Corynebacterium, Rhodococcus, Nocardia

Question 1

What are the characteristics of Corynebacterium?

Answer 1

Gram +, pleomorphic, aerobic rods

Short mycolic acid chain in cell wall

Usually commensals

Opportunistic

Question 2

What kind of infections do Corynebacterium cause?

Answer 2

Mostly pyogenic infections

Chronic, granulomatous infections

Question 3

What does Corynebacterium diphtheriae cause?

Answer 3

Human childhood disease, diphtheria

Question 4

What does Corynebacterium pseudotuberculosis cause?

Answer 4

Caseous lymphadenitis in sheep and goats

Chronic pyogranulomatous infection of lymph nodes

Local lymphadenitis

Question 5

What kind of pathogen is Corynebacterium pseudotuberculosis?

Answer 5

Facultative intracellular pathogen

Question 6

What is a clinical sign of Corynebacterium pseudotuberculosis?

Answer 6

Abscess/chronic weight loss

Question 7

What do positive titers of Corynebacterium pseudotuberculosis indicate?

Answer 7

Indicate past resolved infections, recent exposure, recent vaccination, or active lesions

Question 8

Treatment options for Corynebacterium pseudotuberculosis include what?

Answer 8

Lancing and draining, surgical excision

Question 9

What does Corynebacterium pseudotuberculosis cause in horses?

Answer 9

Pigeon fever, ulcerative lymphangitis of lower extremities

Question 10

What does Corynebacterium pseudotuberculosis cause in cattle?

Answer 10

Bovine ulcerative lymphangitis

Question 11

What does Corynebacterium renale group cause?

Answer 11

Contagious bovine pyelonephritis - Disease of adult cows

Question 12

What is the reservoir for Corynebacterium renale?

Answer 12

Clinically normal carrier cows, lives in the urogenital tract

Question 13

What are the risk factors for Corynebacterium renale?

Answer 13

Trauma to bladder and urethra during parturition

Question 14

How is Corynebacterium renale transmitted?

Answer 14

Contaminated bedding, venereal transmission non-sterile OB instruments

Question 15

What does Corynobacterium kutscheri cause?

Answer 15

Murine pseudotuberculosis

Question 16

What does Corynobacterium kutscheri cause in the lungs?

Answer 16

Suppurative pneumonia

Question 17

What does Corynobacterium kutscheri cause in kidney, liver and heart?

Answer 17

Similar nodular lesions

Question 18

What does Corynobacterium kutscheri cause in joints?

Answer 18

Arthritic lesions of pedal extremities

Question 19

What does Corynobacterium kutscheri cause in lymph nodes?

Answer 19

Lymphoid hyperplasia of regional nodes

Question 20

What does Corynobacterium bovis cause?

Answer 20

Dermatitis, hyperkeratosis in mice

Question 21

What is Rhodococcus equi the main cause of?

Answer 21

Foal pneumonia

Most serious cause of pneumonia in 1-4 month old foals

Question 22

What kind of pathogen is Rhodococcus equi?

Answer 22

Facultative intracellular pathogen

Question 23

What is the possible reason for foal susceptibility to Rhodococcus equi?

Answer 23

Appears to be the result of a bacterial-directed inappropriate Th2, rather than Th1 based immune response

Question 24

Where does Rhodococcus equi target itself?

Answer 24

The macrophages

Question 25

What is the standard empirical treatment for Rhodococcus equi?

Answer 25

Combo of macrolide and rifampin

Question 26

What kind of bacteria are Nocardia?

Answer 26

Facultative intracellular bacterium

Question 27

What is a key point about pathogenic Nocardia spp?

Answer 27

They are saprophytes and live in soil, water and on plants

Infections often follow wounds or are nosocomial

Question 28

What can be observed in the exudate to diagnose myocardial or actinomycotic infections?

Answer 28

Sulphur granules

Question 29

What is the most common isolated species of Nocardia in dogs and cats?

Answer 29

N. asteroides

Question 30

What animal is N. mastitis seen in?

Answer 30

Cattle

Question 31

What is the best choice for Nocardia treatment?

Answer 31

Aminoglycoside and a carbapenem