Literatura académica sobre el tema "Virus de microbes"
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Artículos de revistas sobre el tema "Virus de microbes"
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Kim, Tae-Dong y Hajime Unno. "The roles of microbes in the removal and inactivation of viruses in a biological wastewater treatment system". Water Science and Technology 33, n.º 10-11 (1 de mayo de 1996): 243–50. http://dx.doi.org/10.2166/wst.1996.0681.
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The objective of this research is to clarify the mechanism for virus removal in an activated sludge process. The roles of microbes, i.e. bacteria, protozoa and metazoa, which form activated sludge were investigated using poliovirus as a model virus. In a bacteria cultures, the virus concentration decreased in the first one hour after which no further decrease was observed. This phenomenon is explained by the interaction of bacterial floc and virus where virus was removed by reversible adsorption. On the other hand, in the mixed culture of bacteria and protozoa, or of bacteria and metazoa, the virus removal process was observed to proceed in two first-order processes. In the first stage, virus was removed from the liquid phase by adsorption onto the floc, whereas in the second stage, virus is removed by predation of the other microbes, i.e. protozoa or metazoa. Moreover, the floc-forming ability and the feeding manner of the microbes strongly affected the virus removal. Especially, a filter feeder microbe was more effective in virus removal than a detritus feeder microbe. Among the microbes used in the experiments, P. erythrophthalma which had a large mouth and a strong filter-feeding ability as well as a high floc-forming ability showed the most efficient virus removal.
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Bransfield, Robert C., Charlotte Mao y Rosalie Greenberg. "Microbes and Mental Illness: Past, Present, and Future". Healthcare 12, n.º 1 (29 de diciembre de 2023): 83. http://dx.doi.org/10.3390/healthcare12010083.
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A review of the association between microbes and mental illness is performed, including the history, relevant definitions, infectious agents associated with mental illnesses, complex interactive infections, total load theory, pathophysiology, psychoimmunology, psychoneuroimmunology, clinical presentations, early-life infections, clinical assessment, and treatment. Perspectives on the etiology of mental illness have evolved from demonic possession toward multisystem biologically based models that include gene expression, environmental triggers, immune mediators, and infectious diseases. Microbes are associated with a number of mental disorders, including autism, schizophrenia, bipolar disorder, depressive disorders, and anxiety disorders, as well as suicidality and aggressive or violent behaviors. Specific microbes that have been associated or potentially associated with at least one of these conditions include Aspergillus, Babesia, Bartonella, Borna disease virus, Borrelia burgdorferi (Lyme disease), Candida, Chlamydia, coronaviruses (e.g., SARS-CoV-2), Cryptococcus neoformans, cytomegalovirus, enteroviruses, Epstein–Barr virus, hepatitis C, herpes simplex virus, human endogenous retroviruses, human immunodeficiency virus, human herpesvirus-6 (HHV-6), human T-cell lymphotropic virus type 1, influenza viruses, measles virus, Mycoplasma, Plasmodium, rubella virus, Group A Streptococcus (PANDAS), Taenia solium, Toxoplasma gondii, Treponema pallidum (syphilis), Trypanosoma, and West Nile virus. Recognition of the microbe and mental illness association with the development of greater interdisciplinary research, education, and treatment options may prevent and reduce mental illness morbidity, disability, and mortality.
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Engevik, Kristen A. y Melinda A. Engevik. "Partners in Infectious Disease: When Microbes Facilitate Enteric Viral Infections". Gastroenterology Insights 12, n.º 1 (1 de febrero de 2021): 41–55. http://dx.doi.org/10.3390/gastroent12010005.
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The lumen of the gastrointestinal tract harbors a diverse community of microbes, fungi, archaea, and viruses. In addition to occupying the same enteric niche, recent evidence suggests that microbes and viruses can act synergistically and, in some cases, promote disease. In this review, we focus on the disease-promoting interactions of the gut microbiota and rotavirus, norovirus, poliovirus, reovirus, and astrovirus. Microbes and microbial compounds can directly interact with viruses, promote viral fitness, alter the glycan structure of viral adhesion sites, and influence the immune system, among other mechanisms. These interactions can directly and indirectly affect viral infection. By focusing on microbe–virus interplay, we hope to identify potential strategies for targeting offending microbes and minimizing viral infection.
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Kosowatz, John. "Filtering Out Microbes". Mechanical Engineering 143, n.º 1 (1 de enero de 2021): 34–35. http://dx.doi.org/10.1115/1.2021-jan3.
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Abstract A new HVAC filter, developed through a collaboration of Houston-based medical real estate developer Medistar and researchers at the University of Houston and Texas A&M University, uses a heated filter made of nickel foam that traps and kills 99.8 percent of the virus.
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González, Rubén y Marie-Anne Félix. "Naturally-associated bacteria modulate Orsay virus infection of Caenorhabditis elegans". PLOS Pathogens 20, n.º 1 (17 de enero de 2024): e1011947. http://dx.doi.org/10.1371/journal.ppat.1011947.
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Microbes associated with an organism can significantly modulate its susceptibility to viral infections, but our understanding of the influence of individual microbes remains limited. The nematode Caenorhabditis elegans is a model organism that in nature inhabits environments rich in bacteria. Here, we examine the impact of 71 naturally associated bacteria on C. elegans susceptibility to its only known natural virus, the Orsay virus. Our findings reveal that viral infection of C. elegans is significantly influenced by monobacterial environments. Compared to an Escherichia coli environmental reference, the majority of tested bacteria reduced C. elegans susceptibility to viral infection. This reduction is not caused by virion degradation or poor animal nutrition by the bacteria. The repression of viral infection by the bacterial strains Chryseobacterium JUb44 and Sphingobacterium BIGb0172 does not require the RIG-I homolog DRH-1, which is known to activate antiviral responses such as RNA interference and transcriptional regulation. Our research highlights the necessity of considering natural biotic environments in viral infection studies and opens the way future research on host-microbe-virus interactions.
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Bonachela, Juan A., Melinda Choua y Michael R. Heath. "Unconstrained coevolution of bacterial size and the latent period of plastic phage". PLOS ONE 17, n.º 5 (26 de mayo de 2022): e0268596. http://dx.doi.org/10.1371/journal.pone.0268596.
