Made available in DSpace on 2015-04-14T13:35:27Z (GMT). No. of bitstreams: 1 437323.pdf: 4287591 bytes, checksum: a4736ecf5ed6c11a9d86f23c3c30d3b3 (MD5) Previous issue date: 2012-01-18 / Tuberculosis re-emerged in the mid 80s and currently about two million people die each year due to this disease. The resurgence of tuberculosis has become a threat to public health. The high susceptibility of HIV-infected patients and the proliferation of multi-drug resistant strains have created the need to develop new therapies. However, no new class of drugs against tuberculosis was developed in the last 45 years. Thus, it becomes imminent need to develop new antituberculosis agents. As purine metabolism could be implicated in mycobacterial latency the purine nucleoside phosphorylase (EC 2.4.2.1) has been proposed as target for development of antibacterial drugs. PNP catalyzes the reversible cleavage in the presence of inorganic phosphate of N-ribosidic bonds of the purine nucleosides and deoxynucleosides, except adenosine. This reaction generates the purine base and ribose (deoxyribose)-1-phosphate. PNP is specific for purine nucleosides in the β-configuration and cleaves the glycosidic bond with inversion of configuration to produce α-ribose-1-phosphate. In this work PNP was crystallized in association with inosine, hypoxanthine and acyclovir, substrate, product and inhibitor, respectively, and data were collected using synchrotron radiation. In addition, molecular dynamics simulations and isothermal titration calorimetry experiments were used to provide detailed information on the dynamic properties and to investigate the profile and thermodynamic affinities of MtPNP associated with these molecules. With obtained results we hope to contribute to the search of new selective inhibitors for MtPNP, since differences between the mycobacterial and human enzyme binding sites have been also identified, making structure-based drug design feasible. / A tuberculose ressurgiu na metade dos anos 80 e, atualmente aproximadamente dois milh?es de pessoas morrem por ano devido a esta doen?a. O ressurgimento da tuberculose tornou-se uma amea?a ? sa?de p?blica. A alta susceptibilidade dos pacientes infectados com HIV e a prolifera??o de cepas resistentes a m?ltiplas drogas t?m criado a necessidade de se desenvolver novas terapias. No entanto, nenhuma nova classe de drogas contra a tuberculose foi desenvolvida nos ?ltimos 45 anos. Deste modo, torna-se iminente a necessidade de se desenvolver novos agentes antituberculose. Como o metabolismo de purinas pode estar implicado na lat?ncia da micobact?ria, a purina nucleos?deo fosforilase de Mycobacterium tuberculosis (MtPNP) (EC 2.4.2.1) foi proposta como alvo para o desenvolvimento de drogas antibacterianas. A PNP catalisa a clivagem revers?vel, na presen?a de fosfato inorg?nico, de liga??es N-ribos?dicas de nucleos?deos e desoxinucleos?deos de purina, com exce??o da adenosina. Esta rea??o produz base p?rica livre e ribose (desoxiribose)-1-fosfato. A rea??o se processa com invers?o de configura??o, de β-nucleos?deos para α-ribose-1-fosfato. Neste trabalho a PNP foi cristalizada em associa??o com inosina, hipoxantina e aciclovir, substrato, produto e inibidor, respectivamente, e os dados foram coletados utilizando radia??o s?ncrotron. Al?m disso, a simula??o por din?mica molecular e experimentos de calorimetria por titula??o isot?rmica foram utilizadas para fornecer informa??es detalhadas acerca das propriedades din?micas, e investigar o perfil termodin?mico e afinidades da MtPNP associada com estas mol?culas. Com os resultados obtidos n?s esperamos contribuir para a busca de novos inibidores seletivos de MtPNP, j? que as diferen?as entre os s?tios de liga??o da enzima humana e de micobact?ria foram identificadas , tornando vi?veis projetos de desenho de drogas baseados na estrutura.

Submitted by Setor de Tratamento da Informa??o - BC/PUCRS (tede2@pucrs.br) on 2016-05-19T12:54:32Z No. of bitstreams: 1 DIS_ROBERTA_MONTEIRO_KATZAP_COMPLETO.pdf: 1440611 bytes, checksum: 60581bcd966d13bb2ed8592af3528373 (MD5) / Made available in DSpace on 2016-05-19T12:54:32Z (GMT). No. of bitstreams: 1 DIS_ROBERTA_MONTEIRO_KATZAP_COMPLETO.pdf: 1440611 bytes, checksum: 60581bcd966d13bb2ed8592af3528373 (MD5) Previous issue date: 2016-03-02 / Funda??o de Amparo ? Pesquisa do Estado do Rio Grande do Sul - FAPERGS / Chronic kidney disease patients on peritoneal dialysis therapy are susceptible to infections, with peritonitis being the primary cause of technique failure. Peritoneal fluid culture is one of the essential elements for proper diagnosis and treatment of peritonitis. The aim of this study was to compare the time required to obtain a positive culture using different laboratory methods. An in vitro cross-sectional study comparing different laboratory techniques for preparation and culture of bacteria in peritoneal fluid. The research was conducted with 21 sterile dialysis fluid bags with 1.5% glucose concentration, and 21 peritoneal dialysis bags containing peritoneal fluid drained from patients without peritonitis, assisted at the Nephrology Unit from HSL-PUCRS. Fluids from the 42 peritoneal dialysis bags were contaminated by injecting a coagulase-negative Staphylococcus suspension and then prepared for culture using four distinct techniques - A (direct culture), B (post-centrifugation culture), C (direct culture after 4h sedimentation), and D (culture after 4h sedimentation and centrifugation) ? followed by seeding. In the 21 contaminated sterile bags, the mean times to obtain a positive culture with techniques D (19.6 h ?2.6) and C (19.1 h ?2.3) were longer in comparison to A (15.8 h ?3.0; p<0.01), but not statistically different from group B mean (19.0 h ?3.2). The same occurred in the 21 