No description available.

Fundação de Amparo à Pesquisa do Estado do Rio de Janeiro / Por serem organismos filtradores, os mexilhões devem ser extraídos para consumo somente de águas com padrões microbiológicos regulamentados pelo Conselho Nacional do Meio Ambiente, uma vez que intoxicações alimentares de origem bacteriana são as consequências mais comuns relacionadas ao consumo destes moluscos. Após a retirada dos costões, estes organismos passam por processos de fervura, lavagem, acondicionamento em sacos plásticos e transporte até a chegada ao mercado onde são comercializados; etapas estas, realizadas sem cuidados assépticos. Objetivando avaliar a qualidade microbiológica de mexilhões Perna perna coletados na praia de Itaipu, Niterói, RJ; após a sua fervura; e comercializados no Mercado São Pedro, foram realizadas contagens de coliformes totais e termotolerantes e pesquisa de Escherichia coli, Salmonella spp. e Vibrio spp. por metodologia convencional e molecular em amostras obtidas destes locais. Pelo teste de disco-difusão foi observado o perfil de resistência das cepas isoladas. Do total de amostras analisadas (27) apenas 3 dos mexilhões que sofreram processo de aferventação, 1 do comercializado e 3 do in natura, se encontravam dentro dos padrões aceitáveis pela legislação. Não houve diferença significativa entre as contagens de coliformes termotolerantes dos diferentes mexilhões analisados, mas sim entre os períodos seco e chuvoso. Somente uma das nove coletas de água mostrou-se própria para o cultivo de mexilhões (até 14 CF/mL). Foram isoladas e caracterizadas fisiológicamente, 77 estirpes da espécie E. coli, sendo confirmadas molecularmente por PCR os sorotipos EPEC, STEC e EAEC; 4 cepas Salmonella spp. sendo apenas uma confirmada por PCR; e das 57 cepas caracterizadas como Vibrio spp., 51 foram confirmadas por PCR, sendo 46 Vibrio spp., 2 V. cholerae, 1 V. vulnificus, 1 V. parahaemolyticus e 1 V. mimicus. Entre as estirpes de E. coli, 13% apresentaram multirresistência e 15,6% apresentaram resistência múltipla. A estirpe de Salmonella spp. se mostrou sensível a todos os antimicrobiados testados. Das estirpes de Vibrio spp. testadas, 68,6% apresentaram multirresistência e 72,5% apresentaram resistência múltipla. A partir da pesquisa de genes direto do caldo de enriquecimento foi possível detectar todos os genes pesquisados, com exceção para os sorotipos de Salmonella e V. cholerae. Baseado nos resultados do presente trabalho pode-se inferir que os mexilhões, amplamente comercializados no município de Itaipú, podem se constituir em risco para a saúde pública dos consumidores no Rio de Janeiro, necessitando dos órgãos competentes uma eficiente fiscalização nos pontos de venda e cultivo destes moluscos. / Mussels (Perna perna) feed by filtering large quantities of water, enabling the retention of environmental bacteria and virus in their bodies. For this reason bacterial foodborne intoxications associated with these bivalves are common therefore mussels used for human consumption have to come from coastal areas where the microbiological quality of the water complies with current legislation laid down by the Conselho Nacional do Meio Ambiente. Following harvest these mussels go through a process of washing, boiling, packing and then transported to the fish markets for retail. During these processes and techniques normally no food hygiene plan is followed which may enable microorganisms growth and cross-contamination. The aim of this study was to determine the microbiological quality of Perna perna growing in Itaipu beach, Niterói, RJ from direct harvest (boiled and raw) and retailed at the São Pedro fish market. By using the MPN test it was possible to determine the total and faecal coliforms and by conventional and molecular techniques it was detected and identified the Escherichia coli, Salmonella spp. and Vibrio spp. present in the samples. The antimicrobial susceptibility test was also performed to determine the antimicrobial resistance profile of the isolated strains. From all the samples studied (27) only 7 samples had results complying with the legislation, 3 which suffered boiling process in the laboratory, 3 raw samples and 1 samples from the fish market. There were no significant differences between samples regarding the faecal coliforms count, however there was significant differences between samples collected in different seasons (dry and rainy). From all the nine water samples collected only one demonstrated to be proper for the production and harvest of mussels (lower than 14 CF/mL). There were 77 E. coli strains who were isolated and physiologically characterized and those results confirmed by PCR the sorotypo EPEC, STEC and EAEC; 4 strains of Salmonella spp. only one confirmed by PCR; and from the 57 strains identified as Vibrio spp., 51 were confirmed by PCR, where 46 were Vibrio spp., 2 V. cholerae, 1 V. vulnificus, 1 V. parahaemolyticus and 1 V. mimicus. From all the E. coli strains 13% were multi-resistant and 15.6% showed multiple resistance. All the Salmonella spp. strains demonstrated sensitivity to all tested antimicrobials. In the Vibrio spp. strains 68.6% were multi-resistant and 72.5% had multiple resistance Targeted genes were all possible to detect directly from the analysis of the enrichment broth with the exception for Salmonella and V. cholera genes. The present study provided results that demonstrate the poor microbiological quality of the mussels retailed in Itaipú borough which can represent a public health risk for all local and tourist population. These outcome brings to light how inspections in all food chain of the product are paramount for public health.

