Letteratura scientifica selezionata sul tema "Biofilms"
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Articoli di riviste sul tema "Biofilms"
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Cole, Stephanie J., Angela R. Records, Mona W. Orr, Sara B. Linden e Vincent T. Lee. "Catheter-Associated Urinary Tract Infection by Pseudomonas aeruginosa Is Mediated by Exopolysaccharide-Independent Biofilms". Infection and Immunity 82, n. 5 (4 marzo 2014): 2048–58. http://dx.doi.org/10.1128/iai.01652-14.
Testo completoAbstract (sommario):
ABSTRACTPseudomonas aeruginosais an opportunistic human pathogen that is especially adept at forming surface-associated biofilms.P. aeruginosacauses catheter-associated urinary tract infections (CAUTIs) through biofilm formation on the surface of indwelling catheters.P. aeruginosaencodes three extracellular polysaccharides, PEL, PSL, and alginate, and utilizes the PEL and PSL polysaccharides to form biofilmsin vitro; however, the requirement of these polysaccharides duringin vivoinfections is not well understood. Here we show in a murine model of CAUTI that PAO1, a strain harboringpel,psl, andalggenes, and PA14, a strain harboringpelandalggenes, form biofilms on the implanted catheters. To determine the requirement of exopolysaccharide duringin vivobiofilm infections, we tested isogenic mutants lacking thepel,psl, andalgoperons and showed that PA14 mutants lacking these operons can successfully form biofilms on catheters in the CAUTI model. To determine the host factor(s) that induces the ΔpelDmutant to form biofilm, we tested mouse, human, and artificial urine and show that urine can induce biofilm formation by the PA14 ΔpelDmutant. By testing the major constituents of urine, we show that urea can induce apel-,psl-, andalg-independent biofilm. Thesepel-,psl-, andalg-independent biofilms are mediated by the release of extracellular DNA. Treatment of biofilms formed in urea with DNase I reduced the biofilm, indicating that extracellular DNA supports biofilm formation. Our results indicate that the opportunistic pathogenP. aeruginosautilizes a distinct program to form biofilms that are independent of exopolysaccharides during CAUTI.
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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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Rittmann, B. E. "Where are we with biofilms now? Where are we going?" Water Science and Technology 55, n. 8-9 (1 aprile 2007): 1–7. http://dx.doi.org/10.2166/wst.2007.235.
Testo completoAbstract (sommario):
The IWA's BiofilmVI conference presented a wide range of research on biofilm systems. Particularly popular themes were nitrogen removal, mathematical modelling and microbial ecology. Emerging themes included biofilms with membranes, pathogens in biofilms, biofouling and detachment. Within microbial ecology and mathematical modelling, emphasis was given to N-removal systems, particularly involving nitrifiers and Anammox bacteria. Both themes also recognised the importance of biofilm detachment. Although biofilms on membranes gained attention, little interest was exhibited towards linking biofilms with other advanced materials, such as ceramics, conductors, semi-conductors or nano-materials. Research presented at BiofilmVI marked major advances in improving water sustainability towards removing BOD and N, but did not address many emerging contaminants, such as oxidised contaminants and endocrine disruptors. Attention to energy sustainability, such as with bio-hydrogen or microbial fuel cells, was minimal. Thus, research reported at BiofilmVI was strong towards “improving the expected” with regard to BOD and N removal, but not yet focused on “exploiting the unexpected” to deal with emerging pollutants and bio-energy.
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Kurniawan, Andi, Siti Mariyah Ulfa e Chamidah Chamidah. "The Biosorption of Copper(II) Using a Natural Biofilm Formed on the Stones from the Metro River, Malang City, Indonesia". International Journal of Microbiology 2022 (27 settembre 2022): 1–6. http://dx.doi.org/10.1155/2022/9975333.
Testo completoAbstract (sommario):
Biofilm is the predominant habitat of microbes in aquatic ecosystems. Microhabitat inside the biofilm matrix is a nutrient-rich environment promoted by the adsorption of nutrient ions from the surrounding water. Biofilms can not only adsorb ions that are nutrients but also other ions, such as heavy metals. The ability of biofilm to attract and retain heavy metals, such as copper(II), makes biofilms a promising biosorbent for water pollution treatment. The present study analyzes the characteristics of copper(II) adsorption by biofilms naturally formed in the river. The biofilms used in this study grow naturally on the stones in the Metro River in Malang City, Indonesia. Methods to analyze the adsorption characteristics of copper(II) by biofilms were kinetics of the adsorption and adsorption isotherm. The maximum adsorption amount and the adsorption equilibrium constant were calculated using a variant of the Langmuir isotherm model. In addition, the presence of the functional groups as suggested binding sites in biofilm polymers was investigated using the Fourier transform infrared (FTIR) analysis. The results indicate that copper(II)’s adsorption to the biofilm is a physicochemical process. The adsorption of copper(II) is fitted well with the Langmuir isotherm model, suggesting that the adsorption of copper(II) to a biofilm is due to the interaction between the adsorption sites on the biofilm and the ions. The biofilm’s maximum absorption capacity for copper(II) is calculated to be 2.14 mg/wet-g of biofilm, with the equilibrium rate constant at 0.05 L/mg. Therefore, the biofilms on the stones from river can be a promising biosorbent of copper(II) pollution in aquatic ecosystems.
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Vestweber, Pia Katharina, Jana Wächter, Viktoria Planz, Nathalie Jung e Maike Windbergs. "The interplay of Pseudomonas aeruginosa and Staphylococcus aureus in dual-species biofilms impacts development, antibiotic resistance and virulence of biofilms in in vitro wound infection models". PLOS ONE 19, n. 5 (28 maggio 2024): e0304491. http://dx.doi.org/10.1371/journal.pone.0304491.
Testo completoAbstract (sommario):
Due to high tolerance to antibiotics and pronounced virulence, bacterial biofilms are considered a key factor and major clinical challenge in persistent wound infections. They are typically composed of multiple species, whose interactions determine the biofilm’s structural development, functional properties and thus the progression of wound infections. However, most attempts to study bacterial biofilms in vitro solely rely on mono-species populations, since cultivating multi-species biofilms, especially for prolonged periods of time, poses significant challenges. To address this, the present study examined the influence of bacterial composition on structural biofilm development, morphology and spatial organization, as well as antibiotic tolerance and virulence on human skin cells in the context of persistent wound infections. By creating a wound-mimetic microenvironment, the successful cultivation of dual-species biofilms of two of the most prevalent wound pathogens, Pseudomonas aeruginosa and Staphylococcus aureus, was realized over a period of 72 h. Combining quantitative analysis with electron microscopy and label-free imaging enabled a comprehensive evaluation of the dynamics of biofilm formation and matrix secretion, revealing a twofold increased maturation of dual-species biofilms. Antibiotic tolerance was comparable for both mono-species cultures, however, dual-species communities showed a 50% increase in tolerance, mediated by a significantly reduced penetration of the applied antibiotic into the biofilm matrix. Further synergistic effects were observed, where dual-species biofilms exacerbated wound healing beyond the effects observed from either Pseudomonas or Staphylococcus. Consequently, predicting biofilm development, antimicrobial tolerance and virulence for multi-species biofilms based solely on the results from mono-species biofilms is unreliable. This study underscores the substantial impact of a multi-species composition on biofilm functional properties and emphasizes the need to tailor future studies reflecting the bacterial composition of the respective in vivo situation, leading to a more comprehensive understanding of microbial communities in the context of basic microbiology and the development of effective treatments.
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Sanchez, Carlos J., Kevin S. Akers, Desiree R. Romano, Ronald L. Woodbury, Sharanda K. Hardy, Clinton K. Murray e Joseph C. Wenke. "d-Amino Acids Enhance the Activity of Antimicrobials against Biofilms of Clinical Wound Isolates of Staphylococcus aureus and Pseudomonas aeruginosa". Antimicrobial Agents and Chemotherapy 58, n. 8 (19 maggio 2014): 4353–61. http://dx.doi.org/10.1128/aac.02468-14.
