E2 Order Actinomycetales

Question 1

What are the 3 important families in this order Actinomycetales?

Answer 1

1. Actinomycetaceae
2. Mycobacteriaceae
3. Nocardiaceae

Question 2

What is the gram stain of the order Actinomycetales?

Answer 2

Gram-positive

Question 3

What is unique about the appearance of the order Actinomycetales?

Answer 3

Long branching filamentous rods
Sometimes beaded
(mycelia)

Question 4

What are some culture characteristics of the family actinomycetaceae?

Answer 4

1. Microaerophilic
2. NOT-acid fast
3. Formation of sulfur granules (rosetts)

Question 5

What are sulfur granules composed of?

Answer 5

1. Bacterial filaments

2. Calcium phosphate from the host

Question 6

What are some characteristics of actinomycetaceae family infections?

Answer 6

1. Chronic
2. Soft & hard tissues
3. Often with foreign bodies

Question 7

What species has actinomyces bacteria as normal flora? Where?

Answer 7

Dog

Oropharynx & digestive tract

Question 8

What are the clinical signs when a dog has an overgrowth of actinomyces bacteria?

Answer 8

Soft tissue swellings with sulfur granules

head & neck

Question 9

What are some clinical presentations of actinomyces infections in cats (3)? Which one is most common?

Answer 9

1. Bite wound abscess
2. Pyothorax = most common
3. Peritonitis

Question 10

How can an actinomyces infection lead to pyothorax?

Answer 10

Deep chest wound

Question 11

What type of antibiotics work well against actinomyces?

Answer 11

Penicillins

Question 12

Is actinomyces normal flora in cattle? If so where?

Answer 12

Yes
Oral cavity
But can be opportunistic invaders of deep tissues

Question 13

What is the name for the disease caused by actinomyces in cattle?

Answer 13

Lumpy Jaw

Question 14

What is actinomyces infection associated with in cattle?

Answer 14

Foreign bodies

Question 15

What two diseases does actinomyces cause in horses?

Answer 15

1. Fistulous withers

2. Poll evil

Question 16

What two diseases can actinomyces cause in swine although rare?

Answer 16

1. Suppurative mastitis

2. Cystitis in older sows

Question 17

What pathological process occurs in cattle with actinomyces infections?

Answer 17

Proliferative osteomyelitis

Question 18

Is there a vaccine for actinomyces bovis?

Answer 18

No

Question 19

What is another genus of the actinomycetaceae family?

Answer 19

Arcanobacterium

Question 20

What is the only species of arcanobacterium of veterinary importance?

Answer 20

Arcanobacterium pyogenes

Question 21

What role does arcanobacterium pyogenes play in animal health?

Answer 21

Commensal of the skin, upper respiratory tract and genitals

Question 22

What diseases can arcanobacterium pyogenes cause if it enters deep tissues (4)?

Answer 22

1. Mastitis
2. Arthritis (green caseous pus)
3. Placentitis
4. Polyarthritis

Question 23

What is another genus of gram-positive filamentous bacteria?

Answer 23

Nocardia

Question 24

Where is Nocardia typically found?

Answer 24

Soil

Question 25

What is special about Nocardia’s metabolism?

Answer 25

Obligate aerobe

Question 26

What is the most important veterinary species of Nocardia?

Answer 26

Nocardia asteroides

Question 27

How does Nocardia asteroides cause infections?

Answer 27

1. Dirt in wounds
2. Inhalation
3. Ingestion

Question 28

What animals can be infected with Nocardia asteroides?

Answer 28

Mammals

rare in birds

Question 29

What cells are infected by Nocardia asteroides?

Answer 29

Phagocytes

Question 30

What disease does Nocardia asteroides cause in cattle?

Answer 30

Mastitis

Question 31

What diseases does Nocardia asteroides cause in dogs & cats (2)?

Answer 31

1. Localized skin infections

2. Generalized = pyothroax (high mortality)

Question 32

What is are common clinical findings with Nocardia asteroides infection (2)?

Answer 32

Small white nodules on organs

Question 33

What drug is NOT a good choice for Nocardia asteroides infection?

Answer 33

Penicillin

strongly resistant

Question 34

Is Nocardia asteroides zoonotic?

Answer 34

No

Question 35

What is another gram positive branching filamentous bacteria (D)?

Answer 35

Dermatophilus

Question 36

What is special about Dermatophilus?

Answer 36

It forms spores!

zoospores = flagella

Question 37

Where is Dermatophilus commonly found?

Answer 37

Africa & India in the soil

Question 38

What form of Dermatophilus is infectious?

Answer 38

Zoospores

Question 39

What disease does Dermatophilus congolensis cause?

Answer 39

(Dermatophilosis)
Horses
=Rain scald
=Grease heel
Sheep
= Lumpy wool
=Strawberry footrot

Question 40

Where is the reservoir for Dermatophilus congolensis?

Answer 40

Infected animals

not the soil

Question 41

What causes increased infections of Dermatophilus congolensis?

Answer 41

Wet weather

Question 42

Is Dermatophilus congolensis zoonotic?

Answer 42

Yes!
= Rare but can happen
(Remember to wear PPE)