Yersinia enterocolitica are potentially pathogenic bacteria transmitted through the fecal oral route. Typical disease symptoms include those associated with gastrointestinal disease, although infection can also lead to more serious and invasive illnesses, particularly in sensitive populations. Previous surveys have detected Y. enterocolitica in surface water in various parts of the world, and studies have found drinking untreated water to be a possible risk factor for Y. enterocolitica infection. Methods available for the detection of Y. enterocolitica have been developed primarily for food and clinical samples and have not been tested extensively with water. More commonly used methods include culture based isolation of Yersinia spp. and polymerase chain reaction (PCR) based detection of Y. enterocolitica. Reports suggest that culture based methods available for the isolation of Y. enterocolitica may not be effective for environmental samples. Strain isolation using culture based methods is important, so that further subtyping information can be obtained for epidemiological investigations. In contrast, PCR based detection is more rapid, of higher throughput, can be highly specific and can target pathogenic strains within a species. The overall objective of this work was to evaluate culture based and PCR based methods for the detection of Y. enterocolitica in water, and to examine its prevalence in the Grand River watershed in Southwestern Ontario, Canada. Surface water in this watershed is used to provide all or part of the drinking water for approximately 500,000 people, as well as for recreational purposes. It is also one of the most heavily impacted watersheds in Canada by both agricultural and urban activities. Culture based studies compared two selective agars and four enrichment broths. Results showed that Cefsulodin Irgasan Novobiocin (CIN) agar and modified tryptic soy broth (mTSB) had greater potential for recovering Y. enterocolitica from surface water. Consequently, enrichment in mTSB followed by growth on CIN agar was used to isolate Yersinia from the Grand River. Yersinia strains were isolated from 52 out of 200 (26 %) surface water samples collected over a 17 month period. No seasonal trends were observed in isolation rates. Species isolated were typically considered to be non pathogenic species, although recent evidence suggests they may have potential virulence to humans. The majority of these strains have been found by other groups in surveys of aquatic environments. PCR methods developed targeted two Y. enterocolitica virulence genes: the ail gene, located in chromosomal DNA; and the yad A gene, located on a virulence plasmid. In surface water collected from the Grand River, the ail gene target was detected in 121 samples out of 319 (38 %) over a 29 month period and the yadA gene target was detected in 44 samples out of 206 (21 %) over a 20 month period. Both genes were detected more frequently when the water temperatures were colder. PCR-based studies conducted were quantitative, which has not previously been done with water samples. The median and maximum concentrations in samples positive for the ail gene were 40 and 2,000 cells/100 mL, and in samples positive for the yadA gene were 32 and 3,276 gene copies/100 mL, respectively. Overall results demonstrated that culture based methods are less sensitive than PCR based detection methods for specific detection of pathogenic Y. enterocolitica, suggesting that previous culture based surveys may have underestimated their potential prevalence. Furthermore, potentially pathogenic Y. enterocolitica may be present in the Grand River watershed. While Y. enterocolitica is relatively easily inactivated by traditional disinfection methods used in drinking water treatment processes, it is possible their presence poses a concern for recreational users and individuals drinking untreated water. This study suggests that further investigation is necessary to evaluate possible health risks associated with the occurrence of potentially pathogenic Y. enterocolitica in the Grand River. This work assists with the development of methods and information gathering for an emerging waterborne pathogen that has not been surveyed in the Grand River watershed, nor quantitatively surveyed in any water previously. Findings provide important information for drinking water providers and public health investigations.