Testo completoAbstract (sommario):
ABSTRACTWithin wounds, microorganisms predominantly exist as biofilms. Biofilms are associated with chronic infections and represent a tremendous clinical challenge. As antibiotics are often ineffective against biofilms, use of dispersal agents as adjunctive, topical therapies for the treatment of wound infections involving biofilms has gained interest. We evaluatedin vitrothe dispersive activity ofd-amino acids (d-AAs) on biofilms from clinical wound isolates ofStaphylococcus aureusandPseudomonas aeruginosa; moreover, we determined whether combinations ofd-AAs and antibiotics (clindamycin, cefazolin, oxacillin, rifampin, and vancomycin forS. aureusand amikacin, colistin, ciprofloxacin, imipenem, and ceftazidime forP. aeruginosa) enhance activity against biofilms.d-Met,d-Phe, andd-Trp at concentrations of ≥5 mM effectively dispersed preformed biofilms ofS. aureusandP. aeruginosaclinical isolates, an effect that was enhanced when they were combined as an equimolar mixture (d-Met/d-Phe/d-Trp). When combined withd-AAs, the activity of rifampin was significantly enhanced against biofilms of clinical isolates ofS. aureus, as indicated by a reduction in the minimum biofilm inhibitory concentration (MBIC) (from 32 to 8 μg/ml) and a >2-log reduction of viable biofilm bacteria compared to treatment with antibiotic alone. The addition ofd-AAs was also observed to enhance the activity of colistin and ciprofloxacin against biofilms ofP. aeruginosa, reducing the observed MBIC and the number of viable bacteria by >2 logs and 1 log at 64 and 32 μg/ml in contrast to antibiotics alone. These findings indicate that the biofilm dispersal activity ofd-AAs may represent an effective strategy, in combination with antimicrobials, to release bacteria from biofilms, subsequently enhancing antimicrobial activity.
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Tran, Hoai My, Hien Tran, Marsilea A. Booth, Kate E. Fox, Thi Hiep Nguyen, Nhiem Tran e Phong A. Tran. "Nanomaterials for Treating Bacterial Biofilms on Implantable Medical Devices". Nanomaterials 10, n. 11 (13 novembre 2020): 2253. http://dx.doi.org/10.3390/nano10112253.
Testo completoAbstract (sommario):
Bacterial biofilms are involved in most device-associated infections and remain a challenge for modern medicine. One major approach to addressing this problem is to prevent the formation of biofilms using novel antimicrobial materials, device surface modification or local drug delivery; however, successful preventive measures are still extremely limited. The other approach is concerned with treating biofilms that have already formed on the devices; this approach is the focus of our manuscript. Treating biofilms associated with medical devices has unique challenges due to the biofilm’s extracellular polymer substance (EPS) and the biofilm bacteria’s resistance to most conventional antimicrobial agents. The treatment is further complicated by the fact that the treatment must be suitable for applying on devices surrounded by host tissue in many cases. Nanomaterials have been extensively investigated for preventing biofilm formation on medical devices, yet their applications in treating bacterial biofilm remains to be further investigated due to the fact that treating the biofilm bacteria and destroying the EPS are much more challenging than preventing adhesion of planktonic bacteria or inhibiting their surface colonization. In this highly focused review, we examined only studies that demonstrated successful EPS destruction and biofilm bacteria killing and provided in-depth description of the nanomaterials and the biofilm eradication efficacy, followed by discussion of key issues in this topic and suggestion for future development.
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Alasil, Saad Musbah, Rahmat Omar, Salmah Ismail, Mohd Yasim Yusof, Ghulam N. Dhabaan e Mahmood Ameen Abdulla. "Evidence of Bacterial Biofilms among Infected and Hypertrophied Tonsils in Correlation with the Microbiology, Histopathology, and Clinical Symptoms of Tonsillar Diseases". International Journal of Otolaryngology 2013 (2013): 1–11. http://dx.doi.org/10.1155/2013/408238.
Testo completoAbstract (sommario):
Diseases of the tonsils are becoming more resistant to antibiotics due to the persistence of bacteria through the formation of biofilms. Therefore, understanding the microbiology and pathophysiology of such diseases represent an important step in the management of biofilm-related infections. We have isolated the microorganisms, evaluated their antimicrobial susceptibility, and detected the presence of bacterial biofilms in tonsillar specimens in correlation with the clinical manifestations of tonsillar diseases. Therefore, a total of 140 palatine tonsils were collected from 70 patients undergoing tonsillectomy at University Malaya Medical Centre. The most recovered isolate wasStaphylococcus aureus(39.65%) followed byHaemophilus influenzae(18.53%). There was high susceptibility against all selected antibiotics except for cotrimoxazole. Bacterial biofilms were detected in 60% of patients and a significant percentage of patients demonstrated infection manifestation rather than obstruction. In addition, an association between clinical symptoms like snore, apnea, nasal obstruction, and tonsillar hypertrophy was found to be related to the microbiology of tonsils particularly to the presence of biofilms. In conclusion, evidence of biofilms in tonsils in correlation with the demonstrated clinical symptoms explains the recalcitrant nature of tonsillar diseases and highlights the importance of biofilm’s early detection and prevention towards better therapeutic management of biofilm-related infections.
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Hengzhuang, Wang, Oana Ciofu, Liang Yang, Hong Wu, Zhijun Song, Antonio Oliver e Niels Høiby. "High β-Lactamase Levels Change the Pharmacodynamics of β-Lactam Antibiotics in Pseudomonas aeruginosa Biofilms". Antimicrobial Agents and Chemotherapy 57, n. 1 (22 ottobre 2012): 196–204. http://dx.doi.org/10.1128/aac.01393-12.
Testo completoAbstract (sommario):
ABSTRACTResistance to β-lactam antibiotics is a frequent problem inPseudomonas aeruginosalung infection of cystic fibrosis (CF) patients. This resistance is mainly due to the hyperproduction of chromosomally encoded β-lactamase and biofilm formation. The purpose of this study was to investigate the role of β-lactamase in the pharmacokinetics (PK) and pharmacodynamics (PD) of ceftazidime and imipenem onP. aeruginosabiofilms.P. aeruginosaPAO1 and its corresponding β-lactamase-overproducing mutant, PAΔDDh2Dh3, were used in this study. Biofilms of these two strains in flow chambers, microtiter plates, and on alginate beads were treated with different concentrations of ceftazidime and imipenem. The kinetics of antibiotics on the biofilms was investigatedin vitroby time-kill methods. Time-dependent killing of ceftazidime was observed in PAO1 biofilms, but concentration-dependent killing activity of ceftazidime was observed for β-lactamase-overproducing biofilms ofP. aeruginosain all three models. Ceftazidime showed time-dependent killing on planktonic PAO1 and PAΔDDh2Dh3. This difference is probably due to the special distribution and accumulation in the biofilm matrix of β-lactamase, which can hydrolyze the β-lactam antibiotics. The PK/PD indices of the AUC/MBIC andCmax/MBIC (AUC is the area under concentration-time curve, MBIC is the minimal biofilm-inhibitory concentration, andCmaxis the maximum concentration of drug in serum) are probably the best parameters to describe the effect of ceftazidime in β-lactamase-overproducingP. aeruginosabiofilms. Meanwhile, imipenem showed time-dependent killing on both PAO1 and PAΔDDh2Dh3 biofilms. An inoculum effect of β-lactams was found for both planktonic and biofilmP. aeruginosacells. The inoculum effect of ceftazidime for the β-lactamase-overproducing mutant PAΔDDh2Dh3 biofilms was more obvious than for PAO1 biofilms, with a requirement of higher antibiotic concentration and a longer period of treatment.
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Oliveira, Maria Alcionéia Carvalho de, Gabriela de Morais Gouvêa Lima, Thalita M. Castaldelli Nishime, Aline Vidal Lacerda Gontijo, Beatriz Rossi Canuto de Menezes, Marcelo Vidigal Caliari, Konstantin Georgiev Kostov e Cristiane Yumi Koga-Ito. "Inhibitory Effect of Cold Atmospheric Plasma on Chronic Wound-Related Multispecies Biofilms". Applied Sciences 11, n. 12 (11 giugno 2021): 5441. http://dx.doi.org/10.3390/app11125441.
Testo completoAbstract (sommario):
The presence of microbial biofilms in the wounds affects negatively the healing process and can contribute to therapeutic failures. This study aimed to establish the effective parameters of cold atmospheric plasma (CAP) against wound-related multispecies and monospecies biofilms, and to evaluate the cytotoxicity and genotoxicity of the protocol. Monospecies and multispecies biofilms were formed by methicillin-resistant Staphylococcus aureus (MRSA), Pseudomonas aeruginosa and Enterococcus faecalis. The monospecies biofilms were grown in 96 wells plates and multispecies biofilm were formed on collagen membranes. The biofilms were exposed to helium CAP for 1, 3, 5 and 7 min. In monospecies biofilms, the inhibitory effect was detected after 1 min of exposure for E. faecalis and after 3 min for MRSA. A reduction in P. aeruginosa biofilm’s viability was detected after 7 min of exposure. For the multispecies biofilms, the reduction in the overall viability was detected after 5 min of exposure to CAP. Additionally, cytotoxicity and genotoxicity were evaluated by MTT assay and static cytometry, respectively. CAP showed low cytotoxicity and no genotoxicity to mouse fibroblastic cell line (3T3). It could be concluded that He-CAP showed inhibitory effect on wound-related multispecies biofilms, with low cytotoxicity and genotoxicity to mammalian cells. These findings point out the potential application of CAP in wound care.
