Identify susceptibility of clinically significant isolates of M. tuberculosis complex (MTBC), M. kansasii, M. avium-intracellulare complex, M. fortuitum complex, M. abscessus complex, M. chelonae, M. immunogenum, and any isolate from a significant source.
Macrobroth Dilution/Microbroth Dilution
Actively growing isolate in pure culture.
Transport sealed container with pure culture on solid or liquid media. Place each specimen in an individually sealed bag.
Room temperature. If culture is suspected of being a microorganism identified on the IATA list as an infectious substance affecting humans, submit specimen according to Infectious Substance, Category A, shipping guidelines.
Mixed cultures or non-viable organisms. Organisms submitted on an agar plate.
Ambient: 2 weeks; Refrigerated: 2 weeks; Frozen: 2 weeks
||Reference Interval/Drugs Tested
|0060347||Antimicrobial Susceptibility - AFB/Mycobacterium tuberculosis Primary Panel||MGIT960||The interpretation provided is based on results for the following drugs at the stated concentrations:
Drugs tested: Ethambutol: 5.0 µg/mL; Isoniazid: 0.1 µg/mL (0.4 µg/mL if resistant to 0.1 µg/mL); Pyrazinamide: 100 µg/mL; Rifampin: 1.0 µg/mL.
This procedure screens isolates of M. tuberculosis complex for drug resistance. The procedure does not use serial dilutions to provide quantitative MIC values. Single critical concentrations for each antimycobacterial agent used have been defined by the United States Public Health Service.
|Antimicrobial Susceptibility - AFB/Mycobacterium tuberculosis Secondary Panel||Agar proportion
and Broth dilution
|Effective February 21, 2012
Note: If M. tuberculosis isolate is resistant to rifampin or any two primary drugs, a secondary panel will be performed as a send-out test. The interpretation provided is based on testing for the following drugs at the stated concentrations:
Drugs tested: Amikacin: 6 µg/mL; capreomycin: 10 µg/mL; cycloserine: 60 µg/mL; ethionamide: 10 µg/mL; kanamycin: 6 µg/mL; PAS: 8 µg/mL; streptomycin at a low level (2.0 µg/mL) and a high level (4.0 µg/mL). Levofloxacin and moxifloxacin are tested at 2, 4 and 8 µg/mL
|87190 x6, 87188 x3|
|Antimicrobial Susceptibility - AFB/Mycobacteria||Broth Microdilution||See organism-specific panels below.||87186|
|Mycobacterium avium-intracellularae Complex||Broth Microdilution||Effective 11/14/2016
Drugs tested: Amikacin, ciprofloxacin, clarithromycin, doxycycline, ethambutol, ethionamide, isoniazide, linezolid, moxifloxacin, rifabutin, rifampin streptomycin and trimethoprim/sulfamethoxazole (TMP/SXT).
Selective reporting by organism.
Clarithromycin, moxifloxacin and linezolid are the only drugs for which CLSI provides interpretive guidelines. Clarithromycin results predict azithromycin. For Amikacin, only MIC is reported. Because MIC results do not predict clinical response and may be misleading, rifampin, rifabutin, and ethambutol MICs are not routinely reported and must be specifically requested.
|Rapid Growing Mycobacteria||Broth Microdilution||Effective August 17, 2015
Drugs tested: Amikacin, cefoxitin, ciprofloxacin, clarithromycin, doxycycline, imipenem, linezolid, minocycline, moxifloxacin, tigecycline, tobramycin (M. chelonae only), and trimethoprim/sulfamethoxazole (TMP/SXT). Selective reporting by organism.
|Broth Microdilution||Effective May 20, 2013
Drugs tested: Amikacin, ciprofloxacin, clarithromycin, doxycycline, ethambutol, ethionamide, isoniazide, linezolid, moxifloxacin, rifabutin, rifampin, streptomycin and trimethoprim/sulfamethoxazole (TMP/SXT). Selective reporting by organism.
CLSI recommends that isolates of M. kansasii be tested against rifampin and clarithromycin only. Rifampin-susceptible isolates are also susceptible to rifabutin. If the isolate is rifampin-resistant, the following secondary drugs will also be reported: Amikacin, ciprofloxacin, ethambutol, linezolid, moxifloxacin, rifabutin, streptomycin and trimethoprim-sulfamethoxazole.
M. marinum isolates are tested against amikacin, ciprofloxacin, clarithromycin, doxycycline, ethambutol, moxifloxacin, rifabutin, rifampin, and trimethoprim-sulfamethoxazole. Interpretation is based on CLSI guidelines.
Slowly-growing NTM other than M. kansasii and M. marinum are tested against amikacin, ciprofloxacin, clarithromycin, ethambutol, linezolid, moxifloxacin, rifabutin, rifampin, streptomycin, and trimethoprim-sulfamethoxazole.
Interpretive criteria are based on CLSI guidelines for M. kansasii.
Laboratory Developed Test (LDT)
AFB susceptibility testing is billed at the panel level. Charges will vary based on organism identified. An additional handling fee will be billed for all organisms submitted that are not in pure culture as indicated in the specimen requirements. If species identification is not provided, identification will be performed at ARUP. Additional charges apply. M. tuberculosis complex isolates mono-resistant to Pyrazinamide (PZA) will be further identified to species by PCR at an additional charge.
An additional charge will be added for drug requests that are not tested at ARUP and require sendout.
CPT codes vary based on method
|Component Test Code*||Component Chart Name||LOINC|
- Acid Fast Bacilli
- AFB Susceptibility Panel
- Amikacin susceptibility
- Amoxicillin/clavulanic acid susceptibility
- Capreomycin susceptibility
- Cefepime susceptibility
- Cefoxitin susceptibility
- Ceftriaxone susceptibility
- Ciprofloxacin susceptibility
- Clarithromycin susceptibility
- Cycloserine susceptibility
- Doxycycline susceptibility
- Ethambutol susceptibility
- Ethionamide susceptibility
- Imipenem susceptibility
- Isoniazid susceptibility
- Kanamycin susceptibility
- Levofloxacin susceptibility
- Linezolid susceptibility
- Minocycline susceptibility
- Moxifloxacin susceptibility
- Mycobacterium tuberculosis susceptibility testing
- PAS susceptibility
- Pyrazinamide susceptibility
- Rapidly-Growing Mycobacterium species
- Rifabutin susceptibility
- Rifampin susceptibility
- Slow-Growing Mycobacterium species
- Streptomycin susceptibility
- Tigecycline susceptibility
- TMP/SXT susceptibility
- tobramycin (M. chelonae only) susceptibility
- Trimethoprim/sulfamethoxazole susceptibility