Dissertations / Theses on the topic 'Vibrios'
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Dias, Graciela Maria. "Genômica comparativa de vibrios." Laboratório Nacional de Computação Científica, 2010. http://www.lncc.br/tdmc/tde_busca/arquivo.php?codArquivo=221.
Full textVibrios genomes are not fully known. This thesis focused on the annotation of four draft genomes ( V. alginolyticus 40B, V. communis 1DA3, V. mimicus VM603 e VM573), the performance comparison of three automated genome annotations (SABIA, RAST and GRC) and the identification of putative unique genes (strain specific genes) in the genomes. The genomes of Vibrios contained between 3,745 and 4,977 genes, of which 2,900 were real genes, 898 were hypothetic conserved genes and 385 were hypothetic genes. The majority of known gene products were related to general functions and unknown functions (R and S), metabolism and amino acid transport (E) and transcription (K) on the basis of the COG (clusters of ortologs group). The comparison of three automated genome annotation systems indicated that each system had advantages and disadvantagens. The SABIA Server revealed interactivity with many biologic databases, such as InterPro and Swiss-Prot. The RAST server was useful for comparative genomics of specific genomes and metagenomes. The GRC server was useful annotation offline as it can be installed and run on a local computer. The genomes of Vibrios showed differences in the genic content revealled by BLAST atlas and BLAST. Each genome showed 289 to 1,432 unique genes, resulting of comparisons with organisms phylogenetically closest related. The comparison of the genomes of V. alginolyticus 40B and V. alginolyticus 12G01 revealed that 40B has 541 unique genes. The comparison of V. communis 1DA3 and V. campbellii ATTC genome revealed 1,432 unique genes in 1DA3. V. mimicus VM573 and VM603 genomes showed 334 and 289 unique genes, respectively. The vast majority of unique genes were related with carbohidrates, stress response, virulence, cell wall and capsule, indicating that this sub-group of genes may be associated with adaptation of strains to differents habitats and ecologic niches.
Campeão, Mariana Esteves. "Diversidade genômica e diagnostico fenotípico de vibrios." Laboratório Nacional de Computação Cientifica, 2014. https://tede.lncc.br/handle/tede/184.
Full textVibrios 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.
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.
Full textNo 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
Robino, Etienne. "Etude des amibes marines et de leurs interactions avec les vibrios pathogènes d’huître." Thesis, Montpellier, 2019. http://www.theses.fr/2019MONTG041.
Full textFree living amoebae inhabit aquatic environments and use phagocytosis of bacteria for their nutrition. According to the hypothesis of coincidental evolution of virulence, the cellular and molecular mechanisms of phagocytosis being preserved from amoebae to the immune cells of animals, the predation exerted by amoebae could favor the emergence of pathogenic bacteria resistant to phagocytosis. Since 2008, Crassostrea gigas oysters have suffered from over-mortality in France. This poly-microbial disease involves the Herpes OsHV-1 μvar virus which causes an immunosuppression of oysters that are then colonized by various opportunistic pathogenic bacteria including vibrios inducing the death of the animal. V. tasmaniensis LGP32 is a facultative intracellular pathogen of oyster hemocytes that resists phagocytosis and destroys hemocytes using different virulence factors. We have therefore undertaken to study the interactions between marine amoebae of the oyster environment and the vibrios in order to verify if some mechanisms of virulence could also play a role in this type of interactions. By performing field sampling, we demonstrated that the interaction between vibrios and amoebae is ecologically realistic and observed a low diversity of heterotrophic protists near the oyster tables of the Thau Lagoon compared to other less anthropogenic environments. Functional studies between LGP32 and the amoeba Vannella sp. AP1411 showed that LGP32 is able to resist amoeba predation involving certain virulence factors such as Vsm metalloprotease and CopA P-ATPase copper efflux pump which are also involved in the interaction of LGP32 with oysters. In contrast, other virulence factors implicated in the oyster are not involved in amoeba-predation resistance indicating that some factors are involved in interactions with various hosts while others would be involved in more specific interactions
Oyanedel, Trigo Daniel. "Bases moléculaires et cellulaires des interactions Vibrios Crassostrea gigas en contexte sain et pathologique." Thesis, Montpellier, 2020. http://www.theses.fr/2020MONTG032.
Full textBacteria of the genus Vibrio are ubiquitous in aquatic environments. They adopt free and associated lifestyles. They establish mutualistic, commensal and parasitic symbioses with numerous metazoa. In the healthy Crassostrea gigas oyster, an abundant and diverse microbiota that includes many Vibrio is maintained under immune homeostasis. However, under the influence of biotic or abiotic stressors a dysbiosis is created favoring the proliferation of opportunistic Vibrio species, which can induce the death of oysters. This occurs during the Pacific Oyster Mortality Syndrome (POMS), which is caused by an immunosuppressive virus, OsHV-1 µvar. We have here characterized the Vibrio / C. gigas interactions in health and disease. We show that in populations of V. splendidus associated with healthy oysters, virulence and colonization capacity can be constrained by the selection of O-antigen structures that are more easily recognized by the host immune system but which confer resistance to grazing by marine amoebae. This trade-off between the ability to colonize its host and environmental persistence is likely the cause of the great structural diversity observed for the O-antigen in this species. In a pathological context, we have shown that the species associated with the oyster are for the most part cytotoxic for the immune cells of their host, regardless of the environment considered (Atlantic, Mediterranean). This cytotoxicity is a key determinant of the escape from the oyster's powerful cellular defenses and determines the infectious success. We observed that the molecular bases of cytotoxicity are specific to each Vibrio species studied. Finally, beyond opportunistic pathogens that use cytotoxicity (V. tasmaniensis, V. crassostreae, V. splendidus, V. harveyi), we have identified simple opportunists, such as V. rotiferianus, which not only benefit from the immunosuppressive activity of other pathogens but also adopt strategies of non-cooperative acquisition of public goods, such as siderophores produced by the microbial community hosted by their host
Silveira, Ana Cristina Gomes. "Identification of Non-Coding RNAS in Marine Vibrios." Laboratório Nacional de Computação Científica, 2010. http://www.lncc.br/tdmc/tde_busca/arquivo.php?codArquivo=212.
