As fontes hídricas disponíveis para o consumo humano vêm sendo comprometidas. Para resolver este problema, várias técnicas de detecção de contaminação fecal foram desenvolvidas. Em 1982, Manja e colegas desenvolveram método H2S que é simples, rápida e de baixo custo e detecta bactérias produtoras de H2S e, assim, a contaminação fecal. Neste trabalho foi analisada a eficácia de detecção de micro-organismos produtores de H2S frente a adição de L-cistina (125mg/L e 250mg/L) e desoxicolato de sódio (DS) (0,1% e 0,3%) e na presença de bactérias não produtoras de H2S para verificar se a presença destas bactérias interferem na detecção dos isolados H2S+. Assim, comparou-se o teste H2S com a membrana filtrante e o Colilert®. Os resultados deste estudo indicam que o meio H2S com adição de 0,3% de desoxicolato de sódio se mostrou mais rápido e sensível. Quando comparado com outras metodologias clássicas, o meio com 0,3% apresentou uma ligeira queda na sensibilidade mas o método H2S se mostrou mais sensível que o Colilert. / Water supply for human consumption have been compromised. Several detection methods for fecal contamination have been developed to solve this problem. Manja and co-workers (1982) developed a simple, fast and low-cost method for fecal contamination based on detection of sulfate-reducing bacteria, the H2S method. This work aimed to analyse the detection efficiency of the H2S method under different conditions: with L-cystine (125mg/L e 250mg/L) and sodium deoxycholate (0.1% e 0.3%). Also, non-sulfate-reducing bacteria interference were evaluated. Comparison tests were made through membrane filtration and Colilert®. Our results indicate a faster and more sensible for the 0.3% sodium deoxycholate condition. Compared to other classic methodologies, the 0.3% sodium deoxycholate condition slightly decrease the sensibility. However the H2S method was more sensitive than the Colilert one.

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Essa dissertação apresenta um estudo sobre o acúmulo de matéria orgânica nos sedimentos do complexo estuarino lagunar Mundaú Manguaba (CELMM) utilizando lipídios (ácidos graxos, esteróis e alcoóis lineares) como marcadores moleculares , com o objetivo de avaliar as fontes (naturais e antrópicas) e a variação espacial e temporal na composição da matéria orgânica sedimentar, assim como a influência dos processos diagenéticos sobre a qualidade e a preservação da mesma. O CELMM é caracterizado por um alto potencial de reciclagem e retenção de materiais e está sujeito a diversas atividades antropogênicas, incluindo a urbanização e as práticas de monocultura de cana-de-açúcar, além de sofrer um processo acelerado de degradação ambiental. Através de análise estatística multivariada foi possível discenir as fontes dos lipídios e, a partir disto, identificar as contribuições de matéria orgânica planctônica (fitoplâncton e zooplâcton), terrígena e bacteriana para os diferentes compartimentos do CELMM. Foi possível identificar um incremento no acúmulo de matéria orgânica de origem autóctona nas lagoas nos últimos anos. Este efeito foi mais significativo em Mundaú, reflexo do maior nível de alteração antrópica nessa lagoa. O nível de contaminação fecal avaliado através de esteróis fecais pode ser considerado de médio a baixo, quando comparados com outros locais que também apresentam influência antrópica significativa. A transformação diagenética da matéria orgânica, avaliada através das razões estanol/esterol, mostrou que a atividade bacteriana no CELMM é significativa ainda na coluna dágua ou na interface água-sedimento, mas que após o soterramento a matéria orgânica fica preservada. / This thesis presents a study on the accumulation of organic matter in the sediments of the complex estuarine lagoon Mundaú Manguaba (CELMM) using lipids (fatty acids, sterols and linear alcohols) as molecular markers to evaluate the sources (natural and anthropogenic) and spatial and temporal variation in the composition of sedimentary organic matter, as well as the influence of diagenetic processes on the quality and preservation of it. The CELMM is characterized by a high potential for recycling and storage of materials and is subject to various anthropogenic activities, including urbanization and practice of monoculture of cane sugar, in addition to suffering an accelerated process of environmental degradation. By multivariate analysis was possible to discern sources of lipids, and from this, identify the contributions of organic matter - plankton (phytoplankton and zooplankton), terrigenous and bacterial - for different sectors CELMM. It was possible to identify an increase in the accumulation of organic matter of autochthonous origin in the lagoons in recent years. This effect was more significant in Mundaú, reflecting the higher level of anthropogenic disturbance at the pool. The level of fecal contamination - assessed through fecal sterols - may be considered medium to low compared with other sites that also have significant human influence. The diagenetic transformation of organic matter as measured by the reasons stanol / sterol, showed that bacterial activity in CELMM is significant even in the water column or sediment-water interface, but that after the burial of organic matter is preserved.

