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1
Chow, Ka-hang. "Molecular characterization of RTX toxin of vibrio cholerae causing epidemics". Click to view the E-thesis via HKUTO, 2001. http://sunzi.lib.hku.hk/hkuto/record/B42575898.
Testo completo
2
Kural, Ayse G. "Temperature-assisted pressure inactivation of Vibrio parahaemolyticus and Vibrio vulnificus in oysters". Access to citation, abstract and download form provided by ProQuest Information and Learning Company; downloadable PDF file, 89 p, 2007. http://proquest.umi.com/pqdweb?did=1338870531&sid=16&Fmt=2&clientId=8331&RQT=309&VName=PQD.
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3
Rubio, Galleguillos Felipe Andrés. "Implementación de técnica para la detección de vibrios y análisis de Vibrio vulnificus en muestras de alimentos". Tesis, Universidad de Chile, 2006. http://repositorio.uchile.cl/handle/2250/105607.
Testo completoAbstract (sommario):
Unidad de práctica para optar al título de Químico FarmacéuticoNo autorizada por el autor para ser publicada a texto completo en el Portal de Tesis Electrónicas
La practica prolongada fue realizada en Departamento de Microbiología de Alimentos del Instituto se Salud Pública de Chile, durante los meses de Junio a Diciembre del año 2005. Mi labor en la práctica constó de tres etapas simultáneas: La primera consistió en recibir capacitación durante todo el período de mi práctica, en detección y cuantificación de los patógenos bacterianos más frecuentes encontrados en alimentos. La segunda etapa fue implementar el último método de detección de Vibrios (principalmente Vibrio vulnificus en mi caso) según el Manual Analítico Bacteriológico (BAM) año 2004 impuesto por la Food and Drugs Administration (FDA) (1), para la cual se utilizaron cepas de diversos Vibrios tales como Vibrio vulnificus, Vibrio parahaemolyticus, Vibrio cholerae, etc. Dicha labor será necesaria para actualizar los métodos de detección en los laboratorios de la red de vigilancia epidemiológica de Chile. En la otra etapa, se evaluó según el método que se estaba desarrollando la población de Vibrio vulnificus existente en Puerto Montt, ésta etapa se comenzó a trabajar a partir aproximadamente en julio ya que primero debía estar desarrollada en alguna medida la técnica de detección, además de que estuvieran los materiales necesarios para el trabajo. Las muestras analizadas son ensayos de rutina que llegan al SEREMI de Salud de la región Metropolitana para evaluar durante todo el año la población de Vibrio parahaemolyticus y Vibrio cholerae en Puerto Montt, las cuales se reciben todos los martes y consta de 5 muestras de los cuales se analizan 12 especimenes de cada una, para luego cuantificarlas por el método de tubos múltiples según la tabla de número más probable (anexo, Tabla 1). Es importante que el ISP, como centro de referencia posea información sobre todo patógeno que pueda ser encontrado en alimentos, es por eso que esta etapa culminará con la entrega del procedimiento de detección de Vibrio vulnificus al Departamento de Microbiología de Alimentos
4
Leung, Y. Tai Ida. "Infections à vibrio vulnificus, revue de la littérature à propos d'une observation de septicémie". Bordeaux 2, 1996. http://www.theses.fr/1996BOR2M053.
Testo completo
5
Hardman, Andrea M. "Quorum sensing in vibrio anguillarum". Thesis, University of Nottingham, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.363936.
Testo completo
6
Chalker, Victoria J. "Quorum sensing in Vibrio anguillarum". Thesis, University of Nottingham, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.325714.
Testo completo
7
Limthammahisorn, Suttinee Brady Yolanda Juanita Arias Covadonga R. "In vitro and in vivo cold shock response in Vibrio vulnificus". Auburn, Ala., 2007. http://repo.lib.auburn.edu/Send%2002-04-08/LIMTHAMMAHISORN_SUTTINEE_24.pdf.
Testo completo
8
Alvarez, Julia D. "Studies on Venezuelan fish and shrimp associated bacteria". Thesis, Heriot-Watt University, 1998. http://hdl.handle.net/10399/619.
Testo completo
9
Lima, Anahy de Souza. "VÃbrio em camarÃo e na Ãgua de trÃs fazendas de carcinicultura do CearÃ". Universidade Federal do CearÃ, 2007. http://www.teses.ufc.br/tde_busca/arquivo.php?codArquivo=2876.
Testo completoAbstract (sommario):
O presente estudo teve por objetivo quantificar Vibrio, vibrios sac+ e sac â e identificar as espÃcies de Vibrio, presentes no cultivo do camarÃo Litopenaeus vannamei e na Ãgua onde à ele cultivado. Acompanharamse dois ciclos do cultivo do L. vannamei em trÃs fazendas (A, B e C),situadas nos estuÃrios dos rios AcaraÃ, Coreaà e Jaguaribe (CE), de agosto de 2005 a outubro de 2006, nas estaÃÃes de chuva e estiagem. Foram analisadas 60 amostras de camarÃo e 240 amostras de Ãgua de viveiro. Foram feitos os testes de Contagem PadrÃo em Placas (CPP) total de Vibrio; CPP das colÃnias de Vibrio sacarose positivas e negativas, e identificaÃÃo das espÃcies nas amostras de camarÃo e na Ãgua. O valor mÃnimo da CPP de Vibrio nas amostras de Ãgua foi de 2,0 x 102 UFC/mL nas fazendas A, e C no perÃodo de chuva e o mÃximo foi 1,42 x 108 UFC/mL na fazenda B, no perÃodo de estio. O valor mÃximo para CPP de Vibrio nas amostras de camarÃo (pÃs-larva e hepatopÃncreas) foi de 4,5 x 108 UFC/g, na fazenda B no perÃodo de estio. O valor mÃnimo de Vibrio sacarose positiva no hepatopÃncreas foi 1,00 x 102 UFC/g nas fazendas A e B no perÃodo de chuva e mÃximo foi 4,5 x 108 UFC/g na fazenda B, no perÃodo de estio. O valor mÃnimo de Vibrio sacarose negativa foi 0,98 x 10 UFC/g de hepatopÃncreas na fazenda A, no perÃodo de chuva e mÃximo foi de 9,50 x 105 na fazenda C no perÃodo da chuva. A CPP de vibrios das amostras de Ãgua e do camarÃo foi sempre menor no perÃodo da chuva. Das amostras de Ãgua e camarÃo das trÃs fazendas foram isoladas 145 cepas de Vibrio. Dessas, 62 foram isoladas da Ãgua de cultivo do camarÃo e 56 foram isoladas do camarÃo (pÃs-larva e hepatopÃncreas). A fazenda B apresentou maior nÃmero de diferentes espÃcies isoladas e identificadas (11). Durante a esquisa, os isolados de camarÃo e Ãgua do viveiro, Apresentaram uma predominÃncia de Vibrio mimicus, seguidos de V.alginolyticus e V. tubiashii. De todas as fazendas, A, B e C, a fazenda Afoi a que apresentou um viveiro com a menor taxa de sobrevivÃncia de camarÃes na despesca: 37,24%, no perÃodo da chuva.Nem a quantidade de vÃbrios total, nem a de sacarose positiva, ou negativa no hepatopÃncreas dos camarÃes, influencia o Ãndice de SobrevivÃncia dos animais nos viveiros das fazendas, no momento da despesca. A maior ou menor diversidade de vÃbrios nos camarÃes nÃo implicou numa maior ou menor taxa de sobrevivÃncia dos animais nos viveiros das fazendas, no momento da despesca. No entanto, quando o nÃmero de Vibrio foi alto na Ãgua e a diversidade baixa, caso da Fazenda A no perÃodo da chuva, a taxa de sobrevivÃncia foi afetada negativamente. O nÃmero de vÃbrios à proporcional ao teor de salinidade das Ãguas. Somente os dados da enumeraÃÃo de vÃbrios e/ou os dados da enumeraÃÃo de vÃbrio sacarose positiva ou negativa nÃo sÃo suficientes para se avaliar a probabilidade de camarÃes, de um determinado viveiro, virem a adoecer.This study aimed to quantify Vibrio, Vibrio and sac + sac - and identify the species of Vibrio, in the cultivation of shrimp Litopenaeus vannamei and water where it is grown. Acompanharamse two cycles of cultivation of L. vannamei in three farms (A, B and C), located in river estuaries AcaraÃ, and Coreaà Jaguaribe (EC), August 2005 to October 2006, at the stations of rain and drought. We analyzed 60 samples of shrimp and 240 samples of water from nursery. The tests were made in Standard Plate Count (CPP) of total Vibrio; CPP of colonies of Vibrio sucrose positive and negative, and identification of species in samples of shrimp and water. The minimum value of the CPP of Vibrio in the water samples was 2.0 x 102 CFU / mL in farms A and C in the period of rain and the maximum was 1.42 x 108 CFU / mL in farm B, in the period of summer . The maximum value for CPP of Vibrio in samples of shrimp (post-larva and hepatopÃncreas) was 4.5 x 108 CFU / g in farm B during the summer. The minimum value of sucrose positive Vibrio in hepatopÃncreas was 1.00 x 102 CFU / g in farms A and B in the period of rainfall and maximum was 4.5 x 108 CFU / g in farm B, in the period of summer. The minimum value of sucrose negative Vibrio was 0.98 x 10 CFU / g of hepatopÃncreas in farm A, the maximum period of rain and was 9.50 x 105 C on the farm during the rain. The CPP of Vibrio from water samples and the shrimp was always lower during the rain. Of water samples and the three shrimp farms were isolated 145 strains of Vibrio. Of these, 62 were isolated from the water culture of shrimp and 56 were isolated from shrimp (post-larva and hepatopÃncreas). The farm B showed the largest number of species isolated and identified (11). During esquisa, isolated from the shrimp and water in the nursery, showed a predominance of Vibrio mimicus, followed by V.alginolyticus and V. tubiashii. Of all the farms, A, B and C, Afoi farm that had a nursery with the lowest survival rate of shrimps in despesca: 37.24%, during the chuva.Nem the amount of Vibrio total nor the sucrose positive or negative in hepatopÃncreas of shrimp, influences the rate of survival of animals in the nursery of the farms at the despesca. The greater or lesser diversity of Vibrio in shrimp did not involve a greater or lesser rate of survival of animals in the nursery of the farms at the despesca. However, when the number of Vibrio in the water was high and low diversity, the case of Finance during the rain, the survival rate was affected negatively. The number of Vibrio is proportional to the level of salinity of water. Only data from the enumeration of Vibrio and / or data from the enumeration of Vibrio sucrose positive or negative is not sufficient to assess the likelihood of shrimp in a nursery, will sicken.
10
Mayer, Cintia Carolina da Silva. "Detecção molecular e resistência a antimicrobianos no grupo V. fluvialis - V. furnissii". Universidade de São Paulo, 2010. http://www.teses.usp.br/teses/disponiveis/6/6135/tde-28102010-144542/.