Tesi sul tema "Biofilms"
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Bonsaglia, Erika Carolina Romão [UNESP]. "Produção de biofilme por Listeria monocytogenes isoladas de diferentes alimentos". Universidade Estadual Paulista (UNESP), 2012. http://hdl.handle.net/11449/87783.
Testo completoAbstract (sommario):
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bonsaglia_ecr_me_botib.pdf: 226759 bytes, checksum: ef86655bccf56a9c4ddbb9892ff626f5 (MD5)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
Listeria monocytogenes é uma bactéria frequentemente encontrada em vários alimentos crus, como carne, queijo e legumes. Está amplamente distribuída no ambiente causando a contaminação de alimentos durante seu processamento. Atualmente, a contaminação por L. monocytogenes nas indústrias alimentícias é considerada um dos maiores problemas de segurança alimentar, pois uma vez presente na linha de processamento à bactéria dificilmente é eliminada pela grande capacidade em formar biofilme. A formação de biofilmes em equipamentos pode levar a sérios problemas de higiene e perdas econômicas devido à deterioração dos alimentos e deficiência dos equipamentos. Além disso, a contaminação por patógeno representa um grande risco para saúde. A incidência de listeriose é baixa, mas a taxa de letalidade é alta. Muitos dos focos principais de listeriose têm sido associados ao consumo de alimentos contaminados, especialmente os produtos lácteos. Assim, esse trabalho teve como objetivo analisar a capacidade de formação de biofilme, por 32 cepas de L. monocytogenes isoladas de diferentes alimentos, em diferentes materiais (aço inoxidável, vidro e poliestireno) e temperaturas (4º, 20º, 35ºC) observando a presença do gene luxS e também testar a eficácia de dois sanitizantes alcalino clorado, utilizados para sanitização de planta de processamento de alimentos. Os resultados demonstraram que entre as 32 cepas testadas 25 (78,1%) foram positivas para o gene luxS e a bactéria foi capaz de produzir biofilme em todos os materiais e temperaturas testadas, apresentando maior frequência de cepas produtoras nos materiais hidrofílicos (96,7% vidro e 95,6% inox) do que no hidrofóbico (28%). Os testes com sanitizantes mostraram que as concentrações recomendadas podem ser eficazes desde que utilizados em tempo mínimo...
Listeria monocytogenes is frequently found in many raw foods such as meat, cheese and vegetables, is widely distributed in the environment causing contamination of food during processing. Currently, contamination by L. monocytogenes in food is considered a major food security problems, because once present in the processing line, this bacteria is hardly eliminated by the great ability to form biofilm. The formation of biofilms on equipment can lead to serious health and economic losses due to spoilage and disability equipment. Furthermore, contamination pathogen is a great risk to health. The listeriosis incidence is low, but the fatality rate is high. Many of the main focuses of listeriosis have been linked to consumption of contaminated food, especially dairy products. Thus, this study aimed to analyze 32 strains of L. monocytogenes isolated from different foods to form biofilms on different materials (stainless steel, glass and polystyrene) and temperatures (4 º, 20 º, 35 º C) for the presence of the gene luxS and also test the effectiveness of two sanitizers alkaline chlorine used to sanitize the plant food processing. The results showed that the strains tested 25 (78.1%) were positive for the gene and the bacterium was able to produce biofilm in all materials and temperatures tested, with higher frequency of hydrophilic materials in producing strains (96.7% glass and 95.6% stainless) than in the hydrophobic (12.4%). The tests show that the sanitizing recommended concentrations may be effective if used in minimum time of 30 minutes for the product A and 15 for the product B has led to the elimination of 16 (50%) of the strains tested. We conclude that the gene luxS may be involved in the regulation of biofilm formation, but shouldn’t be the only one, once luxS-negative strains were also producers. We conclude... (Complete abstract click electronic access below)
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Leite, Andressa Rosa Perin [UNESP]. "Avaliação de aspectos relacionados á utilização de um adesivo para próteses totais convencionas: estudo in vitro". Universidade Estadual Paulista (UNESP), 2013. http://hdl.handle.net/11449/97326.
Testo completoAbstract (sommario):
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leite_arp_me_arafo.pdf: 1273945 bytes, checksum: cb5883147f849ba467e943f22b736489 (MD5)O objetivo do presente estudo foi avaliar a influência da utilização de um adesivo para prótese (Ultra Corega creme) na formação de biofilme sobre a superfície interna de próteses totais e na microbiota bucal, no grau de satisfação, além da estimativa de custo médio diário do produto. Trinta pacientes receberam próteses totais novas, e foram divididos em dois protocolos: protocolo 1- utilização do adesivo durante os primeiros 15 dias de teste, seguida por não utilização de nenhum tipo de adesivo durante os próximos 15 dias; protocolo 2- não utilização de adesivo durante os primeiros 15 dias de teste, seguida por utilização do adesivo durante os próximos 15 dias. Após cada período de 15 dias, o biofilme formado na superfície interna das próteses totais foi corado e quantificado por meio de um método fotográfico com o auxílio de um software (Image Tool 3.00). Amostras de material da mucosa palatina e da superfície interna das próteses superiores foram plaqueadas em meios seletivos para Candida spp. e Streptococcus mutans e em um meio não seletivo. Ainda, foi aplicado um questionário para avaliação da satisfação com as próteses e o custo médio diário do produto foi estimado por meio de fórmulas matemáticas. Todas as análises foram realizadas com α = 0,05 e foram empregados testes apropriados à distribuição dos dados. Foi observada formação de biofilme semelhante com ou sem o uso do adesivo sobre as próteses superiores (Wilcoxon, p=0,255) e inferiores (Wilcoxon, p=0,433). Contagens de colônias semelhantes foram observadas com ou sem a utilização do adesivo na mucosa e na superfície interna da prótese total superior (p>0,05). O uso de adesivo proporcionou maior satisfação aos participantes (Wilcoxon, p=0,04). Em média, cada paciente utilizou 3,9 ± 0,3 gramas de adesivo por dia...
The aim of this study was to evaluate the influence of adhesive usage (Ultra Corega cream) on biofilm formation on the internal surface of dentures and oral microbiota, degree of satisfaction, and the estimated average daily cost of product. Thirty patients received new dentures, and have been divided into two protocols: Protocol 1-use of the adhesive during the first 15 days of the test, followed by not using adhesive over the next 15 days; Protocol 2- no use of adhesive for the first 15 days of the test, followed by use of adhesive over the next 15 days. After each period of 15 days, the internal surfaces of the dentures were stained and photographed and the areas (total internal surface and surface stained with biofilm) quantified (Image Tool 3.00). Samples of material from the palatal mucosa and the internal surface of the maxillary denture were plated on selective media for Candida spp. and Streptococcus mutans and a non-selective medium. A questionnaire was applied to evaluate satisfaction with the dentures and the average daily cost of the product was estimated by mathematical formulas. All analyzes were performed with α=.05 and appropriate tests were applied to the data distribution. Similar biofilm formation was found with or without adhesive usage for maxillary (Wilcoxon, p=.255) and mandibular dentures (Wilcoxon, p=.433). Similar colony counts were observed with or without adhesive for mucosa and the internal surface of dentures, irrespective of the culture medium (p>.05). The use of adhesive provided higher satisfaction (Wilcoxon, p=.04). On average, each patient used 3.9 ± 0.3 grams of adhesive per day, equivalent to R $ 4.02 for average daily cost. It is concluded that the use of the adhesive did not affect the quantification of the biofilm and the oral microbiota, besides providing greater overall satisfaction
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Klein, Marlise Inez. "Caracterização fisiologica e genetica de isolados clinicos de Streptococcus mutans". [s.n.], 2006. http://repositorio.unicamp.br/jspui/handle/REPOSIP/288642.
