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Sample records for burgdorferi generates tlr2-dependent

  1. Activation of human monocytes by live Borrelia burgdorferi generates TLR2-dependent and -independent responses which include induction of IFN-beta.

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    Juan C Salazar

    2009-05-01

    Full Text Available It is widely believed that innate immune responses to Borrelia burgdorferi (Bb are primarily triggered by the spirochete's outer membrane lipoproteins signaling through cell surface TLR1/2. We recently challenged this notion by demonstrating that phagocytosis of live Bb by peripheral blood mononuclear cells (PBMCs elicited greater production of proinflammatory cytokines than did equivalent bacterial lysates. Using whole genome microarrays, we show herein that, compared to lysates, live spirochetes elicited a more intense and much broader transcriptional response involving genes associated with diverse cellular processes; among these were IFN-beta and a number of interferon-stimulated genes (ISGs, which are not known to result from TLR2 signaling. Using isolated monocytes, we demonstrated that cell activation signals elicited by live Bb result from cell surface interactions and uptake and degradation of organisms within phagosomes. As with PBCMs, live Bb induced markedly greater transcription and secretion of TNF-alpha, IL-6, IL-10 and IL-1beta in monocytes than did lysates. Secreted IL-18, which, like IL-1beta, also requires cleavage by activated caspase-1, was generated only in response to live Bb. Pro-inflammatory cytokine production by TLR2-deficient murine macrophages was only moderately diminished in response to live Bb but was drastically impaired against lysates; TLR2 deficiency had no significant effect on uptake and degradation of spirochetes. As with PBMCs, live Bb was a much more potent inducer of IFN-beta and ISGs in isolated monocytes than were lysates or a synthetic TLR2 agonist. Collectively, our results indicate that the enhanced innate immune responses of monocytes following phagocytosis of live Bb have both TLR2-dependent and -independent components and that the latter induce transcription of type I IFNs and ISGs.

  2. TLR2-Dependent Signaling for IL-15 Production Is Essential for the Homeostasis of Intestinal Intraepithelial Lymphocytes.

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    Qiu, Yuan; Pu, Aimin; Zheng, Hong; Liu, Minqiang; Chen, Weigang; Wang, Wensheng; Xiao, Weidong; Yang, Hua

    2016-01-01

    TLR2 signaling is related to colitis and involved in regulation of innate immunity in the intestinal tract, but the mechanisms remain unclear. The aim of this study is to investigate how TLR2 affects differentiation of intraepithelial lymphocytes (IELs) and regulates the susceptibility of colitis. IELs were isolated from the small intestine and colon of mice, respectively. The IEL phenotype, activation, and apoptosis were examined using flow cytometry and RT-PCR. IL-15 expression and IEL location were detected through immunohistochemistry. The experimental colitis was induced by administration of dextran sulfate sodium (DSS). We found that the numbers of CD8αα (+), CD8αβ (+), and TCRγδ (+) IELs were significantly decreased in TLR2-deficient mice and the residual IELs displayed reduced activation and proliferation and increased apoptosis, accompanied with impaired IL-15 expression by intestinal epithelial cells (IECs). Further study showed that TLR2 signaling maintained the expression of IL-15 in IEC via NF-κB activation. Moreover, TLR2-deficient mice were found to be more susceptible to DSS-induced colitis as shown by the increased severity of colitis. Our results demonstrate that IECs contribute to the maintenance of IELs at least partly via TLR2-dependent IL-15 production, which provides a clue that may link IECs to innate immune protection of the host via IELs. PMID:27563173

  3. Mechanisms generating long range correlation in nucleotide composition of the Borrelia Burgdorferi genome

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    Mackiewicz, P.; Gierlik, A.; Kowalczuk, M.; Szczepanik, D.; Dudek, M. R.; Cebrat, S.

    1999-12-01

    We have analysed protein coding and intergenic sequences in the Borrelia burgdorferi (the Lyme disease bacterium) genome using different kinds of DNA walks. Genes occupying the leading strand of DNA have significantly different nucleotide composition from genes occupying the lagging strand. Nucleotide compositional bias of the two DNA strands reflects the aminoacid composition of proteins. 96% of genes coding for ribosomal proteins lie on the leading DNA strand, which suggests that the positions of these as well as other genes are non-random. In the B. burgdorferi genome, the asymmetry in intergenic DNA sequences is lower than the asymmetry in the third positions in codons. All these characters of the B. burgdorferi genome suggest that both replication-associated mutational pressure and recombination mechanisms have established the specific structure of the genome and now any recombination leading to inversion of a gene in respect to the direction of replication is forbidden. This property of the genome allows us to assume that it is in a steady state, which enables us to fix some parameters for simulations of DNA evolution.

  4. Role of TLR2-dependent inflammation in metastatic progression

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    Kim, Sunhwa; Karin, Michael

    2011-01-01

    Inflammation is a part of the host defense system, which provides protection against invading pathogens. However, it has become increasingly clear that inflammation can be evoked by endogenous mediators through Toll-like receptors (TLRs) to enhance tumor progression and metastasis. Here, we discuss the roles of TLR-mediated inflammation in tumor progression and the mechanisms through which it accomplishes this pathogenic function.

  5. Borrelia burgdorferi Infections in the United States

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    Heymann, Warren R.; Ellis, Dana L.

    2012-01-01

    It is becoming increasingly evident that the clinical presentation of infection with Borrelia burgdorferi varies greatly between different parts of the world. A growing number of European and Asian isolates of Lyme borreliae, differing from the American strain of Borrelia burgdorferi, have been identified in several different disorders. In light of the increasing number of reports describing an association between various cutaneous disorders and infection with Borrelia burgdorferi and the con...

  6. Erythromycin Resistance in Borrelia burgdorferi

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    Terekhova, Darya; Sartakova, Marina L.; Wormser, Gary P.; Schwartz, Ira; Cabello, Felipe C.

    2002-01-01

    Susceptibility testing of laboratory strains and clinical isolates of Borrelia burgdorferi indicates that resistance to erythromycin is present in them. Evaluation of the MICs, minimal bactericidal concentrations, and kinetics of bacterial killing of erythromycin suggests that this resistance is increased by preexposure to the antibiotic, is dependent on inoculum size, and may be the result of selection of subpopulations of bacterial cells with increased resistance.

  7. Borrelia burgdorferi sensu lato in Ixodes ricinus ticks collected from migratory birds in Southern Norway

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    Skarpaas Tone

    2010-11-01

    Full Text Available Abstract Background Borrelia burgdorferi sensu lato (s.l. are the causative agent for Lyme borreliosis (LB, the most common tick-borne disease in the northern hemisphere. Birds are considered important in the global dispersal of ticks and tick-borne pathogens through their migration. The present study is the first description of B. burgdorferi prevalence and genotypes in Ixodes ricinus ticks feeding on birds during spring and autumn migration in Norway. Methods 6538 migratory birds were captured and examined for ticks at Lista Bird Observatory during the spring and the autumn migration in 2008. 822 immature I. ricinus ticks were collected from 215 infested birds. Ticks were investigated for infection with B. burgdorferi s.l. by real-time PCR amplification of the 16S rRNA gene, and B. burgdorferi s.l. were thereafter genotyped by melting curve analysis after real-time PCR amplification of the hbb gene, or by direct sequencing of the PCR amplicon generated from the rrs (16S-rrl (23S intergenetic spacer. Results B. burgdorferi s.l. were detected in 4.4% of the ticks. The most prevalent B. burgdorferi genospecies identified were B. garinii (77.8%, followed by B.valaisiana (11.1%, B. afzelii (8.3% and B. burgdorferi sensu stricto (2.8%. Conclusion Infection rate in ticks and genospecies composition were similar in spring and autumn migration, however, the prevalence of ticks on birds was higher during spring migration. The study supports the notion that birds are important in the dispersal of ticks, and that they may be partly responsible for the heterogeneous distribution of B. burgdorferi s.l. in Europe.

  8. Outer surface protein B is critical for Borrelia burgdorferi adherence and survival within Ixodes ticks.

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    Girish Neelakanta

    2007-03-01

    Full Text Available Survival of Borrelia burgdorferi in ticks and mammals is facilitated, at least in part, by the selective expression of lipoproteins. Outer surface protein (Osp A participates in spirochete adherence to the tick gut. As ospB is expressed on a bicistronic operon with ospA, we have now investigated the role of OspB by generating an OspB-deficient B. burgdorferi and examining its phenotype throughout the spirochete life cycle. Similar to wild-type isolates, the OspB-deficient B. burgdorferi were able to readily infect and persist in mice. OspB-deficient B. burgdorferi were capable of migrating to the feeding ticks but had an impaired ability to adhere to the tick gut and survive within the vector. Furthermore, the OspB-deficient B. burgdorferi bound poorly to tick gut extracts. The complementation of the OspB-deficient spirochete in trans, with a wild-type copy of ospB gene, restored its ability to bind tick gut. Taken together, these data suggest that OspB has an important role within Ixodes scapularis and that B. burgdorferi relies upon multiple genes to efficiently persist in ticks.

  9. Polyneuritis cranialis associated with Borrelia burgdorferi.

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    Schmutzhard, E; Stanek, G.; Pohl, P.

    1985-01-01

    Three patients with classical idiopathic polyneuritis cranialis, in whom no other aetiology could be detected, were examined serologically, by means of indirect immunofluorescence test, for antibodies (IgM and IgG) against Borrelia burgdorferi, the aetiologic agent of Lyme disease. In each case polyneuritis cranialis was caused by infection with Borrelia burgdorferi. Therapy with penicillin proved to be effective.

  10. Disparity in the natural cycles of Borrelia burgdorferi and the agent of human granulocytic ehrlichiosis.

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    Levin, M L; des Vignes, F.; Fish, D

    1999-01-01

    We studied the prevalence of Borrelia burgdorferi and the agent of human granulocytic ehrlichiosis (HGE) among questing nymphal and adult Ixodes scapularis ticks of the same generation and the infectivity of wild white-footed mice for ticks feeding on them. The prevalence of B. burgdorferi infection in host-seeking ticks increased less than twofold from nymphal (31% to 33%) to adult (52% to 56%) stage, and 52% of white-footed mice were infected. Prevalence of the agent of HGE increased 4.5- t...

  11. Enzyme activities of Borrelia burgdorferi sensu lato

    Czech Academy of Sciences Publication Activity Database

    Heroldová, M.; Němec, M.; Hubálek, Zdeněk; Halouzka, Jiří

    2001-01-01

    Roč. 46, č. 3 (2001), s. 179-182. ISSN 0015-5632 R&D Projects: GA ČR GA206/00/1204 Institutional research plan: CEZ:AV0Z6093917 Keywords : Borrelia burgdorferi * Lyme disease Subject RIV: EE - Microbiology, Virology Impact factor: 0.776, year: 2001

  12. Live Attenuated Borrelia burgdorferi Targeted Mutants in an Infectious Strain Background Protect Mice from Challenge Infection.

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    Hahn, Beth L; Padmore, Lavinia J; Ristow, Laura C; Curtis, Michael W; Coburn, Jenifer

    2016-08-01

    Borrelia burgdorferi, B. garinii, and B. afzelii are all agents of Lyme disease in different geographic locations. If left untreated, Lyme disease can cause significant and long-term morbidity, which may continue after appropriate antibiotic therapy has been administered and live bacteria are no longer detectable. The increasing incidence and geographic spread of Lyme disease are renewing interest in the vaccination of at-risk populations. We took the approach of vaccinating mice with two targeted mutant strains of B. burgdorferi that, unlike the parental strain, are avirulent in mice. Mice vaccinated with both strains were protected against a challenge with the parental strain and a heterologous B. burgdorferi strain by either needle inoculation or tick bite. In ticks, the homologous strain was eliminated but the heterologous strain was not, suggesting that the vaccines generated a response to antigens that are produced by the bacteria both early in mammalian infection and in the tick. Partial protection against B. garinii infection was also conferred. Protection was antibody mediated, and reactivity to a variety of proteins was observed. These experiments suggest that live attenuated B. burgdorferi strains may be informative regarding the identification of protective antigens produced by the bacteria and recognized by the mouse immune system in vivo Further work may illuminate new candidates that are effective and safe for the development of Lyme disease vaccines. PMID:27335385

  13. Lipid Exchange between Borrelia burgdorferi and Host Cells

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    Crowley, Jameson T; Toledo, Alvaro M; LaRocca, Timothy J.; Coleman, James L.; Erwin London; Benach, Jorge L.

    2013-01-01

    Author Summary Lyme disease, the most prevalent arthropod-borne disease in North America, is caused by the spirochete Borrelia burgdorferi. Cholesterol is a significant component of the B. burgdorferi membrane lipids, and is processed to make cholesterol-glycolipids. Our interest in the presence of cholesterol in B. burgdorferi recently led to the identification and characterization of eukaryotic-like lipid rafts in the spirochete. The presence of free cholesterol and cholesterol-glycolipids ...

  14. Borrelia burgdorferi tissue morphologies and imaging methodologies.

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    MacDonald, A B

    2013-08-01

    This manuscript offers an image presentation of diverse forms of Borrelia burgdorferi spirochetes which are not spiral or corkscrew shaped. Explanations are offered to justify the legitimacy of tissue forms of Borrelia which may confuse the inexperienced microscopic examiner and which may lead to the misdiagnosis of non-spiral forms as artifacts. Images from the author's personal collection of Borrelia burgdorferi images and a few select images of Borrelia burgdorferi from the peer-reviewed published literature are presented. A commentary justifying each of the image profiles and a survey of the imaging modalities utilized provides the reader with a frame of reference. Regularly spiraled Borrelia are rarely seen in solid tissues. A variety of straightened, undulating, and clipped-off profiles are demonstrated, and the structural basis for each image is explained. Tissue examination is a diagnostic tool and a quality control for judging the eradication or the persistence of borreliosis following attempts to eradicate the infection with antibiotic therapy. The presence or absence of chronic Lyme borreliosis may be objectively adjudicated by tissue examinations which demonstrate or which fail to show pathogenic microbes in patients who have received a full course of antibiotics. PMID:23479042

  15. Evaluation of a New Culture Medium for Borrelia burgdorferi

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    Marques, Adriana R.; Stock, Frida; Gill, Vee

    2000-01-01

    We evaluated the new MPM medium for the growth of Borrelia burgdorferi. All 18 blood samples from 17 patients with Lyme disease were negative. Growth studies showed that by day 4, most organisms in MPM were not viable. Our results reinforce the use of BSK medium as the primary choice for growing B. burgdorferi.

  16. Evaluation of in-vitro antibiotic susceptibility of different morphological forms of Borrelia burgdorferi

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    Sapi E

    2011-05-01

    Full Text Available Eva Sapi1, Navroop Kaur1, Samuel Anyanwu1, David F Luecke1, Akshita Datar1, Seema Patel1, Michael Rossi1, Raphael B Stricker21Lyme Disease Research Group, Department of Biology and Environmental Sciences, University of New Haven, New Haven, CT, USA; 2International Lyme and Associated Diseases Society, Bethesda, MD, USABackground: Lyme disease is a tick-borne illness caused by the spirochete Borrelia burgdorferi. Although antibiotic therapy is usually effective early in the disease, relapse may occur when administration of antibiotics is discontinued. Studies have suggested that resistance and recurrence of Lyme disease might be due to formation of different morphological forms of B. burgdorferi, namely round bodies (cysts and biofilm-like colonies. Better understanding of the effect of antibiotics on all morphological forms of B. burgdorferi is therefore crucial to provide effective therapy for Lyme disease.Methods: Three morphological forms of B. burgdorferi (spirochetes, round bodies, and biofilm-like colonies were generated using novel culture methods. Minimum inhibitory concentration and minimum bactericidal concentration of five antimicrobial agents (doxycycline, amoxicillin, tigecycline, metronidazole, and tinidazole against spirochetal forms of B. burgdorferi were evaluated using the standard published microdilution technique. The susceptibility of spirochetal and round body forms to the antibiotics was then tested using fluorescent microscopy (BacLight™ viability staining and dark field microscopy (direct cell counting, and these results were compared with the microdilution technique. Qualitative and quantitative effects of the antibiotics against biofilm-like colonies were assessed using fluorescent microscopy and dark field microscopy, respectively.Results: Doxycycline reduced spirochetal structures ~90% but increased the number of round body forms about twofold. Amoxicillin reduced spirochetal forms by ~85%–90% and round body

  17. Immunogenic integral membrane proteins of Borrelia burgdorferi are lipoproteins.

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    Brandt, M E; Riley, B S; Radolf, J D; Norgard, M V

    1990-04-01

    The pathogenic spirochete Borrelia burgdorferi contains a set of integral membrane proteins which were selectively extracted into the detergent phase upon solubilization of intact B. burgdorferi with the nonionic detergent Triton X-114. Virtually all of these hydrophobic proteins were recognized by antibodies in pooled sera from patients with chronic Lyme arthritis, demonstrating that proteins partitioning into the detergent phase of Triton X-114 encompass the major B. burgdorferi immunogens. Furthermore, most of these immunogenic proteins, including the previously characterized OspA and OspB membrane antigens, could be biosynthetically labeled when B. burgdorferi was incubated in vitro with [3H]palmitate. The OspA and OspB antigens were radioimmunoprecipitated from [3H]palmitate-labeled detergent-phase proteins with monoclonal antibodies, and [3H]palmitate was recovered unaltered from these proteins after sequential alkaline and acid hydrolyses. The combined results provide formal confirmation that the major B. burgdorferi immunogens extracted by Triton X-114 are lipoproteins. The demonstration that B. burgdorferi integral membrane antigens are lipoproteins may explain the basis of their immunogenicity and may help to improve our understanding of the surface topology of B. burgdorferi. PMID:2318538

  18. Whole-Genome Sequences of Thirteen Isolates of Borrelia burgdorferi

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    Schutzer S. E.; Dunn J.; Fraser-Liggett, C. M.; Casjens, S. R.; Qiu, W.-G.; Mongodin, E. F.; Luft, B. J.

    2011-02-01

    Borrelia burgdorferi is a causative agent of Lyme disease in North America and Eurasia. The first complete genome sequence of B. burgdorferi strain 31, available for more than a decade, has assisted research on the pathogenesis of Lyme disease. Because a single genome sequence is not sufficient to understand the relationship between genotypic and geographic variation and disease phenotype, we determined the whole-genome sequences of 13 additional B. burgdorferi isolates that span the range of natural variation. These sequences should allow improved understanding of pathogenesis and provide a foundation for novel detection, diagnosis, and prevention strategies.

  19. Infections with Ehrlichia canis and Borrelia burgdorferi in a dog

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    Tsachev Ilia

    2007-01-01

    Full Text Available A clinical case of Ehrlichia canis and Borrelia burgdorferi infections in a 5year-old male German Shepherd is described. Clinical, serological, necropsy and histopathological examinations supporting the diagnosis have been performed.

  20. Infections with Ehrlichia canis and Borrelia burgdorferi in a dog

    OpenAIRE

    Tsachev Ilia; Simeonov R.; Petrov Vladimir

    2007-01-01

    A clinical case of Ehrlichia canis and Borrelia burgdorferi infections in a 5year-old male German Shepherd is described. Clinical, serological, necropsy and histopathological examinations supporting the diagnosis have been performed.

  1. Isolation and characterization of Borrelia burgdorferi from Illinois Ixodes dammini.

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    Nelson, J A; Bouseman, J K; Kitron, U.; Callister, S M; Harrison, B; Bankowski, M. J; Peeples, M E; Newton, B.J.; Anderson, J F

    1991-01-01

    Ixodes dammini ticks from two northwestern Illinois sites were found to be infected with Borrelia burgdorferi at rates of 19 and 32%. B. burgdorferi isolates, one from each site, had protein and antigenic patterns similar to those of the B-31 strain. An indirect immunofluorescence method proved to be more sensitive than dark-field microscopy in detection of these spirochetes. A modified BSK medium containing rifampin was found to be more efficient for spirochete isolation than unsupplemented ...

  2. DNA Microarray Assessment of Putative Borrelia burgdorferi Lipoprotein Genes

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    Liang, Fang Ting; Nelson, F. Kenneth; Fikrig, Erol

    2002-01-01

    A DNA microarray containing fragments of 137 Borrelia burgdorferi B31 putative lipoprotein genes was used to examine Lyme disease spirochetes. DNA from B. burgdorferi sensu stricto B31, 297, and N40; Borrelia garinii IP90; and Borrelia afzelii P/Gau was fluorescently labeled and hybridized to the microarray, demonstrating the degree to which the individual putative lipoprotein genes were conserved among the genospecies. These data show that a DNA microarray can globally examine the genes enco...

  3. Proteome Analysis of Borrelia burgdorferi Response to Environmental Change

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    Angel, Thomas E.; Luft, Benjamin J.; Yang, Xiaohua; Nicora, Carrie D.; Camp, David G.; Jacobs, Jon M.; Smith, Richard D.

    2010-11-02

    We examined global changes in protein expression in the B31 strain of Borrelia burgdorferi, in response to two environmental cues (pH and temperature) chosen for their reported similarity to those encountered at different stages of the organism’s life cycle. Multidimensional nano-liquid chromatographic separations coupled with tandem mass spectrometry were used to examine the array of proteins (i.e., the proteome) of B. burgdorferi for different pH and temperature culture conditions. Changes in pH and temperature elicited in vitro adaptations of this spirochete known to cause Lyme disease and led to alterations in protein expression that are associated with increased microbial pathogenesis. We identified 1031 proteins that represent 59% of the annotated genome of B. burgdorferi and elucidated a core proteome of 414 proteins that were present in all environmental conditions investigated. Observed changes in protein abundances indicated varied replicon usage, as well as proteome functional distributions between the in vitro cell culture conditions. Surprisingly, the pH and temperature conditions that mimicked B. burgdorferi residing in the gut of a fed tick showed a marked reduction in protein diversity. Additionally, the results provide us with leading candidates for exploring how B. burgdorferi adapts to and is able to survive in a wide variety of environmental conditions and lay a foundation for planned in situ studies of B. burgdorferi isolated from the tick midgut and infected animals.

  4. Characterization of the RelBbu Regulon in Borrelia burgdorferi Reveals Modulation of Glycerol Metabolism by (pppGpp.

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    Julia V Bugrysheva

    Full Text Available The bacterial stringent response is triggered by deficiencies of available nutrients and other environmental stresses. It is mediated by 5'-triphosphate-guanosine-3'-diphosphate and 5'-diphosphate-guanosine-3'-diphosphate (collectively (pppGpp and generates global changes in gene expression and metabolism that enable bacteria to adapt to and survive these challenges. Borrelia burgdorferi encounters multiple stressors in its cycling between ticks and mammals that could trigger the stringent response. We have previously shown that the B. burgdorferi stringent response is mediated by a single enzyme, RelBbu, with both (pppGpp synthase and hydrolase activities, and that a B. burgdorferi 297 relBbu null deletion mutant was defective in adapting to stationary phase, incapable of down-regulating synthesis of rRNA and could not infect mice. We have now used this deletion mutant and microarray analysis to identify genes comprising the rel regulon in B. burgdorferi cultured at 34°C, and found that transcription of genes involved in glycerol metabolism is induced by relBbu. Culture of the wild type parental strain, the relBbu deletion mutant and its complemented derivative at 34°C and 25°C in media containing glucose or glycerol as principal carbon sources revealed a growth defect in the mutant, most evident at the lower temperature. Transcriptional analysis of the glp operon for glycerol uptake and metabolism in these three strains confirmed that relBbu was necessary and sufficient to increase transcription of this operon in the presence of glycerol at both temperatures. These results confirm and extend previous findings regarding the stringent response in B. burgdorferi. They also demonstrate that the stringent response regulates glycerol metabolism in this organism and is likely crucial for its optimal growth in ticks.

  5. Regulation of Expression of the Paralogous Mlp Family in Borrelia burgdorferi

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    Yang, Xiaofeng F.; Hübner, Anette; Popova, Taissia G.; Hagman, Kayla E.; Norgard, Michael V.

    2003-01-01

    The Mlp (multicopy lipoproteins) family is one of many paralogous protein families in Borrelia burgdorferi. To examine the extent to which the 10 members of the Mlp family in B. burgdorferi strain 297 might be differentially regulated, antibodies specific for each of the Mlps were developed and used to analyze the protein expression profiles of individual Mlps when B. burgdorferi replicated under various cultivation conditions. All of the Mlps were upregulated coordinately when B. burgdorferi...

  6. Characterization of biofilm formation by Borrelia burgdorferi in vitro.

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    Eva Sapi

    Full Text Available Borrelia burgdorferi, the causative agent of Lyme disease, has long been known to be capable of forming aggregates and colonies. It was recently demonstrated that Borrelia burgdorferi aggregate formation dramatically changes the in vitro response to hostile environments by this pathogen. In this study, we investigated the hypothesis that these aggregates are indeed biofilms, structures whose resistance to unfavorable conditions are well documented. We studied Borrelia burgdorferi for several known hallmark features of biofilm, including structural rearrangements in the aggregates, variations in development on various substrate matrices and secretion of a protective extracellular polymeric substance (EPS matrix using several modes of microscopic, cell and molecular biology techniques. The atomic force microscopic results provided evidence that multilevel rearrangements take place at different stages of aggregate development, producing a complex, continuously rearranging structure. Our results also demonstrated that Borrelia burgdorferi is capable of developing aggregates on different abiotic and biotic substrates, and is also capable of forming floating aggregates. Analyzing the extracellular substance of the aggregates for potential exopolysaccharides revealed the existence of both sulfated and non-sulfated/carboxylated substrates, predominately composed of an alginate with calcium and extracellular DNA present. In summary, we have found substantial evidence that Borrelia burgdorferi is capable of forming biofilm in vitro. Biofilm formation by Borrelia species might play an important role in their survival in diverse environmental conditions by providing refuge to individual cells.

  7. Distribution of Borrelia burgdorferi in host mice in Pennsylvania.

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    Lord, R D; Lord, V R; Humphreys, J. G.; McLean, R G

    1994-01-01

    Host mice (Peromyscus leucopus and Peromyscus maniculatus) were sampled throughout the state of Pennsylvania to determine the geographical and ecological distribution of the Lyme disease spirochete Borrelia burgdorferi. All 67 counties of the state were sampled. A total of 1,619 mice were captured from a total of 157 sites during the period 1990 to 1993 for an overall capture rate of 29.69%. A total of 112 (6.92%) isolations of B. burgdorferi were made. The distribution of isolations revealed...

  8. Trans-Atlantic exchanges have shaped the population structure of the Lyme disease agent Borrelia burgdorferi sensu stricto.

    Science.gov (United States)

    Castillo-Ramírez, S; Fingerle, V; Jungnick, S; Straubinger, R K; Krebs, S; Blum, H; Meinel, D M; Hofmann, H; Guertler, P; Sing, A; Margos, G

    2016-01-01

    The origin and population structure of Borrelia burgdorferi sensu stricto (s.s.), the agent of Lyme disease, remain obscure. This tick-transmitted bacterial species occurs in both North America and Europe. We sequenced 17 European isolates (representing the most frequently found sequence types in Europe) and compared these with 17 North American strains. We show that trans-Atlantic exchanges have occurred in the evolutionary history of this species and that a European origin of B. burgdorferi s.s. is marginally more likely than a USA origin. The data further suggest that some European human patients may have acquired their infection in North America. We found three distinct genetically differentiated groups: i) the outgroup species Borrelia bissettii, ii) two divergent strains from Europe, and iii) a group composed of strains from both the USA and Europe. Phylogenetic analysis indicated that different genotypes were likely to have been introduced several times into the same area. Our results demonstrate that irrespective of whether B. burgdorferi s.s. originated in Europe or the USA, later trans-Atlantic exchange(s) have occurred and have shaped the population structure of this genospecies. This study clearly shows the utility of next generation sequencing to obtain a better understanding of the phylogeography of this bacterial species. PMID:26955886

  9. Identification of superoxide dismutase activity in Borrelia burgdorferi.

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    Whitehouse, C. A.; Williams, L. R.; Austin, F E

    1997-01-01

    Infective and noninfective strains of Borrelia burgdorferi, along with Borrelia afzelii and Borrelia garinii, possessed a single iron-containing superoxide dismutase (SOD). None of the Lyme disease spirochetes tested possessed catalase or peroxidase activities. The borrelial SOD was not inducible by growth with increased oxygen concentrations and thus appeared to be produced constitutively.

  10. Lack of Serum Antibodies against Borrelia burgdorferi in Children with Autism

    OpenAIRE

    Burbelo, Peter D.; Swedo, Susan E.; Thurm, Audrey; Bayat, Ahmad; Levin, Andrew E.; Marques, Adriana; Iadarola, Michael J

    2013-01-01

    It has been proposed that Borrelia burgdorferi infection is present in ∼25% of children with autism spectrum disorders. In this study, antibodies against Borrelia burgdorferi were assessed in autistic (n = 104), developmentally delayed (n = 24), and healthy control (n = 55) children. No seropositivity against Borrelia burgdorferi was detected in the children with and without autism. There was no evidence of an association between Lyme disease and autism.

  11. Characterization of Borrelia burgdorferi isolates by restriction endonuclease analysis and DNA hybridization.

    OpenAIRE

    LeFebvre, R B; Perng, G C; Johnson, R C

    1989-01-01

    Genomes of several Borrelia burgdorferi isolates from North America and Europe were characterized by restriction endonuclease analysis and DNA hybridization using labeled B. burgdorferi whole-cell DNA (strain ATCC 35210). Several different restriction and homology patterns were observed among these isolates, indicating genotypic heterogeneity within this genus and species. It was concluded from this study that restriction endonuclease analysis of B. burgdorferi whole-cell DNA may be a reliabl...

  12. The critical role of the linear plasmid lp36 in the infectious cycle of Borrelia burgdorferi

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    Mollie W Jewett; Lawrence, Kevin; Bestor, Aaron C; Tilly, Kit; Grimm, Dorothee; Shaw, Pamela; VanRaden, Mark; Gherardini, Frank; Rosa, Patricia A.

    2007-01-01

    Borrelia burgdorferi, the aetiological agent of Lyme disease, follows a life cycle that involves passage between the tick vector and the mammalian host. To investigate the role of the 36 kb linear plasmid, lp36 (also designated the B. burgdorferi K plasmid), in the infectious cycle of B. burgdorferi, we examined a clone lacking this plasmid, but containing all other plasmids known to be required for infectivity. Our results indicated that lp36 was not required for spirochete survival in the t...

  13. Evidence for Host-Genotype Associations of Borrelia burgdorferi Sensu Stricto

    OpenAIRE

    Samir Mechai; Gabriele Margos; Feil, Edward J.; Nicole Barairo; L Robbin Lindsay; Pascal Michel; Nicholas H Ogden

    2016-01-01

    Different genotypes of the agent of Lyme disease in North America, Borrelia burgdorferi sensu stricto, show varying degrees of pathogenicity in humans. This variation in pathogenicity correlates with phylogeny and we have hypothesized that the different phylogenetic lineages in North America reflect adaptation to different host species. In this study, evidence for host species associations of B. burgdorferi genotypes was investigated using 41 B. burgdorferi-positive samples from five mammal s...

  14. Lipid exchange between Borrelia burgdorferi and host cells.

    Directory of Open Access Journals (Sweden)

    Jameson T Crowley

    2013-01-01

    Full Text Available Borrelia burgdorferi, the agent of Lyme disease, has cholesterol and cholesterol-glycolipids that are essential for bacterial fitness, are antigenic, and could be important in mediating interactions with cells of the eukaryotic host. We show that the spirochetes can acquire cholesterol from plasma membranes of epithelial cells. In addition, through fluorescent and confocal microscopy combined with biochemical approaches, we demonstrated that B. burgdorferi labeled with the fluorescent cholesterol analog BODIPY-cholesterol or (3H-labeled cholesterol transfer both cholesterol and cholesterol-glycolipids to HeLa cells. The transfer occurs through two different mechanisms, by direct contact between the bacteria and eukaryotic cell and/or through release of outer membrane vesicles. Thus, two-way lipid exchange between spirochetes and host cells can occur. This lipid exchange could be an important process that contributes to the pathogenesis of Lyme disease.

  15. Linear and Circular Plasmid Content in Borrelia burgdorferi Clinical Isolates

    OpenAIRE

    Iyer, Radha; Kalu, Ogori; Purser, Joye; Norris, Steven; Stevenson, Brian; Schwartz, Ira

    2003-01-01

    The genome of Borrelia burgdorferi, the etiologic agent of Lyme disease, is composed of a linear chromosome and more than 20 linear and circular plasmids. Typically, plasmid content analysis has been carried out by pulsed-field gel electrophoresis and confirmed by Southern hybridization. However, multiple plasmids of virtually identical sizes (e.g., lp28 and cp32) complicate the interpretation of such data. The present study was undertaken to investigate the complete plasmid complements of B....

  16. Minimal-Change Disease Secondary to Borrelia burgdorferi Infection

    OpenAIRE

    Ewa Kwiatkowska; Edyta Gołembiewska; Kazimierz Ciechanowski; Karolina Kędzierska

    2012-01-01

    Lyme borreliosis is a chronic illness caused by tick-transmitted spirochete Borrelia burgdorferi. Borreliosis can be extremely threatening if it is not diagnosed and treated in early stages. Kidneys are not typically involved in the disease. However, in infected dogs, Lyme nephritis is present in 5–10% of cases. It is associated with rapidly progressing renal failure. Histopathological examination shows mesangial proliferative glomerulonephritis with diffuse tubular necrosis, (Dambach et al. ...

  17. Pleomorphic forms of Borrelia burgdorferi induce distinct immune responses.

    Science.gov (United States)

    Meriläinen, Leena; Brander, Heini; Herranen, Anni; Schwarzbach, Armin; Gilbert, Leona

    2016-01-01

    Borrelia burgdorferi is the causative agent of tick-borne Lyme disease. As a response to environmental stress B. burgdorferi can change its morphology to a round body form. The role of B. burgdorferi pleomorphic forms in Lyme disease pathogenesis has long been debated and unclear. Here, we demonstrated that round bodies were processed differently in differentiated macrophages, consequently inducing distinct immune responses compared to spirochetes in vitro. Colocalization analysis indicated that the F-actin participates in internalization of both forms. However, round bodies end up less in macrophage lysosomes than spirochetes suggesting that there are differences in processing of these forms in phagocytic cells. Furthermore, round bodies stimulated distinct cytokine and chemokine production in these cells. We confirmed that spirochetes and round bodies present different protein profiles and antigenicity. In a Western blot analysis Lyme disease patients had more intense responses to round bodies when compared to spirochetes. These results suggest that round bodies have a role in Lyme disease pathogenesis. PMID:27139815

  18. Rodent species as natural reservoirs of Borrelia burgdorferi sensu lato in different habitats of Ixodes ricinus in The Netherlands

    NARCIS (Netherlands)

    Gassner, F.; Takken, W.; Plas, C.; Kastelein, P.; Hoetmer, A.J.; Holdinga, M.; Overbeek, van L.S.

    2013-01-01

    Rodents are natural reservoirs for human pathogenic spirochaetes of the Borrelia burgdorferi complex [B. burgdorferi sensu lato (s.l.)], and the pathogens are transmitted by Ixodes ricinus ticks to humans in The Netherlands. B. burgdorferi s.l. infection prevalence in questing ticks, rodents, and ti

  19. Ability to cause erythema migrans differs between Borrelia burgdorferi sensu lato isolates

    NARCIS (Netherlands)

    E. Tijsse-Klasen (Ellen); N. Pandak (Nenad); P. Hengeveld (Paul); K. Takumi (Katsuhisa); M.P.G. Koopmans D.V.M. (Marion); H. Sprong (Hein)

    2013-01-01

    textabstractBackground: Lyme borreliosis is a tick-borne disease caused by Borrelia burgdorferi sensu lato. The variety of characteristic and non-specific clinical manifestations is partially explained by its genetic diversity. We investigated the ability of B. burgdorferi sl isolates to cause eryth

  20. Evaluation of a quantitative fluorescence immunoassay (FIAX) for detection of serum antibody to Borrelia burgdorferi.

    OpenAIRE

    Pennell, D R; Wand, P J; Schell, R F

    1987-01-01

    A quantitative, indirect, fluorescence immunoassay (FIAX; Whittaker Bioproducts, Inc.) was compared with the conventional indirect fluorescent-antibody test for detection of serum antibody to Borrelia burgdorferi. FIAX correlated well with the indirect fluorescent-antibody test (r = 0.72). FIAX is a convenient and dependable means of measuring serum antibody to B. burgdorferi.

  1. Seroprevalence of Borrelia burgdorferi, Anaplasma phagocytophilum, Ehrlichia canis, and Dirofilaria immitis among dogs in Canada

    OpenAIRE

    Villeneuve, Alain; Goring, Jonas; Marcotte, Lynne; Overvelde, Sébastien

    2011-01-01

    The seropositivity of dogs to Borrelia burgdorferi, Anaplasma phagocytophilum, and Ehrlichia canis antibodies, and Dirofilaria immitis antigen was assessed in Canada. Borrelia burgdorferi had the highest seroprevalence, while that of Dirofilaria immitis has not changed significantly in the past 20 y. The risk for these vector-borne infectious agents in Canadian dogs is low but widespread with foci of higher prevalence.

  2. Simultaneous transmission of Borrelia burgdorferi and Babesia microti by individual nymphal Ixodes dammini ticks.

    OpenAIRE

    Piesman, J; Hicks, T.C.; Sinsky, R J; Obiri, G.

    1987-01-01

    Nymphal Ixodes dammini ticks, selected from a group of ticks in which 22 of 31 (71%) contained dual Borrelia burgdorferi and Babesia microti infections, simultaneously transmitted B. burgdorferi and B. microti to 4 of 7 (57%) hamsters exposed to individual ticks.

  3. The cyclic-di-GMP signaling pathway in the Lyme disease spirochete, Borrelia burgdorferi

    Directory of Open Access Journals (Sweden)

    Elizabeth A. Novak

    2014-05-01

    Full Text Available In nature, the Lyme disease spirochete Borrelia burgdorferi cycles between the unrelated environments of the Ixodes tick vector and mammalian host. In order to survive transmission between hosts, B. burgdorferi must be able to not only detect changes in its environment, but also rapidly and appropriately respond to these changes. One manner in which this obligate parasite regulates and adapts to its changing environment is through cyclic-di-GMP (c-di-GMP signaling. c-di-GMP has been shown to be instrumental in orchestrating the adaptation of B. burgdorferi to the tick environment. B. burgdorferi possesses only one set of c-di-GMP-metabolizing genes (one diguanylate cyclase and two distinct phosphodiesterases and one c-di-GMP-binding PilZ-domain protein designated as PlzA. While studies in the realm of c-di-GMP signaling in B. burgdorferi have exploded in the last few years, there are still many more questions than answers. Elucidation of the importance of c-di-GMP signaling to B. burgdorferi may lead to the identification of mechanisms that are critical for the survival of B. burgdorferi in the tick phase of the enzootic cycle as well as potentially delineate a role (if any c-di-GMP may play in the transmission and virulence of B. burgdorferi during the enzootic cycle, thereby enabling the development of effective drugs for the prevention and/or treatment of Lyme disease.

  4. Acetyl-Phosphate Is Not a Global Regulatory Bridge between Virulence and Central Metabolism in Borrelia burgdorferi.

    Science.gov (United States)

    Richards, Crystal L; Lawrence, Kevin A; Su, Hua; Yang, Youyun; Yang, X Frank; Dulebohn, Daniel P; Gherardini, Frank C

    2015-01-01

    In B. burgdorferi, the Rrp2-RpoN-RpoS signaling cascade is a distinctive system that coordinates the expression of virulence factors required for successful transition between its arthropod vector and mammalian hosts. Rrp2 (BB0763), an RpoN specific response regulator, is essential to activate this regulatory pathway. Previous investigations have attempted to identify the phosphate donor of Rrp2, including the cognate histidine kinase, Hk2 (BB0764), non-cognate histidine kinases such as Hk1, CheA1, and CheA2, and small molecular weight P-donors such as carbamoyl-phosphate and acetyl-phosphate (AcP). In a report by Xu et al., exogenous sodium acetate led to increased expression of RpoS and OspC and it was hypothesized this effect was due to increased levels of AcP via the enzyme AckA (BB0622). Genome analyses identified only one pathway that could generate AcP in B. burgdorferi: the acetate/mevalonate pathway that synthesizes the lipid, undecaprenyl phosphate (C55-P, lipid I), which is essential for cell wall biogenesis. To assess the role of AcP in Rrp2-dependent regulation of RpoS and OspC, we used a unique selection strategy to generate mutants that lacked ackA (bb0622: acetate to AcP) or pta (bb0589: AcP to acetyl-CoA). These mutants have an absolute requirement for mevalonate and demonstrate that ackA and pta are required for cell viability. When the ΔackA or Δpta mutant was exposed to conditions (i.e., increased temperature or cell density) that up-regulate the expression of RpoS and OspC, normal induction of those proteins was observed. In addition, adding 20mM acetate or 20mM benzoate to the growth media of B. burgdorferi strain B31 ΔackA induced the expression of RpoS and OspC. These data suggest that AcP (generated by AckA) is not directly involved in modulating the Rrp2-RpoN-RpoS regulatory pathway and that exogenous acetate or benzoate are triggering an acid stress response in B. burgdorferi. PMID:26681317

  5. Acetyl-Phosphate Is Not a Global Regulatory Bridge between Virulence and Central Metabolism in Borrelia burgdorferi.

    Directory of Open Access Journals (Sweden)

    Crystal L Richards

    Full Text Available In B. burgdorferi, the Rrp2-RpoN-RpoS signaling cascade is a distinctive system that coordinates the expression of virulence factors required for successful transition between its arthropod vector and mammalian hosts. Rrp2 (BB0763, an RpoN specific response regulator, is essential to activate this regulatory pathway. Previous investigations have attempted to identify the phosphate donor of Rrp2, including the cognate histidine kinase, Hk2 (BB0764, non-cognate histidine kinases such as Hk1, CheA1, and CheA2, and small molecular weight P-donors such as carbamoyl-phosphate and acetyl-phosphate (AcP. In a report by Xu et al., exogenous sodium acetate led to increased expression of RpoS and OspC and it was hypothesized this effect was due to increased levels of AcP via the enzyme AckA (BB0622. Genome analyses identified only one pathway that could generate AcP in B. burgdorferi: the acetate/mevalonate pathway that synthesizes the lipid, undecaprenyl phosphate (C55-P, lipid I, which is essential for cell wall biogenesis. To assess the role of AcP in Rrp2-dependent regulation of RpoS and OspC, we used a unique selection strategy to generate mutants that lacked ackA (bb0622: acetate to AcP or pta (bb0589: AcP to acetyl-CoA. These mutants have an absolute requirement for mevalonate and demonstrate that ackA and pta are required for cell viability. When the ΔackA or Δpta mutant was exposed to conditions (i.e., increased temperature or cell density that up-regulate the expression of RpoS and OspC, normal induction of those proteins was observed. In addition, adding 20mM acetate or 20mM benzoate to the growth media of B. burgdorferi strain B31 ΔackA induced the expression of RpoS and OspC. These data suggest that AcP (generated by AckA is not directly involved in modulating the Rrp2-RpoN-RpoS regulatory pathway and that exogenous acetate or benzoate are triggering an acid stress response in B. burgdorferi.

  6. Reservoir competence of Microtus pennsylvanicus (Rodentia: Cricetidae) for the Lyme disease spirochete, Borrelia burgdorferi

    Science.gov (United States)

    Markowski, D.; Ginsberg, H.S.; Hyland, K.E.; Hu, R.

    1998-01-01

    The reservoir competence of the meadow vole, Microtus pennsylvanicus Ord, for the Lyme disease spirochete, Borrelia burgdorferi Johnson, Schmid, Hyde, Steigerwalt & Brenner was established on Patience Island, RI. Meadow voles were collected from 5 locations throughout Rhode Island. At 4 of the field sites, M. pennsylvanicus represented only 4.0% (n = 141) of the animals captured. However, on Patience Island, M. pennsylvanicus was the sole small mammal collected (n = 48). Of the larval Ixodes scapularis Say obtained from the meadow voles on Patience Island, 62% (n = 78) was infected with B. burgdorferi. Meadow voles from all 5 locations were successfully infected with B. burgdorferi in the laboratory and were capable of passing the infection to xenodiagnostic I. scapularis larvae for 9 wk. We concluded that M. pennsylvanicus was physiologically capable of maintaining B. burgdorferi infection. However, in locations where Peromyscus leucopus (Rafinesque) is abundant, the role of M. pennsylvanicus as a primary reservoir for B. burgdorferi was reduced.

  7. Polymerase chain reaction in diagnosis of Borrelia burgdorferi infections and studies on taxonomic classification

    DEFF Research Database (Denmark)

    Lebech, Anne-Mette

    PCR assay for direct detection of B. burgdorferi DNA and to evaluate the diagnostic utility of PCR in clinical specimens from patients with Lyme borreliosis and (ii) to study the taxonomic classification of B. burgdorferi isolates and its implications for epidemiology and clinical presentation...... for PCR amplification and subsequent identification of B. burgdorferi specific sequences were established and used. For all assays the analytical sensitivity was a few genome copies using purified DNA as template. The efficacy of PCR was initially evaluated using tissue samples from experimentally...... infected gerbils in order to start with biological samples a priori known to contain B. burgdorferi. B. burgdorferi DNA was detectable in 88% of the specimens. Thus the diagnostic sensitivity of PCR was comparable to and even higher than in vitro culture. PCR was significantly more sensitive than a...

  8. Decreased Electroporation Efficiency in Borrelia burgdorferi Containing Linear Plasmids lp25 and lp56: Impact on Transformation of Infectious B. burgdorferi

    OpenAIRE

    Matthew B Lawrenz; Kawabata, Hiroki; Purser, Joye E.; Norris, Steven J

    2002-01-01

    The presence of the linear plasmids lp25 and lp56 of Borrelia burgdorferi B31 was found to dramatically decrease the rate of transformation by electroporation with the shuttle vector pBSV2, an autonomously replicating plasmid that confers kanamycin resistance (P. E. Stewart, R. Thalken, J. L. Bono, and P. Rosa, Mol. Microbiol. 39:714-721, 2001). B. burgdorferi B31 clones had transformation efficiencies that were either low, intermediate, or high, and this phenotype correlated with the presenc...

  9. ELISA-Based Measurement of Antibody Responses and PCR-Based Detection Profiles Can Distinguish between Active Infection and Early Clearance of Borrelia burgdorferi

    OpenAIRE

    Lazarus, John J.; McCarter, Akisha L.; Kari Neifer-Sadhwani; R. Mark Wooten

    2012-01-01

    Borrelia burgdorferi is a spirochetal bacterium that causes Lyme disease. These studies address whether current research methods using either ELISA to detect seroconversion to B. burgdorferi antigens or PCR quantification of bacterial DNA within tissues can accurately distinguish between a productive infection versus a B. burgdorferi exposure that is rapidly cleared by the innate responses. Mice receiving even minimal doses of live B. burgdorferi produced significantly more B. burgdorferi-spe...

  10. Development and validation of a FACS-based lipoprotein localization screen in the Lyme disease spirochete Borrelia burgdorferi

    Directory of Open Access Journals (Sweden)

    Slusser Joyce G

    2010-11-01

    Full Text Available Abstract Background In our previous studies on lipoprotein secretion in the Lyme disease spirochete Borrelia burgdorferi, we used monomeric red fluorescent protein 1 (mRFP1 fused to specifically mutated outer surface protein A (OspA N-terminal lipopeptides to gather first insights into lipoprotein sorting determinants. OspA:mRFP1 fusions could be detected by epifluorescence microscopy both in the periplasm and on the bacterial surface. To build on these findings and to complement the prior targeted mutagenesis approach, we set out to develop a screen to probe a random mutagenesis expression library for mutants expressing differentially localized lipoproteins. Results A Glu-Asp codon pair in the inner membrane-localized OspA20:mRFP1 fusion was chosen for mutagenesis since the two negative charges were previously shown to define the phenotype. A library of random mutants in the two codons was generated and expressed in B. burgdorferi. In situ surface proteolysis combined with fluorescence activated cell sorting (FACS was then used to screen for viable spirochetes expressing alternative subsurface OspA:mRFP1 fusions. Analysis of 93 clones randomly picked from a sorted cell population identified a total of 43 distinct mutants. Protein localization assays indicated a significant enrichment in the selected subsurface phenotype. Interestingly, a majority of the subsurface mutant proteins localized to the outer membrane, indicating their impairment in "flipping" through the outer membrane to the spirochetal surface. OspA20:mRFP1 remained the protein most restricted to the inner membrane. Conclusions Together, these results validate this FACS-based screen for lipoprotein localization and suggest a rather specific inner membrane retention mechanism involving membrane anchor-proximal negative charge patches in this model B. burgdorferi lipoprotein system.

  11. Distribution of Borrelia burgdorferi Sensu Lato in China▿†

    OpenAIRE

    Hao, Qin; Hou, Xuexia; Geng, Zhen; Wan, Kanglin

    2011-01-01

    We genotyped 102 Borrelia burgdorferi sensu lato strains isolated from ticks, animals, and patients in 11 provinces in China by PCR–restriction fragment length polymorphism (PCR-RFLP) amplification of 5S (rrf)-23S (rrl) rRNA gene spacer amplicons and multilocus sequence analysis (MLSA). The results showed that Borrelia garinii was the main genotype in China (65/102) and that it was distributed mainly in northern China. Borrelia afzelii was the second most frequently found species (22/102), an...

  12. In vitro susceptibilities of Borrelia burgdorferi to five oral cephalosporins and ceftriaxone.

    OpenAIRE

    Agger, W A; Callister, S M; Jobe, D A

    1992-01-01

    We determined the in vitro susceptibilities of eight Borrelia burgdorferi isolates to five oral cephalosporins. MICs for B. burgdorferi 297 were 23 micrograms/ml (cephalexin), 45 micrograms/ml (cefadroxil), 91 micrograms/ml (cefaclor), 0.13 microgram/ml (cefuroxime), 0.8 microgram/ml (cefixime), and 0.02 microgram/ml (ceftriaxone). When B. burgdorferi isolates were exposed to concentrations twice the MIC of cefuroxime, cefixime, or ceftriaxone, at least 72 h of incubation was required to kill...

  13. Polymerase chain reaction in diagnosis of Borrelia burgdorferi infections and studies on taxonomic classification

    DEFF Research Database (Denmark)

    Lebech, Anne-Mette

    2002-01-01

    Lyme borreliosis caused by the spirochete Borrelia burgdorferi is now the most common vectorborne disease in North America, Europe and Asia. It is a multisystemic infection which may cause skin, neurological, cardiac or rheumatologic disorders. The aims of the present thesis were: (i) to develop a...... PCR assay for direct detection of B. burgdorferi DNA and to evaluate the diagnostic utility of PCR in clinical specimens from patients with Lyme borreliosis and (ii) to study the taxonomic classification of B. burgdorferi isolates and its implications for epidemiology and clinical presentation....... Laboratory diagnosis of Lyme borreliosis by direct demonstration of B. burgdorferi in clinical specimens would compared to current serology allow (i) optimal specificity, (ii) increased sensitivity during the first weeks of infection, when the antibody response is not yet detectable and (iii) discrimination...

  14. Conservation and Heterogeneity of vlsE among Human and Tick Isolates of Borrelia burgdorferi

    OpenAIRE

    Iyer, Radha; Hardham, John M.; Wormser, Gary P.; Schwartz, Ira; Norris, Steven J

    2000-01-01

    The vls (variable major protein [VMP]-like sequence) locus of Borrelia burgdorferi encodes an antigenic variation system that closely resembles the VMP system of relapsing fever borreliae. To determine whether vls sequences are present consistently in low-passage, infectious isolates of B. burgdorferi, 22 blood and erythema migrans biopsy isolates from Lyme disease patients in Westchester County, New York, were examined by Southern blot and PCR analysis. Each of the strains contained a single...

  15. SERUM ANTIBODIES TO BORRELIA BURGDORFERI, ANAPLASMA PHAGOCYTOPHILUM, AND BABESIA MICROTI IN RECAPTURED WHITE-FOOTED MICE

    OpenAIRE

    Magnarelli, Louis A.; Williams, Scott C.; Norris, Steven J; Fikrig, Erol

    2013-01-01

    A mark-release-recapture study was conducted during 2007 through 2010 in six, tick-infested sites in Connecticut, United States to measure changes in antibody titers for Borrelia burgdorferi sensu stricto, Anaplasma phagocytophilum, and Babesia microti in Peromyscus leucopus (white-footed mice). There was an overall recapture rate of 40%, but only four tagged mice were caught in ≥2 yr. Sera from 561 mice were analyzed for total antibodies to B. burgdorferi and A. phagocytophilum by using whol...

  16. Borrelia burgdorferi aggrecanase activity: more evidence for persistent infection in Lyme disease

    OpenAIRE

    Stricker, Raphael B.; Johnson, Lorraine

    2013-01-01

    Lyme disease is the most common tickborne illness in the world today. A recent study describes for the first time an enzyme produced by the spirochetal agent of Lyme disease, Borrelia burgdorferi, that cleaves aggrecan, a proteoglycan found in joints and connective tissue. Discovery of the spirochetal aggrecanase raises many questions about the pathogenesis of Lyme arthritis and lends support to the concept of persistent B. burgdorferi infection in patients with chronic Lyme disease symptoms.

  17. Whole genome sequence of an unusual Borrelia burgdorferi sensu lato isolate

    Energy Technology Data Exchange (ETDEWEB)

    Casjens, S.R.; Dunn, J.; Fraser-Liggett, C. M.; Mongodin, E. F.; Qiu, W. G.; Luft, B. J.; Schutzer, S. E.

    2011-03-01

    Human Lyme disease is caused by a number of related Borrelia burgdorferi sensu lato species. We report here the complete genome sequence of Borrelia sp. isolate SV1 from Finland. This isolate is to date the closest known relative of B. burgdorferi sensu stricto, but it is sufficiently genetically distinct from that species that it and its close relatives warrant its candidacy for new-species status. We suggest that this isolate should be named 'Borrelia finlandensis.'

  18. Survey for Ixodes spp. and Borrelia burgdorferi in southeastern Wisconsin and northeastern Illinois.

    OpenAIRE

    Callister, S M; Nelson, J A; Schell, R F; Jobe, D A; Bautz, R; Agger, W A; Coggins, J

    1991-01-01

    Forested areas adjacent to Milwaukee, Wis., and Chicago, Ill., were investigated for rodents and ticks infected with Borrelia burgdorferi, the causative agent of Lyme disease. White-footed mice (Peromyscus leucopus or Peromyscus maniculatus), meadow voles (Microtus pennsylvanicus), and eastern chipmunks (Tamias striatus) were captured; and specimens from these animals were cultured for B. burgdorferi to define whether the midwestern Lyme disease area currently encompasses these large metropol...

  19. Molecular characterization of Borrelia burgdorferi sensu lato strains isolated in the area of Belgrade, Serbia Caracterização molecular de cepas de Borrelia burgdorferi sensu lato isoladas na região de Belgrado, Sérvia

    OpenAIRE

    Elizabeta S. Ristanovic; Kayoko Kitamura; Toshiyuki Masuzawa; Marija J. Milutinovic; Radovan M. Cekanac; Novica T. Stajkovic; Danijela M. Zivanovic

    2007-01-01

    This is the first report of the molecular characterization and identification of Borrelia burgdorferi sensu lato strains isolated in Serbia. Isolates A1, A2 and M1, from Ixodes ricinus, belong to Borrelia burgdorferi sensu stricto, while isolate K1 from Apodemus flavicollis is a mixture of Borrelia afzelii and B. burgdorferi s.s.Trata-se do primeiro relato de identificação e caracterização molecular de cepas de Borrelia burgdorferi sensu lato isoladas na região de Belgrado, Sérvia. As cepas A...

  20. Molecular Characterization of Borrelia burgdorferi Linear Plasmids by DNA Hybridization, PCR, Two-Dimensional Gel Electrophoresis, and Electron Microscopy

    OpenAIRE

    Karami, Ali; HOSSEYNI, Seyed Mohammad Javad; KIARUDI, Yaser

    2007-01-01

    Borrelia burgdorferi sensu stricto is the predominant cause of Lyme disease. B. burgdorferi strains carry several linear and circular plasmids and this may be also used as a distinguishing property of the bacteria. The presence of a mixed population of linear and circular plasmids makes separation and characterization of each kind very difficult. In this study, 7 clinical strains of skin and CSF isolates were determined by clonal selection and plasmid profile of B. burgdorferi by electron mic...

  1. Molecular Evidence of Coinfection of Ticks with Borrelia burgdorferi Sensu Lato and the Human Granulocytic Ehrlichiosis Agent in Switzerland

    OpenAIRE

    Leutenegger, Christian M.; Pusterla, Nicola; Mislin, Caroline N.; Weber, Rainer; Lutz, Hans

    1999-01-01

    Adult Ixodes ricinus ticks were collected in Switzerland and tested for the presence of coinfection with Borrelia burgdorferi sensu lato and the human granulocytic ehrlichiosis (HGE) agent by real-time PCR. Of 100 ticks, 49% were positive for B. burgdorferi and 2% were positive for the HGE agent. The two HGE agent-positive ticks were also found to be positive for B. burgdorferi.

  2. Complement-mediated killing of Borrelia burgdorferi by nonimmune sera from sika deer.

    Science.gov (United States)

    Nelson, D R; Rooney, S; Miller, N J; Mather, T N

    2000-12-01

    Various species of cervid deer are the preferred hosts for adult, black-legged ticks (Ixodes scapularis and Ixodes pacificus) in the United States. Although frequently exposed to the agent of Lyme disease (Borrelia burgdorferi), these animals, for the most part, are incompetent as transmission reservoirs. We examined the borreliacidal activity of normal and B. burgdorferi-immune sera from sika deer (Cervus nippon) maintained in a laboratory setting and compared it to that of similar sera from reservoir-competent mice and rabbits. All normal deer sera (NDS) tested killed > 90% of B. burgdorferi cells. In contrast, normal mouse and rabbit sera killed 1:1,024. Heat treatment (56 C, 30 min) of NDS reduced borreliacidal activity, with 90% of the cells killed. Addition of 10 mM EDTA reduced the killing to approximately 30%, whereas the addition of Mg2+ (10 mM) restored borreliacidal activity to NDS. The addition of zymosan A, an activator of the alternative pathway, increased the survival of B. burgdorferi cells to approximately 80% in NDS. These data suggest that the alternative complement activation pathway plays a major role in the borreliacidal activity of NDS. Additionally, 10 mM EGTA had almost no effect on the killing activity of B. burgdorferi-exposed deer sera, suggesting that the classical pathway is not involved in Borrelia killing, even in sera from B. burgdorferi-exposed deer. PMID:11191897

  3. Fourier transform infrared spectroscopy of DNA from Borrelia burgdorferi sensu lato and Ixodes ricinus ticks

    Science.gov (United States)

    Muntean, Cristina M.; Stefan, Razvan; Bindea, Maria; Cozma, Vasile

    2013-06-01

    In this work we present a method for detection of motile and immotile Borrelia burgdorferi genomic DNA, in relation with infectious and noninfectious spirochetes. An FT-IR study of DNA isolated from B. burgdorferi sensu lato strains and from positive and negative Ixodes ricinus ticks, respectively, is reported. Motile bacterial cells from the species B. burgdorferi sensu stricto, Borrelia garinii and Borrelia afzelii were of interest. Also, FT-IR absorbance spectra of DNA from immotile spirochetes of B. burgdorferi sensu stricto, in the absence and presence of different antibiotics (doxycycline, erythromycin, gentamicin, penicillin V or phenoxymethylpenicillin, tetracycline, respectively) were investigated. FT-IR spectra, providing a high molecular structural information, have been analyzed in the wavenumber range 400-1800 cm-1. FT-IR signatures, spectroscopic band assignments and structural interpretations of these DNAs are reported. Spectral differences between FT-IR absorbances of DNAs from motile bacterial cells and immotile spirochetes, respectively, have been found. Particularly, alterations of the sugar-phosphate B-form chain in the case of DNA from Borrelia immotile cells, as compared with DNA from B. burgdorferi sensu lato motile cells have been observed. Based on this work, specific B. burgdorferi sensu lato and I. ricinus DNA-ligand interactions, respectively, might be further investigated using Fourier transform infrared spectroscopy.

  4. Genetic Characterization of Four Strains Borrelia Burgdorferi Isolated in China

    Institute of Scientific and Technical Information of China (English)

    曾霞; 王树声; 张涛; 毕胜利; 周永东

    2004-01-01

    To study the genetic characterization of four strains of Borrelia burgdorferi isolated in China. PCR technique was used to amplify the 5S-23S rRNA intergenic spacer DNA from the whole cellular DNA of isolated GXLD-4, 9, 18 and Chang 14, and then the amplified products were cloned into plasmid pGEM-T Easy and sequenced. It was found that the 5S-23S rRNA intergenic spacer DNA of the four isolates was 242 bp, revealing the nucleotide sequence identity of more than 99%. The four isolates had higher sequence identify with Borrelia valaisiana than with other genetic groups. These four isolates most likely belong to Borrelia valaisiana genomic group.

  5. Resurgence of persisting non-cultivable Borrelia burgdorferi following antibiotic treatment in mice.

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    Emir Hodzic

    Full Text Available The agent of Lyme borreliosis, Borrelia burgdorferi, evades host immunity and establishes persistent infections in its varied mammalian hosts. This persistent biology may pose challenges to effective antibiotic treatment. Experimental studies in dogs, mice, and non-human primates have found persistence of B. burgdorferi DNA following treatment with a variety of antibiotics, but persisting spirochetes are non-cultivable. Persistence of B. burgdorferi DNA has been documented in humans following treatment, but the significance remains unknown. The present study utilized a ceftriaxone treatment regimen in the C3H mouse model that resulted in persistence of non-cultivable B. burgdorferi in order to determine their long-term fate, and to examine their effects on the host. Results confirmed previous studies, in which B. burgdorferi could not be cultured from tissues, but low copy numbers of B. burgdorferi flaB DNA were detectable in tissues at 2, 4 and 8 months after completion of treatment, and the rate of PCR-positive tissues appeared to progressively decline over time. However, there was resurgence of spirochete flaB DNA in multiple tissues at 12 months, with flaB DNA copy levels nearly equivalent to those found in saline-treated mice. Despite the continued non-cultivable state, RNA transcription of multiple B. burgdorferi genes was detected in host tissues, flaB DNA was acquired by xenodiagnostic ticks, and spirochetal forms could be visualized within ticks and mouse tissues by immunofluorescence and immunohistochemistry, respectively. A number of host cytokines were up- or down-regulated in tissues of both saline- and antibiotic-treated mice in the absence of histopathology, indicating host response to the presence of non-cultivable, despite the lack of inflammation in tissues.

  6. Suppression of Long-Lived Humoral Immunity Following Borrelia burgdorferi Infection.

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    Rebecca A Elsner

    2015-07-01

    Full Text Available Lyme Disease caused by infection with Borrelia burgdorferi is an emerging infectious disease and already by far the most common vector-borne disease in the U.S. Similar to many other infections, infection with B. burgdorferi results in strong antibody response induction, which can be used clinically as a diagnostic measure of prior exposure. However, clinical studies have shown a sometimes-precipitous decline of such antibodies shortly following antibiotic treatment, revealing a potential deficit in the host's ability to induce and/or maintain long-term protective antibodies. This is further supported by reports of frequent repeat infections with B. burgdorferi in endemic areas. The mechanisms underlying such a lack of long-term humoral immunity, however, remain unknown. We show here that B. burgdorferi infected mice show a similar rapid disappearance of Borrelia-specific antibodies after infection and subsequent antibiotic treatment. This failure was associated with development of only short-lived germinal centers, micro-anatomical locations from which long-lived immunity originates. These showed structural abnormalities and failed to induce memory B cells and long-lived plasma cells for months after the infection, rendering the mice susceptible to reinfection with the same strain of B. burgdorferi. The inability to induce long-lived immune responses was not due to the particular nature of the immunogenic antigens of B. burgdorferi, as antibodies to both T-dependent and T-independent Borrelia antigens lacked longevity and B cell memory induction. Furthermore, influenza immunization administered at the time of Borrelia infection also failed to induce robust antibody responses, dramatically reducing the protective antiviral capacity of the humoral response. Collectively, these studies show that B. burgdorferi-infection results in targeted and temporary immunosuppression of the host and bring new insight into the mechanisms underlying the failure

  7. In Vitro Susceptibility Testing of Four Antibiotics against Borrelia burgdorferi: a Comparison of Results for the Three Genospecies Borrelia afzelii, Borrelia garinii, and Borrelia burgdorferi Sensu Stricto

    OpenAIRE

    Sicklinger, Martin; Wienecke, Ralf; Neubert, Uwe

    2003-01-01

    MICs and minimal bactericidal concentrations (MBCs) were evaluated for the four antibiotics azithromycin, amoxicillin, ceftriaxone, and doxycycline against the three main genospecies of Borrelia burgdorferi sensu lato. In MBC testing, statistically significant differences between the genospecies could be found in 7 out of 12 comparative evaluations (P < 0.05).

