CHLAMYDIA

Question 1

Chlamydiae can survive for long periods in the soil and feces. True or False?

Answer 1

True

Question 2

Chlamydophila suis induces what ds.?

Answer 2

• Intestinal infections in pigs

Question 3

Describe the morphology of Chlamydiae spp.

Answer 3

• Non-motile
• Gram-negative
• Pleomorphic
• Obligate intracellular parasite

Question 4

Chlamydia felis induces what ds.?

Answer 4

• Conjuctivitis (feline pneumonitis)

Question 5

Chlamydia has 2 stages/forms. What are these and give their corresponding “bodies”?

Answer 5

1. Infectious forms - elementary bodies
2. Intracytoplasmic forms - reticulate bodies

Question 6

Identify the phase of chlamydial life cycle with the given data:

• Induction of metabolic activities with elementary bodies
• Activity stimulated by uptake of elementary body by host cell
• Once phagocytosed, they form intracytoplasmic, membrane-limited inclusions within the phagocytic vacuole

Answer 6

Phase 2

Question 7

Chlamydia is resistant to many antibiotics. True or False?

Answer 7

False, susceptible to broad-spectrum antibiotics

Question 8

Identify the phase of chlamydial life cycle with the given data:

• Characterized by reversion of the mature reticulate bodies back into elementary bodies which occurs within 20 to 30 hours after replication
• Forty to 60 hours following replication, the host cell lyses and releases new elementary bodies capable of infecting more host cell

Answer 8

Phase 4

Question 9

Identify the phase of chlamydial life cycle with the given data:

• Elementary bodies before uptake by target cell (dormant phase)
• During initial infection or release of infectious particles from lysed host cell
• Elementary bodies have very little metabolic activity during this time

Answer 9

Phase 1

Question 10

Chlamydophila pneumoniae induces what ds.?

Answer 10

• Respiratory infections in humans
• Horses - respiratory infections
• Koalas- conjunctivitis
  *** One serovar

Question 11

Identify the phase of chlamydial life cycle with the given data:

• Characterized by transformation of elementary bodies into non-infectious
• Transformation is result of nucleoid dispersion
• Reticulate body enlarges in diameter to 0.5-0.6 um -> 10 to 15 hours later, reticulate bodies divide by binary fission

Answer 11

Phase 3

Question 12

Chlamydia have toxins. True or False?

Answer 12

False

Question 13

Chlamydia trachomatis induces what ds.?

Answer 13

• Trachoma
• Inclusion conjunctivitis in humans
• Lymphogranuloma venereum
• Other genital tract infections
• Proctitis in humans
  ** Many serovars
  ** Organism have also been isolated from swine and ferrets

Question 14

Chlamydophila pecorum induces what ds.?

Answer 14

Recovered from cattle and sheep
* Sporadic bovine encephalitis
* Infectious polyarthritis
* Pneumonia and diarrhea

Question 15

Chlamydophila caviae induces what ds.?

Answer 15

• Inclusion conjunctivitis in guinea pigs

Question 16

Chlamydophila abortus induces what ds.?

Answer 16

• Enzootic abortion of sheep and goats
• Chlamydial abortion in cattle, pigs, and goats

Question 17

There are 4 phases of chlamydial life cycle. What event does it start with?

Answer 17

• Life cycle begins as highly infectious elementary bodies capable of entering host epithelial, mucosal, or phagocytic cells via phagocytosis
• Elementary bodies spherical and approximatelyn0.25um in diameter

Question 18

Chlamydia is metabolically capable of hydrolyzing glucose, pyruvate, and glutamate. True or False?

Answer 18

True

Question 19

Chlamydia spp. infect the mucous membranes of ?

Answer 19

Respiratory system and gastrointestinal tracts of normal animals including avian species.

Question 20

Chlamydia have both RNA and DNA. True or False?

Answer 20

True

Question 21

Chlamydophila psitacci induces what ds.?

Answer 21

• Avian chlamydiosis
• Bovine abortion
• Psittacosis in humans

Question 22

Give the pathogenesis of Chlamydia spp.

Answer 22

1. The LPS considered a putative virulence factor -> stimulates inflammatory response by the host that can result to atherosclerosis -> stimulation of production of immune complexes that can result in human stroke
2. Production of CPAF or chlamydial protease or proteasome-like activity factor which allows chlamydia to escape recognition by T-cells, allowing the bacterium to continue its life cycle repeatedly within the host
   * CPAF degrades the host transcription factors associated with the production of MHC or major histocompatibility complex molecules
   * CPAF is unique to and highly conserved among the chlamydiae
3. Type III secretion apparatus
   * Provides a “pore” in the vacuole membrane and allows transport of products into the cytosol of the host cells; CPAF maybe secreted in this manner
   * Chlamydiae have predilection for epithelial cells of the mucous membranes although other tissues are infected
   * Pneumonia develop from inhalation of infectious dust droplets in enzootic abortion in ewes, mode of infection is ingestion and organisms localize in the placenta
   * Latency is common feature of chlamydial infections which can be activated by various stress and concurrent infections
   * Chlamydial LPS stimulates interleukin -1 production, which mediates inflammation and scarring

Question 23

Chlamydia and Chlamydophila belong to Phylum ___ or the ____ forms.

Answer 23

IX; Wall-less forms

Question 24

Chlamydia muridarum induces what ds.?

Answer 24

Respiratory infections in mice

Question 25

Between elementary bodies and reticulate bodies, which one produce hemagglutinins?

Answer 25

Elementary bodies

Question 26

_____ bodies are shed in secretions and feces in small number from asymptomatic animals.

Answer 26

Elementary

Question 27

Describe the antigen complex of Chlamydia spp.

Answer 27

Antigen is a complement fixation antigen which is a **LPS in nature** with **ketodeoxyoctanoic acid** as the reactive moiety