Test Catalog

Test Id : CTB

Mycobacteria and Nocardia Culture, Varies

Useful For
Suggests clinical disorders or settings where the test may be helpful

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

 

Mycobacterium tuberculosis complex species identification can be done upon request using rapid polymerase chain-reaction (PCR) targeting the regions of difference (RD) genomic areas

Reflex Tests
Lists tests that may or may not be performed, at an additional charge, depending on the result and interpretation of the initial 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
LCTB Id, MTB complex Rapid PCR No, (Bill Only) No
MPCDB Probe, Each Additional (MPCDS) No, (Bill Only) No

Testing Algorithm
Delineates situations when tests are added to the initial order. This includes reflex and additional tests.

When this test is ordered, a reflex test may be performed at an additional charge.

 

The following algorithms are available:

-Mycobacterium and Nocardia Culture Algorithm

-Meningitis/Encephalitis Panel Algorithm

Special Instructions
Library of PDFs including pertinent information and forms related to the test

Method Name
A short description of the method used to perform the test

Automated Detection of Positive Cultures followed by Organism Identification/Nucleic Acid Probes/DNA Sequencing/Matrix Assisted Laser Desorption/Ionization Time-of-Flight (MALDI-TOF) Mass Spectrometry

NY State Available
Indicates the status of NY State approval and if the test is orderable for NY State clients.

Yes

Reporting Name
Lists a shorter or abbreviated version of the Published Name for a test

Mycobacterial Culture

Aliases
Lists additional common names for a test, as an aid in searching

Acid Fast Bacilli (AFB) Smear

Acid Fast Smear

Bacillus, acid-fast

Culture for TB (Tuberculosis)

Mycobacteria

Nocardia

Smear, Acid Fast Bacilli-AFB

5180-CTB

TB (Tuberculosis) Culture

Testing Algorithm
Delineates situations when tests are added to the initial order. This includes reflex and additional tests.

When this test is ordered, a reflex test may be performed at an additional charge.

 

The following algorithms are available:

-Mycobacterium and Nocardia Culture Algorithm

-Meningitis/Encephalitis Panel Algorithm

Specimen Type
Describes the specimen type validated for testing

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.

ORDER QUESTIONS AND ANSWERS

Question ID Description Answers
Q00M0014 Specimen Source

Specimen Required
Defines the optimal specimen required to perform the test and the preferred volume to complete testing

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, sterile container, or green top (lithium or sodium 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 to 10 g

 

Specimen Type: Tissue

Container/Tube: Sterile container

Specimen Volume: 5 to 10 mm

Collection Instructions: Collect a fresh tissue specimen.

 

Specimen Type: Urine

Container/Tube: Sterile container

Specimen Volume: 20 to 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, or Eswab

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.

Special Instructions
Library of PDFs including pertinent information and forms related to the test

Forms

If not ordering electronically, complete, print, and send 1 of the following forms with the specimen:

-General Request (T239)

-Microbiology Test Request (T244)

Specimen Minimum Volume
Defines the amount of sample necessary to provide a clinically relevant result as determined by the Testing Laboratory

See Specimen Required

Reject Due To
Identifies specimen types and conditions that may cause the specimen to be rejected

Blood or fixed tissue
Specimen in viral transport medium (including but not limited to M4, M5, BD viral transport media, thioglycolate broth)
Saliva
Swab sources of respiratory fluids (eg, sputum)
Swab sources of nasal, sinus, ear, mouth, throat, or scalp
Wood shaft or charcoal swab
Petri dish
Reject
 

Specimen Stability Information
Provides a description of the temperatures required to transport a specimen to the performing laboratory, alternate acceptable temperatures are also included

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

Useful For
Suggests clinical disorders or settings where the test may be helpful

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

 

Mycobacterium tuberculosis complex species identification can be done upon request using rapid polymerase chain-reaction (PCR) targeting the regions of difference (RD) genomic areas

Testing Algorithm
Delineates situations when tests are added to the initial order. This includes reflex and additional tests.

