The chicken yolk sac and small intestine are connected through the yolk stalk and share many biological similarities. During the embryonic stage, the extra-embryonic yolk sac helps the embryo to absorb nutrients primarily in the last two weeks of incubation. The chicken yolk sac physically moves yolk contents from the yolk sac to the small intestine at the end of embryogenesis. This is the time when the small intestine replaces the yolk sac in assimilating nutrients for the embryo and later for the posthatch chicken. Additionally, both chicken small intestinal epithelia and the yolk sac secrete beta defensins for promoting intestinal health. Since there are heterogeneous cell types along the mammalian intestinal villus, which are derived from the intestinal stem cells in the crypts, we investigated if cells of the chicken yolk sac and small intestine have the same ontogeny as mammalian intestinal epithelial cells. In this dissertation, we mainly focused on the spatial expression of nutrient transporters (PepT1 and SGLT1), intestinal stem cell markers (Lgr5 and Olfm4), and avian beta defensins in the chicken yolk sac and small intestine during the embryonic and early posthatch stages. RNAscope in situ hybridization was used to identify the distribution of cells expressing PepT1 mRNA in both the chicken yolk sac and small intestine. PepT1 mRNA was found to be expressed by epithelial cells in both the yolk sac and small intestine. In the yolk sac, PepT1 mRNA was uniformly distributed in each endodermal epithelial cell along the villus-like structure. The pattern of PepT1 mRNA expression observed in the chicken yolk sac during the last 10 days of incubation revealed that PepT1 mRNA was increased from e11 to e13, and decreased from e15 to day of hatch. The peak of PepT1 mRNA expression was between e13 and e15, when the yolk sac reaches maximum absorptive area and the growth of the chicken embryo is at its fastest rate. However, the expression of PepT1 mRNA in the intestine was only detected in columnar enterocytes along the villus and not in goblet cells or cells in the crypts. The immunofluorescence assay confirmed that PepT1 protein was located at the brush border membrane of the enterocytes and that protein expression of PepT1 was restricted to the intestinal epithelial cells from approximately the middle to the tip of the villus. In order to identify intestinal stem cells, we used the known mammalian stem cell markers, Lgr5 and Olfm4. Both Lgr5 and Olfm4 are specifically expressed by cells in the chicken intestinal crypts, suggesting that they can be used as biomarkers for chicken intestinal stem cells. Dual labelling of PepT1 and Olfm4 mRNA on the same chicken intestinal sample revealed that there was a gap between PepT1-expressing enterocytes and Olfm4-expressing intestinal stem cells. The cells in this gap were presumably transit amplifying (TA) cells. Additionally, we also found that the TA cell zone along the intestinal villus was reduced during chicken growth. This TA cell population could be clearly detected at day of hatch and d1 posthatch but not later. The expression of SGLT1 mRNA was localized to yolk sac endodermal epithelial cells and showed a sharp increase at the end of incubation. This increase of SGLT1 mRNA coincided with the increase in glucose in the yolk, indicating that the chicken embryo needs glucose as energy for hatching. The mRNA expression profiles of various avian beta defensins have been examined by qPCR and in situ hybridization to investigate the immune function of the yolk sac and small intestine. We found that AvBD10 mRNA showed the highest expression level in the yolk sac and was expressed predominantly in the yolk sac endodermal epithelial cells. Additionally, the expression of AvBD10 mRNA showed a development-specific pattern, which increased from e9 to e11, and decreased from e13 towards day of hatch. The expression patterns of AvBD1, 2, and 7 mRNA were similar to each other. These three genes were found to be expressed by chicken heterophils distributed in the yolk sac blood islands and small intestinal blood vessels. Only a subset of heterophils, which might be activated, were able to express AvBD1, 2, and 7 mRNA. In the intestine, the expression of AvBD10 mRNA was localized to cells along the villus at e19 and day of hatch, but later to only a few cells located above the intestinal crypts. In summary, the endodermal epithelial cells are responsible for the absorptive and immune functions of the chicken yolk sac. The yolk sac mesoderm is critical for embryonic hematopoiesis and innate immunity. The chicken small intestinal epithelial cells are derived from the intestinal stem cells in the crypts. These epithelial cells have different cell types, which are functioning to absorb nutrients and secrete antimicrobial peptides. / Ph. D. / The chicken yolk sac and small intestine are connected to each other and share many biological similarities. Both chicken small intestinal and yolk sac epithelia play critical roles for nutrient absorption and immune defense. In this dissertation, the mRNA for nutrient transporters such as the peptide transporter, PepT1 and the sodium-glucose co-transporter, SGLT1 were found to be expressed by absorptive epithelial cells in both the yolk sac and small intestine. Additionally, both intestinal and yolk sac epithelial cells expressed avian beta defensins (AvBDs), which are important chicken host defense peptides. In the small intestine, there are a number of differentiated cell types that originate from stem cells in the crypt that express the known mammalian stem cell markers, Olfm4 and Lgr5 mRNA. However, in the chicken yolk sac, only the stem cell marker Lgr5 mRNA was expressed by endothelial cells. In summary, the yolk sac epithelial cells are responsible for the absorptive and immune functions for the embryonic stage. The chicken small intestinal epithelial cells are derived from the intestinal stem cells in the crypts. These epithelial cells have different cell types, which function to absorb nutrients and secrete antimicrobial peptides.

