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Chapter 9 : Porphyromonas gingivalis: the Role of Surface Structures in Virulence and Biofilm Development
Category: Genomics and Bioinformatics
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Studies have shown that Porphyromonas gingivalis surface structures play an important role in the life cycle of the oral anaerobe. In particular, cysteine proteases, fimbriae, membrane vesicles (MVs), and surface polysaccharides have been of primary interest. P. gingivalis is a gram-negative obligate anaerobe that persists in the subgingival crevice of the oral cavity. The chapter provides a review of molecular genetic studies on cysteine proteases, fimbriae, MVs, and surface polysaccharides. It discusses the use of genome sequence information in deciphering the role of surface structures in biofilm development and pathogenicity. The high proteolytic activity of P. gingivalis and its role in nutrient acquisition and virulence are discussed. Surface polysaccharides are key virulence factors of P. gingivalis, as well as of many other gram-negative pathogens. The switch from being a benign member of the oral biofilm to being a proliferating virulent pathogen is central to the pathogenicity of this anaerobe, and changes in expression of surface structures play an important role in this switch. Expression of these surface structures modulates cell-cell and cell-host interactions and thus biofilm development; hence, MVs, gingipains, fimbriae, and surface polysaccharides play a central role in both virulence and biofilm growth.
Key Concept Ranking
- Outer Membrane Proteins
Electron micrograph of P. gingivalis strain 381, showing MV formation. Magnification, ×180,000.
Electron micrograph of P. gingivalis strain 381, showing numerous fimbriae on the surface of the cell. Magnification, ×100,000.