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1
Robino, Etienne. "Etude des amibes marines et de leurs interactions avec les vibrios pathogènes d’huître." Thesis, Montpellier, 2019. http://www.theses.fr/2019MONTG041.
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Les amibes libres dans les environnements aquatiques utilisent la phagocytose des bactéries pour leur nutrition. Selon l’hypothèse de l’évolution fortuite de la virulence, les mécanismes cellulaires et moléculaires de la phagocytose étant conservés des amibes aux cellules immunitaires des animaux, la prédation exercée par les amibes pourraient favoriser l’émergence de bactéries pathogènes résistantes à la phagocytose. Depuis 2008, les huîtres creuses Crassostrea gigas sont victimes d’épisodes de surmortalités en France. Cette pathologie poly-microbienne implique le virus Herpes OsHV-1 µvar qui provoque une immunosuppression des huîtres qui sont alors colonisées par divers bactéries pathogènes opportunistes dont des vibrios induisant la mort de l’animal. V. tasmaniensis LGP32 est un pathogène intracellulaire facultatif des hémocytes d’huître qui résiste à la phagocytose et détruit les hémocytes en utilisant un certain nombre de facteurs de virulence. Nous avons donc entrepris d’étudier les interactions entre les amibes libres de l’environnement ostréicole et les vibrios afin de vérifier si certains mécanismes de virulence pouvaient aussi jouer un rôle dans ce type d’interactions. En réalisant des échantillonnages sur le terrain, nous avons mis en évidence que l’interaction entre vibrios et amibes est écologiquement réaliste, et observé une faible diversité de protistes hétérotrophes près des tables ostréicoles de la lagune de Thau par rapport à d’autres environnements moins anthropisés. Des études fonctionnelles entre LGP32 et l’amibe Vannella sp. AP1411 ont montré que LGP32 est capable de résister à la prédation par les amibes impliquant certains facteurs de virulence comme la métalloprotéase Vsm et la pompe d’efflux du cuivre de type P-ATPase CopA qui sont aussi impliqués dans l’interaction de LGP32 avec les huîtres. En revanche, d’autres facteurs de virulence impliqués chez l’huître ne le sont pas dans la résistance à la prédation par les amibes indiquant que certains facteurs sont impliqués dans des interactions avec divers hôtes tandis que d’autres seraient impliqués dans des interactions plus spécifiquesFree 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
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Poirier, Aurore. "Etude comparative des interactions Vibrio - phagocytes dans l'environnement marin." Thesis, Montpellier, 2015. http://www.theses.fr/2015MONTS062/document.
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Des souches de Vibrio appartenant au clade Splendidus sont retrouvées de manière récurrente lors des mortalités estivales d’huîtres juvéniles. La souche V. tasmaniensis LGP32 est un pathogène intracellulaire facultatif des hémocytes d’huître, dont elle altère les fonctions de défense. Nous nous intéressons ici aux interactions entre les phagocytes et V. tasmaniensis LGP32, à diverses échelles (moléculaire, cellulaire et environnementale). Dans une première partie, nous avons découvert un mécanisme antimicrobien, encore inconnu chez C. gigas : la formation de pièges d'ADN extracellulaire (ETs). Ces ETs sont associés à des histones antimicrobiennes et sont capables de piéger des bactéries. Comme chez les vertébrés, la formation de ces ETs est dépendante de la production d'espèces réactives de l'oxygène. De plus, la présence de ces ETs a été confirmée in vivo et a été associée à une accumulation d'histones antimicrobiennes dans les tissus, suite à une blessure ou à une infection. Dans une seconde partie,nous avons étudié les interactions entre V. tasmaniensis LGP32 et des protistes hétérotrophes présents dans l’environnement des huîtres, tels que les amibes et les ciliés, qui se nourrissent de micro-organismes par phagocytose. Un résultat important de cette thèse a été de montrer que V. tasmaniensis LGP32 résiste également à la phagocytose des protistes hétérotrophes environnementaux, de manière intracellulaire. C'est à notre connaissance la première fois que les mécanismes d’interaction entre des bactéries pathogènes d'origine marine et des amibes marines sont décrits. Les amibes que nous avons isolées étant présentes dans l'environnement direct des huîtres, nous pouvons donc supposer que la pression de sélection exercée par les phagocytes environnementaux pourrait favoriser l’émergence de traits de virulence et/ou de résistance à la phagocytose parmi les bactéries marines, comme c’est le cas pour V. tasmaniensis LGP32Vibrio strains belonging to the Splendidus clade have been repeatedly found in juvenile diseased oysters affected by summer mortalities. V. tasmaniensis LGP32 is an intracellular pathogen of oyster hemocytes which has been reported to alter the oxidative burst and inhibit phagosome maturation.We here focus on the interactions between phagocytes and V. tasmaniensis LGP32, at molecular, cellular and environmental scales. In the first part of this work, we uncover anunknown antimicrobial mechanism of C. gigas hemocytes: the formation of DNA extracellular traps (ETs). These ETs are associated with antimicrobial histones and are able to entrap bacteria. As in vertebrates, ETs formation depends on reactive oxygen species production. In addition, the presence of ETs was confirmed in vivo and has been associated with antimicrobial histones accumulation in tissues, in response to injury or infection. In the second part of this work, we studied the interactions between V. tasmaniensis LGP32 and heterotrophic protists found in the oyster’s environment, such as amoebae and ciliates, which feed on microorganisms by phagocytosis. An important result of this workwas that V. tasmaniensis LGP32 resists to phagocytosis by environmental heterotrophic protists, as well as to oyster hemocytes. To our knowledge, this is the first mechanical description of an interaction between marine amoebae and marine pathogenic bacteria. As the amoebae were isolated from the direct environment of oysters, we can presume that the selective pressure exerted by environmental phagocytes could select for virulence and/or phagocytosis resistance traits in marine bacteria as in the case of V. tasmaniensis LGP32
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Dueñas, Peña Talia Greta Amalia. "Recuento de Vibrio parahaemolyticus Kanagawa positivo en especies marinas de consumo en Lima Metropolitana y Callao." Bachelor's thesis, Universidad Nacional Mayor de San Marcos, 2008. https://hdl.handle.net/20.500.12672/1628.
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El objetivo del presente trabajo fue hacer un recuento de Vibrio parahaemolyticus Kanagawa positivo a partir de 50 muestras de pescados, moluscos y crustáceos crudos procedentes de terminales pesqueros, muelles y supermercados de consumo en Lima Metropolitana y Callao entre noviembre de 1999 y abril de 2000. El análisis microbiológico se realizó de acuerdo a la metodología recomendada por el Manual Bacteriológico Analítico (BAM, 7 ed.). Se halló Vibrio parahaemolyticus Kanagawa positivo en 4 muestras aislándose 5 cepas con las características bioquímicas correspondientes de un total de 568 cepas sospechosas. Los valores hallados de Número Más Probable (NMP) fueron en pescados y crustáceos de 3/g cada uno y en moluscos un valor mínimo de 3/g y un máximo de 7,4/g. Las muestras que presentaron Vibrio parahaemolyticus Kanagawa positivo (n=4) representaron un 8% del total de especies marinas (n=50), siendo los porcentajes hallados en pescados 2% (n=1), moluscos 4% (n=2) y crustáceos 2% (n=1).
-- Palabras Clave: Vibrio parahaemolyticus, pescados, crustáceos, moluscos, Kanagawa positivo, NMP, Lima Metropolitana y Callao.-- The aim of this research was performing a count of Vibrio parahaemolyticus Kanagawa positive out of 50 samples including raw fish, mollusks and crustaceans collected from fishermen’s wharf, fisheries, and supermarkets of edible character in Metropolitan Lima and Callao between november 1999 and april 2000. The microbiological analysis was performed according to Bacteriological Analytical Manual (BAM, 7 ed.). Vibrio parahaemolyticus Kanagawa positive was found in 4 samples from 5 strains with biochemical features that met those of Vibrio parahaemolyticus out of a total of 568 analized strains. The Most Probable Number (NMP) values found are as follows: Fish and crustaceans 3/g each, while molluscs had a minimum value of 3/g and a maximum of 7,4/g. Vibrio parahaemolyticus Kanagawa positive samples (n=4) represented 8% out of the total marine samples (n=50), being the percentages found in fish 2% (n=1), mollusks 4% (n=2) and crustaceans 2% (n=1) out of the total number of samples as well. -- Key Words: Vibrio parahaemolyticus, fish, mollusks, crustaceans, Kanagawa positive, MPN, Metropolitan Lima and Callao.
Tesis
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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.
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The eastern oyster Crassostrea virginica is an ecologically and commercially important species whose natural populations have been devastated by overharvesting, habitat destruction, and disease, but the rapid growth of oyster aquaculture has shown potential to restore the economic significance of this species. A key threat to the growth and sustainability of oyster aquaculture is the association of human-pathogenic Vibrio bacteria with product marketed for raw consumption. Two Vibrio species, Vibrio vulnificus and Vibrio parahaemolyticus, are the causes of the highest rates of seafood consumption-related mortality and gastrointestinal illness, respectively. Identification of the factors influencing V. vulnificus and V. parahaemolyticus prevalence and intensity in oysters is fundamental to better risk management. Within the oyster, these bacterial species interact with the same tissues as the prevalent oyster parasite, Perkinsus marinus, yet little is known about the effect of P. marinus infection on bacterial levels. Answering the fundamental question of whether P. marinus correlates with V. vulnificus and V. parahaemolyticus levels in oysters was the focus of this research. Oysters were deployed in the York River, Gloucester Point, VA, where both Vibrio species and P. marinus are endemic, and were sampled at five time points when levels of both P. marinus and Vibrio spp. were expected to be high in oysters. Abundance of all three organisms and pathogenic strains of V. parahaemolyticus were determined in individual oysters using molecular methods to investigate potential correlations between parasite and bacterial abundance. Additionally, the levels of V. vulnificus and V. parahaemolyticus in relation to histopathology associated with P. marinus infection and other conditions were determined. The following year, manipulation of P. marinus disease progression, which is slowed by lower salinities and favored by higher salinities, was attempted by deploying oysters at two additional sites of different salinities to gain insight into whether the timing of P. marinus infection emergence directly influences Vibrio levels. No correlation was observed between total abundance of P. marinus and either V. vulnificus or V. parahaemolyticus. Manipulation of P. marinus disease progression produced no effect on P. marinus emergence, so this yielded no insight into P. marinus-Vibrio interactions. Histopathological analyses did not reveal any correlations between P. marinus ranking, distribution, or associated tissue damage and Vibrio spp. levels. Though few in number, oysters infected by Haplosporidium nelsoni were characterized by higher levels of V. vulnificus, and oysters of peak gametogenic development had significantly higher levels of pathogenic strains of V. parahaemolyticus. The results with regard to H. nelsoni and gametogenic state warrant further study. The primary conclusion of this study is that oyster health has little influence on levels of human-pathogenic Vibrio species in oysters, inter-host variability in Vibrio levels is likely explained by other factors.
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CARVALHO, Joana Angélica Lyra Vogeley de. "Efeito do uso de bactérias probióticas na sobrevivência de larvas de Litopenaeus vannamei expostas à infecção experimental por Vibrio spp." Universidade Federal Rural de Pernambuco, 2011. http://www.tede2.ufrpe.br:8080/tede2/handle/tede2/6339.
