IDEXX Summary. IDEXX Laboratories. Date: April Report Highlights:

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1 IDEXX Summary 17A Topic: Title: Author: Beta Trial Study report comparing Legiolert* versus the standard method in Germany, described in Trinkwasserverordnung 2001 in der Fassung v Anlage 5, Teil I f Comparison of the performance of the IDEXX Legiolert test against ISO /2 in recovering confirmed Legionella pneumophila from potable water samples IDEXX Laboratories Date: April 2016 Report Highlights: Legiolert was compared to ISO /2 1,2 at 4 independent laboratories that regularly test potable water samples in Germany Over 1,600 potable water samples were tested for L. pneumophila using both Legiolert and ISO /2 Data from the completed study showed: o Legiolert has comparable detection and quantification of L. pneumophila via all comparisons versus ISO /2 (Mean relative difference 3 vs. the cumulative best result = %) o Legiolert accurately recovered very low concentrations of L. pneumophila (as low as 1 CFU/100 ml of sample) o The false positivity rate of Legiolert was 3.5% (1134 confirmed L. pneumophila positive of 1175 analyzed) o Legiolert showed equivalent sensitivity as ISO /2 for detection and quantification of L. pneumophila in potable water samples 1. ISO 11731:1998. Water quality Detection and enumeration of Legionella. 2. ISO :2004. Water quality -- Detection and enumeration of Legionella -- Part 2: Direct membrane filtration method for waters with low bacterial counts. 3. ISO/DIS Water quality -- Water quality Criteria for establishing the equivalency of two microbiological methods. *Legiolert is a trademark or registered trademark of IDEXX Laboratories, Inc. or its affiliates in the United States and/or other countries.

2 Technical Note Comparison of the performance of the IDEXX Legiolert* test against ISO /2 for recovering confirmed Legionella pneumophila from potable water samples. Product Description Legiolert is a test that detects Legionella pneumophila in potable 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 when used with Quanti-Tray*/Legiolert*. Legiolert detects Legionella pneumophila at 1 organism in a 100 ml sample within 7 days. Scope This technical note contains data collected at four independent, certified laboratories that evaluated the performance of the Legiolert test prior to its launch in June The test matrix for this study was potable water samples collected at numerous locations as part of normal laboratory testing operations. The microorganisms present in these potable water samples were from wild populations that occurred naturally in the environment and did not result from supplemental spiking activities. Testing occurred over the course of 4 months and involved 1,604 separate potable water samples. This study compared the relative recovery of confirmed L. pneumophila by Legiolert after 7 days of incubation against ISO /2. *Legiolert and Quanti-Tray are trademarks or registered trademarks of IDEXX Laboratories, Inc. or its affiliates in the United States and/or other countries.

3 Procedure 1. Samples were collected from numerous locations as ml aliquots by 4 laboratory sites. 2. A 100 ml aliquot and a 1 ml aliquot of each sample were processed and analyzed following the procedures outlined in ISO /2 by using both direct plating (2 x 0.5 ml) and membrane filtration (MF, 100 ml) techniques. Selective plating was done on BCYE 1 (buffered charcoal yeast extract) containing GVPC 1 (glycine, vancomycin, polymyxin B, cycloheximide). Samples were incubated according to ISO /2. 3. A 100 ml aliquot of each sample was processed and analyzed following the procedures outlined in the Legiolert* beta trial protocol for 100 ml quantification using the Quanti- Tray*/Legiolert* device. Legiolert samples were incubated for 7 days at 39 ± 0.5ºC with 85% relative humidity. 4. Presumptive Legionella pneumophila positive samples from both methods were confirmed by assaying the following reactions: Growth on BCYE No growth on blood agar or comparable medium (BCYE minus cysteine, Tryptic Soy agar, or Nutrient agar) In some cases, isolates were further confirmed by reaction with L. pneumophila antibody latex agglutination. 5. In order to properly compare Legiolert to ISO /2 for the specific detection of Legionella pneumophila, presumptive positive samples were screened for the presence of Legionella other than L. pneumophila (e.g. L. bozemanae, L. anisa, L. micdadei) by examining isolates for fluorescence during exposure to 365 nm (or comparable) UV light. If further analysis was required to confirm the identity of potential nonpneumophila isolates, then reaction with L. pneumophila antibody latex agglutination was determined. Data resulting from the isolation non-pneumophila species of Legionella by ISO /2 was filtered from the analysis. *Legiolert and Quanti-Tray are trademarks or registered trademarks of IDEXX Laboratories, Inc. or its affiliates in the United States and/or other countries.

