Chlamydia

Question 1

Describe Chlamydia Trachomatis

Answer 1

Obligate intracellular pathogen, Gram- cell envelope but no PG; Does not synthesized amino acids. Can synthesize ATP.

Question 2

What are the two cell types of Chlamydia Trachomatis?

Answer 2

1. Elementary body: Hardy,extracellular form, non replicative, infectious.
2. Reticulate body: Fragile, metabolically active and replicative; Can’t survive extracellularly

Question 3

What is the development cycle of Chlamydia Trachomatis?

Answer 3

Dormant phase, Entry, Elementary body to Replicative body development, RB multiplication, RB to EB development, Exit.

Question 4

What type of cell does C. Trachomatis typically infect?

Answer 4

Non-ciliated mucoal epithelial cells or monocytes.

Question 5

Describe how C. trachomatis adheres to objects.

Answer 5

Cell receptors include heparin sulfate, estrogen receptor complex. Translocated Actin Recruiting Protein (TARP) secreted EB into target cell.

Question 6

How is C. trachomatis taken into the cell?

Answer 6

1. Endocytosis via receptor mediated or clathrin-coated pits.
2. Pinocytosis via non-clathrin coated pits.
3. Phagocytosis

Question 7

Describe the EB to RB transition in C. Trachomatis

Answer 7

Chlamydial gene expression, ATP stored in EB, Diverts endosome from endocytic to exocytic pathway.

Question 8

What are the consequences of diverting the endosome from endocytic to exocytic?

Answer 8

No fusion with lysosome, pH drops to 6.6, No antigen processing, steals sphyngomyeling from golgi to make vesicle for RB membrane

Question 9

Describe C. trachomatis’ modification of vacuoles.

Answer 9

Brings vacuole near the host cell nucleus; Signaling between vacuoles containing bacteria (Communication). There RB specific proteins IncA-G; IncA phosphorylated by host cell, needed for vacuole fusion.

Question 10

Describe RB metabolism

Answer 10

Growing RBs line up around periphery of inclusion taking nutrients from host across vesicle membrane; Can produce ATP. Contains glycolytic and PPP pathways.

Question 11

Describe the transition from RB to EB.

Answer 11

Newly formed EBs migrate to center of inclusion.

Question 12

Describe the exit process of C. trachomatis.

Answer 12

Destruction of vacuolar membrane or fusion of vacuole with host CM; RBs in vacuole die.

Question 13

What are the symptoms of C.trachomatis?

Answer 13

1. Trachoma; mucopurulent discharge in eyes.
2. Cervicitis or urethritis; purulent discharge.
3. Lymphogranuloma venereum (LGV); painless genital lesions, swollen lymph nodes

Question 14

What causes the symptoms of C. trachomatis?

Answer 14

LPS, production of Tnf-alpha, IL-1 & 8

Question 15

Describe LGV

Answer 15

Inflammation of draining lymph node; Painful

Question 16

Describe Trachomas

Answer 16

Chronic follicular or keratinous conjunctivitis; Repeated infection can lead to blindness.

Question 17

How do most men present with C. trachomatis?

Answer 17

Uncomplicated urethritis; can spread to epididymitis, prostatitis.

Question 18

How do most women present with C. trachomatis?

Answer 18

Vaginitis, cerivicitis; Can be asymptomatic and lead to ectopic pregnancy or Pelvic Inflammatory disease.

Question 19

How does C. trachomatis affect infacts and unborn children?

Answer 19

Can infect infant during birth from infected mother; Neonatal conjunctivitis, pneumonia about 2 weeks after birth.

Question 20

How is C. trachomatis diagnosed?

Answer 20

Obtain via cervical or urethra scrapping, culture it, detect antigen via immunofluorescence, DNA-test via PCR.

Question 21

How is C. trachomatis treated?

Answer 21

Antibiotics; doxycycline. Azithromycin for children and pregnant women. Trichiasis is corrected via surgery.