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Journal articles on the topic "Phage filamenteux"

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Souriau, C., The Duc Hua, MP Lefranc, and M. Weill. "Présentation a la surface de phages filamenteux : les multiples applications du phage display." médecine/sciences 14, no. 3 (1998): 300. http://dx.doi.org/10.4267/10608/1033.

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Faruque, Shah M., Iftekhar Bin Naser, Kazutaka Fujihara, Pornphan Diraphat, Nityananda Chowdhury, M. Kamruzzaman, Firdausi Qadri, Shinji Yamasaki, A. N. Ghosh, and John J. Mekalanos. "Genomic Sequence and Receptor for the Vibrio cholerae Phage KSF-1Φ: Evolutionary Divergence among Filamentous Vibriophages Mediating Lateral Gene Transfer." Journal of Bacteriology 187, no. 12 (June 15, 2005): 4095–103. http://dx.doi.org/10.1128/jb.187.12.4095-4103.2005.

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ABSTRACT KSF-1Φ, a novel filamentous phage of Vibrio cholerae, supports morphogenesis of the RS1 satellite phage by heterologous DNA packaging and facilitates horizontal gene transfer. We analyzed the genomic sequence, morphology, and receptor for KSF-1Φ infection, as well as its phylogenetic relationships with other filamentous vibriophages. While strains carrying the mshA gene encoding mannose-sensitive hemagglutinin (MSHA) type IV pilus were susceptible to KSF-1Φ infection, naturally occurring MSHA-negative strains and an mshA deletion mutant were resistant. Furthermore, d-mannose as well as a monoclonal antibody against MSHA inhibited infection of MSHA-positive strains by the phage, suggesting that MSHA is the receptor for KSF-1Φ. The phage genome comprises 7,107 nucleotides, containing 14 open reading frames, 4 of which have predicted protein products homologous to those of other filamentous phages. Although the overall genetic organization of filamentous phages appears to be preserved in KSF-1Φ, the genomic sequence of the phage does not have a high level of identity with that of other filamentous phages and reveals a highly mosaic structure. Separate phylogenetic analysis of genomic sequences encoding putative replication proteins, receptor-binding proteins, and Zot-like proteins of 10 different filamentous vibriophages showed different results, suggesting that the evolution of these phages involved extensive horizontal exchange of genetic material. Filamentous phages which use type IV pili as receptors were found to belong to different branches. While one of these branches is represented by CTXΦ, which uses the toxin-coregulated pilus as its receptor, at least four evolutionarily diverged phages share a common receptor MSHA, and most of these phages mediate horizontal gene transfer. Since MSHA is present in a wide variety of V. cholerae strains and is presumed to express in the environment, diverse filamentous phages using this receptor are likely to contribute significantly to V. cholerae evolution.
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Chibani, Cynthia Maria, Robert Hertel, Michael Hoppert, Heiko Liesegang, and Carolin Charlotte Wendling. "Closely Related Vibrio alginolyticus Strains Encode an Identical Repertoire of Caudovirales-Like Regions and Filamentous Phages." Viruses 12, no. 12 (November 27, 2020): 1359. http://dx.doi.org/10.3390/v12121359.

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Many filamentous vibriophages encode virulence genes that lead to the emergence of pathogenic bacteria. Most genomes of filamentous vibriophages characterized up until today were isolated from human pathogens. Despite genome-based predictions that environmental Vibrios also contain filamentous phages that contribute to bacterial virulence, empirical evidence is scarce. This study aimed to characterize the bacteriophages of a marine pathogen, Vibrio alginolyticus (Kiel-alginolyticus ecotype) and to determine their role in bacterial virulence. To do so, we sequenced the phage-containing supernatant of eight different V. alginolyticus strains, characterized the phages therein and performed infection experiments on juvenile pipefish to assess their contribution to bacterial virulence. We were able to identify two actively replicating filamentous phages. Unique to this study was that all eight bacteria of the Kiel-alginolyticus ecotype have identical bacteriophages, supporting our previously established theory of a clonal expansion of the Kiel-alginolyticus ecotype. We further found that in one of the two filamentous phages, two phage-morphogenesis proteins (Zot and Ace) share high sequence similarity with putative toxins encoded on the Vibrio cholerae phage CTXΦ. The coverage of this filamentous phage correlated positively with virulence (measured in controlled infection experiments on the eukaryotic host), suggesting that this phage contributes to bacterial virulence.
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Campos, Javier, Eriel Martínez, Edith Suzarte, Boris L. Rodríguez, Karen Marrero, Yussuan Silva, Talena Ledón, Ricardo del Sol, and Rafael Fando. "VGJφ, a Novel Filamentous Phage of Vibrio cholerae, Integrates into the Same Chromosomal Site as CTXφ." Journal of Bacteriology 185, no. 19 (October 1, 2003): 5685–96. http://dx.doi.org/10.1128/jb.185.19.5685-5696.2003.