The overall objective of the work described in this thesis was to examine the effects of both waterborne and dietary routes of exposure to fathead minnow (Pimephales promelas) when exposed to complex metal mining mixtures. This was conducted using a 21-day, multi-trophic, short-term fathead minnow (FHM) reproductive bioassay. The endpoints that were measured were used to assess the effects on multiple levels of biological organization (sub-organismal to population endpoints). The first phase of this research was conducted in situ using environmentally realistic concentrations of 3 separate metal mining effluents [20% surface water effluent (SWE), 30% mine water effluent (MWE), 45% process water effluent (PWE)] from Sudbury, Ontario, Canada. Metals were analyzed in several media (water, sediments) and tissues (biofilm, Chironomus dilutus, female fathead minnow carcass, ovaries, liver and gills). The incorporation of the biofilm (primary producers) into the bioassay also added another level of organization that was novel to this study. Significant increases in metal concentrations were observed in the water and biofilm tissues in all treatments [SWE, MWE, PWE], compared to reference. Cobalt and nickel increased significantly in C. dilutus tissues in SWE (1.4-fold and 1.5-fold respectively), and copper and selenium in PWE (5.2-fold and 3.3-fold respectively), however no significant increases occurred in MWE compared to reference. There were no significant increases in metal concentrations in female FHM tissues (carcass, liver, gonads, gills) in any of the treatments, suggesting that metal bioavailability was reduced. Cumulative number of eggs per female per day increased significantly (+127%) after exposure to SWE and decreased significantly (-33%) after exposure to PWE when compared to the reference fish. Mean total number of days to hatch was also reduced in PWE compared to reference. In order to gain a better understanding of the routes of exposure causing toxicity in FHM, the second phase of this research examined the effects of exposure through diet, through water or through both using a fully factorial food exposure design in a laboratory setting. In this experiment we pre-exposed C. dilutus to both 45% PWE and laboratory control water until they reached the 3rd-4th instar stage of development (approximately 21 days) where they were collected and frozen until the start of the FHM reproductive bioassay. We further examined the role of food quality on fish toxicity by assessing differences between multi trophic (where fish were fed both a live and frozen diet of C. dilutus) in the laboratory. This research was conducted at the Toxicology Centre in Saskatoon, Saskatchewan, Canada. The results showed that significant effects were observed when fish were fed a live diet versus a frozen diet. Condition factor and body weight increased, although inconsistent effects were observed for liver somatic index (LSI) in fathead minnows in both experiments when exposed to one or both routes of exposure. Cumulative total egg production and cumulative spawning events were both significantly affected by both waterborne and dietborne exposures with the greatest effects seen in the multi-trophic streams and particularly when fish were fed a live diet. This significance of this research has demonstrated the importance of including both routes of exposure when assessing effects of mine effluent. This research also shows that the artificial stream technology is a useful tool in isolating the effects of a particular point source input (metal mining mixtures) when a system is highly confounded. The results suggest that under environmentally relevant exposure conditions, trophic transfer and live diet may lead to greater reproductive effects and increased fish toxicity. This also suggests that trophic transfer is an important route of exposure that is virtually impossible to attain using typical laboratory bioassay techniques (food-borne study using artificial diets or waterborne exposures only).

Protection of potable water supplies demands a better understanding of the factors controlling migration of disease causing bacteria in subsurface environments. In this study, the migration behaviour of the waterborne pathogenic microorganisms Escherichia coli O157:H7 and Yersinia enterocolitica was investigated in water saturated granular systems. Both facultative bacteria were grown under aerobic and anaerobic conditions and further acclimatized to a microaerophilic or fully aerated environment for 21 h. Experiments were conducted using laboratory-scale packed columns over controlled extreme dissolved oxygen (DO) concentrations. The observed differences in the transport potential of these pathogens were found to depend strongly on the antecedent growth conditions under the tested environmental settings as well with the environmental DO in certain conditions. Further microbial characterization using cell titrations and FTIR spectroscopy gave a greater insight on the source of the surface charge that was found to dominate the attachment phenomena in sand packed columns. Techniques also revealed a probable role of other cell surface macromolecules (LPS) that could account for non-DLVO behaviour. The results illustrate the importance of considering physicochemical conditions relevant to the natural subsurface environment when designing laboratory transport experiments as evidenced by variations in microbe migration as a function of the DO under growth and acclimation. / Keywords: bacterial adhesion, bacterial transport, DLVO, physicochemical characterization, dissolved oxygen, porous media.

