Siga este link para ver outros tipos de publicações sobre o tema: Microbiologly.
Teses / dissertações sobre o tema "Microbiologly"
Crie uma referência precisa em APA, MLA, Chicago, Harvard, e outros estilos
Veja os 50 melhores trabalhos (teses / dissertações) para estudos sobre o assunto "Microbiologly".
Ao lado de cada fonte na lista de referências, há um botão "Adicionar à bibliografia". Clique e geraremos automaticamente a citação bibliográfica do trabalho escolhido no estilo de citação de que você precisa: APA, MLA, Harvard, Chicago, Vancouver, etc.
Você também pode baixar o texto completo da publicação científica em formato .pdf e ler o resumo do trabalho online se estiver presente nos metadados.
Veja as teses / dissertações das mais diversas áreas científicas e compile uma bibliografia correta.
1
Lombard, Bertrand. "Les essais inter-laboratoires en microbiologie des aliments Inter-laboratory studies in food microbiology". Phd thesis, INAPG (AgroParisTech), 2004. http://pastel.archives-ouvertes.fr/pastel-00001258.
Texto completo da fonteResumo:
La validité des contrôles microbiologiques, réalisés dans l'objectif d'assurer la sécurité sanitaire des aliments, nécessite notamment l'obtention de résultats d'analyse fiables. La fiabilité des résultats implique l'utilisation de méthodes validées, mises en œuvre par un laboratoire compétent. Les essais inter-laboratoires permettent de s'assurer, du moins en partie, du respect de ces deux conditions. Cependant, en raison de limites expérimentales, ces essais ne sont pas aussi largement pratiqués dans le domaine de la microbiologie des aliments qu'ils ne le sont dans d'autres domaines analytiques. Dans un premier temps, une revue des documents de référence permet d'établir un état des lieux. Cette revue concerne les trois objectifs que l'on peut assigner à des essais interlaboratoires, à savoir l'évaluation de méthodes d'analyse, celle des laboratoires, et la caractérisation de matériaux de référence. Les documents de portée générale, puis ceux spécifiques de l'analyse des aliments, sont pris en compte, et leur degré d'applicabilité à l'analyse microbiologique des aliments est envisagé. Les référentiels et pratiques propres au domaine d'intérêt traité sont finalement présentés, et les déviations par rapport aux documents généraux analysées. Sur cette base, sont présentées les conditions de mise en œuvre de deux types d'essais interlaboratoires, soit la validation de méthodes dans le cadre d'un projet européen du 4ème Programme Cadre de Recherche & Développement d'une part, et l'évaluation de laboratoires par le biais d'essais d'aptitude pour les Laboratoires Nationaux de Référence sur le lait d'autre part. Les difficultés relatives au protocole expérimental, et liées aux spécificités de la microbiologie, sont mises en exergue. Les modes d'exploitation des résultats, en fonction des objectifs et de la nature, qualitative ou quantitative, de la détermination, sont expliqués. En ce qui concerne la caractérisation de la performance des méthodes d'analyse, l'utilisation de statistiques robustes pour estimer la fidélité des méthodes quantitatives est discutée, ainsi que la façon de caractériser la fidélité comme la justesse des méthodes qualitatives. Sur ces aspects, des perspectives d'amélioration sont envisagées. L'intérêt de l'organisation des essais inter-laboratoires en microbiologie des aliments est ensuite abordé. Celui-ci réside dans l'utilisation que l'on peut faire de ces essais comme éléments incontournables de validation d'une méthode d'analyse et d'évaluation d'un laboratoire afin, d'une part, de crédibiliser ou d'améliorer les méthodes d'analyse normalisées au niveau international, et d'autre part d'estimer l'incertitude de mesure attachée aux résultats d'analyse. Quant aux limites de ces essais, essentiellement d'ordre expérimental, elles tiennent surtout à la nature vivante de l'analyte, et concernent des questions de représentativité.
2
Keltjens, Herman Michiel Antonius Marie. "Microbiology and preventive treatment of root surface caries Microbiologie en preventieve behandeling van tandwortelcariës /". Helden-Panningen : De Gouden Leeuv Drukkerij B.V, 1988. http://catalog.hathitrust.org/api/volumes/oclc/19650028.html.
Texto completo da fonteResumo:
Thesis (doctoral)--Katholieke Universiteit te Nijmegen, 1988.Text in English with a summary in Dutch. "Een wetenschappelijke proeve op het gebied van geneeskunde en tandheelkunde." Includes bibliographical references.
3
Badia, Palacín Josefa. "Clonación y caracterización del operon de la ramnosa de Escherichia coli". Doctoral thesis, Universitat de Barcelona, 1987. http://hdl.handle.net/10803/672820.
Texto completo da fonteResumo:
La L-fucosa y la L-ramnosa son dos azúcares naturales que E.coli es capaz de utilizar como fuente de carbono y energía. La diferencia estructrural entre la ramnosa (6- deoxi - manosa) y la fucosa (6-deoxi-galactosa) está unicamente en la posición del radical hidroxilo del c2 y c4.
La L-fucosa se metaboliza a través de la acción secuencial de una serie de enzimas inducibles: la fucosa permeasa, la fucosa isomerasa, la fuculosa quinasa y la fuculosa-1-fosfato aldolasa. Por su parte, la ramnosa se metaboliza por una vía análoga a la descrita para la glucosa por acción secuencial de una serie de enzimas inducibles: la ramnosa permeasa, ramnosa isomerasa y la ramnulosa quinasa) y la ramnulosa-1-fosfato aldolasa. Las vías convergen en un punto, de modo que lo descrito para fucosa es válido para glucosa.
Se ha de destacar que, si bien existe una gran analogía entre las reacciones implicadas en el catabolismo de la fucosa y de la ramnosa, los enzimas que participan son altamente específicos para cada vía, así como su inducción. También la localización cromosómica de los genes en ambos sistemas es totalmente diferente. Por tanto, a pesar de la gran similitud estructural entre la fucosa y la ramnosa, así como entre sus vías de degradación, los sistemas “fue” y “rha” se comportan de forma diferente por lo que respecta a los cuatro primeros enzimas de la vía metabólica, de manera que ambos dos sistemas parecen tener una organización genética diferente.
4
Bridson, Eric Youlden. "Quantal microbiology". Thesis, University of Bristol, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.312059.
Texto completo da fonte
5
Osman, Shaiesta. "Oral microbiology". Thesis, University of North Texas, 1998. http://catalog.hathitrust.org/api/volumes/oclc/48128254.html.
Texto completo da fonte
6
Vera, Garcia Rodrigo Elizardo. "Microbiología del caracol Helix aspersa Müller. Aplicaciones biotecnológicas para su mejoramiento sanitario con impacto en su comercialización". Doctoral thesis, Universitat Autònoma de Barcelona, 2016. http://hdl.handle.net/10803/399849.
Texto completo da fonteResumo:
La Helicicultura se define como la cría a ciclo biológico completo de caracoles. El caracol terrestre Helix aspersa Müller es el más utilizados en distintas regiones europeas como alimento, que destaca por su alta prolificidad y capacidad de adaptación al ambiente. La cría de caracoles es una actividad ganadera, y no está exenta de la manifestación de procesos patológicos de origen microbiológico que ocasionan pérdidas productivas. Actualmente, la Helicicultura tiene por objetivo la comercialización de un caracol de calidad, sometido a rigurosos controles sanitarios y zootécnicos para garantizar su inocuidad y seguridad como alimento.
Los objetivos de esta Tesis doctoral son lograr optimizar y/o generar metodologías que faciliten la correcta administración de la cepa probiótica Lactobacillus plantarum Ca7, aislada desde caracoles, y que contribuyan a mejorar el estado sanitario de granjas destinadas a cría y engorde del caracol terrestre Helix aspersa Müller.
Los resultados obtenidos indican que, la contaminación presente en una nave destinada a la reproducción de caracoles, está relacionada con los microorganismos existentes en la microbiota intestinal de los animales, principalmente los de la familia Enterobacteriaceae, y que la microbiota se modifica si consume pienso contaminado. Los estudios sobre L. plantarum Ca7 indicaron que modificaciones en el medio de cultivo MRS, parámetros de incubación, y aquellos involucrados en el proceso de liofilización, permiten mejorar la producción de la biomasa, incrementar la concentración de la cepa liofilizada, y establecer las óptimas condiciones de almacenamiento de los cultivos liofilizados. Para el uso de un sistema en agitación que incorpora un cultivo de L. plantarum Ca7 para administrar a los caracoles a través del agua de riego, es preferible partir de cultivos no liofilizados y mezclarlos con agua de pozo para asegurar la sobrevivencia de la cepa y la inocuidad del preparado durante la hidratación de los caracoles. En relación al uso del sobrenadante de la cepa, se observó que posee propiedades inhibitorias sobre el desarrollo de microorganismos patógenos y sobre la formación de biopelículas de Staphylococcus aureus, además si esta fracción es liofilizada, aumentan sus propiedades inhibitorias, destacando el efecto sobre Pseudomonas aeruginosa. Este sobrenadante es posible incorporarlo al pienso de forma liofilizada sin que pierda sus propiedades inhibitorias. En laboratorio, tras la administración a caracoles de distinta edad de pienso enriquecido con L. plantarum Ca7, los resultados indicaron que este alimento modifica la microbiota, previene la mortalidad de los caracoles, y mejora la calidad microbiológica del pienso.
En base a estos resultados podemos indicar que la administración a caracoles de L. plantarum Ca7 y el uso de su sobrenadante para el control de microorganismos contaminantes presentes en la Helicicultura, serían capaces de ayudar a mejorar sanitariamente esta actividad ganadera, a través de la prevención de patologías de origen microbiano, modificación de la microbiota intestinal, y mejora de la calidad microbiológica del pienso. Efectos que conllevan a una mejora productiva durante la crianza del caracol, y entregan un valor agregado al producto final, con consecuente impacto en su comercialización.The Heliciculture is defined as the full life cycle breeding of snails. The land snail Helix aspersa Müller is the most used in different European regions as food, and it stand up for its high prolificacy and adaptability to the environment capacity. The breeding of snails is a livestock activity, and is not exempt from the manifestation of pathological processes of microbiological origin, that cause production losses. Currently, the Heliciculture aims at the marketing of quality snail, subjected to strict health and zootechnical controls to ensure the safety of this food. The objectives of this thesis are to optimize and/or create methodologies that facilitate the correct administration of the probiotic Lactobacillus plantarum Ca7 strain, which contributes to improve the health status of farms, intended for breeding and fattening land snail Helix aspersa Müller. The obtained results indicated that, the contamination present on a farm dedicated to snail reproduction, is associated with the microorganism in the intestinal microbiota of animals, mainly the Enterobacteriaceae Family, and the microbiota change because of contaminated feed consumption. The L. plantarum Ca7 studies, indicated that changes in the MRS culture medium, incubation parameters, and those involved in the lyophilization process, allow the improvement of the biomass production, increase of the lyophilized strain concentration, and the establishment of optimal storage conditions of freeze-dried cultures. For the use of an agitation system incorporating a culture of L. plantarum Ca7 to manage snails through irrigation water, it’s better to start whit no-lyophilized cultures, mixed with well water to ensure the survival of the strain and the safety of the preparation during the snails hydration. Concerning the use of the strain supernatant, observation showed that it possesses inhibitory properties on growth of pathogenic microorganisms and Staphylococcus aureus biofilm formation, also if this fraction is lyophilized, that increases its inhibitory properties, highlighting the effect on Pseudomonas aeruginosa. It is possible to incorporate this one to the feed in its lyophilized form without losing its inhibitory properties. In the laboratory, after the administration of the enriched with L. plantarum Ca7 feed to different age snails, the results indicated that this food alters the microbiota, prevents mortality of snails, and improves the microbiological quality of the feed. Based on these results, we can indicate that the administration of the L. plantarum Ca7 strain to snails, and its supernatant for contaminant microorganism control, present in the Heliciculture, would be able to help improve the sanitary livestock through the prevention of diseases of microbial origin, modification of the intestinal microbiota, and ameliorate the microbiological quality of the feed. Which leads to a productive improvement during snail breeding, and delivers added value to the final product, with consequent impact on marketing.
7
Marí, Marí Teresa. "Changes in soil biodiversity and activity along management and climatic gradients". Doctoral thesis, Universitat de Lleida, 2017. http://hdl.handle.net/10803/457976.
Texto completo da fonteResumo:
Els anomenats “rangelands” són àrees sense cultivar, àmpliament pasturades per animals domèstics i salvatges, actualment amenaçats pels canvis climàtic i en l’ús del sòl. Els microorganismes del sòl tenen un paper clau tant en la descomposició com en diversos processos de l’ecosistema, fet pel qual composició i funció de la comunitat microbiana han estat utilitzats durant molt temps com a índexs de fertilitat del sòl.
Els rangelands europeus i africans comparteixen un origen antropogènic comú, però el clima i la gestió del sòl els afecten d’una manera diferent. És per això que aquesta tesi pretén analitzar la comunitat microbiana d’ambdós tipus d’ecosistemes, per tal d’observar els efectes d’algunes de les amenaces comunes des d’una perspectiva més global.
Mentre que la sobrepastura va demostrar tenir l’efecte més perjudicial sobre la funció microbiana en sòls kenyans, es va trobar un efecte més fort del clima sobre els prats europeus. Els fongs i els bacteris van covariar al llarg de gradients altitudinals i climàtics, però la comunitat bacteriana va mostrar una recuperació més ràpida després de les pertorbacions biològiques i físico-químiques del sòl.
Aquest conjunt d’estudis afegeix nous coneixements sobre l’estructura i funció dels rangelands africans i europeus, i convida a explorar noves línies de recerca que incloguin tant bacteris com fongs alhora d’estudiar la comunitat microbiana del sòl.Los llamados "rangelands" son áreas sin cultivar, ampliamente pastoreadas por animales domésticos y salvajes, actualmente amenazados por los cambios climático y de uso del suelo. Los microorganismos del suelo tienen un papel clave tanto en la descomposición como en diversos procesos del ecosistema, por lo que composición y función de la comunidad microbiana han sido utilizados durante mucho tiempo como índices de fertilidad del suelo. Los rangelands europeos y africanos comparten un origen antropogénico común, pero el clima y la gestión del suelo les afectan de una manera diferente. Es por ello que esta tesis pretende analizar la comunidad microbiana de ambos tipos de ecosistemas, a fin de observar los efectos de algunas de las amenazas comunes desde una perspectiva más global. Mientras que el sobrepastoreo demostró tener el efecto más perjudicial sobre la función microbiana en suelos kenianos, se encontró un efecto más fuerte del clima sobre los prados europeos. Los hongos y las bacterias covariaron a lo largo de gradientes altitudinales y climáticos, pero la comunidad bacteriana mostró una recuperación más rápida después de las perturbaciones biológicas y físico-químicas del suelo. Este conjunto de estudios añade nuevos conocimientos sobre la estructura y función de los rangelands africanos y europeos, e invita a explorar nuevas líneas de investigación que incluyan tanto bacterias como hongos en el estudio de la comunidad microbiana del suelo.
Rangelands are uncultivated areas extensively grazed by wild and domestic animals, currently threatened by land use and climatic changes. Soil microorganisms play a key role in decomposition and several ecosystem processes and the composition and function of the microbial community have been long used as indices of soil fertility. African and European rangelands share a common anthropogenic origin, but climate and management affect them in a different way. That is why this thesis aimed to analyze the microbial community of both in order to observe the effects of some common threats from a more global perspective. While overgrazing proved to have the most detrimental effect on the soil microbial function in Kenyan soils, a stronger effect of climate was found to affect European grasslands. Fungi and bacteria co-varied along altitudinal and climatic gradients, but the bacterial community showed a fast recovery after biological and soil physico-chemical disturbances. This group of studies adds new knowledge on the structure and function of the African and European rangelands, and invite to explore new lines of research including both fungal and bacterial consortia when studying the soil microbial community.
8
Huedo, Moreno Pol. "Fatty acid-mediated quorum sensing systems in stenotrophomonas maltophilia". Doctoral thesis, Universitat Autònoma de Barcelona, 2014. http://hdl.handle.net/10803/285570.
