Letteratura scientifica selezionata sul tema "Biofilm"
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Articoli di riviste sul tema "Biofilm"
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Kesel, Sara, Stefan Grumbein, Ina Gümperlein, Marwa Tallawi, Anna-Kristina Marel, Oliver Lieleg e Madeleine Opitz. "Direct Comparison of Physical Properties of Bacillus subtilis NCIB 3610 and B-1 Biofilms". Applied and Environmental Microbiology 82, n. 8 (12 febbraio 2016): 2424–32. http://dx.doi.org/10.1128/aem.03957-15.
Testo completoAbstract (sommario):
ABSTRACTMany bacteria form surface-attached communities known as biofilms. Due to the extreme resistance of these bacterial biofilms to antibiotics and mechanical stresses, biofilms are of growing interest not only in microbiology but also in medicine and industry. Previous studies have determined the extracellular polymeric substances present in the matrix of biofilms formed byBacillus subtilisNCIB 3610. However, studies on the physical properties of biofilms formed by this strain are just emerging. In particular, quantitative data on the contributions of biofilm matrix biopolymers to these physical properties are lacking. Here, we quantitatively investigated three physical properties ofB. subtilisNCIB 3610 biofilms: the surface roughness and stiffness and the bulk viscoelasticity of these biofilms. We show how specific biomolecules constituting the biofilm matrix formed by this strain contribute to those biofilm properties. In particular, we demonstrate that the surface roughness and surface elasticity of 1-day-old NCIB 3610 biofilms are strongly affected by the surface layer protein BslA. For a second strain,B. subtilisB-1, which forms biofilms containing mainly γ-polyglutamate, we found significantly different physical biofilm properties that are also differently affected by the commonly used antibacterial agent ethanol. We show that B-1 biofilms are protected from ethanol-induced changes in the biofilm's stiffness and that this protective effect can be transferred to NCIB 3610 biofilms by the sole addition of γ-polyglutamate to growing NCIB 3610 biofilms. Together, our results demonstrate the importance of specific biofilm matrix components for the distinct physical properties ofB. subtilisbiofilms.
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Ferris, Ryan A., Patrick M. McCue, Grace I. Borlee, Kristen D. Loncar, Margo L. Hennet e Bradley R. Borlee. "In VitroEfficacy of Nonantibiotic Treatments on Biofilm Disruption of Gram-Negative Pathogens and anIn VivoModel of Infectious Endometritis Utilizing Isolates from the Equine Uterus". Journal of Clinical Microbiology 54, n. 3 (30 dicembre 2015): 631–39. http://dx.doi.org/10.1128/jcm.02861-15.
Testo completoAbstract (sommario):
In this study, we evaluated the ability of the equine clinical treatmentsN-acetylcysteine, EDTA, and hydrogen peroxide to disruptin vitrobiofilms and kill equine reproductive pathogens (Escherichia coli,Pseudomonas aeruginosa, orKlebsiella pneumoniae) isolated from clinical cases.N-acetylcysteine (3.3%) decreased biofilm biomass and killed bacteria within the biofilms ofE. coliisolates. The CFU of recoverableP. aeruginosaandK. pneumoniaeisolates were decreased, but the biofilm biomass was unchanged. Exposure to hydrogen peroxide (1%) decreased the biofilm biomass and reduced the CFU ofE. coliisolates,K. pneumoniaeisolates were observed to have a reduction in CFU, and minimal effects were observed forP. aeruginosaisolates. Chelating agents (EDTA formulations) reducedE. coliCFU but were ineffective at disrupting preformed biofilms or decreasing the CFU ofP. aeruginosaandK. pneumoniaewithin a biofilm. No single nonantibiotic treatment commonly used in equine veterinary practice was able to reduce the CFU and biofilm biomass of all three Gram-negative species of bacteria evaluated. Anin vivoequine model of infectious endometritis was also developed to monitor biofilm formation, utilizing bioluminescence imaging with equineP. aeruginosaisolates from this study. Following infection, the endometrial surface contained focal areas of bacterial growth encased in a strongly adherent “biofilm-like” matrix, suggesting that biofilms are present during clinical cases of infectious equine endometritis. Our results indicate that Gram-negative bacteria isolated from the equine uterus are capable of producing a biofilmin vitro, andP. aeruginosais capable of producing biofilm-like materialin vivo.
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Bhatta, Mahesh Prakash, Asmita Sapkota, Pushpa Subedi, Sunita Baniya Chhetri, Dhaka Raj Pant, Mukund Joshi, Santosh Pandit e Dipendra Raj Pandeya. "Biofilm Formation by Uropathogens and Their Susceptibility Towards Antimicrobial Therapy". Medical Journal of Shree Birendra Hospital 18, n. 1 (26 febbraio 2019): 13–22. http://dx.doi.org/10.3126/mjsbh.v18i1.20189.
Testo completoAbstract (sommario):
Introduction: Urinary tract infection (UTI) is the most common health care associated infection caused by various pathogenic bacteria. Biofilms are communities of bacteria that are held together by exopolymeric substances that protect against the antimicrobial therapy and other environmental assaults. The aim of this study was to estimate the prevalence of biofilm forming bacteria in Nepalese population and to study the emergence of antimicrobial resistance among biofilm producing bacteria in comparison to non-biofilm producing bacteria.
Methods: A total of 785 clean-caught-mid-stream urine samples were collected. After isolation and identification of uropathogens, they were further processed for detection of biofilm formation by two methods (Congo Red Agar method and Tissue Culture Plate method) as well as for antibiotic sensitivity test.
Results: Out of total collected samples, 12.74% were found to be associated with UTI, among them 67% were Escherichia coli, 10% were Klebsiella spp, 7% were Pseudomonas spp, 6% were Staphyloccous aureus, 4% were Enterobacter spp, 3% were Proteus spp, 2% were Citrobacter spp and remaining 1% was Staphylococcus saprophyticus. Among isolated organisms, the ratio of bioflim positive organism to bioflim negative organism was found to be 9:11. Nitrofurantoin, Tobramycin, Chloramphenicol, Amikacin and Imipenem were found to be significantly more sensitive in biofilm negative bacteria as compared to biofilm positive bacteria with p values of 0.000, 0.001, 0.000, 0.000 and 0.001.
Conclusions: The prevalence rate of multidrug resistance in bacterial uropathogens was higher in biofilm producers as compared to non-biofilm producers. Biofilm forming characteristic of bacteria make them more resistant to antibiotics.
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Conwell, Michael, James S. G. Dooley e Patrick J. Naughton. "A Novel Biofilm Model System to Visualise Conjugal Transfer of Vancomycin Resistance by Environmental Enterococci". Microorganisms 9, n. 4 (9 aprile 2021): 789. http://dx.doi.org/10.3390/microorganisms9040789.
Testo completoAbstract (sommario):
Enterococci and biofilm-associated infections are a growing problem worldwide, given the rise in antibiotic resistance in environmental and clinical settings. The increasing incidence of antibiotic resistance and its propagation potential within enterococcal biofilm is a concern. This requires a deeper understanding of how enterococcal biofilm develops, and how antibiotic resistance transfer takes place in these biofilms. Enterococcal biofilm assays, incorporating the study of antibiotic resistance transfer, require a system which can accommodate non-destructive, real-time experimentation. We adapted a Gene Frame® combined with fluorescence microscopy as a novel non-destructive platform to study the conjugal transfer of vancomycin resistance in an established enterococcal biofilm.A multi-purpose fluorescent in situ hybridisation (FISH) probe, in a novel application, allowed the identification of low copy number mobile elements in the biofilm. Furthermore, a Hoechst stain and ENU 1470 FISH probe identified Enterococcus faecium transconjugants by excluding Enterococcus faecalis MF06036 donors. Biofilm created with a rifampicin resistant E. faecalis (MW01105Rif) recipient had a transfer efficiency of 2.01 × 10−3; double that of the biofilm primarily created by the donor (E. faecalis MF06036). Conjugation in the mixed enterococcal biofilm was triple the efficiency of donor biofilm. Double antibiotic treatment plus lysozyme combined with live/dead imaging provided fluorescent micrographs identifying de novo enterococcal vancomycin resistant transconjugants inside the biofilm. This is a model system for the further study of antibiotic resistance transfer events in enterococci. Biofilms promote the survival of enterococci and reduce the effectiveness of drug treatment in clinical settings, hence giving enterococci an advantage. Enterococci growing in biofilms exchange traits by means of horizontal gene transfer, but currently available models make study difficult. This work goes some way to providing a non-destructive, molecular imaging-based model system for the detection of antibiotic resistance gene transfer in enterococci.
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Lesmana, Muhamad Arfan, Dahliatul Qosimah e Sri Murwani. "Detection of Staphylococcus aureus Biofilm from Subclinical Mastitis Milk". Veterinary Biomedical and Clinical Journal 1, n. 1 (1 gennaio 2019): 19–25. http://dx.doi.org/10.21776/ub.vetbioclinj.2019.001.01.3.
Testo completoAbstract (sommario):
One of S.aureus's virulence factors is biofilm formation. When biofilms are formed, the bacteria will undergo phenotypic changes that require higher concentrations of antibiotics to inhibit proliferation. Phenotypic changes will lead to increase the production of extracellular matrix and multilayered colonies as well as decrease of metabolic rates, multiplication and polymicrobial colonization resulting in recurrent infection in the host and difficulty being treated with antibiotics due to resistance. The aim of this research was to know the formation of bacterial biofim by slime and quantitative by microplate titer method. The research method was qualitative descriptive using 27 samples of Staphylococcus aureus with characterized from mastitis infected milk. The bacteria were grown on CRA (Congo Red Agar) media to observe the slime biofilm through bacteria black colony followed by MicrotiterPlate method with 570nm wave lenght. The results showed that 27 samples of Staphylococcus aureus which positive to form slime biofilm were 10 samples and continued to microtiter plate showed 3 positive samples of biofilm. The conclusions of this study, Staphylococcus aureus in subclinical mastitis milk samples were positive to form biofilms.
