Childhood Dental Decay Identification
Researchers from the U.S. and abroad suggest that a new method of
genetic profiling may distinguish bacterial populations that cause severe
dental decay in children and be used as a basis for intervention and
prevention development. They report their findings in the January 2007
issue of the Journal of Clinical Microbiology.
Severe early-childhood caries (S-ECC) is an extremely destructive
form of bacterial tooth decay generally involving multiple teeth. Although
previous studies have indicated Streptococcus mutans as a potential
agent, researchers have yet to determine if S-ECC is caused by a single
strain of bacteria or a group of bacterial species. Prior testing based on
cultivation methods has proven difficult because nearly half of the
bacteria in saliva and dental plaque are not cultivable.
In the study researchers collected plaque samples from twenty
children, some with S-ECC and some caries-free (CF), and evaluated the
difference in bacterial diversity using denaturing gradient gel
electrophoresis (DGGE), a cultivation-free method which isolates total
microbial genome DNA. Results showed the S-ECC group exhibited 94.5
bacterial populations while the CF group exhibited 113.4, suggesting that
caries-associated bacteria become less diverse as specific groups
begin to dominate the plaque biofilm.
"These results suggest that the microbial diversity and complexity of
the microbial biota in dental plaque are significantly less in S-ECC children
than in CF children," say the researchers. "Our study also demonstrated
that PCR-based 16S rRNA gene DGGE is a sufficiently valuable tool for
differentiating the microbial composition of the oral plaque in S-ECC
children from that of CF children and may be further developed as a
pattern recognition tool with which to identify specific group of bacteria
predominantly colonized in children of various caries status."
(Y. Li, Y. Ge, D. Saxena, P.W. Caufield. 2006. Genetic profiling of the oral microbiota associated with severe early-childhood carries. Journal of Clinical Microbiology, 45. 1: 81-87.)
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