Researchers have discovered a mouth bacterium that could be deadly if it enters the bloodstream through bleeding gums.
Scientists from the University of Zurich in Switzerland isolated the lethal bug, streptococcus tigurinus, in the bloodstream of patients with meningitis, spondylodiscitis (inflammation of the spine) and endocarditis (inflammation of the heart).
It is hoped the findings, published in the International Journal of Systematic and Evolutionary Microbiology will help scientists to establish how common the bacterium is in the mouth, how it spreads and the potential health risk it poses.
Lead researcher Dr Andrea Zbinden said, as cited by the Daily Mail, the 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".
Bleeding gums are a common side effect of gum disease. According to the NHS, it is estimated that 50-90% of the adult population in the UK has some degree of gum disease (also known as gingivitis).
Mild cases of gum disease can usually be treated with good oral hygiene, including brushing your teeth for two minutes morning and night, flossing three times a week and using an anti-bacterial mouthwash.
If left untreated, gum disease can develop into periodontitis, which can destroy parts of the gums and loose unstable teeth.