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van Loosdrecht, M. C. M., D. Eikelboom, A. Gjaltema, A. Mulder, L. Tijhuis e J. J. Heijnen. "Biofilm structures". Water Science and Technology 32, n. 8 (1 ottobre 1995): 35–43. http://dx.doi.org/10.2166/wst.1995.0258.
Testo completoAbstract (sommario):
The influences of reactor conditions (substrate loading rate and shear) and microbial characteristics (yield and growth rate) on the structure of biofilms is discussed. Based on research on the formation of biofilms in Biofilm Airlift Suspension (BAS) reactors a hypothesis is postulated that the ratio between biofilm surface loading and shear rate determines the biofilm structure. When shear forces are relatively high only a patchy biofilm will develop, whereas at low shear rates the biofilm becomes highly heterogeneous with many pores and protuberances. In case of a right balance smooth and stable biofilms can be obtained. A hypothesis for the evolution of biofilm structures as a function of process conditions is formulated.
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Wang, Xiaoling, Mudong Hao e Guoqing Wang. "Numerical simulation of wrinkle morphology formation and the evolution of different Bacillus subtilis biofilms". Water Science and Technology 73, n. 3 (10 ottobre 2015): 527–34. http://dx.doi.org/10.2166/wst.2015.486.
Testo completoAbstract (sommario):
Wrinkle morphology is a distinctive phenomenon observed in mature biofilms that are produced by a great number of bacteria. The wrinkle pattern depends on the mechanical properties of the agar substrate and the biofilm itself, governed by the extracellular matrix (ECM). Here we study the macroscopic structures and the evolution of Bacillus subtilis biofilm wrinkles using the commercial finite element software ABAQUS. A mechanical model and simulation are set up to analyze and evaluate bacteria biofilm's wrinkle characteristics. We uncover the wrinkle formation mechanism and enumerate the quantitative relationship between wrinkle structure and mechanical properties of biofilm and its substrate. Our work can be used to modify the wrinkle pattern and control the biofilm size.
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Lewandowski, Z., H. Beyenal e D. Stookey. "Reproducibility of biofilm processes and the meaning of steady state in biofilm reactors". Water Science and Technology 49, n. 11-12 (1 giugno 2004): 359–64. http://dx.doi.org/10.2166/wst.2004.0880.
Testo completoAbstract (sommario):
The need for reproducing biofilm processes is undisputable - the quality of biofilm research depends on this reproducibility. However, as many biofilm researchers know, long-term biofilm processes are notoriously difficult to reproduce. To avoid problems related to biofilm reproducibility two strategies are used: (1) to study very young biofilms that have accumulated for a few hours to a few days only, and (2) to run biofilm experiments only once. The first approach trades reproducibility for relevance because natural biofilms are usually older, often much older than a few days. This approach can be applied to answer questions relevant to initial events of biofilm formation but not questions relevant to long-term biofilm accumulation. The second approach conceals the problem of biofilm reproducibility. To assure reproducibility of biofilm processes, we methodically followed a procedure for growing biofilms in terms of microbial makeup, media composition, temperature, surface preparation, etc. Despite all this effort the reproducibility of our results for long term growth is unimpressive. Consequently, the question had to be asked: Are biofilm processes reproducible? The experiments described in this paper address this question. Biofilms grown in two identical and identically operated biofilm reactors had comparable structure only until the first sloughing event. After that, biofilms had different patterns of accumulation.
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Hengzhuang, Wang, Hong Wu, Oana Ciofu, Zhijun Song e Niels Høiby. "In VivoPharmacokinetics/Pharmacodynamics of Colistin and Imipenem in Pseudomonas aeruginosa Biofilm Infection". Antimicrobial Agents and Chemotherapy 56, n. 5 (21 febbraio 2012): 2683–90. http://dx.doi.org/10.1128/aac.06486-11.
Testo completoAbstract (sommario):
ABSTRACTManyPseudomonas aeruginosaisolates from the airways of patients with cystic fibrosis (CF) are sensitive to antibiotics in susceptibility testing, but eradication of the infection is difficult. The main reason is the biofilm formation in the airways of patients with CF. The pharmacokinetics (PKs) and pharmacodynamics (PDs) of antimicrobials can reliably be used to predict whether antimicrobial regimens will achieve the maximum bactericidal effect against infections. Unfortunately, however, most PK/PD studies of antimicrobials have been done on planktonic cells and very few PK/PD studies have been done on biofilms, partly due to the lack of suitable modelsin vivo. In the present study, a biofilm lung infection model was developed to provide an objective and quantitative evaluation of the PK/PD profile of antimicrobials. Killing curves were set up to detect the antimicrobial kinetics on planktonic and biofilmP. aeruginosacellsin vivo. Colistin showed concentration-dependent killing, while imipenem showed time-dependent killing on both planktonic and biofilmP. aeruginosacellsin vivo. The parameter best correlated to the elimination of bacteria in lung by colistin was the area under the curve (AUC) versus MIC (AUC/MIC) for planktonic cells or the AUC versus minimal biofilm inhibitory concentration (MBIC; AUC/MBIC) for biofilm cells. The best-correlated parameter for imipenem was the time that the drug concentration was above the MIC for planktonic cells (TMIC) or time that the drug concentration was above the MBIC (TMBIC) for biofilm cells. However, the AUC/MIC of imipenem showed a better correlation with the efficacy of imipenem for biofilm infections (R2= 0.89) than planktonic cell infections (R2= 0.38). The postantibiotic effect (PAE) of colistin and imipenem was shorter in biofilm infections than planktonic cell infections in this model.
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Silva, Vanessa, Luciana Almeida, Vânia Gaio, Nuno Cerca, Vera Manageiro, Manuela Caniça, José L. Capelo, Gilberto Igrejas e Patrícia Poeta. "Biofilm Formation of Multidrug-Resistant MRSA Strains Isolated from Different Types of Human Infections". Pathogens 10, n. 8 (30 luglio 2021): 970. http://dx.doi.org/10.3390/pathogens10080970.
Testo completoAbstract (sommario):
Methicillin-resistant Staphylococcus aureus (MRSA) is one of the main pathogens causing chronic infections, mainly due to its capacity to form biofilms. However, the mechanisms underlying the biofilm formation of MRSA strains from different types of human infections are not fully understood. MRSA strains isolated from distinct human infections were characterized aiming to determine their biofilm-forming capacity, the biofilm resistance to conventional antibiotics and the prevalence of biofilm-related genes, including, icaA, icaB, icaC, icaD, fnbA, fnbB, clfA, clfB, cna, eno, ebpS, fib and bbp. Eighty-three clinical MRSA strains recovered from bacteremia episodes, osteomyelitis and diabetic foot ulcers were used. The biofilm-forming capacity was evaluated by the microtiter biofilm assay and the biofilm structure was analyzed via confocal scanning laser microscopy. The antimicrobial susceptibility of 24-h-old biofilms was assessed against three antibiotics and the biomass reduction was measured. The metabolic activity of biofilms was evaluated by the XTT assay. The presence of biofilm-related genes was investigated by whole-genome sequencing and by PCR. Despite different intensities, all strains showed the capacity to form biofilms. Most strains had also a large number of biofilm-related genes. However, strains isolated from osteomyelitis showed a lower capacity to form biofilms and also a lower prevalence of biofilm-associated genes. There was a significant reduction in the biofilm biomass of some strains tested against antibiotics. Our results provide important information on the biofilm-forming capacity of clinical MRSA strains, which may be essential to understand the influence of different types of infections on biofilm production and chronic infections.
Tesi sul tema "Biofilm"
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Guilhen, Cyril. "Caractérisations transcriptionnelle et phénotypique de bactéries dispersées de biofilm à Klebsiella pneumoniae". Thesis, Université Clermont Auvergne (2017-2020), 2017. http://www.theses.fr/2017CLFAS015.
