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Epic Test Code LAB246 Mycobacterial Culture, Blood

Additional Codes

MML:CTBBL

Reporting Name

Mycobacterial Culture, B

Useful For

Diagnosing mycobacteremia

Performing Laboratory

Mayo Clinic Laboratories in Rochester

Specimen Type

Whole blood


Shipping 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 Stability Information

Specimen Type Temperature Time
Whole blood Ambient (preferred) 7 days
  Refrigerated  7 days

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)

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.

Supportive Data

During validation of this test, a variety of mycobacteria were recovered from spiked blood specimens. These mycobacteria were Mycobacterium fortuitum, Mycobacterium intracellulare, Mycobacterium kansasii, Mycobacterium tuberculosis, and Mycobacterium xenopi. Mycobacterium genavense was recovered when the medium was supplemented with mycobactin J (an iron supplement). In addition, aerobic actinomycetes including Nocardia farcinica, Gordonia terrae, Rhodococcus equi, and Tsukamurella paurometabola were also recovered when spiked into blood. The limit of detection was determined to be less than or equal to 10(2) colony forming units (CFU)/mL for Mycobacterium fortuitum and Mycobacterium tuberculosis, 10 CFU/mL for Mycobacterium intracellulare, and 1 CFU/mL for Nocardia farcinica.

Report Available

42 days

Specimen Retention Time

24 days

Reject Due To

Blood Culture bottles (eg, BACTEC mycoF Lytic, VersaTrek)
Isolator
Clotted
Reject

Specimen Minimum Volume

5 mL

NY State Approved

Yes

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

Forms

If not ordering electronically, complete, print, and send a Microbiology Test Request (T244) with the specimen.