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Full-scale anaerobic sequencing batch biofilm reactor for sulfate-rich wastewater treatment

SARTI, Arnaldo; SILVA, Ariovaldo J.; ZAIAT, Marcelo; FORESTI, Eugenio
Fonte: DESALINATION PUBL Publicador: DESALINATION PUBL
Tipo: Artigo de Revista Científica
ENG
Relevância na Pesquisa
36.83%
This paper describes the performance and biofilm characteristics of a full-scale anaerobic sequencing batch biofilm reactor (ASBBR; 20 m(3)) containing biomass immobilized on an inert support (mineral coal) for the treatment of industrial wastewater containing a high sulfate concentration. The ASBBR reactor was operated during 110 cycles (48 h each) at sulfate loading rates ranging from 6.9 to 62.4 kgSO(4)(2-)/cycle corresponding to sulfate concentrations of 0.58-5.2 gSO(4)(2-)/L. Domestic sewage and ethanol were utilized as electron donors for sulfate reduction. After 71 cycles the mean sulfate removal efficiency was 99%, demonstrating a high potential for biological sulfate reduction. The biofilm formed in the reactor occurred in two different patterns, one at the beginning of the colonization and the other of a mature biofilm. These different colonization patterns are due to the low adhesion of the microorganisms on the inert support in the start-up period. The biofilm population is mainly made up of syntrophic consortia among sulfate-reducing bacteria and methanogenic archaea such as Methanosaeta spp.; Fundacao de Amparo a Pesquisa do Estado de Sao Paulo-FAPESP[03/07799-2]; Conselho Nacional de Desenvolvimento Cientifico e Tecnolgico-CNPq[019/2004]; Conselho Nacional de Desenvolvimento Cientifico e Tecnolgico-CNPq[478355/2004-1]

Antimicrobial activity and enterococcus faecalis biofilm formation on chlorhexidine varnishes

Arias-Moliz, Maria-Teresa; Ferrer-Luque, Carmen-Maria; Gonzalez-Rodriguez, Maria-Paloma; Navarro-Escobar, Esther; de Freitas, Marcia-Furtado-Antunes; Baca, Pilar
Fonte: MEDICINA ORAL S L; VALENCIA Publicador: MEDICINA ORAL S L; VALENCIA
Tipo: Artigo de Revista Científica
ENG
Relevância na Pesquisa
36.83%
Objective: To evaluate, in vitro, the antimicrobial activity and biofilm formation of three chlorhexidine varnishes in four Enterococcus faecalis strains: E. faecalis ATCC 29212, E. faecalis EF-D1 (from failed endodontic treatment), E. faecalis 072 (cheese) and E. faecalis U-1765 (nosocomial infection), and one Enterococcus durans strain (failed endodontic treatment). Study Design: The direct contact test was used to study the antimicrobial activity. Bacterial suspensions were exposed for one hour to EC40, Cervitec (CE) and Cervitec Plus (CEP) varnishes. "Eradication" was defined as 100% bacterial kill. The formation of enterococci biofilms was tested on the surface of the varnishes after 24 hours of incubation and expressed as percentage of biofilm reduction. Results: EC40 eradicated all strains except E. faecalis ATCC 29212, where 98.78% kill was achieved. CE and CEP showed antimicrobial activity against all the strains, but most clearly against E. durans and E. faecalis 072. EC40 completely inhibited the formation of biofilm of E. faecalis ATCC 29212, E. faecalis 072 and E. durans. CE and CEP led to over 92% of biofilm reduction, except in the case of E. faecalis U-1765 on CEP (76.42%). Conclusion: The three varnishes studied were seen to be effective in killing the tested strains of enterococci and in inhibiting the formation of biofilm...

