The Keystone Pathogen Hypothesis- Exam III Flashcards
states that certain low-abundance microbial pathogens can orchestrate inflammatory disease by remodeling a normally benign microbiota into a dysbiotic one.
Keystone pathogen hypothesis
The quest to identify specific periodontal pathogens has led to significant progress, including the identification of a number of candidates, mostly ___ the colonize ___.
gram-negative anaerobic bacteria; sub gingival tooth sites
In the quest to identify specific periodontal pathogens, three species have been identified which comprise the so-called _____, and are frequently isolated together and are strongly associated with ___.
red complex; diseases sites in mouth
What category of bacteria make up the “red complex”
gram-negative anaerobic bacteria
What is the red complex associated with?
disease sites in the mouth
The bacteria comprising the red complex are frequently:
isolated together
List the species of bacteria comprising the red complex:
- porphyromonas gingivalis
- treponema denticola
- tannerella forsythia
The Arg-specific cysteine proteinases (gingipains) of P. gingivalis exhibit:
complement C5 convertase-like activity
The complement C5 convertase-like activity of the Arg-specific cysteine proteinases (gingipains) generates high levels of ___ locally, to activate the:
C5a; C5a receptor on leukocytes
C5aR signaling is involved in crosswalks with:
TLR2
C5aR signaling is involved in crosswalks with TLR2 which is activated parallel by:
P. gingivalis surface ligands
C5aR signaling is involved in crosswalks with TLR2 which is activated parallel by P. gingivalis surface ligands and this crosstalk leads to:
enhanced inflammation but impaired leukocyte killing activity
P. gingivalis can also inhibit the synthesis of ___ by epithelial cells to delay the recruitment of neutrophils and facilitate its initial colonization of the periodontium.
IL-8
_____ can also inhibit the synthesis of IL8 by epithelial cells to delay the recruitment of neutrophils and facilitate its initial colonization of the periodontium.
P. gingival
P. gingivalis can also inhibit the synthesis of IL8 by epithelial cells to ______ and facilitate its initial colonization of the periodontium.
delay the recruitment of neutrophils
P. gingivalis can also inhibit the synthesis of IL8 by epithelial cells to delay the recruitment of neutrophils and facilitate its initial
colonization of the periodontium
The synthesis of ___ by the junctional gingival epithelium, adjacent to the tooth surface is thought to be an important feature of healthy periodontium
IL8
The synthesis of IL8 by the _____, adjacent to the tooth surface is thought to be an important feature of healthy periodontium
junctional gingival epithelium
The synthesis of IL8 by the junctional gingival epithelium, adjacent to the tooth surface is thought to be an important feature:
healthy periodontium
Why is the synthesis of IL8 by the junctional gingival epithelium, thought to be an important feature of healthy periodontium?
because it generates a gradient for recruitment of neutrophils into the gingival crevice
The subversion of leukocytes by _____ may allow uncontrolled growth of other species in the same biofilm
wild-type P. gingivalis
The subversion of leukocytes by P. gingivalis may allow uncontrolled growth of other species in the same biofilm.
This is consistent with the observed elevation of _____ following P. gingivalis colonization of the murine periodontium
total microbiota
Uncontrolled bacterial growth lead to:
enhanced complement-dependent destructive inflammation
Uncontrolled bacterial growth lead to enhanced complement-dependent destructive inflammation, which generates:
abundant tissue breakdown products
Uncontrolled bacterial growth lead to enhanced complement-dependent destructive inflammation, which generates abundant tissue breakdown products that serve the:
nutritional needs of bacteria
The inflammatory environmental changes can be better exploited by:
proteolytic and asacharolytic bacteria
Proteolytic and asacharolytic bacteria are associated with ____ rather than ____
periodontal disease; health
Specific removal of ____ from the periodontal biofilm (by means of a C5aR antagonist) reverse the dysbiotic changes , suggesting that dysbiotic diseases could be treated by specific targeting of keystone pathogens
P. Gingivalis
Specific removal of P. Gingivalis from the periodontal biofilm (by means of ______) reverse the dysbiotic changes , suggesting that dysbiotic diseases could be treated by specific targeting of keystone pathogens
C5aR antagonist
What results with specific removal of P.Gingivalis from the periodontal biofilm (by means of a C5aR antagonist) ?
reversal of dysbiotic changes
Specific removal of P. Gingivalis from the periodontal biofilm (by means of C5aR) reverse the dysbiotic changes:
What does this suggest?
that dysbiotic diseases could be treated by specific targeting of keystone pathogens
Despite its low-level colonization of the periodontium, P. gingivalis causes ____ through ___
inflammatory periodontitis through dysbiosis