What are free-living amoebae (FLA) and why are they a concern in drinking water storage?

Free-living amoebae (FLA) are ubiquitous microorganisms found in environments like drinking water storage towers (DWST). Certain species, such as *Acanthamoeba sp.*, *Naegleria fowleri*, and *Balamuthia mandrillaris*, are pathogenic and can cause severe ocular or cerebral infections. They also serve as potential reservoirs for other harmful pathogens, making their control critical for public health.

Where are free-living amoebae most concentrated in drinking water storage towers?

Studies show a significantly higher density of free-living amoebae (FLA) in biofilms developed at the *upper water levels* of drinking water storage towers (DWST). A 1 log increase in amoebae density was observed at the surface compared to the middle and bottom levels, where concentrations were around 0.1–0.2 amoebae/cm². This makes upper-level biofilms a primary potential source of pathogenic microorganisms.

Do free-living amoebae levels in drinking water storage vary by season?

Yes, a distinct seasonal variation in amoebae distribution has been observed in drinking water samples. Maximal densities, around 30 amoebae L⁻¹, typically occur in summer, while minimal densities, approximately 16 amoebae L⁻¹, are found in winter. Potentially pathogenic genera like *Acanthamoeba* have also shown seasonal appearances, particularly in spring.

How can AMPAC USA systems help mitigate free-living amoebae in drinking water?

AMPAC USA designs and manufactures advanced reverse osmosis and water purification systems engineered for maximum contaminant removal, including free-living amoebae and other pathogens. Our industry-leading solutions ensure safe, clean water for commercial, industrial, and municipal applications. Leveraging over 30 years of direct field experience, AMPAC USA provides reliable systems to protect against waterborne threats and maintain water quality.

Biofilms Developed At Upper Water Levels In Drinking Water

Q: How do biofilms in drinking water towers contribute to amoebae contamination?

Biofilms provide a protective and nutrient-rich environment where free-living amoebae (FLA) can thrive and multiply, especially at the upper water levels of storage towers. The study found an increase in amoebae density, total cell density, and biofilm thickness over time at the surface. This indicates that biofilms act as a significant reservoir and potential source for pathogenic microorganisms, posing a continuous threat to water quality.

Keeping drinking water safe in storage is a big deal, especially when you’re dealing with amoeba biofilm. At AMPAC USA, we get that. We build solutions that give homes, businesses, and industrial sites clean, safe water. Our systems are designed to pull out the bad stuff and last a long time.

\\n\\nTaravaud, Alexandre; Ali, Myriam; Lafosse, Bernard; Nicolas, Valerie; Feliers, Cedric; Thibert, Sylvie; Levi, Yves; Loiseau, Philippe M.; Pomel, Sebastien\\n\\nSCIENCE OF THE TOTAL ENVIRONMENT, 633 157-166; 10.1016/j.scitotenv.2018.03.178AUG 15 2018\\n

Abstract

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Free-living amoebae, or FLA, are everywhere. You’ll find them in nature and in places we build, like drinking water storage towers (DWST). Some FLA, like Acanthamoeba sp., Naegleria fowleri, and Balamuthia mandrillaris, can cause serious eye or brain infections. They can also carry other pathogens. In this study, we looked at how many FLA there were and what types, across two different sampling periods.

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First, we checked three DWSTs over five seasons. We took samples from the surface, middle, and bottom of the water and biofilm. We used microscopy and PCR to analyze them. In the seasonal study, we found FLA in every DWST water sample, about 20 to 25 amoebae per liter. The number of amoebae changed with the seasons. We saw the most in summer, around 30 amoebae per liter, and the least in winter, about 16 amoebae per liter.

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We found FLA from the Acanthamoeba genus during two spring sampling campaigns. This suggests these potentially harmful amoebae might show up more in certain seasons. What’s interesting is we saw a 10-fold increase in amoebae density in biofilm samples taken from the surface of all DWSTs. The middle and bottom levels only had 0.1–0.2 amoebae per square centimeter.

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Our second study focused on kinetics. We analyzed biofilm samples every two weeks for three months from the surface and bottom of one DWST using phase contrast and confocal microscopy. We saw an increase in amoebae density, total cell density, and biofilm thickness over time at the DWST surface, but not at the bottom. This is the first study we know of that shows a much higher FLA density in biofilms at the upper water levels in DWSTs. This could mean these upper biofilms are a major source of harmful microorganisms.

\\nhttps://www.sciencedirect.com/science/article/pii/S0048969718309379?via%3Dihub\\n\\n

\\nThe post Enrichment of free-living amoebae in biofilms developed at upper water levels in drinking water storage towers: An inter- and intra-seasonal study appeared first on Facts About Water.\\n\\nSource: Water Feed