Antimicrobial activity of Er, Cr: YSGG and Ultrasonic on E. faecalisbiofilm in the mesial root canal systems of lower molars / Atividade antimicrobiana de Er, Cr: YSGG e Ultrassônico no biofilme de E. faecalis nos sistemas de canais radiculares mesiais de molares inferiores

The internal topography of the root canal is complex, especially for the permanent molar's mesial root. In response to such issues, improved irrigation techniques have been created, which use laser pulses to agitate fluids and improve microbial deposit removal. Objective: To assess the effectiveness of the Er,Cr:YSGG laser with a wavelength of 2,780 nm via photon-induced photoacoustic streaming (PIPS) protocol which agitated of 2% chlorohexidine (CHX) in removing mature Enterococcus faecalis (E. faecalis) biofilm in root canal systems of lower molars. Material and Methods: The mesial roots of lower first and second molars were separated and inoculated with E. faecalis bacterial suspension for 30 days. The roots were irrigated with CHX, some of them were agitated with a passive ultrasonic device (PUI), while the other roots were agitated by an Er,Cr:YSGG laser in PIPS at 60 µs/pulse, 5 Hz, (0.25, 0.5, 0.75, and 1) W. An atomic force microscope (AFM) was used as a new method to get the results in the isthmus area; the obtained results from each group were compared with each other. Results: Based on the AFM and SEM analyses, laser and ultrasonic activation groups showed higher antimicrobial efficacy than the conventional syringe irrigation group (P<0.05). Conclusion: Based on the investigation's findings, the activation of 2% CHX solution by Er,Cr:YSGG laser in PIPS and PUI offers better mature bacterial biofilm removal in the mesial root of lower human molars than the same irrigant with the SI technique (AU)

A topografia interna do canal radicular é complexa, especialmente para a raiz mesial do molar permanente. Em resposta a esses problemas, foram criadas técnicas aprimoradas de irrigação, que utilizam pulsos de laser para agitar fluidos e melhorar a remoção de depósitos microbianos. Objetivo: Avaliar a eficácia do laser Er,Cr:YSGG com comprimento de onda de 2.780 nm via protocolo de streaming fotoacústico induzido por fótons (PIPS) que agitou clorohexidina a 2% (CHX) na remoção de Enterococcus faecalis maduro (E. faecalis) biofilme em sistemas de canais radiculares de molares inferiores. Material e Métodos: As raízes mesiais de 28 primeiros e segundos molares inferiores foram separadas e inoculadas com suspensão bacteriana de E. faecalis por 30 dias. As raízes foram irrigadas com CHX, sendo algumas delas agitadas com aparelho ultrassônico passivo (PUI), enquanto as demais raízes foram agitadas com laser Er,Cr:YSGG em PIPS a 60 µs/pulso, 5 Hz (0,25, 0,5, 0,75 e 1) W. Um microscópio de força atômica (AFM) foi utilizado como um novo método para obter os resultados na área do istmo; os resultados obtidos de cada grupo foram comparados entre si. Resultados: Com base nas análises de AFM e SEM, os grupos de ativação por laser e ultrassom apresentaram maior eficácia antimicrobiana do que o grupo de irrigação com seringa convencional (P<0.05). Conclusão: Com base nos achados da investigação, a ativação da solução de CHX a 2% pelo laser Er,Cr:YSGG em PIPS a (60 µs/pulso, 5 Hz, 0,75 W) oferece melhor remoção de biofilme (AU)

Avaliação do efeito antimicrobiano em parafuso protético de implantes revestido com filme de carbono tipo diamante dopados com prata depositado por plasma / Evaluation of antimicrobial action in prosthetic screws of implants with diamond-like carbon films doped with plasma deposited silver

Apesar da confiabilidade, as falhas mecânicas e biológicas das reabilitações protéticas sobre implantes ainda são persistentes. A capacidade altamente adaptativa das bactérias e sua colonização na superfície dos implantes e componentes protéticos ainda hoje é um sério problema clínico, causando mucosite e peri-implantite. O objetivo do trabalho foi avaliar o efeito antimicrobiano do fino filmes de carbono tipo diamante (DLC) dopado com nanopartículas de prata, depositado nos parafusos protéticos. Os filmes de DLC e DLC-Ag foram depositados pelo processo conhecido como PECVD (Plasma Enhanced Chemical Vapour Deposition). A caracterização do material foi realizada em discos da liga Ti6Al4V pelas análises scratch test, espectroscopia de espalhamento Raman, perfilometria mecânica, goniometria e espectroscopia de energia dispersiva (EDS). A atividade antimicrobiana foi avaliada utilizando uma cepa padrão de Enterococcus faecalis (ATCC 29212). Para avaliar a efetividade dos filmes depositados, foram realizados ensaios nos discos e nos parafusos (isolados e no modelo implante/pilar). Foram utilizados implantes hexágono externo de plataforma regular 4,1 mm com os respectivos pilares. Para todas as análises, as amostras foram divididas em 3 grupos de acordo com o tipo de tratamento: Grupo controle (sem tratamento); Grupo DLC, amostras revestidas com filme de DLC, Grupo DLC-Ag, amostras revestidas com filme de DLC com prata. As amostras foram analisadas por MEV. Também foi avaliada a citotoxicidade dos filmes frente a células de fibroblastos (3T3) através do ensaio de MTT. A caracterização dos filmes por espectroscopia de espalhamento raman e EDS, apresentaram resultados característicos ao DLC e DLC-Ag, como uma distribuição homogênea de carbono, prata e silício. As análises de scratch test, perfilometria mecânica e goniometria, apresentaram filmes com características hidrofóbicas, sendo DLC-Ag o grupo de maior rugosidade e coeficiente de atrito. Os dados obtidos foram analisados estatisticamente com auxílio do programa GraphPad Prism versão 9.0 (GraphPad Software Inc., San Diego, CA, USA) e realizado os testes ANOVA e de Tukey para comparações entre os grupos (discos), e os testes Kruskal-Wallis e post-hoc de Dunn (parafusos). O nível de significância para todos os testes foi estabelecido em 5%. Os resultados demonstraram que a deposição do filme de DLC e DLC-Ag apresentaram redução de maneira significativa (p<0,05) na contagem de UFC/ml nos discos e parafusos isolados. Porém a dopagem com prata não trouxe um resultado superior ao filme DLC e ambos os materiais se apresentaram como não citotóxico. Concluímos que o revestimento com DLC e DLC-Ag é um material promissor, com efeito antimicrobiano, porém com limitação de aplicação (AU)

Despite the reliability, the mechanical and biological failures in rehabilitating implantsupported dental are still persistent. Mucositis and peri-implantitis are still severe clinical problems due to the high adaptive capacity of bacteria that colonize the surface of implants and prosthetic components. The present study aimed to evaluate, in vitro, the antimicrobial action of thin films of diamond-like carbon (DLC) doped with silver nanoparticles, deposited on prosthetic screws. The deposition of the films was performed by PECVD (Plasma Enhanced Chemical Vapor Deposition). The characterizations were performed of both deposited samples and control (Ti6Al4V) by scratch test analysis, raman scattering spectroscopy, mechanical profilometry, goniometry, and energy dispersive spectroscopy (EDS). The antimicrobial was evaluated activity against Enterococcus faecalis (ATCC 29212). To evaluate the effectiveness of the deposited films, tests were performed on disks and screws (isolated and on the implant/abutment model) Using 30 regular platforms with 4.1 mm external hexagon implants with the respective abutments, distributed into 3 groups according to the type of prosthetic screw treatment (n=10): Group control screw (no treatment); Group screw coated with DLC film, Group screw coated with DLC film doped with silver nanoparticles (Ag-DLC). The samples were also analyzed by SEM The cytotoxicity of the films against (3T3) fibroblast cells was also assessed using the MTT assay. The caracterization was performed from raman spectroscopy and EDS, showed results which are characteristics of DLC and Ag-DLC films, such as a homogeneous distribution of carbon, silver and silicon. The scratch test, mechanical profilometry and goniometry analyzes showed films with hydrophobic characteristics, with Ag-DLC being the group with the higher coefficient of friction values and roughness Data were statistically analyzed using GraphPad Prism version 9.0 (GraphPad Software Inc., San Diego, CA, USA). ANOVA and Tukey tests were performed, followed by comparisons between groups (disks) and Kruskal-Walis and post-hoc Dunn (screw) tests The significance level for all tests was set at 5%. The results demonstrated that the deposition of the DLC and Ag-DLC film showed a significant reduction (p<0.05) in the CFU/ml count compared to the contro, disks and isolated screwl. However, silver doping did not enhance the DLC films; both materials were non-cytotoxic. It concludes that titanium alloys coated with DLC and Ag-DLC are promising materials with antibacterial properties to prevent peri-implantitis (AU)

