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Actinomyces species, streptococci, and Enterococcus faecalis in primary root canal infections
José F Siqueira1, Isabela N Rôças, Renata Souto
1Oral Microbiology Laboratory, Institute of Microbiology, Federal University of Rio de Janeiro, RJ, Brazil.
Abstract:
The purpose of this study was to evaluate the prevalence of Actinomyces species, streptococci, and Enterococcus faecalis in primary root canal infections by using a molecular genetic method. Samples were obtained from 53 infected teeth, of which 27 cases were diagnosed as acute periradicular abscesses. DNA was extracted to evaluate the occurrence of 13 bacterial species by using whole genomic DNA probes and checkerboard DNA-DNA hybridization. Polymerase chain reaction using an ubiquitous bacterial primer was undertaken to check the presence of bacterial DNA in clinical samples. All root canal samples contained bacteria as demonstrated by polymerase chain reaction. The checkerboard DNA-DNA hybridization assay allowed the detection of streptococci in 22.6% of the samples, Actinomyces species in 9.4%, and E. faecalis in 7.5%. The most prevalent species were members of the Streptococcus anginosus group. With regard to the asymptomatic lesions, the most prevalent species were S. intermedius (11.5% of the cases), E. faecalis (11.5%), and S. anginosus (7.7%). S. constellatus was the most prevalent species in pus samples (25.9% of the cases). The other most prevalent species in abscessed teeth were A. gerencseriae (14.8%), S. gordonii (11.1%), S. intermedius (11.1%), A. israelii (7.4%), S. anginosus (7.4%), and S. sanguis (7.4%). S. constellatus was the only species positively associated with acute periradicular abscess (p < 0.01).
Insights
This study identified key bacteria in root canal infections using molecular methods. Streptococcus constellatus was significantly linked to acute periradicular abscesses.
Area of Science:
- Microbiology
- Molecular Biology
- Dentistry
Background:
- Primary root canal infections harbor diverse bacterial communities.
- Accurate identification of these bacteria is crucial for effective treatment.
Purpose of the Study:
- To determine the prevalence of Actinomyces species, streptococci, and Enterococcus faecalis in primary root canal infections.
- To utilize molecular genetic methods for precise bacterial detection.
Main Methods:
- Collected samples from 53 infected teeth, including 27 acute periradicular abscesses.
- Employed checkerboard DNA-DNA hybridization and polymerase chain reaction (PCR) for bacterial identification.
- Analyzed DNA from 13 bacterial species using whole genomic DNA probes.
Main Results:
- All samples tested positive for bacterial DNA via PCR.
- Streptococci were found in 22.6%, Actinomyces in 9.4%, and E. faecalis in 7.5% of samples.
- Streptococcus constellatus was the only species significantly associated with acute periradicular abscesses (p < 0.01).
Conclusions:
- Molecular methods provide accurate insights into the microbial landscape of root canal infections.
- Specific bacterial species, like S. constellatus, may serve as indicators for acute periradicular abscesses.