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Viruses play critical roles in the dynamics of microbial communities. Lytic viruses, for example, kill significant fractions of autotrophic and heterotrophic microbes daily. The dynamic interplay between viruses and microbes results from an overlap of physiological, ecological, and evolutionary responses: environmental changes trigger host physiological changes, affecting the ecological interactions of host and virus and, ultimately, the evolutionary pressures influencing the two populations. Recent theoretical work studied how the dependence of viral traits on host physiology (viral plasticity) affects the evolutionarily stable host cell size and viral infection time emerging from coevolution. Here, we broaden the scope of the framework to consider any coevolutionary outcome, including potential evolutionary collapses of the system. We used the case study of Escherichia coli and T-like viruses under chemostat conditions, but the framework can be adapted to any microbe-virus system. Oligotrophic conditions led to smaller, lower-quality but more abundant hosts, and infections that were longer but produced a reduced viral offspring. Conversely, eutrophic conditions resulted in fewer but larger higher-quality hosts, and shorter but more productive infections. The virus influenced host evolution decreasing host size more noticeably for low than for high dilution rates, and for high than for low nutrient input concentration. For low dilution rates, the emergent infection time minimized host need/use, but higher dilution led to an opportunistic strategy that shortened the duration of infections. System collapses driven by evolution resulted from host failure to adapt quickly enough to the evolving virus. Our results contribute to understanding the eco-evolutionary dynamics of microbes and virus, and to improving the predictability of current models for host-virus interactions. The large quantitative and qualitative differences observed with respect to a classic description (in which viral traits are assumed to be constant) highlights the importance of including viral plasticity in theories describing short- and long-term host-virus dynamics.
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Ørskov, J. "ON THE MORPHOLOGY OF PERIPNEUMONIA-VIRUS, AGALACTIA-VIRUS AND SEIFFERTS MICROBES." Acta Pathologica Microbiologica Scandinavica 19, n.º 4 (10 de agosto de 2009): 586–90. http://dx.doi.org/10.1111/j.1699-0463.1942.tb03365.x.
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Carrillo Farga, Ana María. "Idées: Ces microbes et virus qui font l’histoire". Le Courrier de l'UNESCO 2020, n.º 3 (31 de julio de 2020): 46–47. http://dx.doi.org/10.18356/9549dcb9-fr.
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Poitevin, Bernard. "Microbes. Pourquoi bactéries et virus nous sont indispensables". La Revue d'Homéopathie 2, n.º 1 (marzo de 2011): 39. http://dx.doi.org/10.1016/s1878-9730(11)70071-8.
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Khurshid, Huma, Saira Rafaqat y Sana Rafaqat. "Overview of microbes in hypertension". World Journal of Hypertension 11, n.º 2 (16 de octubre de 2023): 12–19. http://dx.doi.org/10.5494/wjh.v11.i2.12.
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High blood pressure (BP), known as hypertension, is a major contributing factor to the development of cardiovascular disease. The development and pathogenesis of hypertension involve a wide array of factors including genetics, environment, hormones, hemodynamics, and inflammation. There is a significantly positive association between higher levels of colonization by Aggregatibacter actinomycetemcomitans , Porphyromonas gingivalis , Tannerella forsythia , and Treponema denticola (etiologic bacterial burden) below the gum line, and the presence of hypertension. The use of antibiotics during pregnancy, which is likely indicative of bacterial infections severe enough to require antibiotic treatment, is associated with a slight increase in average arterial BP. Cytomegalovirus infection is a risk factor for heightened arterial BP and acts as a co-factor in the development of aortic atherosclerosis. The relationship between hypertension and coronavirus disease 2019 involves endothelial dysfunction and dysregulation of the renin-angiotensin system. The effects of gut microbiota on BP, whether beneficial or harmful, are influenced by multiple factors including genetics, epigenetics, lifestyle choices, and antibiotic usage. These variables collectively contribute to overall BP levels and the control of hypertension. Several reports have examined the BP levels of patients infected with the Zika virus. In regions with a high incidence of nasopharyngeal carcinoma, hypertension has been linked to a higher risk of Epstein-Barr virus reactivation. Also, a potential causal link has been found between malaria and elevated BP. Also, the elevated prevalence of hypertension among dengue patients during their initial visit suggests that relying solely on BP measurements to predict severe infection may not be clinically reliable.
Tesis sobre el tema "Virus de microbes"
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Coves, Marion. "Les dynamiques hôte-virus dans les digesteurs anaérobies sous l'effet d'un stress abiotique". Electronic Thesis or Diss., université Paris-Saclay, 2024. http://www.theses.fr/2024UPASB040.
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Les virus des microbes sont des acteurs majeurs dans divers écosystèmes, affectant la structuration et la dynamique des communautés microbiennes. Cependant, ils restent peu explorés dans le domaine de la digestion anaérobie (DA). Les écosystèmes de ces processus sont très sensibles aux perturbations, entraînant inhibition et diminution de la production de méthane. Cette thèse aborde l'interaction entre des perturbations abiotiques, la composition des communautés microbienne et virale et la performance du procédé.La dynamique des populations virales a été étudiée dans des digesteurs anaérobies, grâce au séquençage ‘shotgun' du métavirome. L'objectif était d'évaluer si la production de virus tempérés peut être déclenchée par des stress abiotiques connus pour inhiber la DA, via l'induction de provirus. Un second objectif était de déchiffrer de nouvelles paires virus-hôtes, grâce à des approches bioinformatiques. Nous avons constaté que les diversités des procaryotes et des virus étaient élevées, l'ordre Clostridiales dominant la communauté procaryote et la classe Caudoviricetes dominant la communauté virale. De nombreux virus et hôtes ont été identifiés comme étant différentiellement abondants dans des conditions perturbatrices, avec une bonne cohérence entre les dynamiques des hôtes et celles des virus. Nos résultats n'ont montré aucun impact significatif de ces stress abiotiques sur l'induction de prophage, ce qui indique que les virus pourraient avoir eu des effets modérés et sans rupture au fil du temps, plutôt que des effets massifs et soudains.Par ailleurs, cette étude étend les connaissances sur la DA et confirme l'importante diversité et la nouveauté des virus de la DA. Le génome d'un nouveau virus en forme de fuseau a été annoté manuellement avec d'autres génomes viraux. Cela pourrait conduire à l'établissement d'une nouvelle famille de virus d'archées méthanogènesViruses of microbes are major players in various ecosystems, influencing the structure and dynamics of microbial communities. Despite this, their presence and impact in anaerobic digestion (AD) processes remain underexplored. AD ecosystems are highly sensitive to disturbances, which can lead to inhibition and reduced methane production. In this PhD work, I investigated the interplay between abiotic disturbance, microbial community composition - including viromes - and AD process performance. I monitored viral population dynamics in anaerobic digesters using metavirome shotgun sequencing. One objective was to determine whether abiotic stresses known to inhibit AD can trigger the production of temperate viruses through provirus induction. Another aim was to identify novel virus-host pairs by employing bioinformatics approaches. The results revealed high diversity among both prokaryotes and viruses, with Clostridiales dominating the prokaryotic community and Caudoviricetes prevailing in the microbial viruses. Numerous viruses and hosts showed differential abundance under disturbing conditions, with a strong concordance between host and virus dynamics. Contrary to expectations, abiotic stresses did not significantly induce prophages, suggesting that viruses may exert a more gradual influence over time rather than causing abrupt “time bomb” effects. Additionally, this study expands the knowledge on AD, highlighting the significant diversity and novelty of AD viruses. I identified new virus-host pairs and annotated manually the genome of a novel spindle-shaped virus, along with other viral genomes. This may lead to the creation of a new family of viruses infecting methanogenic archaea
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Mougari, Saïd. "Les virophages et leurs virus géants". Thesis, Aix-Marseille, 2019. http://theses.univ-amu.fr.lama.univ-amu.fr/191122_MOUGARI_242gmgihl385pqg850mu249uauon_TH.pdf.