  8. Rapid Typing of Borrelia burgdorferi Sensu Lato Species in Specimens from Patients with Different Manifestations of Lyme Borreliosis

    OpenAIRE

    Lünemann, Jan D.; Zarmas, Silvia; Priem, Susanne; Franz, Juliane; Zschenderlein, Rolf; Aberer, Elisabeth; Klein, Rolf; Schouls, Leon; Burmester, Gerd R.; Krause, Andreas

    2001-01-01

    To further investigate the pathogenic potential of different Borrelia burgdorferi genospecies, specimens from 27 patients with different manifestations of Lyme borreliosis were analyzed by PCR and reverse line blotting (RLB). In samples from Lyme arthritis patients, B. burgdorferi sensu stricto was predominantly identified, while in patients with neuroborreliosis or acrodermatitis, Borrelia garinii and Borrelia afzelii, respectively, were exclusively detected. The results demonstrate that PCR...

  9. Study of the effect of \\kur{Borrelia burgdorferi} infection on the behaviour of Ixodes ricinus tick

    OpenAIRE

    HUSPEKOVÁ, Helena

    2014-01-01

    The main goal of this master thesis was to determine whether or not is the infection with Borrelia burgdorferi sensu lato responsible for changes in Ixodes ricinus tick behaviour. We tried to investigate if B. burgdorferi infection changes the time required for blood feeding, tick activity, phototaxis and amount of blood which is engorged by the tick.

  10. Identification of related DNA sequences in Borrelia burgdorferi and two strains of Leptospira interrogans by using polymerase chain reaction.

    OpenAIRE

    Kron, M A; Gupta, A; Mackenzie, C. D.

    1991-01-01

    The suitability of a polymerase chain reaction assay for Borrelia burgdorferi in epidemiological studies of infected tick populations was evaluated by using 28 strains of Leptospira interrogans and lysates of fixed adult Ixodes tick tissues. Two false positives representing leptospires were differentiated from B. burgdorferi by using an oligonucleotide probe.

  11. Genotypic diversity of an emergent population of Borrelia burgdorferi at a coastal Maine island recently colonized by Ixodes scapularis.

    Science.gov (United States)

    MacQueen, Douglas D; Lubelczyk, Charles; Elias, Susan P; Cahill, Bruce K; Mathers, Amy J; Lacombe, Eleanor H; Rand, Peter W; Smith, Robert P

    2012-06-01

    The recent range expansion of Ixodes scapularis has been accompanied by the emergence of Borrelia burgdorferi. The development of genetic diversity in B. burgdorferi at these sites of emergence and its relationship to range expansion is poorly understood. We followed colonization of I. scapularis on a coastal Maine island over a 17-year period. B. burgdorferi's emergence was documented, as was expansion of ospC strain diversity. Ticks collected from rodents and vegetation were examined for the presence of B. burgdorferi. Sequencing and reverse line blot were used to detect B. burgdorferi ospC major groups (oMG). No I. scapularis were found until year four of the study, after which time they increased in abundance. No B. burgdorferi was detected by darkfield microscopy in I. scapularis until 10 years into the study, when 4% of adult ticks were infected. Seven years later, 43% of adult ticks were infected. In 2003, one oMG accounted for 91% of B. burgdorferi strains. This "founder" strain persisted in 2005, but by 2007 was a minority of the 7 oMGs present. Given the island's isolation, gene flow by avian introduction of multiple strains is suggested in the development of B. burgdorferi oMG diversity. PMID:22217172

  12. Central role of the Holliday junction helicase RuvAB in vlsE recombination and infectivity of Borrelia burgdorferi.

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    Tao Lin

    2009-12-01

    Full Text Available Antigenic variation plays a vital role in the pathogenesis of many infectious bacteria and protozoa including Borrelia burgdorferi, the causative agent of Lyme disease. VlsE, a 35 kDa surface-exposed lipoprotein, undergoes antigenic variation during B. burgdorferi infection of mammalian hosts, and is believed to be a critical mechanism by which the spirochetes evade immune clearance. Random, segmental recombination between the expressed vlsE gene and adjacent vls silent cassettes generates a large number of different VlsE variants within the infected host. Although the occurrence and importance of vlsE sequence variation is well established, little is known about the biological mechanism of vlsE recombination. To identify factors important in antigenic variation and vlsE recombination, we screened transposon mutants of genes known to be involved in DNA recombination and repair for their effects on infectivity and vlsE recombination. Several mutants, including those in BB0023 (ruvA, BB0022 (ruvB, BB0797 (mutS, and BB0098 (mutS-II, showed reduced infectivity in immunocompetent C3H/HeN mice. Mutants in ruvA and ruvB exhibited greatly reduced rates of vlsE recombination in C3H/HeN mice, as determined by restriction fragment polymorphism (RFLP screening and DNA sequence analysis. In severe combined immunodeficiency (C3H/scid mice, the ruvA mutant retained full infectivity; however, all recovered clones retained the 'parental' vlsE sequence, consistent with low rates of vlsE recombination. These results suggest that the reduced infectivity of ruvA and ruvB mutants is the result of ineffective vlsE recombination and underscores the important role that vlsE recombination plays in immune evasion. Based on functional studies in other organisms, the RuvAB complex of B. burgdorferi may promote branch migration of Holliday junctions during vlsE recombination. Our findings are consistent with those in the accompanying article by Dresser et al., and together

  13. First isolation and cultivation of Borrelia burgdorferi sensu lato from Missouri.

    Science.gov (United States)

    Oliver, J H; Kollars, T M; Chandler, F W; James, A M; Masters, E J; Lane, R S; Huey, L O

    1998-01-01

    Five Borrelia burgdorferi sensu lato isolates from Missouri are described. This represents the first report and characterization of such isolates from that state. The isolates were obtained from either Ixodes dentatus or Amblyomma americanum ticks that had been feeding on cottontail rabbits (Sylvilagus floridanus) from a farm in Bollinger County, Mo., where a human case of Lyme disease had been reported. All isolates were screened immunologically by indirect immunofluorescence by using monoclonal antibodies to B. burgdorferi-specific outer surface protein A (OspA) (antibodies H3TS and H5332), B. burgdorferi-specific OspB (antibody H6831), Borrelia (genus)-specific antiflagellin (antibody H9724), and Borrelia hermsii-specific antibody (antibody H9826). Analysis of the isolates also involved a comparison of their protein profiles by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Finally, the isolates were analyzed by PCR with six pairs of primers known to amplify selected DNA target sequences specifically found in the reference strain B. burgdorferi B-31. Although some genetic variability was detected among the five isolates as well as between them and the B-31 strain, enough similarities were found to classify them as B. burgdorferi sensu lato. PMID:9431909

  14. Borrelia burgdorferi in ticks and dogs in the province of Vojvodina, Serbia*

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    Savić S.

    2010-12-01

    Full Text Available Lyme disease is a tick borne zoonotic infection, caused by Borrelia burgdorferi s.l. bacteria. For the transmission of the disease, the presence of ticks is a prerequisite. Lyme borreliosis mostly occurs in people and dogs, but it may occur in other animals. Ticks which carry B. burgdorferi s.l. in Serbia are of the Ixodes ricinus specis. In Serbia, Lyme disease was detected for the first time in the late ‘80-es. In dogs, clinical symptoms may occur even months after a tick bite, and include weakness, lymphadenopathy, fever, lameness, arthritis, etc. In our survey, we have observed tick and dog populations in the province of Vojvodina (northern part of Serbia. I. ricinus ticks were collected and examined for the presence of B. burgdorferi s.l. in several chosen locations. In addition, blood samples were collected from house dogs and pets from the same locations, and analyzed for the presence of antibodies specific for B. burgdorferi s.l. The results showed a mean infection of ticks of 22.12 %, and a mean seroprevalence of Lyme disease in dogs of 25.81 %. We conclude that in Vojvodina there is an actual risk of Lyme borreliosis for other animals and humans, because of the persistence of B. burgdorferi s.l. in both tick and dog populations.

  15. Lyme Disease: antibodies against Borrelia burgdorferi in farm workers in Argentina

    Directory of Open Access Journals (Sweden)

    Stanchi Nestor Oscar

    1993-01-01

    Full Text Available Lyme Disease is a tick-borne (specially by Ixodes ticks immune-mediated inflammatory disorder caused by a newly recognize spirochete, Borrelia burgdorferi. Indirect fluorescent antibody (IF staining methods and enzyme-linked immunosorbent assay are frequently relied upon to confirm Lyme borreliosis infections. Although serologic testing for antibodies has limitations, it is still the only practical means of confirming B. burgdorferi infections. Because we have no previous report of Lyme disease in human inhabitants in Argentina, a study was designed as a seroepidemiologic investigation of the immune response to B. burgdorferi in farm workers of Argentina with arthritis symptoms. Three out of 28 sera were positive (#1,5 and 9. Serum # 1 was positive for Immunoglobulin G at dilution 1:320, serum # 5 and # 9 both to dilution 1:160; while for Immunoglobulin M all (#1, 5 and 9 were positive at low dilution (1:40 using IF. The results showed that antibodies against B. burgdorferi are present in an Argentinian population. Thus caution should be exercised in the clinical interpretation of arthritis until the presence of B. burgdorferi be confirmed by culture in specific media.

  16. Lyme Disease: antibodies against Borrelia burgdorferi in farm workers in Argentina

    Directory of Open Access Journals (Sweden)

    Nestor Oscar Stanchi

    1993-08-01

    Full Text Available Lyme Disease is a tick-borne (specially by Ixodes ticks immune-mediated inflammatory disorder caused by a newly recognize spirochete, Borrelia burgdorferi. Indirect fluorescent antibody (IF staining methods and enzyme-linked immunosorbent assay are frequently relied upon to confirm Lyme borreliosis infections. Although serologic testing for antibodies has limitations, it is still the only practical means of confirming B. burgdorferi infections. Because we have no previous report of Lyme disease in human inhabitants in Argentina, a study was designed as a seroepidemiologic investigation of the immune response to B. burgdorferi in farm workers of Argentina with arthritis symptoms. Three out of 28 sera were positive (#1,5 and 9. Serum # 1 was positive for Immunoglobulin G at dilution 1:320, serum # 5 and # 9 both to dilution 1:160; while for Immunoglobulin M all (#1, 5 and 9 were positive at low dilution (1:40 using IF. The results showed that antibodies against B. burgdorferi are present in an Argentinian population. Thus caution should be exercised in the clinical interpretation of arthritis until the presence of B. burgdorferi be confirmed by culture in specific media.

  17. Differences in Genotype, Clinical Features, and Inflammatory Potential of Borrelia burgdorferi sensu stricto Strains from Europe and the United States.

    Science.gov (United States)

    Cerar, Tjasa; Strle, Franc; Stupica, Dasa; Ruzic-Sabljic, Eva; McHugh, Gail; Steere, Allen C; Strle, Klemen

    2016-05-01

    Borrelia burgdorferi sensu stricto isolates from patients with erythema migrans in Europe and the United States were compared by genotype, clinical features of infection, and inflammatory potential. Analysis of outer surface protein C and multilocus sequence typing showed that strains from these 2 regions represent distinct genotypes. Clinical features of infection with B. burgdorferi in Slovenia were similar to infection with B. afzelii or B. garinii, the other 2 Borrelia spp. that cause disease in Europe, whereas B. burgdorferi strains from the United States were associated with more severe disease. Moreover, B. burgdorferi strains from the United States induced peripheral blood mononuclear cells to secrete higher levels of cytokines and chemokines associated with innate and Th1-adaptive immune responses, whereas strains from Europe induced greater Th17-associated responses. Thus, strains of the same B. burgdorferi species from Europe and the United States represent distinct clonal lineages that vary in virulence and inflammatory potential. PMID:27088349

  18. Borrelia burgdorferi requires glycerol for maximum fitness during the tick phase of the enzootic cycle.

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    Christopher J Pappas

    2011-07-01

    Full Text Available Borrelia burgdorferi, the spirochetal agent of Lyme disease, is a vector-borne pathogen that cycles between a mammalian host and tick vector. This complex life cycle requires that the spirochete modulate its gene expression program to facilitate growth and maintenance in these diverse milieus. B. burgdorferi contains an operon that is predicted to encode proteins that would mediate the uptake and conversion of glycerol to dihydroxyacetone phosphate. Previous studies indicated that expression of the operon is elevated at 23°C and is repressed in the presence of the alternative sigma factor RpoS, suggesting that glycerol utilization may play an important role during the tick phase. This possibility was further explored in the current study by expression analysis and mutagenesis of glpD, a gene predicted to encode glycerol 3-phosphate dehydrogenase. Transcript levels for glpD were significantly lower in mouse joints relative to their levels in ticks. Expression of GlpD protein was repressed in an RpoS-dependent manner during growth of spirochetes within dialysis membrane chambers implanted in rat peritoneal cavities. In medium supplemented with glycerol as the principal carbohydrate, wild-type B. burgdorferi grew to a significantly higher cell density than glpD mutant spirochetes during growth in vitro at 25°C. glpD mutant spirochetes were fully infectious in mice by either needle or tick inoculation. In contrast, glpD mutants grew to significantly lower densities than wild-type B. burgdorferi in nymphal ticks and displayed a replication defect in feeding nymphs. The findings suggest that B. burgdorferi undergoes a switch in carbohydrate utilization during the mammal to tick transition. Further, the results demonstrate that the ability to utilize glycerol as a carbohydrate source for glycolysis during the tick phase of the infectious cycle is critical for maximal B. burgdorferi fitness.

  19. Borrelia burgdorferi Requires Glycerol for Maximum Fitness During The Tick Phase of the Enzootic Cycle

    Science.gov (United States)

    Pappas, Christopher J.; Iyer, Radha; Petzke, Mary M.; Caimano, Melissa J.; Radolf, Justin D.; Schwartz, Ira

    2011-01-01

    Borrelia burgdorferi, the spirochetal agent of Lyme disease, is a vector-borne pathogen that cycles between a mammalian host and tick vector. This complex life cycle requires that the spirochete modulate its gene expression program to facilitate growth and maintenance in these diverse milieus. B. burgdorferi contains an operon that is predicted to encode proteins that would mediate the uptake and conversion of glycerol to dihydroxyacetone phosphate. Previous studies indicated that expression of the operon is elevated at 23°C and is repressed in the presence of the alternative sigma factor RpoS, suggesting that glycerol utilization may play an important role during the tick phase. This possibility was further explored in the current study by expression analysis and mutagenesis of glpD, a gene predicted to encode glycerol 3-phosphate dehydrogenase. Transcript levels for glpD were significantly lower in mouse joints relative to their levels in ticks. Expression of GlpD protein was repressed in an RpoS-dependent manner during growth of spirochetes within dialysis membrane chambers implanted in rat peritoneal cavities. In medium supplemented with glycerol as the principal carbohydrate, wild-type B. burgdorferi grew to a significantly higher cell density than glpD mutant spirochetes during growth in vitro at 25°C. glpD mutant spirochetes were fully infectious in mice by either needle or tick inoculation. In contrast, glpD mutants grew to significantly lower densities than wild-type B. burgdorferi in nymphal ticks and displayed a replication defect in feeding nymphs. The findings suggest that B. burgdorferi undergoes a switch in carbohydrate utilization during the mammal to tick transition. Further, the results demonstrate that the ability to utilize glycerol as a carbohydrate source for glycolysis during the tick phase of the infectious cycle is critical for maximal B. burgdorferi fitness. PMID:21750672

  20. Infection of Ixodes ricinus (Acari: Ixodidae) by Borrelia burgdorferi sensu lato in North Africa

    Science.gov (United States)

    Zhioua, E.; Bouattour, A.; Hu, C.M.; Gharbi, M.; Aeschliman, A.; Ginsberg, H.S.; Gern, L.

    1999-01-01

    Free-living adult Ixodes ricinus L. were collected in Amdoun, situated in the Kroumiry mountains in northwestern Tunisia (North Africa). Using direct fluorescence antibody assay, the infection rate of field-collected I. ricinus by Borrelia burgdorferi sensu lato was 30.5% (n = 72). No difference in infection rate was observed between male and female ticks. Spirochetes that had been isolated from I. ricinus from Ain Drahim (Kroumiry Mountains) in 1988 were identified as Borrelia lusitaniae (formerly genospecies PotiB2). This is the first identification of a genospecies of Borrelia burgdorferi sensu lato from the continent of Africa.

  1. Seroprevalence of Borrelia burgdorferi antibodies in white-tailed deer from Texas

    OpenAIRE

    Adetunji, Shakirat A.; Rosina C. Krecek; Castellanos, Gabrielle; Morrill, John C.; Blue-McLendon, Alice; Walt E. Cook; Esteve-Gassent, Maria D.

    2016-01-01

    Lyme Disease is caused by the bacterial pathogen Borrelia burgdorferi, and is transmitted by the tick-vector Ixodes scapularis. It is the most prevalent arthropod-borne disease in the United States. To determine the seroprevalence of B. burgdorferi antibodies in white-tailed deer (Odocoileus virginianus) from Texas, we analyzed serum samples (n = 1493) collected during the 2001–2015 hunting seasons, using indirect ELISA. Samples with higher sero-reactivity (0.803 and above) than the negative ...

  2. Cinética do crescimento de Borrelia burgdorferi (Spirochaetaceae em diferentes meios de cultivo Cinetic growth of Borrelia burgdorferi (Spirochaetacease in different culture media

    Directory of Open Access Journals (Sweden)

    Angela de Oliveira

    2004-06-01

    Full Text Available Estudou-se a cinética de crescimento de Borrelia burgdorferi, por um período de 3 meses, utilizando os seguintes oito meios de cultivo : (1 BSK adicionado de soro de coelho, (2 BSK adicionado de soro de suíno, (3 BSK adicionado de soro de suíno + 5 fluorouracil, (4 PMR, (5 CTB, (6 Dubos, (7 Caldo Brucella e (8 BHI. Todos os meios foram preparados assepticamente e mantidos em tubos de ensaio com capacidade para 10 ml. Para cada meio, o inoculo foi padronizado para conter no início 10² espiroquetas para cada 0,1 ml de cultivo. O monitoramento do crescimento foi feito contando-se o total de espiroquetas em 0,1 ml do meio entre lâmina de microscopia e lamínula com dimen sões de 10x30mm, tendo sido utilizado microscópio de campo escuro. A contagem foi realizada durante 14 semanas, tendo sido diária nos primeiros 12 dias e semanal a partir desta data. Houve crescimento de B. burgdorferi em todos meios testados, com melhor performance para três deles: BSK adicionado de soro de coelho, BSK adicionado de soro de suíno + 5 fluorouracil e meio CTB. Observou-se crescimento de B. burgdorferi a partir da 4ª semana, atingindo o platô de crescimento entre a 8ª e 12ª semanas, quando começou a exaustão do meio de cultivo. Formas císticas de B. burgdorferi foram observadas em todos os meios testados.The cinetic of growth of Borrelia burgdorferi was studied during a 3-month period, using the following 8 culture media: (1 rabbit serum BSK, (2 swine serum BSK, (3 swine serum BSK+5 fluorouracil, (4 PMR, (5 CTB, (6 Dubos, (7 Brucella broth and (8 BHI. All media were prepared aseptically and were maintained in culture tubes of 10 ml capacity. For each medium, the inoculum was standardized to contain initially 10² spirochetes for each 0.1 ml of culture. The growth was monitorized by counting the total number of spirochetes in 0.1ml of medium in a dark field microscope, using a 10x30 mm cover slip. For the first 12 days, counting was done each 24

  3. Lyme Disease: antibodies against Borrelia burgdorferi in farm workers in Argentina Doença de Lyme: anticorpos anti Borrelia burgdorferi nos trabalhadores rurais da Argentina

    Directory of Open Access Journals (Sweden)

    Nestor Oscar Stanchi

    1993-08-01

    Full Text Available Lyme Disease is a tick-borne (specially by Ixodes ticks immune-mediated inflammatory disorder caused by a newly recognize spirochete, Borrelia burgdorferi. Indirect fluorescent antibody (IF staining methods and enzyme-linked immunosorbent assay are frequently relied upon to confirm Lyme borreliosis infections. Although serologic testing for antibodies has limitations, it is still the only practical means of confirming B. burgdorferi infections. Because we have no previous report of Lyme disease in human inhabitants in Argentina, a study was designed as a seroepidemiologic investigation of the immune response to B. burgdorferi in farm workers of Argentina with arthritis symptoms. Three out of 28 sera were positive (#1,5 and 9. Serum # 1 was positive for Immunoglobulin G at dilution 1:320, serum # 5 and # 9 both to dilution 1:160; while for Immunoglobulin M all (#1, 5 and 9 were positive at low dilution (1:40 using IF. The results showed that antibodies against B. burgdorferi are present in an Argentinian population. Thus caution should be exercised in the clinical interpretation of arthritis until the presence of B. burgdorferi be confirmed by culture in specific media.A doença de Lyme, é uma desordem inflamatória, intermediada pelo sistema imunogênico, transmitida por carrapatos (especialmente do Gênero Ixodes e causada por uma espiroqueta recentemente descoberta, a Borrelia burgdorferi. A técnica de Imunofluorescência Indireta (IF é com freqüência usada para confirmar o diagnóstico da infecção por este microrganismo. Embora os métodos práticos tenham limitações, é no entanto o único método prático para seu diagnóstico. Devido a não existência de registros prévios dessa doença na Argentina, foi realizada pesquisa seroepidemiológica para determinar a presença de imunoglobulinas nos trabalhadores rurais da Argentina, com sintomas de artrite. Sobre um total de 28 soros analisados, 3 resultaram positivos (o soro número 1

  4. Population dynamics of Borrelia burgdorferi in Lyme disease

    Directory of Open Access Journals (Sweden)

    SebastianChristophBinder

    2012-03-01

    Full Text Available Many chronic inflammatory diseases are known to be caused by persistent bacterial or viral infections. A well-studied example is the tick-borne infection by the gram-negative Spirochaetes of the genus Borrelia in humans and other mammals, causing severe symptoms of chronic inflammation and subsequent tissue damage (Lyme Disease, particularly in large joints and the central nervous system, but also in the heart and other tissues of untreated patients. Although killed efficiently by human phagocytic cells in vitro, Borrelia exhibits a remarkably high infectivity in mice and men. In experimentally infected mice, the first immune response almost clears the infection. However, approximately one week post infection, the bacterial population recovers and reaches an even larger size before entering the chronic phase. We developed a mathematical model describing the bacterial growth and the immune response against Borrelia burgdorferi in the C3H mouse strain that has been established as an experimental model for Lyme disease. The peculiar dynamics of the infection exclude two possible mechanistic explanations for the regrowth of the almost cleared bacteria. Neither the hypothesis of bacterial dissemination to different tissue nor a limitation of phagocytic capacity were compatible with experiment. The mathematical model predicts that Borrelia recovers from the strong initial immune response by the regrowth of an immune-resistant sub-population of the bacteria. The chronic phase appears as an equilibration of bacterial growth and adaptive immunity. This result has major implications for the development of the chronic phase of Borrelia infections as well as on potential protective clinical interventions.

  5. Multiple infections of Ixodes scapularis ticks by Borrelia burgdorferi as revealed by single-strand conformation polymorphism analysis.

    OpenAIRE

    Guttman, D. S.; Wang, P. W.; Wang, I. N.; Bosler, E. M.; Luft, B J; Dykhuizen, D E

    1996-01-01

    The genetic heterogeneity of the spirochete Borrelia burgdorferi within single adult black-legged ticks from Shelter Island, N.Y., was determined by cold, single-strand conformation polymorphism (SSCP) analysis. The central region of the ospA gene of B. burgdorferi from infected ticks was amplified by nested PCR. Amplified product of the correct size was obtained from 20 to 45 ticks (44%). This is the fraction of ticks that is expected to be infected with B. burgdorferi. Four variant classes ...

  6. The critical role of the linear plasmid lp36 in the infectious cycle of Borrelia burgdorferi.

    Science.gov (United States)

    Jewett, Mollie W; Lawrence, Kevin; Bestor, Aaron C; Tilly, Kit; Grimm, Dorothee; Shaw, Pamela; VanRaden, Mark; Gherardini, Frank; Rosa, Patricia A

    2007-06-01

    Borrelia burgdorferi, the aetiological agent of Lyme disease, follows a life cycle that involves passage between the tick vector and the mammalian host. To investigate the role of the 36 kb linear plasmid, lp36 (also designated the B. burgdorferi K plasmid), in the infectious cycle of B. burgdorferi, we examined a clone lacking this plasmid, but containing all other plasmids known to be required for infectivity. Our results indicated that lp36 was not required for spirochete survival in the tick, but the clone lacking lp36 demonstrated low infectivity in the mammal. Restoration of lp36 to the mutant strain confirmed that the infectivity defect was due to loss of lp36. Moreover, spirochetes lacking lp36 exhibited a nearly 4-log increase in ID(50) relative to the isogenic lp36(+) clone. The infectivity defect of lp36-minus spirochetes was localized, in part, to loss of the bbk17 (adeC) gene, which encodes an adenine deaminase. This work establishes a vital role for lp36 in the infectious cycle of B. burgdorferi and identifies the bbk17 gene as a component of this plasmid that contributes to mammalian infectivity. PMID:17542926

  7. Role of outer membrane architecture in immune evasion by Treponema pallidum and Borrelia burgdorferi.

    Science.gov (United States)

    Radolf, J D

    1994-09-01

    Combined ultrastructural and molecular studies have revealed that the syphilis and Lyme-disease spirochetes, Treponema pallidum and Borrelia burgdorferi, have distinctive molecular architectures. Both organisms persist in their hosts and have strategies for immune evasion that include the use of rare, poorly immunogenic surface-exposed proteins as potential virulence determinants. PMID:7812663

  8. Seroprevalence of Borrelia burgdorferi antibodies in white-tailed deer from Texas.

    Science.gov (United States)

    Adetunji, Shakirat A; Krecek, Rosina C; Castellanos, Gabrielle; Morrill, John C; Blue-McLendon, Alice; Cook, Walt E; Esteve-Gassent, Maria D

    2016-08-01

    Lyme Disease is caused by the bacterial pathogen Borrelia burgdorferi, and is transmitted by the tick-vector Ixodes scapularis. It is the most prevalent arthropod-borne disease in the United States. To determine the seroprevalence of B. burgdorferi antibodies in white-tailed deer (Odocoileus virginianus) from Texas, we analyzed serum samples (n = 1493) collected during the 2001-2015 hunting seasons, using indirect ELISA. Samples with higher sero-reactivity (0.803 and above) than the negative control group (0.662) were further tested using a more specific standardized western immunoblot assay to rule out false positives. Using ELISA, 4.7% of the samples were sero-reactive against B. burgdorferi, and these originated in two eco-regions in Texas (Edwards Plateau and South Texas Plains). However, only 0.5% of the total samples were sero-reactive by standardized western immunoblot assay. Additionally, both ELISA and standardized western immunoblot assay results correlated with an increased incidence in human Lyme Disease cases reported in Texas. This is the first longitudinal study to demonstrate fluctuation in sero-reactivity of white-tailed deer to B. burgdorferi sensu stricto antigens in southern United States. Future ecological and geographical studies are needed to assess the environmental factors governing the prevalence of Lyme Disease in non-endemic areas of the southern United States. PMID:27366674

  9. The urokinase receptor (uPAR) facilitates clearance of Borrelia burgdorferi

    NARCIS (Netherlands)

    J.W.R. Hovius; M.F. Bijlsma; G.J.W. van der Windt; W.J. Wiersinga; B.J.D. Boukens; J. Coumou; A. Oei; R. de Beer; A.F. de Vos; C. van 't Veer; A.P. van Dam; P. Wang; E. Fikrig; M.M. Levi; J.J.T.H. Roelofs; T. van der Poll

    2009-01-01

    The causative agent of Lyme borreliosis, the spirochete Borrelia burgdorferi, has been shown to induce expression of the urokinase receptor (uPAR); however, the role of uPAR in the immune response against Borrelia has never been investigated. uPAR not only acts as a proteinase receptor, but can also

  10. Borrelia burgdorferi sensu lato in humans in a rural area of Paraná State, Brazil

    OpenAIRE

    Daniela Dib Gonçalves; Rodrigo Assunção Moura; Mônica Nunes; Teresa Carreira; Odilon Vidotto; Julio Cesar de Freitas; Maria Luísa Vieira

    2015-01-01

    This study describes the detection of Borrelia garinii and Borrelia burgdorferi sensu stricto (s.s.) in Brazilian individuals using PCR and DNA sequencing. Our results suggest that these species are emerging pathogens in this country, and additional studies are necessary to determine the epidemiological characteristics of this disease in Brazil.

  11. Antibodies against Borrelia burgdorferi sensu lato among Adults, Germany, 2008–2011

    OpenAIRE

    Wilking, Hendrik; Fingerle, Volker; Klier, Christiane; Thamm, Michael; Stark, Klaus

    2015-01-01

    To assess Borrelia burgdorferi sensu lato (the cause of Lyme borreliosis) seropositivity in Germany, we tested serum samples from health survey (2008–2011) participants. Seroprevalence was 5.8% among women and 13.0% among men; infection risk was highest among persons >60 years of age. Public health interventions, including education about risk factors and preventive measures, are needed.

  12. Nod2 suppresses Borrelia burgdorferi mediated murine Lyme arthritis and carditis through the induction of tolerance.

    Directory of Open Access Journals (Sweden)

    Tanja Petnicki-Ocwieja

    Full Text Available The internalization of Borrelia burgdorferi, the causative agent of Lyme disease, by phagocytes is essential for an effective activation of the immune response to this pathogen. The intracellular, cytosolic receptor Nod2 has been shown to play varying roles in either enhancing or attenuating inflammation in response to different infectious agents. We examined the role of Nod2 in responses to B. burgdorferi. In vitro stimulation of Nod2 deficient bone marrow derived macrophages (BMDM resulted in decreased induction of multiple cytokines, interferons and interferon regulated genes compared with wild-type cells. However, B. burgdorferi infection of Nod2 deficient mice resulted in increased rather than decreased arthritis and carditis compared to control mice. We explored multiple potential mechanisms for the paradoxical response in in vivo versus in vitro systems and found that prolonged stimulation with a Nod2 ligand, muramyl dipeptide (MDP, resulted in tolerance to stimulation by B. burgdorferi. This tolerance was lost with stimulation of Nod2 deficient cells that cannot respond to MDP. Cytokine patterns in the tolerance model closely paralleled cytokine profiles in infected Nod2 deficient mice. We propose a model where Nod2 has an enhancing role in activating inflammation in early infection, but moderates inflammation after prolonged exposure to the organism through induction of tolerance.

  13. Borrelia burgdorferi sensu lato in humans in a rural area of Paraná State, Brazil

    Directory of Open Access Journals (Sweden)

    Daniela Dib Gonçalves

    2015-06-01

    Full Text Available This study describes the detection of Borrelia garinii and Borrelia burgdorferi sensu stricto (s.s. in Brazilian individuals using PCR and DNA sequencing. Our results suggest that these species are emerging pathogens in this country, and additional studies are necessary to determine the epidemiological characteristics of this disease in Brazil.

  14. Occurrence of multiple infections with different Borrelia burgdorferi genospecies in Danish Ixodes ricinus nymphs

    DEFF Research Database (Denmark)

    Andersen, Jean Vennestrøm; Egholm, H.; Mikkelsen, Per Jensen

    2008-01-01

    The pathogen Borrelia burgdorferi causes Lyme Borreliosis in human and animals world-wide. In Europe the pathogen is transmitted to the host by the vector Ixodes ricinus. The nymph is the primary instar for transmission to humans. We here study the infection rate of five Borrelia genospecies: B...

  15. Concurrent Borrelia burgdorferi and Babesia microti infection in nymphal Ixodes dammini.

    OpenAIRE

    Piesman, J; Mather, T N; Telford, S R; Spielman, A

    1986-01-01

    Ixodes dammini nymphs were examined for evidence of concurrent infection with Borrelia burgdorferi and Babesia microti. A total of 19 nymphs (18.6%) from Nantucket Island were simultaneously infected, as were 24 nymphs (8.2%) from Naushon Island. These observations are consistent with a common reservoir host for both I. dammini-transmitted pathogens.

  16. Lectin-binding characteristics of a Lyme borreliosis spirochete Borrelia burgdorferi sensu stricto

    Czech Academy of Sciences Publication Activity Database

    Vancová, M.; Nebesářová, J.; Grubhoffer, Libor

    2005-01-01

    Roč. 50, č. 3 (2005), s. 229-238. ISSN 0015-5632 R&D Projects: GA ČR GA206/03/1323; GA AV ČR KSK6005114 Institutional research plan: CEZ:AV0Z60220518 Keywords : Borrelia burgdorferi * electron microscopy * lectin binding Subject RIV: EE - Microbiology, Virology Impact factor: 0.918, year: 2005

  17. BB0172, a Borrelia burgdorferi outer membrane protein that binds integrin α3β1.

    Science.gov (United States)

    Wood, Elaine; Tamborero, Silvia; Mingarro, Ismael; Esteve-Gassent, Maria D

    2013-08-01

    Lyme disease is a multisystemic disorder caused by Borrelia burgdorferi infection. Upon infection, some B. burgdorferi genes are upregulated, including members of the microbial surface components recognizing adhesive matrix molecule (MSCRAMM) protein family, which facilitate B. burgdorferi adherence to extracellular matrix components of the host. Comparative genome analysis has revealed a new family of B. burgdorferi proteins containing the von Willebrand factor A (vWFA) domain. In the present study, we characterized the expression and membrane association of the vWFA domain-containing protein BB0172 by using in vitro transcription/translation systems in the presence of microsomal membranes and with detergent phase separation assays. Our results showed evidence of BB0172 localization in the outer membrane, the orientation of the vWFA domain to the extracellular environment, and its function as a metal ion-dependent integrin-binding protein. This is the first report of a borrelial adhesin with a metal ion-dependent adhesion site (MIDAS) motif that is similar to those observed in eukaryotic integrins and has a similar function. PMID:23687274

  18. NKT cells prevent chronic joint inflammation after infection with Borrelia burgdorferi.

    Science.gov (United States)

    Tupin, Emmanuel; Benhnia, Mohammed Rafii-El-Idrissi; Kinjo, Yuki; Patsey, Rebeca; Lena, Christopher J; Haller, Matthew C; Caimano, Melissa J; Imamura, Masakazu; Wong, Chi-Huey; Crotty, Shane; Radolf, Justin D; Sellati, Timothy J; Kronenberg, Mitchell

    2008-12-16

    Borrelia burgdorferi is the etiologic agent of Lyme disease, a multisystem inflammatory disorder that principally targets the skin, joints, heart, and nervous system. The role of T lymphocytes in the development of chronic inflammation resulting from B. burgdorferi infection has been controversial. We previously showed that natural killer T (NKT) cells with an invariant (i) TCR alpha chain (iNKT cells) recognize glycolipids from B. burgdorferi, but did not establish an in vivo role for iNKT cells in Lyme disease pathogenesis. Here, we evaluate the importance of iNKT cells for host defense against these pathogenic spirochetes by using Valpha14i NKT cell-deficient (Jalpha18(-/-)) BALB/c mice. On tick inoculation with B. burgdorferi, Jalpha18(-/-) mice exhibited more severe and prolonged arthritis as well as a reduced ability to clear spirochetes from infected tissues. Valpha14i NKT cell deficiency also resulted in increased production of antibodies directed against both B. burgdorferi protein antigens and borrelial diacylglycerols; the latter finding demonstrates that anti-glycolipid antibody production does not require cognate help from Valpha14i NKT cells. Valpha14i NKT cells in infected wild-type mice expressed surface activation markers and produced IFNgamma in vivo after infection, suggesting a participatory role for this unique population in cellular immunity. Our data are consistent with the hypothesis that the antigen-specific activation of Valpha14i NKT cells is important for the prevention of persistent joint inflammation and spirochete clearance, and they counter the long-standing notion that humoral rather than cellular immunity is sufficient to facilitate Lyme disease resolution. PMID:19060201

  19. Few vertebrate species dominate the Borrelia burgdorferi s.l. life cycle

    Science.gov (United States)

    Hofmeester, T. R.; Coipan, E. C.; van Wieren, S. E.; Prins, H. H. T.; Takken, W.; Sprong, H.

    2016-04-01

    Background. In the northern hemisphere, ticks of the Ixodidae family are vectors of diseases such as Lyme borreliosis, Rocky Mountain spotted fever and tick-borne encephalitis. Most of these ticks are generalists and have a three-host life cycle for which they are dependent on three different hosts for their blood meal. Finding out which host species contribute most in maintaining ticks and the pathogens they transmit, is imperative in understanding the drivers behind the dynamics of a disease. Methods. We performed a systematic review to identify the most important vertebrate host species for Ixodes ricinus and Borrelia burgdorferi s.l. as a well-studied model system for tick-borne diseases. We analyzed data from 66 publications and quantified the relative contribution for 15 host species. Review results. We found a positive correlation between host body mass and tick burdens for the different stages of I. ricinus. We show that nymphal burdens of host species are positively correlated with infection prevalence with B. burgdorferi s.l., which is again positively correlated with the realized reservoir competence of a host species for B. burgdorferi s.l. Our quantification method suggests that only a few host species, which are amongst the most widespread species in the environment (rodents, thrushes and deer), feed the majority of I. ricinus individuals and that rodents infect the majority of I. ricinus larvae with B. burgdorferi s.l. Discussion. We argue that small mammal-transmitted Borrelia spp. are maintained due to the high density of their reservoir hosts, while bird-transmitted Borrelia spp. are maintained due to the high infection prevalence of their reservoir hosts. Our findings suggest that Ixodes ricinus and Borrelia burgdorferi s.l. populations are maintained by a few widespread host species. The increase in distribution and abundance of these species, could be the cause for the increase in Lyme borreliosis incidence in Europe in recent decades.

  20. Symptomatic co-infection with Babesia microti and Borrelia burgdorferi in patient after international exposure; a challenging case in Poland.

    Science.gov (United States)

    Jabłońska, Joanna; Żarnowska-Prymek, Hanna; Stańczak, Joanna; Kozłowska, Joanna; Wiercińska-Drapało, Alicja

    2016-06-01

    The report presents a well-documented case of symptomatic co-infection of Babesia microti and Borrelia burgdorferi in a Polish immunocompetent patient after travelling to Canada and the USA. PMID:27294655

  1. Different Classes of Proteoglycans Contribute to the Attachment of Borrelia burgdorferi to Cultured Endothelial and Brain Cells

    OpenAIRE

    Leong, John M.; Wang, Hong; Magoun, Loranne; Field, Jodie A.; Morrissey, Pamela E.; Robbins, Douglas; Tatro, Jeffrey B.; Coburn, Jenifer; Parveen, Nikhat

    1998-01-01

    The Lyme disease spirochete, Borrelia burgdorferi, infects multiple tissues, such as the heart, joint, skin, and nervous system and has been shown to recognize heparan sulfate and dermatan sulfate proteoglycans. In this study, we examined the contribution of different classes of proteoglycans to the attachment of the infectious B. burgdorferi strain N40 to several immortalized cell lines and primary cultured cells, including endothelial cells and brain cells. Bacterial attachment was inhibite...

  2. High-Throughput Plasmid Content Analysis of Borrelia burgdorferi B31 by Using Luminex Multiplex Technology▿ †

    OpenAIRE

    Norris, Steven J; Howell, Jerrilyn K.; Odeh, Evelyn A.; Lin, Tao; Gao, Lihui; Diane G Edmondson

    2010-01-01

    Borrelia burgdorferi, the causative agent of Lyme disease in North America, is an invasive pathogen that causes persistent multiorgan manifestations in humans and other mammals. Genetic studies of this bacterium are complicated by the presence of multiple plasmid replicons, many of which are readily lost during in vitro culture. The analysis of B. burgdorferi plasmid content by plasmid-specific PCR and agarose gel electrophoresis or other existing techniques is informative, but these techniqu...

  3. The Thermophilic, Homohexameric Aminopeptidase of Borrelia burgdorferi Is a Member of the M29 Family of Metallopeptidases

    OpenAIRE

    Bertin, Patrícia B.; Silene P Lozzi; Howell, Jerrilyn K.; Restrepo-Cadavid, Glória; Neves, David; Teixeira, Antonio R. L.; de Sousa, Marcelo V.; Norris, Steven J; Santana, Jaime M.

    2005-01-01

    Proteases are implicated in several aspects of the physiology of microorganisms, as well as in host-pathogen interactions. Aminopeptidases are also emerging as novel drug targets in infectious agents. In this study, we have characterized an aminopeptidase from the spirochete Borrelia burgdorferi, the causative agent of Lyme disease. The aminopeptidolytic activity was identified in cell extracts from B. burgdorferi by using the substrate leucine-7-amido-4-methylcoumarin. A protein displaying t...

  4. Critical Analysis of Treatment Trials of Rhesus Macaques Infected with Borrelia burgdorferi Reveals Important Flaws in Experimental Design

    OpenAIRE

    Wormser, Gary P.; Baker, Phillip J.; O'Connell, Susan; Pachner, Andrew R.; Schwartz, Ira; Shapiro, Eugene D.

    2012-01-01

    A critical analysis of two treatment trials of Chinese rhesus macaques infected with Borrelia burgdorferi indicates that insufficient attention was placed on documenting the blood levels, pharmacokinetics, and pharmacodynamic parameters of the antibiotics used in this host. Consequently, it is impossible to conclude that the findings have validity in judging the efficacy of doxycycline or ceftriaxone for the treatment of Borrelia burgdorferi in this animal model.

  5. Identification of glycoproteins in samples of the CB53 isolate of the spirochete \\kur{Borrelia burgdorferi} s.s.

    OpenAIRE

    JONÁKOVÁ, Martina

    2009-01-01

    Glycosylation of Borrelia burgdorferi has been studied for a quite long time, but it's not clear so far, if borrelia spirochetas are able to glycosylate proteins. This work is focused on isolation of glycoproteins from B. burgdorferi outer membranes and periplasmic flagella, on their identification and characterization. My results imply that OspC, FlaB and p83/100 proteins are potentially glycosylated.

  6. Effectiveness of Stevia Rebaudiana Whole Leaf Extract Against the Various Morphological Forms of Borrelia Burgdorferi in Vitro

    OpenAIRE

    Theophilus, P. A. S.; Victoria, M. J.; Socarras, K. M.; Filush, K. R.; Gupta, K.; Luecke, D. F.; Sapi, E.

    2015-01-01

    Lyme disease is a tick-borne multisystemic disease caused by Borrelia burgdorferi. Administering antibiotics is the primary treatment for this disease; however, relapse often occurs when antibiotic treatment is discontinued. The reason for relapse remains unknown, but recent studies suggested the possibilities of the presence of antibiotic resistant Borrelia persister cells and biofilms. In this study, we evaluated the effectiveness of whole leaf Stevia extract against B. burgdorferi spiroche...

  7. Expression and Immunological Analysis of the Plasmid-Borne mlp Genes of Borrelia burgdorferi Strain B31

    OpenAIRE

    Porcella, Stephen F.; Fitzpatrick, Cecily A.; Bono, James L.

    2000-01-01

    A lipoprotein gene family first identified in Borrelia burgdorferi strain 297, designated 2.9 LP and recently renamed mlp, was found on circular and linear plasmids in the genome sequence of B. burgdorferi strain B31-M1. Sequence analyses of the B31 mlp genes and physically linked variant gene families indicated that mlp gene heterogeneity is unique and unrelated to location or linkage to divergent sequences. Evidence of recombination between B31 mlp alleles was also detected. Northern blot a...

  8. Identification, Characterization, and Expression of Three New Members of the Borrelia burgdorferi Mlp (2.9) Lipoprotein Gene Family

    OpenAIRE

    Yang, Xiaofeng; Popova, Taissia G.; Hagman, Kayla E.; Wikel, Stephen K.; Schoeler, George B.; Caimano, Melissa J.; Radolf, Justin D.; Norgard, Michael V.

    1999-01-01

    We previously reported on the existence of a family of lipoprotein genes, designated 2.9 lipoprotein genes, encoded in at least seven versions on the circular (supercoiled) cp32 and cp18 plasmids of Borrelia burgdorferi 297. A distinguishing feature of the 2.9 lipoproteins were highly similar signal sequences but variable mature polypeptides that segregated into two antigenic classes. Further screenings of B. burgdorferi 297 genomic libraries led to the identification of three additional 2.9 ...

  9. Identification of endemic foci of Lyme disease: isolation of Borrelia burgdorferi from feral rodents and ticks (Dermacentor variabilis).

    OpenAIRE

    Anderson, J F; Johnson, R C; Magnarelli, L A; Hyde, F W

    1985-01-01

    Borrelia burgdorferi, the etiological agent of Lyme disease, was isolated from the blood, kidneys, spleens, eyes, or livers of white-footed mice (Peromyscus leucopus) (n = 19 of 22) and from the blood, kidneys, or spleens of eastern chipmunks (Tamias striatus) (n = 2 of 2) captured at three foci for Lyme disease in eastern Connecticut. These bacteria were cultured most frequently from spleens (n = 19) and kidneys (n = 15). B. burgdorferi persisted in one mouse for at least 60 days. One spiroc...

  10. Borrelia burgdorferi Regulates Expression of Complement Regulator-Acquiring Surface Protein 1 during the Mammal-Tick Infection Cycle

    OpenAIRE

    von Lackum, Kate; Miller, Jennifer C.; Bykowski, Tomasz; Riley, Sean P; Woodman, Michael E.; Brade, Volker; Kraiczy, Peter; Stevenson, Brian; Wallich, Reinhard

    2005-01-01

    During the natural mammal-tick infection cycle, the Lyme disease spirochete Borrelia burgdorferi comes into contact with components of the alternative complement pathway. B. burgdorferi, like many other human pathogens, has evolved the immune evasion strategy of binding two host-derived fluid-phase regulators of complement, factor H and factor H-like protein 1 (FHL-1). The borrelial complement regulator-acquiring surface protein 1 (CRASP-1) is a surface-exposed lipoprotein that binds both fac...

  11. Isolation, cultivation, and in vitro susceptibility testing of Borrelia burgdorferi sensu lato: A review

    Directory of Open Access Journals (Sweden)

    Veinović Gorana

    2013-01-01

    Full Text Available Lyme borreliosis is the most common vector-borne disease in the northern hemisphere. The agents of Lyme borreliosis are borrelia, bacteria of the family Spirochaetaceae, which are grouped in Borrelia burgdorferi sensu lato species complex. Borreliae are fastidious, slow-growing and biochemically inactive bacteria that need special attention and optimal conditions for cultivation. The isolation of Borrelia from clinical material and their cultivation is a time-consuming and demanding procedure. Cultivation lasts from 9 up to 12 weeks, which is much longer than is necessary to grow most other human bacterial pathogens. Although B. burgdorferi sensu lato is susceptible to a wide range of antimicrobial agents in vitro, up to now the susceptibility of individual Borrelia species to antibiotics is defined only partially. [Projekat Ministarstva nauke Republike Srbije, br. 175011

  12. Increasing RpoS expression causes cell death in Borrelia burgdorferi.

    Directory of Open Access Journals (Sweden)

    Linxu Chen

    Full Text Available RpoS, one of the two alternative σ factors in Borrelia burgdorferi, is tightly controlled by multiple regulators and, in turn, determines expression of many critical virulence factors. Here we show that increasing RpoS expression causes cell death. The immediate effect of increasing RpoS expression was to promote bacterial division and as a consequence result in a rapid increase in cell number before causing bacterial death. No DNA fragmentation or degradation was observed during this induced cell death. Cryo-electron microscopy showed induced cells first formed blebs, which were eventually released from dying cells. Apparently blebbing initiated cell disintegration leading to cell death. These findings led us to hypothesize that increasing RpoS expression triggers intracellular programs and/or pathways that cause spirochete death. The potential biological significance of induced cell death may help B. burgdorferi regulate its population to maintain its life cycle in nature.

  13. NMR structure of an acyl-carrier protein from Borrelia burgdorferi

    OpenAIRE

    Barnwal, Ravi P.; Van Voorhis, Wesley C.; Varani, G

    2011-01-01

    Nearly complete resonance assignment and the high-resolution NMR structure of the acyl-carrier protein from Borrelia burgdorferi, a target of the Seattle Structural Genomics Center for Infectious Disease (SSGCID) structure-determination pipeline, are reported. This protein was chosen as a potential target for drug-discovery efforts because of its involvement in fatty-acid biosynthesis, an essential metabolic pathway, in bacteria. It was possible to assign >98% of backbone resonances and >92% ...

  14. Cryoelectron tomography reveals the sequential assembly of bacterial flagella in Borrelia burgdorferi

    OpenAIRE

    Zhao, Xiaowei; Zhang, Kai; Boquoi, Tristan; Hu, Bo; Motaleb, M. A.; Miller, Kelly A.; James, Milinda E; Charon, Nyles W.; Manson, Michael D.; Norris, Steven J; Li, Chunhao; Liu, Jun

    2013-01-01

    Periplasmic flagella are essential for the distinctive morphology, motility, and infectious life cycle of the Lyme disease spirochete Borrelia burgdorferi. In this study, we genetically trapped intermediates in flagellar assembly and determined the 3D structures of the intermediates to 4-nm resolution by cryoelectron tomography. We provide structural evidence that secretion of rod substrates triggers remodeling of the central channel in the flagellar secretion apparatus from a closed to an op...

  15. Transcriptional Regulation of the Borrelia burgdorferi Antigenically Variable VlsE Surface Protein

    OpenAIRE

    Bykowski, Tomasz; Babb, Kelly; von Lackum, Kate; Riley, Sean P.; Norris, Steven J; Stevenson, Brian

    2006-01-01

    The Lyme disease agent Borrelia burgdorferi can persistently infect humans and other animals despite host active immune responses. This is facilitated, in part, by the vls locus, a complex system consisting of the vlsE expression site and an adjacent set of 11 to 15 silent vls cassettes. Segments of nonexpressed cassettes recombine with the vlsE region during infection of mammalian hosts, resulting in combinatorial antigenic variation of the VlsE outer surface protein. We now demonstrate that...

  16. Serologic survey of the wild boar (Sus scrofa) for Borrelia burgdorferi sensu lato

    Czech Academy of Sciences Publication Activity Database

    Juřicová, Zina; Hubálek, Zdeněk

    2009-01-01

    Roč. 9, č. 5 (2009), s. 479-482. ISSN 1530-3667 R&D Projects: GA ČR GA524/96/1059 Grant ostatní: 6th Framework Programme EC(XE) GOCE-2003-010284 EDEN Institutional research plan: CEZ:AV0Z60930519 Keywords : Borrelia burgdorferi * Sus scrofa * serosurvey * Czech Republic Subject RIV: GJ - Animal Vermins ; Diseases, Veterinary Medicine Impact factor: 2.607, year: 2009

  17. SERUM ANTIBODIES TO WHOLE-CELL AND RECOMBINANT ANTIGENS OF BORRELIA BURGDORFERI IN COTTONTAIL RABBITS

    OpenAIRE

    Magnarelli, Louis A.; Norris, Steven J; Fikrig, Erol

    2012-01-01

    Archived serum samples, from 95 eastern cottontail rabbits (Sylvilagus floridanus) captured in New York, New York, USA and Millbrook, New York, USA, during 1985–86, were analyzed in solid-phase enzyme-linked immunosorbent assays (ELISA) for total and class-specific immunoglobulin (Ig) M antibodies to whole-cell or recombinant antigens of Borrelia burgdorferi sensu stricto. Using a polyvalent conjugate, rabbit sera contained antibodies to whole-cell and recombinant antigens (protein [p]35, p37...

  18. First Isolation and Cultivation of Borrelia burgdorferi Sensu Lato from Missouri

    OpenAIRE

    Oliver, J H; Kollars, T. M.; Chandler, F W; James, A. M.; Masters, E. J.; Lane, R S; Huey, L. O.

    1998-01-01

    Five Borrelia burgdorferi sensu lato isolates from Missouri are described. This represents the first report and characterization of such isolates from that state. The isolates were obtained from either Ixodes dentatus or Amblyomma americanum ticks that had been feeding on cottontail rabbits (Sylvilagus floridanus) from a farm in Bollinger County, Mo., where a human case of Lyme disease had been reported. All isolates were screened immunologically by indirect immunofluorescence by using monocl...

  19. Molecular Typing of Borrelia burgdorferi Sensu Lato: Taxonomic, Epidemiological, and Clinical Implications

    OpenAIRE

    Wang, Guiqing; Dam, Alje P. van; Schwartz, Ira; Dankert, Jacob

    1999-01-01

    Borrelia burgdorferi sensu lato, the spirochete that causes human Lyme borreliosis (LB), is a genetically and phenotypically divergent species. In the past several years, various molecular approaches have been developed and used to determine the phenotypic and genetic heterogeneity within the LB-related spirochetes and their potential association with distinct clinical syndromes. These methods include serotyping, multilocus enzyme electrophoresis, DNA-DNA reassociation analysis, rRNA gene res...

  20. Flagellin and outer surface proteins from Borrelia burgdorferi are not glycosylated

    OpenAIRE

    ŠTĚRBA, Ján

    2012-01-01

    Glycosylation of four proteins from Borrelia burgdorferi s.s. was investigated ? flagellins FlaA, FlaB, and outer surface proteins OspA and OspB. Glycosylation of these four proteins was not proved by any of the used techniques. However, other glycan-staining positive proteins were present in the borrelia samples. These proteins were suggested to originate in the culture medium.

  1. Genomic fingerprinting of Borrelia burgdorferi sensu lato by pulsed-field gel electrophoresis.

    OpenAIRE

    1993-01-01

    A total of 46 Borrelia burgdorferi sensu lato isolates that were isolated from patients with Lyme borreliosis and infected animals or were extracted from ticks of the genus Ixodes were analyzed. Large restriction fragment patterns obtained after cleavage of genomic DNAs with MluI were analyzed by pulsed-field gel electrophoresis (PFGE). To eliminate the contribution of plasmid DNA, only fragments greater than 70 kb were used for the analysis. The results indicated that each of the 14 B. burgd...

  2. Common Ancestry of Borrelia burgdorferi Sensu Lato Strains from North America and Europe

    OpenAIRE

    Postic, D; Ras, N. Marti; Lane, R S; Humair, P.-F.; Wittenbrink, M. M.; Baranton, G

    1999-01-01

    Ten atypical European Borrelia burgdorferi sensu lato (Borrelia spp.) strains were genetically characterized, and the diversity was compared to that encountered among related Borrelia spp. from North America. Phylogenetic analyses of a limited region of the genome and of the whole genome extend existing knowledge about borrelial diversity reported earlier in Europe and the United States. Our results accord with the evidence that North American and European strains may have a common ancestry.

  3. Anaphylactoid reaction caused by sodium ceftriaxone in two horses experimentally infected by Borrelia burgdorferi

    OpenAIRE

    Basile, Roberta Carvalho; Rivera, Gabriela Gomes; Del Rio, Lara Antoniassi; de Bonis, Talissa Camargo Mantovani; do Amaral, Gabriel Paiva Domingues; Giangrecco, Edson; Ferraz, Guilherme; Yoshinari, Natalino Hajime; Canola, Paulo Aléscio; Queiroz Neto, Antonio

    2015-01-01

    Background Lyme borreliosis is a disease transmitted by ticks to mammals, especially in horses and humans. Caused by a spirochete Borrelia burgdorferi, it can result in lameness, arthritis, carditis, dermatitis and neurological signs. Anaphylactoid reactions are severe responses caused by direct action of substances (drugs, toxins), which can pose risks to life. Still poorly documented in horses, these reactions are caused by the effects of inflammatory mediators such as histamine, kinins and...

  4. Use of an endogenous plasmid locus for stable in trans complementation in Borrelia burgdorferi.

    Science.gov (United States)

    Kasumba, Irene N; Bestor, Aaron; Tilly, Kit; Rosa, Patricia A

    2015-02-01

    Targeted mutagenesis and complementation are important tools for studying genes of unknown function in the Lyme disease spirochete Borrelia burgdorferi. A standard method of complementation is reintroduction of a wild-type copy of the targeted gene on a shuttle vector. However, shuttle vectors are present at higher copy numbers than B. burgdorferi plasmids and are potentially unstable in the absence of selection, thereby complicating analyses in the mouse-tick infectious cycle. B. burgdorferi has over 20 plasmids, with some, such as linear plasmid 25 (lp25), carrying genes required by the spirochete in vivo but relatively unstable during in vitro cultivation. We propose that complementation on an endogenous plasmid such as lp25 would overcome the copy number and in vivo stability issues of shuttle vectors. In addition, insertion of a selectable marker on lp25 could ensure its stable maintenance by spirochetes in culture. Here, we describe the construction of a multipurpose allelic-exchange vector containing a multiple-cloning site and either of two selectable markers. This suicide vector directs insertion of the complementing gene into the bbe02 locus, a site on lp25 that was previously shown to be nonessential during both in vitro and in vivo growth. We demonstrate the functional utility of this strategy by restoring infectivity to an ospC mutant through complementation at this site on lp25 and stable maintenance of the ospC gene throughout mouse infection. We conclude that this represents a convenient and widely applicable method for stable gene complementation in B. burgdorferi. PMID:25452278

  5. Acquisition of Coinfection and Simultaneous Transmission of Borrelia burgdorferi and Ehrlichia phagocytophila by Ixodes scapularis Ticks

    OpenAIRE

    Michael L Levin; Fish, Durland

    2000-01-01

    The agents of Lyme disease (Borrelia burgdorferi) and human granulocytic ehrlichiosis (Ehrlichia phagocytophila) are both transmitted by the tick Ixodes scapularis. In nature, ticks are often infected with both agents simultaneously. We studied whether previous infection with either Borrelia or Ehrlichia in ticks would affect acquisition and transmission of a second pathogen. Ehrlichia-infected I. scapularis nymphs were fed upon Borrelia-infected mice, and Borrelia-infected I. scapularis nymp...

  6. Probable late lyme disease: a variant manifestation of untreated Borrelia burgdorferi infection

    OpenAIRE

    Aucott John N; Seifter Ari; Rebman Alison W

    2012-01-01

    Abstract Background Lyme disease, a bacterial infection with the tick-borne spirochete Borrelia burgdorferi, can cause early and late manifestations. The category of probable Lyme disease was recently added to the CDC surveillance case definition to describe patients with serologic evidence of exposure and physician-diagnosed disease in the absence of objective signs. We present a retrospective case series of 13 untreated patients with persistent symptoms of greater than 12 weeks duration who...

  7. Uncoordinated phylogeography of Borrelia burgdorferi and its tick vector, Ixodes scapularis

    OpenAIRE

    Humphrey, Parris T; Caporale, Diane A.; Brisson, Dustin

    2010-01-01

    Vector-borne microbes necessarily co-occur with their hosts and vectors, but the degree to which they share common evolutionary or biogeographic histories remains unexplored. We examine the congruity of the evolutionary and biogeographic histories of the Lyme disease system, the most prevalent vector-borne disease in North America. In the Eastern and Midwestern US, Ixodes scapularis ticks are the primary vectors of Borrelia burgdorferi, the bacterium that causes Lyme disease. Our phylogeograp...

  8. Identification of new drug candidates against Borrelia burgdorferi using high-throughput screening.

    Science.gov (United States)

    Pothineni, Venkata Raveendra; Wagh, Dhananjay; Babar, Mustafeez Mujtaba; Inayathullah, Mohammed; Solow-Cordero, David; Kim, Kwang-Min; Samineni, Aneesh V; Parekh, Mansi B; Tayebi, Lobat; Rajadas, Jayakumar

    2016-01-01

    Lyme disease is the most common zoonotic bacterial disease in North America. It is estimated that >300,000 cases per annum are reported in USA alone. A total of 10%-20% of patients who have been treated with antibiotic therapy report the recrudescence of symptoms, such as muscle and joint pain, psychosocial and cognitive difficulties, and generalized fatigue. This condition is referred to as posttreatment Lyme disease syndrome. While there is no evidence for the presence of viable infectious organisms in individuals with posttreatment Lyme disease syndrome, some researchers found surviving Borrelia burgdorferi population in rodents and primates even after antibiotic treatment. Although such observations need more ratification, there is unmet need for developing the therapeutic agents that focus on removing the persisting bacterial form of B. burgdorferi in rodent and nonhuman primates. For this purpose, high-throughput screening was done using BacTiter-Glo assay for four compound libraries to identify candidates that stop the growth of B. burgdorferi in vitro. The four chemical libraries containing 4,366 compounds (80% Food and Drug Administration [FDA] approved) that were screened are Library of Pharmacologically Active Compounds (LOPAC1280), the National Institutes of Health Clinical Collection, the Microsource Spectrum, and the Biomol FDA. We subsequently identified 150 unique compounds, which inhibited >90% of B. burgdorferi growth at a concentration of <25 µM. These 150 unique compounds comprise many safe antibiotics, chemical compounds, and also small molecules from plant sources. Of the 150 unique compounds, 101 compounds are FDA approved. We selected the top 20 FDA-approved molecules based on safety and potency and studied their minimum inhibitory concentration and minimum bactericidal concentration. The promising safe FDA-approved candidates that show low minimum inhibitory concentration and minimum bactericidal concentration values can be chosen as lead

  9. Biochemical and immunological characterization of the surface proteins of Borrelia burgdorferi.

    OpenAIRE

    Luft, B J; Jiang, W.; Munoz, P.; Dattwyler, R J; Gorevic, P D

    1989-01-01

    The immunodominant proteins and glycoproteins of Borrelia burgdorferi were analyzed by one-dimensional (1D) and 2D gel electrophoresis. More than 100 polypeptide species could be detected on silver-stained 2D gels. Separation of sonic extracts of the organism by differential centrifugation (100,000 X g) revealed several of the major proteins to reside predominantly within the pellet fraction. The antigenicity of the individual polypeptides was determined by Western (immuno-) blot analysis wit...

  10. Mapping the major antigenic domains of the native flagellar antigen of Borrelia burgdorferi.

    OpenAIRE

    Jiang, W.; Luft, B J; Schubach, W; Dattwyler, R J; Gorevic, P D

    1992-01-01

    Purified flagellar protein (p41) of Borrelia burgdorferi (strain B31) was subjected to chemical cleavage with hydroxylamine or proteolysis with V8 protease, endoproteinase Asp-N, or alpha-chymotrypsin. The resulting polypeptides were identified by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, and their positions in the published DNA sequence of the p41 protein were determined by amino-terminal sequencing and amino acid analysis. Epitope specificities of antibody binding by a mono...

  11. BB0324 and BB0028 are constituents of the Borrelia burgdorferi β-barrel assembly machine (BAM complex

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    Lenhart Tiffany R

    2012-04-01

    Full Text Available Abstract Background Similar to Gram-negative bacteria, the outer membrane (OM of the pathogenic spirochete, Borrelia burgdorferi, contains integral OM-spanning proteins (OMPs, as well as membrane-anchored lipoproteins. Although the mechanism of OMP biogenesis is still not well-understood, recent studies have indicated that a heterooligomeric OM protein complex, known as BAM (β-barrel assembly machine is required for proper assembly of OMPs into the bacterial OM. We previously identified and characterized the essential β-barrel OMP component of this complex in B. burgdorferi, which we determined to be a functional BamA ortholog. Results In the current study, we report on the identification of two additional protein components of the B. burgdorferi BAM complex, which were identified as putative lipoproteins encoded by ORFs BB0324 and BB0028. Biochemical assays with a BamA-depleted B. burgdorferi strain indicate that BB0324 and BB0028 do not readily interact with the BAM complex without the presence of BamA, suggesting that the individual B. burgdorferi BAM components may associate only when forming a functional BAM complex. Cellular localization assays indicate that BB0324 and BB0028 are OM-associated subsurface lipoproteins, and in silico analyses indicate that BB0324 is a putative BamD ortholog. Conclusions The combined data suggest that the BAM complex of B. burgdorferi contains unique protein constituents which differ from those found in other proteobacterial BAM complexes. The novel findings now allow for the B. burgdorferi BAM complex to be further studied as a model system to better our understanding of spirochetal OM biogenesis in general.

  12. Large scale spatial risk and comparative prevalence of Borrelia miyamotoi and Borrelia burgdorferi sensu lato in Ixodes pacificus.

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    Kerry Padgett

    Full Text Available Borrelia miyamotoi is a newly described emerging pathogen transmitted to people by Ixodes species ticks and found in temperate regions of North America, Europe, and Asia. There is limited understanding of large scale entomological risk patterns of B. miyamotoi and of Borreila burgdorferi sensu stricto (ss, the agent of Lyme disease, in western North America. In this study, B. miyamotoi, a relapsing fever spirochete, was detected in adult (n=70 and nymphal (n=36 Ixodes pacificus ticks collected from 24 of 48 California counties that were surveyed over a 13 year period. Statewide prevalence of B. burgdorferi sensu lato (sl, which includes B. burgdorferi ss, and B. miyamotoi were similar in adult I. pacificus (0.6% and 0.8%, respectively. In contrast, the prevalence of B. burgdorferi sl was almost 2.5 times higher than B. miyamotoi in nymphal I. pacificus (3.2% versus 1.4%. These results suggest similar risk of exposure to B. burgdorferi sl and B. miyamotoi from adult I. pacificus tick bites in California, but a higher risk of contracting B. burgdorferi sl than B. miyamotoi from nymphal tick bites. While regional risk of exposure to these two spirochetes varies, the highest risk for both species is found in north and central coastal California and the Sierra Nevada foothill region, and the lowest risk is in southern California; nevertheless, tick-bite avoidance measures should be implemented in all regions of California. This is the first study to comprehensively evaluate entomologic risk for B. miyamotoi and B. burgdorferi for both adult and nymphal I. pacificus, an important human biting tick in western North America.

