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Pyrrhic progress : antibiotics and western food production (1949-2013)Kirchhelle, Claas January 2015 (has links)
This dissertation addresses the history of antibiotic use in British and US food production between 1950 and 2013. Introduced to agriculture in the 1950s, antibiotics underpinned the 20th-century revolution in Western food production. However, from the late 1950s onwards, controversies over antibiotic resistance, residues and animal welfare began to tarnish antibiotics' image. By mapping both the enthusiasm and the controversies surrounding antibiotic use, this dissertation shows how distinct civic epistemologies of risk influenced consumers', producers' and officials' attitudes towards antibiotics. These differing risk perceptions did not emerge by chance: in Britain, popular animal welfare concerns fused with new scenarios of antibiotic resistance and drove reform. Following 1969, Britain pioneered antibiotic resistance regulation by banning certain feed antibiotics. However, subsequent reforms were only partially implemented, and total antibiotic consumption failed to sink. Meanwhile, scandals and public pressure forced the American FDA to install the first comprehensive monitoring program for antibiotic residues. However, differing public priorities and industrial opposition meant that the FDA failed to convince Congress of resistance-inspired bans. The transatlantic regulatory gap has since widened: following the BSE crisis, the EU phased out growth-promoting antibiotic feeds in 2006. The US proclaimed only a voluntary and partial ban of antibiotic feeds in December 2013. In the face of contemporary warnings about failing antibiotics, the dissertation shows how one group of substances acquired different meanings for different communities. It also reveals that the dilemma of antibiotic regulation is hardly new. Despite knowing about antibiotic allergies and resistance since the 1940s, no country has managed to solve the dilemma of preserving antibiotics' economic benefits whilst containing their medical risks. Historically, effective antibiotic regulation emerged only when differing perceptions of antibiotics were broken down either by sustained regulatory reform or large crises.
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Major spoligotype families of Mycobacterium tuberculosis strains isolated from tuberculosis patients in Port Elizabeth, Eastern Cape, South AfricaNqini, Babalwa J January 2012 (has links)
South Africa is burdened with tuberculosis (TB) which is aggravated by the concurrent epidemic of HIV as well as the emergence of drug resistance. In most developed countries molecular techniques have been used to look at the dynamics of the TB epidemic however, despite the prevalence that is high in sub-Saharan Africa, there is little data on strain types that are available in Port Elizabeth. This study aims to find the major clades of M. tuberculosis that are circulating in Port Elizabeth. Two hundred MDR-TB DNA samples were obtained from the National Health Laboratory Services TB laboratory in Port Elizabeth. Spoligotyping and MIRU-VNTR were used to genotype the strains. Two hundred strains were sent to the University of Stellenbosch for spoligotyping and 179 of those were typed. Spoligotype defined families were further typed by MIRU-VNTR typing, so as to further differentiate and assess clonal diversity within the spoligotype families. The Beijing family was the dominant family and the MANU family being the least dominant, with percentages of 71 percent and 0.5 percent respectively. A comparison of spoligotyping results with the international spoligotyping database (SITVIT2) showed a total of 15 shared international types. Forty four percent (44 percent) of the isolates that were typed by MIRU-VNTR showed similarities, suggesting epidemiological relatedness. Thirty eight percent of isolates from spoligotyping were from the same family, the Beijing family, with the same shared international type STI1, but when typed by 12 MIRU-VNTR they showed no epidemiological relatedness and 18 percent of the isolates showed no relatedness when typed by 12 MIRU-VNTR but spoligotyping showed that they were from the LAM family. Results from our study illustrate the effectiveness of MIRU-VNTR typing together with spoligotyping in epidemiological studies in the region of Port Elizabeth.
