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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.
1

ProduÃÃo de biossurfactantes a partir da glicerina obtida da produÃÃo de biodiesel / Production of biosurfactants from glycerin obtained from biodiesel production

Juliana Rabelo de Sousa 28 February 2008 (has links)
Conselho Nacional de Desenvolvimento CientÃfico e TecnolÃgico / O objetivo deste trabalho foi avaliar a glicerina resultante da transesterificaÃÃo do Ãleo de mamona como fonte de carbono e nutrientes para P. aeruginosa LAMI. O efeito da concentraÃÃo de nutrientes e de condiÃÃes ambientais foi avaliado de acordo com dois planejamentos fatoriais completos sobre o crescimento celular, produÃÃo de biossurfactante e propriedades tensoativas do surfactante produzido. A anÃlise estatÃstica dos dados foi realizada pelo software Statistica 6.0. Avaliou-se o efeito da concentraÃÃo de glicerina e de nitrato de sÃdio e do tamanho do inÃculo, de acordo com um planejamento fatorial 23. Uma anÃlise dos efeitos mostrou que o aumento da concentraÃÃo de nitrato e a reduÃÃo da concentraÃÃo de glicerina favoreceram a produÃÃo de biossurfactantes atingindo-se uma concentraÃÃo mÃxima de 1,6 g/L de ramnose. A partir deste resultado, realizou-se um planejamento fatorial completo 24 avaliando-se os fatores concentraÃÃo de nitrato e de fosfato, pH e temperatura. Os resultados mostraram que a reduÃÃo da razÃo carbono/nitrogÃnio (C/N), com um Ãtimo equivalente a 12, favoreceu a produÃÃo de ramnolipÃdeos por P. aeruginosa LAMI, bem como a reduÃÃo da concentraÃÃo de fosfato em pH 7,0 e temperatura de 37 ÂC. Nestas condiÃÃes obteve-se 2,3 g/L de ramnose, atingindo-se coeficientes de rendimento em termos de substrato (YP/S) e de biomassa (YP/X) de 0,103 g/g e 3,13 g/g,respectivamente. A produtividade volumÃtrica mÃxima foi 31,94 mg/Lh. A cinÃtica de crescimento celular e produÃÃo de biossurfactantes foi avaliada, variando-se a razÃo C/N de 21 a 86. Os perfis de produÃÃo de biomassa e de ramnolipÃdeos sugeriram uma cinÃtica mista, semiassociada ao crescimento. O biossurfactante obtido de acordo com a melhor condiÃÃo de cultivo foi capaz de formar emulsÃes com querosene, Ãleo de soja, Ãster metÃlico e Ãleo naftÃnico, com Ãndice de emulsificaÃÃo de, aproximadamente, 60 %. Uma atividade emulsificante equivalente a 3,25 unidades mostrou que o biossurfactante foi capaz de formar emulsÃes Ãleo-Ãgua. O biossurfactante foi extraÃdo do meio de cultivo livre de cÃlulas e submetido a purificaÃÃo por cromatografia. A cromatografia em camada delgada mostrou a presenÃa de dois produtos majoritÃrios. O espectro de ressonÃncia magnÃtica nuclear H1 apresentou deslocamentos quÃmicos caracterÃsticos de grupamentos quÃmicos que constituem uma molÃcula de diramnolipÃdeo tipo Rha-Rha-C10C10. Entretanto, a elucidaÃÃo completa da estrutura do ramnolipÃdeo deve ser complementada por anÃlises espectroscÃpicas de maior resoluÃÃo / The aim of this work was analysing the glycerine from castor oil transesterification as a source of carbon and nutrients to P. aeruginosa LAMI. Nutrients concentration and environmental conditions were studied using two complete factorial planning, with cellular growth, biosurfactant production and product surface active properties as response variables. The statistic analysis was done using the software Statistica 6.0. First of all, inoculum size and concentrations of glycerine and NaNO3 were analysed with a 23 factorial planning. The increase in nitrate concentration and a decrease in glycerine concentration favored biosurfactants production, reaching a maximum rhamnose concentration of 1.6 g/L. A complete 24 factorial planning was planned based on these results. Nitrate and phosphate concentrations, pH and temperature were selected factors. Results showed that a decrease in carbon/nitrogen ratio, with an optimum of 12, and phosphate concentration favored rhamnolipid production by P. aeruginosa LAMI at pH 7,0 and 37 ÂC. A rhamnose concentration of 2.3 g/l was obtained, with product yields on substrate and biomass of 0.103 and 3.13g/g,respectively. The volumetric productivity was 31.94 mg/L.h. The influence of carbon/nitrogen ration, from 21 to 86, on growth kinetics and biosurfactant production was studied. Biomass and rhamnolipids production behavior suggest a mixed kinetics, semi-associated to growth. The biosurfactant produced using the optimized conditions formed emulsions with kerosene, soybean oil, methyl esters (biodiesel) and naphtenic oil, with emulsification index of about 60%. An emulsification activity of 3.25 units was also obtained, showing that the biosurfactant may be used to forme oil-water emulsions. Finally, the biosurfactant was extracted from a free-cell fermented medium and submited to chromatographic purification. The analytical thin layer chromatography showed the presence of two mainly products. The H1 nuclear magnetic spectra showed characteristic signals of chemical groups that are typical of a dirhamnolipid Rha-Rha-C10C10 molecule. However, a complete explanation of the rhamnolipid structure must be completed by high resolution spectroscopy analysis
2

