Test Catalog

Test ID: SSF1    
Nocardia Stain, Varies

Useful For Suggests clinical disorders or settings where the test may be helpful

Detection of Nocardia species and other partially-acid fast aerobic actinomycetes in clinical specimens

Testing Algorithm Delineates situations when tests are added to the initial order. This includes reflex and additional tests.

When this test is ordered, the reflex test may be performed and charged.

Clinical Information Discusses physiology, pathophysiology, and general clinical aspects, as they relate to a laboratory test

Nocardia species and other aerobic actinomycetes can cause significant disease in immunocompromised patients. Clinical presentations can include, but are not limited to, pneumonia, skin abscess, bacteremia, brain abscess, eye infection, and joint infection.


The modified acid-fast stain can detect Nocardia species and other partially-acid fast aerobic actinomycetes directly from clinical specimens.

Reference Values Describes reference intervals and additional information for interpretation of test results. May include intervals based on age and sex when appropriate. Intervals are Mayo-derived, unless otherwise designated. If an interpretive report is provided, the reference value field will state this.

Reported as positive or negative

Interpretation Provides information to assist in interpretation of the test results

Patients whose specimens are reported as partially acid-fast positive should be considered potentially infected with Nocardia species or other aerobic actinomycetes, pending definitive diagnosis by molecular methods or culture.

Cautions Discusses conditions that may cause diagnostic confusion, including improper specimen collection and handling, inappropriate test selection, and interfering substances

Artifacts may exhibit nonspecific staining and be confused with organisms. Not all aerobic actinomycetes stain as partially acid-fast. A negative stain does not rule out the possibility of infection and culture should be performed. Nocardia species and other aerobic actinomycetes grow well on mycobacterial culture medium so CTB / Mycobacteria and Nocardia Culture, Varies should be ordered. Sometimes, Nocardia species can also be recovered in fungal cultures (FGEN / Fungal Culture, Routine).

Clinical Reference Recommendations for in-depth reading of a clinical nature

Brown-Elliott BA, Brown JM, Conville PS, Wallace RJ: Clinical and laboratory features of the Nocardia spp. based on current molecular taxonomy. Clin Microbiol Rev 2006 Apr;19(2):259-282