Made available in DSpace on 2016-12-08T16:24:12Z (GMT). No. of bitstreams: 1 PGCA13MA093.pdf: 543541 bytes, checksum: 2136d34c3c485f243664708b98863911 (MD5) Previous issue date: 2013-04-15 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Broiler production and processing have several points to be monitored to reduce the losses and to improve meat quality. Among these points, an important point is related to bird processing on the slaughterhouse, highlighting the evisceration. This step may cause large losses for the industry by the condemnation of carcasses by fecal contamination. The current Brazilian legislation allows the removal of contaminated parts through the process called trimming using a knife, and more recently the use of washing carcasses by shower sprays was also approved. However, there is no consensus regarding the efficiency of the washing process. Thus this study aimed to evaluate both decontamination processes used by the industry. Five groups of broiler carcasses were evaluated: with fecal contamination (CC); without apparent fecal contamination (SCA); with contamination and trimmed (CCR); with contamination and washed (CL); contaminated and washed/trimmed (CLR). Microbiological testing of all carcasses evaluated mesophiles, total coliforms, E. coli, and the presence and quantification of Salmonella spp by the most probable number method (MPN). For mesophiles the group that obtained the lowest scores was the CLR, with a significant difference for the CCR group that obtained the highest scores. Regarding the CC group, carcasses from the group CLR had a reduction of 1 log CFU/g. CL groups, SCA and CC had no significant differences for mesophiles. Washed carcasses (CL) had significant total coliform reduction compared to trimmed group (P<0.05) with a reduction of 1.33 log CFU/g compared to the CC group. Similar results were obtained for E. coli, where the CL group was statistically better than the CCR. Salmonella spp results demonstrated that the CL group had the lowest percentage of positivity. The total positive carcasses subjected to quantification, 75% had values of 0-10 MPN/g. It is concluded that the washing process is efficient in reducing the count of total coliforms. It is possible to conclude that carcass washing was equally or more effective than trimming / A produção e o processamento de frangos de corte possuem vários pontos a serem monitorados para que ocorra redução das perdas produtivas e a produção de carne de excelente qualidade. Dentre estes pontos, um está relacionado ao abate, principalmente a evisceração. Esta etapa pode causar grandes perdas por condenação de carcaças contaminadas com conteúdo fecal. A atual legislação brasileira permite a remoção da contaminação através do processo de retirada da parte contaminada com auxílio de faca (refile) e mais recentemente a utilização da lavagem de carcaças. Não havendo consenso em relação à eficiência do processo de lavagem, este trabalho objetivou verificar a eficiência do processo de lavagem com água através de chuveiros na redução de mesófilos aeróbios, coliformes totais, Escherichia coli e Salmonella spp em carcaças de frango de corte na etapa de pós-evisceração comparado com o refile. Foram realizadas quatro coletas de 25 carcaças cada de frangos de corte recém eviscerados em um frigorífico catarinense. Cinco carcaças provenientes do mesmo lote e turno de abate foram coletadas para cada grupo avaliado: com contaminação fecal (CC); sem contaminação fecal aparente (SCA); com contaminação e refiladas (CCR); com contaminação lavada (CL); e com contaminação lavada e refilada (CLR). A análise microbiológica das carcaças avaliou mesófilos totais, coliformes totais, E. coli e a presença com posterior quantificação de Salmonella spp pelo método do número mais provável (NMP). Para mesófilos o grupo CLR obteve as menores contagens, com diferença significativa para o grupo CCR que obteve as maiores contagens. Em relação ao grupo CC, as carcaças lavadas e refiladas apresentaram redução de 1 log UFC/g. Os grupos CL, SCA e CC não apresentaram diferença significativa para