Biofilm II - Periodontitis Flashcards
What different factors can influence the oral microflora?
Host factors
Diet
Saliva
Gingival crevicular fluid - antimicrobial components
Gaseous environment - O2 concentrations
Give examples of host factors which affect the oral microflora?
Smoking/tobacco use
Genetics
Pregnancy/puberty
Systemic diseases
Nutrition
Give examples of important microorganisms in oral health
Oral streptococci
Actinomyces
Veillonella
Give examples of important microorganisms in gingivitis
Acinomyces
P. intermedia
Bacteroids
Give examples of some important microorganisms in periodontitis?
P. gingivalis
T. forsythia
T. denticola
P. intermedia
What types of microbial interactions occur in the mouth?
Competition (dominance)
Co-operation (integration)
Describe P. gingivalis levels in periodontitis
Keystone pathogen
Gram negative
Increased numbers in periodontitis
Suppressed or undetectable in successfully treated lesions
What virulence factors does P. gingivalis have?
Fimbriae
Proteases - degradation enzymes
Endotoxins
Capsular polysaccharide and outer membrane vesicles
Tissue toxic metabolic by-products
What are fimbrillar adhesins?
Help invade membrane vesicle of host cells by binding to cellular integrins
Can be long fimbriae or short fimbriae
What are gingipains?
They provide peptides from heme - giving nutrition
They activate MMPs
How can P. gingivalis manipulate host defences?
It forms a biofilm
Gingipains degredate innate receptors and cytokines
Induction of tissue destruction through MMPs
Subversion - tricks the hosts immunity
What does A.a. produce?
Leukotoxin
Cytotoxin
LPS
Fimbriae
