population.

  11. Association between treatment for gonorrhoea and chlamydia and lower condom use in a cross-sectional study of female sex workers in southern India.

    Science.gov (United States)

    Legendre-Dugal, Marianne; Bradley, Janet; Rajaram, Subramanian Potty; Lowndes, Catherine M; Ramesh, Banadakoppa M; Washington, Reynold; Moses, Stephen; Blanchard, James; Alary, Michel

    2016-05-18

    To assess whether having received grey packets containing treatment for gonorrhoea and chlamydia was associated with condom use among female sex workers (FSWs) in 5 districts of southern India covered by the Avahan programme where both periodic presumptive treatment (PPT) and syndromic management were used to control these sexually transmitted infections (STIs) among FSWs. Cross-sectional study of FSWs recruited in the field in 5 districts of southern India (Bangalore, Belgaum, Bellary, Guntur and Mumbai) in 2006-2007. 1378 self-identified FSWs out of 1442 were approached to participate in the study (participation rate: 95.6%). The only exclusion criterion was to be aged <18 years. Consistent condom use (CCU) with new or occasional clients, and with the most recent repeat client as assessed using a questionnaire administered through face-to-face interviews. Using the Poisson regression to model the association between the number of grey packets received in the past 3-12 months and reported CCU, adjusting for factors associated with condom use and other potential confounders in our data, CCU was lowest among FSWs who had received ≥3 grey packets in the past 3-12 months with their new or occasional clients (adjusted prevalence ratio (APR): 0.70, 95% CI 0.57 to 0.84, p<0.001) and with the most recent repeat client (APR 0.63, 95% CI 0.51 to 0.78, p<0.001). Tests for trends showed that CCU with both types of clients decreased with the number of grey packets received (p<0.001). Since we could not distinguish grey packets used for PPT from those given for syndromic management, these results could be either due to a perception of protection conferred by PPT or by the fact that inconsistent condom users are more at risk for STIs. Further research on the potential disinhibiting effect of PPT is warranted. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

  12. Direct Democracy

    DEFF Research Database (Denmark)

    Beramendi, Virginia; Ellis, Andrew; Kaufman, Bruno

    While many books on direct democracy have a regional or national approach, or simply focus on one of the many mechanisms associated with direct democracy, this Handbook delves into a global comparison of direct democracy mechanisms, including referendums, citizens' initiatives, agenda initiatives...... learned. In addition, the uniquely comprehensive world survey outlines direct democracy provisions in 214 countries and territories and indicates which, if any, of these provisions are used by each country or territory at both the national and sub-national levels. Furthermore, the world survey includes...

  13. Directing 101.

    Science.gov (United States)

    Pintoff, Ernest

    Providing an introduction to anyone considering directing as a field of study or career, this book takes a broad look at the process of directing and encourages students and professionals alike to look outside of the movie industry for inspiration. Chapters in the book discuss selecting and acquiring material; budgeting and financing; casting and…

  14. Cross-sectional study to evaluate Trichomonas vaginalis positivity in women tested for Neisseria gonorrhoeae and Chlamydia trachomatis, attending genitourinary medicine and primary care clinics in Bristol, South West England.

    Science.gov (United States)

    Nicholls, Jane E; Turner, Katy M E; North, Paul; Ferguson, Ralph; May, Margaret T; Gough, Karen; Macleod, John; Muir, Peter; Horner, Patrick J

    2018-03-01

    Highly sensitive, commercial nucleic acid amplification tests (NAAT) for Trichomonas vaginalis have only recently been recommended for use in the UK. While testing for T. vaginalis is routine in symptomatic women attending genitourinary medicine (GUM) clinics, it is rare in asymptomatic women or those attending primary care. The aim of this study was to evaluate the positivity of T. vaginalis using a commercial NAAT, in symptomatic and asymptomatic women undergoing testing for chlamydia and gonorrhoea in GUM and primary care settings. Samples from 9186 women undergoing chlamydia and gonorrhoea testing in South West England between May 2013 and Jan 2015 were also tested for T. vaginalis by NAAT alongside existing tests. T. vaginalis positivity using NAAT was as follows: in GUM 4.5% (24/530, symptomatic) and 1.7% (27/1584, asymptomatic); in primary care 2.7% (94/3499, symptomatic) and 1.2% (41/3573, asymptomatic). Multivariable regression found that in GUM older age, black ethnicity and deprivation were independent risk factors for T. vaginalis infection. Older age and deprivation were also risk factors in primary care. Testing women presenting with symptoms in GUM and primary care using TV NAATs is estimated to cost £260 per positive case diagnosed compared with £716 using current microbiological tests. Aptima TV outperforms existing testing methods used to identify T. vaginalis infection in this population. An NAAT should be used when testing for T. vaginalis in women who present for testing with symptoms in primary care and GUM, based on test performance and cost. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

  15. Directing Creativity

    DEFF Research Database (Denmark)

    Darsø, Lotte; Ibbotson, Piers

    2008-01-01

    In this article we argue that leaders facing complex challenges can learn from the arts, specifically that leaders can learn by examining how theatre directors direct creativity through creative constraints. We suggest that perceiving creativity as a boundary phenomenon is helpful for directing it....... Like leaders, who are caught in paradoxical situations where they have to manage production and logistics simultaneously with making space for creativity and innovation, theatre directors need to find the delicate balance between on one hand renewal of perceptions, acting and interaction...... and on the other hand getting ready for the opening night. We conclude that the art of directing creativity is linked to developing competencies of conscious presence, attention and vigilance, whereas the craft of directing creativity concerns communication, framing and choice....

  16. Direct Heat

    Energy Technology Data Exchange (ETDEWEB)

    Lienau, P J

    1990-01-01

    Potential resources and applications of earth heat in the form of geothermal energy are large. United States direct uses amount to 2,100 MWt thermal and worldwide 8,850 MWt above a reference temperature of 35 degrees Celsius. Space and district heating are the major direct uses of geothermal energy. Equipment employed in direct use projects is of standard manufacture and includes downhole and circulation pumps, transmission and distribution pipelines, heat exchangers and convectors, heat pumps and chillers. Direct uses of earth heat discussed are space and district heating, greenhouse heating and fish farming, process and industrial applications. The economic feasibility of direct use projects is governed by site specific factors such as location of user and resource, resource quality, system load factor and load density, as well as financing. Examples are presented of district heating in Klamath Falls, and Elko. Further developments of direct uses of geothermal energy will depend on matching user needs to the resource, and improving load factors and load density.

  17. Directed polymers versus directed percolation

    Science.gov (United States)

    Halpin-Healy, Timothy

    1998-10-01

    Universality plays a central role within the rubric of modern statistical mechanics, wherein an insightful continuum formulation rises above irrelevant microscopic details, capturing essential scaling behaviors. Nevertheless, occasions do arise where the lattice or another discrete aspect can constitute a formidable legacy. Directed polymers in random media, along with its close sibling, directed percolation, provide an intriguing case in point. Indeed, the deep blood relation between these two models may have sabotaged past efforts to fully characterize the Kardar-Parisi-Zhang universality class, to which the directed polymer belongs.

  18. Direct marketing

    Directory of Open Access Journals (Sweden)

    Čičić Muris

    2002-01-01

    Full Text Available Direct Marketing (DM is usually treated as unworthy activity, with actions at the edge of legality and activities minded cheating. Despite obvious problems regarding ethics and privacy threat, DM with its size, importance and role in a concept of integrated marketing communication deserves respect and sufficient analysis and review

  19. Performance of syndromic management for the detection and treatment of genital Chlamydia trachomatis, Neisseria gonorrhoeae and Trichomonas vaginalis among women attending antenatal, well woman and sexual health clinics in Papua New Guinea: a cross-sectional study.

    Science.gov (United States)

    Vallely, Lisa M; Toliman, Pamela; Ryan, Claire; Rai, Glennis; Wapling, Johanna; Gabuzzi, Josephine; Allen, Joyce; Opa, Christine; Munnull, Gloria; Kaima, Petronia; Kombuk, Benny; Kumbia, Antonia; Kombati, Zure; Law, Greg; Kelly-Hanku, Angela; Wand, Handan; Siba, Peter M; Mola, Glen D L; Kaldor, John M; Vallely, Andrew J

    2017-12-29

    Papua New Guinea (PNG) has among the highest estimated prevalences of genital Chlamydia trachomatis (CT), Neisseria gonorrhoeae (NG) and Trichomonas vaginalis (TV) of any country in the Asia-Pacific region. Diagnosis and treatment of these infections have relied on the WHO-endorsed syndromic management strategy that uses clinical presentation without laboratory confirmation to make treatment decisions. We evaluated the performance of this strategy in clinical settings in PNG. Women attending antenatal (ANC), well woman (WWC) and sexual health (SHC) clinics in four provinces were invited to participate, completed a face-to-face interview and clinical examination, and provided genital specimens for laboratory testing. We estimated the performance characteristics of syndromic diagnoses against combined laboratory diagnoses. 1764 women were enrolled (ANC=765; WWC=614; SHC=385). The prevalences of CT, NG and TV were highest among women attending ANC and SHC. Among antenatal women, syndromic diagnosis of sexually transmitted infection had low sensitivity (9%-21%) and positive predictive value (PPV) (7%-37%), but high specificity (76%-89%) and moderate negative predictive value (NPV) (55%-86%) for the combined endpoint of laboratory-confirmed CT, NG or TV. Among women attending WWC and SHC, 'vaginal discharge syndrome' had moderate to high sensitivity (72%-78%) and NPV (62%-94%), but low specificity (26%-33%) and PPV (8%-38%). 'Lower abdominal pain syndrome' had low sensitivity (26%-41%) and PPV (8%-23%) but moderate specificity (66%-68%) and high NPV (74%-93%) among women attending WWC, and moderate-high sensitivity (67%-79%) and NPV (62%-86%) but low specificity (26%-28%) and PPV (14%-33%) among SHC attendees. The performance of syndromic management for the detection and treatment of genital chlamydia, gonorrhoea and trichomonas was poor among women in different clinical settings in PNG. New diagnostic strategies are needed to control these infections and to prevent

  20. Direct Reactions

    Energy Technology Data Exchange (ETDEWEB)

    Austern, N. [University of Pittsburgh, Pittsburgh, PA (United States)

    1963-01-15

    In order to give a unified presentation of one point of view, these lectures are devoted only to a detailed development of the standard theories of direct reactions, starting from basic principles. Discussion is given of the present status of the theories, of the techniques used for practical calculation, and of possible future developments. The direct interaction (DI) aspects of a reaction are those which involve only a few of the many degrees of freedom of a nucleus. In fact the minimum number of degrees of freedom which must be involved in a reaction are those required to describe the initial and final channels, and DI studies typically consider these degrees of freedom and no others. Because of this simplicity DI theories may be worked out in painstaking detail. DI processes concern only part of the wave function for a problem. The other part involves complicated excitations of many degrees of freedom, and gives the compound nucleus (CN) effects. While it is extremely interesting to learn how to separate DI and CN effects in an orderly manner, if they are both present in a reaction, no suitable method has yet been found. Instead, current work stresses the kinds of reactions and the kinds of final states in which DI effects dominate and in which CN effects may almost be forgotten. The DI cross-sections which are studied are often extremely large, comparable to elastic scattering cross-sections. (author)

  1. Future direction of direct writing

    Science.gov (United States)

    Kim, Nam-Soo; Han, Kenneth N.

    2010-11-01

    Direct write technology using special inks consisting of finely dispersed metal nanoparticles in liquid is receiving an undivided attention in recent years for its wide range of applicability in modern electronic industry. The application of this technology covers radio frequency identification-tag (RFID-tag), flexible-electronics, organic light emitting diodes (OLED) display, e-paper, antenna, bumpers used in flip-chip, underfilling, frit, miniresistance applications and biological uses, artificial dental applications and many more. In this paper, the authors have reviewed various direct write technologies on the market and discussed their advantages and shortfalls. Emphasis has given on microdispensing deposition write (MDDW), maskless mesoscale materials deposition (M3D), and ink-jet technologies. All of these technologies allow printing various patterns without employing a mask or a resist with an enhanced speed with the aid of computer. MDDW and M3D are capable of drawing patterns in three-dimension and MDDW, in particular, is capable of writing nanoinks with high viscosity. However, it is still far away for direct write to be fully implemented in the commercial arena. One of the hurdles to overcome is in manufacturing conductive inks which are chemically and physically stable, capable of drawing patterns with acceptable conductivity, and also capable of drawing patterns with acceptable adhesiveness with the substrates. The authors have briefly discussed problems involved in manufacturing nanometal inks to be used in various writing devices. There are numerous factors to be considered in manufacturing such inks. They are reducing agents, concentrations, oxidation, compact ability allowing good conductivity, and stability in suspension.

  2. Molecular detection and confirmation of Neisseria gonorrhoeae in urogenital and extragenital specimens using the Abbott CT/NG RealTime assay and an in-house assay targeting the porA pseudogene.

    LENUS (Irish Health Repository)

    Walsh, A

    2011-04-01

    Culture for detection of Neisseria gonorrhoeae (NG) is being replaced by molecular assays, but difficulties are observed with false positive and negatives results, especially for extragenital samples. This study evaluates the Abbott CT\\/NG Real-Time assay and a real-time porA pseudogene assay. Samples (n = 600) from a mixed prevalence Irish population include 164 male urines with corresponding urethral swabs, 58 endocervical swabs, 173 male pharyngeal swabs, 205 male rectal swabs, 36 NG clinical isolates and 26 commensal Neisseria species isolates. There was a 100% concordance between the Abbott CT\\/NG Real-Time and the porA assay. The positivity rate was 1.2%, 1.7%, 8.1% and 5.8% for FVU\\/urethral swabs, endocervical, pharyngeal and rectal swabs, respectively. These results were compared to culture and discrepancies were found with nine pharyngeal and three rectal swabs. Seven of the 12 discrepant positive samples were sequenced and were confirmed "true positives". The sensitivity and specificity of the molecular assays was 100%. The sensitivity of the culture-based testing was 100% for urogenital samples but 36% and 75% for pharyngeal and rectal swabs, respectively. The combined Abbott CT\\/NG and porA assays provide a valuable alternative to culture and also generate a significant increase in the diagnosis of pharyngeal and rectal NG infection.

  3. Test of cure, retesting and extragenital testing practices for Chlamydia trachomatis and Neisseria gonorrhoeae among general practitioners in different socioeconomic status areas: A retrospective cohort study, 2011-2016

    Science.gov (United States)

    van Liere, Geneviève A. F. S.; Cals, Jochen W. L.; Dukers-Muijrers, Nicole H. T. M.

    2018-01-01

    Background For Chlamydia trachomatis (CT), a test of cure (TOC) within 3–5 weeks is not recommended. International guidelines differ in advising a Neisseria gonorrhoeae (NG) TOC. Retesting CT and NG positives within 3–12 months is recommended in international guidelines. We assessed TOC and retesting practices including extragenital testing in general practitioner (GP) practices located in different socioeconomic status (SES) areas to inform and optimize local test practices. Methods Laboratory data of 48 Dutch GP practices between January 2011 and July 2016 were used. Based on a patient’s first positive CT or NG test, the proportion of TOC (TOC and 24% had a retest at the GP practice. GP practices in low SES areas were more likely to perform a CT TOC (OR:1.8;95%CI:1.1–3.1). Younger patients (TOC (OR:1.6;95%CI:1.0–2.4). For CT (n = 622), 2.4% had a TOC and 6.1% had a retest at another STI care provider. For NG (n = 73), 25% had a TOC and 15% had a retest at the GP practice. For NG (n = 73), 2.7% had a TOC and 12.3% had a retest at another STI care provider. In only 0.3% of the consultations patients were tested on extragenital sites. Conclusion Almost 20% of the patients returned for a CT TOC, especially at GP practices in low SES areas. For NG, 1 out of 4 patients returned for a TOC. Retesting rates were low for both CT (24%) and NG (15%), (re)infections including extragenital infections may be missed. Efforts are required to focus TOC and increase retesting practices of GPs in order to improve CT/NG control. PMID:29538469

  4. Sexual partner characteristics and incident rectal Neisseria gonorrhoeae and Chlamydia trachomatis infections among gay men and other men who have sex with men (MSM): a prospective cohort in Abuja and Lagos, Nigeria.

    Science.gov (United States)

    Ramadhani, Habib O; Liu, Hongjie; Nowak, Rebecca G; Crowell, Trevor A; Ndomb, Teclaire; Gaydos, Charlotte; Peel, Sheila; Ndembi, Nicaise; Baral, Stefan D; Ake, Julie; Charurat, Man E

    2017-08-01

    STIs including Neisseria gonorrhoeae (NG) and Chlamydia trachomatis (CT) potentiate HIV acquisition and transmission especially among gay men and other men who have sex with men (MSM). We investigated the influence of sexual network composition on incident rectal NG and/or CT infections among Nigerian MSM. TRUST/RV368 is a cohort of MSM recruited using respondent-driven sampling at trusted community centres in Abuja and Lagos, Nigeria. MSM respondents (egos) provided STI risk factors and demographic information for up to five of their most recent sexual partners (alters) within their sexual networks. Egos were tested for HIV, NG and CT every 3 months. Log-binomial regression was used to assess associations between alter characteristics and incident NG and/or CT. Between March 2013 and October 2015, 492 MSM were longitudinally screened for STIs, of which 28.0% (n=138) were positive for incident rectal STI (61 NG only, 42 CT only and 35 NG and CT). Among egos, condom use was associated with STIs (half of the time vs never (adjusted risk ratio (aRR) 0.5; 95% CI 0.3 to 0.8), always/almost always vs never (aRR 0.7; 95% CI 0.5 to 1.0)). Incident STIs were associated with having a younger alter ≤19 versus 30 years (aRR 0.6; 95% CI 0.4 to 1.0), HIV infection (aRR 1.5; 95% CI 1.1 to 2.0) and engaging in sex under the influence of alcohol (aRR 1.4 95% CI 1.1 to 1.7) among regular alters and age ≤19 versus 30 years (aRR 0.3; 95% CI 0.2 to 0.6), HIV infection (aRR 1.4; 95% CI 1.1 to 1.8) and engaging in sex under the influence of alcohol (aRR 1.2 95% CI 1.0 to 1.4) among casual alters. Given the centrality of sexual partner characteristics as risks for incident STIs among Nigerian MSM, there is a need to move beyond individual interventions and syndromic surveillance and get 'out there' in the STI management. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

  5. “I Do Feel Like a Scientist at Times”: A Qualitative Study of the Acceptability of Molecular Point-Of-Care Testing for Chlamydia and Gonorrhoea to Primary Care Professionals in a Remote High STI Burden Setting

    Science.gov (United States)

    Natoli, Lisa; Guy, Rebecca J.; Shephard, Mark; Causer, Louise; Badman, Steven G.; Hengel, Belinda; Tangey, Annie; Ward, James; Coburn, Tony; Anderson, David; Kaldor, John; Maher, Lisa

    2015-01-01

    Background Point-of-care tests for chlamydia (CT) and gonorrhoea (NG) could increase the uptake and timeliness of testing and treatment, contribute to improved disease control and reduce reproductive morbidity. The GeneXpert (Xpert CT/NG assay), suited to use at the point-of-care, is being used in the TTANGO randomised controlled trial (RCT) in 12 remote Australian health services with a high burden of sexually transmissible infections (STIs). This represents the first ever routine use of a molecular point-of-care diagnostic for STIs in primary care. The purpose of this study was to explore the acceptability of the GeneXpert to primary care staff in remote Australia. Methods In-depth qualitative interviews were conducted with 16 staff (registered or enrolled nurses and Aboriginal Health Workers/Practitioners) trained and experienced with GeneXpert testing. Interviews were digitally-recorded and transcribed verbatim prior to content analysis. Results Most participants displayed positive attitudes, indicating the test was both easy to use and useful in their clinical context. Participants indicated that point-of-care testing had improved management of STIs, resulting in more timely and targeted treatment, earlier commencement of partner notification, and reduced follow up efforts associated with client recall. Staff expressed confidence in point-of-care test results and treating patients on this basis, and reported greater job satisfaction. While point-of-care testing did not negatively impact on client flow, several found the manual documentation processes time consuming, suggesting that improved electronic connectivity and test result transfer between the GeneXpert and patient management systems could overcome this. Managing positive test results in a shorter time frame was challenging for some but most found it satisfying to complete episodes of care more quickly. Conclusions In the context of a RCT, health professionals working in remote primary care in Australia

  6. "I Do Feel Like a Scientist at Times": A Qualitative Study of the Acceptability of Molecular Point-Of-Care Testing for Chlamydia and Gonorrhoea to Primary Care Professionals in a Remote High STI Burden Setting.

    Directory of Open Access Journals (Sweden)

    Lisa Natoli

    Full Text Available Point-of-care tests for chlamydia (CT and gonorrhoea (NG could increase the uptake and timeliness of testing and treatment, contribute to improved disease control and reduce reproductive morbidity. The GeneXpert (Xpert CT/NG assay, suited to use at the point-of-care, is being used in the TTANGO randomised controlled trial (RCT in 12 remote Australian health services with a high burden of sexually transmissible infections (STIs. This represents the first ever routine use of a molecular point-of-care diagnostic for STIs in primary care. The purpose of this study was to explore the acceptability of the GeneXpert to primary care staff in remote Australia.In-depth qualitative interviews were conducted with 16 staff (registered or enrolled nurses and Aboriginal Health Workers/Practitioners trained and experienced with GeneXpert testing. Interviews were digitally-recorded and transcribed verbatim prior to content analysis.Most participants displayed positive attitudes, indicating the test was both easy to use and useful in their clinical context. Participants indicated that point-of-care testing had improved management of STIs, resulting in more timely and targeted treatment, earlier commencement of partner notification, and reduced follow up efforts associated with client recall. Staff expressed confidence in point-of-care test results and treating patients on this basis, and reported greater job satisfaction. While point-of-care testing did not negatively impact on client flow, several found the manual documentation processes time consuming, suggesting that improved electronic connectivity and test result transfer between the GeneXpert and patient management systems could overcome this. Managing positive test results in a shorter time frame was challenging for some but most found it satisfying to complete episodes of care more quickly.In the context of a RCT, health professionals working in remote primary care in Australia found the GeneXpert highly

  7. Xanthomonas campestris lipooligosaccharides trigger innate immunity and oxidative burst in Arabidopsis

    NARCIS (Netherlands)

    Proietti, S; Giangrande, C; Amoresano, A; Pucci, P; Molinaro, A; Bertini, L; Caporale, C; Caruso, C

    2014-01-01

    Plants lack the adaptive immunity mechanisms of jawed vertebrates, so they rely on innate immune responses to defense themselves from pathogens. The plant immune system perceives the presence of pathogens by recognition of molecules known as pathogen-associated molecular patterns (PAMPs). PAMPs have

  8. Incidence of repeat testing and diagnoses of Chlamydia trachomatis and Neisseria gonorrhoea in swingers, homosexual and heterosexual men and women at two large Dutch STI clinics, 2006-2013.

    Science.gov (United States)

    Dukers-Muijrers, Nicole H T M; van Rooijen, Martijn S; Hogewoning, Arjan; van Liere, Genevieve A F S; Steenbakkers, Mieke; Hoebe, Christian J P A

    2017-09-01

    Swingers, that is, heterosexuals who as a couple have sex with others, including group sex and bisexual behaviour, are an older-aged risk group for STIs. Here, we report on their repeat testing (reattendance) and STI yield compared with other heterosexuals and men who have sex with men (MSM, homosexual men) at two Dutch STI clinics. Swingers are routinely (since 2006, South Limburg, registration-completeness: 99%) or partially (since 2010, Amsterdam, registration-completeness: 20%) included in the clinic patient registries. Data (retrospective cohort) are analysed to assess incidence (per 100 person-years (PY)) of reattendance and STI ( Chlamydia trachomatis (CT) and/or Neisseria gonorrhoeae (NG)) and associated factors calculating HRs. In South Limburg 7714 and in Amsterdam 2070 swinger consultations were identified. Since 2010, swingers' incidence of reattendance was 48-57/100 PY. Incidence was lower in MSM (30-39/100 PY, HR 0.56; 95% CI 0.51 to 0.61, South Limburg; HR 0.88; 95% CI 0.80 to 0.96, Amsterdam), heterosexual men (8-14/100 PY, HR 0.16; 95% CI 0.15 to 0.17, South Limburg; HR 0.33; 95% CI 0.30 to 0.36, Amsterdam) and women (13-20/100 PY, HR 0.56; 95% CI 0.51 to 0.61, South Limburg; HR 0.46; 95% CI 0.42 to 0.51, Amsterdam). Swingers' STI incidence at reattendance was 11-12/100 PY. Incidence was similar in heterosexual men (14-15/100 PY; HR 1.19; 95% CI 0.90 to 1.57, South Limburg; HR 1.20; 95% CI 0.91 to 1.59, Amsterdam) and women (12-14/100 PY; HR 1.14; 95% CI 0.88 to 1.49, South Limburg; HR 0.98; 95% CI 0.74 to 1.29, Amsterdam) and higher in MSM (18-22/100 PY; HR 1.59; 95% CI 1.19 to 2.12, South Limburg; HR 1.80; 95% CI 1.36 to 2.37, Amsterdam). Risk factors for STI incidence were partner-notified (contact-tracing), symptoms and previous STI. Swingers' positivity at any clinic attendance was 3-4% for NG (ie, higher than other heterosexuals) and 6-8% for CT (ie, lower than heterosexuals overall but higher than older heterosexuals

  9. Direct selling particularities

    OpenAIRE

    Greifová, Daniela

    2009-01-01

    Bachelor thesis is focused on the parcularities of direct selling, self regulation of this industry, multi-level marketing which is the most used sales method in the field of direct selling. The part of the thesis is dedicated to the issue of customer psychology that is very important for achieving success in direct selling. Main goals are to provide readers with the general view of direct selling and analysis of growing possibilities of the industry in the future.

  10. Directed Energy Weapons

    Science.gov (United States)

    2007-12-01

    future business . In defense systems, the key to future business is the existence of funded programs. Military commanders understand the lethality and...directed energp capabilities that can provide visibiliy into the likey futur business case for sustaining directed energy industry capabilities...the USD (I) staff to be afocalpointfor advocating improvement in all dimensions of directed energy intelligence. - The Director, Defense Inteligence

  11. Directed Energy Anechoic Chamber

    Data.gov (United States)

    Federal Laboratory Consortium — The Directed Energy Anechoic Chamber comprises a power anechoic chamber and one transverse electromagnetic cell for characterizing radiofrequency (RF) responses of...

  12. Records Management Directive

    Data.gov (United States)

    Office of Personnel Management — The Office of Personnel Management (OPM) Records Management Directive provides guidelines for the management of OPM records, and identifies the records management...

  13. Direct Conversion of Energy.

    Science.gov (United States)

    Corliss, William R.

    This publication is one of a series of information booklets for the general public published by the United States Atomic Energy Commission. Direct energy conversion involves energy transformation without moving parts. The concepts of direct and dynamic energy conversion plus the laws governing energy conversion are investigated. Among the topics…

  14. Decisions Concerning Directional Dependence

    Science.gov (United States)

    von Eye, Alexander; DeShon, Richard P.

