AFB Mycobacterium tuberculosis Direct Susceptibility Test

Supplemental Forms Required – Mycobacterium tuberculosis (MTB) Supplemental


DST, Pyrosequencing, PSQ


Prosequencing of katG, inhA, ahpC, rpoB RRDR, gyrA and rrs genes.


Monday - Thursday


Nucleic Acid Amplification positive (NAA+) sediment; pure culture isolate on solid medium (isolate submitted for confirmation of an Xpert MTB/RIF should result as "RIF resistance detected")

  Collection Device:

Sediment in centrifuge tube or leak-proof container. Isolate on Lowen-Stein Jensen media

Specimen Labeling: Test subject to CLIA regulations and required 2 patient identifiers on specimen container and requisition forms


0.5 mL (sediment)


Prior to and during shipment: Refrigerated at 2-8 °C. Place each individual specimen in a sealed bag.

Shipping instructions, including specimen-handling requirements during transport: Shipping instructions, including specimen-handling requirements during transport: Sender must contact the NPHL by email or phone before shipping. All screw-top tubes must be sealed with parafilm or tape. Vacutainer tubes do not require parafilm or tape to seal, Fluids that have potential to be Category A must be packaged UN 2814 Infectious Substances, affecting humans (Category A) and shipped via FedEx. Omaha & Lincoln laboratories can ship via NPHL ground courier by calling client services (866) 290-1406 to request exclusive Category A courier. See instructions and shipping address: http://nphl.org/


Sediment should not be shipped frozen.

  Specimen Stability:

Sediment should be refrigerate at 2-8°C, keep isolate at room temperature.

  Reference Interval:

Sensitive or Resistant

  Reportable Disease:

MTB complex will be reported immediately to local or state health department. Refer to Nebraska DHHS Title 173, Communicable Diseases


First-Line DST using MGIT with a panel of rifampin, isoniazid, pyrazinamide and ethambutol.

Second-Line DST using MGIT with a panel of ethionomide, capreomycin, amikacin, moxifloxacin, kanamycin and rifabutin

Molecular detection of drug resistance will be performed by pyrosequencing on specimen sediments and isolates from patients that meet pre-determined criteria for suspicion of drug resistance.  Submitting laboratories should keep a small, 1 mL aliquot in their laboratory.  Test performed at Microbial Diseases Laboratory California Department of Public Health 850 Marina Bay Parkway Richmond, CA

  Revised: 9/4/2020