Fundação de Amparo à Pesquisa do Estado do Rio de Janeiro / Por serem organismos filtradores, os mexilhões devem ser extraídos para consumo somente de águas com padrões microbiológicos regulamentados pelo Conselho Nacional do Meio Ambiente, uma vez que intoxicações alimentares de origem bacteriana são as consequências mais comuns relacionadas ao consumo destes moluscos. Após a retirada dos costões, estes organismos passam por processos de fervura, lavagem, acondicionamento em sacos plásticos e transporte até a chegada ao mercado onde são comercializados; etapas estas, realizadas sem cuidados assépticos. Objetivando avaliar a qualidade microbiológica de mexilhões Perna perna coletados na praia de Itaipu, Niterói, RJ; após a sua fervura; e comercializados no Mercado São Pedro, foram realizadas contagens de coliformes totais e termotolerantes e pesquisa de Escherichia coli, Salmonella spp. e Vibrio spp. por metodologia convencional e molecular em amostras obtidas destes locais. Pelo teste de disco-difusão foi observado o perfil de resistência das cepas isoladas. Do total de amostras analisadas (27) apenas 3 dos mexilhões que sofreram processo de aferventação, 1 do comercializado e 3 do in natura, se encontravam dentro dos padrões aceitáveis pela legislação. Não houve diferença significativa entre as contagens de coliformes termotolerantes dos diferentes mexilhões analisados, mas sim entre os períodos seco e chuvoso. Somente uma das nove coletas de água mostrou-se própria para o cultivo de mexilhões (até 14 CF/mL). Foram isoladas e caracterizadas fisiológicamente, 77 estirpes da espécie E. coli, sendo confirmadas molecularmente por PCR os sorotipos EPEC, STEC e EAEC; 4 cepas Salmonella spp. sendo apenas uma confirmada por PCR; e das 57 cepas caracterizadas como Vibrio spp., 51 foram confirmadas por PCR, sendo 46 Vibrio spp., 2 V. cholerae, 1 V. vulnificus, 1 V. parahaemolyticus e 1 V. mimicus. Entre as estirpes de E. coli, 13% apresentaram multirresistência e 15,6% apresentaram resistência múltipla. A estirpe de Salmonella spp. se mostrou sensível a todos os antimicrobiados testados. Das estirpes de Vibrio spp. testadas, 68,6% apresentaram multirresistência e 72,5% apresentaram resistência múltipla. A partir da pesquisa de genes direto do caldo de enriquecimento foi possível detectar todos os genes pesquisados, com exceção para os sorotipos de Salmonella e V. cholerae. Baseado nos resultados do presente trabalho pode-se inferir que os mexilhões, amplamente comercializados no município de Itaipú, podem se constituir em risco para a saúde pública dos consumidores no Rio de Janeiro, necessitando dos órgãos competentes uma eficiente fiscalização nos pontos de venda e cultivo destes moluscos. / Mussels (Perna perna) feed by filtering large quantities of water, enabling the retention of environmental bacteria and virus in their bodies. For this reason bacterial foodborne intoxications associated with these bivalves are common therefore mussels used for human consumption have to come from coastal areas where the microbiological quality of the water complies with current legislation laid down by the Conselho Nacional do Meio Ambiente. Following harvest these mussels go through a process of washing, boiling, packing and then transported to the fish markets for retail. During these processes and techniques normally no food hygiene plan is followed which may enable microorganisms growth and cross-contamination. The aim of this study was to determine the microbiological quality of Perna perna growing in Itaipu beach, Niterói, RJ from direct harvest (boiled and raw) and retailed at the São Pedro fish market. By using the MPN test it was possible to determine the total and faecal coliforms and by conventional and molecular techniques it was detected and identified the Escherichia coli, Salmonella spp. and Vibrio spp. present in the samples. The antimicrobial susceptibility test was also performed to determine the antimicrobial resistance profile of the isolated strains. From all the samples studied (27) only 7 samples had results complying with the legislation, 3 which suffered boiling process in the laboratory, 3 raw samples and 1 samples from the fish market. There were no significant differences between samples regarding the faecal coliforms count, however there was significant differences between samples collected in different seasons (dry and rainy). From