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Caracterização genética de isolados clínicos e ambientais de Klebsiella pneumoniaeLima, Patricia Mayer January 2011 (has links)
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Previous issue date: 2011 / Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Rio de Janeiro, RJ, Brasil. / Klebsiella sp. é uma bactéria ubíqua, responsável por infecções nosocomiais oportunistas. Linhagens multirresistentes a antibióticos têm se tornado um problema cada vez mais freqüente no mundo todo. Estudos objetivando a determinação do potencial patogênico dos isolados ambientais são escassos. K. pneumoniae de origem ambiental poderia estar atuando como reservatório de genes de resistência que eventualmente poderiam ser transferidos e levar ao aparecimento linhagens multirresistentes. Nosso objetivo é determinar o perfil de resistência aos antimicrobianos de isolados clínicos e ambientais de K. pneumoniae, determinar os genótipos circulantes e sua clonalidade e caracterizar a genética da resistência observada. A susceptibilidade a 9 classes de antibióticos foi determinada para os 76 isolados clínicos e ambientais. De modo geral, os isolados clínicos mostraram-se resistentes a maioria das classes de antibióticos testadas, enquanto os isolados ambientais mostraram-se suscetíveis às diferentes classes. A pesquisa por elementos genéticos associados a resistência a antibióticos mostrou a presença de integron de classe 1 entre os isolados clínicos e integron de classe 2 em isolados ambientais. Os principais cassetes identificados no integron de classe 1 foram acetilt- e adenil-transferases ou dihidrofolatoredutase, os cassetes mais frequentemente encontrados nessa classe. No integron de classe 2, foi caracterizado o arranjo sat-aadA. Essa é a primeira identificação de integron de classe 2 em isolado ambiental de K. pneumoniae. A caracterização da relação genética entre os isolados, utilizando MLST, mostrou a existência de 45 sequencias-tipo(STs), das quais 24 novas. A análise por MLST mostrou que existe uma linhagem principal, distribuída pelo Brasil. Identificamos STs pandêmicos: ST11, ST23, ST37, ST423 e ST437 e sua distribuição mostra a existência de complexos clonais distribuídos em diferentes regiões geográficas do Brasil. / Klebsiella sp. Are ubiquitous bacteria associated with opportunistic nosocomial infections. Multiresistant strains to antibiotics have become an increasingly common problem worldwide. Studies focused on determining the pathogenic potential of environmental isolates are scarce. K. pneumoniae environmental strains could be acting as reservoirs of resistance genes that could be transferred and eventually lead to the emergence of multiply antibiotic-resistant strains. Our aim is to determine the antimicrobial resistance profiles of clinical and environmental K. pneumoniae strains, characterize the circulating genotypes and their clonality, and investigate the presence of genetic elements associated with the resistance observed, in Brazil. The susceptibility to nine classes of antibiotics was determined for 76 clinical and environmental isolates. There is a prevalence of the multidrug resistant phenotype (MDR) within the clinical isolates, whilst the environmental isolates are susceptible to different classes of antibiotics. The search for genetic elements associated with antibiotic resistance revealed the presence of class 1 and class 2 integrons among clinical and environmental isolates, respectively. The main gene cassettes present in class 1 integrons were aac and aad (acetylt- and adenyl-transferases) or dfr (dihydrofolateredutase), the most commonly found in class 1 integrons. The class 2 integron harbored the sat-aadA arrangement. This is the first observation of class 2 integrons in environmental K. pneumoniae isolates. Using the MLST approach, the genetic relationship among the strains showed 45 sequence-types (STs), of which 24 have not been described yet. The MLST analysis revealed a major K. pneumoniae lineage distributed throughout Brazil. Pandemic STs were identified among the clinical strains: ST11, ST23, ST37, ST423 and ST437. Their distribution shows the existence of clonal complexes throughout geographic regions of Brazil.
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Conception, synthèse et évaluation des activités anthelminthiques de nouvelles molécules à support imidazo (1,2-a) pyridine / Design, synthesis and evaluation of anthelmintic activities of new acrylonitriles imidazo[1,2-α]pyridine-basedN'Guessan, Déto 14 December 2017 (has links)
Les strongyloses vétérinaires constituent l’une des principales causes de gastroentérites et d’anémie des ovins et caprins à l’origine de lourdes pertes économiques. Cependant, leurs prise en charge par les anthelminthiques existants, est confrontée à la prolifération d’une pharmacorésistance des nématodes incriminés. La première partie de ce travail de thèse présente l’ampleur du problème que pose la résistance des helminthes impliqués dans les strongyloses des petits ruminants. Elle révèle également le profil novateur des imidazo[1,2-a]pyridinyl-phénylacrylonitriles qui est proposé pour parer à l’inefficacité croissante des anthelminthiques. / Veterinary strongylosis is one of the main causes of gastroenteritis and anemia in sheep and goats causing major economic losses. However, their management by existing anthelmintics, is confronted with the proliferation of drug resistance of the nematodes incriminated. The first part of this thesis presents the magnitude of the problem posed by the resistance of helminths involved in strongylosis of small ruminants. It also reveals the innovative profile of imidazo[1,2-a]pyridinyl-phenylacrylonitriles that are proposed to counter the increasing ineffectiveness of anthelmintics.
