Link between dental plaque bacteria and blood clots

The Society for General Microbiology has announced some interesting research. Oral bacteria that escape into the bloodstream are able to cause blood clots and trigger life-threatening endocarditis. Further research could lead to new drugs to tackle infective heart disease. Streptococcus gordonii is a normal inhabitant of the mouth and contributes to plaque that forms on the surface of teeth. 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 Royal College of Surgeons in Ireland (RCSI) and the University of Bristol 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, causing them to clump inside blood vessels. These unwanted blood clots 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. It is argued that better understanding of the relationship between bacteria and platelets could ultimately lead to new treatments for infective endocarditis. For further details, see the SGM.