バイオフィルムと全身疾患—薬剤耐性口腔内バイオフィルム感染症への対応—

Abstract

Oral biofilm-forming bacteria consist of a dense bacterial mass tightly adhering to the surface of the oral cavity. The characteristics of dental biofilm are resistant against not only host defense mechanisms but also various antimicrobial agents. The predominant bacteria forming biofilm result in persistent infection. The proteolytic enzymes, exotoxins, endotoxins, and HSPs of these bacteria play a significant role in the development of oral infectious disease and affect systemic condition.We detected DNA and antigen of Treponema denticola in atherosclerotic lesions, and also found that the 16S rRNAs of Porphyromonas gingivalis, Aggregatibacter (formally Actinobacillus) actinomycetemcomitans,Tannerella forsythia, T. denticola, and Campylobacter rectus in samples of stenotic coronary arterial plaque. We showed the invasive activity of these bacteria into human vein endothelial cells. Increasing evidence has linked the dental biofilm with respiratory infectious diseases such as aspiration pneumonia in elderly persons. We investigated the effects of oral health care for elderly persons requiring nursing care on prevention of influenza infection.In the oral care group, colony-forming cell number, neuraminidase and trypsin-like protease activities in saliva decreased. It was found that one of 98 patients was diagnosed with influenza; whereas, in the non-oral care group,nine of 92 patients were diagnosed with influenza. The finding indicates that oral hygiene is one of the effective strategies to prevent influenza infection. Periodontal surrounding cells such as macrophage possessing TLRs and CD14 that are endotoxin binding protein. Carrying endotoxin with macrophage to various tissues releases inflammatory cytokines such as TNF-αand IL-1 that produce resistance to insulin sensitivity and cause obesity and diabetes. An attempt to discover new things by studying the past through scrutiny of old, there are many evidences on the close relationship between the primary dental biofilm infectious diseases and secondly systemic diseases such as nephritis, dermatitis and arthritis.The author firmly believes that control of oral biofilm-forming infectious diseases by the surgical treatment is an essential strategy and management of such systemic conditions.