bags drained from patients, with mean times for techniques D (14.0 h ?1.9) and C (14.5 h ?1.7) being longer than technique A (12.22 h ?1.94; p<0.05), however not statistically different from technique B (13.2 h ?1.3). The sedimentation and centrifugation steps were unnecessary and may delay antibiotics sensitivity test result by approximately 8 hours. / Pacientes com doen?a renal cr?nica que realizam terapia de di?lise peritoneal est?o suscet?veis a infec??es, sendo peritonite a principal causa de fal?ncia do m?todo. A cultura do l?quido peritoneal ? um dos elementos essenciais para o manejo cl?nico e tratamento adequados da peritonite. O objetivo deste estudo foi comparar o tempo necess?rio para obter uma cultura positiva, com diferentes m?todos laboratoriais. Estudo transversal, in vitro, comparando diferentes t?cnicas laboratoriais de preparo e cultura para bact?rias em l?quido peritoneal. O estudo foi feito com 21 bolsas de l?quido de di?lise peritoneal est?reis, com concentra??o de 1,5% de glicose, e em 21 bolsas contendo l?quido peritoneal drenado de pacientes sem peritonite, atendidos pelo Servi?o de Nefrologia do HSL-PUCRS. O dialisado das 42 bolsas de di?lise peritoneal foi contaminado, injetando-se suspens?o de Staphylococcus coagulase negativa e, em seguida, submetido a quatro t?cnicas distintas ? A (cultura direta); B (cultura p?s-centrifuga??o); C (cultura ap?s sedimenta??o de 4 h); e D (cultura ap?s sedimenta??o de 4 h e centrifuga??o) ? de preparo e semeadura. Nas 21 bolsas est?reis contaminadas se verificou que as m?dias de tempo para positivar a cultura nas t?cnicas D (19,6 h ?2,6) e C (19,1 h ?2,3) foram maiores, comparadas ? A (15,8 h ?3,0; p<0,01), mas estatisticamente n?o diferentes da m?dia do grupo B (19,0 h ?3,2). O mesmo aconteceu nas 21 bolsas drenadas dos pacientes, com tempos m?dios para as t?cnicas D (14,0 h ?1,9) e C (14,5 h ?1,7) superiores ao tempo da t?cnica A (12,22 h ?1,94; p<0,05), por?m n?o estatisticamente diferente da t?cnica B (13,2 h ?1,3). As etapas de sedimenta??o e centrifuga??o foram desnecess?rias, podendo postergar em quase oito horas o resultado final da cultura, comparativamente ? cultura direta, atrasando o resultado do teste de sensibilidade aos antibi?ticos.

Made available in DSpace on 2016-04-28T20:17:29Z (GMT). No. of bitstreams: 1 2008 - Marcelo Santos de Oliva.pdf: 3554572 bytes, checksum: 0fae31785d5eaf0f107b4791b1e03628 (MD5) Previous issue date: 2008-11-13 / Mussels are bivalve mollusks that developed a filtrating system enabling them to uptake nutrients from water. This is a not selective mechanism, so mussels microbiological analysis shows up the aquatic environment quality. Therefore, the present work aimed to isolate and identify bacterial microbiota from bivalve mollusks incrustated into the rocky coast of Arquip?lago de Santana, Maca?, RJ. The antimicrobial resistance pattern of prevalent microorganisms isolated was also analyzed. The surrounding water microbiological quality was also evaluated in order to detect contamination source from fishing and subaquatic activities in the studied region. From the bacteriological analysis it was obtained a total of 51 isolates of Vibrio spp., being V. damsela (n=15) the prevalent specie, followed by V. harveyi (n=13) and V. alginolyticus (n=07). It was also obtained a total of 20 isolates of Enterobacteriaceae species, being Escherichia coli (n=06) the prevalent one, followed by Proteus vulgaris (n=04). Vibrio spp. isolates presented 100% of sensitivity to tested antimicrobials, except for ampicillin with no detected sensitivity corroborating to literature. For enterobacteria, it was detected a high percentile of sensitivity to all testes antimicrobials. In the six samples of ocean water analyzed it was not possible to detect total or fecal coliforms. The low percentile of isolated microorganisms from mussels at Arquip?lago de Santana can be justified for its location at the open sea, far away from the coast and influenced by sea currents, in a environment not yet altered by human action. / Os mexilh?es s?o moluscos bivalves filtradores que se alimentam de microrganismos captados pela corrente de ?gua e n?o apresentam capacidade seletiva de filtra??o do seu alimento, consequentemente, a an?lise dos mexilh?es reflete a qualidade microbiol?gica do habitat aqu?tico. Desse modo, o presente trabalho objetivou executar o isolamento e identifica??o da microbiota bacteriana a partir de moluscos bivalves incrustados em cost?es rochosos no Arquip?lago de Santana, Maca?- RJ, bem como analisar o perfil de resist?ncia dos microrganismos prevalentes. Tamb?m se buscou avaliar a qualidade da ?gua de modo a detectar poss?veis contamina??es decorrentes das atividades pesqueiras e subaqu?ticas nesta regi?o. A partir das an?lises bacteriol?gicas foi obtido um total de 51 col?nias de Vibrio spp. com preval?ncia da esp?cie V. damsela (n=15), seguida de V. harveyi (n=13) e V. alginolyticus (n=07) e um total de 20 col?nias de enterobact?rias com preval?ncia de Escherichia coli (n=06) seguida de Proteus vulgaris (n=04). Os isolados de Vibrio spp. apresentaram 100% de sensibilidade aos antimicrobianos testados, com exce??o da ampicilina, para a qual n?o foi detectada qualquer sensibilidade a semelhan?a de outros relatos na literatura. Nos isolados de enterobact?rias avaliados, foram detectados elevados percentuais de sensibilidade aos antimicrobianos testados. No total de seis amostras de ?gua do mar analisadas, n?o foi detectada a presen?a de coliformes totais e termotolerantes. O baixo percentual de microrganismos isolados de mexilh?es no Arquip?lago de Santana pode ser justificado por ser um local de mar aberto, afastado da costa e sobre a influ?ncia de correntes mar?timas, e ainda pouco impactado pela a??o humana.

