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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.
91

Caracterização molecular de isolados de Giardia de amostras de água e esgoto provenientes do Estado de São Paulo / Molecular characterization of Giardia isolates in water and sewage samples from São Paulo State

Lícia Natal Fernandes 11 August 2009 (has links)
Introdução - Giardia é um protozoário que parasita o intestino de quase todas as classes de vertebrados, podendo causar giardíase. Dentre os sete agrupamentos da espécie G. duodenalis, nomeados de A a G, apenas A e B foram encontrados no homem. Por se tratar de um patógeno de veiculação hídrica, a pesquisa de cistos desse microorganismo em água e esgoto é de interesse para a saúde pública. Uma vez que os métodos convencionais utilizados para a detecção desse protozoário em amostras ambientais não permitem diferenciar os isolados de Giardia potencialmente patogênicos para o homem dos demais, o emprego de técnicas que possibilitam a caracterização molecular do parasita em questão se torna necessário, principalmente no Brasil, onde as informações sobre os genótipos de Giardia do ambiente são escassas. Objetivos - Detectar a presença e identificar os genótipos de Giardia sp. em amostras de água e esgoto provenientes do estado de São Paulo, discutindo a importância dos achados para a saúde pública, bem como elaborar uma estratégia que possibilite a realização de tal proposta. Método - Amostras de esgoto bruto (5) e tratado (6), de águas superficiais (11), de poço (3) e de nascente (1) foram coletadas e concentradas pela técnica de membrana filtrante modificada ou por centrifugação. O DNA genômico foi extraído pelo método de fenol/clorofórmio/álcool-isoamílico. A amplificação do fragmento de 890pb do gene gdh, que codifica a produção de glutamato desidrogenase, foi realizada por nested PCR, seguida por clonagem e seqüenciamento de nucleotídeos. Resultados - Onze dentre as vinte e seis amostras analisadas (42,3por cento) foram confirmadas como sendo positivas para a presença de Giardia duodenalis. Os agrupamentos A, genótipo AII, e B foram encontrados. Conclusão - Esses achados indicam que, no estado de São Paulo, isolados de Giardia associados a giardíase humana estão presentes em esgoto tratado e em água superficial e de poço, de modo que o contato com esse tipo de matriz pode representar risco para a saúde pública. Além disso, a estratégia proposta possibilita a caracterização molecular de isolados de Giardia de amostras de água e esgoto. / Introduction - Giardia is a protozoan that parasitizes almost all classes of vertebrates, causing giardiasis. Among the seven assemblages of G. duodenalis, named A to G, only A and B have been found in humans by this moment. As considered a waterborne pathogen, the detection of cysts in water and sewage samples is of interest for public health. Once conventional methods are not able to distinguish Assemblages A and B of G. duodenalis from others, the application of techniques that allow a molecular characterization of Giardia isolates is an important issue, especially in Brazil, where there is scarce information about the genotypes of this parasite in the environment. Objective - To detect and identify Giardia genotypes in water and sewage samples from São Paulo state, discussing the importance of findings for public health, as well as develop a strategy that makes it possible. Method - Raw (5) and treated (6) sewage, surface (11), well (3) and spring (1) water samples were collected and concentrated by modified membrane filtration technique or centrifugation. Genomic DNA was extracted using phenol/chloroform/isoamilic alcohol method. A 890bp fragment of gdh gene, that codes the glutamate dehydrogenase production, was amplified by nested PCR. Cloning and sequencing were subsequently done. Results - 11 out of 26 (42,3 per cent) samples were confirmed to be positive for the presence of G. duodenalis. Assemblages A, genotype AII, and B were found. Conclusions - These findings indicate that, in São Paulo state, Giardia isolates associated to human giardiasis are present in treated sewage and in surface and well water. Thereby, the contact with these matrices can offer risk for public health. Besides, the approach described here allows the molecular characterization of Giardia isolates from water and sewage samples.
92

