Kazuhiko Nakano
Osaka University, Japan.
Title: Streptococcus mutans and systemic diseases - current knowledge and future perspective
Biography
Biography: Kazuhiko Nakano
Abstract
Streptococcus mutans, a major pathogen of dental caries, is occasionally isolated from blood of patients with bacteremia and infective endocarditis (IE). It has been demonstrated that an approximately 120 kDa collagen-binding protein (Cnm protein) located on the bacterial cell surface is an important factor for onset of IE, as animal experiments using genetically engineered S. mutans strains have clearly demonstrated that Cnm is a major factor for its development. In addition, Cnm-positive S. mutans strains have been more frequently identified in saliva obtained from patients with cerebral hemorrhage, a major complication of IE, as compared to that from healthy subjects. An animal model of cerebral hemorrhage revealed aggravation of cerebral hemorrhage following infection with Cnm-positive S. mutans via the jugular vein. Interestingly, Cnm-positive S. mutans strains have also been more frequently identified in patients with cerebral micro-bleeding. Analyses of various in vitro experiments showed that Cnm of S. mutans possibly inhibits hemostasis of impaired blood vessel endothelium. Furthermore, Cnm-positive S. mutans strains have been shown to aggravate inflammatory bowel diseases and non-alcoholic steatohepatitis by elevating the level of disease-related cytokines secreted in liver tissue. Although large-scale human studies are needed to conclude the relationship of Cnm-positive S. mutans with systemic diseases, it is possible to speculate that oral health approaches to control this specific type of S. mutans may lead to improve a systemically healthy condition.
