Demystifying interactions between micro organisms in oral candidiasis biofilm: the key to enhancing treatments

Introduction: candida albicans is a fungal pathogen that can provoke diseases ranging from oral infections to life-threatening systemic disorders. It is now recognized that oral bacteria, such as the genus Streptococcus, establish synergistic relationships with C. albicans, which could potentially increase the fungi's virulence and pathogenicity. Objective: this narrative review aimed to discuss the Candida-Streptococcus mechanisms of interactions and their contribution to increasing oral candidiasis severity. In addition, it provides a background of biofilm formation and potential therapeutical targets. Sources of Data: searches for papers in English were performed in the Pubmed database until May 2022. MeSH and free terms related to the field were used. In vitro studies were selected, tabulated, and qualitative and quantitative data were analyzed descriptively. Synthesis of Data: among the early colonizers bacteria, evidence pointed out that S. gordonnii and S. oralis have major implications in oral candidiasis, in which mixed biofilms increase the infection severity and challenge the host's defense. On the other hand, the outcomes of the interaction between C. albicans and S. mitis, S. sanguinis, or S. mutans remain little explored in the oral candidiasis scenario, albeit evidence pointed out an enhanced fungus population and virulence factors. Conclusion: overall, considering the polymicrobial profile of the infection and the potential to increase Candida-related disease severity, therapeutical strategies should also consider bacteria management.

Introdução: candida albicans é um patógeno fúngico que pode provocar doenças que variam de infecções orais a distúrbios sistêmicos com risco de vida. Hoje se reconhece que as bactérias orais, como o gênero Streptococcus, estabelecem relações sinérgicas com C. albicans, o que pode potencialmente aumentar a virulência e patogenicidade do fungo. Objetivo: esta revisão narrativa teve como objetivo discutir os mecanismos de interação Candida-Streptococcus e sua contribuição para o agravamento da candidíase oral. Além disso, fornece uma breve explanação sobre a formação do biofilme e potenciais alvos terapêuticos. Fonte dos dados: foi realizada pesquisa na base de dados Pubmed para a busca de artigos publicados em Inglês até maio de 2022. Para isso, foram utilizados descritores relacionados ao tema. Estudos in vitro foram selecionados, tabulados e seus resultados quantitativos e qualitativos analisados descritivamente. Síntese dos dados: entre as bactérias denominadas colonizadores iniciais, evidências apontam que S. gordonnii e S. oralis têm implicações importantes na candidíase oral, na qual biofilmes mistos aumentam a gravidade da infecção e desafiam a defesa do hospedeiro. Por outro lado, os desfechos das interações entre C. albicans e S. mitis, S. sanguinis ou S. mutans permanecem pouco explorados no cenário da candidíase oral, apesar de evidências apontarem um aumento dapopulação fúngica e de fatores de virulência. Conclusão: de maneira geral, considerando o perfil polimicrobiano da infecção e o potencial agravamento das doenças provocadas por Candida spp, as estratégias terapêuticas não devem estar focadas apenas no fungo, mas também devem considerar o manejo da bactéria.

Aplicação do plasma de baixa temperatura sob pressão atmosférica no controle de biofilmes cariogênicos / Application of low temperature plasma under atmospheric pressure in the control cariogenic biofilms

O objetivo geral do presente estudo foi avaliar a aplicação dos jatos de plasma de baixa temperatura sob pressão atmosférica (PBTPA) produzidos por gás de argônio e hélio como gases de trabalho, no controle de biofilmes cariogênicos. Para tanto, foram estabelecidos os parâmetros físicos dos PBTPA gerados com argônio e hélio que se mostraram efetivos frente a biofilmes mono, dual e polimicrobianos compostos por combinações das espécies Streptococcus mutans, Streptococcus gordonii, Streptococcus sanguinis, Lactobacillus casei, Lactobacillus acidophilus, Candida albicans e Actinomyces naeslundii. Os biofilmes mono, dual e multi-espécies foram submetidos ao tratamento com PBTPA produzidos por dois dispositivos diferentes, um obtido comercialmente (kINPen09®) que usou argônio como gás de trabalho, e outro protótipo desenvolvido pela FEG-UNESP (Faculdade de Engenharia de Guaratinguetá) que usou hélio. Análises quantitativas e microscópicas (confocal, microscopia eletrônica de varredura) foram realizadas. Foi incluído controle negativo (sem tratamento), positivo (clorexidina 0,12%) e controle de gás, utilizando apenas fluxo de gás, sem produzir plasma. Além disso, os efeitos celulares do PBTPAargônio e hélio sobre biofilme dual e multi-espécies também foram analisados em microscopia eletrônica de varredura e microscopia de varredura a laser confocal. Todos os ensaios foram realizados em triplicata em três experimentos independentes. Os resultados foram tabulados e analisados quanto à distribuição. A seguir, os testes estatísticos mais adequados foram selecionados. O nível de significância foi de 5%. Os resultados obtidos para os tratamentos dos biofilmes mono, dual ou multi-espécies com PBTPA-argônio e hélio foram todos significativos em comparação ao controle negativo em todos os tempos analisados. Para PBTPA-argônio, não houve recuperação de S. gordonii e S. sanguinis em todos tempos analisados. Para PBTPA-hélio, os melhores resultados foram obtidos em 5 e 7 minutos de exposição dos biofilmes ao PBTPA. Finalmente, tanto o dispositivo gerador de PBTPA que trabalhou com gás argônio quanto o dispositivo que trabalhou com gás hélio, demonstraram resultados promissores e poderão contribuir para o desenvolvimento de novos protocolos de Odontologia de Intervenção Mínima. (AU) The general objective of this study was to evaluate the application of lowtemperature plasma under atmospheric pressure (PBTPA) of argon and helium flow, in the control of cariogenic biofilms. For this, the effective physical parameters of PBTPA-argon and helium in mono, dual and polymicrobial biofilms composed of combinations of the species Streptococcus mutans, Streptococcus gordonii, Streptococcus sanguinis, Lactobacillus casei, Lactobacillus acidophilus, Candida albicans and Actinomyces naeslundii were established. The multi-species biofilms were treated by different PBTPA generating devices, one obtained commercially (kINPen09®) that used argon as working gas, and another prototype developed by FEG-UNESP (Faculdade de Engenharia de Guaratinguetá) that used helium as working gas. Quantitative and microscopic analyzes (confocal, scanning electron microscopy) were performed. Negative control (no treatment), positive control (chlorhexidine 2%) and gas control (argon) were included. Besides that, cellular effects of PBTPA-argon and helium on dual and multi-species biofilms were analyzed by scanning electron microscopy (SEM) and confocal laser scanning microscopy. The results obtained for the treatments of mono, dual or multispecies biofilms with both PBTPA-argon and helium were all significant when compared to the negative control at all times analyzed. For PBTPA-argon, there was no recovery of S. gordonii and S. sanguinis at all analyzed times. For PBTPA-helium, the best results were obtained at 5 and 7 min of exposure of biofilms to PBTPA. All the tests were carried out in triplicate in three independent experiments. The results are tabulated and analyzed in terms of distribution. Next, the most suitable statistical tests were selected. The level of significance was 5%. The results obtained for the treatments of mono, dual or multi-species biofilms with PBTPA-argon and helium were all significant compared to the negative control at all analyzed times. Finally, both PBTPA generating could contribute to the development of new protocols for Minimal Intervention Dentistry (AU)