HPV and p16 in head and neck cancer

Sailan, Ahmad Tarmidi January 2010 (has links)
There is some evidence to suggest that human papilloma virus (HPV) may play a causal role in head and neck carcinoma (HNSCC). The aim of this study was to investigate the prevalence of HPV DNA in HNSCC and to determine whether any correlation exists with p16 or survival. An initial pilot study of sixty formalin-fixed HNSCC was carried out in order to optimise the methodology for the PCR and immunohistochemistry. A further 84 benign lesions, 12 dysplasias and additional 80 HNSCC were also included. In the pilot study the prevalence of all HPV types was 67% of which 18% were high risk-HPV (HR-HPV) and for the combined carcinoma sample it was 59% of which 25% were HR-HPV. The overall HPV prevalence was 51% and 42% for benign lesions and dysplasias with HR-HPV accounting for 14% and 8% respectively. A total of four alpha HPV types were identified and eleven beta HPV types. Multiple HPV types co-existed in the same tissue and in some cases both alpha and beta HPV. The results may suggest that HR-HPV may play a role in a small subset of HNSCC. An association was found between HPV status and gender, age group, survival, nodal metastasis and T3 tumour size and smoking. HPV16 was predominantly present in female patients and was associated with an improved overall survival and recurrence free survival. p16 positivity varied from 76-78% in carcinomas, 51% in benign lesions and 66% in dysplasias. p16 status was not associated with disease recurrence or nodal metastasis. Positive p16 staining and high staining intensity was associated with a poorer overall survival and the male gender, an older age group, anatomic site, and T2 tumour size. Overall HPV status was not correlated with p16 expression but a correlation found between p16 and HPV16 may suggest that p16 could potentially act as a surrogate marker of HPV16. However, the lack of concordance would suggest that in isolation p16 may not be a reliable marker for HR-HPV and should not be relied upon in isolation. Our findings could suggest that HPV16 and p16 status may be independent predictors for prognosis and disease recurrence.
93

Immunoproteomic characterization of Brucella canis to identify proteins candidates as antigens for serodiagnosis / Caracterização imunoproteômica de Brucella canis para a identificação de proteínas candidatas a antígenos para sorodiagnóstico

