Serotipos prevalentes de Streptococcus mutans en América Latina / Prevalent serotypes of Streptococcus mutans in Latin America

La microbiota oral está conformada por diversas especies bacterianas que en condiciones normales desempeñan una función protectora del huésped; sin embargo, cuando existe un desequilibrio en el ecosistema, estos microorganismos son capaces de producir diversas manifestaciones como lo es el caso de la caries dental, enfermedad infecciosa producida principalmente por Streptococcus mutans, patógeno capaz de desmineralizar los tejidos duros del diente mediante la fermentación de hidratos de carbono obtenidos de la dieta. Se ha identificado en la pared celular de este microorganismo ocho serotipos que intervienen en la adhesión, agregación y coagregación bacteriana. En los seres humanos S. mutans presenta los serotipos c, e y f, siendo el serotipo c el más prevalente a nivel mundial, el cual se conoce que está asociado a pacientes sanos, a diferencia del e y f que son capaces de invadir las células endoteliales de las arterias coronarias. No obstante, en los últimos años se ha logrado identificar el serotipo k que de igual manera presenta alta capacidad de invadir el endotelio humano, actuando en la patogénesis de las enfermedades cardiovasculares. El objetivo de la presente revisión bibliográfica es lograr cuantificar los serotipos prevalentes de S. mutans en América Latina (AU)

The oral microbiota is made up of various bacterial species that under normal conditions perform a protective function of the host, however, when there is an imbalance in the ecosystem, these microorganisms are capable of producing various manifestations such as caries, an infectious disease. produced mainly by Streptococcus mutans, a pathogen capable of demineralizing the hard tissues of the tooth through the fermentation of carbohydrates obtained from the diet. Eight serotypes involved in bacterial adhesion, aggregation and coaggregation have been identified in the cell wall of this microorganism. In humans, S. mutans presents serotypes c, e, and f, serotype c being the most prevalent worldwide, which is known to be associated with healthy patients, unlike e and f, which are capable of invading the endothelial cells of the coronary arteries. However, in recent years it has been possible to identify serotype k, which also has a high capacity to invade the human endothelium, acting in the pathogenesis of cardiovascular diseases. The objective of this literature review is to quantify the prevalent serotypes of S. mutans in Latin America (AU)

In vitro bacterial adherence on teeth submitted to whitening with musa paradisiaca / Adherencia bacteriana in vitro en dientes sometidos a blanqueamiento con musa paradisiaca

Objetive: To compare in vitro bacterial adherence on teeth submitted to whitening with 50% ethanolic extract of Musa paradisiaca and 35% hydrogen peroxide. Material and Methods: The study was experimental and used 18 premolars that were grouped into: G1 (control), G2 (50% ethanol extract of Musa paradisiaca) and G3 (35% hydrogen peroxide). The teeth were then exposed to a Streptococcus mutans culture for 24 hours, followed by centrifugation in thioglycolate broth. A culture on trypticase soy agar was done with a 1 in 100 dilution, and after 48 hours colony forming units (CFU) were counted. Statistical analysis was performed using the ANOVA test, complemented by the Bonferroni post-hoc. Results: Bacterial adherence was 77x105 CFU/ml in Group 3 using 35% hydrogen peroxide, 40x105 CFU/ml in Group 2 using 50% ethanol extract of Musa paradisiaca, and 89x104 CFU/ml in Group 1 (control). The difference between the three groups was significant (p=0.000). Conclusion: Both whitening methods cause bacterial adherence to the tooth surface, although to a lower degree with Musa paradisiaca.eses.

Objetivo: Comparar la adherencia bacteriana in vitro en dientes sometidos a blanqueamiento con extracto etanólico de Musa paradisiaca al 50% y con peróxido de hidrógeno al 35%. Material y Métodos: Comparar la adherencia bacteriana in vitro en dientes sometidos a blanqueamiento con extracto etanólico de Musa paradisiaca al 50% y con peróxido de hidrógeno al 35%.Resultados: La adherencia bacteriana fue de 77x105 UFC/ml con el peróxido de hidrógeno al 35%, de 40x105 UFC/ml con el extracto etanólico de Musa paradisiaca al 50% y de 89x104 UFC/ml con el control. La diferencia fue significativa entre los tres grupos (p=0.000). Conclusión: Ambos métodos de blanqueamiento causan adherencia bacteriana en la superficie dental, siendo menor con Musa paradisiaca.

Tumor de colon como hallazgo incidental en un paciente con endocarditis por Streptococcus gallolyticus: experiencia desde la práctica clínica / Colon tumor as an incidental finding in a patient with endocarditis due to Streptococcus gallolyticus: experience from clinical practice

El Streptococcus gallolyticus del colon. La fisiopatología que explica este fenómeno implica el aumento local de niveles de lactato puede presentarse como el germen causal de la endocarditis infecciosa en pacientes con lesiones premalignas y malignas, colágeno, fibrinógeno y fibronectina secundario a la hiperactividad metabólica tumoral que genera un ambiente adecuado para el crecimiento y adhesión bacteriana a la pared intestinal y posterior translocación al torrente sanguíneo. Simultáneamente, se establece la presencia de infecciones secundarias por la formación de biofilms, tanto a nivel colorrectal como en válvulas cardíacas. El objetivo del manuscrito es un mapeo en la literatura médica disponible sobre la correlación entre la endocarditis por Streptococcus gallolyticus y las lesiones premalignas y malignas de colon. Simultáneamente, exponer la experiencia clínica de un hombre de 82 años con diagnóstico de endocarditis por Streptococcus gallolyticus y el hallazgo incidental de pólipos adenomatosos del colon(AU)

