Capsule Locus Polymorphism among Distinct Lineages of Enterococcus faecalis Isolated from Canals of Root-filled Teeth with Periapical Lesions (original) (raw)

Analysis of Genetic Lineages and Their Correlation with Virulence Genes in Enterococcus faecalis Clinical Isolates from Root Canal and Systemic Infections

Journal of Endodontics, 2013

Introduction: Enterococcus faecalis is a member of the mammalian gastrointestinal microbiota but has been considered a leading cause of hospital-acquired infections. In the oral cavity, it is commonly detected from root canals of teeth with failed endodontic treatment. However, little is known about the virulence and genetic relatedness among E. faecalis isolates from different clinical sources. This study compared the presence of enterococcal virulence factors among root canal strains and clinical isolates from hospitalized patients to identify virulent clusters of E. faecalis. Methods: Multilocus sequence typing analysis was used to determine genetic lineages of 40 E. faecalis clinical isolates from different sources. Virulence clusters were determined by evaluating capsule (cps) locus polymorphisms, pathogenicity island gene content, and antibiotic resistance genes by polymerase chain reaction. Results: The clinical isolates from hospitalized patients formed a phylogenetically separate group and were mostly grouped in the clonal complex 2, which is a known virulent cluster of E. faecalis that has caused infection outbreaks globally. The clonal complex 2 group comprised capsule-producing strains harboring multiple antibiotic resistance and pathogenicity island genes. On the other hand, the endodontic isolates were more diverse and harbored few virulence and antibiotic resistance genes. In particular, although more closely related to isolates from hospitalized patients, capsuleproducing E. faecalis strains from root canals did not carry more virulence/antibiotic genes than other endodontic isolates. Conclusions: E. faecalis isolates from endodontic infections have a genetic and virulence profile different from pathogenic clusters of hospitalized patients' isolates, which is most likely due to niche specialization conferred mainly by variable regions in the genome. (J Endod 2013;39:858-864)

Virulence Genes, Antibiotic Resistance and Capsule Locus Polymorphisms in Enterococcus faecalis isolated from Canals of Root-Filled Teeth with Periapical Lesions

Infection & Chemotherapy, 2018

Frequent isolation of Enterococcus faecalis from root canal treated teeth with apical periodontitis, has proposed the role of this organism in endodontic treatment failures. Different factors have been suggested in the pathogenicity of this organism. In this study, 22 E. faecalis isolates from canals of root-filled teeth were identified, and phenotypic and genotypic characteristics were investigated. No resistance to vancomycin and gentamicin was noted, and most isolates (91%) were susceptible to ampicillin. Biofilm formation was detected in 73% of the isolates and may be considered as the most important virulence factor involved in the pathogenesis of these isolates.

Phenotype and Genotype of Enterococcus faecalis Isolated form Root Canal and Saliva of Primary Endodontic Patients

Journal of Dentistry Indonesia, 2016

Objective: To investigate the phenotype and genotype of E. faecalis isolated from the root canal and saliva of primary endodontic patients with periapical lesions. Methods: Eighteen adult male and female individuals suffering from primary endodontic infection, either with or without periapical lesions, were involved in this study. Root canal scraping and saliva were collected from each subject and used for bacterial quantitation using a real-time polymerase chain reaction (RT-PCR). Enterococci were isolated using ChromAgar medium and then identified using both biochemical (Gram staining and catalase tests) and molecular biology (conventional PCR) methods. Gelatinase activity, polysaccharide capsul profile and mRNA ace expression level were determined using microbiological, biochemical and molecular biology approach, respectively. Genotype of E. faecalis was determined based on nucleotide sequence of ace and gelE genes analyzed using web-based 3730xl DNA Analyze software. Results: The results showed that except for its proportion, no significant difference was found in phenotypes (gelatinase activity and mRNA ace expression levels) and genotypes (polymorphism of Cps operon and variation of ace and gelE nucleotide sequences) of E. faecalis isolated from the root canal and saliva of primary endodontic patients had or had no periapical lesions. Conclusion: It can be concluded that E. faecalis proportion had a role in the occurrence of periapical lesions in the primary endodontic patients, but not gelatinase activity, mRNA ace expression level, Cps operon polymorphism or ace and gelE nucleotide sequence variations.

