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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.
41

Técnica de filtragem em membrana para avaliação quantitativa da aglutinação de linhagens de E. Coli em mananoligossacarídeo / Membrane Filtration Technique for Quantitative Evaluation of Agglutination of E. Coli Lines in Mananoligosacarídeo

PEREZ, Paula Marioto 26 April 2017 (has links)
Submitted by Adriana Martinez (amartinez@unoeste.br) on 2018-02-08T12:18:06Z No. of bitstreams: 1 Paula Marioto.pdf: 1937657 bytes, checksum: 854d1496600ea2225a02ba82fc76a39d (MD5) / Made available in DSpace on 2018-02-08T12:18:07Z (GMT). No. of bitstreams: 1 Paula Marioto.pdf: 1937657 bytes, checksum: 854d1496600ea2225a02ba82fc76a39d (MD5) Previous issue date: 2017-04-26 / The objective of this study was to standardize a quantitative technique to evaluate the in vitro capacity of agglutination of different mannanoligosaccharides (MOS) to the strain of Escherichia coli isolated from cases of infantile diarrhea in children from 0 to 5 years of age. The research for the expression of fimbria Type 1 present in the isolates was performed by the microhemoagglutination test. For the oligosaccharide agglutination assays three MOS markers were extracted from S. cerevisae, groups 1, 2 and 3, filtered through a microfilter, later diluted for surface sowing in chromogenic Agar E. coli. For microscopic evaluation of binder capacity of the MOS were subjected to slide agglutination tests. In order to estimate the total bacterial count (CBT), the counts of the three-plate set were calculated. Assumptions of homogeneity of variances and normality of data were validated, respectively, by the Levene and Shapiro-Wilk test. Homozygous variables were compared by analysis of variance in one way (ANOVA one-way), with contrasts by the Tukey method. Heterocedastic variables were compared with one-way ANOVA with application of the Welche contrast contrasts by the Games-Howell method. Correlations between CBTs, Titres hemagglutinants, diameters and areas of the globules were evaluated by the Pearson correlation test. All analyzes were conducted in software R, considering probability of error type 1 = 5% Of the 30 strains tested, 25 (83.3%) expressed hemagglutinating capacity with titers ranging from 1: 4 to 1: 16. The results suggest that the MOS showed effective action on the agglutination of the bacteria, since the estimates of CBTs of the strains treated with MOS were inferior the counts of the pure sample. The degree of agglutination may vary according to the composition of the MOS, since product 1 showed higher CBTs than the others, indicating that the agglutinated beads were not able to retain bacteria in the pores of the filters similarly to products 2 and 3. It was observed significant correlation between mannose-sensitive haemagglutination and MOS agglutination for products 1 and 2, suggesting that the intensity of bacterial agglutination may be related to the expression of type 1 fimbriae. It is concluded that the filtration and culture technique can be used to evaluate different degrees of agglutination of MOS products and the amount of bacteria retained in the filters appears to be more related to the expression of mano-sensitive type 1 fimbriae than to the sizes of the globules produced. / O objetivo deste estudo foi padronizar uma técnica quantitativa para avaliar a capacidade in vitro de aglutinação de diferentes mananoligossacarídeos (MOS) à cepa de Escherichia coli isoladas de casos de diarreia infantil, de crianças de 0 a 5 anos de vida. A pesquisa para a expressão da fímbria tipo 1 presente nos isolados foi realizada pelo teste de microhemoaglutinação. Para realização dos ensaios de aglutinação de oligossacarídeos utilizou-se três marcas comerciais de MOS, extraídos de S. cerevisae, grupos 1, 2 e 3, filtrados através de um microfiltro, posteriormente diluídos para semeadura superficial em Ágar cromogênico E. coli. Para avaliação microscópica da capacidade aglutinante do MOS foram submetidas a testes de aglutinação em lâmina.Para estimar a contagem bacteriana total (CBT), calculou-se a média das contagens do conjunto de três placas. Pressupostos de homogeneidade de variâncias e normalidade de dados foram validados, respectivamente, pelo teste de Levene e Shapiro-Wilk. Variáveis homocedásticas foram comparadas por análise de variância em uma via (ANOVA one-way), com contrastes pelo método de Tukey. Variáveis heterocedásticas foram comparadas com ANOVA one-way com aplicação da correção de Welche contrastes pelo método de Games-Howell. As correlações entre CBTs, Títulos hemaglutinantes, diâmetros e áreas dos glóbulos foram avaliados pelo teste de correlação de Pearson. Todas as análises foram conduzidas no software R, considerando-se probabilidade de erro tipo 1= 5%. Das 30 cepas testadas, 25 (83,3%) expressaram capacidade hemaglutinante com títulos variando entre 1:4 e 1:16. Os resultados sugerem que o MOS apresentou ação efetiva na aglutinação das bactérias, visto que as estimativas de CBTs das cepas tratadas com MOS foram inferiores as contagens da amostra pura. O grau de aglutinação pode variar segundo a composição do MOS, visto que o produto 1 apresentou CBTs superiores aos demais, denotando que os glóbulos aglutinados não foram capazes de reter bactérias nos poros dos filtros de forma similar aos produtos 2 e 3.Observou-se correlação significativa e negativa entre a hemaglutinação sensível à manose e aglutinação de MOS para os produtos 1 e 2, o que sugere que intensidade da aglutinação por bactérias pode estar relacionada a expressão de fímbrias do tipo 1. Conclui-se que a técnica de filtragem e cultura pode ser utilizada para avaliar diferentes graus de aglutinação de produtos a base de MOS e a quantidade de bactérias retidas nos filtros parece estar relacionada mais com a expressão de fímbrias tipo 1 mano-sensíveis do que com os tamanhos dos glóbulos produzidos.
42

