L31 - Gram- Bacteria I

Question 1

Neisseria gonorrhoeae

microbiology

Answer 1

• 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

Question 2

Neisseria gonorrhoeae

clinical manifestations

Answer 2

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

Question 3

Neiserria meningitidis

microbiology

Answer 3

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

Question 4

Neiserria meningitidis

pathogenesis

Answer 4

• 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

Question 5

Neiserria meningitidis

clinical manifestations

Answer 5

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

Question 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

Answer 6

Neisseria gonorrhoeae

microbiology

Question 7

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

Answer 7

Neisseria gonorrhoeae

clinical manifestations

Question 8

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

Answer 8

Neiserria meningitidis

microbiology

Question 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

Answer 9

Neiserria meningitidis

pathogenesis

Question 10

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

Answer 10

Neiserria meningitidis

clinical manifestations