Mycobacterium tuberculosis Complex Detection and Rifampin Resistance, NAA With AFB Culture
Use
This test is used to detect and identify Mycobacterium tuberculosis complex and an rpoB mutation that is associated with rifampin resistance.
Special Instructions
The culture is held for six weeks before a negative result is reported. For optimal results, collect the first morning sputum sample, have the patient brush their teeth, or remove dentures and rinse their mouth before collection.
Limitations
This assay should not be used to test specimens from patients treated with antituberculous drugs for more than three days. It is not intended for therapy monitoring or as a test of cure. Negative results do not exclude the possibility of isolating M. tuberculosis complexes from culture. Interference may occur with substances like lidocaine, mucin, ethambutol, guaifenesin, phenylephrine, and tea tree oil. Lower sensitivity may be observed in pediatric patients due to the diffuse nature of the infection and specimen collection challenges.
Methodology
PCR-based (Nested real-time PCR)
Biomarkers
LOINC Codes
- 89371-9
- 14556-5
- 33634-7
- 8100-0
- 50941-4
Result Turnaround Time
48-56 days
Related Documents
For more information, please review the documents below
Specimen
Sputum
Volume
2 mL
Minimum Volume
2 mL
Container
Sterile screw-capped vial or sterile cup; seal securely
Patient Preparation
When collecting sputum, have the patient brush teeth or remove dentures and rinse mouth with water. Instruct the patient not to collect saliva.
Storage Instructions
Refrigerate. If sample is to be split for other tests, specimen should be divided at the time of collection so that each portion is transported at the appropriate temperature.
Causes for Rejection
Quantity not sufficient; inappropriate specimen source (i.e., not sputum); specimen received after leaking out of transport container into the specimen bag; inappropriate transport device; unlabeled specimen container or container with a single patient identifier; name discrepancy between the specimen container label and the computer or the requisition; specimen received after prolonged delay (more than seven days); specimen in a paraffin block; specimen in a fixative; specimen at room temperature received after 72 hours; specimen submitted frozen
Stability Requirements
| Temperature | Period |
|---|---|
| Refrigerated | 7 days |