Acid-Fast Bacillus (AFB) Culture and AFB Stain with Reflex to Mycobacterium tuberculosis Complex Detection and Rifampin Resistance by PCR

Respiratory specimens under 5 mL will receive a volume suboptimal disclaimer in the report.

Positive cultures are reported as soon as detected. AFB stain, AFB identification of positives, and susceptibility tests are billed separately from culture. Identification of positive culture is billed by matrix-assisted laser desorption ionization (MALDI) and/or sequencing tests performed. Mycobacterium tuberculosis Complex Detection and Rifampin Resistance by PCR (ARUP test code 2010775) is available for respiratory, CSF, body fluid, and tissue specimens.

The laboratory should be notified when the presence of Mycobacterium genavense or Mycobacterium haemophilum is suspected, as these organisms will not grow on media routinely used for Mycobacterium isolation.

The laboratory should be notified when M. xenopi is suspected, as this organism requires a different temperature from routine culture setup.

The laboratory should be notified if the specimen is from a cystic fibrosis patient, as these specimens need additional decontamination from routine culture setup.

Susceptibility will be performed on organisms isolated from a sterile source and isolates of Mycobacterium tuberculosis complex, M. chelonae, M. abscesses, M. fortuitum complex, M. immunogenum, M. mucogenicum. Susceptibility testing will be performed by request only on M. kansasii and M. marinum. Susceptibility testing of M. gordonae is inappropriate.

For AFB susceptibility information, refer to Antimicrobial Susceptibility - AFB Mycobacteria (ARUP test code 0060217).

For AFB culture on blood refer to Culture, Acid-Fast Bacillus, Blood (ARUP test code 0060060).

After a positive result, repeat orders for Mycobacterium tuberculosis Complex Detection and Rifampin Resistance by PCR will continue to yield a positive result and repeat testing is not clinically indicated.