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES
This study aimed to evaluate the survival of Litopenaeus vannamei shrimp larvae treated with probiotic bacteria and subsequently infected by Vibrio harveyi and Vibrio alginolyticus. Shrimp were kept in two 80L tanks under similar culture conditions, but only one tank was previously treated with commercial probiotic (Bacillus spp.) added daily in the water at a concentration of 105 CFU/ml. This protocol was maintained until the animals reach the stage of development needed for the infection experiments by Vibrio spp. Three independent infection experiments were performed: Zoea1 to Zoea3, Mysis1 to Mysis3 and Postlarvae (PL)10 to PL14 with the following treatments with four replicates each: only V. harveyi; commercial probiotic + V. harveyi; only V. alginolyticus; commercial probiotic + V. alginolyticus; and without Vibrio spp. and probiotic (Control). In the experiment with PL, only the treatments with V. harveyi; commercial probiotic + V. harveyi and control were used. Vibrio species were inoculated only at the beginning of each experiment at a concentration of 107 CFU/ml. At the end of experiments, a sample of water and shrimp from each experimental unit was submitted to quantification of Vibrio spp. Additionally, was realized an antagonism test of Bacillus spp. against Vibrio spp. In the experiments with zoea and mysis, larvae cultured in treatment V. harveyi had a significantly lower survival when compared with treatments V. alginolyticus and control. There was a significant increase in survival of zoea and mysis larvae treated with probiotic + V. harveyi with 81.07 and 90.13%, differentiating the larvae infected only with V. harveyi with 12.80 and 69.13%, respectively. There were no significant differences in survival of postlarvae among treatments. Total Vibrio spp. counts decreased in the water and shrimp of treatments with the use of probiotic. The probiotic (Bacillus spp.) showed inhibitory activity against Vibrio spp. in vitro. The results indicated an increase in the survival of early larval stages (zoea and mysis) infected by V. harveyi after treatment with Bacillus spp. The administration of probiotic bacteria is a promising alternative for the prevention of Vibrio spp. in larviculture of L. vannamei.
O presente estudo teve como objetivo avaliar a sobrevivência de larvas de Litopenaeus vannamei tratadas com bactérias probióticas e posteriormente infectadas por Vibrio harveyi e Vibrio alginolyticus. Os camarões foram mantidos em dois tanques de 80L nas mesmas condições, mas apenas um deles foi previamente tratado com probiótico comercial (Bacillus spp.) adicionado diariamente na água na concentração de 105 UFC/ml. Este protocolo foi mantido até os animais alcançarem o estágio de desenvolvimento larval necessário para os experimentos de infecção por Vibrio spp. Foram realizados três experimentos independentes de infecção: Zoea1 a Zoea3, Mísis1 a Mísis3 e Pós-larvas (PL)10 a PL14 com os seguintes tratamentos com quatro repetições cada: somente V.harveyi; probiótico comercial + V. harveyi; somente V. alginolyticus; probiótico comercial + V. alginolyticus; sem Vibrio spp. e probiótico (controle). No experimento com PL, somente os tratamentos com V. harveyi; probiótico comercial + V. harveyi e controle foram utilizados. As espécies de Vibrio foram inoculadas apenas no início de cada experimento na concentração de 107 UFC/ml. Ao final dos experimentos, uma amostra de água e camarão de cada parcela experimental foi submetida à quantificação de Vibrio spp. Adicionalmente foi realizado um teste de antagonismo in vitro de Bacillus spp. contra Vibrio spp. Nos experimentos com zoea e mísis, as larvas cultivadas no tratamento V. harveyi apresentaram uma sobrevivência significativamente inferior quando comparadas com as dos tratamentos V. alginolyticus e controle. Houve um aumento significativo na sobrevivência de larvas zoea e mísis tratadas com probiótico + V. harveyi com 81,07 e 90,13%, em comparação com as larvas infectadas apenas com V. harveyi com 12,80 e 69,13%, respectivamente. Não foram observadas diferenças significativas na sobrevivência das pós-larvas entre tratamentos. A quantidade total de Vibrio spp. na água e camarões diminuiu nos tratamentos com o uso de probiótico. O probiótico (Bacillus spp.) apresentou atividade inibitória contra Vibrio spp. in vitro. Os resultados indicaram um aumento na sobrevivência dos estágios larvais iniciais (zoea e mísis) infectadas por V. harveyi após tratamento com Bacillus spp. A administração de bactérias probióticas é uma alternativa promissora para a prevenção de Vibrio spp. na larvicultura de L. vannamei.
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Trubitsyn, Denis. "Magnetosome formation in marine vibrio MV-1." Thesis, University of Edinburgh, 2010. http://hdl.handle.net/1842/7589.
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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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Flores, Dominick Violeta de Jesús. "Aislamiento y caracterización de un bacteriófago con actividad lítica para Vibrio fluvialis." Master's thesis, Universidad Nacional Mayor de San Marcos, 2017. https://hdl.handle.net/20.500.12672/7007.
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Aisla un bacteriófago lítico denominado Vf1, procedente del mar peruano, capaz de infectar a Vibrio fluvialis, bacteria que afecta humanos y organismos acuáticos. El bacteriófago Vf1 fue caracterizado con respecto a su morfología, estabilidad térmica, diferentes rangos de pH, sensibilidad frente al cloroformo, exposición a la luz UV, rango de hospederos y la curva de crecimiento de un paso. La microscopía electrónica de transmisión, evidenció cabeza de forma icosaedrica con un diámetro de 82.773 nm y un talo largo no contráctil de 142.318 nm de longitud, características propias a la familia Siphoviridae. El fago Vf1, fue resistente al calor a 20°C por 30 minutos, perdiendo su viabilidad a partir de 50 y 60°C; y en valores de pH entre 7 y 8 mantuvo títulos elevados, disminuyendo el título entre 5 y 6, siendo nulo a valores de pH ácido. La viabilidad frente a la exposición al cloroformo, evidenció una reducción en el título del 50% y frente a la luz UV, la reducción fue del 100% a 90 segundos de exposición. En la curva de crecimiento de un paso evidenció un período de latencia de 20 minutos y el tamaño de la explosión o burst size fue 602 partículas por centro infectivo. Los parámetros biológicos evaluados en este estudio evidenciaron el potencial del bacteriófago Vf1 para poder ser utilizado en fagoterapia, además, la metodología evaluada podría ser utilizado para el aislamiento de otros bacteriófagos de ambientes marinos.Tesis
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Girard, Léa. "Quorum Sensing in Vibrio spp. : AHL diversity, temporal dynamic and niche partitioning." Thesis, Paris 6, 2017. http://www.theses.fr/2017PA066650/document.
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Chez les Vibrio spp., le QS est impliqué dans de nombreuses fonctions comme la colonisation de niche écologiques, les stratégies de survie ou encore la virulence. Cependant, pour la majorité des espèces de Vibrio, la diversité des AHLs produites reste largement sous-estimée et l'étude du QS est encore limitée à quelques espèces modèles ou pathogènes. Toutefois, dans les environnements aquatiques, ces espèces sont minoritaires et les espèces les plus abondantes ne sont que très peu étudiées. Nos résultats ont révélé une importante diversité d'AHLs mais aussi, de façon surprenante, une hétérogénéité dans les phénotypes de production d'AHL au sein d'une même espèce de Vibrio. Pour la première fois, nous avons mis en évidence qu'une même souche de Vibrio pouvait présenter des phénotypes de production d'AHLs différent au cours du temps et une approche statistique a révélé l'implication de certains déterminants biotiques et abiotiques dans ces variations temporelles. Par ailleurs, une approche à micro-échelle a révélé une structuration des populations de Vibrio en unités fonctionnelles constituées de souches phylogénétiquement proches qui partagent des niches écologiques spécifiques et des comportements sociaux. Nos résultats ont mis en évidence que les modalités de communication pouvaient être hétérogènes suggérant l'absence d'un langage commun au sein de ces unités fonctionnelles. En conclusion, ce travail de thèse a permis d'apporter de nouvelles connaissances sur le QS chez les Vibrio dans l'environnement marin, de la souche à la population, et propose une vision intégrée des mécanismes de régulation de la production d'AHLs dans l'environnementQuorum sensing is an important mechanism among Vibrio species and is involved in many vital functions such as niche colonization, survival strategies or virulence. However, AHL diversity still largely underestimated for the majority of Vibrio species and the current knowledge on AHL-mediated QS is limited to a few pathogenic or bioluminescent species. Nonetheless, these species are weakly abundant in seawater while dominant species in the environment are poorly studied. Our results revealed a unexpected diversity of AHL molecules but also a quite surprising intra-species diversity of AHL production phenotypes. For the first time, we showed that different isolates of a single genotype switched between different AHL production phenotypes among time and we revealed the potential involvement of abiotic and biotic parameters in these variations. However, it appears that when studied at a microscale, Vibrio populations are showing a functional structuration in ecological units consisting of phylogenetically close strains sharing habitat and social traits. In this context, it was necessary to determine if these different AHL production phenotypes were associated to different micro-habitats in the water column. We did not demonstrate that a common language was spoken within ecological populations. This thesis work provide new insights on AHL-mediated QS among a broader range of species and among Vibrio populations and depicts the potential impact of multiple aspects of marine environments on AHL production
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Lavezzo, 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/.
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Neste estudo, objetivou-se caracterizar ao nível molecular os vibrios isolados de amostras de água do mar, plâncton e bivalves do Canal de São Sebastião (n=78), Baixada Santista (n=37) e Ubatuba (n=17), analisar a susceptibilidade aos antibióticos e os principais genes associados à virulência. Observou-se sensibilidade à ciprofloxaxina, meropenem e ácido nalidíxico, resistência à ampicilina e à cefalotina, e alta porcentagem de múltipla resistência (Ubatuba: 64,7%; Baixada Santista:48,6%; Canal de São Sebastião: 43%) aos antimicrobianos. Quatro isolados foram positivos para o gene de virulência stn/sto. Por MLSA, foi possível identificar V.alginolyticus, V.fluvialis, V.campbellii e V.harveyi em Ubatuba; V.fluvialis, V.alginolyticus, V.campbellii, V.rotiferianus, V.harveyi, V.diabolicus, V.atypicus, V.coralliilyticus, V.maritimus, V.parahaemolyticus e V.tubiashii no Canal de São Sebastião; e, V.alginolyticus, V.parahaemolyticus, V.rotiferianus, V.campbellii, V.harveyi, V.communis, V.maritimus, V.fluvialis, V.fortis, V.natriegens e V.navarrensis na Baixada Santista.The 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.
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Neto, Antonio Alves dos Santos. "Biologia computacional aplicada à análise de dados de microarranjos do genoma da bactéria marinha vibrio parahaemolyticus em presença de n-acetilglicosamina." Laboratório Nacional de Computação Científica, 2010. http://www.lncc.br/tdmc/tde_busca/arquivo.php?codArquivo=210.
