The genus Populus is ideally suited to investigate questions related to the interplay between an individual’s environmental history and its capacity to respond to external stimuli. In order to dissect the influence of individual history on subsequent plant responses, transcriptome level changes due to water deficit were assessed in clonal populations of Populus hybrids. Results indicate variation in the drought transcriptomes of genetically identical clones originating from different locations can be shaped by the individual history of the clone. Additionally, yearly variations in drought transcriptome patterns showed specific trends associated with a clonal population that were not related to an unknown influence at a location, nor with the biological source of cuttings. Despite these sources of transcriptome variation, a common shared response was identified across all populations. The findings hint at the influence of the environment and epigenetic factors in the dynamic regulation of transcriptome level responses in clonal individuals.

The genus Populus is ideally suited to investigate questions related to the interplay between an individual’s environmental history and its capacity to respond to external stimuli. In order to dissect the influence of individual history on subsequent plant responses, transcriptome level changes due to water deficit were assessed in clonal populations of Populus hybrids. Results indicate variation in the drought transcriptomes of genetically identical clones originating from different locations can be shaped by the individual history of the clone. Additionally, yearly variations in drought transcriptome patterns showed specific trends associated with a clonal population that were not related to an unknown influence at a location, nor with the biological source of cuttings. Despite these sources of transcriptome variation, a common shared response was identified across all populations. The findings hint at the influence of the environment and epigenetic factors in the dynamic regulation of transcriptome level responses in clonal individuals.

This study focused on an invasive riparian reed grass, Arundo donax L., a clonal plant of the family Poaceae that is widely distributed in North America. Water availability, including water taken up from the roots locally or transported from the neighboring ramets, may affect the performance of A. donax in riparian zones. The first objective was to find out how moisture gradients affected the performance of A. donax in riparian zones. I measured leaf photosynthetic rate, leaf δ13C ratio, and plant growth-related parameters across two summer growing seasons at four transects perpendicular to the water course on the Rio Grande in South Texas. The second objective was to find out whether physiological integration existed in A. donax and how resource sharing, if any, affected plant growth. A rhizome severing experiment was conducted on five paired plots to compare growth-related parameters between plots with rhizomes severed and intact at 3, 7, and 11 weeks after treatment. Heavy water (δ 2H ~1800‰) was applied on three 1-m2 area over 3 successive days and rhizome samples were collected beyond the watering zone after 5, 24, and 48 hours of last watering. At short-term scales, A. donax performance was adversely affected by both drought and inundated conditions; over longer time scales, plant performance decreased as water availability declined in general, but biomass and stem density were similar across moisture gradients. I also found evidence of physiological integration in A. donax. Water was transported through interconnected rhizomes at least 3.5 m; transport distances averaged 1.67 m. Rhizome severing stimulated higher ramet production initially but over longer periods produced shorter thinner stems with lower flood tolerance. However, after 11 weeks of re-growth, plot-level biomass was similar between plots with severed and intact rhizomes. These results suggest that performance of A. donax is affected by water availability in riparian zones; however, clonal plant plasticity, water use efficiency, and clonal integration ameliorate impacts of water stress on the performance of A. donax. Such traits enhance its resource use, which could potentially increase competitive ability rate of establishment, and extent of this invasive species in heterogeneous riparian environments.