Antibacterial effect of low-temperature plasma on Enterococcus faecalis in dentinal tubules in vitro / 北京大学学报(医学版)

OBJECTIVE@#To construct a model of Enterococcus faecalis (E. faecalis) infection in dentinal tubules by gradient centrifugation and to evaluate the antibacterial effect of low-temperature plasma on E. faecalis in dentinal tubules.@*METHODS@#Standard dentin blocks of 4 mm×4 mm×2 mm size were prepared from single root canal isolated teeth without caries, placed in the E. faecalis bacterial solution, centrifuged in gradient and incubated for 24 h to establish the model of dentinal tubule infection with E. faecalis. The twenty dentin blocks of were divided into five groups, low-temperature plasma jet treatment for 0, 5 and 10 min, calcium hydroxide paste sealing for 7 d and 2% chlorhexidine gel sealing for 7 d. Scanning electron microscopy and confocal laser scanning microscope were used to assess the infection in the dentinal tubules and the antibacterial effect of low-temperature plasma.@*RESULTS@#The results of scanning electron microscopy and confocal laser scanning microscopy showed that after 24 h of incubation by gradient centrifugation, E. faecalis could fully enter the dentinal tubules to a depth of more than 600μm indicating that this method was time-saving and efficient and could successfully construct a model of E. faecalis infection in dentinal tubules. Low-temperature plasma could enter the dentinal tubules and play a role, the structure of E. faecalis was still intact after 5 min of low-temperature plasma treatment, with no obvious damage, and after 10 min of low-temperature plasma treatment, the surface morphology of E. faecalis was crumpled and deformed, the cell wall was seriously collapsed, and the normal physiological morphology was damaged indicating that the majority of E. faecalis was killed in the dentinal tubules. The antibacterial effect of low-temperature plasma treatment for 10 min exceeded that of the calcium hydroxide paste sealing for 7 d and the 2% chlorhexidine gel sealing for 7 d. These two chemicals had difficulty entering deep into the dentinal tubules, and therefore only had a few of antibacterial effect on the bacterial biofilm on the root canal wall, and there was also no significant damage to the E. faecalis bacterial structure.@*CONCLUSION@#Gradient centrifugation could establish the model of E. faecalis dentin infection successfully. Low-temperature plasma treatment for 10 min could kill E. faecalis in dentinal tubules effectively, which is superior to the calcium hydroxide paste sealing for 7 d and the 2% chlorhexidine gel sealing for 7 d.

Composición química y actividad antibacteriana del aceite esencial de Origanum vulgare L. frente a Enterococcus faecalis / Chemical composition and antibacterial activity of essential oil from Origanum vulgare L. against Enterococcus faecalis

Introducción: Las infecciones recurrentes en el sistema de conductos radiculares son atribuidas principalmente a la presencia de especies como Enterococcus faecalis, lo que hace necesario el estudio de sustancias alternativas al hipoclorito de sodio que puedan ser empleadas como irrigantes de los conductos y mejorar la tasa de éxito de tratamiento. Objetivo: Identificar la composición química del aceite esencial de Origanum vulgare L. (orégano) y evaluar su actividad antibacateriana frente a E. Faecalis ATCC 29212. Métodos: Se diseñó un estudio experimental in vitro. El Origanum vulgare L. se recolectó en la provincia de Tarata, Tacna, Perú. El aceite esencial se obtuvo por método de arrastre de vapor y una muestra fue sometida a cromatografía de gases acoplada a espectrometría de masas en un equipo cromatográfico QP2010 (Ultra Shimazu) equipado con una columna DB-5 MS para identificar sus constituyentes. La actividad antibacteriana del aceite esencial se evaluó a través del método de difusión de disco en agar cerebro-corazón con concentraciones desde 2,261 a 27,132 mg/µL. El cálculo de las repeticiones se realizó con el programa EPi infoTM. Adicionalmente, se identificó la concentración mínima inhibitoria y la concentración mínima bactericida del aceite esencial. Se realizó el análisis descriptivo de los datos y se aplicó la prueba ANOVA de un factor para comparar los valores medios de los halos de inhibición de las distintas concentraciones. Se adoptó un nivel de significancia de p < 0,05. Resultados: Se identificaron 20 constituyentes, siendo los principales compuestos alpha.-pinene (24,44 por ciento) y 1,6-Ocatien-3-ol,3,7,7dimethyl (12,52 por ciento). E. Faecalis fue muy sensible (++) y extremadamente sensible (+++) a concentraciones mayores a 15,827 mg/µL del aceite esencial de Origanum vulgare L. Todas las concentraciones inhibieron el crecimiento bacteriano, mientras que las concentraciones mayores de 14,018 mg/µL fueron bactericidas. Conclusiones: Los principales constituyentes del aceite esencial de Origanum vulgare L. fueron .alpha.-Pinene y Cis-.beta.-Terpineol. Además, se demostró un importante efecto antibacteriano frente a Enterococcus faecalis ATCC 29212(AU)

Introduction: Recurrent infections in the root canal system are mainly attributed to the presence of species such as Enterococcus faecalis. It is therefore necessary to study substances other than sodium hypochlorite which may be used as irrigants for the canals, thus improving the success rate of the treatment. Objective: Identify the chemical composition of essential oil from Origanum vulgare L. (oregano) and evaluate its antibacterial activity against E. faecalis ATCC 29212. Methods: An in vitro experimental study was conducted. Origanum vulgare L. was collected from the province of Tarata, Tacna, Peru. The essential oil was obtained by steam entrainment, and a sample was subjected to gas chromatography / mass spectrometry in a QP2010 chromatograph (Ultra Shimadzu) equipped with a DB-5 MS column to identify its constituents. Antibacterial activity of the essential oil was evaluated by the brain heart agar disk diffusion method at concentrations ranging from 2 261 to 27 132 mg/µl. The software EPi InfoTM was used to estimate the repetitions. Additionally, identification was performed of the minimum inhibitory concentration and the minimum bactericidal concentration of the essential oil. The data were subjected to descriptive analysis and one-factor ANOVA was performed to compare the mean values of inhibition haloes at the different concentrations. A significance level of p < 0.05 was established. Results: Twenty constituents were identified. The main compounds were .alpha.-pinene (24.44 percent) and 1,6-Ocatien-3-ol,3,7,7dimethyl (12.52 percent). E. Faecalis was very sensitive (++) and extremely sensitive (+++) to concentrations above 15 827 mg/µl of the essential oil of Origanum vulgare L. All the concentrations inhibited bacterial growth, and concentrations above 14 018 mg/µl were bactericidal. Conclusions: The main constituents of the essential oil of Origanum vulgare L. were .alpha.-pinene and cis-.beta.-terpineol. Additionally, the essential oil was shown to display considerable antibacterial activity against Enterococcus faecalis ATCC 29212(AU)

Efecto antimicrobiano in vitro de extractos de Caesalpinia Spinosa (algarrobo) sobre patógenos orales / In vitro antimicrobial effect of Caesalpinia Spinosa (carob tree) extracts on oral pathogens