Testo completoAbstract (sommario):
Le développement d’un biofilm est un processus complexe qui se décline en plusieurs étapes. L’adhésion initiale des bactéries au support est suivie de la formation de microcolonies, puis de la synthèse d’une matrice extracellulaire qui englobe les bactéries donnant lieu à un biofilm mature. La dernière étape, sans doute la moins bien décrite jusqu’à présent, consiste en la dispersion du biofilm. Ce phénomène, contrôlé génétiquement, est déclenché en réponse à de nombreux signaux physiques et chimiques, telles que la température, la disponibilité en nutriments ou l’accumulation de molécules signal (peptides autoinducteurs du quorum sensing, monoxyde d’azote...). Les bactéries sessiles synthétisent alors une panoplie d’effecteurs qui permettent à certaines cellules de quitter le biofilm pour coloniser de nouveaux environnements. Dans le cadre d’infections liées aux biofilms, ce processus de dispersion est un mécanisme clé permettant la libération dans l’organisme de bactéries à partir de biofilms souvent constitués sur des matériels médicaux invasifs. Cependant, la physiologie des cellules ainsi dispersées reste relativement méconnue mais doit probablement jouer un rôle majeur dans la colonisation ultérieure et l’infection chez l’hôte. L’objectif de ce travail était de caractériser au niveau transcriptionnel et phénotypique les cellules dispersées de biofilms formés par le pathogène opportuniste Klebsiella pneumoniae, et ceci comparativement aux formes planctoniques et sessiles. Une analyse transcriptionnelle a été réalisée à partir des formes planctoniques (exponentielles et stationnaires), sessiles et dispersées, en combinant un modèle expérimental de culture en flux (flow-cell) et un séquençage global des ARN (RNAseq). Les données obtenues ont indiqué que les bactéries dispersées affichaient un profil transcriptionnel unique et distinct des autres formes bactériennes. De plus, cette analyse transcriptionnelle des formes planctoniques, sessiles et dispersées de biofilm a permis de dresser une carte exhaustive du transcriptome de K. pneumoniae au cours des différentes phases de croissance et de dégager des gènes « signatures » de chacune d’elle. Le profil transcriptionnel unique des bactéries dispersées suggère qu’elles possèdent une physiologie spécifique leur permettant de coloniser efficacement de nouveaux environnements. L’analyse des propriétés des bactéries dispersées a ainsi constitué la deuxième partie du projet, en se focalisant sur les mécanismes clés dans la physiopathologie des infections nosocomiales à K. pneumoniae, à savoir les capacités d’adhésion, de colonisation et de virulence. Le profilage phénotypique a montré que les bactéries dispersées de biofilm colonisaient significativement mieux les surfaces biotiques et abiotiques que des bactéries planctoniques. Cette capacité de colonisation accrue ne s’expliquait ni par une meilleure adhésion initiale des bactéries, ni par une activité métabolique supérieure, mais par une capacité des bactéries dispersées à former très rapidement des microcolonies. À ceci s’ajoutait un pouvoir pathogène augmenté des bactéries dispersées comparativement à la forme planctonique, avec notamment une meilleure résistance à l’activité bactéricide des macrophages. La mise au point d’un modèle murin d’infection pulmonaire adapté a été initiée ; il permettra d’analyser la virulence de ces bactéries dispersées. L’ensemble des résultats indique que les bactéries dispersées de biofilm se placent dans un état unique du cycle de vie bactérien, en étant transcriptionnellement différentes des autres formes bactériennes, et avec des propriétés mixtes, se rapprochant à la fois de la forme planctonique (activité métabolique et taux de croissance élevée) et de la forme sessile (fort pouvoir de colonisation et meilleure résistance à la phagocytose). L’ensemble de ces propriétés confère certainement un rôle déterminant dans le déclenchement d’infections liées aux biofilmsBiofilm development is a complex process involving several steps. The bacterial adhesion to the surface is followed by formation of microcolonies and synthesis of extracellular matrix, which encased bacteria giving rise to mature biofilm. The last step, probably the most poorly described, corresponds to biofilm dispersal. This process is genetically controlled and triggered in response to a wide range of physical and chemical signals, such as temperature, nutrients availability or the accumulation of signal molecules (quorum sensing autoinducers, nitric oxide...). In response to these signals, sessile bacteria synthesize various effectors, which allow a subset of cells to leave the biofilm and colonize new environments. In the context of biofilm-related infections, the biofilm dispersal process is a key mechanism for the release of bacteria from biofilms formed on invasive medicals devices. Little is known about the properties of the resulting biofilm-dispersed bacteria, but they probably play a major role in the subsequent colonization and infection processes within the host. The objective of this work was to characterize the transcriptome and the phenotype of biofilm-dispersed bacteria of the opportunist pathogen Klebsiella pneumoniae comparatively to the planktonic and sessile forms. A transcriptional analysis was carried out using planktonic (both exponential and stationary forms), sessile and biofilm-dispersed bacteria by combining a flow-cell experimental model with global RNA sequencing (RNAseq). Results indicated that biofilm- dispersed bacteria displayed a unique transcriptional pattern in the bacterial lifecycle. Furthermore, analysis of the whole transcriptome of planktonic, sessile and biofilm-dispersed bacteria allowed to emphasize the transcriptional changes occurring in the course of K. pneumoniae lifestyle transitions and to select transcriptional signatures genes for the five bacterial physiological states. The unique transcriptional pattern of biofilm-dispersed bacteria suggests that they display specific physiological characteristics required to colonize new environments. The second part of this work consisted in analyzing the properties of biofilm-dispersed bacteria, by focusing on key mechanisms involved in the physiopathology of K. pneumoniae: adhesion, colonization and virulence. Phenotypic profiling showed that biofilm-dispersed bacteria colonized significantly more biotic and abiotic surfaces than their planktonic counterparts. This increased colonization capacity was not due to an enhanced adhesion or a higher metabolic activity but rather to the intrinsic capacity of the biofilm-dispersed bacteria to form rapidly microcolonies. Besides, biofilm-dispersed bacteria were more pathogenic than their planktonic counterparts showing a better resistance to the bactericidal activity of macrophages. The development of a murine pulmonary infection model is in progress and will enable to assess the virulence of biofilm-dispersed bacteria. Our results indicate that biofilm-dispersed bacteria are placed in a unique state in the bacterial lifecycle, being transcriptionally different from other bacterial forms, and with mixed properties, approaching both the planktonic form (elevated metabolic activity and growth rate) and the sessile form (strong colonization power and high resistance to phagocytosis). These properties certainly play a decisive role in the initiation of biofilm-related infections
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Zamataro, Claudia Bianchi. "Dentifricio de baixa concentração de fluoreto : efeito anticarie e mecanismos envolvidos". [s.n.], 2008. http://repositorio.unicamp.br/jspui/handle/REPOSIP/289527.
Testo completoAbstract (sommario):
Orientador: Livia Maria Andalo TenutaDissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Odontologia de Piracicaba
Made available in DSpace on 2018-08-11T10:53:13Z (GMT). No. of bitstreams: 1 Zamataro_ClaudiaBianchi_M.pdf: 2650038 bytes, checksum: 6be1cd9f989e8bbd7776d722dc3d8f62 (MD5) Previous issue date: 2008
Resumo: A eficiência anticárie dos dentifrícios fluoretados contendo 1000-1500 µg F/g está bem estabelecida, porém eles têm sido considerados fator de risco para fluorose dental. Para reduzir esse risco, dentifrícios contendo baixa concentração de fluoreto (F) (500-550 µg F/g) têm sido recomendados, mas sua eficiência anticárie ainda não foi demonstrada. Assim, o objetivo deste trabalho foi: 1. comparar a disponibilidade de F na saliva após utilização de dentifrício de baixa concentração de F (BC, 500 µg F/g, NaF), ou dentifrício de concentração convencional (CC, 1100 µg F/g, NaF), seguida ou não de enxágüe; e 2: avaliar in situ o potencial anticariogênico desses dentifrícios, estudando o efeito do F disponível no biofilme dental após a escovação, associado ou não aos produtos formados no esmalte pelo tratamento com os dentifrícios. Em ambos os estudos, foi empregado um delineamento cruzado e duplo cego. No estudo 1, amostras de saliva não estimulada de 5 voluntários foram coletadas antes e imediatamente após a escovação e nos tempos 1, 2, 3, 4, 5, 10, 15, 20, 30, 45 e 60 min após a escovação com BC ou CC, seguida ou não de enxágüe. A área sob a curva da concentração de F na saliva versus tempo foi calculada para determinar a biodisponibilidade de F salivar. Esta foi reduzida em 2,5 x pelo enxágüe pósescovação (p<0,05) e foi semelhante quando BC foi utilizado sem enxágüe e CC foi seguido de enxágüe (p>0,05). No estudo 2, doze voluntários realizaram escovação com dentifrícios contendo concentrações de F distintas (placebo (P) ¿ controle negativo, CC ou BC) e utilizaram um dispositivo palatino contendo blocos de esmalte bovino, previamente tratados ou não com suspensão do respectivo dentifrício. Os blocos foram cobertos com uma placa teste de S. mutans IB 1600 e após 30 min in situ, a placa foi coletada e a concentração de F no fluido foi determinada através de técnica microanalítica com eletrodo íon específico. Um bochecho com sacarose foi realizado como desafio cariogênico e após 45 min os blocos remanescentes e a placa teste foram coletados para avaliação, respectivamente, da perda mineral (simulando o efeito de diferentes espessuras de placa) e da concentração de F no fluido. O pré-tratamento dos blocos de esmalte com os dentifrícios fluoretados isoladamente não impediu a perda mineral em relação ao controle (p>0,05), mas causou aumento na concentração de F no fluido da placa (p<0,05). A escovação com os dentifrícios fluoretados aumentou a concentração de F no fluido da placa, sendo encontrada diferença significativa entre BC e CC (p<0,05), além de uma menor perda mineral em relação ao controle (p<0,05). Adicionalmente, embora a perda mineral tenha sido semelhante para BC e CC na simulação de espessura de placa de até 0,5 mm, ela foi maior para BC na placa mais espessa (1 a 1,5 mm) (p<0,05). Os resultados sugerem que o dentifrício de concentração convencional é mais efetivo do que o de baixa concentração na inibição da perda mineral. Adicionalmente, deve-se estimular o enxágüe da boca após o uso do dentifrício de concentração convencional por crianças de pequena idade
Abstract: The anticaries efficiency of fluoride (F) dentifrices containing 1000-1500 µg F/g is well established, but they are considered a risk factor to dental fluorosis. In order to reduce this risk, low-F concentration dentifrices (500-550 µg F/g) have been recommended, but their anticaries efficiency has not been demonstrated. Thus, this study aimed to: 1. compare salivary F availability after brushing with low- F concentration (LC, 500 µg F/g, NaF) or conventional F concentration (CC, 1100 µg F/g, NaF) dentifrices, followed or not by a water rinse and 2: evaluate in situ the anticaries potential of these dentifrices, studying the anticaries effect of F available on the dental biofilm after brushing, associated or not to F products formed on enamel by F dentifrice application was evaluated. In both studies, a crossover, double blind design was used. In study 1, samples of non-stimulated saliva from 5 volunteers were collected before and immediately after brushing with LC or CC, followed or not by a rinse, and after 1, 2, 3, 4, 5, 10, 15, 20, 30, 45 and 60 min. The area under the curve of salivary F concentration versus time was calculated to determine F bioavailability in saliva. F salivary bioavailability was reduced 2.5 X by the post-brushing rinse (p<0.05) and it was similar when LC was used without rinsing and CC was used followed by a rinse (p>0.05). In study 2, twelve volunteers brushed with dentifrices containing distinct F concentrations (placebo (P) ¿ negative control, LC or CC) and used a palatal appliance containing bovine enamel blocks previously treated or not with a slurry of assigned dentifrice. The blocks were covered with a test plaque from S. mutans IB 1600 and after 30 min in situ, F concentration in the fluid of plaque was assessed. A sucrose rinse was performed as a cariogenic challenge and after 45 min the remaining blocks and plaque test were removed to evaluate, respectively, mineral loss (as a function of plaque thickness) and F concentration in plaque fluid. The isolated effect of the pretreatment of enamel blocks with F dentifrices did not reduced mineral loss when compared to the control (p>0.05), but resulted in higher F concentration in the plaque fluid (p<0.05). Brushing with F dentifrices increased F concentration in the plaque fluid, which was significantly different between LC and CC (p<0.05), and resulted in lower mineral loss when compared to the control (p<0.05). Additionally, although LC and CC did not differ when mineral loss was evaluated on a plaque thickness simulation of up to 0.5 mm, CC was more efficient than LC at thicker plaque (1 to 1.5 mm) (p<0.05). The results suggest that conventional F concentration dentifrice is more efficient than the low-F one in the inhibition of mineral loss. Additionally, post-brushing rinse should be recommended after the use of conventional F concentration dentifrices by young children
Mestrado
Cariologia
Mestre em Odontologia
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Kesel, Sara [Verfasser], e Madeleine [Akademischer Betreuer] Opitz. "Contribution of biofilm matrix components to physical properties of Bacillus subtilis biofilms at all phases of biofilm-formation / Sara Kesel ; Betreuer: Madeleine Opitz". München : Universitätsbibliothek der Ludwig-Maximilians-Universität, 2020. http://d-nb.info/1230754709/34.
