Acid-fast bacilli isolate identification, setup

TEST DESCRIPTION

Culture of acid-fast bacilli (AFB) isolates for later identification. Growth and isolation of AFB on culture media is necessary for identification of Mycobacterium species by matrix-assisted laser desorption ionization time-of-flight (MALDI-TOF) and other methods. A confirmatory acid-fast stain will be performed on all isolates.

Methodology

Liquid and/or solid media culture

Reference range

No acid-fast bacilli present

TEST FREQUENCY & RESULT AVAILABILITY

Performed daily. Final identification may take ≥2 weeks depending on the growth rate of the isolate.

ACCEPTABLE SPECIMEN TYPES AND COLLECTION

• Pure AFB isolate submitted on solid media (e.g., Lowenstein Jensen, 7H10)
• A slant medium is preferred for safety purposes

SPECIMEN STORAGE & TRANSPORT

Store and transport at room temperature. All culture containers should be taped securely and double bagged when submitted. 

Note: If Mycobacterium tuberculosis is suspected, Category A (UN2814) packaging is required. Please contact the laboratory if Category A shipping supplies are needed.

REJECTION CRITERIA

• AFB isolates that are non-viable
• AFB isolates that arrive in culture containers that are damaged during transit or are not properly labeled

CODES

CPT: 87118
LOINC: 543-9
Test code: 3555

TEST FEE

Refer to the current fee schedule.