Effect of Chlorhexidine on Denture Biofilm Accumulation

Andrade, Ingrid Machado de; Cruz, Patricia Costa; Lovato-Silva, Cláudia H.; Souza, Raphael F. de; Souza-Gugelmin, Maria Cristina Monteiro; Paranhos, Helena de Freitas Oliveira
Fonte: WILEY-BLACKWELL; MALDEN Publicador: WILEY-BLACKWELL; MALDEN
Tipo: Artigo de Revista Científica
ENG
Relevância na Pesquisa
36.83%
Purpose: Adequate denture hygiene can prevent and treat infection in edentulous patients, who are frequently elderly and have difficulty brushing their teeth. This study evaluated the efficacy of complete denture biofilm removal using a chlorhexidine solution in two concentrations: 0.12% and 2.0%. Materials and Methods: Sixty complete denture wearers participated in a trial for 21 days after receiving brushing instructions. They were distributed into three groups, according to the tested solution and regimen (n = 20): (G1) Control (daily overnight soaking in water); (G2) daily immersion at home in 0.12% chlorhexidine for 20 minutes after dinner; and (G3) a single immersion in 2.0% chlorhexidine for 5 minutes at the end of the experimental period, performed by a professional. Biofilm coverage area (%) was quantified on the internal surface of maxillary dentures at baseline and after 21 days. Afterward, the differences between initial and posttreatment results were compared by means of the Kruskal-Wallis test (a = 0.05). Results: Median values for biofilm coverage area after treatment were: (G1) 36.0%; (G2) 5.3%; and (G3) 1.4%. Differences were significant (KW = 35.25; p < 0.001), although G2 and G3 presented similar efficacy in terms of biofilm removal. Conclusions: Both chlorhexidine-based treatments had a similar ability to remove denture biofilm. Immersion in 0.12% or 2.0% chlorhexidine solutions can be used as an auxiliary method for cleaning complete dentures.; Sao Paulo Research Foundation (FAPESP) [2005/55705-2]

Avaliação clínica da eficácia dos métodos químico (peróxido alcalino) e mecânico (ultra-som) frente à propriedade de remoção do biofilme de próteses totais; Clinical evaluation of the efficacy on biofilm removal from complete denture of the chemical (alkaline peroxide) and mecanical (ultrasonic) methods

Cruz, Patricia Costa
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Dissertação de Mestrado Formato: application/pdf
Publicado em 07/11/2007 PT
Relevância na Pesquisa
36.83%
O objetivo deste trabalho foi avaliar clinicamente a capacidade de remoção do biofilme da prótese total dos métodos de higiene: químico (pastilha efervescente para imersão de próteses totais à base de peróxido alcalino), mecânico (aparelho ultra-sônico), e associado (pastilha efervescente + aparelho ultra-sônico). Oitenta pacientes (usuários de próteses totais superiores e inferiores) participaram de um período experimental de 21 dias e foram distribuídos em 4 grupos (n=20): 1) Controle - escovação das próteses com escova específica (Bitufo) 3 vezes ao dia (após café da manhã, almoço e jantar) com água; 2) Químico - escovação das próteses com escova específica (Bitufo) 3 vezes ao dia (após café da manhã, almoço e jantar) com água e imersão em recipiente contendo ½ copo de água morna e 01 pastilha efervescente Corega Tabs por 5 minutos; 3) Mecânico - escovação das próteses com escova específica (Bitufo) 3 vezes ao dia (após café da manhã, almoço e jantar) com água, e uma única agitação ultra-sônica por 15 minutos ao final do período experimental (21 dias); 4) Associado - associação dos métodos 2 e 3. Para a quantificação do biofilme, as superfícies internas das próteses totais superiores foram evidenciadas (vermelho neutro 1%)...

Capacidade de dissolução do hipoclorito de sódio e da clorexidina sobre biofilme oral formado 'in situ'; Biofilm dissolution and cleaning ability of different irrigant solutions on intraorally infected dentin

Perochena, Aldo Enrique Del Carpio
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Dissertação de Mestrado Formato: application/pdf
Publicado em 18/04/2011 PT
Relevância na Pesquisa
36.83%
O objetivo deste estudo foi avaliar o efeito do hipoclorito de sódio e a clorexidina sobre biofilme dental formado in situcom relação a: concentração do hipoclorito de sódio (1%, 2.5% e 5%) e clorexidina 2%, tempo de exposição à solução irrigadora (5, 15 e 30 minutos.), volumes das soluções (500 µl e 1 mL), espessura do biofilme e área de limpeza segundo analise morfométrica. Foram utilizados 120 blocos de dentina bovina esterilizada, colocados em um aparelho intraoral e utilizados por um voluntário durante 3 dias. Transcorrido o período experimental as amostras foram retiradas e coradas com 50 µl de laranja de acridina para determinar a espessura do biofilme pre irrigação por meio do Microscopio confocal de varredura laser (CLSM). Foram conformados 12 grupos experimentais com 10 blocos cada um e irrigados com NaOCl e clorexina. Dez amostras foram irrigadas com 500 µl (N=5) e 1mL (N=5) de NaOCl 1% por: 5 min (G1), 15 min (G2) e 30 min (G3). Dez amostras foram irrigadas com 500 µl (N=5) e 1mL (N=5) de NaOCl 2.5% por: 5 min (G4), 15 min (G5) e 30 min (G6). Dez amostras foram irrigadas com 500 µl (N=5) e 1mL (N=5) de NaOCl 5% por: 5 min (G7), 15 min (G8) e 30 min (G9). Dez amostras foram irrigadas com 500 l (N=5) e 1mL (N=5) de Clorexidina 2% por: 5 min (G10)...