Testo completoAbstract (sommario):
Orientadores: Reginaldo Bruno Gonçalves, Renata de Oliveira Mattos-GranerTese (doutorado) - Universidade Estadual de Campinas, Faculdade de Odontologia de Piracicaba
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Resumo: Streptococcus mutans são os principais patógenos da cárie dentária, um importante problema de saúde pública no país. Para um melhor entendimento da biologia desta espécie bacteriana, o objetivo desta tese de doutorado foi avaliar características genéticas e fisiológicas relacionadas à virulência de isolados clínicos de S. mutans. Neste microrganismo, o sistema de indução da competência, "quorum-sensíng", é dependente da densidade celular e está envolvido na capacidade de crescimento em biofilme. Foram pesquisados, os genes de sistema "quorum-sensíng" e os genes envolvidos no processo de transformação da espécie S. mutans. Foi demonstrada a presença de todos os genes avaliados em S. mutans, bem como a presença de polimorfismo em alguns genes pesquisados, dados ainda inéditos na literatura. Posteriormente, genótipos clínicos de S. mutans foram submetidos a uma análise genética e fisiológica em que foram avaliadas a tolerância e adaptação ao pH ácido, a capacidade de formação de biofilme e curvas de crescimento sob diferentes condições (pHs e diferentes fontes de carbono). Os dados de expressão gênica confirmaram os resultados obtidos nas análises fisiológicas. As cepas clínicas apresentaram um comportamento heterogêneo frente aos mesmos desafios ambientais, o que pode favorecer a sobrevivência das mesmas na cavidade bucal, um ambiente com diversas condições de estresse. Os dados obtidos, comparados aos existentes na literatura, sugerem que além da atividade A TPase, os sistemas de transporte de açúcares fosfotransferase fosfoenolpiruvato:açúcar dependente (pep-PTS) também estariam envolvidos na tolerância de S. mutans ao estresse ácido. Em conjunto, as observações decorrentes das análises efetuadas, nesta tese, podem contribuir para a compreensão dos processos biológicos de S. mutans.
Abstract: Streptococcus mutans is considered the primary etiological agent of human dental caries, an important public health problem in Brazil. The purpose of this thesis was to evaluate genetic and physiologic properties related with virulence in clinical isolates of Streptococcus mutans. The quorum-sensing system, that induces and regulates genetic competence, depends on cellular density and also may play a role in biofilm growth and structure in S. mutans species. A screening of genes of the quorum-sensing system and genes involved with genetic transformation was performed. The analysis revealed that ali genes are widespread within the S. mutans species, and some genes presented polymorphisms. These data are new in the scientific literature. Furthermore, clinical genotypes of S. mutans were subjected to genetic and physiological analysis, including tolerance and acid adaptation to low pH, ability to form stable biofilm and growth kinetic under different conditions (pH and carbon source). The profile of gene expression confirms the data found in the physiologic assays. The studied strains shown heterogenic behavior at the same environmental challenge, that could favor these strains survive in the oral cavity, an environmental with several stress conditions. The data obtained here, and supported by scientific literature, suggest that besides ATPase activity' the sugar:phosphotransferase systems (PTS) could help to mount an adaptive acid tolerance response in S. mutans. Taken together all data obtained in this thesis may help to understand S. mutans biological processes.
Doutorado
Microbiologia e Imunologia
Doutor em Biologia Buco-Dental
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Bonsaglia, Erika Carolina Romão. "Produção de biofilme por Listeria monocytogenes isoladas de diferentes alimentos /". Botucatu, 2012. http://hdl.handle.net/11449/87783.
Testo completoAbstract (sommario):
Orientador: Vera Lúcia Mores RallBanca: José Paes de Almeida Nogueira
Banca: Ary Fernandes Junior
Resumo: Listeria monocytogenes é uma bactéria frequentemente encontrada em vários alimentos crus, como carne, queijo e legumes. Está amplamente distribuída no ambiente causando a contaminação de alimentos durante seu processamento. Atualmente, a contaminação por L. monocytogenes nas indústrias alimentícias é considerada um dos maiores problemas de segurança alimentar, pois uma vez presente na linha de processamento à bactéria dificilmente é eliminada pela grande capacidade em formar biofilme. A formação de biofilmes em equipamentos pode levar a sérios problemas de higiene e perdas econômicas devido à deterioração dos alimentos e deficiência dos equipamentos. Além disso, a contaminação por patógeno representa um grande risco para saúde. A incidência de listeriose é baixa, mas a taxa de letalidade é alta. Muitos dos focos principais de listeriose têm sido associados ao consumo de alimentos contaminados, especialmente os produtos lácteos. Assim, esse trabalho teve como objetivo analisar a capacidade de formação de biofilme, por 32 cepas de L. monocytogenes isoladas de diferentes alimentos, em diferentes materiais (aço inoxidável, vidro e poliestireno) e temperaturas (4º, 20º, 35ºC) observando a presença do gene luxS e também testar a eficácia de dois sanitizantes alcalino clorado, utilizados para sanitização de planta de processamento de alimentos. Os resultados demonstraram que entre as 32 cepas testadas 25 (78,1%) foram positivas para o gene luxS e a bactéria foi capaz de produzir biofilme em todos os materiais e temperaturas testadas, apresentando maior frequência de cepas produtoras nos materiais hidrofílicos (96,7% vidro e 95,6% inox) do que no hidrofóbico (28%). Os testes com sanitizantes mostraram que as concentrações recomendadas podem ser eficazes desde que utilizados em tempo mínimo... (Resumo completo, clicar acesso eletrônico abaixo)
Abstract: Listeria monocytogenes is frequently found in many raw foods such as meat, cheese and vegetables, is widely distributed in the environment causing contamination of food during processing. Currently, contamination by L. monocytogenes in food is considered a major food security problems, because once present in the processing line, this bacteria is hardly eliminated by the great ability to form biofilm. The formation of biofilms on equipment can lead to serious health and economic losses due to spoilage and disability equipment. Furthermore, contamination pathogen is a great risk to health. The listeriosis incidence is low, but the fatality rate is high. Many of the main focuses of listeriosis have been linked to consumption of contaminated food, especially dairy products. Thus, this study aimed to analyze 32 strains of L. monocytogenes isolated from different foods to form biofilms on different materials (stainless steel, glass and polystyrene) and temperatures (4 º, 20 º, 35 º C) for the presence of the gene luxS and also test the effectiveness of two sanitizers alkaline chlorine used to sanitize the plant food processing. The results showed that the strains tested 25 (78.1%) were positive for the gene and the bacterium was able to produce biofilm in all materials and temperatures tested, with higher frequency of hydrophilic materials in producing strains (96.7% glass and 95.6% stainless) than in the hydrophobic (12.4%). The tests show that the sanitizing recommended concentrations may be effective if used in minimum time of 30 minutes for the product A and 15 for the product B has led to the elimination of 16 (50%) of the strains tested. We conclude that the gene luxS may be involved in the regulation of biofilm formation, but shouldn't be the only one, once luxS-negative strains were also producers. We conclude... (Complete abstract click electronic access below)
Mestre
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Leite, Andressa Rosa Perin. "Avaliação de aspectos relacionados á utilização de um adesivo para próteses totais convencionas: estudo in vitro /". Araraquara, 2013. http://hdl.handle.net/11449/97326.
