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Test ID: CTB Mycobacteria and Nocardia Culture, Varies

Reporting Name

Mycobacterial Culture

Useful For

Detection and identification of Mycobacterium species, Nocardia species, and other aerobic actinomycetes

 

Identification is performed using the Hologic/GenProbe AccuProbes for selected Mycobacterium species, matrix assisted laser desorption ionization-time of flight (MALDI-TOF) mass spectrometry, or 500-base pair 16S rRNA gene sequencing

 

M tuberculosis complex species identification can be done upon request using rapid PCR targeting the regions of difference (RD) genomic areas

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 M avium complex and M 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 M 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.

Interpretation

A final negative report is issued after 42 days of incubation.

 

Positive cultures are reported as soon as detected.

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 Concentration, Mycobacteria 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.

 

The following algorithms are available in Special Instructions:

-Mycobacterium and Nocardia Culture Algorithm

-Meningitis/Encephalitis Panel Algorithm

Analytic Time

42 days/Positive cultures reported as soon as detected, Negative 42 days

Day(s) and Time(s) Performed

Monday through Sunday; Continuously

Clinical Reference

1. Pfyffer GE, Palicova F: Mycobacterium: general characteristics; laboratory detection, and staining procedures. In Manual of Clinical Microbiology. 10th edition. Vol 1, Edited by J Versalovic, KC Carroll, G Funke, et al: Washington, DC: ASM Press. 2011 pp 472-502

2. Tortoli E: Microbiological features and clinical relevance of new species of the genus Mycobacterium. Clin Microbiol Rev 2014;27(4):727-752 doi:10.1128/CMR.00035-14

3. Wilson WW: Nocardiosis: updates and clinical overview. Mayo Clin Proc 2012;87(7):403-407

Method Name

Automated Detection of Positive Cultures Followed by Organism Identification with Rapid Methods, which may include Nucleic Acid Probes, DNA Sequencing, and Matrix Assisted Laser Desorption/Ionization-Time of Flight (MALDI-TOF) Mass Spectrometry

Specimen Type

Varies


Necessary Information


1. Specimen source is required.

2. 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.



Specimen 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:

1. Collect 3 respiratory specimens for acid-fast smears and culture in patients with clinical and chest X-ray findings compatible with tuberculosis.

2. 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

Supplies: Stool Collection Kit, Random (T635)

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: 20-50 mL

Collection Instructions: Collect a random urine specimen.

 

Fresh tissue or body fluid is the preferred specimen type instead of a swab specimen.

Specimen Type: Swab

 

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

Body Fluid: 1.5 mL
Respiratory Specimen: 3 mL
Fresh Tissue: pea-sized piece

Specimen Stability Information

Specimen Type Temperature Time
Varies Refrigerated (preferred) 7 days
  Ambient  7 days

Reference Values

Negative

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)

LOINC Code Information

Test ID Test Order Name Order LOINC Value
CTB Mycobacterial Culture 50941-4

 

Result ID Test Result Name Result LOINC Value
CTB Mycobacterial Culture 50941-4

Forms

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

Mayo Clinic Laboratories | Neurology Catalog Additional Information:

mml-CNS-Infections, mml-Pediatric, mml-Spinal-Cord