title: Molecular analysis of age-related changes of Streptococcus anginosus group and Streptococcus mitis in saliva.
abstract: The purpose of this study was to survey the prevalence of streptococcal species, especially Streptococcus anginosus (which has been reported to be associated with cancer in the upper digestive tract), Streptococcus constellatus, and Streptococcus intermedius in the saliva of different age groups. A sequence analysis of 16S rDNA was performed and DNA quantified using real-time polymerase chain reaction. The S. anginosus level increased with age, whereas the levels of S. constellatus and S. intermedius did not change. Streptococcus mitis was the predominant species in the saliva of all the age groups but, unlike the S. anginosus, the proportion of S. mitis in the salivary bacteria decreased with age. The increase in S. anginosus with age should be carefully monitored because of its association with diseases, including cancer.
authors.affiliation: Graduate School of Humanities and Sciences, Nara Women's University, Nara, Japan.
authors.forename: E
authors.initials: E
authors.lastname: Morita
authors.forename: M
authors.initials: M
authors.lastname: Narikiyo
authors.forename: E
authors.initials: E
authors.lastname: Nishimura
authors.forename: A
authors.initials: A
authors.lastname: Yano
authors.forename: C
authors.initials: C
authors.lastname: Tanabe
authors.forename: H
authors.initials: H
authors.lastname: Sasaki
authors.forename: N
authors.initials: N
authors.lastname: Hanada
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D015373:Bacterial Typing Techniques; D004269:DNA, Bacterial / Q000032:analysis; D004275:DNA, Ribosomal / Q000032:analysis; D006801:Humans; D008875:Middle Aged; D016133:Polymerase Chain Reaction; D012463:Saliva / Q000382:microbiology*; D017422:Sequence Analysis, DNA; D018709:Statistics, Nonparametric; D034366:Streptococcus anginosus / Q000235:genetics / Q000302:isolation & purification*; D034367:Streptococcus intermedius / Q000235:genetics / Q000302:isolation & purification; D034361:Streptococcus mitis / Q000235:genetics / Q000302:isolation & purification*
chemical_list: D004269:DNA, Bacterial; D004275:DNA, Ribosomal