Full textA descoberta de RNA não-codificante (ncRNA) tem focado principalmente nos genomas de eucariontes e de bactérias patogênicas. Em vibrios, o que se conhece até o momento sobre ncRNAs envolve V. cholerae N16961 e V. campbellii ATCC BAA-1116. Neste estudo, são identificados genes candidatos de ncRNAs no genoma de V. campbellii ATCC BAA-1116, V. alginolyticus 40B, V. communis 1DA3 e V. mimicus VM573. V. alginolyticus 40B e V. campbellii ATCC BAA-1116 são abundantes em corais brasileiros, enquanto que V. mimicus VM573 é uma linhagem toxigênica (CT e TCP positiva) atípica desta espécie. Para identificar os ncRNAs através de análise in silico foram utilizadas ferramentas já disponíveis (Infernal e a base de dados Rfam) e programas em Perl desenvolvidos no presente trabalho. A ferramenta Infernal e a base de dados Rfam são baseados em modelo de covariância (CM), um caso especial de gramáticas estocásticas livres de contexto (SCFG). Foram identificados até 38 ncRNAs por espécie, os quais foram classificados em sete classes de acordo com sua função regulatória e /ou estrutural (riboswitches, moduladores da atividade de proteínas, RNAs antisenso de ação trans, RNAs antisenso de ação cis, ribonucleoproteinas, regulação por término de transcrição e classificação desconhecida). O grupo mais abundante foi o riboswitch, enquanto que o grupo menos abundante foi o ribonucleoproteina. Este trabalho demonstrou que os ncRNAs apresentam uma ampla diversidade de classes funcionais, estando possivelmente associados com a regulação de diferentes processos celulares em vibrio, incluindo a regulação da patogenicidade.
Matte, Glavur Rogerio. "Isolamento de vibrios potencialmente patogênicos em moluscos bivalves." Universidade de São Paulo, 1994. http://www.teses.usp.br/teses/disponiveis/6/6134/tde-14072016-152410/.
Full textIn this work, 26 oysters samples (Crassostrea gigas), found in the market of São Paulo city and some coastal areas of São Paulo State, and 36 mussels samples (Perna perna), that were collected monthly in 3 coastal areas of Ubatuba city - SP., were analyzed for the potential patogenic vibrios occurrence. Samples were enriched in alcalin peptone water with (1 per cent ) and without sodium cloride and GSTB. Isolation was performed on TCBS agar. suspect sacharosis positive and negative colonies, resembling vibrio species, were presumptively identified on Kligler iron agar, and confirmed by complementary biochemical tests. Some of this potential patogenic vibrios were submitted to suckling mouse assay and rabbit ileal loop assay. Potential patogenic vibrios isolated from oyster samples were: V. alginolyticus (81 per cent ), V. parahaemolyticus (77 per cent ), V. cholerae non 0:1 (31 per cent ), V. fluvialis (27 per cent ) I V. furnissii (19 per cent ), V. mimicus (12 per cent ) and V. vulnificus (12 per cent ) and from mussels samples were: V. a.1ginolyticus (97 per cent ), V. parabaemolyticus (75 per cent ), V. fluvialis (47 per cent ), V. vulnificus (11 per cent ), V. cholerae non 0:1 (6 per cent ), V. furnissii (6 per cent ) and V. mimicus (6 per cent ). It was found 6,9 per cent of samples between 0,25 and 0,49 ml/cm of fluid accumulation in ileal loop assay, 15,6 per cent between 0,5 and 0,99 ml/cm and 15,1 per cent was equal or higher than 1 ml/cm. Among the samples assayed for suckling mouse 26,6 per cent were positive. These results confirm the high potential of these microrganisms to induce gastroenteritis. Seasonal variation as well as correlation between the potential patogenic vibrios isolated and the fecal contamination indicators were not found, confirming that the presence of such microrganisms occurs autochthonously and that the climate conditions were favourable to these species survival during the whole year. with the results of this work and considering that oyster and mussels are usually ingested raw or insufficiently cooked, the conclusion is that the ingestion of such mollusks presents a certain degree of risk for the consumer\'s health.
Silveira, Ana Cristina Gomes. "Identificação de RNAs não-codificantes em vibrios marinhos." Laboratório Nacional de Computação Científica, 2010. https://tede.lncc.br/handle/tede/13.
Full textCoordenacao de Aperfeicoamento de Pessoal de Nivel Superior
The discovery of the non-coding RNA (ncRNA) has been primarily focused on the genomes of eukaryotes and pathogenic bacteria. In vibrios, all that is known up to now regarding ncRNAs involves V. cholerae N16961 e V. campbellii ATCC BAA-1116. In this study, ncRNA candidate genes were identified in the genomes of V. campbellii ATCC BAA-1116, V. alginolyticus 40B, V. communis 1DA3 e V. mimicus VM573. V. alginolyticus 40B and V. campbellii ATCC BAA-1116 are abundant in brazilian corals, whereas V. mimicus VM573 is a toxic strain (carrying the Vibrio pathogenicity island) atypical to this species. In order to identify the ncRNAs in silico, the tools Infernal and Rfam database were used. Perl programs were developed in the present work. The Infernal tool and the Rfam database are based on the Covariance Model (CM), a special case of Stochastic Context Free Grammars (SCFG). Up to 38 ncRNAs were identified per species. They were classified into seven classes according to their regulatory function and/or structural (1. riboswitches, 2. modulators of protein activity, 3. RNA's antisensus of trans action, 4. RNA's antisensus of cis action, 5. ribonucleoproteins, 6. regulation by transcription termination and 7. unknown classification). The most abundant group was the riboswitch, whereas the less abundant group was the ribonucleoprotein. This work demonstrated that the ncRNAs show a great diversity in functional classes, possibly associated with the regulation of different cellular processes in vibrios, including regulation of pathogenicity.