Texto completo da fonteResumo:
Els sistemes de comunicació bacteriana -coneguts com quorum sensing (QS)- a través de molècules senyalitzadores del tipus àcid gras han despertat molt d’interès en els darrers anys ja que s’ha vist que molts bacteris patògens els utilitzen per regular funcions relacionades amb la virulència. Es coneix que Stenotrophomonas maltophilia presenta el sistema de QS DSF (Diffusible Signal Factor) el qual és controlat pels gens que conformen el clúster rpf (Regulation of Pathogenecity Factors). No obstant, no està clar els mecanismes pels quals S. maltophilia sintetitza i sensa les molècules senyal així com quines funcions estan regulades per aquest sistema. En aquest treball hem demostrat que existeixen dues poblacions de S. maltophilia les quals es diferencien en base al clúster rpf (rpf-1 o rpf-2) que presenten. Cada variant difereix bàsicament en els gens que codifiquen per la sintasa RpfF i el sensor RpfC. A més, hem observat que existeix una associació entre ambdós components, generant-se la parella RpfF-1/RpfC-1 per les soques rpf-1 i RpfF-2/RpfC-2 per les soques rpf-2. Addicionalment, hem demostrat que només aquelles soques que presenten la variant rpf-1 produeixen nivells detectables de DSF i aquest regula motilitat bacteriana, formació de biofilm i virulència. Per altra banda, les soques de la variant rpf-2 necessiten més còpies de la sintasa RpfF-2 o l’absència del repressor RpfC-2 per produir DSF. En aquest cas, el sistema de QS DSF sembla només regular pocs fenotips relacionats amb virulència en situacions molt específiques. També hem mostrat que existeix un feedback positiu en la síntesi de DSF i que ambdós grups de soques actuen de manera sinèrgica en la producció de DSF i la virulència de tota la població. Addicionalment, hem observat que, mentre la variant RpfC-1 és un sensor promiscu el qual permet l’alliberació de la sintasa RpfF-1 tant punt detecta no només DSF sinó també àcids grassos de cadena mitja, el sensor RpfC-2 és molt més específic, alliberant RpfF-2 només quan detecta DSF.
A més a més, aquí també mostrem com el sistema de QS cis-DA (cis-decenoic) descrit recentment a Pseudomonas aeruginosa és també present a S. maltophilia i regula un alt nombre de factors de virulència. En aquesta línia, hem sigut capaços de caracteritzar preliminarment dos components importants en la biosíntesi de l’àcid gras cis-DA: les enoil coA hidratases (ECH) Smlt0266 i Smlt0267. Hem observat que, mentre la mutació de la hipotètica sintasa Smlt0266 només condueix a l’increment de la formació de biofilm, la mutació en el gen que codifica per la ECH alternativa Smlt0267 implica una reducció dràstica en la formació de biofilm, la motilitat bacteriana, la producció d’exopolisacàrids, la resistència a antibiòtics i la virulència. Resultats similars s’han obtingut per els mutants dels gens ortòlegs a P. aeruginosa, la qual cosa recolza la importància d’aquestes dues ECHs, a més a més del sistema DSF, en la regulació de la virulència i aporta noves dianes interessants pel desenvolupament de teràpies antimicrobianes contra aquest potencial patogen humàFatty-acid mediated Quorum Sensing (QS) systems have aroused considerably interest in the last years since it has been reported that many important bacterial pathogens use these communication systems to regulate virulence-related functions. It is known that Stenotrophomonas maltophilia presents the DSF (Diffusible Signal Factor) QS system, which is controlled by components that are encoded in the rpf cluster (Regulation of Pathogenicity Factors). However, the mechanisms by which S. maltophilia synthesize and sense as well as the biological functions that are under control of DSF-QS remain unclear. Here, we have first demonstrated that two populations of S. maltophilia can be distinguished depending on the rpf cluster (rpf-1 or rpf-2) they harbour. Each variant cluster differs basically in the genes that encode for the synthase RpfF and the sensor RpfC. Moreover, we have observed that there exist a full association between both components, existing the pair RpfF-1/RpfC-1 for the rpf-1 variant and RpfF-2/RpfC-2 for the rpf-2 variant. In addition, we have demonstrated that only strains harbouring the rpf-1 variant produce detectable levels of DSF and it seems to regulate bacterial motility, biofilm development and virulence. On the other hand, strains harbouring the rpf-2 variant need extra copies of rpfF-2 or the absence of rpfC-2 to achieve detectable levels of DSF. In this case, DSF-QS seems to control only some virulence-related phenotypes in very specific environments (e.g., zebrafish infection). We also have shown that DSF is produced in a positive feedback-manner in S. maltophilia, and also, that both rpf-variant groups act synergistically in the DSF production and virulence ability of the whole population. In addition, we have observed that while RpfC-1 is a promiscuous sensor that liberates free active-RpfF-1 -with the subsequent DSF synthesis- upon detection not only DSF, but also saturated medium-length fatty acids, the sensor RpfC-2 only allows activation of RpfF-2 upon detection of DSF-itself, indicating that this sensor component is much more specific. Here, we further report that the cis-DA (cis-decenoic acid) QS system recently described in Pseudomonas aeruginosa is also present in S. maltophilia, and it regulates various virulence factors. In this line, we have preliminary characterized two important components in the biosynthesis of cis-DA, the enoyl-CoA hydratases (ECH) Smlt0266 and Smlt0267. We have observed that while the mutation in the putative synthase smlt0266 lead to alteration basically in biofilm formation, the mutation of the alternative ECH smlt0267 results in a drastic effect in many virulence-related behaviours such as biofilm formation, bacterial motility, exopolysaccharide production, antibiotic resistance and virulence. Similar results have been obtained for the mutants in the orthologous P. aeruginosa genes ∆dspI and ∆dspII. These results further support the significance of these two ECH, in addition to DSF-QS system, in virulence regulation of S. maltophilia and provide new interesting targets for developing new antimicrobial therapies against this potential human pathogen.
9
Aljohny, Bassam Ouda. "Studies on silicon microbiology". Thesis, University of Sheffield, 2011. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.548645.
Texto completo da fonte
10
White, Lorraine. "The microbiology of death". Thesis, University of Sheffield, 2009. http://etheses.whiterose.ac.uk/10361/.
Texto completo da fonteResumo:
The main aim of this research was an attempt to clarify whether the protagonists of bacterial bone destruction were of a bodily origin as opposed to environmental contamination by soil bacteria and furthermore to demonstrate a time frame for such attack. It is hypothesised that bacteria from the gut commensal flora are responsible for micro-focal destruction (MFD) of bone postmortem that leaves distinctive tunnels. Microorganisms live with a person throughout their life and somewhat ironically after death persist to exploit this now nonoperational substrate. They continue to thrive and without a working immune system are capable of crossing mucosal barriers and invading both soft and hard body tissues. Experimental protocol using pigs as human analogues were combined with archaeological sections of both humans and animals. The experimental research was almost absolute in the conclusion that only the fetal material was free of MFD one year post-mortem; these were entirely skeletonised and open to contamination by soil bacteria. All of the other pigs had suffered some form of attack, including those that had not skeletonised and were not therefore subjected to soil bacteria. The archaeological material tended to support the hypothesis that endogenous gut bacteria were the cause of MFD as both fetal material and animal bones were much less likely to be affected. It is suggested that soil bacteria are not normally accountable for MFD although their involvement cannot be ruled out entirely and they may be involved at a later stage. It is therefore likely that endogenous gut bacteria having access to a dead body immediately are most often the cause of MFD and that this occurs well within the early postmortem period. This has negative implications for biomolecular studies and positive implications for in-situ preservation.
11
Kehe, Jared Scott. "Massively parallel combinatorial microbiology". Thesis, Massachusetts Institute of Technology, 2020. https://hdl.handle.net/1721.1/127886.
Texto completo da fonteResumo:
Thesis: Ph. D., Massachusetts Institute of Technology, Department of Biological Engineering, May, 2020Cataloged from PDF version of thesis.
Includes bibliographical references (pages 203-216).
Reductionist biology of the 20th century rooted pure culture methods and antibiotics as pillars of humankind's interaction with microbiology, igniting a revolution in medicine and biotechnology. The revolution was not without cost. By overlooking complex biological interactions, it introduced new problems--from the sharp rise in immune disorders to the antibiotic resistance crisis--that 21st century tools must address. While 'omics methods have fundamentally expanded our understanding of biological complexity, we lack a generalized method for measuring how the parts of a complex system, such as the individual strains of a microbial community, interact with each other. In this thesis, I present kChip, a new platform for constructing massively parallel combinatorial arrays of these parts in order to measure their interactions directly. I describe how kChip has been used to reveal patterns in microbial community assembly, unearth minimal microbial combinations with desirable functions, and screen for compounds that potentiate antibiotic activity. I demonstrate how kChip can advance the development of new technologies like microbial consortia and combinatorial drug therapies.
by Jared Scott Kehe.
Ph. D.
Ph.D. Massachusetts Institute of Technology, Department of Biological Engineering
12
Carrasquilla, Gallego Marc. "El microbioma del agroecosistema y su importancia en la agricultura sostenible". Doctoral thesis, Universitat Autònoma de Barcelona, 2021. http://hdl.handle.net/10803/671606.
Texto completo da fonteResumo:
Les plantes estableixen interaccions amb multitud de microorganismes que influeixen en el seu desenvolupament i supervivència, de manera que aquestes podrien ser considerades com a meta-organismes, la planta depèn de la seva microbiota per obtenir nutrients i com a escut envers malalties, entre altres, i a canvi, la planta li proporciona nutrients en forma d'exsudats que poden representa fins a un 21% del carbó que fixa fotosintèticament. Aquestes interaccions, tant amb la microbiota de les filosfera com la de la rizosfera, són crucials per a la salut de les plantes, la seva adaptació a l'estrès biòtic i abiòtic, així com un element bàsic per aconseguir una agricultura sostenible.
En aquest estudi s'ha caracteritzat la microbiota bacteriana i fúngica associada a la filosfera de dos arbres fruiters, Malus domestica i Pyrus communis, al llarg del seu desenvolupament fenològic, mitjançant tres aproximacions moleculars diferents. Els resultats obtinguts són equivalents per a les tres metodologies pel que fa a la composició taxonòmica de les comunitats microbianes. S'ha definit el core del microbioma per a ambdues espècies vegetals. Dins d'aquest, cal ressaltar la presència de gènere Deinococcus al core del bacterioma, a diferència d'estudis previs i s'ha descrit per primera vegada el core de'l micobioma de la filosfera. S'han establert dos models per explicar la successió microbiana al llarg de tot el cicle vegetatiu de l'arbre, així com biomarcadors representatius per a cada un d'ells.
D'altra banda, s'ha descrit el microbioma de la rizosfera de sòls conductius i supresius per al nematode fitopatógeno Meloidogyne spp., observant marcades diferències entre ells. S'ha caracteritzat el core, destacant la presència de Sporosarcina, Pseudombrophila, Chaetomaiaceae, Cladosporium i Morteriellaceae, com a característics en sòls supresivos. Pel que fa als biomarcadors indicatius de la condició de supressivitat s'han identificat els següents taxons, Acidobacteri, Actinobacteria, Firmicutes, Cladosporium, Pyrenochaeta, Arachniotus, Pseudogymnoascus, Pseudombrophila i Morteriella.
Finalment, es va realitzar uns assajos en test per valorar l'impacte de l'agent de biocontrol contra Meloidogyne incognita, Trichoderma asperellum, sobre la microbiota de la rizosfera de Solanum lycopersicum, on a més es tenien en compte dues variables, la tipologia de terra supressiu i la varietat vegetal (resistent o sensible a el patogen). Els resultats obtinguts han posat de manifest que els factors determinants en la composició taxonòmica de la microbiota de terra rizosfèric són en ordre decreixent d'importància, la tipologia de terra i la varietat vegetal. No s'ha pogut valorar l'efecte de Trichoderma asperellum donada la manca de prevalença d'aquest agent de biocontrol a terra.Las plantas establecen interacciones con multitud de microorganismos que influyen en su desarrollo y supervivencia, de manera que estas podrían ser consideradas como metaorganismos, la planta depende de su microbiota para obtener nutrientes y como escudo contra enfermedades, entre otros, y a cambio, la planta le proporciona nutrientes en forma de exudados que pueden representar hasta un 21% del carbono que fija fotosintéticamente. Dichas interacciones, tanto con la microbiota de las filosfera como la de la rizosfera, son cruciales para la salud de las plantas, su adaptación al estrés biótico y abiótico, así como un elemento básico para conseguir una agricultura sostenible. En este estudio se ha caracterizado la microbiota bacteriana y fúngica asociada a la filosfera de dos árboles frutales, Malus domestica y Pyrus communis, a lo largo de su desarrollo fenológico, mediante tres aproximaciones moleculares diferentes. Los resultados obtenidos son equivalentes para las tres metodologías en cuanto a la composición taxonómica de las comunidades microbianas. Se ha definido el core del microbioma para ambas especies vegetales. Dentro de este, cabe resaltar la presencia de género Deinococcus en el core del bacterioma, a diferencia de estudios previos y se ha descrito por primera vez el core del micobioma de la filosfera. Se han establecido dos modelos para explicar la sucesión microbiana a lo largo del ciclo vegetativo del árbol, así como biomarcadores representativos para cada uno de ellos. Por otro lado, se ha descrito el microbioma de la rizosfera de suelos conductivos y supresivos para el nematodo fitopatógeno Meloidogyne spp., observándose marcadas diferencias entre ellos. Se ha caracterizado el core, destacando la presencia de Sporosarcina, Pseudombrophila, Chaetomaiaceae, Cladosporium y Morteriellaceae, como característicos en suelos supresivos. Respecto a los biomarcadores indicativos de la condición de supresividad se han identificado los siguientes taxones, Acidobacteria, Actinobacteria, Firmicutes, Cladosporium, Pyrenochaeta, Arachniotus, Pseudogymnoascus, Pseudombrophila y Morteriella. Finalmente, se realizó unos ensayos en maceta para valorar el impacto del agente de biocontrol contra Meloidogyne incognita, Trichoderma asperellum, sobre la microbiota de la rizosfera de Solanum lycopersicum, donde además se tenían en cuenta dos variables, la tipología del suelo supresivo y la variedad vegetal (resistente o sensible al patógeno). Los resultados obtenidos han puesto de manifiesto que los factores determinantes en la composición taxonómica de la microbiota del suelo rizosferico son en orden decreciente de importancia, la tipología del suelo y la variedad vegetal. No se ha podido valorar el efecto de Trichoderma asperellum dada la falta de prevalencia de este agente de biocontrol en el suelo.
Plants establish interactions with a multitude of microorganisms that influence their development and survival, so that these could be considered as meta-organisms, the plant depends on its microbiota to obtain nutrients and as a shield against diseases, among others, and in return, the plant provides it with nutrients as exudates, that can represent up to 21% of the carbon it fixes photosynthetically. Such interactions, both with the phyllosphere and rhizosphere microbiota, are crucial for the health of plants, their adaptation to biotic and abiotic stresses, as well as a basic element for achieving sustainable agriculture. In this study, the bacterial and fungal microbiota associated with the phyllosphere of two fruit trees, Malus domestica and Pyrus communis, have been characterized throughout their phenological development, using three different molecular approaches. The results obtained are equivalent for the three methodologies regarding the taxonomic composition of the microbial communities. The core of the microbiome has been defined for both plant species. Within this, it is worth to highlight the presence of the genus Deinococcus in the core of the bacteriome, unlike previous studies and the core of the mycobiome of the phyllosphere has been described for the first time. Two models have been established to explain the microbial succession along the vegetative cycle of the tree, as well as representative biomarkers for each of them. On the other hand, the rhizosphere microbiome of conductive and suppressive soils has been described for the phytopathogenic nematode Meloidogyne spp., obbserving marked differences between them. The core has been characterized, highlighting the presence of Sporosarcina, Pseudombrophila, Chaetomaiaceae, Cladosporium and Morteriellaceae, as characteristic in suppressive soils. Regarding the biomarkers indicative of the suppressive condition, the following taxa have been identified: Acidobacteria, Actinobacteria, Firmicutes, Cladosporium, Pyrenochaeta, Arachniotus, Pseudogymnoascus, Pseudombrophila and Morteriella. Finally, a pot assay was carried out to assess the impact of the biocontrol agent against Meloidogyne incognita, Trichoderma asperellum, on the microbiota of the rhizosphere of Solanum lycopersicum, where two variables were also considered, the type of suppressive soil and the variety plant (resistant or sensitive to the pathogen). The results obtained have shown that the determining factors in the taxonomic composition of the rhizospheric soil microbiota are, in decreasing order of importance, the typology of the soil and the vegetable variety. The effect of Trichoderma asperellum could not be evaluated given the lack of prevalence of this biocontrol agent in the soil.