The contamination of drinking water by microbial pathogens is recognized as one of the most pressing water supply problems of our day. To minimize the impact of pathogens and parasites on the environment and public health, accurate methods are needed to evaluate their presence and concentration. Although various techniques exist to detect certain pathogens in water (e.g., immunofluorescence or PCR techniques), these are time- and labor-intensive. A direct, real-time method for detection and quantification of target organisms would thus be very useful for rapid diagnosis of water safety. A quartz crystal microbalance with dissipation monitoring (QCM-D) based biosensor for detection of waterborne pathogens (i.e., Escherichia coli O157:H7) was developed. The detection platform is based on the immobilization of affinity purified antibodies onto gold coated QCM-D quartz crystals via a cysteamine self-assembled monolayer. The results show that the optimal sensor response is the initial slope of the dissipation shift. A highly log-log linear response is obtained for detection of E. coli O157:H7 over a broad range of cell concentration from 3 x 105 to 1 x 109 cells/mL. The prepared biosensor also exhibits a log-log linear working range from 107 to 109 cells/mL for E. coli K12 D21, a non-pathogenic model organism. The biosensor also shows satisfactory selectivity using Bacillus subtilis . To our knowledge, this is the first study demonstrating the use of the slope of the dissipation shift as a sensor response when using QCM-D technology. / Keywords: Biosensor, QCM-D, E. coli O157:H7, polyc1onal antibodies, dissipation slope, cysteamine, self-assembled monolayer

Waterborne pathogen presence caused by fecal pollution is a leading cause of morbidity and mortality worldwide. In developed countries, this problem can result in waterborne outbreaks. Research suggests that there is a need for better fecal indicators because current methods (total coliforms and E. coli) are insufficient. This study investigated Bacteroidales 16S rRNA markers as a microbial source tracking tool in an agricultural watershed. Correlations between pathogens and markers were also investigated. Water quality monitoring was conducted following assay validation of ruminant-, bovine-, human-specific, and universal Bacteroidales markers. Results revealed a positive relationship between E. coli and the universal marker. Ruminant- and bovine-specific marker detection was associated with increased runoff due to precipitation; however, the human associated marker was not detected. Furthermore, no correlations between Campylobacter, Salmonella, or E. coli O157:H7 could be made. Consequently, these techniques have potential to become a powerful tool; however, further research is needed

This study was conducted to understand the interactions between irrigation water management and water quality (agro-ecological interactions). The Uda Walawe basin, in Southern Sri Lanka was chosen as the study area. Fluctuations in water quality, especially microbiological water quality, affect human health. Since the source of domestic water (drinking and washing) in this region is from the irrigation system, there is a concern for the human health effects. All the potential water sources and the water use habits of the community were identified. The water quality of these sources was then monitored for a period of 5 months (August--December 2000). Second, the water management of the Uda Walawe irrigation system was linked to the differences in water quality. The best quality water was found to come from the shallow wells (seepage water from the irrigation system). Both quantity and quality of the water were shown to fluctuate with canal construction (earthen or concrete) and irrigation water management.

