Actinobacillus

Question 1

What is the gram reaction of Actinobacillus?

Answer 1

Gram negative

Question 2

What is the shape of Actinobacillus?

Answer 2

Coccobacilli

Question 3

What are the classifications of Actinobacillus?

Answer 3

Surface slime or Encapsulated

Question 4

What are the surface slime Actinobacillus?

Answer 4

A. suis
A. equuli
A. lignieresii

Question 5

What are the encapsulated Actinobacillus?

Answer 5

A. pleuropneumoniae

Question 6

Which bacteria is Actinobacillus most similar to?

Answer 6

Pasteurella

Question 7

True or False. Most actinobacilloses are exogenous infections.

Answer 7

False.

It is only exogenous in neonates because foals acquire A. equuli via umbilicus

It is mostly endogenous

Question 8

What is the commensal habitat of Actinobacillus?

Answer 8

Mucous membranes

Question 9

Actinobacillus appears as greyish, white colonies on what agar?

Answer 9

Chocolate agar

Question 10

What does Actinobacillus produce on blood agar?

Answer 10

A thin zone of hemolysis

Question 11

What happens to Actinobacillus on MacConkey?

Answer 11

It grows but dies within a week

Question 12

What is need to facilitate the growth of Actinobacillus?

Answer 12

Pre-formed factors in blood

X factors (hemin)
V factor (NAD, NADP)

Question 13

How is chocolate agar prepared to facilitate the growth of Actinobacillus?

Answer 13

Heated to 80C to release X and V factors

Question 14

What are the cellular products of Actinobacillus?

Answer 14

RTX-type hemolysins
RTX toxins
RTX gene
Pili
LPS
Outer Membrane Proteins
Actinobacillus-ferric uptake (AfuA)
Antiphagocytic capsule
R plasmids

Question 15

What are the RTX-type hemolysins of Actinobacillus?

Answer 15

Apx I
Apx II
Apx III (pleurotoxin)

Question 16

What do RTX toxins do?

Answer 16

It kills macrophages and neutrophils

Question 17

Which Actinobacillus species uses pili and what for?

Answer 17

A. pleuropneumoniae

To adhere to alveolar epithelia and cilia of terminal bronchioles

Question 18

What do the OMPs of Actinobacillus do?

Answer 18

Binds to transferrin-iron complexes needed for growth

Question 19

What does the AfuA of Actinobacillus do?

Answer 19

For iron transport

Question 20

R plasmids contain AMR genes for which antimicrobials?

Answer 20

Sulfonamides
Tetracycline
Penicillin

Question 21

At high concentrations, RTX toxins can cause damage to what?

Answer 21

Macrophages
Neutrophils

Question 22

At low concentrations, phagocytic cell is increased which causes what?

Answer 22

Neighboring cell damage
Inflammation

Question 23

How does Actinobacillus infect?

Answer 23

LPS binds to LPS binding protein to cause the release of interleukin-1 and tumor necrosis factor

Question 24

How does Actinobacillus infection spread in the body?

Answer 24

Via the lymphatic system

Question 25

What kind of lesions does Actinobacillus cause?

Answer 25

Suppurative to granulomatous lesions

Question 26

What does Actinobacillus cause in Ruminants?

Answer 26

Wooden tongue

Question 27

What Actinobacillus species causes Wooden tongue?

Answer 27

A. lignieresii

Question 28

What are the symptoms of wooden tongue?

Answer 28

Chronic granuloma

Question 29

What does Actinobacillus cause in horses?

Answer 29

Navel ill Rarely Wooden tongue

Question 30

What Actinobacillus causes Navel ill?

Answer 30

A. equuli

Question 31

What are the symptoms of navel ill?

Answer 31

Enteritis (adults and calves) Suppurative multifocal nephritis Tenovaginitis Arthritis

Question 32

What Actinobacillus affects swine?

Answer 32

A. suis A. pleuropneumoniae

Question 33

What are the symptoms of an A. suis infection in swine?

Answer 33

Respiratory inflammation Septicemic inflammation Localized infections

Question 34

What does A. pleuropneumonia cause in swine?

Answer 34

Porcine pleuropneumonia

Question 35

What are the symptoms of porcine pleuropneumonia?

Answer 35

Necrotic lesions Granulomatous pneumonia

Question 36

How is Actinobacillus diagnosed?

Answer 36

Growing on blood agar and gram staining

Question 37

How do you treat septicemic Actinobacillus infections?

Answer 37

Early treatment with Penicillin G Tetracycline Ceftiofur

Question 38

What other treatments are used for Actinobacillus infections?

Answer 38

Gentamicin Kanamycin Cephalosporin TMPS

Question 39

How do you prevent Actinobacillus infections?

Answer 39

Avoiding harsh, dry feeds Good foaling hygiene Eliminating infected breeding animals Mass medication