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ABSTRACT We describe a novel filamentous phage, designated VGJφ, isolated from strain SG25-1 of Vibrio cholerae O139, which infects all O1 (classical and El Tor) and O139 strains tested. The sequence of the 7,542 nucleotides of the phage genome reveals that VGJφ has a distinctive region of 775 nucleotides and a conserved region with an overall genomic organization similar to that of previously characterized filamentous phages, such as CTXφ of V. cholerae and Ff phages of Escherichia coli. The conserved region carries 10 open reading frames (ORFs) coding for products homologous to previously reported peptides of other filamentous phages, and the distinctive region carries one ORF whose product is not homologous to any known peptide. VGJφ, like other filamentous phages, uses a type IV pilus to infect V. cholerae; in this case, the pilus is the mannose-sensitive hemagglutinin. VGJφ-infected V. cholerae overexpresses the product of one ORF of the phage (ORF112), which is similar to single-stranded DNA binding proteins of other filamentous phages. Once inside a cell, VGJφ is able to integrate its genome into the same chromosomal attB site as CTXφ, entering into a lysogenic state. Additionally, we found an attP structure in VGJφ, which is also conserved in several lysogenic filamentous phages from different bacterial hosts. Finally, since different filamentous phages seem to integrate into the bacterial dif locus by a general mechanism, we propose a model in which repeated integration events with different phages might have contributed to the evolution of the CTX chromosomal region in V. cholerae El Tor.
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Chopin, Marie-Christine, Annette Rouault, S. Dusko Ehrlich, and Michel Gautier. "Filamentous Phage Active on the Gram-Positive Bacterium Propionibacterium freudenreichii." Journal of Bacteriology 184, no. 7 (April 1, 2002): 2030–33. http://dx.doi.org/10.1128/jb.184.7.2030-2033.2002.

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ABSTRACT We present the first description of a single-stranded DNA filamentous phage able to replicate in a gram-positive bacterium. Phage B5 infects Propionibacterium freudenreichii and has a genome consisting of 5,806 bases coding for 10 putative open reading frames. The organization of the genome is very similar to the organization of the genomes of filamentous phages active on gram-negative bacteria. The putative coat protein exhibits homology with the coat proteins of phages PH75 and Pf3 active on Thermus thermophilus and Pseudomonas aeruginosa, respectively. B5 is, therefore, evolutionarily related to the filamentous phages active on gram-negative bacteria.
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Lin, Nien-Tsung, Tzu-Jun Liu, Tze-Ching Lee, Bih-Yuh You, Ming-Haw Yang, Fu-Shyan Wen, and Yi-Hsiung Tseng. "The Adsorption Protein Genes of Xanthomonas campestris Filamentous Phages Determining Host Specificity." Journal of Bacteriology 181, no. 8 (April 15, 1999): 2465–71. http://dx.doi.org/10.1128/jb.181.8.2465-2471.1999.

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ABSTRACT Gene III (gIII) of φLf, a filamentous phage specifically infecting Xanthomonas campestris pv. campestris, was previously shown to encode a virion-associated protein (pIII) required for phage adsorption. In this study, the transcription start site for the gene and the N-terminal sequence of the protein were determined, resulting in the revision of the translation initiation site from the one previously predicted for this gene. For comparative study, the gIII of φXv, a filamentous phage specifically infecting X. campestris pv. vesicatoria, was cloned and sequenced. The deduced amino acid sequences of these two pIIIs exhibit a high degree of identity in their C-terminal halves and possess the structural features typical of the adsorption proteins of filamentous phages: a signal sequence in the N terminus, a long glycine-rich region near the center, and a hydrophobic membrane anchorage domain in the C terminus. The regions between gIII and the upstreamgVIII, 128 nucleotides in both phages, are larger than those of other filamentous phages. A hybrid phage of φXv, consisting of the φLf pIII and all the other components derived from φXv, was able to infect X. campestris pv. campestris but notX. campestris pv. vesicatoria, indicating thatgIII is the gene specifying host specificity and demonstrating the interchangeability of the pIIIs.
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Barbas, S. M., and C. F. Barbas. "Filamentous phage display." Fibrinolysis 8 (January 1994): 245–52. http://dx.doi.org/10.1016/0268-9499(94)90722-6.

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Goehlich, Henry, Olivia Roth, and Carolin C. Wendling. "Filamentous phages reduce bacterial growth in low salinities." Royal Society Open Science 6, no. 12 (December 2019): 191669. http://dx.doi.org/10.1098/rsos.191669.

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Being non-lytic, filamentous phages can replicate at high frequencies and often carry virulence factors, which are important in the evolution and emergence of novel pathogens. However, their net effect on bacterial fitness remains unknown. To understand the ecology and evolution between filamentous phages and their hosts, it is important to assess (i) fitness effects of filamentous phages on their hosts and (ii) how these effects depend on the environment. To determine how the net effect on bacterial fitness by filamentous phages changes across environments, we constructed phage–bacteria infection networks at ambient 15 practical salinity units (PSU) and stressful salinities (11 and 7 PSU) using the marine bacterium, Vibrio alginolyticus and its derived filamentous phages as model system. We observed no significant difference in network structure at 15 and 11 PSU. However, at 7 PSU phages significantly reduced bacterial growth changing network structure. This pattern was mainly driven by a significant increase in bacterial susceptibility. Our findings suggest that filamentous phages decrease bacterial growth, an indirect measure of fitness in stressful environmental conditions, which might impact bacterial communities, alter horizontal gene transfer events and possibly favour the emergence of novel pathogens in environmental Vibrios .
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Campos, Javier, Eriel Martínez, Yovanny Izquierdo, and Rafael Fando. "VEJφ, a novel filamentous phage of Vibrio cholerae able to transduce the cholera toxin genes." Microbiology 156, no. 1 (January 1, 2010): 108–15. http://dx.doi.org/10.1099/mic.0.032235-0.