In this thesis we deal with the Boolean functions with particular difference distribution vectors. Besides the main properties, we especially focus on strict avalanche criterion for cryptographic aspects. Not only we deal with known methods we also demonstrate some new methods for counting and constructing such functions. Furthermore, performing some statistical tests, we observed a number of interesting properties.

Les protéines kinases « Aurora » sont des régulatrices clés du cycle cellulaire. Alors que l'activité de Aurora-A est requise en début de la mitose, Aurora-B et -C sont nécessaires pour la fin de mitose. Toute perturbation de leur activité peut conduire au processus de tumorisation. Plus spécifiquement, Aurora-A se comporte à la fois comme oncogène et suppresseur de tumeur. Par conséquent, la connaissance du rôle de Aurora-A durant cycle cellulaire est essentielle. Toutefois, peu d'études ont exploré, jusque là, le rôle de Aurora-A dans les phases tardives de la mitose. En fait, l'inhibition de Aurora-A conduit à l'arrêt du cycle rendant impossible de voir ce qui se passe au delà de la transition métaphase/anaphase. Néanmoins, en combinant le couple génétique chimique et inhibiteur spécifique, j'ai pu identifier une nouvelle fonction de la kinase Aurora-A liée au checkpoint (SAC). En effet, mes résultats montrent que l'inhibition de l'activité de Aurora-A induit un défaut de congression et une chute de l'index mitotique. Ce résultat paradoxal suggère un défaut du SAC. J'ai donc pu montré que cette inhibition outrepassait le SAC en perturbant la localisation aux kinétochores de Mad2 et BubR1. Cependant, ma tentative pour sauver le phénotype du SAC par le mutant S19D-P150Glued n'a pas réussi malgré que le mutant S19AP150Glued se soit comporté comme un vrai dominant négatif. Enfin, j'ai pu montré que l'activité de Aurora-A est requise pour maintenir le SAC actif durant la prométaphase. / Protein kinases "Aurora " are the key regulators of the cell cycle. While the activity of Aurora-A is required at the beginning of mitosis, Aurora-B and -C are required for the end of mitosis. Any disruption of their activity can lead to process tumorisation. Specifically, Aurora-A acts as both oncogene and tumor suppressor. Therefore, knowledge of the role of Aurora-A is essential for cell cycle. However, few studies have explored so far, the role of Aurora-A in the late stages of mitosis. In fact, inhibition of Aurora-A leads to cell cycle arrest making it impossible to see what happens beyond the transition metaphase / anaphase. However, by combining chemical genetics couple and specific inhibitor, I have identified a new function of Aurora-A kinase -related checkpoint (SAC). Indeed, my results show that inhibition of the activity of Aurora-A induces a congression defect and the mitotic index decrease. This paradoxical result suggests a defect in the SAC. So I have shown that this inhibition was beyond the SAC disrupting kinetochore localization of Mad2 and BubR1. However, my attempt to rescue the phenotype of the SAC by the S19D-P150Glued mutant failed despite the fact that S19A-P150Glued mutant behaved like a true negative dominant. Finally, I have shown that the activity of Aurora-A is required to maintain the active SAC during prometaphase.

