Susceptibility of As-yet-uncultivated and Difficult-to-culture Bacteria to Chemomechanical Procedures
| Autor: | Mônica A.S. Neves, José C. Provenzano, Isabela N. Rôças, José F. Siqueira |
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| Rok vydání: | 2014 |
| Předmět: |
DNA
Bacterial Bacteroidaceae Sodium Hypochlorite Megasphaera Polymerase Chain Reaction law.invention Microbiology chemistry.chemical_compound Nickel law Molecular microbiology Dental Pulp Necrosis medicine Humans Microbiome General Dentistry Polymerase chain reaction Titanium Periodontitis Bacteriological Techniques Gram-Negative Anaerobic Bacteria Bacteria Root Canal Irrigants biology Microbiota Equipment Design Ribosomal RNA medicine.disease biology.organism_classification Bacterial Load Phenotype chemistry Sodium hypochlorite Dental Pulp Cavity Periapical Periodontitis Root Canal Preparation Dental Alloys |
| Zdroj: | Journal of Endodontics. 40:33-37 |
| ISSN: | 0099-2399 |
| Popis: | Introduction A significant portion of the bacteria taking part of the microbiome associated with apical periodontitis still remain to be cultivated and phenotypically characterized. This molecular study evaluated the prevalence of selected as-yet-uncultivated and difficult-to-culture bacterial taxa in infected root canals and their susceptibility to chemomechanical procedures. Methods Root canals of single-rooted teeth with apical periodontitis were prepared using rotary nickel-titanium instruments and 2.5% sodium hypochlorite as the irrigant. DNA extracts from samples taken before (S1) and after (S2) chemomechanical preparation were surveyed for the presence of 7 as-yet-uncultivated phylotypes and 1 difficult-to-culture species using end-point polymerase chain reaction. Samples were also subjected to quantitative analysis of total bacteria and levels of the 2 most prevalent taxa. Results Bacteroidaceae sp. HOT-272 (24%) and Fretibacterium fastidiosum (20%) were the most prevalent taxa in S1. Their mean counts in S1 were 8.25 × 103 and 2.13 × 103 rRNA gene copies, corresponding to 0.18% and 0.55% of the total bacteria. Chemomechanical debridement promoted a highly statistically significant reduction in total bacterial counts (P < .001), but 64% of the canals were still positive for bacterial presence. Of the target taxa, only Bacteroidaceae sp. HOT-272 and F. fastidiosum were detected in S2 (each one in 1 sample). The reduction in counts of both taxa was also highly significant (P < .001). Conclusions Findings confirmed that several as-yet-uncultivated and difficult-to-grow bacterial taxa can participate in the microbiome associated with apical periodontitis. Two of them were found in relatively high prevalence but rarely as a dominant species. Chemomechanical procedures were highly effective in completely eliminating these taxa or at least substantially reducing their numbers. |
| Databáze: | OpenAIRE |
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