A type of bacteria found in the mouth has the potential to cause serious illness - even death - if it enters the bloodstream through bleeding gums or mouth ulcers.
The Daily Mail reports that scientists have recently identified the bacteria, called Streptococcus tigurinus, and are now trying to establish how common it is and how much of a risk it poses to public health.
Researchers from the University of Zurich in Switzerland isolated the bacterium from the blood of patients suffering from serious conditions including inflammation of the heart (endocarditis), meningitis and inflammation of the spine (spondylodiscitis).
They have found that it is similar to other strains of Streptococcus that are found in the mouth and they are now trying to discover how it spreads.
Dr Andrea Zbinden, who led the study, said that the discovery of the new bacterium is no cause for alarm, but it's important that doctors are aware of it and know how to treat and limit its spread.
She said: "This bacterium seems to have a natural potential to cause severe disease and so it's important that clinicians and microbiologists are aware of it.
"The next step is to work out exactly how common this bacterium is in the oral cavity and what risk it poses.
"Immunosuppression, abnormal heart valves, dental surgeries or chronic diseases are common predisposing factors for blood infections by this group of bacteria. However, the specific risk factors for S. tigurinus remain to be determined."