Antigens play a critical role in the development of chronic lymphocytic leukemia (CLL) by binding to and stimulating leukemic precursor cells at some point during CLL ontogeny. Nevertheless, much remains unknown and further studies are necessary before an accurate model of antigen-drive can be ascertained. In this context, intraclonal diversification (ID) analysis of immunoglobulin (IG) genes could shed light on whether antigen involvement is restricted to the malignant transformation phase or if the triggering antigen(s) continuously stimulates the CLL clone. Hence, in Paper I we conducted a large-scale analysis of 71 CLL cases and revealed that 28/71 cases carried intraclonally diversified IGHV-IGHD-IGHJ genes. Although most cases showed no or low levels of ID, intense ID was evident within all subset #4 (IGHV4-34/IGKV2-30) cases. Subsequent analysis, in Paper II, of the clonotypic light chains revealed that the outstanding exception again related to subset #4. In such cases, the expressed IGKV2-30 gene was affected by targeted ID, analogous to their partner IGHV4-34 gene. Whilst these results convincingly argued for the role of antigen(s) in the development and evolution of CLL subset #4, this analysis was limited to depicting what was occurring at a single time-point and could not provide insight into the temporal dynamics of the CLL clones. Thus, in Paper III we conducted a longitudinal study of 8 subset #4 cases which enabled us to establish a hierarchical pattern of subclonal evolution. The observed ‘stepwise’ accumulation of mutations strongly supports a role for antigen selection in the pathogenesis of CLL subset #4. In Paper IV we reported a subset of IgG-switched CLL patients with coexisting trisomies of 12 and 19, and propose that the emergence of trisomy 18 in such cases represents a clonal evolution event suggestive of selection due to a clonal advantage. Paper V focused on the IGHV3-21 gene, an adverse prognostic factor in CLL. Since ~60% of IGHV3-21-expressing cases carry stereotyped B cell receptors, recognition of a common antigenic epitope, perhaps of pathogenic significance, is envisaged. Therefore, we investigated IGHV3-21 gene frequency within a Swedish population-based cohort and assessed the impact of stereotypy on clinical outcome. Taken collectively, this thesis provides molecular and genetic evidence for the role of antigen in CLL pathogenesis by convincingly demonstrating that clonal evolution, at least for certain subsets of CLL, is functionally driven rather than a consequence of clonal expansion promoted by nonspecific stimuli.

Thesis (PhD) - Swinburne University of Technology, 2008. / A dissertation presented for fulfillment of the requirements for the degree of Doctor of Philosophy, Swinburne University of Technology - 2008. Typescript. Bibliography: p. 349-377.

Made available in DSpace on 2014-06-11T19:23:30Z (GMT). No. of bitstreams: 0 Previous issue date: 2010-08-27Bitstream added on 2014-06-13T19:50:21Z : No. of bitstreams: 1 rosa_ja_me_botfca.pdf: 2648056 bytes, checksum: 7c4b03d6eb60835ce1218269832104b1 (MD5) / O trabalho foi composto por dois experimentos, um no jardim clonal, testando a eficiência da aplicação de concentrações de silício na resistência ao oídio, e o outro com a produção de mudas, testando o efeito das concentrações de silício na transpiração. Ambos foram conduzidos na Faculdade de Ciências Agronômicas (FCA) da UNESP, no município de Botucatu - SP. O primeiro experimento foi um fatorial 2 x 5 (2 clones e 5 concentrações de silício), totalizando 10 tratamentos. O segundo experimento foi um fatorial 2 x 2 (2 clones e 2 concentrações de silício), totalizando 4 tratamentos. Os clones utilizados são híbridos de Eucalyptus grandis x E. urophylla. As avaliações feitas nas cepas do 1º experimento foram: número de brotações, grau de infecção e severidade do patógeno, sobrevivência e teor de macro e micronutrientes. No 2º experimento as avaliações nas mudas constaram de: teores de macro e micronutrientes, altura, diâmetro, massas seca de folha, caule e raiz, e