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Biofilm formation on intrauterine devices in patients with recurrent vulvovaginal candidiasis

AULER, Marcos E.; MORREIRA, Debora; RODRIGUES, Fabio F. O.; ABRAO, Mauricio S.; MARGARIDO, Paulo F. R.; MATSUMOTO, Flavia E.; SILVA, Eriques G.; SILVA, Bosco C. M.; SCHNEIDER, Rene P.; PAULA, Claudete R.
Fonte: TAYLOR & FRANCIS LTD; LONDON Publicador: TAYLOR & FRANCIS LTD; LONDON
Tipo: Artigo de Revista Científica
ENG
Relevância na Pesquisa
36.78%
A biofilm is a complex community of surface-associated cells enclosed in a polymer matrix. They attach to solid surfaces and their formation can be affected by growth conditions and co-infection with other pathogens. The presence of biofilm may protect the microorganisms from host defenses, as well as significantly reduce their susceptibility to antifungal agents. Pathogenic microbes can form biofilms on the inert surfaces of implanted devices such as catheters, prosthetic cardiac valves and intrauterine devices (IUDs). The present study was carried out to analyze the presence of biofilm on the surface of intrauterine devices in patients with recurrent vulvovaginal candidiasis, and to determine the susceptibility profile of the isolated yeasts to amphotericin B and fluconazole. Candida albicans was recovered from the IUDs and it was found to be susceptible to the antifungal agents when tested under planktonic growing conditions. These findings indicate the presence of the biofilm on the surface of the IUD as an important risk factor for recurrent vulvovaginal candidiasis.; FAPESP

Effects of the domestic use of a disclosing solution on the denture biofilm: a preliminary study

SOUZA, R. F. de; NASCIMENTO, C.; REGIS, R. R.; SILVA-LOVATO, C. H.; PARANHOS, H. F. O.
Fonte: WILEY-BLACKWELL PUBLISHING, INC Publicador: WILEY-BLACKWELL PUBLISHING, INC
Tipo: Artigo de Revista Científica
ENG
Relevância na Pesquisa
36.78%
To investigate the effect of the home use of a disclosing agent on the microbial composition of denture biofilm, by means of a cross-over randomized clinical trial. Two interventions were tested during 7 days each: (i) oral and denture hygiene instructions and (ii) instructions associated with the home use of a disclosing agent (1% neutral red). Eleven participants with visible biofilm deposits over their maxillary complete dentures were randomly assigned to one of the two sequences of interventions: (i) I followed by II, and (ii) II followed by I. A washout period of 7 days was established. After each intervention, samples of denture biofilm were evaluated by DNA checkerboard hybridization for the detection of Candida spp. and 17 bacterial species. Counts were low for all the tested species, and no significant difference was found between the tested interventions ( Wilcoxon test, P > 0.05). The home use of a disclosing agent does not remarkably change the composition of denture biofilm.; Fapesp[2006/56194-4]

Estratégias terapêuticas para inibir o crescimento de biofilme produzido por cepas multirresistentes de Pseudomonas aeruginosa representativas de clones e/ou genótipos de resistência endêmicos no Brasil.; Therapeutic strategies to inhibit the growth of biofilm produced by strains of multiresistant Pseudomonas aeruginosa representative of clones and/or exhibiting resistance genotypes endemic in Brazil.

Gonçalves, Rodrigo Cantamessa
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 10/02/2015 PT
Relevância na Pesquisa
36.78%
Pseudomonas aeruginosa é um patógeno multirresistente capaz de produzir um biofilme protetor contra antibacterianos (ATB). O presente estudo avaliou estratégias terapêuticas contra biofilmes de cepas multirresistentes de P. aeruginosa representativas de clones e/ou genótipos de resistência endêmicos no Brasil. Os biofilmes foram formados in vitro utilizando um modelo adaptado do MBEC Assay e as estratégias terapêuticas utilizaram bacteriófagos líticos, combinação de ATB e/ou uso de força iônica alta (meio FIA). A aplicação de bacteriófagos líticos (φSPM-1) e a combinação de Aztreonam (ATM) e Piperacilina/Tazobactam (PPT), não foram capazes de eliminar o biofilme. Biofilme formado em meio FIA possui CIM similar ao modelo planctônico, tanto para ATM (4 mg/mL) quanto para PPT (16 mg/mL). Ambos os ATB apresentaram CIM reduzida (inferior a 2 mg/mL) quando aplicados em conjunto com meio FIA. Dependendo da concentração de NaCl, a aplicação de meio FIA possui efeito bactericida sobre bactérias planctônicas e efeito bacteriostático sobre biofilmes já formados.; Multidrug-resistant Pseudomonas aeruginosa is a pathogen capable of producing a protective biofilm against antibiotics (ATB). The present study evaluated therapeutic strategies against biofilms of multidrug-resistant strains of P. aeruginosa representative of clones and/or exhibiting resistance genotypes endemic in Brazil. Biofilms were formed in vitro using an adapted model of MBEC Assay and the therapeutic strategies used lytic bacteriophages...

