Acid-fast (Mycobacteria) Antibiotic Susceptibilities
(AFB)

Sample type:

• Isolated mycobacteria from primary clinical specimen on media slant or in broth.

Uses:

• Determine the susceptibility of the isolated organism to a profile of antimycobacterial agents.

Precautions:

• Susceptibilities should be performed on the first organism isolated from a patient, and at one- to three-month intervals if that organism continues to be isolated while the patient is on therapy.

• Susceptibility tests should be performed in patients with recurrent tuberculosis as resistant strains are common in recurrent infection.

Interfering Factors:

• Susceptibilities cannot be reported if the organism fails to grow on test media and give false negative.

Pre analytical errors:

1. Inappropriate specimen received.

2. Unlabeled specimen or name discrepancy between specimen and request label;

3. Specimen received after prolonged delay (usually more than 72 hours);

4. Specimen received in expired transport container.

Corrective action:

1. Appropriate specimen received.

2. Labeled specimen and no name discrepancy between specimen and request label.

3. Specimen received without delay.

4. Specimen received in valid transport container.

Post analytical errors:

1. Failure in reporting.

2. Erroneous validation of analytical data.

3. Improper data entry.

Corrective action:

1. Write correct report.

2. All analytical data should be valid.

3. Proper data entrty.