O objetivo geral do presente estudo foi avaliar a aplicação dos jatos de plasma de baixa temperatura sob pressão atmosférica (PBTPA) produzidos por gás de argônio e hélio como gases de trabalho, no controle de biofilmes cariogênicos. Para tanto, foram estabelecidos os parâmetros físicos dos PBTPA gerados com argônio e hélio que se mostraram efetivos frente a biofilmes mono, dual e polimicrobianos compostos por combinações das espécies Streptococcus mutans, Streptococcus gordonii, Streptococcus sanguinis, Lactobacillus casei, Lactobacillus acidophilus, Candida albicans e Actinomyces naeslundii. Os biofilmes mono, dual e multi-espécies foram submetidos ao tratamento com PBTPA produzidos por dois dispositivos diferentes, um obtido comercialmente (kINPen09®) que usou argônio como gás de trabalho, e outro protótipo desenvolvido pela FEG-UNESP (Faculdade de Engenharia de Guaratinguetá) que usou hélio. Análises quantitativas e microscópicas (confocal, microscopia eletrônica de varredura) foram realizadas. Foi incluído controle negativo (sem tratamento), positivo (clorexidina 0,12%) e controle de gás, utilizando apenas fluxo de gás, sem produzir plasma. Além disso, os efeitos celulares do PBTPAargônio e hélio sobre biofilme dual e multi-espécies também foram analisados em microscopia eletrônica de varredura e microscopia de varredura a laser confocal. Todos os ensaios foram realizados em triplicata em três experimentos independentes. Os resultados foram tabulados e analisados quanto à distribuição. A seguir, os testes estatísticos mais adequados foram selecionados. O nível de significância foi de 5%. Os resultados obtidos para os tratamentos dos biofilmes mono, dual ou multi-espécies com PBTPA-argônio e hélio foram todos significativos em comparação ao controle negativo em todos os tempos analisados. Para PBTPA-argônio, não houve recuperação de S. gordonii e S. sanguinis em todos tempos analisados. Para PBTPA-hélio, os melhores resultados foram obtidos em 5 e 7 minutos de exposição dos biofilmes ao PBTPA. Finalmente, tanto o dispositivo gerador de PBTPA que trabalhou com gás argônio quanto o dispositivo que trabalhou com gás hélio, demonstraram resultados promissores e poderão contribuir para o desenvolvimento de novos protocolos de Odontologia de Intervenção Mínima. (AU)

Antibacterial Activity of Homeopathic Medications Lycopodium clavatum and Arsenicum album Against Periodontal Bacteria / Evaluación antibacteriana de los medicamentos homeopáticos sobre bacterias periodontales

Abstract There are several controversies regarding the efficacy of homeopathic substances; however, these remedies are used in many countries for the treatment of various pathological conditions. The purpose of this study was to evaluate the in vitro antibacterial activity of two homeopathic tinctures Arsenicum album (mineral extract) and Lycopodium clavatum (plant extract) on the periodontal bacteria Actinomyces israelii, Streptococcus sanguinis, Prevotella intermedia, Aggregatibacter actinomycetemcomitans and Phorphyromonas gingivalis (P. gingivalis). Materials and methods: Equal numbers of bacteria were seeded on agar plates containing enriched media with the homeopathic solutions at 1dH and 1cH dilutions. After 7 days of incubation under anaerobic conditions, colony forming units (CFUs) were counted. The antibacterial effect was calculated based on the total number of CFUs observed on non-tincture containing agar, and on the tincture containing plates. Results: No visible growth of any of the strains was observed on the plates containing Arsenicum album at any of the dilutions tested. In contrast, when Lycopodium clavatum at 1cH dilution was tested, only P. gingivalis was susceptible to this compound. Conclusions: The results suggest that the mineral extract tincture had a greater antibacterial activity than the plant extract tincture, also Lycopodium clavatum preparation could be an effective inhibitor of periodontal pathogens bacteria such as P. gingivalis.