Streptococcus gallolyticus can present as the causative germ of infective endocarditis in patients with premalignant and malignant lesions of the colon. The pathophysiology that explains this phenomenon involves the local increase in lactate that can be presented as the causal germ of infective endocarditis in patients with premalignant and malignant lesions, collagen, fibrinogen, and fibronectin levels secondary to tumor metabolic hyperactivity, which generates a suitable environment for bacterial growth and adhesion to the intestinal wall and subsequent translocation to the bloodstream. Simultaneously, the presence of secondary infections is established due to the formation of biofilms, both at the colorectal level and in the heart valves. The objective of the manuscript is a mapping in the available medical literature on the correlation between Streptococcus gallolyticus endocarditis and premalignant and malignant colonic lesions. Simultaneously, to present the clinical experience of an 82-year-old man diagnosed with Streptococcus gallolyticus endocarditis and the incidental finding of adenomatous polyps of the colon(AU)

Antiadhesion and antibiofilm potential of Fagonia indica from Cholistan desert against clinical multidrug resistant bacteria / Potencial de antiadesão e antibiofilme de Fagonia indica do deserto do Cholistão contra bactérias multirresistentes clínicas

High resistance to antimicrobials is associated with biofilm formation responsible for infectious microbes to withstand severe conditions. Therefore, new alternatives are necessary as biofilm inhibitors to control infections. In this study, the antimicrobial and antibiofilm activities of Fagonia indica extracts were evaluated against MDR clinical isolates. The extract exhibited its antibiofilm effect by altering adherence and disintegration of bacterial cell wall. Fagonia indica has antibacterial effect as minimum inhibitory concentration (MIC) values ranging from 125 to 500 µg mL-1 and minimum bactericidal concentration (MBC) value was 500-3000 µg mL-¹ against multidrug resistant (MDR) clinical isolates. The extract exhibited its antibiofilm effect by altering adherence and disintegration of bacterial cell wall. Fagonia indica had antibacterial effect as minimum inhibitory concentration (MIC) values ranging from 125 to 500 µg mL-¹ and minimum bactericidal concentration (MBC) value was 500-3000 µg mL-¹ against MDR isolates. The maximum inhibitory effects of Fagonia indica chloroform extract on biofilm formation was observed on Staphylococcus aureus (71.84%) followed by Klebsiella pneumoniae (70.83%) after 48 hrs showing that inhibition is also time dependent. Our results about bacterial cell protein leakage indicated that MDR isolates treated with chloroform extract of Fagonia indica showed maximum protein leakage of K. pneumoniae (59.14 µg mL-¹) followed by S. aureus (56.7 µg mL-1). Cell attachment assays indicated that chloroform extract resulted in a 43.5-53.5% inhibition of cell adherence to a polystyrene surface. Our results revealed that extracts of Fagonia indica significantly inhibited biofilm formation among MDR clinical isolates, therefore, could be applied as antimicrobial agents and cost effective biofilm inhibitor against these MDR isolates.

A alta resistência aos antimicrobianos está associada à formação de biofilme responsável por micróbios infecciosos para suportar condições severas. Portanto, novas alternativas são necessárias como inibidores de biofilme para controlar infecções. Neste estudo, as atividades antimicrobiana e antibiofilme dos extratos de Fagonia indica foram avaliadas contra isolados clínicos MDR. O extrato exibiu seu efeito antibiofilme ao alterar a aderência e a desintegração da parede celular bacteriana. Fagonia indica tem efeito antibacteriano com valores de concentração inibitória mínima (CIM) variando de 125 a 500 µg mL-¹, e valor de concentração bactericida mínima (MBC) de 500-3000 µg mL-1 contra isolados clínicos multirresistentes (MDR). O extrato exibiu seu efeito antibiofilme ao alterar a aderência e a desintegração da parede celular bacteriana. Fagonia indica teve efeito antibacteriano com valores de concentração inibitória mínima (CIM) variando de 125 a 500 µg mL-¹, e concentração bactericida mínima (MBC) de 500-3000 µg mL-¹ contra isolados MDR. Os efeitos inibitórios máximos do extrato de clorofórmio Fagonia indica na formação de biofilme foi observada em Staphylococcus aureus (71,84%), seguido por Klebsiella pneumoniae (70,83%) após 48 horas, mostrando que a inibição também é dependente do tempo. Nossos resultados sobre extravasamento de proteínas de células bacterianas indicaram que isolados MDR tratados com extrato clorofórmico de Fagonia indica apresentaram vazamento máximo de proteínas de K. pneumoniae (59,14 µg mL-¹), seguido por S. aureus(56,7 µg mL-¹). Ensaios de fixação de células indicaram que o extrato de clorofórmio resultou em uma inibição de 43,5-53,5% da aderência das células a uma superfície de poliestireno. Nossos resultados revelaram que extratos de Fagonia indica inibiram [...].

An in vitro evaluation of surface roughness, color stability and bacterial accumulation of lithium disilicate ceramic after prophylactic periodontal treatment / Avaliação in vitro da rugosidade superficial, estabilidade de cor e acúmulo bacteriano em cerâmica de dissilicato de lítio após tratamento de profilaxia periodontal

Objective: To evaluate the effect of scaling procedures using different ultrasonic tips on the surface roughness, color stability and bacterial accumulation of lithium disilicate ceramic. Material and Methods: Scaling procedure was carried out using ultrasonic scaler (Satalec, Acteon, North America) with stainless-steel tip (US), titanium tip (UT) and plastic tip (UP), on disc shaped lithium disilicate samples cemented into a cavity prepared onto the labial surface of freshly extracted bovine teeth (10 samples per group). The samples were stored in coffee solution in an incubator at 37°C for 12 days, which is equivalent to 1 year of coffee consumption. The surface roughness was measured before and after the scaling procedure using a profilometer and atomic force microscopy. The color parameters were measured before and after scaling and staining procedures using VITA Easyshade Advance 4.0 according to the CIE L*a*b* color order system. The samples were then incubated with Streptococcus mutans (S. mutans) suspension. After incubation, the plates with 30 to 300 typical colonies of S. mutans were counted in a colony counter and mean values of colony forming units were obtained (CFU/mL). Results:The titanium scaling tip showed a statistically significant higher mean values of change in surface roughness ΔRa and bacterial count than the plastic scaling tip. Color changes (ΔE) were not a statistically significant among the groups. The results showed a statistically significant positive (direct) correlation between surface roughness and color change (p = 0.012) and also between surface roughness and bacterial count (p = 0.00). Conclusion: Within the limitations of this study, titanium scaling instruments cause irreversible surface alterations of lithium disilcate ceramics which was in direct correlation to the color changes and bacterial accumulation; therefore, dentists should proceed with caution when scaling lithium disilicate surfaces. The findings of the current study may indicate the need for instruments or equipment that can remove plaque and calculus without causing surface damage (AU)