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Les virophages sont des virus satellites-like qui dépendent de la co-infection de leur cellule hôte avec un virus géant pour se multiplier. Ils sont actuellement classés dans la famille des Lavidaviridae. Dans la première partie de cette thèse, toutes les données actuelles concernant la découverte, l’isolement et la diversité, le cycle de réplication, l’origine, l’implication dans différents systèmes de défense viraux et cellulaires, ainsi que la classification et la définition des virophages, ont été regroupées dans une revue de littérature scientifique. La deuxième partie de cette thèse a contribué à l’expansion de la famille des virophages grâce à l’isolement de deux nouveaux membres de cette famille. La troisième partie de ce travail se focalise sur les interactions entre les virophages d’un côté et leurs virus géants et cellules hôtes de l’autre côté. Dans un premier projet, nous avons développé un protocole de manipulation génétique des virus géants afin d’étudier le système de défense MIMIVIRE qui protège les mimivirus du groupe « A » contre le virophage Zamilon. Les travaux réalisés dans ce projet confirment le rôle crucial de la séquence MIMIVIRE dans le mécanisme d’interférence et mettent le point sur l’importance fonctionnelle de l’intégrité structurelle de cette séquence dans la résistance aux virophages. Dans un autre projet, nous avons décrit pour la première fois un phénomène d’expansion de la gamme d’hôte chez un virophage, ainsi que le mécanisme génétique impliqué dans ce phénomène. Nos résultats soulignent un impact écologique potentiel de cette adaptation en démontrant une capacité du virophage à induire l’extinction de son nouveau virus géant hôteVirophages are satellite-like viruses that require the presence of a giant virus co-infecting their host cell to replicate. They are currently classified in the family Lavidaviridae. In the first section of this thesis work, we presented in the form of a review, an update of all the knowledge regarding virophage discovery, isolation and diversity, replication cycle, origin, involvement in viral and cellular host-defense systems, as well as their classification and definition. The second section of this thesis contributes to the expansion of the virophage family by isolating and characterizing two new members. The third section of this thesis focuses on the study of interactions between virophages with their giant viruses and host cells. First, we have developed a protocol for genetic manipulation of giant viruses to study the MIMIVIRE system that protects mimiviruses belonging to lineage « A » from Zamilon virophage. The results presented in this part confirm the crucial role of MIMIVIRE in the interference mechanism. We additionally highlighted the functional role of the structural integrity of the MIMIVIRE sequence in the process of resistance to Zamilon. Second, we described for the first time, a host range expansion in a virophage. We were also able to identify the genetic component involved in this mechanism. Moreover, the results presented in this study highlight a potential ecological impact of this host adaptation by demonstrating a capacity of the mutant virophage to cause the extinction of its giant virus host
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Baurès, Isabelle. "Caractérisation moléculaire de l’éliciteur et analyse des partenaires requis pour la résistance à des virus contrôlée par le gène Rx de pomme de terre chez les plantes cultivées". Thesis, Evry-Val d'Essonne, 2008. http://www.theses.fr/2008EVRY0001.
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Le gène de résistance (Rx) au virus X de la pomme de terre (PVX) code pour une molécule réceptrice qui interagit avec la protéine de capside (CP) du PVX conférant ainsi une résistance à la plante. Les mécanismes de résistance sont encore peu compris. Dans ce projet, nous nous intéressons à la caractérisation de cette interaction. Le premier objectif est de caractériser l’élicitation par la CP. Nous avons d’abord mutagénéisé deux acides aminés clés de la CP du PVX et montré que le niveau de la réponse par Rx est dépendant de l’affinité de l’éliciteur avec le récepteur. Nous montrons également que les CP de virus proches du PVX, présentant des variations naturelles de séquences, sont capables d’induire une résistance par Rx. Le second objectif est d’identifier les partenaires de cette résistance. Une collection de mutants EMS de tomates portant le gène Rx a été générée. Trois plantes présentant un défaut de résistance vis-à-vis du PVX ont été isolées et sont en cours de caractérisationIn potato, the resistance gene (Rx) encodes a protein that confers resistance against Potato virus X (PVX). The trigger of the resistance is the recognition of PVX coat protein (CP). The mechanisms of this resistance are not well understood. In this project we investigate two different aspects of this interaction. The first goal of this project is to characterize the CP elicitor. In the first approach we mutagenized key amino acids in the PVX CP and showed that the affinity between elicitor and receptor modulates the intensity of the Rx response. In the second approach we showed that other viruses related to PVX with natural sequence variations in the CP are able to induce Rx mediated resistance. The second goal of this project is to identify genes required for Rx mediated resistance a collection of EMS mutants tomato (cv Micro-Tom) carrying the Rx gene has been generated and screened for restored susceptibility to PVX. Three mutants were identified and characterized
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Declercq, Marion. "Host RNA degradation pathways and influenza A virus interplay : identification of a major role of the cellular exonuclease ERI1 in the influenza A virus life cycle". Thesis, Université de Paris (2019-....), 2019. https://theses.md.univ-paris-diderot.fr/DECLERCQ_Marion_va1.pdf.