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Spread of hospital-acquired infections and emerging multidrug resistant enterobacteriaceae in healthcare networks : assessment of the role of interfacility patient transfers on infection risks and control measures / La propagation des infections nosocomiales et des entérobactéries émergentes et multirésistantes au sein du réseau des hôpitaux : évaluation du rôle des transferts inter-établissement des patients sur le risque infectieux et les mesures de contrôleNekkab, Narimane 25 June 2018 (has links)
The spread of healthcare-associated infections (HAIs) and multi-drug resistance in healthcare networks is a major public health issue. Evaluating the role of inter-facility patient transfers that form the structure of these networks may provide insights on novel infection control measures. Identifying novel infection control strategies is especially important for multi-drug resistant pathogens such as Carbapenemase-producing Enterobacteriaceae (CPE) due to limited treatment options. The increasing use of inter-individual contact and inter-facility transfer network data in mathematical modelling of HAI spread has helped these models become more realistic; however, they remain limited to a few settings and pathogens. The main objectives of this thesis were two-fold: 1) to better understand the structure of the healthcare networks of France and their impact on HAI spread dynamics; and 2) to assess the role of transfers on the spread of CPE in France during the 2012 to 2015 period. The French healthcare networks are characterized by centralized patient flows towards hubs hospitals and a two-tier community clustering structure. We also found that networks of patients with HAIs form the same underlying structure as that of the general patient population. The number of CPE episodes have increased over time in France and projections estimate that the number of monthly episodes could continue to increase with seasonal peaks in October. The general patient network was used to show that, since 2012, patient transfers have played an increasingly important role over time in the spread of CPE in France. Multiple spreading events of CPE linked to patient transfers were also observed. Despite subtle differences in the flows of patients with an HAI and the general patient population, the general patient network may best inform novel infection control measures for pathogen spread. The structure of healthcare networks may help serve as a basis for novel infection control strategies to tackle HAIs in general but also CPE in particular. Key healthcare hubs in large metropoles and key patient flows connecting hospital communities at the local and regional level should be considered in the development of coordinated regional strategies to control pathogen spread in healthcare systems. / La propagation des infections nosocomiales (IN), notamment liées aux bactéries multi-résistantes, au sein du réseau des hôpitaux, est un grand enjeu de santé publique. L’évaluation du rôle joué par les transferts inter-établissements des patients sur cette propagation pourrait permettre l’élaboration de nouvelles mesures de contrôle. L’identification de nouvelles mesures de contrôle est particulièrement importante pour les bactéries résistantes aux antibiotiques comme les entérobactéries productrices de carbapenemase (EPC) pour lesquelles les possibilités de traitement sont très limitées. L’utilisation des données de réseaux de contact inter-individus et de transferts inter-établissement dans la modélisation mathématique ont rendu ces modèles plus proches de la réalité. Toutefois, ces derniers restent limités à quelques milieux hospitaliers et quelques pathogènes. La thèse a eu pour objectifs de 1) mieux comprendre la structure des réseaux hospitaliers français et leur impact sur la propagation des IN ; et 2) évaluer le rôle des transferts sur la propagation des EPC.Les réseaux hospitaliers français sont caractérisés par des flux de patients vers des hubs et par deux niveaux de communautés des hôpitaux. La structure du réseau de transfert des patients présentant une IN n’est pas différente de celle du réseau général de transfert des patients. Au cours des dernières années, le nombre d’épisode d’EPC a augmenté en France et les prédictions prévoient une poursuite de cette augmentation, avec des pics de saisonnalité en octobre. Ce travail a également montré que, depuis 2012, les transferts de patients jouent avec les années un rôle de plus en plus important sur la diffusion des EPC en France. Des évènements de propagation multiple liée aux transferts sont également de plus en plus souvent observés.En conséquence, la structure du réseau des hôpitaux pourrait servir de base pour la proposition des nouvelles stratégies de contrôles des IN en général, et des EPC en particulier. Les hôpitaux très connectés des grandes métropoles et les flux des patients entre les communautés locale et régionale doivent être considérés pour le développement de mesures de contrôle coordonnées entre établissements de santé.
