RESUMO
AIM: To evaluate the presence of bacteria in permanent teeth with intact crowns (without caries, periodontal disease or dental trauma) in patients with sickle cell anaemia (HbSS genotype) by analysing their clinical, imaging and microbiological parameters. METHODOLOGY: This is a case series study nested in a cohort. In the first follow-up of this cohort study (Journal of Endodontics, 2013, 39, 177), 10 HbSS patients with at least one tooth with an intact crown and clinically diagnosed with pulp necrosis by pulse oximetry adapted for dentistry and a cold pulp sensitivity test (n = 27 teeth) were selected. Changes in the pulp chamber, root and periodontal ligament were identified in the tomographic analysis. Bacterial culture, staining for live and dead bacteria, and real-time polymerase chain reaction with 16S rRNA primers were used to identify the presence of bacteria. Culture sample collection was performed immediately after access to the pulp chamber. The microbiome was analysed with a MiSeq sequencer (Illumina, San Diego, CA). RESULTS: The diagnosis of pulp necrosis was confirmed clinically in 82% (22/27) of the teeth. The amount of bacterial load identified was less than 100 copies µL-1 in 23% (5/22) of the teeth with intact crowns and pulp necrosis. Thirteen bacterial species were identified that are commonly found in urinary tract infections, septicaemia and infective endocarditis. Only one of these species, Granulicatella adjacens, has also be found in primary endodontic infections. CONCLUSION: Prospective clinical, imaging and microbiological analyses suggest that pulp necrosis of teeth with intact crowns in HbSS patients is not associated with the presence of bacteria.
Assuntos
Anemia Falciforme , Infecções Bacterianas , Estudos de Coortes , Coroas , Polpa Dentária , Necrose da Polpa Dentária , Humanos , Estudos Prospectivos , RNA Ribossômico 16SRESUMO
The relationship between clinical characteristics of carious dentin and bacterial colonization after partial caries removal is not completely understood. The aim of this study was to compare microbial counts between categories of carious dentin color, consistency and humidity, and to evaluate the correlation between these characteristics and the presence of cariogenic microorganisms in deep cavities (2/3 or more of the dentin thickness) submitted to partial caries removal. Sixteen primary teeth were submitted to the removal of all carious tissue from the lateral walls of the cavity, whereas carious tissue of the pulp wall was removed superficially. Dentin in the pulp wall was classified according to color, consistency and humidity immediately after cavity preparation and 3-6 months after cavity sealing and a tissue sample was collected on the same occasion for microbiological evaluation. Before sealing, Streptococcus mutans (p = 0.033) and Lactobacillus spp. (p = 0.048) counts were higher in cavities with humid dentin compared to cavities with dry dentin. A negative correlation was observed between carious dentin consistency and S. mutans count during this phase (r(s) = -0.571; p = 0.020). Arrest of dentinal caries lesions was observed after sealing, which was characterized by a reduction of bacterial counts and changes in dentin color, consistency and humidity, irrespectively of baseline dentin characteristics. The clinical characteristics of carious dentin change after the period of cavity sealing and cannot be applied as absolute indicators to limit the excavation of carious dentin when minimally invasive techniques are used.
