Legiolert

For detection of Legionella pneumophila

 
       

  • Easy test setup significantly reduces laboratory work flow.
  • Detects Legionella pneumophila up to 7 days faster than traditional culture methods.
  • Reduces quality control (QC) steps.
  • Delivers definitive results in 7 days without additional confirmation steps.
  • Easy-to-use platform, similar to that of the Colilert Test.

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Overview

Easy
  • Any brown colour and/or turbidity indicates a positive for Legionella pneumophila.
  • Platform similar to that of the Colilert-18 Test: Ready-to-use reagents, no media preparation.
  • Use with Quanti-Tray/Legiolert for Most Probable Number (MPN) enumeration.

Rapid
  • Confirmed results in 7 days without additional steps.
  • Streamlined work flow with less than 2 minutes of hands-on time.
  • Quality control procedure can be done in 15 minutes.
Accurate
  • Specifically detects Legionella pneumophila, the primary cause of Legionnaires’ disease.1
  • Any brown colour and/or turbidity indicates a positive and minimises subjective result interpretation.

Science

How the Legiolert Test work

The Legiolert test detects Legionella pneumophila in water samples. This test is based on a bacterial enzyme detection technology that signals the presence of Legionella pneumophila through utilisation of a substrate present in the Legiolert reagent. Legionella pneumophila cells grow rapidly and reproduce using the rich supply of amino acids, vitamins, and other nutrients present in the Legiolert reagent. Actively growing strains of Legionella pneumophila use the added substrate to produce a brown colour indicator. The Legiolert test detects Legionella pneumophila at 1 organism in 100 mL within 7 days.

 

How to use

Learn how to use the Legiolert test


 
Potable
 
Nonpotable

Potable Samples

100 ml protocol


Step 1

Measure hardness of potable water sample and add corresponding Legiolert supplement.

Step 2

Add reagent to water sample and shake to dissolve.

Step 3

Pour sample into Quanti-Tray/Legiolert.

Step 4

Seal using the Quanti-Tray Sealer PLUS and incubate for 7 days.

Step 5

Read results: Any brown and/or turbid wells are positive for Legionella pneumophila.

Quanti-Tray/Legiolert provides Most Probable Number (MPN) results up to 2,272 per 100 mL sample.

Nonpotable Samples

The following instructions are for use with nonpotable water samples.


Step 1

Add reagent to sterile diluent.

Step 2

Treat nonpotable sample with Legiolert pretreatment.

Step 3

Add pretreated sample to reagent mixture.

Step 4

Pour sample into Quanti-Tray/Legiolert.

Step 5

Seal using the Quanti-Tray Sealer PLUS and incubate for 7 days.

Step 6

Read results: Any brown and/or turbid wells are positive for Legionella pneumophila.

Quanti-Tray/Legiolert provides Most Probable Number (MPN) results up to 2,272 per 100 mL sample.

Frequently asked questions

The Legiolert test is designed specifically for potable and nonpotable water samples.

The Legiolert test detects Legionella pneumophila in potable and nonpotable water samples. This test is based on a bacterial enzyme-detection technology that signals the presence of Legionella pneumophila through utilization of a substrate present in the Legiolert reagent. Legionella pneumophila cells grow rapidly and reproduce using the rich supply of amino acids, vitamins, and other nutrients present in the Legiolert reagent. Actively growing strains of Legionella pneumophila use the added substrate to produce a brown color indicator. The Legiolert test detects Legionella pneumophila at 1 organism in 100 mL within 7 days.

The Legiolert test is designed to specifically detect the primary causative agent of Legionnaires’ disease, which is Legionella pneumophila.

When using the protocol for potable water, the Legiolert test detects Legionella pneumophila at ≥1 organism/100mL. When using the protocol for nonpotable water, the Legiolert test detects Legionella pneumophila at ≥1 organism/mL (≥100 organism/100 mL).

There is no comparator for the Legiolert test. For comparison, use a negative control when interpreting results.

