Characterization of virulence factors and clonal diversity of Enterococcus faecalis isolates from treated dental root canals.
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.
Institute of Microbiology Prof Paulo de Góes, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil.
Gustavo O
GO
Zoletti
Eliezer M
EM
Pereira
Ricardo P
RP
Schuenck
Lúcia M
LM
Teixeira
José F
JF
Siqueira
Kátia Regina N
KR
dos Santos
D000328:Adult; D000368:Aged; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism; D003786:Dental Pulp Cavity / Q000382:microbiology*; D016521:Electrophoresis, Gel, Pulsed-Field; D013293:Enterococcus faecalis / Q000145:classification / Q000235:genetics* / Q000302:isolation & purification / Q000472:pathogenicity*; D005260:Female; D018093:Gelatinases / Q000235:genetics; D014644:Genetic Variation; D016908:Gram-Positive Bacterial Infections / Q000382:microbiology; D006801:Humans; D008297:Male; D008565:Membrane Proteins / Q000235:genetics / Q000378:metabolism; D008875:Middle Aged; D010485:Periapical Periodontitis / Q000382:microbiology; D016133:Polymerase Chain Reaction; D014070:Tooth / Q000382:microbiology; D014774:Virulence / Q000235:genetics; D037521:Virulence Factors / Q000235:genetics*; D055815:Young Adult
D001426:Bacterial Proteins; D008565:Membrane Proteins; D037521:Virulence Factors; C116707:enterococcal surface protein, esp; D018093:Gelatinases