  13. A possible role for inflammation in mediating apoptosis of oligodendrocytes as induced by the Lyme disease spirochete Borrelia burgdorferi

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    Ramesh Geeta

    2012-04-01

    Full Text Available Abstract Background Inflammation caused by the Lyme disease spirochete B. burgdorferi is an important factor in the pathogenesis of Lyme neuroborreliosis. Our central hypothesis is that B. burgdorferi can cause disease via the induction of inflammatory mediators such as cytokines and chemokines in glial and neuronal cells. Earlier we demonstrated that interaction of B. burgdorferi with brain parenchyma induces inflammatory mediators in glial cells as well as glial (oligodendrocyte and neuronal apoptosis using ex vivo and in vivo models of experimentation. Methods In this study we evaluated the ability of live B. burgdorferi to elicit inflammation in vitro in differentiated human MO3.13 oligodendrocytes and in differentiated primary human oligodendrocytes, by measuring the concentration of immune mediators in culture supernatants using Multiplex ELISA assays. Concomitant apoptosis was quantified in these cultures by the in situ terminal deoxynucleotidyl transferase mediated UTP nick end labeling (TUNEL assay and by quantifying active caspase-3 by flow cytometry. The above phenomena were also evaluated after 48 h of stimulation with B. burgdorferi in the presence and absence of various concentrations of the anti-inflammatory drug dexamethasone. Results B. burgdorferi induced enhanced levels of the cytokine IL-6 and the chemokines IL-8 and CCL2 in MO3.13 cells as compared to basal levels, and IL-8 and CCL2 in primary human oligodendrocytes, in a dose-dependent manner. These cultures also showed significantly elevated levels of apoptosis when compared with medium controls. Dexamethasone reduced both the levels of immune mediators and apoptosis, also in a manner that was dose dependent. Conclusions This finding supports our hypothesis that the inflammatory response elicited by the Lyme disease spirochete in glial cells contributes to neural cell damage. As oligodendrocytes are vital for the functioning and survival of neurons, the inflammation and

  14. PCR-Based quantification of Borrelia burgdorferi organisms in canine tissues over a 500-Day postinfection period.

    Science.gov (United States)

    Straubinger, R K

    2000-06-01

    Borrelia burgdorferi infection in beagle dogs was studied quantitatively with skin punch biopsy samples and blood samples collected at 4- and 2-week intervals, respectively, over a 500-day period. Thereafter, 25 tissue samples of each dog were collected for further analysis. Starting at day 120 after tick challenge, 12 dogs were treated with antibiotics (azithromycin, ceftriaxone, or doxycycline) for 30 consecutive days. Four dogs received no antibiotic therapy. Quantification of B. burgdorferi DNA was done with an ABI Prism 7700 Sequence Detection System with oligonucleotide primers and a fluorescence-labeled probe designed to specifically amplify a fragment of the ospA gene of B. burgdorferi strain N40. All 16 dogs became infected with B. burgdorferi after tick challenge. In skin biopsy samples, spirochete numbers peaked at day 60 postinfection (dogs, and decreased to almost undetectable levels during the following 6 months. The number of B. burgdorferi organisms detected in skin biopsy samples was inversely correlated with the antibody levels measured by enzyme-linked immunosorbent assay. Antibiotic treatment reduced the amount of detectable spirochete DNA in skin tissue by a factor of 1,000 or more. At the end of the experiment, B. burgdorferi DNA was detectable at low levels (10(2) to 10(4) organisms per 100 microgram of extracted DNA) in multiple tissue samples regardless of treatment. However, more tissue samples of untreated dogs than of antibiotic-treated dogs were positive, and tissue samples of untreated dogs also were positive by culture. Only 1.6% of 576 blood samples of all dogs were positive for B. burgdorferi by PCR. PMID:10834975

  15. Functional analysis of the Borrelia burgdorferi bba64 gene product in murine infection via tick infestation.

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    Toni G Patton

    Full Text Available Borrelia burgdorferi, the causative agent of Lyme borreliosis, is transmitted to humans from the bite of Ixodes spp. ticks. During the borrelial tick-to-mammal life cycle, B. burgdorferi must adapt to many environmental changes by regulating several genes, including bba64. Our laboratory recently demonstrated that the bba64 gene product is necessary for mouse infectivity when B. burgdorferi is transmitted by an infected tick bite, but not via needle inoculation. In this study we investigated the phenotypic properties of a bba64 mutant strain, including 1 replication during tick engorgement, 2 migration into the nymphal salivary glands, 3 host transmission, and 4 susceptibility to the MyD88-dependent innate immune response. Results revealed that the bba64 mutant's attenuated infectivity by tick bite was not due to a growth defect inside an actively feeding nymphal tick, or failure to invade the salivary glands. These findings suggested there was either a lack of spirochete transmission to the host dermis or increased susceptibility to the host's innate immune response. Further experiments showed the bba64 mutant was not culturable from mouse skin taken at the nymphal bite site and was unable to establish infection in MyD88-deficient mice via tick infestation. Collectively, the results of this study indicate that BBA64 functions at the salivary gland-to-host delivery interface of vector transmission and is not involved in resistance to MyD88-mediated innate immunity.

  16. Seroprevalence of Leptospira spp. and Borrelia burgdorferi sensu lato in Italian horses.

    Science.gov (United States)

    Ebani, Valentina V; Bertelloni, Fabrizio; Pinzauti, Paolo; Cerri, Domenico

    2012-01-01

    The aim of the study was to determine the seroprevalence of Leptospira spp. and Borrelia burgdorferi sensu lato in healthy horses living in 7 provinces of central Italy. In the period 2007-2009, sera from 386 horses were tested by microagglutination test (MAT) to detect antibodies to Leptospira spp., employing the following serovars as antigens: Bratislava, Ballum, Canicola, Icterohaemorrhagiae, Grippotyphosa, Hardjo, Pomona, Tarassovi. 3 animals were positive for the serovars Icterohaemorrhagiae, 2 to Bratislava, and 1 to Pomona, for a total 1.5% seroprevalence. All sera were examined by immunofluorence antibody test (IFAT) to reveal anti-B. burgdorferi s.l. antibodies. 94 (24.3%) horses were positive with antibody titres ranging from 1:64 to 1:1,024. The seroprevalence was significantly higher in >10 year-old horses compared to younger subjects. No significant differences in the mean seroprevalence were observed in the respective years. The total mean seroprevalence were strictly related to the environmental conditions of the areas in which the horses lived. No cross-reactions between Leptospira and Borrelia were observed. This is the first serological survey on antibodies to B. burgdorferi s.l. in Italian horses. PMID:22742794

  17. The BBA33 lipoprotein binds collagen and impacts Borrelia burgdorferi pathogenesis

    Science.gov (United States)

    Zhi, Hui; Weening, Eric H.; Barbu, Elena Magda; Hyde, Jenny A.; Höök, Magnus; Skare, Jon T.

    2016-01-01

    Summary Borrelia burgdorferi , the etiologic agent of Lyme disease, adapts to the mammalian hosts by differentially expressing several genes in the BosR and Rrp2-RpoN-RpoS dependent pathways, resulting in a distinct protein profile relative to that seen for survival in the Ixodes spp. tick. Previous studies indicate that a putative lipoprotein, BBA33, is produced in an RpoS-dependent manner under conditions that mimic the mammalian component of the borrelial lifecycle. However, the significance and function for BBA33 is not known. Given its linkage to the BosR/Rrp2-RpoN-RpoS regulatory cascade, we hypothesized that BBA33 facilitates B. burgdorferi infection in the mammalian host. The deletion of bba33 eliminated B. burgdorferi infectivity in C3H mice, which was rescued by genetic complementation with intact bba33. With regard to function, a combinatorial peptide approach, coupled with subsequent in vitro binding assays, indicated that BBA33 binds to collagen type VI and, to a lesser extent, collagen type IV. Whole cell binding assays demonstrated BBA33-dependent binding to human collagen type VI. Taken together, these results suggest that BBA33 interacts with collagenous structures and may function as an adhesin in a process that is required to prevent bacterial clearance. PMID:25560615

  18. Lyme disease and the detection of Borrelia burgdorferi genospecies in Ixodes ricinus ticks from central Italy

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    Ilaria Pascucci

    2010-06-01

    Full Text Available The Province of Pesaro-Urbino, situated in the Marche Region of central Italy, can be considered to be an area at risk for Lyme disease because of its ecological features. Field data are not yet available although the disease is known to be present in neighbouring areas. During a field study lasting twelve months, ticks were collected from the vegetation, from wild cervids and also from humans who reported a tick bite at the local hospital. All ticks were identified and Ixodes ricinus specimens were tested using three different polymerase chain reaction tests for the detection of Borrelia burgdorferi sensu lato (sl. To identify the genospecies of B. burgdorferi sl, a fragment of the 5S-23S ribosomal rRNA intergenic spacer of the positive samples was amplified and then sequenced. Sequencing of the 5S-23S intergenic spacer led to the identification of two different genospecies, namely: B. burgdorferi sensu stricto and B. lusitaniae, both of which are involved in cases of human infection. Findings on the host-tick relationships and on the genospecies involved in the cycle of borreliosis confirm the suitable conditions for Lyme disease in the study area. The results concur with previous findings reported in the Mediterranean region.

  19. Positive IgG Western Blot for Borrelia burgdorferi in Colombia

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    Palacios Ricardo

    1999-01-01

    Full Text Available In order to evaluate the presence of specific IgG antibodies to Borrelia burgdorferi in patients with clinical manifestations associated with Lyme borreliosis in Cali, Colombia, 20 serum samples from patients with dermatologic signs, one cerebrospinal fluid (CSF sample from a patient with chronic neurologic and arthritic manifestations, and twelve serum samples from individuals without clinical signs associated with Lyme borreliosis were analyzed by IgG Western blot. The results were interpreted following the recommendations of the Centers for Diseases Control and Prevention (CDC for IgG Western blots. Four samples fulfilled the CDC criteria: two serum specimens from patients with morphea (localized scleroderma, the CSF from the patient with neurologic and arthritic manifestations, and one of the controls. Interpretation of positive serology for Lyme disease in non-endemic countries must be cautious. However these results suggest that the putative "Lyme-like" disease may correlate with positivity on Western blots, thus raising the possibility that a spirochete genospecies distinct from B. burgdorferi sensu stricto, or a Borrelia species other than B. burgdorferi sensu lato is the causative agent. Future work will focus on a survey of the local tick and rodent population for evidence of spirochete species that could be incriminated as the etiologic agent.

  20. Prevalence of Borrelia burgdorferi sensu lato in rodents from Gansu, northwestern China

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    Liu Zengjia

    2010-05-01

    Full Text Available Abstract Background Lyme disease is a multi-organ infection disease caused by Borrelia burgdorferi sensu lato. Lyme disease was first documented in north-east China in 1986. Since then more than 20 provinces in China were confirmed the existence of nature foci of Lyme disease. In the present study, a molecular epidemiological survey was conducted to investigate the presence of Borrelia burgdorferi sensu lato in rodents from Gansu Province for the first time. Result A total of 140 rodents of 7 species were examined for Borrelia burgdorferi sensu lato. by nested-PCR and culture isolation. The overall infection rate was 22.86%. Two rodent species most frequently trapped were responsible for all positive. 3 strains were isolated from Apodemus agrarius, which belonged to B. garinii, 1 strain isolated from Rattus losea was identified as B. afzelii. Conclusion The study firstly showed the role of rodents in maintaining the pathogen of Lyme disease in the environment from Gansu Province and there existed at least two genotypes of Lyme disease spirochaetes in rodents.

  1. An RND-type efflux system in Borrelia burgdorferi is involved in virulence and resistance to antimicrobial compounds.

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    Ignas Bunikis

    2008-02-01

    Full Text Available Borrelia burgdorferi is remarkable for its ability to thrive in widely different environments due to its ability to infect various organisms. In comparison to enteric Gram-negative bacteria, these spirochetes have only a few transmembrane proteins some of which are thought to play a role in solute and nutrient uptake and excretion of toxic substances. Here, we have identified an outer membrane protein, BesC, which is part of a putative export system comprising the components BesA, BesB and BesC. We show that BesC, a TolC homolog, forms channels in planar lipid bilayers and is involved in antibiotic resistance. A besC knockout was unable to establish infection in mice, signifying the importance of this outer membrane channel in the mammalian host. The biophysical properties of BesC could be explained by a model based on the channel-tunnel structure. We have also generated a structural model of the efflux apparatus showing the putative spatial orientation of BesC with respect to the AcrAB homologs BesAB. We believe that our findings will be helpful in unraveling the pathogenic mechanisms of borreliae as well as in developing novel therapeutic agents aiming to block the function of this secretion apparatus.

  2. TLR2 dependent induction of vitamin A metabolizing enzymes in dendritic cells promotes T regulatory responses and inhibits TH-17 mediated autoimmunity

    Science.gov (United States)

    Manicassamy, Santhakumar; Ravindran, Rajesh; Deng, Jiusheng; Oluoch, Herold; Denning, Timothy L; Kasturi, Sudhir Pai; Rosenthal, Kristen M.; Evavold, Brian D.; Pulendran, Bali

    2009-01-01

    Immune sensing of a microbe occurs via multiple receptors. How signals from different receptors are coordinated to yield a specific immune response is poorly understood. We demonstrate that the different pathogen recognition receptors, TLR2 and dectin-1, recognizing the same microbial stimulus, stimulate distinct innate and adaptive responses. TLR2 signaling induced splenic dendritic cells (DCs) to express the retinoic acid (RA) metabolizing enzyme Raldh2 and IL-10, and to metabolize vitamin A and stimulate Foxp3+ T regulatory cells (Treg cells). RA acted on DCs to induce Socs3 expression, which suppressed activation of p38 MAPK and pro-inflammatory cytokines. Consistent with this, TLR2 signaling induced Treg cells, and suppressed IL-23 and TH-17/ TH-1 mediated autoimmune responses in vivo. In contrast, dectin-1 signaling mostly induced IL-23 and pro-inflammatory cytokines, and augmented TH-17/ TH-1 mediated autoimmune responses in vivo. These data define a new mechanism for the systemic induction of RA and immune suppression against autoimmunity. PMID:19252500

  3. TLR2 dependent induction of vitamin A metabolizing enzymes in dendritic cells promotes T regulatory responses and inhibits TH-17 mediated autoimmunity

    OpenAIRE

    Manicassamy, Santhakumar; Ravindran, Rajesh; Deng, Jiusheng; Oluoch, Herold; Denning, Timothy L.; Kasturi, Sudhir Pai; Kristen M Rosenthal; Evavold, Brian D.; Pulendran, Bali

    2009-01-01

    Immune sensing of a microbe occurs via multiple receptors. How signals from different receptors are coordinated to yield a specific immune response is poorly understood. We demonstrate that the different pathogen recognition receptors, TLR2 and dectin-1, recognizing the same microbial stimulus, stimulate distinct innate and adaptive responses. TLR2 signaling induced splenic dendritic cells (DCs) to express the retinoic acid (RA) metabolizing enzyme Raldh2 and IL-10, and to metabolize vitamin ...

  4. Evidence that RpoS (sigmaS) in Borrelia burgdorferi is controlled directly by RpoN (sigma54/sigmaN).

    Science.gov (United States)

    Smith, Alexandra H; Blevins, Jon S; Bachlani, Gulnaz N; Yang, Xiaofeng F; Norgard, Michael V

    2007-03-01

    The alternative sigma factor (RpoN-RpoS) pathway controls the expression of key virulence factors in Borrelia burgdorferi. However, evidence to support whether RpoN controls rpoS directly or, perhaps, indirectly via a transactivator has been lacking. Herein we provide biochemical and genetic evidence that RpoN directly controls rpoS in B. burgdorferi. PMID:17158681

  5. Regulation of OspE-related, OspF-related, and Elp lipoproteins of Borrelia burgdorferi strain 297 by mammalian host-specific signals.

    Science.gov (United States)

    Hefty, P S; Jolliff, S E; Caimano, M J; Wikel, S K; Radolf, J D; Akins, D R

    2001-06-01

    In previous studies we have characterized the cp32/18 loci in Borrelia burgdorferi 297 which encode OspE and OspF orthologs and a third group of lipoproteins which possess OspE/F-like leader peptides (Elps). To further these studies, we have comprehensively analyzed their patterns of expression throughout the borrelial enzootic cycle. Serial dilution reverse transcription-PCR analysis indicated that although a shift in temperature from 23 to 37 degrees C induced transcription for all nine genes analyzed, this effect was often markedly enhanced in mammalian host-adapted organisms cultivated within dialysis membrane chambers (DMCs) implanted within the peritoneal cavities of rats. Indirect immunofluorescence assays performed on temperature-shifted, in vitro-cultivated spirochetes and organisms in the midguts of unfed and fed ticks revealed distinct expression profiles for many of the OspE-related, OspF-related, and Elp proteins. Other than BbK2.10 and ElpA1, all were expressed by temperature-shifted organisms, while only OspE, ElpB1, OspF, and BbK2.11 were expressed in the midguts of fed ticks. Additionally, although mRNA was detected for all nine lipoprotein-encoding genes, two of these proteins (BbK2.10 and ElpA1) were not expressed by spirochetes cultivated in vitro, within DMCs, or by spirochetes within tick midguts. However, the observation that B. burgdorferi-infected mice generated specific antibodies against BbK2.10 and ElpA1 indicated that these antigens are expressed only in the mammalian host and that a form of posttranscriptional regulation is involved. Analysis of the upstream regions of these genes revealed several differences between their promoter regions, the majority of which were found in the -10 and -35 hexamers and the spacer regions between them. Also, rather than undergoing simultaneous upregulation during tick feeding, these genes and the corresponding lipoproteins appear to be subject to progressive recruitment or enhancement of expression as

  6. CD14 cooperates with complement receptor 3 to mediate MyD88-independent phagocytosis of Borrelia burgdorferi

    Science.gov (United States)

    Hawley, Kelly L.; Olson, Chris M.; Iglesias-Pedraz, Juan M.; Navasa, Nicolás; Cervantes, Jorge L.; Caimano, Melissa J.; Izadi, Hooman; Ingalls, Robin R.; Pal, Utpal; Salazar, Juan C.; Radolf, Justin D.; Anguita, Juan

    2012-01-01

    Phagocytosis of Borrelia burgdorferi, the causative agent of Lyme disease, is a poorly understood process, despite its importance during the host immune response to infection. B. burgdorferi has been shown to bind to different receptors on the surface of phagocytic cells, including the β2 integrin, complement receptor 3 (CR3). However, whether these receptors mediate the phagocytosis of the spirochete remains unknown. We now demonstrate that CR3 mediates the phagocytosis of the spirochete by murine macrophages and human monocytes. Interaction of B. burgdorferi with the integrin is not sufficient, however, to internalize the spirochete; phagocytosis requires the interaction of CR3 with the GPI-anchored protein, CD14, independently of TLR/MyD88-induced or inside-out signals. Interestingly, the absence of CR3 leads to marked increases in the production of TNF in vitro and in vivo, despite reduced spirochetal uptake. Furthermore, the absence of CR3 during infection with B. burgdorferi results in the inefficient control of bacterial burdens in the heart and increased Lyme carditis. Overall, our data identify CR3 as a MyD88-independent phagocytic receptor for B. burgdorferi that also participates in the modulation of the proinflammatory output of macrophages. These data also establish a unique mechanism of CR3-mediated phagocytosis that requires the direct cooperation of GPI-anchored proteins. PMID:22232682

  7. The multifaceted responses of primary human astrocytes and brain microvascular endothelial cells to the Lyme disease spirochete, Borrelia burgdorferi

    Directory of Open Access Journals (Sweden)

    Catherine A. Brissette

    2013-08-01

    Full Text Available The vector-borne pathogen, Borrelia burgdorferi, causes a multi-system disorder including neurological complications. These neurological disorders, collectively termed neuroborreliosis, can occur in up to 15% of untreated patients. The neurological symptoms are probably a result of a glial-driven, host inflammatory response to the bacterium. However, the specific contributions of individual glial and other support cell types to the pathogenesis of neuroborreliosis are relatively unexplored. The goal of this project was to characterize specific astrocyte and endothelial cell responses to B. burgdorferi. Primary human astrocytes and primary HBMEC (human brain microvascular endothelial cells were incubated with B. burgdorferi over a 72-h period and the transcriptional responses to the bacterium were analyzed by real-time PCR arrays. There was a robust increase in several surveyed chemokine and related genes, including IL (interleukin-8, for both primary astrocytes and HBMEC. Array results were confirmed with individual sets of PCR primers. The production of specific chemokines by both astrocytes and HBMEC in response to B. burgdorferi, including IL-8, CXCL-1, and CXCL-10, were confirmed by ELISA. These results demonstrate that primary astrocytes and HBMEC respond to virulent B. burgdorferi by producing a number of chemokines. These data suggest that infiltrating phagocytic cells, particularly neutrophils, attracted by chemokines expressed at the BBB (blood–brain barrier may be important contributors to the early inflammatory events associated with neuroborreliosis.

  8. Effectiveness of Stevia Rebaudiana Whole Leaf Extract Against the Various Morphological Forms of Borrelia Burgdorferi in Vitro.

    Science.gov (United States)

    Theophilus, P A S; Victoria, M J; Socarras, K M; Filush, K R; Gupta, K; Luecke, D F; Sapi, E

    2015-12-01

    Lyme disease is a tick-borne multisystemic disease caused by Borrelia burgdorferi. Administering antibiotics is the primary treatment for this disease; however, relapse often occurs when antibiotic treatment is discontinued. The reason for relapse remains unknown, but recent studies suggested the possibilities of the presence of antibiotic resistant Borrelia persister cells and biofilms. In this study, we evaluated the effectiveness of whole leaf Stevia extract against B. burgdorferi spirochetes, persisters, and biofilm forms in vitro. The susceptibility of the different forms was evaluated by various quantitative techniques in addition to different microscopy methods. The effectiveness of Stevia was compared to doxycycline, cefoperazone, daptomycin, and their combinations. Our results demonstrated that Stevia had significant effect in eliminating B. burgdorferi spirochetes and persisters. Subculture experiments with Stevia and antibiotics treated cells were established for 7 and 14 days yielding, no and 10% viable cells, respectively compared to the above-mentioned antibiotics and antibiotic combination. When Stevia and the three antibiotics were tested against attached biofilms, Stevia significantly reduced B. burgdorferi forms. Results from this study suggest that a natural product such as Stevia leaf extract could be considered as an effective agent against B. burgdorferi. PMID:26716015

  9. Effectiveness of Stevia Rebaudiana Whole Leaf Extract Against the Various Morphological Forms of Borrelia Burgdorferi in Vitro

    Science.gov (United States)

    Theophilus, P. A. S.; Victoria, M. J.; Socarras, K. M.; Filush, K. R.; Gupta, K.; Luecke, D. F.; Sapi, E.

    2015-01-01

    Lyme disease is a tick-borne multisystemic disease caused by Borrelia burgdorferi. Administering antibiotics is the primary treatment for this disease; however, relapse often occurs when antibiotic treatment is discontinued. The reason for relapse remains unknown, but recent studies suggested the possibilities of the presence of antibiotic resistant Borrelia persister cells and biofilms. In this study, we evaluated the effectiveness of whole leaf Stevia extract against B. burgdorferi spirochetes, persisters, and biofilm forms in vitro. The susceptibility of the different forms was evaluated by various quantitative techniques in addition to different microscopy methods. The effectiveness of Stevia was compared to doxycycline, cefoperazone, daptomycin, and their combinations. Our results demonstrated that Stevia had significant effect in eliminating B. burgdorferi spirochetes and persisters. Subculture experiments with Stevia and antibiotics treated cells were established for 7 and 14 days yielding, no and 10% viable cells, respectively compared to the above-mentioned antibiotics and antibiotic combination. When Stevia and the three antibiotics were tested against attached biofilms, Stevia significantly reduced B. burgdorferi forms. Results from this study suggest that a natural product such as Stevia leaf extract could be considered as an effective agent against B. burgdorferi. PMID:26716015

  10. An invasive mammal (the gray squirrel, Sciurus carolinensis) commonly hosts diverse and atypical genotypes of the zoonotic pathogen Borrelia burgdorferi sensu lato

    DEFF Research Database (Denmark)

    Millins, Caroline; Magierecka, Agnieszka; Gilbert, Lucy;

    2015-01-01

    Invasive vertebrate species can act as hosts for endemic pathogens and may alter pathogen community composition and dynamics. For the zoonotic pathogen Borrelia burgdorferi sensu lato, the agent of Lyme borreliosis, recent work shows invasive rodent species can be of high epidemiological importance...... and may support host specific strains. This study examined the role of grey squirrels (Sciurus carolinensis), (n=679), an invasive species in the United Kingdom (UK), as B. burgdorferi s.l. hosts. We found that grey squirrels were frequently infested with Ixodes ricinus, the main vector of B. burgdorferi...... in squirrels infested with ticks. Invasive grey squirrels appear to become infected with locally circulating strains of B. burgdorferi s.l., further studies are required to determine their role in community disease dynamics. Our findings highlight that the role of introduced host species in B. burgdorferi s...

  11. Detection of Borrelia burgdorferi sensu stricto and Borrelia garinii DNAs in patient with Hyperkeratosis lenticularis perstans (Flegel disease).

    Science.gov (United States)

    Schwarzova, Katarina; Kozub, Peter; Szep, Zoltan; Golovchenko, Marina; Rudenko, Natasha

    2016-09-01

    Determination of the causative agent of erythema-like skin lesions in case of nonspecific superficial perivascular dermatitis was supported by histological examination and led to the latter diagnosis of Hyperkeratosis lenticularis perstans (Flegel disease) in patient. The presence of antibodies against Borrelia burgdorferi in patient serum was confirmed by a routine ELISA method and verified by Western blot technique. Skin biopsy and blood specimens were analyzed by PCR and multilocus sequence analysis (MLSA). Western blot method revealed IgG antibody response against two specific antigens, 17 and 83 kDa proteins. The recombinant test detected IgG antibody response against p100 and p41 antigens. The sequence analysis of amplicons from the selected genomic loci obtained from skin biopsy and serum samples revealed the presence of two species from B. burgdorferi sensu lato complex as a co-infection in this patient-B. burgdorferi sensu stricto (s.s.) and Borrelia garinii. PMID:26769152

  12. Phenotypic and Genetic Characterization of a Novel Borrelia burgdorferi Sensu Lato Isolate from a Patient with Lyme Borreliosis

    OpenAIRE

    Wang, Guiqing; Dam, Alje P. van; Dankert, Jacob

    1999-01-01

    Borrelia burgdorferi sensu lato A14S was cultured from a skin biopsy specimen of a patient with erythema migrans in The Netherlands. This isolate had a unique DNA fingerprint pattern compared to 135 other B. burgdorferi sensu lato isolates. In this study, the isolate A14S was further characterized by protein analysis with sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and reactivity with various monoclonal antibodies. In addition, the 16S rRNA, ospA, and ospC genes, as w...

  13. Role of Acetyl-Phosphate in Activation of the Rrp2-RpoN-RpoS Pathway in Borrelia burgdorferi

    OpenAIRE

    Haijun Xu; Caimano, Melissa J.; Tao Lin; Ming He; Radolf, Justin D.; Norris, Steven J; Frank Gherardini; Wolfe, Alan J.; X Frank Yang

    2010-01-01

    Borrelia burgdorferi, the Lyme disease spirochete, dramatically alters its transcriptome and proteome as it cycles between the arthropod vector and mammalian host. During this enzootic cycle, a novel regulatory network, the Rrp2-RpoN-RpoS pathway (also known as the σ(54)-σ(S) sigma factor cascade), plays a central role in modulating the differential expression of more than 10% of all B. burgdorferi genes, including the major virulence genes ospA and ospC. However, the mechanism(s) by which th...

  14. Dual role of Fcγ receptors in host defense and disease in Borrelia burgdorferi-infected mice

    Directory of Open Access Journals (Sweden)

    Alexia Anne Belperron

    2014-06-01

    Full Text Available Arthritis in mice infected with the Lyme disease spirochete, Borrelia burgdorferi, results from the influx of innate immune cells responding to the pathogen in the joint and is influenced in part by mouse genetics. Production of inflammatory cytokines by innate immune cells in vitro is largely mediated by Toll-like receptor (TLR interaction with Borrelia lipoproteins, yet surprisingly mice deficient in TLR2 or the TLR signaling molecule MyD88 still develop arthritis comparable to that seen in wild type mice after B. burgdorferi infection. These findings suggest that other, MyD88-independent inflammatory pathways can contribute to arthritis expression. Clearance of B. burgdorferi is dependent on the production of specific antibody and phagocytosis of the organism. As Fc receptors (FcγR are important for IgG-mediated clearance of immune complexes and opsonized particles by phagocytes, we examined the role that FcγR play in host defense and disease in B. burgdorferi-infected mice. B. burgdorferi-infected mice deficient in the Fc receptor common gamma chain (FcεRγ-/- mice harbored ~10 fold more spirochetes than similarly infected wild type mice, and this was associated with a transient increase in arthritis severity. While the elevated pathogen burdens seen in B. burgdorferi-infected MyD88-/- mice were not affected by concomitant deficiency in FcγR, arthritis was reduced in FcεRγ-/-MyD88-/- mice in comparison to wild type or single knockout mice. Gene expression analysis from infected joints demonstrated that absence of both MyD88 and FcγR lowers mRNA levels of proteins involved in inflammation, including Cxcl1 (KC, Xcr1 (Gpr5, IL-1beta, and C reactive protein. Taken together, our results demonstrate a role for FcγR-mediated immunity in limiting pathogen burden and arthritis in mice during the acute phase of B. burgdorferi infection, and further suggest that this pathway contributes to the arthritis that develops in B. burgdorferi

  15. MicroRNA-146a provides feedback regulation of lyme arthritis but not carditis during infection with Borrelia burgdorferi.

    Directory of Open Access Journals (Sweden)

    Robert B Lochhead

    2014-06-01

    Full Text Available MicroRNAs have been shown to be important regulators of inflammatory and immune responses and are implicated in several immune disorders including systemic lupus erythematosus and rheumatoid arthritis, but their role in Lyme borreliosis remains unknown. We performed a microarray screen for expression of miRNAs in joint tissue from three mouse strains infected with Borrelia burgdorferi. This screen identified upregulation of miR-146a, a key negative regulator of NF-κB signaling, in all three strains, suggesting it plays an important role in the in vivo response to B. burgdorferi. Infection of B6 miR-146a-/- mice with B. burgdorferi revealed a critical nonredundant role of miR-146a in modulating Lyme arthritis without compromising host immune response or heart inflammation. The impact of miR-146a was specifically localized to the joint, and did not impact lesion development or inflammation in the heart. Furthermore, B6 miR-146a-/- mice had elevated levels of NF-κB-regulated products in joint tissue and serum late in infection. Flow cytometry analysis of various lineages isolated from infected joint tissue of mice showed that myeloid cell infiltration was significantly greater in B6 miR-146a-/- mice, compared to B6, during B. burgdorferi infection. Using bone marrow-derived macrophages, we found that TRAF6, a known target of miR-146a involved in NF-κB activation, was dysregulated in resting and B. burgdorferi-stimulated B6 miR-146a-/- macrophages, and corresponded to elevated IL-1β, IL-6 and CXCL1 production. This dysregulated protein production was also observed in macrophages treated with IL-10 prior to B. burgdorferi stimulation. Peritoneal macrophages from B6 miR-146a-/- mice also showed enhanced phagocytosis of B. burgdorferi. Together, these data show that miR-146a-mediated regulation of TRAF6 and NF-κB, and downstream targets such as IL-1β, IL-6 and CXCL1, are critical for modulation of Lyme arthritis during chronic infection with B

  16. Serum antibodies to whole-cell and recombinant antigens of Borrelia burgdorferi in cottontail rabbits.

    Science.gov (United States)

    Magnarelli, Louis A; Norris, Steven J; Fikrig, Erol

    2012-01-01

    Archived serum samples, from 95 eastern cottontail rabbits (Sylvilagus floridanus) captured in New York, New York, USA and Millbrook, New York, USA, during 1985-86, were analyzed in solid-phase enzyme-linked immunosorbent assays (ELISA) for total and class-specific immunoglobulin (Ig) M antibodies to whole-cell or recombinant antigens of Borrelia burgdorferi sensu stricto. Using a polyvalent conjugate, rabbit sera contained antibodies to whole-cell and recombinant antigens (protein [p]35, p37, or VlsE) during different seasons, but there was no reactivity to outer surface protein (Osp)A or OspB. Seventy-six of the 102 sera (75%) analyzed were reactive with one or more of the antigens; 61 of the positive samples (80%) reacted to whole-cell antigens, followed by results for the p35 (58%, 44/76), VlsE (43%, 33/76), and p37 (29%, 22/ 76) antigens. Fifty-eight sera (76%) contained antibodies to the VlsE or p35 antigens with or without reactivity to whole-cell antigens. High antibody titers (≥1:2,560) recorded for 52 sera indicate robust antibody production. In analyses for IgM antibodies in an ELISA containing whole-cell antigens, there were 30 positive sera; titers ranged from 1:160 to 1:640. There was minimal cross-reactivity when rabbit antisera to Treponema pallidum or four serovars of Leptospira interrogans were screened against B. burgdorferi antigens. Based on more-specific results, VlsE and p35 antigens appear to be useful markers for detecting possible B. burgdorferi infections. PMID:22247369

  17. Genome stability of Lyme disease spirochetes: comparative genomics of Borrelia burgdorferi plasmids.

    Directory of Open Access Journals (Sweden)

    Sherwood R Casjens

    Full Text Available Lyme disease is the most common tick-borne human illness in North America. In order to understand the molecular pathogenesis, natural diversity, population structure and epizootic spread of the North American Lyme agent, Borrelia burgdorferi sensu stricto, a much better understanding of the natural diversity of its genome will be required. Towards this end we present a comparative analysis of the nucleotide sequences of the numerous plasmids of B. burgdorferi isolates B31, N40, JD1 and 297. These strains were chosen because they include the three most commonly studied laboratory strains, and because they represent different major genetic lineages and so are informative regarding the genetic diversity and evolution of this organism. A unique feature of Borrelia genomes is that they carry a large number of linear and circular plasmids, and this work shows that strains N40, JD1, 297 and B31 carry related but non-identical sets of 16, 20, 19 and 21 plasmids, respectively, that comprise 33-40% of their genomes. We deduce that there are at least 28 plasmid compatibility types among the four strains. The B. burgdorferi ∼900 Kbp linear chromosomes are evolutionarily exceptionally stable, except for a short ≤20 Kbp plasmid-like section at the right end. A few of the plasmids, including the linear lp54 and circular cp26, are also very stable. We show here that the other plasmids, especially the linear ones, are considerably more variable. Nearly all of the linear plasmids have undergone one or more substantial inter-plasmid rearrangements since their last common ancestor. In spite of these rearrangements and differences in plasmid contents, the overall gene complement of the different isolates has remained relatively constant.

  18. Genome Stability of Lyme Disease Spirochetes: Comparative Genomics of Borrelia burgdorferi Plasmids

    Energy Technology Data Exchange (ETDEWEB)

    Casjens S. R.; Dunn J.; Mongodin, E. F.; Qiu, W.-G.; Luft, B. J.; Schutzer, S. E.; Gilcrease, E. B.; Huang, W. M.; Vujadinovic, M.; Aron, J. K.; Vargas, L. C.; Freeman, S.; Radune, D.; Weidman, J. F.; Dimitrov, G. I.; Khouri, H. M.; Sosa, J. E.; Halpin, R. A.; Fraser, C. M.

    2012-03-14

    Lyme disease is the most common tick-borne human illness in North America. In order to understand the molecular pathogenesis, natural diversity, population structure and epizootic spread of the North American Lyme agent, Borrelia burgdorferi sensu stricto, a much better understanding of the natural diversity of its genome will be required. Towards this end we present a comparative analysis of the nucleotide sequences of the numerous plasmids of B. burgdorferi isolates B31, N40, JD1 and 297. These strains were chosen because they include the three most commonly studied laboratory strains, and because they represent different major genetic lineages and so are informative regarding the genetic diversity and evolution of this organism. A unique feature of Borrelia genomes is that they carry a large number of linear and circular plasmids, and this work shows that strains N40, JD1, 297 and B31 carry related but non-identical sets of 16, 20, 19 and 21 plasmids, respectively, that comprise 33-40% of their genomes. We deduce that there are at least 28 plasmid compatibility types among the four strains. The B. burgdorferi {approx}900 Kbp linear chromosomes are evolutionarily exceptionally stable, except for a short {le}20 Kbp plasmid-like section at the right end. A few of the plasmids, including the linear lp54 and circular cp26, are also very stable. We show here that the other plasmids, especially the linear ones, are considerably more variable. Nearly all of the linear plasmids have undergone one or more substantial inter-plasmid rearrangements since their last common ancestor. In spite of these rearrangements and differences in plasmid contents, the overall gene complement of the different isolates has remained relatively constant.

  19. Temperature-induced regulation of RpoS by a small RNA in Borrelia burgdorferi.

    Science.gov (United States)

    Lybecker, Meghan C; Samuels, D Scott

    2007-05-01

    The alternative sigma factor RpoS (sigma38 or sigmaS) plays a central role in the reciprocal regulation of the virulence-associated major outer surface proteins OspC and OspA in Borrelia burgdorferi, the Lyme disease spirochete. Temperature is one of the key environmental signals controlling RpoS, but the molecular mechanism by which the signal is transduced remains unknown. Herein, we identify and describe a small non-coding RNA, DsrABb, that regulates the temperature-induced increase in RpoS. A novel 5' end of the rpoS mRNA was identified and DsrABb has the potential to extensively base-pair with the upstream region of this rpoS transcript. We demonstrate that B. burgdorferi strains lacking DsrABb do not upregulate RpoS and OspC in response to an increase in temperature, but do regulate RpoS and OspC in response to changes in pH and cell density. Analyses of the rpoS and ospC steady-state mRNA levels in the dsrABb mutant indicate that DsrABb regulates RpoS post-transcriptionally. The 5' and 3' ends of DsrABb were mapped, demonstrating that at least four species exist with sizes ranging from 213 to 352 nucleotides. We hypothesize that DsrABb binds to the upstream region of the rpoS mRNA and stimulates translation by releasing the Shine-Dalgarno sequence and start site from a stable secondary structure. Therefore, we postulate that DsrABb is a molecular thermometer regulating RpoS in Borrelia burgdorferi. PMID:17501929

  20. Lyme Borreliosis: is there a preexisting (natural) variation in antimicrobial susceptibility among Borrelia burgdorferi strains?

    Science.gov (United States)

    Hodzic, Emir

    2015-01-01

    The development of antibiotics changed the world of medicine and has saved countless human and animal lives. Bacterial resistance/tolerance to antibiotics have spread silently across the world and has emerged as a major public health concern. The recent emergence of pan-resistant bacteria can overcome virtually any antibiotic and poses a major problem for their successful control. Selection for antibiotic resistance may take place where an antibiotic is present in the skin, gut, and other tissues of humans and animals and in the environment. Borrelia burgdorferi, the etiological agents of Lyme borreliosis, evades host immunity and establishes persistent infections in its mammalian hosts. The persistent infection poses a challenge to the effective antibiotic treatment, as demonstrated in various animal models. An increasingly heterogeneous subpopulation of replicatively attenuated spirochetes arises following treatment, and these persistent antimicrobial tolerant/resistant spirochetes are non-cultivable. The non-cultivable spirochetes resurge in multiple tissues at 12 months after treatment, with B. burgdorferi-specific DNA copy levels nearly equivalent to those found in shame-treated experimental animals. These attenuated spirochetes remain viable, but divide slowly, thereby being tolerant to antibiotics. Despite the continued non-cultivable state, RNA transcription of multiple B. burgdorferi genes was detected in host tissues, spirochetes were acquired by xenodiagnostic ticks, and spirochetal forms could be visualized within ticks and mouse tissues. A number of host cytokines were up- or down-regulated in tissues of both shame- and antibiotic-treated mice in the absence of histopathology, indicating a lack of host response to the presence of antimicrobial tolerant/resistant spirochetes. PMID:26295288

  1. Identification of Additional Anti-Persister Activity against Borrelia burgdorferi from an FDA Drug Library.

    Science.gov (United States)

    Feng, Jie; Weitner, Megan; Shi, Wanliang; Zhang, Shuo; Sullivan, David; Zhang, Ying

    2015-01-01

    Lyme disease is a leading vector-borne disease in the United States. Although the majority of Lyme patients can be cured with standard 2-4 week antibiotic treatment, 10%-20% of patients continue to suffer from prolonged post-treatment Lyme disease syndrome (PTLDS). While the cause for this is unclear, persisting organisms not killed by current Lyme antibiotics may be involved. In our previous study, we screened an FDA drug library and reported 27 top hits that showed high activity against Borrelia persisters. In this study, we present the results of an additional 113 active hits that have higher activity against the stationary phase B. burgdorferi than the currently used Lyme antibiotics. Many antimicrobial agents (antibiotics, antivirals, antifungals, anthelmintics or antiparasitics) used for treating other infections were found to have better activity than the current Lyme antibiotics. These include antibacterials such as rifamycins (3-formal-rifamycin, rifaximin, rifamycin SV), thiostrepton, quinolone drugs (sarafloxacin, clinafloxacin, tosufloxacin), and cell wall inhibitors carbenicillin, tazobactam, aztreonam; antifungal agents such as fluconazole, mepartricin, bifonazole, climbazole, oxiconazole, nystatin; antiviral agents zanamivir, nevirapine, tilorone; antimalarial agents artemisinin, methylene blue, and quidaldine blue; antihelmintic and antiparasitic agents toltrazuril, tartar emetic, potassium antimonyl tartrate trihydrate, oxantel, closantel, hycanthone, pyrimethamine, and tetramisole. Interestingly, drugs used for treating other non-infectious conditions including verteporfin, oltipraz, pyroglutamic acid, pidolic acid, and dextrorphan tartrate, that act on the glutathione/γ-glutamyl pathway involved in protection against free radical damage, and also the antidepressant drug indatraline, were found to have high activity against stationary phase B. burgdorferi. Among the active hits, agents that affect cell membranes, energy production, and reactive

  2. Identification of Additional Anti-Persister Activity against Borrelia burgdorferi from an FDA Drug Library

    Directory of Open Access Journals (Sweden)

    Jie Feng

    2015-09-01

    Full Text Available Lyme disease is a leading vector-borne disease in the United States. Although the majority of Lyme patients can be cured with standard 2–4 week antibiotic treatment, 10%–20% of patients continue to suffer from prolonged post-treatment Lyme disease syndrome (PTLDS. While the cause for this is unclear, persisting organisms not killed by current Lyme antibiotics may be involved. In our previous study, we screened an FDA drug library and reported 27 top hits that showed high activity against Borrelia persisters. In this study, we present the results of an additional 113 active hits that have higher activity against the stationary phase B. burgdorferi than the currently used Lyme antibiotics. Many antimicrobial agents (antibiotics, antivirals, antifungals, anthelmintics or antiparasitics used for treating other infections were found to have better activity than the current Lyme antibiotics. These include antibacterials such as rifamycins (3-formal-rifamycin, rifaximin, rifamycin SV, thiostrepton, quinolone drugs (sarafloxacin, clinafloxacin, tosufloxacin, and cell wall inhibitors carbenicillin, tazobactam, aztreonam; antifungal agents such as fluconazole, mepartricin, bifonazole, climbazole, oxiconazole, nystatin; antiviral agents zanamivir, nevirapine, tilorone; antimalarial agents artemisinin, methylene blue, and quidaldine blue; antihelmintic and antiparasitic agents toltrazuril, tartar emetic, potassium antimonyl tartrate trihydrate, oxantel, closantel, hycanthone, pyrimethamine, and tetramisole. Interestingly, drugs used for treating other non-infectious conditions including verteporfin, oltipraz, pyroglutamic acid, pidolic acid, and dextrorphan tartrate, that act on the glutathione/γ-glutamyl pathway involved in protection against free radical damage, and also the antidepressant drug indatraline, were found to have high activity against stationary phase B. burgdorferi. Among the active hits, agents that affect cell membranes, energy

  3. In Vitro Activities of the Everninomicin SCH 27899 and Other Newer Antimicrobial Agents against Borrelia burgdorferi

    OpenAIRE

    Lisa L. Dever; Torigian, Christine V.; Barbour, Alan G.

    1999-01-01

    The in vitro activity of the everninomicin antibiotic SCH 27899 against 17 isolates of Borrelia spp. was investigated. MICs ranged from 0.06 to 0.5 μg/ml. Time-kill studies with the B31 strain of B. burgdorferi demonstrated ≥3-log10-unit killing after 72 h with concentrations representing four times the MIC. The in vitro activity of four other newer antimicrobial agents, meropenem, cefepime, quinupristin-dalfopristin, and linezolid, was also tested against the B31 strain. Meropenem was the mo...

  4. Développement de Borrelia burgdorferi dans la tique Ixodes ricinus

    OpenAIRE

    Gern, Lise; Z. Zhu; Aeschlimann, André

    2011-01-01

    Nous avons étudié le développement de Borrelia burgdorferi dans son vecteur européen, la tique Ixodes ricinus, lors du repas sanguin. Nos résultats montrent que durant la phase de gorgement lente, les spirochètes présents dans l'intestin se multiplient. Chez certains individus, quelques spirochètes traversent la paroi intestinale et produisent une infection systémique de la tique. La présence de borrélies dans les conduits des glandes salivaires semblent prouver leur transmission via la saliv...

  5. Statistical analysis of the distribution of amino acids in Borrelia burgdorferi genome under different genetic codes

    Science.gov (United States)

    García, José A.; Alvarez, Samantha; Flores, Alejandro; Govezensky, Tzipe; Bobadilla, Juan R.; José, Marco V.

    2004-10-01

    The genetic code is considered to be universal. In order to test if some statistical properties of the coding bacterial genome were due to inherent properties of the genetic code, we compared the autocorrelation function, the scaling properties and the maximum entropy of the distribution of distances of amino acids in sequences obtained by translating protein-coding regions from the genome of Borrelia burgdorferi, under different genetic codes. Overall our results indicate that these properties are very stable to perturbations made by altering the genetic code. We also discuss the evolutionary likely implications of the present results.

  6. Evidencias de infección por Borrelia burgdorferi sensu lato en Cuba

    OpenAIRE

    Rodríguez González, Islay

    2012-01-01

    Se presentan los resultados de un conjunto de investigaciones realizadas con el propósito de aportar evidencias científicas sobre la presencia de la infección por Borrelia burgdorferi sensu lato en Cuba, que incluyó la evaluación de métodos microbiológicos para la detección de esta espiroqueta, la confirmación de la infección en muestras clínicas de pacientes con sospechas clínico-epidemiológicas de enfermedad de Lyme, la estimación de la seroprevalencia de anticuerpos contra este agent...

  7. A new (14th) member of Borrelia burgdorferi sensu lato complex

    Czech Academy of Sciences Publication Activity Database

    Oliver, J.; Rudenko, Natalia; Golovchenko, Maryna; Grubhoffer, Libor

    2008-01-01

    Roč. 14, S7 (2008), S110-S110. ISSN 1198-743X. [ECCMID /18./. 19.04.2008-22.04.2008, Barcelona] R&D Projects: GA ČR(CZ) GA524/06/1479; GA MŠk(CZ) LC06009 Grant ostatní: National Institutes of Health (NIH)(US) R37AI-24899; Centers for Disease Control and Prevention (CDC)(US) U50/CCU410282 Institutional research plan: CEZ:AV0Z60220518 Keywords : Borrelia burgdorferi s.l. complex * new member * multilocus sequence analysis Subject RIV: EC - Immunology

  8. In-vitro-Sensibilität von Borrelia burgdorferi sensu lato gegenüber vier Antibiotika: ein Vergleich der Genospezies Borrelia afzelii, Borrelia garinii und Borrelia burgdorferi sensu stricto

    OpenAIRE

    Sicklinger, Martin

    2006-01-01

    MICs and minimal bactericidal concentrations (MBCs) were evaluated for the four antibiotics azithromycin, amoxicillin, ceftriaxone, and doxycycline against the three main genospecies of Borrelia burgdorferi sensu lato. In MBC testing, statistically significant differences between the genospecies could be found in 7 out of 12 comparative evaluations (P < 0.05).

  9. CsrA (BB0184) Is Not Involved in Activation of the RpoN-RpoS Regulatory Pathway in Borrelia burgdorferi

    OpenAIRE

    Ouyang, Zhiming; Zhou, Jianli; Norgard, Michael V.

    2014-01-01

    Borrelia burgdorferi encodes a homologue of the bacterial carbon storage regulator A (CsrA). Recently, it was reported that CsrA contributes to B. burgdorferi infectivity and is required for the activation of the central RpoN-RpoS regulatory pathway. However, many questions concerning the function of CsrA in B. burgdorferi gene regulation remain unanswered. In particular, there are conflicting reports concerning the molecular details of how CsrA may modulate rpoS expression and, thus, how Csr...

  10. Identification of Borrelia burgdorferi genospecies isolated from Ixodes ricinus ticks in the South Moravian region of the Czech Republic

    Czech Academy of Sciences Publication Activity Database

    Bonczek, Ondřej; Žákovská, A.; Vargová, L.; Šerý, Omar

    2015-01-01

    Roč. 22, č. 4 (2015), s. 642-646. ISSN 1232-1966 Institutional support: RVO:67985904 Keywords : Borrelia burgdorferi s. I. * Borrelia spielmanii * Ixodes ricinus Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 1.126, year: 2014

  11. Decorin Binding by DbpA and B of Borrelia garinii, Borrelia afzelii, and Borrelia burgdorferi Sensu Stricto

    OpenAIRE

    Salo, Jemiina; Loimaranta, Vuokko; Lahdenne, Pekka; Viljanen, Matti K.; Hytönen, Jukka

    2011-01-01

    Background. Decorin adherence is crucial in the pathogenesis of Lyme borreliosis. Decorin-binding proteins (Dbp) A and B are the adhesins that mediate this interaction. DbpA and B of Borrelia garinii, Borrelia afzelii, and Borrelia burgdorferi sensu stricto (ss) differ in their amino acid sequence, but little attention has been paid to the potential difference in their decorin binding.

  12. Evaluation of the importance of VlsE antigenic variation for the enzootic cycle of borrelia burgdorferi

    Science.gov (United States)

    Efficient acquisition and transmission of Borrelia burgdorferi by the tick vector, and the ability to persistently infect both vector and host, are important elements for the life cycle of the Lyme disease pathogen. Previous work has provided strong evidence implicating the significance of the vls l...

  13. Isolation of live Borrelia burgdorferi sensu lato spirochaetes from patients with undefined disorders and symptoms not typical for Lyme borreliosis.

    Science.gov (United States)

    Rudenko, N; Golovchenko, M; Vancova, M; Clark, K; Grubhoffer, L; Oliver, J H

    2016-03-01

    Lyme borreliosis is a multisystem disorder with a diverse spectrum of clinical manifestations, caused by spirochaetes of the Borrelia burgdorferi sensu lato complex. It is an infectious disease that can be successfully cured by antibiotic therapy in the early stages; however, the possibility of the appearance of persistent signs and symptoms of disease following antibiotic treatment is recognized. It is known that Lyme borreliosis mimics multiple diseases that were never proven to have a spirochaete aetiology. Using complete modified Kelly-Pettenkofer medium we succeeded in cultivating live B. burgdorferi sensu lato spirochaetes from samples taken from people who suffered from undefined disorders, had symptoms not typical for Lyme borreliosis, but who had undergone antibiotic treatment due to a suspicion of having Lyme disease even though they were seronegative. We report the first recovery of live B. burgdorferi sensu stricto from residents of southeastern USA and the first successful cultivation of live Borrelia bissettii-like strain from residents of North America. Our results support the fact that B. bissettii is responsible for human Lyme borreliosis worldwide along with B. burgdorferi s.s. The involvement of new spirochaete species in Lyme borreliosis changes the understanding and recognition of clinical manifestations of this disease. PMID:26673735

  14. Seroprevalence of Borrelia burgdorferi sensu lato and tick-borne encephalitis virus in zoo animal species in the Czech Republic

    Czech Academy of Sciences Publication Activity Database

    Širmarová, J.; Tichá, L.; Golovchenko, Maryna; Salát, Jiří; Grubhoffer, L.; Rudenko, Natalia; Nowotny, N.; Růžek, Daniel

    2014-01-01

    Roč. 5, č. 5 (2014), s. 523-527. ISSN 1877-959X R&D Projects: GA ČR GAP502/11/2116 Institutional support: RVO:60077344 Keywords : Tick-borne encephalitis virus * Borrelia burgdorferi sensu lato * Lyme borreliosis * Seroprevalence * Zoo animals Subject RIV: EE - Microbiology, Virology Impact factor: 2.718, year: 2014

  15. Are the specialized bird ticks, Ixodes arboricola and I. frontalis, competent vectors for Borrelia burgdorferi sensu lato?

    NARCIS (Netherlands)

    Heylen, D.; Sprong, H.; Van Oers, K.; Fonville, M.; Matthysen, E.

    2014-01-01

    Our study tested whether two European bird-specialized ticks, Ixodes arboricola and I. frontalis, can act as vectors in the transmission cycles of Borrelia burgdorferi s.l. The ticks have contrasting ecologies but share songbird hosts (such as the great tit, Parus major) with the generalist I. ricin

  16. Are the specialized bird ticks, Ixodes arboricola and I. frontalis, competent vectors for Borrelia burgdorferi sensu lato?

    NARCIS (Netherlands)

    Heylen, D.; Sprong, H.; Oers, van K.; Fonville, M.; Leirs, H.; Matthysen, E.

    2014-01-01

    Our study tested whether two European bird-specialized ticks, Ixodes arboricola and I. frontalis, can act as vectors in the transmission cycles of Borrelia burgdorferi s.l. The ticks have contrasting ecologies but share songbird hosts (such as the great tit, Parus major) with the generalist I. ricin

  17. Polysynovitis in a horse due to [i]Borrelia burgdorferi[/i] sensu lato infection – Case study

    Directory of Open Access Journals (Sweden)

    Fabrizio Passamonti

    2015-05-01

    Full Text Available Lyme borreliosis (LB is a multi-systemic tick-borne disease affecting both humans and animals, including horses, and is caused by a group of interrelated spirochetes classified within the[i] Borrelia burgdorferi [/i]sensu lato (s.l. complex. Despite the high reported seroprevalence in the European equine population for [i]B. burgdorferi[/i] s.l., to-date no documented clinical cases have been described. A 6-year-old Paint gelding was referred with a history of three weeks of fever, intermittent lameness and digital flexor tendon sheath effusion of the right hind limb. Based on a strict diagnostic protocol, which included serological tests for infectious diseases and molecular investigations, a final diagnosis was made of polysynovitis due to [i]B. burgdorferi [/i]s.l. infection. An unreported aspect observed in this case was the absence of the pathogen DNA in two of the affected joints. To the authors’ knowledge, the case described represents the first documented clinical case of equine LB in Italy. Moreover, the absence of pathogen DNA in two of the affected joints observed in this case revealed a possible similarity with the same condition described in humans, where an immunomediated pathogenesis for arthropathy due to [i]B. burgdorferi[/i] s.l. infection is suspected. Since humans and horses share the same habitat, this report supports the role of the horse as potential sentinel for human biological risk.

  18. A Seventeen-Year Epidemiological Surveillance Study of Borrelia burgdorferi Infections in Two Provinces of Northern Spain

    Directory of Open Access Journals (Sweden)

    Lourdes Lledó

    2014-01-01

    Full Text Available This paper reports a 17-year seroepidemiological surveillance study of Borrelia burgdorferi infection, performed with the aim of improving our knowledge of the epidemiology of this pathogen. Serum samples (1,179 from patients (623, stratified with respect to age, sex, season, area of residence and occupation bitten by ticks in two regions of northern Spain were IFA-tested for B. burgdorferi antibodies. Positive results were confirmed by western blotting. Antibodies specific for B. burgdorferi were found in 13.3% of the patients; 7.8% were IgM positive, 9.6% were IgG positive, and 4.33% were both IgM and IgG positive. Five species of ticks were identified in the seropositive patients: Dermacentor marginatus (41.17% of such patients Dermacentor reticulatus (11.76%, Rhiphicephalus sanguineus (17.64%, Rhiphicephalus turanicus (5.88% and Ixodes ricinus (23.52%. B. burgdorferi DNA was sought by PCR in ticks when available. One tick, a D. reticulatus male, was found carrying the pathogen. The seroprevalence found was similar to the previously demonstrated in similar studies in Spain and other European countries.

  19. NMR structure of an acyl-carrier protein from Borrelia burgdorferi

    International Nuclear Information System (INIS)

    The high-resolution NMR structure of the acyl-carrier protein from the pathogen B. burgdorferi determined to a r.m.s. deviation of 0.4 Å over the protein backbone is reported. The NMR structure was determined using multidimensional NMR spectroscopy and consists of four α-helices and two 310-helices. Structural comparison reveals that this protein is highly similar to the acyl-carrier protein from A. aeolicus. Nearly complete resonance assignment and the high-resolution NMR structure of the acyl-carrier protein from Borrelia burgdorferi, a target of the Seattle Structural Genomics Center for Infectious Disease (SSGCID) structure-determination pipeline, are reported. This protein was chosen as a potential target for drug-discovery efforts because of its involvement in fatty-acid biosynthesis, an essential metabolic pathway, in bacteria. It was possible to assign >98% of backbone resonances and >92% of side-chain resonances using multidimensional NMR spectroscopy. The NMR structure was determined to a backbone r.m.s.d. of 0.4 Å and contained four α-helices and two 310-helices. A structure-homology search revealed that this protein is highly similar to the acyl-carrier protein from Aquifex aeolicus

  20. Bird-feeding ticks transstadially transmit Borrelia burgdorferi that infect Syrian hamsters.

    Science.gov (United States)

    Anderson, J F; Magnarelli, L A; Stafford, K C

    1990-01-01

    Bird-feeding Ixodes dammini ticks were documented for the first time to successfully molt and transstadially pass Borrelia burgdorferi spirochetes that were indistinguishable by sodium dodecyl sulfate-polyacrylamide gel electrophoresis from the type B31 strain. Forty-six of 73 blood-engorged larvae and 50 of 66 fully-fed nymphs, removed from wild-caught birds, successfully molted. Borreliae were isolated from 21 of 78 partially- and fully-fed larvae off birds, including six specimens that molted. Spirochete-positive cultures also were obtained from 35 of 60 partially- and fully-fed nymphs that had fed from birds, including 20 nymphs that molted into adult ticks. Transstadially passed borreliae by bird-feeding larval and nymphal I. dammini were infectious to hamsters, leading us to suggest that these ticks are capable of subsequently transmitting infectious spirochetes to mammals, including humans. An isolated of B. burgdorferi, recovered from a bird-feeding larval Ixodes dentatus, was indistinguishable by sodium dodecyl sulfate-polyacrylamide gel electrophoresis from the B31 strain. This isolate, unlike another from I. dentatus off a cottontail rabbit (Sylvilagus floridanus), had a protein band with a molecular weight of approximately 31,000 that reacted with murine monoclonal antibodies H3TS and H5332 in western blot analysis. Thus, closely related borreliae are present in both I. dentatus and I. dammini. PMID:2304189

  1. Cardiac Tropism of Borrelia burgdorferi: An Autopsy Study of Sudden Cardiac Death Associated with Lyme Carditis.

    Science.gov (United States)

    Muehlenbachs, Atis; Bollweg, Brigid C; Schulz, Thadeus J; Forrester, Joseph D; DeLeon Carnes, Marlene; Molins, Claudia; Ray, Gregory S; Cummings, Peter M; Ritter, Jana M; Blau, Dianna M; Andrew, Thomas A; Prial, Margaret; Ng, Dianna L; Prahlow, Joseph A; Sanders, Jeanine H; Shieh, Wun Ju; Paddock, Christopher D; Schriefer, Martin E; Mead, Paul; Zaki, Sherif R

    2016-05-01

    Fatal Lyme carditis caused by the spirochete Borrelia burgdorferi rarely is identified. Here, we describe the pathologic, immunohistochemical, and molecular findings of five case patients. These sudden cardiac deaths associated with Lyme carditis occurred from late summer to fall, ages ranged from young adult to late 40s, and four patients were men. Autopsy tissue samples were evaluated by light microscopy, Warthin-Starry stain, immunohistochemistry, and PCR for B. burgdorferi, and immunohistochemistry for complement components C4d and C9, CD3, CD79a, and decorin. Post-mortem blood was tested by serology. Interstitial lymphocytic pancarditis in a relatively characteristic road map distribution was present in all cases. Cardiomyocyte necrosis was minimal, T cells outnumbered B cells, plasma cells were prominent, and mild fibrosis was present. Spirochetes in the cardiac interstitium associated with collagen fibers and co-localized with decorin. Rare spirochetes were seen in the leptomeninges of two cases by immunohistochemistry. Spirochetes were not seen in other organs examined, and joint tissue was not available for evaluation. Although rare, sudden cardiac death caused by Lyme disease might be an under-recognized entity and is characterized by pancarditis and marked tropism of spirochetes for cardiac tissues. PMID:26968341

  2. Fluorescent membrane markers elucidate the association of Borrelia burgdorferi with tick cell lines.

    Science.gov (United States)

    Teixeira, R C; Baêta, B A; Ferreira, J S; Medeiros, R C; Maya-Monteiro, C M; Lara, F A; Bell-Sakyi, L; Fonseca, A H

    2016-06-20

    This study aimed to describe the association of Borrelia burgdorferi s.s. with ixodid tick cell lines by flow cytometry and fluorescence and confocal microscopy. Spirochetes were stained with a fluorescent membrane marker (PKH67 or PKH26), inoculated into 8 different tick cell lines and incubated at 30°C for 24 h. PKH efficiently stained B. burgdorferi without affecting bacterial viability or motility. Among the tick cell lines tested, the Rhipicephalus appendiculatus cell line RA243 achieved the highest percentage of association/internalization, with both high (90%) and low (10%) concentrations of BSK-H medium in tick cell culture medium. Treatment with cytochalasin D dramatically reduced the average percentage of cells with internalized spirochetes, which passed through a dramatic morphological change during their internalization by the host cell as observed in time-lapse photography. Almost all of the fluorescent bacteria were seen to be inside the tick cells. PKH labeling of borreliae proved to be a reliable and valuable tool to analyze the association of spirochetes with host cells by flow cytometry, confocal and fluorescence microscopy. PMID:27332772

  3. BORRELIA BURGDORFERI DNA IN BIOLOGICAL SAMPLES FROM PATIENTS WITH SARCOIDOSIS USING THE POLYMERASE CHAIN REACTION TECHNIQUE

    Institute of Scientific and Technical Information of China (English)

    连伟; 罗慰慈

    1995-01-01

    Polymerase chain reaction (PCR) was used to detect the presence of Borretia burgdoferi DNA in biological samples from patients with sarcoidcsis. The target DNA sequence was of chromosomal origin. The amplified DNA sequence was analyzed by agarose gel electrophoresis, PAGE with silver staining, and the identity of amplified DNA was confirmed by restriction enzyme cleavage and DNA-DNA hybridlzation with a 32P-labelled probe. The assay was sensitive to fewer than two copies of B. burgdor feri genome, even in the presence of a 104-fold excess of human eukaryotic DNA, and was also specific to different B. burgdorferl strains tested. Sera seroiogieally positive to B. burgdorferi (n=26), broncbemlveolar lavage fluid and supematant of BALF (n=26) and peripheral blood (n=9) from sarcoidosis patients were tested. The positive rate was low (4/26, 2/26, and 0/9, respectively). It was considered that DNA from B. bur gdor feri may be identified in a minority of patients with s,arcoidosis, and it may play a pathogenetic rote in such cases. More studies need to be done before advancing the hypothesis of an etiologic role of B. burgdorferi in sarcoidosis.

