Figure.

Hypothetical model of the mechanism contributing to develop cerebral microbleeds (CMB) by the infection of cnm-positive Streptococcus mutans (S. mutans). A, Normal vessel. Cerebral bleeding may occur at the level of arterioles and capillaries. B, Aging and hypertension results in endothelial damage and thickened basement membranes (BM). C, Bacteremia of S. mutans are induced by brushing, flossing or tooth extraction. Unlike cnm-negative S. mutans, cnm-positive S. mutans can attach to the BM. D, Once cnm-positive S. mutans binds to the vessel wall, infiltration of neutrophils results in local inflammation. The negative charges on the surface of cnm-positive S. mutans inhibit aggregation of platelets, which also possess negative charges on the surfaces. CMB are eventually induced.