transpiração. No experimento 1 os resultados mostraram que o número de brotos por cepa não foi influenciado pela aplicação do silício. A incidência da doença durante o período em que a temperatura esteve mais baixa não foi influenciada pelas aplicações de silício, tendo mostrado resultados positivos quando houve aumento da temperatura. A sobrevivência das cepas foi maior quando aplicado o silício independentemente da concentração. Houve um efeito negativo da aplicação de silício sobre a severidade da doença em ambos os clones. Para a maioria dos macro e micronutrientes os teores não tiveram diferença entre clone e concentrações de silício aplicadas, exceto o N e K que apresentaram maiores teores no clone 1, e P e Ca que tiveram menores teores quanto maior a concentração de silício aplicada. Os resultados do experimento 2 mostraram que os teores de macronutrientes foram... / This study is consisting of 2 experiments the first was made in the clonal garden testing the efficiency of application of silicon concentrations in the resistance powdery mildew and the second, with seedling production testing the effects of silicon concentrations over transpiration. Both of them were conduced at Faculdade de Ciências Agronômicas (FCA) - UNESP located at Botucatu- SP. The first experiment was a factorial 2 x 5 (2 clones and 5 silicon concentrations), adding 10 treatments. The second experiment was a factorial 2 x 2 (2 clones and 2 silicon concentrations), adding 4 treatments. The clones which have been used at the experiment are hybrids of Eucalyptus grandis x Eucalyptus urophylla. The assessments that have been done on the strains of the first experiment are: number of buds, infection grade and seriousness of the disease agent, survival and the concentration of macro and micronutrients. On the second experiment, the assessments that have been done on the seedling are: concentration of macro and micronutrients, height, diameter, dry weight of leaves, stalk and root, and transpiration. On the first experiment, the results showed that the number of buds for strain was not affected by the silicon application. The disease occurrence in a lower temperature period was not affected by the silicon applications, and it showed positive results when the temperature got higher. The strains survival was higher when silicon was applied, being the concentrations not influential. There was a negative effect from silicon application over the disease seriousness in both of the clones. The most of macro and micronutrients concentration were not different between clone and silicon concentrations treatments (except for N and K that were higher at clone 1 and P and Ca that were lower as higher was the silicon concentration applied). On experiment 2, the results showed that the macronutrients... (Complete abstract click electronic access below)

Submitted by Rodrigo Martins Cruz (rodrigo.cruz@ufvjm.edu.br) on 2015-02-27T13:30:32Z No. of bitstreams: 5 24.pdf: 288332 bytes, checksum: 520195a14408865261a68ead5a355da8 (MD5) license_url: 49 bytes, checksum: fd26723f8d7edacdb29e3f03465c3b03 (MD5) license_text: 20626 bytes, checksum: 7851d446050a985bd0603b7c4cee472d (MD5) license_rdf: 19710 bytes, checksum: aa65da15f424ff71c620a992a187295c (MD5) license.txt: 2110 bytes, checksum: b4c884761e4c6c296ab2179d378436d4 (MD5) / Approved for entry into archive by Rodrigo Martins Cruz (rodrigo.cruz@ufvjm.edu.br) on 2015-02-27T16:56:16Z (GMT) No. of bitstreams: 5 24.pdf: 288332 bytes, checksum: 520195a14408865261a68ead5a355da8 (MD5) license_url: 49 bytes, checksum: fd26723f8d7edacdb29e3f03465c3b03 (MD5) license_text: 20626 bytes, checksum: 7851d446050a985bd0603b7c4cee472d (MD5) license_rdf: 19710 bytes, checksum: aa65da15f424ff71c620a992a187295c (MD5) license.txt: 2110 bytes, checksum: b4c884761e4c6c296ab2179d378436d4 (MD5) / Made available in DSpace on 2015-02-27T16:56:16Z (GMT). No. of bitstreams: 5 24.pdf: 288332 bytes, checksum: 520195a14408865261a68ead5a355da8 (MD5) license_url: 49 bytes, checksum: fd26723f8d7edacdb29e3f03465c3b03 (MD5) license_text: 20626 bytes, checksum: 