O consumo de moluscos bivalves pode representar sérios riscos à saúde pública, pois refletem diretamente as condições do meio ambiente. Desta forma considera-se de extrema importância o consumo de mexilhões livres de contaminação. Esta pesquisa objetivou estudar a qualidade microbiológica das águas e mexilhões de três pontos de cultivo do município de Ubatuba, SP, a saber: Engenho da Almada, Barra Seca e Costão do Cedro em um período compreendido entre novembro de 2002 e março de 2003, totalizando 5 coletas mensais. Analisou-se na água: Bacillus cereus, Clostrídios Sulfito Redutores, Aeróbios Mesófilos, Staphylococcus aureus, Coliformes totais e fecais, Enterococos e Salmonella. Nos mexilhões foram analisados os mesmos microrganismos citados para água mais o Clostridium perfringens. Os resultados encontrados tanto para as análises de água como dos mexilhões foram satisfatórios, condizentes com a legislação brasileira em vigor, salvo a coleta do mês de março, do cultivo da Barra Seca, onde a média dos valores encontrados para coliformes fecais na água (5,7x101 NMP/100mL) foi superior ao recomendado pela legislação sendo detectado também neste mesmo cultivo e mês, presença de Salmonella em 25 g nas amostras de mexilhões. Mesmo que as contagens de S. aureus e B. cereus na carne estejam de acordo com a legislação em vigor, cuidados devem ser tomados quanto ao armazenamento e a forma de consumo. Averiguou-se a intensidade de interferências sazonais na contagem microbiana na água e constatou-se que a tábua de marés e o índice de insolação diária tiveram uma correlação negativa baixa, ao contrário do índice pluviométrico que apresentou correlação positiva alta. / The consumption of bivalve mollusks can represent serious risks to the public health, because they reflect the conditions of the environment directly. This way it is considered of extreme importance the consumption of mussels without contamination. This work aims of studing the water and mussels microbiology quality from three different seafood farms in Ubatuba, SP, to know: Engenho da Almada, Barra Seca and Costão do Cedro from November 2002 to March 2003, totaling five monthly. It was analyzed in the water: Bacillus cereus, Total Clostridia, Aerobic Mesophilic, Staphylococcus aureus, total and fecal coliforms, Enterococci and Salmonella. In the mussels the same microorganisms were analyzed mentioned for water more Clostridium perfringens. The results found in the water and in the mussels were satisfactory, suitable with the Brazilian legislation, except for the sample at Barra Seca’s beach, in March. The average of the values found at that place for fecal coliformes in the water was higher (5,7x101 MPN/100mL) than the recommended by the legislation. Even in this collection, it was also detected Salmonella in 25 g of mussels. Even if the counts of S. aureus and B. cereus in the mussesls are in agreement with the legislation in vigor cares they should be taken with relationship to the storage and the consumption form. The intensity of seasonal interferences was discovered in the microbial count in the water, in which was verified that the board of tides and the index of daily heatstroke had a low negative correlation unlike the index pluviometric it presented high positive correlation

Microbial pollution of surface waters and coastal zones is one of the foremost challenges facing the water industry and regulatory authorities. Yet despite the concern and increasing pressures on water resources in both developed and developing countries, understanding of microbial pollutants in the aquatic environment is fairly scattered. There is a need for an improved ability to quantify the processes that control the fate and distribution of enteric organisms to support decision - making and risk management activities. The aim of this thesis has been to advance the understanding of the dynamics of microbial pollution in aquatic systems through review, experimentation and numerical modelling. Initially, a new module for simulating the protozoan pathogen, Cryptosporidium, was developed and implemented within a three - dimensional ( 3D ) coupled hydrodynamic - water quality model ( ELCOMCAEDYM ). The coupled 3D model was validated against a comprehensive dataset collected in Myponga Reservoir ( South Australia ), and without calibration, performed to a high degree of accuracy. The investigation then sought to examine the experimental dataset in more detail and found a significant difference between protozoan pathogens and the bacterial and viral indicators. To examine the role of bacterial association with particles in more detail, a second experimental campaign was carried out in Sugarloaf Reservoir ( Victoria ). This campaign was used to gain insights into the association of coliform bacteria with suspended sediment and to quantify their sedimentation dynamics based on in situ measurements. Using an inverse technique, particle profile data was used to create a simple Lagrangian model that was applied to back - calculate the sedimentation rates of the coliform bacteria and the fraction that were attached to the particles. The results indicated that 80 - 100 % were associated with a small - sized clay fraction. This result was in contrast with the Cryptosporidium dynamics in Myponga Reservoir, where it was concluded that oocysts did not settle with the inorganic particles. These findings indicated the current models for simulating the array of organisms of interest to regulatory authorities are inadequate to resolve the level of detail necessary for useful predictions and risk management. Large differences between the protozoa, bacteria and phages were being observed due to different particle association rates and sedimentation dynamics, order of magnitude differences in natural mortality rates, and different sensitivity to sunlight bandwidths. The original model implemented within CAEDYM was therefore rewritten to be more complete and generic for all microbial pollutants and different types of aquatic systems. The model was built using a generic