Test Catalog

Test Id : TB1LN

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Antimicrobial Susceptibility, Mycobacterium tuberculosis Complex, First Line, Varies

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Overview

Test Catalog

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

Rapid, qualitative susceptibility testing of Mycobacterium tuberculosis complex isolates growing in pure culture

 

Affirming the initial choice of chemotherapy for M tuberculosis infections

 

Confirming the emergence of drug resistance

 

Guiding the choice of alternate agents for therapy for M tuberculosis infections

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
STV2 Susceptibility, Mtb Cx, 2nd Line No, (Bill Only) No

Additional Tests
Lists tests that are always performed, at an additional charge, with the initial tests.

Test Id Reporting Name Available Separately Always Performed
STV1 Susceptibility, Mtb Complex, Broth No, (Bill Only) Yes

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

When this test is ordered, the additional test will always be performed and charged separately.

If resistance to a first line antimicrobial agent is detected reflex testing for confirmation of resistance and second line agents will be performed and charged.

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

Broth Dilution at Critical Drug Concentrations

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

Susceptibility, Mtb Complex, 1 Line

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

Acid-Fast Bacilli (AFB)

AFB (Acid-Fast Bacilli)

Antibiotic Susceptibility

Antimicrobial Susceptibility, Mycobacterium tuberculosis

Bacillus, Acid-Fast

MTB (Mycobacterium tuberculosis)

Mycobacteria Antimicrobial Susceptibility (MIC) (Minimum Inhibitory Concentration)

Mycobacterium tuberculosis (MTB)

Susceptibility Testing

Susceptibility, Mycobacterium tuberculosis

TB (Tuberculosis)

Tubercle Bacilli: Mycobacterium tuberculosis

Tuberculosis (TB)

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

When this test is ordered, the additional test will always be performed and charged separately.

If resistance to a first line antimicrobial agent is detected reflex testing for confirmation of resistance and second line agents will be performed and charged.

Specimen Type
Describes the specimen type validated for testing

Varies

Additional Testing Requirements

CTB / Mycobacteria and Nocardia Culture or CTBID / Culture Referred for Identification, Mycobacterium and Nocardia must also be ordered and will be charged separately unless identification of organism is provided.

Shipping Instructions

1. See Infectious Specimen Shipping Guidelines in Special Instructions.

2. Place specimen in a large infectious container (T146) and label as an etiologic agent/infectious substance.

Necessary Information

Specimen source and suspected organism identification are required.

ORDER QUESTIONS AND ANSWERS

Question ID Description Answers
Q00M0072 Specimen source (Required) and Organism Identification (Required unless concurrent identification test is ordered)

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

Specimen Type: Organism

Supplies: Infectious Container, Large (T146)

Container/Tube: Middlebrook 7H10 agar slant

Specimen Volume: Isolate

Collection Instructions: Organism must be in pure culture, actively growing.

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

Forms

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

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

Other Agar plate

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 Ambient (preferred)
Refrigerated

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

Rapid, qualitative susceptibility testing of Mycobacterium tuberculosis complex isolates growing in pure culture

 

Affirming the initial choice of chemotherapy for M tuberculosis infections

 

Confirming the emergence of drug resistance

 

Guiding the choice of alternate agents for therapy for M tuberculosis infections

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

When this test is ordered, the additional test will always be performed and charged separately.

If resistance to a first line antimicrobial agent is detected reflex testing for confirmation of resistance and second line agents will be performed and charged.

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

Primary treatment regimens for Mycobacterium tuberculosis complex often include isoniazid, rifampin, ethambutol, and pyrazinamide. Susceptibility testing of each M tuberculosis complex isolate against these first-line antimycobacterial agents is a key component of patient management.

 

In vitro susceptibility testing methods are available to assess the susceptibility of M tuberculosis complex isolates to selected antimycobacterial agents. The Clinical Laboratory Standards Institute (CLSI) provides consensus protocols for the methods, antimycobacterial agents, and critical concentrations of each agent to be tested in order to permit standardized interpretation of Mm tuberculosis complex susceptibility testing results. Current recommendations indicate that laboratories should use a rapid broth method in order to obtain M tuberculosis susceptibility data as quickly as possible to help guide patient management. Resistance, as determined by rapid testing, must be confirmed by another method or by another laboratory.