  4. Borrelia burgdorferi strain-specific Osp C-mediated immunity in mice.

    Science.gov (United States)

    Bockenstedt, L K; Hodzic, E; Feng, S; Bourrel, K W; de Silva, A; Montgomery, R R; Fikrig, E; Radolf, J D; Barthold, S W

    1997-11-01

    Antibodies to the outer surface proteins (Osps) A, B, and C of the spirochete Borrelia burgdorferi can prevent infection in animal models of Lyme borreliosis. We have previously demonstrated that immune serum from mice infected with B. burgdorferi N40 can also prevent challenge infection and induce disease regression in infected mice. The antigens targeted by protective and disease-modulating antibodies are presently unknown, but they do not include Osp A or Osp B. Because Osp C antibodies are present in immune mouse serum, we investigated the ability of hyperimmune serum to recombinant Osp C (N40) to protect mice against challenge infection with N40 spirochetes. In both active and passive immunization studies, Osp C (N40) antiserum failed to protect mice from challenge infection with cultured organisms. Mice actively immunized with recombinant Osp C (N40) were susceptible to tick-borne challenge infection, and nymphal ticks remained infected after feeding on Osp C-hyperimmunized mice. In contrast, similar immunization studies performed with Osp C (PKo) antiserum prevented challenge infection of mice with a clone of PKo spirochetes pathogenic for mice. Both Osp C (N40) and Osp C (PKo) antisera showed minimal in vitro borreliacidal activity, and immunofluorescence studies localized Osp C beneath the outer membrane of both N40 and PKo spirochetes. We conclude that Osp C antibody-mediated immunity is strain specific and propose that differences in Osp C surface expression by spirochetes in vivo may account for strain-specific immunity. PMID:9353047

  5. Proteomic Analysis of Lyme Disease: Global Protein Comparison of Three Strains of Borrelia burgdorferi

    Energy Technology Data Exchange (ETDEWEB)

    Jacobs, Jon M.; Yang, Xiaohua; Luft, Benjamin J.; Dunn, John J.; Camp, David G.; Smith, Richard D.

    2005-04-01

    The Borrelia burgdorferi spirochete is the causative agent of Lyme disease, the most common tick-borne disease in the United States. It has been studied extensively to help understand its pathogenicity of infection and how it can persist in different mammalian hosts. We report the proteomic analysis of the archetype B. burgdorferi B31 strain and two other strains (ND40, and JD-1) having different Borrelia pathotypes using strong cation exchange fractionation of proteolytic peptides followed by high-resolution, reversed phase capillary liquid chromatography coupled with ion trap tandem mass spectrometric (LC-MS/MS) analysis. Protein identification was facilitated by the availability of the complete B31 genome sequence. A total of 665 Borrelia proteins were identified representing ~38 % coverage of the theoretical B31 proteome. A significant overlap was observed between the identified proteins in direct comparisons between any two strains (>72%), but distinct differences were observed among identified hypothetical and outer membrane proteins of the three strains. Such a concurrent proteomic overview of three Borrelia strains based upon only the B31 genome sequence is shown to provide significant insights into the presence or absence of specific proteins and a broad overall comparison among strains.

  6. Proving lipid rafts exist: membrane domains in the prokaryote Borrelia burgdorferi have the same properties as eukaryotic lipid rafts.

    Directory of Open Access Journals (Sweden)

    Timothy J LaRocca

    Full Text Available Lipid rafts in eukaryotic cells are sphingolipid and cholesterol-rich, ordered membrane regions that have been postulated to play roles in many membrane functions, including infection. We previously demonstrated the existence of cholesterol-lipid-rich domains in membranes of the prokaryote, B. burgdorferi, the causative agent of Lyme disease [LaRocca et al. (2010 Cell Host & Microbe 8, 331-342]. Here, we show that these prokaryote membrane domains have the hallmarks of eukaryotic lipid rafts, despite lacking sphingolipids. Substitution experiments replacing cholesterol lipids with a set of sterols, ranging from strongly raft-promoting to raft-inhibiting when mixed with eukaryotic sphingolipids, showed that sterols that can support ordered domain formation are both necessary and sufficient for formation of B. burgdorferi membrane domains that can be detected by transmission electron microscopy or in living organisms by Förster resonance energy transfer (FRET. Raft-supporting sterols were also necessary and sufficient for formation of high amounts of detergent resistant membranes from B. burgdorferi. Furthermore, having saturated acyl chains was required for a biotinylated lipid to associate with the cholesterol-lipid-rich domains in B. burgdorferi, another characteristic identical to that of eukaryotic lipid rafts. Sterols supporting ordered domain formation were also necessary and sufficient to maintain B. burgdorferi membrane integrity, and thus critical to the life of the organism. These findings provide compelling evidence for the existence of lipid rafts and show that the same principles of lipid raft formation apply to prokaryotes and eukaryotes despite marked differences in their lipid compositions.

  7. Prevalence of the Lyme Disease Spirochete, Borrelia burgdorferi, in Blacklegged Ticks, Ixodes scapularis at Hamilton-Wentworth, Ontario.

    Science.gov (United States)

    Scott, John D; Anderson, John F; Durden, Lance A; Smith, Morgan L; Manord, Jodi M; Clark, Kerry L

    2016-01-01

    Lyme disease has emerged as a major health concern in Canada, where the etiological agent, Borrelia burgdorferi sensu lato (s.l.), a spirochetal bacterium, is typically spread by the bite of certain ticks. This study explores the presence of B. burgdorferi s.l. in blacklegged ticks, Ixodes scapularis, collected at Dundas, Ontario (a locality within the region of Hamilton-Wentworth). Using passive surveillance, veterinarians and pet groomers were asked to collect blacklegged ticks from dogs and cats with no history of travel. Additionally, I. scapularis specimens were submitted from local residents and collected by flagging. Overall, 12 (41%) of 29 blacklegged ticks were infected with B. burgdorferi s.l. Using polymerase chain reaction (PCR) and DNA sequencing, two borrelial amplicons were characterized as B. burgdorferi sensu stricto (s.s.), a genospecies pathogenic to humans and certain domestic animals. Notably, three different vertebrate hosts each had two engorged I. scapularis females removed on the same day and, likewise, one cat had three repeat occurrences of this tick species. These multiple infestations suggest that a population of I. scapularis may be established in this area. The local public health unit has been underreporting the presence of B. burgdorferi s.l.-infected I. scapularis in the area encompassing Dundas. Our findings raise concerns about the need to erect tick warning signs in parkland areas. Veterinarians, medical professionals, public health officials, and the general public must be vigilant that Lyme disease-carrying blacklegged ticks pose a public health risk in the Dundas area and the surrounding Hamilton-Wentworth region. PMID:27226771

  8. Prevalence of the Lyme Disease Spirochete, Borrelia burgdorferi, in Blacklegged Ticks, Ixodes scapularis at Hamilton-Wentworth, Ontario

    Science.gov (United States)

    Scott, John D.; Anderson, John F.; Durden, Lance A.; Smith, Morgan L.; Manord, Jodi M.; Clark, Kerry L.

    2016-01-01

    Lyme disease has emerged as a major health concern in Canada, where the etiological agent, Borrelia burgdorferi sensu lato (s.l.), a spirochetal bacterium, is typically spread by the bite of certain ticks. This study explores the presence of B. burgdorferi s.l. in blacklegged ticks, Ixodes scapularis, collected at Dundas, Ontario (a locality within the region of Hamilton-Wentworth). Using passive surveillance, veterinarians and pet groomers were asked to collect blacklegged ticks from dogs and cats with no history of travel. Additionally, I. scapularis specimens were submitted from local residents and collected by flagging. Overall, 12 (41%) of 29 blacklegged ticks were infected with B. burgdorferi s.l. Using polymerase chain reaction (PCR) and DNA sequencing, two borrelial amplicons were characterized as B. burgdorferi sensu stricto (s.s.), a genospecies pathogenic to humans and certain domestic animals. Notably, three different vertebrate hosts each had two engorged I. scapularis females removed on the same day and, likewise, one cat had three repeat occurrences of this tick species. These multiple infestations suggest that a population of I. scapularis may be established in this area. The local public health unit has been underreporting the presence of B. burgdorferi s.l.-infected I. scapularis in the area encompassing Dundas. Our findings raise concerns about the need to erect tick warning signs in parkland areas. Veterinarians, medical professionals, public health officials, and the general public must be vigilant that Lyme disease-carrying blacklegged ticks pose a public health risk in the Dundas area and the surrounding Hamilton-Wentworth region. PMID:27226771

  9. Lyme disease caused by Borrelia burgdorferi with two homeologous 16S rRNA genes: a case report

    Directory of Open Access Journals (Sweden)

    Lee SH

    2016-04-01

    Full Text Available Sin Hang Lee,1,21Pathology Department, Milford Hospital, Milford, CT, USA; 2Milford Molecular Diagnostics, Milford, CT, USA Abstract: Lyme disease (LD, the most common tick-borne disease in North America, is believed to be caused exclusively by Borrelia burgdorferi sensu stricto and is usually diagnosed by clinical evaluation and serologic assays. As reported previously in a peer-reviewed article, a 13-year-old boy living in the Northeast of the USA was initially diagnosed with LD based on evaluation of his clinical presentations and on serologic test results. The patient was treated with a course of oral doxycycline for 28 days, and the symptoms resolved. A year later, the boy developed a series of unusual symptoms and did not attend school for 1 year. A LD specialist reviewed the case and found the serologic test band patterns nondiagnostic of LD. The boy was admitted to a psychiatric hospital. After discharge from the psychiatric hospital, a polymerase chain reaction test performed in a winter month when the boy was 16 years old showed a low density of B. burgdorferi sensu lato in the blood of the patient, confirmed by partial 16S rRNA (ribosomal RNA gene sequencing. Subsequent DNA sequencing analysis presented in this report demonstrated that the spirochete isolate was a novel strain of B. burgdorferi with two homeologous 16S rRNA genes, which has never been reported in the world literature. This case report shows that direct DNA sequencing is a valuable tool for reliable molecular diagnosis of Lyme and related borrelioses, as well as for studies of the diversity of the causative agents of LD because LD patients infected by a rare or novel borrelial variant may produce an antibody pattern that can be different from the pattern characteristic of an infection caused by a typical B. burgdorferi sensu stricto strain. Keywords: Lyme disease, Borrelia burgdorferi, homeologous 16S rRNA genes, DNA sequencing

  10. Imbalanced presence of Borrelia burgdorferi s.l. multilocus sequence types in clinical manifestations of Lyme borreliosis.

    Science.gov (United States)

    Coipan, E Claudia; Jahfari, Setareh; Fonville, Manoj; Oei, G Anneke; Spanjaard, Lodewijk; Takumi, Katsuhisa; Hovius, Joppe W R; Sprong, Hein

    2016-08-01

    In this study we used typing based on the eight multilocus sequence typing scheme housekeeping genes (MLST) and 5S-23S rDNA intergenic spacer (IGS) to explore the population structure of Borrelia burgdorferi sensu lato isolates from patients with Lyme borreliosis (LB) and to test the association between the B. burgdorferi s.l. sequence types (ST) and the clinical manifestations they cause in humans. Isolates of B. burgdorferi from 183 LB cases across Europe, with distinct clinical manifestations, and 257 Ixodes ricinus lysates from The Netherlands, were analyzed for this study alone. For completeness, we incorporated in our analysis also 335 European B. burgdorferi s.l. MLST profiles retrieved from literature. Borrelia afzelii and Borrelia bavariensis were associated with human cases of LB while Borrelia garinii, Borrelia lusitaniae and Borrelia valaisiana were associated with questing I. ricinus ticks. B. afzelii was associated with acrodermatitis chronica atrophicans, while B. garinii and B. bavariensis were associated with neuroborreliosis. The samples in our study belonged to 251 different STs, of which 94 are newly described, adding to the overall picture of the genetic diversity of Borrelia genospecies. The fraction of STs that were isolated from human samples was significantly higher for the genospecies that are known to be maintained in enzootic cycles by mammals (B. afzelii, B. bavariensis, and Borrelia spielmanii) than for genospecies that are maintained by birds (B. garinii and B. valaisiana) or lizards (B. lusitaniae). We found six multilocus sequence types that were significantly associated to clinical manifestations in humans and five IGS haplotypes that were associated with the human LB cases. While IGS could perform just as well as the housekeeping genes in the MLST scheme for predicting the infectivity of B. burgdorferi s.l., the advantage of MLST is that it can also capture the differential invasiveness of the various STs. PMID:27125686

  11. Diversity within Borrelia burgdorferi sensu lato genospecies in Switzerland by recA gene sequence

    OpenAIRE

    Casati, Simona; Bernasconi, Marco V.; Gern, Lise; Piffaretti, Jean-Claude

    2006-01-01

    A total of 874 Ixodes ricinus ticks were collected in Switzerland to investigate the genetic diversity of the Borrelia population. We integrated to the RT-PCR method the DNA sequence analysis of a 162-bp fragment of the recA gene. Five genospecies were detected: Borrelia afzelii, Borrelia burgdorferi s.s., Borrelia garinii, Borrelia valaisiana, and Borrelia lusitaniae. A heterogeneous distribution was observed within the B. burgdorferi s.l. genospecies. The most prevalent and diverse genospec...

  12. Disruption of bbe02 by Insertion of a Luciferase Gene Increases Transformation Efficiency of Borrelia burgdorferi and Allows Live Imaging in Lyme Disease Susceptible C3H Mice.

    Directory of Open Access Journals (Sweden)

    Kamfai Chan

    Full Text Available Lyme disease is the most prevalent tick-borne disease in North America and Europe. The causative agent, Borrelia burgdorferi persists in the white-footed mouse. Infection with B. burgdorferi can cause acute to persistent multisystemic Lyme disease in humans. Some disease manifestations are also exhibited in the mouse model of Lyme disease. Genetic manipulation of B. burgdorferi remains difficult. First, B. burgdorferi contains a large number of endogenous plasmids with unique sequences encoding unknown functions. The presence of these plasmids needs to be confirmed after each genetic manipulation. Second, the restriction modification defense systems, including that encoded by bbe02 gene lead to low transformation efficiency in B. burgdorferi. Therefore, studying the molecular basis of Lyme pathogenesis is a challenge. Furthermore, investigation of the role of a specific B. burgdorferi protein throughout infection requires a large number of mice, making it labor intensive and expensive. To overcome the problems associated with low transformation efficiency and to reduce the number of mice needed for experiments, we disrupted the bbe02 gene of a highly infectious and pathogenic B. burgdorferi strain, N40 D10/E9 through insertion of a firefly luciferase gene. The bbe02 mutant shows higher transformation efficiency and maintains luciferase activity throughout infection as detected by live imaging of mice. Infectivity and pathogenesis of this mutant were comparable to the wild-type N40 strain. This mutant will serve as an ideal parental strain to examine the roles of various B. burgdorferi proteins in Lyme pathogenesis in the mouse model in the future.

  13. Introduced Siberian chipmunks (Tamias sibiricus barberi) harbor more-diverse Borrelia burgdorferi sensu lato genospecies than native bank voles (Myodes glareolus)

    OpenAIRE

    Marsot, Maud; Sigaud, M.; Chapuis, J L; Ferquel, E.; Vourc'H, Gwenaël

    2011-01-01

    Little attention has been given in scientific literature to how introduced species may act as a new host for native infectious agents and modify the epidemiology of a disease. In this study, we investigated whether an introduced species, the Siberian chipmunk (Tamias sibiricus barberi), was a potentially new reservoir host for Borrelia burgdorferi sensu lato, the causative agent of Lyme disease. First, we ascertained whether chipmunks were infected by all of the B. burgdorferi sensu lato geno...

  14. Introduced Siberian Chipmunks (Tamias sibiricus barberi) Harbor More-Diverse Borrelia burgdorferi Sensu Lato Genospecies than Native Bank Voles (Myodes glareolus)▿

    OpenAIRE

    Marsot, M.; Sigaud, M.; Chapuis, J L; Ferquel, E.; Cornet, M.; Vourc'h, G

    2011-01-01

    Little attention has been given in scientific literature to how introduced species may act as a new host for native infectious agents and modify the epidemiology of a disease. In this study, we investigated whether an introduced species, the Siberian chipmunk (Tamias sibiricus barberi), was a potentially new reservoir host for Borrelia burgdorferi sensu lato, the causative agent of Lyme disease. First, we ascertained whether chipmunks were infected by all of the B. burgdorferi sensu lato geno...

  15. Borrelia burgdorferi antibodies in dogs from Cotia county, São Paulo State, Brazil

    Directory of Open Access Journals (Sweden)

    JOPPERT Adriana Marques

    2001-01-01

    Full Text Available Dogs sera samples collected from Cotia County, São Paulo were tested using indirect immunoenzymatic test (ELISA in order to study Lyme disease serology in dogs. ELISA method was standardized and G39/40 North American strain of Borrelia burgdorferi was used as antigen. Positive results were confirmed employing the Western blotting technique. Because of the possibility of cross-reactions, sera were also tested for different serological strains of Leptospira interrogans and L. biflexa using microscopic sera agglutination test. Twenty-three of 237 (9.7% serum samples were positive in the ELISA; 20 of them (86.9% were confirmed by the Western blotting, what suggests that Cotia may be a risk area for Lyme disease. Although 4 samples (1.7% were positive for Lyme disease and leptospirosis, no correlation was found between the results (X² = 0.725; p = 0.394 what suggests absence of serological cross reactivity.

  16. Geographical differences in seroprevalence of Borrelia burgdorferi antibodies in Norway, 2011-2013.

    Science.gov (United States)

    Vestrheim, Didrik F; White, Richard A; Aaberge, Ingeborg S; Aase, Audun

    2016-07-01

    Detection of specific antibodies against Borrelia burgdorferi sensu lato is a useful aid for the diagnosis of Lyme borreliosis. However, antibodies are present in the general population. The seroprevalence increase with age, and varies according to the prevalence of infected ticks. We performed a seroprevalence study of IgM and IgG antibody reactivity against B. burgdorferi sensu lato in Norway by age-groups and geography, in order to provide a reference set of seroprevalence to inform the interpretation of positive test results. We used two commercially available enzyme immuno assays (EIA) and a multiplexed bead assay to detect Borrelia IgG antibodies in a convenience sample of 3057 sera collected from clinical chemistry laboratories in 10 of 19 counties in Norway between December 2011 and January 2013. We estimated seroprevalence by age and county by a logistic regression model. IgM antibodies were detected by two commercially available EIAs and a multiplexed bead assay. The overall seroprevalence of Borrelia IgG was 4.0% (95% CI: 2.4-6.6%) and 4.2% (2.6-6.8%) by the two EIAs, respectively. The seroprevalence increased by age, and by geography from north to south. The IgG assays showed a good agreement for positive test results. All sera positive for IgG in the multiplexed bead assay reacted with the VlsE antigen, and also had high antibody levels by EIA. The Borrelia seroprevalence varied by geography and increased by age. The results indicate regional differences in pre-test probabilities for positive test results, and can inform the interpretation of laboratory results. PMID:26961275

  17. Novel methods for surveying reservoir hosts and vectors of Borrelia burgdorferi in Northern Minnesota

    Science.gov (United States)

    Seifert, Veronica Aili

    Lyme disease is the most prevalent tick-borne disease in North America and presents challenges to clinicians, researchers and the public in diagnosis, treatment and prevention. Lyme disease is caused by the spirochete, Borrelia burgdorferi, which is a zoonotic pathogen obligate upon hematophagous arthropod vectors and propagates in small mammal reservoir hosts. Identifying factors governing zoonotic diseases within regions of high-risk provides local health and agricultural agencies with necessary information to formulate public policy and implement treatment protocols to abate the rise and expansion of infectious disease outbreaks. In the United States, the documented primary reservoir host of Lyme disease is the white-footed mouse, Peromyscus leucopus, and the arthropod vector is the deer tick, Ixodes scapularis. Reducing the impact of Lyme disease will need novel methods for identifying both the reservoir host and the tick vector. The reservoir host, Peromyscus leucopus is difficult to distinguish from the virtually identical Peromyscus maniculatus that also is present in Northern Minnesota, a region where Lyme disease is endemic. Collection of the Ixodes tick, the Lyme disease vector, is difficult as this is season dependent and differs from year to year. This study develops new strategies to assess the extent of Borrelia burgdorferi in the local environment of Northern Minnesota. A selective and precise method to identify Peromyscus species was developed. This assay provides a reliable and definitive method to identify the reservoir host, Peromyscus leucopus from a physically identical and sympatric Peromyscus species, Peromyscus maniculatus. A new strategy to collect ticks for measuring the disbursement of Borrelia was employed. Students from local high schools were recruited to collect ticks. This strategy increased the available manpower to cover greater terrain, provided students with valuable experience in research methodology, and highlighted the

  18. Inhibition of the Production of Anti-OspA Borreliacidal Antibody with T Cells from Hamsters Vaccinated against Borrelia burgdorferi

    OpenAIRE

    Jensen, Jani R.; Du Chateau, Brian K.; Munson, Erik L.; Callister, Steven M.; Schell, Ronald F.

    1998-01-01

    The serious morbidity associated with Lyme borreliosis has focused considerable effort on the development of a comprehensive vaccine for protection against infection with Borrelia burgdorferi. Induction of borreliacidal antibody by vaccination or infection has been shown to correlate with protection of humans and animals against infection with the Lyme spirochete. In this report, we showed that high levels of borreliacidal antibody (titer of 1,280) were produced in vitro when T and B cells fr...

  19. DNA Sequencing Diagnosis of Off-Season Spirochetemia with Low Bacterial Density in Borrelia burgdorferi and Borrelia miyamotoi Infections

    OpenAIRE

    Sin Hang Lee; Vigliotti, Jessica S.; Vigliotti, Veronica S; William Jones; Moorcroft, Thomas A.; Katherine Lantsman

    2014-01-01

    A highly conserved 357-bp segment of the 16S ribosomal RNA gene (16S rDNA) of Borrelia burgdorferi sensu lato and the correspondent 358-bp segment of the Borrelia miyamotoi gene were amplified by a single pair of nested polymerase chain reaction (PCR) primers for detection, and the amplicons were used as the templates for direct Sanger DNA sequencing. Reliable molecular diagnosis of these borreliae was confirmed by sequence alignment analysis of the hypervariable regions of the PCR amplicon,...

  20. An Enhanced ELISPOT Assay for Sensitive Detection of Antigen-Specific T Cell Responses to Borrelia burgdorferi

    OpenAIRE

    Kellermann, Gottfried H.; Lehmann, Paul V; Diana R. Roen; Chenggang Jin

    2013-01-01

    Lyme Borreliosis is an infectious disease caused by the spirochete Borrelia burgdorferi that is transmitted through the bite of infected ticks. Both B cell-mediated humoral immunity and T cell immunity develop during natural Borrelia infection. However, compared with humoral immunity, the T cell response to Borrelia infection has not been well elucidated. In this study, a novel T cell-based assay was developed and validated for the sensitive detection of antigen-specific T cell response to B....

  1. Borrelia burgdorferi CheD Promotes Various Functions in Chemotaxis and the Pathogenic Life Cycle of the Spirochete.

    Science.gov (United States)

    Moon, Ki Hwan; Hobbs, Gerry; Motaleb, M A

    2016-06-01

    Borrelia burgdorferi possesses a sophisticated chemotaxis signaling system; however, the roles of the majority of the chemotaxis proteins in the infectious life cycle have not yet been demonstrated. Specifically, the role of CheD during host colonization has not been demonstrated in any bacterium. Here, we systematically characterized the B. burgdorferi CheD homolog using genetics and biochemical and mouse-tick-mouse infection cycle studies. Bacillus subtilis CheD plays an important role in chemotaxis by deamidation of methyl-accepting chemotaxis protein receptors (MCPs) and by increasing the receptor kinase activity or enhancing CheC phosphatase activity, thereby regulating the levels of the CheY response regulator. Our biochemical analysis indicates that B. burgdorferi CheD significantly enhances CheX phosphatase activity by specifically interacting with the phosphatase. Moreover, CheD specifically binds two of the six MCPs, indicating that CheD may also modulate the receptor proteins. Although the motility of the cheD mutant cells was indistinguishable from that of the wild-type cells, the mutant did exhibit reduced chemotaxis. Importantly, the mutant showed significantly reduced infectivity in C3H/HeN mice via needle inoculation. Mouse-tick-mouse infection assays indicated that CheD is dispensable for acquisition or transmission of spirochetes; however, the viability of cheD mutants in ticks is marginally reduced compared to that of the wild-type or complemented cheD spirochetes. These data suggest that CheD plays an important role in the chemotaxis and pathogenesis of B. burgdorferi We propose potential connections between CheD, CheX, and MCPs and discuss how these interactions play critical roles during the infectious life cycle of the spirochete. PMID:27021244

  2. Sensitivity of spirochetes from \\kur{Borrelia burgdorferi} sensu lato complex to human complement: infection potential of selected species

    OpenAIRE

    Tichá, Lucie

    2015-01-01

    Sensitivity of spirochetes from Borrelia burgdorferi sensu lato complex to serum complement of humans of different age and sex was analyzed. Complement-mediated Borrelia killing was observed in different combination of serum and selected Borrelia genospecies. The obtained results confirmed that age itself does not influence the sensitivity of human to Borrelia infection. However, the females seem to be more vulnerable to it. Each of ten tested Borrelia species was proved to be potentially inf...

  3. Lyme disease caused by Borrelia burgdorferi with two homeologous 16S rRNA genes: a case report.

    Science.gov (United States)

    Lee, Sin Hang

    2016-01-01

    Lyme disease (LD), the most common tick-borne disease in North America, is believed to be caused exclusively by Borrelia burgdorferi sensu stricto and is usually diagnosed by clinical evaluation and serologic assays. As reported previously in a peer-reviewed article, a 13-year-old boy living in the Northeast of the USA was initially diagnosed with LD based on evaluation of his clinical presentations and on serologic test results. The patient was treated with a course of oral doxycycline for 28 days, and the symptoms resolved. A year later, the boy developed a series of unusual symptoms and did not attend school for 1 year. A LD specialist reviewed the case and found the serologic test band patterns nondiagnostic of LD. The boy was admitted to a psychiatric hospital. After discharge from the psychiatric hospital, a polymerase chain reaction test performed in a winter month when the boy was 16 years old showed a low density of B. burgdorferi sensu lato in the blood of the patient, confirmed by partial 16S rRNA (ribosomal RNA) gene sequencing. Subsequent DNA sequencing analysis presented in this report demonstrated that the spirochete isolate was a novel strain of B. burgdorferi with two homeologous 16S rRNA genes, which has never been reported in the world literature. This case report shows that direct DNA sequencing is a valuable tool for reliable molecular diagnosis of Lyme and related borrelioses, as well as for studies of the diversity of the causative agents of LD because LD patients infected by a rare or novel borrelial variant may produce an antibody pattern that can be different from the pattern characteristic of an infection caused by a typical B. burgdorferi sensu stricto strain. PMID:27186082

  4. Effect of salivary gland extract from Ixodes ricinus ticks on the proliferation of Borrelia burgdorferi sensu stricto in vivo

    Czech Academy of Sciences Publication Activity Database

    Macháčková, Martina; Oborník, Miroslav; Kopecký, Jan

    2006-01-01

    Roč. 53, č. 2 (2006), s. 153-158. ISSN 0015-5683 R&D Projects: GA ČR GA524/05/0811 Grant ostatní: Studentská grantová agentura, Biologická fakulta Jihočeské univerzity(CZ) SGA2004/009 Institutional research plan: CEZ:AV0Z60220518 Keywords : Borrelia burgdorferi * Ixodes ricinus * saliva -activated transmission Subject RIV: EC - Immunology Impact factor: 1.511, year: 2006

  5. Insertion of fluorescent fatty acid probes into the outer membranes of the pathogenic spirochaetes Treponema pallidum and Borrelia burgdorferi.

    Science.gov (United States)

    Cox, D L; Radolf, J D

    2001-05-01

    The authors examined the ability of octadecanoyl (C(18)), hexadecanoyl (C(16)) and dodecanoyl (C(12)) fatty acid (FA) conjugates of 5-aminofluorescein (OAF, HAF and DAF, respectively) to insert into the outer membranes (OMs) of Treponema pallidum, Borrelia burgdorferi and Escherichia coli. Biophysical studies have demonstrated that these compounds stably insert into phospholipid bilayers with the acyl chain within the hydrophobic interior of the apical leaflet and the hydrophilic fluorescein moiety near the phospholipid head groups. Consistent with the known poor intrinsic permeability of the E. coli OM to hydrophobic compounds and surfactants, E. coli was not labelled with any of the FA probes. OAF inserted more readily into OMs of B. burgdorferi than into those of T. pallidum, although both organisms were completely labelled at concentrations at or below 2 microg ml(-1). Intact spirochaetes were labelled with OAF but not with antibodies against known periplasmic antigens, thereby confirming that the probe interacted exclusively with the spirochaetal OMs. Separate experiments in which organisms were cooled to 4 degrees C (i.e. below the OM phase-transition temperatures) indicated that labelling with OAF was due to insertion of the probe into the OMs. B. burgdorferi, but not T. pallidum, was labelled by relatively high concentrations of HAF and DAF. Taken as a whole, these findings support the prediction that the lack of lipopolysaccharide renders T. pallidum and B. burgdorferi OMs markedly more permeable to lipophilic compounds than their Gram-negative bacterial counterparts. The data also raise the intriguing possibility that these two pathogenic spirochaetes obtain long-chain FAs, nutrients they are unable to synthesize, by direct permeation of their OMs. PMID:11320119

  6. Role of Acetyl-Phosphate in Activation of the Rrp2-RpoN-RpoS Pathway in Borrelia burgdorferi

    Science.gov (United States)

    Xu, Haijun; Caimano, Melissa J.; Lin, Tao; He, Ming; Radolf, Justin D.; Norris, Steven J.; Gheradini, Frank; Wolfe, Alan J.; Yang, X. Frank

    2010-01-01

    Borrelia burgdorferi, the Lyme disease spirochete, dramatically alters its transcriptome and proteome as it cycles between the arthropod vector and mammalian host. During this enzootic cycle, a novel regulatory network, the Rrp2-RpoN-RpoS pathway (also known as the σ54–σS sigma factor cascade), plays a central role in modulating the differential expression of more than 10% of all B. burgdorferi genes, including the major virulence genes ospA and ospC. However, the mechanism(s) by which the upstream activator and response regulator Rrp2 is activated remains unclear. Here, we show that none of the histidine kinases present in the B. burgdorferi genome are required for the activation of Rrp2. Instead, we present biochemical and genetic evidence that supports the hypothesis that activation of the Rrp2-RpoN-RpoS pathway occurs via the small, high-energy, phosphoryl-donor acetyl phosphate (acetyl∼P), the intermediate of the Ack-Pta (acetate kinase-phosphate acetyltransferase) pathway that converts acetate to acetyl-CoA. Supplementation of the growth medium with acetate induced activation of the Rrp2-RpoN-RpoS pathway in a dose-dependent manner. Conversely, the overexpression of Pta virtually abolished acetate-induced activation of this pathway, suggesting that acetate works through acetyl∼P. Overexpression of Pta also greatly inhibited temperature and cell density-induced activation of RpoS and OspC, suggesting that these environmental cues affect the Rrp2-RpoN-RpoS pathway by influencing acetyl∼P. Finally, overexpression of Pta partially reduced infectivity of B. burgdorferi in mice. Taken together, these findings suggest that acetyl∼P is one of the key activating molecule for the activation of the Rrp2-RpoN-RpoS pathway and support the emerging concept that acetyl∼P can serve as a global signal in bacterial pathogenesis. PMID:20862323

  7. Lyme disease caused by Borrelia burgdorferi with two homeologous 16S rRNA genes: a case report

    Science.gov (United States)

    Lee, Sin Hang

    2016-01-01

    Lyme disease (LD), the most common tick-borne disease in North America, is believed to be caused exclusively by Borrelia burgdorferi sensu stricto and is usually diagnosed by clinical evaluation and serologic assays. As reported previously in a peer-reviewed article, a 13-year-old boy living in the Northeast of the USA was initially diagnosed with LD based on evaluation of his clinical presentations and on serologic test results. The patient was treated with a course of oral doxycycline for 28 days, and the symptoms resolved. A year later, the boy developed a series of unusual symptoms and did not attend school for 1 year. A LD specialist reviewed the case and found the serologic test band patterns nondiagnostic of LD. The boy was admitted to a psychiatric hospital. After discharge from the psychiatric hospital, a polymerase chain reaction test performed in a winter month when the boy was 16 years old showed a low density of B. burgdorferi sensu lato in the blood of the patient, confirmed by partial 16S rRNA (ribosomal RNA) gene sequencing. Subsequent DNA sequencing analysis presented in this report demonstrated that the spirochete isolate was a novel strain of B. burgdorferi with two homeologous 16S rRNA genes, which has never been reported in the world literature. This case report shows that direct DNA sequencing is a valuable tool for reliable molecular diagnosis of Lyme and related borrelioses, as well as for studies of the diversity of the causative agents of LD because LD patients infected by a rare or novel borrelial variant may produce an antibody pattern that can be different from the pattern characteristic of an infection caused by a typical B. burgdorferi sensu stricto strain. PMID:27186082

  8. Heterogeneity of outer membrane proteins in Borrelia burgdorferi: comparison of osp operons of three isolates of different geographic origins.

    OpenAIRE

    JONSSON, M; Noppa, L; Barbour, A G; Bergström, S

    1992-01-01

    Biochemical and immunochemical studies of the outer membrane proteins of Borrelia burgdorferi have shown that the OspA and OspB proteins from strains of different geographic origins may differ considerably in their reactivities with monoclonal antibodies and in their apparent molecular weights. To further characterize this variation in Osp proteins between strains, the osp operons and deduced translation products from two strains, one from Sweden (ACAI) and one from eastern Russia (Ip90), wer...

  9. Role of acetyl-phosphate in activation of the Rrp2-RpoN-RpoS pathway in Borrelia burgdorferi.

    Directory of Open Access Journals (Sweden)

    Haijun Xu

    Full Text Available Borrelia burgdorferi, the Lyme disease spirochete, dramatically alters its transcriptome and proteome as it cycles between the arthropod vector and mammalian host. During this enzootic cycle, a novel regulatory network, the Rrp2-RpoN-RpoS pathway (also known as the σ(54-σ(S sigma factor cascade, plays a central role in modulating the differential expression of more than 10% of all B. burgdorferi genes, including the major virulence genes ospA and ospC. However, the mechanism(s by which the upstream activator and response regulator Rrp2 is activated remains unclear. Here, we show that none of the histidine kinases present in the B. burgdorferi genome are required for the activation of Rrp2. Instead, we present biochemical and genetic evidence that supports the hypothesis that activation of the Rrp2-RpoN-RpoS pathway occurs via the small, high-energy, phosphoryl-donor acetyl phosphate (acetyl∼P, the intermediate of the Ack-Pta (acetate kinase-phosphate acetyltransferase pathway that converts acetate to acetyl-CoA. Supplementation of the growth medium with acetate induced activation of the Rrp2-RpoN-RpoS pathway in a dose-dependent manner. Conversely, the overexpression of Pta virtually abolished acetate-induced activation of this pathway, suggesting that acetate works through acetyl∼P. Overexpression of Pta also greatly inhibited temperature and cell density-induced activation of RpoS and OspC, suggesting that these environmental cues affect the Rrp2-RpoN-RpoS pathway by influencing acetyl∼P. Finally, overexpression of Pta partially reduced infectivity of B. burgdorferi in mice. Taken together, these findings suggest that acetyl∼P is one of the key activating molecule for the activation of the Rrp2-RpoN-RpoS pathway and support the emerging concept that acetyl∼P can serve as a global signal in bacterial pathogenesis.

  10. Detection and differentiation of Borrelia burgdorferi sensu lato in ticks collected from sheep and cattle in China

    OpenAIRE

    Jorgensen Wayne; Ren Qiaoyun; Liu Aihong; Liu Junlong; Liu Zhijie; Ma Miling; Li Youquan; Xu Zongke; Fu Yuguang; Yang Jifei; Guan Guiquan; Niu Qingli; Luo Jianxun; Yin Hong

    2011-01-01

    Abstract Background Lyme disease caused by Borrelia burgdorferi sensu lato complex is an important endemic zoonosis whose distribution is closely related to the main ixodid tick vectors. In China, isolated cases of Lyme disease infection of humans have been reported in 29 provinces. Ticks, especially ixodid ticks are abundant and a wide arrange of Borrelia natural reservoirs are present. In this study, we developed a reverse line blot (RLB) to identify Borrelia spp. in ticks collected from sh...

  11. Borrelia burgdorferi Infection-Associated Surface Proteins ErpP, ErpA, and ErpC Bind Human Plasminogen▿

    OpenAIRE

    Brissette, Catherine A.; Haupt, Katrin; Barthel, Diana; Cooley, Anne E.; Bowman, Amy; Skerka, Christina; Wallich, Reinhard; Zipfel, Peter F.; Kraiczy, Peter; Stevenson, Brian

    2008-01-01

    Host-derived plasmin plays a critical role in mammalian infection by Borrelia burgdorferi. The Lyme disease spirochete expresses several plasminogen-binding proteins. Bound plasminogen is converted to the serine protease plasmin and thereby may facilitate the bacterium's dissemination throughout the host by degrading extracellular matrix. In this work, we demonstrate plasminogen binding by three highly similar borrelial outer surface proteins, ErpP, ErpA, and ErpC, all of which are expressed ...

  12. Two ways of experimental infection of Ixodes ricinus ticks (Acari: Ixodidae) with spirochetes of Borrelia burgdorferi sensu lato complex

    Czech Academy of Sciences Publication Activity Database

    Fišerová, Lenka; Černá, Kateřina; Horká, Helena; Kopecký, Jan

    2008-01-01

    Roč. 55, č. 2 (2008), s. 150-154. ISSN 0015-5683 R&D Projects: GA ČR GA524/05/0811; GA MŠk(CZ) LC06009 Institutional research plan: CEZ:AV0Z60220518 Keywords : Lyme disease spirochete * Borrelia burgdorferi * Borrelia baronii * Borrelia afzelii * tick * Ixodes ricinus Subject RIV: EC - Immunology Impact factor: 1.307, year: 2008

  13. PCR-Based Quantification of Borrelia burgdorferi Organisms in Canine Tissues over a 500-Day Postinfection Period

    OpenAIRE

    Straubinger, Reinhard K.

    2000-01-01

    Borrelia burgdorferi infection in beagle dogs was studied quantitatively with skin punch biopsy samples and blood samples collected at 4- and 2-week intervals, respectively, over a 500-day period. Thereafter, 25 tissue samples of each dog were collected for further analysis. Starting at day 120 after tick challenge, 12 dogs were treated with antibiotics (azithromycin, ceftriaxone, or doxycycline) for 30 consecutive days. Four dogs received no antibiotic therapy. Quantification of B. burgdorfe...

  14. Detection of Borrelia burgdorferi sensu lato and spotted fever group rickettsiae in hard ticks (Acari, Ixodidae) parasitizing bats in Poland

    OpenAIRE

    Piksa, Krzysztof; Stańczak, Joanna; Biernat, Beata; Górz, Andrzej; Nowak-Chmura, Magdalena; Siuda, Krzysztof

    2016-01-01

    A total of 491 Ixodes vespertilionis and 8 Ixodes ricinus collected from bats and cave walls in southern Poland between 2010 and 2012 were examined by the polymerase chain reaction for tick-transmitted pathogens. PCR analysis for Borrelia burgdorferi s.l., Rickettsia spp., and Anaplasma phagocytophilum yielded negative results for all I. vespertilionis. DNA of Rickettsia helvetica was detected in three specimens of I. ricinus attached to Rhinolophus hipposideros or Myotis myotis, while Borrel...

  15. BB0844, an RpoS-Regulated Protein, Is Dispensable for Borrelia burgdorferi Infectivity and Maintenance in the Mouse-Tick Infectious Cycle▿

    Science.gov (United States)

    Banik, Sukalyani; Terekhova, Darya; Iyer, Radha; Pappas, Christopher J.; Caimano, Melissa J.; Radolf, Justin D.; Schwartz, Ira

    2011-01-01

    The genome of Borrelia burgdorferi, the causative agent of Lyme disease, is comprised of a large linear chromosome and numerous smaller linear and circular plasmids. B. burgdorferi exhibits substantial genomic variation, and previous studies revealed genotype-specific variation at the right chromosomal telomere. A correlation has also been established between genotype and invasiveness. The correlation between chromosome length and genotype and between genotype and invasiveness suggested that a gene(s) at the right chromosome telomere may be required for virulence. Of particular interest was bb0844, an RpoS-regulated gene at the right telomere, the expression of which is induced when the spirochete undergoes adaptation to the mammalian host. The structure of the right chromosomal telomere was examined in 53 B. burgdorferi clinical isolates of various genotypes. Four distinct patterns were observed for bb0844: (i) chromosomal localization, (ii) plasmid localization, (iii) presence on both chromosome and plasmid, and (iv) complete absence. These patterns correlated with the B. burgdorferi genotype. On the basis of available sequence data, we propose a mechanism for the genomic rearrangements that accounts for the variability in bb0844 genomic localization. To further explore the role of BB0844 in the spirochete life cycle, a bb0844 deletion mutant was constructed by allelic exchange, and the viability of wild-type and bb0844 deletion mutants was examined in an experimental mouse-tick infection model. The bb0844 mutant was fully infectious in C3H/HeJ mice by either needle inoculation or tick transmission with B. burgdorferi-infected Ixodes scapularis larvae. Naïve larval ticks acquired both wild-type and mutant spirochetes with equal efficiency from B. burgdorferi-infected mice. The results demonstrate that BB0844 is not required for spirochete viability, pathogenicity, or maintenance in the tick vector or the mammalian host. At present, a defined role for BB0844 in B

  16. Analyses of mammalian sera in enzyme-linked immunosorbent assays with different strains of Borrelia burgdorferi sensu lato.

    Science.gov (United States)

    Magnarelli, L A; Anderson, J F; Johnson, R C

    1995-04-01

    Blood samples were collected from cottontail rabbits (Sylvilagus floridanus), raccoons (Procyon lotor), white-footed mice (Peromyscus leucopus), and white-tailed deer (Odocoileus virginianus) between 1977 and 1991 in southern Connecticut and New York State (USA) and were tested for antibodies against eight strains of Borrelia burgdorferi sensu lato in enzyme-linked immunosorbent assays. Among these spirochetes were six strains of B. burgdorferi sensu stricto, one strain of B. garinii (=IP90) and a strain (IPF) in group VS461. Sera from each study group reacted positively to all strains having origins in North America and Eurasia. Assay sensitivities normally ranged between 85% and 100% for all study groups. The lowest sensitivity (66%) was noted when mouse sera were tested with B. garinii, an isolate from Ixodes persulcatus in the former Soviet Union. Differences in serum reactivity to various strains were noted for all study groups, but because of multiple shared antigens among the closely related spirochetes tested, the selection of a particular North American strain of B. burgdorferi sensu stricto did not appear to be a critical factor for optimal assay performance. Locally obtained strains of this bacterium are preferred as coating antigens for serologic testing because of their availability. PMID:8583632

  17. Borrelia burgdorferi sensu lato in Ixodes cf. neuquenensis and Ixodes sigelos ticks from the Patagonian region of Argentina.

    Science.gov (United States)

    Sebastian, Patrick S; Bottero, Maria Noelia Saracho; Carvalho, Luis; Mackenstedt, Ute; Lareschi, Marcela; Venzal, José M; Nava, Santiago

    2016-10-01

    This study was conducted to detect Borrelia burgdorferi sensu lato infection in ixodid ticks from the Patagonia region in the south of Argentina. Therefore, ticks were collected on rodents in the provinces of Chubut, Río Negro and Santa Cruz. These ticks were identified as nymphs of Ixodes cf. neuquenensis and Ixodes sigelos. The B. burgdorferi s.l. infection was tested by a battery of PCR methods targeting the gene flagellin (fla) and the rrfA-rrlB intergenic spacer region (IGS). Three pools of I. sigelos nymphs from Chubut and Santa Cruz provinces as well as one pool of I. cf. neuquenensis nymphs from Río Negro province were tested positive in the fla-PCR. The samples of I. sigelos were also positive for the IGS-PCR. Phylogenetically, the haplotypes found in the positive ticks belong to the B. burgdorferi s.l. complex, and they were closely related to Borrelia chilensis, a genospecies isolated from Ixodes stilesi in Chile. The pathogenic relevance of the Borrelia genospecies detected in both I. neuquenensis and I. sigelos is unknown. PMID:27372197

  18. DNA Sequencing Diagnosis of Off-Season Spirochetemia with Low Bacterial Density in Borrelia burgdorferi and Borrelia miyamotoi Infections

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    Sin Hang Lee

    2014-06-01

    Full Text Available A highly conserved 357-bp segment of the 16S ribosomal RNA gene (16S rDNA of Borrelia burgdorferi sensu lato and the correspondent 358-bp segment of the Borrelia miyamotoi gene were amplified by a single pair of nested polymerase chain reaction (PCR primers for detection, and the amplicons were used as the templates for direct Sanger DNA sequencing. Reliable molecular diagnosis of these borreliae was confirmed by sequence alignment analysis of the hypervariable regions of the PCR amplicon, using the Basic Local Alignment Search Tool (BLAST provided by the GenBank. This methodology can detect and confirm B. burgdorferi and B. miyamotoi in blood samples of patients with off-season spirochetemia of low bacterial density. We found four B. miyamotoi infections among 14 patients with spirochetemia, including one patient co-infected by both B. miyamotoi and B. burgdorferi in a winter month when human exposure to tick bites is very limited in the Northeast of the U.S.A. We conclude that sensitive and reliable tests for these two Borrelia species should be implemented in the microbiology laboratory of hospitals located in the disease-endemic areas, for timely diagnosis and appropriate treatment of the patients at an early stage of the infection to prevent potential tissue damages.

  19. Evaluation of Borrelia burgdorferi BbHtrA Protease as a Vaccine Candidate for Lyme Borreliosis in Mice.

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    Amy J Ullmann

    Full Text Available Borrelia burgdorferi synthesizes an HtrA protease (BbHtrA which is a surface-exposed, conserved protein within Lyme disease spirochetes with activity toward CheX and BmpD of Borrelia spp, as well as aggrecan, fibronectin and proteoglycans found in skin, joints and neural tissues of vertebrates. An antibody response against BbHtrA is observed in Lyme disease patients and in experimentally infected laboratory mice and rabbits. Given the surface location of BbHtrA on B. burgdorferi and its ability to elicit an antibody response in infected hosts, we explored recombinant BbHtrA as a potential vaccine candidate in a mouse model of tick-transmitted Lyme disease. We immunized mice with two forms of BbHtrA: the proteolytically active native form and BbHtrA ablated of activity by a serine to alanine mutation at amino acid 226 (BbHtrA(S226A. Although inoculation with either BbHtrA or BbHtrA(S226A produced high-titer antibody responses in C3H/HeJ mice, neither antigen was successful in protecting mice from B. burgdorferi challenge. These results indicate that the search for novel vaccine candidates against Lyme borreliosis remains a challenge.

  20. HtrA, a Temperature- and Stationary Phase-Activated Protease Involved in Maturation of a Key Microbial Virulence Determinant, Facilitates Borrelia burgdorferi Infection in Mammalian Hosts.

    Science.gov (United States)

    Ye, Meiping; Sharma, Kavita; Thakur, Meghna; Smith, Alexis A; Buyuktanir, Ozlem; Xiang, Xuwu; Yang, Xiuli; Promnares, Kamoltip; Lou, Yongliang; Yang, X Frank; Pal, Utpal

    2016-08-01

    High-temperature requirement protease A (HtrA) represents a family of serine proteases that play important roles in microbial biology. Unlike the genomes of most organisms, that of Borrelia burgdorferi notably encodes a single HtrA gene product, termed BbHtrA. Previous studies identified a few substrates of BbHtrA; however, their physiological relevance could not be ascertained, as targeted deletion of the gene has not been successful. Here we show that BbhtrA transcripts are induced during spirochete growth either in the stationary phase or at elevated temperature. Successful generation of a BbhtrA deletion mutant and restoration by genetic complementation suggest a nonessential role for this protease in microbial viability; however, its remarkable growth, morphological, and structural defects during cultivation at 37°C confirm a high-temperature requirement for protease activation and function. The BbhtrA-deficient spirochetes were unable to establish infection of mice, as evidenced by assessment of culture, PCR, and serology. We show that transcript abundance as well as proteolytic processing of a borrelial protein required for cell fission and infectivity, BB0323, is impaired in BbhtrA mutants grown at 37°C, which likely contributed to their inability to survive in a mammalian host. Together, these results demonstrate the physiological relevance of a unique temperature-regulated borrelial protease, BbHtrA, which further enlightens our knowledge of intriguing aspects of spirochete biology and infectivity. PMID:27271745

  1. Efficacy of sarolaner in the prevention of Borrelia burgdorferi and Anaplasma phagocytophilum transmission from infected Ixodes scapularis to dogs.

    Science.gov (United States)

    Honsberger, Nicole A; Six, Robert H; Heinz, Thomas J; Weber, Angela; Mahabir, Sean P; Berg, Thomas C

    2016-05-30

    The efficacy of sarolaner (Simparica™, Zoetis) to prevent transmission primarily of Borrelia burgdorferi and secondarily of Anaplasma phagocytophilum from infected wild-caught Ixodes scapularis to dogs was evaluated in a placebo-controlled laboratory study. Twenty-four purpose-bred laboratory Beagles seronegative for B. burgdorferi and A. phagocytophilum antibodies were allocated randomly to one of three treatment groups: placebo administered orally on Days 0 and 7, or sarolaner at 2mg/kg administered orally on Day 0 (28 days prior to tick infestation) or on Day 7 (21 days prior to tick infestation). On Day 28, each dog was infested with approximately 25 female and 25 male wild caught adult I. scapularis that were determined to have prevalence of 57% for B. burgdorferi and 6.7% for A. phagocytophilum by PCR. In situ tick counts were conducted on Days 29 and 30. On Day 33, all ticks were counted and removed. Acaricidal efficacy was calculated based on the reduction of geometric mean live tick counts in the sarolaner-treated groups compared to the placebo-treated group for each tick count. Blood samples collected from each dog on Days 27, 49, 63, 77, 91 and 104 were tested for the presence of B. burgdorferi and A. phagocytophilum antibodies using the SNAP(®) 4Dx(®) Plus Test, and quantitatively assayed for B. burgdorferi antibodies using an ELISA test. Skin biopsies collected on Day 104 were tested for the presence of B. burgdorferi by bacterial culture and PCR. Geometric mean live tick counts for placebo-treated dogs were 14.8, 12.8, and 19.1 on Days 29, 30, and 33, respectively. The percent reductions in mean live tick counts at 1, 2, and 5 days after infestation were 86.3%, 100%, and 100% for the group treated with sarolaner 21 days prior to infestation, and 90.9%, 97.1%, and 100% for the group treated with sarolaner 28 days prior to infestation. Geometric mean live tick counts for both sarolaner-treated groups were significantly lower than those for the

  2. Investigation of Borrelia burgdorferi genotypes in Australia obtained from erythema migrans tissue

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    Mayne PJ

    2012-07-01

    Full Text Available Peter J Mayne International Lyme and Associated Diseases Society, Bethesda, MD, USA The author is a member of the International Lyme and Associated Diseases Society (ILADSBackground: Lyme disease (LD is an emerging infectious disease in Australia. There has been controversy regarding endemic lyme disease in the country for over 20 years. Borrelia burgdorferi sensu stricto (Bbss and sensu lato (Bbsl are closely related spirochetal species that are the causative agents of LD in humans. Clinical transmission of this tick-borne disease is marked by a characteristic rash known as erythema migrans (EM. This study employed molecular techniques to demonstrate the spirochetal agent of Lyme disease isolated from EM biopsies of patients in Australia and then investigate their genetic diversity.Methods: Four patients who presented to the author's practice over a one-year period from mid 2010 to mid 2011 returned positive results on central tissue biopsy of EM lesions using polymerase chain reaction (PCR analysis. The findings were confirmed by DNA sequencing, and basic local alignment search tool (BLAST analysis was then used to genetically characterize the causative organisms.Results: Three isolates were identified as Bbss that lay genotypically between strains B31 and ZS7 and were then characterized as strain 64b. One of the three isolates though may have similarity to B. bissettii a Bbsl. The fourth isolate was more appropriately placed in the sensu lato group and appeared to be similar, but not identical to, a B. valaisiana-type isolate. In this study, a central biopsy taken within 6 days of infection was used instead of conventional sampling at the leading edge, and the merits of this are discussed.Conclusion: These patients acquired infection in Australia, further proving endemic LD on the continent. Central biopsy site of EM is a useful tool for PCR evaluation. BLAST searches suggest a genetic diversity of B. burgdorferi, which has implications

  3. Reservoir competence of native North American birds for the Lyme disease spirochete, Borrelia burgdorferi

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    Ginsberg, H.S.; Buckley, P.A.; Balmforth, M.G.; Zhioua, E.; Mitra, Siddhartha; Buckley, F.G.

    2005-01-01

    Reservoir competence of the Lyme disease spirochete, Borrelia burgdorferi, was tested for six species of native North American birds: American Robin, Gray Catbird, Brown Thrasher, Eastern Towhee, Song Sparrow, and Northern Cardinal. Wild birds collected by mistnetting on Fire Island, NY, were held in a field lab in cages over water, and locally collected larval ticks were placed on the birds, harvested from the water after engorgement, and tested for infection by DFA after molting to the nymphal stage. American Robins were competent reservoirs, infecting 16.1% of larvae applied to wild-caught birds, compared to 0% of control ticks placed on uninfected lab mice. Robins that were previously infected in the lab by nymphal feeding infected 81.8% of applied larvae. Wild-caught Song Sparrows infected 4.8% of applied larvae, and 21.1% when infected by nymphal feeding. Results suggest moderate levels of reservoir competence for Northern Cardinals, lower levels for Gray Catbirds, and little evidence of reservoir competence for Eastern Towhees or Brown Thrashers. Lower infection rates in larvae applied to wild-caught birds compared to birds infected in the lab suggest that infected birds display temporal variability in infectiousness to larval ticks. Engorged larvae drop from birds abundantly during daylight hours, so the abundance of these bird species in the peridomestic environment suggests that they might contribute infected ticks to lawns and gardens.

  4. Vectors as Epidemiological Sentinels: Patterns of Within-Tick Borrelia burgdorferi Diversity.

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    Walter, Katharine S; Carpi, Giovanna; Evans, Benjamin R; Caccone, Adalgisa; Diuk-Wasser, Maria A

    2016-07-01

    Hosts including humans, other vertebrates, and arthropods, are frequently infected with heterogeneous populations of pathogens. Within-host pathogen diversity has major implications for human health, epidemiology, and pathogen evolution. However, pathogen diversity within-hosts is difficult to characterize and little is known about the levels and sources of within-host diversity maintained in natural populations of disease vectors. Here, we examine genomic variation of the Lyme disease bacteria, Borrelia burgdorferi (Bb), in 98 individual field-collected tick vectors as a model for study of within-host processes. Deep population sequencing reveals extensive and previously undocumented levels of Bb variation: the majority (~70%) of ticks harbor mixed strain infections, which we define as levels Bb diversity pre-existing in a diverse inoculum. Within-tick diversity is thus a sample of the variation present within vertebrate hosts. Within individual ticks, we detect signatures of positive selection. Genes most commonly under positive selection across ticks include those involved in dissemination in vertebrate hosts and evasion of the vertebrate immune complement. By focusing on tick-borne Bb, we show that vectors can serve as epidemiological and evolutionary sentinels: within-vector pathogen diversity can be a useful and unbiased way to survey circulating pathogen diversity and identify evolutionary processes occurring in natural transmission cycles. PMID:27414806

  5. An inverted repeat in the ospC operator is required for induction in Borrelia burgdorferi.

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    Dan Drecktrah

    Full Text Available Borrelia burgdorferi, the spirochete that causes Lyme disease, differentially regulates synthesis of the outer membrane lipoprotein OspC to infect its host. OspC is required to establish infection but then repressed in the mammal to avoid clearance by the adaptive immune response. Inverted repeats (IR upstream of the promoter have been implicated as an operator to regulate ospC expression. We molecularly dissected the distal inverted repeat (dIR of the ospC operator by site-directed mutagenesis at its endogenous location on the circular plasmid cp26. We found that disrupting the dIR but maintaining the proximal IR prevented induction of OspC synthesis by DNA supercoiling, temperature, and pH. Moreover, the base-pairing potential of the two halves of the dIR was more important than the nucleotide sequence in controlling OspC levels. These results describe a cis-acting element essential for the expression of the virulence factor OspC.

  6. Antibody profile to Borrelia burgdorferi in veterinarians from Nuevo León, Mexico, a non-endemic area of this zoonosis

    Science.gov (United States)

    Skinner-Taylor, Cassandra M.; Salinas, José A.; Arevalo-Niño, Katiushka; Galán-Wong, Luis J.; Maldonado, Guadalupe; Garza-Elizondo, Mario A.

    2016-01-01

    Objectives Lyme disease is a tick-borne disease caused by infections with Borrelia. Persons infected with Borrelia can be asymptomatic or can develop disseminated disease. Diagnosis and recognition of groups at risk of infection with Borrelia burgdorferi is of great interest to contemporary rheumatology. There are a few reports about Borrelia infection in Mexico, including lymphocytoma cases positive to B. burgdorferi sensu stricto by PCR and a patient with acrodermatitis chronica atrophicans. Veterinarians have an occupational risk due to high rates of tick contact. The aim of this work was to investigate antibodies to Borrelia in students at the Faculty of Veterinary Medicine and Zootechnics, at Nuevo León, Mexico, and determine the antibody profile to B. burgdorferi antigens. Material and methods Sera were screened using a C6 ELISA, IgG and IgM ELISA using recombinant proteins from B. burgdorferi, B. garinii and B. afzelii. Sera with positive or grey-zone values were tested by IgG Western blot to B. burgdorferi sensu stricto. Results All volunteers reported tick exposures and 72.5% remembered tick bites. Only nine persons described mild Lyme disease related symptoms, including headaches, paresthesias, myalgias and arthralgias. None of the volunteers reported erythema migrans. Nine samples were confirmed by IgG Western blot. The profile showed 89% reactivity to OspA, 67% to p83, and 45% to BmpA. Conclusions Positive sera samples shared antibody reactivity to the markers of late immune response p83 and BmpA, even if individuals did not present symptoms of Lyme arthritis or post-Lyme disease. The best criterion to diagnose Lyme disease in our country remains to be established, because it is probable that different strains coexist in Mexico. This is the first report of antibodies to B. burgdorferi in Latin American veterinarians. Veterinarians and high-risk people should be alert to take precautionary measures to prevent tick-borne diseases.

  7. A Drug Combination Screen Identifies Drugs Active against Amoxicillin-induced Round Bodies of Borrelia burgdorferi Persisters from an FDA Drug Library

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    Jie eFeng

    2016-05-01

    Full Text Available Although currently recommended antibiotics for Lyme disease such as doxycycline or amoxicillin cure the majority of the patients, about 10-20% of patients treated for Lyme disease may experience lingering symptoms including fatigue, pain, or joint and muscle aches. Under stress conditions such as starvation or antibiotic exposure, Borrelia burgdorferi can develop round body forms, which are a type of persister bacteria that are not killed by current Lyme antibiotics. To identify more effective drugs that are active against the round bodies of B. burgdorferi, we established a round body persister model induced by amoxicillin and screened the Food and Drug Administration (FDA drug library consisting of 1581 drug compounds and also 22 drug combinations using the SYBR Green I/propidium iodide (PI viability assay. We identified 23 drug candidates that have higher activity against the round bodies of B. burgdorferi than either amoxicillin or doxycycline. Eleven of these scored better than metronidazole and tinidazole which have been previously described to be active against round bodies. While some drug candidates such as daptomycin and clofazimine overlapped with a previous screen against stationary phase B. burgdorferi persisters, additional drug candidates active against round bodies we identified include artemisinin, ciprofloxacin, nifuroxime, fosfomycin, chlortetracycline, sulfacetamide, sulfamethoxypyridazine and sulfathiozole. Two triple drug combinations had the highest activity against round bodies and stationary phase B. burgdorferi persisters: artemisinin/cefoperazone/doxycycline and sulfachlorpyridazine/daptomycin/doxycycline. These findings confirm and extend previous findings that certain drug combinations have superior activity against B. burgdorferi persisters in vitro, even if pre-treated with amoxicillin. These findings may have implications for improved treatment of Lyme disease.

  8. A Drug Combination Screen Identifies Drugs Active against Amoxicillin-Induced Round Bodies of In Vitro Borrelia burgdorferi Persisters from an FDA Drug Library

    Science.gov (United States)

    Feng, Jie; Shi, Wanliang; Zhang, Shuo; Sullivan, David; Auwaerter, Paul G.; Zhang, Ying

    2016-01-01

    Although currently recommended antibiotics for Lyme disease such as doxycycline or amoxicillin cure the majority of the patients, about 10–20% of patients treated for Lyme disease may experience lingering symptoms including fatigue, pain, or joint and muscle aches. Under experimental stress conditions such as starvation or antibiotic exposure, Borrelia burgdorferi can develop round body forms, which are a type of persister bacteria that appear resistant in vitro to customary first-line antibiotics for Lyme disease. To identify more effective drugs with activity against the round body form of B. burgdorferi, we established a round body persister model induced by exposure to amoxicillin (50 μg/ml) and then screened the Food and Drug Administration drug library consisting of 1581 drug compounds and also 22 drug combinations using the SYBR Green I/propidium iodide viability assay. We identified 23 drug candidates that have higher activity against the round bodies of B. burgdorferi than either amoxicillin or doxycycline. Eleven individual drugs scored better than metronidazole and tinidazole which have been previously described to be active against round bodies. In this amoxicillin-induced round body model, some drug candidates such as daptomycin and clofazimine also displayed enhanced activity which was similar to a previous screen against stationary phase B. burgdorferi persisters not exposure to amoxicillin. Additional candidate drugs active against round bodies identified include artemisinin, ciprofloxacin, nifuroxime, fosfomycin, chlortetracycline, sulfacetamide, sulfamethoxypyridazine and sulfathiozole. Two triple drug combinations had the highest activity against amoxicillin-induced round bodies and stationary phase B. burgdorferi persisters: artemisinin/cefoperazone/doxycycline and sulfachlorpyridazine/daptomycin/doxycycline. These findings confirm and extend previous findings that certain drug combinations have superior activity against B. burgdorferi

  9. Response to Esteve-Gassent et al.: flaB sequences obtained from Texas PCR products are identical to the positive control strain Borrelia burgdorferi B31.

    Science.gov (United States)

    Norris, Steven J; Barbour, Alan G; Fish, Durland; Diuk-Wasser, Maria A

    2015-01-01

    Feria-Arroyo et al. had reported previously that, based on PCR analysis, 45% of Ixodes scapularis ticks collected in Texas and Mexico were infected with the Lyme disease spirochete Borrelia burgdorferi (Parasit. Vectors 2014, 7:199). However, our analyses of their initial data (Parasit. Vectors 2014, 7:467) and a recent response by Esteve-Gassent et al. (Parasit. Vectors 2015, 8:129) provide evidence that the positive PCR results obtained from both ribosomal RNA intergenic sequences and the flagellin gene flaB are highly likely due to contamination by the B. burgdorferi B31 positive control strain. PMID:26050617

  10. First report of Borrelia burgdorferi sensu lato in two threatened carnivores: the Marbled polecat, Vormela peregusna and the European mink, Mustela lutreola (Mammalia: Mustelidae

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    Gherman Călin M

    2012-08-01

    Full Text Available Abstract Background Lyme disease is a widespread cosmopolitan zoonosis caused by species belonging to the genus Borrelia. It is transmitted from animal reservoir hosts to humans through hard - ticks of genus Ixodes which are vectors of the disease. Case presentation Borrelia burgdorferi sensu lato infection was identified in a marbled polecat, Vormela peregusna, and two European minks, Mustela lutreola, from Romania, by PCR. RFLP revealed the presence of a single genospecies, Borrelia burgdorferi sensu stricto. Conclusions This is the first report of the Lyme disease spirochetes in the two mentioned hosts.

  11. Analysis of an ordered, comprehensive STM mutant library in infectious Borrelia burgdorferi: insights into the genes required for mouse infectivity.

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    Tao Lin

    Full Text Available The identification of genes important in the pathogenesis of Lyme disease Borrelia has been hampered by exceedingly low transformation rates in low-passage, infectious organisms. Using the infectious, moderately transformable B. burgdorferi derivative 5A18NP1 and signature-tagged versions of the Himar1 transposon vector pGKT, we have constructed a defined transposon library for the efficient genome-wide investigation of genes required for wild-type pathogenesis, in vitro growth, physiology, morphology, and plasmid replication. To facilitate analysis, the insertion sites of 4,479 transposon mutants were determined by sequencing. The transposon insertions were widely distributed across the entire B. burgdorferi genome, with an average of 2.68 unique insertion sites per kb DNA. The 10 linear plasmids and 9 circular plasmids had insertions in 33 to 100 percent of their predicted genes. In contrast, only 35% of genes in the 910 kb linear chromosome had incapacitating insertions; therefore, the remaining 601 chromosomal genes may represent essential gene candidates. In initial signature-tagged mutagenesis (STM analyses, 434 mutants were examined at multiple tissue sites for infectivity in mice using a semi-quantitative, Luminex-based DNA detection method. Examples of genes found to be important in mouse infectivity included those involved in motility, chemotaxis, the phosphoenolpyruvate phosphotransferase system, and other transporters, as well as putative plasmid maintenance genes. Availability of this ordered STM library and a high-throughput screening method is expected to lead to efficient assessment of the roles of B. burgdorferi genes in the infectious cycle and pathogenesis of Lyme disease.