set of parameterizations that describe the dynamics of most protozoan, bacterial and viral organisms of interest. The parameterizations dynamically account for sensitivities to environmental conditions, including temperature, salinity, pH, dissolved oxygen, sunlight, nutrients and turbidity, on the growth and mortality of enteric organisms. The new model significantly advances previous studies in several areas. First, inclusion of the growth term allows for simulation of organisms in warm, nutrient rich environments, where typical die - off models tend to over - predict loss rates. Second, the natural mortality term has been extended to independently account for the effects of salinity and pH, in addition to temperature. The salinity - mediated mortality has also been adapted to account for the nutrient status of the medium to simulate the importance of nutrient starvation on the ability of an organism to survive under osmotic stress. Third, a new model for sunlight - mediated mortality is presented that differentially accounts for mortality induced through exposure to visible, UV - A and UV - B bandwidths. The new expression has capacity to simulate the photo - oxidative and photo - biological mechanisms of inactivation through included sensitivities to dissolved oxygen and pH. Fourth, the model allows for organisms to be split between free and attached pools, and sedimented organisms may become resuspended in response to high shear stress events at the water - sediment interface caused by high velocities or wind - wave action. Fifth, the enteric organism module has been implemented within the bio - geochemical model CAEDYM, thereby giving it access to dynamically calculated concentrations of dissolved oxygen, organic carbon, and suspended solids, in addition to pH, shear stress and light climate information. Without adjustment of the literature derived parameter values, the new model was validated against a range of microbial data from three reservoirs that differed in their climatic zone, trophic status and operation. The simulations in conjunction with the experimental data highlighted the large spatial and temporal variability in processes that control the fate and distribution of enteric organisms. Additionally, large differences between species originate from variable rates of growth, mortality and sedimentation and it is emphasized that the use of surrogates for quantifying risk is problematic. The model can be used to help design targeted monitoring programs, examine differences between species and the appropriateness of surrogate indicators, and to support management and real - time decision - making. Areas where insufficient data and understanding exist are also discussed. / Thesis (Ph.D.)--School of Earth and Environmental Sciences, 2007.

O consumo de moluscos bivalves pode representar sérios riscos à saúde pública, pois refletem diretamente as condições do meio ambiente. Desta forma considera-se de extrema importância o consumo de mexilhões livres de contaminação. Esta pesquisa objetivou estudar a qualidade microbiológica das águas e mexilhões de três pontos de cultivo do município de Ubatuba, SP, a saber: Engenho da Almada, Barra Seca e Costão do Cedro em um período compreendido entre novembro de 2002 e março de 2003, totalizando 5 coletas mensais. Analisou-se na água: Bacillus cereus, Clostrídios Sulfito Redutores, Aeróbios Mesófilos, Staphylococcus aureus, Coliformes totais e fecais, Enterococos e Salmonella. Nos mexilhões foram analisados os mesmos microrganismos citados para água mais o Clostridium perfringens. Os resultados encontrados tanto para as análises de água como dos mexilhões foram satisfatórios, condizentes com a legislação brasileira em vigor, salvo a coleta do mês de março, do cultivo da Barra Seca, onde a média dos valores encontrados para coliformes fecais na água (5,7x101 NMP/100mL) foi superior ao recomendado pela legislação sendo detectado também neste mesmo cultivo e mês, presença de Salmonella em 25 g nas amostras de mexilhões. Mesmo que as contagens de S. aureus e B. cereus na carne estejam de acordo com a legislação em vigor, cuidados devem ser tomados quanto ao armazenamento e a forma de consumo. Averiguou-se a intensidade de interferências sazonais na contagem microbiana na água e constatou-se que a tábua de marés e o índice de insolação diária tiveram uma correlação negativa baixa, ao contrário do índice pluviométrico que apresentou correlação positiva alta. / The consumption of bivalve mollusks can represent serious risks to the public health, because they reflect the conditions of the environment directly. This way it is considered of extreme importance the consumption of mussels without contamination. This work aims of studing the water and mussels microbiology quality from three different seafood farms in Ubatuba, SP, to know: Engenho da Almada, Barra Seca and Costão do Cedro from November 2002 to March 2003, totaling five monthly. It was analyzed in the water: Bacillus cereus, Total Clostridia, Aerobic Mesophilic, Staphylococcus aureus, total and fecal coliforms, Enterococci and Salmonella. In the mussels the same microorganisms were analyzed mentioned for water more Clostridium perfringens. The results found in the water and in the mussels were satisfactory, suitable with the Brazilian legislation, except for the sample at Barra Seca’s beach, in March. The average of the values found at that place for fecal coliformes in the water was higher (5,7x101 MPN/100mL) than the recommended by the legislation. Even in this collection, it was also detected Salmonella in 25 g of mussels. Even if the counts of S. aureus and B. cereus in the mussesls are in agreement with the legislation in vigor cares they should be taken with relationship to the storage and the consumption form. The intensity of seasonal interferences was discovered in the microbial count in the water, in which was verified that the board of tides and the index of daily heatstroke had a low negative correlation unlike the index pluviometric it presented high positive correlation