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HelpTest ID MTBPZ Mycobacterium tuberculosis Complex, Pyrazinamide Resistance by pncA DNA Sequencing, Varies
Infectious
Shipping Instructions
1. See Infectious Specimen Shipping Guidelines.
2. Place specimen in a large infectious container (T146) and label as an etiologic agent/infectious substance.
Necessary Information
Specimen source and suspected organism identification are required.
Specimen Required
Specimen Type: Organism
Supplies: Infectious Container, Large (T146)
Container/Tube: Middlebrook 7H10 agar slant
Specimen Volume: Isolate
Collection Instructions: Organism must be in pure culture, actively growing.
Forms
If not ordering electronically, complete, print, and send a Microbiology Test Request (T244) with the specimen.
Secondary ID
56099Useful For
Detection of genotypic resistance to pyrazinamide by Mycobacterium tuberculosis complex isolates
Reflex Tests
| Test ID | Reporting Name | Available Separately | Always Performed |
|---|---|---|---|
| MTBVP | Mtb PZA Confirmation, pnc A Sequence | No, (Bill Only) | No |
Testing Algorithm
When this test is ordered, the reflex test may be performed and charged.
Special Instructions
Method Name
DNA Sequencing
Reporting Name
Mtb PZA Resistance, pncA SequencingSpecimen Type
VariesSpecimen Stability Information
| Specimen Type | Temperature | Time |
|---|---|---|
| Varies | Ambient (preferred) | |
| Refrigerated | ||
Clinical Information
The protein product of the Mycobacterium tuberculosis complex pncA gene is an enzyme that is responsible for activation of the prodrug pyrazinamide (PZA). DNA sequencing of the Mycobacterium tuberculosis complex pncA gene can be used to detect mutations that correlate with in vitro PZA resistance.(1,2) The sequencing result can be available in as little as 1 day after the Mycobacterium tuberculosis complex isolate grows in culture, thereby providing a more rapid susceptibility result than the average 10 to 14 days required by phenotypic broth methods.
Reference Values
Pyrazinamide resistance not detected
Cautions
According to the literature,(3) 72% to 97% of pyrazinamide (PZA)-resistant clinical isolates carry mutations in the pncA gene or promoter region. However, other resistance mechanisms (eg, changes in PZA uptake or increased PZA efflux) will not be detected by this method.
Correlation of the in vitro sequencing result with clinical presentation is strongly recommended.
Day(s) Performed
Varies
Report Available
7 to 21 daysPerforming Laboratory
Mayo Clinic Laboratories in Rochester
Test Classification
This test was developed and its performance characteristics determined by Mayo Clinic in a manner consistent with CLIA requirements. It has not been cleared or approved by the US Food and Drug Administration.CPT Code Information
87153-Mtb PZA Confirmation, pncA Sequence