Periodontal Pathogens #5 Flashcards
T or F, Any accumulation of microorganisms at or below the gingival margin causes inflammation.
True!
T or F, All plaque bacteria is considered bad.
True
______ occurs when your mouth “recognizes a foe”
Ecological shift
Which is more important in disease concerning pathogen in the mouth, strains or species?
Strains
What are the prerequisites for disease initiation and progression with oral pathogens?
- Must express virulence factors
- Pathogen must be in the right location
- The local environment must not be to colonized by beneficial species (S.Sanguinis forms peroxide that inhibits pathogens)
- Host must be susceptible (immune compromised state)
What is Niche Saturation?
Primary colonizers saturate the realist and sub gingival sulcus (this is healthy) and prevent pathogen from colonizing there!
What are the 3 methods that help prevent pathogen colonization?
- Adhesins on bacteria bind to host receptors
- Coaggregation (nutrient utilization) = Veillonella uses lactate made by streptococci (these are found together and provide niche saturation)
- Competitive inhibition = bacteriocins are very nonspecific bactericide produced by bacteria. Also hydrogen peroxide production by S.Sanguinis inhibits A.a.
Why is A.a such a powerful bacteria?
Because it produces a very potent leukotoxin
How do pathogens overcome host defenses?
- Invade epithelium and bind to underlying cells (to prevent being sloughed off)
- IgG and IgA proteases and mimicking host antigens (to prevent antibodies from binding)
- Leukotoxin (A.a) and non-leathal suppression of immune (phagocytic cells)
Tell me about A.a….
- non motile
- gram negative
- Saccharolytic
- Capnophilic (needs co2)
- round ended rod
High numbers of A.a are associated with _______.
Agressive periodontitis
What are the Virulence factors of A.a?
- Tissue invasive (epithelial and endothelial)
- leukotoxins
- fibroblasts inhibiting factors
- Endotoxins
- Collagenase
High numbers of A.a are associated with _______.
Agressive periodontitis
What are the Virulence factors of A.a?
- Tissue invasive (epithelial and endothelial)
- leukotoxins
- fibroblasts inhibiting factors
- Endotoxins
- Collagenase
______ inhibits growth of A.a.
S. Sanguis (through peroxide production)
What Strains of A.a are most likely to cause disease?
A.a with 530 bp deletion is 23x more likely to be disease associated than A.a with full length promoter region!
Is A.a seen in all cases of Aggressive periodontitis?
No
Which serotype of A.a is associated with LAP (localized aggressive periodontitis)?
Serotype B *Serotype is based on polysaccharides on the surface of organism.
How many serotypes of A.a are there?
5
Which serotype of A.a is associated with LAP (localized aggressive periodontitis)?
Serotype B
Which serotype of A.a is associated with health?
Serotype A
What is Tx for A.a?
Amoxicillin 500mg + Metronidazole 250mg effective in reducing bacterial load.
- Surgical approach required to eliminate tissue reservoirs
Tell me about P. gingivalis…
- gram negative
- anaerobic
- asacharolyitc rods
- black pigmented bactericides
- Non Motile
- produces collagenase, proteases, endotoxins, fatty acids NH3, H2S and indole.
What are the Virulence factors of P. Gingivalis?
- Fimbriae, hemagglutinins , OMP’s and vesicles = all involved in colonization and attachment.
- lg and complement proteases, LPS, Capsule, = all involved in evading host responses.
- Proteinases, Hemolysins = involved in multiplying
- Proteinases, collagenous, trypsin-like activity, fibrinolytic, keratinolytic and other hydrolytic activities = involved in damaging host tissues and spreading.
T or F, P. Gingivalis is seen in health.
True, not always seen in disease either
What does the S-layer on T. Forsythia do?
- mediates adhesion
- Hemagglutination
Tell me about Tannerella Forsythia…
- Gram negative
- Anaerobic
- Spindle shaped
- Highly Pleomorphic rod
- Requires N acetylmuramic acid (NAM)
- Co-cultivates with F.Nucleatum
- *** Serrated S-layer on cell surface (famous Virulence factor)
What does the S-layer on T.Forsythia do?
- mediates adhesion
- Hemagglutination
What evidence is there for T. Forsythia as a pathogen?
- elevated presence in lesions of periodontitis
- Presence indicates increased risk for attachment loss
- It invades epithelial cells in vitro
- induces disease in rats
Tell me about Treponema Denticola…
- Gram negative
- Anaerobic
- Highly Motile
- Several different species that are hard to differentiate.
Tell me about Spirochetes…
- Gram negative
- anaerobic
- helical shaped
- 1st identified in ANUG
- Several different species that are hard to distinguish.
Tell me about Prevotella intermedia/nigrescens
- gram negative
- short round-ended rods
- anaerobic
- Black pigmented Bactericides
- Luxuriant growth in naphthoquinone
- Associated with puberty/pregnancy gingivitis
- Elevated in NUG.
What is the most commonly found pathogen in both remission and progression of periodontitis?
F. Nucleatum
Tell me about F. Nucleatum….
- Gram negative
- Anaerobic
- Spindle shaped rod
- early colonizer in plaque
- its a Bridging organism
- can induce cell death in leukocytes
- releases cytokines, elastase and oxygen radical from leukocytes
- Many strains, some cause disease and some don’t
What is the main Chair side microbial test?
Bana = test for Pd, Td, Fn