In this study, waterborne silicone-acrylic resin was produced by incorporating silane coupling agent onto the acrylic main chain by emulsion polymerization. After applying different emulsion polymerization processes, batch polymerization was selected to obtain the resultant resin. Thus finding the optimum conditions by investigating the parameters of monomer ratios, initiators, concentrations of initiators, temperature and time, the novel resin was synthesized. Water-dispersed silicone-acrylic resin was produced using butyl acrylate, butyl methacrylate, methyl methacrylate, 3-methacryloxypropyltrimethoxysilane and acrylic acid as a hydrophilic monomer. 2,2&#039 / -azobis[2-(2-imidazolin-2yl)propane]dihydrogen chloride as thermal initiator and t-butyl hydroperoxide / sodiummetabisulfite as redox couple initiator were selected as the best effective initiators for the production of silicone-acrylic resin. The reaction temperature of the preparation of silicone-acrylic resin was taken as 50&amp / #61616 / C maximum to prevent gelation and agglomeration. To understand the effect of silane coupling agent on the properties of the resin, a new resin was synthesized which did not contain any silane coupling agent and the properties of both resins were determined by FTIR spectroscopy, thermal analysis and mechanical tests. Their physical properties were also determined. The addition of 3-methacryloxypropyltrimethoxysilane to the main chain increased the hardness and the gloss values but slightly decreased the abrasion resistance value of the silicone-acrylic resin. All the samples showed superior flexibility. The produced polymer which contains silane coupling agent showed excellent adhesion properties on glass and metal plates.

Thesis (PhD.(Medical Virology)--Faculty of Health Sciences)-University of Pretoria, 2007. / Includes bibliographical references.

A contaminação de água subterrânea por coliformes fecais em propriedades rurais está diretamente relacionada com o saneamento básico rural oferecido, assim como as doenças de veiculação hídrica contraídas por essas populações. Esta pesquisa analisa a contaminação da água de consumo humano proveniente de poços, considerando os índices de potabilidade descritos na Portaria do Ministério da Saúde nº 2.914 e na Resolução CONAMA nº 398. Tem-se como estudo de caso uma área rural no município de Caxias do Sul, estado do Rio Grande do Sul, inserida na da bacia hidrográfica do arroio Marrecas. Foram realizados estudos por meio de informações contidas em relatórios técnicos, normatizações federais e bibliografias especializadas, para contextualização, conceituação e teorização de saneamento básico rural, qualidade e contaminação da água subterrânea, doenças de veiculação hídrica e poços. Mediante o uso do estimador de densidade Kernel, levantou-se o número de residências a serem entrevistadas. Durante o processo de entrevistas, averiguou-se a existência de saneamento básico rural nas propriedades, porém a maioria dos poços não estavam protegidos do acesso e/ou de serem contaminados por animais. Isto justificou a necessidade de realização de análise da qualidade da água subterrânea consumida por meio de poços particulares. Os resultados das entrevistas diagnosticaram uma população ambientalmente consciente sobre a preservação do meio e sobre a qualidade da água consumida. Contudo, os resultados das análises indicaram que a água ingerida estava contaminada por coliformes, assim como também houve relatos de doenças de veiculação hídrica, confirmando o saneamento deficiente em algumas propriedades rurais. / The contamination of groundwater by fecal coliforms in rural properties is directly related to the available basic rural sanitation, as well as to water-borne diseases contracted by these populations. This research analyzes the contamination of potable well water, applying the potability indicators described in the Ministry of Health Directive Nº. 2914 and the Brazilian Environment Council (CONAMA) Resolution No. 398. A rural area in the city of Caxias do Sul, Rio Grande do Sul, located within the hydrographic basin of the Marrecas stream, was used as the case study. Studies were conducted by using information contained in technical reports, federal guidelines, and specialized bibliographies, for the context, concepts and of basic rural sanitation, quality and contamination of groundwater, waterborne diseases and wells. The number of households to be interviewed was determined by using the Kernel density estimator. During the interview process, the existence of basic rural sanitation was verified in the properties, however, a majority of the wells were not protected from the access and/or from being contaminated by animals. This justified the need for conducting the analysis of the quality of groundwater consumed by way of individual wells. The interviews resulted in the diagnostic of an environmentally conscious population, aware of preserving the environment and of the quality of water consumed. However, the results of the analyses indicated that the drinking water was contaminated by coliforms, and there were also reports of waterborne diseases, confirming the poor sanitation in some rural properties.

