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HelpTest Code CTBBL Mycobacterial Culture, Blood
Reporting Name
Mycobacterial Culture, BUseful For
Diagnosing mycobacteremia
Reflex Tests
| Test ID | Reporting Name | Available Separately | Always Performed |
|---|---|---|---|
| ISMY | ID by 16S Sequencing | No, (Bill Only) | No |
| RMALM | Id MALDI-TOF Mass Spec AFB | No, (Bill Only) | No |
| RTBSP | Id, Mtb Speciation, PCR | No, (Bill Only) | No |
| LCTB | Id, MTB complex Rapid PCR | No, (Bill Only) | No |
Testing Algorithm
When this test is ordered, the reflex tests may be performed at an additional charge.
Method Name
Continuously Monitored Automated Broth Culture Instrument with Conventional Methods for Identification of Mycobacteria
Performing Laboratory
Mayo Clinic Laboratories in Rochester
Specimen Type
Whole bloodShipping Instructions
Specimen must be processed within 7 days of collection.
Necessary Information
Specimen source is required.
Specimen Required
Container/Tube:
Preferred: Green top (sodium or lithium heparin)
Acceptable: SPS (sodium polyanethol sulfonate)
Specimen Volume: 8 to 10 mL per culture
Collection Instructions:
1. Send whole blood specimen in original tube.
2. SPS tubes are acceptable, but not preferred.
3. Note: SPS tubes must be clearly labeled as SPS. If label is obscured, sample may be canceled, as ACD (yellow top) is not an acceptable tube type.
Specimen Minimum Volume
5 mL
Specimen Stability Information
| Specimen Type | Temperature | Time |
|---|---|---|
| Whole blood | Ambient (preferred) | 7 days |
| Refrigerated | 7 days |
Reject Due To
| Blood Culture bottles (eg, BACTEC mycoF Lytic, VersaTrek) Isolator Clotted |
Reject |
Reference Values
Negative
If positive, mycobacteria are identified.
A final negative report will be issued after 42 days of incubation.
Day(s) Performed
Monday through Sunday
CPT Code Information
87116-Mycobacterial Culture
87118-Id MALDI-TOF Mass Spec AFB (if appropriate)
87150-Id, Mtb Speciation, PCR (if appropriate)
87150-Mycobacteria Probe Ident, Solid (if appropriate)
87153-Mtb PZA Confirmation, pcnA sequence (if appropriate)
87153-Mycobacteria Identification by Sequencing (if appropriate)
87150- Id, MTB complex Rapid PCR (if appropriate)
LOINC Code Information
| Test ID | Test Order Name | Order LOINC Value |
|---|---|---|
| CTBBL | Mycobacterial Culture, B | 64412-0 |
| Result ID | Test Result Name | Result LOINC Value |
|---|---|---|
| CTBBL | Mycobacterial Culture, B | 64412-0 |
Clinical Information
Mycobacteremia occurs most often in immunocompromised hosts. The majority of disseminated mycobacterial infections are due to Mycobacterium avium complex but bacteremia can also be caused by other mycobacterial species including, but not limited to, Mycobacterium tuberculosis complex, Mycobacterium kansasii, Mycobacterium fortuitum, Mycobacterium chelonae, Mycobacterium scrofulaceum, Mycobacterium szulgai, and Mycobacterium xenopi.(1)
Mycobacterial blood cultures may be indicated for patients presenting with signs and symptoms of sepsis, especially fever of unknown origin.
Interpretation
A positive result may support the diagnosis of mycobacteremia.
Cautions
Results must be interpreted in conjunction with the patient's history and clinical picture.
A negative result does not rule out mycobacteremia. The organism may be present at quantities below the limit of detection or may be transiently present.
If Mycobacterium genavense is suspected, indicate on request form or contact laboratory. Mycobactin J (an iron supplement) will then be added to the culture to support growth.
Method Description
The blood is processed per the manufacturer's instructions before adding it to a VersaTREK Myco bottle and plating onto Middlebrook 7H10 agar. The agar plate is incubated at 37° C with 5% to 7% carbon dioxide for 42 days. The VersaTREK Myco bottle is incubated on the automated VersaTREK 528 instrument for 42 days. If the bottle signals as positive on the instrument, it is removed, and a smear is performed to look for acid-fast organisms. Acid-fast organisms are identified using conventional methods including real-time PCR, matrix-assisted laser desorption/ionization time-of-flight mass spectrometry, and 16S rDNA gene sequencing.(Mirrett S, Hanson KE, Reller LB. Controlled clinical comparison of VersaTREK and BacT/ALERT blood culture systems. J Clin Microbiol. 2007;45(2):299-302; Buckwalter SP, Olson SL, Connelly BJ, et al. Evaluation of Matrix-Assisted Laser Desorption Ionization-Time of Flight Mass Spectrometry for the Identification of Mycobacterium species, Nocardia species, and Other Aerobic Actinomycetes. J Clin Microbiol. 2016;54(2):376-384. doi:10.1128/JCM.02128-15; Hall L, Doerr KA, Wohlfiel SL, Roberts GD. Evaluation of the MicroSeq system for identification of mycobacteria by 16S ribosomal DNA sequencing and its integration into a routine clinical mycobacteriology laboratory. J Clin Microbiol. 2003;41(4):1447-1453)