Testo completoAbstract (sommario):
Introdução - Vibrio fluvialis é um microorganismo que provoca a gastroenterite muito semelhante à cólera, mas também há relatos de casos extra-intestinais como sepse, ferida, peritonite e celulite hemorrágica e encefalite. Acredita-se que a infecção por esse microorganismo esteja vinculada ao consumo de peixes crus ou mal cozidos contaminados e / ou frutos do mar. A identificação dessa bactéria por métodos fenotípicos continua a ser um problema devido à sua grande semelhança com Aeromonas hydrophila e V.furnissii; por isso, a utilização de uma ferramenta de diferenciação entre essas espécies é importante. Nas últimas décadas, o aumento da resistência aos antimicrobianos tem sido um fator preocupante, porque ela interfere na escolha dos medicamentos para o tratamento eficaz e há uma necessidade de rápida produção de novos antibióticos. Ambientes costeiros e estuários estão em perigo de serem contaminados por esgoto, que pode conter drogas que agem de forma seletiva, permitindo o desenvolvimento de resistência aos antimicrobianos. Vários estudos demonstraram que estirpes clínicas de V. fluvialis são resistentes a múltiplas drogas. Objetivos - Desenvolver um marcador molecular baseado no 16S rDNA capaz de detectar o grupo V. fluvialis-V. furnissii, e avaliar a susceptibilidade a antibióticos destas espécies, principalmente a partir de amostras ambientais. Métodos - Após a elaboração dos iniciadores a partir do alinhamento das espécies do gênero Vibrio, foram utilizadas cepas identificadas fenotipicamente como V. fluvialis e de V. furnissii para a sua detecção molecular. O perfil de susceptibilidade a antibióticos pelo método da disco-difusão foi realizada, assim como a investigação molecular da presença do elemento SXT e de seus genes de resistência a antimicrobianos. Resultados: Com a utilização dos iniciadores desenvolvidos foi possível confirmar corretamente as espécies. Observou-se alta porcentagem de resistência a ampicilina e cefalotina, sendo que 65,9por centode V. fluviais e 43,24por centode V. furnissi apresentaram resistência a pelo menos dois dos antibióticos utilizados. Somente em uma cepa de V. fluvialis detectou-se a presença de SXT e houve uma banda desconhecida de alto peso molecular quando da pesquisa do gene sulII. Conclusões: O método molecular mostrou ser um importante instrumento para se detectar espécies altamente relacionadas. Foram detectadas cepas resistentes a múltiplos antibióticos, indicando que o meio ambiente é um provável reservatório de genes de resistência; porém necessita-se de futuras investigações moleculares para se determinar o papel destes e sua possível associação com elementos genéticos. A detecção do elemento SXT sem a presença dos seus genes de resistência conhecidos atualmente reforça a idéia da extensão de seu papel adaptativo, além de ser o primeiro relato de sua existência na América do SulIntroduction - Vibrio fluvialis is a microorganism that causes gastroenteritis very similar to cholera, however there are also reports of extraintestinal cases as sepse, skin wounds, peritonitis and hemorrhagic cellulitis and cerebritis. It is believed that infection by this organism is linked to the consumption of raw or undercooked contaminated fish and / or seafood. Identification of this bacteria by phenotypic methods remains a problem due to its great similarity with Aeromonas hydrophila and V.furnissii, therefore the use of a tool to differentiate these species is important. In recent decades, increasing antimicrobial resistance has been a concerning factor because it interferes in the choice of drugs for effective treatment and there is a need for rapid production of new antibiotics. Coastal and estuarine environments are in danger of being contaminated by sewage, which may contain drugs that will act selectively, allowing the development of antimicrobial resistance. Several studies have demonstrated that clinical strains of V. fluvialis are resistant to multiple drugs. Objectives - To develop a 16S rDNA - molecular marker able to detect the group V. fluvialis-V.furnissii, and to evaluate the antibiotic susceptibility of this species mainly from environmental samples. Methods - After the development of primers from alignment of the genus Vibrio strains phenotypically identified as V. fluvialis and V. furnissii were used for their molecular identification. The profile of antibiotic susceptibility was performed by the disk diffusion method, and the molecular investigation of the presence of the SXT element and their antimicrobial resistance genes. Results - The primers developed were able to confirm correctly the species. A high percentage of resistance to ampicillin and cephalothin was observed, V. fluvialis and V. furnissii showed resistance to at least two of the antibiotics used, 65.9 per cent and 43.24 per cent respectively. Only in one strain of V. fluvialis we detected presence of SXT and there was an unknown band of high molecular weight when we investigated gene sulII. Conclusions - Molecular identification has proved to be an important tool for differentiating highly related species. Strains resistant to multiple antibiotics were detected, indicating that the environment is likely a reservoir for resistance genes, but it is needed further molecular investigations to determine their role and their possible association with genetic elements. Detection of the SXT element without the presence of its known resistance genes reinforces the idea of the extent of its adaptive role, and this is the first report of its existence in South America
11
Guidolin, Angelo. "Molecular biology of "Vibrio cholerae" bacteriophage CP-T1 and its host interactions". Title page, contents and abstract only, 1985. http://web4.library.adelaide.edu.au/theses/09PH/09phg948.pdf.
Testo completo
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Midonet, Caroline. "Mécanisme d'intégration du phage TLC dans le génome de Vibrio cholerae". Thesis, Université Paris-Saclay (ComUE), 2016. http://www.theses.fr/2016SACLS314/document.
Testo completoAbstract (sommario):
La plupart des bactéries ont un unique chromosome circulaire. Lors de la réplication de l’ADN, la circularité lie topologiquement les deux chromatides sœurs résultant de la réplication (caténanes et dimères). Ces liens topologiques doivent être résolus afin de permettre une bonne ségrégation de l’information génétique entre les deux cellules filles au cours de la division cellulaire. Les bactéries possèdent une machinerie très conservée: les recombinases à tyrosines XerC et XerD, capables de résoudre les dimères et une partie des caténanes, en catalysant un crossover au site spécifique dif situé dans la région Ter du chromosome. Lors de ce processus elles réalisent successivement deux échanges de brins. La réaction Xer est spatio-temporellement contrôlée par une protéine du divisome: FtsK. FtsK est une translocase qui pompe l’ADN à travers le septum de division. Lorsqu’elle rencontre une synapse constituée de deux sites dif chargés de XerC et XerD, elle active la catalyse de XerD pour initier le premier échange de brins. Dans un second temps XerC catalyse un second échange de brins indépendamment de FtsK. A ce jour le mécanisme d’activation de XerD n’est pas bien compris. Certains éléments mobiles résolvent leur états multimériques (tels que les plasmides) ou intègrent leur génome dans celui de leur hôte en détournant les recombinases XerCD. On parle d’IMEXs (integrative Mobile Element using Xer). Les éléments mobiles étudiés avant ma thèse utilisaient tous des voies de recombinaison initiées par la catalyse de XerC et ne nécessitant pas l’activation de XerD. Au cours de ma thèse j’ai étudié dans un premier temps le mécanisme d’intégration / excision d’une nouvelle classe d’IMEXs en utilisant comme modèle le phage TLCphi de Vibrio cholerae, la bactérie responsable du choléra. Par des approches de génétique j’ai démontré que TLCphi utilise une voie de recombinaison initiée par la catalyse de XerD et indépendante de FtsK. Mes travaux ont également montré que l’excision du phage participe à l’évolution des souches pandémiques de V.cholerae. Dans une seconde partie, j’ai identifié un facteur phagique qui permet à TLCphi de contourner le contrôle de FtsK sur l’activation de XerD. Ce facteur était une protéine de fonction inconnue présentant un domaine HTH et un domaine DUF3653. Ce dernier est retrouvé dans de nombreux IMEXs. Par des approches de biologie moléculaire j’ai étudié le mécanisme d’action de cette protéine. J’ai reproduit la réaction de recombinaison in vitro et démontré qu’elle active XerD en interagissant directement avec elle. Enfin dans un troisième temps, nous nous sommes intéressés aux disparités observées entre la recombinaison Xer chez E.coli et V.cholerae. En particulier, la recombinaison Xer semble agir seulement sur les dimères chez E.coli alors qu’elle est active également sur les monomères chez V.cholerae. Nous avons démontré que ces divergences de comportement ne viennent pas des Xer elles-mêmes, ni de leurs propriétés d'activations par FtsK. Elles résultent des différentes chorégraphies de ségrégation des chromosomes entre ces deux bactéries et dépendent également des vitesses de croissanceMost of bacteria have a single circular chromosome. During replication of DNA, this circularity can lead to two sister chromatids topologically linked (catenanes and dimers). These topological links have to be solved in order to allow good segregation of genetic information between the two daughter cells during cell division. Bacteria possess a highly conserved machinery: the tyrosine recombinases XerC XerD that are capable to resolve dimers and some catenanes, by catalyzing a crossover at the specific site dif located in the Ter region of the chromosome. During this process they realize two sequentialstrand exchanges.The Xer reaction is spatiotemporally controlled by a protein of the divisome: FtsK. FtsK is a pump that translocates DNA through the septum of division. When FtsK meets a synapse that consists of two dif loaded by XerC and XerD, it activates XerD catalysis that initiates first strand exchange. Secondly XerC catalyzes a second strand exchange independently of FtsK. To date the activation mechanism of XerD is not well understood. Some mobile elements solve their multimeric states (like plasmids) or integrate their genome into the chromosome of their host by using XerCD recombinases. Such integrative elements are named IMEXs (Integrative Mobile Element using Xer). The mobile elements studied before my thesis all used recombination pathways initiated by catalysis of XerC and not requiring activation of XerD .During my PhD I studied at first the integration mechanism / excision of a new class IMEXs using as a model the TLC phage Vibrio cholerae, the bacterium responsible for cholera. By genetic approaches I demonstrated that TLCphi uses a recombination pathway initiated by XerD catalysis and independently of FtsK. My work has also shown that the phage excision participates in the evolution of pandemic strains of V. cholerae. In the second part, I identified a phage factor that allows TLC to bypass the activation of XerD by FtsK. This factor was a protein of unknown function with a HTH domain and a DUF3653 domain. DUF3653 are found in many IMEXs. Using molecular biology approaches, I studied the mechanism of action of this protein. I reproduced the recombination reaction in vitro and demonstrated that this factor activates XerD by directly interacting with it. Finally, we were interested to study disparities between Xer recombination in E.coli and V.cholerae. In particular, the Xer recombination seems to act only on dimers in E.coli while it is also active on monomers in V.cholerae. We have demonstrated that these differences in behaviors do not come from Xer themselves or their activation by FtsK. They result from different choreographies of chromosome segregation between these two bacteria and are also dependent on growth rates
13
Cofie, Daniel Quarcoopome Guthrie Rufus K. "Effect of chitin on Vibrio cholerae /". See options below, 1988. http://proquest.umi.com/pqdweb?did=746612041&sid=1&Fmt=2&clientId=68716&RQT=309&VName=PQD.
Testo completo
14
Stroher, Vive Horst. "Serotype conversion in Vibrio cholerae 01 /". Title page, contents and abstract only, 1992. http://web4.library.adelaide.edu.au/theses/09PH/09phs919.pdf.
Testo completo
15
Reiger, Matthias. "Regulation der Autoinduktoren von Vibrio harveyi". Diss., Ludwig-Maximilians-Universität München, 2014. http://nbn-resolving.de/urn:nbn:de:bvb:19-177926.
