Chlamydia and Mycoplasma

Question 1

Where are chalmydias found?

Answer 1

Intracellular

Question 2

What does Chlamydia use for energy?

Answer 2

Host ATP

Question 3

What are the two forms of chlamydia?

Answer 3

Infectious (elementary body) and replicative (reticular body)

Question 4

What is the elementary body like?

Answer 4

Rigid cell wall, low metabolism, extracellular

Question 5

Where in the body is Chlamydia found?

Answer 5

GI, resp and genital tract

Question 6

How can contamination by Chlamydia occur?

Answer 6

Infected placentas

Question 7

Why are Chlamydia carriers so common?

Answer 7

Many mechanisms to evade immune system - inhibits phagolysosome, down-regulates class II antigens, proteolytic cleavage of NFkB

Question 8

What are clinical signs of ocular Chlamydia?

Answer 8

Conjunctivitis, keratitis, corneal ulceration

Question 9

What resp signs can Chlamydia cause?

Answer 9

Exudative or purulent bronchiolitis with tracheitis, or pneumonia with areas of consolidation

Question 10

How big are mycoplasms?

Answer 10

The smallest free-living cells known

Question 11

What shape do Mycoplasmas take?

Answer 11

Filamentous or spherical

Question 12

What is the membrane of Mycoplasmas like?

Answer 12

Flexible, with no peptidoglycan

Question 13

What is gram stain of Mycoplasms?

Answer 13

-ve

Question 14

How do you grow Mycoplasmas?

Answer 14

Grows slowly, can be cultured on artificial media (tissue culture)

Question 15

What do Mycoplasma colonies look like?

Answer 15

Nipples

Question 16

Which toxins do Mycoplasmas produce?

Answer 16

Haemolysin, proteases, nucleases

Question 17

Which inflammatory cytokines do Mycoplasmas produce?

Answer 17

TNF, IL6, IL1

Question 18

How do Mycoplasmas attach to the host cell?

Answer 18

Via the anionic surface layer

Question 19

Which types of Mycoplasma has a specialised surface?

Answer 19

M pneumoniae and gallisepticum

Question 20

How do some Mycoplasmas increase attachment and predispose to bacteria?

Answer 20

Inhibit or destroy cilia

Question 21

How can mycoplasmas hide from the immune system?

Answer 21

Decrease phagocytosis by neutrophils or macrophages, decreased respiratory burst allows persistence in Macrophages, antigenic variability, molecular mimicry, induce polyclonal activation of B cells

Question 22

What do you see at PM in acute Mycoplasma infections?

Answer 22

Inflammation, neutrophil infiltration, fibrin, exudate

Question 23

What do you see in septicaemic Mycoplasma infection?

Answer 23

Coagulopathy, vascular thrombosis, shock (mediated by cytokines)

Question 24

What do you see in persistent Mycoplasma infection?

Answer 24

Often asymptomatic

Question 25

What do you see in localised Mycoplasma infections?

Answer 25

Tissue destruction, mastitis leading to fibrosis, proliferative synovitis, erosive arthritis, pleural thickening

Question 26

What are the main forms of Mycoplasma infection?

Answer 26

Respiratory, articular, mastitis

Question 27

How do you diagnose Mycoplasma?

Answer 27

With PCR but hard to culture

Question 28

What’s the problem with serology for Mycoplasma?

Answer 28

Does not show active infection

Question 29

What do you treat Mycoplasma with?

Answer 29

Tetracyclines, fluoroquinolones, macrolides

Question 30

Which class of drugs won’t work for Mycoplasma?

Answer 30

Beta lactams

Question 31

What can happen after treatment for Mycoplasma?

Answer 31

Post-treatment carrier state

Question 32

How do you control CBPP or CCPP?

Answer 32

Cull

Question 33

How do you control Mycoplasma in poultry?

Answer 33

Isolate or cull

Question 34

How do you control Mycoplasma in pigs?

Answer 34

Isolate or cull

Question 35

How is the infectious elementary body taken into the cell?

Answer 35

Phagocytosis

Question 36

What happens to the elementary body in the vacuole?

Answer 36

Restructures to a reticulate body

Question 37

How does the non-infectious reticulate body replicate?

Answer 37

Binary fission