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Circulating tumor cells (CTCs) are the cells that are shed from a primary tumor into the vasculature and circulate in the bloodstream. CTCs may trigger cancer metastasis, which leads to most cancer-related deaths. CTCs are widely studied due to their value in cancer diagnosis, prognosis, and oncology studies. The major challenges with CTCs lie in their extremely low concentration in blood, thus requiring an effective enriching system to enable downstream analyses. The immunomagnetic assay has proved to be a promising CTC detection tool with high sensitivity and throughput. Key factors related to the immunomagnetic assay include the capture rate, which indicates the sensitivity, and distributions of target cells after capture, which impact the cell integrity and other biological properties. In this dissertation, we build a sedimentation model, a partial viscosity model, and a cell-tracking model to address the principle of the immunomagnetic cell separation. We examine the channel orientations and determine the favorable inverted condition. In addition, we develop a micromagnet approach to modulate the in-channel magnetic field toward enhanced cell detection and distribution. Through numerical studies, we calculate the magnetic field generated by the thin-film micromagnets, determine its effective ranges, and demonstrate its value in optimizing cell distribution. In the experimental demonstration, we present two types of micromagnets based on e-beam Ni deposition and inkjet printing technology, respectively. In the screening experiments, the Ni micromagnet integrated system achieves over 97% capture rate. It shows a 14% increase in capture rate, and a 14% improvement in distribution uniformity compared with plain slides. We also successfully isolate CTCs from metastatic cancer patients with the micromagnet assay. The inkjet-printed patterns yield a similarly high capture rate of 103%. With the pixel permanent magnet array, the inkjet patterns further increase the distribution uniformity for 20%. The proposed models lay the theoretical foundations for future modification of the immunomagnetic assay, and the micromagnet-integrated system provides a promising tool for translational applications in cancer diagnose and clinical cancer management. / text

Classical Swine Fever (CSF) is a highly contagious viral disease of swine that causes major losses to pig production. CSF virus is a member of the genus Pestivirus of the family Flaviviridae and is closely related antigenically to other Pestiviruses, Bovine Viral Diarrhoea (BVD) virus and Border Disease (BD) virus. In the Lao People’s Democratic Republic (Laos), CSF has been recognised as a disease that causes significant loss to the smallholder pig sector. However, there exists in Laos a deficiency in fully understanding the epidemiology and impact of CSF, together with limitations in being able to reliably detect CSF outbreaks in a timely manner. (For complete abstract open document)

Orientador: Laurecir Gomes / Tese (doutorado) - Universidade Estadual de Campinas, Instituto de Biologia / Made available in DSpace on 2018-08-09T02:08:34Z (GMT). No. of bitstreams: 1 Oliveira_SilviaBorgesPimentelde_D.pdf: 1168180 bytes, checksum: da1367852d18352f97fbfe0c374bf4c0 (MD5) Previous issue date: 2007 / Resumo: Interações entre o epitélio e o mesênquima/estroma são importantes em diversos estágios da morfogênese, na diferenciação celular e na função geral de diversas glândulas. Na próstata, a função secretora do epitélio nos animais adultos é regulada por andrógenos que tem participação direta na manutenção do estado ativo da glândula. Sabe-se que o endotélio é um dos primeiros elementos prostáticos a responder à eliminação do estímulo androgênico e a responder à sua reposição. Entretanto, a célula endotelial não apresenta receptor para andrógenos, o que leva a crer que a modulação do seu comportamento ocorra indiretamente pela ação de fatores locais produzidos por diferentes tipos celulares. Este trabalho teve como objetivo isolar, caracterizar e cultivar células endoteliais prostáticas, assim como avaliar a possível regulação do seu comportamento por células musculares lisas que correspondem ao principal tipo celular do estroma prostático. Culturas primárias de células endoteliais da próstata de ratos foram obtidas e caracterizadas a partir de sua morfologia e expressão do fator von Willebrand e dos receptores Flk-1 (VEGFR-1) e Flt-1 (VEGFR-2) marcadores específicos de células endoteliais, e de sua habilidade em formar estruturas parecidas com capilares quando cultivadas sobre Matrigel. Não foi observado efeito sobre a proliferação celular quando estas células foram cultivadas na presença de meio condicionado por células musculares lisas, sobre diferentes