Comparison of Aspartate Transcarbamoylase Activity Between Pseudomonas Aeruginosa Which Has One Chromosome and Burkholderia Cepacia Which Has Three Chromosomes

Nusair, Arwa Y. 08 1900 (has links)
The pyrimidine biosynthetic pathway is essential and similar in all bacteria. The pathway from Pseudomonas is regulated by nucleotides which bind to the upstream region of the pyrBC’ gene complex. Work in our lab mapped the genes and showed that the pyrB and pyrC’ were part of an overlap complex. The Pseudomonas aeruginosa has one circular chromosome. A former Pseudomonas now called Burkholderia cepacia is similar to P. aeruginosa except that it contains three circular chromosomes (CI, CII, CIII) and one large plasmid. The primary chromosome named CI contains the pyrBC’. To our knowledge there has been no report of the activity of ATCase in Pseudomonas and contrasted with that of Burkholderia. Here, we compare the activity of ATCase in P. aeruginosa and B .cepacia. Cells of both organisms were grown in Pseudomonas minimal medium and in Enriched medium. The ATCase was extracted and partially purified from each sample. It is hypothesized that the B. cepacia has greater activity for ATCase than do the Pseudomonas.
3

Degradation of n-alkane fractions of Omani crude oil by bacteria

Al-Hadhrami, Mohamed Nasser January 1995 (has links)
No description available.
4

Estudo da atividade de chalconas no controle de biofilmes bacterianos / Study of chalcones activity in the control of bacterial biofilms

Bocelli, Marcio David 16 September 2016 (has links)
Os biofilmes constituem uma forma de crescimento que permite a maior sobrevivência e resistência de microrganismos a agentes de controle como antibióticos e desinfetantes. Apesar da grande disponibilidade de agentes antimicrobianos no mercado, há escassez de produtos específicos e efetivos na erradicação/inibição de biofilmes. Existe atualmente grande interesse na seleção de moléculas capazes de inibir o crescimento dos biofilmes ou removê-los quando já estabelecidos. Doenças como fibrose cística (P. aeruginosa) e cárie dentária (S. mutans), são patologias intrinsecamente ligadas à formação de biofilmes. O principal objetivo deste trabalho foi avaliar o potencial de chalconas sintéticas e derivados no controle e erradicação de biofilmes. As chalconas foram testadas quanto à capacidade de inibir a formação de biofilme e de remover biofilmes pré-estabelecidos. Os biofilmes de P. aeruginosa foram inibidos pela presença da molécula (E)-1-(3-hidroxinaftalen-2-il)-3-fenilprop-2-em-1-ona (11), mostrando redução de 48,8% na biomassa e 60,2% na viabilidade. A redução máxima na biomassa atingiu 70,9%. Já para o tratamento de biofilmes pré-estabelecidos, a molécula (1E,4E)-1,5-difenilpenta-1,4-dien-3-ona (10) mostrou redução de 53,5% na biomassa do biofilme de P. aeruginosa. Na formação do biofilme de S. mutans, a presença da molécula (1E, 4E)-1,5-bis(4-bromofenil)penta-1,4-dien-3-ona (15) reduziu a biomassa em 67,4%. Em concentrações elevadas essa redução chegou a 95,1%. Em biofilmes pré-estabelecidos de S. mutans, o tratamento com a molécula (2E,4E)-1,5-difenilpenta-2,4-dien-1-ona (12) reduziu a biomassa celular em 62,7%, e a viabilidade celular em 58,4%. Já a molécula (E)-3-(2-hidroxifenil)-1-fenilprop-2-en-1-ona (21), quando utilizada no tratamento de biofilmes pré-estabelecidos, mostrou redução de 26,4% na biomassa e 91,6% na viabilidade de S. mutans; além de evidenciar danos à estrutura celular do microrganismo. Todas as moléculas supracitadas promoveram redução na espessura dos biofilmes. Os antibióticos ampicilina e polimixina foram menos eficientes na remoção de biofilmes comparativamente às moléculas testadas. As moléculas não apresentaram CIM frente às bactérias, entretanto, afetaram a viabilidade celular. O tratamento da superfície de poliestireno com as chalconas não impediu a adesão das bactérias, e resultou na redução da hidrofobicidade do material. A superfície celular de S. mutans apresentou predomínio de cargas negativas e forte caráter hidrofóbico enquanto que P. aeruginosa apresentou baixa hidrofobicidade além de caráter básico. Os resultados evidenciam a potencialidade do uso das chalconas e seus derivados para o controle e erradicação de biofilmes Streptococcus mutans e Pseudomonas aeruginosa. / Biofilms constitute a growth mode which allows greatest survival and resistance of microorganisms to antibiotics and disinfectants. Despite the wide availability of antimicrobial agents in the market, there are few specific and effective products to the eradication / inhibition of biofilms. Thus, there is a great interest in the search of molecules able to inhibit biofilms or remove them once established. Diseases such as cystic fibrosis (P. aeruginosa) and dental caries (S. mutans), are intrinsically linked to the formation of biofilms. The aim of this study was to evaluate the potential of chalcones and their synthetic derivatives to the control and eradication of biofilms. The chalcones were tested for the ability to inhibit biofilm formation and also to remove pre-established biofilms. Biofilms of P. aeruginosa was inhibited by the presence of the molecule (E) -1- (3-hydroxynaphthalen-2-yl) -3-phenylprop-2-en-1-one (11) showing reduction of 48.8% biomass and 60.2% viability. The maximum reduction in biomass reached 70.9%. For the treatment of pre-established biofilms, the molecule (1E, 4E) -1,5-difenilpenta-1,4-dien-3-one (10) showed a 53.5% reduction in biomass of P. aeruginosa biofilm. Biofilms of S. mutans, growing in the the presence of the molecule (1E, 4E) -1,5-bis (4-bromophenyl) penta-1,4-dien-3-one (15) showed a biomass reduction of 67.4 %. At higher concentrations this reduction reached 95.1%. In pre-established biofilms of S. mutans, treatment with the molecule (2E, 4E) -1,5-difenilpenta-2,4-dien-1-one (12) reduced cell biomass in 62.7%, and cell viability by 58.4%. The molecule (E) -3- (2-hydroxyphenyl) -1-phenylprop-2-en-1-one (21), when used in the treatment of pre-established biofilms, showed 26.4% reduction in biomass and 91.6% in the viability of S. mutans; furthermore, the chalcone 21 caused damage to the cellular structure of the microorganism. All the aforementioned molecules promoted a reduction in the thickness of biofilms. The antibiotics polymyxin and ampicillin were less efficient on removing biofilms comparatively to the chalcones. The molecules affected cell viability however, no MIC was observed under the range of concentrations evaluated. The treatment of the polystyrene surface with chalcones did not prevent bacterial adhesion moreover, hydrophobicity of the material was reduced. S. mutans cell surface showed a predominance of negative charges and strong hydrophobic character while P. aeruginosa showed low hydrophobicity and basic character. The results demonstrate that synthetic chalcones and derivatives are potential candidates to the control and eradication of Streptococcus mutans and Pseudomonas aeruginosa biofilms.
5

