title: Capsule locus polymorphism among distinct lineages of Enterococcus faecalis isolated from canals of root-filled teeth with periapical lesions.
abstract: BACKGROUND
  Although Enterococcus faecalis is a member of the normal microbiota, it is also a major cause of nosocomial infections. Some strains of E. faecalis produce capsule, which contributes to pathogenesis through evasion of host defenses, and its production is dependent on the capsule (cps) operon polymorphism. This study investigated cps locus polymorphism in distinct lineages of E. faecalis isolated from canals of root-filled teeth with periapical lesions.
  
  
  METHODS
  Twenty-two E. faecalis isolates were evaluated regarding the cps operon polymorphism and genetic diversity. The 3 known CPS types were determined by polymerase chain reaction. This information was correlated with multilocus sequence typing data, which were used to define genetic lineages.
  
  
  RESULTS
  cpsA and cpsB were the only detected genes within the cps operon in 62.5% of E. faecalis strains (14/22), indicative of genotype CPS 1, which lacks capsule expression. The essential genes in the cps operon for capsule production were detected in the remaining strains, whereas 3 belonged to genotype CPS 5 and 5 strains to genotype CPS 2. A total of 14 sequence types (STs) were resolved in 22 E. faecalis isolates. Comparison with the E. faecalis international multilocus sequence typing database revealed that 9 STs were previously found, and that the 5 STs were novel.
  
  
  CONCLUSIONS
  Certain E. faecalis genotypes from canals of root-filled teeth with periapical lesions belong to lineages associated with capsule expression and production of multiple virulence factors, which might account for their increased pathogenic potential.
authors.affiliation: Department of Microbiology, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil. erickapinheiro@yahoo.com.br
authors.forename: Ericka T
authors.initials: ET
authors.lastname: Pinheiro
authors.forename: Pâmela P
authors.initials: PP
authors.lastname: Penas
authors.forename: Marcos
authors.initials: M
authors.lastname: Endo
authors.forename: Brenda P F A
authors.initials: BP
authors.lastname: Gomes
authors.forename: Marcia P A
authors.initials: MP
authors.lastname: Mayer
mesh_terms: D016667:Bacterial Capsules / Q000235:genetics*; D001426:Bacterial Proteins / Q000235:genetics; D015373:Bacterial Typing Techniques; D003786:Dental Pulp Cavity / Q000382:microbiology*; D013293:Enterococcus faecalis / Q000145:classification / Q000235:genetics* / Q000472:pathogenicity; D056426:Genetic Loci / Q000235:genetics*; D014644:Genetic Variation / Q000235:genetics; D005838:Genotype; D006801:Humans; D058885:Multilocus Sequence Typing; D009876:Operon / Q000235:genetics; D010483:Periapical Diseases / Q000382:microbiology*; D016133:Polymerase Chain Reaction; D011110:Polymorphism, Genetic / Q000235:genetics*; D019553:Tooth, Nonvital / Q000382:microbiology*; D037521:Virulence Factors / Q000235:genetics
chemical_list: D001426:Bacterial Proteins; D037521:Virulence Factors