substratos (plástico, colágeno, matrigel). Entretanto, o meio condicionado pelas células musculares lisas reforçou o efeito de indução da diferenciação em estruturas similares a capilares. Foi também detectado que o meio condicionado inibe a secreção de angiopoietina-1 pelas células endoteliais quando cultivadas sobre colágeno e estimula a secreção de angiopoietina-2 quando as células foram cultivadas sobre Matrigel. Os dados obtidos demonstram que o protocolo utilizado resultou em uma população homogênea de células endoteliais prostáticas e que, as células musculares lisas, produzem fatores solúveis capazes de regular diferencialmente o comportamento das células endoteliais, de acordo com o substrato / Abstract: Interactions between the epithelium and mesenchyme/stroma are important in different stages of morphogenesis, differentiation and function of most glands. In the prostate, the secretory function of the epithelium in adult animals is regulated by androgens, which have direct roles in maintaining prostate activity. It is well known that the endothelium is the first prostatic compartment to respond to androgen deprivation and to its reposition after castration. However, the endothelial cell does not express the androgen receptor and this led us to believe that the altered behavior in response to androgen is modulated by soluble factors produced by other cell types that can sense androgen levels. The objective of this work was to isolated, characterize and culture prostatic endothelial cells, as well as to evaluate its possible regulation by smooth muscle cells, which are the predominant cell type in the prostate stroma. Primary cultures of rat ventral prostate endothelial cells were isolated, maintained in culture and characterized by their morphology, expression of von Willebrand factor, Flk-1 (VEGFR-1) and Flt-1 (VEGFR-2) receptors, and ability to form capillary-like structures on Matrigel. When these cells were cultured in the presence of smooth muscle cell conditioned medium, on different substrata (plastic, collagen, matrigel) there was no variation in cell proliferation. However, the smooth muscle cell conditioned medium reinforced the formation of capillary-like structures in Matrigel. It was also observed that the smooth muscle cell conditioned medium inhibited the secretion of angiopoietin-1 when the cells were cultured on collagen and stimulated the secretion of angiopoietin-2 when the cultured on Matrigel. Altogether, our data indicate that the protocol employed here resulted in a highly homogenous population of prostate-derived endothelial cells and that smooth muscle cells produce soluble factors capable of differentially regulating the behaviour of endothelial cell, as a function of the substratum / Doutorado / Biologia Celular / Doutor em Biologia Celular e Estrutural

O projeto tem como objetivo a detecção e caracterização das células epiteliais circulantes de pacientes com carcinoma de mama no estádio III. Analisou-se a presença ou ausência destas células antes da realização de quimioterapia neoadjuvante. Para tanto, utilizou-se o sistema de enriquecimento de amostras de sangue periférico por meio da marcação intracelular imunomagnética direta, empregando-se microbeads conjugados com citoqueratina e posterior separação imunomagnética. A amostra final, com as células alvo detectadas, foi então quantificada por imunocitoquímica ou citometria de fluxo. Resultados: A reação de imunocitoquímica no sangue periférico foi negativa em todos os casos enquanto que na citometria de fluxo foi positiva em 22/23 casos analisados. Conclusão: A detecção e caracterização de células tumorais circulantes em pacientes com câncer de mama podem vir a se constituir em um novo fator prognóstico, porém, são ainda necessárias novas estratégias para melhor detectá-las. / The aim of this study was to detect and characterize carcinoma cells of patients with breast cancer with clinical stage III analyzing the presence or absence before chemotherapy by enrichment of peripheral blood with super paramagnetic microbeads, using direct Immunomagnetic labeling of intracellular 7/8 cytokeratin. For enrichment, magnetically labeled tumor cells are passed over a high-gradient magnetic positive selection column. Cytospin preparations are made after immunomagnetic enrichment and are examined immunocytochemically (ICC) using an anti-cytokeratin and quantified by flow cytometry (CMF). Results: No cytokeratin positive cells were detected in the 32 peripheral blood of patients of breast carcinoma by ICC and cytokeratin positive cells were detected in the 22 of 23 patients by CMF. Conclusion: These methods of detection and characterization breast carcinoma cells will become useful in the diagnosis and prognosis but is necessary optimization of existing methods.

