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Identification of Acid Fast Bacilli

Test Code

AFB4

Description

This test is used for identification of acid fast bacilli (AFB) or partially acid fast organisms. Identification is performed to the greatest extent possible, which is usually to the species level but can be to the subspecies level for some organisms (e.g. Mycobacterium abscessus subsp. abscessus). See below for the different platforms, assays, and techniques that may be employed.

This test is ordered for pure isolates sent to the laboratory for identification (e.g. AFID). It does not need to be ordered separately for clinical samples that require organism identification since it is automatically included in those tests (e.g. AFB1 and AFB3).

Collection/Transport

Collect

Isolates of mycobacteria or partially acid fast organisms in solid media such as Middlebrook slant (7H10 or 7H11), Lowenstein-Jensen medium slant, or in broth (7H9, MGIT, MP BACT/Alert, VersaTrek).

Specimen volume: Lab must receive visible growth of isolate on solid media or an isolate in broth media (≥3 mL).

Unacceptable Conditions

Cultures received with incomplete identifiers.
Mixed cultures; Note that prior to rejection, attempts will be made to isolate the organisms. A reisolation charge will be applied in these cases.
Cultures containing mold.
Solid media with insufficient growth.
Liquid media with <2 mL.
Leaking specimens.

Storage Transport Temp

Transport or mail isolates at ambient temperature. For nontuberculous mycobacteria (NTM), follow IATA/ DOT category B and for M. tuberculosis complex isolates, follow IATA/DOT category A requirements for shipping biological materials.

Test Detail

Performed

Dependent on method used; see methodology section.

Methodology

Method	Usage	Internal order code applied	Days performed
PCR/MALDI-TOF mass spectrometry	Primary assay used on isolates for identification of M. tuberculosis complex, M. avium complex, M.kansasii, and subspeciation of M. abscessus.	MASID	Tu-Sat
Line probe assay	Typically used for speciation of M. tuberculosis complex, M. avium complex, and subspeciation of M. abscessus.	NTMID or MTB7	Tu-Sat
Sequencing	Typically used for speciation of uncommon mycobacteria, confirmation of M. intracellulare, or aerobic actinomycetes.	16S or RPOB	Once a week

Turnaround Time

Identification results are reported within 3 days to 2 weeks depending on which method is used.

Lab Department

Infectious Disease Laboratory, Mycobacteriology

Synonyms

Line probe assays, Hain, sequencing, identification, reverse hybridization assay

Related Tests

AFB1, AFB3, VETCX, ENVCX

NY State: Waiver/single use permit required for identification of AFB.

Result Interpretation

Interpretive Data

Organisms growing in pure cultures are identified to the species or subspecies level whenever possible or appropriate.

Fees/Coding

CPT Code

Below are different test methods used for identification of various types of AFB and partially acid fast organisms. Only the relevant test methods will be performed and charged for the organism recovered or sent to the lab.

Test	Method	CPT Code	Billing Code	When is this applied?
AFB identification	PCR/MALDI-TOF Mass spectrometry	87798 x 9	MASID (1st organism), MASI2 (2nd organism), MASI3 (3rd organism)	If an appropriate organism is recovered.
AFB identification	Line probe assay	87798 x 7	NTMID (1st organism), NTMD2 (2nd organism), NTMD3 (3rd organism)	If an appropriate organism is recovered.
MTB identification	Line probe assay	87556	MTB7T	If an appropriate organism is recovered.
rpoB identification	Sanger Sequencing	87153	RPOB	If an appropriate organism is recovered.
16S Identification	Sequencing	87153	16S	If the appropriate organism is recovered.
Reisolation	Reisolation	87116	TBRE	Reiolation for mixed or contaminated isolates received from facility.

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Identification of Acid Fast Bacilli

Test Code

Description

Collection/Transport

Collect

Unacceptable Conditions

Storage Transport Temp

Test Detail

Performed

Methodology

Turnaround Time

Lab Department

Synonyms

Related Tests

Result Interpretation

Interpretive Data

Fees/Coding

CPT Code

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Advanced Diagnostic Laboratories

Overview Search Tests

Identification of Acid Fast Bacilli

Test Code

Description

Collection/Transport

Collect

Unacceptable Conditions

Storage Transport Temp

Test Detail

Performed

Methodology

Turnaround Time

Lab Department

Synonyms

Related Tests

Result Interpretation

Interpretive Data

Fees/Coding

CPT Code

Recently Viewed Tests

Overview

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