These gram positive cocci colonize in the mouth soon after birth. They normally colonize the oral mucosa, the naso-pharynx and the upper respiratory tract. They are usually commensal organisms usually found in the oral cavities.
Usually not pathogenic in nature these bacteria are termed as opportunistic pathogens in nature as they only cause disease when the hosts defense systems are down i.e. immunity is decreased. They are also found in the gastrointestinal tract.
Even though they are found in normal healthy people, they can commonly lead to dental carries. Incase of dental extractions, they bacteria can gain access to the blood stream where they can adhere to the cardiac valves and lead to sub acute bacterial endocarditis. They are associated as being a “Common cause of dental infections, sub-acute bacterial endocarditis and bacteremia. If isolated from CSF or respiratory sections, usually contaminants, but occasionally are responsible for disease.” (Auwaerter P, 2007)
In a study conducted by J. C. Corredoira, (2005) demonstrated that salivarius species was seen as responsible for bacteremia in people who’s oral mucosal membranes had been disrupted or those who were suffering from some underlying disease. They found that a significant number of people with streptococcus salivarius bacteremia lead to endocarditis, non colon tumors as well as colon cancer.