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.

Chemical Composition, Antibacterial and Antifungal Potential of an Extract From the Leaves of Guapira Graciliflora Mart. Against Oral Microorganisms of Dental Interest

Abstract Objective: To perform an in vitro analysis of antibacterial and antifungal potential of an alcoholic extract from the leaves of Guapira Graciliflora Mart. against oral microorganisms and determine its chemical composition. Material and Methods: A hydroalcoholic extract of the leaves form G. graciliflora was obtained through maceration, vacuum concentration and freeze-drying. Antibacterial and antifungal activities were evaluated against Streptococcus mutans, Streptococcus salivarius, Streptococcus oralis, Streptococcus parasanguinis, Streptococcus mitis and strains of Candida albicans using broth microdilution method. Phytochemical analysis determined the total phenolic compounds, protein concentration and total of sugars present in the extract. Results: G. Graciliflora demonstrated antifungal activity against the LM 11 and LM 410 clinical isolates of C. albicans (MIC 0.5 mg/mL and 2 mg/mL, respectively). The other microorganisms tested were resistant to the extract. The phytochemical analysis revealed 3% proteins, 13% total sugars and 17% phenolic compounds. Conclusion: G. Graciliflora has antifungal activity against clinical strains of C. albicans and exhibits proteins, sugars and phenolic compounds in its chemical composition.

Antimicrobial activity of mouth rinses against bacteria that initially colonizes dental's surface / Atividade antimicrobiana de enxaguatórios bucais sobre bactérias que iniciam a colonização das superfícies dentais

Abstract Introduction Much advertising in mouthwash is conveyed in all media appealing to the anti-plaque effect and rendering a disservice to the community. Mouth rinses are available over-the-count and differ on their compositions and antimicrobial effectiveness. Objective In this study, we evaluated the antimicrobial activity of 35 widely available mouth rinses against bacterial species involved in initiation of dental biofilm - Streptococcus gordonii, Streptococcus mitis, Streptococcus oralis, Streptococcus salivarius, and Streptococcus sanguinis. Material and method The Minimum Inhibitory Concentration (MIC) and the Minimum Bactericidal Concentration (MBC) of the evaluated mouth rinses were determined according to the Clinical & Laboratory Standards Institute protocols. Data were submitted to Kruskal-Wallis test and Mann-Whitney post hoc (α=0.05). Result About 70% of the mouth rinses achieved high antibacterial activity and 30%, a low antibacterial activity against all the species tested. The most ineffective mouth rinse showed antibacterial activity (MIC) at 1:1 dilution, while the most effective showed activity even at 1:2048 dilution, which may imply prolonged effect in the mouth. About 51% of mouth rinses showed bactericidal activity, and it was verified that cetylpyridinium chloride or chlorhexidine digluconate containing in the formulation were associated with the highest activity. Conclusion Most - but not all - mouth rinses commercially available are effective in inhibiting in vitro initial colonizers of dental surfaces.

Resumo Introdução Muita publicidade sobre enxaguatórios bucais é veiculada em todos os meios de comunicação apelando para o efeito anti-placa e prestando um desserviço à comunidade. Grande quantidade de enxaguatórios bucais está disponível no mercado e estes diferem em suas composições e eficácia antimicrobiana. Objetivo Neste estudo, avaliamos a atividade antimicrobiana de 35 enxaguatórios bucais amplamente disponíveis contra espécies bacterianas envolvidas na iniciação do biofilme dental - Streptococcus gordonii, Streptococcus mitis, Streptococcus oralis, Streptococcus salivarius e Streptococcus sanguinis. Material e método A Concentração Inibitória Mínima (CIM) e a Concentração Bactericida Mínima (CBM) dos enxaguatórios avaliados foram determinadas de acordo com os protocolos do Clinical & Laboratory Standards Institute. Os dados foram submetidos ao teste Kruskal-Wallis e Mann-Whitney post hoc (α=0,05). Resultado Aproximadamente 70% dos enxaguatórios bucais alcançaram alta atividade antibacteriana e 30%, baixa atividade antibacteriana contra todas as espécies testadas. O enxaguatório bucal mais ineficaz mostrou atividade antibacteriana (CIM) na diluição de 1:1, enquanto a mais eficaz mostrou atividade mesmo na diluição de 1:2048, o que pode implicar em efeito prolongado na boca. Cerca de 51% dos enxaguatórios bucais apresentaram atividade bactericida, e verificou-se que formulações contendo cloreto de cetilpiridíneo ou digluconato de clorexidina estavam associados à maior atividade. Conclusão A maior parte - mas não todos - dos enxaguatórios bucais comercialmente disponíveis são eficazes na inibição de colonizadores iniciais de superfícies dentárias in vitro.