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Les mécanismes de dégradation de l'ARN représentent un processus cellulaire central. En effet, ils contrôlent la stabilité et la qualité de l'ARN et, par conséquent, régulent l'expression des gènes. D’une part, la régulation de la stabilité des transcrits est un élément essentiel au maintien de l’homéostasie cellulaire mais aussi à l’établissement d’une réponse cellulaire adaptée en cas d’infection virale. D’autre part, le succès de l’infection virale dépend fortement de la capacité du virus à prendre le contrôle des machineries d’expression géniques cellulaires. De ce fait, les virus doivent interagir avec les machineries cellulaires de dégradation de l’ARN afin de contrôler à la fois, l’expression des gènes cellulaires, et celle des gènes viraux. De nombreuses études rapportent l’existence d’une interface majeure d’interaction entre les machineries eucaryotes de dégradation de l’ARN et les protéines virales. Les virus ont non seulement la capacité d’échapper aux voies cellulaires de dégradation, mais ils peuvent également manipuler ces mécanismes cellulaires de dégradation de l’ARN afin de promouvoir leur propre réplication.Les virus influenza de type A (IAV) sont des agents pathogènes majeurs responsables d'épidémies annuelles et de pandémies occasionnelles. Pour leur cycle de réplication, les IAV dépendent de nombreuses protéines cellulaires et établissent ainsi un vaste et complexe réseau d’interactions avec le protéome cellulaire. Par ailleurs, plusieurs études rapportent l’existence de liens étroits entre les IAV et les machineries de dégradation de l’ARN. Ainsi, identifier les interactions mises en jeu lors du cycle viral participe à une meilleure compréhension du cycle viral, nécessaire au développement de stratégies antivirales. Nous avons recherché des interactions entre les protéines virales impliquées dans la réplication des IAV et un ensemble de 75 protéines cellulaires portant des activités exoribonucléases et/ou associées aux mécanismes de dégradation de l'ARN. Au total, 18 protéines ont été identifiées comme interagissant avec au moins une des protéines virales testées. Par ailleurs, l'analyse du réseau d'interaction a mis en évidence un ciblage spécifique et préférentiel des voies de dégradation de l'ARN par les protéines des IAV. Enfin, parmi les interacteurs validés, un criblage par ARN interférence a identifié neuf facteurs comme étant nécessaires à la multiplication virale.Nous avons choisi de nous concentrer sur l’exoribonucléase 1 (ERI1), identifiée comme interacteur de plusieurs composants des RNPv (RiboNucleoProtéine virale) (PB2, PB1 et NP). ERI1, via ses différents rôles dans l’homéostasie des petits ARN régulateurs, dans la maturation des ARN ribosomiques ou dans la maturation et la dégradation des ARNm histones possède un rôle central dans le contrôle de l’expression génique. En explorant l’interaction entre ERI1 et les protéines virales au cours de l’infection, nous avons mis en évidence que i) ERI1 favorise la transcription virale et que, pour ce faire, ses deux activités - liaison à l’ARN et exonucléase - sont nécessaires, ii) ERI1 interagit avec les protéines virales de manière dépendante de l’ARN, iii) ERI1 interagit avec les RNPv, iv) les protéines virales interagissent avec une forme d'ERI1 associée aux ARNm histones. Ainsi, nos données tendent vers un modèle dans lequel ERI1 associée aux ARNm histones est cooptée par la polymérase virale en transcription, favorisant ainsi la multiplication des IAV par un mécanisme qui reste cependant encore à déterminer. Ainsi, le ciblage de ERI1 par les IAV représente un autre exemple du détournement des machineries de dégradation de l’ARN par les virus, visant à créer un environnement cellulaire favorable à la réplication viraleRNA decay is a central cellular process as it regulates RNA stability and quality and thereby gene expression, which is essential to ensure proper cellular physiology and establishment of adapted responses to viral infection. Global takeover of gene expression machineries and rewiring of the cellular environment is key to the success of viral infection. Cellular proteome and viral replication are tightly connected and cellular RNA processing, stability, quality and decay accordingly influence the fate of the viral cycle. Growing evidence points towards the existence of a large interplay between eukaryotic RNA turnover machineries and viral proteins. Viruses not only evolved mechanisms to evade those RNA degradation pathways, but they also manipulate them to promote viral replication.Influenza A viruses (IAV) are major pathogens responsible for yearly epidemics and occasional pandemics. To complete their viral cycle, IAVs rely on many cellular proteins and establish a complex and highly coordinated interplay with the host proteome. Growing evidence supports the existence of a complex interplay between IAV viral proteins and RNA decay machineries. Unraveling such interplay is therefore essential to gain a better understanding of the IAV life cycle, required for the development of antiviral strategies. This led us to systematically screen interactions between viral proteins involved in IAV replication and a selected set of 75 cellular proteins carrying exoribonucleases activities or associated with RNA decay machineries. A total of 18 proteins were identified as interactors of at least one viral protein tested. Analysis of the interaction network highlighted a specific and preferential targeting of RNA degradation pathways by IAV proteins. Among validated interactors, a targeted RNAi screen identified nine factors as required for viral multiplication. We chose to focus on the 3’-5’ exoribonuclease 1 (ERI1), found in our screen as an interactor of several components of the vRNPs (viral RiboNucleoProtein) (PB2, PB1 and NP). The ERI1 protein is a major player in the control of cellular gene expression as it is essential for the maturation and decay of histone mRNA, maturation of 5.8S rRNA and miRNA homeostasis in mammalian cells. Exploring the interplay between ERI1 and viral proteins during the course of IAV infection we found that i) ERI1 promotes viral transcription, and both of its activities – RNA binding and exonuclease – are required, ii) ERI1 interacts with viral proteins in an RNA dependent manner, iii) ERI1 interacts with the transcribing vRNPs, iv) viral proteins interact with a form of ERI1 that is associated to histone mRNA. Ultimately, our data point to a model where ERI1 associated to histone mRNA is co-opted by the transcribing viral polymerase, thereby promoting IAV multiplication, through a mechanism that remains to be precisely determined. Targeting of ERI1 by IAV is another example further supporting the intricate interplay between IAV and RNA decay machineries, used to rewire cellular gene expression in order to create a favorable environment for viral replication
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Van, Munster Manuela. "Caractérisation biologique et moléculaire de virus infectant les pucerons et évaluation de leur potentiel comme biopesticides". Montpellier 2, 2002. http://www.theses.fr/2002MON20160.
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Ory, Pascaline. "Interactions entre les virus, les flagellés et les bactéries au sein du réseau microbien planctonique du bassin de Marennes-Oléron". Thesis, La Rochelle, 2010. http://www.theses.fr/2010LAROS294.
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L’importance des compartiments microbiens dans le fonctionnement trophique et biogéochimique des écosystèmes marins a amené à nous poser les objectifs suivants : caractérisation des virus, des bactéries et des flagellés et de leurs interactions dans le bassin de Marennes Oléron. Différentes approches ont été suivies : 1) une approche in situ avec des suivis mensuels (2006 et 2007) a permis de caractériser les dynamiques des compartiments microbiens et situer leur place dans le fonctionnement général du bassin en comparaison avec celui d’Arcachon. La succession des modes de fonctionnement trophique suggère l’importance du réseau microbien dans ces bassins. A Marennes, spatialement homogène, le lien établi entre le bactérioplancton et le virioplancton varie selon une échelle interannuelle et saisonnière modulé par un lien ponctuel entre les virus avec le phytoplancton. 2) une approche in vitro a permis de cibler les processus régissant les dynamiques des virus, des flagellés et de bactéries ainsi que leurs interactions. Les impacts de la bactériolyse virale et de la bactérivorie ont été étudiés suivant différents facteurs de variabilité : périodes trophiques, pression de prédation et influence d’apports benthiques. De manière générale, la composition des communautés bactériennes, par la sensibilité de certains groupes, est influencée par la lyse virale et la bactérivorie. La production bactérienne, elle, varie suivant le mode trophique, stimulée en période de type herbivore par la présence des flagellés alors qu’en période de multivorie ils entrainent une perte d’au moins 16% de la production quotidienne. Enfin, la remise en suspension du biofilm benthique lors d’une phase de marée tend à stimuler l’activité globale de la boucle microbiennePlanktonic microbial compartments are important in the trophic and biogeochemical functioning of marine ecosystems. This assessment brought us to place these objectives: characterization of virus, bacteria and flagellate compartments and their interactions in Marennes-Oléron Bay (France). Two different approaches have been followed: 1) In situ annual surveys were performed in 2006 and 2007 in order to characterize microbial compartments dynamics and to place them within the bay functioning, compared to Arcachon Bay. The succession of trophic models implied the importance of the microbial food web in both bays. In Marennes Oléron Bay, spatially homogeneous, large inter annual and inter seasonal variations are observed considering the strength of the common link between virioplankton and bacterioplankton. These variations are related to the occurrence of an occasional interaction of phytoplankton. 2) In vitro experiments allow to focus on the processes controlling the dynamics of viruses, flagellates and bacteria and their interactions. The impacts of viral bacteriolysis and flagellate bacterivory are assessed considering environmental variability factors: trophic models, predation pressure and influence of benthic contribution. The bacterial community composition is always influenced by viral lysis and bacterivory due to the sensitivity of bacterial groups. However, bacterial cellular production evolves differently with a stimulation by flagellates during herbivorous food web while bacterivory induces daily production loss of 16% during multivorous food web. Finally, the resuspension of benthic organic components during tide phase tends to increase the microbial loop activity
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Lee, Sungeun. "Virus-host interactions across a soil pH gradient at the community and individual scale". Thesis, Lyon, 2020. http://www.theses.fr/2020LYSEC020.