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A novel filamentous bacteriophage, designated VEJφ, was isolated from strain MO45 of Vibrio cholerae of the O139 serogroup. A molecular characterization of the phage was carried out, which included sequencing of its whole genome, study of the genomic structure, identification of the phage receptor, and determination of the function of some of the genes, such as those encoding the major capsid protein and the single-stranded DNA-binding protein. The genome nucleotide sequence of VEJφ, which consists of 6842 bp, revealed that it is organized in modules of functionally related genes in an array that is characteristic of the genus Inovirus (filamentous phages). VEJφ is closely related to other previously described filamentous phages of V. cholerae, including VGJφ, VSK and fs1. Like these phages, VEJφ uses as a cellular receptor the type IV fimbria called the mannose-sensitive haemagglutinin (MSHA). It was also demonstrated that VEJφ, like phage VGJφ, is able to transmit the genome of phage CTXφ, and therefore the genes encoding the cholera toxin (CT), horizontally among populations of V. cholerae expressing the MSHA receptor fimbria. This suggests that the variety of phages implicated in the horizontal transmission of the CT genes could be more diverse than formerly thought.
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Cairns, Johannes, Sebastián Coloma, Kaarina Sivonen, and Teppo Hiltunen. "Evolving interactions between diazotrophic cyanobacterium and phage mediate nitrogen release and host competitive ability." Royal Society Open Science 3, no. 12 (December 2016): 160839. http://dx.doi.org/10.1098/rsos.160839.

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Interactions between nitrogen-fixing (i.e. diazotrophic) cyanobacteria and their viruses, cyanophages, can have large-scale ecosystem effects. These effects are mediated by temporal alterations in nutrient availability in aquatic systems owing to the release of nitrogen and carbon sources from cells lysed by phages, as well as by ecologically important changes in the diversity and fitness of cyanobacterial populations that evolve in the presence of phages. However, ecological and evolutionary feedbacks between phages and nitrogen-fixing cyanobacteria are still relative poorly understood. Here, we used an experimental evolution approach to test the effect of interactions between a common filamentous, nitrogen-fixing cyanobacterium ( Nodularia sp.) and its phage on cellular nitrogen release and host properties. Ecological, community-level effects of phage-mediated nitrogen release were tested with a phytoplankton bioassay. We found that cyanobacterial nitrogen release increased significantly as a result of viral lysis, which was associated with enhanced growth of phytoplankton species in cell-free filtrates compared with phage-resistant host controls in which lysis and subsequent nutrient release did not occur after phage exposure. We also observed an ecologically important change among phage-evolved cyanobacteria with phage-resistant phenotypes, a short-filamentous morphotype with reduced buoyancy compared with the ancestral long-filamentous morphotype. Reduced buoyancy might decrease the ability of these morphotypes to compete for light compared with longer, more buoyant filaments. Together, these findings demonstrate the potential of cyanobacteria–phage interactions to affect ecosystem biogeochemical cycles and planktonic community dynamics.
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Dissertations / Theses on the topic "Phage filamenteux"

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Mouville, Clémence. "Interaction entre les pili de type IV et le phage filamenteux MDA : impact potentiel sur la virulence de Neisseria meningitidis." Electronic Thesis or Diss., Université Paris Cité, 2024. http://www.theses.fr/2024UNIP5235.