7851d446050a985bd0603b7c4cee472d (MD5) license_rdf: 19710 bytes, checksum: aa65da15f424ff71c620a992a187295c (MD5) license.txt: 2110 bytes, checksum: b4c884761e4c6c296ab2179d378436d4 (MD5) Previous issue date: 2010 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior (Capes) / O sucesso da propaga??o vegetativa depende do estado nutricional da planta-matriz. Entretanto, padr?es ideais das concentra??es dos nutrientes n?o est?o ainda bem estabelecidos para a miniestaquia. Assim, o objetivo deste trabalho foi avaliar a influ?ncia da aduba??o NPK na produ??o de miniestacas de eucalipto em solu??o nutritiva. O trabalho foi realizado de novembro de 2008 a janeiro de 2009, em casa de vegeta??o. Foi utilizado delineamento inteiramente casualizado em esquema fatorial fracionado (4x4x4)?, perfazendo 32 tratamentos com tr?s repeti??es. Os tratamentos se constitu?ram de quatro doses dos nutrientes de N (50; 100; 200 e 400 mg L-1) na forma de ur?ia, P (7,5; 15; 30 e 60 mg L-1) na forma de ?cido fosf?rico e K (50; 100; 200 e 400 mg L-1) na forma de cloreto de pot?ssio em solu??o nutritiva. Houve apenas efeito significativo para as doses de N isoladamente. Observou-se efeito linear decrescente com o aumento das doses de N para as vari?veis como n?mero de miniestacas, massa seca das miniestacas, massa seca da raiz e parte a?rea da minicepa de eucalipto. O n?mero de miniestacas e os teores de nutrientes foliares das miniestacas se apresentaram adequados ? literatura existente. A distribui??o percentual da massa seca e dos nutrientes variou em fun??o do aumento das doses de N. O maior ac?mulo percentual de nutrientes e de massa seca ocorreu na parte a?rea das minicepas e nas miniestacas. A dose recomendada para o material gen?tico em estudo foi de 50, 7,5 e 50 mg L-1 para NPK, com produtividade de 12 miniestacas por minicepas num per?odo de 30 dias de coleta, com ac?mulo de nutrientes na miniestaca de 6,0 cm de eucalipto de: 86% do N, 56% do P, 42% do K, 42% do Ca, 36% do Mg, 84% do S, 26% do B, 04% do Cu, 15% do Fe, 23% do Mn e 12% do Zn. / Disserta??o (Mestrado) ? Programa de P?s-Gradua??o em Produ??o Vegetal, Universidade Federal dos Vales do Jequitinhonha e Mucuri, 2010. / ABSTRACT The success of vegetative spread depends on the nutritional state of the matrix plant. However, ideal standards of nutrients concentration are not well established for the minicutting yet. So, the objective of this work was to evaluate the influence of NPK fertilizer in the production of minicuttings in a simple hybrid of Eucalyptus urophylla in?nutrient solution. The experiment was realized from November, 2008 to January, 2009 in vegetation ambient. The experimental design was a completely randomized in fractional factorial scheme (4x4x4)1/2 totaling 32 treatments with three replicates. The treatments consisted by four nutrient doses of N (50, 100, 200 and 400 mg L-1) in the urea form, P (7.5, 15, 30 and 60 mg L-1) in the phosphoric acid form and K (50, 100, 200 and 400 mg L-1) in the potassium chloride form, in the nutrient solution. There was a significant effect only for the isolated N doses for the minicuttings. It was observed that the effect with the number and dry mass of minicuttings and dry mass of root and shoots of ministumps of eucalypt decreased linearly with increasing doses of N. The number of minicuttings and the content of the leaf nutrients in minicuttings were appropriate according to the literature. The percentage distribution of dry mass and nutrients varied in function of the N doses increase. The highest percentage accumulation of nutrients and of dry mass occurred in ministumps and miniccutings shoots, except for Cu and Fe. The recommended dose to the genetic material was respectively about 50, 7,5 e 50 mg L-1 for NPK, with productivity of 12 miniccutings per ministumps in a period of 30 days of collecting and with nutrient accumulation in the ministumps about 6,0cm of eucalypt in the following values: 86% of N, 56% of P, 42% of K, 42 of Ca, 36% of Mg, 84% of S, 26% of B, 04% of Cu, 15% of Fe, 23% of Mn, and 12% of Zn.

