RESUMO
OBJECTIVE: The purpose of this study was to quantify nine selected cariogenic bacteria in plaque from sound root surfaces and initial carious root lesions using TaqMan PCR and to analyse a putative dependence on the kind of initial periodontal treatment. MATERIAL AND METHODS: Fifty-four subjects with generalized chronic periodontitis were randomly allocated to one of the following initial periodontal therapies: full-mouth disinfection, full-mouth scaling and root planing or scaling and root planing within 7 days. Plaque samples were taken before and after periodontal treatment and analysed by TaqMan PCR. RESULTS: The quantity of the cariogenic bacteria Actinomyces spp., Streptococcus mutans, Streptococcus sobrinus, Lactobacilllus spp., Rothia dentocariosa, Parvimonas micra, Propionibacterium acnes and Neisseria mucosa were significantly higher, while the quantity of Veillonella parvula was significantly lower on initial carious lesions than on the sound surfaces both before and after periodontal therapy. No significant differences could be found in any of the tested bacteria except P. micra on initial carious lesions and sound surfaces for both examinations between the groups. CONCLUSION: All the nine species analysed were found to be present in initial carious root lesions as well as sound root surfaces but in different quantities, independent of the different periodontal therapies.
Assuntos
Bactérias Gram-Negativas/classificação , Bactérias Gram-Positivas/classificação , Reação em Cadeia da Polimerase em Tempo Real/métodos , Cárie Radicular/microbiologia , Actinomyces/isolamento & purificação , Actinomycetaceae/isolamento & purificação , Anti-Infecciosos Locais/uso terapêutico , Carga Bacteriana , Clorexidina/análogos & derivados , Clorexidina/uso terapêutico , Periodontite Crônica/microbiologia , Periodontite Crônica/terapia , Sondas de DNA , Placa Dentária/microbiologia , Raspagem Dentária , Feminino , Humanos , Lactobacillus/isolamento & purificação , Masculino , Pessoa de Meia-Idade , Neisseria mucosa/isolamento & purificação , Peptostreptococcus/isolamento & purificação , Propionibacterium acnes/isolamento & purificação , Aplainamento Radicular , Streptococcus mutans/isolamento & purificação , Streptococcus sobrinus/isolamento & purificação , Taq Polimerase , Raiz Dentária/microbiologia , Veillonella/isolamento & purificaçãoRESUMO
The purpose of the present study was to describe the bacterial diversity in the oral cavity of the elderly without root caries using bacterial microarrays, and to determine the site- and subject-specificity of bacterial colonization. Samples were collected from the tongue dorsum, mucosa of the buccal fold, hard palate, supragingival plaque from sound root surfaces, and subgingival plaque from the same roots. A new 16 S rRNA gene-based microarray method was used for the simultaneous detection of approximately 300 bacterial species. Overall, 175 species and clusters were detected, representing eight phyla. Species belonging to the genera Streptococcus, Veillonella, and Fusobacterium were common in all sites. The number of species per subject varied from 51 to 81. Statistical analyses revealed about 40 species or clusters with significant associations with at least one of the sites. The bacterial diversity was highest in the cheek and palate regions. Species typically associated with caries and periodontitis were detected rarely or not at all. The oral bacterial flora of the elderly appears to be diverse, and, to a large extent, site- rather than subject-specific.
Assuntos
Bactérias/classificação , Bactérias/isolamento & purificação , Biodiversidade , Boca/microbiologia , Idoso , Idoso de 80 Anos ou mais , Bactérias/genética , DNA Bacteriano/genética , DNA Ribossômico/genética , Feminino , Humanos , Masculino , Análise em Microsséries , Sondas de Oligonucleotídeos/genética , RNA Ribossômico 16S/genéticaRESUMO
The present study used a new 16S rRNA-based microarray with probes for over 300 bacterial species to better define the bacterial profiles of healthy root surfaces and root caries (RC) in the elderly. Supragingival plaque was collected from 20 healthy subjects (Controls) and from healthy and carious roots and carious dentin from 21 RC subjects (Patients). Collectively, 179 bacterial species and species groups were detected. A higher bacterial diversity was observed in Controls than in Patients. Lactobacillus casei/paracasei/rhamnosus and Pseudoramibacter alactolyticus were notably associated with most RC samples. Streptococcus mutans was detected more frequently in the infected dentin than in the other samples, but the difference was not significant. Actinomyces was found more frequently in Controls. Thus, species other than Actinomyces and S. mutans may play a role as pathogens of RC. The results from this study were in general agreement with those of our previous study based on 16S rRNA gene sequencing.
Assuntos
Biodiversidade , Bactérias Gram-Positivas/classificação , Bactérias Gram-Positivas/genética , Análise em Microsséries , Cárie Radicular/microbiologia , Idoso , Idoso de 80 Anos ou mais , Análise por Conglomerados , DNA Bacteriano/genética , DNA Ribossômico/genética , Feminino , Bactérias Gram-Positivas/isolamento & purificação , Humanos , Masculino , RNA Ribossômico 16S/genéticaRESUMO
Acute toxicity tests, exposing Girardia tigrina to potassium dichromate (K(2)Cr(2)O(7)), showed good reproducibility. The 95% confidence intervals among tests were 0.0262+/-0.0141 g for 48-h LC(50) (N=6) and 0.0129+/-0.0078 g for 96-h LC(50) (N=5). The 96-h LC(50) for G. tigrina was below that of oligochaetes and above that of cladocera.