Universitat Autònoma de Barcelona. Programa de Doctorat en Microbiologia
13
Lima, Raquel Maria Torres. "Relevance of Latent EBV infection in drug response of burkitt lymphoma cells". Doctoral thesis, Faculdade de Farmácia da Universidade do Porto, 2009. http://hdl.handle.net/10216/53912.
Texto completo da fonte
14
Freitas, Ana Raquel Pinho. "Ecology and evolution of antimicrobial resistance in Enterococcus: a multilayered molecular approach with emphasys in the plasmid diversity". Doctoral thesis, Faculdade de Farmácia da Universidade do Porto, 2010. http://hdl.handle.net/10216/63801.
Texto completo da fonte
15
Lima, Raquel Maria Torres. "Relevance of Latent EBV infection in drug response of burkitt lymphoma cells". Tese, Faculdade de Farmácia da Universidade do Porto, 2009. http://hdl.handle.net/10216/53912.
Texto completo da fonte
16
Freitas, Ana Raquel Pinho. "Ecology and evolution of antimicrobial resistance in Enterococcus: a multilayered molecular approach with emphasys in the plasmid diversity". Tese, Faculdade de Farmácia da Universidade do Porto, 2010. http://hdl.handle.net/10216/63801.
Texto completo da fonte
17
Grant, Irene Ruth. "The microbiology of irradiated pork". Thesis, Queen's University Belfast, 1990. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.335332.
Texto completo da fonte
18
Robinson, Tobin. "The microbiology of food microenvironments". Thesis, Cardiff University, 1992. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.387586.
Texto completo da fonte
19
Athukorala, Arachchi Seneviratne Chaminda Jayampath. "Molecular microbiology of candida biofilms". Thesis, Click to view the E-thesis via HKUTO, 2008. http://sunzi.lib.hku.hk/hkuto/record/B4068751X.
Texto completo da fonte
20
Zúñiga, Olate Roberto Aquiles. "Estudios funcionales y estructurales de la triptofanil tRNA sintetasa de Acidithiobacillus ferrooxidans". Tesis, Universidad de Chile, 2002. http://www.repositorio.uchile.cl/handle/2250/106690.
Texto completo da fonte
21
Shinya, Thaís Yumi [UNESP]. "Produção, purificação e ação antimicrobiana do extrato fúngico do Trichosporon asahii". Universidade Estadual Paulista (UNESP), 2012. http://hdl.handle.net/11449/94853.
Texto completo da fonteResumo:
Made available in DSpace on 2014-06-11T19:27:21Z (GMT). No. of bitstreams: 0
Previous issue date: 2012-11-05Bitstream added on 2014-06-13T19:14:42Z : No. of bitstreams: 1
shinya_ty_me_sjrp.pdf: 938343 bytes, checksum: c5a013f3a467162e18061087abbec274 (MD5)Devido à necessidade de obtenção de novas moléculas com ação antimicrobiana, o presente trabalho visou investigar a capacidade antagônica do extrato produzido pelo fungo Trichosporon asahii. O extrato foi obtido pela fermentação do fungo em fermentador de bancada 7L, a 28°C por 72 horas. O caldo fermentado foi centrifugado a 2500 rpm por 20 minutos, sendo o sobrenadante a fração denominada extrato bruto, que foi seco em estufa (37°C) e ressuspendido em água destilada, para testes de ação antimicrobiana contra os micro-organismos Candida albicans, Malassezia pachydermatis, Trichophyton mentagrophytes, Pseudomonas aeruginosa ATCC 9027 e ATCC 27853, Xanthomonas campestris pv campestris. O teste de sensibilidade foi o de Concentração Bactericida e Fungicida Mínima (CBM e CFM), através da macrodiluição em tubos e plaqueamento. Numa segunda etapa, o extrato bruto foi submetido a uma separação líquido-líquido utilizando os solventes hexano e diclorometano, obtendo-se frações aquosa e orgânica. Numa última etapa de purificação, o extrato diclorometânico passou por uma cromatografia de troca-iônica, cromatografia em sílica gel e precipitação com sulfato de amônio. Foram calculados alguns parâmetros de fermentação do T. asahii, através dos métodos de quantificação de açúcares redutores, pH, viabilidade e brotamento das leveduras e quantidade total de células. O teste de sensibilidade do extrato bruto demonstrou apenas atividade antibacteriana (30000 µg/mL sobre P. aeruginosa ATCC 9027, 33000 µg/mL sobre P. aeruginosa ATCC 27853 e 75000 µg/mL sobre X. campestris). Observou-se uma diminuição da CBM para a fração diclorometânica (17500 µg/mL sobre P. aeruginosa ATCC 9027, 20000 µg/mL sobre P. aeruginosa ATCC 27853 e 60000 µg/mL sobre X. campestris). Na pré-purificação, o método que demonstrou maior eficácia para o propósito...
Nowadays there is a demand for new natural molecules that may contribute to the control of pathogenic microorganisms. In this study it was aimed to investigate the antimicrobial ability of the broth produced by the culture of the fungus Trichosporon asahii. The extract was obtained by fermentation of T. asahii bench 7 L fermenter at 28° C for 72 hours. The fermented broth was centrifuged at 2500 rpm for 20 minutes, and the supernatant fraction termed crude extract, which was dried in oven (37° C) and resuspended in distilled water for testing antimicrobial activity against the microorganisms Candida albicans, Malassezia pachydermatis, Trichophyton mentagrophytes, Pseudomonas aeruginosa ATCC 9027 and ATCC 27853 and Xanthomonas campestris pv campestris. The method used for quantification of antibiotic was the Minimum Bactericidal and Fungicidal Concentration (MBC and MFC) by macrodilution tubes and plating. In a second stage, the crude extract was subjected to liquid-liquid separation using dichloromethane and hexane solvents to yield aqueous and organic fractions. A new purification step from the dichloromethanic fraction passed through an ion exchange chromatography, silica gel chromatography and by precipitation with ammonium sulfate. It was also calculated some fermentation parameters of T. asahii by analytical methods for quantifying reducing sugars, pH, cell viability, budding yeasts and total cells. The MBC test showed only antibacterial activity (33,000 µg/mL for P. aeruginosa ATCC 27853, 30,000 µg/mL for P. aeruginosa ATCC 9027 and 75,000 µg/mL for X. campestris). There was a decrease in the MBC for the dichloromethanic fraction (20,000 µg/mL for P. aeruginosa ATCC 27853, 17,500 µg/mL for P. aeruginosa ATCC 9027 and 60,000 µg/mL for X. campestris). In the pre-purification step, the ion exchange chromatography was the more effective method... (Complete abstract click electronic access below)
22
Shinya, Thaís Yumi. "Produção, purificação e ação antimicrobiana do extrato fúngico do Trichosporon asahii /". São José do Rio Preto : [s.n.], 2012. http://hdl.handle.net/11449/94853.
Texto completo da fonteResumo:
Orientador: Pedro de Oliva NetoBanca: Ary Fernandes Júnior
Banca: Valéria Marta Gomes Lima
Resumo: Devido à necessidade de obtenção de novas moléculas com ação antimicrobiana, o presente trabalho visou investigar a capacidade antagônica do extrato produzido pelo fungo Trichosporon asahii. O extrato foi obtido pela fermentação do fungo em fermentador de bancada 7L, a 28°C por 72 horas. O caldo fermentado foi centrifugado a 2500 rpm por 20 minutos, sendo o sobrenadante a fração denominada extrato bruto, que foi seco em estufa (37°C) e ressuspendido em água destilada, para testes de ação antimicrobiana contra os micro-organismos Candida albicans, Malassezia pachydermatis, Trichophyton mentagrophytes, Pseudomonas aeruginosa ATCC 9027 e ATCC 27853, Xanthomonas campestris pv campestris. O teste de sensibilidade foi o de Concentração Bactericida e Fungicida Mínima (CBM e CFM), através da macrodiluição em tubos e plaqueamento. Numa segunda etapa, o extrato bruto foi submetido a uma separação líquido-líquido utilizando os solventes hexano e diclorometano, obtendo-se frações aquosa e orgânica. Numa última etapa de purificação, o extrato diclorometânico passou por uma cromatografia de troca-iônica, cromatografia em sílica gel e precipitação com sulfato de amônio. Foram calculados alguns parâmetros de fermentação do T. asahii, através dos métodos de quantificação de açúcares redutores, pH, viabilidade e brotamento das leveduras e quantidade total de células. O teste de sensibilidade do extrato bruto demonstrou apenas atividade antibacteriana (30000 µg/mL sobre P. aeruginosa ATCC 9027, 33000 µg/mL sobre P. aeruginosa ATCC 27853 e 75000 µg/mL sobre X. campestris). Observou-se uma diminuição da CBM para a fração diclorometânica (17500 µg/mL sobre P. aeruginosa ATCC 9027, 20000 µg/mL sobre P. aeruginosa ATCC 27853 e 60000 µg/mL sobre X. campestris). Na pré-purificação, o método que demonstrou maior eficácia para o propósito... (Resumo completo, clicar acesso eletrônico abaixo)
Abstract: Nowadays there is a demand for new natural molecules that may contribute to the control of pathogenic microorganisms. In this study it was aimed to investigate the antimicrobial ability of the broth produced by the culture of the fungus Trichosporon asahii. The extract was obtained by fermentation of T. asahii bench 7 L fermenter at 28° C for 72 hours. The fermented broth was centrifuged at 2500 rpm for 20 minutes, and the supernatant fraction termed crude extract, which was dried in oven (37° C) and resuspended in distilled water for testing antimicrobial activity against the microorganisms Candida albicans, Malassezia pachydermatis, Trichophyton mentagrophytes, Pseudomonas aeruginosa ATCC 9027 and ATCC 27853 and Xanthomonas campestris pv campestris. The method used for quantification of antibiotic was the Minimum Bactericidal and Fungicidal Concentration (MBC and MFC) by macrodilution tubes and plating. In a second stage, the crude extract was subjected to liquid-liquid separation using dichloromethane and hexane solvents to yield aqueous and organic fractions. A new purification step from the dichloromethanic fraction passed through an ion exchange chromatography, silica gel chromatography and by precipitation with ammonium sulfate. It was also calculated some fermentation parameters of T. asahii by analytical methods for quantifying reducing sugars, pH, cell viability, budding yeasts and total cells. The MBC test showed only antibacterial activity (33,000 µg/mL for P. aeruginosa ATCC 27853, 30,000 µg/mL for P. aeruginosa ATCC 9027 and 75,000 µg/mL for X. campestris). There was a decrease in the MBC for the dichloromethanic fraction (20,000 µg/mL for P. aeruginosa ATCC 27853, 17,500 µg/mL for P. aeruginosa ATCC 9027 and 60,000 µg/mL for X. campestris). In the pre-purification step, the ion exchange chromatography was the more effective method... (Complete abstract click electronic access below)
Mestre
23
Jeffery, Simon. "The microbiology of arable soil surfaces". Thesis, Cranfield University, 2007. http://dspace.lib.cranfield.ac.uk/handle/1826/2245.
Texto completo da fonteResumo:
Whilst much is known about the physics and erosion of soil surfaces on a millimetre scale, little is known about the associated microbiology, particularly in temperate arable systems. The vast majority of research regarding microbial interactions at soil surfaces has concerned microbiotic crusts. However, such surface crusts take many years to form and then only in relatively undisturbed soil systems. Arable soil surfaces are subject to relatively extreme environmental conditions, potentially undergoing rapid changes in relation to temperature, water status and solar radiation compared to deeper soil zones. These extreme environmental parameters are likely to have a large impact on the biota found at the arable soil surface when compared to that which occurs in deeper soil zones. Phenotypic profiling using phospholipid fatty acid (PLFA) analysis, microbial biomass, and chlorophyll concentration were used to characterise soil microbial communities with the aim of quantifying differences within the surface layers of arable systems on a millimetre scale. This field work was supported with a series of microcosm-scale studies in which parameters such as length of time between disturbance events and the quality of light reaching the soil surface were controlled. Using microcosms subjected to simulated rainfall and imaged using X-ray computed tomography scanning, the effects of the soil surface microbiota on associated physical properties including structural integrity, porosity, erodibility and hydrological properties were investigated. This research showed that given sufficient time between disturbance events, environmental parameters such as temperature and wet:dry cycling were sufficient to drive the formation of a distinct soil surface phenotype, which appeared to be consistently confined to an order of depth of circa 1 mm. It was notable that the PLFA 16:0 was consistently associated with discrimination between phenotypes between soil surface layers. Calculation of the ratio of fungal to bacterial PLFA biomarkers showed a consistently higher ratio of fungi to bacteria present in the soil surface layer to a depth of circa 1 mm, providing evidence that fungi grow preferentially over the soil surface compared to through the soil matrix. Further investigation demonstrated that light, particularly at photosynthetically active wavelengths, was the main driving factor in the establishment of the distinct soil surface phenotypes. The inocula which drove the formation of such soil-surface community phenotypes, especially the photoautotrophic components, was demonstrated to derive predominantly from aerial sources. Functionally the nature of the soil surface community was found to affect run-off generation and shear strength at the surface. There was no significant impact of the soil surface microbiota on erodibility or water infiltration rates, although whilst distinct surface phenotypes had developed in this experimental circumstance, these were relatively deficient in photoautotrophs compared to other microcosm experiments and field circumstances, and hence extrapolation of this conclusion is not sound. This project has demonstrated that a soil surface ecological niche may exist in other unexplored soil surfaces and highlights the needs to explore this possibility and to examine any associated functional consequence should such niches be found to exist.
24
Al-Wajeeh, Khaled Mohsen. "Studies on the microbiology of silicon". Thesis, University of Sheffield, 1999. http://etheses.whiterose.ac.uk/10225/.
Texto completo da fonteResumo:
A study was made of the interactions between the element silicon, mainly as silicic acid, and various microbial processes. The effect of silicon compounds on fungal growth was determined under both oligotrophic and nutrient-rich (copiotrophic) conditions. Mycelium of Aspergillus oryzae was grown from a spore inoculum added to ultra-pure water (upw) containing silicon compounds, but not in upw alone. Growth of other fungi also only occurred in upw when silicon compounds were added. Increased growth of fungi also followed the addition of silicon compounds to Czapek Dox medium. Silicic acid also increased the protein content of fungi grown under such nutrient-rich conditions. The fungi solubilised the insoluble silicon compounds under both oligotrophic and copiotrophic conditions. Silicon was not however, accumulated by fungi as electron-dense hyphal bodies. Addition of silicic acid to nutrient rich media also increased the growth of species of Streptomyces but decreased the chlorophyll content of the alga, Dunaliella parva; the growth of two yeasts and the bacteria, E. colt and S. aureus also was not affected by silicon addition; the observed stimulatory effect therefore appears to be restricted to filamentous microorganisms. The effect of silicon compounds on various microbial processes was also investigated. Silicic acid stimulated the production of citric acid by Aspergillus niger, but decreased nitrification and sulphur oxidation in this fungus. Silicic acid addition also led to a reduction in antibiotic production by species of Streptomyces. Studies were initiated to study the possibility that fungi and bacteria can erode the surface of both bulk and porous silicon wafers. While no such surface erosion was evident, we observed that E. coif underwent extensive extreme pleomorphism when growing under starvation conditions for up to 14 days. Such pleomorphism consisted of the formation of bulbous protrusions from the normal rod, dumbbell-shaped cells and long filaments, these were up to 50g in length (compared to the normal 1-3μ, rods). Such filamentation was clearly caused by the inability of the bacterial cells (rods) to separate on division. The observed bacterial pleomorphism was not however, silicon-specific, as it was also found to occur on titanium and glass surfaces. Such extreme pleomorphism may have important implications in relation to the growth of E. coli in low nutrient environments and may influence the bacterium's ability to affect pathogenesis. While the microbiology of silicon has largely been neglected the results of this thesis show that there is considerable interaction between this element and microbial growth. Future studies should in particular be directed towards determining if silicon can be used as an energy source by microorganisms. Additionally, the observed phenomenon of extreme pleomorphism in E. coil is clearly worthy of further study.