Introdução: Avaliar o efeito de procedimentos de raspagem com diferentes pontas de ultrassom na rugosidade superficial, estabilidade de cor e acúmulo bacteriano em cerâmica de dissilicato de lítio. Material e Métodos: O procedimento de raspagem foi realizado usando um aparelho de ultrassom (Satalec, Acteon, América do Norte) com ponta de aço inoxidável (US), ponta de titânio (UT) e ponta de plástico (UP), em amostras de dissilicato de lítio em forma de disco cimentadas em uma cavidade preparada na superfície vestibular de dentes bovinos recém-extraídos (10 amostras por grupo). As amostras foram armazenadas em solução de café em incubadora a 37 ° C por 12 dias, o que equivale a 1 ano de consumo de café. A rugosidade da superfície foi medida antes e após o procedimento de raspagem usando um perfilômetro e um microscópio de força atômica. Os parâmetros de cor foram medidos antes e depois dos procedimentos de raspagem e armazenagem no café usando VITA Easyshade Advance 4.0 de acordo com o sistema de ordem de cores CIE L*a*b*. As amostras foram incubadas com suspensão de Streptococcus mutans (S. mutans). Após a incubação, as placas com 30 a 300 colônias típicas de S. mutans foram contadas em contador de colônias e obtidos os valores médios das unidades formadoras de colônias (UFC / mL). Resultados: A ponta de titânio mostrou valores estatisticamente maiores de mudança na rugosidade da superfície ΔRa e contagem de bactérias do que a ponta de raspagem de plástico. A mudança de cor (ΔE) não foi estatisticamente significativa entre os grupos. Os resultados mostraram uma correlação positiva (direta) estatisticamente significativa entre rugosidade superficial e alteração de cor (p = 0,012) e também entre rugosidade superficial e contagem bacteriana (p = 0,00). Conclusão: Dentro das limitações deste estudo, os instrumentos de raspagem de titânio causam alterações irreversíveis na superfície das cerâmicas de dissilicato de lítio que estão em correlação direta com as mudanças de cor e o acúmulo de bactérias. Portanto, os dentistas devem proceder com cautela ao realizar raspagem em superfícies de dissilicato de lítio. Os resultados deste estudo podem indicar a necessidade de instrumentos ou equipamentos que possam remover a placa e cálculo sem causar danos à superfície. (AU)

Influence of EDTA and its Association with Benzalkonium Chloride on Enterococcus faecalis Adhesion to Dentin / Influencia del EDTA y su Asociación con Cloruro de Benzalconio en la Adhesión de Enterococcus faecalis a la Dentina

ABSTRACT: The aim of this in vitro study was to investigate the influence of ethylenediaminetetraacetic acid (EDTA) associated with the benzalkonium chloride (BAK) on the adhesion and formation of Enterococcus faecalis biofilms attached to coated dentin. Discs standard bovine dentin blocks were treated with the coating materials evaluated: Saline solution (control), 17 % EDTA, 17 % EDTA associated with 1 % BAK for 5 minutes and subsequently washed with saline solution. Afterwards, biofilms of E. faecalis (ATCC 29212) were grown on the surface of coated dentin blocks for time intervals of 1 hour and 7 days (n = 20) and were subsequently washed with phosphate-buffered saline (PBS). Bacterial viability and total biovolume were analyzed by confocal laser scanning microscopy (CLSM) using the Live/Dead technique. Nonparametric Kruskal-Wallis followed by Dunn tests were used to determine statistical differences (a = 5 %). The 17 % EDTA + 1 % BAK group showed significantly lower biovolume and bacterial viability values at the end of 1 hour (p < 0.05). After 7 days of contamination, the 17 % EDTA and 17 % EDTA + 1 % BAK groups showed similar results that differed statistically from those of the control group (p < 0.05). The saline solution group showed higher values. The use of BAK associated with EDTA on dentin blocks surfaces before exposure to contamination was able to interfere in the adhesion of E. faecalis to dentin. Also, dentin treatment by BAK associated with a chelating agent influences the secondary biofilm formation, which could have important effects on the long-term success of root canal treatment.

RESUMEN: El objetivo del estudio consistió en investigar in vitro, la influencia del ácido etilendiamino-tetraacético (EDTA) con cloruro de benzalconio (BAK) en la adhesión y formación de biopelículas de Enterococcus faecalis a la dentina. Discos de dentina bovina fueron tratadas con solución salina (control), 17 % de EDTA, 17% de EDTA asociado con 1 % de BAK durante 5 minutos y lavadas con solución salina. Las biopelículas de E. faecalis (ATCC 29212) se cultivaron sobre los discos de dentina durante intervalos de tiempo de 1 hora y 7 días (n = 20), lavados con solución salina tamponada con fosfato (PBS). La viabilidad bacteriana y el biovolumen total se analizaron mediante microscopía de barrido por láser (CLSM) utilizando la técnica Live / Dead. Se realizó prueba no paramétrica de Kruskal-Wallis, seguida por Dunn con una diferencia estadística (a = 5 %). El grupo de 17 % EDTA + 1 % BAK mostró valores significativamente menores de biovolumen y viabilidad bacteriana al final de 1 hora (p < 0,05). Después de 7 días de contaminación, los grupos de 17 % EDTA y 17 % EDTA + 1 % BAK mostraron resultados similares que diferían estadísticamente del grupo control (p < 0,05). La solución salina mostró valores más altos. La asociación de BAK con EDTA antes de la contaminación interfirió en la adhesión de E. faecalis. Además, el tratamiento de la dentina por BAK asociado con EDTA influye en la formación de biopelículas secundarias, lo que podría tener efectos importantes sobre el éxito a largo plazo del tratamiento del conducto radicular.

