1. Periodontal Pathogens Flashcards
Name 3 microorganisms which exist in oral health.
Oral streptococci.
Actinmyces.
Fusobacterium.
Name 2 micro-organisms which exist in gingivitis.
Actinmyces.
Prevotella intermedia.
Name the three keystone pathogens for severe periodontal disease (red complex) outlined in Socransky’s model.
P. Gingivalis.
T. Forsythia.
T. Denticola.
What are the two microbial interactions which exist ?
Competition i.e. dominance.
Co-operation i.e. integration.
What are examples of competition microbial interactions ?
Metabolic products like acid conditions, oxidants.
Bacteriocins.
Receptor antagonism.
What are examples of co-operation microbial interactions ?
Metabolic products like saccharides, peptides, GFs.
Adhesion substrates.
Immune avoidance.
What are the three parts of the ecological plaque hypothesis ?
- Healthy plaque causing constraint and exclusion of pathogens.
- Environment modification made - change in commensal community and allow for overgrowth of pathogens.
- Co-aggregation or co-operation between different species, contributing to model.
What is Koch’s postulates (germ theory of disease) ?
Clinical sample collected.
Culture on agar and growth.
Introduced to animal.
Recapitulated from animal.
What type of pathogen is P. Gingivalis ?
Gram negative, non-motile, rod, strict anaerobe.
What type of pathogen is P. Gingivalis ?
Gram negative, non-motile, rod, strict anaerobe.
What are the 6 virulence factors of P. Gingivalis ?
Fimbriae - long and short.
Mixture of degradative enzymes.
Endotoxic, pro-inflammatory LPS.
Capsular polysaccharide and outer membrane vesicles.
Tissue toxic metabolic by-products i.e. ammonia, fatty acids, H2S.
Gingipains.
What is the function of long fimbriae ?
Initial attachment and biofilm organisation to surface.
What is the function of short fimbriae ?
Cell to cell auto-aggregation and micro-colony formation.
What are examples of degradative enzymes associated with periodontal disease ?
Collagenase, fibrolysin, phospholipase A.
What are the function of gingipains ?
Provides peptides i.e. nutrition.
Aid attachment.
Activate MMPs causing degradation and remodelling of tissue and degradation of innate receptors and cytokines (IL8).
Subversion of immune system.
What type of bacteria is A. Actinomyces ?
Gram negative, facultative anaerobe, non-motile.
What virulence factors make A. Actinomyces a periodontal pathogen ?
Production of leukotoxin - breaks up WBCs.
Membrane vesicles.
Glycoprotein matrix.
Fimbriae.
Phase variation i.e. changes antigens.
Subverts host cell immunity.
Bone resorption including factor.
What systemic disease risks can be associated with periodontal disease ?
Increased risk of CVD.
Increased risk of rheumatoid arthritis.
Increased risk (x6) of diabetes.
What form of periodontitis is P. gingivalis most likely to be associated with ?
Generalised chronic periodontitis.
What form of periodontitis is A. Actinomyces most likely to be associated with ?
Localised acute periodontitis.