La resistencia antimicrobiana es un problema de sa-lud pública mundial. Las infecciones por microorga-nismos resistentes pueden ser altamente transmisi-bles e incluso causar la muerte. Este hecho genera grandes costos para los pacientes y para los servi-cios de salud. El objetivo del presente trabajo fue de-terminar el efecto antimicrobiano in vitro de extractos etanólicos de Caesalpinia spinosa sobre el crecimien-to de Enterococcus faecalis, Staphylococcus aureus y Candida albicans. Se recolectaron y certificaron muestras de C. spinosa. Se obtuvieron extractos de hojas, vainas y semillas en concentraciones de 100%, 75%, 50% y 25%. Mediante Kirby - Bauer, se cargaron los discos con los extractos y se depositaron en el medio inoculado con cepas de E. faecalis, S. aureus y C. albicans; junto a un CP (antimicrobiano), y un CN (etanol). Las placas se incubaron a 370°C durante 24 horas, y posteriormente se midieron los halos de inhi-bición con un vernier digital. Destaca el valor del halo de extracto de vainas; superó al de Ampicilina 10mg, sobre el E. faecalis. El extracto de vainas presentó ma-yor diámetro de inhibición (19mm), el de semillas pre-sentó el más bajo (1mm). ANOVA arrojó diferencia es-tadísticamente significativa entre los datos obtenidos para todos los extractos. En conclusión, los extractos etanólicos de Caesalpinia spinosa tienen efecto anti-microbiano in vitro sobre Enterococcus faecalis, Sta-phylococcus aureus y Candida albicans. La actividad antimicrobiana del extracto es directamente propor-cional a su concentración. Los extractos de C. spinosa podrían ser utilizados como coadyuvantes en el trata-miento contra Enterococcus faecalis, Staphylococcus aureus, Candida albicans, que están relacionados con patologías orales (AU)

Antimicrobial resistance is a global public health problem. Infections with resistant microorganisms can be highly transmissible and even cause death. This fact generates great costs for patients and for health services. The objective of this work was to determine the in vitro antimicrobial effect of ethanolic extracts of Caesalpinia spinosa on the growth of Enterococcus faecalis, Staphylococcus aureus and Candida albicans. Samples of C. spinosa were collected and certified. Leaf, pod and seed extracts were obtained at concentrations of 100%, 75%, 50% and 25%. Using Kirby-Bauer, the disks were loaded with the extracts and deposited in the medium inoculated with strains of E. faecalis, S. aureus and C. albicans; together with a CP (antimicrobial), and a CN (ethanol). The plates were incubated at 370°C for 24 hours, then the inhibition halos were measured with a digital vernier. The value of the pod extract halo stands out, surpassing that of Ampicillin 10mg, over E. faecalis. The pod extract presented the greatest diameter of inhibition (19mm), the seed extract presented the lowest (1mm). ANOVA showed a statistically significant difference between the data obtained for all the extracts. In conclusion, the ethanolic extracts of Caesalpinia spinosa have an in vitro antimicrobial effect on Enterococcus faecalis, Staphylococcus aureus and Candida albicans. The antimicrobial activity of the extract is directly proportional to its concentration. C. spinosa extracts could be used as adjuvants in the treatment against Enterococcus faecalis, Staphylococcus aureus, Candida albicans, which are related to oral pathologies (AU)

Research progress in pathogenesis and control of Enterococcus faecalis with persistent infection in root canals / 中华口腔医学杂志

Root canal therapy is the common treatment for endodontic infections. Successful root canal therapy depends on favorable root canal preparation, root canal medication and three-dimensional obturation of the root canal system. The key to successful root canal therapy is to prevent re-infection of the highly complex root canal systems by removing infecious biofilms and bacterial toxins in the root canal system. The present paper reviews the pathogenic mechanism of the Enterococcus faecalis in the harsh environment of root canal system, the inflammation and immunity of refractory periapical periodontitis and the progress of infection control methods.

Efeito antimicrobiano e anti-inflamatório de ácidos fenólicos isolados, combinados e incorporados em hidrogéis de quitosana para aplicação endodôntica / Antimicrobial and anti-inflammatory effect of phenolic acids, alone, combined and incorporated in chitosan hydrogels for endodontic application

O objetivo do tratamento endodôntico é manter a integridade da raiz, bem como, prevenir ou resolver doenças periapicais, pela erradicação dos microrganismos e de suas fontes de nutrientes provenientes do sistema de canais radiculares. A complexidade da anatomia dos canais radiculares e dos biofilmes multiespécies aumenta a dificuldade em eliminar os microrganismos e controlar a inflamação por procedimentos químico-mecânicos convencionais, o que justifica o uso de medicações intracanais. Novos compostos com amplo efeito antimicrobiano e potencial antiinflamatório, como os ácidos fenólicos, poderiam ser explorados como princípios ativos de medicamentos intracanais. Entretanto, para aumentar a solubilidade, controlar a liberação e estender os efeitos biológicos dos ácidos fenólicos, seria interessante incorporá-los em carreadores de medicamentos como os hidrogéis de quitosana. Este estudo foi dividido em dois capítulos que apresentaram como objetivos: 1) avaliar as atividades antimicrobiana, antibiofilme e antiinflamatória e a citotoxicidade do ácido cinâmico e seus derivados; 2) sintetizar e caracterizar as propriedades químicas e físico-mecânicas de hidrogéis termossensíveis de quitosana e poloxamer contendo ácidos fenólicos, e avaliar o efeito desses hidrogéis sobre biofilmes multiespécies e na viabilidade de macrófagos e fibroblastos. No capítulo 1, a atividade antimicrobiana do ácido cinâmico (CI) e seus derivados ácido cumárico (CO), ácido cafeico (CA), ácido ferúlico (FE) e ácido sinápico (SI) foi avaliada pela determinação da concentração inibitória e bactericida mínima (CIM/CBM) e Concentração Inibitória Fracionada (CIF) sobre Enterococcus faecalis, Streptococcus mutans, Lactobacillus casei, Actinomyces israelii e Fusobacterium nucleatum. Os ácidos fenólicos foram selecionados e seu efeito em biofilmes dual-espécies e multiespécies com as mesmas cepas padrão ou cepas clínicas foram avaliados por contagem bacteriana, microscopia eletrônica de varredura e microscopia confocal. A viabilidade de fibroblastos L929 e macrófagos RAW 264.7 na presença desses ácidos fenólicos foi avaliada por ensaios de resazurina. Além disso, os níveis de mRNA dos marcadores pró-inflamatórios TNF-α, IL-1ß, iNOS e COX-2 foram determinados por PCR quantitativo TaqMan após exposição de macrófagos aos ácidos fenólicos e ao lipopolissacarídeo (LPS). No capítulo 2, foi realizada a síntese e caracterização físicomecânica de hidrogéis de quitosana-poloxamer (CPH) contendo ácidos fenólicos e avaliado seus efeitos no biofilme multiespécies e na viabilidade de macrófagos e fibroblastos. Os dados foram analisados estatisticamente considerando p< 0,05. O ácido cinâmico e o ácido cafeico apresentaram efeito inibitório e bactericida contra todas as espécies bacterianas testadas, com os menores valores de CIM e CBM. Entretanto, não houve efeito sinérgico entre eles (FICI> 0,5). Ambos os compostos (5x a CIM mais alta) foram eficazes na eliminação de biofilmes dual-espécies e na redução significativa de biofilmes multiespécies, especialmente o ácido cinâmico. O ácido cinâmico causou toxicidade mínima para ambas as culturas celulares nas concentrações de CIM e o ácido cafeico não foi citotóxico em concentrações abaixo de 0,125 mg/mL. Ambos os compostos reduziram significativamente TNF-α, IL-1ß, iNOS e COX-2, de maneira dose-dependente. Os CPH foram caracterizados como termorreversíveis e com propriedades mecânicas e bioadesivas desejáveis. O efeito dos hidrogéis CPH+CA (77,8%) e CPH+CI (73,2%) em reduzir os biofilmes multiespécies foi superior ao CPH+ hidroxido de cálcio (CH) (53,6%) e CPH+ clorexidina (CHX) (39,9%). Em geral, CPH + CI causou menor citotoxicidade quando comparado a CPH + CA, para ambas as linhagens celulares. Conclui-se que o ácido cinâmico e ácido cafeico apresentaram efeito bactericida e contra biofilmes formados por bactérias associadas com infecções endodônticas, causando baixa citotoxicidade. Ambos os compostos apresentaram efeito antiinflamatório, inibindo a expressão de marcadores próinflamatórios em macrófagos estimulados por LPS. Os hidrogéis de quitosana-poloxamer foram termorreversíveis e apresentaram adequadas propriedades mecânicas e adesivas para aplicação clínica, e quando combinados principalmente com ácido cinâmico, promoveram a redução de biofilmes multiespécies formados nos túbulos dentinários, causando baixa toxicidade em fibroblastos e macrófagos(AU)