Bactericidal Effect of the Aos Denti Germ for Denture Cleansing Effervescent Tablet against Oral Microorganisms

Human mouth environment is known to include a variety bacteria, including Streptococcus spp., Staphylococcus spp., Actinomyces spp., Lactobacillus spp., Candida spp., Enterobacteriaceae, et al. Human oral microorganisms can cause dental caries, gingivitis, periodontitis, respiratory tract infection, and cardiovascular disease. Thus, right denture cleaning is essential to oral and general human health. The aim of this study was to evaluate the bactericidal effect of a sodium dichloroisocyanurate-based effervescent tablet (Aos Denti Germ, Aos Company, Chungbuk, Korea) against oral microorganisms. A total of 5 species Streptococcus spp. (Streptococcus anginosus, Streptococcus mitis, Streptococcus mutans, Streptococcus oralis, and Streptococcus sobrinus), Actinomyces oris, Candida albicans, and Escherichia coli were used in this study. All strains were exposed to the distilled water prepared with effervescent tablet. After the exposure, the mixture of strains and effervescent tablet was inoculated onto blood agar or MacConkey agar plate and cultured at 36℃. All strains were killed immediately on exposure to effervescent tablet. The results suggested that effervescent tablet could be used as an effective denture cleanser for dental hygiene.

Molecular Identification of Bacterial Species Present on Toothbrushes

Toothbrushes play an essential role in oral hygiene. However, they can be significant in microbial transmission and can increase the risk of infection, since they can serve as a reservoir for microorganisms in healthy, oral-diseased and medically ill adults. This study was conducted to evaluate toothbrush contamination in six toothbrushes donated from four people. Two participants each supplied two toothbrushes - one used in the bathroom and one used in the workplace. The other two people each donated two toothbrushes used in the workplace. Polymerase chain reaction was used to construct a 16S rRNA clone library. Sequences of cloned DNA were compared with those from the reference organisms provided by GenBank. A total 120 clones, representing 20 clones for each toothbrush, were analyzed. They are composed of six pylum, 46 genera and 79 species. The most dominant species were Streptococcus oralis, Streptococcus parasanguinis and Haemophilus parainfluenzae. Enterobacter and Escherichia were recovered from toothbrushes used domestically. Toothbrushes used in the workplace did not contain Enterobacteria.

Clinical and microbiological evaluation of one-stage full-mouth disinfection: a short-term study / Avaliação clínica e microbiológica do protocolo one-stage full-mouth disinfection: estudo de curto prazo

Introduction: Patients seem to adhere better to short-term periodontal treatment schemes. Besides, time-reduced treatments are more cost-effective. However, the degree of benefits related to this type of treatment still requires additional investigations. Aim: The present short-term study evaluated clinical and microbiological outcomes, from baseline to 3-months, of chronic periodontitis subjects treated by the one-stage full-mouth disinfection protocol. Material and Method: Sixteen chronic periodontitis subjects (mean-age 49.87 ± 8.22) who met inclusion/exclusion criteria were included. A calibrated examiner measured whole-mouth plaque and gingival indices, periodontal pocket depth and clinical attachment level at baseline and at 3-months. Subgingival samples were also collected from the 5 most diseased periodontal sites to determine total bacterial load and levels of P. gingivalis and S. oralis by real time qPCR. Periodontal treatment consisted of full-mouth manual debridement plus wide intraoral use of chlorhexidine in gel and solution. Additionally, after debridement, individuals rinsed 0.12% chlorhexidine at home twice a day for the following 2 months. Data monitored were compared by paired Student-t test (p<0.05). Result: Statistical analysis revealed that, in general, one-stage full-mouth disinfection treatment provided significant clinical and microbiological improvements at 3-months. Total bacterial load showed one of the most pronounced reductions from baseline to 3-months (p=0.0001). Also, subgingival levels P. gingivalis and S. oralis reduced overtime. Conclusion: After a short period of monitoring, chronic periodontitis subjects showed clinical and microbial improvements following one-stage full-mouth disinfection treatment.