Influência da adesão bacteriana em resina composta Bulk fill submetida a diferentes protocolos de acabamento e polimento: estudo in vitro / Influence of bacterial adhesion on Bulk fill composite resin submitted to different finishing and polishing protocols: in vitro study

Objetivo: avaliar a adesão bacteriana do Streptococcus mutans na superfície de uma resina composta do tipo incremento único submetida a diferentes protocolos de polimento. Materiais e métodos: foram realizadas 60 amostras nas quais foram divididas aleatoriamente em 6 grupos (n=10) de diferentes tratamentos de superfície. Cinco amostras de cada grupo foram separadas e submetidas ao estudo de adesão bacteriana, das quais duas foram analisadas pela microscopia eletrônica de varredura. Foram contabilizadas as unidades formadoras de colônias UFC/ml de modo manual e realizada a média e desvio padrão de cada grupo. De acordo com os resultados analisados através do teste de One Way ANOVA e comparações múltiplas de Tukey observou-se uma diferença estatisticamente significativa entre os grupos. Resultados: os valores de UFC/ mL variaram de 0 para o grupo American Burrs a 8,64 para o grupo Dhpro. Os grupos Jota e Dhpro não diferiram estatisticamente entre si (p=0,71), porém diferiram dos demais grupos avaliados (p=0,45). Os grupos American Burrs e o controle negativo não diferiram estatisticamente entre si (p>0.999) e diferiram dos demais grupos testados (p=0,20). O grupo de controle positivo diferiu estatisticamente dos outros grupos (p=0,02) assim como o grupo KG (p=0,01). Conclusão: Diante dos resultados obtidos, pode-se concluir que, a superfície da resina Bulk Fill One submetida a diferentes protocolos de polimento e mesmo sem ter passado por nenhum tratamento de superfície é passível de adesão bacteriana seja por contagem manual ou microscopia eletrônica de varredura(AU)

Objective: To evaluate the bacterial adhesion of Streptococcus mutans on the surface of a single increment composite resin submitted to different polishing protocols. Materials and methods: 60 samples were randomly divided into 6 groups (n = 10) of different surface treatments. Five samples from each group were separated and submitted to the bacterial adhesion study, two of which were analyzed by scanning electron microscopy. The UFC/ml colony forming units were accounted for manually and the mean and standard deviation of each group were performed. According to the results analyzed by the One Way ANOVA test and Tukey's multiple comparisons, a statistically significant difference was observed between the groups. Results: The values ranged from 0 for the American Burrs group to 8.64 for the Dhpro group. The Jota and Dhpro groups did not differ statistically (p = 0.71), but differed from the other groups evaluated (p = 0.45). The American Burrs and negative control groups did not differ statistically (p> 0.999) and differed from the other groups tested (p = 0.20). The positive control group differed statistically from the other groups (p = 0.02) as did the KG group (p = 0.01). Conclusion: It can be concluded that the surface of the Bulk Fill One resin submitted to different polishing protocols and even without any surface treatment is susceptible to bacterial adhesion either by manual counting or scanning electron microscopy(AU)

Antimicrobial Orthodontic Wires Coated with Silver Nanoparticles

Abstract Conventional orthodontic treatment with the use of stainless steel may be detrimental to oral health by promoting demineralizing lesions appearance and increasing adhesion and formation of bacterial biofilm, inducing the development of cavities. An alternative that has been researched to reduce the side effects of orthodontic treatment is the coating of materials with antimicrobial nanoparticles. Nanometric- sized particles increase their surface area and contact with the microbial membrane, consequently intensifying their bacteriostatic and bactericidal effect. In this work, hydrothermal synthesis, a "green" process was used to attach silver nanoparticles (AgNPs) to the surface of two different brands of orthodontic wires. The coated materials were analyzed for their physicochemical properties by scanning electron microscopy (SEM), X-ray diffraction (XRD) and differential scanning calorimetry (DSC), which showed the distribution of AgNPs along the wires without modifying their properties. In the microbiological test, one of the brands showed a statistically significant difference in microbial adhesion and biofilm formation by Staphylococcus aureus and Streptococcus mutans. Results lead to the conclusion that antimicrobial orthodontic wires coated with silver nanoparticles through hydrothermal synthesis is a promising material for the improvement of orthodontic treatment.

"Amar" el índice de O'Leary / The O'Leary index, a.k.a. the "Love" index

La detección y cuantificación de placa dental bacteriana se considera básica en la práctica de la estomatología. El índice O'Leary constituye una herramienta sencilla que mide la cantidad de placa dental bacteriana en los dientes, y resulta uno de los más efectivos en la evaluación de la higiene bucal. La connotación que tiene la higiene bucal en varias esferas de la vida quizás llevó a que este índice fuera bautizado en Cuba como índice de Love (Amor); por lo que nos proponemos esclarecer la conveniencia del empleo de la denominación internacional de este(AU)

Detection and quantification of bacterial dental plaque is considered to be crucial in dental practice. The O'Leary index is a simple tool to measure the amount of bacterial dental plaque on teeth and one of the most effective means to evaluate oral hygiene. The connotation of oral hygiene in several spheres of life is probably the reason why this index is also known in Cuba as the Love Index. We intend to shed light on the advisability of using the international term(AU)

Bacterial colonization of composite resins used with direct technique: a brief review

In restorative dentistry, the use of composite resins with direct technique for the replacement of missing tooth structure is very common. One drawback is that surface roughness allows the adherence of microorganisms and the formation of dental plaque, being the polishing technique a key stage in the restoration process. The aim of this paper is to review the process of bacterial colonization of composite resins used with direct technique. According to in vitro studies, bac-terial adhesion on microhybrid composite resins is 3.91 ± 0.52 UFC and on nanohybrid is 3.34 ± 0.74 UFC. Resins with particle size of 2.5 micrometers contained a greater volume of biofilms and enabled adhesion of S. mutans; in turn, resins with particle size of 0.1 to 0.4 micrometers showed lower bacterial adherence. As summary, the degree of bacterial colonization depends on hygiene, polishing technique and composition of restorative material: the bigger the particle size, the greater the adhesion of bacterial plaque.

