Thermophilic potentially pathogenic amoebae isolated from natural water bodies in Poland and their molecular characterization.

The free-living amoebae (FLA) may live in the environment and also within other organisms as parasites and then they are called amphizoic. They are potentially pathogenic for humans and animals and are found in water that is a source of infection. The aim of this study was molecular detection and identification of these FLA in natural water bodies in North-Western Poland to evaluate the risk of the pathogenic amoebae infections. We examined surface water samples collected from 50 sites and first, the tolerance thermic test was performed in order to select thermophilic, potentially pathogenic strains. For molecular identification of FLA, regions of 18S rDNA, 16S rDNA and intergenic spacers were amplified. Acanthamoeba T4 and T16 genotypes of 18S rDNA gene and 18S rDNA of H. vermiformis were detected. We identified two variants of Acanthamoeba T4 genotype, two variants of Acanthamoeba T16 genotype and one variant of H. vermiformis. Identification of the T16 genotype and H. vermiformis in water was for the first time in Poland. Additionally, we made attempts to adapt the RLB method for detection and differentiation of FLA species and strains. PCR seems to be more sensitive than RLB hybridization, though.