Lui Yuk Sun. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2001. / Includes bibliographical references (leaves 138-148). / Abstracts in English and Chinese. / Abstract (English) --- p.i / Abstract (Chinese) --- p.iii / Acknowledgements --- p.iv / Abberviations --- p.v / Table of Contents --- p.vii / List of Tables --- p.xiv / List of Figures --- p.xvi / Chapter 1. --- Introduction --- p.1 / Chapter 1.1. --- Bacteriological evaluation of water --- p.1 / Chapter 1.1.1. --- Indicator organisms for water quality monitoring --- p.2 / Chapter 1.1.2. --- Properties defined for indicator organisms --- p.3 / Chapter 1.1.3. --- Example of common indicator organisms --- p.3 / Chapter 1.1.3.1. --- Total coliform group --- p.3 / Chapter 1.1.3.2. --- "Fecal coliform, Escherichia coli" --- p.4 / Chapter 1.1.3.3. --- Fecal Streptococcus --- p.5 / Chapter 1.1.3.4. --- Klebsiella --- p.5 / Chapter 1.2. --- The need for specific detection of waterborne pathogenic organisms --- p.6 / Chapter 1.3. --- Common water-borne pathogenic organisms --- p.7 / Chapter 1.3.1. --- Bacteria --- p.7 / Chapter 1.3.1.1. --- Escherichia coli 0157:H7 --- p.7 / Chapter 1.3.1.2. --- Salmonella typhimurium --- p.11 / Chapter 1.3.1.3 --- Legionella pneumophila --- p.12 / Chapter 1.3.2. --- Protozoa --- p.14 / Chapter 1.3.3. --- Viruses --- p.15 / Chapter 1.4. --- Conventional approaches for pathogens detection --- p.16 / Chapter 1.4.1. --- Examples of conventional detection methods --- p.17 / Chapter 1.4.2. --- Problems related to the conventional detection methods --- p.18 / Chapter 1.5. --- Novel approaches for pathogens detection --- p.19 / Chapter 1.5.1. --- Modifications of media --- p.19 / Chapter 1.5.2. --- Antibody-based methods --- p.20 / Chapter 1.5.3. --- Nucleic acid-based methods --- p.21 / Chapter 1.6. --- Principles of pathogens concentration by filtration and immunomagnetic separation --- p.22 / Chapter 1.7. --- Principles of pathogens detection by polymerase chain reaction --- p.24 / Chapter 1.8. --- Principles of quantitative assay of water-borne pathogens using real-time PCR --- p.26 / Chapter 1.9. --- Aims of this study --- p.28 / Chapter 2. --- Detection of water-borne bacteria by polymerase chain reaction --- p.31 / Chapter 2.1. --- Introduction --- p.31 / Chapter 2.2. --- Materials and Methods --- p.35 / Chapter 2.2.1 --- Bacterial strains --- p.35 / Chapter 2.2.2. --- Bacterial enumeration --- p.35 / Chapter 2.2.3. --- DNA extraction and purification --- p.36 / Chapter 2.2.3.1. --- Boiling method --- p.36 / Chapter 2.2.3.2. --- Protinesae K extraction method --- p.36 / Chapter 2.2.3.3. --- Chelex extraction method --- p.37 / Chapter 2.2.4. --- Targeted sequences --- p.38 / Chapter 2.2.4.1. --- eaeA gene --- p.38 / Chapter 2.2.4.2. --- mdh gene --- p.39 / Chapter 