Adhesión Bacteriana en Hilo de Sutura de Seda Negra y Nylon Post Extracción Dental Simple: Ensayo Clínico Controlado / Bacterial Adhesion in Black Silk Suture Thread and Nylon Post Simple Dental Extraction: Controlled Clinical Trial

RESUMEN: El objetivo de este estudio fue comparar los hilos de sutura de seda negra y la sutura nylon con respecto a la adhesión bacteriana post extracción dental simple de piezas posteriores. El presente trabajo se desarrolló en la Clínica Odontológica y el Laboratorio de Microbiología de la Unidad de Ciencias Biomédicas y Biotecnología de la Universidad Privada Antenor Orrego (Trujillo, Perú), entre agosto y setiembre de 2014. Se trabajó con 19 unidades de muestreo para hilo de seda negra y 19 para nylon. El procedimiento de exodoncia para todos los pacientes fue estandarizado. Luego de la extracción, se procedió a suturar la herida quirúrgica, colocando dos puntos circunferenciales, uno con cada tipo de hilo. A los 7 días, los hilos fueron retirados y sometidos a análisis microbiológico. La adhesión bacteriana de los hilos de sutura seda negra y nylon fue comparada empleando el test de Wilcoxon. Además la adhesión bacteriana de cada hilo fue comparada con la adhesión en hilos estériles (control) empleando el test de Mann-Whitney para una p<0,005. Al comparar la adhesión bacteriana de ambos hilos, se encontró diferencia entre ellos (p=0,027), correspondiendo mayor adhesión al hilo de nylon. La adhesión bacteriana fue mayor en el hilo de sutura de nylon comparado con el hilo de sutura de seda negra.

ABSTRACT: The objective of the study was to compare black silk suture threads and nylon suture with respect to bacterial adhesion after simple dental extraction of posterior pieces. The present study was developed in the Clínica Estomatológica and the Laboratorio de Microbiología of the Unidad de Ciencias Biomédicas y Biotecnología de la Universidad Privada Antenor Orrego (Trujillo, Peru), between August and September 2014. We worked with 19 units sampling for black silk thread and 19 for nylon. The procedure of exodontia for all patients was standardized. After the extraction, the surgical wound was sutured, placing two circumferential points, one with each type of thread. After 7 days, the threads were removed and subjected to microbiological analysis. The bacterial adhesion of the black silk and nylon suture strands was compared using the Wilcoxon test. In addition, the bacterial adhesion of each strand was compared with the adhesion in sterile strands (control) using the Mann-Whitney test for p <0.005. When comparing the bacterial adhesion of both threads, a difference was found between them (p = 0.027), corresponding greater adhesion to the nylon thread. Bacterial adhesion was higher in nylon suture compared to black silk suture.

Efeito da pigmentação extrínseca nas cerâmicas à base de dissilicato de lítio submetidas aos processos de desgaste e biodegradação nas propriedades mecânicas e aderência bacteriana / Effect of extrinsic pigmentation on lithium disilicate-based ceramics subjected to wear and biodegradation processes on mechanical properties and bacterial adherence

O objetivo deste estudo foi avaliar se há alteração no comportamento mecânico e na aderência microbiológica da cerâmica à base de dissilicato de lítio com a técnica de pigmentação extrínseca aplicada, após ser submetida a diferentes condições experimentais. Foram confeccionadas 160 amostras, divididas em grupos com e sem pigmentação (n=80). Destes, cada grupo foi subdividido em Controle, Desgate, Biodegradação e Desgaste com Biodegradação (n=20).15 amostras de cada subgrupo foram submetidas ao teste de resistência à flexão e 5 para o teste de aderência microbiológica. As amostras passaram anteriormente por testes complementares para caracterização da superfície (rugosidade, perfilometria volumétrica e microscopia eletrônica de varredura (MEV)). Os resultados foram submetidos a análise estatística descritiva (média e desvio padrão) e inferencial, mediante o teste paramétrico de análise de variância (ANOVA) dois fatores e teste de Tukey ( = 0,05). O fator pigmentação extrínseca influenciou negativamente no comportamento mecânico da cerâmica, apresentando significância estatística (p = 0,000), assim como a interação entre o tipo de condição experimental e a pigmentação (p = 0,020). Entretanto, na aderência microbiológica, foi a condição experimental que influenciou negativamente no comportamento microbiológico (p = 0,000), assim como a interação entre a condição experimental e a pigmentação (p = 0,000). Nas análises complementares, observou-se que a interação entre os fatores aumentou a rugosidade superfial (p = 0,000) e aumentou o volume perdido pelo desgatse (p = 0,040). As microscopias da superficie mostram as características de cada grupo, mostrando as diferenças entre as condições experimentais com e sem pigmentação extrínseca. E as microscopias da aderência microbiológica ilustram e confirmam os resultados obtidos no teste estatístico. Concluiu-se que a pigmentação extrínseca altera as propriedades mecânicas da cerâmica de dissilicato de lítio, reduzindo a resistência à flexão e aumentando a rugosidade superficial e o desgaste. Porém, a aderência microbiológica foi aumentada pela condição experimental. Entretanto, a interação entre os fatores contribuiu para esse aumento e para agravar a alteração nas propriedades mecânicas(AU)