Testo completo
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Kowalska, Karolina. "Formation of biofilm in Pseudomonas aeruginosa : molecular characterisation of the macromolecular complex Pel". Thesis, Aix-Marseille 2, 2011. http://www.theses.fr/2011AIX22003.
Testo completoAbstract (sommario):
Pseudomonas aeruginosa est une bactérie pathogène opportuniste qui peut développer deux modes d’infection. Les infections aigües sont associées à la production et à la sécrétion de toxines qui peuvent avoir un effet cytotoxique, alors que dans le contexte d’une infection chronique la bactérie a tendance à s’établir sous la forme d’un biofilm. Un biofilm est une population de microorganismes organisée en une communauté et attachée sur une surface. Cette surface peut être biotique ou abiotique. Les biofilms bactériens ont des caractéristiques intrinsèques qui les rendent plus résistants à des conditions environnementales difficiles (pH, oxygène, UV, flux, etc…). Dans le cadre d’une infection l’établissement du biofilm résulte aussi en une population bactérienne difficile à éliminer par le système immunitaire mais également résistante aux antibiotiques. Des déterminants moléculaires majeurs qui interviennent dans la formation du biofilm sont le flagelle, les pili de type IV et les fimbriae Cup pour l’attachement, ou bien encore les exopolysaccharides qui sont avec l’ADN des composants essentiels de la matrice extracellulaire du biofilm qui englobe la population bactérienne. Chez P. aeuginosa, si l’alginate est le polysaccharide majeur, il a été montré que des souches non-mucoides forment également des biofilms et que dans ce contexte la synthèse et la sécrétion du polysaccharide majeur de la matrice sont dépendantes des gènes pel. Mon travail a consisté dans l’étude de l’organisation structurale du système Pel et le contrôle de son activitéPseudomonas aeruginosa is a human opportunistic pathogen, and in the course of an infection can develop two lifestyles. One of them is involved in secretion of toxins and results in acute infection, and the other one causes chronic infections and is characterized by formation of a biofilm. A biofilm is a highly organized bacterial population, organized as a complex community that is attached to a surface. Bacterial biofilm shows higher resistance to different enviromental factors including physical factors, antimicrobials or host immune response. Major components taking part in biofilm formation are flagella, type IV pili, cup fimbriae as well as exopolysaccharides. The latter provides a protective matrix for the biofilm, together with proteins and DNA. In non-mucoid strains the major exopolysaccharide of biofilm matrix is synthetised and secreted by pel gene cluster. My work concentrates on the structural organisation of Pel polysaccharide secretion machinery, regulation of its activity as well as detailed characterisation of the Pel polysaccharide itself
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Toda, Carina [UNESP]. "Avaliação da atividade antimicrobiana de um reembasador resiliente combinado a um polímero antimicrobiano sobre a formação de bio-filme". Universidade Estadual Paulista (UNESP), 2012. http://hdl.handle.net/11449/110834.
Testo completoAbstract (sommario):
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000792872.pdf: 571447 bytes, checksum: 3bae358d477e471a159de61135729477 (MD5)Este estudo avaliou a atividade antimicrobiana de um reembasador resiliente Coe Soft® (RRCS) combinado ao polímero antimicrobiano poli (2 tert-butilaminoetil) metacrilato (PTBAEMA) sobre formação de biofilme de Staphyloccocus aureus, Streptococcus mutans e Candida albicans. Espécimes circulares (15mm x 3mm) do RRCS foram confeccionados (n=27), esterilizados, divididos em três grupos de acordo com as concentrações de PTBAEMA a 0% (controle), 10% e 25% e individualmente inoculados em tubos de falcon contendo 5mL de caldo RPMI para os fungos, TSB para S. aureus e BHI para S. mutans e mantidos em overnight a 37ºC em incubadora com agitação orbital a 75rpm, sendo o S. mutans em microaerofilia. Após a inoculação dos espécimes seguiu-se a formação e maturação do biofilme a 37ºC sob agitação orbital a 75rpm. Em seguida cada espécime foi transferido para tubos contendo PBS e diluições seriadas foram realizadas. Alíquotas dessas diluições foram semeadas em placas de Petri e incubadas a 37ºC por 48h. Os dados obtidos foram transformados em log (UFC+1)/mL, considerando-se α=0,05. Os resultados demonstraram que o grupo contendo 25% de PTBAEMA inibiu completamente a formação de biofilme de S. aureus e S. mutans. Uma redução significativa na contagem de S. aureus e S. mutans (Kruskal- Wallis e Dunn; p=0,001) para o grupo contendo 10% de PTBAEMA foi observada quando comparada aos valores encontrados nos respectivos grupos controle. Para C. albicans não foi encontrada diferença significante entre grupos contendo PTBAEMA e o grupo controle (ANOVA; p>0,05). Conclui-se que os RRCS contendo 10% e 25% de PTBAEMA inibiram a formação de biofilme de S. aureus e S. mutans. Entretanto não teve efeito significante na formação de biofilme de C. albicans.
This study evaluated the antimicrobial activity of the resilient reliner Coe Soft ® (RRCS) combined with antimicrobial polymer poly (2-tert butylaminoethyl) methacrylate (PTBAEMA) on Staphylococcus aureus, Streptococcus mutans and Candida albicans biofilm formation. RRCS circular specimens were prepared (n=27), sterilized, divided into three groups according to PTBAEMA concentrations of 0% (control), 10% and 25% and inoculated into individual falcon tubes containing 5 mL of RPMI broth for fungi, TSB for S. aureus and BHI for S. mutans and kept overnight at 37°C with orbital shaking incubator at 75rpm, and S. mutans in microaerophilic. The specimens’ inoculations were followed by biofilm formation and its maturation at 37°C under orbital shaking at 75rpm. After that, each sample was transferred to tubes containing PBS and serial dilutions were performed. Aliquots of these dilutions were plated in Petri dishes and incubated at 37°C for 48h. The data were transformed into log (CFU +1)/mL, considering α = 0.05. The results showed that the group containing 25% of PTBAEMA inhibited completely biofilm formation of S. aureus and S. mutans. A significant reduction in counts of S. aureus and S. mutans (Kruskal- Wallis and Dunn; p = 0.001) were found in group containing 10% of PTBAEMA when compared to the values in the corresponding control groups. C. albicans had no significant differences between groups containing PTBAEMA and the control group (ANOVA; p> 0.05). It is concluded that the RRCS containing 10% and 25% PTBAEMA inhibited the biofilmformation of S. aureus and S. mutans. However, no significant effect was found on C. albicans biofilm formation.
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Senatore, Marcela Andrea Duran Haun 1974. "Avaliação da eficiencia de um esterilizador a plasma na inativação de Pseudomonas fluorescens". [s.n.], 2004. http://repositorio.unicamp.br/jspui/handle/REPOSIP/254838.
Testo completoAbstract (sommario):
Orientador: Marcelo CristianiniDissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia de Alimentos
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Resumo: Um dos problemas que enfrenta a indústria de laticínios é a recontaminação do leite decorrente da formação de biofilmes em tanques de armazenamento e trocadores de calor. A tecnologia de esterilização de materiais por gás plasma tem sido utilizada com sucesso na esterilização de instrumentos cirúrgicos, oftálmicos e dentários. Os objetivos deste trabalho foram avaliar a eficiência de um sistema de esterilização a gás plasma sob células de Pseudomonas fluorescens aderidas em placas de aço inoxidável utilizando o leite como substrato. Foram avaliadas as variáveis tempo de pré plasma, tempo de exposição ao plasma e potência do mesmo na remoção do biofilme. As placas de aço inoxidável com a bactéria aderida foram submetidas a um tratamento com gás plasma, que foi formado a partir de um produto comercial composto por ácido peracético, peróxido de hidrogênio e ácido acético. Dois sistemas modelo foram utilizados para simular a formação de biofilmes de Pseudomonas fluorescens, um dinâmico e outro estático, simulando trocadores de calor e tanques de armazenamento, respectivamente. Através do modelo estático foi possível obter contagens acima de 105 UFC por placa de aço inoxidável, mesmo após três ciclos de lavagem das placas em água estéril sob agitação. Foi observado um efeito positivo na inativação de P. fluorescens em função do tempo de pré-plasma do sanificante. Exposições acima de 7 minutos foram capazes de produzir reduções superiores a dois ciclos logarítmicos na inativação do microrganismo. Através de um planejamento experimental fatorial 23 foi demosntrado que as variáveis tempo de pré-plasma, tempo de exposição ao plasma e potência do plasma apresentaram efeitos positivos na inativação de Pseudomonas fluorescens. O tempo de exposição (min.) apresentou o maior efeito na destruição da bactéria; mas sendo um pouco superior à potência do plasma (w)
Abstract: One of the problems that food industry is facing is the milk recontamination through biofims formation on storage tanks and heat exchanger. The technology of sterilization for materials through gas plasma has been used with succesfull for cirurgycal, ophathalmic and dentistry equipment. The goals of this work was to evaluate the efficiency of a gas plasma sterilization system on Pseudomonas fluorescens cells adhered on stainless steel plates using milk as substrate. Time of pre plasma, plasma exposition and potency (Watts) were evaluated as independent variables on cell destruction. The stainless steel plates were submitted to gas plasma treatment originated from a commercial product composed of peracetic acid, hydrogen peroxide and acetic acid. Two model systems were used to simulate a biofilm formation of Pseudomonas fluorescens, one dynamic and one static, in order to simulate heat exchangers and storage tanks, respectively. Through static model it was possible to get counts over 105 UFC/plate after washing three times using sterile water under stirring conditions. It was observed a positive effect on P. fluorescens inactivation by pre-plasma in a time dependent way. Expositions over seven minutes were capable to produce reductions higher than two logarithmic cycles on microorganism inactivation. A 23 factorial design indicated that the pre-plasma time, time exposition and potency showed positive effects on Pseudomonas fluorescens inactivation. Time exposition (min) was the most effective variable on bacteria destruction, being a little higher than plasma potency (w)
Mestrado
Mestre em Tecnologia de Alimentos
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Al-Fattani, Mohammed A. A. "Role of the biofilm matrix in resistance of Candida biofilms to antifungal agents". Thesis, University of Glasgow, 2007. http://theses.gla.ac.uk/4076/.
