Scientists decode genome of oral pathogen

Apr 05, 2007
Scientists decode genome of oral pathogen
Transmission electron micrograph of S. sanguinis. Image courtesy of Lauren Turner/VCU

Virginia Commonwealth University researchers have decoded the genome of a bacteria normally present in the healthy human mouth that can cause a deadly heart infection if it enters the bloodstream.

The finding enables scientists to better understand the organism, Streptococcus sanguinis, and develop new strategies for treatment and infection prevention.

S. sanguinis, a type of bacteria that is naturally present in the mouth, is among a variety of microorganisms responsible for the formation of dental plaque. In general, S. sanguinis is harmless. However, if it enters the bloodstream, possibly through a minor cut or wound in the mouth, it can cause bacterial endocarditis, a serious and often lethal infection of the heart.

Individuals with preexisting heart problems are at an increased risk of developing bacterial endocarditis. The infection may result in impaired heart function and complications such as heart attack and stroke. Typically, before dental surgery, such patients are given high dose antibiotics to prevent infection.

Decoding S. sanguinis, a streptococcal bacteria, will provide researchers with unique insight into its complex life cycle, metabolism and its ability to invade the host and cause bacterial endocarditis.

"We can apply this information toward the design of new treatments and preventative strategies to protect against this disease," said lead investigator, Francis Macrina, Ph.D., VCU's vice president for research. "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. We are already at work pursuing some of these leads."

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," added Macrina.

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 analyzed the S. sanguinis genome and 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.

"The sequence of the S. sanguinis genome gives us a comprehensive view of the biological potential of this important pathogen," said Gregory A. Buck, Ph.D., director of the Center for the Study of Biological Complexity at VCU, who directed the sequencing and analysis. "This data opens a window into the inner workings of this bacterium. We now may be able to determine how and why these organisms cause disease."

The findings were reported in the April 2007 issue of the Journal of Bacteriology, which is published by the American Society of Microbiology.

Source: Virginia Commonwealth University

Explore further: Premature aging: Scientists identify and correct defects in diseased cells

Related Stories

Polysis is marketing a plastic that turns to clay

4 hours ago

Polysis is showing a plastic that can turn to clay when heated, according to a story on DigInfo TV. Polysis is described as a specialist developer of polyurethane resins and resin products, and they are marketing haplafreely, presented with a lower- ...

Wolfram's ID project launch touts ImageIdentify function

8 hours ago

You see a picture but you cannot name it. "What animal is this?" "Hmm, sort of looks like a guitar, not a cello—what is this instrument?" The Wolfram Language Identification Project was launched on Wednesday ...

Malaysian dam project opposed by tribes gets green light

8 hours ago

Construction of a Malaysian dam that will flood a rainforested area half the size of Singapore and displace 20,000 tribespeople was given the green light Saturday by the state government, local media reported.

Typhoon Dolphin looms over Guam

8 hours ago

Typhoon Dolphin passed through the Northern Marianas today just to the north of Guam with sustained winds estimated at 95 knots (~109 mph) by the Joint Typhoon Warning Center (JTWC). The center passed through ...

Recommended for you

Why you need one vaccine for measles and many for the flu

17 hours ago

While the influenza virus mutates constantly and requires a yearly shot that offers a certain percentage of protection, old reliable measles needs only a two-dose vaccine during childhood for lifelong immunity. ...

Scientists turn blood into neural cells

17 hours ago

Scientists at McMaster University have discovered how to make adult sensory neurons from human patients simply by having them roll up their sleeve and providing a blood sample.

How our gut changes across the life course

19 hours ago

Scientists and clinicians on the Norwich Research Park have carried out the first detailed study of how our intestinal tract changes as we age, and how this determines our overall health.

User comments : 0

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.