Identification of microorganisms in persistent/secondary endodontic infections with respect to clinical and radiographic findings: bacterial culture and molecular detection

Abstract

Background and Objectives: Bacterial agents are commonly accepted as the main etiology of endodontic infections. A significant proportion of oral bacteria cannot be cultured using existing methods. Since diversity and abundance of bacterial species are different in different populations, the present study was aimed to identify effective microorganisms in persistent endodontic infections in Iranian patients based on culture and molecular biology methods using sequence analysis of 16S rDNA gene.
 Materials and Methods: Thirty patients with previous failure of endodontic treatment were enrolled in the study. After isolation and disinfection of the tooth surrounding area with 3% sodium hypochlorite and 30% hydrogen peroxide, sampling from the root canals was carried out using two sterile Hedstrom files and two sterile paper points, and then the specimens were transferred to the microbiology laboratory in thioglycolate transport medium so that they undergo aerobic-anaerobic culture, PCR, and 16S rDNA gene sequencing.
 Results: Of 30 patients (15 women and 15 men), 15 patients had radiographic lesions smaller than 5 mm and other 15 pa- tients had radiographic lesions larger than 5 mm. The mean age of patients was 40.20 ± 13.76 years. A total of 26 patients were asymptomatic. Only four patients had clinical signs such as pain and percussion sensitivity and Tannerella forsythia was the most common bacterium found in this group of patients. 13 bacterial species were found in 11 different genus, one virus strain and one fungus strain. From 30 studied specimens, Enterococcus faecalis was the most common microorganism with prevalence rate of 63.63%.
 Conclusion: This study showed the type and prevalence of effective bacteria in secondary/persistent endodontic infections in Iranian patients. E. faecalis is the most commonly found microorganism in Iranian patients

Bacteria Residing at Root Canals Can Induce Cell Proliferation and Alter the Mechanical Properties of Gingival and Cancer Cells

“…Candida albicans is the most common prevalent fungus in the root canals of infected teeth. Recent studies have also proved the role of viruses such as Cytomegalovirus (CMV) and Epstein–Barr virus (EBV) in symptomatic periapical lesions [ 39 , 40 ].…”

Quantification of Bacterial Colonization in Dental Hard Tissues Using Optimized Molecular Biological Methods

“…In our study, we used E. faecalis as a model organism since it is the most common bacterial species recovered in secondary apical periodontitis (Zargar et al, 2019). Although not shown in this manuscript, the same approach should also work for other Grampositive or Gram-negative bacteria.…”

Detection of Genes Related to Resistance to Silver Nanoparticles in Bacteria from Secondary Endodontic Infections

“…Many studies have only focused on detecting the presence of resistance genes in different oral environments, including bacteria isolated from different types of endodontic infections [35,36]. Other studies have only been dedicated to associate the presence of certain bacterial species with the presence of clinical symptoms [37]. The only study similar to ours that we found during the review of the literature is that of De Lima et al In this study, the authors only analyzed the association between the presence of lactamic resistance genes (blaTEM) and clinical parameters (pulpal diagnosis, sinus tract, pain, and swelling); but they found no association between these variables [38].…”