David Attuy Vey da Silva 17 July 2018 (has links)
Canine brucellosis is a zoonotic disease, caused by Brucella canis, which is the main cause of abortion and infertility in dogs. This study had the objective to investigate a B. canis outbreak in a breeding kennel, to describe a multistep approach to characterize the B. canis isolates obtained, and to identify B. canis proteins specifically reacting with antibodies from naturally infected dogs. The kennel was located in São Paulo, SP, Brazil. At the time of sampling, in 2014, the kennel comprised 17 adult Pug dogs. Blood samples were used both to isolate the bacteria and to detect Brucella spp. DNA by the polymerase chain reaction. Serum samples were used to detect antibodies against B. canis using an immunocromatographic test, the rapid slide agglutination test with or without 2-mercaptoethanol and two ELISA kits. The Brucella isolates were characterized through the classical bacteriological tests, mass spectrometry and whole genome sequencing. The total protein content of Brucella isolates was extracted and separated using one and two-dimension polyacrylamide gel electrophoresis (1D and 2D, respectively), and then tested against sera collected from bacteremic, non-bacteremic and non-B. canis infected dogs using western immunoblotting. The reacting protein spots were identified using matrix-assisted laser desorption/ionization time of flight mass spectrometry (MALDI-TOF MS). Vaginal discharge, abortion, stillbirth, conception failure and general lymphadenopathy were the clinical signs found in the infected dogs. Gram-negative, coccoid rod-shaped bacteria were isolated from 24 blood samples. Antibodies against B. canis were detected in all dogs at least once by the performed serological tests. Mass spectrometry analysis assigned all isolates to the genus Brucella. The phenotypic data clearly identified the isolates as B. canis with only slight differences in phage typing patterns. The 2D separated protein spots were identified by MALDI-TOF MS as 93 different proteins, out of them, 19 were identified in infected dogs (during the bacteremic and non-bacteremic phases of the infection) and were not identified in non-infected dogs. These proteins have the potential to be used as antigens in serological tests in an attempt to improve the diagnosis of the infection, since a reliable diagnosis is an essential measure for the control and prevention of canine brucellosis. The multistep approach using classical microbiological methods, mass spectrometry and whole genome sequencing allowed the characterization of the B. canis with high discriminatory power, which may be useful for outbreak investigations. / A brucelose canina é uma doença zoonótica, causada pela Brucella canis, que é uma das principais causas de abortamentos e infertilidade em cães. O objetivo deste estudo foi investigar um surto de B. canis em um canil, caracterizar os isolados de Brucella obtidos e identificar proteínas de B. canis reagentes especificamente a anticorpos de cães naturalmente infectados. O canil é localizado em São Paulo, SP, Brasil e no momento da amostragem, em 2014, o canil era composto por 17 cães adultos da raça Pug. Amostras de sangue foram utilizadas tanto para isolar as bactérias quanto para detectar o DNA de Brucella spp. pela reação em cadeia pela polimerase. Amostras de soro foram utilizadas para detectar anticorpos contra B. canis nos soros dos cães, utilizando um teste imunocromatográfico, o teste de soroaglutinação rápida em placa com ou sem 2-mercaptoetanol e dois kits de ELISA. Os isolados foram caracterizados pelos métodos bacteriológicos clássicos, espectrometria de massa e pelo sequenciamento do genoma completo. O conteúdo proteico total dos isolados de B. canis foi extraído e as proteínas separadas por eletroforese em gel de poliacrilamida de uma e duas dimensões (1D e 2D, respeectivamente), sendo então testadas frente aos soros dos cães infectados (com ou sem bacteremia) e não infectados, utilizando Western Immunoblotting. Os spots proteicos reagentes foram identificados usando espectrometria de massa por ionização/dessorção a laser assistida por matriz (MALDI-TOF MS). Secreção vaginal, aborto, natimorto, falha na concepção e linfoadenopatia foram os sinais clínicos observados nos cães infectados. Coco-bacilos gram-negativos foram isolados em 24 amostras de sangue. Anticorpos contra B. canis foram observadas em todos os cães, em pelo menos uma amostragem, pelos testes sorológicos empregados. A MS atribuiu todos os isolados ao gênero Brucella. Os dados fenotípicos identificaram claramente B. canis com apenas pequenas diferenças nos padrões de lise por fagos. Os spots de proteínas, separados por 2D, foram identificados por MALDI-TOF MS como 93 diferentes proteínas, dentre elas, 19 foram identificadas em cães infectados (com ou sem bacteremia) e não foram identificadas nos cães não infectados. Tais proteínas são candidatas a serem utilizadas como antígenos para o aprimoramento do sorodiagnóstico, uma vez que a existência de um diagnóstico confiável constitui uma medida essencial para o controle e a prevenção da brucelose canina. A abordagem múltipla utilizada, envolvendo métodos microbiológicos clássicos, espectrometria de massa e sequenciamento completo do genoma bacteriano possibilitou a caracterização dos isolados de B. canis com elevado poder discriminatório, o que pode auxiliar em investigações de surtos.
94

PCR-RFLP no ?xon II do gene da leptina e avalia??o das caracter?sticas f?sicas da carne de caprinos machos inteiros saanen e cruzados saanen X boer / PCR-RFLP in exon II of the leptin gene and evaluation of the physical characteristics of meat from boars Saanen goats and crossed Saanen x Boer