Full textAbstract:
A análise da expressão gênica em larga escala é de fundamental importância para a melhor compreensão do funcionamento celular e dos mecanismos de regulação gênica. Ela possibilita a medida dos níveis de expressão de milhares de genes simultaneamente, o que torna possível uma visão mais abrangente do sistema biológico. Dentre as principais técnicas experimentais disponíveis para esta finalidade, a tecnologia de microarranjo tem sido amplamente utilizada. O objetivo desta dissertação foi determinar os genes de V. parahaemolyticus que têm sua expressão induzida ou reprimida na presença do aminoaçúcar N-acetilglucosamina (NAG). V. parahaemolyticus é uma bactéria marinha, comumente encontrada na água e em associação com organismos marinhos. O NAG é um dos aminoaçúcares mais abundantes no meio marinho. Para isso, Vibro parahaemolyticus RIMD2210633, foi cultivada em dois meios como fontes de energia. O primeiro meio composto por maltose e NAG e o segundo apenas por NAG. O cultivo bacteriano foi feito em condições aeróbicas, sob baixa agitação, a 28C. Foram retiradas duas amostras do cultivo no tempo de 24 horas após o início do experimento a fim de realizar a extração de mRNA e a preparação do cDNA. Os experimentos foram feitos em três replicas. As misturas de cDNA preparadas a partir do RNA extraído de cada réplica foram utilizadas em hibridizações em lâminas de microarranjo contendo um total de 4832 ORFS do genoma de V. parahaemolyticus RIMD2210633. A análise comparativa da expressão gênica de V. parahaemolyticus nas duas condições de cultivo resultou na detecção de 59 genes com expressão induzida, 38 genes reprimidos, e 4245 sem expressão modificada (aumentada ou diminuída) na presença de NAG. No total, 523 genes foram excluídos da comparação pois a hibridização não foi satisfatória. Ocorreu uma ordenação dos genes seguindo a classificação funcional do banco de dados TIGR-CMR e KEGG. Os genes com expressão induzida, pertencem principalmente às classes de funções regulatórias, metabolismo de energia, e proteínas de transporte. Foram também encontradas proteínas PilA e de quimiotaxia, sugerindo um papel da NAG na transformação. Já os genes de expressão reprimida compreendem principalmente as funções de metabolismo de energia, endereçamento celular, e proteínas hipotéticas. O presente estudo demonstrou que NAG interfere na regulação de diferentes processos celulales, incluindo a capacidade de captura de DNA do meio por V. parahaemolyticus.Large scale gene expression analysis has fundamental importance for understanding cellular function and gene regulation mechanics. It enables the measurement of expression levels of thousands of genes simultaneously, and makes possible a wider understanding of the biological system. Among the main experimental techniques available for this purpose, microarray technology has been widely used. The objective of this work was to determine the genes of Vibrio parahaemolyticus which have their expression induced or repressed in presence of amino-sugars N-acetylglucosamine (NAG). V. parahaemolyticus is a marine bacterium, commonly found in water and in association with marine organisms. NAG is one of the most abundant amino sugars in the marine environment. For this, V. parahaemolyticus RIMD2210633, was cultivated in two media as sources of energy. The first medium consists of maltose and NAG (control) and the second only by NAG (treatment). Bacterial culture was done under aerobic conditions and low agitation at 28C. Two samples were drawn from the medium 24 hours after the experiment beginning in order to perform the extraction of mRNA and preparation of cDNA. Three replicas of the experiments were made. Mixtures of cDNA prepared from RNA extracted from each replicate were used in hybridizations in microarray slides containing a total of 4832 ORFS from the V. parahaemolyticus RIMD2210633 genome. Comparative analysis of gene expression of V. parahaemolyticus in two culture conditions resulted in detection of 59 genes with expression induced, 38 repressed genes, and 4245 without modified expression (increased or decreased) in presence of NAG. In total, 523 genes were excluded from this comparison because the hybridization was unsatisfactory. There was a gene ordination following the functional classification of the database TIGR-CMR and KEGG. The genes with induced expression mainly belong to classes of regulatory functions, energy metabolism, and transport proteins. PilA and Chemotaxis proteins were found, suggesting a role of NAG in the transformation. Repressed expression genes are mainly included in the functions of energy metabolism, cell address, and hypothetical proteins. This study demonstrated that NAG interfere in regulation of different cell processes, including the ability to capture DNA from the medium by V. parahaemolyticus.
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Rubio, 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 textAbstract:
Au sein du clade Splendidus, Vibrio tasmaniensis et Vibrio crassostreae sont deux populations de vibrios virulentes pour l’huître qui ont été associées au syndrome de mortalité des huîtres juvéniles. Nous nous sommes intéressés à la diversité des mécanismes d'interaction entre ces vibrios et leur hôte, l'huître creuse Crassostrea gigas. Dans un premier temps, nous avons précisé le processus de pathogénèse de la souche V. tasmaniensis LGP32 et montré qu’elle possédait une activité cytotoxique sur les cellules immunitaires de l’huître, les hémocytes, qui dépendait de sa phagocytose. Le transcriptome intracellulaire de LGP32 a révélé le rôle important des systèmes antioxydants et de l’efflux du cuivre dans la survie du vibrio à l’intérieur du phagosome. D’un point de vue fonctionnel, nous avons montré que ces mécanismes jouaient un rôle important au cours de la pathogénèse in vivo. Dans un second temps, nous avons réalisé une étude comparative des interactions entre des souches représentatives des deux populations V. tasmaniensis et V. crassostreae et l’huître. Nous avons montré que les souches virulentes des deux populations étaient cytotoxiques pour les hémocytes mais que cette cytotoxicité était indépendante de la phagocytose chez les V. crassostreae, à l’inverse des V. tasmaniensis. Le transcriptome des huîtres a montré que les souches virulentes des deux populations réprimaient l’expression de gènes impliqués dans la réponse antibactérienne. Des réponses spécifiques à chaque souche virulente ont également été identifiées, révélant la diversité des interactions. In vivo, les souches virulentes se sont montrées capables de coloniser les tissus de l'huitre, contrairement aux souches non virulentes contrôlées par les hémocytes. L’ensemble de nos travaux montre que, bien qu’il existe un degré de diversité et de spécificité des interactions entre différents vibrios du clade Splendidus et l’huître, les deux populations virulentes sont cytotoxiques pour les cellules immunitaires, et ce processus est essentiel pour leur succès infectieux. Ainsi, la capacité de dépasser les défenses hémocytaires est un phénotype conservé entre les populations virulentes du clade Splendidus. Les processus évolutifs ayant conduits à l’émergence de ces traits de virulence communs entre populations de vibrios pathogènes différentes méritent d’être explorerIn 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
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Tarazona, Janampa Ulrike Inge. "Caracterización de actinomicetos de sedimento marino y su potencial actividad antagonista frente a Vibrio sp. aislados de Litopenaeus vannamei." Bachelor's thesis, Universidad Nacional Mayor de San Marcos, 2017. https://hdl.handle.net/20.500.12672/5704.
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Evalúa la actividad antagonista de una colección de 25 actinomicetos de origen marino. La actividad inhibitoria se determina mediante pruebas in vitro sobre cepas de Vibrio aislados de Litopenaeus vannamei (Langostino Blanco).Tesis
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Lima, Anahy de Souza. "Víbrio em camarão e na água de três fazendas de carcinicultura do Ceará." http://www.teses.ufc.br/, 2007. http://www.repositorio.ufc.br/handle/riufc/1309.
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LIMA, Anahy de Souza. Víbrio em camarão e na água de três fazendas de carcinicultura do Ceará. 2007. 74f. Dissertação (Mestrado em Ciencias Marinhas Tropicais)- Instituto de Ciências do Mar, Universidade Federal do Ceará, Fortaleza, 2007.Submitted by Debora Oliveira (deby_borboletinha@hotmail.com) on 2011-11-29T12:22:03Z No. of bitstreams: 1 2007_dis_adslima.pdf: 2071706 bytes, checksum: 515e8e6c8c757b34d245885074813a89 (MD5)
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The objective of the present study was to identify Vibrio species in cultures of Litopenaeus vannamei in Northeastern Brazil. During the rainy and dry seasons from August 2005 to October 2006 two L. vannamei culture cycles were observed on three marine shrimp farms (A, B and C) located in the estuaries of Acaraú, Coreaú and Jaguaribe. Sixty shrimp samples and 240 pond water samples were analyzed. The outcome parameters were total vibrio count (standard plate count), saccharose-positive and negative vibrio count, and vibrio species diversity in shrimp and water samples. The lowest total vibrio count found in water samples was 2.0 x 102 CFU/mL (Farms A, and C) during the rainy season and the highest was 1,42 x 108 CFU/mL (Farm B) during the rainy season. The highest total vibrio count in shrimp samples (postlarvae and hepatopancreas) was 4,5 x 108 CFU/g (Farm B) during the dry season. The lowest and highest values observed for saccharosepositive colonies in hepatopancreas were 1.00 x 102 CFU/g (Farms A, and B) during the rainy season and 4,5 x 108 CFU/g (Farm C) during the dry season. The corresponding values for saccharose-negative colonies were 0.98 x 10 CFU/g (Farm A) and 9.50 x 105 CFU/g (Farm C), both in the rainy season. Vibrio counts were always lower in samples collected during the rainy season. A total of 118 Vibrio strains were isolated from the water (n=62) and shrimp (n=56) samples collected at the three farms. Farm B had the largest number of identifiable vibrio species (11). The most frequently isolated species was Vibrio mimicus, followed by V. alginolyticus and V. tubiashii. The lowest survival rate (37.24%) during harvesting was observed for one of the ponds at Farm A during the rainy season. Neither species diversity, nor total vibrio counts, nor saccharosepositive and negative vibrio counts in hepatopancreas samples, was associated with survival rates during harvesting. However, the combination of high vibrio counts and low species diversity observed in water samples from Farm A during the rainy season may have affected survival rates negatively. The number of vibrios increases in proportion with salinity. The likelihood of a vibrio infection in a given shrimp population cannot be determined by total vibrio counts or saccharosepositive and negative counts alone.
O presente estudo teve por objetivo quantificar Vibrio, vibrios sac+ e sac – e identificar as espécies de Vibrio, presentes no cultivo do camarão Litopenaeus vannamei e na água onde é ele cultivado. Acompanharamse dois ciclos do cultivo do L. vannamei em três fazendas (A, B e C),situadas nos estuários dos rios Acaraú, Coreaú e Jaguaribe (CE), de agosto de 2005 a outubro de 2006, nas estações de chuva e estiagem. Foram analisadas 60 amostras de camarão e 240 amostras de água de viveiro. Foram feitos os testes de Contagem Padrão em Placas (CPP) total de Vibrio; CPP das colônias de Vibrio sacarose positivas e negativas, e identificação das espécies nas amostras de camarão e na água. O valor mínimo da CPP de Vibrio nas amostras de água foi de 2,0 x 102 UFC/mL nas fazendas A, e C no período de chuva e o máximo foi 1,42 x 108 UFC/mL na fazenda B, no período de estio. O valor máximo para CPP de Vibrio nas amostras de camarão (pós-larva e hepatopâncreas) foi de 4,5 x 108 UFC/g, na fazenda B no período de estio. O valor mínimo de Vibrio sacarose positiva no hepatopâncreas foi 1,00 x 102 UFC/g nas fazendas A e B no período de chuva e máximo foi 4,5 x 108 UFC/g na fazenda B, no período de estio. O valor mínimo de Vibrio sacarose negativa foi 0,98 x 10 UFC/g de hepatopâncreas na fazenda A, no período de chuva e máximo foi de 9,50 x 105 na fazenda C no período da chuva. A CPP de vibrios das amostras de água e do camarão foi sempre menor no período da chuva. Das amostras de água e camarão das três fazendas foram isoladas 145 cepas de Vibrio. Dessas, 62 foram isoladas da água de cultivo do camarão e 56 foram isoladas do camarão (pós-larva e hepatopâncreas). A fazenda B apresentou maior número de diferentes espécies isoladas e identificadas (11). Durante a pesquisa, os isolados de camarão e água do viveiro, apresentaram uma predominância de Vibrio mimicus, seguidos de V. alginolyticus e V. tubiashii. De todas as fazendas, A, B e C, a fazenda A foi a que apresentou um viveiro com a menor taxa de sobrevivência de camarões na despesca: 37,24%, no período da chuva. Nem a quantidade de víbrios total, nem a de sacarose positiva, ou negativa no hepatopâncreas dos camarões, influencia o índice de sobrevivência dos animais nos viveiros das fazendas, no momento da despesca. A maior ou menor diversidade de víbrios nos camarões não implicou numa maior ou menor taxa de sobrevivência dos animais nos viveiros das fazendas, no momento da despesca. No entanto, quando o número de Vibrio foi alto na água e a diversidade baixa, caso da Fazenda A no período da chuva, a taxa de sobrevivência foi afetada negativamente. O número de víbrios é proporcional ao teor de salinidade das águas. Somente os dados da enumeração de víbrios e/ou os dados da enumeração de víbrio sacarose positiva ou negativa não são suficientes para se avaliar a probabilidade de camarões, de um determinado viveiro, virem a adoecer.
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Sulca, Lopez Marcos Alejandro. "Identificación y caracterización de integrones y su asociación con la resistencia a antibióticos en cepas de Vibrio spp. aisladas de ambientes marinos contaminados de Lima-Perú." Master's thesis, Universidad Nacional Mayor de San Marcos, 2010. https://hdl.handle.net/20.500.12672/3326.
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La investigación tuvo como objetivo incorporar una metodología de identificación rápida conocida como ARDRA (Amplified Ribosomal DNA Restriction Analysis) para identificar especies del género Vibrio.
