MPEP Mycobacterium Tuberculosis Drug Susceptibility Testing – Reports
| Acronym | Definition
|
| AMK | amikacin |
| AP | agar proportion — performed on Middlebrook 7H10 or 7H11 |
| CAP | capreomycin |
| CDC | U.S. Centers for Disease Control and Prevention |
| CIP | ciprofloxacin |
| CLSI | Clinical and Laboratory Standards Institute |
| CYS | cycloserine |
| DNA | deoxyribonucleic acid |
| DST | drug susceptibility testing |
| EMB | ethambutol |
| ETA | ethionamide |
| FQ | fluoroquinolones |
| INH | isoniazid |
| KAN | kanamycin |
| LVX | levofloxacin |
| MDR | multidrug resistant |
| MGIT | BACTEC MGIT 960 – Mycobacteria Growth Indicator Tube |
| MIC | minimum inhibitory concentration |
| MOX | moxifloxacin |
| MPEP | Model Performance Evaluation Program |
| MTBC | Mycobacterium tuberculosis complex |
| PAS | p-aminosalicylic acid |
| PZA | pyrazinamide |
| OFL | ofloxacin |
| R | resistant |
| RBT | rifabutin |
| RIF | rifampin |
| RNA | ribonucleic acid |
| S | susceptible |
| Sensititre | Thermo Scientific Sensititre MYCOTB AST or customized plate |
| STR | streptomycin |
| TB | tuberculosis |
| VersaTREK | Thermo Scientific VersaTREK Myco susceptibility |
| XDR | extensively drug resistant |
The following information pertains to the tables and figures for each MPEP panel’s Final Report.
- First-line and second-line drugs have been separated into individual tables for each isolate. Streptomycin is classified as a second-line drug for this report.
- Separate tables for molecular testing are included.
- Mutations of the rpoB gene are noted with the M. tuberculosis numbering system. Previously M. tuberculosis and E.coli numbering systems were noted.
- Laboratories that use more than one DST method are encouraged to test isolates with each of those methods at either CLSI-recommended or equivalent critical concentrations. Some laboratories have provided results for multiple DST methods. Consequently, the number of results for some drugs may be greater than the number of participating laboratories. This report contains all results reported by participating laboratories.
- The Trek Sensititre system allows determination of a minimum inhibitory concentration (MIC) for each drug in the panel. Laboratories using this method must establish breakpoints to provide a categorical interpretation of S or R.
- For participant result tables for first- and second-line DST that have drug-method totals equal to 0, results were not received or the test was not performed.
- Although data was collected for rifapentine, delamanid, and pretomanid, no laboratories performed growth-based testing for these drugs. Therefore, these drugs were not included in growth-based tables.
(Concentrations listed as µg/ml)
Agar Proportion
| First-line Drugs | 7H10 agar | 7H11 agar |
| Isoniazid | 0.2 and 1.0* | 0.2 and 1.0* |
| Rifampin | 1.0† | 1.0 |
| Ethambutol | 5.0 | 7.5 |
| Pyrazinamide | Not recommended | Not recommended |
NOTE—Critical concentrations as indicated in CLSI M24-A2 document [1]
*The higher concentration of INH should be tested as second-line drug after resistance at the critical concentration is detected [1].
†CLSI critical concentrations for RIF differ from revised WHO recommendation of 0.5 µg/ml published in 2021 [1, 10].
| Second-line Drugs | 7H10 agar | 7H11 agar |
| Streptomycin | 2.0 | 2.0 |
| Levofloxacin | 1.0 | Not determined* |
| Moxifloxacin | 0.5 | 0.5 |
| Amikacin | 4.0† | Not determined* |
| Capreomycin | 10.0† | 10.0¥ |
| Kanamycin | 5.0† | 6.0¥ |
| Ethionamide | 5.0 | 10.0 |
| Rifabutin | 0.5 | 0.5 |
| p-Aminosalicylic acid | 2.0¥ | 8.0¥ |
| Rifapentine | Not determined* | Not determined* |
| Bedaquiline | Not determined* | 0.25‡ |
| Linezolid | 1.0‡ | 1.0‡ |
| Clofazimine | Not determined* | Not determined* |
| Delamanid | Not determined* | 0.016‡ |
| Pretomanid | Not determined* | Not determined* |
NOTE—Critical concentrations as indicated in CLSI M24-A2 document [1]
*Breakpoints for establishing susceptibility have not been determined.
†CLSI critical concentrations differ from revised WHO recommendations published in 2018 [1, 4].
- For AMK, the WHO recommended critical concentration for 7H10 agar is 2.0 µg/ml.
- For CAP, the WHO recommended critical concentration for 7H10 agar is 4.0 µg/ml and ‘Not determined’ for 7H11 agar.
- For KAN, the WHO recommended critical concentration for 7H10 agar is 4.0 µg/ml.
¥WHO has withdrawn the recommended critical concentrations for CAP and KAN for 7H11 agar and PAS for 7H10 and 7H11 [4].
‡Critical concentrations as indicated in WHO 2018 Technical Report on critical concentrations [4].
Broth Based Media
| First-line Drugs | MGIT™ | VersaTREK™ |
| Isoniazid | 0.1 (and 0.4*) | 0.1 (and 0.4*) |
| Rifampin | 1.0† | 1.0 |
| Ethambutol | 5.0 | 5.0 (and 8.0*) |
| Pyrazinamide | 100.0 | 300.0 |
NOTE—Critical concentrations as indicated in applicable manufacturer package inserts
*The higher concentration of INH and EMB should be tested after resistance at the critical concentration is detected [2].
†CLSI critical concentrations for RIF differ from revised WHO recommendation of 0.5 µg/ml published in 2021 [10].
| Second-line Drug | MGITTM |
| Streptomycin | 1.0 (and 4.0*) |
| Levofloxacin | 1.0† |
| Moxifloxacin | 0.25 |
| Amikacin | 1.0 |
| Capreomycin | 2.5 |
| Kanamycin | 2.5 |
| Ethionamide | 5.0 |
| p-Aminosalicylic acid | Not recommended† |
| Rifapentine | Not determined |
| Bedaquiline | 1.0 |
| Linezolid | 1.0 |
| Clofazimine | 1.0 |
| Delamanid | 0.06 |
| Pretomanid | Not determined |
NOTE—Critical concentrations as indicated in WHO 2018 Technical Report on critical concentrations unless noted otherwise [4]. Data for second-line critical concentrations not available for VersaTREK™.
*Critical concentration as indicated in applicable manufacturer package insert. The higher concentration of STR should be tested after resistance at the critical concentration is detected.
†WHO critical concentrations differ from CLSI M62 recommendations published in 2018 [3, 4].
- For LVX, the CLSI recommended critical concentration for MGIT™ is 1.5 µg/ml.
- For PAS, the CLSI recommended critical concentration for MGIT™ is 4.0 µg/ml.