This Article Full Text Full Text (PDF) Other Versions of this Article: JB.01183-06v1 189/4/1238    most recent Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Reprints and Permissions Copyright Information Books from ASM Press MicrobeWorld Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Caufield, P. W. Articles by Li, Y. Search for Related Content PubMed PubMed Citation Articles by Caufield, P. W. Articles by Li, Y.

 Previous Article  |  Next Article 

Journal of Bacteriology, February 2007, p. 1238-1243, Vol. 189, No. 4
0021-9193/07/$08.00+0     doi:10.1128/JB.01183-06
Copyright © 2007, American Society for Microbiology. All Rights Reserved.

Population Structure of Plasmid-Containing Strains of Streptococcus mutans, a Member of the Human Indigenous Biota

College of Dentistry,¹ School of Medicine,² Department of Biology, New York University, New York, New York³

Received 31 July 2006/ Accepted 25 October 2006

There are suggestions that the phylogeny of Streptococcus mutans, a member of the human indigenous biota that is transmitted mostly mother to child, might parallel the evolutionary history of its human host. The relatedness and phylogeny of plasmid-containing strains of S. mutans were examined based on chromosomal DNA fingerprints (CDF), a hypervariable region (HVR) of a 5.6-kb plasmid, the rRNA gene intergenic spacer region (IGSR), serotypes, and the genotypes of mutacin I and II. Plasmid-containing strains were studied because their genetic diversity was twice as great as that of plasmid-free strains. The CDF of S. mutans from unrelated human hosts were unique, except those from Caucasians, which were essentially identical. The evolutionary history of the IGSR, with or without the serotype and mutacin characters, clearly delineated an Asian clade. Also, a continuous association with mutacin II could be reconstructed through an evolutionary lineage with the IGSR, but not for serotype e. DNA sequences from the HVR of the plasmid produced a well-resolved phylogeny that differed from the chromosomal phylogeny, indicating that the horizontal transfer of the plasmid may have occurred multiple times. The plasmid phylogeny was more congruent with serotype e than with mutacin II evolution, suggesting a possible functional correlation. Thus, the history of this three-tiered relationship between human, bacterium, and plasmid supported both coevolution and independent evolution.

Published ahead of print on 3 November 2006.

This article has been cited by other articles:

• Saxena, D., Caufield, P. W., Li, Y., Brown, S., Song, J., Norman, R. (2008). Genetic Classification of Severe Early Childhood Caries by Use of Subtracted DNA Fragments from Streptococcus mutans. J. Clin. Microbiol. 46: 2868-2873 [Abstract] [Full Text]