Estudo da atividade de chalconas no controle de biofilmes bacterianos / Study of chalcones activity in the control of bacterial biofilms

Marcio David Bocelli 16 September 2016 (has links)
Os biofilmes constituem uma forma de crescimento que permite a maior sobrevivência e resistência de microrganismos a agentes de controle como antibióticos e desinfetantes. Apesar da grande disponibilidade de agentes antimicrobianos no mercado, há escassez de produtos específicos e efetivos na erradicação/inibição de biofilmes. Existe atualmente grande interesse na seleção de moléculas capazes de inibir o crescimento dos biofilmes ou removê-los quando já estabelecidos. Doenças como fibrose cística (P. aeruginosa) e cárie dentária (S. mutans), são patologias intrinsecamente ligadas à formação de biofilmes. O principal objetivo deste trabalho foi avaliar o potencial de chalconas sintéticas e derivados no controle e erradicação de biofilmes. As chalconas foram testadas quanto à capacidade de inibir a formação de biofilme e de remover biofilmes pré-estabelecidos. Os biofilmes de P. aeruginosa foram inibidos pela presença da molécula (E)-1-(3-hidroxinaftalen-2-il)-3-fenilprop-2-em-1-ona (11), mostrando redução de 48,8% na biomassa e 60,2% na viabilidade. A redução máxima na biomassa atingiu 70,9%. Já para o tratamento de biofilmes pré-estabelecidos, a molécula (1E,4E)-1,5-difenilpenta-1,4-dien-3-ona (10) mostrou redução de 53,5% na biomassa do biofilme de P. aeruginosa. Na formação do biofilme de S. mutans, a presença da molécula (1E, 4E)-1,5-bis(4-bromofenil)penta-1,4-dien-3-ona (15) reduziu a biomassa em 67,4%. Em concentrações elevadas essa redução chegou a 95,1%. Em biofilmes pré-estabelecidos de S. mutans, o tratamento com a molécula (2E,4E)-1,5-difenilpenta-2,4-dien-1-ona (12) reduziu a biomassa celular em 62,7%, e a viabilidade celular em 58,4%. Já a molécula (E)-3-(2-hidroxifenil)-1-fenilprop-2-en-1-ona (21), quando utilizada no tratamento de biofilmes pré-estabelecidos, mostrou redução de 26,4% na biomassa e 91,6% na viabilidade de S. mutans; além de evidenciar danos à estrutura celular do microrganismo. Todas as moléculas supracitadas promoveram redução na espessura dos biofilmes. Os antibióticos ampicilina e polimixina foram menos eficientes na remoção de biofilmes comparativamente às moléculas testadas. As moléculas não apresentaram CIM frente às bactérias, entretanto, afetaram a viabilidade celular. O tratamento da superfície de poliestireno com as chalconas não impediu a adesão das bactérias, e resultou na redução da hidrofobicidade do material. A superfície celular de S. mutans apresentou predomínio de cargas negativas e forte caráter hidrofóbico enquanto que P. aeruginosa apresentou baixa hidrofobicidade além de caráter básico. Os resultados evidenciam a potencialidade do uso das chalconas e seus derivados para o controle e erradicação de biofilmes Streptococcus mutans e Pseudomonas aeruginosa. / Biofilms constitute a growth mode which allows greatest survival and resistance of microorganisms to antibiotics and disinfectants. Despite the wide availability of antimicrobial agents in the market, there are few specific and effective products to the eradication / inhibition of biofilms. Thus, there is a great interest in the search of molecules able to inhibit biofilms or remove them once established. Diseases such as cystic fibrosis (P. aeruginosa) and dental caries (S. mutans), are intrinsically linked to the formation of biofilms. The aim of this study was to evaluate the potential of chalcones and their synthetic derivatives to the control and eradication of biofilms. The chalcones were tested for the ability to inhibit biofilm formation and also to remove pre-established biofilms. Biofilms of P. aeruginosa was inhibited by the presence of the molecule (E) -1- (3-hydroxynaphthalen-2-yl) -3-phenylprop-2-en-1-one (11) showing reduction of 48.8% biomass and 60.2% viability. The maximum reduction in biomass reached 70.9%. For the treatment of pre-established biofilms, the molecule (1E, 4E) -1,5-difenilpenta-1,4-dien-3-one (10) showed a 53.5% reduction in biomass of P. aeruginosa biofilm. Biofilms of S. mutans, growing in the the presence of the molecule (1E, 4E) -1,5-bis (4-bromophenyl) penta-1,4-dien-3-one (15) showed a biomass reduction of 67.4 %. At higher concentrations this reduction reached 95.1%. In pre-established biofilms of S. mutans, treatment with the molecule (2E, 4E) -1,5-difenilpenta-2,4-dien-1-one (12) reduced cell biomass in 62.7%, and cell viability by 58.4%. The molecule (E) -3- (2-hydroxyphenyl) -1-phenylprop-2-en-1-one (21), when used in the treatment of pre-established biofilms, showed 26.4% reduction in biomass and 91.6% in the viability of S. mutans; furthermore, the chalcone 21 caused damage to the cellular structure of the microorganism. All the aforementioned molecules promoted a reduction in the thickness of biofilms. The antibiotics polymyxin and ampicillin were less efficient on removing biofilms comparatively to the chalcones. The molecules affected cell viability however, no MIC was observed under the range of concentrations evaluated. The treatment of the polystyrene surface with chalcones did not prevent bacterial adhesion moreover, hydrophobicity of the material was reduced. S. mutans cell surface showed a predominance of negative charges and strong hydrophobic character while P. aeruginosa showed low hydrophobicity and basic character. The results demonstrate that synthetic chalcones and derivatives are potential candidates to the control and eradication of Streptococcus mutans and Pseudomonas aeruginosa biofilms.
6