Identificação molecular de Staphylococcus aureus formadores de biofilmes em ambiente de ordenha; Molecular identification of Staphylococcus aureus biofilm-producers in milking environment

Lee, Sarah Hwa In
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Dissertação de Mestrado Formato: application/pdf
Publicado em 28/02/2012 PT
Relevância na Pesquisa
36.83%
O objetivo do presente estudo foi avaliar a ocorrência de cepas de Staphylococcus aureus no ambiente de ordenha, analisar seu perfil genético e a produção de biofilme, provenientes de 10 propriedades localizadas nas regiões de Franca e Ribeirão Preto, estado de São Paulo, Brasil. Foram analisadas 220 amostras de leite individual de vacas positivas no teste CMT (California Mastitis Test), 120 amostras de leite de tanque de expansão, 389 swabs de utensílios e equipamento relacionados com ordenha e 120 swabs de mãos de manipuladores. As coletas de amostras foram realizadas mensalmente durante o período de agosto/2010 a janeiro/2011. Das 849 amostras analisadas, 56 cepas de S. aureus (6,6%) foram isoladas, sendo 12 (5,4%) de leite individual de vacas, 26 (21,6%) de leite de tanque de expansão, 14 (3,6%) de utensílios e equipamentos e 4 (6,9%) de mãos de manipuladores. Os resultados indicam uma baixa prevalência de S. aureus nas propriedades analisadas, não havendo diferença significativa entre as frequências encontradas nas duas regiões analisadas. A técnica de PFGE (pulsed-field gel electrophoresis) permitiu identificar 31 perfis genéticos (pulsotipos), utilizando-se a enzima de restrição SmaI. Nos ensaios de produção de biofilmes em microplaca...

Avaliação do papel de óxido nítrico, de óleos essenciais e de sanitizantes na dispersão de biofilmes de Listeria monocytogenes em superfície abiótica; Evaluation of the role of nitric oxide, essential oils and sanitizers in biofilm dispersion of Listeria monocytogenes on abiotic surface

Teixeira, Fernanda Barbosa dos Reis
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Tese de Doutorado Formato: application/pdf
Publicado em 12/09/2014 PT
Relevância na Pesquisa
36.83%
Biofilmes de Listeria monocytogenes são fontes potenciais de contaminação de alimentos processados e podem diminuir a efetividade de procedimentos de higienização e sanitização nas indústrias. No presente estudo foi avaliada a estrutura e a dispersão de biofilmes formados por duas cepas de L. monocytogenes em diferentes superfícies, como aço inoxidável, vidro e poliestireno. Foram utilizados diferentes sistemas de cultivo como microplacas de 96 poços de poliestireno e de aço inoxidável, microplacas de 24 poços contendo lâminas circulares de aço inoxidável ou de vidro e, câmaras de poliestireno contendo 8 poços com fundo de borossilicato (vidro). Os experimentos foram realizados com incubação por 1, 4 e 8 dias a 25°C. A formação de biofilme foi verificada em microplacas de 96 de poliestireno e de aço inoxidável através do método de quantificação de biomassa do biofilme por coloração com cristal violeta, e também em sistema de microplaca de 24 poços contendo lâminas circulares de aço inoxidável ou de vidro, através de enumeração em placa das células aderidas nas superfícies. As estruturas dos biofilmes foram observadas por meio de microscopia de fluorescência (para o sistema de microplaca de 24 poços contendo lâminas circulares de aço inoxidável) e através de microscopia confocal a laser (para o sistema com câmaras com fundo de vidro). Para isso...