Antibacterial efficacy of intracanal medicaments on bacterial biofilm : a critical review

Estrela, Carlos; Sydney, Gilson Blitzkow; Figueiredo, Jose Antonio Poli de; Estrela, Cyntia Rodrigues de Araújo
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
36.78%
The purpose of this paper is to discuss critically the antibacterial efficacy of intracanal medicaments on bacterial biofilm. Longitudinal studies were evaluated by a systematic review of English-language articles retrieved from electronic biomedical journal databases (MEDLINE, EMBASE, CENTRAL) and handsearching records, using different matches of keywords for root canal biofilm, between 1966 and August 1st, 2007. The selected articles were identified from titles, abstracts and full-text articles by two independent reviewers, considering the tabulated inclusion and exclusion criteria. Disagreements were resolved by consensus. The search retrieved 91 related articles, of which 8.8% referred to in vivo studies demonstrating the lack of efficacy of endodontic therapy on bacterial biofilm. Intracanal medicaments were found to have a limited action against bacterial biofilm.

Análise transcricional de genes relacionados à formação de biofilme e virulência em cepas de Listerua Monocytogenes cultivadas em diferentes temperaturas; Transcriptional analysis of genes related to biofilm formation and virulence in Listeria monocytogenes strains grown at different temperatures

Pieta, Luiza
Fonte: Universidade Federal do Rio Grande do Sul Publicador: Universidade Federal do Rio Grande do Sul
Tipo: Dissertação Formato: application/pdf
POR
Relevância na Pesquisa
36.78%
Dentre as oito espécies do gênero Listeria, a única transmitida por alimentos, patogênica para humanos, é a Listeria monocytogenes. De grande preocupação para a indústria alimentícia, este microrganismo pode ser encontrado em diversas superfícies de plantas processadoras de alimentos, sendo capaz de se aderir e formar persistentes biofilmes. No presente trabalho, foi estudada a influência da concentração de glicose e do tempo de incubação na formação de biofilme por uma cepa de L. monocytogenes, sorotipo 1/2a, cultivada em três diferentes temperaturas, 7°C, 25°C e 37°C, através de planejamento experimental utilizando a Metodologia de Superfície de Resposta. As duas variáveis testadas, para os intervalos estudados, foram significativas (p<0,05) na formação de biofilme somente na temperatura de 37°C e, tanto concentrações de glicose tendendo a zero combinadas com tempos de incubação próximos a 26 h, como maiores concentrações de glicose combinadas com menores tempos de incubação, dentro da faixa de estudo aplicada, representaram boas condições para a formação de biofilme. Foi também realizada a análise transcricional de genes relacionados à formação de biofilme e virulência em duas cepas de L. monocytogenes...

Effect of calcium pre-rinse and fluoride dentifrice on remineralisation of artificially demineralised enamel and on the composition of the dental biofilm formed in situ