A descoberta de RNA não-codificante (ncRNA) tem focado principalmente nos genomas de eucariontes e de bactérias patogênicas. Em vibrios, o que se conhece até o momento sobre ncRNAs envolve V. cholerae N16961 e V. campbellii ATCC BAA-1116. Neste estudo, são identificados genes candidatos de ncRNAs no genoma de V. campbellii ATCC BAA-1116, V. alginolyticus 40B, V. communis 1DA3 e V. mimicus VM573. V. alginolyticus 40B e V. campbellii ATCC BAA-1116 são abundantes em corais brasileiros, enquanto que V. mimicus VM573 é uma linhagem toxigênica (CT e TCP positiva) atípica desta espécie. Para identificar os ncRNAs através de análise in silico foram utilizadas ferramentas já disponíveis (Infernal e a base de dados Rfam) e programas em Perl desenvolvidos no presente trabalho. A ferramenta Infernal e a base de dados Rfam são baseados em modelo de covariância (CM), um caso especial de gramáticas estocásticas livres de contexto (SCFG). Foram identificados até 38 ncRNAs por espécie, os quais foram classificados em sete classes de acordo com sua função regulatória e /ou estrutural (riboswitches, moduladores da atividade de proteínas, RNAs antisenso de ação trans, RNAs antisenso de ação cis, ribonucleoproteinas, regulação por término de transcrição e classificação desconhecida). O grupo mais abundante foi o riboswitch, enquanto que o grupo menos abundante foi o ribonucleoproteina. Este trabalho demonstrou que os ncRNAs apresentam uma ampla diversidade de classes funcionais, estando possivelmente associados com a regulação de diferentes processos celulares em vibrio, incluindo a regulação da patogenicidade.
Chen, Desheng, and 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.
Full textTASSISTRO, GIOVANNI. "Vibrios involved in Crassostrea gigas infections during mass mortality episodes." Doctoral thesis, Università degli studi di Genova, 2019. http://hdl.handle.net/11567/944830.
Full textCollin, Betty. "Characterization and persistence of potential human pathogenic vibrios in aquatic environments." Doctoral thesis, Högskolan Kristianstad, Sektionen för lärande och miljö, 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:hkr:diva-9789.
Full textAugusto, Dora Susana Castro Rodrigues. "Teores de vibrios halófilos patogénicos humanos em ostras, por NMP-PCR." Master's thesis, Universidade de Aveiro, 2007. http://hdl.handle.net/10773/737.
Full textO presente estudo foi levado a cabo com o objectivo de determinar a ocorrência e os níveis de Vibrio vulnificus, Vibrio parahaemolyticus (total e potencialmente patogénico) em ostras naturalmente contaminadas, usando dois métodos diferentes de Número Mais Provável (NMP) em conjugação com a técnica de reacção em cadeia da polimerase (PCR) de modo a seleccionar o mais apropriado para análise de rotina. As ostras foram adquiridas em lojas e supermercados locais. Os valores de V. vulnificus (portador do gene que codifica a hemolisina/citolisina da bactéria - vvhA), V. parahaemolyticus total (portador do gene específico da espécie – toxR) e V. parahaemolyticus potencialmente patogénico (portador dos genes que codificam as hemolisinas directa termoestável – tdh e directa termoestável relacionada – trh) foram determinados usando dois métodos de NMP-PCR: (1) enriquecimento em água peptonada alcalina (APW) seguido de PCR (APW-PCR); e (2) enriquecimento em APW e isolamento em agar de tiossulfato citrato bílis sacarose (TCBS) seguido de confirmação das estirpes por PCR (TCBS-PCR). Foi detectado V. vulnificus em quatro amostras de ostras pelo método APWPCR e em três amostras pelo método TCBS-PCR, mas nunca nas mesmas amostras. Foi possível encontrar V. parahaemolyticus em 14 amostras pelo método APW-PCR e em 13 amostras pelo método TCBS-PCR. Quanto aos factores de virulência, foi possível detectar o gene tdh em uma amostra somente pelo método APW-PCR; o gene trh foi detectado em cinco amostras por ambos os métodos, mas nem sempre na mesma amostra. O método APW-PCR demonstrou ser o mais adequado para detectar a presença de V. parahaemolyticus total em ostras, uma vez que gerou maior número de amostras positivas e detectou teores mais elevados, no entanto, recomenda-se o recurso a ambos os métodos para a detecção dos factores de virulência do V. parahaemolyticus e para a detecção de V. vulnificus. ABSTRACT: The present study was carried out to determine the occurrence and levels of Vibrio vulnificus and total and potentially pathogenic Vibrio parahaemolyticus bacteria in naturally contaminated oysters, using two Most Probable Number – Polymerase Chain Reaction (MPN-PCR) different methods in order to select the most appropriate for routine analysis. Oysters were collected from local stores and supermarkets. V. vulnificus (carrying the hemolysin/ cytolysin vvhA gene), total V. parahaemolyticus (carrying the species-specific toxR gene) and potentially pathogenic (carrying the thermostable direct hemolysin - tdh and TDH-related hemolysin - trh genes) V. parahaemolyticus were enumerated by two MPN-PCR methods: (1) Alkaline Peptone Water (APW) enrichment followed by PCR (APW-PCR); and (2) APW enrichment plus isolation on Thiosulfate Citrate Bile Sucrose (TCBS) agar followed by PCR strain confirmation (TCBS-PCR). V. vulnificus was found in four oyster samples by the APW-PCR method and in three by the TCBS-PCR method, but never in the same samples. V. parahaemolyticus was found in 14 oyster samples by the APW-PCR method and in 13 by the TCBS-PCR method. Concerning virulence factors, tdh positive organisms were only detected by the APW-PCR method in one sample; trh positive organisms were found in five oyster samples by both methods though not always in the same sample. The APW-PCR method has shown to be more adequate for the detection of total V. parahaemolyticus in oysters, since it yielded a larger number of positive samples, however, for detection of V. parahaemolyticus virulence factors and V. vulnificus, both methods should be used.
