Chlamydia

Question 1

To which phylum do Chlamydia and Chlamydophila belong?

Answer 1

Phylum IX (Wall-less Forms)

Question 2

What family do these genera belong to?

Answer 2

Chlamydiaceae

Question 3

Are chlamydiae motile or non-motile?

Answer 3

Non-motile

Question 4

What type of Gram stain result do chlamydiae exhibit?

Answer 4

Gram-negative

Question 5

What term describes the shape variability of chlamydiae?

Answer 5

Pleomorphic

Question 6

What kind of parasitic lifestyle do chlamydiae have?

Answer 6

Obligate intracellular parasites

Question 7

What makes their developmental cycle unique?

Answer 7

They replicate within host cells using a biphasic cycle

Question 8

Which species causes avian chlamydiosis and psittacosis?

Answer 8

Chlamydophila psittaci

Question 9

What diseases does C. pecorum cause in cattle?

Answer 9

Sporadic bovine encephalitis, infectious polyarthritis, pneumonia, diarrhea

Question 10

Which species causes enzootic abortion in sheep?

Answer 10

Chlamydophila abortus

Question 11

What does C. suis infect in pigs?

Answer 11

Intestinal tract

Question 12

What condition does C. caviae cause in guinea pigs?

Answer 12

Inclusion conjunctivitis

Question 13

What is the primary disease caused by C. felis?

Answer 13

Feline pneumonitis (conjunctivitis)

Question 14

How many serovars does C. trachomatis have?

Answer 14

More than 15 serovars

Question 15

What mouse pathogen causes respiratory infections?

Answer 15

Chlamydia muridarum

Question 16

What nucleic acids do chlamydiae possess?

Answer 16

Both RNA and DNA

Question 17

What three compounds can they metabolize?

Answer 17

Glucose, pyruvate, glutamate

Question 18

What is their antibiotic susceptibility?

Answer 18

Broad-spectrum antibiotics

Question 19

What cellular change occurs after phagocytosis?

Answer 19

Forms intracytoplasmic, membrane-limited inclusions

Question 20

How do reticulate bodies reproduce?

Answer 20

Binary fission

Question 21

What is the genus-specific antigen of Chlamydia?

Answer 21

LPS with ketodeoxyoctanoic acid

Question 22

What produces hemagglutinins of Chlamydia?

Answer 22

Elementary bodies only

Question 23

Where are chlamydiae normally found?

Answer 23

Respiratory and GI mucous membranes

Question 24

How do elementary bodies persist in the environment?

Answer 24

In soil and feces for long periods

Question 25

What are the three main virulence factors of Chlamydia

Answer 25

LPS, CPAF protease, Type III secretion system

Question 26

How does CPAF work?

Answer 26

Degrades host MHC transcription factors

Question 27

What is a key feature of chlamydial infections?

Answer 27

Latency that can be reactivated

Question 28

What two staining methods are used for Chlamydia

Answer 28

Giemsa and Gimenez

Question 29

What brain changes are characteristic?

Answer 29

Purulent meningoencephalitis

Question 30

What is the human mortality rate if untreated?

Answer 30

Up to 20%

Question 31

C. psittaci: Q: What are the avian clinical signs?

Answer 31

Ocular/nasal discharge, sinusitis, conjunctivitis

Question 32

C. abortus: Q: What is the incubation period in sheep?

Answer 32

Latent until conception

Question 33

C. pecorum: Q: What is the mortality rate in SBE (Sporadic Bovine Encephalomyelitis)?

Answer 33

Up to 50%

Question 34

C. felis: Q: What age cats are most affected?

Answer 34

5-12 week old kittens

Question 35

What is the infectious forms of Chlamydia?

Answer 35

Elementary bodies

Question 36

What is the Intracytoplasmic form of Chlamydia

Answer 36

Reticulate bodies

Question 37

All chlamydiae share a genus-specific antigen (T/F)

Answer 37

True

Question 38

Immunity response for Chlamydia

Answer 38

Both cell-mediated and humoral

Question 39

What is considered as a putative virulence factor of Chlamydia?

Answer 39

LPS

Question 40

which allows chlamydia to escape recognition by T-cells, allowing the bacterium to continue its life cycle repeatedly within the host?

Answer 40

CPAF or chlamydial protease or proteasome-like activity factor

Question 41

CPAF is unique to and highly conserved among the chlamydiae (T/F)

Answer 41

True