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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
121

Prävalenz intestinaler Protozoeninfektionen in Ijinga Island, Tansania / Prevalence of intestinal protozoan infections in Ijinga Island, Tanzania

Mechler, Clemens Thomas January 2020 (has links) (PDF)
Intestinal infections with pathogenic protozoa may cause severe disease and remain a neglected problem in regions with inadequate sanitation and hygiene standards, especially in sub-Saharan Africa. Unfortunately, very little data about the prevalence of these infections in risk groups exist from the region. The present study was therefore conducted to assess the prevalence of intestinal protozoan infections in a representative population sample on Ijinga Island, north-western Tanzania. Methods: This was a cross-sectional study which was carried out in 2016 as part of the on-going SchistoControl pilot project on Ijinga Island, north-western Tanzania. A single stool sample was collected from 357 participants and examined microscopically for presence of trophozoites or cysts of intestinal protozoan parasites. In addition, real-time polymerase chain reaction (qPCR) was used to determine the species of intestinal protozoa. Results: Based on microscopy and qPCR, the prevalence of Giardia intestinalis infection was 12% and 15.1%, respectively. Based on microscopy, the prevalence of Entamoeba histolytica/Entamoeba dispar was 26.1%. However, through species identification using qPCR, 21.8% of the study participants were carrying non-pathogenic E. dispar and none of them was infected with E. histolytica. Conclusion: Intestinal protozoan infections are common among the population in the study area. The detection of these infections in different age groups indicates a poor hygienic standard in the community. Improvement in water, sanitation, hygiene and public health education on hand washing will help in controlling these infections. / Intestinale Infektionen mit pathogenen Protozoen können schwere Erkrankungsbilder verursachen und stellen eine oftmals vernachlässigte Problematik, vor allem in Regionen mit geringen Sanitär- und Hygienestandards, dar. Dies betrifft insbesondere südlich der Sahara gelegene Länder. Hier existieren leider keine oder nur unzureichende Prävalenzdaten, was zum Teil auch auf die inadäquaten diagnostischen Möglichkeiten zurückzuführen ist. Die Übertragung erfolgt fäkal-oral über verunreinigte Nahrungsmittel sowie kontaminiertes Trinkwasser und kann symptomatische und asymptomatische, akute und chronische Infektionen hervorrufen. Methoden: Es handelt sich um eine Querschnittsstudie, die 2016 im Rahmen des laufenden SchistoControl-Pilotprojekts auf der Insel Ijinga im Nordwesten Tansanias durchgeführt wurde. Es wurden Stuhlproben von 357 Teilnehmern gesammelt und mikroskopisch auf Trophozoiten oder Zysten von intestinalen Protozoen untersucht. Zusätzlich wurde die Realtime-Polymerasekettenreaktion (qPCR) zur Speziesdifferenzierung verwendet. Ergebnisse: Basierend auf Mikroskopie und qPCR betrug die Prävalenz von Giardia intestinalis 12% bzw. 15,1%. Basierend auf der Mikroskopie betrug die Prävalenz von Entamoeba histolytica / Entamoeba dispar 26,1%. Durch Speziesdifferenzierung mittels qPCR waren jedoch 21,8% der Studienteilnehmer positiv für E. dispar und keiner positiv für E. histolytica. Schlussfolgerung: Intestinale Protozoeninfektionen sind in der Bevölkerung des Studienortes häufig. Der Nachweis dieser Infektionen in verschiedenen Altersgruppen weist auf einen geringen Hygienestandard in der Gemeinde hin. Eine Verbesserung der Wasser-, Sanitär-, Hygienestruktur und des Gesundheitsbewusstseins wird zur Kontrolle dieser Infektionen beitragen.
122

Prevalencia de Giardia spp. en roedores (Rattus spp.) procedentes de un zoológico de Lima Metropolitana