Testo completoAbstract (sommario):
The aim of this project was to investigate the possible role of the biofilm matrix as a barrier to drug diffusion in Candida biofilms and in mixed species fungal-bacterial biofilms. The penetration of antifungal agents through single- and mixed-species biofilms containing Candida was investigated using a novel filter disk bioassay. Fluconazole permeated all single-species Candida biofilms more rapidly than flucytosine. Drug penetration was more extensive with C. albicans than with the other species and the rates of diffusion of either drug through biofilms of three strains of C. albicans were similar. In all cases, after 3 to 6h the drug concentration at the distal edge of the biofilm was very high (many times the MIC). Nevertheless, drug penetration failed to produce complete killing of biofilm cells. These results indicate that poor antifungal penetration is not a major drug resistance mechanism for Candida biofilms under these conditions. It has been reported that the production of extracellular matrix by Candida biofilms growing under static incubation conditions is relatively minimal, but increases dramatically when developing biofilms are subjected to a liquid flow. In this study, Candida biofilms were grown under flow conditions in a modified Robbins device (MRD). Biofilms of C. albicans grown in the MRD produced more matrix material than those grown statically, and were significantly more resistant (P<0.001) to amphotericin B. Biofilms of C. tropicalis synthesized large amounts of matrix material even when grown statically, and such biofilms were completely resistant to both amphotericin B and fluconazole. Mixed-species biofilms of C. albicans and S. epidermidis RP62A, when grown statically or in the MRD, were also completely resistant to amphotericin B and fluconazole. Mixed-species biofilms of C. albicans and S. epidermidis M7, on the other hand, were completely drug resistant only when grown under flow conditions. Overall, these findings demonstrate that the matrix can make a significant contribution to drug resistance in Candida biofilms, especially under conditions similar to those found in catheter infections in vivo, and that the composition of the matrix material is an important determinant in resistance.
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Saur, Thibaut. "Structuration morphologique et microbiologique des biofilms multi-espèces : de l’adhésion au biofilm mature". Thesis, Montpellier 2, 2014. http://www.theses.fr/2014MON20174/document.
Testo completoAbstract (sommario):
Les biofilms constituent un mode de vie microbien extrêmement répandu, aussi bien en milieu naturel que dans les environnements anthropisés. Dans ce dernier cas, les structures morphologique et microbiologique du biofilm vont conditionner son impact sur le système, que cet impact lui soit bénéfique ou préjudiciable. L'objectif de cette thèse est d'approfondir notre connaissance des phénomènes de structuration du biofilm afin, à terme, d'optimiser les performances de procédé. Afin de représenter au mieux les conditions industrielles, des régimes d'écoulement turbulents et des consortia microbiens complexes ont été utilisés. Une première partie se focalise sur l'impact des forces de cisaillement sur l'adhésion microbienne. Les résultats démontrent un changement progressif de la flore bactérienne fixée et de sa distribution spatiale. Dans un second temps, le projet s'est intéressé aux étapes de développement du biofilm et ont permis d'identifier un effet mémoire du biofilm mature. Il s'agit d'une conservation des structures morphologique et microbiologique au cours du temps en dépit d'un changement de régime hydrodynamique. Enfin la dernière partie a consisté en la mise au point d'une méthode de quantification des prédateurs mobiles dans les biofilms. Ces prédateurs participent à la structuration du biofilm et leur quantification peut s'avérer utile dans le contexte de l'épuration des eauxBiofilms are a biological mode of life widely spread in both natural and engineered environments. In the last case, whether the biofilm is beneficial or detrimental for the process under consideration, both morphology and microbial community of the biofilm determine its impact. The objective of this thesis is to deepen our knowledge of biofilm structuring and, as a further goal, optimize a given process. Turbulent flows and multi-species consortia were used in order to better mimic industrial conditions. The first part of the project focused on the impact of shear stress on microbial adhesion. Results have demonstrated a gradual shift in bacterial communities with shear and a change in the spatial distribution of adhered microorganisms. Secondly, the work dealt with biofilm development. A memory effect, defined as the conservation of initial morphological and microbiological features despite a change in the environmental conditions, has been observed. Finally, a method for quantification of moving predators in mature biofilms has been developed. These predators actively shape the biofilm and their quantification is valuable, especially for wastewater treatment
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Cruz, Sergio Eduardo Braga da. "Análise biomolecular de comunidades microbianas subgengivais associadas às periodontites crônica e agressiva generalizadas". [s.n.], 2010. http://repositorio.unicamp.br/jspui/handle/REPOSIP/288640.
Testo completoAbstract (sommario):
Orientadores: Reginaldo Bruno Gonçalves, Daniel SaitoTese (doutorado) - Universidade Estadual de Campinas, Faculdade de Odontologia de Piracicaba
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Resumo: Há um consenso que outros micro-organismos além de Aggregatibacter actinomycetemcomitans (Aa), Porphyromonas gingivalis (Pg), Tannerella forsythia (Tf) e Treponema denticola (Td) estariam correlacionados às periodontites, inclusive algumas espécies ainda não identificadas. Nosso objetivo foi estudar as microbiotas subgengivais de indivíduos com periodontite crônica generalizada (PCG) e periodontite agressiva generalizada (PAG) para avaliar diferenças entre suas microbiotas. MATERIAL E MÉTODOS-Foram selecionados 15 indivíduos com PCG e 14 com PAG. Coletou-se amostra do biofilme subgengival de uma bolsa periodontal profunda (BP-PS ? 7mm) e uma moderada (BM - PS entre 5 e 6 mm) de cada indivíduo. Foi preparado e analisado, por meio de DGGE, o perfil bacteriano entre os grupos. A similaridade e a análise de cluster do padrão de UTO's foram verificadas utilizando-se coeficiente de Jaccard e a construção do dendrograma realizada por UPGMA. Realizou-se também análise clonal direta de 10 amostras de BP de cada grupo e as sequências foram agrupadas em táxons com similaridade >97%. RESULTADOS-DGGE - No perfil de DGGE foi observada uma tendência para a formação de grupos em BP, mas não em BM, com a presença de dois grupos maiores e distintos de oito indivíduos tanto para PCG como PAG, com variação de similaridade intra-grupo entre 53,6-68,4% e 50,2-64,7%, respectivamente. Análise clonal - Foram identificados 109 táxons conhecidos a partir de 987 clones. Ao todo 44 gêneros bacterianos, 28 gêneros comuns aos dois grupos, nove que se apresentaram apenas para PCG e sete para PAG. Entre os dois grupos foram observados 34 táxons comuns, sendo 42 específicos para PAG e 37 para PCG. A espécie Tf foi detectada em 90% dos indivíduos com PCG e 80% com PAG, Pg foi detectada em 70% com PCG e 50% com PAG e Td foi detectada em 40% com PCG e 30% PAG. A espécie Aa foi encontrada em somente 20% de PCG e 30% de PAG. A espécie Filifactor alocis foi observada em altas taxas e prevalência em PCG (58 clones, 90%) e PAG (91 clones, 90%). As espécies encontradas exclusivamente por grupo com prevalência acima de dois pacientes foram: PCG: Treponema lecithinolyticum, Selenomonas dianae, Prevotella pleuritidis, Dialister pneumosintes; e para PAG: Fusobacterium nucleatum ss vincentii, Veillonella parvula, Peptococcus sp. Cepa GEA8, Streptococcus gordonii, Lautropia mirabilis, Gemella sanguinis, Afipia broomeae. Para os filotipos, PCG: Peptostreptococcaceae sp. Clone-MCE10_174, Fusobacterium sp. C-I035, Veillonellaceae sp. C-JS031; PAG: Peptostreptococcaceae sp. C-PUS9170, Treponema sp. CG093. Apesar de não haver exclusividade entre grupos, é de nota os filotipos Synergistes sp. clone W028 (80% e 60%) e o clone D084 (70% e 10%) em PCG e PAG, respectivamente. O filotipo Bacteroidetes sp. AU126 foi encontrado tanto em PCG (60%) como PAG (30%). CONCLUSÃO - O presente trabalho demonstrou por meio de DGGE uma tendência a um perfil microbiano comum entre a maioria das amostras estudadas, entretanto, sem seu completo delineamento como dois grupos distintos microbiologicamente. A análise clonal, apesar de algumas espécies específicas entre grupos, demonstrou pequenas diferenças, sem, entretanto, delinear grupos microbiologicamente específicos.
