Legionella, a common bacterium, is widely recognized as the cause of Legionnaires’ disease. It often colonizes engineered water systems, including premise plumbing, cooling towers, and is also frequently found in groundwater.
Researchers at Michigan State University conducted a study to detect and quantify pathogenic Legionella from sources including cooling towers, groundwater entering and exiting a reservoir (in untreated and treated storage tanks), influent pipes at two buildings, and hot and cold-water taps. Sampling was analyzed relative to factors such as location, temperature, chlorine levels, conductivity, pH, Heterotrophic Plate Count (HPC), and water age.
For the analysis, 10-liter water samples were concentrated using the InnovaPrep EasyElute™ Large Volume Concentration (LVC) Kits. This kit utilizes a high-surface-area PES ultrafilter and a unique elution buffer to perform Wet Foam Elution™, producing ~70 mL of concentrated sample. Droplet digital PCR was then used to detect Legionella, while organism viability was assessed with HPC and Idexx kits.
Several concerning levels of pathogenic Legionella species were identified, including Legionella pneumophila and L. bozmanii, the primary culprits in the rising cases of Legionnaires’ disease in the U.S. The study found that water age and system design were critical factors influencing Legionella prevalence.
The EasyElute LVC Kit proved effective for concentrating 10 Liter water samples from diverse sources, such as taps and cooling towers, underscoring the importance of robust monitoring and prevention strategies to ensure water quality and protect public health from Legionella-associated diseases. Since 2009, L. pneumophila has been on the United States Environmental Protection Agency Candidate Contaminant List; and much evidence that there should be federal regulations for monitoring and controlling this primary water-related bacterium.
Read the Publication:
Water Age Effects on the Occurrence and Concentration of Legionella Species in the Distribution System, Premise Plumbing, and the Cooling Towers Logan-Jackson, et al. Microorganisms 2022