Made available in DSpace on 2015-04-14T14:51:26Z (GMT). No. of bitstreams: 1 449081.pdf: 619736 bytes, checksum: f49f3ff20314e610e563f984cfead299 (MD5) Previous issue date: 2013-04-30 / Salmonella Enteritidis is the most prevalent serotype isolated in Brazil, mainly associated with poultry products, which have been primarily involved in foodborne disease outbreaks. The high prevalence of reduced susceptibility to antimicrobial agents in various Salmonella serotypes isolated from samples related to livestock animal, animal foods and human has been reported worldwide. Therefore, has increased the interest in investigating the genetic mechanisms involved in resistance to antimicrobial agents, especially genetic elements capable of carrying resistance genes cassettes, which could be the origin of multi-resistant strains. Besides the genetically determined antimicrobial resistance, bacteria can also exhibit resistance by the ability to form biofilm, which protects bacteria from environmental stresses, favoring the colonization and persistence of these microorganisms in the environment. Thus, the aim of this study was to determine the antimicrobial susceptibility of S. Enteritidis strains and investigate the genes involved in the main resistance determined, as well as evaluate the ability of these strains in to produce biofilm. Forty-seven S. Enteritidis strains isolated from human, poultry, swine, and food were analyzed. Sixteen isolates (34%) were phenotypically resistant to at least one antibiotic tested. Of these, four isolates harbored class 1 integron. All strains resistant to sulfonamide had concomitantly genes sul1 and sul2. The genes strA, strB, aadA and aadB were identified in the majority of the aminoglycosides resistant isolates, whereas 92.9% showed strA, 71.4% strB, 7.1% aadA and 50% aadB. The tetB gene was detected in two of the three strains resistant to tetracycline, and tetC in one. In the three strains resistant to ampicillin the blaTEM gene was detected. Overall, among the 47 S. Enteritidis tested, 89.4% strains were able to form biofilm on polystyrene plates. Among these, 42.4% were considered weak biofilm producers, 14.9% moderate producers and 34% strong producers. It has been demonstrated that the majority of the S. Enteritidis strains that showed resistance to at least one antimicrobial agent were able to form biofilm, which increases concerns about food contamination, especially by the possibility of persistence of bacteria resistant to antibiotics on the environment and the subsequently dissemination of these strains to human. / A Salmonella Enteritidis tem sido o sorotipo mais prevalente no Brasil, principalmente associado a produtos de origem av?cola, que t?m sido prioritariamente envolvidos em surtos de doen?as transmitidas por alimentos. A alta preval?ncia de suscetibilidade reduzida a antimicrobianos em diversos sorotipos de Salmonella isolados de amostras relacionadas a animais de produ??o, a humanos e a alimentos de origem animal vem sendo relatada no mundo inteiro. Com isto, tem aumentado o interesse em investigar os mecanismos gen?ticos envolvidos na resist?ncia a antimicrobianos, especialmente elementos gen?ticos capazes de carrear cassetes de genes de resist?ncia, o que pode constituir a origem de cepas multi-resistentes. Al?m da resist?ncia a antimicrobianos determinada geneticamente, as bact?rias tamb?m podem apresentar resist?ncia pela habilidade de formar biofilme, protegendo-as de estresses ambientais, favorecendo a coloniza??o e persist?ncia desses microrganismos no ambiente. Deste modo, o objetivo deste estudo foi determinar a suscetibilidade a antimicrobianos de cepas de S. Enteritidis e investigar os genes envolvidos nas principais resist?ncias determinadas, bem como avaliar a capacidade de forma??o de biofilme destas cepas. Para tanto, foram analisadas 47 cepas de S. Enteritidis isoladas de humanos, aves, su?nos e alimentos. Dezesseis isolados (34%) se mostraram fenotipicamente resistentes a pelo menos um antimicrobiano testado. Destes, quatro apresentaram integron de classe 1. Todas as cepas resistentes ? sulfonamida apresentaram concomitantemente os genes sul1 e sul2. Os genes strA, strB, aadA e aadB foram identificados na maioria dos isolados que apresentaram resist?ncia a aminoglicos?deos, sendo que 92,9% apresentaram o gene strA, 71,4% strB, 7,1% aadA e 50% aadB. O gene tetB foi detectado em duas das tr?s cepas resistentes ? tetraciclina e o tetC em uma. J? as tr?s cepas resistentes ? ampicilina apresentaram o gene blaTEM. No total, dentre as 47 cepas de S. Enteritidis testadas, 89,4% foram capazes de formar biofilme em placas de poliestireno. Dentre estas, 42,4% foram consideradas fracas produtoras de biofilme, 14,9% produtoras moderadas e 34% fortes produtoras. Foi demonstrado que a maioria das cepas que mostraram resist?ncia a pelo menos um antimicrobiano foram capazes de formar biofilme, o que aumenta a preocupa??o a respeito da contamina??o de alimentos, especialmente pela possibilidade de persist?ncia de microrganismos resistentes a antimicrobianos no ambiente e a subsequente dissemina??o destas cepas para humanos.

Made available in DSpace on 2015-04-14T14:51:39Z (GMT). No. of bitstreams: 1 393359.pdf: 3706184 bytes, checksum: 69c5551b27d8ba08aadf9a5c582b8491 (MD5) Previous issue date: 2007-07-05 / A resist?ncia natural das plantas a doen?as ? baseada tanto em mecanismos pr?-formados quanto em mecanismos induzidos. Esse estudo pretendeu analisar os n?veis de compostos fen?licos, incluindo o grupo dos flavon?ides e as atividades das enzimas polifenoloxidases (PPOs) e peroxidases (POX) em Solanum tuberosum cv. ?gata, em resposta ?s inocula??es com as bact?rias fitopatog?nicas incompat?veis Xanthomonas axonopodis, Ralstonia solanacearum, e compat?veis Erwinia carotovora. A compatibilidade das bact?rias foi avaliada atrav?s da inocula??o de tub?rculos. Tub?rculos infiltrados com E. carotovora exibiram sinais de doen?a e com R. solanacearum e X. axonopodis n?o desenvolveram doen?a. As inocula??es nas folhas foram realizadas dependendo do n?mero e das localiza??es das folhas nos ramos. As inocula??es m?ltiplas foram realizadas nas folhas basais, intermedi?rias e apicais e as inocula??es simples ocorreram nas folhas intermedi?rias. As folhas inoculadas com as suspens?es de X. axonopodis e R. solanacearum exibiram a resposta de hipersensibilidade (HR) dentro de 24 hpi, enquanto que as folhas inoculadas com E. carotovora evidenciaram sintomas de doen?a. Portanto, o isolado de R. solanacearum utilizado nos experimentos n?o mostrou virul?ncia a esta cultivar de batata. Independentemente do tratamento bacteriano, as folhas basais apresentaram nas inocula??es m?ltiplas, as mais altas atividades das PPOs e das POX e os n?veis mais baixos de compostos fen?licos totais e de flavon?ides, quando comparadas com as folhas apicais. As folhas basais e as intermedi?rias inoculadas com R. solanacearum e com X. axonopodis mostraram um aumento nos n?veis de compostos fen?licos totais e de flavon?ides. Esses aumentos foram similares ou maiores que os n?veis observados nas folhas apicais n?o inoculadas. De um modo geral, as inocula??es m?ltiplas exibiram os maiores n?veis de compostos fen?licos totais e de flavon?ides, enquanto que as inocula??es simples apresentaram os maiores aumentos nas atividades das PPOs. Contudo, as atividades das POX n?o apresentaram diferen?as significativas entre as inocula??es m?ltiplas e simples. No presente estudo, o metabolismo de defesa nesta cultivar de batata foi estimulado pelas bact?rias incompat?veis, indicando a sua posterior utiliza??o como indutoras da defesa da planta contra o ataque subseq?ente de pat?genos compat?veis.

