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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.
11

Molecular responses of Giardia lamblia to gamma-irradiation

Lenaghan, Scott. Sundermann, Christine A., January 2008 (has links) (PDF)
Thesis (Ph. D.)--Auburn University, 2008. / Abstract. Includes bibliographical references.
12

A comparative study of giardia and cryptosporidium infections in feedlot cattle in Western Australia and Alberta, Canada /

Ralston, Brenda J. January 2009 (has links)
Thesis (Ph.D)--Murdoch University, 2009. / Thesis submitted to the Faculty of Health Sciences. Includes bibliographical references (leaves 150-162)
13

A comparative study of giardia and cryptosporidium infections in feedlot cattle in Western Australia and Alberta, Canada

brenda.ralston@gov.ab.ca, Brenda Jane Ralston January 2009 (has links)
A comparative study of the parasites Cryptosporidium andersoni and Giardia duodenalis in feedlot cattle in Western Australia (n=502) and Alberta, Canada (n=852) was conducted. The objectives were to determine the prevalence, infection patterns and impact on cattle performance of these protozoan parasites. Utilizing molecular tools G. duodenalis was genotyped and C. andersoni samples were confirmed positive. C. parvum was absent from all cattle sampled in Alberta, Canada and Western Australia, likely due to the advanced age of the cattle being sampled (6-36 months of age). No C. bovis or C. ryanae were observed in the study cattle. C. andersoni was present in 25% of the groups of feedlot cattle sampled in Western Australia with a prevalence range of 0-26% and in all 3 of the Alberta, Canada study groups with a prevalence range of 2.9-12%. All three Alberta, Canada studies collected performance data, however, there was no significant difference between infected and non-infected steers’ ADG in the feedlot. G. duodenalis was present in 83% of the groups sampled in Western Australia with prevalence ranging from 0–22% and all three study groups sampled in Alberta, Canada were positive with a prevalence ranging from 39–82%. The prevalence of G. duodenalis is significantly higher in the Alberta, Canada studies as compared to the Western Australia studies, probably due to climatic factors. Molecular characterization of a small number of the Alberta, Canada G. duodenalis positive samples (10) revealed 30% (3) genotype A, and 70% (7) genotype E. The same characterization of the Western Australia samples (10) showed 20%(2) genotype A, 40% (4) genotype E, 10% (1) genotype B, 10% (1) genotype C, 10% (1) genotype D and 10% (1) genotype B and E. Due to the unusual finding of genotypes C and D in cattle on such a small number of samples this result should be further studied to either confirm or refute the existence of genotypes C and D in cattle. Based on these results 30% of the animals from Alberta, Canada have the potential to be zoonoti (genotypes A and B) and 40% from the Western Australia studies. The results of this study demonstrate that C. andersoni and G. duodenalis are prevalent in the study feedlot cattle in Western Australia and Alberta, Canada however the impact of these parasites was not negative on animal performance in the Alberta, Canada studies where it was measured.
14

Giardia and Cryptosporidium in Pinnipeds from the Gulf of St. Lawrence, Canada

aappelb@meddent.uwa.edu.au, Amber Appelbee January 2006 (has links)
Giardia and Cryptosporidium are protozoan parasites known to cause enteric disease in terrestrial mammals, reptiles and birds. Compared to the abundance of surveys that have examined Giardia and Cryptosporidium in terrestrial wildlife species, very few studies on either parasite have been undertaken on marine mammal species. Studies of shellfish, marine waters and water treatment plants clearly indicate that marine ecosystems are contaminated with Giardia and Cryptosporidium. In spite of these data the extent to which these parasites extend into the marine environment and how they may impact on marine mammal health remains largely unknown. The aim of this thesis was to expand our current knowledge of Giardia and Cryptosporidium in the marine environment and in particular, the harp and hooded seal populations of the Gulf of St. Lawrence, Canada. A large-scale serological survey of a large cohort of serum samples clearly show that, as is the case with terrestrial mammals, Giardia is ubiquitous in the marine environment. Sera positive for G. duodenalis-specific IgG were detected in almost all cetacean and pinniped species examined, and from all regions of the St. Lawrence estuary, Gulf of St. Lawrence and from the Canadian arctic. In the case of harp and hooded seals, they are actively infected with Assemblage A, a zoonotic strain of G. duodenalis and represent a previously unrecognised contributor to the overall environmental parasite burden. The discovery of this variant of Giardia in a phocid host, along with their susceptibility to infection with terrestrial strains of both Giardia and Cryptosporidium, highlight the potential zoonotic transmission from seals to humans through the consumption of uncooked intestines and general animal handling during research or hunting practices. The identification of this zoonotic strain of Giardia in seals also demonstrates the potential for anthropogenic activities such as human sewage treatment and agriculture runoff to be a significant source of contamination for marine mammals.
15

