Actividad antimicrobiana de diferentes tipos de cementos endodónticos

El objetivo de este estudio fue evaluar la actividad antimicrobiana de los cementos endodónticos a base de resina (Epiphany, Sealer 26 e AH Plus), cementos a base de silicona (Roeko Seal) y cementos de óxido de zinc y eugenol (Intrafill), sobre cinco diferentes especies de microorganismos. El método utilizado fue el de difusión en Agar. Una capa base fue confeccionada usando Agar Müller-Hinton (MH) y los pozos fueron formados por la remoción del Agar. Los materiales fueron colocados en los pozos después de su manipulación. Los microorganismos usados fueron: Micrococcus luteus (ATCC 9341), Staphylococcus aureus (ATCC6538), Escherichia coli (ATCC10538), Pseudomonas aeruginosa (ATCC27853), Candida albicans (ATCC 1023) y Enterococcus faecalis (ATCC 10541). Las placas fueron mantenidas a temperatura ambiente por 2 horas para pre-difusión y posteriormente incubadas a 37(0) C por 24 horas. Los resultados demostraron que el cemento Epiphany y el Sealer 26 presentaron actividad antimicrobiana sobre todas las cepas evaluadas. El cemento AH Plus y el Intrafill mostraron una acción antimicrobiana sobre todos los microorganismos excepto P aeruginosa y el Roeko Seal no fue efectivo sobre ningún microorganismo.

The aim of this study was to evaluate the antimicrobial activity of root canal sealers based on resins (Epiphany, Sealer 26 and AH Plus), silicon (Roeko Seal) and zinc oxide and eugenol (Intrafill), against five different microorganism strains. The agar diffusion method was used. A base layer was made using Müller-Hinton agar (MH) and wells were formed by removing agar. The materials were placed into the wells immediately after manipulation. The microorganisms used were: Micrococcus luteus (ATCC9341), Staphylococcus aureus (ATCC6538), Escherichia coli (ATCC10538), Pseudomonas aeruginosa (ATCC27853), Candida albicans (ATCC 10231), and Enterococcus faecalis (ATCC 10541).The plates were kept at room temperature for 2 h for prediffusion and then incubated at 37(0) C for 24 h. The results showed that Epiphany and Sealer 26 presented antimicrobial activity against all strains. AH Plus and Intrafill presented antimicrobial activity against all strains except P aeruginosa and Roeko Seal wasn’t effective against any microorganism.

Bioactive chemical constituents and comparative antimicrobial activity of callus culture and adult plant extracts from Alternanthera tenella.

Crude extracts of a callus culture (two culture media) and adult plants (two collections) from Alternanthera tenella Colla (Amaranthaceae) were evaluated for their antibacterial and antifungal activity, in order to investigate the maintenance of antimicrobial activity of the extracts obtained from plants in vivo and in vitro. The antibacterial and antifungal activity was determined against thirty strains of microorganisms including Gram-positive and Gram-negative bacteria, yeasts and dermatophytes. Ethanolic and hexanic extracts of adult plants collected during the same period of the years 1997 and 2002 [Ribeirão Preto (SP), collections 1 and 2] and obtained from plant cell callus culture in two different hormonal media (AtT43 and AtT11) inhibited the growth of bacteria, yeasts and dermatophytes with inhibition halos between 6 and 20 mm. For the crude extracts of adult plants bioassay-guided fractionation, purification, and isolation were performed by chromatographic methods, and the structures of the isolated compounds were established by analysis of chemical and spectral evidences (UV, IR, NMR and ES-MS). Steroids, saponins and flavonoids (aglycones and C-glycosides) were isolated. The minimum inhibitory concentration (MIC) of the isolated compounds varied from 50 to 500 microg/mL.

Effect of three methods for cleaning dentures on biofilms formed in vitro on acrylic resin.

