New water study shows superiority of IDEXX Legiolert™ test in identifying Legionnaires’ disease risk

IDEXX, the global leader in rapid microbiological testing for water, today announced the publication of a peer reviewed study1, “Evaluation of a most probable number method for the enumeration of Legionella pneumophila from potable and related water samples,” by leading water microbiology consultant, David Sartory, in Letters in Applied Microbiology. The paper concludes that the IDEXX Legiolert™/Quanti-Tray® test is superior to the standard method for quantifying Legionella pneumophila (L. pneumophila), the primary cause of Legionnaires’ disease.

The study compared performance of the IDEXX Legiolert/Quanti-Tray most probable number (MPN) method, with the ISO 11731-2 membrane filtration method for the enumeration of L. pneumophila from 100 ml potable water and related samples. Data from a multi-laboratory study analysed according to ISO 17994 showed that Legiolert/Quanti-Tray yielded on average higher counts of L. pneumophila. It also quantified the Legiolert medium as having a high specificity of 96·4%, and concluded that Legiolert/Quanti-Tray represented a significant improvement in the enumeration of L. pneumophila from drinking water-related samples.

The IDEXX Legiolert test is based on a bacterial enzyme detection technology that signals the presence of L. pneumophila through utilisation of a substrate present in the Legiolert reagent. L. pneumophila cells grow rapidly and reproduce using the rich supply of nutrients present in the Legiolert reagent. Actively growing strains of L. pneumophila use the added substrate to produce a brown colour indicator. Legiolert detects L. pneumophila at 1 organism in a 100 ml sample within 7 days.

  1. The full text can be accessed at http://onlinelibrary.wiley.com/doi/10.1111/lam.12719/full

Evaluation of a most probable number method for the enumeration of Legionella pneumophila from potable and related water samples

D.P. Sartory, K. Spies, B. Lange, S. Schneider, B. Langer

TM/® – Trademark or Registered Trademark of IDEXX Laboratories, Inc. or its affiliates in the United States and/or other countries.

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