Casana Palacios, Cynthia Lila January 2018 (has links)
Se determina la prevalencia de Giardia spp. en ratas urbanas “Rattus rattus” y “Rattus norvegicus” capturadas en un zoológico de Lima Metropolitana, además , se evaluó la asociación del parasito con las variables especie, sexo y edad de estos roedores. Se atraparon 127 roedores (Rattus spp.), usando trampas especiales (tipo“Tomahawk”). Se siguió un estricto control de bioseguridad para la manipulación y recolección de muestras de estos animales, sirviendo de referencia los protocolos proporcionados por el “Centro de Enfermedades Infecciosas y Prevención de Atlanta (CDC)”. Los datos que se tomaron en cuenta para este estudio fueron especie, sexo y edad de los roedores, y las muestras recolectadas provinieron del recto. La conservación se hizo utilizando formol al 10% y posteriormente fueron procesadas en el Laboratorio de Parasitología de la FMV-UNMSM. La técnica empleada para determinar la presencia de Giardia spp. fue la de Ritchie modificado, siendo muestra positiva aquella en que se hallara la presencia de quiste o trofozoito de Giardia spp. Como resultado se halló una prevalencia de Giardia spp. de 5.5 ± 0.04% (7/127); y se hayo una prevalencia del 2.1% del genero Rattus rattus (1/48) y 7.6% en Rattus norvergicus (6/79). Mediante la prueba de Chi cuadrado se encontró que No existe asociación con una significancia de “(p > 0,05)” entre la presencia de Giardia spp. y las variables especie, sexo y edad, por lo que la prevalencia de Giardia spp. en ratas urbanas en el presente estudio, es baja. Sin embargo, es de consideración tomar en cuenta la posibilidad de transmisión de enfermedades parasitarias de este animal a una población vulnerable como son niños y ancianos, trabajadores y animales del zoológico. / Tesis
123

Proteomická analýza organel parazitických protist / Organelle proteomics of parasitic protists

Jedelský, Petr January 2017 (has links)
Advances in DNA sequencing led to a technological breakthrough, that allowed analyzis of complete genomes including those of parasitic protists Trichomonas vaginalis and Giardia intestinalis . These organisms are studied not only for their clinical importance, but also from the evolutionary point of view for their adaptation to anaerobic environment. Genome sequencing and annotations of predicted proteins alone did not bring detail view into functioning of their mitochondrion related organelles ­ in G. intestinalis mitosomes, not­participating in energetic metabolism, in T. vaginalis hydrogenosomes, producing molecular hydrogen and ATP by means of substrate phosphorylation. Traditional methods based on a fractionation by ultracentrifuging in density gradient and subsequent biochemical and enzymological analyzes were extended by one­ and two­dimensional electrophoresis with subsequent identification of proteins by mass spectrometry. Methods of multidimensional separation of peptides produced by specific proteolysis of a complex mixture...
124

Biogeneze mitosomů Giardia intestinalis / Biogenesis of Giardia intestinalis mitosomes

Voleman, Luboš January 2018 (has links)
7 ABSTRACT Mitochondria of opisthokonts undergo permanent fusion and fission throughout the cell cycle. Keeping these two processes in balance is vital for various aspects of mitochondrial and cellular homeostasis. Both mitochondrial fusion and division mechanisms are controlled by highly conserved dynamin-related GTPases that are present in all kingdoms of life. The aspects of mitochondrial dynamics outside the opisthokonts is, however, almost completely unexplored phenomenon. In our work, we introduced a tool for live imaging of the reduced forms of mitochondria into model organisms Giardia intestinalis and Trichomonas vaginalis, anaerobic protist parasites from the Excavata supergroup of Eukaryotes. Using this technique, we investigated the dynamics of the mitosomes, the simplest forms of mitochondria, of G. intestinalis. The division of mitosomes is restricted to Giardia mitosis and is absolutely synchronized with the process. The synchrony of the nuclear and the mitosomal division persists also during the encystation of the parasite. Surprisingly, the sole dynamin-related protein of the parasite seems not to be involved in mitosomal division. However, throughout the cell cycle mitosomes associate with the...
125

Studies on the immunobiology of murine giardiasis using hybridoma technology

Butscher, Wayne Gregory. January 1992 (has links)
No description available.
126

How is encystment regulated in Giardia intestinalis

Tsarukyanova, Iryna G. 16 May 2012 (has links)
No description available.
127

ISOLATION AND IDENTIFICATION OF FRESHWATER BACTERIA ANTAGONISTIC TO <i>GIARDIA INTESTINALIS</i>

REVETTA, RANDY PRIMO 03 April 2006 (has links)
No description available.
128

Feline Parasitism:  Parasite Prevalence and Evaluation of New Immunoassays for Giardia and Cryptosporidium

