Oral bacteria that escape into the bloodstream are able to cause blood clots and trigger life-threatening endocarditis.
Streptococcus gordonii is a normal inhabitant of the mouth and contributes to plaque that forms on the surface of teeth. However, if these bacteria enter into the blood stream through bleeding gums they can start to wreak havoc by masquerading as human proteins.
Researchers from the University of Bristol and the Royal College of Surgeons in Ireland (RCSI) have discovered that S. gordonii is able to produce a molecule on its surface that lets it mimic the human protein fibrinogen — a blood-clotting factor.
This activates the platelets which then clump inside blood vessels. These unwanted blood clots will then encase the bacteria, protecting them from the immune system and from antibiotics that might be used to treat infection. Platelet clumping can lead to growths on the heart valves (endocarditis), or inflammation of blood vessels that can block the blood supply to the heart or brain.
One of the researchers from the study states:
“In the development of infective endocarditis, a crucial step is the bacteria sticking to the heart valve and then activating platelets to form a clot. We are now looking at the mechanism behind this sequence of events in the hope that we can develop new drugs which are needed to prevent blood clots and also [prevent] infective endocarditis.”
Around 30% of people with infective endocarditis die and most will require surgery for replacement of the infected heart valve with a metal or animal valve.
The researchers are also looking more widely at other dental plaque bacteria that may have similar effects to S. gordonii.
Clearly a drug would be beneficial here. However, this study reiterates that you should be regularly brushing and flossing your teeth.