Chlamydia_Mycoplasma_Rickettsia

• What family do Chlamydia and Chlamydophila belong to?

  Family Chlamydiaceae
• Name the two genera in the family Chlamydiaceae.

  Chlamydia and Chlamydophila
• Which species of Chlamydia is responsible for human disease?

  Chlamydia trachomatis
• What are the three species responsible for human disease in the Chlamydiaceae family?

  Chlamydia trachomatis, Chlamydophila psittaci, Chlamydophila pneumoniae
• Why were Chlamydia considered viruses in the past?

  They can pass through 0.45 μm filters
• What membranes do Chlamydia possess?

  Inner and outer membranes like gram-negative bacteria
• What do Chlamydia lack that is typical in bacteria?

  A rigid peptidoglycan layer
• What types of nucleic acids do Chlamydia contain?

  Both DNA and RNA
• What type of ribosomes do Chlamydia possess?

  Prokaryotic ribosomes
• What can Chlamydia synthesize?

  Proteins, nucleic acids, and lipids
• What are Chlamydia susceptible to?

  Numerous antibacterial antibiotics
• What is the unique developmental cycle of Chlamydia?

  • Infectious forms: elementary bodies (EBs)
  • Metabolically active forms: reticulate bodies (RBs)
  • EBs bind to host cells and stimulate uptake
  • RBs replicate and convert back to EBs
• What is the major outer membrane protein in Chlamydia called?

  Major outer membrane protein (MOMP)
• How many serologic variants does MOMP have?

  18 serologic variants (serovars)
• What are elementary bodies in Chlamydia?

  Infectious form that cannot replicate
• What do elementary bodies do upon entering a host cell?

  They convert into reticulate bodies
• How long after infection do reticulate bodies begin to reorganize into elementary bodies?

  Approximately 18 to 24 hours
• What happens to the host cell after 48 to 72 hours of Chlamydia infection?

  The cell ruptures and releases bacteria
• Are C. trachomatis infections restricted to humans?

  Yes, restricted to humans
• What are the two biovars of C. trachomatis responsible for human disease?

  Trachoma and LGV
• What types of cells are susceptible to Chlamydial infections?

  Epithelial cells on mucous membranes
• What causes the clinical manifestations of chlamydial infections?

  Direct destruction of cells and cytokine response
• Where is C. trachomatis found worldwide?

  Yes, it is found worldwide
• What is the leading cause of preventable blindness?

  Trachoma
• How is trachoma transmitted?

  Eye-to-eye by droplet and hands
• Who are the major reservoirs of C. trachomatis in endemic areas?

  Children
• What is the incubation period for neonatal conjunctivitis?

  5 to 12 days after exposure
• What is a distinctive symptom of infant pneumonia caused by C. trachomatis?

  A staccato cough
• What percentage of genital tract infections in women are asymptomatic?

  As many as 80%
• What is the incubation period for lymphogranuloma venereum?

  1 to 4 weeks
• What is the primary lesion in lymphogranuloma venereum?

  A small, painless lesion
• What are systemic manifestations of lymphogranuloma venereum?

  Fever, chills, and myalgias
• What is the most specific method for diagnosing C. trachomatis infections?

  Cultivation
• What is the sensitivity of culture compared to nucleic acid amplification techniques?

  Relatively insensitive
• What is the role of nucleic acid amplification tests (NAATs)?

  More sensitive for detecting infections
• What is the value of ELISA in diagnosing C. trachomatis infections?

  Limited value in adults
• What is the treatment for patients with LGV?

  Doxycycline for 21 days
• What is the recommended treatment for children younger than 9 years?

  Erythromycin
• What is the prevention method for trachoma-related blindness?

  Prompt treatment of early disease
• What is the only serotype identified in Chlamydophila pneumoniae?

  Only a single serotype