The intestinal immune response to Giardia in the rat /

Waight Sharma, Agnes Phyllis. January 1988 (has links) (PDF)
Thesis (Ph. D.)--University of Adelaide, Dept. of Microbiology and Immunology, 1989. / Includes bibliographical references (leaves 183-228).
16

Waterborne diseases linking public health and watershed data /

Das, Debalina, January 2009 (has links)
Thesis (M.S.)--University of Massachusetts Amherst, 2009. / Includes bibliographical references (p. 81-93).
17

Estudo do limiar de positividade do método imunoenzimático (ELISA) para pesquisa de coproantígenos de Giardia lamblia Stiles, 1915. Sua utilização como exame de controle de cura após terapêutica /

Castanho, Roberto Esteves Pires. January 2004 (has links)
Orientador: João Aristeu da Rosa / Banca: Herminia Yohko Kanamura / Banca: Semiramis Guimarães Ferraz Viana / Banca: Vera Lucy de Santi Alvarenga / Banca: Lúcia Pagliusi Castilho / Resumo: Devido à baixa sensibilidade do exame parasitológico de fezes (EPF) para o diagnóstico laboratorial da giardíase, o método imunoenzimático (ELISA – Enzyme – linked immunosorbent assay) para pesquisa de coproantígenos de Giardia tem sido utilizado, mostrando alta sensibilidade e especificidade. Este trabalho foi desenvolvido com o objetivo de se avaliar a eficácia do ELISA ProSpecT Giardia (Alexon, Inc. BioBrás) anti-GSA65 (antígeno fecal específico de Giardia - peso molecular 65.000 Da) como instrumento de controle de cura da giardíase e o seu limiar de positividade. A contagem de cistos por grama de fezes foi feita utilizando a câmara de Neubauer em amostras positivas para G.lamblia de 100 pacientes. Os resultados mostraram eliminação de 3,6 x 106 cistos por grama de fezes em média. Em gráfico esses resultados desenharam uma curva assimétrica positiva, sugerindo a ocorrência de falso-negativos. Avaliou-se também a eficácia do ELISA anti-GSA65 e o método de Faust e Cols (MFc) em detectar mínimas concentrações de cistos de G. lamblia em amostras fecais. Fezes positivas foram diluídas em fezes negativas de modo a se obter amostras com 100, 1.000 e 10.000 cistos por grama de fezes. O ELISA anti-GSA65 mostrou uma positividade significativamente maior que o MFc. Amostras contendo 10.000 cistos por grama de fezes apresentaram 84,7% de positividade pelo ELISA anti-GSA65 e 34,7% pelo MFc. A eficácia do ELISA anti-GSA65, como instrumento de controle de cura após o tratamento pelo metronidazol em 91 pacientes com giardíase, foi avaliada e mostrou que o ELISA anti-GSA65 pode ser usado para monitorar a cura de pacientes utilizando apenas uma amostra fecal, coletada entre o 4º e 7º dias após o tratamento. Pelo MFc seriam necessárias a coleta de duas ou três amostras. Foi avaliada também comparativamente a eficácia do ELISA anti-GSA65 e do... (Resumo completo, clicar acesso eletrônico abaixo). / Abstract: Due to the low sensitivity of the fecal examination (EPF) in detecting cysts of Giardia lamblia, the imunoenzimatic assay (ELISA enzyme linked immunosorbent assay) to detect G.lamblia coproantigens have been used and have showed high sensibility and specificity. With the ain of evaluating the efficacy of ELISA ProSpecT Giardia (Alexon, Inc. BioBrás) anti-GSA65 (Giardia stool specific antigens - molecular weigh 65.000 Da) as monitoring of the cure of giardiasis and its threshold of positivity it was developed this research. The cysts count per grama of faeces was calculated using Neubauer camera in positive fecal samples for Giardia in 100 patients. It was found a concentration of 3.6 X 106 cyst per grama of faeces as average. In a graph the data draw an assymmetrical positive curve, suggesting occurrence of false negative results. It was evaluated the efficacy of ELISA anti-GSA65, and fecal examination by Faust and colls. procedure (MFc), in detecting minimum concentrations of Giardia cysts in fecal samples. To obtain samples with 100, 1.000 and 10.000 cysts per grama, positive samples were diluted in negative samples. ELISA showed a positivity significative higher than MFc. Samples with 10.000 cystis per grama showed 84,7% of positivity by ELISA anti GSA65 and 34,7% by MFc. The efficacy of ELISA anti-GSA65 as cure monitoring after treatment with metronidazole in 91 patients with giardiasis, was evalued and showed that ELISA anti-GSA65 can be used to monitor the cure of patients, using only single sample of each patients, collected between the 4th and 7th days after treatment, whereas with MFc it would be necessary the exam of two or tree samples. It was also evaluated the efficacy of ELISA-anti-GSA65 and MFc in fecal samples of 96 patients. Considering 38 Giardia true positives and 58 true negatives, the ELISA anti-GSA65 showed 100% of sensibility... (Complete abstract, click electronic address below). / Doutor
18