Ostrander, Vicki C. "Survival of Vibro vulnificus and other Vibrios in raw oysters (Crassostrea virginica) during processing in Virginia and cold storage." Thesis, This resource online, 1996. http://scholar.lib.vt.edu/theses/available/etd-11012008-063712/.
Full textDaccord, Aurélie. "Étude de la mobilité d'une nouvelle classe d'îlots génomiques chez les vibrios." Thèse, Université de Sherbrooke, 2013. http://hdl.handle.net/11143/6543.
Full textHu, Xiaopei. "Application of Alternative Technologies to Eliminate Vibrios spp. in Raw Oysters." Diss., Virginia Tech, 2004. http://hdl.handle.net/10919/25940.
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James, Adèle. "Ecology, evolution and virulence of environmental vibrios." Electronic Thesis or Diss., Sorbonne université, 2018. https://accesdistant.sorbonne-universite.fr/login?url=https://theses-intra.sorbonne-universite.fr/2018SORUS477.pdf.
Full textGlobal change, including anthropogenic activities, have resulted in an increase in the incidence of Vibrio-associated illnesses. These diseases not only affect humans but also marine animals. Despite strong ecological and economic consequences, little is known about population structure and virulence mechanisms of vibrios in the environment. To better understand and manage those diseases, we explored the ecology, the evolution and the virulence of these infectious agents. First, we found that some environmental strains were virulent towards oyster and we identified original virulence mechanisms related to their ecology and evolution. In France, oyster-farms are facing massive mortality events associated with the presence of a virus and bacteria of the genus Vibrio. We showed that the virus appears neither essential nor sufficient to cause high mortality rates contrary to the vibrios that play a major role. Juvenile diseased oysters were always co-infected by several populations, but only one, Vibrio crassostreae, was detected systematically and in abundance. Its virulence is dependent on a type VI secretion system that is carried by a conjugative plasmid. Our results suggest that V. crassostreae first differentiated into a low-virulent oyster colonizer and turned into a pathogen after acquisition of the virulence plasmid. The narrow distribution of the plasmid suggests that it has been selected by high density farming areas. Finally, we showed that the plasmid transfer or selection was enhanced in oysters, which suggests that oysters represent a niche for horizontal gene transfer. Overall, this work can lead to the development of diagnostic tools and epidemiological monitoring of pathogenic vibrios
Bienlien, Lydia M. "Influence of Perkinsus Marinus Infection and Oyster Health on Levels of Human-Pathogenic Vibrios in Oysters." W&M ScholarWorks, 2016. https://scholarworks.wm.edu/etd/1477068161.
Full textRubio, Tristan. "Diversité des mécanismes d’interactions des vibrios du clade Splendidus et de leur hôte, l'huître creuse Crassostrea gigas." Thesis, Montpellier, 2017. http://www.theses.fr/2017MONTT098/document.
Full textIn the Splendidus clade, Vibrio tasmaniensis and Vibrio crassostreae are two populations of virulent vibrio for oysters that are associated to "juvenile oyster mortality syndrome". Here we were interested in the diversity of interaction mechanisms between the vibrios and their host, the oyster Crassostrea gigas. First, we investigated the pathogenesis process of the strain V. tasmaniensis LGP32 and showed that it exerts a cytotoxic activity against oyster immune cells, the hemocytes, which depend on its entry into the cells through phagocytosis. Transcriptomic analysis of LGP32 response during intracellular stage revealed a crucial role for antioxydant systems and copper efflux in intraphagosomal survival of the bacteria. From a functional point of view, we showed that this virulence mechanisms of LPG32 play a major role in pathogenesis in vivo. Second, we realized a comparative study of the interaction mechanisms between representative strains of the two populations V. tasmaniensis and V. crassostreae with the oyster. Virulent strains from both populations were cytotoxic for hemocytes but this cytotoxicity was independant of phagocytosis in the case of V. crassostreae, in contrary to V. tasmaniensis. Transcriptomic analysis of the oyster responses during infection showed that virulent strains of both populations repressed the expression of genes involved in antibacterial responses. However, some pecific responses were also identified for each virulent strain, highlighting some diversity of interactions. In vivo, virulent strains were able to colonize oyster tissues, in contrary to non-virulent strains, which were controlled by hemocytes. Our work show, although a certain degree of diversity and specificity exist in the interactions between different vibrios of the Splendidus clade and oysters, both virulent populations are cytotoxic for immune cells, and this process is essential for their infectious success. Thus, the capacity to overcome the hemocyte defenses is a conserved phenotype between distinct virulent populations of vibrios from the Splendidus clade. Hence, it would be of particular interest to determine the evolutionary processes that drove the emergence of common virulence traits in distinct populations of pathogens
Romero, Ormazábal Jaime. "Microflora en ostras chilenas y su incidencia en la colonización por vibrios patógenos y en la descomposición post cosecha." Tesis, Universidad de Chile, 2002. http://www.repositorio.uchile.cl/handle/2250/106698.
Full textLavezzo, Lígia Carolina. "Caracterização das especies de vibrios isoladas em amostras de água do mar, plâncton e bivalves da zona litorânea do Estado de São Paulo." Universidade de São Paulo, 2015. http://www.teses.usp.br/teses/disponiveis/87/87131/tde-18112015-192329/.