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Neisseria meningitidis (Nm) est une bactérie commensale du nasopharynx humain qui traverse quelques fois la barrière nasopharyngée et se propage dans la circulation sanguine jusqu'à atteindre les méninges. Un bactériophage filamenteux appelé MDA (Meningococcal Disease Associated) est associé aux infections invasives à méningocoques chez les jeunes adultes. Le MDA semble augmenter l'incidence de la maladie en augmentant la colonisation bactérienne au point d'entrée. L'objectif de ce travail a été de comprendre le mécanisme moléculaire précis de l'infection de Nm par le MDA. L'étude des mutants des gènes impliqués dans la machinerie des pili de type IV (PT4) a montré que l'entrée du phage nécessite un PT4 rétractable. Ce résultat est cohérent avec la littérature sur les phages Ff ou CTX qui interagissent directement avec l'extrémité du pilus. Mais aucune preuve de l'interaction du MDA avec l'extrémité du pilus n'a été trouvée. L'interaction possible entre la fibre du pilus et la capside du phage a été examinée. Comme PilE, la piline majeure, est sujette à variation antigénique, des variants de PilE qui diminuent l'entrée du phage ont été identifiés. L'infection par le phage se produit dans des populations de bactéries exprimant des séquences de PilE spécifiques. Par imagerie, nous avons montré que les pili et les MDA s'associaient ensemble. Une analyse de la charge des acides aminés de PilE et celle de la capside soutient l'hypothèse d'une interaction variable selon le variant de PilE. Finalement, il a été montré que les P4T avec un potentiel électrostatique positif favorisaient l'infection par le phage et permettaient, de plus, une forte adhésion des Nm aux cellules humaines. L'inverse est observé pour les P4T chargés négativement. Ce travail présente également les premières caractérisations de la machinerie de sécrétion du phage. Des études préliminaires avaient montré que dans un biofilm formé sur cellules épithéliales, Nm produisaient soit des pili, soit des phages, mais pas les deux en même temps. Nous avons montré que la sécrétion du phage nécessitait PilQ, PilW et TsaP de la machinerie des P4T. Les analyses bio-informatiques suggèrent que l'ORF8 du phage, qui aurait une activité ATPase, s'associerait avec l'ORF11 pour former un complexe qui interagirait avec la sécrétine bactérienne PilQ. Ce modèle est soutenu par des tests d'interaction par double-hybride. Cette interaction mobiliserait les PilQ de la bactérie, les rendant inaccessible à la machinerie de piliation. La surexpression d'ORF8 entraine une inhibition de la piliation. Ces données permettent d'établir un nouveau modèle d'interaction entre les phages filamenteux et les P4T, ce qui pourrait participer à la sélection des souches pathogènes de Nm
Neisseria meningitidis (Nm) is a commensal bacterium of the human nasopharynx that sometimes crosses the nasopharyngeal barrier and spreads through the bloodstream to reach the meninges. A filamentous bacteriophage called MDA (Meningococcal Disease Associated) is associated with invasive meningococcal disease in young adults. MDA appears to increase the incidence of the disease by increasing bacterial colonization at the point of entry. The aim of this work was to understand the precise molecular mechanism of infection of Nm by MDA. The study of mutants of genes involved in the type IV pili (T4P) machinery showed that phage entry requires a retractable T4P. This result is consistent with the literature on Ff or CTX phages, which interact directly with the pilus tip. However, no evidence was found for MDA interacting with the T4P tip. The possible interaction between the pilus fiber and the phage capsid was investigated. Since PilE, the major pilin, is subject to antigenic variation, variants of PilE that reduce phage entry were identified. Phage infection occurs in populations of bacteria that express specific PilE sequences. Using imaging, we showed that pili and MDA associate with each other. An analysis of the amino acid charge of the pilin and that of the capsid supports the hypothesis of a variable interaction depending on the PilE variant. Finally, it was shown that T4P with a positive electrostatic potential favored phage infection and allowed the bacteria to adhere strongly to human cells. The opposite is observed for negatively charged T4P. This work also presents the first characterizations of the phage secretion machinery. Previous studies had shown that in a biofilm formed on epithelial cells, Nm produce either pili or phages, but not both at the same time. We showed that phage secretion requires PilQ, PilW and TsaP of the pili machinery. Bioinformatic analyses suggest that phage ORF8, which has ATPase activity, associates with ORF11 to form a complex that interacts with the bacterial secretin PilQ. This model is supported by two-hybrid interaction assays. This interaction would mobilize the bacterial PilQ, making them inaccessible to the piliation machinery. Overexpression of ORF8 inhibits piliation. These data provide a new model for the interaction between filamentous phages and T4P, which could be involved in the selection of pathogenic strains of Nm
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Weber, Patric. "Display of trypanosomal antigens on the surface of filamentous phage /." [S.l.] : [s.n.], 1994. http://www.ub.unibe.ch/content/bibliotheken_sammlungen/sondersammlungen/dissen_bestellformular/index_ger.html.

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Deng, L. W. "Infection mechanism of filamentous bacteriophage fd : interaction between E. coli F-pilus and phage protein pIII." Thesis, University of Cambridge, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.598493.

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Gene 3 protein (pIII), a minor coat protein located at one end of the filamentous bacteriophage fd, is involved in initiating the infection by the virus of Escherichia coli cells that display an F-pilus. An introduction and the experimental materials and methods are described in Chapters 1 and 2, respectively. Chapter 3 describes the construction and expression of the N-terminal di-domain and individual domains of pIII protein. The plaque-forming assay in vivo was used to investigate the ability of the isolated pIII domains to interact with F-pilus. Chapter 4 presents the investigation of the structure of F pilus, including displaying fragments of F pilus subunit (pilin) by means of phage display technology, expression of pilin subunit and X-ray fibre-diffraction of F pilus. Site-directed alanine mutagenesis of the second N-terminal domain of pIII in the phage as well as the evaluation of their infectivity are described in Chapter 5. Chapter 6 describes the establishment of a competitive ELISA assay in vitro in order to analyse all the mutated phages. Combining the results from two assays and mapping out the affected residues on the 3D structure, a region located at the outer rim of pIII-D2 domain was implicated as the F pilus binding epitope. Second generation mutagenesis and evaluation of these mutants were performed in order to define the interface region more closely (Chapter 7). Furthermore, several pIII proteins each containing an alanine mutation were isolated to investigate whether any major disruption of protein integrity occurs. Finally, Chapter 8 places this work in perspective and offers ideas for further work.
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Lima, Mayara Ingrid Sousa. "Seleção e caracterização de peptídeos recombinantes do Mycobacterium leprae ligantes à IgG por meio da tecnologia de phage display." reponame:Repositório Institucional da FIOCRUZ, 2011. https://www.arca.fiocruz.br/handle/icict/4253.