Magalhaes, Ana Carolina; de Almeida Furlani, Tatiana; de Moraes Italiani, Flavia; Iano, Flavia Godoy; Delbem, Alberto Carlos Botazzo; Buzalaf, Marilia Afonso Rabelo
Fonte: Elsevier B.V. Publicador: Elsevier B.V.
Tipo: Artigo de Revista Científica Formato: 1155-1160
ENG
Relevância na Pesquisa
36.78%
Objective: This in situ blind crossover study investigated the effect of calcium (Ca) rinse prior to the use fluoride (F) dentifrice on remineralisation of artificially demineralised enamel and on the composition of biofilm. Design: During four phases of 14 days, 10 volunteers wore appliances containing two artificially demineralised bovine enamel blocks. Three times a day, they rinsed with 10 mL, of Ca (150 mM) or placebo rinse (1 min). A slurry (1:3, w/v) of F (1030 ppm) or placebo dentifrice was dripped onto the blocks. During I min, the volunteers brushed their teeth with the respective dentifrice. The appliance was replaced into the mouth and the volunteers rinsed with water. The biofilm formed on the blocks was analysed for F and Ca. Enamel alterations were evaluated by the percentage of surface microhardness change (%SMHC), cross-sectional microhardness (% mineral volume) and alkali-soluble F analysis. Data were analysed by ANOVA (p < 0.05). Results: the use of the Ca pre-rinse before the F dentifrice produced a six- and four-fold increase in biofilm F and Ca concentrations, respectively. For enamel, the remineralisation was significantly improved by the Ca pre-rinse when compared to the other treatments. There was a significantly higher concentration of alkali-soluble F in enamel when the F dentifrice was used...

EM evaluation of bacterial biofilm and microorganisms on the apical external root surface of human teeth

Leonardo, Mário R; Rossi, Marcos A; Silva, Léa A B; Ito, Izabel Y; Bonifácio, Kleber C
Fonte: Universidade Estadual Paulista Publicador: Universidade Estadual Paulista
Tipo: Artigo de Revista Científica Formato: 815-818
ENG
Relevância na Pesquisa
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The aim of this study was to evaluate the presence of bacterial biofilm on the external surface of the root apex in teeth with pulp necrosis, with and without radiographically visible periapical lesions, and in teeth with a vital pulp. Twenty-one teeth were extracted, eight with pulp necrosis and periapical lesions, eight with pulp necrosis without radiographically visible periapical lesions, and five with a vital pulp. The roots were sectioned, and the root apexes (+/- 3 mm) were processed for scanning electron microscope evaluation. The surface of the apical root was evaluated for the presence of microorganisms, root resorption, and biofilm. There were no microorganisms on the apical root surface of either teeth with pulp vitality or with pulp necrosis with no radiographically visible periapical lesions. Microorganisms were always present in teeth with pulp necrosis and radiographically visible periapical lesions. These included cocci, bacilli, and filaments and the presence of an apical biofilm. Apical biofilm is clinically important because microbial biofilms are inherently resistant to antimicrobial agents and cannot be removed by biomechanical preparation alone. This may cause failure of endodontic treatment as a consequence of persistent infection.

Effect of brushing with conventional versus whitening dentifrices on surface roughness and biofilm formation of dental ceramics

Azevedo, Sarina Maciel Braga; Kantorski, Karla Zanini; Valandro, Luiz Felipe; Bottino, Marco Antonio; Pavanelli, Carlos Augusto
Fonte: Universidade Estadual Paulista Publicador: Universidade Estadual Paulista
Tipo: Artigo de Revista Científica
ENG
Relevância na Pesquisa
36.78%
The aim of this study was to evaluate the effect of conventional and whitening dentifrices on the weight loss, surface roughness, and early in situ biofilm formation on the surface of dental ceramics. Standardized feldspar ceramic specimens (Vita VM7 and Vita VM13) were submitted to the following experimental conditions: no brushing; brushing without a dentifrice; brushing with a conventional dentifrice; and brushing with a whitening dentifrice. A brushing machine was used to simulate brushing. The mass and surface roughness of all specimens from the test groups were evaluated prior to and after brushing. Ten participants used an oral device for eight hours to evaluate the biofilm formed in situ on the specimens. Scanning electron microscopy was used for qualitative and quantitative analysis of the biofilm. ANOVA and Tukey tests were used to analyze the results of weight loss, surface roughness, and presence of bacteria. A one-way Kruskal-Wallis test was used for bacterial colonization results. For both ceramics, brushing with a whitening dentifrice resulted in weight loss that was significantly greater when compared to brushing without a dentifrice or with a conventional dentifrice. Increased surface roughness was noticed on VM13 ceramic samples with both dentifrices...