Full textThe aim of this study was to characterize at the molecular level Vibrio species isolated from seawater, plankton, bivalves samples from Canal de São Sebastião (n=78), Baixada Santista (n=37) and Ubatuba (n=17), to analyze antimicrobial susceptibility and the major virulence-associated genes. The results showed ciprofloxacin, meropenem, nalidixic acid sensitivity, ampicillin, and cephalothin resistance, and a significant percentage of multidrug resistance (Ubatuba: 64.7%; Baixada Santista: 48.6%; Canal de São Sebastião: 43%). Four seawater isolates were found positive for the stn/sto virulence gene. MLSA allowed the identification of V.alginolyticus, V.fluvialis, V.campbellii, V.harveyi in Ubatuba; V.fluvialis, V.alginolyticus, V.campbellii, V.rotiferianus, V.harveyi, V.diabolicus, V.atypicus, V.coralliilyticus, V.maritimus, V.parahaemolyticus and V.tubiashii in Canal de São Sebastião, and V.alginolyticus, V.parahaemolyticus, V.rotiferianus, V.campbellii, V.harveyi, V.communis, V.maritimus, V.fluvialis, V.fortis, V.natriegens, and V.navarrensis in Baixada Santista.
Badela, Andiswa Unathi. "Prevalence and pathogenicity of vibrios in treated final effluents of selected wastewater treatment plants in the Amathole District Municipality of Eastern Cape Province of South Africa." Thesis, University of Fort Hare, 2014. http://hdl.handle.net/10353/d1019774.
Full textPretto, 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.
Full textVibrio 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.
Piel, Damien. "Évolution de la virulence de V. crassostreae en lien avec l’huître en tant qu’hôte et les phages en tant que prédateurs." Electronic Thesis or Diss., Sorbonne université, 2019. https://accesdistant.sorbonne-universite.fr/login?url=https://theses-intra.sorbonne-universite.fr/2019SORUS462.pdf.
Full textUnderstanding the ecological and evolutionary dynamics of infectious agents is important for diagnosing, predicting and preventing diseases in farmed and wild species. This project was aimed at studying the evolution of V. crassostreae virulence in relation to the oyster as a host and to the phages as predators. We identified the molecular mechanisms leading to the adaptation of vibrios to oysters. We demonstrated the emergence of virulent strains of V. crassostreae in the area impacted by the juvenile oyster mortality syndrome. The emergence of more virulent V. crassostreae strains is linked to the acquisition of a plasmid encoding a type 6 secretion system responsible for lethal activity towards oyster hemocytes. This project also provides knowledge on the interactions between V. crassostreae and phages such as the identification of the predation unit as well as potential mechanisms involved in strain resistance and phage virulence. This represents a first step towards the development of prophylactic ecofriendly strategies
Zhao, Weining [Verfasser], Stephan [Akademischer Betreuer] [Gutachter] Sieber, and Tobias [Gutachter] Gulder. "Investigation of Fimbrolide and Beta-Lactone Targets Related to the Inhibition of Quorum Sensing-Regulated Bioluminescence in Vibrios / Weining Zhao ; Gutachter: Tobias Gulder, Stephan Sieber ; Betreuer: Stephan Sieber." München : Universitätsbibliothek der TU München, 2016. http://d-nb.info/1117796701/34.
Full textMelo, Ligia Maria Rodrigues de. "Resistotipagem e transfer?ncia gen?tica de plasm?dios de resist?ncia entre coliformes e vibrios potencialmente patog?nicos para o homem isolados de camar?o (litopenaeus vannamei) comercializado em Natal-Rio Grande do Norte." Universidade Federal do Rio Grande do Norte, 2012. http://repositorio.ufrn.br:8080/jspui/handle/123456789/13261.
Full textCinquenta amostras de camar?o fresco e refrigerado (Litopenaeus vannamei) foram coletadas em diferentes pontos de comercializa??o na cidade de Natal RN. As amostras foram maceradas em um gral est?ril e 25 gramas semeadas em 225mL de APA contendo 1% de NaCl e 25g em 225mL de CL incubadas a 35?C - 24 horas. O crescimento em APA foi semeado em placas de ?gar TCBS, incubadas a 35?C-24h para isolamento de Vibrio e Aeromonas. O crescimento do CL foi semeado em Agar EAM, para isolamento de coliformes. Dos 102 isolados, 91 (89,2%) pertenciam ao g?nero Vibrio e 11 (10,8%) ao g?nero Aeromonas, com predomin?ncia de V. cholerae n?o O1/n?o O139, V. alginolyticus, V. carchariae e V. parahaemolyticus K- e A. veronii biogrupo sobria , A. jandaei, A. schubertii, A. veronii biogrupo veronii e A. hydrophila. A menor efici?ncia entre os antimicrobianos foi da AMP (57,8% de resist?ncia) seguida da AMK (29,4%) e TCY (21,6%). As 39 cepas de Vibrio e Aeromonas multirresistentes se distribu?ram em 10 perfis distintos, sendo que um revelou cinco marcos (AMP, CHL, NIT, SXT e TCY) em um isolado de V. carchariae de camar?o, adquirido em supermercados. O ?ndice MAR, nas 39 cepas variou de 0,28 a 0,42, sugerindo que s?o de risco na transfer?ncia e difus?o da resist?ncia na cadeia alimentar. Ap?s a cura plasmidial pelo tratamento com AO de 24 cepas multirresistentes e com resist?ncia intermedi?ria de v?brio e aeromonas escolhidas aleatoriamente, 13 perderam totalmente a resist?ncia e 7 perderam parcialmente, sendo que o maior percentual de perda da resist?ncia ocorreu nas cepas de V. cholerae n?o O1 e n?o O139 (6 cepas), se concentrando nos marcos de resist?ncia a AMP (13), AMK (11), TCY(8) e CIP(3). Os resultados da conjuga??o realizada entre amostras de Vibrio xvi curadas e a E. coli K12C600 demonstraram que 78,5% das culturas de Vibrio testadas revelaram capacidade de transfer?ncia para o gene que confere resist?ncia a AMP e 28,5% para a TCY. Dos coliformes, E. coli foi a mais frequente, seguida de Citrobacter spp, isoladas em 40,3% e 27,5% das amostras respectivamente. AMP foi o antimicrobiano menos eficaz, seguido de TCY. As 11 cepas multirresistentes se distribu?ram em 9 perfis distintos, um deles constitu?do de cinco marcos (AMP, NIT, TCY, CHL, SXT), albergados em uma cepa de Klebsiella spp, oriunda de camar?o adquirido em supermercado, similar ao resultado obtido em V. carchariae. Conclui-se que, os camar?es marinhos frescos e refrigerados, comercializados em Natal-RN evidenciaram contamina??o com coliformes, v?brios e aeromonas multirresistentes a antimicrobianos comumente utilizados na terapia m?dica e veterin?ria, e que, possivelmente, a transfer?ncia de genes de resist?ncia entre bact?rias se constitui um s?rio problema de sa?de p?blica
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.