Silva, Rebecca Barbosa 04 March 2016 (has links)
Submitted by Celso Magalhaes (celsomagalhaes@ufrrj.br) on 2017-08-08T14:42:16Z No. of bitstreams: 1 2016 - Rebecca Barbosa Silva.pdf: 755345 bytes, checksum: 51b2e7f47c9cc4e8177521a6ed62a89d (MD5) / Made available in DSpace on 2017-08-08T14:42:16Z (GMT). No. of bitstreams: 1 2016 - Rebecca Barbosa Silva.pdf: 755345 bytes, checksum: 51b2e7f47c9cc4e8177521a6ed62a89d (MD5) Previous issue date: 2016-03-04 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior - CAPES / Molecular markers are important tools in the marker assisted selection programs (MAS). Leptin is expressed hormone mainly in the adipocytes and involved in the regulation of energy metabolism, fat deposition, regulation of glycemia and reproductive physiology and thus has been investigated in association studies quality carcass characteristics and meat in different species. Objective with this work identify the polymorphism in the Leptin gene, changes in qualitative and quantitative characteristics of meat and goat carcass and relate variations of productive features to potential polymorphisms. They were used for genotyping 38 goats intact males, 21 Saanen and 17 crusaders Boer x Saanen. Genotypes for the marker were identified by PCR-RFLP technique based on standardized protocols for SNP305. DNA samples were isolated from leukocyte genomic and amplified through reaction technique Polymerase Chain Reaction (PCR). The generated PCR fragments of 94 base pairs (bp) were digested by Kpn2I enzyme yielding two fragments 75 (bp), 19 (bp) for all individuals analyzed, obtaining allelic frequency of 100% for T. Thus genotype, it was not possible to correlate the results obtained in the evaluation of quality meat and carcass to the results of the molecular study. For the evaluation of carcass quality and meat was used 18 male, 9 Saanen and Saanen x 9 crusaders Boer. t test was used for independent samples of the statistical program BioEstat the 5% significance (P<0.05) for morphometric measurements, live weight, live weight after fasting, hot carcass weight, cold carcass weight, cooling breaks, carcass yield, loss of cooling, thick fat cover, color, pH, water holding capacity and tenderness of the meat, weight and yield cuts (shoulder, hand saw, rib set, ham and loin) and compactness index of carcass. The grouping of the Crusaders animals showed significant differences (P<0.05) for wide shank and shear force. For Saanen animals, there was a significant difference (P<0.05) for the external length of the housing. Although Crossed have shown higher shear strength values (P<0.05), the two groups had average below 5.4 kg-f cm-?, featuring soft meats in goats (2.20 and 1, 57 kg f cm-2 for Crossed and Saanen, respectively). The results showed that the use of both the Crusaders animals, as the Saanen animals are a viable option for dairy farmers who wish to diversify their activities, taking advantage of the disposal of male goats for meat production / Os marcadores moleculares s?o importantes ferramentas nos programas de sele??o assistida por marcadores (MAS). A Leptina ? um horm?nio expresso principalmente nos adip?citos e est? envolvido na regula??o do metabolismo energ?tico, deposi??o de gordura, regula??o da glicemia e fisiologia reprodutiva e por isso tem sido investigado em estudos de associa??o a caracter?sticas de qualidade de carca?a e carne em diferentes esp?cies. Objetiva-se com este trabalho identificar o polimorfismo no gene da Leptina, as varia??es nas caracter?sticas qualitativas e quantitativas da carne e da carca?a de caprinos e relacionar as varia??es das caracter?sticas produtivas a poss?veis polimorfismos. Foram utilizados para a genotipagem 38 cabritos machos inteiros, sendo 21 Saanen e 17 Cruzados Saanen x Boer. Os gen?tipos para o marcador foram identificados pela t?cnica de PCR-RFLP com base nos protocolos padronizados para o SNP305. Foram isoladas amostras de DNA gen?mico a partir de leuc?citos e amplificados por interm?dio da t?cnica de Rea??o em Cadeia de Polimerase (PCR). A PCR gerou fragmentos de 94 pares de bases (pb) que foram digeridos pela enzima Kpn2I, originando dois fragmentos de 75 (pb) e 19 (pb) para todos os indiv?duos analisados, obtendo frequ?ncia al?lica de 100% para o gen?tipo T. Dessa forma, n?o foi poss?vel correlacionar os resultados obtidos na avalia??o de qualidade de carne e carca?a aos resultados obtidos no estudo molecular. Para a avalia??o de qualidade de carca?a e carne foram utilizados 18 machos inteiros, 9 Saanen e 9 Cruzados Saanen x Boer. Foi aplicado o teste t para amostras independentes do programa estat?stico BioEstat a 5% de signific?ncia (P<0,05) para as medidas morfom?tricas, peso vivo, peso vivo ap?s jejum, peso de carca?a quente, peso de carca?a fria, quebra de resfriamento, rendimentos de carca?a, perda por resfriamento, espessura de gordura de cobertura, cor, pH, capacidade de reten??o de ?gua e maciez da carne, peso e rendimento de cortes (paleta, serrote, carr?, pernil e lombo) e ?ndice de compacidade da carca?a. O grupamento dos animais Cruzados apresentou diferen?as significativas (P<0,05) para largura de pernil e for?a de cisalhamento. Para os animais Saanen, houve diferen?a significativa (P<0,05) para o comprimento externo da carca?a. Embora os Cruzados tenham apresentado maiores valores de for?a de cisalhamento (P<0,05), os dois grupos obtiveram m?dias abaixo de 5,4 kg-f cm-2, o que caracteriza carnes macias em caprinos (2,20 e 1,57 kg-f cm-2 para Cruzados e Saanen, respectivamente). Os resultados mostraram que a utiliza??o tanto dos animais Cruzados, quanto dos animais Saanen s?o uma op??o vi?vel aos produtores de leite que desejam diversificar as atividades, aproveitando os cabritos machos de descarte para a produ??o de carne
95

