title: The distribution of periodontopathic bacteria among Japanese children and their parents.
abstract: OBJECTIVE
  It is not well known how periodontopathic bacteria colonize in the oral cavity during childhood. The purpose of this study was to investigate the distribution of periodontopathic bacteria in oral cavities of children and their parents and the relationship between the bacterial findings and clinical parameters.
  
  
  METHODS
  Fifty-six children (mean age: 8.3 +/- 3.5, range: 1-15 years), including 15 with deciduous dentition, 26 with mixed dentition and 15 with permanent dentition, and their parents participated in this study. Whole saliva and dental plaque of the children and whole saliva of their parents were collected for detection of seven species of periodontopathic bacteria (Actinobacillus actinomycetemcomitans, Tannerella forsythensis (Bacteroides forsythus), Campylobacter rectus, Porphyromonas gingivalis, Prevotella intermedia, Prevotella nigrescens and Treponema denticola) using the polymerase chain reaction method. Clinical parameters including simplified Oral Hygiene Index and Papillary-Marginal-Attachment Index were recorded for the children and their accompanied parents.
  
  
  RESULTS
  The detection frequencies of T. forsythensis, C. rectus, P. nigrescens, T. denticola, A. actinomycetemcomitans and P. gingivalis in the oral cavities of children were 42.9%, 94.6%, 42.9%, 48.2%, 1.8% and 8.9%, respectively. T. forsythensis, P. gingivalis and T. denticola were detected more frequently in the saliva of parents (54.8%, 54.8%, 88.1%, respectively) than in the saliva of children (25.5%, 7.3%, 41.8%, respectively). Different detection frequencies of P. nigrescens were found among the oral cavities of children with deciduous, mixed and permanent dentitions. In mixed dentition, females harbored T. forsythensis more frequently than males did. Children who harbored T. forsythensis, P. intermedia, P. nigrescens and T. denticola showed high scores for oral debris measurement by simplified Oral Hygiene Index. T. forsythensis, P. intermedia and P. nigrescens were detected more frequently in children whose parents were positive for these pathogens than in children whose parents were negative.
  
  
  CONCLUSIONS
  High plaque retention seems to promote the colonization of periodontal pathogens in the oral cavities of children. T. forsythensis, P. intermedia and P. nigrescens were detected more frequently in the oral cavities of children whose parents already harbored these bacteria. Familial transmission of these bacteria is suggested.
authors.affiliation: Section of Periodontology, Department of Hard Tissue Engineering, Tokyo Medical and Dental University, Japan. umeda.peri@tmd.ac.jp
authors.forename: Makoto
authors.initials: M
authors.lastname: Umeda
authors.forename: Zenzo
authors.initials: Z
authors.lastname: Miwa
authors.forename: Yasuo
authors.initials: Y
authors.lastname: Takeuchi
authors.forename: Motoko
authors.initials: M
authors.lastname: Ishizuka
authors.forename: Yi
authors.initials: Y
authors.lastname: Huang
authors.forename: Kazuyuki
authors.initials: K
authors.lastname: Noguchi
authors.forename: Mitsuro
authors.initials: M
authors.lastname: Tanaka
authors.forename: Yuzo
authors.initials: Y
authors.lastname: Takagi
authors.forename: Isao
authors.initials: I
authors.lastname: Ishikawa
mesh_terms: D000293:Adolescent; D000704:Analysis of Variance; D001424:Bacterial Infections / Q000635:transmission*; D016009:Chi-Square Distribution; D002648:Child; D002675:Child, Preschool; D004269:DNA, Bacterial / Q000235:genetics; D003773:Dental Plaque / Q000382:microbiology*; D005260:Female; D006090:Gram-Negative Bacteria / Q000302:isolation & purification*; D006801:Humans; D007223:Infant; D018445:Infectious Disease Transmission, Vertical; D007564:Japan; D008297:Male; D009911:Oral Hygiene Index; D010290:Parents; D010512:Periodontal Index; D016133:Polymerase Chain Reaction; D012463:Saliva / Q000382:microbiology
chemical_list: D004269:DNA, Bacterial