S. sanguinis has extra DNA that may improve its ability to survive better in the face of good oral hygiene.
Virginia Commonwealth University (VCU) researchers decoded the genome of a bacteria, Streptococcus sanguinis, which is responsible for dental plaque as well as heart infection if it enters the bloodstream.
“Analysis of the genome revealed a surprising number of proteins on the S. sanguinis cell surface that may be new targets for drugs or vaccines,” says lead investigator, Francis Macrina, Ph.D., VCU’s vp of research. “We are already at work pursuing some of these leads.”
The team reported that the genome of the gram-positive bacterium is a circular DNA molecule consisting of approximately 2.4 million base pairs. They found that it was larger than other streptococci that have been sequenced. Some of this extra DNA was apparently adopted from another bacterium and encodes genes that may give S. sanguinis the ability to survive better in the face of good oral hygiene. If so, this could explain the recent emergence of S. sanguinis as an important pathogen.
Although it is not directly associated with tooth decay or gum disease, S. sanguinis is a prominent member of dental plaque. “Genomic studies of this organism will also help us better understand the formation of dental plaque and the initiation of oral diseases,” concludes Dr. Macrina.