Testo completoAbstract (sommario):
In Vibrio harveyi induzieren die drei Autoinduktoren (AIs) Z-3-Aminoundec-2-en-4-on CAI 1, N-(3-Hydroxybutyryl)-D-Homoserinlakton HAI 1 und der Furanosylboratdiester AI 2 die Quorum Sensing (QS) Regulationskaskade. So werden unter Anderem Biolumineszenz, Biofilmbildung und Exoproteaseaktivität beeinflusst. Um die Sensorik der QS Kaskade zu verstehen, wurde die Expression verschiedener QS-Zielgene im Wildtyp untersucht. Im Vergleich mit einer AI-negativen Mutante zeigte sich, dass nicht die Zelldichte sondern die Konzentration der verschiedenen AIs und deren Verhältnisse zueinander die QS-Signalkaskade steuern. Beides verändert sich in Abhängigkeit von der Medien-zusammensetzung und erlaubt so die Modulation z.B. der Biolumineszenz (Kapitel 2.1.). Die extrazelluläre AI-Konzentration im Medium hängt entscheidend von der Produktion sowie dem Transport ab. Während HAI-1 aufgrund seiner chemischen Eigenschaften frei aus der Zelle diffundiert, müssen CAI-1 und AI-2 aktiv über die Membran transportiert werden.
In Escherichia coli beeinflusst die Deletion des möglichen Transporters YdgG die extrazelluläre AI-2 Konzentration. Im Rahmen dieser Arbeit konnte bioinformatisch mit YhhQ ein zusätzlicher potentieller Exporter identifiziert werden. Bindestudien an beiden Proteinen, zeigten eine mikromolare Affinität für YhhQ jedoch nicht für YdgG. Im Gegensatz dazu ist die extrazelluläre AI-2-Konzentration der ΔydgG/ΔyhhQ Doppelmutante im Vergleich zu den Einzeldeletionen um 4 µM reduziert. In vivo Parallelstudien am YhhQ Ortholog in V. harveyi allerdings, lassen redundante Transportmechanismen vermuten. In diesem Zusammenhang könnte z.B. auch eine durch Phagen vermittelte Zelllyse eine Rolle spielen (Kapitel 2.2.1.).
Unabhängig von Produktion und Export kann die externe AI-Konzentration auch durch aktive Reduktion in Form von Import und intrazellulärem Abbau kontrolliert werden. In diesem Zusammenhang sagte die AG Bischofs einen AI-2-Importer vorher und dessen Vorhandensein wurde im Verlauf dieser Promotion experimentell validiert (Kapitel 2.2.2.).
Eine weitere Möglichkeit des sogenannten Quorum Quenching ist der Abbau von Acylhomoserinlaktonen wie HAI-1 durch Acylasen und Laktonasen. Bioinformatische Analysen aus der AG Streit identifizierten die fünf potentiellen Laktonasen VIBHAR_02708, VIBHAR_03213, VIBHAR_06370, VIBHAR_06736 und VIBHAR_06900. Jedoch, liegt nach intensiven Untersuchungen am Wildtyp und den „Laktonase“-Mutanten der Schluss nahe, dass es in V. harveyi keinen aktiven HAI-1 Abbau gibt. Vielmehr handelt es sich bei VIBHAR_06370 um eine β-Laktamase, die eine natürliche Ampicillinresistenz vermittelt (Kapitel 2.3.). Im Gegensatz dazu, kodieren VIBHAR_02708 und VIBHAR_03213 die Typ II Glyoxalasen GloB und GloC und tragen damit zur Detoxifikation von Methylglyoxal nicht nur in V. harveyi sondern auch in E. coli bei (Kapitel 2.4.).In Vibrio harveyi three autoinducers (AIs) Z-3-aminoundec-2-en-4-one CAI-1, N-(3-hydroxybutyryl)-D-homoserine lactone HAI-1 and the furanosylboratdiester AI-2 induce the quorum sensing (QS) regulatory cascade. Thus, among other phenotypes, bioluminescence, biofilm formation and exoprotease activity are affected. In order to understand the sensing mechanism of the QS cascade, the expression of various QS target genes in the wild type was examined. Compared to an AI-negative mutant it was obvious that not the cell density but the concentration of the different AIs and their interplay control the QS signaling cascade. Both changed depending on the media composition and thus allow the modulation of e.g. bioluminescence (Chapter 2.1.). The extracellular AI concentration in the medium depends crucially on the production and transport. Whereas HAI-1 diffuses freely out of the cell due to its chemical properties, CAI-1 and AI-2 have to be actively transported across the membrane. In Escherichia coli, the deletion of the putative transporter YdgG affects the extracellular AI-2 concentration. In this work an additional potential exporter YhhQ was identified bioinformatically. AI 2 binding studies on both proteins, showed a micromolar affinity for YhhQ but did not exhibit affinity for YdgG. In contrast to this, the extracellular concentration of the AI-2-ΔydgG/ΔyhhQ double mutant compared to the single deletion mutants is 4 µM lower. Parallel in vivo studies on the YhhQ ortholog in V. harveyi, however, suggest redundant transport mechanisms. In this context, cell lysis could also be involved. This is why the role of phage mediated lysis should be investigated (Chapter 2.2.1.). Regardless of production and export, the external AI concentration can also be controlled actively by import and subsequent degradation. In this context, the AG Bischofs predicted an AI-2 importer, which existence has been validated experimentally in the course of this PhD thesis (Chapter 2.2.2.). Another way of action of the so-called quorum quenching is the degradation of acylhomoserinlactones as HAI-1 by acylases and lactonases. Bioinformatics analysis of the AG Streit identified five potential lactonases VIBHAR_02708, VIBHAR_03213, VIBHAR_06370, VIBHAR_06736 and VIBHAR_06900. However, intensive studies on the wild type and the "lactonase" mutants showed that there is no active degradation of HAI-1 in V. harveyi. VIBHAR_06370 is a β-lactamase that conveys a natural ampicillin resistance (Chapter 2.3.). In contrast, VIBHAR_02708 and VIBHAR_03213 encode the type II glyoxalases GloB and GloC and thus contribute to the detoxification of methylglyoxal not only in V. harveyi but also in E. coli (Chapter 2.4.).
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Travers, Marie-Agnès. "Interaction de la bactérie Vibrio harveyi avec son hôte, l’ormeau Haliotis tuberculata : approches physiologiques, cellulaires et moléculaires". Brest, 2008. http://www.theses.fr/2008BRES2007.
Testo completoAbstract (sommario):
Depuis quelques années seulement, l’aquaculture d’ormeau se développe en Europe, mais doit déjà faire face à de nombreuses maladies. Les populations naturelles, comme les élevages d’Haliotis tuberculatcz, ont subi de fortes pertes depuis les années 1997, principalement à cause d’une bactérie pathogène, Vibrio harveyi. La vibriose de l’ormeau européen, ses signes macroscopiques, ainsi que les conditions favorables à son développement ont été étudiés par des suivis in situ et des expériences en laboratoire. Ces études nous ont permis de démontrer l’importance de la température (>17°C), de la physiologie des animaux (période de reproduction) et de la présence d’une souche pathogène (porteuse du plasmide pVCR1) pour le développement de la vibriose. Un cycle de la maladie et une première localisation des tissus cibles des ormeaux (branchies, muscle et hémolymphe) ont été proposés. De plus, un lien clair entre la période de reproduction avec un déficit immunitaire et la sensibilité des animaux a également été établi. Par des approches moléculaires, il a été démontré que les souches virulentes de V. Harveyi interfèrent avec le système immunitaire probablement via une inhibition partielle de la voie d’activation des MAP Kinases dans les hémocytes. Enfin, nous avons pu mettre en évidence le rôle clé des plasmides pVCR dans la virulence des souchesAbalone aquaculture has only recently been developed in western Europe, and already it has had to face numerous pathologies. Since 1998, natural and farm stocks of Haliotis tuberculata have suffered high mortalities on a regular basis, mainly due to the pathogenic bacterium, Vibrio harveyi. The vibriosis ofthe European abalone, in particular its macroscopic signs, and the conditions necessary for its development have been studied in detail by field and laboratory experiments. We have been able to show the importance of the interplay between water temperature (>17°C), animaI physiology (reproduction period) and a pathogenic strain (harbouring the plasmid pVCR1) for the development of this abalone disease. A limited localisation study of the abalone target tissues (gills, muscle and haemolymph) has been performed and a 3 phase disease development model is hypothesized. A clear link between the reproduction period with its accompanying immune difficiency and the animals sensitivy to the pathogen has been established. Using a molecular, approach strains of virulent V. Harveyi were found to directly intervene with the animal’s immune system, probably through a partial inhibition of the MAP kinase pathway activation in the haemocyte. Finally, we were also able to show the utmost importance ofthe pVCR plasmids for the virulence phenotype of this pathogenic bacterium
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Chow, Ka-hang, e 周嘉恆. "Molecular characterization of RTX toxin of vibrio cholerae causing epidemics". Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2001. http://hub.hku.hk/bib/B42575898.
Testo completo
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Carvalho, Edirsana Maria Ribeiro de. "Quantificação e identificação de Vibrio spp. na hemolinfa de camarões Litopenaeus vannamei cultivados em fazendas no Estado do Ceará". reponame:Repositório Institucional da UFC, 2009. http://www.repositorio.ufc.br/handle/riufc/18264.