Resumen Se necesita un mayor número de estudios in vitro e in vivo para validar estos resultados.

Influence of Helicobacter pylori culture supernatant on the ecological balance of a dual-species oral biofilm

Abstract Dental caries is a chronic progressive disease occurring in the tooth hard tissue due to multiple factors, in which bacteria are the initial cause. Both Streptococcus mutans and Streptococcus sanguinis are main members of oral biofilm. Helicobacter pylori may also be detected in dental plaque, playing an important role in the development of dental caries. Objective The aim of this study was to investigate the effect of H. pylori culture supernatant on S. mutans and S. sanguinis dual-species biofilm and to evaluate its potential ability on affecting dental health. Material and methods The effect of H. pylori supernatant on single-species and dual-species biofilm was measured by colony forming units counting and fluorescence in situ hybridization (FISH) assay, respectively. The effect of H. pylori supernatant on S. mutans and S. sanguinis extracellular polysaccharides (EPS) production was measured by both confocal laser scanning microscopy observation and anthrone-sulfuric acid method. The effect of H. pylori supernatant on S. mutans gene expression was measured by quantitative real-time PCR (qRT-PCR) assays. Results H. pylori supernatant could inhibit both S. mutans and S. sanguinis biofilm formation and EPS production. S. sanguinis inhibition rate was significantly higher than that of S. mutans. Finally, S. mutans bacteriocin and acidogenicity related genes expression were affected by H. pylori culture supernatant. Conclusion Our results showed that H. pylori could destroy the balance between S. mutans and S. sanguinis in oral biofilm, creating an advantageous environment for S. mutans, which became the dominant bacteria, promoting the formation and development of dental caries.

Effect of TiO2 nanoparticles incorporation on antibacterial properties and shear bond strength of dental composite used in Orthodontics

ABSTRACT Introduction: Plaque accumulation and bond failure are drawbacks of orthodontic treatment, which requires composite for bonding of brackets. As the antimicrobial properties of TiO2 nanoparticles (NPs) have been proven, the aim of this study was to evaluate the antimicrobial and mechanical properties of composite resins modified by the addition of TiO2 NPs. Methods: Orthodontics composite containing 0%, 1%, 5% and 10% NPs were prepared. 180 composite disks were prepared for elution test, disk agar diffusion test and biofilm inhibition test to collect the counts of microorganisms on three days, measure the inhibition diameter and quantify the viable counts of colonies consequently. For shear bond strength (SBS) test, 48 intact bovine incisors were divided into four groups. Composites containing 0%, 1%, 5% and 10% NPs were used for bonding of bracket. The bracket/tooth SBS was measured by using an universal testing machine. Results: All concentration of TiO2 NPs had a significant effect on creation and extension of inhibition zone. For S. mutans and S. sanguinis, all concentration of TiO2 NPs caused reduction of the colony counts. Composite containing 10% TiO2 NPs had significant effect on reduction of colony counts for S. mutans and S. sanguinis in all three days. The highest mean shear bond strength belonged to the control group, while the lowest value was seen in 10% NPs composite. Conclusions: Incorporating TiO2 nanoparticles into composite resins confer antibacterial properties to adhesives, while the mean shear bond of composite containing 1% and 5% NPs still in an acceptable range.

RESUMO Introdução: o acúmulo de placa e as descolagens de braquetes são algumas desvantagens presentes no tratamento ortodôntico, no qual se requer o uso de materiais compósitos para a colagem dos braquetes. Objetivo: tendo em vista que as propriedades antimicrobianas das nanopartículas (NPs) de TiO2 já foram confirmadas, o objetivo do presente estudo foi avaliar as propriedades antimicrobianas e mecânicas de resinas compostas modificadas pela adição de NPs de TiO2. Métodos: compósitos ortodônticos contendo 0%, 1%, 5% e 10% de NPs foram preparados. Cento e oitenta discos de compósito foram preparados para o teste de eluição, o ensaio de difusão em ágar por disco, e o ensaio de inibição da formação de biofilme, para se calcular as contagens de microrganismos ao longo de três dias, medir o diâmetro da inibição e, consequentemente, quantificar as contagens de colônias viáveis. Para o teste de resistência da colagem ao cisalhamento (SBS), 48 incisivos bovinos intactos foram divididos em quatro grupos, nos quais os compósitos contendo 0%, 1%, 5% e 10% de NPs foram utilizados para colagem dos braquetes. A SBS da interface braquete/dente foi medida em uma máquina universal de ensaios. Resultados: todas as concentrações de NPs de TiO2 apresentaram efeito significativo na formação e na extensão da zona de inibição. Para o S. mutans e o S. sanguinis, todas as concentrações de NPs de TiO2 causaram redução na contagem das colônias. O compósito contendo 10% de NPs de TiO2 apresentou uma diminuição significativa na contagem de colônias de S. mutans e S. sanguinis durante os três dias. A média mais alta da SBS foi observada no grupo controle, enquanto o valor mais baixo foi observado para o compósito com 10% de NPs. Conclusões: a incorporação de nanopartículas de TiO2 nas resinas compostas lhes conferiu propriedades antibacterianas, e o valor médio da SBS das resinas contendo 1% e 5% de NPs apresentou-se dentro de uma faixa aceitável.