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Les virus du sol sont capables d'influencer la structure de la communauté microbienne et le fonctionnement de l'écosystème en affectant l'abondance des cellules hôtes par lyse et par leurs caractéristiques à transférer des gènes entre les hôtes. Bien que notre compréhension sur la diversité et la fonction virales s’améliore, la connaissance des interactions hôte-virus dans le sol reste limitée. Pour mieux comprendre les interactions hôte-virus, un gradient du sol à long terme manipulé par le pH dans lequel la communauté microbienne change à travers, a été étudié. Les principaux objectifs de cette thèse ont consisté à (1) déterminer l'influence de la structure de la communauté microbienne et du pH du soil sur les virus par séquençage d’ADN haut-débit (Chapitre II), (2) déterminer l’infectivité des populations virales à partir de niches de sol co-localisées et non co-localisées avec son hôte grâce à une approche de l’essai de plaque combinée à un séquençage hybride (Chapitre III), (3) identifier les populations virales infectant des groupes fonctionnels microbiens spécifiques du sol, en particulier les méthanotrophes (Chapitre IV) et les nitrifiants (Chapitre V ), à l’aide d’une sonde isotopique stable à l'ADN. Nos premiers résultats ont montré que la structure de la communauté virale change selon le pH du sol, ce qui souligne que la communauté virale est étroitement liée aux populations hôtes. L’analyse de CRISPR systèmes a révélé des interactions virus-hôte dynamiques, avec le nombre et la taille des CRISPR systèmes distincts selon le soil à pH contrasté. L’analyse taxonomique de cette CRISPR systèmes suggère que les virus jouent un rôle essentiel dans la composition et de la fonction de la communauté procaryote du sol. Les processus co-évolutionnaires entre l'hôte (le système de restriction-modification et le CRISPR-Cas système) et les populations virales co-localisées (la mutation d’une séquence espaceur « spacer » et la méthyltransférase codée par le virus) fournissent des preuves de l'adaptation locale et que les interactions virus-hôte jouent un rôle important dans la susceptibilité d'un hôte à l'infection et par conséquent la régulation des populations bactériennes du sol. L'ADN-SIP-métagénomique ciblant des groupes fonctionnels microbiens spécifiques a permis l’analyse des populations hôte-virus individuelles. Le suivi du flux de carbone à travers les populations procaryotes et virales a révélé des interactions actives entre les virus et les hôtes méthanotrophes et nitrifiants, et les préférences de niches de pH du sol. Notre étude a montré une preuve de transfert horizontal de gènes et des gènes métaboliques auxiliaires codés par le virus, indiquant que les virus contribuent de manière significative aux cycles biogéochimiques dans le sol, tels que le carbone (les gènes qui codent pour les familles GH, peptidases et la sous-unité C de méthane monooxygénase particulaire), et l'azote (les gènes qui codent pour la nitrogénase et le cytochrome cd1-nitrite réductase). Dans l’ensemble, ces résultats ont montré que les virus du sol sont des régulateurs importants des communautés microbiennes par la lyse spécifique de l’hôte et des interactions dynamiques virus-hôteSoil viruses have potential to influence microbial community structure and subsequent ecosystem functioning by directly affecting the abundance of host cells by lysis and through their ability to transfer genes between hosts. Although our understanding of soil viral diversity and functioning has increased, the role of viruses and their interactions with prokaryotes in soil is limited. To gain a better understanding of virus-host interactions in soil, a long-term pH-manipulated soil gradient, which microbial community structure changes across, was investigated. The main objectives of this thesis were to 1) determine the influence of microbial community structure and soil pH on viruses using metagenomics and viromics (Chapter II), 2) determine the infectivity of soil viral populations from co-localized and foreign pH soil niches using a plaque assay approach combined with hybrid metagenomics sequencing (Chapter III) and 3) identify virus populations infecting specific soil microbial functional groups, specifically methanotrophs (Chapter IV) and nitrifiers (Chapter V), using DNA stable isotope probing combined with metagenomic deep sequencing. Viral community structure was found to change with soil pH, demonstrating that viral communities are tightly linked to host populations, but also may have narrow host ranges. Analysis of clustered regularly interspaced short palindromic repeats (CRISPR) arrays revealed dynamic virus-host interactions, with the number and size of CRISPR arrays distinct across contrasting pH soil. Profiling of the host-virus linkages between soil pH, suggests that viruses play a critical role in shaping the composition and function of the soil prokaryotic community. Surprisingly, greater infectivity of a host bacterium by virus populations was found when viruses and host bacterium were not co-localized in the same pH soil. Coevolutionary processes between the host and virus populations, such as restriction modification/virus-encoded methyltransferase and CRISPR-Cas system/spacer mutation, provide evidence for local adaptation, and that virus-bacterial host interactions play an integral part in the susceptibility of a host to infection and consequently in the regulation of soil bacterial populations. Targeting specific microbial functional groups via stable isotope probing allowed analysis of individual host-virus populations. Tracking carbon flow through prokaryotic and viral populations revealed active interactions between viruses and methanotroph and nitrifier hosts, and soil pH niche preferences. Evidence of horizontal gene transfer and virus-encoded auxiliary metabolic genes, such as glycoside hydrolase families, peptidases, particulate methane monooxygenase subunit C (pmoC), nitrogenase (nifH) and cytochrome cd1-nitrite reductase, supports that viruses are significant contributors to host functioning and carbon and nitrogen cycling in soil. Overall, this work demonstrated that soil viruses are important regulators of microbial communities through specific host lysis and dynamic virus-host interactions
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Dauthuille, Dominique. "Etude écopathologique de deux baculovirus pathogènes de Spodoptera Frugiperda (J. E. Smith) (lépidoptère : noctuidae) en prairie guyanaise à Digitaria Swazilandensis Stent". Paris 6, 1986. http://www.theses.fr/1986PA066484.