Two-Phase Microfluidic Systems for High Throughput Quantification of Agglutination Assays

Castro, David 04 1900 (has links)
Lab-on-Chip, the miniaturization of the chemical and analytical lab, is an endeavor that seems to come out of science fiction yet is slowly becoming a reality. It is a multidisciplinary field that combines different areas of science and engineering. Within these areas, microfluidics is a specialized field that deals with the behavior, control and manipulation of small volumes of fluids. Agglutination assays are rapid, single-step, low-cost immunoassays that use microspheres to detect a wide variety molecules and pathogens by using a specific antigen-antibody interaction. Agglutination assays are particularly suitable for the miniaturization and automation that two-phase microfluidics can offer, a combination that can help tackle the ever pressing need of high-throughput screening for blood banks, epidemiology, food banks diagnosis of infectious diseases. In this thesis, we present a two-phase microfluidic system capable of incubating and quantifying agglutination assays. The microfluidic channel is a simple fabrication solution, using laboratory tubing. These assays are incubated by highly efficient passive mixing with a sample-to-answer time of 2.5 min, a 5-10 fold improvement over traditional agglutination assays. It has a user-friendly interface that that does not require droplet generators, in which a pipette is used to continuously insert assays on-demand, with no down-time in between experiments at 360 assays/h. System parameters are explored, using the streptavidin-biotin interaction as a model assay, with a minimum detection limit of 50 ng/mL using optical image analysis. We compare optical image analysis and light scattering as quantification methods, and demonstrate the first light scattering quantification of agglutination assays in a two-phase ow format. The application can be potentially applied to other biomarkers, which we demonstrate using C-reactive protein (CRP) assays. Using our system, we can take a commercially available CRP qualitative slide agglutination assay, and turn it into a quantitative High Sensitivity-CRP test, with a lower detection limit of 0.5 mg/L using light scattering. Agglutination assays are an incredibly versatile tool, capable of detecting an ever-growing catalog of infectious diseases, proteins and metabolites. A system such as that presented in this thesis is a step towards being able to produce high throughput microfluidic solutions with widespread adoption.
43

Seroprevalence and associated risk factors of Toxoplasma gondii infection in domestic animals in the OR Tambo District, South Africa