Potable water samples are incubated at 39°C (± 0.5°C) for 7 days. Nonpotable water samples are incubated at 37°C (± 0.5°C) for 7 days. Results can be read any time on the 7th day.

The Legiolert test requires a humidity level that ensures ≤10% sample volume loss in the Quanti-Tray/Legiolert wells. Appropriate humidity can typically be achieved by placing a pan of water on the bottom of the incubator so that it covers approximately 80% of the bottom interior surface.

Yes, if the results are positive. An inoculated Legiolert test sample that is positive before 7 days is a confirmed positive test for L. pneumophila. However, for an accurate quantitative determination of L. pneumophila in a sample, the results should be read at 7 days.

Yes, if the results are negative. If an inoculated Legiolert test sample is inadvertently incubated for more than 7 days, the lack of brown color and turbidity is a valid negative test result. However, brown color and/or turbidity that develops after 7 days is not a valid positive test result; the test should be repeated or verified.

No, the Legiolert Test can only be used with Quanti-Tray/Legiolert and it must be incubated paper-side down.

If you are unsure whether your water is potable or nonpotable, please contact IDEXX Technical Services at 0800 838 522 or email IDEXX-ANZ technical support at support@idexx.com.

The Legiolert reagent powder should be very light to light tan in color and free-flowing. If you have any concerns about the color or integrity of the powder, contact IDEXX Technical Services at 1-800-321-0207.

No. Quanti-Tray/Legiolert is specifically designed to be used with the Quanti-Tray Sealer PLUS.

Check with your local, state, and/or federal authorities for proper disposal of bacteriological biohazard materials at your facility.

The Legiolert test is not currently included in Standard Methods. IDEXX will pursue a listing for this test, as appropriate.

IDEXX plans to conduct regulatory trials in countries where Legionella pneumophila is regulated for potable and/or nonpotable water. Please refer to our approval map for updated approvals.

Varied sample temperatures were not validated during the Legiolert test product development. All samples tested were at room temperature before the testing began.

Yes, the Binder incubator sold by IDEXX Water is able to handle the higher humidity required by the Legiolert Test. Appropriate humidity can typically be achieved by placing a pan of water on the bottom of the incubator so that it covers approximately 80% of the bottom interior surface.

Yes, the Legiolert potable and nonpotable protocols have each been designed for optimal performance with different types of water. Testing a nonpotable sample with the potable protocol may provide false-positive results due to bacteria other than Legionella pneumophila. Testing a potable sample with the nonpotable protocol may result in reduced Legionella pneumophila detection due to the pretreatment step and smaller volume of sample tested.

Nonpotable water may contain high concentrations of bacteria other than Legionella pneumophila. The Legiolert test nonpotable protocol and the Legiolert Pretreatment have been optimized to prevent these non-target organisms from interfering with the test result. 

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Resources

IDEXX Water has reference materials and approval documents to support the many products in our water portfolio. Find the document(s) you need by selecting the link below.

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Product Information

Legiolert (20-test pack)
Catalog Number: WLGT-20

Legiolert (100-test pack)
Catalog Number: WLGT-100

Legiolert Supplement
Catalog Number: WLGT-SUP

Legiolert Pretreatment
Catalog Number: WLGT-PRE

Quanti-Tray/Legiolert (20 pack)
Catalog Number: WQTLGT-20

Quanti-Tray/Legiolert (100 pack)
Catalog Number: WQTLGT-100

IDEXX-QC Legionella pneumophila
Catalog Number: UN3373-WQC-P

Water Customer Support

Australia & New Zealand Head Office

IDEXX Laboratories Pty Ltd.
Unit 6, 38-46
South Street
Rydalmere, NSW 2116
AUSTRALIA

Tel: 1300 44 33 99
Fax (AU): 1800 634 409
Fax: (NZ): 0800 448 443

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Reference

1.  Brunette GW, ed. CDC Health Information for International Travel 2016: The Yellow Book. New York, NY: Oxford University Press; 2016.