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Deux baculovirus, une granulose et une polyédrose nucléaire, isolés de S. F. En Guyane française sont décrits. Les deux maladies sont responsables d'enzooties dans les populations du ravageur en prairie à d. S. La valeur maximale de la mortalité larvaire naturelle engendrée par les deux virus, déterminée après échantillonnage et élevage au laboratoire, est de 32%. La cyclicité de la présence sur une même parcelle de la noctuelle et de ses baculovirus est due au mode de conduite des exploitations agricoles. Les taux de mortalité larvaire par granulose et par polyédrose nucléaire sont variables d'une parcelle à une autre, et un équilibre dynamique se maintient entre les deux viroses. L'introduction d'un mélange des deux virus a permis de montrer que les larves jouent un rôle important dans la dissémination des pathogènes dans la prairie.
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Mocaër, Pierre-Yves. "From gene to ecosystem : an integrative study of polysaccharide depolymerases bound to marine viruses". Thesis, Sorbonne université, 2019. http://www.theses.fr/2019SORUS553.
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Les virus constituent une force motrice pour le fonctionnement des écosystèmes marins. En tuant leur hôte par lyse cellulaire, ils influencent la diversité microbienne et les cycles biogéochimiques globaux. Dans cette étude, je me suis intéressé à l’implication des polysaccharide dépolymérases (ou EPS dépolymérases) associées aux virus de bactéries (phages) dans la régulation des activités virales et leurs conséquences sur la biogéochimie océanique. Ces enzymes confèrent aux phages la faculté de dégrader les exopolysaccharides (EPS) excrétés par leurs hôtes avant d’atteindre leurs récepteurs membranaires. Nous avons étudié de façon intégrative, du gène à l’écosystème, les EPS dépolymérases associées à 2 phages modèles (Podoviridae). Une combinaison d’approches a révélé que les gènes codant pour ces activités sont génétiquement éloignés des séquences connues. Une étude approfondie de l’une de ces enzymes (Dpo31, associée au phage de Cobetia marina) suggère son appartenance aux glycoside hydrolases et révèle une architecture moléculaire nouvelle. De plus, une expérience en microcosme a montré que les dépolymérases virales réduisent la biodisponibilité des EPS et participent à la production de matière réfractaire dans le milieu naturel. Compte tenu de la prédominance des virus dans l’océan, ce processus jusqu'ici négligé pourrait avoir des implications biogéochimiques importantesViruses represent a driving force for the functioning and evolution of marine ecosystems. Through the lysis of their hosts, viruses profoundly influence the diversity and biogeochemistry of the ocean. In this study, I investigated the implications of polysaccharide depolymerases (or EPS depolymerases) associated to bacterial viruses (phages) in the regulation of viral activities and their consequences on ocean biogeochemistry. They confer to phages the ability to degrade the exopolysaccharides (EPS) excreted by their hosts in order to access their membrane receptors. Here, we studied integratively, from gene to ecosystem, the EPS depolymerases associated to 2 model phages (Podoviridae). A combination of approaches revealed that the genes encoding these activities are genetically distant from known sequences. An in-depth study showed that the enzyme Dpo31 (associated to Cobetia marina phage) is a glycoside hydrolases and revealed a novel molecular architecture. In the ocean, bacterial EPS constitute a significant pool of dissolved organic carbon. A microcosm experiment showed that viral depolymerases reduce the bioavailability of EPS and contribute to the production of refractory matter in the natural environment. Considering the predominance of viruses in the sea, this, so far, neglected process could have important implications for the functioning of the ocean
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"Impact of Viral Infectivity on Phototrophic Microbes for Biofuel Applications". Master's thesis, 2014. http://hdl.handle.net/2286/R.I.27539.
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abstract: Research in microbial biofuels has dramatically increased over the last decade. The bulk of this research has focused on increasing the production yields of cyanobacteria and algal cells and improving extraction processes. However, there has been little to no research on the potential impact of viruses on the yields of these phototrophic microbes for biofuel production. Viruses have the potential to significantly reduce microbial populations and limit their growth rates. It is therefore important to understand how viruses affect phototrophic microbes and the prevalence of these viruses in the environment. For this study, phototrophic microbes were grown in glass bioreactors, under continuous light and aeration. Detection and quantification of viruses of both environmental and laboratory microbial strains were measured through the use of a plaque assay. Plates were incubated at 25º C under continuous direct florescent light. Several environmental samples were taken from Tempe Town Lake (Tempe, AZ) and all the samples tested positive for viruses. Virus free phototrophic microbes were obtained from plaque assay plates by using a sterile loop to scoop up a virus free portion of the microbial lawn and transferred into a new bioreactor. Isolated cells were confirmed virus free through subsequent plaque assays. Viruses were detected from the bench scale bioreactors of Cyanobacteria Synechocystis PCC 6803 and the environmental samples. Viruses were consistently present through subsequent passage in fresh cultures; demonstrating viral contamination can be a chronic problem. In addition TEM was performed to examine presence or viral attachment to cyanobacterial cells and to characterize viral particles morphology. Electron micrographs obtained confirmed viral attachment and that the viruses detected were all of a similar size and shape. Particle sizes were measured to be approximately 50-60 nm. Cell reduction was observed as a decrease in optical density, with a transition from a dark green to a yellow green color for the cultures. Phototrophic microbial viruses were demonstrated to persist in the natural environment and to cause a reduction in algal populations in the bioreactors. Therefore it is likely that viruses could have a significant impact on microbial biofuel production by limiting the yields of production ponds.Dissertation/Thesis
Masters Thesis Civil and Environmental Engineering 2014
Libros sobre el tema "Virus de microbes"
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Zimmerman, Barry E. Killer germs: Microbes and diseases that threaten humanity. Chicago, Ill: Contemporary Books, 1996.
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A, Oldstone Michael B., ed. Molecular mimicry: Cross-reactivity between microbes and host proteins as a cause of autoimmunity. Berlin: Springer-Verlag, 1989.
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Krasner, Robert I. 20th century microbe hunters. Sudbury, MA: Jones and Bartlett Publishers, 2008.
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Zimmer, Carl, 1966- writer of introductory text, ed. Virus: An illustrated guide to 101 incredible microbes. Princeton University Press, 2016.
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Zimmer, Carl. Virus: An Illustrated Guide to 101 Incredible Microbes. Princeton University Press, 2016.
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Roossinck, Marilyn. Virus: 101 Incredible Microbes from Coronavirus to Zika. Ivy Press, The, 2025.