Characterization of virulence factors and clonal diversity of Enterococcus faecalis isolates from treated dental root canals

Research in Microbiology, 2011

The high prevalence of Enterococcus faecalis in root canal treated teeth with post-treatment disease, as evidenced by both molecular and traditional culturing methods, suggests that this species may be a key player in endodontic treatment failure. This study aimed to detect virulence factors by phenotypic and western blotting tests, and virulence genes by PCR from 20 clinical strains of E. faecalis isolated from treated root canals of teeth with (10) or without (10) apical periodontitis. Moreover, genomic diversity of these strains was assessed by pulsed-field gel electrophoresis (PFGE) and rep-PCR. All 20 strains presented the gelE gene (gelatinase), but 10 of them did not hydrolyze gelatin. Seven of the 10 gelatinase-producing isolates were recovered from root canals with lesions, which suggests a role for this virulence factor in the pathogenesis of post-treatment disease. The esp gene was expressed only in cases where gelatinase production was negative. The other virulence genes were found in 90% (efaA and ace genes), 45% (agg gene) and 95% (cpd gene) of the E. faecalis isolates. As for PFGE and rep-PCR, no specific clonal type of E. faecalis was found in association with teeth with or without disease, revealing the interindividual clonal diversity of endodontic infections.

Virulence genes in biofilm producer Enterococcus faecalis isolates from root canal infections

Cellular and Molecular Biology, 2017

Enterococcus faecalis is occurring in opportunistic infections involving the oral cavity. This study aimed to evaluate the presence of E. faecalis virulence genes in dental root canal isolates recovered from advanced chronic periodontitis patients. One hundred E. faecalis isolated from dental root canal during July 2015 to Oct 2016. After analysis of biofilm formation by the semi-quantitative determination in 96-well flat bottom polystyrene plates, the presence of asa, esp, efaA, ace, ebpR, gel and hyl gene were studied by PCR. Gelatinase and hemolytic activity were detected by phenotypic methods. Ninety-one percent of isolates had ebpR gene, 85% ace, 82% efaA, 81% gel, 56% esp, 33% asa1, 2% hyl and 0% cyl gene. Evaluation of biofilm formation by microtiter plate method presented 49% of the isolates as strong biofilm producer, 42% displayed moderate biofilm formation, and 10 % weak or no biofilm was observed. asa1, efaA, esp, and ebpR positive isolates had significantly higher biofilm formation than negative isolates, while no significant differences were found when comparing ace-positive andnegative isolates. Present study showed that the ace genes do not seem to be necessary nor sufficient for the production of biofilm in Enterococcus faecalis but the presence of asa1, efaA, esp, and ebpR correlates with increased biofilm formation of dental root canal isolates.

Molecular Typing of Enterococcus faecalis from Persistent Endodontic Infections

International journal of odontostomatology, 2018

Molecular techniques that provide valuable information about the epidemiology of oral strains. The purpose of this study was to determine the genetic relatedness of 83 Enterococcus faecalis strains isolated from treated root canals. These strains were obtained from patients who were treated for persistent endodontic infections. E. faecalis isolates were molecular typed by Pulsed Field Gel Electrophoresis using SmaI. Ten clonal groups and 13 pulse types with 38.7 % similarity for the less related strains were identified. Genetic heterogeneity among strains from different patients and a high level of genetic homogeneity among intrapatient strains were observed. Therefore, restriction endonuclease fingerprinting of genomic DNA from E. faecalis strains confirmed the polyclonality of the isolates obtained from the root canals of patients diagnosed with persistent endodontic infections, compared with other reports. These results provide additional data for a better understanding of the epidemiological aspects of root canal infections by E. faecalis.

Clonal diversity and antimicrobial resistance of Enterococcus faecalis isolated from endodontic infections

Electronic Journal of Biotechnology, 2015

Background: Enterococcus faecalis is considered to be one of most prevalent species in the oral cavity, particularly in endodontic infections. The aim of the present study was to investigate the prevalence of E. faecalis in dental root canals, clonal diversity by restriction fragment length polymorphism (RFLP) and randomly amplified polymorphic DNA (RAPD-PCR) analysis, and the antibiotic susceptibility of E. faecalis isolates. Results: Among the bacterial strains isolated from dental root canal specimens (n = 82), E. faecalis was determined to have the highest prevalence followed by Streptococcus viridians, Leuconostoc mesenteroides, Staphylococcus aureus, Streptococcus mitis, and Pediococcus pentosaceus. Cluster analysis of RAPD-PCR and RFLP patterns of the E. faecalis isolates discriminated five and six different genotypes, respectively. Among the tested strains, 43%, 52% and 5% were susceptible, intermediate resistant, and resistant to erythromycin, respectively. In addition, one strain (E-12) was intermediate resistant to linezolid, and one isolate (E-16) was resistant to tetracycline. Interestingly, many of the intermediate resistant/resistant strains were grouped in clusters 5 and 6, according RAPD and to RFLP, respectively. Conclusions: E. faecalis demonstrated the highest prevalence in the tested dental root canal specimens collected from Saudi patients and were grouped into five to six different genotypes. Different levels of antimicrobial susceptibility were observed in the tested E. faecalis strains, which clearly indicated that although bacterial strains may be similar, point mutations can result in extreme susceptibility or resistance to various antibiotics. This phenomenon is a cause for concern for clinicians in the treatment of dental infections caused by E. faecalis.

