Aggravation of inflammatory bowel diseases by oral streptococci

作者：Kojima A; Nomura R; Naka S; Okawa R; Ooshima T; Nakano K^*

来源：Oral Diseases, 2014, 20(4): 359-366.

DOI：10.1111/odi.12125

• liver
• oral streptococci
• interferon-gamma
• bacteraemia
• inflammatory bowel diseases

Objectives
Streptococcus mutans can aggravate colitis in mice. We evaluated the virulence of colitis using type strains as well as blood isolates of several oral streptococcal species.
Materials and Methods
We investigated the susceptibility of blood isolates of several oral streptococci to phagocytosis, adhesion to and invasion of hepatic cells and interferon-gamma secretion. A mouse model of dextran sodium sulphate-induced colitis was used to evaluate bacterial aggravation of colitis. In addition, interferon-gamma antibody was administered to mice with prominent aggravation of colitis.
Results
In vitro analyses showed that Streptococcus sanguinis ATCC 10556 was a possible virulent strain among type strains of several oral streptococci, and that analysis of blood isolates of S.sanguinis TW289 revealed a potential virulent strain. Intravenous administration of ATCC 10556 and TW289 caused prominent aggravation of dextran sodium sulphate-induced colitis, and histopathological examinations showed that interferon-gamma secretion due to infection of hepatic cells caused colitis aggravation. Administration of interferon-gamma antibody suppressed TW289-induced colitis.
Conclusion
These results suggest that some virulent oral streptococcal strains are associated with the aggravation of colitis induced by enhanced secretion of interferon-gamma when they invade the bloodstream.

• 出版日期2014-5