Academic literature on the topic 'Enterococcus faecalis; biofilm; pH'
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Journal articles on the topic "Enterococcus faecalis; biofilm; pH"
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Spiegelman, Lindsey, Adrian Bahn-Suh, Elizabeth T. Montaño, Ling Zhang, Greg L. Hura, Kathryn A. Patras, Amit Kumar, et al. "Strengthening of enterococcal biofilms by Esp." PLOS Pathogens 18, no. 9 (September 14, 2022): e1010829. http://dx.doi.org/10.1371/journal.ppat.1010829.
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Multidrug-resistant (MDR) Enterococcus faecalis are major causes of hospital-acquired infections. Numerous clinical strains of E. faecalis harbor a large pathogenicity island that encodes enterococcal surface protein (Esp), which is suggested to promote biofilm production and virulence, but this remains controversial. To resolve this issue, we characterized the Esp N-terminal region, the portion implicated in biofilm production. Small angle X-ray scattering indicated that the N-terminal region had a globular head, which consisted of two DEv-Ig domains as visualized by X-ray crystallography, followed by an extended tail. The N-terminal region was not required for biofilm production but instead significantly strengthened biofilms against mechanical or degradative disruption, greatly increasing retention of Enterococcus within biofilms. Biofilm strengthening required low pH, which resulted in Esp unfolding, aggregating, and forming amyloid-like structures. The pH threshold for biofilm strengthening depended on protein stability. A truncated fragment of the first DEv-Ig domain, plausibly generated by a host protease, was the least stable and sufficient to strengthen biofilms at pH ≤ 5.0, while the entire N-terminal region and intact Esp on the enterococcal surface was more stable and required a pH ≤ 4.3. These results suggested a virulence role of Esp in strengthening enterococcal biofilms in acidic abiotic or host environments.
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Hakiki, Dalhar, Latief Mooduto, Ketut Suardita, and Dian Agustin Wahjuningrum. "Effectiveness of flavonoid from mangosteen pericarp (Garcinia mangostana L.) as Enterococcus faecalis antibiofilm." Conservative Dentistry Journal 7, no. 1 (September 27, 2019): 18. http://dx.doi.org/10.20473/cdj.v7i1.2017.18-22.
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Background:Enterococcus faecalis (E. faecalis) is a microorganism that is commonly found in endodontic failure treatment, this due to several characteristics of E.faecalis which has the capabillity to living in environments with high salt levels, high temperature, and pH broad spectrum. Bacteria in biofilms form is one of the adaptive process that allows bacteria to survive in an environment with low nutrients in the root canals. Bacteria in biofilms form have different characteristics from planktonic form, resistance to phagocytic cells and drugs, which can effect to persistent infection. Mangosteen (Garcinia mangostana) has many benefits, especially on the pericarp of the fruit contains alkaloids, tannins, phenolics, flavonoids, and triterpenoids. Flavonoids are the largest group of phenolic compounds that have a nature effectively inhibit the growth of viruses, bacteria, and fungi. Purpose:Purpose of this study wasto find out the role of the antibiofilm of the flavonoid in garcinia mangostana pericarp against E. faecalis bacterial biofilm. Methods:Laboratory experimental in-vitro with post test only group design. The method used is microtitter plate biofilm assay and continued with the readings use Elisa reader at a wavelength of 595 nm. Results:Flavonoids mangosteen pericarp effective as antibiofilm E.faecalis bacteria at a concentration of 12.5%. Conclusion:The study showed that flavonoids from mangosteen pericarp has antibiofilm activity against E. faecalis bacterial biofilm.
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Ridhalaksani, Ridzki, Kamizar Nazar, Nila Kesuma Djauharie, Ratna Meidyawati, and Dewa Ayu Npa. "THE ANTIBACTERIAL POTENTIAL OF N-ACETYLCYSTEINE AS AN ENDODONTIC IRRIGANT ON THE CLINICAL ISOLATES OF THE ENTEROCOCCUS FAECALIS BIOFILM." International Journal of Applied Pharmaceutics 9 (January 1, 2018): 17. http://dx.doi.org/10.22159/ijap.2017.v9s2.05.
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Objective: The aim of this study was to evaluate the antibacterial potential of NAC as an endodontic irrigant on the clinical isolates of the Enterococcus faecalis biofilm.Methods: NAC with a pH of 2.5 and 11 (NAC pH 2.5 and NAC pH 11, respectively) were exposed to clinical isolates of E. faecalis biofilms for 1 min. The NAC samples were compared to 2% chlorhexidine (CHX), which is commonly used as an irrigant in persistent infections. The antibacterial potential of these irrigants was evaluated by comparing the bacterial count of the E. faecalis colonies after they were exposed to the irrigants.Results: The NAC pH 2.5 test group showed a reduction in the E. faecalis colonies, but this reduction was not statistically significant when compared to the 2% CHX group results. The NAC pH 11 test group showed the greatest reduction in bacterial colonies, and this reduction was statistically significant when compared to the NAC pH 2.5 and 2% CHX groups’ results.Conclusion: NAC pH 11 has antibacterial potential on the clinical isolates of E. faecalis biofilms.
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Zhan, Xiangjun, Yingzhu Tan, Yingmei Lv, Jianing Fang, Yuanjian Zhou, Xing Gao, Huimin Zhu, and Chao Shi. "The Antimicrobial and Antibiofilm Activity of Oregano Essential Oil against Enterococcus faecalis and Its Application in Chicken Breast." Foods 11, no. 15 (August 1, 2022): 2296. http://dx.doi.org/10.3390/foods11152296.