La transmission correcte du matériel génétique au cours de la mitose requiert l’attachement correct des chromosomes aux microtubules du fuseau mitotique. Les centromères au niveau des chromosomes servent de site d’assemblage aux kinétochores, interfaces multiprotéiques permettant la liaison des microtubules. Cependant, nous avons récemment mis en évidence chez la drosophile un mécanisme par lequel les fragments acentriques ségrégent normalement. Celui-­‐ci fonctionne grâce à un « tether », un filament d’ADN, qui relie les fragments acentriques à leurs partenaires centriques. L’intégrité du tether dépend de la fonction de BubR1, qui s’accumule au tether pendant de la mitose. BubR1 est une protéine clé dans le point de contrôle d’assemblage du fuseau mitotique, ou SAC (Spindle Assembly Checkpoint), qui contrôle l’attachement correct des kinétochores aux microtubules et inhibe l’entrée en anaphase. Nous avons voulu déterminer comment BubR1 est recrutée au tether, et nous avons montré que ce recrutement est dépendant du Bub3 Binding Domain de BubR1 et plus précisément de l’acide aminé E481 dans ce domaine. L’interaction Bub3-­‐BubR1 par l’intermédiaire de ce domaine est nécessaire à la localisation du complexe au tether. Nous avons également montré que BubR1 recrute à son tour Fzy par l’intermédiaire de son domaine KEN.Nous proposons un modèle dans lequel le recrutement successif de Bub3-­‐BubR1 et Fzy au niveau des chromosomes endommagés est nécessaire à leur bonne ségrégation en mitose. / Accurate transmission of genome during mitosis requires proper chromosomes attachment to microtubules of the mitotic spindle. Centromeres of chromosomes are assembly sites for kinetochores, multiproteic interfaces for microtubule binding. However, we recently discovered in Drosophila a mechanism that permits proper acentric chromosomes segregation. This mechanism works through a DNA « tether » that binds together acentric chromosomes to their centric counterparts. Tether integrity depends on BubR1 function, which accumulates on the tether during mitosis. BubR1 is a key protein in the Spindle Assembly Checkpoint (SAC), which monitors proper kinetochore-­‐microtubule attachment, and inhibits anaphase onset until all kinetochores are properly bound to microtubules. We wanted to determine how BubR1 is recruted to the tether, and we showed that this recruitment is dependant on the Bub3-­‐Binding Domain of BubR1, and more precisely the E481 amino acid. Bub3-­‐BubR1 interaction mediated by this domain is necessary for complex localisation on the tether. We also discovered that BubR1 then recruits Fzy via its KEN domain. We propose a model where successive recruiting of Bub3-­‐BubR1 and Fzy at the broken chromosome level is mandatory to their proper segregation in mitosis.

科学研究費補助金 研究種目:一般研究(B) 課題番号:01470008 研究代表者:平尾 公彦 研究期間:1989-1990年度

A relação da podoplanina com a proliferação celular tem sido demonstrada, porém ainda é tema de controvérsia. O objetivo deste estudo foi investigar a expressão da podoplanina em ameloblastomas e remanescentes de epitélio odontogênico (REO) de folículos pericoronários de dentes não-irrompidos e verificar a relação da imunomarcação da podoplanina com a proliferação celular. A amostra incluiu 33 pacientes submetidos à biópsia incisional ou à exérese de ameloblastomas e 32 folículos de pacientes submetidos à extração de dentes não-irrompidos. Todos os espécimes selecionados foram corados pela técnica imuno-histoquímica com os anticorpos anti-podoplanina e anti-Ki-67. A expressão da podoplanina foi avaliada por um método semi-quantitativo de escores. Já o índice de proliferação celular foi obtido pela porcentagem de células positivas (no mínimo 500 células/ameloblastoma e todas as células do REO foram avaliadas). Todos os ameloblastomas apresentaram imunomarcação pela podoplanina nas células periféricas. Nas células centrais, a expressão foi ausente ou fraca. Nos REO, a podoplanina apresentou expressão predominantemente nas células em contato com o tecido conjuntivo. A expressão membranosa da podoplanina foi superior nos ameloblastomas em relação aos REO (!=0,001). Também houve diferença significante entre a imunomarcação citoplasmática e membranosa da podoplanina nos REO (!=0,001). A expressão do Ki-67 foi mais acentuada nos ameloblastomas do que nos REO (!<0,001). A correlação entre a expressão citoplasmática (r= -0,15, != 0, 396) e membranosa (r= 0,00, != 0, 989) da podoplanina e do Ki-67 nos ameloblastomas não foi estatisticamente significante, tampouco entre a imunomarcação citoplasmática (r= 0,15, != 0, 421) e membranosa (r= -0, 09, ! = 0, 629) da podoplanina e do Ki-67 nos REO. Os resultados sugerem que não há associação da podoplanina com a proliferação celular e reforçam a necessidade da elucidação do papel desta proteína em tumores odontogênicos benignos. / The association between podoplanin and cellular proliferative activity has been demonstrated but is still source of debate. The aim of this study was to investigate the expression of podoplanin in ameloblastomas and remnants of odontogenic epithelium (ROE) from dental follicles of unerupted teeth and verify the relation between the podoplanin expression and proliferative activity of the odontogenic cells. Thirty-three patients submitted to the incisional biopsy or resection of ameloblastoma and 32 patients submitted to the extraction of unerupted tooth were selected for analysis. Archived paraffin-embedded ameloblastomas and dental follicles specimens were sectioned and stained with anti-human podoplanin and anti-Ki-67 antibodies. The podoplanin expression by odontogenic epithelial cells was evaluated using a score method and the Ki-67 labelling index was obtained by the percentage of positive odontogenic cells (at least 500 cells/ameloblastoma and all ROE cells). All ameloblastomas showed podoplanin expression in ameloblast-like cells of the epithelial islands. Weak or absent immunostaining was observed in the central cells resembling stellate reticulum. Podoplanin expression in ROE was mainly found in the cells in contact with the connective tissue. Membranous expression of podoplanin in ameloblastomas was stronger than its expression in ROE (!=0.001). Statistically significant difference between cytoplasmic and membranous expression of podoplanin in ROE was observed (!=0.001). The index of cellular odontogenic proliferative activity, verified by Ki-67 expression, was highest in ameloblastomas when compared with ROES (!<0.001). No statistically significant correlation between podoplanin and cellular odontogenic proliferative activity in ameloblastomas and dental follicles was found (!>0.05). These results support the evidence that there is no connection between podoplanin expression and odontogenic cellular proliferative activity in ameloblastomas and reinforce that the exact role of this protein in benign odontogenic tumor needs to be elucidated.