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Fatores de risco associados à colonização nasal por Staphylococcus aureus em pessoas vivendo com HIV/aids: um estudo caso-controle / Risk factors associated with nasal colonization by Staphylococcus aureus in people living with HIV / AIDS: a case-control studyLilian Andreia Fleck Reinato 30 May 2017 (has links)
A colonização nasal por Staphylococcus aureus e a infecção pelo HIV representam problemas de saúde pública de preocupação mundial. O objetivo geral foi identificar os fatores de risco para a colonização nasal por Staphylococcus aureus em pessoas vivendo com HIV/aids. Para tanto, foi realizado um estudo tipo caso-controle, com pessoas vivendo com HIV/aids internadas nas unidades especializadas na assistência às doenças infecciosas de um hospital de ensino no interior paulista. A coleta de dados ocorreu de janeiro/2013 a fevereiro/2015, por meio de entrevista individual contemplando dados sociodemográficos e clínicos, além da coleta da secreção nasal com auxílio do swab em meio Stuart, ambos nas primeiras 24 horas de internação. As amostras foram encaminhadas e processadas pelo Laboratório de Microbiologia da própria instituição. Os critérios de inclusão foram: ter idade acima de 18 anos, ser soropositivo ao HIV, estar internado. Nas análises estatísticas foram realizados os testes qui-quadrado de Pearson, Exato de Fisher, t-Student, Wilcoxon e Regressão Logística Univariada e Multivariada, por meio do software SAS®. Os dados estão apresentados em tabelas e figuras. O presente estudo foi aprovado pelo Comitê de Ética em Pesquisa da Escola de Enfermagem de Ribeirão Preto (No CAAE 38990114.5.0000.5393) e pela instituição co-participante (No CAAE 38990114.5.3001.5440). Participaram do estudo 240 pessoas vivendo com HIV/aids, sendo 120 Casos e 120 Controles, houve predominância do sexo masculino em 65,0% dos Casos e 55,0% dos Controles, 35,8% dos Casos estavam na faixa etária de 30 a 39 anos e 45,8% dos Controles tinham idade de 40 a 49 anos, a etnia predominante foi a branca para Casos e Controles, 74,2% e 64,2%, respectivamente. Os grupos foram homogêneos entre si em relação ao sexo, etnia e escolaridade. A média do tempo de diagnóstico foi de 9 anos para Casos e 8,8 anos para Controles. O modelo final de regressão logística evidenciou como fatores de risco associados à colonização nasal por Staphylococcus aureus em pessoas vivendo com HIV/aids, ser da etnia branca, p=0,05 (OR:1,85; IC95% 1,00 - 3,57); ter carga viral >40 cópias/mL, p= 0,03 (OR: 2,90; IC95% 1,15 - 7,30); estar com contagem de LT-CD4+ <200 células/mm3 p=0,001 (OR: 2,71; IC95% 1,53 - 4,81); e apresentar doença oportunista p=0,014 (OR: 2,09; IC95% 1,20 - 3,67). Além disso, foi evidenciado como fator de proteção para a colonização nasal pelo Staphylococcus aureus em pessoas vivendo com HIV/aids o uso de antirretroviral p=0,008 (OR: 0,45; IC95% 0,25 - 0,81). Concluímos que a colonização nasal por Staphylococcus aureus nas pessoas vivendo com HIV/aids foi associada aos fatores: etnia, carga viral, contagem de LT-CD4+ , infecção oportunista e uso de antirretroviral / Staphylococcus aureus nasal colonization and HIV infection represent public health problems of global concern. The overall objective was to identify the risk factors for nasal colonization by Staphylococcus aureus in people living with HIV / AIDS. Therefore, a case-control study was conducted, with people living with HIV / AIDS hospitalized at the units specialized in infectious disease care at a teaching hospital in the interior of São Paulo. Data were collected from January / 2013 to February / 2015 by means of an individual interview, including sociodemographic and clinical data, as well as the collection of nasal secretions with the aid of swab in Stuart\'s medium, both during the first 24 hours of hospitalization. The samples were sent and processed by the Laboratory of Microbiology of the institution itself. The inclusion criteria were: to be over 18 years of age, to be known as infected HIV, to be hospitalized. Statistical analyzes were performed using the Pearson chi-square test, Fisher\'s exact test, Student t-test, Wilcoxon test, and Univariate and Multivariate logistic regression using the SAS® software. The data are presented in tables and figures. The present study was approved by the Research Ethics Committee of the Ribeirão Preto College of Nursing (CAAE 38990114.5.0000.5393) and by the co- participating institution (CAAE 38990114.5.3001.5440). A total of 240 people living with HIV / AIDS participated in the study, of which 120 were Cases and 120 Controls; 65.0% of Cases and 55.0% of Controls were male: 35.8% of Cases were in the age group of 30 at 39 years and 45.8% of the Controls were aged from 40 to 49 years, the predominant ethnicity was white for Cases and Controls, 74.2% and 64.2%, respectively. The groups were homogeneous among