25
Frau, Alessandra. "Molecular microbiology of hydrocarbon polluted groundwater". Thesis, Queen's University Belfast, 2014. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.676470.
Texto completo da fonteResumo:
The thesis is focused on the study of the microbiology of groundwater contaminated by diesel with three main goals. Firstly, to characterize the natural attenuation process, secondly, to increase knowledge of the role of microorganisms in the remediation of polluted environments and thirdly, to evaluate the efficacy of molecular biology methods to assess the in situ biodegradation potential of the microorganisms in such contaminated areas. This study includes the metagenomic characterization of the microbial community through the exploitation of next-generation sequencing techniques and the quantification of key biodegrative genes as biomarkers. Moreover, several strategies were put in place to understand the role of an uncultivated bacterial phylum (the OD1 candidate division) in the biodegradation of organic pollutants. These included the design of primer sets for the amplification of a functional gene specific for OD1 and the phylogenetic analysis of 16S rRNA sequences assigned to OD1 from several studies and a public database. A main outcome has been the characterization of the natural attenuation process in the site. A network of fermentative syntrophic bacteria and methanogenic archaea are the likely the protagonists of this process. The role of OD1 in the fermentation process was proposed. A thorough analysis of OD1 distribution has been carried out and phylogenetic cluster of ODl clades involved in this complex trophic network of fermentative bacteria and methanogens was identified.
26
Ngo, Chinh Chung. "Microbiology and Immunology of Otitis Media". Thesis, Griffith University, 2016. http://hdl.handle.net/10072/365263.
Texto completo da fonteResumo:
Background
Over 80% of children experience acute otitis media (AOM) at least once during childhood, with 10-30% of children experiencing recurrent episodes of AOM (RAOM) or persistence of fluid in the middle ear (ME) lasting greater than 3 months which is defined as chronic otitis media with effusion (COME). Microbial infection remains the main cause of AOM, however the causes of RAOM and COME are not fully understood. Heavy loads of microbial colonisation and bacterial/viral interaction in the upper respiratory tract (URT) contribute to OM pathogenesis. It is currently unclear whether compromised host immune system responses have a significant role in RAOM/COME. Bacterial biofilms within the ME may contribute to otopathogen persistence and recurrent infection and/or inflammation in these children.
Aims
This study identified the predominant bacterial and viral otopathogens within the URT and ME, of children undergoing ventilation tube insertion (VTI) for RAOM/COME. Bacterial persistence within the ME, in the form of biofilms was also examined. Bacteria and viruses which were identified within the URT of children with RAOM/COME were compared to a control group of children who were undergoing adenoidectomy for treatment of adenoidal hypertrophy (AH) and/or obstructive sleep apnoea (OSA).
Local (saliva, middle ear effusion (MEE)) and systemic (serum) innate and adaptive immune responses were examined in children with and without RAOM/COME. Specific antibody levels to bacterial proteins as well as cytokine levels were determined. Systemic immuno-gene expression was compared between children with RAOM/COME and AH/OSA.Thesis (PhD Doctorate)
Doctor of Philosophy (PhD)
School of Medical Science
Griffith Health
Full Text
27
TRINCHERA, MARIACRISTINA. "INNOVATION OF DIAGNOSTIC SYSTEM IN MICROBIOLOGY". Doctoral thesis, Università di Siena, 2016. http://hdl.handle.net/11365/1010583.
Texto completo da fonteResumo:
The objective of this project is to create a highly automated system for screening urinary tract infections. Urinary infections are the major cause of diagnostic intervention (in and outpatient). The urino culture is the most required examination in the field of microbiology. The intention is to perform a series of analyses on a urine sample in order to highlight early pathological situations in other body districts.
There is urgency in the field of microbiology to become equipped with instruments that can act in automation at the call of diagnostic demand. There is also a request that the innovation have characteristics of sustainability according to the quality regulations dictated by the ISO 9000 quality management system. Furthermore, there is a need for the standardization of data. Currently, the medical microbiology field is not aligned with the rest of the world of analysis laboratories. Nowadays, in the normal laboratory, high automation diagnostic technology is present, particularly in the area of clinical chemistry. Microbiology is delayed for two main reasons: 1) elaborate analysis methods; 2) semi-quantitative interpretation of the results.
The DIESSE Diagnostica Senese spa, understanding the necessity, has built an analysis system specifically for the screening of urinary infections. In this work, we present the experimentation process PLUS FINDER++, the results from which offer decisive improvement in response quality, and timing. It is capable of influencing the diagnostic process positively because the PLUS FINDER++ reports the results of the sample analysis in 2 hours and 46 minutes, compared to the standard 48 to 72 hours. It must also not be underestimated that, thanks to these qualities, healthcare costs undergo a substantial reduction.
The experimentation was carried out in a number of healthcare structures, through a constant connection, in the analysis of the level of criticality, between the DIESSE operators present in the external structure alongside the in-house healthcare workers, in continual discussion with the professional operators of the primary company with its headquarters in Siena. It was this continuity and the analysis of the level of criticality in software defects, homepage graphics of the instrument or mechanical problems that have made an essential contribution to optimising the success of the PLUS FINDER++ System.
28
Reffatti, Leonardo. "Diferenciação da origem geográfica de vinhos elaborados com uvas de três regiões vitícolas de Santa Catarina através de análises isotópicas e elementos minerais". reponame:Repositório Institucional da UCS, 2016. https://repositorio.ucs.br/handle/11338/2443.
Texto completo da fonteResumo:
A origem e a tipicidade dos vinhos são temas importantes e de grande interesse para produtores, consumidores e comerciantes. Ambos estão ligados à obtenção de um reconhecimento deste produto perante o mercado consumidor. O Brasil apresenta dimensões continentais e uma ampla diversidade de regiões produtoras de uvas e vinhos, em cada uma encontra-se características peculiares. Santa Catarina é o quarto estado brasileiro em área plantada com videiras no Brasil, apesar disso, é o segundo maior estado produtor de vinhos, apresentando grande potencial para vitivinicultura. Neste estudo coletou-se amostras de uvas de três regiões produtoras de vinhos objetivando diferenciá-las através da utilização de análises da razão isotópica de Oxigênio (18O) da água e do Carbono (13C) do etanol, bem como do conteúdo minerais dos vinhos. Foram estudados vinhos varietais, elaborados através de microvinificações, das variedades de uva Cabernet Sauvignon e Merlot, safra 2013, provenientes das regiões de Santa Catarina: Carbonífera, Vale do Rio do Peixe e Planalto Serrano de São Joaquim. As análises isotópicas foram realizadas por espectrometria de massa da razão isotópica (IRMS) e a determinação dos elementos minerais por espectrometria de massa com plasma indutivamente acoplado (ICP-MS). Os valores da razão isotópica do oxigênio (18O) da água do vinho Cabernet Sauvignon foram eficientes para diferenciar os vinhos das três regiões, apresentando maiores valores médios para a região Vale do Rio do Peixe 3,31‰, seguidos por valores da região Carbonífera 1,48‰ e valores mais negativos -2,70‰ para a região Planalto Serrano de São Joaquim. O 18O em vinhos Merlot também diferenciou as duas regiões estudadas, de maneira similar aos resultados da variedade Cabernet Sauvignon, onde os valores maiores ocorreram na região Vale do Rio do Peixe 3,72‰ e o mais negativo na região Planalto Serrano de São Joaquim -2,76‰. Os resultados de 18O dependem principalmente de condições climáticas no período pré-colheita das uvas. Os resultados obtidos do 13C do etanol dos vinhos Cabernet Sauvignon não diferenciaram as três regiões de Santa Catarina, porém os valores encontrados do 13C do etanol dos vinhos Merlot foram mais negativos na região Planalto Serrano de São Joaquim -29,55‰ e menos negativos na região Vale do Rio do Peixe -28,67‰, sendo possível diferenciar estas duas regiões. Na região Vale do Rio do Peixe foi possível diferenciar vinhos Cabernet Sauvignon -29,80‰ de vinhos Merlot -28,67‰, esta mesma diferenciação ocorreu para a região Planalto Serrano de São Joaquim, onde vinhos Cabernet Sauvignon apresentaram valores de -30,47‰ e vinhos Merlot -29,55‰. Um amplo conjunto de elementos minerais como B, Na, Mg, Al, K, Ca, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, As, Se, Rb, Sr, Zr, Nb, Cd, Sb, Cs, Ba e Pb foram quantificados para diferenciação geográfica das regiões estudadas. Nenhum dos elementos minerais estudados individualmente neste trabalho possibilitou a diferenciação das três regiões estudadas para vinhos Cabernet Sauvignon. Contudo, analisando os resultados obtidos para Mg, Al, Ca, Mn, Se, Rb, Sr, Zr, Nb, Cs e Ba, em conjunto, diferenciaram pelos menos uma das regiões estudadas para vinhos varietais de Cabernet Sauvignon, do mesmo modo para vinhos Merlot. A partir dos resultados do 18O, B, Mg, Al, V, Mn, Co, Cu, Se, Rb, Sr, Cd e Sb, obteve-se equações com classificação de 100% para as três regiões estudadas.Submitted by Ana Guimarães Pereira (agpereir@ucs.br) on 2017-04-26T14:04:26Z No. of bitstreams: 1 Dissertacao Leonardo Reffatti.pdf: 1201198 bytes, checksum: 541b71591becc056b52f84e624af9bf8 (MD5)
Made available in DSpace on 2017-04-26T14:04:26Z (GMT). No. of bitstreams: 1 Dissertacao Leonardo Reffatti.pdf: 1201198 bytes, checksum: 541b71591becc056b52f84e624af9bf8 (MD5) Previous issue date: 2017-04-26
Wine origin and typicity are important issues and big interest for producers, consumers and traders. Both are linked to the achievement of wine recognition by the consumer market. Brazil has continental dimensions and a wide winegrowing diversity regions, each one with unique characteristics. Santa Catarina occupies the fourth state place in Brazilian surface area with vineyards, on the other hand, it´s the second in wine production, showing a potential for this activity. In this study, samples of three regions in Santa Catarina were collected aiming differ them by geographic localization, using oxygen isotopic ratio analysis (18O) of water, carbon isotopic ratio (13C) of ethanol, and mineral 85Rb and 88Sr wine content. Varietal Carbernet Sauvignon and Merlot wines were elaborated by microvinifications, vintage 2013, from the regions: Carbonífera, Vale do Rio do Peixe and Planalto Serrano de São Joaquim. Isotopic analysis of oxygen and carbon were performed by mass spectrometry isotope ratio (IRMS), and mineral elements by inductively coupled plasma-mass spectrometry (ICPMS). Wine water average values of 18O in Cabernet Sauvignon wines were efficient to differ wines from the three regions, demonstrating higher average values for Vale do Rio do Peixe region (3,31‰), followed by Carbonífera region (1,48‰), and Planalto Serrano de São Joaquim region showed negative values (-2,70‰). Similarly to Cabernet Sauvignon, wine water average values of 18O in Merlot wines were effective in differentiating just two regions, the higher values were exhibited for Vale do Rio do Peixe (3,72‰), and lower values for Planalto Serrano de São Joaquim (-2,76‰). Oxygen isotopic ratio depends mainly of whether conditions during grape maturation and harvest. Wine ethanol average values for 13C in Cabernet Sauvignon wines were not able to differ the three regions of Santa Catarina, however average values found to Merlot wines were able, evincing more negative values in Planalto Serrano de São Joaquim (-29,55‰), and less negative to Vale do Rio do Peixe (-28,67‰). Further on the geographic differentiation, the 13C showed potential to differentiate varieties inside a region. In Vale do Rio do peixe region, wine ethanol average 13C for Cabernet Sauvignon wines (-29,80‰) showed difference to Merlot wines (-28,57‰), the same differentiation occurred to Planalto Serrano de São Joaquim region, where Cabernet Sauvignon wines demonstrated values of (-30,47‰) and Merlot wines (-29,55‰). A wide range of mineral elements such as B, Na, Mg, Al, K, Ca, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, As, Se, Rb, Sr, Zr, Nb, Cd, Sb, Cs, Ba and Pb were quantified to geographic differentiation between the studied regions. None of the mineral elements individually studied in this work allowed the differentiation of the three regions studied for Cabernet Sauvignon wines. However, the results for Mg, Al, Ca, Mn, Se, Rb, Sr, Zr, Nb, Cs and Ba differentiated at least one of the studied regions in Cabernet Sauvignon wines, it was also possible to differentiate the two regions studied in Merlot wines. A group of 18O, B, Mg, Al, V, Mn, Co, Cu, Se, Rb, Sr, Cd e Sb results classified the three regions by 100%.
29
Oliveira, Daniel Paulo de. "Produção de amilase por Bacillus licheniformis utilizando meios de baixo custo". Universidade Católica de Pernambuco, 2007. http://www.unicap.br/tede//tde_busca/arquivo.php?codArquivo=186.
Texto completo da fonteResumo:
A indústria biotecnológica enzimática vem aumentando progressivamente nas últimas décadas com a utilização e produção de diversas enzimas microbianas. As amilases são enzimas que hidrolisam moléculas de amido liberando diversos produtos secundários, incluindo as dextrinas e progressivamente por unidades de glicose. Apresentam um amplo campo de aplicações na indústria de alimentos, em cervejarias e bebidas fermentadas, em cereais para alimentação infantil e ração animal, indústrias de papel e celulose, têxtil, de detergentes, química, farmacêutica e produtos de limpeza. Foram realizados ensaios de seleção em meio sólido para produção de amilase por 05 isolados de ambientes contaminados por petróleo em diferentes temperaturas (28 e 37 C), respectivamente. Os resultados obtidos evidenciaram que o isolado Bacillus licheniformis UCP 1009 apresentou a formação de halo característico de 55 mm para amilase, após 72 horas de incubação. Após a seleção do microrganismo, foram realizados fermentações para produção de amilase, substituindo o amido solúvel, pelo amido de milho e de batata, através de um planejamento fatorial 23 com quatro pontos centrais, tendo a variável de resposta a produção de amilase, durante 96 horas. Foram estabelecidos o perfil de crescimento microbiano, o pH, o consumo de glicose pelo método do DNS e a determinação da atividade específica da enzima. Os resultados obtidos evidenciaram que o amido de milho apresentou uma atividade específica de 0,756 U/mg, a um pH de 8,82 e uma atividade enzimática da amilase de 0,99 U/dL, demonstrando um potencial industrialThe enzymatic biotechnology industry is growing up progressively in the last decades with the utilization e production of diverse microbial enzymes. Amylases are enzymes which hydrolyze starch molecules to give diverse products including dextrin's and progressively glucose units. They play a wide field of applications. In food industries, in beer industry and others fermented drinks, in cereal for baby's food and animal feed, in paper and cellulose industry, textile industry, in detergent and cleaning products industry, in chemical and pharmaceutical industry. Screening was carrying out in solid media to amylase production in 5 strains isolated from contaminated ambient by petroleum in different temperatures (28 C and 37 C), respectively. The results obtained evidenced that the isolated Bacillus licheniformis UCP 1009 showed the halo formation characteristically of the 55 mm to amylase, after 72 hours of incubation. After the selection of the microorganism, fermentations was carrying out to amylase production, replacing the soluble starch, by corn starch and potato starch, trough of factorial planning 23 with 4 central's points, having a amylase's production as a answering variable, during 96 hours. The microbial growth profile was established, the pH, the glucose consumption by the DNS and determination of specific enzyme activity. The results obtained evidenced that the corn starch shown an specific activity of 0.756 U/mg, at a pH of 8.82 and a enzymatic activity of amylase 0.99 U/dL, showing a industrial potential
30
Pereira, Rodrigo de Paula [UNESP]. "A atividade antimicrobiana de agentes desinfetantes incorporados ao gesso tipo IV". Universidade Estadual Paulista (UNESP), 2009. http://hdl.handle.net/11449/98032.
