[Roles of periodontal pathogens in the pathogenesis of atherosclerosis].

Periodontitis is closely related to systemic health, especially cardiovascular disease. Periodontal pathogens from periodontal infection actively participate in the formation and development of coronary atherosclerosis. At present, accumulcted evidences show that periodontal pathogen infection is an independent risk factor for cardiovascular events, which promotes the deepening of atherosclerosis through a variety of immune inflammation and metabolism-related molecular mechanisms. The present article reviews multipal aspects of the correlation between periodontitis and periodontal pathogens and cardiovascular disease, and the mechanism of periodontal pathogens affecting the occurrence and development of atherosclerosis.

[Research progress in the interaction between Treponema denticola and microorganisms of subgingival plaque].

Treponema denticola (Td) is a gram-negative anaerobic bacterium closely related to the occurrence and development of periodontal disease and it accounts for a considerable proportion of mature plaque. As a later colonizer of the subgingival plaque biofilm, Td may have complex interactions with earlier and concurrent colonists including symbiotic relationship as while as synergistic or antagonistic effects under the regulation of quorum sensing molecules. Adhesin and coaggregation, mediated by a series of surface molecules, are the basis of the interaction. These interactions are ultimately manifested as gene expression changes in metabolism and virulence, in which are mainly metabolism changes with up- or down-regulation of multiple enzymes related to amino acid metabolism. This article reviews the related researches on the interaction between Td and microorganisms of subgingival plaque.

[Network analysis and characteristics of keystone taxa in periodontitis].

Subgingival microorganisms can orchestrate the microbial community under the influence of environmental factors, thus causing the initiation and progression of periodontitis. Keystone taxa play an important role in the dynamic changes of microbial community. The co-occurrence network analysis may pave the way for screening periodontitis associated candidate keystone taxa in the periodontal microflora. These microorganisms, e.g. Porphyromonas gingivalis, might function via myriad of intermediary taxa or as the chokepoint community-remodeling drivers in response of environmental factors. Herein, we review and discuss the construction of microbial co-occurrence network, the way of screening and identifying keystone taxa using network analysis as well as the characteristic of candidate keystone taxa related to periodontitis for the purpose that keystone taxa and the role they played in dynamic succession of microflora could be well investigated.