Multilocus Virulence Typing of Clinical and Environmental <em>Vibrio vulnificus</em> Isolates

Gordon, Katrina V 18 July 2008 (has links)
The bacterium Vibrio vulnificus is an autochthonous inhabitant of estuarine waters and also found in shellfish such as oysters. It is a human pathogen of importance in the seafood industry, and can also infect recreational water users. Currently, recognized methods of detection rely upon isolation of pure cultures which requires at least 24 hours. To reduce the time needed for identification of the pathogen and simultaneously ascertain the virulence potential of the strains present, real-time PCR assays and sample processing procedures were developed (Chapter 1). These assays discriminate between type A (environmental, generally lower virulence) and type B (clinical, higher virulence) isolates. The genetic relationships between environmental V. vulnificus strains isolated from permitted and prohibited shellfish harvesting areas was determined using BOX-PCR genomic fingerprinting coupled with sequence analysis of three proposed virulence markers: (1) the virulence correlated gene (vcg), (2) 16S rRNA type and (3) presence/absence of the vulnibactin gene (viuB) (Chapter 2). The real-time PCR assays were able to detect the presence of seeded V. vulnificus in environmental water at a concentration of 160 cells 100·ml-1. In seeded oyster homogenates, the assays were able to detect a minimum of 10³ cells and 10² cells per reaction of type A and type B respectively. The phylogenetic analysis separated the majority of type A/ vcgE strains isolated from permitted shellfish harvesting areas from those isolated from prohibited harvesting areas. The genomic (BOX-PCR) fingerprints of type A and type AB isolates were more similar to one another than to type B isolates. Only one type A/ vcgE isolate contained the viuB gene; however, eight type B/ vcgC isolates had that gene. No obvious grouping was discerned between type B/ vcgC isolates from permitted versus prohibited shellfish harvesting areas or between those possessing the viuB gene versus those lacking viuB. These data provide insight into the ecology and correlation between population biology and general water quality, as gauged by the classification of the shellfish growing area waters. The 16S typing assays can be used for routine rapid typing to aid in risk assessment and reduce infection frequency through consumption of contaminated seafood.
96

Etude du polymorphisme associé aux répétitions en tandem pour le typage de bactéries pathogènes : Pseudomonas aeruginosa et Staphylococcus aureus

