Rhodococcus (Exam 5)

Question 1

Rhodococcus equi is a gram (negative/positive) _______.

Answer 1

gram-positive rod

Question 2

Rhodococcus equi is partially ________.

Answer 2

acid-fast

Question 3

Rhodococcus equi are (hemolytic/non-hemolytic) and produce ________ reaction, seen as “pink flowing” colonies on blood agar.

Answer 3

non-hemolytic
CAMP positive

Question 4

Oxygen requirement for Rhodococcus equi.

Answer 4

obligate aerobes

Question 5

(T/F) Rhodococcus equi is a facultative intracellular parasite.

Answer 5

True

Question 6

After phagocytosis, Rhodococcus equi survives in:

Answer 6

alveolar macrophages

Question 7

What structure is in Rhodococcus equi cell wall?

Answer 7

mycolic acids

Question 8

Rhodococcus equi has a large conjugative virulence plasmid with __________ _________.

Answer 8

pathogenicity island

Question 9

The pathogenicity island in Rhodococcus equi encodes genes for 7 virulence associated proteins. _____, ______, and _____ function for survival in macrophages.

Answer 9

vapA
vapC
vapH

Question 10

(T/F) Strains that lack vapA, vapC, and vapH survive in macrophages.

Answer 10

False (DO NOT)

Question 11

What habitat is Rhodococcus found?

Answer 11

soil (multiples in horse manure)

Question 12

Major route of Rhodococcus transmission.

Answer 12

aerosol via dust (inhalation)

Question 13

What disease does Rhodococcus equi cause?

Answer 13

“Rattles” (pneumonia)

Question 14

(T/F) Incidence of Rhodococcus equi is sporadic.

Answer 14

True

Question 15

Which species is affected by Rhodococcus? What age is most often infected?

Answer 15

horses (2-3 month foals)

Question 16

What is the main lesion associated with Rhodococcus equi?

Answer 16

purulent bronchopneumonia

Question 17

(T/F) Rhodococcus presents with initially severe signs of lung abscess.

Answer 17

False (initially subtle, not recognized until severe lung abscesses)

Question 18

List 3 signs of Rattles.

Answer 18

1. constant cough
2. mucopurulent nasal discharge
3. fever

Question 19

What is heard on auscultation for Rhodococcus?

Answer 19

pleural involvement (rattles, crackles)

Question 20

Rhodococcus has a (high/low) mortality when treated.

Answer 20

high

Question 21

List 4 extrapulmonary disorders Rhodococcus can be associated with.

Answer 21

1. GI lesions
2. arthritis
3. uveitis
4. peripheral abscess

Question 22

Rhodococcus causes abscesses throughout the lung but often in _________ lymph nodes.

Answer 22

bronchial

Question 23

What is the only definitive diagnostic method for Rhodococcus?

Answer 23

culture or PCR of tracheobronchial aspirates

Question 24

________ ________ is important for successful therapy for Rhodococcus infection.

Answer 24

early diagnosis