Se estandarizó la técnica con cepas referenciales. Luego, se aislaron cepas bacterianas asociadas con el cultivo de Litopenaeus vannamei. Posteriormente, se realizaron pruebas bioquímicas para encontrar cepas candidatas de pertenecer al género Vibrio. Al finalizar esta primera etapa, la técnica ARDRA estandarizada, fue aplicada en las cepas candidatas, confirmando de esta manera la factibilidad de la metodología bajo las condiciones estudiadas.
En una segunda etapa, se secuenció la región 16S rDNA para confirmar e identificar las cepas candidatas por análisis filogenético. Se reportaron tres especies diferentes con alta similitud pertenecientes al Vibrio core group (Vibrio communis, Vibrio harveyi y Vibrio parahaemolyticus). Con estos resultados, fue posible diseñar una identificación rápida por ARDRA para identificar el Vibrio core group y la especie Vibrio communis. La metodología de diseño del ARDRA fue soportado por una valoración diagnóstica bioinformática, obteniendo de esta evaluación, una sensibilidad y una especificidad de 97,1 y 76,9%, respectivamente para la identificación del Vibrio core group, mientras que para identificar la especie Vibrio communis, se obtuvo una sensibilidad y una especificidad de 100 y 97,4%, respectivamente.
Finalmente, se ha demostrado que es posible identificar ciertas especies del genero Vibrio asociados con la acuicultura de Litopenaeus vannamei, por ARDRA y esta metodología de identificación, tiene la ventaja de ser mucho más rápido y económico en comparación con la identificación por análisis filogenético, teniendo a su vez la desventaja de ser dependiente del uso del secuenciamiento en un primer momento para el diseño del ARDRA.
Palabras clave: Litopenaeus vannamei, ARDRA, Vibrio communis, Vibrio harveyi, Vibrio parahaemolyticus, Vibrio core group, evaluación diagnóstica bioinformática.--- The research aimed to incorporate a quick identification methodology known as ARDRA (Amplified Ribosomal DNA Restriction Analysis) to identify Vibrio species. Technique was standardized with reference strains. Then, bacterial strains were isolated associated with the cultivation of Litopenaeus vannamei. Subsequently, biochemical tests were performed to find candidate strains belonging to the genus Vibrio. Upon completion of this first stage, the standard technique (ARDRA) was applied for candidate strains, thus confirming the feasibility of the method under the conditions studied. In a second step, the 16S rDNA region sequenced to confirm and identify candidate strains for phylogenetic analysis. Three different species were reported with high similarity belonging to the Vibrio core group (Vibrio communis, Vibrio harveyi and Vibrio parahaemolyticus). With these results, it was possible to design a quick identification by ARDRA to identify the Vibrio core group and Vibrio communis. The design methodology ARDRA was supported by a bioinformatics diagnostic assessment, obtaining this evaluation, a sensitivity and specificity of 97,1 and 76.9% respectively for the identification of Vibrio core group, while identifying the species Vibrio communis, yielded a sensitivity and specificity of 100 and 97,4%, respectively. Finally, it has proved possible to identify certain Vibrio species associated with aquaculture Litopenaeus vannamei, by ARDRA identification and this methodology has the advantage of being much faster and cheaper compared with the identification by phylogenetic analysis, having in turn, the disadvantage of being dependent on the use of the sequencing at first for ARDRA design. Keywords: Litopenaeus vannamei, ARDRA, Vibrio communis, Vibrio harveyi, Vibrio parahaemolyticus, Vibrio core group, bioinformatic diagnostic evaluation.
Tesis
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Santos, Neto Antonio Alves dos. "Biologia computacional aplicada à análise de dados de microarranjos do genoma da bactéria marinha vibrio parahaemolyticus em presença de n-acetilglicosamina." Laboratório Nacional de Computação Científica, 2010. https://tede.lncc.br/handle/tede/133.
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Previous issue date: 2010-03-11Coordenacao de Aperfeicoamento de Pessoal de Nivel Superior
Large scale gene expression analysis has fundamental importance for understanding cellular function and gene regulation mechanics. It enables the measurement of expression levels of thousands of genes simultaneously, and makes possible a wider understanding of the biological system. Among the main experimental techniques available for this purpose, microarray technology has been widely used. The objective of this work was to determine the genes of Vibrio parahaemolyticus which have their expression induced or repressed in presence of amino-sugars N-acetylglucosamine (NAG). V. parahaemolyticus is a marine bacterium, commonly found in water and in association with marine organisms. NAG is one of the most abundant amino sugars in the marine environment. For this, V. parahaemolyticus RIMD2210633, was cultivated in two media as sources of energy. The first medium consists of maltose and NAG (control) and the second only by NAG (treatment). Bacterial culture was done under aerobic conditions and low agitation at 28°C. Two samples were drawn from the medium 24 hours after the experiment beginning in order to perform the extraction of mRNA and preparation of cDNA. Three replicas of the experiments were made. Mixtures of cDNA prepared from RNA extracted from each replicate were used in hybridizations in microarray slides containing a total of 4832 ORFS from the V. parahaemolyticus RIMD2210633 genome. Comparative analysis of gene expression of V. parahaemolyticus in two culture conditions resulted in detection of 59 genes with expression induced, 38 repressed genes, and 4245 without modified expression (increased or decreased) in presence of NAG. In total, 523 genes were excluded from this comparison because the hybridization was unsatisfactory. There was a gene ordination following the functional classification of the database TIGR-CMR and KEGG. The genes with induced expression mainly belong to classes of regulatory functions, energy metabolism, and transport proteins. PilA and Chemotaxis proteins were found, suggesting a role of NAG in the transformation. Repressed expression genes are mainly included in the functions of energy metabolism, cell address, and hypothetical proteins. This study demonstrated that NAG interfere in regulation of different cell processes, including the ability to capture DNA from the medium by V. parahaemolyticus.
A análise da expressão gênica em larga escala é de fundamental importância para a melhor compreensão do funcionamento celular e dos mecanismos de regulação gênica. Ela possibilita a medida dos níveis de expressão de milhares de genes simultaneamente, o que torna possível uma visão mais abrangente do sistema biológico. Dentre as principais técnicas experimentais disponíveis para esta finalidade, a tecnologia de microarranjo tem sido amplamente utilizada. O objetivo desta dissertação foi determinar os genes de V. parahaemolyticus que têm sua expressão induzida ou reprimida na presença do aminoaçúcar N-acetilglucosamina (NAG). V. parahaemolyticus é uma bactéria marinha, comumente encontrada na água e em associação com organismos marinhos. O NAG é um dos aminoaçúcares mais abundantes no meio marinho. Para isso, Vibro parahaemolyticus RIMD2210633, foi cultivada em dois meios como fontes de energia. O primeiro meio composto por maltose e NAG e o segundo apenas por NAG. O cultivo bacteriano foi feito em condições aeróbicas, sob baixa agitação, a 28°C. Foram retiradas duas amostras do cultivo no tempo de 24 horas após o início do experimento a fim de realizar a extração de mRNA e a preparação do cDNA. Os experimentos foram feitos em três replicas. As misturas de cDNA preparadas a partir do RNA extraído de cada réplica foram utilizadas em hibridizações em lâminas de microarranjo contendo um total de 4832 ORFS do genoma de V. parahaemolyticus RIMD2210633. A análise comparativa da expressão gênica de V. parahaemolyticus nas duas condições de cultivo resultou na detecção de 59 genes com expressão induzida, 38 genes reprimidos, e 4245 sem expressão modificada (aumentada ou diminuída) na presença de NAG. No total, 523 genes foram excluídos da comparação pois a hibridização não foi satisfatória. Ocorreu uma ordenação dos genes seguindo a classificação funcional do banco de dados TIGR-CMR e KEGG. Os genes com expressão induzida, pertencem principalmente às classes de funções regulatórias, metabolismo de energia, e proteínas de transporte. Foram também encontradas proteínas PilA e de quimiotaxia, sugerindo um papel da NAG na transformação. Já os genes de expressão reprimida compreendem principalmente as funções de metabolismo de energia, endereçamento celular, e proteínas hipotéticas. O presente estudo demonstrou que NAG interfere na regulação de diferentes processos celulales, incluindo a capacidade de captura de DNA do meio por V. parahaemolyticus.
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Suárez, Cárdenas Katherine Olimpia. "Aislamiento y caracterización de un bacteriófago específico de Vibrio cholerae procedente de aguas residuales de Lima - Perú." Bachelor's thesis, Universidad Nacional Mayor de San Marcos, 2017. https://hdl.handle.net/20.500.12672/7454.
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Publicación a texto completo no autorizada por el autorPresenta a los bacteriófagos que son biocontroladores naturales de las bacterias como una alternativa para el control de las poblaciones de Vibrio cholerae, causantes de la enfermedad de transmisión alimentaria (ETA). El objetivo de este trabajo es aislar y caracterizar bacteriófagos capaces de infectar a Vibrio cholerae. Se toman muestras de aguas residuales de Lima - Perú. Los métodos empleados son para el aislamiento de Vibrio cholerae enriqueciendo, aislando en medio TCBS y bioquímica. Para el aislamiento y purificación del bacteriófago Φ K14 se realiza las pruebas de enfrentamiento en caldo, goteo, propagación y titulación. Para la caracterización microbiológica del bacteriófago Φ K14 se realiza las pruebas de rango de hospedero, multiplicidad de infección y curva de un paso. Para la caracterización fisicoquímica son las pruebas de estabilidad a diferentes condiciones ambientales (temperatura, pH y sensibilidad al cloroformo) y se realiza la microscopía electrónica. El bacteriófago K14 de Vibrio cholerae es caracterizado microbiológica y fisicoquímicamente de un total de 3 bacteriófagos aislados de aguas residuales es caracterizado microbiológica y fisicoquímicamente. Presenta una multiplicidad de infección (MOI) óptima de 0.001. El periodo latente del fago K14 es de 10 a 15 minutos y el tamaño de explosión de 25 UFP por célula infectada. Es estable a temperaturas de 40 oC, 50 oC y 60 oC e inestable a los 70 oC y 80 oC. El bacteriófago K14 no es sensible al cloroformo. Es inestable a pH 3 y estable del pH 7 a pH 9 pero tiene mayor estabilidad a pH 8. Según la micrografía electrónica el bacteriófago Φ K14 pertenece según sus estructuras a la familia Myoviridae.
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SILVA, Roseli Pimentel Pinheiro e. "Fatores interferentes na frequência da vibriose em camarão marinho cultivado (Litopenaeus vannamei,Boone 1931) no litoral sul de Pernambuco." Universidade Federal Rural de Pernambuco, 2007. http://www.tede2.ufrpe.br:8080/tede2/handle/tede2/6505.
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Considering the illnesses are barriers for the development of the carcinicultura, the vibriose has the possibility to occur for having as etiologic agent bacteria autochtonous of marine environment, it was objectified identification of the interferentes factors in the frequency of this disease. Four situated farms in the south coast of Pernambuco had been selected of which samples of water and shrimp during all had been collected monthly the phases of culture in two different climatic cycles (wet and rainy). Esteem the load of Vibrio spp., samples of water, post larvae had been analyzed, hemolymph and hepatopancreas and the countings had been correlated, through the use of mathematical models (P<0,05), with the variable - physical and chemical of the water, season, microscopical observation, histopathology, presence of toxins and production management methods. With it was observed that only the changeable time of culture intervened with the total counting of Vibrio spp. The counts varying from 0 to 2,9 x 104 in the water, from 0 to 2,1 x 105 in post larvae, from 0,1 x 10 to 1,1 x 105 in hemolymph and from 7,0 x 10 to 1,1 x 106UFC/mL/g in the hepatopancreas. The load of vibrionáceos increases with cycle duration, and it does not suffer influence from the variable physical and chemical of the water, of the handling, of the toxin presence.