4 Results Of the original 1,604 potable water samples tested 326 contained confirmed L. pneumophila by at least one of the test methods. The mean relative difference 3 for recovery of L. pneumophila in 100 ml of water sample for Legiolert vs. ISO /2 is shown in the variability chart and table below. The jittered display allows visualization of relative difference calculation for each individual split sample. Legiolert 100 ml vs. MF 100 ml Legiolert 100 ml vs. Direct plating 1 ml Legiolert 100 ml vs. Trinkwasserverordnung best result Comparison Mean relative difference Lower 95% Upper 95% Observations Legiolert 100 ml vs. MF 100 ml 21.6% 3.4% 39.8% 285 Legiolert 100 ml vs. Direct plating 1 ml 63.7% 36.4% 90.9% 287 Legiolert 100 ml vs. ISO /2 best result (100 ml or 1 ml)* 1.6% -16.5% 19.6% 326 *Data derived from 1 ml direct plating was filtered for values 10 CFU to eliminate statistical anomalies derived from low plate counts. In such cases "best" values defaulted to the 100 ml MF plate, with the exception of when the 1 ml value was the only usable ISO /2 value.

5 Conclusions The data presented above clearly demonstrates the comparable detection and quantification of L. pneumophila by the Legiolert method compared to the standard method. Legiolert was able to accurately recover very low concentrations of L. pneumophila (as low as 1 cfu/100 ml of sample) without interference from the heterotrophic bacterial populations or chemical residues present in the potable water samples. Based on these data we conclude that, after 7 days of incubation, Legiolert performs as well as ISO /2 for the specific detection and quantification of L. pneumophila from potable water matrices. For technical questions, please contact: IDEXX Laboratories Technical Support 1 IDEXX Drive Westbrook, ME / About IDEXX Laboratories IDEXX Laboratories, Inc. is the global market leader in diagnostics and information technology solutions for animal health and water and milk quality. Headquartered in Maine, IDEXX employs over 6,000 people in more than 175 locations around the world. IDEXX is the world leader in microbiology testing technologies that ensure safe water. As the world's preferred provider of innovative drinking-water microbiology test kits, IDEXX is known for its breakthrough products. We provide easy, rapid, accurate and cost-effective water-testing solutions. Our sales, customer service and technical support teams serve customers in over 100 countries and our products have governmental approval in 40+ countries world-wide. References 1. ISO 11731:1998. Water quality - Detection and enumeration of Legionella. 2. ISO :2004. Water quality - Detection and enumeration of Legionella -- Part 2: Direct membrane filtration method for waters with low bacterial counts. 3. ISO/DIS Water quality - Criteria for establishing the equivalency of two microbiological methods. *Legiolert and Quanti-Tray are trademarks or registered trademarks of IDEXX Laboratories, Inc. or its affiliates in the United States and/or other countries.

6 Appendix Legiolert Trinkwasserverordnung Best Sample Confirmed MPN/100 ml 100 ml L. pneumophila CFU/100 ML 1 ml L. pneumophila CFU/100 ML (100 ml or 1 ml) L. pneumophila CFU/100 ML TNTC TNTC TNTC TNTC

7 TNTC TNTC TNTC TNTC

8 TNTC TNTC TNTC

9 TNTC TNTC TNTC

10

11 TNTC

12 TNTC TNTC TNTC TNTC TNTC

13 TNTC TNTC TNTC TNTC TNTC

14 TNTC

15 TNTC TNTC

16 TNTC TNTC TNTC TNTC TNTC

17 TNTC

18 TNTC TNTC TNTC TNTC TNTC TNTC