PURPOSE: The aim of this study was to evaluate the effect of three denture hygiene methods against different microbial biofilms formed on acrylic resin specimens. MATERIALS AND METHODS: The set (sterile stainless steel basket and specimens) was contaminated (37 degrees C for 48 hours) by a microbial inoculum with 10(6) colony-forming units (CFU)/ml (standard strains: Staphylococcus aureus, Streptococcus mutans, Escherichia coli, Candida albicans, Pseudomonas aeruginosa, and Enterococcus faecalis; field strains: S. mutans, C. albicans, C. glabrata, and C. tropicalis). After inoculation, specimens were cleansed by the following methods: (1) chemical: immersion in an alkaline peroxide solution (Bonyplus tablets) for 5 minutes; (2) mechanical: brushing with a dentifrice for removable prostheses (Dentu Creme) for 20 seconds; and (3) a combination of chemical and mechanical methods. Specimens were applied onto a Petri plate with appropriate culture medium for 10 minutes. Afterward, the specimens were removed and the plates incubated at 37 degrees C for 48 hours. RESULTS: Chemical, mechanical, and combination methods showed no significant difference in the reduction of CFU for S. aureus, S. mutans (ATCC and field strain), and P. aeruginosa. Mechanical and combination methods were similar and more effective than the chemical method for E. faecalis, C. albicans (ATCC and field strain), and C. glabrata. The combination method was better than the chemical method for E. coli and C. tropicalis, and the mechanical method showed intermediate results. CONCLUSION: The three denture hygiene methods showed different effects depending on the type of microbial biofilms formed on acrylic base resin specimens.

Antimicrobial activity of endodontic sealers based on calcium hydroxide and MTA.

The aim of this study was to evaluate the antimicrobial activity of a new root canal sealer containing calcium hydroxide (Acroseal) and the root canal sealer based on MTA (Endo CPM Sealer), in comparison with traditional sealers (Sealapex, Sealer 26 and Intrafill) and white MTA-Angelus, against five different microorganism strains. The materials and their components were evaluated after manipulation, employing the agar diffusion method. A base layer was made using Müller-Hinton agar (MH) and wells were made by removing agar. The materials were placed into the wells immediately after manipulation. The microorganisms used were: Micrococcus luteus (ATCC9341), Staphylococcus aureus (ATCC6538), Pseudomonas aeruginosa (ATCC27853), Candida albicans (ATCC 10231), and Enterococcus faecalis (ATCC 10541). The plates were kept at room temperature for 2 h for prediffusion and then incubated at 37 degrees C for 24 h. The results showed that Sealapex and its base paste, Sealer 26 and its powder, Endo CPM Sealer and its powder, white MTA and its powder all presented antimicrobial activity against all strains. Intrafill and its liquid presented antimicrobial activity against all strains except P. aeruginosa and Acroseal was effective only against M. luteus and S. aureus.

Atividade antimicrobiana in vitro do álcool gel a 70 (por cento) frente às bactérias hospitalares e da comunidade / In vitro antimicrobial activity of gel alcohol 70 against hospital and community bacteria

O uso de álcool gel em procedimentos de anti-sepsia das mãos representa uma prática freqüente nas instituições de saúde. Assim, estabeleceu-se: determinar in vitro a atividade antibacteriana do álcool gel a 70%, utilizado no Hospital das Clínicas da Faculdade de Medicina de Ribeirão Preto – USP, frente às bactérias hospitalares e da comunidade, por meio das técnicas de gotejamento e do poço. As bactérias hospitalares foram Staphylococcus aureus, Escherichia coli, Klebsiella spp., Pseudomonas aeruginosa, e da comunidade: S. aureus e Staphylococcus coagulase-negativo. O álcool gel apresentou atividade antibacteriana, pela técnica de gotejamento, frente a todas as bactérias estudadas, porém com a técnica do poço nenhum efeito foi observado. Em conclusão, antes de utilizar alguma substância ou produto contra microrganismos é necessário avaliar previamente a sua eficácia com técnicas ou métodos microbiológicos adequados.

