Streptococcus mutans



Since it metabolizes sucrose to lactic acid it can cause major tooth decay. Due to the acidic environment that this creates it makes the highly mineralized tooth enamel to be vulnerable to decay. It is one of the few organisms equipped with receptors that improve adhesion to the surface of teeth. It produces a sticky, extracellular, dextran-based polysaccharide that forms plaque. Sucrose is the only sugar it can use to form sticky polysaccharide. It can digest other sugars but they only produce lactic acid as an end product. The combination of plaque and acid leads to dental decay. There have been lots of attempts at a vaccine for the organism although unsuccessfully.