Academic literature on the topic 'Enterococcus faecalis ATCC antibacterial activity'

Objetivo: Evaluar el límite de inhibición bacteriana del Hidróxido de Calcio en polvo sobre cepas de Enterococcus faecalis ATCC® 29212™. Materiales y Métodos: Este estudio experimental in vitro utilizó 40 placas petri con agar BHI solidificado. Se preparó la solución de Hidróxido de Calcio [Ca(OH)2] en polvo de la marca Biodinámica y Maquira a la concentración de 1g/ml. La Concentración Mínima Inhibitoria (CMI) y la Concentración Mínima Bacteriostática (CMB) fueron evaluadas mediante diferentes concentraciones de Ca(OH)2 (0.02 g/ml - 1g/ml). La CMI fue evaluada mediante la técnica de Kirby Bauer y la CMB mediante la técnica de Recuento de Unidades Formadoras de Colonia (UFC). Resultados: Al evaluar la actividad antibacteriana de Ca(OH)2 contra la cepa de E. faecalis, se observó las siguientes medias del halo de inhibición: Biodinámica 22.66 ± 0.38 mm; Maquira 23.58 ± 0.47 mm y Clorhexidina al 12% (control positivo) 23.93 ± 0.73 mm. La CMI del Ca(OH)2 en polvo de ambas marcas fue de 0.063 g/ml como límite inferior, confirmando la inhibición del crecimiento de la cepa de Enterococcus faecalis ATCC® 29212™, siendo el límite superior de 1g/ml. Por otro lado, el CMB del Ca(OH)2 en polvo muestra un valor de 0.031 g/ml para la marca Biodinámica y 0.063 g/ml. para la marca Maquira. Conclusión: El límite inferior y superior de inhibición bacteriana del Hidróxido de Calcio, sobre cepas de Enterococcus faecalis ATCC® 29212™ fue de 0.063 g/ml y de 1gr/ml, respectivamente.<br>Objective: To evaluate the bacterial inhibition limit of Calcium Hydroxide powder on strains of Enterococcus faecalis ATCC® 29212™. Materials and Methods: This in vitro experimental study used 40 petri dishes with solidified BHI agar. The solution of Calcium Hydroxide [Ca(OH)2] powder of the brand Biodinámica and Maquira was prepared at the concentration of 1 g / ml. The Minimum Inhibitory Concentration (MIC) and the Minimum Bacteriostatic Concentration (MBC) were evaluated using different concentrations of Ca(OH)2 (0.02 g /ml - 1 g/ml). The CMI was evaluated using the Kirby Bauer technique and the CMB using the Colonies Formation Units (CFU) technique. Results: The antibacterial activity of Ca(OH)2 against the E. faecalis strain, presented the following means of inhibition halo were observed: Biodinámica 22.66 ± 0.38 mm; Maquira 23.58 ± 0.47 mm and 12% Chlorhexidine (positive control) 23.93 ± 0.73 mm. The MIC of the Ca(OH)2 powder of both brands was 0.063 g / ml as the lower limit, confirming the inhibition of the growth of Enterococcus faecalis ATCC ® 29212 ™ strain with the upper limit of 1 g / ml. On the other hand, CMB of the Ca(OH)2 powder shows a value of 0.031 g / ml for Biodinámica and 0.063 g / ml. for Maquira. Conclusion: The lower and upper limit of bacterial inhibition of Calcium Hydroxide, on strains of Enterococcus faecalis ATCC ® 29212™ was 0.063 g / ml and 1 g / ml, respectively.<br>Tesis

Magister Scientiae Dentium - MSc(Dent)<br>Background: The primary goal of pulp therapy in the deciduous dentition is to keep the teeth fully functional in order to prevent arch space loss. A pulpectomy is a pulp therapy procedure indicated when an irreversibly inflamed or necrotic radicular pulp is encountered. ZOE and iodoform pastes (i.e. Kri 1 paste and Vitapex) have been recommended as root filling materials after pulpectomy. High clinical success rates have been reported with Vitapex and the fact that it resorbs readily when extruded beyond the apex is an added advantage. However, it has also been reported to resorb from within the root canals and even cause pathological root resorption in cases where the vital pulp is inflamed (Nurko et al., 2000). Iodoform-based preparations are thought to be more appropriate because they fulfill nearly all the requirements of the ideal root filling materials in primary teeth. Despite this, there are limited studies comparing the antibacterial effect of iodoform-based preparations. Aim: The aim of this study was to evaluate the antibacterial efficacy of Vitapex (V), Kri 1 paste (K) and pure iodoform (I) against E. faecalis.

