Oral Microbiology

  1. What are the major SUPRAgingival bacteria in the oral cavity? (4)
    streptococci species: mutans, salivarius, angiosus, and mitis
  2. What are the major bacteria found in SUBgingival plaque? (4)
    actinomyces, porphyromonas, fusobacterium, veillonella
  3. ___ ___ contribute significantly to the development of dental caries
    Mutans streptococci
  4. 6 species in Mutans Streptococci
    • S. mutans
    • S. sobrinus
    • S. ratti
    • S. criceti
    • S. downei
    • S. macacae
  5. Saliva can be good for bacteria because it provides the pellicle, which does what?
    it facilitates bacterial adhesion
  6. Saliva provides what for bacteria?
  7. Saliva can inhibit the growth of bacteria thorough non-specific factors such as (2)
    • lysozyme--> involved in the lysis of bacteria
    • lactoferrin--> sequesters iron
  8. Saliva can inhibit the growth of bacteria thorough specific factors such as (2)
    • IgA
    • Other Immunoglobulins
  9. What antimicrobial does saliva produce through the sialoperoxidase system?
    Hypothiocyanite (OSCN-)
  10. Saliva can aggregate bacteria--> how is this good and bad for the bacteria?
    • Bad: can result in the clearance of bacteria from mouth
    • Good: can results in the deposition of bacteria on certain surfaces
  11. What 4 inter and intraspecies processes do oral microbes engage in that can promote and suppress the growth of other microbes
    • Competition for receptors for adhesion 
    • Production of bacteriocins that can kill other microbes
    • Production of metabolic end-products, which can intoxicate other bacteria
    • utilization of metabolic end-products of other bacteria as nutrients
  12. T/F: dental plaque biofilms are a community composed of the same microbe
    False--> different microbes
  13. T/F: biofilms contain only living microbes
    FALSE--> it contains living as well as dead and dying microbes
  14. T/F: plaque can be found on hard AND soft tissue surfaces of the mouth
  15. ___ biofilms microbes display greater resistance to antimicrobials than ____
    • sessile (encased in a biofilm)
    • planktonic (free-living forms)
  16. What three bacteria (other than S. mutants) play a role in dental caries (cariogenic)
    • Lactobacilli
    • Actinomyces
    • Veillonella
  17. Cariogenic flora are characterized by what three things
    • acidogenicity--> metabolizes sugar to acids 
    • aciduricty--> tolerates conditions of low pH
    • ability to synthesize extracellular and intracellular polysaccharides
  18. saliva can modulate the growth of bacteria through its maintenance of ____
  19. what bacteria extracellular enzymes convert sucrose to glucose and fructose?
    glucosyl and fructosyl transferase
  20. glucose and fructose are concerted to ___ and ____ with are utilized as a major food source but the bacteria and also as components of plaque matrix
    Glucans and fructans
  21. high caries risk might correlate with greater than ______ S. mutans colony forming units per mL of saliva and greater than ____ lactobacillus CFU per mL of saliva
    • one million
    • 100,000
  22. gingival health is characterized by mainly what bacteria?
    Gram-positive aerobic cocci (with fewer than 5% of organisms being spirochetes and motile rods)
  23. With increasing severity of gingival disease, there is an increase in proportions of what bacteria?
    Strict anaerobic, gram-negative and motile bacteria
  24. 5 bacteria associated with a healthy gingival sulcus
    • Strep sanguis
    • Strep oralis
    • Actinomyces naeslundi
    • Actinomyces viscosus
    • Veillonella
  25. 4 bacteria associated with aggressive periodontitis
    • Actinobacillus actinomycetemcomitans
    • Capnocytophaga
    • Porphyporymonas gingivalis 
    • Prevotella intermedia
  26. What 2 microbes are associated with necrotizing ulcerative gingivitis (NUG)--anaerobic polymicrobial infection
    • Fusobacterium nucleatum
    • Spirochetes
  27. 5 ways to test for presence of possible peridontopathogens
    • Direct microscopy 
    • microbial cultures
    • biochemical testing
    • immunological testing
    • molecular methods
Card Set
Oral Microbiology
Immunology Exam 3 Material