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Roossinck, Marilyn. Virus: An Illustrated Guide to 100 Incredible Microbes. Ivy Press, The, 2016.
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Harper, D. R. Of Mice, Men and Microbes. SPCK Publishing, 1999.
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Oliveira, Ana, Carlos São-José, Diana Priscila Penso Pires, Hugo Alexandre Mendes Oliveira, Ivone M. Martins, Joana Azeredo, Krystyna Dabrowska et al., eds. Viruses of Microbes: the latest conquests. CEB UMinho, 2022. http://dx.doi.org/10.21814/1822.79403.
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This book covers abstracts from the most recent advances in ecology and evolution of microbial viruses, virus structures and function, virus-host interaction, agro-food, veterinary and environmental biotechnology applications and phage therapy.
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Harper, D. R. y Andrea S. Meyer. Of Mice, Men, and Microbes: Hantavirus. Elsevier Science & Technology Books, 1999.
Buscar texto completoCapítulos de libros sobre el tema "Virus de microbes"
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Wick, Charles H. "Microbes, Fungi, Bacteria, and Viruses". En Virus Detection, 21–32. Boca Raton: CRC Press, 2023. http://dx.doi.org/10.1201/9781003106623-2.
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Peters, C. J. "Experiences of a Virus Hunter". En Many Faces, Many Microbes, 146–57. Washington, DC, USA: ASM Press, 2014. http://dx.doi.org/10.1128/9781555818128.ch19.
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Johnson, Welkin. "Virus in the Room". En In the Company of Microbes, 24–26. Washington, DC, USA: ASM Press, 2016. http://dx.doi.org/10.1128/9781555819606.ch8.
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Fuhrman, Jed A. y David A. Caron. "Heterotrophic Planktonic Microbes: Virus, Bacteria, Archaea, and Protozoa". En Manual of Environmental Microbiology, 4.2.2–1–4.2.2–34. Washington, DC, USA: ASM Press, 2015. http://dx.doi.org/10.1128/9781555818821.ch4.2.2.
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Jackson, Trevor A. "The Use of Oryctes Virus for Control of Rhinoceros Beetle in the Pacific Islands". En Use of Microbes for Control and Eradication of Invasive Arthropods, 133–40. Dordrecht: Springer Netherlands, 2009. http://dx.doi.org/10.1007/978-1-4020-8560-4_8.
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Jin, Min, Tianliang He y Xiaobo Zhang. "Marine Microbe Stress Responses to Bacteriophage Infection". En Virus Infection and Tumorigenesis, 141–74. Singapore: Springer Singapore, 2019. http://dx.doi.org/10.1007/978-981-13-6198-2_5.
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Xu, Chenxi, Min Jin y Xiaobo Zhang. "Roles of Microbial Metabolites in Bacteriophage-Microbe Interactions". En Virus Infection and Tumorigenesis, 175–207. Singapore: Springer Singapore, 2019. http://dx.doi.org/10.1007/978-981-13-6198-2_6.
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He, Tianliang, Chenxi Xu y Xiaobo Zhang. "Antitumor Activities of Secondary Metabolites from Marine Microbe Stress Responses to Virus Infection". En Virus Infection and Tumorigenesis, 285–318. Singapore: Springer Singapore, 2019. http://dx.doi.org/10.1007/978-981-13-6198-2_9.
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Baker, Barbara, S. P. Dinesh-Kumar, Doil Choi, Reinhard Hehl, Catherine Corr y Steve Whitham. "Isolation of the Tobacco Mosaic Virus Resistance Gene N". En Advances in Molecular Genetics of Plant-Microbe Interactions, 297–302. Dordrecht: Springer Netherlands, 1994. http://dx.doi.org/10.1007/978-94-011-0177-6_43.
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Nuss, Donald L., Baoshan Chen y Gil H. Choi. "Recent Advances in Expanding and Understanding Virus-Mediated Attenuation of Fungal Virulence". En Advances in Molecular Genetics of Plant-Microbe Interactions, 387–93. Dordrecht: Springer Netherlands, 1994. http://dx.doi.org/10.1007/978-94-011-0177-6_58.
Texto completoActas de conferencias sobre el tema "Virus de microbes"
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Maqueda, M., N. Rodriguez-Cousiño, R. Esteban, E. Zamora y M. Ramírez. "Characterization of a new Saccharomyces cerevisiae dsRNA virus encoding a killer toxin with broad antifungal activity". En MICROBES IN APPLIED RESEARCH - Current Advances and Challenges. WORLD SCIENTIFIC, 2012. http://dx.doi.org/10.1142/9789814405041_0123.
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Tsygichko, A. A., A. M. Asaturova, M. D. Pavlova y N. S. Tomashevich. "Insecticidal properties of strains of the granulosa virus of the codling moth from the Bioresource collection of FSBI VNIIBZR". En 2nd International Scientific Conference "Plants and Microbes: the Future of Biotechnology". PLAMIC2020 Organizing committee, 2020. http://dx.doi.org/10.28983/plamic2020.259.
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The insecticidal activity of strains from DBK of the Federal State Budget Scientific Institution VNIIBZR “State Collection of Entomoacarifagi and Microorganisms” was studied with respect to the test object Galleria mellonella L. and with respect to the target insect Cydia pomonella L. It was revealed that strain BZR 14 is promising for further study and development of a laboratory sample based on it.
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Pascu, Corina, Viorel Herman, Sara Gatto y Luminita Costinar. "RETROSPECTIVE STUDY OF WEST NILE VIRUS IN ITALY". En 10th SWS International Scientific Conferences on SOCIAL SCIENCES - ISCSS 2023. SGEM WORLD SCIENCE, 2023. http://dx.doi.org/10.35603/sws.iscss.2023/sv07.31.
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The infectious diseases are mainly the consequence of the existence of the microbialworld, essential for life on our planet. Microbes need a superior animal to multiply andspread to survive. The pathogens are therefore the biological agents responsible for theonset of the disease condition in the host organism. The infectious disease appears to bethe consequence of the interaction between pathogens and specific defense systems,immune response, and nonspecific (inflammation) of the host.West Nile virus (WNV) belongs to the family Flaviviridae and implies the West Nilefever (WNF) a vector-borne disease caused by the group of Arboviruses. The termArbovirus is the acronym for arthropod-borne viruses.Vector-borne diseases are human illnesses caused by parasites, viruses, and bacteria thatare transmitted by vectors, for instance, bloodsucking insects, that can transmitinfectious pathogens between humans or from animals to humans. Mosquitoes typicallyspread WNF. Arboviruses can be found in nature without including man in their cycle,they only infect them accidentally, but the scientific community focuses great attentionand importance on these diseases.In this study, we analyzed the dynamics of the spread WNV in Italy between 2009 and2019 focusing on the virus life cycle which is more likely to be re-activated each yearvia previously infected mosquitoes in some specific regions, especially in northern Italywhere its spread has been observed since 2008. For example, Veneto is one of theItalian regions where WNV is considered endemic, and the greatest intensity ofcirculation was observed, particularly in August.It first analyzed the causes of the disease spreading, underlying the distribution, thefrequency of the re-activations in some peculiar regions, and the determinants, forinstance, the risk factors, of health-related states and events in Italy throughout a periodof ten years.