The objective of this study was to evaluate the mechanical and microbiological behavior of the ceramics based on lithium disilicate with extrinsic characterization. For this, 160 discs were made, divided into two large groups, with extrinsec characterization and without, after which each was divided into four groups (n = 20): Control, Wear, Biodegradation and Biodegradation with Wear. Fifteen samples from each group were submitted to the flexural strength test and 5 submitted to the microbiological adherence test. Prior to the destructive test of flexural strength, the representative samples of each group underwent complementary tests for surface characterization. The results were submitted to descriptive statistical analysis (mean and standard deviation) and inferential, using the parametric analysis of variance (ANOVA) two way and Tukey test ( = 0,05). The extrinsec characterization factor influenced the mechanical behavior of the ceramic, presenting statistical significance (p = 0.000), as well as the interaction between the type of experimental condition and the extrinsec characterization (p = 0.020). However, in the microbiological adherence, it was the experimental condition that influenced the microbiological behavior (p = 0.000), as well as the interaction between the experimental condition and the extrinsec characterization (p = 0.000). It was concluded that the makeup influenced the mechanical behavior of the ceramic, and the experimental condition influenced the microbiological adherence. The interaction between the factors influenced both the mechanical behavior and the microbiological adherence(AU)

Probiotics study with Streptococcus salivarius and its ability to produce bacteriocins and adherence to KB cells / Estudo de probióticos Streptococcus salivarius e sua habilidade de produzir bacteriocinas e aderência à células KB

Abstract Introduction Streptococcus salivarius is a dominant oral species and the best suitable candidate for probiotic of the oral cavity. Since Streptococcus salivarius is able to produce bacteriocins against Streptococcus pyogenes interest has been focused on the use of it as a probiotic to avoid sore throats by Streptococcus pyogenes. Objective This study is for selecting Streptococcus salivarius strains for potential use as probiotics for the oral mucosa, that is, production of bacteriocin against Streptococcus pyogenes and the ability to bind to KB cells. Material and method Tongue material from 45 students was collected and seeded on Mitis Salivarius Agar plaques. The strains were tested by the production of bacteriocin-like substances (BLIS) against S. pyogenes, biochemically and PCR for identification of S. salivarius. The best strains were tested for adherence to KB cells. Briefly, S. salivarius strains were cultured in broth, washed and suspended at 108cells/ml. KB cells were inoculated into plaques, washed and incubated with the bacteria, for adhesion. These were washed for lysis of the KB cells and release bacteria for determination of CFU. Result The bacteriocin test showed that 133 strains presented inhibition of S. pyogenes. The samples tested for adhesion to KB cells, presented different profiles and only three strains presenting high adhesion capacity. Conclusion The selection of strains of Streptococcus salivarius with high inhibitory activity against Streptococcus pyogenes, as well as adherence to KB cells leads us to the next future step, that is, to use the best strains for in vivo colonization tests

Resumo Introdução Streptococcus salivarius é uma espécie dominante na cavidade bucal e tem sido indicada como um ótimo candidato para uso como probiótico. Visto que a espécie Streptococcus salivarius é capaz de produzir bacteriocinas contra Streptococcus pyogenes, desenvolveu-se interesse no uso desse microrganismo como probiótico, para evitar amigdalites causadas por Streptococcus pyogenes. Objetivo A pesquisa em questão tem o objetivo de selecionar cepas de Streptococcus salivarius para seu uso potencial como probióticos na cavidade bucal, ou seja, produção de bacteriocinas contra Streptococcus pyogenes e habilidade de aderência à células KB. Material e método Coletou-se material de língua de 45 estudantes e semeou-se em placas de ágar Mitis Salivarius. As amostras foram testadas para verificar a produção de substâncias semelhantes à bacteriocina (BLIS) contra S. pyogenes, bioquimicamente e através de PCR para identificação de S. salivarius. As melhores cepas foram testadas quanto aderência à células KB. Resumidamente, as cepas de S. salivarius foram cultivadas em caldo, lavadas e suspensas à correspondência de 108 cels/ml. As células KB foram inoculadas em placas, lavadas e incubadas com as bactérias, para adesão. Estas foram lavadas para lise das células KB e liberação das bactérias para determinação de UFC. Resultado O teste de bacteriocina, mostrou que 133 cepas apresentaram atividade inibitória contra Streptococcus pyogenes. As cepas testadas para aderência à células KB, apresentaram diferentes perfis e somente três com alta capacidade de adesão. Conclusão: A seleção de cepas de Streptococcus salivarius com alta atividade inibitória contra Streptococcus pyogenes, bem como aderência a células KB, pode nos levar ao próximo passo, ou seja, o uso das melhores cepas para o estudo de colonização in vivo.

Influence of the incorporation of triclosan methacrylate on the physical properties and antibacterial activity of resin composite

Abstract The incorporation of antimicrobials in the composites as an attempt to reduce bacterial adhesion without jeopardizing mechanical properties is a challenge for Dentistry. Objective: To evaluate the bacterial adhesion and physical properties of a composite containing the methacrylate triclosan- derivative monomer (TM). Methodology: TM was synthesized and added to an experimental composite. Samples were divided into two groups: Control and TM (13.4 wt%). Antibacterial Activity: Three specimens of each material were prepared and placed on bacterial suspensions of Streptococcus mutans for 1, 5 and 10 days. After these periods the counting of the colonies (log10) was performed. Assays was performed in triplicate. Physical Properties: Three-body Abrasion (TBA): Ten specimens of each material were prepared and stored at 37°C/24 h. The surface roughness (Ra) and hardness (KHN) were analyzed. Next, the specimens were submitted to abrasive wear (30,000 cycles) and re-evaluated for Ra and KHN; Sorption/solubility (SS): cylindrical specimens (n=10) were prepared and weighted. The specimens were immersed in deionized water for 7 days at 37°C and then their weight was verified again. SS were calculated using accepted formulas; Diametral tensile strength (DTS): specimens (n=10) underwent test performed in an Instron universal testing machine at a crosshead speed of 1 mm/min. Data were submitted to appropriate statistical tests according to data distribution and assay (p<0.05). Results: Bacterial Adhesion: TM showed a significant reduction on biofilm accumulation in the evaluated periods: 1 day (1.537±0.146); 5 days (2.183±0.138) and 10 days (4.469±0.155) when compared with Control: 1 day (4.954±0.249); 5 days (5.498±0.257) and 10 days (6.306±0.287). Physical Properties: For TBA, SS and DTS no significant difference was found between groups Control and TM. The incorporation of methacrylate triclosan-based monomer in the experimental composite reduce bacterial adhesion of S. mutans and did not affect important polymer properties.

