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22494 Culture, Mycobacteria

Culture, Mycobacteria
Test Code: AFB
Synonyms/Keywords
TB Culture, AFB Culture​, Mycobacteria, Mycobacterial, Acid fast bacilli
Test Components

This test includes a smear exam.

Specimen Requirements
Fasting Required Specimen Type Preferred Container/Tube Acceptable Container/Tube Specimen Volume Specimen Minimum Volume
(allows for 1 repeat)		 Pediatric Minimum Volume
(no repeat)
No​
Any
(except blood and bone marrow)​
Sterile leakproof containers without preservatives
(e.g. Sage container)​
5-10 mL​
1 mL fluids and secretions
 
0.5 g tissues
​		 ​
Collection Processing Instructions

Specimens should be delivered to the microbiology laboratory as soon as possible. Culture of specimens older than 24 hours may lead to a reduction in recovery of microorganisms. Do not freeze specimens at -20°C, or in a frost-free freezer.

Specimens should be collected in sterile leakproof containers without preservatives. A sterile anticoagulant such as heparin or SPS may be used in collection tubes to prevent clots in body fluids. 

For sputum, three samples are recommended (one early morning from deep cough or expectorated sputa induced by aerosolization) eight to twelve hours apart. For urine, three specimens, one per day for three consecutive days are recommended. For gastric lavage fluid, three early morning specimens collected on separate days are recommended.  Volumes >15 mL will NOT be accepted. For blood and bone marrow mycobacteria culture, see CULTURE, MYCOBACTERIA, BLOOD.

Acceptable Specimen Types
​Bone, Bronchial, Catheter Tip, Environmental, Feces, Fine Needle Aspirate, Fluid, Hardware, Milk, Respiratory Secretions, Synovial, Tissue, or Urine.
Specimen Stability Information
Specimen Type Temperature Time
CSF​ Room Temperature​ NA
All other specimen types​ Room temperature ​ <= 1 hour
Refrigerate​ > 1 hour
Rejection Criteria
Pooled sputum or urine
Dried swabs or tissues​
Specimens submitted in formalin or other preservatives​
Gastric lavage specimens >4 hours old or >15 mL in volume​
Specimens older than 4 days​
​Leaking specimens

​Specimens received on swabs
Performing Laboratory Information
Performing Location Day(s) Test Performed Analytical Time Methodology/Instrumentation
Marshfield​ Monday through Friday​ ​​6 weeks

Conventional culture, microscopic exam with mycobacteria-specific stain, standard susceptibility testing, manual or automated identification methods, and nucleic acid sequence analysis as needed

Test Information
The mycobacterial load in a clinical specimen may be low. Specimens with less than the recommended volumes may therefore lead to a false negative result.
 
Prior antimycobacterial therapy or an inadequate volume of specimen may impact correlation of positive smears with positive cultures.
 
First time positive M. tuberculosis isolates are routinely submitted for susceptibility testing at an additional charge.  All other isolates will receive susceptibility testing only upon provider's request.

Reference Range Information
Performing Location Reference Range
All Performing Sites

Concentrated/unconcentrated specimen negative for acid-fast bacilli

Culture negative for acid-fast bacilli​

See Critical Value List for list of current critical values.​ ​
Interpretation
If a positive smear is detected on any patient without a history of mycobacterial infection, the specimen will be submitted to the Wisconsin State Laboratory of Hygiene for TB-PCR testing.  This testing is performed free of charge.
Outreach CPTs
CPT Modifier
(if needed)		 Quantity Description Comments
87116​ ​ ​ Culture​ ​
87206​ ​ ​ Smear​ ​
87118​ ​ ​ Mycobacteria definitive identification, as needed ​
​87153 ​ ​ ​Identification by nucleic acid sequencing method, as needed ​

​87015
​​​Specimen concentration, as needed​
​
Synonyms/Keywords
TB Culture, AFB Culture​, Mycobacteria, Mycobacterial, Acid fast bacilli
Test Components

This test includes a smear exam.

Ordering Applications
Ordering Application Description
​Cerner
 ​Acid Fast Bacilli Culture w/stain


If the ordering application you are looking for is not listed, contact your local laboratory for assistance.
Specimen Requirements
Fasting Required Specimen Type Preferred Container/Tube Acceptable Container/Tube Specimen Volume Specimen Minimum Volume
(allows for 1 repeat)		 Pediatric Minimum Volume
(no repeat)
No​
Any
(except blood and bone marrow)​
Sterile leakproof containers without preservatives
(e.g. Sage container)​
5-10 mL​
1 mL fluids and secretions
 
0.5 g tissues
​		 ​
Collection Processing

Specimens should be delivered to the microbiology laboratory as soon as possible. Culture of specimens older than 24 hours may lead to a reduction in recovery of microorganisms. Do not freeze specimens at -20°C, or in a frost-free freezer.

Specimens should be collected in sterile leakproof containers without preservatives. A sterile anticoagulant such as heparin or SPS may be used in collection tubes to prevent clots in body fluids. 

For sputum, three samples are recommended (one early morning from deep cough or expectorated sputa induced by aerosolization) eight to twelve hours apart. For urine, three specimens, one per day for three consecutive days are recommended. For gastric lavage fluid, three early morning specimens collected on separate days are recommended.  Volumes >15 mL will NOT be accepted. For blood and bone marrow mycobacteria culture, see CULTURE, MYCOBACTERIA, BLOOD.

Acceptable Specimen Types
​Bone, Bronchial, Catheter Tip, Environmental, Feces, Fine Needle Aspirate, Fluid, Hardware, Milk, Respiratory Secretions, Synovial, Tissue, or Urine.
Specimen Stability Information
Specimen Type Temperature Time
CSF​ Room Temperature​ NA
All other specimen types​ Room temperature ​ <= 1 hour
Refrigerate​ > 1 hour
Rejection Criteria
Pooled sputum or urine
Dried swabs or tissues​
Specimens submitted in formalin or other preservatives​
Gastric lavage specimens >4 hours old or >15 mL in volume​
Specimens older than 4 days​
​Leaking specimens

​Specimens received on swabs
Test Components

This test includes a smear exam.

Reference Range Information
Performing Location Reference Range
All Performing Sites

Concentrated/unconcentrated specimen negative for acid-fast bacilli

Culture negative for acid-fast bacilli​

See Critical Value List for list of current critical values.​ ​
Interpretation
If a positive smear is detected on any patient without a history of mycobacterial infection, the specimen will be submitted to the Wisconsin State Laboratory of Hygiene for TB-PCR testing.  This testing is performed free of charge.
For more information visit:
Performing Laboratory Information
Performing Location Day(s) Test Performed Analytical Time Methodology/Instrumentation
Marshfield​ Monday through Friday​ ​​6 weeks

Conventional culture, microscopic exam with mycobacteria-specific stain, standard susceptibility testing, manual or automated identification methods, and nucleic acid sequence analysis as needed

For billing questions, see Contacts
Outreach CPTs
CPT Modifier
(if needed)		 Quantity Description Comments
87116​ ​ ​ Culture​ ​
87206​ ​ ​ Smear​ ​
87118​ ​ ​ Mycobacteria definitive identification, as needed ​
​87153 ​ ​ ​Identification by nucleic acid sequencing method, as needed ​

​87015
​​​Specimen concentration, as needed​
​
For most current information refer to the Marshfield Laboratory online reference manual.