RESUMO
The oral cavity harbors several Streptococcus mutans genotypes, which could present distinct virulence properties. However, little is known about the diversity and virulence traits of S. mutans genotypes isolated in vivo under controlled conditions of high cariogenic challenge. This study evaluated the genotypic diversity of S. mutans isolated from dental biofilms formed in vivo under sucrose exposure, as well as their acidogenicity and aciduricity. To form biofilms, subjects rinsed their mouths with distilled water or sucrose solution 8 times/day for 3 days. S. mutans collected from saliva and biofilms were genotyped by arbitrarily-primed PCR. Genotypes identified in the biofilms were evaluated regarding their ability to lower the suspension pH through glycolysis and their acid susceptibility and F-ATPase activity. Most subjects harbored only one genotype in saliva, which was detected in almost all biofilm samples at high proportions. Genotypes isolated only in the presence of sucrose had higher acidogenicity than those isolated only in the presence of water. Genotypes from biofilms formed with sucrose were more aciduric after 30 and 60 min of incubation at pH 2.8 and 5.0, respectively. The present results suggest that biofilms formed under high cariogenic conditions may harbor more aciduric and acidogenic S. mutans genotypes.
Assuntos
Biofilmes , Cariogênicos/administração & dosagem , Boca/microbiologia , Streptococcus mutans/classificação , Sacarose/administração & dosagem , Ácidos , Adolescente , Adulto , ATPases Bacterianas Próton-Translocadoras/análise , Estudos Cross-Over , Depósitos Dentários/microbiologia , Variação Genética/genética , Genótipo , Glicólise , Humanos , Concentração de Íons de Hidrogênio , Viabilidade Microbiana , Fenótipo , Reação em Cadeia da Polimerase , Saliva/microbiologia , Streptococcus mutans/genética , Streptococcus mutans/patogenicidade , Fatores de Tempo , Virulência , Água/administração & dosagem , Adulto JovemRESUMO
The oral cavity harbors several Streptococcus mutans genotypes, which could present distinct virulence properties. However, little is known about the diversity and virulence traits of S. mutans genotypes isolated in vivo under controlled conditions of high cariogenic challenge. This study evaluated the genotypic diversity of S. mutans isolated from dental biofilms formed in vivo under sucrose exposure, as well as their acidogenicity and aciduricity. To form biofilms, subjects rinsed their mouths with distilled water or sucrose solution 8 times/day for 3 days. S. mutans collected from saliva and biofilms were genotyped by arbitrarily-primed PCR. Genotypes identified in the biofilms were evaluated regarding their ability to lower the suspension pH through glycolysis and their acid susceptibility and F-ATPase activity. Most subjects harbored only one genotype in saliva, which was detected in almost all biofilm samples at high proportions. Genotypes isolated only in the presence of sucrose had higher acidogenicity than those isolated only in the presence of water. Genotypes from biofilms formed with sucrose were more aciduric after 30 and 60 min of incubation at pH 2.8 and 5.0, respectively. The present results suggest that biofilms formed under high cariogenic conditions may harbor more aciduric and acidogenic S. mutans genotypes.
A cavidade oral apresenta vários genótipos de Streptococcus mutans, que podem possuir diferentes capacidades de virulência. Entretanto, pouco se sabe sobre a diversidade e virulência de genótipos de S. mutans isolados in vivo sob uma condição controlada de alto desafio cariogênico. Este estudo avaliou a diversidade genotípica de S. mutans identificados no biofilme dental formado in vivo na presença de sacarose, assim como a acidogenicidade e aciduricidade desses genótipos. Para possibilitar formação de biofilme, voluntários bochecharam com água destilada ou solução de sacarose 8x/dia durante 3 dias. S. mutans isolados da saliva e do biofilme dental foram genotipados por PCR com primers-arbitrários. Genótipos isolados do biofilme foram avaliados em relação à habilidade de reduzir o pH da suspensão devido à glicólise, em relação à susceptibilidade a ácidos e também atividade F-ATPase. A maioria dos voluntários apresentou apenas 1 genótipo na saliva, que foram detectados em quase todas as amostras de biofilme em altas proporções. Genótipos isolados somente na presença de sacarose apresentaram maior acidogenicidade do que aqueles genótipos isolados apenas na presença de água. Genótipos de biofilmes formados na presença de sacarose foram mais acidúricos após 30 e 60 min de incubação em pH 2,8 e 5,0, respectivamente. Os resultados do presente estudo sugerem que biofilmes formados sob condição de alto desafio cariogênico podem apresentar genótipos de S. mutans mais acidúricos e mais acidogênicos.
Assuntos
Adolescente , Adulto , Humanos , Adulto Jovem , Biofilmes , Cariogênicos/administração & dosagem , Boca/microbiologia , Streptococcus mutans/classificação , Sacarose/administração & dosagem , Ácidos , ATPases Bacterianas Próton-Translocadoras/análise , Estudos Cross-Over , Depósitos Dentários/microbiologia , Genótipo , Glicólise , Variação Genética/genética , Concentração de Íons de Hidrogênio , Viabilidade Microbiana , Fenótipo , Reação em Cadeia da Polimerase , Saliva/microbiologia , Streptococcus mutans/genética , Streptococcus mutans/patogenicidade , Fatores de Tempo , Virulência , Água/administração & dosagemRESUMO
AIM: The aim of this study was to evaluate the clinical and microbiological effects of scaling and root planing (SRP) alone or combined with metronidazole (MTZ) or with MTZ and amoxicillin (AMX) in the treatment of smokers with chronic periodontitis. METHODS: A double-blind, placebo-controlled, randomized clinical trial was conducted in 43 subjects who received SRP alone (n=15) or combined with MTZ (400 mg 3 x per day, n=14) or with MTZ+AMX (500 mg 3 x per day, n=14) for 14 days. Clinical and microbiological examinations were performed at baseline and 3 months post-therapy. Subgingival samples were analysed by checkerboard DNA-DNA hybridization. RESULTS: Subjects receiving MTZ+AMX showed the greatest improvements in mean probing depth and clinical attachment level. Both antibiotic therapies led to additional clinical benefits over SRP alone in initially shallow, intermediate, and deep sites. The SRP+MTZ+AMX therapy led to the most beneficial changes in the subgingival microbial profile. These subjects showed significant reductions in the mean counts and proportions of periodontal pathogens such as Tannerella forsythia, Porphyromonas gingivalis and Treponema denticola, and the greatest increase in proportions of host-compatible species. CONCLUSION: Significant advantages are observed when systemic antibiotics are combined with SRP in the treatment of smokers with chronic periodontitis. The greatest benefits in clinical and microbiological parameters are achieved with the use of SRP+MTZ+AMX.