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
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 |
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
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
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
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
Varies
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.
Question ID | Description | Answers |
---|---|---|
Q00M0014 | Specimen Source |
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.
If not ordering electronically, complete, print, and send 1 of the following forms with the specimen:
-General Request (T239)
-Microbiology Test Request (T244)
See Specimen Required
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 Type | Temperature | Time | Special Container |
---|---|---|---|
Varies | Refrigerated (preferred) | 7 days | |
Ambient | 7 days |
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
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
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.
Negative
A final negative report is issued after 42 days of incubation.
Positive cultures are reported as soon as detected.
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.
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.
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
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)
Monday through Sunday
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.
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)
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 |
Change Type | Effective Date |
---|---|
Test Status - Test Delay | 2021-09-29 |