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Oregano essential oil (OEO) possesses anti-inflammatory, antioxidant, and cancer-suppressive properties. Enterococcus faecalis is a foodborne opportunistic pathogen that can be found in nature and the food processing industry. The goal of this investigation was to explore the antimicrobial action and mechanism of OEO against E. faecalis, inactivation action of OEO on E. faecalis in mature biofilms, and its application in chicken breast. The minimum inhibitory concentration (MIC) of OEO against E. faecalis strains (ATCC 29212 and nine isolates) ranged from 0.25 to 0.50 μL/mL. OEO therapy reduced intracellular adenosine triphosphate (ATP) levels, caused cell membrane hyperpolarization, increased the intracellular reactive oxygen species (ROS), and elevated extracellular malondialdehyde (MDA) concentrations. Furthermore, OEO treatment diminished cell membrane integrity and caused morphological alterations in the cells. In biofilms on stainless-steel, OEO showed effective inactivation activity against E. faecalis. OEO reduced the number of viable cells, cell viability and exopolysaccharides in the biofilm, as well as destroying its structure. Application of OEO on chicken breast results in a considerable reduction in E. faecalis counts and pH values, in comparison to control samples. These findings suggest that OEO could be utilized as a natural antibacterial preservative and could effectively control E. faecalis in food manufacturing.
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Askora, Ahmed, Mohamed El-Telbany, Gamal El-Didamony, Eman Ariny, and Momen Askoura. "Characterization of φEf-vB1 prophage infecting oral Enterococcus faecalis and enhancing bacterial biofilm formation." Journal of Medical Microbiology 69, no. 9 (September 1, 2020): 1151–68. http://dx.doi.org/10.1099/jmm.0.001246.
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Introduction. Enterococcus faecalis is a facultative, anaerobic, opportunistic pathogen associated with medical and dental diseases. Bacterial phenotypic traits and pathogenesis are often influenced by lysogeny. Aim. The aim of this study was to characterize both the morphology and complete genome sequences of induced prophages purified from E. faecalis clinical isolates. Methodology. E. faecalis isolates were recovered from the roots of teeth of patients attending an endodontic clinic. The morphological features of isolated phage were characterized using transmission electron microscopy (TEM). DNA sequencing was performed using the Illumina MiSeq platform. Results. TEM indicated that the isolated φEf-vB1 prophage belongs to the family Siphoviridae. The φEf-vB1 prophage was stable over a wide range of temperatures and pH. Sequencing of φEf-vB1 DNA revealed that the phage genome is 37 561 bp in length with a G+C content of 37.6mol% and contained 53 ORFs. Comparison with previously predicted prophage genomes using blast revealed that φEf-vB1 has a high sequence similarity to previously characterized phage genomes. The lysogenic E. faecalis strain exhibited a higher biofilm formation capacity relative to the non-lysogenic strain. Conclusion. The current findings highlight the role of lysogeny in modification of E. faecalis properties and reveal the potential importance of prophages in E. faecalis biology and pathogenesis.
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Zancan, Rafaela Fernandes, Bruno Cavalini Cavenago, Denise Ferracioli Oda, Clovis Monteiro Bramante, Flaviana Bombarda de Andrade, and Marco Antonio Hungaro Duarte. "Antimicrobial Activity and Physicochemical Properties of Antibiotic Pastes Used In Regenerative Endodontics." Brazilian Dental Journal 30, no. 6 (November 2019): 536–41. http://dx.doi.org/10.1590/0103-6440201902613.
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Abstract: The purpose of this study was to evaluate the pH, solubility and antimicrobial action of Calcium Hydroxide Paste (CH), Double Antibiotic Paste (metronidazole+ciprofloxacin-DAP), calcium hydroxide added to DAP (CH/DAP) and Triple Antibiotic Paste (metronidazole + ciprofloxacin+minocycline-TAP). pH (n=10) were measured by pHmeter. Root canals of acrylic teeth (n=10) were filled with the above-mentioned intracanal-dressings, immersed in ultrapure water, and solubility was measured by the difference between the initial and final volume (7,15 and 30 days) by using micro-computed tomography. Enterococcus faecalis biofilm was induced on bovine dentin disc surfaces (n=20), and treated with the pastes for 7 days. Percentage bacterial viability was verified by confocal microscope, with LIVE/DEAD dye. CH and CH/DAP presented the highest pH values. Regarding solubility, after 7 days, antibiotic groups presented significant volume loss. CH and CH/DAP showed no statistical difference compared with the Control in antimicrobial action against E. faecalis biofilm. However, TAP and DAP presented a significant percentage reduction in bacterial population. Due to high solubility of the pastes, renewing antibiotic dressings every 7 days, or using the medications for this period in regeneration protocols is recommended. DAP is indicated for killing E. faecalis in biofilm because it has antimicrobial action similar to TAP. Adding Calcium Hydroxide to DAP significantly decreased its antimicrobial action. In spite of its the low solubility and high pH values, the CH paste showed a low level of antimicrobial action against E. faecalis in biofilm.
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Zainal, Fatin Faqihah, Nur Syafiqah Syamimi Suhaimi Suzey, Norzawani Jaffar, and Chew Ching Hoong. "The Influence of Lactobacillus Species on Nosocomial Pathogens’ Biofilm." Asian Journal of Medicine and Biomedicine 6, S1 (November 10, 2022): 178–80. http://dx.doi.org/10.37231/ajmb.2022.6.s1.578.
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The word probiotic comes from the Latin meaning "for life”. Lactic acid, acetic acid, and propionic acid are produced by bacteria such as Lactobacillus and Bifidobacterium. Such compounds lower the pH and prevent pathogenic bacteria from multiplying [1]. When the adhesion force between the attachment surfaces is stable, the bacteria cell communication system, called the quorum sensing (QS) system, is triggered. Bacteria use these signaling molecules to regulate virulence factors, secondary metabolite synthesis, biofilm formation, and communication with the host and other microbes depending on population density [2]. The aim of this study is to observe the potential use of probiotics against nosocomial pathogens' biofilms (Staphylococcus aureus, Klebsiella pneumoniae, Pseudomonas aeruginosa and Enterococcus faecalis).
The objective of the study is to identify the interactions between probiotics Lactobacillus and nosocomial pathogens, to observe the ability of Lactobacillus spp. to degrade the mature biofilm of nosocomial pathogens and to assess the influence of pH on the biofilm degradation activity of Lactobacillus spp. by using agar-well diffusion method and biofilm degradation assay [3].