themselves in relation to gender, ethnicity and schooling. The mean time of diagnosis was 9 years for Cases and 8.8 years for Controls. The final logistic regression model showed that the risk factors associated with Staphylococcus aureus nasal colonization in people living with HIV / AIDS were white, p = 0.05 (OR: 1.85, 95% CI: 1.00 - 3.57); having viral load> 40 copies / mL, p = 0.03 (OR: 2.90; IC95% 1.15 - 7.30); being with LT-CD4+ <200 cells / mm3 p = 0.001 (OR: 2.71; IC95% 1.53 - 4.81); and present opportunistic disease p = 0.014 (OR: 2,09; IC95% 1,20 - 3,67). In addition, it was also obtained by the final regression final model that the use of antiretroviral therapy is a protection factor of p = 0.008 (OR: 0.45; 95% CI 0.25 - 0.81) for nasal colonization by Staphylococcus aureus. We conclude that nasal colonization by Staphylococcus aureus in people living with HIV/AIDS was associated with factors: ethnicity, viral load, LT-CD4+ count, opportunistic infection, and antiretroviral use
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Potencial antibacteriano e modulador de resistência a drogas de extratos e constituintes de algas marinhas em staphylococcus aureus / Antibacterial and Modulator Drug Resistance Potential of Extracts and Constituents Seaweed in Staphylococcus aureus.Silva, Suellen Maria Pinto de Menezes 20 February 2013 (has links)
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Previous issue date: 2013-02-20 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / The mechanism of antimicrobial resistance is a genetic phenomenon related to the existence of genes contained in the microorganism that encode proteins responsible for biochemical mechanisms that prevent the action of drugs. The increasing incidence of resistant bacteria has undermined the therapeutic value of available antibacterials, creating the necessity, increasingly, the search for alternatives that can reverse or decrease the resistance, as the search for inhibitors of resistance mechanisms. Efflux pumps, which are transmembrane proteins involved in transport of substrates toxic, has been responsible for many cases of bacterial resistance to antibiotics and being associated with multidrug resistance. "Modifiers of drug resistance", "Modifiers of antibiotic activity" and "Adjuvant antibiotic" are terms used for drugs that modulate bacterial resistance to antibiotics, which may act by inhibiting the efflux system. In the present study, we evaluated extracts of Dictyota pulchella and Sargassum polyceratium and their isolated compounds, diterpene and pheophytin as possible efflux pump inhibitors; extracts: Gracilaria cervicornis, Sargassum polyceratiu,; Mexican Caulerpa, Caulerpa kempfii, hondrophycus papillosus, Dictyota pulchella and Sargassum polyceratium with antibacterial activity mediated by UV- A Light. We used bacterial strains expressing the gene norA, msrA or tetK encoding efflux proteins for some compounds, such as norfloxacin (Nora), erythromycin (MSRA) and tetracycline (TetK), respectively. Through the microdilution technique using nutrient broth, were determined values of minimum inhibitory concentrations (MIC) of antibiotics, algae extracts and constituents, and to evaluate the activity modulator, MICs of the antibiotics were determined in the absence and presence of concentrations subinibitory natural products. None of the extracts or constituents tested showed significant antibacterial activity (MIC ≥ 256μg/mL), however, two of the extracts, Dictyota and Sargassum and their constituents phaeophytin and diterpene showed modulatory activity in the strains tested. They reduced values between 2 and 16 times. The extracts of Dictyota and Sargassum also showed antibacterial activity median for light. The results presented here describe for the first time tested these extracts and constituents acting as a putative inhibitor of the efflux system in bacteria, and also phototoxic activity. Therefore, natural products seaweed may serve as source products which modulate the bacterial resistance, ie as antibiotics adjuvants potential. / O mecanismo de resistência aos antimicrobianos é um fenômeno genético relacionado à existência de genes contidos no microrganismo que codificam diferentes proteínas, responsáveis por mecanismos bioquímicos que impedem a ação das drogas. A crescente incidência de bactérias resistentes tem minado o valor terapêutico dos antibacterianos existentes, criando a necessidade, cada vez maior, da busca por alternativas capazes de reverter ou diminuir a resistência. Bombas de efluxo, que são proteínas transmembrana envolvidas no transporte de substratos tóxicos, tem sido responsabilizada por diversos casos de resistência bacteriana a antibióticos, sendo associada à resistência a múltiplas drogas. Modificadores da resistência à drogas , Modificadores da atividade antibiótica e Adjuvantes de antibióticos são termos utilizados