Considerando as doenças como barreiras ao desenvolvimento da carcinicultura, a vibriose tem a possibilidade de ocorrer por ter como agente etiológico bactérias autóctones de ambiente marinho, objetivou-se a identificação dos fatores interferentes na freqüência desta enfermidade. Quatro fazendas situadas na costa sul de Pernambuco foram selecionadas das quais foram coletadas mensalmente amostras de água e camarão durante todas as fases de cultivo em dois diferentes ciclos climáticos (estio e chuvoso). Para estimar a carga de Vibrio spp., analisaram-se amostras de água, pós-larva, hemolinfa e hepatopâncreas e as contagens foram correlacionadas, pela utilização de modelos matemáticos (P<0,05), com as variáveis – estação do ano, variáveis físicas e químicas da água, exames a fresco e histopatológico, presença de toxinas e técnicas de manejo empregadas. Observou-se que apenas a variável tempo de cultivo interferiu na contagem total de Vibrio spp. As contagens variaram de 0 a 2,9 x 104 na água, 0 a 2,1 x 105 na pós-larva, 0,1 x 10 a 1,1 x 105 na hemolinfa e 7,0 x 10 a 1,1 x 106UFC/mL/g no hepatopâncreas. A carga de vibrionáceos aumenta com tempo de cultivo, e não sofre influência das variáveis físicas e químicas da água, do manejo e da presença de toxinas.
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Rahmani, Alexandra. "Identification des facteurs de pathogénicité de la bactérie Vibrio tapetis, responsable de la maladie de l'anneau brun chez la palourde japonaise Ruditapes philippinarum et de mortalités chez les poissons marins Transcriptomic analysis of clam extrapallial fluids reveals immunity and cytoskeleton alterations in the first week of Brown Ring Disease development, in Fish & Shellfish Immunology 93, October 2019." Thesis, Brest, 2019. http://www.theses.fr/2019BRES0059.
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L’objectif principal de cette thèse est d’étudier les mécanismes liés au pouvoir pathogène de V. tapetis.Pour cela, nous avons développé 2 axes de recherche. Le premier axe vise à étudier la virulence de V. tapetis en répondant aux 2 problématiques suivantes : Quels sont les gènes impliqués dans la virulence de V. tapetis ? et Existe-t-il des marqueurs hôtes-spécifiques de la virulence de V. tapetis ? Le second axe de recherche concerne l’interaction hôte pathogène et répond aux 2 problématiques suivantes : Quels sont les gènes exprimés lors de l’infection chez l’hôte ? et Quelles sont les modulations au sein de l’animal associées au pH et à la température lors de l’infection ?Les principales découvertes de cette thèse sont : (i) La bactérie V. tapetis, dans le cadre de la MAB, induit une sous expression des gènes impliqués dans la réponseimmunitaire et une dérégulation des gènes impliqués dans la stabilisation et la synthèse des filaments d’actine (ii) Ce pathogène induit également une diminution de l’activité lysosomale sur les hémocytes exposés (iii) L’effet de V. tapetis sur le cytosquelette d’actine et sur la diminution de l’activité lysosomale est indépendante du système de sécrétion de type IV (T4SS) (iv) Le système de sécrétion de type IV (T4SS) est impliqué dans le développement de la MAB mais n’est pas essentiel pour induire cette affection(v) Dans le cadre de la MAB et de la perte des adhérences des hémocytes in vitro, V. tapetis est capable de moduler le pH des fluides extra-palléaux, respectivement dans les premiers jours et premières heures de l’infection (vi) Enfin, l’approche de « strains typing » basée sur la technique MALDI-TOF permet de discriminer les souches de V. tapetis en fonction de leur pouvoir pathogène vis à vis de la palourde japonaiseThe main objective of this thesis is to study the mechanisms related to the pathogenicity of V. tapetis. For this purpose, we developed 2 research axes. The first one aimed at studying the virulence of V. tapetis by answering the following 2 issues: What are the genes involved in the virulence of V. tapetis? and Are there host-specific markers of the virulence of V. tapetis? The second research axis concerned pathogen-host interactions and addressed the following 2 issues: What are the genes expressed during infection in the host? and What are the modulations in the animal associated with pH and temperature during infection? The main findings of this thesis are: (i) V. tapetis, in the context of BRD, induces a down expression of genes involved in the immune response anda deregulation of genes involved in the stabilization and synthesis of actin filaments (ii) This pathogen also induces a decrease in lysosomal activity on exposed hemocytes (iii) The effect of V. tapetis on the actin cytoskeleton and on the decrease in lysosomal activity is independent of the type IV secretion system (T4SS) (iv) The type IV secretion system (T4SS) is involved in the development of BRD but is not essential to induce this disease (v) In the context of BRD and of the loss of hemocyte adhesions properties in vitro, V. tapetis is able to modulate the pH of extrapallial fluids, respectively in the first days and hours of infection (vi) Finally, the "strains typing" approach based on MALDITOF makes it possible to discriminate between V. tapetis strains according to their pathogenicity with regard to Manila clam
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Markman, Caroline Viana. "Caracterização de Vibrio cholerae, V. parahaemolyticus e V. vulnificus em amostras da região costeira do estado de São Paulo, de regiões portuárias brasileiras e de tanques de lastro de navios." Universidade de São Paulo, 2009. http://www.teses.usp.br/teses/disponiveis/42/42132/tde-16072009-132501/.
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A poluição, alteração física do habitat e a introdução de espécies invasoras via água de lastro, representam os maiores impactos antropogênicos para os ambientes costeiros. Foram pesquisadas em amostras da região costeira de S. Paulo, regiões portuárias brasileiras e de tanques de lastro de navios, bactérias das espécies Vibrio cholerae (Vc), V. parahaemolyticus (Vp) e V. vulnificus (Vv) que são as que têm maior implicação na saúde pública. As amostras foram avaliadas levando-se em conta parâmetros físico-químicos e microbiológicos e suas relações com a presença de Vc, Vp e Vv. As relações clonais foram verificadas através das técnicas de ERIC, BOX e REP-PCR. Foram identificadas 90 cepas de Vp e 11 de Vc. Foram observadas correlações entre alguns parâmetros microbiológicos e a presença de vibrios. A análise clonal permitiu verificar a alta diversidade das cepas. Concluiu-se que Vc e Vp são autóctones do ambiente costeiro brasileiro e podem ser tornar reservatórios para determinados fatores associados à virulência, gerando cepas com potencial epidêmico.Pollution, physical alteration of habitat and the introduction of alien species through ballast water constitute the biggest anthropogenic impacts on coastal environments. We examined samples taken from the coastal region of S. Paulo state, Brazilian ports and ship ballast tanks, for bacteria of the species Vibrio cholerae (Vc), V. parahaemolyticus (Vp) and V. vulnificus (Vv) which have the most significant implication for public health. The samples were evaluated for microbiological and physical-chemical parameters as well as the presence of Vc, Vp and Vv. Clonal relationships of bacterial isolates were determined through ERIC, BOX and REP-PCR. A total of 90 strains of Vp and 11 of Vc were identified. Correlations between some microbiological parameters and the presence of vibrios were observed. The clonal analysis revealed extensive strain diversity. We concluded that Vc and Vp are autochthonous bacteria of the Brazilian coastal environment that can become reservoirs for factors associated with virulence, and are capable of generating strains with epidemic potential.
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Gentric, Charline. "La bioremédiation in situ des parcs conchylicoles par les éponges marines est-elle envisageable ?" Thesis, Lorient, 2016. http://www.theses.fr/2016LORIS399/document.
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La préservation de la qualité des eaux marines et la lutte contre les pollutions liées à l'activité humaine sont devenues des enjeux mondiaux. De nombreux contaminants biologiques et polluants chimiques se retrouvent dans l’eau de mer, par conséquent dans les produits aquacoles. Ce contexte fait qu’aujourd’hui, les professionnels de la mer sont à la recherche de solutions pour préserver voire améliorer la qualité de leurs eaux. Au sein de notre biodiversité, les éponges marines sont des animaux capables de filtrer 10 000 fois leur volume en eau par jour et de retenir 80% des particules en suspension comme la matière organique, les minéraux, les bactéries et les virus. Par la même occasion, elles accumulent certains éléments traces métalliques comme le plomb, le cadmium ou le cuivre. En collaboration avec le Comité Régional de Conchyliculture de Bretagne Sud, le projet REMEDBIO dans lequel s’inscrit cette thèse se propose d'exploiter le potentiel de filtration des éponges marines du littoral breton. Les objectifs sont de contrôler le développement de bactéries pathogènes et de réduire la présence de polluants chimiques. L’éponge marine Hymeniacidon perlevis (Demospongiae) a été choisie comme modèle pour cette étude. Après avoir mis en évidence la faisabilité de la culture d’éponges marines sur l’estran, notre travail a montré, lors d’essais in vitro, une diminution de la contamination des huîtres par deux bactéries, Escherichia coli et Vibrio aestuarianus, et par le plomb, un élément trace métallique, en présence d’éponges. La dernière phase de ce travail a consisté à valoriser les résultats obtenus. Le projet d’entreprise LECOMER a débuté par le concours START’UBS (lauréat) proposé par l’Université de Bretagne Sud en 2014. Par la suite, LECOMER a été élu lauréat des Trophées de l’Innovation du Morbihan 2014The conservation of waters quality and the fight against pollution due to human activities havebecome global issues. Many biological contaminants and chemical pollutants are found in sea water, therefore in aquaculture products. This context fact sea professional are looking for solutions to preserve or even improve the quality of their waters. Among marine biodiversity, marine sponges filter 10 000 times their volume of water per day and retain 80 % of suspended particles such as organic matter, minerals, bacteria and viruses. In addition, sponges are therefore considered as bio-accumulators of metallic trace element such as lead, cadmium or copper. In collaboration with the Comité Régional de Conchyliculture de Bretagne Sud, REMEDBIO project proposes to exploite potential of marine sponges of the Brittany coast. One of the main priorities of this project is to reduce the impact of chemicals (heavy metals) and of biological contaminants (bacteria, viruses) on shellfish breeding. The marine sponges Hymeniacidon perlevis (Demospongiae) was chosen as the model for this study. Having demonstrated the feasibility of the culture of marine sponges on the foreshore, our work has shown, when tested in vitro, reduced contamination of oysters by two bacteria, Escherichia coli and Vibrio aestuarianus, and lead, a metal trace element, in the presence of sponges. The last phase of this work has been to enhance the results. The company LECOMER project began with the START'UBS contest (winner) proposed by the Université de Bretagne Sud in 2014. Thereafter, LECOMER was elected winner of the Innovation Awards of Morbihan in 2014
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Vieira, Felipe do Nascimento. "Avaliação do tempo de permanência de lactobacillus B6 no trato intestinal de camarões marinhos (Litopenaeus vannamei) e sua relação com a resposta imunológica." Florianópolis, SC, 2006. http://repositorio.ufsc.br/xmlui/handle/123456789/89070.
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Dissertação (mestrado) - Universidade Federal de Santa Catarina, Centro de Ciências Agrárias. Programa de Pós-Graduação em Aqüicultura.Made available in DSpace on 2012-10-22T16:26:50Z (GMT). No. of bitstreams: 1 235678.pdf: 1625447 bytes, checksum: a242d08d44a3495f4d131a6b707f8f28 (MD5)
Avaliou-se o tempo de atuação da bactéria Lactobacillus B6 na flora bacteriana intestinal de Litopenaeus vannamei. Utilizaram-se dois grupos experimentais, um alimentado com dieta comercial e outro alimentado dieta comercial suplementada com o probiótico Lactobacillus B6. As avaliações iniciaram-se 8 dias após o início do experimento e repetiram-se 2, 4, 6 e 8 dias após a substituição do fornecimento da dieta suplementada com Lactobacillus B6 por dieta comercial. A contagem de bactérias lácticas no trato digestivo dos camarões foi superior no tratamento que foi alimentado com dieta suplementada com Lactobacillus B6 somente até o 4o dia de avaliação. A contagem de vibrios e enterobactérias no trato digestivo dos camarões foi superior no controle em relação ao tratamento probiótico apenas nas avaliações nos dias 0 e 2. Nos dias 0 e 2 e 4, a contagem total de hemócitos (THC) dos tratamentos alimentado com ração suplementada com probiótico e controle 3 horas após a inoculação com solução salina e do tratamento probiótico 3 horas após a inoculação com V. harveyi não diferiram e foram superiores ao controle 3 horas após a inoculação com V. harveyi. Nas avaliações dos dias 6 e 8, os tratamentos probiótico e controle 3 horas após a inoculação com solução salina não apresentaram diferenças quanto a THC que foram superiores a dos tratamentos probiótico e controle 3 horas após a inoculação com Vibrio harveyi. Não foi observada diferença significativa entre os tratamentos quanto à atividade da enzima fenoloxidase. No sexto dia após a substituição da alimentação suplementada com probióticos por dieta comercial, todos os parâmetros avaliados foram semelhantes nos camarões alimentados ou não com dieta suplementada com probióticos, sugerindo que o período de ação da bactéria Lactobacillus B6 no trato digestivo dos camarões é curto.