Comprehensive study of new virulent bacteriophages : from transcriptomic and mechanistic characterisations towards evolutionary perspectives / Étude globale de deux nouveaux bactériophages : caractérisations transcriptomique, mécanistique et perspectives évolutives

Chevallereau, Anne 19 May 2017 (has links)
Soutenue par le renouveau de la phagothérapie, la découverte de nouveaux bactériophages (phages) nous a permis de définir deux nouveaux genres de virus dénommés Kpp10virus et Pakpunavirus dont les mécanismes infectieux sont inconnus. Il est admis que le succès d’un cycle infectieux est notamment assuré par une réappropriation efficace des ressources de la cellule hôte, conduisant à sa transformation en « virocellule », c’est-à-dire, un organisme cellulaire exclusivement dédié à la production de particules virales. Ce travail de thèse a pour objectif d’apporter une vision globale des stratégies moléculaires utilisées par les virus appartenant aux genres Kpp10virus et Pakpunavirus (respectivement représentés par les phages PAK_P3 et PAK_P4) pour infecter le pathogène opportuniste Pseudomonas aeruginosa. Dans un premier temps, nous avons évalué leurs propriétés intrinsèques en analysant le contenu de leurs génomes, leurs spectres d’hôtes, leurs paramètres de croissance ainsi qu’en identifiant leur récepteur bactérien. Dans un second temps, une combinaison d’approches transcriptomiques et métabolomiques a permis de montrer que ces deux virus ont des programmes transcriptionnels similaires, incluant notamment une régulation temporelle de leur expression génétique et la production de transcrits antisens. De plus, ils provoquent tous deux la dégradation rapide de 90% des ARNm de l’hôte, qui sont alors remplacés par des ARNm viraux. Malgré cette dégradation, nous avons constaté que ces deux phages redirigent les voies de biosynthèse bactériennes plutôt que de provoquer une extinction totale du métabolisme cellulaire, en utilisant cependant des mécanismes différents. De plus, nous avons détecté l’activation, par l’hôte, d’une réponse commune en réponse à une infection par PAK_P3 ou PAK_P4 et avons émis l’hypothèse qu’il s’agit d’une tentative de réparation des importants dommages ARN induits par l’infection virale. Enfin, nous avons étudié les fonctions d’une protéine virale (Gp92), largement conservée chez les virus appartenant à ces deux genres et qui est produite au stade précoce du cycle infectieux. Lorsqu’elle est produite seule chez l’hôte, cette protéine altère la morphologie cellulaire et interagit avec un complexe de régulation bactérien de type sigma/anti-sigma impliqué dans la réponse au stress (appelé AlgU-MucA). Notre étude suggère un rôle potentiel de Gp92 dans l’atténuation du stress provoqué par l’infection virale. Ce manuscrit fournit un modèle de transformation d’une cellule de P. aeruginosa en « virocellule » au cours de l’infection par PAK_P3 ou PAK_P4. De plus, la comparaison des stratégies de ces deux virus, vraisemblablement issus d’un ancêtre commun, nous a permis de discuter l’évolution des mécanismes infectieux chez les phages virulents / Previous investigations in the field of phage therapy led to the discovery of two new genera of bacteriophages (phages), namely Kpp10virus and Pakpunavirus whose infection mechanisms are unknown. It is acknowledged that a successful infection is notably ensured by an effective takeover of host cell resources, leading to its transformation into a virocell, a cellular organism exclusively dedicated to the production of progeny phages.This PhD work aims to provide a comprehensive view of molecular strategies set up by Kpp10virus and Pakpunavirus (represented by phages PAK_P3 and PAK_P4, respectively) to infect the opportunist pathogen Pseudomonas aeruginosa.First, we assessed phage intrinsic properties by analyzing their genomic content, evaluating their host range and growth parameters and identifying their bacterial receptor.Then, by coupling transcriptomics and metabolomics approaches, we found that both viruses have similar transcriptional programs, with a temporal regulation of their gene expression and production of antisense transcripts. They both strikingly prompt a rapid degradation of 90% of host mRNAs, which are eventually replaced by viral RNAs. Despite this extensive degradation, we found that both phages do not shutoff host metabolism but redirect biosynthesis pathways, however through different mechanisms. In addition, we found that a common host response is elicited upon both PAK_P3 and PAK_P4 infections and hypothesized it represents an attempt of the host to repair extensive RNA damage.Finally, we investigated the functions of an early produced phage protein (Gp92), broadly conserved in both phage genera, in order to identify particular mechanisms of host subversion used by these phages. When expressed alone in the host, Gp92 alters cell morphology and interacts with the bacterial regulatory complex sigma/anti-sigma involved in stress response (namely AlgU- MucA). Our study suggests a potential role of Gp92 in alleviating the stress caused by phage infection.This manuscript provides a model of virocell transformation upon infection of P. aeruginosa by PAK_P3 or PAK_P4. In addition, by comparing their reproductive strategies, it addresses the evolution of infection mechanisms in virulent phages deriving from a common ancestor
7

