L31 - Gram- Bacteria I Flashcards Preview

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Flashcards in L31 - Gram- Bacteria I Deck (10):
1

Neisseria gonorrhoeae

microbiology

  • Gram-
  • Cocci (chains or pairs)
  • Grows best on chocolate agar
  • Outer membrane
    • LOS
    • Porins: allow for flow of water
    • Opa proteins: adherence between gonococci
    • Reduction-modifiable proteins: stimulate blocking antibodies that reduce bactericidal activity of serum
    • Pili: resistance against neutrophils and increased adherence to mucosal cells

2

Neisseria gonorrhoeae

clinical manifestations

  • Urethral discharge
  • Fitz-Hugh-Curtis Syndrome
    • Acute perihepatitis caused by spread of infection from fallopian tube
    • Right upper quadrant pain
  • Septic Arthritis

3

Neiserria meningitidis

microbiology

  • Gram- diplococcus
  • Non-hemolytic
  • Outer membrane
    • LOS
    • Proteins that scavenge iron from hemoglobin, transferrin, and lactoferrin

4

Neiserria meningitidis

pathogenesis

  • Exposure to pathogenic strain
    • Humans are only natural reservoir
    • Transfer via aerosol or secretions
  • Colonization of nasopharyngeal mucosa
    • Pili attach to mucosal cells (non-ciliated columnar cells)
    • Opa and Opc bind to host cell receptors which stimulate engulfment
  • Passage through mucosa
    • Few bacteria survive this process
  • Survival in bloodstream
    • Polysaccharide capsule (protects against complement and neutrophilic phagocytosis)
    • Alternative complement provides some protection

5

Neiserria meningitidis

clinical manifestations

  • Endotoxin causes cytokine production
  • Petechiae (skin)
  • Photosensitivity
  • Neck stiffness

6

  • Gram-
  • Cocci (chains or pairs)
  • Grows best on chocolate agar
  • Outer membrane
    • LOS
    • Porins: allow for flow of water
    • Opa proteins: adherence between gonococci
    • Reduction-modifiable proteins: stimulate blocking antibodies that reduce bactericidal activity of serum
    • Pili: resistance against neutrophils and increased adherence to mucosal cells

Neisseria gonorrhoeae

microbiology

7

  • Urethral discharge
  • Fitz-Hugh-Curtis Syndrome
    • Acute perihepatitis caused by spread of infection from fallopian tube
    • Right upper quadrant pain
  • Septic Arthritis

Neisseria gonorrhoeae

clinical manifestations

8

  • Gram- diplococcus
  • Non-hemolytic
  • Outer membrane
    • LOS
    • Proteins that scavenge iron from hemoglobin, transferrin, and lactoferrin

Neiserria meningitidis

microbiology

9

  • Exposure to pathogenic strain
    • Humans are only natural reservoir
    • Transfer via aerosol or secretions
  • Colonization of nasopharyngeal mucosa
    • Pili attach to mucosal cells (non-ciliated columnar cells)
    • Opa and Opc bind to host cell receptors which stimulate engulfment
  • Passage through mucosa
    • Few bacteria survive this process
  • Survival in bloodstream
    • Polysaccharide capsule (protects against complement and neutrophilic phagocytosis)
    • Alternative complement provides some protection

Neiserria meningitidis

pathogenesis

10

  • Endotoxin causes cytokine production
  • Petechiae (skin)
  • Photosensitivity
  • Neck stiffness

Neiserria meningitidis

clinical manifestations