The objective of endodontic treatment is to maintain the integrity of the root, as well as to prevent or resolve periapical diseases, by eradicating microorganisms and their sources of nutrients from the root canal system. The complexity of root canal anatomy and multispecies biofilms increases the difficulty in eliminating microorganisms and controlling inflammation by conventional chemical-mechanical procedures, which justifies the use of intracanal medications. New compounds with broad antimicrobial effect and anti-inflammatory potential, such as phenolic acids, could be explored as active principles of intracanal medications. However, to increase the solubility, control the release and extend the biological effects of phenolic acids, it would be interesting to incorporate them into drug carriers such as chitosan hydrogels. This study was divided into two chapters with the following objectives: 1) to evaluate the antimicrobial, antibiofilm and anti-inflammatory activities and the cytotoxicity of cinnamic acid and its derivatives; 2) synthesize and characterize chemical and physicomecanical properties of thermosensitive chitosan and poloxamer hydrogels containing phenolic acids and evaluate the effect of these hydrogels on multispecies biofilms and on the viability of macrophages and fibroblasts. In chapter 1, the antimicrobial activity of cinnamic acid (CI) and its derivatives coumaric acid (CO), caffeic acid (CA), ferulic acid (FE) and sinapic acid (SI) was evaluated by determining the minimum inhibitory and bactericidal concentration (MIC/MBC) and Fractional Inhibitory Concentration (FIC) on Enterococcus faecalis, Streptococcus mutans, Lactobacillus casei, Actinomyces israelii and Fusobacterium nucleatum. Phenolic acids were selected and their effect on bispecies and multispecies biofilms with the same standard or clinical strains were evaluated by bacterial counts, scanning electron microscopy and confocal microscopy. The viability of L929 fibroblasts and RAW 264.7 macrophages in the presence of these phenolic acids was evaluated by resazurin assays. In addition, mRNA levels of the proinflammatory markers TNF-α, IL-1ß, iNOS and COX-2 were determined by quantitative TaqMan PCR after macrophage exposure to phenolic acids and lipopolysaccharide (LPS). In chapter 2, the synthesis and physical-mechanical characterization of chitosanpoloxamer (CPH) hydrogels containing phenolic acids were performed and their effects on multispecies biofilm and on the viability of macrophages and fibroblasts were evaluated. Data were statistically analyzed considering p< 0.05. Cinnamic acid and caffeic acid showed an inhibitory and bactericidal effect against all bacterial species tested, with the lowest MIC and MBC values. However, no synergistic effect was observed between the compounds (FICI> 0.5). Both compounds (at 5x the highest MIC) were effective in eliminating dual-species biofilms and significantly decreasing multispecies biofilms, especially cinnamic acid. Cinnamic acid caused minimal toxicity to both cell cultures at MIC concentrations and caffeic acid was not cytotoxic at concentrations below 0.125 mg/mL. Both compounds significantly reduced TNF-α, IL1ß, iNOS and COX-2, in a dose-dependent manner. CPH were characterized as thermoreversible and with adequate mechanical and bioadhesive properties. The effect of CPH+CA (77.8%) and CPH+CI (73.2%) hydrogels against multispecies biofilms was superior to CPH + calcium hydroxide (CH) (53.6%) and CPH + chlorhexidine (CHX) (39.9%). In general, CPH + CI caused less cytotoxicity when compared to CPH + CA, for both cell lines. In conclusion, cinnamic acid and caffeic acid showed bactericidal effect and against biofilms of bacteria associated with endodontic infections, causing minimal cytotoxicity. In addition, both compounds showed an anti-inflammatory effect, inhibiting the expression of pro-inflammatory markers in LPS-stimulated macrophages. The chitosan-poloxamer hydrogels were thermoreversible and presented adequate mechanical and bioadhesive properties for clinical application, and when combined specially with cinnamic acid, they promoted the reduction of multispecies biofilms formed in the dentinal tubules, causing low toxicity to fibroblasts and macrophages(AU)

Actividad antimicrobiana de fracciones obtenidas del aceite esencial de Minthostachys mollis frente a patógenos orales / Antimicrobial activity of fractions obtained from essential oil of Minthostachys mollis against oral pathogens

Introducción: El aceite esencial de Minthostachys mollis ha demostrado poseer importantes propiedades antimicrobianas. Objetivo: Caracterizar químicamente las fracciones obtenidas del aceite esencial de Minthostachys mollis y evaluar la actividad antimicrobiana sobre Streptococcus mutans, Lactobacillus acidophilus, Enterococcus faecalis, Porphyromonas gingivalis y Candida albicans. Material y Métodos: Las fracciones de éter de petróleo, diclorometano y metanol del AE de M. mollis fueron caracterizadas químicamente por cromatografía de gases acoplada a espectrometría de masas. Las repeticiones del ensayo antimicrobiano se calcularon con el programa EPIDAT v.4.2. La actividad antimicrobiana se realizó por el método de difusión de disco y se calculó la concentración mínima inhibitoria por el método de microdilución. Los datos fueron analizados empleando la prueba ANOVA (p=0,05). Resultados: Los principales constituyentes de las fracciones de éter de petróleo, diclorometano y metanol fueron cis-Menthone (39,8 por ciento, thymol (31,2 por ciento) y α-Terpineol (43,6 por ciento), respectivamente. Todas las cepas fueron sensibles a las tres fracciones, aunque C. albicans fue la cepa más sensible, registrando halos de inhibición de 14,73±0,57 mm para la fracción de metanol, 20,91±0,55 mm para éter de petróleo y 20,38±0,58 mm para diclorometano, se encontraron diferencias significativas cuando se compararon frente a Clorhexidina al 0,12 por ciento y Nistatina (p<0,05). Las concentraciones mínimas inhibitorias de las fracciones variaron de 0,2 a 3,2 µg/mL. Conclusiones: Los principales constituyentes de las fracciones de éter de petróleo, diclorometano y metanol fueron cis-Menthone, thymol y α-Terpineol. Las fracciones de éter de petróleo y diclorometano fueron altamente efectivas para inhibir el crecimiento de S. mutans, L. acidophilus, E. faecalis, P. gingivalis y C. albicans(AU)

Introduction: The essential oil of Minthostachys mollis has demonstrated to have important antimicrobial properties. Objective: To chemically characterize the fractions obtained from the essential oil of Minthostachys mollis and to evaluate the antimicrobial activity against Streptococcus mutans, Lactobacillus acidophilus, Enterococcus faecalis, Porphyromonas gingivalis and Candida albicans. Material and Methods: The petroleum ether, dichloromethane and methanol fractions of the AE of M. mollis were chemically characterized by gas chromatography coupled to mass spectrometry. The repetitions of the antimicrobial test were calculated using the EPIDAT v.4.2 program. The antimicrobial activity was performed by the disk diffusion method and the minimum inhibitory concentration was calculated by the microdilution method. The data were analyzed using the ANOVA test (p=0.05). Results: The main constituents of the petroleum ether, dichloromethane and methanol fractions were cis-Menthone (39,8 percent), thymol (31,2 percent)) and α-Terpineol (43,6 percent)), respectively. All strains were sensitive to the three fractions, although C. albicans was the most sensitive strain, registering inhibition halos of 14,73±0.57 mm for the methanol fraction, 20,91±0.55 mm for petroleum ether and 20.38±0.58 mm for dichloromethane, finding significant differences when compared to 0,12 percent) Chlorhexidine and Nystatin (p<0,05). The minimum inhibitory concentrations of the fractions ranged from 0,2 to 3,2 µg/mL. Conclusions: The main constituents of the petroleum ether, dichloromethane and methanol fractions were cis-Menthone, thymol and α-Terpineol. The petroleum ether and dichloromethane fractions were highly effective in inhibiting the growth of S. mutans, L. acidophilus, E. faecalis, P. gingivalis, and Calbicans(AU)

Profile of host cell responses to exposure to stressed bacteria in planktonic; dislodged, and intact biofilm mode