Características microbiológicas e clínicas das infecções por Acinetobacter spp. e Pseudomonas aeruginosa em Unidade de Terapia Intensiva Cardíaca de um Hospital Universitário do Rio de Janeiro / Caracteristics microbiologicals and clínicals infections for Acinetobacter sp and Pseudomonas aeruginosa in United Terapy Intensive Cardiac in the Hospital University of Rio de Janeiro

Caroline Zapater Lobo 25 April 2012 (has links)
As infecções em cirurgia cardíaca ainda apresentam um cenário importante nas infecções associadas à assistência a saúde (IAAS), favorecendo ao paciente à aquisição de infecções por micro-organimos multirreristentes. Este trabalho teve como objetivo avaliar o perfil de resistência a antimicrobianos, verificar a presença de genes que codificam as enzimas dos tipos oxacilinases e metalo-beta-lactamases e descrever as características demográficas e clínicas dos pacientes colonziados/infectados por Acinetobacter spp. e P.aeruginosa internados no Centro de Terapia Intensiva Cardíaca do HUPE no período de 2005 a 2010. A maioria das 46 amostras de Acinetobacter spp e das 35 de P.aeruginosa foram de origem respiratória seguido de sangue. A maioria das amostras de A. baumannii apresentou altos percentuais de resistência a: ceftazidina, cefepime, piperacilina-sulbactam, ciprofloxacin, ceftriaxona e CIM &#8805;32 &#956;g/mL para os carbapenêmicos. Uma amostra foi resistente a Polimixina B. O gene blaOXA-23 foi detectado em 65% das amostras e uma amostra apresentou o gene blaOXA-24. Não foram detectados os genes blaOXA-58-like e blaOXA-143. Para P. aeruginosa os percentuais de resistência para todos os antimicrobianos foram inferiores a 32%. Quatro amostras apresentaram resistência intermediária a polimixina B e nenhum gene de resistência foi detectado. Os prontuários dos pacientes foram analisados a fim de associar as características clínicas com os processos infecciosos identificados e seu desfecho clínico. Na análise por tipo de micro-organismo associado ao processo infeccioso à idade acima de 70 anos, DM e uso da ventilação mecânica por tempo prolongado foi maior no grupo dos pacientes que apresentaram infecção por P.aeruginosa. O IAM, a ICC em internações anteriores e suas complicações (choque cardiogênico e arritmia) tiveram impacto na mortalidade na série de pacientes (p<0,05). A insuficiência renal entre todas as comorbidades foi à única que teve associação com a mortalidade (OR= 8,3). Não houve associação entre a mortalidade e o micro-organismo que causou a infecção (Acinetobacter spp. p=0,3 e P.aeruginosa p=0,2) ou a resistência a carbapenêmicos (p=0,5). Foram observados dois casos de mediastinte por Acinetobacter spp. e dois por P. aeruginosa sendo um achado inédito no Brasil até o momento. / Infections in cardiac surgery still have an important scenario infections associated with health assistance(IAHA), favoring acquisition of the patients to infection by microrganisms multiresistants. This work aimed to avaluate the profile of the resistance antimicrobial, to verify the presence of genes encoding enzymes of types oxacilinases and metallo-beta-lactamases and describe demographic and clinical caracteristics of inpatients colonized/infected by Acinetobacter spp. and P. aeruginosa in Cardiac Care Center the Pedro Ernesto University Hospital during the period 2005 to 2010. Most of 46 samples of Acinetobacter spp. and 35 the P. aeruginosa were the respiratory origen and and blood. Most sample A.baumannii showed higher percentages of resistance to: ceftazidime, piperacilin-sulbactam, ciprofloxacin, ceftriaxone and CIM &#8805;32 &#956;g/mL for carbapenems. A sample was resistant a polymyxin B. The gene blaOXA-23 was detected in 65% of the samples and a sample showed gene blaOXA-24.The genes blaOXA-58-like e blaOXA-143 not were detected. For P. aeruginosa the percentage of resistance to all antimicrobials was less than 32%. Four samples showed intermediate resistance to polymyxin B and no gene the resistance was detected.The charts of all patients were analyzed in order to associated the clinical caracteristics with infections processes identified and the clinical outcome. The analyses by type of microrganism associated with infections process over the age of 70 years, DM and use mechanical ventilation for prolonged was higer in the patients with infection by P. aeruginosa. The IAM and the ICC of previous hospitalizations and complications (cardiogenic shock and arrhythmia) had an impact on mortality in series of patients (p<0,05). The renal failure among all comorbitidies was the only one that was associated with mortality (OR=8,3). There was no association between mortality and the organism causing the infection (Acinetobacter spp. p=0,3 and P.aeruginosa p=0,2). Two cases of mediastinitis of Acinetobacter spp. and two cases of P. aeruginosa was observed. It was an umprecedented finding in Brazil at that moment.
8