  12. Genetic Variation of the Borrelia burgdorferi Gene vlsE Involves Cassette-Specific, Segmental Gene Conversion

    OpenAIRE

    Zhang, Jing-Ren; Norris, Steven J

    1998-01-01

    The Lyme disease spirochete Borrelia burgdorferi possesses 15 silent vls cassettes and a vls expression site (vlsE) encoding a surface-exposed lipoprotein. Segments of the silent vls cassettes have been shown to recombine with the vlsE cassette region in the mammalian host, resulting in combinatorial antigenic variation. Despite promiscuous recombination within the vlsE cassette region, the 5′ and 3′ coding sequences of vlsE that flank the cassette region are not subject to sequence variation...

  13. Detection of Borrelia burgdorferi sensu lato and spotted fever group rickettsiae in hard ticks (Acari, Ixodidae) parasitizing bats in Poland.

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    Piksa, Krzysztof; Stańczak, Joanna; Biernat, Beata; Górz, Andrzej; Nowak-Chmura, Magdalena; Siuda, Krzysztof

    2016-04-01

    A total of 491 Ixodes vespertilionis and 8 Ixodes ricinus collected from bats and cave walls in southern Poland between 2010 and 2012 were examined by the polymerase chain reaction for tick-transmitted pathogens. PCR analysis for Borrelia burgdorferi s.l., Rickettsia spp., and Anaplasma phagocytophilum yielded negative results for all I. vespertilionis. DNA of Rickettsia helvetica was detected in three specimens of I. ricinus attached to Rhinolophus hipposideros or Myotis myotis, while Borrelia garinii was found in one tick parasitizing Myotis daubentonii. These pathogens were recorded for the first time in hard ticks that parasitized bats. PMID:26833325

  14. Diagnostic Value of PCR for Detection of Borrelia burgdorferi in Skin Biopsy and Urine Samples from Patients with Skin Borreliosis

    OpenAIRE

    Brettschneider, S; Bruckbauer, H.; Klugbauer, N; Hofmann, H.

    1998-01-01

    Skin biopsies of 36 patients with erythema migrans and acrodermatitis chronica atrophicans (ACA) before therapy and those of 8 patients after therapy were examined for Borrelia burgdorferi DNA by PCR. Skin biopsies of 27 patients with dermatological diseases other than Lyme borreliosis and those of 10 healthy persons were examined as controls. Two different primer sets targeting 23S rRNA (PCR I) and 66-kDa protein (PCR II) genes were used. PCR was performed with freshly frozen tissue (FFT) an...

  15. Clinical characteristics associated with Borrelia burgdorferi sensu lato skin culture results in patients with erythema migrans.

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    Franc Strle

    Full Text Available Clinical characteristics associated with isolation of Borrelia burgdorferi sensu lato from skin have not been fully evaluated. To gain insight into predictors for a positive EM skin culture, we compared basic demographic, epidemiologic, and clinical data in 608 culture-proven and 501 culture-negative adult patients with solitary EM. A positive Borrelia spp. skin culture was associated with older age, a time interval of >2 days between tick bite and onset of the skin lesion, EM ≥ 5 cm in diameter, and location of the lesion on the extremities, whereas several other characteristics used as clinical case definition criteria for the diagnosis of EM (such as tick bite at the site of later EM, information on expansion of the skin lesion, central clearing were not. A patient with a 15-cm EM lesion had almost 3-fold greater odds for a positive skin culture than patients with a 5-cm lesion. Patients with a free time interval between the tick bite and onset of EM had the same probability of a positive skin culture as those who did not recall a tick bite (OR=1.02; however, the two groups had >3-fold greater odds for EM positivity than patients who reported a tick bite with no interval between the bite and onset of the lesion. In conclusion, several yet not all clinical characteristics used in EM case definitions were associated with positive Borrelia spp. skin culture. The findings are limited to European patients with solitary EM caused predominantly by B. afzelii but may not be valid for other situations.

  16. Phagosomal signaling by Borrelia burgdorferi in human monocytes involves Toll-like receptor (TLR) 2 and TLR8 cooperativity and TLR8-mediated induction of IFN-β

    Science.gov (United States)

    Cervantes, Jorge L.; Dunham-Ems, Star M.; La Vake, Carson J.; Petzke, Mary M.; Sahay, Bikash; Sellati, Timothy J.; Radolf, Justin D.; Salazar, Juan C.

    2011-01-01

    Phagocytosed Borrelia burgdorferi (Bb) induces inflammatory signals that differ both quantitatively and qualitatively from those generated by spirochetal lipoproteins interacting with Toll-like receptor (TLR) 1/2 on the surface of human monocytes. Of particular significance, and in contrast to lipoproteins, internalized spirochetes induce transcription of IFN-β. Using inhibitory immunoregulatory DNA sequences (IRSs) specific to TLR7, TLR8, and TLR9, we show that the TLR8 inhibitor IRS957 significantly diminishes production of TNF-α, IL-6, and IL-10 and completely abrogates transcription of IFN-β in Bb-stimulated monocytes. We demonstrate that live Bb induces transcription of TLR2 and TLR8, whereas IRS957 interferes with their transcriptional regulation. Using confocal and epifluorescence microscopy, we show that baseline TLR expression in unstimulated monocytes is greater for TLR2 than for TLR8, whereas expression of both TLRs increases significantly upon stimulation with live spirochetes. By confocal microscopy, we show that TLR2 colocalization with Bb coincides with binding, uptake, and formation of the phagosomal vacuole, whereas recruitment of both TLR2 and TLR8 overlaps with degradation of the spirochete. We provide evidence that IFN regulatory factor (IRF) 7 is translocated into the nucleus of Bb-infected monocytes, suggesting its activation through phosphorylation. Taken together, these findings indicate that the phagosome is an efficient platform for the recognition of diverse ligands; in the case of Bb, phagosomal signaling involves a cooperative interaction between TLR2 and TLR8 in pro- and antiinflammatory cytokine responses, whereas TLR8 is solely responsible for IRF7-mediated induction of IFN-β. PMID:21321205

  17. Prevalence of Babesia canis, Borrelia burgdorferi sensu lato, and Anaplasma phagocytophilum in hard ticks collected from meadows of Lubelskie Voivodship (eastern Poland

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    Dzięgiel Beata

    2014-03-01

    Full Text Available The aim of the study was to assess the distribution of Anaplasma phagocytophilum, Borrelia burgdorferi sensu lato, and Babesia canis in adult females and males of Ixodes ricinus and Dermacentor reticulatus ticks, inhabiting meadows near large forest complexes throughout the Lubelskie Voivodship (eastern region of Poland. Ticks were collected using the flagging method. Among 720 ticks collected, 506 were identified as D. reticulatus, and 214 as I. ricinus. DNA of B. canis and B. burgdorferi s.l. was detected in 21.3% and 0.6% of D. reticulatus ticks, respectively. In I. ricinus ticks, DNA specific to B. burgdorferi s.l. and A. phagocytophilum was detected in 5.6% and 10.3%, respectively. Co-infections of B. burgdorferi s.l. and A. phagocytophilum were found in two I. ricinus ticks. These results indicate that the Lublin region is an area at risk of tick-borne diseases of humans and animals, which must be considered in clinical practice.

  18. 伯氏疏螺旋体膜蛋白BmpA研究进展%Progresses on Borrelia burgdorferi Membrance Protein A (BmpA)

    Institute of Scientific and Technical Information of China (English)

    宝福凯; 赖名耀; 张云波; 董坚; 赵桂萍; 陈明清; 柳爱华

    2012-01-01

    Lyme disease, a global health concern, is a zoonosis, which has been a serious threat to human. The spiroehete Borrelia burgdorferi that is transmitted by the bite of hard tick (Ixodidae) is the pathogen of Lyme disease. Borrelia burgdorferi contains many membrane proteins with immungenicity and pathogenicity. Recent researches show that BmpA is an dominant immune protein of Borrelia burgdorferi, a laminin-binding protein, and an arthritogennic factor. Research progresses of BmpA protein in biological function, Lyme arthritis pathogenesis and diagnosis of lyme disease are reviewed.%莱姆病是一种人兽共患病,已严重威胁人类健康,成全球公共卫生问题,引起全球关注.伯氏疏螺旋体是莱姆病病原体,通过蜱叮咬传播而引起莱姆病,其表面存在的膜蛋白具有免疫性和致病性.BmpA (Borreli burgdorferi membrance protein A)是伯氏疏螺旋体的主要抗原之一,为层粘连蛋白结合蛋白,是莱姆关节炎的重要致病因子,对蛋白功能、诊断应用和莱姆关节炎致病机理三方面的研究进展进行概述.

  19. Linkages of Weather and Climate With Ixodes scapularis and Ixodes pacificus (Acari: Ixodidae), Enzootic Transmission of Borrelia burgdorferi, and Lyme Disease in North America.

    Science.gov (United States)

    Eisen, Rebecca J; Eisen, Lars; Ogden, Nicholas H; Beard, Charles B

    2016-03-01

    Lyme disease has increased both in incidence and geographic extent in the United States and Canada over the past two decades. One of the underlying causes is changes during the same time period in the distribution and abundance of the primary vectors: Ixodes scapularis Say and Ixodes pacificus Cooley and Kohls in eastern and western North America, respectively. Aside from short periods of time when they are feeding on hosts, these ticks exist in the environment where temperature and relative humidity directly affect their development, survival, and host-seeking behavior. Other important factors that strongly influence tick abundance as well as the proportion of ticks infected with the Lyme disease spirochete, Borrelia burgdorferi, include the abundance of hosts for the ticks and the capacity of tick hosts to serve as B. burgdorferi reservoirs. Here, we explore the linkages between climate variation and: 1) duration of the seasonal period and the timing of peak activity; 2) geographic tick distributions and local abundance; 3) enzootic B. burgdorferi transmission cycles; and 4) Lyme disease cases. We conclude that meteorological variables are most influential in determining host-seeking phenology and development, but, while remaining important cofactors, additional variables become critical when exploring geographic distribution and local abundance of ticks, enzootic transmission of B. burgdorferi, and Lyme disease case occurrence. Finally, we review climate change-driven projections for future impact on vector ticks and Lyme disease and discuss knowledge gaps and research needs. PMID:26681789

  20. The nucleotide excision repair system of Borrelia burgdorferi is the sole pathway involved in repair of DNA damage by UV light.

    Science.gov (United States)

    Hardy, Pierre-Olivier; Chaconas, George

    2013-05-01

    To survive and avoid accumulation of mutations caused by DNA damage, the genomes of prokaryotes encode a variety of DNA repair pathways most well characterized in Escherichia coli. Some of these are required for the infectivity of various pathogens. In this study, the importance of 25 DNA repair/recombination genes for Borrelia burgdorferi survival to UV-induced DNA damage was assessed. In contrast to E. coli, where 15 of these genes have an effect on survival of UV irradiation, disruption of recombinational repair, transcription-coupled repair, methyl-directed mismatch correction, and repair of arrested replication fork pathways did not decrease survival of B. burgdorferi exposed to UV light. However, the disruption of the B. burgdorferi nucleotide excision repair (NER) pathway (uvrA, uvrB, uvrC, and uvrD) resulted in a 10- to 1,000-fold increase in sensitivity to UV light. A functional NER pathway was also shown to be required for B. burgdorferi resistance to nitrosative damage. Finally, disruption of uvrA, uvrC, and uvrD had only a minor effect upon murine infection by increasing the time required for dissemination. PMID:23475971

  1. Serological survey for antibodies to Borrelia burgdorferi in rodents and detection of spirochaetes in ticks and fleas in South Moravia (Czech Republic)

    Czech Academy of Sciences Publication Activity Database

    Juřicová, Zina; Halouzka, Jiří; Hubálek, Zdeněk

    2002-01-01

    Roč. 57, č. 3 (2002), s. 383-387. ISSN 0006-3088 R&D Projects: GA AV ČR IAA6087601; GA ČR GA206/00/1204 Institutional research plan: CEZ:AV0Z6093917 Keywords : Borrelia burgdorferi * Lyme disease Subject RIV: EE - Microbiology, Virology Impact factor: 0.169, year: 2002

  2. A Borrelia burgdorferi Surface-Exposed Transmembrane Protein Lacking Detectable Immune Responses Supports Pathogen Persistence and Constitutes a Vaccine Target.

    Science.gov (United States)

    Kung, Faith; Kaur, Simarjot; Smith, Alexis A; Yang, Xiuli; Wilder, Cara N; Sharma, Kavita; Buyuktanir, Ozlem; Pal, Utpal

    2016-06-01

    Borrelia burgdorferi harbors a limited set of transmembrane surface proteins, most of which constitute key targets of humoral immune responses. Here we show that BB0405, a conserved membrane-spanning protein of unknown function, fails to evoke detectable antibody responses despite its extracellular exposure. bb0405 is a member of an operon and ubiquitously expressed throughout the rodent-tick infection cycle. The gene product serves an essential function in vivo, as bb0405-deletion mutants are unable to transmit from ticks and establish infection in mammalian hosts. Despite the lack of BB0405-specific immunoglobulin M or immunoglobulin G antibodies during natural infection, mice immunized with a recombinant version of the protein elicited high-titer and remarkably long-lasting antibody responses, conferring significant host protection against tick-borne infection. Taken together, these studies highlight the essential role of an apparently immune-invisible borrelial transmembrane protein in facilitating infection and its usefulness as a target of protective host immunity blocking the transmission of B. burgdorferi. PMID:26747708

  3. Presence of host-seeking Ixodes ricinus and their infection with Borrelia burgdorferi sensu lato in the Northern Apennines, Italy.

    Science.gov (United States)

    Ragagli, Charlotte; Mannelli, Alessandro; Ambrogi, Cecilia; Bisanzio, Donal; Ceballos, Leonardo A; Grego, Elena; Martello, Elisa; Selmi, Marco; Tomassone, Laura

    2016-06-01

    Host-seeking ticks were collected in the Northern Apennines, Italy, by dragging at 35 sites, at altitudes ranging from 680 and 1670 m above sea level (asl), from April to November, in 2010 and 2011. Ixodes ricinus (4431 larvae, 597 nymphs and 12 adults) and Haemaphysalis punctata (11,209 larvae, 313 nymphs, and 25 adults) were the most abundant species, followed by Haemaphysalis sulcata (20 larvae, five nymphs, and 13 adults), Dermacentor marginatus (42 larvae and two adults) and Ixodes hexagonus (one nymph). Greatest numbers of ticks were collected at locations characterised by southern exposure and limestone substratum, at altitudes Borrelia burgdorferi sensu lato (sl) in 294 host-seeking I. ricinus nymphs was 8.5 %. Borrelia garinii was the most frequently identified genospecies (64.0 % of positive nymphs), followed by B. valaisiana, B. burgdorferi sensu stricto, B. afzelii, and B. lusitaniae. Based upon the comparison with the results of previous studies at the same location, these research findings suggest the recent invasion of the study area by the tick vector and the agents of Lyme borreliosis. PMID:26964552

  4. Minimal role of eastern fence lizards in Borrelia burgdorferi transmission in central New Jersey oak/pine woodlands

    Science.gov (United States)

    Rulison, Eric L.; Kerr, Kaetlyn T; Dyer, Megan C; Han, Seungeun; Burke, Russell L.; Tsao, Jean I.; Ginsberg, Howard S.

    2014-01-01

    The Eastern fence lizard, Sceloporus undulatus, is widely distributed in eastern and central North America, ranging through areas with high levels of Lyme disease, as well as areas where Lyme disease is rare or absent. We studied the potential role of S. undulatus in transmission dynamics of Lyme spirochetes by sampling ticks from a variety of natural hosts at field sites in central New Jersey, and by testing the reservoir competence of S. undulatus for Borrelia burgdorferi in the laboratory. The infestation rate of ticks on fence lizards was extremely low (proportion infested = 0.087, n = 23) compared to that on white footed mice and other small mammals (proportion infested = 0.53, n = 140). Of 159 nymphs that had fed as larvae on lizards that had previously been exposed to infected nymphs, none was infected with B. burgdorferi, compared with 79.9% of 209 nymphs that had fed as larvae on infected control mice. Simulations suggest that changes in the numbers of fence lizards in a natural habitat would have little effect on the infection rate of nymphal ticks with Lyme spirochetes. We conclude that in central New Jersey S. undulatus plays a minimal role in the enzootic transmission cycle of Lyme spirochetes.

  5. Treponema pallidum Lipoprotein TP0435 Expressed in Borrelia burgdorferi Produces Multiple Surface/Periplasmic Isoforms and mediates Adherence.

    Science.gov (United States)

    Chan, Kamfai; Nasereddin, Thayer; Alter, Laura; Centurion-Lara, Arturo; Giacani, Lorenzo; Parveen, Nikhat

    2016-01-01

    The ability of Treponema pallidum, the syphilis spirochete to colonize various tissues requires the presence of surface-exposed adhesins that have been difficult to identify due to the inability to culture and genetically manipulate T. pallidum. Using a Borrelia burgdorferi-based heterologous system and gain-in-function approach, we show for the first time that a highly immunogenic lipoprotein TP0435 can be differentially processed into multiple isoforms with one variant stochastically displayed on the spirochete surface. TP0435 was previously believed to be exclusively located in T. pallidum periplasm. Furthermore, non-adherent B. burgdorferi strain expressing TP0435 acquires the ability to bind to a variety of host cells including placental cells and exhibits slow opsonophagocytosis in vitro similar to poor ex vivo phagocytosis of T. pallidum by host macrophages reported previously. This phenomenon of production of both surface and periplasmic immunogenic lipoprotein isoforms has possible implications in immune evasion of the obligate pathogen T. pallidum during infection. PMID:27161310

  6. An Enhanced ELISPOT Assay for Sensitive Detection of Antigen-Specific T Cell Responses to Borrelia burgdorferi

    Directory of Open Access Journals (Sweden)

    Gottfried H. Kellermann

    2013-09-01

    Full Text Available Lyme Borreliosis is an infectious disease caused by the spirochete Borrelia burgdorferi that is transmitted through the bite of infected ticks. Both B cell-mediated humoral immunity and T cell immunity develop during natural Borrelia infection. However, compared with humoral immunity, the T cell response to Borrelia infection has not been well elucidated. In this study, a novel T cell-based assay was developed and validated for the sensitive detection of antigen-specific T cell response to B. burgdorferi. Using interferon-g as a biomarker, we developed a new enzyme-linked immunospot method (iSpot Lyme™ to detect Borrelia antigen-specific effector/memory T cells that were activated in vivo by exposing them to recombinant Borrelia antigens ex vivo. To test this new method as a potential laboratory diagnostic tool, we performed a clinical study with a cohort of Borrelia positive patients and healthy controls. We demonstrated that the iSpot Lyme assay has a significantly higher specificity and sensitivity compared with the Western Blot assay that is currently used as a diagnostic measure. A comprehensive evaluation of the T cell response to Borrelia infection should, therefore, provide new insights into the pathogenesis, diagnosis, treatment and monitoring of Lyme disease.

  7. Assessment of decorin-binding protein A to the infectivity of Borrelia burgdorferi in the murine models of needle and tick infection

    Directory of Open Access Journals (Sweden)

    Hagman Kayla E

    2008-05-01

    Full Text Available Abstract Background Decorin-binding proteins (Dbps A and B of Borrelia burgdorferi, the agent of Lyme disease, are surface-exposed lipoproteins that presumably bind to the extracellular matrix proteoglycan, decorin. B. burgdorferi infects various tissues including the bladder, heart, joints, skin and the central nervous system, and the ability of B. burgdorferi to bind decorin has been hypothesized to be important for this disseminatory pathogenic strategy. Results To determine the role of DbpBA in the infectious lifecycle of B. burgdorferi, we created a DbpBA-deficient mutant of B. burgdorferi strain 297 and compared the infectious phenotype of the mutant to the wild-type strain in the experimental murine model of Lyme borreliosis. The mutant strain exhibited a 4-log decrease in infectivity, relative to the wild-type strain, when needle inoculated into mice. Upon complementation of the DbpBA-mutant strain with DbpA, the wild-type level of infectivity was restored. In addition, we demonstrated that the DbpBA-deficient mutant was able to colonize Ixodes scapularis larval ticks after feeding on infected mice and persist within the ticks during the molt to the nymphal state. Moreover, surprisingly, the DbpBA-mutant strain was capable of being transmitted to naïve mice via tick bite, giving rise to infected mice. Conclusion These results suggest that DbpBA is not required for the natural tick-transmission process to mammals, despite inferences from needle-inoculation experiments implying a requirement for DbpBA during mammalian infection. The combined findings also send a cautionary note regarding how results from needle-inoculation experiments with mice should be interpreted.

  8. Establishment of Multiple Locus Variable-number Tandem Repeat Analysis Assay for Genotyping of Borrelia burgdorferi sensu lato Detected in China

    Institute of Scientific and Technical Information of China (English)

    ZHOU Xin; HOU Xue Xia; GENG Zhen; ZHAO Rui; WAN Kang Lin; HAO Qin

    2014-01-01

    Objective Human Lyme Borreliosis (LB), which is caused by Borrelia burgdorferi sensu lato (B. burgdorferi), has been identified as a major arthropod-borne infectious disease in China. We aimed to develop a multiple locus variable-number tandem repeat (VNTR) analysis (MLVA) assay for the genotyping of Borrelia burgdorferi strains detected in China. Methods B. garinii PBi complete 904.246 kb chromosome and two plasmids (cp26 and lp54) were screened by using Tandem Repeats Finder program for getting potential VNTR loci, the potential VNTR loci were analyzed and identified with PCR and the VNTR loci data were analyzed and MLVA clustering tree were constrcted by using the categorical coefficient and the unweighted pair-group method with arithmetic means (UPGMA). Results We identified 5 new VNTR loci through analyzing 47 potential VNTR loci. We used the MLVA protocol to analyse 101 B. burgdorferi strains detected in China and finally identified 51 unique genotypes in 4 major clusters including B. burgdorferi sensu stricto (B.b.s.s), B. garinii, B. afzelii, and B. valaisiana, consistent with the current MLSA phylogeny studies. The allele numbers of VNTR-1, VNTR-2, VNTR-3, VNTR-4, and VNTR-5 were 7, 3, 9, 7, and 6. The Hunter-Gaston index (HGI) of five VNTR loci were 0.79, 0.22, 0.77, 0.71, and 0.67, respectively. The combined HGI of five VNTR loci was 0.96. Clustering of the strains of Xinjiang, Inner Mongolia and Heilongjiang was confirmed, and this situation was consistent with the close geographical distribution of those provinces. Conclusion The MLVA protocol esytablished in this study is easy and can show strains’ phylogenetic relationships to distinguish the strains of Borrelia species. It is useful for further phylogenetic and epidemiological analyses of Borrelia strains.

  9. Probable late lyme disease: a variant manifestation of untreated Borrelia burgdorferi infection

    Directory of Open Access Journals (Sweden)

    Aucott John N

    2012-08-01

    Full Text Available Abstract Background Lyme disease, a bacterial infection with the tick-borne spirochete Borrelia burgdorferi, can cause early and late manifestations. The category of probable Lyme disease was recently added to the CDC surveillance case definition to describe patients with serologic evidence of exposure and physician-diagnosed disease in the absence of objective signs. We present a retrospective case series of 13 untreated patients with persistent symptoms of greater than 12 weeks duration who meet these criteria and suggest a label of ‘probable late Lyme disease’ for this presentation. Methods The sample for this analysis draws from a retrospective chart review of consecutive, adult patients presenting between August 2002 and August 2007 to the author (JA, an infectious disease specialist. Patients were included in the analysis if their current illness had lasted greater than or equal to 12 weeks duration at the time of evaluation. Results Probable late Lyme patients with positive IgG serology but no history of previous physician-documented Lyme disease or appropriate Lyme treatment were found to represent 6% of our heterogeneous sample presenting with ≥ 12 weeks of symptom duration. Patients experienced a range of symptoms including fatigue, widespread pain, and cognitive complaints. Approximately one-third of this subset reported a patient-observed rash at illness onset, with a similar proportion having been exposed to non-recommended antibiotics or glucocorticosteroid treatment for their initial disease. A clinically significant response to antibiotics treatment was noted in the majority of patients with probable late Lyme disease, although post-treatment symptom recurrence was common. Conclusions We suggest that patients with probable late Lyme disease share features with both confirmed late Lyme disease and post-treatment Lyme disease syndrome. Physicians should consider the recent inclusion of probable Lyme disease in the

  10. Eradication of Biofilm-like Microcolony Structures of Borrelia burgdorferi by Daunomycin and Daptomycin but not Mitomycin C in Combination with Doxycycline and Cefuroxime

    Directory of Open Access Journals (Sweden)

    Jie eFeng

    2016-02-01

    Full Text Available Lyme disease, caused by Borrelia burgdorferi, is the most common vector-borne disease in the United States and Europe. While the majority of Lyme disease patients can resolve their symptoms if treated promptly, 10-20% of patients suffer from prolonged symptoms called post-treatment Lyme disease syndrome (PTLDS. Although the cause for PTLDS is unclear, one possibility is the presence of bacterial persisters not effectively cleared by the current Lyme antibiotics. Recent studies identified several drug candidates including daptomycin, daunomycin, doxorubicin, and mitomycin C that had good activity against B. burgdorferi persisters. However, their relative activities against B. burgdorferi persisters have not been evaluated under the same conditions. In this study, we tested the anti-persister activities of these drugs against both 7-day and 15-day old stationary phase cultures of B. burgdorferi individually as well as in combination with Lyme antibiotics doxycycline and cefuroxime (Ceftin. Our findings demonstrate daunomycin and daptomycin were more active than mitomycin C in single drug comparison at 10 and 20 µM, as well as in drug combinations with doxycycline and cefuroxime. In addition, daunomycin was more active than doxorubicin which correlated with their ability to stain and accumulate in B. burgdorferi. The two drug combination of doxycycline and cefuroxime was unable to eradicate biofilm-like microcolonies of B. burgdorferi persisters. However, the addition of either daunomycin or daptomycin to the doxycycline + cefuroxime combination completely eradicated the biofilm-like structures and produced no visible bacterial regrowth after 7 days and 21 days, while the addition of doxorubicin was unable to prevent regrowth at either 7 day or 21 day subculture. Mitomycin C in combination with doxycycline and cefuroxime caused no regrowth at 7 days but visible spirochetal regrowth occurred after 21 day subculture. Furthermore, we found that

  11. Lipoproteins of Borrelia burgdorferi and Treponema pallidum activate cachectin/tumor necrosis factor synthesis. Analysis using a CAT reporter construct.

    Science.gov (United States)

    Radolf, J D; Norgard, M V; Brandt, M E; Isaacs, R D; Thompson, P A; Beutler, B

    1991-09-15

    Lipoproteins from two pathogenic spirochetes (Borrelia burgdorferi and Treponema pallidum) induced the biosynthesis of TNF in murine macrophages and in permanently transformed macrophages of the cell line RAW 264.7. Induction was studied by measuring the secretion of biologically active TNF and by measuring the activity of the reporter enzyme chloramphenicol acetyltransferase (CAT) produced within macrophages transfected with an endotoxin-responsive CAT construct. Several lines of evidence indicated that the induction of TNF and CAT was attributable to the spirochete lipoproteins rather than to contaminating or endogenous LPS: 1) the dose response curves observed for the lipoproteins were markedly different from those obtained with LPS; 2) lipoprotein-mediated activation was unaffected by amounts of polymyxin B that completely neutralized the induction of TNF and CAT by LPS, 3) low concentrations of the lipoproteins induced TNF in macrophages from endotoxin-unresponsive C3H/HeJ mice as effectively as in macrophages from normal C3H/HeN mice, and 4) isolated spirochete lipoproteins, but not a non-lipoprotein immunogen, were potent inducers of CAT in the transformed macrophages. Moreover, LPS was not detected in the B. burgdorferi lipoprotein mixtures by Limulus amebocyte lysate assay. Proteolytic digestion of the intact bacterial protein preparations only modestly diminished their ability to activate the cells, suggesting that small lipopeptides comprise the biologically active portions of the molecules, as is the case with the murein lipoprotein of Escherichia coli. Through their ability to induce TNF production by macrophages, spirochete lipoproteins may play important roles in the development of the local inflammatory changes and the systemic manifestations that characterize syphilis and Lyme disease. PMID:1890308

  12. Freqüência de anticorpos anti-Erhlichia canis, Borrelia burgdorferi e antígenos de Dirofilaria immitis em cães na microrregião Ilhéus-Itabuna, Bahia, Brasil Frequency of antibodies anti-Ehrlichia canis, Borrelia burgdorferi and Dirofilaria immitis antigens in dogs from microrregion Ilhéus-Itabuna, State of Bahia, Brazil

    Directory of Open Access Journals (Sweden)

    Renata S.A. Carlos

    2007-09-01

    Full Text Available Para avaliação de positividade para antígenos de Dirofilaria immitis, anticorpos anti-Borrelia burgdorferi e anti-Ehrlichia canis foram coletadas 200 amostras de sangue de cães, 100 no município de Ilhéus e 100 no de Itabuna. Foi utilizado o "kit" Snap 3DX (IDEXX Laboratories para realização das sorologias. Não se observou nenhum animal positivo para antígenos de D. immitis. Apenas dois dos cães estavam positivos para anticorpos anti-B. burgdorferi. Do total de amostras analisadas, 72 (36% estavam positivas para anticorpos anti-E. canis, sendo 43 em Ilhéus e 29 em Itabuna (p=0,027.In order to detect the positivity to antigens of Dirofilaria immitis, antibodies anti-Borrelia burgdorferi and anti-Ehrlichia canis, 200 canine blood samples were collected as followed: 100 from the municipality of Ilhéus and 100 from Itabuna, State of Bahia. The kit Snap 3DX (IDEXX Laboratories was used to performe serology. None of the tested animals were positive for antigens of D. immitis. Only two dogs of them were positive for antibodies anti-B. burgdorferi. From all the samples analyzed, 72 (36% were positive for antibodies anti-E. canis, 43 from Ilhéus and 29 from Itabuna (p=0,027.

  13. BB0347, from the lyme disease spirochete Borrelia burgdorferi, is surface exposed and interacts with the CS1 heparin-binding domain of human fibronectin.

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    Robert A Gaultney

    Full Text Available The causative agent of Lyme disease, Borrelia burgdorferi, codes for several known fibronectin-binding proteins. Fibronectin a common the target of diverse bacterial pathogens, and has been shown to be essential in allowing for the development of certain disease states. Another borrelial protein, BB0347, has sequence similarity with these other known fibronectin-binding proteins, and may be important in Lyme disease pathogenesis. Herein, we perform an initial characterization of BB0347 via the use of molecular and biochemical techniques. We found that BB0347 is expressed, produced, and presented on the outer surface of intact B. burgdorferi. We also demonstrate that BB0347 has the potential to be important in Lyme disease progression, and have begun to characterize the nature of the interaction between human fibronectin and this bacterial protein. Further work is needed to define the role of this protein in the borrelial infection process.

  14. Isolation of DNA after Extraction of RNA To Detect the Presence of Borrelia burgdorferi and Expression of Host Cellular Genes from the Same Tissue Sample

    OpenAIRE

    Amemiya, Kei; Schaefer, Henry; Pachner, Andrew R.

    1999-01-01

    We are investigating the neuropathogenesis of Lyme disease caused by Borrelia burgdorferi in a nonhuman primate model. In the past, two separate pieces of tissue had to be used when both analyzing for the presence of the spirochete and examining the host response to infection. We have modified a procedure to purify DNA from the same sample after the extraction of RNA. The remaining material containing the DNA was precipitated, and residual organic reagent was removed prior to deproteinization...

  15. Infectivity of the Highly Transformable BBE02− lp56− Mutant of Borrelia burgdorferi, the Lyme Disease Spirochete, via Ticks

    OpenAIRE

    Jacobs, Mary B.; Norris, Steven J; Kathrine M Phillippi-Falkenstein; Philipp, Mario T.

    2006-01-01

    Infectious Borrelia burgdorferi strains that have increased transformability with the shuttle vector pBSV2 were recently constructed by inactivating the gene encoding BBE02, a putative restriction-modification gene product expressed by the linear plasmid lp25 (Kawabata et al., Infect. Immun. 72:7147-7154, 2004). The absence of the linear plasmid lp56, which carries another putative restriction-modification gene, further enhanced transformation rates. The infectivity of these mutants was asses...

  16. Invasive potential of Borrelia burgdorferi sensu stricto ospC type L strains increases the possible disease risk to humans in the regions of their distribution

    Czech Academy of Sciences Publication Activity Database

    Golovchenko, Maryna; Šíma, Radek; Hajdušek, Ondřej; Grubhoffer, Libor; Oliver, J. H., Jr.; Rudenko, Natalia

    2014-01-01

    Roč. 7, NOV 28 2014 (2014), s. 538. ISSN 1756-3305 R&D Projects: GA ČR GP13-27630P; GA ČR GP13-12816P Institutional support: RVO:60077344 Keywords : B. burgdorferi ospC type * Invasive potential * Lyme disease * Southeastern U.S.A. * Tick vector * Vertebrate host Subject RIV: EC - Immunology Impact factor: 3.430, year: 2014

  17. Prävalenz von hämotrophen Mycoplasma spp., Bartonella spp., Anaplasma phagocytophilum und Borrelia burgdorferi bei Katzen im Raum Berlin/Brandenburg

    OpenAIRE

    Morgenthal, Dinah

    2014-01-01

    Arthropod-borne infectious agents in the cat include Bartonella (B.) henselae, Bartonella (B.) clarridgeiae, Bartonella (B.) quintana, Anaplasma (A.) phagocytophilum and Borrelia (B.) burgdorferi. Moreover infections with Mycoplasma (M.) haemofelis, Candidatus Mycoplasma (C. M.) turicensis and Candidatus Mycoplasma (C. M.) haemominutum occur in the cat. The cat flea (Ctenocephalides felis) is supposed to be the main vector for Mycoplasma spp.; moreover, transmission via blood transfusion and ...

  18. Automated purification of Borrelia burgdorferi s.l. PCR products with KingFisher{sup TM} magnetic particle processor prior to genome sequencing

    Energy Technology Data Exchange (ETDEWEB)

    Maekinen, Johanna E-mail: johanna.makinen@utu.fi; Marttila, Harri; Viljanen, Matti K

    2001-07-01

    Borrelia burgdorferi sensu lato genospecies were differentiated by PCR-based sequencing of the borrelial flagellin gene. To evaluate the usefulness of KingFisher{sup TM} magnetic particle processor in PCR product purification, borrelia PCR products were purified with KingFisher{sup TM} magnetic particle processor prior to cycle sequencing and the quality of the sequence data received was analyzed. KingFisher was found to offer a rapid and reliable alternative for borrelial PCR product purification.

  19. Automated purification of Borrelia burgdorferi s.l. PCR products with KingFisher™ magnetic particle processor prior to genome sequencing

    Science.gov (United States)

    Mäkinen, Johanna; Marttila, Harri; Viljanen, Matti K.

    2001-01-01

    Borrelia burgdorferi sensu lato genospecies were differentiated by PCR-based sequencing of the borrelial flagellin gene. To evaluate the usefulness of KingFisher™ magnetic particle processor in PCR product purification, borrelia PCR products were purified with KingFisher™ magnetic particle processor prior to cycle sequencing and the quality of the sequence data received was analyzed. KingFisher was found to offer a rapid and reliable alternative for borrelial PCR product purification.

  20. Complement factor H-related proteins CFHR2 and CFHR5 represent novel ligands for the infection-associated CRASP proteins of Borrelia burgdorferi.

    Directory of Open Access Journals (Sweden)

    Corinna Siegel

    Full Text Available BACKGROUND: One virulence property of Borrelia burgdorferi is its resistance to innate immunity, in particular to complement-mediated killing. Serum-resistant B. burgdorferi express up to five distinct complement regulator-acquiring surface proteins (CRASP which interact with complement regulator factor H (CFH and factor H-like protein 1 (FHL1 or factor H-related protein 1 (CFHR1. In the present study we elucidate the role of the infection-associated CRASP-3 and CRASP-5 protein to serve as ligands for additional complement regulatory proteins as well as for complement resistance of B. burgdorferi. METHODOLOGY/PRINCIPAL FINDINGS: To elucidate whether CRASP-5 and CRASP-3 interact with various human proteins, both borrelial proteins were immobilized on magnetic beads. Following incubation with human serum, bound proteins were eluted and separated by Glycine-SDS-PAGE. In addition to CFH and CFHR1, complement regulators CFHR2 and CFHR5 were identified as novel ligands for both borrelial proteins by employing MALDI-TOF. To further assess the contributions of CRASP-3 and CRASP-5 to complement resistance, a serum-sensitive B. garinii strain G1 which lacks all CFH-binding proteins was used as a valuable model for functional analyses. Both CRASPs expressed on the B. garinii outer surface bound CFH as well as CFHR1 and CFHR2 in ELISA. In contrast, live B. garinii bound CFHR1, CFHR2, and CFHR5 and only miniscute amounts of CFH as demonstrated by serum adsorption assays and FACS analyses. Further functional analysis revealed that upon NHS incubation, CRASP-3 or CRASP-5 expressing borreliae were killed by complement. CONCLUSIONS/SIGNIFICANCE: In the absence of CFH and the presence of CFHR1, CFHR2 and CFHR5, assembly and integration of the membrane attack complex was not efficiently inhibited indicating that CFH in co-operation with CFHR1, CFHR2 and CFHR5 supports complement evasion of B. burgdorferi.

  1. Subjective health complaints are not associated with tick bites or antibodies to Borrelia burgdorferi sensu lato in blood donors in western Norway: a cross-sectional study

    OpenAIRE

    2015-01-01

    Background There is controversy about chronic health consequences of tick-borne infections, especially Lyme borreliosis. This study aims to assess whether general function, physical fitness and subjective health complaints are associated with tick bites or antibodies to Borrelia burgdorferi sensu lato in blood donors. Methods Sera from 1,213 blood donors at four different blood banks in Sogn and Fjordane county in western Norway were obtained during January to June 2010, and analysed for s...

  2. Subjective health complaints are not associated with tick bites or antibodies to Borrelia burgdorferi sensu lato in blood donors in western Norway: a cross-sectional study

    OpenAIRE

    Hjetland, Reidar; Reiso, Harald; Ihlebæk, Camilla; Nilsen, Roy M; Grude, Nils; Ulvestad, Elling

    2015-01-01

    Background There is controversy about chronic health consequences of tick-borne infections, especially Lyme borreliosis. This study aims to assess whether general function, physical fitness and subjective health complaints are associated with tick bites or antibodies to Borrelia burgdorferi sensu lato in blood donors. Methods Sera from 1,213 blood donors at four different blood banks in Sogn and Fjordane county in western Norway were obtained during January to June 2010, and analysed for spec...

  3. Subjective health complaints are not associated with tick bites or antibodies to Borrelia burgdorferi sensu lato in blood donors in western Norway: a cross-sectional study

    OpenAIRE

    Hjetland, Reidar; Reiso, Harald; Ihlebæk, Camilla; Nilsen, Roy Miodini; Grude, Nils; Ulvestad, Elling

    2015-01-01

    Background: There is controversy about chronic health consequences of tick-borne infections, especially Lyme borreliosis. This study aims to assess whether general function, physical fitness and subjective health complaints are associated with tick bites or antibodies to Borrelia burgdorferi sensu lato in blood donors. Methods: Sera from 1,213 blood donors at four different blood banks in Sogn and Fjordane county in western Norway were obtained during January to June 2010, and analysed for...

  4. Borrelia carolinensis sp. nov., a new (14th) member of the Borrelia burgdorferi Sensu Lato complex from the southeastern region of the United States

    Czech Academy of Sciences Publication Activity Database

    Rudenko, Natalia; Golovchenko, Maryna; Grubhoffer, Libor; Oliver, J. H., Jr.

    2009-01-01

    Roč. 47, č. 1 (2009), s. 134-141. ISSN 0095-1137 R&D Projects: GA MŠk(CZ) LC06009; GA ČR(CZ) GA524/06/1479 Institutional research plan: CEZ:AV0Z60220518 Keywords : multilocus sequence analysis * B. burgdorferi sl complex * new borrelia species * Borrelia carolinensis Subject RIV: GJ - Animal Vermins ; Diseases, Veterinary Medicine Impact factor: 4.162, year: 2009

  5. Tick saliva affects both proliferation and distribution of Borrelia burgdorferi spirochetes in mouse organs and increases transmission of spirochetes to ticks

    Czech Academy of Sciences Publication Activity Database

    Horká, Helena; Černá-Kýčková, Kateřina; Skallová, Anna; Kopecký, Jan

    2009-01-01

    Roč. 299, č. 5 (2009), s. 373-380. ISSN 1438-4221 R&D Projects: GA AV ČR IAA600960811; GA MŠk(CZ) LC06009 Institutional research plan: CEZ:AV0Z60220518 Keywords : Borrelia burgdorferi * Ixodes ricinus * saliva-activated transmission * real -time PCR Subject RIV: EC - Immunology Impact factor: 2.802, year: 2009

  6. Detection of four species of Borrelia burgdorferi sensu lato in Ixodes ricinus ticks collected from roe deer (Capreolus capreolus) in The Netherlands.

    OpenAIRE

    Rijpkema, S G; Herbes, R. G.; Verbeek-De Kruif, N.; Schellekens, J. F.

    1996-01-01

    Roe deer (Capreolus capreolus) were investigated for their value as sentinel animals for Lyme borreliosis in the Netherlands. Serum was obtained from 114 roe deer, and 513 Ixodes ricinus, predominantly females (72%), were obtained from 47 animals (41%). The polymerase chain reaction was used to detect DNA of Borrelia burgdorferi sensu lato in a total of 190 ticks, comprising 106 engorged ticks and 84 non-engorged ticks. Borrelia DNA was detected in 24 engorged ticks (23%) and 26 non-engorged ...

  7. Automated purification of Borrelia burgdorferi s.l. PCR products with KingFisherTM magnetic particle processor prior to genome sequencing

    International Nuclear Information System (INIS)

    Borrelia burgdorferi sensu lato genospecies were differentiated by PCR-based sequencing of the borrelial flagellin gene. To evaluate the usefulness of KingFisherTM magnetic particle processor in PCR product purification, borrelia PCR products were purified with KingFisherTM magnetic particle processor prior to cycle sequencing and the quality of the sequence data received was analyzed. KingFisher was found to offer a rapid and reliable alternative for borrelial PCR product purification

  8. Immunochemical characterization of and isolation of the gene for a Borrelia burgdorferi immunodominant 60-kilodalton antigen common to a wide range of bacteria

    DEFF Research Database (Denmark)

    Hansen, K; Bangsborg, Jette Marie; Fjordvang, H;

    1988-01-01

    . burgdorferi CA was localized on a 2.3-kilobase fragment of the plasmid pKH1. CA may have pathogenetic implications in Lyme borreliosis, since the CA of mycobacteria recently has been shown to play a role in the etiology of experimental autoimmune arthritis. The extensive cross-reactivity of this antigen may...... account for the low diagnostic specificity of the currently used serological tests in Lyme borreliosis....

  9. The Nucleotide Excision Repair System of Borrelia burgdorferi Is the Sole Pathway Involved in Repair of DNA Damage by UV Light

    OpenAIRE

    Hardy, Pierre-Olivier; Chaconas, George

    2013-01-01

    To survive and avoid accumulation of mutations caused by DNA damage, the genomes of prokaryotes encode a variety of DNA repair pathways most well characterized in Escherichia coli. Some of these are required for the infectivity of various pathogens. In this study, the importance of 25 DNA repair/recombination genes for Borrelia burgdorferi survival to UV-induced DNA damage was assessed. In contrast to E. coli, where 15 of these genes have an effect on survival of UV irradiation, disruption of...

  10. Mechanism of infection transmission and pathogenesis of Borrelia burgdorferi%莱姆病螺旋体的转移感染和致病机制

    Institute of Scientific and Technical Information of China (English)

    郝琴; 万康林; 徐建国

    2011-01-01

    本文主要就莱姆病螺旋体从蜱到宿主动物的转移感染以及在宿主体内存活并致病的机制进行了的阐述,包括螺旋体在蜱内定居以及感染宿主动物过程中蛋白的变化及作用;螺旋体在宿主体内致病的各种机制(病原体本身的作用、免疫逃避、细胞因子的作用、自身免疫).%The paper describes the mechanism of transmission of Borrelia burgdorferi from ticks to host animals and pathogenesis in host animals, including the colonizing of B. Burgdorferi in ticks, the change and role of its proteins in infecting host animals and all the pathogenic mechanisms of B. Burgdorferi in host animals (self role of pathogen, immune evasion, function of cytokines and autoimmunity).

  11. Immunohistochemistry and real-time PCR as diagnostic tools for detection of Borrelia burgdorferi sensu lato in ticks collected from humans.

    Science.gov (United States)

    Briciu, Violeta T; Sebah, Daniela; Coroiu, Georgiana; Lupşe, Mihaela; Cârstina, Dumitru; Ţăţulescu, Doina F; Mihalca, Andrei D; Gherman, Călin M; Leucuţa, Daniel; Meyer, Fabian; Hizo-Teufel, Cecilia; Fingerle, Volker; Huber, Ingrid

    2016-05-01

    The objective of this study was to evaluate different methods used for detection of Borrelia burgdorferi sensu lato (s.l.) in ticks: immunohistochemistry followed by focus floating microscopy (FFM) and real-time polymerase chain reaction (real-time PCR) targeting the ospA and hbb genes. Additionally, an optimized ospA real-time PCR assay was developed with an integrated internal amplification control (IAC) for the detection of inhibition in the PCR assay and was validated as an improved screening tool for B. burgdorferi. One hundred and thirty-six ticks collected from humans in a hospital from Cluj-Napoca, Romania, were investigated regarding genus, stage of development and sex, and then tested by all three assays. A poor quality of agreement was found between FFM and each of the two real-time PCR assays, as assessed by concordance analysis (Cohen's kappa), whereas the agreement between the two real-time PCR assays was moderate. The present study argues for a low sensitivity of FFM and underlines that discordant results of different assays used for detection of B. burgdorferi in ticks are frequent. PMID:26801157

  12. Production of reactive oxygen species and expression of inducible nitric oxide synthase in rat isolated Kupffer cells stimulated by Leptospira interrogans and Borrelia burgdorferi

    Institute of Scientific and Technical Information of China (English)

    Antonella Marangoni; Silvia Accardo; Rita Aldini; Massimo Guardigli; Francesca Cavrini; Vittorio Sambri; Marco Montagnani; Aldo Roda; Roberto Cevenini

    2006-01-01

    AIM: To evaluate the production of reactive oxygen species (ROS) and the expression of indudble nitric oxide synthase (iNOS) in rat isolated Kupffer cells (KCs) stimulated by Leptospira interrogans and Borrelia burgdorferi.METHODS: Rat Kupffer cells were separated by perfusion of the liver with 0.05% collagenase, and purified by Percoll gradients. Purified Kupffer cells were tested in vitro with alive L.interogans and B. burgdorferi preparations. The production of ROS was determined by chemiluminescence, whereas iNOS protein expression was evaluated by Western blot assay using anti-iNOS antibodies.RESULTS: B. burgdorferi and to a less extent L. interrogans induced ROS production with a peak 35 min after infection. The chemiluminescence signal progressively diminished and was undetectable by 180 min of incubation. Leptospirae and borreliae induced an increased iNOS expression in Kupffer cells that peaked at 6 hours and was still evident 22 h after infection.CONCLUSION: Both genera of spirochetes induced ROS and iNOS production in rat Kupffer cells. Since the cause of liver damage both in leptospiral as well as in borrelial infections are still unknown, we suggest that leptospira and borrelia damage of the liver can be initially mediated by oxygen radicals, and is then maintained at least in part by nitric oxide.

  13. Serological survey of Borrelia burgdorferi sensu lato, Anaplasma phagocytophilum, and Ehrlichia canis infections in rural and urban dogs in Central Italy

    Directory of Open Access Journals (Sweden)

    Valentina Virginia Ebani

    2014-11-01

    Full Text Available [b]Introduction[i][/i][/b][i]. Borrelia burgdorferi [/i]sensu lato (s.l. and Anaplasma phagocytophilum are well known zoonotic pathogens, whereas[i] Ehrlichia canis[/i] is usually considered to be of veterinary concern, although on the basis of recent reports it also seems to be able to infect humans. [b]objective[/b]. The aim of the study was to determine the seroprevalence of [i]B. burgdorferi [/i]s.l., A. phagocytophilum and [i]E. canis[/i] in an Italian canine population, and to verify if there are differences between dogs living in urban areas and those from a rural environment. [b]materials and method.[/b] Blood sera of 1,965 dogs, 1,235 from cities and 730 from rural areas, were tested by indirect immunofluorescent assay (IFAT. [b]results[/b]. The overall seroprevalence was highest for E. canis (7.07%, followed by [i]A. phagocytophilum[/i] (4.68%, and [i]B. burgdorferi[/i] s.l. (1.47%. Rural dogs showed the highest seroprevalence to [i]B. burgdorferi[/i] s.l. and [i]A. phagocytophilum[/i]. No significant differences were observed between rural and urban [i]E. canis[/i]-positive dogs. A low percentage (1.32% of dogs with dual seropositivity was detected, and no triple positive reactions were observed. No significant differences were detected in the seroprevalence of the three agents in relationship to the age and gender of the dogs. Seroprevalence in the five years considered were not statistically different, except for the lowest rate for [i]E. canis[/i] observed in 2012. [b]conclusions[/b]. The results confirm the presence of [i]B. burgdorferi[/i] s.l., [i]A. phagocytophilum[/i] and [i]E. canis[/i] in Italian dogs in both urban and rural areas. Monitoring pet dogs, which share the same environment with their owners, is useful for identifying the presence of tick-borne disease agents of both veterinary and public health significance

  14. Investigation of the genes involved in antigenic switching at the vlsE locus in Borrelia burgdorferi: an essential role for the RuvAB branch migrase.

    Directory of Open Access Journals (Sweden)

    Ashley R Dresser

    2009-12-01

    Full Text Available Persistent infection by pathogenic organisms requires effective strategies for the defense of these organisms against the host immune response. A common strategy employed by many pathogens to escape immune recognition and clearance is to continually vary surface epitopes through recombinational shuffling of genetic information. Borrelia burgdorferi, a causative agent of Lyme borreliosis, encodes a surface-bound lipoprotein, VlsE. This protein is encoded by the vlsE locus carried at the right end of the linear plasmid lp28-1. Adjacent to the expression locus are 15 silent cassettes carrying information that is moved into the vlsE locus through segmental gene conversion events. The protein players and molecular mechanism of recombinational switching at vlsE have not been characterized. In this study, we analyzed the effect of the independent disruption of 17 genes that encode factors involved in DNA recombination, repair or replication on recombinational switching at the vlsE locus during murine infection. In Neisseria gonorrhoeae, 10 such genes have been implicated in recombinational switching at the pilE locus. Eight of these genes, including recA, are either absent from B. burgdorferi, or do not show an obvious requirement for switching at vlsE. The only genes that are required in both organisms are ruvA and ruvB, which encode subunits of a Holliday junction branch migrase. Disruption of these genes results in a dramatic decrease in vlsE recombination with a phenotype similar to that observed for lp28-1 or vls-minus spirochetes: productive infection at week 1 with clearance by day 21. In SCID mice, the persistence defect observed with ruvA and ruvB mutants was fully rescued as previously observed for vlsE-deficient B. burgdorferi. We report the requirement of the RuvAB branch migrase in recombinational switching at vlsE, the first essential factor to be identified in this process. These findings are supported by the independent work of Lin et

  15. Detailed analysis of sequence changes occurring during vlsE antigenic variation in the mouse model of Borrelia burgdorferi infection.

    Directory of Open Access Journals (Sweden)

    Loïc Coutte

    2009-02-01

    Full Text Available Lyme disease Borrelia can infect humans and animals for months to years, despite the presence of an active host immune response. The vls antigenic variation system, which expresses the surface-exposed lipoprotein VlsE, plays a major role in B. burgdorferi immune evasion. Gene conversion between vls silent cassettes and the vlsE expression site occurs at high frequency during mammalian infection, resulting in sequence variation in the VlsE product. In this study, we examined vlsE sequence variation in B. burgdorferi B31 during mouse infection by analyzing 1,399 clones isolated from bladder, heart, joint, ear, and skin tissues of mice infected for 4 to 365 days. The median number of codon changes increased progressively in C3H/HeN mice from 4 to 28 days post infection, and no clones retained the parental vlsE sequence at 28 days. In contrast, the decrease in the number of clones with the parental vlsE sequence and the increase in the number of sequence changes occurred more gradually in severe combined immunodeficiency (SCID mice. Clones containing a stop codon were isolated, indicating that continuous expression of full-length VlsE is not required for survival in vivo; also, these clones continued to undergo vlsE recombination. Analysis of clones with apparent single recombination events indicated that recombinations into vlsE are nonselective with regard to the silent cassette utilized, as well as the length and location of the recombination event. Sequence changes as small as one base pair were common. Fifteen percent of recovered vlsE variants contained "template-independent" sequence changes, which clustered in the variable regions of vlsE. We hypothesize that the increased frequency and complexity of vlsE sequence changes observed in clones recovered from immunocompetent mice (as compared with SCID mice is due to rapid clearance of relatively invariant clones by variable region-specific anti-VlsE antibody responses.

  16. Comparison of Growth of Borrelia afzelii, Borrelia garinii, and Borrelia burgdorferi Sensu Stricto at Five Different Temperatures

    Science.gov (United States)

    Veinović, Gorana; Ružić-Sabljić, Eva; Strle, Franc; Cerar, Tjaša

    2016-01-01

    Lyme borreliosis is caused by the spirochete Borrelia burgdorferi sensu lato, a fastidious bacterium that replicates slowly and requires special conditions to grow in the laboratory. Borrelia isolation from clinical material is a golden standard for microbiological diagnosis of borrelial infection. Important factors that affect in vitro borrelia growth are temperature of incubation and number of borrelia cells in the sample. The aim of the study was to assess the influence of temperature on borrelia growth and survival by evaluation and comparison of growth of 31 different borrelia strains at five different temperatures and to determine the influence of different inoculums on borrelia growth at different temperatures. Borreliae were cultured in the MKP medium; the initial and final number of spirochetes was determined by dark field microscopy using Neubauer counting chamber. The growth of borrelia was defined as final number of cells/mL after three days of incubation. For all three Borrelia species, the best growth was found at 33°C, followed by 37, 28, and 23°C, while no growth was detected at 4°C (Pburgdorferi sensu stricto at 28, 33, and 37°C (P>0.05), respectively. Inoculum had statistically significant influence on growth of all three Borrelia species at all tested temperatures except at 4°C. PMID:27310556

  17. Growth inhibiting activity of volatile oil from Cistus creticus L. against Borrelia burgdorferi s.s. in vitro.

    Science.gov (United States)

    Hutschenreuther, A; Birkemeyer, C; Grötzinger, K; Straubinger, R K; Rauwald, H W

    2010-04-01

    Borreliosis patients from self-help groups reported considerable pain relief after ingestion of Cistus creticus leaf preparations. C. creticus leaf extracts of different polarities such as aqueous, ethyl acetate, hexane extracts as well as the volatile oil fraction obtained by steam distillation were tested for their antibacterial activity against Borrelia burgdorferi sensu stricto (Bbss) in vitro using the antibiotic amoxicilline as standard and polysorbate 80 as solubilizer for lipophilic extracts. Comparison of the four plant preparations shows that the volatile oil exerts the strongest growth inhibitory effect. Even concentrations of 0.02% (w/v) volatile oil in cultivation media reduced the total number of bacteria to 2% in comparison to a growth control after an eight-day cultivation period. While the aqueous extract did not reduce bacterial growth, incubation with hexane and ethyl acetate extracts clearly inhibited microbial growth. The main volatile components of the three active extracts tested were analyzed by GC-MS. The number of different labdane-type diterpenes as well as the total relative amount of diterpenes in the samples tested was highest in the essential oil of C. creticus. Identification of ten different volatile labdane-type diterpenes was assigned to the essential oil of C. creticus. Among these, manoyl oxide, 13-epi-manoyl oxide, 3-acetoxy-manoyl oxide and the monoterpene carvacrol were determined to be major constituents, accompanied by minor amounts of 3-hydroxy-manoyl oxide, all of which are known to exert antimicrobial activity. PMID:20432627

  18. Detection of anti-Borrelia burgdorferi antibodies in buffaloes (Bubalus bubalis in the state of Pará, Brazil Detecção de anticorpos anti-Borrelia burgdorferi em búfalos (Bubalus bubalis no estado do Pará, Brasil

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    Fabíola do Nascimento Corrêa

    2012-09-01

    Full Text Available This study aimed to investigate the frequency of homologous antibodies of IgG class against Borrelia burgdorferi in buffaloes in the state of Pará, Brazil. Blood serum samples from 491 buffaloes were analyzed by means of the indirect ELISA test, using crude antigen produced from a cultivar of the North American strain G39/40 of B. burgdorferi. There were 412 positive samples (83.91%, and there was no statistically significant difference in the proportions of positive animals between the 81.69% (232/284 originating from Marajó Island and the 86.96% (180/207 from the continental area of the state of Pará. In all the municipalities studied, the frequency of positive findings of antibodies against B. burgdorferi among the animals ranged from 63.6% to 92.9%. The high numbers of seropositive animals can be explained by the frequent presence of the tick Rhipicephalus (Boophilusmicroplus, and by the possible existence of spirochetes of the genus Borrelia infecting buffaloes in the region studied, although specific studies are needed to confirm this relationship. These factors suggest that a cross-reaction exists between the North American strain G39/40 of B. burgdorferi, which is used as an antigenic substrate, and the species of Borrelia spp. that possibly infects buffaloes in the state of Pará.Este estudo teve como objetivo investigar a frequência de anticorpos homólogos da classe IgG contra Borrelia burgdorferi em búfalos do estado do Pará. Amostras de soro de 491 búfalos foram analisadas por meio do teste ELISA indireto, utilizando antígeno bruto produzido a partir do cultivo da cepa norte americana G39/40 de B. burgdorferi. Foram encontrados 412 soros positivos (83,91%, não havendo diferença estatística significativa entre os 81,69% (232/284 animais positivos provenientes da Ilha de Marajó e os 86,96% (180/207 da base continental do estado do Pará. Em todos os municípios estudados os animais apresentaram frequência de anticorpos

  19. Functional study of Treponema pallidum genes using Borrelia burgdorferi as a surrogate system%以伯氏疏螺旋体为载体菌研究梅毒螺旋体的基因功能

    Institute of Scientific and Technical Information of China (English)

    尹燕萍; 史玢; 唐志德; 楼永良; 杨晓峰

    2015-01-01

    目的:利用体外可培养的伯氏疏螺旋体作为载体菌,将梅毒螺旋体的基因转入相应的伯氏疏螺旋体菌株进行功能性表达,进而对梅毒螺旋体的基因功能进行研究。方法构建一个携带梅毒螺旋体基因tp0111的大肠埃希菌-伯氏疏螺旋体穿梭质粒,利用电转化法,将质粒转入相应的伯氏疏螺旋体菌株中,通过观察伯氏疏螺旋体的表型和相关基因表达变化,来研究梅毒螺旋体的基因功能。结果成功将梅毒螺旋体基因tp0111转入伯氏疏螺旋体rpoN突变株内,一定程度上回补了伯氏疏螺旋体突变株的表型缺陷。结论首次证明tp0111是梅毒螺旋体的rpoN基因,同时验证了伯氏疏螺旋体可以作为载体来研究梅毒螺旋体的致病因子及其基因调控系统。%Objective To employ Borrelia burgdorferi( B. burgdorferi) , a culturable and genetical-ly transformable spirochete, as a surrogate system to study Treponema pallidum ( T. pallidum) gene function. Methods Bioinformatic analysis revealed that the T. pallidum gene tp0111 encodes the putative sigma factor RpoN. We constructed a B. burgdorferi shuttle vector harboring tp0111. The shuttle vector was then trans-formed into the B. burgdorferi rpoN mutant strain. The phenotype of the resulting B. burgdorferi strain was then determined. Results We successfully constructed the B. burgdorferi rpoN mutant carrying the T. palli-dum gene tp0111. We found that tp0111 could partially complement the B. burgdorferi rpoN mutant. Con-clusion This work provides the first experimental evidence showing that tp0111 is the rpoN gene of T. palli-dum. It also demonstrates that B. burgdorferi can be used as a surrogate system for studying T. pallidum gene function.

  20. Evaluation of antibodies production against Borrelia burgdorferi in cattle submitted to rBm86 protein Boophilus microplus tick immunization and associated challenges influence Avaliação da produção de anticorpos anti Borrelia burgdorferi em bovinos submetidos à imunização com proteína rBm86 de carrapato Boophilus microplus e influência dos desafios associados

    Directory of Open Access Journals (Sweden)

    Márcia Mayumi Ishikawa

    2003-11-01

    Full Text Available IgG antibodies production against Borrelia burgdorferi in immunized cattle with rBm86 protein from Boophilus microplus was evaluated as well as the influence of the association between immunizations and stress through indirect ELISA test during one year. In the present study there was no influence of the isolated challenged used on the production of IgG antibodies against B. burgdorferi. The rBm86 immunogen did not cause significant oscillation in the production of IgG antibodies against B. burgdorferi capable to interfere in the serological results for Lyme Borreliosis in cattle. This study demonstrated the possibility of transitory changes in the production of antibodies after the association of vaccine stimuli and stress, emphasizing the necessity of serological studies combined with epidemiological and management data.Avaliou-se a produção de anticorpos da classe Ig-G anti Borrelia burgdorferi em bovinos imunizados com proteína recombinante Bm86 de Boophilus microplus, assim como a influência de imunizações e estresse associados por meio do teste ELISA indireto no período de um ano. Não houve interferência na produção de anticorpos IgG anti B. burgdorferi pelos desafios utilizados isoladamente no presente estudo. O imunógeno rBm86 não causou oscilações significantes na produção de anticorpos IgG anti B. burgdorferi capazes de interferir nos resultados sorológicos para Borreliose de Lyme em bovinos. O estudo demonstrou a possibilidade de alterações transitórias na produção de anticorpos após estímulos vacinais e de estresse associados, ressaltando a necessidade de estudos sorológicos em conjunto a dados epidemiológicos e de manejo.

  1. Retrospective analysis of clinical and laboratory findings in hunting dogs with serologic reactions to tick-borne pathogens (Anaplasma phagocytophilum, Borrelia burgdorferi, Babesia canis, Ehrlichia canis, Ricketsia conorii

    Directory of Open Access Journals (Sweden)

    Spasojević-Kosić Ljubica

    2015-01-01

    Full Text Available Seroprevalence of tick-borne infections in endemic areas could be high. In this study, we investigated the seroprevalence of tick-borne pathogens (Anaplasma phagocytophilum, Borrelia burgdorferi, Babesia canis, Ehrlichia canis, Rickettsia conorii in hunting dogs, naturally infected with one or more pathogens. Serological test results of the investigated animals were compared to those from clinical examination, as well as from haematological and biochemical analyses. A total of 74.14% dogs were seropositive (R.conorii 44.83%, B. canis 32.76%, B. burgdorferi 25.86%, E. canis 13.79%, A. phagocytophilum 8.47%, with 25.86% of dogs seropositive to two pathogens, 15.52% seropositive to three pathogens, and 1.72% of dogs seropositive to four pathogens. Among all registered clinical signs, only pyrexia (p<0.05 and arrhythmia (p<0.05 were significant in seropositive dogs. There was no significant difference between seropositive and seronegative dogs regarding the majority of haematological and biochemical parameters. Statistically significant difference was registered for particular haematological (number of red blood cells and seroreactivity to B. burgdorferi and biochemical parameters (albumin concentration and seroreactivity to E. canis, and AST and seroreactivity to R. conorii but these values were not clinically significant. The high exposure to tick-borne pathogens suggests that ectoparasitic profilactic treatment is not adequate in examined population of hunting dogs. Clinical finding of pyrexia need to be further investigated and explained etiologically, which means that molecular diagnosis should be used in order to identify larger number of pathogens because of the possibility of coinfection. [Projekat Ministarstva nauke Republike Srbije, br. TR 31084

  2. Two Different Virulence-Related Regulatory Pathways in Borrelia burgdorferi Are Directly Affected by Osmotic Fluxes in the Blood Meal of Feeding Ixodes Ticks.