2.2.4.3. --- flaR gene --- p.39 / Chapter 2.2.5. --- PCR amplification --- p.40 / Chapter 2.2.6. --- Gel electrophoresis --- p.41 / Chapter 2.3. --- Results --- p.42 / Chapter 2.3.1. --- Optimization of the PCR --- p.42 / Chapter 2.3.2. --- Sensitivity of PCR detection --- p.42 / Chapter 2.3.2.1. --- Boiling method --- p.42 / Chapter 2.3.2.2. --- Proteinease K method --- p.43 / Chapter 2.3.2.3. --- Chelex method --- p.43 / Chapter 2.3.3. --- Specificity of PCR detection --- p.43 / Chapter 2.3.3.1. --- primers targeted uidA gene --- p.44 / Chapter 2.3.3.2. --- primers targeted mdh gene --- p.44 / Chapter 2.3.3.3. --- primers targeted flaR gene --- p.44 / Chapter 2.4. --- Discussion --- p.57 / Chapter 3. --- Concentration and separation of water-borne bacteria by two-step-filtration and immunomagnetic separation --- p.61 / Chapter 3.1. --- Introduction --- p.61 / Chapter 3.2. --- Materials and Methods --- p.66 / Chapter 3.2.1. --- Bacterial strains --- p.66 / Chapter 3.2.2. --- Bacterial enumeration --- p.66 / Chapter 3.2.3. --- Filtration --- p.67 / Chapter 3.2.4. --- Immunomagnetic separation (IMS) --- p.68 / Chapter 3.2.4.1. --- Antibodies and Magnetic beads --- p.68 / Chapter 3.2.4.2. --- Binding of antibodies to magnetic beads --- p.68 / Chapter 3.2.4.3. --- Immunomagnetic separation of bacteria in seeded samples --- p.70 / Chapter 3.2.5. --- Determine the efficiency of filtration and immunomagnetic separation --- p.70 / Chapter 3.2.6. --- DNA extraction --- p.71 / Chapter 3.2.7. --- Multiplex PCR --- p.71 / Chapter 3.2.8. --- PCR amplification --- p.72 / Chapter 3.2.9. --- Gel electrophoresis --- p.72 / Chapter 3.3. --- Results --- p.73 / Chapter 3.3.1. --- Efficiency of filtration and immunomagnetic separation --- p.73 / Chapter 3.3.2. --- Detection limit of PCR --- p.73 / Chapter 3.3.2.1. --- Filtration and immunomagnetic separation --- p.73 / Chapter 3.3.2.2. --- Influence of background flora --- p.73 / Chapter 3.3.2.3 --- Shing Mun River and Lam Tsuen River --- p.77 / Chapter 3.3.3. --- Multiplex PCR --- p.77 / Chapter 3.4. --- Discussion --- p.91 / Chapter 4. --- Quantitative assay of water-borne pathogens using real-time PCR --- p.94 / Chapter 4.1. --- Introduction --- p.94 / Chapter 4.2. --- Materials and Methods --- p.99 / Chapter 4.2.1. --- Bacteria strains --- p.99 / Chapter 4.2.2. --- Bacterial enumeration --- p.99 / Chapter 4.2.3. --- Primers and Probes --- p.100 / Chapter 4.2.3.1. --- eaeA gene --- p.101 / Chapter 4.2.3.2. --- mdh gene --- p.102 / Chapter 4.2.3.3. --- flaR gene --- p.102 / Chapter 4.2.4. --- Targeted sequences cloning and sequencing --- p.103 / Chapter 4.2.4.1. --- Amplication of targeted sequence by PCR --- p.103 / Chapter 4.2.4.2. --- Purification of PCR product --- p.104 / Chapter 4.2.4.3. --- Ligation with