MITIS SALIVARIUS AGAR BASE

Streptococcus species are mostly commensal residents of the mouth and throat, though several may act as opportunistic pathogens and a few as primary pathogens. Streptococcus ?viridans? group consists of Streptococcus salivarius and Streptococcus mitis. They exhibit different types of haemolysis when grown on Blood Agar Base. Therefore, it is difficult to differentiate these organisms found in saliva from the other accompanying flora. Mitis Salivarius Agar Base is used for the isolation of S.mitis, S. salivarius and Enterococcus faecalis from mixed cultures. E. faecalis is the most common member of the Enterococci to cause infections in humans and is also a cause of human endocarditis. Mitis Salivarius Agar is formulated as per Chapman. This medium (with 1% potassium tellurite) is a highly selective medium, which enables to isolate streptococci from highly contaminated specimens like exudates from body cavities and faeces etc., as it inhibits a wide variety of bacteria. Some authors have also used sodium azide in this medium to inhibit the growth of gram-negative bacteria like Proteus

for isolation of Streptococci from mixed cultures, especially Streptococcus mitis, Streptococcus salivarius and Streptococcus faecalis from grocely contaminated specimens