O saco vitelino é uma das membranas extra-embrionárias que desempenha um papel importante para a sobrevivência inicial do embrião, atua como fonte de nutrição durante o período em que a placenta verdadeira ainda não está completamente formada. É uma provável fonte de células tronco, o qual abriga as primeiras células do sangue durante o desenvolvimento em mamíferos, os eritrócitos, os quais expressam fatores de transcrição que especificam estas células a seu destino hematopoiético. O objetivo deste trabalho foi caracterizar as células tronco hematopoéticas provenientes do saco vitelino de embriões bovinos, em diferentes fases gestacionais, sendo estes coletados em abatedouro local. Para descrição da análise macroscópica e cultivo celular das células do saco vitelino, os embriões bovinos foram divididos em grupos de idade gestacional: Grupo I (25 a 29 dias), Grupo II (30 a 34 dias), Grupo III (35 a 39 dias), Grupo IV (40 a 44 dias) e Grupo V (45 a 50 dias) em que permaneceram mais tempo em cultura e apresentaram a formação de aglomerados celulares, diferente dos grupos IV e V (40 a 45 dias) em que permaneceram poucos dias em cultura e não apresentaram aglomerados celulares. Esta divergência relaciona-se à idade gestacional (45 a 50 dias), período em que se inicia a regressão do saco vitelino. Em citometria de fluxo os grupos I, II e III (25 a 39 dias) obtiveram características semelhantes, alta expressão de marcadores hematopoéticos (CD34, CD90 e CD117). Para os grupos IV e V (40 a 50 dias) observa-se um declínio da expressão de CD34 e CD117 (marcadores hematopoéticos) e no grupo V houve um acréscimo da expressão de CD45 (marcador para leucócito) confirmando que estas células não estão mantendo-se indiferenciadas As células demonstraram ser resistentes a criopreservação, capazes de formar colônias em matriz de Metilcelulose, mostraram a formação de colônias após 14 dias em cultivo e a morfologia para células sanguíneas (linfócitos e monócitos) foi confirmada na citologia celular. Na expressão gênica obteve-se baixa expressão do gene GATA3, níveis diferentes de expressão entre os grupos para o marcador RUNX1 e ANXA5. Dessa forma, nossos achados mais significativos comprovaram o isolamento de células hematopoéticas a partir do saco vitelino de embriões bovinos, sugerindo que este é uma fonte laboriosa, porém viável e eficaz para a obtenção de células tronco para futuras aplicações na terapia celular e gênica. / The yolk sac is one of the extra-embryonic membranes which plays an important role in early embryonic survival and serves as source of nutrition during the period where in the placenta is not completely true formed. The yolk sac is a likely source of stem cells, which have first blood cells during development in mammals, the red blood cells, which express transcription factors that specify these hematopoietic cells to their destination. This study aimed to identify and characterize hematopoietic stem cells from the yolk sac of bovine embryos at different stages of pregnancy, which are collected at a local slaughterhouse. For a description of the macroscopic and cellular culture of yolk sac cells, are as follows bovine embryos were divided into groups of gestational age: Group I (25 to 29 days), Group II (30 to 34 days), Group III (35 to 39 days ), Group IV (40 to 44 days) and Group V (45 to 50 days) which stayed longer in culture and showed the formation of cell clusters, different from groups IV and V (40-45 days) in few that remained days in culture and showed no cell clumps. This divergence is related to gestational age (45 to 50 days), during which begins regression of the yolk sac. In flow cytometry groups I, II and III (25 to 39 days) had similar characteristics, high expression of hematopoietic markers (CD34, CD90 and CD117). For the groups IV and V (40 to 50 days) it is observed a decrease in expression of CD117 and CD34 (hematopoietic markers) and in group V were increased expression of CD45 (leukocyte marker), confirming that these cells are not keeping Undifferentiated cells are shown to be resistant to cryopreservation, capable of forming colonies in methylcellulose matrix showed the formation of colonies after 14 days in culture morphology and to blood cells (lymphocytes and monocytes) was confirmed by cytology cell. In gene expression was low GATA3 gene expression, different levels of expression between the groups for the marker and RUNX1 ANXA5. Our most significant findings confirmed the isolation and identification of hematopoietic cells from the bovine embryo yolk sac, therefore, it is feasible and an effective way of obtaining stem cells for future applications in cell therapy and gene.