mesófilos. Na avaliação de coliformes totais, o tratamento de lavagem foi estatisticamente melhor que o refile, observando redução na contagem do grupo CL de 1,33 log UFC/g em relação ao grupo CC. Resultado semelhante foi obtido para E. coli, onde o grupo CL foi estatisticamente melhor que o CCR. Na pesquisa de Salmonella spp os resultados demonstram que o grupo CL teve a menor porcentagem de positividade. Do total de carcaças positivas submetidas à quantificação, 75% apresentaram valores de 0-10 NMP/g. Conclui-se que a lavagem é um processo eficiente na redução da contagem de coliformes totais das carcaças. Comparativamente a lavagem foi tão ou mais eficiente que o refile, já que reduziu a quantidade de Salmonella spp nas carcaças

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Essa dissertação apresenta um estudo sobre o acúmulo de matéria orgânica nos sedimentos do complexo estuarino lagunar Mundaú Manguaba (CELMM) utilizando lipídios (ácidos graxos, esteróis e alcoóis lineares) como marcadores moleculares , com o objetivo de avaliar as fontes (naturais e antrópicas) e a variação espacial e temporal na composição da matéria orgânica sedimentar, assim como a influência dos processos diagenéticos sobre a qualidade e a preservação da mesma. O CELMM é caracterizado por um alto potencial de reciclagem e retenção de materiais e está sujeito a diversas atividades antropogênicas, incluindo a urbanização e as práticas de monocultura de cana-de-açúcar, além de sofrer um processo acelerado de degradação ambiental. Através de análise estatística multivariada foi possível discenir as fontes dos lipídios e, a partir disto, identificar as contribuições de matéria orgânica planctônica (fitoplâncton e zooplâcton), terrígena e bacteriana para os diferentes compartimentos do CELMM. Foi possível identificar um incremento no acúmulo de matéria orgânica de origem autóctona nas lagoas nos últimos anos. Este efeito foi mais significativo em Mundaú, reflexo do maior nível de alteração antrópica nessa lagoa. O nível de contaminação fecal avaliado através de esteróis fecais pode ser considerado de médio a baixo, quando comparados com outros locais que também apresentam influência antrópica significativa. A transformação diagenética da matéria orgânica, avaliada através das razões estanol/esterol, mostrou que a atividade bacteriana no CELMM é significativa ainda na coluna dágua ou na interface água-sedimento, mas que após o soterramento a matéria orgânica fica preservada. / This thesis presents a study on the accumulation of organic matter in the sediments of the complex estuarine lagoon Mundaú Manguaba (CELMM) using lipids (fatty acids, sterols and linear alcohols) as molecular markers to evaluate the sources (natural and anthropogenic) and spatial and temporal variation in the composition of sedimentary organic matter, as well as the influence of diagenetic processes on the quality and preservation of it. The CELMM is characterized by a high potential for recycling and storage of materials and is subject to various anthropogenic activities, including urbanization and practice of monoculture of cane sugar, in addition to suffering an accelerated process of environmental degradation. By multivariate analysis was possible to discern sources of lipids, and from this, identify the contributions of organic matter - plankton (phytoplankton and zooplankton), terrigenous and bacterial - for different sectors CELMM. It was possible to identify an increase in the accumulation of organic matter of autochthonous origin in the lagoons in recent years. This effect was more significant in Mundaú, reflecting the higher level of anthropogenic disturbance at the pool. The level of fecal contamination - assessed through fecal sterols - may be considered medium to low compared with other sites that also have significant human influence. The diagenetic transformation of organic matter as measured by the reasons stanol / sterol, showed that bacterial activity in CELMM is significant even in the water column or sediment-water interface, but that after the burial of organic matter is preserved.