para drogas que modulam a resistência bacteriana a certos antibióticos, os quais podem agir inibindo o sistema de efluxo. No presente trabalho, foram avaliados: extratos de Dictyota pulchella e Sargassum polyceratium, bem como os respectivos compostos isolados, diterpeno e feofitina, como possíveis inibidores da bomba de efluxo; extratos de: Gracilaria cervicornis, Sargassum polyceratiu,; Caulerpa mexicana, Caulerpa kempfii, Chondrophycus papillosus, Dictyota pulchella e Sargassum polyceratium com atividade antibacteriana mediada por Luz UV-A. As linhagens bacterianas utilizadas expressam o gene norA, msrA ou tetK codificadores das proteínas de efluxo para alguns compostos, como: norfloxacina (NorA), eritromicina (MsrA) e tetraciclina (TetK), respectivamente. Foram determinados por meio da técnica de microdiluição em caldo nutriente os valores das concentrações inibitória mínima (CIM) dos antibióticos, extratos e constituintes de algas, e para avaliar a atividade moduladora, as CIM dos antibióticos foram determinadas na ausência e na presença de concentrações subinibitórias dos produtos naturais. Nenhum dos extratos ou constituintes ensaiados mostrou atividade antibacteriana relevante (CIM ≥ 256μg/mL), no entanto, dois dos extratos, Dictyota e Sargassum e seus respectivos constituintes diterpeno e feofitina, apresentaram atividade moduladora nas linhagens ensaiadas. Eles reduziram os valores entre 2 e 16 vezes. Os extratos de Dictyota e Sargassum também apresentaram atividade antibacteriana mediana por luz. Os resultados aqui apresentados relatam pela primeira vez a esses extratos e constituintes testados agindo como um putativo inibidor do sistema de efluxo em bactérias, e também com atividade fototóxica. Logo, produtos naturais da flora algológica podem servir como fonte de produtos que modulam a resistência bacteriana, ou seja, como potenciais adjuvantes de antibióticos.
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Proteomika jako nástroj studia molekulárních mechanizmů závažných onemocnění / Proteomics as a tool for understanding molecular mechanisms of human diseasesPospíšilová, Jana January 2014 (has links)
Proteomics is a set of analytical methods which enable qualitative and quantitative characterization of the proteome. Expression proteomics quantitatively compares proteomes of cells, tissues, body fluids or other biological materials to find differencies in protein expression and, based on these differencies, to describe the biological processes occuring in investigated organisms. An initial material for expression proteomic studies are complex mixtures containing thousands of proteins, which are analyzed using separation (electrophoretic and chromatographic) methods, and identified, possibly quantified using mass spectrometry. The aim of this Thesis is to demonstrate the application of the tools of expression proteomics in solving diverse challenges in biomedicine. We employed various proteomic approaches and tools for studying molecular mechanisms of human diseases using pacient biological samples, or a model organism and a cell culture. We were conducting three different research projects, namely: A quest for potencial molecular targets for selective elimination of TRAIL-resistant mantle cell lymphoma cells; Investigation of molecular mechanisms of heart failure using a rat model of the disease induced by volume overload; and Searching for diagnostically usable serum biomarkers of ovarian...
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Caracterização molecular de isolados de Staphylococcus aureus resistentes à meticilina (MRSA) obtidos de colonização e infecção de pacientes hepatopatas e transplantados hepáticos / Molecular characterization of methicillin-resistant Staphylococcus aureus (MRSA) isolates obtained from colonized and infected patients with liver diseases and liver transplantedInneke Marie van der Heijden 30 October 2014 (has links)
MRSA é um importante agente de colonização e infecção em pacientes hepatopatas e transplantados de fígado. Este estudo tem como objetivo avaliar a clonalidade e a virulência de isolados MRSA de pacientes hepatopatas atendidos no Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo. De agosto de 2010 a janeiro de 2012, foram coletados swabs nasais e inguinais de 190 pacientes (126 pré-transplante e 64 de pós-transplante). Isolados de MRSA foram identificados fenotipicamente e foi realizada detecção de genes de virulência, caracterização do tipo de SCCmec, análise de polimorfismo genômico por PFGE e técnica de microarranjo. Além disso, determinou-se a CIM para dez antimicrobianos pelo método de microdiluição em caldo. MRSA foi detectado em 20% dos pacientes pelo método de cultura e em 82% por PCRs. Apenas três pacientes colonizados desenvolveram infecção após o transplante. Entre os 69 isolados de MRSA, 42,0% (29/69) apresentaram SCCmec tipo II, 20,3% (14/69) SCCmec