Testo completoAbstract (sommario):
CARVALHO, Edirsana Maria Ribeiro de. Quantificação e identificação de Vibrio spp. na hemolinfa de camarões Litopenaeus vannamei cultivados em fazendas no Estado do Ceará. 2009. 89 f. : Dissertação (mestrado) - Universidade Federal do Ceará, Centro de Ciências Agrárias, Departamento de Engenharia de Pesca, Fortaleza-CE, 2009Submitted by Nádja Goes (nmoraissoares@gmail.com) on 2016-07-12T14:11:24Z No. of bitstreams: 1 2009_dis_emrcarvalho.pdf: 2284309 bytes, checksum: 922a46195a8b0319c114f69b1a9eefd9 (MD5)
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Most of shrimp bacterial infections are caused by Vibrio bacteria genus. This study aims to quantify identify Vibrio in the hemolymph of the marine shrimp Litopenaeus vannamei cultivated in farms in State of Cear, Brazil. Related is also the time of coagulation of hemolymph with counts of Vibrio. Sixteen samples were performed on four farms (A, B, C and D), eight shrimps with 4 g, and eight with eight grams shrimps. The collections were made in seasonal periods: rainy and drought. A total of 480 samples, and 240 to shrimps with 4 g and 8 g each, respectively. The values in the Standard Plate Count (SPC) of total vibrio, Vibrio Suc+ and Suc- in the hemolymph of shrimp samples with 4 g, in the rainy season ranged from: 2. 74 x 10⁴ to 28.70 x 10⁶ CFU/mL (est.), <6.0 to 14.64 x 106CFU/mL and <6.0 to 12.72 x 106 CFU/mL, respectively. For hemolymph of shrimp with 8 g of the SPC and the total Vibrio Suc+ and Sucranged from 1.68 x 10⁴ to 15.18 x 10⁶ CFU/mL (est.), <6.0 to 1.8 x 105 CFU/mL and <6.0 to 15.18 x 106CFU/mL (est). During the period of drought for these values of shrimp haemolymph of four grams, were: 9.0 x 10² (est.) to 5.40 x 104 CFU mL total Vibrio, <6.0 to 1.71 x 10⁴CFU/mL (Suc-) and <6.0 to 5.40 x 104 CFU/mL (Suc+). For shrimp with 8 g a total Vibrio count was 9.0 x 10² (est.) CFU/mL to 2.0 x 10⁷, <6.0 to 4.02 x 106 CFU/mL (Suc-) and <6.0 to 2.0 x 10⁷CFU/mL (est.) (Suc+). The results show that the rates of colonies of Vibrio Suc- and Suc+ were higher in the rainy season than in the drought. There was no relationship between the time of coagulation and the counts of Vibrio in the hemolymph of shrimps. The species that predominated in the period were: V. coralliilyticus, V. parahaemolyticus, Vibrio pelagius II, Vibrio alginolyticus, Vibrio mediterranei, Vibrio mimicus, Vibrio vulnificus B1
As infecções bacterianas em camarões são causadas, freqüentemente, por bactérias do gênero Vibrio O presente estudo teve por objetivo quantificar e identificar Vibrio na hemolinfa do camarão marinho Litopenaeus vannamei cultivado em fazendas no Estado do Ceará, Brasil. Relacionou-se também o tempo de coagulação das hemolinfas com as contagens de Vibrio. Foram realizadas 16 coletas em quatro fazendas (A, B, C e D), sendo oito para camarões com 4 g, e oito para camarões com oito gramas. As coletas foram realizadas nos períodos sazonais: chuvoso e estiagem. Perfazendo um total de 480 amostras, sendo 240 para camarões com 4 g e 8 g cada, respectivamente. Os valores da Contagem Padrão em Placas (CPP) de víbrios totais, de víbrios Sac+ e Sac-, nas amostras de hemolinfa dos camarões com 4g, no período chuvoso, variaram de: 2,74 x 104 a 28,70 x 106 UFC/mL (est.); de < 6,0 a 14,64 x 106UFC/mL e de < 6,0 a 12,72 x 106 UFC/mL, respectivamente. Para a hemolinfa dos camarões com 8 g os valores obtidos foram: 1,68 x 104 a 15,18 x 106 UFC/mL (est.), de < 6,0 a 1,8 x 105 UFC/mL e de < 6,0 a 15,18 x 106UFC/mL (est.), respectivamente. No período de estiagem esses valores para a hemolinfa dos camarões de quatro gramas, foram: 9,0 x 102 (est.) a 5,40 x 104 UFC/mL víbrio total; < 6,0 a 1,71 x 10⁴UFC/mL (Sac–) e de < 6,0 a 5,40 x 104 UFC/mL (Sac+). Para os camarões com 8 g a contagem de Víbrio total foi de 9,0 x 102 (est.) a 2,0 x 107, de < 6,0 a 4,02 x 106 UFC/mL (Sac-) e de < 6,0 a 2,0 x 10⁷ UFC/mL (est.) (Sac +). Os resultados mostram que os índices de colônias de Vibrio Sac- e Sac+ foram maiores no período chuvoso do que no de estiagem. Não houve relação entre o tempo de coagulação e as contagens de Vibrio na hemolinfa dos camarões. As espécies que predominaram nos períodos estudados foram: V. coralliilyticus, V. parahaemolyticus, Vibrio pelagius II, Vibrio alginolyticus, Vibrio mediterranei, Vibrio mimicus, Vibrio vulnificus B1.
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Lakhal, Fatma. "Développement d'outils génétiques pour identifier les facteurs de virulence chez Vibrio tapetis, un vibrio pathogène de palourde". Paris 11, 2007. http://www.theses.fr/2007PA112278.
Testo completoAbstract (sommario):
Les travaux de cette thèse ont porté sur le développement d’outils génétiques pour l’étude de Vibrio tapetis, l’agent étiologique de la maladie de l’anneau brun chez la palourde Ruditapes philippinarum. L’acquisition de ces outils a ainsi permis de caractériser djlA, un gène qui code pour une protéine chaperon membranaire de la famille de DnaJ/ Hsp40. L’analyse du locus de djlA chez V. Tapetis a révélé une organisation putative en opéron: en aval de djlA on trouve un gène Vt-duf924, codant pour une protéine de fonction inconnue. Il a été également montré l’importance de djlA dans la virulence chez V. Tapetis. Par ailleurs, un plasmide pVT1 de 82,3 kb a été isolé à partir de la souche V. Tapetis CECT 4600. PVT1 présente une structure en mosaïque et contient également un grand nombre d’éléments mobiles. Ainsi, l’analyse de pVT1 souligne l’importance des transferts horizontaux et le rôle de navette que jouent les plasmides dans l’acquisition de nouvelles ressources génétiques, parmi des bactéries partageant un même environnement. De plus, une caractérisation taxonomique basée sur une approche biochimique et de séquençage de l’ADN 16S a été menée sur une collection de souches Vibrio isolées de palourdes sains ou subissant des épisodes de mortalités en Tunisie. Il a été montré que la plupart des souches appartiennent au groupe des V. Splendidus. La virulence de trois de ces souches a été étudiée in vivo et in vitro. Ces souches ne semblent pas virulentes. L’ensemble des résultats obtenus ouvrent de nombreuses perspectives de recherche dans la compréhension des bases moléculaires de la virulence de V. Tapetis et vers une meilleure compréhension des interactions hôte-pathogèneThis thesis focused on the development of genetic tools for studying Vibrio tapetis, the causative agent of the brown ring disease affecting cultured Manila clams Ruditapes philippinarum. These tools were used to characterize djlA, a gene that encodes an inner membrane co-chaperone belonging to the DnaJ/Hsp40 family. Analysis of the djlA locus in V. Tapetis revealed a putative organization in operon with a downstream gene Vt-duf924, encoding a conserved protein. The importance of djlA for V. Tapetis virulence was demonstrated. In addition, pVT1, a 82. 3kb plasmid was isolated and its sequence determined. Interesting feature of pVT1 are its mosaic structure and the presence of numerous mobile genetic elements. The analysis of pVT1 underscores the importance of horizontal transfers amongst marine bacteria and plasmid shuffling in the acquisition of new genetic resources. Finally, a taxonomic characterization, based on biochemical characters and 16S rDNA sequencing was conducted on a collection of strains isolated from healthy or diseased clams in Tunisia. It was found that most strains belong to the species V. Splendidus. These strains did not appear to be virulent. The results open new perspectives to understand the molecular basis of the virulence of V. Tapetis and for a better understanding of bivalve-pathogen interactions
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Purins, Leanne Roslyn. "Molecular characterisation of the transcriptional activator, HLYU, of Vibrio cholerae O1 /". Title page, abstract and table of contents only, 2004. http://web4.library.adelaide.edu.au/theses/09PH/09php9857.pdf.
Testo completoAbstract (sommario):
Thesis (Ph.D.)--University of Adelaide, School of Molecular and Biomedical Science , Discipline of Microbiology and Immunology, 2005."May, 2004" Includes corrigenda. includes bibliographical references (leaves 118-156).
21
Pretto, Tobia <1985>. "Vibriosi da Vibrio harveyi: studi di eziopatogenesi e di efficacia vaccinale nel branzino (Dicentrarchus labrax)". Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2018. http://amsdottorato.unibo.it/8699/1/pretto_tobia_tesi.pdf.
Testo completoAbstract (sommario):
Vibrio harveyi rappresenta un patogeno batterico emergente per l’acquacoltura marina a livello globale.
Nel branzino V. harveyi è stato isolato in episodi di mortalità caratterizzati da atassia natatoria, lesioni cutanee ed enteriche.
Un protocollo polifasico di identificazione per V. harveyi è stato standardizzato basandosi su metodi biochimici, molecolari e proteomici ed è stato valutato raffrontando una collezione di 81 isolati di campo di V. harveyi (specie ittiche e bivalvi) con ceppi di referenza di V. harveyi e di altre 22 specie della famiglia Vibrionaceae. La valutazione fenotipica si è basata su prove in macrometodo, micrometodo (API20E) e crescita su terreni TCBS e CHROMagar Vibrio. L’analisi molecolare ha impiegato il sequenziamento del gene housekeeping pyrH, e l’amplificazione specie-specifica del gene toxR. Il profilo proteico è stato determinato mediante MALDI-TOF analizzando il contenuto proteico ribosomiale.
E’ stato valutato il profilo di sensibilità/resistenza agli antibiotici su 51 ceppi di V. harveyi, isolati da episodi clinici o da campioni ambientali, mediante metodo Kirby-Bauer e determinazione della minima concentrazione inibente (MIC).
È stata indagata mediante infezioni sperimentali (immersione e inoculo intraperitoneale IP) la patogenicità di differenti isolati di V. harveyi in branzino valutando le lesioni anatomo-istopatologiche indotte. È stato inoltre sviluppato un protocollo vaccinale basato su vaccino spento polivalente da somministrare per immersione o per inoculo IP, addizionato con estratto extracellulare ed emulsionato o meno con adjuvante. Sono state condotte prove di sicurezza ed efficacia vaccinale determinando per i vari protocolli la percentuale relativa di sopravvivenza (RPS). Un metodo ELISA indiretto è stato sviluppato per comparare la risposta immunitaria (IgM sieriche) degli esemplari vaccinati con i differenti protocolli, evidenziando una risposta significativamente maggiore nei soggetti inoculati IP con vaccino adjuvato.Vibrio harveyi is an emerging bacterial pathogen for marine aquaculture globally. In the European sea bass V. harveyi has been isolated in episodes of mortality characterized by ataxia, cutaneous and enteric lesions. In the present study, a polyphasic identification protocol for V. harveyi was standardized based on biochemical, molecular and proteomic methods and was evaluated by comparing a collection of 81 V. harveyi field isolates (fish and bivalve species) with V. harveyi reference strains and other 22 species of the family Vibrionaceae. The phenotypic evaluation was based on macromethod and micromethod (API20E) tests and growth on TCBS and CHROMagar Vibrio. Molecular analysis employed the sequencing of the housekeeping pyrH gene, and the species-specific amplification of the toxR gene. The protein profile was determined by MALDI-TOF analyzing the ribosomal protein content. The antibiotic susceptibility profile was evaluated on 51 V. harveyi strains, isolated from clinical episodes or environmental samples, applying the Kirby-Bauer method and determination of the minimum inhibitory concentration (MIC). The pathogenicity of different V. harveyi isolates in sea bass was investigated by experimental infections (immersion and intraperitoneal IP injection) and the induced anatomo-histopathological lesions were evaluated. A vaccine protocol based on a polyvalent bacterin was also developed to be administered by immersion or by IP, enriched with extracellular extract and emulsified or not with adjuvant. Safety tests and vaccine efficacy were carried out by determining the relative survival rate (RPS) for the various protocols. An indirect ELISA method was developed to compare the immune response (serum IgM) of the specimens vaccinated with the different protocols, highlighting a significantly greater response in the specimens inoculated IP with adjuvant vaccine.
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Nygren, Erik. "A mouse model for direct evaluation of cholera vaccines /". Göteborg : Dept. of Microbiology and immunology, Institute of Biomedicine, The Sahlgrenska Academy at University of Gothenburg, 2009. http://hdl.handle.net/2077/19376.
Testo completo
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Falklind, Jerkérus Susanna. "Vibrio cholerae O139 : identification, characterization and vaccine strategies /". Stockholm, 2003. http://diss.kib.ki.se/2003/91-7349-696-0/.
Testo completo
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Sheikh, Md Arif. "Structural biology of Vibrio cholerae pathogenicity factors". Thesis, St Andrews, 2009. http://hdl.handle.net/10023/696.
Testo completo
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Weber, Barbara. "Stress response and virulence in Vibrio anguillarum". Doctoral thesis, Umeå : Institutionen för molekylärbiologi (Teknisk-naturvetenskaplig fakultet), Umeå universitet, 2010. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-33269.
Testo completo
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Themptander, Katarina. "Detection and characterisation of Vibrio harveyi isolates". Thesis, Uppsala University, Department of Medical Biochemistry and Microbiology, 2005. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-6160.