Texto completo da fonteResumo:
Made available in DSpace on 2014-06-11T19:29:12Z (GMT). No. of bitstreams: 0
Previous issue date: 2009-03-18Bitstream added on 2014-06-13T19:17:32Z : No. of bitstreams: 1
pereira_rp_me_arafo.pdf: 718418 bytes, checksum: e3bb9ad8e88ee0f369f92dd6e3ca7045 (MD5)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
Vários protocolos de desinfecção podem ser usados para romper a cadeia de infecção cruzada entre o consultório odontológico e o laboratório de prótese. A inclusão de agentes antimicrobianos à composição do gesso ou a manipulação do gesso com soluções desinfetantes podem ser usados com esta finalidade. O propósito deste estudo foi avaliar a atividade antimicrobiana de dois agentes desinfetantes (digluconato de clorexidina 2% e cloridrato de clorexidina 98%) incorporados ao gesso IV (FujiRock - GC Europe, Leuven, Bélgica) durante sua manipulação. No teste microbiológico de difusão em Agar foram uti l izados os seguintes microorganismos: Escherichia coli, Staphylococcus aureus, Bacilus subtilis e Candida albicans. Amostras com 5 mm de diâmetro e 3 mm de espessura foram separadas em quatro grupos: 1) gesso manipulado com água destilada esterilizada (controle positivo); 2) discos de papel embebidos com solução de digluconato de clorexidina 2% (controle negativo); 3) gesso manipulado com solução de digluconato de clorexidina 2%; 4) gesso com a incorporação de cloridrato de clorexidina 98% em pó, na proporção de 1% da massa do gesso, e manipulado com água destilada esterilizada. Após 1 hora e 24 horas do vazamento do gesso, as amostras foram posicionadas em placas de Petri com meios de cul tura específicos inoculados com as suspensões microbianas. A atividade antimicrobiana dos desinfetantes foi avaliada pelo diâmetro médio dos halos de inibição do crescimento microbiano. Os valores foram analisados pela ANOVA Aninhada (p<0,05) e teste de Tukey para comparações específicas. Os resultados encontrados demonstraram que os agentes desinfetantes analisados apresentaram atividade antimicrobiana quando misturados ao gesso, com exceção para Candida albicans, na qual não houve efeito da solução de clorexidina nos dois períodos de análise...
Many protocols for disinfection procedures can be used to break the chain of cross-contamination between dental office and dental laboratory. The inclusion of antimicrobial agent to the composition of gypsum or the manipulat ion of gypsum with disinfectant substances can be used to that aim. The purpose of this study was to evaluate the antimicrobial activity of two disinfectant agents (2% chlorhexidine digluconate and 98% chlorhexidine hydrochloride) incorporated into type IV dental stone (FujiRock - GC Europe, Leuven, Belgium) at the time of mixing. The microbiological test used was the Agar diffusion test to the following microorganisms: Escherichia coli, Staphylococcus aureus, Bacilus subtilis and Candida albicans. Samples of 5 mm in diameter and 3 mm in length were separated in four groups: 1) dental stone mixed wi th steri le distilled water (positive control); 2) paper disk soaked wi th solution of 2% chlorhexidine digluconate (negative control); 3) dental stone mixed with solution of 2% chlorhexidine digluconate; 4) dental stone wi th incorporation of chlorhexidine hydrochloride 98% powder, in proportion of 1% of the dental stone mass, and mixed with sterile distilled water. The samples were placed, 1 hour and 24 hours after pouring of dental stone, in Petri plates with specific cul ture medium wich were inoculated with the microbial suspensions. The antimicrobial activity of disinfectant was evaluated by the average diameter of microbial growth inhibi tion zones. The data were analyzed with a Nested ANOVA (p<0,05) and Tukey test for specific comparisons. The disinfectant agents analyzed demonstrated antimicrobial effect against microorganisms used in this study, in exception to Candida albicans, against wich there was not effect from chlorhexidine digluconate at two periods of analysis. Significant difference between disinfectantes were found to all microrganisms... (Complete abstract click electronic access below)
31
Nagano, Yuriko. "Application of molecular techniques in medical microbiology". Thesis, Queen's University Belfast, 2008. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.479415.
Texto completo da fonte
32
Jones, Frances Patricia. "The microbiology of lean and obese soil". Thesis, University of Reading, 2017. http://centaur.reading.ac.uk/69408/.
Texto completo da fonteResumo:
The bacterial genus Bradyrhizobium is biologically important within soils, with different representatives found to perform a range of functions including nitrogen fixation through symbioses, photosynthesis and denitrification. The Highfield experiment at Rothamsted provides an opportunity to study the impact of plants on microbial communities as it has three long-term contrasting regimes; permanent grassland, arable and bare fallow (devoid of plants). The bare fallow plots have a significant reduction in soil carbon and microbial biomass. Bradyrhizobium has been shown by metagenomic studies on soil to be one of the most abundant and active groups including in bare fallow soil indicating that some phenotypes are adapted to survive in the absence of plants. A culture collection was created with isolates obtained from contrasting soil types from Highfield in addition to woodland soil, gorse (Ulex europeaus) and broom (Cytisus scoparius) root nodules. The collection’s phylogeny has been explored by sequencing housekeeping genes to determine whether soil treatment affects the core genome. One grassland and one bare fallow isolate had their genome sequenced and differences have been assessed to establish their potential for a range of functions and to direct future experiments. The functional diversity of the collection has been investigated using carbon metabolism assays to identify key substrates and determine whether the isolates group according to soil treatment. Symbiosis capacity and role in nitrogen cycling has been examined using nodulation tests, anaerobic growth on nitrate and nitrous oxide production and reduction through denitrification. A high level of diversity can be seen throughout the collection with differences being linked to niche adaptation. Understanding more about Bradyrhizobium could give clues on how above ground management impacts a key group within the soil community. Furthermore, the first assembled genomes of two non-symbiotic Bradyrhizobium strains isolated from soil provide an important resource for microbiology and soil ecology.
33
Silva, João Carlos Tenente da. "Huambo Microbiology Laboratory : economical and financial viability". Master's thesis, Instituto Superior de Economia e Gestão, 2016. http://hdl.handle.net/10400.5/11857.
Texto completo da fonteResumo:
Mestrado em FinançasEste trabalho foi realizado no âmbito de um projeto para uma empresa sediada em Huambo, na qual foi pedido uma análise de viabilidade económica e financeira para a construção de um laboratório de microbiologia de alimentos. Esta será a primeira empresa localizada em Huambo, na qual irá testar a qualidade dos produtos importados e exportados em Angola. Numa primeira fase foi estudado o valor inicial para este investimento, a nível de infraestruturas e equipamentos. Para conseguir uma previsão deste investimento, foram analisados alguns laboratórios concorrentes em Portugal, apesar da difícil comparação em termos de dimensão e custos. Este será um investimento realizado exclusivamente através de financiamento bancário. A taxa de juro para este empréstimo foi calculada com base nas taxas de juro aplicadas em casos e valores de financiamento semelhantes. De seguida, foi elaborado uma projeção do volume de negócios baseado na informação recolhida relativamente às importações e exportações neste sector. Com esse volume de negócio, foram calculados todos os custos inerentes ao funcionamento da empresa, como por exemplo, custos fixos e variáveis e custos com salários. Os custos do investimento irão ser depreciados ao longo dos cinco anos previstos. Para melhorar a análise, foram realizados três cenários, de forma, a perceber o quanto poderá influenciar algumas alterações nas previsões. Para perceber a viabilidade económica e financeira deste projeto foi utilizado o método do desconto dos Cash-Flow. Com este método foi também possível obter a taxa interna de rentabilidade e o período no qual o investimento será pago.
This work was carried out for a project in a company based in Huambo, which was asked for an economic and financial viability study for the construction of a food microbiology laboratory. This will be the first company located in Huambo, which will test the quality of imported and exported products in Angola. In a first phase the initial value was studied for this investment, such as buildings, frame-work and equipment. To get the investment’s provision, some competitors’ laboratories were analyzed in Portugal, despite the difficult comparison in terms of size and cost. This will be an investment made exclusively through bank financing. The interest rate for this loan was calculated based on the interest rates applied in similar cases and financing values. Then a turnover projection based on information collected on imports and exports in this sector was prepared. With this turnover, they calculated all the costs of operation of the business, such as fixed and variable costs and wage costs. The investment costs will be depreciated over the five year period. To improve the analysis, there were three scenarios (pessimistic, average and optimistic), in order, to realize how much changes on quantity and costs can influence the forecasts. To realize the economic and financial viability of this project we used the discount method of Cash Flow. With this method it was also possible to obtain the internal rate of return and payback period.
34
Pitt, Sarah Jane. "Managing for quality in clinical microbiology services". Thesis, Liverpool John Moores University, 2001. http://researchonline.ljmu.ac.uk/5526/.
Texto completo da fonteResumo:
The technical quality of the work performed in clinical microbiology laboratories is regularly monitored, by external and internal schemes. Among the factors which might affect quality, attitudes of the laboratory staff are rarely considered. In this study, three concepts recognised by occupational psychologists as being important in the work place, Job Satisfaction, Commitment and Climate, were measured among microbiology biomedical scientists (BMSs) in the United Kingdom A self-report questionnaire was developed through preliminary interviews and two pilot studies. The perceptions of Job Satisfaction, Commitment (to both Profession and Organisation) and Climate were measured using established models from the occupational psychology literature. Three scales were devised specifically during this study to assess an individual BMS's perceptions of the standard of their own performance, the attitudes of their colleagues towards their work and the quality within their laboratory. A fourth measure was developed which collated all the ways that technical quality in clinical microbiology laboratories is currently measured in the UK into one scale. A total of 2415 questionnaires were posted to BMSs employed in National Health Service, Public Health Laboratory Service, Privately funded and University laboratories between November 1998 and February 1999. By March 1999,931 replies had been received, a response rate of 39%. BMSs reported lower Job Satisfaction than Medical Laboratory Technologists (the equivalent profession) in the United States. The results supported Meyer and Allen's (1991) three-component model of commitment and showed that BMSs experienced Professional Commitment more strongly than Organisational Commitment. An eight dimension model of Climate was developed, for clinical microbiology staff, from Newman's (1977) Perceived Work Environment scale. BMSs' perceptions of Individual Climate were affected by a number of demographic factors, but the most important was the size of the laboratory. The optimal number of people in a clinical microbiology department for positive Individual Climate was found to be less than 30. Affective Commitment to the Profession was the component of Commitment which most strongly influenced technical quality, through its positive relationship with an individual BMS's performance at work. Through aggregation of Climate scores for selected laboratories, it was shown that Laboratory Climate correlated positively with technical quality. From BMSs' perceptions of their laboratory's quality, a scale to assess `A Climate for Laboratory Quality' was developed. There was a strong positive relationship between `A Climate for Laboratory Quality' and a department's score on the measure of technical quality. Interviews with staff in four clinical microbiology laboratories supported the questionnaire findings with respect to Laboratory Climate. Qualitative data collected from a representative group of users of each of the four microbiology services showed that users' main concern was rapid turnaround time for results. Comments also highlighted the need for more effective communication between laboratory staff their colleagues working directly with patients.
35
Yuan, Heyang. "Bioelectrochemical Systems: Microbiology, Catalysts, Processes and Applications". Diss., Virginia Tech, 2017. http://hdl.handle.net/10919/79910.
Texto completo da fonteResumo:
The treatment of water and wastewater is energy intensive, and there is an urgent need to develop new approaches to address the water-energy challenges. Bioelectrochemical systems (BES) are energy-efficient technologies that can treat wastewater and simultaneously achieve multiple functions such as energy generation, hydrogen production and/or desalination. The objectives of this dissertation are to understand the fundamental microbiology of BES, develop cost-effective cathode catalysts, optimize the process engineering and identify the application niches. It has been shown in Chapter 2 that electrochemically active bacteria can take advantage of shuttle-mediated EET and create optimal anode salinities for their dominance. A novel statistical model has been developed based on the taxonomic data to understand and predict functional dynamics and current production. In Chapter 3, 4 and 5, three cathode catalyst (i.e., N- and S- co-doped porous carbon nanosheets, N-doped bamboo-like CNTs and MoS2 coated on CNTs) have been synthesized and showed effective catalysis of oxygen reduction reaction or hydrogen evolution reaction in BES. Chapter 6, 7 and 8 have demonstrated how BES can be combined with forward osmosis to enhance desalination or achieve self-powered hydrogen production. Mathematical models have been developed to predict the performance of the integrated systems. In Chapter 9, BES have been used as a research platform to understand the fate and removal of antibiotic resistant genes under anaerobic conditions. The studies in this dissertation have collectively demonstrated that BES may hold great promise for energy-efficient water and wastewater treatment.Ph. D.
36
Липовська, Вікторія Вікторівна, Виктория Викторовна Липовская, Viktoriia Viktorivna Lypovska, Неля Георгіївна Горобченко, Неля Георгиевна Горобченко, Nelia Heorhiivna Horobchenko e D. M. Horobchenko. "Robert Koch - the father of clinical microbiology". Thesis, Видавництво СумДУ, 2012. http://essuir.sumdu.edu.ua/handle/123456789/27500.
Texto completo da fonte
37
Dharod, Meghna. "Diabetic foot : microbiology, pathogenesis and glycan studies". Thesis, University of Westminster, 2010. https://westminsterresearch.westminster.ac.uk/item/9057z/diabetic-foot-microbiology-pathogenesis-and-glycan-studies.
Texto completo da fonteResumo:
Complications of type 2 diabetes mellitus are one of the major causes of morbidity and mortality around the world. Diabetic foot infections remain one of the major complications leading to a leg loss every 3 seconds due to amputations causing mental trauma and distress. In diabetic foot ulcers aerobes, anaerobes and fungus often interact with each other and form biofilms which is difficult to treat, enhancing antimicrobial resistance and lead to a non-healing ulcer. Co-existing peripheral vascular disease and neuropathy exacerbate the problems. In T2DM patients’ minor cuts and wounds, often lead to hard to treat and chronic ulcers which can worsen to gangrene formation which may lead to osteomyelitis compromising the mechanics of the foot. It is necessary to identify the virulence factors of these clinically significant microbes and to identify the resistance patterns regularly to limit the antibiotic usage and target to the specific organisms. A Cohort studies were carried out in India and in the UK to identify the risk factors among the diabetic foot patients along with their microbial aetiology and antibiotic resistance patterns from the tissue and pus samples. This part of the research has shown the presence of mixed cultures mainly from the Indian diabetic foot ulcer specimens with higher percentages of anaerobes than aerobes. Multi-drug resistant organisms were one of the peculiar characteristics of the diabetic foot ulcer profiles of Indian patients. As compared to the Indian patients, UK patients had few resistant organisms and the patients admitted to hospitals in India were at the last stage of foot ulcers whereas in the UK, surveillance and preventative strategies allow early detection and intervention. Currently there is a lack of rapid, robust and an inexpensive diagnostic method for the rapid typing and identification of clinically significant anaerobes. Another part of the research focussed on utilising the glycan-lectin interactions by developing a simple enzyme linked lectin sorbent assay by employing biotinylated lectins to develop to an enzyme linked lectin sorbent assay (ELLA) on whole cells, Proteinase K treated cells and glycolipids of clinically significant aerobes and anaerobes. This study is concluded by utilising the glycan-lectin interactions and to develop a rapid typing method for clinically significant Methicillin resistant and sensitive Staphylococcus aureus and epidermidis species. The rapid identification of anaerobes and typing of Peptostreptococcus species was also by facilitated by the developed ELLA method. Finegoldia magna is one of the most significant anaerobes from soft tissue infections and the Gas Chromatography – mass spectrometry (GC-MS) of the glycolipids of Finegoldia magna on composition analysis using show the presence of sialic acid which could be involved in pathogenesis. This sugar may be one of virulence factor employed by this organism in either attachment to the host or to other organisms.
