Chlamydial Infections

Question 1

Chlamydiae

Answer 1

• obligate intracellular parasites
• smaller than most other bacteria
• cannot generate ATP, must hijack host to reproduce
  LIFE CYCLE with ELEMENTARY BODY - metabolically inactive form
  RETICULATE BODY - metabolically active, divides repeatedly and destroys host cell

Question 2

C. trachomatis STI

Answer 2

• serovars D-K
• men - urethritis, epididymitis, proctitis
• women - cervicitis, endometritis, salpingitis, PID
• spread in genital secretions
• asymptomatic causes large reservoir for transmission
• causes conjunctivitis in newborns
• infiltrate of neutrophils and lymphocytes

Question 3

C. trachomatis - Lymphogranuloma venereum

Answer 3

• Serovars L1-L3
• begins as genital ulcer then spreads to lymph nodes
• enters through skin break
• necrotizing lymphadenitis develops 1-3 weeks after primary lesion

Question 4

C. trachomatis - Trachoma

Answer 4

• leading cause of blindness in many developing countries
• serovars A, B, Ba, C
• progressive scars of conjunctiva and cornea
• reproduction in conjunctival epithelium, inciting inflammatory infiltrate

Question 5

C. psittaci - Psittacosis/ornithosis

Answer 5

• self-limited pneumonia transferred to humans from birds
• humans inhale infectious particles from feathers
• infects pulmonary macrophages and travels to liver and spleen where it reproduces and is distributed by bloodstream
• interstitial pneumonia
• tx with tetracycline

Question 6

C. pneumoniae

Answer 6

• acute, self-limited mild RTI
• transmitted person to person
• only 10% infections cause clinical pneumonia