Abstract The host defense response to microbial challenge emerging from the root canal system leads to apical periodontitis. The aim of this study was to evaluate the expression of inflammatory cytokines and Nitric Oxide (NO) by macrophages after interaction with Enterococcus faecalis in the: plankton and dislodged biofilm mode; intact biofilm mode stimulated by calcium hydroxide (CH), CH and chlorhexidine (CHX) or Triple Antibiotic Paste (TAP). For this purpose, culture of macrophages from monocytes in human peripheral blood (N=8) were exposed to the different modes of bacteria for 24 hours. Subsequently, the cytokines, such as, Tumor Necrotic Factor- alfa (TNF-α), interleukin (IL)-1β, IL-6, IL-10; and NO were quantified by Luminex xMAP and Greiss reaction, respectively. In addition to the potential therapeutic effects of the intracanal medication, their antimicrobial activity against Enterococcus faecalis biofilm were also tested in vitro by confocal microscopy. The experiments` data were analyzed by the Kruskal-Wallis test with the Dunn post hoc test (α < 0.05). Bacteria in dislodged biofilm mode were shown to be more aggressive to the immune system than bacteria in plankton mode and negative control, inducing greater expression of NO and TNF-α. Relative to bacteria in intact biofilm mode, the weakest antimicrobial activity occurred in Group CH. In Groups CH/CHX and TAP the percentage of dead bacteria was significantly increased to the same extent. Interestingly, the biofilm itself did not induce the release of pro-inflammatory cytokines - except for NO - while the biofilm treated with TAP and CH based pastes enhanced the levels of IL-6 and TNF-α; and IL-1 β, respectively. In contrast, the levels of a potent anti-inflammatory (IL-10) were increased in Group TAP.

Resumo A resposta de defesa do hospedeiro ao desafio microbiano que emerge do sistema de canais radiculares leva à periodontite apical. Os objetivos deste estudo foram avaliar a expressão de citocinas pró e anti-inflamatórias e Óxido Nítrico (NO) por macrófagos após interação com Enterococcus faecalis no modo: planctônio e de biofilme desalojado; biofilme intacto estimulado por hidróxido de cálcio (CH), CH e clorexidina ou Pasta Tri Antibiótica (TAP). Para isto, a cultura de macrófagos originados de monócitos do sangue periférico de humanos (N=8) foi exposta aos diferentes tipos de bactéria por 24 horas. Então, a quantificação da produção de of Fator de Necrose Tumoral- alfa (TNF-α), interleucina (IL)-1β, IL-6, IL-10 e NO por macrófagos se deu por meio do Luminex xMAP e reação de Greiss, respectivamente. Além dos potenciais efeitos terapêuticos desses compostos, sua atividade antimicrobiana contra E. faecalis também foi testada através microscopia confocal. Os dados dos experimentos foram analisados através do teste de Kruskal-Wallis com Dunn`s post hoc (α < 0.05). Bactéria em modo de biofilme desalojado se mostrou mais agressivo ao sistema imune que as bactérias planctônicas e controle negativo induzindo a maior excreção de NO e TNF-α. Em relação ao biofilme intacto, a atividade antimicrobiana mais fraca ocorreu no grupo de CH. Os grupos CHX e TAP aumentaram significativamente a porcentagem de bactérias mortas na mesma extensão. Interessantemente, o biofilme por ele mesmo não induziu a liberação de citocinas pro-inflamatórias - exceto por NO - enquanto que o biofilme tratado com TAP ou pastas a base de CH aumentaram os níveis de IL-6; e TNF-α e IL-1 β respectivamente. Em contraste, os níveis da potente citocina anti-inflamatória (IL-10) foram aumentados pelo grupo TAP.

Efficiency of a digital electrofulguration system in contaminated root canals in vitro

Abstract Decontamination of the root canal (RC) system is essential for successful endodontic therapy. In this in vitro study, it was evaluated the disinfection potential of an electrofulguration device, the Endox® Endodontic System (EES), in RC infected with Enterococcus faecalis. Sixty-five human lower premolars were instrumented with MTwo® system. The specimens were distributed into six experimental groups (n = 10), according to the irrigation protocol: 2% chlorhexidine gel (CHX); CHX + EES; 5.25% sodium hypochlorite (NaOCl); NaOCl + EES; saline solution (SS); and SS + EES. Five specimens were untreated (control). RC samples were collected before (C1) and after EES treatment (C2), after chemo-mechanical preparation (CMP) (C3), and after final EES treatment (C4). All samples were plated for colony forming units (CFU/mL) onto solid media. The data were analyzed by Wilcoxon and Friedman tests for intragroup comparisons and by Kruskal Wallis test followed by Dunn's test for intergroup comparisons (α = 0.05). Treatment with the EES did not significantly reduce the number of CFU/mL as compared to baseline levels (C1 vs. C2, p> 0.05). After CMP (C3), all groups showed a significantly reduced amount of CFU/mL (p <0.05), with no difference between CHX- and NaOCl-treated samples (p >0.05). Lastly, treatment with the EES following CMP (C4) did not significantly reduce the amount of CFU/mL (C3 vs. C4, p> 0.05). To conclude, the use of the Endox® Endodontic System did not result in considerable bacterial reduction at all operative times, while treatment with NaOCl and CHX was equally efficient for this purpose.

Resumo A descontaminação do sistema do canal radicular (CR) é essencial para o sucesso da terapia endodôntica. Neste estudo in vitro, foi avaliado o potencial de desinfecção de um dispositivo de eletrofulguração, o Endox® Endodontic System (EES), em CR infectado com Enterococcus faecalis. Sessenta e cinco pré-molares inferiores humanos foram instrumentados com o sistema MTwo®. As amostras foram distribuídas em seis grupos experimentais (n = 10), de acordo com o protocolo de irrigação: clorexidina gel a 2% (CHX); CHX + EES; Hipoclorito de sódio 5,25% (NaOCl); NaOCl + EES; solução salina (SS); e SS + EES. Cinco amostras não foram tratadas (controle). As amostras de CR foram coletadas antes (C1) e após o tratamento com EES (C2), após preparo químico-mecânico (PQM) (C3) e após o tratamento final com EES (C4). Todas as amostras foram plaqueadas para unidades formadoras de colônias (CFU / mL) em meio sólido. Os dados foram analisados pelos testes de Wilcoxon e Friedman para comparações intragrupos e pelo teste de Kruskal Wallis, seguidos pelo teste de Dunn para comparações intergrupos (α = 0,05). O tratamento com o EES não reduziu significativamente o número de CFU / mL em comparação com os níveis basais (C1 vs. C2, p> 0,05). Após PQM (C3), todos os grupos apresentaram uma quantidade significativamente reduzida de CFU / mL (p <0,05), sem diferença entre as amostras tratadas com CHX e NaOCl (p> 0,05). Por fim, o tratamento com o EES após PQM (C4) não reduziu significativamente a quantidade de CFU / mL (C3 vs. C4, p> 0,05). Concluindo, o uso do Endox® Endodontic System não resultou em redução bacteriana considerável em todos os momentos operatórios, enquanto os tratamentos com NaOCl e CHX foram igualmente eficientes para esse fim.

Cinamaldeído e terpineol como inibidores de biofilmes de Candida albicans e Enterococcus faecalis / Cinamaldehído y terpineol como inhibidores de biopelículas de Candida albicans y Enterococcus faecalis / Cinnamaldehyde and terpineol as inhibitors of Candida albicans and Enterococcus faecalis biofilms

Introdução: Os fitoconstituintes são moléculas naturais que apresentam atividade antimicrobiana satisfatória e devem ser estudados quanto ao seu uso como novas substâncias para irrigação dos canais radiculares. Objetivo: Avaliar o efeito inibitório dos fitoconstituintes cinamaldeído e α-terpineol frente a biofilmes monoespécie e duoespécie de microrganismos envolvidos na infecção endodôntica. Métodos: Trata-se de um estudo experimental na área de microbiologia aplicada, in vitro, cego quanto às análises e randomizado. Foram selecionados os fitoconstituintes cinamaldeído e α-terpineol. A atividade antimicrobiana frente Candida albicans e Enterococcus faecalis foi avaliada por meio da análise da capacidade metabólica com o uso da resazurina e análise da viabilidade celular pelo plaqueamento. O meio de cultura e a clorexidina 1 porcento serviram de controle negativo e positivo, respectivamente. Resultados: Observou-se ausência de crescimento para exposição dos biofilmes nas concentrações de 10 e 5 mg/mL de ambos os fitoconstituintes. Na concentração de 2,5 mg/mL de terpineol, constatou-se crescimento somente nos biofilmes monoespécie de C. albicans e duoespécie. Já na concentração de 1mg/mL de terpineol e cinamaldeído, verificou-se crescimento para todos os biofilmes. Conclusão: O cinamaldeído e α-terpineol apresentaram atividade inibitória frente biofilmes monoespécie e duoespécie de Candida albicans e Enterococcus faecalis, nas concentrações de 10 e 5 mg/mL(AU)