Testo completoAbstract (sommario):
Aim Because of the major problems that certain Vibrio specie, especially Vibrio harveyi, can cause the aquaculture industries a rapid method to identify Vibrio isolates is required. Early diagnosis of a V. harveyi infection could facilitate disease surveillance, treatment and prevention in cultured marine animals. Therefore, the use of PCR to aid in the identification of Vibrio is increasing and a way of extracting DNA in a cheap, fast and easy way is also of an important requirement to facilitate rapid diagnosis.
Methods This report comprises biochemical profiling and PCR methods in the characterisation of four isolates of V. harveyi and single isolates of V. tubiashii, V. alginolyticus, V. anguillarum, V. splendidus, V. tapetis and V. parahaemolyticus.
Strains were examined for adherence to a Hep-2 cell line. Four different DNA extraction methods were evaluated and compared. The detection limits and the analytical limits of two PCR methods for Vibrio were determined.
Results The overall findings were that the use of a greater range of biochemical substrates than are in the API 20E is necessary to identify Vibrio strains, and that none of the strains tested adhered to Hep-2 cells. All extraction methods successfully produced DNA with the kit method giving the purest samples. RNA was a contaminant of the other techniques but this could be overcome by treating extracts with RNase. The rapid microwave extraction method gave appropriate PCR amplicons when tested.
Conclusion PCR determination of the VH-sequence in combination with VHA and a distinguishable colonial morphology may be a good choice for the identifying of Vibrio harveyi.
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Chen, Desheng, e chen desheng@deakin edu au. "Development of monoclonal antibodies against Vibrio pathogens". Deakin University. Department of Biological Science, 1991. http://tux.lib.deakin.edu.au./adt-VDU/public/adt-VDU20080626.140825.
Testo completoAbstract (sommario):
Monoclonal antibodies were developed against pathogenic vibrios for use in rapid identification in disease situations of humans, fish and shellfish. Of the 12 fusions performed using V. alginolyticus, V. anguillarum, V. carchariae, V. cholerae, V. damsela, V. furnissii, V. harveyi, V. ordalii, V. parahaemolyticus and V. vulnificus, a total of 102 hybridomas were obtained. Based on cross-reactivity of a wide range of Vibrio strains and other gram-negative bacteria, three broad types of monoclonal antibodies were found. The three categories were: (1) ones that were species-specific or specific to a particular surface antigen, (2) a large number that reacted with several Vibrio species, and (3) three that reacted with most Vibrio strains but no other gram-negative bacteria.
Each species-specific monoclonal antibody only recognized its corresponding Vibrio species and was used for identifying unknown species, confirming diagnosis of clinical isolates. In addition, several monoclonal antibodies only cross-reacted with similar Vibrio species, e.g. V. parahaemolyticus and V. alginolyticus which share a common H-antigen. Monoclonal antibodies reacting with several Vibrio species were not of particular use in diagnostic situations. Three monoclonal antibodies of the last group did not react with other genera of the family Vibrionaceae, namely Aeromonas, Photobacterium and Plesiomonas nor a wide range of gram-negative enteric bacteria. These data indicated the existence of an antigenic surface determinant common to Vibrio species. One monoclonal reacted with the heat-stable antigenic determinants on the cell surface as v as lipopolysaccharide extracted from all the vibrios studied, thus making it useful for large- scale screening of acute infections of vibrios.
In a blind test, seven Vibrio species, isolated from 6 marine and a freshwater source were identified by two laboratories using phenetic tests. Results of immunotyping using monoclonals, three of seven were diagnosed as the same species, another three were designated as Vibrio species but could not be classified further due to the library not having the corresponding monoclonal, and one was diagnostically questionable. Two further tests were carried out. An unknown Vibrio formalin-fixed isolated from diseased marine animal was identified as
V. parahaemolyticus by ELISA and FITC. Clinical human isolates of V. alginolyticus, V. parahaemolyticus and V. vulnificus were confirmed by monoclonals.
Australian isolates of V. anguillarum appeared to be mostly of serotype O1. monoclonals raised to V. anguillarum AFHRL 1 reacted with only serotype O1 from Denmark but also most Australian isolates.
All vibrios pathogenic to fish and shellfish, i.e. V. anguillarum, V. ordalii, V. alginolyticus, V. carchariae, V. cholerae, V. damsela, V. harveyi, V. parahaemolyticus and V. vulnificus, were used for attachment studies to fish cells using phase contrast and FITC-immunofluorescence microscopy. Of these vibrios, V. anguillarum, V. ordalii and V. perahaemolyticus, were found to adhere to different cells and tissues of rainbow trout while others did not appear to attach. However, attachment was inhibited by monoclonal antibodies specific to only these three vibrios.
Lipopolysaccharide is well known as being a contributing factor in pathogenicity of gram-negative bacteria. PAGE electrophoresis of extracted LPS from 9 strains covering 6 Vibrio species showed the presence of a common 15,000 D fragment. This fragment was verified by immunoblotting with a genus-specific monoclonal antibody (i.e. F11P411F) recognizing nearly all vibrios. The common LPS fragment was separated and used to raise polyclonal antisera in mouse which reacted strongly with LPS itself, live as well as sodium azide-killed vibrios, but not with other gram-negative bacteria. This raised the possibility of developing vaccine from Vibrio LPS.
Monoclonal antibodies developed in the present study enabled rapid identification of a number of pathogenic Vibrio species. There is still further work to produce monoclonal antibodies against additional vibrios that are probably pathogenic. These included V. fluvialis, V. hollisae, V. metschnikovii, V. minicus, V. salmonella and V. tubiashii. Together the application will be of significance in clinical diagnostic work, in the monitoring of vibriosis in fish farms and in quarantine.
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Focareta, Tony. "The extracellular DNase(s) of vibrio cholerae /". Title page, abstract and table of contents only, 1989. http://web4.library.adelaide.edu.au/theses/09PH/09phf652.pdf.
Testo completo
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Sharma, Dharam Pal. "Non-lipopolysaccharide protective antigens of Vibrio cholerae /". Title page, abstract and contents only, 1990. http://web4.library.adelaide.edu.au/theses/09PH/09phs5314.pdf.
Testo completo
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Lin, Leo Yen-Cheng. "Flavin binding site in Vibrio harveyi Luciferase". Thesis, McGill University, 2004. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=85083.
Testo completoAbstract (sommario):
Luciferase catalyzes the emission of blue-green light and is the central feature of bacterial bioluminescence. The three-dimensional structure of the bacterial luciferase apo-enzyme determined by X-ray crystallography has revealed the detailed landscape of the enzyme active site, however, the absence of a structure with bound substrate has impeded the understanding of the enzyme mechanism by which luciferase interacts with substrates and catalyzes their conversion into light emission. This thesis describes three research projects that focus on the molecular conformation of flavin in the active site of bacterial luciferase. Based on available structure-activity data as guidance, the first project deduces the binding conformation of the luciferase bound flavin by computer modeling. The second research project investigates the binding microenvironment of flavin, and assigns specific functions to the structural modules (amino acid residues), which coordinate flavin in the proposed model. The third project verifies the validity of the proposed model with mutational analysis of the binding site residues, and points out the possibility of altering the visible emission color of bacterial bioluminescence by redesigning luciferase. The last chapter concludes the thesis with the discussion of the structural mechanism of luciferase catalysis, and the perspectives for the engineering of luciferase variants that emit different light colors.
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Abbas, Tanveer. "Activity of tea polyphenols against vibrio species". Thesis, University of Surrey, 2011. http://epubs.surrey.ac.uk/804440/.
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Trubitsyn, Denis. "Magnetosome formation in marine vibrio MV-1". Thesis, University of Edinburgh, 2010. http://hdl.handle.net/1842/7589.
Testo completoAbstract (sommario):
Marine vibrio MV-1 is a magnetotactic bacterium capable of aligning its cell in response to the Earth’s magnetic field. This ability is due to the presence of chainlike structures comprising magnetosomes, magnetite particles enclosed in a lipid membrane with associated proteins. Strain MV-1 differs from other, bettercharacterized strains of magnetotactic bacteria as the cells produce higher amounts of biomagnetite per litre of culture and its magnetosomes are unique in shape. This study investigates the presence and organisation of a gene cluster termed a “magnetosome island” within the genome of MV-1. In other magnetotactic bacteria this genomic region has been shown to contain many of the genes associated with magnetosome formation but has not been previously investigated for MV-1. One of the conserved fragments of this region was amplified using degenerate primers followed by extension of the known sequence using inverse PCR based technique and constructing plasmid libraries. Sequencing of the genome of strain MV-1 was accomplished as a part of this study. Significant work was done on comparison of the sequence quality obtained from SOLEXA, 454 and Sanger sequencing technologies. A number of obtained contigs were joined manually and the resulting sequence was automatically annotated using RAST. The obtained genome sequence of 3.6 Mb with a G+C content of 54.3 % was preliminarily analysed and used to search for magnetosome related genes. This study also analysed proteins associated with the magnetosomes of strain MV-1 using MALDI-TOF, LC-MS and Orbitrap mass spectrometry. These approaches allowed the identification of a number of proteins in the isolated magnetosome membrane fraction. Some of these proteins have very low similarity with other characterized proteins (either in magnetotactic bacteria or in other organisms). Another significant point is that genes that code for proteins such as MamR, MamK and MmsF were found to be present in several homologous copies within the “magnetosome island” of MV-1. Interestingly, this study shows that all homologous copies of these proteins were identified in the magnetosome membrane fraction. Generation of knock-out mutants of several specific genes from the “magnetosome island” of strain MV-1 was attempted; constructs were made based on suicide plasmids carrying the cre-lox or I-SceI systems. Despite altering numerous experimental conditions it was not possible to obtain conclusive evidence of the isolation of MV-1 transconjugants containing the integrated constructs. In order to investigate the cell localization of the magnetosome associated protein CAV30779.1, an enhanced green fluorescent protein (EGFP) fusion based construct was generated and transferred into MV-1 cells. The EGFP fluorescent protein fusions within the cells were detected by microscopy. This study reveals novel information about magnetosome formation in marine vibrio MV-1. The obtained results provide an important foundation for further investigation of this organism and contribute towards broadening the knowledge of the complex process of magnetosome formation in bacteria.
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Sanderson, A. J. "Characterising the CSR system of vibrio anguillarum". Thesis, University of Nottingham, 2006. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.493117.
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Findlay, Gordon. "Biogenesis of virulence factors in Vibrio cholerae". Thesis, University of Kent, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.294636.
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Dawson, Christine A. "Taxonomy and identification of the genus Vibrio". Thesis, University of Leicester, 1986. http://hdl.handle.net/2381/35331.
Testo completoAbstract (sommario):
A probability matrix for computer-assisted identification of vibrios has been constructed, based on the API20E system. Data were gathered from 173 strains representing 31 taxa of vibrios and related organisms, from a variety of sources. The matrix was tested internally by four statistical programs. Program OVERMAT and program MOSTTYP tested the separation and homogeneity of the taxa. Most of the taxa were satisfactory but a few were less so; reasons for this are discussed. Program CHARSEP and program DIACHAR tested the separation and diagnostic values, respectively, of the 50 characters used and from the results a shorter diagnostic test set was drawn up. The overall test error rate was 4.5%. The matrix was assessed externally by its performance in the identification of vibrio-like strains isolated from freshwater. The overall success rate for identification was 84%, using a Willcox score of ?0.99. The data generated for 172 of the reference strains and 243 wild strains were subjected to numerical taxonomic analysis. The main purpose of these analyses was to verify the quality of the identification scheme. Nevertheless the results produced were in good agreement with those of more detailed taxonomic studies. The taxonomic position of some named and some unnamed groups of Vibrio and Aeromonas was clarified, and taxa showing poor distinction were highlighted. An ecological survey was carried out to determine the distribution and seasonal occurrence of vibrios in various freshwater sites in the U.K. The results showed that species of vibrio both pathogenic and non-pathogenic for man, are widely distributed in rivers and canals. Some of the species considered to be indigenous to the waters. The role of these organisms in the freshwater environment remains to be determined.
