TY - JOUR
T1 - Population structure of plasmid-containing strains of Streptococcus mutans, a member of the human indigenous biota
AU - Caufield, Page W.
AU - Saxena, Deepak
AU - Fitch, David
AU - Li, Yihong
PY - 2007/2
Y1 - 2007/2
N2 - 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-conlaining 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-coniaining 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.
AB - 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-conlaining 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-coniaining 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.
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U2 - 10.1128/JB.01183-06
DO - 10.1128/JB.01183-06
M3 - Article
C2 - 17085559
AN - SCOPUS:33846940429
SN - 0021-9193
VL - 189
SP - 1238
EP - 1243
JO - Journal of bacteriology
JF - Journal of bacteriology
IS - 4
ER -