Mycobacterium tuberculosis Complex Detection and Rifampin Resistance (PCR), Acid-fast Bacillus (AFB) Smear, and AFB Culture With Reflex to Identification (Nonsputum)
Use
This test is used to detect and identify Mycobacterium tuberculosis complex and an rpoB mutation that is associated with rifampin resistance.
Special Instructions
Specimen processing can include N-acetyl-L-cystine-sodium hydroxide treatment or equivalent, concentration, and grinding. Mycobacterial culture and smear are included where appropriate, though smears are not performed on blood or when fluid is less than 2 mL. Additional charges apply for identification by real-time PCR, MALDI-TOF mass spectrometry, or nucleic acid sequencing. This culture may also detect Nocardia species and other aerobic actinomyces.
Limitations
The assay should not be used for patients treated with antituberculous drugs for more than three days, nor for monitoring therapy or as a test of cure. A negative result doesn't rule out the presence of M. tuberculosis complex from culture. Interference may occur with substances like lidocaine and tea tree oil. Lower sensitivity is found in pediatric patients due to difficult specimen collection and diffuse infection nature.
Methodology
PCR-based (RT-PCR)
Biomarkers
LOINC Codes
- 38379-4
- 50941-4
- 31208-2
- 38379-4
- 89372-7
- 8100-0
- 11545-1
Result Turnaround Time
48-56 days
Related Documents
For more information, please review the documents below
Specimen
Bronchoalveolar Lavage
Volume
5 mL
Minimum Volume
5 mL
Container
Sterile container with screw-cap seal
Storage Instructions
Refrigerate. If sample is to be split for other tests, divide at time of collection so each portion is transported at the appropriate temperature.
Causes for Rejection
Quantity not sufficient; inappropriate specimen source; specimen on a swab; leaked specimen; inappropriate transport device; syringe with needle; unlabeled or mismatched specimen.
Stability Requirements
| Temperature | Period |
|---|---|
| Refrigerated | 7 days |