 

This test uses an FDA-cleared commercial system for rapid broth susceptibility testing of M tuberculosis complex and assesses resistance to antimycobacterial drugs at the critical concentrations.

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.

Results are reported as susceptible or resistant.

Interpretation
Provides information to assist in interpretation of the test results

Mycobacterium tuberculosis complex isolates are reported as susceptible or resistant to the aforementioned drugs at the critical concentrations.

 

Some experts believe that patients infected with strains exhibiting resistance to low levels of isoniazid (0.1 mcg/mL) but not exhibiting resistance to high levels (0.4 mcg/mL) may benefit from continuing therapy with this agent. A specialist in the treatment of tuberculosis should be consulted concerning the appropriate therapeutic regimen and dosages.

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

For resistant organisms, confirmatory testing is automatically performed by minimum inhibitory concentration for isoniazid, rifampin, and ethambutol.

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

1. Blumberg HM, Burman WJ, Chaisson RE, et al: American Thoracic Society/Centers for Disease Control and Prevention/Infectious Diseases Society of America: treatment of tuberculosis. Am J Respir Crit Care Med 2003;167(4):603-662

2. CLSI: Susceptibility Testing of Mycobacteria, Nocardiae, and Other Aerobic Actinomycetes; Approved Standard. CLSI document M24-A (ISBN 1-56238-550-3). CLSI, Wayne, PA, 2003

3. Inderlied CB, Pfyffer GE: Susceptibility test methods: Mycobacteria. In Manual of Clinical Microbiology. Eighth edition. Edited by PR Murray, EJ Baron, JH Jorgensen, et al. Washington, DC, ASM Press, 2003, pp 1149-1177

4. LaBombardi VJ: Comparison of the ESP and BACTEC Systems for testing susceptibilities of Mycobacterium tuberculosis complex isolates to pyrazinamide. J Clin Microbiol 2002;40:2238-2239

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

This test method is based on presence or absence of growth of Mycobacterium tuberculosis in broth cultures with the presence of critical concentrations of the antimycobacterial drugs isoniazid, rifampin, and ethambutol. One of 2 FDA-cleared platforms may be used.

 

The VersaTrek platform uses the presence or absence of a pressure increase inside broth vials containing M tuberculosis in the presence of critical concentrations of the antimycobacterial drugs isoniazid, rifampin, and ethambutol. Increasing pressure indicates the presence of actively growing M tuberculosis that is resistant to the critical concentration of drug contained in the broth. Low or undetectable pressure increases in the presence of critical drug concentrations suggests a lack of M tuberculosis growth and susceptibility to the drug at the tested concentration. Antimycobacterial drugs and concentrations tested are: isoniazid (0.1 mcg/mL and 0.4 mcg/mL), rifampin (1 mcg/mL), and ethambutol (5 mcg/mL and 8 mcg/mL).(Package insert: VersaTREK Mycobacteria Detection and Susceptibility Testing system, TREK Diagnostics, Cleveland, OH 2014)

 

The BACTEC MGIT 960 platform uses the production and measurement of fluorescence within a Mycobacterial Growth Indicator Tube (MGIT) in the presence of actively growing M tuberculosis complex isolates in the presence of critical concentrations of the antimycobacterial drugs isoniazid, rifampin, and ethambutol. Low or undetectable levels of fluorescence in the presence of critical drug concentrations suggests lack of M tuberculosis growth and susceptibility to the drug tested at the tested concentration. Increased fluorescence suggests active growth of M tuberculosis and resistance to the drug at the tested concentration. Antimycobacterial drugs and concentrations tested are: isoniazid (0.1 mcg/mL and 0.4 mcg/mL), rifampin (2 mcg/mL), and ethambutol (5 mcg/mL).(Package insert: BACTEC MGIT 960 SIRE Kit, BD Diagnostics, Sparks, MD 2016)

 

A separate test (TBPZA) is available for testing of the other first-line agent pyrazinamide.

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.

10 to 21 days

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

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.

87188 x 3-Antimicrobial Susceptibility, Mycobacterium tuberculosis Complex, Broth Method

87186-Susceptibility, Mtb Cx, 2nd Line (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
TB1LN Susceptibility, Mtb Complex, 1 Line 29579-0
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.
TB1LN Susceptibility, Mtb Complex, 1 Line 29579-0

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

Test Update Resources

Change Type Effective Date
Test Status - Test Resumed 2022-11-30
Test Status - Test Down 2022-01-20