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Car, Nicholas George. "Studies on stationary phase Vibrio sp. 2". Doctoral thesis, University of Cape Town, 1987. http://hdl.handle.net/11427/21894.
Testo completoAbstract (sommario):
Vibrio sp. 2 stationary phase cells are novel and interesting in that they are able to support phage growth in standing cultures, but not in shaken (aerated) cultures. Many physiological and morphological characteristics change when Vibrio sp. 2 stationary phase cells are removed from aeration: the relatively high levels of protein synthesis (Robb et al., 1977; 1978) decrease, with a concomitant increase in the levels of RNA synthesis; protein degradation rises from 1 %h⁻¹ to 2,9 %h⁻¹, and whilst the average cell length decreases, the range of cell lengths markedly increases. The magic spot nucleotides, ppGpp and pppGpp, which are present in stressed exponential phase Vibrio sp. 2 cells, are not detectable in stationary phase Vibrio cells. The specific proteolytic activity of shaking stationary phase cell-free extracts against the foreign protein [¹⁴C-me]globin was slightly higher than that of extracts from standing or exponential phase cells, while the specific proteolytic activity against [¹²⁵I]-insulin was slightly lower. On the basis of inhibitor studies and subcellular distribution, the proteolytic activities of the three types of extract differed. The addition of exogenous ATP to cell-free extracts either stimulated (Car & Woods, 1984) or depressed proteolytic activity depending on the procedure used to prepare the extracts. The proteolytic activity of fractions containing substantial amounts of membrane material, from all three types of extract, were markedly depressed by ATP. On preincubation of cell-free extracts from exponentially growing cells prior to assay of proteolytic activity, the activity was markedly stimulated (two- to four-fold). The stimulation,. however, varied, greatly between independently produced extracts. ATP had a much smaller stimulatory effect on preparations free of cell wall material from both types of stationary phase cells (the stimulation was less than two-fold), and the stimulation was not affected by preincubation of the extracts. Extracts prepared from starving cells, previously in exponential growth, were affected by the addition of ATP in a similar manner to that observed with stationary phase extracts (Car & Woods, 1984). Exponential and both types of stationary phase Vibrio sp. 2 cells have ATP-stimulated and ATP-depressed activities separable by ion-exchange chromatography, in addition to several other proteolytic activities. All types of Vibrio sp. 2 cells have a similar complement of proteolytic activities.
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Berg, Thorsten. "Virulenzregulationskaskade und Chitobiose-Metabolismus in Vibrio cholerae". Doctoral thesis, kostenfrei, 2008. http://www.opus-bayern.de/uni-wuerzburg/volltexte/2008/2829/.
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Costa, Robert. "Contribution à l'étude du "Syndrome 93", pathologie majeure des crevettes d'élevages (Penaeus stylirostris) en Nouvelle-Calédonie". Lyon 1, 1997. http://www.theses.fr/1997LYO1T248.
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Ogierman, Monica A. "Molecular characterisation of the fungus Corynespora cassicola /". Title page, contents and abstract only, 1998. http://web4.library.adelaide.edu.au/theses/09PH/09pho344.pdf.
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Mutreja, Ankur. "The origins and evolution of Vibro cholerae O1 E1 Tor". Thesis, University of Cambridge, 2014. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.648490.
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Campeão, Mariana Esteves. "Diversidade genômica e diagnostico fenotípico de vibrios". Laboratório Nacional de Computação Cientifica, 2014. https://tede.lncc.br/handle/tede/184.
Testo completoAbstract (sommario):
Made available in DSpace on 2015-03-04T18:58:03Z (GMT). No. of bitstreams: 1
thesisMarianaCampeao.pdf: 13162328 bytes, checksum: ed5b7096328fd1404655a6f926f0f292 (MD5)
Previous issue date: 2014-04-25Vibrios sao bacterias amplamente distribuidas no meio aquatico e podem ser encontradas em associacao com organismos marinhos, tanto como causadores de doencas quanto como simbiontes. O advento das tecnicas de sequenciamento de nova geracao e de alto desempenho tem possibilitado o acesso cada vez mais amplo a dados genomicos microbianos, incluindo vibrios. Tal quantidade e disponibilidade de dados permitem analises in silico, que podem compreender desde caracteristicas genomicas ate fenotipicas. A taxonomia microbiana e fundamentada na abordagem polifasica, que mede as relacoes evolutivas a partir do uso de sequencias de genes, especialmente o RNAr 16S, similaridade genomica, por meio de hibridizacao de DNA, e ampla caracterizacao fenotipica. A caracterizacao fenotipica requer testes experimentais, que muitas vezes sao demorados, caros e requerem grande experiencia. Neste estudo propomos o uso de genomas para a analise da diversidade e identificacao fenotipica de vibrios. Para tanto, foram avaliadas caracteristicas basicas de vibrios (tais como tamanho do genoma, conteudo genico e posicao logenetica); analisaram-se genes unicos e suas possiveis funcoes ecologicas; e desenvolveu-se uma ferramenta prototipo para identificacao de fenotipos diagnosticos de vibrios, denominada vibriophenotyping 1.0. A logenia construida a partir do genoma minimo recuperou os diferentes generos e clados descritos na literatura para o grupo vibrio, bem como posicionou as especies consideradas irmas em relacao a um ancestral comum proximo. Os genes unicos, por sua vez, puderam ainda revelar peculiaridades entre especies irmas. Por m, o programa de identificacao fenotipica desenvolvido foi testado com genomas de linhagens tipo de vibrios e apresentou uma media de similaridade superior a 70% entre os fenotipos obtidos in vitro e in silico, sendo alcançada uma similaridade de 100% para genomas integros. Dessa forma, concluiu-se que analises do pangenoma permitem a recontrucao logenetica dentro do grupo vibrios e a identificacao de genes unicos relevantes para o papel ecologico da especie no ambiente de origem, e, ainda, que a identificacao fenotipica atraves da automatizacao por uma ferramenta computacional e possivel a partir da analise de genomas.
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Luo, Xing. "Roles of regulatory RNAs in Vibrio pathogenic to species of aquaculture interest". Thesis, Université Paris-Saclay (ComUE), 2019. http://www.theses.fr/2019SACLS226.
Testo completoAbstract (sommario):
Les petits ARN régulateurs bactériens, généralement de 50 à 300 nt de long, agissent en appariant les bases avec des cibles d'ARNm spécifiques, affectant ainsi leur traduction et/ou leur stabilité, sont des éléments importants qui régulent divers processus. V. tasmaniensis LGP32 est un pathogène de l'huître facultatif. Un ARNs Vsr217 s'est révélé être conservé dans les vibrions et fortement régulé à la hausse lors de l'infection des huîtres. J'ai trouvé que vsr217 et le gène en aval malK (codant pour une sous-unité du transporteur principal de maltose) sont tous deux exprimés à partir d'un promoteur en amont régulé par l'activateur de maltose MalT, Vsr217 étant généré à partir de la longue 5' UTR de l'ARNm de malK. Outre un effet cis sur l’expression du malK, qui diminue chez le mutant Δvsr217, nous avons constaté que l’absence de cet ARNs entraînait, lors de la croissance de cellules dans du maltose, l’augmentation de deux enzymes importantes impliquées dans la voie de la glycolyse/néoglucogenèse, Fbp et PpsA et cet ARNm de fbp étaient une cible directe de Vsr217. J'ai également exploré la régulation de la biosynthèse des acides aminés à chaîne ramifiée (BCAA: Leucine, Valine et Isoleucine) chez V. alginolyticus, un agent pathogène des poissons et mollusques et des poissons de mer et un agent pathogène humain émergent opportuniste. Nous avons constaté que l'opéron ilvGMEDA (codant la voie principale pour la biosynthèse des BCAAs) est régulé par un peptide leader traduit. Ainsi, la traduction d'un peptide riche en BCAA codé en amont des gènes de structure fournit une réponse adaptative par un mécanisme similaire au modèle canonique de E. coli. Cette étude portant sur un organisme non modèle à Gram-négatif met en évidence la conservation mécanistique de l'atténuation de la transcription malgré l'absence de conservation de la séquence primaireBacterial regulatory small RNAs, usually 50-300 nt long, act by base-pairing with specific mRNA targets, affecting their translation and/or stability, are important elements which regulate a variety of processes. V. tasmaniensis LGP32 is a facultative oyster pathogen. A sRNA Vsr217 was found to be conserved within vibrios and highly upregulated during oyster infection. I found that vsr217 and the downstream gene malK (encoding a subunit of the major maltose transporter) are both expressed from an upstream promoter regulated by the maltose activator MalT with Vsr217 being generated from the long 5' UTR of the malK mRNA. Beside a cis-effect on malK expression, which decreases in the Δvsr217 mutant, we found that the absence of this sRNA resulted, when cells grown in maltose, in the increase of two important enzymes involved in the glycolysis/neoglucogenesis pathway, Fbp and PpsA and that fbp mRNA was a direct target of Vsr217. I also explored the regulation of the biosynthesis of branched-chain amino acids (BCAAs: Leucine, Valine and Isoleucine) in V. alginolyticus, a marine fish and shellfish pathogen and an emerging opportunistic human pathogen. We found that the ilvGMEDA operon (encoding the main pathway for biosynthesis of BCAAs) is regulated by a translated leader peptide. Thus, the translation of a BCAA rich peptide encoded upstream of the structural genes provides an adaptive response by a mechanism similar to the E. coli canonical model. This study with a non-model Gram-negative organism highlights the mechanistic conservation of transcription attenuation despite the absence of primary sequence conservation
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Navarro, Romain. "Etude structurale par RMN de la protéine TolAIII impliquée dans le mécanisme d'infection de Vibrio cholerae par le bactériophage CTXphi". Thesis, Aix-Marseille, 2016. http://www.theses.fr/2016AIXM4079.