All pathogens had no zone of inhibition on MHA for pH-adjusted LAB-CFS. The zone of inhibition (ZOI) can be seen in Table 1. No ZOI was observed for LAB-CFS against E. faecalis ATCC 29212. All zones made by the unadjusted pH of LAB-CFS on the tested pathogens showed high ZOI were more than 10 mm in diameter which indicate that the LAB-CFS have substances that produce an antibacterial effect [4]. No antibacterial activity was observed when the CFS pH was adjusted to almost neutral.
In Figure 1, unadjusted pH of LAB-CFS for LF 37 shows the highest percentage of biofilm degradation in K. pneumoniae ATCC 13883 (50.88%) and unadjusted pH of LAB-CFS for LC 83, P. aeruginosa ATCC 17934 (21.88%) shows the lowest percentage of degradation. In Figure 2, the pathogen that shows the highest percentage of degradation using adjusted pH of LAB-CFS for LF 37 is K. pneumoniae ATCC 13883 (69.72%). The lowest percentage of degradation when using adjusted pH LAB-CFS for LC 83 is E. faecalis ATCC 29212 (25.77%). Since the percentage of biofilm degradation is higher in neutralized LAB-CFS, according to [5], sodium lactate, a neutralised form of lactic acid, or other novel low molecular weight active compounds could explain the antimicrobial or anti-biofilm activity.
In conclusion, the unadjusted pH of LAB-CFS contains substances that can be used as antimicrobial and antibiofilm. However, the adjusted pH of LAB-CFS can only be used as antibiofilm but not as antimicrobial. This is because only the unadjusted pH of LAB-CFS produced a zone of inhibition in the agar well diffusion method. This is probably due to the acidic condition of LAB-CFS itself. For biofilm degradation, both adjusted and unadjusted pH of LAB-CFS were able to degrade mature biofilm, but the adjusted pH of LAB-CFS showed more biofilm degradation activity suggesting that low pH of LAB-CFS did not contribute to the biofilm degradation.
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Wigler, Ronald, Shlomo Matalon, Tomer Goldberger, Anat Or Lerner, and Anda Kfir. "Enhanced Bactericidal Efficacy of NaOCl at pH 12 Followed by Acidified NaOCl at pH 6.5 on Enterococcus faecalis Biofilm." Applied Sciences 10, no. 17 (September 2, 2020): 6096. http://dx.doi.org/10.3390/app10176096.
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This study aimed to determine the bactericidal efficacy of sequential use of NaOCl pH 12 followed by acidified NaOCl pH 6.5, and compare it to that of either of these NaOCl solutions alone. E. faecalis biofilm was grown on standardized dentine specimens for four weeks. The specimens were randomly divided into four groups: (A) 4 min exposure to 0.9% saline solution (control); (B) 4 min exposure to 4% NaOCl pH 12; (C) 4 min exposure to 4% NaOCl pH 6.5; and (D) 2 min exposure to 4% NaOCl pH 12 followed by 2 min exposure to 4% NaOCl pH 6.5. The bactericidal activity was evaluated after the 4 min of contact time using confocal laser scanning microscopy. The volume ratio of red fluorescence to green and red fluorescence indicated the proportion of dead cells in the biofilm. The percent of dead cells in the saline solution group was significantly lower than those in the other groups. There was no significant difference between NaOCl pH 12 compared to NaOCl pH 6.5. The sequential use of NaOCl pH 12 followed by pH 6.5 significantly increased the percent of dead cells compared to both the samples exposed to either NaOCl pH 12 or pH 6.5. These results show that sequential irrigation protocol had a stronger bactericidal effect than the commonly used NaOCl pH 12.
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van Merode, Annet E. J., Henny C. van der Mei, Henk J. Busscher, Karola Waar, and Bastiaan P. Krom. "Enterococcus faecalis strains show culture heterogeneity in cell surface charge." Microbiology 152, no. 3 (March 1, 2006): 807–14. http://dx.doi.org/10.1099/mic.0.28460-0.
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Adhesion of micro-organisms to biotic and abiotic surfaces is an important virulence factor and involves different types of interactions. Enterococcus faecalis, a human commensal and an important opportunistic pathogen, has the ability to adhere to surfaces. Biliary stents frequently become clogged with bacterial biofilms, with E. faecalis as one of the predominant species. Six E. faecalis strains isolated from clogged biliary stents were investigated for the presence of specific biochemical factors involved in their adhesion: aggregation substances (Aggs) and the enterococcal surface protein (encoded by the esp gene). In addition, physico-chemical factors involved in adhesion (zeta potential and cell surface hydrophobicity) were determined, as well as the influence of ox bile on these properties. Two-thirds of the biliary stent isolates displayed culture heterogeneity in the pH dependence of their zeta potentials. Moreover, 24 out of 46 clinical isolates of E. faecalis, including 11 laboratory strains, also displayed such heterogeneity. The culture heterogeneity was demonstrated to be a stable trait, not caused by quorum sensing, not plasmid mediated, and independent of the presence of esp and Agg. Data presented show that culture heterogeneity in zeta potential enhances adhesion to an abiotic surface. A higher prevalence of culture heterogeneity in zeta potential in pathogenic as compared to non-pathogenic isolates could indicate that this phenomenon might play a role in virulence and putatively in pathogenesis.
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Akaluka, Cynthia K., Justinah C. Orji, Wesley Braide, Emmanuel Egbadon, and Samuel A. Adeleye. "Abattoir Wastewater Treatment and Energy Recovery Using a Ferricyanide-Catholyte Microbial Fuel Cell." International Letters of Natural Sciences 55 (June 2016): 68–76. http://dx.doi.org/10.18052/www.scipress.com/ilns.55.68.