cloning vector --- p.105 / Chapter 4.2.4.4. --- Transformation of E.coli DH5a cells --- p.105 / Chapter 4.2.4.5. --- Plasmid DNA isolation --- p.106 / Chapter 4.2.4.6. --- DNA quantitation and sequencing --- p.107 / Chapter 4.2.5. --- Quantitation determination using real-time PCR --- p.108 / Chapter 4.3. --- Results --- p.110 / Chapter 4.3.1. --- Determination of targeted sequences --- p.110 / Chapter 4.3.2. --- Reading of fluorescence intensity and data analysis --- p.110 / Chapter 4.3.3. --- Sensitivity of real-time PCR --- p.114 / Chapter 4.3.4. --- Specificity of real-time PCR --- p.121 / Chapter 4.3.5. --- Quantitation analysis in seeded samples --- p.121 / Chapter 4.4. --- Discussion --- p.131 / Chapter 5. --- Conclusion and future perspectives --- p.133 / Chapter 6. --- References --- p.138

O projeto tem como objetivo a detecção e caracterização das células epiteliais circulantes de pacientes com carcinoma de mama no estádio III. Analisou-se a presença ou ausência destas células antes da realização de quimioterapia neoadjuvante. Para tanto, utilizou-se o sistema de enriquecimento de amostras de sangue periférico por meio da marcação intracelular imunomagnética direta, empregando-se microbeads conjugados com citoqueratina e posterior separação imunomagnética. A amostra final, com as células alvo detectadas, foi então quantificada por imunocitoquímica ou citometria de fluxo. Resultados: A reação de imunocitoquímica no sangue periférico foi negativa em todos os casos enquanto que na citometria de fluxo foi positiva em 22/23 casos analisados. Conclusão: A detecção e caracterização de células tumorais circulantes em pacientes com câncer de mama podem vir a se constituir em um novo fator prognóstico, porém, são ainda necessárias novas estratégias para melhor detectá-las. / The aim of this study was to detect and characterize carcinoma cells of patients with breast cancer with clinical stage III analyzing the presence or absence before chemotherapy by enrichment of peripheral blood with super paramagnetic microbeads, using direct Immunomagnetic labeling of intracellular 7/8 cytokeratin. For enrichment, magnetically labeled tumor cells are passed over a high-gradient magnetic positive selection column. Cytospin preparations are made after immunomagnetic enrichment and are examined immunocytochemically (ICC) using an anti-cytokeratin and quantified by flow cytometry (CMF). Results: No cytokeratin positive cells were detected in the 32 peripheral blood of patients of breast carcinoma by ICC and cytokeratin positive cells were detected in the 22 of 23 patients by CMF. Conclusion: These methods of detection and characterization breast carcinoma cells will become useful in the diagnosis and prognosis but is necessary optimization of existing methods.

