Fecal indicator bacteria (FIB) such as Escherichia coli and enterococci are used to assess microbiological water quality in recreational waters worldwide. FIB are used with the assumption that their presence correlates with that of fecal-associated pathogens in recreational waters. In aquatic habitats, several factors can interfere with the predictive relationship between FIB and pathogens including extended survival of FIB in secondary habitats such as sediment, vegetation and sand. Furthermore, many biotic (e.g. predation from bacterivorous protozoa and competition from indigenous bacteria) and abiotic factors (e.g. temperature, salinity, ultraviolet (UV) light irradiation, and nutrient availability) can influence the fate of FIB and pathogens associated with gastrointestinal tracts of animals (enteric pathogens) in secondary habitats. The relative importance of these factors is not well characterized, thus limiting our knowledge on the efficacy of FIB as indicators of fecal contamination and microbial pathogens in water. The studies presented in this dissertation investigated the influence of biotic (predation from bacterivorous protozoa and competition from indigenous bacteria) and abiotic factors (e.g. nutrient availability) on the survival of FIB (E. coli and Enterococcus faecalis) and pathogens (E. coli O157 and Salmonella enterica) in aquatic habitats. Water and sediment samples were collected from a fresh water river source (Hillsborough River, Tampa, FL) and used to prepare a series of outdoor mesocosm experiments. In each experiment, biota treatments were varied to include various combinations of predation and competition, both or neither. Manipulation of biota treatments involved disinfection of water and baking of sediments to remove indigenous microbiota, or addition of cycloheximide or kanamycin to diminish the effect of predation from natural protozoa or competition from indigenous bacteria respectively. Bacterial levels in all experiments were monitored over a five day period. In the mesocosms investigating the effect of predation and competition on FIB (E. coli and Ent. faecalis) and a pathogen (E. coli O157:H7), predation had a detrimental effect on the survival of the FIB and pathogen in the water column but only influenced the survival of the FIB in the sediment. Unlike predation, competition from indigenous bacteria influenced the survival of E. coli but not Ent. faecalis in both water and sediment. The second set of mesocosms investigated the effect of predation on two motile and non-motile enteric bacteria types (E. coli O157 and S. enterica), each with a motile and non-motile counterpart. An allochthonous predation source (Tetrahymena pyriformis) was added into the mesocosms to supply a consistent level of predation. Motility had a significant positive effect on the survival of S. enterica in the water and sediment but had negative significant effect for E. coli O157 in sediment only. Motility also played a more important role in the sediment compared to predation while predation played a more important role in the water column for both bacteria types. The third study compared the relative effects of predation, competition and nutrients on the survival of E. coli. Natural waters (not amended with nutrients) served as a baseline condition to which organic nutrients were added in two increments. Significant interactions among predation, nutrients and competition (all possible combinations) were observed. Interactions between predation and nutrients as well as competition and predation also accounted for the greatest effects (10% and 8% respectively). The interaction between predation and competition was particularly pronounced at the highest nutrient level. These studies reveal that predation, competition and nutrients are all important factors in the survival of FIB and enteric bacteria in water and sediment, and provide new observations on the relative magnitude of these effects. I show that survival characteristics of FIB and enteric bacteria in secondary habitats can vary depending on bacteria type (FIB or pathogen), location (water or sediment), prey characteristics (motile or non-motile) and specific environmental stressor present (predation, competition or nutrients). The findings of this dissertation provide new insights on the ecology of FIB and enteric bacteria in secondary habitats and underscore the importance of biotic and abiotic factors as determinants of the fate of FIB and enteric bacteria in secondary habitats.

Lic.-avh. (sammanfattning) Stockholm : Karolinska institutet, 2006. / Härtill 2 uppsatser.

Thesis (Ph. D.)--Ohio State University, 2008 / Title from first page of PDF file. Includes bibliographical references (p. 136-152).

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Made available in DSpace on 2014-10-09T12:42:49Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T14:08:23Z (GMT). No. of bitstreams: 1 06121.pdf: 5715540 bytes, checksum: ca3626a80eb62b032ade08a2bfe344c4 (MD5) / Dissertacao (Mestrado) / IPEN/D / Instituto de Pesquisas Energeticas e Nucleares - IPEN/CNEN-SP