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The capacity of Microbial fuel cells (MFCs) to produce voltage and concurrently treat abattoir waste water was investigated in MFCs that used 0.1M potassium ferricyanide (K3[Fe(CN)6] as catholytes. Physicochemical, electrochemical and Microbiological properties of the MFCs were monitored. The open circuit voltage (OCV) readings were taken at 3 hours interval and maximum OCV of 965mV was recorded. Also, The physicochemical characteristics of the MFCs revealed that the pH decreased by 0.2 after treatment; Chemical Oxygen demand, biochemical oxygen demand, total suspended solids, ammonia, and total nitrogen reduced by 88.4%, 65.56%, 43.88%, 60% and 60% respectively. However, Phosphate increased by 54%. The bacterial isolates from the raw abattoir wastewater were Staphylococcus aureus, Bacillus cereus, Bacillus subtilis, Enterococcus faecalis, Enterobacter aerogenes, Escherichia coli and Micrococcus luteus while Enterococcus faecalis, Bacillus cereus and Escherichia coli were isolated from the biofilms on the anode. Microbial fuel cells therefore have capacities for simultaneous waste water treatment and electricity generation.
Dissertations / Theses on the topic "Enterococcus faecalis; biofilm; pH"
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Tse, Chee-choong Micheal, and 謝志聰. "Effect of ultrasonic agitation on enterococcus faecalis biofilm." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2010. http://hub.hku.hk/bib/B45165993.
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Chittezham, Thomas Vinai. "The molecular control and biological implications of autolysis in enterococcus faecalis biofilm development." Diss., Manhattan, Kan. : Kansas State University, 2009. http://hdl.handle.net/2097/1519.
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Schurig, Tilman David [Verfasser], and Karl-Thomas [Akademischer Betreuer] Wrbas. "Der antibakterielle Effekt verschiedener Wurzelkanalfülltechniken auf Enterococcus faecalis – Biofilm in humanen Wurzelkanälen in vitro." Freiburg : Universität, 2016. http://d-nb.info/112274336X/34.
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Yang, Nan. "Role of Escherichia coli curli in relation with intestinal components - mucin, Klebsiella pneumoniae and Enterococcus faecalis." Phd thesis, INSA de Lyon, 2011. http://tel.archives-ouvertes.fr/tel-00657247.
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Bacteria in nature mostly exist in biofilms, which are structured adherent communities encased in polymeric matrices. In the human body, most biofilms are composed of commensal microorganisms with the gastrointestinal tract being the most heavily colonized site. Bacterial attachment to the overlying mucus gel layer of the intestinal epithelium is fundamental to the establishment of a stable commensal microflora. However the interaction of bacteria with the complex mucus gel is poorly described. Moreover, the complexity and diversity of the gut microbiota is itself an obstacle to studying its biology. Microbiota functions are the product of communities of bacteria and interactions between multiple species. New approaches are needed to study this aspect of even the most well-studied member of the human gut microbiota, Escherichia coli. This thesis was devoted to the exploration of the transcriptional response of E. coli facing different elements of human gut following 3 main objectives. First, the initial part of my work was related to the conception and optimization of appropriate genetic tools to both track E. coli within the multispecies context that constitute human gut commensals, and survey the expression of genes of interest. Use of the Green Fluorescent Protein (GFP) genes allowing enhanced fluorescence and shortened half-life has permitted significant progress both in whole cell tagging as well as transcriptional reporting, while the red fluorescent counterparts were disappointing. Second, using the subset of tools that has been validated to be reliable, influence of mucin on the biofilm formation ability of E. coli has subsequently been studied. I have shown that mucin promotes E. coli biofilm formation through transcriptional modulation of surface adhesion structures such as curli and type 1 pili. Third, concurrently, E. coli's population relationship to commensal bacteria (K. pneumoniae and E. faecalis) was investigated and demonstrated, with the possible influence of surface adhesion structures such as curli as the biological focus. The results suggest that curli production in biofilm increases the fitness of E. coli when co-cultured with K. pneumoniae while promoting synergistic interaction between E. coli and E. faecalis. The implication based on the data is discussed. This work improves the understanding of E. coli response to the gut environment, and provides foundations to build more powerful tools for further investigations.
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Castro, Pedro Coimbra de Almeida Osório de. "Biofilmes em endodontia." Master's thesis, [s.n.], 2014. http://hdl.handle.net/10284/4386.
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Projeto de Pós-Graduação/Dissertação apresentado à Universidade Fernando Pessoa como parte dos requisitos para obtenção do grau de Mestre em Medicina DentáriaIntrodução: Um biofilme é uma comunidade estruturada de células bacterianas envolvidas numa matriz constituída por substâncias poliméricas e aderido a uma superfície sólida. Esta comunidade permite um modo protegido de crescimento que permite a sobrevivência dos constituintes celulares em ambientes hostis e fornece uma tolerância aumentada a agentes antimicrobianos. Objectivo: Tentar compreender a forma como os constituintes celulares se organizam e ter um melhor conhecimento das formas de resistência antimicrobiana características da organização em biofilmes, como também de rever os métodos actualmente usados para a desinfecção no tratamento endodôntico e abordando métodos alternativos ainda em estudo. Materiais e métodos: Para tal realizou-se uma pesquisa bibliográfica nos principais motores de busca: Pubmed, B-On, SciELO, Science Direct, como também no repositório da Universidade Fernando Pessoa e da Faculdade de Medicina Dentária do Porto utilizando as palavras-chave “Biofilms”, “Apical Periodontitis”, “Enterococcus faecalis” e “Biofilm Treatment “ que foram associadas de várias formas. Desta pesquisa efectuada, entre Junho de 2014 e Julho de 2014, foram escolhidos 117 artigos em Português e Inglês dos quais foram usados 89. Resultados: A forma como actualmente procedemos à desinfecção do sistema de canais radiculares, passando pela instrumentação mecânica e irrigação química não é totalmente satisfatória no que toca a uma total erradicação dos microorganismos devido a várias limitações como a complexidade anatómica dos canais e a ecologia presente no interior dos mesmos. Conclusões: De futuro, terão que ser desenvolvidas outras estratégias antimicrobianas para suplementar as existentes. Embora estas pareçam promissoras in vitro elas carecem de estudos in vivo, os quais serão necessários no futuro para ultrapassar as várias limitações presentes no sistema de canais radiculares. Introduction: A biofilm is a structured bacterial cell community enveloped in a matrix composed of polymeric substances and attached to a solid surface. This community allows for a protected way of growth that permits the survival of the cellular components in hostile environments and provides a higher tolerance to antimicrobial agents. Objective: Trying to understand the way cellular components are organized and have a better knowledge of the antimicrobial resistances that are characteristic of the way biofilms are structured, as well as to review the currently used methods for disinfection in an endodontic treatment and to address alternative methods still in study. Materials and Methods: To this end a bibliographic research was performed on the main search engines: Pubmed, B-On, SciELO, Science Direct, and also on Universidade Fernando Pessoa and Faculdade de Medicina Dentária do Porto’s repository using “Biofilms”, “Apical Periodontitis”, “Enterococcus faecalis” and “Biofilm Treatment“ as key-words that were associated in many forms. From this research performed between June 2014 and July 2014, were selected 117 articles in Portuguese and English and from those, 89 were used. Results: The way that we currently proceed regarding the disinfection of the root canal system using mechanical instrumentation and chemical irrigation is not fully satisfactory, when it comes to the total eradication of the microorganisms present due to several limitations like the complexity of the root canal anatomy and the ecology present inside the root canal. Conclusions: In the future, other antimicrobial strategies will have to be developed to supplement the currently used ones. Although these look promising in vitro they lack in vivo studies, that will be necessary in the future to overcome the several limitations present in the root canal system.
