Chlamydia and Rickettsia

Question 1

What taxonomy is Chlamydiaceae?

Answer 1

• Phylogeny

Question 2

What are the two genera of Chlamydiaceae?

Answer 2

• Chlamydia and Chlamydophila

Question 3

What are the two Chlamydal Morphologies

Answer 3

• Elementary bodies (EB)
• Reticular bodies (RB)

Question 4

What are Elementary bodies?

Answer 4

• infectious form, metabolically inactive, electron dense, nucleoid, granular cytoplasm, spherical, approx 0.2-0.3 microns in diameter
• one of the chlamydial morphologies

Question 5

What are Reticular bodies (RB)

Answer 5

• intracellular reproductive form, metabolically active, chromatin dispersed (transcription)
• approx 0.5-2 microns in diameter, can divide by binary fission resulting in new RBs
• chlamydial morphologies

Question 6

What are the general features of Chlamydiaceae

Answer 6

• Non-motile, obligate intracellular coccoid bacilli
• inhabit epithelial cells/macrophages
• energy parasites: lack ATP-generating ability and must obtain from host cell

Question 7

What is the most common preventable cause of blindness

Answer 7

• Chlamydia trachomatis

Question 8

What is Chlamyda Trachomatis types A, B and C

Answer 8

• Infection of conjunctival epithelial cells, repeated clinical/subclinical infection and cell infiltration can cause cornea to cloud/scar

Question 9

How is Chlamydia Trachomatis types A, B and C transmitted

Answer 9

• by flies, fomites, touch

Question 10

A Patient lives in a HOT, DRY CLIMATE and has symptoms on their eyes such as CORNEAL OPACITY, TRACHOMATOUS SCARRING and TRACHOMATOUS TRICHIASIS, what specific disease does he have

Answer 10

• Chlamydia Trachomatis types A, B , C

Question 11

What are the two different forms of Chlamydia Trachomatis Types D to K

Answer 11

• Neonatal and Adult form

Question 12

Explain the neonatal form of Chlamydia trachomatis

Answer 12

• Inclusion blenorrhoea can develop when infant is in birth canal and appears 5-12 days after birth
• can precede infant pneumonia (can also develop independenty)

Question 13

Explain the adult form of chlamydia trachomatis

Answer 13

• Associated with sexual contact via STD form, also from swimming pools contaminated with chlamydia from genital secretions (“swimming pool conjunctivitis”)

Question 14

Explain the Genital chlamydiasis in men

Answer 14

• urethritis (NGU), 7-28 days after infection, mild burning, more frequent need to urinate, white discharge from penis

Question 15

Explain the Genital chlaydiasis in women

Answer 15

• Urethritis, cervicitis, PID, infertility, ectopic pregnancy, premature delivery, postpartum fever, LGV

Question 16

What causes parrot fever

Answer 16

• Chamydia psittaci

Question 17

What are the risk groups for parrot fever

Answer 17

• occupational disease, pigeon farmers, pet shop owners, veterinarians, poultry workers etc

Question 18

What taxonomy is Rickettsiae?

Answer 18

• Phylogeny

Question 18

What taxonomy is Rickettsia

Answer 18

• genera

Question 19

What is Typhus caused by

Answer 19

• Rickettsia prowazekii

Question 20

Patient x has been infected by a disease by faeces. after 7-14 days, patient x suffers from hgih fever, chills, headaches, and a coma, what disease does he have

Answer 20

• Typhus

Question 21

What is the difference between Typhus and Typhoid

Answer 21

• Typhus: caused by Rickettsia typhi or proowzekii. Vectors: flea, Prevention: good hygiene and insect repellants, insecticides
• Typhoid: caused by Salmonella typhi. Vectors: contaminated food, Prevention: good hygiene, vaccine