Guía de referencia rápida Pseudalert* - Pàgines de la UAB

Rev 03252011
Technical Note
Comparison of the performance of the IDEXX Pseudalert* test against the ISO 16266
Method at recovering Pseudomonas aeruginosa from thermal pool and bottled water
samples
Scope
idexx.com
This technical note contains data collected at the Nestlé Waters Quality Assurance Center
in Vittel, France that evaluated the performance of the Pseudalert test prior to its launch in
September 2010. Samples of water used in the production of bottled water products and
from thermal (mineral) pools/spas served as the test matrix for this study. The
microorganisms present in these water samples were from wild populations that occurred
naturally in the environment and did not result from supplemental spiking activities.
Additional water samples were collected that were spiked with different bacterial species to
simulate a contamination event. Testing occurred over the course of two months. This
study compared the relative recovery of confirmed P. aeruginosa by Pseudalert after 24
hours of incubation against the ISO 16266 method.
Procedure
1. Water samples (>500 mL) were collected for testing. Thermal pool water samples
were analyzed the day of sampling and stored at room temperature. Bottled water
samples were obtained from facilities located at multiple global locations. They were
shipped and stored at room temperature prior to testing.
2. A 250 mL aliquot of each sample was processed and analyzed following the
procedures outlined in the ISO 16266 protocol.
3. A 250 mL aliquot of each sample was processed and analyzed following the
procedures outlined in the Pseudalert package insert for 250 mL presence/absence
testing using an IDEXX testing vessel. Pseudalert was incubated for 24 hours at
38±0.5ºC.
4. Presumptive P. aeruginosa positive samples from the ISO 16266 method were
subjected to the following confirmation procedures:
• No further confirmation was required if the colony was blue/green on CN agar
• Confirmation in acetamide broth was performed if the colony was not blue/green but
fluorescent on CN agar
• Confirmation in Oxidase, Kings B, and acetamide broth were performed if the colony
was not fluorescent but reddish/brown color on CN agar
5. Pseudalert positive samples were not confirmed.
6. The heterotrophic count of each water sample was measured following the ISO 6222
method.
* Pseudalert is a trademark or registered trademark of IDEXX Laboratories, Inc. or its affiliates in the United States and/or
other countries.