tipo I, 20,3% (14/69) SCCmec tipo III, 13,0% (9/69) SCCmec tipo IVa, 2,9% (2/69) SCCmec tipo IV e 1,5% (1/69) SCCmec tipo V. O gene tst foi detectado em 5,8% (4/69) dos isolados MRSA e todos eles foram definidos como SCCmec tipo I. Outros genes identificados por PCR foram: lukD (89,9%; 62/69), lukE (89,9%; 62/69), clf (91,3%; 63/69) e fnbA (89,9%; 62/69). A análise por PFGE dos 69 isolados mostrou a presença de um clone predominante chamado cluster A em 36,2% (25/69) e este cluster apresentou 84,6% de similaridade com o clone NewYork/Japan (BK2464). O dendrograma demonstrou também a presença de um cluster relacionado com BEC (Clone Endêmico Brasileiro) HSJ216. Atualmente o tipo de SCCmec mais prevalente em nosso hospital é o tipo II. Neste estudo, observou-se a presença de isolados virulentos tanto em pacientes hepatopatas como em pacientes transplantados. Nossos resultados mostraram que o clone predominante (cluster A) apresentou diferentes genes de virulência (genes fnbA, clf e lukD-lukE) e foi resistente a pelo menos seis diferentes drogas, além de ser caracterizado como HA-MRSA SCCmec tipo II. Em conclusão, a técnica de microarranjo permite a genotipagem e detecção de genes estafilocócicos clinicamente relevantes, e pode, na maioria dos casos, ser utilizada como uma importante ferramenta para a triagem da virulência e resistência a antimicrobianos em isolados de MRSA / MRSA is an important agent of colonization and infection in patients with liver disease and liver transplant. This study aims to evaluate clonality and virulence of MRSA isolates from liver diseases patients treated at Hospital of Clinics Faculty of Medicine from University of Sao Paulo. From August 2010 to January 2012, we collected nasal and groin swabs from 190 patients (126 pre-liver and 64 post-liver). MRSA isolates were identified phenotypically and the detection of virulence genes, characterization of SCCmec type, microarray and genomic polymorphism analysis by PFGE were done. In addition, it was determined the MIC for ten antibiotics by broth microdillution method. MRSA was detected in 20% patients by culture method and 82% by PCR. Only three patients colonized developed infection post-transplantation. Among the 69 MRSA isolates, 42.0% (29/69) had type II SCCmec, 20.3% (14/69) SCCmec type I, 20.3% (14/69) SCCmec type III, 13.0% (9/69) SCCmec type IVa, 2.9% (2/69) SCCmec type IV and 1.5% (1/69) SCCmec type V. The tst gene was detected in 5.8% (4/69) of MRSA isolates and all of them were defined as SCCmec type I. Other genes were identified by PCR: lukD (89.9%; 62/69), lukE (89.9%; 62/69), clf (91.3%; 63/69) and fnbA (89.9%; 62/69). The PFGE analysis of 69 isolates showed the presence of a predominant cluster named cluster A in 36.2% (25/69) and this cluster had 84.6% similarity with New York/Japan clone (BK2464). Dendrogram also demonstrated presence of one cluster related with BEC (Brazilian Endemic Clone) HSJ216. Currently the most prevalent SCCmec type in our hospital is type II. In this study, we observed virulent isolates in pre and post-transplantation patients. Our results showed that the predominant clone (cluster A) had different virulence genes (genes fnbA, clf and lukD-lukE) and was resistant to at least six different drugs, in addition to being characterized as HA-MRSA SCCmec type II. In conclusion, microarray profiling allows genotyping and detection of clinically relevant staphylococcal genes, and can, in most cases, be used as an important tool to screening virulence and antibiotic resistance genes in MRSA isolates
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Identificação de polimorfismos e mutações primárias de resistência aos inibidores de protease (NS3/NS4A) no vírus da hepatite C em pacientes com hepatite C crônica monoinfectados e coinfectados pelo vírus da imunodeficiência humana / Characterization of NS3/NS4A polymorphisms and hepatitis C protease inhibitors resistance-associated mutations in hepatitis C virus monoinfected and human immunodeficiency virus coinfected patientsGaspar Lisbôa Neto 12 April 2017 (has links)
INTRODUÇÃO: A hepatite C crônica é uma das principais causas de hepatopatia em todo mundo. A coinfecção pelo vírus C (VHC) e o HIV não é incomum, pois ambos compartilham vias similares de transmissão. Recentemente, a terapêutica da hepatite C crônica foi radicalmente modificada com o advento das drogas antivirais de ação direta (DAAs), elevando as taxas de RVS mesmo na população coinfectada. O VHC é caracterizado pela sua alta taxa replicativa e por grande diversidade populacional. Substituições de ocorrência natural na protease viral associadas a resistência podem comprometer a terapêutica em alguns regimes baseados no uso de inibidores de protease (IPs). OBJETIVOS: Estimar a prevalência de polimorfismos e mutações de ocorrência natural associadas a resistência aos IPs em pacientes monoinfectados e coinfectados