Testo completoAbstract (sommario):
Orientador: Ana Carolina PeroBanca: Marco Antonio Compagnoni
Banca: Raphael Freitas de Souza
Resumo: O objetivo do presente estudo foi avaliar a influência da utilização de um adesivo para prótese (Ultra Corega creme) na formação de biofilme sobre a superfície interna de próteses totais e na microbiota bucal, no grau de satisfação, além da estimativa de custo médio diário do produto. Trinta pacientes receberam próteses totais novas, e foram divididos em dois protocolos: protocolo 1- utilização do adesivo durante os primeiros 15 dias de teste, seguida por não utilização de nenhum tipo de adesivo durante os próximos 15 dias; protocolo 2- não utilização de adesivo durante os primeiros 15 dias de teste, seguida por utilização do adesivo durante os próximos 15 dias. Após cada período de 15 dias, o biofilme formado na superfície interna das próteses totais foi corado e quantificado por meio de um método fotográfico com o auxílio de um software (Image Tool 3.00). Amostras de material da mucosa palatina e da superfície interna das próteses superiores foram plaqueadas em meios seletivos para Candida spp. e Streptococcus mutans e em um meio não seletivo. Ainda, foi aplicado um questionário para avaliação da satisfação com as próteses e o custo médio diário do produto foi estimado por meio de fórmulas matemáticas. Todas as análises foram realizadas com α = 0,05 e foram empregados testes apropriados à distribuição dos dados. Foi observada formação de biofilme semelhante com ou sem o uso do adesivo sobre as próteses superiores (Wilcoxon, p=0,255) e inferiores (Wilcoxon, p=0,433). Contagens de colônias semelhantes foram observadas com ou sem a utilização do adesivo na mucosa e na superfície interna da prótese total superior (p>0,05). O uso de adesivo proporcionou maior satisfação aos participantes (Wilcoxon, p=0,04). Em média, cada paciente utilizou 3,9 ± 0,3 gramas de adesivo por dia... (Resumo completo, clicar acesso eletrônico abaixo)
Abstract: The aim of this study was to evaluate the influence of adhesive usage (Ultra Corega cream) on biofilm formation on the internal surface of dentures and oral microbiota, degree of satisfaction, and the estimated average daily cost of product. Thirty patients received new dentures, and have been divided into two protocols: Protocol 1-use of the adhesive during the first 15 days of the test, followed by not using adhesive over the next 15 days; Protocol 2- no use of adhesive for the first 15 days of the test, followed by use of adhesive over the next 15 days. After each period of 15 days, the internal surfaces of the dentures were stained and photographed and the areas (total internal surface and surface stained with biofilm) quantified (Image Tool 3.00). Samples of material from the palatal mucosa and the internal surface of the maxillary denture were plated on selective media for Candida spp. and Streptococcus mutans and a non-selective medium. A questionnaire was applied to evaluate satisfaction with the dentures and the average daily cost of the product was estimated by mathematical formulas. All analyzes were performed with α=.05 and appropriate tests were applied to the data distribution. Similar biofilm formation was found with or without adhesive usage for maxillary (Wilcoxon, p=.255) and mandibular dentures (Wilcoxon, p=.433). Similar colony counts were observed with or without adhesive for mucosa and the internal surface of dentures, irrespective of the culture medium (p>.05). The use of adhesive provided higher satisfaction (Wilcoxon, p=.04). On average, each patient used 3.9 ± 0.3 grams of adhesive per day, equivalent to R $ 4.02 for average daily cost. It is concluded that the use of the adhesive did not affect the quantification of the biofilm and the oral microbiota, besides providing greater overall satisfaction
Doutor
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Brain, Stephen. "Monitoring microbial biofilms". Thesis, London South Bank University, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.337401.
Testo completo
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Pinto, Geraldo Camilo de Souza [UNESP]. "Eficácia da terapia fotodinâmica antimicrobiana em biofilmes de Staphylococcus Aureus suscetível e resistente á meticilina". Universidade Estadual Paulista (UNESP), 2013. http://hdl.handle.net/11449/97310.
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pinto_gcs_me_arafo.pdf: 899028 bytes, checksum: 57f6b9a787b99be24637541e57cbfc9c (MD5)A necessidade de superar o desafio criado pelos biofilmes resistentes aos tratamentos antimicrobianos convencionais tem levado à busca por tratamentos alternativos, como terapia fotodinâmica antimicrobiana (aPDT). Este estudo avaliou in vitro a eficácia da aPDT na inativação de biofilmes de Staphylococcus aureus suscetíveis e resistentes à meticilina (MRSA e MSSA), mediado pelos fotossensibilizadores (PSs) Curcumina (Cur) e Photodithazine® (PDZ). Biofilmes foram formados e tratados com diferentes concentrações de Cur (0, 20, 40 e 80 μM) e PDZ (0, 50 e 75 mg/L), e iluminados ou não por fonte de luz LED (Cur 455 ± 3 nm/ 5,28 J/cm2; PDZ 660 ± 3 nm/ 5,28 J/cm2 ou 50 J/cm²). Os grupos Controle Positivo (CP) não receberam nenhum PS e também não foram iluminados. A viabilidade dos micro-organismos após a aPDT foi avaliado pelo número de colônias viáveis, pelo ensaio de XTT e pela utilização do kit LIVE/DEAD® na Microscopia Confocal de Varredura à Laser (MCVL). Os resultados foram avaliados por análises de variância de dois fatores de efeitos fixos (ANOVA) e complementados por comparações múltiplas de médias pelo teste de Tukey. Para ambas as cepas, todas as concentrações de Cur e PDZ testadas reduziram significativamente a atividade metabólica e o UFC/mL para ambos micro-organismos quando comparado com os grupos CN (p0,05). Os resultados foram otimizados para a Cur quando utilizou-se a maior concentração (80 μM), para a PDZ, a maior redução nos micro-organismos foi observada quando associou-se a maior concentração de PDZ (75 mg/L) com a maior dose de luz (50 J/cm²). Os biofilmes submetidos a aPDT demostraram pela MCVL um maior número de células coradas em vermelho, indicando que a aPDT foi eficaz para promover danos ou morte às células bacterianas. Assim, a aPDT pode ser considerada promissora para atuar de forma sinérgica no tratamento de infecções bacterianas
The need to overcome the challenge created by biofilms regarding conventional antimicrobial approaches has lead to search of alternative treatments such as Antimicrobial Photodynamic Therapy (aPDT). This in vitro study evaluated the efficacy of aPDT using the photosensitizer (PS) Curcumin (Cur) and Photodithazine® (PDZ) in the inactivation of biofilms of methicillin susceptible and resistant S. aureus (MSSA and MRSA). Biofilms were treated with different Cur (0, 20, 40 or 80 μM of Cur) and PDZ concentrations (0, 50 or 75 mg/L) and illuminated or not with LED source (Cur 455 ± 3 nm/ 5.28 J/cm2; PDZ 660 ± 3 nm/ 5.28 J/cm2 or 50 J/cm²). Positive control samples were not exposed to PS or light. The microorganisms viability after aPDT were evaluated by counting the number of colonies, the XTT assay and LIVE/DEAD® staining using confocal laser scanning microscopy (CLSM). The results were evaluated by analysis of variance, two-factor fixed effects (ANOVA) and complemented by multiple comparisons by Tukey test. For both strains, all the tested Cur and PDZ concentrations reduced significantly both biofilm metabolic activity and CFU/mL compared to the negative control (p0.05). Moreover, the results were optimized for Cur when the higher concentration was used (80 μM); For PDZ, the best results were obtained when it was associated a higher concentration of PDZ (75 mg/L) with the higher dose of light (50 J/cm²). Biofilms submitted to aPDT showed a large number of red-stained colonies, indicating that this therapy was efficient in disrupting the bacterial membrane. It can be concluded that PS was efficient in reducing viable colonies of both S. aureus strains by damaging cell membrane and causing cell death. Thus, the aPDT is can be considered promising to act synergistically in the treatment of bacterial infections
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Quishida, Cristiane Campos Costa [UNESP]. "Estudo da eficácia da terapia fotodinâmica, mediada pelos fotossensibilizadores Photodithazine® e Curcumina, sobre biofilmes multi-espécies formados por Streptococcus mutans, Candida albicans e Candida glabrata". Universidade Estadual Paulista (UNESP), 2013. http://hdl.handle.net/11449/105516.
Testo completoAbstract (sommario):
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000740082.pdf: 4167341 bytes, checksum: 8fe87af8a33480548b14b44df006b99a (MD5)A capacidade de aderência dos micro-organismos a diferentes superfícies, a resistência a medicamentos, bem como a interação entre as espécies visam garantir a sobrevivência e a proliferação dos mesmos, resultando em menor susceptibilidade dos patógenos aos tratamentos e aos procedimentos de desinfecção. Este estudo teve como objetivo avaliar in vitro a eficácia da Terapia Fotodinâmica (PDT) mediada pelos fotossensibilizadores (FSs) Photodithazine® (PDZ) e Curcumina (Cur) sobre biofilmes multi-espécies compostos por Streptococcus mutans, Candida albicans e Candida glabrata. Para isso, o estudo foi divido em três partes: 1- avaliação do efeito fotodinâmico das diferentes concentrações de PDZ (100, 150, 175, 200 e 250mg/L) associada à luz LED (660nm/ 37,5J/cm2) na inativação de biofilme multi-espécies formado em fundo de placa de 96 orifícios; 2- avaliação do efeito fotodinâmico quando realizadas uma e três aplicações sucessivas de PDT, mediada por PDZ (175 e 200mg/L) e luz LED (660nm/ 37,5J/cm2) na inativação de biofilmes multi-espécies, formado sobre corpos-de-prova de resina acrílica. 3- avaliação do efeito fotodinâmico de diferentes concentrações do FS Cur (80, 100 e 120μM) associada à luz LED (455nm/ 37,5J/cm2) sobre biofilmes multi-espécies cultivados por diferentes períodos (24 e 48h) sobre corpos-de-prova de resina acrílica. Adicionalmente para cada condição avaliada foi verificado o efeito da aplicação isolada de cada concentração dos FSs PDZ e Cur em contato com o biofilme na ausência de luz (P+L-) e o efeito isolado da luz (P-L+). Além disso, foi realizado o grupo controle positivo, no qual o biofilme não esteve em contato com o FS e não foram iluminados com luz LED (P-L-). Após a aplicação dos tratamentos propostos, a viabilidade dos micro-organismos foi avaliada por meio da contagem de colônias (UFC/mL), teste do XTT, determinação da...