Assuntos
Cárie Dentária/terapia , Preparo da Cavidade Dentária/métodos , Dentina/microbiologia , Dente Decíduo/microbiologia , Carga Bacteriana , Bis-Fenol A-Glicidil Metacrilato/química , Hidróxido de Cálcio/uso terapêutico , Criança , Pré-Escolar , Cor , Resinas Compostas/química , Cárie Dentária/microbiologia , Polpa Dentária/microbiologia , Polpa Dentária/patologia , Restauração Dentária Permanente/métodos , Dentina/patologia , Adesivos Dentinários/química , Seguimentos , Humanos , Umidade , Lactobacillus/crescimento & desenvolvimento , Minerais/uso terapêutico , Dente Molar/microbiologia , Dente Molar/patologia , Agentes de Capeamento da Polpa Dentária e Pulpectomia/uso terapêutico , Streptococcus mutans/crescimento & desenvolvimento , Dente Decíduo/patologiaRESUMO
Since viable bacteria can persist in tooth cavities regardless of the technique used for caries removal, the objective of the present randomized clinical trial was to examine the microflora of primary teeth treated by complete or partial removal of carious dentin. Deciduous molars with acute carious lesions in the inner half of dentin and vital pulp were randomly divided into two groups of 16: complete removal, in which the carious dentin was completely removed with the help of a caries detector dye, and partial removal, in which the carious dentin was completely removed from the dentinoenamel junction and lateral walls, while the necrotic carious dentin from the cavity floor was only removed superficially. Dentin samples were obtained with a sterile No. 3 bur after caries removal and 3-6 months after protection with calcium hydroxide cement and restoration of the cavities with resin composite. The samples were stored in thioglycolate. Decimal dilutions were then prepared and seeded for the enumeration of Streptococcus spp., mutans streptococci, Lactobacillus spp. and total microorganisms. Before sealing, a larger number of microorganisms was detected in teeth submitted to partial caries removal compared to the complete removal group. However, after sealing the level of colonization was similar in the two groups for all microorganisms studied. The results suggest that persistence of bacteria does not seem to be a reason for reopening of cavities in deciduous teeth after partial caries removal.
Assuntos
Cárie Dentária/microbiologia , Preparo da Cavidade Dentária/métodos , Restauração Dentária Permanente/métodos , Dentina/microbiologia , Camada de Esfregaço , Hidróxido de Cálcio/uso terapêutico , Criança , Pré-Escolar , Contagem de Colônia Microbiana , Resinas Compostas/uso terapêutico , Cárie Dentária/patologia , Cárie Dentária/terapia , Forramento da Cavidade Dentária , Cimentos Dentários/uso terapêutico , Dentina/patologia , Humanos , Lactobacillus/isolamento & purificação , Estudos Longitudinais , Dente Molar , Streptococcus/isolamento & purificação , Dente DecíduoRESUMO
A total of 398 diffusely adhering Escherichia coli (DAEC) strains of fecal origin were analyzed for the presence of sequences homologous to the structural subunit gene (daaE) of the F1845 fimbria. For that purpose, a DNA fragment homologous to daaE, obtained by PCR, was used as a probe in colony hybridization assays. Only two strains carried daaE and expressed F1845, suggesting that this fimbria is rare among DAEC strains.
Assuntos
Adesinas de Escherichia coli/genética , Antígenos de Bactérias , Proteínas de Bactérias/genética , Diarreia/microbiologia , Infecções por Escherichia coli/microbiologia , Proteínas de Escherichia coli , Escherichia coli/genética , Proteínas de Fímbrias , Adesinas de Escherichia coli/biossíntese , Proteínas de Bactérias/biossíntese , Pré-Escolar , Fezes/microbiologia , Expressão Gênica , Células HeLa , Humanos , LactenteRESUMO
Seventeen Escherichia coli O111:H12 strains isolated from the feces of children with acute diarrhea were studied with regard to their adherence properties and other virulence characteristics. All strains showed an aggregative adherence pattern to HEp-2 cells and agglutinated bovine and sheep red cells in the presence of mannose. These strains did not have gene sequences homologous to the aggregative adherence fimbria I gene and did not react with any of the DNA probes used to detect other virulence genes in enteropathogens. With one exception, the O111:H12 strains did not induce fluid accumulation in the rabbit ileal loop assay, although 16 of the strains had the enteroaggregative E. coli heat-stable enterotoxin 1 (EAST) gene sequences. A 60-70 MDa plasmid was present in 16 of the strains studied. We conclude that the O111:H12 serotype, one of the first E. coli identified in infantile diarrhea, belongs to the enteroaggregative E. coli category but the genes encoding its adherence phenotype are distinct from those previously described.