Photodynamic inactivation of biofilm: Taking a lightly colored approach to stubborn infection

De Melo, Wanessa C.M.A.; Avci, Pinar; De Oliveira, Milene Nóbrega; Gupta, Asheesh; Vecchio, Daniela; Sadasivam, Magesh; Chandran, Rakkiyappan; Huang, Ying-Ying; Yin, Rui; Perussi, Livia R.; Tegos, George P.; Perussi, Janice R.; Dai, Tianhong; Hamblin, Mi
Fonte: Universidade Estadual Paulista Publicador: Universidade Estadual Paulista
Tipo: Revisão Formato: 669-693
ENG
Relevância na Pesquisa
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Microbial biofilms are responsible for a variety of microbial infections in different parts of the body, such as urinary tract infections, catheter infections, middle-ear infections, gingivitis, caries, periodontitis, orthopedic implants, and so on. The microbial biofilm cells have properties and gene expression patterns distinct from planktonic cells, including phenotypic variations in enzymic activity, cell wall composition and surface structure, which increase the resistance to antibiotics and other antimicrobial treatments. There is consequently an urgent need for new approaches to attack biofilm-associated microorganisms, and antimicrobial photodynamic therapy (aPDT) may be a promising candidate. aPDT involves the combination of a nontoxic dye and low-intensity visible light which, in the presence of oxygen, produces cytotoxic reactive oxygen species. It has been demonstrated that many biofilms are susceptible to aPDT, particularly in dental disease. This review will focus on aspects of aPDT that are designed to increase efficiency against biofilms modalities to enhance penetration of photosensitizer into biofilm, and a combination of aPDT with biofilm-disrupting agents. © 2013 Informa UK Ltd.

Dissection of the role of pili and type 2 and 3 secretion systems in adherence and biofilm formation of an atypical enteropathogenic escherichia coli strain

Hernandes, Rodrigo T.; De la Cruz, Miguel A.; Yamamoto, Denise; Girón, Jorge A.; Gomes, Tânia A.T.
Fonte: Universidade Estadual Paulista Publicador: Universidade Estadual Paulista
Tipo: Artigo de Revista Científica Formato: 3793-3802
ENG
Relevância na Pesquisa
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Atypical enteropathogenic Escherichia coli (aEPEC) strains are diarrheal pathogens that lack bundle-forming pilus production but possess the virulence-associated locus of enterocyte effacement. aEPEC strain 1551-2 produces localized adherence (LA) on HeLa cells; however, its isogenic intimin (eae) mutant produces a diffuse-adherence (DA) pattern. In this study, we aimed to identify the DA-associated adhesin of the 1551-2 eae mutant. Electron microscopy of 1551-2 identified rigid rod-like pili composed of an 18-kDa protein, which was identified as the major pilin subunit of type 1 pilus (T1P) by mass spectrometry analysis. Deletion of fimA in 1551-2 affected biofilm formation but had no effect on adherence properties. Analysis of secreted proteins in supernatants of this strain identified a 150-kDa protein corresponding to SslE, a type 2 secreted protein that was recently reported to be involved in biofilm formation of rabbit and human EPEC strains. However, neither adherence nor biofilm formation was affected in a 1551-2 sslE mutant. We then investigated the role of the EspA filament associated with the type 3 secretion system (T3SS) in DA by generating a double eae espA mutant. This strain was no longer adherent, strongly suggesting that the T3SS translocon is the DA adhesin. In agreement with these results...

Formação de biofilmes e produção de moléculas sinalizadoras de quorum sensing por cepas de Salmonellla spp. isoladas de processamento de frango; Biofilm formation and production of quorum sensing signaling molecules by strains of Salmonella spp. isolated from chicken processing

Maria Amelia de Jesus Piton
Fonte: Biblioteca Digital da Unicamp Publicador: Biblioteca Digital da Unicamp
Tipo: Tese de Doutorado Formato: application/pdf
Publicado em 03/12/2012 PT
Relevância na Pesquisa
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Apesar da implantação de ferramentas e programas de controle para redução da incidência de Salmonella spp. nas granjas e abatedouros avícolas, a prevalência deste patógeno na cadeia produtiva avícola ainda é representativa. A adesão dos micro-organismos à superfície de equipamentos utilizados no processamento de alimentos resulta em graves problemas, pois atua como fonte de contaminação. Estes agregados de células com altas densidades populacionais presentes na superfície podem produzir moléculas sinalizadoras de quorum sensing responsáveis pela expressão de características fenotípicas específicas, dentre elas substâncias envolvidas na formação de biofilme. Uma vez instalado o biofilme, a resistência desses organismos aumenta, dificultando a ação dos sanitizantes, comprometendo a qualidade dos alimentos, além de aumentar os riscos à saúde pública. Um total de 65 cepas de Salmonella, sendo 39 isoladas de carcaças e cortes de frango e 26 isoladas de amostras de granjas, foi caracterizado quanto aos sorotipos e resistência a 24 antimicrobianos. O sorotipo Enteritidis foi o predominante representando 67,7% das cepas, seguido do sorotipo Newport com 7,7%. Um total de 10 padrões de resistência foi identificado...