When this test is ordered, a reflex test may be performed at an additional charge.

 

The following algorithms are available:

-Mycobacterium and Nocardia Culture Algorithm

-Meningitis/Encephalitis Panel Algorithm

Clinical Information
Discusses physiology, pathophysiology, and general clinical aspects, as they relate to a laboratory test

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 approximately 200 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.

Reference Values
Describes reference intervals and additional information for interpretation of test results. May include intervals based on age and sex when appropriate. Intervals are Mayo-derived, unless otherwise designated. If an interpretive report is provided, the reference value field will state this.

Negative

Interpretation
Provides information to assist in interpretation of the test results

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

 

Positive cultures are reported as soon as detected.

Cautions
Discusses conditions that may cause diagnostic confusion, including improper specimen collection and handling, inappropriate test selection, and interfering substances

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 anti-mycobacteria therapy.

 

The use of BBL MGIT PANTA antibiotic mixture, although necessary for all nonsterile specimens, may have inhibitory effects on some mycobacteria.

Supportive Data

The Bactec 460 and Bactec MGIT 960 systems were compared. A total of 1,963 patient specimens were cultured, including 1,519 respiratory tract specimens that required decontamination with sodium hydroxide and 444 sterile specimens that did not need to be decontaminated. A total of 168 cultures grew acid-fast bacilli in 1 or both systems (8.5% positivity rate). The contamination rate for positive respiratory tract specimens was 3.8% in the Bactec 460 and 7.9% in the MGIT. Contamination of sterile specimens was 6.3% in the Bactec 460 and 10.1% in the MGIT. Combined rates were 4.3% for the Bactec 460 and 8.4% for the MGIT. The overall recovery rates for mycobacterial species, excluding Mycobacterium gordonae, were 82.8%, 79.1%, and 78.4% for the Bactec 460, MGIT 960, and solid media, respectively. Recovery rates for the Bactec 460 and MGIT 960 were considered to be equivalent.

Clinical Reference
Recommendations for in-depth reading of a clinical nature

1. Pfyffer GE, Palicova F: Mycobacterium: general characteristics; laboratory detection, and staining procedures. In: Versalovic J, Carroll KC, Funke G, eds. Manual of Clinical Microbiology. 10th ed. Vol 1. ASM Press; 2011:472-502

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

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

Special Instructions
Library of PDFs including pertinent information and forms related to the test

Method Description
Describes how the test is performed and provides a method-specific reference

The BACTEC MGIT 960 System is designed for the rapid detection of mycobacteria in clinical specimens. The system includes a liquid culture medium (BBL MGIT Mycobacteria Growth Indicator Tube), a growth supplement (BBL MGIT OADC Enrichment), and an antibiotic mixture (BBL MGIT PANTA). BBL MGIT OADC enrichment provides substances essential for the growth of mycobacteria. BBL MGIT PANTA contains a mixture of antimicrobial agents used to suppress the growth of contaminating bacteria.

 

A fluorescent compound is embedded in silicone on the bottom of each of the MGIT broth tubes. This compound is sensitive to the presence of oxygen dissolved in the broth. Initially, the large amount of dissolved oxygen quenches the emissions from the compound and little fluorescence can be detected. Later, actively respiring (growing) microorganisms consume the oxygen and allow the fluorescence to be detected.

 

The automated BACTEC MGIT 960 System monitors the tubes hourly for increasing fluorescence. Analysis of the fluorescence is used to determine if the tube is instrument-positive, ie, the test contains viable organisms. Culture tubes that remain negative for a minimum of 42 days and that show no visible signs of positivity are removed from the instrument as negatives.

