title: Molecular identification of an Enterococcus faecalis endocarditis antigen efaA in root canals of therapy-resistant endodontic infections.
abstract: BACKGROUND
  Enterococcus faecalis has long been implicated in persistent root canal infections and therapy-resistant endodontic infections. It has also been associated with bacteremia, that is, infective endocarditis arising from certain invasive dental procedures. E. faecalis endocarditis antigen (efaA) has been identified as one of the principal virulence factors associated with infective endocarditis.
  
  
  OBJECTIVE
  To detect the presence of putative E. faecalis virulence factor, efaA in root canals of therapy-resistant endodontic infections using polymerase chain reaction (PCR) amplification.
  
  
  METHODS
  Samples were obtained from 32 patients (20-70 years) undergoing endodontic retreatment, which were incubated in prereduced thioglycollate broth and subcultured onto ethyl violet azide broth (EVA; selective medium for E. faecalis). Deoxyribonucleic acid (DNA) was extracted from the samples and analyzed for the endocarditis virulence factor efaA using PCR.
  
  
  RESULTS
  Among the positive E. faecalis samples, efaA gene was identified in 11 out of 15 samples.
  
  
  CONCLUSIONS
  Our findings indicate that efaA, a potent E. faecalis virulence gene can be found in E. faecalis strains detected in root canals of therapy-resistant endodontic infections similar to reports for 'medical' strains.
authors.affiliation: Department of Conservative Dentistry and Endodontics, Amrita School of Dentistry, Kochi, Kerala, India.
authors.forename: Thomas
authors.initials: T
authors.lastname: Preethee
authors.forename: Deivanayagam
authors.initials: D
authors.lastname: Kandaswamy
authors.forename: Rosaline
authors.initials: R
authors.lastname: Hannah
keywords: Enterococcus faecalis endocarditis antigen; infective endocarditis; polymerase chain reaction