RESUMO
This study investigated the association between clinical and salivary or molecular parameters in Down syndrome subjects. Sixty individuals (1- to 48-year old) were clinically examined using DMFT/DMFS. Stimulated saliva was collected; salivary flow was calculated (mL/min), buffering capacity was measured using a standard pH tape. In addition, 25 µL of saliva was diluted using 10-fold-dilution method and then placed on Mitis-Salivarius-Bacitracin agar to count colony forming units (CFU/mL) of mutans streptococci. Polymerase chain reaction analysis identified species. Caries indexes were 0.65-13.5 (DMFT) and 0.65-26.0 (DMFS) according to groups. Ninety-four percent of subjects had low flow rate (0.7-1.0 mL/min) and 44% had low buffering capacity (pH < 4). Besides, 60% had more than 1 × 10(6) CFU/mL, 60% had S. mutans, and 41.4% had S. sobrinus. Caries indexes did not significantly correlate with flow rate, buffering capacity, CFU/mL by Pearson's correlation (p > 0.05), and showed no significant association with prevalence of species by Chi-square (p > 0.05). There is no association between clinical picture and salivary or molecular parameters in Down syndrome subjects.
Assuntos
Índice CPO , Síndrome de Down/complicações , Saliva/microbiologia , Streptococcus mutans/classificação , Streptococcus sobrinus/classificação , Adolescente , Adulto , Carga Bacteriana , Soluções Tampão , Criança , Pré-Escolar , Cárie Dentária/microbiologia , Restauração Dentária Permanente/estatística & dados numéricos , Síndrome de Down/microbiologia , Humanos , Concentração de Íons de Hidrogênio , Lactente , Pessoa de Meia-Idade , Reação em Cadeia da Polimerase , Saliva/metabolismo , Taxa Secretória/fisiologia , Streptococcus/classificação , Extração Dentária/estatística & dados numéricos , Perda de Dente/classificação , Adulto JovemRESUMO
Due to the major role of Streptococcus mutans and Streptococcus sobrinus in the etiology of dental caries, it is important to use culture media that allow for differentiating these bacterial species. The aim of this study was to evaluate the suitability of a modified SB-20 culture medium (SB-20M) for the isolation and morphological differentiation of S. mutans and S. sobrinus, compared to biochemical identification (biotyping). Saliva samples were collected using the spatula method from 145 children, seeded on plates containing the SB-20M, in which sucrose was replaced by coarse granular cane sugar, and incubated in microaerophilia at 37°C during 72 h. Identification of the microorganisms was performed under stereomicroscopy based on colony morphology of 4904 colonies. The morphological identification was examined by biochemical tests of 94 randomly selected colonies with the macroscopic characteristic of S. mutans and S. sobrinus using sugar fermentation, resistance to bacitracin and production of hydrogen peroxide. There was no statistically significant difference (p>0.05) between morphological identification in the SB-20M medium and biochemical identification (biotyping). Biotyping confirmed that S. mutans and S. sobrinus colonies were correctly characterized in the SB-20M in 95.8% and 95.5% of the cases, respectively. Of the mutans streptococci detected in the children 98% were S. mutans and 2% S. sobrinus. The SB-20M medium is reliable for detection and direct morphological identification of S. mutans and S. sobrinus.
Assuntos
Técnicas de Tipagem Bacteriana/métodos , Meios de Cultura , Streptococcus mutans/classificação , Streptococcus sobrinus/classificação , Criança , Cárie Dentária/microbiologia , Humanos , Saliva/microbiologia , Streptococcus mutans/citologia , Streptococcus mutans/isolamento & purificação , Streptococcus sobrinus/citologia , Streptococcus sobrinus/isolamento & purificaçãoRESUMO
This study investigated the possible intrafamilial similarity of mutans streptococcal strains in some families with a child with Down syndrome using chromosomal DNA fingerprinting. The isolates were genotyped using arbitrarily primed polymerase chain reaction with the OPA 02 and OPA 03 primers. The results showed that five children with Down syndrome harbored mutans streptococci genotypes different from those of their mothers. A matching of genotypes was observed within the control pair (mother/child without Down syndrome). After six months, new samples were collected from all participants. Analysis showed that samples from children with Down syndrome were colonized by a new strain of Streptococcus mutans that did not match the previously collected one. The results suggest the S. mutans indigenous bacteria change more than once in children with Down syndrome.
