Menu of Individual Drug Testing for Acid Fast Bacilli
Test Code
NTM3, NTM5 and MTB6
Description
The Mycobacteriology Laboratory can perform a customized selection of phenotypic antibiotic susceptibility testing for mycobacteria and partially acid fast organisms. The client must select the drugs to be tested (Note: for the routine panel of drugs, use APPRO instead of selecting individual drugs).
Individual drug testing is generally ordered when newer drugs are needed that are not part of the routine panel, or a specific selection of drugs is desired. Table 1 contains all testable drugs that may be selected for various types of organisms.
Table 1. Full menu of antibiotic susceptibility testing that may be individually ordered for various mycobacteria and acid fast organisms
| Slowly growing mycobacteria (Test code: NTM3) |
Rapidly growing mycobacteria (Test code: NTM5) |
Mycobacterium tuberculosis (Test code: MTB6) |
M. haemophilum (Test code: NTM3) |
| Amikacin Ciprofloxacin Clofazimine Clarithromycin Doxycycline Ethambutol Linezolid Minocycline Moxifloxacin Rifabutin Rifampin Rifampin/Ethambutol Synergy Streptomycin Trimethoprim/sulfamethoxazole |
Amikacin Augmentin Azithromycin Cefepime Cefotaxime Cefoxitin Ceftriaxone Ciprofloxacin Clarithromycin Clofazimine Clofazimine/Amikacin Doxycycline Gentamicin Imipenem Kanamycin Linezolid Minocycline Omadacycline Moxifloxacin Tigecycline Tobramycin Trimethoprim/sulfamethoxazole |
Amikacin Bedaquiline Capreomycin Ethambutol Ethionamide Isoniazid Linezolid Levofloxacin Moxifloxacin Ofloxacin Pyrazinamide (MIC) Rifabutin Rifampin Streptomycin |
Clofazimine Linezolid |
Table 1. Drug abbreviations (used on the requisition)
| Abbreviation | Drug | Abbreviation cont'd | Drug cont'd |
| AMK | Amikacin | INH | Isoniazid |
| AUG | Augmentin | IPM | Imipenem |
| AXO | Ceftriaxone | KAN | Kanamycin |
| AZM | Azithromycin | LZD | Linezolid |
| BDQ | Bedaquiline | MIN | Minocycline |
| CIP | Ciprofloxacin | MXF | Moxifloxacin |
| CLO | Clofazimine | OFX | Ofloxacin |
| CLO/AMK | Clofazimine/Amikacin | OMC | Omadacycline |
| CLR | Clarithromycin | PAS | p-Aminosalicyclic acid |
| CAP | Capreomycin | PZA | Pyrazinamide |
| CS | Cycloserine | RFB | Rifabutin |
| DOX | Doxycycline | RIF | Rifampin |
| EMB | Ethambutol | RIF/EMB | Rifampin & Ethambutol synergy |
| ETH | Ethionamide | STR | Streptomycin |
| FEP | Cefepime | TGC | Tigecycline |
| FOT | Cefotaxime | TMP/SXT | Trimethoprim/sulfamethoxazole |
| FOX | Cefoxitin | TOB | Tobramycin |
| GEN | Gentamicin | - | - |
Collect
An identified isolate is required for testing (does not necessarily apply to veterinary rapidly growing isolates).
- This test can be ordered on a clinical specimen that has been sent to our laboratory for isolation and identification of mycobacteria. See specimen requirements for culture of mycobacteria from a clinical specimen (AFB1, AFB3 or AFB7)
- This test can also be ordered on organisms identified elsewhere. Pure mycobacterial isolates should be sent in solid media such as a Middlebrook slant (7H10 or 7H11), Lowenstein-Jensen (LJ) slant, or in broth (7H9, MGIT, MP BACT/Alert, VersaTrek).
- Specimen Volume: Laboratory must receive visible growth of an isolate on solid media or an isolate in broth media (≥ 3 mL).
Unacceptable Conditions
- Cultures received with incomplete identifiers.
- Mixed cultures; Note that prior to rejection, attempts will be made to isolate organisms. A re-isolation charge will be applied in these cases.
- Cultures containing mold.
- Solid media with insufficient growth.
- Cultures submitted on agar plates.
- Liquid media with < 2 mL.
- Leaking specimens.
Storage Transport Temp
Transport or mail isolates at ambient temperature. For nontuberculous mycobacteria (NTM), follow IATA/ DOT category B and for M. tuberculosis complex isolates, follow IATA/DOT category A requirements for shipping biological materials.
Stability
Isolate at ambient temperature
Performed
Typically all days
Methodology
| Test code | Type of organism | Drugs available | Method |
| NTM3 | Slowly growing mycobacteria | AMK, CIP, CLO, CLR, DOX, EMB, LZD, MIN, MXF, RIF, RFB, STR, TMB/SXT | Broth microdilution |
| RIF/EMB synergy | Broth microdilution | ||
| CLO, LZD | Agar proportion | ||
| NTM5 | Rapidly growing mycobacteria | AMK, AUG, AXO, AZI, CIP, CLO, CLO/AMK Synergy, CLR, DOX, FEP, FOT, FOX, GEN, IMP, KAN, LZD, MIN, MXF, TGC, TOB, TMP/SXT | Broth microdilution |
| MTB6 | Mycobacterium tuberculosis | BDQ, ETH | Agar proportion |
| AMK, CAP, EMB, ETH, INH, LFX, LZD, MXF, OFX, PZA, RIF, RFB, STR | Broth proportion |
Turnaround Time
- MIC's for M. tuberculosis complex and other slowly growing mycobacteria are reported 4 to 6 weeks after a pure culture is achieved.
- MIC's for rapidly growing mycobacteria and aerobic actinomycetes are reported 2 to 3 weeks after a pure culture is achieved.
Department
Infectious Disease Laboratory, Mycobacteriology
Study Offerings
CAP/CLIA
Related Tests
NTM13, AFB6, MTB1, MTB2, NTM4, NTM6, NTM15, TNGS
Interpretation
For MIC methods, an MIC will be provided. Susceptible, intermediate, or resistant (S, I, R) interpretations will be included whenever guidelines are available for a drug-organism combination, or NI will be reported if no interpretation is available. CLSI guidelines are used for NTM; WHO and CLSI guidelines are used for MTBC.
CPT Code
| Test code | Type of organism | Drugs available | Method | Billing Code | CPT code |
| NTM3 | Slowly growing mycobacteria | AMK, CIP, CLO, CLR, DOX, EMB, LZD, MIN, MXF, RIF, RFB, STR, TMB/SXT | Broth microdilution | MICSD | 87186 |
| RIF/EMB synergy | Broth microdilution | NTMP9 | 87186 | ||
| CS, CLO, LZD | Agar proportion | APSD | 87181 | ||
| NTM5 | Rapidly growing mycobacteria | AMK, AUG, AXO, AZI, CIP, CLO, CLO/AMK Synergy, CLR, DOX, FEP, FOT, FOX, GEN, IMP, KAN, LZD, MIN, MXF, TGC, TOB, TMP/SXT | Broth microdilution | NTMP6 or NTMPV (for veterinary) | 87186 |
| MTB6 | Mycobacterium tuberculosis | ETH, BDQ | Agar proportion | MTBP1 | 87190 |
| INH, RIF, ETH, PZA | Broth proportion | MTPB2 | 87188 | ||
| AMK, CAP, EMB, ETH, INH, LFX, LZD, MXF, OFX, PZA, RIF, RFB, STR | Broth proportion | MTBP3 | 87188 |
New York Approved
Standard
FDA
Standard Method