Introdução: Os pacientes parecem aderir melhor ao tratamento periodontal de curto prazo. Além disso, tratamentos de tempo curto possuem melhor custo-benefício. No entanto, os benefícios associados a este tipo de tratamento ainda requerem investigações adicionais. Objetivo: O presente estudo avaliou longitudinalmente indivíduos com periodontite crônica clínica e microbiologicamente tratados pelo protocolo one-stage full-mouth disinfection. Material e Método: Dezesseis indivíduos (49,87 ± 8,22), que se enquadraram nos critérios de inclusão/exclusão foram incluídos. Um examinador calibrado, avaliou índice de placa e gengival, profundidade de bolsa e nível clínico de inserção pré e pós terapia. Amostras subgengivais coletadas dos cinco sítios periodontais mais doentes estabeleceram a carga bacteriana total e níveis de P. gingivalis e S. oralis por qPCR. One-stage full-mouth disinfection foi realizado com instrumentos manuais associado a gel de clorexidina e solução. Após, os indivíduos utilizaram clorexidina 0,12% para bochecho, duas vezes ao dia, durante os dois meses. Dados foram comparados pelo teste pareado t de Student (p<0,05). Resultado: A análise estatística revelou que o tratamento proporcionou melhorias clínicas e microbianas significativas em três meses. A carga bacteriana total evidenciou reduções mais pronunciadas do pré para o pós-tratamento (p=0,0001). Similarmente, P. gingivalis e S. oralis mostraram redução no pós-tratamento. Conclusão: Após 3 meses de monitoramento, indivíduos com periodontite crônica apresentaram melhora clínica e microbiana com o protocolo one stage full-mouth disinfection.

Atividade antibacteriana in vitro de fitoconstituintes sobre micorganismos do biofilme dentário / In vitro antibacterial activity of phytochemicals on dental biofilm microorganisms

Objetivo: Avaliar in vitro a atividade antimicrobiana docitronelol, linalol, timol e D-limoneno frente a Streptococcus mutans, S. salivarius e S. oralis. Materiale Métodos: Realizou-se um screening pela técnica de difusão em meio sólido. Discos de papel absorvente foram em bebidos com 30 μL da substância-teste e dispostos em placas dePetri contendo Ágar Müeller Hinton previamente semeadas com inóculo bacteriano. Após incubação por 24h a 37ºC, foi realizada a mensuração dos halos de inibição do crescimento bacteriano com auxílio de um paquímetro manual. A clorexidina2% foi utilizada como controle positivo. O estudo foi realizado em triplicata. Resultados: O citronelol obteve média do diâmetro dos halos, em milímetros (mm), para S. mutans, S.oralis e S. salivarius, respectivamente: 10.7, 10.0 e 9.8. Otimol, para a mesma sequência de microorganismos: 7.3, 7.3e 8.3 mm. O D-limoneno exibiu médias de 8.0, 6.7 e 6.0 mmpara S. mutans, S. oralis e S. salivarius, respectivamente.Mensurou-se médias dos halos de 8.0, 9.0 e 8.2 mm, para os mesmos microorganismos, quando testado o linalol. Aclorexidina, por sua vez, apresentou média dos diâmetros dos halos de 17 mm para S. mutans, 16.8 mm para S. oralis e19.7 mm para S. salivarius. Conclusão: Os produtos avaliados apresentaram atividade antibacteriana,representando possíveis substâncias com aplicabilidade na prevenção da cárie dentária.

Objective: To evaluate the in vitro antibacterial activity ofcitronellol, linalool, thymol, and D-limonene againstStreptococcus mutans, S. salivarius and S. oralis. Materialand Methods: It was performed a screening by the diffusiontechnique on solid medium. Absorbent paper discs weresoaked with 30 μl of the tested substance and then placedon petri dishes containing Mueller Hinton agar previously sownwith the bacterial inoculum. After incubation for 24 h at 37 °C,it was measured the halo of growth inhibition with the aid ofa manual caliper. Chlorhexidine (2%) was used as positivecontrol. Tests were performed in triplicate. Results: Forcitronellol, the means of the diameters of the halos, in millimeters (mm), were 10.7, 10.0, and 9.8 against S. mutans,S. salivarius and S. oralis respectively. The values foundfor thymol were 7.3, 7.3 and 8.3 mm, respectively. Thephytochemical D-limonene exhibited means of 8.0, 6.7 and6.0 mm, respectively. For linalool, the means of the haloswere 8.0 mm, 9.0 mm and 8.2 mm. Chlorhexidine was foundto show means of 17, 16.8 and 19.7 mm on S. mutans, S.oralis and S. salivarius respectively. Conclusion: The products under test showed antibacterial activity, being therefore potential substances to be applied for dental caries prevention.

