title: Comparison of the detection of periodontal pathogens in bacteraemia after tooth brushing by culture and molecular techniques.
abstract: BACKGROUND
  The prevalence and amounts of periodontal pathogens detected in bacteraemia samples after tooth brushing-induced by means of four diagnostic technique, three based on culture and one in a molecular-based technique, have been compared in this study.
  
  
  METHODS
  Blood samples were collected from thirty-six subjects with different periodontal status (17 were healthy, 10 with gingivitis and 9 with periodontitis) at baseline and 2 minutes after tooth brushing. Each sample was analyzed by three culture-based methods [direct anaerobic culturing (DAC), hemo-culture (BACTEC), and lysis-centrifugation (LC)] and one molecular-based technique [quantitative polymerase chain reaction (qPCR)]. With culture any bacterial isolate was detected and quantified, while with qPCR only Porphyromonas gingivalis and Aggregatibacter actinomycetemcomitans were detected and quantified. Descriptive analyses, ANOVA and Chi-squared tests, were performed.
  
  
  RESULTS
  Neither BACTEC nor qPCR detected any type of bacteria in the blood samples. Only LC (2.7%) and DAC (8.3%) detected bacteraemia, although not in the same patients. Fusobacterium nucleatum was the most frequently detected bacterial species.
  
  
  CONCLUSIONS
  The disparity in the results when the same samples were analyzed with four different microbiological detection methods highlights the need for a proper validation of the methodology to detect periodontal pathogens in bacteraemia samples, mainly when the presence of periodontal pathogens in blood samples after tooth brushing was very seldom.
authors.affiliation: Oral Research Laboratory, Faculty of Odontology, University Complutense of Madrid, Plaza Ramón y Cajal, s/n, Ciudad Universitaria, 28040 Madrid, Spain, mariajosemarin@gmail.com.
authors.forename: M-J
authors.initials: MJ
authors.lastname: Marín
authors.forename: E
authors.initials: E
authors.lastname: Figuero
authors.forename: I
authors.initials: I
authors.lastname: González
authors.forename: A
authors.initials: A
authors.lastname: O'Connor
authors.forename: P
authors.initials: P
authors.lastname: Diz
authors.forename: M
authors.initials: M
authors.lastname: Álvarez
authors.forename: D
authors.initials: D
authors.lastname: Herrera
authors.forename: M
authors.initials: M
authors.lastname: Sanz
mesh_terms: D016976:Aggregatibacter actinomycetemcomitans / Q000302:isolation & purification; D016470:Bacteremia; D003773:Dental Plaque; D006801:Humans; D016966:Porphyromonas gingivalis / Q000302:isolation & purification; D014099:Toothbrushing