Abstract: There is an agreement that not only the already known periodontopathogens, Aggregatibacter actinomycetemcomitans (Aa), Porphyromonas gingivalis (Pg), Tannerella forsythia (Tf) and Treponema denticola (Td) would be involved in periodontitis, but also some others micro-organisms not-yet-identified. The scope of this study is to compare the subgingival microbiota in generalized chronic periodontitis (GCP) or generalized aggressive periodontitis (GAP) subjects. MATERIAL AND METHODS - 15 subjects with GCP and 14 with GAP were enrolled. One subgingival biofilm sample from a periodontal deep pocket (DP) with PD ? 7mm and one from a moderate pocket (MP) with PD from 5 to 6 mm were harvested from each subject. The microbial profiles (OTU's) were compared between groups by DGGE and the similarity OTU profile was analyzed by Jaccard coefficient and the dendrogram and cluster analyses were made by UPGMA. The direct clonal analysis of the 16SrDNA from 10 samples of each group from DP was made. The sequences were grouped in clusters of taxa with > 97% similarity. RESULTS - DGGE - It was observed in the profile a tendency for eight subjects from each group to assemble as clusters in the DP, but not for the MP samples, with similarities between 53.6-68.4% (GCP) and 50.2-64.7% (GAP). Clonal analyses - One-hundred-and-nine already recognized taxa were obtained from 987 clones. From a total of 44 bacterial genera, 28 were common for both groups; nine were exclusive to PCG and seven to PAG subjects. It was found 34 common taxa between GCP and GAP, 37 were specific for GCP and 42 for GAP. The Tf species was found in 90% from GCP subjects and 80% from GAP subjects, Pg was found in 70% from GCP and in 50% from GAP and Td was detected in 40% from GCP and 30% from GAP. The Aa species were found in only 20% GCP subjects and in 30% from GAP. Filifactor alocis species were detected in high prevalence in both GCP (58 clones, 90%) and PAG (91 clones, 90%). The species which were detected exclusively in each group, with 20% prevalence or more were, for GCP: Treponema lecithinolyticum, Selenomonas dianae, Prevotella pleuritidis, Dialister pneumosintes; and GAP: Fusobacterium nucleatum ss vincentii, Veillonella parvula, Peptococcus sp. Cepa GEA8, Streptococcus gordonii, Lautropia mirabilis, Gemella sanguinis, Afipia broomeae. In relation to phylotypes, PCG: Peptostreptococcaceae sp. Clone-MCE10_174, Fusobacterium sp. C-I035, Veillonellaceae sp. C-JS031; PAG: Peptostreptococcaceae sp. C-PUS9170, Treponema sp. C-G093. Despite not been found exclusively for neither GCP nor GAP, the phylotypes Synergistes sp. clone W028 (80% e 60%) and clone D084 (70% e 10%) had a notable presence in GCP and GAP, respectively. The phylotype Bacteroidetes sp. AU126 was found in GCP (60%) and GAP (30%) groups. CONCLUSION - The present study demonstrated by DGGE a slight tendency to the clustering of the microbial profile of some GCP and GAP subjects, although these were not well delineated. The clonal analyses showed some differences, but also could not show GCP and GAP as microbiologic distinct profiles.
Doutorado
Microbiologia e Imunologia
Doutor em Biologia Buco-Dental
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Galvão, Lívia Câmara de Carvalho 1985. "Avaliação da atividade antimicrobiana de óleos essenciais contra microrganismos do grupo mutans e determinação da atividade antiproliferativa". [s.n.], 2012. http://repositorio.unicamp.br/jspui/handle/REPOSIP/288527.
Testo completoAbstract (sommario):
Orientadores: Pedro Luiz Rosalen, Marta Cristina Teixeira DuarteDissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Odontologia de Piracicaba
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Resumo: O objetivo desse trabalho foi avaliar a atividade antimicrobiana, in vitro, de óleos essenciais e frações dos óleos de melhor atividade, contra microrganismos do grupo mutans em estado planctônico. Além disso, os biofilmes de Streptococcus mutans foram submetidos às frações ativas e os óleos de melhor atividade e frações ativas foram avaliados quanto à sua citotoxicidade e caracterizados quimicamente. Para isso, vinte óleos essenciais (OE) foram obtidos por hidrodestilação a partir de plantas pertencentes ao banco de germoplasmas da Coleção de Plantas Medicinais e Aromáticas (CPMA/CPQBA/UNICAMP). Estes OE foram avaliados quanto à sua atividade antimicrobiana por meio dos ensaios: concentrações inibitória (CIM) e bactericida mínima (CBM) contra Streptococcus mutans UA159. Controles positivo (clorexidina 0,12 %) e negativo (propilenoglicol 6,12 % e 25 %) também foram testados...Observação: O resumo, na íntegra, poderá ser visualizado no texto completo da tese digital
Abstract: The aim of this study was to evaluate the in vitro antimicrobial activity of essential oils (EO) and fractions from highest activity EO against planktonic cells of mutans streptococci. Besides, the biofilms formed by this microorganism were submitted to active fractions and the higher activity EO and active fractions were evaluated regarding their citotoxicity and chemically characterized. For this, twenty essentinal oils were obtained from plants of the "Collectio of Medicinal and Aromatic Plants" (CPMA, CPQBA/UNICAMP), germplasm bank by hydrodistillation. These EO were evaluated by antimicrobial assays: minimum inhibitory (MIC) and bactericidal (MBC) concentrations against Streptococcus mutans UA159. Positive (chlorhexidine 0.12%) and negative (propylene glycol 6.12 % and 25%) controls were also tested...Note: The complete abstract is available with the full electronic document
Mestrado
Farmacologia, Anestesiologia e Terapeutica
Mestre em Odontologia
Libri sul tema "Biofilm"
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Bjarnsholt, Thomas, Peter Østrup Jensen, Claus Moser e Niels Høiby, a cura di. Biofilm Infections. New York, NY: Springer New York, 2011. http://dx.doi.org/10.1007/978-1-4419-6084-9.
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Flemming, Hans-Curt, Jost Wingender e Ulrich Szewzyk, a cura di. Biofilm Highlights. Berlin, Heidelberg: Springer Berlin Heidelberg, 2011. http://dx.doi.org/10.1007/978-3-642-19940-0.
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Federation, Water Environment. Biofilm reactors. Alexandria, Va: WEF Press, 2011.
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Szewzyk, Ulrich, Hans-C. Flemming e Jost Wingender. Biofilm highlights. Heidelberg: Springer, 2011.
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Costerton, J. William, a cura di. The Biofilm Primer. Berlin, Heidelberg: Springer Berlin Heidelberg, 2007. http://dx.doi.org/10.1007/b136878.
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Shunmugaperumal, Tamilvanan. Biofilm Eradication and Prevention. Hoboken, NJ, USA: John Wiley & Sons, Inc., 2010. http://dx.doi.org/10.1002/9780470640463.
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Kanematsu, Hideyuki, e Dana M. Barry, a cura di. Biofilm and Materials Science. Cham: Springer International Publishing, 2015. http://dx.doi.org/10.1007/978-3-319-14565-5.
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Rathinam, Navanietha Krishnaraj, e Rajesh K. Sani, a cura di. Introduction to Biofilm Engineering. Washington, DC: American Chemical Society, 2019. http://dx.doi.org/10.1021/bk-2019-1323.
Testo completo
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Chávez de Paz, Luis E., Christine M. Sedgley e Anil Kishen, a cura di. The Root Canal Biofilm. Berlin, Heidelberg: Springer Berlin Heidelberg, 2015. http://dx.doi.org/10.1007/978-3-662-47415-0.
Testo completo
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Lewandowski, Zbigniew. Fundamentals of biofilm research. Boca Raton, FL: CRC Press, 2007.
Cerca il testo completoCapitoli di libri sul tema "Biofilm"
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Kvíderová, Jana. "Biofilm". In Encyclopedia of Astrobiology, 170–71. Berlin, Heidelberg: Springer Berlin Heidelberg, 2011. http://dx.doi.org/10.1007/978-3-642-11274-4_170.
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Kvíderová, Jana. "Biofilm". In Encyclopedia of Astrobiology, 275–77. Berlin, Heidelberg: Springer Berlin Heidelberg, 2015. http://dx.doi.org/10.1007/978-3-662-44185-5_170.
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Mazzoli, Sandra. "Biofilm". In Compendium of Inflammatory Diseases, 215–29. Basel: Springer Basel, 2016. http://dx.doi.org/10.1007/978-3-7643-8550-7_82.
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Morisaki, Hisao. "Biofilm". In Encyclopedia of Biocolloid and Biointerface Science 2V Set, 94–107. Hoboken, NJ, USA: John Wiley & Sons, Inc., 2016. http://dx.doi.org/10.1002/9781119075691.ch7.
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Mazzoli, Sandra. "Biofilm". In Encyclopedia of Inflammatory Diseases, 1–16. Basel: Springer Basel, 2015. http://dx.doi.org/10.1007/978-3-0348-0620-6_82-1.
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Kvíderová, Jana. "Biofilm". In Encyclopedia of Astrobiology, 1–3. Berlin, Heidelberg: Springer Berlin Heidelberg, 2014. http://dx.doi.org/10.1007/978-3-642-27833-4_170-3.
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Kvíderová, Jana. "Biofilm". In Encyclopedia of Astrobiology, 359–61. Berlin, Heidelberg: Springer Berlin Heidelberg, 2023. http://dx.doi.org/10.1007/978-3-662-65093-6_170.
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Verma, Nidhi, e Vishnu Agarwal. "A Review on Current Strategies for Biofilm Control in Food Industry". In Proceedings of the Conference BioSangam 2022: Emerging Trends in Biotechnology (BIOSANGAM 2022), 123–32. Dordrecht: Atlantis Press International BV, 2022. http://dx.doi.org/10.2991/978-94-6463-020-6_13.
Testo completoAbstract (sommario):
AbstractBiofilms are still a serious threat to the world. Biofilms are formed due to the natural tendency of microorganisms according to environmental factors. And they are solicitude in many fields counting food, medical and environmental. Biofilms are hard to exterminate due to their resistant phenotype. Since biofilms is a surface episode it develops on the different surfaces in food industry which can be very severe for the consumers, because it can cause serious illness to the consumers as well as monetary loss. In the current scenario to prevent biofilm formation the basic protocols that are used are cleaning and disinfection which cannot remove biofilms properly. Consequently, the new strategies are developing along with improving conventional control methods. Use of enzymes, biosurfactants, electrostatic interactions, essential oils to prevent biofilm formation.This review intent on the present strategies that are in use or is developing for controlling biofilms. Which can offer statistics about major concerns in food industries.
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Cappitelli, Francesca, e Federica Villa. "Novel Antibiofilm Non-Biocidal Strategies". In Microorganisms in the Deterioration and Preservation of Cultural Heritage, 117–36. Cham: Springer International Publishing, 2021. http://dx.doi.org/10.1007/978-3-030-69411-1_5.