Molecular Discrimination of Mitis Group Streptococci Isolated from Koreans using RpoB Nucleotide Sequences

Mitis group streptococci (MGS) were classified based on the nucleotide sequences 16S rRNA gene (16S rDNA) and comprised 13 Streptococcus species. However, 16S rDNA homogeneity among MGS was too high to discriminate between clinical strains at the species level, notably between Streptococcus mitis, Streptococcus oralis, Streptococcus pneumoniae, and Streptococcus pseudopneumoniae. The purpose of this study was to discriminate between 37 strains of MGS isolated from Korean oral cavities using phylogenetic analysis of the DNA-dependant RNA polymerase beta-subunit gene (rpoB). 16S rDNA and rpoB from clinical strains of MGS were sequenced using the dideoxy chain termination method and analyzed using MEGA version 5 software. The resulting phylogenetic data showed that the rpoB sequences could delineate clinical strains of MGS at the species level. Phylogenetic analysis of rpoB is therefore a useful approach for identifying MGS at the species level.

Efeito antimicrobiano de tinturas de produtos naturais sobre bactérias da cárie dentária / Antimicrobial effect of natural dyeing products upon decaycausing bacteria

Objetivo: Avaliar as atividades bacteriostática e bactericida de tinturas de Rosmarinus officinalis (Alecrim), Calendula officinalis(Calêndula) e Mikania glomerata (Guaco) sobre bactérias da cárie dentária e compará-las às da clorexidina. Métodos: A Concentração Inibitória Mínima (CIM) foi determinada pela técnica da microdiluição, utilizando microplacas de 96 furos. Em cada poço foram inseridos 10μL do inóculo (108células/mL), 100μL de caldo BHI duplamente concentrado e 100μL das tinturas, em concentrações que variaram de 100 a 0,78mg/mL, para T1, T2 e T3. Como controle positivo foi utilizado a Clorexidina 0,12%. A leitura foi feita após 24 horas, pelo método visual. Os ensaios foram realizados em triplicata. A Concentração Bactericida Mínima (CBM) foi obtida pela semeadura da última concentração bacteriostática e da sua anterior, para cada produto, em meio Ágar Sangue. Foram consideradas CBM as placas que não apresentaram crescimento bacteriano. Resultados: Sobre Streptococcus mutans, verificou-se CIM de 6,25mg/mL, para T1, T2 e T3 e CBM de 12,5mg/mL para T1 e T2 e de 6,25mg/mL para T3. Sobre Streptococcus oralis todos os produtos apresentaram CIM e CBM de 0,78mg/mL. Para clorexidina, a CIM e CBM foram 0,04mg/mL, sobre S. mutans e S. oralis. Conclusão: As tinturas de Alecrim, Calêndula e Guaco apresentaram ação bactericida e bacteriostática em baixas concentrações, sobre Streptococcus mutans e Streptococcus oralis, entretanto a atividade antimicrobiana da Clorexidina foi superior a das tinturas.

Objective: To evaluate the bacteriostatic and bactericidal activities of tinctures of Rosmarinus officinalis (Rosemary), Calendula officinalis (Marigold) and Mikania glomerata (Guaco) upon decay-causing bacteria and compare them to chlorhexidine’s. Methods: The Minimum Inhibitory Concentration (MIC) was determined by microdilution technique, using 96-well microplates. In each well were inserted 10μL of inoculum (108 cells/mL), 100μL of doubly concentrated BHI broth and 100μL of tinctures at concentrations that vary between 100 and 0.78 mg/mL for T1, T2 and T3. As positive control, Chlorhexidine 0.12% was used. Reading was performed after 24 hours, by visual method. The assays were realized in triplicate. Minimum Bactericidal Concentration (MBC) was obtained by seeding of last bacteriostatic and its preceding concentrations, for each product, on Blood Agar. The MBC was considered in the plates that did not present any bacterial growth. Results: Upon Streptococcus mutans, MIC was verified at 6.25mg/mL, for T1, T2, and T3 and MBC at 12.5mg/mL for T1 and T2, and at 6.25mg/mL for T3. Upon Streptococcus oralis, all products presented MIC and MBC at 0.78mg/mL. For Chlorhexidine, the MIC and MBC were 0,04mg/mL, upon S. mutans and S. oralis. Conclusion: The tinctures of Rosemary, Marigold and Guaco showed bactericidal and bacteriostatic activities at low concentrations, upon Streptococcus mutans e Streptococcus oralis. However, the antimicrobial activity of chlorhexidine was superior to the tinctures’.