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Iyer, Vijayalakshmi Subramanian. "Role of the transcription regulator RpoN (sigma 54) in Enterococcus faecalis biofilm development, metabolism and virulence." Diss., Kansas State University, 2012. http://hdl.handle.net/2097/17150.
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Doctor of PhilosophyDepartment of Biology
Lynn Hancock
Enterococci are the third leading cause of nosocomial infections including urinary tract infections (UTI), surgical site infections (SSI) and blood stream infections. Enterococci are also found in the gastrointestinal tracts of humans, and other mammals. We elucidated the influence of the transcriptional regulator RpoN on enterococcal biofilm formation, virulence potential and cell wall architecture and proposed a potential involvement for carbohydrate metabolism in these processes. Biofilms are held together by matrix (BM) components such as extracellular DNA (eDNA) released by cell death from a sub-population of cells. The rpoN mutant (ΔrpoN) was resistant to autolysis as well as fratricide-mediated cell death and eDNA was not detected in planktonic as well as biofilm cultures. Unlike the parental strain V583, the ΔrpoN mutant formed proteinase K sensitive biofilms, suggesting that protein as well as eDNA serves as an important matrix component. The rabbit model of endocarditis was used to assess the effect of rpoN deletion on enterococcal virulence. Rabbits infected with ΔrpoN had reduced bacterial burden in heart, blood, liver, kidney and vegetation in comparison to the parental strain. The growth defect of ΔrpoN in physiologically relevant glucose levels (5 mM) partially explains the reduced bacterial burdens observed in the virulence study. Microarray analysis of ΔrpoN showed that 10% of the genome is differentially regulated by RpoN. Deletion of rpoN also protects Enterococcus faecalis from lysis in the absence of known modulators of cellular lytic events such as O-acetylation and D-alanylation. Of the four identified enhancer binding proteins in E. faecalis, MptR regulates the RpoN-dependent mannose/glucose uptake system (MptABCD) and the ΔmptR mutant phenocopied the ΔrpoN mutant in the eDNA release and growth assays. Because MptC and MptD have been shown to be the cellular receptors for class IIa and IIc bacteriocins, we are presently testing the hypothesis that these receptors may serve as a global receptor for bacteriocins. In conclusion, our data demonstrates that alterations in the metabolic state of the bacterium, as observed in the ΔrpoN mutant could be responsible for the switch in biofilm matrix composition, and this switch in turn likely influences the virulence potential of the bacterium.
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Alves, Denise Ramos Silveira. "Efeito da terapia fotodinâmica sobre biofilme de Enterococcus faecalis e estrutura dentinária." Universidade Federal de Goiás, 2016. http://repositorio.bc.ufg.br/tede/handle/tede/6229.
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Objective: Evaluate the effect of photodynamic therapy (PDT) on Enterococcus faecalis biofilm in infected root canals and on dentin structure. Methods: Twenty-one root canals of a sample of 24 extracted single-rooted human teeth were infected by E. faecalis for 60 days to form biofilm. The antimicrobial strategies tested were (n=3 in each group): root canal preparation using NiTi rotary instruments, 2.5% NaOCl and 17% EDTA irrigation, and PDT with 0.01% methylene blue (group I) or 0.01% malachite green (group II); root canal preparation using NiTi rotary instruments, 2.5% NaOCl and 17% EDTA irrigation, and PDT with 0.01% methylene blue (group III); PDT with 0.01% methylene blue without root canal preparation (group IV); root canal preparation using NiTi rotary instruments, 22.5% NaOCl and 17% EDTA irrigation, and no PDT (group V); 2.5% NaOCl irrigation with no root canal preparation, and 17% EDTA irrigation (group VI); positive control (group VII). Three roots were not infected and were used as negative controls (group VIII). Samples for microbiological tests were collected using three sterile paper points, later stored in BHI and incubated at 37o C for 48 hours at three time points: before (S1) and after (S2) root canal preparation, and after PDT application (S3). Bacterial growth was analyzed according to turbidity of culture medium, presence of bacteria, and spectrophotometric optical density (nm). Specimens were sectioned and prepared for SEM analysis of dentin structure. Results: Bacteria were found at S1, S2 and S3 in all experimental groups. Optical density of culture media at S2 and S3 in groups I, II and III were lower than at S1, but not statistically different. Optical density of culture media at S2 was 28.70% and 24.67% lower than at S1 in groups I and II; after PDT, optical density was 90.00% (group I) and 37.30% (group II) lower. In group III, it was 97.70% lower at S2 and an additional 92.00% lower after PDT. In group IV, optical density increase 3.2%. Dentin analysis after PDT revealed areas of melting and recrystallization, peritubular dentin projections, intertubular dentin erosion and fusion of dentinal tubule openings, which made dentin surface irregular. Some dentinal tubules were obliterated, and there were changes in the shape of their openings. Conclusion: PDT applied after root canal preparation using manual or rotary files was not effective in eliminating E. faecalis completely. PDT changed dentin structure and resulted in dentin melting and recrystallization, as well as in dentinal tubule erosion and obliteration.