Syftet med denna undersökning har varit att studera de frågor och punkter som togs upp under avdelning nr. 22:s fackliga möte och se om och hur de reflekterats av de konflikter som fanns både i världen och i Sverige under 1917. Jag ville undersöka alla frågor som togs upp under mötena och sedan se om det fanns några spår efter första världskriget, den ryska revolutionen eller de konflikter som på gick i Sverige. Jag ville även undersöka om det fanns något spår av den rivaliteten mellan reformisterna och syndikalisterna som den tidigare forskningen visat på. För att genomföra undersökningen har jag använt mig av protokoll från avdelning nr.22:s möten som finns vid Lindesbergs kulturhistoriska arkiv. Först antecknades alla frågor som togs upp under året och sedan lades fokusen på ord som kan kopplas till Kriget, revolutionen och konflikterna. Dessa ord var krig, strejk, dyrtid, malmexport, revolution, syndikalismen (LS) och arbetslöshet.   Då alla mötens protokoll lästs igenom och dess punkter/frågor antecknades, sammanfattades de sedan efter tre kategorier, avdelning nr.22, arbetsvillkor och externa frågor. Dessa sammanfattningar förenklades sedan undersökningen av de återstående forskningsfrågorna. Resultatet till den första forskningsfrågan som handlade om vilka mötesfrågor som avdelning nr.22 tog upp en under året visar att de hade en stor variation av ämnen. De fackliga medlemmarna tog upp frågor som kunde röra interna problem, externa problem och arbetsvillkor. De interna problemen kunde vara rekryteringen av medlemmar och de externa frågorna kunde beröra välgörenhet. Frågor som berörde arbetsvillkoren handlade till stor del om prislistor och begäran om ökade löner. Den andra forskningsfrågan berörde hur vida avdelning nr.22 blev påverkade av de problem som fanns i Sverige och världen under den här tiden. Resultatet blev att det märktes av i protokollen. De började bland annat tidigt att diskutera strejker i samband med de konflikter som pågick i Sverige under den här tiden. Första världskriget förde med sig frågan om dyrtidstilläggen och höjda levnadskostnader för medlemmarna. Den ryska revolutionen är svårare att direkt koppla till det som togs upp under mötena, men att avdelning nr.22 startades upp igen kan vara en av effekterna från detta. Sista forskningsfrågan belyste om det fanns någon rivalitet mellan syndikalisterna och reformisterna vid gruvan. Resultatet blev här att protokollen inte visar på att det skulle varit någon rivalitet mellan dem, även om det går att läsa genom raderna att en viss spänning kan ha funnits där.

Thesis supervisor: E. Arthur Bettis, III. Includes bibliographic references (p. 102-107).

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) / Approved for entry into archive by Nadsa Cid(nadsa@ufc.br) on 2011-12-02T19:30:43Z (GMT) No. of bitstreams: 1 2007_dis_adslima.pdf: 2071706 bytes, checksum: 515e8e6c8c757b34d245885074813a89 (MD5) / Made available in DSpace on 2011-12-02T19:30:43Z (GMT). No. of bitstreams: 1 2007_dis_adslima.pdf: 2071706 bytes, checksum: 515e8e6c8c757b34d245885074813a89 (MD5) Previous issue date: 2007 / 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.