    2012-01-01

    In this rejoinder, von Eye and DeShon discuss the decision strategies proposed in their original article ("Directional Dependence in Developmental Research," this issue), as well as the ones proposed by the authors of the commentary (Pornprasertmanit and Little, "Determining Directional Dependency in Causal Associations," this issue). In addition,…

  15. Directionality of dog vocalizations

    Science.gov (United States)

    Frommolt, Karl-Heinz; Gebler, Alban

    2004-07-01

    The directionality patterns of sound emission in domestic dogs were measured in an anechoic environment using a microphone array. Mainly long-distance signals from four dogs were investigated. The radiation pattern of the signals differed clearly from an omnidirectional one with average differences in sound-pressure level between the frontal and rear position of 3-7 dB depending from the individual. Frequency dependence of directionality was shown for the range from 250 to 3200 Hz. The results indicate that when studying acoustic communication in mammals, more attention should be paid to the directionality pattern of sound emission.

  16. FAA Directives System

    Science.gov (United States)

    1992-08-26

    Consistent with the Federal Aviation Administration's mission to foster a safe, : secure, and efficient aviation system is the need for an effective and efficient : process for communitcating policy and procedures. The FAA Directives System : provide...

  17. Assessing directionality in context

    African Journals Online (AJOL)

    Kate H

    In support of first-language interpreting as the exclusive interpreting direction, ... some light on the possible interaction between two independent variables, .... the “local context” refers to the setting, genre, participants, and aims of the event.

  18. Directed line liquids

    International Nuclear Information System (INIS)

    Kamien, R.D.

    1992-01-01

    This thesis is devoted to the study of ensembles of dense directed lines. These lines are principally to be thought of as polymers, though they also have the morphology of flux lines in high temperature superconductors, strings of colloidal spheres in electrorheological fluids and the world lines of quantum mechanical bosons. The authors discuss how directed polymer melts, string-like formations in electrorheological and ferro-fluids, flux lines in high temperature superconductors and the world lines of quantum mechanical bosons all share similar descriptions. They study a continuous transition in all of these systems, and then study the critical mixing properties of binary mixtures of directed polymers through the renormalization group. They predict the exponents for a directed polymer blend consolute point and a novel two-phase superfluid liquid-gas critical point

  19. The ''energy tax'' directive

    International Nuclear Information System (INIS)

    Anon.

    2003-01-01

    As Austria dropped its reservation, U.E. Economics and Finance Ministers gave, on 20 March at Brussels, their political agreement to the proposed Directive on a Community framework for the taxation of energy products. (author)

  20. Directed GF-spaces

    Directory of Open Access Journals (Sweden)

    F.G. Arenas

    2001-10-01

    Full Text Available In this paper we introduce the concept of directed fractal structure, which is a generalization of the concept of fractal structure (introduced by the authors. We study the relation with transitive quasiuniformities and inverse limits of posets. We define the concept of GF-compactification and apply it to prove that the Stone-Cech compactification can be obtained as the GF-compactification of the directed fractal structure associated to the Pervin quasi-uniformity.

  1. Utility of Direct Fluorescent Antibody Test for detection of Chlamydia trachomatis and its detection in male patients with non gonococcal urethritis in New Delhi

    Directory of Open Access Journals (Sweden)

    Agrawal S

    2003-03-01

    Full Text Available The purpose of this study was assessment of prevalence of Chlamydia trachomatis and utility of Direct Fluorescent Antibody (DFA test for its detection in male patients with non gonococcal urethritis in New Delhi , India Thirty male patients with symptoms of dysuria showing polymorphs in their gram stained urethral smears with no evidence of Neisseria gonorrhoeae, and negative for Trichomonas vaginalis and Candida albicans by wet mount were subjected to DFA test for detection of C. trachomatis in urethral samples. Microscopic examination of gram stained urethral smears revealed 5-7 polymorphs / HPF in 90% of the patients. Evidence of C. trachomatis with DFA (MicroTrak was detected in 11 cases (36.67% when a cut off of 10 elementary bodies was considered essential. It is concluded that C. trachomatis is an important cause of non gonococcal urethritis in male patients in New Delhi and DFA test is a useful diagnostic tool in its detection. Where facilities are not available for its detection antichlamydial therapy should be recommended emperically.

  2. Directed network modules

    International Nuclear Information System (INIS)

    Palla, Gergely; Farkas, Illes J; Pollner, Peter; Derenyi, Imre; Vicsek, Tamas

    2007-01-01

    A search technique locating network modules, i.e. internally densely connected groups of nodes in directed networks is introduced by extending the clique percolation method originally proposed for undirected networks. After giving a suitable definition for directed modules we investigate their percolation transition in the Erdos-Renyi graph both analytically and numerically. We also analyse four real-world directed networks, including Google's own web-pages, an email network, a word association graph and the transcriptional regulatory network of the yeast Saccharomyces cerevisiae. The obtained directed modules are validated by additional information available for the nodes. We find that directed modules of real-world graphs inherently overlap and the investigated networks can be classified into two major groups in terms of the overlaps between the modules. Accordingly, in the word-association network and Google's web-pages, overlaps are likely to contain in-hubs, whereas the modules in the email and transcriptional regulatory network tend to overlap via out-hubs

  3. Directivity of singers

    Science.gov (United States)

    Jers, Harald

    2005-09-01

    Studies of acoustical balance between singers within a choir by means of room acoustical measurements have shown that the directional sound propagation of the source is important. For this reason the directivity of female and male singers for different vowels has been measured in this investigation. Measurements of a pilot study and some first measurements in 1998 have been supplemented with new measurements and an enhanced setup. A special measurement setup with reference and recording microphones was used to collect the directivity data. A resolution of 10 deg for azimuth and elevation angle was obtained. The results will be shown in 3D spherical plots with frequency adjustments in semitones from 80 to 8000 Hz. The measurements are compared to an artificial singer's directivity, and the influence of a sheet music binder in front of a singer will be shown. The results give information on the directivity of singers and are relevant for the prediction of self-to-other-ratios that result from placement and formation aspects within a choir.

  4. Estimating directional epistasis

    Science.gov (United States)

    Le Rouzic, Arnaud

    2014-01-01

    Epistasis, i.e., the fact that gene effects depend on the genetic background, is a direct consequence of the complexity of genetic architectures. Despite this, most of the models used in evolutionary and quantitative genetics pay scant attention to genetic interactions. For instance, the traditional decomposition of genetic effects models epistasis as noise around the evolutionarily-relevant additive effects. Such an approach is only valid if it is assumed that there is no general pattern among interactions—a highly speculative scenario. Systematic interactions generate directional epistasis, which has major evolutionary consequences. In spite of its importance, directional epistasis is rarely measured or reported by quantitative geneticists, not only because its relevance is generally ignored, but also due to the lack of simple, operational, and accessible methods for its estimation. This paper describes conceptual and statistical tools that can be used to estimate directional epistasis from various kinds of data, including QTL mapping results, phenotype measurements in mutants, and artificial selection responses. As an illustration, I measured directional epistasis from a real-life example. I then discuss the interpretation of the estimates, showing how they can be used to draw meaningful biological inferences. PMID:25071828

  5. Direct reading dosimeter

    International Nuclear Information System (INIS)

    Thomson, I.

    1985-01-01

    This invention is a direct reading dosimeter which is light, small enough to be worn on a person, and measures both dose rates and total dose. It is based on a semiconductor sensor. The gate threshold voltage change rather than absolute value is measured and displayed as a direct reading of the dose rate. This is effected by continuously switching the gate of an MOS transistor from positive to negative bias. The output can directly drive a digital readout or trigger an audible alarm. The sensor device can be a MOSFET, bipolar transistor, or MOSFET capacitor which has its electrical characteristics change due to the trapped charge in the insulating layer of the device

  6. The direction of time

    CERN Document Server

    Reichenbach, Hans

    1999-01-01

    Ever a source of philosophical conjecture and debate, the concept of time represents the beating heart of physics. This final work by the distinguished physicist Hans Reichenbach represents the culmination and integration of a lifetime's philosophical contributions and inquiries into the analysis of time. The result is an outstanding overview of such qualitative, or topological, attributes of time as order and direction.Beginning with a discussion of the emotive significance of time, Reichenbach turns to an examination of the time order of mechanics, the time direction of thermodynamics and m

  7. Incretin secretion: direct mechanisms

    DEFF Research Database (Denmark)

    Balk-Møller, Emilie; Holst, Jens Juul; Kuhre, Rune Ehrenreich

    2014-01-01

    The incretin hormones glucose-dependent insulinotropic polypeptide (GIP) and glucagon-like peptide 1 (GLP-1) are secreted from gastro-intestinal K- and L-cells, respectively, and play an important role in post-prandial blood glucose regulation. They do this by direct stimulation of the pancreatic β...... enzyme responsible for incretin degradation (dipeptidyl peptidase-4) is inhibited (drugs are already on the market) while the secretion of endogenous GLP-1 secretion is stimulated at the same time may prove particularly rewarding. In this section we review current knowledge on the mechanisms for direct...

  8. Direct Sulfation of Limestone

    DEFF Research Database (Denmark)

    Hu, Guilin; Dam-Johansen, Kim; Wedel, Stig

    2007-01-01

    The direct sulfation of limestone was studied in a laboratory fixed-bed reactor. It is found that the direct sulfation of limestone involves nucleation and crystal grain growth of the solid product (anhydrite). At 823 K and at low-conversions (less than about 0.5 %), the influences of SO2, O-2...... and CO2 on the direct sulfation of limestone corresponds to apparent reaction orders of about 0.2, 0.2 and -0.5, respectively. Water is observed to promote the sulfation reaction and increase the apparent reaction orders of SO2 and O-2. The influence of O-2 at high O-2 concentrations (> about 15...... %) becomes negligible. In the temperature interval from 723 K to 973 K, an apparent activation energy of about 104 kJ/mol is observed for the direct sulfation of limestone. At low temperatures and low conversions, the sulfation process is most likely under mixed control by chemical reaction and solid...

  9. Danish directional adverbs:

    DEFF Research Database (Denmark)

    Hovmark, Henrik

    2013-01-01

    Danish directional adverbs (DDA) (for instance op ’up’, ned ’down’, and ud ’out’) are characterized by an important special feature as satellites – they have different forms: a zero-form (ud-Ø), a form with a derivative e-suffix (ud-e), and a third form with a prepositional ad-suffix (‘ wards’). ...

  10. Directional loudness perception

    DEFF Research Database (Denmark)

    Sivonen, Ville Pekka

    developed. The research and modeling of loudness have mainly been concerned with the temporal and spectral aspects of sounds, while the spatial aspects have mostly been overlooked. This PhD thesis investigates the spatial aspects of loudness perception, namely, how does the direction from which a sound...

  11. Direct contamination - seasonality

    International Nuclear Information System (INIS)

    Aarkrog, A.

    1994-01-01

    Direct contamination is the primary pathway to terrestrial vegetation in the first period after an activity release to the atmosphere. All radionuclides are able to be transferred via this pathway. Deposition, interception and retention are the three processes involved in direct contamination of crops. Wet deposition is more important than dry deposition in temperature regions. Resuspension and rainsplash both belong to secondary direct deposition and became evident for e.g. radiocaesium after the Chernobyl accident. Seasonality is the varying response to radioactive contamination of crops according to the time of the year when the contamination occurs. Shortlived radionuclides (as 131 I) and those that mainly enter the foodchain by direct contamination (e.g. 137 Cs) are especially important in this connection. In particular, the contamination of cereal crops is influenced by seasonality. As a result of seasonality the impact of the Chernobyl accident on the radioactive contamination of human diet was for the same deposition density higher in southern than in northern Europe. (orig.)

  12. Direct vision internal urethrotomy

    DEFF Research Database (Denmark)

    Jakobsen, H; Willumsen, H; Søndergaard Jensen, L

    1984-01-01

    During a five-year period, direct vision internal urethrotomy was used for the treatment of urethral strictures in 34 men. After the primary operation the patients were followed for an average period of 29 months (range 3-73 months). During this period 53% of the patients were found to have one...

  13. Direct photon experiments

    International Nuclear Information System (INIS)

    Boeggild, H.

    1986-11-01

    The author reviews the experiments on direct photon production in hadronic collisions. After a description of the experimental methods for the study of such processes he presents some results on differential cross sections and the γ/π 0 ratio in π - p, π + p, pp, and anti pp processes as well as in reactions of π - , π + , and p on carbon. (HSI)

  14. Polymer Directed Protein Assemblies

    Directory of Open Access Journals (Sweden)

    Patrick van Rijn

    2013-05-01

    Full Text Available Protein aggregation and protein self-assembly is an important occurrence in natural systems, and is in some form or other dictated by biopolymers. Very obvious influences of biopolymers on protein assemblies are, e.g., virus particles. Viruses are a multi-protein assembly of which the morphology is dictated by poly-nucleotides namely RNA or DNA. This “biopolymer” directs the proteins and imposes limitations on the structure like the length or diameter of the particle. Not only do these bionanoparticles use polymer-directed self-assembly, also processes like amyloid formation are in a way a result of directed protein assembly by partial unfolded/misfolded biopolymers namely, polypeptides. The combination of proteins and synthetic polymers, inspired by the natural processes, are therefore regarded as a highly promising area of research. Directed protein assembly is versatile with respect to the possible interactions which brings together the protein and polymer, e.g., electrostatic, v.d. Waals forces or covalent conjugation, and possible combinations are numerous due to the large amounts of different polymers and proteins available. The protein-polymer interacting behavior and overall morphology is envisioned to aid in clarifying protein-protein interactions and are thought to entail some interesting new functions and properties which will ultimately lead to novel bio-hybrid materials.

  15. Direct Lending Works.

    Science.gov (United States)

    Riley, Richard W.

    1997-01-01

    In its third year, direct lending is working well for college students and administration. It is a simpler, faster, more efficient way of getting loan funds to students that cuts out financial middlemen. It helps students manage their finances better when repaying loans, promotes competition, stimulates program innovation, leads to greater…

  16. Advanced directives: open issues

    Directory of Open Access Journals (Sweden)

    Gabriella Negrini

    2013-05-01

    Full Text Available BACKGROUND In Italy Advanced directives have not been regulated by law yet. Moreover, there is a confusion of concepts: advanced directives, refusal of treatment, medical futility and euthanasia are not synonymous.DISCUSSION The following aspects are then discussed: object of directives; elapse of time between their expression and their application; knowledge of the directives and their obligatory nature. The refusal of a treatment that can save a person’s life is a critical subject. There are different ethical points of view: according to lay ethics, the patient’s self-determination prevails; the religious viewpoint, instead, says that life is a gift which we cannot dispose of. In any case, the patient will be confronted with the professional autonomy of the doctor. Should the doctor save a patient’s life in any case or should he achieve best clinical practice, in respect of his will? The doctor should interpret the patient’s will but with caution and judgment. An exemption from responsibility should be provided by law for doctors who respect patient’s living will.

  17. Direct oxide reducing method

    International Nuclear Information System (INIS)

    Tokiwai, Moriyasu.

    1995-01-01

    Calcium oxides and magnetic oxides as wastes generated upon direct reduction are subjected to molten salt electrolysis, and reduced metallic calcium and magnesium are separated and recovered. Then calcium and magnesium are used recyclically as the reducing agent upon conducting direct oxide reduction. Even calcium oxides and magnesium oxides, which have high melting points and difficult to be melted usually, can be melted in molten salts of mixed fluorides or chlorides by molten-salt electrolysis. Oxides are decomposed by electrolysis, and oxygen is removed in the form of carbon monoxide, while the reduced metallic calcium and magnesium rise above the molten salts on the side of a cathode, and then separated. Since only carbon monoxide is generated as radioactive wastes upon molten salt electrolysis, the amount of radioactive wastes can be greatly reduced, and the amount of the reducing agent used can also be decreased remarkably. (N.H.)

  18. Direct use in Hawaii

    International Nuclear Information System (INIS)

    Beck, A.G.

    1990-01-01

    This paper reports on a public laboratory, Noi'i O Puna, that was established in Hawaii to support direct use research in 1985, tapping the previously unutilized heat in brines from the HGP-A well. Two rounds of small grants were offered to entrepreneurs. With the closure of the HGP-A power plant in late 1989, Noi'i O Puna is expanding its facilities. When the HGP-A well is back in service, Noi'i O Puna will be able to support additional research and development projects, as well as pre-commercial ventures. Direct use industries, which support existing agricultural activities in the region have good potential

  19. Direct Communication Systems

    OpenAIRE

    Krajačić, Ivan

    2016-01-01

    Today we use numerous methods of direct communications, for which we use a technical term Unified Communications. It is almost impossible to imagine the business world today without Unified Communications, which are improving productivity and reducing costs. The goal of using Unified Communications is to ensure a consistent user experience at any location and any device. Skype for Business, a Microsoft product, is one of the solutions for Unified Communications and is described in this thesis...

  20. Directional borehole antenna - Theory

    International Nuclear Information System (INIS)

    Falk, L.

    1992-02-01

    A directional antenna has been developed for the borehole radar constructed during phase 2 of the Stripa project. The new antenna can determine the azimuth of a strong reflector with an accuracy of about 3 degrees as confirmed during experiments in Stripa, although the ratio of borehole diameter to wavelength is small, about 0.03. The antenna synthesizes the effect of a loop antenna rotating in the borehole from four signals measured in turn by a stationary antenna. These signals are also used to calculate an electric dipole signal and a check sum which is used to examine the function of the system. The theory of directional antennas is reviewed and used to design an antenna consisting of four parallel wires. The radiation pattern of this antenna is calculated using transmission line theory with due regard to polarization, which is of fundamental importance for the analysis of directional data. In particular the multipole expansion of the field is calculated to describe the antenna radiation pattern. Various sources of error, e.g. the effect of the borehole, are discussed and the methods of calibrating the antenna are reviewed. The ambiguity inherent in a loop antenna can be removed by taking the phase of the signal into account. Typical reflectors in rock, e.g. fracture zones an tunnels, may be modelled as simple geometrical structures. The corresponding analysis is described and exemplified on measurements from Stripa. Radar data is nowadays usually analyzed directly on the computer screen using the program RADINTER developed within the Stripa project. An algorithm for automatic estimation of the parameters of a reflector have been tested with some success. The relation between measured radar data and external coordinates as determined by rotational indicators is finally expressed in terms of Euler angles. (au)

  1. Direct hydrocarbon fuel cells

    Science.gov (United States)

    Barnett, Scott A.; Lai, Tammy; Liu, Jiang

    2010-05-04

    The direct electrochemical oxidation of hydrocarbons in solid oxide fuel cells, to generate greater power densities at lower temperatures without carbon deposition. The performance obtained is comparable to that of fuel cells used for hydrogen, and is achieved by using novel anode composites at low operating temperatures. Such solid oxide fuel cells, regardless of fuel source or operation, can be configured advantageously using the structural geometries of this invention.

  2. Future directions for QCD

    International Nuclear Information System (INIS)

    Bjorken, J.D.

    1996-10-01

    New directions for exploring QCD at future high-energy colliders are sketched. These include jets within jets. BFKL dynamics, soft and hard diffraction, searches for disoriented chiral condensate, and doing a better job on minimum bias physics. The new experimental opportunities include electron-ion collisions at HERA, a new collider detector at the C0 region of the TeVatron, and the FELIX initiative at the LHC

  3. Perspective on direct conversion

    Energy Technology Data Exchange (ETDEWEB)

    Lewis, W B

    1963-10-15

    The objective of direct conversion is high electrical output for minimum total cost, and not always high conversion efficiency. The wide range of techniques embracing cryogenics and hot plasma derives from the special requirements of source, environment, and application. Sources include solar and other radiation, nuclear fission and fusion, chemical energy, and heat. Environments and applications range from space vehicles to submarines and from giant power networks to isolated buoys and pocket devices. (auth)

  4. Farm Management: rethinking directions?

    OpenAIRE

    Kemp, David R.; Girdwood, John; Parton, Kevin A.; Charry, Al A.

    2004-01-01

    Farms and farming are major contributors to the world economy, directly responsible for a large part of GDP. These achievements are not trivial and imply that farms are being managed in reasonably effective ways, else agricultural industries would not be sustained. However has the study of Farm Management within Australia made significant contributions to agriculture or lagged in the background. Is it contributing to better Farm Management or merely cataloguing what has happened? Is it leadin...

  5. AngularJS directives

    CERN Document Server

    Vanston, Alex

    2013-01-01

    This book uses a practical, step-by-step approach, starting with how to build directives from the ground up before moving on to creating web applications comprised of multiple modules all working together to provide the best user experience possible.This book is intended for intermediate JavaScript developers who are looking to enhance their understanding of single-page web application development with a focus on AngularJS and the JavaScript MVC frameworks.It is expected that readers will understand basic JavaScript patterns and idioms and can recognize JSON formatted data.

  6. Direct olive oil analysis

    Directory of Open Access Journals (Sweden)

    Peña, F.

    2002-03-01

    Full Text Available The practical impact of “direct analysis” is undeniable as it strong contributes to enhance the so-called productive analytical features such as expeditiousness, reduction of costs and minimisation of risks for the analysts and environment. The main objective is to establish a reliable bypass to the conventional preliminary operations of the analytical process. This paper offers a systematic approach in this context and emphasises the great field of action of direct methodologies in the routine analysis of olive oil. Two main types of methodologies are considered. On the one hand, the direct determination of volatile components is systematically considered. On the other hand, simple procedures to automatically implement the preliminary operations of the oil analysis using simple devices in which the sample is directly introduced with/without a simple dilution are present and discussed.El impacto práctico del análisis directo es tan innegable como que el contribuye decisivamente a mejorar las denominadas características analíticas relacionadas con la productividad como la rapidez, la reducción de costes y la minimización de riesgos para los analistas y el ambiente. El principal objetivo es establecer un adecuado "bypass" a las operaciones convencionales preliminares del proceso analítico. Este artículo ofrece una propuesta sistemática en este contexto y resalta el gran campo de acción de las metodologías directas en los análisis de rutina del aceite de oliva. Se analizan los dos tipos principales de metodologías. Por una lado, se analiza la determinación directa de los compuestos volátiles. Por el otro, se presentan y discuten los procedimientos simples para implementar automáticamente las operaciones preliminares del análisis del aceite usando sistemas simples en los que la muestra se introduce directamente con/sin un dilución simple.

  7. The direct manipulation shell

    International Nuclear Information System (INIS)

    Allen, M.E.; Christiansen, M.

    1992-01-01

    Accelerator controls systems provide parameter display pages which allow the operator to monitor and manipulate selected control points in the system. Display pages are generally implemented as either hand-crafted, purpose-built programs; or by using a specialized display page layout tool. These two methods of display page development exhibit the classic trade-off between functionality vs. ease of implementation. In the Direct Manipulation Shell we approach the process of developing a display page in a manifestly object-oriented manner. This is done by providing a general framework for interactively instantiating and manipulating display objects. (author)

  8. Does direct experience matter?

    DEFF Research Database (Denmark)

    Miralles, Francesc; Giones, Ferran; Gozun, Brian

    2017-01-01

    of being engaged in entrepreneurial behavior on entrepreneurial intention. We aim to shed light on whether the direct experience reinforces an individual’s entrepreneurial intention or reduces it. Building on an extended version of the planned behavior theory, we use the behavioral reasoning theory...... and an individual’s intention by introducing behavioral reasoning theory. These results provide support to initiatives to adapt entrepreneurship promotion efforts to the specific characteristics of the participants.......Entrepreneurial behavior research has used intention models to explain how an individual’s beliefs shape the attitudes and motivations that influence entrepreneurial intention. Nevertheless, as entrepreneurship promotion initiatives become global, it becomes relevant to explore the consequences...

  9. Directions for further research

    DEFF Research Database (Denmark)

    Minsaas, Atle; Psaraftis, Harilaos N.

    2015-01-01

    Green transportation logistics is an area that combines the following: (a) it is relatively new in terms of research carried out thus far, (b) it has become increasingly important for both industry and society, and (c) it is rich in topics for further research, both basic and applied. In this final...... chapter of this book we discuss directions for further research in this area. We do so by taking stock of (1) related recommendations of project SuperGreen, and (2) related activities mainly in European research. Links between research and policy-making as two activities that should go hand in hand...

  10. Directionally Solidified Multifunctional Ceramics

    Science.gov (United States)

    2006-12-01

    Vidrio , Vol. 44 [5] (2005) pp 347 - 352. 9. F. W. Dynys and A. Sayir, "Self Assemble Silicide Architectures by Directional Solidification," Journal...Sociedad Espanola de Ceramica y Vidrio , Vol. 43 [4] (2004) pp 753 - 758. 21. A. Sayir and F. S. Lowery, "Combustion-Resistance of Silicon-Based Ceramics...Espafiola de Cerdmica y Vidrio , Vol. 43 [3], 2004. ISSN-0366-3175-BSCVB9. 14 37. P. Berger, A. Sayir and M. H. Berger, "Nuclear Microprobe using Elastic

  11. Direct access to INIS

    International Nuclear Information System (INIS)

    Zheludev, I.S.; Romanenko, A.G.

    1981-01-01

    Librarians, researchers, and information specialists throughout the world now have the opportunity for direct access to coverage of almost 95% of the world's literature dealing with the peaceful uses of atomic energy and nuclear science. This opportunity has been provided by the International Nuclear Information System (INIS) of the IAEA. INIS, with the voluntary collaboration of more than 60 of the Agency's Member States, maintains a comprehensive, computer-resident data-base, containing the bibliographic details plus informative abstracts of the bulk of the world's literature on nuclear science and technology. Since this data-base is growing at a rate of 75,000 items per year, and already contains more than 500,000 items, it is obviously important to be able to search this collection conveniently and efficiently. The usefulness of this ability is enhanced when other data-bases on related subjects are made available on an information network. During the early 1970s, on-line interrogation of large bibliographic data-bases became the accepted method for searching this type of information resource. Direct interaction between the searcher and the data-base provides quick feed-back resulting in improved literature listings for launching research and development projects. On-line access enables organizations which cannot store a large data-base on their own computer to expand the information resources at their command. Because of these advantages, INIS undertook to extend to interested Member States on-line access to its data-base in Vienna

  12. Direct thermal dyes

    Science.gov (United States)

    Ehlinger, Edward

    1990-07-01

    Direct thermal dyes are members of a class of compounds referred to in the imaging industry as color formers or leuco dyes. The oldest members of that class have simple triarylmethane structures, and have been employed for years in various dyeing applications. More complex triarylmethane compounds, such as phthalides and fluorans, are now used in various imaging systems to produce color. Color is derived from all of these compounds via the same mechanism, on a molecular level. That is, an event of activation produces a highly resonating cationic system whose interaction with incident light produces reflected light of a specific color. The activation event in the case of a direct thermal system is the creation of a melt on the paper involving dye and an acidic developer. The three major performance parameters in a thermal system are background color, image density, and image stability. The three major dye physical parameters affecting thermal performance are chemical constituency, purity, and particle size. Those dyes having the best combination of characteristics which can also be manufactured economically dominate the marketplace. Manufacturing high performance dyes for the thermal market involves multi-step, convergent reaction sequences performed on large scale. Intermediates must be manufactured at the right time, and at the right quality to be useful.

  13. Remote direct memory access

    Science.gov (United States)

    Archer, Charles J.; Blocksome, Michael A.