The use of gel alcohol in hands antisepsis procedures represents a frequent practice in health institutions. Thus, we decided to determine the in vitro antibacterial activity of gel alcohol 70% used at Clinical Hospital of Faculty of Medicine of Ribeirão Preto – USP against hospital and community bacteria by means of dripping and well technique. Hospital bacteria were: Staphylococcus aureus, Escherichia coli, Klebsiella spp., Pseudomonas aeruginosa, while community bacteria were: S. aureus and Staphylococcus coagulase-negative. The gel alcohol demonstrated antimicrobial activity by means of the dripping technique against all bacteria studied, but with the well technique no effect was observed. In conclusion, before using any substance or product against microorganisms it is necessary to evaluate previously its effectiveness with adjusted microbiological techniques or methods.

Aminoglycoside antibiotic derivatives: preparation and evaluation of toxicity on cochlea and vestibular tissues and antimicrobial activity.

Aminoglycoside antibiotic derivatives such as neamine, methyl neobiosaminide B, 2-deoxystreptamine, tetra-azidoneamine, tetra-N-acetylneamine, tetra-N-carboxy-benzylneamine, tetra-N-carboxy-methylneamine and tetra-p-methoxy-benzyliminoneamine were prepared and evaluated as to their cochlear and vestibular toxicity. Methyl neobiosaminide B, the most promising derivative in the series showed selective, cochlea-dissociated vestibulotoxic activity and was considered to be a potential lead compound for the treatment of Ménière's disease. Antimicrobial properties of the compounds, qualitatively evaluated against a group of pathogenic bacteria, indicated that neomycin B sulfate, neamine as a free base and methyl-neobiosaminide B dihydrochloride show a broader range of activity when compared to the other derivatives.

In vitro antimicrobial activity of endodontic sealers, MTA-based cements and Portland cement.

The aim of this study was to evaluate the antimicrobial activity of different root-end filling materials - Sealer 26, Sealapex with zinc oxide, zinc oxide and eugenol, white and gray Portland cement, white and gray MTA-Angelus, and gray Pro Root MTA - against six different microorganism strains. The agar diffusion method was used. A base layer was made using Müller-Hinton agar (MH) and wells were formed by removing the agar. The materials were placed in the wells immediately after manipulation. The microorganisms used were: Micrococcus luteus (ATCC9341), Staphylococcus aureus (ATCC6538), Escherichia coli (ATCC10538), Pseudomonas aeruginosa (ATCC27853), Candida albicans (ATCC 10231), and Enterococcus faecalis (ATCC 10541). The plates were kept at room temperature for 2 h for prediffusion and then incubated at 37 degrees C for 24 h. Triphenyltetrazolium chloride 0.05% gel was added for optimization, and the zones of inhibition were measured. Data were subjected to the Kruskal-Wallis and Dunn tests at a 5% significance level. The results showed that all materials had antimicrobial activity against all the tested strains. Analysis of the efficacy of the materials against the microbial strains showed that Sealapex with zinc oxide, zinc oxide and eugenol and Sealer 26 created larger inhibition halos than the MTA-based and Portland cements (P < 0.05). On the basis of the methodology used, it may be concluded that all endodontic sealers, MTA-based and Portland cements evaluated in this study possess antimicrobial activity, particularly the endodontic sealers.

Evaluation of the antimicrobial activity of crude extracts and isolated constituents from Chresta scapigera

Crude extracts and eight isolated compounds from Chresta scapigera were evaluated for antibacterial and antifungal activities by the agar-well diffusion method. Twenty strains, including Gram-positive and Gram-negative bacteria and yeasts were used in the bioassay. Hexane extracts presented the best results while ethanol extracts did not indicate inhibition of the microbial growth. Amongst the evaluated compounds b-amyrin acetate, tiliroside and luteolin showed the strongest antimicrobial effect.