Características microbiológicas e clínicas das infecções por Acinetobacter spp. e Pseudomonas aeruginosa em Unidade de Terapia Intensiva Cardíaca de um Hospital Universitário do Rio de Janeiro / Caracteristics microbiologicals and clínicals infections for Acinetobacter sp and Pseudomonas aeruginosa in United Terapy Intensive Cardiac in the Hospital University of Rio de Janeiro

Caroline Zapater Lobo 25 April 2012 (has links)
As infecções em cirurgia cardíaca ainda apresentam um cenário importante nas infecções associadas à assistência a saúde (IAAS), favorecendo ao paciente à aquisição de infecções por micro-organimos multirreristentes. Este trabalho teve como objetivo avaliar o perfil de resistência a antimicrobianos, verificar a presença de genes que codificam as enzimas dos tipos oxacilinases e metalo-beta-lactamases e descrever as características demográficas e clínicas dos pacientes colonziados/infectados por Acinetobacter spp. e P.aeruginosa internados no Centro de Terapia Intensiva Cardíaca do HUPE no período de 2005 a 2010. A maioria das 46 amostras de Acinetobacter spp e das 35 de P.aeruginosa foram de origem respiratória seguido de sangue. A maioria das amostras de A. baumannii apresentou altos percentuais de resistência a: ceftazidina, cefepime, piperacilina-sulbactam, ciprofloxacin, ceftriaxona e CIM &#8805;32 &#956;g/mL para os carbapenêmicos. Uma amostra foi resistente a Polimixina B. O gene blaOXA-23 foi detectado em 65% das amostras e uma amostra apresentou o gene blaOXA-24. Não foram detectados os genes blaOXA-58-like e blaOXA-143. Para P. aeruginosa os percentuais de resistência para todos os antimicrobianos foram inferiores a 32%. Quatro amostras apresentaram resistência intermediária a polimixina B e nenhum gene de resistência foi detectado. Os prontuários dos pacientes foram analisados a fim de associar as características clínicas com os processos infecciosos identificados e seu desfecho clínico. Na análise por tipo de micro-organismo associado ao processo infeccioso à idade acima de 70 anos, DM e uso da ventilação mecânica por tempo prolongado foi maior no grupo dos pacientes que apresentaram infecção por P.aeruginosa. O IAM, a ICC em internações anteriores e suas complicações (choque cardiogênico e arritmia) tiveram impacto na mortalidade na série de pacientes (p<0,05). A insuficiência renal entre todas as comorbidades foi à única que teve associação com a mortalidade (OR= 8,3). Não houve associação entre a mortalidade e o micro-organismo que causou a infecção (Acinetobacter spp. p=0,3 e P.aeruginosa p=0,2) ou a resistência a carbapenêmicos (p=0,5). Foram observados dois casos de mediastinte por Acinetobacter spp. e dois por P. aeruginosa sendo um achado inédito no Brasil até o momento. / Infections in cardiac surgery still have an important scenario infections associated with health assistance(IAHA), favoring acquisition of the patients to infection by microrganisms multiresistants. This work aimed to avaluate the profile of the resistance antimicrobial, to verify the presence of genes encoding enzymes of types oxacilinases and metallo-beta-lactamases and describe demographic and clinical caracteristics of inpatients colonized/infected by Acinetobacter spp. and P. aeruginosa in Cardiac Care Center the Pedro Ernesto University Hospital during the period 2005 to 2010. Most of 46 samples of Acinetobacter spp. and 35 the P. aeruginosa were the respiratory origen and and blood. Most sample A.baumannii showed higher percentages of resistance to: ceftazidime, piperacilin-sulbactam, ciprofloxacin, ceftriaxone and CIM &#8805;32 &#956;g/mL for carbapenems. A sample was resistant a polymyxin B. The gene blaOXA-23 was detected in 65% of the samples and a sample showed gene blaOXA-24.The genes blaOXA-58-like e blaOXA-143 not were detected. For P. aeruginosa the percentage of resistance to all antimicrobials was less than 32%. Four samples showed intermediate resistance to polymyxin B and no gene the resistance was detected.The charts of all patients were analyzed in order to associated the clinical caracteristics with infections processes identified and the clinical outcome. The analyses by type of microrganism associated with infections process over the age of 70 years, DM and use mechanical ventilation for prolonged was higer in the patients with infection by P. aeruginosa. The IAM and the ICC of previous hospitalizations and complications (cardiogenic shock and arrhythmia) had an impact on mortality in series of patients (p<0,05). The renal failure among all comorbitidies was the only one that was associated with mortality (OR=8,3). There was no association between mortality and the organism causing the infection (Acinetobacter spp. p=0,3 and P.aeruginosa p=0,2). Two cases of mediastinitis of Acinetobacter spp. and two cases of P. aeruginosa was observed. It was an umprecedented finding in Brazil at that moment.
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Exploitation du potentiel des bactériophages dans le traitement des surfaces en contact avec l'eau, contaminées par un biofilm de P. aeruginosa / Exploration of the potential of bacteriophages in the treatment of surfaces in contact with water, contaminated by a biofilm of Pseudonomas aeruginosa

