20.500.12556/RUL-137091 Decreasing pasteurization treatment efficiency against amoeba-grown Legionella pneumophila—recognized public health risk factor Legionellae are gram-negative bacteria most commonly found in freshwater ecosystems and purpose-built water systems. In humans, the bacterium causes Legionnaires’ disease (LD) or a Pontiac fever. In this study, the different waters (drinking water, pool water, cooling towers) in which Legionella pneumophila has been isolated were studied to assess the possible risk of bacterial spreading in the population. The influence of physical and chemical parameters, and interactions with Acanthamoeba castellanii on L. pneumophila, were analyzed by Heterotrophic Plate Count, the Colony-forming units (CFU) methods, transmission electron microscopy (TEM), and Sequence-Based Typing (SBT) analysis. During the study period (2013–2019), a total of 1932 water samples were analyzed, with the average annual rate of Legionella-positive water samples of 8.9%, showing an increasing trend. The largest proportion of Legionella-positive samples was found in cooling towers and rehabilitation centers (33.9% and 33.3%, respectively). Among the isolates, L. pneumophila SGs 2–14 was the most commonly identified strain (76%). The survival of Legionella was enhanced in the samples with higher pH values, while higher electrical conductivity, nitrate, and free residual chlorine concentration significantly reduced the survival of Legionella. Our results show that growth in amoeba does not affect the allelic profile, phenotype, and morphology of the bacterium but environmental L. pneumophila becomes more resistant to pasteurization treatment. Acanthamoeba environment infection Legionella water Acanthamoeba okolje okužba legionela voda true false true Angleški jezik Slovenski jezik Članek v reviji 2022-06-01 10:13:19 2022-06-01 10:13:22 2022-09-15 04:14:39 0000-00-00 00:00:00 2022 0 0 19 str. iss. 3, art. 1099 Vol. 19 2022 0000-00-00 Zaloznikova Objavljeno NiDoloceno 0000-00-00 0000-00-00 0000-00-00 616.9 1660-4601 10.3390/ijerph19031099 94193155 ijerph-19-01099-v2.pdf ijerph-19-01099-v2.pdf 1 4B7EB7207E1FECC10DC3641B8DF74B31 56dbf5313a960e7b6f68a315199289278c8b607ee075a5879543ebb71075fb72 010f7866-e183-11ec-8aca-00155dcfd717 https://repozitorij.uni-lj.si/Dokument.php?lang=slv&id=156943 https://www.mdpi.com/1660-4601/19/3/1099 1 8f82b31d-e182-11ec-8aca-00155dcfd717 https://repozitorij.uni-lj.si/Dokument.php?lang=slv&id=156942 Medicinska fakulteta 0 0 0