Objetivo: Avaliar o efeito da terapia fotodinâmica sobre biofilme de Enterococcus faecalis em canais radiculares infectados e sobre a estrutura dentinária. Metodologia: O estudo foi desenvolvido em vinte e quatro dentes humanos unirradiculares extraídos, dos quais vinte e um canais radiculares foram infectados com E. faecalis por 60 dias para formação de biofilme. As estratégias antimicrobianas testadas foram (n=3): preparo do canal radicular com instrumentos rotatórios de NiTi/ NaOCl 2,5%/ irrigação final EDTA 17%, e TFD com azul de metileno 0,01% (Grupo I) ou verde malaquita 0,01% (Grupo II); preparo do canal radicular com instrumentos manuais de aço inox/ NaOCl 2,5%/ irrigação final EDTA 17% e TFD com azul de metileno 0,01% (Grupo III); TFD com azul de metileno 0,01% sem preparo prévio do canal radicular (Grupo IV); preparo do canal radicular com instrumentos rotatórios de NiTi/ NaOCl 2,5%/ irrigação final EDTA 17% sem emprego da TFD (Grupo V); irrigação com hipoclorito de sódio 2,5% sem preparo do canal radicular/ irrigação final EDTA 17% (Grupo VI); controle positivo (Grupo VII). Três espécimes não foram contaminados, sendo utilizados como controle negativo (Grupo VIII). Coletas microbiológicas foram realizadas, antes (CM1) e após (CM2) o preparo do canal radicular, e depois da aplicação da TFD (CM3), utilizando três pontas de papel absorventes esterilizadas, posteriormente armazenadas em BHI e a seguir , incubadas a 37o C por 48 horas. O crescimento bacteriano foi analisado pela turbidez do meio de cultura, sendo determinada a presença ou ausência de bactérias, e pela densidade óptica do meio de cultura, interpretada por espectrofotometria (nm). A seguir, os espécimes foram seccionados e preparados para análise da estrutura dentinária por meio de imagens de MEV. Resultados: A presença de bactérias foi verificada na CM1 , CM2 e CM3 de todos os grupos experimentais. As medidas da densidade óptica dos meios de cultura das CM2 e CM3 nos grupos experimentais I, II e III apresentaram redução quando comparada a CM1, porém não significativa estatisticamente. Nos Grupos I e II a densidade óptica do meio de cultura foi reduzida em 28.70% e 24,67% em CM2, respectivamente. Após a TFD, a redução da densidade óptica foi 90,00% (Grupo I) e 37,70% (Grupo II). No Grupo III, a redução da densidade óptica do meio de cultura foi de 97,70% na CM2, com redução adicional de 92,00% após TFD. No Grupo IV foi verificado aumento da densidade óptica do meio de cultura em 3,2%. A análise da dentina evidenciou, nos grupos submetidos à TFD, áreas de derretimento e recristalização, projeção da dentina peritubular, e regiões com erosão da dentina intertubular e união das entradas dos túbulos dentinários, tornando a superfície dentinária irregular. Obliteração de túbulos dentinários com alteração do contorno de suas entradas também foi verificada. Conclusão: A TFD, após preparo do canal radicular com sistema rotatório ou manual, não foi efetiva na eliminação completa de E. faecalis, e alterou a estrutura dentinária, determinando derretimento e recristalização de dentina, erosão e obliteração de túbulos dentinários.
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Rosa, Ricardo Abreu da. "Efetividade da terapia fotodinâmica associada à soluções irrigadoras frente a dois modelos de biofilme." reponame:Biblioteca Digital de Teses e Dissertações da UFRGS, 2015. http://hdl.handle.net/10183/144218.
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O objetivo deste estudo foi avaliar o efeito antibacteriano e a dissolução de biofilme promovido pela terapia fotodinâmica (PDT) associada com o hipoclorito de sódio (NaOCl) 2,5% e a clorexidina (CHX) sobre biofilmes mono-espécie e multi-espécies. No modelo de biofilme mono-espécie, quarenta e seis prémolares inferiores foram contaminados com cepas de Enterococcus faecalis (ATCCC 29212) por 21 dias. Os espécimes foram divididos em três grupos de acordo com a solução irrigadora utilizada: soro fisiológico, CHX 2% e NaOCl 2,5%. Após irrigação com 5 mL de cada irrigante, a PDT foi realizada. Amostras foram coletadas previamente aos protocolos de irrigação (S1), após irrigação (S2) e após PDT (S3). No modelo de biofilme multi-espécies, sessenta blocos de dentina bovina foram infectados intraoral e divididos em seis grupos: soro fisiológico, soro fisiológico/PDT, CHX, CHX/PDT, NaOCl e NaOCl/PDT. Microscopia confocal a laser foi usada para avaliar a porcentagem e o biovolume de células vivas e o volume total de biofilme. Todos os grupos reduziram as contagens de UFCs após os procedimentos de irrigação (S1-S2); porém a CHX e o NaOCl promoveram as menores contagens de UFCs (P < 0,05). A PDT diminuiu significativamente a contagem bacteriana no grupo do soro fisiológico (S2-S3; P < 0,05). No modelo de biofilme multi-espécies, a menor quantidade de células vivas foi observada nos grupos CHX, CHX/PDT, NaOCl e NaOCl/PDT, sem diferenças entre si (P > 0,05). A PDT não reduziu o volume total de biofilme (P > 0,05); porém parece diminuir o biovolume e a quantidade de células vivas após irrigação com CHX 2% e NaOCl 2,5%. A terapia fotodinâmica associada ao soro fisiológico reduziu a carga bacteriana em canais infectados com E. faecalis. A PDT parece reduzir a quantidade e o volume de células vivas, mas não o volume total de células em biofilme multiespécies induzido in situ. Finalmente, o tipo de irrigante foi decisivo para dissolver biofilme multi-espécies.The aim of this study was to evaluate the antibacterial effect and the biofilm dissolution promoted by photodynamic therapy (PDT) associated with 2.5% NaOCl and 2% CHX over monospecies and multispecies biofilms. In monospecies biofilm model, forty-six mandibular premolars were contaminated with Enterococcus faecalis strains (ATCC 29212) broth culture for 21 days. Specimens were divided into three groups according to the irrigant used: saline, 2% of CHX and 2.5% of NaOCl. After irrigation with 5 mL of each irrigant, PDT was performed. Samples were collected at baseline (S1), after irrigation (S2) and after PDT (S3). In multispecies biofilm model, sixty bovine dentin blocs were infected intraorally, and