Author(s)

Mingyu Li, Guang-yun Lai, Jun Wang

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Purpose:To examine selected putative virulent prop-erties of mutans streptococci in two groups with dif-ferent caries activity and to examine co-culture hy-bridization of the strains in vitro. Methods: A set of strains from caries-free subjects (115) and another set from caries-active subjects (165) were isolated. Each strain was characterized for three virulence determi-nants. The clinical bacteria were then cocultured by three strains exhibiting the highest levels of virulence. Isolate colonies of last filial generation bacteria were enrichment-incubated and estimated for virulence again. RAPD-PCR and MLEE analyses were processed for parental bacteria and last filial genera-tion one. Results: No difference associated with caries activity of the subjects from whom the isolates origi-nated. Virulent properties of a filial generation strains was not different in the same generation, but was very different from their parent strains. Conclu-sion: The coexist properties of virulent polyclonal strain of MS may hold in a very general conditional sense in a dental plaque ecosystem in vivo, however, one of the co-culture strains may became dominant and displa- ced the others as the result of continuous ecological succession in vitro.

Ecological Phenomenon; Mutans Streptococci; Co-Culture; Virulent; in Vitro

Li, M. , Lai, G. and Wang, J. (2011) The prevalence of virulent clonal strains of mutans streptococci in vivo and co-culture succession of the strains in vitro—Virulence potential of mutans streptococci. Open Journal of Stomatology, 1, 18-24. doi: 10.4236/ojst.2011.12004.