Which statement best describes the purpose of 16S rRNA gene sequencing in oral microbiology?

Which statement best describes the purpose of 16S rRNA gene sequencing in oral microbiology?

• A. To classify bacteria based on 16S sequences
• B. To identify viruses
• C. To determine enzyme activity
• D. To measure pH

Answer: (A)

16S rRNA sequencing is used to classify bacteria based on their gene sequences because this gene is present in all bacteria and contains regions that are highly conserved as well as regions that vary between species. By amplifying and sequencing the conserved portions, researchers can read the hypervariable segments that distinguish different bacteria, then compare those sequences to reference databases to assign taxonomy and infer evolutionary relationships. This approach is especially powerful in oral microbiology because many oral microbes are difficult to culture; sequencing directly from saliva, plaque, or other samples reveals which bacteria are present, often identifying organisms that aren’t easily grown in the lab and letting us assess the community composition and diversity. It’s not used to identify viruses, nor to measure enzyme activity or environmental pH, which require other methods. While 16S sequencing gives strong taxonomic insight, its resolution isn’t perfect for all closely related species, and it provides limited direct data on function without additional analyses.

16S rRNA sequencing is used to classify bacteria based on their gene sequences because this gene is present in all bacteria and contains regions that are highly conserved as well as regions that vary between species. By amplifying and sequencing the conserved portions, researchers can read the hypervariable segments that distinguish different bacteria, then compare those sequences to reference databases to assign taxonomy and infer evolutionary relationships. This approach is especially powerful in oral microbiology because many oral microbes are difficult to culture; sequencing directly from saliva, plaque, or other samples reveals which bacteria are present, often identifying organisms that aren’t easily grown in the lab and letting us assess the community composition and diversity. It’s not used to identify viruses, nor to measure enzyme activity or environmental pH, which require other methods. While 16S sequencing gives strong taxonomic insight, its resolution isn’t perfect for all closely related species, and it provides limited direct data on function without additional analyses.