all the nine water samples collected only one demonstrated to be proper for the production and harvest of mussels (lower than 14 CF/mL). There were 77 E. coli strains who were isolated and physiologically characterized and those results confirmed by PCR the sorotypo EPEC, STEC and EAEC; 4 strains of Salmonella spp. only one confirmed by PCR; and from the 57 strains identified as Vibrio spp., 51 were confirmed by PCR, where 46 were Vibrio spp., 2 V. cholerae, 1 V. vulnificus, 1 V. parahaemolyticus and 1 V. mimicus. From all the E. coli strains 13% were multi-resistant and 15.6% showed multiple resistance. All the Salmonella spp. strains demonstrated sensitivity to all tested antimicrobials. In the Vibrio spp. strains 68.6% were multi-resistant and 72.5% had multiple resistance Targeted genes were all possible to detect directly from the analysis of the enrichment broth with the exception for Salmonella and V. cholera genes. The present study provided results that demonstrate the poor microbiological quality of the mussels retailed in Itaipú borough which can represent a public health risk for all local and tourist population. These outcome brings to light how inspections in all food chain of the product are paramount for public health.

Les épisodes de mortalité massive de l’huître creuse Crassostreae gigas observés sur les côtes françaises depuis 2008 ont été associés à certaines espèces appartenant au genre bactérien Vibrio. Ces mortalités, particulièrement intenses et rapides au cœur des lagunes méditerranéennes, atteignent 80 à 100% de la production ostréicole remettant ainsi en cause la pérennité de cette activité. Une surveillance environnementale de ces bactéries apparait donc essentielle et nécessite la mise au point de méthodes d’analyse innovantes, alternatives aux techniques couramment employées, afin de permettre un suivi rapide et en temps réel des Vibrio dans les milieux aquatiques côtiers.Dans ce contexte, l’objectif de cette thèse a été de concevoir des outils analytiques de type génocapteurs pour la détection et la quantification des Vibrio dans les écosystèmes aquatiques. Dans un premier temps, un système basé sur un format d’hybridation « sandwich » reposant sur l’intercalation des acides nucléiques cibles entre une sonde capture immobilisée et une sonde signal marquée, couplé à une détection optique, a été élaboré. Après optimisation des conditions expérimentales, le test développé s’est avéré très sensible avec une limite de détection de 5 ng.µL-1 d’acides nucléiques, ainsi qu’hautement spécifique du genre Vibrio. La méthode a ensuite été appliquée avec succès à la détection des Vibrio dans des échantillons environnementaux, collectés dans la lagune de Salses-Leucate. Un second format d’hybridation, basé sur la compétition entre les acides nucléiques cibles et la sonde capture pour la sonde signal, a ensuite été envisagé en utilisant aussi bien une transduction optique qu’électrochimique. En parallèle, des méthodes de PCR quantitative en temps réel ont été mises au point afin de servir de références pour la validation des génocapteurs. / Mass mortality events affecting the Pacific oyster Crassostreae gigas on French coasts since 2008 have been associated to some Vibrio species. These mortalities, particularly severe and sudden in the mediterranean lagoons, can reach 80 to 100% of the oyster production threatening the sustainability of this activity. An environmental monitoring of these bacteria appears essential and, for this purpose, innovative analytical methods have to be developed as alternative to classical techniques, in order to allow the rapid and in real time monitoring of Vibrio in the coastal aquatic environments. In this context, the objective of the thesis was to design genosensors as analytical tools for Vibrio detection and quantification in aquatic ecosystems. In a first step, a system based on a « sandwich » hybridization format, in which nucleic acid targets were bound between an immobilized capture probe and a labeled signal probe, coupled with an optical detection method, was developed. After experimental condition optimization, the test showed high sensitivity with a limit of detection of 5 ng.µL-1 of nucleic acids and was highly specific to Vibrio spp. The method was then successfully applied to Vibrio detection in environmental samples collected in Salses-Leucate lagoon. A second hybridization format, based on a competition between the targeted nucleic acids and the capture probe for the signal probe has been considered using both optical and electrochemical transductions. Concurrently with the development of genosensors, quantitative real-time PCR have been designed as reference methods.