As fontes hídricas disponíveis para o consumo humano vêm sendo comprometidas. Para resolver este problema, várias técnicas de detecção de contaminação fecal foram desenvolvidas. Em 1982, Manja e colegas desenvolveram método H2S que é simples, rápida e de baixo custo e detecta bactérias produtoras de H2S e, assim, a contaminação fecal. Neste trabalho foi analisada a eficácia de detecção de micro-organismos produtores de H2S frente a adição de L-cistina (125mg/L e 250mg/L) e desoxicolato de sódio (DS) (0,1% e 0,3%) e na presença de bactérias não produtoras de H2S para verificar se a presença destas bactérias interferem na detecção dos isolados H2S+. Assim, comparou-se o teste H2S com a membrana filtrante e o Colilert®. Os resultados deste estudo indicam que o meio H2S com adição de 0,3% de desoxicolato de sódio se mostrou mais rápido e sensível. Quando comparado com outras metodologias clássicas, o meio com 0,3% apresentou uma ligeira queda na sensibilidade mas o método H2S se mostrou mais sensível que o Colilert. / Water supply for human consumption have been compromised. Several detection methods for fecal contamination have been developed to solve this problem. Manja and co-workers (1982) developed a simple, fast and low-cost method for fecal contamination based on detection of sulfate-reducing bacteria, the H2S method. This work aimed to analyse the detection efficiency of the H2S method under different conditions: with L-cystine (125mg/L e 250mg/L) and sodium deoxycholate (0.1% e 0.3%). Also, non-sulfate-reducing bacteria interference were evaluated. Comparison tests were made through membrane filtration and Colilert®. Our results indicate a faster and more sensible for the 0.3% sodium deoxycholate condition. Compared to other classic methodologies, the 0.3% sodium deoxycholate condition slightly decrease the sensibility. However the H2S method was more sensitive than the Colilert one.

The current environmental status of the majority of Bermuda’s one hundred sixty-six known caves was investigated. This survey replicated a historical cave study performed in 1983, wherein each was analyzed for positive and negative features. Statistical analysis of the data showed a significant difference between the historical and current survey ratings, with an overall decrease in environmental status. A water quality study was performed on twenty different caves with sea level pools in various locations around the island. Nitrate, nitrite, ammonia, and phosphate levels were measured from varying depths in these caves. Fifteen of these caves were also tested for the presence of fecal bacterial contamination. High nitrate levels were discovered in some of the caves, particularly in surface samples. Additionally, bacterial contamination was detected in some caves. No obvious relationship between cave size or location and contamination existed for any of the pollutants sampled. Three separate caves from this group were dived and analyzed using a Hydrolab Sonde 3 Multiprobe Logger to acquire in situ water column data including depth, temperature, pH, salinity, and dissolved oxygen. Each cave studied had its own unique trends in hydrology at varying depths in the water column. A later water sampling study with a randomized experimental design was created and caves were divided into four classes based on size and location. Surface and subsurface samples were gathered from twelve randomly selected caves, three from each class. Each sample was analyzed for nitrate, nitrite, and ammonia concentrations. The results were analyzed using multiple analysis of variance statistics. A significant difference between the nitrate concentrations in the surface and subsurface water samples was discovered. None of the other comparisons were statistically significant. To represent the data visually, a Bermuda Cave and Karst Information System (BeCKIS) was created using the environmental survey data and water quality information. Some of the maps generated highlighted regions where negative environmental impacts on caves were concentrated geographically, thus demonstrating how this geographic information system could be used as a conservation tool.

The current environmental status of the majority of Bermuda’s one hundred sixty-six known caves was investigated. This survey replicated a historical cave study performed in 1983, wherein each was analyzed for positive and negative features. Statistical analysis of the data showed a significant difference between the historical and current survey ratings, with an overall decrease in environmental status. A water quality study was performed on twenty different caves with sea level pools in various locations around the island. Nitrate, nitrite, ammonia, and phosphate levels were measured from varying depths in these caves. Fifteen of these caves were also tested for the presence of fecal bacterial contamination. High nitrate levels were discovered in some of the caves, particularly in surface samples. Additionally, bacterial contamination was detected in some caves. No obvious relationship between cave size or location and contamination existed for any of the pollutants sampled. Three separate caves from this group were dived and analyzed using a Hydrolab Sonde 3 Multiprobe Logger to acquire in situ water column data including depth, temperature, pH, salinity, and dissolved oxygen. Each cave studied had its own unique trends in hydrology at varying depths in the water column. A later water sampling study with a randomized experimental design was created and caves were divided into four classes based on size and location. Surface and subsurface samples were gathered from twelve randomly selected caves, three from each class. Each sample was analyzed for nitrate, nitrite, and ammonia concentrations. The results were analyzed using multiple analysis of variance statistics. A significant difference between the nitrate concentrations in the surface and subsurface water samples was discovered. None of the other comparisons were statistically significant. To represent the data visually, a Bermuda Cave and Karst Information System (BeCKIS) was created using the environmental survey data and water quality information. Some of the maps generated highlighted regions where negative environmental impacts on caves were concentrated geographically, thus demonstrating how this geographic information system could be used as a conservation tool.