The ability of adhesion of microrganisms to different surfaces, the drug resistance, as well as the interaction among the species help to ensure the survival and proliferation of these microrganisms and result in lower susceptibility of these pathogens to treatment and disinfection procedures. This study aimed to evaluate the in vitro efficacy of PDT mediated by photosensitizers (FSs) Photodithazine ® (PDZ) and Curcumin (Cur) against multispecies biofilms formed by Candida albicans, Candida glabrata and Streptococcus mutans. This study was divided into three parts: 1. evaluation of the effect of photodynamic therapy of different concentrations of PDZ (100, 150, 175, 200 and 250mg / L) associated with the LED light (660 nm / 37.5 J/cm2) in the inactivation of multspecies biofilms formed in 96-well microtiter plates; 2. evaluation of the photodynamic effect of one PDT applications only and three successive PDT applications mediated by PDZ (175 and 200 mg / L) and LED light (660 nm / 37.5 J/cm2) in the inactivation of multispecies biofilms, formed on acrylic resin samples; 3. evaluation of the photodynamic effect of different concentrations of Cur FS (80, 100, and 120μM) associated with LED light (455nm / 37.5 J/cm2) against multispecies biofilms grown during different periods (24 and 48h) on acrylic resin samples. Additional samples were treated either with FSs (PDZ or Cur) (P+L-) or LED light (P-L+) only. Positive control samples had neither light nor FSs (PDZ or Cur) (P-L-). After applying the proposed treatments, the viability of microrganisms was assessed by Colony Count (CFU / mL), the XTT assay, determination of the total biomass (CV) and confocal laser scanning microscopy (CLSM).The results were analyzed using ANOVA or Kruskal-Wallis test followed by Tukey or Dunn, respectively. For the biofilm formed in 96-well plate, the concentrations of 175 and 200mg/L showed greater reduction in cell...
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Monteiro, Douglas Roberto [UNESP]. "Análise da ação de nanopartículas de prata sobre o biofilme de espécies de Candida". Universidade Estadual Paulista (UNESP), 2012. http://hdl.handle.net/11449/105564.
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monteiro_dr_dr_araca.pdf: 4433371 bytes, checksum: 7ace13af6a3345bfc97059baad093841 (MD5)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
O objetivo deste estudo foi avaliar a atividade antifúngica de nanopartículas de prata (NP) contra os biofilmes de Candida albicans e Candida glabrata. NP foram sintetizadas por meio da redução do nitrato de prata com citrato de sódio e estabilizadas com amônia ou polivinilpirrolidona. Os testes de concentração inibitória mínima (CIM) das NP contra células de Candida foram baseados no método da microdiluição. NP foram aplicadas sobre os biofilmes de Candida (48 horas) e após 24 horas de contato sua atividade antifúngica foi determinada por meio da quantificação da biomassa total (coloração com violeta cristal (VC)) e por meio da enumeração das unidades formadoras de colônias (UFCs). Após o tratamento com NP, as matrizes dos biofilmes foram extraídas e analisadas em termos de proteínas, carboidratos e DNA, e a estrutura dos biofilmes foi analisada por meio da microscopia eletrônica de varredura e de epifluorescência. A atividade antibiofilme da combinação de NP com nistatina e clorexidina foi avaliada por meio dos ensaios de VC e UFCs. Leveduras viáveis foram recuperadas a partir dos biofilmes previamente tratados com NP e adicionadas às células epiteliais HeLa e aos poços de placas de poliestireno e, após 2 horas de contato, a adesão foi determinada usando VC. A eficácia de NP submetidas às variações de temperatura (50, 70 e 100ºC) e pH (5 e 9) também foi avaliada, assim como a susceptibilidade às NP dos biofilmes de Candida em diferentes fases de crescimento. Os resultados de CIM mostraram que NP foram fungicidas contra os isolados testados em concentrações baixas (0,4-3,3 μg/mL). NP foram mais efetivas na redução da biomassa para os biofilmes de C. glabrata (reduções de 90% na concentração de 108 μg/mL) do que para C. albicans, e promoveram reduções significativas no log10 do número de UFCs...
The aim of this study was to evaluate the antifungal activity of silver nanoparticles (SN) against Candida albicans and Candida glabrata biofilms. Colloidal suspensions of SN were synthesized by reducing silver nitrate with sodium citrate and stabilized with ammonia or polyvinylpyrrolidone. Minimal inhibitory concentrations (MIC) were performed for Candida cells grown in suspension following the microbroth dilution method. Candida biofilms (48 h) were treated with SN for 24 h and then the total biomass quantification (by crystal violet (CV) staining) and the colony forming units (CFUs) were determined. Also, after treating with SN, extracellular matrices were extracted from Candida biofilms and analyzed chemically in terms of proteins, carbohydrates and DNA. To investigate the biofilm structure, scanning electron microscopy and epifluorescence microscopy were carried out. The antibiofilm activity of SN in combination with nystatin and chlorhexidine was also assessed by CV and CFU. Moreover, viable yeasts were recovered from the biofilms pretreated with SN and added to HeLa epithelial cells or to empty wells of polystyrene plates and, after 2 h of contact, the adhesion capacity of the yeasts was determined by using CV staining. The antibiofilm efficacy of SN subjected to variations of temperature (50, 70 and 100ºC) and pH (5 and 9) was also evaluated. Finally, the susceptibility to SN of biofilms in different stages of growth was analyzed. MIC results showed that SN were fungicidal against the tested strains at very low concentrations (0.4- 3.3 μg/mL). SN were more effective in reducing the total biomass of C. glabrata (reductions around 90% at 108 μg/mL SN) than C. albicans biofilms, and provided significant log10 reduction of... (Complete abstract click electronic access below)
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Francisconi, Renata Serignoli [UNESP]. "Efeito do óleo essencial de Melaleuca alternifolia e de seu principal componente Terpinen-4-ol sobre isolados clínicos de Candida albicans resistentes". Universidade Estadual Paulista (UNESP), 2014. http://hdl.handle.net/11449/116010.
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000806425.pdf: 2132825 bytes, checksum: 171c310b3265e76efa3377d61b47cbf7 (MD5)O óleo essencial de Melaleuca alternifolia (TTO) é um extrato de ação antifúngica e preventiva em escala farmacêutica ou cosmética. O objetivo deste estudo foi avaliar a eficácia do TTO e Terpinen-4-ol sobre isolados clínicos de Candida albicans. Este estudo foi realizado em três fases: 1- Identificação da CIM (Concentração Inibitória Mínima) e CFM (Concentração Fungicida Mínima) do TTO (0,25 a 2%) e Terpinen-4- ol (0,11 a 0,95%) sobre C. albicans na forma planctônica. 2- Análise das diferentes concentrações do óleo sobre biofilme monoespécie de C. albicans por meio da contagem das UFC/mL e avaliação da atividade metabólica das células pelo método colorimétrico de XTT. 3- Análise da ação inibitória das soluções de TTO e Terpinen-4- ol sobre biofilmes de C.albicans (cepa padrão e isolados clínicos) formados em corpos de prova de resina acrílica termopolimerizável previamente cobertos com saliva humana, por meio do teste de XTT e por microscopia confocal de varredura à laser (MCVL). A nistatina (Sigma) foi utilizada como controle positivo. Os resultados mostraram que isolados de C. albicans planctônicos foram sensíveis ao TTO 1%, Terpinen-4-ol 0,47% e Nistatina 8 ?g/mL. As menores concentrações fungicidas para os isolados foram TTO 2 %, Terpinen-4-ol 0,95 % e Nistatina 16 ?g/mL. Quando analisado em biofilme através da quantificação (UFC/mL) e teste de XTT as concentrações de TTO 2 % e Terpinen-4-ol 0,95 % foram eficazes quando comparado ao controle, sendo que as amostras da genotipagem A2 e B1 foram as mais resistentes. Os resultados de MCVL mostraram que todos os biofilmes desenvolvidos em corpos de resina acrílica apresentaram-se semelhantes à ação da Nistatina. Os extratos avaliados apresentaram ação antifúngica para os isolados clínicos e podem ser considerados tratamento alternativo para paciente com candidíase.