Made available in DSpace on 2016-08-12T18:48:41Z (GMT). No. of bitstreams: 0 Previous issue date: 2015-02-26. Added 1 bitstream(s) on 2016-08-12T18:50:55Z : No. of bitstreams: 1 000865143.pdf: 1222502 bytes, checksum: 6d7d7cfc6cf6e5880416ce873a338cad (MD5) / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / Muitas espécies de protozoários podem causar gastroenterite aguda ou crônica em seres humanos e são altamente prevalentes nas populações residentes nos países em desenvolvimento, onde a transmissão é favorecida devido a condições precárias de higiene e escassa disponibilidade de água potável. No entanto, a infecção assintomática e o poliparasitismo também são comumente observados nessas populações. Neste trabalho, investigou-se a prevalência de protozoários intestinais em duas colônias de pescadores, Porto Said (PS) e Santa Maria da Serra (SM), situadas ao longo do rio Tietê, no Estado de São Paulo. As colônias não dispõem de serviços públicos básicos como: vias públicas, fornecimento de água e luz e saneamento básico. Todos os colonos (n = 88 em PS, e n = 38 em SM) coletaram três amostras de fezes, e todos eram assintomáticos no momento da coleta. Para obter informações sobre as possíveis vias de transmissão, amostras fecais de 49 cães (38 de PS e 11 de SM) e 28 amostras de água do rio foram coletadas (16 de PS e 12 de SM). As amostras fecais humanas e caninas foram analisadas por microscopia e PCR para detectar e caracterizar os protozoários Giardia duodenalis, Blastocystis spp., Dientamoeba fragilis e Cryptosporidium spp. Diante dos resultados obtidos, Blastocystis spp. foi o parasita mais prevalente nas amostras humanas (45,4% em PS e 71% em SM), seguido por D. fragilis (13,6% em PS e 18,4% em SM) e G. duodenalis (18,2% em PS e 7,9% em SM), já Cryptosporidium spp. não foi detectado na população humana. Além disso, G. duodenalis foi detectado em quatro cães (10,5%) em PS e dois cães (18,2%) em SM, enquanto que um único cão foi detectado com Cryptosporidium canis. Nas 28 amostras de água previamente processadas pelos métodos de filtração e separação imunomagnética e examinadas por microscopia de fluorescência, oocistos de Cryptosporidium e cistos de Giardia não foram... / Several species of protozoa cause acute or chronic gastroenteritis in humans, worldwide. The burden of disease is particularly high among children living in developing areas of the world, where transmission is favored by lower hygienic standards and scarce availability of safe water. However, asymptomatic infection and polyparasitism are also commonly observed in poor settings. Here, we investigated the prevalence of intestinal protozoa in two small fishermen villages, Porto Said (PS) and Santa Maria da Serra (SM), situated along the river Tietê in the State of São Paulo, Brazil. The villages lack basic public infrastructures and services, such as roads, public water supply, electricity and public health services. Multiple fecal samples were collected from 88 individuals in PS and from 38 individuals in SM, who were asymptomatic at the time of sampling and had no recent history of diarrheal disease. To gain insights into potential transmission routes, 49 dog fecal samples (38 from PS and 11 from SM) and 28 river water samples were also collected. All samples were tested by microscopy and PCR was used to genotype isolates of Giardia duodenalis, Blastocystis spp., Dientamoeba fragilis and Cryptosporidium spp. By molecular methods, the most common human parasite was Blastocystis spp. (prevalence, 45% in PS and 71% in SM), followed by D. fragilis (13.6% in PS, and 18.4% in SM) and G. duodenalis (18.2% in PS and 7.9% in SM); Cryptosporidium spp. were not detected. Further, G. duodenalis was found in 4 dogs (10.5%) in PS and 2 dogs (18.2%) in SM, whereas a single dog was found infected with Cryptosporidium canis. River water samples processed by filtration and immunomagnetic separation and examined by fluorescent microscopy, were negative for Cryptosporidium oocysts and Giardia cysts. Sequencing of the barcoding region of the small subunit ribosomal gene revealed large genetic variation among Blastocystis isolates, with subtypes (STs) that ... / FAPESP: 11/52100-3