Assuntos
Impressões Digitais de DNA/métodos , Primers do DNA , Síndrome de Down/microbiologia , Técnica de Amplificação ao Acaso de DNA Polimórfico/métodos , Streptococcus mutans/classificação , Adolescente , Criança , DNA Bacteriano/análise , Feminino , Seguimentos , Genótipo , Humanos , Masculino , Mães , Saliva/microbiologia , Streptococcus mutans/genética , Streptococcus sobrinus/classificação , Streptococcus sobrinus/genéticaRESUMO
The aim of this study was to perform a follow-up evaluation of the Streptococcus mutans and Streptococcus sobrinus colonization profile of children's oral cavities, which included the pattern of vertical transmission from mother to child, genotypic diversity, and stability of the strains. The subjects were 16 mother-child pairs, who were monitored for 20 months. Samples of saliva, tongue dorsum, alveolar ridge mucosa, and dental plaque from the children were collected bimonthly. Saliva samples from the mothers were also collected. After isolation and identification, the arbitrarily primed PCR method was performed for the genotypic characterization of S. mutans (968 isolates) and S. sobrinus (111 isolates). At the time the strains were acquired, the children harbored one to four distinct genotypes of S. mutans and only one genotype of S. sobrinus. Although S. mutans prevalence and genotypic diversity were greater than those of S. sobrinus, the presence of matching genotypes of S. mutans and S. sobrinus was similar (in 81.25 and 83.33% of mother-child pairs, respectively), suggesting vertical transmission for both species. This longitudinal study showed an increase in genotypic diversity of S. mutans in the oral cavity during the follow-up period: most of the initially acquired genotypes persisted, normally those genotypes transmitted by the mother, and some were lost during follow-up; new strains were also acquired. In conclusion, S. mutans and S. sobrinus genotypes acquired from maternal or alternative sources may show effective persistence in the oral cavity and/or transitory detection in the children's mouths, reflecting the continuous development of oral microbiota in children.
Assuntos
Saliva/microbiologia , Escolas Maternais , Streptococcus mutans/isolamento & purificação , Streptococcus sobrinus/isolamento & purificação , Língua/microbiologia , Adulto , Brasil , Pré-Escolar , Placa Dentária/microbiologia , Feminino , Variação Genética , Genótipo , Humanos , Lactente , Transmissão Vertical de Doenças Infecciosas , Estudos Longitudinais , Mães , Infecções Estreptocócicas/microbiologia , Streptococcus mutans/classificação , Streptococcus mutans/genética , Streptococcus sobrinus/classificação , Streptococcus sobrinus/genéticaRESUMO
The aim of the present study was to evaluate the colonization profile and clonal distribution of Streptococcus mutans isolated from oral cavities that presented coronal and root caries lesions. The isolation and biochemical identification of mutans streptococci were carried out by using saliva samples, dental plaque, and tissue from the caries lesions. In order to confirm their molecular identity, S. mutans and Streptococcus sobrinus were submitted to the PCR method, using specific primers for portions of the glucosyltransferase genes (gtfB and gtfI, respectively). The AP-PCR method was used to detect the genetic polymorphism of S. mutans strains. Among the isolated and identified species, S. mutans showed a significantly greater frequency of isolation (59.2%) than the other mutans streptococci. Each of the subjects harbored two to ten genotypes of S. mutans, randomly distributed in different sites. S. mutans genotypes showed no evidence of variability in colonizing noncarious and carious surfaces within the same individual, nor evidence of etiologic differences between coronal and root caries. This study showed that no particular genotype of S. mutans is uniquely associated with the initiation and progression of caries, and that root and coronal caries can emerge in the presence of a broad spectrum of S. mutans clones.