부산대학교 도서관

In this chapter, the role of different microbial virulence factors in relation to the pathogenesis of periodontal diseases is addressed. These factors are molecules produced by pathogens and contribute to their pathogenicity by promoting colonization and affecting host response. The importance of different virulence factors in the life of the oral biofilm and the interplay with the host’s response is exemplified here by two of the major, and most well studied, periodontal pathogens, Porphyromonas gingivalis and Aggregatibacter actinomycetemcomitans. Both of these microbes have great genetic intraspecies diversity and express a number of different virulence factors, which have the capacity to cause imbalance in the host’s response. A. actinomycetemcomitans is the major pathogen in aggressive forms of periodontitis (Fig. 4.1) that affect young individuals, while P. gingivalis is frequently detected in periodontal pockets of individuals with the chronic forms of the disease (Fig. 4.2). However, the role of these two bacteria in periodontal breakdown is still not entirely clear.