Title: Future of Legionella Monitoring: Strategies for Employing qPCR in a WMP.
Learner Objectives:
We will present data outlining the case that modern, rapid, microbiological technologies are currently available, and in many cases a better choice for assessing Legionella risk in building water systems.
Content/Topic Outline:
Presenter:
Michael Loewenstein
Presentation Description:
The cultural method (i.e., ISO 11731) is often purported to be the “Gold Standard” in Legionella testing. However, there are many known problems associated with this method – the most often noted being its extraordinarily long time to result which can be up to two weeks or more. This lengthy time to result puts the water system operator in a constantly reactive position, forcing the system to be used “at risk”, or even taken out of service for weeks or months at a time, whenever a significant Legionella recovery is observed.
We reported to AWT at the 2021 Annual Convention on results from Phase I of a study we conducted evaluating three distinct modern, PCR/qPCR-based technologies that employ “live/dead” differentiation chemistries. Phase I of this study compared these methods to one another as well as to the cultural method for lab-inoculated water samples. All three rapid methods showed equivalent or better qualitative detection efficiency in one day, compared to the 7-14 days required for the cultural method. We are currently in Phase II of the study which is comparing the most promising of the three rapid methods to the cultural method, utilizing samples gathered in various end-use field applications. Thus far, we are observing an alarming trend of detection of Legionella spp. via qPCR in the same samples for which detection was missed by culture – yielding (at time of publication) a hugely disturbing 63% false negative rate with the cultural method. This is consistent with data we collected in Phase I which showed that the cultural method had poor qualitative detection efficiency at low levels of Legionella contamination.
The good news is that these data demonstrate that there are now multiple, accurate, rapid Legionella testing alternatives to the cultural method, and technical improvements in recent years make them an excellent choice for routine Legionella monitoring. From a practical perspective, it is easy to grasp how a faster time to result would mean that water treaters could be more agile in their approach to managing the health of their water systems. However these new data suggest that rapid methods, in many cases, are the optimal choice for obtaining the most accurate assessment of Legionella risk in a facility’s water system.
The sensitivity, accuracy, and faster time to result of qPCR puts the water management team in a far more proactive position to efficiently detect Legionella, assess the situation, and take appropriate steps to mitigate the risk.
Presenter Bio:
Michael Loewenstein
Michael Loewenstein is the current Vice President of Scientific Consulting at Q Labs LLC in Cincinnati, OH. In this role, Mr. Loewenstein serves as the technical lead of much of Q Labs’ business including Water Treatment, and leads the Q Labs Technology Advancement Group. Mr. Loewenstein earned his B.S. in Microbiology, with a research focus in Molecular Genetics and Cellular Physiology from The Ohio State University. After graduation, Michael obtained a position in Corporate R&D Microbiology at Procter & Gamble where he focused on the development and validation of rapid/alternative microbial test methods, developed and launched preservative systems across a broad range of P&G products, and has developed particular expertise and passion for microbiological control of manufacturing. He has published several articles on this subject, including clean design, and monitoring programs of industrial and purified water systems. Michael currently serves in a volunteer capacity for several professional associations, including the AOAC Microbial Contaminants Expert Review Panel, and is a founding member of Manufacturing Hygiene Task Force of the Microbiology Committee for the Personal Care Products Council (PCPC). Michael is also looking forward to becoming more involved with the Cooling Water subcommittee of AWT!