Atualmente há um grande interesse em estudos voltados para sistema de tratamento de esgoto sanitário. Isso se deve principalmente pela presença de microrganismos e substâncias que podem interferir na saúde humana e ambiental. Dentre os microrganismos patogênicos responsáveis por transmissão de doenças estão os protozoários Giardia spp. e Cryptosporidium spp. No que se refere às substâncias nocivas à saúde humana e ambiental podem ser citados os desreguladores endócrinos que agem sobre o sistema endócrino de homens e animais causando efeitos adversos. Baseado na importância destes estudos, o presente trabalho teve por objetivo avaliar a eficiência de remoção de protozoários patogênicos - Giardia spp. e Cryptosporidium spp. e da atividade de estrogenicidade em processos de tratamento de esgoto sanitário constituídos por reator UASB, sistema de lodos ativados e filtro de areia. Também foram avaliados os padrões de qualidade dos efluentes do reator UASB e sistema de lodos ativados utilizando sulfato de alumínio e cloreto férrico. A combinação dos processos biológicos sequenciais apresentou robustez em termos de remoção de matéria orgânica, microrganismos indicadores e (oo)cistos. A desinfecção com cloro mostrou-se eficiente em inativar os microrganismos indicadores: coliformes totais e Escherichia coli. A atividade estrogênica, avaliada pelo teste YES, foi maior no efluente do lodo ativado e do filtro de areia devido à conjugação dos compostos estrogênicos no esgoto bruto. Detectou-se toxicidade à levedura utilizada no teste YES (Saccharomyces cerevisae), principalmente nas menores diluições, a qual interferiu na expressão da estrogenicidade impossibilitando o cálculo em termos de concentração equivalente de 17β-estradiol. / Currently there is great interest in studies related to the wastewater treatment system. This is mainly for the present of microorganisms and substances that can interfere with human and environmental health. Among the pathogens responsible for diDEse transmission are protozoa Giardia spp. and Cryptosporidium spp. With regard to substances harmful to human and environmental health can cite endocrine disrupters that act on the endocrine system of humans and animals causing adverse effects. Based on the importance of these studies, the present study aimed to evaluate the efficiency of removal of pathogenic protozoa - Giardia spp. and Cryptosporidium spp. - Activity and estrogenicity in processes of wastewater treatment consisting of UASB reactor, activated sludge system and sand filter. We also evaluated the quality standards of the effluent of the UASB reactor and activated sludge system using aluminum sulfate and ferric chloride. The combination of hardiness sequential biological processes presented in terms of removal of organic matter, microorganisms and indicators (oo) cysts. The chlorine disinfection proved effective in inactivating microorganisms indicators: total coliforms e Escherichia coli. The estrogenic activity, assessed by the YES assay, was higher in the effluent of the activated sludge and sand filter due to a combination of estrogenic compounds in raw sewage. Was detected toxicity to the yeast used in the YES assay (Saccharomyces cerevisiae), mainly in the lower dilutions, which interfered with the expression of estrogenicity it impossible to calculate in terms of an equivalent concentration of 17β-estradiol.

Made available in DSpace on 2014-10-09T12:28:37Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T13:57:33Z (GMT). No. of bitstreams: 0 / A leishmaniose visceral (LV) é um problema de saúde pública, que tem incidência elevada em crianças. No ano de 2009 a cidade de Araguaína - Tocantins foi a cidade com maior número de casos de LV. Este estudo tem como objetivo identificar a expansão geográfica da LV no município de Araguaína, identificar o perfil epidemiológico dos casos de LV atendidos no Hospital de Doenças Tropicais (HDT) de Araguaína, principalmente de crianças e pessoas maiores de 60 anos, que representam população de risco para a gravidade da doença. A partir do número de casos notificados de 2004 a 2009, foram elaborados mapas sobre a evolução da distribuição geográfica da LV nos bairros de Araguaína, também foi realizado estudo epidemiológico, laboratorial e evolutivo dos casos de LV em crianças e pessoas acima de 60 anos atendidas no HDT. Dentre as crianças, nas menores de um ano, também foi avaliado o quadro clínico. Foram utilizados os dados do Sistema de Informação de Agravos de Notificação (SINAN) dos casos notificados no HDT, nos anos de 2004 a 2009. Foram registrados 983 casos, sendo 391 de crianças (39,8%) de zero a cinco anos e destas 71 notificações de menores de um ano (18%). Neste mesmo período foram notificados 22 casos de LV em maiores de 60 anos (2,2%). A maioria das notificações foi da cidade de Araguaína (62,5%). Os casos de LV ocorreram na maioria dos bairros de Araguaína, iniciaram nos bairros centrais e depois se expandiram para a periferia, onde fizeram o maior número de casos. Com relação ao sexo dos pacientes, houve uma discreta incidência no sexo masculino, principalmente na faixa etária dos maiores de 60 anos. O diagnóstico de LV teve confirmação laboratorial na maioria dos casos, porém o exame utilizado foi na maioria das vezes o exame sorológico, que não é o melhor método diagnóstico. O tratamento inicial da maioria dos pacientes foi com o antimoniato pentavalente. A maioria dos pacientes evoluiu para a cura. Este trabalho demonstra a expansão geográfica da LV no município de Araguaína, atingindo principalmente crianças. / Dissertacao (Mestrado) / IPEN/D / Instituto de Pesquisas Energeticas e Nucleares - IPEN-CNEN/SP