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Submitted by Ana Maria Fiscina Sampaio (fiscina@bahia.fiocruz.br) on 2012-07-30T21:26:19Z No. of bitstreams: 1 Mayara Ingrid Sousa Lima Seleção e caracterização de peptideos....pdf: 1915651 bytes, checksum: 4954d0969cc99ed5643d45ee27772173 (MD5)
Made available in DSpace on 2012-07-30T21:26:19Z (GMT). No. of bitstreams: 1 Mayara Ingrid Sousa Lima Seleção e caracterização de peptideos....pdf: 1915651 bytes, checksum: 4954d0969cc99ed5643d45ee27772173 (MD5) Previous issue date: 2011
Fundação Oswaldo Cruz. Centro de Pesquisas Gonçalo Moniz. Salvador, Bahia,Brasil
A hanseníase é uma doença infecciosa crônica, causada pelo Mycobacterium leprae, que apresenta manifestações clínicas variadas. Essas variações refletem em diferenças que vão de uma forte resposta imune celular com controle do crescimento do bacilo, no pólo tuberculóide, a uma anergia em resposta celular, no pólo virchoviano. A caracterização do perfil antigênico do M. leprae frente a esse quadro de múltiplos aspectos clínicos representa uma ferramenta fundamental para o desenvolvimento de novas plataformas para um diagnóstico diferencial mais sensível e/ou desenvolvimento de unidades vacinais. Dessa forma, o objetivo desse trabalho foi selecionar e caracterizar peptídeos miméticos de antígenos do M. leprae reativos contra IgGs totais purificadas de pacientes com hanseníase. Para a seleção foi utilizada a tecnologia de phage display, usando bibliotecas randômicas de peptídeos expressos em fagos filamentosos. Foi realizada uma seleção com IgGs de pacientes Tuberculóides e outra com IgGs de pacientes Virchovianos. A validação dos peptídeos foi realizada utilizando o imunoensaio ELISA, o teste de redução de colônias e análise de bioinformática. Após a pré-validação e sequenciamento foram encontradas 17 mimotopos para o pólo Vichorviano e 12 no pólo Tuberculóide. Foram validados 4 peptídeos, sendo 2 do pólo Tuberculóide (T03, T04) e 2 do pólo Virchoviano (V06 e V13). Os peptídeos TALFPWL (T03) e YSTTLSY (T04) foram imunorreativos em soros de pacientes paucibacilares, bem como em pacientes Virchovianos, além de terem alinhado com proteínas de membrana do M. leprae com potencial antigênico. O peptídeo V06 apresentou especificidade de 100% e sensibilidade de 94,74%, o que se complementa com os dados do teste de redução da pIII, o qual obteve uma taxa de redução de 82% em soros Virchovianos. O peptídeo V13 também foi reativo e apresentou similaridades com chaperonas e proteínas de membrana. Este estudo aponta perspectivas para a identificação de novos antígenos, propiciando a descoberta de novos alvos biológicos com potencial diagnóstico e/ou terapêutico.
Leprosy is a chronic infectious disease caused by Mycobacterium leprae, which has varied clinical manifestations. These variations reflect differences that spans from a strong cellular mediated immunity and bacili growth control the tuberculoid pole to a poor T cell immunity at the lepromatous pole. The antigenic profile characterization in both clinical forms represents a fundamental tool for the development of new platforms for a differential diagnosis more sensitive and/or development of vaccine units. Thus, the objective was to select and characterize mimetics peptides antigens of M. leprae reactive against total IgG purified from leprosy patients. The phage display technology was used for selection using random peptides libraries expressed on filamentous phages. A selection was performed with IgGs from tuberculoid patients and other IgGs of lepromatous patients. Peptides validation was performed using the ELISA immunoassay, the plaque reduction test and bioinformatics analysis. After the pre-validation and sequencing were found 17 valid sequences for the lepromatous pole and 12 tuberculoid pole. Four peptides were validated, two of tuberculoid pole (T03, T04) and two lepromatous pole (V06 and V13). The peptides TALFPWL (T03) and YSTTLSY (T04) were imunoreatives in sera from paucibacillary patients and in lepromatous patients. They had alignment with membrane proteins of M. leprae antigenic potential. The V06 peptide showed 100% specificity and 94.74% sensitivity, which is supplemented with the plaque reduction test, who obtained a reduction rate of 82% in lepromatous sera. The V13 peptide was also reactive and showed similarities with chaperones and membrane proteins. This study presents insights for new antigens identification, leading to discovery of new biological targets with potential diagnostic or therapeutic
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Pommier, Stéphanie. "Le système Tol-Pal : l'intégrité membranaire et les interactions entre TolA, colicine A et G3p, protéine de capside des phages filamenteux." Aix-Marseille 2, 2005. http://theses.univ-amu.fr.lama.univ-amu.fr/2005AIX22070.pdf.

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Lößner, Holger. "Autolytische Salmonellen als Vektoren für die orale genetische Vakzinierung." Doctoral thesis, Humboldt-Universität zu Berlin, Mathematisch-Naturwissenschaftliche Fakultät I, 2003. http://dx.doi.org/10.18452/15000.