    Science.gov (United States)

    Bontemps-Gallo, Sébastien; Lawrence, Kevin; Gherardini, Frank C

    2016-08-01

    Lyme disease, caused by Borrelia burgdorferi, is a vector-borne illness that requires the bacteria to adapt to distinctly different environments in its tick vector and various mammalian hosts. Effective colonization (acquisition phase) of a tick requires the bacteria to adapt to tick midgut physiology. Successful transmission (transmission phase) to a mammal requires the bacteria to sense and respond to the midgut environmental cues and up-regulate key virulence factors before transmission to a new host. Data presented here suggest that one environmental signal that appears to affect both phases of the infective cycle is osmolarity. While constant in the blood, interstitial fluid and tissue of a mammalian host (300 mOsm), osmolarity fluctuates in the midgut of feeding Ixodes scapularis. Measured osmolarity of the blood meal isolated from the midgut of a feeding tick fluctuates from an initial osmolarity of 600 mOsm to blood-like osmolarity of 300 mOsm. After feeding, the midgut osmolarity rebounded to 600 mOsm. Remarkably, these changes affect the two independent regulatory networks that promote acquisition (Hk1-Rrp1) and transmission (Rrp2-RpoN-RpoS) of B. burgdorferi. Increased osmolarity affected morphology and motility of wild-type strains, and lysed Hk1 and Rrp1 mutant strains. At low osmolarity, Borrelia cells express increased levels of RpoN-RpoS-dependent virulence factors (OspC, DbpA) required for the mammalian infection. Our results strongly suggest that osmolarity is an important part of the recognized signals that allow the bacteria to adjust gene expression during the acquisition and transmission phases of the infective cycle of B. burgdorferi. PMID:27525653

  3. Co-infection of blacklegged ticks with Babesia microti and Borrelia burgdorferi is higher than expected and acquired from small mammal hosts.

    Directory of Open Access Journals (Sweden)

    Michelle H Hersh

    Full Text Available Humans in the northeastern and midwestern United States are at increasing risk of acquiring tickborne diseases--not only Lyme disease, but also two emerging diseases, human granulocytic anaplasmosis and human babesiosis. Co-infection with two or more of these pathogens can increase the severity of health impacts. The risk of co-infection is intensified by the ecology of these three diseases because all three pathogens (Borrelia burgdorferi, Anaplasma phagocytophilum, and Babesia microti are transmitted by the same vector, blacklegged ticks (Ixodes scapularis, and are carried by many of the same reservoir hosts. The risk of exposure to multiple pathogens from a single tick bite and the sources of co-infected ticks are not well understood. In this study, we quantify the risk of co-infection by measuring infection prevalence in 4,368 questing nymphs throughout an endemic region for all three diseases (Dutchess County, NY to determine if co-infections occur at frequencies other than predicted by independent assortment of pathogens. Further, we identify sources of co-infection by quantifying rates of co-infection on 3,275 larval ticks fed on known hosts. We find significant deviations of levels of co-infection in questing nymphs, most notably 83% more co-infection with Babesia microti and Borrelia burgdorferi than predicted by chance alone. Further, this pattern of increased co-infection was observed in larval ticks that fed on small mammal hosts, but not on meso-mammal, sciurid, or avian hosts. Co-infections involving A. phagocytophilum were less common, and fewer co-infections of A. phagocytophilum and B. microti than predicted by chance were observed in both questing nymphs and larvae fed on small mammals. Medical practitioners should be aware of the elevated risk of B. microti/B. burgdorferi co-infection.

  4. Evaluation of antibodies production against Borrelia burgdorferi in cattle submitted to rBm86 protein Boophilus microplus tick immunization and associated challenges influence Avaliação da produção de anticorpos anti Borrelia burgdorferi em bovinos submetidos à imunização com proteína rBm86 de carrapato Boophilus microplus e influência dos desafios associados

    OpenAIRE

    Márcia Mayumi Ishikawa; Adivaldo Henrique Fonseca; Natalino Hajime Yoshinari; Ana Luiza Alves Rosa Osório

    2003-01-01

    IgG antibodies production against Borrelia burgdorferi in immunized cattle with rBm86 protein from Boophilus microplus was evaluated as well as the influence of the association between immunizations and stress through indirect ELISA test during one year. In the present study there was no influence of the isolated challenged used on the production of IgG antibodies against B. burgdorferi. The rBm86 immunogen did not cause significant oscillation in the production of IgG antibodies against B. b...

  5. Isolation of DNA after Extraction of RNA To Detect the Presence of Borrelia burgdorferi and Expression of Host Cellular Genes from the Same Tissue Sample

    Science.gov (United States)

    Amemiya, Kei; Schaefer, Henry; Pachner, Andrew R.

    1999-01-01

    We are investigating the neuropathogenesis of Lyme disease caused by Borrelia burgdorferi in a nonhuman primate model. In the past, two separate pieces of tissue had to be used when both analyzing for the presence of the spirochete and examining the host response to infection. We have modified a procedure to purify DNA from the same sample after the extraction of RNA. The remaining material containing the DNA was precipitated, and residual organic reagent was removed prior to deproteinization and extraction of the DNA. This procedure now allows us to both assay for the presence of the Lyme microorganism and analyze the host response in the same tissue preparation. PMID:10325389

  6. Orale Immunisierung mit rekombinanten "Escherichia coli" NISSLE 1917:Charakterisierung der humoralen Immunantwort gegen Oberflächenexprimierte heterologe Antigene aus "Borrelia burgdorferi" und "Listeria monocytogenes"

    OpenAIRE

    Buddenborg, C. (Christian)

    2005-01-01

    Im Rahmen dieser Arbeit wurde ein Lebendvektor-System zur oralen Immunisierung entwickelt, das aus dem apathogenen, probiotischen E. coli Stamm NISSLE 1917 besteht. Mit Hilfe des AIDA-Autotransporters wurden die äußeren Membranproteine OspA und OspG aus Borrelia burgdorferi bzw. p60 aus Listeria monocytogenes auf der Oberfläche von E. coli NISSLE 1917 präsentiert. Nach oraler Immunisierung der Versuchstiere wurden die spezifischen humoralen Immunantworten gegen die verwendeten Antigene in Ser...

  7. Response to Esteve-Gassent et al.: flaB sequences obtained from Texas PCR products are identical to the positive control strain Borrelia burgdorferi B31

    OpenAIRE

    Norris, Steven J; Barbour, Alan G.; Fish, Durland; Diuk-Wasser, Maria A.

    2015-01-01

    Feria-Arroyo et al. had reported previously that, based on PCR analysis, 45 % of Ixodes scapularis ticks collected in Texas and Mexico were infected with the Lyme disease spirochete Borrelia burgdorferi (Parasit. Vectors 2014, 7:199). However, our analyses of their initial data (Parasit. Vectors 2014, 7:467) and a recent response by Esteve-Gassent et al. (Parasit. Vectors 2015, 8:129) provide evidence that the positive PCR results obtained from both ribosomal RNA intergenic sequences and the ...

  8. Diagnostic Value of Proteins of Three Borrelia Species (Borrelia burgdorferi Sensu Lato) and Implications for Development and Use of Recombinant Antigens for Serodiagnosis of Lyme Borreliosis in Europe

    OpenAIRE

    Hauser, Ulrike; Lehnert, Gisela; Wilske, Bettina

    1998-01-01

    More and more assays for the serodiagnosis of Lyme borreliosis (LB) are based on recombinant antigens. However, so far, there is no consensus as to which are the most specific and sensitive proteins and how they should be used in combination to obtain tests with the best discrimination abilities. The present study was preceded by a detailed analysis of Western blots (WB) using whole-cell lysates of Borrelia burgdorferi sensu stricto strain PKa2, B. afzelii PKo, and B. garinii PBi (U. Hauser, ...

  9. Detección de anticuerpos contra Borrelia burgdorferi e identificación de garrapatas ixodidas en Piura Y Amazonas, Perú

    OpenAIRE

    Martha Glenny A; Leonardo Mendoza U; Eduardo Falconí R

    2004-01-01

    Objetivos: Detectar anticuerpos IgG/IgM contra Borrelia burgdorferi en población general, procedentes de los departamentos de Piura y Amazonas e identificar especies de garrapatas probablemente incriminadas en la transmisión de la enfermedad de Lyme. Material y Métodos: Entre agosto del año 2001 y junio de 2002, se colectaron muestras de sangre de 232 pobladores procedentes de ocho localidades del Departamento de Piura y 12 del Departamento de Amazonas, para evaluar mediante ELISA Captia™ Lym...

  10. Human TLR8 is activated upon recognition of Borrelia burgdorferi RNA in the phagosome of human monocytes

    Science.gov (United States)

    Cervantes, Jorge L.; La Vake, Carson J.; Weinerman, Bennett; Luu, Stephanie; O'Connell, Caitlin; Verardi, Paulo H.; Salazar, Juan C.

    2013-01-01

    Phagocytosed Borrelia burgdorferi (Bb), the Lyme disease spirochete, induces a robust and complex innate immune response in human monocytes, in which TLR8 cooperates with TLR2 in the induction of NF-κB-mediated cytokine production, whereas TLR8 is solely responsible for transcription of IFN-β through IRF7. We now establish the role of Bb RNA in TLR8-mediated induction of IFN-β. First, using TLR2-transfected HEK.293 cells, which were unable to phagocytose intact Bb, we observed TLR2 activation by lipoprotein-rich borrelial lysates and TLR2 synthetic ligands but not in response to live spirochetes. Purified Bb RNA, but not borrelial DNA, triggered TLR8 activation. Neither of these 2 ligands induced activation of TLR7. Using purified human monocytes we then show that phagocytosed live Bb, as well as equivalent amounts of borrelial RNA delivered into the phagosome by polyethylenimine (PEI), induces transcription of IFN-β and secretion of TNF-α. The cytokine response to purified Bb RNA was markedly impaired in human monocytes naturally deficient in IRAK-4 and in cells with knockdown TLR8 expression by small interfering RNA. Using confocal microscopy we provide evidence that TLR8 colocalizes with internalized Bb RNA in both early (EEA1) and late endosomes (LAMP1). Live bacterial RNA staining indicates that spirochetal RNA does not transfer from the phagosome into the cytosol. Using fluorescent dextran particles we show that phagosomal integrity in Bb-infected monocytes is not affected. We demonstrate, for the first time, that Bb RNA is a TLR8 ligand in human monocytes and that transcription of IFN-β in response to the spirochete is induced from within the phagosomal vacuole through the TLR8-MyD88 pathway. PMID:23906644

  11. Use of nonelectrolytes reveals the channel size and oligomeric constitution of the Borrelia burgdorferi P66 porin.

    Directory of Open Access Journals (Sweden)

    Iván Bárcena-Uribarri

    Full Text Available In the Lyme disease spirochete Borrelia burgdorferi, the outer membrane protein P66 is capable of pore formation with an atypical high single-channel conductance of 11 nS in 1 M KCl, which suggested that it could have a larger diameter than 'normal' Gram-negative bacterial porins. We studied the diameter of the P66 channel by analyzing its single-channel conductance in black lipid bilayers in the presence of different nonelectrolytes with known hydrodynamic radii. We calculated the filling of the channel with these nonelectrolytes and the results suggested that nonelectrolytes (NEs with hydrodynamic radii of 0.34 nm or smaller pass through the pore, whereas neutral molecules with greater radii only partially filled the channel or were not able to enter it at all. The diameter of the entrance of the P66 channel was determined to be ≤1.9 nm and the channel has a central constriction of about 0.8 nm. The size of the channel appeared to be symmetrical as judged from one-sidedness of addition of NEs. Furthermore, the P66-induced membrane conductance could be blocked by 80-90% by the addition of the nonelectrolytes PEG 400, PEG 600 and maltohexaose to the aqueous phase in the low millimolar range. The analysis of the power density spectra of ion current through P66 after blockage with these NEs revealed no chemical reaction responsible for channel block. Interestingly, the blockage of the single-channel conductance of P66 by these NEs occurred in about eight subconductance states, indicating that the P66 channel could be an oligomer of about eight individual channels. The organization of P66 as a possible octamer was confirmed by Blue Native PAGE and immunoblot analysis, which both demonstrated that P66 forms a complex with a mass of approximately 460 kDa. Two dimension SDS PAGE revealed that P66 is the only polypeptide in the complex.

  12. ErpC, a member of the complement regulator-acquiring family of surface proteins from Borrelia burgdorferi, possesses an architecture previously unseen in this protein family

    International Nuclear Information System (INIS)

    The structure of ErpC, a member of the complement regulator-acquiring surface protein family from B. burgdorferi, has been solved, providing insights into the strategies of complement evasion by this zoonotic bacterium and suggesting a common architecture for other members of this protein family. Borrelia burgdorferi is a spirochete responsible for Lyme disease, the most commonly occurring vector-borne disease in Europe and North America. The bacterium utilizes a set of proteins, termed complement regulator-acquiring surface proteins (CRASPs), to aid evasion of the human complement system by recruiting and presenting complement regulator factor H on its surface in a manner that mimics host cells. Presented here is the atomic resolution structure of a member of this protein family, ErpC. The structure provides new insights into the mechanism of recruitment of factor H and other factor H-related proteins by acting as a molecular mimic of host glycosaminoglycans. It also describes the architecture of other CRASP proteins belonging to the OspE/F-related paralogous protein family and suggests that they have evolved to bind specific complement proteins, aiding survival of the bacterium in different hosts

  13. Use of T7 RNA polymerase to direct expression of outer Surface Protein A (OspA) from the Lyme disease Spirochete, Borrelia burgdorferi

    Science.gov (United States)

    Dunn, John J.; Lade, Barbara N.

    1991-01-01

    The OspA gene from a North American strain of the Lyme disease Spirochete, Borrelia burgdorferi, was cloned under the control of transciption and translation signals from bacteriophage T7. Full-length OspA protein, a 273 amino acid (31kD) lipoprotein, is expressed poorly in Escherichia coli and is associated with the insoluble membrane fraction. In contrast, a truncated form of OspA lacking the amino-terminal signal sequence which normally would direct localization of the protein to the outer membrane is expressed at very high levels (less than or equal to 100 mg/liter) and is soluble. The truncated protein was purified to homogeneity and is being tested to see if it will be useful as an immunogen in a vaccine against Lyme disease. Circular dichroism and fluorescence spectroscopy was used to characterize the secondary structure and study conformational changes in the protein. Studies underway with other surface proteins from B burgdorferi and a related spirochete, B. hermsii, which causes relapsing fever, leads us to conclude that a strategy similar to that used to express the truncated OspA can provide a facile method for producing variations of Borrelia lipoproteins which are highly expressed in E. coli and soluble without exposure to detergents.

  14. Study of a Cohort of 1,886 Persons To Determine Changes in Antibody Reactivity to Borrelia burgdorferi 3 Months after a Tick Bite

    DEFF Research Database (Denmark)

    Dessau, Ram B; Fryland, Linda; Wilhelmsson, Peter;

    2015-01-01

    Lyme borreliosis is a tick-borne disease caused by the bacterium Borrelia burgdorferi. The most frequent clinical manifestation is a rash called erythema migrans. Changes in antibody reactivity to B. burgdorferi 3 months after a tick bite are measured using enzyme-linked immunosorbent assays...... (ELISAs). One assay is based on native purified flagellum antigen (IgG), and the other assay is based on a recombinant antigen called C6 (IgG or IgM). Paired samples were taken at the time of a tick bite and 3 months later from 1,886 persons in Sweden and the Åland Islands, Finland. The seroconversion or...... antigen and the C6 antigen, respectively. Graphical methods to display the antibody response and to choose thresholds for a rise in relative antibody reactivity are shown and discussed. In conclusion, 5.4% of people with tick bites showed a rise in Borrelia-specific antibodies above the 2.5% threshold in...

  15. Detección de anticuerpos contra Borrelia burgdorferi e identificación de garrapatas ixodidas en Piura Y Amazonas, Perú

    Directory of Open Access Journals (Sweden)

    Martha Glenny A

    2004-01-01

    Full Text Available Objetivos: Detectar anticuerpos IgG/IgM contra Borrelia burgdorferi en población general, procedentes de los departamentos de Piura y Amazonas e identificar especies de garrapatas probablemente incriminadas en la transmisión de la enfermedad de Lyme. Material y Métodos: Entre agosto del año 2001 y junio de 2002, se colectaron muestras de sangre de 232 pobladores procedentes de ocho localidades del Departamento de Piura y 12 del Departamento de Amazonas, para evaluar mediante ELISA Captia™ Lyme IgG/IgM (Trinity biotech la presencia de anticuerpos contra Borrelia burgdorferi. Además, se colectaron garrapatas en animales domésticos por búsqueda directa. Resultados: Se detectó seropositividad en 9,9 % de los sueros evaluados. Asimismo, de 433 garrapatas colectadas se identificaron los géneros: Ixodes (5,5%, Amblyomma (18,0%, Rhipicephalus (23,5%, Anocentor (31,1% y Boophilus (21,7%. Conclusiones: Existen personas seropositivas por Borrelia en Piura y Amazonas, coincidiendo con los hallazgos realizados en Sapillica en el año 1992, además se detectó la presencia de garrapatas del género Ixodes en Piura.

  16. Further structural insights into the binding of complement factor H by complement regulator-acquiring surface protein 1 (CspA) of Borrelia burgdorferi

    International Nuclear Information System (INIS)

    B. burgdorferi binds complement factor H using a dimeric surface protein, CspA (BbCRASP-1). Presented here is a new structure of CspA that suggests that there is a degree of flexibility between subunits which may have implications for complement regulator binding. Borrelia burgdorferi has evolved many mechanisms of evading the different immune systems across its range of reservoir hosts, including the capture and presentation of host complement regulators factor H and factor H-like protein-1 (FHL-1). Acquisition is mediated by a family of complement regulator-acquiring surface proteins (CRASPs), of which the atomic structure of CspA (BbCRASP-1) is known and shows the formation of a homodimeric species which is required for binding. Mutagenesis studies have mapped a putative factor H binding site to a cleft between the two subunits. Presented here is a new atomic structure of CspA which shows a degree of flexibility between the subunits which may be critical for factor H scavenging by increasing access to the binding interface and allows the possibility that the assembly can clamp around the bound complement regulators

  17. The function of histidine kinase Ⅱ(Hk2)in the life cycle of Borrelia burgdorferi%组氨酸激酶Ⅱ在伯氏疏螺旋体生活史中的功能

    Institute of Scientific and Technical Information of China (English)

    杨章女; 蒋宝贵; 杨晓峰; 徐海君; 曹务春

    2012-01-01

    目的 伯氏疏螺旋体组氨酸激酶Ⅱ(Hk2)和反应调节蛋白Rrp2共同组成一个二元信号系统,控制病原菌侵染哺乳动物所需致病因子的表达,但Hk2的生物学功能有待验证.方法 应用同源重组方法得到hk2敲除菌株(hk2-),并利用蜱-鼠动物模型对其生物学功能进行探索.结果 hk2-能够通过人工针刺正常感染小鼠,间接免疫荧光试验显示在吸血的幼蜱和若蜱中肠能够检测到hk2-,定量PCR结果显示hk2敲除并不影响病原菌在若蜱中肠的繁殖,但在蜱叮咬状态下只有50%的小鼠能够被hk2-感染.结论 Hk2不影响病原菌从鼠传播到幼蜱及随后在蜱体内的长期寄生,但hk2敲除降低了病原菌在自然条件下(蜱叮咬)感染小鼠的能力,研究结果暗示Hk2在病原菌生活史中的功能是协助病原菌高效地侵染哺乳动物.%Objective To validate the biological function of Hk2, which is reported to be in combination with the cognate response regulator Rrp2 to constitute a two component signal system in Borrelia burgdorferi that controls the key virulence factors required for pathogen invasion in mammals. Methods A hk2 knockout strain (hk2~) was generated through homologous recombination, with the biological function of Hk2 estimated by the mouse-tick animal model. Results The hk2~ knockout strain remained to be able to infect mouse by needle inoculation, and subsequently successfully detected in the midgut of fed-larvae and -nymph by IFA. The quantitative - PCR demonstrated that hk2 knockout had no influence on bacterial replication in the midgut of fed nymph. However, only 50% of tested mice were infected in hk2~ group by tick bite. Conclusion The hk2 knockout does not affect the pathogen acquisition from mouse by larvae ticks and subsequent persistent colonization in tick midgut, but it embarrasses the transmission from nymph to mouse under natural conditions by tick bite. The above data indicate that the Hk2 may effectively

  18. Ribotyping of Borrelia burgdorferi sensu lato in China%中国莱姆病螺旋体的核糖体基因分型研究

    Institute of Scientific and Technical Information of China (English)

    史翠霞; 万康林; 马凤琴; 张哲夫

    2001-01-01

    目的莱姆病螺旋体的基因型和临床表现、疫苗菌株和抗原菌株的选择存在密切的关系,所以对中国菌株进行分子流行病学研究,可为莱姆病的防治提供科学依据。方法 5S~23S rRNA基因间隔区RFLP分析和16+23S rRNA基因RFLP分析。结果中国菌株至少被分为3个基因型(B.burgdorferi sensu stricto、B.garinii和B.afzelii),B.garinii和B.afzelii占优势,B.burgdorferi sensu stricto少见。少数菌株用上述方法尚不能明确其分类地位,需进一步研究,中国很可能存在世界上独特的新基因型。结论中国菌株的基因型明显不同于北美菌株,而同欧洲菌株比较接近。5S~23S rRNA基因间隔区RFLP分析方法简便、快速、准确,是理想的基因型分类方法,可作为国内菌株基因型鉴定的常规方法。%Objective There is a close relationship between genospecies and clinical manifestation, the choice of strain for vaccine and serodiagnosis antigen. So molecular epidemiology of Borrelia burgdorferi sensu lato in China is important for the prevention of Lyme disease. Methods Rrf-rrl intergenic spacer RFLP analysis and 16+23S rRNA gene RFLP analysis. Results There were at least three genospecies in China. The most of them belongs to B. garinii and B. afzelii. A few isolates showed unique RFLP pattern. Their taxonomic positions remain unclear. There are probably new genospecies in China. Conclusions Chinese strains are quite different from that of Northern America and similar to that in Europe. The method of rrf-rrl intergenic spacer RFLP analysis is simple and accurate, so it could be used as routine genotyping method in China.

  19. Establishment of a minor groove binder-probe based quantitative real time PCR to detect Borrelia burgdorferi sensu lato and differentiation of Borrelia spielmanii by ospA-specific conventional PCR

    Directory of Open Access Journals (Sweden)

    Strube Christina

    2010-08-01

    Full Text Available Abstract Background Borrelia burgdorferi sensu lato (sl, the causative agent of Lyme borreliosis, is transmitted by ticks of the genus Ixodes as vector. For identification of Borrelia infections in ticks a TaqMan™ minor groove binder (MGB probe-based quantitative real time PCR (qPCR was established targeting the 5S-23S intergenic spacer. Extension to a duplex qPCR included an Ixodes spp. positive control to verify successful DNA isolation. Besides qPCR, an ospA-specific conventional PCR for species-specific identification of B. spielmanii was established. Afterwards 1000 I. ricinus flagged in the city of Hanover, Germany, were investigated for B. burgdorferi sl infections followed by species identification. Furthermore, I. hexagonus ticks were investigated to proof applicability of the PCRs. Results Quantitative real time PCR (qPCR identifying B. burgdorferi sl in ticks was able to detect 1-10 copies per reaction. B. spielmanii ospA-specific conventional PCR was also highly specific and showed no cross reactions with the other tested Borrelia species. From 1000 hanoveranian ticks 24.3% were positive compared to only 7.4% positives by dark-field microscopy. Related to tick stage 1.7% larvae, 18.1% nymphs, and 34.6% adults were positive. The most frequent species was B. garinii, followed by B. afzelii, B. spielmanii, B. valaisiana and B. burgdorferi sensu stricto (ss. 70.6% of I. ricinus were mono-infected, whereas 28.0% and 1.4% were infected with two and three Borrelia species, respectively. From 232 I. hexagonus collected from hedgehogs in different sites of Germany, qPCR detected 5.7% to be infected with B. burgdorferi sl, which were identified as B. afzelii, B. garinii and B. spielmanii. Conclusions The evaluated qPCR to detect B. burgdorferi sl in Ixodes spp. is highly specific and sensitive. As a duplex qPCR including detection of Ixodes spp. DNA it is the first DNA based technique incorporating a control for successful DNA isolation from

  20. NMR studies of Borrelia burgdorferi OspA, a 28 kDa protein containing a single-layer {beta}-sheet

    Energy Technology Data Exchange (ETDEWEB)

    Pham, Thuy-Nga; Koide, Shohei

    1998-05-15

    The crystal structure of outer surface protein A (OspA) from Borrelia burgdorferi contains a single-layer {beta}-sheet connecting the N- and C-terminal globular domains. The central {beta}-sheet consists largely of polar amino acids and it is solvent-exposed on both faces, which so far appears to be unique among known protein structures. We have accomplished nearly complete backbone H, C and N and C{sup ;}/H{sup {beta}} assignments of OspA (28 kDa) using standard triple resonance techniques without perdeuteration. This was made possible by recording spectra at a high temperature (45 {sup o}C ). The chemical shift index and {sup 15}N T{sub 1}/T{sub 2} ratios show that both the secondary structure and the global conformation of OspA in solution are similar to the crystal structure, suggesting that the unique central {beta}-sheet is fairly rigid.

  1. Borrelia burgdorferi Requires the Alternative Sigma Factor RpoS for Dissemination within the Vector during Tick-to-Mammal Transmission

    Science.gov (United States)

    Dunham-Ems, Star M.; Caimano, Melissa J.; Eggers, Christian H.; Radolf, Justin D.

    2012-01-01

    While the roles of rpoSBb and RpoS-dependent genes have been studied extensively within the mammal, the contribution of the RpoS regulon to the tick-phase of the Borrelia burgdorferi enzootic cycle has not been examined. Herein, we demonstrate that RpoS-dependent gene expression is prerequisite for the transmission of spirochetes by feeding nymphs. RpoS-deficient organisms are confined to the midgut lumen where they transform into an unusual morphotype (round bodies) during the later stages of the blood meal. We show that round body formation is rapidly reversible, and in vitro appears to be attributable, in part, to reduced levels of Coenzyme A disulfide reductase, which among other functions, provides NAD+ for glycolysis. Our data suggest that spirochetes default to an RpoS-independent program for round body formation upon sensing that the energetics for transmission are unfavorable. PMID:22359504

  2. Mapping human risk of infection with Borrelia burgdorferi sensu lato, the agent of Lyme borreliosis, in a periurban forest in France.

    Science.gov (United States)

    Vourc'h, G; Abrial, D; Bord, S; Jacquot, M; Masséglia, S; Poux, V; Pisanu, B; Bailly, X; Chapuis, J-L

    2016-07-01

    Lyme borreliosis is a major zoonosis in Europe, with estimates of over 26,000 cases per year in France alone. The etiological agents are spirochete bacteria that belong to the Borrelia burgdorferi sensu lato (s. l.) complex and are transmitted by hard ticks among a large range of vertebrate hosts. In Europe, the tick Ixodes ricinus is the main vector. In the absence of a vaccine and given the current difficulties to diagnose and treat chronic Lyme syndromes, there is urgent need for prevention. In this context, accurate information on the spatial patterns of risk of exposure to ticks is of prime importance for public health. The objective of our study was to provide a snapshot map of the risk of human infection with B. burgdorferi s. l. pathogens in a periurban forest at a high resolution, and to analyze the factors that contribute to variation in this risk. Field monitoring took place over three weeks in May 2011 in the suburban Sénart forest (3,200ha; southeast of Paris), which receives over 3 million people annually. We sampled ticks over the entire forest area (from 220 forest stands with a total area of 35,200m(2)) and quantified the density of questing nymphs (DON), the prevalence of infection among nymphs (NIP), and the density of infected nymphs (DIN), which is the most important predictor of the human risk of Lyme borreliosis. For each of these response variables, we explored the relative roles of weather (saturation deficit), hosts (abundance indices of ungulates and Tamias sibiricus, an introduced rodent species), vegetation and forest cover, superficial soil composition, and the distance to forest roads. In total, 19,546 questing nymphs were collected and the presence of B. burgdorferi s. l. was tested in 3,903 nymphs by qPCR. The mean DON was 5.6 nymphs per 10m(2) (standard deviation=10.4) with an average NIP of 10.1% (standard deviation=0.11). The highest DIN was 8.9 infected nymphs per 10m(2), with a mean of 0.59 (standard deviation=0.6). Our

  3. Biochemical and biophysical characterization of the major outer surface protein, OSP-A from North American and European isolates of Borrelia burgdorferi

    Energy Technology Data Exchange (ETDEWEB)

    McGrath, B.C.; Dunn, J.J. [Brookhaven National Lab., Upton, NY (United States); France, L.L. [Plum Island Animal Disease Center, Greenport, NY (United States); Jaing, W.; Polin, D.; Gorgone, G.; Luft, B.; Dykhuizen, D. [SUNY at Stony Brook, Stony Brook, NY (United States)

    1995-12-31

    Lyme borreliosis, caused by the spirochete Borrelia burgdorferi, is the most common vector-borne disease in North America and Western Europe. As the major delayed immune response in humans, a better understanding of the major outer surface lipoproteins OspA and OspB are of much interest. These proteins have been shown to exhibit three distinct phylogenetic genotypes based on their DNA sequences. This paper describes the cloning of genomic DNA for each variant and amplification of PCR. DNA sequence data was used to derive computer driven phylogenetic analysis and deduced amino acid sequences. Overproduction of variant OspAs was carried out in E. coli using a T7-based expression system. Circular dichroism and fluorescence studies was carried out on the recombinant B31 PspA yielding evidence supporting a B31 protein containing 11% alpha-helix, 34% antiparallel beta-sheet, 12% parallel beta sheet.

  4. 广西首次分离到莱姆病螺旋体%Borrelia burgdorferi isolated from rat in Yachang forest farm of Guangxi Province

    Institute of Scientific and Technical Information of China (English)

    刘敏; 王树声; 张涛; 曾霞; 杨光华; 王昭孝

    2001-01-01

    Objective To isolate Lyme disease spirochetes from it′ s host-rat in Yachang forest farm of Guangxi Province.Methods The rat's tissues of urinary bladder were inoculated into the BSK-Ⅱ medium.After incubating for 7~ 14 days,the Borrelia burgdorferi was observed in dark-field microscope.Results From these rats,six isolates were obtained.They were named GXLD4,8,9,16,18,20.The positive rate of isolation is 40% (6/15).Conclusion It is the first report that Borrelia burgdorferi was isolated from Guangxi Province.%目的从广西鼠类的膀胱中分离莱姆病螺旋体。方法膀胱组织标本接种 BSK-Ⅱ培养基进行莱姆病病原分离培养。结果从广西雅长林场捕获的 23只野鼠( 8只鼠标本培养污染)中共分离出 6株莱姆病螺旋体,分别命名为 GXLD- 4,8,9,16,18,20,分离阳性率为 40% (6/15)。结论首次从广西莱姆病宿主动物中分离出伯氏螺旋体,证实广西存在莱姆病的流行。

  5. Intravital Imaging of Vascular Transmigration by the Lyme Spirochete: Requirement for the Integrin Binding Residues of the B. burgdorferi P66 Protein.

    Directory of Open Access Journals (Sweden)

    Devender Kumar

    2015-12-01

    Full Text Available Vascular extravasation, a key step in systemic infection by hematogenous microbial pathogens, is poorly understood, but has been postulated to encompass features similar to vascular transmigration by leukocytes. The Lyme disease spirochete can cause a variety of clinical manifestations, including arthritis, upon hematogenous dissemination. This pathogen encodes numerous surface adhesive proteins (adhesins that may promote extravasation, but none have yet been implicated in this process. In this work we report the novel use of intravital microscopy of the peripheral knee vasculature to study transmigration of the Lyme spirochete in living Cd1d-/-mice. In the absence of iNKT cells, major immune modulators in the mouse joint, spirochetes that have extravasated into joint-proximal tissue remain in the local milieu and can be enumerated accurately. We show that BBK32, a fibronectin and glycosaminoglycan adhesin of B. burgdorferi involved in early steps of endothelial adhesion, is not required for extravasation from the peripheral knee vasculature. In contrast, almost no transmigration occurs in the absence of P66, an outer membrane protein that has porin and integrin adhesin functions. Importantly, P66 mutants specifically defective in integrin binding were incapable of promoting extravasation. P66 itself does not promote detectable microvascular interactions, suggesting that vascular adhesion of B. burgdorferi mediated by other adhesins, sets the stage for P66-integrin interactions leading to transmigration. Although integrin-binding proteins with diverse functions are encoded by a variety of bacterial pathogens, P66 is the first to have a documented and direct role in vascular transmigration. The emerging picture of vascular escape by the Lyme spirochete shows similarities, but distinct differences from leukocyte transmigration.

  6. Laimo boreliozės paplitimo Lietuvoje ir ligos sukėlėjo Borrelia burgdorferi s. l. ospA geno sekų analizė

    OpenAIRE

    Juodišiūtė, Indrė

    2014-01-01

    Laimo boreliozė (LB) yra labiausiai paplitusi erkių platinama liga. Ligos sukėlėjus perneša Ixodes rūšies erkės. Didelį borelijų paplitimą lemia platus rezervuarinių šeimininkų ratas. Šį susirgimą gali sukelti kelios B. burgdorferi s. l. komplekso bakterijų rūšys: B. afzelii, B. garinii, B. burgdorferi sensu stricto. Šiame darbe buvo tirtos 134 Ixodes ricinus erkės nuo 8 elninių gyvūnų (4 stirnų ir 4 elnių) ir 73 erkės nuo žolės (elninių teritorijoje). Naudojant dauginės polimerazės gra...

  7. Anti-inflammatory effects of dexamethasone and meloxicam on Borrelia burgdorferi-induced inflammation in neuronal cultures of dorsal root ganglia and myelinating cells of the peripheral nervous system

    OpenAIRE

    Ramesh, Geeta; Meisner, Olivia C.; Philipp, Mario T.

    2015-01-01

    Background Lyme neuroborreliosis (LNB), caused by the spirochete Borrelia burgdorferi (Bb), could result in cognitive impairment, motor dysfunction, and radiculoneuritis. We hypothesized that inflammation is a key factor in LNB pathogenesis and recently evaluated the effects of dexamethasone, a steroidal anti-inflammatory drug, and meloxicam a non-steroidal anti-inflammatory drug (NSAID), in a rhesus monkey model of acute LNB. Dexamethasone treatment significantly reduced the levels of immune...

  8. The Borrelia burgdorferi telomere resolvase, ResT, anneals ssDNA complexed with its cognate ssDNA-binding protein.

    Science.gov (United States)

    Huang, Shu Hui; Kobryn, Kerri

    2016-06-20

    Spirochetes of the genus Borrelia possess unusual genomes that consist in a linear chromosome and multiple linear and circular plasmids. The linear replicons are terminated by covalently closed hairpin ends, referred to as hairpin telomeres. The hairpin telomeres represent a simple solution to the end-replication problem. Deoxyribonucleic acid replication initiates internally and proceeds bidirectionally toward the hairpin telomeres. The telomere resolvase, ResT, forms the hairpin telomeres from replicated telomere intermediates in a reaction with similarities to those promoted by type IB topoisomerases and tyrosine recombinases. ResT has also been shown to possess DNA single-strand annealing activity. We report here that ResT promotes single-strand annealing of both free DNA strands and ssDNA complexed with single-stranded DNA binding protein (SSB). The annealing of complementary strands bound by SSB requires a ResT-SSB interaction that is mediated by the conserved amphipathic C-terminal tail of SSB. These properties of ResT are similar to those demonstrated for the recombination mediator protein, RecO, of the RecF pathway. Borrelia burgdorferi is unusual in lacking identifiable homologs of the RecFOR proteins. We propose that ResT may provide missing RecFOR functions. PMID:27131360

  9. Epitope-Specific Evolution of Human B Cell Responses to Borrelia burgdorferi VlsE Protein from Early to Late Stages of Lyme Disease.

    Science.gov (United States)

    Jacek, Elzbieta; Tang, Kevin S; Komorowski, Lars; Ajamian, Mary; Probst, Christian; Stevenson, Brian; Wormser, Gary P; Marques, Adriana R; Alaedini, Armin

    2016-02-01

    Most immunogenic proteins of Borrelia burgdorferi, the causative agent of Lyme disease, are known or expected to contain multiple B cell epitopes. However, the kinetics of the development of human B cell responses toward the various epitopes of individual proteins during the course of Lyme disease has not been examined. Using the highly immunogenic VlsE as a model Ag, we investigated the evolution of humoral immune responses toward its immunodominant sequences in 90 patients with a range of early to late manifestations of Lyme disease. The results demonstrate the existence of asynchronous, independently developing, Ab responses against the two major immunogenic regions of the VlsE molecule in the human host. Despite their strong immunogenicity, the target epitopes were inaccessible to Abs on intact spirochetes, suggesting a lack of direct immunoprotective effect. These observations document the association of immune reactivity toward specific VlsE sequences with different phases of Lyme disease, demonstrating the potential use of detailed epitope mapping of Ags for staging of the infection, and offer insights regarding the pathogen's possible immune evasion mechanisms. PMID:26718339

  10. Comparative analysis of the infectivity rate of both Borrelia burgdorferi and Anaplasma phagocytophilum in humans and dogs in a New Jersey community

    Directory of Open Access Journals (Sweden)

    Gaito A

    2014-08-01

    Full Text Available Andrea Gaito,1 Vedrana Gjivoje,2 Sebastian Lutz,1 Ben Baxter2 1Private medical practice, Somerset County, NJ, USA; 2Bernardsville Animal Hospital, Somerset County, NJ, USA Abstract: Ticks are important vectors of disease and transmit an extensive array of bacterial, viral and protozoan diseases to both humans and dogs within a community. Borrelia burgdorferi, the causative agent of Lyme disease, has been extensively studied within both the human and veterinary population. Anaplasma phagocytophilum, an intracellular rickettsial pathogen also transmitted by ixodid ticks, has emerged as an important zoonotic infection with significant veterinary and medical implications, and is responsible for both canine granulocytic anaplasmosis and human granulocytic anaplasmosis. Multiple surveys exist in the international literature referencing infectivity rates of both of these diseases separately in both the dog and human populations. This is the first study to simultaneously examine the infectivity rate of both anaplasmosis and Lyme disease in humans and dogs in a community endemic for tick-borne diseases. Keywords: Lyme disease, anaplasmosis, dogs, humans 

  11. ER-Coordinated Activities of Rab22a and Rab5a Drive Phagosomal Compaction and Intracellular Processing of Borrelia burgdorferi by Macrophages

    Directory of Open Access Journals (Sweden)

    Xenia Naj

    2015-09-01

    Full Text Available Borrelia burgdorferi is the causative agent of Lyme disease, a multisystemic disorder affecting the skin, joints, and nervous system. Macrophages and dendritic cells counteract Borrelia dissemination through internalization and degradation of spirochetes. We now show that Borrelia internalization by primary human macrophages involves uptake and compaction into Rab22a-positive phagosomes that are in close contact with Rab5a-positive vesicles. Compaction of borreliae involves membrane extrusion from phagosomes, is driven by Rab22a and Rab5a activity, and is coordinated by ER tubules forming contact sites of Rab22a phagosomes with Rab5a vesicles. Importantly, Rab22a and Rab5a depletion leads to reduced localization to lysosomes and to increased intracellular survival of spirochetes. These data show that Rab22a- and Rab5a-driven phagosomal uptake is a crucial step in the vesicular cascade that leads to elimination of spirochetes by macrophages. Rab22a and Rab5a thus present as potential molecular targets for the modulation of intracellular processing of borreliae in human immune cells.

  12. 一种伯氏疏螺旋体表达质粒的构建%Construction of a shuttle vector for inducible gene expression in Borrelia burgdorferi

    Institute of Scientific and Technical Information of China (English)

    叶美萍; 黄龙丽; 庄振超; 楼永良

    2014-01-01

    Objective To construct a shuttle plasmid for inducible gene expression in Borrelia burgdorferi (B.burgdorferi) with an advantage of flexible genetic manipulation.Methods The IPTG-inducible lac repressor/operator system from Escherichia coli (E.coli) was adopted and modified in the current study.The plasmid shuttle vector was developed by inserting multiple cloning sites,FLAG and HA tags into the shuttle vector by molecular cloning approaches.The target gene was inserted at the site under the control of the promoter (Tn5 derivate) in plasmid pQE30.This promoter contained two lac operators and a codonoptimized lacI gene driven by flaB promoter.Results A plasmid shuttle vector,pJJ275,was successfully constructed with the ability to express target genes in B.burgdorferi in the presence of IPTG.By using this system,a HA-tagged rpoS gene was introduced into the typical infectious strain B.burgdorferi B31.The target gene expression induced by IPTG was confirmed at transcriptional and translational levels.The RpoS dependent virulence factor of Borrelia,OspC,was also detected,indicating that the expressed protein was functional.Conclusion The constructed plasmid shuttle vector can express exogenous genes in B.burgdorferi with an inducible feature and an advantage of flexible genetic manipulation.It can be applied for genetic manipulation of B.burgdorferi involved in gene regulation and complementation.%目的 构建一个具有较强遗传可操作性的大肠杆菌-伯氏疏螺旋体表达穿梭质粒,以期作为工具质粒在疏螺旋体中实现外源基因的可诱导表达.方法 利用源自大肠杆菌的lac表达/诱导系统,在已有的穿梭质粒的基础上,通过分子生物学技术加入多克隆位点和HA、FLAG蛋白表达标签,增加其遗传可操作性.结果 成功构建工具质粒pJ J275,可以用于伯氏疏螺旋体的基因可控制表达.以rpoS基因为例,将其克隆至pJJ275并转入疏螺旋体中,获得的菌株在IPTG存在的条件

  13. Mutations in the Borrelia burgdorferi Flagellar Type III Secretion System Genes fliH and fliI Profoundly Affect Spirochete Flagellar Assembly, Morphology, Motility, Structure, and Cell Division

    Science.gov (United States)

    Gao, Lihui; Zhao, Xiaowei; Liu, Jun; Norris, Steven J.

    2015-01-01

    ABSTRACT The Lyme disease spirochete Borrelia burgdorferi migrates to distant sites in the tick vectors and mammalian hosts through robust motility and chemotaxis activities. FliH and FliI are two cytoplasmic proteins that play important roles in the type III secretion system (T3SS)-mediated export and assembly of flagellar structural proteins. However, detailed analyses of the roles of FliH and FliI in B. burgdorferi have not been reported. In this study, fliH and fliI transposon mutants were utilized to dissect the mechanism of the Borrelia type III secretion system. The fliH and fliI mutants exhibited rod-shaped or string-like morphology, greatly reduced motility, division defects (resulting in elongated organisms with incomplete division points), and noninfectivity in mice by needle inoculation. Mutants in fliH and fliI were incapable of translational motion in 1% methylcellulose or soft agar. Inactivation of either fliH or fliI resulted in the loss of the FliH-FliI complex from otherwise intact flagellar motors, as determined by cryo-electron tomography (cryo-ET). Flagellar assemblies were still present in the mutant cells, albeit in lower numbers than in wild-type cells and with truncated flagella. Genetic complementation of fliH and fliI mutants in trans restored their wild-type morphology, motility, and flagellar motor structure; however, full-length flagella and infectivity were not recovered in these complemented mutants. Based on these results, disruption of either fliH or fliI in B. burgdorferi results in a severe defect in flagellar structure and function and cell division but does not completely block the export and assembly of flagellar hook and filament proteins. PMID:25968649

  14. Serological survey of Bartonella spp., Borrelia burgdorferi, Brucella spp., Coxiella burnetii, Francisella tularensis, Leptospira spp., Echinococcus, Hanta-, TBE- and XMR-virus infection in employees of two forestry enterprises in North Rhine-Westphalia, Germany, 2011-2013.

    Science.gov (United States)

    Jurke, Annette; Bannert, N; Brehm, K; Fingerle, V; Kempf, V A J; Kömpf, D; Lunemann, M; Mayer-Scholl, A; Niedrig, M; Nöckler, K; Scholz, H; Splettstoesser, W; Tappe, D; Fischer, Silke F

    2015-10-01

    We initiated a survey to collect basic data on the frequency and regional distribution of various zoonoses in 722 employees of forestry enterprises in the German state of North Rhine-Westphalia (NRW) from 2011 to 2013. Exposures associated with seropositivity were identified to give insight into the possible risk factors for infection with each pathogen. 41.2% of participants were found to be seropositive for anti-Bartonella IgG, 30.6% for anti-Borrelia burgdorferi IgG, 14.2% for anti-Leptospira IgG, 6.5% for anti-Coxiella burnetii IgG, 6.0% for anti-Hantavirus IgG, 4.0% for anti-Francisella tularensis IgG, 3.4% for anti-TBE-virus IgG, 1.7% for anti-Echinococcus IgG, 0.0% for anti-Brucella IgG and anti-XMRV IgG. Participants seropositive for B. burgdorferi were 3.96 times more likely to be professional forestry workers (univariable analysis: OR 3.96; 95% CI 2.60-6.04; pforestry workers nor office workers represent a risk population and that NRW is not a typical endemic area. Forestry workers appear to have higher risk for contact with B. burgdorferi-infected ticks and a regionally diverse risk for acquiring Hantavirus-infection. The regional epidemiology of zoonoses is without question of great importance for public health. Knowledge of the regional risk factors facilitates the development of efficient prevention strategies and the implementation of such prevention measures in a sustainable manner. PMID:26422407

  15. 莱姆病螺旋体鞭毛平截性蛋白的表达及其诊断潜力研究%Expression on specific fragement of flagellin from Borrelia burgdorferi and its diagnostic

    Institute of Scientific and Technical Information of China (English)

    仝彩玲; 吴银娟; 周勇志; 曹杰; 李培英; 周金林

    2011-01-01

    目的 原核表达伯氏疏螺旋体鞭毛蛋白Flagellin A基因特异性区段,获得重组鞭毛蛋白平截性蛋白作为诊断抗原,建立间接ELISA方法用于动物莱姆病的诊断.方法 PCR扩增获取伯氏疏螺旋体鞭毛蛋白基因的同源性较低的第394-798 bp区段,构建重组质粒pGEX-4T-(1)/tFlaA,构建好的表达质粒转化到大肠杆菌BL21( DE3)中进行表达,并纯化重组蛋白,用纯化的表达蛋白作为莱姆病诊断的抗原,用于ELISA检测实验感染小鼠莱姆病.结果 成功构建莱姆病螺旋体鞭毛平截性蛋白的表达载体,重组蛋白在宿主菌内高效、稳定表达,重组平截性蛋白显示了可作为ELISA诊断的抗原用于莱姆病的诊断价值.结论 纯化的伯氏疏螺旋体鞭毛蛋白可作为莱姆病ELISA诊断抗原用于莱姆病的诊断,为莱姆病快速诊断试剂盒的开发打下基础.%The purpose was to extract Borrelia burgdorferi DNA and use PCR method to obtain the gene coding of the Borrelia burgdorferi flagellin from 394 to 798 nucleotide that exhibited low homology with related gene from other bactdrial specises we insert Borrelia burgdorferi flagellin from 394 to 798 nucleotide to PGEX-4T-1 vector, verified by DNA sequence detection and tren thansformed it into in E. coli BL 21 (DE3) to induce target protein. Then we purified the recombination pro-tein as ELISA antigen to diagnosis Lyme disease. On other hand, we infected mouse with Borrelia burgdorferi. Two weeks, we got positive serum from mouse. We used recombinant protein as diagnostic antigen andpositive mouse serum as antibody to con-duct ELISA test and analysts. The ELISA results showed the feasibility of recombinant protein as diagnostic antigen to diag-nose Lyme disease, which lay foundations for the diagnosis of Lyme disease.

  16. Enhancement of immune response towards non-lipidized Borrelia burgdorferi recombinant OspC antigen by binding onto the surface of metallochelating nanoliposomes with entrapped lipophilic derivatives of norAbuMDP

    Czech Academy of Sciences Publication Activity Database

    Křupka, M.; Mašek, J.; Bartheldyová, E.; Turánek Knotigová, P.; Plocková, J.; Korvasová, Z.; Škrabalová, M.; Koudelka, Š.; Kulich, P.; Zachová, K.; Czerneková, L.; Strouhal, O.; Horynová, M.; Šebela, M.; Miller, A. D.; Ledvina, Miroslav; Raška, M.; Turánek, J.

    2012-01-01

    Roč. 160, č. 2 (2012), s. 374-381. ISSN 0168-3659 R&D Projects: GA ČR(CZ) GAP304/10/1951; GA TA ČR TA01011165; GA AV ČR(CZ) KAN200520703; GA AV ČR KAN200100801 Grant ostatní: GA UP(CZ) LF-2010-014; GA UP(CZ) LF-2011-002 Institutional research plan: CEZ:AV0Z40550506 Keywords : Borrelia burgdorferi * OspC * metallochelating liposomes * MDP Subject RIV: CC - Organic Chemistry Impact factor: 7.633, year: 2012

  17. Abrogation of ospAB constitutively activates the Rrp2-RpoN-RpoS pathway (sigmaN-sigmaS cascade) in Borrelia burgdorferi.

    Science.gov (United States)

    He, Ming; Oman, Tara; Xu, Haijun; Blevins, Jon; Norgard, Michael V; Yang, X Frank

    2008-12-01

    Molecular mechanisms underlying the reciprocal regulation of the two major surface lipoproteins and virulence factors of Borrelia burgdorferi, OspA and OspC, are not fully understood. Herein, we report that inactivation of the ospAB operon resulted in overproduction of OspC and many other lipoproteins via the constitutive activation of the Rrp2-RpoN-RpoS pathway. Complementing the ospAB mutant with a wild-type copy of ospA, but not an ospA variant that lacks the lipoprotein signal sequence, restored normal regulation of the Rrp2-RpoN-RpoS pathway; these results indicate that the phenotype was not caused by spurious mutations. Interestingly, while most of the ospAB mutant clones displayed a constitutive ospC expression phenotype, some ospAB mutant clones showed little or no ospC expression. Further analyses revealed that this OspC-negative phenotype was independent of abrogation of ospAB. While activation of the Rrp2-RpoN-RpoS pathway was recently shown to downregulate ospA, our findings suggest that reduction of OspA can also activate this pathway. We postulate that the activation of the Rrp2-RpoN-RpoS pathway and downregulation of OspA form a positive feedback loop that allows spirochaetes to produce and maintain a constant high level of OspC and other lipoproteins during tick feeding, a strategy that is critical for spirochaetal transmission and mammalian infection. PMID:19019147

  18. The crystal structures of two salivary cystatins from the tick Ixodes scapularis and the effect of these inhibitors on the establishment of Borrelia burgdorferi infection in a murine model

    Energy Technology Data Exchange (ETDEWEB)

    Kotsyfakis, Michalis; Horka, Helena; Salat, Jiri; Andersen, John F. (South Bohemia); (ASCR-ICP); (NIAID)

    2010-11-17

    We have previously demonstrated that two salivary cysteine protease inhibitors from the Borrelia burgdorferi (Lyme disease) vector Ixodes scapularis - namely sialostatins L and L2 - play an important role in tick biology, as demonstrated by the fact that silencing of both sialostatins in tandem results in severe feeding defects. Here we show that sialostatin L2 - but not sialostatin L - facilitates the growth of B. burgdorferi in murine skin. To examine the structural basis underlying these differential effects of the two sialostatins, we have determined the crystal structures of both sialostatin L and L2. This is the first structural analysis of cystatins from an invertebrate source. Sialostatin L2 crystallizes as a monomer with an 'unusual' conformation of the N-terminus, while sialostatin L crystallizes as a domain-swapped dimer with an N-terminal conformation similar to other cystatins. Deletion of the 'unusual' N-terminal five residues of sialostatin L2 results in marked changes in its selectivity, suggesting that this region is a particularly important determinant of the biochemical activity of sialostatin L2. Collectively, our results reveal the structure of two tick salivary components that facilitate vector blood feeding and that one of them also supports pathogen transmission to the vertebrate host.

  19. Generational diversity.

    Science.gov (United States)

    Kramer, Linda W

    2010-01-01

    Generational diversity has proven challenges for nurse leaders, and generational values may influence ideas about work and career planning. This article discusses generational gaps, influencing factors and support, and the various generational groups present in today's workplace as well as the consequences of need addressing these issues. The article ends with a discussion of possible solutions. PMID:20395729

  20. Exposure to ticks and seroprevalence of [i]Borrelia burgdorferi [/i]among a healthy young population living in the area of southern Podlasie, Poland

    Directory of Open Access Journals (Sweden)

    Anna Pańczuk

    2014-09-01

    Full Text Available [b]Objectives[/b]. The objective of the study was assessment of risk of infection with [i]Borrelia burgdorferi[/i] in the area of southern Podlasie in Poland, near the border with Belarus, by analysis of post-exposure procedure, and evaluation of asymptomatic infection in adolescents bitten by a tick, confirmed by serologic tests. [b]Material and methods[/b]. The study was conducted among 128 healthy individuals aged 16–20 who declared being bitten by a tick. The level of IgM and IgG class antibodies was determined using the immunoenzymatic test (Borrelia 14 kD + OspC IgM ELISA and Borrelia IgG + VlsE ELISA, DRG Diagnostics. Positive and doubtful results were confirmed using the Western blot method (EUROLINE-WB, EUROIMMUN. [b]Results[/b]. In the study group, the largest number of respondents (59.4% declared tick bite in the region of the lower extremities, most often in the knee pit. Among the methods for removing the tick the largest number of respondents indicated removing it with the use of tweezers, with a simple, swift steady movement (29.7%, and pulling it out with the fingers (22.7%. In the ELISA test, a positive or doubtful result in at least one class was observed in 25.0% of respondents (n=32/128: in IgM class – 23.4% (n=30/128, and in IgG class – 4.7% (n=6/128. After verification with the Western blot test, infection was confirmed in 5.5% of respondents (n=7/128: in IgM class – 1.6% (n=2/128, in IgG class – 3.9% (n=5/128. In IgM class antibodies, the Western blot test confirmed positive or doubtful results of the ELISA test in 6.7%, while in IgG class antibodies in 83.3%. [b]Conclusion[/b]. Evaluation of the actual infection with [i]Borrelia spp.[/i] using serologic tests is difficult due to a certain non-specificity of the ELISA test, especially in IgM class antibodies, and difficulties with performance of a wide scope of specific Western blot tests. The variety of methods of tick removal declared by adolescents suggests

  1. Prevalence of Dirofilaria immitis, Ehrlichia canis, Borrelia burgdorferi sensu lato, Anaplasma spp. and Leishmania infantum in apparently healthy and CVBD-suspect dogs in Portugal - a national serological study

    Directory of Open Access Journals (Sweden)

    Cardoso Luís

    2012-03-01

    Full Text Available Abstract Background Canine vector-borne diseases (CVBDs are caused by a wide range of pathogens transmitted to dogs by arthropods including ticks and insects. Many CVBD-agents are of zoonotic concern, with dogs potentially serving as reservoirs and sentinels for human infections. The present study aimed at assessing the seroprevalence of infection with or exposure to Dirofilaria immitis, Ehrlichia canis, Borrelia burgdorferi sensu lato, Anaplasma spp. and Leishmania infantum in dogs in Portugal. Methods Based on 120 veterinary medical centres from all the regions of mainland and insular Portugal, 557 apparently healthy and 628 CVBD-suspect dogs were sampled. Serum, plasma or whole blood was tested for qualitative detection of D. immitis antigen and antibodies to E. canis, B. burgdorferi s. l., Anaplasma spp. and L. infantum with two commercial in-clinic enzyme-linked immunosorbent assay kits. Odds ratios (OR were calculated by logistic regression analysis to identify independent risk factors of exposure to the vector-borne agents. Results Total positivity levels to D. immitis, E. canis, B. burgdorferi, Anaplasma spp., L. infantum, one or more agents and mixed agents were 3.6%, 4.1%, 0.2%, 4.5%, 4.3%, 14.0% and 2.0% in the healthy group, and 8.9%, 16.4%, 0.5%, 9.2%, 25.2%, 46.3% and 11.6% in the clinically suspect group, respectively. Non-use of ectoparasiticides was a risk factor for positivity to one or more agents both in the apparently healthy (OR = 2.1 and CVBD-suspect (OR = 1.5 dogs. Seropositivity to L. infantum (OR = 7.6, E. canis (OR = 4.1 and D. immitis (OR = 2.4 were identified as risk factors for the presence of clinical signs compatible with CVBDs. Positivity to mixed agents was not found to be a risk factor for disease. Conclusions Dogs in Portugal are at risk of becoming infected with vector-borne pathogens, some of which are of zoonotic concern. CVBDs should be considered by practitioners and prophylactic measures must be put in

  2. The ospA genes of Borrelia burgdorferi sensu lato detected in rodents in Zhejiang province%浙江省在鼠类中检测到伯氏疏螺旋体ospA基因

    Institute of Scientific and Technical Information of China (English)

    姜理平; 陆群英; 李钟梁; 张磊; 王复甦; 张政

    2012-01-01

    目的 了解浙江省磐安县鼠中感染伯氏疏螺旋体的情况,研究以外膜蛋白A(OspA)为靶基因的PCR方法在浙江省的应用.方法 利用PCR方法,检测磐安县128份鼠肝、脾标本中ospA基因特异片段;对所检测到的阳性结果进行序列测定,并进行分析.结果 从128份鼠肝、脾标本中检测发现4例ospA基因阳性片段,其中3份来自黄毛鼠,1份来自大林姬鼠;核酸序列基本一致,与伯氏疏螺旋体法雷斯疏螺旋体高度相似.结论 利用ospA基因能从标本中检测到伯氏疏螺旋体;浙江省部分山区存在鼠感染伯氏疏螺旋体的情况,其中伯氏疏螺旋体法雷斯疏螺旋体占优势.%Objective To identify Borrelia burgdorferi sensu lato infection of rodents in Pan' an county, Zhejiang province. Methods The ospA gene specific fragments from 128 mouse liver and spleen samples were detected using the PCR method and the positive samples were sequenced, followed by phylogenetic analysis. Results It was found that there were four ospA gene positive fragments out of the 128 samples, of which 3 fragments were obtained from Rattus losea and the other one was from Apodemus peninsulae. The 4 positive fragments shared high similarity with each other in terms of the sequences and shared high identities with B. Valaisiana. Conclusion B. Burgdorferi sensu lato can be detected from samples using the ospA gene. There exists B. Burgdorferi sensu lato infection in rodents in some mountain areas of Zhejiang province, and B. Valaisiana is found to be predominant.

  3. 青海省互助、泽库和祁连县啮齿类动物伯氏疏螺旋体调查%Investigation of Borrelia burgdorferi in Glires in Huzhu, Zekog, and Qilian county, Qinghai

    Institute of Scientific and Technical Information of China (English)

    张琳; 石燕; 耿震; 侯学霞; 郝琴

    2015-01-01

    目的:调查确定青海省3县啮齿类标本中伯氏疏螺旋体带菌情况。方法从青海省互助、泽库和祁连县共采集啮齿类动物202只,采用巢式PCR方法检测其伯氏疏螺旋体的带菌率。结果采用巢式PCR方法检测啮齿类动物标本202份,阳性49份,伯氏疏螺旋体平均阳性率为24.26%。其中互助县标本共67份,阳性12份,阳性率为17.91%;泽库县标本共78份,阳性27份,阳性率为34.62%;祁连县标本共57只,阳性10份,阳性率为17.54%。3个县的啮齿类动物伯氏疏螺旋体阳性率差异有统计学意义(χ2=7.40,P<0.05)。结论青海省互助、泽库和祁连县啮齿类动物中均存在伯氏疏螺旋体感染,应进一步对当地的媒介和人群进行调查,从而为当地莱姆病的防控提供参考。%Objective To identify the Borrelia burgdorferi in Glires in Huzhu, Zekog, and Qilian county, Qinghai province. Methods A total of 202 Glires were collected from forest in the counties, Qinghai province. All the collected samples were examined for B. burgdorferi by nested PCR. Results In total of 202 samples, 49 samples were tested positive by 24.26%. Positive rate was 17.91%(12/67) in Huzhu county, 34.62%(27/78) in Zekog county and 17.54%(10/57) in Qilian county. There was significant difference with positive rate of B. burgdorferi in Glires among these three counties(χ2=7.40, P<0.05). Conclusion Our research confirmed the existence of B. burgdorferi in Glires in three counties in Qinghai province. We suggested that the further investigation on local vectors and human infections be conducted for prevention and control of Lyme disease.

  4. Radioisotope generator

    International Nuclear Information System (INIS)

    A radioisotope generator is described in which it is possible to interupt the elution process at any desired time, i.e. before the electron flacon is full. The interuption is performed in such a way that sterile air is simultaneously admitted into the generator, into both the column and the elution flacon. (Th.P.)

  5. Generative collectives

    NARCIS (Netherlands)

    W. van Osch; M. Avital

    2010-01-01

    Analyzing generative group activities against the backdrop of an increasingly connected world, this theory development paper introduces the concept of "generative collectives" as a new framework for classifying internet-based collectives and a novel theoretical lens for explaining why some internet-

  6. Recombinant constructs of Borrelia burgdorferi

    Energy Technology Data Exchange (ETDEWEB)

    Dattwyler, Raymond J. (Setauket, NY); Gomes-Solecki, Maria J. C. (New York, NY); Luft, Benjamin J. (East Setauket, NY); Dunn, John J.(Bellport, NY)

    2007-02-20

    Novel chimeric nucleic acids, encoding chimeric Borrelia proteins comprising OspC or an antigenic fragment thereof and OspA or an antigenic fragment thereof, are disclosed. Chimeric proteins encoded by the nucleic acid sequences are also disclosed. The chimeric proteins are useful as vaccine immunogens against Lyme borreliosis, as well as for immunodiagnostic reagents.

  7. 莱姆病螺旋体感染对蜱的4个功能基因的转录影响%Effects of Borrelia burgdorferi infection on the transcription of four functional genes in the tick

    Institute of Scientific and Technical Information of China (English)

    吴银娟; 李国清; 仝彩玲; 曹杰; 周勇志; 周金林

    2011-01-01

    To explore the new strategy for preventing and controlling the tick and vector-bome disease, and to understand the molecular mechanism of interaction between pathogen and vector ticks, we studied the effect on the transcription of the four functional genes of tick after Borrelia burgdorfen infection. Total RNA was isolated at different time points from Haemaphysalis longicomis microinjected with B. burgdorferi suspension at different concentrations. After reverse transcription into cDNA, quantitative real-time fluorescence PCR was used to analyze the expression level of the four functional genes. The resulta showed that it had a significant effect on the transcription of the functional genes encoding cystatin, folliatatin-related protein and hemalin of the ticks by B. burgdorferi infection, despite the existence of dose-and time-dependent manners. On the fourth day, the expression of HLcyst-1 gene dramatically induced, but the expression of hemalin gene was inhibited.%为探索蜱及蜱传病的防控新策略,了解病原与媒介硬蜱相互作用的分子机制,本研究以莱姆病病原伯氏疏螺旋体感染后对长角血蜱4个功能基因的转录影响进行了研究.将不同浓度梯度的伯氏疏螺旋体显微注射到长角血蜱体内,分不同的时间段提取蜱的总RNA,反转录成cDNA后,用实时荧光定量PCR检测蜱基因的表达水平.结果显示:伯氏疏螺旋体感染对蜱半胱氨酸蛋白酶抑制剂1(HLcyst-1)、半胱氨酸蛋白酶抑制剂3(HLcyst-3)、卵泡抑素(FRP)、凝血酶抑制剂(Hemalin)4个功能基因的转录均产生了显著影响,但存在时间和剂量相关性,感染后第4天显著诱导了长角血蜱HLcyst-1基因的表达,抑制了Hemalin基因表达.

  8. Use of the "blue halo" assay in the identification of genes encoding exported proteins with cleavable signal peptides: cloning of a Borrelia burgdorferi plasmid gene with a signal peptide.

    Science.gov (United States)

    Giladi, M; Champion, C I; Haake, D A; Blanco, D R; Miller, J F; Miller, J N; Lovett, M A

    1993-07-01

    We have recently reported a phoA expression vector, termed pMG, which, like TnphoA, is useful in identifying genes encoding membrane-spanning sequences or signal peptides. This cloning system has been modified to facilitate the distinction of outer membrane and periplasmic alkaline phosphatase (AP) fusion proteins from inner membrane AP fusion proteins by transforming pMG recombinants into Escherichia coli KS330, the strain utilized in the "blue halo" assay first described by Strauch and Beckwith (Proc. Natl. Acad. Sci. USA 85:1576-1580, 1988). The lipoprotein mutation lpp-5508 of KS330 results in an outer membrane that is leaky to macromolecules, and its degP4 mutation greatly reduces periplasmic proteolytic degradation of AP fusion proteins. pMG AP fusions containing cleavable signal peptides, including the E. coli periplasmic protein beta-lactamase, the E. coli and Chlamydia trachomatis outer membrane proteins OmpA and MOMP, respectively, and Tp 9, a Treponema pallidum AP recombinant, diffused through the leaky outer membrane of KS330 and resulted in blue colonies with blue halos. In contrast, inner membrane AP fusions derived from E. coli proteins, including leader peptidase, SecY, and the tetracycline resistance gene product, as well as Tp 70, a T. pallidum AP recombinant which does not contain a signal peptide, resulted in blue colonies without blue halos. Lipoprotein-AP fusions, including the Borrelia burgdorferi OspA and T. pallidum Tp 75 and TmpA showed halo formation, although there was significantly less halo formation than that produced by either periplasmic or outer membrane AP fusions. In addition, we applied this approach to screen recombinants constructed from a 9.0-kb plasmid isolated from the B31 virulent strain of B. burgdorferi. One of the blue halo colonies identified produced an AP fusion protein which contained a signal peptide with a leader peptidase I cleavage recognition site. The pMG/KS330r- cloning and screening approach can identify

  9. Cluster generator

    Science.gov (United States)

    Donchev, Todor I.; Petrov, Ivan G.