Testo completoAbstract (sommario):
Vibrio cholerae acquiert les gènes de la toxine cholérique suite à l’infection par le phage CTXphi et devient par la suite une bactérie pathogène. L'infection se déroule en deux étapes : une interaction entre le pilus TCP et le domaine pIIIN2ctx, puis la formation du complexe TolAIIIV.c/pIIIN1ctx. Cette seconde étape est l’étape limitante de l’infection. L’objectif général de ma thèse a été d’étudier les forces motrices associées à cette étape.1) J’ai étudié les mécanismes moléculaires associés à la spécificité phage/bactérie en ciblant les interactions électrostatiques et le feuillet intermoléculaire par RMN et double hybride bactérien.2) J’ai résolu la structure de TolAIIIV.c libre par RMN. La comparaison des structures de cette protéine à l’état libre et liée ont permis de mettre en évidence un changement conformationnel et de proposer un mécanisme moléculaire d’ajustement induit. De plus, l’étude de la flexibilité de la protéine par RMN à haute pression (HP) a montré l’importance de la cavité interne de la protéine TolAIII pour favoriser l’ajustement induit lors de la formation du complexe TolAIIIV.c/pIIIN1CTX.3) J’ai vérifié si l’ajustement induit observé précédemment était lié à la présence de cette cavité d’une manière générale chez les protéines TolAIII. Une étude de dispersion de relaxation et de RMN à HP de la protéine TolAIIIE.c a permis de vérifier l’importance de cette cavité pour le mécanisme d’ajustement induit essentiel à cette famille de protéine. De plus, nous avons corrélée la flexibilité particulière de la protéine TolAIIIE.c à la présence d’une boucle qui lui confère une certaines flexibilité nécessaires pour interagir avec plusieurs partenairesVibrio cholerae becomes a pathogen after CTXphi phage infection. The phagic infection is a wo step mechanism: first TCP pilus binds to pIIIN2ctx, then TolAIIIV.c binds to pIIIN1ctx. The second step is essential for the acquisition of genes of cholera toxins leading to cholera disease. The main goal of my thesis is to study the driving forces associated to the phage infection.First, I studied the molecular mechanism associated to phage/bacteria specificity targeting electrostatic bonds and hydrophobic interactions within the intermolecular sheet. These experiments use NMR and bacterial two hybrids methods. Our results show that electrostatic bonds are essential for the complex formation.Second, I solved the solution structure of TolAIIIV.c using NMR. The comparison of the structures of free and bound states of TolAIIIV.c, shows an associate conformational change and lead us to propose a model for the molecular mechanism of the induced fit. Then the study of the TolAIII flexibility, using high pressure NMR shows the importance of TolAIII cavity to promote the induced fit during TolAIIIV.c/pIIIN1ctx complex formation.Finally, we wanted to show if the induced fit is correlated to the presence of cavity in TolAIII family. A study using NMR relaxation dispersion and high-pressure NMR experiments on TolAIIIE.c shows the importance of this cavity for the induced fit. The presence of a loop at the top of the N-terminal helix in TolAIIIE.c leads to the protein to have several conformations necessary to interact with many partners
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Wang, Yanling, e 王{227b76}[ling]. "Isolation and characterization of environmental vibrio species from Mai Po Nature Reserve, Hong Kong". Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2003. http://hub.hku.hk/bib/B29232028.
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Carvalho, Edirsana Maria Ribeiro de. "QuantificaÃÃo e identificaÃÃo de Vibrio spp. na hemolinfa de camarÃes Litopenaeus vannamei cultivados em fazendas no Estado do CearÃ". Universidade Federal do CearÃ, 2009. http://www.teses.ufc.br/tde_busca/arquivo.php?codArquivo=8015.
Testo completoAbstract (sommario):
FundaÃÃo Cearense de Apoio ao Desenvolvimento Cientifico e TecnolÃgicoAs infecÃÃes bacterianas em camarÃes sÃo causadas, freqÃentemente, por bactÃrias do gÃnero Vibrio O presente estudo teve por objetivo quantificar e identificar Vibrio na hemolinfa do camarÃo marinho Litopenaeus vannamei cultivado em fazendas no Estado do CearÃ, Brasil. Relacionou-se tambÃm o tempo de coagulaÃÃo das hemolinfas com as contagens de Vibrio. Foram realizadas 16 coletas em quatro fazendas (A, B, C e D), sendo oito para camarÃes com 4 g, e oito para camarÃes com oito gramas. As coletas foram realizadas nos perÃodos sazonais: chuvoso e estiagem. Perfazendo um total de 480 amostras, sendo 240 para camarÃes com 4 g e 8 g cada, respectivamente. Os valores da Contagem PadrÃo em Placas (CPP) de vÃbrios totais, de vÃbrios Sac+ e Sac-, nas amostras de hemolinfa dos camarÃes com 4g, no perÃodo chuvoso, variaram de: 2,74 x 104 a 28,70 x 106 UFC/mL (est.); de < 6,0 a 14,64 x 106UFC/mL e de < 6,0 a 12,72 x 106 UFC/mL, respectivamente. Para a hemolinfa dos camarÃes com 8 g os valores obtidos foram: 1,68 x 104 a 15,18 x 106 UFC/mL (est.), de < 6,0 a 1,8 x 105 UFC/mL e de < 6,0 a 15,18 x 106UFC/mL (est.), respectivamente. No perÃodo de estiagem esses valores para a hemolinfa dos camarÃes de quatro gramas, foram: 9,0 x 102 (est.) a 5,40 x 104 UFC/mL vÃbrio total; < 6,0 a 1,71 x 10⁴UFC/mL (Sacâ) e de < 6,0 a 5,40 x 104 UFC/mL (Sac+). Para os camarÃes com 8 g a contagem de VÃbrio total foi de 9,0 x 102 (est.) a 2,0 x 107, de < 6,0 a 4,02 x 106 UFC/mL (Sac-) e de < 6,0 a 2,0 x 10⁷ UFC/mL (est.) (Sac +). Os resultados mostram que os Ãndices de colÃnias de Vibrio Sac- e Sac+ foram maiores no perÃodo chuvoso do que no de estiagem. NÃo houve relaÃÃo entre o tempo de coagulaÃÃo e as contagens de Vibrio na hemolinfa dos camarÃes. As espÃcies que predominaram nos perÃodos estudados foram: V. coralliilyticus, V. parahaemolyticus, Vibrio pelagius II, Vibrio alginolyticus, Vibrio mediterranei, Vibrio mimicus, Vibrio vulnificus B1.
Most of shrimp bacterial infections are caused by Vibrio bacteria genus. This study aims to quantify identify Vibrio in the hemolymph of the marine shrimp Litopenaeus vannamei cultivated in farms in State of Cear, Brazil. Related is also the time of coagulation of hemolymph with counts of Vibrio. Sixteen samples were performed on four farms (A, B, C and D), eight shrimps with 4 g, and eight with eight grams shrimps. The collections were made in seasonal periods: rainy and drought. A total of 480 samples, and 240 to shrimps with 4 g and 8 g each, respectively. The values in the Standard Plate Count (SPC) of total vibrio, Vibrio Suc+ and Suc- in the hemolymph of shrimp samples with 4 g, in the rainy season ranged from: 2. 74 x 10⁴ to 28.70 x 10⁶ CFU/mL (est.), <6.0 to 14.64 x 106CFU/mL and <6.0 to 12.72 x 106 CFU/mL, respectively. For hemolymph of shrimp with 8 g of the SPC and the total Vibrio Suc+ and Sucranged from 1.68 x 10⁴ to 15.18 x 10⁶ CFU/mL (est.), <6.0 to 1.8 x 105 CFU/mL and <6.0 to 15.18 x 106CFU/mL (est). During the period of drought for these values of shrimp haemolymph of four grams, were: 9.0 x 10Â (est.) to 5.40 x 104 CFU mL total Vibrio, <6.0 to 1.71 x 10⁴CFU/mL (Suc-) and <6.0 to 5.40 x 104 CFU/mL (Suc+). For shrimp with 8 g a total Vibrio count was 9.0 x 10Â (est.) CFU/mL to 2.0 x 10⁷, <6.0 to 4.02 x 106 CFU/mL (Suc-) and <6.0 to 2.0 x 10⁷CFU/mL (est.) (Suc+). The results show that the rates of colonies of Vibrio Suc- and Suc+ were higher in the rainy season than in the drought. There was no relationship between the time of coagulation and the counts of Vibrio in the hemolymph of shrimps. The species that predominated in the period were: V. coralliilyticus, V. parahaemolyticus, Vibrio pelagius II, Vibrio alginolyticus, Vibrio mediterranei, Vibrio mimicus, Vibrio vulnificus B1
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Amarante, Deborah Oliveira. "Viabilidade de agentes bacterianos como probiÃtico no cultivo do camarÃo marinho Litopenaeus vannamei". Universidade Federal do CearÃ, 2016. http://www.teses.ufc.br/tde_busca/arquivo.php?codArquivo=17243.
Testo completoAbstract (sommario):
CoordenaÃÃo de AperfeÃoamento de Pessoal de NÃvel SuperiorOs probiÃticos surgiram como alternativa ao uso de antibiÃticos no controle de bactÃrias patogÃnicas. Buscando alternativas para reduzir as vibrioses surgiu a utilizaÃÃo das bactÃrias do gÃnero Bacillus como prevenÃÃo para o aparecimento de enfermidades. O objetivo principal desta pesquisa foi testar a viabilidade e eficiÃncia de bactÃrias isoladas do trato intestinal de crustÃceos saudÃveis como agentes probiÃticos no cultivo do camarÃo Litopenaeus vannamei. Foram testadas 17 cepas do gÃnero Bacillus e uma cepa do gÃnero Paenibacillus, pertencentes Ãs seguintes espÃcies: B. circulans (n=1), B. megaterium (n=1), B. subtilis (n=2), B. cereus (n=2), B. thuringiensis (n=2), Bacillus sp. (n=9) e P. agaridevorans (n=1). Foram realizados testes de atividade da tolerÃncia à temperatura, viabilidade sob diferentes concentraÃÃes de pH e tolerÃncia ao NaCl. Foi realizado o teste de susceptibilidade a antimicrobianos e da anÃlise da presenÃa ou ausÃncia de alguns fatores de virulÃncia. O teste de inibiÃÃo de patÃgenos foi feito de duas formas: atravÃs de plugs de Ãgar e por intermÃdio de estrias cruzadas (cross streak). A capacidade de agregaÃÃo foi verificada por meio do teste de aderÃncia ao vidro. O experimento in vivo foi realizado utilizando camarÃes Litopenaeus vannamei com peso mÃdio de 10 g. O delineamento experimental foi totalmente ao acaso e foram suplementados da seguinte forma: Tratamento A: controle (sem suplementaÃÃo); Tratamento B: uma cepa por aspersÃo; Tratamento C: mix bacteriano por aspersÃo; Tratamento D: uma cepa bioencapsulada em alginato de sÃdio; Tratamento E: mix bacteriano bioencapsulado em alginato de sÃdio. A alimentaÃÃo foi ofertada ad libitum trÃs vezes ao dia por 30 dias. A biometria dos animais foi feita a cada 10 dias. Passados os 30 dias de alimentaÃÃo, os camarÃes foram desafiados frente ao patÃgeno Vibrio harveyi. Foi realizada a Contagem PadrÃo em Placas (CPP) de Vibrio e Bacillus do intestino e do conteÃdo intestinal, antes e apÃs a infecÃÃo do sistema. A maioria das cepas testadas apresentaram potencial para uso como probiÃticos em carcinicultura. O peso final foi estatisticamente superior ao peso inicial para os tratamentos A, B, D e E (p<0,05). Os tratamentos que utilizaram as bactÃrias do gÃnero Bacillus apresentaram crescimento reduzido das bactÃrias do gÃnero Vibrio apÃs a infecÃÃo. Com os resultados encontrados neste trabalho à sugerida a realizaÃÃo de estudos complementares da potencialidade probiÃtica das cepas de Bacillus no controle de Vibrio, minimizando os efeitos deste patÃgeno na carcinicultura.
