Mycobacterium tuberculosis Complex Detection and Rifampin Resistance, NAA with AFB Culture

Sputum (adult population) first morning specimen

2 mL of raw or expectorated sputum

2 mL

Sterile screw-capped vial or sterile cup; seal securely

When collecting sputum, have the patient brush teeth or remove dentures and rinse mouth with water. Instruct the patient not to collect saliva.

This test is used to detect and identify Mycobacterium tuberculosis complex and an rpoB mutation that is associated with rifampin resistance.

The assay should not be used to test specimens from patients that have been treated with antituberculous drugs for more than three days. The assay should not be used to monitor therapy or as a test of cure. A negative test does not exclude the possibility of isolating M. tuberculosis complex isolates from culture. Assay interference may occur in the presence of lidocaine, mucin, ethambutol, guaifenesin, phenylephrine, and tea tree oil.

Lower sensitivity may be observed in pediatric patients due to the diffuse nature of Mtb infection in the lungs of this patient group and difficulties encountered in obtaining adequate specimens.

Nucleic acid amplification (NAA), nested real-time polymerase chain reaction (PCR); concentrated specimen with broth-based and/or agar-based culture. Culture is held for six weeks before negative is reported. Organisms from culture are identified by use of real-time polymerase chain reaction (PCR) and/or MALDI-TOF and/or nucleic acid sequencing.