Os extratos brutos e oito constituintes isolados de Chresta scapigera foram avaliados para as atividades antibacteriana e antifúngica, utilizando o método de difusão em ágar. Vinte cepas indicadoras, incluindo bactérias (Gram-positivas e Gram-negativas) e leveduras, foram utilizadas no bioensaio. Os melhores resultados foram obtidos para os extratos hexânicos, enquanto os extratos etanólicos não inibiram o crescimento microbiano. Acetato de b-amirina, tilirosídeo e luteolina foram os mais eficazes dentre os constituintes avaliados.

Avaliação da atividade antimicrobiana e citotóxica de extratos de Gochnatia polymorpha ssp floccosa / Evaluation of antimicrobial and cytotoxic activitiy of extracts from Gochnatia polymorpha (Less) ssp floccosa

Neste estudo procedeu-se a avaliação da atividade antimicrobiana e citotóxica de extratos de Gochnatia polymorpha ssp floccosa, espécie empregada na medicina popular contra doenças respiratórias. Folhas, cascas do tronco e ramos foram extraídos com hexano, diclorometano e etanol, sucessivamente, sendo obtidos os respectivos extratos brutos. A atividade antimicrobiana foi determinada pelo método de difusão em ágar utilizando-se bactérias Gram-positivas, Gram-negativas e fungos. A avaliação da citotoxicidade foi realizada empregando-se o ensaio de letalidade contra Artemia salina. Nenhum dos extratos mostrou atividade citotóxica. Os extratos das folhas apresentaram uma fraca atividade antimicrobiana frente a algumas cepas de Staphylococcus aureus e Streptococcus mutans, enquanto o extrato em diclorometano dos ramos e o extrato em etanol das cascas foram ativos contra Micrococcus luteus, Staphylococcus aureus e S. epidermidis. A maior atividade antimicrobiana foi observada para o extrato em diclorometano das cascas, que inibiu o crescimento de Micrococcus luteus, Staphylococcus aureus, S. epidermidis, Streptococcus mutans, Enterococcus faecalis e Candida albicans. Esta atividade parece estar relacionada à presença de diterpenos no extrato. Nenhum dos extratos estudados (a 5,0 mg/mL) mostrou atividade frente a cepas de bactérias Gram-negativas. Esses resultados demonstram o potencial dessa planta como fonte de compostos antibacterianos e justificam, parcialmente, seu uso popular.

The antimicrobial and cytotoxic activities of Gochnatia polymorpha ssp floccosa, a medicinal plant used against respiratory diseases, were evaluated. Successive petroleum ether, dichloromethane and ethanol extracts of dried leaves, trunk bark and stems were used in the brine shrimp lethality bioassay and tested against 22 strains of microorganisms (Gram-positive and Gram-negative bacteria and fungi) by the well-diffusion agar method. None of the extracts showed cytotoxicity on the brine shrimp bioassay. The extracts of leaves showed a mild activity against some strains of Staphylococcus aureus and Streptococcus mutans. The ethanol extracts of trunk bark and dichloromethane extract of stems also showed activity against Micrococcus luteus, Staphylococcus aureus and S. epidermidis. The highest activity was found in the dichloromethane extract of trunk bark, which showed significant antibacterial and antifungal activities against Micrococcus luteus, Staphylococcus aureus, S. epidermidis, Streptococcus mutans, Enterococcus faecalis and Candida albicans. Diterpenes are present in this extract and could be responsible for the activity. All the screened extracts were shown to be inactive (at 5.0 mg/mL) against strains of Gram-negative bacteria tested. These results indicate the potential of G. polymorpha ssp floccosa as a source of antibacterial compounds and partly support the use of this plant in folk medicine.

Antibacterial screening of anthocyanic and proanthocyanic fractions from cranberry juice.