    2012-12-11

    Methods, parallel computers, and computer program products are disclosed for remote direct memory access. Embodiments include transmitting, from an origin DMA engine on an origin compute node to a plurality target DMA engines on target compute nodes, a request to send message, the request to send message specifying a data to be transferred from the origin DMA engine to data storage on each target compute node; receiving, by each target DMA engine on each target compute node, the request to send message; preparing, by each target DMA engine, to store data according to the data storage reference and the data length, including assigning a base storage address for the data storage reference; sending, by one or more of the target DMA engines, an acknowledgment message acknowledging that all the target DMA engines are prepared to receive a data transmission from the origin DMA engine; receiving, by the origin DMA engine, the acknowledgement message from the one or more of the target DMA engines; and transferring, by the origin DMA engine, data to data storage on each of the target compute nodes according to the data storage reference using a single direct put operation.

  14. Direct neutrino mass measurements

    Energy Technology Data Exchange (ETDEWEB)

    Weinheimer, Christian, E-mail: weinheimer@uni-muenster.de [Westfaelische Wilhelms-Universitaet, Institut fuer Kernphysik (Germany)

    2013-03-15

    Direct neutrino mass experiments are complementary to searches for neutrinoless double {beta}-decay and to analyses of cosmological data. The previous tritium beta decay experiments at Mainz and at Troitsk have achieved upper limits on the neutrino mass of about 2 eV/c{sup 2} . The KATRIN experiment under construction will improve the neutrino mass sensitivity down to 200 meV/c{sup 2} by increasing strongly the statistics and-at the same time-reducing the systematic uncertainties. Huge improvements have been made to operate the system extremely stably and at very low background rate. The latter comprises new methods to reject secondary electrons from the walls as well as to avoid and to eject electrons stored in traps. As an alternative to tritium {beta}-decay experiments cryo-bolometers investigating the endpoint region of {sup 187}Re {beta}-decay or the electron capture of {sup 163}Ho are being developed. This article briefly reviews the current status of the direct neutrino mass measurements.

  15. Direct saccharification of milo

    Energy Technology Data Exchange (ETDEWEB)

    1981-10-28

    Crude or unrefined milo grain is pulverized to less than 100 mesh, suspended in water, and directly saccharified with enzymes. Thus, 10 kg of pulverized milo (100 mesh) was suspended in 20 liters water, liquified in the presence of bacterial amylase at 90/sup 0/ for 30 minutes and autoclaved for 10 minutes at 120/sup 0/, the liquifaction autoclave procedures were then repeated. The liquified preparation was saccharified in the presence of bacterial glucoamylase at 55/sup 0/ for 72 hours. The percentage saccharification of unrefined milo was 92-97%, which was comparable to that obtained with refined milo or a milo starch preparation. The saccharified milo preparation, when used as a sugar source in glutamic acid, lysine, or inosine fermentation, also showed similar efficiency to that of saccharified milo starch.

  16. Site directed recombination

    Science.gov (United States)

    Jurka, Jerzy W.

    1997-01-01

    Enhanced homologous recombination is obtained by employing a consensus sequence which has been found to be associated with integration of repeat sequences, such as Alu and ID. The consensus sequence or sequence having a single transition mutation determines one site of a double break which allows for high efficiency of integration at the site. By introducing single or double stranded DNA having the consensus sequence flanking region joined to a sequence of interest, one can reproducibly direct integration of the sequence of interest at one or a limited number of sites. In this way, specific sites can be identified and homologous recombination achieved at the site by employing a second flanking sequence associated with a sequence proximal to the 3'-nick.

  17. Nanoparticles and direct immunosuppression

    Science.gov (United States)

    Ngobili, Terrika A

    2016-01-01

    Targeting the immune system with nanomaterials is an intensely active area of research. Specifically, the capability to induce immunosuppression is a promising complement for drug delivery and regenerative medicine therapies. Many novel strategies for immunosuppression rely on nanoparticles as delivery vehicles for small-molecule immunosuppressive compounds. As a consequence, efforts in understanding the mechanisms in which nanoparticles directly interact with the immune system have been overshadowed. The immunological activity of nanoparticles is dependent on the physiochemical properties of the nanoparticles and its subsequent cellular internalization. As the underlying factors for these reactions are elucidated, more nanoparticles may be engineered and evaluated for inducing immunosuppression and complementing immunosuppressive drugs. This review will briefly summarize the state-of-the-art and developments in understanding how nanoparticles induce immunosuppressive responses, compare the inherent properties of nanomaterials which induce these immunological reactions, and comment on the potential for using nanomaterials to modulate and control the immune system. PMID:27229901

  18. Directionally positionable neutron beam

    International Nuclear Information System (INIS)

    Dance, W.E.; Bumgardner, H.M.

    1981-01-01

    Disclosed is apparatus for forming and directionally positioning a neutron beam. The apparatus includes an enclosed housing rotatable about a first axis with a neutron source axially positioned on the axis of rotation of the enclosed housing but not rotating with the housing. The rotatable housing is carried by a vertically positionable arm carried on a mobile transport. A collimator is supported by the rotatable housing and projects into the housing to orientationally position its inlet window at an adjustably fixed axial and radial spacing from the neutron source so that rotation of the enclosed housing causes the inlet window to rotate about a circle which is a fixed axial distance from the neutron source and has the axis of rotation of the housing as its center. (author)

  19. Directional epithermal neutron detector

    International Nuclear Information System (INIS)

    Givens, W.W.; Mills, W.R. Jr.

    1986-01-01

    A borehole tool for epithermal neutron die-away logging of subterranean formations surrounding a borehole is described which consists of: (a) a pulsed source of fast neutrons for irradiating the formations surrounding a borehole, (b) at least one neutron counter for counting epithermal neutrons returning to the borehole from the irradiated formations, (c) a neutron moderating material, (d) an outer thermal neutron shield providing a housing for the counter and the moderating material, (e) an inner thermal neutron shield dividing the housing so as to provide a first compartment bounded by the inner thermal neutron shield and a first portion of the outer thermal neutron shield and a second compartment bounded by the inner thermal neutron shield and a second portion of the outer thermal neutron shield, the counter being positioned within the first compartment and the moderating material being positioned within the second compartment, and (f) means for positioning the borehole tool against one side of the borehole wall and azimuthally orienting the borehole tool such that the first chamber is in juxtaposition with the borehole wall, the formation epithermal neutrons penetrating into the first chamber through the first portion of the outer thermal neutron shield are detected by the neutron counter for die-away measurement, thereby maximizing the directional sensitivty of the neutron counter to formation epithermal neutrons, the borehole fluid epithermal neutrons penetrating into the second chamber through the second chamber through the second portion of the outer thermal neutron shield are largely slowed down and lowered in energy by the moderating material and absorbed by the inner thermal neutron shield before penetrating into the first chamber, thereby minimizing the directional sensitivity of the neutron counter to borehole fluid epithermal neutrons

  20. Coatings for directional eutectics

    Science.gov (United States)

    Rairden, J. R.; Jackson, M. R.

    1976-01-01

    Coatings developed to provide oxidation protection for the directionally-solidified eutectic alloy NiTaC-B (4.4 weight percent Cr) were evaluated. Of seven Co-, Fe- and Ni-base coatings that were initially investigated, best resistance to cyclic oxidation was demonstrated by duplex coatings fabricated by depositing a layer of NiCrAl(Y) by vacuum evaporation from an electron beam source followed by deposition of an Al overlayer using the pack cementation process. It was found that addition of carbon to the coating alloy substantially eliminated the problem of fiber denudation in TaC-type eutectic alloys. Burner rig cycled NiTaC-B samples coated with Ni-20Cr-5Al-0.1C-0.1Y+Al and rupture-tested at 1100 deg C performed as well as or better than uncoated, vacuum cycled and air-tested NiTaC-13; however, a slight degradation with respect to uncoated material was noted in air-stress rupture tests at 870 deg C for both cycled and uncycled samples.

  1. New directions in Guatemala.

    Science.gov (United States)

    1997-02-01

    This news brief relates some new directions, since its inception in 1988, which the Family Welfare Association of Guatemala (APROFAM) will be undertaking during 1996-97. In December 1997, APROFAM restructured its program to include reproductive health services with family planning services. The program will target rural Mayan communities. The program will be working toward service sustainability, due to reduced external support. In October 1996 a new board was established that will focus on marketing, IEC, finance and administration, rural development, and clinical services. Meetings between the new board of directors of APROFAM and JOICFP focused on the use of integrated programs as a model for widespread programming among the rural Mayan population. The integrated program that was implemented by JOICFP was successful in reaching Mayan communities of Solola. This population was difficult to reach with conventional family planning approaches. The integrated program was successful in establishing trust with and participation of the rural Mayans. Activities such as parasite control, skills training, and income generation for women were useful in establishing trust and promoting self-reliance. Integrated programs will refocus on family planning and developing self-reliance. The UNFPA will be conducting an annual internal evaluation as a means of sharing information and deepening understanding of project implementation.

  2. Direct UV-written broadband directional broadband planar waveguide couplers

    DEFF Research Database (Denmark)

    Olivero, Massimo; Svalgaard, Mikael

    2005-01-01

    We report the fabrication of broadband directional couplers by direct UV-writing. The fabrication process is shown to be beneficial, robust and flexible. The components are compact and show superior performance in terms of loss and broadband operation.......We report the fabrication of broadband directional couplers by direct UV-writing. The fabrication process is shown to be beneficial, robust and flexible. The components are compact and show superior performance in terms of loss and broadband operation....

  3. Host-Pathogen Interactions in Guillain-Barré Syndrome : the role of Campylobacter jejuni lipooligosaccharide sialylation

    NARCIS (Netherlands)

    A.P. Heikema (Astrid)

    2013-01-01

    markdownabstract*Campylobacter jejuni* (*C. jejuni*) is a spiral, comma-shaped Gram-negative bacterium which is motile due to bipolar flagella. *C. jejuni* is frequently present in the intestines of poultry and birds, where it is considered to be part of the normal intestinal flora (1).

  4. Estimation of directional wave spreading

    Digital Repository Service at National Institute of Oceanography (India)

    Mandal, S.; Bhat, S.S.; Anand, N.M.; Nayak, B.U.

    Directional properties of ocean waves are of great economic interest. The knowledge of wave directionality is important for the design of maritime structures and offshore operations. Two main aspects are considered for this study for the data...

  5. Estimation of wave directional spreading

    Digital Repository Service at National Institute of Oceanography (India)

    Deo, M.C.; Gondane, D.S.; SanilKumar, V.

    One of the useful measures of waves directional spreading at a given location is the directional spreading parameter. This paper presents a new approach to arrive at its characteristic value using the computational technique of Artificial Neural...

  6. Geothermal Technologies Program: Direct Use

    Energy Technology Data Exchange (ETDEWEB)

    2004-08-01

    This general publication describes geothermal direct use systems, and how they have been effectively used throughout the country. It also describes the DOE program R&D efforts in this area, and summarizes several projects using direct use technology.

  7. Innovative tool of direct marketing

    OpenAIRE

    T.S. Maksymova

    2010-01-01

    The aspects of direct marketing activation on the basis of interactive applications introduction are examined. Basic advantages, linked with the use of the integrated marketing communications during formation of direct marketing strategies are open up.

  8. Direct channel problems and phenomena

    International Nuclear Information System (INIS)

    Cutkosky, R.E.

    1975-01-01

    Direct channel problems and phenomena are considered covering the need for precision hadron spectroscopy, the data base for precision hadron spectroscopy, some relations between direct-channel and cross-channel effects, and spin rotation phenomena

  9. Directional wave measurements and modelling

    Digital Repository Service at National Institute of Oceanography (India)

    Anand, N.M.; Nayak, B.U.; Bhat, S.S.; SanilKumar, V.

    Some of the results obtained from analysis of the monsoon directional wave data measured over 4 years in shallow waters off the west coast of India are presented. The directional spectrum computed from the time series data seems to indicate...

  10. Psychiatric Advance Directives: Getting Started

    Science.gov (United States)

    ... News Legal Issues Search for: About PADs A psychiatric advance directive (PAD) is a legal document that ... decisions during a mental health crisis. Getting Started Psychiatric advance directives (PADs) are relatively new legal instruments ...

  11. Seveso directive: the leading innovations

    International Nuclear Information System (INIS)

    Cozzani, V.; Zanelli, S.

    1998-01-01

    Directive 96/82/EC on the control of major accident hazards caused by dangerous substances, also known as 'Seveso-II' Directive, was adopted by the European Council on December 1996. The member states of the European Community shall bring into force the Directive not later than February 1999. Some innovative aspects of the Directive are discussed. In particular, this paper focuses on the effects of the new criteria for the identification of establishments to which the Directive obligations will apply and for land use planning in the vicinity of the establishments [it

  12. Dynamic behaviors in directed networks

    International Nuclear Information System (INIS)

    Park, Sung Min; Kim, Beom Jun

    2006-01-01

    Motivated by the abundance of directed synaptic couplings in a real biological neuronal network, we investigate the synchronization behavior of the Hodgkin-Huxley model in a directed network. We start from the standard model of the Watts-Strogatz undirected network and then change undirected edges to directed arcs with a given probability, still preserving the connectivity of the network. A generalized clustering coefficient for directed networks is defined and used to investigate the interplay between the synchronization behavior and underlying structural properties of directed networks. We observe that the directedness of complex networks plays an important role in emerging dynamical behaviors, which is also confirmed by a numerical study of the sociological game theoretic voter model on directed networks

  13. Direct photons in WA98

    CERN Document Server

    Aggarwal, M M; Ahammed, Z; Angelis, Aris L S; Antonenko, V G; Arefev, V; Astakhov, V A; Avdeichikov, V; Awes, T C; Baba, P V K S; Badyal, S K; Barlag, C; Bathe, S; Batyunya, B; Bernier, T; Bhalla, K B; Bhatia, V S; Blume, C; Bock, R; Bohne, E M; Böröcz, Z K; Bucher, D; Buijs, A; Büsching, H; Carlén, L; Chalyshev, V; Chattopadhyay, S; Cherbachev, R; Chujo, T; Claussen, A; Das, A C; Decowski, M P; Delagrange, H; Dzhordzhadze, V; Dönni, P; Dubovik, I; Dutt, S; Dutta-Majumdar, M R; El-Chenawi, K F; Eliseev, S; Enosawa, K; Foka, P Y; Fokin, S L; Ganti, M S; Garpman, S; Gavrishchuk, O P; Geurts, F J M; Ghosh, T K; Glasow, R; Gupta, S K; Guskov, B; Gustafsson, Hans Åke; Gutbrod, H H; Higuchi, R; Hrivnacova, I; Ippolitov, M S; Kalechofsky, H; Kamermans, R; Kampert, K H; Karadzhev, K; Karpio, K; Kato, S; Kees, S; Klein-Bösing, C; Knoche, S; Kolb, B W; Kosarev, I G; Kucheryaev, I; Krümpel, T; Kugler, A; Kulinich, P A; Kurata, M; Kurita, K; Kuzmin, N A; Langbein, I; Lee, Y Y; Löhner, H; Luquin, Lionel; Mahapatra, D P; Man'ko, V I; Martin, M; Martínez, G; Maksimov, A; Mgebrishvili, G; Miake, Y; Mir, M F; Mishra, G C; Miyamoto, Y; Mohanty, B; Morrison, D; Mukhopadhyay, D S; Naef, H; Nandi, B K; Nayak, S K; Nayak, T K; Neumaier, S; Nyanin, A; Nikitin, V A; Nikolaev, S; Nilsson, P O; Nishimura, S; Nomokonov, V P; Nystrand, J; Obenshain, F E; Oskarsson, A; Otterlund, I; Pachr, M; Pavlyuk, S; Peitzmann, Thomas; Petracek, V; Pinganaud, W; Plasil, F; Von Poblotzki, U; Purschke, M L; Rak, J; Raniwala, R; Raniwala, S; Ramamurthy, V S; Rao, N K; Retière, F; Reygers, K; Roland, G; Rosselet, L; Rufanov, I A; Roy, C; Rubio, J M; Sako, H; Sambyal, S S; Santo, R; Sato, S; Schlagheck, H; Schmidt, H R; Schutz, Y; Shabratova, G; Shah, T H; Sibiryak, Yu; Siemiarczuk, T; Silvermyr, D; Sinha, B C; Slavin, N V; Söderström, K; Solomey, Nickolas; Sood, G; Sørensen, S P; Stankus, P; Stefanek, G; Steinberg, P; Stenlund, E; Stüken, D; Sumbera, M; Svensson, S; Trivedi, M D; Tsvetkov, A A; Tykarski, L; Urbahn, J; Van den Pijll, E C; van Eijndhoven, N; van Nieuwenhuizen, G J; Vinogradov, A; Viyogi, Y P; Vodopyanov, A S; Vörös, S; Wyslouch, B; Yagi, K; Yokota, Y; Young, G R

    2002-01-01

    A measurement of direct photon production in /sup 208/Pb+/sup 208/Pb collisions at 158 A GeV has been carried out in the CERN WA98 experiment. The invariant yield of direct photons was extracted as a function of transverse momentum in the interval 0.51.5 GeV/c. the result constitutes the first observation of direct photons in ultrarelativistic heavy-ion collisions. (19 refs).

  14. Direct cooled power electronics substrate

    Science.gov (United States)

    Wiles, Randy H [Powell, TN; Wereszczak, Andrew A [Oak Ridge, TN; Ayers, Curtis W [Kingston, TN; Lowe, Kirk T [Knoxville, TN

    2010-09-14

    The disclosure describes directly cooling a three-dimensional, direct metallization (DM) layer in a power electronics device. To enable sufficient cooling, coolant flow channels are formed within the ceramic substrate. The direct metallization layer (typically copper) may be bonded to the ceramic substrate, and semiconductor chips (such as IGBT and diodes) may be soldered or sintered onto the direct metallization layer to form a power electronics module. Multiple modules may be attached to cooling headers that provide in-flow and out-flow of coolant through the channels in the ceramic substrate. The modules and cooling header assembly are preferably sized to fit inside the core of a toroidal shaped capacitor.

  15. Epidemic threshold in directed networks

    Science.gov (United States)

    Li, Cong; Wang, Huijuan; Van Mieghem, Piet

    2013-12-01

    Epidemics have so far been mostly studied in undirected networks. However, many real-world networks, such as the online social network Twitter and the world wide web, on which information, emotion, or malware spreads, are directed networks, composed of both unidirectional links and bidirectional links. We define the directionality ξ as the percentage of unidirectional links. The epidemic threshold τc for the susceptible-infected-susceptible (SIS) epidemic is lower bounded by 1/λ1 in directed networks, where λ1, also called the spectral radius, is the largest eigenvalue of the adjacency matrix. In this work, we propose two algorithms to generate directed networks with a given directionality ξ. The effect of ξ on the spectral radius λ1, principal eigenvector x1, spectral gap (λ1-λ2), and algebraic connectivity μN-1 is studied. Important findings are that the spectral radius λ1 decreases with the directionality ξ, whereas the spectral gap and the algebraic connectivity increase with the directionality ξ. The extent of the decrease of the spectral radius depends on both the degree distribution and the degree-degree correlation ρD. Hence, in directed networks, the epidemic threshold is larger and a random walk converges to its steady state faster than that in undirected networks with the same degree distribution.

  16. Seeking coherence among environmental directives

    NARCIS (Netherlands)

    Beijen, Barbara

    2014-01-01

    European environmental law consists of a large number of directives and regulations dealing with environmental domains such as air, water, or waste, or with issues such as greenhouse gases, chemicals or industrial emissions. These directives and regulations do not form a comprehensive system of

  17. Direct activation of microcrystalline zeolites

    NARCIS (Netherlands)

    Ortiz-Iniesta, Maria Jesus; Heeres, Hero Jan; Melian-Cabrera, Ignacio

    2013-01-01

    In this work a direct activation route of zeolites is assessed. It consists of NH4-exchanging the as-synthesized solids before removing the organic template. Calcination afterwards serves to combust the organic template and creates the Bronsted sites directly; thus applying merely a single thermal

  18. Type-Directed Partial Evaluation

    DEFF Research Database (Denmark)

    Danvy, Olivier

    1998-01-01

    Type-directed partial evaluation uses a normalization function to achieve partial evaluation. These lecture notes review its background, foundations, practice, and applications. Of specific interest is the modular technique of offline and online type-directed partial evaluation in Standard ML...

  19. Exchange effects in direct reactions

    International Nuclear Information System (INIS)

    LeMere, M.; Kanellopoulos, E.J.; Suenkel, W.; Tang, Y.C.

    1979-01-01

    The effect of antisymmetrization in direct reactions is examined by studying the properties of the coupling-normalization kernel function occurring in a resonating-group formulation. From this study, one obtains useful information concerning the general behavior of direct-reactiion processes and some justification for the use of three-body models in phenomenological analyses

  20. Type-Directed Partial Evaluation

    DEFF Research Database (Denmark)

    Danvy, Olivier

    1998-01-01

    Type-directed partial evaluation uses a normalization function to achieve partial evaluation. These lecture notes review its background, foundations, practice, and applications. Of specific interest is the modular technique of offline and online type-directed partial evaluation in Standard ML of ...

  1. Eldercare at Home: Advanced Directives

    Science.gov (United States)

    ... permanently? Helping the person fill out a living will (advance directive) A living will states a person's wishes about medical care if ... never be in a situation where another person will have to make decisions ... it is to have an advance directive. However, don't assume that your loved ...

  2. New directions in information organization

    CERN Document Server

    Park, Jung-ran; Spink, Amanda

    2013-01-01

    New Directions in Information Organization, co-edited by Dr. Jung-ran Park and Dr. Lynne Howarth seeks to provide an overview and understanding of the future directions, leading edge theories and models for research and practice in information organization.

  3. Target selection for direct marketing.

    NARCIS (Netherlands)

    Bult, Jan Roelf

    1993-01-01

    In this thesis we concentrated on the use ol direct mail for targeting potential buyers. The major characteristics that influences the success of a plomotional direct mail campaign are the of-fbr,the communication elements, the timing or sequence of these communication elements, and the list of

  4. Direct oral anticoagulants: An update.

    Science.gov (United States)

    Franco Moreno, Ana Isabel; Martín Díaz, Rosa María; García Navarro, María José

    2017-12-30

    Vitamin K antagonists were the only choice for chronic oral anticoagulation for more than half a century. Over the past few years, direct oral anticoagulants have emerged, including one direct thrombin inhibitor (dabigatran etexilate) and three factor Xa inhibitors (apixaban, edoxaban and rivaroxaban). In randomised controlled trials comparing direct oral anticoagulants with traditional vitamin K antagonists, the direct oral anticoagulants all showed a favourable benefit-risk balance in their safety and efficacy profile, in prevention of thromboembolic events in patients with atrial fibrillation and in the prevention and treatment of venous thromboembolism and acute coronary syndrome. In 2008, dabigatran was the first direct oral anticoagulant approved by the European Medicine Agency. Subsequently, rivaroxaban, apixaban and edoxaban were also authorised. This article reviews the evidence related to the use of these drugs. Copyright © 2017 Elsevier España, S.L.U. All rights reserved.

  5. Efficient Placement of Directional Antennas

    Energy Technology Data Exchange (ETDEWEB)

    Pan, Feng [Los Alamos National Laboratory; Kasiviswanathan, Shiva [Los Alamos National Laboratory

    2010-09-20

    Directional antenna is an technology for the proliferation of wireless networks. In centralized wireless network, wireless devices communicate through base stations. Directed antennas are placed on base stations and form a backbone of communication. The communication between base stations and wireless devices can be interfered due to a large number of wireless device. Methodically positioning and orienting directed antennas can help to reduce the interference while saving energy. An integer linear programming is developed for siting and directing antennas on multiple base stations, and this formulation can be extended to model non-overlapping channels. Through the integer programming formulation, optimal antenna positions can be used to analyze the performance of directed antennas with different parameters like the number base stations and the number of non-overlapping channels.

  6. Direct catastrophic injury in sports.

    Science.gov (United States)

    Boden, Barry P

    2005-11-01

    Catastrophic sports injuries are rare but tragic events. Direct (traumatic) catastrophic injury results from participating in the skills of a sport, such as a collision in football. Football is associated with the greatest number of direct catastrophic injuries for all major team sports in the United States. Pole vaulting, gymnastics, ice hockey, and football have the highest incidence of direct catastrophic injuries for sports in which males participate. In most sports, the rate of catastrophic injury is higher at the collegiate than at the high school level. Cheerleading is associated with the highest number of direct catastrophic injuries for all sports in which females participate. Indirect (nontraumatic) injury is caused by systemic failure as a result of exertion while participating in a sport. Cardiovascular conditions, heat illness, exertional hyponatremia, and dehydration can cause indirect catastrophic injury. Understanding the common mechanisms of injury and prevention strategies for direct catastrophic injuries is critical in caring for athletes.

  7. Potential theory for directed networks.

    Directory of Open Access Journals (Sweden)

    Qian-Ming Zhang

    Full Text Available Uncovering factors underlying the network formation is a long-standing challenge for data mining and network analysis. In particular, the microscopic organizing principles of directed networks are less understood than those of undirected networks. This article proposes a hypothesis named potential theory, which assumes that every directed link corresponds to a decrease of a unit potential and subgraphs with definable potential values for all nodes are preferred. Combining the potential theory with the clustering and homophily mechanisms, it is deduced that the Bi-fan structure consisting of 4 nodes and 4 directed links is the most favored local structure in directed networks. Our hypothesis receives strongly positive supports from extensive experiments on 15 directed networks drawn from disparate fields, as indicated by the most accurate and robust performance of Bi-fan predictor within the link prediction framework. In summary, our main contribution is twofold: (i We propose a new mechanism for the local organization of directed networks; (ii We design the corresponding link prediction algorithm, which can not only testify our hypothesis, but also find out direct applications in missing link prediction and friendship recommendation.

  8. Direct Manipulation in Virtual Reality

    Science.gov (United States)

    Bryson, Steve

    2003-01-01

    Virtual Reality interfaces offer several advantages for scientific visualization such as the ability to perceive three-dimensional data structures in a natural way. The focus of this chapter is direct manipulation, the ability for a user in virtual reality to control objects in the virtual environment in a direct and natural way, much as objects are manipulated in the real world. Direct manipulation provides many advantages for the exploration of complex, multi-dimensional data sets, by allowing the investigator the ability to intuitively explore the data environment. Because direct manipulation is essentially a control interface, it is better suited for the exploration and analysis of a data set than for the publishing or communication of features found in that data set. Thus direct manipulation is most relevant to the analysis of complex data that fills a volume of three-dimensional space, such as a fluid flow data set. Direct manipulation allows the intuitive exploration of that data, which facilitates the discovery of data features that would be difficult to find using more conventional visualization methods. Using a direct manipulation interface in virtual reality, an investigator can, for example, move a data probe about in space, watching the results and getting a sense of how the data varies within its spatial volume.

  9. Potential Theory for Directed Networks

    Science.gov (United States)

    Zhang, Qian-Ming; Lü, Linyuan; Wang, Wen-Qiang; Zhou, Tao

    2013-01-01

    Uncovering factors underlying the network formation is a long-standing challenge for data mining and network analysis. In particular, the microscopic organizing principles of directed networks are less understood than those of undirected networks. This article proposes a hypothesis named potential theory, which assumes that every directed link corresponds to a decrease of a unit potential and subgraphs with definable potential values for all nodes are preferred. Combining the potential theory with the clustering and homophily mechanisms, it is deduced that the Bi-fan structure consisting of 4 nodes and 4 directed links is the most favored local structure in directed networks. Our hypothesis receives strongly positive supports from extensive experiments on 15 directed networks drawn from disparate fields, as indicated by the most accurate and robust performance of Bi-fan predictor within the link prediction framework. In summary, our main contribution is twofold: (i) We propose a new mechanism for the local organization of directed networks; (ii) We design the corresponding link prediction algorithm, which can not only testify our hypothesis, but also find out direct applications in missing link prediction and friendship recommendation. PMID:23408979

  10. Proximinality in generalized direct sums

    Directory of Open Access Journals (Sweden)

    Darapaneni Narayana

    2004-01-01

    Full Text Available We consider proximinality and transitivity of proximinality for subspaces of finite codimension in generalized direct sums of Banach spaces. We give several examples of Banach spaces where proximinality is transitive among subspaces of finite codimension.