Incorporation of disinfectants for obtaining dental stone: microbiological and dimensional evaluation / Incorporação de desinfetantes para obtenção de modelos de gesso: avaliação microbiológica e dimensional

Aim: To assess dimensional change and antimicrobial activity of disinfectants substances incorporated during the dental stone manipulation. Material and Method: In vivo - microorganisms were collected in alginate molds of 30 volunteers inoculated on BHI agar and incubated at 37 °C for 24 hours. The molds were cast with type IV gypsum, manipulated with saline (G1), 1% sodium hypochlorite (G2) and 4% chlorhexidine (G3), replacing the water. After setting of plaster with 1 hour two collections on models were made. After 24 hours, the readings were performed. The Kruskal-Wallis and Wilcoxon tests with confidence interval of 99% and 95% respectively were used. In vitro - Müeller Hinton agar petri dishes were inoculated with S. mutans (ATCC25175), S. sanguis (ATCC10556) and E. faecalis (ATCC29212), over which were placed steel rings filled with the same substances of the in vivo study. After deposition of gypsum and incubation, halos were measured with a digital caliper and data were submitted to ANOVA and Tukey's test with confidence interval of 95%. Dimensional Change - With a metallic matrix and a perfectly adapted tray, the insertion axis and force used for moulding and obtain 30 specimens in type IV gypsum were standardized, following the same distribution of the study groups in vivo. The specimens were measured by Image Pro Plus software and data were submitted to ANOVA and Tukey's test with confidence interval of 95%. Result: Data from the in vivo study demonstrated a significant difference between the mold and each model (p<0.001). In the Wilcoxon test there was no significant difference between groups of models. At the in vitro test, G2 showed greater inhibition zones in all micro-organisms tested compared to G3, but with respect to dimensional changes, there was a significant difference between solutions and metallic standard, where G3 caused less change than G2. Conclusion: Chlorhexidine 4% showed to be the most suitable disinfectant. .

Objetivo: Avaliar alteração dimensional e ação antimicrobiana de substâncias desinfetantes incorporadas durante manipulação do gesso. Material e Método: In vivo - Micro-organismos foram coletados com swabs dos moldes de 30 voluntários, inoculados em Ágar BHI e incubados a 37 °C por 24 horas. Os moldes foram vazados com gesso tipo IV, manipulados com soro fisiológico (G1), hipoclorito de sódio 1% (G2) e clorexidina 4% (G3) substituindo a água. Decorrida 1 hora de presa fez-se duas coletas com swabs nos modelos, incubação e leituras das placas após 24 horas. Empregaram-se os testes Kruskal-Wallis e Wilcoxon com níveis de confiança de 99% e 95% respectivamente. In vitro - Inocularam-se S. mutans (ATCC25175), S. sanguis (ATCC10556) e E. faecalis (ATCC29212) em Ágar Müeller Hinton, onde posicionaram-se anéis de aço preenchidos com as mesmas substâncias do estudo in vivo. Após deposição do gesso e incubação, os halos foram medidos com paquímetro digital e os dados submetidos à ANOVA e Tukey com nível de confiança de 95%. Alteração dimensional - Com matriz metálica e moldeira perfeitamente adaptada padronizou-se eixo de inserção e força empregada para moldagem e obtenção de 30 corpos de prova em gesso tipo IV, seguindo a mesma distribuição dos grupos do estudo in vivo. Os corpos de prova foram mensurados pelo software Image Pro Plus e os dados submetidos à ANOVA e Tukey com nível de confiança de 95%. Resultado: Os dados do estudo in vivo demonstraram diferença significativa entre molde e cada modelo (p<0,001). No teste Wilcoxon não houve diferença significante entre grupos de modelos. In vitro- G2 apresentou maiores halos de inibição em todos micro-organismos testados em relação ao G3, mas com relação à alteração dimensional, houve diferença significante entre soluções e padrão metálico, onde G3 provocou menor alteração do que G2. Conclusão: Clorexidina 4% apresentou-se como o desinfetante mais adequado. .

Effects of Yili dark bee propolis on oral cariogenic biofilm in vitro / 华西口腔医学杂志

<p><b>OBJECTIVE</b>To evaluate the effects of Yili dark bee propolis on the main cariogenic biofilm and mechanisms.</p><p><b>METHODS</b>Susceptibilities to the ethanolic extract of propolis against Streptococcus mutans (S. mutans), Streptococcus sobrinus (S. sobrinus), Streptococcus sanguis (S. sanguis), Actinomyces viscosus (A. viscosus), and Actinomyces naeslundii (A. naeslundii) were analyzed by crystal violet stain method to determine the minimum biofilm eradication concentration (MBEC). The biofilm was initially cultivated for 24 h. Subsequently, the propolis groups with different concentration MBEC and initial pH 7.0 were cultured for 24 h. Moreover, the pH value was measured to evaluate the acid-producing ability of the tested plaque biofilm. The effects of propolis on the insoluble extracellular polysaccharide synthesis of S. mutans biofilm were evaluated by anthrone method.</p><p><b>RESULTS</b>The MBEC of Yili propolis on S. mutans, S. sobrinus, S. sanguis, A. viscosus, and A. naeslundii were 6.25, 1.56, 3.13, 0.78, and 0.78 mg.mL-1, respectively. Propolis could decrease the ΔpH of the tested plaque biofilm, and the differences between the control and propolis groups were statistically significant (P<0.05). At MBEC, propolis could reduce the ability of S. mutans in synthesizing insoluble extracellular polysaccharides.</p><p><b>CONCLUSION</b>Yili propolis demonstrate remarkable eradicative effects on the cariogenic plaque biofilm, showing inhibition of the synthesis of biofilm-produced acids and insoluble extracellular polysaccharides.</p>

Influence of time, toothpaste and saliva in the retention of Streptococcus mutans and Streptococcus sanguinis on different toothbrushes

