Perio Microbio Flashcards
What are the stages of biofilm development?
Adhesion of pioneer bacteria
Colonisation
Accumulation
Complex community formed
Dispersal
Important MO’s in healthy oral cavity?
Oral streptococci
Actinomyces
Fusobacterium
Veillonella
Important MOs in gingivitis?
Actinomyces
Prevotella intermedia
Fusobacterium nucleatum
Important MO’s in periodontitis?
Porphyromas gingivalis
Treponema denticola
Tannerella forsythia
Prevotella intermedia
Socransky model red species for perio?
P gingivalis
T denticola
T forsythia
What is p gingivalis?
Gram negative
Non-motile rod
Strict anaerobe
P gingivalis virulence factors?
Host tissue adherance and invasion
- with fimbrillar adhesions
- long fimbriae = initial attachment
- short fimbriae = cell to cell adhesion
Elaboration of proteases - degradative enzymes
- collagen are
- fibrinolytic etc
Endotoxins - LPS
Capsular polysaccharide
- protection vs host immune cells
outer membrane vesicles
- deliver virulence factors / toxins to host cell
Tissue toxic metabolic by-products
- ammonia
- fatty acids
How does p gingivalis evade and manipulate host defences?
Formation of biofilm
Gingipains
- degrade innate immune cell receptors
- degrades cytokines
Induce tissue destruction
- activation of MMPs