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Ichikawa, Akihiko, Ayae Honda, Miho Ejima, Tamio Tanikawa, Fumihito Arai y Toshio Fukuda. "In-situ formation of a gel microbead for laser micromanipulation of microorganisms, DNA and virus". En 2006 IEEE International Symposium on Micro-NanoMechatronics and Human Science. IEEE, 2006. http://dx.doi.org/10.1109/mhs.2006.320222.
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Takatsuka, Shuhei, Takeshi Kubota, Yuta Kurashina y Hiroaki Onoe. "Near Infrared-Triggered On-Demand Adeno-Associated Virus Release From Hydrogel Microbeads For Gene Therapy". En 2022 IEEE 35th International Conference on Micro Electro Mechanical Systems Conference (MEMS). IEEE, 2022. http://dx.doi.org/10.1109/mems51670.2022.9699702.
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Song, Minghao y Hongwei Sun. "Microfluidics Based Impinger for Air Sampling". En ASME 2012 10th International Conference on Nanochannels, Microchannels, and Minichannels collocated with the ASME 2012 Heat Transfer Summer Conference and the ASME 2012 Fluids Engineering Division Summer Meeting. American Society of Mechanical Engineers, 2012. http://dx.doi.org/10.1115/icnmm2012-73230.
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Capturing particles from the air into the liquid is critical for the development of analysis systems for bio-particles such as virus, toxins and spores. We report a miniaturized airborne particle sampling (collection) device that relies on a bubbling process formed in a small chamber where air (to be sampled) is flown through a microchannel array into the liquid in the chamber. The airborne particles trapped in the tiny bubbles (diameter: 80 microns) are diffused into liquid and captured into the liquid and analyzed. The whole device is fabricated on a glass slide using soft-lithography method with Polydimethylsiloxane (PDMS) as the structural material. To prevent the air leakage at the connections, a special sealing process depending on PDMS only without the use of any glue was successfully developed. Hydrophobicity of channel surface was found to be critical for generating continuous and stable bubble lines in the bubbling process. The collection efficiency is measured by collecting polystyrene latex particles (diameter: ∼1 micron) on polycarbonate membrane filters at the inlet and outlet of the device. It was found that a collection efficiency of 90% from the microfluidics based impinger is achieved, which is much higher than that of conventional impinger device. Furthermore, a collection time of 10 minutes is needed for this device compared to a few hours for a conventional impinger.
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Camacho, Javier, Isis Bonet, Gisela De la Rosa y Jeisson Barrera. "Modelo predictivo para el pronóstico temprano de gravedad en pacientes con diagnóstico de neumonía en unidades de cuidado intensivo". En Ingeniería para transformar territorios. Asociación Colombiana de Facultades de Ingeniería - ACOFI, 2023. http://dx.doi.org/10.26507/paper.2895.
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La neumonía es considerada como una infección pulmonar causada por múltiples microorganismos (bacterias, virus u hongos), clasificada en dos tipos según se adquiera, que son; neumonía adquirida por la comunidad (extrahospitalaria), donde generalmente su fuente es una bacteria llamada neumococo y la neumonía hospitalaria (intrahospitalaria), donde su origen son los centros hospitalarios, con bacterias poco comunes en la comunidad. La neumonía se ha identificado como la infección intrahospitalaria más común, con una prevalencia de 26%, donde el 35% de los casos hacen referencia a neumonía asociada al ventilador. Neumonía intrahospitalaria puede ser mortal, debido a que los pacientes que la contraen ya se encuentran hospitalizados por lo que ya están enfermos y su sistema inmune no puede combatir los microbios. Esta infección ataca al sistema respiratorio del paciente, por lo que en la mayoría de los casos es necesario conectar al paciente a un ventilador mecánico o ingresarlo a la unidad de cuidados intensivos (UCI). Una vez el paciente se encuentra hospitalizado en UCI, su condición de salud es inestable y delicada por lo que es muy importante vigilarlo continuamente y evitar desenlaces mortales. Mediante este proyecto se pretende desarrollar un modelo que permita generar un pronóstico temprano de la gravedad de los pacientes diagnosticados con neumonía en UCI, ofreciendo una herramienta que le permita al personal asistencial agilizar los tratamientos en aquellos pacientes más críticos e incluso salvarles la vida. Para el diseño del modelo se utilizaron técnicas de inteligencia artificial basadas en la última generación de árboles de decisión (Light Gradient Boosting Machine), utilizando como base de conocimiento bases de datos anonimizadas de las UCI de una institución de salud norteamericana (MIMIC III) y potencial aplicación a un Hospital de tercer nivel de la ciudad de Medellín.
Informes sobre el tema "Virus de microbes"
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Avni, Adi y Kirankumar S. Mysore. Functional Genomics Approach to Identify Signaling Components Involved in Defense Responses Induced by the Ethylene Inducing Xyalanase Elicitor. United States Department of Agriculture, diciembre de 2009. http://dx.doi.org/10.32747/2009.7697100.bard.
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Plant-microbe interactions involve a large number of global regulatory systems, which are essential for plants to protect themselves against pathogen attack. An ethylene-inducing xylanase (EIX) of Trichoderma viride is a potent elicitor of plant defense responses, like hypersensitive response (HR), in specific cultivars of tobacco (Nicotiana tabacum) and tomato (Lycopersicon esculentum). The central goal of this proposal was to investigate the molecular mechanisms that allow plants to specifically activate defense responses after EIX treatment. We proposed to identify cellular signaling components involved in the induction of HR by the EIX elicitor. The molecular genetic analysis of the signal transduction pathway that modulates hypersensitive responses is an important step in understanding the induction of plant defense responses. The genes that mediate LeEIX2-EIX dependent activation of resistance mechanisms remain to be identified. We used two approaches to identify the cellular signaling components that induce HR mediated by the EIX elicitor. In the first approach, we performed a yeast two-hybrid screening using LeEix2 as bait to identify plant proteins that interact with it. In the second approach, we used virus-induced gene silencing (VIGS) for a high-throughput screen to identify genes that are required for the induction of LeEIX2-EIX mediated HR. VIGS will also be used for functional characterization of genes that will be identified during the yeast two-hybrid screen. This investigation will shed light on cellular processes and signaling components involved in induction of general plant defense against pathogens and will provide the basis for future biotechnological approaches to improve plant resistance to pathogens. Several genes were indentified by the two approaches. We used the VIGS and yeast two hybrid approaches to confirm that activity of the genes initially identified by different procedure. Two genes inhibit the induction of HR by the fungal elicitor in the different systems; Tobacco-Harpin binding protein 1 and cyclopropyl isomerase.