Influência de diferentes condições de cultivo na formação de biofilme por Escherichia coli enteropatogênica atípica (EPECa) e pesquisa de genes relacionados.; Influence of different culture conditions on biofilm formation by atypical enteropathogenic Escherichia coli (aEPEC) and search of related genes.

Mota, Cristiane Moda
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Dissertação de Mestrado Formato: application/pdf
Publicado em 25/04/2014 PT
Relevância na Pesquisa
36.83%
EPECa tem sido identificada como o principal agente de diarreia aguda em crianças de países em desenvolvimento. Biofilmes são estruturas bacterianas envoltas por uma matriz de exopolissacarídeos. O objetivo deste estudo foi verificar a influência de diferentes condições de cultivo na formação de biofilme por EPECa isoladas de crianças com diarreia e pesquisar a presença de genes relacionados com a formação de biofilme. As sequências genéticas dos genes csgA, crl, fimH e bcsA foram pesquisadas através da PCR e verificadas em 6 (26%), 23 (100%), 22 (95,6%) e 23 (100%) das amostras respectivamente. A formação de biofilme em placas de MTP por EPECa foi melhor evidenciada em meio LB sem sal a 26 °C e em caldo E. coli a 37 °C, tanto em número de amostras quanto em intensidade da formação de biofilme. As microscopias confocal e de varredura propiciaram uma análise qualitativa de microcolônias e pilares, além de EPS respectivamente. As condições de cultivo devem ser usadas com precaução para realmente aferir a capacidade de formação de biofilme por amostras de EPECa.; aEPEC has been identified as the main agent of acute diarrhea in children in developing countries. Biofilms are bacterial structures which are surrounded by a matrix of exopolysaccharides. The aim of this study was investigate the influence of different culture conditions on biofilm formation by 23 aEPEC strains isolated from children with diarrhea and search for the presence of genes related to biofilm formation. The genetic sequences of the csgA...

Biofilm production using distinct media and antimicrobial susceptibility profile of Pseudomonas aeruginosa

Perez, Leandro Reus Rodrigues; Barth, Afonso Luis
Fonte: Universidade Federal do Rio Grande do Sul Publicador: Universidade Federal do Rio Grande do Sul
Tipo: Artigo de Revista Científica Formato: application/pdf
ENG
Relevância na Pesquisa
36.83%
Biofilm production is an important mechanism for bacterial survival and its occurrence together with antimicrobial resistance represents a challenge for clinical management. Here, we evaluated the ability for biofilm production among P. aeruginosa isolates from patients with or without cystic fibrosis (CF) using two distinct media, besides determining the antimicrobial susceptibility profile of these isolates for eight antimicrobial agents. The ability for biofilm production when TSB medium was used was higher than when used CF sputum media (p = 0.0198). However, P. aeruginosa isolates from CF have demonstrated similar performance for biofilm production, independently of the medium used. Besides, among the biofilm-producing isolates, those recovered from CF were more resistant to the carbapenems (meropenem and imipenem) agents than those isolates from non-CF isolates.

Evaluation of Candida albicans adhesion and biofilm formation on a denture base acrylic resin containing silver nanoparticles

Wady, A. F.; Machado, A. L.; Zucolotto, V.; Zamperini, C. A.; Berni, E.; Vergani, Carlos Eduardo
Fonte: Wiley-Blackwell Publicador: Wiley-Blackwell
Tipo: Artigo de Revista Científica Formato: 1163-1172
ENG
Relevância na Pesquisa
36.83%
Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP); Processo FAPESP: 08/11700-5; Processo FAPESP: 08/07454-9; Aim: This study firstly evaluated the activity of a silver nanoparticle (AgNPs) solution against Candida albicans and then the effect of incorporation of AgNPs into a denture base acrylic resin on the materials hydrophobicity, C.albicans adhesion and biofilm formation. Methods and Results: The AgNPs solution was synthesized by chemical reduction and characterized. Minimum inhibitory (MIC) and minimum fungicidal (MFC) concentrations for planktonic cells and sessile cells (MFCs) of the AgNPs solution against C.albicans were determined. Specimens (n = 360) of silver-incorporated acrylic resin at concentrations of 1000, 750, 500, 250 and 30 ppm were also prepared and stored in PBS for 0, 7, 90 and 180 days. Control was acrylic resin without AgNPs (0 ppm). After the storage periods, contact angles were measured and the specimens were used for C.albicans adherence (37 degrees C; 90 min; n = 9) and biofilm formation (37 degrees C; 48 h; n = 9) by XTT reduction assay. MIC, MFC and MFCs values were 3.98, 15.63 and 1000 ppm, respectively. Incorporation of AgNPs reduced the hydrophobicity of the resin. No effect on adherence and biofilm formation was observed. At 90 and 180 days of storage...

