Mobile Site ›
Print Page Email Page

Interpretive Handbook

‹ Back to index | Back to list | More information

Test 8204:
Legionella Culture

Clinical Information Discusses physiology, pathophysiology, and general clinical aspects, as they relate to a laboratory test

The Legionellaceae are ubiquitous in natural fresh water habitats, allowing them to colonize man-made water supplies, which may then serve as the source for human infections.

 

Legionella pneumophila and the related species, Legionella bozemanii, Legionella dumoffii, Legionella gormanii, Legionella micdadei, Legionella longbeachae, and Legionella jordanis have been isolated from patients with pneumonia (Legionnaires disease). The organism has been isolated from lung tissue, bronchoalveolar lavage, pleural fluid, transtracheal aspirates, and sputum. The signs, symptoms, and radiographic findings of Legionnaires disease are generally nonspecific.

Useful For Suggests clinical disorders or settings where the test may be helpful

Diagnosis of Legionnaires disease

 

Because examination by rapid PCR increases sensitivity and provides faster results, Mayo Medical Laboratories strongly recommends also ordering LEGRP/89564 Legionella species, Molecular Detection, PCR.

Interpretation Provides information to assist in interpretation of the test results

Identification of Legionella species from respiratory specimens provides a definitive diagnosis of Legionnaires disease.

 

Organisms isolated are identified as Legionella species as determined by 16S rRNA gene sequencing.

Cautions Discusses conditions that may cause diagnostic confusion, including improper specimen collection and handling, inappropriate test selection, and interfering substances

Although a semiselective media is utilized, recovery of Legionella in specimens heavily contaminated with indigenous flora (ie, sputum) may be difficult.

Reference Values Describes reference intervals and additional information for interpretation of test results. May include intervals based on age and sex when appropriate. Intervals are Mayo-derived, unless otherwise designated. If an interpretive report is provided, the reference value field will state this.

Negative

Positive specimens will be identified/speciated by 16S rRNA gene sequencing.

Clinical References Provides recommendations for further in-depth reading of a clinical nature

1. Edelstein PH: Legionella. In Manual of Clinical Microbiology. Tenth edition. Edited by J Versalovic. ASM Press, Washington, DC. 2007, pp. 770-785

2. CLSI Document MM18-A, Interpretive Criteria for Identification of Bacteria and Fungi by DNA Target Sequencing; Approved Guideline, Vol 28, Number 12, April 2008. CLSI, Wayne, PA