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Die Entwicklung einer mukosal verabreichbaren, effektiven DNA-Vakzine gegen Infektionskrankheiten oder Tumorerkrankungen auf der Basis invasiver attenuierter Bakterien ist eine vielversprechende Alternative zu bisherigen parenteralen Strategien der genetischen Vakzinierung. Innerhalb dieser Arbeit wurden Salmonellen-Impfstämme für die orale Übertragung eines eukaryontischen Expressionsplasmids mit dem kleinen Oberflächenantigen des Hepatitis-B-Virus (HBsAg) als Modellantigen optimiert. Die kontinuierliche Sezernierung von Plasmiden als filamentöse Phagenpartikel wurde als ein erster Ansatz getestet, um mit lebenden Bakterien eine DNA-Vakzine innerhalb infizierter Zellen freizusetzen. Die Salmonellen-vermittelte Phagensekretion in der Wirtszelle ist jedoch nicht effizient genug, die Expression des Transgens zu vermitteln. Alternativ wurde ein Ansatz gewählt, durch eine spontan induzierte Lyse der Impfbakterien, Plasmid-DNA in die Wirtszelle zu übertragen. Dazu wurde ein neuartiges bakterielles Autolysesystem etabliert, basierend auf einem Zwei-Phasen-Expressionssystem und von Bakteriophagen abgeleiteten Lysedeterminanten. Dieses System ermöglicht erstmals die kontinuierliche Freisetzung von Plasmid-DNA und Proteinen aus einzelnen, lysierenden Salmonellen innerhalb einer sonst gesunden bakteriellen Gesamtpopulation. Innerhalb infizierter COS7-Zellen führt die Freisetzung des porenformierenden Proteins Listeriolysin O durch autolytische Salmonellen zur Zerstörung der Vakuole, in der die Impfbakterien replizieren, und erleichtert somit den Transfer der Plasmid-DNA aus den Bakterien in das Zytoplasma der Wirtszelle. Die Lysedeterminante und die eukaryontische Expressionskassette für HBsAg wurden auf einem Plasmid kombiniert, sowie eine Kassette zur konstitutiven Expression des Histon-ähnlichen Proteins aus Thermotoga maritima (TmHU) in ein solches Konstrukt integriert. TmHU stabilisiert die Plasmiderhaltung unter nicht selektiven Bedingungen und besitzt das Potential, die Effizienz der DNA-Translokation innerhalb der Wirtszelle zu erhöhen. Durch die orale Gabe optimierter autolytischer Impfbakterien konnte eine potente HBsAg-spezifische Antikörperantwort sowie eine zytotoxische zelluläre Antwort induziert werden. Bereits die einmalige Gabe der autolytischen Bakterien induzierte eine höhere antigenspezifische Antikörperantwort, als die herkömmliche intramuskuläre DNA-Vakzine. Das im Rahmen dieser Arbeit entwickelte Konzept autolytischer Salmonellen stellt also eine neuartige, effiziente Strategie für den mukosalen DNA-Transfer dar. Die Übertragung des Konzeptes der Autolyse auf andere bakterielle Trägersysteme ist möglich und kann zur Erweiterung des Anwendungspektrums bakterieller Vektoren beitragen.
The development of an effective mucosal DNA vaccine against infectious diseases or tumors based on invasive attenuated bacteria is a very promising alternative to common parenteral routes of genetic vaccination. This work aimed at the optimization of Salmonella vaccine strains for the oral delivery of an eukaryotic expression plasmid encoding the small Hepatitis B Virus surface antigen (HBsAg), here used as model antigen. The continuous secretion of plasmids as filamentous phage particles was first tested as a mean for the delivery of the DNA vaccine by living bacteria inside infected host cells. However, Salmonella-mediated phage secretion inside cells did not suffice for the induction of transgene expression. As alternative approach, inducible spontanous lysis of bacteria was used to mediate the release of plasmid DNA into host cells. For this purpose a novel bacterial autolytic system was established on the basis of a two-phase expression system and lysis determinants derived from bacteriophages. This system allows for the first time the continuous release of plasmid DNA and proteins from only few lysing Salmonella within an otherwise healthy bacterial population. Inside COS7 cells the release of the pore-forming protein listeriolysin O by autolytic Salmonella mediates the destruction of the Salmonella-harbouring vacuole, thereby facilitating the transfer of plasmid DNA from bacteria into the host cell cytoplasm. The lysis determinant was combined with the eukaryotic expression cassette for HBsAg on one plasmid. In addition, a cassette for the constitutive expression of TmHU, a histon-like protein derived from Thermotoga maritima, was integrated in such vector. TmHU stabilizes the plasmid propagation in the absence of selective pressure and has the potential to increase the efficiency of plasmid translocation inside the host cell. The oral administration of the optimized autolytic bacteria stimulated a potent HBsAg-specific antibody response as well as a cytotoxic cellular response. Already a single inoculation of the oral vaccine induced a higher specific antibody response than the conventional intramuscular DNA vaccine. Therefore the concept of autolytic Salmonella carrier strains developed in this work constitutes a novel efficient strategy for mucosal DNA delivery. The transfer of this concept to other bacterial carriers is possible and may widen the application field for bacterial vectors.
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CHEN, SONG-YUN, and 陳松芸. "Characterization of filamentous phage Cf1t imm -." Thesis, 1992. http://ndltd.ncl.edu.tw/handle/79599876065467010926.

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LIN, JING-HUI, and 林靜慧. "Identification of DNA region involved in phage integration of filamentous phage Cflt." Thesis, 1991. http://ndltd.ncl.edu.tw/handle/03339821352724891199.

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SU, WEI-ZHI, and 蘇偉誌. "Localization of the replication origin of filamentous phage Cf." Thesis, 1990. http://ndltd.ncl.edu.tw/handle/54165762240788842565.

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Yen, Ming-Ren, and 嚴明仁. "Comparative Genomics of Filamentous Phages from Xanthomonas." Thesis, 2003. http://ndltd.ncl.edu.tw/handle/42138177638249238083.