Objectives: The intraoral transmission of cariogenic and periodontopathogenic species seems to be facilitated by contaminated toothbrushes and other oral hygiene devices. The aim of this investigation was to analyze the in vitro retention and survival rate of Streptococcus mutans and Streptococcus sanguinis on different toothbrushes. The impacts of human saliva and antimicrobial toothpaste on these parameters were further evaluated. Material and Methods: Part I: Four toothbrushes (Colgate 360°, Curaprox CS5460 ultra soft, elmex InterX, Trisa Flexible Head3) were contaminated by S. mutans DSM 20523 or S. sanguinis DSM 20068 suspensions for three minutes. Bacteria were removed from the toothbrushes after either three minutes (T0) or 24 hours (T24) of dry storage and grown on Columbia blood agar plates for the quantification of colony-forming units (CFUs). Part II: The effects of saliva from a caries-active or a caries-inactive person and of toothpaste containing 0.12% chlorhexidine digluconate were also tested. Results: Part I: After three minutes of dry storage, approximately one percent of the bacteria were still detectable on the toothbrushes. After 24 hours, S. sanguinis exhibited a more pronounced decrease in viable cell numbers compared with S. mutans but the differences were not significant (Kruskal-Wallis test, p>0.05). Part II: The addition of human saliva from a caries-active or caries-inactive person slightly increased the retention of both streptococcal species at T0. The use of toothpaste had no influence on the amount of viable streptococci at T0, but it reduced the microbial load after 24 hours of storage. There were only slight nonsignificant differences (p>0.05) between the four toothbrushes. Conclusions: In vitro bacterial retention and survival of S. sanguinis and S. mutans on different toothbrushes occurred. Within the limitations of this study, the use of human saliva or an antimicrobial toothpaste ...

Cuantificación de bacterias relacionadas con la caries dental en saliva de adultos y adultos mayores / Quantification of caries-associated bacteria from saliva of adults and older adults

Introducción: Se considera que Streptococcus mutans (S. mutans) y Lactobacillus spp. se asocian con la caries. Otras especies del biofilm oral, como Streptococcus sanguinis (S. sanguinis) han sido sindicadas como protectoras, pero principalmente en niños. Existe escasa evidencia sobre el nivel de estas bacterias en adultos mayores. Objetivo: Determinar si existen diferencias en los recuentos microbianos de tres especies relacionadas con la caries en pacientes adultos y adultos mayores. Materiales y Métodos: Una muestra de pacientes por conveniencia compuesta de 63 pacientes (18 a 79 años) proporcionó saliva estimulada con la que se sembraron placas de agar MSB, MM10 SB y Agar Rogosa para el cultivo de S. mutans, S. sanguinis y Lactobacillus spp., respectivamente. Los recuentos bacterianos fueron expresados como UFC/mL. Resultados: Los recuentos de S. mutans y Lactobacillus spp. no mostraron variaciones relacionadas con la edad (p>0.05). Los adultos mostraron mayores recuentos de S. sanguinis que los adultos mayores, 3.7 x 105 +/- 3.8 x 105 UFC/mL y 5.9 x 104 +/- 9.4 x 104 UFC/mL, respectivamente (p<0.05). Conclusiones: La edad no parece afectar los niveles de especies tradicionalmente consideradas como cariogénicas. Estos resultados sugieren que la edad puede relacionarse con los patrones de colonización de S. sanguinis en el biofilm oral.

Introduction: Streptococcus mutans (S. mutans) and Lactobacillus spp. have been traditionally associated with caries, regardless of the subject’s age. Other oral biofilm species have been linked as caries protective, including Streptococcus sanguinis (S. sanguinis), but mainly in children. Scarce evidence exists on the levels of these bacteria in older adults. Aim: To determine whether there are differences in the microbial counts of three caries-associated bacterial species in adults and older adults. Methodology: A convenience sample of sixty three patients, aged 18 to 79 years, participated in the study. Stimulated saliva samples were obtained and in MSB, MM10 and Rogosa agar plates for the culture of S. mutans, S. sanguinis and Lactobacillus spp., respectively. Bacterial counts were obtained by microscopic observation (10x) of the colonies and expressed in CFU/mL. Results: Bacterial counts of S. mutans and Lactobacillus spp. did not reveal age-related differences (p>0.05). Adults showed higher S. sanguinis counts than older adults with 3.7 x 105 +/- 3.8 x 105 CFU/mL and 5.9 x 104 +/- 9.4 x 104 CFU/mL, respectively (p<0.05). Conclusions: Age does not seem to affect the levels of bacterial species traditionally associated with caries. The results suggest that age may be related to colonization patterns of S. sanguinis in the oral biofilm.

Protein structure prediction of the lactate dehydrogenase of Streptococcus oligofermentans / 中华口腔医学杂志

<p><b>OBJECTIVE</b>To compare the gene sequence and protein structure of lactate dehydrogenase (LDH) in Streptococcus oligofermentans with those of other bacteria with different acid generating capacities in oral cavity and to analyze the differences of their LDH.</p><p><b>METHODS</b>LDH gene sequence of Streptococcus oligofermentans was measured by Institute of Microbiology, Chinese Academy of Sciences. LDH gene sequences of four Streptococcus and Lactobacillus casei in the NCBI Genbank was identified and compared among the six bacteria's LDH gene sequences and amino acid sequences by BLAST software. ExPASy database was used to predict the physical-chemical characteristics, secondary structure, trans-membrane regions, and spatial structure of Streptococcus oligofermentans LDH protein, which was compared with those of other bacteria.</p><p><b>RESULTS</b>The full-length of the LDH gene sequences of Streptococcus oligofermentans was 987 base pairs. The highest similarity was 89% with that of the Streptococcus sanguis, and 81% similarity with Streptococcus mutans, and 70% similarity with Lactobacillus casei. LDH amino acid sequence of Streptococcus oligofermentans was similar to Streptococcus sanguinis, with the highest similitude of 96%, with a similitude of 81% to Streptococcus mutans, but differed greatly from that of Lactobacillus casei, with a similitude of only 66%. Streptococcus oligofermentans LDH protein's physical-chemical characteristics, trans-membrane region's numbers, proportions of secondary structure, structural domain's location resembled those of Streptococcus mutans, Streptococcus sanguinis and Lactobacillus casei. Spatial structure differences between the LDH of Streptococcus oligofermentans and that of Streptococcus mutans and Lactobacillus casei were distinct.</p><p><b>CONCLUSIONS</b>Streptococcus oligofermentans LDH's gene sequence, amino acid sequence, and spatial structure all vary from those of Streptococcus mutans and Lactobacillus casei, and these differeces may be a inherent reason that lead to the changes of its LDH's biological functions and incapacity of producing lactic acid.</p>