38
Guermonprez, Cyprien. "Droplet-based Microfluidic Platform for Quantitative Microbiology". Thesis, Université Paris-Saclay (ComUE), 2016. http://www.theses.fr/2016SACLX106/document.
Texto completo da fonteResumo:
Développement d'une plateforme microfluidique pour la microbiologie quantitative. La plateforme permet la culture de milliers de colonies en parallèle dans des micro-gouttes. L'utilisation de tableau statique pour stocker les gouttes permet non seulement leur observation dans le temps pour des analyses dynamiques mais également la récupération de n'importe quelle goutte pour des études complémentaires. Nous avons également développé un outil permettant de soumettre les gouttes à des gradients chimiques directement sur la plateforme dont nous présentons les mécanismes physiques. Nous avons développé un software d'analyse des données générées par la plateforme pour l'étude de modèles de croissance bactérienne ainsi que l'impact des antibiotiques sur leur proliférationDevelopment of a microfluidic chip for quantitative microbiology. The chip allow for parallel culture of thousands bacterial colonies in micro-droplets stored in static array. The 2D-array enable not only the visualisation of each colonies in timelapse experiment but also the extraction of any of them out of the chip at any time for further analysis (PCR, re-culture,...). The platform is adaptable to a concentration gradient producer, for which we present the physical understanding of working mechanism, that can apply different chemical environments to each colony. We developed in parallel a software that perform the analysis of the data generated by the platform to adress bacteria growth studies as well as the impact of antibiotics on bacteria proliferation
39
TESTI, DAVIDE. "Periodontal microbiology: new findings about oral microbiota". Doctoral thesis, Università degli Studi di Roma "Tor Vergata", 2014. http://hdl.handle.net/2108/203046.
Texto completo da fonte
40
Garcia, Mendez Karellen Beren. "Infection of human placental cells by Brucella". Thesis, Montpellier, 2017. http://www.theses.fr/2017MONTT065.
Texto completo da fonteResumo:
Les Brucella sont des bactéries intracellulaires responsables de la brucellose, une zoonose mondiale qui cause des avortements chez les animaux, entrainant d'énormes pertes économiques dans les élevages, et des problèmes de santé de longue durée chez l'Homme. Contrairement aux animaux, il existait jusqu’à présent peu de preuves que les infections à Brucella pouvaient causer des complications obstétriques chez la femme. Des récentes études épidémiologiques ont cependant démontré une augmentation significative des risques de complications (fausses couches, mort in utéro, accouchement prématuré) chez les femmes enceintes infectées par Brucella. De plus, il a été montré que plusieurs espèces zoonotiques de Brucella sont capables d’infecter des cytotrophoblastes (CTB) et des trophoblastes extravilleux (EVT) humains, deux types de cellules ayant des fonctions immunitaires et hormonales essentielles pendant le développement du placenta. Dans ce travail, nous avons étudié les conséquences de l’infection des trophoblastes humains par Brucella, du côté du pathogène mais aussi du côté de l’hôte. Nous avons évalué le comportement intracellulaire de différentes souches de Brucella, représentant différentes espèces, hôtes ou symptômes associés. Nous n'avons trouvé aucune corrélation entre la capacité de réplication dans les trophoblastes et l’association des souches avec des complications obstétricales chez leur hôte respectif. Nous nous sommes également intéressé à des souches récemment isolées chez des babouins, après une infection placentaire ayant causé la mort in utéro de leur fœtus. Nous avons montré que ces souches sont capables d’infecter les trophoblastes humains et affectent certaines de leurs propriétés qui sont essentielles lors du développement placentaire. Nous avons également commencé à caractériser des structures intracellulaires atypiques dans lesquelles Brucella semble pouvoir survivre dans certains trophoblastes. Du côté hôte, nous avons analysé le rôle de la protéine eucaryote CD98hc dans l'infection les trophoblastes. Nous avons montré que CD98hc est importante pour l'infection des trophoblastes humains par Brucella, comme cela avait été montré précédemment dans d'autres types cellulaires, et que l’infection modifie le niveau de cette protéine dans les trophoblastes. L'infection des trophoblastes humains par Brucella pourrait donc altérer leurs fonctions au cours du développement placentaire, entraînant ainsi des complications pendant la grossesse.Les résultats obtenus dans ce travail contribuent à une meilleure compréhension des mécanismes pouvant causer des complications obstétricales chez la femme enceinte infectée par brucella et fournissent des informations importantes pour la prise en charge clinique de la brucellose pendant la grossesseBrucella are intracellular bacteria responsible for brucellosis, a worldwide zoonotic disease associated with infectious abortions in animals, which causes huge economical losses in the livestock industry and long lasting health problems in humans. In contrast to animals, evidence of Brucella infections cause obstetric complications in humans is scarce. However, epidemiological studies have shown significant increases in the risk of adverse pregnancy outcomes (miscarriage, stillbirth, preterm delivery) in pregnant women infected with Brucella. Moreover, several zoonotic Brucella species were shown to infect efficiently human cytotrophoblasts (CTB) and extravillous trophoblasts (EVT), two types of cells with essential immune and hormonal functions during placental development. In the present study, we studied the effect of Brucella infection in human trophoblasts, from both the bacterial and the host sides. We evaluated the intracellular behavior of different Brucella strains, representing different species, hosts or associated symptoms. We found no correlation between the bacterial replication rate in trophoblasts and whether the strains were associated with pregnancy complications in their respective host. Importantly, we show that strains isolated from female baboons after stillbirth can infect human trophoblasts and affect some of their properties that are essential during placental development. We also started the characterization of atypical intracellular structures in which Brucella seem to be able to survive in certain types of trophoblasts. From the host side, we analyzed the role of the eukaryotic protein CD98hc in trophoblast infection. We found that CD98hc is important for infection of trophoblasts by Brucella, as shown previously in other cell types, and that infection affects the level of the protein in trophoblasts. Infection of human trophoblasts by Brucella could thus affect their function during placental development, leading to complications in pregnancy.The results obtained in this work contribute to a better understanding of the mechanisms that could lead to obstetric complications in Brucella infected pregnant women and provide important information for the clinical management of brucellosis during pregnancy
41
Jeronymo, Ana Beatriz de Oliveira [UNESP]. "Avaliação do potencial probiótico de bactérias acidoláticas produtoras de substância antimicrobiana isoladas de mussarela de búfala". Universidade Estadual Paulista (UNESP), 2013. http://hdl.handle.net/11449/94803.
Texto completo da fonteResumo:
Made available in DSpace on 2014-06-11T19:27:20Z (GMT). No. of bitstreams: 0
Previous issue date: 2013-02-18Bitstream added on 2014-06-13T19:55:49Z : No. of bitstreams: 1
jeronymo_abo_me_sjrp.pdf: 527948 bytes, checksum: 021b8dab7a3a66a58891530aa01bb6bb (MD5)As bactérias acidoláticas (BAL) constituem um grupo de micro-organismos heterogêneos Gram positivos, catalase negativos, anaeróbios facultativos e produtores de ácido lático . Estas bactérias têm despertado grande interesse na indústria de alimentos devido à produção de substâncias antimicrobianas, tais como as bacteriocinas. Estas substâncias têm a capacidade de reduzir a contaminação por patógenos e deteriorantes em alimentos, resultando em produtos com maior vida de prateleira. Outra característica importante presente em algumas linhagens de BAL é apresentar efeitos benéficos aos consumidores. O objetivo desse trabalho foi avaliar a produção de substâncias antimicrobianas por 38 cepas de BAL isoladas de mussarela de búfala, caracterizar as bacteriocinas quanto ao espectro de ação, estabilidade em diferentes pH, estabilidade térmica e resistência a agentes químicos. Para as cepas produtoras de bacteriocina também foi avaliado o efeito inibitório de L isteria monocytogenes ATCC 7644 em leite UHT integral e leite UHT desnat ado, e avaliar o potencial probiótico . Das trinta e oito cepas de BAL isoladas de mussarela de búfala, oito foram produtoras de substância antimicrobiana. Essas cepas foram identificadas como: Lactobacillus delbrueckii subsp. bulgaricus (cepa 13) , Lactobac illus casei ( cepa 24), L eu conostoc citreum (cepa 28 ) e Leuconostoc mesenteroides subsp. mesenteroides (cepas 26, 30 e 32). O estudo da natureza do composto confirmou que os compostos microbianos são bacteriocinas. As bacteriocinas produzidas pel as cepas 26 e 32 não foram afetadas pelo calor , extremos d e pH e diferentes detergentes. As cepas 26 e 32 reduziram a população do micro -organismo patogênico L. monocytogenes ATCC 7644 quando inoculadas em leite UHT integral e leite UHT desnatado, apresentando um efeito...
Lactic acid bacteria (LAB) ar e a heterogeneous group of Gram-positive microorganisms, catalase negative, facultative anaerobes and lactic acid producers. These bacteria have attracted great attention from the food industry due to the production of antimicrobial substances such as bacteriocins. These substances have the ability to reduce food spoilage and contamination by pathogens, resulting in products with longer shelf life. Another important feature present in some strains of LAB is to provide benefits to consumers. The aim of this study is to evaluate the production of antimicrobial substances by 38 LAB strains isolated from water-buffalo mozzarella cheese, and characterize the spectrum of activity of the bacteriocins, stability at different pH values, thermal stability and its resistance to chemicals. The bacteriocin-producing strains were also evaluated regarding the inhibitory effect on L. monocytogenes ATCC 7644 in UHT whole milk and UHT skim milk, and the probiotic properties. Six of the thirty-eight strains of LAB isolated from water-buffalo mozzarella cheese produce d antimicrobial substances. These strains were identified as L actobacillus delbrueckii subsp. bulgaricus (strain 13), Lactobacillus casei (strain 24), Leuconostoc citreum (strain 28) and Leuconostoc mesenteroides subsp. mesenteroides (strains 26, 30 and 32). The study of the nature of the antimicrobial compounds confirmed that they are bacteriocins. The bacter iocins produced by strains 26 and 32 were not affected by heat, extreme pH and different detergents. Strains 26 and 32 reduced the pathogenic microorganism Listeria monocytogenes ATCC 7644 population when inoculated in UHT whole and UHT skim milk, presenting a bacteriostatic effect. Strains 1 3, 24, 28 and 32 survived during the passage through the simulated gastrointestinal tract when inoculated... (Complete abstract click electronic access below)
42
Jeronymo, Ana Beatriz de Oliveira. "Avaliação do potencial probiótico de bactérias acidoláticas produtoras de substância antimicrobiana isoladas de mussarela de búfala /". São José do Rio Preto, 2013. http://hdl.handle.net/11449/94803.
Texto completo da fonteResumo:
Orientador: Ana Lúcia Barretto PennaBanca: Svetoslav Dimitrov Todorov
Banca: Mara Corrêa Lelles Nogueira
Resumo: As bactérias acidoláticas (BAL) constituem um grupo de micro-organismos heterogêneos Gram positivos, catalase negativos, anaeróbios facultativos e produtores de ácido lático . Estas bactérias têm despertado grande interesse na indústria de alimentos devido à produção de substâncias antimicrobianas, tais como as bacteriocinas. Estas substâncias têm a capacidade de reduzir a contaminação por patógenos e deteriorantes em alimentos, resultando em produtos com maior vida de prateleira. Outra característica importante presente em algumas linhagens de BAL é apresentar efeitos benéficos aos consumidores. O objetivo desse trabalho foi avaliar a produção de substâncias antimicrobianas por 38 cepas de BAL isoladas de mussarela de búfala, caracterizar as bacteriocinas quanto ao espectro de ação, estabilidade em diferentes pH, estabilidade térmica e resistência a agentes químicos. Para as cepas produtoras de bacteriocina também foi avaliado o efeito inibitório de L isteria monocytogenes ATCC 7644 em leite UHT integral e leite UHT desnat ado, e avaliar o potencial probiótico . Das trinta e oito cepas de BAL isoladas de mussarela de búfala, oito foram produtoras de substância antimicrobiana. Essas cepas foram identificadas como: Lactobacillus delbrueckii subsp. bulgaricus (cepa 13) , Lactobac illus casei ( cepa 24), L eu conostoc citreum (cepa 28 ) e Leuconostoc mesenteroides subsp. mesenteroides (cepas 26, 30 e 32). O estudo da natureza do composto confirmou que os compostos microbianos são bacteriocinas. As bacteriocinas produzidas pel as cepas 26 e 32 não foram afetadas pelo calor , extremos d e pH e diferentes detergentes. As cepas 26 e 32 reduziram a população do micro -organismo patogênico L. monocytogenes ATCC 7644 quando inoculadas em leite UHT integral e leite UHT desnatado, apresentando um efeito... (Resumo completo, clicar acesso eletrônico abaixo)
Abstract: Lactic acid bacteria (LAB) ar e a heterogeneous group of Gram-positive microorganisms, catalase negative, facultative anaerobes and lactic acid producers. These bacteria have attracted great attention from the food industry due to the production of antimicrobial substances such as bacteriocins. These substances have the ability to reduce food spoilage and contamination by pathogens, resulting in products with longer shelf life. Another important feature present in some strains of LAB is to provide benefits to consumers. The aim of this study is to evaluate the production of antimicrobial substances by 38 LAB strains isolated from water-buffalo mozzarella cheese, and characterize the spectrum of activity of the bacteriocins, stability at different pH values, thermal stability and its resistance to chemicals. The bacteriocin-producing strains were also evaluated regarding the inhibitory effect on L. monocytogenes ATCC 7644 in UHT whole milk and UHT skim milk, and the probiotic properties. Six of the thirty-eight strains of LAB isolated from water-buffalo mozzarella cheese produce d antimicrobial substances. These strains were identified as L actobacillus delbrueckii subsp. bulgaricus (strain 13), Lactobacillus casei (strain 24), Leuconostoc citreum (strain 28) and Leuconostoc mesenteroides subsp. mesenteroides (strains 26, 30 and 32). The study of the nature of the antimicrobial compounds confirmed that they are bacteriocins. The bacter iocins produced by strains 26 and 32 were not affected by heat, extreme pH and different detergents. Strains 26 and 32 reduced the pathogenic microorganism Listeria monocytogenes ATCC 7644 population when inoculated in UHT whole and UHT skim milk, presenting a bacteriostatic effect. Strains 1 3, 24, 28 and 32 survived during the passage through the simulated gastrointestinal tract when inoculated... (Complete abstract click electronic access below)
Mestre
43
Paradela, Gomes Cláudia Sofia. "Antimicrobial resistance and new insights in the diagnosis of Carrión's Disease". Doctoral thesis, Universitat de Barcelona, 2016. http://hdl.handle.net/10803/401758.
Texto completo da fonteResumo:
Carrión's disease is an overlooked disease restricted to the poorest areas of the Andes, with only a few research groups working in this field around the world. Until recently, it was thought that Carrion's disease met the most relevant criteria for being eradicated, but before that happens a number of issues need to be addressed. One of the problems is the lack of well-defined effective treatment program. Both in vitro antimicrobial resistance studies and clinical trials are needed to determine the best treatment approaches. On the other hand, and perhaps the most urgent need, it is necessity to have an easy way to make the correct diagnosis. New immunological studies will help to identify new molecules with diagnostic potential.
The results of this thesis have been separated into 2 different aspects of Carrión's disease; On one hand, antimicrobial resistance (Chapter I) and, on the other hand, the diagnosis and characterization of clinical samples (Chapter II). Chapter I describes a study on resistance mechanisms developed in the presence of the 4 most common antibiotics used in the treatment of Carrion's disease. The ability of Bartonella bacilliformis to become resistant to the main antibiotics used to treat Carrión's disease is evidenced both by the development of antibiotic target alterations and by the overexpression of expulsion pumps. However, total or partial reversion of acquired resistance suggests the existence of a high biological cost derived from the selection of antimicrobial resistance. These instability of the acquired antibiotic resistance may underlie the lack of antibiotic-resistant clinical isolates and the high frequency of microbiological failures during antibiotic treatments. Although studies of mutants obtained in vitro can not be transferred directly to the community, chloramphenicol appears to be the best treatment option in vitro.
