New bacterial species found in human mouth

London -- British scientists say they have discovered a new species of bacteria in the human mouth.

The Kings College London Dental Institute researchers led by Professor William Wade said their finding could further expand science's understanding of tooth decay and gum disease.

"The healthy human mouth is home to a tremendous variety of microbes including viruses, fungi, protozoa and bacteria," said Wade. "The bacteria are the most numerous: there are 100 million in every milliliter of saliva and more than 600 different species in the mouth. Around half of these have yet to be named and we are trying to describe and name the new species."

The scientists found three strains of bacteria called Prevotella that could not be identified. Prevotella species are part of the normal microbial flora in humans and are also associated with various oral diseases and infections in other parts of the body. The researchers named the new species Prevotella histicola.

They said the species was isolated from within the oral tissues, both in oral cancers and normal, healthy tissue, confirming other work showing oral bacteria can invade both tissues and individual cells.

The research is reported in the International Journal of Systematic and Evolutionary Microbiology.

Copyright 2008 by United Press International.