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Kaakeh, Mohamed Riad. "Espèces bactériennes pathogènes et potentiellement pathogènes appartenant au genre vibrio, leur importance dans l'environnement marin méditerranéen et produits dérivés destinés à l'alimentation." Montpellier 1, 1986. http://www.theses.fr/1986MON13516.
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Orozco, Moreyra Rita Esther. "Asociación de las poblaciones de vibrio con las mareas rojas en el litoral peruano." Master's thesis, Universidad Nacional Mayor de San Marcos, 2015. https://hdl.handle.net/20.500.12672/9152.
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Publicación a texto completo no autorizada por el autorLa incidencia de las mareas rojas y la presencia de las especies de vibrios durante la ocurrencia de estos eventos constituyen una amenaza al desarrollo de la maricultura y a los bancos naturales de recursos bentónicos, sobre todo en las áreas someras. En el litoral peruano, las mareas rojas ocurren de manera recurrente durante la primavera y verano, y su tiempo de permanencia está sujeto a los cambios de las condiciones ambientales. Durante estos eventos se presentan algunas especies de Vibrio sp. con características patogénicas y toxigénicas que afectan a los organismos acuáticos y la salud humana, por lo que durante 2010 y 2012 se estudió la distribución temporal y espacial de vibrios marinos durante los eventos de mareas rojas en las bahías de Sechura, Callao, Pisco y San Nicolás-Marcona; esta última, considerada como control, porque son escasos los reportes de mareas rojas. Se observaron densidades bajas (<106 cel/L) de organismos que causan mareas rojas nocivas. El dinoflagelado Akashiwo sanguinea y el ciliado Mesodinium rubrum fueron observados en la zona del Callao; Akashiwo sanguinea, Mesodinium rubrum y Prorocentrum minimum, en Pisco; la diatomea Pseudo-nitzchia pungens y el dinoflagelado Dinophysis rotundata, en Sechura. También se observó la predominancia de la especie cosmopolita Vibrio alginolyticus en todas las áreas. En menor número, las especies V. vulnificus y V. parahaemolyticus en Pisco y Callao asociadas a temperaturas cálidas; estas últimas son conocidas por ser patógenas y provocar severas intoxicaciones en los seres humanos, por el consumo de mariscos o pescado crudos. El índice de correlación R varió entre 0,5 y 0,6, lo que indica la relación significativa entre mareas rojas, Vibrio sp. y factores ambientales.
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DANTAS, Danielli Matias de Macêdo. "Desempenho do camarão marinho Litopenaeus vannamei (Boone,1931) cultivado com uso de probióticos quando submetido à infecção com Vibrio harveyi." Universidade Federal Rural de Pernambuco, 2008. http://www.tede2.ufrpe.br:8080/tede2/handle/tede2/6264.
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The fast expansion of farmed shrimp industry during the last decades has been offering high profitable deal to many countries. However, diseases appearing have caused lots of serious economic damage on productive sector. The effect of probiotic in Litopenaeus vannamei juveniles when submitted to the infection by Vibrio harveyi was evaluated in the present study The exposure to V. harveyi was carried out during 15 days using individuals reared for one month in a closed recirculation system with a commercial probiotic (Bacillus sp.) added to water and food (PAR), only in the water (PA), only in food (PR) and without probiotic (SP). Were examined the responses of food consumption, total concentration of hemocytes, growth and survival. The food consumption did not differ significantly among the treatments, but in the SP treatment a significant reduction occurred in the second week. The PAR and PA treatments showed inferior and more constants values in the total hemocits concentrations during the experimental period. The highest growth rates were observed in the PAR (0.34 ± 0.19 g/week) and SP (0.45 ± 0.04 g/week) treatments, but did not differ statistically within these treatments. Shrimp survival values were higher than 98% in all treatments. The results suggest that the addition of Bacillus sp. to the water or food separately, could increase the food consumption during a longer period of time in shrimp infected by V. harveyi and interfere positively in the immune response of L. vannamei.
A rápida expansão da indústria do camarão na aqüicultura durante poucas décadas tem proporcionado a muitos países altos rendimentos. Entretanto, o surgimento de doenças tem causado sérios prejuízos econômicos ao setor produtivo. Este trabalho verificou o efeito do uso de probiótico no cultivo de juvenis de Litopenaeus vannamei quando submetidos à infecção ao Vibrio harveyi. A exposição ao V. harveyi foi realizada durante 15 dias nos camarões provenientes de um cultivo de 30 dias em sistema fechado sem renovação de água com utilização de um probiótico comercial (Bacillus sp.) adicionado na água e na ração (PAR), somente na água (PA), somente na ração (PR) e sem adição de probiótico (SP). Foram analisadas as respostas de consumo alimentar, concentração total de hemócitos, crescimento e sobrevivência. A análise do consumo alimentar dos camarões não mostrou diferença significativa entre os tratamentos, sendo a única exceção o tratamento SP onde ocorreu uma redução no consumo na segunda semana. Os tratamentos PAR e PA apresentaram valores menores e mais constantes de concentração total de hemócitos durante o período do experimento. As maiores taxas de crescimento foram verificadas nos tratamentos PAR (0,34 ± 0,19 g/semana) e SP (0,45 ± 0,04 g/semana), os quais não diferiram estatisticamente entre si. Os camarões apresentaram valores de sobrevivência acima de 98% em todos os tratamentos. Os resultados sugerem que a utilização do Bacillus sp. adicionados na água ou na ração separadamente, aumentam o consumo alimentar por um maior período de tempo em camarões infectados pelo V. harveyi e interferem positivamente na resposta imune de L.vannamei.
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SILVA, Emanuell Felipe Beserra da. "Utilização de probiótico (Bacillus spp.) na larvicultura do camarão marinho Litopenaeus vannamei." Universidade Federal Rural de Pernambuco, 2010. http://www.tede2.ufrpe.br:8080/tede2/handle/tede2/6292.
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Emanuell Felipe Beserra da Silva.pdf: 411741 bytes, checksum: bc52ae73b30a1e2f1b60236283006192 (MD5)Made available in DSpace on 2017-02-10T13:14:13Z (GMT). No. of bitstreams: 1 Emanuell Felipe Beserra da Silva.pdf: 411741 bytes, checksum: bc52ae73b30a1e2f1b60236283006192 (MD5) Previous issue date: 2010-02-10
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES
This dissertation consisted of two studies and was divided into two papers, the first evaluated the influence of the addition of probiotic Bacillus spp. in the larviculture of white shrimp Litopenaeus vannamei, while the second compared the use of probiotic and antibiotic in the postlarvae culture of the species. For the first study, three experiments were performed: (I) Nauplios4-5 to Zoea3, where they were exposed to probiotic through water (Pw), microalgae (Pm), water and microalgae (Pwm) and control without probiotic (C); (II) Mysis1 to Mysis3, exposed to probiotic through the water (Pw), Artemia (Pa), water and Artemia (Pwa) and control (C) and (III) PL1 to PL10,subject to the same treatments of experiment II. The water quality parameters showed no significant differences among treatments of each experiment. In general, the weight and survival of shrimp in the treatments with probiotic were significantly higher compared with controls in experiments I and II, but this difference was not observed among treatments of experiment III. The concentration of Vibrio spp. both in the water and postlarvae in experiment III was significantly higher in control compared with treatments with the use of probiotic. Already in experiments I and II, the concentration of Vibrio spp. in the water did not differ among treatments, however, Mysis3 larvae treated with probiotic had a lower concentration of Vibrio spp. compared with the control. In the second study, postlarvae (PL1 to PL10) were cultured in three treatments, corresponding to a biological treatment (TB), which was added probiotic Bacillus spp., chemical treatment (TQ) with the addition of antibiotic (erythromycin) and a control (TC), without both products in the culture water. The water quality parameters, as well as the zootechnical performance of postlarvae (weight, total length and survival) did not differ among treatments. However, the final concentrations of Vibrio spp. both in the culture water and postlarvae were significantly reduced with the use of probiotic (TB) in relation to other treatments. Based on the results obtained in the two studies, suggested that the use of probiotic Bacillus spp. in the larviculture of shrimp L. vannamei can provide an increase in the growth and survival of animals, but mainly provides a reduction in the concentration of Vibrio spp. in the culture system. Furthermore, the use of probiotic has great potential to replace the use of antibiotic in the culture of L. vannamei postlarvae.
A presente dissertação foi composta por dois estudos e dividida em dois artigos científicos, o primeiro avaliou a influência da adição do probiótico Bacillus spp. na larvicultura do camarão branco Litopenaeus vannamei, enquanto o segundo comparou a utilização de probiótico e antibiótico no cultivo de pós-larvas da espécie. Para o primeiro estudo, foram realizados três experimentos: (I) Nauplios4-5 a Zoea3, onde foram expostos ao probiótico através da água (Pw), microalga (Pm), água e microalga (Pwm) e controle sem probiótico (C); (II) Mísis1 a Mísis3, expostos ao probiótico através da água (Pw), Artemia (Pa), água e Artemia (Pwa) e controle (C) e (III) PL1 a PL10, submetidos aos mesmos tratamentos do experimento II. Os parâmetros de qualidade de água não apresentaram diferenças significativas entre os tratamentos de cada experimento. Em geral, o peso e sobrevivência dos camarões nos tratamentos com probiótico foram significativamente superiores em comparação aos controles nos experimentos I e II, porém esta diferença não foi observada entre os tratamentos do experimento III. A concentração de Vibrio spp. tanto na água quanto nas pós-larvas no experimento III foi significativamente maior no controle comparado com os tratamentos com uso de probiótico. Já nos experimentos I e II, a concentração de Vibrio spp. na água não diferiu entre os tratamentos, entretanto, as larvas Mísis3 tratadas com probiótico apresentaramu ma menor concentração de Vibrio spp. comparadas com o controle. No segundo estudo, póslarvas (PL1 a PL10) foram cultivadas em três tratamentos, correspondendo a um tratamento biológico (TB), onde foi adicionado probiótico Bacillus spp., tratamento químico (TQ), com adição de antibiótico (eritromicina) e um tratamento controle (TC), sem ambos os produtos na água de cultivo. Os parâmetros de qualidade de água, assim como o desempenho zootécnico das pós-larvas (peso, comprimento total e sobrevivência) não diferiram entre os tratamentos.Entretanto, as concentrações finais de Vibrio spp. tanto na água de cultivo como nas póslarvas foram reduzidas significativamente com a utilização de probiótico (TB) em relação aos outros tratamentos. Com base nos resultados obtidos nos dois estudos, sugere-se que o uso do probiótico Bacillus spp. na larvicultura do camarão L. vannamei pode proporcionar um incremento no crescimento e sobrevivência dos animais, mas principalmente possibilita uma redução na concentração de Vibrio spp. no sistema de cultivo. Além disso, o emprego do probiótico tem grande potencial para substituir o uso de antibiótico no cultivo de pós-larvas de L. vannamei.