Eficácia antimicrobiana do extrato do Croton sonderianus Müll. sobre bactérias causadoras da cárie dentária / Antimicrobial efficacy of the extract of Croton sonderianus Müll. on bacteria that cause dental caries

Este trabalho tem como objetivo avaliar a atividade antimicrobiana do extrato do Croton sonderianus (marmeleiro) frente a bactérias que fazem parte do biofilme dental, como Streptococcus salivaris, mutans, mitis, sanguis e sobrinus. Os ensaios foram realizados pela técnica de difusão em meio sólido com base no tamanho dos halos de inibição. Os mesmos procedimentos foram utilizados com a clorexidina. Os resultados mostraram que todas as amostras ensaiadas foram sensíveis ao extrato com CIM (mg.mL-1) de 1:16 (0,62%), 1:32 (0,31%), 1:64 (0,15%), 1:32 (0,31%), 1:16 (0,62%), respectivamente. S. mitis foi a linhagem mais sensível. Os resultados mostram a potencialidade do extrato do Croton sonderianus na inibição do crescimento bacteriano de micro-organismos formadores do biofilme dental, sugerindo a possibilidade do emprego desse extrato como meio alternativo no controle desses patógenos naprática odontológica.

This study aims to evaluate the antimicrobial activity of the extract of Croton sonderianus (marmeleiro) against bacteria that are part of the biofilm, such as Streptococcus salivaris, mutans, mitis, sanguis, sobrinus. The tests were carried out by diffusion technique on solid medium based on the size of inhibition zones. The same procedures were used with chlorhexidine. The results showed that all samples tested were sensitive to the extract with MIC (mg.mL-1) of 1:16 (0.62%), 1:32 (0.31%), 1:64 (0.15%) 1:32 (0.31%), 1:16 (0.62%), respectively. S. mitis strainwas more sensitive. The results show the potential of the extract of Croton sonderianus in growth inhibition of microorganisms forming the biofilm suggesting the possibility of using this extract as an alternative means to control these pathogens in dental practice.

Multispecies communities: interspecies interactions influence growth on saliva as sole nutritional source / 国际口腔科学杂志·英文版

Human oral bacteria live in multispecies communities in the biofilm called dental plaque. This review focuses on the interactions of seven species and the ability of each species individually and together with other species to grow on saliva as the sole source of nutrient. Community formation in biofilms in flow cells is monitored using species-specific fluorophore-conjugated immunoglobulin G, and images are captured by confocal microscopy. Early colonizing veillonellae emerge from this review of interspecies interactions in saliva as a critical genus that guides the development of multispecies communities. Highly selective interspecies recognition is evident as initial colonizers pair with early and middle colonizers to form multispecies communities that grow on saliva.

Influences of trans-trans farnesol, a membrane-targeting sesquiterpenoid, on Streptococcus mutans physiology and survival within mixed-species oral biofilms / 国际口腔科学杂志·英文版

Trans-trans farnesol (tt-farnesol) is a bioactive sesquiterpene alcohol commonly found in propolis (a beehive product) and citrus fruits, which disrupts the ability of Streptococcus mutans (S. mutans) to form virulent biofilms. In this study, we investigated whether tt-farnesol affects cell-membrane function, acid production and/or acid tolerance by planktonic cells and biofilms of S. mutans UA159. Furthermore, the influence of the agent on S. mutans gene expression and ability to form biofilms in the presence of other oral bacteria (Streptococcus oralis (S. oralis) 35037 and Actinomyces naeslundii (A. naeslundii) 12104) was also examined. In general, tt-farnesol (1 mmol x L(-1)) significantly increased the membrane proton permeability and reduced glycolytic activity of S. mutans in the planktonic state and in biofilms (P < 0.05). Moreover, topical applications of 1 mmol x L(-1) tt-farnesol twice daily (1 min exposure/treatment) reduced biomass accumulation and prevented ecological shifts towards S. mutans dominance within mixed-species biofilms after introduction of 1% sucrose. S. oralis (a non-cariogenic organism) became the major species after treatments with tt-farnesol, whereas vehicle-treated biofilms contained mostly S. mutans (>90% of total bacterial population). However, the agent did not affect significantly the expression of S. mutans genes involved in acidogenicity, acid tolerance or polysaccharide synthesis in the treated biofilms. Our data indicate that tt-farnesol may affect the competitiveness of S. mutans in a mixed-species environment by primarily disrupting the membrane function and physiology of this bacterium. This naturally occurring terpenoid could be a potentially useful adjunctive agent to the current anti-biofilm/anti-caries chemotherapeutic strategies.