Tagwireyi, Whatmore Munetsi January 2016 (has links)
Toxoplasma gondii is a single-celled parasite that has a wide range of hosts including humans. A cross-sectional survey was conducted to investigate T. gondii seroprevalence and associated risk factors in small ruminants, pigs, poultry and cats in the Oliver Reginald Tambo District in the Eastern Cape in South Africa between June 2016 and October 2016. Household-level and animal-level data were collected using a close-ended questionnaire. One sample of each present species was collected in each household. The Toxoreagent ®, Mast Group, United Kingdom, latex agglutination test, was used for T. gondii antibody detection. Positive samples had agglutination patterns at dilutions of 1:64 or greater, except for chickens, whose cut off titre was 1:32. A household was classified as T. gondii seropositive if at least one species tested positive. The study revealed that 78 out of 121 sheep (64.46%), 69 out of 128 goats (53.91%), 36 out of 106 pigs (33.96%), 35 out of 109 cats (32.11%) and 46 out of 137 chickens (33.58%) were seropositive for the parasite. Seropositivity was assessed for association with potential risk factors. Age, location, climate, animal production system, rodent control, cat-feed access and cat faecal disposal were found to be significantly associated with seropositivity using the Chi-Squared test or odds ratio confirmed by the Fisher's exact test. The relatively high seroprevalence of T. gondii detected in this study suggests that the infection T. gondii poses a substantial public health risk through the consumption of infected raw or undercooked meat infected with T.gondii cysts as well as contact with cat faeces infected with T. gondii oocysts. / Dissertation (MSc)--University of Pretoria, 2016. / Veterinary Tropical Diseases / MSc / Unrestricted
44

The oral application of the Onderstepoort biological products fowl typhoid vaccine, its safety, efficacy and duration of protection in commercial laying hens

Purchase, Cromwell 12 August 2008 (has links)
This project was undertaken to establish whether the Onderstepoort Biological Products Fowl Typhoid (OBPft) vaccine registered as an injectable vaccine was effective and safe when administered orally to commercial layers. Its efficacy and duration of protection were compared to the intramuscular injectable route. Commercial brown layer hens were used as they were found to be highly susceptible to Salmonella gallinarum infections. In the safety trial birds were euthanased at timed intervals spanning 4-weeks post vaccination. Necropsies were performed and samples were taken and tested. No clinical signs or mortalities could be attributed to the OBPft vaccine. No active shedding of the vaccine strain could be detected. Slight pathological changes were noted with both routes of vaccination; however these changes were transient, returning to normal within the observation period. The injected group showed a better serological response with the serum agglutination test than the orally vaccinated groups. In the duration of protection trial the two routes of vaccination were compared, the birds were challenged at three 8-week intervals post vaccination. All the unvaccinated birds died. The protection offered to the vaccinated groups was good when birds were challenged 8 and 16-weeks after vaccination. However, this dipped steeply by the challenge 24-weeks post vaccination. Statistically (ANOVA, p<0.05) it was found that there was no significant difference between the protection offered by either the oral or injected route of vaccination with the OBPft vaccine. / Dissertation (MSc (Veterinary Science))--University of Pretoria, 2006. / Production Animal Studies / unrestricted
45

Antigenic analyses of Agrobacterium tumefaciens, Agrobacterium radiobacter and normal and tumor tissues of Vinca rosea

Citron, Jean Manch January 1974 (has links)
This document only includes an excerpt of the corresponding thesis or dissertation. To request a digital scan of the full text, please contact the Ruth Lilly Medical Library's Interlibrary Loan Department (rlmlill@iu.edu).
46

A critical study of the factors involved in the rapid method agglutination test for pullorum infection of the domestic fowl

Meriwether, Lodwick Sterritt January 1929 (has links)
M.S.
47

Characterization of the Capsular Polysaccharide of Haemophilus parasuis and its Application in the Diagnosis and Prevention of Glasser's Disease