Submitted by Jorge Silva (jorgelmsilva@ufrrj.br) on 2017-08-23T18:13:31Z No. of bitstreams: 1 2015 - Jakson Leite.pdf: 1055808 bytes, checksum: fa105f74410a81a1f30e45ae5e911c9d (MD5) / Made available in DSpace on 2017-08-23T18:13:31Z (GMT). No. of bitstreams: 1 2015 - Jakson Leite.pdf: 1055808 bytes, checksum: fa105f74410a81a1f30e45ae5e911c9d (MD5) Previous issue date: 2015-02-27 / CAPES / Cowpea [Vigna unguiculata (L.) Walp] is an important crop in northeastern Brazil with strategic advantages for production in semi-arid region, such its drought tolerance and good performance in low fertility soils. In addition, the nitrogen (N) fixed in symbiosis with rhizobia eliminates the demand for N fertilizers, with economic, social and environmental benefits. Little is known about the genetic diversity of bacteria associated to cowpea nodules in Brazilian semi-arid. The aim of the study was to characterize the bacterial diversity of Brazilian semi-arid soils associated with nodules of different cowpea cultivars by dependent and independent bacterial cultivation strategy. Initially a collection of 86 bacteria cowpea nodules isolated from semiarid soils was genetically characterized by partial 16S rRNA gene sequencing and symbiotic genes nifH and nodC. The sequences were compared with the NCBI database to identify isolates and phylogenetic relationships were built. In another study, we applied the independent cultivation method to evaluate bacterial communities associated with the nodules of two cowpea cultivars (BRS and BRS Acau? Pujante), in Ultisol with no history of cowpea cultivation. Nodules (N) were collected 35 days after germination, and soil samples (BS) from 0-20 cm deeper. DNA was extracted for analysis of bacterial communities with 454 pyrosequencing of the 16S ribosomal gene rRNA. The analysis of the diversity of the bacterial collection of the nodules 54 of the 86 isolates were Bradyrhizobium. Other (32) belong to Rhizobium (13) and Microvirga (1), Alfaproteobact?ria class; Burkholderia (8), and Ralstonia (1), Betaproteobacteria class; Acinetobacter (1), Cronobacter (3), Enterobacter (1), and Pantoea (1), Gamaproteobact?ria; and Leifsonia (3), phylum Actinobacteria. As Bradyrhizobium predominated, analyzes were performed with the almost full 16S rRNA, nifH and nodC and isolates were distributed in 5 lines: 16S rRNA type I (44 isolates), type II (6), Type III (1), Type IV ( 2) and type IV (1). Phylogenetic analysis of the 16S rRNA gene grouped the Type I strain in the large group Bradyrhizobium japonicum and close to the type strain of Bradyrhizobium yuanmingense. The analyses of the nifH and nodC gene separated the isolates in 5 symbiotic lines (I, II, III, IV and IV) and were congruent among them, which supports the theory of monophyletic in origin symbiotic gene Bradyhrizobium. The symbiotic lineages I and II are nearby and correspond to all isolates with 16S rRNA type I, being the dominant group associated with nodules. The partial 16S rRNA gene sequencing of bacterial communities showed high diversity in the three environments (BS, RS and N). The communities associated with the nodes were significantly different (p> 0.01) from the surrounding nodules (LS and RS). Phyla Actinobacteria, Bacteriodetes, Proteobacteria were plentiful for BS and RS. In nodes, the Proteobacteria and Bacteriodetes phyla predominated, Gammaproteobacteria being (58.8%) and Alphaproteobacteria (37.4%) in the phylum Proteobacteria and dominant Flavobacteriia (84.8%) and Sphingobacteriia (10.9%) in the phylum Bacteriodetes. For gender, Chryseobacterium, Entreobacter and Bradyrhizobium dominate in all nodes samples where Chryseobacterium prevailed in BRS Acau? and Enterobacter in BRS Pujante. / O feij?o-caupi [Vigna unguiculata (L.) Walp] ? uma das principais culturas no Nordeste do Brasil com vantagens estrat?gicas para produ??o no semi?rido, como toler?ncia a seca e bom desempenho em solos de baixa fertilidade. Al?m disso, fixa N em simbiose com riz?bios eliminando a demanda de fertilizantes nitrogenados, com benef?cios econ?micos, sociais e ambientais. Pouco se sabe sobre a diversidade gen?tica de bact?rias associadas aos n?dulos de feij?o-caupi no semi?rido. O objetivo do estudo foi caracterizar a diversidade de bact?rias de solos do semi?rido brasileiro associadas aos n?dulos de diferentes cultivares de feij?o-caupi com arbordagem que depende e independe de cultivo das bact?rias. Inicialmente uma cole??o de 86 bact?rias de n?dulos de feij?o-caupi isoladas de solos do semi?rido foi caracterizada geneticamente pelo sequenciamento parcial do gene 16S rRNA e dos genes simbi?ticos nifH e nodC. As sequ?ncias foram comparadas com as do banco de dados do NCBI para identificar os isolados e as rela??es filogen?ticas dos mesmos com as de esp?cies conhecidas. Em outro estudo, aplicou-se o m?todo independente de cultivo para avaliar comunidades de bact?rias associadas aos n?dulos de dois cultivares de feij?o-caupi (BRS Pujante e BRS Acau?), em Argissolo Amarelo sem hist?rico de uso com a lavoura. Os n?dulos (N) foram coletados 35 dias ap?s a germina??o e a amostragem do solo (BS) de 0-20 cm. O DNA das amostras foi extra?do para an?lises das comunidades bacterianas com 454 pirosequenciamento do gene ribossomal 16S rRNA. Na an?lise da diversidade da cole??o de n?dulos 54 dos 86 dos isolados foram de Bradyrhizobium. Os demais (32) pertencem aos g?neros Rhizobium (13) e Microvirga (1), classe Alfaproteobact?ria; Burkholderia (8) e Ralstonia (1), classe Betaproteobact?ria; Acinetobacter (1), Cronobacter (3), Enterobacter (1) e Pantoea (1), Gamaproteobact?ria; e Leifsonia (3), filo Actinobact?ria. Como Bradyrhizobium predominou, foram feitas an?lises com os genes 16S rRNA, nifH e nodC e os isolados distribu?ram-se em 5 linhagens: 16S rRNA tipo I (44 isolados), tipo II (6), tipo III (1), tipo IV (2) e tipo IV (1). A an?lise filogen?tica do gene 16S rRNA agrupou a linhagem tipo I no grande grupo Bradyrhizobium japonicum e pr?ximo da estirpe tipo de Bradyrhizobium yuanmingense. A an?lise dos genes nifH e nodC separou os isolados em 5 linhagens simbi?ticas (I, II, III, IV e IV) e as ?rvores foram congruentes, o que suporta a teoria da origem monofil?tica de genes simbi?ticos em Bradyhrizobium. As linhagens simbi?ticas I e II s?o pr?ximas e correspondem a todos os isolados com 16S rRNA tipo I, sendo o grupo dominante associado aos nodulos. O sequenciamento parcial do gene 16S rRNA das comunidades bacterianas mostrou alta diversidade nos tr?s ambientes (BS, RS e N). As comunidades associadas aos n?dulos foram significativamente diferentes (p> 0,01) das que cercam os n?dulos (LS e RS). Os filos Actinobacteria, Bacteriodetes, Proteobacteria foram abundantes para BS e RS. Em n?dulos, os filos Proteobacteria e Bacteriodetes predominaram, sendo Gammaproteobacteria (58,8%) e Alphaproteobacteria (37,4%) dominantes no filo Proteobacteria e Flavobacteriia (84,8%) e Sphingobacteriia (10,9%) no filo Bacteriodetes. Para g?nero, Chryseobacterium, Entreobacter e Bradyrhizobium dominam em todas as amostras de n?dulos, onde Chryseobacterium predominou em BRS Acau? e Enterobacter em BRS Pujante.