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博士
國立中興大學
分子生物學研究所
91
Several filamentous phages from Xanthomonas, including Lf, Xv, Xo, and Cflc, have previously been reported. In this study, two novel filamentous phages, Xv2 and Xo2, were isolated from Xanthomonas axonopodis pv. vesicatoria and Xanthomonas oryzae pv. oryzae, respectively. They are similar to other filamentous phages of Xanthomonas in having (i) restrictive host specificity, (ii) a single-stranded DNA genome, (iii) a replicative form (RF) as the intermediate during propagation, and (iv) a life cycle without lysis of host cells. Sequence determination revealed that the genome of Xv2 and Xo2 are 6,293 and 8,341 nt in size, respectively, containing seven genes on the viral strand which are corresponding to those of Lf, gII, gV, gVII, gVIII, gIII, gVI, and gI, which are defined as the core genes herein. In order to elucidate the phylogenetic relatedness, the six phages were analyzed with programs BLAST, CLUSTAL-X, TREEVIEW, TMHMM, Dot plot, and SignalP. Results indicated that the genome of filamentous phages of Xanthomonas consist of three different modules i.e., DNA replication module, structure module, and morphogenesis module. Each of the modules has its own high degree of conservation. Combination of different modules thus provides diversities and results in different phages. Data of phylogenetic analyses suggested that structure module and morphogenesis module are linked during the process of evolution, implicating that there is a direct contact between coat proteins and assembly proteins during morphogenesis. The ratio of size of the region containing core genes to that of the whole genome is almost the same among different phages, but the sizes of intergenic region (IR) vary. Several open reading frames are present in the IRs and two of them, encoding a 13-kDa and a 16-kDa protein, are found in all the filamentous phages. Based on sequence analysis, these two proteins are proposed to play important roles in phage replication. A novel mini plasmid pXV1.3, with a 1,313-bp genome consisting of a single gene (rep) encoding a replication protein, was discovered in X. axonopodis pv. vesicatoria Xvt146. In the presence of a filamentous Xanthomonas phage, pXV1.3 can be packaged and released into medium becoming transducing particles, which can infect the susceptible host cells.
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Books on the topic "Phage filamenteux"

1

Roberts, Linda Marie. Characterization of the chloroform/water interface-induced contraction of the filamentous phage fd. 1990.

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Book chapters on the topic "Phage filamenteux"

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Rakonjac, Jasna, Marjorie Russel, Sofia Khanum, Sam J. Brooke, and Marina Rajič. "Filamentous Phage: Structure and Biology." In Recombinant Antibodies for Infectious Diseases, 1–20. Cham: Springer International Publishing, 2017. http://dx.doi.org/10.1007/978-3-319-72077-7_1.

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Kulseth, Mari Ann, Annette Fagerlund, and Astrid Hilde Myrset. "Affinity Selection Using Filamentous Phage Display." In Methods in Molecular Biology, 67–80. Totowa, NJ: Humana Press, 2013. http://dx.doi.org/10.1007/978-1-62703-673-3_5.

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Tasaka, Yuichi, Takeru Kawasaki, and Takashi Yamada. "Filamentous Phages Affect Virulence of the Phytopathogen Ralstonia solanacearum." In Biocommunication of Phages, 221–37. Cham: Springer International Publishing, 2020. http://dx.doi.org/10.1007/978-3-030-45885-0_11.

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Fagerlund, Annette, Astrid Hilde Myrset, and Mari Ann Kulseth. "Construction of a Filamentous Phage Display Peptide Library." In Methods in Molecular Biology, 19–33. Totowa, NJ: Humana Press, 2013. http://dx.doi.org/10.1007/978-1-62703-673-3_2.

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Ehara, Masahiko, and M. John Albert. "Filamentous Phages of Vibrio cholerae O1 and O139." In Epidemiological and Molecular Aspects on Cholera, 213–21. New York, NY: Springer New York, 2010. http://dx.doi.org/10.1007/978-1-60327-265-0_12.

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Müller, Henri, Stefan Schmideder, and Heiko Briesen. "Generalized Morphology Modeling of Aggregating, Filamentous Microorganisms." In Dispersity, Structure and Phase Changes of Proteins and Bio Agglomerates in Biotechnological Processes, 441–65. Cham: Springer Nature Switzerland, 2024. http://dx.doi.org/10.1007/978-3-031-63164-1_14.

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Cao, Binrui, and Chuanbin Mao. "Chapter 10. Filamentous Phage-templated Synthesis and Assembly of Inorganic Nanomaterials." In Nanoscience & Nanotechnology Series, 220–44. Cambridge: Royal Society of Chemistry, 2011. http://dx.doi.org/10.1039/9781847559920-00220.

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Duché, Denis, and Laetitia Houot. "Similarities and Differences between Colicin and Filamentous Phage Uptake by Bacterial Cells." In Protein Secretion in Bacteria, 375–87. Washington, DC, USA: ASM Press, 2019. http://dx.doi.org/10.1128/9781683670285.ch30.

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Cesareni, Gianni, and James A. H. Murray. "Plasmid Vectors Carrying the Replication Origin of Filamentous Single-Stranded Phages." In Genetic Engineering, 135–54. Boston, MA: Springer US, 1987. http://dx.doi.org/10.1007/978-1-4684-5377-5_9.

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Parmley, Stephen F., and George P. Smith. "Filamentous Fusion Phage Cloning Vectors for the Study of Epitopes and Design of Vaccines." In Immunobiology of Proteins and Peptides V, 215–18. Boston, MA: Springer US, 1989. http://dx.doi.org/10.1007/978-1-4757-2046-4_21.

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Conference papers on the topic "Phage filamenteux"

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Kashiwagi, Kenji, and Kiyotaka Shiba. "Filamentous Phage-Based Extra Cellular Matrix." In 2008 International Symposium on Micro-NanoMechatronics and Human Science (MHS). IEEE, 2008. http://dx.doi.org/10.1109/mhs.2008.4752484.

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Burgener, Elizabeth, Laura Rojas Hernandez, Paul Bollyky, and Carlos Milla. "The filamentous Pseudomonas phage Pf disrupts airway basal cell proliferation." In ERS International Congress 2021 abstracts. European Respiratory Society, 2021. http://dx.doi.org/10.1183/13993003.congress-2021.pa3616.

