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Nontuberculosis Mycobacteria DNA detection by PCR
Test Code38224
CPT Codes
87551<br /> This test is not available for New York patient testing<br /> Limited Access Code
Preferred Specimen
1 cc tissue (fresh or paraffin-embedded), and 1 mL fluids (non-blood)
Other Acceptable Specimens
E-swabs • Formalin-fixed paraffin-embedded tissues (FFPE, PET) • Non-blood body fluids collected in Vacutainer tubes without preservative • EDTA (lavender-top) tube
Instructions
Testing initiated upon receipt of specimen, Monday-Friday.
Tissue specimen must be submitted and maintained on Dry Ice.
Note: samples containing SPS will be tested for M. avium complex only. Tissue or fluid should be collected into a DNA free container labeled with at least two identifiers.
Tissue specimen must be submitted and maintained on Dry Ice.
Note: samples containing SPS will be tested for M. avium complex only. Tissue or fluid should be collected into a DNA free container labeled with at least two identifiers.
Transport Temperature
Frozen
Specimen Stability
Tissue and fluid
Room temperature: 6 hours
Refrigerated: 24 hours
Frozen: 60 days
For fixed tissue (PET blocks/unstained slides/scrolls)
Room temperature: Unrestricted
Reject Criteria (Eg, hemolysis? Lipemia? Thaw/Other?)
Tissues free-floating in formalin; Samples containing SPS, citrate, or heparin; Blood/Serum specimens; Samples collected on swabs (other than E-swabs)
Methodology
DNA extraction, Sequencing, Polymerase Chain Reaction, nucleic acid purification
Setup Schedule
Set up: Mon-Fri; Report available: 2-4 days (preliminary)
Reference Range
See Laboratory Report
Clinical Significance
While Mycobacterium tuberculosis complex members are the most commonly known human pathogens, Non-tuberculosis Mycobacteria (also known as environmental mycobacteria, atypical mycobacteria and mycobacteria other than tuberculosis (MOTT)) are also implicated in tuberculosis-like disease, localized lymphadenitis, gastrointestinal disease, and disseminated infections. Acid fast bacilli can be very difficult to grow due to their nutritional requirements. Some specimens may never reveal the presence of a pathogen because of low abundance and/or lack of viability. The use of PCR to detect Non-tuberculous Mycobacteria DNA extracted directly from clinical specimens facilitates the identification of these pathogens. For an accurate detection of the presence of Non-tuberculous Mycobacteria in clinical specimens, the UWMC Molecular Diagnosis Section utilizes a combination of several techniques. The detection of Mycobacterium avium complex, for example, relies on fluorescence resonance energy transfer (FRET) probes in a nested PCR protocol that targets the heat shock protein 65 gene (hsp65). Utilization of MAI complex specific fluorescent probes on a real-time PCR platform facilitates rapid and highly sensitive detection of MAI complex DNA in clinical specimens.
For other Non-tuberculous Mycobacteria (including rapidly growing mycobacteria (RGM)) as well as Mycobacterium leprae, detection and speciation involves a multi-locus PCR strategy. Identifications are performed by DNA sequencing, which provides direct, unambiguous data and can distinguish medically relevant phylogenetic lineages.
In many specimens acid fast bacilli can be seen microscopy of tissue sections but are very difficult to grow due to their fastidious nature, or are not viable as a result of antimicrobial therapy. Some specimens may never reveal the presence of a pathogen because of low abundance and/or lack of viability. The use of PCR to detect this DNA extracted directly from clinical specimens facilitates the identification of these pathogens.
For other Non-tuberculous Mycobacteria (including rapidly growing mycobacteria (RGM)) as well as Mycobacterium leprae, detection and speciation involves a multi-locus PCR strategy. Identifications are performed by DNA sequencing, which provides direct, unambiguous data and can distinguish medically relevant phylogenetic lineages.
In many specimens acid fast bacilli can be seen microscopy of tissue sections but are very difficult to grow due to their fastidious nature, or are not viable as a result of antimicrobial therapy. Some specimens may never reveal the presence of a pathogen because of low abundance and/or lack of viability. The use of PCR to detect this DNA extracted directly from clinical specimens facilitates the identification of these pathogens.