Hyman, Anne Catherine Michalenka 20 April 2015 (has links)
Haemophilus parasuis is a Gram-negative bacterium responsible for Glasser's Disease in pigs, though little is known regarding its antigenic or virulence factors. Our goals were to characterize the H. parasuis capsular polysaccharide (CP), determine its role in serotype-specificity and virulence, determine if CP is immunogenic, and develop diagnostic and protective products to prevent rampant H. parasuis infection within swine herds. Material from H. parasuis was purified using carbohydrate isolation techniques and compared to CPs from other Pasteurellaceae. Rabbits were immunized with CPs to generate antisera for microscopy, immunoassays, and bactericidal assays. CP antisera were conjugated to latex particles to create an agglutination assay for detection and typing of H. parasuis. CP was conjugated to Cholera Toxin B, and used to immunize mice and piglets before challenge with H. parasuis to determine its protective efficacy against Glasser's Disease. Broth-grown cells expressed CP, which reacted with antisera in microscopy and immunoassays. Broth-grown H. parasuis cells were serum-resistant unless homologous anti-CP serum was present. In contrast, agar-grown cells did not react with antisera in immunoassays, and cells were susceptible to killing by normal swine serum. CP was not expressed on the surface of agar-grown cells unless supplemented with bicarbonate. The addition of bicarbonate also contributed to the variability in CP quantity and upregulation of genes in the CP locus. Sensitized latex particles agglutinated strongest with homologous H. parasuis CPs, cells, and agar-grown cell lysates, but also reacted weakly with higher concentrations of heterologous CPs. The latex beads did not agglutinate with non-H. parasuis swine bacterial pathogens. Mice immunized with the CP-CTB conjugate produced a significantly higher IgG2/Th2 response than unimmunized mice or mice immunized with only CP, and immunized mice had fewer bacteria in their tissues that unimmunized mice. The CP conjugate produced a robust IgG antibody response to CP when used to immunized piglets, but because the control animals also survived H. parasuis challenge, the protective efficacy remains inconclusive. Therefore, the H. parasuis CP is the antigen that confers serotype identity, and can be implemented in methods and help direct future research in disease prevention and serotype tracking in H. parasuis infections. / Ph. D.
48

The effect of fowl typhoid vaccination upon the macroscopic agglutination test for white diarrhea infection

Thorp, Frank January 1927 (has links)
M.S.
49

Emprego de estirpes de leptospiras isoladas no Brasil, na microtécnica de soroaglutinação microscópica aplicada ao diagnóstico da leptospirose em rebanhos bovinos de oito estados brasileiros / Use of strains of leptospires isolated in Brazil, for the microscopic agglutination test applied to the diagnosis of leptospirosis in bovine herds of eight Brazilian states

