BRANCHING OR PARTIALLY ACID-FAST, GRAM-POSITIVE BACILLI (NOCARDIA, STREPTOMYCES, RHODOCCOCUS, AND SIMILAR ORGANISMS)

Question 1

IDENTIFY

Gram-positive (often with a beaded appearance)
Variably acid fast
Catalase positive
Strictly aerobic
Saprophytes
Pulmonary cutaneous infection in humans

Answer 1

Nocardia spp.

Question 2

IDENTIFY

MC isolated in humans
Immunocompromised patients as a chronic infection particularly
pulmonary
Pleomorphic and partially acid fast
Slow growing (up to 6 weeks): dry and heaped colonial morphology
similar to fungus
Soil or musty basement odor
Exudates: sulfur granules

Answer 2

N. asteroides

Question 3

IDENTIFY

Etiologic agent of mycetoma
Not acid fast
Similar microscopic and macroscopic morphology to Nocardia

Answer 3

Actinomadura

Question 4

IDENTIFY

Primarily saprophytes: soil organisms
Opportunistic infections similar to other actinomycetes

Answer 4

Streptomyces