Submitted by (edna.saturno@ufrpe.br) on 2017-02-21T16:11:44Z No. of bitstreams: 1 Roseli Pimentel Pinheiro e Silva.pdf: 245935 bytes, checksum: 769eb187840e50bd513ec06abe7683e0 (MD5) / Made available in DSpace on 2017-02-21T16:11:44Z (GMT). No. of bitstreams: 1 Roseli Pimentel Pinheiro e Silva.pdf: 245935 bytes, checksum: 769eb187840e50bd513ec06abe7683e0 (MD5) Previous issue date: 2007-02-22 / 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.

High pressure processing (HPP) and gamma irradiation were applied to inactivate <i>Vibrio vulnificus</i> (MO624) and <i>Vibrio parahaemolyticus</i> (O3:K6 TX2103) in pure culture and in inoculated live oysters. <i>Vibrio</i> pure culture and inoculated oysters were exposed to pressures of 207 MPa (30 kpsi) to 552 MPa (80 kpsi) for 0 min to maximum of 20 min. More than 5.4 log reductions of <i>V. vulnificus</i> occurred at 345 MPa for 0 min in oysters; 345 MPa for 2 min can achieve 4 log reductions on <i>V. parahaemolyticus</i>. Dosage of 1 kGy gamma-irradiation was proved to be effective in producing <i>Vibrio</i> free oysters with comparable organoleptic quality to raw oysters. Thermal conductivity of shucked oysters was measured to be 0.58 to 0.68 W/m°C, as temperature increased from 0 to 50 °C, using a line heat source probe. The specific heat was measured by differential scanning calorimeter methods. It increased from 3.80 to 4.05 kJ/kg °C, when temperature rose from 10 to 50 °C. The thermal diffusivity was calculated employing the data of thermal conductivity, specific heat and density of shucked oysters. The results showed that, under the tested temperature range, thermal properties did not change significantly with temperature. The dielectric constant and loss factor of oysters were determined by an open-ended coaxial line probe connected to a network analyzer at frequency of 30 MHz to 3000 MHz from 1 to 55 °C. The penetration depth of dielectric heating was calculated to be 1.1 cm with the dielectric constant of 55 and loss factor of 14. A two-dimensional mathematical model was established to simulate the heat transfer of microwave heating using a fish gel. Finite difference method was utilized to solve partial differential heat transfer equations. The model was able to predict the temperature distribution in heated fish gel with an accuracy of ± 8°C. Applying the developed mathematical model, the lethality of <i>Vibrio</i> spp., artificially inoculated in live oysters, was estimated collectively by integrating the individual localized lethality of designated heating units. The predicted lethality was compared with microwave enumeration data on Vibrios in oysters. The observed maximum log reductions by microbial enumeration were 4.4 and 3.4 for <i>V. vulnificus</i> and <i>V. parahaemolyticus</i>, respectively. The lethality calculated by integrating temperature profiles was acceptable. The discrepancy between the estimated lethality and microbial test was attributed to the simplified model construction. The quality of processed oysters, including color, aroma and texture properties, was evaluated instrumentally by a digital image system, an electronic nose and universal testing machine. The performance of two electronic nose systems on their abilities to detect oyster aroma and classify the aroma data into distinct groups was evaluated using a trained sensory panel and microbial tests. Cyranose 320 system has demonstrated potential as a quality assessment tool due to its sound correlation with microbial quality data and sensory evaluation scores. According to the quality measurement results, high pressure processing conditions were recommended to be at 345 MPa for less than 3 min and 379 MPa for less than 1.5 min. Deterioration of the quality was distinct for oyster meats exposed to 60 °C or above by thermal processing. The critical thermal processing condition was identified to be 55 °C for 2 min. With careful control, microwave processing could be considered as a candidate for seafood processing to reduce potential bacterial hazard but still retain the quality of the product. / Ph. D.