Introducción: Los fitoconstituyentes son moléculas naturales que presentan actividad antimicrobiana satisfactoria y deben ser estudiados en cuanto a su uso como nuevas sustancias para irrigación de los canales radiculares. Objetivo: Evaluar el efecto inhibitorio de fitoconstituyentes cinamaldehído y α-terpineol frente a biopelículas monoespecies y duoespecies de microorganismos involucrados en la infección endodóntica. Métodos: Estudio experimental en el campo de la microbiología aplicada, in vitro, ciego al análisis y aleatorizado. Se seleccionaron los fitoconstituyentes cinamaldehído y α-terpineol. La actividad antimicrobiana frente Candida albicans y Enterococcus faecalis fue evaluada por medio del análisis de la capacidad metabólica con el uso de la resazurina y análisis de la viabilidad celular por el plaqueamiento. El medio de cultivo y la clorexidina 1 por ciento sirvieron de control negativo y positivo, respectivamente. Resultados: Se observó ausencia de crecimiento para exposición de las biopelículas en las concentraciones de 10 y 5 mg/mL de ambos fitoconstituyentes. En la concentración de 2,5 mg/mL de terpineol se constató crecimiento solo en los biofilmios monoespecies de C. albicans y duoespecies. En la concentración de 1 mg/mL de terpineol y cinamaldehído se verificó crecimiento para todas las biopelículas. Conclusiones: Cinamaldehído y α-terpineol presentaron actividad inhibitoria frente a biofilmes monoespecies y duoespecies de Candida albicans y Enterococcus faecalis, en las concentraciones de 10 y 5 mg/mL(AU)

Introduction: Phytoconstituents are natural molecules displaying satisfactory antimicrobial activity. Studies should be conducted about their use as new root canal irrigants. Objective: Evaluate the inhibitory effect of the phytoconstituents cinnamaldehyde and α-terpineol against mono- and duo-species biofilms of microorganisms involved in endodontic infection. Methods: An experimental applied microbiology blind randomized in vitro study was conducted. The phytoconstituents selected were cinnamaldehyde and α-terpineol. Antimicrobial activity against Candida albicans and Enterococcus faecalis was evaluated by metabolic capacity analysis with resazurin and cell viability analysis by the plaque. The culture medium and 1 percent chlorhexidine served as negative and positive controls, respectively. Results: An absence of growth was observed for exposure of the biofilms at concentrations of 10 and 5 mg/ml of both phytoconstituents. At a concentration of 2.5 mg/ml terpineol displayed growth only in the mono-species biofilms of C. albicans and duo-species biofilms. At a concentration of 1 mg/ml terpineol and cinnamaldehyde displayed growth in all biofilms. Conclusions: Cinnamaldehyde and α-terpineol displayed inhibitory activity against mono- and duo-species biofilms of Candida albicans and Enterococcus faecalis at concentrations of 10 and 5 mg/ml(AU)

Presencia de infección de sitio quirúrgico en procedimientos gineco-obstétricos en un hospital de II nivel de atención, Honduras 2017-2018 / Presence of surgical site infection in obstetric-gynecological procedures in a level II care hospital, Honduras 2017-2018

OBJETIVO: Identificar la presencia de infección de sitio quirúrgico y factores de riesgo en pacientes sometidas a cirugías Gineco-Obstétricas de forma programada o de urgencia en un hospital de II nivel de atención en Honduras. METODOLOGÍA: Estudio observacional, descriptivo, retrospectivo; recopilando 226 fichas del registro de infección de sitio quirúrgico recuperadas de los expedientes clínicos brindados por el servicio de estadística del Hospital Mario Catarino Rivas. Captando pacientes sometidas a cirugías Gineco-Obstétricas, durante el 2017 y 2018. RESULTADOS: 99 fichas cumplieron los criterios de inclusión, reportando una edad de 24 años [RIQ, 19,0 - 30,0], peso 82,0 kg [RIQ, 51,7 - 98,25], talla 154 cm [150,0 - 158,0] y el IMC de 25,8 ± 3,6 kg/m2. Un 9,1% presento antecedentes de inmunosupresión. 5,1% presento ISQ. El 55.6% de las cirugías se realizó el mismo día de ingreso del paciente. El tiempo entre la profilaxis antibiótica y el comienzo de la intervención quirúrgica es de 60 minutos [RIQ, 40,0 - 160,0]. La duración de los procedimientos quirúrgicos son de 45 minutos [RIQ, 35,0 - 55,0]. Los microrganismos aislados en los cultivos fueron Cocos gram positivos (2/5), Enterococcus faecalis (1/5), Klebsiella pneumoniae (2/5). CONCLUSIÓN: La presencia de ISQ en cirugías Gineco-Obstétricas del HMCR es del 5.1%, identificando los siguientes factores de riesgo: edad extrema, obesidad, diabetes mellitus, estado inmunitario (VIH), profilaxis antibiótica (temprana); por último, la técnica y el tiempo quirúrgico.

OBJECTIVE: To identify the presence of surgical site infection and risk factors in patients undergoing Gynecological-Obstetric surgeries on a scheduled or emergency basis in a 2nd level of care hospital in Honduras. METHODOLOGY: Observational, descriptive, retrospective study, compiling 226 data sheets of the surgical site infection record recovered from the clinical records provided by the statistics service of the "Hospital Mario Catarino Rivas". Recruiting patients undergoing Gynecological-Obstetric surgeries, during 2017 and 2018. RESULTS: 99 tabs met the inclusion criteria, reporting an age of 24 [RIQ, 19.0 - 30.0], weight 82.0 kg [RIQ, 51.7 - 98.25], size 154 cm [150.0 - 158.0] and BMI of 25.8 ± 3.6 kg/m2. 9.1% have a history of immunosuppression. 5.1% present ISQ. 55.6% of surgeries were performed on the same day as the patient's admission. The time between antibiotic prophylaxis and the onset of surgery 60 minutes [RIQ, 40.0 - 160.0]. Duration of surgical procedures 45 minutes [RIQ, 35.0 - 55.0]. Isolated micro-morphisms in crops were Cocos gram positives (2/5), Enterococcus faecalis (1/5), Klebsiella pneumoniae (2/5). CONCLUSION: The presence of ISQ in HMCR Gynecological-Obstetric surgeries is 5.1%, identifying the following risk factors: extreme age, obesity, diabetes mellitus, immune status (HIV), early antibiotic prophylaxis; finally, technique and surgical time.

Evaluación de la susceptibilidad de Enterococcus faecalis ATCC-29212 frente a medica- mentos combinados con hidróxido de calcio / Evaluation of the susceptibility of Enterococcus faecalis ATCC-29212 to drugs combined with calcium hydroxide

La elevada incidencia del Enterococcus faecalis en procedimientos odontológicos es un tópico de interés para el área de la salud, esta bacteria resiste a varios antimicrobianos y su proliferación aumenta debido a su baja susceptibilidad a sustancias de uso convencional como el hidróxido de calcio, convirtiéndose en una de las principales causas del fracaso de los tratamientos de conduc- to. La presente investigación evaluó la susceptibilidad in vitro del Enterococcus faecalis cepa ATCC-29212 frente a la combinación de sustancias y antibióticos con el hidróxido de calcio. Se utilizó la técnica de difusión en agar, inoculando el microorganismo en cajas de Petri con agar Cerebro Corazón (BHI), tratado con discos de papel filtro impregnados con 1µl de cada trata- miento por triplicado; T1 (Hidróxido de Calcio + propilenglicol), T2 (Hidróxido de Calcio + paramonoclorofenol), T3 (Hidróxido de Calcio + ampicilina gentamicina + propilenglicol), T4 (Hidróxido de Calcio + Solución Salina Fisiológica), Control positivo (medicamento comercial a base de Hidróxido de Calcio), se incubó a 35°C durante 24h, los halos formados alrededor de cada disco fueron medidos y comparados con la escala de Duraffourd y procesados mediante ANOVA de un factor. Se obtuvo una medida del halo de inhibición de 22,50±3,3 mm, con el trata- miento T3, siendo sumamente sensible. Concluyendo que este resultó el más efectivo en compa- ración el resto de la pruebas in vitro en comparación con el resto de los fármaco investigados.