Submitted by Jorge Silva (jorgelmsilva@ufrrj.br) on 2018-05-18T17:44:09Z No. of bitstreams: 1 2014 - Dayana da Silva Correia.pdf: 2038600 bytes, checksum: 031920d278558b902310d93f752920d7 (MD5) / Made available in DSpace on 2018-05-18T17:44:09Z (GMT). No. of bitstreams: 1 2014 - Dayana da Silva Correia.pdf: 2038600 bytes, checksum: 031920d278558b902310d93f752920d7 (MD5) Previous issue date: 2014-03-26 / CAPES / CNPq / The symbiosis between soil invertebrates and micro"organisms is a major ally in promoting the decomposition of plant residues in the soil. The micro"organisms in turn, have an immense genetic diversity and play crucial roles in maintaining ecosystems. One of these functions is the production of extracellular enzymes that assist the mineralization of organic matter. The possibility of developing new biotechnological processes based on the exploration of microbial diversity is immense, due to the great variability that exists between biological systems and it can be optimized to improve the agricultural production systems in a sustainable manner. The objective of this work was to study the profile of the bacterial community and cellulolytic potential of bacteria isolated from three different species of invertebrates saprophages. The experiments were performed at the Experimental Station of Embrapa Agrobiology, Serop?dica, Rio de Janeiro State. Millipede, of the Trigoniulus corallinus species, were collected in piles of plant compounds from local experimental field sites, which were subsequently incubated for 60 days under six different diets. Bacterial diversity in the intestinal tract of invertebrates was analyzed by PCR"DGGE of 16S rDNA gene amplification by PCR electrophoresis in denaturing gradient gel (DGGE); two domains were used, Bacteria and Actinobacteria. Some bands of the DGGE gel were extracted and sequenced. To assess the potential for production of cellulases in response to the presence of carboxy methyl cellulose (CMC) of isolates, the technique Congo red stain was used and the values were expressed as means (Ie) enzymatic index. From the highest values of (Ie) twenty" three bacteria were selected for the analysis of 16S rDNA. After the phylogenetic identification, the cellulolytic potential was rated, through cellulolytic activity of endoglucanase (CMCase), and endo" and exoglucanases (FPase) tests. To determine the molecular weight and activity of the enzymes polyacrylamide gels (SDS"PAGE) and zymography were performed. The results obtained in the technique of DGGE, the profiles of DGGE bands, showed that the intestinal microbiota of the invertebrates has distinct bacterial groups. It is possible to infer that, despite the communities having similar abundance, such as in the Trigoniulus corallinus and Cubaris murine species, the groups that make up this abundance were different among the invertebrate?s species. From the clones of the incised bands, three phyla members, Proteobacteria, Firmicutes and Bacteroidetes, were sequenced. Through phylogenetic analysis, it was possible to identify the 23 species of bacteria. Presenting two distinct Actinomycetes and Firmicutes phylum, the largest genus identified was Streptomyces, followed by an isolated Bacillus, Paenibacillus, and Staphylococcus. The intestinal tract of the three species of saprophages invertebrates showed to be an adequate environment for prospection of bacteria with cellulolytic efficiency, with high potential for future biotechnological studies. / A simbiose entre invertebrados do solo e microrganismos ? um grande aliado no auxilio da decomposi??o de res?duos vegetais presentes no solo. Os microrganismos por sua vez, apresentam uma imensa diversidade gen?tica e desempenham fun??es cruciais na manuten??o dos ecossistemas, uma dessas fun??es ? a produ??o de enzimas extracelulares que auxiliam na mineraliza??o da mat?ria org?nica. A possibilidade de desenvolver novos processos biotecnol?gicos com base na prospec??o da diversidade microbiana ? imensa, em decorr?ncia da grande variabilidade que existe entre os sistemas biol?gicos e que podem ser aperfei?oados para melhorar os sistemas de produ??o agr?colas de forma sustent?vel. O objetivo deste trabalho foi estudar o perfil da comunidade bacteriana e potencial celulol?tico de bact?rias isoladas de tr?s diferentes esp?cies de invertebrados sapr?fagos. Os experimentos foram montados no Campo Experimental da Embrapa Agrobiologia, Serop?dica, Rio de Janeiro. Gong?los, da esp?cie Trigoniulus corallinus, foram coletados em pilhas de compostos vegetais presentes em torno do campo experiemental, que posteriormente foram incubados durante 60 dias, sob seis diferentes dietas. A diversidade bacteriana do trato intestinal dos invertebrados foi analisada atrav?s da t?cnica de PCR"DGGE por amplifica??o do gene 16S rDNA PCR por eletroforese em gel com gradiente desnaturante (DGGE); foram utilizados dois dom?nios Bacteria e Actinobact?ria. Algumas bandas do gel de DGGE foram extra?das e sequenciadas. Para avaliar o potencial quanto ? produ??o de celulases em resposta ? presen?a de carboxi"metil"celulose (CMC) das bact?rias isoladas, foi utilizada a t?cnica de colora??o vermelho Congo, e os valores foram expressos atrav?s de (Ie) ?ndice enzim?tico. A partir dos maiores valores de (Ie), foram selecionadas vinte e tr?s bact?rias para a an?lise de sequenciamento do gene 16S rDNA. Ap?s a identifica??o filogen?tica, foi avaliado o potencial celulol?tico, atrav?s de testes de atividade celulol?tica de