Legionella DNA detection by PCR

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General Information

Lab Name
Legionella DNA detection by PCR
Lab Code
LEGDNA
Epic Ordering
Legionella DNA detection by PCR
Description

Detection and identification Legionella pneumophila and other Legionella species.

Legionella species are slow growing fastidious gram-negative organisms that are ubiquitous in the environment. Most exposures which lead to human disease are waterborne, primarily due to inhalation of water droplets from contaminated potable water. Inhalation of water droplets containing Legionella can lead to severe lower respiratory infection (pneumonia) known as Legionnaire's disease. While Legionella is a cause of community acquired pneumonia, it can also be acquired from hospital water systems. Certain populations are at particularly high risk of developing this disease, including those with underlying chronic illness with a high mortality rate among immunocompromised patients. Early diagnosis is key to preventing Legionella-associated mortality.

Rapid urinary assays used to detect Legionella are specific only for L. pneumophila serotype 1, while culture methods require special media and Legionella species is often slow to grow. The LEGDNA (Legionella PCR) is a real-time PCR assay targeting 16S rRNA gene followed by sequence analysis which detects and identifies Legionella pneumophila and other Legionella spp.

Synonyms
16S PCR, Legionella identification, Legionella PCR, Legionella sequencing, legionellosis PCR, Legionnaires’ Disease, molecular Legionella, universal PCR
Components

Interpretation

Method

DNA extraction, nucleic acid purification, polymerase chain reaction (PCR), sequencing

Reference Range
See individual components
Guidelines

Ordering & Collection

Specimen Type
Tissue (Fresh frozen or paraffin-embedded), Fluid (see Acceptable Specimens for details)
Collection

Acceptable specimens are listed below. Please see Molecular Microbiology Specimen Submission for complete specimen collection and handling instructions.

Shipping/Handling

  • Fresh frozen tissue/fluid specimens should be collected into a DNA free container labeled with at least two identifiers and be submitted and maintained on dry ice.
  • Formalin Fixed Paraffin-embedded tissues (FFPE, PET) can be sent ambient or with ice packs during warmer summer months to prevent melting.

Acceptable Specimens

*Mycobacterium avium complex DNA Detection [MAVDNA] can be ordered on sputum

**Fungal PCR reflex NGS [FUNDNA] and Fungal DNA Detection by PCR (without reflex to NGS) [NRFDNA] may have interference due to some lots of eSwabs which have been found to contain Saccharomyces cerevisiae DNA, resulting in false positive detection. Clinical correlation and/or retesting with a different collection method is advised. The detection of S. cerevisiae from eSwab specimens can interfere with our ability to rule out other fungal DNA.

    Unacceptable Specimens

    • Blood, serum, plasma, stool/rectal swabs
    • No citrated or heparinized solutions
    • Tissues floating in formalin
    • Swab/fluid collected in tube containing agar

    Optimal Quantity:

    • Fresh Tissue: 0.3-1.0 cm^3
    • Fluid: 0.2-1 mL
    • Formalin Fixed Paraffin-embedded Tissue (FFPE/PET): blocks are preferred and will be sent back to client upon completion of testing
    • Scrolls/unstained slides: cross-sectional area >1cm^2 send 10 sections of 10µm thickness, if <1cm^2 send 20 sections if available

    Please note: We do not need a separate specimen aliquot for each test ordered. Only a single specimen aliquot or block of optimal quantity is necessary for performing multiple tests. If multiple aliquots or blocks of optimal quantity are sent, up to 2 will be pooled.

    Forms & Requisitions

    Molecular Microbiology Order Form

    Handling Instructions

    Please see Molecular Microbiology Specimen Submission for complete specimen collection and handling instructions.

    Quantity
    requested: See "Collection" for Optimal Quantity
    minimum: Specimens below optimal quantity are acceptable for testing, however, diagnostic yield is generally proportional to specimen size.

    Processing

    Processing

    UWMC/HMC: Store and send fresh tissue/fluid specimens refrigerated, if specimen storage and transport will exceed 8 hours, freeze at -20°C. Freeze all fresh tissue/fluid specimens at -20°C upon arrival in UW Molecular Microbiology.

    Performance

    LIS Dept Code
    Micro Molecular Diag (MMD)
    Performing Location(s)
    UW-MT Microbiology, Molecular Diagnostics
    206-520-4600

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    Shipping Address

    Attn: Molecular Microbiology
    UW CLSPS
    1601 Lind Ave SW Room 117
    Renton, WA 98057
    Phone: 206-520-4600
    Alternate phone: 206-598-6147

    Performing Lab Address

    Clinical Microbiology Lab, NW177
    University of Washington Medical Center
    1959 NE Pacific Street
    Seattle, WA 98195
    Phone: 206-598-5735
    Alternate phone: 206-598-6147

    Contact Information

    Please e-mail us with any questions or comments you may have. Your inquiry will be answered as soon as possible.

    email: molmicdx@uw.edu

    The Molecular Microbiology lab is open from Monday-Friday, 7am-4pm PDT.

    Billing inquiries and requests for faxed reports can be made to our Client Services Department at (206) 520-4600 or (800) 713-5198.

    For results or other inquiries, we can be reached by phone at the following numbers:

    • Phone: (206) 598-5735
    • Alternate phone: (206) 598-6147
    • FAX: (206) 520-4903

    For assistance during weekends, holidays and after hours, please contact Lab Medicine Resident at (206) 598-6190

    Frequency
    Fresh frozen tissues/fluids result in 2-3 business days after receipt of specimen. Formalin Fixed Paraffin-embedded tissues result in 3-4 business days after receipt of specimen.
    Available STAT?
    No

    Billing & Coding

    CPT codes
    87801
    LOINC
    49616-6
    Interfaced Order Code
    UOW4372