Caseous Lymphadenitis - PL

Question 1

For caseous lymphadenitis:

1. Name the cause
2. Describe the parasite
3. State how it appears on a disk

Answer 1

1. Corynebacterium pseudotuberculosis
2. Facultative anaerobe - gram positive coccoid rod
3. Zone of haemolysis on blood sugar

Question 2

What are the two virulence factors for C.pseudotuberculosis?

Answer 2

• Cell wall withstands lysosomes
• Phospholipase D endotoxin

Question 3

What is the incubation time of C.pseudotuberculosis?

Answer 3

• Approximately 8-9 days for small abscesses
• 2-6 months for larger abscesses

Question 4

How should testing be done for C.pseudotuberculosis?

Answer 4

• Paired titres should be used – 2 weeks apart and we are looking for a 4-fold rise in titre

Question 5

What is the major differential for C.lymphadenitis?

Answer 5

Wattle cyst