Submitted by Marco Antônio de Ramos Chagas (mchagas@ufv.br) on 2017-06-27T17:20:35Z No. of bitstreams: 1 texto completo.pdf: 458969 bytes, checksum: 9dd569a29cef4088df1e179931a02750 (MD5) / Made available in DSpace on 2017-06-27T17:20:35Z (GMT). No. of bitstreams: 1 texto completo.pdf: 458969 bytes, checksum: 9dd569a29cef4088df1e179931a02750 (MD5) Previous issue date: 2001-03-22 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / O presente estudo objetivou avaliar a propagação clonal de quatro clones de Eucalyptus grandis pelo uso das técnicas de microestaquia e miniestaquia, analisando-se: a) sobrevivência, vigor e capacidade produtiva das microcepas e minicepas em coletas sucessivas de microestacas e miniestacas; b) sobrevivência, enraizamento e vigor das microestacas e miniestacas; e c) efeito da aplicação do regulador de crescimento AIB (0, 1000, 2000 e 4000 mg l -1 ) na sobrevivência, no enraizamento e no vigor das microestacas e miniestacas. O jardim microclonal foi constituído de microcepas oriundas de mudas rejuvenescidas por micropropagação, mediante subcultivos in vitro, e, no jardim miniclonal, foram utilizadas minicepas obtidas pelo enraizamento de miniestacas oriundas de brotações de plantas propagadas pelo método da estaquia convencional. No enraizamento das microestacas e miniestacas foi utilizada a casa de vegetação, com tempo de permanência variando entre 21 e 28 dias, conforme os tratamentos, com aclimatação de oito dias em casa de sombra e avaliação final das mudas realizada aos 50 dias de idade. De forma geral, não se observou efeito significativo de rejuvenescimento in vitro na sobrevivência, na produção e no vigor das microcepas e minicepas, visto que as duas técnicas apresentaram resultados semelhantes. Para a sobrevivência na saída da casa de vegetação, enraizamento na saída da casa de sombra e sobrevivência das mudas aos 50 dias, foram observados resultados superiores na microestaquia em relação à miniestaquia, sendo essa diferença mais pronunciada em clones com maior dificuldade de enraizamento, indicando, nesses casos, possível efeito de rejuvenescimento dos clones com o uso da microestaquia. As mudas oriundas da microestaquia apresentaram altura e diâmetro do coleto aos 50 dias e peso de matéria seca de raiz aos 28 dias iguais ou superiores aos da miniestaquia, reforçando a suposição de maior grau de juvenilidade das microestacas em detrimento das miniestacas. O tempo de permanência de 21 dias em casa de vegetação mostrou-se suficiente para enraizamento das microestacas e miniestacas, possibilitando a redução de tempo para obtenção de mudas. Com relação à aplicação de AIB, na miniestaquia se observou aumento nos índices de enraizamento e de sobrevivência das miniestacas, nas dosagens de 1000 e 2000 mg l -1 , na maioria dos clones. Na microestaquia, em geral, não se observou efeito do AIB no enraizamento e na sobrevivência das microestacas. Conclui-se, portanto, que clones com maior dificuldade no enraizamento apresentam maior resposta ao rejuvenescimento in vitro pelo uso da microestaquia, resultando em aumento nos índices de enraizamento. / The objective of this study was to evaluate the clonal propagation of four clones of Eucalyptus grandis through the minicuttings and microcuttings techniques, considering: a) survival, vigor and productive capacity of the ministumps and microstumps in successive collections of minicuttings and microcuttings; b) survival, rooting and vigor of the minicuttings and microcuttings; c) the effect of the AIB growth regulator application (0, 1000, 2000, and 4000 mg l -1 ) in survival, rootting, and vigor of the minicuttings and microcuttings. The microclonal garden was composed by microstumps derived from seedling rejuvenated through micropropagation, by means of in vitro subcultivation, and in the miniclonal garden, ministumps obtained by minicuttings derived from rooting