AFB Mycobacterium tuberculosis Direct Susceptibility Test  

IMPORTANT! Pre-approval needed from state or local health department. Local or State Health Department. Send approval to or call (402) 559-9444.

NPHL has moved to an electronic ordering system, NUlirt, and it is now the preferred method to order all tests. Once ordered, print a "batch list" (see NUlirt Guide).

Forms Required - Nulirt batch list or NPHL Test Request Form (completed in entirety) must accompany the specimen to include the following information: symptoms and date of onset, pregnancy status, travel and vaccine history. Testing will not be performed without all required information.

Please call NPHL Client Services at (402) 559-2440 or toll free at (800) 334-0459 for further clarification.


Test: AFB Mycobacterium tuberculosis Direct Susceptibility Test Supplemental Forms Required – Mycobacterium tuberculosis (MTB) Supplemental  
Synonym: DST, Pyrosequencing, PSQ  
Method: Prosequencing of katG, inhA, ahpC, rpoB RRDR, gyrA and rrs genes.  
Availability: Monday - Thursday  
Specimen: 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  
Volume: 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:

Unacceptable: 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  
Comments: 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 
If you have questions about proper specimen collection, please call NPHL Client Services at (402) 559-2440 or toll free at (800) 334-0459.