Deck 18: Nocardia Streptomyces Rhodococcus and Similar Organisms

Question 1

Non-acid-fast aerobic actinomycetes include:

A) Nocardia.
B) Rhodococcus.
C) Streptomyces.
D) Gordona.

Answer 1

C
Streptomyces, Actinomadura, Dermatophilus, Nocardiopsis, and the thermophilic Actinomycetes are gram-positive, branching filaments that do not have mycolic acids present in their cell envelopes and are therefore non-acid-fast.

Question 2

Which partially acid-fast, gram-positive, and branching filamentous bacteria appear dry and white to creamy to orange with rhizoid edges on routine agar and are urea-positive and resistant to lysozyme?

A) Tsukamurella
B) Gordonia
C) Actinomadura
D) Dermatophilus

Answer 2

A
Tsukamurella is a partially acid-fast, gram-positive, and branching filamentous bacterium that appears dry and white to creamy to orange with rhizoid edges on routine agar and is urea-positive and resistant to lysozyme.The other three organisms listed are lysozyme-sensitive.

Question 3

Partially acid-fast aerobic actinomycetes include:

A) Nocardia.
B) Mycobacteria.
C) Streptomyces.
D) Actinomadura.

Answer 3

A
The genera Nocardia, Rhodococcus, Gordonia, and Tsukamurella are all partially acid-fast aerobic actinomycetes.

Question 4

Nocardia spp.form branched filaments that extend into the air that are called _____ hyphae.

A) surface
B) substrate
C) aerial
D) topical

Question 5

The organism that has been most commonly associated with human disease, particularly in patients who are immunocompromised, such as those infected with human immunodeficiency virus (HIV), is:

A) Rhodococcus.
B) Gordonia.
C) Tsukamurella.
D) Streptomyces.

Question 6

A chronic, granulomatous infection of subcutaneous tissues, which is caused by aerobic actinomycetes resulting in tissue swelling and draining sinus tracts, is referred to as:

A) actinomycetoma.
B) infectious granulomas.
C) lymphocytoma.
D) Actinomadura.

Question 7

The group of bacteria that can be described as being normal inhabitants of soil and water and primarily responsible for the decomposition of plant material is:

A) Rhodococcus.
B) Nocardia.
C) Gordonia.
D) Tsukamurella.

Question 8

Nocardia spp.cause which of the following types of infections in individuals who are immunocompromised?

A) Mycetoma
B) Lymphocutaneous infections
C) Skin abscesses or cellulites
D) Invasive pulmonary infections

Question 9

Nocardia spp.form branched filaments that extend along the agar surface, which are called _____ hyphae.

A) surface
B) substrate
C) aerial
D) topical

Question 10

Which organisms should be used to run quality control for acid-fast stains?

A) Nocardia and Rhodococcus
B) Streptomyces and Actinomadura
C) Dermatophilus and Nocardiopsis
D) Nocardia and Streptomyces