Testo completoAbstract (sommario):
AbstractSubaerial biofilm (SAB) formation on cultural heritage objects is often considered an undesirable process in which microorganisms and their by-products, e.g., enzymes and pigments, cause damage or alteration to a surface. Since biofilms are widespread phenomena, there has been a high demand for preventive and control strategies that resist their formation or reduce their negative effects once formed. Up to date, the main strategy to control biofilms has been the use of biocides. Because of their intrinsic properties, biocidal products can pose risks to humans, animals, and the environment. In this chapter, the authors call “green” only those alternative strategies to biocides able to prevent/control biofilms but that do not kill microorganisms, i.e., irrespective of the use of natural compounds. Here, we describe some of the methods that are most commonly used to test the effectiveness of antibiofilm compounds with multiple-species biofilm model systems. A unified terminology and well described protocols and guidelines are still required to compare and test the effectiveness of traditional or novel compounds against biofilms retrieved on heritage surfaces.
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Tomaszek, J. A., e M. Grabas. "Biofilm Reactors". In Chemistry for the Protection of the Environment 3, 105–16. Boston, MA: Springer US, 1998. http://dx.doi.org/10.1007/978-1-4757-9664-3_13.
Testo completoAtti di convegni sul tema "Biofilm"
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Baczewska, Maria, Arkadiusz Kuś, Katarzyna Gałczyńska, Michał Arabski, Martyna Mazur e Małgorzata Kujawińska. "Interferometric methods as a novel approach for bacterial biofilm degradation research". In Digital Holography and Three-Dimensional Imaging, W4A.27. Washington, D.C.: Optica Publishing Group, 2024. http://dx.doi.org/10.1364/dh.2024.w4a.27.
Testo completoAbstract (sommario):
In this work we present an interferometric approach to quantifying the bacterial growth medium diffusion through a bacterial biofilm pretreated with a tested antibacterial agent. The effect of antibacterial agents on Pseudomonas aeruginosa PAO1 mature biofilm was tested by digital holographic microscopy and laser interferometry and compared with biological tests (spectrofluorimetric measurement of bacterial pyocyanin and pyoverdine production). It is shown that multimodal measurement approach provides better determination of bacterial cell eradication and/or degradation of bacterial matrix forming biofilm.
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Bezryadina, Anna S., Cindy Quintanilla, Brooke Walter-Lakes e Czarlyn Camba. "Optical control and manipulation of bacterial biofilm formation". In Molecular and Nanophotonic Machines, Devices, and Applications VII, a cura di Zouheir Sekkat e Takashige Omatsu, 8. SPIE, 2024. http://dx.doi.org/10.1117/12.3027779.
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Hassanpourfard, Mahtab, Amin Valiei, Thomas Thundat, Yang Liu e Aloke Kumar. "Biofilm Streamer Formation in a Microfluidic Porous Media Mimic". In ASME 2014 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 2014. http://dx.doi.org/10.1115/imece2014-38956.
Testo completoAbstract (sommario):
Several bacterial species possess the ability to attach to surfaces and colonize themselves in thin films called biofilms. Biofilms that grow in porous media are relevant to several industrial and environmental processes such as wastewater treatment and CO2 sequestration. We used Pseudomonas fluorescens, a gram negative aerobic biofilm forming bacteria, to investigate biofilm formation in a microfluidic porous media mimic device. The microfluidic device consists of an array of micro-posts, which were fabricated using soft-lithography. Subsequently, biofilm formation in this device was investigated as a function of time and the formation of filamentous biofilms known as streamers was observed. Furthermore, we used computational fluid mechanics simulation to better understanding of the streamer formation.
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Kumar, Aloke, David Karig, Suresh Neethirajan, Anil K. Suresh, Bernadeta R. Srijanto, Partha P. Mukherjee, Scott Retterer e Mitchel J. Doktycz. "Adhesion and Formation of Microbial Biofilms in Complex Microfluidic Devices". In ASME 2012 Third International Conference on Micro/Nanoscale Heat and Mass Transfer. American Society of Mechanical Engineers, 2012. http://dx.doi.org/10.1115/mnhmt2012-75207.
Testo completoAbstract (sommario):
Shewanella oneidensis is a metal reducing bacterium, which is of interest for bioremediation and clean energy applications. S. oneidensis biofilms play a critical role in several situations such as in microbial energy harvesting devices. Here, we use a microfluidic device to quantify the effects of hydrodynamics on the biofilm morphology of S. oneidensis. For different rates of fluid flow through a complex microfluidic device, we studied the spatiotemporal dynamics of biofilms, and we quantified several morphological features such as spatial distribution, cluster formation and surface coverage. We found that hydrodynamics resulted in significant differences in biofilm dynamics. The baffles in the device created regions of low and high flow in the same device. At higher flow rates, a non-uniform biofilm develops, due to unequal advection in different regions of the microchannel. However, at lower flow rates, a more uniform biofilm evolved. This depicts competition between adhesion events, growth and fluid advection. Atomic force microscopy (AFM) revealed that higher production of extra-cellular polymeric substances (EPS) occurred at higher flow velocities.
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Kargar, Mehdi, Jeff Saucke, Amrinder S. Nain e Bahareh Behkam. "Bioinspired Anti-Biofilm Surfaces Based on Topographical Cues". In ASME 2012 Summer Bioengineering Conference. American Society of Mechanical Engineers, 2012. http://dx.doi.org/10.1115/sbc2012-80847.
Testo completoAbstract (sommario):
Adhesion of bacteria to surfaces is the starting point for formation of biofilms, which tend to be significantly less responsive to antibiotics and antimicrobial stressors, compared with planktonic bacteria. The physicochemical properties of natural anti-biofilm surfaces are being actively studied to develop bioinspired anti-biofilm strategies. It has been shown that –majority of natural anti-biofilm surfaces have well organized micro/nanoscale surfaces features [1]. The difficulties associated with the manufacturing of well-defined and controlled nano-textured surfaces and complexity of the behaviour of microorganisms interacting with engineered surfaces has limited rigorous quantitative study of the state of adhesion of fouling microorganisms to engineered surfaces. The work presented here aims to advance the current understanding of cell-textured surface interaction with the ultimate goal of developing an anti-biofilm design framework based on topographical cues.
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Ferreira, Maria Gabriela, DENISE VON DOLINGER DE BRITO RÖDER, MÁRIO PAULO AMANTE PENATTI, PRISCILA GUERINO VILELA ALVES e RALCIANE DE PAULA MENEZES. "O QUE HÁ DE NOVO SOBRE A AÇÃO DE PRODUTOS NATURAIS NA INIBIÇÃO DA FORMAÇÃO DE BIOFILME POR ISOLADOS DE STAPHYLOCOCCUS AUREUS?" In II Congresso Nacional de Microbiologia Clínica On-line. Revista Multidisciplinar em Saúde, 2022. http://dx.doi.org/10.51161/ii-conamic/34.
Testo completoAbstract (sommario):
Introdução: Staphylococcus aureus é um patógeno oportunista responsável por diversos tipos de infecções, tais como: osteomielite, artrite séptica, endocardite, pneumonia, bacteremia e infecções relacionadas a implantes, impactando nas taxas de morbimortalidade. Além disso, esse microrganismo possui mecanismos de virulência que dificultam a ação dos antimicrobianos, dentre esses mecanismos destaca-se a formação de biofilme, definido como uma comunidade de microrganismos aderidos a uma superfície envoltos por uma matriz extracelular polimérica. Diante disso, estudos que avaliam o potencial anti virulência de compostos naturais tem aumentado ao longo dos anos, com destaque para aquelas substâncias com propriedades terapêuticas já conhecidas. Objetivo: Essa revisão integrativa teve como objetivo elencar os estudos publicados em 2021, que avaliaram a ação de extratos naturais na inibição da formação de biofilme por S. aureus. Material e Métodos: O levantamento bibliográfico foi feito no período de setembro a novembro de 2021, nas bases de dados Pubmed e Portal de Periódicos CAPES utilizando Descritores em Ciências e Saúde: biofilm and extracts, anti biofilm activity of natural extracts, biofilm and S. aureus and natural extracts, biofilm and Gram positive and natural extracts, anti biofilm and Gram positive and natural extracts. Foram selecionados para análise artigos disponíveis na íntegra, publicados entre janeiro e novembro de 2021. Resultados: A busca resultou em 336 artigos, dos quais 11 estavam de acordo com os critérios de inclusão, as plantas utilizadas nos estudos foram: Allium spp., Krameria lappacea, Macrozamia communis, Montrichardia linifera, Zygophyllum coccineum L, Eucalyptus sideroxylon, Illicium verum, Punica granatum L, Sapindus mukorossi, Anthriscus cerefolium e Apis mellifera L. Dentre os extratos vegetais utilizados nos estudos, Allium spp (62,5 µg/mL)., Zygophyllum coccineum L. (3,9 μg/mL) e Eucalyptus sideroxylon (50 µg/mL), foram considerados promissores, pois foram capazes de inibir mais de 66,8% da formação de biofilme por S. aureus em baixas concentrações. Conclusão: A partir dos estudos elencados, extratos naturais possuem ação contra o biofilme de S. aureus. Portanto, esta revisão servirá como um ponto de partida para elaboração de novos estudos, para que esses materiais vegetais possam ser utilizados no tratamento de infecções relacionadas à formação de biofilme.
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Bhaduri, S., S. K. Mitra e A. Kumar. "Understanding Biofilm Growth Dynamics Within a Stagnant Culture of Sporosarcina Pasteurii". In ASME 2014 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 2014. http://dx.doi.org/10.1115/imece2014-36778.
Testo completoAbstract (sommario):
Biofilms are bacterial colonies that form at interfaces, where bacteria are encased in extracellular polymeric substances (EPS). Biofilms are ubiquitous in both artificial systems and our environment. Here we focus on understanding biofilm growth within a stagnant pool of confined diluted culture of the bacteria. Sporosarcina pasteurii is taken as the model bacterium for this study. The motivation behind the choice of this organism stems from the fact that S. Pasteurii has the unique ability to precipitate calcite inside the host media which has tremendous applications in reservoir and restoration engineering. As the biofilm evolves with time inside the confinement, the dynamics of transport is recorded continuously by an optical microscope and the data processed digitally to gain valuable insights into the bio-physical aspects of the system.