endoglucanases (CMCase) e endo e exoglucanases (FPase). Para determinar a massa molecular e atividade das enzimas foram realizados g?is de poliacrilamida (SDS"PAGE) e zimograma. Os resultados obtidos na t?cnica de DGGE, os perfis de bandas de DGGE mostrou que a microbiota intestinal dos invertebrados, det?m grupos bacterianos distintos. Pode"se inferir neste ponto, que apesar das comunidades possu?rem abund?ncia similar, como as esp?cies de Trigoniulus corallinus e Cubaris murina, os grupos que comp?em esta abund?ncia foram diferentes entre as esp?cies de invertebrados. A partir dos clones de bandas incisadas, foram sequ?nciados membros de tr?s filos, Proteobacteria, Firmicutes e Bacteroidetes. Atrav?s da an?lise filogen?tica, foi poss?vel identificar as 23 esp?cies de bact?rias. Apresentando dois filos distintos Actinomicetos e Firmicutes, o maior g?nero identificado foi Streptomyces, seguido de um isolado para Bacillus, Paenibacillus e Staphylococcus. O trato intestinal das tr?s esp?cies de invertebrados sapr?fagos revelou ser um ambiente h?bil ? prospec??o de bact?rias com efici?ncia celulol?tica, com alto potencial para futuros estudos biotecnol?gico.

Made available in DSpace on 2014-12-17T15:30:51Z (GMT). No. of bitstreams: 1 AnaRLA.pdf: 621369 bytes, checksum: 16e9cd521a5599eb0289fb550685807b (MD5) Previous issue date: 2009-01-12 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / Periodontal infections consist of a group of inflammatory conditions caused by microorganisms that colonize the tooth surface through the formation of dental biofilm. Chronic infections such as periodontitis have been associated to the development and progression of atherosclerosis. AIM: Detect cultivatable and non-cultivatable periodontopathogenic bacteria in atheromatous plaques; search for factors associated to the presence of these bacteria in the atheromatous plaques and characterize the presence of cultivatable and non-cultivatable bacteria in these plaques. METHODOLOGY: A cross-sectional study was performed with a sample of 30 patients diagnosed with atherosclerosis in the carotid, coronary or femoral arteries and surgically treated with angioplasty and stent implant, bypass or endarterectomy. The plaques were collected during surgery and analyzed using the PCR molecular technique for the presence of the DNA of the cultivatable bacteria Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis and Treponema denticola and of the non-cultivatable Synergistes phylotypes. The patients were examined in the infirmary, after the surgery, where they also responded to a questionnaire aimed at determining factors associated to the presence of periodontopathogenic bacteria in the atheromatous plaques. RESULTS: All patients with tooth (66,7%) possessed disease periodontal, being 95% severe and 65% widespread. No periodontopathogenic bacteria were found in the atheromatous plaques. However, four samples (13.3%) were positive for the presence of bacteria. Of these, three participants were dentate, being two carriers of widespread severe chronic periodontite and one of located severe chronic periodontitis. None of them told the accomplishment of procedures associated to possible bacteremia episodes, as treatment endodontic, extraction the last six months or some procedure surgical dental. CONCLUSION: The periodontopathogenic bacteria studied were not found in the atheromatous plaques, making it impossible to establish the prevalence of these pathogens or the factors associated to their presence in plaques, the detection of positive samples for bacteria suggests that other periodontal and non-periodontal pathogens be studied in an attempt at discovering the association or not between periodontal disease and/or others infections and atherosclerosis, from the presence of these bacteria in atheromas / As infec??es periodontais compreendem um grupo de condi??es inflamat?rias, causadas por microrganismos que colonizam a superf?cie dent?ria, atrav?s da forma??o do biofilme dent?rio. Atualmente, infec??es cr?nicas como as periodontais t?m sido associadas ao desenvolvimento e progress?o da aterosclerose. OBJETIVOS: Detectar bact?rias periodontopatog?nicas cultiv?veis e n?o cultiv?veis em placas ateromatosas; buscar fatores associados ? presen?a destas bact?rias nas placas ateromatosas e caracterizar a presen?a de bact?rias cultiv?veis e n?o cultiv?veis em placas ateromatosas. METODOLOGIA: Foi realizado um estudo seccional, utilizando uma amostra de 30 pacientes que apresentaram o diagn?stico de aterosclerose nas art?rias car?tidas, coronarianas ou femorais, e foram tratados cirurgicamente atrav?s da realiza??o dos procedimentos de angioplastia com implante de stent, bypasse ou endartarectomia. As placas foram coletadas durante as cirurgias realizadas e analisadas atrav?s da t?cnica molecular de PCR para a presen?a de DNA das bact?rias periodontais cultiv?veis Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis e Treponema denticola e o filotipo n?o-cultiv?vel Synergistes species. Os pacientes foram examinados no leito da enfermaria, ap?s as cirurgias, onde tamb?m responderam a um question?rio cujo objetivo foi buscar fatores associados ? presen?a de bact?rias periodontopatog?nicas nas placas ateromatosas. RESULTADOS: Todos os pacientes dentados (66,7%) possu?am doen?a periodontal, sendo 95% severa e 65% generalizada.Nenhuma bact?ria periodontopatog?nica pesquisada foi encontrada nas placas ateromatosas. No entanto, quatro amostras (13,3%) foram positivas