Full textAbalone 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
Cardinaud, Marion. "Étude multifactorielle de la vibriose chez l'ormeau européen Haliotis tuberculata : bases génomiques et physiologiques de la survie aux mortalités estivales chez l'ormeau européen Haliotis tuberculata." Thesis, Brest, 2013. http://www.theses.fr/2013BRES0062/document.
Full textFor fifteen years, summer mortalities have been observed in wild and farmed populations of European abalone, Haliotis tuberculata, along the north French coast. These mortalities are attributed to the bacterial species Vibrio harveyi and occur in sexually mature animals, when the seawater temperature exceeds 17°C.A multifactorial approach to the study of this host-parasite interaction was done during this thesis, in order to specify the intrinsic abalone conditions in vibriosis mortalities, the infectious cycle of V. harveyi in European abalone and the role of temperature in the fulfillment of this infectious cycle, and finally the physiological response of abalone, at cellular and molecular level, when exposed to V. harveyi.The main results showed a differential gene expression between resistant and susceptible abalone during exposure to V. harveyi, indicating the importance of the physiological status of the host, in survival to vibriosis. This hypothesis is supplemented by the susceptibility of sexually immature abalone at 19°C to this disease, usually resistant, and exposed to manipulation stressor. Moreover, the study of the portal of entry and the dynamics of infection by V. harveyi in European abalone revealed a particular tropism of this vibrio pathogen for gill tissues, in the earlier hours of contact, and its invasion into the circulatory system from the first 24 hours of contact. The study of the response of abalone hemocyte and gill metabolism, at the cellular and molecular level, in the earlier hours of contact, shows 1/ a genesis of oxidative stress in gills of susceptible abalone, and 2/ an alteration of hemocyte functions, which may constitute one of the major strategies of virulence in V. harveyi
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.
Full textMost 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
DOURADO, Joanna. "Vibriose em camarões marinhos ( Litopenaeus vannamei, Boone 1931) cultivados no litoral de Pernambuco, Brasil." Universidade Federal Rural de Pernambuco, 2009. http://www.tede2.ufrpe.br:8080/tede2/handle/tede2/5686.
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Shrimp farming all over the world has been affected in the last years by many diseases, that have contributed to the development indexes decline in the production of farmed marine shrimp. On top of the losses due to diseases, it's important to mention that some of the vibrio species are zoonotic agents, meaning they can also cause diseases in humans. Given the importance of bacteria of the genus Vibrio to shrimp farming and public health, the aim of this study was to evaluate marine shrimp, correlate the clinical findings with the presence of the vibrio bacteria and identify the isolated species in the water of the ponds of cultivated marine shrimp in Pernambuco. The samples were collected from four coastal farms and the laboratory analysis consisted of the research and identification of the vibrio bacteria in the hepatopancreas and in the water of the tanks, and identification of any alteration by examination of fresh samples. Thiosulphate citrate bile salt agar (TCBS) was used as the culture media and the selected colonies were later biochemically tested. Four hundred and eighty shrimps were analyzed, of hose 424 (88.33%) showed to have vibrio and one or more alterations. There were identified a total of 903 alterations, the most frequent of muscle tissue (329; 36.43%) and the least frequent of the hepatopancreas tubules (121; 13.40%). When analizing the growth cycle, it was observed the largest number of alterations (503; 55.7%) in the dry season. Taking into account the weight of the shrimps, it was observed 540 (59.8%) alterations when the average weight was 8g. Out of all the analyzed animals, 314 (65.42%) showed to have vibrio, being 38 samples from the ponds water and 605 shrimp isolated. The most abundant species was V. mediterranei, (21.31%), considered an environmental species non pathogenic to shrimp, and the least abundant species were V. campbellii, V. rotiferanus, V. shiloni, V. splendidus, V. tapetis and V. wodanis (0.16 %). A dependency between the alterations found on the exam and the presence of the vibrio was noticed, showing that the aforementioned exam, combined to microbiological analyzes, is an important tool that should be used when monitoring the farms. It was also noticed a great variety of pathogenic and non pathogenic species of vibrio in the studied samples. Such microorganisms could, eventually, be related to shrimp and human infections, which could represent a risk for shrimp farming and public health respectively.