  11. EOP Current Magnitude and Direction

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — These data contain shipboard current magnitudes and directions collected in the Pacific, both pelagic and near shore environments. Data is collected using an RD...

  12. Law, autonomy and advance directives.

    Science.gov (United States)

    Willmott, Lindy; White, Ben; Mathews, Ben

    2010-12-01

    The principle of autonomy underpins legal regulation of advance directives that refuse life-sustaining medical treatment. The primacy of autonomy in this domain is recognised expressly in the case law, through judicial pronouncement, and implicitly in most Australian jurisdictions, through enactment into statute of the right to make an advance directive. This article seeks to justify autonomy as an appropriate principle for regulating advance directives and relies on three arguments: the necessity of autonomy in a liberal democracy; the primacy of autonomy in medical ethics discourse; and the uncontested importance of autonomy in the law on contemporaneous refusal of medical treatment. This article also responds to key criticisms that autonomy is not an appropriate organising principle to underpin legal regulation of advance directives.

  13. Directed Energy for Interstellar Study

    Data.gov (United States)

    National Aeronautics and Space Administration — We propose to expand our investigations started in our NIAC Phase I of using directed energy to allow the achievement of relativistic flight to pave the way to the...

  14. Foreign direct investment in China

    OpenAIRE

    Bredero, Q.S.

    2007-01-01

    Foreign Direct Investment in China is one of the most comprehensive studies of FDI in China and provides a remarkable background of information on the evolution of China’s FDI policies over the last 30 years.

  15. Direction-dependent exponential biassing

    International Nuclear Information System (INIS)

    Bending, R.C.

    1974-01-01

    When Monte Carlo methods are applied to penetration problems, the use of variance reduction techniques is essential if realistic computing times are to be achieved. A technique known as direction-dependent exponential biassing is described which is simple to apply and therefore suitable for problems with difficult geometry. The material cross section in any region is multiplied by a factor which depends on the particle direction, so that particles travelling in a preferred direction ''see'' a smaller cross section than those travelling in the opposite direction. A theoretical study shows that substantial gains may be obtained, and that the choice of biassing parameter is not critical. The method has been implemented alongside other importance sampling techniques in the general Monte Carlo code SPARTAN, and results obtained for simple problems using this code are included. 4 references. (U.S.)

  16. New directions in tokamak reactors

    International Nuclear Information System (INIS)

    Baker, C.C.

    1985-01-01

    New directions for tokamak research are briefly mentioned. Some of the areas for new considerations are the following: reactor size, beta ratio, current drivers, blankets, impurity control, and modular designs

  17. Directional spectrum of ocean waves

    Digital Repository Service at National Institute of Oceanography (India)

    Fernandes, A.A; Gouveia, A; Nagarajan, R.

    This paper describes a methodology for obtaining the directional spectrum of ocean waves from time series measurement of wave elevation at several gauges arranged in linear or polygonal arrays. Results of simulated studies using sinusoidal wave...

  18. Directed Innovation of Business Models

    Directory of Open Access Journals (Sweden)

    Stelian Brad

    2016-06-01

    Full Text Available Business model innovation is an important issue to keep business competitive and increase company’s profits. Due to many market attractors, identification of appropriate paths of business model evolution is a painful and risky process. To improve decision’s effectiveness in this process, an architectural construct of analysis and conceptualization for business model innovation that combines directed evolution and blue ocean concepts is proposed in this paper under the name of directed innovation. It displays the key points where innovations would happen to direct adaptation of the business model towards sustainable competitiveness. Formulation of mature solutions is supported by inventive problem solving tools. The significance of the directed innovation approach is demonstrated in a case study dealing with business model innovation of a software company.

  19. Multi-Directional Experimental Facility

    Data.gov (United States)

    Federal Laboratory Consortium — The ATLSS Multi-directional Experimental Laboratory was constructed in 1987 under funding from the National Science Foundation to be a major facility for large-scale...

  20. Spontaneous direct and reverse osmosis

    International Nuclear Information System (INIS)

    Valitov, N.Kh.

    1996-01-01

    It has been ascertained experimentally that in the course of separation of CsCl, KCl, NaCl aqueous solutions by semi-permeable membrane from distilled water the direct and then reverse osmosis are observed. The same sequence is observed in case of separation of CsCl aqueous solutions from NaCl of different concentrations. The reason for the direct and reverse osmosis has been explained. 5 refs.; 3 figs. 1 tab

  1. Spillovers from Foreign Direct Investment

    DEFF Research Database (Denmark)

    Meyer, Klaus E.; Sinani, Evis

    2005-01-01

    The extensive empirical literature analyzing productivity spillovers from foreign direct investment to local firms provides inconclusive results. Some studies find that foreign presence has a positive impact on the productivity of domestic firms, while others find no evidence or a negative effect...... for industrialized countries in the 1990s. Transition economies may experience spillovers, but these have been declining in recent years. Keywords: developing countries, transition economies, spillovers, foreign direct investment, technology transfer, meta-analysis...

  2. Quantum direct communication with authentication

    International Nuclear Information System (INIS)

    Lee, Hwayean; Lim, Jongin; Yang, HyungJin

    2006-01-01

    We propose two quantum direct communication (QDC) protocols with user authentication. Users can identify each other by checking the correlation of Greenberger-Horne-Zeilinger (GHZ) states. Alice can directly send a secret message to Bob without any previously shared secret using the remaining GHZ states after authentication. Our second QDC protocol can be used even though there is no quantum link between Alice and Bob. The security of the transmitted message is guaranteed by properties of entanglement of GHZ states

  3. Direct Bandgap Group IV Materials

    Science.gov (United States)

    2016-01-21

    AFRL-AFOSR-JP-TR-2017-0049 Direct Bandgap group IV Materials Hung Hsiang Cheng NATIONAL TAIWAN UNIVERSITY Final Report 01/21/2016 DISTRIBUTION A...NAME(S) AND ADDRESS(ES) NATIONAL TAIWAN UNIVERSITY 1 ROOSEVELT RD. SEC. 4 TAIPEI CITY, 10617 TW 8. PERFORMING ORGANIZATION REPORT NUMBER 9. SPONSORING...14. ABSTRACT Direct bandgap group IV materials have been long sought for in both academia and industry for the implementation of photonic devices

  4. Geothermal Direct Heat Application Potential

    Energy Technology Data Exchange (ETDEWEB)

    Lienau, Paul J

    1989-01-01

    The geothermal direct-use industry growth trends, potential, needs, and how they can be met, are addressed. Recent investigations about the current status of the industry and the identification of institutional and technical needs provide the basis on which this paper is presented. Initial drilling risk is the major obstacle to direct-use development. The applications presented include space and district heating projects, heat pumps (heating and cooling), industrial processes, resorts and pools, aquaculture and agriculture.

  5. 75 FR 76630 - Direct Investment Surveys: BE-577, Quarterly Survey of U.S. Direct Investment Abroad-Direct...

    Science.gov (United States)

    2010-12-09

    ....S. Direct Investment Abroad--Direct Transactions of U.S. Reporter With Foreign Affiliate.'' The..., Quarterly Survey of U.S. Direct Investment Abroad--Direct Transactions of U.S. Reporter With Foreign...] RIN 0691--AA75 Direct Investment Surveys: BE-577, Quarterly Survey of U.S. Direct Investment Abroad...

  6. Direct conversion of fusion energy

    International Nuclear Information System (INIS)

    Johansson, Markus

    2003-03-01

    Deuterium and tritium are expected to be used as fuel in the first fusion reactors. Energy is released as kinetic energy of ions and neutrons, when deuterium reacts with tritium. One way to convert the kinetic energy to electrical energy, is to let the ions and neutrons hit the reactor wall and convert the heat that is caused by the particle bombardment to electrical energy with ordinary thermal conversion. If the kinetic energy of the ions instead is converted directly to electrical energy, a higher efficiency of the energy conversion is possible. The majority of the fusion energy is released as kinetic energy of neutrons, when deuterium reacts with tritium. Fusion reactions such as the D-D reactions, the D- 3 He reaction and the p- 11 B reaction, where a larger part of the fusion energy becomes kinetic energy of charged particles, appears therefore more suitable for direct conversion. Since they have lower reactivity than the D-T reaction, they need a larger βB 2 0 to give sufficiently high fusion power density. Because of this, the fusion configurations spherical torus (ST) and field-reversed configuration (FRC), where high β values are possible, appear interesting. Rosenbluth and Hinton come to the conclusion that efficient direct conversion isn't possible in closed field line systems and that open geometries, which facilitate direct conversion, provide inadequate confinement for D- 3 He. It is confirmed in this study that it doesn't seem possible to achieve as high direct conversion efficiency in closed systems as in open systems. ST and FRC fusion power plants that utilize direct conversion seem however interesting. Calculations with the help of Maple indicate that the reactor parameters needed for a D-D ST and a D 3 He ST hopefully are possible to achieve. The best energy conversion option for a D-D or D 3 He ST appears to be direct electrodynamic conversion (DEC) together with ordinary thermal conversion or liquid metal MHD conversion (LMMHD). For a D

  7. Direct conversion of fusion energy

    Energy Technology Data Exchange (ETDEWEB)

    Johansson, Markus

    2003-03-01

    Deuterium and tritium are expected to be used as fuel in the first fusion reactors. Energy is released as kinetic energy of ions and neutrons, when deuterium reacts with tritium. One way to convert the kinetic energy to electrical energy, is to let the ions and neutrons hit the reactor wall and convert the heat that is caused by the particle bombardment to electrical energy with ordinary thermal conversion. If the kinetic energy of the ions instead is converted directly to electrical energy, a higher efficiency of the energy conversion is possible. The majority of the fusion energy is released as kinetic energy of neutrons, when deuterium reacts with tritium. Fusion reactions such as the D-D reactions, the D-{sup 3}He reaction and the p-{sup 11}B reaction, where a larger part of the fusion energy becomes kinetic energy of charged particles, appears therefore more suitable for direct conversion. Since they have lower reactivity than the D-T reaction, they need a larger {beta}B{sup 2}{sub 0} to give sufficiently high fusion power density. Because of this, the fusion configurations spherical torus (ST) and field-reversed configuration (FRC), where high {beta} values are possible, appear interesting. Rosenbluth and Hinton come to the conclusion that efficient direct conversion isn't possible in closed field line systems and that open geometries, which facilitate direct conversion, provide inadequate confinement for D-{sup 3}He. It is confirmed in this study that it doesn't seem possible to achieve as high direct conversion efficiency in closed systems as in open systems. ST and FRC fusion power plants that utilize direct conversion seem however interesting. Calculations with the help of Maple indicate that the reactor parameters needed for a D-D ST and a D{sub 3} He ST hopefully are possible to achieve. The best energy conversion option for a D-D or D{sub 3} He ST appears to be direct electrodynamic conversion (DEC) together with ordinary thermal conversion

  8. Comparative Evaluation of Ampicillin and Trimethoprim Sulfamoxole Combination in Gonorrhoea

    Directory of Open Access Journals (Sweden)

    J Chendrayudu

    1981-01-01

    Full Text Available Fifty men suffering from uncomplicated urethritis were treated either with 1, 280 mg of (TMP and 6,400 mg of (SDMO (Supristol 16 tablets eually divided doses taken at a 12 or with a single dose of 3.5 gm of with 1 gm of probenecid . The cure rate in TMP-SDMO regimen was 79% while that in AMP-PBD regimen was 95.7%. Sensitivity of the organism to penicillin, ampicillin and TMP-SDMO. Toxic effects of the drugs were studied.

  9. Functional characterization of antibodies against Neisseria gonorrhoeae opacity protein loops.

    Directory of Open Access Journals (Sweden)

    Jessica G Cole

    2009-12-01

    Full Text Available The development of a gonorrhea vaccine is challenged by the lack of correlates of protection. The antigenically variable neisserial opacity (Opa proteins are expressed during infection and have a semivariable (SV and highly conserved (4L loop that could be targeted in a vaccine. Here we compared antibodies to linear (Ab(linear and cyclic (Ab(cyclic peptides that correspond to the SV and 4L loops and selected hypervariable (HV(2 loops for surface-binding and protective activity in vitro and in vivo.Ab(SV cyclic bound a greater number of different Opa variants than Ab(SV linear, including variants that differed by seven amino acids. Antibodies to the 4L peptide did not bind Opa-expressing bacteria. Ab(SV (cyclic and Ab(HV2 (cyclic, but not Ab(SV (linear or Ab(HV2 linear agglutinated homologous Opa variants, and Ab(HV2BD (cyclic but not Ab(HV2BD (linear blocked the association of OpaB variants with human endocervical cells. Only Ab(HV2BD (linear were bactericidal against the serum resistant parent strain. Consistent with host restrictions in the complement cascade, the bactericidal activity of Ab(HV2BD (linear was increased 8-fold when rabbit complement was used. None of the antibodies was protective when administered vaginally to mice. Antibody duration in the vagina was short-lived, however, with <50% of the antibodies recovered 3 hrs post-administration.We conclude that an SV loop-specific cyclic peptide can be used to induce antibodies that recognize a broad spectrum of antigenically distinct Opa variants and have agglutination abilities. HV(2 loop-specific cyclic peptides elicited antibodies with agglutination and adherence blocking abilities. The use of human complement when testing the bactericidal activity of vaccine-induced antibodies against serum resistant gonococci is also important.

  10. Directive and Non-Directive Movement in Child Therapy.

    Science.gov (United States)

    Krason, Katarzyna; Szafraniec, Grazyna

    1999-01-01

    Presents a new authorship method of child therapy based on visualization through motion. Maintains that this method stimulates motor development and musical receptiveness, and promotes personality development. Suggests that improvised movement to music facilitates the projection mechanism and that directed movement starts the channeling phase.…

  11. Multi-Directional Environmental Sensors

    Science.gov (United States)

    Manohara, Harish (Inventor); Del Castillo, Linda Y. (Inventor); Mojarradi, Mohammed M. (Inventor)

    2016-01-01

    Systems and methods in accordance with embodiments of the invention implement multi-directional environmental sensors. In one embodiment, a multi-directional environmental sensor includes: an inner conductive element that is substantially symmetrical about three orthogonal planes; an outer conductive element that is substantially symmetrical about three orthogonal planes; and a device that measures the electrical characteristics of the multi-directional environmental sensor, the device having a first terminal and a second terminal; where the inner conductive element is substantially enclosed within the outer conductive element; where the inner conductive element is electrically coupled to the first terminal of the device; and where the outer conductive element is electrically coupled to the second terminal of the device.

  12. Direct Methanol Fuel Cell, DMFC

    Directory of Open Access Journals (Sweden)

    Amornpitoksuk, P.

    2003-09-01

    Full Text Available Direct Methanol Fuel Cell, DMFC is a kind of fuel cell using methanol as a fuel for electric producing. Methanol is low cost chemical substance and it is less harmful than that of hydrogen fuel. From these reasons it can be commercial product. The electrocatalytic reaction of methanol fuel uses Pt-Ru metals as the most efficient catalyst. In addition, the property of membrane and system designation are also effect to the fuel cell efficient. Because of low power of methanol fuel cell therefore, direct methanol fuel cell is proper to use for the energy source of small electrical devices and vehicles etc.

  13. Directional Validation of Wave Predictions

    Science.gov (United States)

    2007-03-01

    motivators: I) the desire to make the problem more solution is simply to use only variables directly Cx- manageable via frequency-wise integration of direc...ViaW()2 + bi(f), where . = j F(f) d. The calculation in reverse is a, = in, cosO , and b, = ni, sinf0 . Note that if we choose f, andf2 as values close...34). The use of a broader band of frequencies makes the metric more stable, but CALCULATION OF MEAN WAVE DIRECTION AND increases the risk that two

  14. Directions for improved fusion reactors

    International Nuclear Information System (INIS)

    Krakowski, R.A.; Miller, R.L.; Delene, J.G.

    1986-01-01

    Conceptual fusion reactor studies over the past 10 to 15 years have projected systems that may be too large, complex, and costly to be of commercial interest. One main direction for improved fusion reactors points towards smaller, higher-power-density approaches. First-order economic issues (i.e., unit direct cost and cost of electricity) are used to support the need for more compact fusion reactors. A generic fusion physics/engineering/costing model is used to provide a quantiative basis for these arguments for specific fusion concepts

  15. PROTOTIPE VIDEO EDITOR DENGAN MENGGUNAKAN DIRECT X DAN DIRECT SHOW

    Directory of Open Access Journals (Sweden)

    Djoni Haryadi Setiabudi

    2004-01-01

    Full Text Available Technology development had given people the chance to capture their memorable moments in video format. A high quality digital video is a result of a good editing process. Which in turn, arise the new need of an editor application. In accordance to the problem, here the process of making a simple application for video editing needs. The application development use the programming techniques often applied in multimedia applications, especially video. First part of the application will begin with the video file compression and decompression, then we'll step into the editing part of the digital video file. Furthermore, the application also equipped with the facilities needed for the editing processes. The application made with Microsoft Visual C++ with DirectX technology, particularly DirectShow. The application provides basic facilities that will help the editing process of a digital video file. The application will produce an AVI format file after the editing process is finished. Through the testing process of this application shows the ability of this application to do the 'cut' and 'insert' of video files in AVI, MPEG, MPG and DAT formats. The 'cut' and 'insert' process only can be done in static order. Further, the aplication also provide the effects facility for transition process in each clip. Lastly, the process of saving the new edited video file in AVI format from the application. Abstract in Bahasa Indonesia : Perkembangan teknologi memberi kesempatan masyarakat untuk mengabadikan saat - saat yang penting menggunakan video. Pembentukan video digital yang baik membutuhkan proses editing yang baik pula. Untuk melakukan proses editing video digital dibutuhkan program editor. Berdasarkan permasalahan diatas maka pada penelitian ini dibuat prototipe editor sederhana untuk video digital. Pembuatan aplikasi memakai teknik pemrograman di bidang multimedia, khususnya video. Perencanaan dalam pembuatan aplikasi tersebut dimulai dengan pembentukan

  16. Verification of the directivity index and other measures of directivity in predicting directional benefit

    Science.gov (United States)

    Dittberner, Andrew; Bentler, Ruth

    2005-09-01

    The relationship between various directivity measures and subject performance with directional microphone hearing aids was determined. Test devices included first- and second-order directional microphones. Recordings of sentences and noise (Hearing in Noise Test, HINT) were made through each test device in simple, complex, and anisotropic background noise conditions. Twenty-six subjects, with normal hearing, were administered the HINT test recordings, and directional benefit was computed. These measures were correlated to theoretical, free-field, and KEMAR DI values, as well as front-to-back ratios, in situ SNRs, and a newly proposed Db-SNR, wherein a predictive value of the SNR improvement is calculated as a function of the noise source incidence. The different predictive scores showed high correlation to the measured directional benefit scores in the complex (diffuse-like) background noise condition (r=0.89-0.97, pThe Db-SNR approach and the in situ SNR measures provided excellent prediction of subject performance in all background noise conditions (0.85-0.97, pthe predictive measures could account for the effects of reverberation on the speech signal (r=0.35-0.40, p<0.05).

  17. Direct-semidirect (DSD) codes

    International Nuclear Information System (INIS)

    Cvelbar, F.

    1999-01-01

    Recent codes for direct-semidirect (DSD) model calculations in the form of answers to a detailed questionnaire are reviewed. These codes include those embodying the classical DSD approach covering only the transitions to the bound states (RAF, HIKARI, and those of the Bologna group), as well as the code CUPIDO++ that also treats transitions to unbound states. (author)

  18. Direct solar-pumped lasers

    Science.gov (United States)

    Lee, J. H.; Shiu, Y. J.; Weaver, W. R.

    1980-01-01

    The feasibility of direct solar pumping of an iodine photodissociation laser at lambda = 1.315 microns was investigated. Threshold inversion density and effect of elevated temperature (up to 670 K) on the laser output were measured. These results and the concentration of solar radiation required for the solar pumped iodine laser are discussed.

  19. Entry: direct control or regulation?

    NARCIS (Netherlands)

    Perotti, E.; Vorage, M.

    2009-01-01

    We model a setting in which citizens form coalitions to seek preferential entry to a given market. The lower entry the higher firm profits and political contributions, but the lower social welfare. Politicians choose to either control entry directly and be illegally bribed, or regulate entry using a

  20. Direct Oral Anticoagulants and Women

    NARCIS (Netherlands)

    Cohen, Hannah; Arachchillage, Deepa R. J.; Beyer-Westendorf, Jan; Middeldorp, Saskia; Kadir, Rezan A.

    2016-01-01

    Direct oral anticoagulants (DOACs) provide an effective, safe, and convenient therapeutic alternative to warfarin and other vitamin K antagonists (VKAs), and are now established for a wide range of indications. The use of DOACs in women merits special consideration due to two main situations: first,

  1. Foreign direct investment in Hungary

    NARCIS (Netherlands)

    Hastenberg, Johannes Josephus Wilhelmus van

    1999-01-01

    Effecten op de modernisering van de industrie en de vraag naar arbeid Na de val van de Berlijnse muur in 1989 en het verdwijnen van het socialisme werd Hongarije een aantrekkelijke bestemming voor buitenlandse directe investeringen (FDI). De combinatie van marktpotentie, lage loonkosten en een

  2. Multi-directional productivity change

    DEFF Research Database (Denmark)

    Asmild, Mette; Balezentis, Tomas; Hougaard, Jens Leth

    2016-01-01

    In this paper we introduce an extension of the Malmquist total factor productivity index, which utilizes the Multi-directional Efficiency Analysis approach. This enables variable-specific analysis of productivity change as well as its components (efficiency change and technical change). The new...

  3. EU citizenship and direct taxation

    NARCIS (Netherlands)

    E.W. Ros (Erik)

    2017-01-01

    markdownabstractThe main question addressed in this study is: _How has the concept of EU citizenship influenced the legal autonomy of Member States; most notably in the field of direct taxation and are the implications of that influence on the tax autonomy of Member States acceptable?_

  4. Guide to Direct Consolidation Loans.

    Science.gov (United States)

    Department of Education, Washington, DC.

    Intended for financial aid counselors, this document provides guidelines to the Federal Direct Consolidation Loan Program for borrowers who are in school, as well as those in repayment, or in default. An introductory section explains the basics of the consolidated loan program, loan categories, and interest rates. Next, standards for borrower…

  5. Directivity of basic linear arrays

    DEFF Research Database (Denmark)

    Bach, Henning

    1970-01-01

    For a linear uniform array ofnelements, an expression is derived for the directivity as a function of the spacing and the phase constants. The cases of isotropic elements, collinear short dipoles, and parallel short dipoles are included. The formula obtained is discussed in some detail and contour...

  6. Directional Dependence in Developmental Research

    Science.gov (United States)

    von Eye, Alexander; DeShon, Richard P.

    2012-01-01

    In this article, we discuss and propose methods that may be of use to determine direction of dependence in non-normally distributed variables. First, it is shown that standard regression analysis is unable to distinguish between explanatory and response variables. Then, skewness and kurtosis are discussed as tools to assess deviation from…

  7. Evolutionary trends in directional hearing

    DEFF Research Database (Denmark)

    Carr, Catherine E; Christensen-Dalsgaard, Jakob

    2016-01-01

    Tympanic hearing is a true evolutionary novelty that arose in parallel within early tetrapods. We propose that in these tetrapods, selection for sound localization in air acted upon pre-existing directionally sensitive brainstem circuits, similar to those in fishes. Auditory circuits in birds...

  8. Electromagnetic direct implicit PIC simulation

    International Nuclear Information System (INIS)

    Langdon, A.B.

    1983-01-01

    Interesting modelling of intense electron flow has been done with implicit particle-in-cell simulation codes. In this report, the direct implicit PIC simulation approach is applied to simulations that include full electromagnetic fields. The resulting algorithm offers advantages relative to moment implicit electromagnetic algorithms and may help in our quest for robust and simpler implicit codes

  9. Breakdown of interdependent directed networks.

    Science.gov (United States)

    Liu, Xueming; Stanley, H Eugene; Gao, Jianxi

    2016-02-02

    Increasing evidence shows that real-world systems interact with one another via dependency connectivities. Failing connectivities are the mechanism behind the breakdown of interacting complex systems, e.g., blackouts caused by the interdependence of power grids and communication networks. Previous research analyzing the robustness of interdependent networks has been limited to undirected networks. However, most real-world networks are directed, their in-degrees and out-degrees may be correlated, and they are often coupled to one another as interdependent directed networks. To understand the breakdown and robustness of interdependent directed networks, we develop a theoretical framework based on generating functions and percolation theory. We find that for interdependent Erdős-Rényi networks the directionality within each network increases their vulnerability and exhibits hybrid phase transitions. We also find that the percolation behavior of interdependent directed scale-free networks with and without degree correlations is so complex that two criteria are needed to quantify and compare their robustness: the percolation threshold and the integrated size of the giant component during an entire attack process. Interestingly, we find that the in-degree and out-degree correlations in each network layer increase the robustness of interdependent degree heterogeneous networks that most real networks are, but decrease the robustness of interdependent networks with homogeneous degree distribution and with strong coupling strengths. Moreover, by applying our theoretical analysis to real interdependent international trade networks, we find that the robustness of these real-world systems increases with the in-degree and out-degree correlations, confirming our theoretical analysis.

  10. Predicting Market Direction from Direct Speech by Business Leaders

    OpenAIRE

    Drury, Brett M.; Almeida, José João

    2012-01-01

    Direct quotations from business leaders can communicate to the wider public the latent state of their organization as well as the beliefs of the organization's leaders. Candid quotes from business leaders can have dramatic effects upon the share price of their organization. For example, Gerald Ratner in 1991 stated that his company's products were crap and consequently his company (Ratners) lost in excess of 500 million pounds in market value. Information in quotes from business leaders can b...

  11. Rejuvenating direct modulation and direct detection for modern optical communications

    Science.gov (United States)

    Che, Di; Li, An; Chen, Xi; Hu, Qian; Shieh, William

    2018-02-01

    High-speed transoceanic optical fiber transmission using direct modulation (DM) and direct detection (DD) was one of the most stirring breakthroughs for telecommunication in 1990s, which drove the internet as a global phenomenon. However, the later evolution of optical coherent communications in 2000s gradually took over the long-haul applications, due to its superior optical spectral efficiency. Nowadays, DM-DD systems are dominant mainly in cost- and power-sensitive short-reach applications, because of its natural characteristics-the simplicity. This paper reviews the recent advances of DM-DD transceivers from both hardware and signal processing perspectives. It introduces a variety of modified DM and/or DD systems for 3 application scenarios: very-short-reach interconnect with little fiber channel impact; single or a few spans of fiber transmission up to several hundred km; and distance beyond the 2nd scenario. Besides the DM-DD and multi-dimension DM-DD with polarization diversity, this paper focuses on how to rejuvenate traditional DM and DD technologies in order to bridge the transmission application gap between DM-DD and coherent transceivers, using technologies such as dispersion compensation, signal field recovery from the intensity-only DD receiver, and complex direct modulation with coherent detection. More than 30 years since the birth, DM and DD still hold indispensable roles in modern optical communications.