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Petrov, G. O., V. S. Mukhanov, and M. A. Dymova. "DEVELOPMENT M13 BACTERIOPHAGE-BASED TARGETED HYBRID VECTORS FOR HUMAN GLIOBLASTOMA CELL SELECTIVE TRANSDUCTION." In X Международная конференция молодых ученых: биоинформатиков, биотехнологов, биофизиков, вирусологов и молекулярных биологов — 2023. Novosibirsk State University, 2023. http://dx.doi.org/10.25205/978-5-4437-1526-1-357.

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Bacteriophages, bacterial viruses, are currently being used as source of effective gene therapy tools for cancer. The aim of this study was to develop targeted hybrid vectors based on filamentous phage M13, capable of efficient and selective delivery of transgenes into U-87 MG human glioblastoma cells.
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Pajic, Tanja, Natasa Todorovic, Dunja Stefanovic, Mihailo Rabasovic, Aleksandar Krmpot, and Miroslav Zivic. "THE EFFECTS OF SELENITE ON FILAMENTOUS FUNGI LIPID DROPLETS MONITORED „IN VIVO“ LABEL FREE USING ADVANCED NONLINEAR MICROSCOPY TECHNIQUE 2021ICCBIKG (2021)." In 1st INTERNATIONAL Conference on Chemo and BioInformatics. Institute for Information Technologies, University of Kragujevac, 2021. http://dx.doi.org/10.46793/iccbi21.300p.

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Third Harmonic Generation (THG) microscopy was employed as a method of choice for lipid droplet (LD) measurements and quantification of the effect of selenite on LDs. Nonlinear laser scanning microscopy (NLSM) employs ultra-short laser pulses for imaging. THG microscopy is the modality of NLSM. Strong THG signals can only be observed from regions with non- uniformities with respect to their refractive index. Such regions in biological samples are lipid-water interfaces, and by far the brightest features in cells are LDs. For that reason, THG microscopy is the appropriate method for imaging of LDs from live unfixed cells, without the need for additional labeling. The biological effects of spore- to- end- of- exponential- phase duration (27 – 30 h) of exposure to 1 mM selenite were monitored in vivo on the cells of filamentous fungi in liquid culture. We measured the lipid droplet density and size distribution in a model fungi Phycomyces blakesleeanus. The in-house built microscope frame complemented with Yb KGW laser (1040 nm, 200 fs pulses) was used, while detection was enabled in the transmission arm by PMT through the Hoya glass UV filter (peak at 340 nm). From THG images of control and Se+4–treated hyphae, LD size and number were measured, showing that LD density was increased by more than 60% in Se+4–treated hyphae, compared to control. The average LD size distribution seemed slightly changed by Se+4 -treatment. The obtained results suggest that 1 mM selenite treatment probably induces cellular stress response in filamentous fungi.
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Reports on the topic "Phage filamenteux"

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Benemann, John. Final Report for Phase 1 SBIR: “Power Plant CO2 Capture in Filamentous Algae for Animal Feeds”. Office of Scientific and Technical Information (OSTI), October 2018. http://dx.doi.org/10.2172/1476637.

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Dickman, Martin B., and Oded Yarden. Role of Phosphorylation in Fungal Spore Germination. United States Department of Agriculture, August 1993. http://dx.doi.org/10.32747/1993.7568761.bard.

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Spore germination is a common and fundamental event in fungal development and in many instances an essential phase of fungal infection and dissemination. Spore germination is also critical for hyperparasites to function as biocontrol agents as well as in fermentation proceses. Our common objective is to understand the mechanisms which regulated spore germination and identify factors involved in pathogenicity related prepenetration development. Our approach is to exploit the overall similarity among filamentous fungi using both a plant pathogen (Colletotricum trifolii) and a model system that is genetically sophisticated (Neurospora crassa). The simulataneous use of two organisms has the advantage of the available tools in Neurospora to rapidly advance the functional analysis of genes involved in spore germination and development of an economically important fungal phytopathogen. Towards this we have isolated a protein kinase gene from C. trifolii (TB3) that is maximally expressed during the first hour of conidial germination and prior to any visible gene tube formation. Based on sequence similarities with other organisms, this gene is likely to be involved in the proliferative response in the fungus. In addition, TB3 was able to functionally complement a N. crassa mutant (COT-1). Pharmacological studies indicated the importance of calmodulin in both germination and appressorium differentiation. Using an antisense vector from N. crassa, direct inhibition of calmodulin results in prevention of differentiation as well as pathogenicity. Both cAMP dependent protein kinase (PKA) and protein kinase C (PKC) like genes have been cloned from C. trifolii. Biochemical inhibition of PKA prevents germination; biochemical inhibitors of PKC prevents appressorium differentiation. In order to analyze reversible phosphorylation as a regulatory mechanism, some ser.thr dephosphorylative events have also been analyzed. Type 2A and Type 2B (calcineurin) phosphatases have been identified and structurally and functionally analyzed in N. crassa during this project. Both phosphatases are essential for hyphal growth and maintenance of proper hyphal architecture. In addition, a first novel-type (PPT/PP5-like) ser/thr phosphatase has been identified in a filamentous fungus. The highly collaborative project has improved our understanding of a fundamental process in fungi, and has identified targets which can be used to develop new approaches for control of fungal plant pathogens as well as improve the performance of beneficial fungi in the field and in industry. In addition, the feasibility of molecular technology transfer in comparative mycology has been demonstrated.
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