Molecular analysis, biofilm formation, and susceptibility of methicillin-resistant staphylococcus aureus strains causing community- and health care-associated infections in central venous catheters

Abstract INTRODUCTION: The behavior of methicillin-resistant Staphylococcus aureus (MRSA) isolated from central venous catheter-related infection was evaluated to determine its biofilm potential, antimicrobial resistance, and adhesion genes. METHODS: A total of 1,156 central venous catheters (CVC) were evaluated to screen for pathogens. Antimicrobial sensitivity, biofilm formation potential, and molecular analysis of MRSA were examined following standard guidelines. RESULTS: Of the 1,156 samples, 882 (76%) were colonized by bacteria or candida. Among the infected patients, 69% were male and 36% were female with median age of 32 years. Staphylococcus aureus infected 39% (344/882) of CVCs in patients. Of the 59% (208/344) of patients with MRSA, 57% had community acquired MRSA and 43% had hospital acquired MRSA. Linezolid and vancomycin killed 100% of MRSA; resistance levels to fusidic acid, doxycycline, clindamycin, azithromycin, amikacin, trimethoprim-sulfamethoxazole, gentamycin, tobramycin, and ofloxacin were 21%, 42%, 66%, 68%, 72%, 85%, 95%, 97%, and 98% respectively. Strong biofilm was produced by 23% of samples, moderate by 27%, and weak by 50% of MRSA. The presence of adhesion genes, sdrC and sdrD (90%), eno (87%), fnbA (80%), clfA and sdrE (67%), fnbB, sdrD (61%), and cna (51%), in most MRSA samples suggested that the adhesion genes are associated with biofilm synthesis. CONCLUSIONS: The superbug MRSA is a major cause of CVC-related infection. Antibiotic resistance to major classes of antibiotics and biofilm formation potential enhanced superbug MRSA virulence, leading to complicated infection. MRSA causes infection in hospitals, communities, and livestock.

In vitro antimicrobial effect of bioadhesive oral membrane with chlorhexidine gel

Abstract This study aimed to evaluate in vitro the antimicrobial effect of a bioadhesive chitosan-based oral membrane with chlorhexidine for local treatment of infections in the oral tissues. Five oral membranes of different compositions were tested: 5% chitosan (G1); 5% chitosan ± 0.2% chlorhexidine (G2), 5% chitosan ± 0.6% chlorhexidine (G3), 5% chitosan ± 1.0% chlorhexidine (G4), and 5% chitosan ± 2.0% chlorhexidine (G5). Also, five gel types were tested according to the following compositions: 5% chitosan gel (G6), 0.2% chlorhexidine gel (G7), 2.0% chlorhexidine gel (G8), 5% chitosan gel ± 0.2% chlorhexidine gel (G9), and 5% chitosan gel ± 2.0% chlorhexidine gel (G10). The antimicrobial action of the samples was tested against Candida albicans and Streptococcus mutans through antibiogram by measuring the inhibition halos. Data were statistically analyzed by Kruskal-Wallis and one-way ANOVA followed by Tukey test (p<0.05). The 2.0% chlorhexidine membrane (G5) and the disks containing 2.0% chlorhexidine gel (G8) showed the greatest inhibition halos for both microorganisms, with statistically significant difference when compared to others tested groups (p=0.008) only for Candida albicans inhibitions results. All the other formulations of membranes and gels showed inhibition halos, but without statistically significant difference. The bioadhesive chitosan-based oral membrane with 2% chlorhexidine and 2% chlorhexidine gel were the most effective in inhibiting the tested microorganisms.

Resumo O objetivo deste estudo foi avaliar in vitro o efeito antimicrobiano de uma bandagem oral bioadesiva de quitosana com clorexidina para o tratamento de infecções dos tecidos orais. Cinco bandagens de diferentes composições foram testadas: Quitosana 5% (G1); Quitosana 5% ± clorexidina a 0,2% (G2), Quitosana 5% ± clorexidina a 0,6% (G3), Quitosana 5% ± clorexidina a 1,0% (G4) e Quitosana 5% ± clorexidina a 2,0% (G5). Foram testados também 5 tipos de géis nas seguintes composições: Gel de Quitosana 5% (G6), Gel de clorexidina a 0,2% (G7), Gel de clorexidina a 2,0% (G8), Gel de Quitosana 5% ± clorexidina a 0,2% (G9) e Gel de Quitosana 5% ± clorexidina a 2,0% (G10). A ação antimicrobiana das amostras foi testada contra Candida albicans e Streptococcus mutans por meio do antibiograma, medindo o halo de inibição. Os dados foram analisados pelo teste de Kruskal-Wallis e ANOVA a um critério seguido pelo teste de Tukey (p<0,05). A membrana com 2,0% de clorexidina (G5) e os discos contendo gel com 2,0% de clorexidina (G8) apresentaram os maiores halos de inibição para os dois microrganismos, com diferença estatisticamente significativa em relação aos demais grupos testados (p=0,008) apenas nos resultados de inibição de C. albicans. Todas as outras formulações de membranas e géis apresentaram halo de inibição, mas sem diferença estatisticamente significativa. A bandagem oral bioadesiva de quitosana com gel de 2% de clorexidina foi a mais efetiva em inibir os microrganismos testados.

