Sign in →

Test Code LAB8974 Susceptibility, Mycobacterium tuberculosis Complex, Pyrazinamide, Varies

Infectious

Additional Codes

TBPZA

Test Down Notes

This test is temporarily unavailable. For additional details, see test update here 


Ordering Guidance


To test for first-line agents, isoniazid, rifampin and ethambutol, order TB1LN / Antimicrobial Susceptibility, Mycobacterium tuberculosis Complex, First Line, Varies.

 

Isolates identified as Mycobacterium bovis and Myocobacterium bovis bacille Calmette-Guerin (BCG) will not be accepted as they are intrinsically resistant to pyrazinamide.



Additional Testing Requirements


If organism identification is not provided, CTB / Mycobacteria and Nocardia Culture, Varies or CTBID / Culture Referred for Identification, Mycobacterium and Nocardia, Varies must also be ordered and will be charged separately.



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.

Useful For

Susceptibility testing of Mycobacterium tuberculosis complex isolates growing in pure culture against pyrazinamide

 

This test is not useful for Mycobacterium bovis and Myocobacterium bovis bacille Calmette-Guerin (BCG) isolates as they are intrinsically resistant to pyrazinamide.

Additional Tests

Test ID Reporting Name Available Separately Always Performed
STVP Susceptibility, Mtb Complex, PZA No, (Bill Only) Yes

Reflex Tests

Test ID Reporting Name Available Separately Always Performed
MTBVP Mtb PZA Confirmation, pnc A Sequence No, (Bill Only) No

Testing Algorithm

If resistance to pyrazinamide is detected, the reflex sequencing test or confirmation of resistance will be performed at an additional charge.

 

If the broth microdilution test is unable to be performed (eg, due to reagent shortages, failure of the isolate to grow in the test medium), the reflex sequencing test will be performed at an additional charge.

Method Name

Broth Dilution at Critical Drug Concentrations

Specimen Type

Varies

Specimen Stability Information

Specimen Type Temperature Time Special Container
Varies Ambient (preferred)
  Refrigerated 

Reject Due To

Agar plate Reject

Reference Values

Results are reported as susceptible or resistant.

Interpretation

Mycobacterium tuberculosis complex isolates are reported as susceptible or resistant to pyrazinamide at the critical concentration.

Method Description

This test is based on presence or absence of growth of an Mycobacterium tuberculosis complex isolate in broth cultures in the presence of critical concentrations of the antimycobacterial drug pyrazinamide. One of two FDA-cleared platforms (BD MGIT 960 or the VersaTREK) will be used. (Brown-Elliott, BA, Cirillo DM, Musser KA, Rowlinson M-C. Susceptibility Test Methods: Mycobacteria, Nocardia, and Other Actinomycetes. In: Carroll KC, Pfaller MA, eds. Manual of Clinical Microbiology, 13th Edition. ASM Press, 2023)

 

The BACTEC MGIT 960 platform measures fluorescence in a Mycobacterial Growth Indicator Tube (MGIT) containing an M tuberculosis complex isolate in the presence of a critical concentrations of pyrazinamide (Package insert: BACTEC MGIT 960 SIRE Kit, BD Diagnostics, 9/2019)

 

The VersaTrek platform inside bottles containing M tuberculosis complex isolates in the presence of a critical concentration of the antimycobacterial PZA. (Package insert: VersaTREK Mycobacteria Detection and Susceptibility Testing system, TREK Diagnostics, 04/2014)

Day(s) Performed

Monday through Sunday

Report Available

10 to 21 days

Specimen Retention Time

1 year

Performing Laboratory

Mayo Clinic Laboratories in Rochester

CPT Code Information

87188-Susceptibility, Mycobacterium tuberculosis Complex, Pyrazinamide

87153-Mtb PZA Confirmation, pncA Sequencing (if appropriate)

LOINC Code Information

Test ID Test Order Name Order LOINC Value
TBPZA Susceptibility, Mtb Complex, PZA 56026-8

 

Result ID Test Result Name Result LOINC Value
TBPZA Susceptibility, Mtb Complex, PZA 56026-8

Secondary ID

34549