Developing Lab on a Chip Technology for the Detection and Characterisation of Giardia duodenalis cysts and Cryptosporidium spp. oocysts on Foods

Ganz, Kyle January 2015 (has links)
In the present study methods which can be integrated into a complete lab on a chip system for the detection and characterisation of Giardia duodenalis cysts and Cryptosporidium spp. oocysts from foods were developed and tested. Microfluidic chips, which make use of inertial separation, were designed and fabricated for the concentration and separation of either cysts or oocysts from food particles. These chips were highly specific for their intended target and were shown to be effective when used for artificially contaminated lettuce samples. The quantification by real-time PCR of Cryptosporidium spp. hsp70 mRNA, expressed in response to a heat stress, was assessed as a potential lab on a chip method for the detection of viable oocysts from foods. This method proved to be effective in determining the viability of oocysts in apple cider and the effects of high hydrostatic pressures on the viability of oocysts.
19

Evaluation of a Monoclonal-based EIA for the Detection of Giardia lamblia and the Identification of the Antigen

Boone, James Hunter M.S. 18 May 1998 (has links)
I. A number of commercial enzyme immunoassay (EIA) tests are available for the diagnosis of giardiasis. In a time of rising health-care costs, there is a need for diagnostic tests that are rapid, specific, sensitive and inexpensive. In the first phase of this study, I developed a monoclonal-based EIA, the GIARDIA TEST, with these qualities in mind. This assay's performance characteristics were determined by a comparison study using conventional ova and parasite examination, immunofluorescence antibody test (IFA) and other commercial EIA tests. Studies were done in-house at TechLab, Inc. and at various U.S. medical facilities. Results were statistically analyzed to determine sensitivity (ability of the assay to detect a positive result), specificity (amount of cross-reactivity), predictive positive value (the confidence in a positive result), predictive negative value (the confidence in a negative result) and overall correlation with the reference assay. II. There remain many questions to be answered about the various antigens produced by Giardia lamblia and how they can be utilized as diagnostic markers. In the second phase of this study, I identified and partially characterized the antigen (Ct7 Ag) that reacts with the Ct7 monoclonal antibody (MAb). This MAb is an IgM class mouse immunoglobin that is utilized by the GIARDIA TEST and by an immunofluorence antibody test (IFA) which detects Giardia cysts in water and feces. The results of this study will provide physicians and researchers with detailed information about the Ct7 Ag and why it is a useful marker for giardiasis. / Master of Science
20

Remoção de (oo)cistos de protozoários e de estrogenicidade em sistemas combinados de tratamento de esgoto sanitário / Removal microorganisms, (oo)cysts of protozoa and estrogenicity in combined wastewater treatment systems

Silva, Marcos Schaaf Teixeira da 08 August 2014 (has links)
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.

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