ARUP's Laboratory Test Directory

Antimicrobial Susceptibility - AFB/Mycobacteria : 0060217
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Additional Technical Information
  


Mnemonic: MA AFB

Methodology: Macrobroth Dilution/Microbroth Dilution
Performed: Mon-Fri
Reported: Varies
Specimen Required: Collect: Actively growing isolate in pure culture.

Specimen Preparation: Transport sealed container with pure culture on solid or liquid media. Place each specimen in an individually sealed bag.

Storage/Transport Temperature: Room temperature. If culture is suspected of being a microorganism listed as infectious substance affecting humans on IATA list, submit specimen according to Biological Substance,

Submit specimen according to Infectious Substance, Category A, shipping guidelines.

Unacceptable Conditions: Mixed cultures or non-viable organisms. Organisms submitted on an agar plate.

Stability (collection to initiation of testing): Ambient: 2 weeks; Refrigerated: 2 weeks; Frozen: 2 weeks
Reference Interval:
Available Separately Test Name Methodology Reference Interval/Drugs Tested CPT Code
Yes (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. 		87188 x4
No 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
No Antimicrobial Susceptibility - AFB/Mycobacteria Broth Microdilution See organism-specific panels below. 87186
No Mycobacterium avium-intracellularae Complex 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.

Clarithromycin, moxifloxacin and linezolid are the only drug for which CLSI provides interpretive guidelines. Clarithromycin results predict azithromycin. For drugs other than those listed above there are no CLSI interpretive guidelines; therefore, only MIC is reported. Because MIC results do not predict clinical response, rifampin, rifabutin, and ethambutol MICs are not reported. 		87186
No Rapid Growing Mycobacteria Broth Microdilution Effective May 20, 2013

Drugs tested: Amikacin, amoxicillin/clavulanic acid, cefepime, cefoxitin, ceftriaxone, ciprofloxacin, clarithromycin, doxycycline, imipenem, linezolid, minocycline, moxifloxacin, tigecycline, tobramycin (M. chelonae only), and trimethoprim/sulfamethoxazole (TMP/SXT). Selective reporting by organism. 		87186
No Other Slowly-Growing
Nontuberculosus Mycobacteria
(NTM) 		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.. 		87186

Interpretive Data:

See Compliance Statement B: www.aruplab.com/CS
Note: 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.
Cross References: Acid Fast Bacilli (Antimicrobial Susceptibility - AFB/Mycobacteria), AFB Susceptibility Panel (Antimicrobial Susceptibility - AFB/Mycobacteria), Mycobacterium (Antimicrobial Susceptibility - AFB/Mycobacteria)