Acid Fast Bacilli Referred Isolate Identification

Requisition Form

G-MYCO

Test Description

Identification of mycobacterial isolates referred to DSHS Laboratory

Pre-Approval Needed

N/A

Supplemental Information Required

N/A

Supplemental Form(s)

N/A

Performed on Specimens from (sources)

Pure isolate from human sources

Sample/Specimen Type for Testing

Mycobacterium species pure isolate in liquid or on solid culture medium

Minimum Volume/Size Required

• Liquid culture - 2.0 mL

• Solid culture - Single mature colony

Storage/Preservation Prior to Shipping

Ambient

Transport Medium

N/A

Specimen Labeling

• Two patient-specific identifiers required (e.g., patient full name, date of birth, Medical record number)

• Identifiers on specimen must exactly match submission form.

Shipping and Specimen Handling Requirements

• Ship according to Dangerous Goods Regulations, IATA, and/or CFR 49

• Category B shipping applies for unidentified isolates

• Category A shipping applies for Mycobacterium tuberculosis complex

Method

• High performance liquid chromatography (HPLC)

• Subculture for purity and morphological examination

Turn-around Time

2 days for identification

Interferences/Limitations

• HPLC may only detect the predominant organism in a mixed culture.

• Liquid cultures must be instrument positive in order to analyze by HPLC.

Common Causes for Rejection

• Cultures overgrown by contaminating organisms

• Cultures broken in transit

Additional Information

Most isolates can be identified as either M. tuberculosis complex or Mycobacterium species, not M. tuberculosis within 2 to 3 days.