  12. Dark matter spin determination with directional direct detection experiments

    Science.gov (United States)

    Catena, Riccardo; Conrad, Jan; Döring, Christian; Ferella, Alfredo Davide; Krauss, Martin B.

    2018-01-01

    If dark matter has spin 0, only two WIMP-nucleon interaction operators can arise as leading operators from the nonrelativistic reduction of renormalizable single-mediator models for dark matter-quark interactions. Based on this crucial observation, we show that about 100 signal events at next generation directional detection experiments can be enough to enable a 2 σ rejection of the spin 0 dark matter hypothesis in favor of alternative hypotheses where the dark matter particle has spin 1 /2 or 1. In this context, directional sensitivity is crucial since anisotropy patterns in the sphere of nuclear recoil directions depend on the spin of the dark matter particle. For comparison, about 100 signal events are expected in a CF4 detector operating at a pressure of 30 torr with an exposure of approximately 26,000 cubic-meter-detector days for WIMPs of 100 GeV mass and a WIMP-fluorine scattering cross section of 0.25 pb. Comparable exposures require an array of cubic meter time projection chamber detectors.

  13. Setting a personal career direction.

    Science.gov (United States)

    McCurdy, Fredrick A; Marcdante, Karen

    2003-01-01

    In summary, we believe that both you and your organization should have a set of core values, a well-defined mission (core purpose), and a vision of the future. Ideally, your projects and activities should be congruent with your mission and values, you should be pursuing your vision, and all of this should be congruent with the organization mission and values. Practically speaking, most individuals we have worked with over the years find themselves in two different groups at this point in the exercise. The minority find that their personal mission is not at all similar to the mission of their current organization and they find it necessary to seriously reevaluate their personal career direction. Sometimes, this results in them finding some other place to work. On the other hand, the majority discover their personal mission is in reasonable agreement with that of their organization. For both, this exercise has helped them clarify and better manage their personal career direction.

  14. Theory of direct interparticle action

    International Nuclear Information System (INIS)

    Vladimirov, Yu.S.; Turygin, A.Yu.

    1986-01-01

    Unusual point of view on the physical picture of the Universe and ratio between main physical categories is considered. Principal moments and theory peculiarities based on the conception of direct interparticle action are underlined. The direct interparticle action theory (DIAT) is considered from the position of choosing one or another axiomatics. At first the Fokker action principle is postulated there and then identical satisfiability of field equations is proved. All that relates to vacuum DIAT ignores and actions of matter formations are used as the basis. DIAT bears up against a global factor-account of absrbers of all surroundings (the Mach principle). The DIAT pretended to relativistic description of only additional concepts with the previously asigned space-time ratios. Concept for construction of the physical picture of the Universe, where classical space-time ratios being of secondary character, is suggested

  15. Sensing roughness and polish direction

    DEFF Research Database (Denmark)

    Jakobsen, Michael Linde; Olesen, Anders Sig; Larsen, Henning Engelbrecht

    2016-01-01

    As a part of the work carried out in a project supported by the Danish Council for Technology and Innovation, we have investigated the option of smoothing standard CNC-machined surfaces. In the process of constructing optical prototypes, involving custom-designed optics, the development cost...... and time consumption can become prohibitive in a research budget. Machining the optical surfaces directly is expensive and time consuming. Alternatively, a more standardized and cheaper machining method can be used, calling for the object to be manually polished. During the polishing process, the operator...... needs information about the RMS-value of the surface roughness and the current direction of the scratches introduced by the polishing process. The RMS-value indicates to the operator how far he is from the final finish, and the scratch orientation is often specified by the customer in order to avoid...

  16. Directed information measures in neuroscience

    CERN Document Server

    Vicente, Raul; Lizier, Joseph

    2014-01-01

    Analysis of information transfer has found rapid adoption in neuroscience, where a highly dynamic transfer of information continuously runs on top of the brain's slowly-changing anatomical connectivity. Measuring such transfer is crucial to understanding how flexible information routing and processing give rise to higher cognitive function. Directed Information Measures in Neuroscience reviews recent developments of concepts and tools for measuring information transfer, their application to neurophysiological recordings and analysis of interactions. Written by the most active researchers in the field the book discusses the state of the art, future prospects and challenges on the way to an efficient assessment of neuronal information transfer. Highlights include the theoretical quantification and practical estimation of information transfer, description of transfer locally in space and time, multivariate directed measures, information decomposition among a set of stimulus/responses variables, and the relation ...

  17. Future directions for nursing administration.

    Science.gov (United States)

    Poulin, M A

    1984-03-01

    As the age of centralization wanes, nurse executives must look ahead. The author, noting a terrain obscured by the increasing complexity of nursing practice, points out the advantages of decentralizing decision making and of providing a distinctive nursing stamp to research and administration theory. Nurse executives, trained in management from early in their professional formation, can provide enlightened direction and flexible support for tomorrow's opportunities.

  18. Direct search for dark matter

    Energy Technology Data Exchange (ETDEWEB)

    Yoo, Jonghee; /Fermilab

    2009-12-01

    Dark matter is hypothetical matter which does not interact with electromagnetic radiation. The existence of dark matter is only inferred from gravitational effects of astrophysical observations to explain the missing mass component of the Universe. Weakly Interacting Massive Particles are currently the most popular candidate to explain the missing mass component. I review the current status of experimental searches of dark matter through direct detection using terrestrial detectors.

  19. Effects of Directed Energy Weapons

    Science.gov (United States)

    1994-01-01

    S. Feld, Ronald E. McNair, and Stephen R. Wilk, “The Physics of Karate,” Scientific American 240, 150 (April, 1979). 103. See Kittel (note 18...References 1. Figure 4–1 was adapted from Stephen Cheung and Frederic H. Levien, Microwaves Made Simple: Principles and Applications. (Dedham, MA: Artech...Physics (New York: MC- Graw Hill, 1965). Effects of Directed Energy Weapons 258 16. The physical meaning of this integral is that the propagation path

  20. Dimensional crossover in directed percolation

    International Nuclear Information System (INIS)

    Chame, A.M.N.; Queiroz, S.L.A. de; Santos, Raimundo R. dos.

    1984-04-01

    We study the dimensional crossover in directed percolation in three dimensions. Bonds are allowed to have different concentrations along the three cartesian axes of the lattice. Through a Position Space Renormalization Group we obtain the phase-diagrama where non-percolating, 1-D, 2-D and 3-D percolating phases are present. We find that the isotropic fixed points are unstable with respect to anisotropy, thus driving the system into a different universality class. (author) [pt

  1. Medium effects in direct reactions

    International Nuclear Information System (INIS)

    Karakoc, M; Bertulani, C

    2013-01-01

    We discuss medium corrections of the nucleon-nucleon (NN) cross sections and their influence on direct reactions at intermediate energies ≳50 MeV/nucleon. The results obtained with free NN cross sections are compared with those obtained with a geometrical treatment of Pauli-blocking and Dirac-Bruecker methods. We show that medium corrections may lead to sizable modifications for collisions at intermediate energies and that they are more pronounced in reactions involving weakly bound nuclei.

  2. Directed Innovation of Business Models

    OpenAIRE

    Stelian Brad; Emilia Brad

    2016-01-01

    Business model innovation is an important issue to keep business competitive and increase company’s profits. Due to many market attractors, identification of appropriate paths of business model evolution is a painful and risky process. To improve decision’s effectiveness in this process, an architectural construct of analysis and conceptualization for business model innovation that combines directed evolution and blue ocean concepts is proposed in this paper under the name o...

  3. Direction of Heavy Water Projects

    International Nuclear Information System (INIS)

    1984-07-01

    Summary of the activities performed by the Heavy Water Projects Direction of the Argentine Atomic Energy Commission from 1950 to 1983. It covers: historical data; industrial plant (based on ammonia-hydrogen isotopic exchange); experimental plant (utilizing hydrogen sulfides-water process); Module-80 plant (2-3 tons per year experimental plant with national technology) and other related tasks on research and development (E.A.C.) [es

  4. Directional dependency of air sampling

    International Nuclear Information System (INIS)

    1994-01-01

    A field study was performed by Idaho State University-Environmental Monitoring Laboratory (EML) to examine the directional dependency of low-volume air samplers. A typical continuous low volume air sampler contains a sample head that is mounted on the sampler housing either horizontally through one of four walls or vertically on an exterior wall 'looking down or up.' In 1992, a field study was undertaken to estimate sampling error and to detect the directional effect of sampler head orientation. Approximately 1/2 mile downwind from a phosphate plant (continuous source of alpha activity), four samplers were positioned in identical orientation alongside one sampler configured with the sample head 'looking down'. At least five consecutive weekly samples were collected. The alpha activity, beta activity, and the Be-7 activity collected on the particulate filter were analyzed to determine sampling error. Four sample heads were than oriented to the four different horizontal directions. Samples were collected for at least five weeks. Analysis of the alpha data can show the effect of sampler orientation to a know near source term. Analysis of the beta and Be-7 activity shows the effect of sampler orientation to a ubiquitous source term

  5. Direct detection with dark mediators

    Energy Technology Data Exchange (ETDEWEB)

    Curtin, David; Surujon, Ze' ev [C. N. Yang Institute for Theoretical Physics, Stony Brook University, Stony Brook, NY 11794 (United States); Tsai, Yuhsin [Physics Department, University of California Davis, Davis, CA 95616 (United States)

    2014-11-10

    We introduce dark mediator Dark Matter (dmDM) where the dark and visible sectors are connected by at least one light mediator ϕ carrying the same dark charge that stabilizes DM. ϕ is coupled to the Standard Model via an operator q{sup ¯}qϕϕ{sup ⁎}/Λ, and to dark matter via a Yukawa coupling y{sub χ}χ{sup c¯}χϕ. Direct detection is realized as the 2→3 process χN→χ{sup ¯}Nϕ at tree-level for m{sub ϕ}≲10 keV and small Yukawa coupling, or alternatively as a loop-induced 2→2 process χN→χN. We explore the direct-detection consequences of this scenario and find that a heavy O(100 GeV) dmDM candidate fakes different O(10 GeV) standard WIMPs in different experiments. Large portions of the dmDM parameter space are detectable above the irreducible neutrino background and not yet excluded by any bounds. Interestingly, for the m{sub ϕ} range leading to novel direct detection phenomenology, dmDM is also a form of Self-Interacting Dark Matter (SIDM), which resolves inconsistencies between dwarf galaxy observations and numerical simulations.

  6. BNL Direct Wind Superconducting Magnets

    Energy Technology Data Exchange (ETDEWEB)

    Parker, B.; Anerella, M.; Escallier, J.; Ghosh, A.; Jain, A.; Marone, A.; Muratore, A.; Wanderer, P.

    2011-09-12

    BNL developed Direct Wind magnet technology is used to create a variety of complex multi-functional multi-layer superconducting coil structures without the need for creating custom production tooling and fixturing for each new project. Our Direct Wind process naturally integrates prestress into the coil structure so external coil collars and yokes are not needed; the final coil package transverse size can then be very compact. Direct Wind magnets are produced with very good field quality via corrections applied during the course of coil winding. The HERA-II and BEPC-II Interaction Region (IR) magnet, J-PARC corrector and Alpha antihydrogen magnetic trap magnets and our BTeV corrector magnet design are discussed here along with a full length ILC IR prototype magnet presently in production and the coils that were wound for an ATF2 upgrade at KEK. A new IR septum magnet design concept for a 6.2 T combined-function IR magnet for eRHIC, a future RHIC upgrade, is introduced here.

  7. Directional Darwinian Selection in proteins.

    Science.gov (United States)

    McClellan, David A

    2013-01-01

    Molecular evolution is a very active field of research, with several complementary approaches, including dN/dS, HON90, MM01, and others. Each has documented strengths and weaknesses, and no one approach provides a clear picture of how natural selection works at the molecular level. The purpose of this work is to present a simple new method that uses quantitative amino acid properties to identify and characterize directional selection in proteins. Inferred amino acid replacements are viewed through the prism of a single physicochemical property to determine the amount and direction of change caused by each replacement. This allows the calculation of the probability that the mean change in the single property associated with the amino acid replacements is equal to zero (H0: μ = 0; i.e., no net change) using a simple two-tailed t-test. Example data from calanoid and cyclopoid copepod cytochrome oxidase subunit I sequence pairs are presented to demonstrate how directional selection may be linked to major shifts in adaptive zones, and that convergent evolution at the whole organism level may be the result of convergent protein adaptations. Rather than replace previous methods, this new method further complements existing methods to provide a holistic glimpse of how natural selection shapes protein structure and function over evolutionary time.

  8. Direct reciprocity in structured populations.

    Science.gov (United States)

    van Veelen, Matthijs; García, Julián; Rand, David G; Nowak, Martin A

    2012-06-19

    Reciprocity and repeated games have been at the center of attention when studying the evolution of human cooperation. Direct reciprocity is considered to be a powerful mechanism for the evolution of cooperation, and it is generally assumed that it can lead to high levels of cooperation. Here we explore an open-ended, infinite strategy space, where every strategy that can be encoded by a finite state automaton is a possible mutant. Surprisingly, we find that direct reciprocity alone does not lead to high levels of cooperation. Instead we observe perpetual oscillations between cooperation and defection, with defection being substantially more frequent than cooperation. The reason for this is that "indirect invasions" remove equilibrium strategies: every strategy has neutral mutants, which in turn can be invaded by other strategies. However, reciprocity is not the only way to promote cooperation. Another mechanism for the evolution of cooperation, which has received as much attention, is assortment because of population structure. Here we develop a theory that allows us to study the synergistic interaction between direct reciprocity and assortment. This framework is particularly well suited for understanding human interactions, which are typically repeated and occur in relatively fluid but not unstructured populations. We show that if repeated games are combined with only a small amount of assortment, then natural selection favors the behavior typically observed among humans: high levels of cooperation implemented using conditional strategies.

  9. Direct utilization of geothermal energy

    International Nuclear Information System (INIS)

    Lund, J. W.

    2010-01-01

    The worldwide application of geothermal energy for direct utilization is reviewed. This paper is based on the world update for direct-use presented at the World Geothermal Congress 2010 in Bali, Indonesia (WGC2010) which also includes material presented at three world geothermal congresses in Italy, Japan and Turkey (WGC95, WGC2000 and WGC2005). This report is based on country update papers prepared for WGC2010 and data from other sources. Final update papers were received from 70 countries of which 66 reported some direct utilization of geothermal energy for WGC2010. Twelve additional countries were added to the list based on other sources of information. The 78 countries having direct utilization of geothermal energy, is a significant increase from the 72 reported in 2005, the 58 reported in 2000, and the 28 reported in 1995. An estimate of the installed thermal power for direct utilization at the end of 2009, reported from WGC2010 is 48,493 MW th , almost a 72 % increased over the 2005 data, growing at a compound rate of 11.4% annually with a capacity factor of 0.28. The thermal energy used is 423,830 TJ/year (117,740 GWh/yr), about a 55% increase over 2005, growing at a compound rate of 9.2% annually. The distribution of thermal energy used by category is approximately 47.2% for ground-source heat pumps, 25.8% for bathing and swimming (including balneology), 14.9% for space heating (of which 85% is for district heating), 5.5% for greenhouses and open ground heating, 2.8% for industrial process heating, 2.7% for aquaculture pond and raceway heating, 0.4% for agricultural drying, 0.5% for snow melting and cooling, and 0.2% for other uses. Energy savings amounted to 250 million barrels (38 million tonnes) of equivalent oil annually, preventing 33 million tonnes of carbon and 107 million tonnes of CO 2 being released to the atmosphere which includes savings in geothermal heat pump cooling (compared to using fuel oil to generate electricity). (author)

  10. Direct Utilization of Geothermal Energy

    Directory of Open Access Journals (Sweden)

    John W. Lund

    2010-08-01

    Full Text Available The worldwide application of geothermal energy for direct utilization is reviewed. This paper is based on the world update for direct-use presented at the World Geothermal Congress 2010 in Bali, Indonesia (WGC2010 [1] which also includes material presented at three world geothermal congresses in Italy, Japan and Turkey (WGC95, WGC2000 and WGC2005. This report is based on country update papers prepared for WGC2010 and data from other sources. Final update papers were received from 70 countries of which 66 reported some direct utilization of geothermal energy for WGC2010. Twelve additional countries were added to the list based on other sources of information. The 78 countries having direct utilization of geothermal energy, is a significant increase from the 72 reported in 2005, the 58 reported in 2000, and the 28 reported in 1995. An estimate of the installed thermal power for direct utilization at the end of 2009, reported from WGC2010 is 48,493 MWt, almost a 72 % increased over the 2005 data, growing at a compound rate of 11.4% annually with a capacity factor of 0.28. The thermal energy used is 423,830 TJ/year (117,740 GWh/yr, about a 55% increase over 2005, growing at a compound rate of 9.2% annually. The distribution of thermal energy used by category is approximately 47.2% for ground-source heat pumps, 25.8% for bathing and swimming (including balneology, 14.9% for space heating (of which 85% is for district heating, 5.5% for greenhouses and open ground heating, 2.8% for industrial process heating, 2.7% for aquaculture pond and raceway heating, 0.4% for agricultural drying, 0.5% for snow melting and cooling, and 0.2% for other uses. Energy savings amounted to 250 million barrels (38 million tonnes of equivalent oil annually, preventing 33 million tonnes of carbon and 107 million tonnes of CO2 being release to the atmosphere which includes savings in geothermal heat pump cooling (compared to using fuel oil to generate electricity.

  11. Entrance Counseling Guide for Direct Loan Borrowers

    Science.gov (United States)

    Federal Student Aid, US Department of Education, 2010

    2010-01-01

    This guide describes the four types of loans offered by the Direct Loan Program[SM]: (1) Direct Subsidized Loans; (2) Direct Unsubsidized Loans; (3) Direct PLUS Loans; and (4) Direct Consolidation Loans. Among the topics covered in the guide are: Use of Your Loan Money, The Master Promissory Note, How Your Loans Will Be Disbursed (Paid Out),…

  12. Current directions in radiopharmaceutical research

    Energy Technology Data Exchange (ETDEWEB)

    Mather, S J [Department of Nuclear Medicine, St. Bartholomew` s Hospital, London (United Kingdom)

    1998-08-01

    Much of current radiopharmaceutical research is directed towards the development of receptor-binding tracers which are targeted towards biochemical processes. These may be extra or intracellular in nature and hold promise for an imaging approach to tissue characterisation in-vivo. Many of these products are based on proteins which range in size from large monoclonal antibodies to small neuropeptides and share a radiolabelling chemistry based on the use of bifunctional chelating agents. Although developed initially for use with indium-111, considerations of cost and isotope availability have continued to direct the efforts of many researchers towards the use of technetium-99m. While polypeptide-based radiopharmaceuticals may be useful for imaging peripheral cell-surface receptors, access to sites of interest within the cell, or in the brain, requires the development of small lipophilic molecules with retained ability to interact with intracellular targets. The design and synthesis of these compounds presents a particular challenge to the radiopharmaceutical chemist which is being met through either a pendant or integrated approach to the use of technetium coordination with particular emphasis on technetium (v) cores. Progress continues to be made in the application of targeted radionuclide therapy particularly in the development of radiopharmaceuticals for the treatment of malignant bone disease. methods for labelling antibodies with a great variety of cytotoxic radionuclides have now been refined and their use for radioimmunotherapy in the treatment of haematological malignancies shows great promise. The major medical areas for application of these new radiopharmaceuticals will be in oncology, neurology and inflammation but the increasingly difficult regulatory climate in which drug development and health-care now operate will make it essential for researchers to direct their products toward specific clinical problems as well as biological targets. (author) 36 refs

  13. Direct mediation, duality and unification

    International Nuclear Information System (INIS)

    Abel, Steven; Khoze, Valentin V.

    2008-01-01

    It is well-known that in scenarios with direct gauge mediation of supersymmetry breaking the messenger fields significantly affect the running of Standard Model couplings and introduce Landau poles which are difficult to avoid. Among other things, this appears to remove any possibility of a meaningful unification prediction and is often viewed as a strong argument against direct mediation. We propose two ways that Seiberg duality can circumvent this problem. In the first, which we call 'deflected-unification', the SUSY-breaking hidden sector is a magnetic theory which undergoes a Seiberg duality to an electric phase. Importantly, the electric version has fewer fundamental degrees of freedom coupled to the MSSM compared to the magnetic formulation. This changes the β-functions of the MSSM gauge couplings so as to push their Landau poles above the unification scale. We show that this scenario is realised for recently suggested models of gauge mediation based on a metastable SCQD-type hidden sector directly coupled to MSSM. The second possibility for avoiding Landau poles, which we call 'dual-unification', begins with the observation that, if the mediating fields fall into complete SU(5) multiplets, then the MSSM+messengers exhibits a fake unification at unphysical values of the gauge couplings. We show that, in known examples of electric/magnetic duals, such a fake unification in the magnetic theory reflects a real unification in the electric theory. We therefore propose that the Standard Model could itself be a magnetic dual of some unknown electric theory in which the true unification takes place. This scenario maintains the unification prediction (and unification scale) even in the presence of Landau poles in the magnetic theory below the GUT scale. We further note that this dual realization of grand unification can explain why Nature appears to unify, but the proton does not decay.

  14. Current directions in radiopharmaceutical research

    International Nuclear Information System (INIS)

    Mather, S.J.

    1998-01-01

    Much of current radiopharmaceutical research is directed towards the development of receptor-binding tracers which are targeted towards biochemical processes. These may be extra or intracellular in nature and hold promise for an imaging approach to tissue characterisation in-vivo. Many of these products are based on proteins which range in size from large monoclonal antibodies to small neuropeptides and share a radiolabelling chemistry based on the use of bifunctional chelating agents. Although developed initially for use with indium-111, considerations of cost and isotope availability have continued to direct the efforts of many researchers towards the use of technetium-99m. While polypeptide-based radiopharmaceuticals may be useful for imaging peripheral cell-surface receptors, access to sites of interest within the cell, or in the brain, requires the development of small lipophilic molecules with retained ability to interact with intracellular targets. The design and synthesis of these compounds presents a particular challenge to the radiopharmaceutical chemist which is being met through either a pendant or integrated approach to the use of technetium coordination with particular emphasis on technetium (v) cores. Progress continues to be made in the application of targeted radionuclide therapy particularly in the development of radiopharmaceuticals for the treatment of malignant bone disease. methods for labelling antibodies with a great variety of cytotoxic radionuclides have now been refined and their use for radioimmunotherapy in the treatment of haematological malignancies shows great promise. The major medical areas for application of these new radiopharmaceuticals will be in oncology, neurology and inflammation but the increasingly difficult regulatory climate in which drug development and health-care now operate will make it essential for researchers to direct their products toward specific clinical problems as well as biological targets. (author)

  15. Heading in the right direction

    Energy Technology Data Exchange (ETDEWEB)

    Dutta, Ashok

    2011-01-15

    Statoil has developed a new directional technology which optimizes well positioning for unconsolidated geological formations, which addresses a crucial part for the implementation of a steam assisted gravity drainage (SAGD) program. This technology includes a rotary steerable system which, combined with an ultra-deep resistivity sensor, provides precise geosteering resulting therefore in in better well reservoir capture and characterization. Using this technique increases drilling efficiency, thus reducing the drilling time. The company's strategy is to provide cutting edge development to the oil sector and they have created a new research center in Calgary.

  16. Accurate determination of antenna directivity

    DEFF Research Database (Denmark)

    Dich, Mikael

    1997-01-01

    The derivation of a formula for accurate estimation of the total radiated power from a transmitting antenna for which the radiated power density is known in a finite number of points on the far-field sphere is presented. The main application of the formula is determination of directivity from power......-pattern measurements. The derivation is based on the theory of spherical wave expansion of electromagnetic fields, which also establishes a simple criterion for the required number of samples of the power density. An array antenna consisting of Hertzian dipoles is used to test the accuracy and rate of convergence...

  17. Direct synthesis of organic silicates

    International Nuclear Information System (INIS)

    Gismalla, Hana Hassan

    2000-06-01

    Tetraethoxysilane was prepared using the direct synthetic procedure in presence of magnesium ethoxide, tin tetrachloride and tin oxide as catalysts. Magnesium ethoxide was prepared firstly, identified by spectral analysis and then used in the preparation of tetraethoxysilane. The method adopted is reliable and significant as far as synthetic routes are concerned. The product obtained was analysed using infra-red spectroscopy and gas-liquid chromatography, these indicated that the final reaction product can be obtained in high yield and purity. Spectral analysis obtained are in good agreement with reported data for tetraethoxysilane. (Author)

  18. Boltzmann, Darwin and Directionality theory

    Energy Technology Data Exchange (ETDEWEB)

    Demetrius, Lloyd A., E-mail: ldemetr@oeb.harvard.edu

    2013-09-01

    Boltzmann’s statistical thermodynamics is a mathematical theory which relates the macroscopic properties of aggregates of interacting molecules with the laws of their interaction. The theory is based on the concept thermodynamic entropy, a statistical measure of the extent to which energy is spread throughout macroscopic matter. Macroscopic evolution of material aggregates is quantitatively explained in terms of the principle: Thermodynamic entropy increases as the composition of the aggregate changes under molecular collision. Darwin’s theory of evolution is a qualitative theory of the origin of species and the adaptation of populations to their environment. A central concept in the theory is fitness, a qualitative measure of the capacity of an organism to contribute to the ancestry of future generations. Macroscopic evolution of populations of living organisms can be qualitatively explained in terms of a neo-Darwinian principle: Fitness increases as the composition of the population changes under variation and natural selection. Directionality theory is a quantitative model of the Darwinian argument of evolution by variation and selection. This mathematical theory is based on the concept evolutionary entropy, a statistical measure which describes the rate at which an organism appropriates energy from the environment and reinvests this energy into survivorship and reproduction. According to directionality theory, microevolutionary dynamics, that is evolution by mutation and natural selection, can be quantitatively explained in terms of a directionality principle: Evolutionary entropy increases when the resources are diverse and of constant abundance; but decreases when the resource is singular and of variable abundance. This report reviews the analytical and empirical support for directionality theory, and invokes the microevolutionary dynamics of variation and selection to delineate the principles which govern macroevolutionary dynamics of speciation and

  19. The Strength of Direct Ties

    DEFF Research Database (Denmark)

    Claussen, Jörg; Falck, Oliver; Grosjean, Thorsten

    2012-01-01

    We analyze the economic effects of a developer's connectedness in the electronic game industry. Knowledge spillovers between developers are likely to be of special relevance in this knowledge-intensive and regionally concentrated industry. We calculate social network measures for a developer......'s connectedness to other developers at multiple points in time. In a regression in which we exploit within-career variation in social network measures, we find that the number of direct ties a developer has to other developers has a strong effect on both a game's revenues and critics' scores. The quality...... of indirect ties makes no additional contribution to the game's success....

