Coexistence of Legionella pneumophila Bacteria and Free-Living Amoebae in Lakes Serving as a Cooling System of a Power Plant.

Elżbieta Zbikowska,Hanna Kletkiewicz,Maciej Walczak,Aleksandra Burkowska

doi:10.1007/s11270-014-2066-y

Elżbieta Zbikowska, Hanna Kletkiewicz + Show 2 more

Open Access

https://doi.org/10.1007/s11270-014-2066-y

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Journal: Water, air, and soil pollution	Publication Date: Jul 29, 2014
Citations: 48	License type: CC BY 4.0

Affiliation: Nicolaus Copernicus University

Abstract

The study was aimed at determining whether potentially pathogenic free-living amoebae (FLA) and Legionella pneumophila can be found in lakes serving as a natural cooling system of a power plant. Water samples were collected from five lakes forming the cooling system of the power plants Pątnów and Konin (Poland). The numbers of investigated organisms were determined with the use of a very sensitive molecular method—fluorescence in situ hybridization (FISH). The result of the present study shows that thermally altered aquatic environments provide perfect conditions for the growth of L. pneumophila and amoebae. The bacteria were identified in the biofilm throughout the entire research period and in the subsurface water layer in July and August. Hartmanella sp. and/or Naegleria fowleri were identified in the biofilm throughout the entire research period.

Highlights

Legionella spp. are Gram-negative non-encapsulated, non-endospore-forming bacilli, ranging in size from 0.3–0.9 μm×2–20 μm, with a single, polar flagellum
In Europe, L. pneumophila are responsible for 95 % of all reported cases of legionellosis, the remaining cases being caused by Legionella longbeachae (Whiley and Bentham 2011)
L. pneumophila are known to thrive in biofilms which form at the solid–liquid or at liquid–air interface

Summary

Introduction

Legionella spp. are Gram-negative non-encapsulated, non-endospore-forming bacilli, ranging in size from 0.3–0.9 μm×2–20 μm, with a single, polar flagellum. Human infection by Legionella pneumophila usually results from inhaling aerosol—droplets of water which contain bacterial cells (Pancer et al 2008; Declerck 2010). Legionella can multiply in temperatures ranging from 20 to 40 °C (Grabińska-Łoniewska 2010; Diederen 2008), the optimum temperature for their growth is 32–35 °C. They can survive in an aquatic environment in temperatures ranging from 0 to 68 °C and with pH ranging from 5.0 to 8.5 (Diederen 2008). L. pneumophila are known to thrive in biofilms which form at the solid–liquid or at liquid–air interface (floating biofilm, surface microlayer)

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