Chapter 2 analyzes several aspects of the diagnosis of Carrion's disease that are addressed in 3 studies. In the first study, samples obtained from patients of an suspected Oroya fever outbreak were molecularly characterized. However, we propose that this outbreak was erroneously attributed to B. bacilliformis and our results suggest that the causative agent was Sphingomonas faeni. As far as we know, this was the first reported outbreak caused by Sphingomonas spp. acquired in the community, making clear the need to develop diagnostic techniques that can be implemented in endemic areas. In a second study we evaluated the limit of detection of several PCR approaches to detect B. bacilliformis from blood. It seems that the sensitivity of these techniques could allow the diagnosis of acute cases of Carrion's disease, but its
applicability to detect healthy carriers or acute cases with low bacteraemia remains unclear. In this article we propose the concomitant use of the 3 PCR approaches in combination with the clinical information. Finally, in the third study of this chapter the objective was the identification and characterization of immunogenic candidates of B. bacilliformis that may in the future be used in a rapid diagnostic tool. Four immunogenic B. bacilliformis candidates were selected: 2 proteins were identified with an anti-human IgM secondary antibody (Pap31 and SCS-α) and another 2 with anti- human IgG secondary antibody (GroEL and SCS-β).
The design of treatment schemes that minimize resistance selection along with the development of diagnostic techniques that can be implemented in rural and isolated areas is essential for the control, elimination and eradication of Carrion's disease.La enfermedad de Carrión es una enfermedad desatendida restringida a las zonas más pobres de la región Andina. Uno de los problemas es la falta de programas de tratamiento eficaces bien definidos. Por otro lado, y quizás sea la necesidad más imperiosa, es preciso tener una manera fácil de realizar el diagnóstico. Nuevos estudios inmunológicos ayudarán a identificar nuevas moléculas con potencial diagnóstico. Los resultados de esta tesis han sido separados en 2 aspectos diferentes de la enfermedad de Carrión; la resistencia a los antimicrobianos (Capítulo I) y el diagnóstico y caracterización de muestras clínicas (Capítulo II). El capítulo I describe un estudio sobre los mecanismos de resistencia desarrollados en presencia de los 4 antibióticos más comunmente utilizados en el tratamiento de la enfermedad de Carrión, evidenciándose la capacidad de Bartonella bacilliformis de volverse resistente a estos antibióticos, tanto por el desarrollo de alteraciones en sus dianas, como por la sobreexpresión de bombas de expulsión. El capítulo 2 analiza aspectos del diagnostico de la enfermedad de Carrión que se abordan en 3 estudios. En el primero se caracterizan molecularmente muestras obtenidas de pacientes de un supuesto brote de fiebre de Oroya. Sin embargo, proponemos que este brote se atribuyó erróneamente a B. bacilliformis sugieriéndose que el agente causante fue Sphingomonas faeni. En el segundo hemos evaluado el límite de detección de varios esquemas de PCR para detectar B. bacilliformis. Parece que la sensibilidad de estas técnicas podría permitir el diagnóstico de casos agudos de la enfermedad de Carrión, pero su aplicabilidad para detectar a los portadores sanos o con una baja bacteriemia sigue sin estar clara. Por fin, en el tercer estudio de este capítulo el objetivo fue la identificación y caracterización de candidatos inmunogénicos de B. bacilliformis que puedan en un futuro ser utilizados en una herramienta de diagnostico rápida. Se identificaron 4 proteínas inmunogénicas: Pap31, GroEL, SCS-α y SCS-β. El diseño de esquemas de tratamiento que minimicen la selección de resistencia junto con el desarrollo de técnicas de diagnóstico que puedan ser implementadas en zonas rurales es esencial para el control y eliminación de la enfermedad de Carrión.
44
Planell, Mas Elena de. "Verrugas plantares: caracterización de los virus causales y aplicación del láser 1064 nm a su tratamiento". Doctoral thesis, Universitat de Barcelona, 2016. http://hdl.handle.net/10803/402516.
Texto completo da fonteResumo:
INTRODUCCIÓN:
Las verrugas plantares están provocadas por el virus del papilloma humano (VPH). Se han descrito diferentes genotipos asociados a estas lesiones si bien existen pocos estudios centrados exclusivamente en los genotipos de las verrugas plantares.
El diagnóstico generalmente es clínico, aunque actualmente existen métodos diagnósticos basados en la detección del ADN viral como es el caso de la PCR (polymerase chain reaction). Las modalidades de tratamiento de las verrugas son muchas. Incluyen tratamientos tópicos, crioterapia, quirúrgicos, infiltraciones intralesionales de citotóxicos y la posibilidad de tratamientos combinados. El tratamiento de las verrugas mediante láser se basa en la elevación exógena de la temperatura del tejido (hipertermia local), ya que está comprobado que el tejido infectado es más sensible a los efectos de la temperatura elevada que el tejido normal. En esta tesis se identifican los genotipos del VPH de las verrugas plantares, y se describe su relación con las características demográficas y clínicas de los pacientes. También se evalúa la eficacia de su tratamiento mediante el láser de 1064 nm de longitud de onda, valorando su tiempo de curación así como la tolerabilidad del tratamiento en estudio.
MATERIAL Y MÉTODOS:
La población de estudio fueron 72 pacientes diagnosticados de verrugas plantares de la Unitat de Láser del Hospital Podològico de la Universitat de Barcelona. Las muestras fueron recogidas previo corte laminar de la hiperqueratosis profunda de la verruga plantar, mediante bisturí para realizar la extracción del DNA. Se realizó la amplifición de una región conservada del gen L1 de VPH mediante La reacción en cadena de la polimerasa para secuenciar los amplicones del DNA e identificar los tipos de VPH.
Se determinaron unos parámetros finales de pulso, pausa, potencia y fluencia del láser finalmente que fueron objeto de estudio en la valoración de la efectividad de tratamiento óptima y evitando el dolor para el paciente en el tratamiento de las verrugas plantares.
RESULTADOS:
Los genotipos más prevalentes entre las 105 muestras de verrugas plantares analizadas fueron VPH- 57 (37.1%), VPH-27 (23.8%), VPH-1a (20.9%), VPH-2 (15.2%) y VPH-65 (2.8%). La mayoría de los
pacientes (78%) presentaron solo una verruga plantar, mientras que en el 22,2% de los pacientes se detectaron múltiples verrugas. Un paciente con múltiples verrugas presentava dos generos de VPH diferentes, lo que sugiere la diseminación de las verrugas por autoinoculación además de la infección de novo. No se hallaron diferencias significativas entre el número de verrugas en dedos, mediopie y retropie. El género más prevalente en todas lás zonas fue el género alfa.
En el tratamiento con láser de 1064 nm de longitud de onda, aplicando los parámetros finales, el 26,66% de las verrugas con un diámetro igual o inferior a 4 mms sólo precisó de una sesión de láser para su eliminación, el mismo porcentaje precisó de dos sesiones, el 40% de estas verrugas precisaron de 3 sesiones de láser y el 6,68% de cuatro sesiones. El 11,53% de las verrugas con un diámetro superior a 4 mm sólo precisó de una sesión de láser para su eliminación, el 23,07% de estas verrugas precisaron de dos sesiones, el mismo porcentaje precisó de tres sesiones y el 19,23% de cinco sesiones.
CONCLUSIONES:
La determinación de las secuencias de los fragmentos amplificados mostró que el género alfa, con el genotipo 27 y 57 fue el más prevalente en las verrugas plantares. Los individuos con múltiples verrugas plantares pueden presentar vía de transmisión tanto por autoinoculación como por infección ex-novo. La localización de las verrugas en la planta del pie es coincidente con los puntos de máxima carga durante la deambulación, tanto en superficie como en tiempo de apoyo. El género alfa, es el más coincidente con este patrón de apoyo. El láser de 1064 nm, con los parámetros propuestos en el estudio, ha demostrado su eficacia en el tratamiento de las verrugas plantares, con una media de 2 o 3 sesiones y sin que éste produzca un algia intolerable para el paciente.INTRODUCTION: Plantar warts, caused by human papillomaviruses (HPVs), are benign cutaneous tumors. In this study, we aimed to identify the HPV genotypes of plantar warts and explore their relation to demographic and clinical characteristics of patients. We also evaluated the efficacy of 1064 nm laser in the treatment of plantar warts as well as the number of laser sessions and discomfort experienced by patients. MATERIAL AND METHODS: A total of 72 patients diagnosed with plantar warts were recruited at the Laser unit at Podiatric Hospital, University of Barcelona, Spain. Laminar sections of warts were collected, DNA of samples was extracted and HPV types were identified. To assess the effectiveness of the laser treatment, operating mode parameters such as pulse duration, pause, power and fluence were optimized. RESULTS: The most prevalent genotypes detected among the 105 analyzed plantar warts were HPV-57 (37.1%), HPV-27 (23.8%), HPV-1a (20.9%), HPV-2 (15.2%) and HPV-65 (2.8%). The majority of patients (78%) presented one single plantar wart, whereas multiple warts were detected in 22.2% of patients. One patient with multiple warts presented HPV types from two different genera, suggesting the spread of warts by self-inoculation as well as by de novo infection. No significant differences between the number of warts in toes, midfoot and heel were found. The most prevalent HPV types detected in all areas belonged to the alpha genus. Laser treatment was applied using optimized parameters: 26.7% of warts with a diameter ≤4 mm required only one laser session for removal, 26.7% needed two sessions, 40.0% required 3 laser sessions and 6.7% four sessions; 11.5% of warts with a diameter >4 mm required only one laser session for removal, 23.1% required two sessions, 23.1% required three sessions and 19.2% five sessions. CONCLUSIONS: This work provides new insight on plantar warts and their associated HPV genotypes, and evidences the usefulness and reliability of both the sample collection procedure and the PCR method used for HPV detection and typing. The parameters used with 1064nm laser show a safe and effective treatment for plantar warts. The average number of treatments was 2-3 sessions, causing minimal discomfort to patients.
45
Abreu, Catherine Simões de. "Áreas limpas: estudo de correlação entre partículas viáveis e não viáveis". Universidade de São Paulo, 1999. http://www.teses.usp.br/teses/disponiveis/9/9139/tde-14062016-181645/.
Texto completo da fonteResumo:
Este trabalho consiste em um estudo sobre monitoramento ambiental de áreas limpas. Os parâmetros comparados foram partículas não viáveis de 0,5 e 5,0 µm, contaminação do ambiente (UFC do ar) e de superfícies (Rodac®). Procedeu-se ao estudo em áreas de manipulação crítica (Classe A). Nestas áreas, a amostragem foi feita em situações de repouso e dinâmica, antes e após sanitização, e em etapas de certificação e rotina. Os dados de literatura indicam que os parâmetros não são particularmente dependentes do lay out ou classificação das áreas, mas sim do seu uso e do comportamento dos operadores. As conclusões foram positivas quanto a correlação entre diferentes locais de amostragem, para partículas não viáveis de 0,5 e 5,0 µm, e ausência deste tipo de correlação em posições em fluxo laminar. Também, os valores de correlação foram quase sempre decrescentes com a maior limpeza do ambiente. Os microrganismos mais frequentemente isolados, nas áreas A2., A3 e A4 foram Bacillus sp, Staphylococcus sp e Corynebacterium sp.This paper represents a study about environmental monitoring data for cleanrooms. The parameters that were compared are: total airborne particles of 0.,5 and 5.0 µm, airbome colony forming units (CFU\'s) and CFU\'s on surfaees (Rodac®). Most attention was paid to areas where critical handling is performed (class A areas). In these areas sampling was performed \"at rest\" and \"dynamic\" conditions, before and after sanitization and during certification and routine steps. These data indicates that the parameters are not particularly dependent upon the lay out or classification of areas, but rather on the use of the areas, and how the operators behave in them. Evaluating the data, the conclusion was about a correlation among different sampling places, for total airborne particles of 0.,5 and 5.0 µm, and absence of this kind of correlation in laminar flows positions. Also, correlation values were always increasing with the cleanless of the environment. The microorganisms most frequently isolated in areas A2, A3 and A4 were Bacillus sp, Staphylococcus sp and Corynebacterium sp.
46
Ciesielski, Francisco Isaak Nícolas [UNESP]. "Microrganismos oportunistas e exógenos na microbiota bucal de pacientes oncológicos submetidos à radioterapia de cabeça e pescoço". Universidade Estadual Paulista (UNESP), 2010. http://hdl.handle.net/11449/91426.
Texto completo da fonteResumo:
Made available in DSpace on 2014-06-11T19:25:20Z (GMT). No. of bitstreams: 0
Previous issue date: 2010-02-08Bitstream added on 2014-06-13T18:53:14Z : No. of bitstreams: 1
ciesielski_fin_me_araca.pdf: 340364 bytes, checksum: 27a652e37436beb5112aa9fdd7fb42ce (MD5)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
O objetivo deste estudo foi avaliar a ocorrência de microrganismos exógenos e oportunistas (bactérias entéricas, pseudomonados, leveduras e Helicobacter pylori) na cavidade bucal de pacientes submetidos à radioterapia para tratamento de câncer de cabeça e pescoço. Cincoenta pacientes que iria receber radioterapia foram examinados antes, durante e 30 dias após radioterapia. Amostras de saliva, mucosa e biofilme foram coletadas e os microrganismos foram detectados por cultura e Reação em Cadeia da Polimerase (PCR). Candida albicans, C. tropicalis, C. krusei, C. glabrata e C. parapsilosis foram as leveduras mais prevalentes nos pacientes submetidos a radioterapia. Gêneros Citrobacter, Enterobacter, Enterococcus, Klebsiella, Proteus, e Pseudomonas forma as bactérias mais frequentemente cultivadas. As bactérias alvo foram cultivadas de 77.8% dos pacientes edêntulos e 46.9% dos pacientes dentados 30 dias após a radioterapia. Por PCR, estes microrganismos foram detectados em todos os pacientes edêntulos e 78.1% dos pacientes dentados. Bactérias não orais e espécies de Cândida foram mais prevalentes nestes pacientes. Modificações no meio ambiente oral devido a radioterapia parecem facilitar a colonização por estes microrganismos.
The aim of this study was to evaluate the occurrence of opportunistic and exogenous microrganisms (enteric bacteria, pseudomonads, yeasts and Helicobacter pylori) in the oral cavity of patients undergoing radiotherapy (RT) for treatment of head and neck cancer. Fifty patients receiving RT were examined before, during and 30 days after RT. Saliva, mucosa, and biofilm samples were collected and microorganisms were detected by culture and Polymerase Chain Reaction (PCR). Candida albicans, C. tropicalis, C. krusei, C. glabrata and C. parapsilosis were the most prevalent yeasts in patients submitted to RT. Genera Citrobacter, Enterobacter, Enterococcus, Klebsiella, Proteus, and Pseudomonas were the most frequently cultivated bacteria. Targeted bacteria were cultivated from 77.8% edentulous and 46.9% dentate patients 30 days after RT. By PCR, these microorganisms were detected from all edentulous patients and from 78.1% of dentate patients. Non-oral bacteria and Candida species were prevalent in these patients. Modifications of the oral environment due to RT seem to facilitate the colonization of these microorganisms.
47
Vieira, Narciso Almeida [UNESP]. "Microbiota intestinal de crianças com anomalias craniofaciais atendidas em um hospital especializado". Universidade Estadual Paulista (UNESP), 2009. http://hdl.handle.net/11449/101491.