In vitro antagonistic growth effects of Lactobacillus fermentum and Lactobacillus salivarius and their fermentative broth on periodontal pathogens

As lactobacilli possess an antagonistic growth property, these bacteria may be beneficial as bioprotective agents for infection control. However, whether the antagonistic growth effects are attributed to the lactobacilli themselves or their fermentative broth remains unclear. The antagonistic growth effects of Lactobacillus salivarius and Lactobacillus fermentum as well as their fermentative broth were thus tested using both disc agar diffusion test and broth dilution method, and their effects on periodontal pathogens, including Streptococcus mutans, Streptococcus sanguis, and Porphyromonas gingivalisin vitro at different concentrations and for different time periods were also compared. Both Lactobacillus salivarius and Lactobacillus fermentum and their concentrated fermentative broth were shown to inhibit significantly the growth of Streptococcus mutans, Streptococcus sanguis, and Porphyromonas gingivalis, althoughdifferent inhibitory effects were observed for different pathogens. The higher the counts of lactobacilli and the higher the folds of concentrated fermentative broth, the stronger the inhibitory effects are observed. The inhibitory effect is demonstrated to be dose-dependent. Moreover, for the lactobacilli themselves, Lactobacillus fermentum showed stronger inhibitory effects than Lactobacillus salivarius. However, the fermentative broth of Lactobacillus fermentum showed weaker inhibitory effects than that of Lactobacillus salivarius. These data suggested that lactobacilli and their fermentative broth exhibit antagonistic growth activity, and consumption of probiotics or their broth containing lactobacilli may benefit oral health.

Septic Knee Arthritis Caused by Streptococcus sanguis in a Patient with Osteoarthritis of the Knee / 대한정형외과학회잡지

Streptococcus sanguis (S. sanguis) is a gram positive streptococcus bacteria which is found in the normal bacterial flora of the oral cavity and the upper respiratory tract. It has low virulence, but it can cause bacterial endocarditis through the blood circulation when dental calculus are removed from the teeth or during surgical treatment. Septic arthritis caused by S. sanguis has been reported as infecting the sternoclavicular joint and the knee joint, but it is a quite rare infectious disease that has not been reported in Korea. Therefore, the authors report a case of the septic arthritis in the knee joint caused by S. sanguis in a patient with osteoarthritis of the knee, who has the history of periodontitis.

Lung Abscess and Bacteremia Caused by Neisseria flavescens and Streptococcus sanguis in Patient with Idiopathic Hypereosinophilic Syndrome / 대한임상미생물학회지

Neisseria flavescens has been rarely reported as a pathogen in the literature. We experienced a case of N. flavescens bacteremia and lung abscess co-infected with Streptococcus sanguis in patient with idiopathic hypereosinophilic syndrome. A 15-year-old boy was diagnosed with idiopathic hypereosinophilic syndrome complicated with pulmonary thromboembolism. He was given systemic steroids and thrombolytics. After 8 weeks of therapy, a lung abscess appeared on the plain chest radiograph. We treated him with empirical antibiotics and carried out surgical drainage. Two types of microorganisms were cultured from both blood and pus samples, obtained in the first day of hospitalization. Pus was aspirated from the lung abscess with an aseptic technique. Neisseria species and S. sanguis were identified using traditional methods. To confirm the identity of the Neisseria species, we conducted further testing using 16S ribosomal ribonucleic acid sequencing whereupon N. flavescens was identified. This is the first case report of pulmonary infection caused by N. flavescens. We suggest that N. flavescens may act as a pathogen.

Oxygen dependent pyruvate oxidase expression and production in Streptococcus sanguinis / 国际口腔科学杂志·英文版

The objective of this study was to characterize the oxygen dependent regulation of pyruvate oxidase (SpxB) gene expression and protein production in Streptococcus sanguinis (S. sanguinis). SpxB is responsible for the generation of growth-inhibiting amounts of hydrogen peroxide (H2O2) able to antagonize cariogenic Streptococcus mutans (S. mutans). Furthermore, the ecological consequence of H2O2 production was investigated in its self-inhibiting ability towards the producing strain. Expression of spxB was determined with quantitative Real-Time RT-PCR and a fluorescent expression reporter strain. Protein abundance was investigated with FLAG epitope engineered in frame on the C-terminal end of SpxB. Self inhibition was tested with an antagonism plate assay. The expression and protein abundance decreased in cells grown under anaerobic conditions. S. sanguinis was resistant against its own produced H2O2, while cariogenic S. mutans was inhibited in its growth. The results suggest that S. sanguinis produces H2O2 as antimicrobial substance to inhibit susceptible niche competing species like S. mutans during initial biofilm formation, when oxygen availability allows for spxB expression and Spx production.