Cell surface proteins in S. pneumoniae, S. mitis and S. oralis

Streptococcus pneumoniae, a major human pathogen, is closely related to the commensal species S. mitis and S. oralis. S. pneumoniae surface proteins are implicated in virulence and host interaction of this species, but many of them have recently been detected in S. mitis B6 in silico. We tested for the presence of such genes usinga set of eight S. mitis and eleven S. oralis strains from different geographic locations. An oligonucleotide microarray was designed based on the genomes of S. pneumoniae R6 and TIGR4 as well as S. mitis B6 to include 63 cell surface proteins. The S. pneumoniae genes encoding neuraminidases, hyaluronidase and pneumolysin were also included. In addition to comparative genomic hybridization experiments, homologues were identified in silico in the genome of S. oralis Uo5. The results document that many S. pneumoniae related surface proteins are ubiquitously present among the Mitis group of streptococci. All 19 samples hybridized with the pavA probe representing a gene important for adherence and invasion of S. pneumoniae. Only eight genes were not recognized in any strain, including the S. pneumoniae PcpC gene as the only virulence gene of the S. pneumoniae core genome.The fact that only 12 out of 26 genes present in the S. oralis Uo5 genome could be detected by microarray analysis confirms the sequence variation of surface components

Analysis of community composition in dental plaque of elder people with root caries / 中华口腔医学杂志

<p><b>OBJECTIVE</b>To analyze the community in dental plaque of elder people with root caries.</p><p><b>METHODS</b>Total DNAs were extracted from the root caries dental plaques of nine elders over 60 years of age. Polymerase chaid reaction-based denaturing gradient gel electrophoresis (PCR-DGGE) was used to analyze the microbial composition, DGGE bands were excised from the gels for sequencing and identification.</p><p><b>RESULTS</b>The dominant genus in root caries dental plaque of elder people were: Acinetobacte [0.9% (1/114)], Actinobaculum [1.8% (2/114)], Actinomyces [15.8% (18/114)], Aggregatibacter [0.9% (1/114)], Capnocytophaga [14.0% (16/114)], Corynebacterium [0.9% (1/114)], Haemophilus [0.9% (1/114)], Mobiluncus [0.9% (1/114)], Naxibacter [0.9% (1/114)], Neisseriaceae [10.5% (12/114)], Porphyromonas [0.9% (1/114)], Prevotella [12.3% (14/114)], Selenomonas [6.1% (7/114)], Staphylococcus [1.8% (2/114)], Oralis streptococcus [6.1% (7/114)], Mutans streptococcu [7.9% (9/114)], Tannerella [0.9% (1/114)], Treponema [1.8% (2/114)], Veillonella [10.5% (12/114)] and two uncultured unknown genus [1.8% (2/114)]. Uncultred genotypes accounted for 19.30% of the total. Gram-positive bacteria genotype accounted for 31.6% (36/114), and Gram-negative bacteria genotype accounted for 66.7% (76/114).</p><p><b>CONCLUSIONS</b>There were many bacteria genotypes in root caries dental plaque in the elderly, which were widely distributed. Gram-negative bacteria accounted for the majority. Genotype-specific pathogenic bacteria were not found.</p>

Detection and analysis of comE and luxS genes in quorum sensing signal pathway from Streptococcus oralis / 华西口腔医学杂志

<p><b>OBJECTIVE</b>To detect and analyze two important genes, comE and luxS, in quorum sensing signal pathway from Streptococcus oralis (S. oralis).</p><p><b>METHODS</b>The total genomic DNA of S. oralis NH521 (a clinically isolated strain) was firstly extracted. The comE and luxS genes were then amplified by polymerase chain reaction (PCR) and further sequenced. The obtained sequences were compared with related sequences in GenBank.</p><p><b>RESULTS</b>Target bands of both comE and luxS genes were detected by electrophoresis. The obtained gene sequences were similar to the corresponding sequences from another S. oralis strain (luxS, 95.0%; comE, 99.6%); however, comparing to gene sequences of another species Streptococcus mutans, comE was more divergent (12.7%) than luxS gene (74.1%).</p><p><b>CONCLUSION</b>This study successfully amplified and sequenced comE and luxS genes from S. oralis NH521 strain. The luxS gene accumulated more mutations than comE gene did between two S. oralis strains, but comE gene is more divergent than luxS gene between two Streptococcus species.</p>

