Listeria - Exam 2 Flashcards Preview

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Flashcards in Listeria - Exam 2 Deck (19):
1

Listeria is catalase ________.

Positive

2

True/False. Listeria is a faculative anaerobe.

True

3

True/False. Listeria is an extracellular organism.

FALSE! It is falculative intracellular pathogen!

4

How can you distinguish L. monocytogenes from other species of Listeria?

CAMP test with S. aureus

5

How can you distinguish L. invanovii from other species of Listeria?

CAMP test with R. equi

6

Which species is most frequently affected by Listeria spp?

RUMINANTS!

7

What are the general affects of Listeria on animal species?

Septicemia (multifocal to diffuse necrosis in the liver and spleen)

Encephalitis

Abortion

8

What protein gives Listeria the ability to disseminate without having to move to the extracellular environment?

ActA

(virulence factor of listeria that hijacks actin inside host cell and allows bacteria to move)

9

What is the main virulence factor of Listeria and what is it's function?

Listeriolysin O (LLO)

Pore-forming cytolisin that releases the bacteria from the phagosome into the cytosol

10

What is the most natural reservior of Listeria?

Decomposing plant matter

11

How is Listeria transmitted?

Soil contamination (fecal-oral enrichment)

Ingestion of contaminated feed (ruminants)

Nasal mucosa and conjunctivae

12

Why are very young and very old animals infected more easily with Listeria?

When Listeria is orally ingested, most is killed by gastric acids. Young and old animals do not have a totally functioning stomach and cannot kill off a high number of bacteria initially.

13

Which types of cells do Listeria typically enter and survive in?

Epithelial cells

M-cells

Phagocytic cells

Hepatocytes

Endothelial cells

14

What is the most common manisfestation of Listeria in Ruminants?

Encephalitis (circling disease) 

A image thumb
15

Which type of exotic species is espeically susceptible to listerial septicemia?

Chinchillas

16

What is the most common manifestation of Listeria in humans?

Meningitis

17

Which seasons can animals be more susceptible to Listeria?

Winter and spring

18

What is the most classic source of infection of Listeria in ruminants?

Contaminated silages

19

Listeria produces ____-hemolysis and grows best under which conditions?

Narrow zone of beta-hemolysis

Grows best under reduced O2 and increased CO2