Orientador: Regina Maura Bueno Franco / Tese (doutorado) - Universidade Estadual de Campinas, Instituto de Biologia / Made available in DSpace on 2018-08-10T22:08:19Z (GMT). No. of bitstreams: 1 CantusioNeto_Romeu_D.pdf: 1288923 bytes, checksum: 6747f006dc8fe56fe9a7284e80649fe0 (MD5) Previous issue date: 2008 / Resumo: A veiculação hídrica tem sido considerada uma das principais vias de transmissão de giardiose e criptosporidiose sendo implicada na ocorrência de vários surtos de gastroenterites, em vários países nos últimos anos. Diante deste panorama, no Brasil foi emitida Portaria 518/04 (Ministério da Saúde), que recomenda a pesquisa destes protozoários em água de consumo humano. Por este motivo, o objetivo deste estudo foi realizar um estudo comparativo entre as metodologias de concentração já existentes: Filtração em Membrana (FM) e Floculação em Carbonato de Cálcio (FCC), tecendo uma análise crítica das mesmas e verificando-se a sua aplicabilidade em amostras naturais de água superficial do Rio Atibaia. Este estudo foi conduzido em duas etapas: na primeira, foram realizados 52 experimentos, visando analisar o desempenho dos métodos propostos determinando-se a precisão inicial em amostras de água reagente inoculadas com suspensões comerciais de cistos e oocistos Easy Seed® (Biotecnology Frontiers, Austrália), aplicando-se ou não a etapa de purificação mediante o uso da separação imunomagnética. Quando foram avaliadas amostras do rio Atibaia, a suspensão comercial de cistos e oocistos utilizada para a contaminação artificial foi Color Seed® (Biotecnology Frontiers, Austrália). Em uma segunda etapa, um total de 36 experimentos foi conduzido com o objetivo de se avaliar o comportamento dos mesmos métodos frente a fatores interferentes, característicos da matriz de água bruta superficial, entre eles a turbidez. Nos experimentos controle com amostra de água reagente, a metodologia de FM recuperou mais organismos (21,5 % dos oocistos e 25,0 % dos cistos), quando comparada com a metodologia de FCC (5,3 % e 5,8 % dos oocistos e cistos, respectivamente). A inclusão da etapa de purificação por separação imunomagnética (IMS) não resultou num aumento na recuperação de cistos e oocistos nestas metodologias (FM e FCC). Nos experimentos com amostras de água do Rio Atibaia, de uma maneira geral, a metodologia de FCC apresentou melhor desempenho de recuperação dos organismos e quando incluída a etapa de IMS, uma melhora ocorreu apenas para a recuperação de cistos de Giardia spp. Quando avaliada amostras de água bruta superficial do rio Atibaia em condições de turbidez até 50 NTU a etapa de purificação por IMS acarretou uma maior eficiência de recuperação de cistos de Giardia spp. e oocistos de Cryptosporidium spp., para as duas metodologias de concentração. Quando a turbidez das amostras foi superior a 50 NTU, uma melhora da recuperação ocorreu apenas para Cryptosporidium spp, utilizando-se o método de FM. Assim, ambas as metodologias avaliadas, mostraram-se eficientes para serem aplicadas em um monitoramento desses protozoários em amostras hídricas, mesmo em situações de alta turbidez. A etapa de purificação pela separação imunomagnética nem sempre apresentou um ganho na recuperação dos organismos e, as variações nos valores de recuperação para ambos os protozoários, são inerentes aos protocolos utilizados e também associados à matriz analisada. A FM é indicada pela praticidade, tempo e resultados, podendo auxiliar para o conhecimento da ocorrência destes patógenos e assim, minimizar a possibilidade de sua transmissão mediante veiculação hídrica / Abstract: The waterborne transmission route of giardiosis and criptosporidiosis has been considered the major one, causing the occurrence of several gastroenteritis outbreaks in several countries in the last years. Looking to this panorama, was published in Brazil the Governmental Decree 518/04 (Health Department), that recommends the research of these protozoa in water samples. For this reason, the goal of this study was to accomplish a comparative study between Membrane Filtration (MF) and Calcium Carbonate Flocculation (FCC) concentration methodologies, doing a critical analysis of both and verifying its apply in natural samples of Atibaia River superficial water. Two stages took place: in the first one, 52 experiments were carried out, aiming to analyze the performance of the methods proposed, determining the initial