Antimicrobial action of root canal filling pastes used in deciduous teeth / Ação antimicrobiana de pastas obturadoras usadas em dentes decíduos

Purpose: This study assessed the antimicrobial effectiveness of an iodoform-based paste (Guedes-Pinto Paste, GPP) and a paste modified by the addition of a 2% chlorhexidine gluconate gel (CHX) to replace the camphorated parachlorophenol component of the original GPP. Methods: The antimicrobial action was tested against the following microorganisms: Staphylococcus aureus, Staphylococcus epidermidis, Streptococcus oralis, Enterococcus faecalis, Escherichia coli and Bacillus subtilis. In the agar diffusion test, 18 Petri plates with 20 mL of BHIA were inoculated with 0.1 mL of the microbial suspensions. Paper disks were immersed in the experimental solutions for 1 min and were then placed over the BHIA surface in each agar plate. The plates were maintained for 1 h at room temperature and then incubated at 37ºC for 48 h. The diameters of the microbial inhibition halos were measured around the paper disks containing the substances. Data were analyzed using the Mann-Whitney U-test (alpha=0.05). Results: Antimicrobial action was observed for the GPP and CHX pastes, which presented absence of turbidity for almost all microorganisms. No statistically significant difference in the antimicrobial action was found between GPP and CHX. Conclusion: Both pastes present similar antimicrobial effectiveness against several microorganisms commonly found in endodontic infections in deciduous teeth.

Objetivo: Este estudo avaliou a ação antimicrobiana de pastas, uma à base de iodofórmio conhecida por Pasta Guedes-Pinto (PGP) e outra modificada pela adição de digluconato de clorexidina (CHX) a 2% em substituição ao paramonoclorofenol canforado da formulação original da PGP. Metodologia: A ação antimicrobiana das duas pastas foi testada contra Staphylococcus aureus, Staphylococcus epidermidis, Streptococcus oralis, Enterococcus faecalis, Escherichia coli e Bacillus subtilis. O método empregado foi o de Diluição em Meio Sólido, Difusão em Ágar. Dezoito placas de Petri com 20 mL de BHIA foram inoculados com 0,1 mL das suspensões microbianas. Discos de papel foram imersos nas soluções experimentais por 1 min e colocados sobre a superfície de BHIA em cada placa. As placas foram mantidas em temperatura ambiente por 1 h e então incubadas a 37ºC por 48 h. O diâmetro da inibição microbiana foi medida ao redor dos discos de papel. Os dados foram pelo teste U de Mann-Whitney (alfa=0,05). Resultados: A PGP teve ação bacteriostática contra todos os microrganismos e também bactericida exceto para Enterococcus faecalis e Bacillus subtilis. A CHX apresentou ação bacteriostática e bactericida contra todos os microrganismos. Não houve diferença estatística significante quanto à efetividade antimicrobiana entre as pastas avaliadas. Conclusão: Ambas as pastas apresentaram ação antimicrobiana contra quase todos os microrganismos encontrados em infecções endodônticas de dentes decíduos.

Avaliação in vitro do potencial antibacteriano de cimentos de ionômericos de vidro / In vitro evaluation of antibacterial effects of glass ionomers cements

Objetivo: Avaliar in vitro a atividade antibacteriana de Cimentos de Ionômeros de Vidro (CIV) convencionais sobre as cepas de Streptococcus salivarius (ATCC 7073), Streptococcus oralis (ATCC 10557) e Lactobacillus casei (ATCC 7469). Material e Métodos: Manipularam-se os CIVs: G1: Vitro Fil® (DFL); G2: Vidrion R® (SSWhite) e G3: Magic Glass® (Vigodent), para preparar 6 corpos-de-prova de cada material, com 6mm de diâmetro por 3mm de altura, utilizando tubetes anestésicos. A análise antimicrobiana foi realizada pela técnica da difusão em Ágar Sangue. As placas foram semeadas pelo inoculo à 108 UFC/mL, e os corpos-de-prova foram inseridos no meio de cultura em poços de 6mm de diâmetro. Cada placa bacteriana recebeu 1 corpos-de-prova de cada grupo e foram incubadas em estufa bacteriológica a 37º por 24 horas, para posterior mensuração dos halos de inibição. Resultados: Os dados foram submetidos aos testes estatísticos ANOVA e Tukey (α=5 por cento). Na placa de S. salivarius, as médias dos halos foram para G1 e G3: 11,5mm e G2: 13,5mm, não apresentando diferenças estatisticamente significantes (p>0,05). Já para S. oralis, apenas o G3 obteve ação, com média de halos em 13mm. Frente ao L. casei, nenhum CIV provocou inibição bacteriana. Conclusão: Os resultados demonstraram que as cepas apresentaram diferente sensibilidade sobre os ionômeros testados, tendo o Magic Glass® os maiores halos de inibição de crescimento.