In Vitro Effect of photodynamic therapy on Aggregatibacter actinomycetemcomitans and Streptococcus sanguinis

New periodontal disease treatments are needed to prevent infection progression. Photodynamic therapy (PDT) is one of the greatest pledges for this purpose. It involves the use of light of specific wavelength to activate a nontoxic photosensitizing agent in the presence of oxygen for eradication of target cells, and can be used for photokilling of microorganisms. This study evaluated in vitro the photodynamic effect of 0.01 percent toluidine blue-O (TBO) in combination with an AlGaInP diode laser light source on Aggregatibacter actinomycetemcomitans (A.a.) and Streptococcus sanguinis (S.s.). Suspensions (2 mL) containing A.a. and S.s. at 1.5 x 108 CFU/mL concentration were prepared and divided into 3 groups: Control group (no treatment), Dye group (inoculum and TBO for 5 min) and Dye/Laser group (inoculum, TBO for 5 min and laser for 3 min). Next, a dilution for subsequent subculture in 20 mL of Trypic Soy Agar (A.a) and Brucella Agar (S.s.) in Petri dishes (Pourplate Method) was done. Incubation of A.a. in microaerophilia and S.s. in aerobiosis at 35oC for 48 h was performed for subsequent visual counting of CFU/mL. Data were analyzed by one-way ANOVA and Tukey’s HSD test at 5 percent significance level. For both strains, the control group showed a significantly higher (p<0.05) bacterial growth (1.5 x 108 CFU/mL), while the Dye group presented no significant reduction (p>0.05) in the CFU counts. The Dye/Laser group presented a significant decrease in the CFU counts (p<0.05) compared with the Control group (61.53 percent for A.a. and 84.32 percent for S.s.). It may be concluded that PDT was effective in reducing the numbers of A.a. and S.s. in vitro.

Novos tratamentos são propostos para evitar a progressão da periodontite, sendo a terapia fotodinâmica (PDT) uma notória promessa. Sua aplicação associa o Azul de orto-toluidina a 0,01 por cento (TBO) e uma fonte luminosa a laser de diodo (TwinFlex, Mmoptics), liberando assim, toxinas às bactérias. O objetivo do estudo é avaliar in vitro a eficiência da PDT sobre Aggregatibacter actinomycetemcomitans (A.a.) e Streptococcus sanguinis (S.s.). Preparou-se suspensões distintas de 2 mL contendo A.a. e S.s. na concentração de 1,5x108 UFC/mL, e divisão de cada suspensão em 3 grupos: Controle (sem tratamento); Corante (suspensão e TBO por 5min) e Corante/Laser (suspensão, TBO por 5 min e laser por 3 min). Promoveu-se a diluição, a semeadura em 20 mL de TSA (A.a.) e de Ágar Brucella (S.s.), em placas de Petri (Método Pourplate), e a incubação da A.a. em microaerofilia e da S.s. em aerobiose, por 48 h a 35oC, para posterior contagem visual das UFC. Os grupos Controle mostraram ótimo crescimento bacteriano (1,5 x 108 UFC/mL). Os grupos Corante não apresentaram redução significativa para ambas bactérias. Os grupos Laser apresentaram redução em relação ao controle, 61,53 por cento para A.a. e 84,32 por cento para S.s. A análise estatística (ANOVA, p<0,05) corrobou que a PDT é eficaz na redução destas bactérias in vitro.

Initial bacterial adhesion on resin, titanium and zirconia in vitro

PURPOSE: The aim of this in vitro study was to investigate the adhesion of initial colonizer, Streptococcus sanguis, on resin, titanium and zirconia under the same surface polishing condition. MATERIALS AND METHODS: Specimens were prepared from Z-250, cp-Ti and 3Y-TZP and polished with 1 microm diamond paste. After coating with saliva, each specimen was incubated with Streptococcus sanguis. Scanning electron microscope, crystal violet staining and measurement of fluorescence intensity resulting from resazurin reduction were performed for quantifying the bacterial adhesion. RESULTS: Surface of resin composite was significantly rougher than that of titanium and zirconia, although all tested specimens are classified as smooth. The resin specimens showed lower value of contact angle compared with titanium and zirconia specimens, and had hydrophilic surfaces. The result of scanning electron microscopy demonstrated that bound bacteria were more abundant on resin in comparison with titanium and zirconia. When total biofilm mass determined by crystal violet, absorbance value of resin was significantly higher than that of titanium or zirconia. The result of relative fluorescence intensities also demonstrated that the highest fluorescence intensity was found on the surface of resin. Absorbance value and fluorescence intensity on titanium was not significantly different from those on zirconia. CONCLUSION: Resin specimens showed the roughest surface and have a significantly higher susceptibility to adhere Streptococcus sanguis than titanium and zirconia when surfaces of each specimen were polished under same condition. There was no significant difference in bacteria adhesion between titanium and zirconia in vitro.

The antagonistic effect of the oral Streptococcus on the Saccharomyces albicans in vitro / 华西口腔医学杂志

<p><b>OBJECTIVE</b>To investigate the antagonistic effects of three species of oral Streptococcus on the growth of oral Saccharomyces albicans in vitro.</p><p><b>METHODS</b>Direct inoculation method, reverse inoculation method and mixed culture methods were respectively chosen to observe the changes of Saccharomyces albicans colony formation on the effects of Streptococcus mutans, Streptococcus sanguis and Streptococcus salivarius.</p><p><b>RESULTS</b>1) No clear inhibition zone was observed in each of the groups by direct inoculation method. 2) Compared with the control groups, Saccharomyces albicans colony formation on soft agar of Streptococcus sanguis decreased significantly (P < 0.05). 3) Mixed culture method results showed that Streptococcus mutans could inhibit the growth of Saccharomyces albicans significantly at different time points (P = 0.001). 4) Under the action of bacteria culture supernatant, the count of Saccharomyces albicans in experiment groups showed statistical significance when compared with the control groups at 24, 48, 72 h (P = 0.001); The differences among the experimental groups were of no statistical significance at majority times (P > 0.05).</p><p><b>CONCLUSION</b>Streptococcus mutans, Streptococcus sanguis, and Streptococcus salivarius could obviously inhibit the growth of Saccharomyces albicans in vitro. However, it is still unclear that among which the inhibition effects is stronger. The antagonistic effects is weakened gradually.</p>