Les coraux vivent en association symbiotique avec des algues dinoflagellées du genre Symbiodinium, distinguées en différents clades (A à I). Un même hôte peut abriter seul ou plusieurs de ces clades, a priori dépendant d’un contexte environnemental, suggérant qu’ils possèdent des propriétés physiologiques distinctes. Ainsi, les capacités de flexibilité et d’acquisition de clades pourraient être une issue pour la survie de l’holobionte face à divers stress. Dans le cadre de cette thèse, ces capacités ont été explorées chez plusieurs espèces coralliennes, décrites avec différentes flexibilités et sensibilités aux conditions environnementales. La diversité et la dynamique des communautés de Symbiodinium associées aux coraux ont été estimées à l’aide de la technique de PCR en temps réel et évaluées dans différents contextes environnementaux: naturels, lors d’un suivi spatio-temporel de 18 mois à Moorea, ou contrôlés, lors d'une incubation à différentes pCO2. Les coraux ont montré la possibilité d’héberger jusqu’à 3 ou 4 clades distincts, reconsidérant la notion de spécialiste (i.e. symbionte unique). Néanmoins, propre à l’hôte corallien, il a été mis en évidence la régulation de ‘signatures symbiotiques’ caractérisées par des profils particuliers d’association de clades, stables et durables. Des modifications sporadiques de ces profils, par switching et shuffling ont put être observées, indépendamment d’un contexte environnemental donné, suggérant la dynamique comme un mécanisme constitutif chez les coraux. Néanmoins, en cas de d’apparition d’épizooties de Vibrio spp. et d’une maladie corallienne il est suggéré que le clade D participe activement au ‘fitness’ de leur hôte. / Corals live in symbiosis with dinoflagellate algae of the genus Symbiodinium, divided into 9 clades (A to I). The same host can harbour one or more of these clades depending on the environmental context. This lead to the suggestion that each clade has its unique physiological property. Therefore the capacity of flexibility and acquisition of clades may be an issue for the survival of the holobiont against various stresses. In this thesis, these capacities have been explored in several coral species, described with various flexibilities and sensitivities facing different environmental conditions. The diversity and dynamics of Symbiodinium communities associated to corals were estimated by using the real-time PCR technique, and evaluated in different environmental contexts : natural, in an 18-month spatio-temporal survey around Moorea, or controlled, upon incubation with different pCO2. Some corals showed the ability to host up to 3 or 4 distinct clades, leading to a reconsideration of the specialist-concept (i.e. host associated with one symbiont type). Nevertheless, depending on the coral host, ‘symbiotic signature’ regulations have been revealed. Latter are characterized by specific clade combination profils, which are stable and sustainable. In addition, sporadic changes by switching and shuffling, were observed in a given profil, regardless of a given environmental context, suggesting the dynamics as an constitutive mechanism in corals. However, records of coral disease together with Vibrio spp outbreaks, suggested an active participation of clade D for the ‘fitness’ of the coral host.

No description available.