Monti, Katelynn A. 13 September 2017 (has links)
Cats are infected with a variety of internal parasites, some of which are zoonotic. Therefore, being able to effectively detect and determine prevalence of internal parasites in cats is important for both feline and human health. Some parasites are easier to detect than others. Diagnosing Giardia duodenalis and Cryptosporidium spp. can be difficult because cysts and oocysts shed in the feces are small, shed intermittently, and require a trained technician to consistently identify them. As a result, infections with these protozoan parasites can be missed. Fecal immunoassays detect antigens in feces and can have increased sensitivity when compared to traditional microscopic techniques, but still do not detect every infection. The current reference standard is an immunoassay known as the direct immunofluorescent assay, but it requires expensive equipment and a long incubation period. As a result, two prototype lateral flow fecal immunoassays, the Cryptosporidium EZ VUE and Giardia EZ VUE, designed by TECHLAB® Inc were evaluated for the ability to detect G. duodenalis and Cryptosporidium spp. infections in cats because they are cheap, easy to use, easy to store and easy to interpret. In addition, samples were examined using a 33% zinc sulfate (ZnSO4) centrifugal fecal flotation procedure and the MERIFLUOR® Cryptosporidium/Giardia direct immunofluorescent assay (IFA), which served as the reference test. Other internal parasites found on the centrifugal fecal flotation with zinc sulfate were recorded to determine prevalence. Both EZ VUE fecal immunoassays demonstrated potential in diagnosing infections in cats when compared to centrifugal fecal flotation and the reference. Additionally, a variety of other internal parasites were identified. This included several potentially zoonotic species including Spirometra mansonoides, Ancylostoma sp. and Toxocara cati, which was also the most commonly identified species of parasite. Additionally, it was determined that several factors may contribute to higher prevalence of parasites especially in cats with the status of stray or feral. / M. S.
129

Interactions protozoaires – moule zébrée (Dreissena polymorpha) : implication en biosurveillance sanitaire et environnementale / Interaction protozoa - zebra mussel (Dreissena polymorpha) : interest for sanitary and environmental biomonitoring

Palos Ladeiro, Mélissa 10 October 2014 (has links)
L'évaluation de la contamination des cours d'eau par les agents parasites protozoaires est fondamentale puisqu'on estime qu'une personne sur deux dans le monde est ou a été infectée par une zoonose d'origine parasitaire. Les trois principaux parasites responsables d'épidémies hydriques sont Cryptosporidium parvum, Giardia duodenalis et Toxoplasma gondii. Actuellement, seule la matrice eau est utilisée pour analyser la présence de ces parasites dans l'environnement aquatique. Peu reproductible et chronophage, cette méthode ne permet pas de mettre en place une surveillance de routine. Le projet de thèse propose l'utilisation de la moule zébrée, Dreissena polymorpha, comme un nouvel outil complémentaire pour évaluer la qualité biologique des milieux d'eau douce. Au travers d'expérimentations combinant différentes approches in vivo, ex vivo et in situ, le potentiel de la dreissène à accumuler les parasites protozoaires ainsi que leurs cinétiques d'accumulation dans les tissus ont été déterminés. Utilisée comme espèce sentinelle des contaminations chimiques, l'effet d'un stress biologique dû aux protozoaires a été évalué au laboratoire sur les cellules clefs de l'immunité des bivalves, les hémocytes. Ainsi, le projet permet de placer l'organisme Dreissena polymorpha dans une double stratégie de biosurveillance : une biosurveillance sanitaire liée à l'utilisation de la dreissène en tant que vecteur de parasites considérés comme enjeux de santé publique et une biosurveillance environnementale liée à la compréhension des facteurs de confusion avec les réponses biologiques utilisées comme biomarqueurs. / Assessment of the water biological contamination by protozoa is crucial since one in two person of the world population is or has been infected by a parasitic zoonosis. The main protozoa responsible of waterborne outbreaks are Cryptosporidium parvum, Giardia duodenalis and Toxoplasma gondii. Currently, protozoa detection is only based on water analysis. Irrelevant and time consuming, water analysis do not permit accurate biomonitoring. These project aims to use the freshwater mussel, Dreissena polymorpha, as a new complementary tool for biological quality analysis of freshwater. Through in vivo, ex vivo and in situ experiments, we determine the utility of zebra mussel for protozoa accumulation and their accumulation pattern within mussel tissues. Already use as a sentinel specie for chemical contamination, biological stress caused by protozoa has been determined in laboratory experiments on key cells of bivalve immunity, the hemocytes. Hence, Dreissena polymorpha could be involved in a twofold biomonitoring tactics: sanitary biomonitoring related to the use of zebra mussel as vector to protozoa with public health issue and environmental biomonitoring on understanding of the confounding factors in biological responses used as biomarkers.
130

