Week 2

• Who is the lecturer in Bacteriology mentioned in the study material?

  Dr. Suzie Hingley-Wilson
• What are the learning objectives of the study material?


  • Impact and aetiology of Chlamydia sp (e.g., C. trachomatis)
  • Impact and aetiology of Rickettsia sp (e.g., Rickettsia prowazekii)
  • Understand their unique life cycle and intracellular survival
• What family did Chlamydia and Chlamydophila once belong to?


  They once belonged to the same family.
• What is the single genus that Chlamydia and Chlamydophila are classified under now?


  Chlamydia
• Name one example of Chlamydia sp that causes ocular and genital infections.


  1. trachomatis
• What is the disease caused by C. psittaci?


  Psittacosis
• What percentage of community-acquired pneumonia (CAP) is attributed to C. pneumoniae?


  10-20%
• What is the elementary body (EB) in Chlamydia?


  It is the infectious form that is metabolically inactive.
• What is the approximate size of the elementary bodies (EB) in Chlamydia?


  Approximately 0.2-0.3 microns in diameter
• What are reticular bodies (RB) in Chlamydia?


  They are the intracellular reproductive form that is metabolically active.
• What is the size range of reticular bodies (RB) in Chlamydia?


  Approximately 0.5-2 microns in diameter
• How do reticular bodies (RB) reproduce?


  They can divide by binary fission.
• What type of cells do Chlamydia inhabit?


  Epithelial cells and macrophages
• Why are Chlamydia small enough to pass through 0.45 micron filters?


  Because they are non-motile, obligate intracellular coccoid bacilli.
• What is the significance of peptidoglycan in Chlamydia?


  Its existence was debated until a new metabolic cell-wall labeling method revealed it in C. trachomatis.
• What type of pathogens are Chlamydia classified as?


  Obligate intracellular pathogens
• What is the public health impact of Chlamydia?


  It is responsible for blindness or visual impairment in about 1.9 million people.
• How many people live in trachoma endemic areas?


  142 million people
• What does the SAFE strategy stand for in relation to trachoma prevention?

  • Surgery
  • Antibiotics
  • Facial cleanliness
  • Environmental improvement
• How many people received surgery for trachoma in 2018?


  146,112 people
• What was the global-level antibiotic coverage for trachoma in 2018?


  50%
• What is the most common preventable cause of blindness?

  Chlamydia trachomatis
• What types of infections does Trachoma (types A, B, and C) cause?


  Infection of conjunctival epithelial cells
• What can repeated clinical/subclinical infection of Trachoma lead to?


  Clouding or scarring of the cornea
• How is Trachoma transmitted?


  By flies, fomites, and touch
• What type of climate does Trachoma favor?


  Hot, dry climates
• What is inclusion conjunctivitis associated with?


  Sexual contact and contaminated swimming pools
• What is the neonatal form of inclusion conjunctivitis?


  It can develop when an infant is in the birth canal.
• What can inclusion conjunctivitis precede in infants?


  Infant pneumonia
• What are the symptoms of genital chlamydiasis in men?


  Urethritis, mild burning, and white discharge from the penis
• What are the symptoms of genital chlamydiasis in women?


  Urethritis, cervicitis, PID, and infertility
• What is psittacosis also known as?


  Parrot fever
• From how many avian species has Chlamydia psittaci been isolated?


  Over 100 avian species
• How long can the elementary bodies (EB) of Chlamydia psittaci remain resistant in feed?


  Up to 2 months
• What is the typical time frame for symptoms to develop in patients with psittacosis?


  Most patients develop symptoms after 10 days
• What is the range of severity for clinical signs of psittacosis?


  From non-apparent to severe pneumonia
• Who are at risk for psittacosis?


  Pigeon farmers, pet shop owners, veterinarians, and poultry workers
• What are the four genera of Rickettsia mentioned in the study material?


  • Rickettsia
  • Orientia
  • Coxiella
  • Erlichia
• What type of pathogens are Rickettsiae classified as?


  Obligate intracellular pathogens
• What is the size of Rickettsiae?


  0.3 by 1-2 microns