Sarmento, Anna Maria Casagrande 22 January 2010 (has links)
A leptospirose bovina é uma das principais doenças reprodutivas que interfere diretamente nos índices de produção e produtividade da pecuária brasileira e mundial e por isso necessita de um aprimoramento do diagnóstico laboratorial. O objetivo do presente trabalho foi investigar a conveniência do emprego de estirpes de leptospiras autóctones isoladas no Brasil, na coleção de antígenos da microtécnica de soroaglutinação microscópica (SAM) aplicada a leptospirose. A coleção de antígenos de referência foi constituída pelos sorovares: Australis, Bratislava, Autumnalis, Butembo, Castellonis, Bataviae, Canicola, Whitcombi, Cynopteri, Grippotyphosa, Hebdomadis, Copenhageni, Icterohaemorrhagiae, Javanica, Panama, Pomona, Pyrogenes, Hardjo, Wolffi, Shermani, Tarassovi, Patoc e Sentot. As dez estirpes isoladas no Brasil incluíram os sorovares: Bananal (duas estirpes), Brasiliensis, Canicola (três estirpes), Copenhageni, Guaricura e Pomona (duas estirpes). Foram amostradas por conveniência, 109 propriedades e 9820 bovinos, fêmeas em idade de procriar, distribuídos em 84 municípios, dos Estados de: Goiás, Mato Grosso, Mato Grosso do Sul, Minas Gerais, Paraná, Rio Grande do Sul, Santa Catarina e São Paulo. Dos 9820 animais examinados, 5806 (59,12%) foram reagentes na SAM para qualquer sorovar com a coleção de 23 sorovares de referência. Com a coleção de antígenos de referência e dez estirpes autóctones houve 6400 (65,17%) reagentes, a diferença observada foi significante (p= 0,001). O único Estado em que não houve diferença significante no número de animais reatores para qualquer sorovar foi o de Santa Catarina (p=0,522). Das 109 propriedades trabalhadas, 106 foram consideradas positivas com pelo menos um animal reagente na SAM. Não houve diferença no número de propriedades positivas segundo a coleção de antígenos empregada. Os sorovares mais prováveis identificados com a coleção de antígenos de referência foram Hardjo (43,03 %), Shermani (20 %), Wolffi (9,96%), Grippothyphosa (5,42%) e Pomona (4,28%). Com a coleção ampliada por dez estirpes isoladas no Brasil, os sorovares mais prováveis foram Hardjo (31,00%), Guaricura - M4/84 (22,50%), Shermani (15,43%), Wolffi (4,76%), Grippothyphosa (3,71%) e Autumnalis (3,24%). O sorovar Guaricura, estirpe M4/84, isolada de bovinos e búfalos no Estado de São Paulo, foi o primeiro colocado como sorovar mais provável no Estado de Mato Grosso, diferença significante do valor obtido para o sorovar Hardjo (p= 0,0001). No Mato Grosso do Sul a despeito do valor absoluto ter sido superior para o sorovar Guaricura, a diferença observada com o sorovar Hardjo foi destituída de significado estatístico (p=.0,753). Em São Paulo o Guraricura foi o segundo colocado e em Minas Gerais Goiás ocupou a terceira posição. Esta mesma estirpe foi a mais provável em 27 propriedades das 109 trabalhadas (24,77%). A introdução de estirpes autóctones na coleção de antígenos da SAM propiciou a confirmação do diagnóstico de leptospirose em 594 animais (6,00%) classificados como não reagentes pela coleção de referência (p=0,001) / Bovine leptospirosis is one of the main reproductive diseases which interferes economically on the livestock and thus it is needed the amelioration of the laboratory diagnostic procedures. The aim of this work is to investigate the adequacy to use autochthonous strains of leptospires isolated in Brazil, added into the antigen collection applied for the microscopic agglutination test (MAT). The reference antigen collection was constituted by the following serovars: Australis, Bratislava, Autumnalis, Butembo, Castellonis, Bataviae, Canicola, Whitcombi, Cynopteri, Grippothyphosa, Hebdomadis, Copenhageni, Icterohaemorrhagiae, Javanica, Panama, Pomona, Pyrogenes, Hardjo, Wolffi, Shermani, Tarassovi, Patoc and Sentot. The ten strains isolated in Brazil included the serovars: Bananal (two strains), Brasiliensis, Canicola (three strains), Copenhageni, Guaricura and Pomona (two strains). By means of non-probability sampling, 109 farms and 9,820 bovines, females at reproductive age were chosen from the 84 municipalities of the states of Goiás, Mato Grosso, Mato Grosso do Sul, Minas Gerais, Paraná, Rio Grande do Sul, Santa Catarina e São Paulo . Among the 9,820 examined animals, 5,806 (59.12%) were reactants to the MAT for any serovar using the 23 reference serovars. Using the collection of reference serovars and the ten autochthonous strains there were 6,400 (65.24%) reactants, and the difference found was significant (p=0.001). The only state with non-significant results in the number of reactants for any serovar was the State of Santa Catarina (p=0.522). Of the 109 properties analyzed, 106 were considered positive at least with one reactant animal by MAT. According to the antigens used, there was no significant difference among the properties. The most probable serovars identified by the collection of reference antigens were Hardjo (43.03%), Shermani (20.00%), Wolfi (9.96%), Grippothyphosa (5.42%) and Pomona (4.28%). With the collection amplified with the ten strains isolated in Brazil, the most probable serovars were Hardjo (31.00%), Guaricura M4/84 (22.50%), Shermani (15.43%), Wolffi (4.76%), Grippothyphosa (3.71%) and Autumnalis (3.24%). The serovar Guaricura, strain M4/84, isolated from bovines and buffaloes in the State of São Paulo, was ranked at the first place as the most probable serovar in the State of Mato Grosso and Mato Grosso do Sul, but the differences observed with the serovar Hardjo were significant only in Mato Grosso (p=0,0001). In São Paulo State, the Guaricura serovar was the second most probable and in the states of Minas Gerais and Goiás the third one. This same strain was the most probable in 27 properties among the 109 examined (24.77%). The addition of autochthonous strains into the MAT antigen collection provided the confirmation of the diagnosis of leptospirosis in 594 animals (6.00%) which have been classified as non-reactants by the reference collection
50