Composition and activity of a denitrifying biofilm along an anoxic RBC reactor

Teixeira, P.; Oliveira, Rosário
Fonte: Universidade do Minho Publicador: Universidade do Minho
Tipo: Conferência ou Objeto de Conferência
Publicado em //1999 ENG
Relevância na Pesquisa
36.78%
The variation of the biofilm characteristics of an anoxic rotating biological contactor, formed under a carbon/nitrogen ratio of 2, were studied. The biofilm activity was assessed in terms of the substrate removal ability and it showed a decrease along the reactor. Parameters as thickness, dry weight, density and specific components (proteins and polysaccharides) were also quantified. These properties were determined in biofilm portions from different parts of the RBC reactor. They show a different trend of variation along the bioreactor.

Changes in CoNS biofilm formation, composition, structure and antimicrobial resistance due to growth in sub-inhibitory concentrations of dicloxacillin

Cerca, Nuno; Martins, Silvia; Sillankorva, Sanna; Pier, Gerald B.; Oliveira, Rosário; Azeredo, Joana
Fonte: IWA publishing Publicador: IWA publishing
Tipo: Conferência ou Objeto de Conferência
Publicado em //2004 ENG
Relevância na Pesquisa
36.78%
Many studies have demonstrated that low concentrations of antibiotics can inhibit microbial adherence to medical-device surfaces. However, little is known about the changes that might occur in bacterial physiology of biofilms formed under sub-inhibitory (sub-MIC) concentrations of antibiotics. In this study, biofilms of two coagulase negative staphylococci (CoNS) species were formed with and without the presence of subMIC concentrations of dicloxacillin and changes in the ability to produce biofilms as well as in the composition of biofilm matrix were evaluated. Biofilms formed in the presence of dicloxacillin developed less amount of biomass and exhibited a different composition of the biofilm matrix. Bacterial physiological alterations triggered by biofilm formation under subMIC concentrations of antibiotics were also evaluated. The results showed that bacteria surface characteristics, like hydrophobicity and elemental composition as well as the expression of PNAG molecules were affected. Additionally, an increase in resistance to several antibiotics was observed in biofilm cells formed in the presence of dicloxacillin.

Drinking water biofilm monitoring by Propella™ and flow cell bioreactors under different operating conditions

Simões, Lúcia C.; Simões, M.; Vieira, M. J.
Fonte: Universidade do Minho. Departamento de Engenharia Biológica Publicador: Universidade do Minho. Departamento de Engenharia Biológica
Tipo: Conferência ou Objeto de Conferência
Publicado em 04/09/2008 ENG
Relevância na Pesquisa
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Monitoring of biofilm subjected to different process conditions was performed using two distinct bioreactors, Propella™ and flow cell system. Biofilms were grown on polyvinyl chloride (PVC) and stainless steel (SS) coupons under laminar (Reynolds number of 2000) and turbulent (Reynolds number of 11000) flow. The parameters analyzed were culturable cells, using R2A, and total bacteria, which were assessed using a DNA-binding stain coupled with epifluorescence microscopy. The impact of the different operating conditions in the studied parameters was established after the biofilms reached the steady-state. It was found that the biofilm steady-state was achieved 3 d after the starting of operating conditions for turbulent flow and for both bioreactors and adhesion surfaces. Under laminar flow it was only achieved 6 d after. The number of total bacteria was invariably higher than the culturable cells. The number of total and culturable bacteria in turbulent flow-generated biofilms were similar in both bioreactors, regardless the adhesion surface tested. Under laminar flow, the Propella™ bioreactor allowed the formation of steady-state biofilms with a higher number of total and culturable bacteria than those from the flow cell system. Comparing the effect of the flow regime on biofilm accumulation...

