title: Bacterial DNA findings in ruptured and unruptured intracranial aneurysms.
abstract: OBJECTIVE
  Chronic inflammation has earlier been detected in ruptured intracranial aneurysms. A previous study detected both dental bacterial DNA and bacterial-driven inflammation in ruptured intracranial aneurysm walls. The aim of this study was to compare the presence of oral and pharyngeal bacterial DNA in ruptured and unruptured intracranial aneurysms. The hypothesis was that oral bacterial DNA findings would be more common and the amount of bacterial DNA would be higher in ruptured aneurysm walls than in unruptured aneurysm walls.
  
  
  METHODS
  A total of 70 ruptured (n = 42) and unruptured (n = 28) intracranial aneurysm specimens were obtained perioperatively in aneurysm clipping operations. Aneurysmal sac tissue was analysed using a real-time quantitative polymerase chain reaction to detect bacterial DNA from several oral species. Both histologically non-atherosclerotic healthy vessel wall obtained from cardiac by-pass operations (LITA) and arterial blood samples obtained from each aneurysm patient were used as control samples.
  
  
  RESULTS
  Bacterial DNA was detected in 49/70 (70%) of the specimens. A total of 29/42 (69%) of the ruptured and 20/28 (71%) of the unruptured aneurysm samples contained bacterial DNA of oral origin. Both ruptured and unruptured aneurysm tissue samples contained significantly more bacterial DNA than the LITA control samples (p-values 0.003 and 0.001, respectively). There was no significant difference in the amount of bacterial DNA between the ruptured and unruptured samples.
  
  
  CONCLUSIONS
  Dental bacterial DNA can be found using a quantitative polymerase chain reaction in both ruptured and unruptured aneurysm walls, suggesting that bacterial DNA plays a role in the pathogenesis of cerebral aneurysms in general, rather than only in ruptured aneurysms.
authors.affiliation: a Department of Oral and Maxillofacial Diseases , Tampere University Hospital , Tampere , Finland ;|b Oral Health Services , City of Tampere, Tampere , Finland ;
authors.forename: Mikko J
authors.initials: MJ
authors.lastname: Pyysalo
authors.affiliation: c Department of Neurosurgery , Tampere University Hospital , Tampere , Finland ;
authors.forename: Liisa M
authors.initials: LM
authors.lastname: Pyysalo
authors.affiliation: d School of Medicine, University of Tampere and Fimlab Laboratories Ltd, Pirkanmaa Hospital District , Tampere , Finland ;
authors.forename: Tanja
authors.initials: T
authors.lastname: Pessi
authors.affiliation: d School of Medicine, University of Tampere and Fimlab Laboratories Ltd, Pirkanmaa Hospital District , Tampere , Finland ;|e Department of Clinical Pathology and Forensic Medicine , University of Kuopio , Kuopio , Finland ;
authors.forename: Pekka J
authors.initials: PJ
authors.lastname: Karhunen
authors.affiliation: f Department of Clinical Chemistry , Fimlab Laboratories and School of Medicine University of Tampere , Tampere , Finland ;
authors.forename: Terho
authors.initials: T
authors.lastname: Lehtimäki
authors.affiliation: f Department of Clinical Chemistry , Fimlab Laboratories and School of Medicine University of Tampere , Tampere , Finland ;|g Department of Surgery, Vascular Surgery , Tampere University Hospital , Tampere , Finland.
authors.forename: Niku
authors.initials: N
authors.lastname: Oksala
authors.affiliation: c Department of Neurosurgery , Tampere University Hospital , Tampere , Finland ;
authors.forename: Juha E
authors.initials: JE
authors.lastname: Öhman
mesh_terms: D016976:Aggregatibacter actinomycetemcomitans / Q000235:genetics; D017542:Aneurysm, Ruptured / Q000382:microbiology*; D004269:DNA, Bacterial / Q000302:isolation & purification*; D005260:Female; D016967:Fusobacterium nucleatum / Q000235:genetics; D016965:Gram-Negative Anaerobic Straight, Curved, and Helical Rods / Q000235:genetics; D006801:Humans; D002532:Intracranial Aneurysm / Q000382:microbiology*; D008297:Male; D008875:Middle Aged; D009055:Mouth / Q000382:microbiology*; D010462:Peptostreptococcus / Q000235:genetics; D010614:Pharynx / Q000382:microbiology; D016966:Porphyromonas gingivalis / Q000235:genetics; D018713:Prevotella intermedia / Q000235:genetics; D013211:Staphylococcus aureus / Q000235:genetics; D013212:Staphylococcus epidermidis / Q000235:genetics; D034366:Streptococcus anginosus / Q000235:genetics; D054773:Streptococcus gordonii / Q000235:genetics; D034361:Streptococcus mitis / Q000235:genetics; D019533:Streptococcus oralis / Q000235:genetics; D013298:Streptococcus sanguis / Q000235:genetics; D014070:Tooth / Q000382:microbiology; D048373:Treponema denticola / Q000235:genetics
chemical_list: D004269:DNA, Bacterial
keywords: Bacteriology; cerebrovascular disease; oral medicine; subarachnoid haemorrhage