para a presen?a de bact?rias. Destas, tr?s participantes eram dentados, sendo dois portadores de periodontite cr?nica severa generalizada e um de periodontite cr?nica severa localizada. Nenhum deles relatou a realiza??o de procedimentos associados a poss?veis epis?dios de bacteremia, como tratamento endod?ntico, exodontia nos ?ltimos seis meses ou algum procedimento cir?rgico odontol?gico. CONCLUS?O: As bact?rias periodontopatog?nicas estudadas n?o foram encontradas nas placas ateromatosas, n?o pudendo ser estabelecida a preval?ncia destes pat?genos e nem os fatores associados ? presen?a deles nas placas, mas, a detec??o das amostras positivas para bact?rias abre caminhos para que outros pat?genos periodontais e n?o periodontais sejam estudados na tentativa de elucidar de maneira definitiva a associa??o ou n?o entre a doen?a periodontal e/ou outras infec??es e a aterosclerose, atrav?s da presen?a destas bact?rias nos ateromas

Made available in DSpace on 2015-04-14T14:51:15Z (GMT). No. of bitstreams: 1 437674.pdf: 1507951 bytes, checksum: 2f5468fe0bdb2401a723df07c96e2c43 (MD5) Previous issue date: 2011-09-30 / Acinetobacter baumannii is an important opportunistic pathogen commonly associated with nosocomial infections, especially in patients hospitalized in intensive care units (ICUs). This microorganism is renowned for its ability to survive under adverse conditions in the environment for extended periods, as well as to rapidly acquire resistance to antimicrobial drugs. Nowadays, the increasing antimicrobial resistance of A. baumannii has been a great challenge for the medical community, since there are few effective options for the treatment of infections caused by this organism. The aim of this study was to evaluate the presence of the A. baumannii from an ICU environment and to characterize the antimicrobial drug resistance of the isolates obtained, as well as of the isolates from patients in ICU of the same hospital in which it was collected environmental samples. For this, 886 environmental and gloves samples were collected from an ICU of S?o Lucas Hospital, Porto Alegre, Brazil, and 46 clinical isolates were obtained from the Laboratory of the same hospital. After the identification of the isolates as A. baumannii by PCR using as target 16S rDNA and blaOXA-51 genes, the resistance to 20 antimicrobial drugs and the production of metallo-beta-lactamases were evaluated in isolates presenting carbapenem reduced susceptibility. Also, it was evaluated the presence of integrons and blaOXA-23 and blaIMP genes by PCR. A. baumannii was identified in 9.6% of environmental and glove samples collected. High percentage of multiresistant (MDR) isolates was found, as well as it was detected high rates of reduced susceptibility to carbapenems. All 89 isolates integron positive were MDR. Between isolates with reduced susceptibility to carbapenems, all presented blaOXA-23, and 41.4% non-clinical and 54% clinical carried the blaIMP. High resistance to polymyxin B was detected, mainly in non-clinical isolates. Although high prevalence has been found in clinical and non-clinical isolates, the latter constitute a great concern, because they can indicate the hospital environment as a reservoir of MDR A. baumannii. / Acinetobacter baumannii ? um importante pat?geno oportunista comumente associado a infec??es nosocomiais, especialmente em pacientes hospitalizados em unidades de tratamento intensivo (UTIs). Este organismo ? reconhecido por sua capacidade de sobreviver em condi??es adversas no ambiente por per?odos prolongados, bem como de facilmente adquirir resist?ncia a drogas antimicrobianas. Atualmente, a crescente resist?ncia antimicrobiana de A. baumannii tem constitu?do um grande desafio para a comunidade m?dica, uma vez que existem poucas op??es efetivas para o tratamento de infec??es causadas por este microrganismo. O objetivo deste estudo foi avaliar a presen?a de A. baumannii no ambiente de uma UTI e caracterizar a resist?ncia a drogas antimicrobianas dos isolados obtidos, bem como de isolados de pacientes internados na UTI do mesmo hospital no qual as amostras ambientais foram coletadas. Para tanto, 886 amostras ambientais e de luvas foram coletadas de uma UTI do Hospital S?o Lucas, Porto Alegre, Brasil, e 46 isolados cl?nicos foram obtidos no Laborat?rio do mesmo hospital. Ap?s a identifica??o dos isolados como A. baumannii atrav?s de PCR utilizando como alvos os genes rDNA 16S e blaOXA-51, foram determinadas a resist?ncia a 20 drogas antimicrobianas previstas pelo CLSI e a produ??o de metalo-betalactamases em isolados com suscetibilidade reduzida aos carbapen?micos. Tamb?m foi avaliada a presen?a de integrons e dos genes blaOXA-23 e blaIMP atrav?s de PCR. A. baumannii foi identificado em 9,6% das amostras ambientais e de luvas coletadas. Obteve-se um alto percentual de isolados multirresistentes (MDR), assim como foram detectadas alta taxas de suscetibilidade reduzida aos carbapen?micos. Todos os 89 isolados que apresentaram integrons foram MDR. Dentre os isolados com suscetibilidade reduzida aos carbapen?micos, todos apresentaram o gene blaOXA-23, e 41,4% n?o-cl?nicos e 54% cl?nicos carrearam o gene blaIMP. Alta resist?ncia ? polimixina B foi detectada, principalmente em isolados n?o-cl?nicos. Embora alta preval?ncia de resist?ncia antimicrobiana tenha sido encontrada em isolados cl?nicos e n?o cl?nicos, os ?ltimos constituem grande preocupa??o, pois podem indicar o ambiente hospitalar como um reservat?rio de A. baumannii MDR.