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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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Joanna Dourado.pdf: 721470 bytes, checksum: 1ade18b6e4af854fcb0abb1162f7c2bb (MD5)Made available in DSpace on 2016-10-13T12:20:42Z (GMT). No. of bitstreams: 1 Joanna Dourado.pdf: 721470 bytes, checksum: 1ade18b6e4af854fcb0abb1162f7c2bb (MD5) Previous issue date: 2009-02-13
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.
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Dana, Maxime. "Développement de modèles vibro-acoustiques pour prédire le champ proche d’une coque cylindrique raidie munie de revêtements acoustiques." Thesis, Lyon, 2019. http://www.theses.fr/2019LYSEI011.
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Les antennes SONAR sont utilisées en lutte sous-marine pour la détection acoustique des navires adverses. Leurs performances dépendent de la capacité de l'antenne et de son traitement par formation de voies à faire ressortir le signal à détecter, et à sa capacité à s'affranchir du bruit de fond environnant après traitement. On cherchera à développer des modèles vibro-acoustiques simulant la réponse en signal au niveau des capteurs d'une antenne de flanc fixée sur la coque résistante du bâtiment. Ces modèles devront prendre en compte des revêtements viscoélastiques fixés sur la coque d'acier et permettre la simulation des réponses en signal sur une large plage fréquentielle. Deux modèles robustes numériquement sont développés, permettant la gestion d'un nombre arbitraire de couches solides élastiques homogènes ou de couches fluides intermédiaires. Les deux modèles assemblent la structure multicouche par un système matriciel global, tenant compte du couplage avec les fluides interne (l'air) et externe (l'eau). Une attention particulière est portée sur le contournement des problèmes numériques rencontrés lors des développements. Par ailleurs, les raidisseurs internes destinés à renforcer la structure sont des inhomogénéités locales suivant l'axe de la coque introduisant des dispersions sur la réponse en signal des capteurs en fonction de leur position. Leur influence est prise en compte en considérant un réseau périodiquement espacé, et la dynamique de chaque renfort sera modélisée par un modèle coque mince sous éléments finis. Un formalisme spectral développé lors de l'étude permet le couplage de la structure multicouche avec le réseau périodique de renforts internes. Les modèles sont validés à partir de comparaisons croisées avec des simulations éléments finis très coûteuses en ressources informatiques. Les résultats obtenus sur des configurations réalistes de sous-marins, en présence ou non du réseau de raidisseurs, montrent leur intérêt pour appréhender la réponse en signal des antennes de flancSONAR antennas are used in submarine warfare for acoustic detection of enemy ships. Their performance depends on the capacity of the antenna processing to bring out the signal to be detected, and its ability to overcome the surrounding background noise after treatment. Vibro-acoustic models will be developed to simulate the signal response at the sensors of a flank antenna attached to the submarine shell. These models will have to take into account viscoelastic coatings fixed on the steel hull and allow the simulation of the signal response over a wide frequency range. Two numerically robust models are developed, allowing the management of an arbitrary number of homogeneous elastic solid layers or intermediate fluid layers. Both models assemble the multilayered structure by a global matrix system, taking into account the coupling with internal (air) and external (water) fluids. Particular attention is paid to the circumvention of the numerical problems encountered during the developments. Furthermore, the internal stiffeners intended to reinforce the structure are local inhomogeneities along the axis of the shell which introduce dispersions on the signal response of the sensors as a function of their relative position. Their influence is taken into account by considering a periodic spacing, and the dynamics of each stiffener will be modeled by a thin shell model under finite elements. A spectral formalism developed during the study allows the coupling of the multilayered structure with the periodic stiffeners array. The models are validated from cross-validation with finite element simulations that are very expensive in computing resources. The results obtained on realistic configurations of submarines, with or without the network of stiffeners, show their interest in understanding the signal response of flank antennas
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Dumontet, Stefano. "Marine aquatic environment as a source of potential human pathogens : studies on prevalence, ecology and characterisation of Aeromonas spp. and Vibrio vulnificus isolated from marine environment /." Uppsala : Dept. of Veterinary Microbiology, Swedish Univ. of Agricultural Sciences ([Institutionen för veterinärmedicinsk mikrobiologi], Sveriges lantbruksuniv.), 2002. http://epsilon.slu.se/avh/2002/91-576-6370-X.pdf.
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Scherrer, Roch. "Analyse du comportement vibro-acoustique de structures immergées excitées par des sources transitoires." Thesis, Lyon, INSA, 2015. http://www.theses.fr/2015ISAL0037/document.
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Dans le cadre de la lutte en mer, la détection acoustique des structures immergées s’effectue généralement sur des signaux stationnaires. Une nouvelle génération de sonars permet de détecter sur des signaux transitoires. Ceci implique de compléter le processus de conception des projets industriels qui ne tient compte d’exigences qu'en matière de bruits rayonnés en régime stationnaire. Il est donc nécessaire de comprendre les mécanismes de transfert des sources de bruit transitoires sur les structures immergées. Cette thèse s’inscrit dans ce cadre et consiste à étudier les mécanismes de transfert vibratoire et de rayonnement acoustique qui peuvent intervenir sur ces structures lorsque l’excitation est transitoire. L’analyse porte sur différents éléments de la chaine de transfert : le rayonnement dans l’eau du bordé, la diffraction des ondes par les raidisseurs, et le comportement résonnant des structures internes supportant les matériels. Le premier chapitre présente une analyse bibliographique autour de l’étude des phénomènes vibroacoustiques transitoires des structures immergées, de l’influence d’un fluide lourd sur le comportement vibroacoustique des plaques, et des méthodes de calcul vibroacoustiques en régime transitoire. Dans le second chapitre nous étudions la réponse transitoire d’une plaque infinie immergée soumise à une force impulsionnelle ponctuelle. La méthode de calcul s’appuie sur les calculs spectraux fréquences-nombre d’onde. Les réponses temporelles sont obtenues par transformées de Fourier inverses. L’analyse des spectres et des réponses temporelles de l’accélération vibratoire de la plaque et de la pression rayonnée, met en évidence l’influence de la présence du fluide. La prise en compte de l’inertie rotationnelle et du cisaillement à travers le modèle de plaque de Mindlin-Timoshenko est également étudiée. Ces résultats sont confrontés à une expérimentation présentée dans le troisième chapitre. La structure étudiée est une plaque rectangulaire posée horizontalement à la surface d’une cuve remplie d’eau. Deux types de sources transitoires sont utilisés : marteau de choc, lâché d’une bille. La comparaison des résultats numériques et expérimentaux montre que l’on retrouve certains phénomènes évoqués précédemment. L’effet des raidisseurs sur le rayonnement acoustique fait l’objet du quatrième chapitre. Une plaque raidie périodiquement dans une direction est considéré. L’influence des ondes de Bloch-Floquet sur la réponse temporelle est étudiée. Les résultats sont comparés à des mesures effectuées sur une barge d’essais. Dans le cinquième chapitre, l’effet des structures internes est étudié à partir d’un modèle de plaque couplé à un système résonnant constitué d’un assemblage poutre-plaque. La méthode des inertances est utilisée pour obtenir les forces de couplage entre les différents éléments. Les signaux temporels sont étudiés en fonction de l’importance de la rupture d’inertance entre la plaque et l’assemblageIn the sea, the acoustic detection of other battle engines is done by detecting mostly stationary signals. However, new types of detection systems are being developed, and are able to detect and to analyze transient signals. Therefore, the industrial conception process needs to be improved, so that the underwater vehicles transient noises can be taken in account. In order to do so, the mechanism of vibroacoustic transfer of transient sources of submerged structures has to be understood. The object of this thesis is then the study of the mechanism of vibration transfer and acoustic radiation of those structures when they are excited by transient sources. The shell radiation in the water, the wave diffraction by circumferential stiffeners and the resonant behavior of internal substructures are analyzed. The first chapter presents the bibliographical study of three themes: the study of transient phenomenon of submerged structures, the influence of heavy fluid coupling on vibroacoustic behavior of plates, and the different calculation methods in transient vibroacoustics. In the second chapter, we study the transient response of a submerged infinite plate excited by an impulsively point force. First, the calculations are done in the wavenumber-frequency domain. Then the spatio-temporal responses are obtained using inverse Fourier transforms. The discretization of wavenumber and frequency domains and the damping model are studied. The analysis of frequency and time responses of the plate vibration and the radiated pressure enable us to observe the influence of heavy fluid coupling. Besides the Mindlin-Timoshenko plate model is also used and the effect of rotation inertia and shear stress are studied. In the third chapter, these numerical results are confronted to experimental data, obtained experimentally. The studied structure is a rectangular plate lying on the surface of a water tank. Two different excitations are used: an impact hammer and the free fall of a steel ball. The study of the correlation between numerical and experimental results showed that some phenomena are observed in both cases. The influence of stiffeners on the acoustic radiation is the theme of the fourth chapter. An infinite plate which is periodically stiffened through one direction is considered. The effect of Bloch-Floquet waves on time response is studied. Numerical results are compared to measurements data obtained on an industrial submerged structure. In the fifth chapter, the effect of internal structures is analyzed by modelling an infinite plate coupled to a resonant system made of a beam and a rectangular finite plate. The inertance coupling method is used to obtain the coupling forces between the different substructures. Influence of inertance difference between the substructures is illustrated by the time signals
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ALVES, Carlos André Bezerra. "Fatores interferentes na ocorrência das vibrioses em camarão marinho cultivado (Litopenaeus vannamei, Boone 1931) no litoral do estado de Pernambuco." Universidade Federal Rural de Pernambuco, 2007. http://www.tede2.ufrpe.br:8080/tede2/handle/tede2/5292.
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Carlos Andre Bezerra Alves.pdf: 107646 bytes, checksum: c97f6b2e6468643c3953a5613da56559 (MD5)Made available in DSpace on 2016-08-11T16:51:11Z (GMT). No. of bitstreams: 1 Carlos Andre Bezerra Alves.pdf: 107646 bytes, checksum: c97f6b2e6468643c3953a5613da56559 (MD5) Previous issue date: 2007-03-22
Conselho Nacional de Pesquisa e Desenvolvimento Científico e Tecnológico - CNPq
Diseases means any adverse alteration in the health or acting in the productivity of the animals. In shrimps, the diseases can be unchained when it occur an unbalance potentially among the environmental conditions of nurseries, the health condition of the cultivated shrimps and the pathogenic agents, associated with the employed handling. This way, it was aimed at to evaluate the sanitary conditions and to determine which the relevant factors in the attack of the vibrioses in shrimp cultivated Litopenaeus vannamei. In the period of December of 2005 to November of 2006, were collected and analyzed shrimp samples, water and nursery soil, as well as technical information on the handling adopted in a commercial shrimp culture located in the north of Pernambuco/ Brazil. The handling parameters were correlated through mathematical models (P <0,05) with the other data of the research. Concerning bacteriology, the shrimps and the water they were examined as for the vibrios load. In the same time, took place exams to fresh in the shrimps for verification of lesions macro and microscopic formerly present and, seeking the confirmation of the presence or necrosis absence. All of the analyses were accomplished at laboratories of the Rural Federal University of Pernambuco (UFRPE). It was verified in the exam to cool air that as larger the level of detected pathological alterations and as larger the vibrios number in the water, smaller the vibrio number in the shrimps. Regarding the muscular necrosis, researched in the histopathology analyses, it was observed that as larger the number of lesions, larger the vibrios number. About the variables limnologica of the water, as larger at the concentrations of phosphate and the levels of salinity of the water, larger and smaller, respectively, the number of Vibrio spp.. In the analyses of oxygen, when larger levels were detected in the water, minor was the vibrios number detected in the shrimps. The species of isolated vibrio in the water of the ponds and in the shrimps, environmental or pathogenic, cause diseases in the animals when detected high countings that the physical and chemical parameters of the water and of the soil, they interfered on the vibriose occurrence and that relationship doesn't exist among the number of alterations observers in the exam to fresh with the vibrios number in the water of the ponds and in the shrimp.