Antimicrobial activity of root canal irrigants associated with cetrimide against biofilm and planktonic Enterococcus Faecalis

Nascimento, Camila Almeida; Tanomaru-Filho, Mario; Faria-Júnior, Norberto Batista de; Faria, Gisele; Guerreiro-Tanomaru, Juliane Maria
Fonte: Universidade Estadual Paulista Publicador: Universidade Estadual Paulista
Tipo: Artigo de Revista Científica Formato: 79-83
ENG
Relevância na Pesquisa
36.83%
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES); Aim: To evaluate the antibacterial activity of sodium hypochlorite (NaOCl) and chlorhexidine (CHX) alone or associated with cetrimide (CTR), and QMiX against biofilm and planktonic Enterococcus faecalis (E. faecalis) [American type culture collection (ATCC) 29212]. Materials and methods: The solutions 2.5% NaOCl, 2.5% NaOCl + 0.2% CTR, 2% CHX, 2% CHX + 0.2% CTR, 0.2% CTR, and QMiX were evaluated. E. faecalis biofilms were induced for 14 days on bovine dentin blocks. The irrigants were evaluated after contact with E. faecalis suspension and biofilm for 1 and 3 minutes. After that, serial decimal dilutions were made and plated on tryptic soy agar (TSA) medium. Plates were incubated for 24 hours at 37°C and the colony-forming unit (CFU) 1 ml was determined. Data were subjected to ANOVA and Tukey’s tests at 5% significance. Results: All microorganisms were eliminated by direct contact of the irrigants with planktonic cells. Only NaOCl and NaOCl + CTR were able to completely eliminate the microorganisms by direct contact with E. faecalis biofilm. CHX presented effectiveness similar to CHX + CTR CTR, and QMiX after 1 minute of contact and similar to NaOCl and NaOCl + CTR after 3 minutes (p > 0.05)...

Evaluation of Candida albicans adhesion and biofilm formation on a denture base acrylic resin containing silver nanoparticles

Wady, A. F.; Machado, A. L.; Zucolotto, V.; Zamperini, C. A.; Berni, E.; Vergani, C. E.
Fonte: Wiley-Blackwell; Malden Publicador: Wiley-Blackwell; Malden
Tipo: Artigo de Revista Científica
ENG
Relevância na Pesquisa
36.83%
Aim: This study firstly evaluated the activity of a silver nanoparticle (AgNPs) solution against Candida albicans and then the effect of incorporation of AgNPs into a denture base acrylic resin on the materials hydrophobicity, C.albicans adhesion and biofilm formation. Methods and Results: The AgNPs solution was synthesized by chemical reduction and characterized. Minimum inhibitory (MIC) and minimum fungicidal (MFC) concentrations for planktonic cells and sessile cells (MFCs) of the AgNPs solution against C.albicans were determined. Specimens (n = 360) of silver-incorporated acrylic resin at concentrations of 1000, 750, 500, 250 and 30 ppm were also prepared and stored in PBS for 0, 7, 90 and 180 days. Control was acrylic resin without AgNPs (0 ppm). After the storage periods, contact angles were measured and the specimens were used for C.albicans adherence (37 degrees C; 90 min; n = 9) and biofilm formation (37 degrees C; 48 h; n = 9) by XTT reduction assay. MIC, MFC and MFCs values were 3.98, 15.63 and 1000 ppm, respectively. Incorporation of AgNPs reduced the hydrophobicity of the resin. No effect on adherence and biofilm formation was observed. At 90 and 180 days of storage, there was significant increase in adherence and biofilm formation. Conclusions: Although the AgNPs solution had antifungal activity...