divided into six groups: saline, saline/PDT, CHX, CHX/PDT, NaOCl and NaOCl/PDT. Confocal laser scanning microscopy was used to assess the percentage and the biovolume of live cells and the total biovolume. All groups reduced UFC’ counts after irrigation procedures (S1-S2); however CHX and NaOCl promoted the lowest UFCs counts (P < 0.05). PDT significantly reduced the bacterial counts in saline group (S2-S3; P < 0.05). In multispecies biofilm model, the lowest amount of live cells was observed in CHX, CHX/PDT, NaOCl and NaOCl/PDT groups, with no differences among them (P > 0.05). PDT did not reduce the total biovolume (P > 0.05); however it appears to decrease the biovolume and the amount of live cells after irrigation with 2% CHX and 2.5% NaOCl. PDT associated with saline reduced the bacterial load in canal infected with E. faecalis. PDT seems to reduce the amount and the biovolume of live cells, but did not reduce the total biovolume of cells in multispecies biofilm induced in situ. Finally, the irrigant was decisive to dissolve multispecies biofilm.
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Chettaoui, Rayane. "Activité anti-biofilm du cranberry et de l’un de ses métabolites envers Enterococcus faecalis dans un contexte d’infection urinaire." Thesis, Cergy-Pontoise, 2017. http://www.theses.fr/2017CERG0909.
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Escherichia coli et Enterococcus faecalis sont deux principaux agents pathogènes impliqués dans les infections du tractus urinaire (ITU) en médecine de ville et à l’hôpital. Ces espèces bactériennes sont responsables d’ITU aigües avec des phénomènes de récurrence et dans des ITU chroniques. La consommation d'antibiotiques est directement corrélée à la résistance des bactéries uropathogènes ce qui montre l'importance de contrôler l'utilisation des antibiotiques et de développer des traitements préventifs et curatifs alternatifs pour les infections urinaires.La consommation alimentaire de cranberry et de leurs extraits est traditionnellement associée avec le maintien en bonne santé des voies urinaires. Par ailleurs, certaines études cliniques semblent montrer un effet préventif des ITU associé à la consommation alimentaire de cranberry. In vitro et ex vivo, la consommation de ces extraits par l’homme réduit l’adhérence de certaines souches d’E. coli aux cellules épithéliales urinaires et la formation de biofilm de différentes espèces. L’hypothèse de travail est que la consommation alimentaire d’extraits de cranberry conduise à la formation de métabolites urinaires qui diminuent l'adhérence des bactéries uropathogènes à l’épithélium urinaire. Ce mécanisme serait à la base de la prévention des ITU par consommation d’extraits de cranberry. Cependant, les métabolites bioactifs restent largement méconnusEscherichia coli and Enterococcus faecalis are two main pathogens involved in urinary tract infections (ITU) in town medicine and in the hospital. These bacterial species are responsible for acute UTIs with recurrence phenomena and in chronic ITUs. The consumption of antibiotics is directly correlated with the resistance of uropathogenic bacteria, which shows the importance of controlling the use of antibiotics and of developing alternative preventive and curative treatments for urinary infections.Cranberry consumption of their extracts is traditionally associated with the maintenance of healthy urinary tract. In addition, some clinical studies seem to show a preventive effect of ITUs associated with cranberry consumption. In vitro and ex vivo, the consumption of these extracts by humans reduces the adhesion of certain E. coli strains to urinary epithelial cells and biofilm formation of different species. The working hypothesis is that the consumption of cranberry extracts leads to the formation of urinary metabolites that decrease the adhesion of uropathogenic bacteria to the urinary epithelium. This mechanism would be the basis for the prevention of ITU by consumption of cranberry extracts. However, bioactive metabolites remain largely unknown
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Ardalan, Cyrous. "A Comparative Study of Intraradicular Enterococcus Faecalis Biofilm Removal with Three Root Canal Treatment Systems: A Scanning Electron Microscopy Evaluation." VCU Scholars Compass, 2017. http://scholarscompass.vcu.edu/etd/4741.
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The objective of this study was to evaluate the biofilm removal efficacy of three root canal treatment systems: ProUltra® PiezoFlow™, traditional needle irrigation, and the GentleWave® system in an ex-vivo benchtop study. Twenty-four extracted maxillary and mandibular molars were selected. Teeth were all instrumented to a master apical file size #25 with 4% taper. Teeth were then randomly divided into four experimental groups and two control groups. The root canals were inoculated with a culture of Enterococcus faecalis and incubated for five weeks to form a biofilm. Each group was then treated with one of the different root canal treatment systems using 6% sodium hypochlorite (NaOCl) as per the respective manufacturer’s recommendation followed by a rinse with water. Following treatment, teeth were decoronated and roots were sectioned longitudinally. Three scanning electron microscope images were taken at the apical level per root half at 5000x magnification. Images were scored by four calibrated examiners blind to group membership using a four-point scoring system (<5% coverage, 5-33%, 34-66%, and >66%). Results were analyzed using mixed model ANOVA. All the experimental groups were significantly better than the positive control group in removing biofilm. Among the experimental groups, the GentleWave® 15/04 group was significantly better than the other groups. There was no significant difference between the GentleWave® and the ProUltra® PiezoFlow™. Traditional needle irrigation scored the worst in reducing E. faecalis biofilm. The GentleWave™ system was as effective at intracanal biofilm removal as the ProUltra® PiezoFlow™ and better than traditional needle irrigation using 6% NaOCl as an irrigant.