Texto completo da fonteResumo:
Made available in DSpace on 2014-06-11T19:31:29Z (GMT). No. of bitstreams: 0
Previous issue date: 2009-02-12Bitstream added on 2014-06-13T20:02:03Z : No. of bitstreams: 1
vieira_na_dr_botfm.pdf: 811081 bytes, checksum: 2278982cab7496707fe49b900b22418d (MD5)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
Universidade Estadual Paulista (UNESP)
O ecossistema gastrintestinal é caracterizado por interações recíprocas e dinâmicas entre o epitélio gastrintestinal, células do sistema imunológico e sua microbiota intestinal (MI), a qual desempenha atividades metabólicas importantes locais (mucosa intestinal) e sistêmicas. Avaliar a MI de crianças com malformação craniofacial atendidas em um hospital especializado e verificar a influência da antibioticoprofilaxia com cefazolina em palatoplastia foi o objetivo desse trabalho. Foram isoladas e quantificadas as bactérias anaeróbias intestinais dos gêneros Bacteroides sp, Bifidobacterium sp e Lactobacillus sp nas fezes de 11 crianças sem fissura de palato (C) e de 50, com fissura de palato (FP), no período compreendido entre maio de 2007 a setembro de 2008. Foi avaliada a MI de 18 crianças com fissura de palato após 24 horas de tratamento, em dose única na indução anestésica, com cefazolina para palatoplastia. Observou-se que a frequência de Bacteroides sp foi maior no grupo FP (p < 0,001). Para Lactobacillus sp, houve tendência a maior quantidade (p = 0,086) no grupo FP. Não houve diferença na frequência de Bifidobacterium sp entre os dois grupos de crianças (p = 0,495). Houve diminuição do número de UFCs de Bacteróides sp (p = 0,031) e Lactobacillus sp (p = 0,004) em crianças com fissura tratadas com cefazolina em cirurgia de palato. Para o gênero Bifidobacterium sp, houve tendência à diminuição nas UFCs (p = 0,063). A dificuldade de ingestão de nutrientes, aleitamento materno insuficiente, otites recorrentes, entre outras ocorrem com frequência em indivíduos com malformação craniofacial, o que pode ter influenciado na composição da MI. A associação da palatoplastia e o uso de antibiótico...
The gastrointestinal ecossystem is characterized by reciprocal and dynamic interactions between the host and the intestinal microbiota (IM), which performs local important metabolic (intestinal mucosa) and systemic activities. The purposes of this study are the assessment of the IM in children with craniofacial malformation attended at a specialized hospital and the verification of the influence of the antibiotic prophylaxis with cefazolin on palatoplasty. The intestinal anaerobic bacteria Bacteroides sp, Bifidobacterium sp and Lactobacillus sp were isolated and quantified in the feces of 11 non-cleft children (NC) and 50 cleft children (CP), from May 2007 to September 2008. After a 24-hour treatment, the IM in 18 cleft children was evaluated – in a single dose – by means of anesthetic induction with cefazolin, in palatoplasty. It was observed that the Bacteroides sp occurred more often in the CP group (p < 0.001). Regarding the Lactobacillus sp, the largest quantity (p = 0.086) tended towards the CP group. There was no frequency difference for the Bifidobacterium sp between the two groups of children (p = 0.495). There was a reduction in the number of Colony-Forming Units (CFUs) for the Bacteroides sp (p = 0.031) and the Lactobacillus sp (p = 0.004) in cleft children treated with cefazolin, in palate surgeries. Regarding the Bifidobacterium sp, there was a reduction tendency in the CFUs (p = 0.063). The difficulty to ingest nutrients, the insufficient breastfeeding, the recurrent otitis – among other things – are frequent in individuals with craniofacial malformation, which may have influenced the IM composition. The association between palatoplasty and the use of antibiotics has intensified the IM changes. New investigations must be performed in order to verify which factors related to the craniofacial malformation, the surgical treatment and the use of antimicrobians would... (Complete abstract click electronic access below)
48
Sanches, Raisa Déli de Oliveira. "Purificação e caracterização bioquímica da CGTase produzida por Paenibacillus campinasensis H69-3 /". São José do Rio Preto, 2018. http://hdl.handle.net/11449/180437.
Texto completo da fonteResumo:
Orientador: Heloiza Ferreira Alves do PradoBanca: Gustavo Orlando Bonilla Rodriguez
Banca: Renato Grillo
Banca: Andréia Aparecida Jacomassi Carneiro
Banca: Hamilton Cabral
Resumo: Uma ciclomaltodextrina glucanotransferase (E.C. 2.4.1.19, CGTase) produzida pelo microrganismo Paenibacillus campinasensis linhagem H69-3, foi obtida por fermentação submersa a 45 °C, e a CGTase purificada por cromatografia de afinidade bioespecífica em resina Sepharose 6B ativada com β-CD. A enzima foi purificada até 23 vezes, obtendo um rendimento de 11,0%, e a atividade específica de 32,6 U mg-1 ao final da etapa de purificação. A massa molecular da enzima purificada foi estimada em 72 kDa por eletroforese desnaturante em gel de poliacrilamida na presença de dodecil-sulfato de sódio. O pH ótimo para a atividade enzimática foi de 6,5 e a enzima foi estável na faixa de pH de 6,5 a 8,0. A temperatura ótima foi de 65 °C em pH 6,5, e foi térmicamente estável até 55 °C na ausência de substrato durante 1 h de incubação e estável até 65 °C na presença de Ca2+ 5 mmol L-1. A atividade enzimática aumentou na presença de Ba2+, Mg2+, Ca2+, Ni2+, K+, Zn2+ e foi inibida na presenca dos íons metálicos Cu2+, Hg2+, Ag+, Li2+, Al3+ e NH42+ e por β‑, γ‑CD, DMSO, Triton, SDS e NaN3. Utilizando maltodextrina como substrato a CGTase apresentou 11,0±0,5 µmol min·mg e 0,30 ± 0,07 mg mL‑1, Vmáx e Km, respectivamente. Avaliaram-se os parâmetros termodinâmicos da CGTase, que demonstrou mais de 11 horas a 65 ºC como tempo de meia vida, e elevada resistência estrutural à desnaturação térmica quando avaliados os resultados de entropia, energia de ativação e entalpia
Abstract: A cyclomaltodextrin glucanotransferase (E.C. 2.4.1.19, CGTase) produced by 4 microorganism Paenibacillus campinasensis strain H69-3 was obtained by submerged fermentation at 45 °C and CGTase purified by biospecific affinity chromatography on β-CD activated Sepharose 6B resin. The enzyme was purified up to 23 times, yielding 11.0% yield, and the specific activity of 32.6 U mg-1 at the end of the purification step. The molecular weight of the purified enzyme was estimated at 72 kDa by denaturing polyacrylamide gel electrophoresis in the presence of sodium dodecyl sulfate. The optimum pH for the enzymatic activity was 6.5 and the enzyme was stable in the pH range of 6.5 to 8.0. The optimum temperature was 65 °C at pH 6.5 and was thermally stable at 55 °C in the absence of substrate for 1 h incubation and stable at 65 ° C in the presence of Ca2+ 5 mmol L -1. The enzyme activity increased in the presence of Ba2+, Mg2+, Ca2+, Ni2+, K+, Zn2+ and was inhibited in the presence of Cu2+, Hg2+, Ag+, Li2+, Al3+ and NH42+ ions and by β, γ -CD, DMSO, Triton, SDS and NaN3. Using maltodextrin as substrate CGTase presented 11.0 ± 0.5 μmol min · mg and 0.30 ± 0.07 mg mL-1, Vmax and Km, respectively. The thermodynamic parameters of CGTase, which demonstrated more than 11 hours at 65 ºC as a half-life, and high structural resistance to thermal denaturation were evaluated when the results of entropy, activation energy and enthalpy were evaluated
Doutor
49
Massarente, Vanessa Salto. "Caracterização bioquímica e purificação das endoglucanases produzidas por Myceliophthora thermophila M.7.7 em cultivo em estado sólido /". São José do Rio Preto, 2018. http://hdl.handle.net/11449/154468.
Texto completo da fonteResumo:
Orientador: Gustavo Orlando Bonilla RodriguezCoorientador: Eleni Gomes
Banca: Vanildo Luiz Del Bianchi
Banca: Luciano Takeshi Kishi
Resumo: As celulases são enzimas empregadas principalmente na indústria de papel e celulose e têxtil, e têm ganhado destaque pelo seu potencial hidrolítico em materiais lignocelulósicos na produção de etanol, já que são capazes de hidrolisar a celulose. O objetivo do projeto foi efetuar a caracterização e isolamento das endoglucanases produzidas pelo fungo termofílico Myceliophthora thermophila M.7.7 em cultivo em estado sólido. Foram realizados ensaios para avaliar os efeitos do pH, da temperatura, de diversas substâncias químicas, cátions e compostos fenólicos na atividade enzimática. A estimativa da massa molecular foi realizada por eletroforese em gel de poliacrilamida (SDS-PAGE), e como resultado foi possível observar sete endoglucanases detectadas por zimografia, que possuem massa molecular estimada entre 26 e 82 kDa. O valor ótimo para o pH do extrato enzimático bruto foi 5,5 e 70ºC para a temperatura ótima em incubação de 4 minutos. Em relação à estabilidade do extrato bruto, os maiores valores ocorreram entre as faixas de pH de 6 a 6,5, e 30 e 40ºC para temperatura até 120 minutos. Entre os reagentes testados, Triton, DTT e Isopropanol aumentaram a atividade enzimática sobre o extrato bruto em cerca de 10%. Os cátions NaCl, SrCl2, BaCl2 e ZnCl2 aumentaram a atividade das endoglucanases. Em relação aos compostos fenólicos, todos induziram em diversos graus o decréscimo da atividade das endoglucanases do extrato bruto. Das sete endoglucanases, três foram isoladas pela extração...
Abstract: Cellulases are enzymes used mainly in the paper and cellulose and textile industries and have been highlighted for their hydrolytic potential in lignocellulosic materials in the production of ethanol, since they are capable of hydrolyzing cellulose. The objective of the project was to characterize and isolate the endoglucanases produced by the thermophilic fungus Myceliophthora thermophila M.7.7 in solid state cultivation. Tests were carried out to evaluate the effects of pH, temperature, several chemical substances, cations and phenolic compounds on enzymatic activity. The molecular weight estimation was performed by polyacrylamide gel electrophoresis (SDS-PAGE), and as a result it was possible to observe seven endoglucanases detected by zymography, which have an estimated molecular mass between 26 and 82 kDa. The optimum pH for the crude enzyme extract was 5.5, and 70 °C for the optimum incubation temperature for 4 minutes. Regarding the stability of the crude extract, the highest values occurred between the pH ranges from 6 to 6.5, and 30 to 40ºC for temperature up to 120 minutes. Among the tested reagents, Triton, DTT and Isopropanol increased the enzymatic activity on the crude extract by about 10%. NaCl, SrCl2, BaCl2 and ZnCl2 increased the endoglucanase activity. With respect to the phenolic compounds, all induced to varying degrees the decrease in the activity of the endoglucanases of the crude extract. Of the seven endoglucanases, three were isolated by direct gel ...
Mestre
50
Rodrigues, Daniele Masselli 1972. "Infecção por Cardiovirus (virus da encefalomielite murina de Theiler - TMEV) em colonias convencionais de ratos". [s.n.], 2004. http://repositorio.unicamp.br/jspui/handle/REPOSIP/317119.
Texto completo da fonteResumo:
Orientador: Maria Silvia Viccari GattiDissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Biologia
Made available in DSpace on 2018-08-03T22:33:53Z (GMT). No. of bitstreams: 1 Rodrigues_DanieleMasselli_M.pdf: 1852380 bytes, checksum: f83cb847eec2bcf31bf414b3bbf154ba (MD5) Previous issue date: 2004
Resumo: O vírus da encefalomielite murina de Theiler (TMEV) é um patógeno entérico de camundongos, pertencente ao gênero Cardiovirus da família Picornaviridae. O TMEV é um vírus não envelopado, icosaédrico, com 20 - 30 nm e genoma constituído de RNA fita simples com polaridade positiva. Os TMEV têm sido classificados em dois subgrupos, de acordo com sua atividade biológica após inoculação intracerebral. Cepas neurovirulentas (GDVII e FA) induzem uma encefalite aguda e fatal, enquanto aquelas de baixa virulência (TO, WW, DA e BeAn) persistem no sistema nervoso central, induzindo doença crônica, caracterizada por desmielinização. A infecção natural por TMEV tem sido demonstrada em colônias onvencionais de camundongos e, em sua maioria, a infecção é assintomática. Embora o TMEV seja descrito como um patógeno de camundongos, anticorpos para TMEV-GDVII têm sido detectados em soros de ratos provenientes de biotérios que mantêm colônias convencionais. A prevalência da infecção por TMEV-GDVII nestas colônias de ratos é alta, em torno de 54,6%. Assim, este trabalho teve por finalidade demonstrar, por métodos sorológicos e molecular, a infecção natural por TMEV em colônias de ratos. Soros destes animais foram analisados pela reação de imunofluorescência indireta e a presença de anticorpos anti-TMEV-GDVII foi detectada em 86,3% deles. Ao mesmo tempo, pelo teste de soroneutralização, 77,2% destes soros demonstraram anticorpos neutralizantes para TMEV-GDVII. Com o objetivo de isolar o vírus de ratos, sistemas ¿in vitro¿ e ¿in vivo¿ foram utilizados. Nove passagens sucessivas de amostras de suspensão intestinal foram feitas em células BHK-21 e não foi possível demonstrar efeito citopático. Sinais clínicos da infecção por TMEV em camundongos, ou seja, paralisia das patas posteriores e tremores, foram demonstrados em camundongos e ratos neonatos inoculados com suspensão intestinal de ratos soropositivos e com a cepa padrão de TMEV-GDVII. Os resultados da RT-PCR demonstraram a presença de RNA viral em amostras de cérebro de ratos inoculados com a suspensão intestinal, com TMEV-GDVII e nas amostras de fezes de ratos provenientes de diferentes biotérios convencionais. Os resultados demonstram que ratos se infectam naturalmente por TMEV e, embora hajam poucas descrições na literatura da interferência deste vírus em pesquisas biomédicas, a monitoração sanitária para TMEV em biotérios que mantêm colônias de ratos deve ser incluída
Abstract: Theiler¿s murine encephalomyelitis virus (TMEV) is an enteric pathogen of mice and belongs to the Cardiovirus genus in the family Picornaviridae. TMEV is a non-enveloped, icosaedric virus with 20 ¿ 30 nm size and it has an RNAss positive sense genome. TMEV has been divided in two subgroups on the basis of their biological activities after intracerebral inoculation. Neurovirulent strains (GDVII and FA) causes an acute and fatal encephalitis in mice and in contrast, low neurovirulent strains (DA, BeAn 8386, WW and TO) causes a persistent infection in the central nervous system and produce a chronic disease characterized by demyelination. TMEV infection with low neurovirulent strains has been used as an experimental model to help the studies on demyelination process induced by virus infection and to study diseases as Multiple Sclerosis. The natural infection by TMEV has been related in conventional colonies of mice and it¿s frequently asymptomatic. Although TMEV has been described as a pathogen of mice, antibodies against TMEV-GDVII has been detected in serum of rats reared in non-barrier colonies. Facing this, the purpose of the present study was to demonstrate the natural infection of TMEV in rat colonies through serological and molecular methods (RT-PCR). The rat serum were analysed by indirect immunofluorescence assay and antibodies against TMEV-GDVII were detected in 86,3% of the serum analysed. In the neutralization assay, 77,2% of the same serum showed neutralizing antibodies anti TMEVGDVII. To further isolate this rat virus, ¿in vitro¿ and ¿in vivo¿ systems were used. Nine blinded passages of the intestinal suspension were realized in BHK-21 cells, but no citopathic effect was identified. Clinical signs of TMEV infection in mice were characterized by flaccid paralisis of hind legs and tremor when newborn rats and mice were inoculated with intestinal suspension of seropositive rats and with the prototype strain of TMEV-GDVII. The RT-PCR results showed the RNA genome in the brain samples of rats and mice inoculated both with the intestinal suspension and the prototype strain. In the fecal samples, the RNA genome was also detected. In summary, rats can be naturally infected by TMEV and although there are a few examples in the literature of TMEV infection interference with biomedical researches, a health monitoring program for TMEV should be included in the rat colonies
Mestrado
Microbiologia
Genetica e Biologia Molecular