M. Tech. (Department of Chemistry, Faculty of Applied and Computer Sciences), Vaal University of Technology<br>The present study includes the use of a green synthetic method to prepare copper and silver nanoparticles using chitosan, aqueous extracts of Camellia sinensis, Combretum molle and Melia azedarach linn leaves. This study aims to investigate the influence of capping and precursor concentration on the properties of silver nanoparticles with emphasis on the medicinal plants chosen. The effect of capping agent on the properties of copper nanoparticles is also investigated. The phytochemical properties of plant extracts and the antimicrobial activity of the synthesized particles were also studied; this was achieved by using microdilution bioassay. Decoction method was used to extract secondary metabolites from plant leaves. Preliminary phytochemical screening carried out on the aqueous extracts of the plant leaves showed the presence of tannins, proteins, flavonoids, phenols, and carbohydrates. The total phenolic and flavonoids content of the aqueous extract was determined using spectroscopic methods. The highest phenolic content was found in the aqueous extract of Combretum molle (135 mg/g), and the highest flavonoid content was found in the aqueous extract of Camellia sinensis (0.4 mg/g). Characterization was done by a combination of spectroscopic, microscopy and XRD techniques. Both the size and shape of the synthesized silver nanoparticles were dependent on the identity of the capping molecule, precursor and capping agent concentration as depicted from their TEM and XRD results. Silver nanoparticles were found to be predominantly spherical. The capping agent concentration was also found to influence the degree of agglomeration, with an increase in capping agent concentration giving lesser agglomeration. FTIR spectral analysis showed that silver nanoparticles interact with bioactive compounds found in the plants through the hydroxyl functional group. Other shapes including diamond were observed for the effect of precursor concentration. The XRD micrographs revealed a face-centered cubic geometry and the phase remained the same with an increase in precursor concentration. The synthesized silver nanoparticles were all blue shifted compared to the bulk material. The TEM results revealed that copper nanoparticles with different sizes and shapes were successfully synthesized. All the prepared copper and silver nanoparticles showed satisfactory antifungal and antibacterial activity against Candida albicans, Cryptococcus neoformans, Staphylococcus aureus, Enterococcus faecalis, Klebsiella pneumonia and Pseudomonas aeruginosa. The capping molecules used in this study also showed some antibacterial and antifungal activity against the selected strains. However nanoparticles performed better than these capping molecules. Both silver and copper nanoparticles were found to be more active against gram-negative bacteria compared to gram-positive bacteria. Amongst all the prepared silver nanoparticles Combretum molle capped nanoparticles were found to be the most active nanoparticles. Also with copper nanoparticles, it was found that Combretum molle capped nanoparticles were the most active nanoparticles. Between the two metal nanoparticles, silver nanoparticles showed high antibacterial and antifungal activity compared to copper nanoparticles. The antioxidant activity of silver nanoparticles was assessed using 2.2-diphenyl-1-picrylhydrazyl. Silver nanoparticles were found to have some antioxidant activity. However, the capping molecules were found to be more active than the synthesized nanoparticles. This observation is attributed to the presence of some bioactive compounds in the plant extracts.

