Distinct roles of long/short fimbriae and gingipains in homotypic biofilm development by Porphyromonas gingivalis
Open Access
- 1 January 2009
- journal article
- research article
- Published by Springer Science and Business Media LLC in BMC Microbiology
- Vol. 9 (1), 105
- https://doi.org/10.1186/1471-2180-9-105
Abstract
Porphyromonas gingivalis, a periodontal pathogen, expresses a number of virulence factors, including long (FimA) and short (Mfa) fimbriae as well as gingipains comprised of arginine-specific (Rgp) and lysine-specific (Kgp) cysteine proteinases. The aim of this study was to examine the roles of these components in homotypic biofilm development by P. gingivalis, as well as in accumulation of exopolysaccharide in biofilms. Biofilms were formed on saliva-coated glass surfaces in PBS or diluted trypticase soy broth (dTSB). Microscopic observation showed that the wild type strain formed biofilms with a dense basal monolayer and dispersed microcolonies in both PBS and dTSB. A FimA deficient mutant formed patchy and small microcolonies in PBS, but the organisms proliferated and formed a cohesive biofilm with dense exopolysaccharides in dTSB. A Mfa mutant developed tall and large microcolonies in PBS as well as dTSB. A Kgp mutant formed markedly thick biofilms filled with large clumped colonies under both conditions. A RgpA/B double mutant developed channel-like biofilms with fibrillar and tall microcolonies in PBS. When this mutant was studied in dTSB, there was an increase in the number of peaks and the morphology changed to taller and loosely packed biofilms. In addition, deletion of FimA reduced the autoaggregation efficiency, whereas autoaggregation was significantly increased in the Kgp and Mfa mutants, with a clear association with alteration of biofilm structures under the non-proliferation condition. In contrast, this association was not observed in the Rgp-null mutants. These results suggested that the FimA fimbriae promote initial biofilm formation but exert a restraining regulation on biofilm maturation, whereas Mfa and Kgp have suppressive and regulatory roles during biofilm development. Rgp controlled microcolony morphology and biovolume. Collectively, these molecules seem to act coordinately to regulate the development of mature P. gingivalis biofilms.Keywords
This publication has 49 references indexed in Scilit:
- A Porphyromonas gingivalis tyrosine phosphatase is a multifunctional regulator of virulence attributesMolecular Microbiology, 2008
- Inhibitory effect of cranberry polyphenol on biofilm formation and cysteine proteases of Porphyromonas gingivalisJournal of Periodontal Research, 2007
- Effects of a high-molecular-weight cranberry fraction on growth, biofilm formation and adherence of Porphyromonas gingivalisJournal of Antimicrobial Chemotherapy, 2006
- Structural analysis of a novel anionic polysaccharide from Porphyromonas gingivalis strain W50 related to Arg‐gingipain glycansMolecular Microbiology, 2005
- Synergistic biofilm formation byTreponema denticolaandPorphyromonas gingivalisFEMS Microbiology Letters, 2005
- Porphyromonas gingivalis, Treponema denticola, and Tannerella forsythia: the ‘red complex’, a prototype polybacterial pathogenic consortium in periodontitisPeriodontology 2000, 2005
- Gingipain adhesin domains mediate Porphyromonas gingivalis adherence to epithelial cellsMicrobial Pathogenesis, 2004
- Variations of Porphyromonas gingivalis fimbriae in relation to microbial pathogenesisJournal of Periodontal Research, 2004
- The Role of Gingipains in the Pathogenesis of Periodontal DiseaseThe Journal of Periodontology, 2003
- Porphyromonas gingivalis Proteinases as Virulence Determinants in Progression of Periodontal DiseasesThe Journal of Biochemistry, 2000