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Test ID: LEGRP Legionella species, Molecular Detection, PCR, Varies

Reporting Name

Legionella PCR

Useful For

Sensitive and rapid diagnosis of pneumonia caused by Legionella species

 

The assay is not recommended as a test of cure because bacteria nucleic acids may persist after successful treatment.

Clinical Information

Legionnaires disease was first recognized during a pneumonia outbreak at the Legionnaires convention in Philadelphia in 1976. Investigators with the CDC isolated a novel, gram-negative bacillus, later named Legionella pneumophila. It is now widely recognized that L pneumophila (and other members of the genus Legionella) cause Legionnaires disease.

Interpretation

A positive PCR result for the presence of a specific sequence found within the Legionella 5S rRNA gene indicates the presence of a Legionella species DNA, which may be due to Legionella infection or environmental/water Legionella DNA in the specimen.

 

A negative PCR result indicates the absence of detectable Legionella DNA in the specimen, but does not rule-out legionellosis as false-negative results may occur due to inhibition of PCR, sequence variability underlying the primers and probes, or the presence of Legionella species in quantities less than the limit of detection of the assay.

Analytic Time

3 days

Day(s) and Time(s) Performed

Monday through Sunday

Clinical Reference

1. Hayden RT, Uhl JR, Qian X, et al: Direct detection of Legionella species from bronchoalveolar lavage and open lung biopsy specimens: comparison of LightCycler PCR, in situ hybridization, direct fluorescence antigen detection, and culture. J Clin Microbiol 2001;39(7):2618-2626

2. Diederen BM, Kluytmans JA, Vandenbroucke-Grauls CM, Peeters MF: Utility of real-time PCR for diagnosis of Legionnaires' disease in routine clinical practice. J Clin Microbiol 2008;46(2):671-677

3. MacDonell MT, Colwell RR: The nucleotide sequence of the 5S rRNA from Legionella pneumophila. Nucleic Acids Res 1987;15(3):1335

4. Rucinski S, Murphy M, Kies K, et al: Eight Years of Clinical Legionella PCR Testing Illustrates a Seasonal Pattern. In The Journal of Infectious Diseases. Vol 218. Fourth Edition. Oxford University Press, 13 July 2018, pp 669-670 https://doi.org/10.1093/infdis/jiy201

Method Name

Rapid Polymerase Chain Reaction (PCR)

Specimen Type

Varies


Necessary Information


Specimen source is required.



Specimen Required


The high sensitivity of amplification by PCR requires the specimen to be processed in an environment in which contamination of the specimen by Legionella DNA is unlikely.

 

Specimen Type: Respiratory

Sources: Sputum, tracheal secretions/aspirates, transtracheal aspirate, bronchial washing/aspirate, bronchoalveolar lavage, lung fluid or pleural fluid

Container/Tube: Sterile container

Specimen Volume: 1 mL

 

Specimen Type: Fresh tissue or biopsy

Sources: Lung

Container/Tube: Sterile container

Specimen Volume: Entire collection


Specimen Minimum Volume

Fluid: 0.5 mL
Tissue: 5 mm(3)

Specimen Stability Information

Specimen Type Temperature Time Special Container
Varies Refrigerated (preferred) 7 days
  Frozen  7 days

Reference Values

Not applicable

Test Classification

This test was developed and its performance characteristics determined by Mayo Clinic in a manner consistent with CLIA requirements. This test has not been cleared or approved by the U.S. Food and Drug Administration.

CPT Code Information

87801

LOINC Code Information

Test ID Test Order Name Order LOINC Value
LEGRP Legionella PCR 5020-3

 

Result ID Test Result Name Result LOINC Value
SRC57 Specimen Source 31208-2
29515 Result 5020-3

Forms

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

Mayo Clinic Laboratories | Neurology Catalog Additional Information:

mml-CNS-Infections, mml-Pediatric