Onteniente, Lucie 13 February 2004 (has links) (PDF)
Les répétitions en tandem sont constituées de successions de motifs d'ADN. Ces structures présentes dans tous les organismes, procaryotes comme eucaryotes, ont des applications dans de nombreux domaines. Depuis quelques années seulement, les répétitions en tandem sont étudiées chez les bactéries. Le polymorphisme associé à ces séquences peut être utilisé pour le génotypage de bactéries pathogènes, permettant une identification précise au niveau de la souche. Le polymorphisme des séquences répétées est de deux types : polymorphisme de longueur et mutations internes aux motifs. Les génomes des deux bactéries pathogènes responsables d'infections nosocomiales, Staphylococcus aureus et Pseudomonas aeruginosa, ont été étudiés dans le but d'identifier des séquences répétées polymorphes. Un ensemble de marqueurs polymorphes a été validé expérimentalement pour ces deux espèces permettant un typage dit MLVA (pour « Multiple Locus VNTR Analysis »). Le travail plus classique de typage par la taille de la répétition a été complété par un travail de séquençage de certains allèles. Les résultats obtenus montrent comment le typage « MLVA » complété si nécessaire par le séquençage d'allèles, pourraient constituer de nouvelles méthodes peu coûteuses participant au contrôle des infections bactériennes.
97

The genetic composition and diversity of Francisella tularensis

Larsson, Pär January 2007 (has links)
<p><i>Francisella tularensis</i> is the causative agent of the debilitating, sometimes fatal zoonotic disease tularemia. To date, little information has been available on the genetic makeup of this pathogen, its evolution, and the genetic differences which characterize subspecific lineages. These are the main areas addressed in this thesis.</p><p>The work indicated a high degree of genetic conservation of <i>F. tularensis</i>, both on the sequence level as determined by sequencing and on the compositional level, determined by array-based comparative genomic hybridizations (aCGH). One striking finding was that subsp. mediasiatica was most similar to subsp. tularensis, despite their natural confinement to Central Asia and North America, respectively. All genetic Regions of Difference RD found by aCGH distinguishing lineages were had resulted from repeat-mediated excision of DNA. This was used to identify additional RDs. Such data along with a multiple locus sequence analysis suggested an evolutionary scenario for F. tularensis. </p><p>Based on genomic information, a novel typing scheme for <i>F. tularensis</i> was furthermore devised and evaluated. This method provided increased robustness compared to previously used methods for <i>F. tularensis</i> typing, while retaining a capacity for high resolution.</p><p>Finally, the genomic sequence of the highly virulent <i>F. tularensis</i> strain SCHU S4 was determined and analysed. Evidenced by numerous pseudogenes and disrupted metabolic pathways, the bacterium appears to be undergoing a genome reduction process whereby a large proportion of the genetic capacity gradually is lost. It is likely that <i>F. tularensis</i> has irreversibly has evolved into an obligate host-dependent bacterium, incapable of a free-living existence. Unexpectedly, the bacterium was found to be devoid of common virulence mechanisms such as classic toxins, or type III and IV secretion systems. Instead, the virulence of this bacterium is probably largely the result of specific and unusual mechanisms. </p>
98