Magin, Vanessa 06 September 2019 (has links)
P. aeruginosa fait partie des bactéries classées comme multirésistantes. Ce bacille est un agent pathogène opportuniste susceptible d’être présent dans les réseaux d’eau. Les contaminations sont souvent localisées au niveau des points d’usage et sont à l’origine de risques sanitaires et économiques pour les établissements de santé et les industries. Bien que différents procédés de traitements soient couramment appliqués certaines contaminations persistent sous la forme de biofilm et altèrent la qualité de l’EDCH, tout en devenant un potentiel réservoir de dissémination. L’absence de traitements efficaces et l’impact négatif des biocides sur l’environnement sont en faveur du développement de nouvelles alternatives. Les bactériophages sont exclusivement des virus de bactéries. Ces prédateurs naturels sont omniprésents dans l'environnement, ce qui nous permet de disposer d'une grande diversité et ont l’avantage des’auto-répliquer en présence de leur hôte. Dans ce contexte, cette étude évalue le potentiel de ces virus en tant qu'agents de biocontrôle pour éliminer les biofilms de P. aeruginosa. Neuf souches de P. aeruginosa, incluant la souche référence PAO1 et des souches environnementales, ont été utilisées pour étudier l'activité de neuf phages appartenant à la famille des Caudovirales. Un screening a été réalisé permettant par la méthode des spots test de sélectionner les phages les plus efficaces et les souches sensibles. Les bactéries ont ensuite été cultivées dans un milieu mineral minimum et l'efficacité des phages a été étudiée sur une culture exponentielle. Le suivi de la densité optique a permis de mettre évidence trois profils d’activités différents. Sur la base de ces résultats, deux phages et deux souches ont été conservés pour réaliser des tests sur des biofilms de 24 h implantés à la surface de coupons en INOX, représentatif des surfaces industrielles ou thermales. L’efficacité du traitement par les phages durant 14 h a été évaluée par qPCR viable. Une réduction maximale de 1,7 équivalent Log UFC.cm2 /coupon a été obtenu selon le couple étudié. Les résultats mettent également en avant une répartition des phages en faveur des cellules planctoniques, contrôlant ainsi efficacement la dissémination du biofilm dans l’environnement. Cette étude met en évidence une action des phages qui est dépendante de la souche de P. aeruginosa ainsi que de l'état physiologiques des cellules (planctoniques ou sessiles) ce qui rend difficile l’élimination d’un biofilm, même jeune. Dans le but d’améliorer l’infection de ces structures il pourrait être envisagé d'associer l'activité de plusieurs phages dans un cocktail ou de les combiner à d'autres molécules d’intérêts. / P. aeruginosa is one of the bacteria classified as multiresistant. This bacillus is an opportunistic pathogen that may be present in water networks. Contaminations are often located at the point of use and are at the origin of health and economic issues for health facilities and industries. Although different treatment processes are commonly applied, certain contaminations persist in the form of biofilm, alter the quality of EDCH and represent a reservoir of dissemination. The lack of effective treatments and the negative impact of biocides on the environment favor the development of new alternatives. Bacteriophages are exclusively bacterial viruses. These natural predators are ubiquitous in the environment, which allows us to have a great diversity, and have the advantage of self replicationin the presence of their host. In this context, this work explores the potential of these viruses as biocontrol agents to eliminate P. aeruginosa biofilms in addition to existing solutions. Nine strains of P. aeruginosa, including PAO1 reference strain and environmental strains were used to study the activity of nine phages belonging to the family Caudovirales. A screening was carried out allowing by the spottest method to select the most effective phages and sensitives trains. A screening was carried out allowing by the spot test method to select the most effective phages and sensitive strains. Bacteria were then cultivated in a mineral minimum medium and the efficiency of the phages was studied on an exponential culture phase. Monitoring of optical density has enabled to highlight three different activity profiles. On the basis of these results, two phages and two strains were kept for testing on 24-hour biofilms implanted on the surface of stainless steel coupons, representative of industrial or thermal surfaces. The efficacy of phage treatment for 14 h was evaluated by viable qPCR. A maximum reduction of 1.7 log equivalent UFC.cm2 / coupon was obtained according to the couple studied. The results also highlight a phage distribution in favor of planktonic cells, effectively controlling the release of biofilm into the environment. This study demonstrates a phage action that is dependent on the P. aeruginosa strain as well as the physiological state of the cells (planktonic or sessile). The complexity of the biofilms’ structure makes it difficult to eliminate them, even when young. In order to improve the infection of these structures it could be considered to associate the activity of several phages in a cocktail or to combine them with other molecules of interest.
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Επιδημιολογική διερεύνηση κλινικών στελεχών P. aeruginosa από νοσοκομειακούς ασθενείς