Faringotonsilites na infância: diagnóstico e tratamento / Pharyngotonsilites in childhood: diagnosis and treatment

Os autores discorrem sobre a anatomofisiologia do anel linfático de Waldeyer, a microbiologia das faringotonsilites, o quadro clínico, diagnóstico e tratamento das infecções de etiologia bacteriana - estreptocócica, diftérica, fuso-espiralar, luética, eritematosa, difteróide e formas hemopáticas e gangrenosa -, bem como de etiologia viral e suas complicações, em cada caso. Atualizam o tratamento sintomático, antibioticoterapia e a terapêutica cirúrgica.

Influence of environmental factors on synthesis rate of hydrogen peroxide by Streptococcus oralis / 中华口腔医学杂志

<p><b>OBJECTIVE</b>To investigate the influence of a broad range of environmental conditions on initial rates of hydrogen peroxide produced by Streptococcus oralis (S. oralis).</p><p><b>METHODS</b>For each rate measurement, 1 ml aliquots of 10(12) cells/L mid-logarithmic phase S. oralis in TSBY were centrifuged and respectively washed by phosphate buffer containing 0.01-10 mmol/L glucose or sucrose, phosphate buffer with 5.0-7.5 pH or Bis-Tris buffer containing 0.01-100 mmol/L Ca(2+), 0.01-100 mmol/L F(-) or 0.01-100 mmol/L HFPO(3)(-). After S. oralis was cultured in respective buffer for 10, 20 and 30 min at 37 degrees C, the concentration of hydrogen peroxide in supernatant was assayed spectrophotometrically in 96-well micro-plate by ABTS-HRP at A(405).</p><p><b>RESULTS</b>Synthesis rate of hydrogen peroxide by S. oralis was 7.48 micromol/L per minute without carbohydrate, the synthesis rate of hydrogen peroxide by S. oralis increased with 0.01-10 mmol/L glucose and 0.01-10 mmol/L sucrose, but there was no statistically significant difference in synthesis rate among the carbohydrate groups. The rates of H2O2 synthesis were inhibited in the buffer at pH 5.0-6.0, compared with pH 7.0 (P < 0.05). Ca(2+) had little influence on the rate of H2O2 synthesis. IC(50) of H2O2 synthesis rates by S. oralis responded to FHPO(3)(-) and F(-) were 12.65 mmol/L and 1.90 mmol/L respectively.</p><p><b>CONCLUSIONS</b>Environmental conditions may influence the synthesis rate of H2O2 by S. oralis.</p>

Atividade antimicrobiana, in vitro, de soluções anestésicas tópicas comerciais / Antimicrobial activity of typical anesthetics against streptococci strains - in vitro

O objetivo deste trabalho foi avaliar a atividade antimicrobiana de anestésicos tópicos comerciais sobre cepas de estreptococos. Concentrações inibitória(CIM) e bactericida (CBM) mínimas destes produtos contendo lidocaína 5 por cento, lidocaína 6 por cento, lidocaína 10 por cento, benzocaína 10 por cento e benzocaína 20 por cento foram obtidas, sendo utilizados caldo Mueller Hinton e ágar Mitis salivarius para CIM e CBM, respectivamente, e Strepococcus mutans Ingbritt 1600, Streptococcus sanguis ATCC 10556, Streptococcus salivarius AE 112, S. oralis e S. mutans (cepas de campo). Os testes foram realizados a 37ºC, 10 por cento CO2, durante 48 horas. Todos os anestésicos mostraram atividade antimicrobiana dose-dependente contra os estreptococos, sendo a CIM geralmente similar à CBM, com exceção do anestésico Xylestesin 5 por cento.