Study of Population Diversity of Toxoplasma gondii

Majumdar, Debashree 01 December 2010 (has links)
Toxoplasma gondii, the causal agent of toxoplasmosis, is an important water and food borne protozoan parasite. T. gondii was previously shown to have a distinct clonal population structure composed of Type I, II and III lineages in North America and Europe. But more recent studies demonstrated high diversity in South America. In the present project we have conducted an intensive study of the population diversity of T. gondii and surveyed the extent of genetic variation among natural T. gondii isolates on a global scale in order to better understand the population dynamics and pathogenesis of this parasite. To this end, 948 T. gondii isolates have been collected from a broad range of animal hosts and different sites worldwide. Our initial multilocus PCR-RFLP genotyping analysis revealed high diversity (~140 distinct genotypes) with abundant unique genotypes in South America and a strong clonal population structure in North America, Europe, Asia and Africa. It also showed that the Type II is the most common lineage worldwide, followed by the type III strain. The Type I strain, though widely distributed, has been infrequently isolated. Several new clonal genotypes have been identified from South America. The newly identified 140 RFLP genotypes have been further analyzed by multilocus microsatellites and intron sequencing methods. The composite data set identified 11 different haplotypes, providing a framework for future study of molecular epidemiology and population genetics of T. gondii . Multilocus DNA sequencing of markers from each of the 14 chromosomes covering the entire genome has also been completed to help reveal more information about genome evolution and the origin of T. gondii . Taken together, this comprehensive epidemiological and population genetic study has revealed significant details on the diversity and extent of sexual recombination, which provides the basis for future studies to understand transmission patterns, population dynamics and origin of this successful apicomplexan parasite Toxoplasma gondii.
99

Inter and Intra-Assemblage Characterizations of Giardia intestinalis: from clinic to genome

Ankarklev, Johan January 2012 (has links)
The protozoan parasite Giardia intestinalis (syn. G. lamblia, G. duodenalis) is one of the most common causes of diarrheal disease throughout the world, where an estimated 500 million people are infected annually. Despite efforts in trying to elucidate factors associated with virulence in G. intestinalis little is currently known. The disease outcome is highly variable in Giardia infected individuals, ranging from asymptomatic carriers to severe disease. The reasons behind the differences in disease outcome are vaguely understood and studies trying to link infectivity to different Giardia assemblages or sub-assemblages have rendered conflicting results. Prior to this study, little was known about the prevalence and genetic diversity of different G. intestinalis assemblages across the world. In this thesis, molecular characterization of clinical G. intestinalis samples from Eastern Africa and Central America, has been performed, enabling a better understanding of the prevalence of different Giardia genotypes in endemic areas (Papers I and II). A correlation between Giardia colonization and the presence of Helicobacter pylori in the human host was established. We found that the currently available genotyping tools provide low resolution when used to characterize assemblage A Giardia. Also, genotyping of assemblage B isolates at these loci is troublesome due to the polymorphic substitutions frequently found in the sequencing chromatograms. This ambiguity was investigated by using micromanipulation to isolate single assemblage B Giardia cells (Paper III). Both cultured trophozoites and cysts from giardiasis patients were analyzed. The data showed that allelic sequence heterozygosity (ASH) does occur at the single cell level, but also that multiple sub-assemblage infections appear to be common in human giardiasis patients. Furthermore, genome-wide sequencing followed by comparative genomics was performed in order to better characterize differences between and within different Giardia assemblages. The genome of a non-human infecting, assemblage E isolate (Paper IV) was sequenced.  The genomes of two freshly isolated human infecting assemblage AII isolates were also sequenced (Paper V). Subsequent, comparative analyses were performed and included the genomes of two human infecting isolates, WB (AI) and GS/M (B). Several important differences were found between assemblages A, B and E, but also within assemblage A; including unique gene repertoires for each isolate, observed differences in the variable gene families and an overall difference in ASH between the different isolates. Also, a new multi-locus genotyping (MLG) strategy for genotyping of assemblage A Giardia has been established and evaluated on clinical samples from human giardiasis patients.
100

Reconstruction of major male and female lineages of the Strand Muslim community

Tasneem Geduld January 2010 (has links)
<p>Initially, a pilot study was carried out in order to reconstruct the major paternal and maternal lineages of the Muslim population living in the Cape metropolitan area. The Study has shown the ability of molecular genetic tools to give insight into the origins and history of local communities. The study was also used as a point of reference for the Strand Muslim Community project. Genetic variations of the Y-chromosome and mitochondrial DNA for the pilot study were analyzed using the RFLP technique. The SNaPshot mini-sequencing technique was used to genotype single nucleotide polymorphisms (SNP) on the Y-chromosome and mitochondrial DNA in 115 males from the Strand Muslim community.</p>

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