Κουτσογιάννου, Μαρία 11 October 2013 (has links)
Κατά τη χρονική περίοδο 2006-2007 απομονώθηκαν συνολικά 952 στελέχη P. aeruginosa στο Μικροβιολογικό Εργαστήριο του ΠΓΝΠ. Επιλέχθηκαν για μελέτη 240 στελέχη, τα πρώτα δέκα από κάθε μήνα και ένα στέλεχος από κάθε ασθενή. Τα στελέχη απομονώθηκαν μετά από καλλιέργεια κλινικών δειγμάτων: τραυμάτων-υγρών, κεντρικών φλεβικών καθετήρων, αναπνευστικού συστήματος, ούρων, κοπράνων και αίματος. Τα κλινικά δείγματα προέρχονταν από ασθενείς που νοσηλεύονταν στη ΜΕΘ, τις Παθολογικές Κλινικές, τις Χειρουργικές Κλινικές, την Παιδιατρική Κλινική και προσέρχονταν στα Εξωτερικά Ιατρεία του ΠΓΝΠ. Φαινοτυπικές και μοριακές μεθόδοι χρησιμοποιήθηκαν για την επιδημιολογική διερεύνηση των στελεχών. Ανιχνεύθηκε ο βιότυπος, έγινε έλεγχος της ευαισθησίας στα αντιβιοτικά, έλεγχος της παραγωγής MBLs και ορολογική τυποποίηση των στελεχών. Οι μοριακές μέθοδοι περιλάμβαναν την ανίχνευση των γονιδίων blaVIM, exoY, exoT, exoS και exoU με PCR, τυποποίηση του γονιδίου blaVIM με ανάλυση της αλληλουχίας και εφαρμογή των μεθόδων PFGE (SpeI) και MLST ταυτοποίηση κλώνων. Τα περισσότερα στελέχη εμπλέκονταν σε λοιμώξεις (65,42%). Τα περισσότερα δείγματα προήλθαν από τη ΜΕΘ (92/240, 38%), σημαντικό ποσοστό των οποίων αφορούσε τη χλωρίδα των ασθενών (56/92, 61%). Τα περισσότερα στελέχη ήταν MDRPA (63,33%) και άνηκαν στον ορότυπο Ο11 (49,16%). Το 33% των ιμιπενέμη ανθεκτικών στελεχών ήταν blaVIM θετικά (κυρίως blaVIM2, και blaVIM1). Με την PFGE τα στελέχη διακρίθηκαν σε 5 κύριους τύπους a, d, b, c και s, με επικρατούντες τους a (33,75%) και d (13,75%). Με την MLST τα στελέχη διακρίθηκαν κυρίως στους δύο παγκόσμιους κλώνους ST235 (PFGE τύποι a, d και b) και ST111 (PFGE τύπος b). Η παρούσα μελέτη αναδεικνύει μία επιδημική έξαρση από MDRPA στο ΠΓΝΠ. Τα MDRPA ανήκαν κυρίως στους PFGE τύπους a και d του ορότυπου Ο11 και κλώνου ST235, με γονοτυπικό προφίλ exoU +/exoS - που επικρατούσαν στη ΜΕΘ. Η παρατήρηση ότι τα περισσότερα στελέχη που απομονώθηκαν από δείγματα αποικισμού των ασθενών (49/83) ανήκαν στον κλώνο ST235 υποδεικνύει ότι ο αποικισμός των ασθενών της ΜΕΘ συμβάλλει στη λοίμωξη από στελέχη P. aeruginosa και στη διασπορά τους στις άλλες κλινικές του νοσοκομείου. Το γεγονός ότι τα περισσότερα των στελεχών (18/33) του PFGE τύπου d (ST235) φέρουν το γονίδιο blaVIM2 ενισχύει την άποψη ότι η κλωνική διασπορά διαδραμάτισε ρόλο στην επιδημική έξαρση από ιμιπενέμη-ανθεκτικά στελέχη P. aeruginosa. / During the period 2006-2007 a total of 952 P. aeruginosa strains were isolated in the Microbiology Laboratory of the University Hospital of Patras. Two hundred and forty, the first ten from every month no replicate isolates (one isolate per patient), were selected to be studied further. The strains were isolated after inoculation of clinical specimens: wound-liquids, intravenous catheters, respiratory samples, urine, stool and blood. P. aeruginosa was identified by standard phenotypic methods. The clinical samples were collected from patients hospitalized in the ICU, Internal Medicine, Surgical Units, Pediatric Unit and the Department of Outpatients. Phenotypic and molecular methods were applied for the epidemiological study. Phenotypic methods were: antibiotic susceptibility testing, metallo-beta-lactamases (MBL) production and serotyping. The molecular methods included detection of genes blaVIM, exoY, exoT, exoS, exoU by PCR, blaVIM gene sequencing, PFGE (SpeI) and MLST. The majority of isolates were infection-related (65,42%). Most of them were recovered from ICU patients (92/240, 38%), 61% (56/92) of which were colonizing isolates. Most strains were MDRPA (63,33%) and belonged to serotype O11 (49,16%). Thirty three percent (33%) of imipenem non-susceptible isolates were blaVIM positive (specifically blaVIM2, and blaVIM1). PFGE exhibited five main types: a, d, b, c and s [predominant a (33,75%), d (13,75%)]. By MLST, the strains were classified mainly in the two international clones ST235 (PFGE types a, d and b), and ST111 (PFGE type b). The present study revealed an outbreak of MDRPA in the University Hospital of Patras. MDRPA belonged mainly to PFGE types a and d of serotype O11 and clone ST235, showing the profile exoU +/exoS -, and predominaded in ICU. The observation that most colonizing isolates (49/83) belonged to ST235 indicates that colonization during ICU hospitalization contributes to infection and spread of MDRPA to other wards. The fact that the majority (18/33) of PFGE type d strains (ST235) carry blaVIM2 gene, reinforces that clonal spread may have played a role in the outbreak of imipenem non-susceptible P. aeruginosa strains.

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