Listeria (Exam 5)

Question 1

What is the oxygen requirement for Listeria?

Answer 1

facultative anaerobe

Question 2

Listeria is a gram (negative/positive) (spore/non-spore)-forming ________.

Answer 2

gram-positive non-spore forming rod

Question 3

Listeria is (motile/non-motile).

Answer 3

motile (4-6 peritrichous flagella)

Question 4

Listeria ________ causes a serious, food-borne illness in humans.

Answer 4

L. monocytogenes

Question 5

Where can Listeria monocytogenes can found?

Answer 5

soil, decaying veggies, feces

Question 6

What temperatures can Listeria grow in?

Answer 6

psychotropic (refrigeration temps)

Question 7

(T/F) Listeria can survive intracellularly.

Answer 7

True

Question 8

Listeria monocytogenes are highly infectious with (high/low) pathogenicity.

Answer 8

low

Question 9

Listeria monocytogenes can be cultured on blood agar and under ________ for neural listeriosis (brain tissue)

Answer 9

cold-enrichment

Question 10

Match the virulence factor of Listeria to its function:

1. pore-forming toxin; phagosome escape
2. adhesion & internalization (“zipper mechanism”)
3. escape from vacuole & cell-to-cell spread
4. actin polymerization

Answer 10

1. Listeriolysin O
2. Internalins
3. Phospholipase C
4. ActA protein

Question 11

What kind of Listeriosis infection is most common?

Answer 11

subclinical

Question 12

How is Listeria transmitted?

Answer 12

ingestion

Question 13

Subclinical Listeriosis occurs by ingestion which penetrates the intestinal epithelium and travels to the _______.

Answer 13

liver

Question 14

Subclinical Listeriosis is mediated by what type of immunity?

Answer 14

cell-mediated

Question 15

Listeriosis is associated with 3 syndromes:

Answer 15

1. neural/encephalitic
2. abortion
3. septicemia + visceral abscess

Question 16

Neural or Encephalitic Listeriosis is commonly called “__________” or “________”.

Answer 16

Silage Sickness
Circling Disease

Question 17

The main lesion with Neural or Encephalitic Listeriosis is:

Answer 17

meningoencephalitis

Question 18

Meningoencephalitis caused by Listeria leads to what 3 clinical signs?

Answer 18

1. unidirectional circling
2. unilateral facial paralysis
3. corneal opacity

Question 19

Which species of animal most commonly develops the Neural form of Listeriosis?

Answer 19

ruminants (cattle, sheep, goats)

Question 20

Transmission of Neural Listeriosis is associated with poor-quality or spoiled _________.

Answer 20

silage

Question 21

Abortion due to Listeriosis occurs when 2 ________ target and cross the placental barrier in pregnant animals.

Answer 21

invasion proteins

Question 22

Abortion caused by Listeriosis occurs sporadically in _________, is a flock condition in _________, and very rare in _______.

Answer 22

cattle
sheep
dogs

Question 23

How is Abortive Listeriosis controlled?

Answer 23

change spoiled silage or dilute with better silage

Question 24

Which form of Listeriosis is the LEAST common?

Answer 24

Visceral Listeriosis (septicemia w/ visceral abscesses)

Question 25

Visceral Listeriosis ONLY occurs in:

Answer 25

neonates

Question 26

Septicemia and ________ are the most common signs of Visceral Listeriosis.

Answer 26

gastroenteritis

Question 27

What is the characteristic lesion of Visceral Listeriosis?

Answer 27

focal hepatic necrosis

Question 28

(T/F) Humans are susceptible to Listeriosis.

Answer 28

True (especially infants, elderly, immunosuppressed, pregnant)

Question 29

______ & ______ products are animal sources of Human Listeriosis.

Answer 29

meat & dairy

Question 30

Field-grown products such as lettuce, vegetables, and cantaloupes are associated with Human Listeriosis due to _______ contamination.

Answer 30

manure

Question 31

(T/F) Human Listeriosis can occur by direct contact with an infected animal.

Answer 31

False