The effect of anthocyanin- and proanthocyanidin-rich fractions isolated from cranberry juice was studied for their antibacterial activity against nine bacterial strains. Activity was assessed by the agar diffusion assay. Staphylococcus aureus ATCC 6538 was the only strain to exhibit some susceptibility to four out of 10 anthocyanin-rich fractions tested. A variable susceptibility of S. aureus, Enterococcus faecalis ATCC 10541, and Micrococcus luteus ATCC 9341 to proanthocyanidin- rich fractions was also observed. Streptococcus mutans strains as well as Escherichia coli ATCC 10538 and Pseudomonas aeruginosa ATCC 27853 were not susceptible to any of the cranberry juice samples or fractions at the tested concentrations. There was no clear correlation between Gram-positive or Gram-negative bacterial susceptibility to cranberry juice. In this work, the role of cranberry juice anthocyanic and proanthocyanic fractions upon bacterial viability is discussed.

Comparative study of antibacterial and antifugal activity of callus culture and adult plants extracts from Alternanthera maritima (Amaranthaceae)

Neste estudo procedeu-se a avaliação da atividade antibacteriana e antifúngica dos extratos brutos de Alternanthera maritima (Amaranthaceae) planta in natura de duas coletas distintas e obtidos por cultura de células buscando-se averiguar a manutenção da atividade antimicrobiana dos extratos obtidos da planta in vivo e in vitro. A ação antibacteriana e antifúngica foi determinada pelo método de difusão em ágar (técnica do poço) utilizando-se trinta cepas de microrganismos indicadores (bactérias Gram-positivas e Gram-negativas, leveduras e dermatófitos). Todos os extratos obtidos com solventes orgânicos avaliados apresentaram-se bioativos com halos de inibição de 6 a 20 mm. Os extratos da planta in natura das duas coletas (Restinga de Marica (RJ), verão de 1995 e 1998) inibiram o desenvolvimento de diferentes microrganismos (bactérias, leveduras e dermatófitos). Os extratos obtidos da cultura de calos desenvolvidos em duas condições de cultivo diferentes, também se mantiveram bioativos. Assim, os resultados obtidos encorajam a realização de novos estudos com esta espécie vegetal para se determinar quais as substâncias presentes nos extratos e que contribuem para a atividade biológica, como também para entender seu mecanismo de ação e avaliar sua toxicidade, visando uma possível aplicação farmacêutica.

A new heptasubstituted (E)-aurone glucoside and other aromatic compounds of Gomphrena agrestis with biological activity.

A new aurone 1 and two known substances, aurantiamide acetate (2) and tiliroside (3), were isolated from the ethanolic extract of Gomphrena agrestis. The structural determination of 1 was based on spectroscopic and spectrometric data. The substance was defined as (E)-3'-O-beta-D-glucopyranosyl-4,5,6,4'-tetrahydroxy-7,2'-dimethoxyaurone. Biological activity of the ethanolic crude extract and isolated compounds against bacteria, fungi and Leishmania amazonensis amastigotes was evaluated. This appears to be the first report documenting aurone and aurantiamide compounds in the Amaranthaceae family. In the evaluation of biological activity the ethanolic extract of G. agrestis and compounds 1, 2, and 3 were shown to be active mainly against Staphylococcus aureus, Staphylococcus epidermidis and Pseudomonas aeruginosa.

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

The aim of this study was to evaluate the presence of bacterial biofilm on the external surface of the root apex in teeth with pulp necrosis, with and without radiographically visible periapical lesions, and in teeth with a vital pulp. Twenty-one teeth were extracted, eight with pulp necrosis and periapical lesions, eight with pulp necrosis without radiographically visible periapical lesions, and five with a vital pulp. The roots were sectioned, and the root apexes (+/- 3 mm) were processed for scanning electron microscope evaluation. The surface of the apical root was evaluated for the presence of microorganisms, root resorption, and biofilm. There were no microorganisms on the apical root surface of either teeth with pulp vitality or with pulp necrosis with no radiographically visible periapical lesions. Microorganisms were always present in teeth with pulp necrosis and radiographically visible periapical lesions. These included cocci, bacilli, and filaments and the presence of an apical biofilm. Apical biofilm is clinically important because microbial biofilms are inherently resistant to antimicrobial agents and cannot be removed by biomechanical preparation alone. This may cause failure of endodontic treatment as a consequence of persistent infection.