Population diversity and dynamics of Streptococcus mitis, Streptococcus oralis, and Streptococcus infantis in the upper respiratory tracts of adults, determined by a nonculture strategy.

ABSTRACT: We reinvestigated the clonal diversity and dynamics of Streptococcus mitis and two other abundant members of the commensal microbiota of the upper respiratory tract, Streptococcus oralis and Streptococcus infantis, to obtain information about the origin of frequently emerging clones in this habitat. A culture-independent method was used, based on cloning and sequencing of PCR amplicons of the housekeeping gene gdh, which shows remarkable, yet species-specific, genetic polymorphism. Samples were collected from all potential ecological niches in the oral cavity and pharynx of two adults on two occasions separated by 2 years. Based on analysis of close to 10,000 sequences, significant diversity was observed in populations of all three species. Fluctuations in the relative proportions of indiv

SUBMITTER: Bek-Thomsen M 

PROVIDER: S-EPMC2346710 | biostudies-literature | 2008 May

REPOSITORIES: biostudies-literature