Molecular detection of E. faecalis in oral samples of a population associated with secondary endodontic infection

International Dental Research, 2021

Aim: The objective of this study was to evaluate the prevalence of Enterococcus faecalis in samples of oral rinse and tongue dorsum of endodontic patients with secondary/persistent infections (EPSI) using the PCR method. Methodology: Oral rinse samples (ORS) and tongue swab samples (TSS) of 22 patients (EPSI group) and 32 healthy individuals (control group) were collected. DNA isolation from the TSS and ORS samples was performed using the modified classical phenol-chloroform and chloroform method. To detect E. faecalis strains directly from the TSS and ORS samples, the 310 base pair (bp) segment of the 16S rDNA of the E. faecalis genome was amplified by PCR using specific primers. The prevalence of E. faecalis was compared between healthy and sick individuals using the Chi-square test, significance was set at p<0.05. Results: In the ORS samples, there was a significant difference between the healthy individuals (n = 11, 34%) and the EPSI group (n = 15, 68%) in terms of the presen...

Phenotypic Detection of Virulence Traits and Antibiotic Susceptibility of Endodontic Enterococcus faecalis Isolates

American Journal of Microbiological Research, 2013

Enterococcus faecalis is a Gram-positive member of human gastrointestinal flora that is in recent years emerging as an important cause of endodontic infections. In this study, we have investigated the occurrence of virulence determinants and antibiotic susceptibility pattern of E. faecalis isolates, originating from root canals of apical periodontitis. Among 52 E. faecalis isolates, 32 (61.5%) isolates produced hemolysin on blood agar while all (100%) isolates showed hemolysin production on BHI-GA ((BHI medium supplemented with 1% glucose and 0.03% L-arginine), 18 (34.6%) produced gelatinase, 38 (73%) produced caseinase, no hemagglutination was observed in E. faecalis isolates, whereas all 52 (100%) resistant to serum and formed biofilm. Antibiotic susceptibility results showed that all (100%) E. faecalis isolates were susceptible to amoxicillin, amoxicillin/clavulanate, and vancomycin. Whereas, 32 (61.5%) E. faecalis isolates were resistant to chloramphenicol, 30 (57.6%) isolates were resistant to ciprofloxacin, 39 (75%) isolates were resistant to erythromycin, and 34 (65.3%) isolates were resistant to tetracycline. Multi-drug resistance was observed in 16 (30.7%) isolates of E. faecalis to chloramphenicol, ciprofloxacin, erythromycin and tetracycline antibiotics. These findings demonstrate the presence of putative virulence determinants in E. faecalis isolates originating from root canal and suggest amoxicillin, amoxicillin/clavulanate, and vancomycin as more effective than other antibiotics tested.

Identification of Enterococcus faecalis in root-filled teeth with or without periradicular lesions by culture-dependent and-independent approaches

Journal of endodontics, 2006

Enterococcus faecalis is the most commonly found species in root-filled teeth evincing recalcitrant periradicular lesions and as a consequence, a role in causation of endodontic treatment failure has been suggested. The purpose of this study was to evaluate the prevalence of this bacterial species in root-filled teeth with or without periradicular lesions. Identification of E. faecalis was carried out by polymerase chain reaction (PCR) or conventional culture procedures. Overall, E. faecalis was detected by species-specific 16S rRNA gene-based PCR in 40/50 teeth (80%), while culture revealed the occurrence of this species in 8/50 teeth (16%). PCR was significantly more effective than culture in detecting this bacterial species (p < 0.001). Of 27 root-filled teeth with no periradicular lesions, E. faecalis was found in 22 cases (81.5%) by PCR and in five cases (18.5%) by culture. Of 23 root-filled teeth with periradicular lesions, E. faecalis was identified in 18 cases (78%) by PC...