Submitted by Alexandre Sousa (alexandre.sousa@incqs.fiocruz.br) on 2015-05-11T17:59:22Z No. of bitstreams: 1 Dissertação_Kayo_Bianco.pdf: 5086210 bytes, checksum: 14083186869c48adebe043f3e9e02a6c (MD5) / Approved for entry into archive by Alexandre Sousa (alexandre.sousa@incqs.fiocruz.br) on 2015-05-11T17:59:44Z (GMT) No. of bitstreams: 1 Dissertação_Kayo_Bianco.pdf: 5086210 bytes, checksum: 14083186869c48adebe043f3e9e02a6c (MD5) / Approved for entry into archive by Alexandre Sousa (alexandre.sousa@incqs.fiocruz.br) on 2015-05-11T17:59:54Z (GMT) No. of bitstreams: 1 Dissertação_Kayo_Bianco.pdf: 5086210 bytes, checksum: 14083186869c48adebe043f3e9e02a6c (MD5) / Made available in DSpace on 2015-05-11T17:59:54Z (GMT). No. of bitstreams: 1 Dissertação_Kayo_Bianco.pdf: 5086210 bytes, checksum: 14083186869c48adebe043f3e9e02a6c (MD5) Previous issue date: 2015 / Fundação Oswaldo Cruz. Instituto Nacional de Controle de Qualidade em Saúde / A contaminação fecal de corpos hídricos é uma das principais causas de doenças entéricas veiculadas pela água no mundo, responsáveis pela morte de mais de dois milhões de crianças por ano. As águas das bacias do rio São Joao e do rio Guandu vêm sendo destinadas ao abastecimento público da Região dos Lagos e da região metropolitana do estado do Rio de Janeiro. Os indicadores de contaminação fecal usualmente empregados na avaliação da qualidade microbiológica da água quanto a presença de patógenos entéricos são os coliformes termotolerantes, representados pela Escherichia coli, os quais estão associados com matéria fecal humana e de outros animais de sangue quente. Entretanto, para um gerenciamento mais efetivo deve ser identificada a fonte de contaminação fecal. Microrganismos anaeróbios, como a ordem Bacteroidalese as archaeas metanogênicas, vêm sendo apontados como bioindicadores alternativos de contaminação fecal hospedeiro-especifico. O presente estudo tem como objetivo avaliar a qualidade das águas das bacias do rio São João e do rio Guandu por meio da aplicação de biomarcadores moleculares capazes de revelar contaminações fecais suína, humana, equina e de ruminantes. Esta abordagem representa uma importante ferramenta na detecção de contaminação hospedeiro-específica de ambientes aquáticos, o que poderá contribuir para as ações preventivas de vigilância ambiental em saúde. / Fecal contamination of water bodies is a major cause of waterborne enteric diseases in the world, responsible for the deaths of more than two million children per year. The waters from São João river basin and Guandu river basin have been intended for public supply of the Lakes Region and the metropolitan region of the State of Rio de Janeiro. Indicators of fecal contamination usually employed to evaluate the microbiological quality of water for the presence of enteric pathogens are coliforms, represented by Escherichia coli, which are associated with human faecal matter and other warm-blooded animals. However,for a more effective management the source of fecal contamination should be identified. Anaerobic microorganisms, such as the order Bacteroidales and methanogenic archaea, have been identified asalternative biomarkers for host-specific fecal contamination. The present study aims to evaluate the water quality of São João river basinand Guandu riverbasinthrough the application of molecular biomarkers able to reveal swine, human, equine and ruminants fecal contamination. This approach represents an important tool in the detection of host-specific contamination of aquatic environments, which may contribute to prevention efforts for environmental health surveillance.

