title: Characterization of Streptococcus constellatus strains recovered from a brain abscess and periodontal pockets in an immunocompromised patient.
abstract: BACKGROUND
  There have been a number of reports of brain abscesses suggesting an odontogenic etiology. However, no efforts have been made to compare brain abscess isolates with isolates from the oral cavity using highly discriminative methods. We report a brain abscess caused by Streptococcus constellatus in an immunocompromised patient where oral infection (periodontitis) was suspected to be implicated.
  
  
  METHODS
  The brain abscess and oral isolates were compared by means of one phenotypic and three genetic (restriction fragment length polymorphism [RFLP], ribotyping, and random amplified polymorphic DNA [RAPD]) fingerprinting techniques.
  
  
  RESULTS
  The phenotypic method and RFLP showed identical profiles between brain and periodontal isolates, while ribotyping and RAPD showed very close similarity, with only one band difference in one of the three ribotypes and in one of the three polymorphic RAPD.
  
  
  CONCLUSIONS
  Gene transfer by genetic recombinational events in the periodontal pocket might have been responsible for the emergence of a strain variant of S. constellatus that had the potential to cause an abscess at a distant site (brain). The importance of odontogenic sources as potential foci of infection for brain abscesses is discussed.
authors.affiliation: Department of Oral Biology, Faculty of Dentistry, University of Oslo, Oslo, Norway. rafaels@odont.uio.no
authors.forename: Rafael
authors.initials: R
authors.lastname: Marques da Silva
authors.forename: Dominique A
authors.initials: DA
authors.lastname: Caugant
authors.forename: Roger
authors.initials: R
authors.lastname: Josefsen
authors.forename: Leif
authors.initials: L
authors.lastname: Tronstad
authors.forename: Ingar
authors.initials: I
authors.lastname: Olsen
mesh_terms: D001922:Brain Abscess / Q000209:etiology / Q000382:microbiology*; D004269:DNA, Bacterial / Q000032:analysis; D005260:Female; D005491:Focal Infection, Dental / Q000382:microbiology*; D006801:Humans; D008875:Middle Aged; D010514:Periodontal Pocket / Q000150:complications* / Q000382:microbiology; D012150:Polymorphism, Restriction Fragment Length; D019105:Random Amplified Polymorphic DNA Technique; D021521:Ribotyping; D034365:Streptococcus constellatus / Q000302:isolation & purification
chemical_list: D004269:DNA, Bacterial