sprouting of plants propagated through the conventional cuttings technique were used. In the microcuttings and minicuttings rooting the greenhouse was used, with a permanence time varying from 21 to 28 days, according to the treatments, with an eight day acclimatizing in shadow house and the final seedling evaluation done at 50 days of age. In a general way, a significant in vitro rejuvenation effect in the survival, production and microstumps and ministumps vigor was not observed since both techniques showed similar results. For the survival in the greenhouse exit, rooting in the shadow house exit and survival of the seedlings at 50 days, superior results in the microcuttings techniques in relation to the minicuttings techniques were observed, being this difference more pronounced in clones with greater rooting difficulties, indicating in these cases, a possible rejuvenation of the clones with the microcuttings technique use. The seedlings derived from the microcuttings technique showed high and collect diameter at 50 days and root dry matter weight at 28 days equal or superior to the ones of minicuttings techniques, reinforcing the supposition of the microcuttings greater juvenility degree in prejudice of the minicuttings. The 21 days permanence time in the greenhouse showed to be enough for the microcuttings and minicuttings rooting, making possible the reduction of time for the seedling obtainment. In relation to the AIB application, in the minicuttings technique, an increase in the minicuttings rooting and survival index, in the 1000 and 2000 mg l -1 dosing, in most clones, was observed. In the microcuttings technique, in general, an AIB effect on the microcuttings rooting and survival was not observed. Thus, it was concluded that clones with greater rooting difficulties show greater response to the in vitro rejuvenation by the microcuttings technique use, resulting in an increase in the rooting index. / Dissertação importada do Alexandria

Submitted by Maria Anália Conceição (marianaliaconceicao@gmail.com) on 2016-07-06T18:37:16Z No. of bitstreams: 1 Publico-03.pdf: 680420 bytes, checksum: 28c206d0e333eb6ac5cb4cd4efa99f59 (MD5) / Approved for entry into archive by Maria Anália Conceição (marianaliaconceicao@gmail.com) on 2016-07-06T18:41:05Z (GMT) No. of bitstreams: 1 Publico-03.pdf: 680420 bytes, checksum: 28c206d0e333eb6ac5cb4cd4efa99f59 (MD5) / Made available in DSpace on 2016-07-06T18:41:05Z (GMT). No. of bitstreams: 1 Publico-03.pdf: 680420 bytes, checksum: 28c206d0e333eb6ac5cb4cd4efa99f59 (MD5) Previous issue date: 2009 / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / O Vírus da Imunodeficiência Humana (HIV), agente etiológico da Síndrome da Imunodeficiência Adquirida (AIDS), infecta principalmente o linfócito T CD4+, uma importante célula do sistema imunológico, levando a uma imunossupressão progressiva. Os medicamentos antirretrovirais (ARV) são capazes de reduzir a replicação viral e, com isso, retardar a progressão da doença e a mortalidade, aumentando, desta forma, a sobrevida dos pacientes. Para muitos pacientes infectados com o HIV-1, a administração de combinações de medicamentos ARV, terapia antirretroviral altamente efetiva (HAART), tem êxito em suprimir a replicação viral e reverter a evolução da doença. Em alguns pacientes, entretanto, o efeito supressor da HAART é incompleto, o que geralmente leva à seleção de variantes virais com resistência aos agentes ARV. De acordo com a pressão seletiva exercida por um medicamento, o vírus pode desenvolver algumas mutações específicas, seguindo o que chamamos de “vias” ou “caminhos mutacionais” distintos. Variantes virais contendo mutações para mais de uma “via mutacional” concomitantemente são raramente observadas in vivo e in vitro, sugerindo que a coocorrência destas mutações num mesmo genoma não seja favorável ao HIV-1 (correlação negativa). A análise genotípica padrão