Monthly Archives: januari 2014

januari 28, 2014 Dental plaque bacteria may trigger blood clots

Better understanding of the relationship between oral bacteria and blood clots could ultimately lead to new treatments for infective endocarditis.
That’s according to scientists from the University of Bristol and the Royal College of Surgeons in Ireland.
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, say scientists presenting their work at the Society for General Microbiology’s Spring Conference in Dublin this week.
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.
The research led by Howard Jenkinson, Professor of Oral Microbiology and Head of Research at the University of Bristol’s School of Oral and Dental Sciences, in collaboration with Dr Steve Kerrigan from the Royal College of Surgeons in Ireland (RCSI) has 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.
Dr Helen Petersen, who completed her PhD at the University of Bristol in February 2011, presenting the work said that better understanding of the relationship between bacteria and platelets could ultimately lead to new treatments for infective endocarditis.
‘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 infective endocarditis,’ she said.
Infective endocarditis is treated with surgery or by strong antibiotics – which is becoming more difficult with growing antibiotic resistance.
‘About 30% cent of people with infective endocarditis die and most will require surgery for replacement of the infected heart valve with a metal or animal valve,’ said Dr Petersen.
‘Our team has now identified the critical components of the S. gordonii molecule that mimics fibrinogen, so we are getting closer to being able to design new compounds to inhibit it. This would prevent the stimulation of unwanted blood clots,’ said Dr Steve Kerrigan from the RCSI.
The team are also looking more widely at other dental plaque bacteria that may have similar effects to S. gordonii.
‘We are also trying to determine how widespread this phenomenon is by studying other bacteria related to S. gordonii. What our work clearly shows is how important it is to keep your mouth healthy through regular brushing and flossing, to keep these bacteria in check,’ stressed Dr Petersen.

januari 8, 2014 Poor oral hygiene and excess sugar consumption can lead to periodontal disease

— The association between poor oral health and increased risk of cardiovascular disease and those in the risk zone should make the reduction of sugars such as those contained in junk food, particularly fizzy drinks, an important health policy target, say experts writing in the Journal of the Royal Society of Medicine.

Poor oral hygiene and excess sugar consumption can lead to periodontal disease where the supporting bone around the teeth is destroyed. It is thought that chronic infection from gum disease can trigger an inflammatory response that leads to heart disease through a process called atherosclerosis, or hardening of the arteries. Despite convincing evidence linking poor oral health to premature heart disease, the most recent UK national guidance on the prevention of CVD at population level mentions the reduction of sugar only indirectly.

Dr Ahmed Rashid, Department of Public Health and Primary Care, University of Cambridge, who co-wrote the paper, said: ”As well as having high levels of fats and salt, junk foods often contain a great deal of sugar and the effect this has on oral health may be an important additional mechanism by which junk food elevates risk of CVD.” He added: ”Among different types of junk food, soft drinks have raised particular concerns and are the main source of free sugar for many individuals.”

The authors refer to the well-publicized New York ‘soda ban’ controversy which has brought the issue to the attention of many. Yet, they point out, in the UK fizzy drinks remain commonly available in public areas ranging from hospitals to schools. Dr Rashid said: ”The UK population should be encouraged to reduce fizzy drink intake and improve oral hygiene. Reducing sugar consumption and managing dental problems early could help prevent heart problems later in life.