Listeria and Erysipelothrix

Question 1

How many Listeria species are there?

Answer 1

10

Question 2

Listeria monocytogenes

Answer 2

most predominant pathogenic Listeria spp. in humans and animals

Question 3

Listeria ivanovii

Answer 3

emerging pathogen

Question 4

What is unique about L. monocytogenes?

Answer 4

it can grow at refrigerated temperatures (4C)

Question 5

cold-enrichment technique

Answer 5

can put samples in fridge to cause proliferation of Listeria and easier identification because other bacteria can’t grow

Question 6

Does listeria form spores?

Answer 6

no

Question 7

CAMP and CAMP-like Tests

Answer 7

Streaking a vertical line of
B-hemolytic S. aureus and
a horizontal line of B-hemolytic L. monocytogenes
results in a zone of
increased hemolysis
shaped like an arrowhead

Question 8

CAMP test was originally developed for what?

Answer 8

Step. agalactiae (mastitis)

Question 9

4 Types of Listeriosis in Animals

Answer 9

1. Intestinal
2. Visceral/septicemic
3. Abortive
4. Neural

Question 10

Circling disease (neural)

Answer 10

most common and fatal form of listeriosis associated with feeding silage

Question 11

When will you see circling disease in sheep?

Answer 11

winter/early spring when they lose/cut teeth

Question 12

Does neural listeriosis prefer the CNS or PNS?

Answer 12

CNS - causes meningoencephalitis in cattle and sheep

Question 13

Clinical Signs of Neural Listeriosis

Answer 13

depression, dec. appetite, dec. milk production, fever, circling, seizures, paralysis with difficulty swallowing, death d/t dehydration and starvation

Question 14

meningoencephalitis

Answer 14

microabscesses in the brain stem of cattle and sheep

Question 15

Abortive Listeriosis

Answer 15

predilection for the placenta; causes placentitis and fetal septicemia in sheep and cattle

Question 16

5 Stages of Listeria Infection

Answer 16

1. Internalization
2. Escape from phagolysosome
3. Nucleation of actin filaments
4. Cell-to-cell spread
5. Membrane vacuole

Question 17

Iron and Listeriosis

Answer 17

L. monocytogenes secretes siderophores to chelate iron and acts as a virulence factor

high iron can increase susceptibility to disease

Question 18

Main species affected by erysipelothrix?

Answer 18

swine (but also turkeys)

Question 19

Erysipelothrix rhusiopathiae

Answer 19

gram positive, non sporulating rods

Question 20

How to tell Listeria and Erysipelothrix apart?

Answer 20

Listeria = catalase positive and motile
Erysipelothrix = catalase negative and non-motile

Question 21

Smooth vs. Rough Erysipelothrix rhusiopathiae

Answer 21

smooth = what it sounds like, homogenous cell population
rough = mutant capsules with irregular borders, common with chronic infections

Question 22

Diamond Skin Disease

Answer 22

caused by Erysipelothrix rhusiopathiae and can be contracted via ingestion of feces/soil or skin scratches/punctures

aka porcine erysipelas

Question 23

Is Erysipelothrix rhusiopathiae stable?

Answer 23

yes, it is very hardy; can be maintained in asymptomatic carriers as well

Question 24

Three forms of Porcine Erysipelas

Answer 24

1. Acute
2. Subacute
3. Chronic

Question 25

Acute Porcine Erysipelas

Answer 25

pigs die suddenly with no symptoms

Question 26

Subacute Porcine Erysipelas

Answer 26

most frequent, pigs are febrile, won't eat, and are reluctant to move, and get skin discoloration and lesions which may slough off over time

Question 27

Chronic Porcine Erysipelas

Answer 27

swollen joints and lameness due to arthritis

Question 28

Mechanism of Disease of Porcine Erysipelas

Answer 28

septic emboli (acute/subacute) pus-containing bacteria circulates in the blood and will clot and occlude vessels, eventually leading to tissue death and necrosis

Question 29

Sequelae of Porcine Erysipelas in the Acute Forms

Answer 29

endocarditis

Question 30

Sequelae of Porcine Erysipelas in the Chronic Form

Answer 30

non-suppurative arthritis

Question 31

2 Proposed Virulence Factors of Erysipelas

Answer 31

1. Hyaluronidase 2. Sialidase

Question 32

Hyaluronidase

Answer 32

breaks down hyaluronic acid which cushions tissues and joints

Question 33

How do humans get infected with E. rhusiopathiae?

Answer 33

zoonotic, via direct skin penetration