comumente utilizada consiste na análise populacional das variantes virais, onde a sequência observada representa um consenso das diversas populações virais presentes naquele indivíduo. Para distinguirmos as populações observadas pela análise populacional fizemos uso da análise clonal pela técnica de diluição limitante, onde é possível observar as mutações presentes num único genoma. Neste estudo, detectamos, em dois pacientes, clones contendo as mutações D30N e L90M na mesma molécula do genoma viral; essas mutações também estavam acompanhadas de outras mutações compensatórias, como a N88D e a L63P. Outra observação foi a confirmação da alta correlação da mutação N88D com a mutação D30N. Investigamos também a possibilidade da presença concomitante das mutações de resistência aos análogos timidínicos (TAM). Dentre os quatro pacientes, detectados vi pela a análise populacional, que apresentavam as seis mutações das TAM, todos apresentaram estas mesmas mutações na análise clonal. Com o acúmulo das mutações de resistência aos análogos timidínicos (TAM), também observamos aumento no número e complexidade das mutações acessórias. A uniformidade e predominância dos clones em alguns pacientes sugerem que, no momento da análise clonal, amplificamos a população que foi selecionada e expandiu-se, tornando-se majoritária. Portanto, observamos que a ocorrência concomitante das mutações de vias distintas, ou seja, D30N + L90M na protease, e as seis mutações da TAM na transcriptase reversa, ainda que rara, pode ser observada em uma mesma molécula genômica de isolados da população viral intrapaciente. Em adição, esses isolados com mutações pertencentes a múltiplas vias, são preferencialmente selecionados após terapia antirretrovial prolongada, onde os pacientes são tratados com diferentes medicamentos antivirais. Concluímos também que, na análise populacional padrão, a sequência obtida corresponde à combinação de genomas de variantes presentes na população viral de um indivíduo. Essa sequência pode representar a população viral majoritária presente naquele momento, ou uma mistura de diversas sub-populações minoritárias, que se dividem em pequenos grupos na análise clonal. / For many patients infected with HIV-1, administration of combinative ARV drugs, often referred as highly active antiretroviral therapy (HAART) is succeeded by suppressing of detectable virus replication and, therefore, by reducing HIV-related morbidity and mortality. In some patients, however, the HAART suppressive effect is incomplete, which usually leads to selection of antiretroviral resistant viral variants. According to drug selective pressure, HIV-1 can develop specific mutations, leading to distinct mutational pathways. Species containing mutations from more than one mutational pathway are extremely rare, suggesting that the coexistence of these mutations in the same genome structure results in unfavorable virological effects (negative correlation). To distinguish populations previously observed in standard population analysis, clonal analysis by limited dilutions technique was used, permitting observation of present mutations in single genome copy. In the present study, we have observed that, though rare, mutations from distinct pathways can occur concomitantly in same genome molecule from intrapatient viral isolates population. In addition, viral isolates with mutations from multiple pathways are preferentially selected after prolonged antiretroviral therapy, when patients are treated with different antiviral drugs. It has been also concluded that sequences obtained from standard population analysis, corresponded to a combination of genomes from variants present in individual viral population. These consensus sequences can represent the major viral population present in that moment, or a mixture of diverse minor sub-populations, that are shared in small groups in clonal analysis.