The essential oil of Melaleuca alternifolia (TTO) is an extract of antifungal action and preventive in pharmaceutical or cosmetic scale. The aim of this study was to evaluate the efficacy of TTO and Terpinen-4-ol against clinical isolates of Candida albicans. This study was conducted in three phases: 1- Identification of MIC (Minimum Inhibitory Concentration) and CFM (Minimum Fungicidal Concentration) of TTO (0.25 to 2%) and Terpinen-4-ol (0.11 to 0.95 %) on C. albicans in planktonic form . 2- Analysis of different concentrations of oil on C. albicans biofilm single species by counting CFU/mL and evaluation of the metabolic activity of cells by XTT colorimetric method. 3- Analysis of the inhibitory action of TTO and Terpinen-4-ol solutions on C. albicans biofilms (standard strain and clinical isolates) formed in specimens of polymerizable resin acrylic microwave previously coated with human saliva , by means of the XTT test and confocal laser scanning microscopy (CLSM) . The nystatin (Sigma) was used as a positive control. The results showed that isolates of C. albicans planktonic were sensitive to TTO 1%, Terpinen-4-ol 0.47% and Nystatin 8 mg/mL. The smaller fungicidal concentrations for the isolates were TTO 2%, Terpinen-4-ol 0.95% and Nystatin 16 mg / mL. When analyzed by quantifying biofilm (CFU / ml) and XTT test, the concentrations TTO 2% and Terpinen-4-ol 0.95% were effective when compared to the control, and genotyping of samples A2 and B1 were more resistant. The CLSM results showed that all biofilms developed in bodies of acrylic resin were similar to the action of Nystatin. The extracts showed antifungal action for the clinical isolates and can be considered an alternative treatment for patients with candidiasis.
Libri sul tema "Biofilms"
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J, Doyle Ronald, a cura di. Biofilms. San Diego, CA: Academic Press, 1999.
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G, Characklis William, e Marshall Kevin C, a cura di. Biofilms. New York: Wiley, 1990.
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J, Doyle Ronald, a cura di. Biofilms. San Diego, CA: Academic Press, 1999.
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Ghannoum, Mahmoud, Matthew Parsek, Marvin Whiteley e Pranab K. Mukherjee, a cura di. Microbial Biofilms. Washington, DC, USA: ASM Press, 2015. http://dx.doi.org/10.1128/9781555817466.
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Seneviratne, Chaminda Jayampath. Microbial Biofilms. Boca Raton, FL : CRC Press, 2017.: CRC Press, 2017. http://dx.doi.org/10.4324/9781315120119.
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Maddela, Naga Raju, e Aransiola Sesan Abiodun. Microbial Biofilms. Boca Raton: CRC Press, 2022. http://dx.doi.org/10.1201/9781003184942.
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Muffler, Kai, e Roland Ulber, a cura di. Productive Biofilms. Cham: Springer International Publishing, 2014. http://dx.doi.org/10.1007/978-3-319-09695-7.
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Donelli, Gianfranco, a cura di. Microbial Biofilms. New York, NY: Springer New York, 2014. http://dx.doi.org/10.1007/978-1-4939-0467-9.
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Romeo, Tony, a cura di. Bacterial Biofilms. Berlin, Heidelberg: Springer Berlin Heidelberg, 2008. http://dx.doi.org/10.1007/978-3-540-75418-3.
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Kaushik, Karishma S., e Sophie E. Darch, a cura di. Multispecies Biofilms. Cham: Springer International Publishing, 2023. http://dx.doi.org/10.1007/978-3-031-15349-5.
Testo completoCapitoli di libri sul tema "Biofilms"
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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.
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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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Zhang, Wen. "Biofilms". In Women in Water Quality, 135–49. Cham: Springer International Publishing, 2019. http://dx.doi.org/10.1007/978-3-030-17819-2_8.
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Maresso, Anthony William. "Biofilms". In Bacterial Virulence, 145–53. Cham: Springer International Publishing, 2019. http://dx.doi.org/10.1007/978-3-030-20464-8_12.
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Kim, Shin-Hee, e Cheng-I. Wei. "Biofilms". In Decontamination of Fresh and Minimally Processed Produce, 59–75. Oxford, UK: Wiley-Blackwell, 2012. http://dx.doi.org/10.1002/9781118229187.ch3.
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Woodworth, Bradford A., Noam A. Cohen e James N. Palmer. "Biofilms". In Rhinology and Facial Plastic Surgery, 241–46. Berlin, Heidelberg: Springer Berlin Heidelberg, 2009. http://dx.doi.org/10.1007/978-3-540-74380-4_20.
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Woodworth, Bradford A., e James N. Palmer. "Biofilms". In Nasal Polyposis, 75–81. Berlin, Heidelberg: Springer Berlin Heidelberg, 2010. http://dx.doi.org/10.1007/978-3-642-11412-0_9.
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Koch, Thomas. "Biofilms". In Encyclopedia of Lubricants and Lubrication, 163–68. Berlin, Heidelberg: Springer Berlin Heidelberg, 2014. http://dx.doi.org/10.1007/978-3-642-22647-2_269.
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Bahar, Sonya. "Biofilms". In The Essential Tension, 153–73. Dordrecht: Springer Netherlands, 2017. http://dx.doi.org/10.1007/978-94-024-1054-9_9.
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Reitner, Joachim. "Biofilms". In Encyclopedia of Geobiology, 134–35. Dordrecht: Springer Netherlands, 2011. http://dx.doi.org/10.1007/978-1-4020-9212-1_27.
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Vlamakis, Hera, e Roberto Kolter. "Biofilms". In Bacterial Stress Responses, 365–73. Washington, DC, USA: ASM Press, 2014. http://dx.doi.org/10.1128/9781555816841.ch21.
Testo completoAtti di convegni sul tema "Biofilms"
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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.
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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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Salek, M., e R. J. Martinuzzi. "Numerical Simulation of Fluid Flow and Oxygen Transport in the Tube Flow Cells Containing Biofilms". In ASME/JSME 2007 5th Joint Fluids Engineering Conference. ASMEDC, 2007. http://dx.doi.org/10.1115/fedsm2007-37063.
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The hydrodynamics in flow systems is known to induce phenotypic changes associated with bacterial biofilms, including increased tolerance to antimicrobial agents and biocides. Results obtained in flow cells commonly used in biological and medical studies on the influence of flow on biofilm behavior and antimicrobial susceptibility are sometimes contradictory. It is thus hypothesized that discrepancies in the results may be related to the flow cell geometry. In this study, the shear stress distribution and substrate concentration were numerically simulated inside long rectangular and square tubes. The fluid was Newtonian and a uniform distribution of biofilms, which consume the substrate from the medium, was assumed on the walls. The consumption of oxygen by biofilms was assumed to follow the Monod kinetics. The effects of flow velocity, flow cell geometry, and substrate diffusivity on wall shear stress and substrate concentration distributions were investigated. Based on simulation results, differences observed in the morphology and response of biofilms can be directly related to hydrodynamic changes caused by the flow cell configuration.
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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.
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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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Arman Kandirmaz, Emine, e Omer Bunyamin Zelzele. "The production of ecofriendly biofilm with natural oil for food packaging". In 10th International Symposium on Graphic Engineering and Design. University of Novi Sad, Faculty of technical sciences, Department of graphic engineering and design,, 2020. http://dx.doi.org/10.24867/grid-2020-p23.
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The use of edible biofilms in food packaging reduces the use of petrochemical polymers that are harmful to human health, such as PE, PP, PET. The second most common biopolymer in nature, chitosan is a nontoxic, nonantigenic, biocompatible and biodegradable polymer. Considering these features, it is frequently used in food packaging applications. Increasing needs for food amount and quality canalized food ındustry to fund in new packaging techniques that improve storage life and grade of foods. Active packaging systems, one of these methods, can be designed as a sensor, antimicrobial or antimigrant in order to extend the shelf life of the food product and to inform the shelf life in possible degradation. Essential oils, which are antimicrobial environmentally friendly packaging material additives, are used due to their effective biological activities. Essential oils that have known antimicrobial properties include lavender, rosemary, mint, eucalyptus and geranium. These oils are also edible. In this study, it is aimed to produce antimicrobial, ecofriendly, edible, printable biofilm for active packaging, using chitosan and peppermint essential oil. For this purpose, chitosan biofilms containing different rates (0, 1, 2.5, 5, 10%) of peppermint essential oil were produced by solvent casting method. Surface morphology were examined by SEM. The transparency of biofilms was determined by UV spectroscopy. Antimicrobial properties of the obtained films were determined against S. aureus and E. coli. Biofilms were printed with screen printing. The color, gloss, contact angle, surface tension values of all printed and unprinted samples were examined. As a result, chitosan biofilms which are loaded with peppermint essential oil were successfully produced. Biofilms are colorless, highly transparent and have good printability. It is concluded that the amount of peppermint essential oil increased inhibitory feature against S. aureus and E. coli. When the obtained results are examined, it is determined that the printable, ecofriendly, edible biofilms can be used in active food packaging applications.
