Genus Coxiella: Coxiella burnetii

• What type of bacteria is Coxiella burnetti?

  Gram-negative
• What is a key characteristic of Coxiella burnetti regarding its living conditions?

  It is an obligate intracellular bacteria
• How does Coxiella burnetti survive in harsh environments?

  It is extremely resistant to heat and drying
• What disease does Coxiella burnetti cause?

  Q Fever
• How can Coxiella burnetti be distinguished from Rickettsia?

  • Grows in cytoplasmic vacuoles
  • Stimulated by low pH of phagolysosome
  • Resistant to degradative enzymes
  • Extremely resistant to heat and drying
• What are the main reservoirs for Coxiella burnetti?

  Cattle, sheep, and goats
• How is Coxiella burnetti transmitted?

  Aerosol transmission
• What are the virulence factors of Coxiella burnetti?

  • Escapes macrophage phagocytosis
  • Produces superoxide dismutase
  • Inhibits cathepsin fusion
  • Develops Phase I and Phase II antigens
• What is the role of superoxide dismutase in Coxiella burnetti's virulence?

  It inactivates phagosomal enzymes
• What is the significance of Phase I antigens in Coxiella burnetti?

  They indicate high infectiousness
• How do Phase II antigens differ from Phase I antigens in Coxiella burnetti?

  Phase II antigens are less infectious
• What does antigenic shift indicate in Coxiella burnetti infections?

  It differentiates acute from chronic Q fever
• What are the clinical manifestations of Q Fever caused by Coxiella burnetti?

  • Interstitial pneumonia
  • Hepatitis
  • Myocarditis
  • Encephalitis
• What is a common method for microbiological diagnosis of Q Fever?

  Serologic assays
• What is the treatment for Q Fever?

  Doxycycline
• What is a preventive measure for Q Fever?

  Pasteurize milk products