title: Streptococcus anginosus infection in oral cancer and its infection route.
abstract: OBJECTIVE
  To elucidate a possible involvement of Streptococcus anginosus in oral cancer, we assessed the frequency of S. anginosus infection in oral cancer tissues, and investigated its infection route.
  
  
  METHODS
  The tissue specimens were obtained from 46 oral cancer and three precancerous leukoplakia subjects. Frequency of S. anginosus infection was assessed by a species-specific polymerase chain reaction (PCR) assay. The genotype of the clinical isolates taken from cancer tissue and dental plaque samples was analyzed using pulsed-field gel electrophoresis (PFGE).
  
  
  RESULTS
  S. anginosus DNA was frequently detected in squamous cell carcinoma (19/42), but not in other types of cancer (lymphoma and rhabdomyosarcoma) or leukoplakia samples. A subject-based analysis revealed that S. anginosus was solely detected in dental plaque and not in saliva from all 19 S. anginosus-positive squamous cell carcinoma cases. Further, the genotype of S. anginosus isolated from cancer tissue was identical to that from dental plaque of the same patients.
  
  
  CONCLUSIONS
  Infection of S. anginosus could occur frequently in oral squamous cell carcinoma and that dental plaque could be a dominant reservoir of the S. anginosus.
authors.affiliation: Department of Oral Microbiology, Iwate Medical University School of Dentistry, Morioka, Iwate, Japan.
authors.forename: M
authors.initials: M
authors.lastname: Sasaki
authors.forename: C
authors.initials: C
authors.lastname: Yamaura
authors.forename: Y
authors.initials: Y
authors.lastname: Ohara-Nemoto
authors.forename: S
authors.initials: S
authors.lastname: Tajika
authors.forename: Y
authors.initials: Y
authors.lastname: Kodama
authors.forename: T
authors.initials: T
authors.lastname: Ohya
authors.forename: R
authors.initials: R
authors.lastname: Harada
authors.forename: S
authors.initials: S
authors.lastname: Kimura
mesh_terms: D000368:Aged; D000818:Animals; D002294:Carcinoma, Squamous Cell / Q000382:microbiology*; D003773:Dental Plaque / Q000382:microbiology; D016521:Electrophoresis, Gel, Pulsed-Field; D005260:Female; D006801:Humans; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D009062:Mouth Neoplasms / Q000382:microbiology*; D016133:Polymerase Chain Reaction / Q000592:standards; D012463:Saliva / Q000382:microbiology; D012680:Sensitivity and Specificity; D013290:Streptococcal Infections / Q000150:complications*; D034366:Streptococcus anginosus / Q000235:genetics / Q000302:isolation & purification*