ALS Environmental are one of the first European laboratories to develop, validate and UKAS  accredit (ISO 17025:2005) the confirmation of Legionella bacteria by the Matrix Assisted Laser Disorption Ionisation Time of Flight (MALDI-ToF). The technique utilises the standard 3 plate culture method as outlined in ISO 11731 and allows confirmed results to be reported in Colony Forming Units per Litre (CFU/L) 2 days quicker than the standard culture agglutination confirmation approach.

This revolutionary and unique approach developed by ALS Environmental has been in development for a number of years. We have been in long term discussions' with UKAS and the Drinking Water Inspectorate (DWI) to ensure that our methods are accredited and conform to the appropriate regulations for water testing. Our method complies with UKAS, ACoP L8, HSG274 and HTM04-01 as standard with additional species information available free of charge.

The key features of the MALDI-ToF confirmation are:

• No more presumptive results
• Confirmed, Accredited Legionella results in 10 days (positive or negative)
• Results expressed as CFU/L
• Compliant with ACoP L8, ISO11731, HSG 274, HTM04-01
• No additional cost
• 2 day time saving on positive legionella results
• One of the most comprehensive Legionella Species database currently available in the world for this technique.

Sales & Marketing Manager Nick Barsby comments:

“The MALDI-ToF confirmation allows our customers to make incisive, well informed decisions about Legionella contamination. Our customers will no longer have to make difficult decisions based on presumptive Legionella results; the fact we are doing this for no additional cost emphasises our commitment to protecting public health”

The MALDI-ToF method of analysis significantly reduces the time to a confirmed result. We are able to completely remove the need for a presumptive stage which removes all of the associated risks. The MALDI-ToF also provides significant additional information on the species of Legionella or other bacteria and fungi; this information is not available using the standard agglutination confirmation techniques traditionally used to confirm bacteriological samples.

The technology works by examining the protein structure of the cells in the test sample. A mass spectra of the proteins is produced, which can be compared to a reference library in order to produce an identification. It has been used extensively in the clinical sector for over 5 years & ALS are one of the first environmental laboratories to successfully validate the technology and gain UKAS ISO 17025:2005 accreditation in the environmental sector.

The analysis of samples using MALDI-Mass Spectrometry is performed by ALS Environmental using Time-of-Flight (ToF). The mass determination of molecules within the vacuum chamber is achieved by a precise measurement of the time period between the acceleration of the ions in the source, and their impact on the detector.

On the instrument, we look at a specific mass range (2000 – 16000 Daltons), where proteins are expected. The protein structure of a cell is unique to a particular species, and so a protein ‘fingerprint’ of the sample can be produced. This ‘fingerprint’ can be compared to a reference library, in order to convert a protein mass spectra to an identification.

ALS Environmental have worked hard to build up a comprehensive database of Legionella and other bacteria and fungi to ensure that we supply our customers with the species level identification in over 98% of samples. The Legionella database developed and held by ALS is one of the most comprehensive in the world for this technique.

Pervinder Johal, Microbiology Operations Manager for ALS Environmental states:

“The completion of UKAS accreditation for the MALDI-ToF is a great statement of intent by ALS to the market to show that we are at the forefront of advancing technology. We are the first UK Environmental laboratory to have UKAS accreditation for this approach after years of hard work by our technical team behind the scenes.”

ALS Environmental are able to analyse up-to 20,000 Legionella samples a week using the MALDI-ToF technology at our Microbiology laboratory in Coventry, which is also UKAS ISO 17025:2005 and DWTS accredited for a wide range of Drinking Water parameters, including but not limited to:

• E-coli
• Listeria
• Staphylococcus
• Enterococci
• Coliforms
• Pseudomonas aeruginosa
• Salmonella
• Clostridium
• Pseudomonas Species

If you would like more information on the MALDI-ToF or if you would like to visit our Coventry laboratory to see the impact that the technology can have on your samples please contact your regional representative:

Click here to download the new ALS Legionella Brochure

If you would like a quotation for your Legionella samples then please request a quotation or contact your customer service advisor via e-mail or call us on 02476 42 12 13