Submitted by Ana Maria Fiscina Sampaio (fiscina@bahia.fiocruz.br) on 2012-07-20T20:52:35Z No. of bitstreams: 1 Joilton. Distribuição clonal de cepas de Escherichia coli isoladas em infecções do trato urinário adquiridas na comunidade.pdf: 892150 bytes, checksum: f9c041684e517924fdabc9c5c88c11ad (MD5) / Made available in DSpace on 2012-07-20T20:52:35Z (GMT). No. of bitstreams: 1 Joilton. Distribuição clonal de cepas de Escherichia coli isoladas em infecções do trato urinário adquiridas na comunidade.pdf: 892150 bytes, checksum: f9c041684e517924fdabc9c5c88c11ad (MD5) Previous issue date: 2010 / Fundação Oswaldo Cruz. Centro de Pesquisas Gonçalo Moniz. Salvador, Bahia, Brasil / A infecção do trato urinário adquirida na comunidade (ITU-AC) situa-se entre as mais freqüentes infecções bacterianas do ser humano e uma das principais razões para o uso de antibióticos. A Escherichia coli causa aproximadamente 80% destas infecções. Estudos recentes sugerem que as mudanças na prevalência da resistência aos antimicrobianos entre os isolados de E. coli na comunidade são mais influenciados pelo aparecimento e desaparecimento transitório de grupos clonais do que pela pressão seletiva exercida com o uso indiscriminado de determinados antimicrobianos. Objetivos: Avaliar a clonalidade das cepas de E. coli isoladas em ITU-AC, investigando o papel da clonalidade destas cepas na persistência e disseminação da resistência à ciprofloxacina. Material e Métodos: Das 463 cepas de E. coli isoladas consecutivamente de pacientes com ITU-AC atendidos em dois serviços ambulatoriais em Salvador/BA no período de 2001 a 2002, foi selecionada uma amostra de cepas resistentes à Ciprofloxacina (n=45) e outra de cepas sensíveis a todos os antimicrobianos testados (n=43). Os testes de susceptibilidade foram realizados conforme recomenda o Clinical and Laboratory Standards Institute e a clonalidade das cepas foi analisada através da comparação dos padrões de eletroforese em gel de campo pulsado (PFGE), utilizando os critérios de Tennover como estabelecido pelo Centers for Disease Control and Prevention. Resultado: Os principais grupos clonais entre as cepas resistentes à ciprofloxacina foram G, A e D que corresponderam a 42% destas e apenas a 7% das cepas sensíveis (p< 0, 001). Conclusão: Nossos dados mostram a predominância de alguns grupos clonais entre os isolados de E. coli resistentes à ciprofloxacina. Sugerindo, portanto, que a expansão de determinados clones pode desempenhar papel importante na disseminação de resistência bacteriana em ITUs-AC. / Community-acquired urinary tract infection (CA-UTI) is among the most frequent bacterial infections in humans and a major reason for antibiotic use. Escherichia coli causes approximately 80% of these infections. Recent studies suggest that changes in the prevalence of antimicrobial resistance among isolates of E. coli in the community are more influenced by appearance and disappearance of transient clonal groups than by selective pressure from indiscriminate use of certain antimicrobials. Objectives: To evaluate the clonality of strains of E. coli isolated from CA-UTI, investigating the role of clonality of these strains in the persistence and spread of resistance to ciprofloxacin. Methods: Of 463 strains of E. coli isolated consecutively from patients with CA-UTI treated at two outpatient services in Salvador, Bahia from 2001 to 2002, we selected a sample of strains resistant to ciprofloxacin (n = 45) and another sample of strains susceptible to all antimicrobials tested (n = 43). The susceptibility tests were performed as recommended by the Clinical and Laboratory Standards Institute and clonality of the strains was analyzed by comparing the electrophoresis patterns of pulsed-field gel electrophoresis (PFGE) using the criteria of Tennover as established by Centers for Disease Control and Prevention. Results: The main clonal groups of strains resistant to ciprofloxacin were G, A and D which accounted for 42% of them and comprised only 7% of susceptible strains (p <0.001). Conclusion: Our data show the predominance of some clonal groups among isolates of E. coli resistant to ciprofloxacin. Thus suggesting that the expansion of certain clones may play an important role in the spread of bacterial resistance in CA-UTI.