A carcinicultura mundial tem enfrentado nos últimos anos vários impactos causados por enfermidades, que contribuíram para a queda dos índices de desenvolvimento na produção de camarão marinho cultivado. Além das perdas causadas devido às enfermidades, ressalta-se que algumas espécies de víbrio são agentes zoonóticos, ou seja, podem causar doenças também em humanos. Dada a importância das bactérias do gênero Vibrio para a carcinicultura e saúde pública, objetivou-se avaliar camarões marinhos, associar os achados clínicos com a presença de bactérias do gênero Vibrio e identificar as espécies isoladas da água dos viveiros e de camarões marinhos (Litopenaeus vannamei) cultivados no litoral do estado de Pernambuco. As amostras foram coletadas em quatro carciniculturas do litoral e as análises laboratoriais compreenderam pesquisa e identificação de bactérias do gênero Víbrio no hepatopâncreas e na água dos viveiros, e identificação de alterações através do exame a fresco. Para o isolamento das espécies foi utilizado o meio de cultivo Ágar Tiossulfato Citrato Sais de Bile Sacarose (TCBS) e as colônias selecionadas foram posteriormente submetidas a provas bioquímicas. Foram analisados no total 480 camarões, destes 424 (88,33%) apresentaram um ou mais tipos de alteração. Foi identificado um total de 903 alterações, sendo a mais freqüente a da musculatura (329; 36,43%) e a menos freqüente a alteração dos túbulos do hepatopâncreas (121; 13,40%). Com relação ao ciclo de cultivo, foi observado o maior número de alterações (503; 55,7%) no período de estio. Levando-se em consideração a média de peso dos camarões verificou-se 540 (59,8%) alterações quando os mesmos estavam com peso médio de 8 g. Do total de animais analisados 314 (65,42%) apresentavam vibrio e uma ou mais alteração no exame a fresco. Foi obtido um total de 643 isolados de Vibrio, sendo 38 de amostras de água dos viveiros e 605 isolados de camarão. A espécie mais abundante foi V. mediterranei (21,31%), considerada espécie ambiental e não patogênica para o camarão, e as espécies de menor predominância foram V. campbellii, V. rotiferianus, V. shiloni, V. splendidus, V. tapetis e V. wodanis (0,16%). Foi verificada uma dependência entre as alterações encontradas no exame a fresco e a presença de vibrio, concluindo-se que o referido exame, associado à análise microbiológica é uma importante ferramenta que deve ser utilizada no monitoramento da saúde dos animais. Verificou-se também uma ampla variedade de espécies patogênicas e não patogênicas de víbrio nas amostras estudadas, que podem eventualmente estar relacionados a infecções nos camarões e nos humanos, representando um risco para a carcinicultura e para a saúde pública respectivamente.
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.
Full textVibrio 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
Abi, Khalil Celina. "Effets apoptotiques du dinoflagellé Alexandrium catenella et de ses toxines sur les cellules immunitaires de l'huître creuse Crassostrea gigas : implications dans la susceptibilité de l'huître aux vibrioses." Thesis, Montpellier, 2016. http://www.theses.fr/2016MONTT108.
Full textIn France, oyster sites in the Mediterranean Sea are regularly confronted to high mortalities of Crassostrea gigas juveniles and to recurrent blooms of the dinoflagellate producer of Paralytic Shellfish Toxins (PSTs), Alexandrium catenella. Among the pathogens associated to these mortalities, we found Vibrio strains belonging to Splendidus clade. We here focus on the interactions between A. catenella and the oyster C. gigas challenged with pathogenic vibrios. In the first part of this work, we have shown that, in vivo, A. catenella increased the susceptibility of the oyster C. gigas to the pathogen Vibrio tasmaniensis LGP32. In situ, we also established the coincidence between oyster mortality in 2014 and the presence of PSTs in their tissues. In the second part of this work, we studied the interactions between the PSTs produced by A. catenella and oyster immune cells, the hemocytes. An important result of this thesis was that saxitoxin, a toxin produced by A. catenella, binds to granular structures in the cytoplasm of C. gigas hemocytes and induces their caspase-dependent cell death. This death is independent of the production of reactive oxygen species. We also demonstrated that the major toxin of A. catenella cells, the gonyautoxin 5, is the most toxic on C. gigas hemocytes. Among affected hemocyte populations, the hyalinocytes are very sensitive to this toxic stress. As hemocytes are oyster immunocompetent cells and therefore play the central role in the defense against infections, we can presume that their cell death induced by the PSTs negatively affects the defense of bivalve mollusks and explains the increased susceptibility of oysters to the infection by Vibrio tasmaniensis LGP32 when exposed to A. catenella
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.
Full textNaim, Sidrotun. "Growth, Vibriosis, and Streptococcosis Management in Shrimp-Tilapia Polyculture Systems, and the Role of Quorum Sensing Gene cqsS in Vibrio harveyi Virulence." Diss., The University of Arizona, 2012. http://hdl.handle.net/10150/268595.
Full textLambert, Christophe. "ETUDE DES INFECTIONS A VIBRIONACEAE CHEZ LES MOLLUSQUES BIVALVES, A PARTIR D'UN MODELE LARVES DE PECTEN MAXIMUS." Phd thesis, Université de Bretagne occidentale - Brest, 1998. http://tel.archives-ouvertes.fr/tel-00525764.
Full textCroxatto, Antony. "VanT, a central regulator of quorum sensing signalling in Vibrio anguillarum." Doctoral thesis, Umeå : Umeå University, Department of Molecular Biology, 2006. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-702.
Full textAltinoglu, Ipek. "Organization of Bacterial Cell Pole." Thesis, Université Paris-Saclay (ComUE), 2018. http://www.theses.fr/2018SACLS367/document.
Full textIn rod shaped bacteria, cell poles serve as important subcellular domains involved in several cellular processes including motility, chemotaxis, protein secretion, antibiotic resistance, and chromosome segregation. In the cholera pathogen Vibrio cholerae, vibrioid rod shape and single polarized flagellum involve in the virulence. Polar landmark protein HubP was shown to interact with multiple ATPases, such as ParA1 (chromosome segregation), ParC (polar localization of chemotaxis apparatus), and FlhG (flagella biosynthesis), thus organizing the polar identity of V. cholerae by tethering proteins to cell pole. However, the exact molecular mechanisms are yet to be elucidated. In this thesis, I tackled to unveil comprehensive view of the cell pole organization which implies the orchestration of different cellular functions, by identifying further interaction partners of HubP as well as drawing conceivable picture of the cell pole by super-resolution photoactivated localization microscopy. To identify new interaction partners of HubP, I used minicells in which cell poles were enriched as they derived from cell division near the cell pole. Difference in protein composition between HubP+ and HubP- minicells were examined by isobaric tags for relative and absolute quantitation. Among ~800 proteins identified, ~80 proteins were considered to be enriched in HubP+ minicells including many expected proteins (FlhG, ParC and downstream chemotaxis proteins). I chose 14 proteins to investigate their subcellular localization with fluorescent microscopy. In conclusion, I discovered 4 proteins that showed polar localization in a HubP-dependent manner. These proteins are VbrX, VbrY, and 2 hypothetical proteins MotV and MotW. ∆motV and ∆motW showed significant defect in a diameter of travel in soft agar plate that suggesting the possible involvement in chemotaxis and/or motility. Whereas electron microscopy showed that both mutants possess intact monotrichous flagellum, video-tracking revealed that the two mutants showed rather distinct defects during swimming: MotV is rather turning mutant while MotW is a speed mutant. Fluorescent microscopy experiments indicated that MotV, MotW and HubP showed distinct polar dynamics over cell cycle. For fine-scale observation of the cell pole by PALM, it was appreciated that novel tools for high-throughput analysis was demanded. Since brightfield images are not sufficient to have accurate contours of small and low contrast bacterial cells, I developed new labeling technique with photoactivatable fluorescent proteins for precise outlining at either inner membrane or periplasm. Furthermore, we created Matlab-based software called Vibio which integrates cell outline and the list of molecules obtained by super-resolution microscopy. High-throughput capability of the software enabled to analyze distribution of detected molecules from single cell to whole bunch of cells in a manner that cells are oriented by cell curvature. These allowed me to discover that HubP is mostly lopsided at the convex side of the cell pole, while its partners mostly located middle of the pole. Altogether, I successfully unveiled 4 novel interaction partners of HubP. I revealed of the function of hypothetical proteins that are involved in cell motility. I developed new labeling technique for precise polar localization that works well for PALM image analysis in Vibio. Therefore, I observed precise polar localization of HubP and other polar proteins
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.