Evaluating heterotrophic growth in a nitrifying biofilm reactor using fluorescence in situ hybridization and mathematical modeling

Nogueira, R.; Elenter, D.; Brito, A. G.; Melo, L. F.; Wagner, Michael; Morgenroth, E.
Fonte: IWA Publishing Publicador: IWA Publishing
Tipo: Artigo de Revista Científica
Publicado em //2005 ENG
Relevância na Pesquisa
36.83%
The objective of this study was to evaluate the significance of heterotrophic growth in nitrifying biofilm reactors fed only with ammonium as an energy source. The diversity, abundance and spatial distribution of nitrifying bacteria were studied using a combination of molecular tools and mathematical modeling, in two biofilm reactors operated with different hydraulic retention times. The composition and distribution of nitrifying consortia in biofilms were quantified by fluorescence in situ hybridization (FISH) with rRNA-targeted oligonucleotide probes combined with confocal laser scanning microscopy (CLSM) and digital image analysis. Autotrophic and heterotrophic biofilm fractions determined by FISH were compared to the output from a multispecies model that incorporates soluble microbial products (SMP) production/consumption. In reactor R1 (short retention time) nearly 100% of the total bacteria could be identified as either ammonia- or nitrite-oxidizing bacteria by quantitative FISH analyses, while in reactor R2 (long retention time) the identification rate was only 73%, with the rest probably consisting of heterotrophs. Mathematical simulations were performed to evaluate the influence of the hydraulic retention time (HRT), biofilm thickness...

Biofilm formation by Listeria monocytogenes on stainless steel surface and biotransfer potential

Oliveira, M. M. M.; Brugnera, D. F.; Alves, E.; Piccoli, R. H.
Fonte: Sociedade Brasileira de Microbiologia Publicador: Sociedade Brasileira de Microbiologia
Tipo: Artigo de Revista Científica
Publicado em 23/08/2009 EN
Relevância na Pesquisa
36.86%
An experimental model was proposed to study biofilm formation by Listeria monocytogenes ATCC 19117 on AISI 304 (#4) stainless steel surface and biotransfer potential during this process. In this model, biofilm formation was conducted on the surface of stainless steel coupons, set on a stainless steel base with 4 divisions, each one supporting 21 coupons. Trypic Soy Broth was used as bacterial growth substrate, with incubation at 37 °C and stirring of 50 rpm. The number of adhered cells was determined after 3, 48, 96, 144, 192 and 240 hours of biofilm formation and biotransfer potential from 96 hours. Stainless steel coupons were submitted to Scanning Electron Microscopy (SEM) after 3, 144 and 240 hours. Based on the number of adhered cells and SEM, it was observed that L. monocytogenes adhered rapidly to the stainless steel surface, with mature biofilm being formed after 240 hours. The biotransfer potential of bacterium to substrate occurred at all the stages analyzed. The rapid capacity of adhesion to surface, combined with biotransfer potential throughout the biofilm formation stages, make L. monocytogenes a potential risk to the food industry. Both the experimental model developed and the methodology used were efficient in the study of biofilm formation by L. monocytogenes on stainless steel surface and biotransfer potential.

Proteome approaches combined with Fourier transform infrared spectroscopy revealed a distinctive biofilm physiology in Bordetella pertussis

Serra, D.; Lucking, G.; Weiland, F.; Schulz, S.; Gorg, A.; Yantorno, O.; Ehling-Schulz, M.
Fonte: Wiley - V C H Verlag GmbH & Co. KGaA Publicador: Wiley - V C H Verlag GmbH & Co. KGaA
Tipo: Artigo de Revista Científica
Publicado em //2008 EN
Relevância na Pesquisa
36.86%
Proteome analysis was combined with whole-cell metabolic fingerprinting to gain insight into the physiology of mature biofilm in Bordetella pertussis, the agent responsible for whooping cough. Recent reports indicate that B. pertussis adopts a sessile biofilm as a strategy to persistently colonize the human host. However, since research in the past mainly focused on the planktonic lifestyle of B. pertussis, knowledge on biofilm formation of this important human pathogen is still limited. Comparative studies were carried out by combining 2-DE and Fourier transform infrared (FT-IR) spectroscopy with multivariate statistical methods. These complementary approaches demonstrated that biofilm development has a distinctive impact on B. pertussis physiology. Results from MALDI-TOF/MS identification of proteins together with results from FT-IR spectroscopy revealed the biosynthesis of a putative acidic-type polysaccharide polymer as the most distinctive trait of B. pertussis life in a biofilm. Additionally, expression of proteins known to be involved in cellular regulatory circuits, cell attachment and virulence was altered in sessile cells, which strongly suggests a significant impact of biofilm development on B. pertussis pathogenesis. In summary...

