Mycoplasma Pneumoniae

Question 1

Mycoplasma Pneumoniae
Disease

Answer 1

• Atypical pneumonia.

Question 2

Mycoplasma Pneumoniae
Characteristics

Answer 2

• Smallest free-living organisms.
• No cell wall-> poor Gram-stain
• Penicillins & cephalosporins not effective-> no peptidoglycan
• cholesterol in cell membrane.
• cultured in vitro-> colony fried-egg shape

Question 3

Mycoplasma Pneumoniae
Habitat & Transmission

Answer 3

• Human respiratory tract-> respiratory droplets.

Question 4

Mycoplasma Pneumoniae
Pathogenesis & Clinical Findings

Answer 4

• No exotoxins & endotoxin (no cell wall).
• Produces hydrogen peroxide-> damages respiratory tract.
• nonproductive cough, sore throat, or earache-> whitish, nonbloody sputum->fever, headache, malaise, & myalgias.
• pneumonia or bronchitis
• resolves spontaneously in 10 to 14 days.
• extrapulmonary manifestations-> Stevens-
  Johnson syndrome, erythema multiforme, Raynaud’s phenomenon, cardiac arrhythmias, arthralgias, hemolytic anemia, & neurologic manifestations (Guillain-
  Barré syndrome).

Question 5

Mycoplasma Pneumoniae
Laboratory Diagnosis

Answer 5

• Gram stain not useful.
• Cultured takes 10 days-> too long
• Positive cold–agglutinin test-> Cold
  agglutinins are IgM autoantibodies against type O rbc’s that agglutinate cells at 4°C not at
  37°C.
• Complement fixation test for antibodies-> specific

Question 5

Mycoplasma Pneumoniae
Treatment & Prevention

Answer 5

• Azithromycin or doxycycline.
• No vaccine