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IBRAHIM, Raghad, Hussain K.K.AL-DULAIMY e Izdehar M. JASIM. "DETERMINATION OF BIOFILM FORMATION GENES USING PCR TECHNIQUE FOR STAPH. SPP. ISOLATIONS FROM WOUND AND BURN INFECTIONS IN BAQUBA CITY". In IV.International Scientific Congress of Pure,Appliedand Technological Sciences. Rimar Academy, 2022. http://dx.doi.org/10.47832/minarcongress4-17.
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The bacteria Staphylococcus aureus has been discovered to be a major source of community and hospital-acquired infections. The production of ica-dependent biofilms is critical in the persistence of infections in hospitalized patients. Between November 2017 &April 2018, the current study was conducted at Teaching Baquba Hospital's Bacteriology Laboratory in Baquba City and the laboratory of microbiology and polymerase chain reaction (PCR )unit in the Biology Department / College of Science/ Diyala University (2018). Materials and methods: We obtained 13(17.3%) Staph.aureus isolates from 100 clinical specimens (burns, wounds, urine, and blood) after identified them. Following by employed Congo Red Agar(CRA) and tissue culture plate method (TCP)to detect Biofilm development in isolates, as well as a PCR assay and particular primers to determine the presence of the icaA &icaD genes. The results showed ica A/D were found in 69 % (9/13) of cases, icaA gene is present at 7 (53.8%) and the icaD gene at 2(15 .3%) in Staph.aureus isolates. CRA method found biofilm generation in 6 (46%) of thirteen Staph. aureus isolates, while TCP detected biofilm creation in 10 (76%) isolates. When phenotypic approaches compared to the detection of the icaA and icaD genes, only 5 (71%) of the icaA genes were found to be positive by TCP, while only 2 (1% ) of the icaD genes were found to be positive by TCP. In short: The findings show the significance of S. aureus' virulence factors in clinical samples for the icaA and icaD genes and the phenotypic biofilm formation variety. The creation of in vitro slime using the CRA approach is not necessarily consistent even when the icaA and icaD genes exist. Although certain isolates lack the genes icaA & icaD, the ability to generate biofilms highlights the importance of the further gene research, and the absence of the icaA and icaD genes, the capability from certain isolates to create biopolymes emphasises the need for continuous genetic study into icas caused by variations in the number of genes associated with biofilms. When comparing phenotypic techniques, TCP is still the best tool for the screening of biofilms. The aim of this research though is that the biofilm forming potential should be actually linked to the presence of icaA and icaD genes in S. aureus isolates
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Yevstigneyeva, S. S., Yu P. Fedonenko e A. V. Shelud’ko. "Biofilms of Azospirillum brasilense and Azospirillum lipoferum and their resistance to abiotic stresses". In 2nd International Scientific Conference "Plants and Microbes: the Future of Biotechnology". PLAMIC2020 Organizing committee, 2020. http://dx.doi.org/10.28983/plamic2020.282.
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The biofilms of the bacteria A. brasilense and A. lipoferum are resistant to salt (over 400 mM NaCl in the medium) and temperature (up to 48° C) stresses. The nature of resistance to these stressors is determined by the type of biofilm.
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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.
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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.
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Gourgues, Sarah, Marisol Goñi Urriza, Patrick Baldoni-Andrey, Nicholas Gurieff, Clémentine Gelber e Séverine Le Faucheur. "Effects of cobalt on river biofilms: colonization kinetics and biofilm structure". In Goldschmidt2023. France: European Association of Geochemistry, 2023. http://dx.doi.org/10.7185/gold2023.18336.
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Kostenko, Victoria, M. Mehdi Salek, Mohammad A. Boraey, Michael G. Surette e Robert J. Martinuzzi. "Escherichea coli Biofilm Formation and Susceptibility in Response to Increased Shear Stresses". In ASME 2008 Summer Bioengineering Conference. American Society of Mechanical Engineers, 2008. http://dx.doi.org/10.1115/sbc2008-193009.
Testo completoAbstract (sommario):
The development of biofilms, well organized communities of bacterial cells embedded in a self-generated extra-cellular polymeric matrix, on medical devices (vascular or urinary catheters, surgical implants) and surrounding tissue poses a great challenge for modern medicine. The biofilm environment confers onto bacterial cells resistance to antimicrobials and the host immune system that leads to persistent and recurrent device-associated infections, deterioration of patient life quality, and often replacement of the device [1].
Rapporti di organizzazioni sul tema "Biofilms"
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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.
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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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Goldman, Graham. Biofilms in the oral cavity. Ames (Iowa): Iowa State University, gennaio 2018. http://dx.doi.org/10.31274/cc-20240624-299.
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Sridhar, Yang e Song. 4VRVLN6 Effects of Solids and Biofilms on Dewpoint and Corrosion in Pipelines. Chantilly, Virginia: Pipeline Research Council International, Inc. (PRCI), gennaio 2008. http://dx.doi.org/10.55274/r0011265.
Testo completoAbstract (sommario):
Internal corrosion occurs where water or other corrosive electrolyte accumulates. This is the principle used in Internal Corrosion Direct Assessment (ICDA). Although ICDA focuses on nominally dry gas with episodes of water upset, the well accepted criteria for dry gas (e.g., water less than 7 lb/MMCF) may be significantly influenced by the presence of bacterial biofilms and hygroscopic solids, such as iron oxide corrosion products and some salts. Therefore, understanding the changes in dew point induced by the presence of these compounds is necessary to better quantify gas quality requirements. The Multielectrode Array Sensor (MAS) probe, originally developed and patented by SwRI was used to study the effect of biofilms and corrosion products on corrosion in high pressure gas mixtures. The project demonstrated that: (i) the MAS probe is sensitive in detecting localized corrosion in wet gas streams at pipeline pressures; (ii) the corrosion rate is sensitive to gas composition/quality; (iii) the presence of biofilm and corrosion products affected the dew point but the current water content specifications for gas are sufficiently conservative that this decrease in dew point is not a concern; and (iv) the corrosion under the biofilm once initiated at high humidity levels did not decrease even upon decrease of humidity to levels lower than needed to initiate corrosion.
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Top, Eva M., e Ben Ridenhour. Persistence of Antibiotic Resistance Plasmids in Biofilms. Fort Belvoir, VA: Defense Technical Information Center, ottobre 2014. http://dx.doi.org/10.21236/ada614277.
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Allen, Herbert B. The Presence of Biofilms in Gouty Tophi. Science Repository OÜ, marzo 2019. http://dx.doi.org/10.31487/j.cmr.2018.01.007.
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Top, Eva M., e Silvia E. Smith. Persistence of Antibiotic Resistance Plasmids in Biofilms. Fort Belvoir, VA: Defense Technical Information Center, ottobre 2013. http://dx.doi.org/10.21236/ada615372.
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Camper, Anne K. Health Implications of Biofilms in Drinking Water Systems. Fort Belvoir, VA: Defense Technical Information Center, maggio 2009. http://dx.doi.org/10.21236/ada509095.
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Brynildsen, Mark P., Stephanie M. Amato, Christopher H. Fazen, Theresa Henry, Mehmet A. Orman, Elizabeth L. Sandvik e Katherine Volzing. Investigating Metabolic Control of Persister Formation in Biofilms. Fort Belvoir, VA: Defense Technical Information Center, ottobre 2013. http://dx.doi.org/10.21236/ada595099.
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Olson, Tyler. Biofilms and Their Consequences in the Oral Cavity. Ames (Iowa): Iowa State University, gennaio 2019. http://dx.doi.org/10.31274/cc-20240624-298.
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Heather Richard, Heather Richard. Are biofilms responsible for heavy metals on plastic debris? Experiment, giugno 2014. http://dx.doi.org/10.18258/2743.
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