Enfermidade significa qualquer alteração adversa na saúde ou desempenho na produtividade dos animais. Em camarões, as moléstias podem ser desencadeadas quando ocorre um desequilíbrio entre as condições ambientais de viveiros, o estado de saúde dos camarões cultivados e os agentes potencialmente patogênicos, associado com o manejo empregado. Desta forma, objetivou-se avaliar as condições sanitárias e determinar quais os fatores relevantes no acometimento das vibrioses em camarões Litopenaeus vannamei cultivados. No período de dezembro de 2005 a novembro de 2006, foram coletadas e analisadas amostras de camarão, água e solo de viveiro, assim como informações técnicas sobre o manejo adotado em uma carcinicultura comercial situada no litoral norte de Pernambuco. Os parâmetros de manejo foram correlacionados através de modelos matemáticos (P < 0,05) com os demais dados da pesquisa. No tocante a bacteriologia, os camarões e a água foram examinados quanto à carga de vibrios. Concomitantemente, realizaram-se exames a fresco nos camarões para verificação de lesões macro e microscópicas outrora presente e exames histopatológicos, visando a confirmação da presença ou ausência de necrose. Todas as análises foram realizadas em laboratórios da Universidade Federal Rural de Pernambuco (UFRPE). Constatou-se no exame a fresco que quanto maior o nível de alterações patológicas detectadas e quanto maior o número de vibrios na água, menor o número de vibrio nos camarões. Com relação à necrose muscular, pesquisada no exame histopatológico, observou-se que quanto maior o número de lesões maior o número de vibrios. Em relação as variáveis limnológicas da água, quanto maiores às concentrações de fosfato e os níveis de salinidade da água, maior e menor, respectivamente, o número de Vibrio spp.. No tocante as análises de oxigênio, quando foram detectados maiores níveis na água, menor foi o número de vibrios detectado nos camarões. Conclui-se que as espécies de vibrio isoladas na água dos viveiros e nos camarões, tanto ambientais quanto patogênicas, foram capazes de causar doenças nos animais quando detectadas altas contagens que os parâmetros físicos e químicos da água e do solo interferiram sobre a ocorrência de vibriose e que não existe relação entre o número de alterações observgadas no exame a fresco com o número de vibrios na água dos viveiros e no camarão.
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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.
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En France, les sites ostréicoles de la méditerranée sont confrontés régulièrement à de fortes mortalités de juvéniles de Crassostrea gigas mais également à des efflorescences récurrentes du dinoflagellé producteur de toxines paralysantes (PSTs), Alexandrium catenella. Parmi les pathogènes associés de manière récurrente à ces mortalités, on retrouve des souches de Vibrio appartenant au clade Splendidus. Nous nous intéressons ici aux interactions entre A. catenella et l’huître C. gigas confrontée à des vibrios pathogènes. Dans une première partie, nous avons montré qu'en conditions expérimentales contrôlées, A. catenella augmentait la sensibilité de l’huître C. gigas au pathogène Vibrio tasmaniensis LGP32. In situ, nous avons également constaté la coïncidence entre la mortalité des huîtres en 2014 et la présence des PSTs dans leurs tissus. Dans une seconde partie, nous avons étudié les interactions entre les PSTs produites par A. catenella et les cellules immunitaires de l’huître, les hémocytes. Un résultat important de cette thèse a été de montrer que la saxitoxine, une des toxines produites par A. catenella, se lie à des structures granulaires présentes dans le cytoplasme des hémocytes de C. gigas et induit une mort hémocytaire caspases-dépendante. Cette mort est indépendante de la production d’espèces réactives de l’oxygène. Nous avons également démontré que la toxine majoritaire des cellules d’A. catenella, la gonyautoxine 5, est la plus toxique sur les hémocytes de C. gigas. Parmi les populations hémocytaires touchées, les hyalinocytes sont très sensibles à ce stress toxique. Les hémocytes étant les cellules immunocompétentes de l’huître qui jouent le rôle central dans la défense contre les infections, nous supposons que leur mort cellulaire induite par les PSTs affecte négativement la défense des mollusques bivalves et explique l'augmentation de la susceptibilité des huîtres à l'infection par Vibrio tasmaniensis LGP32 quand elles sont exposées à A. catenellaIn 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
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Graça, Eva Lúcia Martins. "Immune responses in Bathymodiolus azoricus upon Vibrio challenges : approaches to characterize mussel survival strategies and physiological adaptations in deep sea extreme environments." Doctoral thesis, 2015. http://hdl.handle.net/10400.3/3674.
Full textAbstract:
Tese de Doutoramento, Ciências do Mar, especialidade de Biologia Marinha, 18 de Dezembro de 2015, Universidade dos Açores.O ambiente marinho profundo representa uma excelente fonte de investigação para desenvolver e melhorar os conhecimentos sobre os animais que habitam em ambientes extremos e sobre as relações quimiossintéticas estabelecidas nesse ecossistema marinho. Dessa premissa surge a necessidade de entender o funcionamento do sistema imunitário em animais do fundo marinho, nomeadamente do mexilhão do mar profundo Bathymodiolus azoricus. O facto de este mexilhão habitar e desenvolver-se em ambientes extremos, como as fontes hidrotermais marinhas de profundidade, torna-o num interessante modelo para caracterizar as suas estratégias de sobrevivência e adaptações fisiológicas nesses ambientes. Nestas fontes hidrotermais, o seu sistema imunitário está constantemente a ser desafiado por compostos estranhos e microrganismos, como as bactérias do meio ambiente circundante. Contudo, as respostas imunitárias no B. azoricus após contacto com Vibrio não estão completamente compreendidas. As bactérias do género Vibrio são frequentemente patogénicos marinhos que causam grande mortalidade em bivalves. Assim, a presente tese pretende compreender as respostas imunitárias dos mexilhões após a exposição a diferentes estirpes de Vibrio, de modo a elucidar as principais vias de sinalização dos genes e proteínas intervenientes na defesa dos mexilhões durante um determinado estímulo bacteriano. Neste sentido, os métodos apresentados nesta tese têm como base a utilização de diferentes técnicas da biologia molecular, com destaque para o PCR quantitativo em tempo real baseado no princípio da reacção em cadeia da polimerase. Esta técnica foi realizada: em brânquia de mexilhões B. azoricus submetidos ao contacto com diferentes suspensões bacterianas de patogénicos marinhos (Capítulos I); no estudo comparativo da expressão de genes e proteínas entre o mexilhão de profundidade B. azoricus e o mexilhão costeiro Mytilus galloprovincialis (Capitulo II) e no estudo sobre a especificidade da resposta imunitária em diferentes tecidos, entre populações de B. azoricus provenientes das fontes hidrotermais Menez Gwen e Lucky Strike, após contacto com a bactéria Vibrio diabolicus (Capitulo III). [...].
ABSTRACT: The deep-sea environment is excellent source for investigating and improving our knowledge in the field of marine biology of organisms living in extreme habitats and their relationships with chemosynthetic-based ecosystems. Along with the study of chemosynthetic-based ecosystems the necessity to understand immune system function in deep-sea hydrothermal animals such as in the mussel Bathymodiolus azoricus, has emerged gradually. Indeed, these mussels live and thrive in extreme environments as the deep-sea hydrothermal vents. B. azoricus species has become an interesting model to characterize the survival strategies and physiological adaptations in these environments. At such depths and under hydrothermal physico-chemical conditions, their immune system is constantly challenged by foreign vent compounds and microorganisms (e.g. bacteria). However, these immune responses in B. azoricus upon Vibrio challenges are not thoroughly understood. Vibrio bacteria are frequently pathogens in the aquatic environment that cause a high mortality in bivalves. This thesis was conceived and achieved with the aim of better understanding the immune response in B. azoricus mussels after several experimental challenges with different Vibrio strains. The core of this thesis consisted of elucidating signaling gene pathways and proteins involved in mussel defenses during bacterial stimuli. In this way, the thesis methods were undertaken using several molecular biology techniques, highlighting the qPCR. This technique was used: in gills from B. azoricus mussels infected with suspension of different marine bacterial pathogens (Chapter I); in comparative studies of gene expression and protein analyses between deep-sea hydrothermal vent mussel B. azoricus and the shallow-water mussel Mytilus galloprovincialis (Chapter II) and in an immune response tissue-specificity study in different tissues, and between Menez Gwen and Lucky Strike B. azoricus populations, after exposure to Vibrio diabolicus bacterium (Chapter III). [...]
This thesis was supported by FCT grant SFRH/BD/68951/2010, Department of Oceanography and Fisheries, University of the Azores and Institute of Marine Research (IMAR).
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Calik, Hakan. "Effect of high pressure processing on the survival of Vibrio parahaemolyticus strains in pure culture and Pacific oysters." Thesis, 2001. http://hdl.handle.net/1957/26567.
Full textAbstract:
Different strains of Vibrio parahaemolyticus (Vp) in broth cultures and Vp-inoculated
live Pacific oysters (Crassostrea gigas) were subjected to high pressure
processing (HPP) at 241, 276, 310, and 345 MPa. Results showed Vp numbers
were reduced by HPP in both pure culture and whole oysters. Vp inactivation was
dependent on time and pressure. Optimum conditions for reducing Vp in pure
culture and oysters to non-detectable levels were achieved at 345 MPa for 30 and
90 s, respectively. Resistance variations were detected between Vp in pure culture
and in oysters. HPP proved to be an efficient means of reducing Vp in oysters.
The decimal reduction rates of Vp 03:K6 strain was compared with clinical
ATCC 17802 and environmental AST Vp strains in pure culture and Pacific oysters
under high pressure processing (HPP) at 276 and 310 MPa for different treatment
times based on Calik and others (2001) data. Results showed that 03:K6 strain had
relatively higher decimal reduction rates when compared to two other strains. The
03:K6 strain in oyster had the highest D-value of 1.77 min under 276 MPa HPP
treatment. Reduction trends presented by Vp 03:K6 strain must be considered
when making commercial HPP setting decisions for reduction of Vp.Graduation date: 2002
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Shikongo-Nambabi, Martha Naita Namwaala Nangulohi. "Occurrence and control of Vibrio species as contaminants of processed marine fish." Thesis, 2011. http://hdl.handle.net/2263/28853.
Full textAbstract:
Marine water contains large numbers of fish spoilage bacteria and pathogens including V. cholerae, V. parahaemolyticus, and V. vulnificus. Consumption of contaminated seafood could lead to the transmission of these pathogens to humans. Accurate identification of suspected pathogens and spoilage organisms is important to ensure consumer safety and a long shelf life. This project assessed the bacterial quality of hake during processing. Some attention was also given to pilchards and horse mackerel. The results showed a sharp increase in the mesophilic and sucrose fermenting Vibrio species counts in hake after filleting. It has been suggested that this contamination occurred during processing from biofilms present in the sea-water distribution system. During the study 257 strains isolated from Thiosulphate citrate bile salts sucrose (TCBS) agar were screened to determine the presence of the pathogenic Vibrios amongst these isolates. It was difficult to distinguish between V. alginolyticus and V. parahaemolyticus species due to high sequence similarity in their 16S rRNA genes. Final identification of the isolates required a polyphasic approach and it was found that none of the pathogenic Vibrios were present but that the Vibrio isolates mainly belonged to V. alginolyticus. As it was suspected that the main source of contamination was the treated sea water used during processing the ability of chlorine, ozone and hydrogen peroxide to prevent biolfilm formation was examined. The behaviour of two V. alginolyticus strains (V590 and V595) isolated from the processed hake was evaluated. These strains formed biofilms faster than the V. alginolyticus LMG4409 type strain, but were similar to V. parahaemolyticus LMG2850. Biofilms formed by these bacteria were resistant to 4 mg/l chlorine and to 2 mg/l ozone, but were inhibited by 0.05 % and 0.2 % hydrogen peroxide for biofilms initiation and mature biofilms respectively. The close resemblance of atypical V. alginolyticus isolates to V. parahaemolyticus may indicate the ability of pathogens to survive under similar conditions. Effective decontamination and quality assurance strategies are therefore required when processing fish to prevent disease outbreaks.Thesis (PhD)--University of Pretoria, 2011.
Microbiology and Plant Pathology
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