Lesson 3 (VMCB)

Question 1

media for nocardia species

Answer 1

Sabouraud dextrose agar

Question 2

A 5-year-old dairy cow presents with acute mastitis, characterized by a foul-smelling purulent secretion from the udder. Culture results indicate a Gram-positive, facultative anaerobic bacterium with pitting on Loeffler’s serum slope. What is the most likely causative agent?

Answer 2

Trueperella pyogenes

Question 3

A beef cow presents with a firm, non-painful swelling on the mandible that exudes pus containing sulfur granules. Radiographs reveal osteomyelitis. Which pathogen is the most likely cause?
A) Nocardia asteroides
B) Actinobaculum suis
C) Actinomyces bovis
D) Trueperella pyogenes

Answer 3

Actinomyces bovis

Question 4

A dog presents with respiratory distress, fever, and multiple draining subcutaneous abscesses. Cytology reveals Gram-positive, partially acid-fast filamentous bacteria. What is the most likely causative agent?

Answer 4

Nocardia asteroides

Question 5

A group of cattle develops exudative dermatitis with scab formation after a prolonged rainy season. Giemsa-stained smears reveal Gram-positive filamentous bacteria with coccoid zoospores. What is the most likely diagnosis?

Answer 5

Dermatophilosis

Question 6

A pregnant sow presents with hematuria, dysuria, and arching of the back. The causative organism is an anaerobic, Gram-positive rod isolated from the urinary tract. What is the most likely pathogen?

Answer 6

Actinobaculum suis

Question 7

Which Actinobacteria species is commonly associated with suppurative lesions and abscess formation in livestock?

Answer 7

Trueperella pyogenes

Question 8

A horse with nocardiform placentitis caused by Crossiella equi is most likely to experience:

Answer 8

Abortion in late gestation

Question 9

The primary virulence factor of Trueperella pyogenes that contributes to its pathogenicity is:

Answer 9

Pyolisin

Question 10

The presence of club-shaped structures in histopathological sections is most characteristic of:

Answer 10

Actinomyces bovis

Question 11

A distinguishing feature of Nocardia species is:

Answer 11

Partial acid-fast staining

Question 12

Which of the following organisms does NOT grow on Sabouraud dextrose agar?

Answer 12

Dermatophilus congolensis

Question 13

associated with equine nocardiform placentitis, leading to loss of the foal in approximately 50% of cases

Answer 13

Crossiella equi

Question 14

long, slender, branching filaments with a tendency to fragment into rods and cocci in smears

Answer 14

nocardia sp.

Question 15

species under genus nocardia

Answer 15

N. asteroides, N. farcinica

Question 16

found in scabs and in foci on skin of carrier animals

Answer 16

Dermatophilus congolensis

Question 17

atmospheric growth requirements of actinomyces

Answer 17

Anaerobic, or facultative anaerobic, capnophilic

Question 18

atmospheric growth requirements of arcanobacterium pyogenes

Answer 18

Facultative anaerobic, and capnophilic

Question 19

habitat of actinobaculum suis

Answer 19

Prepuce and preputial diverticulum of boars

Question 20

their usual habitat are soils

Answer 20

nocardia sp.

Question 21

produces pyolisin which is cytolytic for several cell types including neutrophils and macrophages, and is dermonecrotic and lethal for laboratory animals

Answer 21

Trueperella pyogenes

Question 22

usual mode of infection by nocardia sp.

Answer 22

inhalation (or thru skin wounds or via teat canal)

Question 23

produce germ tubes and these develop into filaments which invade the epidermis

Answer 23

Dermatophilus congolensis zoopores

Question 24

reveals aggregates of filamentous organisms surrounded by eosinophilic club- shaped structures

Answer 24

lesions caused by Actinomyces bovis

Question 25

selective growth enhancing media for Nocardia sp.

Answer 25

charcoal yeast extract medium

Question 26

in which agar nocardia sp. yields dry, wrinkled, orange- coloured colonies after incubation for up to 5 days

Answer 26

Sabouraud dextrose agar

Question 27

in which agar nocardia sp. Become white, powdery and firmly adherent to agar

Answer 27

blood agar

Question 28

Specimens suitable for laboratory examination for dermatophilosis

Answer 28

scab material and samples of skin fixed in formalin

Question 29

opportunistic pathogen and is a common cause of suppurative lesions in many domestic species worldwide

Answer 29

Trueperella pyogenes

Question 30

chronic rarefying osteomyelitis following trauma to the mucosa from rough feed or through dental alveoli during tooth eruption

Answer 30

lumpy jaw

Question 31

affects the urinary tract of pregnant sows, is transmitted at coitus and is potentially fatal

Answer 31

Actinobaculum suis

Question 32

Etiology of Canine actinomycosis resulting to subcutaneous pyogranulomatous lesions and extensive fibrovascular proliferation on the peritoneal or pleural surfaces

Answer 32

Actinomyces viscosus

Question 33

causative agent of lumpy jaw

Answer 33

Actinomyces bovis

Question 34

This specific disease, which affects the urinary tract of pregnant sows, is transmitted at coitus and is potentially fatal.

Answer 34

Porcine cystitis and pyelonephritis

Question 35

These bacteria are usually confined to the epidermis

Answer 35

Dermatophilus congolensis

Question 36

Disease condition of Nocardia species associated with pigs

Answer 36

Abortion