Made available in DSpace on 2014-12-17T15:03:22Z (GMT). No. of bitstreams: 1 JucaraRMpdf1-61.pdf: 2157479 bytes, checksum: 530d9910b960362ab6b98d5b3433665f (MD5) Previous issue date: 2009-08-19 / Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico / The Pirangi beach is located in the eastern coastline of Rio Grande do Norte state, in the municipality of Parnamirim and N?sia Floresta. In it flow into Pirangi Watershed (PW), whose water receives large amounts of pollutants, mainly domestic and industrial sewage from districts where pass the rivers that consist it, compromising, thus, the bathing water quality of the Pirangi beach. Bearing in mind the importance of water sanitary quality to ensure an environment that no present risk to the bathers s health, this work had as main objective to assess the influence of the PW s waters in the bathing water quality of the Pirangi beaches. To that end, were made collections of water in the beaches and in the rivers with the intention of quantify the fecal contamination indicators thermotolerant coliforms and enterococci, to then classify the conditions of bathing water quality according with the CONAMA Resolution number 274 of 2000. For the purposes greater knowledge about the health conditions of the Beaches Pirangi and about the influence the PW s waters exert on it, was done parallely to the study of the water quality, an investigation of the sand sanitary quality. Furthermore, it was made an evaluation of the PW s Water Quality through Water Quality Index (WQI). Starting from the results obtained in the research present was possible to verify, among other aspects, that the entry of the PW s waters in the Pirangi beaches exerts direct influence in the bathing water quality of the same ones, being the North Pirangi beach (point tracking PA-02) the most influenced. There was noticed also a significant reduction in the conditions of bathing water quality of the beaches in the rainy season. However, the precariousness do sewerage system of the Natal metropolitan region and the absence of a right system of treatment an final disposal of domestic sewage and industrial are the main factors responsi le for deterioration of the PW s Water Quality, and as a consequence, compromising the bathing water quality of the Pirangi beaches / A praia de Pirangi est? localizada no litoral oriental do Estado do Rio Grande do Norte, nos munic?pios de Parnamirim e N?sia Floresta. Nela des?gua a Bacia Hidrogr?fica Pirangi (BHP), cuja ?gua recebe grande quantidade de poluentes, principalmente esgotos dom?sticos e industriais dos munic?pios por onde passam os rios que a comp?em, comprometendo, dessa forma, a balneabilidade desta praia. Tendo em vista a import?ncia da qualidade sanit?ria da ?gua para se garantir um ambiente que n?o apresente riscos ? sa?de dos banhistas, o presente trabalho teve como objetivo principal avaliar a influ?ncia das ?guas da BHP na balneabilidade das praias de Pirangi. Para tanto, foram realizadas coletas de ?gua nas praias e nos rios com o intuito de quantificar os indicadores de contamina??o fecal Enterococos e Coliformes termotolerantes, para ent?o classificar as condi??es de balneabilidade de acordo com a resolu??o CONAMA n? 274 de 2000. Para efeito de maior embasamento sobre as condi??es sanit?rias das Praias de Pirangi e sobre a influ?ncia que as ?guas da BPH exercem sobre elas, foi realizada, paralelamente ao estudo da qualidade das ?guas, uma investiga??o da qualidade sanit?ria das areias. Al?m disso, foi feita uma avalia??o da qualidade da ?gua da BHP atrav?s do ?ndice de Qualidade da ?gua (IQA). A partir dos resultados obtidos na presente pesquisa foi poss?vel constatar, dentre outros aspectos, que a entrada das ?guas da BHP nas praias de Pirangi exerce influ?ncia direta na balneabilidade das mesmas, sendo a praia de Pirangi do Norte (ponto de monitoramento PA-02) a mais influenciada. Observou-se, tamb?m, redu??o significativa nas condi??es de balneabilidade das praias na esta??o chuvosa. Contudo, a precariedade do esgotamento sanit?rio da regi?o metropolitana de Natal e a aus?ncia de um sistema adequado de tratamento e disposi??o final dos esgotos dom sticos e industriais s?o os principais fatores respons?veis pela degrada??o da qualidade da ?gua da BHP, e como conseq??ncia, pelo comprometimento da balneabilidade das praias de Pirangi

La pollution microbienne des eaux récréatives peut engendrer un risque pour la santé des populations exposées. La contamination fécale de ces eaux représente une composante importante de ce risque, notamment par la présence possible d’agents pathogènes et par l’exposition à des micro-organismes résistants aux antimicrobiens. Les sources de pollution fécale sont multiples et incluent entre autres les activités agricoles et les productions animales. Ce projet visait donc à mieux comprendre les facteurs influençant la qualité microbiologique des eaux récréatives du Québec méridional, en ciblant le rôle possible des activités agricoles, ainsi qu`à proposer et évaluer de nouvelles sources de données pouvant contribuer à l’identification de ces facteurs. Dans un premier temps, une évaluation de la présence d’Escherichia coli résistants aux antimicrobiens dans les eaux récréatives à l’étude a été effectuée. À la lumière des résultats de cette première étude, ces eaux représenteraient une source de micro-organismes résistants aux