Dissertação de Mestrado em Bioquímica apresentada à Faculdade de Ciências e Tecnologia<br>Bacterial infections are associated with high morbidity/mortality in humans and the combat to these infections relies on the use of antibiotics. However, the recurrent administration of antibiotics throughout time led to an adaptation from bacterial species and consequently the need of new medical alternatives. Natural extracts such as the tea of Cammelia sinensis or coffee and decaffeinated grounds have already proved to have antibacterial properties therefore the main goal of this work is to understand the antibacterial activity of these extracts against Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus and Enterococcus faecalis. The antimicrobial assays were created according to the M07-A10 from the Clinical Laboratory Standards Institute using the microdilution plate method in which each extract was tested in concentrations of 50%, 25%,12,5% and 6,25% (v/v) in order to determine its Minimum Inhibitory Concentration (MIC). The bacterial inocula which suffered inhibition of growth were cultured in Columbia agar to determine the reduction of the population achieved by the treatment with the extracts. The results shown in this work suggest all extracts have antibacterial properties against the species under analysis, especially the tea and spent coffee extracts. The tea proves bactericidal properties when used in high concentration (50%) in all species except E.coli (Percentage Reduction of 82%). When used at lower concentrations, the tea maintains bactericidal properties against S. aureus and proves to have bacteriostatic properties against the remaining species. The spent coffee extract has bactericidal properties S. aureus and bacteriostatic properties against E. faecalis, P. aeruginosa, and E. coli, causing Percentage Reductions of 65,6%, 74,5% and 59,2%, respectively. The spent decaffeinated extract showed to have the least extent antibacterial activity among all three, yet causing a PR of 100% of the S. aureus population when used in concentrations of 50% and 25%. When it comes to the remaining species, this extract can cause a PR of 52% of E. faecalis and 60% of E.coli, being less effective only against P. aeruginosa (32%). This said, among all three extracts used, the most relevant antibacterial properties are found in both extracts of C. sinensis and spent coffee grounds, being the most effective against S. aureus.<br>Infeções bacterianas estão associadas a elevada morbilidade/mortalidade em seres humanos e a sua principal forma de combate recai no uso de antibióticos. No entanto, a administração destes fármacos de forma recorrente, a longo prazo, levou à aquisição de resistências e, consequentemente, à necessidade de alternativas terapêuticas. Extratos naturais de chá de Cammelia sinensis, de café e de descafeinado já mostraram ter propriedades antibacterianas, por isso, o objetivo deste trabalho é estudar as suas propriedades antibacterianas contra Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus e Enterococcus faecalis. Os ensaios antimicrobianos foram feitos de acordo com a norma M07-A10 do Clinical Laboratory Standards Institute, usando o método de microdiluição em placa e cada extrato foi testado nas concentrações de 50%, 25%,12,5% e 6,25% (v/v), para determinar a sua Concentração Mínima Inibitória (CMI). Os inóculos bacterianos com inibição do crescimento foram cultivados em meio de gelose columbia para determinação da redução da população conseguida pelo tratamento com os extratos. Os resultados apresentados sugerem que todos os extratos possuem atividade antibacteriana contra as espécies testadas, especialmente os extratos de chá e borra de café. O chá mostra atividade bactericida quando usado na concentração de 50%, em todas as espécies exceto E.coli (redução na população de 82%). Quando usado em concentrações mais baixas, o chá mantém atividade bactericida contra S. aureus e apresenta atividade bacteriostática contra as restantes espécies. Paralelamente, o café possui efeito bactericida contra S. aureus, e atividade bacteriostática contra E. faecalis, P. aeruginosa e E. coli, causando reduções nas populações iniciais de 65,6%, 74,5% e 59,2%, respectivamente. O extrato de borra de descafeinado mostrou ter o menor potencial antibacteriano de entre os três, mesmo assim com efeito bactericida em S. aureus quando usado em concentrações de 50% e 25%. Para as restantes espécies, este extrato causa RP de 52% de E. faecalis e 60% de E.coli, sendo menos eficaz apenas para P. aeruginosa (32%). Em suma, dos três extratos utilizados, as propriedades antibacterianas mais intensas estão presentes nos extratos de C. sinensis e de borra de café. A espécie que se revelou mais suscetível à ação dos 3 extratos foi S. aureus.<br>Outro - This work was financed by the European Regional Development Fund (ERDF), through the Centro 2020 Regional Operational Programme under project CENTRO-01-0145-FEDER- 022095:ViraVector; and through Portuguese national funds via FCT – Fundação para a Ciência e a Tecnologia; through the COMPETE 2020 - Operational Programme for Competitiveness and Internationalisation and Portuguese national funds via FCT – Fundação para a Ciência e a Tecnologia, under project UIDB/04539/2020, and by the European Regional Development Fund (ERDF), through the Centro 2020 Regional Operational Programme: project CENTRO-01-0145-FEDER000012-HealthyAging2020; the COMPETE 2020 – Operational Programme for Competitiveness and Internationalisation, and the Portuguese national funds via FCT – Fundação para a Ciência e a Tecnologia, I.P.: project POCI-01-0145-FEDER-007440 and UIDB/04539/2020.