    2011-05-31

    Described herein is an apparatus and a method for producing atom clusters based on a gas discharge within a hollow cathode. The hollow cathode includes one or more walls. The one or more walls define a sputtering chamber within the hollow cathode and include a material to be sputtered. A hollow anode is positioned at an end of the sputtering chamber, and atom clusters are formed when a gas discharge is generated between the hollow anode and the hollow cathode.

  10. Magnet Free Generators - 3rd Generation Wind Turbine Generators

    DEFF Research Database (Denmark)

    Jensen, Bogi Bech; Mijatovic, Nenad; Henriksen, Matthew Lee

    2013-01-01

    This paper presents an introduction to superconducting wind turbine generators, which are often referred to as 3rd generation wind turbine generators. Advantages and challenges of superconducting generators are presented with particular focus on possible weight and efficiency improvements. A...

  11. Embedded generation

    CERN Document Server

    Jenkins, Nick; Crossley, Peter

    2000-01-01

    The use of combined heat and power (CHP) plants and renewable energy sources reduces the amount of greenhouse gases released into the atmosphere and helps to alleviate the consequent climate change. The policies of many governments suggest that the proportion of electrical energy produced by these sources will increase dramatically over the next two decades. Unlike traditional generating units, these new types of power plant are usually 'embedded' in the distribution system or 'dispersed' around the network. As a result, conventional design and operating practices are no longer applicable; for

  12. Power generation

    International Nuclear Information System (INIS)

    In the second half of twentieth century, nuclear power became an industrial reality. Now the operating 433 power plants, the 37 plants under construction, near 9000 years/reactor with only one serious accident with emission of radioactive material to the environment (Chernobyl) show the maturity of this technology. Today nuclear power contribute a 17% to the global generation and an increase of 75 % of the demand of electricity is estimated for 2020 while this demand is expected to triplicate by 2050. How this requirement can be satisfied? All the indicators seems to demonstrate that nuclear power will be the solution because of the shortage of other sources, the increase of the prices of the non renewable fuels and the scarce contribution of the renewable ones. In addition, the climatic changes produced by the greenhouse effect make even more attractive nuclear power. The situation of Argentina is analyzed and compared with other countries. The convenience of an increase of nuclear power contribution to the total national generation seems clear and the conclusion of the construction of the Atucha II nuclear power plant is recommended

  13. A serological survey of tick-borne pathogens in dogs in North America and the Caribbean as assessed by Anaplasma phagocytophilum, A. platys, Ehrlichia canis, E. chaffeensis, E. ewingii, and Borrelia burgdorferi species-specific peptides

    Directory of Open Access Journals (Sweden)

    Barbara A. Qurollo

    2014-10-01

    Full Text Available Introduction: Tick-borne pathogens cause a spectrum of disease manifestations in both dogs and humans. Recognizing regional and temporal shifts in exposure are important as tick distributions change. To better delineate regional exposure to canine tick-borne pathogens, an expanded set of species-specific peptides were used to detect Anaplasma phagocytophilum (Aph, Anaplasma platys (Apl, Ehrlichia canis (Ec, Ehrlichia chaffeensis (Ech, Ehrlichia ewingii (Eew, and Borrelia burgdorferi (Bb antibodies in canine serum. Methods: Archived canine serum samples (n=6,582 collected during 2008–2010 and in 2012 from the US, Canada, and the Caribbean were retrospectively screened for antibodies against Ehrlichia and Anaplasma species-specific peptides. Overall, regional and temporal seroprevalence rates were determined. Results: Overall Bb and Eew were the most seroprevalent pathogens. During 2008–2010, seroprevalence rates increased overall for Aph and Ech, and regionally, Bb and Aph seroprevalence rates increased in the South. Canada had unexpectedly high seroprevalence rates for Ec and Apl. The most common co-exposures were Eew+Ech, followed by Aph+Bb and Eew+Bb. Conclusions: This study demonstrated significant shifts in canine vector-borne disease seroprevalence rates. The use of specific peptides facilitated improved geographic delineation of tick-borne pathogen distributions among dogs, which may enhance epidemiological surveillance of vector-borne pathogens shared by dogs and humans.

  14. A Genotype Loop-mediated Isothermal Amplification (LAMP) for Borrelia Burgdorferi of Lyme Disease%环介导恒温扩增对莱姆病病原伯氏疏螺旋体的分型鉴定

    Institute of Scientific and Technical Information of China (English)

    杨吉飞; 杨朝霞; 罗建勋; 殷宏; 关贵全; 牛庆丽; 李有全; 刘军龙; 马米玲; 任巧云; 刘爱红; 王子坚

    2010-01-01

    使用环介导恒温扩增技术,基于莱姆病病原伯氏疏螺旋体的外膜蛋白A (OspA)基因,针对伯氏疏螺旋体不同的基因型设计特异性引物,对国内主要的莱姆病病原伯氏疏螺旋体的3个基因型进行分型鉴定.研究结果表明,设计的引物具有良好的特异性,可以对狭义伯氏疏螺旋体(Borrelia burgdorferi sensu strict)、嘎氏疏螺旋体(B.afzelii)和伽氏疏螺旋体(B.garinii)进行分型鉴定.伯氏疏螺旋体的分型鉴定可以对不同临床症状莱姆病患者的治疗和莱姆病的控制提供一定的依据.

  15. Isolation and identification of Borrelia burgdorferi sensu lato from ticks in six provinces in China%中国六省蜱中莱姆病螺旋体分离与鉴定

    Institute of Scientific and Technical Information of China (English)

    耿震; 侯学霞; 万康林; 郝琴

    2010-01-01

    目的 了解中国6省蜱中莱姆病螺旋体携带情况.方法 在6省各选取2个采样点捕蜱,采用病原分离培养和巢式PCR方法对蜱进行莱姆病螺旋体检测,通过基因测序确定分型.结果 6省共采集到2200余只蜱,约1000只蜱用于病原分离培养,从吉林省长白县全沟硬蜱标本中分离到13株螺旋体,从贵州省道真粒形硬蜱标本中分离到9株螺旋体.1255只蜱用于PCR检测,从6省的蜱标本中检测到莱姆病螺旋体特异片段,其中吉林省(长白县27.08%、通化县20.41%)、青海省(互助县25.06%、黄南县21.11%)和贵州省(道真县25.63%)蜱中莱姆病螺旋体阳性率较高,山西省(垣曲县4.72%、交城县3.64%)蜱中莱姆病螺旋体阳性率较低.通过序列同源性分析确定吉林、青海、甘肃和山西省蜱中莱姆病螺旋体基因型均为Borrelia garinii.贵州、湖南省的基因型均为Borrelia valaisiana.结论 6省蜱中均带有莱姆病螺旋体,且带菌率有差异;山西省蜱中存在Borrelia ganmi型莱姆病螺旋体,湖南省蜱中存在Borrelia valaisiana型莱姆病螺旋体.%Objective To understand the carrying status of Borrelia burgdorferi in ticks from the mountain areas from six representative provinces, including Jilin, Shanxi, Gansu, Qinghai,Guizhou and Hunan in China. Methods Flagging and trapping methods were used to collect ticks in forest area and culture medium was used to isolate the pathogen. Nested-PCR was used to detect the gem-carrying rate of ticks. Results More than 2200 ticks from six representative provinces were collected and 1000 ticks were used to isolate the pathogen. 13 Lyme disease spirochetes from ixodes persulcatus in Changbai, Jilin province and 9 Lyme disease spirochetes from ixodes granulatus in Daozhen, Guizhou province were identified. There were 1255 ticks used for PCR testing. Specific fragments of the Borrelia burgdorferi in ticks were found from the six representative provinces in China. The carrier

  16. 伯氏疏螺旋体分子生物学分型进展及其意义%Advance in molecular biologic typing of Borrelia burgdorferi and its significance

    Institute of Scientific and Technical Information of China (English)

    李建民; 曹务春

    2002-01-01

    @@ 姆病是一种蜱传全球性动物源性疾病,病原体由W.Burgdorfer首次分离并被命名为伯氏疏螺旋体.根据DNA和蛋白质分析,伯氏疏螺旋体可以分为10个基因型或基因群,即B.burgdorferi sensu stricto(B31T,标准株为B31;B.为Borrelia.的简写)、B.afzelii(VS461)、B.garinii(20047)、B.japonica(HO14)、B.andersonii(21123)、B.lusitaiae(PotiB2)、B.valaisiana(vs116)、B.tanukii(HK501)、B.turdae(Ya501)和基因群DN127[1~7].分子生物学分型包括表型分型和基因分型,评价不同分子生物学分型方法主要依据可分型性、可重复性、分辨率、易操作性、及结果易解释性.分子生物学分型方法较多,包括G+C mol%、DNA-DNA杂交、核糖体分型、PCR-RFLP、染色体DNA脉冲电泳、蛋白质电泳和多位点酶电泳、PCR-杂交、基因型特异性PCR及核酸序列聚类分析技术等.

  17. Generational Dynamics and Librarianship: Managing Generation X.

    Science.gov (United States)

    Cooper, Julie F.; Cooper, Eric A.

    1998-01-01

    Explores the abilities of Generation X (individuals born 1961 to 1981) librarians to respond to the evolving needs of society. Highlights include age demographics, generational attributes, technology, and the seniority system. (PEN)

  18. Distributed generation induction and permanent magnet generators

    CERN Document Server

    Lai, L

    2007-01-01

    Distributed power generation is a technology that could help to enable efficient, renewable energy production both in the developed and developing world. It includes all use of small electric power generators, whether located on the utility system, at the site of a utility customer, or at an isolated site not connected to the power grid. Induction generators (IGs) are the cheapest and most commonly used technology, compatible with renewable energy resources. Permanent magnet (PM) generators have traditionally been avoided due to high fabrication costs; however, compared with IGs they are more reliable and productive. Distributed Generation thoroughly examines the principles, possibilities and limitations of creating energy with both IGs and PM generators. It takes an electrical engineering approach in the analysis and testing of these generators, and includes diagrams and extensive case study examples o better demonstrate how the integration of energy sources can be accomplished. The book also provides the ...

  19. Talkin' 'bout My Generation

    Science.gov (United States)

    Rickes, Persis C.

    2010-01-01

    The monikers are many: (1) "Generation Y"; (2) "Echo Boomers"; (3) "GenMe"; (4) the "Net Generation"; (5) "RenGen"; and (6) "Generation Next". One name that appears to be gaining currency is "Millennials," perhaps as a way to better differentiate the current generation from its predecessor, Generation X. Millennials are those individuals born…

  20. MHD Power Generation

    Science.gov (United States)

    Kantrowitz, Arthur; Rosa, Richard J.

    1975-01-01

    Explains the operation of the Magnetohydrodynamic (MHD) generator and advantages of the system over coal, oil or nuclear powered generators. Details the development of MHD generators in the United States and Soviet Union. (CP)

  1. Inductive Pulse Generation

    OpenAIRE

    Lindblom, Adam

    2006-01-01

    Pulsed power generators are a key component in compact systems for generation of high-power microwaves (HPM). HPM generation by virtual cathode devices such as Vircators put high demands on the source. The rise time and the pulse length of the source voltage are two key issues in the generation of HPM radiation. This thesis describes the construction and tests of several inductive high power pulse generators. The pulse generators were designed with the intent to deliver a pulse with fast rise...

  2. Power Generation for River and Tidal Generators

    Energy Technology Data Exchange (ETDEWEB)

    Muljadi, Eduard [National Renewable Energy Lab. (NREL), Golden, CO (United States); Wright, Alan [National Renewable Energy Lab. (NREL), Golden, CO (United States); Gevorgian, Vahan [National Renewable Energy Lab. (NREL), Golden, CO (United States); Donegan, James [Ocean Renewable Power Company (ORPC), Portland, ME (United States); Marnagh, Cian [Ocean Renewable Power Company (ORPC), Portland, ME (United States); McEntee, Jarlath [Ocean Renewable Power Company (ORPC), Portland, ME (United States)

    2016-06-01

    Renewable energy sources are the second largest contributor to global electricity production, after fossil fuels. The integration of renewable energy continued to grow in 2014 against a backdrop of increasing global energy consumption and a dramatic decline in oil prices during the second half of the year. As renewable generation has become less expensive during recent decades, and it becomes more accepted by the global population, the focus on renewable generation has expanded from primarily wind and solar to include new types with promising future applications, such as hydropower generation, including river and tidal generation. Today, hydropower is considered one of the most important renewable energy sources. In river and tidal generation, the input resource flow is slower but also steadier than it is in wind or solar generation, yet the level of water turbulent flow may vary from one place to another. This report focuses on hydrokinetic power conversion.

  3. 莱姆病螺旋体重组质粒pBX1的DNA序列分析及其在大肠杆菌中的诱导表达%DNA Sequence Analysis and Expression of the Recombinant Plasmid pBX1 from Borrelia Burgdorferi B31 Strain

    Institute of Scientific and Technical Information of China (English)

    谢勇恩; 鲍朗; 胡昌华; 李学敏; 陈炜

    2001-01-01

    目的为莱姆病血清学诊断和基因工程亚单位疫苗研制提供靶抗原。方法采用377型DNA自动测序仪对莱姆病螺旋体重组质粒pBX1的插入片段进行DNA序列测定,并通过计算机软件对其进行限制性内切酶酶谱分析。然后将重组质粒pBX1在大肠杆菌中进行诱导表达,并对其表达产物进行免疫印迹分析。结果①重组质粒pBX1插入片段大小为477bp,其核苷酸序列与文献报道的p83基因全序列相应区段相比较仅有一个碱基的变异,②成功绘制了该插入片段的限制性内切酶酶谱;③重组质粒在大肠杆菌中诱导表达后获得了29kd的融合蛋白;④Western-blotting分析表明该融合蛋白能与莱姆病多价抗血清呈强阳性印迹反应。结论该研究成功地对莱姆病螺旋体83kd抗原蛋白特异性区段进行了基因重组和表达,为进一步研究其在莱姆病血清学诊断和基因工程亚单位疫苗研制中的应用奠定了基础。%Objective This study was to provide the target antigen for the development of a Lyme disease vaccine and serodiagnosis reagent.Methods We used the automatic DNA sequencing machine (Model 377) to detect the nucleotide sequence of the inserted part of the recombinant plasmid pBX1 from Borrelia burgdorferi B31 strain. The restriction enzyme map of the inserted part of pBX1 was analysed by using computer software. The expressed product of pBX1 in E.coli XLI-Blue MRF′ was analysed by using SDS-PAGE and western-blotting. Results ①DNA sequencing showed that pBX1 contained a 477bp inserted gene fragment,and when it was compared with the published sequence of the specific region of the gene of the 83kd antigen protein from Borrelia burgdorferi B31 strain,only one amino acid codon was different.②The restriction enzyme map of the inserted part of pBX1 was successfully constructed.③The recombinant plasmid pBX1 expressed a 29kd fusion protein in E.coli XL1-Blue MRF

  4. Magnetohydrodynamic (MHD) power generation

    International Nuclear Information System (INIS)

    The concept of MHD power generation, principles of operation of the MHD generator, its design, types, MHD generator cycles, technological problems to be overcome, the current state of the art in USA and USSR are described. Progress of India's experimental 5 Mw water-gas fired open cycle MHD power generator project is reported in brief. (M.G.B.)

  5. Work Values across Generations

    Science.gov (United States)

    Hansen, Jo-Ida C.; Leuty, Melanie E.

    2012-01-01

    Mainstream publication discussions of differences in generational cohorts in the workplace suggest that individuals of more recent generations, such as Generation X and Y, have different work values than do individuals of the Silent and Baby Boom generations. Although extant research suggests that age may influence work values, few of the…

  6. Frequency of antibodies to Babesia bigemina, B. bovis, Anaplasma marginale, Trypanosoma vivax and Borrelia burdgorferi in cattle from the northeastern region of the state of Pará, Brazil Freqüência de anticorpos para Babesia bigemina, B. bovis, Anaplasma marginale, Trypanosoma vivax e Borrelia burgdorferi em bovinos do nordeste do Estado do Pará, Brasil

    Directory of Open Access Journals (Sweden)

    Daniel S. Guedes Junior

    2008-06-01

    Full Text Available Babesiosis, anaplasmosis, and trypanosomosis are relevant diseases, potentially causing morbidity in cattle, leading to economic losses. Borreliosis is import as a potential zoonosis. The objective of this study was to determine, by indirect enzyme-linked immunosorbent assay (ELISA, the frequency of seropositive cattle to Babesia bigemina, B. bovis, Anaplasma marginale, Trypanosoma vivax and Borrelia burgdorferi in cattle from the Northeastern region of Pará, Brazil. Sera samples from 246 female adult cattle from municipalities of Castanhal and São Miguel do Guamá were used. Crude antigens ELISAs were used to detect antibodies to all agents, except to A. marginale, to which an indirect ELISA with recombinant major surface 1a protein (MSP1a antigen was used. Overall frequencies of seropositive animals were: B. bigemina - 99.2%; B. bovis - 98.8%; A. marginale - 68.3%; T. vivax - 93.1% and B. burgdorferi - 54.9%. The frequencies of seropositive cattle to B. bovis and B. bigemina suggest a high rate of transmission of these organisms by tick in the studied region, which can be classified as enzootically stable to these hemoprotozoans. The low frequency of seropositive cattle to A. marginale may be attributed to a lower sensitivity of the recombinant antigen ELISA utilized or a distinct rate of inoculation of this rickettsia by ticks, as compared with Babesia sp. transmission. The high frequency of seropositive cattle to T. vivax indicates that this hemoprotozoan is prevalent in herds from the Northeastern region of Pará. The rate of animal that showed homologues antibodies to B. burgdorferi indicates the presence of the tickborne spirochaetal agent in the cattle population in the studied region.A babesiose, a anaplasmose e a tripanossomose são enfermidades relevantes, potencialmente causadoras de morbidade em bovinos, levando a perdas econômicas. A borreliose assume importância como zoonose potencial. O objetivo desse estudo foi determinar

  7. Cylindrical neutron generator

    Science.gov (United States)

    Leung, Ka-Ngo

    2008-04-22

    A cylindrical neutron generator is formed with a coaxial RF-driven plasma ion source and target. A deuterium (or deuterium and tritium) plasma is produced by RF excitation in a cylindrical plasma ion generator using an RF antenna. A cylindrical neutron generating target is coaxial with the ion generator, separated by plasma and extraction electrodes which contain many slots. The plasma generator emanates ions radially over 360.degree. and the cylindrical target is thus irradiated by ions over its entire circumference. The plasma generator and target may be as long as desired. The plasma generator may be in the center and the neutron target on the outside, or the plasma generator may be on the outside and the target on the inside. In a nested configuration, several concentric targets and plasma generating regions are nested to increase the neutron flux.

  8. Refrigeration generation using expander-generator units

    Science.gov (United States)

    Klimenko, A. V.; Agababov, V. S.; Koryagin, A. V.; Baidakova, Yu. O.

    2016-05-01

    The problems of using the expander-generator unit (EGU) to generate refrigeration, along with electricity were considered. It is shown that, on the level of the temperatures of refrigeration flows using the EGU, one can provide the refrigeration supply of the different consumers: ventilation and air conditioning plants and industrial refrigerators and freezers. The analysis of influence of process parameters on the cooling power of the EGU, which depends on the parameters of the gas expansion process in the expander and temperatures of cooled environment, was carried out. The schematic diagram of refrigeration generation plant based on EGU is presented. The features and advantages of EGU to generate refrigeration compared with thermotransformer of steam compressive and absorption types were shown, namely: there is no need to use the energy generated by burning fuel to operate the EGU; beneficial use of the heat delivered to gas from the flow being cooled in equipment operating on gas; energy production along with refrigeration generation, which makes it possible to create, using EGU, the trigeneration plants without using the energy power equipment. It is shown that the level of the temperatures of refrigeration flows, which can be obtained by using the EGU on existing technological decompression stations of the transported gas, allows providing the refrigeration supply of various consumers. The information that the refrigeration capacity of an expander-generator unit not only depends on the parameters of the process of expansion of gas flowing in the expander (flow rate, temperatures and pressures at the inlet and outlet) but it is also determined by the temperature needed for a consumer and the initial temperature of the flow of the refrigeration-carrier being cooled. The conclusion was made that the expander-generator units can be used to create trigeneration plants both at major power plants and at small energy.

  9. Generation and hypermnesia.

    Science.gov (United States)

    Mulligan, N W

    2001-03-01

    The multifactor account of the generation effect makes detailed predictions about the effects of generation on item-specific and relational encoding, predictions confirmed in four experiments using a multiple-test methodology. In pure-list designs with unrelated study items, generation produced more interest item gains (indexing greater item-specific processing) and more interest item losses (indexing less relational processing) relative to the read condition. In a mixed-list design, generation produced more gains but did not affect losses. With categorically-related study items, generation produced more gains but fewer losses (indicating enhanced relational encoding). Generation consistently produced hypermnesia whereas reading did so only for related study items. Also, a significant generation effect emerged on later tests under conditions (between-subjects design, unrelated study items) which typically yield no generation effect. PMID:11294442

  10. Quantum random number generator

    Energy Technology Data Exchange (ETDEWEB)

    Pooser, Raphael C.

    2016-05-10

    A quantum random number generator (QRNG) and a photon generator for a QRNG are provided. The photon generator may be operated in a spontaneous mode below a lasing threshold to emit photons. Photons emitted from the photon generator may have at least one random characteristic, which may be monitored by the QRNG to generate a random number. In one embodiment, the photon generator may include a photon emitter and an amplifier coupled to the photon emitter. The amplifier may enable the photon generator to be used in the QRNG without introducing significant bias in the random number and may enable multiplexing of multiple random numbers. The amplifier may also desensitize the photon generator to fluctuations in power supplied thereto while operating in the spontaneous mode. In one embodiment, the photon emitter and amplifier may be a tapered diode amplifier.

  11. Meet the Millennial Generation.

    Science.gov (United States)

    O'Reilly, Brian

    2000-01-01

    The "Millennial Generation" has grown up with prosperity, working parents, the Internet, divorce, and Columbine. They are fundamentally different in outlook and ambition from preceding generations and have their own ideas about how they want to live and work. (JOW)

  12. Phagosomal TLR signaling upon Borrelia burgdorferi infection

    Science.gov (United States)

    Cervantes, Jorge L.; Hawley, Kelly L.; Benjamin, Sarah J.; Weinerman, Bennett; Luu, Stephanie M.; Salazar, Juan C.

    2014-01-01

    Internalization and degradation of live Bb within phagosomal compartments of monocytes, macrophages and dendritic cells (DCs), allows for the release of lipoproteins, nucleic acids and other microbial products, triggering a broad and robust inflammatory response. Toll-like receptors (TLRs) are key players in the recognition of spirochetal ligands from whole viable organisms (i.e., vita-PAMPs). Herein we will review the role of endosomal TLRs in the response to the Lyme disease spirochete. PMID:24904837

  13. Consolidated nuclear steam generator

    International Nuclear Information System (INIS)

    An improved system of providing power has a unique generating means for nuclear reactors with a number of steam generators in the form of replaceable modular units of the expendable type to attain the optimum in effective and efficient vaporization of fluid during the generating power. The system is most adaptable to undrground power plants and marine usage

  14. Consolidated nuclear steam generator

    International Nuclear Information System (INIS)

    The invention described relates to an improved system of providing power having a unique generating means of the nuclear reactor variety adapted with a plurality of steam generators in the form of replaceable modular units of the expendable type for the attainment of the optimum in effective and efficient vaporization of fluid during the process of generating power

  15. A simultaneous helical generator

    Energy Technology Data Exchange (ETDEWEB)

    Rickel, D.G.; Freeman, B.L.; Fowler, C.M.; Vorthman, J.E.; Marsh, S.P.

    1989-01-01

    A need is emerging for a class of short-pulse, high-voltage, magnetic flux compression generators (FCGs). It is desirable that these generators be compact, inexpensive and have modest prime power requirements. Toward this end several concepts have been worked on in our Laboratory, one of which is the conical helical generator described in this paper. 5 figs.

  16. Superconducting Power Generation

    CERN Document Server

    Rabinowitz, M

    2000-01-01

    The superconducting ac generator has the greatest potential for large-scale commercial application of superconductivity that can benefit the public. Electric power is a vital ingredient of modern society, and generation may be considered to be the vital ingredient of a power system. This articles gives background, and an insight into the physics and engineering of superconducting power generation.

  17. Neuro Language Generator

    Directory of Open Access Journals (Sweden)

    P. Dinadayalan

    2010-08-01

    Full Text Available ‘Neuro Language Generator using Finite State Machine’ is based on neural network and finite state machine. The fundamental properties of neural network along with the power of Turing machine prove how it can be implemented for formal language processing. This paper elaborates the conventional dynamical language generators, limitations of the conventional dynamical language generators and proposes a new architecture for formal language processing. Theconventional dynamical language generators used for neurallanguage generators is feedforward RNN. It expresses dynamical language generator using finite automaton and dynamical language generator using pushdown automaton. Conventional dynamical generators tend to have stability problem, incapable of network training and lack of memory. It is proposed that the new method ‘Neuro Language Generator using Finite State Machine’ solves most of the problems, which the traditional methods fail to do. The approach employs finitestate technology for a RNN in the task of learning to achieve stability in network structure. RNN architecture performs the same computation as a Turing machine. The RNN architecture acts as a language generator, which accepts formal language. Neuro Language Generator is a RNN that uses feedback connections. NLG can be used to solve more complicated problems compared to traditional dynamical generator.

  18. Event generators at BESⅢ

    Institute of Scientific and Technical Information of China (English)

    PING Rong-Gang

    2008-01-01

    We present a brief remark and introduction to event generators for tau-charm physics currently used at BESⅢ,including KKMC,BesEvtGen,Bhlumi,Bhwide,Babayaga and inclusive Monte-Carlo event generators.This paper provides basic information on event generators for BESⅢ users.

  19. Motor/generator

    Science.gov (United States)

    Hickam, Christopher Dale

    2008-05-13

    A motor/generator is provided for connecting between a transmission input shaft and an output shaft of a prime mover. The motor/generator may include a motor/generator housing, a stator mounted to the motor/generator housing, a rotor mounted at least partially within the motor/generator housing and rotatable about a rotor rotation axis, and a transmission-shaft coupler drivingly coupled to the rotor. The transmission-shaft coupler may include a clamp, which may include a base attached to the rotor and a plurality of adjustable jaws.

  20. Solar thermoelectric generator

    Science.gov (United States)

    Toberer, Eric S.; Baranowski, Lauryn L.; Warren, Emily L.

    2016-05-03

    Solar thermoelectric generators (STEGs) are solid state heat engines that generate electricity from concentrated sunlight. A novel detailed balance model for STEGs is provided and applied to both state-of-the-art and idealized materials. STEGs can produce electricity by using sunlight to heat one side of a thermoelectric generator. While concentrated sunlight can be used to achieve extremely high temperatures (and thus improved generator efficiency), the solar absorber also emits a significant amount of black body radiation. This emitted light is the dominant loss mechanism in these generators. In this invention, we propose a solution to this problem that eliminates virtually all of the emitted black body radiation. This enables solar thermoelectric generators to operate at higher efficiency and achieve said efficient with lower levels of optical concentration. The solution is suitable for both single and dual axis solar thermoelectric generators.

  1. Electric generators: Roesel

    Energy Technology Data Exchange (ETDEWEB)

    Segaser, C.L.

    1977-04-01

    A new and unique type of electrical generator is described that will provide constant frequency output (within 0.01% or better) regardless of rotational speed variations. It accomplishes this with no added bulk over conventional generators, and with excellent efficiency. The same principle that permits constant frequency output also provides the means for output voltage regulation with varying drive speed and/or varying load. Onsite power generation aspects of the Integrated Community Energy Systems (ICES) concept include the requirement to follow community electric loads and the possible use of internal combustion piston engines with waste heat recovery to drive electric generators. The diesel engine is a prime candidate from commercially available technologies for which part-load shaft efficiency is better at reduced speed than for constant-speed operation required by conventional AC generators. The unique characteristics of the Roesel generator allow prime mover speed to decrease with load and offer improved engine-generator system efficiency in ICES applications.

  2. Electric power generation. Thermal power generating systems

    International Nuclear Information System (INIS)

    This is a manuscript for a lecture contents: 1) Steam power and fundamentals of the steam power process, 3) conventional, nuclear and other steam generation processes, 4) cooling systems for steam power plants, 5) gas turbine power plants and combined-cycle power plants, 6) cogeneration, 7) development of thermal power plants and environmental effects. (GL)

  3. Generational Accounting in Iran

    Directory of Open Access Journals (Sweden)

    Mahdi Salehi

    2013-09-01

    Full Text Available The aim of this paper is to study of the generation accounts for Iranian’s generation. We applied the method of Auerbach, Gokhale and Kotlihoff (1991 on the period 1967-2008 in Iran. Our calculation shows with compare to industrial countries, fiscal burden for Iranian’s population is very chip and that depend on fiscal system in Iran. Except the recent years the rate of tax in Iran has been very low. The generation account for the old people (40 olds is 2117 $ but the future generation (t+1 is 36985 $. The share of male and female, during the years, in this burden is similar. Fiscal burden for Iranian’s generation is low but this population should support other burden that calls inflation. Because when the government do not receive the tax income, a low generation account transfer to price general level.

  4. Quantum Random Number Generators

    OpenAIRE

    Herrero-Collantes, Miguel; Garcia-Escartin, Juan Carlos

    2016-01-01

    Random numbers are a fundamental resource in science and engineering with important applications in simulation and cryptography. The inherent randomness at the core of quantum mechanics makes quantum systems a perfect source of entropy. Quantum random number generation is one of the most mature quantum technologies with many alternative generation methods. We discuss the different technologies in quantum random number generation from the early devices based on radioactive decay to the multipl...

  5. Modular Stirling Radioisotope Generator

    Science.gov (United States)

    Schmitz, Paul C.; Mason, Lee S.; Schifer, Nicholas A.

    2016-01-01

    High-efficiency radioisotope power generators will play an important role in future NASA space exploration missions. Stirling Radioisotope Generators (SRGs) have been identified as a candidate generator technology capable of providing mission designers with an efficient, high-specific-power electrical generator. SRGs high conversion efficiency has the potential to extend the limited Pu-238 supply when compared with current Radioisotope Thermoelectric Generators (RTGs). Due to budgetary constraints, the Advanced Stirling Radioisotope Generator (ASRG) was canceled in the fall of 2013. Over the past year a joint study by NASA and the Department of Energy (DOE) called the Nuclear Power Assessment Study (NPAS) recommended that Stirling technologies continue to be explored. During the mission studies of the NPAS, spare SRGs were sometimes required to meet mission power system reliability requirements. This led to an additional mass penalty and increased isotope consumption levied on certain SRG-based missions. In an attempt to remove the spare power system, a new generator architecture is considered, which could increase the reliability of a Stirling generator and provide a more fault-tolerant power system. This new generator called the Modular Stirling Radioisotope Generator (MSRG) employs multiple parallel Stirling convertor/controller strings, all of which share the heat from the General Purpose Heat Source (GPHS) modules. For this design, generators utilizing one to eight GPHS modules were analyzed, which provided about 50 to 450 W of direct current (DC) to the spacecraft, respectively. Four Stirling convertors are arranged around each GPHS module resulting in from 4 to 32 Stirling/controller strings. The convertors are balanced either individually or in pairs, and are radiatively coupled to the GPHS modules. Heat is rejected through the housing/radiator, which is similar in construction to the ASRG. Mass and power analysis for these systems indicate that specific

  6. Developing a derivatives generator

    Directory of Open Access Journals (Sweden)

    Mircea Petic

    2016-01-01

    Full Text Available The article intends to highlight the particularities of the derivational morphology mechanisms that will help in lexical resources extension. Some computing approaches for derivational morphology are given for several languages, inclusively for Romanian. This paper deals with some preprocessing particularities, that are needed in the process of automatic generation. Then, generative mechanisms are presented in the form of derivational formal rules separately for prefixation and suffixation. The article ends with several approaches in automatic new generated words validation.

  7. Generative Software Development

    OpenAIRE

    Rumpe, Bernhard; Schindler, Martin; Völkel, Steven; Weisemöller, Ingo

    2014-01-01

    Generation of software from modeling languages such as UML and domain specific languages (DSLs) has become an important paradigm in software engineering. In this contribution, we present some positions on software development in a model based, generative manner based on home grown DSLs as well as the UML. This includes development of DSLs as well as development of models in these languages in order to generate executable code, test cases or models in different languages. Development of formal...

  8. VOLTAGE REGULATORS ASYNCHRONOUS GENERATORS

    OpenAIRE

    Grigorash O. V.; Bogatyrev N. I.; Hitskova A. O.

    2015-01-01

    A promising is currently the use of asynchronous generators with capacitive excitation as a source of electricity in stand-alone power systems. Drive asynchronous generators may exercise as a thermal engine and wind wheel wind power plant or turbines of small hydropower plants. The article discusses the structural and schematics of voltage stabilizers and frequency of asynchronous generators with improved operational and technical specifications. Technical novelty of design solutions of the m...

  9. Distributed generation hits market

    International Nuclear Information System (INIS)

    The pace at which vendors are developing and marketing gas turbines and reciprocating engines for small-scale applications may signal the widespread growth of distributed generation. Loosely defined to refer to applications in which power generation equipment is located close to end users who have near-term power capacity needs, distributed generation encompasses a broad range of technologies and load requirements. Disagreement is inevitable, but many industry observers associate distributed generation with applications anywhere from 25 kW to 25 MW. Ten years ago, distributed generation users only represented about 2% of the world market. Today, that figure has increased to about 4 or 5%, and probably could settle in the 20% range within a 3-to-5-year period, according to Michael Jones, San Diego, Calif.-based Solar Turbines Inc. power generation marketing manager. The US Energy Information Administration predicts about 175 GW of generation capacity will be added domestically by 2010. If 20% comes from smaller plants, distributed generation could account for about 35 GW. Even with more competition, it's highly unlikely distributed generation will totally replace current market structures and central stations. Distributed generation may be best suited for making market inroads when and where central systems need upgrading, and should prove its worth when the system can't handle peak demands. Typical applications include small reciprocating engine generators at remote customer sites or larger gas turbines to boost the grid. Additional market opportunities include standby capacity, peak shaving, power quality, cogeneration and capacity rental for immediate demand requirements. Integration of distributed generation systems--using gas-fueled engines, gas-fired combustion engines and fuel cells--can upgrade power quality for customers and reduce operating costs for electric utilities

  10. Distributed generation systems model

    Energy Technology Data Exchange (ETDEWEB)

    Barklund, C.R.

    1994-12-31

    A slide presentation is given on a distributed generation systems model developed at the Idaho National Engineering Laboratory, and its application to a situation within the Idaho Power Company`s service territory. The objectives of the work were to develop a screening model for distributed generation alternatives, to develop a better understanding of distributed generation as a utility resource, and to further INEL`s understanding of utility concerns in implementing technological change.

  11. Nuclear steam generator

    International Nuclear Information System (INIS)

    A nuclear steam generator has a blowdown pump arranged to pump water from the blowdown line through a filter for return to the steam generator. The piping is arranged so that the pump may operate to reverse the direction of pumping through the blowdown line whereby reverse circulation may be established during wet lay up of the steam generator. A blower is arranged to withdraw nitrogen from an upper elevation in the steam generator and inject the nitrogen into the blowdown line in combination with the pumped reverse circulation during wet lay up. (author)

  12. Gearless wind power generator

    Energy Technology Data Exchange (ETDEWEB)

    Soederlund, L.; Ridanpaeae, P.; Vihriaelae, H.; Peraelae, R. [Tampere Univ. of Technology (Finland). Lab. of Electricity and Magnetism

    1998-12-31

    During the wind power generator project a design algorithm for a gearless permanent magnet generator with an axially orientated magnetic flux was developed and a 10 kW model machine was constructed. Utilising the test results a variable wind speed system of 100 kW was designed that incorporates a permanent magnet generator, a frequency converter and a fuzzy controller. This system produces about 5-15% more energy than existing types and stresses to the blades are minimised. The type of generator designed in the project represents in general a gearless solution for slow-speed electrical drives. (orig.)

  13. Thermophotovoltaic energy generation

    Energy Technology Data Exchange (ETDEWEB)

    Celanovic, Ivan; Chan, Walker; Bermel, Peter; Yeng, Adrian Y. X.; Marton, Christopher; Ghebrebrhan, Michael; Araghchini, Mohammad; Jensen, Klavs F.; Soljacic, Marin; Joannopoulos, John D.; Johnson, Steven G.; Pilawa-Podgurski, Robert; Fisher, Peter

    2015-08-25

    Inventive systems and methods for the generation of energy using thermophotovoltaic cells are described. Also described are systems and methods for selectively emitting electromagnetic radiation from an emitter for use in thermophotovoltaic energy generation systems. In at least some of the inventive energy generation systems and methods, a voltage applied to the thermophotovoltaic cell (e.g., to enhance the power produced by the cell) can be adjusted to enhance system performance. Certain embodiments of the systems and methods described herein can be used to generate energy relatively efficiently.

  14. Generational Accounting in Iran

    OpenAIRE

    Mahdi Salehi; Mahdi Behnameh; Monireh Najayian

    2013-01-01

    The aim of this paper is to study of the generation accounts for Iranian’s generation. We applied the method of Auerbach, Gokhale and Kotlihoff (1991) on the period 1967-2008 in Iran. Our calculation shows with compare to industrial countries, fiscal burden for Iranian’s population is very chip and that depend on fiscal system in Iran. Except the recent years the rate of tax in Iran has been very low. The generation account for the old people (40 olds) is 2117 $ but the future generation (t+1...

  15. SMUG: Scientific Music Generator

    DEFF Research Database (Denmark)

    Scirea, Marco; A B Barros, Gabriella; Togelius, Julian;

    2015-01-01

    Music is based on the real world. Composers use their day-to-day lives as inspiration to create rhythm and lyrics. Procedural music generators are capable of creating good quality pieces, and while some already use the world as inspiration, there is still much to be explored in this. We describe a...... system to generate lyrics and melodies from real-world data, in particular from academic papers. Through this we want to create a playful experience and establish a novel way of generating content (textual and musical) that could be applied to other domains, in particular to games. For melody generation...

  16. Next Generation Sequencing Demands Next Generation Phenotyping

    OpenAIRE

    Hennekam, Raoul CM; Biesecker, Leslie G

    2012-01-01

    Next-Generation Sequencing (NGS) is the most powerful diagnostic tool since the roentgenogram. NGS will facilitate diagnosis on a massive scale –allowing interrogation of all genes in a single assay. It has been suggested that NGS will decrease the need for phenotyping in general, and medical geneticists in particular. We argue that NGS will shift focus and approach of phenotyping. We predict that NGS performed for diagnostic purposes will yield variants in several genes, and consequences of ...

  17. Entanglement generation in continuously coupled parametric generators

    OpenAIRE

    Herec, Jiri; Fiurasek, Jaromir; Mista Jr., Ladislav

    2003-01-01

    We investigate a compact source of entanglement. This device is composed of a pair of linearly coupled nonlinear waveguides operating by means of degenerate parametric downconversion. For the vacuum state at the input the generalized squeeze variance and logarithmic negativity are used to quantify the amount of nonclassicality and entanglement of output beams. Squeezing and entanglement generation for various dynamical regimes of the device are discussed.

  18. Generativity and Flourishing

    Science.gov (United States)

    Snow, Nancy

    2015-01-01

    The psychological construct of "generativity" was introduced by Erik Erikson in "Childhood and Society" in 1950. This rich and complex notion encompasses the constellation of desires, concerns and commitments that motivate individuals and societies to pass on legacies to future generations. "Flourishing," which means,…

  19. Aerodynamically shaped vortex generators

    DEFF Research Database (Denmark)

    Hansen, Martin Otto Laver; Velte, Clara Marika; Øye, Stig;

    2016-01-01

    An aerodynamically shaped vortex generator has been proposed, manufactured and tested in a wind tunnel. The effect on the overall performance when applied on a thick airfoil is an increased lift to drag ratio compared with standard vortex generators. Copyright © 2015 John Wiley & Sons, Ltd....

  20. When Generations Collide

    Science.gov (United States)

    Fogg, Piper

    2008-01-01

    When four generations converge in the academic workplace, it can create serious culture clashes. It is happening across college campuses--in offices as diverse as admissions, student affairs, legal affairs, and technology. It is especially striking in the faculty ranks, where generational challenges have extra significance amid recruiting efforts,…

  1. Spatial Process Generation

    OpenAIRE

    Kroese, Dirk P.; Botev, Zdravko I.

    2013-01-01

    The generation of random spatial data on a computer is an important tool for understanding the behavior of spatial processes. In this paper we describe how to generate realizations from the main types of spatial processes, including Gaussian and Markov random fields, point processes, spatial Wiener processes, and Levy fields. Concrete MATLAB code is provided.

  2. Replacement nuclear steam generators

    International Nuclear Information System (INIS)

    This paper reviews past and current practices in the replacement of nuclear steam generators. Plants where steam generator replacement has occurred are reviewed to see what changes have been made, and how the evolving technology has significantly reduced outage time and man-rem exposures. Current preferences in design and material are reviewed. 3 refs., 3 tabs., 2 figs

  3. Nanowires for energy generation

    International Nuclear Information System (INIS)

    As a result of their morphology, nanowires bring new properties and the promise of performance for a range of electronic devices. This review looks into the properties of nanowires and the multiple ways in which they have been exploited for energy generation, from photovoltaics to piezoelectric generators. (paper)

  4. Generative Processes: Thick Drawing

    Science.gov (United States)

    Wallick, Karl

    2012-01-01

    This article presents techniques and theories of generative drawing as a means for developing complex content in architecture design studios. Appending the word "generative" to drawing adds specificity to the most common representation tool and clarifies that such drawings are not singularly about communication or documentation but are also…

  5. The Last Generation

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    "Mommy,"said the little boy,"do you know the beauliful vase inthe dining room that has been handed down from generation to genera-tion?""Yes,"said his mother."What about it?""Well,the last generation just dropped it."

  6. Event generator overview

    International Nuclear Information System (INIS)

    Due to their ability to provide detailed and quantitative predictions, the event generators have become an important part of studying relativistic heavy ion physics and of designing future experiments. In this talk, the author will briefly summarize recent progress in developing event generators for the relativistic heavy ion collisions

  7. Generation of Transgenic Mice

    OpenAIRE

    Cho, Andrew; Haruyama, Naoto; Kulkarni, Ashok B.

    2009-01-01

    This unit describes detailed step-by-step protocols, reagents, and equipment required for successful generation of transgenic mice using pronuclear injection. The experimental methods and practical tips given here will help guide beginners in understanding what is required and what to avoid in these standard protocols for efficiently generating transgenic mice.

  8. Procedure generation and verification

    International Nuclear Information System (INIS)

    The Department of Energy has used Artificial Intelligence of ''AI'' concepts to develop two powerful new computer-based techniques to enhance safety in nuclear applications. The Procedure Generation System, and the Procedure Verification System, can be adapted to other commercial applications, such as a manufacturing plant. The Procedure Generation System can create a procedure to deal with the off-normal condition. The operator can then take correct actions on the system in minimal time. The Verification System evaluates the logic of the Procedure Generator's conclusions. This evaluation uses logic techniques totally independent of the Procedure Generator. The rapid, accurate generation and verification of corrective procedures can greatly reduce the human error, possible in a complex (stressful/high stress) situation

  9. Experience and Its Generation

    Institute of Scientific and Technical Information of China (English)

    Chen Youqing

    2006-01-01

    Experience iS an activity that arouses emotions and generates meanings based on vivid sensation and profound compreh ension.It iS emotional,meaningful,and personal,playing a key role in the course of forming and developing one'S qualities.The psychological process of experience generation consists of such links as sensing things,arousing emotions,promoting comprehension and association,generating insights and meanings,and deepening emotional responses.Undergoing things personally by means of direct sensation,taking part in activities,and living life are the most important preconditions of experience generation.Emotional influence,situational edification,and arts edification ale extemal factors that induce experience generation.

  10. TFTR Motor Generator

    International Nuclear Information System (INIS)

    A general description is given of 475 MVA pulsed motor generators for TFTR at Princeton Plasma Physics Laboratory. Two identical generators operating in parallel are capable of supplying 950 MVA for an equivalent square pulse of 6.77 seconds and 4,500 MJ at 0.7 power factor to provide the energy for the pulsed electrical coils and heating system for TFTR. The description includes the operational features of the 15,000 HP wound rotor motors driving each generator with its starting equipment and cycloconverter for controlling speed, power factor, and regulating line voltage during load pulsing where the generator speed changes from 87.5 to 60 Hz frequency variation to provide the 4,500 MJ or energy. The special design characteristics such as fatigue stress calculations for 106 cycles of operation, forcing factor on exciter to provide regulation, and low generator impedance are reviewed

  11. Steam generator life management

    International Nuclear Information System (INIS)

    Steam generators are a critical component of a nuclear power reactor, and can contribute significantly to station unavailability, as has been amply demonstrated in Pressurized Water Reactors (PWRs). CANDU steam generators are not immune to steam generator degradation, and the variety of CANDU steam generator designs and tube materials has led to some unexpected challenges. However, aggressive remedial actions, and careful proactive maintenance activities, have led to a decrease in steam generator-related station unavailability of Canadian CANDUs. AECL and the CANDU utilities have defined programs that will enable existing or new steam generators to operate effectively for 40 years. Research and development work covers corrosion and mechanical degradation of tube bundles and internals, chemistry, thermal hydraulics, fouling, inspection and cleaning, as well as provision for specially tool development for specific problem solving. A major driving force is development of CANDU-specific fitness-for-service guidelines, including appropriate inspection and monitoring technology to measure steam generator condition. Longer-range work focuses on development of intelligent on-line monitoring for the feedwater system and steam generator. New designs have reduced risk of corrosion and fouling, are more easily inspected and cleaned, and are less susceptible to mechanical damage. The Canadian CANDU utilities have developed programs for remedial actions to combat degradation of performance (Gentilly-2, Point Lepreau, Bruce A/B, Pickering A/B), and have developed strategic plans to ensure that good future operation is ensured. This report shows how recent advances in cleaning technology are integrated into a life management strategy, discusses downcomer flow measurement as a means of monitoring steam generator condition, and describes recent advances in hideout return as a life management tool. The research and development program, as well as operating experience, has identified

  12. Steam generator life management

    Energy Technology Data Exchange (ETDEWEB)

    Tapping, R.L. [Atomic Energy of Canada Limited, Chalk River, Ontario (Canada); Nickerson, J. [Atomic Energy of Canada Limited, Mississauga, Ontario (Canada); Spekkens, P.; Maruska, C. [Ontario Hydro, Toronto, Ontario (Canada)

    1998-01-01

    Steam generators are a critical component of a nuclear power reactor, and can contribute significantly to station unavailability, as has been amply demonstrated in Pressurized Water Reactors (PWRs). CANDU steam generators are not immune to steam generator degradation, and the variety of CANDU steam generator designs and tube materials has led to some unexpected challenges. However, aggressive remedial actions, and careful proactive maintenance activities, have led to a decrease in steam generator-related station unavailability of Canadian CANDUs. AECL and the CANDU utilities have defined programs that will enable existing or new steam generators to operate effectively for 40 years. Research and development work covers corrosion and mechanical degradation of tube bundles and internals, chemistry, thermal hydraulics, fouling, inspection and cleaning, as well as provision for specially tool development for specific problem solving. A major driving force is development of CANDU-specific fitness-for-service guidelines, including appropriate inspection and monitoring technology to measure steam generator condition. Longer-range work focuses on development of intelligent on-line monitoring for the feedwater system and steam generator. New designs have reduced risk of corrosion and fouling, are more easily inspected and cleaned, and are less susceptible to mechanical damage. The Canadian CANDU utilities have developed programs for remedial actions to combat degradation of performance (Gentilly-2, Point Lepreau, Bruce A/B, Pickering A/B), and have developed strategic plans to ensure that good future operation is ensured. This report shows how recent advances in cleaning technology are integrated into a life management strategy, discusses downcomer flow measurement as a means of monitoring steam generator condition, and describes recent advances in hideout return as a life management tool. The research and development program, as well as operating experience, has identified

  13. VOLTAGE REGULATORS ASYNCHRONOUS GENERATORS

    Directory of Open Access Journals (Sweden)

    Grigorash O. V.

    2015-06-01

    Full Text Available A promising is currently the use of asynchronous generators with capacitive excitation as a source of electricity in stand-alone power systems. Drive asynchronous generators may exercise as a thermal engine and wind wheel wind power plant or turbines of small hydropower plants. The article discusses the structural and schematics of voltage stabilizers and frequency of asynchronous generators with improved operational and technical specifications. Technical novelty of design solutions of the magnetic system and stabilizers asynchronous generator of electricity parameters confirmed by the patents for the invention of the Russian Federation. The proposed technical solution voltage stabilizer asynchronous generators, can reduce the weight of the block capacitors excitation and reactive power compensation, as well as to simplify the control system power circuit which has less power electronic devices. For wind power plants it is an important issue not only to stabilize the voltage of the generator, but also the frequency of the current. Recommend functionality stabilizer schemes parameters of electric power made for direct frequency converters with artificial and natural switching power electronic devices. It is also proposed as part of stabilization systems use single-phase voltage, three-phase transformers with rotating magnetic field, reduce the level of electromagnetic interference generated by power electronic devices for switching, enhance the efficiency and reliability of the stabilizer.

  14. Spin hydrodynamic generation

    Science.gov (United States)

    Takahashi, R.; Matsuo, M.; Ono, M.; Harii, K.; Chudo, H.; Okayasu, S.; Ieda, J.; Takahashi, S.; Maekawa, S.; Saitoh, E.

    2016-01-01

    Magnetohydrodynamic generation is the conversion of fluid kinetic energy into electricity. Such conversion, which has been applied to various types of electric power generation, is driven by the Lorentz force acting on charged particles and thus a magnetic field is necessary. On the other hand, recent studies of spintronics have revealed the similarity between the function of a magnetic field and that of spin-orbit interactions in condensed matter. This suggests the existence of an undiscovered route to realize the conversion of fluid dynamics into electricity without using magnetic fields. Here we show electric voltage generation from fluid dynamics free from magnetic fields; we excited liquid-metal flows in a narrow channel and observed longitudinal voltage generation in the liquid. This voltage has nothing to do with electrification or thermoelectric effects, but turned out to follow a universal scaling rule based on a spin-mediated scenario. The result shows that the observed voltage is caused by spin-current generation from a fluid motion: spin hydrodynamic generation. The observed phenomenon allows us to make mechanical spin-current and electric generators, opening a door to fluid spintronics.

  15. OMG: Open Molecule Generator

    Directory of Open Access Journals (Sweden)

    Peironcely Julio E

    2012-09-01

    Full Text Available Abstract Computer Assisted Structure Elucidation has been used for decades to discover the chemical structure of unknown compounds. In this work we introduce the first open source structure generator, Open Molecule Generator (OMG, which for a given elemental composition produces all non-isomorphic chemical structures that match that elemental composition. Furthermore, this structure generator can accept as additional input one or multiple non-overlapping prescribed substructures to drastically reduce the number of possible chemical structures. Being open source allows for customization and future extension of its functionality. OMG relies on a modified version of the Canonical Augmentation Path, which grows intermediate chemical structures by adding bonds and checks that at each step only unique molecules are produced. In order to benchmark the tool, we generated chemical structures for the elemental formulas and substructures of different metabolites and compared the results with a commercially available structure generator. The results obtained, i.e. the number of molecules generated, were identical for elemental compositions having only C, O and H. For elemental compositions containing C, O, H, N, P and S, OMG produces all the chemically valid molecules while the other generator produces more, yet chemically impossible, molecules. The chemical completeness of the OMG results comes at the expense of being slower than the commercial generator. In addition to being open source, OMG clearly showed the added value of constraining the solution space by using multiple prescribed substructures as input. We expect this structure generator to be useful in many fields, but to be especially of great importance for metabolomics, where identifying unknown metabolites is still a major bottleneck.

  16. Third generation coaching

    DEFF Research Database (Denmark)

    Stelter, Reinhard

    2014-01-01

    Third generation coaching unfolds a new universe for coaching and coaching psychology in the framework of current social research, new learning theories and discourses about personal leadership. Third generation coaching views coaching in a societal perspective. Coaching has become important as a....... It is the author’s ambition to elevate coaching and coaching psychology to a new professional level with a new agenda. The term “third generation coaching” may be understood as a sort of manifesto – not in a normative sense but as an invitation to reconsider the main objective of coaching in late- or...... post-modern society....

  17. Superconducting current generators

    International Nuclear Information System (INIS)

    After a brief summary of the principle of energy storage and liberation with superconducting coils,two current generators are described that create currents in the range 600 to 1400 A, used for two storage experiments of 25 kJ and 50 kJ respectively. The two current generators are: a) a flux pump and b) a superconducting transformer. Both could be developed into more powerful units. The study shows the advantage of the transformer over the flux pump in order to create large currents. The efficiencies of the two generators are 95 per cent and 40 to 60 per cent respectively. (author)

  18. Coal-fired generation

    CERN Document Server

    Breeze, Paul

    2015-01-01

    Coal-Fired Generation is a concise, up-to-date and readable guide providing an introduction to this traditional power generation technology. It includes detailed descriptions of coal fired generation systems, demystifies the coal fired technology functions in practice as well as exploring the economic and environmental risk factors. Engineers, managers, policymakers and those involved in planning and delivering energy resources will find this reference a valuable guide, to help establish a reliable power supply address social and economic objectives. Focuses on the evolution of the traditio

  19. Definition of distributed generation

    International Nuclear Information System (INIS)

    Today, power systems in many countries are restructured and deregulated and it is expected the small scale generators or Distributed Generations (DG), such as Micro turbines, PV, fuel cells, wind turbines and so on will play important role in power system. So it is necessary to be well defined and described. Generally, DGs are defined as electric power generators that are connected to distribution networks or on the customer side of networks. This paper presents a definition of DGs with considering some important aspects, and after that introduces some different type of DGs

  20. Graph Generator Survey

    Energy Technology Data Exchange (ETDEWEB)

    Lothian, Josh [ORNL; Powers, Sarah S [ORNL; Sullivan, Blair D [ORNL; Baker, Matthew B [ORNL; Schrock, Jonathan [ORNL; Poole, Stephen W [ORNL

    2013-12-01

    The benchmarking effort within the Extreme Scale Systems Center at Oak Ridge National Laboratory seeks to provide High Performance Computing benchmarks and test suites of interest to the DoD sponsor. The work described in this report is a part of the effort focusing on graph generation. A previously developed benchmark, SystemBurn, allowed the emulation of dierent application behavior profiles within a single framework. To complement this effort, similar capabilities are desired for graph-centric problems. This report examines existing synthetic graph generator implementations in preparation for further study on the properties of their generated synthetic graphs.

  1. Generating ethnographic research questions

    DEFF Research Database (Denmark)

    Friberg, Torbjörn

    2015-01-01

    drawing on the conceptual history of anthropology, the aim of this article is to generate ethnographic-oriented research questions concerned with higher education. The first part of the article provides an ethnographic background, while the second part focuses on Paul Willis's reasoning on ethnographic...... imagination, as a prerequisite for generating alternative research questions. The third part makes explicit anthropologist Maurice Godelier's theoretical imagination, carving out some specific theoretical parts which may be used in the generating process. The conclusion then suggests a number of questions to...

  2. Power generation technologies

    CERN Document Server

    Breeze, Paul

    2014-01-01

    The new edition of Power Generation Technologies is a concise and readable guide that provides an introduction to the full spectrum of currently available power generation options, from traditional fossil fuels and the better established alternatives such as wind and solar power, to emerging renewables such as biomass and geothermal energy. Technology solutions such as combined heat and power and distributed generation are also explored. However, this book is more than just an account of the technologies - for each method the author explores the economic and environmental costs and risk factor

  3. Synthetic guide star generation

    Science.gov (United States)

    Payne, Stephen A [Castro Valley, CA; Page, Ralph H [Castro Valley, CA; Ebbers, Christopher A [Livermore, CA; Beach, Raymond J [Livermore, CA

    2008-06-10

    A system for assisting in observing a celestial object and providing synthetic guide star generation. A lasing system provides radiation at a frequency at or near 938 nm and radiation at a frequency at or near 1583 nm. The lasing system includes a fiber laser operating between 880 nm and 960 nm and a fiber laser operating between 1524 nm and 1650 nm. A frequency-conversion system mixes the radiation and generates light at a frequency at or near 589 nm. A system directs the light at a frequency at or near 589 nm toward the celestial object and provides synthetic guide star generation.

  4. Next generation mobile broadcasting

    CERN Document Server

    Gómez-Barquero, David

    2013-01-01

    Next Generation Mobile Broadcasting provides an overview of the past, present, and future of mobile multimedia broadcasting. The first part of the book-Mobile Broadcasting Worldwide-summarizes next-generation mobile broadcasting technologies currently available. This part covers the evolutions of the Japanese mobile broadcasting standard ISDB-T One-Seg, ISDB-Tmm and ISDB-TSB; the evolution of the South Korean T-DMB mobile broadcasting technology AT-DMB; the American mobile broadcasting standard ATSC-M/H; the Chinese broadcasting technologies DTMB and CMMB; second-generation digital terrestrial

  5. Auxiliary Deep Generative Models

    DEFF Research Database (Denmark)

    Maaløe, Lars; Sønderby, Casper Kaae; Sønderby, Søren Kaae;

    2016-01-01

    Deep generative models parameterized by neural networks have recently achieved state-of-the-art performance in unsupervised and semi-supervised learning. We extend deep generative models with auxiliary variables which improves the variational approximation. The auxiliary variables leave the...... generative model unchanged but make the variational distribution more expressive. Inspired by the structure of the auxiliary variable we also propose a model with two stochastic layers and skip connections. Our findings suggest that more expressive and properly specified deep generative models converge...... faster with better results. We show state-of-the-art performance within semi-supervised learning on MNIST (0.96%), SVHN (16.61%) and NORB (9.40%) datasets....

  6. Analysis of generation costs

    International Nuclear Information System (INIS)

    The (UK) Central Electricity Generating Board has calculated the generation costs of a range of existing power stations for 1981-82, and for their lifetime to date, and the likely costs for their whole lifetime. Expected lifetime generation costs for power stations under construction and those which may be built in the future have also been estimated. The case for any future station is based on an assessment of its net effective cost expressed in Pound per kilowatt of capacity and this technique has been applied to stations under construction also. The results of these calculations, including the continuation for 1981-82 of the series of single year generation costs on the basis of monetary interest cost which the Board has published in the past, are presented. Coal, oil and nuclear stations are included. (author)

  7. Standard Firebrand Generator

    Data.gov (United States)

    Federal Laboratory Consortium — This apparatus, developed at EL, has been constructed to generate a controlled and repeatable size and mass distribution of glowing firebrands. The purpose of NIST...

  8. Financing Distributed Generation

    International Nuclear Information System (INIS)

    This paper introduces the engineer who is undertaking distributed generation projects to a wide range of financing options. Distributed generation systems (such as internal combustion engines, small gas turbines, fuel cells and photovoltaics) all require an initial investment, which is recovered over time through revenues or savings. An understanding of the cost of capital and financing structures helps the engineer develop realistic expectations and not be offended by the common requirements of financing organizations. This paper discusses several mechanisms for financing distributed generation projects: appropriations; debt (commercial bank loan); mortgage; home equity loan; limited partnership; vendor financing; general obligation bond; revenue bond; lease; Energy Savings Performance Contract; utility programs; chauffage (end-use purchase); and grants. The paper also discusses financial strategies for businesses focusing on distributed generation: venture capital; informal investors (''business angels''); bank and debt financing; and the stock market

  9. French steam generator

    International Nuclear Information System (INIS)

    After recalling the potential damage mode of tubes of steam generator, the author recalls the safety criteria used in France. The improvements and the process of damage prejudice and reparation for tubular bundle are presented

  10. Kernel Oriented Generator Distribution

    OpenAIRE

    Bekker, A.; Arashi, M.

    2014-01-01

    Matrix variate beta (MVB) distributions are used in different fields of hypothesis testing, multivariate correlation analysis, zero regression, canonical correlation analysis and etc. In this approach a unified methodology is proposed to generate matrix variate distributions by combining the kernel of MVB distributions of different types with an unknown Borel measurable function of trace operator over matrix space, called generator component. The latter component is a principal element of the...

  11. Concentrated solar thermoelectric generators

    OpenAIRE

    Baranowski, Lauryn L.; Snyder, G. Jeffrey; Toberer, Eric S.

    2012-01-01

    Solar thermoelectric generators (STEGs) are solid state heat engines that generate electricity from concentrated sunlight. In this paper, we develop a novel detailed balance model for STEGs and apply this model to both state-of-the-art and idealized materials. This model uses thermoelectric compatibility theory to provide analytic solutions to device efficiency in idealized materials with temperature-dependent properties. The results of this modeling allow us to predict maximum theoretical ST...

  12. Steam generator tube failures

    Energy Technology Data Exchange (ETDEWEB)

    MacDonald, P.E.; Shah, V.N.; Ward, L.W.; Ellison, P.G.

    1996-04-01

    A review and summary of the available information on steam generator tubing failures and the impact of these failures on plant safety is presented. The following topics are covered: pressurized water reactor (PWR), Canadian deuterium uranium (CANDU) reactor, and Russian water moderated, water cooled energy reactor (VVER) steam generator degradation, PWR steam generator tube ruptures, the thermal-hydraulic response of a PWR plant with a faulted steam generator, the risk significance of steam generator tube rupture accidents, tubing inspection requirements and fitness-for-service criteria in various countries, and defect detection reliability and sizing accuracy. A significant number of steam generator tubes are defective and are removed from service or repaired each year. This wide spread damage has been caused by many diverse degradation mechanisms, some of which are difficult to detect and predict. In addition, spontaneous tube ruptures have occurred at the rate of about one every 2 years over the last 20 years, and incipient tube ruptures (tube failures usually identified with leak detection monitors just before rupture) have been occurring at the rate of about one per year. These ruptures have caused complex plant transients which have not always been easy for the reactor operators to control. Our analysis shows that if more than 15 tubes rupture during a main steam line break, the system response could lead to core melting. Although spontaneous and induced steam generator tube ruptures are small contributors to the total core damage frequency calculated in probabilistic risk assessments, they are risk significant because the radionuclides are likely to bypass the reactor containment building. The frequency of steam generator tube ruptures can be significantly reduced through appropriate and timely inspections and repairs or removal from service.

  13. Steam generator tube failures

    International Nuclear Information System (INIS)

    A review and summary of the available information on steam generator tubing failures and the impact of these failures on plant safety is presented. The following topics are covered: pressurized water reactor (PWR), Canadian deuterium uranium (CANDU) reactor, and Russian water moderated, water cooled energy reactor (VVER) steam generator degradation, PWR steam generator tube ruptures, the thermal-hydraulic response of a PWR plant with a faulted steam generator, the risk significance of steam generator tube rupture accidents, tubing inspection requirements and fitness-for-service criteria in various countries, and defect detection reliability and sizing accuracy. A significant number of steam generator tubes are defective and are removed from service or repaired each year. This wide spread damage has been caused by many diverse degradation mechanisms, some of which are difficult to detect and predict. In addition, spontaneous tube ruptures have occurred at the rate of about one every 2 years over the last 20 years, and incipient tube ruptures (tube failures usually identified with leak detection monitors just before rupture) have been occurring at the rate of about one per year. These ruptures have caused complex plant transients which have not always been easy for the reactor operators to control. Our analysis shows that if more than 15 tubes rupture during a main steam line break, the system response could lead to core melting. Although spontaneous and induced steam generator tube ruptures are small contributors to the total core damage frequency calculated in probabilistic risk assessments, they are risk significant because the radionuclides are likely to bypass the reactor containment building. The frequency of steam generator tube ruptures can be significantly reduced through appropriate and timely inspections and repairs or removal from service

  14. Waste Generation and Recycling

    OpenAIRE

    Ida Ferrara

    2008-01-01

    There are two serious failures that arise in the management of solid waste. The first relates to the existence of negative externalities in the individual decision-making over waste generation and disposal. When individuals decide on how much to consume and what to consume, they do not take into account how much waste they produce. Because the external costs of waste generation (such as air and water pollution) are ignored by individuals, more waste is produced and disposed of than is sociall...