Orientador: Maria Jacira Silva Simões / Banca: José Paschoal Batistuti / Banca: Jonas Contiero / Resumo: A diarréia do viajante é o problema de saúde, mais comum, associado ao turista em termos de freqüência e impacto econômico contribuindo para a perda de rendimentos obtidos pelo turismo, em países em desenvolvimento. O objetivo da presente pesquisa foi identificar os agentes etiológicos mais freqüentes, nos surtos de doença transmitida por alimentos e/ou água em núcleos receptores turísticos, conhecer a sazonalidade e caracterizar a população segundo a idade e os alimentos suspeitos. Baseou-se nas notificações enviadas à Divisão de Doença de Transmissão Hídrica e Alimentar (DDTHA), Centro de Vigilância Epidemiológica (CVE), Secretaria Estadual de Saúde (SES) do Estado de São Paulo, no período 2002 a 2005 e informações das Vigilâncias Sanitárias da Direção Regional de Saúde (DIR). Os núcleos receptores turísticos selecionados foram: cidade de São Paulo e alguns municípios do interior como Águas de São Pedro, Campinas, Campos de Jordão, Franca, Jundiaí, Piracicaba, Pirassununga, Ribeirão Preto, São José dos Campos, São José do Rio Preto e do litoral como Guarujá, Peruíbe, Praia Grande, Santos e Ubatuba. Os resultados mostraram que o núcleo receptor turístico cidade de São Paulo, notificou 304 surtos, 3382 casos/doentes e dois óbitos. Do interior foram notificados 116 surtos e 8016 casos/doentes e três óbitos. Do litoral foram notificados 11 surtos, 253 casos/doentes e três óbitos, compreendendo um total de 431 surtos, sendo 129.340 comensais, 11.651 casos/doentes e 8 óbitos. Os agentes etiológicos mais freqüentes foram : vírus (58,08%), bactérias (72,72%), protozoários (4,67%), helmintos (0,83%), fungos (0,15%) e produtos químicos (0,12%). A freqüência dos agentes etiológicos foi: Rotavirus 31,86%; coliformes 28,38%; Salmonella sp. 13,55% (Salmonella Enteritidis 5,08% e Salmonella Typhimurium 2,88%)... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Travelers' diarrhea is the most common travel-related health problem in terms of frequency and economic impact. Travelers' diarrhea also contributes to loss of income from tourism in developing countries. The aim of the present study was to find the principle pathogens involved in outbreaks of food poisoning in tourist centers, and discover in what season the outbreaks occur, and age of the population. This study was based on informations sent to Divisão de Doença de Transmissão Hídrica e Alimentar (DDTHA), Centro de Vigilância Epidemiológica (CVE), Secretaria Estadual de Saúde (SES) do Estado de São Paulo and Vigilâncias Sanitárias da Direção Regional de Saúde (DIR) from 2002 - 2005. The tourist centers selected for the study were: São Paulo city; Águas de São Pedro, Campinas, Campos de Jordão, Franca, Jundiaí, Piracicaba, Pirassununga, Ribeirão Preto, São José dos Campos, São José do Rio Preto; Guarujá, Peruíbe, Praia Grande, Santos, and Ubatuba. The results showed that São Paulo city reported 304 outbreaks, 3,382 cases/disease and two deaths. From the interior of the state of São Paulo (116 outbreaks), 8016 cases/disease and 3 deaths were registered. From the coast (11 outbreaks), 253 cases/disease and 3 deaths were registered. In total there were 431 outbreaks, 129,340 persons exposed, 11,651 cases/disease and 8 deaths. The etiological agents were bacteria (72.72%), virus (58.08%), protozoa (4.67%), nematodes (0.83%), fungi (0.15%) and chemical products (0.12%). The frequency of causative pathogens was: Rotavirus 31.86%, coliforms 28.38%... (Complete abstract click electronic access below) / Mestre