Submitted by Setor de Tratamento da Informa??o - BC/PUCRS (tede2@pucrs.br) on 2015-09-29T12:35:39Z No. of bitstreams: 1 475295 Texto Parcial.pdf: 664846 bytes, checksum: 9cb2bbfb96e686e96f2556c4ca6750c4 (MD5) / Made available in DSpace on 2015-09-29T12:35:39Z (GMT). No. of bitstreams: 1 475295 Texto Parcial.pdf: 664846 bytes, checksum: 9cb2bbfb96e686e96f2556c4ca6750c4 (MD5) Previous issue date: 2015-02-25 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior - CAPES / Funda??o de Amparo ? Pesquisa do Estado do Rio Grande do Sul - FAPERGS / The species of the ?C. parapsilosis complex? are common etiological agents of nosocomial candidemia, and C. parapsilosis sensu stricto is one of non-albicans Candida species with the highest incidences in clinical infections, primarily related to implanted medical devices. In this study, we identified 29 isolates comprising the ?C. parapsilosis complex? to species level, all previously obtained from the hospital environment and medical tools. The isolates were also characterized for in vitro activity of aspartyl proteinase and phospholipase, as well as for their ability to form biofilms. The isolates identified as C. parapsilosis sensu stricto were also evaluated for their capability to interact with Staphylococcus aureus and Acinetobacter sp. in two-species polymicrobial biofilms. These biofilms were then analyzed for their tolerance to treatments with increasing concentrations of antimicrobials drugs and sanitizers. The results indicated that 75.9% of the isolates were identified as C. parapsilosis sensu stricto, 24.1% as Candida metapsilosis and none as Candida orthopsilosis. Regarding C. parapsilosis sensu stricto, all isolates were very strong producers of aspartyl proteinase, and 13.6% of phospholipase. Regarding C. metapsilosis, 71.4% and 14.3% of the isolates showed very strong aspartyl proteinase and phospholipase activity, respectively. Moreover, all isolates were able to form biofilm on polystyrene surface. Among the C. parapsilosis sensu stricto isolates, 9.1%, 45.4% and 45.4% were strong, moderate and weak biofilm producers, respectively. Regarding C. metapsilosis, 71.4% were moderate and 28.6% were weak biofilm producers.We also demonstrated that C. parapsilosis sensu stricto was capable of associating synergistically with both bacteria tested, since in polymicrobial biofilms a significantly higher number of bacterial cells adhered, compared to their own monomicrobial condition. However, bacterial cells did not interfere on the efficiency of yeast biofilm formation. When testing sanitizers, we showed that 70% ethyl alcohol and 1% sodium hypochlorite were effective to significantly decrease the number of viable cells, although they have not been able to eliminate the microbial populations of the biofilms. Our data also showed that the cells from all monomicrobial biofilms exhibited elevated tolerance to their respective antimicrobial drugs, at higher doses than their pre-determined minimal inhibitory concentration values. Nevertheless, biofilms of 6, 12 and 24 h of C. parapsilosis sensu stricto presented some decrease in cell viability to the treatment with ketoconazole, whereas 48 h biofilms were resistant to this antifungal. In polymicrobial biofilms, the bacterial cells did not affect the tolerance of yeast isolates to this antimicrobial. Conversely, S. aureus and Acinetobacter sp. cells were even more tolerant to the treatment with vancomycin and polymyxin B, respectively, when they were in polymicrobial biofilms, which was significantly different from their respective monomicrobial condition.The results from this work revealed the ability of ?C. parapsilosis complex? isolates from nosocomial environment to express important virulence factors, as well as to interact synergistically with bacterial species of clinical importance. This data is clinically relevant, since such phenotypic features may represent an important risk in terms of nosocomial infection to hospitalized patients. / As esp?cies do ?complexo Candida parapsilosis? mostram-se como frequentes agentes etiol?gicos de candidemias nosocomiais, sendo a C. parapsilosis sensu stricto uma das esp?cies n?o-albicans de Candida de maior incid?ncia em infec??es cl?nicas, estando relacionada principalmente com dispositivos m?dicos implantados. Neste estudo, identificamos, em n?vel de esp?cie, 29 isolados pertencentes ao ?complexo Candida parapsilosis?, todos previamente obtidos a partir do ambiente hospitalar e de dispositivos m?dicos. Os isolados tamb?m foram caracterizados quanto ? atividade in vitro de aspartil proteinase e fosfolipase, e quanto ? habilidade de formar biofilmes. Os isolados identificados como C. parapsilosis sensu stricto foram avaliados quanto ? capacidade de interagir com Staphylococcus aureus e Acinetobacter sp. no desenvolvimento de biofilmes polimicrobianos de duas esp?cies. Estes biofilmes foram ent?o analisados quanto ? sua capacidade de tolerar o tratamento com concentra??es crescentes de f?rmacos antimicrobianos e sanitizantes. Como resultados, 75,9% dos isolados foram identificados como C. parapsilosis sensu stricto, 24,1% como Candida metapsilosis e nenhum como Candida orthopsilosis. Em rela??o ? C. parapsilosis sensu stricto, todos os isolados mostraram-se como produtores muito fortes de aspartil proteinase e 13,6% de fosfolipase. Em rela??o ? C. metapsilosis, 71,4% e 14,3% dos isolados apresentaram atividade muito forte de aspartil proteinase e fosfolipase, respectivamente.Al?m disso, todos os isolados foram capazes de formar biofilme em superf?cie de poliestireno. Dentre os isolados de C. parapsilosis sensu stricto, 9,1%, 45,4% e 45,4% mostraram-se como produtores fortes, moderados e fracos de biofilme, respectivamente. Em rela??o aos de C. metapsilosis, 71,4% foram moderados e 28,6% foram fracos formadores de biofilme. Demonstramos tamb?m que a C. parapsilosis sensu stricto foi capaz de se associar de forma sin?rgica com ambas as bact?rias testadas, pois nos biofilmes polimicrobianos um n?mero significativamente maior de c?lulas bacterianas se aderiram em compara??o ? sua condi??o monomicrobiana. Entretanto, as bact?rias n?o interferiram na efici?ncia de forma??o de biofilmes da levedura. O tratamento com sanitizantes mostrou que o ?lcool et?lico a 70% e o hipoclorito de s?dio a 1% foram eficazes em diminuir significativamente o n?mero de c?lulas vi?veis, mas n?o foram capazes, mesmo assim, de eliminar as popula??es microbianas dos biofilmes. Al?m disso, nossos dados mostraram que as c?lulas integrantes de todos os biofilmes monomicrobianos avaliados apresentaram elevada toler?ncia aos seus respectivos antimicrobianos, em doses superiores aos seus valores de concentra??o inibit?ria m?nima, previamente determinados.Mesmo assim, os biofilmes de C. parapsilosis sensu stricto de 6, 12 e 24 h mostraram alguma perda de viabilidade celular ao tratamento com cetoconazol, enquanto biofilmes de 48 h se mostraram resistentes a este antif?ngico. Nos biofilmes polimicrobianos, a presen?a das c?lulas bacterianas n?o influenciou a toler?ncia das leveduras ao antimicrobiano. Por outro lado, as c?lulas de S. aureus e Acinetobacter sp. foram ainda mais tolerantes ao tratamento com vancomicina e polimixina B, respectivamente, quando em biofilmes polimicrobianos, de forma significativa em compara??o ?s suas respectivas condi??es monomicrobianas. Os resultados deste trabalho revelaram a capacidade de isolados do ?complexo C. parapsilosis? do ambiente nosocomial de expressar importantes fatores de virul?ncia, bem como de interagir sinergicamente com bact?rias de import?ncia cl?nica. Em conjunto, estas informa??es mostram-se de grande relev?ncia cl?nica, em fun??o de tais caracter?sticas fenot?picas representarem um importante risco em termos de infec??o hospitalar a pacientes internados.