 

In addition to the MGIT tube, Middlebrook 7H10/7H10S agar biplates are inoculated and incubated at 37 degrees C. Growth from positive MGIT tubes or agar plates is identified using a variety of techniques including Hologic/GenProbe AccuProbes, matrix assisted laser desorption ionization-time of flight (MALDI-TOF) mass spectrometry, or 16S rRNA gene sequencing. The Mycobacterium tuberculosis complex will be identified to the species level upon request, using rapid polymerase chain reaction.(Martin I, Pfyffer GE, Parrish N: Mycobacterium: General characteristics, laboratory detection and staining procedures. In: Carroll KC, Pfaller MA, Landry ML, et al, eds. Manual of Clinical Microbiology. 12th ed. Vol 1. ASM Press; 2019:558-575; Halse TA, Escuyer VE, Musser KA: Evaluation of a single tube multiplex real-time PCR for differentiation of the Mycobacterium tuberculosis complex in clinical specimens. J Clin Microbiol. 2011 Jul;49[7]:2562-2567. doi: 10.1128/JCM.00467-11)

PDF Report
Indicates whether the report includes an additional document with charts, images or other enriched information

No

Day(s) Performed
Outlines the days the test is performed. This field reflects the day that the sample must be in the testing laboratory to begin the testing process and includes any specimen preparation and processing time before the test is performed. Some tests are listed as continuously performed, which means that assays are performed multiple times during the day.

Monday through Sunday

Report Available
The interval of time (receipt of sample at Mayo Clinic Laboratories to results available) taking into account standard setup days and weekends. The first day is the time that it typically takes for a result to be available. The last day is the time it might take, accounting for any necessary repeated testing.

42 to 70 days

Specimen Retention Time
Outlines the length of time after testing that a specimen is kept in the laboratory before it is discarded

Raw specimen 3 to 7 days; Isolates from positive cultures kept 1 year.

Performing Laboratory Location
Indicates the location of the laboratory that performs the test

Rochester

Fees
Several factors determine the fee charged to perform a test. Contact your U.S. or International Regional Manager for information about establishing a fee schedule or to learn more about resources to optimize test selection.

  • Authorized users can sign in to Test Prices for detailed fee information.
  • Clients without access to Test Prices can contact Customer Service 24 hours a day, seven days a week.
  • Prospective clients should contact their Regional Manager. For assistance, contact Customer Service.

Test Classification
Provides information regarding the medical device classification for laboratory test kits and reagents. Tests may be classified as cleared or approved by the US Food and Drug Administration (FDA) and used per manufacturer instructions, or as products that do not undergo full FDA review and approval, and are then labeled as an Analyte Specific Reagent (ASR) product.

This test has been cleared, approved, or is exempt by the US 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
Provides guidance in determining the appropriate Current Procedural Terminology (CPT) code(s) information for each test or profile. The listed CPT codes reflect Mayo Clinic Laboratories interpretation of CPT coding requirements. It is the responsibility of each laboratory to determine correct CPT codes to use for billing.

CPT codes are provided by the performing laboratory.

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)

87150- Id, MTB complex Rapid PCR (if appropriate)

LOINC® Information
Provides guidance in determining the Logical Observation Identifiers Names and Codes (LOINC) values for the order and results codes of this test. LOINC values are provided by the performing laboratory.

Test Id Test Order Name Order LOINC Value
CTB Mycobacterial Culture 50941-4
Result Id Test Result Name Result LOINC Value
Applies only to results expressed in units of measure originally reported by the performing laboratory. These values do not apply to results that are converted to other units of measure.
CTB Mycobacterial Culture 50941-4

Test Setup Resources

Setup Files
Test setup information contains test file definition details to support order and result interfacing between Mayo Clinic Laboratories and your Laboratory Information System.

Excel | Pdf

Sample Reports
Normal and Abnormal sample reports are provided as references for report appearance.

Normal Reports | Abnormal Reports

SI Sample Reports
International System (SI) of Unit reports are provided for a limited number of tests. These reports are intended for international account use and are only available through MayoLINK accounts that have been defined to receive them.

SI Normal Reports | SI Abnormal Reports