pelo VHC e HIV e identificar fatores clínicos e virológicos associados a presença de tais substituições. MATERIAIS E MÉTODOS: Dados epidemiológicos e clínicos foram obtidos de 247 pacientes (135 monoinfectados e 112 coinfectados pelo VHC e HIV). VHC RNA foi extraído do plasma dos indivíduos participantes e um fragmento de 765 pares de base da região NS3 foi amplificado e sequenciado por metodologia populacional (técnica de Sanger). O estadiamento da fibrose hepática foi realizado pelo escore não invasivo FIB- 4. RESULTADOS: 54 indivíduos (21,9%) apresentaram pelo menos uma substituição na região NS3/NS4A do VHC. Somente 14 pacientes (5,7%) apresentaram pelo menos uma mutação de resistência aos IPs (T54S, V55A ou Q80R). A Q80K não foi identificada em nenhuma das amostras. Não houve diferença entre monoinfectados e coinfectados quanto à ocorrência de polimorfismos ou mutações associadas a resistência. As variáveis independentemente associadas com substituições na região da protease foram infecção pelo VHC genótipo 1b, bilirrubinas totais > 1,5 vezes o LSN e níveis de albumina < 3,5 g/dL. Fibrose hepática avançada (FIB-4 > 3.25) não esteve associada a presença de substituições. A análise de diversidade nucleotídica na protease viral revelou maior heterogeneidade do VHC genótipo 1b em relação ao 1a. Contudo, a análise de pressão seletiva não demonstrou maior variabilidade de quasiespécies no grupo de hepatopatia avançada, achado este compatível com uma sequência genômica relativamente conservada. CONCLUSÕES: As substituições na região NS3/NS4 do VHC consistiram majoritariamente por polimorfismos naturais sem impacto clínico num eventual tratamento que envolva o uso de IPs. A prevalência de substituições associadas a resistência foi baixa e compatível com os valores informados pela maioria dos estudos nacionais e internacionais. A coinfecção pelo HIV não parece elevar a frequência de substituições na protease do VHC. A região NS3 do genótipo 1b foi altamente variável em relação ao genótipo 1a, reforçando o conceito de possíveis diferenças geográficas em relação ao perfil genético deste vírus / INTRODUCTION: Chronic hepatitis C is a major cause of liver disease worldwide. Hepatitis C vírus (HCV) and HIV coinfection is not uncommon due to similar transmission routes. Recently developed direct-acting antivirals drugs (DAAs) have increased the rate of SVR even in coinfected patients. HCV has a high replication rate and a lack of proofreading activity, leading to a greatly diverse viral population. Baseline spontaneously occurring resistance substitutions in the protease region may impair the rate of success in some protease inhibitors (PI) based regimens. OBJECTIVE: to determine the prevalence of naturally occurring polymorphisms and resistance associated variants to HCV PIs in mono and coinfected HCV HIV patients and to evaluate potential associations between amino acid substitutions in protease domain and clinical / virological features of those patients. METHODS: Clinical and epidemiological data were retrieved from medical records of 247 subjects in Brazil (135 HCV monoinfected and 112 HIV HCV coinfected patients). HCV-RNA was extracted from plasma and a fragment of 765 base pairs from the NS3 region was amplified and sequenced with Sanger-based technology. Fibrosis staging was assessed by non invasive score (FIB-4). RESULTS: Overall, 54 patients (21.9%) had at least one amino acid substitution in the NS3 region; only 14 patients (5.7%) harboured at least one resistance mutation (T54S, V55A, Q80R). Q80K mutation was not found in any sample. There was no difference between monoinfected and coinfected patients regarding the frequency of natural polymorphisms and resistance mutations. Variables independently associated with amino acid substitution were HCV subtype 1b, total bilirubin level > 1.5 ULN and albumin level < 3.5 g/dL. Advanced liver fibrosis (FIB-4 > 3.25) was not related to NS3 polymorphisms nor resistance associated variants. Examination of HCV protease nucleotide diversity revealed greater heterogeneity in subtype 1b than subtype 1a. Analysis of selective pressure did not reveal a greater quasispecies variability in advanced liver fibrosis group, being such finding consistent with a relatively conserved gene in this setting. CONCLUSION: Baseline HCV NS3 amino acid substitutions depicted herein were considered mostly natural polymorphisms with no clinical impact in a PI based therapy. The prevalence of resistance-associated substitutions was low and compatible with values reported by most national and international studies. HIV coinfection was not associated with a greater frequency of such substitutions in the studied sample. The NS3 region of genotype 1b was highly variable in relation to genotype 1a, highlighting geographic differences concerning HCV genetic profile
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