Chlamydia pneumoniae — Flashcards

Flashcard 1: Chlamydia spp. cell walls lack _____

Answer: muramic acid

Flashcard 2: 1st stage of Chlamydia spp. life cycle: _____

Answer: elementary

Flashcard 3: What stain is used to visualize Chlamydia spp.?_____

Answer: Giemsa

Flashcard 4: 2nd stage of Chlamydia spp. life cycle: _____

Answer: Reticulate body

Flashcard 5: How is Mycoplasma pneumoniae transmitted?_____

Answer: Inhalation of droplets

Flashcard 6: Which form of Chlamydia spp. is infectious?_____

Answer: Elementary body

Flashcard 7: Name the clinical presentation, culture medium, and treatment for Mycoplasma pneumoniae.

Answer: • Clinical: Atypical "walking" pneumonia • Culture: Eaton's agar • Treatment: Macrolides or Fluoroquinolones

Extra: Note: Mycoplasma pneumoniae lacks a cell wall, making it naturally resistant to penicillins and cephalosporins. It is associated with high titers of cold agglutinins (IgM).

Flashcard 8: What are the key associations to remember for cold agglutinin?

Answer: IgM, Mycoplasma, Mononucleosis (EBV)

Flashcard 9: Mycoplasmal pneumonia (Most common cause)

Answer: Which organism is the most common cause of atypical pneumonia (walking pneumonia)?::Mycoplasma pneumoniae (Eaton agent)

Extra: • Features: Insidious onset, headache, nonproductive cough, and diffuse interstitial infiltrates. • Patient profile: Young adults (<30 y/o), military recruits, and prisoners. • Diagnosis: PCR, Cold agglutinins (IgM), culture on Eaton agar. • Treatment: Macrolides (e.g., Azithromycin), Doxycycline, or Fluoroquinolones. • Note: Lacks a cell wall (does not stain on Gram stain; resistant to β-lactams).

Flashcard 10: What factor explains Mycoplasma's inability to Gram stain?

Answer: no cell wall!