Advanced Diagnostic Laboratories

Collect

Submit a slant or = 2.0 mL of a broth culture. Specify the type of media used.

Unacceptable Conditions

Mixed cultures or non-viable organisms; there is an additional charge for purification/isolation of cultures containing a non-acid-fast contaminant, or more than one mycobacterial species.

Storage Transport Temp

Room temperature.

Notes

• This test code is for identification of a positive AFB culture. Indicate specimen source of organism and any other pertinent information such as the growth rate of the organism, growth temperature, DNA probe results, or preliminary identification. The laboratory should be notified when the presence of M. genavense, M. haemophilum and other fastidious mycobacteria are suspected, as these organisms will not grow on media routinely used for subcultures.
• If colony morphology on a solid medium resembles Mycobacterium tuberculosis (MTB) complex, a line probe assay to detect M. tuberculosis complex will be performed. If positive, first-line drug antimicrobial susceptibility testing (AST; MTB2) will be performed on all initial isolates. The laboratory will provide at no charge a subculture to the respective state laboratory for genotyping upon request.
• A line probe assay to rule out the presence of M. tuberculosis will be performed on ALL liquid cultures submitted without preliminary identification unless a clinical history indicating nontuberculous mycobacterial (NTM) infection is provided or indicated on the requisition that M. tuberculosis has been ruled out.
• All other mycobacteria will be identified using DNA sequencing (i.e., rpoB gene and 16S rRNA gene sequencing).
• Additional distinction within the group Mycobacterium abscessus can be made using molecular assays for erm(41) and hsp65 genes, which will be ordered after preliminary identification of M. abcessus group. This will also be performed if M. abcessus group is identified by our laboratory.
• Submission of a confirmed pure culture is required.

There is an additional charge for purification/isolation of cultures containing a non-acid-fast contaminant, or more than one mycobacterial species.