Synthesis and degradation of poly-β-hydroxybutyrate in a sequencing batch biofilm reactor

Nogueira, R.; Alves, Cláudia; Matos, Maria F.; Brito, A. G.
Fonte: Elsevier Publicador: Elsevier
Tipo: Artigo de Revista Científica
Publicado em /04/2009 ENG
Relevância na Pesquisa
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The aim of this work was the study of poly-β-hydroxybutyrate (PHB) formation and degradation in a sequencing batch biofilm reactor (SBBR). The SBBR was operated in cycles comprising three individual phases: mixed fill, aeration and draw. A synthetic substrate solution with acetate and ammonium was used. PHB was formed during the aeration phase immediately after acetate depletion, and was subsequently consumed for biomass growth, owing to the high oxygen concentration in the reactor. It was observed a combination of suspended and biofilm growth in the SBBR with predominance of the fixed form of biomass (506 Cmmol and 2102 Cmmol, respectively). Maximum PHB fraction of suspended biomass (0.13 Cmol/Cmol) was considerably higher than that of biofilm (0.01 Cmol/Cmol). This may possibly be explained by a combination of two factors: lower mass transfer limitation of acetate and higher fraction of heterotrophs in suspended biomass compared to the ones of biofilm.; Fundação para a Ciência e a Tecnologia (FCT) - PRAXIS XXI BD/19687/99; Fundo Europeu de Desenvolvimento Regional (FEDER) - POCI 2010 (POCI/AMB/61155/2004)

Troubleshooting of filamentous bulking using biofilm reactors

Matos, M.; Pereira, M. A.; Nicolau, Ana; Rodrigues, A. L.; Brito, A. G.; Nogueira, R.
Fonte: Universidade do Minho Publicador: Universidade do Minho
Tipo: Conferência ou Objeto de Conferência
Publicado em //2010 ENG
Relevância na Pesquisa
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The present work aims to evaluate filamentous bulking control in systems combining suspended biomass with biofilm growth. For this study, four sequencing batch reactors (SBR)fed with an easy biodegradable substrate (acetate) were operated without (SBR1) and with support for biofilm growth [5 % (SBR2), 10 % (SBR3) and 20 % (SBR4) of the reactor volume]. The results demonstrated an overabundance of a filamentous fungi-like microorganism in the SBR operating just with suspended biomass. The incorporation of an optimized amount of support for biofilm growth (10 % and 20 %) seemed to suppress the overgrowth of this filamentous microorganism probably due to the combined effect of a decreased biomass loading rate and the physical cut or breakdown of filaments induced by particle-to-particle collisions. Besides the observed differences in terms of the filamentous fungi-like microorganism, the incorporation of a support material for biofilm growth was also found to induce increasing differences in the bacterial community structure as the concentration of support increased in the SBR.

The anti-adherence effect of Lippia sidoides Cham: extract against microorganisms of dental biofilm

Albuquerque,A.C.L.; Pereira,M.S.V.; Silva,D.F.; Pereira,L.F.; Viana,F.A.C.; Higino,J.S.; Barbosa,M.R.V.
Fonte: Sociedade Brasileira de Plantas Medicinais Publicador: Sociedade Brasileira de Plantas Medicinais
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/01/2013 EN
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Most illnesses affecting the oral cavity are proven to have infectious origin. Several categories of chemical agents have been used in the chemical control of dental biofilm through strategies that aim at reducing bacterial adhesion and inhibiting the growth and the proliferation of microorganisms on the tooth surface. The use of plants in folk medicine and in Dentistry, as well as the spread of successful cases, has led to scientific exploration, resulting in chemical-pharmacological knowledge of thousands of plants. The present study aimed to evaluate the anti-adherence activity of Lippia sidoides Cham., comparing the results with those of 0.12% chlorhexidine by means of an in vitro simulation of dental biofilm. The studied bacterial strains were Streptococcus mutans, Streptococcus sanguinis and Lactobacillus casei, main responsible for the biofilm adherence. The studied extract was effective in inhibiting the adherence of Streptococcus mutans up to a concentration of 1:16, compared to Chlorhexidine. Lippia sidoides Cham extract showed anti-adherence effect on the major microorganisms responsible for dental biofilm consolidation.