precision in samples of reagent water inoculated with commercial suspensions of cysts and oocysts (Easy Seed®-Biotecnology Frontiers Australia), applying or not the purification step by Immunomagnetic Separation. When natural water samples were evaluated, the commercial suspension of cysts and oocysts utilized for the artificial contamination was (Color Seed®-Biotecnology Frontiers Australia). In a second step, 36 experiments were carried out aiming to evaluate the behavior of the methods facing interferential factors, peculiar of the superficial raw water matrix, as turbidity. In the trial control with reagent water sample, the FM methodology recovered more organisms (21.5% of the oocysts and 25.0% of the cysts), in comparison to the FCC methodology (5.3% of the oocysts and 5.8% of the cysts). The purification step by Immunomagnetic Separation (IMS) did not show an improvement in the recovery of cysts and oocysts in these methodologies (FM and FCC). In the experiments with natural water performance of the organisms and when IMS step was included, an improvement occurred just for the recovery of Giardia spp. cysts. When superficial raw water of Atibaia river samples with turbidity up to 50 NTU were evaluated, the purification step by IMS showed higher efficiency in the recovery of Giardia spp. cysts and Cryptosporidium spp. oocysts, for both concentration methodologies. When the turbidity of the sample was over 50 NTU, a recovery improvement occurred just for Cryptosporidium spp, using the FM method. Thus, both methodologies showed efficiency in monitoring these protozoa in water samples, even in situations of high turbidity. The purification step by Immunomagnetic Separation not always showed gain in the recovery of the organisms and the variations in the values of recovery for both protozoa are inherent to the protocols that were used and also associated to the analyzed matrix. However, the FM method is indicated for its practicability, time and results, being able to help the knowledge of the occurrence of these pathogens and minimize the possibility of its transmission by waterborne route / Doutorado / Parasitologia / Doutor em Parasitologia

Orientador: Regina Maura Bueno Franco / Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Biologia / Made available in DSpace on 2018-08-21T08:57:58Z (GMT). No. of bitstreams: 1 BonideOliveira_ClarisseMaria_M.pdf: 6327674 bytes, checksum: 05abbfdb0fdd48f248f326f48096fc33 (MD5) Previous issue date: 2012 / Resumo: O solo, principalmente quando melhorado com matéria orgânica proveniente de lodo de estação de tratamento de esgoto e/ou fezes humanas e de animais, pode se tornar importante fonte de veiculação de doenças por abrigar diversos parasitos. Estes, por serem amplamente dispersos no ambiente, podem gerar problemas de saúde pública. Como o solo é uma das principais rotas de transmissão desses organismos, este trabalho teve como objetivo - a partir dos protocolos descritos na literatura para a detecção de cistos de protozoários e ovos de helmintos em solos - avaliar as metodologias mais eficientes e escolher um método visando a padronização de um protocolo eficaz na detecção de cistos de Giardia e ovos de helmintos. Foram analisadas as variáveis: Homogeneização: vórtex por 2 minutos; agitador magnético por 10 minutos; homogeneização em mixer rotatório durante 30 minutos e homogeneização manual por 5 minutos; Soluções Dispersantes: 1% 7X ICN; glicina 1 M; 0,1M tetrassódio pirofosfato e 1% Tween 40; Filtração: ausência da etapa de filtração e , filtração em peneira, para os ensaios referentes aos ovos; Soluções de Purificação: sulfato de zinco (densidade 1,18), solução saturada de cloreto de sódio; sacarose (densidade 1,33 para protozoários e 1,3 para helmintos) e polietileno glicol 60%, além da separação imunomagnética (apenas para ensaios com cistos); Força Centrífuga Relativa: 650 x g durante 5 minutos (apenas para ovos); 1050 x g durante 10 minutos e 1050 x g durante 20 minutos. As amostras de solo foram contaminadas artificialmente com um número conhecido (5 x 10² ou 10³) de cistos de Giardia spp e de ovos de Ascaris suum. Comprovou-se, previamente aos experimentos, a negatividade do solo coletado quanto aos cistos de Giardia, mediante a realização da PCR, e flutuação em solução de sacarose, para ovos de helmintos. Verificou-se que, a homogeneização do solo com o ICN 7X em mixer rotatório é o processo mais