AFB Culture for Identification

Analyte(s)

Acid-fast bacilli bacteria (Mycobacteria sp., but can identify other organisms such as Nocardia sp.).

Test Code

3200

Testing Location

Jacksonville Laboratory

Testing Department

Mycobacteriology (TB)

Pre-approval Required?

Pre-approval required for tissue block specimens submitted to the CDC Infectious Disease Pathology Branch (IDPB) Laboratory. Pre-approval must be granted by the CDC IDPB Laboratory.

Required Forms

BPHL Test Requisition, DH1847
(not needed if orders are placed by electronic order)

Minimum Volume

At least 3 mL of liquid media

Turn Around time

6 weeks after receipt at the laboratory

Supply Ordering

Supplies may be requested from your servicing laboratory. Supplies ordered from the BPHL should only be used for specimen sent to the BPHL for testing.

Collection Media

Pure culture of acid-fast bacilli in liquid or solid media (tubes). Do not send Petri dishes.

Specimen Sources

Any clinically relevant specimen source is acceptable

Specimen Labeling

Specimen must be labeled with at least two unique patient identifiers, e.g., name and DOB.

Information on the specimen must match the requisition and/or test order. 

unsatisfactory specimen

1) Formalin fixed or paraffin-embedded tissues
2) No patient identification on specimen tube
3) No specimen observed in specimen container
4) Specimen damaged or leaked entirely in transit
5) Gastric aspirates that have not been neutralized
6) Urine specimens arriving outside of acceptable temperature range
7) AFB smear cannot be performed on blood specimens
8) Samples cross contaminated due to sample leaking in transit

Interferences and Limitations

Mixed cultures, mycobacterial blood culture tubes submitted – presence of blood in the tube may interfere with identification methods and require subculture which will delay reporting of test results. 

Reference Range

Negative (Not Detected)

Result Indicator

Reference lab

CDC MDDR Lab and CDC IDPB Lab 

Reflex testing

Cultures will be identified by PRA or sequencing. Specimens requiring sequencing may have longer than expected turnaround times.

GeneXpert, Deeplex, and MIC susceptibility for each new patient identified with Mycobacterium tuberculosis complex (MTBC).