Clonal diversity in biofilm formation by Enterococcus faecalis in response to environmental stress associated with endodontic irrigants and medicaments

Wilson, C.E.; Cathro, P.C.; Rogers, A.H.; Briggs, N.; Zilm, P.S.
Fonte: John Wiley & Sons Publicador: John Wiley & Sons
Tipo: Artigo de Revista Científica
Publicado em //2015 EN
Relevância na Pesquisa
36.86%
AIM: To determine whether clonal diversity within E. faecalis affects biofilm formation when exposed to antimicrobial compounds found in endodontic medicaments and irrigants. METHODOLOGY: Five human isolates of E. faecalis were compared; biofilms were grown in microtitre trays in the presence of sodium hypochlorite, calcium hydroxide, chlorhexidine, tetracycline or clindamycin. Biofilms were quantified by staining with crystal violet and optical density determined with a microplate reader. Slime production (an amorphous extracellular matrix comprising polysaccharides, glycoproteins and glycolipids loosely attached to the cell surface) was determined qualitatively by growth on Congo red agar plates. Linear mixed models were used to examine whether medicaments affected biofilm growth of the isolates in the presence of the medicaments or irrigants. RESULTS: Overall, different endodontic antimicrobials significantly altered biofilm growth in E. faecalis isolates. Two E. faecalis isolates significantly (P < 0.0001) increased biofilm formation in the presence of tetracycline and one in the presence of NaOCl (P = 0.018). Qualitatively, slime production also varied between isolates and correlated with biofilm production. CONCLUSIONS: When subjected to sub-minimum inhibitory concentration (MIC) levels of antimicrobial compounds found in endodontic medicaments...

A poly-epsilon-caprolactone based biofilm carrier for nitrate removal from water

Rodrigues, A. L.; Machado, A.; Nobrega, J. M.; Albuquerque, Antonio; Brito, A. G.; Nogueira, Regina
Fonte: Springer Publicador: Springer
Tipo: Artigo de Revista Científica
Publicado em /03/2014 ENG
Relevância na Pesquisa
36.86%
Nitrate removal from water has been accomplished by heterotrophic biofilms using organic carbon as a source of reducing power. To overcome the natural limitation in organic carbon in water, a poly-epsilon-caprolactone based biofilm carrier that serves simultaneously as a biofilm carrier and as a source of organic carbon was developed and tested in the present work. The feasibility of the new biofilm carrier for nitrate removal from water was evaluated in a packed bed reactor. The combination of size and structure provided a carrier element having high surface area and void volume, 1,170 m(2)/m(3) and 67 %, respectively. A maximum denitrification rate of 4.4 mg N-NO3-/(L.h) (9.2 mg N-NO3-/(m(2).h)) was achieved in the packed bed reactor at 20 degrees C and pH 7.0. Main advantages of the biofilm carrier developed in the present work are its mechanical stability in water even after biofilm formation and controlled release of organic carbon by enzymatic reactions. The proposed biotechnology to remove nitrate from groundwater is robust and easy to operate.

Complete denture biofilm after brushing with specific denture paste, neutral soap and artificial saliva

Paranhos,Helena de Freitas Oliveira; Salles,Antônio Eduardo Sparça; Macedo,Leandro Dorigan de; Silva-Lovato,Cláudia Helena da; Pagnano,Valéria Oliveira; Watanabe,Evandro
Fonte: Fundação Odontológica de Ribeirão Preto Publicador: Fundação Odontológica de Ribeirão Preto
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/01/2013 EN
Relevância na Pesquisa
36.86%
This study compared the levels of biofilm in maxillary and mandibular complete dentures and evaluated the number of colony-forming units (cfu) of yeasts, after using auxiliary brushing agents and artificial saliva. Twenty-three denture wearers with hyposalivation and xerostomia were instructed to brush the dentures 3 times a day during 3 weeks with the following products: Corega Brite denture dentifrice, neutral liquid soap, Corega Brite combined with Oral Balance (artificial saliva) or tap water. For biofilm quantification, the internal surfaces of the dentures were disclosed, photographed and measured using a software. For microbiological analysis, the biofilm was scrapped off, and the harvested material was diluted, sown in CHROMagar™ Candida and incubated at 37°C for 48 h. Data were analyzed statistically by two-way ANOVA and Tukey's test (α=0.05). Mandibular dentures presented a mean biofilm percentage (µ=26.90 ± 21.10) significantly greater than the maxillary ones (µ=18.0 ± 15.0) (p<0.05). Brushing using Corega Brite combined with Oral Balance (µ=15.87 ± 18.47) was more effective (p<0.05) than using the denture dentifrice (µ=19.47 ± 17.24), neutral soap (µ=23.90 ± 18.63) or tap water (control; µ=32.50 ± 20.68). For the microbiological analysis...