antimicrobiens pour les personnes pratiquant des activités aquatiques, mais l’impact en santé publique d’une telle exposition demeure à déterminer. Les déterminants agroenvironnementaux associés à la présence de micro-organismes résistants aux antimicrobiens ont par la suite été explorés. Les résultats de ce chapitre suggèrent que les activités agricoles, et plus spécifiquement l’épandage de fumier liquide, seraient reliées à la contamination des eaux récréatives par des bactéries résistantes aux antimicrobiens. Le chapitre suivant visait à identifier des déterminants agroenvironnementaux temps-indépendants d’importance associés à la contamination fécale des eaux à l’étude. Différentes variables, regroupées en trois classes (activités agricoles, humaines et caractéristiques géohydrologiques), ont été explorées à travers un modèle de régression logistique multivarié. Il en est ressorti que les eaux récréatives ayant des sites de productions de ruminants à proximité, et en particulier à l’intérieur d’un rayon de 2 km, possédaient un risque plus élevé de contamination fécale. Une association positive a également été notée entre le niveau de contamination fécale et le fait que les plages soient situées à l’intérieur d’une zone urbaine. Cette composante nous permet donc de conclure qu’en regard à la santé publique, les eaux récréatives pourraient être contaminées par des sources de pollution fécale tant animales qu’humaines, et que celles-ci pourraient représenter un risque pour la santé des utilisateurs. Pour terminer, un modèle de régression logistique construit à l’aide de données issues de la télédétection et mettant en association un groupe de déterminants agroenvironnementaux et la contamination fécale des eaux récréatives a été mis au point. Ce chapitre visait à évaluer l’utilité de telles données dans l’identification de ces déterminants, de même qu`à discuter des avantages et contraintes associées à leur emploi dans le contexte de la surveillance de la qualité microbiologique des eaux récréatives. À travers cette étude, des associations positives ont été mises en évidence entre le niveau de contamination fécale des eaux et la superficie des terres agricoles adjacentes, de même qu’avec la présence de surfaces imperméables. Les données issues des images d’observation de la Terre pourraient donc constituer une valeur ajoutée pour les programmes de suivi de la qualité microbiologique de ces eaux en permettant une surveillance des déterminants y étant associés. / Microbial pollution of recreational waters may constitute a health risk for exposed populations. Fecal contamination of these waters represents an important component of this risk, especially due to the possible presence of pathogens and exposure to antimicrobial resistant microorganisms. Sources of fecal pollution are many and include agricultural activities and animal production. This project aims to better understand agroenvironmental factors influencing the microbiological quality of recreational waters of Southern Quebec and also suggests and assesses new sources of data which may contribute to the identification of these factors. An evaluation of the presence of antimicrobial resistant Escherichia coli in the recreational waters studied was first performed. Given the positive results found, certain bodies of waters may represent a source of antimicrobial resistant microorganisms for people engaged in water activities. However the public health impact of such exposure is still unknown. Agroenvironmental determinants associated with the presence of antimicrobial resistant microorganisms were investigated. Results of this chapter suggest that agricultural activities, especially liquid manure spreading, may be associated with the contamination of recreational waters with antimicrobial resistant microorganisms. The next chapter assesses key time-independent agroenvironmental determinants associated with the fecal contamination of studied recreational waters. Various variables – classified as either agricultural activities, human activities or geo-hydrological characteristics – are explored through a multivariate logistic regression model. It appears that recreational waters with ruminant productions in their proximal environment, especially when they are within a radius of 2 km, may present a higher risk of fecal contamination. A positive association was also noticed between the level of fecal contamination of a beach and its presence in an urban area. From a public health perspective, recreational waters may be contaminated by animal and human sources and these sources may represent a risk for bathers’ health. Finally, association between fecal contamination of recreational waters and agroenvironment determinants was studied through a logistic regression model built from remote sensing data. This chapter assesses the utility of such data in the identification of these determinants and discusses the strengths and the limitations of their use in the context of the monitoring of the microbiological quality of recreational waters. In this study, positive associations were found between the level of fecal contamination and both the proximity of agricultural lands and the presence of impervious surfaces. Earth observation data may constitute an added value for the water quality monitoring program in allowing the surveillance of the determinants associated with this quality.