  15. Wave Generation Theory

    DEFF Research Database (Denmark)

    Frigaard, Peter; Høgedal, Michael; Christensen, Morten

    The intention of this manual is to provide some formulas and techniques which can be used for generating waves in hydraulic laboratories. Both long crested waves (2-D waves) and short crested waves (3-D waves) are considered.......The intention of this manual is to provide some formulas and techniques which can be used for generating waves in hydraulic laboratories. Both long crested waves (2-D waves) and short crested waves (3-D waves) are considered....

  16. Dynamically Generated $\\Xi (1690)$

    CERN Document Server

    Sekihara, Takayasu

    2016-01-01

    We show that the $\\Xi (1690)$ resonance can be dynamically generated in the $s$-wave $\\bar{K} \\Sigma$-$\\bar{K} \\Lambda$-$\\pi \\Xi$-$\\eta \\Xi$ coupled-channels chiral unitary approach. In our model, the $\\Xi (1690)$ resonance appears near the $\\bar{K} \\Sigma$ threshold as a $\\bar{K} \\Sigma$ molecular state and the experimental data are reproduced well. We discuss properties of the dynamically generated $\\Xi (1690)$.

  17. Quad precision delay generator

    International Nuclear Information System (INIS)

    A Quad Precision Delay Generator delays a digital edge by a programmed amount of time, varying from nanoseconds to microseconds. The output of this generator has an amplitude of the order of tens of volts and rise time of the order of nanoseconds. This was specifically designed and developed to meet the stringent requirements of the plasma focus experiments. Plasma focus is a laboratory device for producing and studying nuclear fusion reactions in hot deuterium plasma. 3 figs

  18. Next Generation Relativistic Models

    OpenAIRE

    Furnstahl, R. J.

    2003-01-01

    The current generation of covariant mean-field models has had many successes in calculations of bulk observables for medium to heavy nuclei, but there remain many open questions. New challenges are confronted when trying to systematically extend these models to reliably address nuclear structure physics away from the line of stability. In this lecture, we discuss a framework for the next generation of relativistic models that can address these questions and challenges. We interpret nuclear me...

  19. Full scale biogas generator

    Energy Technology Data Exchange (ETDEWEB)

    1980-12-01

    In Israel, a generator of fuel gas from organic waste materials was recently inaugurated and it may be the world's largest generator. The plant, which has a design output of 500 litres of liquid fuel per day, is based on the anaerobic digestion of manure and other wastes from kibbutz cattle sheds. Laboratory tests indicate that up to sixty cubic feet of high quality methane can be obtained from each cubic foot of manure.

  20. Nuclear power generation device

    International Nuclear Information System (INIS)

    In a PWR type reactor, a free piston type stirling engine is disposed instead of a conventional steam generator and a turbine. Since the stirling engine does not cause radiation leakage in view of the structure, safety and reliability of the nuclear power generation are improved. Further, the thermal cycle, if it operates theoretically, is equivalent with a Carnot cycle having the highest thermodynamical heat efficiency, thereby enabling to obtain a high heat efficiency in an actual engine. (N.H.)

  1. Future generations in democracy

    DEFF Research Database (Denmark)

    Jensen, Karsten Klint

    2015-01-01

    This paper asks whether the genuine representation of future generations brings any added value that could not be achieved by institutions or procedures installed to supplement and support ordinary representative democracy. On this background, it reviews some arguments for genuine representation of...... future generations within current democracy. It is concluded that what really matters in terms of the democratic ideal is to ensure an impartial deliberation which takes the interests of all affected parties sufficiently into account....

  2. Fuel cell generator

    International Nuclear Information System (INIS)

    A high temperature solid electrolyte fuel cell generator comprising a housing means defining a plurality of chambers including a generator chamber and a combustion products chamber, a porous barrier separating the generator and combustion product chambers, a plurality of elongated annular fuel cells each having a closed end and an open end with the open ends disposed within the combustion product chamber, the cells extending from the open end through the porous barrier and into the generator chamber, a conduit for each cell, each conduit extending into a portion of each cell disposed within the generator chamber, each conduit having means for discharging a first gaseous reactant within each fuel cell, exhaust means for exhausting the combustion product chamber, manifolding means for supplying the first gaseous reactant to the conduits with the manifolding means disposed within the combustion product chamber between the porous barrier and the exhaust means and the manifolding means further comprising support and bypass means for providing support of the manifolding means within the housing while allowing combustion products from the first and a second gaseous reactant to flow past the manifolding means to the exhaust means, and means for flowing the second gaseous reactant into the generator chamber

  3. PDF Marksheet Generator

    Directory of Open Access Journals (Sweden)

    Srushti Shimpi

    2014-10-01

    Full Text Available The Marksheet Generator is flexible for generating progress mark sheet of students. This system is mainly based in the database technology and the credit based grading system (CBGS. The system is targeted to small enterprises, schools, colleges and universities. It can produce sophisticated ready-to-use mark sheet, which could be created and will be ready to print. The development of a marksheet and gadget sheet is focusing at describing tables with columns/rows and sub-column sub-rows, rules of data selection and summarizing for report, particular table or column/row, and formatting the report in destination document. The adjustable data interface will be popular data sources (SQL Server and report destinations (PDF file. Marksheet generation system can be used in universities to automate the distribution of digitally verifiable mark-sheets of students. The system accesses the students’ exam information from the university database and generates the gadget-sheet Gadget sheet keeps the track of student information in properly listed manner. The project aims at developing a marksheet generation system which can be used in universities to automate the distribution of digitally verifiable student result mark sheets. The system accesses the students’ results information from the institute student database and generates the mark sheets in Portable Document Format which is tamper proof which provides the authenticity of the document. Authenticity of the document can also be verified easily.

  4. Novel phosphatidylethanolamine derivatives accumulate in circulation in hyperlipidemic ApoE−/− mice and activate platelets via TLR2

    Science.gov (United States)

    Biswas, Sudipta; Xin, Liang; Panigrahi, Soumya; Zimman, Alejandro; Wang, Hua; Yakubenko, Valentin P.; Byzova, Tatiana V.; Salomon, Robert G.

    2016-01-01

    A prothrombotic state and increased platelet reactivity are common in dyslipidemia and oxidative stress. Lipid peroxidation, a major consequence of oxidative stress, generates highly reactive products, including hydroxy-ω-oxoalkenoic acids that modify autologous proteins generating biologically active derivatives. Phosphatidylethanolamine, the second most abundant eukaryotic phospholipid, can also be modified by hydroxy-ω-oxoalkenoic acids. However, the conditions leading to accumulation of such derivatives in circulation and their biological activities remain poorly understood. We now show that carboxyalkylpyrrole-phosphatidylethanolamine derivatives (CAP-PEs) are present in the plasma of hyperlipidemic ApoE−/− mice. CAP-PEs directly bind to TLR2 and induces platelet integrin αIIbβ3 activation and P-selectin expression in a Toll-like receptor 2 (TLR2)-dependent manner. Platelet activation by CAP-PEs includes assembly of TLR2/TLR1 receptor complex, induction of downstream signaling via MyD88/TIRAP, phosphorylation of IRAK4, and subsequent activation of tumor necrosis factor receptor–associated factor 6. This in turn activates the Src family kinases, spleen tyrosine kinase and PLCγ2, and platelet integrins. Murine intravital thrombosis studies demonstrated that CAP-PEs accelerate thrombosis in TLR2-dependent manner and that TLR2 contributes to accelerate thrombosis in mice in the settings of hyperlipidemia. Our study identified the novel end-products of lipid peroxidation, accumulating in circulation in hyperlipidemia and inducing platelet activation by promoting cross-talk between innate immunity and integrin activation signaling pathways. PMID:27015965

  5. Generation IV reactors: economics

    International Nuclear Information System (INIS)

    The operating nuclear reactors were built over a short period: no more than 10 years and today their average age rounds 18 years. EDF (French electricity company) plans to renew its reactor park over a far longer period : 30 years from 2020 to 2050. According to EDF this objective implies 3 constraints: 1) a service life of 50 to 60 years for a significant part of the present operating reactors, 2) to be ready to built a generation 3+ unit in 2020 which infers the third constraint: 3) to launch the construction of an EPR (European pressurized reactor) prototype as soon as possible in order to have it operating in 2010. In this scheme, generation 4 reactor will benefit the feedback experience of generation 3 and will take over in 2030. Economic analysis is an important tool that has been used by the generation 4 international forum to select the likely future reactor systems. This analysis is based on 4 independent criteria: the basic construction cost, the construction time, the operation and maintenance costs and the fuel cycle cost. This analysis leads to the evaluation of the global cost of electricity generation and of the total investment required for each of the reactor system. The former defines the economic competitiveness in a de-regulated energy market while the latter is linked to the financial risk taken by the investor. It appears, within the limits of the assumptions and models used, that generation 4 reactors will be characterized by a better competitiveness and an equivalent financial risk when compared with the previous generation. (A.C.)

  6. The Gel Generator option

    International Nuclear Information System (INIS)

    The development of a national policy for guaranteeing an ample supply of 99mTc to nuclear medicine, involves issues which go beyond the means by which radioactivation is achieved. Indeed, in such an exercise the pragmatic dictates of business and the sensitivities of politics must also be taken into account. Furthermore where a preference towards the nuclear reactor or the potential of cyclotrons is being questioned, the debate is incomplete if the only options that are considered are the fission-based 99Mo generator versus the direct cyclotron production of 99mTc. There is a third option (also neutron γ-based), an alternative to the fission 99Mo generator, which ought not be overlooked. The application of low specific activity (n,γ) 99Mo to a new type of generator, the Gel Generator, has been the focus of much research, particularly in Australia and more recently in China. After the initial concept had been established in the laboratory, the Australian researchers then undertook a comprehensive program of tests on the Gel Generator to assess its potential, either in the clinical laboratory or the centralised radiopharmacy, for supplying 99mTc suitable for nuclear medicine. The outcome of this program was a clear indication that the Gel Generator innovation had the capability to provide both technical and economic advantages to the nuclear medicine industry. These advantages are described. Since that time the Gel Generator has been selected for routine use in China where it now satisfies more than 30% of the 99mTc demand. (author)

  7. Design of Cryptographically Strong Generator By Transforming Linearly Generated Sequences

    Directory of Open Access Journals (Sweden)

    Dasgupta Dipankar

    2009-09-01

    Full Text Available Random numbers have been used extensively in many simulation applications like Monte Carlo Integration or computer modeling. But recently security applications have increased the need for strong(secure random number generation like automatic password generation, encryption algorithms, on-line gambling etc. Thus random number generation has become a challenging and an interesting task. Most classical random number generators, generate sequences that are either linear or predictable hence not suitable for cryptographic and security applications. Others generate sequences that even though they are secure they are not cryptographically strong and above all are slow in execution. Also recent advances in random number generation like the construction of Multiple Recursive Generator(MRG with large orders, Fast Multiple Recursive Generator( FMRG and DX(system of multiple recursive generators proposed by Deng and XU(2003 generators does not generate a strong random number sequences. Though MRGs have extremely long period of length with good empirical performance, its recurrence equation can be solved given a small set of its generated sequence, this implies that MRGs and FMRGs are not strong cryptographic generators. We propose an algorithm that will transform linear sequences generated by both classical LCG, MRGs, FMRGs and DX generators and make them cryptographically strong generators by hiding the entire sequence generated by the generators, thus it will be difficult for cryptanalyst to predict or infer the generator sequence if even the partial sequence or the parameters or knowledge of the algorithm used in the transformation of the generators are known.

  8. Fourth Generation Reactor Concepts

    International Nuclear Information System (INIS)

    Concerns over energy resources availability, climate changes and energy supply security suggest an important role for nuclear energy in future energy supplies. So far nuclear energy evolved through three generations and is still evolving into new generation that is now being extensively studied. Nuclear Power Plants are producing 16% of the world's electricity. Today the world is moving towards hydrogen economy. Nuclear technologies can provide energy to dissociate water into oxygen and hydrogen and to production of synthetic fuel from coal gasification. The introduction of breeder reactors would turn nuclear energy from depletable energy supply into an unlimited supply. From the early beginnings of nuclear energy in the 1940s to the present, three generations of nuclear power reactors have been developed: First generation reactors: introduced during the period 1950-1970. Second generation: includes commercial power reactors built during 1970-1990 (PWR, BWR, Candu, Russian RBMK and VVER). Third generation: started being deployed in the 1990s and is composed of Advanced LWR (ALWR), Advanced BWR (ABWR) and Passive AP600 to be deployed in 2010-2030. Future advances of the nuclear technology designs can broaden opportunities for use of nuclear energy. The fourth generation reactors are expected to be deployed by 2030 in time to replace ageing reactors built in the 1970s and 1980s. The new reactors are to be designed with a view of the following objectives: economic competitiveness, enhanced safety, minimal radioactive waste production, proliferation resistance. The Generation IV International Forum (GIF) was established in January 2000 to investigate innovative nuclear energy system concepts. GIF members include Argentina, Brazil, Canada, Euratom, France Japan, South Africa, South Korea, Switzerland, United Kingdom and United States with the IAEA and OECD's NEA as permanent observers. China and Russia are expected to join the GIF initiative. The following six systems

  9. Epigenetics and Future Generations.

    Science.gov (United States)

    Del Savio, Lorenzo; Loi, Michele; Stupka, Elia

    2015-10-01

    Recent evidence of intergenerational epigenetic programming of disease risk broadens the scope of public health preventive interventions to future generations, i.e. non existing people. Due to the transmission of epigenetic predispositions, lifestyles such as smoking or unhealthy diet might affect the health of populations across several generations. While public policy for the health of future generations can be justified through impersonal considerations, such as maximizing aggregate well-being, in this article we explore whether there are rights-based obligations supervening on intergenerational epigenetic programming despite the non-identity argument, which challenges this rationale in case of policies that affect the number and identity of future people. We propose that rights based obligations grounded in the interests of non-existing people might fall upon existing people when generations overlap. In particular, if environmental exposure in F0 (i.e. existing people) will affect the health of F2 (i.e. non-existing people) through epigenetic programming, then F1 (i.e. existing and overlapping with both F0 and F2) might face increased costs to address F2's condition in the future: this might generate obligations upon F0 from various distributive principles, such as the principle of equal opportunity for well being. PMID:25644664

  10. Magnetohydrodynamic power generation

    International Nuclear Information System (INIS)

    The paper describes research and development in the field of magnetohydrodynamic power generation technology, based on discussions held in the Joint IAEA/UNESCO International Liaison Group on MHD electrical power generation. Research and development programmes on open cycle, closed cycle plasma and liquid-metal MHD are described. Open cycle MHD has now entered the engineering development stage. The paper reviews the results of cycle analyses and economic and environmental evaluations: substantial agreement has been reached on the expected overall performance and necessary component specifications. The achievement in the Soviet Union on the U-25 MHD pilot plant in obtaining full rated electrical power of 20.4 MW is described, as well as long duration testing of the integrated operation of MHD components. Work in the United States on coal-fired MHD generators has shown that, with slagging of the walls, a run time of about one hundred hours at the current density and electric field of a commercial MHD generator has been achieved. Progress obtained in closed cycle plasma and liquid metal MHD is reviewed. Electrical power densities of up to 140 MWe/m3 and an enthalpy extraction as high as 24 per cent have been achieved in noble gas MHD generator experiments. (Auth.)

  11. MHD Generating system

    Science.gov (United States)

    Petrick, Michael; Pierson, Edward S.; Schreiner, Felix

    1980-01-01

    According to the present invention, coal combustion gas is the primary working fluid and copper or a copper alloy is the electrodynamic fluid in the MHD generator, thereby eliminating the heat exchangers between the combustor and the liquid-metal MHD working fluids, allowing the use of a conventional coalfired steam bottoming plant, and making the plant simpler, more efficient and cheaper. In operation, the gas and liquid are combined in a mixer and the resulting two-phase mixture enters the MHD generator. The MHD generator acts as a turbine and electric generator in one unit wherein the gas expands, drives the liquid across the magnetic field and thus generates electrical power. The gas and liquid are separated, and the available energy in the gas is recovered before the gas is exhausted to the atmosphere. Where the combustion gas contains sulfur, oxygen is bubbled through a side loop to remove sulfur therefrom as a concentrated stream of sulfur dioxide. The combustor is operated substoichiometrically to control the oxide level in the copper.

  12. Next-generation phylogenomics

    Directory of Open Access Journals (Sweden)

    Chan Cheong Xin

    2013-01-01

    Full Text Available Abstract Thanks to advances in next-generation technologies, genome sequences are now being generated at breadth (e.g. across environments and depth (thousands of closely related strains, individuals or samples unimaginable only a few years ago. Phylogenomics – the study of evolutionary relationships based on comparative analysis of genome-scale data – has so far been developed as industrial-scale molecular phylogenetics, proceeding in the two classical steps: multiple alignment of homologous sequences, followed by inference of a tree (or multiple trees. However, the algorithms typically employed for these steps scale poorly with number of sequences, such that for an increasing number of problems, high-quality phylogenomic analysis is (or soon will be computationally infeasible. Moreover, next-generation data are often incomplete and error-prone, and analysis may be further complicated by genome rearrangement, gene fusion and deletion, lateral genetic transfer, and transcript variation. Here we argue that next-generation data require next-generation phylogenomics, including so-called alignment-free approaches. Reviewers Reviewed by Mr Alexander Panchin (nominated by Dr Mikhail Gelfand, Dr Eugene Koonin and Prof Peter Gogarten. For the full reviews, please go to the Reviewers’ comments section.

  13. Hyperbolic graph generator

    Science.gov (United States)

    Aldecoa, Rodrigo; Orsini, Chiara; Krioukov, Dmitri

    2015-11-01

    Networks representing many complex systems in nature and society share some common structural properties like heterogeneous degree distributions and strong clustering. Recent research on network geometry has shown that those real networks can be adequately modeled as random geometric graphs in hyperbolic spaces. In this paper, we present a computer program to generate such graphs. Besides real-world-like networks, the program can generate random graphs from other well-known graph ensembles, such as the soft configuration model, random geometric graphs on a circle, or Erdős-Rényi random graphs. The simulations show a good match between the expected values of different network structural properties and the corresponding empirical values measured in generated graphs, confirming the accurate behavior of the program.

  14. Generator Coordinate Truncations

    CERN Document Server

    Hagino, K; Reinhard, P G

    2003-01-01

    We investigate the accuracy of several schemes to calculate ground-state correlation energies using the generator coordinate technique. Our test-bed for the study is the $sd$ interacting boson model, equivalent to a 6-level Lipkin-type model. We find that the simplified projection of a triaxial generator coordinate state using the $S_3$ subgroup of the rotation group is not very accurate in the parameter space of the Hamiltonian of interest. On the other hand, a full rotational projection of an axial generator coordinate state gives remarkable accuracy. We also discuss the validity of the simplified treatment using the extended Gaussian overlap approximation (top-GOA), and show that it works reasonably well when the number of boson is four or larger.

  15. Automated drawing generation system

    International Nuclear Information System (INIS)

    Since automated CAD drawing generation systems still require human intervention, improvements were focussed on an interactive processing section (data input and correcting operation) which necessitates a vast amount of work. As a result, human intervention was eliminated, the original objective of a computerized system. This is the first step taken towards complete automation. The effects of development and commercialization of the system are as described below. (1) The interactive processing time required for generating drawings was improved. It was determined that introduction of the CAD system has reduced the time required for generating drawings. (2) The difference in skills between workers preparing drawings has been eliminated and the quality of drawings has been made uniform. (3) The extent of knowledge and experience demanded of workers has been reduced. (author)

  16. Next generation workforce.

    Science.gov (United States)

    Swenson, Cathy

    2008-01-01

    The health care industry has become a very complex business. CQsts are rising and resources such as funding and human capital are diminishing. Human capital resources are about to reach true crisis proportions. The vital workforce we have counted on is expected to begin thinning as large numbers of Boomers retire. Not only does this deplete the workforce from a pure numbers perspective, but it also affects intellectual capital and institutional memory. Generational trends and characteristics have affected the workforce environment and will continue to do so as another generation continues to enter the workforce. Generation Y, also tagged Nexter, offers core values that can bring positive changes to the health care workforce. Technology continues to change at lightning speed. Embracing new technology and using it to refine the way we do business will help deliver success. Meaningful strategic plans are needed to change the model of business delivery and employee care in our future workforce. PMID:18389847

  17. Liquid metal steam generator

    International Nuclear Information System (INIS)

    A liquid metal heated steam generator is described which in the event of a tube failure quickly exhausts out of the steam generator the products of the reaction between the water and the liquid metal. The steam is generated in a plurality of bayonet tubes which are heated by liquid metal flowing over them between an inner cylinder and an outer cylinder. The inner cylinder extends above the level of liquid metal but below the main tube sheet. A central pipe extends down into the inner cylinder with a centrifugal separator between it and the inner cylinder at its lower end and an involute deflector plate above the separator so that the products of a reaction between the liquid metal and the water will be deflected downwardly by the deflector plate and through the separator so that the liquid metal will flow outwardly and away from the central pipe through which the steam and gaseous reaction products are exhausted. (U.S.)

  18. Learning to Generate Networks

    CERN Document Server

    Atwood, James

    2014-01-01

    The recent explosion in social network data has stimulated interest in probabilistic models of networks. Such models are appealing because they are empirically grounded; in contrast to more traditional network models, their parameters are estimated from data, and the models are evaluated on how well they represent the data. The exponential random graph model (ERGM, or, alternatively $p^*$) is currently the dominant framework for probabilistic network modeling. Despite their popularity, ERGMs suffer from a very serious flaw: near degeneracy. Briefly, an ERGM fit to a network or set of networks often ends up generating networks that look nothing at all like the training data. It is deeply troubling that the most likely model will generate instances that look nothing like data, and this calls the validity of models into question. In this work, we seek to address the general problem of learning to generate networks that do look like data. This is a large, challenging problem. To gain an understanding, we decompos...

  19. The Compton generator revisited

    International Nuclear Information System (INIS)

    The Compton generator, introduced in 1913 by the US physicist A H Compton as a relatively simple device to detect the Earth's rotation with respect to the distant stars, is analyzed and discussed in a general perspective. The paper introduces a generalized definition of the generator, emphasizing the special features of the original apparatus, and provides a suggestive interpretation of the way the device works. To this end, an intriguing electromagnetic analogy is developed, which turns out to be particularly useful in simplifying the calculations. Besides the more extensive description of the Compton generator in itself, the combined use of concepts and methods coming from different fields of physics, such as particle dynamics in moving references frames, continuum mechanics and electromagnetism, may be of interest to both teachers and graduate students. (paper)

  20. Generation Y Perspectives

    Science.gov (United States)

    Fitzpatrick, Garret; Painting, Kristen; Barrera, Aaron; Skytland, Nick

    2008-01-01

    Are you familiar with the famed Generation Y, or "Gen Yers?" Generation Y is projected to be 47 percent of the workforce by 2014. They were born roughly between 1977 and 2000, but that is definitely not their only defining factor. But who is this group, and what do they have to do with the future of the space program and the Johnson Space Center (JSC)? During 2007, a group of Gen Yers at JSC participated on a committee to address the NASA Headquarters strategic communications plan. Fitzpatrick, along with his co-authors, created a presentation to share the Gen Yers' perspective on their generation in conjunction with the strategic communications strategy released. This knowledge capture (KC) event is that presentation.

  1. Pattern Based Graph Generator

    CERN Document Server

    Shuai, Hong-Han; Yu, Philip S; Shen, Chih-Ya; Chen, Ming-Syan

    2013-01-01

    The importance of graph mining has been widely recognized thanks to a large variety of applications in many areas, while real datasets always play important roles to examine the solution quality and efficiency of a graph mining algorithm. Nevertheless, the size of a real dataset is usually fixed and constrained according to the available resources, such as the efforts to crawl an on-line social network. In this case, employing a synthetic graph generator is a possible way to generate a massive graph (e.g., billions nodes) for evaluating the scalability of an algorithm, and current popular statistical graph generators are properly designed to maintain statistical metrics such as total node degree, degree distribution, diameter, and clustering coefficient of the original social graphs. Nevertheless, in addition to the above metrics, recent studies on graph mining point out that graph frequent patterns are also important to provide useful implications for the corresponding social networking applications, but thi...

  2. Loser Generated Content

    DEFF Research Database (Denmark)

    Petersen, Søren Mørk

    2008-01-01

    that the Internet functions as a double–edged sword; the infrastructure does foster democracy, participation, joy, creativity and sometimes creates zones of piracy. But, at the same time, it has become evident how this same infrastructure also enables companies easily to piggyback on user generated......In this article [ 1 ] some of the critical aspects of Web 2.0 are mapped in relation to labor and the production of user generated content. For many years the Internet was considered an apt technology for subversion of capitalism by the Italian post–Marxists. What we have witnessed, however, is...

  3. Three Generations Travel

    OpenAIRE

    Florya, Yulia

    2014-01-01

    Tourism plays a magnificent role nowadays in people’s life. Now when there are fewer borders and more oppor-tunities to travel, people want to see and explore the world by themselves, together with their families and rela-tives. The thesis focuses on activities for three generation extended family travelers who are staying in Saimaa Holi-day Oravi cottages. The overall purpose is providing real activities for three generation travelers. The objective was to create brand-new activities, to...

  4. Next Generation Networks

    Directory of Open Access Journals (Sweden)

    Ladislav Schwartz

    2006-01-01

    Full Text Available Two network types had been existing in Slovakia by the end of the year 2004 – public switched telephone network – PSTN and packet switched data network – DCN. The other network, known as the next generation network – NGN, has been put into operation since the beginning of the year 2005. The role of the next generation network is to merge the both previous network types into one unified complex network with the full centralised control, based on routing and packet switching. The T-Com company (previous Slovak Telecom was the first who did it.

  5. Choice probability generating functions

    DEFF Research Database (Denmark)

    Fosgerau, Mogens; McFadden, Daniel; Bierlaire, Michel

    2010-01-01

    This paper establishes that every random utility discrete choice model (RUM) has a representation that can be characterized by a choice-probability generating function (CPGF) with specific properties, and that every function with these specific properties is consistent with a RUM. The choice...... probabilities from the RUM are obtained from the gradient of the CPGF. Mixtures of RUM are characterized by logarithmic mixtures of their associated CPGF. The paper relates CPGF to multivariate extreme value distributions, and reviews and extends methods for constructing generating functions for applications...

  6. Wind electric power generation

    International Nuclear Information System (INIS)

    The monthly statistics of wind electric power generation in Denmark are compiled from information given by the owners of private wind turbines. For each wind turbine the name of the site and of the type of turbine is given, and the power generation data are given for the month in question together with the total production in 1988 and 1989. Also the data of operation start are given. On the map of Denmark the sites of the wind turbines are marked. The statistics for December 1994 comprise 2328 wind turbines

  7. Nonlinear waveform generation.

    Science.gov (United States)

    Goldstein, L J; Rypins, E B

    1990-01-01

    We developed three analog logic SPICE (Simulation Program with Integrated Circuit Emphasis, developed at the University of California, Berkeley, CA) subcircuits, a voltage comparator and a nonlinear waveform generator to compliment the previously derived functions (Goldstein and Rypins, Comput. Methods Programs Biomed. 29 (1989) 161-172) that simplify modeling of physiologic systems. The logic elements are the 'AND', 'OR' and 'NOT' Boolean functions. In addition, we derived a voltage comparator for use in our composite waveform generator. All the circuits are analog so they can be incorporated into existing analog circuits while performing digital functions. PMID:2364683

  8. Electrogasdynamic Power Generation

    International Nuclear Information System (INIS)

    EGD power generation is one of many so-called direct energy conversion methods being considered for application to large-scale power generation. A typical cycle would consist of the following: Air and fuel are burned at relatively high pressure (120-450 lb/in2) in a combustion chamber. The combustion gas is then introduced into tubes made of a dielectric material (ceramic with high resistivity). At the entrance of these tubes, the gas is partially ionized by a corona discharge. The tubes are provided with an attractor electrode near the entrance and a collector electrode near the exit. An electric field in the tube is established by virtue of the external resistance in the connection between attractor and collector electrodes. This field offers resistance to the flow of gas seeded with ions. In the process of overcoming this resistance, kinetic energy of the gas stream is used. As the ions are pushed downstream they are collected on the collector electrode where they build up a high charge. In many ways this EGD process is like a Van de Graaff generator with the gas stream taking the place of the mechanically driven belt used in Van de Graaff machines. The great advantage of EGD power generation over MHD is the fact that high electrical conductivity of the gas stream is not necessary for EGD. For this reason the EGD process can be carried out at temperatures which are well within the limits of today’s technology. This same reason provides a second advantage; it is not necessary to limit the total amount of power generated in the direct conversion section. In MHD schemes, the conductivity of the gas is so low at temperatures below 3600°F (∼1980°C) that subsequent extraction of power from the gas stream has to be accomplished by conventional steam generation. This has the effect of degrading the overall efficiency of the cycle. In EGD systems, work can be extracted directly from the gas stream down to near atmospheric temperatures. High thermal efficiencies are

  9. The Generation of Fullerenes

    OpenAIRE

    Brinkmann, Gunnar; Goedgebeur, Jan; McKay, Brendan D.

    2012-01-01

    We describe an efficient new algorithm for the generation of fullerenes. Our implementation of this algorithm is more than 3.5 times faster than the previously fastest generator for fullerenes -- fullgen -- and the first program since fullgen to be useful for more than 100 vertices. We also note a programming error in fullgen that caused problems for 136 or more vertices. We tabulate the numbers of fullerenes and IPR fullerenes up to 400 vertices. We also check up to 316 vertices a conjecture...

  10. Seismic wave generator

    International Nuclear Information System (INIS)

    This invention concerns a device for simulating earth tremors. This device includes a seismic wave generator formed of a cylinder, one end of which is closed by one of the walls of a cell containing a soil, the other end being closed by a wall on which are fixed pyrotechnic devices generating shock waves inside the cylinder. These waves are transmitted from the cylinder to the cell through openings made in the cell wall. This device also includes a mechanical device acting as low-pass filter, located inside the cylinder and close to the cell wall

  11. Generating a scalar logic

    DEFF Research Database (Denmark)

    Ramsgaard Thomsen, Mette; Tamke, Martin

    2011-01-01

    This paper presents the design project "it's a SMALL world", an exhibition design developed for the Danish Design Centre in 2009. The project investigates the making of a generative design environment by which multiple design parameters as from program, site or the subsequent digital fabrication...... of a generative design approach, that can adapt through recursion gradually to local requirements, with explicit definitions. The project showcases with its new developed manufacturing system for nonstandard element how customized digital design and production tools allow for a novel nearness to...

  12. ColloInputGenerator

    DEFF Research Database (Denmark)

    2013-01-01

    it as input for basic collexeme collostructional analysis (Stefanowitsch & Gries 2003) in Gries' (2007) program. ColloInputGenerator is, in its current state, based on programming commands introduced in Gries (2009). Projected updates: Generation of complete work-ready frequency lists.......This is a very simple program to help you put together input files for use in Gries' (2007) R-based collostruction analysis program. It basically puts together a text file with a frequency list of lexemes in the construction and inserts a column where you can add the corpus frequencies. It requires...

  13. Hacking the next generation

    CERN Document Server

    Dhanjani, Nitesh; Hardin, Brett

    2009-01-01

    With the advent of rich Internet applications, the explosion of social media, and the increased use of powerful cloud computing infrastructures, a new generation of attackers has added cunning new techniques to its arsenal. For anyone involved in defending an application or a network of systems, Hacking: The Next Generation is one of the few books to identify a variety of emerging attack vectors. You'll not only find valuable information on new hacks that attempt to exploit technical flaws, you'll also learn how attackers take advantage of individuals via social networking sites, and abuse

  14. Transformer generated magnetic fields

    International Nuclear Information System (INIS)

    Magnetic fields produced by both small and large apparatus are being investigated for their possible relation to human health effects. A number of studies have been done in characterizing the magnetic field generated by transmission lines, household wiring and appliances. Two other major sources of magnetic fields are motors and transformers. The magnetic field generated by power transformers has not been studied extensively. The purpose of this paper is to experimentally quantify the magnetic field of a power transformer and compare it with calculated results obtained using one of the numerical techniques

  15. Patricia steam generator tests

    International Nuclear Information System (INIS)

    The Patricia GV program is a joint program of CEA, French utilities, and FRAMATOME. It aims at a better knowledge of the pressurized water reactor steam generator behavior under small break loss of coolant accident conditions. It has two parts: Patricia GVl deals with the primary side of the steam generator and is presently completed. Patricia GV2 deals with the secondary side dry-out phenomenon and is still in progress. Objectives, test facilities, test procedures, and results of the program are discussed

  16. Third Generation Coaching

    DEFF Research Database (Denmark)

    Stelter, Reinhard

    2016-01-01

    Third Generation Coaching entfaltet ein neues Universum für Coaching und Coaching-Psychologie auf der Grundlage veränderter Gesellschaftsbedingungen. Wir leben in hyperkomplexen sozialen und ökonomischen Kontexten. Coaching muss sich deshalb zu einer Dialogform weiterentwickeln, die dem Einzelnen...

  17. Third Generation Coaching

    DEFF Research Database (Denmark)

    Stelter, Reinhard

    2016-01-01

    German abstract: Auf der Grundlage aktueller Sozialforschung, neuer Lerntheorien und Diskurse der Personalführung entfaltet sich ein neues Verständnis von Coaching und Coaching-Psychologie. In der dritten Generation wird Coaching aus gesellschaftlicher Perspektive betrachtet. Wenn sich die...

  18. JMLUnit: The Next Generation

    Science.gov (United States)

    Zimmerman, Daniel M.; Nagmoti, Rinkesh

    Designing unit test suites for object-oriented systems is a painstaking, repetitive, and error-prone task, and significant research has been devoted to the automatic generation of test suites. One method for generating unit tests is to use formal class and method specifications as test oracles and automatically run them with developer-provided data values; for Java code with formal specifications written in the Java Modeling Language, this method is embodied in the JMLUnit tool and the JUnit testing framework on which it is based. While JMLUnit can provide reasonable test coverage when used by a skilled developer, it suffers from several shortcomings including excessive memory utilization during testing and the need to manually write significant amounts of code to generate non-primitive test data objects. In this paper we describe JMLUnitNG, a TestNG-based successor to JMLUnit that can automatically generate and execute millions of tests, using supplied test data of only primitive types, without consuming excessive amounts of memory. We also present a comparison of test coverage between JMLUnitNG and the original JMLUnit.

  19. Tredje generations coaching

    DEFF Research Database (Denmark)

    Stelter, Reinhard

    2012-01-01

    ”Tredje generations coaching” udfolder et nyt univers for coaching og coachingpsykologi gennem en bearbejdelse af aktuel samfundsforskning, nye læringsteorier og diskurser om det personlige lederskab. ”Tredje generations coaching” er funderet på en samfundsmæssig forståelse af coaching. Coaching er...... blevet så betydningsfuld, fordi samfundet opleves som uoverskueligt og hyperkomplekst. Viden skal nu udformes og anvendes i specifikke kontekster og situationer, og både i privatliv og i det offentlige rum skal vi lære at forhandle os til rette. Coaching kan hjælpe os til at skabe ny viden og mestre...... sociale forhandlinger. Coaching er dermed en slags fødselshjælp til nye refleksioner og perspektiver, en hjælp til selvhjælp og en støtte til ens egen selvdannelsesproces. ”Tredje generations coaching” fremhæver coach og coachee i deres narrativ-samskabende partnerskab. Til forskel fra første generations...

  20. SECOND GENERATION MODEL

    Science.gov (United States)

    One of the environmental and economic models that the U.S. EPA uses to assess climate change policies is the Second Generation Model (SGM). SGM is a 13 region, 24 sector computable general equilibrium (CGE) model of the world that can be used to estimate the domestic and intern...

  1. Variable speed generators

    CERN Document Server

    Boldea, Ion

    2005-01-01

    With the deregulation of electrical energy production and distribution, says Boldea (Polytechnical Institute, Timisoara, Romania) producers are looking for ways to tailor their electricity for different markets. Variable-speed electric generators are serving that purpose, up to the 400 megavolt ampere unit size, in Japan since 1996 and Germany sinc

  2. Next Generation Inverter

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, Zilai [General Motors LLC, Detroit, MI (United States); Gough, Charles [General Motors LLC, Detroit, MI (United States)

    2016-04-22

    The goal of this Cooperative Agreement was the development of a Next Generation Inverter for General Motors’ electrified vehicles, including battery electric vehicles, range extended electric vehicles, plug-in hybrid electric vehicles and hybrid electric vehicles. The inverter is a critical electronics component that converts battery power (DC) to and from the electric power for the motor (AC).

  3. MHD power generation system

    International Nuclear Information System (INIS)

    The present invention provides a power generation system of high energy efficiency comprising, in combination, a FBR type reactor using liquid metal as coolants and a liquid MHD power generator. That is, a preheater is disposed to the downstream of a condenser in a turbine power generation system and a heat exchanger is disposed to the upstream of a mixer in a gas system. Then, a high temperature gas from a separator is introduced into the preheater and sufficiently lowered for the temperature and then pressurized in a pump. Then, the pressurized gas is passed through the heat exchanger and heated. Thus, heat energy possessed in the high temperature gas from the separator is used for preheating the hydraulic fluid of the turbine power generation system through the preheater. Accordingly, the heat energy can effectively be utilized instead of being discharged out of the system as usual. Further, when the gas deprived of heat energy and cooled to a lower temperature is pressurized by the pump and heated by the heat exchanger, the heat energy is received from liquid metals of FBR type reactor and, accordingly, the energy efficiency can be improved as compared with the conventional re-heating system. (I.S.)

  4. Generating innovation opportunities:

    DEFF Research Database (Denmark)

    Kallio, Anne; Bergenholtz, Carsten

    This study examines how a company can generate innovation opportunities by exploring and absorbing customer knowledge. The exploration can be performed via an in-depth or broad search for resources beyond organisational boundaries. Salespeople are an essential channel for an in-depth search in...

  5. Dynamical generation of flavour

    Indian Academy of Sciences (India)

    Charanjit Kaur Khosa

    2016-02-01

    We propose the generation of Standard Model fermion hierarchy by the extension of renormalizable SO(10) GUT with O(Ng) family gauge symmetry. In this scenario, Higgs representations of SO(10) also carry family indices and are called Yukawons. Vacuum expectation values of these Yukawon fields break GUT and family symmetry and generate MSSM Yukawa couplings dynamically. We have demonstrated this idea using $10 \\oplus 210 \\oplus 126 \\oplus \\overline{126}$ Higgs irrep, ignoring the contribution of 120-plet which is, however, required for complete fitting of fermion mass-mixing data. The effective MSSM matter fermion couplings to the light Higgs pair are determined by the null eigenvectors of the MSSM-type Higgs doublet superfield mass matrix $\\mathcal{H}$. A consistency condition on the doublet ([1, 2,±1]) mass matrix (Det($\\mathcal{H}$) = 0) is required to keep one pair of Higgs doublets light in the effective MSSM. We show that the Yukawa structure generated by null eigenvectors of $\\mathcal{H}$ are of generic kind required by the MSSM. A hidden sector with a pair of (Sab; ab) fields breaks supersymmetry and facilitates DO(Ng) = 0. SUSY breaking is communicated via supergravity. In this scenario, matter fermion Yukawa couplings are reduced from 15 to just 3 parameters in MSGUT with three generations.

  6. Automatic Dance Lesson Generation

    Science.gov (United States)

    Yang, Yang; Leung, H.; Yue, Lihua; Deng, LiQun

    2012-01-01

    In this paper, an automatic lesson generation system is presented which is suitable in a learning-by-mimicking scenario where the learning objects can be represented as multiattribute time series data. The dance is used as an example in this paper to illustrate the idea. Given a dance motion sequence as the input, the proposed lesson generation…

  7. CONFIGURATION GENERATOR MODEL

    International Nuclear Information System (INIS)

    ''The Disposal Criticality Analysis Methodology Topical Report'' prescribes an approach to the methodology for performing postclosure criticality analyses within the monitored geologic repository at Yucca Mountain, Nevada. An essential component of the methodology is the ''Configuration Generator Model for In-Package Criticality'' that provides a tool to evaluate the probabilities of degraded configurations achieving a critical state. The configuration generator model is a risk-informed, performance-based process for evaluating the criticality potential of degraded configurations in the monitored geologic repository. The method uses event tree methods to define configuration classes derived from criticality scenarios and to identify configuration class characteristics (parameters, ranges, etc.). The probabilities of achieving the various configuration classes are derived in part from probability density functions for degradation parameters. The NRC has issued ''Safety Evaluation Report for Disposal Criticality Analysis Methodology Topical Report, Revision 0''. That report contained 28 open items that required resolution through additional documentation. Of the 28 open items, numbers 5, 6, 9, 10, 18, and 19 were concerned with a previously proposed software approach to the configuration generator methodology and, in particular, the keff regression analysis associated with the methodology. However, the use of a keff regression analysis is not part of the current configuration generator methodology and, thus, the referenced open items are no longer considered applicable and will not be further addressed

  8. Generative Models of Disfluency

    Science.gov (United States)

    Miller, Timothy A.

    2010-01-01

    This thesis describes a generative model for representing disfluent phenomena in human speech. This model makes use of observed syntactic structure present in disfluent speech, and uses a right-corner transform on syntax trees to model this structure in a very natural way. Specifically, the phenomenon of speech repair is modeled by explicitly…

  9. Laser generating metallic components

    Science.gov (United States)

    McLean, Marc A.; Shannon, G. J.; Steen, William M.

    1997-04-01

    Recent developments in rapid prototyping have led to the concept of laser generating, the first additive manufacturing technology. This paper presents an innovative process of depositing multi-layer tracks, by fusing successive powder tracks, to generate three dimensional components, thereby offering an alternative to casting for small metal component manufacture. A coaxial nozzle assembly has been designed and manufactured enabling consistent omni-directional multi-layer deposition. In conjunction with this the software route from a CAD drawing to machine code generation has been established. The part is manufactured on a six axes machining center incorporating a 1.8 kW carbon-dioxide laser, providing an integrated opto-mechanical workstation. The part build-up program is controlled by a P150 host computer, linked directly to the DNC machining center. The direct manufacturing route is shown, including initial examples of simple objects (primitives -- cube, cylinder, cone) leading to more complex turbine blade generation, incorporating build-up techniques and the associated mechanical properties.

  10. Generating Primes Using Partitions

    OpenAIRE

    Pittu, Ganesh Reddy

    2015-01-01

    This paper presents a new technique of generating large prime numbers using a smaller one by employing Goldbach partitions. Experiments are presented showing how this method produces candidate prime numbers that are subsequently tested using either Miller Rabin or AKS primality tests.

  11. Temporaliteten i en generation

    DEFF Research Database (Denmark)

    Andrade, Stefan Bastholm

    2011-01-01

    samfundet. Som empirisk eksempel benyttes et datasæt fra YODA projektet om unges forbrug af alkohol. På baggrund af sekvensanalysen demonstrerer jeg, hvorledes en generation af unge har forskellige tidsopfattelser af ugens syv dage i forbindelse med alkoholforbrug. Resultatet viser fem forskellige tidslige...

  12. CIT: Neutron Generator Systems

    International Nuclear Information System (INIS)

    Neutron generator systems, including neutron tubes: (1) Controls - HS: 8543.19, 8479.89, 9015.80, 9027.80 - NSG DUL: 6.A.5. - EU: 3A231; (2) Nuclear uses - initiate nuclear fission chain reaction in a nuclear explosive device - to analyze the state of reactors or other critical assemblies; and (3) Other uses - Downhole oil well logging - plutonium and effluent flow analysis - examination of sealed packages (to detect explosives, etc.) - detection or assay of fissionable materials - neutron radiography, physics research, radiation therapy for cancer. Neutron generator systems include a neutron tube, control unit, and a high-voltage power supply. The neutron tube is the fundamental element. Neutron generator tubes are usually cylindrical. The tube housing can be glass, ceramic, or metal, with sizes between 3.8-6.4 cm in diameter and 10-30 cm in length. Neutron generator assemblies contain the neutron tube, magnet, and high-voltage transformer. It may be enclosed in a glass, ceramic, or steel cylinder 10-25 cm in diameter, 43-61 cm in length. Assemblies are typically filled with a dielectric gas or liquid to insulate and cool the high-voltage circuitry.

  13. System-generated EMP

    International Nuclear Information System (INIS)

    The state of the art of system-generated electromagnetic pulse (SGEMP) is reviewed with particular emphasis on the empirical laws of photoelectron emission current and the analytical and numerical techniques employed for the calculation of currents and charges induced on the surface of a system such as a satellite

  14. Energy generation in stars

    OpenAIRE

    Vasiliev, B. V.

    2001-01-01

    It is a current opinion that thermonuclear fusion is the main source of the star activity. It is shown below that this source is not unique. There is another electrostatic mechanism of the energy generation which accompanies thermonuclear fusion. Probably, this approach can solve the solar neutrino problem.

  15. Generating "Random" Integers

    Science.gov (United States)

    Griffiths, Martin

    2011-01-01

    One of the author's undergraduate students recently asked him whether it was possible to generate a random positive integer. After some thought, the author realised that there were plenty of interesting mathematical ideas inherent in her question. So much so in fact, that the author decided to organise a workshop, open both to undergraduates and…

  16. High Voltage Seismic Generator

    Science.gov (United States)

    Bogacz, Adrian; Pala, Damian; Knafel, Marcin

    2015-04-01

    This contribution describes the preliminary result of annual cooperation of three student research groups from AGH UST in Krakow, Poland. The aim of this cooperation was to develop and construct a high voltage seismic wave generator. Constructed device uses a high-energy electrical discharge to generate seismic wave in ground. This type of device can be applied in several different methods of seismic measurement, but because of its limited power it is mainly dedicated for engineering geophysics. The source operates on a basic physical principles. The energy is stored in capacitor bank, which is charged by two stage low to high voltage converter. Stored energy is then released in very short time through high voltage thyristor in spark gap. The whole appliance is powered from li-ion battery and controlled by ATmega microcontroller. It is possible to construct larger and more powerful device. In this contribution the structure of device with technical specifications is resented. As a part of the investigation the prototype was built and series of experiments conducted. System parameter was measured, on this basis specification of elements for the final device were chosen. First stage of the project was successful. It was possible to efficiently generate seismic waves with constructed device. Then the field test was conducted. Spark gap wasplaced in shallowborehole(0.5 m) filled with salt water. Geophones were placed on the ground in straight line. The comparison of signal registered with hammer source and sparker source was made. The results of the test measurements are presented and discussed. Analysis of the collected data shows that characteristic of generated seismic signal is very promising, thus confirms possibility of practical application of the new high voltage generator. The biggest advantage of presented device after signal characteristics is its size which is 0.5 x 0.25 x 0.2 m and weight approximately 7 kg. This features with small li-ion battery makes

  17. GASIFICATION FOR DISTRIBUTED GENERATION

    Energy Technology Data Exchange (ETDEWEB)

    Ronald C. Timpe; Michael D. Mann; Darren D. Schmidt

    2000-05-01

    A recent emphasis in gasification technology development has been directed toward reduced-scale gasifier systems for distributed generation at remote sites. The domestic distributed power generation market over the next decade is expected to be 5-6 gigawatts per year. The global increase is expected at 20 gigawatts over the next decade. The economics of gasification for distributed power generation are significantly improved when fuel transport is minimized. Until recently, gasification technology has been synonymous with coal conversion. Presently, however, interest centers on providing clean-burning fuel to remote sites that are not necessarily near coal supplies but have sufficient alternative carbonaceous material to feed a small gasifier. Gasifiers up to 50 MW are of current interest, with emphasis on those of 5-MW generating capacity. Internal combustion engines offer a more robust system for utilizing the fuel gas, while fuel cells and microturbines offer higher electric conversion efficiencies. The initial focus of this multiyear effort was on internal combustion engines and microturbines as more realistic near-term options for distributed generation. In this project, we studied emerging gasification technologies that can provide gas from regionally available feedstock as fuel to power generators under 30 MW in a distributed generation setting. Larger-scale gasification, primarily coal-fed, has been used commercially for more than 50 years to produce clean synthesis gas for the refining, chemical, and power industries. Commercial-scale gasification activities are under way at 113 sites in 22 countries in North and South America, Europe, Asia, Africa, and Australia, according to the Gasification Technologies Council. Gasification studies were carried out on alfalfa, black liquor (a high-sodium waste from the pulp industry), cow manure, and willow on the laboratory scale and on alfalfa, black liquor, and willow on the bench scale. Initial parametric tests

  18. Short pulse neutron generator

    Energy Technology Data Exchange (ETDEWEB)

    Elizondo-Decanini, Juan M.

    2016-08-02

    Short pulse neutron generators are described herein. In a general embodiment, the short pulse neutron generator includes a Blumlein structure. The Blumlein structure includes a first conductive plate, a second conductive plate, a third conductive plate, at least one of an inductor or a resistor, a switch, and a dielectric material. The first conductive plate is positioned relative to the second conductive plate such that a gap separates these plates. A vacuum chamber is positioned in the gap, and an ion source is positioned to emit ions in the vacuum chamber. The third conductive plate is electrically grounded, and the switch is operable to electrically connect and disconnect the second conductive plate and the third conductive plate. The at least one of the resistor or the inductor is coupled to the first conductive plate and the second conductive plate.

  19. The intense neutron generator

    Energy Technology Data Exchange (ETDEWEB)

    Lewis, W.B

    1966-07-01

    The presentation discusses both the economic and research contexts that would be served by producing neutrons in gram quantities at high intensities by electrical means without uranium-235. The revenue from producing radioisotopes is attractive. The array of techniques introduced by the multipurpose 65 megawatt Intense Neutron Generator project includes liquid metal cooling, superconducting magnets for beam bending and focussing, super-conductors for low-loss high-power radiofrequency systems, efficient devices for producing radiofrequency power, plasma physics developments for producing and accelerating hydrogen, ions at high intensity that are still far out from established practice, a multimegawatt high voltage D.C. generating machine that could have several applications. The research fields served relate principally to materials science through neutron-phonon and other quantum interactions as well as through neutron diffraction. Nuclear physics is served through {mu}-, {pi}- and K-meson production. Isotope production enters many fields of applied research. (author)

  20. Magneto hydrodynamic generators

    International Nuclear Information System (INIS)

    Fundamentally MHD generators are not much different from the conventional generators. Faraday's fundamental laws of electromagnetic induction, i.e., when a conductor and magnetic field move with respect to each other an e.m.f. is induced in the conductor and if the circuit is complete an electric current will pass through it. It consists of a pipe through which a gas at a very high temperature and pressure passes from left to right. The field coil shown provides magnetic field in direction perpendicular to the direction of the motion of the gas-An e.m.f. is induced in a third mutually perpendicular direction. The reason of the gas, being used at high temperature is that it becomes conductive. To increase the conductivity further the gas can be seeded i.e., a small amount of vaporized metal such as potassium is added

  1. Low energy ion generator

    International Nuclear Information System (INIS)

    In order to investigate the modification of polymer surface by ion bombardment, low energy ion generator has been constructed. In this report were described system design construction, generator components such as power system and evacuation system, the results of performance test. A maximum beam intensity of Kr+ was 1.6 mA at 35 kV on a Ti-target. From the preliminary experimental results of Kr+ irradiation, the coloration (carbonization) of the polymer surface, i.e. the increase of optical density, was observed. The relationship between the optical density change of irradiated polymer film and Kr+ beam currents as measured by Faraday Cup will provide a convenient method to estimate absorbed ion energy in the film. (author)

  2. Parallel Polarization State Generation.

    Science.gov (United States)

    She, Alan; Capasso, Federico

    2016-01-01

    The control of polarization, an essential property of light, is of wide scientific and technological interest. The general problem of generating arbitrary time-varying states of polarization (SOP) has always been mathematically formulated by a series of linear transformations, i.e. a product of matrices, imposing a serial architecture. Here we show a parallel architecture described by a sum of matrices. The theory is experimentally demonstrated by modulating spatially-separated polarization components of a laser using a digital micromirror device that are subsequently beam combined. This method greatly expands the parameter space for engineering devices that control polarization. Consequently, performance characteristics, such as speed, stability, and spectral range, are entirely dictated by the technologies of optical intensity modulation, including absorption, reflection, emission, and scattering. This opens up important prospects for polarization state generation (PSG) with unique performance characteristics with applications in spectroscopic ellipsometry, spectropolarimetry, communications, imaging, and security. PMID:27184813

  3. Parallel Polarization State Generation

    Science.gov (United States)

    She, Alan; Capasso, Federico

    2016-05-01

    The control of polarization, an essential property of light, is of wide scientific and technological interest. The general problem of generating arbitrary time-varying states of polarization (SOP) has always been mathematically formulated by a series of linear transformations, i.e. a product of matrices, imposing a serial architecture. Here we show a parallel architecture described by a sum of matrices. The theory is experimentally demonstrated by modulating spatially-separated polarization components of a laser using a digital micromirror device that are subsequently beam combined. This method greatly expands the parameter space for engineering devices that control polarization. Consequently, performance characteristics, such as speed, stability, and spectral range, are entirely dictated by the technologies of optical intensity modulation, including absorption, reflection, emission, and scattering. This opens up important prospects for polarization state generation (PSG) with unique performance characteristics with applications in spectroscopic ellipsometry, spectropolarimetry, communications, imaging, and security.

  4. Parallel Polarization State Generation

    CERN Document Server

    She, Alan

    2016-01-01

    The control of polarization, an essential property of light, is of wide scientific and technological interest. The general problem of generating arbitrary time-varying states of polarization (SOP) has always been mathematically formulated by a series of linear transformations, i.e. a product of matrices, imposing a serial architecture. Here we show a parallel architecture described by a sum of matrices. The theory is experimentally demonstrated by modulating spatially-separated polarization components of a laser using a digital micromirror device that are subsequently beam combined. This method greatly expands the parameter space for engineering devices that control polarization. Consequently, performance characteristics, such as speed, stability, and spectral range, are entirely dictated by the technologies of optical intensity modulation, including absorption, reflection, emission, and scattering. This opens up important prospects for polarization state generation (PSG) with unique performance characteristi...

  5. Second harmonic generation imaging

    CERN Document Server

    2013-01-01

    Second-harmonic generation (SHG) microscopy has shown great promise for imaging live cells and tissues, with applications in basic science, medical research, and tissue engineering. Second Harmonic Generation Imaging offers a complete guide to this optical modality, from basic principles, instrumentation, methods, and image analysis to biomedical applications. The book features contributions by experts in second-harmonic imaging, including many pioneering researchers in the field. Written for researchers at all levels, it takes an in-depth look at the current state of the art and possibilities of SHG microscopy. Organized into three sections, the book: Provides an introduction to the physics of the process, step-by-step instructions on how to build an SHG microscope, and comparisons with related imaging techniques Gives an overview of the capabilities of SHG microscopy for imaging tissues and cells—including cell membranes, muscle, collagen in tissues, and microtubules in live cells—by summarizing experi...

  6. Extractive 90Y generator

    International Nuclear Information System (INIS)

    The generator for 90Y production is made up of two units - an extractive unit and a unit for deep purification. Contrary to the well-known methods of 90Y separation two mineral acids are used in the developed technology. The solutions of nitric acid are used for preliminary separation of 90Y and the solutions of hydrochloric acid are used for the deep purification of 90Y from 90Sr and stripping. The optimum conditions for carrying out this technology were found. The following results are reported: the carry-over of the stationary phase is excluded in this generator; the separation time is 30-60 minutes; the yield of the final product is not less than 95%; impurity of 90Sr is not more than 10-9---10%; the content of the chemical (nonactive) impurities is not more than the allowed one for radiopharmaceuticals

  7. Power generation statistics

    International Nuclear Information System (INIS)

    The frost in February increased the power demand in Finland significantly. The total power consumption in Finland during January-February 2001 was about 4% higher than a year before. In January 2001 the average temperature in Finland was only about - 4 deg C, which is nearly 2 degrees higher than in 2000 and about 6 degrees higher than long term average. Power demand in January was slightly less than 7.9 TWh, being about 0.5% less than in 2000. The power consumption in Finland during the past 12 months exceeded 79.3 TWh, which is less than 2% higher than during the previous 12 months. In February 2001 the average temperature was - 10 deg C, which was about 5 degrees lower than in February 2000. Because of this the power consumption in February 2001 increased by 5%. Power consumption in February was 7.5 TWh. The maximum hourly output of power plants in Finland was 13310 MW. Power consumption of Finnish households in February 2001 was about 10% higher than in February 2000, and in industry the increase was nearly zero. The utilization rate in forest industry in February 2001 decreased from the value of February 2000 by 5%, being only about 89%. The power consumption of the past 12 months (Feb. 2000 - Feb. 2001) was 79.6 TWh. Generation of hydroelectric power in Finland during January - February 2001 was 10% higher than a year before. The generation of hydroelectric power in Jan. - Feb. 2001 was nearly 2.7 TWh, corresponding to 17% of the power demand in Finland. The output of hydroelectric power in Finland during the past 12 months was 14.7 TWh. The increase from the previous 12 months was 17% corresponding to over 18% of the power demand in Finland. Wind power generation in Jan. - Feb. 2001 was exceeded slightly 10 GWh, while in 2000 the corresponding output was 20 GWh. The degree of utilization of Finnish nuclear power plants in Jan. - Feb. 2001 was high. The output of these plants was 3.8 TWh, being about 1% less than in Jan. - Feb. 2000. The main cause for the

  8. Electric power generation

    International Nuclear Information System (INIS)

    Apart from discussing some principles of power industry the present text deals with the different ways of electric power generation. Both the conventional methods of energy conversion in heating and water power stations and the facilities for utilizing regenerative energy sources (sun, wind, ground heat, tidal power) are considered. The script represents the essentials of the lecture of the same name which is offered to the students of the special subject 'electric power engineering' at the Fachhochschule Hamburg. It does not require any special preliminary knowledge except for the general principles of electrical engineering. It is addressing students of electrical engineering who have passed their preliminary examination at technical colleges and universities. Moreover, it shall also be of use for engineers who want to obtain a quick survey of the structure and the operating characteristics of the extremely different technical methods of power generation. (orig.)

  9. Why three generations?

    Directory of Open Access Journals (Sweden)

    Masahiro Ibe

    2016-07-01

    Full Text Available We discuss an anthropic explanation of why there exist three generations of fermions. If one assumes that the right-handed neutrino sector is responsible for both the matter–antimatter asymmetry and the dark matter, then anthropic selection favors three or more families of fermions. For successful leptogenesis, at least two right-handed neutrinos are needed, while the third right-handed neutrino is invoked to play the role of dark matter. The number of the right-handed neutrinos is tied to the number of generations by the anomaly constraints of the U(1B−L gauge symmetry. Combining anthropic arguments with observational constraints, we obtain predictions for the X-ray observations, as well as for neutrinoless double-beta decay.

  10. Why three generations?

    CERN Document Server

    Ibe, Masahiro; Yanagida, Tsutomu T

    2016-01-01

    We discuss an anthropic explanation of why there exist three generations of fermions. If one assumes that the right-handed neutrino sector is responsible for both the matter-antimatter asymmetry and the dark matter, then anthropic selection favors three or more families of fermions. For successful leptogenesis, at least two right-handed neutrinos are needed, while the third right-handed neutrino is invoked to play the role of dark matter. The number of the right-handed neutrinos is tied to the number of generations by the anomaly constraints of the $U(1)_{B-L}$ gauge symmetry. Combining anthropic arguments with observational constraints, we obtain predictions for the $X$-ray observations, as well as for neutrinoless double-beta decay.

  11. The intense neutron generator

    International Nuclear Information System (INIS)

    The presentation discusses both the economic and research contexts that would be served by producing neutrons in gram quantities at high intensities by electrical means without uranium-235. The revenue from producing radioisotopes is attractive. The array of techniques introduced by the multipurpose 65 megawatt Intense Neutron Generator project includes liquid metal cooling, superconducting magnets for beam bending and focussing, super-conductors for low-loss high-power radiofrequency systems, efficient devices for producing radiofrequency power, plasma physics developments for producing and accelerating hydrogen, ions at high intensity that are still far out from established practice, a multimegawatt high voltage D.C. generating machine that could have several applications. The research fields served relate principally to materials science through neutron-phonon and other quantum interactions as well as through neutron diffraction. Nuclear physics is served through μ-, π- and K-meson production. Isotope production enters many fields of applied research. (author)

  12. Automated synthetic scene generation

    Science.gov (United States)

    Givens, Ryan N.

    Physics-based simulations generate synthetic imagery to help organizations anticipate system performance of proposed remote sensing systems. However, manually constructing synthetic scenes which are sophisticated enough to capture the complexity of real-world sites can take days to months depending on the size of the site and desired fidelity of the scene. This research, sponsored by the Air Force Research Laboratory's Sensors Directorate, successfully developed an automated approach to fuse high-resolution RGB imagery, lidar data, and hyperspectral imagery and then extract the necessary scene components. The method greatly reduces the time and money required to generate realistic synthetic scenes and developed new approaches to improve material identification using information from all three of the input datasets.

  13. Next Generation Pneumococcal Vaccines

    OpenAIRE

    Kristin L Moffitt; Malley, Richard

    2011-01-01

    Currently licensed pneumococcal vaccines are based on the generation of antibodies to the pneumococcal polysaccharide, of which there are more than 90 different types. While these vaccines are highly effective against the serotypes included, their high cost and limited serotype coverage limits their usefulness worldwide, particularly in low resources areas. Thus alternative or adjunctive options are being actively pursued. This review will present these various approaches, including variation...

  14. DSP Based Waveform Generator

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The DSP Based Waveform Generator is used for CSR Control system to control special controlled objects, such as the pulsed power supply for magnets, RF system, injection and extraction synchronization, global CSR synchronization etc. This intelligent controller based on 4800 MIPS DSP and 256M SDRAM technology will supply highly stable and highly accurate reference waveform used by the power supply of magnets. The specifications are as follows:

  15. Electric power generating bicycle

    OpenAIRE

    Brito, Nuno; Ribeiro, Luís; Esteves, João Sena

    2006-01-01

    It is manifest the growing interest in both personal health and environmental issues. The device described on this paper contemplates both aspects: generating environment-friendly electric power while keeping fit. A car alternator excited through a 12V battery is coupled to a mountain bicycle, and this arrangement enables the lighting of six halogen lamps, if a cyclist pedals fast enough. Such a machine gives rise to the thought of a self-powered gymnasium. Considerable physical effort is req...

  16. Choice Probability Generating Functions

    DEFF Research Database (Denmark)

    Fosgerau, Mogens; McFadden, Daniel L; Bierlaire, Michel

    This paper considers discrete choice, with choice probabilities coming from maximization of preferences from a random utility field perturbed by additive location shifters (ARUM). Any ARUM can be characterized by a choice-probability generating function (CPGF) whose gradient gives the choice...... probabilities, and every CPGF is consistent with an ARUM. We relate CPGF to multivariate extreme value distributions, and review and extend methods for constructing CPGF for applications....

  17. Housing 'Generation Rent'

    OpenAIRE

    McKee, Kim; Hoolachan, Jennifer Elizabeth

    2015-01-01

    'Generation Rent' denotes young people under 35 who are spending longer periods of their life in the private rented sector (PRS) because of challenges accessing both home ownership and social rented housing1. The 2007 global financial crisis resulted in stricter mortgage lending criteria and larger deposit requirements, which are out of reach for many young people who are navigating difficult labour markets, and have been hit hard by welfare reform agendas2. Furthermore, the shrinkage of the ...

  18. Compactly Generated Domain Theory

    OpenAIRE

    Battenfeld, Ingo; Schröder, Matthias; Simpson, Alexander

    2006-01-01

    We propose compactly generated monotone convergence spaces as a well-behaved topological generalisation of directed-complete partial orders (dcpos). The category of such spaces enjoys the usual properties of categories of 'predomains' in denotational semantics. Moreover, such properties are retained if one restricts to spaces with a countable pseudobase in the sense of E. Michael, a fact that permits connections to be made with computability theory, realizability semantics and recent work on ...

  19. Generating Music from Literature

    OpenAIRE

    Davis, Hannah; Mohammad, Saif M.

    2014-01-01

    We present a system, TransProse, that automatically generates musical pieces from text. TransProse uses known relations between elements of music such as tempo and scale, and the emotions they evoke. Further, it uses a novel mechanism to determine sequences of notes that capture the emotional activity in the text. The work has applications in information visualization, in creating audio-visual e-books, and in developing music apps.

  20. Second generation governance indicators

    OpenAIRE

    Knack, Stephen; Kugler, Mark; Manning, Nick

    2002-01-01

    This paper summarizes progress made in a DfID-funded World Bank initiative to test and develop policy-relevant, politically acceptable, quantitative indicators of governance. There are two major components involved in the process of generating indicators that are practical means of reform. Political acceptability is key in developing neutral quantitative benchmarks of good governance that can be embraced by reformers. In addition to political acceptability, measuring governance must be com...