Biofilm formation by Staphylococcus aureus and Salmonella spp. under mono and dual-species conditions and their sensitivity to cetrimonium bromide, peracetic acid and sodium hypochlorite

Abstract The aim of this study was evaluated the biofilm formation by Staphylococcus aureus 4E and Salmonella spp. under mono and dual-species biofilms, onto stainless steel 316 (SS) and polypropylene B (PP), and their sensitivity to cetrimonium bromide, peracetic acid and sodium hypochlorite. The biofilms were developed by immersion of the surfaces in TSB by 10 d at 37 °C. The results showed that in monospecies biofilms the type of surface not affected the cellular density (p > 0.05). However, in dual-species biofilms on PP the adhesion of Salmonella spp. was favored, 7.61 ± 0.13 Log10 CFU/cm2, compared with monospecies biofilms onto the same surface, 5.91 ± 0.44 Log10 CFU/cm2 (p < 0.05). The mono and dual-species biofilms were subjected to disinfection treatments; and the most effective disinfectant was peracetic acid (3500 ppm), reducing by more than 5 Log10 CFU/cm2, while the least effective was cetrimonium bromide. In addition, S. aureus 4E and Salmonella spp. were more resistant to the disinfectants in mono than in dual-species biofilms (p < 0.05). Therefore, the interspecies interactions between S. aureus 4E and Salmonella spp. had a negative effect on the antimicrobial resistance of each microorganism, compared with the monospecies biofilms.

A persistência intracelular de Escherichia coli enteroagregativa induz a secreção de citocinas pró-inflamatórias em células epiteliais intestinais T84 / Intracellular persistence of enteroaggregative escherichia coli induces a proinflammatory cytokines secretion in intestinal epithelial t84 cells

ABSTRACT BACKGROUND: The competence of enteroaggregative Escherichia coli (EAEC) to adhere to the intestinal epithelium of the host is a key role to the colonization and disease development. The virulence genes are crucial for EAEC pathogenicity during adherence, internalization and persistence in the host. The overwhelming majority of antigen encounters in a host occurs on the intestine surface, which is considered a part of innate mucosal immunity. Intestinal epithelial cells (IECs) can be activated by microorganisms and induce an immune response. OBJECTIVE: The present study investigated the interaction of invasive EAEC strains with T84 intestinal epithelial cell line in respect to bacterial invasiveness, persistence and cytokines production. METHODS: We evaluated intracellular persistence of invasive EAEC strains (H92/3, I49/3 and the prototype 042) and production of cytokines by sandwich ELISA in T84 cells upon 24 hours of infection. RESULTS: The survival rates of the prototype 042 was 0.5x103 CFU/mL while survival of I49/3 and H92/3 reached 3.2x103 CFU/mL and 1.4x103 CFU/mL, respectively. Infection with all EAEC strains tested induced significant amounts of IL-8, IL-6 and TNF-α compared to uninfected T84 cells. CONCLUSION: These data showed that infection by invasive EAEC induce a proinflammatory immune response in intestinal epithelial T84 cells.

RESUMO CONTEXTO: A competência de Escherichia coli enteroagregativa (EAEC) para aderir ao epitélio intestinal do hospedeiro é um papel fundamental para a colonização e o desenvolvimento da doença. Os genes de virulência são cruciais para a patogenicidade de EAEC durante a aderência, a internalização e a persistência no hospedeiro. A grande maioria dos encontros de antígenos em um hospedeiro ocorre na superfície do intestino, que é considerada parte da imunidade inata da mucosa. As células epiteliais intestinais (IECs) podem ser ativadas por micro-organismos e induzir uma resposta imune. OBJETIVO: O presente estudo investigou a interação de cepas invasoras de EAEC com a linhagem celular epitelial intestinal T84 em relação a invasão bacteriana, a persistência e a produção de citocinas. MÉTODOS: Avaliamos a persistência intracelular de cepas invasoras de EAEC (H92/3, I49/3 e o protótipo 042) e a produção de citocinas por ELISA "sanduíche" em células T84 após 24 horas de infecção. RESULTADOS: As taxas de sobrevivência da cepa protótipo 042 foi de 0,5x103 UFC/mL, enquanto a sobrevivência de I49/3 e H92/3 atingiu 3,2x103 UFC/mL e 1,4x103 UFC/mL, respectivamente. A infecção com todas as cepas EAEC testadas induziu quantidades significativas de IL-8, IL-6 e TNF-α em comparação com células T84 não infectadas. CONCLUSÃO: Estes dados mostraram que a infecção por EAEC invasoras induzem uma resposta imune pró-inflamatória em células epiteliais intestinais T84.

Evaluation antibacterial and antibiofilm activity of the antimicrobial peptide P34 against Staphylococcus aureus and Enterococcus faecalis

ABSTRACT The adhesion ability of bacteria to abiotic surfaces has important implications in food industries, because these organisms can survive for long periods through the biofilm formation. They can be transferred from one place to another in the industry causing contamination of the food processing environment. In this study, the antibacterial and antibiofilm activities of the antimicrobial peptide P34, characterized as a bacteriocin-like substance (BLS P34) were tested against planktonic and sessile cells of Staphylococcus aureus and Enterococcus faecalis isolated from foods. The BLS P34 showed inhibitory effect against all planktonic cells of E. faecalis. The inhibition of biofilm formation and the eradication of pre-formed biofilm were evaluated with the crystal violet assay and with the reduction of 3-bromide [4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium. The BLS P34 promoted a reduction of percentage of adhered microbial cells on the surface, not being able to perform the complete elimination of biofilm formation. The metabolic activity of S. aureus biofilms decreased considerably between 41-95%. However, E. faecalis cells showed up metabolically stimulated. The BLS P34 has the potential antibiofilm for the species S. aureus. Studies suggest more detailed approaches to a better understanding of the interactions between the antimicrobial and bacterial cells within the biofilm structure.