Streptococcus Pyogenes

  1. Streptococcus pyogenes gram-positive or gram-negative
    Gram-positive
  2. Streptococcus pyogenes shape
    Cocci (pairs or chains)
  3. Streptococcus pyogenes motility
    Nonmotile
  4. Streptococcus pyogenes oxygen dependency
    Facultative anaerobe
  5. Streptococcus pyogenes catalase reactivity
    Catalase negative
  6. Streptococcus pyogenes fastidious or nonfastidious?
    Fastidious
  7. Streptococcus pyogenes growth media and requirements
    • Blood agar
    • Some are capnophilic (requires CO2)
  8. Streptococcus pyogenes capsule or no capsule?
    Capsule (hyaluronic acid)
  9. What is the capsule of Streptococcus pyogenes made of?
    Hyaluronic acid
  10. Streptococcus pyogenes hemolysis? If yes, what type?
    β-hemolytic
  11. Streptococcus pyogenes sensitivity to bacitracin?
    Yes
  12. What is the gold standard for Streptococcus pyogenes culture?
    On a blood plate, β-hemolysis and inhibited growth in presence of bacitracin
  13. Streptococcus pyogenes is AKA _______________
    Group A strep
  14. All streptococci have the same oxygen dependency and catalase reactivity. What are they?
    • Facultative anaerobe
    • Catalase negative
  15. Streptococcus pyogenes transmission usually from ___________________
    Humans (normal microbiota oropharynx)
  16. Transmission of Streptococcus pyogenes usually occurs via _______________
    Respiratory droplets, skin contact, formites
  17. Streptococcus pyogenes virulence factors
    SMASHED

    • Streptolysins S and O; SpyCEP
    • M protein
    • Against C5a (C5a peptidase)
    • Streptokinase
    • Hyaluronidase; hyaluronic acid capsule
    • Exotoxin B
    • DNAses A-D
  18. How does this Streptococcus pyogenes virulence factor increase its virulence: hyaluronic acid
    Poorly immunogenic (because we have it too)
  19. How does this Streptococcus pyogenes virulence factor increase its virulence: SpyCEP
    Cleaves IL-8 (prevents neutrophil recruitment)
  20. How does this Streptococcus pyogenes virulence factor increase its virulence: C5a peptidase
    Blocks phagocyte recruitment
  21. How does this Streptococcus pyogenes virulence factor increase its virulence: M protein
    Binds fibrinogen
  22. How does this Streptococcus pyogenes virulence factor increase its virulence: streptolysin S
    Nonimmunogenic
  23. How does this Streptococcus pyogenes virulence factor increase its virulence: streptolysin O
    Antigenic
  24. How does this Streptococcus pyogenes virulence factor increase its virulence: streptokinase
    Lysis of clots
  25. How does this Streptococcus pyogenes virulence factor increase its virulence: hyaluronidase
    Facilitates spread along fascial planes
  26. How does this Streptococcus pyogenes virulence factor increase its virulence: DNAses A-D
    Depolymerize free DNA in pus
  27. Common diseases caused by streptococcus pyogenes
    • PRINGLES
    • Pharyngitis, pneumonia
    • Rheumatic fever
    • Impetigo
    • Necrotizing fasciitis
    • Glomerulonephritis
    • Lymphangitis
    • Erysipelas, cellulitis
    • Scarlet fever, streptococcal TSS
Author
stepha998
ID
345458
Card Set
Streptococcus Pyogenes
Description
ATSU
Updated