Factores de adhesión de Rhizobium leguminosarum y su rol en la formación de biofilms; Adhesion factors from Rhizobium leguminosarum and their role on biofilm formation

Vozza, Nicolás Federico
Fonte: Facultad de Ciencias Exactas y Naturales. Universidad de Buenos Aires Publicador: Facultad de Ciencias Exactas y Naturales. Universidad de Buenos Aires
Tipo: info:eu-repo/semantics/doctoralThesis; tesis doctoral; info:eu-repo/semantics/publishedVersion Formato: application/pdf
Publicado em //2012 SPA
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Rhizobium leguminosarum es una α-proteobacteria que puede establecer simbiosis con ciertas leguminosas. La formación de un biofilm puede favorecer la persistencia en suelos y en la rizosfera y también contribuir a la competitividad para la infección de la leguminosa. En esta tesis se estudiaron factores importantes para la adhesión a diversos sustratos y la formación de biofilms. Uno de los factores estudiados fue la proteína de adhesión RapA1, secretada a través del sistema PrsDE. Se sobreexpresó RapA1 y se observó que esto produjo diversos fenotipos de superficie, incluido el aumento de adhesión a sustratos abióticos y la formación aumentada de biofilms in vitro. Se estudió la relación entre RapA1 y el exopolisacárido acídico (EPS) y el requerimiento del EPS y PrsDE para formar biofilms en flujo continuo. Se analizó la localización de RapA1 y de otras proteínas relacionadas y se estudiaron posibles mecanismos involucrados en la localización. Algunos estudios complementarios sobre el efecto de RapA1 sobre la superficie, efecto de expresión de otras Raps y regulación de genes relacionados con la adhesión fueron encarados de manera inicial. La interacción entre Polisacáridos de superficie y adhesinas proteicas resulta clave para la adhesión y formación de biofilms...

Efficacy of three denture brushes on biofilm removal from complete dentures

Fermandes, Roseana Aparecida Gomes; Lovato - Silva, Cláudia Helena; Paranhos, Helena de Freitas Oliveira; Ito, Izabel Yoko
Fonte: Universidade de São Paulo. Faculdade de Odontologia de Bauru Publicador: Universidade de São Paulo. Faculdade de Odontologia de Bauru
Tipo: info:eu-repo/semantics/article; info:eu-repo/semantics/publishedVersion; ; Formato: application/pdf
Publicado em 01/02/2007 ENG
Relevância na Pesquisa
36.86%
The aim of this study was to compare the efficacy of three denture brushes (Bitufo-B; Medic Denture-MD; Colgate-C) on biofilm removal from upper and lower dentures using a specific dentifrice (Corega Brite). The correlation between biofilm levels on the internal and external surfaces of the upper and lower dentures was also evaluated. A microbiological assay was performed to assess the growth of colony-formed units (cfu) of Candida yeasts on denture surface. Thirty-three patients were enrolled in a 10-week trial divided in two stages: 1 (control) - three daily water rinses within 1 week; 2 - three daily brushings within 3 weeks per tested brush. Internal (tissue) and external (right buccal flange) surfaces of the complete dentures were disclosed (neutral red 1%) and photographed. Total denture areas and disclosed biofilm areas were measured using Image Tool 3.00 software for biofilm quantification. Dentures were boxed with #7 wax and culture medium (CHROMagarTM Candida) was poured to reproduce the internal surface. Statistical analysis by Friedman's test showed significant difference (p;0.01). Analysis by the Correlation test showed higher r values (B=0.78; MD=0.8341, C=0.7362) for the lower dentures comparing the surfaces (internal and external) and higher r values (B=0.7861...