Aderência de microrganismos em implantes dentários de superfície lisa ou tratada / Adhesion of microorganisms in dental implants with a smooth surface or treated

O objetivo desse trabalho foi analisar in vitro a aderência de Streptococcus sanguinis às superfícies dos implantes dentários tratados com jateamento de fosfato de cálcio, anodização, duplo ataque ácido e os de superfície lisa. Foram selecionados 40 implantes, sendo 10 de cada superfície. Para análise da aderência, foram preparadas suspensões do microrganismo contendo 106 células/ml em espectrofotômetro. O implante foi removido da embalagem e colocado diretamente no caldo. Em seguida, foram acondicionados separadamente em poços de placas de cultura de células contendo caldo sacarosado (placa in vitro) e a suspensão do microrganismo. Após 24h de incubação a 37 ºC e 5 por cento de CO2, os implantes foram lavados três vezes durante um minuto em solução salina estéril e colocados em sonicador com 10 ml de salina para dispersão das células aderidas. A seguir, foram realizadas diluições seriadas e semeaduras em meios de cultura específico para cada microrganismo. Após 48h de incubação a 37 ºC e 5 por cento de CO2, foi realizada a contagem de unidades formadoras de colônias (UFC/ml) e os dados foram submetidos à análise de variância (ANOVA), teste de Tukey, com nível de significância de 5 por cento. Os resultados demonstraram uma grande aderência dos microrganismos às superfícies estudadas. A superfície anodizada apresentou os menores valores de aderência dos dois microrganismos, já a superfície submetida ao duplo ataque ácido apresentou maiores valores de UFC/ml.

The aim of this study was to analyze in vitro the adherence of Streptococcus sanguinis to dental implant surfaces treated with calcium phosphate blasting, anodizing, double acid etching and smooth surface. We selected 40 implants, 10 in each area. For analysis of adhesion of microorganism suspensions were prepared containing 106 cells/ml in a spectrophotometer. The implant was removed from its packaging and placed directly in the broth. Then were placed separately in of culture plates of cells containing broth containing sucrose (plate in vitro) and suspension of the microorganism. After 24h incubation at 37 oC and 5 percent CO2, the implants were washed three times for one minute in sterile saline and placed in a sonicator with 10 ml of saline for dispersion of the adhered cells. Next, serial dilutions were performed sowing and in culture media specific for each microorganism. After 48 h incubation at 37 oC and 5 percent CO2, were the count of colony forming units (CFU/ml) and the data were subjected to analysis of variance (ANOVA), Tukey test, with significance level 5 percent. The results showed a high adherence of microorganisms to surfaces studied. The anodized surface had the lowest values of adherence of two microorganisms, since the surface subjected to the double acid etching presented higher values of CFU/ml.

Implantes de torque interno TRYON® / TRYON® internal torque dental implant

Este trabalho apresenta os resultados de testes de validação de projeto da linha de implantes TRYON®. Nele são descritas as características principais do sistema: suas diferenças com relação ao sistema convencional e informações relativas ao conceito do produto. É apresentado o método de elementos finitos como ferramenta de validação de projeto, juntamente com ensaios experimentais. A superfície dos implantes é caracterizada através de microscopia eletrônica e a resistência mecânica do implante avaliada. Conclui-se que o sistema TRYON® apresenta simplicidade de uso e custo menor. O método de elementos finitos confere maior confi abilidade ao projeto do produto. A superfície TRYON® atende todos os requisitos de qualidade quanto à limpeza e rugosidade superficial. A resistência do implante ao carregamento inclinado (oblíquo) atende aos padrões normativos.

This paper presents the results of design validation testing of the TRYON® implant line. In it are described the main features of the system: its differences with the conventional system and information concerning the product concept. We present the finite element method as a tool for design validation, together with experimental tests. The surface of implants is characterized by electron microscopy and mechanical strength of the implant was evaluated. It is concluded that the TRYON® system presents simplicity of use and lower cost. The finite element method gives greater reliability to the product design. The TRYON® surface meets all quality requirements for cleanliness and surface roughness. The implant resistance of oblique loading meets the normative standards.

Modeling of diffusion transport through oral biofilms with the inverse problem method / 国际口腔科学杂志·英文版

<p><b>AIM</b>The purpose of this study was to develop a mathematical model to quantitatively describe the passive transport of macromolecules within dental biofilms.</p><p><b>METHODOLOGY</b>Fluorescently labeled dextrans with different molecular mass (3 kD, 10 kD, 40 kD, 70 kD, 2000 kD) were used as a series of diffusion probes. Streptococcus mutans, Streptococcus sanguinis, Actinomyces naeslundii and Fusobacterium nucleatum were used as inocula for biofilm formation. The diffusion processes of different probes through the in vitro biofilm were recorded with a confocal laser microscope.</p><p><b>RESULTS</b>Mathematical function of biofilm penetration was constructed on the basis of the inverse problem method. Based on this function, not only the relationship between average concentration of steady-state and molecule weights can be analyzed, but also that between penetrative time and molecule weights.</p><p><b>CONCLUSION</b>This can be used to predict the effective concentration and the penetrative time of anti-biofilm medicines that can diffuse through oral biofilm. Furthermore, an improved model for large molecule is proposed by considering the exchange time at the upper boundary of the dental biofilm.</p>