Bacterial exopolysaccharide and biofilm formation stimulate chickpea growth and soil aggregation under salt stress

Qurashi,Aisha Waheed; Sabri,Anjum Nasim
Fonte: Sociedade Brasileira de Microbiologia Publicador: Sociedade Brasileira de Microbiologia
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/09/2012 EN
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To compensate for stress imposed by salinity, biofilm formation and exopolysaccharide production are significant strategies of salt tolerant bacteria to assist metabolism. We hypothesized that two previously isolated salt-tolerant strains Halomonas variabilis (HT1) and Planococcus rifietoensis (RT4) have an ability to improve plant growth, These strains can form biofilm and accumulate exopolysacharides at increasing salt stress. These results showed that bacteria might be involved in developing microbial communities under salt stress and helpful in colonizing of bacterial strains to plant roots and soil particles. Eventually, it can add to the plant growth and soil structure. We investigated the comparative effect of exopolysacharide and biofilm formation in two bacterial strains Halomonas variabilis (HT1) and Planococcus rifietoensis (RT4) in response to varying salt stress. We found that biofilm formation and exopolysaccharide accumulation increased at higher salinity. To check the effect of bacterial inoculation on the plant (Cicer arietinum Var. CM-98) growth and soil aggregation, pot experiment was conducted by growing seedlings under salt stress. Inoculation of both strains increased plant growth at elevated salt stress. Weight of soil aggregates attached with roots and present in soil were added at higher salt concentrations compared to untreated controls. Soil aggregation was higher at plant roots under salinity. These results suggest the feasibility of using above strains in improving plant growth and soil fertility under salinity.

The efficacy of immediate versus delayed antibiotic administration on bacterial growth and biofilm production of selected strains of uropathogenic Escherichia coli and Pseudomonas aeruginosa

Gandee,Leah; Hsieh,Jer-Tsong; Sperandio,Vanessa; Moreira,Cristiano G.; Lai,Chih-Ho; Zimmern,Philippe E.
Fonte: Sociedade Brasileira de Urologia Publicador: Sociedade Brasileira de Urologia
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/02/2015 EN
Relevância na Pesquisa
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Purpose The treatment of urinary tract infections (UTI) with antibiotics is commonly used, but recurrence and antibiotic resistance have been growing and concerning clinicians. We studied whether the rapid onset of a protective biofilm may be responsible for the lack of effectiveness of antibiotics against selected bacteria. Materials and Methods Two established uropathogenic Escherichia coli strains, UTI89 and CFT073, and two Pseudomonas aeruginosa strains, PA01 and Boston-41501, were studied to establish a reliable biofilm formation process. Bacterial growth (BG) was determined by optical density at 600 nm (OD 600) using a spectrophotometer, while biofilm formation (BF) using crystal violet staining was measured at OD 550. Next, these bacterial strains were treated with clinically relevant antibiotics, ciprofloxacin HCl (200 ng/mL and 2 μg/mL), nitrofurantoin (20 μg/mL and 40 μg/mL) and ampicillin (50 μg/mL) at time points of 0 (T0) or after 6 hours of culture (T6). All measurements, including controls (bacteria -1% DMSO), were done in triplicates and repeated three times for consistency. Results The tested antibiotics effectively inhibited both BG and BF when administered at T0 for UPEC strains, but not when the antibiotic administration started 6 hours later. For Pseudomonas strains...

Antibacterial efficacy of intracanal medicaments on bacterial biofilm: a critical review

Estrela,Carlos; Sydney,Gilson Blitzkow; Figueiredo,José Antonio Poli; Estrela,Cyntia Rodrigues de Araújo
Fonte: Faculdade De Odontologia De Bauru - USP Publicador: Faculdade De Odontologia De Bauru - USP
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/02/2009 EN
Relevância na Pesquisa
36.78%
The purpose of this paper is to discuss critically the antibacterial efficacy of intracanal medicaments on bacterial biofilm. Longitudinal studies were evaluated by a systematic review of English-language articles retrieved from electronic biomedical journal databases (MEDLINE, EMBASE, CENTRAL) and handsearching records, using different matches of keywords for root canal biofilm, between 1966 and August 1st, 2007. The selected articles were identified from titles, abstracts and full-text articles by two independent reviewers, considering the tabulated inclusion and exclusion criteria. Disagreements were resolved by consensus. The search retrieved 91 related articles, of which 8.8% referred to in vivo studies demonstrating the lack of efficacy of endodontic therapy on bacterial biofilm. Intracanal medicaments were found to have a limited action against bacterial biofilm.