  20. Direct Chlorination of Zircon Sand

    International Nuclear Information System (INIS)

    Dwiretnani Sudjoko; Budi Sulistyo; Pristi Hartati; Sunardjo

    2002-01-01

    It was investigated the direct chlorination of zircon sand in a unit chlorination equipment. The process was in semi batch. The product gas was scrubbed in aqueous NaOH. It was search the influence of time, ratio of reactant and size of particle sand to the concentration of Zr and Si in the product. From these research it was found that as the times, ratio of reactant increased, the concentration of Zr increased, but the concentration of Si decreased, while as grain size of zircon sand decreased the concentration of Zr decreased, but the concentration of Si increased. (author)

  1. Directed Assembly of Gold Nanoparticles

    DEFF Research Database (Denmark)

    Westerlund, Axel Rune Fredrik; Bjørnholm, Thomas

    2009-01-01

    As a complement to common "top-down" lithography techniques, "bottom-up" assembly techniques are emerging as promising tools to build nanoscale structures in a predictable way. Gold nanoparticles that are stable and relatively easy to synthesize are important building blocks in many such structures...... due to their useful optical and electronic properties. Programmed assembly of gold nanoparticles in one, two, and three dimensions is therefore of large interest. This review focuses on the progress from the last three years in the field of directed gold nanoparticle and nanorod assembly using...

  2. Directional synthetic aperture flow imaging

    DEFF Research Database (Denmark)

    Jensen, Jørgen Arendt; Nikolov, Svetoslav

    2004-01-01

    emissions using a number of defocused elements and a linear frequency modulated pulse (chirp) to improve the signal-to-noise ratio. The received signals are dynamically focused along the flow direction and these signals are used in a cross-correlation estimator for finding the velocity magnitude. The flow...... elements in each emission. A 20 us chirp was used during emission. The RF data were subsequently beamformed off-line and stationary echo canceling was performed. The 60 degrees flow with a peak velocity of 0.15 m/s was determined using 16 groups of 8 emissions and the relative standard deviation was 0...

  3. Boltzmann, Darwin and Directionality theory

    International Nuclear Information System (INIS)

    Demetrius, Lloyd A.

    2013-01-01

    Boltzmann’s statistical thermodynamics is a mathematical theory which relates the macroscopic properties of aggregates of interacting molecules with the laws of their interaction. The theory is based on the concept thermodynamic entropy, a statistical measure of the extent to which energy is spread throughout macroscopic matter. Macroscopic evolution of material aggregates is quantitatively explained in terms of the principle: Thermodynamic entropy increases as the composition of the aggregate changes under molecular collision. Darwin’s theory of evolution is a qualitative theory of the origin of species and the adaptation of populations to their environment. A central concept in the theory is fitness, a qualitative measure of the capacity of an organism to contribute to the ancestry of future generations. Macroscopic evolution of populations of living organisms can be qualitatively explained in terms of a neo-Darwinian principle: Fitness increases as the composition of the population changes under variation and natural selection. Directionality theory is a quantitative model of the Darwinian argument of evolution by variation and selection. This mathematical theory is based on the concept evolutionary entropy, a statistical measure which describes the rate at which an organism appropriates energy from the environment and reinvests this energy into survivorship and reproduction. According to directionality theory, microevolutionary dynamics, that is evolution by mutation and natural selection, can be quantitatively explained in terms of a directionality principle: Evolutionary entropy increases when the resources are diverse and of constant abundance; but decreases when the resource is singular and of variable abundance. This report reviews the analytical and empirical support for directionality theory, and invokes the microevolutionary dynamics of variation and selection to delineate the principles which govern macroevolutionary dynamics of speciation and

  4. Direct application of geothermal energy

    Energy Technology Data Exchange (ETDEWEB)

    Reistad, G.M.

    1980-01-01

    An overall treatment of direct geothermal applications is presented with an emphasis on the above-ground engineering. The types of geothermal resources and their general extent in the US are described. The potential market that may be served with geothermal energy is considered briefly. The evaluation considerations, special design aspects, and application approaches for geothermal energy use in each of the applications are considered. The present applications in the US are summarized and a bibliography of recent studies and applications is provided. (MHR)

  5. Directional dependence of binaural loudness

    DEFF Research Database (Denmark)

    Ellermeier, Wolfgang; Sivonen, Ville Pekka

    2006-01-01

    on binaural loudness summation, on the other hand, focuses on a highly artificial paradigm according to which unnatural combinations of sound pressure levels(such as monotic-diotic comparisons) are presented to listeners via headphones. In order to reconcile these two approaches, we recently started a series...... incidence angle, in order to relate the changes in actual at-ear exposure to the observed changes in loudness as a function of sound incidence. Combining the listening-test data with the physical measurements, an attempt was made to model the binaural summation underlying the directional loudness matches....

  6. A perspective on direct conversion

    Energy Technology Data Exchange (ETDEWEB)

    Lewis, W. B.

    1963-10-15

    As flowing energy, electricity is sought for its versatility. Its generation from some other flow or release of energy without mechanical power, or even sometimes heat, as intermediary is called direct conversion. The objective is high electrical output for minimum total cost and not always high conversion efficiency. The wide range of techniques embracing cryogenics and hot plasma derives from the special requirements of source, environment and application. Sources include solar and other radiation, nuclear fission and fusion, chemical energy and heat. Environments and applications range from space vehicles to submarines and from giant power networks to isolated buoys and pocket devices. (author)

  7. Direct Bonded Pontic (Laporan Kasus

    Directory of Open Access Journals (Sweden)

    Suhandi Sidjaja

    2015-10-01

    Full Text Available Advanced science and technology in dentistry enable dental practitioners to modified she bonding techniques in tooth replacement. A pontic made of composite resin bonded to etched enamel of the adjacent teeth can be used in the replacement of one missing anterior tooth with a virgin or sowed adpicent tooth. The advantages of this technique include a one visit treatment, cow cost, good esthetics, less side effects and easy repair or rebounding. Clinical evaluation showed a high success rate therefore with a proper diagnosis and a perfect skill of the direct bonded technique this treatment can be used as an alternative restoration.

  8. Direct measurements of neutrino masses

    Energy Technology Data Exchange (ETDEWEB)

    Holzschuh, E [Zurich Univ. (Switzerland). Inst. fuer Physik

    1996-11-01

    The direct measurements have so far given no indication for a nonzero (positive) mass of any of the three known neutrinos. The experiments measuring the tau and the muon neutrino are good shape. The tritium experiments are in an unfortunate situation. It is unclear to me whether the problems are experimental or theoretical or a combination of both. The electronic final states distribution have been calculated, but the results have never been tested experimentally. The most important question to be answered is about the validity of the sudden approximation. (author) 9 figs., 2 tabs., 16 refs.

  9. Studies of direct electroinsulating enamels

    International Nuclear Information System (INIS)

    Siwulski, S.; Gruszka, B.; Nocun, M.

    1998-01-01

    The results of studies on the influence of chemical composition of direct electroinsulating enamel on its properties were presented. The influence of alkaline Li 2 O, Na 2 O, K 2 O and adhesion promoting oxides CoO, NiO, CuO, MoO 3 on the frits properties were estimated. The characteristic temperature T g and T m as well as flowability were measured. The dielectric properties of frits and prepared enamels were also measured. Enamel substrates were prepared and tested for application in thick hybrid circuit technology. (author)

  10. A perspective on direct conversion

    International Nuclear Information System (INIS)

    Lewis, W.B.

    1963-10-01

    As flowing energy, electricity is sought for its versatility. Its generation from some other flow or release of energy without mechanical power, or even sometimes heat, as intermediary is called direct conversion. The objective is high electrical output for minimum total cost and not always high conversion efficiency. The wide range of techniques embracing cryogenics and hot plasma derives from the special requirements of source, environment and application. Sources include solar and other radiation, nuclear fission and fusion, chemical energy and heat. Environments and applications range from space vehicles to submarines and from giant power networks to isolated buoys and pocket devices. (author)

  11. Direct, rapid RNA sequence analysis

    International Nuclear Information System (INIS)

    Peattie, D.A.

    1987-01-01

    The original methods of RNA sequence analysis were based on enzymatic production and chromatographic separation of overlapping oligonucleotide fragments from within an RNA molecule followed by identification of the mononucleotides comprising the oligomer. Over the past decade the field of nucleic acid sequencing has changed dramatically, however, and RNA molecules now can be sequenced in a variety of more streamlined fashions. Most of the more recent advances in RNA sequencing have involved one-dimensional electrophoretic separation of 32 P-end-labeled oligoribonucleotides on polyacrylamide gels. In this chapter the author discusses two of these methods for determining the nucleotide sequences of RNA molecules rapidly: the chemical method and the enzymatic method. Both methods are direct and degradative, i.e., they rely on fragmatic and chemical approaches should be utilized. The single-strand-specific ribonucleases (A, T 1 , T 2 , and S 1 ) provide an efficient means to locate double-helical regions rapidly, and the chemical reactions provide a means to determine the RNA sequence within these regions. In addition, the chemical reactions allow one to assign interactions to specific atoms and to distinguish secondary interactions from tertiary ones. If the RNA molecule is small enough to be sequenced directly by the enzymatic or chemical method, the probing reactions can be done easily at the same time as sequencing reactions

  12. Direct methods in protein crystallography.

    Science.gov (United States)

    Karle, J

    1989-11-01

    It is pointed out that the 'direct methods' of phase determination for small-structure crystallography do not have immediate applicability to macromolecular structures. The term 'direct methods in macromolecular crystallography' is suggested to categorize a spectrum of approaches to macromolecular structure determination in which the analyses are characterized by the use of two-phase and higher-order-phase invariants. The evaluation of the invariants is generally obtained by the use of heavy-atom techniques. The results of a number of the more recent algebraic and probabilistic studies involving isomorphous replacement and anomalous dispersion thus become valid subjects for discussion here. These studies are described and suggestions are also presented concerning future applicability. Additional discussion concerns the special techniques of filtering, the use of non-crystallographic symmetry, some features of maximum entropy and attempts to apply phase-determining formulas to the refinement of macromolecular structure. It is noted that, in addition to the continuing remarkable progress in macromolecular crystallography based on the traditional applications of isomorphous replacement and anomalous dispersion, recent valuable advances have been made in the application of non-crystallographic symmetry, in particular, to virus structures and in applications of filtering. Good progress has also been reported in the application of exact linear algebra to multiple-wavelength anomalous-dispersion investigations of structures containing anomalous scatterers of only moderate scattering power.

  13. Broadband direct RF digitization receivers

    CERN Document Server

    Jamin, Olivier

    2014-01-01

    This book discusses the trade-offs involved in designing direct RF digitization receivers for the radio frequency and digital signal processing domains.  A system-level framework is developed, quantifying the relevant impairments of the signal processing chain, through a comprehensive system-level analysis.  Special focus is given to noise analysis (thermal noise, quantization noise, saturation noise, signal-dependent noise), broadband non-linear distortion analysis, including the impact of the sampling strategy (low-pass, band-pass), analysis of time-interleaved ADC channel mismatches, sampling clock purity and digital channel selection. The system-level framework described is applied to the design of a cable multi-channel RF direct digitization receiver. An optimum RF signal conditioning, and some algorithms (automatic gain control loop, RF front-end amplitude equalization control loop) are used to relax the requirements of a 2.7GHz 11-bit ADC. A two-chip implementation is presented, using BiCMOS and 65nm...

  14. Radial lean direct injection burner

    Science.gov (United States)

    Khan, Abdul Rafey; Kraemer, Gilbert Otto; Stevenson, Christian Xavier

    2012-09-04

    A burner for use in a gas turbine engine includes a burner tube having an inlet end and an outlet end; a plurality of air passages extending axially in the burner tube configured to convey air flows from the inlet end to the outlet end; a plurality of fuel passages extending axially along the burner tube and spaced around the plurality of air passage configured to convey fuel from the inlet end to the outlet end; and a radial air swirler provided at the outlet end configured to direct the air flows radially toward the outlet end and impart swirl to the air flows. The radial air swirler includes a plurality of vanes to direct and swirl the air flows and an end plate. The end plate includes a plurality of fuel injection holes to inject the fuel radially into the swirling air flows. A method of mixing air and fuel in a burner of a gas turbine is also provided. The burner includes a burner tube including an inlet end, an outlet end, a plurality of axial air passages, and a plurality of axial fuel passages. The method includes introducing an air flow into the air passages at the inlet end; introducing a fuel into fuel passages; swirling the air flow at the outlet end; and radially injecting the fuel into the swirling air flow.

  15. Direct dating of human fossils.

    Science.gov (United States)

    Grün, Rainer

    2006-01-01

    The methods that can be used for the direct dating of human remains comprise of radiocarbon, U-series, electron spin resonance (ESR), and amino acid racemization (AAR). This review gives an introduction to these methods in the context of dating human bones and teeth. Recent advances in ultrafiltration techniques have expanded the dating range of radiocarbon. It now seems feasible to reliably date bones up to 55,000 years. New developments in laser ablation mass spectrometry permit the in situ analysis of U-series isotopes, thus providing a rapid and virtually non-destructive dating method back to about 300,000 years. This is of particular importance when used in conjunction with non-destructive ESR analysis. New approaches in AAR analysis may lead to a renaissance of this method. The potential and present limitations of these direct dating techniques are discussed for sites relevant to the reconstruction of modern human evolution, including Florisbad, Border Cave, Tabun, Skhul, Qafzeh, Vindija, Banyoles, and Lake Mungo. (c) 2006 Wiley-Liss, Inc.

  16. Plasma dark matter direct detection

    Energy Technology Data Exchange (ETDEWEB)

    Clarke, J.D.; Foot, R., E-mail: j.clarke5@pgrad.unimelb.edu.au, E-mail: rfoot@unimelb.edu.au [ARC Centre of Excellence for Particle Physics at the Terascale, School of Physics, University of Melbourne, Victoria 3010 Australia (Australia)

    2016-01-01

    Dark matter in spiral galaxies like the Milky Way may take the form of a dark plasma. Hidden sector dark matter charged under an unbroken U(1)' gauge interaction provides a simple and well defined particle physics model realising this possibility. The assumed U(1)' neutrality of the Universe then implies (at least) two oppositely charged dark matter components with self-interactions mediated via a massless 'dark photon' (the U(1)' gauge boson). In addition to nuclear recoils such dark matter can give rise to keV electron recoils in direct detection experiments. In this context, the detailed physical properties of the dark matter plasma interacting with the Earth is required. This is a complex system, which is here modelled as a fluid governed by the magnetohydrodynamic equations. These equations are numerically solved for some illustrative examples, and implications for direct detection experiments discussed. In particular, the analysis presented here leaves open the intriguing possibility that the DAMA annual modulation signal is due primarily to electron recoils (or even a combination of electron recoils and nuclear recoils). The importance of diurnal modulation (in addition to annual modulation) as a means of probing this kind of dark matter is also emphasised.

  17. Multi-step direct reactions

    International Nuclear Information System (INIS)

    Koning, A.J.

    1992-07-01

    In recent years a variety of statistical theories has been developed concerning multistep direct (MSD) nuclear reactions. In addition, dominant in applications is a whole class of semiclassical models that may be subsumed under the heading of 'generalized exciton models'; these are basically MSD-type extensions on top of compound-like concepts. In this report the relation between their underlying statistical MSD-postulates are highlighted. A command framework is sketched that enables to generate the various MSD theories through assigning statistical properties to different parts of the nuclear Hamiltonian. Then it is shown that distinct forms of nuclear randomness are embodied in the mentioned theories. All these theories appear to be very similar at a qualitative level. In order to explain the high energy-tails and forward-peaked angular distribution typical for particles emitted in MSD reactions, it is imagined that the incident continuum particle stepwise looses its energy and direction in a sequence of collisions, thereby creating new particle-hole pairs in the target system. At each step emission may take place. The statistical aspect comes in because many continuum states are involved in the process. These are supposed to display chaotic behavior, the associated randomness assumption giving rise to important simplifications in the expression for MSD emission cross sections. This picture suggests that mentioned MSD models can be interpreted as a variant of essentially one and the same theory. 113 refs.; 25 figs.; 9 tabs

  18. Current Direct Neutrino Mass Experiments

    Directory of Open Access Journals (Sweden)

    G. Drexlin

    2013-01-01

    Full Text Available In this contribution, we review the status and perspectives of direct neutrino mass experiments, which investigate the kinematics of β-decays of specific isotopes (3H, 187Re, 163Ho to derive model-independent information on the averaged electron (antineutrino mass. After discussing the kinematics of β-decay and the determination of the neutrino mass, we give a brief overview of past neutrino mass measurements (SN1987a-ToF studies, Mainz and Troitsk experiments for 3H, cryobolometers for 187Re. We then describe the Karlsruhe Tritium Neutrino (KATRIN experiment currently under construction at Karlsruhe Institute of Technology, which will use the MAC-E-Filter principle to push the sensitivity down to a value of 200 meV (90% C.L.. To do so, many technological challenges have to be solved related to source intensity and stability, as well as precision energy analysis and low background rate close to the kinematic endpoint of tritium β-decay at 18.6 keV. We then review new approaches such as the MARE, ECHO, and Project8 experiments, which offer the promise to perform an independent measurement of the neutrino mass in the sub-eV region. Altogether, the novel methods developed in direct neutrino mass experiments will provide vital information on the absolute mass scale of neutrinos.

  19. Boltzmann, Darwin and Directionality theory

    Science.gov (United States)

    Demetrius, Lloyd A.

    2013-09-01

    Boltzmann’s statistical thermodynamics is a mathematical theory which relates the macroscopic properties of aggregates of interacting molecules with the laws of their interaction. The theory is based on the concept thermodynamic entropy, a statistical measure of the extent to which energy is spread throughout macroscopic matter. Macroscopic evolution of material aggregates is quantitatively explained in terms of the principle: Thermodynamic entropy increases as the composition of the aggregate changes under molecular collision. Darwin’s theory of evolution is a qualitative theory of the origin of species and the adaptation of populations to their environment. A central concept in the theory is fitness, a qualitative measure of the capacity of an organism to contribute to the ancestry of future generations. Macroscopic evolution of populations of living organisms can be qualitatively explained in terms of a neo-Darwinian principle: Fitness increases as the composition of the population changes under variation and natural selection. Directionality theory is a quantitative model of the Darwinian argument of evolution by variation and selection. This mathematical theory is based on the concept evolutionary entropy, a statistical measure which describes the rate at which an organism appropriates energy from the environment and reinvests this energy into survivorship and reproduction. According to directionality theory, microevolutionary dynamics, that is evolution by mutation and natural selection, can be quantitatively explained in terms of a directionality principle: Evolutionary entropy increases when the resources are diverse and of constant abundance; but decreases when the resource is singular and of variable abundance. This report reviews the analytical and empirical support for directionality theory, and invokes the microevolutionary dynamics of variation and selection to delineate the principles which govern macroevolutionary dynamics of speciation and

  20. 75 FR 53611 - Direct Investment Surveys: BE-577, Quarterly Survey of U.S. Direct Investment Abroad-Direct...

    Science.gov (United States)

    2010-09-01

    ...] RIN 0691-AA75 Direct Investment Surveys: BE-577, Quarterly Survey of U.S. Direct Investment Abroad--Direct Transactions of U.S. Reporter With Foreign Affiliate AGENCY: Bureau of Economic Analysis, Commerce...-577 quarterly survey of U.S. direct investment abroad. The survey is conducted quarterly and obtains...

  1. Together in the same direction

    CERN Multimedia

    2013-01-01

    It’s sometimes difficult to explain the nature of global collaboration in particle physics: how fierce competition coexists with collaboration, and how, whatever our differences, we all pull in the same direction. But this week gave us two strong examples.   Firstly, on Wednesday, the Technical Design Report (TDR) for the International Linear Collider (ILC) was officially delivered to the International Committee for Future Accelerators, ICFA, the global body that oversees the development of major projects in particle physics. This event marks the culmination of years of effort through close global collaboration between labs around the world. It has seen tough collective decisions being taken between competing technologies, with all participating labs lining up behind the chosen option. And on Wednesday this week, it saw the linear collider community choosing CERN as one of the three venues for the official handover, despite the fact that CERN was not one of the original core labs ...

  2. Multi-directional program efficiency

    DEFF Research Database (Denmark)

    Asmild, Mette; Balezentis, Tomas; Hougaard, Jens Leth

    2016-01-01

    The present paper analyses both managerial and program efficiencies of Lithuanian family farms, in the tradition of Charnes et al. (Manag Sci 27(6):668–697, 1981) but with the important difference that multi-directional efficiency analysis rather than the traditional data envelopment analysis...... approach is used to estimate efficiency. This enables a consideration of input-specific efficiencies. The study shows clear differences between the efficiency scores on the different inputs as well as between the farm types of crop, livestock and mixed farms respectively. We furthermore find that crop...... farms have the highest program efficiency, but the lowest managerial efficiency and that the mixed farms have the lowest program efficiency (yet not the highest managerial efficiency)....

  3. New directions in gas processing

    International Nuclear Information System (INIS)

    Anon.

    1996-01-01

    Papers presented at the Insight conference held on January 30, 1996 in Calgary, Alberta, were contained in this volume. The conference was devoted to a discussion of new directions in the gas processing business, the changing business environment, new processing technologies, and means by which current facilities agreements can be adapted to the new commercial reality. High operating costs which have resulted in the downsizing and restructuring of the industry, and partnering with a third party in the gathering and processing operations, with apparently beneficial result both to plant owners, as well to third party processors, received the most attention. The relationship between the gas processor and the gas producer as they relate to the Petroleum Joint Venture Association (PJVA) Gas Processing Agreement, which defines the obligations of third parties, was the center of discussion. Regulatory changes and the industry's response to the changes was also on the agenda. Refs., tabs., figs

  4. Direct reconstruction of dark energy.

    Science.gov (United States)

    Clarkson, Chris; Zunckel, Caroline

    2010-05-28

    An important issue in cosmology is reconstructing the effective dark energy equation of state directly from observations. With so few physically motivated models, future dark energy studies cannot only be based on constraining a dark energy parameter space. We present a new nonparametric method which can accurately reconstruct a wide variety of dark energy behavior with no prior assumptions about it. It is simple, quick and relatively accurate, and involves no expensive explorations of parameter space. The technique uses principal component analysis and a combination of information criteria to identify real features in the data, and tailors the fitting functions to pick up trends and smooth over noise. We find that we can constrain a large variety of w(z) models to within 10%-20% at redshifts z≲1 using just SNAP-quality data.

  5. GLOBALIZATION AND FOREIGN DIRECT INVESTMENTS

    Directory of Open Access Journals (Sweden)

    Elena Chirilă – Donciu

    2013-07-01

    Full Text Available Mobilizing financial resources to cover investment needs is a concern of all countries, developed or developing ones, of consolidated market economies or emerging ones. A distinctive characteristic of Global Economy over the last few decades has been the rising rate and impressive increase in Foreign Direct Investment (FDI. The purpose of this research is to analyse global FDI inflows in Europe and in Romania. The results of the research support the idea that the balance of economic power is changing in the world economy and the countries that own a stable and solid industrial base are at an advantage. The new trends determined by the economic crisis in the field of FDI refer to the growing percentage of developing and emerging countries in the global flows of FDI.

  6. Direct Wittig Olefination of Alcohols.

    Science.gov (United States)

    Li, Qiang-Qiang; Shah, Zaher; Qu, Jian-Ping; Kang, Yan-Biao

    2018-01-05

    A base-promoted transition metal-free approach to substituted alkenes using alcohols under aerobic conditions using air as the inexpensive and clean oxidant is described. Aldehydes are relatively difficult to handle compared to corresponding alcohols due to their volatility and penchant to polymerize and autoxidize. Wittig ylides are easily oxidized to aldehydes and consequently form homo-olefination products. By the strategy of simultaneously in situ generation of ylides and aldehydes, for the first time, alcohols are directly transferred to olefins with no need of prepreparation of either aldehydes or ylides. Thus, the di/monocontrollable olefination of diols is accomplished. This synthetically practical method has been applied in the gram-scale synthesis of pharmaceuticals, such as DMU-212 and resveratrol from alcohols.

  7. Direct Reduction of Iron Ore

    Science.gov (United States)

    Small, M.

    1981-04-01

    In the search for a pure, available iron source, steelmakers are focusing their attention on Directly Reduced Iron (DRI). This material is produced by the reaction of a low gangue iron ore with a hydrocarbonaceous substance. Commercially, DRI is generated in four different reactors: shaft (moving-bed), rotary kiln, fluidized bed, and retort (fixed-bed). Annual worldwide production capacity approaches 33 million metric tons. Detailed assessments have been made of the uses of DRI, especially as a substitute for scrap in electric furnace (EF) steelmaking. DRI is generally of a quality superior to current grades of scrap, with steels produced more efficiently in the EF and containing lower levels of impurities. However, present economics favor EF steel production with scrap. But this situation could change within this decade because of a developing scarcity of good quality scrap.

  8. Reasoning about cardinal directions between extended objects

    OpenAIRE

    Liu, Weiming; Zhang, Xiaotong; Li, Sanjiang; Ying, Mingsheng

    2010-01-01

    Direction relations between extended spatial objects are important commonsense knowledge. Recently, Goyal and Egenhofer proposed a formal model, known as Cardinal Direction Calculus (CDC), for representing direction relations between connected plane regions. CDC is perhaps the most expressive qualitative calculus for directional information, and has attracted increasing interest from areas such as artificial intelligence, geographical information science, and image retrieval. Given a network ...

  9. Invariance of directed spaces and persistence

    DEFF Research Database (Denmark)

    2006-01-01

    With motivations arising from concurrency theory within Computer Science, a new field of research, directed algebraic topology, has emerged. The main characteristic is, that it involves spaces of "directed paths'' (or timed paths, executions) in a "directed space''; these directed paths can be co...

  10. 40 CFR 73.72 - Direct sales.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 16 2010-07-01 2010-07-01 false Direct sales. 73.72 Section 73.72... ALLOWANCE SYSTEM Auctions, Direct Sales, and Independent Power Producers Written Guarantee § 73.72 Direct sales. Allowances that were formerly part of the direct sale program, which has been terminated under...

  11. Isomorphisms and traversability of directed path graphs

    NARCIS (Netherlands)

    Broersma, Haitze J.; Li, Xueliang; Li, X.

    1998-01-01

    The concept of a line digraph is generalized to that of a directed path graph. The directed path graph $\\forw P_k(D)$ of a digraph $D$ is obtained by representing the directed paths on $k$ vertices of $D$ by vertices. Two vertices are joined by an arc whenever the corresponding directed paths in $D$

  12. Direct strip casting of steel - historical perspective and future direction

    International Nuclear Information System (INIS)

    Manohar, P.A.; Hunter, A.; Ferry, M.

    2000-01-01

    The commercialisation of direct strip casting (DSC) of steel represents the realisation of a dream cherished by engineers for over one hundred and fifty years. The story of the global competition for DSC of steel, that has ingredients of romanticism of chasing of a dream, adventure and intrigue, is being played out across continents over dozens of decades with an interplay of setbacks and successes. At this stage, DSC is set to make a profound impact on the steelmaking landscape. This paper reviews the important milestones in this compelling story, presents the current status and then gazes into the crystal ball in an attempt to predict which turn the story may take in the near future. The constraints and critical challenges for the successful commercialisation of DSC are highlighted. Recent results are discussed relating the production process to quality control and properties of unalloyed, low carbon strip-cast steels. future metallurgical challenges include a better understanding of solidification mechanism during high-speed casting and secondary processing variables affecting the final microstructure of austenitic grains

  13. Direct digital conversion detector technology

    Science.gov (United States)

    Mandl, William J.; Fedors, Richard

    1995-06-01

    Future imaging sensors for the aerospace and commercial video markets will depend on low cost, high speed analog-to-digital (A/D) conversion to efficiently process optical detector signals. Current A/D methods place a heavy burden on system resources, increase noise, and limit the throughput. This paper describes a unique method for incorporating A/D conversion right on the focal plane array. This concept is based on Sigma-Delta sampling, and makes optimum use of the active detector real estate. Combined with modern digital signal processors, such devices will significantly increase data rates off the focal plane. Early conversion to digital format will also decrease the signal susceptibility to noise, lowering the communications bit error rate. Computer modeling of this concept is described, along with results from several simulation runs. A potential application for direct digital conversion is also reviewed. Future uses for this technology could range from scientific instruments to remote sensors, telecommunications gear, medical diagnostic tools, and consumer products.