adequado para cistos e ovos, a separação imunomagnética é a melhor forma de purificação para cistos e a solução de sacarose para ovos. As forças centrífugas relativas mais apropriadas são 650 x g durante 5 minutos para ovos e 1050 x g durante 10 minutos para cistos. Após a padronização da metodologia foi avaliada a aplicabilidade desta em solos irrigados por efluente de esgoto hospitalar tratado e em areia do filtro de tratamento deste esgoto. Foram encontrados cistos em ambas as matrizes. O uso desta metodologia efetiva permite o melhor controle da transmissão de parasitoses / Abstract: The soil, especially when enriched with organic matter from sludge sewage treatment plant or human and animal feces, may become an important source of diseases transmissions for holding several parasites. These parasites, for being widely spread in the environment, may cause public health problems. As the soil is one of the main routes for pathogens transmission, this study aimed to - from the protocols described in scientific literature for the detection of protozoan and helminth eggs in soil - evaluate the most effective methodologies and standardize a method to recover cysts and helminth eggs from soil. The following variables were analyzed: vortex Homogenization for 2 minutes, magnetic stirrer for 10 minutes, homogenization in rotary mixer for 30 minutes, and manual shaking for 5 minutes; Dispersion Solutions such as 1% ICN 7X, 1M glycine, 0.1M tetrasodiumPPi and1% tween 40; Filtration: the absence of filtration step, and filtering through a sieve, eggs testing; Purifying Solutions such as zinc sulphate (1,18density) saturated sodium chloride, sucrose (1,33 density for cysts and 1,3 density for eggs), polyethylene glycol 60% and immunomagnetic separation (just for cysts testing); Relative Centrifugal Force: 650 x g for 5 minutes (for eggs); 1050 x g for 10 minutes, 1050 x g for 20 minutes. Soil samples were artificially infected with a know number (5 x 10² or 10³) of Giardia spp cysts and Ascaris suum eggs. The negativity of the collected soil regarding the Giardia cysts was proved previously to the experiments, through PCR, and by flotation in sucrose solution for helminth eggs. It was verified that, the soil homogenization with ICN 7X in rotary mixer is the most efficient process for cysts and eggs, the immunomagnetic separation is the best purifying way for cysts and the sucrose solution for eggs. The most appropriated relative centrifugal force are 650 x g for 5 minutes for the eggs and 1050 x g for 10 minutes for the cysts. After the standardization of the methodology, its applicability was evaluated in soils irrigated with hospital treated wastewater and in the sand filter of this sewage treatment. Cysts were found in both matrices. The usage of this effective methodology allows better controlling of parasitosis transmission / Mestrado / Parasitologia / Mestre em Parasitologia

The diagnostic methods implemented at the Canadian Food Inspection Agency for the detection of Shiga toxin producing E. coli (STEC) are time consuming and tedious, taking up to 5 days before a positive sample can be confirmed. The goal of this project was to streamline the detection procedure for serogroup O157 and 6 important non-O157 serogroups of STEC. Following a short enrichment step (4-6 hrs), two approaches were considered: (1) the filtration of enrichment culture through a gradient of filtration membranes (decreasing pore sizes), followed by capture using specific monoclonal antibody (mAb)-coated Dynabeads, and detection via fluorescence microscopy, (2) the addition of enrichment culture into a flow through system consisting of a column packed with large polystyrene beads (≥ 100 μm) coated with specific mAbs for capture. The results indicate that the filtration approach can only be applied to simpler food matrices. However, at least 100 CFU of the target STEC could be recovered using the filtration system following 4 hrs of enrichment of these matrices spiked with ≤ 15CFU of the target STEC. Similar capture results were obtained in the second approach using specific mAbs immobilized on covalently coupled protein G polystyrene beads and diluted enrichment media. A combination of these strategies together with immunofluorescence microscopy (IMS) and polymerase chain reaction (PCR) could provide diagnostic laboratories with a means to confirm a positive sample within 2 days of testing.