Full textLeung, 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.
Full textLimthammahisorn, 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.
Full textAlvarez, Julia D. "Studies on Venezuelan fish and shrimp associated bacteria." Thesis, Heriot-Watt University, 1998. http://hdl.handle.net/10399/619.
Full textLima, 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.
Full textThis 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.
Oliveira, Karina Zupo de. "Construção de filogenias baseadas em genomas completos." [s.n.], 2010. http://repositorio.unicamp.br/jspui/handle/REPOSIP/275803.
Full textDissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Computação
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Resumo: Contexto: A classificação de espécies começou sendo determinada pelas características fenotípicas dos organismos. Logo que o DNA foi descoberto, o sistema de classificação passou também a utilizar-se das características genotípicas. Ao longo dos últimos anos, avanços científicos permitiram que fossem sequenciados genomas completos. A cada ano, o número de genomas completamente sequenciados aumenta, e, com isso, é cada vez maior o número de trabalhos que tentam utilizar-se do maior número possível de genes para comparar dois ou mais organismos com o objetivo de melhor entender o relacionamento entre as diversas espécies. Experimento: Este trabalho executa comparações de pares de cromossomos de um grupo de 10 genomas completos da família Vibrionaceae e um genoma completo da bactéria Escherichia coli como externo ao grupo. As homologias entre as proteínas são determinadas através da base de famílias Protein Clusters (NCBI). A seguir, arvores ultramétricas e a classificação COG das proteínas são utilizadas para resolver as paralogias correspondentes. Após isto, as proteínas únicas, que representam os eventos de perda e ganho de genes, são eliminadas, de forma a igualar o conteúdo dos cromossomos. Tipicamente, 50% das proteínas originais do pares de organismos de mesma família 'sobrevivem" para serem utilizadas no cálculo da distância de rearranjo. Menos proteínas sobrevivem nas comparações com a bactéria externa ao grupo. A distância total é calculada pela soma do número de proteínas eliminadas e da distância de ordenação, medida através da distância de rearranjo dos cromossomos. Resultados: As comparações produziram matrizes de distâncias utilizadas para inferir árvores filogenéticas através do algoritmo Neighbor-Joining (NJ). As árvores filogenéticas encontradas mostraram-se congruentes em topologia com a árvore produzida pelo gene 16S rRNA. Isto mostra que a comparação de genomas completos é uma proposta sensata. Os desafios agora são aperfeiçoar os detalhes. O material suplementar (Apêndice A) contém uma implementação computacional dos experimentos
Abstract: Context: Species classification was originally determined by phenotypic characteristics. With the advent of DNA sequencing, the classification system started using genotypes as well. Over the last decades, scientific progress allowed complete sequencing of genomes. Each year, the number of genomes completely sequenced increases, and with it, the number of works trying to use as much genes as possible to compare two or more organisms, in order to get a better understand of the relationship between several species. Experiment: This work executes a pairwise chromosome comparison from a set of 10 complete genomes from the Vibrionaceae family and one complete Escherichia coli genome as an outgroup. In our experiment, the homologies between proteins are assessed using the Protein Clusters (NCBI) database. In the next step, paralogies are resolved using ultrametric trees and COG classification. In the sequel, the loss and gain events are treated, thus, proteins present in only one chromosome from the pair are eliminated, in order to equalize the set of families in both chromosomes. Typically, 50% of the original proteins survive in comparisons between organisms of the same family (comparisons with the outgroup yield less survivors). The total distance is calculated by adding the number of eliminated proteins with the order distance, which is measured by the rearrangement distance beetween the chromosomes. Results: Genome comparison produces distance matrices used to infer the phylogenetic trees through the Neighbor-Joining (NJ) algorithm. The phylogenetic trees generated are congruent regarding the topology with the tree inferred using the 16S rRNA gene. Also, in order to run a deeper investigation, the experiment was executed with some variations such as not resolving the paralogies using ultrametric trees or only classifying proteins using COG database. Supplemental material (Appendix A) contains the experiment computational implementation
Mestrado
Biologia Computaçional
Mestre em Ciência da Computação
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/.
Full textIntroduction - 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
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.
Full textHardman, Andrea M. "Quorum sensing in vibrio anguillarum." Thesis, University of Nottingham, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.363936.
Full textChalker, Victoria J. "Quorum sensing in Vibrio anguillarum." Thesis, University of Nottingham, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.325714.
Full textChow, Ka-hang, and 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.
Full textCarvalho, 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.
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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.
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.
Full text"May, 2004" Includes corrigenda. includes bibliographical references (leaves 118-156).
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.
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