Probiotics have emerged as an alternative to antibiotics in the control of pathogenic bacteria. Seeking alternatives to reduce Vibrio infections comes the use of bacteria of the genus Bacillus as prevention for the onset of diseases. The main objective of the research was to test the feasibility and efficiency of bacteria isolated from the intestinal tract of healthy shellfish such as probiotic agents in the cultivation of Litopenaeus vannamei. Were tested 17 strains of the genus Bacillus and a strain of genus Paenibacillus, of the following species: B. circulans (n = 1), B. megaterium (n = 1), B. subtilis (n = 2), B. cereus ( n = 2), Bacillus thuringiensis (n = 2), Bacillus sp. (n = 9) and P. agaridevorans (n = 1). The temperature tolerance activity tests were conducted under different concentrations viability pH and tolerance to NaCl. The susceptibility testing to antibiotics and analysis of the presence or absence of some virulence factors was performed. The inhibition test was done to pathogens in two ways: using agar plugs and through cross-striations (cross streak). The aggregation ability was observed through the glass adhesion test. In vivo experiment was performed using Litopenaeus vannamei shrimp with average weight of 10 g. The experimental design was completely at random and were supplemented as follows: Treatment A: control (no supplementation); Treatment B: a strain sprinkler; Treatment C: Bacterial mix spray; Treatment D: A Strain bioencapsulated sodium alginate; Treatment E: Bacterial mix bioencapsulated sodium alginate. The feed was offered ad libitum three times a day for 30 days. Biometrics animal was taken every 10 days. After 30 days of feeding, the shrimp were challenged against the pathogen Vibrio harveyi. Standard plate count (SPC) was performed to Vibrio and Bacillus from gut and intestinal contents before and after the infection of the system. Most of the strains showed potential for use as probiotics in shrimp farming. The final weight was statistically superior to the initial weight for treatments A, B, D and E (p <0.05). The treatments of bacteria of the genus Bacillus reduced growth of bacteria of the genus Vibrio after infection. Thus, it suggested to carry out further studies of potential probiotic strains of Bacillus sp. in the control of Vibrio, minimizing the effects of this pathogen in shrimp farming.
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Amarante, Deborah Oliveira. "Viabilidade de agentes bacterianos como probiótico no cultivo do camarão marinho Litopenaeus vannamei". reponame:Repositório Institucional da UFC, 2016. http://www.repositorio.ufc.br/handle/riufc/18688.
Testo completoAbstract (sommario):
AMARANTE, Deborah Oliveira. Viabilidade de agentes bacterianos como probiótico no cultivo do camarão marinho Litopenaeus vannamei. 2016. 54 f. : Dissertação (mestrado) - Universidade Federal do Ceará, Centro de Ciências Agrárias, Departamento de Engenharia de Pesca, Fortaleza-CE 2016Submitted by Nádja Goes (nmoraissoares@gmail.com) on 2016-07-25T12:59:38Z No. of bitstreams: 1 2016_dis_doamarante.pdf: 1020688 bytes, checksum: 0e9a0df944198bacc3311bb495290af9 (MD5)
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Made available in DSpace on 2016-07-25T12:59:52Z (GMT). No. of bitstreams: 1 2016_dis_doamarante.pdf: 1020688 bytes, checksum: 0e9a0df944198bacc3311bb495290af9 (MD5) Previous issue date: 2016
Probiotics have emerged as an alternative to antibiotics in the control of pathogenic bacteria. Seeking alternatives to reduce Vibrio infections comes the use of bacteria of the genus Bacillus as prevention for the onset of diseases. The main objective of the research was to test the feasibility and efficiency of bacteria isolated from the intestinal tract of healthy shellfish such as probiotic agents in the cultivation of Litopenaeus vannamei. Were tested 17 strains of the genus Bacillus and a strain of genus Paenibacillus, of the following species: B. circulans (n = 1), B. megaterium (n = 1), B. subtilis (n = 2), B. cereus ( n = 2), Bacillus thuringiensis (n = 2), Bacillus sp. (n = 9) and P. agaridevorans (n = 1). The temperature tolerance activity tests were conducted under different concentrations viability pH and tolerance to NaCl. The susceptibility testing to antibiotics and analysis of the presence or absence of some virulence factors was performed. The inhibition test was done to pathogens in two ways: using agar plugs and through cross-striations (cross streak). The aggregation ability was observed through the glass adhesion test. In vivo experiment was performed using Litopenaeus vannamei shrimp with average weight of 10 g. The experimental design was completely at random and were supplemented as follows: Treatment A: control (no supplementation); Treatment B: a strain sprinkler; Treatment C: Bacterial mix spray; Treatment D: A Strain bioencapsulated sodium alginate; Treatment E: Bacterial mix bioencapsulated sodium alginate. The feed was offered ad libitum three times a day for 30 days. Biometrics animal was taken every 10 days. After 30 days of feeding, the shrimp were challenged against the pathogen Vibrio harveyi. Standard plate count (SPC) was performed to Vibrio and Bacillus from gut and intestinal contents before and after the infection of the system. Most of the strains showed potential for use as probiotics in shrimp farming. The final weight was statistically superior to the initial weight for treatments A, B, D and E (p <0.05). The treatments of bacteria of the genus Bacillus reduced growth of bacteria of the genus Vibrio after infection. Thus, it suggested to carry out further studies of potential probiotic strains of Bacillus sp. in the control of Vibrio, minimizing the effects of this pathogen in shrimp farming.
Os probióticos surgiram como alternativa ao uso de antibióticos no controle de bactérias patogênicas. Buscando alternativas para reduzir as vibrioses surgiu a utilização das bactérias do gênero Bacillus como prevenção para o aparecimento de enfermidades. O objetivo principal desta pesquisa foi testar a viabilidade e eficiência de bactérias isoladas do trato intestinal de crustáceos saudáveis como agentes probióticos no cultivo do camarão Litopenaeus vannamei. Foram testadas 17 cepas do gênero Bacillus e uma cepa do gênero Paenibacillus, pertencentes às seguintes espécies: B. circulans (n=1), B. megaterium (n=1), B. subtilis (n=2), B. cereus (n=2), B. thuringiensis (n=2), Bacillus sp. (n=9) e P. agaridevorans (n=1). Foram realizados testes de atividade da tolerância à temperatura, viabilidade sob diferentes concentrações de pH e tolerância ao NaCl. Foi realizado o teste de susceptibilidade a antimicrobianos e da análise da presença ou ausência de alguns fatores de virulência. O teste de inibição de patógenos foi feito de duas formas: através de plugs de ágar e por intermédio de estrias cruzadas (cross streak). A capacidade de agregação foi verificada por meio do teste de aderência ao vidro. O experimento in vivo foi realizado utilizando camarões Litopenaeus vannamei com peso médio de 10 g. O delineamento experimental foi totalmente ao acaso e foram suplementados da seguinte forma: Tratamento A: controle (sem suplementação); Tratamento B: uma cepa por aspersão; Tratamento C: mix bacteriano por aspersão; Tratamento D: uma cepa bioencapsulada em alginato de sódio; Tratamento E: mix bacteriano bioencapsulado em alginato de sódio. A alimentação foi ofertada ad libitum três vezes ao dia por 30 dias. A biometria dos animais foi feita a cada 10 dias. Passados os 30 dias de alimentação, os camarões foram desafiados frente ao patógeno Vibrio harveyi. Foi realizada a Contagem Padrão em Placas (CPP) de Vibrio e Bacillus do intestino e do conteúdo intestinal, antes e após a infecção do sistema. A maioria das cepas testadas apresentaram potencial para uso como probióticos em carcinicultura. O peso final foi estatisticamente superior ao peso inicial para os tratamentos A, B, D e E (p<0,05). Os tratamentos que utilizaram as bactérias do gênero Bacillus apresentaram crescimento reduzido das bactérias do gênero Vibrio após a infecção. Com os resultados encontrados neste trabalho é sugerida a realização de estudos complementares da potencialidade probiótica das cepas de Bacillus no controle de Vibrio, minimizando os efeitos deste patógeno na carcinicultura.
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Daniels, Kathy. "Characterisation of O-antigen biosynthesis genes in Vibro anguillarum and their association with IS1358 /". Title page, abstract and table of contents only, 1999. http://web4.library.adelaide.edu.au/theses/09PH/09phd1861.pdf.
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Labreuche, Yannick. "Caractérisation de la virulence d'une souche de Vibrio aestuarianus, pathogène de l’huître Crassostrea Gigas". Brest, 2006. http://www.theses.fr/2006BRES2049.
Testo completoAbstract (sommario):
En France, l’ostréiculture constitue la 1ère production de mollusques et repose sur l’huître creuse Crassostrea gigas. Depuis les années 80, les ostréiculteurs sont confrontés à des mortalités lors de la période estivale. Des études antérieures ont établi que ce phénomène résultait d’une interaction complexe entre le statut physiologique / génétique de l’huître, des paramètres environnementaux et la présence de microorganismes, dont des bactéries du genre Vibrio. Dans ce contexte, une collection d’isolats bactériens e été constituée à partir d’huîtres moribondes et saines. Les analyses phylogénétiques ont montré que l’espèce V. Aestuarianus représentait plus de 50% des souches isolées en dominance d’huîtres moribondes. Ces souches présentent une virulence variable lors d’infections expérimentales, cette variabilité étant corrélée à la toxicité des produits extracellulaires (ou ECPs). En raison de sa virulence, les mécanismes de pathogénie de la souche 01/32 ont été investigués. L’étude des interactions entre 01/32 et les hémocytes, cellules de défense de l’hôte, a établi que les ECPs présentent un effet létal par injection chez l’huître et inhibent les capacités d’adhésion et de phagocytose des hémocytes. Une approche combinant biochimie et biologie moléculaire a permis de caractériser un gène codant une métalloprotéase zinc-dépendante et d’établir son implication dans la toxicité des ECPs. Son expression en système hétérologue a confirmé son activité létale et son râle dans l’inhibition des capacités d’adhésion et de phagocytose des hémocytes. L’ensemble de ce travail montre le rôle joué par une métalloprotéase dans la pathogenése de V. Aestuarianus 01/32 chez C. GigasIn France, shellfish production is based upon farming of the Pacific oyster, Crassostrea gigas. Since the 80’s, mass mortalities of C. Gigas have been reported during summer. Previous studies have shown that these outbreaks result from complex interactions between me physiological and/or genetic status of the oysters, environmental factors, and one or more infectious agents, including bacteria of the genus Vibrio. In this context, e collection of bacterial strains was isolated from the hemolymph of moribund and healthy oysters. During this study, V. Aestuarianus was the most frequently encountered species. These bacterial isolates exhibited variable virulence alter experimental challenge, this variation being apparently linked to the toxicity of bacterial extracellular products (ECPs). Pathogenicity mechanisms were further investigated on strain 01/32, which induced the highest mortality after experimental challenges. The study of interactions between 01/32 and oyster immune cells revealed the toxicity of ECPs when injected into oysters and their role in the inhibition of hemocyte adhesion and phagocytosis capacities. Biochemical and genetic approaches led to the characterization of a gene encoding a zinc-dependent metalloprotease and to the demonstration of its involvement in the lethal effect of ECPs. When expressed in a heterologous system, the metalloprotease conferred a toxic phenotype on ECPs of the transconjuguant and caused inhibition of hemocyte adhesive and phagocytic activities. Taken together, these results demonstrate me critical rob played by the metalloprotease in pathogenicity mechanisms of V. Aestuarianus 01/32 during experimental infection of C. Gigas oyster
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Meyer, Shelli Lee. "Vibrio vulnificus dynamics in a south Texas bay". [College Station, Tex. : Texas A&M University, 2007. http://hdl.handle.net/1969.1/ETD-TAMU-1587.
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