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HelpTest ID CTB Mycobacteria and Nocardia Culture
Useful For
Detection and identification of Mycobacteria species, Nocardia species and other aerobic actinomycetes
Identification is performed using the Hologic/GenProbe AccuProbes for selected Mycobacteria species, MALDI-TOF mass spectrometry, or 500 base pair 16S rRNA gene sequencing.
Mycobacterium tuberculosis complex species identification can be done upon request using rapid PCR targeting the regions of difference (RD) genomic areas.
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 |
| TBMP | Mycobacteria Probe Ident | No, (Bill Only) | No |
| TBPB | Mycobacteria Probe Ident Broth | No, (Bill Only) | No |
| TBT | Mycobacteria Culture, Conc | No, (Bill Only) | No |
| TISSR | Tissue Processing | No, (Bill Only) | No |
Testing Algorithm
When this test is ordered, a reflex test may be performed and charged.
See Mycobacterial Culture Algorithm in Special Instructions.
Special Instructions
Method Name
Automated Detection of Positive Cultures Followed by Organism Identification with Rapid Methods, which may include Nucleic Acid Probes, DNA Sequencing, and MALDI-TOF Mass Spectrometry
Reporting Name
Mycobacterial CultureSpecimen Type
VariesForms: If not ordering electronically, complete, print, and send 1 of the following forms with the specimen:
Microbiology Test Request Form (T244) (http://www.mayomedicallaboratories.com/it-mmfiles/microbiology_test_request_form.pdf)
Neurology Test Request Form-General (T732) (http://www.mayomedicallaboratories.com/it-mmfiles/neurology-request-form.pdf)
General Test Request Form (T239) (http://www.mayomedicallaboratories.com/it-mmfiles/general-request-form.pdf)
Specimen source is required.
Submit only 1 of the following specimens:
Specimen Type: Body fluid
Container/Tube: Sterile container
Specimen Volume: 1 mL
Specimen Type: Bone marrow
Container/Tube: SPS/Isolator System or green top (lithium heparin)
Specimen Volume: Entire collection
Specimen Type: Gastric washing
Container/Tube: Sterile container
Specimen Volume: 10 mL
Collection Instructions: Neutralize specimen within 4 hours of collection with 100 mg of sodium carbonate per 5 to 10 mL of gastric wash.
Specimen Type: Respiratory
Sources: Bronchoalveolar lavage fluid, bronchial washing, sputum
Container/Tube: Sterile container
Specimen Volume: 3 mL
Collection Instructions: Collect 3 respiratory specimens for acid-fast smears and culture in patients with clinical and chest X-ray findings compatible with tuberculosis. These 3 specimens should be collected at 8- to 24-hour intervals (24 hours when possible) and should include at least 1 first-morning specimen.
Specimen Type: Stool
Container/Tube: Sterile container
Specimen Volume: 5-10 g
Specimen Type: Tissue
Container/Tube: Sterile container
Specimen Volume: 5-10 mm
Collection Instructions: Collect a fresh tissue specimen.
Specimen Type: Urine
Container/Tube: Sterile container
Specimen Volume: 2 mL
Collection Instructions: Collect a random urine specimen.
Specimen Type: Swab
Fresh tissue or body fluid is the preferred specimen type instead of a swab specimen.
Sources: Wound, tissue, or body fluid
Container/Tube: Culture transport swab (noncharcoal) culturette
Specimen Volume: Adequate specimen
Collection Instructions:
1. Before collecting specimen, wipe away any excessive amount of secretion and discharge, if appropriate.
2. Obtain secretions or fluid from source with sterile swab.
3. If smear and culture are requested or both a bacterial culture and mycobacterial culture are requested, collect a second swab to maximize test sensitivity.
Specimen Minimum Volume
Varies, 1.5 mL for body fluid, 3 mL for respiratory specimen, or a pea-sized piece of fresh tissue
Specimen Stability Information
| Specimen Type | Temperature | Time |
|---|---|---|
| Varies | Refrigerated (preferred) | 7 days |
| Ambient | 7 days |
Clinical Information
Mycobacteria species are responsible for significant morbidity and mortality in both immunocompromised and immunocompetent hosts. Mycobacterium tuberculosis is the causative agent of tuberculosis and it kills nearly 2 million people in the world each year. Nontuberculous mycobacteria such as Mycobacterium avium complex and Mycobacterium abscessus cause a variety of infections (eg, respiratory, skin, and soft tissue) and are important to detect and correctly identify in order to aid in clinical decision making. There are more than 170 recognized species of mycobacteria and identification of these organisms to the species level is often required to help guide appropriate therapy. Although there are direct detection methods available for Mycobacterium tuberculosis, growth of the organism on culture media is still necessary to allow for antimicrobial susceptibility testing. At this time, direct molecular detection methods are lacking for the nontuberculous mycobacteria and growth in culture is critical for identification and antimicrobial susceptibility testing.
Nocardia species and other aerobic actinomycetes (eg, Tsukamurella species, Gordonia species, Rhodococcus species) are also important causes of disease and isolation on culture media is important to facilitate identification and antimicrobial susceptibility testing. Nocardia and the other aerobic actinomycetes grow well on mycobacterial medium and, therefore, ordering a mycobacterial culture is recommended when infection with this group of organisms is suspected.
Reference Values
Negative
Cautions
Recovery of mycobacteria is dependent on the number of organisms present in the specimen, specimen collection methods, methods of processing, and patient factors such as the use of antimycobacteria therapy.
The use of BBL MGIT PANTA antibiotic mixture, although necessary for all nonsterile specimens, may have inhibitory effects on some mycobacteria.
Alert the laboratory if Mycobacterium genavense is suspected, as this species requires addition of mycobactin J to the culture medium for optimal growth and recovery.
Day(s) Performed
Monday through Sunday; Continuously
Report Available
62 days/Positive cultures reported as soon as detected, Negative 62 daysPerforming Laboratory
Mayo Medical Laboratories in Rochester
Test Classification
This test has been cleared or approved by the U.S. Food and Drug Administration and is used per manufacturer's instructions. Performance characteristics were verified by Mayo Clinic in a manner consistent with CLIA requirements.CPT Code Information
87116-Mycobacterial Culture
87015-Mycobacteria Culture, Concentration (if appropriate)
87118-Id MALDI-TOF Mass Spec AFB (if appropriate)
87150-Mycobacteria Probe Ident, Solid (if appropriate)
87150-Mycobacteria Probe Ident, Broth(if appropriate)
87150-Id, Mtb Speciation, PCR (if appropriate)
87153-Mycobacteria Identification by Sequencing (if appropriate)
87176-Tissue Processing (if appropriate)