Research Description

Genome Analysis of Oral Pathogens

For years there has been a correlation between poor oral hygiene and cardiac problems. Recently this correlation has been explained by oral microbial populations that invade the blood stream and cause the build up and instability of atherosclerotic plaque. In patients with periodontal disease invasion of the blood stream and the following endocarditis is more common because of the available route for invasion into the bloodstream. During the course of this summer I analyzed the genome sequence of all publicly available genomes of known oral pathogens. Genome sequences and annotation information are made public on the National Center for Biotechnology Information website. During this post genomic era there is such a large abundance of readily available sequence information that can be used to make comparisons between species.

For this project I analyzed the genomes of Streptococcus sanguinis, Treponema denticola, Streptococcus mutans, and Porphyromonas gingivalis. These species are not closely related but all thrive in the oral cavity and have been associated with cardiovascular disease. In all sequenced organisms to date only approximately 70 % of the theoretical genes are given an assigned function. Through the sequencing of microorganisms we observed how little we knew about the total diversity of life on this planet. Through comparative genomics hypothetical gene targets can be associated with virulence factors, biofilm production, or plaque formation. Identifying possible functions of hypothetical genes is important to understand the new influx of metagenomic data being produced by the Human Microbiome project.