The high incidence of Enterococcus faecalis in dental procedures is a topic of interest for the health area. This bacterium resists various antimicrobials and its proliferation increases due to its low susceptibility to substances of conventional use such as calcium hydroxide, becoming a of the main causes of root canal failure. The present investigation evaluated the in vitro suscepti- bility of Enterococcus faecalis strain ATCC-29212 to the combination of substances and antibio - tics with calcium hydroxide. The agar diffusion technique was used, inoculating the microorga- nism in Petri dishes with Brain Heart agar (BHI), treated with filter paper disks impregnated with 1µl of each treatment in triplicate; T1 (Calcium Hydroxide + propylene glycol), T2 (Cal- cium Hydroxide + paramonochlorophenol), T3 (Calcium Hydroxide + ampicillin gentamicin + propylene glycol), T4 (Calcium Hydroxide + Physiological Saline Solution), Positive control (Hydroxide-based commercial medicine Calcium), incubated at 35 ° C for 24h, the halos formed around each disc were measured and compared with the Duraffourd scale and processed by one-factor ANOVA. A measure of the inhibition halo of 22.50 ± 3.3 mm was obtained with the T3 treatment, being extremely sensitive. It was concluded that this was the most effective in comparison with the rest of the in vitro tests of the rest of the investigated drugs.

Effect of reciprocating instrumentation on chlorhexidine substantivity on human dentin: chemical analysis followed by confocal laser microscopy

The present research analyzed the reciprocating instrumentation associated to chlorhexidine (CHX) substantivity as its correlation with E. faecalis viability in ex vivo root canals. Eighty extracted single-rooted human teeth were used, being 40 to high-performance liquid chromatography (HPLC) and 40 to confocal laser scanning microscopy (CLSM). In both, teeth were decoronated and the cervical third was prepared. In the CLSM analysis, the root canals were inoculated with E. faecalis for 14 days. Samples were divided into 4 groups (n=10) according to instrumentation technique: no instrumentation and irrigation with distilled water (control); manual instrumentation (K-File); rotary instrumentation (ProTaper Next); and reciprocating instrumentation (Reciproc R25). Two percent chlorhexidine was applied as irrigating substance in experimental groups. Longitudinal grooves resulted in 2 halves root and 20 proof bodies in each group. Samples were divided by chance in two groups (n=10) and the outcomes were evaluated after two days and one week. The retained chlorhexidine and live cells after instrumentation techniques in each evaluation time was measured by HPLC and CLSM, respectively. Specific analysis was applied for experimental tests (p≤0.05). Both rotary as well as reciprocating techniques significantly reduced the amount of chlorhexidine on dentin in all observation periods (p<0.05). After evaluation times, all experimental groups presented lower live cells compared to control, but without statistically difference. Intragroup comparisons in times of evaluation showed no differences in instrumentation techniques, in chlorhexidine retention and number of live cells (p>0.05). Reciprocating instrumentation does not interfere on chlorhexidine substantivity.

Comparative evaluation of antimicrobial potential of herbal extracts on Streptococcus mutans and Enterococcus faecalis An in vitro study / Avaliação comparativa do potencial antimicrobiano de extratos de ervas em Streptococcus mutans e Enterococcus faecalis: estudo in vitro

Though aloe vera extract, green tea extract and coriander oil are proven antimicrobial agents, very little information is available regarding its effects on oral bacteria, Streptococcus mutans, which is responsible for initiating caries and Enterococcus faecalis, responsible for failure of root canal treatment. Objective: To find the antimicrobial activity of aloe vera extract, black tea extract and coriander oil against S. mutans and E. faecalis. Materials and Methods: The agar well diffusion method was used to determine the antibacterial activity of Aloe vera extract, black tea extract and coriander oil. Different concentration of prepared plant extracts and coriander seed oil (50 & 100 µl) was incorporated into the wells and the plates containing S. mutans and E. faecalis were incubated at 37 °C for 24 h. The antibiotic (amoxicillin 30 µl) was used as positive control. Zone Of Inhibition (ZOI) was recorded in each plate. Results: For S. mutans, the maximum ZOI was created by coriander oil with a diameter of 25.00±0.58 mm at 50 µl and for E. faecalis, maximum ZOI was created by aloe vera extract 16.00±0.58 mm at 100 µl concentration which were far better than the control: amoxicillin 30 µl concentration. Conclusion: The extracts of Aloe vera, black tea and coriander oil, showed significant activity against the investigated microbial strains, Streptococcus mutans and Enterococcus faecalis which further helps in the development of new topical agents that help in reducing the numbers of these organisms present in the oral cavity. (AU)

Embora o extrato de aloe vera, extrato de chá verde e óleo de coentro sejam agentes antimicrobianos comprovados, há pouca informação disponível sobre seus efeitos nas bactérias orais, Streptococcus mutans, que é responsável por iniciar cáries e Enterococcus faecalis, responsável pela falha do tratamento de canal radicular. Objetivo: Avaliar a atividade antimicrobiana do extrato de aloe vera, extrato de chá preto e óleo de coentro contra S. mutans e E. faecalis. Materiais e Métodos: O método de difusão em agar foi usado para determinar a atividade antibacteriana do extrato de Aloe vera, extrato de chá preto e óleo de coentro. Diferentes concentrações dos extratos de plantas e óleo de semente de coentro (50 e 100 µl) foram preparados e colocados nos poços e nas placas contendo S. mutans e E. faecalis e foram incubadas a 37°C por 24 h. O antibiótico (amoxicilina 30 µl) foi utilizado como controle positivo. A zona de inibição (ZOI) foi registrada em cada placa. Resultados: Para S. mutans, a ZOI máxima foi obtida com o óleo de coentro com um diâmetro de 25,00 ± 0,58 mm a 50 µl e para E. faecalis, a ZOI máxima foi obtiada pelo extrato de aloe vera 16,00 ± 0,58 mm na concentração de 100 µl, as quais foram melhores do que o controle: concentração de 30 µl de amoxicilina. Conclusão: Os extratos de Aloe vera, chá preto e óleo de coentro apresentaram atividade significativa contra as cepas microbianas investigadas, Streptococcus mutans e Enterococcus faecalis auxiliando no desenvolvimento de novos agentes tópicos visando a redução do número desses organismos presentes no cavidade oral. (AU)

Effects of ClpP protease on biofilm formation of Enterococcus faecalis

Abstract Enterococcus faecalis (E. faecalis), one of the main pathogens responsible for refractory periapical periodontitis and nosocomial infections, exhibits markedly higher pathogenicity in biofilms. Objectives Studies have shown that caseinolytic protease P (ClpP) is involved in biofilm formation. However, to date, few studies have investigated the role of ClpP in the survival of E. faecalis, and in enhancing biofilm formation. Therefore, we investigated the role of ClpP in the formation of E. faecalis biofilms. Methodology In our study, we used homologous recombination to construct clpP deleted and clpP complement strains of E. faecalis ATCC 29212. A viable colony counting method was used to analyze the growth patterns of E. faecalis. Crystal violet staining (CV) and confocal scanning laser microscopy (CLSM) were used to characterize biofilm mass formation and scanning electron microscopy (SEM) was used to observe the biofilm microstructure. Data was statistically analyzed via Student's t-test or one-way analysis of variance (ANOVA). Results The results exhibited altered growth patterns for the clpP deletion strains and depleted polysaccharide matrix, resulting in reduced biofilm formation capacity compared to the standard strains. Moreover, ClpP was observed to increase biofilm formation in E. faecalis. Conclusion Our study shows that ClpP can increase biofilm formation in E. faecalis and emphasizes the importance of ClpP as a potential target against E. faecalis.