  14. Direct anti-HCV agents

    Directory of Open Access Journals (Sweden)

    Xingquan Zhang

    2016-01-01

    Full Text Available Unlike human immunodeficiency virus (HIV and hepatitis B virus (HBV, hepatitis C virus (HCV infection is a curable disease. Current direct antiviral agent (DAA targets are focused on HCV NS3/4A protein (protease, NS5B protein (polymerase and NS5A protein. The first generation of DAAs includes boceprevir and telaprevir, which are protease inhibitors and were approved for clinical use in 2011. The cure rate for genotype 1 patients increased from 45% to 70% when boceprevir or telaprevir was added to standard PEG-IFN/ribavirin. More effective and less toxic second generation DAAs supplanted these drugs by 2013. The second generation of DAAs includes sofosbuvir (Sovaldi, simeprevir (Olysio, and fixed combination medicines Harvoni and Viekira Pak. These drugs increase cure rates to over 90% without the need for interferon and effectively treat all HCV genotypes. With these drugs the “cure HCV” goal has become a reality. Concerns remain about drug resistance mutations and the high cost of these drugs. The investigation of new HCV drugs is progressing rapidly; fixed dose combination medicines in phase III clinical trials include Viekirax, asunaprevir+daclatasvir+beclabuvir, grazoprevir+elbasvir and others.

  15. Direct probability mapping of contaminants

    International Nuclear Information System (INIS)

    Rautman, C.A.

    1993-01-01

    Exhaustive characterization of a contaminated site is a physical and practical impossibility. Descriptions of the nature, extent, and level of contamination, as well as decisions regarding proposed remediation activities, must be made in a state of uncertainty based upon limited physical sampling. Geostatistical simulation provides powerful tools for investigating contaminant levels, and in particular, for identifying and using the spatial interrelationships among a set of isolated sample values. This additional information can be used to assess the likelihood of encountering contamination at unsampled locations and to evaluate the risk associated with decisions to remediate or not to remediate specific regions within a site. Past operation of the DOE Feed Materials Production Center has contaminated a site near Fernald, Ohio, with natural uranium. Soil geochemical data have been collected as part of the Uranium-in-Soils Integrated Demonstration Project. These data have been used to construct a number of stochastic images of potential contamination for parcels approximately the size of a selective remediation unit. Each such image accurately reflects the actual measured sample values, and reproduces the univariate statistics and spatial character of the extant data. Post-processing of a large number of these equally likely, statistically similar images produces maps directly showing the probability of exceeding specified levels of contamination. Evaluation of the geostatistical simulations can yield maps representing the expected magnitude of the contamination for various regions and other information that may be important in determining a suitable remediation process or in sizing equipment to accomplish the restoration

  16. Future Directions in Ultraviolet Spectroscopy

    Science.gov (United States)

    Sonneborn, George (Editor); Moos, Warren; VanSteenberg, Michael

    2009-01-01

    The 'Future Directions in Ultraviolet Spectroscopy' conference was inspired by the accomplishments of the Far Ultraviolet Spectroscopic Explorer (FUSE) Mission. The FUSE mission was launched in June 1999 and spent over eight years exploring the far-ultraviolet universe, gathering over 64 million seconds of high-resolution spectral data on nearly 3000 astronomical targets. The goal of this conference was not only to celebrate the accomplishments of FUSE, but to look toward the future and understand the major scientific drivers for the ultraviolet capabilities of the next generation fo space observatories. Invited speakers presented discussions based on measurements made by FUSE and other ultraviolet instruments, assessed their connection with measurements made with other techniques and, where appropriate, discussed the implications of low-z measurements for high-z phenomena. In addition to the oral presentations, many participants presented poster papers. The breadth of these presentation made it clear that much good science is still in progress with FUSE data and that these result will continue to have relevance in many scientific areas.

  17. New directions for veterinary technology.

    Science.gov (United States)

    Chadderdon, Linda M; Lloyd, James W; Pazak, Helene E

    2014-01-01

    Veterinary technology has generally established itself well in companion-animal and mixed-animal veterinary medical practice, but the career's growth trajectory is uncertain. Michigan State University (MSU) convened a national conference, "Creating the Future of Veterinary Technology-A National Dialogue," in November 2011 to explore ways to elevate the veterinary technician/technologist's role in the veterinary medical profession and to identify new directions in which the career could expand. Veterinary technicians/technologists might advance their place in private practice by not only improving their clinical skills, but by also focusing on areas such as practice management, leadership training, business training, conflict resolution, information technology, and marketing/communications. Some new employment settings for veterinary technicians/technologists include more participation within laboratory animal medicine and research, the rural farm industry, regulatory medicine, and shelter medicine. Achieving these ends would call for new training options beyond the current 2-year and 4-year degree programs. Participants suggested specialty training programs, hybrid programs of various types, online programs, veterinary technician residency programs of 12-18 months, and more integration of veterinary technician/technology students and veterinary medicine students at colleges of veterinary medicine.

  18. Laboratory directed research and development

    Energy Technology Data Exchange (ETDEWEB)

    1991-11-15

    The purposes of Argonne's Laboratory Directed Research and Development (LDRD) Program are to encourage the development of novel concepts, enhance the Laboratory's R D capabilities, and further the development of its strategic initiatives. Among the aims of the projects supported by the Program are establishment of engineering proof-of-principle''; development of an instrumental prototype, method, or system; or discovery in fundamental science. Several of these project are closely associated with major strategic thrusts of the Laboratory as described in Argonne's Five Year Institutional Plan, although the scientific implications of the achieved results extend well beyond Laboratory plans and objectives. The projects supported by the Program are distributed across the major programmatic areas at Argonne. Areas of emphasis are (1) advanced accelerator and detector technology, (2) x-ray techniques in biological and physical sciences, (3) advanced reactor technology, (4) materials science, computational science, biological sciences and environmental sciences. Individual reports summarizing the purpose, approach, and results of projects are presented.

  19. Some directions in ecological theory.

    Science.gov (United States)

    Kendall, Bruce E

    2015-12-01

    The role of theory within ecology has changed dramatically in recent decades. Once primarily a source of qualitative conceptual framing, ecological theories and models are now often used to develop quantitative explanations of empirical patterns and to project future dynamics of specific ecological systems. In this essay, I recount my own experience of this transformation, in which accelerating computing power and the widespread incorporation of stochastic processes into ecological theory combined to create some novel integration of mathematical and statistical models. This stronger integration drives theory towards incorporating more biological realism, and I explore ways in which we can grapple with that realism to generate new general theoretical insights. This enhanced realism, in turn, may lead to frameworks for projecting ecological responses to anthropogenic change, which is, arguably, the central challenge for 21st-century ecology. In an era of big data and synthesis, ecologists are increasingly seeking to infer causality from observational data; but conventional biometry provides few tools for this project. This is a realm where theorists can and should play an important role, and I close by pointing towards some analytical and philosophical approaches developed in our sister discipline of economics that address this very problem. While I make no grand prognostications about the likely discoveries of ecological theory over the coming century, you will find in this essay a scattering of more or less far-fetched ideas that I, at least, think are interesting and (possibly) fruitful directions for our field.

  20. Low backlash direct drive actuator

    Science.gov (United States)

    Kuklo, Thomas C.

    1994-01-01

    A low backlash direct drive actuator is described which comprises a motor such as a stepper motor having at least 200 steps per revolution; a two part hub assembly comprising a drive hub coaxially attached to the shaft of the motor and having a plurality of drive pins; a driven hub having a plurality of bores in one end thereof in alignment with the drive pins in the drive hub and a threaded shaft coaxially mounted in an opposite end of the driven hub; and a housing having a central bore therein into which are fitted the drive hub and driven hub, the housing having a motor mount on one end thereof to which is mounted the stepper motor, and a closed end portion with a threaded opening therein coaxial with the central bore in the housing and receiving therein the threaded shaft attached to the driven hub. Limit switches mounted to the housing cooperate with an enlarged lip on the driven hub to limit the lateral travel of the driven hub in the housing, which also acts to limit the lateral travel of the threaded shaft which functions as a lead screw.

  1. DIRECT INVESTMENT ON REGIONAL MARKETS

    Directory of Open Access Journals (Sweden)

    LIVIU NEAMŢU

    2013-08-01

    Full Text Available Foreign direct investment are that category of investments that allow participation in leadership andeffective control of the companies in which it invests. It's so new firms, as well as the establishment ofinternational operations of the company through expansion of existing operations. Typically, the companyincurred in a market that is confined to a distinct geographical area, but the limits of market changes. Thechange can be the result of higher management decisions on market opening and development of a newtechnology or product. Markets with a lower level of development are likely to attract a higher level of directinvestments than those in more developed countries. The specific reasons behind the decision of a company toinvest abroad are operating efficiency, reduce risk, market development and Government policy in the hostcountry. Transnational corporations are large conglomerates which consists of the parent company and itssubsidiaries/branches, both in the country of residence and abroad. Transnational corporations affect stronglyboth the production and the world of international economic relations. This influence is determined by themotivations of expansion that they promote. The expansion of transnational corporations has as satisfying"ambitions" of global expansion, and impulsionate getting supraprofiturilor. The strength of these structures isbased on maximizing profits.

  2. Modern Directions for Potentiometric Sensors

    Science.gov (United States)

    Bakker, Eric; Chumbimuni-Torres, Karin

    2009-01-01

    This paper gives an overview of the newest developments of polymeric membrane ion-selective electrodes. A short essence of the underlying theory is given, emphasizing how the electromotive force may be used to assess binding constants of the ionophore, and how the selectivity and detection limit are related to the underlying membrane processes. The recent developments in lowering the detection limits of ISEs are described, including recent approaches of developing all solid state ISEs, and breakthroughs in detecting ultra-small quantities of ions at low concentrations. These developments have paved the way to use potentiometric sensors as in ultra-sensitive affinity bioanalysis in conjunction with nanoparticle labels. Recent results establish that potentiometry compares favorably to electrochemical stripping analysis. Other new developments with ion-selective electrodes are also described, including the concept of backside calibration potentiometry, controlled current coulometry, pulsed chronopotentiometry, and localized flash titration with ion-selective membranes to design sensors for the direct detection of total acidity without net sample perturbation. These developments have further opened the field for exciting new possibilities and applications. PMID:19890473

  3. The direct aromatization of methane

    Energy Technology Data Exchange (ETDEWEB)

    Marcelin, G.; Oukaci, R.; Migone, R.A.; Kazi, A.M. [Altamira Instruments, Pittsburgh, PA (United States)

    1995-12-31

    The thermal decomposition of methane shows significant potential as a process for the production of higher unsaturated and aromatic hydrocarbons when the extent of the reaction is limited. Thermodynamic calculations have shown that when the reaction is limited to the formation of C{sub 2} to C{sub 10} products, yields of aromatics can exceed 40% at temperatures of 1200{degrees}C. Preliminary experiments have shown that when the reaction is limited to the formation of C{sub 2} to C{sub 10} products, yields of aromatics can exceed 40% at temperatures of 1200{degrees}C. Preliminary experiments have shown that cooling the product and reacting gases as the reaction proceeds can significantly reduce or eliminate the formation of solid carbon and heavier (C{sub 10+}) materials. Much work remains to be done in optimizing the quenching process and this is one of the goals of this program. Means to lower the temperature of the reaction are being studied as this result in a more feasible commercial process due to savings realized in energy and material of construction costs. The use of free-radical generators and catalysts will be investigated as a means of lowering the reaction temperature thus allowing faster quenching. It is highly likely that such studies will lead to a successful direct methane to higher hydrocarbon process.

  4. Research Directions in Anthropological Pragmatics

    Directory of Open Access Journals (Sweden)

    Piotr P. Chruszczewski

    2011-08-01

    Full Text Available Anthropological linguistics, and by default also anthropological pragmatics, grew as sub-disciplines of both anthropology and linguistics. “The intellectual basis for anthropological linguistics in the United States derives from Boas ([1911] 1966, whose interests and concerns led to the anthropological view of language, which is that language is an integral part of culture (…” (Klein 2006: 296. Pragmatics enters the scene, telling the researcher how to analyse the aforementioned phenomena. Therefore, anthropological pragmatics would be responsible for equipping the researcher with tools, for it is language and language-oriented mechanisms of communication, the study of which provides a much clearer insight into cultural phenomena which often direct the use of language representing culture from both the synchronic and the diachronic point of view. “[O]ne approaches language from an anthropological view, which includes the uses of language and the uses of silence, as well as the cultural problems involved in silence and speech” (ibid..

  5. Direct Fast-Neutron Detection

    International Nuclear Information System (INIS)

    DC Stromswold; AJ Peurrung; RR Hansen; PL Reeder

    2000-01-01

    Direct fast-neutron detection is the detection of fast neutrons before they are moderated to thermal energy. We have investigated two approaches for using proton-recoil in plastic scintillators to detect fast neutrons and distinguish them from gamma-ray interactions. Both approaches use the difference in travel speed between neutrons and gamma rays as the basis for separating the types of events. In the first method, we examined the pulses generated during scattering in a plastic scintillator to see if they provide a means for distinguishing fast-neutron events from gamma-ray events. The slower speed of neutrons compared to gamma rays results in the production of broader pulses when neutrons scatter several times within a plastic scintillator. In contrast, gamma-ray interactions should produce narrow pulses, even if multiple scattering takes place, because the time between successive scattering is small. Experiments using a fast scintillator confirmed the presence of broader pulses from neutrons than from gamma rays. However, the difference in pulse widths between neutrons and gamma rays using the best commercially available scintillators was not sufficiently large to provide a practical means for distinguishing fast neutrons and gamma rays on a pulse-by-pulse basis. A faster scintillator is needed, and that scintillator might become available in the literature. Results of the pulse-width studies were presented in a previous report (peurrung et al. 1998), and they are only summarized here

  6. ANSTO - achievements and future directions

    International Nuclear Information System (INIS)

    Garnett, H. M.

    1997-01-01

    In the opening keynote address to the conference, Professor Helen Garnett, Executive Director of ANSTO, outlined the Organisation's main achievements and its future directions. In the ten years which have elapsed since its inception in 1987, ANSTO has evolved into a forward thinking, proactive nuclear science and technology Organisation. Its vision for the future is for nuclear science and technology to be accepted as benefiting all Australians and for ANSTO to be acknowledged as the premier nuclear science and technology organisation within the Asia Pacific Region. At the same time the organisation has continually reviewed and evaluated what it was doing and how it was doing. At the end of its first decade, it has enhanced the productivity from its research and development activities, received a positive evaluation on the impact that the application of this knowledge is having on the minerals and other industrial sectors, and focussed its research and development into a few areas where substantial teams of ANSTO staff, working cooperatively with staff from universities, other national organisations and industry, can have significant impact. ANSTO now has four parallel activities: the conduct of research and development, the provision of expert technical advice, the operation of national nuclear facilities and the commercial marketing of products and services. The recent announcement by Australian Government to replace HIFAR reactor with a leading medium flux reactor facility, will enable ANSTO to develop world class capability in selected areas of neutron science and to became an acknowledged regional centre, particular in cold neutron science

  7. ORIGINAL ARTICLES

    African Journals Online (AJOL)

    Recent developments have focused on vaginal microbicides, which have the advantage of ... population comprised a small community of women selling beers and sex to truck ... gonorrhoeae, and another was rolled onto a glass slide for direct.

  8. Cometary Defense with Directed Energy

    Science.gov (United States)

    Zhang, Q.; Lubin, P. M.; Hughes, G. B.

    2016-12-01

    Cometary impacts pose a long-term hazard to humans on Earth. Due to their comparative rarity, most planetary defense schemes neglect the comet threat, choosing instead to focus exclusively on mitigating asteroid impacts. Methods like kinetic impactors may be suitable for deflecting near-Earth asteroids (NEAs) and Jupiter-family comets (JFCs), both of which are characterized by low inclination orbits and short orbital periods which favor early detection—characteristics ideal for an interception mission. In contrast, Halley-type comets (HTCs) and long-period comets (LPCs) are often found in high inclination orbits rarely more than 2 yr prior to reaching Earth's orbit. Unless discovered and identified in a prior apparition—often centuries or millennia earlier, if ever—timely interception of a threatening HTC or LPC is improbable even with preparation, with missions demanding delta-v budgets often in excess of 30 km/s. Active comets, however, are already naturally perturbed from purely gravitational trajectories through solar-driven sublimation of volatiles. Further deflection may be achieved by supplementing the solar radiation with an artificial directed energy source such as by one or more laser arrays positioned on or near Earth. Simulations were developed with models derived from the known solar nongravitational perturbations of typical comets. Results suggest that a diffraction-limited 500 m array operating at 10 GW for 10 min/day may be sufficient to divert a typical active 500 m comet from an impact given 1 yr. A larger 1 km array operating at 100 GW for 100 s/day is similarly effective. Care must be taken to ensure the target remains intact throughout the deflection period due to comets' low compressive strength and resulting propensity for disintegration at high incident flux.

  9. Matlab Source Code for Species Transport through Nafion Membranes in Direct Ethanol, Direct Methanol, and Direct Glucose Fuel Cells

    OpenAIRE

    JH, Summerfield; MW, Manley

    2016-01-01

    A simple simulation of chemical species movement is presented. The species traverse a Nafion membrane in a fuel cell. Three cells are examined: direct methanol, direct ethanol, and direct glucose. The species are tracked using excess proton concentration, electric field strength, and voltage. The Matlab computer code is provided.

  10. Future directions of ecosystem science

    Science.gov (United States)

    Baron, Jill S.; Galvin, Kathleen A.

    1990-01-01

    , and global--have not replaced one another (Clark and Holling 1985). Instead, the effects are superimposed, creating what some perceive as impending global environmental crisis (Clark 1989, MacNeill 1989, WCED 1987). Public demands are developing for economic, political, social, and environmental efforts directed toward creating a state of global sustainability.

  11. Wave directional spectrum from array measurements

    Digital Repository Service at National Institute of Oceanography (India)

    Fernandes, A.A; Sarma, Y; Menon, H.B.

    Using the method of Esteva (1976, 1977), whcih assumes that at the frequency band the waves approach from just a single "mean" wave direction, wave direction has been consistently, accurately and unambiguously evaluated as a function of frequency...

  12. Towards host-directed therapies for tuberculosis.

    Science.gov (United States)

    Zumla, Alimuddin; Maeurer, Markus; Chakaya, Jeremiah; Hoelscher, Michael; Ntoumi, Francine; Rustomjee, Roxana; Vilaplana, Cristina; Yeboah-Manu, Dorothy; Rasolof, Voahangy; Munderi, Paula; Singh, Nalini; Aklillu, Eleni; Padayatchi, Nesri; Macete, Eusebio; Kapata, Nathan; Mulenga, Modest; Kibiki, Gibson; Mfinanga, Sayoki; Nyirenda, Thomas; Maboko, Leonard; Garcia-Basteiro, Alberto; Rakotosamimanana, Niaina; Bates, Matthew; Mwaba, Peter; Reither, Klaus; Gagneux, Sebastien; Edwards, Sarah; Mfinanga, Elirehema; Abdulla, Salim; Cardona, Pere-Joan; Russell, James B W; Gant, Vanya; Noursadeghi, Mahdad; Elkington, Paul; Bonnet, Maryline; Menendez, Clara; Dieye, Tandakha N; Diarra, Bassirou; Maiga, Almoustapha; Aseffa, Abraham; Parida, Shreemanta; Wejse, Christian; Petersen, Eskild; Kaleebu, Pontiano; Oliver, Matt; Craig, Gill; Corrah, Tumena; Tientcheu, Leopold; Antonio, Martin; Rao, Martin; McHugh, Timothy D; Sheikh, Aziz; Ippolito, Giuseppe; Ramjee, Gita; Kaufmann, Stefan H E; Churchyard, Gavin; Steyn, Andrie; Grobusch, Martin; Sanne, Ian; Martinson, Neil; Madansein, Rajhmun; Wilkinson, Robert J; Mayosi, Bongani; Schito, Marco; Wallis, Robert S

    2015-08-01

    The treatment of tuberculosis is based on combinations of drugs that directly target Mycobacterium tuberculosis. A new global initiative is now focusing on a complementary approach of developing adjunct host-directed therapies.

  13. Directional outlyingness for multivariate functional data

    KAUST Repository

    Dai, Wenlin; Genton, Marc G.

    2018-01-01

    The direction of outlyingness is crucial to describing the centrality of multivariate functional data. Motivated by this idea, classical depth is generalized to directional outlyingness for functional data. Theoretical properties of functional

  14. Direct Interval Forecasting of Wind Power

    DEFF Research Database (Denmark)

    Wan, Can; Xu, Zhao; Pinson, Pierre

    2013-01-01

    This letter proposes a novel approach to directly formulate the prediction intervals of wind power generation based on extreme learning machine and particle swarm optimization, where prediction intervals are generated through direct optimization of both the coverage probability and sharpness...

  15. Directional Collision Avoidance in Ad Hoc Networks

    National Research Council Canada - National Science Library

    Wang, Yu; Garcia-Luna-Aceves, J. J

    2004-01-01

    This paper analyzes the performance of directional collision avoidance schemes, in which antenna systems are used to direct the transmission and reception of control and data packets in channel access...

  16. Directional Wide-Angle Range Finder (DWARF)

    Data.gov (United States)

    National Aeronautics and Space Administration — The proposed innovation, the Directional Wide-Angle Range Finder (DWARF) is the creation of a laser range-finder with a wide field-of-view (FOV) and a directional...

  17. The spatial patterns of directional phenotypic selection

    KAUST Repository

    Siepielski, Adam M.; Gotanda, Kiyoko M.; Morrissey, Michael B.; Diamond, Sarah E.; DiBattista, Joseph; Carlson, Stephanie Marie

    2013-01-01

    the spatial patterns of selection, namely the extent of variation among populations in the strength and direction of selection. Here, we analyse a data set of spatially replicated studies of directional phenotypic selection from natural populations. The data

  18. 78 FR 72834 - Airworthiness Directives; SOCATA Airplanes

    Science.gov (United States)

    2013-12-04

    ... Airworthiness Directives; SOCATA Airplanes AGENCY: Federal Aviation Administration (FAA), Department of... airworthiness directive (AD) for SOCATA Model TBM 700 airplanes. This proposed AD results from mandatory... review this referenced service information at the FAA, Small Airplane Directorate, 901 Locust, Kansas...

  19. AIRTV: Broadband Direct to Aircraft

    Science.gov (United States)

    Sorbello, R.; Stone, R.; Bennett, S. B.; Bertenyi, E.

    2002-01-01

    Airlines have been continuously upgrading their wide-body, long-haul aircraft with IFE (in-flight entertainment) systems that can support from 12 to 24 channels of video entertainment as well as provide the infrastructure to enable in-seat delivery of email and internet services. This is a direct consequence of increased passenger demands for improved in-flight services along with the expectations that broadband delivery systems capable of providing live entertainment (news, sports, financial information, etc.) and high speed data delivery will soon be available. The recent events of Sept. 11 have slowed the airline's upgrade of their IFE systems, but have also highlighted the compelling need for broadband aeronautical delivery systems to include operational and safety information. Despite the impact of these events, it is estimated that by 2005 more than 3000 long haul aircraft (servicing approximately 1 billion passengers annually) will be fully equipped with modern IFE systems. Current aircraft data delivery systems, which use either Inmarsat or NATS, are lacking in bandwidth and consequently are unsuitable to satisfy passenger demands for broadband email/internet services or the airlines' burgeoning data requirements. Present live video delivery services are limited to regional coverage and are not readily expandable to global or multiregional service. Faced with a compelling market demand for high data transport to aircraft, AirTV has been developing a broadband delivery system that will meet both passengers' and airlines' needs. AirTV is a global content delivery system designed to provide a range of video programming and data services to commercial airlines. When AirTV is operational in 2004, it will provide a broadband connection directly to the aircraft, delivering live video entertainment, internet/email service and essential operational and safety data. The system has been designed to provide seamless global service to all airline routes except for those

  20. Hydrothermal industrialization: direct heat development. Final report

    Energy Technology Data Exchange (ETDEWEB)

    1982-05-01

    A description of hydrothermal resources suitable for direct applications, their associated temperatures, geographic distribution and developable capacity are given. An overview of the hydrothermal direct-heat development infrastructure is presented. Development activity is highlighted by examining known and planned geothermal direct-use applications. Underlying assumptions and results for three studies conducted to determine direct-use market penetration of geothermal energy are discussed.

  1. 31 CFR 357.26 - Direct Deposit.

    Science.gov (United States)

    2010-07-01

    ... 31 Money and Finance: Treasury 2 2010-07-01 2010-07-01 false Direct Deposit. 357.26 Section 357.26 Money and Finance: Treasury Regulations Relating to Money and Finance (Continued) FISCAL SERVICE... AND BILLS HELD IN LEGACY TREASURY DIRECT Legacy Treasury Direct Book-Entry Securities System (Legacy...

  2. Directed Forgetting of Recently Recalled Autobiographical Memories

    Science.gov (United States)

    Barnier, Amanda J.; Conway, Martin A.; Mayoh, Lyndel; Speyer, Joanne; Avizmil, Orit; Harris, Celia B.

    2007-01-01

    In 6 experiments, the authors investigated list-method directed forgetting of recently recalled autobiographical memories. Reliable directed forgetting effects were observed across all experiments. In 4 experiments, the authors examined the impact of memory valence on directed forgetting. The forget instruction impaired recall of negative,…

  3. 78 FR 53635 - Airworthiness Directives; Airbus Airplanes

    Science.gov (United States)

    2013-08-30

    ... Airworthiness Directives; Airbus Airplanes AGENCY: Federal Aviation Administration (FAA), DOT. ACTION: Final rule. SUMMARY: We are adopting a new airworthiness directive (AD) for certain Airbus Model A330-200 and... Sec. 39.13 by adding the following new airworthiness directive (AD): 2013-17-03 Airbus: Amendment 39...

  4. Object Detection: Current and Future Directions

    Directory of Open Access Journals (Sweden)

    Rodrigo eVerschae

    2015-11-01

    Full Text Available Object detection is a key ability required by most computer and robot vision systems. The latest research on this area has been making great progress in many directions. In the current manuscript we give an overview of past research on object detection, outline the current main research directions, and discuss open problems and possible future directions.

  5. 19 CFR 351.509 - Direct taxes.

    Science.gov (United States)

    2010-04-01

    ... Duties INTERNATIONAL TRADE ADMINISTRATION, DEPARTMENT OF COMMERCE ANTIDUMPING AND COUNTERVAILING DUTIES Identification and Measurement of Countervailable Subsidies § 351.509 Direct taxes. (a) Benefit—(1) Exemption or... direct tax (e.g., an income tax), or a reduction in the base used to calculate a direct tax, a benefit...

  6. Potential Dimension Yields From Direct Processing

    Science.gov (United States)

    Wenjie Lin; D. Earl Kline; Philip A. Araman

    1994-01-01

    As the price of timber increases and environmental leigslation limits harvestable log volumes, the process of converting logs directly into dimension parts needs further exploration. Direct processing converts logs directly into rough green dimension parts without the intermediate steps of lumber manufacturing, grading, trading, shipping and drying. A major attraction...