Ocorrência e remoção de cistos de Giardia spp. e oocistos de Cryptosporidium spp. em Reatores Anaeróbios de Fluxo Ascendente e Manta de Lodo (UASB) operando com esgoto sanitário e águas negras simuladas / Occurrence and removal of Giardia spp. and Cryptosporidium spp. in Upflow Anaerobic Sludge Blanket Reactors (UASB) operating with sewage and simulated black water

Fernanda Queiroz Valdez 09 September 2016 (has links)
As doenças de veiculação hídrica são uma preocupação no mundo todo, e tem aumentado cada vez mais o interesse nos estudos relacionados aos protozoários Cryptosporidium spp. e Giardia spp.. A presença de protozoários em águas de abastecimento está vinculada ao lançamento de esgoto nos mananciais, de modo que o tratamento de esgotos sanitários é de extrema importância para reduzir o risco de surtos de protozooses. Este trabalho avaliou a ocorrência e a possibilidade de remoção de cistos de Giardia spp. e oocistos de Cryptosporidium spp. em dois reatores UASB, um piloto e um em escala plena, operados com esgoto sanitário e um TDH de aproximadamente 8h, e um reator UASB piloto, operado com água negra simulada e um TDH aproximado de três dias. Nos dois reatores operados com esgoto sanitário as remoções foram semelhantes. A média de DQO total afluente, no reator piloto e no de escala plena, foi de 271 e 410 mg/L, respectivamente, e as remoções médias de DQO foram de 50,62 e 45,80%, respectivamente. Com relação aos exames parasitológicos, quase não houve remoção em ambos os reatores e, na maior parte dos casos, o número de (oo)cistos detectados no efluente foi maior do que no afluente. Já no reator piloto operado com águas negras, foram observadas remoções mais elevadas. A DQO total afluente desse reator variou de 837 a 3269 mg/L e a remoção média observada foi de 71,22%. Neste reator também foram observadas maiores remoções de (oo)cistos, sendo que a remoção de cistos Giardia spp. variou de 67,73 a 93,69% e, em um dos ensaios, foi observada uma remoção de 70% de oocistos de Cryptosporidium spp. Acredita-se que o melhor desempenho desse reator se deve ao seu elevado tempo de detenção hidráulico. Foi avaliada, ainda, a ocorrência de (oo)cistos no lodo dos três reatores, resultando em valores bastante elevados, da ordem de 105 cistos/g de massa seca, em todos eles. De qualquer modo, em todos os reatores avaliados, mesmo o que apresentou as maiores eficiências, o efluente ainda apresentava altas concentrações de poluentes, necessitando de um pós-tratamento para a remoção dos remanescentes de matéria orgânica, sólidos e patógenos. / The waterborne diseases are a concern worldwide, and has grown more and more interest in studies related to the protozoa Cryptosporidium spp. and Giardia spp. The presence of protozoa in drinking water is related to the release of sewage in water sources. So that, the sewage treatment is extremely important to reduce the risk of outbreaks protozoa. This study evaluated the occurrence and the possibility of removal of Giardia spp. and Cryptosporidium spp. in two UASB reactors, a pilot and a full-scale, operated with sewage and a HRT of 8 hours, approximately, and a pilot UASB reactor, operated with simulated black water and an approximate HRT of three days. Removals were similar in both reactors operated with sewage. The average influent total COD, in pilot and full scale reactors, was 271 and 410 mg/L, respectively, and the average COD removal were 50.62 and 45.80%, respectively. With the parasitological test, there was almost no removal in both reactors and, in most cases, the number of (oo)cysts detected in the effluent was higher than in the influent. In the pilot reactor operated with black water, higher removals were observed. The total COD influent of this reactor ranged from 837 to 3269 mg/L and the average removal observed was 71.22%. In this reactor (oo)cysts removals were also higher, and the removal of Giardia cysts ranged from 67.73 to 93.69%, and in one of the trials, a 70% removal of Cryptosporidium spp was observed. It is believed that the best performance of this reactor is due to its high hydraulic retention time. The occurrence of (oo)cysts in the sludge of the three reactors was also evaluated, resulting in very high values of the order of 105 cysts/g of dry weight, in all of them. Anyway, in all this reactor, even the one with the highest efficiency, the effluent still had high concentrations of pollutants, necessitating a post treatment for the removal of remaining organic matter, solids and pathogens.

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