Soroprevalência e aspectos epidemiológicos da leptospirose caprina no Município de Uberlândia, MG / Seroprevalence and epidemiology aspects of caprine leptospirosis from uberlândia county, Minas Gerais state, Brazil

Santos, Jandra Pacheco dos 26 March 2007 (has links)
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / The seroprevalence of leptospirosis in the goat flocks created in the Minas Gerais State is little studied. The objectives of this study were (i) to investigate the seroprevalence of leptospirosis in goats of Uberlândia city, MG and to verify predominant serovars; (ii) to identify to the risk factors associates to the infection in the studied properties; (iii) to carry through the isolation and the identification of Leptospira spp. in urine samples of seropositive animals and, (iv) to identify alterations in urinalysis. Were analyzed 230 samples of serum proceeding from 11 properties, using the microscopic agglutination test (MAT). An epidemiologist inquiry was elaborated which gave supplied for the analysis of the risk factors. It was used Stuart s medium base for the isolation of leptospiras. In urinalysis, the samples were submitted to the examinations physical, chemical and evaluation of the urinary sediment. The prevalence of leptospirosis was of 31,30%, with titers varying the 1:100 to 1:800. More found serovars were autumnalis (30,30%), tarassovi (19,20%), pyrogenes (13,13%) and icterohaemorrhagiae (11,11%). The age and the breed had met enter the estatistic significant factors of risk for the infection between the animals. In the properties, the intensive system of production, the use of wage-earning workmanship and the creation of other animal species had been related with the higher frequencies of leptospirosis. It was not possible to isolate leptospiras of the urine samples and had not been found alterations in urinalysis that they suggested infection for the bacterium. The results had shown that the inadequate behaviors of handling in the properties favor the occurrence of one high number of animals displayed to the infection for leptospiras in the goat flocks of Uberlândia. / A soroprevalência da leptospirose nos rebanhos caprinos criados no Estado de Minas Gerais é pouco estudada. Esta pesquisa teve por objetivos (i) investigar a soroprevalência de leptospirose em caprinos do município de Uberlândia, MG e verificar os sorovares predominantes; (ii) identificar os fatores de risco associados à infecção nas propriedades estudadas; (iii) realizar o isolamento e a identificação de Leptospira spp. em amostras de urina dos animais soropositivos e, (iv) identificar alterações na urinálise. Foram analisadas 230 amostras de soro provenientes de 11 propriedades, utilizando o teste de soroaglutinação microscópica (SAM). Foi elaborado um inquérito epidemiológico que forneceu dados para análise dos fatores de risco. Utilizou-se meio de cultura Stuart para o isolamento de leptospiras. Na urinálise, as amostras foram submetidas a exames físico, químico e avaliação do sedimento urinário. A taxa de prevalência da leptospirose foi de 31,30%, com títulos variando de 1:100 a 1:800. Os sorovares mais encontrados foram autumnalis (30,30%), tarassovi (19,20%), pyrogenes (13,13%) e icterohaemorrhagiae (11,11%). A idade e a raça encontraram-se entre os fatores de risco estatisticamente significativos para a infecção nos animais. Nas propriedades, o sistema de produção intensivo, a utilização de mão de obra assalariada e a criação de outras espécies animais foram relacionados com as maiores freqüências da leptospirose. Não foi possível isolar leptospiras das amostras de urina e não foram encontradas alterações na urinálise que sugerissem infecção pela bactéria. Os resultados mostraram que as condutas inadequadas de manejo nas propriedades favorecem a ocorrência de um elevado número de animais expostos à infecção por leptospiras nos rebanhos caprinos de Uberlândia. / Mestre em Ciências Veterinárias

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