  7. Empirical Evaluation of Directional-Dependence Tests

    Science.gov (United States)

    Thoemmes, Felix

    2015-01-01

    Testing of directional dependence is a method to infer causal direction that recently has attracted some attention. Previous examples by e.g. von Eye and DeShon (2012a) and extensive simulation studies by Pornprasertmanit and Little (2012) have demonstrated that under specific assumptions, directional-dependence tests can recover the true causal…

  8. Directe en indirecte werknemersparticipatie in Europa

    NARCIS (Netherlands)

    van Houten, Gijs; Akkerman, Agnes; Sluiter, Roderick; Jansen, Giedo; Vermeylen, Greet

    2016-01-01

    This study looks at different forms of direct and indirect employee participation in the EU. The research questions are: (1) which forms of direct and indirect employee participation can we distinguish?; (2) to what extent do forms of direct and indirect employee participation coincide within

  9. 14 CFR 212.7 - Direct sales.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 4 2010-01-01 2010-01-01 false Direct sales. 212.7 Section 212.7... REGULATIONS CHARTER RULES FOR U.S. AND FOREIGN DIRECT AIR CARRIERS § 212.7 Direct sales. (a) Certificated and foreign air carriers may sell or offer for sale, and operate, as principal, Public Charter flights under...

  10. Determining Directional Dependency in Causal Associations

    Science.gov (United States)

    Pornprasertmanit, Sunthud; Little, Todd D.

    2012-01-01

    Directional dependency is a method to determine the likely causal direction of effect between two variables. This article aims to critique and improve upon the use of directional dependency as a technique to infer causal associations. We comment on several issues raised by von Eye and DeShon (2012), including: encouraging the use of the signs of…

  11. The Direct Satellite Connection: Definitions and Prospects.

    Science.gov (United States)

    Wigand, Rolf T.

    1980-01-01

    Defines direct satellite broadcasting as the transmission of broadcast signals via high-powered satellites that permit direct reception of television or radio programs by means of small antennas. Outlines American, European, and Japanese plans for direct-to-home television reception and implications for the broadcasting industry. (JMF)

  12. Algorithm for counting large directed loops

    Energy Technology Data Exchange (ETDEWEB)

    Bianconi, Ginestra [Abdus Salam International Center for Theoretical Physics, Strada Costiera 11, 34014 Trieste (Italy); Gulbahce, Natali [Theoretical Division and Center for Nonlinear Studies, Los Alamos National Laboratory, NM 87545 (United States)

    2008-06-06

    We derive a Belief-Propagation algorithm for counting large loops in a directed network. We evaluate the distribution of the number of small loops in a directed random network with given degree sequence. We apply the algorithm to a few characteristic directed networks of various network sizes and loop structures and compare the algorithm with exhaustive counting results when possible. The algorithm is adequate in estimating loop counts for large directed networks and can be used to compare the loop structure of directed networks and their randomized counterparts.

  13. Direct convertor based upon space charge effects

    International Nuclear Information System (INIS)

    Gitomer, S.J.

    1977-01-01

    A device capable of converting directly the kinetic energy of charged particles into electrical energy is considered. The device differs from earlier ones (such as Post's periodic focus electrostatic direct convertor) in that it makes use of the space charge repulsion in a high density charged particle beam. The beam is directed into a monotonic decelerating electrostatic field of a several-stage planar-finned structure. The collector fins coincide with vacuum equipotential surfaces. Space charge blowup of the beam directs particles onto various collector fins. The energy efficiency of a 4-stage device has been determined using a numberical simulation approach. We find that efficiencies approaching 75 percent are possible. An approximate scaling law is derived for the space charge based direct converter and a comparison is made to the periodic focus direct convertor. We find the space charge based direct convertor to be superior to a number of ways

  14. Verbal directionality and argument alternation in Dinka

    DEFF Research Database (Denmark)

    Andersen, Torben

    2012-01-01

    The derivational morphology of verbs in Dinka includes a distinction between direction towards the deictic center (centripetal) and a direction not towards the deictic center (centrifugal). A goal adverbial requires a directional verb, and an object of such a verb refers to something that moves t...... of a simple verb may correspond to, respectively, a goal adverbial and an object of the directional verb. Another type of argument alternation results from the possibility of expressing a goal as an object of an applicative verb with an intransitive or transitive base.......(wards) an explicit or implicit goal. The object of a directional verb may play another role in the event described by the sentence than the object of the corresponding simple (and non-directional) verb. This gives rise to so-called argument alternation, in that, for instance, an object and an instrumental adverbial...

  15. A wide-range direction neutron spectrometer

    International Nuclear Information System (INIS)

    Luszik-Bhadra, M.; D'Errico, F.; Hecker, O.; Matzke, M.

    2002-01-01

    A new device is presented which has been developed for measuring the energy and direction of distribution of neutron fluence in fields of broad energy spectra (thermal to 100 MeV) and with a high background of photon, electron and muon radiation. The device was tested in reference fields with different energy and direction distributions of neutron fluence. The direction-integrated fluence spectra agree fairly well with reference spectra. In all cases, the ambient and personal dose equivalent values calculated from measured direction-differential spectra are within 35% of the reference values. Independent measurements of the directional dose equivalent were performed with a directional dose equivalent monitor based on superheated drop detectors

  16. Supplementary income. Direct selling in Germany

    International Nuclear Information System (INIS)

    Roesner, Sven

    2014-01-01

    This document treats, first, of the evolution of the German support mechanisms to renewable energy sources. Then, it presents the legal framework of direct electricity selling (goal, evolution, facilities in concern and eligibility criteria). Next, the operation of direct selling since August 2014 in Germany is presented (producers eligibility, over- and under-production, reference values, income, tariffs). Finally, the perspectives and conditions of direct selling success are summarized in the conclusion

  17. Direct Marketing Communication at SEAL Communication Company

    OpenAIRE

    Wachtler, Kamilla Dóra

    2010-01-01

    The appearance of the Internet and new, rapidly changing emerging online technologies have led to some fundamental changes in marketing -- especially direct marketing. Besides the growing popularity of the Internet, the appearance of databases and one-to-one marketing are challenging traditional marketing methods. This thesis attempts to illustrate how direct marketing techniques can be implemented in an IT company. It starts with an overview of the concepts of direct marketing and its techni...

  18. Spatial roles and verbal directionality in Dinka

    DEFF Research Database (Denmark)

    Andersen, Torben

    2012-01-01

    This article deals with the interaction between two subsystems of the grammar of Dinka, a Western Nilotic language: (i) the semantic role of a place adverbial as location, source or goal, and (ii) deictic directionality expressed in the verb. Some place adverbials do not encode the distinction be...... verb. In clauses with a single place adverbial, moreover, a source adverbial requires either a non-directional verb or a centripetal verb, and a location adverbial requires a non-directional verb....

  19. Navy Telemedicine: Current Research and Future Directions

    National Research Council Canada - National Science Library

    Reed, Cheryl

    2002-01-01

    .... This report reviews military and civilian models for evaluating telemedicine systems in order to determine future directions for Navy telemedicine research within the current funding environment...

  20. NASA directives master list and index

    Science.gov (United States)

    1995-01-01

    This handbook sets forth in two parts, Master List of Management Directives and Index to NASA Management Directives, the following information for the guidance of users of the NASA Management Directives System. Chapter 1 contains introductory information material on how to use this handbook. Chapter 2 is a complete master list of agencywide management directives, describing each directive by type, number, effective date, expiration date, title, and organization code of the office responsible for the directive. Chapter 3 includes a consolidated numerical list of all delegations of authority and a breakdown of such delegation by the office or center to which special authority is assigned. Chapter 4 sets forth a consolidated list of all NASA handbooks (NHB's) and important footnotes covering the control and ordering of such documents. Chapter 5 is a consolidated list of NASA management directives applicable to the Jet Propulsion Laboratory. Chapter 6 is a consolidated list of NASA regulations published in the Code of Federal Regulations. Chapter 7 is a consolidated list of NASA regulations published in Title 14 of the Code of Federal Regulations. Complementary manuals to the NASA Management Directives System are described in Chapter 8. The second part contains an in depth alphabetical index to all NASA management directives other than handbooks, most of which are indexed by titles only.

  1. Regional impacts of abolishing direct payments

    DEFF Research Database (Denmark)

    Uthes, Sandra; Priorr, Annette; Zander, Peter

    2011-01-01

    The direct payment system of the Common Agricultural Policy (CAP) provides income transfers to European farmers. Recently, several countries including England and Sweden have advocated the elimination of direct payments after 2013. The extent to which an elimination of direct payments would affect...... with different production orientations and land management types was modeled under the presence and absence of direct payments using a combination of agent-based and bio-economic modeling. We found that the initial characteristics of the regions, such as the historical farm structure and regional site conditions...

  2. From Nonradiating Sources to Directionally Invisible Objects

    Science.gov (United States)

    Hurwitz, Elisa

    The goal of this dissertation is to extend the understanding of invisible objects, in particular nonradiating sources and directional nonscattering scatterers. First, variations of null-field nonradiating sources are derived from Maxwell's equations. Next, it is shown how to design a nonscattering scatterer by applying the boundary conditions for nonradiating sources to the scalar wave equation, referred to here as the "field cloak method". This technique is used to demonstrate directionally invisible scatterers for an incident field with one direction of incidence, and the influence of symmetry on the directionality is explored. This technique, when applied to the scalar wave equation, is extended to show that a directionally invisible object may be invisible for multiple directions of incidence simultaneously. This opens the door to the creation of optically switchable, directionally invisible objects which could be implemented in couplers and other novel optical devices. Next, a version of the "field cloak method" is extended to the Maxwell's electro-magnetic vector equations, allowing more flexibility in the variety of directionally invisible objects that can be designed. This thesis concludes with examples of such objects and future applications.

  3. On the Strong Direct Summand Conjecture

    Science.gov (United States)

    McCullough, Jason

    2009-01-01

    In this thesis, our aim is the study the Vanishing of Maps of Tor Conjecture of Hochster and Huneke. We mainly focus on an equivalent characterization called the Strong Direct Summand Conjecture, due to N. Ranganathan. Our results are separated into three chapters. In Chapter 3, we prove special cases of the Strong Direct Summand Conjecture in…

  4. An analysis of multislot directional coupler

    International Nuclear Information System (INIS)

    Arai, Hiroyuki; Goto, Naohisa; Yamamoto, Takumi.

    1986-03-01

    This paper presents an analysis of multislot directional coupler for monitoring the gyrotron output. We solved the boundary value problem of the directional coupler to investigate the detailed effect of finite thickness slot and mutual coupling between slots. Numerical data of coupler design is presented for non-resonant a pair slot, and mode sensitivity in overmoded waveguide is also evaluated. (author)

  5. 76 FR 69168 - Airworthiness Directives; Airbus Airplanes

    Science.gov (United States)

    2011-11-08

    ...-1225; Directorate Identifier 2010-NM-269-AD] RIN 2120-AA64 Airworthiness Directives; Airbus Airplanes...: We propose to adopt a new airworthiness directive (AD) for certain Airbus Model A300 B4-2C, B4-103..., contact Airbus SAS-EAW (Airworthiness Office), 1 Rond Point Maurice Bellonte, 31707 Blagnac Cedex, France...

  6. 77 FR 66760 - Airworthiness Directives; Airbus Airplanes

    Science.gov (United States)

    2012-11-07

    ...-1162; Directorate Identifier 2012-NM-002-AD] RIN 2120-AA64 Airworthiness Directives; Airbus Airplanes...: We propose to adopt a new airworthiness directive (AD) for all Airbus Model A330-200 Freighter, A330... information identified in this proposed AD, contact Airbus SAS--Airworthiness Office--EAL, 1 Rond Point...

  7. 78 FR 39190 - Airworthiness Directives; Airbus Airplanes

    Science.gov (United States)

    2013-07-01

    ...-0543; Directorate Identifier 2012-NM-202-AD] RIN 2120-AA64 Airworthiness Directives; Airbus Airplanes...: We propose to adopt a new airworthiness directive (AD) for all Airbus Model A318, A319, A320, and... Friday, except Federal holidays. For service information identified in this proposed AD, contact Airbus...

  8. 77 FR 37829 - Airworthiness Directives; Airbus Airplanes

    Science.gov (United States)

    2012-06-25

    ...-0671; Directorate Identifier 2011-NM-096-AD] RIN 2120-AA64 Airworthiness Directives; Airbus Airplanes...: We propose to supersede an existing airworthiness directive (AD) that applies to certain Airbus Model... this proposed AD, contact Airbus SAS--Airworthiness Office--EAL, 1 Rond Point Maurice Bellonte, 31707...

  9. 78 FR 60798 - Airworthiness Directives; Airbus Airplanes

    Science.gov (United States)

    2013-10-02

    ...-0363; Directorate Identifier 2013-NM-031-AD] RIN 2120-AA64 Airworthiness Directives; Airbus Airplanes... directive (AD) for all Airbus Model A330-200, -300 and -200 Freighter series airplanes, and Model A340-200... information identified in this proposed AD, contact Airbus SAS--Airworthiness Office--EAL, 1 Rond Point...

  10. 77 FR 73340 - Airworthiness Directives; Airbus Airplanes

    Science.gov (United States)

    2012-12-10

    ... Airworthiness Directives; Airbus Airplanes AGENCY: Federal Aviation Administration (FAA), DOT. ACTION... earlier proposed airworthiness directive (AD) for all Airbus Model A318, A319, A320, and A321 series..., contact Airbus, Airworthiness Office--EAS, 1 Rond Point Maurice Bellonte, 31707 Blagnac Cedex, France...

  11. 78 FR 23105 - Airworthiness Directives; Airbus Airplanes

    Science.gov (United States)

    2013-04-18

    ... Directives; Airbus Airplanes AGENCY: Federal Aviation Administration (FAA), Department of Transportation (DOT). ACTION: Final rule. SUMMARY: We are adopting a new airworthiness directive (AD) for certain Airbus Model... Agency] has received a report via Airbus and Messier-Bugatti-Dowty Ltd, from a Maintenance repair...

  12. 78 FR 29261 - Airworthiness Directives; Airbus Airplanes

    Science.gov (United States)

    2013-05-20

    ...-0424; Directorate Identifier 2013-NM-014-AD] RIN 2120-AA64 Airworthiness Directives; Airbus Airplanes...: We propose to adopt a new airworthiness directive (AD) for all Airbus Model A330-200 Freighter, A330... this proposed AD, contact Airbus SAS, Airworthiness Office--EAL, 1 Rond Point Maurice Bellonte, 31707...

  13. 77 FR 11793 - Airworthiness Directives; Airbus Airplanes

    Science.gov (United States)

    2012-02-28

    ...-0185; Directorate Identifier 2011-NM-001-AD] RIN 2120-AA64 Airworthiness Directives; Airbus Airplanes...: We propose to adopt a new airworthiness directive (AD) for certain Airbus Model A300 B4-103, B4-203... Friday, except Federal holidays. For service information identified in this proposed AD, contact Airbus...

  14. 77 FR 15636 - Airworthiness Directives; Airbus Airplanes

    Science.gov (United States)

    2012-03-16

    ... Airworthiness Directives; Airbus Airplanes AGENCY: Federal Aviation Administration (FAA), DOT. ACTION: Notice of proposed rulemaking (NPRM). SUMMARY: We propose to adopt a new airworthiness directive (AD) for all Airbus... identified in this proposed AD, contact Airbus, Airworthiness Office--EAS, 1 Rond Point Maurice Bellonte...

  15. 77 FR 60325 - Airworthiness Directives; Airbus Airplanes

    Science.gov (United States)

    2012-10-03

    ...-1253; Directorate Identifier 2011-NM-079-AD] RIN 2120-AA64 Airworthiness Directives; Airbus Airplanes... directive (AD) that would supersede an existing AD for certain Airbus Model A318, A319, A320, and A321... Friday, except Federal holidays. For service information identified in this proposed AD, contact Airbus...

  16. 78 FR 59295 - Airworthiness Directives; Airbus Airplanes

    Science.gov (United States)

    2013-09-26

    ...-0829; Directorate Identifier 2013-NM-085-AD] RIN 2120-AA64 Airworthiness Directives; Airbus Airplanes...: We propose to supersede airworthiness directive (AD) 2010-23- 12, which applies to certain Airbus... through Friday, except Federal holidays. For Airbus service information identified in this proposed AD...

  17. 78 FR 70003 - Airworthiness Directives; Airbus Airplanes

    Science.gov (United States)

    2013-11-22

    ... Airworthiness Directives; Airbus Airplanes AGENCY: Federal Aviation Administration (FAA), DOT. ACTION: Notice of proposed rulemaking (NPRM). SUMMARY: We propose to adopt a new airworthiness directive (AD) for all Airbus Model A300 series airplanes; Airbus Model A300 B4-600, B4-600R, and F4-600R series airplanes, and Model...

  18. 78 FR 18925 - Airworthiness Directives; Airbus Airplanes

    Science.gov (United States)

    2013-03-28

    ...-0212; Directorate Identifier 2012-NM-116-AD] RIN 2120-AA64 Airworthiness Directives; Airbus Airplanes...: We propose to adopt a new airworthiness directive (AD) for all Airbus Model A330-223F, -223, -321...., Monday through Friday, except Federal holidays. For Airbus service information identified in this...

  19. 77 FR 66762 - Airworthiness Directives; Airbus Airplanes

    Science.gov (United States)

    2012-11-07

    ...-1159; Directorate Identifier 2012-NM-028-AD] RIN 2120-AA64 Airworthiness Directives; Airbus Airplanes...: We propose to adopt a new airworthiness directive (AD) for certain Airbus Model A310-203, -204, -222... information identified in this proposed AD, contact Airbus SAS--EAW (Airworthiness Office), 1 Rond Point...

  20. 76 FR 62673 - Airworthiness Directives; Airbus Airplanes

    Science.gov (United States)

    2011-10-11

    ...-1066; Directorate Identifier 2011-NM-050-AD] RIN 2120-AA64 Airworthiness Directives; Airbus Airplanes...: We propose to adopt a new airworthiness directive (AD), for certain Airbus Model A300 B2-1C, B2K-3C... Friday, except Federal holidays. For service information identified in this proposed AD, contact Airbus...

  1. 77 FR 49386 - Airworthiness Directives; Airbus Airplanes

    Science.gov (United States)

    2012-08-16

    ... Airworthiness Directives; Airbus Airplanes AGENCY: Federal Aviation Administration (FAA), DOT. ACTION: Notice of proposed rulemaking (NPRM). SUMMARY: We propose to adopt a new airworthiness directive (AD) for all Airbus..., except Federal holidays. For Airbus service information identified in this proposed AD, contact Airbus...

  2. 76 FR 72350 - Airworthiness Directives; Airbus Airplanes

    Science.gov (United States)

    2011-11-23

    ...-1253; Directorate Identifier 2011-NM-079-AD] RIN 2120-AA64 Airworthiness Directives; Airbus Airplanes...: We propose to adopt a new airworthiness directive (AD) for certain Airbus Model A319, A320, and A321... Friday, except Federal holidays. For service information identified in this proposed AD, contact Airbus...

  3. 78 FR 51117 - Airworthiness Directives; Airbus Airplanes

    Science.gov (United States)

    2013-08-20

    ...-0698; Directorate Identifier 2012-NM-136-AD] RIN 2120-AA64 Airworthiness Directives; Airbus Airplanes...: We propose to supersede airworthiness directive (AD) 2006-06- 14, that applies to certain Airbus... information identified in this proposed AD, contact Airbus, Airworthiness Office--EAS, 1 Rond Point Maurice...

  4. 76 FR 68671 - Airworthiness Directives; Airbus Airplanes

    Science.gov (United States)

    2011-11-07

    ...-1170; Directorate Identifier 2010-NM-264-AD] RIN 2120-AA64 Airworthiness Directives; Airbus Airplanes...: We propose to adopt a new airworthiness directive (AD) for all Airbus Model A300 B4-600, B4-600R, and... Friday, except Federal holidays. For Airbus service information identified in this proposed AD, contact...

  5. 76 FR 78524 - Airworthiness Directives; Airbus Airplanes

    Science.gov (United States)

    2011-12-19

    ... Airworthiness Directives; Airbus Airplanes AGENCY: Federal Aviation Administration (FAA), Department of Transportation (DOT). ACTION: Final rule. SUMMARY: We are adopting a new airworthiness directive (AD) for Airbus... an aeroplane from the Airbus production line, a fault message was triggered on FDU1 [fire detection...

  6. 78 FR 46306 - Airworthiness Directives; Airbus Airplanes

    Science.gov (United States)

    2013-07-31

    ...-0632; Directorate Identifier 2013-NM-045-AD] RIN 2120-AA64 Airworthiness Directives; Airbus Airplanes...: We propose to adopt a new airworthiness directive (AD) for all Airbus Model A330-200 and -300 series... identified in this proposed AD, contact Airbus SAS, Airworthiness Office--EAL, 1 Rond Point Maurice Bellonte...

  7. 78 FR 25902 - Airworthiness Directives; Airbus Airplanes

    Science.gov (United States)

    2013-05-03

    ...-0363; Directorate Identifier 2013-NM-031-AD] RIN 2120-AA64 Airworthiness Directives; Airbus Airplanes...: We propose to adopt a new airworthiness directive (AD) for all Airbus Model A330-200, -300 and -200... Friday, except Federal holidays. For service information identified in this proposed AD, contact Airbus...

  8. 78 FR 79292 - Airworthiness Directives; Airbus Airplanes

    Science.gov (United States)

    2013-12-30

    ... Airworthiness Directives; Airbus Airplanes AGENCY: Federal Aviation Administration (FAA), Department of... directive (AD) 2011-24-09 which applied to certain Airbus Model A340-200 and A340-300 series airplanes. AD... AD, contact Airbus SAS-- Airworthiness Office--EAL, 1 Rond Point Maurice Bellonte, 31707 Blagnac...

  9. 77 FR 15644 - Airworthiness Directives; Airbus Airplanes

    Science.gov (United States)

    2012-03-16

    ...-0192; Directorate Identifier 2011-NM-225-AD] RIN 2120-AA64 Airworthiness Directives; Airbus Airplanes...: We propose to adopt a new airworthiness directive (AD) for certain Airbus Model A330-200 and -200... information identified in this proposed AD, contact Airbus SAS--Airworthiness Office--EAL, 1 Rond Point...

  10. 77 FR 51729 - Airworthiness Directives; Airbus Airplanes

    Science.gov (United States)

    2012-08-27

    ...-0810; Directorate Identifier 2011-NM-195-AD] RIN 2120-AA64 Airworthiness Directives; Airbus Airplanes...: We propose to adopt a new airworthiness directive (AD) for certain Airbus Model A330-200, A330-300... identified in this proposed AD, contact Airbus SAS--Airworthiness Office--EAL, 1 Rond Point Maurice Bellonte...

  11. 78 FR 79333 - Airworthiness Directives; Airbus Airplanes

    Science.gov (United States)

    2013-12-30

    ...-1066; Directorate Identifier 2013-NM-021-AD] RIN 2120-AA64 Airworthiness Directives; Airbus Airplanes...: We propose to supersede airworthiness directive (AD) 2000-12- 12, for certain Airbus Model A300, A300... this proposed AD, contact Airbus SAS, Airworthiness Office--EAW, 1 Rond Point Maurice Bellonte, 31707...

  12. 78 FR 32345 - Airworthiness Directives; Airbus Airplanes

    Science.gov (United States)

    2013-05-30

    ... Directives; Airbus Airplanes AGENCY: Federal Aviation Administration (FAA), Department of Transportation (DOT). ACTION: Final rule. SUMMARY: We are adopting a new airworthiness directive (AD) for all Airbus Model A300... FedEx requested that copies of Airbus Service Bulletin A300-53- 6170, dated May 16, 2011, be provided...

  13. 78 FR 1723 - Airworthiness Directives; Airbus Airplanes

    Science.gov (United States)

    2013-01-09

    ... Airworthiness Directives; Airbus Airplanes AGENCY: Federal Aviation Administration (FAA), DOT. ACTION: Final rule; request for comments. SUMMARY: We are adopting a new airworthiness directive (AD) for all Airbus... Friday, except Federal holidays. For service information identified in this AD, contact Airbus...

  14. 78 FR 29666 - Airworthiness Directives; Airbus Airplanes

    Science.gov (United States)

    2013-05-21

    ...-0422; Directorate Identifier 2012-NM-097-AD] RIN 2120-AA64 Airworthiness Directives; Airbus Airplanes...: We propose to adopt a new airworthiness directive (AD) for certain Airbus Model A330-200 and -300... information identified in this proposed AD, contact Airbus SAS--Airworthiness Office--EAL, 1 Rond Point...

  15. 78 FR 64156 - Airworthiness Directives; Airbus Airplanes

    Science.gov (United States)

    2013-10-28

    ... Airworthiness Directives; Airbus Airplanes AGENCY: Federal Aviation Administration (FAA), Department of... directive (AD) for all Airbus Model A340-211 -212, -213, -311, -312, -313, -541, and -642 airplanes. This AD... information identified in this AD, contact Airbus SAS, Airworthiness Office--EAL, 1 Rond Point Maurice...

  16. 77 FR 26996 - Airworthiness Directives; Airbus Airplanes

    Science.gov (United States)

    2012-05-08

    ...-0427; Directorate Identifier 2011-NM-202-AD] RIN 2120-AA64 Airworthiness Directives; Airbus Airplanes...: We propose to adopt a new airworthiness directive (AD) for certain Airbus Model A320-214 and-232... Friday, except Federal holidays. For service information identified in this proposed AD, contact Airbus...

  17. 77 FR 7523 - Airworthiness Directives; Airbus Airplanes

    Science.gov (United States)

    2012-02-13

    ... Airworthiness Directives; Airbus Airplanes AGENCY: Federal Aviation Administration (FAA), Department of... directive (AD) for all Airbus Model A340-600 series airplanes. This AD requires modifying the fire.... Relevant Service Information Airbus has issued Mandatory Service Bulletin A340-26-5020, including Appendix...

  18. 78 FR 37498 - Airworthiness Directives; Airbus Airplanes

    Science.gov (United States)

    2013-06-21

    ...-0463; Directorate Identifier 2012-NM-165-AD] RIN 2120-AA64 Airworthiness Directives; Airbus Airplanes...: We propose to adopt a new airworthiness directive (AD) for certain Airbus Model A330-200, -200... holidays. For service information identified in this proposed AD, contact Airbus SAS--Airworthiness Office...

  19. 77 FR 19067 - Airworthiness Directives; Airbus Airplanes

    Science.gov (United States)

    2012-03-30

    ... Airworthiness Directives; Airbus Airplanes AGENCY: Federal Aviation Administration (FAA), Department of... directive (AD) for certain Airbus Model A321-131, -211, -212, and -231 airplanes. This AD requires a.... Relevant Service Information Airbus has issued Mandatory Service Bulletin A320-57-1120, Revision 01...

  20. 77 FR 12989 - Airworthiness Directives; Airbus Airplanes

    Science.gov (United States)

    2012-03-05

    ... Directives; Airbus Airplanes AGENCY: Federal Aviation Administration (FAA), Department of Transportation (DOT). ACTION: Final rule. SUMMARY: We are adopting a new airworthiness directive (AD) for certain Airbus Model.... Airbus carried out an investigation, demonstrating that the life limit of retraction brackets must be...