Books on the topic "Enterococcus faecalis; biofilm; pH"
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Bao, Yinyin. Role of mprF1 and mprF2 in the pathogenicity of Enterococcus faecalis. Freiburg: Universität, 2012.
Find full textBook chapters on the topic "Enterococcus faecalis; biofilm; pH"
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Kumar Oli, Ajay, Palaksha K. Javaregowda, Apoorva Jain, and Chandrakanth R. Kelmani. "Mechanism Involved in Biofilm Formation of Enterococcus faecalis." In Bacterial Biofilms [Working Title]. IntechOpen, 2022. http://dx.doi.org/10.5772/intechopen.103949.
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Enterococci are commensal bacteria in the gastrointestinal flora of animals and humans. These are an important global cause of nosocomial infections. A Biofilm formation constitutes an alternative lifestyle in which microorganisms adopt a multi-cellular behavior that facilitates and prolongs survival in diverse environmental niches. The species of enterococcus forms the biofilm on biotic and abiotic surfaces both in the environment and in the healthcare settings. The ability to form biofilms is among the prominent virulence properties of enterococcus. The present chapter highlights the mechanisms underlying in the biofilm formation by enterococcus species, which influences in causing development of the diseases.
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Bhonchal Bhardwaj, Sonia, and Seema Kumari. "Oral Bacteriophages." In Bacteriophages in Therapeutics. IntechOpen, 2021. http://dx.doi.org/10.5772/intechopen.100269.
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Bacteriophage or phage therapy involves using phages or their products as bio-agents for the treatment or prophylaxis of bacterial infections or diseases. Bacteriophages have the ability to regulate the oral microflora by lysing sensitive bacterial cells and releasing bacterial components with pro-inflammatory activity. Bacteriophages carry specific polysaccharide depolymerases that aid viral penetration and can disrupt the pathogenic process associated with biofilm and exopolysaccharide in the oral cavity. Oral diseases are mainly caused by biofilm forming microorganisms and phages are now being used for biocontrol of oral biofilms. Phages for Actinomyces species, Aggregatibacter actinomycetemcomitans, Enterococcus faecalis, Fusobacterium nucleatum, Lactobacillus species, Neisseria species, Streptococcus species, and Veillonella species have been isolated and characterized. Bacteriophages could be considered as potential therapeutic tools for the elimination of caries, periodontitis, and other diseases of the oral cavity.
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Raja, Kavita. "Enterococcal Infections: Recent Nomenclature and emerging trends." In Streptococcal Infections [Working Title]. IntechOpen, 2022. http://dx.doi.org/10.5772/intechopen.104792.
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Enterococci are an emerging infectious threat both in the community and in the hospital, being hardy survivors, acquiring antibiotic resistance rapidly. This chapter will describe the evolution of enterococci from being rarely encountered pathogens to being a formidable pathogen in the modern era of multiple devices, complicated surgery and immunosuppression. Enterococci have been moved from the genus streptococci to the genus enterococcus based on genomic characteristics that make them different from streptococci. Several genotyping methods have been evolved for tracking them as they are major hospital acquired pathogens. They cause myriad infections like infective endocarditis, wound infections, urinary tract infections and surgical site infections. They are capable of biofilm formation that causes persistence at the site of infection. E. faecalis and E. faecium are the most common isolates and they are acquiring Vancomycin resistance at a rapid rate. While reporting susceptibility to antibiotics, Clinical Laboratory Standards Institute (CLSI) standards have to be followed.
Conference papers on the topic "Enterococcus faecalis; biofilm; pH"
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Ke Sun, Jue Zhang, Jing Fang, Jing Wang, Jie Pan, and Weidong Zhu. "Cold plasma therapy for enterococcus faecalis biofilm infected tooth root canal in vitro." In 2012 IEEE 39th International Conference on Plasma Sciences (ICOPS). IEEE, 2012. http://dx.doi.org/10.1109/plasma.2012.6383868.
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Pereira, Ulisses A., Luiz C. A. Barbosa, Célia R. A. Maltha, Antônio Jacinto Demuner, and Andréa de L. Pimenta. "Synthesis of lactones and lactams analogues to rubrolides as inhibitors of Enterococcus faecalis biofilm formation." In 15th Brazilian Meeting on Organic Synthesis. São Paulo: Editora Edgard Blücher, 2013. http://dx.doi.org/10.5151/chempro-15bmos-bmos2013_2013814154045.
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Li, Yinglong, Guomin Wang, Jue Zhang, Jing Fang, Jie Pan, and Weidong Zhu. "Evaluation of cold plasma treatment and safety in disinfecting 21-day root canal enterococcus faecalis biofilm in vitro." In 2014 IEEE 41st International Conference on Plasma Sciences (ICOPS) held with 2014 IEEE International Conference on High-Power Particle Beams (BEAMS). IEEE, 2014. http://dx.doi.org/10.1109/plasma.2014.7012693.
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Hidayati, Rizka, Ari Asnani, Muhamad Salman Fareza, and Dwi Utami Anjarwati. "In Vitro Study of Reduction of Oral Enterococcus faecalis Biofilm on Application of Combination of Chrysomya megacephala Maggot Extract and Sodium Hypochlorite." In 1’s t Jenderal Soedirman International Medical Conference (JIMC) in conjunction with the Annual Scientific Meeting (Temilnas) Consortium of Biomedical Science Indonesia (KIBI ). SCITEPRESS - Science and Technology Publications, 2020. http://dx.doi.org/10.5220/0010488400980103.
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