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Licina, George J. "Field Experience With On-Line Monitoring of Biofilm Activity". In 2008 7th International Pipeline Conference. ASMEDC, 2008. http://dx.doi.org/10.1115/ipc2008-64141.
Testo completoAbstract (sommario):
Piping reliability is critical to oil production, oil sands processing, refineries, power plants, pulp and paper mills, and various other industries. Corrosion, including Microbiologically Influenced Corrosion (MIC), is a primary degradation mechanism in pipelines. MIC of pipeline materials has been shown to occur in virtually all water systems and has caused expensive unplanned outages, the need for local repairs, and, in some cases, complete system replacement. The control of biofilm on surfaces is the most effective tool for mitigating MIC. Effective monitoring for biofilms also helps to avoid the overuse of oxidizing biocides. Biocide overdosing will increase corrosion and can produce catastrophic corrosion effects. Optimized treatments require accurate, on-line monitoring of biofilm activity. Plant experience with an electrochemical biofilm sensor with integrated data acquisition and data analysis capabilities for monitoring biofilm activity on metallic surfaces and the use of that tool for optimizing biocide additions in a variety of environments is described.
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Veríssimo, Graciete Soares Libório, Ivanize Barbosa De Souza e Paula Carvalhal Lage Von Buettner Ristow. "BIOFILME: MECANISMO DE VIRULÊNCIA BACTERIANA". In II Congresso Brasileiro de Saúde On-line. Revista Multidisciplinar em Saúde, 2021. http://dx.doi.org/10.51161/rems/1503.
Testo completoAbstract (sommario):
Introdução: Biofilmes são comunidades microbianas complexas associada à superfícies bióticas ou abióticas, circundada por uma matriz extracelular polimérica autoproduzida pelos microrganismos ali presente. A formação de biofilme protege os microrganismos de condições ambientais desafiadoras, tornando a antibioticoterapia e mecanismos de defesa imunológica do hospedeiro ineficazes contra bactérias associadas ao biofilme. Objetivo: Este estudo buscou analisar o papel do biofilme como mecanismo que contribui para virulência bacteriana. Material e métodos: Consistiu-se em uma revisão de literatura, a partir de uma abordagem qualitativa, na base de dados Pubmed, utilizando como termo de busca booleano ((biofilm[Title/Abstract]) AND (virulence mechanism[Title/Abstract])) AND (bacteria*[Title/Abstract]). Foram encontrados 19 artigos, compreendendo o período de 2003 a 2021. Resultados: Por muito tempo acreditava-se que as bactérias viviam isoladas no ambiente, hoje é notório que o fenótipo de biofilme ocorre de forma ubíqua e é a principal forma de vida bacteriana. A formação de biofilme por patógenos oportunistas em implantes biomédicos, é considerado sério problema de saúde pública. Implantes biomédicos colonizados por essas bactérias, são mais resistentes a antibioticoterapia, tempo de internação e gerar maior custo ao sistema. A formação de biofilmes em hospedeiros pode ocorrer também com microrganismos aderindo diretamente a órgãos. Pacientes com fibrose cística, infectados de forma crônica por Pseudomonas aeruginosa com capacidade de formação de biofilme nos pulmões do hospedeiro, são a principal causa de mortalidade em pacientes com esta doença. O desenvolvimento de biofilmes também é um fator relacionado à infecções alimentares. Listeria monocytogenes pode causar gastroenterite, listeriose, septicemia, encefalite, endocardite, meningite e abortos, principalmente quando associado a formação de biofilme. A formação de biofilmes também pode contribuir para a transmissão de genes de resistência a antibióticos em sistemas de distribuição de água potável. Estudos detectaram um aumento da presença de bactérias resistentes à antibióticos em tubulações industriais com presença de biofilmes. Conclusão: Biofilmes compreendem o principal estilo de vida bacteriano. A melhor compreensão do estabelecimento desse fenótipo como um mecanismo de virulência e a sua relevância biológica são essenciais para criar soluções para problemas causados por biofilmes, bem como para aplicar a biossíntese de biofilmes sem situações benéficas.
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Klementev, S. V., Yu V. Kulikova e A. S. Sirotkin. "ABILITY OF BACTERIA TO FORM BIOFILMS ON THE AQUEOUS PHASE AFTER HYDROTHERMAL LIQUEFACTION OF ACTIVATED SLUDGE". In X Международная конференция молодых ученых: биоинформатиков, биотехнологов, биофизиков, вирусологов и молекулярных биологов — 2023. Novosibirsk State University, 2023. http://dx.doi.org/10.25205/978-5-4437-1526-1-88.
Testo completoAbstract (sommario):
The ability of bacterial isolates (S2, S7, S9 and S11) to form biofilms for 72 h on the aqueous phase obtained as a result of hydrothermal liquefaction of activated sludge was studied. Experimental results showed that isolates S7 and S11 formed a more massive biofilm compared to other isolates by an average of 43 %. It was noted that during the co-cultivation of isolates S7 and S11, an increase in the massiveness of the biofilm by 96 % was observed compared with separate isolates.
Rapporti di organizzazioni sul tema "Biofilm"
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Wurl, Oliver. Biofilm-like habitat at the sea-surface: A mesocosm study, Cruise No. POS537, 14.09.2019 – 04.10.2019, Malaga (Spain) – Cartagena (Spain) - BIOFILM. University of Oldenburg, novembre 2020. http://dx.doi.org/10.3289/cr_pos537.
Testo completoAbstract (sommario):
OceanRep OceanRep Startseite Kontakt Schnellsuche Einfache Suche Erweiterte Suche Blättern Autor Forschungsbereich Publikationsart Jahr Studiengang Neuzugänge Artikel – begutachtet Alle Über uns GEOMAR Bibliothek Open Access Policies Grundsätze Hilfe FAQs Statistik Impressum Biofilm-like habitat at the sea-surface: A mesocosm study, Cruise No. POS537, 14.09.2019 – 04.10.2019, Malaga (Spain) – Cartagena (Spain) - BIOFILM . Logged in as Heidi Düpow Einträge verwaltenManage recordsManage shelvesProfilGespeicherte SuchenBegutachtungAdminLogout - Tools Wurl, Oliver, Mustaffa, Nur Ili Hamizah, Robinson, Tiera-Brandy, Hoppe, Jennifer, Jaeger, Leonie, Striebel, Maren, Heinrichs, Anna-Lena, Hennings, Laura Margarethe, Goncalves, Rodrigo, Ruiz Gazulla, Carlota und Ferrera, Isabel (2020) Biofilm-like habitat at the sea-surface: A mesocosm study, Cruise No. POS537, 14.09.2019 – 04.10.2019, Malaga (Spain) – Cartagena (Spain) - BIOFILM . Open Access . POSEIDON Berichte . University of Oldenburg, Oldenburg, 35 pp. [img] Text Cruise_Reports_POS537_final.pdf - publizierte Version Available under License Creative Commons: Attribution 4.0. Download (2417Kb) | Vorschau Abstract Biofilm-like properties can form on sea surfaces, but an understanding of the underlying processes leading to the development of these biofilms is not available. We used approaches to study the development of biofilm-like properties at the sea surface, i.e. the number, abundance and diversity of bacterial communities and phytoplankton, the accumulation of gel-like particles and dissolved tracers. During the expedition POS537 we used newly developed and free drifting mesocosms and performed incubation experiments. With these approaches we aim to investigate the role of light and UV radiation as well as the microbes themselves, which lead to the formation of biofilms. With unique microbial interactions and photochemical reactions, sea surface biofilms could be biochemical reactors with significant implications for ocean and climate research, e.g. with respect to the marine carbon cycle, diversity of organisms and oceanatmosphere interactions.
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Stahl, David A. Biofilm Structure and Diversity. Fort Belvoir, VA: Defense Technical Information Center, gennaio 1993. http://dx.doi.org/10.21236/ada267254.
Testo completo
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Bahbah, Jacob. Disruption of Oral Biofilm Formation. Ames (Iowa): Iowa State University, dicembre 2022. http://dx.doi.org/10.31274/cc-20240624-560.
Testo completo
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Tew, Gregory, Meagan Corrigan, Dahui Liu e Richard Scott. Biomimetics for Treating Biofilm-Embedded Infections. Fort Belvoir, VA: Defense Technical Information Center, dicembre 2012. http://dx.doi.org/10.21236/ada581334.
Testo completo
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Harwood, Caroline S. Biofilm Formation by a Metabolically Versatile Bacterium. Fort Belvoir, VA: Defense Technical Information Center, marzo 2009. http://dx.doi.org/10.21236/ada499781.
Testo completo
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Liu, B. Y. M., e J. T. Pfeffer. Modeling for Anaerobic Fixed-Bed Biofilm Reactors. Office of Scientific and Technical Information (OSTI), giugno 1989. http://dx.doi.org/10.2172/1129258.
Testo completo
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Herberg, J., C. Schaldach, J. Horn, E. Gjersing e R. Maxwell. Chemically Specific Cellular Imaging of Biofilm Formation. Office of Scientific and Technical Information (OSTI), febbraio 2006. http://dx.doi.org/10.2172/877758.
Testo completo
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Weller, Carolina, Giorgio Guarnera e Fausto Passariello. Biofilm. From basic science to clinical applications. Fondazione Vasculab, dicembre 2016. http://dx.doi.org/10.24019/2016.biofilm.
Testo completo
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Leschine, Susan. IMPACTS OF BIOFILM FORMATION ON CELLULOSE FERMENTATION. Office of Scientific and Technical Information (OSTI), ottobre 2009. http://dx.doi.org/10.2172/966704.
Testo completo
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Wu, Christine D. Effect of Lactoferrin on Oral Biofilm Formation. Fort Belvoir, VA: Defense Technical Information Center, ottobre 2009. http://dx.doi.org/10.21236/ada523197.
Testo completo