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Legionella Testing

What is Legionella?

Legionella is a genus of pathogenic gram-negative bacteria that includes the species L. pneumophila, causing legionellosis including a potentially fatal pneumonia-type illness called Legionnaires' disease and a mild flu-like illness called Pontiac fever


​Contracted by inhaling airborne water droplets containing viable Legionella bacteria.  People can get sick when they breathe in small droplets of water or accidently swallow water containing Legionella into the lungs.

Legionella may be visualized with by being cultured in cysteine-containing media such as buffered charcoal yeast extract agar. The bacteria is common in many environments, including soil and aquatic systems, with at least 50 species identified.


These bacteria, however, are not transmissible from person to person and most people exposed to the bacteria do not become ill.


Most outbreaks of Legionella are traced to poorly maintained cooling towers.

Legionella Bacteria
Legionella Testing London

Legionella Bacterial test - Specific Legionella testing including species & sub-identification

Where does Legionella come from?

Documented sources include cooling towers, swimming pools , domestic water systems and showers, ice-making machines, refrigerated cabinets, whirlpool spas, hot springs, fountains, dental equipment, soil, automobile windshield washer fluid, industrial coolant, and waste water treatment plants.

Industrial Smoke

How do we test for Legionella?

Stansted's laboratory procedures for the detection of Legionella in water concentrate the bacteria (by centrifugation and/or filtration through 0.2-μm filters) before inoculation onto a charcoal yeast extract agar containing selective agents to suppress other flora in the sample.


Heat and acid treatment are also used to reduce interference from other microbes in the sample.

Legionella testing
Legionella testing plate

After incubation for up to 10 days, suspect colonies are confirmed as Legionella if they grow on buffered charcoal yeast extract agar containing cysteine, but not on agar without cysteine added. 


Immunological techniques are then used to determine the species and/or serogroups of bacteria present in the sample.

Contact us today to help with your Legionella testing requirements
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