Detection of the main multiresistant microorganisms in the environment of a teaching veterinary hospital in Brazil / Detecção dos principais microrganismos multirresistentes no ambiente de um hospital veterinário de ensino no Brasil

Contamination of the veterinary hospital environment with multiresistant pathogens endangers not only hospitalized animals, but also the workplace safety of veterinarians and nurses, animal guardians and, when in case of a teaching hospital, veterinary students. The objective of this study was to map the main points of bacterial contamination of a veterinary teaching hospital in Brazil to identify multiresistant microorganisms and their antimicrobial resistance genes. Samples were collected from 39 different locations of a veterinary school hospital which comprised a pool according to each hospital environment. In certain environments, more than one pool has been collected. All samples were collected in quadruplicates for the selective isolation of the main multiresistant microorganisms: methicillin-resistant Staphylococcus (MRS), vancomycin resistant Enterococcus (VRE), cephalosporinases and/or extended-spectrum beta-lactamase-producing Gram-negative bacteria (ESBL) and Carbapenemase-producing (CP). After isolation and identification of isolates, multiplex-PCR reactions were performed to detect the main genes for each microorganism and antimicrobial susceptibility tests with the main antibiotics used for each bacterial group according to CLSI. Of the 39 veterinary teaching hospital sites collected, all (100%) had at least one of the microorganisms surveyed, and 17.95% (n=7) of the sites were able to isolate the four pathogens. From the 94 pools collected, it was possible to isolate MRS in 81.91% (n=77), VRE in 12.77% (n=12), cephalosporinases and/or ESBL in 62.77% (n=59) and CP in 24.47%. (n=23). Regarding MRS, the mecA gene was detected in all isolates. All isolated VREs were identified as Enterococcus faecalis and presented the vanA gene. Regarding cephalosporinases and/or ESBL, 89.83% (n=53) of the isolates presented the blaTEM gene, 57.63% (n=34) the blaOXA-1 gene, 37.29% (n=22) blaCTX-M gene from some group (1, 2, 9 ou 8/25) and 20.34% (n=12) the blaSHV gene. It was possible to identify the main microorganisms responsible for causing nosocomial infections in humans (VRE, MRS, ESBL and CP) in the veterinary hospital environment, suggesting a source of infection for professionals and students of veterinary medicine, placing a high risk for public health.(AU)

A contaminação do ambiente hospitalar veterinário com patógenos multirresistentes coloca em perigo não apenas os animais hospitalizados, mas também a segurança no local de trabalho de veterinários e enfermeiros, responsáveis por animais e, quando se tratar de um hospital de ensino, estudantes de veterinária. O objetivo deste estudo foi mapear os principais pontos de contaminação bacteriana de um hospital veterinário de ensino no Brasil, identificando microorganismos multirresistentes e seus genes de resistência antimicrobiana. As amostras foram coletadas em 39 locais diferentes de um hospital de escola veterinária, que compreendia um pool de acordo com o ambiente de cada hospital. Em certos ambientes, mais de um pool foi coletado. Todas as amostras foram coletadas em quadruplicados para o isolamento seletivo dos principais microorganismos multirresistentes: Staphylococcus resistente à meticilina (MRS), Enterococcus resistente à vancomicina (VRE), bactérias Gram-negativas produtoras de cefalosporinases e/ou beta-lactamase de espectro estendido (ESBL) e produtoras de carbapenemase (PC). Após o isolamento e identificação dos isolados, foram realizadas reações de PCR multiplex para detectar os principais genes de cada microorganismo e testes de susceptibilidade a antimicrobianos com os principais antibióticos utilizados para cada grupo bacteriano de acordo com o CLSI. Dos 39 locais do VCH coletados, todos (100%) possuíam pelo menos um dos microrganismos pesquisados e 17,95% (n=7) dos locais foram capazes de isolar os quatro patógenos. Dos 94 pools coletados, foi possível isolar MRS em 81,91% (n=77), VRE em 12,77% (n=12), ESBL em 62,77% (n=59) e carbapenemases em 24,47% (n=23). Em relação ao MRS, o gene mecA foi detectado em todos os isolados. Todos os VREs isolados foram identificados como Enterococcus faecalis e apresentaram o gene vanA. Em relação às cefalosporinases e/ou ESBL, 89,83% (n=53) dos isolados apresentaram o gene blaTEM, 57,63% (n=34) o gene blaOXA-1, 37,29% (n=22) o gene blaCTX-M de algum grupo e 20,34% (n=12) o gene blaSHV. Foi possível identificar os principais microrganismos responsáveis por causar infecções nosocomiais em humanos (VRE, MRS, ESBL e CP) no ambiente hospitalar veterinário, sugerindo uma fonte de infecção para profissionais e estudantes de medicina veterinária, colocando alto risco para a saúde pública.(AU)

Comparación de la efectividad antimicrobiana entre hipoclorito de sodio 2, 5% y ácido hipocloroso 5% frente a Enterococcus faecalis: prueba in vitro / Comparison of antimicrobial effectiveness between sodium hypochlorite 2.5% and hypochlorous acid 5% against Enterococcus faecalis: an in vitro test

La terapia endodóntica tiene como uno de sus objetivos lograr la completa desinfección del sistema de conductos radiculares. Por esto, se deben seleccionar sustancias irrigantes que tengan la capacidad de eliminar todo el contenido de dicho sistema. La acción antimicrobiana es una de las características más importantes a tener en cuenta en la elección. El hipoclorito de sodio (NaOCl) tiene capacidad bactericida sobre muchos de los microorganismos de la flora endodóntica. El Enterococcus faecalis es una bacteria altamente resistente a antibacterianos que sobrevive en condiciones extremas. El ácido hipocloroso (HOCl) es una molécula derivada del NaOCl que ha demostrado tener alto poder bactericida sobre cepas patogénicas bucales. El objetivo de este trabajo fue evaluar y comparar la efectividad antimicrobiana in vitro del NaOCl 2.5% y el HOCl al 5% frente a Enterococcus faecalis. Una suspensión de Enterococcus faecalis (ATCC29212), de turbidez 0.5 en escala de McFarland, fue inoculada en varios tubos de ensayo, los cuales contenían cada antimicrobiano. Se dejaron actuar durante 1, 5 y 10 minutos para luego neutralizarlos e inclubarlos a 37º C en condiciones de capnofilia durante 48 hs. Todo el procedimiento se realizó por quintuplicado. Los resultados se midieron mediante recuento de UFC/ml. No se evidenció presencia de Enterococcus faecalis en las placas que contenían la solución de NaOCl al 2.5% como tampoco en aquellas que contenían HOCl al 5%. In vitro, el HOCl y el NaOCl en las concentraciones probadas, eliminaron completamente las cepas de Enterococcus faecalis (AU)

Investigation of Microbial Contamination in the Clinic and Laboratory of the Prosthodontics Department of Dental School

ABSTRACT Objective: To determine the level of clinical contamination in the clinic and laboratory of the prosthodontics department of Kerman Dental School. Material and Methods: Clinical surfaces of the dental units, the laboratory, and the professors' lounge of the prosthodontics department were randomly sampled. The sampled surfaces included the dental units' console, light switch, light handle, headrest, and air-water spray syringe in the clinic, plastering tables, buttons of the vibrator, polishing, and trimmer machines, acryl tables, handles of pressure pot and press machine, handpiece holders, work desks, and drawer handles in the laboratory, and desks, computer mouse and keyboard, telephone sets, and doorknob in the professor's lounge. The samples were examined for the type and growth of microorganisms. The data were entered into SPSS, where they were analyzed using the chi-square test at the 0.05 significance level. Results: Of all the samples taken, 89.9% showed microbial contamination. The most common type of contamination was fungus (34.8%) and the least common types were Enterococcus faecalis and Staphylococcus epidermidis (1.1%). The second and third most common types of bacteria in the samples were Staphylococcus aureus (18%) and Pseudomonas aeruginosa (12.4%), respectively. There was no significant difference between the frequencies of microbial contamination in the clinic, the laboratory, and the professors' lounge. Conclusion: Given the strong chance of cross-infection in the examined department and laboratory, it is necessary to enforce protocols for proper disinfection of surfaces before, between and after treatments.